Multiple mitigation mechanisms: Effects of submerged plants on the toxicity of nine insecticides to aquatic animals.

Understanding the processes that regulate contaminant impacts in nature is an increasingly important challenge. For insecticides in surface waters, the ability of aquatic plants to sorb, or bind, hydrophobic compounds has been identified as a primary mechanism by which toxicity can be mitigated (i.e.

Effects of Pesticide Mixtures on Host-Pathogen Dynamics of the Amphibian Chytrid Fungus.

Anthropogenic and natural stressors often interact to affect organisms. Amphibian populations are undergoing unprecedented declines and extinctions with pesticides and emerging infectious diseases implicated as causal factors. Although these factors often co-occur, their effects on amphibians are usually examined in isolation.

Submerged macrophytes mitigate direct and indirect insecticide effects in freshwater communities.

Understanding how ecological interactions mitigate the impacts of perturbations such as pesticides in biological communities is an important basic and applied question for ecologists. In aquatic ecosystems, new evidence from microcosm experiments suggests that submerged macrophytes can buffer cladocerans from pulse exposures to the widely used insecticide malathion, and that mitigation increases with macrophyte density. However, whether these results scale up to more complex aquatic communities where ecological interactions such as competition can alter toxicity is unknown.

A new mechanism of macrophyte mitigation: how submerged plants reduce malathion's acute toxicity to aquatic animals.

A growing body of evidence suggests that aquatic plants can mitigate the toxicity of insecticides to sensitive aquatic animals. The current paradigm is that this ability is driven primarily by insecticide sorption to plant tissues, especially for hydrophobic compounds. However, recent work shows that submerged plants can strongly mitigate the toxicity of the relatively hydrophilic insecticide malathion, despite the fact that this compound exhibits a slow sorption rate to plants.

Mitigation of malathion's acute toxicity by four submersed macrophyte species.

Some submersed macrophyte species rapidly sorb some insecticides from the water, potentially reducing exposure for aquatic species. The rates at which macrophytes remove insecticides, however, can differ widely among plant species. Furthermore, few studies have examined how much macrophytes actually influence insecticide toxicity to sensitive animals.

Mitigating with macrophytes: submersed plants reduce the toxicity of pesticide-contaminated water to zooplankton.

In ecotoxicology, appreciation is growing for the influence that ecological interactions have on the toxicity of contaminants, such as insecticides, to sensitive species. Most previous studies, however, have focused on factors that exacerbate insecticide effects on species, while factors that may mitigate these effects have been relatively ignored. In aquatic habitats, a small number of studies have shown that submersed macrophytes can remove some insecticides from the water column via sorption.

The role of gene flow asymmetry along an environmental gradient in constraining local adaptation and range expansion.

Theoretically, asymmetric gene flow along an environmental gradient can limit species range expansion by keeping peripheral populations from locally adapting. However, few empirical studies have examined this potentially fundamental evolutionary mechanism. We address this possibility in the cricket Allonemobius socius, which exist along a season-length gradient where the probability of producing a single generation per year (univoltinism) increases with latitude.

Dentofacial features of a family with Crouzon syndrome. Case reports.

Crouzon syndrome is an autosomal dominant condition characterized by craniosynostosis with associated dentofacial anomalies. This paper describes the variable clinical features in affected individuals over two generations of a family with particular reference to the dentofacial deformities and discussion of management strategies.

Secondary alveolar bone grafting--five-year periodontal and radiographic evaluation in 100 consecutive cases.

A prospective study of secondary alveolar bone grafting based on the Norwegian (Oslo) team approach has been conducted by the CLP Unit at the Princess Margaret Hospital for Children in Perth, Australia, since 1982. The 5-year results of 100 consecutive cases of uni- and bilateral cases are presented according to periodontal and radiographic parameters of tooth support. The vast majority of cases grafted (98%) resulted in the eventual eruption of the cleft side cuspid/lateral incisor within acceptable parameters of tooth support.

Prognosis after valve replacement in patients with severe aortic stenosis and a low transvalvular pressure gradient.

Objectives: This study was conducted to determine the risks and benefits of valve replacement in patients with severe aortic stenosis and a low transvalvular pressure gradient.

Background: There is uncertainty regarding the appropriate management of adults with severe aortic stenosis and a transvalvular pressure gradient < or = 30 mm Hg. With only six such patients reported, one study suggested that these subjects have a prohibitive operative risk and little symptomatic improvement if they survive surgical treatment, whereas another showed that they can survive an operation and improve symptomatically.

Rotational coronary atherectomy after unsuccessful coronary balloon angioplasty.

The clinical and angiographic outcome of patients undergoing rotational coronary atherectomy after unsuccessful balloon angioplasty was evaluated using quantitative angiographic methods to provide insight into this procedure's mechanism of benefit. During the study period, 41 patients (50 lesions) were referred for rotational atherectomy after standard balloon angioplasty was unsuccessful. After rotational atherectomy, percent diameter stenosis was reduced from 72 +/- 14% to 41 +/- 16% (p < 0.

Effect of coronary angioplasty on late potentials one to two weeks after acute myocardial infarction.

In survivors of acute myocardial infarction (AMI), the restoration of anterograde flow in the infarct artery, even if accomplished beyond the time for myocardial salvage, may reduce the frequency of subsequent arrhythmic events and sudden death. Twelve subjects (8 men and 4 women, aged 39 to 69 years) with a first AMI, signal-averaged electrocardiographic late potentials, and an occluded infarct artery were prospectively identified. Seven (group I) had successful coronary angioplasty 6 to 15 days after AMI, and 5 (group II) were managed conservatively.

The natural history of isolated left ventricular diastolic dysfunction.

Study Objective: To assess the natural history of isolated left ventricular diastolic dysfunction.

Patients And Methods: Follow-up (average duration, 68 months) was obtained in 51 patients with isolated left ventricular diastolic dysfunction at cardiac catheterization, characterized by (1) an elevated left ventricular end-diastolic pressure; (2) normal left ventricular end-diastolic and end-systolic volumes; (3) normal left ventricular ejection fraction; (4) no coronary artery disease; and (5) no valvular disease.

Results: During follow-up, seven patients died, but only one died of cardiac causes.

Collection and handling of clinical blood samples to assure the accurate measurement of cocaine concentration.

The measurement of serum cocaine concentration is difficult because it is rapidly metabolized in vivo and in vitro. Previous investigators have used sodium fluoride (0.5-3.

Comparison of single and biplane ventriculography for determination of left ventricular volume and ejection fraction.

This study was done to compare single and biplane left ventriculography in quantitating left ventricular (LV) volumes and ejection fraction. LV volumes and ejection fraction were measured from a 30 degrees right anterior oblique single plane ventriculogram and a 30 degrees right anterior oblique 60 degrees left anterior oblique biplane ventriculogram in 152 men (aged 59 +/- 9 [mean +/- standard deviation] years), of whom 102 had hypokinesia, akinesia, or dyskinesia. There was excellent agreement between the results of single and biplane ventriculography with respect to LV end-diastolic volume (r = 0.

Accuracy of various methods of measuring the transvalvular pressure gradient in aortic stenosis.

This study was done to assess the accuracy of various techniques of measuring the pressure gradient and valve area in patients with aortic stenosis (AS). In 18 patients with AS, the pressure gradient was quantitated from (1) simultaneous left ventricular and ascending aortic pressures (LV-AO), (2) nonsimultaneous LV-AO pullback, (3) LV and femoral arterial (FA) pressures unadjusted for the time delay of the FA tracing (LV-FA unadjusted), and (4) LV-FA adjusted for time delay. In comparison to simultaneous LV-AO, the pressure gradient was greater with LV-FA unadjusted and less with LV-FA adjusted for time delay (p less than 0.

Recurrent coronary vasoconstriction caused by intranasal cocaine: possible role for metabolites.

Objective: To define the temporal characteristics of cocaine-induced coronary vasoconstriction in humans and to assess the relation between cocaine-induced coronary vasoconstriction and the blood concentration of cocaine and its main metabolites.

Design: Randomized, double-blind, controlled clinical trial.

Setting: Cardiac catheterization laboratory of a large teaching hospital.

Contrast agents for cardiac catheterization: conceptions and misconceptions.

Ionic and nonionic contrast materials are similarly efficacious in providing excellent images with minimal risk to the patient. In comparison with ionic media, the nonionic agents produce minor alterations in intracardiac and peripheral pressures as well as in electrocardiographic intervals and morphology. In addition, nonionic media are less often associated with undesirable symptoms, such as flushing and vomiting.

Alleviation of cocaine-induced coronary vasoconstriction by nitroglycerin.

Cocaine induces vasoconstriction of epicardial coronary arteries in patients with and without coronary artery disease, and this vasoconstriction is particularly marked in segments narrowed by atherosclerosis. To assess the effect of nitroglycerin on cocaine-induced coronary vasoconstriction, computer-assisted quantitative analysis was performed on non-diseased and diseased coronary artery segments in 23 patients (18 men, 5 women, aged 43 to 65 years) 1) at baseline, 2) after administration of intranasal saline solution (in 8 patients) or 2 mg/kg of cocaine (in 15 patients), and then 3) after administration of sublingual placebo (in 6 patients) or 0.4 or 0.

Simplified formula for the calculation of mitral valve area: potential inaccuracies in patients with tachycardia.

A simplified formula (cardiac output/[transvalvular pressure gradient]1/2) has been proposed as an alternative to the Gorlin equation for determining valve area in patients with mitral stenosis. This study was done (a) to assess the relationship between the results of the simplified formula and those of the Gorlin equation in patients with mitral stenosis and (b) to determine the clinical characteristics most likely to be associated with a disparity between the 2 formulae. In 96 patients with mitral stenosis, the disparity between the 2 formulae was greater than 0.

Team approach to the treatment of cleft lip and palate.

We have formed a team consisting of plastic surgeons, dental specialists, Ear, Nose and Throat surgeons and speech therapists. Thus all the clinical needs of the patient can be provided for in the one hospital. The team meets regularly to examine the patients, assess what further treatment is required and to evaluate and criticise the work done on each case up to date.

A videoradiographic investigation of the position of the tongue prior to palatal repair in babies with cleft lip and palate.

Lateral videoradiography was carried out on nine babies, seven with clefts and two without, at rest and while feeding with a barium mixture. No discernible difference was found in tongue movement or position between the cleft and noncleft babies, nor did the presence or absence of a presurgical plate make any difference.