477 research outputs found
Effect of Impact Angle on Astrocyte Gene Expression
Over one million people each year experience some form of traumatic brain injury. Every individual’s injury is different as impacts can affect different parts of the brain in various ways. This study was conducted to test the impact angles effect on astrocytes by measuring gene expression of TNF- alpha, an inflammation marker, and GFAP, a gene released in response to reactive astrocytes, following impacts from 0, 45, and 90 degrees. Results were recorded from Polymerase Chain Reaction via the delta delta Ct method and compared to the control group for to show under-regulation or up- regulation of the genes of interest. TNF-alpha was up-regulated in the 0 degree test and under-regulated in 45, and 90. GFAP levels were increased for each angle. Two sample t-test were conducted for differences in expression levels and were found to show all significant in TNF-alpha, and significant in GFAP 45 degree impact
Vascular Health in American Football Players: Cardiovascular Risk Increased in Division III Players
Studies report that football players have high blood pressure (BP) and increased cardiovascular risk. There are over 70,000 NCAA football players and 450 Division III schools sponsor football programs, yet limited research exists on vascular health of athletes. This study aimed to compare vascular and cardiovascular health measures between football players and nonathlete controls. Twenty-three athletes and 19 nonathletes participated. Vascular health measures included flow-mediated dilation (FMD) and carotid artery intima-media thickness (IMT). Cardiovascular measures included clinic and 24 hr BP levels, body composition, VO2 max, and fasting glucose/cholesterol levels. Compared to controls, football players had a worse vascular and cardiovascular profile. Football players had thicker carotid artery IMT (0.49 ± 0.06 mm versus 0.46 ± 0.07 mm) and larger brachial artery diameter during FMD (4.3 ± 0.5 mm versus 3.7 ± 0.6 mm), but no difference in percent FMD. Systolic BP was significantly higher in football players at all measurements: resting (128.2 ± 6.4 mmHg versus 122.4 ± 6.8 mmHg), submaximal exercise (150.4 ± 18.8 mmHg versus 137.3 ± 9.5 mmHg), maximal exercise (211.3 ± 25.9 mmHg versus 191.4 ± 19.2 mmHg), and 24-hour BP (124.9 ± 6.3 mmHg versus 109.8 ± 3.7 mmHg). Football players also had higher fasting glucose (91.6 ± 6.5 mg/dL versus 86.6 ± 5.8 mg/dL), lower HDL (36.5±11.2 mg/dL versus 47.1±14.8 mg/dL), and higher body fat percentage (29.2±7.9% versus 23.2±7.0%). Division III collegiate football players remain an understudied population and may be at increased cardiovascular risk
Quality of life among adolescents with sickle cell disease: Mediation of pain by internalizing symptoms and parenting stress
<p>Abstract</p> <p>Background</p> <p>This study aimed to clarify associations between pain, psychological adjustment, and family functioning with health-related quality of life (HRQOL) in a sample of adolescents with sickle cell disease (SCD) utilizing teen- and parent-report.</p> <p>Methods</p> <p>Forty-two adolescents (between the ages of 12 and 18) with SCD and their primary caregivers completed paper-and-pencil measures of pain, teen's psychological adjustment, and HRQOL. In addition, primary caregivers completed a measure of disease-related parenting stress. Medical file review established disease severity.</p> <p>Results</p> <p>Pearson correlations identified significant inverse associations of pain frequency with physical and psychosocial domains of HRQOL as rated by the teen and primary caregiver. Generally, internalizing symptoms (i.e. anxiety and depression) and disease-related parenting stress were also significantly correlated with lower HRQOL. Examination of possible mediator models via a series of regression analyses confirmed that disease-related parenting stress served as a mediator between pain frequency and physical and psychosocial HRQOL. Less consistent were findings for mediation models involving internalizing symptoms. For these, parent-rated teen depression and teen anxiety served as mediators of the association of pain frequency and HRQOL.</p> <p>Conclusion</p> <p>Results are consistent with extant literature that suggests the association of pain and HRQOL and identify concomitant pain variables of internalizing symptoms and family variables as mediators. Efforts to improve HRQOL should aim to address internalizing symptoms associated with pain as well as parenting stress in the context of SCD management.</p
Resveratrol Effects on Astrocyte Function: Relevance to Neurodegenerative Diseases
Inflammatory molecules have been implicated in the pathogenesis of neurodegenerative diseases such as Parkinson’s disease, Alzheimer’s disease, and multiple sclerosis. Resveratrol is an antifungal compound found in the skins of red grapes and other fruits and nuts. We examined the ability of resveratrol to inhibit lipopolysaccharide (LPS)-induced production of inflammatory molecules from primary mouse astrocytes. Resveratrol inhibited LPS-induced production of nitric oxide (NO); the cytokines tumor necrosis factor-alpha (TNF-α), interleukin 1-beta (IL-1β), and IL-6; and the chemokine monocyte chemotactic protein-1 (MCP-1), which play critical roles in innate immunity, by astrocytes. Resveratrol also suppressed astrocyte production of IL-12p40 and IL-23, which are known to alter the phenotype of T cells involved in adaptive immunity. Finally resveratrol inhibited astrocyte production of C-reactive protein (CRP), which plays a role in a variety of chronic inflammatory disorders. Collectively, these studies suggest that resveratrol may be an effective therapeutic agent in neurodegenerative diseases initiated or maintained by inflammatory processes
Vitamin A and fish oils for preventing the progression of retinitis pigmentosa.
BACKGROUND: Retinitis pigmentosa (RP) comprises a group of hereditary eye diseases characterized by progressive degeneration of retinal photoreceptors. It results in severe visual loss that may lead to blindness. Symptoms may become manifest during childhood or adulthood which include poor night vision (nyctalopia) and constriction of peripheral vision (visual field loss). Visual field loss is progressive and affects central vision later in the disease course. The worldwide prevalence of RP is approximately 1 in 4000, with 100,000 individuals affected in the USA. At this time, there is no proven therapy for RP.
OBJECTIVES: The objective of this review was to synthesize the best available evidence regarding the effectiveness and safety of vitamin A and fish oils (docosahexaenoic acid (DHA)) in preventing the progression of RP.
SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (2020, Issue 2); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov; the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP); and OpenGrey. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 7 February 2020.
SELECTION CRITERIA: We included randomized controlled trials that enrolled participants of any age diagnosed with any degree of severity or type of RP, and evaluated the effectiveness of vitamin A, fish oils (DHA), or both compared to placebo, vitamins (other than vitamin A), or no therapy, as a treatment for RP. We excluded cluster-randomized trials and cross-over trials.
DATA COLLECTION AND ANALYSIS: We prespecified the following outcomes: mean change from baseline visual field, mean change from baseline electroretinogram (ERG) amplitudes, and anatomic changes as measured by optical coherence tomography (OCT), at one-year follow-up, and mean change in visual acuity, at five-year follow-up. Two review authors independently extracted data and evaluated risk of bias for all included trials. We also contacted study investigators for further information when necessary.
MAIN RESULTS: In addition to three trials from the previous version of this review, we included a total of four trials with 944 participants aged 4 to 55 years. Two trials included only participants with X-linked RP and the other two included participants with RP of all forms of genetic predisposition. Two trials evaluated the effect of DHA alone; one trial evaluated vitamin A alone; and one trial evaluated DHA and vitamin A versus vitamin A alone. Two trials recruited participants from the USA, and the other two recruited from the USA and Canada. All trials were at low risk of bias for most domains. We did not perform meta-analysis due to clinical heterogeneity. Four trials assessed visual field sensitivity. Investigators found no evidence of a difference in mean values between the groups. However, one trial found that the annual rate of change of visual field sensitivity over four years favored the DHA group in foveal (-0.02 ± 0.55 (standard error (SE)) dB versus -0.47 ± 0.03 dB, P = 0.039), macular (-0.42 ± 0.05 dB versus -0.85 ± 0.03 dB, P = 0.031), peripheral (-0.39 ± 0.02 versus -0.86 ± 0.02 dB, P \u3c 0.001), and total visual field sensitivity (-0.39 ± 0.02 versus -0.86 ± 0.02 dB, P \u3c 0.001). The certainty of the evidence was very low. The four trials evaluated visual acuity (LogMAR scale) at a follow-up of four to six years. In one trial (208 participants), investigators found no evidence of a difference between the two groups, as both groups lost 0.7 letters of the Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity per year. In another trial (41 participants), DHA showed no evidence of effect on visual acuity (mean difference -0.01 logMAR units (95% confidence interval -0.14 to 0.12; one letter difference between the two groups; very low-certainty evidence). In the third trial (60 participants), annual change in mean number of letters correct was -0.8 (DHA) and 1.4 letters (placebo), with no evidence of between-group difference. In the fourth trial (572 participants), which evaluated (vitamin A + vitamin E trace) compared with (vitamin A trace + vitamin E trace), decline in ETDRS visual acuity was 1.1 versus 0.9 letters per year, respectively. All four trials reported electroretinography (ERG). Investigators of two trials found no evidence of a difference between the DHA and placebo group in yearly rates of change in 31 Hz cone ERG amplitude (mean ± SE) (-0.028 ± 0.001 log μV versus -0.022 ± 0.002 log μV; P = 0.30); rod ERG amplitude (mean ± SE) (-0.010 ± 0.001 log μV versus -0.023 ± 0.001 log μV; P = 0.27); and maximal ERG amplitude (mean ± SE) (-0.042 ± 0.001 log μV versus -0.036 ± 0.001 log μV; P = 0.65). In another trial, a slight difference (6.1% versus 7.1%) in decline of ERG per year favored vitamin A (P = 0.01). The certainty of the evidence was very low. One trial (51 participants) that assessed optical coherence tomography found no evidence of a difference in ellipsoid zone constriction (P = 0.87) over two years, with very low-certainty evidence. The other three trials did not report this outcome. Only one trial reported adverse events, which found that 27/60 participants experienced 42 treatment-related emergent adverse events (22 in DHA group, 20 in placebo group). The certainty of evidence was very low. The rest of the trials reported no adverse events, and no study reported any evidence of benefit of vitamin supplementation on the progression of visual acuity loss.
AUTHORS\u27 CONCLUSIONS: Based on the results of four studies, it is uncertain if there is a benefit of treatment with vitamin A or DHA, or both for people with RP. Future trials should also take into account the changes observed in ERG amplitudes and other outcome measures from trials included in this review
Taking aim on empowerment research: On the distinction between individual and psychological conceptions
Empowerment theory need not remain a mystery. Efforts, such as those described in this special section, to outline more clearly the nomological network of empowerment at multiple levels of analysis will advance empowerment theory. Tough-minded rigorous research is needed to advance the concept of empowerment. Empowerment research requires us to shift our attention from a debate between the merits of research at one level of analysis versus another to building bridges between levels of analysis. We must integrate theories and methods from other disciplines and develop research strategies that incorporate qualitative procedures and the voices of the research participants. The papers in this special section take aim on these tasks and add to our understanding of empowerment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44024/1/10464_2004_Article_BF00922695.pd
Reelin Secreted by GABAergic Neurons Regulates Glutamate Receptor Homeostasis
BACKGROUND: Reelin is a large secreted protein of the extracellular matrix that has been proposed to participate to the etiology of schizophrenia. During development, reelin is crucial for the correct cytoarchitecture of laminated brain structures and is produced by a subset of neurons named Cajal-Retzius. After birth, most of these cells degenerate and reelin expression persists in postnatal and adult brain. The phenotype of neurons that bind secreted reelin and whether the continuous secretion of reelin is required for physiological functions at postnatal stages remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: Combining immunocytochemical and pharmacological approaches, we first report that two distinct patterns of reelin expression are present in cultured hippocampal neurons. We show that in hippocampal cultures, reelin is secreted by GABAergic neurons displaying an intense reelin immunoreactivity (IR). We demonstrate that secreted reelin binds to receptors of the lipoprotein family on neurons with a punctate reelin IR. Secondly, using calcium imaging techniques, we examined the physiological consequences of reelin secretion blockade. Blocking protein secretion rapidly and reversibly changes the subunit composition of N-methyl-D-aspartate glutamate receptors (NMDARs) to a predominance of NR2B-containing NMDARs. Addition of recombinant or endogenously secreted reelin rescues the effects of protein secretion blockade and reverts the fraction of NR2B-containing NMDARs to control levels. Therefore, the continuous secretion of reelin is necessary to control the subunit composition of NMDARs in hippocampal neurons. CONCLUSIONS/SIGNIFICANCE: Our data show that the heterogeneity of reelin immunoreactivity correlates with distinct functional populations: neurons synthesizing and secreting reelin and/or neurons binding reelin. Furthermore, we show that continuous reelin secretion is a strict requirement to maintain the composition of NMDARs. We propose that reelin is a trans-neuronal messenger secreted by GABAergic neurons that regulates NMDARs homeostasis in postnatal hippocampus. Defects in reelin secretion could play a major role in the development of neuropsychiatric disorders, particularly those associated with deregulation of NMDARs such as schizophrenia
Mentoring Underrepresented Minority Physician-Scientists to Success
As the nation seeks to recruit and retain physician-scientists, gaps remain in understanding and addressing mitigatable challenges to the success of faculty from underrepresented minority (URM) backgrounds. The Doris Duke Charitable Foundation Fund to Retain Clinical Scientists program, implemented in 2015 at 10 academic medical centers in the United States, seeks to retain physician-scientists at risk of leaving science because of periods of extraordinary family caregiving needs, hardships that URM faculty-especially those who identify as female-are more likely to experience. At the annual Fund to Retain Clinical Scientists program directors conference in 2018, program directors-21% of whom identify as URM individuals and 13% as male-addressed issues that affect URM physician-scientists in particular. Key issues that threaten the retention of URM physician-scientists were identified through focused literature reviews; institutional environmental scans; and structured small- and large-group discussions with program directors, staff, and participants. These issues include bias and discrimination, personal wealth differential, the minority tax (i.e., service burdens placed on URM faculty who represent URM perspectives on committees and at conferences), lack of mentorship training, intersectionality and isolation, concerns about confirming stereotypes, and institutional-level factors. The authors present recommendations for how to create an environment in which URM physician-scientists can expect equitable opportunities to thrive, as institutions demonstrate proactive allyship and remove structural barriers to success. Recommendations include providing universal training to reduce interpersonal bias and discrimination, addressing the consequences of the personal wealth gap through financial counseling and benefits, measuring the service faculty members provide to the institution as advocates for URM faculty issues and compensating them appropriately, supporting URM faculty who wish to engage in national leadership programs, and sustaining institutional policies that address structural and interpersonal barriers to inclusive excellence
Effects of Dietary and Plasma Lipid Levels on Vascular Health Measures
Please refer to the pdf version of the abstract located adjacent to the title
Corticosteroid suppression of lipoxin A4 and leukotriene B4from alveolar macrophages in severe asthma
<p>Abstract</p> <p>Background</p> <p>An imbalance in the generation of pro-inflammatory leukotrienes, and counter-regulatory lipoxins is present in severe asthma. We measured leukotriene B<sub>4 </sub>(LTB<sub>4</sub>), and lipoxin A<sub>4 </sub>(LXA<sub>4</sub>) production by alveolar macrophages (AMs) and studied the impact of corticosteroids.</p> <p>Methods</p> <p>AMs obtained by fiberoptic bronchoscopy from 14 non-asthmatics, 12 non-severe and 11 severe asthmatics were stimulated with lipopolysaccharide (LPS,10 μg/ml) with or without dexamethasone (10<sup>-6</sup>M). LTB<sub>4 </sub>and LXA<sub>4 </sub>were measured by enzyme immunoassay.</p> <p>Results</p> <p>LXA<sub>4 </sub>biosynthesis was decreased from severe asthma AMs compared to non-severe (p < 0.05) and normal subjects (p < 0.001). LXA<sub>4 </sub>induced by LPS was highest in normal subjects and lowest in severe asthmatics (p < 0.01). Basal levels of LTB<sub>4 </sub>were decreased in severe asthmatics compared to normal subjects (p < 0.05), but not to non-severe asthma. LPS-induced LTB<sub>4 </sub>was increased in severe asthma compared to non-severe asthma (p < 0.05). Dexamethasone inhibited LPS-induced LTB<sub>4 </sub>and LXA<sub>4</sub>, with lesser suppression of LTB<sub>4 </sub>in severe asthma patients (p < 0.05). There was a significant correlation between LPS-induced LXA<sub>4 </sub>and FEV<sub>1 </sub>(% predicted) (r<sub>s </sub>= 0.60; p < 0.01).</p> <p>Conclusions</p> <p>Decreased LXA<sub>4 </sub>and increased LTB<sub>4 </sub>generation plus impaired corticosteroid sensitivity of LPS-induced LTB<sub>4 </sub>but not of LXA<sub>4 </sub>support a role for AMs in establishing a pro-inflammatory balance in severe asthma.</p
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