276 results match your criteria: "School of Veterinary Medicine Hannover[Affiliation]"

Selective sperm binding to pig oviductal epithelium in vitro.

Reproduction

June 2001

Institute for Reproductive Medicine, School of Veterinary Medicine Hannover, Bünteweg 15, D-30559 Hannover, Germany.

The sperm reservoir in the caudal isthmus of the oviduct of a number of species is created by binding of spermatozoa to oviductal epithelium. The sperm reservoir fulfills a number of functions such as control of sperm transport, maintenance of sperm viability and modulation of capacitation. The initial capacities of ejaculated and epididymal boar spermatozoa to bind to oviductal epithelium were investigated using a modified pig oviductal explant assay.

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The objective of this study was to investigate the relationship between different screening tests of haemostasis and amidolytic plasma activities of unfractionated (standard) heparin in dogs. Different doses of intravenous (i.v.

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Carbohydrates are hydrolyzed in the intestinal lumen by specific enzymes to monosaccharides before transport across the brush border membrane of epithelial cells into the cell interior. The enzymes implicated in the digestion of carbohydrates in the intestinal lumen are membrane-bound glycoproteins that are expressed at the apical domain of the enterocytes. Absent or reduced activity of one of these enzymes is the cause of disaccharide intolerance and malabsorption, the symptoms of which are abdominal pain, cramps or distention, flatulence, nausea and osmotic diarrhea.

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Luteal tissue specimens of corpora lutea of oestrous cycle and pregnancy, post partum corpora lutea, and of luteinised follicular cysts of cows were harvested at slaughter. Cellular proliferation was examined employing Ki-67 immunocytochemistry. Ki-67 immunoreactivities could mainly be demonstrated within the nuclei of the theca interna and theca externa derived cell populations of cyclic corpora lutea.

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When cows develop endometritis after birth, Escherichia coli and Arcanobacterium pyogenes are usually the most prominent bacteria present in bovine uterine lochial secretions. A. pyogenes alone is rarely found in the course of a disturbed puerperium.

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During the breeding season, 42 adult German Improved Fawn nanny goats were superovulated with a single administration of pFSH, hMG or eCG at the end or a single dose of pFSH 36h before the end of estrus synchronization. Development of follicles and corpora lutea were observed by ultrasonic scanning of the ovaries every 8h from gonadotrophin treatment, until the end of estrus and once daily for the following 6 days. Differences in follicular dynamics could be realized in the four superovulation groups, and the duration of the stimulatory action following the single gonadotrophin challenge was estimated to last for 40-72h in the case of pFSH and to exceed 72h in the case of hMG and eCG treatment groups.

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During the breeding season, 42 adult German Improved Fawn nanny goats were superovulated with a single dose of pFSH, hMG or eCG at the end or a single application of pFSH 36h before the end of synchronization treatment using flugestone acetate (FGA). Plasma sampling was performed immediately before and 1h after gonadotrophin treatment, twice daily during pre-estrus and estrus and once daily during post-estrus in order to determine peripheral estradiol-17beta and progesterone levels. During that period, ovarian dynamics was followed by serial ultrasound scans (8h interval during pre-estrus and estrus and once daily during post-estrus).

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To study the interaction of retinoid-induced limb defects and cleft palate on day 11 of gestation, a RXR-selective agonist (AGN191701, an arylpropenyl-thiophene-carboxylic acid derivative, 20 mg/kg orally) was coadministered with a RARalpha-agonist (Am580, an arylcarboxamidobenzoic acid derivative, 5 mg/kg orally) to NMRI mice. AGN191701 was neither fetotoxic nor teratogenic at the dose used but potentiated Am580-induced limb defects and cleft palate and prevented Am580-induced fetal weight retardation. These results suggest that Am580-induced limb defects and probably cleft palate on day 11 of gestation may be mediated via RARalpha-RXR heterodimerization, particularly in the absence of toxicokinetic interactions.

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Steroid hormones play an important role in placental development. However, the exact cellular site of hormone action has not been evaluated in bovine placentomes. Thus, the present immunohistochemical study was designed to assess the distribution of progesterone receptors, oestrogen receptors and glucocorticoid receptors in bovine placentomes.

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Uterine biopsies were collected at cycle days 1 (oestrous), 8, 15 and 19 in six cows. Unfixed cryostat sections were used to immunolocalise collagen types I, III, IV and VI by an indirect FITC method. Collagen I was sparsely found in the endometrium where it formed a fine meshwork of thin fibres directly below the surface epithelium, clearly visible only at cycle days 8 and 15.

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CGS 21680 exerts marked antidystonic effects in a genetic model of paroxysmal dyskinesia.

Eur J Pharmacol

September 2000

Department of Pharmacology, Toxicology and Pharmacy, School of Veterinary Medicine Hannover, Bünteweg 17, 30559, Hannover, Germany.

The effect of the adenosine A(2A) receptor agonist CGS 21680 (2-carboxyethyl)phenylethylamino]-5'-N-ethylcarbonyamido-ade nosine) on severity of dystonia was examined in genetically dystonic hamsters which exhibit attacks of dystonic and choreoathetotic disturbances in response to mild stress. CGS 21680 significantly reduced the severity of dystonia (0.5, 1.

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Considerable amounts of several saccharide residues (alpha-D-Man, beta-D-GlcNAc, alpha-D-GalNAc, beta-D-Gal, alpha-D-Gal, alpha-L-Fuc, NeuNAc) are demonstrated by lectin histochemistry in the sections of the sebaceous glands, and, particularly, the apocrine tubular glands of the common seal. These sugars may be liberated on the skin surface by microbial activities and, then, represent a general antimicrobial protection mechanism of the skin because of their ability to inhibit the adherence of different bacteria and fungi to the epidermis.

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Congenital sucrase-isomaltase deficiency (CSID) is an autosomal recessive human intestinal disorder that is clinically characterized by fermentative diarrhea, abdominal pain, and cramps upon ingestion of sugar. The symptoms are the consequence of absent or drastically reduced enzymatic activities of sucrase and isomaltase, the components of the intestinal integral membrane glycoprotein sucrase-isomaltase (SI). Several known phenotypes of CSID result from an altered posttranslational processing of SI.

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An 11-yr-old female Eurasian otter (Lutra lutra) presented with multiple cutaneous nodules identified histologically as malignant melanomas of spindle cell and epithelioid cell type. Metastases were detected in lymph nodes and liver, and the tumor, which was derived from melanocytes, showed aggressive biological behavior. Only occasional reports exist of neoplastic disease in otters.

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The osmotic reactivity of boar spermatozoa during incubation in vitro was studied using a hypo-osmotic swelling test in conjunction with electronic measurement of cell volume. Sperm populations showed fluctuations in both iso-osmotic cell volume and hypo-osmotic volume response that fitted mathematical models for periodicity. Significant differences of frequency and amplitude were observed during sperm incubation under capacitating conditions as compared with those under non-capacitating conditions.

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Vitamin E deficiency and linoleic acid-feeding lead to nutritional encephalomalacia (NE) in chicks, affecting the cerebellum exclusively. The relevance of lipid peroxidation (LPO) products to the pathogenesis of the disease was studied. Laying hens received a diet low in vitamin E.

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Differences in sperm fertilizing capacity of males often remain undetected by routine semen parameters. Heterospermic insemination with equal numbers of spermatozoa from 2 males is an accurate method for assessing differences in fertility. Use of heterospermic insemination depends on a reliable, efficient assay to identify paternity of conceptuses or offspring.

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Epidermolytic hyperkeratosis (EH) in man is a complex of congenital, ichthyosiform skin diseases characterized clinically by blistering and hyperkeratosis. These clinical signs are the result of a collapse of the cytoskeleton, seen ultrastructurally as tonofilament clumping and cytolysis within terminally differentiating epidermal cells. In man, specific mutations in keratin 1, 2e, 9 or 10 underlie the various types of EH.

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Lactase-phlorizin hydrolase (LPH) is a membrane bound intestinal hydrolase, with an extracellular domain comprising 4 homologous regions. LPH is synthesized as a large polypeptide precursor, pro-LPH, that undergoes several intra- and extracellular proteolytic steps to generate the final brush-border membrane form LPHbeta(final). Pro-LPH is associated through homologous domain IV with the membrane through a transmembrane domain.

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The distinct protein and lipid constituents of the apical and basolateral membranes in polarized cells are sorted by specific signals. O-Glycosylation of a highly polarized intestinal brush-border protein sucrase isomaltase is implicated in its apical sorting through interaction with sphingolipid-cholesterol microdomains. We characterized the structural determinants required for this mechanism by focusing on two major domains in pro-SI, the membrane anchor and the Ser/Thr-rich stalk domain.

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Previous studies showed that intrauterine infusion of seminal plasma at the onset of oestrus could advance ovulation in pigs, possibly to enhance the chances of fertilization by optimizing the chronological events of fertilization. This effect has been attributed to a local unilateral mechanism whereby infusion into a single uterine horn advances ovulation in the adjacent ovary. The present study was designed to elucidate possible mechanisms of local signal transduction.

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Seven Vibrio-like field strains of German origin were isolated culturally from diseased domesticated ducks, muscovy ducks and geese, and were compared with reference strains NCTC 8443 (type strain) and NCTC 11170 of Vibrio metschnicovii using classical phenotypic and chemotaxonomic tests. Some V. cholerae strains were included in the chemotaxonomic tests for comparative purposes.

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