307 research outputs found

    Effects of stress produced by adrenocorticotropin (ACTH) on lipid peroxidation and some antioxidants in vitamin C treated and nontreated chickens

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    The aim of this study was to examine the effects of vitamin C on malonaldehyde (MDA) and glutathione (GSH) concentrations, and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity in chickens stressed by adrenocorticotropin (ACTH). Sixty Leghorn chickens (20 weeks old) were randomly allotted to a control and a vitamin C treated group. An isotonic sodium chloride solution was administrated intramuscularly for a period of five days to the control group at a dose of 2.5 mL per chicken per day, and the treatment group received a vitamin C solution (containing 250 mg vitamin C/2.5 mL) intramuscularly for five days. On the fifth day of the experiment the chickens in both groups received 50 IU ACTH intramuscularly. Three hours after ACTH application blood samples were collected to determine the concentrations of MDA and GSH, and activities of SOD and GSH-Px in the blood. The concentration of MDA in the control group increased compared to that in the vitamin C treated group. After the ACTH application the activity of SOD increased in both groups, thought significantly so in the vitamin C treated group. The GSH-Px activity did not differ significantly between the treatments after ACTH application. It was concluded that intramuscularly administrated vitamin C facilitated an adaptation against stress and decreased negative effects of stress in chickens. Keywords: ACTH, glutathione (GSH), Glutathione peroxidase (GSH-Px), Malonaldehyde (MDA), Superoxide dismutase (SOD), Vitamin C South African Journal of Animal Science Vol.33(3) 2003: 201-20

    Effect of Nigella sativa L. on heart rate and some haematological values of alloxan-induced diabetic rabbits

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    This study was designed to investigate the effect of an extract of Nigella sativa L. on the heart rate and  some haematological values in alloxan-induced diabetic rabbits. Fifteen New Zealand male rabbits were  divided into three experimental groups: control, diabetic and N. sativa L.-treated diabetic. At the end of the  experimental period (2 months), animals in all three groups were fasted for 12 hours and blood samples  were taken for the determination of glucose levels, RBC and WBC (red and white blood cell) counts,  packed cell volume (PCV), and haemoglobin (Hb) concentration. Heart rates were also measured by a  direct-writing electrocardiograph before the blood withdrawals. It was found that N. sativa L. treatment  increased the lowered RBC and WBC counts, PCV and neutrophil percentage in diabetic rabbits. However,  the WBC count of the N. sativa L. treated diabetic group was still lower than the control. N. sativa L.  treatment also decreased the elevated heart rate and glucose concentration of diabetic rabbits. It is concluded  that oral N. sativa L. treatment might decrease the diabetes-induced disturbances of heart rate and some  haematological parameters of alloxan-induced diabetic rabbits.

    The effects of exhaustive swimming and probiotic administration in trained rats: Oxidative balance of selected organs, colon morphology, and contractility

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    The duration and intensity of exercise are significant factors in oxidative, morphological, and functional changes of the gastrointestinal tract. This study aimed to investigate the effects of both exhaustive swimming and probiotic VSL#3 on rats that had been previously trained with moderate swimming. The rats were divided into four groups labeled: control (C), probiotic (P), exercise (E), and probiotic–exercise (PE). Groups P and PE were fed with probiotic mixture VSL#3. Groups E and PE had a 5-week moderate swimming program (1 h/day for 5 days/week), followed by a 1-week exhaustive swimming program (trained like in moderate program but 3 times with 150 min resting sessions, for 5 days/week). At the end of the program, the rats were euthanized. Malondialdehyde, superoxide dismutase, catalase, and reduced glutathione levels were measured in tissue samples from the gastrocnemius muscle, heart, liver, kidney, and colon. In vitro contractile activity and histomorphology of the colon were also determined. Exercise and/or probiotic decreased the oxidative stress and also increased the level of one or more of the antioxidant enzymes in some of the organs. Probiotics had more pronounced effects on colon morphology than exercise but unexpectedly this effect was non-trophic. In the colon, the thickness of the tunica muscularis and the number of goblet cells were not affected; however, probiotic administration decreased the crypt depth and tunica mucosa thickness. Exercise increased the Emax value of acetylcholine (ACh), while decreased its sensitivity. These findings suggest that exhaustive swimming does not cause oxidative stress and that probiotic consumption improves oxidative balance in trained rats. The probiotic intake does not alter the effect of exercise on the contractile activity of the colon. Colon mucosal changes induced by probiotics are independent of exercise

    The effects of swimming exercise and probiotic vsl#3 on zonulin and some inflammatory and oxidative parameters in rats

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    Moderate exercise stimulates immune system whereas intensive exercise may display immune-suppressive effect associated with the disruption of intestinal barrier. With this study, we tested the effects of moderate and intensive swimming exercises on some cytokines and oxidant variables and zonulin, an intestinal barrier marker, in rats. We also tested possible ameliorative effects of probiotic VSL#3 in both moderate and intensive exercise regimens. Twenty eight rats were randomly divided into 4 equal groups: Control-C, Probiotic-P, Exercise-E, Probiotic+Exercise-PE. The rats in group E and PE underwent moderate swimming exercise for 5 weeks. Following this period, intensive swimming exercise was performed for 5 days. The rats in group C and group P were sedentary. Probiotic VSL#3 was given to group P and PE in the water. At the end of the experiments, serum zonulin, TNF-α, IL-6, IL-10, TGF-β, MDA, and protein carbonyl levels were determined. Evidences obtained from present study indicate that moderate swimming exercise improves barrier integrity of intestine and decreases oxidative stress. During the moderate swimming experiment, probiotic VSL#3 supplementation may also improve inflammatory response. On the other hand, intensive exercise does not led changes in the inflammatory response and oxidative stress, but beneficial responses of moderate exercise on the selected parameters probably disappear due to the intense exercise-induced mild stress

    Effective null Raychaudhuri equation

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    The effects on Raychaudhuri's equation of an intrinsically-discrete or particle nature of spacetime are investigated. This is done through the consideration of null congruences emerging from, or converging to, a generic point of spacetime, i.e. in geometric circumstances somehow prototypical of singularity issues. We do this from an effective point of view, that is through a (continuous) description of spacetime modified to embody the existence of an intrinsic discreteness on the small scale, this adding to previous results for non-null congruences. Various expressions for the effective rate of change of expansion are derived. They in particular provide finite values for the limiting effective expansion and its rate of variation when approaching the focal point. Further, this results in a non-vanishing of the limiting cross-sectional area itself of the congruence.Comment: 7 pages; v2: some comparisons with other approaches adde

    Decrease in thyroid adenoma associated (THADA) expression is a marker of dedifferentiation of thyroid tissue

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    <p>Abstract</p> <p>Background</p> <p><it>Thyroid adenoma associated (THADA) </it>has been identified as the target gene affected by chromosome 2p21 translocations in thyroid adenomas, but the role of THADA in the thyroid is still elusive. The aim of this study was to quantify <it>THADA </it>gene expression in normal tissues and in thyroid hyper- and neoplasias, using real-time PCR.</p> <p>Methods</p> <p>For the analysis <it>THADA </it>and 18S rRNA gene expression assays were performed on 34 normal tissue samples, including thyroid, salivary gland, heart, endometrium, myometrium, lung, blood, and adipose tissue as well as on 85 thyroid hyper- and neoplasias, including three adenomas with a 2p21 translocation. In addition, <it>NIS </it>(<it>sodium-iodide symporter</it>) gene expression was measured on 34 of the pathological thyroid samples.</p> <p>Results</p> <p>Results illustrated that <it>THADA </it>expression in normal thyroid tissue was significantly higher (<it>p </it>< 0.0001, exact Wilcoxon test) than in the other tissues. Significant differences were also found between non-malignant pathological thyroid samples (goiters and adenomas) and malignant tumors (<it>p </it>< 0.001, Wilcoxon test, t approximation), anaplastic carcinomas (ATCs) and all other samples and also between ATCs and all other malignant tumors (<it>p </it>< 0.05, Wilcoxon test, t approximation). Furthermore, in thyroid tumors <it>THADA </it>mRNA expression was found to be inversely correlated with <it>HMGA2 </it>mRNA. <it>HMGA2 </it>expression was recently identified as a marker revealing malignant transformation of thyroid follicular tumors. A correlation between <it>THADA </it>and <it>NIS </it>has also been found in thyroid normal tissue and malignant tumors.</p> <p>Conclusions</p> <p>The results suggest <it>THADA </it>being a marker of dedifferentiation of thyroid tissue.</p

    Identification and Validation Model for Informative Liquid Biopsy-Based microRNA Biomarkers:Insights from Germ Cell Tumor In Vitro, In Vivo and Patient-Derived Data

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    Liquid biopsy-based biomarkers, such as microRNAs, represent valuable tools for patient management, but often do not make it to integration in the clinic. We aim to explore issues impeding this transition, in the setting of germ cell tumors, for which novel biomarkers are needed. We describe a model for identifying and validating clinically relevant microRNAs for germ cell tumor patients, using both in vitro, in vivo (mouse model) and patient-derived data. Initial wide screening of candidate microRNAs is performed, followed by targeted profiling of potentially relevant biomarkers. We demonstrate the relevance of appropriate (negative) controls, experimental conditions (proliferation), and issues related to sample origin (serum, plasma, cerebral spinal fluid) and pre-analytical variables (hemolysis, contaminants, temperature), all of which could interfere with liquid biopsy-based studies and their conclusions. Finally, we show the value of our identification model in a specific scenario, contradicting the presumed role of miR-375 as marker of teratoma histology in liquid biopsy setting. Our findings indicate other putative microRNAs (miR-885-5p, miR-448 and miR-197-3p) fulfilling this clinical need. The identification model is informative to identify the best candidate microRNAs to pursue in a clinical setting
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