Beneficial effects of Salvia officinalis essential oil on vanadium-induced testicular injury,DNA damage and histological alterations in Wistar rats

BioMetals - Vanadium has been shown to catalyze the generation of reactive oxygen species. Since free radical production and lipid peroxidation are potentially important mediators in testicular...     

Life history,excystment features,and growth characteristics of the Mediterranean harmful dinoflagellate Alexandrium pseudogonyaulax

Studies considering the biology and ecology of the toxic bloom‐forming species, Alexandrium pseudogonyaulax, are rare. Our results highlight five features not described before in A. pseudogonyaulax life cycle: (i) A. pseudogonyaulax gametes showed two modes of conjugation, anisogamy and isogamy, (ii) sexual conjugation occurs either in the dark or in the light phase by engulfment or a fusion process, (iii) the presence of planozygote and newly formed cysts in monoclonal culture suggests homothallism, (iv) newly formed cysts have very dark vesicular content and are mostly unparatabulated when observed under light microscope and (v) natural resting cysts are able to give either a planomeiocyte or two vegetative cells. Cyst viability was enhanced after 5 months of cold storage (4°C), with excystment rate reaching 97% after 3 d of incubation. Excystment rate was highest (43%–79%) in Enriched Natural Sea Water diluted culture medium, whereas few germling cells were able to survive without the culture medium (0%–13%). Salinity‐irradiance experiments revealed that the highest cell concentrations occur at high irradiances for all the tested salinities. Vegetative growth rates generally increased with increasing irradiance, and were less dependent on salinity variations. The relatively low growth rate, low cell densities in the laboratory, and the notable capacity of producing cysts along growth phases of A. pseudogonyaulax could explain the occurrence of high resting cysts densities in the sediment of Bizerte lagoon and the relatively low abundances of vegetative cells in the water column.     

Ameliorating effect of selenium on chromium (VI)-induced oxidative damage in the brain of adult rats

Chromium is known for its wide toxic manifestations. This experiment aims to evaluate the effect of selenium against oxidative stress induced by chromium in the cerebrum and cerebellum. Female Wistar rats were randomly divided into four groups of six each: group I served as controls which received the standard diet; group II received drinking water K(2)Cr(2)O(7) alone (700 ppm); group III received both K(2)Cr(2)O(7) and Se (0.5 mg Na(2)SeO(3)/kg of diet); and group IV received Se (0.5 mg/kg of diet) for 3 weeks. The exposure of rats to K(2)Cr(2)O(7) promoted oxidative stress in the cerebrum and cerebellum with an increase in malondialdehyde and a decrease of nonenzymatic antioxidant levels such as glutathione, nonprotein thiol, and vitamin C. An increase of enzyme activities like catalase, glutathione peroxidase, and superoxide dismutase activities was also observed. Acetylcholinesterase activity was inhibited after treatment with K(2)Cr(2)O(7). Co-administration of Se restored the parameters cited above. The histopathological findings confirmed the biochemical results.     

A computational model of visual anisotropy

Visual anisotropy has been demonstrated in multiple tasks where performance differs between vertical, horizontal, and oblique orientations of the stimuli. We explain some principles of visual anisotropy by anisotropic smoothing, which is based on a variation on Koenderink's approach in [1]. We tested the theory by presenting gaussian elongated luminance profiles and measuring the perceived orientations by means of an adjustment task. Our framework is based on the smoothing of the image with elliptical gaussian kernels and it correctly predicted an illusory orientation bias towards the vertical axis. We discuss the scope of the theory in the context of other anisotropies in perception.     

Skewed X-chromosome inactivation pattern in SRY positive XX maleness: a case report and review of literature

XX maleness is the most common condition in which testes develop in the absence of a cytogenetically detectable Y chromosome. Using fluorescence in situ hybridization (FISH) or PCR, it was possible to detect the transfer of Yp fragments including SRY gene to the terminal part of X chromosome in the majority of XX males. We report a 32-year-old-male in whom a seminal analysis showed azoospermia, an X chromatin analysis showed 44% of Barr body positive nuclei and a chromosomal analysis revealed a 46,XX karyotype. Physical examination showed a normal sexual development and bilateral small testes. Hormonal studies revealed hypergonadotropic hypogonadism. Testis histological examination showed a profile of Sertoli Only Cell Syndrome. FISH study ruled out the presence of a Y-bearing cell line, and confirmed translocation of SRY to Xp terminal part. In order to confirm that the complete masculinized phenotype was related to a preferential inactivation of the no rearranged X chromosome, X-chromosome inactivation patterns (XCIP) were studied by analysis of methylation status of the androgen receptor gene. Highly skewed XCIP was observed by greater than 90% preferential inactivation involving one of the two X chromosomes, suggesting that the SRY-bearing X chromosome was the preferentially active X allowing for sufficient SRY expression for complete masculinization.     

Improvement of Cerebellum Redox States and Cholinergic Functions Contribute to the Beneficial Effects of Silymarin Against Manganese-Induced Neurotoxicity

Manganese (Mn) is a potent neurotoxin involved in the initiation and progression of various cognitive disorders. Oxidative stress is reported as one of accepted mechanisms of Mn toxicity. The present study was designed to explore the effects of silymarin, a natural antioxidant, in attenuating the toxicity induced by Mn in rat cerebellum. In this investigation, rats were treated orally with MnCl₂ (20 mg/ml) for 30 days, subsets of these animals were treated intraperitoneally daily with silymarin (100 mg/kg) along with respective controls. Mn exposure caused a marked oxidative stress in cerebellum as indicated by a significant decrease in the activities of enzymatic antioxidants like superoxide dismutase, catalase and glutathione peroxidase and in the levels of non-enzymatic antioxidants like reduced glutathione (GSH), total thiols and vitamin C. Conversely an increase was obtained in lipid and protein markers such as thiobarbituric reactive acid substances, lipid hydroperoxide and protein carbonyl products contents. A Significant increase in acetylcholinesterase and a decrease in Na⁺/K⁺-ATPase activities were also shown, with a substantial rise in the expression of acetylcholinesterase and inducible nitric oxide synthase (iNOS), and nitric oxide levels. The potential effect of SIL to prevent Mn induced neurotoxicity was also reflected by histopathological observations. Rats exposed to Mn showed a reduced number and morphological alterations of cerebellar Purkinje cells. These phenomenons were completely reversed by SIL co-treatment. We concluded that silymarin may protect against Mn-induced oxidative stress in cerebellum by inhibiting both lipid and protein oxidation and by activating acetylcholinesterase and inducible nitric oxide synthase (iNOS) gene expression.     

Jellyfish Stings Trigger Gill Disorders and Increased Mortality in Farmed Sparus aurata (Linnaeus, 1758) in the Mediterranean Sea

Jellyfish are of particular concern for marine finfish aquaculture. In recent years repeated mass mortality episodes of farmed fish were caused by blooms of gelatinous cnidarian stingers, as a consequence of a wide range of hemolytic, cytotoxic, and neurotoxic properties of associated cnidocytes venoms. The mauve stinger jellyfish Pelagia noctiluca (Scyphozoa) has been identified as direct causative agent for several documented fish mortality events both in Northern Europe and the Mediterranean Sea aquaculture farms. We investigated the effects of P. noctiluca envenomations on the gilthead sea bream Sparus aurata by in vivo laboratory assays. Fish were incubated for 8 hours with jellyfish at 3 different densities in 300 l experimental tanks. Gill disorders were assessed by histological analyses and histopathological scoring of samples collected at time intervals from 3 hours to 4 weeks after initial exposure. Fish gills showed different extent and severity of gill lesions according to jellyfish density and incubation time, and long after the removal of jellyfish from tanks. Jellyfish envenomation elicits local and systemic inflammation reactions, histopathology and gill cell toxicity, with severe impacts on fish health. Altogether, these results shows P. noctiluca swarms may represent a high risk for Mediterranean finfish aquaculture farms, generating significant gill damage after only a few hours of contact with farmed S. aurata. Due to the growth of the aquaculture sector and the increased frequency of jellyfish blooms in the coastal waters, negative interactions between stinging jellyfish and farmed fish are likely to increase with the potential for significant economic losses.     

Silymarin, a natural antioxidant, protects cerebral cortex against manganese-induced neurotoxicity in adult rats

Manganese (Mn) is an essential element for biological systems, nevertheless occupational exposure to high levels of Mn can lead to neurodegenerative disorders, characterized by serious oxidative and neurotoxic effects with similarities to Parkinson’s disease. The aim of this study was to investigate the potential effects of silymarin (SIL), an antioxidant flavonoid, against manganese chloride induced neurotoxicity both in vivo (cerebral cortex of rats) and in vitro (Neuro2a cells). Twenty-eight male Wistar rats were randomly divided into four groups: the first group (C) received vehicle solution (i.p.) served as controls. The second group (Mn) received orally manganese chloride (20 mg/ml). The third group (Mn + SIL) received both Mn and SIL. The fourth group (SIL) received only SIL (100 mg/kg/day, i.p.). Animals exposed to Manganese chloride showed a significant increase in TBARS, NO, AOPP and PCO levels in cerebral cortex. These changes were accompanied by a decrease of enzymatic (SOD, CAT, GPx) and non-enzymatic (GSH, NpSH, Vit C) antioxidants. Co-administration of silymarin to Mn-treated rats significantly improved antioxidant enzyme activities and attenuated oxidative damages observed in brain tissue. The potential effect of SIL to prevent Mn induced neurotoxicity was also reflected by the microscopic study, indicative of its neuroprotective effects. We concluded that silymarin possesses neuroprotective potential, thus validating its use in alleviating manganese-induced neurodegenerative effects.     

Oxidative stress-related lung dysfunction by chromium(VI): alleviation by Citrus aurantium L.

Chromium(VI), a very strong oxidant, causes high cytotoxicity through oxidative stress in tissue systems. Our study investigated the potential ability of ethanolic Citrus aurantium L., family Rutaceae extract, used as a nutritional supplement, to alleviate lung oxidative damage induced by Cr(VI). A high-performance liquid chromatography coupled with a mass spectrometer method was developed to separate and identify flavonoids in C. aurantium L. Six flavonoids were identified, as (1) poncirin, (2) naringin, (3) naringenin, (4) quercetin, (5) isosinensetin, and (6) tetramethyl-o-isoscutellarein. Adult Wistar rats, used in this study, were divided into six groups of six animals each: group I served as controls which received standard diet, group II received via drinking water K₂Cr₂O₇ alone (700 ppm), groups III and IV were pretreated for 10 days with ethanol extract of C. aurantium L. at doses of 100 and 300 mg/kg body weight/day, respectively, and then K₂Cr₂O₇ was administrated during 3 weeks, and groups V and VI received during 10 days only C. aurantium L. ethanol extract at doses of 100 and 300 mg/kg/day, respectively. Ethanol extract of C. aurantium L. was administered orally. Rats exposed to Cr(VI) showed in lung an increase in malondialdehyde and protein carbonyl levels and a decrease in sulflydryl content, glutathione, nonprotein thiol, and vitamins C and E levels. Decreases in enzyme activities such as in Na⁺K⁺ ATPase, catalase, glutathione peroxidase, and superoxide dismutase were noted. Pretreatment with C. aurantium L. of chromium-treated rats ameliorated all biochemical parameters. Lung histological studies confirmed the biochemical parameters and the beneficial role of C. aurantium L.     

Cytogenetics and fluorescence in situ hybridization assessment of sex-chromosome mosaicism in Klinefelter's syndrome

A retrospective study was carried out in 152 infertile men to determine the prevalence of sex chromosome abnormalities among non-obstructive azoospermic and severe oligospermic men (n = 51) and to evaluate the feasibility of fluorescence in situ hybridization (FISH) techniques to assess mosaicism in Klinefelter's patients in comparison with conventional cytogenetics. Cytogenetic analysis were performed for 51 infertile men and among 14 chromosomal abnormalities found, nine were compatible with Klinefelter's syndrome. FISH staining with a CEP X/CEP Y probes were performed for Klinefelter's patients and for five of them; testes were biopsied for histopathologic examination. Six Klinefelter's patients showed a non-mosaic 47,XXY and three showed a 47,XXY/46,XY mosaic by G or R banding analysis of 20 cells with a ratio of 17%, 20% and 33%, respectively. FISH analysis confirmed mosaicism in only one patient (the first) in whom a third cells population was found. There was no relationship between the ratios of mosaicism by banding and FISH analysis. Conventional histopathologic findings in five non-mosaic Klinefelter's patients confirm the diagnosis of Sertoli Only Cells syndrome. FISH is recommended in Klinefelter's syndrome to define exactly the cytogenetic statute as mosaic or non-mosaic and then discussing prognosis and decision regarding fertility counseling.