首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 2 毫秒
1.
Neutrophil migration into the uterine lumen in response to the intrauterine infusion of both an oyster glycogen suspension and a bacteria-free filtrate obtained after incubation of Actinomyces pyogenes in cooked meat medium was studied in 4 cows at estrus (Day 0) and at diestrus (Day 10). In addition, the same chemoattractants were used in 5 other cows following bilateral ovariectomy and after parenteral treatment with exogenous estradiol 17beta and progesterone in oil. Large numbers of cells (average viability >85%, purity 95%) were obtained with both chemoattractants. In cyclic and bilaterally ovariectomized cows bacteria-free filtrate produced a greater migratory response than oyster glycogen, and the differences were significant (P < 0.01 and P < 0.002, respectively). On Day 10 of the estrous cycle a higher number of neutrophils was recovered than on Day 0 following infusion of oyster glycogen and bacteria-free filtrate, and again the differences were significant (P < 0.003 and P < 0.001, respectively). Following treatment of ovariectomized cows with estradiol and progesterone, greater response was observed for progesterone than for estradiol after oyster glycogen and bacteria-free filtrate treatment with significant differences (P < 0.002 and P < 0.003, respectively). Both chemoattractants produced adequate numbers of viable neutrophils suitable for subsequent evaluation of their function in vitro. The increased neutrophil response induced by progesterone, both in normal cyclic cows and after ovariectomy following progesterone treatment, may be a compensatory one due to reduced neutrophil phagocytosis and bactericidal activity or to the suppression of other uterine defense mechanisms, since this response is inconsistent with the long-recognized observation that the uterus of the cow is more susceptible to infection in diestrus than in estrus.  相似文献   

2.
E C Mather 《Theriogenology》1975,3(3):113-119
The hydrogen ion concentration of the fluids of the uterine lumen was determined in six mature cows at 2 day intervals throughout the normal oestrous cycle. Determinations were made with a pH cardiovascular catheter electrode inserted into the uterus and a reference electrode placed externally over the sacrum of the cow. The grand mean of the determinations was pH 7.30. The pH changed with the period of the cycle. The lowest values occurred within 2 days prior to ovulation and a second low mean value occurred about 10 days following ovulation.  相似文献   

3.
4.
The effect of circulating passive antibody on immunity to bovine rotavirus infections in neonatal calves was investigated. In the first experiment, rotavirus antibody titers in the small intestinal lumina of 5- and 10-day-old calves with a wide range of serum rotavirus antibody titers were determined. Neutralizing antibody was present in the small intestinal lumina in titers that correlated with the calves' serum titers (r = +0.84, P less than 0.01). Immunoglobulin G1 was the predominant isotype of intestinal luminal rotavirus antibody. Calves not fed colostrum during the absorptive period lacked rotavirus antibody in circulation and in the intestinal lumen at 7 days of age, even when they were fed large volumes of colostrum with a high rotavirus antibody titer at 48 h after birth. Therefore, rotavirus antibody is not retained in the intestinal lumen for 5 days following a colostrum meal, and the luminal antibody in the 5- and 10-day-old seropositive calves were probably derived from circulating antibody. In a second experiment, calves were passively immunized by subcutaneous injection of colostral whey with a high immunoglobulin G1 rotavirus antibody titer and challenged with virulent bovine rotavirus 48 h later. The passively immunized calves were protected from rotavirus infection and diarrhea compared with calves with comparable serum immunoglobulin concentrations but with lower serum rotavirus with lower serum rotavirus antibody titers. The results of these experiments indicate that circulating immunoglobulin G1 antibody appears in the gastrointestinal tract of neonatal calves and that circulating rotavirus antibody can prevent infection and diarrhea after rotavirus challenge.  相似文献   

5.
Suspensions of india ink or gonococci were inoculated into the murine uterus through the cervix with a simple plastic vaginal speculum and a 23 gauge blunted needle. The inoculated suspensions were distributed throughout both uterine horns, cervix, and vagina, but did not flow into the peritoneal cavity. This method avoided surgical stress as well as being simple, fast, and reproducible.  相似文献   

6.
7.
A study using 11 healthy, mature Holstein-Friesian heifers was designed to determine whether 1) H. somnus induces gross and/or histopathological changes of the uterine tract and embryos, 2) H. somnus has a short and/or long-term effect on the ovarian activity, 3) prior exposure to H. somnus would modulate the effect of a second exposure to the organism. Superovulated heifers were artificially iseminated 12 and 24 h after standing estrus using high-quality, Haemophilus-free semen from a single ejaculate of one bull. Control heifers (Group 1, n = 2) were infused by intrauterine route, 12 h after the second insemination, with 10 ml of 0.85% sterile phosphate buffered saline (PBS) as a placebo. The treatment heifers were exposed by intrauterine infusion, 12 h after the second insemination, to approximately 1.5 x 10(9)H. somnus organisms (Iowa strain 1229) suspended in 10 ml of 0.85% sterile PBS. Group 2 (n = 2) treatment heifers were exposed 21 d prior to embryo recovery; Group 3 treatment heifers (n = 3) were exposed 5 mo prior to embryo collection; and Group 4 treatment heifers were exposed twice, 5 mo apart with the second exposure 21 d prior to embryo recovery. All animals were slaughtered and the whole genital tract was removed for pathological examination and embryo recovery. There were minimal pathological changes in the uterus. However, H. somnus significantly affected (P 相似文献   

8.
9.
Systematic evaluations of new combinations of antibiotics for the control of bovine mycoplasmas, ureaplasmas, Campylobacter fetus subsp. venerealis and Haemophilus somnus in a bovine frozen semen process were made. These organisms were standardized to 10(5) to 10(6) colony forming unit (CFU) and inoculated into each ml of raw semen. Antibiotics in a final volume of 0.02 ml were added to each ml of the raw semen and were contained at the same concentration in the nonglycerol portion of the extenders (whole milk, 20% egg yolk citrate, 20% egg yolk tris, Plus-X, and 28% egg yolk tris). The combination of gentamicin (500 ug/ml) tylosin (100 ug/ml) and Linco-Spectin (300/600 ug/ml) was more effective for the control of mycoplasmas and ureaplasmas and equally effective for the control of C. fetus subsp. venerealis and Haemophilus somnus than the standard combination of penicillin, dihydrostreptomycin and polymyxin B sulfate.  相似文献   

10.
11.
12.
13.
Purulent exudate from the uteri of two nonlactating Holstein cows with chronic pyometra was aspirated into a 50 cc syringe via an artificial insemination pipette. The two fractions were mixed, cultured, divided into 14 equal parts and infused into the uteri of 14 other nonlactating cows. All recipient cows had had at least one estrous cycle of normal length and were in the early luteal phase (day 4-8). On days 3, 7, 14 and 21 following infusion, the reproductive tract was examined per rectum, content of the uterus was cultured for bacteria, and endometrial condition was assessed by biopsy and histopathology. The lengths of the estrous cycles of the recipient cows were shortened P < 0.01) from 21 +/- .5 days to 13.3 +/- 1.4 days. Estrus was determined by palpation per rectum and/or observation. Over the experimental period, Pasteurella sp., Corynebacterium pyogenes and other diphtheroids were isolated from 64, 57 and 86% of the cows, respectively. An inflamed endometrium was associated (P<0.10) with the presence of Pasteurella sp. on day 7 following infusion. No other associations were found when the presence of bacteria, vaginal discharge, or short estrous cycles were compared. The infusion of purulent exudate apparently irritated the endometrium causing an early return to estrus rather than causing pyometra. It is probable that postpartum and lactational stress are involved in the development of pyometra.  相似文献   

14.
Laboratory studies of arenaviruses have been limited to parenteral routes of infection; however, recent epidemiological studies implicate virus ingestion as a natural route of infection. Accordingly, we developed a model for oral and gastric infection with lymphocytic choriomeningitis virus to enable studies of mucosal transmission and vaccination by this additional route.  相似文献   

15.
Commercial killed bovine respiratory syncytial virus (K-BRSV) and formalin-inactivated BRSV (FI-BRSV) tend to induce Th2-type immune responses, which may not be protective and may even be detrimental during subsequent exposure to the virus. In this study we assessed the ability of CpG oligodeoxynucleotides (ODNs) to aid in the generation of effective and protective BRSV-specific immune responses. Mice were immunized subcutaneously with FI-BRSV formulated with CpG ODN, Emulsigen (Em), CpG ODN and Em, or non-CpG ODN and Em. Two additional groups were immunized with K-BRSV or K-BRSV and CpG ODN. After two vaccinations, the mice were challenged with BRSV. FI-BRSV induced Th2-biased immune responses characterized by production of serum immunoglobulin G1 (IgG1) and IgE, as well as interleukin-4 (IL-4), by in vitro-restimulated splenocytes. Formulation of FI-BRSV with CpG ODN, but not with non-CpG ODN, enhanced serum IgG2a and IFN-gamma production by splenocytes, whereas serum IgE was reduced. Although the immune response induced by K-BRSV was not as strongly Th2 biased, the addition of CpG ODN to this commercial vaccine also resulted in a more Th1-type response. Furthermore, the addition of CpG ODN to the BRSV vaccine formulations resulted in enhanced neutralizing antibody responses. Significant production of IL-5, eotaxin, and eosinophilia was observed in the lungs of FI-BRSV- and K-BRSV-immunized mice. However, IL-5 and eotaxin levels, as well as the number of eosinophils, were decreased in the mice vaccinated with the CpG ODN-formulated vaccines. Finally, when formulated with CpG ODN, both FI-BRSV and K-BRSV significantly reduced virus production after challenge with BRSV.  相似文献   

16.
Murine polyomavirus is used in various models of persistent virus infection. This study was undertaken to assess the spatial and temporal patterns of MPyV infection in the brains of immunocompetent (BALB/c) and immunocompromised (KSN nude) mice. MPyV was stereotaxically microinfused into the brain parenchyma, and the kinetics of infection were examined by quantitative PCR. In BALB/c mice, the amount of viral DNA in the brain peaked at 4 days p.i. and then rapidly diminished. In contrast, MPyV DNA levels increased up to 4 days and then gradually decreased over the 30‐day observation period in the brain of KSN mice. In both mouse strains, viral DNA was readily detected around the sites of inoculation from 2 to 6 days p.i., and continued to be detected for up to 30 days p.i. In addition, MPyV infection did not lead to a drastic induction of innate immune response in the brains, nor did MPyV‐inoculated mice show any signs of disease. These results indicate that MPyV establishes an asymptomatic long‐term infection in the mouse brain.  相似文献   

17.
18.
The technique and the equipment necessary for the transcervical intrauterine injection in trained, ovariectomized pigs is detailed. Experimental groups of 14-16 week-old animals are recruited from German landrace litters with large numbers (4-9) of females. A silastic tubing containing a crystalline suspension of estradiol in propylene glycol is subcutaneously implanted behind the right ear. Ovariectomy and the detachment of the left uterine horn from the cervix are performed 7-10 days later. The animals are then kept for 6-7 weeks in ventilated stables, heated to 20 degrees C in wintertime, with 12 hr light dark cycle, free access to water and semi-ad libitum supplies of pelleted standard feed. The silastic implant gives rise to plasma levels of 8-12 pg estradiol/ml and still contains crystalline sediments when removed before the experiment. The manipulations for the transcervical, intrauterine instillation of solutions, imitating the reproductive action of the boar, are practiced daily for at least one week. The animals learn quickly to enter a restraining box, which is facilitated by the simultaneous offering of pellets drenched with root beer. The intrauterine injections proceed thereafter without any signs of stress from the animals. Stress is also avoided during slaughter by unexpected electric stunning on leaving the box, followed by exsanguination. Uteri are quickly excised and chilled in crushed ice until processed. One to two grams of endometrium cells can be harvested by curettage from each, treated and untreated (detached) horn. The Mariensee model allows for defined kinetic analyses of treated cells and provides nontreated controls from the same animal. It combines the advantages of in-vivo and in-vitro experiments.  相似文献   

19.
We present a model of cell motility based on emigration of neural crest cells into the neural tube lumen under in vitro conditions (10% fetal calf serum or YIGSR) that inhibit their normal emigration from the base of the neuroepithelium into surrounding extracellular matrix (ECM). Ultrastructural observations reveal that cells lining the lumen are joined by zonulae adherentes (ZA), which are points of strong intercellular attachment, and thereby serve as markers for fixed regions of plasmalemma and cortical actin. Three major observations of the relationship of cells to the ZA support the "fixed cortex" model of mesenchymal cell migration. First, cells extend apical cell processes past the ZA into the lumen. To do this, they must make new apical plasmalemma and actin cortex that the endoplasm slides into. Second, elongated cells are observed in the lumen that are still attached via ZA to the neuroepithelium. This indicates that all of the endoplasm finally slides past the ZA. Third, numerous cytoplasmic pieces, often attached to each other and to the neuroepithelium via ZA, are found at the site where cells appear to have detached from the epithelium after entering the lumen. Since the ZA is fixed in location, the endoplasm must have slid past it into newly manufactured anterior cortex and plasmalemma, with the trailing end of the cell finally snapping off. The "fixed cortex" theory of cell migration agrees with existing data in that it predicts the polarized insertion of new plasmalemma and actin at the leading end of the cell, but it differs significantly from existing theories of mesenchymal cell migration in that it states that the cell surface remains firmly attached to the substratum while the myosin-rich endoplasm slides past it.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号