Properties of a small basic Peptide from pumpkin seeds

A small basic peptide with an unusual amino acid composition has been isolated from the seeds of pumpkin, Cucurbita maxima. Amino acid analysis and sequence data show the protein to be about 36 residues in length, with an approximate composition Lys₁, Arg₁₄, Asp₃, (Glu + Gln)₁₅, Gly₁, Pro₁, Trp₁. On the basis of composition, the molecular weight is approximately 5000 daltons and the nitrogen content by weight is 20.4%. Twelve amino acids are entirely lacking. The peptide is slightly toxic to mouse B-16 melanoma cells, but its in vivo function is unknown. It does not appear to be derived from cucurbitin, the pumpkin storage globulin; however, it could be a storage peptide involved in nitrogen mobilization during the early stages of germination.     

Transforming activities of sodium fluoride in cultured Syrian hamster embryo and BALB/3T3 cells

The transforming activity of sodium fluoride was studied in the SHE and the BALBl3T3 cell culture systems. Initiating and promoting activities were then investigated by means of the orthogonal methodology. Sodium fluoride was found to induce morphological transformation of SHE cells seeded on a feeder layer of X-irradiated cells at high concentrations (75–125 g/ ml). When the cells were seeded in the absence of a feeder-layer, the transformation frequencies increased in a dose-dependent manner with the concentrations of sodium fluoride ranging from 0 to the highly toxic concentration of 200 g/ml. In the BALBl3T3 cell system, sodium fluoride was negative in the standard Kakunaga procedure, while through the experiment designed by table L₈ (2⁷) of the orthogonal method, an initiating-like effect and a weak promoting activity were detected within the concentrations ranging from a 25 g/ ml to a 50 g/ ml concentration which is highly toxic for BALBl3T3 cells. From these results, it is suggested that, besides a genetic mode of action, sodium fluoride could possibly act through a non-genotoxic mechanism.Abbreviations CE cloning efficiency - NaF sodium fluoride - SHE Syrian hamster embryo - TF transformation frequency     

海南岛尖峰岭热带林土壤渗透水的初步研究

 本文应用开口托盘式集水器收集不同土层的渗透水,研究尖峰岭热带山地雨林,半落叶季雨林及其游耕地的土壤渗透水状况,分析了不同植被—土壤类型与利用状况的渗透特点、降水与渗透水的关系、渗透水量与水质的动态变化,初步揭示了尖峰岭热带林对水分的输导—涵贮性能,及热带林生态系统中物质迁移的特点,并据此分析了游耕农业的生态恶果。     

Shoot-bud regeneration in subcultured callus of engelmann spruce

Summary Callus cultures ofPicea engelmannii (Parry, Engelmann spruce) were initiated and established from mature embryos cultured on von Arnold and Eriksson’s medium (AE) supplemented with N⁶-benzyladenine (10μM) and naphthalene acetic acid (10 μM). Cultures were maintained by subculture at 3-to-4-wk intervals. After three subcultures, callus was transferred to AE medium with only N⁶-benzyladenine (25 μM). Adventitious buds appeared on the surface of the callus after 2-to 4-wk and grew to adventitious shoots on AE medium without growth hormones or on AE medium with kinetin (0.1 μM). Shoot-forming capacity was maintained through 7 further subcultures. This study was supported by the Natural Sciences and Engineering Research Council of Canada grant G1438 to T. A. Thorpe and D. I. Dunstan.     

Morphology and Taxonomy of <Emphasis Type="Italic">Apristurus longicephahis</Emphasis> (Lamniformes,Seyliorhinidae)

Data on the individual variation and changes with growth in proportions and morphology are presented for the poorly known Apristurus longicephalus, and compared with those of other species. A. longicephalus is concluded to be a distinct species without synonyms, characterized by its long snout, widely separate nostrils, long caudal fin, short abdomen, very sparse teeth, and low number of monospondylous vertebrae. It is a species of small size, maturing at about 42 cm in total length.     

Scale Growth and Squamation Chronology for the Laboratory-Reared Hermaphroditic Fish <Emphasis Type="Italic">Rivulus marmoratus</Emphasis> (Cyprinodontidae)

Scale morphology, growth and the squarnation chronology are described for the hermaphroditic fish Rivulus marmoratus reared in the laboratory. The scales are round or oval shaped cycloid type, and their sizes are about 0.3–1.0 mm in diameter. The number of ridges increases more rapidly relative to the body growth of the fish in early stages, but this increase is proportionate to growth subsequently. Three loci of scale development have been identified. The scales first appeared on the center of the parietal region at 8 days after hatching. The second locus of scale formation was on the lateral line of the posterior end of the caudal peduncle. A third locus was later observed on the lower right corner of the operculum: The final squamation was completed at 6 weeks after hatching.     

Protein synthesis in the hippocampus associated with memory facilitation by corticotropin-releasing factor in rats.

The present study used pharmacological, biochemical, and behavioral methods to examine the role of protein synthesis in the hippocampus in memory processes of a passive avoidance learning in rats. Results indicated that corticotropin-releasing factor (CRF) significantly improved memory retention in rats. Both cycloheximide (CHX) and actinomycin-D (ACT-D) impaired memory at high doses. At doses of CHX and ACT-D that did not affect memory alone, they both antagonized the memory-enhancing effect of CRF. Biochemically, there were specific increases in the optical density of three protein bands in the cytosolic fraction of hippocampal cells in rats showing good memory. There were also marked increases in the optical density of two protein bands in the nucleus fraction of the same animals. Similar results were observed in animals injected with CRF. However, no significant protein alteration was observed in animals receiving stress. These results together suggest that there are new protein syntheses in the hippocampus that are specifically associated with passive avoidance learning in rats.     

白腹锦鸡机体营养成分的分析与探讨

本文报道笼养和野生白腹锦鸡机体营养成分及其差异。分析表明,笼养的比野生种营养成分含量高的有:腿肌蛋白质高11％,胸肌、腿肌、全血的氨基酸分别高2.64％,1.39％和4.68％,胸肌、腿肌和肝脏的碳水化合物分别高0.076％、0.092％和3.962％,胸肌和腿肌的维生素A分别高188.63和84.09 I.U.,胸肌和腿肌的维生素D分别高47.2和12.8 I.U.。但是胸肌蛋白质含量笼养的比野生的低26％。     

鳗鲡幼鱼耳石日轮的研究

本文报道采自辽东半岛沿岸鳗鲡(Anguilla japonica)的白仔鳗和经人工培育的当年幼鳗耳石日轮生长的观察结果。白仔鳗和幼鳗耳石平均直径均与体全长成直线相关。12尾白仔鳗耳石的平均日轮数146.3,据此推测其产卵期为11—12月。观察证实从咸淡水转人到淡水生活的幼鳗耳石的环纹有过渡带存在。     

红腹锦鸡和白腹锦鸡卵壳的超微结构

本文报道了锦鸡属——白腹锦鸡和红腹锦鸡卵壳的气孔、外壳膜、锥体层、木栅层的超微结构。并对两者的卵壳进行了比较。