276 research outputs found
Marguerite Harrison and Hannah Arendt: The Notion of \u3cem\u3eStrength\u3c/em\u3e within the Early Totalitarian Soviet Prison Experience
Racial Disparities in Caesarean Delivery Among Nulliparous Women that Delivered at Term: Cross-Sectional Decomposition Analysis of Nebraska Birth Records
Background: Access to medically indicated caesarean sections is an essential strategy for reducing maternal and infant mortality rates worldwide. However, overuse of medically unnecessary caesarean sections is associated with excess maternal-child morbidity. Previous studies suggest higher rates of caesarean section among women who identify as racial/ethnic minorities.
Significance of Problem: Despite national efforts to prioritize the reduction of medically unnecessary caesarean sections, caesareans rates in the United States have remained stable over the last decade. Women who identify as racial or ethnic minorities experience disproportionally higher rates of caesarean, even when controlling for demographic, behavioral, medical, and institutional level factors. However, detailed analysis of factors contributing to racial/ethnic disparities in caesarean section rates remains largely unexplored. Identifying these factors and assessing their relative importance is critical for the development of interventions specifically tailored to reduce racial and ethnic disparities in caesarean use.
Question: The objective of this study was to understand underlying social and demographic factors that contribute to differences in caesarean rates across racial and ethnic groups.
Experimental Design: Data was collected from 2005-2014 Nebraska birth records on singleton births occurring on or after 37 weeks gestation (n=87,908). Risk ratios (RR) and 95% confidence intervals (CI) for caesarean were calculated for different racial and ethnic categories. Fairlie decomposition technique was utilized to quantify the contribution of individual variables to the observed differences in caesarean.
Results: In the adjusted analysis, relative to non-Hispanic (NH) White race, both Asian-NH (RR 1.21, 95% CI 1.14, 1.28) and Black-NH races (RR 1.13, 95% CI 1.08, 1.19) were associated with a significantly higher risk for caesarean. The decomposition analysis showed that among the variables assessed, maternal age, education, and pre-pregnancy BMI contributed the most to the observed differences in caesarean rates across racial/ethnic groups.
Conclusion: This analysis quantified the effect of social and demographic factors on racial differences in caesarean delivery, which may guide public health interventions aimed towards reducing racial disparities in caesarean rates. Interventions targeted towards modifying maternal characteristics, such as reducing pre-pregnancy BMI or increasing maternal education, may narrow the gap in caesarean rates across racial and ethnic groups. Future studies should determine the contribution of physician characteristics, hospital characteristics, and structural determinants of health towards racial disparities in caesarean rates.https://digitalcommons.unmc.edu/chri_forum/1064/thumbnail.jp
Assessing Lumbar Plexus and Sciatic Nerve Damage in Relapsing-Remitting Multiple Sclerosis Using Magnetisation Transfer Ratio
Neurografia de ressonància magnètica (MRN); Relació de transferència de magnetització (MTR); Esclerosi múltiple del sistema nerviós perifèric (SNP)Neurografía de resonancia magnética (MRN); Relación de transferencia de magnetización (MTR); Esclerosis múltiple del sistema nervioso periférico (SNP)Magnetic resonance neurography (MRN); Magnetisation transfer ratio (MTR); Multiple sclerosis peripheral nervous system (PNS)Background: Multiple sclerosis (MS) has traditionally been regarded as a disease confined to the central nervous system (CNS). However, neuropathological, electrophysiological, and imaging studies have demonstrated that the peripheral nervous system (PNS) is also involved, with demyelination and, to a lesser extent, axonal degeneration representing the main pathophysiological mechanisms.
Aim: The purpose of this study was to assess PNS damage at the lumbar plexus and sciatic nerve anatomical locations in people with relapsing-remitting MS (RRMS) and healthy controls (HCs) in vivo using magnetisation transfer ratio (MTR), which is a known imaging biomarker sensitive to alterations in myelin content in neural tissue, and not previously explored in the context of PNS damage in MS.
Method: Eleven HCs (7 female, mean age 33.6 years, range 24-50) and 15 people with RRMS (12 female, mean age 38.5 years, range 30-56) were recruited for this study and underwent magnetic resonance imaging (MRI) investigations together with clinical assessments using the expanded disability status scale (EDSS). Magnetic resonance neurography (MRN) was first used for visualisation and identification of the lumbar plexus and the sciatic nerve and MTR imaging was subsequently performed using identical scan geometry to MRN, enabling straightforward co-registration of all data to obtain global and regional mean MTR measurements. Linear regression models were used to identify differences in MTR values between HCs and people with RRMS and to identify an association between MTR measures and EDSS.
Results: MTR values in the sciatic nerve of people with RRMS were found to be significantly lower compared to HCs, but no significant MTR changes were identified in the lumbar plexus of people with RRMS. The median EDSS in people with RRMS was 2.0 (range, 0-3). No relationship between the MTR measures in the PNS and EDSS were identified at any of the anatomical locations studied in this cohort of people with RRMS.
Conclusion: The results from this study demonstrate the presence of PNS damage in people with RRMS and support the notion that these changes, suggestive of demyelination, maybe occurring independently at different anatomical locations within the PNS. Further investigations to confirm these findings and to clarify the pathophysiological basis of these alterations are warranted.The UK MS Society and the UCL-UCLH Biomedical Research Centre for ongoing support. CGW-K receives funding from the MS Society (#77), Wings for Life (#169111), BRC (#BRC704/CAP/CGW), UCL Global Challenges Research Fund (GCRF), MRC (#MR/S026088/1), Ataxia UK. FP had a non-clinical Postdoctoral Guarantors of Brain fellowship (2017-2020). FP was supported by the National Institute for Health Research, UCL Hospitals Biomedical Research Centre. CT is being funded by a Junior Leader La Caixa Fellowship (fellowship code is LCF/BQ/PI20/11760008), awarded by la Caixa Foundation (ID 100010434). She has also received the 2021 Merck's Award for the Investigation in MS, awarded by Fundación Merck Salud (Spain). In 2015, she received an ECTRIMS Post-doctoral Research Fellowship and has received funding from the UK MS Society. She has also received honoraria from Roche and Novartis, and is a steering committee member of the O'HAND trial and of the Consensus group on Follow-on DMTs. This project has received funding under the European Union's Horizon 2020 research and innovation programme under grant agreement No. 634541 and from the Engineering and Physical Sciences Research Council (EPSRC EP/R006032/1), funding FG. FG was currently supported by PREdICT, a study at the Vall d'Hebron Institute of Oncology in Barcelona funded by AstraZeneca
Comparative Analysis of Blind Detectors in a Cluster-Based Cooperative Spectrum Hole Detection
Prevention of authorized users from interference determine the accurate detection of Spectrum Hole (SH) is of great importance in a Spectrum Shearing Network (SSN). However, multipath fading and shadowing affect the accurate detection of SH resulting in interference. Cluster-Based Cooperative Spectrum Hole Detection (CBCSHD) used to address this problem depends on detector and number of clusters. Hence, comparative analysis of blind detectors in CBCSHD is carried out to evaluate its performance with various blind detectors and number of clusters. The CBCSHD is carried out using six Cognitive Users (CUs) that jointly carry out detection of SH and each of the CUs performs local sensing using Eigenvalue Detector (EVD), Energy Detector (ED) and Cyclostationary Detector (CD). The CUs form clusters to reduce reporting overhead between CUs. The local sensing results from individual user are combined at the Cluster Head (CH) using majority fusion rule. The performance of each of the detectors in CBCSHD is evaluated using Probability of Detection (PD) and Sensing Time (ST). PD values of 0.7661, 0.7160 and 0.6229 are obtained at SNR of 4 dB for ED, CD and EVD, respectively, while ST values of 3.0707, 3.7163 and 4.0907 s are obtained for ED, CD and EVD, respectively. The results obtained show that ED has the highest detection rate, followed by CD, while EVD shows the worst detection rate
Genetic influences on disease course and severity, 30 years after a clinically isolated syndrome
Genetics; Multiple sclerosis; PhenotypeGenética; Esclerosis múltiple; FenotipoGenètica; Esclerosi múltiple; FenotipMultiple sclerosis risk has a well-established polygenic component, yet the genetic contribution to disease course and severity remains unclear and difficult to examine. Accurately measuring disease progression requires long-term study of clinical and radiological outcomes with sufficient follow-up duration to confidently confirm disability accrual and multiple sclerosis phenotypes. In this retrospective study, we explore genetic influences on long-term disease course and severity; in a unique cohort of clinically isolated syndrome patients with homogenous 30-year disease duration, deep clinical phenotyping and advanced MRI metrics. Sixty-one clinically isolated syndrome patients [41 female (67%): 20 male (33%)] underwent clinical and MRI assessment at baseline, 1-, 5-, 10-, 14-, 20- and 30-year follow-up (mean age ± standard deviation: 60.9 ± 6.5 years). After 30 years, 29 patients developed relapsing-remitting multiple sclerosis, 15 developed secondary progressive multiple sclerosis and 17 still had a clinically isolated syndrome. Twenty-seven genes were investigated for associations with clinical outcomes [including disease course and Expanded Disability Status Scale (EDSS)] and brain MRI (including white matter lesions, cortical lesions, and brain tissue volumes) at the 30-year follow-up. Genetic associations with changes in EDSS, relapses, white matter lesions and brain atrophy (third ventricular and medullary measurements) over 30 years were assessed using mixed-effects models. HLA-DRB1*1501-positive (n = 26) patients showed faster white matter lesion accrual [+1.96 lesions/year (0.64–3.29), P = 3.8 × 10−3], greater 30-year white matter lesion volumes [+11.60 ml, (5.49–18.29), P = 1.27 × 10−3] and higher annualized relapse rates [+0.06 relapses/year (0.005–0.11), P = 0.031] compared with HLA-DRB1*1501-negative patients (n = 35). PVRL2-positive patients (n = 41) had more cortical lesions (+0.83 [0.08–1.66], P = 0.042), faster EDSS worsening [+0.06 points/year (0.02–0.11), P = 0.010], greater 30-year EDSS [+1.72 (0.49–2.93), P = 0.013; multiple sclerosis cases: +2.60 (1.30–3.87), P = 2.02 × 10−3], and greater risk of secondary progressive multiple sclerosis [odds ratio (OR) = 12.25 (1.15–23.10), P = 0.031] than PVRL2-negative patients (n = 18). In contrast, IRX1-positive (n = 30) patients had preserved 30-year grey matter fraction [+0.76% (0.28–1.29), P = 8.4 × 10−3], lower risk of cortical lesions [OR = 0.22 (0.05–0.99), P = 0.049] and lower 30-year EDSS [−1.35 (−0.87,−3.44), P = 0.026; multiple sclerosis cases: −2.12 (−0.87, −3.44), P = 5.02 × 10−3] than IRX1-negative patients (n = 30). In multiple sclerosis cases, IRX1-positive patients also had slower EDSS worsening [−0.07 points/year (−0.01,−0.13), P = 0.015] and lower risk of secondary progressive multiple sclerosis [OR = 0.19 (0.04–0.92), P = 0.042]. These exploratory findings support diverse genetic influences on pathological mechanisms associated with multiple sclerosis disease course. HLA-DRB1*1501 influenced white matter inflammation and relapses, while IRX1 (protective) and PVRL2 (adverse) were associated with grey matter pathology (cortical lesions and atrophy), long-term disability worsening and the risk of developing secondary progressive multiple sclerosis.This study was funded by the Multiple Sclerosis Society of Great Britain and Northern Ireland (20; 984) and supported by the National Institute for Health and Care Research University College London Hospitals (UCLH) Biomedical Research Centre. Funding for extended SNP analysis was supported by a Small Acorns Fund from The National Brain Appeal (NBA/QSQ/SAF/R17)
The Systematic Review of Social Media Addiction and Mental Health of Nigerian University Students: The Good, The Bad and The Ugly
The global increase in popularity and accessibility to social media platforms daily, University students in Nigeria, like their counterparts worldwide, are facing unique challenges related to their mental well-being caused by media addiction despite the fact that technology has drastically and dramatically transformed the clinical delivery of mental health services globally in the recent times. However, the relationship between this transformation- social media and the mental health among the University students in Nigeria cannot be overemphasized. Therefore, this paper systematically reviewed the social media addiction and the mental health of the Nigerian University students. It further reviewed and emphasized the good aspect of social media on mental health, the negative effects it has, and the addiction (ugly) developed in the course of using social media. Studies were reviewed to juxtapose the good, bad and the ugly of the use and its influence on mental health of Nigerian students. The paper concluded that, though, social media has contributed significantly to the modern dissemination of clinical delivery but its addiction, could negatively affect the mental health of the students as many studies have established. Therefore, there is a need for a balanced approach to social media usage for this population to have and sustain better mental health because the less they are addicted to social media the better the mental health of the Nigerian students. 
The DNA-damage signature in Saccharomyces cerevisiae is associated with single-strand breaks in DNA
BACKGROUND: Upon exposure to agents that damage DNA, Saccharomyces cerevisiae undergo widespread reprogramming of gene expression. Such a vast response may be due not only to damage to DNA but also damage to proteins, RNA, and lipids. Here the transcriptional response of S. cerevisiae specifically induced by DNA damage was discerned by exposing S. cerevisiae to a panel of three "radiomimetic" enediyne antibiotics (calicheamicin γ(1)(I), esperamicin A1 and neocarzinostatin) that bind specifically to DNA and generate varying proportions of single- and double-strand DNA breaks. The genome-wide responses were compared to those induced by the non-selective oxidant γ-radiation. RESULTS: Given well-controlled exposures that resulted in similar and minimal cell death (~20–25%) across all conditions, the extent of gene expression modulation was markedly different depending on treatment with the enediynes or γ-radiation. Exposure to γ-radiation resulted in more extensive transcriptional changes classified both by the number of genes modulated and the magnitude of change. Common biological responses were identified between the enediynes and γ-radiation, with the induction of DNA repair and stress response genes, and the repression of ribosomal biogenesis genes. Despite these common responses, a fraction of the response induced by gamma radiation was repressed by the enediynes and vise versa, suggesting that the enediyne response is not entirely "radiomimetic." Regression analysis identified 55 transcripts with gene expression induction associated both with double- or single-strand break formation. The S. cerevisiae "DNA damage signature" genes as defined by Gasch et al. [1] were enriched among regulated transcripts associated with single-strand breaks, while genes involved in cell cycle regulation were associated with double-strand breaks. CONCLUSION: Dissection of the transcriptional response in yeast that is specifically signaled by DNA strand breaks has identified that single-strand breaks provide the signal for activation of transcripts encoding proteins involved in the DNA damage signature in S. cerevisiae, and double-strand breaks signal changes in cell cycle regulation genes
Quantitative Magnetization Transfer in In Vivo Healthy Human Skeletal Muscle at 3 T
The value of quantitative MR methods as potential biomarkers in neuromuscular disease is being increasingly recognized. Previous studies of the magnetization transfer ratio have demonstrated sensitivity to muscle disease. The aim of this work was to investigate quantitative magnetization transfer imaging of skeletal muscle in healthy subjects at 3 T to evaluate its potential use in pathological muscle. The lower limb of 10 subjects was imaged using a 3D fast low-angle shot acquisition with variable magnetization transfer saturation pulse frequencies and amplitudes. The data were analyzed with an established quantitative two-pool model of magnetization transfer. T1 and B1 amplitude of excitation radiofrequency field maps were acquired and used as inputs to the quantitative magnetization transfer model, allowing properties of the free and restricted proton pools in muscle to be evaluated in seven different muscles in a region of interest analysis. The average restricted pool T2 relaxation time was found to be 5.9 ± 0.2μs in the soleus muscle and the restricted proton pool fraction was 8 ± 1%. Quantitative magnetization transfer imaging of muscle offers potential new biomarkers in muscle disease within a clinically feasible scan time. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc
The Antiproliferative and Apoptotic Effects of Apigenin on Glioblastoma Cells
OBJECTIVES: Glioblastoma (GBM) is highly proliferative, infiltrative, malignant and the most deadly form of brain tumour. The epidermal growth factor receptor (EGFR) is overexpressed, amplified and mutated in GBM and has been shown to play key and important roles in the proliferation, growth and survival of this tumour. The goal of our study was to investigate the antiproliferative, apoptotic and molecular effects of apigenin in GBM.
METHODS: Proliferation and viability tests were carried out using the trypan blue exclusion, MTT and lactate dehydrogenase (LDH) assays. Flow cytometry was used to examine the effects of apigenin on the cell cycle check-points. In addition, we determined the effects of apigenin on EGFR-mediated signalling pathways by Western blot analyses.
KEY FINDINGS: Our results showed that apigenin reduced cell viability and proliferation in a dose- and time-dependent manner while increasing cytotoxicity in GBM cells. Treatment with apigenin-induced is poly ADP-ribose polymerase (PARP) cleavage and caused cell cycle arrest at the G2M checkpoint. Furthermore, our data revealed that apigenin inhibited EGFR-mediated phosphorylation of mitogen-activated protein kinase (MAPK), AKT and mammalian target of rapamycin (mTOR) signalling pathways and attenuated the expression of Bcl-xL.
CONCLUSION: Our results demonstrated that apigenin has potent inhibitory effects on pathways involved in GBM proliferation and survival and could potentially be used as a therapeutic agent for GBM
Magnetization transfer ratio measures in normal-appearing white matter show periventricular gradient abnormalities in multiple sclerosis
In multiple sclerosis, grey matter pathology occurs mostly next to or near the outer surface of the brain. Using quantitative MRI, Liu et al. reveal that white matter abnormalities are also greatest near the surface of the brain, suggesting common elements in the genesis of grey and white matter patholog
- …