175 research outputs found
Improving question formulation for use in evidence appraisal in a tertiary care setting: a randomised controlled trial [ISRCTN66375463]
BACKGROUND: The specificity of clinical questions is gauged by explicit descriptions of four dimensions: subjects, interventions, comparators and outcomes of interest. This study determined whether adding simple instructions and examples on clinical question formulation would increase the specificity of the submitted question compared to using a standard form without instructions and examples. METHODS: A randomised controlled trial was conducted in an evidence-search and appraisal service. New participants were invited to reformulate clinical queries. The Control Group was given no instructions. The Intervention Group was given a brief explanation of proper formulation, written instructions, and diagrammatic examples. The primary outcome was the change in the proportion of reformulated questions that described each the dimensions of specificity. RESULTS: Fifty-two subjects agreed to participate in the trial of which 13 were lost to follow-up. The remaining 17 Intervention Group and 22 Control Group participants were analysed. Baseline characteristics were comparable. Overall, 20% of initially submitted questions from both groups were properly specified (defined as an explicit statement describing all dimensions of specificity). On follow-up, 7/14 questions previously rated as mis-specified in the Intervention Group had all dimensions described at follow-up (p = 0.008) while the Control Group did not show any changes from baseline. Participants in the Intervention Group were also more likely to explicitly describe patients (p = 0.028), comparisons (p = 0.014), and outcomes (p = 0.008). CONCLUSIONS: This trial demonstrated the positive impact of specific instructions on the proportion of properly-specified clinical queries. The evaluation of the long-term impact of such changes is an area of continued research
Follow-up Observations of the Neptune Mass Transiting Extrasolar Planet HAT-P-11b
We have confirmed the existence of the transiting super Neptune extrasolar
planet HAT-P-11b. On May 1, 2009 UT the transit of HAT-P-11b was detected at
the University of Arizona's 1.55m Kuiper Telescope with 1.7 millimag rms
accuracy. We find a central transit time of T_c = 2454952.92534+/-0.00060 BJD;
this transit occurred 80+/-73 seconds sooner than previous measurements (71
orbits in the past) would have predicted. Hence, our transit timing rules out
the presence of any large (>200 s) deviations from the ephemeris of Bakos et
al. (2009). We obtain a slightly more accurate period of
P=4.8878045+/-0.0000043 days. We measure a slightly larger planetary radius of
R_p=0.452+/-0.020 R_J (5.07+/-0.22 R_earth) compared to Bakos and co-workers'
value of 0.422+/-0.014 R_J (4.73+/-0.16 R_earth). Our values confirm that
HAT-P-11b is very similar to GJ 436b (the only other known transiting super
Neptune) in radius and other bulk properties.Comment: accepted to ApJ Letters, 11 pages, 2 figures (see Dittmann et al.
2009 ApJ 699 L48-L51
Centerscope
Centerscope, formerly Scope, was published by the Boston University Medical Center "to communicate the concern of the Medical Center for the development and maintenance of improved health care in contemporary society.
Chinese Medicinal Herbs in Relieving Perimenopausal Depression: A Randomized, Controlled Trial
Abstract Objective: To explore the effects of GengNianLe (GNL, also called perimenopausal depression relieving formula), a defined formula of Chinese medicinal herbs in relieving perimenopausal depression in Chinese women. Methods : Between September 2004 and April 2008, 47 Chinese women were randomized into a GNL group (n ϭ 21) and a control group which received tibolone (n ϭ 26) using a randomization chart. Depression was rated with the 24-item Hamilton Depression Scale (HAMD). The serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E 2 ) were detected before and after the treatment. Results: After 12 weeks of treatment, HAMD scores in both groups decreased significantly (p Ͻ 0.05) with no significant difference between the groups (p Ͼ 0.05). The levels of FSH decreased significantly and the level of E 2 increased significantly in both groups, and they changed more in the control group. No side-effect of treatment was reported in either group during treatment. Conclusions: The Chinese medicinal formula GNL showed promise in relieving perimenopausal depression and merits further study. 9
Use of antihypertensive medications in pregnancy and the risk of adverse perinatal outcomes: McMaster Outcome Study of Hypertension In Pregnancy 2 (MOS HIP 2)
BACKGROUND: Uncertainty remains about the potential harmful effects of antihypertensive therapy on the developing fetus, especially for beta-blockers (βb). METHODS: We prospectively enrolled all singleton women with a blood pressure ≥ 140/90 mm Hg during pregnancy. The main analysis included 1948 women with all forms of hypertension and compared the use of βb drugs, non-βb drugs or a combination of both, to no treatment. The primary study outcome was a composite of the diseases of prematurity, need for assisted ventilation for greater than 1 day, or perinatal death. A sub-group analysis evaluated the four treatment options among 583 singleton women with chronic hypertension before 20 weeks gestation. RESULTS: In the main analysis, no association was observed between βb use and the primary composite outcome [adjusted odds ratio (OR) 1.4, 95% CI 0.9–2.2], while an association was seen with non-βb therapy (OR 5.0, 95% CI 2.6–9.6) and combination therapy (OR 2.9, 95% CI 1.8–4.7). In the sub-group of 583 women with hypertension before 20 weeks, use of a non-βb drug (OR 4.9, 95% CI 1.7–14.2) or combination therapy (OR 2.9. 95% CI 1.1–7.7) was significantly associated with the primary composite outcome, while βb monotherapy was not (OR 1.4, 95% CI 0.6–3.4). CONCLUSIONS: Maternal use of antihypertensive medications other than βbs was associated with both major perinatal morbidity and mortality, while βb monotherapy was not. The combined use of βb and non-βb medications demonstrated the strongest association. Before definitive conclusions can be drawn, a large multicentre randomized controlled trial is needed to address the issues of both maternal efficacy and fetal safety with the use of one or more antihypertensive agents in pregnancy
Zeta-carotene isomerase (Z-ISO) is required for light-independent carotenoid biosynthesis in the cyanobacterium Synechocystis sp. PCC 6803
Carotenoids are crucial photosynthetic pigments utilized for light harvesting, energy transfer, and photoprotection. Although most of the enzymes involved in carotenoid biosynthesis in chlorophototrophs are known, some are yet to be identified or fully characterized in certain organisms. A recently characterized enzyme in oxygenic phototrophs is 15-cis-zeta(ζ)-carotene isomerase (Z-ISO), which catalyzes the cis-to-trans isomerization of the central 15–15′ cis double bond in 9,15,9′-tri-cis-ζ-carotene to produce 9,9′-di-cis-ζ-carotene during the four-step conversion of phytoene to lycopene. Z-ISO is a heme B-containing enzyme best studied in angiosperms. Homologs of Z-ISO are present in organisms that use the multi-enzyme poly-cis phytoene desaturation pathway, including algae and cyanobacteria, but appear to be absent in green bacteria. Here we confirm the identity of Z-ISO in the model unicellular cyanobacterium Synechocystis sp. PCC 6803 by showing that the protein encoded by the slr1599 open reading frame has ζ-carotene isomerase activity when produced in Escherichia coli. A Synechocystis Δslr1599 mutant synthesizes a normal quota of carotenoids when grown under illumination, where the photolabile 15–15′ cis double bond of 9,15,9′-tri-cis-ζ-carotene is isomerized by light, but accumulates this intermediate and fails to produce ‘mature’ carotenoid species during light-activated heterotrophic growth, demonstrating the requirement of Z-ISO for carotenoid biosynthesis during periods of darkness. In the absence of a structure of Z-ISO, we analyze AlphaFold models of the Synechocystis, Zea mays (maize), and Arabidopsis thaliana enzymes, identifying putative protein ligands for the heme B cofactor and the substrate-binding site
PTPN11 mosaicism causes a spectrum of pigmentary and vascular neurocutaneous disorders and predisposes to melanoma
Phakomatosis pigmentovascularis (PPV) is a diagnosis which denotes the coexistence of pigmentary and vascular birthmarks of specific types, accompanied by variable multisystem involvement including central nervous system disease, asymmetrical growth and a predisposition to malignancy. Using a tightly phenotyped group and high depth next generation sequencing of affected tissues we discover here clonal mosaic variants in gene PTPN11 encoding SHP2 phosphatase as a cause of PPV type III or spilorosea. Within an individual the same variant is found in distinct pigmentary and vascular birthmarks and is undetectable in blood. We go on to demonstrate that the same variants can cause either the specific pigmentary or vascular phenotypes alone, as well as driving melanoma development within the pigmentary lesion. Protein conformational modelling highlights that while variants lead to loss of function at the level of the phosphatase domain, resultant conformational changes promote longer ligand binding. In vitro modelling of the missense variants confirms downstream MAPK pathway overactivation, and widespread disruption of human endothelial cell angiogenesis. Importantly, PTPN11-mosaic patients theoretically risk passing on the variant to their children as the germline RASopathy Noonan syndrome with lentigines. These findings improve our understanding of the pathogenesis and biology of naevus spilus and capillary malformation syndromes, paving the way for better clinical management
Operationalizing frailty among older residents of assisted living facilities
<p>Abstract</p> <p>Background</p> <p>Frailty in later life is viewed as a state of heightened vulnerability to poor outcomes. The utility of frailty as a measure of vulnerability in the assisted living (AL) population remains unexplored. We examined the feasibility and predictive accuracy of two different interpretations of the Cardiovascular Health Study (CHS) frailty criteria in a population-based sample of AL residents.</p> <p>Methods</p> <p>CHS frailty criteria were operationalized using two different approaches in 928 AL residents from the Alberta Continuing Care Epidemiological Studies (ACCES). Risks of one-year mortality and hospitalization were estimated for those categorized as frail or pre-frail (compared with non-frail). The prognostic significance of individual criteria was explored, and the area under the ROC curve (AUC) was calculated for select models to assess the utility of frailty in predicting one-year outcomes.</p> <p>Results</p> <p>Regarding feasibility, complete CHS criteria could not be assessed for 40% of the initial 1,067 residents. Consideration of supplementary items for select criteria reduced this to 12%. Using absolute (CHS-specified) cut-points, 48% of residents were categorized as frail and were at greater risk for death (adjusted risk ratio [RR] 1.75, 95% CI 1.08-2.83) and hospitalization (adjusted RR 1.54, 95% CI 1.20-1.96). Pre-frail residents defined by absolute cut-points (48.6%) showed no increased risk for mortality or hospitalization compared with non-frail residents. Using relative cut-points (derived from AL sample), 19% were defined as frail and 55% as pre-frail and the associated risks for mortality and hospitalization varied by sex. Frail (but not pre-frail) women were more likely to die (RR 1.58 95% CI 1.02-2.44) and be hospitalized (RR 1.53 95% CI 1.25-1.87). Frail and pre-frail men showed an increased mortality risk (RR 3.21 95% CI 1.71-6.00 and RR 2.61 95% CI 1.40-4.85, respectively) while only pre-frail men had an increased risk of hospitalization (RR 1.58 95% CI 1.15-2.17). Although incorporating either frailty measure improved the performance of predictive models, the best AUCs were 0.702 for mortality and 0.633 for hospitalization.</p> <p>Conclusions</p> <p>Application of the CHS criteria for frailty was problematic and only marginally improved the prediction of select adverse outcomes in AL residents. Development and validation of alternative approaches for detecting frailty in this population, including consideration of female/male differences, is warranted.</p
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