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141.
The protective effects of melatonin, vitamin E, and selenium alone or in combination were tested against cadmium-induced oxidative
damage in rat testes. A total of 60 male rats were equally divided into five study groups, one of which acted as control receiving
subcutaneous injections of physiological saline. The remaining four groups were treated with subcutaneous injections of cadmium
chloride at a dose of 1 mg/kg weight. The first study group received no treatment. The second group was treated with a combination
of 60 mg/kg vitamin E and 1 mg/kg sodium selenite. Group 3 was treated with 10 mg/kg melatonin, and the fourth group received
a combination of vitamin E, sodium selenite, and melatonin at the doses mentioned above. After 1 month, the animals were killed,
and the testes were excised for histological inspection and determination of tissue malondialdehyde and the activity of superoxide
dismutase. The animals receiving no treatment showed significantly higher malondialdehyde levels and reduced activity of the
enzyme (p < 0.05). Treatment with antioxidants resulted in a significant reduction in malondialdehyde when compared to the nontreated
animals (p < 0.05) and an increase in the superoxide dismutase activity that was almost the same as the controls. The combination of
melatonin, vitamin E, and selenium appears to have the more profound effect against cadmium-induced testicular injury. 相似文献
142.
The present study was carried to evaluate the protective effects of melatonin alone and vitamin E with selenium combination
against high dose cadmium-induced oxidative stress in rats. The control group received subcutanous physiological saline. The
first study group administered cadmium chloride (CdCl2) by subcutaneous injection of dose of 1 mg/kg. The second study group administered cadmium plus vitamin E with selenium (1 mg/kg
sodium selenite with 60 mg/kg vitamin E); the third study group administered cadmium plus 10 mg/kg melatonin (MLT); the fourth
study group administered CdCl2 plus a combination of melatonin in addition to vitamin E and selenium for a month. Determination levels of plasma malondialdehyde
(MDA), glutathione peroxidase (GSH-Px), blood superoxide dismutase (SOD), creatinine alanine transaminase (ALT), aspartate
aminotransferase (AST), alkaline phosphatase (ALP), blood urea nitrogen (BUN), and urea were measured in serum. In only CdCl2 administered group, the MDA, creatinine, ALT, AST, ALP, and urea levels in the serum were significantly higher than the control
group (p < 0.05). Whereas in all other groups, this values were significantly lower than the only CdCl2 administered group (p < 0.05). Erythrocytes GSH-Px, serum SOD activities of only CdCl2 received group were significantly lower than the control group (p < 0.05). In conclusion, vitamin E + Se, melatonin and vitamin E, and Se, in addition to MLT combinations, had protective
effects against high dose cadmium-induced oxidative damage. 相似文献
143.
Ultrastructural changes in the kidneys of rats after acute cadmium exposure and the effects of exogenous metallothionein (MT)
were studied by transmission electron microscopy. Thirty-six adult Wistar rats were divided into three groups. Cadmium chloride
(CdCl2) (3.5 mg/kg/day) was injected subcutaneously in the first group. In the second group, 30 μmol/kg MT was administered in addition
to CdCl2. Control rats received 0.5 ml subcutaneous saline solution. Four rats from each group were killed on days 1, 3, 5, and 7
after administration of the compounds. Kidney tissues were taken and fixed in 2.5% glutaraldehyde solution for electron microscopic
observations. Tissue damage in kidney increased as time passed since the administration of CdCl2 in the first group. Degeneration in the proximal and distal tubules was observed. Increased apoptosis was seen in the proximal
tubules epithelium, especially on day 7. Peritubular capillaries became dilated, there was degeneration of the endothelial
cells, and the amount of intertubular collagen fibers was increased. On day 1, irregular microvilli in the proximal tubules,
deepening of the basal striations, and myelin figures; on day 3, multiple vesicular mitochondria and regions of edema around
tubules; on days 5 and 7, increased apoptotic cell in the proximal tubules and widened rough endoplasmic reticulum of the
endothelial cells of glomerular capillaries were observed. We observed that the structural alterations that increased depending
on the day of Cd administration decreased after exogenous MT administration, the dilation of the peritubular capillaries persisted,
and there were degenerated proximal tubules. It was established that cadmium chloride was toxic for kidney cortex and caused
structural damage. Exogenous MT partly prevents CdCl2-induced damage. 相似文献
144.
Hypoxia-ischemia with reperfusion is known to cause reactive oxygen species-related damage in mammalian systems, yet, the anoxia tolerant freshwater turtle is able to survive repeated bouts of anoxia/reoxygenation without apparent damage. Although the physiology of anoxia tolerance has been much studied, the adaptations that permit survival of reoxygenation stress have been largely ignored. In this study, we examine ROS production in the turtle striatum and in primary neuronal cultures, and examine the effects of adenosine (AD) on cell survival and ROS. Hydroxyl radical formation was measured by the conversion of salicylate to 2,3-dihydroxybenzoic acid (2,3-DHBA) using microdialysis; reoxygenation after 1 or 4 h anoxia did not result in increased ROS production compared with basal normoxic levels, nor did H2 O2 increase after anoxia/reoxygenation in neuronally enriched cell cultures. Blockade of AD receptors increased both ROS production and cell death in vitro , while AD agonists decreased cell death and ROS. As turtle neurons proved surprisingly susceptible to externally imposed ROS stress (H2 O2 ), we propose that the suppression of ROS formation, coupled to high antioxidant levels, is necessary for reoxygenation survival. As an evolutionarily selected adaptation, the ability to suppress ROS formation could prove an interesting path to investigate new therapeutic targets in mammals. 相似文献
145.
146.
Isolation and characterization of replication-competent human immunodeficiency virus type 1 from a subset of elite suppressors
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Blankson JN Bailey JR Thayil S Yang HC Lassen K Lai J Gandhi SK Siliciano JD Williams TM Siliciano RF 《Journal of virology》2007,81(5):2508-2518
Elite suppressors (ES) are untreated human immunodeficiency virus type 1 (HIV-1)-infected individuals who control viremia to levels below the limit of detection of current assays. The mechanisms involved in this control have not been fully elucidated. Several studies have demonstrated that some ES are infected with defective viruses, but it remains unclear whether others are infected with replication-competent HIV-1. To answer this question, we used a sensitive coculture assay in an attempt to isolate replication-competent virus from a cohort of 10 ES. We successfully cultured six replication-competent isolates from 4 of the 10 ES. The frequency of latently infected cells in these patients was more than a log lower than that seen in patients on highly active antiretroviral therapy with undetectable viral loads. Full-length sequencing of all six isolates revealed no large deletions in any of the genes. A few mutations and small insertions and deletions were found in some isolates, but phenotypic analysis of the affected genes suggested that their function remained intact. Furthermore, all six isolates replicated as well as standard laboratory strains in vitro. The results suggest that some ES are infected with HIV-1 isolates that are fully replication competent and that long-term immunologic control of replication-competent HIV-1 is possible. 相似文献
147.
148.
Egbertson MS Moritz HM Melamed JY Han W Perlow DS Kuo MS Embrey M Vacca JP Zrada MM Cortes AR Wallace A Leonard Y Hazuda DJ Miller MD Felock PJ Stillmock KA Witmer MV Schleif W Gabryelski LJ Moyer G Ellis JD Jin L Xu W Braun MP Kassahun K Tsou NN Young SD 《Bioorganic & medicinal chemistry letters》2007,17(5):1392-1398
A 1,6-naphthyridine inhibitor of HIV-1 integrase has been discovered with excellent inhibitory activity in cells, good pharmacokinetics, and an excellent ability to inhibit virus with mutant enzyme. 相似文献
149.
Stiver KA Desjardins JK Fitzpatrick JL Neff B Quinn JS Balshine S 《Molecular ecology》2007,16(14):2974-2984
African Great Lake cichlid populations are divided into thousands of genetic subpopulations. The low gene flow between these subpopulations is thought to result from high degrees of natal philopatry, heavy predation pressure, and a patchy distribution of preferred habitats. While predation pressure and habitat distribution are fairly straightforward to assess, data on dispersal distances and rates are scarce. In fishes, direct observations of dispersal events are unlikely, but dispersal can be studied using molecular markers. Using seven microsatellite loci, we examined dispersal in the cooperatively breeding cichlid fish, Neolamprologus pulcher. As this species is found in well-defined groups clustered into subpopulations, we could assess dispersal on a narrow (within subpopulation) and broad (between subpopulation) scale. While fish were generally more related to others in their own subpopulation than they were to fish from other subpopulations, large males diverged from this pattern. Large males were more related to other large males from different subpopulations than they were to large males from their own subpopulation, suggesting more frequent dispersal by large males. Across subpopulations, relatedness between large males was higher than the relatedness among large females; this pattern was not detected in small males and small females. Within a subpopulation, individuals appeared to be preferentially moving away from relatives, and movement was unrestricted by the physical distance between groups. Our results highlight the importance of examining multiple spatial scales when studying individual dispersal biases. 相似文献
150.
Karaś M 《Protein and peptide letters》2007,14(5):447-454
In this study, peptides and proteins extracted from string bean with 1% TCA were separated by chromatography on columns with copper ions immobilized through IDA and o-phosphoserine OPS. Protein and peptide concentrations and the anti-free-radical properties of the isolated fractions were determined. Identification was obtained using mass spectrometry. The anti-free- radical activity of all analyzed samples was determined using the DPPH test, and was found to depend on reaction time, choice of chelating agent and the order in which the fractions were eluted from the column. 相似文献