Fetal rat brain hemisphere tissue in nonadherent stationary organ culture

Summary A simple organ culture system for brain tissue is described. Fragments of fetal rat brain hemisphere tissue are explanted to multiwell dishes base-coated with semisolid agar. In this system nonadherent organ culture can be performed for at least 50 days. Cell migration, biochemical and morphological differentiation and the formation of a layered architecture seem to mimic some of the phenomena occurring in the developing rat brain in vivo. The fragments may therefore be a useful organ culture model for nervous tissue.     

Persistence of added retinoids in organ culture media during induction of mucous metaplasia and glandular morphogenesis in hamster cheek pouches

Summary The retinoid concentration (determined colorimetrically) did not change significantly in retinyl acetatesupplemented (6 g/ml) Eagle's Minimal Essential Medium containing 10% fetal calf serum when stored at –20 or 4°C over 7 days. After the medium was incubated at 37°C for 48 h, 37–49% of the retinoid remained, whether or not tissue (neonatal Syrian hamster cheek pouch) was present, and irrespective of explant age. The normal retinoid level in the tissue was approximately 0.25 g per gram. Therefore, neonatal hamster cheek pouches, incubated in medium with the addition of 6 g of retinyl acetate per ml of medium and undergoing mucous metaplasia and some mucous gland morphogenesis, were continually being exposed to retinoid levels which, though gradually decreasing, remained well above their normal physiological level.     

器官移植与伦理道德问题探讨

文章阐述了国内外器官移植概况及其面临的伦理道德问题,提出自己的见解与建议。     

Studies on biological characteristics of ginkgo hairy root culture

The comparative studies on properties of growth and cultivated conditions of seven transformed ginkgo hairy root clones were reported. Different clones display various phenotypes characterized by growth rate. The results show that the suitable inoculum is benefical to the growth of ginkgo hairy root. NH₄ ⁺/NO₃ ⁻, pH, sucrose, and inositol have important effects on the growth of ginkgo hairy root. Foundation item: Supported by China National Center for Biotechnology Development Ministry of Science and Technology Biography: Li Gen-bao(1970-), male, Postgraduate.     

爬行动物的免疫

爬行动物的免疫分为非特异性和特异性两种,特异性免疫包括免疫器官、细胞免疫和体液免疫,因而本文将从免疫器官的类型和组织结构、移植物的排斥反应,抗体的合成和理化特性等几个方面系统综述爬行动物的特异性免疫,全面了解免疫机制对爬行动物的病害防治具有重要意义。     

肉鸡生长期内脏器官的生长分析

选艾维茵肉鸡商品雏２００只,按常规饲养管理,于初生和１,２,…,７周龄的周末,分性别各解剖８只,测量内脏器官重量、消化道重量及各部分长度,并进行与体重变化的回归分析．结果表明：内脏器官和消化道各部分的长度随体重同步变化,约在４周龄时内脏器官重超过整个生长期的平均数,且内脏器官重、消化道长度与鸡体重的幂回归的相关系数最高．