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1.
Persistent dermatomycosis (ringworm) caused by Trichophyton verrucosum affected 20 dairy calves aged between 3 months and 1 year and housed together. The infection also spread to 2 animal attendants working among the calves. The major clinical lesions observed on the affected calves were extensive alopecia and/or circumscribed thick hairless skin patches affecting the head, neck, flanks and limbs. The observed lesions persisted for more than 17 weeks and most of the calves did not respond to topical treatment with various anti-fungal drugs within the anticipated period of 9 weeks. Two animal attendants developed skin lesions that were circumscribed and itchy and there was good response to treatment following the application of anti-fungal skin ointment. Although ringworm in dairy animals in Kenya has not previously been associated with spread to humans, the potential is evident from this report.  相似文献   

2.
Systemic infection of the cat with the yeast-like fungus, Cryptococcus neoformans , is reviewed. Seven cases of the disease are reported, two of which were treated unsuccessfully with the anti-fungal agent, amphotericin B.  相似文献   

3.
通过提取水稻叶片基因组DNA,设计PCR扩增特异引物,克隆单子叶特异表达启动子Ac-tin1基因,与T载体连接,转化E.coliDH5α,得到重组子,经酶切和序列分析鉴定,该片段分子大小为1238bp,通过序列对比分析发现与已发表的Actin1碱基序列有99.60%的同源性。特异启动子基因驱动的抗真菌肽(AFP)基因植物表达载体,就可以进行早熟禾黑麦草等单子叶牧草的遗传转化,为单子叶牧草和草坪草的抗真菌病研究提供方法。  相似文献   

4.
A case of feline cutaneous phaeohyphomycosis due to Cladophyalophora bantiana is described. The cat was presented with breathing difficulty and a swollen, ulcerated nodule on the dorsal nose and left nostril. Histological examination of the nodule revealed a cystic granulomatous dermatitis characterised by neutrophils, macrophages and giant cells. Pigmented, yeast-like fungus cells and hyphal elements were easily identified in haematoxylin-eosin stained tissue sections. Cladophyalophora bantiana was isolated from a tissue specimen. This organism, primarily known to cause cerebral infection in humans and cats, only rarely causes cutaneous infection. Despite anti-fungal chemotherapy two relapses occurred. The cat was feline immunodeficiency virus- and feline leukemia virus-negative and even if the owner was unaware of trauma, the hypothesis of wound contamination is the most likely.  相似文献   

5.
Seventy-two pruritic dogs were fed one of four diets controlled for n-6:n-3 fatty acid ratios and total dietary intake of fatty acids. Multiple parameters were evaluated, including clinical and cytological findings, aeroallergen testing, microbial sampling techniques, and effects of an anti-fungal/antibacterial shampoo and ear cleanser. Significant correlations were observed between many clinical parameters, anatomical sampling sites, and microbial counts when data from the diet groups was combined. There were no statistically significant differences between individual diets for any of the clinical parameters. The importance of total clinical management in the control of pruritus was demonstrated.  相似文献   

6.
Lufenuron is a benzyl-urea phenol compound that inhibits chitin synthesis and is used as an insecticide. Its efficacy in the therapy of dermatophytosis in dogs and cats was evaluated in several clinical studies, with contradictory results. We assessed the in vitro susceptibility of dermatophytes isolated from dogs and cats to lufenuron, and the clinical response of skin lesions to the drug. Dermatophyte cultures isolated from clinical cases were exposed to lufenuron by three different methods: direct application and application of whole blood or subcutaneous tissue samples obtained from a lufenuron-treated healthy dog. No inhibition of dermatophyte growth was observed in any of the samples after 1 week of incubation. Eight dogs and six cats with skin lesions were included in the in vivo survey. Results indicated that six of seven skin lesions that were diagnosed as being caused by dermatophytes did not respond to lufenuron whereas six of seven skin lesions that were not caused by dermatophytes improved. We concluded that lufenuron, in the way it was administered in this study, had no inhibitory activity on dermatophytes in vitro or in vivo and its clinical use as an anti-fungal agent is questionable. An immunomodulatory effect of the drug is, however, possible.  相似文献   

7.
张建飞 《中国畜牧兽医》2012,39(10):225-228
随着人类生活水平和健康水平的提高,绿色食品(肉、蛋、奶)的需求越来越大,消费者更关心食品的安全性。世界各国,尤其是欧洲、日本等发达国家在大力开展研究药物饲料添加剂的代用品。积极鼓励和倡导绿色安全饲料添加剂的研究和推广,微生态制剂受到世人的瞩目。但是,科学家们仍需进一步探讨该类产品的稳定性和连续性与生理、生化、营养各方面的关系。国内外的学者正在致力于细菌素(抗菌肽(antibacterid peptides)或多肽抗生素(peptide antibiotics))的研究。随着国内外研究的进展和深入,人们相继发现这类多肽不但具有抗细菌、抗真菌的作用,还具有抗寄生虫、病毒、癌细胞等功能,在医药学和食品保鲜技术上,成为研究的热点。在食品安全的今天,细菌素作为一种高效安全的饲料添加剂正在成为可能,需要加大力度进行研究和开发,细菌素的基因工程、蛋白质工程及分子筛选法将继续研究和突破,最终真正能够替代抗生素成为人类生产绿色食品。  相似文献   

8.
The antispermatongenic effects of furazolidone on the testes of mature Wistar rats were investigated using histological and morphometric methods. The sections showed a varying degree of depopulation of the germinal epithelium, a shrinking and a deformation of the Tubuli contorti, and an enlargement of the intertubular lymphatic sinuses. The strain led to a standstill in the spermatogenesis at the primary-spermatocyte stage. After administering furazolidone, the following results could be seen: – a weightloss of up to 42.1% and a decrease in testes volume by up to 30.2% – a decrease in the volume of the nuclei of the Leydig-cells by up to 51.6% – a reduction in the diameter, perimeter and area covered by Tubuli seminiferi contorti of up to 33.5%, 30.8%, and 53.4%, respectively – an increase in the number of Tubuli seminiferi contorti per mm2 by up to 44.8% – a decrease in the percentage of Tubuli seminiferi contorti of the total testes tissue by up to 39.1%  相似文献   

9.
Tagging and elimination of plasmids in Salmonella of avian origin   总被引:2,自引:0,他引:2  
This study compared the effectiveness of a number of procedures designed to label and eliminate plasmids that may play a role in virulence in Salmonella. Twenty strains of Salmonella of 9 serovars were subjected to 3 methods for labelling plasmids with transposons. Strains containing labelled and unlabelled plasmids were exposed to physical and chemical curing agents. Plasmids in 9 of 20 strains of Salmonella were tagged by conjugation with a donor Escherichia coli containing a temperature-sensitive RP4 plasmid that carried the Tn1 transposon. Plasmids in 2 of 5 strains of Salmonella were labelled by conjugation with a donor E. coli that contained a F' tslac::Tn5 plasmid. Transduction of Salmonella with a P22 bacteriophage that carried a temperature-sensitive Tn10 transposon resulted in chromosomal insertion of Tn10 in 2 of 10 strains. Use of chemical curing agents resulted in curing of plasmids in only 6 of 17 strains. Two strains were cured by ethidium bromide, two by a combination of ethidium bromide and novobiocin, two by a combination of imipramine and methylene blue, and none by acridine orange, novobiocin, sodium dodecyl sulfate or rifampicin. In contrast, plasmids in 14 of 17 Salmonella strains were eliminated by incubation at 45.5 degrees C.  相似文献   

10.
Treatments involving a full growing season rest in alternate years, half a growing season rest (late season) in alternate years and no rest were applied to veld grazed by sheep or cattle at similar stocking rates. Residual effects of the treatments on veld vigour were determined by measuring species regrowth during the season following treatment application, compared to ungrazed controls. The vigour of veld grazed by sheep declined rapidly relative to veld grazed by cattle. The vigour of palatable species was severely impacted, vigour of intermediate species was variably impacted and vigour of unpalatable species increased dramatically on veld grazed by sheep. Similar trends occurred in veld grazed by cattle, but to a lesser degree. Resting was beneficial for vigour recovery in both sheep and cattle treatments but it seems that the grazing treatment between rests has an over-riding influence on veld vigour. The veld grazed by sheep remained at a lower productivity level than veld grazed by cattle. Principles related to resting and the impacts of sheep and cattle grazing are briefly discussed with a view to formulating management strategies.  相似文献   

11.
The ELISA we developed was able to determine the antigen content and was suitable for a potency test, and we described a relative potency assay method which determines the potency of test vaccines by comparing the ELISA value of a test vaccine to that of a reference vaccine. In the present study, we standardized the reference vaccine used for determining the potencies of test vaccines, and established a potency test by ELISA. We evaluated the proposed reference vaccine by the neutralizing antibody responses in dogs after vaccination, by the challenge protection test in guinea pigs (GP potency test), which is the earlier official potency test used in Japan, and by the NIH potency test, which is widely used throughout the world. The results showed that a 4-fold dilution of the proposed reference vaccine induced sufficient immunity in dogs. A 3-fold dilution of the proposed reference vaccine passed the GP potency test. The international units (IU) calibrated by the NIH potency test were 3.7 IU/dose. From the results and the WHO recommendation that veterinary rabies vaccines should have a potency of at least 1.0 IU/dose, we determined to dilute the proposed reference vaccine by 3 fold and regarded it as the reference vaccine. Finally, we confirmed that there is a good agreement between the results of the potency test by ELISA and the results of the GP potency test. The establishment of the potency test by ELISA has made it possible to monitor the potency in the production process and has contributed to the stable production of the vaccine.  相似文献   

12.
Hormonal involvement in the regulation of immune events was studied by exposing calves to cold air (-15 C) for 12 hours or by implanting animals with a growth promotant (xeranol) that is known to affect plasma hormone concentrations. Cold exposure significantly reduced serum IgM concentration by 23%, increased expression of tuberculin reactions to purified protein derivative by 60%, and augmented contact-sensitivity reactions to dinitrofluorobenzene by 31%. There was also a significant increase in plasma cortisol and insulin values and a reduction in growth hormone and prolactin values in cold-exposed calves. The cold-induced increase in contact reactions and plasma insulin was higher in xeranol-implanted calves, but the increase in plasma cortisol concentration caused by cold exposure tended to be reduced by the xeranol treatment. These data demonstrate that cold exposure alters immune reactions of calves and that these changes in immune events are associated with changes in a variety of plasma hormones. These results also indicate that it may be possible to augment immune reactions in vivo by appropriate hormonal modulation.  相似文献   

13.
The injection of chickens with Escherichia coli endotoxins immediately produced a 50 per cent rise in plasma caeruloplasmin activity which was attributed to the release of the protein from liver cell. This was followed by a fall in activity, which was probably due to a fall in activity, which was probably due to a stabilising effect of adrenocortical hormones on the cell membranes, and then by a five-fold increase. The results of experiments with cycloheximide, adrenocorticotrophin, beta-methasone and reserpine indicated that the third phase of the response reflected increased synthesis in the liver which was partly induced by adrenal hormones. It increased with the dose and was not elicited by the particulate nature of the toxin preparation or by its lipid and polysaccharide components.  相似文献   

14.
Studies were undertaken to determine the influence of repeated revaccination on the immune response in immuno-competent turkeys as measured by humoral antibody and resistance to challenge. Protection was better in turkeys given the LaSota spray vaccine at 4 weeks and 30 days later than in turkeys given one vaccination by spray or intramuscular route or exposed 4 times at 10-day intervals by the aerosol route. The anamnestic response, as measured by the HI tests to revaccination with the same immunogen, was not evident by the 3rd day postrevaccination but was observed on the 7th day. The interval between primary and secondary vaccination was found to be important to a true and optimal anamnestic response. Response was greater, however, in vaccinated turkeys exposed to VVND, a more virulent virus antigenically different from the vaccine strain. Exposure to LaSota vaccine by the intramuscular route gave a poorer HI response than LaSota given by aerosol.  相似文献   

15.
Experiences in a large-scale blood sampling was the cause for reflections about the reason of sudden deaths of pigs. The one-sided breeding of pigs in order to get a high lean meat content, the ability to grow rapidly and to put on weight causes susceptibility to exertional myopathy. In addition, in modern housing systems pigs grow up in an environment without any stimulus, which results in emotional stress, if the pigs get suddenly in a close contact to man. Therefore a routinely operation such as taking blood causes an abnormal acceleration of glycolysis and the development of lactacidosis and sometimes a circulatory insufficiency up to sudden death. The metabolic acidosis, which is of breeding origin and arises from stress, often is strengthened by pneumonia in fattening herds caused by faulty husbandry, high animal concentration, stall climate and a high risk of infection. Because of this the metabolic acidosis cannot be compensated for by respiration. The high number of sudden deaths caused by lactacidosis and cardiac shock (fattening period: 1-12%, transport to slaughter: 0.4%, and 0.45% in the own investigation into blood sample taking from fattening pigs [weight: 80-110 kg]) emphasizes the problem. The exertional myopathy is not only characterized by sudden death but also by poor meat quality due to PSE. From the point of view of animal welfare as well as from the point of view of the consumer it is desirable to change the aim of breeding, especially by reducing lean meat content as well as to improve the type of husbandry.  相似文献   

16.
Rainbow trout, caught in a pond 25, 45 and 48 days from releasing, were studied for histopathological changes. Protozoan activity destroys the basal matter of the hypertrophic cartilage. The chondral tissue around plasmodium reacts by showing an increased basophilia and by chondrocytal reaction. The plasmodia tend to spread spherically, but the spreading is prevented by compact bone, connective tissue, or hardened cartilage with flattened chondrocytes. One host can bear one plasmodium or more plasmodia, up to the possibility of a generalized process. The host organism reacts to the destructive changes caused by the protozoan by letting its connective tissue cells grow into the cavities produced by the protozoan, into the plasmodia of the protozoan and into the destruction line; thus the protozoan is separated from the nutrition base. The connective tissue enters the lesion via a hole in compact bone or via a fissure between bone and cartilage. Circulation and blood elements were not found to be present in the penetrating connective tissue. The bone tissue reacts to the presence of the protozoan by thickening the periosteum. Mature spores in the lesions by the protozoan are reduced with host age.  相似文献   

17.
The purpose was to analyse the economic consequences of postponed first insemination of cows in dairy herds with different reproduction management, and to analyse the sensitivity of the results to a further decrease in beef prices, using a model simulating production and health in a dairy cattle herd. Three different period-to-first-insemination scenarios were analysed. Period to first insemination was defined as days post partum for initiating insemination at observed heat. The three scenarios consisted of a short period to first insemination (70 days for primiparous and 35 days for older cows), a 70 days postponed first insemination of primiparous cows and a scenario with 70 days postponed first insemination for all cows. At a 70 days postponed first insemination for primiparous cows a decrease in annual herd profit of 1% were found. A 70 days postponed first insemination for all cows led to a decrease in annual herd profit by 3% at good reproductive efficiency and 4% at poor reproductive efficiency. The herd profit was calculated as the profit to cover labour costs and fixed costs. Postponed inseminations might reduce labour per cow-year. The reduction in labour per cow-year need to be 3.2 h at good reproductive efficiency and 4.3 h at poor reproductive efficiency to counterbalance the reduction in herd profit by postponing first insemination for all cows by 70 days. In a situation with a 50% decrease in beef prices in a herd constrained by a milk quota (optimising profit per kg milk) herd profit was increased by 0.8% at good reproductive efficiency and 0.3% at poor reproductive efficiency by postponing first insemination for all cows by 70 days.  相似文献   

18.
Protein kinase C (PKC) is a phosphotransferase activated by diacylglycerols, phospholipids and Ca(2+), that regulates a wide variety of biological functions by phosphorylating multiple protein substrates such as annexin I. Annexin I is a phospholipid/Ca (2+)-binding protein distributed in various tissues, including the mammary gland, and is thought to mediate the anti-inflammatory actions of glucocorticoids by inhibiting phospholipase A(2). Melittin, a phospholipase A(2) activator in bee venom, is known to inhibit PKC activity when lysine-rich histone is used as the substrate. The purpose of the present study was to examine whether phosphorylation by PKC of annexin I from cow mammary gland was inhibited by melittin. Melittin inhibited annexin I phosphorylation by PKC in a dose-dependent manner, and its IC(50) value (concentration causing 50% inhibition) was 0.8 microM. The phosphorylation of annexin I was also inhibited by the amphiphilic polypeptides mastoparan and polymyxin B, and their inhibitory effects were comparable to that of melittin. The surface-inactive polypeptide bacitracin was less effective. The inhibition by melittin was effectively reversed by the excess addition of phosphatidylserine, but not distinctly by 1-oleoyl-2-acetyl-sn-glycerol or Ca(2+), suggesting that melittin inhibited the phosphorylation of annexin I by interacting with phosphatidylserine. The inhibition by melittin of PKC phosphorylation of annexin I seems to be pathophysiologically important, because a melittin-like phospholipase A(2)-stimulatory protein is present in bovine endothelial cells.  相似文献   

19.
Redgut is a condition of sheep characterised by sudden death. Post-mortem findings are reddened small and large intestines, which are usually displaced. Sheep are predisposed to the condition by a combination of circumstances, including a small rumenoreticulum because of the nature of the feed (usually highly digestible forage), and increased large intestinal size and function. To accommodate this, and because there is not a large rumenoreticulum to stabilise the gut position, the intestinal mass moves to an unstable position in the peritoneal cavity. Some unknown event precipitates a further change in intestinal position, resulting in accidental torsion of the intestinal mass, with resultant obstruction of the mesenteric blood vessels and death from shock.

The condition can be prevented by careful attention to feeding regimes that prevent development of the predisposing feature of small forestomachs and an oversized large intestine, resulting in a displaced intestinal mass. This is achieved by intermittent grazing of “dangerous” pastures.  相似文献   

20.
In an outbreak of foot-and-mouth disease (FMD) it is important to identify animals at risk from airborne virus. Investigations have been carried out over the years to determine the dose required to infect cattle, sheep and pigs by the intranasal route. This paper reviews the results of investigations for animals which have been infected by instillation or spraying a virus suspension into the nostrils or by exposure to affected animals through a mask or by indirect contact. The lowest doses were found by use of a mask. With virus from affected pigs given through a mask, doses of 18 infectious units (IU) in cattle and 8 IU in sheep were found to cause infection and give rise to lesions. Overall, cattle required the least amount of virus followed by sheep. Pigs required a dose of 22 IU to cause infection and a dose of 125 IU to give rise to lesions. In many experiments pigs failed to become infected. With all three species the dose varied with the individual animal and the virus strain. For modelling previous outbreaks and in real time, a dose of 8 IU or 10 and 50% infectious doses (ID50) could be used where cattle and sheep were involved. Experience in the field, combined with the results from experiments involving natural infection, indicate that pigs are not readily infected by the intranasal route. However, for modelling purposes a dose of about 25 IU should be used with care. Investigations are needed to determine doses for virus strains currently in circulation around the world. In addition, the nature of the aerosol droplets needs to be analysed to determine how the respective amounts of infective and non-infective virus particles, host components and, in later emissions, the presence of antibody affect the survival in air and ability to infect the respiratory tract. Further work is also required to correlate laboratory and field findings through incorporation of the doses into modelling the virus concentration downwind in order that those responsible for controlling FMD are provided with the best available assessment of airborne spread. Finally, the doses found for infection by the intranasal route could be applied to other methods of spread where virus is inhaled to assess risk.  相似文献   

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