阿胶,新阿胶,黄明胶,马皮胶,杂皮胶的质量对比研究：Ⅰ.氨基酸分析

本文用835-50型氨基酸自动分析仪测定了阿胶、新阿胶、黄明胶、马皮胶和杂皮胶中游离氨基酸和总氨基酸的含量,并计算出游离氨基酸、总氨基酸按侧链基团分类和按医药用途分类的相对含量。结果表明,各种氨基酸含量一般以驴皮胶为较高,但与其他几种胶比较并无显著差异,似可以猪皮马皮、牛皮代替驴皮。这也说明,单从氨基酸的含量来鉴别胶的种类和质量似乎不可行。     

Growth-related changes in predation behavior in incipient colonies of the ponerine antEctatomma tuberculatum (Olivier)

Summary We traced the development in the laboratory of 18 young colonies of the arboricolous ponerine antEctatomma tuberculatum. Colony foundation is of the partially-claustral type. During the early stages, when the colony is entirely dependent on the queen's behavior, the growth of the colony in terms of number of workers produced over time was relatively predictable. Afterwards, divergence in colony growth in function of the time increases as fast as the number of workers influences the efficiency of colony provisioning.Comparative analysis indicated clear changes in the predation behavior of foundresses and workers as colonies developed. For any stage of colony growth, all individuals provisioned the nest with dead prey or sugar-rich substances in the same way. However, prey hunting involves two different strategies. Foundresses and nanitic workers (originating from colonies with 9–15 workers) foraged actively, catching prey as the result of random encounters. Post-nanitic foragers (originating from colonies with 20–30 workers) and those from nature colonies developed an ambush strategy. Workers in these colonies gained experience at catching and handling prey during a period when they acted as nest guards, and so tended to be more efficient hunters than poorly experienced foundresses or nanitic foragers. The change in strategy was also positively correlated with an increase in the size of workers as the colony matured. A stable maximum in workers size is apparently reached only after the appearance of efficiently hunting foragers, presumably in numbers sufficient to provide adequate quantity and quality of larval food. Such a correlation between worker size and colony growth, assumed general for all ants, has not been demonstrated for Ponerinae before this work.     

Manganese as a controlling factor in mixed cultures of Lactobacillus plantarum and enterobacteriaceae

Addition of manganese, at levels of 50 ppm, to a liquid growth medium simulating adverse silage conditions had no effect on the growth or on the fermentation pattern of Enterobacter cloacae and Proteus vulgaris. Yet, the manganese strongly enhanced the growth of Lactobacillus plantarum. Co-cultures of L. plantarum and E. cloacae or P. vulgaris were, by addition of manganese ions, significantly altered in the favour of the former. This finding can be of use in mixed cultures where Enterobacteriaceae act as spoiler microorganisms.     

Effects of metabolic inhibitors on cell lethality and mutation induction in Chinese hamster cells. I. Inhibitors of de novo purine synthesis and a comparison with the effects of caffeine

The effect of pre- and posttreatment incubation of UV-irradiated and ethyl methanesulphonate (EMS) treated cells with non-toxic concentrations of inhibitors of de novo purine synthesis (dnPS) on expression of potentially lethal and premutational damage at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus in V79 cells has been examined. The concentrations of inhibitors used were shown to profoundly perturb de novo DNA synthesis, by measurements of [¹⁴C]formate uptake, and cell cycle progression by flow cytofluorimetry. Postincubation in 6-methyl mercaptopurine ribonucleoside (MMPR) usually but not invariably potentiated the cytotoxic effects of UV and EMS but azaserine (AZS) and methotrexate (MTX) were without effect. No effects on mutant frequencies were observed on posttreatment with any of these agents. Caffeine produced the least effect on dnPS, but invariably potentiated lethal damage. This potentiation of lethal damage is not mediated by dnPS inhibition as has been suggested for Chinese hamster ovary (CHO) cells.     

Trypanosoma cruzi: Responses by cells from infected mice to alloantigens

In unidirectional mixed lymphocyte cultures containing (as responders, stimulators, or regulators) spleen cells from mice infected with Trypanosoma cruzi, alloantigen responses were less than in cultures containing normal spleen cells only. Depletion of plastic adherent cells from infected spleen cells (stimulators or regulators) reversed their inhibitory effect on normal spleen cells (responders); removal of adherent responder cells and/or B lymphocytes did not alter the low alloantigen responses of normal spleen cells (stimulated by infected spleen cells) or infected spleen cells (stimulated by normal spleen cells). Infected spleen cells were effective in regulating mixed lymphocyte cultures only when added at the initiation of the culture. Serum from infected mice suppressed mixed lymphocyte cultures containing responder spleen cells syngeneic to the serum donor if added up to 24 hr after initiation of cultures, whereas the “suppressor serum” had to be present at the initiation of cultures when responder cells were allogeneic to the serum donor. Cultures of infected spleen cells (whole or macrophage enriched) produced a factor which was suppressive when added to mixed lymphocyte cultures containing syngeneic responder cells at initiation. It is proposed that the serum suppressor substance regulates cell-mediated immune responses directly by suppressing the response-potential of cells and indirectly by triggering the release of a factor from adherent splenic cells which induces a hyporesponsive state in T lymphocytes.     

Clastogenic effects of methylnitrosourea and ethylnitrosourea on chromosomes from human fibroblast cell lines.

Human fibroblast cell lines were pulse-treated for 1 h with either methylnitrosourea (MNU) or ethylnitrosourea (ENU) at various time intervals before harvesting for chromosome analysis. Cells treated with 1 X 10(-3) M, 5 X 10(-4) M, and 1 X 10(-4) M final concentrations of MNU and ENU during the G2 or M phases of the cell cycle showed a significant increase in chromatid-type abnormalities over controls. Cells exposed to MNU or ENU 23 h before harvest showed some chromosome-type abnormalities, reflecting probable damage induced during the G1 phase of the cell cycle or derived from chromatid damage induced during the previous cell cycle. The mitotic indices and incidences of abnormalities suggested a dose response effect when cells were treated with the two higher concentrations and the three concentrations, respectively, of MNU or ENU. Chromatid abnormalities were observed in MUN and ENU-treated cells from each of four cell lines. From this investigation, it was concluded that MNU and ENU treatment of human diploid cell lines in vitro induced both chromatid and chromosome aberrations. MNU and ENU, both of which had previously been shown to be mutagenic in experimental animals, are, therefore, also considered to be mutagenic at the chromosome level in human fibroblasts grown and treated in cell culture.     

The effects of ambient flow velocity,colony size,and upstream colonies on the feeding success of bryozoa. I. Bugula stolonifera Ryland,an arborescent species

The effects of ambient flow velocity, colony size, and the presence of upstream colonies on the feeding success of the arborescent bryozoan, Bugula stolonifera (Ryland), were studied. Faster ambient flow velocities were found to reduce feeding of zooids of small colonies but not of large colonies. Zooids from different regions of colonies dominated in feeding at different ambient flow velocities: upstream zooids dominated in feeding from slow ambient flow: zooids from central regions dominated in feeding from fast ambient flow. These results are interpreted with respect to the branching morphology of colonies. Finally, evidence that upstream colonies interfere with the feeding success of zooids of colonies downstream was obtained.     

Fitness costs of worker specialization for ant societies

Division of labour is of fundamental importance for the success of societies, yet little is known about how individual specialization affects the fitness of the group as a whole. While specialized workers may be more efficient in the tasks they perform than generalists, they may also lack the flexibility to respond to rapid shifts in task needs. Such rigidity could impose fitness costs when societies face dynamic and unpredictable events, such as an attack by socially parasitic slavemakers. Here, we experimentally assess the colony-level fitness consequences of behavioural specialization in Temnothorax longispinosus ants that are attacked by the slavemaker ant T. americanus. We manipulated the social organization of 102 T. longispinosus colonies, based on the behavioural responses of all 3842 workers. We find that strict specialization is disadvantageous for a colony''s annual reproduction and growth during slave raids. These fitness costs may favour generalist strategies in dynamic environments, as we also demonstrate that societies exposed to slavemakers in the field show a lower degree of specialization than those originating from slavemaker-free populations. Our findings provide an explanation for the ubiquity of generalists and highlight their importance for the flexibility and functional robustness of entire societies.