Tolerance to mercury in two populations of the grass shrimpPalaemonetes pugio was examined at different stages of this animal's life cycle. One population came from a mercury-contaminated creek, Piles Creek (PC), near industrialized Linden, New Jersey. The other population came from a relatively clean area, Big Sheepshead Creek (BSC), near non-industrialized Tuckerton, New Jersey. Larval grass shrimp showed no significant difference between populations in terms of mortality in 0.01 mg/L HgCl2, although treated BSC larvae metamorphosed significantly (P < 0.05) more slowly than their respective control group. While no BSC larvae survived the 0.0125 mg/L methylmercuric chloride (meHg) treatment, PC larvae exposed to 0.0125 mg/L meHg survived as well as their controls, indicating enhanced tolerance to meHg in this population.Adult shrimp were exposed for 14 days to control, 0.025 mg/L meHg, 0.025 mg/L HgCl2, 0.05 mg/L meHg, or 0.05 mg/L HgCl2 PC shrimp were significantly (P < 0.05) more tolerant to both 0.025 mg/L meHg, and 0.025 mg/L HgCl2 than were the BSC adults.Polyacrylamide gel electrophoresis suggests that both populations of shrimp are capable of producing a metallothionein like protein (MT) in response to treatment with HgCl2; MT is found in higher levels in field-caught PC shrimp than in field-caught BSC shrimp. MT was not present in field-collected, viable eggs from either population. 相似文献
Abstract. Medical and social problems related to alcohol use are frequently seen in the ED. Often, the tempo of emergency medicine practice seems to preclude assessment beyond that required by the acute complaint. However, detection of ED patients with alcohol problems can occur using brief screening tools. This article was developed by members of the SAEM Substance Abuse Task Force, and describes screening tools that have been used successfully to identify atrisk and dependent drinkers. Their brevity, reproducibility, and accuracy vary somewhat, but screening can be realistically performed in the busy ED setting. The early detection of patients with alcohol problems would provide the opportunity for early intervention, and may reduce subsequent morbidity and mortality in this patient population. 相似文献
The purpose of this study was to assess the effectiveness and safety of Gadolite Oral Suspension as a gastrointestinal (GI) contrast agent for MRI in a phase II and two phase III multicenter clinical trials. Gadolite was administered to 306 patients with known or suspected abdominal and/or pelvic disease. MRI with T1- and T2-weighted sequences was performed before and after ingestion. Efficacy was evaluated by having two masked readers rate the certainty of their MR diagnosis (0 = uncertain, 1 = probable, 2 = definite) on randomly presented pre- and post-Gadolite Oral Suspension enhanced images. Principal investigators also evaluated the images and established the final diagnosis. Vital signs, clinical chemistries, and adverse events were documented. Blood and urine samples were analyzed for gadolinium content to determine whether Gadolite Oral Suspension was absorbed systemically. Certainty in MR diagnosis increased significantly (P < .001) for both blinded readers between pre- and post-Gadolite images (.49–1.18 for reader 1; .46–1.53 for reader 2). Sensitivity, specificity, and accuracy also increased for both masked readers. No gadolinium was detected in blood or urine samples. There were no serious adverse events and no apparent drug-related trends in mean vital signs or laboratory values. Gadolite is a highly effective, safe, and well tolerated contrast agent for clinical use with MRI. 相似文献
Background: Biphasic waveform shocks are more effective than monophasic shocks for transchest ventricular defibrillation, atrial cardioversion, and defibrillation with implantable defibrillators but have not been studied for open chest, intraoperative defibrillation. This prospective, blinded, randomized clinical study compares biphasic and monophasic shock effectiveness and establishes intraoperative energy dose-response curves.
Methods: Patients undergoing cardiothoracic surgery with bypass cardioplegia were randomly assigned to the monophasic or biphasic shock group. Ventricular fibrillation occurring after aortic clamp removal was treated with escalating energies of 2, 5, 7, 10, and 20 J until defibrillation occurred. If ventricular fibrillation persisted, a 20-J crossover shock of the other waveform was used.
Results: Cumulative defibrillation success at 5 J, the primary end point of the study, was higher in the biphasic group than in the monophasic group (25 of 50 vs. 9 of 41 defibrillated;P = 0.011). In addition, the biphasic group required lower threshold energy (6.8 vs. 11.0 J;P = 0.003), less cumulative energy (12.6 vs. 23.4 J;P = 0.002), and fewer shocks (2.5 vs. 3.5;P = 0.002). Crossover-shock effectiveness did not differ between groups. Dose-response curves show biphasic shocks to have higher cumulative success rates at all energies tested. 相似文献