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showing 10 items of 38174 documents
Control of ovarian steroidogenesis by insulin-like peptides in the blowfly (Phormia regina).
2004
0022–0795/04/0181–147; This study investigated the ability of insulin and of insect insulin-like peptides (ILPs) to stimulate ovarian steroidogenesis in the blowfly Phormia regina. Bovine insulin was active on ovaries isolated in vitro, which showed an age-dependent sensitivity; this peptide progressively stimulated steroidogenesis in ovaries isolated from the third day after adult molt, but not in younger ones, and had maximal activity after the fifth day. This stimulatory effect was observed equally from females reared in the presence or in the absence of males, excluding a regulatory effect of mating. The mode of action of insulin in blowflies did not involve cAMP, but triggered a specif…
Effect of CYP1A1 Gene Polymorphisms on Estrogen Metabolism and Bone Density
2004
UNLABELLED: In this study, we evaluated the effect of polymorphisms of the CYP1A1 gene, linked to hormone-related cancers, on estrogen metabolism and BMD. We found that variants carrying the A allele (CA and AA) for the C4887A polymorphism have a significantly higher degree of estrogen catabolism and lower femoral BMD. INTRODUCTION: Polymorphisms of the CYP1A1 gene, one of the key enzymes that metabolize estrogen, have been linked with hormone-related cancers. We investigated the impact of these polymorphisms on estrogen metabolism and BMD, which is another hormone-dependent health issue. MATERIALS AND METHODS: One hundred seventy postmenopausal women (mean age, 63.5 +/- 0.6 years) particip…
Short- and long-term effects of vinblastine on the rat adrenal medulla
1979
The effects of a single high dose (10mg/kg) of vinblastine (vb) sulfate (“Velbe”, Lilly) on the ultrastructure, catecholamine (CA) content and activity of CA-synthesizing enzymes of the rat adrenal medulla were studied for up to 120h after intravenous injection of the drug.
Diagnostic efficacy of the fluorometric determination of enzyme activity for Pompe disease from dried blood specimens compared with lymphocytes-possi…
2009
Pompe disease is a rare, autosomal-recessive disorder which results from a defect in the lysosomal enzyme acid alpha-glucosidase (GAA). The onset of this disease is highly variable, with infantile types being the most severe. Traditionally, lymphocytes, fibroblasts or muscle biopsies were necessary for enzyme activity measurement, because these materials do not express maltase-glucoamylase (MGA) that interferes with the assay. Recently, acarbose was found to inhibit MGA activity selectively, so that dried blood became accessible for GAA assessment.To evaluate the diagnostic efficacy of GAA measurement in dried blood specimens (DBSs) in comparison with lymphocytes. If DBSs provided reliable …
Short term treatment by fenofibrate enhances oxidative activities towards longchain fatty acids in the liver of lean zucker rats
1990
Lean Zucker rats were dosed orally for 1 week with fenofibrate (100 mg/kg/day). Liver weights of treated rats, expressed as per cent of body weight, were increased, while protein, DNA and triacylglycerol contents were not changed to any great extent per gram of liver, but increased when expressed per whole liver. Compared with the control animals, activities of fatty acid oxidase, of the peroxisomal fatty acid-oxidizing system and of catalase were markedly enhanced by fenofibrate, both per gram of liver and per total liver, while urate oxidase activity was slightly depressed when expressed per gram of liver. The activity of cytochrome c oxidase used as a mitochondrial marker was only higher…
The induction of hepatic microsomal metabolism in rats following acute administration of a mixture of polybrominated biphenyls.
1976
Abstract Firemaster BP6, a mixture of polybrominated biphenyls (PBBs), was administered to female Sprague-Dawley rats (170–180 g) as a single ip injection at 25 and 150 mg/kg. Other animals received phenobarbital (PB), 3-methylcholanthrene (3MC), or PB and 3MC together. Animals were killed at intervals of 12, 24, 48, 192, and 336 hr after treatment with PBBs, or 24 hr after PB, MC, or PB-MC, and various hepatic microsomal parameters were measured. After 150 mg/kg of PBBs, cytochrome P450 concentrations reached a maximum by 48 hr (225% of control), then remained elevated through 336 hr. A similar pattern of induction was observed for epoxide hydratase and aniline hydroxylase activities. In c…
Acute exercise induced changes in rat skeletal muscle mRNAs and proteins regulating type IV collagen content
2001
This experiment tested the hypothesis that running-induced damage to rat skeletal muscle causes changes in synthesis and degradation of basement membrane type IV collagen and to proteins regulating its degradation. Samples from soleus muscle and red and white parts of quadriceps femoris muscle (MQF) were collected 6 h or 1, 2, 4, or 7 days after downhill running. Increased muscle β-glucuronidase activity indicated greater muscle damage in the red part of MQF than in the white part of MQF or soleus. In the red part of MQF, type IV collagen expression was upregulated at the pretranslational level and the protein concentration decreased, whereas matrix metalloproteinase-2 (MMP-2), a protein th…
How should we determine length of anticoagulation after proximal deep vein thrombosis of the lower limbs?
2009
The current approach for deciding the duration of vitamin K antagonist (VKA) treatment after an episode of venous thrombo-embolism (VTE) is mainly based on the characteristic of the index event (3 months or longer in case of unknown/persistent risk factors, 3 months or less in case of removable causes). However, the length of anticoagulation should be tailored on the patient's risk for recurrent thrombosis as well as for bleeding, but such 'time for decision' is often unclear and the optimal duration of VKA remains debatable. The presence of persistent residual vein thrombosis and increased D-dimer levels after stopping therapy are predictors for recurrent deep vein thrombosis (DVT). Manage…
Hormonal adaptations and modelled responses in elite weightlifters during 6 weeks of training.
1992
The concentrations of serum testosterone, sex-hormone-binding-globulin (SHBG) and luteinizing hormone (LH) were examined throughout 1-year of training in six elite weightlifters. A systems model, providing an estimation of fatigue and fitness, was applied to records of training volume and performance levels in clean and jerk. The analysis focused on a 6-week training period during which blood samples were taken at 2-week intervals. A 4-week period of intensive training (period I) could be distinguished from the following 2-week period of reduced training (period II). During period I, decreases in serum testosterone (P less than 0.05) and increases in serum LH concentrations (P less than 0.0…
What is Best Practice for Training Intensity and Duration Distribution in Endurance Athletes?
2010
Successful endurance training involves the manipulation of training intensity, duration, and frequency, with the implicit goals of maximizing performance, minimizing risk of negative training outcomes, and timing peak fitness and performances to be achieved when they matter most. Numerous descriptive studies of the training characteristics of nationally or internationally competitive endurance athletes training 10 to 13 times per week seem to converge on a typical intensity distribution in which about 80% of training sessions are performed at low intensity (2 mM blood lactate), with about 20% dominated by periods of high-intensity work, such as interval training at approx. 90% VO2max. Endur…