玉米F_2群体中偏分离RFLP标记在染色体上的分布及原因分析

研究了利用玉米85个 DNA 限制性片段长度多态性(RFLP)标记在玉米自交系7922与5003杂交 F2群体中的分离。结果表明,8.33%的标记显著或极显著地偏离了预期的孟德尔比例而表现偏分离,发现了2个偏分离的染色体热点,即第1染色体上的 umc128-umc107和第3染色体上的 asg24-asg48,其偏分离形成的主要原因是存在配子体选择。     

Serum and Tissue Steroid Hormone Levels in Canine Mammary Tumours: Clinical and Prognostic Implications

Hormonal dependency of canine mammary tumours (CMT) has been studied over the last few decades. However, studies assessing the prognostic and predictive potential of serum and/or tissue steroid hormone levels are still scarce in CMT. To the best of our knowledge, this is the first report relating serum and tissue levels of steroid hormones and prognosis in dogs. Serum and tumour tissue from 45 female dogs with spontaneous CMT were included in the study. Moreover, serum and normal mammary tissue from 13 healthy female dogs were also included as controls. Steroid hormones were determined by competitive enzyme immunoassay. Overall, levels of steroid hormones in serum and tissue homogenates were significantly different between malignant and benign mammary tumours (p < 0.01), except for progesterone (P4) serum levels that revealed no statistical differences between groups. In malignant tumours, oestrone sulphate (SO4E1), dehydroepiandrosterone (DHEA), androstenedione (A4), testosterone (T) and P4 elevated tissue concentrations were significantly associated with tumour relapse and/or distant metastasis during follow‐up. A significant association was found between elevated tissue SO4E1 (p = 0.003), 17β‐oestradiol (E2) (p = 0.036), DHEA (p = 0.022), A4 (p = 0.001) and P4 (p = 0.013) concentrations and shorter disease‐free survival and overall survival in female dogs with malignant mammary tumours. The high levels of tissue steroids found in cases of poor prognosis open the possibility of additional new therapeutic approaches. Future clinical trials will be needed to clarify the usefulness of targeting steroid hormones in the treatment of this neoplastic disease.     

Solid‐Surface Vitrification and In‐Straw Dilution After Warming of In Vitro‐Produced Bovine Embryos

Three experiments were designed to test a solid‐surface vitrification system for bovine in vitro‐produced embryos and to develop a simple method of in‐straw dilution after warming, which can be potentially used for direct transfer in the field. Experiment 1 evaluated embryo survival rates (i.e. re‐expansion and hatching) after vitrification and warming in three different solutions: VS1 (20% ethylene glycol (EG) + 20% propanediol (PROH) + 0.25 m trehalose (Tr)), VS2 (20% EG + 1M Tr) or VS3 (30% EG + 0.75 m Tr). Re‐expansion and hatching rates were higher (p < 0.05) for embryos vitrified in VS3 (72.2 ± 1.9 and 58.2 ± 0.8) than VS1 (64.4 ± 0.9 and 37.2 ± 2.5) or VS2 (68.5 ± 1.5 and 49.6 ± 1.0; p < 0.05). Experiment 2 was designed to compare two methods of vitrification: glass micropipettes or solid surface, using the VS1 or VS3 solutions. No significant differences were detected between the two methods; but re‐expansion and hatching rates were higher (p < 0.05) with VS3 (73.5 ± 3.1 and 47.1 ± 2.1) than VS1 (63.3 ± 3.3 and 39.7 ± 2.8). In experiment 3, embryos were vitrified by solid surface in VS1 or VS3 solutions and cryoprotectants were diluted in‐straw after warming in a TCM 199, 0.25 m sucrose solution or holding media. Survival rates of embryos vitrified in VS3 did not differ between those exposed to 0.25 m sucrose (74.7 ± 1.3 and 57.2 ± 2.2) or holding (77.3 ± 1.4 and 58.0 ± 2.5) medium after warming; however, survival rates of embryos vitrified in VS1 were higher (p < 0.05) in those exposed to 0.25 m sucrose (67.7 ± 2.3 and 47.0 ± 1.7) than holding medium (54.5 ± 1.0 and 27.7 ± 3.1). In conclusion, solid‐surface vitrification using simplified EG‐based solutions and in‐straw dilution with holding media may be a practical alternative for cryopreservation and direct transfer of in vitro‐produced bovine embryos.     

治疗奶牛乳腺炎的新药盐酸吡利霉素研究进展

综述了治疗奶牛乳腺炎的新药——盐酸吡利霉素最新研究进展.对其基本药学性质、药动、药效、毒性和残留等多方面进行了详细阐述.     

磷酸泰乐菌素颗粒剂生物效价测定方法的建立及验证

建立了磷酸泰乐菌素颗粒剂的生物效价测定方法，并对新建立的测定方法进行了验证，验证内容包括：方法对照试验、精密度试验、线性及线性范围试验、回收率试验。验证结果证明新方法能准确测定磷酸泰乐菌素颗粒剂的效价单位。     

Absorption,translocation and distribution of lindane and DDT in the corn plant

Summary Data are given on the translocation and distribution of lindane and DDT in corn plants, and on their accumulation in corn kernels.The studies were conducted between 1966 and 1968, using emulsifiable products containing lindane and DDT formulated according to the same formulation. The insecticides were introduced in the plant by absorption from the soil and by injection.A part of the internodes of the 5 plants, representing a variant, were analysed. From the data obtained it results that insecticide absorption in the plants varies in terms of the date of application, and the rate of plant development.Following plant injections, DDT accumulated in larger amounts than lindane and, conversely, by absorption from the soil lindane was absorbed in larger quantities.It was found that both lindane and DDT are able to translocate and accumulate in corn plants and kernels. This translocation is higher for lindane and less so for DDT. In the case of lindane, an accumulation at the level of the physiologically active plant centers was established.Compound accumulation in a larger or smaller proportion is also a function of the water regime,, and their localization in various zones of the plant probably is governed by some physiological factors.

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Zusammenfassung Daten über Translokation und Verteilung von Lindan und DDT in der Maispflanze sowie über Anreicherung in den Maiskörnern werden mitgeteilt.Die Forschungsarbeiten wurden in den Jahren 1966–1968 durchgeführt. Als Versuchspräparate dienten emulgiertes Lindan und nach der gleichen Formulierung hergestellte DDT-Emulsion.Die Insektizide wurden der Pflanze auf zwei verschiedenen Wegen zugeführt, und zwar durch Bodenabsorption und durch Injektion.Die Internodien der 5 Pflanzen, die eine Variante bildeten, wurdern auf Rückstände analysiert.Auf Grund der erzielten Resultate wird festgestellt, daß die Insektizidaufnahme durch die Pflanze von ihrem Entwicklungsstadium und von dem Behandlungstermin abhängig ist.Von den injizierten Insektiziden wurden in der Pflanze größere DDT-Mengen gespeichert, während durch Bodenabsorption größere Mengen Lindan von der Pflanze aufgenommen wurden.Es wird weiterhin festgestellt, daß sowohl Lindan als auch DDT in der Maispflanze bis in die Körner weitergeleitet und gespeichert werden kann. Bei Lindan ist die Translokation intensiver als bei DDT.Größere Lindananreicherungen wurden im Bereich der physiologisch aktiven Pflanzenzentren festgestellt.Größere oder geringere Anreicherungen von Insektiziden in der Pflanze hängen auch von ihrem Wasserhaushalt ab, während die Lokalisierung in den einzelnen Pflanzenzonen von bestimmten physiologischen Faktoren abhängig ist.

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Résumé On présente des données sur la translocation et la répartition du lindane et du DDT dans la plante de maïs, et sur leur accumulation dans les graines.Les recherches ont été effectuées de 1966 à 1968, en utilisant des produits émulsifiables contenant du lindane et du DDT, conditionnés selon la même formulation.Les insecticides ont été introduits dans la plante soit par absorbtion, soit par des injections.On a analysé partiellement les internodes des 5 plantes qui ont constitué une variante.Les données obtenues montrent que l'absorbtion des insecticides dans la plante varie en fonction du moment de l'application du traitement et en rapport avec le degré de développement de la plante.A la suite des injections, le DDT a été accumulé en plus grande quantité que le lindane et, au contraire, l'accumulation du lindane a été plus importante à la suite de l'absorbtion à partir du sol.On constate que le lindane et le DDT peuvent être transloqués et accumulés dans les plantes et les graines de maïs. Cette translocation est plus importante chez le lindane, et elle est moindre dans le cas du DDT. En ce qui concerne le lindane, on constate des accumulations au niveau des centres physiologiquement actifs de la plante.L'accumulation en une proportion plus ou moins grande est aussi conditionnée par le régime de l'eau, cependant que la localisation de ces substances dans diverses zones de la plante est déterminée par certains facteurs physiologiques.