145 research outputs found

    Selective reduction in the expression of type-1 metabotropic glutamate receptors in the hippocampus of adult rats born by caesarean section

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    Perinatal hypoxia causes long-term neurobiological consequences, including alterations in mechanisms of activity-dependent synaptic plasticity and cognitive dysfunction. Changes in neurotransmitter receptors have been associated with these alterations, but little is known on how early hypoxia influences the expression and function of metabotropic glutamate (mGlu) receptors in adult life. This is an important issue because mGlu receptors are implicated in mechanisms of synaptic plasticity. Here, we examined the expression of mGlu1, mGlu5, and mGlu2/3 receptor subtypes in the hippocampus, nucleus accumbens, prefrontal cortex, and dorsal striatum in 6-month old Wistar rats (a) born by vaginal delivery; (b) born by caesarean section; and (c) born by caesarean section followed by 20 min of asphyxia. Unexpectedly, we found a large reduction of mGlu1Ξ± protein levels in the hippocampus of rats born by caesarean section regardless of the presence of asphyxia. No changes in mGlu1Ξ± receptor protein levels were found in the other brain regions. Levels of mGlu5 and mGlu2/3 receptors and levels of GluA2/3 and GluN1 subunits of AMPA and NMDA receptors did not differ among the three groups of rats in any brain region. These results are consistent with previous findings showing that changes in mGlu1 receptors occur within the epigenetic programming caused by early-life events

    Social Networks as Predictors of Colorectal Cancer Screening in African Americans

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    Background: Early detection can reduce colorectal cancer (CRC) mortality by 15%–33%, and screening is widely recommended for average-risk adults beginning at age 50 years. Colorectal cancer mortality rates are higher in African Americans than in whites, while screening rates are somewhat lower. Individual social networks can reduce emotional and/or logistical barriers to healthpromoting but distasteful procedures such as CRC screening. The aim of this study was to examine social network interactions, and their impact on CRC screening among African Americans. We hypothesized a positive association between social network index (SNI) scores and CRC screening. Methods: In a community intervention trial with four arms, we previously demonstrated the efficacy of a small group educational intervention to promote CRC screening among African Americans. This intervention outperformed a one-on-one educational intervention, a reduced out-of-pocket expense intervention, and a control condition. In the present analysis, we compared the SNI scores for participants in the small group intervention cohort with a comparison group comprised of the other three cohorts. Social networks were assessed using the Social Network Index developed by Cohen. Results: Small group participants had a significantly higher network diversity score (Mean difference 0.71; 95% CI, 0.12-1.31; p=0.0017) than the comparison group. In the second component of the SNI score - -the number of people talked to over a two week period -- the small group intervention cohort also scored significantly higher than the comparison group. (Mean difference, 9.29; 95% CI, 3.963-14.6266; p=0.0004). Conclusions: The findings suggest that social interaction and support was at least partially responsible for the relatively high post-intervention screening rate in the small group intervention participants. Education in small groups could foster strong social networks. Strong and positive network diversity and a large number of people in social networks may enhance CRC screening rates among African Americans

    Formative Research to Develop a Lifestyle Application (App) for African American Breast Cancer Survivors

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    Background: There is a proliferation of lifestyle-oriented mobile technologies; however, few have targeted users. Through intervention mapping, investigators and community partners completed Steps 1-3 (needs assessment, formulation of change objectives, and selection of theory-based methods) of a process to develop a mobile cancer prevention application (app) for cancer prevention. The aim of this qualitative study was to complete Step 4 (intervention development) by eliciting input from African American (AA) breast cancer survivors (BCSs) to guide app development. Methods: Four focus group discussions (n=60) and three individual semi-structured interviews (n=36) were conducted with AA BCSs (40-72 years of age) to assess barriers and strategies for lifestyle change. All focus groups and interviews were recorded and transcribed verbatim. Data were analyzed with NVivo qualitative data analysis software version 10, allowing categories, themes, and patterns to emerge. Results: Three categories and related themes emerged from the analysis: 1) perceptions about modifiable risk factors; 2) strategies related to adherence to cancer prevention guidelines; and 3) app components to address barriers to adherence. Participant perceptions, strategies, and recommended components guided development of the app. Conclusions: For development of a mobile cancer prevention app, these findings will assist investigators in targeting features thatare usable, acceptable, and accessible for AA BCSs

    Monocrystalline Si/Ξ²\beta-Ga2_2O3_3 p-n heterojunction diodes fabricated via grafting

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    The Ξ²\beta-Ga2_2O3_3 has exceptional electronic properties with vast potential in power and RF electronics. Despite the excellent demonstrations of high-performance unipolar devices, the lack of p-type doping in Ξ²\beta-Ga2_2O3_3 has hindered the development of Ga2_2O3_3-based bipolar devices. The approach of p-n diodes formed by polycrystalline p-type oxides with n-type Ξ²\beta-Ga2_2O3_3 can face severe challenges in further advancing the Ξ²\beta-Ga2_2O3_3 bipolar devices due to their unfavorable band alignment and the poor p-type oxide crystal quality. In this work, we applied the semiconductor grafting approach to fabricate monocrystalline Si/Ξ²\beta-Ga2_2O3_3 p-n diodes for the first time. With enhanced concentration of oxygen atoms at the interface of Si/Ξ²\beta-Ga2_2O3_3, double side surface passivation was achieved for both Si and Ξ²\beta-Ga2_2O3_3 with an interface Dit value of 1-3 x 1012 /cm2 eV. A Si/Ξ²\beta-Ga2_2O3_3 p-n diode array with high fabrication yield was demonstrated along with a diode rectification of 1.3 x 107 at +/- 2 V, a diode ideality factor of 1.13 and avalanche reverse breakdown characteristics. The diodes C-V shows frequency dispersion-free characteristics from 10 kHz to 2 MHz. Our work has set the foundation toward future development of Ξ²\beta-Ga2_2O3_3-based transistors.Comment: 32 pages, 10 figures. The preliminary data were presented as a poster in the 5th US Gallium Oxide Workshop, Washington, DC. August 07-10, 202

    Trends in upper gastrointestinal diagnosis over four decades in Lusaka, Zambia: a retrospective analysis of endoscopic findings

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    BACKGROUND AND AIMS: There a shortage of robust information about profiles of gastrointestinal disease in sub-Saharan Africa. The endoscopy unit of the University Teaching Hospital in Lusaka has been running without interruption since 1977 and this 38-year record is largely intact. We report an analysis of endoscopic findings over this period. METHODS: Written endoscopy records from 29th September 1977 to 16th December 2014 were recovered, computerised, coded by two experienced endoscopists and analysed. Temporal trends were analysed using tables, graphs, and unconditional logistic regression, with age, sex of patient, decade, and endoscopist as independent variables to adjust for inter-observer variation. RESULTS: Sixteen thousand nine hundred fifty-three records were identified and analysed. Diagnosis of gastric ulcer rose by 22Β %, and that of duodenal ulcer fell by 14Β % per decade. Endoscopically diagnosed oesophageal cancer increased by 32Β % per decade, but gastric cancer rose only in patients under 60Β years of age (21Β % per decade). Oesophageal varices were the commonest finding in patients presenting with haematemesis, increasing by 14Β % per decade in that patient group. Two HIV-related diagnoses, oesophageal candidiasis and Kaposi’s sarcoma, rose from almost zero to very high levels in the 1990s but fell substantially after 2005 when anti-retroviral therapy became widely available. CONCLUSIONS: This useful dataset suggests that there are important trends in some endoscopic findings over four decades. These trends are not explained by inter-observer variation. Reasons for the divergent trends in incidence of peptic ulceration and apparent trends in diagnosis of upper gastrointestinal cancers merit further exploration

    Inhibition of Src kinase activity attenuates amyloid associated microgliosis in a murine model of Alzheimer’s disease

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    <p>Abstract</p> <p>Background</p> <p>Microglial activation is an important histologic characteristic of the pathology of Alzheimer’s disease (AD). One hypothesis is that amyloid beta (AΞ²) peptide serves as a specific stimulus for tyrosine kinase-based microglial activation leading to pro-inflammatory changes that contribute to disease. Therefore, inhibiting AΞ² stimulation of microglia may prove to be an important therapeutic strategy for AD.</p> <p>Methods</p> <p>Primary murine microglia cultures and the murine microglia cell line, BV2, were used for stimulation with fibrillar AΞ²1-42. The non-receptor tyrosine kinase inhibitor, dasatinib, was used to treat the cells to determine whether Src family kinase activity was required for the AΞ² stimulated signaling response and subsequent increase in TNFΞ± secretion using Western blot analysis and enzyme-linked immunosorbent assay (ELISA), respectively. A histologic longitudinal analysis was performed using an AD transgenic mouse model, APP/PS1, to determine an age at which microglial protein tyrosine kinase levels increased in order to administer dasatinib via mini osmotic pump diffusion. Effects of dasatinib administration on microglial and astroglial activation, protein phosphotyrosine levels, active Src kinase levels, AΞ² plaque deposition, and spatial working memory were assessed via immunohistochemistry, Western blot, and T maze analysis.</p> <p>Results</p> <p>AΞ² fibrils stimulated primary murine microglia via a tyrosine kinase pathway involving Src kinase that was attenuated by dasatinib. Dasatinib administration to APP/PS1 mice decreased protein phosphotyrosine, active Src, reactive microglia, and TNFΞ± levels in the hippocampus and temporal cortex. The drug had no effect on GFAP levels, AΞ² plaque load, or the related tyrosine kinase, Lyn. These anti-inflammatory changes correlated with improved performance on the T maze test in dasatinib infused animals compared to control animals.</p> <p>Conclusions</p> <p>These data suggest that amyloid dependent microgliosis may be Src kinase dependent <it>in vitro</it> and <it>in vivo.</it> This study defines a role for Src kinase in the microgliosis characteristic of diseased brains and suggests that particular tyrosine kinase inhibition may be a valid anti-inflammatory approach to disease. Dasatinib is an FDA-approved drug for treating chronic myeloid leukemia cancer with a reported ability to cross the blood-brain barrier. Therefore, this suggests a novel use for this drug as well as similar acting molecules.</p

    Estimating global injuries morbidity and mortality: methods and data used in the Global Burden of Disease 2017 study

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    BACKGROUND: While there is a long history of measuring death and disability from injuries, modern research methods must account for the wide spectrum of disability that can occur in an injury, and must provide estimates with sufficient demographic, geographical and temporal detail to be useful for policy makers. The Global Burden of Disease (GBD) 2017 study used methods to provide highly detailed estimates of global injury burden that meet these criteria. METHODS: In this study, we report and discuss the methods used in GBD 2017 for injury morbidity and mortality burden estimation. In summary, these methods included estimating cause-specific mortality for every cause of injury, and then estimating incidence for every cause of injury. Non-fatal disability for each cause is then calculated based on the probabilities of suffering from different types of bodily injury experienced. RESULTS: GBD 2017 produced morbidity and mortality estimates for 38 causes of injury. Estimates were produced in terms of incidence, prevalence, years lived with disability, cause-specific mortality, years of life lost and disability-adjusted life-years for a 28-year period for 22 age groups, 195 countries and both sexes. CONCLUSIONS: GBD 2017 demonstrated a complex and sophisticated series of analytical steps using the largest known database of morbidity and mortality data on injuries. GBD 2017 results should be used to help inform injury prevention policy making and resource allocation. We also identify important avenues for improving injury burden estimation in the future

    Global burden of 369 diseases and injuries in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

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    The desmosome and pemphigus

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    Desmosomes are patch-like intercellular adhering junctions (β€œmaculae adherentes”), which, in concert with the related adherens junctions, provide the mechanical strength to intercellular adhesion. Therefore, it is not surprising that desmosomes are abundant in tissues subjected to significant mechanical stress such as stratified epithelia and myocardium. Desmosomal adhesion is based on the Ca2+-dependent, homo- and heterophilic transinteraction of cadherin-type adhesion molecules. Desmosomal cadherins are anchored to the intermediate filament cytoskeleton by adaptor proteins of the armadillo and plakin families. Desmosomes are dynamic structures subjected to regulation and are therefore targets of signalling pathways, which control their molecular composition and adhesive properties. Moreover, evidence is emerging that desmosomal components themselves take part in outside-in signalling under physiologic and pathologic conditions. Disturbed desmosomal adhesion contributes to the pathogenesis of a number of diseases such as pemphigus, which is caused by autoantibodies against desmosomal cadherins. Beside pemphigus, desmosome-associated diseases are caused by other mechanisms such as genetic defects or bacterial toxins. Because most of these diseases affect the skin, desmosomes are interesting not only for cell biologists who are inspired by their complex structure and molecular composition, but also for clinical physicians who are confronted with patients suffering from severe blistering skin diseases such as pemphigus. To develop disease-specific therapeutic approaches, more insights into the molecular composition and regulation of desmosomes are required
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