1. This study was conducted to determine the effects of heat stress on fearfulness, leucocyte components, oxidative stress and lipid peroxidation in two commercial broiler strains, Cobb (C) and Ross ...(R). 2. At 36 and 37 d of age birds were exposed to 38 ± 1°C for 3 h. Rectal temperatures, duration of tonic immobility (TI), haematocrit values, proportions of leucocyte components (heterophil, lymphocyte, basophil, eosinophil, monocyte), malondialdehyde (MDA) concentrations and antioxidant enzyme activities (CAT, SOD, GPx) of all the birds were determined, before and after heat treatment. 3. Rectal temperatures increased and haematocrit values decreased in birds exposed to heat stress. Heat stress caused a significant increase in heterophil/lymphocyte and in basophil ratios. 4. Exposing birds to heat stress increased duration of TI, suggesting heat-stressed birds tended to be more fearful. 5. Heat stress resulted in a significant Genotype × Treatment interaction for MDA concentration. CAT, SOD and GPx activities; MDA concentrations in heat-stressed R strain birds were greater than in heat-stressed C strain birds.
The ethanol and methanol extracts of
Arbutus unedo leaves were screened for antioxidant activity. The antioxidant activity was determined by an improved assay based on the decolorization of the ...radical monocation of 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS
+
). The ethanol and methanol extract of
A. unedo leaves displayed potent antioxidant activity.
1. This study was conducted to determine metabolic and physiological responses of 2 commercial broiler strains, Hubbard (H) and Cobb (C), exposed to an ambient temperature of 38°±1°C for 2 h at 14 ...and 15 d of age. 2. Exposure to high temperature at an early age resulted in weight loss in strain C, which was not compensated for by 35 d of age but there was no weight loss in strain H. 3. Exposure of broilers to heat stress (38°±1°C) at 35 d of age resulted in an increase in rectal temperature, regardless of previously high temperature experience but acid-base balance and haematocrit values were not affected by heat stress. 4. Malondialdehyde concentration was higher in unexposed birds than in previously exposed ones and did not significantly differ between strains.
BACKGROUNDBiotinidase is the enzyme responsible for liberating the vitamin biotin from biocytin and dietary protein–bound vitamin. Individuals lacking biotinidase activity become biotin deficient. ...Because the liver is the major source of plasma biotinidase, chronic liver diseases can lead to decreased serum biotinidase activity and biotin deficiency. The aim of this study is to determine serum biotinidase activity values in children with chronic liver disease and to investigate the relation among enzyme activity, certain liver function tests, and degree of liver damage.
METHODIn this study, using a spectrophotometric method, biotinidase activity was determined in sera from 62 children with chronic liver diseases (median age, 9.73 years; range, 8 months to 18 years) and from 27 healthy controls. Diagnoses of the patient group were as followsnoncirrhotic chronic hepatitis B virus infection (n = 12), metabolic liver diseases (n = 16), autoimmune hepatitis (n = 6), intrahepatic and extrahepatic cholestasis (n = 14), fulminant hepatitis (n = 5), cryptogenic cirrhosis n = 5), prehepatic portal hypertension (n = 4). Meanwhile, serum albumin, total bilirubin, alkaline phosphatase, alanine aminotransferase, and γ-glutamyltransferase concentrations and prothrombine time were determined for each patient and the results were correlated with serum biotinidase activity.
RESULTSThere was significant difference between mean enzyme activity of the controls (7.6 ± 1.2 nmol · min · mL ) and of all patients with chronic liver disease (6.3 ± 2.5 nmol · min · mL ) (P < 0.05). Serum biotinidase activity in patients with noncirrhotic chronic liver diseases (chronic viral hepatitis, prehepatic portal hypertension, glycogen storage disease, Gaucher disease) was within the normal ranges. However, serum biotinidase activity in patients with cirrhosis and Wilson disease was significantly less than that of the control group (P < 0.05). The lowest enzyme activities were detected in patients with fulminant hepatitis.
CONCLUSIONIn this study, serum biotinidase activity was significantly lower in patients with cirrhosis, particularly in the patients with decompensated cirrhosis and fulminant hepatitis who exhibited no clinical symptoms related to biotin deficiency. The decreased serum biotinidase activity in chronic liver diseases was associated with severe impairment of hepatocellular function.
Oxidative modification of low-density lipoproteins (LDL) contributes to the pathology of atherosclerosis. Antioxidants may protect LDL against oxidative modification. Acetaminophen, a widely used ...analgesic and antipyretic agent, has significant antioxidant properties. However, there is little evidence to suggest that acetaminophen acts as an antioxidant for LDL oxidation in vivo. In this study, we investigated the in vivo effect of acetaminophen on LDL oxidation in hypercholesterolemic rabbits. The oxidative modification of LDL was identified by conjugated dienes and thiobarbituric acid-reactive substances (TBARS). In the cholesterol group which rabbits were fed a diet contained 1% g cholesterol for 8 weeks, TBARS contents and conjugated diene levels in the plasma and isolated LDL samples significantly increased compared with the control rabbits (p<0.05). However, in the cholesterol + acetaminophen group, the TBARS contents and conjugated diene levels were significantly lower than that of the cholesterol group (p<0.05). The results from in vitro studies also demonstrated that the LDL isolated from serum was oxidized by Cu++ ions and this oxidation reduced in the presence of acetaminophen. The reduced oxidative modification of LDL by acetaminophen may be of therapeutic value in preventing the development and progression of atherosclerosis.
Myeloperoxidase (MPO), a heme protein expressed by polymorphonuclear leukocytes, generates potent oxidants which are proposed to contribute to tissue damage during inflammation and certain ...pathogenesis such as neurodegenerative disorders. In this study, twenty ω‐2‐oxo‐3H‐benzoxazol‐3‐yl‐N‐phenylacetamide and propionamide derivatives having substituents of different lipophilic and electronic nature on the N‐phenyl ring were synthesized to evaluate the inhibitory effects on in vitro leukocyte MPO chlorinating activity. The most active compounds in the series were the derivatives bearing 2‐methyl and 4‐nitro substituent on the N‐phenyl ring.
Myeloperoxidase (MPO) is a major component of the antimicrobial system of polymorphonuclear neutrophils. The heme enzyme MPO catalyzes the conversion of hydrogen peroxide and chloride to hypochlorous ...acid. Hypochlorous acid is the major strong oxidant produced by neutrophils and may contribute to inflammatory tissue damage. It was reported that certain antiinflammatory drugs are capable of inhibiting MPO activity and this inhibition may account for their antiinflammatory effect.
Hypericum L. is a genus of about 400 species, widespread throughout the world. Some species of genus exhibit a significant antiinflammatory activity beside their several pharmacological properties such as antidepressant, diuretic, antihelmintic, and antibacterial. In this study, we investigated the in vitro effects of three
Hypericum species, which exhibit antiinflammatory activity, on human polymorphonuclear leukocyte MPO activity. We found that each extract of
Hypericum species reduced the peroxidative and chlorinating activity of human leukocyte MPO in concentration-dependent manner. The antiinflammatory activity of these species may be related with inhibition of MPO activity.
In this study the activity of a membrane-bound enzyme, gamma-glutamyl transferase GGT (gamma-glutamyl transpeptidase - GGTP), was investigated in the peripheral blood lymphocytes (PBL) from patients ...with Behçet's disease. Lymphocyte GGT activity in Behçet's disease was found to be significantly lower than that of control lymphocytes (p less than 0.01). This altered activity may be due to the abnormality in the membrane of lymphocytes of Behçet's disease patients.
An amperometric biosensor based on a carbon paste electrode modified with horseradish peroxidase (HRP) is defined as a device for the quantitative and qualitative detection of oxidizable drugs. This ...paper demonstrates the advantages of using HRP as the biocatalyst in the in vitro detection of oxidizable drugs in the presence of hydrogen peroxide. Amperometric analysis and batch experiments were carried out in acetate buffer (pH 4.8) in the presence of hydrogen peroxide. Amperometry was performed by applying a potential of -0.1 V (vs. Ag/AgCl), in the presence of hydrogen peroxide and adding a drug which has an oxidizable group (OxG; e.g. -OH, -NH, -SH). The results show that the HRP-modified electrode responds rapidly to micromolar changes in the OxG addition. The current signals obtained are proportional to the OxG concentration. Experimental variables, such as pH, operating potential, change in the percentage of HRP, and reproducibility are discussed. The stability of the HRP-modified electrode is also demonstrated.
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