兽药使用环节存在的问题及对策

经过对兽药生产厂家和经营企业几年的整治,尤其是新<兽药管理条例>和<兽药标签和说明书管理办法>出台后,又经过GMP认证,兽药生产经营市场秩序和经营行为得到了一定的规范.但兽药使用环节中却存在诸多的问题,如:违法使用人用药品;违法使用禁用兽药;不执行休药期规定;未建立台帐等等.这些问题的存在,直接导致了动物产品的安全性问题.对此,笔者分析了兽药使用环节存在问题的原因,并对解决这些问题提出了个人观点.     

正交试验法优化普抗合剂制备工艺

以干浸膏得率和黄芩苷提取率为考核指标,采用正交试验法对普抗合剂水提取醇沉淀制备工艺进行考察.普抗合剂最佳制备工艺方案为加水量10倍,提取2次,每次1 h,55%的乙醇沉淀杂质 .该工艺科学合理,适合于大规模工业生产.     

Root growth,water relations and mineral uptake of young ‘Delicious’ apple trees treated with soil- and stem-applied paclobutrazol

Paclobutrazol (2R,3R + 2S,3S)-1-(4 chlorophenyl)-4,4-dimethyl-2-(1,2,4-trizol-1-yl) pentan-3-ol), at 25, 50 and 150 mg active ingredient, was applied as a soil drench or stem application to 1-year-old ‘Topred Delicious’ apples. Root growth measured as relative root surface area was reduced by both soil and stem applications. There was no significant difference in dry weight of the root tissue. The root-to-leaf-area ratio was significantly increased in paclobutrazol-treated plants.Water relations measured as leaf conductance and leaf water potential were significantly influenced by paclobutrazol. Leaf conductance was higher in paclobutrazol-treated plants when the plants were turgid, as well as under some water stress. Leaf water potential was significantly higher in treated plants.There were no significant differences in the total nitrogen, phosphorus, potassium and magnesium levels found in the leaf or root tissue.     

Ceramide triggers budding of exosome vesicles into multivesicular endosomes

Intraluminal vesicles of multivesicular endosomes are either sorted for cargo degradation into lysosomes or secreted as exosomes into the extracellular milieu. The mechanisms underlying the sorting of membrane into the different populations of intraluminal vesicles are unknown. Here, we find that cargo is segregated into distinct subdomains on the endosomal membrane and that the transfer of exosome-associated domains into the lumen of the endosome did not depend on the function of the ESCRT (endosomal sorting complex required for transport) machinery, but required the sphingolipid ceramide. Purified exosomes were enriched in ceramide, and the release of exosomes was reduced after the inhibition of neutral sphingomyelinases. These results establish a pathway in intraendosomal membrane transport and exosome formation.     

The change of acute phase protein haptoglobin in cattle during spontaneous labor and Caesarean section with or without torsio uteri intrapartum

The change of haptoglobin concentration in cattle with dystocia after torsio uteri which lead to Caesarean section is regarded in contrast to haptoglobin concentrations in cattle at parturitions with undisturbed puerperium and Caesarean section without torsio uteri intra partum. Animals with natural parturition had low haptoglobin concentrations with slight changes, for a slightly increased haptoglobin concentration was seen as physiologic. Also surgical treatment such as Caesarean section did not result in changes of haptoglobin concentration. Thus, the curve of animal patients with anomalies concerning position or with a too large fetus (relatively or absolutly) was nearly identical to the curve of animals with regular parturitions over the first four days after surgery. Not before the fifth day after surgery, a moderate increase of haptoglobin could be observed. Animals with dystocia after torsio uteri intra partum showed significantly higher haptoglobin concentrations in contrast to controls over the time of investigation. The correlation of haptoglobin concentrations in animal patients with torsio uteri bin concentration shortly after surgery an additionally significant increase of haptoglobin concentration could be observed in later fertile cattles but not in later infertile cattle with torsio uteri. In two cows with torsio uteri and ovariohysterectomy haptoglobin concentrations decreased rapidly. Haptoglobin concentration may serve as an indicator for the degree of impairment of the uterus during a parturition as well as a predictor for regenerative potential.     

Epidemiological investigations of bovine Chorioptes mange in Germany

Chorioptic mange in cattle has long been recognised as a common external parasitosis in livestock. In order to evaluate the economic importance of Chorioptes bovis-mange, the seasonal prevalence in several types of husbandry in the states of Germany, location of clinical skin symptoms, procedure of diagnosis, influence on milk or meat production, and treatment especially in dairy farming, 1190 German large animal practicioners have been asked by questionnaires from which 367 responded. This paper gives an update on important epidemiological investigations on bovine chorioptic mange due to this inquiry. Since more than one third of the questioned veterinarians see tail mange often, it is of high importance for farm cattle. Chorioptes mange mainly occurs in dairy cattle stocks, and has especially negative effects on milk production and meat productivity. For treatment of this external parasitosis mainly macrocyclic lactons and pyrethroids are used.