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51.
A series of experiments was performed to examine the effects of blastomere biopsies on subsequent development of IVF-derived bovine embryos. The first experiment was designed to assess the optimal time for blastomere removal. One blastomere was removed either 48 or 72 h after IVF. Biopsy at 48 h resulted in 17.2% of embryos proceeding to the blastocyst stage, which was lower than when biopsies were performed at 72 h (37.5%, p < 0.05). In the second experiment, embryos were cultured either under atmospheric or 5% O(2) following blastomere removal. Biopsies had no effect on rate of blastocyst formation with 36% of controls and 33.7% of biopsied embryos proceeding to that stage. However, culture under 5% O(2) significantly increased the number of blastocysts from 29.9% to 40.3% (p < 0.05). This effect was significant in both biopsied and control embryos. In the final experiment, biopsied embryos were again cultured under different oxygen tension. Blastocysts were collected and cultured individually for 48 h in medium droplets in their respective O(2) concentration after which time the medium was assayed for concentration of interferon-tau (IFN-tau). Reduced O(2) concentration again significantly increased blastocyst formation from 24.9% to 41.9% (p < 0.05). IFN-tau secretion was not affected by biopsies, but culture under atmospheric O(2) resulted in significantly increased IFN-tau concentration in medium droplets (12274.0 +/- 2825.9 pM vs 5046.5 +/- 2562.2 pM; p < 0.05). 相似文献
52.
AIMS: To study the adhesion properties of a biotype 4, serotype O:3 (human pathogenic) strain of Yersinia enterocolitica and to determine if adhesion in vitro and colonisation in vivo can be prevented by competition with a biotype 1A, serotype O:6,30 (non-pathogenic) strain. To study interaction between Y. enterocolitica biotype 4, serotype O:3 and cultured epithelial cells using the synthetic tripeptide arginine-glycine-aspartic acid (RGD). METHODS: The human intestinal epithelial (HEp-2) cell line was used for in vitro studies. Inocula of Y. enterocolitica biotype 4, serotype O:3 radiolabelled using tritium were incubated with HEp-2 cells and RGD tripeptide, or with Y. enterocolitica biotype 1A, serotype O:6,30 sequentially or concurrently, then washed and lysed, and radioactivity measured to determine the effect of RGD on adhesion, and competitive exclusion of pathogenic by non-pathogenic bacteria. For in vivo studies, two groups of 5-week-old piglets (n=5/group) were sequentially inoculated orally with 5x109 colony forming units (cfu) of either a non-pathogenic biotype 1A, serotype O:6,30 strain of Y. enterocolitica followed by a pathogenic biotype 4, serotype O:3 strain, or vice versa. Pigs were monitored for carriage of strains using bacterial culture and a multiplex polymerase chain reaction (PCR). RESULTS: The RGD tripeptide significantly inhibited adherence of the pathogenic Y. enterocolitica strain to cultured epithelial cells, suggesting that adhesion involved the RGD tripeptide sequence. The non-pathogenic biotype 1A, serotype O:6,30 strain of Y. enterocolitica prevented adhesion of the pathogenic strain to cells in vitro when allowed to adhere first. Pathogenic Y. enterocolitica was consistently isolated from rectal swabs from 80-100% of pigs on all sampling occasions but not from oral swabs after 14 days in pigs first inoculated with the non- pathogenic strain or at 26 days in pigs first inoculated with the pathogenic strain. CONCLUSIONS: A non-pathogenic strain of Y. enterocolitica reduced adhesion of a human pathogenic strain in vitro but not in vivo. 相似文献
53.
F Hill PB Stark RT Stebbins ER Anderson HM Antia TM Brown TL Duvall DA Haber JW Harvey DH Hathaway R Howe RP Hubbard HP Jones JR Kennedy SG Korzennik AG Kosovichev JW Leibacher KG Libbrecht JA Pintar EJ Rhodes J Schou MJ Thompson S Tomczyk CG Toner R Toussaint WE Williams 《Science (New York, N.Y.)》1996,272(5266):1292-1296
The Global Oscillation Network Group (GONG) project estimates the frequencies, amplitudes, and linewidths of more than 250,000 acoustic resonances of the sun from data sets lasting 36 days. The frequency resolution of a single data set is 0.321 microhertz. For frequencies averaged over the azimuthal order m, the median formal error is 0.044 microhertz, and the associated median fractional error is 1.6 x 10(-5). For a 3-year data set, the fractional error is expected to be 3 x 10(-6). The GONG m-averaged frequency measurements differ from other helioseismic data sets by 0.03 to 0.08 microhertz. The differences arise from a combination of systematic errors, random errors, and possible changes in solar structure. 相似文献
54.
HM Fischer E Pehlke G Wibberenz LJ Lanzerotti JD Mihalov 《Science (New York, N.Y.)》1996,272(5263):856-858
The energetic particles investigation carried by the Galileo probe measured the energy and angular distributions of the high-energy particles from near the orbit of Io to probe entry into the jovian atmosphere. Jupiter's inner radiation region had extremely large fluxes of energetic electrons and protons; intensities peaked at approximately2.2RJ (where RJ is the radius of Jupiter). Absorption of the measured particles was found near the outer edge of the bright dust ring. The instrument measured intense fluxes of high-energy helium ions (approximately62 megaelectron volts per nucleon) that peaked at approximately1.5RJ inside the bright dust ring. The abundances of all particle species decreased sharply at approximately1.35RJ; this decrease defines the innermost edge of the equatorial jovian radiation. 相似文献
55.
Lower Cretaceous bulk carbonate from deep sea sediments records sudden inputs of strontium resulting from the exposure of continental shelves. Strontium data from an interval spanning 7 million years in the Berriasian-Valanginian imply that global sea level fluctuated about 50 meters over time scales of 200,000 to 500,000 years, which is in agreement with the Exxon sea level curve. Oxygen isotope measurements indicate that the growth of continental ice sheets caused these rapid sea level changes. If glaciation caused all the rapid sea level changes in the Cretaceous that are indicated by the Exxon curve, then an Antarctic ice sheet may have existed despite overall climatic warmth. 相似文献
56.
Therapeutic efficacy of topical hydrocortisone aceponate in experimental flea-allergy dermatitis in dogs 总被引：1，自引：1，他引：0
Objective To evaluate the treatment efficacy of a topical spray containing hydrocortisone aceponate (HCA) on dogs with flea-allergy dermatitis (FAD).
Design A controlled clinical study was conducted on dogs with experimentally induced FAD. Sixteen laboratory beagles with mild to moderate clinical signs were divided into two groups. The test group received HCA by topical spray once daily for 7 days, while the control group did not. Pruritic events (time and frequency) were videotaped and then scored. Clinical signs (erythema, papules, excoriation and alopecia) present on four anatomical regions were monitored and their severity directly assessed.
Results After 2 days, pruritus was reduced by 94% in the treatment group and by 24% in the control group (P = 0.014) in cumulative time, and by 86% versus 34% (P = 0.034) in frequency. The HCA spray also resulted in significant improvements in overall clinical signs: 23% versus 0% in the control group (P = 0.0006) on day 3 and 43% versus 15% in the control group (P = 0.0006) on day 7. During the 7-day trial, no drug-related adverse effects were observed.
Conclusions Topical treatment with HCA showed a rapid and potent antipruritic effect on dogs with FAD. HCA also demonstrated significant overall therapeutic effects on FAD-associated skin lesions. 相似文献
Design A controlled clinical study was conducted on dogs with experimentally induced FAD. Sixteen laboratory beagles with mild to moderate clinical signs were divided into two groups. The test group received HCA by topical spray once daily for 7 days, while the control group did not. Pruritic events (time and frequency) were videotaped and then scored. Clinical signs (erythema, papules, excoriation and alopecia) present on four anatomical regions were monitored and their severity directly assessed.
Results After 2 days, pruritus was reduced by 94% in the treatment group and by 24% in the control group (P = 0.014) in cumulative time, and by 86% versus 34% (P = 0.034) in frequency. The HCA spray also resulted in significant improvements in overall clinical signs: 23% versus 0% in the control group (P = 0.0006) on day 3 and 43% versus 15% in the control group (P = 0.0006) on day 7. During the 7-day trial, no drug-related adverse effects were observed.
Conclusions Topical treatment with HCA showed a rapid and potent antipruritic effect on dogs with FAD. HCA also demonstrated significant overall therapeutic effects on FAD-associated skin lesions. 相似文献
57.
HM Mutembei MP Kowalewski B Ugele G Schuler B Hoffmann 《Reproduction in domestic animals》2009,44(1):17-23
Oestrogens are essential for male fertility targeting the testicular-epididymal compartment. However, the underlying mechanisms are only vaguely known and species specificities must be considered. The boar has a remarkably high testicular-oestrogen output, with the biologically inactive oestrone-sulphate being the major oestrogen occurring in the testicular vein. In the boar testis and epididymis, activity of steroid sulphatase (StS) and oestrogen sulphotransferase has been demonstrated. Thus apart from their synthesis in Leydig cells, provision of biologically active free oestrone seems also to depend on the activity and localization of these enzymes. Our aim was to establish expression patterns and activity of StS in boar testis. Testes were randomly collected from healthy boars and allotted to five age groups, five animals in each, aged 50, 100, 150, 200 and 250 days. Three extra boars aged over 250 days were castrated to obtain fresh tissue for enzyme activity tests. Immunohistochemistry detected StS only in the cytoplasm of Leydig cells and – except for day-50 group in which 65.1 ± 4.9% (X ± SD) of the cells were positive – expression was constant with virtually all the cells staining positive. RT-PCR and in situ hybridization confirmed expression and localization of StS mRNA. The V max and K m value (X ± SD) for StS was 24.05 ± 0.3 fmol/s/μg protein and 2.15 ± 0.12 μ m . These data suggest that StS within the Leydig cells of the boar is involved in modulation of testicular oestrogen bioavailability and that the site of sulpho-conjugation is not the testis but a different compartment of the testes–epididymidis complex. 相似文献
58.
AR Günzel-Apel T Höftmann S Nottorf E Politt A Meyer-Lindenberg HO Hoppen A Einspanier HM Knijn R Mischke 《Reproduction in domestic animals》2009,44(S2):174-181
Pharmacologically-induced luteolysis or treatment with an antiprogestin in early post-implantation pregnancy in dogs results in asynchronous death and resorption of conceptuses, indicating variable rates of response of individual conceptuses towards progesterone deficiency. This variability also seems to occur in bitches showing pregnancy failure in response to spontaneous luteal deficiency. In a total of 10 beagle pregnancies (two consecutive pregnancies of five bitches), abortifacient treatments beginning on day 24 after ovulation (ov) involved either administration of a progestin antagonist (total of six pregnancies, in three bitches) or a luteolytic regimen of prostaglandin F2α -analogue together with a dopamine agonist (total of four pregnancies, in two bitches). The outcomes were evaluated in relation to four control pregnancies in two bitches by assay of serum progesterone, prolactin and relaxin at selected time points or within selected time periods, by ultrasound of conceptuses including measurement of uterine blood flow, and parameters of the blood fibrinolytic system including plasma fibrinogen and plasminogen. The process of embryonic death and conceptus resorption was variable in onset and duration both in bitches that received the progesterone antagonist aglepristone (AGLE) and in those under the luteolytic treatment (cloprostenol combined with cabergoline). Pregnancy termination (death of all embryos or foetuses, respectively) occurred as early as day 29 and as late as day 41 after ov in AGLE-treated bitches, and not earlier than day 37 after ov in luteolytic-treatment bitches. Impending embryonic death was not predicted by changes in relaxin concentration, parameters of the fibrinolytic system, or in the perfusion of small uteroplacental vessels. 相似文献