34 resultados para Gastrointestinal motility

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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The hemizona assay (HZA) in Rhesus monkeys was employed to study the correlation of zona-binding ability with sperm motility or with naturally developing oocytes at various maturational stages. Oocytes from unstimulated ovaries were retrieved within 2 hr from monkeys sacrificed for vaccine production (in reproductive season, but with their menstrual cycles not determined). Oocytes were divided into four groups based on their morphological maturation: 1) Oocytes surrounded by more than one cumulus layer (MC); 2) Oocytes retaining intact germinal vesicle nuclei (GV); 3) Oocytes with germinal vesicle breakdown showing distinct perivitelline space (PVS); and 4) Oocytes extruding the first polar body (PB1). The mean numbers of sperm bound to hemizona for PBI, PVS, GV, and MC groups were 132.9 +/- 12.0, 71.5 +/- 10.1, 36.1 +/- 4.0, and 20.1 +/- 2.9 (Mean +/- SE), respectively. The four groups showed significant differences from each other in sperm/egg binding ability (P < 0.01). The number of bound sperm significantly increased with oocyte maturation. The present study also showed that zona-binding ability was also affected by sperm motility. For sperm with 67.7% motility and sperm with 31.2% motility, the average numbers of bound sperm were 43.5 +/- 2.2 and 25.3 +/- 2.9 (Mean +/- SE), respectively. There was significantly higher binding ability for sperm with higher motility (P < 0.01). The results suggest that: 1)The rhesus monkey model can serve as a very sensitive model for studying sperm/egg interaction by HZA; 2) Sperm motility positively correlated with sperm/egg binding; and 3) Sperm/egg binding ability increases with oocyte maturation. The binding ability is highest when oocytes matured to the PB1 stage, which is also the best opportunity for fertilization. This is strong evidence for the ''zona maturation'' hypothesis. (C) 1994 Wiley-Liss, Inc.

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BALB/c mice were immunized intragastrically with human sperm. Cells from the Peyer's patches and spleens of the immunized mice were for the preparation of hybridomas secreting antisperm monoclonal IgA (mcIgA). The specific ratio of IgA-secreting cells in Peyer's patches was much higher than that in spleen. The binding site on human sperm of 9 of 19 mcIgA was in the post-acrosomal region using an immunofluorescent assay. Two of eight selected mcIgA caused strong human sperm agglutination and three of them produced significant inhibition of mouse in vitro fertilization. No mcIgA tested caused obvious human sperm immobilization or inhibited mouse in vivo fertilization. In vitro assembly of selected mcIgA in ascites with mouse secretory component (SC) caused no significant changes in effects on sperm function and in vitro fertilization. By use of Western blotting, dimer or higher polymers were demonstrated in all selected mcIgAs and corresponding protein antigens in 6 of 8 selected mcIgAs. These results suggest that human sperm function may be inhibited and fertilization rate reduced by specific secretory IgA to human sperm and that secretory immunity to protein antigens of human sperm could be induced by intragastrointestinal immunization.

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Background: Habitat fragmentation may result in the reduction of diversity of parasite communities by affecting population size and dispersal pattern of species. In the flood plain of the Yangtze River in China, many lakes, which were once connected with the river, have become isolated since the 1950s from the river by the construction of dams and sluices, with many larger lakes subdivided into smaller ones by road embankments. These artificial barriers have inevitably obstructed the migration of fish between the river and lakes and also among lakes. In this study, the gastrointestinal helminth communities were investigated in a carnivorous fish, the yellowhead catfish Pelteobagrus fulvidraco, from two connected and five isolated lakes in the flood plain in order to detect the effect of lake fragmentation on the parasite communities. Results: A total of 11 species of helminths were recorded in the stomach and intestine of P. fulvidraco from seven lakes, including two lakes connected with the Yangtze River, i.e. Poyang and Dongting lakes, and five isolated lakes, i.e. Honghu, Liangzi, Tangxun, Niushan and Baoan lakes. Mean helminth individuals and diversity of helminth communities in Honghu and Dongting lakes was lower than in the other five lakes. The nematode Procamallanus fulvidraconis was the dominant species of communities in all the seven lakes. No significant difference in the Shannon-Wiener index was detected between connected lakes (0.48) and isolated lakes (0.50). The similarity of helminth communities between Niushan and Baoan lakes was the highest (0.6708), and the lowest was between Tangxun and Dongting lakes (0.1807). The similarity was low between Dongting and the other lakes, and the similarity decreased with the geographic distance among these lakes. The helminth community in one connected lake, Poyang Lake was clustered with isolated lakes, but the community in Dongting Lake was separated in the tree. Conclusion: The similarity in the helminth communities of this fish in the flood-plain lakes may be attributed to the historical connection of these habitats and to the completion of the life-cycles of this fish as well as the helminth species within the investigated habitats. The diversity and the digenean majority in the helminth communities can be related to the diet of this fish, and to the lacustrine and macrophytic characters of the habitats. The lake isolation from the river had little detectable effect on the helminth communities of the catfish in flood-plain lakes of the Yangtze River. The low similarities in helminth communities between the Dongting Lake and others may just be a reflection of its unique water environment and anthropogenic alterations or fragmentation in this lake.

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We investigated the effects of Ginsenoside R-e on human sperm motility in fertile and asthenozoospermic infertile individuals in vitro and the mechanism by which the Ginsenosides play their roles. The semen samples were obtained from 10 fertile volunteers and 10 asthenozoospermic infertile patients. Spermatozoa were separated by Percoll and incubated with 0, 1, 10 or 100 mu M of Ginsenoside R-e. Total sperm motility and progressive motility were measured by computer-aided sperm analyzer (CASA). Nitric oxide synthase (NOS) activity was determined by the H-3-arginine to H-3-citrulline conversion assay, and the NOS protein was examined by the Western blot analysis. The production of sperm nitric oxide (NO) was detected using the Griess reaction. The results showed that Ginsenoside R-e significantly enhanced both fertile and infertile sperm motility, NOS activity and NO production in a concentration-dependent manner. Sodium nitroprusside (SNP, 100 nM), a NO donor, mimicked the effects of Ginsenoside R-e. And pretreatment with a NOS inhibitor N-omega-Nitro-L-arginine methyl ester (L-NAME, 100 mu M) or a NO scavenger N-Acetyl-L-cysteine (LNAC, 1 mM) completely blocked the effects of Ginsenoside R-e. Data suggested that Ginsenoside R-e is beneficial to sperm motility, and that induction of NOS to increase NO production may be involved in this benefit.

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Large yellow croaker, Pseudosciaena crocea, exhibit sexually dimorphic growth, with females growing faster and reaching larger adult sizes than males. Thus, development of techniques for preferentially producing females is necessary to optimize production of these species. We have established a protocol to produce all-female croaker P. crocea through induction of meiotic gynogenesis with homologous sperm. The first set of experiments investigated the ultra-violet (UV) irradiation on sperm motility and duration of sperm activity to determine the optimal UV dosage for genetic inactivation of sperm, yet retaining adequate motility for activation of eggs. Milt from several males was diluted 1: 100 with Ringer's solution and UV irradiated with doses ranging from 0-150 J cm (-2). The results indicated that motility and duration of activity generally decreased with increased UV doses. At UV doses greater than 105 J cm(-2), after fertilization, motility was < 10% and fertilization rates were significantly lower. Highest hatching rate was obtained at 75 J cm -2. A second set of experiments was carried out to determine appropriate conditions of cold shock for retention of the 2nd polar body in P. crocea eggs after fertilization with UV-inactivated sperm by altering the timing, temperature and duration of shock. At 208 degrees C, shock applied at 3 min after fertilization resulted in higher survival rate of larvae at 6 h after hatching. Results of different combinations of three shock temperatures ( 28 degrees C, 38 degrees C or 48 degrees C) and five shock durations ( 4 min, 8 min, 12 min, 16 min or 20 min) at 3 min after fertilization demonstrated that shocks of 12 min gave highest production of diploid gynogens. Statistical analysis revealed that maximum production of diploid gynogens (44.55 +/- 2.99%) were obtained at 38 degrees C. The results of this study indicate that the use of UV-irradiated homologous sperm for activation of P. crocea eggs and cold shock for polar body retention is an effective method for producing gynogenetic offspring.

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The effect of feeding 0, 4, 8 and 16% rapeseed oil from 12-42 days of age was studied in broiler chickens on performance, digestibility of nutrients, and development of gastrointestinal tract, protein and energy metabolism. Thirty six female chickens (Ross 208) with initial body weight average 246 g were allocated to the four groups and kept pair-wise in metabolism cages. The chickens were fed similar amounts of metabolisable energy (ME) per day and similar amounts of essential amino acids relative to ME by adjusting with crystalline amino acids. The chickens were subjected to four balance periods each of five days with two 24 h measurements of gas exchange in two open-air-circuit respiration chambers inserted on the second and third day of each period. The addition of rapeseed oil increased the amount of gutfill indicating a reduced rate of passage and causing a hypertrophy of the gastrointestinal tract. There was a positive effect on feed utilisation as well as on digestibility especially of dietary fat together with higher utilisation of protein with addition of rapeseed oil. The partial fat digestibility of rapeseed oil estimated by regression was 91.1% and the partial metabolisability (ME/GE) of the rapeseed oil was estimated to 85% yielding an apparent metabolisable energy value of 34.30 MJ/kg.

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Although spermatozoa from several species of nonhuman primates have been cryopreserved, there has been no report of success with rhesus macaque spermatozoa as judged by functional assays. Two Tris-egg yolk freezing media. TEST and TTE. which have: been successfully used for cynomolgus macaque (Macaca fascicularis) spermatozoa, were compared for cryopreservation of spermatozoa From four rhesus macaques (Macaca mulatta). The postthaw motility (percentage and duration) of spermatozoa cryopreserved in TTE was much higher than that for spermatozoa cryopreserved in TEST. The function of sperm cryopreserved in TTE was evaluated by in vitro fertilization or oocytes collected from gonadotropin-stimulated prepubertal rhesus macaques. Of the inseminated oocytes. 82 +/- 13% were fertilized and 63 +/- 22 and 39 +/- 21% of the resulting zygotes developed into morulae and blastocysts. respectively. These results indicate that rhesus macaque spermatozoa can be effectively cryopreserved in TTE medium. This finding will facilitate the application of in vivo and in vitro assisted reproductive technologies in this species. (C) 2001 Academic Press.

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Glycerol and dimethyl sulfoxide (DMSO) are widely used as penetrating cryoprotectants in the freezing of sperm, and various concentrations are applied in different species and laboratories. The present study aimed to examine the effect of these two cryoprotectants at different concentrations (2%, 5%, 10%, and 15% glycerol or DMSO) on rhesus monkey sperm cryopreservation. The results showed that the highest recovery of post-thaw sperm motility, and plasma membrane and acrosome integrity was achieved when the sperm was frozen with 5% glycerol. Spermatozoa cryopreserved with 15% DMSO showed the lowest post-thaw sperm motility, and spermatozoa cryopreserved with 15% glycerol and 15% DMSO showed the lowest plasma membrane integrity among the eight groups. The results achieved with 5% glycerol were significantly better for all parameters than those obtained with 5% DMSO. The functional cryosurvival of sperm frozen with 5% glycerol was further assessed by in vitro fertilization (IVF). Overall, 85.7% of the oocytes were successfully fertilized, and 51.4% and 5.7% of the resulting zygotes developed into morulae and blastocysts, respectively. The results indicate that the type and concentration of the penetrating cryoprotectant used can greatly affect the survival of rhesus monkey sperm after it is frozen and thawed. The suitable glycerol level for rhesus monkey sperm freezing is 5%, and DMSO is not suitable for rhesus monkey sperm cryopreservation. (C) 2004 Wiley-Liss, Inc.

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Many neuroendocrine peptides that are distributed in amphibian gastrointestinal tract and central nervous system are also found in amphibian skins, and these peptides are classified into skin-gut-brain triangle peptides, such as bombesins, gastrin-releasi

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A novel strain, D3(T), isolated from a field-soil sample obtained from Anhui Province, PR China, was characterized taxonomically by using a polyphasic approach. The cells were Gram-negative, yellow-pigmented rods devoid of flagella, but showing gliding motility. The organism was able to grow at 5-37 degrees C and at pH 4.0-10.0. A comparative 16S rRNA gene sequence analysis indicated that strain D3(T) is a member of the genus Flavobacterium, sharing highest sequence similarity with the type strain of Flavobacterium defluvii (96.7 %). The major isoprenoid quinone was MK-6 and the predominant fatty acids were iso-C-15:0, summed feature 3 (C-16:1 omega 7c and/or iso-C-15:0 2-OH) and C-16:0. The DNA G + C content was 31.4 mol%. On the basis of phylogenetic and phenotypic data, strain D3(T) represents a novel species within the genus Flavobacterium, for which the name Flavobacterium anhuiense sp. nov. is proposed. The type strain is D3(T) (=KCTC 22128(T)= CGIVICC 1.6859(T)).

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Semenogelin I (SgI) is one of the most abundant proteins in human seminal plasma. SgI plays a key role in sperm coagulation and spermatozoon immobilization. in addition, SgI and/or its proteolytic fragments are involved in regulating spermatozoon motility

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A nerve growth factor (NGF) was isolated from the venom of Chinese cobra (Naja naja ntr a) by ion exchange chromatography, gel filtration and fast protein liquid chromatography (FPLC). The N-terminal sequence of 22 amino acid residues was identical with other NGFs previously purified from the venom of the same genus. The NGF monomer molecular weight was estimated to be 13 500 by reducing SDS-PAGE and the isoelectric point was determined to be 7.2 by isoelectric focusing electrophoresis. NGF improved the epididymal sperm motility of male rats and increased the pregnancy rate and fetus number of mated female rats. The serum levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) of male rats administrated NGF + gossypol was lower than that of male rats administrated gossypol. Histological sections of testes and epididymides showed that NGF reduced the destructive effects of gossypol on rat testes. (C) 1999 Elsevier Science Inc. All rights reserved.

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Motilin and ghrelin, members of a structure-function-related hormone family, play important roles in gastrointestinal function, regulation of energy homeostasis and growth hormone secretion. We observed episodic evolution in both of their prehormone gene sequences during primitive placental mammal evolution, during which most of the nonsynonymous changes result in radical substitution. Of note, a functional obestatin hormone might have only originated after this episodic evolution event. Early in placental mammal evolution, a series of biology complexities evolved. At the same time the motilin and ghrelin prehormone genes, which play important roles in several of these processes, experienced episodic evolution with dramatic changes in their coding sequences. These observations suggest that some of the lineage-specific physiological adaptations are due to episodic evolution of the motilin and ghrelin genes.