The intensity of resistance by mature Merino ewes against Haemonchus contortus and Tichostrongylus colubriformis in single-species and combined-species infection

Three-year-old, non-lactating and non-pregnant Merino ewes, raised on pasture under a program of strategic treatment with anthelmintic and found to be extremely resistant to "trickle" infection with Haemonchus contortus, were given single-dose infections with either H. contortus or Trichostrongylus colubriformis or both species together. The purpose was to ascertain the intensity of protective immunity against the 2 parasites in sheep with immunity acquired from a presumably slight exposure to infection. To provide a criterion, some infected ewes were immunosuppressed with corticosteroid, dexamethasone. Untreated ewes were extremely resistant to challenge infection with either 15,000 or 150,000 H. contortus or 15,000 T. colubriformis. Surprisingly, when mixed infection was given, egg counts for H. contortus were significantly elevated compared with infection by that species alone. Antibody to antigens from infective larval and adult H. contortus was measured in serum by enzyme-linked-immunosorbent assay (ELISA) during the course of infection. Serum titres against larval antigens were significantly depressed when infections with either H. contortus or T. colubriformis were permitted by immunosuppression with dexamethasone, whereas those against adult antigen were depressed when infection with T. colubriformis was permitted.     

Ergovaline does not alter the severity of ryegrass staggers induced by lolitrem B

AIM: To investigate a possible interaction between lolitrem B and ergovaline by comparing the incidence and severity of ryegrass staggers in sheep grazing ryegrass (Lolium perenne) containing lolitrem B or ryegrass containing both lolitrem B and ergovaline.

METHODS: Ninety lambs, aged approximately 6 months, were grazed on plots of perennial ryegrass infected with either AR98 endophyte (containing lolitrem B), standard endophyte (containing lolitrem B and ergovaline) or no endophyte, for up to 42 days from 2 February 2010. Ten lambs were grazed on three replicate plots per cultivar. Herbage samples were collected for alkaloid analysis and lambs were scored for ryegrass staggers (scores from 0–5) weekly during the study. Any animal which was scored ≥4 was removed from the study.

RESULTS: Concentrations of lolitrem B did not differ between AR98 and standard endophyte-infected pastures during the study period (p=0.26), and ergovaline was present only in standard endophyte pastures. Ryegrass staggers was observed in sheep grazing both the AR98 and standard endophyte plots, with median scores increasing in the third week of the study. Prior to the end of the 42-day grazing period, 22 and 17 animals were removed from the standard endophyte and AR98 plots, respectively, because their staggers scores were ≥4. The cumulative probability of lambs having scores ≥4 did not differ between animals grazing the two pasture types (p=0.41).

CONCLUSIONS AND CLINICAL RELEVANCE: There was no evidence for ergovaline increasing the severity of ryegrass staggers induced by lolitrem B. In situations where the severity of ryegrass staggers appears to be greater than that predicted on the basis of concentrations of lolitrem B, the presence of other tremorgenic alkaloids should be investigated.     

Association between weight change during initial chemotherapy and clinical outcome in dogs with multicentric lymphoma

The majority of the known prognostic factors in dogs with lymphoma have been evaluated before treatment commences or at the time of diagnosis. Prognostic factors evaluated during the initial phase of treatment are less described but may provide important clinical information. In this retrospective study, 82 canine lymphoma patients were categorized according to the weight change between diagnosis and after 5 weeks of chemotherapy. Dogs that gained greater than 5% or lost greater than 5% of initial body weight were categorized as increased‐ or decreased‐weight groups, respectively. Those in which weight changed less than 5% were categorized as the maintained‐weight group. The median progression‐free survival (PFS) in the increased‐weight group, maintained‐weight group and decreased‐weight group was 226, 256 and 129 days, respectively. The decreased‐weight group had significantly shorter PFS than the increased and maintained groups (P = .023, P = .003, respectively). The median survival time (ST) in the increased‐weight group, maintained‐weight group and decreased‐weight group was 320, 339 and 222 days, respectively. There was no significant difference in ST among the three groups (P = .128). In Cox‐regression results, weight change group and initial body weight were significant risk factors associated to PFS (P = .007, P = .001, respectively) while only patient's initial body weight was a significant risk factor to ST (P = .013). In conclusion, evaluation of initial body weight and weight changes over time can provide valuable information regarding PFS and ST in dogs with multicentric lymphoma.     

Enterotoxigenicity and cytotoxicity of Bacillus thuringiensis strains and development of a process for Cry1Ac production

Bacillus thuringiensis is indistinguishable from Bacillus cereus except for the production of insecticidal crystal proteins (ICPs). B. thuringiensis strains may show enterotoxin profiles and toxin levels similar to those of B. cereus strains isolated from food-poisoning cases. It is important for the food industry and farmers to consider that with the application of B. thuringiensis strains to crops, their spores may be introduced into the human food chain. In this study, 59 B. thuringiensis strains were assayed for their hemolysin BL (HBL) using a BCET-RPLA kit and their cytotoxicity to Chinese hamster ovary (CHO) cells. The enterotoxin titer was as high as that of B. cereus diarrheal-type strain ATCC 49064. In an attempt to obtain a food safety strain for bioinsecticide use, in this study, a 3.5-kb cry1Ac DNA fragment was amplified with PCR from the total DNA of B. thuringiensis subsp. kurstaki CCRC 11502 and cloned into the Bacillus expression vector pHY300PLK. The alpha-amylase promoter, amyE, was then introduced into the promoter region and, afterward, the recombinant plasmid pHYe1Ac35 was introduced into a non-enterotoxigenic and non-cytotoxic B. thuringiensis subsp. kurstaki Tt14 strain. The transformant, without any detectable enterotoxigenicity or cytotoxicity, produced Cry1Ac toxin properly, and its insecticidal activity against Trichoplusia ni larvae was found to be satisfactory.     

云南省曲靖市1995－2005年兽药质量抽检情况分析

以曲靖市兽药监察所最近十年的兽药质量监督抽检报告为基础材料进行统计分析，反映兽药质量监督抽检工作情况及兽药质量状况。     

人员在岗培训在实施兽药GMP现场管理中的作用

论述了对兽药生产企业进行人员在岗培训的必要性,对实施在岗培训的基本程序和应注意的事项进行了总结,旨在为兽药企业进行GMP现场管理提供参考。     

以電化學分析法探討堆肥對土壤三價砷活性的影響

台灣西南沿?貐^土壤中砷含量有偏高情形,砷含量過高會經由各種途徑對人體造成毒害。以X-射線繞射儀與傅立葉轉換紅外線吸收光譜儀證明普魯士藍對三價砷的孯恍晕綑C制,再以普魯士藍修飾電極搭配流動注入系統來偵測土壤三價砷,並探討堆肥對三價砷在不同土壤中吸附與脫附的影響。試驗結果得知電化學分析技術可快速、簡便且準確地偵測土壤三價砷,且結果中也指出堆肥處理會增加秀水與後里土壤對三價砷的吸附。此外,三種土壤不論有無施用堆肥,脫附百分率的大小順序爲興大>秀水>後里,其中秀水土壤雖在施用堆肥後吸附力大小明顯增加,但脫附百分率下降的情形較不明顯,顯示黏土礦物種類與含量控制三價砷的脫附行爲。     

Multiple forms of esterases in mouse,rat, and rabbit liver,and their role in hydrolysis of organophosphorus and pyrethroid insecticides

Six to seven esterases from mouse, rat, and rabbit liver microsomes were resolved by chromatofocusing in the pH range 7–4. Each esterase peak showed a different substrate specificity pattern with the substrates evaluated. Malathion and paraoxon hydrolysis always corresponded with p-nitrophenyl acetate and methylthiobutyrate hydrolysis, whereas the pattern of fenvalerate hydrolysis was more complicated. Phosphorotriester hydrolase activity was isolated, and was found to be more specific toward paraoxon than toward the other insecticides. Time-course studies of paraoxon hydrolysis indicated that the hydrolysis of paraoxon by carboxylesterase was an inhibitory reaction. This reaction and phosphorotriester hydrolase activity can serve as a detoxication reaction toward organophosphate insecticides.     

南黄杂种牛与本地黄牛生长发育对比研究

针对甘南本地黄牛体格小、生产性能低的现状，用南德温牛细管冻精授配甘南本地黄牛，结果表明，南杂F1代个体具有早熟、生长快、耐粗饲、饲料转化率高、抗病力强、难产率低等一系列优良特性，很适合当地黄牛养殖区大面积推广。