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1.
Flow cytometric sorting technology was used to measure the difference in DNA content between X- and Y-chromosome-bearing spermatozoa in bucks. Spermatozoa were analysed by flow cytometry to characterize X- and Y-chromosome-bearing sperm populations and to quantify the DNA difference between them. Two symmetrical, overlapping and clearly separated peaks, corresponding to X- and Y-bearing spermatozoa, were detected. The difference in fluorescence intensity between the peaks was 4.4 +/- 0.03% without any significant inter- or intra-animal variations. Therefore, the identification and selection of high-purity samples of sperm populations for sex sorting is easier in bucks compared with other domestic species.  相似文献   
2.
High-yielding dairy cows collapsed and died displaying signs of a disturbed central nervous system (muscle tremor, convulsion) and a considerably reduced body condition score. An intense diagnostic screening did not allow to confirm a definite diagnosis. Therefore, further analyses including an evaluation of feeds and feeding were initiated. The herd was fed a total mixed ration (TMR) based on corn and grass silage of moderate nutritive value supplemented with various amounts of chocolate chips. In retrospect, the amount of chocolate chips added to the respective TMR batches could not be quantified. These chips were purchased from a company producing bakery and chocolate products for human consumption and added to the silage and therefore to the TMR in order to increase the energy intake of the animals. Because the TMR, which was fed during the time of the incidence, was no longer available, a sample of a later batch of silage was examined. The amount of chocolate chips was quantified (0.44% per fresh matter), and a theobromine analysis was performed in the chocolate chips of the available batch (69.7 mg/100 g fresh matter). Because of the possible link between chocolate intake and observed signs, an immediate cessation of using the chocolate chips was recommended in addition to an optimisation of the TMR, that is an increase of the energy density. Even though the theobromine intake during the time of the incidence is unknown and information about toxicity of theobromine in ruminants is limited, we suspect that the feeding of chocolate in this case caused all signs including the sudden death of the cows. Further reasons are that no differential diagnoses were established and the problems at the farm stopped after removing the chocolate from the TMR.  相似文献   
3.
To evaluate factors contributing to fertility of thoroughbred mares, data from 3743 oestrous periods of 2385 mares were collected on a large thoroughbred farm in Ireland. Fourteen stallions (mean age 8.3 years; range 4–15 years) had bred 2385 mares (mean age 9.4 years; range 3–24 years). Maiden mares accounted for 12%, mares with a foal at foot for 64%, and barren, slipped or rested mares for 24% of the total. The mean pregnancy rate per cycle was 67.8% (68.6% in year 1 and 66.9% in year 2). Backward stepwise multivariable logistic regression analysis was utilized to develop two models to evaluate mare factors, including mare age, reproductive status, month of foaling, dystocia, month of cover, foal heat, cycle number, treatments, walk‐in status and stallion factors including stallion identity, stallion age, shuttle status, time elapsed between covers and high stallion usage on the per cycle pregnancy rate and pregnancy loss. Old age (p < 0.001) and cover within 20 days post‐partum (p < 0.003) were associated with lowered pregnancy rates. High mare age (p < 0.05) and barren, slipped or rested reproductive status (p = 0.05) increased the likelihood of pregnancy loss. Uterine inflammation or infection, if appropriately treated, did not affect fertility. Only high usage of stallions (used more than 21 times in previous week) was associated with lowered (p = 0.009) pregnancy rates. However, shuttle stallions were more likely to have increased (p = 0.035) pregnancy survival, perhaps reflecting a bias in stallion selection. In conclusion, mare age exerted the greatest influence on fertility; nonetheless, thoroughbreds can be effectively managed to achieve high reproductive performance in a commercial setting.  相似文献   
4.
Porcine endogenous retroviruses (PERVs) are integrated in the genome of all pig breeds. Since some of them are able to infect human cells, they might represent a risk for xenotransplantation using pig cells or organs. However, the expression and biological role of PERVs in healthy pigs as well as in porcine tumours is largely unknown. Since we and others have recently shown overexpression of a human endogenous retrovirus, HERV-K, in human melanomas, we studied the expression of PERVs in melanomas of selectively bred Munich miniature swine (MMS) Troll. This breeding herd of MMS Troll is characterised by a high prevalence of melanomas, which histologically resemble various types of cutaneous melanomas in humans. Several genetic factors have been defined when studying inheritance of melanomas and melanocytic nevi in MMS Troll. Here we show that the polytropic PERV-A and PERV-B as well as the ecotropic PERV-C are present in the genome of all melanoma bearing MMS Troll investigated. Most interestingly, in the spleen, but not in other organs, recombinant PERV-A/C proviruses were found. PERV expression was found elevated in melanomas when compared to normal skin and viral proteins were expressed in melanomas and pulmonary metastasis-derived melanoma cell cultures. During passaging of these cells in vitro the expression of PERV mRNA and protein increased and virus particles were released as shown by RT activity in the supernatant and by electron microscopy. Genomic RNA of PERV-A, -B and -C were found in pelleted virus particles. Although PERV expression was elevated in melanomas and pulmonary metastasis-derived cell cultures, the function of the virus in tumour development is still unclear.  相似文献   
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6.
The molecular analysis of the arbuscular mycorrhizal (AM) symbiosis started at the beginning of this decade. The paper summarises the work of the ‘Laboratorium für Molekulare Genetik arbuskulärer Mykorrhiza’ at the MPI für terrestrische Mikrobiologie in Marburg on three major topics. Firstly, the plant response to the mycorrhizal colonisation was analysed using both, targeted and non‐targeted approaches. As an example, the localisation of the gst1 mRNA in potato mycorrhiza is shown. Second, molecular techniques were established to analyse gene expression of the fungal partner of the symbiosis. We present a differential RNA display analysis of spore germination in two AM fungi and the cloning of a gene from Glomus mosseae that shows expression at all stages of the fungal life cycle. In the last part, we introduce the work we are carrying out with a new root endophytic fungus, Piriformospora indica. Infection experiments on maize showed that despite the fungus performs as a root necrotroph, it has a positive effect on plant growth.  相似文献   
7.
Pythiosis (caused by the aquatic oomycete Pythium insidiosum) is a devastating and often fatal cause of either severe transmural gastroenteritis or locally invasive subcutaneous disease in dogs living in the southeastern United States. Although early diagnosis is essential for successful treatment, tools available for this task are limited. Therefore, we developed and evaluated an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-P insidiosum antibodies in canine serum. A soluble mycelial extract of P insidiosum was utilized as antigen in the ELISA, which was used to evaluate serum from 43 dogs with pythiosis, 8 dogs with lagenidiosis (another canine oomycosis), 16 dogs with nonoomycotic fungal or algal infections, 22 dogs with nonfungal gastrointestinal or skin disease, and 55 healthy dogs. Results were expressed as percent positivity (PP) relative to a strong positive control serum run on each plate. Medians and ranges for each of the 5 groups were as follows: pythiosis (81.7%, 50.6-98.5%), lagenidiosis (17.3%, 11.3-29.2%), other fungal or algal infections (8.2%, 4.7-15.4%), nonfungal gastrointestinal or skin disease (6.2%, 3.9-20.7%), and healthy dogs (6.7%, 3.0-15.2%). When using a cutoff value of 40% PP, the sensitivity and specificity of the ELISA both were 100%. In addition, ELISA values measured after successful surgical therapy in 2 dogs showed a decrease of anti-P insidiosum antibody concentrations into the normal range as early as 2 months after treatment. We conclude that the ELISA is a sensitive and specific test for the diagnosis of canine pythiosis, and may be a useful tool for monitoring response to medical or surgical therapy.  相似文献   
8.
Objective To characterise the effects of delmadinone acetate on the pituitary-adrenal axis, glucose tolerance and growth hormone concentration in normal male dogs and dogs with benign prostatic hyperplasia.
Design A prospective study involving nine normal male dogs and seven with prostatic hyperplasia.
Procedure Delmadinone acetate was administered to six normal male dogs and seven dogs with benign prostatic hyperplasia at recommended dose rates (1.5 mg/kg subcuta-neously at 0, 1 and 4 weeks). Three normal controls received saline at the same intervals. Blood concentrations of ACTH, cortisol, glucose, insulin and growth hormone were measured over 50 days. Intravenous glucose tolerance and ACTH response tests were performed before and after treatment in the nine normal animals.
Results A substantial suppression of basal and 2 h post-ACTH plasma cortisol secretion was demonstrated after one dose in all dogs given delmadinone acetate. Individual responses after the second and third administration varied between recovery in adrenal responsiveness to continued suppression. Plasma ACTH concentration was also diminished after one treatment. No effects were evident on glucose tolerance or serum growth hormone concentrations.
Conclusion Delmadinone acetate causes adrenal suppression from inhibition of release of ACTH from the pituitary gland. Treated dogs may be at risk of developing signs of glucocorticoid insufficiency if subjected to stressful events during or after therapy. Neither glucose intolerance nor hyper-somatotropism seems likely in male dogs given delmadinone acetate at the recommended dose rate, but the potential for excessive growth hormone secretion in treated bitches remains undetermined.  相似文献   
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10.
This case report describes the occurrence of persistent penile erection in a breeding stallion that occurred while the horse was under inhalant anesthesia for a carpal arthroscopy. The horse had no history of breeding problems, and no abnormalities were detected on physical examination, complete blood count, or serum chemistry tests performed prior to surgery. Anesthesia was induced with guaifenesin and ketamine after sedation with xylazine and was maintained with isoflurane in 100% oxygen. Penile erection developed approximately 35 minutes after induction and persisted for over 2 hours despite various physical and pharmacological attempts to alleviate it (massage, cold compresses, intravenous benztropine administration, and intracavernosal phenylephrine). Successful resolution of the erection was obtained by cannulation and drainage of blood from the corpus cavernosum and subsequent irrigation with heparinized sterile saline and infusion of phenylephrine in the corpus cavernosum. The detumescent penis was placed back into the sheath, and purse string sutures were placed in the sheath to ensure the penis would remain inside the sheath during recovery. The stallion's recovery from anesthesia was uneventful, the sutures were removed, and the horse was fitted with a penile sling to prevent additional edema or trauma. The stallion recovered completely from the persistent penile erection. Semen was collected 6 days after the event, and he returned to normal pasture breeding 6 weeks after surgery.  相似文献   
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