Search results for "Isoenzyme"
showing 10 items of 247 documents
Differential effects of sex hormones on peri- and endocortical bone surfaces in pubertal girls.
2005
Context: The role of sex steroids in bone growth in pubertal girls is not yet clear. Bone biomarkers are indicators of bone metabolic activity, but their value in predicting bone quality has not been studied in growing girls. Objective: This study examines the association of sex hormones and bone markers with bone geometry and density in pubertal girls. Design: The study was designed as a 2-yr longitudinal study in pubertal girls. Measurements were performed at baseline and at 1and 2-yr follow-ups. Setting: The study was conducted in a university laboratory. Participants: A total of 258 10- to 13-yr-old healthy girls at the baseline participated. Methods:Peripheralquantitativecomputedtomogr…
Role of GSH in the modulation of NOS-2 expression in the weaned mammary gland
2005
GSH delivery to the lactating mammary gland is essential for the maintenance of lactation as its decrease leads to apoptosis and involution of the mammary gland. In fact, it has already been demonstrated that some of the changes in gene expression found in the lactating mammary gland after forced weaning are reproduced in rats treated with buthionine sulphoximine to deplete GSH levels. An oligonucleotide microarray experiment would give us a better knowledge of the mRNA expression patterns during lactation and after weaning and the possible functions of GSH in the modulation of these events.
Muscle adenylate kinase in Duchenne muscular dystrophy
1986
Abstract On the basis of electrophoretic and enzyme inhibition studies it was postulated that an aberrant adenylate kinase occurs in muscle and serum of patients with Duchenne muscular dystrophy (Schirmer, R.H. and Thuma, E. (1972) Biochim. Biophys. Acta 268, 92–97; Hamada, M. et al. (1981) Biochim. Biophys. Acta 660, 227–237; Hamada et al. (1985) J. Biol. Chem. 260, 11595–11602. On the basis of the following results we conclude that Duchenne muscular dystrophy patients do not possess an unusual adenylate kinase isoenzyme. (1) In muscle biopsies from five Duchenne patients, the electrophoretic mobility of adenylate kinase and the inhibition of the enzyme by P 1 , P 5 -di(adenosine-5′)pentap…
Serum TRACP 5b Is a Useful Marker for Monitoring Alendronate Treatment: Comparison With Other Markers of Bone Turnover
2005
We studied clinical performance of serum TRACP 5b and other bone turnover markers, including S-CTX, U-DPD, S-PINP, S-BALP, and S-OC, for monitoring alendronate treatment. TRACP 5b had higher clinical sensitivity, area under the ROC curve, and signal-to-noise ratio than the other markers. INTRODUCTION: The purpose of this study was to compare the clinical performance of serum TRACP 5b (S-TRACP5b) with that of other markers of bone turnover in the monitoring of alendronate treatment. MATERIALS AND METHODS: This double-blinded study included 148 healthy postmenopausal women that were randomly assigned into two groups: one receiving 5 mg alendronate daily (n=75) and the other receiving placebo …
Tartrate-Resistant Acid Phosphatase 5b: A Novel Serum Marker of Bone Resorption
2000
Human serum contains two forms of tartrate-resistant acid phosphatase (TRAP), 5a and 5b. Of these, 5a contains sialic acid and 5b does not. We show here that antigenic properties and pH optimum of TRAP purified from human osteoclasts are identical to those of serum TRAP 5b and completely different from those of serum TRAP 5a, suggesting that 5b would be derived from osteoclasts and 5a from some other source. We developed a novel immunoassay specific for 5b using a monoclonal antibody O1A as capture antibody. O1A did not bind acid phosphatase derived from platelets and erythrocytes. Western analysis showed that O1A was specific for TRAP in both human bone and serum. We measured bound TRAP ac…
Expression of different isoforms of nitric oxide synthase in experimentally denervated and reinnervated skeletal muscle.
1997
Denervated muscle fibers express enhanced levels of stress and apoptosis-associated proteins and undergo apoptosis. In experimentally denervated and reinnervated rat facial muscle, we now evaluate changes in the expression patterns of different isoforms of nitric oxide synthase (NOS)-generating nitric oxide (NO), which mediates oxidative stress and apoptosis. Physiological expression of NOS corresponds to a constant sarcolemmal staining pattern for neuronal NOS (nNOS) and a patchy sarcolemmal and weak sarcoplasmic labeling for the endothelial NOS-isoform, with no expression for inducible NOS (iNOS). Denervated muscle displayed distinct downregulation of nNOS with preserved expression of dys…
Statin-Induced Liver Injury Involves Cross-Talk between Cholesterol and Selenoprotein Biosynthetic Pathways
2009
Statins have become the mainstay of hypercholesterolemia treatment. Despite a seemingly clear rationale behind their use, the inhibition of HMG-CoA reductase, these compounds have been shown to elicit a variety of unanticipated and elusive effects and side effects in vivo. Among the most frequently noted side effects of statin treatment are elevations in liver enzymes. Here, we report our finding that atorvastatin, cerivastatin, and lovastatin at clinically common concentrations induce a selective, differential loss of selenoprotein expression in cultured human HepG2 hepatocytes. The primarily affected selenoprotein was glutathione peroxidase (GPx), whose biosynthesis, steady-state expressi…
Effects of enzyme replacement therapy with agalsidase alfa on glomerular filtration rate in patients with Fabry disease: preliminary data
2007
Progressive deposition of globotriaosylceramide results in severe complications involving the kidney, heart and brain in both hemizygous male and heterozygous female patients with Fabry disease. Analysis of renal data from FOS - the Fabry Outcome Survey - suggests that enzyme replacement therapy with agalsidase alfa can significantly improve renal function in patients with Fabry disease, at least in those with a mild decrease in glomerular filtration rate, and may also be able to slow down the natural decline in renal function in patients with a moderate reduction in glomerular filtration rate. Conclusion: Initial results from the large cohort of patients within FOS indicate that treatment …
Characterization of nitric oxide synthase isoforms expressed in different structures of the guinea pig cochlea.
1997
Nitric oxide synthase (NOS) activity and NADPH diaphorase staining has previously been reported in mammalian cochlea. Here we demonstrate immunoreactivity for neuronal-type NOS I and endothelial-type NOS III in the cochlea of the guinea pig. NOS I immunoreactivity was seen in inner and outer hair cells, and spiral ganglion cells. Staining for NOS I was also shown in basal and intermediate cells of the stria vascularis, spiral ligament cells, and the media of vessels near the modiolus. An antibody to NOS III stained primarily vascular endothelial cells. Some NOS III immunoreactivity was also detected in spiral ganglion cells. An antibody to the inducible-type NOS II did not stain any structu…
Nitric oxide synthases: regulation and function
2011
Nitric oxide (NO), the smallest signalling molecule known, is produced by three isoforms of NO synthase (NOS; EC 1.14.13.39). They all utilize l-arginine and molecular oxygen as substrates and require the cofactors reduced nicotinamide-adenine-dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), and (6R-)5,6,7,8-tetrahydrobiopterin (BH(4)). All NOS bind calmodulin and contain haem. Neuronal NOS (nNOS, NOS I) is constitutively expressed in central and peripheral neurons and some other cell types. Its functions include synaptic plasticity in the central nervous system (CNS), central regulation of blood pressure, smooth muscle relaxation, and vasodila…