Interspecific agonistic behaviour in small mammals in a Mexican high-elevational grassland

Field trials were conducted throughout an annual cycle to study the role of agonistic behaviour in explaining the relative abundance of the volcano mouse ( Neotomodon alstoni ) in a small mammal community in high-altitude grasslands of central Mexico. Intrasexual contests between N. alstoni and three other sympatric rodents ( Peromyscus melanotis, Microtus mexicanus, and Reithrodontomys megalotis ) were performed. Male and female P. melanotis (100 and 67% of contests, respectively) and M. mexicanus (82 and 100%) were aggressively dominant over N. alstoni , whereas R. megalotis (80 and 100%) were not aggressive. Agonistic behaviour in this species did not explain its greater abundance in the community.     

Diazepam metabolism by multiple forms of cytochrome P-450 in rat liver microsomes

The synthesis of pharmacologically active diazepam metabolites (oxazepam, 4-hydroxydiazepam, N-demethyldiazepam) in liver microsomes of intact and phenobarbital-, 3-methylcholanthrene- and dexamethasone-induced male and female Wistar rats as well as in a reconstituted system with isolated forms of cytochrome P-450 (P-450a, P-450b, P-450c, P-450d and P-450k according to the Ryan nomenclature) was studied. Marked sex-dependent differences in the rates of diazepam metabolism in liver microsomes of intact and induced animals were revealed. The changes in the spectrum of diazepam metabolites in liver microsomes of induced rats (as compared to control animals) were revealed. In a reconstituted system only phenobarbital-induced cytochromes P-450b and P-450k were found to be active participants of diazepam N-demethylation; none of the isoenzymes tested were shown to be involved in diazepam hydroxylation.     

Comparative study of different variants of Actinomyces roseoflavus producing the polyene antibiotic roseofungin

The respiration chain in the membranes of whole Actinomyces roseoflavus (var. roseofungini) cells from the parent and secondary cultures is sensitive to KCN, non-sensitive to Triton X-100 treatment removing the antibiotic roseofungin from the cells, and has a very high for the bacteria respiration control. When the cells are in contact with atomic tritium at the temperature of liquid nitrogen, roseofungin is tritiated and binds to A. roseoflavus isolated membranes and whole cells, mostly to those of the parent culture as compared to the secondary culture. A fraction of membranes which lost NADH dehydrogenase in the course++ of purification was isolated from the cells disintegrated in the frozen state.     

Monoclonal Antibodies against Apple 1-Aminocyclopropane-l-Carboxylate Synthase

1-Aminocyclopropane-l-carboxylate (ACC) synthase from applefruits was purified over 5,000-fold by conventional column chromatography.By immunizing mice with this partially purified enzyme preparation,8 hybridoma lines producing monoclonal antibodies against appleACC synthase were isolated. While all 8 clones immunoprecipitatednative ACC synthase, only two clones recognized the putative(48 kDa) ACC synthase on Western blots. When a partially purifiedACC synthase preparation was incubated with S-adenosyl-L-[carboxyl-¹⁴C]methionine(AdoMet), only one radioactive protein of 48 kDa was detectedon sodium dodecyl sulfate-poly-acrylamide gel electrophoresis.This radioactive protein was specifically immunoprecipitatedby the monoclonal antibodies, indicating that apple ACC synthaseis specifically radiolabeled by its substrate AdoMet, as istomato ACC synthase. Thus, the monoclonal antibodies recognizedboth native and AdoMet-inactivated forms of ACC synthase. Whilethese antibodies failed to im-munoprecipitate ACC synthase isolatedfrom ripe tomato fruits, ripe avocado fruits or auxin-treatedmungbean hypocotyls, they were effective in immunoprecipitatingthe enzyme isolated from ripe pear fruits. (Received August 11, 1990; Accepted October 17, 1990)     

Palmar flexion creases in schizophrenia

Palmar flexion creases have been studied in schizophrenics with a family history of schizophrenia or other psychiatric disorders and without such a background, and compared to a control population. Palmar flexion creases have been analyzed according to the method suggested byBali & Chaube (1971). When compared to controls, differences in the DRBC and TRBC frequencies are significant in the subgroup with no family history, supporting the existence of biological heterogeneity in schizophrenia, and of congenital factors when there is no known genetic background.     

人黑色素瘤细胞分泌的组织纤溶酶原激活剂(t-PA)的纯化

 本文报道了培养的人黑色素瘤细胞分泌的组织纤溶酶原激活剂(t-PA)的纯化方法。Bowes株人黑色素瘤细胞的分泌产物,经CM-Sephadex C--50层析,赖氨酸-Sepharose 4B,苯甲眯-sepharose 4B亲和层析后,即可得到纯化470倍的蛋白纯品。样品经聚丙烯酰胺凝胶电泳鉴定为均一单带,测得其分子量约为72kD。纯化的t-PA与尿激酶相比较,发现前者有更高亲和纤维蛋白的能力。     

Carrageenophyte identification by second-derivative Fourier transform infrared spectroscopy

The second-derivative mode of the Fourier transform I.R. spectra of dried algal material has been applied to distinguish the carrageenans-producingStenogramme interrupta from the isomorphous speciesRhodymenia howeana. Spectra of the tetrasporophyteS. interrupta showed bands assigned to a -carrageenan type polysaccharide, while the gametophytic and cystocarpic plants showed the characteristic absorptions of -and -carrageenans. Results were confirmed by hot water extraction of samples of the three nuclear phases ofS. interrupta and characterization of the extracts by chemical analysis.Author for correspondence     

Species richness and endemism of birds in Bioko

The status of 50 taxonomically unique bird taxa found in Bioko is described. A complete updated species list for birds in Bioko is also given. Notes on habitat occupied and altitudinal distribution of each species as well as information on their general abundance is also included. Species distributions may have been affected by habitat modifications brought about by humans but most taxonomically unique forms are found in the montane areas. Comparisons are made with the neighbouring Mount Cameroon area.