新疆绿蟾蜍的染色体组型初步研究

近年来,有关两栖类的染色体组型已有不少报道。无尾两栖类中蜍蟾属(Bufo)的染色体数目分为两类:2n=22和2n=20(Blain,1972)。我们对采自新疆4个地区的绿蟾蜍进行了染色体组型分析,发现其二倍体细胞染色体数均为44,是四倍体。现将我们的初步研究报道如下。     

Variations of susceptibility to alloxan induced diabetes in the rabbit

The variations of susceptibility to alloxan induced Diabetes in a total of seventeen rabbits was described. Our study was designed to explore dosage schedules which might improve rabbit responsiveness to and survival after alloxan treatment. A wide range of response to intravenously administered alloxan was observed. Permanent diabetes (blood glucose 350 mg/dl) was found in three rabbits after a single injection (60 mg/kg in one, 100 mg/kg in two). This effect has persisted for eight months. By contrast, two other rabbits injected with a single dose of alloxan (60 mg/kg) developed only transient hyperglycemia. Similarly, four other rabbits either did not respond or had an incomplete response after receiving a total dose of 120 mg/kg. These data suggest that there is extreme variability in individual rabbits susceptibility to the diabetogenic affects of alloxan.     

Scavenging effect of extracts of green tea and natural antioxidants on active oxygen radicals

With the use of the spin trapping methods, the scavenging effects of the extracts of green tea and other natural foods are studied. In stimulated polymorphonuclear leukocytes (PMN) system, water extract fraction 6 (F6) from green tea and green tea polyphenols (GTP) have the strongest scavenging effect on the active oxygen radicals, much stronger than vitamin C (Vc) and vitamin E (VE). Rosemary antioxidants (RA) and Curcumin (Cur) have weaker scavenging effects than Vc, but stronger than VE. In Fenton Reaction, Cur has the strongest scavenging effect (69%) on hydroxyl radicals. In irradiation, riboflavin system F6(74%) and GTP(72%) have very strong scavenging effects that are weaker than Vc, but much stronger than VE (23%). With the use of spin probe oxymetry, the oxygen consumption in respiratory burst of stimulated PMN were measured when the antioxidants existed in these systems. The results demonstrated that these antioxidants did not affect the respiratory burst of human polymorphonuclear leukocytes stimulated with PMA.     

Isolation and purification of protein kinase C from human leukemia ML-1 cells phosphorylation of human leukemia RNA polymerase II in vitro

Protein kinase C (PKC) was purified to near homogeneity from human leukemia ML-1 cells. The purified enzyme showed a single polypeptide band of 80 kDa on SDS-polyacrylamide gel after electrophoresis, and was totally dependent on Ca2+/phospholipid for activity. Diacylglycerol and the tumor-promoting on Ca2/phospholipid for activity. Diacylglycerol and the tumor-promoting phorbol esters stimulated the enzyme activity. Autophosphorylation of PKC purified from phenyl-Sepharose column showed both 80- and 37 kDa polypeptides. Further fractionation of PKC on a hydroxyapatite column revealed two peaks of enzyme activity, indicating that there may be two different forms of protein kinase C present in human leukemia cells. The purified PKC was used to phosphorylate RNA polymerase II of human leukemia cells in vitro and the autoradiogram showed that RNA polymerase II large subunits (240, 220 and 150 kDa) were phosphorylated in a time-dependent manner.     

X-chromosome polysomy in the male

Summary A review of 569 male patients with X-chromosome polysomies (544 Klinefelter and 25 patients with other types of X-chromosome polysomy) is presented here. These patients were detected among the 77000 persons karyotyped in the Leuven cytogenetic center between the years 1966 and 1987. In the group of 544 Klinefelter patients special attention was paid to (1) the age at diagnosis, (2) social and marital status of the postpubertal males, (3) physical and intellectual abilities of the prepubertal boys, (4) delineation of the concurrence of Klinefelter syndrome and fragile X syndrome, and (5) the frequency of malignancies. In 25 patients with other X-chromosome polysomies (2 n48 chromosomes) genotype/phenotype correlation is reviewed, especially for the patients with 48,XXYY and 49,XXXXY karyotypes. Finally, double aneuploidy and rare structural X-chromosome aberrations are briefly discussed.     

兰萼丙素的结构

从北京地区产兰萼香茶菜[Rabdosia japonica (Burm. f.)Hara var.glaucocalyx(Maxim.)Hara]叶中分得三个对映-贝壳杉烯二萜化合物,其中二个为已知物兰萼甲素(2)和乙素(3),另一个为新化合物,命名为兰萼丙素,经光谱和化学方法证明,其结构为对映-7β,14α,15α-三羟基-16-贝壳杉烯-3-酮(1)。     

用免疫荧光技术研究细胞周期中核基质的分布变化

本文利用含有抗核基质自发抗体的硬皮人血清,以小鼠艾氏腹水癌细胞为材料,用间接免疫荧光染色的方法,追踪了对应核基质抗原在细胞周期中分布的变化。结果显示,在末期和间期之间存在一个核基质抗原从细胞质向细胞核内转移的过程。由于这一过程是通过核膜进行的,从而提示核基质结构可能有解聚和再聚合的行为。用酶化学结合间接免疫荧光染色的方法,初步研究了抗原的化学性质。染色形态的比较研究显示所用血清中可能含有不同于以前发现的、抗新的核基质抗原的自发抗体。     

湖北安陆新的恐龙蛋类型的发现及其意义

本文记述的恐龙蛋化石标本,采自湖北省江汉盆地公安寨组下部.蛋化石保存完好.在普通光学显微镜和扫描电镜下观察,蛋壳的显微结构完整,清晰可见.根据钙质蛋壳基本结构单位的形态及排列特征,笔者建立了—新属,新种——Dendroolithus wangdianensis gen. et sp. nov.,代表恐龙蛋类一个新科——Dendroolithidae fam. nov.此外,残存的卵壳膜纤维化石的发现,将为进一步研究恐龙蛋卵壳膜的结构和氨基酸组成提供宝贵材料.     

不同季节银木叶精油化学成分的研究

用毛细管气相色谱-质谱-计算机联用技术、毛细管气相色谱双柱保留指数法和双柱标准品叠加法分析了不同季节银木叶精油化学成分。从分离出来的207—250个色谱峰中,初步鉴定出59个成分,被鉴定成分的总量占精油总组成的94.45—98.92%,其主要成分随采油季节不同而有所不同。