Environ Sci Pollut Res Int
February 2023
There is increasing awareness of the negative ecological and environmental effects of widespread use of pesticides on the landscape. Spillover or drift of pesticides from agricultural areas has been shown to impact species health, reproduction, and trophic dynamics through both direct and indirect mechanisms. Neonicotinoid insecticides are associated with observed declines of insectivorous and grassland birds, and these environmental pollutants are a significant conservation concern for many species that have experienced past or current population declines.
View Article and Find Full Text PDFThe butterfly fauna of lowland Northern California has exhibited a marked decline in recent years that previous studies have attributed in part to altered climatic conditions and changes in land use. Here, we ask if a shift in insecticide use towards neonicotinoids is associated with butterfly declines at four sites in the region that have been monitored for four decades. A negative association between butterfly populations and increasing neonicotinoid application is detectable while controlling for land use and other factors, and appears to be more severe for smaller-bodied species.
View Article and Find Full Text PDFIn metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern.
View Article and Find Full Text PDFPopulation trends represent a minimum amount of information required to assess the conservation status of a species. However, understanding and detecting trends can be complicated by variation among habitats and regions, and by dispersal connecting habitats through source-sink dynamics. We analyzed trends in breeding populations between habitats and regions to better understand the overall dynamics of a species' decline.
View Article and Find Full Text PDFThe focus of new research efforts to improve the morbidity and mortality associated with acute myocardial infarction (AMI) has turned to adjuvant agents that show promise of improving outcomes following coronary thrombolysis. We enrolled 162 patients with AMI in a randomized trial comparing front-loaded tissue-plasminogen activator (t-PA) plus weight-adjusted heparin with anisoylated plasminogen streptokinase activator complex (APSAC) without heparin as well as standard-dose (325 mg) and low-dose (81 mg) aspirin. The primary end point was an in-hospital morbidity profile; secondary end points were clinical and angiographic potency and hemorrhagic events.
View Article and Find Full Text PDFObjectives: We designed a randomized trial to evaluate the effects of heparin administration in conjunction with anistreplase (anisoylated plasminogen streptokinase activator complex [APSAC]) on arterial patency and clinical end points.
Background: The role of conjunctive intravenous heparin therapy with APSAC has not been tested despite the recommendations that intravenous heparin should be used.
Methods: Four hours after APSAC administration, 250 patients with acute myocardial infarction were randomly assigned to receive 325 mg of either aspirin alone or aspirin and a continuous infusion of heparin (15 IU/kg body weight per h).
The capability of dynamic gradient-refocused magnetic resonance imaging (cine MRI) to detect, localize and functionally assess acute myocardial infarction (AMI) in 25 patients at a mean time interval of 7 days after AMI was evaluated. Fifteen asymptomatic volunteers were also examined to determine the specificity of the observations. Upon presentation, each patient received intravenous thrombolytic therapy, underwent immediate cardiac catheterization and had percutaneous transluminal coronary angioplasty performed when coronary reperfusion was absent.
View Article and Find Full Text PDFLeft ventricular hypertrophy is associated with decreased longevity and often leads to congestive heart failure. An exploratory study of magnetic resonance imaging in human left ventricular hypertrophy was performed. First, 13 patients with left ventricular hypertrophy and 7 controls of similar ages were studied using electrocardiogramgated end-diastolic images.
View Article and Find Full Text PDFThe effects of 800 mg of elemental calcium per day (calcium carbonate or calcium citrate) on blood pressure were compared with a placebo in a controlled randomized, crossover, double-blinded trial involving 26 patients with uncomplicated primary hypertension. Each patient took two of the three forms of therapy orally for 8-week intervals with a 2-week washout period in between. Standing mean blood pressure rose an average of 5.
View Article and Find Full Text PDFAntihypertensive therapy significantly reduces cardiovascular morbidity and mortality in the rapidly growing population of elderly patients. However, the desire to treat more of these patients is dampened by the concern that a reduction in blood pressure may compromise cerebral blood flow, causing untoward consequences. This study evaluated the therapeutic effect of titrated doses of prazosin, an alpha-adrenergic blocking agent, on systemic blood pressure and cerebral blood flow in elderly patients with chronic stable hypertension.
View Article and Find Full Text PDFPrimary (essential) hypertension has recently been related to calcium deficiency, rather than excess. The evidence used to support this hypothesis includes surveys showing lesser dietary intake of calcium, lower levels of ionized calcium in the blood, and reduction of blood pressure with calcium supplements. This critique examines each of these points and the theoretical construct used to explain the hypothesis.
View Article and Find Full Text PDFArch Intern Med
November 1985
Sudden onset of a hypertensive crisis occurred shortly after induction of anesthesia in a patient with malignant pheochromocytoma, despite preoperative medical preparation with alpha-methyltyrosine (alpha-methyl-p-tyrosine) and propranolol hydrochloride. Other investigators have advocated alpha-methyltyrosine as the medical therapy of choice in the preoperative preparation of patients with pheochromocytoma. This case emphasizes the caution that should be exercised when using alpha-methyltyrosine preoperatively, without concurrent alpha-adrenergic blocking agents, to prevent intraoperative hypertensive crisis.
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