应用凝血反应检测杀鼠灵抗药性褐家鼠的可行性研究

为探讨凝血反应在鼠类抗药性检测中的应用前景,以褐家鼠为对象,在摄食实验基础上筛选抗药性褐家鼠,并在区分剂量12 mg/kg作用下分析抗药性和敏感性褐家鼠的凝血能力的变化情况。结果显示,抗药性个体在区分剂量作用下,凝血酶活动度虽有所下降,下降幅度可达正常水平的17%,但在2～3 d 内可恢复到正常凝血水平;而敏感性褐家鼠的凝血酶下降到很低,且在随后不能恢复。另外,对褐家鼠凝血酶活动度的分布及其存活的关系研究也提示,区分剂量可促使凝血酶活动度的种群分布从单峰型向双峰型分化,其中敏感个体的凝血酶活动度在0～3.16之间,而抗药性个体则在17～100 之间。并发现用药4 d 后的凝血酶活动度基本上可代表其未来的存活率,这提示了凝血反应与摄食实验结果的一致性。因此,以施药后4 d 凝血酶活动度PCA=17 或INR=5.0 作为阈值来区分抗药性和敏感性个体的凝血反应状况,进行家栖鼠抗药性测定是可行的。     

Endophytic Fungi in Four Winter Wheat Cultivars (Triticum aestivum L.) Differing in Resistance Against Stagonospora nodorum (Berk.) Cast. & Germ. =Septoria nodorum (Berk.) Berk.

Four winter wheat cultivars with different levels of resistance to Septoria nodorum were investigated at four locations during two vegetation periods. Forty plants per cultivar and site were collected at random at seven defined growth stages from crop emergence to harvest. Samples from roots, culms, leaves, glumes and kernels were examined for the occurrence of endophytic fungi after surface sterilization. 83% of the 26944 isolates sporulated and were assigned to 213 species. The most frequent were: Septoria nodorum (20.1%), Alternaria tenuissima (9.8%), Epicoccum purpurascens (9.1%), Idriella bolleyi (6.9%), Fusarium graminearum (5.3%), Fusarium culmorum (4.0%), Cladosporium oxysporum (3.7%), Didymella exitialis (3.1%), Fusarium nivale (2.8%) and Rhizoctonia solani (2.1%). Each species occurred preferentially in one or more plant organs. A factorial analysis of variance showed that plant organ, sampling site, vegetation, period and cultivar in decreasing order of importance influenced the quantitative and qualitative composition of the fungal populations. No relationship between endophytic fungi was found to be constantly antagonistic or mutualistic. Septoria nodorum was isolated mainly from culms. The number of S. nodorum isolates differed significantly between cultivars in culms and glumes but not in flag leaves. The results are discussed in relation to resistance breeding and the effect endophytic fungi, might have on yield.     

Germination of sclerotia of Sclerotium cepivorum Berk. under aseptic conditions

The response of sclerotia of Sclerotium cepivorum to a number of plant extracts and nutrient solutions was tested, aseptically, on agars, silica gels, filter paper discs, and on columns of soil. There was no specific response of sclerotia to extracts of Allium species in any of these experiments, whereas in unsterile soil consistently high levels of germination were obtained only with Allium extracts. It was shown that sclerotia are subject to the mycostatic influence of unsterile soil. With S. cepivorum soil mycostasis appears to be specifically reversed by Allium species or by water extracts made from them.     

Befall-Schaden-Relationen für das Wirt-Parasit-Paar Weizen-Septoria nodorum Berk.

Infestation-damage relationship for the host-parasite system wheat-Septoria nodorum Berk. It was the aim of these investigations to elucidate the relationship between infestation by Septoria nodorum Berk. and the damage caused thereby to the winter wheat varieties grown in the GDR. In 1983 and 1984 the varieties Alcedo and Taras were tested, and for the identification of typical varietal reactions, another 4 cultivars (Arkos, Compal, Mironovskaya 808 und Ilyitshovka) were included, in 1984. Artificial inoculation was carried out when the ears were emerging, using spore suspensions of varying density to achieve various degrees of infestation. For each variety, ear and flag leaf infestations were recorded on 800 culms and these were thengrouped into the categories I, II and III according to the number of points they had received (9 = without any infestation, 7 and 5 = number of points decreasing as infestation increased). Altogether 5–6 assessments were made, with the points given at the growth stage “beginning of the milky ripeness” being used as the basis for the calculation of the infestation-damage relationship. The most important criterion for each group was the mean single ear weight, the 1000-grain weight and the number of grains per ear, were also taken into consideration. Comparing ear infestation with yield it can be stated that the variety Compal and the early ripening Soviet varieties Mironovskaya 808 and Ilyitshovka showed relatively low losses. The variety Taras ranked in the middle. Alcedo and Arkos suffered the highest yield losses. Depending on the variety, an infestation level rated with 7 points at the beginning of milky ripeness implied yield losses of 5–13 %, whereas a 5 rating point would represent losses of 13–23 %. The results obtained make it clear that the wheat cultivars tested were not damaged by S. nodorum to the same degree, indicating differing varietal susceptibility, which does not allow a generalization with respect to the infestation-damage relationship for the host-parasite pair wheat-S. nodorum.     

The lipid content of epididymal spermatozoa of Rattus norvegicus.

1. Seven major lipids of rat spermatozoa from the caput, corpus and cauda epididymidis were separated and quantitated by TLC. 2. Spermatozoa from the caput epididymidis had a significantly greater (P less than 0.05) content of phospholipid, cholesterol, cholesterol ester and free fatty acid than those from the cauda epididymidis. 3. Spermatozoa from the corpus epididymidis had a significantly greater (P less than 0.05) content of monoglyceride than those from the caput epididymidis and a greater content of phospholipid, cholesterol, free fatty acids and monoglyceride than those from the cauda epididymidis.     

Ectoparasites of rodents of the urban region of Belo Horizonte, MG. II. Variations of the infestation indices in Rattus norvegicus norvegicus

The indices of infestation by the mites Echinolaelaps echidninus and Laelaps nuttalli, the louse Popyplax spinulosa and the flea Xenopsylla cheopis, obtained monthly, from June 1980 to September 1982, on Rattus norvegicus norvegicus in the city of Belo Horizonte, Minas Gerais state, Brazil were related to seasonal period, sex of the host and area of capture. Mites and insects showed different behaviour in relation to these factors. Only the fleas and lice exhibit significant association between the rodents' infestation and the seasonal period, or between the infestation and the rodents' sex or else a variation of the distribution by the three main areas of capture. The fleas showed the highest indices of infestation in the warm-rainy season (October to March) while the infestation by the lice was more prevalent in the dry-cool season. The climatic factors most related with the hosts' infestation were, in decreasing order, rainfall, temperature and relative humidity. Fleas and lice preferentially infested male rodents, being infestation by X. cheopis highly significant.     

Comparison of the half-lives and regeneration rates of blood clotting factors II,VII, and X in anticoagulant-resistant and susceptible Norway rats (Rattus norvegicus Berk.)

The half-lives and regeneration rates of clotting factors II, VII, and X in the plasma of anticoagulant-resistant and susceptible rats were determined. There is little or no difference in the half-lives of factors II and X in anticoagulant-resistant rats compared to susceptible rats, but the half-life of factor VII is longer in anticoagulant-resistant rats. In anticoagulant-resistant rats critical clotting factors appear to be carboxylated in preference to factor II, whereas the opposite occurs in susceptible rats; this may contribute to an animal’s resistance status.     

Beobachtungen anCordyceps sinensis (Berk.) Sacc. und verwandten Pilzen

Ohne Zusammenfassung     

Ectoparasites in rodents of the urban region of Belo Horizonte, MG. III. Fleas, Anoplura and Acari indices in Rattus norvegicus norvegicus

The total and specific indices of fleas, lice and mites were determined for ectoparasites on Rattus norvegicus norvegicus capture in urban areas of Belo Horizonte, Minas state, Brazil, from June 1980 to September 1982. In view of the limiting or critical values attributed to flea indices above all the "cheopis" index, proposed by several authors as a complementary measure for bubonic plague surveillance, the community of Belo Horizonte would have been exposed to this infection. The annual total indices ranged from 0.3 to 2.4 and the prevalent flea was Xenopsylla cheopis (99.2%), with the highest indices coinciding with the late dry-cool season. On two occasions, in this period, the community would have remained highly exposed to infection, since the index-limits were superseded: 8.8 (October 1980) and 6.2 (September 1982). It is suggested that preventive measures, such as protection against rat insecticide treatment may be efficiently applied in the late dry-cool season, or previous to the rainy season, before the elimination of rats. Reports on indices of lice and mites are important as they may establish index-limits for certain infections exclusive to rodents.     

Hemagglutinating activity of the fungusLentinus edodes (Berk.) sing [Lentinus edodes (Berk.) Pegler]

The hemagglutinating (HA) activity of the submerged mycelium and the culture liquid (CL) of four strains ofLentinus edodes was studied. The HA activity of the CLs proved to be much higher than that of mycelia. The carbohydrate specificity of fungal agglutinating factors was determined. HA activity was investigated as a function of the inoculum size, cultivation temperature, and culture age. The agglutinating activity of different morphogenetic structures ofL. edodes F-249, including mycelium, brown mycelial mat (MM), primordia, and fruiting bodies, was studied. MM was found to possess the maximum HA activity, which can be explained by the possible involvement of agglutinins in the formation of MM, which is composed of glued hyphae.