Search

Background: Spaceflight poses a unique set of challenges to humans and the hostile spaceflight environment can induce a wide range of increased health risks, including dermatological issues. The biology driving the frequency of skin issues in astronauts is currently not well understood., Methods: To address this issue, we used a systems biology approach utilizing NASA's Open Science Data Repository (OSDR) on space flown murine transcriptomic datasets focused on the skin, biochemical profiles of 50 NASA astronauts and human transcriptomic datasets generated from blood and hair samples of JAXA astronauts, as well as blood samples obtained from the NASA Twins Study, and skin and blood samples from the first civilian commercial mission, Inspiration4., Results: Key biological changes related to skin health, DNA damage & repair, and mitochondrial dysregulation are identified as potential drivers for skin health risks during spaceflight. Additionally, a machine learning model is utilized to determine gene pairings associated with spaceflight response in the skin. While we identified spaceflight-induced dysregulation, such as alterations in genes associated with skin barrier function and collagen formation, our results also highlight the remarkable ability for organisms to re-adapt back to Earth via post-flight re-tuning of gene expression., Conclusion: Our findings can guide future research on developing countermeasures for mitigating spaceflight-associated skin damage., (© 2024. The Author(s).)

Objective: To document sleep duration and sleep quality among a sample of Marshallese adults and to examine if sleep duration and quality are associated with type 2 diabetes, body mass index (BMI), and self-reported health in the Marshallese population., Design: Cross-sectional analysis of a staff-administered survey., Setting: Thirty Marshallese churches in Arkansas and Oklahoma., Participants: The study includes 378 Marshallese participants, 56.6% female, with a mean age of 42.4 years (±11.6). Recruitment was limited to participants who were considered overweight, with a BMI >25 kg/m 2 ., Measures: Staff-administered surveys were used to collect data on sleep duration, sleep quality, and self-reported health. Clinical measures were collected by trained research personnel using standard tools and protocols. Kruskal-Wallis tests, Spearman's correlations, and nonparametric tests of trends were used to evaluate differences in HbA1c, BMIc, and self-reported health by sleep duration and quality. Multivariable analyses were used to test the associations, controlling for sociodemographic factors., Results: Fifty-four percent of the participants reported something other than normal sleep duration and 52.4% reported at least 1 night of difficult or interrupted sleep in the previous 2-week period. Longer sleep duration was associated with lower HbA1c and poorer sleep quality was associated with higher HbA1c. Poor sleep quality was associated with lower self-reported health. However, neither sleep duration nor quality was associated with BMI. The associations were found independent of sociodemographic factors., Conclusion: This is the first study to document sleep duration and sleep quality, as well as the first study to examine the relationship between sleep and HbA1c, BMI, and self-reported health in Marshallese adults with a BMI >25 kg/m 2 . This research will be used to help develop sleep interventions to address type 2 diabetes health disparities in the Marshallese community., (Copyright © 2021. Published by Elsevier Inc.)

Social networks - or the web of relationships between individuals - may influence cardiovascular disease risk, particularly in low-income urban communities that suffer from a high prevalence of cardiovascular disease. Our objective was to describe the social networks of public housing residents - a low-income urban population - in Baltimore, MD and the association between these networks and blood pressure. We used cross-sectional survey data of randomly selected heads of household in two public housing complexes in Baltimore, MD (8/2014-8/2015). Respondents answered questions about 10 social network members, including attributes of their relationship and the frequency of interaction between members. We calculated measures of network composition (e.g., proportion of network members who were family members) and network structure (e.g., density), which we then dichotomized as "high" (upper quartile) and "low" (less than upper quartile). We used linear regression to test the association between network measures and mean systolic and diastolic blood pressure. The sample included 259 respondents (response rate: 46.6%). Mean age was 44.4 years, 85.7% were women, 95.4% Black, and 56.0% had a history of hypertension. A high proportion of older children (age 8-17 years) in the network (>30%) was associated with a 4.0% (95%CI [0.07, 8.07], p = 0.047) higher mean systolic blood pressure (~4.9 mmHg greater). Other network attributes had no association with blood pressure. Social network attributes, such as having a high proportion of older children in one's network, may have particular relevance to blood pressure among low-income public housing residents, reinforcing the potential importance of social relationships to cardiovascular health., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2020 The Authors.)

A microfluidic device for conducting electrochemical enzyme immunoassays is described. The new "lab-on-a-chip" protocol integrates precolumn reactions of alkaline phosphatase-labeled antibody (anti-mouse IgG) with the antigen (mouse IgG), followed by electrophoretic separation of the free antibody and antibody-antigen complex. The separation is followed by a postcolumn reaction of the enzyme tracer with the 4-aminophenyl phosphate substrate and a downstream amperometric detection of the liberated 4-aminophenol product Factors influencing the reaction, separation, and detection processes were optimized, and the analytical performance was characterized. An applied field strength of 256 V/cm results in free antibody and antibody-antigen complex migration times of 125 and 340 s, respectively. A remarkably low detection limit of 2.5 x 10(-16) g/mL (1.7 x 10(-18) M) is obtained for the mouse IgG model analyte. Such combination of a complete integrated immunoassay, an attractive analytical performance, and the distinct miniaturization/portability advantages of electrochemical microsystems offers considerable promise for designing self-contained and disposable chips for decentralized clinical diagnostics or on-site environmental testing.

This article describes a novel 'Lab-on-a-Chip' protocol generating two electrophoretic peaks for a single analyte, based on the coupling of two different pre-column enzymatic reactions of the same substrate followed by electrophoretic separation of the reaction products. Such operation is illustrated for the measurement of glucose in connection to the corresponding glucose oxidase (GOx) and glucose dehydrogenase (GDH) reactions. The pre-column enzymatic reactions generate hydrogen peroxide and NADH species, that are separated (based on their different charges) and detected at the end-column amperometric detector. The peak current ratio can be used for confirming the peak identity, estimating the peak purity, addressing co-migrating interferences, and deviations from linearity. A driving voltage of 2000 V results in peroxide and NADH migration times of 93 and 260 s, respectively. Factors influencing the unique dual glucose response are examined and optimized. The concept can be extended to different target analytes based on the coupling of two pre-column reactions with electrophoretic separation of the reaction products.

A miniaturized analytical system for separating and detecting toxic organophosphate nerve agent compounds, based on the coupling of a micromachined capillary electrophoresis chip with a thick-film amperometric detector, is described. Factors influencing the on-chip separation and detection processes have been optimized. Using a MES buffer (20 mM, pH 5.0) running buffer, a 72-mm-long separation channel, and a separation voltage of 2000 V, baseline resolution is observed for paraoxon, methyl parathion, fenitrothion, and ethyl parathion in 140 s. Such miniaturization and speed advantages are coupled to submicromolar detection limits and good precision. Applicability to spiked river water samples is demonstrated, and the implications for on-site environmental monitoring and rapid security screening/warning are discussed.

This report describes a new "lab-on-a-chip" protocol integrating on-line precolumn biocatalytic reactions of multiple (oxidase and dehydrogenase) enzymes and substrates with effective capillary electrophoresis microseparations and amperometric detection. The operation of the new oxidase/dehydrogenase reaction/separation microchip is illustrated for the simultaneous measurement of glucose and ethanol in connection to the corresponding glucose oxidase and alcohol dehydrogenase reactions, respectively. The enzymatic reactions generate hydrogen peroxide and NADH species that are separated (on the basis of their different charges) and detected amperometrically at the end-column thick-film detector. A driving voltage of 2000 V results in peroxide and NADH migration times of 74 and 230 s, respectively. Operating the gold-coated carbon detector at +1.0 V allows simultaneous anodic detection of both reaction products. Factors influencing the reaction, separation, and detection processes are examined and optimized. The applicability of the new multienzyme assay to wine samples is illustrated.

Glass microchips, integrating chemical derivatization reactions, electrophoretic separations, and amperometric detection, have been developed. The performance of the new integrated microfabricated devices is demonstrated for rapid on-chip measurements of amino acids utilizing precolumn reactions of amino acids with o-phthaldialdehyde/2-mercaptoethanol to generate electroactive derivatives that are separated electrophoretically and detected at the end-column electrochemical detector. The influence of the sample/reagent mixing ratio, reagent concentrations, driving voltage, detection potential, and other variables is explored. The integrated microsystem offers a rapid (6 min) simultaneous measurements of eight amino acids, down to approximately 2.5 x 10(-6) M (5 fmol) level, with linearity up to the 2 x 10(-4) M level examined, and good reproducibility (RSD = 2.2-2.7%). A step of the driving voltage is used for decreasing the migration time of late-eluting components and reducing the overall analysis time. The integrated microfabricated device expands the scope of on-chip electrochemical detection to nonelectroactive analytes and holds promise of being a powerful analytical tool.

A micromachined capillary electrophoresis chip is described for simultaneous measurements of glucose, ascorbic acid, acetaminophen, and uric acid. Fluid control is used to mix the sample and enzyme glucose oxidase (GOx). The enzymatic reaction, a catalyzed aerobic oxidation of glucose to gluconic acid and hydrogen peroxide, occurs along the separation channel. The enzymatically liberated neutral peroxide species is separated electrophoretically from the anionic uric and ascorbic acids in the separation/reaction channel. The three oxidizable species are detected at the downstream gold-coated thick-film amperometric detector at different migration times. Glucose can be detected within less than 100 s, and detection of all electroactive constituents is carried out within 4 min. Measurements of glucose in the presence of acetaminophen, a neutral compound, are accomplished by comparing the responses in the presence and absence of GOx in the running buffer. The reproducibility of the on-chip glucose measurements is improved greatly by using uric acid as an internal standard. Factors influencing the performance, including the GOx concentration, field strength, and detection potential, are optimized. Such coupling of enzymatic assays with electrophoretic separations on a microchip platform holds great promise for rapid testing of metabolites (such as glucose or lactate), as well as for the introduction of high-speed clinical microanalyzers based on multichannel chips.