Veterinary aspects of alveolar echinococcosis--a zoonosis of public health significance

Human alveolar echinococcosis (AE), caused by the metacestode stage of Echinococcus multilocularis, is a serious zoonosis which caused up to 100% lethality in untreated patients before the 1970s, when modern methods of treatment were not yet established. AE occurs in large areas of the northern hemisphere mostly with low country-wide prevalences, but high prevalences of up to 4% have been reported from small population groups in highly endemic foci, e.g. from China. AE includes many veterinary aspects which are the topic of this review. Recent studies have shown that E. multilocularis has a wider geographic range than previously anticipated. There is evidence for growing populations of red foxes (Vulpes vulpes) in some areas, for increasing invasion of cities by foxes and also for establishment of the parasite cycle in urban areas. These and other factors may lead to an increased infection risk for humans. Significant progress has been made in the development of sensitive and specific new techniques for the intra vitam and post mortem diagnosis of intestinal E. multilocularis infection in definitive hosts, notably the detection of coproantigen by enzyme-linked immunosorbent assay and of copro-DNA by PCR. Both tests can also be used for the identification of E. multilocularis in faecal samples collected in the environment. Recommendations are given for chemotherapy and chemoprophylaxis of the intestinal infection in definitive hosts. In recent years, infections with the metacestode stage of E. multilocularis have not only been diagnosed in humans in several regions, including at least eight countries in central Europe, but also in animal species which do not play a role in the transmission cycle (wild and domestic pigs, dogs etc.). From 1987 to 2000 our group in Zurich has diagnosed 10 cases of AE in dogs and 15 in captive monkeys. In 2 dogs, concurrent infections of the intestine and of the liver with adult and larval stages of E. multilocularis, respectively, were observed for the first time. Clinical data are presented, and methods of diagnosis and treatment (surgery, chemotherapy) are described. Furthermore, small liver lesions caused by E. multilocularis were diagnosed in 10% of 90 slaughter pigs, and 2.9% of 522 breeding sows had specific serum antibodies against parasite antigens. In view of the unpredictable epidemiological situation, all possible measures for preventing E. multilocularis infections in humans and in domestic animals should be initiated by the veterinary and health authorities.     

Copper status of ewes fed increasing amounts of copper from copper sulfate or copper proteinate

The Cu status of mature, crossbred ewes fed two sources (CuSO4 vs. Cu proteinate) and three levels (10, 20, or 30 mg/kg) of dietary Cu was determined in a 73-d feeding trial. Ewes (n = 30) were fed a basal diet containing rice meal feed, cottonseed hulls, cottonseed meal, meat and bone meal, cracked corn, and vitamin-mineral supplements at 2.5% of BW to meet NRC requirements for protein, energy, macrominerals, and microminerals, excluding Cu. The basal diet contained 5 mg/kg Cu, 113 mg/kg Fe, .1 mg/kg Mo, and .17% S. Copper sulfate or Cu proteinate was added to the basal diet to supply 10, 20, or 30 mg/kg of dietary copper in a 2x3 factorial arrangement of treatments. Ewes were housed in 3.7- x 9.1-m pens in an open-sided barn. Blood samples were collected on d 28 and 73. Ewes were slaughtered on d 74, and liver and other tissues were collected to determine Cu concentrations. An interaction (P = .08) occurred between source and level for liver Cu. The interaction existed due to an increase in liver Cu concentrations when ewes were fed increasing dietary Cu from CuSO4 but not when fed Cu proteinate diets. There was no source x level interaction (P>.10) for the blood constituents measured. On d 73, plasma ceruloplasmin activity was greater (P<.05) in ewes fed Cu proteinate than in those fed CuSO4 (33.1 vs. 26.8 microM x min(-1) x L(-1)). Increasing the concentration of dietary Cu did not affect (P>.10) plasma ceruloplasmin. Packed cell volume (PCV), red blood cell count (RBC), white blood cell count, whole blood hemoglobin (wHb), plasma hemoglobin, and plasma Cu were similar between sources of Cu. Ewes fed 20 mg/kg Cu had lower (P<.05) PCV, RBC, and wHb than those fed 10 or 30 mg/kg Cu diets. Feeding up to 30 mg/kg Cu from these sources did not cause an observable Cu toxicity during the 73-d period.     

Economic analysis of an outbreak of avian influenza, 1997-1998

OBJECTIVE: To determine economic losses associated with an outbreak of avian influenza in flocks in Pennsylvania during 1997 and 1998. SAMPLE POPULATION: 5 premises containing avian influenza-infected layer, pullet, and turkey flocks. PROCEDURE: Losses incurred before depopulation, those incurred at the time of depopulation, and those that were attributable to depopulation (unrealized loss of income) were evaluated. Results were extrapolated to provide values for all infected flocks. RESULTS: Extrapolating the costs determined on the basis of age and number of birds from the 5 sample flocks to all other flocks infected with nonpathogenic avian influenza H7N2 yielded an estimated total cost to the Pennsylvania poultry industry of $3.5 million. CLINICAL IMPLICATIONS: The H7N2 virus is not highly pathogenic. If the pathogenicity of the virus does not change, then the poultry industry and state and federal governments will not have severe economic losses for the 1997-1998 outbreak similar to those for the 1983-1984 avian influenza outbreak in Pennsylvania. To decrease the potential for financial losses that could result from future outbreaks of avian influenza, it is essential that the commercial industry and livebird market system be separated via increased use of biosecurity measures.     

Isolation,Culture and Identification of Testis Sertoli Cells in Mongolian Horses in vitro

To study a simple and rapid separation of testis Sertoli cells in Mongolian horses and ensure their activity,the testis tissue of two-year-old Mongolian horses was mechanically isolated under a low temperature environment in this experiment,and 1-3 g of testis tissue was chopped,the free red blood cells and interstitial cells were removed by gravity precipitation method.0.1% collagenase Ⅳ and 0.25% trypsin-EDTA were used for tissue digestion, and cells were cultured in medium containing 10% fetal bovine serum.After inoculation,the purified Sertoli cells were isolated and purified by differential sticking method,and the impurity cells were removed by Tris-HCl infiltration method,and were identified by alkaline phosphatase (AKP) staining,HE staining and Real-time quantitative PCR.The results showed that most of the cells began to adhere to the wall after culture 24 h,and the shape of the cells was oval.After culture 48 h,the cytoplasm increased and the refraction became stronger.After culture 3-4 d,the cytoplasm of the cells expanded into tight junction.At this time,the cells were triangular with obvious nucleoli.After culture 6-7 d,the cells entered the stable phase.Real-time quantitative PCR results showed that the expression of GATA4 and GDNF genes were extremely significantly expressed in cultured cells (P<0.01).AKP staining supported the negative expression in Sertoli cells,indicating that the isolated cultured cells were indeed Sertoli cells.In this experiment,tissue was treated by mechanical separation and two-step enzyme digestion,and testicular support cells were obtained quickly and efficiently,the method of culturing Sertoli cells in Mongolian horses testis in vitro was successfully constructed.     

苜蓿蓟马抗性与生理活性相关性研究

1材料与方法1．1试材与试验地概况供试材料为现蕾期的草原2号紫花苜蓿、敖汉苜蓿、阿尔冈金苜蓿及自选抗蓟马新品系紫花苜蓿。试验地设置在呼和浩特内蒙古农业大学科技园区牧草试验站内种植3年的人工草地。该地位于东经111°48’,北纬40°48’,海拔1063m,属于典型大陆性气候,日气温最高和最低分别为36．9℃和-33℃,年均气温5．4℃,≥10℃年积温2915℃,年平均降水量350-400mm,主要集中在7-9月,无霜期135d：