1,792 research outputs found
Preferential Myosin Heavy Chain Isoform B Expression May Contribute to the Faster Velocity of Contraction in Veins versus Arteries
Smooth muscle myosin heavy chains occur in 2 isoforms, SMA (slow) and SMB (fast). We hypothesized that the SMB isoform is predominant in the faster-contracting rat vena cava compared to thoracic aorta. We compared the time to half maximal contraction in response to a maximal concentration of endothelin-1 (ET-1; 100 nM), potassium chloride (KCl; 100 mM) and norepinephrine (NE; 10 µM). The time to half maximal contraction was shorter in the vena cava compared to aorta (aorta: ET-1 = 235.8 ± 13.8 s, KCl = 140.0 ± 33.3 s, NE = 19.8 ± 2.7 s; vena cava: ET-1 = 121.8 ± 15.6 s, KCl = 49.5 ± 6.7 s, NE = 9.0 ± 3.3 s). Reverse-transcription polymerase chain reaction supported the greater expression of SMB in the vena cava compared to aorta. SMB was expressed to a greater extent than SMA in the vessel wall of the vena cava. Western analysis determined that expression of SMB, relative to total smooth muscle myosin heavy chains, was 12.5 ± 4.9-fold higher in the vena cava compared to aorta, while SMA was 4.9 ± 1.2-fold higher in the aorta than vena cava. Thus, the SMB isoform is the predominant form expressed in rat veins, providing one possible mechanism for the faster response of veins to vasoconstrictors
Large-Scale Forest Inventories Of The United States And China Reveal Positive Effects Of Biodiversity On Productivity
Background
With the loss of species worldwide due to anthropogenic factors, especially in forested ecosystems, it has become more urgent than ever to understand the biodiversity-ecosystem functioning relationship (BEFR). BEFR research in forested ecosystems is very limited and thus studies that incorporate greater geographic coverage and structural complexity are needed.
Methods
We compiled ground-measured data from approx. one half million forest inventory sample plots across the contiguous United States, Alaska, and northeastern China to map tree species richness, forest stocking, and productivity at a continental scale. Based on these data, we investigated the relationship between forest productivity and tree species diversity, using a multiple regression analysis and a non-parametric approach to account for spatial autocorrelation.
Results
In general, forests in the eastern United States consisted of more tree species than any other regions in the country. The highest forest stocking values over the entire study area were concentrated in the western United States and Central Appalachia. Overall, 96.4 % of sample plots (477,281) showed a significant positive effect of species richness on site productivity, and only 3.6 % (17,349) had an insignificant or negative effect.
Conclusions
The large number of ground-measured plots, as well as the magnitude of geographic scale, rendered overwhelming evidence in support of a positive BEFR. This empirical evidence provides insights to forest management and biological conservation across different types of forested ecosystems. Forest timber productivity may be impaired by the loss of species in forests, and biological conservation, due to its potential benefits on maintaining species richness and productivity, can have profound impacts on the functioning and services of forested ecosystems
Endovascular treatment of a Superior Mesenteric Artery Syndrome variant secondary to traumatic pseudoaneurysm
Pseudoaneurysms related to the superior mesenteric artery (SMA) are a recognised complication of trauma to the vessel, and successful treatment with stenting has been previously described. We report the case of a patient who presented with obstruction of the fourth part of the duodenum secondary to a traumatic pseudoaneurysm, a hitherto unreported variant of superior mesenteric artery syndrome. Exclusion of the pseudoaneurysm and relief of the duodenal obstruction were simultaneously achieved by placement of a covered stent
miR-200a Prevents Renal Fibrogenesis Through Repression of TGF-β2 Expression
OBJECTIVE: Progressive fibrosis in the diabetic kidney is driven and sustained by a diverse range of profibrotic factors. This study examines the critical role of microRNAs (miRNAs) in the regulation of the key fibrotic mediators, TGF-β1 and TGF-β2. RESEARCH DESIGN AND METHODS: Rat proximal-tubular epithelial cells (NRK52E) were treated with TGF-β1 and TGF-β2 for 3 days, and expression of markers of epithelial-to-mesenchymal transition (EMT) and fibrogenesis were assessed by RT-PCR and Western blotting. The expression of miR-141 and miR-200a was also assessed, as was their role as translational repressors of TGF-β signaling. Finally, these pathways were explored in two different mouse models, representing early and advanced diabetic nephropathy. RESULTS: Both TGF-β1 and TGF-β2 induced EMT and fibrogenesis in NRK52E cells. TGF-β1 and TGF-β2 also downregulated expression of miR-200a. The importance of these changes was demonstrated by the finding that ectopic expression miR-200a downregulated smad-3 activity and the expression of matrix proteins and prevented TGF-β-dependent EMT. miR-200a also downregulated the expression of TGF-β2, via direct interaction with the 3' untranslated region of TGF-β2. The renal expression of miR-141 and miR-200a was also reduced in mouse models representing early and advanced kidney disease. CONCLUSIONS: miR-200a and miR-141 significantly impact on the development and progression of TGF-β-dependent EMT and fibrosis in vitro and in vivo. These miRNAs appear to be intricately involved in fibrogenesis, both as downstream mediators of TGF-β signaling and as components of feedback regulation, and as such represent important new targets for the prevention of progressive kidney disease in the context of diabetes
The Future of Women\u27s Studies (Continued)
from the CALIFORNIA STATE UNIVERSITY, CHICO
Women\u27s Studies at Chico developed from courses offered by women in their different departments, gathered to form a minor degree program in spring, 1973. Two specifically women\u27s studies courses were designed at that time: a team-taught Introduction to Women\u27s Studies (draws around 80 students a semester, changes women students\u27 expectations and horizons by projecting models of achieving women) and a Senior Research Seminar designed to integrate the students\u27 major and minor. Both are taught by the Women\u27s Studies Coordinator. Student demand has led to the development of new courses whose content received a great deal of student input: Women\u27s Health, Women in the Working World, Women in Art, Minority Women and the Re-Entry Program for Mature Women. There are now 20 courses offered through the Women\u27s Studies Program. Students are designing special degrees on the B.A. and M.A. level in areas such as Women and Counseling, Psychology and Art.
...from the CITY COLLEGE OF THE CITY UNIVERSITY OF NEW YORK...
...from FLORIDA INTERNATIONAL UNIVERSITY...
...from the JERSEY CITY STATE COLLEGE...
...from the UNIVERSITY OF MARYLAND...
...from UNIVERSITY OF MASSACHUSETTS/AMHERST...
...from the UNIVERSITY OF MINNESOTA...
...from the UNIVERSITY OF SOUTH FLORIDA..
Towards country-specific nitrous oxide emission factors for manures applied to arable and grassland soils in the UK
Nitrous oxide (N2O) emission factors (EFs) were calculated from measurements of emissions from livestock manures applied to UK arable crops and grassland as part of a wider research programme to reduce uncertainty in the UK national agricultural N2O inventory and to enhance regional inventory reporting through increased understanding of processes and factors controlling emissions. Field studies were undertaken between 2011 and 2013 at 3 arable and 3 grassland sites in the UK. Nitrous oxide emissions were measured following the autumn and spring application of different manures (pig slurry, cattle slurry, cattle farmyard manure (FYM), pig FYM, poultry layer manure, and broiler litter) at typical rates, using representative manure application and soil incorporation methods. In addition, ammonia emissions and nitrate leaching losses (1 site on a light sandy soil) were measured to calculate indirect N2O losses. IPCC comparable, direct N2O EFs ranged from −0.05 to 2.30% of total nitrogen applied, with the variability driven by a range of factors including differences in manure composition, application method, incorporation and climatic conditions. When data from the autumn applications were pooled, the mean N2O EF from poultry manure (1.52%) was found to be greater (P < 0.001) than from FYM (0.37%) and slurry (0.72%), with no difference found (P = 0.784) in the EF for bandspread compared with surface broadcast slurry application, and no effect (P = 0.328) of the nitrification inhibitor, Dicyandiamide (DCD). For the spring applications, the mean N2O EF for bandspread slurry (0.56%) was greater (P = 0.028) than from surface broadcast slurry (0.31%), but there were no differences (P = 0.212) in the mean N2O EFs from poultry manure (0.52%), slurry (0.44%), and FYM (0.22%). The study did confirm, however, that DCD reduced N2O emissions from slurries applied in the spring by 45%. EF data from this project have been used in the derivation of robust Tier 2 country specific EFs for inclusion in the UK national agriculture greenhouse gas inventory
Severe Congenital Heart Defects and Cerebral Palsy
Objective: To report the prevalence of cerebral palsy (CP) in children with severe congenital heart defects (sCHD) and the outcome/severity of the CP.
Methods: Population-based, data linkage study between CP and congenital anomaly registers in Europe and
Australia. The EUROCAT definition of severe CHD (sCHD) was used. Linked data from 4 regions in Europe and 2 in Australia were included. All children born in the regions from 1991 through 2009 diagnosed with CP and/or sCHD were included. Linkage was completed locally. Deidentified linked data were pooled for analyses.
Results:The study sample included 4989 children with CP and 3684 children with sCHD. The total number of livebirths in the population was 1 734 612. The prevalence of CP was 2.9 per 1000 births (95% CI, 2.8-3.0) and the prevalence of sCHD was 2.1 per 1000 births (95% CI, 2.1-2.2). Of children with sCHD, 1.5% (n = 57) had a diagnosis of CP, of which 35 (61%) children had prenatally or perinatally acquired CP (resulting from a brain injury at £28 days of life) and 22 (39%) children had a postneonatal cause (a brain injury between 28 days and 2 years). Children with CP and sCHD more often had unilateral spastic CP and more intellectual impairments than children with CP without congenital anomalies.Conclusions: In high-income countries, the proportion of children with CP is much higher in children with sCHD than in the background population. The severity of disease in children with CP and sCHD is milder compared with children with CP without congenital anomaliesFunding support received for the overarching Comprehensive CA-CP Study: the Cerebral Palsy Alliance Research Foundation (The Comprehensive CA-CP Study PG1215 and PG2816 and salary support from Cerebral Palsy Alliance Research Foundation (S.G., S.M., H.S.S., N.B.).info:eu-repo/semantics/publishedVersio
Clinical effectiveness and cost-effectiveness of a multifaceted podiatry intervention for falls prevention in older people : a multicentre cohort randomised controlled trial (the REducing Falls with ORthoses and a Multifaceted podiatry intervention trial)
BACKGROUND: Falls are a serious cause of morbidity and cost to individuals and society. Evidence suggests that foot problems and inappropriate footwear may increase the risk of falling. Podiatric interventions could help reduce falls; however, there is limited evidence regarding their clinical effectiveness and cost-effectiveness. OBJECTIVES: To determine the clinical effectiveness and cost-effectiveness of a multifaceted podiatry intervention for preventing falls in community-dwelling older people at risk of falling, relative to usual care. DESIGN: A pragmatic, multicentred, cohort randomised controlled trial with an economic evaluation and qualitative study. SETTING: Nine NHS trusts in the UK and one site in Ireland. PARTICIPANTS: In total, 1010 participants aged ≥ 65 years were randomised (intervention, n = 493; usual care, n = 517) via a secure, remote service. Blinding was not possible. INTERVENTIONS: All participants received a falls prevention leaflet and routine care from their podiatrist and general practitioner. The intervention also consisted of footwear advice, footwear provision if required, foot orthoses and foot- and ankle-strengthening exercises. MAIN OUTCOME MEASURES: The primary outcome was the incidence rate of falls per participant in the 12 months following randomisation. The secondary outcomes included the proportion of fallers and multiple fallers, time to first fall, fear of falling, fracture rate, health-related quality of life (HRQoL) and cost-effectiveness. RESULTS: The primary analysis consisted of 484 (98.2%) intervention and 507 (98.1%) usual-care participants. There was a non-statistically significant reduction in the incidence rate of falls in the intervention group [adjusted incidence rate ratio 0.88, 95% confidence interval (CI) 0.73 to 1.05; p = 0.16]. The proportion of participants experiencing a fall was lower (50% vs. 55%, adjusted odds ratio 0.78, 95% CI 0.60 to 1.00; p = 0.05). No differences were observed in key secondary outcomes. No serious, unexpected and related adverse events were reported. The intervention costs £252.17 more per participant (95% CI -£69.48 to £589.38) than usual care, was marginally more beneficial in terms of HRQoL measured via the EuroQoL-5 Dimensions [mean quality-adjusted life-year (QALY) difference 0.0129, 95% CI -0.0050 to 0.0314 QALYs] and had a 65% probability of being cost-effective at the National Institute for Health and Care Excellence threshold of £30,000 per QALY gained. The intervention was generally acceptable to podiatrists and trial participants. LIMITATIONS: Owing to the difficulty in calculating a sample size for a count outcome, the sample size was based on detecting a difference in the proportion of participants experiencing at least one fall, and not the primary outcome. We are therefore unable to confirm if the trial was sufficiently powered for the primary outcome. The findings are not generalisable to patients who are not receiving podiatry care. CONCLUSIONS: The intervention was safe and potentially effective. Although the primary outcome measure did not reach significance, a lower fall rate was observed in the intervention group. The reduction in the proportion of older adults who experienced a fall was of borderline statistical significance. The economic evaluation suggests that the intervention could be cost-effective. FUTURE WORK: Further research could examine whether or not the intervention could be delivered in group sessions, by physiotherapists, or in high-risk patients. TRIAL REGISTRATION: Current Controlled Trials ISRCTN68240461. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 24. See the NIHR Journals Library website for further project information
Isolation of a novel flavanonol and an alkylresorcinol with highly potent anti-trypanosomal activity from Libyan propolis
Twelve propolis samples from different parts of Libya were investigated for their phytochemical constituents. Ethanol extracts of the samples and some purified compounds were tested against Trypanosoma brucei, Plasmodium falciparum and against two helminth species, Trichinella spiralis and Caenorhabditis elegans, showing various degrees of activity. Fourteen compounds were isolated from the propolis samples, including a novel compound Taxifolin-3-acetyl-4’-methyl ether (4), a flavanonol derivative. The crude extracts showed moderate activity against T. spiralis and C. elegans, while the purified compounds had low activity against P. falciparum. Anti-trypanosomal activity (EC50 = 0.7 µg/mL) was exhibited by a fraction containing a cardol identified as bilobol (10) and this fraction had no effect on Human Foreskin Fibroblasts (HFF), even at 2.0 mg/mL, thus demonstrating excellent selectivity. A metabolomics study was used to explore the mechanism of action of the fraction and it revealed significant disturbances in trypanosomal phospholipid metabolism, especially the formation of choline phospholipids. We conclude that a potent and highly selective new trypanocide may be present in the fraction
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