Summary
Human spermatozoa from healthy donors (n= 7) were washed in Tyrode's medium containing 0.6 mg/ml freeze‐dried egg yolk, filtered through glass wool and exposed to 0.5, 5, 50, 500 or 1000 μM ...hydrogen hexachloroplatinate. Viability, membrane integrity and the acrosome reaction were examined using trypan blue exclusion, hypo‐osmotic swelling test and fluoresceinated Pisum sativum agglutinin, respectively, after incubation for 3 or 6 h at 37°C. While sperm motility, viability and membrane integrity were not affected by the platinum compound after incubation for 3 h, the number of acrosome‐reacted spermatozoa increased from 16.0 ± 6.4% (control, mean ± SEM) to 21.0 ± 3.3 (0.5 μM), 22.3 ± 4.3% (5 μM), 28.0 ± 4.3% (50 μM, p<0.01), 29.3 ± 3.9% (500 μM, p<0.01) and 43.9 ± 7.4% (1mM, p<0.001); a further increase was detected after incubation for 6 h. However, the percentages of dead and immotile spermatozoa and those with defective membranes were also higher, suggesting that the acrosome reaction was caused by degenerative processes after long‐term incubation. In conclusion, hydrogen hexachloroplatinate does not affect sperm motility, membrane integrity or viability, but it does induce the acrosome reaction after incubation for 3 h before cytotoxic effects are measurable. Similar effects of halide salts of platinum on receptor‐mediated exocytosis have been described in other cells such as mast cells and basophils in vivo and in vitro.
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BFBNIB, FZAB, GIS, IJS, KILJ, OILJ, SBCE, SBMB, UL, UPUK
Based on an information theoretical approach, we investigate feature selection processes in saccadic object and scene analysis. Saccadic eye movements of human observers are recorded for a variety of ...natural and artificial test images. These experimental data are used for a statistical evaluation of the fixated image regions. Analysis of second-order statistics indicates that regions with higher spatial variance have a higher probability to be fixated, but no significant differences beyond these variance effects could be found at the level of power spectra. By contrast, an investigation with higher-order statistics, as reflected in the bispectral density, yielded clear structural differences between the image regions selected by saccadic eye movements as opposed to regions selected by a random process. These results indicate that nonredundant, intrinsically two-dimensional image features like curved lines and edges, occlusions, isolated spots, etc. play an important role in the saccadic selection process which must be integrated with top-down knowledge to fully predict object and scene analysis by human observers.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Varicocele is an important cause of male subfertility which may lead to varying degrees of pathological semen quality. Removal of varicocele can be an effective andrological treatment if associated ...with subfertility. Therefore, in a retrospective study, two possible methods of treatment, high ligation and transcatheter sclerotherapy, were compared with regard to semen parameters and conception rates. Three months after treatment, only high ligation showed a significant improvement of sperm concentration, morphology and motility. Sperm concentration and motility, however, similarly increased in both groups after six to nine months. Sclerotherapy showed a better conception rate of 25% than the surgical group with 14%. Sclerotherapy should be the treatment of first choice if associated with subfertility.
The cause of deeply penetrating ulcers of Atlantic menhaden Brevoortia tyrannus has been the subject of significant research efforts in recent years. These lesions and the associated syndrome termed ...ulcerative mycosis have been observed along the East Coast of the United States since at least the early 1980s. Although Aphanomyces spp. were isolated from these lesions in the mid to late 1980s, similar lesions could not be reproduced by experimental infections of Atlantic menhaden with these isolates. The identical characteristic histologic appearance of granulomatous inflammation surrounding the penetrating fungal hyphae occurs in fish with epizootic ulcerative syndrome (EUS), as reported throughout South Asia, Japan, and Australia. Aphanomyces invadans has been found to be the causative agent of EUS in all of these countries. Using methods developed for the study of EUS, we successfully isolated an organism for which the DNA sequence, morphology, temperature and salinity growth characteristics, and infectivity of chevron snakehead Channa striata are identical to A. invadans. Using the polymerase chain reaction assay for A. invadans, we were able to demonstrate the presence of the organism from Atlantic menhaden lesions collected in U.S. estuarine waters from Delaware to South Carolina. In addition, the organism was present in lesions on a bluegill Lepomis macrochirus from a farm pond in Georgia and channel catfish Ictalurus punctatus from a farm pond in Louisiana.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Environmental noxae may impair male fertility. Different compartments and types of cell must be considered as possible targets for drugs, such lifestyle factors as alcohol and smoking, and various ...environmental and occupational agents. However, the mechanisms of action in humans are known for only a limited number of noxae. For the clinical andrologist, the identification of relevant exposure to reproductive toxicants by careful history-taking remains of great importance. Nevertheless, evaluation of the relevant risks in the individual is often not possible.
Fertilization consists of a sequence of complex events which culminates in the fusion of the genetic information provided by two parent cells, thus leading to the formation of a new individuum. The ...male gamete develops in the testis, acquires forward motility and fertilizing capacity during maturation in the epididymis, and after capacitation undergoes the acrosome reaction in the female reproductive tract. The female gamete matures in the cyclically developing follicles and, by the time of ovulation, reaches a quiescent stage at metaphase II of meiosis. Gamete fusion occurs in the distal tube, and involves a series of modifications on the egg surface and its investments, intended to protect the developing embryo from polyspermy.
À la veille de Mai 68, le Languedoc-Roussillon, qui compte environ 1,7 million d’habitants, est un espace en pleine mutation : région attractive handicapée par une faible activité et frappée par des ...crises agricoles et industrielles chroniques, le secteur primaire l’emporte sur le secteur secondaire jusqu’au début des années soixante, notamment en raison de l’importance de la viticulture. L’ampleur des évolutions économiques à l’œuvre peut se lire dans les dynamiques de la population qui abou...
Enteric redmouth disease is described in chinook salmon (Oncorhynchus tshawytscha) at a state hatchery in Sand Ridge, Illinois. Biochemical, isoenzyme, and serological data indicated that the ...epizootic was caused by a sorbitol-fermenting Serovar 2 strain of Yersinia ruckeri. In laboratory experiments the isolate was pathogenic for both brook trout (Salvelinus fontinalis) and Atlantic salmon (Salmo salar).
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