Home-prepared meals among college students at-risk for food insecurity: A mixed-methods study.

The ability to prepare meals at home is an important life skill with potential to improve dietary quality and reduce costs and thus may be particularly important for college students with food insecurity. However, heavy time demands, limited financial resources, and therefore other barriers such as lack of motivation to follow a healthy diet may constrain meal preparation skills. To gain greater insight into this issue, we conducted a mixed-methods study. The quantitative component assessed relationships among food security, motivation, and meal preparation skills. The qualitative component used focus groups to more closely consider college students' perceptions, values, and barriers surrounding preparing meals at home, including current practices, desired future practices, and the ways in which the campus could support their efforts. The survey (n = 226) assessed food security, meal preparation skills, and motivation (i.e., perceived ability and willingness) to consume a healthy diet. Ten focus groups (n = 60) discussed food choice, meal preparation practices, and ways in which the campus could help students develop meal preparation skills. Students with food insecurity had lower meal preparation skills and lower perceived ability to consume a healthy diet. However, a) willingness to consume a healthy diet and b) the impact of both willingness and perceived ability did not differ by food security status. Focus group data indicated that in-person and online cooking classes, information cards in the food pantry, and incentives (e.g., kitchen equipment and vouchers from local grocery stores) were popular ideas for improving home-meal preparation. A greater understanding of meal preparation skills and their interconnectedness to food choice and the campus environment may inform effective ways to support the ability and willingness of college students with food insecurity to prepare meals at home.

Segmented assimilation as a mechanism to explain the dietary acculturation paradox.

Latinos have disproportionately high rates of diet-related diseases which are associated with acculturation to the U.S. This negative shift in dietary quality is paradoxical in light of gains in income and education that would be expected to lead to better diet. We examined the extent to which the dietary acculturation paradox among Mexican Americans can be explained by segmented assimilation, a theory that considers how immigrants' and their descendants' trajectories of integration are influenced by a complex interplay of individual, social, and structural factors. First, we performed confirmatory cluster analysis to identify three assimilation segments (classic, underclass, and selective) based on education, income, and an acculturation proxy derived from language, nativity, and time in the U.S. among Mexican-origin participants (N = 4475) of the 2007-2016 National Health and Nutrition Examination Survey (NHANES). These segments were then used as independent variables in linear regression models to estimate the relationship between cluster and dietary quality (assessed by the Health Eating Index (HEI)) and the interaction between cluster and gender, controlling for marital status. There were strong effects of cluster on dietary quality, consistent with hypotheses per segmented assimilation theory. The classic assimilation segment had the poorest diet, despite having higher income and education than the underclass segment. The selective segment had higher or similar dietary quality to the underclass segment. Consistent with expectations, this difference was driven by the relatively higher consumption of greens and beans and whole grains of those in the selective and underclass segments. Overall, women had better diets than men; however, the strongest gender contrast was in the underclass segment. This study advances understanding of dietary acculturation and potential disparities in diet-related health outcomes.

Copper stabilizes antiparallel ß-sheet fibrils of the amyloid ß40 (Aß40)-Iowa variant.

Cerebral amyloid angiopathy (CAA) is a vascular disorder that primarily involves deposition of the 40-residue-long ß-amyloid peptide (Aß40) in and along small blood vessels of the brain. CAA is often associated with Alzheimer's disease (AD), which is characterized by amyloid plaques in the brain parenchyma enriched in the Aß42 peptide. Several recent studies have suggested a structural origin that underlies the differences between the vascular amyloid deposits in CAA and the parenchymal plaques in AD. We previously have found that amyloid fibrils in vascular amyloid contain antiparallel ß-sheet, whereas previous studies by other researchers have reported parallel ß-sheet in fibrils from parenchymal amyloid. Using X-ray fluorescence microscopy, here we found that copper strongly co-localizes with vascular amyloid in human sporadic CAA and familial Iowa-type CAA brains compared with control brain blood vessels lacking amyloid deposits. We show that binding of Cu(II) ions to antiparallel fibrils can block the conversion of these fibrils to the more stable parallel, in-register conformation and enhances their ability to serve as templates for seeded growth. These results provide an explanation for how thermodynamically less stable antiparallel fibrils may form amyloid in or on cerebral vessels by using Cu(II) as a structural cofactor.

When Media Health Stories Conflict: Test of the Contradictory Health Information Processing (CHIP) Model.

Guided by Uncertainty Management Theory, UMT, we tested a model that explicates how uncertainty arising from contradictory health information is managed through information seeking. In an online experiment, 763 U.S. adults were randomly assigned to one of three message conditions: contradictory, non-contradictory, or control. Participants in the contradictory and non-contradictory conditions answered questions about their perceptions of contradiction, issue and decision uncertainty, negative appraisals and emotions, and information-seeking intentions. They also completed measures of several moderator variables, including information overload, intolerance for uncertainty, and health self-efficacy. Baseline levels of issue and decision uncertainty were measured in the control condition. Model tenets were confirmed: perceptions of contradiction led to issue uncertainty which, in turn, prompted cognitive appraisals directly, and indirectly through increased decision uncertainty. The effects of issue and decision uncertainty on information-seeking intentions were mediated by negative appraisals and threat emotions. Individuals with high health self-efficacy and positive outcome expectations of information search were more likely to manage uncertainty through information seeking. These results support the use of the CHIP model when perceptions of contradiction and decision uncertainty need to be accounted for, while also validating UMT for its original purposes. Model refinements and implications are discussed.

Lanthanide-Binding Tags for 3D X-ray Imaging of Proteins in Cells at Nanoscale Resolution.

We report the application of lanthanide-binding tags (LBTs) for two- and three-dimensional X-ray imaging of individual proteins in cells with a sub-15 nm beam. The method combines encoded LBTs, which are tags of minimal size (ca. 15-20 amino acids) affording high-affinity lanthanide ion binding, and X-ray fluorescence microscopy (XFM). This approach enables visualization of LBT-tagged proteins while simultaneously measuring the elemental distribution in cells at a spatial resolution necessary for visualizing cell membranes and eukaryotic subcellular organelles.

Complications From Tunneled Hemodialysis Catheters: A Canadian Observational Cohort Study.

RATIONALE & OBJECTIVE: Clinical practice guidelines discourage the use of central venous catheters (CVCs) for vascular access in dialysis. However, some patients have inadequate vessels for arteriovenous fistula creation or choose to use a dialysis catheter. The risks associated with CVC use and their relationship to patient age are poorly characterized. STUDY DESIGN: Observational retrospective cohort study. SETTING & PARTICIPANTS: Cohort of 1,041 patients older than 18 years from 5 Canadian dialysis programs who initiated outpatient maintenance hemodialysis therapy with a tunneled CVC between 2004 and 2012 and who had no creation of an arteriovenous fistula or arteriovenous graft. EXPOSURES: Age, sex, body size, initiating dialysis therapy in the hospital, and comorbid conditions. OUTCOMES: CVC-related procedures, hospitalization, and death. ANALYTICAL APPROACH: Complications were reported as a cumulative risk at 1 and 2 years. Cox proportional hazards regression for recurrent events was used to evaluate risk factors for study outcomes. RESULTS: At 1 year, risks for CVC-related bacteremia, malfunction, and central stenosis were 9%, 15%, and 2%, respectively. Risks for any CVC-related complication at 1 and 2 years were 30% and 38%, respectively. Death related to CVC complications occurred in 6 of 1,041 (0.5%) patients. Compared with patients younger than 60 years, patients aged 70 to 79 and those 80 years or older experienced lower rates of CVC complications: HRs of 0.67 (95% CI, 0.52-0.85; P = 0.001) and 0.69 (95% CI, 0.52-0.92; P = 0.01), respectively. LIMITATIONS: This Canadian dialysis population may not be representative of populations in other countries. CVC use was not compared with other types of hemodialysis vascular access. CONCLUSIONS: Approximately one-third of hemodialysis patients who used tunneled CVCs during 1 to 2 years experienced complications. Bacteremia occurred in ∼9% of patients at 1 year and were the most common cause of CVC-related hospitalizations. CVC-related death was infrequent. This information could be used to communicate the risk for CVC complications to patients treated with this type of hemodialysis vascular access.

Imaging Nutrient Distribution in the Rhizosphere Using FTIR Imaging.

Symbiotic associations in the rhizosphere between plants and microorganisms lead to efficient changes in the distribution of nutrients that promote growth and development for each organism involved. Understanding these nutrient fluxes provides insight into the molecular dynamics involved in nutrient transport from one organism to the other. To study such a nutrient flow, a new application of Fourier transform infrared imaging (FTIRI) was developed that entailed growing Populus tremulodes seedlings on a thin, nutrient-enriched Phytagel matrix that allows pixel to pixel measurement of the distribution of nutrients, in particular, nitrate, in the rhizosphere. The FTIR spectra collected from ammonium nitrate in the matrix indicated the greatest changes in the spectra at 1340 cm-1 due to the asymmetric stretching vibrations of nitrate. For quantification of the nitrate concentration in the rhizosphere of experimental plants, a calibration curve was generated that gave the nitrate concentration at each pixel in the chemical image. These images of the poplar rhizosphere showed evidence for symbiotic sharing of nutrients between the plant and the fungi, Laccaria bicolor, where the nitrate concentration was five times higher near mycorrhizal roots than further out into the rhizosphere. This suggested that nitrates are acquired and transported from the media toward the plant root by the fungi. Similarly, the sucrose used in the growth media as a carbon source was depleted around the fungi, suggesting its uptake and consumption by the system. This study is the first of its kind to visualize and quantify the nutrient availability associated with mycorrhizal interactions, indicating that FTIRI has the ability to monitor nutrient changes with other microorganisms in the rhizosphere as a key step for understanding nutrient flow processes in more diverse biological systems.

Age differences in the use of serving size information on food labels: numeracy or attention?

OBJECTIVE: The ability to use serving size information on food labels is important for managing age-related chronic conditions such as diabetes, obesity and cancer. Past research suggests that older adults are at risk for failing to accurately use this portion of the food label due to numeracy skills. However, the extent to which older adults pay attention to serving size information on packages is unclear. We compared the effects of numeracy and attention on age differences in accurate use of serving size information while individuals evaluated product healthfulness. DESIGN: Accuracy and attention were assessed across two tasks in which participants compared nutrition labels of two products to determine which was more healthful if they were to consume the entire package. Participants' eye movements were monitored as a measure of attention while they compared two products presented side-by-side on a computer screen. Numeracy as well as food label habits and nutrition knowledge were assessed using questionnaires. SETTING: Sacramento area, California, USA, 2013-2014. SUBJECTS: Stratified sample of 358 adults, aged 20-78 years. RESULTS: Accuracy declined with age among those older adults who paid less attention to serving size information. Although numeracy, nutrition knowledge and self-reported food label use supported accuracy, these factors did not influence age differences in accuracy. CONCLUSIONS: The data suggest that older adults are less accurate than younger adults in their use of serving size information. Age differences appear to be more related to lack of attention to serving size information than to numeracy skills.

Developing Nutrition Label Reading Skills: A Web-Based Practice Approach.

BACKGROUND: Nutrition labels offer the information needed to follow Dietary Guidelines for Americans, yet many individuals use labels infrequently or ineffectively due to limited comprehension and the effort required to use them. OBJECTIVE: The objective of our study was to develop and test a Web-based label-reading training tool to improve individuals' ability to use labels to select more healthful foods. We were particularly interested in determining whether practice can lead to increased accuracy using labels as well as decreased effort, together reflecting greater efficiency. We compared a basic and an enhanced, prior-knowledge version of the tool that contained an additional component, a brief nutrition tutorial. METHODS: Participants were 140 college students with an average age of 20.7 (SD 2.1) years and education 14.6 (SD 1.2) years, who completed 3 sets of practice that were designed to teach them, through repetition and feedback, how to use nutrition labels to select more healthful products. Prior to training, participants in the prior-knowledge group viewed a multimedia nutrition presentation, which those in the basic group did not receive. Mixed-effects models tested for improvement in accuracy and speed with practice, and whether improvements varied by group. RESULTS: The training led to significant increases in average accuracy across the 3 practice sets (averaging 79% [19/24 questions], 92% [22/24], 96% [23/24] respectively, P<.001), as well as decreases in time to complete with mean (SD) values of 8.7 (2.8), 4.6 (1.8), and 4.1 (1.7) seconds, respectively. In block 3, the odds of a correct answer for the prior-knowledge group were 79% higher (odds ratio, OR=1.79, 95% CI 1.1-2.9) than those for the basic group (P=.02). There was no significant difference between the groups in block 2 (P=.89). CONCLUSIONS: Practice led to improvements in nutrition label reading skills that are indicative of early stages of automatic processing. To the extent that automatic processes are at the core of healthy habit change, this may be an efficient way to improve dietary decision-making.

Bone Matrix Composition Following PTH Treatment is Not Dependent on Sclerostin Status.

Sclerostin and parathyroid hormones are strong negative and positive regulators of bone formation, respectively. The anabolic response induced by intermittent (iPTH) treatment is sclerostin status-dependent. However, the interaction between sclerostin and iPTH at the matrix level is unknown. The goal of the current study was to determine if iPTH treatment affects matrix composition and, if so, whether these effects are dependent on sclerostin status. Humeral trabecular and cortical bone sites from 16 week old male wild-type (WT) and sclerostin knockout (KO) mice, which had been treated with vehicle or iPTH from age 10-16 weeks, were examined by micro-computed tomography (µCT) to measure bone volume, backscatter scanning electron microscopy (bSEM) to assess global mineralization, and Fourier transform infrared microspectroscopy (FTIRM) to examine matrix composition (mineral-to-matrix ratio, crystallinity, collagen cross-link ratio, and carbonate substitution). The FTIRM measurements were restricted to the tissue formed during the 6-week treatment period. iPTH treatment led to increased trabecular bone volume (p < 0.001) and this effect was much greater in KO mice than WT mice (interaction effect, p < 0.001). iPTH treatment led to reduced trabecular crystallinity (p = 0.047), increased cortical bone area (p < 0.001), decreased cortical bone crystallinity (p = 0.002) and increased cortical bone collagen cross-linking (p = 0.028) to similar degrees in both WT and KO mice. Compared to WT mice, sclerostin KO mice had higher trabecular and cortical bone mass (p < 0.001) and lower mineral-to-matrix ratio in the trabecular (p = 0.010) and cortical (p = 0.016) compartments. Thus, iPTH-induced changes in bone mass are dependent upon sclerostin status in the trabecular compartment, but not in the cortical compartment. In contrast, iPTH-induced changes in matrix composition are sclerostin-independent in both trabecular and cortical compartments.

HBM Mice Have Altered Bone Matrix Composition and Improved Material Toughness.

The G171V mutation in the low-density lipoprotein receptor-related protein 5 (LRP5) leads to a high bone mass (HBM) phenotype. Studies using HBM transgenic mouse models have consistently found increased bone mass and whole-bone strength, but little attention has been paid to the composition of the bone matrix. The current study sought to determine if the cortical bone matrix composition differs in HBM and wild-type mice and to determine how much of the variance in bone material properties is explained by variance in matrix composition. Consistent with previous studies, HBM mice had greater cortical area, moment of inertia, ultimate force, bending stiffness, and energy to failure than wild-type animals. The increased energy to failure was primarily caused by a large increase in post-yield behavior, with no difference in pre-yield behavior. The HBM mice had increased mineral-to-matrix and collagen cross-link ratios, and decreased crystallinity, carbonate, and acid phosphate substitution as measured by Fourier transform infrared microspectroscopy, but no differences in crystal length, intra-fibular strains, and mineral spacing compared to wild-type controls, as measured by X-ray scattering. The largest between genotype difference in material properties was a twofold increase in the modulus of toughness in HBM mice. Step-wise regression analyses showed that the specific matrix compositional parameters most closely associated with material properties varied between the wild-type and HBM genotypes. Although the mechanisms controlling the paradoxical combination of more mineralized yet tougher bone in HBM mice remain to be fully explained, the findings suggest that LRP5 represents a target to not only build bone mass but also to improve bone quality.

Characterization of Protein Structural Changes in Living Cells Using Time-Lapsed FTIR Imaging.

Fourier-transform infrared (FTIR) spectroscopic imaging is a widely used method for studying the chemistry of proteins, lipids, and DNA in biological systems without the need for additional tagging or labeling. This technique can be especially powerful for spatially resolved, temporal studies of dynamic changes such as in vivo protein folding in cell culture models. However, FTIR imaging experiments have typically been limited to dry samples as a result of the significant spectral overlap between water and the protein Amide I band centered at 1650 cm(-1). Here, we demonstrate a method to rapidly obtain high quality FTIR spectral images at submicron pixel resolution in vivo over a duration of 18 h and longer through the development and use of a custom-built, demountable, microfluidic-incubator and a FTIR microscope coupled to a focal plane array (FPA) detector and a synchrotron light source. The combined system maximizes ease of use by allowing a user to perform standard cell culture techniques and experimental manipulation outside of the microfluidic-incubator, where assembly can be done just before the start of experimentation. The microfluidic-incubator provides an optimal path length of 6-8 µm and a submillimeter working distance in order to obtain FTIR images with 0.54-0.77 µm pixel resolution. In addition, we demonstrate a novel method for the correction of spectral distortions caused by varying concentrations of water over a subconfluent field of cells. Lastly, we use the microfluidic-incubator and time-lapsed FTIR imaging to determine the misfolding pathway of mutant copper-zinc superoxide dismutase (SOD1), the protein known to be a cause of familial amyotrophic lateral sclerosis (FALS).

Acetylesterase-mediated deacetylation of pectin impairs cell elongation, pollen germination, and plant reproduction.

Pectin is a major component of the primary cell wall of higher plants. Some galacturonyl residues in the backbone of pectinaceous polysaccharides are often O-acetylated at the C-2 or C-3 position, and the resulting acetylesters change dynamically during the growth and development of plants. The processes involve both enzymatic acetylation and deacetylation. Through genomic sequence analysis, we identified a pectin acetylesterase (PAE1) from black cottonwood (Populus trichocarpa). Recombinant Pt PAE1 exhibited preferential activity in releasing the acetate moiety from sugar beet (Beta vulgaris) and potato (Solanum tuberosum) pectin in vitro. Overexpressing Pt PAE1 in tobacco (Nicotiana tabacum) decreased the level of acetyl esters of pectin but not of xylan. Deacetylation engendered differential changes in the composition and/or structure of cell wall polysaccharides that subsequently impaired the cellular elongation of floral styles and filaments, the germination of pollen grains, and the growth of pollen tubes. Consequently, plants overexpressing PAE1 exhibited severe male sterility. Furthermore, in contrast to the conventional view, PAE1-mediated deacetylation substantially lowered the digestibility of pectin. Our data suggest that pectin acetylesterase functions as an important structural regulator in planta by modulating the precise status of pectin acetylation to affect the remodeling and physiochemical properties of the cell wall's polysaccharides, thereby affecting cell extensibility.

Intra-amniotic IL-1ß induces fetal inflammation in rhesus monkeys and alters the regulatory T cell/IL-17 balance.

Very low birth weight preterm newborns are susceptible to the development of debilitating inflammatory diseases, many of which are associated with chorioamnionitis. To define the effects of chorioamnionitis on the fetal immune system, IL-1ß was administered intra-amniotically at ~80% gestation in rhesus monkeys. IL-1ß caused histological chorioamnionitis, as well as lung inflammation (infiltration of neutrophils or monocytes in the fetal airways). There were large increases in multiple proinflammatory cytokine mRNAs in the lungs at 24 h postadministration, which remained elevated relative to controls at 72 h. Intra-amniotic IL-1ß also induced the sustained expression of the surfactant proteins in the lungs. Importantly, IL-1ß significantly altered the balance between inflammatory and regulatory T cells. Twenty-four hours after IL-1ß injection, the frequency of CD3(+)CD4(+)FOXP3(+) T cells was decreased in lymphoid organs. In contrast, IL-17A-producing cells (CD3(+)CD4(+), CD3(+)CD4(-), and CD3(-)CD4(-) subsets) were increased in lymphoid organs. The frequency of IFN-γ-expressing cells did not change. In this model of a single exposure to an inflammatory trigger, CD3(+)CD4(+)FOXP3(+) cells rebounded quickly, and their frequency was increased at 72 h compared with controls. IL-17 expression was also transient. Interestingly, the T cell profile alteration was confined to the lymphoid organs and not to circulating fetal T cells. Together, these results suggest that the chorioamnionitis-induced IL-1/IL-17 axis is involved in the severe inflammation that can develop in preterm newborns. Boosting regulatory T cells and/or controlling IL-17 may provide a means to ameliorate these abnormalities.

The effects of nutrition knowledge on food label use. A review of the literature.

Nutrition information on food labels is an important source of nutrition information but is typically underutilized by consumers. This review examined whether consumer nutrition knowledge is important for communication of nutrition information through labels on packaged foods. A cognitive processing model posits that consumers with prior knowledge are more likely to use label information effectively, that is, focus on salient information, understand information, and make healthful decisions based on this information. Consistent with this model, the review found that nutrition knowledge provides support for food label use. However, nutrition knowledge measures varied widely in terms of the dimensions they included and the extensiveness of the assessment. Relatively few studies investigated knowledge effects on the use of ingredient lists and claims, compared to nutrition facts labels. We also found an overreliance on convenience samples relying on younger adults, limiting our understanding of how knowledge supports food label use in later life. Future research should 1) investigate which dimensions, or forms, of nutrition knowledge are most critical to food label use and dietary decision making and 2) determine whether increases in nutrition knowledge can promote great use of nutrition information on food labels.

The eHealth Enhanced Chronic Care Model: a theory derivation approach.

BACKGROUND: Chronic illnesses are significant to individuals and costly to society. When systematically implemented, the well-established and tested Chronic Care Model (CCM) is shown to improve health outcomes for people with chronic conditions. Since the development of the original CCM, tremendous information management, communication, and technology advancements have been established. An opportunity exists to improve the time-honored CCM with clinically efficacious eHealth tools. OBJECTIVE: The first goal of this paper was to review research on eHealth tools that support self-management of chronic disease using the CCM. The second goal was to present a revised model, the eHealth Enhanced Chronic Care Model (eCCM), to show how eHealth tools can be used to increase efficiency of how patients manage their own chronic illnesses. METHODS: Using Theory Derivation processes, we identified a "parent theory", the Chronic Care Model, and conducted a thorough review of the literature using CINAHL, Medline, OVID, EMBASE PsychINFO, Science Direct, as well as government reports, industry reports, legislation using search terms "CCM or Chronic Care Model" AND "eHealth" or the specific identified components of eHealth. Additionally, "Chronic Illness Self-management support" AND "Technology" AND several identified eHealth tools were also used as search terms. We then used a review of the literature and specific components of the CCM to create the eCCM. RESULTS: We identified 260 papers at the intersection of technology, chronic disease self-management support, the CCM, and eHealth and organized a high-quality subset (n=95) using the components of CCM, self-management support, delivery system design, clinical decision support, and clinical information systems. In general, results showed that eHealth tools make important contributions to chronic care and the CCM but that the model requires modification in several key areas. Specifically, (1) eHealth education is critical for self-care, (2) eHealth support needs to be placed within the context of community and enhanced with the benefits of the eCommunity or virtual communities, and (3) a complete feedback loop is needed to assure productive technology-based interactions between the patient and provider. CONCLUSIONS: The revised model, eCCM, offers insight into the role of eHealth tools in self-management support for people with chronic conditions. Additional research and testing of the eCCM are the logical next steps.

e-Patients Perceptions of Using Personal Health Records for Self-management Support of Chronic Illness.

Chronic illness self-management is largely moving from healthcare professionals and into the hands of the patient. One tool that has been promoted to facilitate self-management support of chronic illness by policymakers, health advocates, providers, and consumers is the personal health record. Little is known about how consumers effectively use personal health records for self-management support and for productive patient-provider interactions. The purpose of this study was to learn from chronically ill engaged, experienced, and educated (e-patient) adults how and why they use personal health records for self-management support and productive patient-provider interactions. Eighteen purposively selected consumers were interviewed in two communities. Qualitative description methods were used, and we used a grounded theory approach to analyzing interview data, which was digitally recorded and transcribed verbatim. We identified four major thematic categories that capture the perceptions of the chronically ill using personal health records: (1) patient engagement and health self-management, (2) access to and control over personal health data, (3) promotion of productive communication, and (4) opportunities for training and education. Knowledge gained from the e-patient personal health record users suggest that making improvements to the portal system and providing education to consumers and providers will increase the utility among the experienced users and encourage new users to embrace adoption and use.

FTIR spectroscopic imaging of protein aggregation in living cells.

Protein misfolding and aggregation are the hallmark of a number of diseases including Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and the prion diseases. In all cases, a naturally-occurring protein misfolds and forms aggregates that are thought to disrupt cell function through a wide range of mechanisms that are yet to be fully unraveled. Fourier transform infrared (FTIR) spectroscopy is a technique that is sensitive to the secondary structure of proteins and has been widely used to investigate the process of misfolding and aggregate formation. This review focuses on how FTIR spectroscopy and spectroscopic microscopy are being used to evaluate the structural changes in disease-related proteins both in vitro and directly within cells and tissues. Finally, ongoing technological advances will be presented that are enabling time-resolved FTIR imaging of protein aggregation directly within living cells, which can provide insight into the structural intermediates, time scale, and mechanisms of cell toxicity associated with aggregate formation. This article is part of a Special Issue entitled: FTIR in membrane proteins and peptide studies.

Alterations in collagen and mineral nanostructure observed in osteoporosis and pharmaceutical treatments using simultaneous small- and wide-angle X-ray scattering.

The influence of the macroscale material properties of bone on its mechanical competence has been extensively investigated, but less is known about possible contributions from bone's nanoscale material properties. These nanoscale properties, particularly the collagen network and the size and shape of hydroxyapatite mineral crystals, may be affected by aging, mechanical loading, and diseases including osteoporosis. Here, changes to the collagen and mineral properties of cortical bone induced by osteoporosis and subsequent pharmaceutical treatments were investigated by simultaneous small- and wide-angle X-ray scattering (SAXS/WAXS) microbeam mapping. Adult rats (6 months old) were ovariectomized and treated with alendronate, parathyroid hormone, or sodium fluoride, and compared to untreated ovariectomized and age-matched controls. Scattering data from tibial cortical bone showed that osteoporosis increased collagen alignment in existing intracortical bone, while this effect was mitigated in the alendronate and sodium fluoride groups though by different mechanisms. Further, mineral crystal lengths in newly formed cortical bone were smaller in animals with osteoporosis, but existing cortical bone was not altered. Subsequent treatment with alendronate mitigated changes in crystal lengths. Together, these results suggest that osteoporosis may alter the collagen alignment and mineral geometry in bone formed before and after the onset of this disease, and that osteoporosis treatments may differentially rescue these changes.

The association between geographic proximity to a dialysis facility and use of dialysis catheters.

BACKGROUND: Residing remotely from health care resources appears to impact quality of care delivery. It remains unclear if there are differences in vascular access based on distance of one's residence to dialysis centre at time of dialysis initiation, and whether region or duration of pre-dialysis care are important effect modifiers. METHODS: We studied the association of distance from a patients' residence to the nearest dialysis centre and central venous catheter (CVC) use in an observational study of 26,449 incident adult dialysis patients registered in the Canadian Organ Replacement Registry between 2000-2009. Multivariate logistic regression was used to assess the association between distance in tertiles and CVC use, adjusted for patient demographics and comorbidities. Geographic region and duration of pre-dialysis care were examined as potential effect modifiers. RESULTS: Eighty percent of patients commenced dialysis with a CVC. Incident CVC use was highest among those living > 20 km from the dialysis centre (OR 1.29 (1.24-1.34)) compared to those living < 5 km from centre. The length of pre-dialysis care and geographic region were significant effect modifiers; among patients residing in the furthest tertile (>20 km) from the nearest dialysis centre, incident CVC use was more common with shorter length of pre-dialysis care (< 1 year) and residence in central regions of the country. CONCLUSION: Residing further from a dialysis centre is associated with increased CVC use, an effect modified by shorter pre-dialysis care and the geographic region of the country. Efforts to reduce geographical disparities in pre dialysis care may decrease CVC use.