575 research outputs found
Arkansas Cotton Variety Test 1999
The primary aim of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties in the major cotton growing areas in Arkansas. This information helps seed dealers establish marketing strategies and assists producers in choosing varieties to plant. In this way the annual test facilitates the inclusion of new, improved genetic material into Arkansas cotton production. The 1999 test had 67 entries (including 25 transgenic genotypes and 35 first-year entries), which were evaluated at sixsites in eastern Arkansas. The presence of four transgenic and five first-year entries among the top 10 yielding entries suggests that improvement is being accomplished in varietal development. This report also includes the Mississippi County Variety Test (an on-farm evaluation of selected varieties) and on-farm variety trials conducted by the Cooperative Extension Service
Statins as Potential Chemoprevention or Therapeutic Agents in Cancer: a Model for Evaluating Repurposed Drugs
Purpose of Review:
Repurposing established medicines for a new therapeutic indication potentially has important global and societal impact. The high costs and slow pace of new drug development have increased interest in more cost-effective repurposed drugs, particularly in the cancer arena. The conventional drug development pathway and evidence framework are not designed for drug repurposing and there is currently no consensus on establishing the evidence base before embarking on a large, resource intensive, potential practice changing phase III randomised controlled trial (RCT). Numerous observational studies have suggested a potential role for statins as a repurposed drug for cancer chemoprevention and therapy, and we review the strength of the cumulative evidence here.
Recent Findings:
In the setting of cancer, a potential repurposed drug, like statins, typically goes through a cyclical history, with initial use for several years in another disease setting, prior to epidemiological research identifying a possible chemo-protective effect. However, further information is required, including review of RCT data in the initial disease setting with exploration of cancer outcomes. Additionally, more contemporary methods should be considered, such as Mendelian randomization and pharmaco-epidemiological research with “target” trial design emulation using electronic health records. Pre-clinical and traditional observational data potentially support the role of statins in the treatment of cancer; however, randomised trial evidence is not supportive. Evaluation of contemporary methods provides little added support for the use of statin therapy in cancer.
Summary:
We provide complementary evidence of alternative study designs to enable a robust critical appraisal from a number of sources of the go/no-go decision for a prospective phase III RCT of statins in the treatment of cancer
Nutrition or Detoxification: Why Bats Visit Mineral Licks of the Amazonian Rainforest
Many animals in the tropics of Africa, Asia and South America regularly visit so-called salt or mineral licks to consume clay or drink clay-saturated water. Whether this behavior is used to supplement diets with locally limited nutrients or to buffer the effects of toxic secondary plant compounds remains unclear. In the Amazonian rainforest, pregnant and lactating bats are frequently observed and captured at mineral licks. We measured the nitrogen isotope ratio in wing tissue of omnivorous short-tailed fruit bats, Carollia perspicillata, and in an obligate fruit-eating bat, Artibeus obscurus, captured at mineral licks and at control sites in the rainforest. Carollia perspicillata with a plant-dominated diet were more often captured at mineral licks than individuals with an insect-dominated diet, although insects were more mineral depleted than fruits. In contrast, nitrogen isotope ratios of A. obscurus did not differ between individuals captured at mineral lick versus control sites. We conclude that pregnant and lactating fruit-eating bats do not visit mineral licks principally for minerals, but instead to buffer the effects of secondary plant compounds that they ingest in large quantities during periods of high energy demand. These findings have potential implications for the role of mineral licks for mammals in general, including humans
Reduced or modified dietary fat for preventing cardiovascular disease
BACKGROUND: Reduction or modification of dietary fat can improve total cholesterol levels, but may also have a variety of effects, both positive and negative, on other cardiovascular risk factors. OBJECTIVES: The aim of this systematic review was to assess the effect of reduction or modification of dietary fats on total and cardiovascular mortality and cardiovascular morbidity over at least 6 months, using all available randomized clinical trials. SEARCH STRATEGY: The Cochrane Library, MEDLINE, EMBASE, CAB Abstracts, CVRCT registry and related Cochrane Groups' trial registers were searched through spring 1998, SIGLE to January 1999. Trials known to experts in the field and biographies were included through May 1999. SELECTION CRITERIA: Trials fulfilled the following criteria: 1) randomized with appropriate control group, 2) intention to reduce or modify fat or cholesterol intake (excluding exclusively omega-3 fat interventions), 3) not multi factorial, 4) healthy adult humans, 5) intervention at least six months, 6) mortality or cardiovascular morbidity data available. Inclusion decisions were duplicated, disagreement resolved by discussion or a third party. DATA COLLECTION AND ANALYSIS: Rate data were extracted by two independent reviewers and meta-analysis performed using random effects methodology. Meta-regression and funnel plots were used. MAIN RESULTS: Twenty seven studies were included (40 intervention arms, 30,901 person-years). There was no significant effect on total mortality (rate ratio 0.98, 95% CI 0.86 to 1.12), a trend towards protection form cardiovascular mortality (rate ratio 0.91, 95% CI 0.77 to 1.07), and significant protection from cardiovascular events (rate ratio 0.84, 95% CI 0.72 to 0.99). The latter became non-significant on sensitivity analysis. Trials where participants were involved for more than 2 years showed significant reductions in the rate of cardiovascular events and a suggestion of protection from total mortality. The degree of protection from cardiovascular events appeared similar in high and low risk groups, but was statistically significant only in the former. REVIEWER'S CONCLUSIONS: The findings are suggestive of a small but potentially important reduction in cardiovascular risk in trials longer than two years. Lifestyle advice to all those at high risk of cardiovascular disease (especially where statins are unavailable or rationed), and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates
A patient with persistent consolidation and a pulmonary mass
Community-acquired pneumonia is a common condition and 6–24% of patients will fail to improve as expected. We present a patient who was initially treated for community-acquired pneumonia but did not make the anticipated recovery. We explore potential differentials, and the investigation and management of the rare condition we subsequently diagnosed
Sex differences in cardiovascular morbidity associated with familial hypercholesterolaemia: A retrospective cohort study of the UK Simon Broome register linked to national hospital records
Background and aims: The UK Simon Broome (SB) familial hypercholesterolaemia (FH) register previously reported 3-fold higher standardised mortality ratio for cardiovascular disease (CVD) in women compared to men
from 2009 to 2015. Here we examined sex differences in CVD morbidity in FH by national linkage of the SB
register with Hospital Episode Statistics (HES).
Methods: Of 3553 FH individuals in the SB register (aged 20–79 years at registration), 2988 (52.5% women) had
linked HES records. Standardised Morbidity Ratios (SMbR) compared to an age and sex-matched UK general
practice population were calculated [95% confidence intervals] for first CVD hospitalisation in HES (a composite
of coronary heart disease (CHD), myocardial infarction (MI), stable or unstable angina, stroke, TIA, peripheral
vascular disease (PVD), heart failure, coronary revascularisation interventions).
Results: At registration, men had significantly (p < 0.001) higher prevalence of previous CHD (24.8% vs 17.6%),
previous MI (13.2% vs 6.3%), and were commenced on lipid-lowering treatment at a younger age than women
(37.5 years vs 42.3 years). The SMbR for composite CVD was 6.83 (6.33–7.37) in men and 7.55 (6.99–8.15) in
women. In individuals aged 30–50 years, SMbR in women was 50% higher than in men (15.04 [12.98–17.42] vs
10.03 [9.01–11.17]). In individuals >50 years, SMbR was 33% higher in women than men (6.11 [5.57–6.70] vs
4.59 [4.08–5.15]).
Conclusions: Excess CVD morbidity due to FH remains markedly elevated in women at all ages, but especially
those aged 30–50 years. This highlights the need for earlier diagnosis and optimisation of lipid-lowering risk
factor management for all FH patients, with particular attention to young women with FH
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