Arginase activity and lecithin/sphingomyelin (l/s) ratio in the amniotic fluid of pregnant women.

Arginase activity is important in polyamines and nitric oxide production which are required for the normal growth of placenta and embryo. A considerable arginase activity is observed in amniotic fluid in women at the end of pregnancy. Lecithin to sphingomyelin (L/S) ratio is widely used in order to assess fetal lung immaturity and prevention of neonatal respiratory distress syndrome, the major cause of neonatal morbidity and mortality.

Dexamethasone decreases the spermidine and spermine concentrations and polyamine oxidase activity in rat thymus.

Background: Glucocorticoids (GCs) exert a wide range of anti-inflammatory, immunosuppressive, and antineoplastic activities. The aim of our investigation was to elucidate the effect of dexamethasone, a synthetic GC, on polyamine metabolism in the rat thymus.

Methods: Male albino Wistar rats, weighing 180-230 g, were divided into two groups: control and experimental.

Arginase activity in human milk during the first month of lactation.

Arginase (L-arginine amidinohydrolase, EC 3.5.3.

Thymus as a target tissue of glucocorticoid action: what are the consequences of glucocorticoids thymectomy?

Glucocorticoids represent the most powerful endogenous anti-inflammatory and immunosuppressive effectors, interfering with virtually every step of immunoinflammatory responses. Glucocorticoids are often the most effective therapy in the prevention or suppression of inflammation and other immunologically mediated processes, but their use is limited by systemic side effects induced by the over-production of reactive oxygen species, causing dysregulation of physiological processes. The thymus is an organ with both endocrine and immune functions.

Effect of L-arginine on metabolism of polyamines in rat's brain with extrahepatic cholestasis.

Cholestatic encephalopathy results from accumulation of unconjugated bilirubin and hydrophobic bile acids in the brain. The aim of this study was to determine disturbances of polyamine metabolism in the brains of rats with experimental extrahepatic cholestasis and the effects of L-arginine administration. Wister rats were divided into groups: I: sham-operated, II: rats treated with L-arginine, III: animals with bile-duct ligation (BDL), and IV: cholestatic-BDL rats treated with L-arginine.

Polyamine oxidase activity in peripheral blood of newborn infants with neonatal hyperbilirubinemia: is bilirubin an antioxidant?

Background: Neonatal hyperbilirubinemia can be physiological and pathological and most frequently is a consequence of faster erythrocytes (RBC) hemolysis. Free unconjugated bilirubin is a highly toxic compound, especially for the central nervous system. The most abundant polyamines circulating in blood are spermidine (Spd) and spermine (Sp), which are mainly localized in RBC, where they control membrane permeability.

Melatonin reduces oxidative stress induced by chronic exposure of microwave radiation from mobile phones in rat brain.

Purpose: The aim of the study was to evaluate the intensity of oxidative stress in the brain of animals chronically exposed to mobile phones and potential protective effects of melatonin in reducing oxidative stress and brain injury.

Materials And Methods: Experiments were performed on Wistar rats exposed to microwave radiation during 20, 40 and 60 days. Four groups were formed: I group (control)- animals treated by saline, intraperitoneally (i.

Protective effect of interferon-alpha on the DNA- and RNA-degrading pathway in anti-Fas-antibody induced apoptosis.

Aim: Fas membrane-associated polypeptide antigen is a receptor molecule responsible for apoptosis-mediated signals. In animal models of acute viral hepatitis, apoptosis of hepatocytes is mediated by Fas-death receptors; therefore, the aim of this study was to evaluate the effect of interferon (IFN)-alpha on apoptotic markers and nuclease activity against different coding and non-coding single and double stranded RNAs during Fas-induced liver apoptosis.

Methods: An in vivo experiment was performed with simultaneous administration of anti-Fas (CD95) antibodies and IFN-alpha, and an in vitro experiment was performed in hepatocyte cultures treated with anti-Fas antibodies and IFN-alpha.

Possible impact of plasma RNase activity on immune dysfunction in juvenile diabetes mellitus.

Aim: The ribonuclease (RNase) family represents important enzymes used widely in biomedical and biotechnological applications, as well as for diagnostic and therapeutic purposes. This study was undertaken to test the possibility that plasma alkaline RNase (free or inhibitory bound) determination may be useful in studying the dysregulation of nucleic acid and oligonucleotide metabolism as a possible pathogenetic mechanism in development of immune dysfunction in juvenile diabetes mellitus.

Patients And Methods: Children with type 1 diabetes (n=32, age group of 5--14 yr), together with age-matched control subjects (n=35), were enrolled in the study.

Effect of caffeine on metabolism of L-arginine in the brain.

Methylxanthines are widely consumed because of their stimulating effect primarily on the central nervous system. Their diuretic and respiratory stimulant action is used in clinical medicine. L-Arginine metabolism in the brain is very important for normal brain function.