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Disentangling molecular alterations from water-content changes in the aging human brain using quantitative MRI
Posted in Alzheimer's Disease, Cell Biology, Signaling & Cell Circuits, Disease Biology, Small Molecules in Development of Therapeutic Drugs, Genome Biology, Medical Imaging Technology, Medical Imaging Technology, Image Processing/Computing, MRI, CT, Nuclear Medicine, Ultra Sound, MRI, Pharmacotherapy and Cell Activity, tagged Alzheimers Disease, Conditions and Diseases, health, research on August 1, 2019| Leave a Comment »
Reporter: Dror Nir, PhD
Authors' list: Shir Filo, Oshrat Shtangel, Noga Salamon, Adi Kol, Batsheva Weisinger, Sagiv Shifman & Aviv A. Mezer
Published in: Nature Communications volume 10, Article number: 3403 (2019)
It is an open question whether aging-related changes throughout the brain are driven by a common factor or result from several distinct molecular mechanisms. Quantitative magnetic resonance imaging (qMRI) provides biophysical parametric measurements allowing for non-invasive mapping of the aging human brain. However, qMRI measurements change in response to both molecular composition and water content. Here, we present a tissue relaxivity approach that disentangles these two tissue components and decodes molecular information from the MRI signal. Our approach enables us to reveal the molecular composition of lipid samples and predict lipidomics measurements of the brain. It produces unique molecular signatures across the brain, which are correlated with specific gene-expression profiles. We uncover region-specific molecular changes associated with brain aging. These changes are independent from other MRI aging markers. Our approach opens the door to a quantitative characterization of the biological sources for aging, that until now was possible only post-mortem.
The biology of the aging process is complex, and involves various physiological changes throughout cells and tissues1. One of the major changes is atrophy, which can be monitored by measuring macroscale brain volume reduction1,2. In some cases, atrophy can also be detected as localized microscale tissue loss reflected by increased water content3. This process is selective for specific brain regions and is thought to be correlated with cognitive decline in Alzheimer's disease2,4,5. In addition to atrophy, there are molecular changes associated with the aging of both the normal and pathological brain5,6. Specifically, lipidome changes are observed with age, and are associated with several neurological diseases7,8,9,10,11.
It is an open question as to whether there are general principles that govern the aging process, or whether each system, tissue, or cell deteriorates with age for different reasons12,13. On one hand, the common-cause hypothesis proposes that different biological aging-related changes are the result of a single underlying factor14,15. This implies that various biomarkers of aging will be highly correlated16. On the other hand, the mosaic theory of aging suggests that there are several distinct aging mechanisms that have a heterogenous effect throughout the brain12,13. According to this latter view, combining different measurements of brain tissue is crucial in order to fully describe the state of the aging brain. To test these two competing hypotheses in the context of volumetric and molecular aging-related changes, it is essential to measure different biological aspects of brain tissue. Unfortunately, the molecular correlates of aging are not readily accessible by current in vivo imaging methods.
The main technique used for non-invasive mapping of the aging process in the human brain is magnetic resonance imaging (MRI)2,17,18,19. Advances in the field have led to the development of quantitative MRI (qMRI). This technique provides biophysical parametric measurements that are useful in the investigation and diagnosis of normal and abnormal aging20,21,22,23,24,25,26,27. qMRI parameters have been shown to be sensitive to the microenvironment of brain tissue and are therefore named in vivo histology28,29,30. Nevertheless, an important challenge in applying qMRI measurements is increasing their biological interpretability. It is common to assume that qMRI parameters are sensitive to the myelin fraction20,23,30,31,32,33, yet any brain tissue including myelin is a mixture of multiple lipids and proteins. Moreover, since water protons serve as the source of the MRI signal, the sensitivity of qMRI parameters to different molecular microenvironments may be confounded by their sensitivity to the water content of the tissue34,35. We hypothesized that the changes observed with aging in MRI measurements20,23,30,31,32,33,36 such as R1, R2, mean diffusivity (MD), and magnetization transfer saturation (MTsat)37, could be due to a combination of an increase in water content at the expense of tissue loss, and molecular alterations in the tissue.
Here, we present a qMRI analysis that separately addresses the contribution of changes in molecular composition and water content to brain aging. Disentangling these two factors goes beyond the widely accepted "myelin hypothesis" by increasing the biological specificity of qMRI measurements to the molecular composition of the brain. For this purpose, we generalize the concept of relaxivity, which is defined as the dependency of MR relaxation parameters on the concentration of a contrast agent38. Instead of a contrast agent, our approach exploits the qMRI measurement of the local non-water fraction39 to assess the relaxivity of the brain tissue itself. This approach allows us to decode the molecular composition from the MRI signal. In samples of known composition, our approach provides unique signatures for different brain lipids. In the live human brain, it produces unique molecular signatures for different brain regions. Moreover, these MRI signatures agree with post-mortem measurements of the brain lipid and macromolecular composition, as well as with specific gene-expression profiles. To further validate the sensitivity of the relaxivity signatures to molecular composition, we perform direct comparison of MRI and lipidomics on post-mortem brains. We exploit our approach for multidimensional characterization of aging-related changes that are associated with alterations in the molecular composition of the brain. Finally, we evaluate the spatial pattern of these changes throughout the brain, in order to compare the common-cause and the mosaic theories of aging in vivo.
Different brain lipids have unique relaxivity signatures
The aging process in the brain is accompanied by changes in the chemophysical composition, as well as by regional alterations in water content. In order to examine the separate pattern of these changes, we developed a model system. This system was based on lipid samples comprising common brain lipids (phosphatidylcholine, sphingomyelin, phosphatidylserine, phosphatidylcholine-cholesterol, and phosphatidylinositol-phosphatidylcholine)7. Using the model system, we tested whether accounting for the effect of the water content on qMRI parameters provides sensitivity to fine molecular details such as the head groups that distinguish different membrane phospholipids. The non-water fraction of the lipid samples can be estimated by the qMRI measurement of lipid and macromolecular tissue volume (MTV, for full glossary of terms see Supplementary Table 1)39. By varying the concentration of the lipid samples, we could alter their MTV and then examine the effect of this manipulation on qMRI parameters. The parameters we estimated for the lipid samples were R1, R2, and MTsat. The potential ambiguity in the biological interpretation of qMRI parameters is demonstrated in Fig. 1a. On one hand, samples with similar lipid composition can present different R1 measurements (Fig. 1a, points 1 & 2). On the other hand, scanning samples with different lipid compositions may result in similar R1 measurements (Fig. 1a, points 2 & 3). This ambiguity stems from the confounding effect of the water content on the MR relaxation properties.
We evaluated the dependency of different qMRI parameters on the non-water fraction estimated by MTV. This analysis revealed strong linear dependencies (median R2 = 0.74, Fig. 1a, b and Supplementary Fig. 1a, b). These linear MTV dependencies change as a function of the lipid composition, reflecting the inherent relaxivity of the different lipids. We could therefore use the MTV derivatives of qMRI parameters (dqMRIdMTV, i.e., the slope of the linear relationship between each qMRI parameter and MTV) as a measure that is sensitive to molecular composition. By accounting for the Multidimensional Dependency on MTV ("MDM") of several qMRI parameters, a unique MRI relaxivity signature was revealed for each lipid (Fig. 1c). This implies that the water-related ambiguity demonstrated in the inset of Fig. 1a can be removed by measuring the MTV dependencies (Fig. 1c). Creating mixtures of several lipids provided supportive evidence for the generality of our framework. Figure 1d and Supplementary Fig. 1c show that the qMRI measurements of a mixture can be predicted by summing the MTV dependencies of pure lipids (for further details see Supplementary Note 1 and Supplementary Fig. 2). Furthermore, we used this biophysical model to predict the lipid composition of a mixture from its MDM measurements (Fig. 1e). This model provided a good estimation of the sphingomyelin (Spg) and phosphatidylserine (PS) content (R2 > 0.64) but failed to predict phosphatidylcholine (PtdCho) content (for further details see Supplementary Note 2). While lipids are considered to be a major source of the MRI signal in the brain 40,41,42,43,44,45, our approach can be applied to other compounds to reveal differences in the MRI signal between different proteins, sugars, and ions (Supplementary Fig. 1d). Hence, the relationships between qMRI parameters and MTV account for the effect of water on MRI measurements and could be of use in quantifying the biological and molecular contributions to the MRI signal of water protons.
The tissue relaxivity of the human brain is region-specific.
In order to target age-related changes in molecular composition, we applied the same approach for the human brain (Fig. 2a).
We found that the linear dependency of qMRI parameters on MTV is not limited to in vitro samples and a similar relationship was also evident in the human brain (Fig. 2b and Supplementary Figs. 3–5). Importantly, different brain regions displayed a distinct dependency on MTV. Therefore, the relaxivity of brain tissue is region-specific. Figure 2b provides an example for the regional linear trends of R1 and MTsat in a single subject. Remarkably, while the thalamus and the pallidum presented relatively similar R1 dependencies on MTV, their MTsat dependencies were different (p < 0.001, two-sample t-test). Compared to these two brain regions, frontal white-matter demonstrated different dependencies on MTV (p < 0.001, two-sample t-test). A better separation between brain regions can therefore be achieved by combining the MTV dependencies of several qMRI parameters (MTsat, MD, R1 and R2). The MTV derivatives of qMRI parameters are consistent across subjects (Fig. 2c and Supplementary Fig. 6), with good agreement between hemispheres (Supplementary Fig. 5). Moreover, they provide a novel pattern of differentiation between brain regions, which is not captured by conventional qMRI methods (Supplementary Fig. 7). In our lipid sample experiments, the MDM approach revealed unique relaxivity signatures of different lipids (Fig. 1c). Therefore, we attribute the observed diversity in the MTV derivatives of qMRI parameters across brain regions to the intrinsic heterogeneity in the chemophysical microenvironment of these regions. The multidimensional dependency of various qMRI parameters on MTV can be represented by the space of MTV derivatives to reveal a unique chemophysical MDM signature for different brain regions (Fig. 2d, see explanatory scheme of the MDM method in Supplementary Fig. 8). Fig. 2 figure2 The MDM method provides region-specific signatures in the in vivo human brain. a Representative MTV, MTsat, and R1 maps. b Calculating the MDM signatures. The dependency of R1 (left) and MTsat (right) on MTV in three brain regions of a single subject. For each region, MTV values were pooled into bins (dots are the median of each bin; shaded area is the median absolute deviation), and a linear fit was calculated (colored lines). The slopes of the linear fit represent the MTV derivatives of R1 and MTsat and vary across brain regions. c The reliability of the MDM method across subjects. Variation in the MTV derivatives of R1 (left) and MTsat (right) in young subjects (N = 23). Different colors represent 14 brain regions (see legend). Edges of each box represent the 25th, and 75th percentiles, median is in black, and whiskers extends to extreme data points. Different brain regions show distinct MTV derivatives. d Unique MDM signatures for different brain regions (in different colors). Each axis is the MTV derivative ("MDM measurements") of a different qMRI parameter (R1, MTsat, R2, and MD). The range of each axis is in the legend. Colored traces extend between the MDM measurements, shaded areas represent the variation across subjects (N = 23). An overlay of all MDM signatures is marked with dashed lines Full size image The in vivo MDM approach captures ex vivo molecular profiles To validate that the MDM signatures relate to the chemophysical composition of brain tissue, we compared them to a previous study that reported the phospholipid composition of the human brain7. First, we established the comparability between the in vivo MRI measurements and the reported post-mortem data. MTV measures the non-water fraction of the tissue, a quantity that is directly related to the total phospholipid content. Indeed, we found good agreement between the in vivo measurement of MTV and the total phospholipid content across brain regions (R2 = 0.95, Fig. 3a). Söderberg et al.7 identified a unique phospholipid composition for different brain regions along with diverse ratios of phospholipids to proteins and cholesterol. We compared this regional molecular variability to the regional variability in the MDM signatures. To capture the main axes of variation, we performed principal component analysis (PCA) on both the molecular composition of the different brain regions and on their MDM signatures. For each of these two analyses, the first principal component (PC) explained >45% of the variance. The regional projection on the first PC of ex vivo molecular composition was highly correlated (R2 = 0.84, Fig. 3b) with the regional projection on the first PC of in vivo MDM signatures. This confirms that brain regions with a similar molecular composition have similar MDM. Supplementary Fig. 9a provides the correlations of individual lipids with MDM. Importantly, neither MTV nor the first PC of standard qMRI parameters was as strongly correlated with the ex vivo molecular composition as the MDM (Supplementary Fig. 9b, c). We next used the MDM measurements as predictors for molecular properties of different brain regions. Following our content predictions for lipids samples (Fig. 1e), we constructed a weighted linear model for human data (for further details see Supplementary Note 3). To avoid over fitting, we reduced the number of fitted parameters by including only the MDM and the molecular features that accounted for most of the regional variability. The MTV derivatives of R1 and MTsat accounted for most of the variance in MDM. Thus, we used these parameters as inputs to the linear model, while adjusting their weights through cross validation. We tested the performance of this model in predicting the three molecular features that account for most of the variance in the ex vivo molecular composition. Remarkably, MRI-driven MDM measurements provided good predictions for the regional sphingomyelin composition (R2 = 0.56, p < 0.05 for the F-test, Fig. 3c) and the regional ratio of phospholipids to proteins (R2 = 0.56, p < 0.05 for the F-test, Fig. 3c).
Last, we compared the cortical MDM signatures to a gene co-expression network based on a widespread survey of gene expression in the human brain46. Nineteen modules were derived from the gene network, each comprised of a group of genes that co-varies in space. Six out of the nineteen gene modules were significantly correlated with the first PC of MDM. Interestingly, the first PC of MDM across the cortex was correlated most strongly with the two gene modules associated with membranes and synapses (Fig. 4, for further details see Supplementary Note 4 and Supplementary Figs. 10 and 11).
Post-mortem validation for the lipidomic sensitivity of MDM.
The aforementioned analyses demonstrate strong agreement between in vivo MDM measurements and ex vivo molecular composition based on a group-level comparison of two different datasets. Strikingly, we were able to replicate this result at the level of the single brain. To achieve this we performed MRI scans (R1, MTsat, R2, MD, and MTV mapping) followed by histology of two fresh post-mortem porcine brains (Fig. 5a, b). First, we validated the qMRI estimation of MTV using dehydration techniques. MTV values estimated using MRI were in agreement with the non-water fraction found histologically (adjusted R2 = 0.64, p < 0.001 for the F-test, Fig. 5c).
Next, we estimated the lipid composition of different brain regions. Thin-layer chromatography (TLC) was employed to quantify seven neutral and polar lipids (Supplementary Table 2 and Supplementary Fig. 12a). In accordance with the analysis in Fig. 3, we performed PCA to capture the main axes of variation in lipidomics, standard qMRI parameters, and MDM. Figure 5d shows that MTV did not correlate with the molecular variability across the brain, estimated by the 1st PC of lipidomics. Likewise, the molecular variability did not agree with the 1st PC of standard qMRI parameters (Fig. 5e).
Last, we applied the MDM approach to the post-mortem porcine brain. Similar to the human brain, different porcine brain regions have unique MDM signatures (Fig. 5f, g and Supplementary Fig. 12b). Remarkably, we found that agreement between lipid composition and MRI measurements emerges at the level of the MDM signatures. The molecular variability across brain regions significantly correlated with the regional variability in the MDM signatures (adjusted R2 = 0.3, p < 0.01 for the F-test, Fig. 5h). Excluding from the linear regression five outlier brain regions where the histological lipidomics results were 1.5 standard deviations away from the center yielded an even stronger correlation between MDM signatures and lipid composition (adjusted R2 = 0.55, p < 0.001 for the F-test, Supplementary Fig. 12c). This post-mortem analysis validates that the MDM approach allows us to capture molecular information using MRI at the level of the individual brain.
Disentangling water and molecular aging-related changes.
After establishing the sensitivity of the MDM signatures to the molecular composition of the brain, we used them to evaluate the chemophysical changes of the aging process. To assess aging-related changes across the brain, we scanned younger and older subjects (18 older adults aged 67 ± 6 years and 23 younger adults aged 27 ± 2 years). First, we identified significant molecular aging-related changes in the MDM signatures of different brain regions (Figs. 6 and 7, right column; Supplementary Fig. 13). Next, we tested whether the changes in MRI measurements, observed with aging, result from a combination of changes in the molecular composition of the tissue and its water content. We found that although it is common to attribute age-related changes in R1 and MTsat to myelin28,30,36, these qMRI parameters combine several physiological aging aspects. For example, using R1 and MTsat we identified significant aging-related changes in the parietal cortex, the thalamus, the parietal white-matter and the temporal white-matter (Figs. 6 and 7, left column). However, the MDM approach revealed that these changes have different biological sources (Figs. 6 and 7, middle columns; see Supplementary Figs. 14–17 for more brain regions).
In agreement with the mosaic hypothesis, we identified distinct aging patterns for different brain regions. For example, in the hippocampus we found a change in R2* values related to a higher iron concentration with age, along with significant reduction in the total hippocampal volume (Fig. 8a). This age-related shrinkage was not accompanied by lower MTV values, indicating conserved tissue density (Fig. 7b). In addition, there was no significant difference in the hippocampal MDM signature with age (Fig. 7b). Cortical gray-matter areas also exhibited similar trends of volume reduction without major loss in tissue density (Fig. 8a). Unlike the gray matter, in the white matter we did not find volume reduction or large iron accumulation with age (Fig. 8a). However, we did find microscale changes with age in tissue composition, as captured by the MDM signature (Figs. 6a and 7c, and Supplementary Fig. 13), accompanied by a significant density-related decline in MTV (Fig. 8a). These findings are consistent with previous histological studies49,50,51 (see Discussion), and provide the ability to monitor in vivo the different components of the aging mosaic.
Last, to test whether the different biological aging trajectories presented in Fig. 8a share a common cause, we evaluated the correlations between them (Fig. 8b). Importantly, the chemophysical trajectory did not correlate significantly with the iron or volume aging patterns. The spatial distribution of water-related changes was found to correlate with iron content alterations (R2 = 0.27) and chemophysical alterations (R2 = 0.25). However, the strongest correlation between aging-related changes was found in volume and iron content (R2 = 0.77). As shown previously, this correlation may be explained to some extent by a systematic bias in automated tissue classification23. Additional analysis revealed that the different dimensions of the MDM signature capture distinct patterns of aging-related changes (Supplementary Fig. 30). Hence, complementary information regarding the various chemophysical mechanisms underlying brain aging could be gained by combining them.
Normal brain aging involves multiple changes, at both the microscale and macroscale level. MRI is the main tool for in vivo evaluation of such age-related changes in the human brain. Here, we propose to improve the interpretation of MRI findings by accounting for the fundamental effect of the water content on the imaging parameters. This approach allows for non-invasive mapping of the molecular composition in the aging human brain.
Our work is part of a major paradigm shift in the field of MRI toward in vivo histology30,36,52. The MDM approach contributes to this important change by providing a hypothesis-driven biophysical framework that was rigorously developed. We demonstrated the power of our framework, starting from simple pure lipid phantoms to more complicated lipid mixtures, and from there, to the full complexity of the brain. In the brain, we show both in vivo and post-mortem validations for the molecular sensitivity of the MDM signatures. Early observations relate different qMRI parameters to changes in the fraction of myelin20,23,30,31,32,33,36. The current approach enriches this view and provides better sensitivity to the molecular composition and fraction of myelin and other cellular tissues.
We developed a unique phantom system of lipid samples to validate our method. While the phantom system is clearly far from the complexity of brain tissue, its simplicity allowed us to verify the specificity of our method to the chemophysical environment. Remarkably, our approach revealed unique signatures for different lipids, and is therefore sensitive even to relatively subtle details that distinguish one lipid from another. We chose to validate our approach using membrane lipids based on previous experiments40,41,42,43,44,45. Nevertheless, we do acknowledge the fact that brain tissue comprises many other compounds beside lipids, such as proteins, sugars, and ions. As we have shown, these other compounds also exhibit unique dependency on MTV. The effect of such compounds, along with other factors such as microstructure, and multi-compartment organization28 is probably captured when we apply the MDM approach to the in vivo human brain. Therefore, the phantoms were made to examine the MRI sensitivity for the chemophysical environment, and the human brain data was used to measure the true biological effects in a complex in vivo environment.
Our relaxivity approach captures the molecular signatures of the tissue, but is limited in its abilities to describe the full complexity of the chemophysical environment of the human brain. For example, R1 and R2, which are used to generate the MDM signatures, are also sensitive to the iron content23,48,52. However, we found that most of our findings cannot be attributed to alterations in iron content as measured with R2* (for more details see Supplementary Note 5). While there is great importance in further isolating different molecular components, we argue that accounting for the major effect of water on qMRI parameters (for R2 distributions see Supplementary Fig. 5) is a crucial step towards more specific qMRI interpretation.
We provide evidence from lipids samples and post-mortem data for the sensitivity of the MDM signatures to the molecular environment (Figs. 1e, 3b, and 5h). The variability of MDM values between human brain regions also correlated with specific gene-expression profiles (Fig. 4). While the comparison of in vivo human brain measurements to previously published ex vivo findings is based on two different datasets, these measurements are highly stable across normal subjects and the intersubject variabilities are much smaller than the regional variability. The agreement between the modalities provides strong evidence for the ability of our method to capture molecular information.
Remarkably, we were able to demonstrate the sensitivity of MDM signatures to lipid composition using direct comparison on post-mortem porcine brains. Even though there are many challenges in scanning post-mortem tissue, segmenting it, and comparing it to anatomically relevant histological results, we were able to replicate our in vivo findings. We provide histological validation for the MRI estimation of MTV. Moreover, we find that while standard qMRI parameters and MTV do not explain the lipidomic variability across the brain, the MDM signatures are in agreement with histological results. Lipids constitute the majority of the brain's dry weight and are known to be important for maintaining neural conduction and chemical balance53,54. The brain lipidome was shown to have a great deal of structural and functional diversity and was found to vary according to age, gender, brain region, and cell type55. Disruptions of the brain lipid metabolism have been linked to different disorders, including Alzheimer's disease, Parkinson's disease, depression, and anxiety7,8,11,54,55,56,57. Our results indicate that the MDM approach enhances the consistency between MRI-driven measurements and lipidomics, compared with standard qMRI parameters.
The simplicity of our model, which is based on a first-order approximation of qMRI dependencies, has great advantages in the modeling of complex environments. Importantly, we used lipids samples to show that the contributions of different mixture-components can be summed linearly (Fig. 1d). For contrast agents, the relaxivity is used to characterize the efficiency of different agents. Here, we treated the tissue itself, rather than a contrast material, as an agent to compute the relaxivity of the tissue. While relaxivity is usually calculated for R1 and R2, we extended this concept to other qMRI parameters. Our results showed that the tissue relaxivity changes as a function of the molecular composition. This suggests that the relaxivity of the tissue relates to the surface interaction between the water and the chemophysical environment. A theoretical formulation for the effect of the surface interaction on proton relaxation has been proposed before58,59. Specifically, a biophysical model for the linear relationship between R1 and R2 to the inverse of the water content (1/WC = 1/(1 – MTV)) was suggested by Fullerton et al.43. Interestingly, 1/WC varies almost linearly with MTV in the physiological range of MTV values. Applying our approach with 1/WC instead of MTV produces relatively similar results (Supplementary Fig. 28). However, using MTV as a measure of tissue relaxivity allowed us to generalize the linear model to multiple qMRI parameters, thus producing multidimensional MDM signatures.
We show that the MDM signatures allow for better understanding of the biological sources for the aging-related changes observe with MRI. Normal brain aging involves multiple changes, at both the microscale and macroscale levels. Measurements of macroscale brain volume have been widely used to characterize aging-associated atrophy. Our method of analysis can complement such findings and provide a deeper understanding of microscale processes co-occurring with atrophy. Moreover, it allows us to test whether these various microscale and macroscale processes are caused by a common factor or represent the aging mosaic. Notably, we discovered that different brain regions undergo different biological aging processes. Therefore, combining several measurements of brain tissue is crucial in order to fully describe the state of the aged brain. For example, the macroscale aging-related volume reduction in cortical gray areas was accompanied by conserved tissue density, as estimated by MTV, and region-specific chemophysical changes, as estimated by the MDM. In contrast, in white-matter areas both MDM and MTV changed with age. These microscale alterations were not accompanied by macroscale volume reduction. Our in vivo results were validated by previous histological studies, which reported that the cortex shrinks with age, while the neural density remains relatively constant49,50. In contrast, white matter was found to undergo significant loss of myelinated nerve fibers during aging51. In addition, we found that the shrinkage of the hippocampus with age is accompanied with conserved tissue density and chemophysical composition. This is in agreement with histological findings, which predict drastic changes in hippocampal tissue composition in neurological diseases such as Alzheimer, but not in normal aging49,50,60,61. In contrast, hippocampal macroscale volume reduction was observed in both normal and pathological aging2.
It should be noted that most of the human subjects recruited for this study were from the academic community. However, the different age groups were not matched for variables such as IQ and socioeconomic status. In addition, the sample size in our study was quite small. Therefore, the comparison we made between the two age groups may be affected by variables other than age. Our approach may benefit from validation based on larger quantitative MRI datasets27,62. Yet, we believe we have demonstrated the potential of our method to reveal molecular alterations in the brain. Moreover, the agreement of our findings with previous histological aging studies supports the association between the group differences we measured and brain aging. Our results suggest that the MDM approach may be very useful in differentiating the effects of normal aging from those of neurodegenerative diseases. There is also great potential for applications in other brain research fields besides aging. For example, our approach may be used to advance the study and diagnosis of brain cancer, in which the lipidomic environment undergoes considerable changes63,64,65.
To conclude, we have presented here a quantitative MRI approach that decodes the molecular composition of the aging brain. While common MRI measurements are primarily affected by the water content of the tissue, our method employed the tissue relaxivity to expose the sensitivity of MRI to the molecular microenvironment. We presented evidence from lipid samples, post-mortem porcine brains and in vivo human brains for the sensitivity of the tissue relaxivity to molecular composition. Results obtained by this method in vivo disentangled different biological processes occurring in the human brain during aging. We identified region-specific patterns of microscale aging-related changes that are associated with the molecular composition of the human brain. Moreover, we showed that, in agreement with the mosaic theory of aging, different biological age-related processes measured in vivo have unique spatial patterns throughout the brain. The ability to identify and localize different age-derived processes in vivo may further advance human brain research.
Phantom construction
The full protocol of lipids phantom preparation is described in Shtangel et al.66.
In short, we prepared liposomes from one of the following lipids: phosphatidylserine (PS), phosphatidylcholine (PtdCho), phosphatidylcholine-cholesterol (PtdCho-Chol), Phosphatidylinositol-phosphatidylcholine (PI-PtdCho), or sphingomyelin (Spg). These phantoms were designed to model biological membranes and were prepared from lipids by the hydration–dehydration dry film technique67. The lipids were dissolved over a hot plate and vortexed. Next, the solvent was removed to create a dry film by vacuum-rotational evaporation. The samples were then stirred on a hot plate at 65 °C for 2.5 h to allow the lipids to achieve their final conformation as liposomes. Liposomes were diluted with Dulbecco's phosphate buffered saline (PBS), without calcium and magnesium (Biological Industries), to maintain physiological conditions in terms of osmolarity, ion concentrations and pH. To change the MTV of the liposome samples we varied the PBS to lipid volume ratios66. Samples were then transferred to the phantom box for scanning in a 4 mL squared polystyrene cuvettes glued to a polystyrene box, which was then filled with ~1% SeaKem Agarose (Ornat Biochemical) and ~0.0005 M Gd (Gadotetrate Melumine, (Dotarem, Guerbet)) dissolved in double distilled water (ddw). The purpose of the agar with Gd (Agar-Gd) was to stabilize the cuvettes, and to create a smooth area in the space surrounding the cuvettes that minimalized air–cuvette interfaces. In some of our experiments we used lipid mixtures composed of several lipids. We prepared nine mixtures containing different combinations of two out of three lipids (PtdChol, Spg and PS) in varying volume ratios (1:1,1:2,2:1). For each mixture, we prepared samples in which the ratio between the different lipid components remained constant while the water-to-lipid volume fraction varied.
For the bovine serum albumin (BSA) phantoms, samples were prepared by dissolving lyophilized BSA powder (Sigma Aldrich) in PBS. To change the MTV of these phantoms, we changed the BSA concentration. For the BSA + Iron phantoms, BSA was additionally mixed with a fixed concentration of 50 µg/mL ferrous sulfate heptahydrate (FeSO4*7H2O). Samples were prepared in their designated concentrations at room temperature. Prepared samples were allowed to sit overnight at 4 ℃ to ensure BSA had fully dissolved, without the need for significant agitation, which is known to cause protein cross-linking. Samples were then transferred to the phantom box for scanning.
For Glucose and Sucrose phantoms, different concentrations of D-( + )-Sucrose (Bio-Lab) and D-( + )-Glucose (Sigma) were dissolved in PBS at 40 ℃. Samples were allowed to reach room temperature before the scan.
MRI acquisition for phantoms
Data was collected on a 3 T Siemens MAGNETOM Skyra scanner equipped with a 32-channel head receive-only coil at the ELSC neuroimaging unit at the Hebrew University.
For quantitative R1 & MTV mapping, three-dimensional (3D) Spoiled gradient (SPGR) echo images were acquired with different flip angles (α = 4°, 8°, 16°, and 30°). The TE/TR was 3.91/18 ms. The scan resolution was 1.1 × 1.1 × 0.9 mm. The same sequence was repeated with a higher resolution of 0.6 × 0.6 × 0.5 mm. The TE/TR was 4.45/18 ms. For calibration, we acquired an additional spin-echo inversion recovery (SEIR) scan. This scan was done on a single slice, with adiabatic inversion pulse and inversion times of TI = 2000, 1200, 800, 400, and 50. The TE/TR was 73/2540 ms. The scan resolution was 1.2 mm isotropic.
For quantitative T2 mapping, images were acquired with a multi spin-echo sequence with 15 equally spaced spin echoes between 10.5 ms and 157.5 ms. The TR was 4.94 s. The scan resolution was 1.2 mm isotropic. For quantitative MTsat mapping, images were acquired with the FLASH Siemens WIP 805 sequence. The TR was 23 ms for all samples except PI:PtdCho for which the TR was 72 ms. Six echoes were equally spaced between 1.93 ms to 14.58 ms. The on-resonance flip angle was 6°, the MT flip angle was 220°, and the RF offset was 700. We used 1.1-mm in-plane resolution with a slice thickness of 0.9 mm. For samples of sucrose and glucose, MTsat mapping was done similar to the human subjects, based on 3D Spoiled gradient (SPGR) echo image with an additional MT pulse. The flip angle was 10°, the TE/TR was 3.91/28 ms. The scan resolution was 1 mm isotropic.
Estimation of qMRI parameters for phantoms
MTV and R1 estimations for the lipids samples were computed based on a the mrQ39 (https://github.com/mezera/mrQ) and Vista Lab (https://github.com/vistalab/vistasoft/wiki) software. The mrQ software was modified to suit the phantom system66. The modification utilizes the fact that the Agar-Gd filling the box around the samples is homogeneous and can, therefore, be assumed to have a constant T1 value. We used this gold standard T1 value generated from the SEIR scan to correct for the excite bias in the spoiled gradient echo scans. While the data was acquired in two different resolutions (see "MRI acquisition"), in our analysis we use the median R1 and MTV of each lipid sample and these are invariant to the resolution of acquisition (Supplementary Fig. 1e). Thus, we were able to use scans with different resolutions without damaging our results. T2 maps were computed by implementing the echo‐modulation curve (EMC) algorithm68.
For quantitative MTsat mapping see the "MTsat estimation" section for human subjects.
MDM computation for phantoms
We computed the dependency of each qMRI parameter (R1, MTsat, and R2) on MTV in different lipids samples. This process was implemented in MATLAB (MathWorks, Natwick, MI, USA). To manipulate the MTV values, we scanned samples of the same lipid in varying concentrations. We computed the median MTV of each sample, along with the median of qMRI parameters. We used these data points to fit a linear model across all samples of the same lipid. The slope of this linear model represents the MTV derivative of the linear equation. We used this derivative estimate of three qMRI parameters (R1, R2, and MTsat) to compute the MDM signatures. The same procedure was used for the MDM computation of lipid mixtures.
MDM modeling of lipid mixtures
We tested the ability of MDM to predict the composition of lipid mixtures. For this analysis we used nine mixture phantoms (see "Phantom construction"), along with the three phantoms of the pure lipid constituents of the mixtures (PS, Spg, and Ptd-Cho).
In order to predict the qMRI parameters of a lipid mixture (Fig. 1d) we used Supplementary Eq. 1 (Supplementary Note 1). To further predict the composition of the mixtures (Fig. 1e) we used Supplementary Eq. 5 (Supplementary Note 2). We solved this equation using the QR factorization algorithm.
Human experiments complied with all relevant ethical regations. The Helsinki Ethics Committee of Hadassah Hospital, Jerusalem, Israel approved the experimental procedure. Written informed consent was obtained from each participant prior to the procedure.
Human subjects
Human measurements were performed on 23 young adults (aged 27 ± 2 years, 11 females), and 18 older adults (aged 67 ± 6 years, five females). Healthy volunteers were recruited from the community surrounding the Hebrew University of Jerusalem.
MRI acquisition for human subjects
For quantitative R1, R2*, & MTV mapping, 3D Spoiled gradient (SPGR) echo images were acquired with different flip angles (α = 4°, 10°, 20°, and 30°). Each image included five equally spaced echoes (TE = 3.34–14.02 ms) and the TR was 19 ms (except for six young subjects for which the scan included only one TE = 3.34 ms). The scan resolution was 1 mm isotropic. For calibration, we acquired additional spin-echo inversion recovery scan with an echo-planar imaging (EPI) read-out (SEIR-epi). This scan was done with a slab-inversion pulse and spatial-spectral fat suppression. For SEIR-epi, the TE/TR was 49/2920 ms. TI were 200, 400, 1,200, and 2400 ms. We used 2-mm in-plane resolution with a slice thickness of 3 mm. The EPI read-out was performed using 2 × acceleration.
For quantitative T2 mapping, multi‐SE images were acquired with ten equally spaced spin echoes between 12 ms and 120 ms. The TR was 4.21 s. The scan resolution was 2 mm isotropic. T2 scans of four subjects (one young, three old) were excluded from the analysis due to motion.
For quantitative MTsat mapping, 3D Spoiled gradient (SPGR) echo image were acquired with an additional MT pulse. The flip angle was 10°, the TE/TR was 3.34/27 ms. The scan resolution was 1 mm isotropic.
Whole-brain DTI measurements were performed using a diffusion-weighted spin-echo EPI sequence with isotropic 1.5-mm resolution. Diffusion weighting gradients were applied at 64 directions and the strength of the diffusion weighting was set to b = 2000 s/mm2 (TE/TR = 95.80/6000 ms, G = 45mT/m, δ = 32.25 ms, Δ = 52.02 ms). The data includes eight non-diffusion-weighted images (b = 0). In addition, we collected non-diffusion-weighted images with reversed phase-encode blips. For five subjects (four young, one old) we failed to acquire this correction data and they were excluded from the diffusion analysis.
Anatomical images were acquired with 3D magnetization prepared rapid gradient echo (MP-RAGE) scans for 24 of the subjects (14 from the younger subjects, 10 from the older subjects). The scan resolution was 1 mm isotropic, the TE/TR was 2.98/2300 ms. Magnetization Prepared 2 Rapid Acquisition Gradient Echoes (MP2RAGE) scans were acquired for the rest of the subjects. The scan resolution was 1 mm isotropic, the TE/TR was 2.98/5000 ms.
Estimation of qMRI parameters for human subjects
Whole-brain MTV and R1 maps, together with bias correction maps of B1 + and B1-, were computed using the mrQ software39,69 (https://github.com/mezera/mrQ). Voxels in which the B1 + inhomogeneities were extrapolated and not interpolated were removed from the MTV and R1 maps. While we did not correct our MTV estimates for R2*, we showed that employing such a correction does not significantly change our results (see Supplementary Note 6, Supplementary Figs. 20–27). MTV maps of four subjects had bias in the lower part of the brain and they were therefore excluded from the analysis presented in Fig. 3, which includes ROIs in the brainstem.
Whole-brain T2 maps were computed by implementing the echo‐modulation curve (EMC) algorithm68. To combine the MTV and T2 we co-registered the quantitative MTV map to the T2 map. We used the ANTS software package70 to calculate the transformation and to warp the MTV map and the segmentation. The registration was computed to match the T1 map to the T2 map. Next, we applied the calculated transformation to MTV map (since MTV and T1 are in the same imaging space) and resampled the MTV map to match the resolution of the T2 map. The same transformation was also applied to the segmentation. R2 maps were calculated as 1/T2.
Whole-brain MTsat maps were computed as described in Helms et al.37. The MTsat measurement was extracted from Eq. (1):
MTsat=𝑀0𝐵1𝛼𝑅1TR𝑆MT−(𝐵1𝛼)22−𝑅1TR
Where SMT is the signal of the SPGR scan with additional MT pulse, α is the flip angle and TR is the repetition time. Mo (the equilibrium magnetization parameter), B1 (the transmit inhomogeneity), and R1 estimations were computed from the non-MT weighted SPGR scans, during the pipeline described under "MTV & R1 estimation". Registration of the SMT image to the imaging space of the MTV map was done using a rigid-body alignment (R1, B1, and MO are all in the same space as MTV).
Diffusion analysis was done using the FDT toolbox in FSL71,72. Susceptibility and eddy current induced distortions were corrected using the reverse phase-encode data, with the eddy and topup commands73,74. MD maps were calculated using vistasoft (https://github.com/vistalab/vistasoft/wiki). We used a rigid-body alignment to register the corrected dMRI data to the imaging space of the MTV map (Flirt, FSL). In order to calculate the MD-MTV derivatives, we resampled the MTV map and the segmentation to match the dMRI resolution.
We used the SPGR scans with multiple echoes to estimate R2*. Fitting was done through the MPM toolbox75. As we had four SPGR scans with variable flip angles, we averaged the R2* maps acquired from each of these scans for increased SNR.
Human brain segmentation
Whole-brain segmentation was computed automatically using the FreeSurfer segmentation algorithm76. For subjects who had an MP-RAGE scan, we used it as a reference. For the other subjects the MP2RAGE scan was used as a reference. These anatomical images were registered to the MTV space prior to the segmentation process, using a rigid-body alignment. Sub-cortical gray-matter structures were segmented with FSL's FIRST tool77. To avoid partial volume effects, we removed the outer shell of each ROI and left only the core.
MDM computation in the human brain
We computed the dependency of each qMRI parameter (R1, MTsat, MD, and R2) on MTV in different brain areas. This process was implemented in MATLAB (MathWorks, Natwick, MI, USA). For each ROI, we extracted the MTV values from all voxels and pooled them into 36 bins spaced equally between 0.05 and 0.40. This was done so that the linear fit would not be heavily affected by the density of the voxels in different MTV values. We removed any bins in which the number of voxels was smaller than 4% of the total voxel count in the ROI. The median MTV of each bin was computed, along with the median of the qMRI parameter. We used these data points to fit the linear model across bins using Eq. (2):
qMRIparameters=𝑎∗MTV+𝑏
The slope of this linear model ("a") represents the MTV derivative of the linear equation. We used this derivative estimate to compute the MDM signatures.
For each subject, ROIs in which the total voxel count was smaller than a set threshold of 500 voxels for the MTsat and R1 maps, 150 voxels for the MD map, and 50 voxels for the R2 map were excluded.
Principal component analysis (PCA) in the human brain
To estimate the variability in the MDM signatures across the brain, we computed the first principal component (PC) of MDM. For each MDM dimension (MTV derivatives of R1, MTsat, MD, and R2), we evaluated the median of the different brain areas across the young subjects. As each MDM dimension has different units, we then computed the z-score of each dimension across the different brain area. Finally, we performed PCA. The variables in this analysis were the different MDM dimensions, and the observations were the different brain areas. From this analysis, we derived the first PC that accounts for most of the variability in MDM signatures across the brain. To estimate the median absolute deviations (MAD) across subjects of each MDM measurement in the PC basis, we applied the z-score transformation to the original MAD and then projected them onto the PC basis.
To compute the first PC of standard qMRI parameters we followed the same procedure, but used R1, MTsat, MD, and R2 instead of their MTV derivatives.
For the first PC of molecular composition, we followed the same procedure, but used the phospholipid composition and the ratio between phospholipids to proteins and cholesterol as variables. The data was taken from eight post-mortem human brains7. Brains were obtained from individuals between 54 and 57 years of age, which were autopsied within 24 h after death.
Linear model for prediction of human molecular composition
We used MDM measurements in order to predict the molecular composition of different brain areas (Fig. 3c). For this analysis we used Supplementary Eq. 5 in the Supplementary Note 2. We solved this equation using QR factorization algorithm (for more details see Supplementary Note 3).
Gene-expression dataset
For the gene-expression analysis we followed the work of Ben-David and Shifman46. Microarray data was acquired from the Allen Brain Atlas (http://human.brain-map.org/well_data_files) and included a total of 1340 microarray profiles from donors H0351.2001 and H0351.2002, encompassing the different regions of the human brain. The donors were 24 and 39 years old, respectively, at the time of their death, with no known psychopathologies. We used the statistical analysis described by Ben-David and Shifman46. They constructed a gene network using a weighted gene co-expression network analysis. The gene network included 19 modules of varying sizes, from 38 to 7385 genes. The module eigengenes were derived by taking the first PC of the expression values in each module. In addition, we used the gene ontology enrichment analysis described by Ben-David and Shifman to define the name of each module. The colors of the different modules in the Fig. 4 and Supplementary Fig. 10 are the same as in the original paper.
Next, we matched between the gene-expression data and the MRI measurements. This analysis was done on 35 cortical regions extracted from FreeSurfer cortical parcellation. We downloaded the T1-weighted images of the two donors provided by the Allen Brain Atlas (http://human.brain-map.org/mri_viewers/data) and used them as a reference for FreeSurfer segmentation. We then found the FreeSurfer label of each gene-expression sample using the sample's coordinates in brain space. We removed samples for which the FreeSurfer label and the label provided in the microarray dataset did not agree (there were 72 such samples out of 697 cortical samples). For each gene module, we averaged over the eigengenes of all samples from the same cortical area across the two donors.
Last, we compared the cortical eigengene of each module to the projection of cortical areas on the first PC of MDM. In addition, we compared the modules' eigengenes to the MTV values of the cortical areas and to the projection of cortical areas on the first PC of standard qMRI parameters (Supplementary Fig. 10). These 57 correlations were corrected for multiple comparisons using the FDR method.
Brain region's volume computation
To estimate the volume of different brain regions, we calculated the number of voxels in the FreeSurfer segmentation of each region (see "Brain segmentation").
R2* correction for MTV
To correct the MTV estimates for R2* we used Eq. (3):
MTV𝐶=1−(1−MTV)⋅exp(TE⋅R2∗)
Where MTVC is the corrected MTV.
The statistical significance of the differences between the age groups was computed using an independent-sample t-test (alpha = 0.05, both right and left tail) and was corrected for multiple comparisons using the false-discovery rate (FDR) method. For this analysis, MRI measurements of both hemispheres of bilateral brain regions were joined together. R2 measurements were adjusted for the number of data points. All statistical tests were two-sided.
Post-mortem tissue acquisition
Two post-mortem porcine brains were purchased from BIOTECH FARM.
Post-mortem MRI acquisition
Brains were scanned fresh (without fixation) in water within 6 h after death. Data was collected on a 3 T Siemens MAGNETOM Skyra scanner equipped with a 32-channel head receive-only coil at the ELSC neuroimaging unit at the Hebrew University.
For quantitative R1, R2*, & MTV mapping, 3D Spoiled gradient (SPGR) echo images were acquired with different flip angles (α = 4°, 10°, 20°, and 30°). Each image included five equally spaced echoes (TE = 4.01 – 16.51 ms) and the TR was 22 ms. The scan resolution was 0.8 mm isotropic. For calibration, we acquired additional spin-echo inversion recovery scan with an echo-planar imaging (EPI) read-out (SEIR-epi). This scan was done with a slab-inversion pulse and spatial-spectral fat suppression. For SEIR-epi, the TE/TR was 49/2920 ms. TI were 50, 200, 400, 1200 ms. The scan resolution was 2 mm isotropic. The EPI read-out was performed using 2 × acceleration.
For quantitative T2 mapping, multi‐SE images were acquired with ten equally spaced spin echoes between 12 and 120 ms. The TR was 4.21 s. The scan resolution was 2 mm isotropic.
For quantitative MTsat mapping, 3D Spoiled gradient (SPGR) echo image were acquired with an additional MT pulse. The flip angle was 10°, the TE/TR was 4.01/40 ms. The scan resolution was 0.8 mm isotropic.
Whole-brain DTI measurements were performed using a diffusion-weighted spin-echo EPI sequence with isotropic 1.5-mm resolution. Diffusion weighting gradients were applied at 64 directions and the strength of the diffusion weighting was set to b = 2000 s/mm2 (TE/TR = 95.80/6000 ms, G = 45mT/m, δ = 32.25 ms, Δ = 52.02 ms). The data includes eight non-diffusion-weighted images (b = 0).
For anatomical images, 3D magnetization prepared rapid gradient echo (MP-RAGE) scans were acquired. The scan resolution was 1 mm isotropic, the TE/TR was 2.98/2300 ms.
Following the MRI scans the brains were dissected. Total of 42 brain regions were identified. Four samples were excluded as we were not able to properly separate the WM from the GM. One sample was excluded as we could not properly identify its anatomical origin. Additional two samples were too small for TLC analysis.
The non-water fraction (MTV) was determined by desiccation, also known as the dry-wet method. A small fraction of each brain sample (~0.25 g) was weighed. In order to completely dehydrate the fresh tissues, they were left for several days in a vacuum dessicator over silica gel at 4 °C. The experiment ended when no further weight loss occurred. The MTV of each brain sample was calculated based on the difference between the wet (Wwet) and dry (Wdry) weights of the tissue (Eq. 4):
MTV=𝑊wet−𝑊dry𝑊wet
For lipid extraction and lipidomics analysis78, Brain samples were weighted and homogenized with saline in plastic tubes on ice at concentration of 1 mg/12.5 µL. Two-hundred fifty microliters from each homogenate were utilized for lipid extraction and analysis with thin-layer chromatography (TLC). The lipid species distribution was analyzed by TLC applying 150 µg aliquots. Samples were reconstituted in 10 µL of Folch mixture and spotted on Silica-G TLC plates. Standards for each fraction were purchased from Sigma Aldrich (Rehovot, Israel) and were spotted in separate TLC lanes, i.e., 50 µg of triacylglycerides (TG), cholesterol (Chol), cholesteryl esters (CE), free fatty acids (FFA), lysophospholipids (Lyso), sphingomyelin (Spg), phosphatidylcholine (PtdCho), phosphatidylinositol (PI), phosphatidylserine (PS), and phosphatidylethanolamine (PE). Plates were then placed in a 20 × 20 cm TLC chamber containing petroleum ether, ethyl ether, and acetic acid (80:20:1, v/v/v) for quantification of neutral lipids or chloroform, methanol, acetic acid, and water (65:25:4:2, v:v:v:v) for quantification of polar lipids and run for 45 min. TG, Chol, CE, FFA, phospholipids (PL), Lyso, Spg, PtdCho, PI, PS, and PE bands were visualized with Iodine, scanned and quantified by Optiquant after scanning (Epson V700). Lyso, CE, TG, and PI were excluded from further analysis as their quantification was noisy and demonstrated high variability across TLC plates. This analysis was conducted under the guidance of Prof. Alicia Leikin-Frenkel in the Bert Strassburger Lipid Center, Sheba, Tel Hashomer.
Estimation of qMRI parameters in the post-mortem brain
Similar to human subjects.
Brain segmentation of post-mortem brain
Brain segmentation was done manually. Five tissue samples were excluded as we could not identify their origin location in the MRI scans.
MDM computation in the post-mortem brain
We computed the dependency of each qMRI parameter (R1, MTsat, MD, and R2) on MTV in different brain areas similarly to the analysis of the human subjects.
Principal component analysis (PCA) in the post-mortem brain
To estimate the variability in the MDM signatures across the brain, we computed the first principal component (PC) of MDM. PCA analysis was performed with four variables corresponding to the MDM dimensions (MTV derivatives of R1, MTsat, MD, and R2), and 30 observations corresponding to the different brain regions. As each MDM dimension has different units, we first computed the z-score of each dimension across the different brain areas prior to the PCA. From this analysis we derived the first PC that accounts for most of the variability in MDM signatures across the brain.
To estimate the variability in the lipid composition across the brain, we computed the first principal component (PC) of lipidomics. PCA analysis was performed with seven variables corresponding to the different polar and neutral lipids (Chol, FFA, PL, Spg, PtdCho, PS, PE), and 30 observations corresponding to the different brain regions. From this analysis, we derived the first PC that accounts for most of the variability in lipid composition across the brain.
Reporting summary
Further information on research design is available in the Nature Research Reporting Summary linked to this article.
The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.
Code availability
A toolbox for computing MDM signatures is available at [https://github.com/MezerLab/MDM_toolbox].
The code generating the figures of in the paper is available at [https://github.com/MezerLab/MDM_Gen_Figs].
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Mezer, A., Rokem, A., Berman, S., Hastie, T. & Wandell, B. A. Evaluating quantitative proton-density-mapping methods. Hum. Brain Mapp. 37, 3623–3635 (2016).
Avants, B. B., Tustison, N. & Song, G. Advanced normalization tools (ANTS). Insight J. (2009). http://hdl.handle.net/10380/3113
Smith, S. M. et al. Advances in functional and structural MR image analysis and implementation as FSL. Neuroimage (2004). https://doi.org/10.1016/j.neuroimage.2004.07.051.
Behrens, T. E. J. et al. Characterization and propagation of uncertainty in diffusion-weighted MR imaging. Magn. Reson. Med. (2003). https://doi.org/10.1002/mrm.10609.
Andersson, J. L. R., Skare, S. & Ashburner, J. How to correct susceptibility distortions in spin-echo echo-planar images: application to diffusion tensor imaging. Neuroimage (2003). https://doi.org/10.1016/S1053-8119(03)00336-7.
Andersson, J. L. R. & Sotiropoulos, S. N. An integrated approach to correction for off-resonance effects and subject movement in diffusion MR imaging. Neuroimage (2016). https://doi.org/10.1016/j.neuroimage.2015.10.019.
Weiskopf, N. et al. Quantitative multi-parameter mapping of R1, PD*, MT, and R2* at 3T: a multi-center validation. Front. Neurosci. (2013). https://doi.org/10.3389/fnins.2013.00095.
Fischl, B. FreeSurfer. Neuroimage 62, 774–781 (2012).
Patenaude, B., Smith, S. M., Kennedy, D. N. & Jenkinson, M. A Bayesian model of shape and appearance for subcortical brain segmentation. Neuroimage (2011). https://doi.org/10.1016/j.neuroimage.2011.02.046.
Shomonov-Wagner, L., Raz, A. & Leikin-Frenkel, A. Alpha linolenic acid in maternal diet halts the lipid disarray due to saturated fatty acids in the liver of mice offspring at weaning. Lipids Health Dis. (2015). https://doi.org/10.1186/s12944-015-0012-7.
This work was supported by the ISF grant 0399306, awarded to A.A.M. We acknowledge Ady Zelman for the assistance in collecting the human MRI data. We thank Assaf Friedler for assigning research lab space and advising on the lipid sample experiments. We thank Inbal Goshen for assigning research lab space and advising on the protein and ion samples as well as the porcine brain experiments. We thank Magnus Soderberg for advising on histological data interpretation. We are grateful to Brian A. Wandell, Jason Yeatman, Hermona Soreq, Ami Citri, Mark Does, Yaniv Ziv, Ofer Yizhar, Shai Berman, Roey Schurr, Jonathan Bain, Asier Erramuzpe Aliaga, Menachem Gutman, and Esther Nachliel for their critical reading of the manuscript and very useful comments. We thank Prof. Alicia Leikin-Frenkel for her guidance with the TLC analysis. We thank Rona Shaharabani for guidance and support in the post-mortem experiments.
The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
Shir Filo, Oshrat Shtangel, Noga Salamon, Adi Kol, Batsheva Weisinger & Aviv A. Mezer
Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
Sagiv Shifman
S.F., O.S., and A.A.M. conceived of the presented idea. S.F. and A.A.M. wrote the manuscript and designed the figures. S.F. collected the human and non-human brain datasets and analyzed them. O.S. performed the phantom experiments and analyzed them. B.W. performed the phantom experiments for non-lipid compounds. N.S. performed the gene-expression analysis. S.S. assisted and instructed with the gene-expression analysis. A.K. performed the porcine brain dissection.
Correspondence to Aviv A. Mezer.
Ethics declarations & Competing interests
A.A.M, S.F., O.S. and the Hebrew University of Jerusalem have filed a patent application describing the technology used to measure MDM in this work. The other authors declare no competing interests.
The Empowered Patient
Posted in Digital HealthCare – biotech & internet joint ventures, Health Care System by Country, Healthcare Reform, Voices of Patients and Healthcare Providers, tagged health, health outcomes research, healthcare costs, Life Technologies, Patients on April 23, 2019| Leave a Comment »
Reporter: Gail S. Thornton
This report is entitled, "REDEFINING YOUR VALUE TO WIN THE EMPOWERED PATIENT. Six Steps for Life Sciences Firms to Stay Relevant in the New Healthcare Ecosystem," which was published by Strativity Group, LLC in 2019. Please find an excerpt below.
Patients have taken charge of their lives, and they are empowered by increasingly more sophisticated and accessible tools. They still require physicians, hospitals, insurance companies, and life sciences companies to support them, but the dialogue, expectations, and engagement are changing radically as patients approach their healthcare with confidence and knowledge rather than fear and submission.
Today's Patient Is the New Industry Authority Changing consumer expectations and behaviors have brought just about every industry to a tipping point, where consumers – not traditional experts, companies, or brands – have appointed themselves as the new authority. While the trend may have started in less expert-dependent industries like travel and banking, it's now also penetrating areas where consumers have historically had much less power and influence, including healthcare. The healthcare industry itself also emboldened patients to redefine their roles in response to rising healthcare costs, shrinking provider availability, and increased skepticism of the medical insurance and life sciences industries. Macro- and micro-trends have come together to create a perfect storm in healthcare, and that means life sciences firms need to seriously rethink their roles and value in the new patient centered landscape. To get a deeper understanding of the new environment, consider the following trends that are putting patients in the driver's seat: • Knowledge abundance The wealth of knowledge available online has made health information both broadly accessible and much more understandable. Hospitals, nonprofit associations, and bloggers transformed professional jargon and made it accessible to billions of consumers who are now turning to the web before they turn to traditional experts, such as physicians. In fact, a dotHealth Consumer Health Online 2017 Research Report that found 57% of consumers consult the internet for information before visiting a doctor and only 32% consult with their doctor first. iv • Evolution of peer groups Patients are establishing local and global support groups of peers in similar situations. They find this authentic support system trumps traditional knowledge sources such as physicians and pharmaceutical companies. Patients find more strength and support in those groups and amplify their roles in the overall ecosystem.
About Strativity Strativity is a strategy activation firm that partners with organizations that want to differentiate through consistently exceptional customer and employee experiences during a time of ever-evolving expectations and digital disruption. With a deep understanding of human motivation and a proven methodology, we engage the hearts, heads, and hands of executives, employees, and customers to deliver rapid and lasting change. Our philosophy, approach, and results have inspired industry leaders like BMW, FedEx, GSK, Honeywell, Johnson & Johnson, MasterCard, Mazda, Mercedes-Benz, The New York Times, Royal Caribbean Cruise Line, Teleflex, and Walmart to rely on Strativity to transform their organizations and enhance their performance.
https://pages.questexweb.com/rs/294-MQF-056/images/Strativity%20-%20Redefining%20Your%20Value%20to%20Win%20the%20Empowered%20Patient_revised_to%20Fierce_041519.pdf?aliId=eyJpIjoiWU1NdHFMbzJONkd1VldLMCIsInQiOiJaM2NUdUY3eVJKalhxdERtWElBMUlRPT0ifQ%253D%253D
Cancer at Work: An Interview With Barbara Wilson
Posted in Cancer - General, Cancer and Current Therapeutics, Cancer Screening, Patient's Voice: Personal Experience with Invasive Medical Procedures, Uncategorized, Voices of Patients and Healthcare Providers, tagged breast cancer, Cancer, cancer patient management, health, science on January 9, 2019| Leave a Comment »
This article appeared on the web site of Harley Street Concierge, one of the U.K.'s leading independent providers of clinical, practical and emotion support for cancer patients.
Whether you're supporting an employee through cancer at work. Or you're a cancer patient struggling to get the support you need. Either way, this Q and A with Barbara Wilson will help you out. Read on for a glimpse into Barbara's personal experience with breast cancer. Find out where companies are falling short of supporting employees. Discover what you need to do if you're feeling unsupported at work. And learn what's unacceptable for Barbara in a modern and civilised society.
In a 2013 interview about cancer at work, you expressed amazement at "the lack of understanding there is about cancer. And what the impact is on individuals". How would you say this has improved in the last 4 years? And what do you feel still needs to change?
There's greater awareness and understanding about cancer at work. More organisations are aware of the difficulties people face. But many organisations don't appreciate that recovery isn't straightforward or quick. They also tend to rely on generic return to work policies. And these are inappropriate when it comes to supporting people recovering from cancer. A lot still depends on how far the local line manager is prepared to support an employee. And whether they'll bend rules if need be about leave or sick pay.
You were diagnosed with breast cancer in 2005 and given the all clear in 2010. What did you learn about yourself through treatment and recovery?
I learned that I wasn't immortal or superhuman! And also that life is precious and so it's important to make the best of it. That doesn't actually mean counting off things on your bucket list. Or living each day as if it's your last. It's about appreciating what you have, family, friends and the sheer joy of being alive.
"Life is precious. It's about appreciating what you have, family, friends and the sheer joy of being alive."
It's a common misperception that people in remission want more family time or to travel the world. What reasons do your clients share with you for wanting to get back to work?
Yes. Before I had cancer, I remember asking a terminally ill employee why she still wanted to work. And she worked until a fortnight before her death. The simple answer is that it's about feeling normal. Using your brain. Being with friends and colleagues rather than on your own. And losing yourself in your work. There are also financial reasons. But typically – and I can say this based on my own experience – it's about being 'you' again rather than a cancer patient.
"I remember asking a terminally ill employee why she still wanted to work. And she worked until a fortnight before her death. Typically – and I can say this based on my own experience – it's about being 'you' again rather than a cancer patient."
You share tips for employers and HR professionals in this article for Macmillan. And you set out how to support a colleague during and after cancer treatment. What would you say to an employee who isn't feeling supported by their employer or colleagues in this way?
In my experience there are two main reasons why people often aren't supported.
1. Bosses and colleagues don't understand the full impact of cancer treatment. They won't understand what fatigue is or chemo brain or peripheral neuropathy. So they often expect people to get 'back to normal' work after 6 to 8 weeks. But recovery can take many months. This isn't helped by the person often looking fit and well.
2. People don't like talking about cancer at work. They feel awkward. And as a result often decide to say nothing. We advise people to be open from the outset. To understand their right to reasonable adjustments. And their responsibility to update their employer about their recovery and support needs. Employees recovering from cancer often have to take the lead. They have to guide their colleagues about the specific help they need. You can't expect others to do it for you. It sounds wrong but that's how it is.
"Bosses and colleagues often expect people to get 'back to normal' work after 6 to 8 weeks. But recovery can take many months. "
More than 100,000 people had to wait more than 2 weeks to see a cancer specialist in the UK last year. 25,153 had to wait more than 62 days to start treatment. What's your reaction to these statistics?
It's shocking. The worry for patients and their families during this period is totally debilitating. And on top of this it means that the cancer is growing unchecked. Where the cancer is aggressive, the delay may threaten lives. And it will certainly add to the overall costs of care. We really have to address this. It's just not acceptable in a modern and civilised society.
"The worry for patients and their families during this period is totally debilitating. We really have to address this."
Finally, can you tell us more about Working With Cancer?
Working With Cancer is a social enterprise and was established in June 2014. We support people affected by cancer to lead fulfilling and rewarding working lives. That means helping people to successfully return to work or remain in work. Or sometimes it's about helping people to find work – depending on their personal needs. We work with corporate, charities and other third sector organisations to support people throughout the UK.
We coach people diagnosed with cancer to re-establish their working lives. And we train employers to understand how to manage work and cancer. We'll advise teams about how to support a colleague affected by cancer. And we help carers juggle work whilst supporting their loved ones. Working With Cancer also helps organisations to update or improve their policies.
About Barbara Wilson
Barbara Wilson is a senior HR professional with almost 40 years' experience. Roles include Group Head of Strategic HR at Catlin Group Ltd. Deputy Head of HR at Schroders Investment Management. And Chief of Staff to the Group HR Director at Barclays. After a breast cancer diagnosis, Barbara launched Working With Cancer. It's a Social Enterprise providing coaching, training and consultancy to employers, employees, carers and health professionals.
For more information about Working With Cancer, click here to visit the website. Follow this link to connect with Barbara on Twitter. Email admin@workingwithcancer.co.uk. Or call 07508 232257 or 07919 147784.
https://harleystreetconcierge.com/cancer-at-work/
Other posts on the JP Morgan 2019 Healthcare Conference on this Open Access Journal include:
Top 10 Cancer Research Priorities
https://pharmaceuticalintelligence.com/2018/12/24/top-10-cancer-research-priorities/
Innovation + Technology = Good Patient Experience
https://pharmaceuticalintelligence.com/2018/12/24/innovation-technology-good-patient-experience/
Inspiring Book for ALL Cancer Survivors, ALL Cancer Patients and ALL Cardiac Patients – The VOICES of Patients, Hospitals CEOs, Health Care Providers, Caregivers and Families: Personal Experience with Critical Care and Invasive Medical Procedures
https://pharmaceuticalintelligence.com/2017/10/24/inspiring-book-for-all-cancer-survivors-all-cancer-patients-and-all-cardiac-patients-the-voices-of-patients-hospitals-ceos-health-care-providers-caregivers-and-families-personal-experience-with/
Funding Opportunities for Cancer Research
https://pharmaceuticalintelligence.com/2016/12/08/funding-opportunities-for-cancer-research/
The Incentive for "Imaging based cancer patient' management"
https://pharmaceuticalintelligence.com/2012/08/27/the-incentive-for-imaging-based-cancer-patient-management/
#JPM19 Conference: Dublin HealthBeacon Raises Funding
Posted in Digital HealthCare – biotech & internet joint ventures, Investment in Technological Breakthrough, Medical Devices R&D Investment, Medication Remote Compliance Monitoring, Uncategorized, Voices of Patients and Healthcare Providers, Wearable Tech + Digital Health, tagged Boston, Entrepreneur, Funding, health, Life Sciences, Medical Devices R&D Investment, Medical technology on January 9, 2019| Leave a Comment »
News announced during the 37th J.P. Morgan Healthcare Conference (#JPM19): Dublin medtech HealthBeacon raises $12m in a Series A round
HealthBeacon's Smart Sharps system helps patients adhere to their medication schedule. The company was founded by Jim Joyce and Kieran Daly in 2013, and opened offices in Boston in 2017. The digital platform, which last year received vital FDA clearance for the US market, not only ensures that patients keep up with their injectable treatments, but also allows them to dispose of medication in a safe way, and keeps carers up to date with the patients' progress.
Published January 8, 2019 by John Kennedy, Silicon Republic.
From left: Co-founders Kieran Daly and Jim Joyce. Image: HealthBeacon
With funding and FDA approval under its belt, this Dublin tech start-up has plans to help patients stick to their medication schedule.
Dublin and Boston digital health company HealthBeacon has raised $12m in a Series A investment round that brings total investment in the company to almost $15m.
The round was organised by HealthBeacon and Cantor Fitzgerald, led by Oyster Capital and Elkstone Partners, and the investment syndicate included Quorndon Capital and Cantor Fitzgerald's private client group. Earlier investors in HealthBeacon include Enterprise Ireland, BVP and a range of angel investors.
'I know with confidence as to whether my patients are adhering to their treatment strategy'
– DOUG VEALE
"Cantor has a major focus on life sciences and on digital health, and we have every confidence that CEO and co-founder Jim Joyce has created a true sector leader in HealthBeacon," said Liam Kiely, director of Cantor Fitzgerald.
The announcement was made in San Francisco at the JPMorgan Chase Biotech Showcase. The funding comes on the back of rapid global expansion of the FDA-cleared HealthBeacon Smart Sharps technology.
Dublin-based HealthBeacon's Smart Sharps system helps patients adhere to their medication schedule. The company was founded by Jim Joyce and Kieran Daly in 2013, and opened offices in Boston in 2017.
The digital platform, which last year received vital FDA clearance for the US market, not only ensures that patients keep up with their injectable treatments, but also allows them to dispose of medication in a safe way, and keeps carers up to date with the patients' progress.
The funding from this Series A will be used to launch its Smart Sharps system in the US and to develop its portfolio of medical adherence tools for high-value medications.
In 2017, HealthBeacon revealed plans to create 20 new jobs in Dublinin roles spanning IT, software development, project management and customer service. As of today, HealthBeacon operates in 10 markets and has tracked more than 200,000 home-based injections, making it one of the largest global deployments of a medical adherence device. Today, HealthBeacon employs more than 30 people and plans to double the team over the next 18 months.
The addressable market for injectable medications has reached nearly $50bn, according to the company. The Smart Sharps bin system by HealthBeacon has made it easier for patients using injectable medications to stay on track with their treatment. This has resulted in improved patient medication adherence, driving patient care.
In December, HealthBeacon was named eHealth Innovation of the Year by the Irish Medtech Association.
"I've been using the HealthBeacon for over two years, and their Smart Sharps bin has had a profound impact on how patients manage their treatment," said Doug Veale, professor of rheumatology at St Vincent's Hospital in Dublin.
"I know with confidence as to whether my patients are adhering to their treatment strategy."
Editor John Kennedy is an award-winning technology journalist.
https://www.siliconrepublic.com/start-ups/healthbeacon-series-a-investment
#JPM19 Conference: Lilly Announces Agreement To Acquire Loxo Oncology
37th Annual J.P. Morgan HEALTHCARE CONFERENCE: #JPM2019 for Jan. 8, 2019; Opening Videos, Novartis expands Cell Therapies, January 7 – 10, 2019, Westin St. Francis Hotel | San Francisco, California
37th Annual J.P. Morgan HEALTHCARE CONFERENCE: News at #JPM2019 for Jan. 8, 2019: Deals and Announcements
Posted in Breast Cancer - impalpable breast lesions, Cancer - General, Cancer and Current Therapeutics, CANCER BIOLOGY & Innovations in Cancer Therapy, Cancer Prevention: Research & Programs, Patient Experience, Patient Outlook, tagged Cancer, Cancer research, health, healthcare, innovation in health, innovation in healthcare on December 24, 2018| 1 Comment »
Following are a sampling of several relevant articles comprising health innovation and technology, which may ultimately lead to a good patient experience.
When a health journalist found out her 4-year-old son had a brain tumor, her family faced an urgent choice: proven but punishing rounds of chemotherapy, or a twice-a-day pill of a new "targeted" therapy with a scant track record.
https://www.reuters.com/investigates/special-report/genomics-tumor/
Paying for Tumor Testing
A recent U.S. government decision about coverage of tumor sequencing could affect cancer patients.
https://www.cancertodaymag.org/Pages/cancer-talk/Paying-for-Tumor-Testing.aspx
Dr. Elaine Schattner has authored numerous articles on cancer — as a doctor and patient. She is a freelance journalist and former oncologist who lives in New York City. She is writing a book about public attitudes toward cancer.
A life-long patient with scoliosis and other chronic medical conditions, and a history of breast cancer, Elaine's current interests include physicians' health, cancer, and medical journalism.
https://www.elaineschattner.com/
Speaking Up for Patient Preferences in Cancer Treatment Decisions.
Informed consent should include your input.
https://health.usnews.com/health-news/patient-advice/articles/2016-04-15/speaking-up-for-patient-preferences-in-cancer-treatment-decisions
Breast Cancer, Risk And Women's Imperfect Choices
https://www.npr.org/sections/health-shots/2013/05/15/184188710/breast-cancer-risk-and-womens-imperfect-choices
A cancer researchers takes cancer personally: Dr. Tony Blau, who started All4Cure, an online platform for myeloma clinicians and researchers to interact directly with patients to come up with a customer treatment plan.
Julia Louis-Dreyfus Acts Out: The actress on challenging comedy's sexism, fighting cancer, and becoming the star of her own show.
https://www.newyorker.com/magazine/2018/12/17/julia-louis-dreyfus-acts-out
Thanks to Wendy Lund, CEO of GCI Health (gcihealth.com) and her team for compiling part of this list.
Interoperability, patient matching could be fixed by smartphone apps, RAND says: Patients need quality information. A physician at George Washington University School of Medicine and Health Sciences believes that the healthcare community must improve reports by making them more accessible to patients.
https://www.healthcareitnews.com/news/interoperability-patient-matching-could-be-fixed-smartphone-apps-rand-says
Sometimes Patients Simply Need Other Patients: Finding a support community is also getting easier, through resources like the Database of Patients' Experiences, which houses videos of patients speaking about their experiences.
At These Hotels and Spas, Cancer is No Obstacle to Quality Care: A trend among spas and wellness resorts shows the increasing integration of safe wellness treatment options for cancer patients.
Posted in Cancer - General, Cancer and Current Therapeutics, Cancer Screening, Patient Experience, Patient Outlook, tagged Cancer, Cancer research, health, Health care, science on December 24, 2018| Leave a Comment »
The National Cancer Research Institute (NCRI) identified top 10 research priorities for people living with cancer to consider to improve treatment and quality of life.
By 2030 four million people in the UK will be living with the long-term consequences of cancer, but currently there is very little research on the problems they face and how these can be tackled. To help them live better lives, more focused research is needed.
To determine priorities for research that will help people live better with and beyond cancer, NCRI partnered with the James Lind Alliance on a Priority Setting Partnership. The two-year project involved two UK-wide surveys which attracted more than 3500 responses from patients, carers, and health and social care professionals. From these, we identified 26 key questions and distilled these down to 10 top research priorities.
This is the first time that clear research priorities have been identified in this area.
Questions 1 – 10 Questions 11 – 26
What are the best models for delivering long-term cancer care including screening, diagnosing and managing long-term side effects and late-effects of cancer and its treatment (e.g. primary and secondary care, voluntary organisations, self-management, carer involvement, use of digital technology, etc)?
How can patients and carers be appropriately informed of cancer diagnosis, treatment, prognosis, long-term side-effects and late effects of treatments, and how does this affect their treatment choices?
How can care be better co-ordinated for people living with and beyond cancer who have complex needs (with more than one health problem or receiving care from more than one specialty)?
What causes fatigue in people living with and beyond cancer and what are the best ways to manage it?
What are the short-term and long-term psychological impacts of cancer and its treatment and what are the most effective ways of supporting the psychological wellbeing of all people living with and beyond cancer, their carers and families?
How can the short-term, long-term and late effects of cancer treatments be (a) prevented, and/or (b) best treated/ managed?
What are the biological bases of side-effects of cancer treatment and how can a better understanding lead to improved ways to manage side-effects?
What are the best ways to manage persistent pain caused by cancer or cancer treatments?
What specific lifestyle changes (e.g. diet, exercise and stress reduction) help with recovery from treatment, restore health and improve quality of life?
How can we predict which people living with and beyond cancer will experience long-term side-effects (side-effects which last for years after treatment) and which people will experience late effects (side-effects which do not appear until years after treatment)?
https://www.ncri.org.uk/lwbc/
Low Health Literacy Among Older Americans: How Do You Make Proper Health Care Decisions?
Posted in Healthcare costs and reimbursement, Healthcare Reform, Patient Experience, Patient Outlook, tagged health, healthcare, lifestyle, science on December 24, 2018| Leave a Comment »
More than half of older Americans have "basic" or "below basic" health literacy. How do you make health care decisions when you don't even understand what the doctor is saying?
From The New York Times
This Type of Illiteracy Could Hurt You
More than half of older Americans lack the skills to gather and understand medical information. Providers must simplify, researchers say.
By Paula Span
Every time her parents pick up a new prescription at a Walgreens in Houston, they follow Duyen Pham-Madden's standing instructions: Use the iPad she bought for them, log onto FaceTime, hold up the pill bottles for her examination.
Her mother, 79, and father, 77, need numerous medications, but have trouble grasping when and how to take them.
The label may say to take one pill three times a day, but "my dad might take one a day," said Ms. Pham-Madden, 56, an insurance purchasing agent in Blue Springs, Mo. "Or take three at a time."
So she interprets the directions for them, also reminding her mother to take the prescribed megadose of vitamin D, for osteoporosis, only weekly, not daily.
Part of their struggle, Ms. Pham-Madden believes, stems from language barriers. The family emigrated from Vietnam in 1975, and while her parents speak and read English, they lack the fluency of native speakers.
But recently, Ms. Pham-Madden said, her father posed a question that anyone grappling with Medicare drug coverage might ask: "What's the doughnut hole?"
Researchers refer to this type of knowledge as "health literacy," meaning a person's ability to obtain and understand the basic information needed to make appropriate health decisions.
Can someone read a pamphlet and then determine how often to undergo a particular medical test? Look at a graph and recognize a normal weight range for her height? Ascertain whether her insurance will cover a certain procedure?
Most American adults — 53 percent — have intermediate health literacy, a national survey found in 2006; they can perform "moderately challenging" activities, like reading denser texts and handling unfamiliar arithmetic.
Just 12 percent rank as "proficient," the highest category. About a fifth have "basic" health literacy that could cause problems, and 14 percent score "below basic." Health literacy differs by education level, race, poverty and other factors.
And it varies dramatically by age. While the proportion of adults with intermediate literacy ranges from 53 to 58 percent in other age groups, it falls to 38 percent among those 65 and older. The percentage of older adults with basic or below basic literacy is higher than in any other age group; only 3 percent qualify as proficient.
Why is that? Compared to younger groups, the current generation of "older adults were less likely to go beyond a high school education," said Jennifer Wolff, a health services researcher at Johns Hopkins University.
Moreover, "as adults age, they're more likely to experience cognitive impairment," she pointed out, as well as hearing and vision loss that can affect their comprehension.
Consider the recent experience of a retired 84-year-old teacher. All her life, "she was very detail-oriented" and competent, said her daughter, Deborah Johnson, who lives in Lansing, Mich.
But a neurologist diagnosed mild cognitive impairment last summer and prescribed a drug intended to ameliorate its symptoms. It caused a frightening reaction — personality changes, lethargy, dizziness, sky-high blood pressure.
Ms. Johnson thinks her mother might have overdosed. "She told me she thought, 'This is going to fix me, and I'll be O.K. So if I take more pills, I'll be O.K. faster.'"
Yet health literacy can be particularly crucial for seniors. They're usually coping with more complicated medical problems, including multiple chronic diseases, an array of drugs, a host of specialists. They have more instructions to decipher, more tests to schedule, more decisions to ponder.
Low health literacy makes those tasks more difficult, with troubling results. Studies indicate that people with low literacy have poorer health at higher cost. They're less likely to take advantage of preventive tests and immunizations, and more apt to be hospitalized.
It may not help much that future cohorts of older adults will be better educated. "The demands of interacting with the health care system are increasing," Dr. Wolff said. "Ask any adult child of a parent who's been hospitalized. The system has gotten increasingly complex."
That doesn't mean patients deserve all the blame for misunderstandings and snafus. Rima Rudd, a longtime health literacy researcher at Harvard University, has persistently criticized the communications skills of health institutions and professionals.
"We give people findings and tell them about risk and expect people to make decisions based on those concepts, but we don't explain them very well," she said. "Are our forms readable? Are the directions after surgery written coherently? If it's written in jargon, with confusing words and numbers, you won't get the gist of it and you won't get important information."
A few years ago, Steven Rosen, 64, had spent more than two months at a Chicago hospital after several surgeries. Then a social worker came into his room and told his wife Dorothy, "You have to move him tomorrow to an L.T.A.C."
"I don't know what you're talking about," Ms. Rosen recalled saying. "What's an L.T.A.C.?"
Question: Was she demonstrating inadequate health literacy, or should the social worker have clarified that L.T.A.C.s — long-term acute care hospitals — provide more care than nursing homes for very ill patients?
Aware of such issues, health care organizations are scrambling to try to make information more accessible and intelligible, and to help patients of all ages understand an often bewildering environment.
They're hiring squadrons of care coordinators and navigators (sometimes too many), and redesigning and rewriting pamphlets and forms. They're teaching medical students to communicate more clearly and to encourage patients' questions.
They're turning to technology, like secure websites where both patients and family members can see test results or ask questions.
"It's not the silver bullet we hoped for," said Amy Chesser, a health communications researcher at Wichita State University, pointing out that many patients are reluctant to turn to provider websites. But the potential remains.
For now, though, often the primary health literacy navigators for older people are their adult children, most commonly daughters and daughters-in-law.
"In the best of all worlds, she'd just be the daughter," Dr. Chesser said. "But we need her to serve other roles — being an advocate, asking a lot of questions of the provider, asking where to go for information, talking about second opinions."
The current cohort of people over 70 grew up in a more patriarchal medical system and asking fewer questions, Dr. Wolff pointed out. Her research shows that while most seniors manage their own health care, about a third prefer to co-manage with family or close friends, or to delegate health matters to family or doctors.
Duyen Pham-Madden plays the co-managerial role from hundreds of miles away, keeping spreadsheets of her parents' drugs, compiling lists of questions for doctors' appointments, texting photos to pharmacists when the pills in a refilled prescription look different from the last batch.
She'd probably score well in health literacy, but "sometimes even I get mixed up," she said.
What's the Medicare doughnut hole? "I had to look it up," she said. Once she did, she wondered, "How do they expect seniors to understand this?"
Fiber Choice® Chewable Prebiotic Fiber Supplement Achieves #1-Recommended Status From Gastroenterologists Nationwide
Posted in Fat soluble vitamins, Gastroenterology, Nutrition, Nutritional Supplements: Atherogenesis, Personal Health Applications: Tech Innovations serves HealhCare, Uncategorized, tagged gastrointestinal, health, Nutrition, Nutritional Supplements, physician-patient relationship on June 3, 2018| Leave a Comment »
Curator: Gail S. Thornton, M.A.
Co-Editor: The VOICES of Patients, Hospital CEOs, HealthCare Providers, Caregivers and Families: Personal Experience with Critical Care and Invasive Medical Procedures
In a national survey, the Fiber Choice® line of chewable prebiotic fiber tablets and gummies, achieved the #1 share of gastroenterologist (GE) recommendations, more than four times greater than that for the nearest branded competitor
Fiber Choice contains a well-studied prebiotic fiber that promotes regularity and supports the growth of beneficial microorganisms for general digestive health
The convenience, taste and efficacy of Fiber Choice, makes it a GE-endorsed choice toward helping address the "fiber gap" in American diets
Boca Raton, Fla. – (June 3, 2018) – IM HealthScience® (IMH), innovators of medical foods and dietary supplements, today announced a high-quality and replicated nationwide survey conducted among a representative and projectible sample of U.S. gastroenterologists, which revealed Fiber Choice® as the #1-recommended chewable prebiotic fiber brand.
The results of a ProVoice survey, fielded in May 2018 by IQVIA, showed Fiber Choice as the leader by far. Its share of gastroenterologist endorsements was more than four times greater than that of its nearest branded competitor.
Less than 3 percent of Americans get the recommended minimum amount of fiber, and 97 percent need to increase their fiber intake[1]. Although the recommended daily fiber intake is 25 to 38 grams[2], most Americans only get about half that amount. This "fiber gap" reflects a diet with relatively few high-fiber foods, such as fruits, vegetables, nuts, legumes and whole-grains, and is large enough for the U.S. government to deem it a public health concern for most of the U.S. population.
To help bridge this gap, gastroenterologists recommend fibers including Fiber Choice chewable tablets and gummies. For doctors, it's a simple, convenient and tasty way to help their patients get the fiber needed for overall good digestive health.
"Dietary fiber is known for keeping our bodies regular," said Michael Epstein, M.D., FACG, AGAF, a leading gastroenterologist and Chief Medical Advisor of IM HealthScience. "Most importantly, it's essential that you get enough fiber in your diet. One way to do that is to supplement your daily intake of dietary fiber with natural, prebiotic fiber supplements."
Inulin, the 100 percent natural prebiotic soluble fiber in Fiber Choice, has been studied extensively and has been shown to support laxation and overall digestive health as well as glycemic control, lowered cholesterol, improved cardiovascular health, weight control and better calcium absorption.
Fiber Choice can be found in the digestive aisle at Walmart, CVS, Target, Rite Aid and many other drug and food retailers.
About ProVoice Survey
ProVoice has the largest sample size of any professional healthcare survey in the U.S., with nearly 60,000 respondents across physicians, nurse practitioners, physician assistants, optometrists, dentists, and hygienists, measuring recommendations across more than 120 over-the-counter categories. Manufacturers use ProVoice for claim substantiation, promotion measurement, and HCP targeting.
IQVIA fielded replicated surveys in April 2018 and May 2018 respectively among U.S. gastroenterologists for IM HealthScience. The ProVoice survey methodology validated the claim at a 95 percent confidence level that "Fiber Choice® is the #1 gastroenterologist-recommended chewable prebiotic fiber supplement."
About Fiber Choice®
The Fiber Choice® brand of chewables and gummies is made of inulin [pronounced: in-yoo-lin], a natural fiber found in many fruits and vegetables. Inulin works by helping to build healthy, good bacteria in the colon, while keeping food moving through the digestive system. This action has a beneficial and favorable effect in softening stools and improving bowel function.
Research shows that the digestive system does more than digest food; it plays a central role in the immune system. The healthy bacteria that live in the digestive tract promote immune system function, so prebiotic fiber helps nourish the body. Inulin also has secondary benefits, too, of possibly lowering cholesterol, balancing blood chemistry and regulating appetite, which can help reduce calorie intake and play a supporting role in weight management.
The usual adult dosage with Fiber Choice Chewable tablets is two tablets up to three times a day and for Fiber Choice Fiber Gummies is two gummies up to six per day.
About IM HealthScience®
IM HealthScience® (IMH) is the innovator of IBgard and FDgard for the dietary management of Irritable Bowel Syndrome (IBS) and Functional Dyspepsia (FD), respectively. In 2017, IMH added Fiber Choice®, a line of prebiotic fibers, to its product line via an acquisition. The sister subsidiary of IMH, Physician's Seal®, also provides REMfresh®, a well-known continuous release and absorption melatonin (CRA-melatonin™) supplement for sleep. IMH is a privately held company based in Boca Raton, Florida. It was founded in 2010 by a team of highly experienced pharmaceutical research and development and management executives. The company is dedicated to developing products to address overall health and wellness, including conditions with a high unmet medical need, such as digestive health. The IM HealthScience advantage comes from developing products based on its patented, targeted-delivery technologies called Site Specific Targeting (SST). For more information, visit www.imhealthscience.com to learn about the company, or www.IBgard.com, www.FDgard.com, www.FiberChoice.com, and www.Remfresh.com.
This information is for educational purposes only and is not meant to be a substitute for the advice of a physician or other health care professional. You should not use this information for diagnosing a health problem or disease. The company will strive to keep information current and consistent but may not be able to do so at any specific time. Generally, the most current information can be found on www.fiberchoice.com. Individual results may vary.
SOURCE/REFERENCES
[1] Greger, Michael, M.D., FACLM. (2015, September 29). Where Do You Get Your Fiber? [Blog post]. Retrieved from https://nutritionfacts.org/2015/09/29/where-do-you-get-your-fiber/
[2] Institute of Medicine. 2005. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press. https://doi.org/10.17226/10490.
Other related articles published in this Open Access Online Scientific Journal include the following:
Benefits of fiber in diet
https://pharmaceuticalintelligence.com/2018/03/14/benefits-of-fiber-in-diet/
Nutrition & Aging: Dr. Simin Meydani appointed Vice Provost for Research @Tufts University
https://pharmaceuticalintelligence.com/2016/08/01/nutrition-aging-dr-simin-meydani-appointed-vice-provost-for-research-tufts-university/
https://pharmaceuticalintelligence.com/2015/11/18/nutrition-plan/
Multivitamins – Don't help Extend Life or ward off Heart Disease and Improve state of Memory Loss
https://pharmaceuticalintelligence.com/2013/12/31/multivitamins-dont-help-extend-life-or-ward-off-heart-disease-and-improve-state-of-memory-loss/
Increased Consumption of Dietary Fiber is associated with a significantly Lower Risk of CVD and CHD
https://pharmaceuticalintelligence.com/2013/12/31/increased-consumption-of-dietary-fiber-is-associated-with-a-significantly-lower-risk-of-cvd-and-chd/
Relation of Nutrition with Cardiovascular Health
Posted in Acute coronary syndrome, Acute Myocardial Infarction, Best evidence, Cardiac muscle regeneration, Cardiovascular Pharmacogenomics, Cardiovascular Research, Chemical Biology and its relations to Metabolic Disease, Nutrigenomics, Nutrition, Nutrition and Phytochemistry, Nutrition Disorders, Nutritional Supplements: Atherogenesis, Nutritional Supplements: Atherogenesis, lipid metabolism, tagged Atherosclerosis, cardiovascular, health, lifestyle, Nutrition on June 3, 2018| Leave a Comment »
Reporter and Curator: Dr. Sudipta Saha, Ph.D.
A heart-healthy diet has been the basis of atherosclerotic cardiovascular disease (ASCVD) prevention and treatment for decades. The potential cardiovascular (CV) benefits of specific individual components of the "food-ome" (defined as the vast array of foods and their constituents) are still incompletely understood, and nutritional science continues to evolve.
The scientific evidence base in nutrition is still to be established properly. It is because of the complex interplay between nutrients and other healthy lifestyle behaviours associated with changes in dietary habits. However, several controversial dietary patterns, foods, and nutrients have received significant media exposure and are stuck by hype.
Decades of research have significantly advanced our understanding of the role of diet in the prevention and treatment of ASCVD. The totality of evidence includes randomized controlled trials (RCTs), cohort studies, case-control studies, and case series / reports as well as systematic reviews and meta-analyses. Although a robust body of evidence from RCTs testing nutritional hypotheses is available, it is not feasible to obtain meaningful RCT data for all diet and health relationships.
Studying preventive diet effects on ASCVD outcomes requires many years because atherosclerosis develops over decades and may be cost-prohibitive for RCTs. Most RCTs are of relatively short duration and have limited sample sizes. Dietary RCTs are also limited by frequent lack of blinding to the intervention and confounding resulting from imperfect diet control (replacing 1 nutrient or food with another affects other aspects of the diet).
In addition, some diet and health relationships cannot be ethically evaluated. For example, it would be unethical to study the effects of certain nutrients (e.g., sodium, trans fat) on cardiovascular disease (CVD) morbidity and mortality because they increase major risk factors for CVD. Epidemiological studies have suggested associations among diet, ASCVD risk factors, and ASCVD events. Prospective cohort studies yield the strongest observational evidence because the measurement of dietary exposure precedes the development of the disease.
However, limitations of prospective observational studies include: imprecise exposure quantification; co-linearity among dietary exposures (e.g., dietary fiber tracks with magnesium and B vitamins); consumer bias, whereby consumption of a food or food category may be associated with non-dietary practices that are difficult to control (e.g., stress, sleep quality); residual confounding (some non-dietary risk factors are not measured); and effect modification (the dietary exposure varies according to individual/genetic characteristics).
It is important to highlight that many healthy nutrition behaviours occur with other healthy lifestyle behaviours (regular physical activity, adequate sleep, no smoking, among others), which may further confound results. Case-control studies are inexpensive, relatively easy to do, and can provide important insight about an association between an exposure and an outcome. However, the major limitation is how the study population is selected or how retrospective data are collected.
In nutrition studies that involve keeping a food diary or collecting food frequency information (i.e., recall or record), accurate memory and recording of food and nutrient intake over prolonged periods can be problematic and subject to error, especially before the diagnosis of disease.
The advent of mobile technology and food diaries may provide opportunities to improve accuracy of recording dietary intake and may lead to more robust evidence. Finally, nutrition science has been further complicated by the influences of funding from the private sector, which may have an influence on nutrition policies and practices.
So, the future health of the global population largely depends on a shift to healthier dietary patterns. Green leafy vegetables and antioxidant suppliments have significant cardio-protective properties when consumed daily. Plant-based proteins are significantly more heart-healthy compared to animal proteins.
However, in the search for the perfect dietary pattern and foods that provide miraculous benefits, consumers are vulnerable to unsubstantiated health benefit claims. As clinicians, it is important to stay abreast of the current scientific evidence to provide meaningful and effective nutrition guidance to patients for ASCVD risk reduction.
Available evidence supports CV benefits of nuts, olive oil and other liquid vegetable oils, plant-based diets and plant-based proteins, green leafy vegetables, and antioxidant-rich foods. Although juicing may be of benefit for individuals who would otherwise not consume adequate amounts of fresh fruits and vegetables, caution must be exercised to avoid excessive calorie intake. Juicing of fruits / vegetables with pulp removal increases calorie intake. Portion control is necessary to avoid weight gain and thus cardiovascular health.
There is currently no evidence to supplement regular intake of antioxidant dietary supplements. Gluten is an issue for those with gluten-related disorders, and it is important to be mindful of this in routine clinical practice; however, there is no evidence for CV or weight loss benefits, apart from the potential caloric restriction associated with a gluten free diet.
https://www.sciencedirect.com/science/article/pii/S0735109713060294?via%3Dihub
http://circ.ahajournals.org/content/119/8/1161
http://refhub.elsevier.com/S0735-1097(17)30036-0/sref6
https://www.scopus.com/record/display.uri?eid=2-s2.0-0031709841&origin=inward&txGid=af40773f7926694c7f319d91efdcd40c
https://www.magonlinelibrary.com/doi/10.12968/hosp.2000.61.4.1875
https://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2548255
https://pharmaceuticalintelligence.com/2018/05/31/supplements-offer-little-cv-benefit-and-some-are-linked-to-harm-in-j-am-coll-cardiol/
Ultra-Pure Melatonin Product Helps Maintain Sleep for Up to 7 Hours
Posted in Advanced Drug Manufacturing Technology, Biochemical pathways, Innovations, LPBI Group, e-Scientific Media, DFP, R&D-M3DP, R&D-Drug Discovery, US Patents: SOPs and Team Management, Melatonin & Circadian Regulation, Patient Experience, Uncategorized, tagged Business, health, Innovation, research, science, sleep, sleep2017; remfresh; sleep management; melatonin; sleep cycles on June 11, 2017| 3 Comments »
The role of melatonin is important in regulating natural sleep and wake cycles. Typically, melatonin levels decline with age, significantly decreasing after age 40. An estimated 50 to 70 million Americans are affected by sleep difficulties – a process regulated by melatonin — and long-term sleep deprivation has been associated with negative health consequences, including an increased risk of diabetes, hypertension, heart attack, stroke, obesity, and depression.
Clinical data from a new pharmacokinetic study suggests that REMfresh®, the first and only continuous release and absorption melatonin (CRA-melatonin), helps maintain sleep for up to 7 hours. REMfresh® contains 99 percent ultra-pure melatonin and is sourced in Western Europe, a factor that is significant and important to many sleep specialists.
Three research abstracts on the REMfresh® data were published in an online supplement in the journal, Sleep, and were presented recently at the 31st Annual Meeting of the Associated Professional Sleep Societies LLC (APSS).
Image SOURCE: Photograph courtesy of Physician's Seal®.
How REMfresh® Works
REMfresh® (CRA-melatonin) mimics the body's own 7-hour Mesa Wave™, a natural pattern of melatonin blood levels during a normal night's sleep cycle.
The study demonstrated the continuous release and absorption of 99 percent ultra-pure melatonin in REMfresh® (CRA-melatonin) was designed to induce sleep onset and provide continuous, lasting restorative sleep over 7 hours.
The scientifically advanced, patented formulation, called Ion Powered Pump (IPP™) technology, replicates the way in which the body naturally releases and absorbs melatonin, unlike conventional melatonin sleep products.
Since REMfresh® (CRA-melatonin) is not a drug, there is no drug hangover.
Image SOURCE: Diagram courtesy of Physician's Seal®.
Data Based on Scientifically Advanced Delivery Technology
According to the primary study author, David C. Brodner, M.D., "These study results represent an unparalleled breakthrough in drug-free, sleep maintenance that physicians and patients have been waiting for in a sleep product." Dr. Brodner is a sleep specialist who is double board-certified in Otolaryngology – Head and Neck Surgery and Sleep Medicine and is the founder and principle physician at the Center for Sinus, Allergy, and Sleep Wellness in Palm Beach County, Florida.
Dr. Brodner said, "Melatonin products have been used primarily as a chronobiotic to address sleep disorders, such as jet lag and shift work. The patented delivery system in REMfresh mimics the body's own natural sleep pattern, so individuals may experience consistent, restorative sleep and have an improved quality of life with this drug-free product."
Study Findings With REMAKT™
The study findings are based on REMAKT™ (REM Absorption Kinetics Trial), a U.S.-based randomized, crossover pharmacokinetic (PK) evaluation study in healthy, non-smoking adults that compared REMfresh® (CRA-melatonin) with a market-leading, immediate-release melatonin (IR-melatonin).
The study found that melatonin levels with REMfresh® exceeded the targeted sleep maintenance threshold for a median of 6.7 hours, compared with 3.7 hours with the leading IR-melatonin. Conversely, the levels of the market-leading IR-melatonin formulation dramatically increased 23 times greater than the targeted levels of exogenous melatonin for sleep maintenance and had a rapid decline in serum levels that did not allow melatonin levels to be maintained beyond 4 hours.
Additional analysis presented showed that REMfresh® (CRA-melatonin) builds upon the body of evidence from prolonged-release melatonin (PR-M), which demonstrated in well-conducted, placebo-controlled studies, statistically significant improvement in sleep quality, morning alertness, sleep latency and quality of life in patients aged 55 years and older compared with placebo.
REMfresh® (CRA-melatonin) was designed to overcome the challenges of absorption in the intestines, thereby extending the continual and gradual release pattern of melatonin through the night (known as the Mesa Wave™, a flat-topped hill with steep sides). There was a faster time to Cmax, which is anticipated to result in improved sleep onset, while the extended median plateau time to 6.7 hours and rapid fall-off in plasma levels at the end of the Mesa Wave™ may help to improve sleep maintenance and morning alertness.
REFERENCE/SOURCE
Physician's Seal® and REMfresh® (www.remfresh.com)
REMfresh® press release, June 5, 2017 (http://www.prnewswire.com/news-releases/scientifically-advanced-delivery-technology-in-sleep-management-debuts-at-sleep-2017-with-clinical-data-showing-remfresh-the-first-and-only-continuous-release-and-absorption-melatonin-helps-maintain-sleep-for-up-to-7-hours-300468218.html)
Dr. David C. Brodner, Center for Sinus, Allergy, and Sleep Wellness (http://www.brodnermd.com/sleep-hygiene.html)
Sleep Research Society announces 2017 award recipients including Thomas S. Kilduff, PhD, Director, Center for Neuroscience at SRI International in Menlo Park, California
https://pharmaceuticalintelligence.com/2017/04/28/sleep-research-society-announces-2017-award-recipients-including-thomas-s-kilduff-phd-director-center-for-neuroscience-at-sri-international-in-menlo-park-california/
https://pharmaceuticalintelligence.com/2016/03/16/sleep-science/
Genetic link to sleep and mood disorders
https://pharmaceuticalintelligence.com/2016/02/27/genetic-link-to-sleep-and-mood-disorders/
Sleep quality, amyloid and cognitive decline
https://pharmaceuticalintelligence.com/2015/10/31/sleep-quality-amyloid-and-cognitive-decline/
Day and Night Variation in Melatonin Level affects Plasma Membrane Redox System in Red Blood Cells
https://pharmaceuticalintelligence.com/2013/02/23/httpwww-ncbi-nlm-nih-govpubmed22561555/