不同剂量的抗孕-53和18-甲基炔诺酮对大鼠垂体机能反应性影响的比较

为了研究甾体避孕药对垂体生殖激素的影响,本实验以动情前期大鼠受二次静脉注射GnRH诱发的LH激发效应(priming effect)为模型,观察经肌肉注射不同类型、不同剂量的避孕药(抗孕-53或18-甲基炔诺酮)后垂体对GnRH的敏感性反应。抗孕-53的剂量为3,1.5,0.75,0.375和0.19mg;l8-甲基炔诺酮的剂量为4,1和0.5mg,各溶于0.5ml茶油;对照组为0.5ml茶油。实验结果表明,不同剂量的抗孕-53均促进血浆LH浓度升高,其中以3mg组的反应最显著,与对照组比较P<0.01。不同剂量的18-甲基炔诺酮对垂体敏感性均有显著的抑制作用,使血浆LH浓度降低(P<0.01)。大鼠经肌肉注射乙炔雌二醇21μg和10.5μg后,其垂体对GnRH的反应也有促进作用,但不能完全模拟抗孕-53的效应。上述结果表明,不同类型的甾体避孕药能增加或降低大鼠垂体对GnRH的敏感性。     

Climate-driven changes in abundance and distribution of larvae of oceanic fishes in the southern California region

We examined climatic effects on the geographic distribution and abundance of 34 dominant oceanic fishes in the southern California region using larval fish data collected from the 50‐year long California Cooperative Oceanic Fisheries Investigations (CalCOFI) surveys. The oceanic species responses to environmental changes in their geographic distributions were not very pronounced, perhaps because they lived in the deep layer where temperature change was relatively small or because the environmental variation of the CalCOFI region is not strong enough (with an average temperature gradient of the upper 100 m around 91 km °C^?1). Among the 34 taxa, 16 showed a significant distributional shift (median latitude or boundaries) in relation to environmental variables, and eight species significantly shifted their geographic distribution from the 1951–1976 cold period to the 1977–1998 warm period. Interestingly, the vertically migrating taxa more often showed a significant response to environmental variables than the nonmigrating mesopelagic taxa, reflecting the more significant increase in heat content of the upper ocean (<200 m), compared with the deeper zone (300–500 m) where the mesopelagic fishes typically remain. Climate change has significant effects on the abundances of oceanic fishes. Twenty‐four taxa exhibited a significant change in abundance in relation to environmental variables, and 25 taxa, including both warm and cold‐water taxa, showed a significant increase in abundance from the cold to warm period. Analysis of physical data indicated that the surface‐layer (20–200 m) warmed significantly and the isotherms approached shoreward from the cold to the warm period. We further show that the spatial distribution of coastal–neritic fish retreated shoreward and oceanic fish extended shoreward from the cold to warm period. Our results suggest intensified stratification of the southern California region during the warm period may create a suitable habitat for the oceanic species. Moreover, such an unfavorable condition (e.g. changes in food habitat) for coastal–neritic species might result in competitive release for the oceanic fishes to flourish.     

Longitudinal variation in food sources and their use by aquatic fauna along a subtropical river in Taiwan

1. River food webs rely on two major food sources: autochthonous primary production within the river and allochthonous organic matter transferred to the river. We characterised the consumer communities and assessed the food sources of dominant consumers along a subtropical mountainous river (the Lanyang River of north‐eastern Taiwan) at the catchment scale from the headwater to the estuary using natural abundances of stable carbon and nitrogen isotopes. 2. The downstream transport of fine particulate organic matter (FPOM) was two orders of magnitude greater than that of coarse particulate organic matter (CPOM). Transport of both materials increased from the headwater and reached a maximum in the midstream reach. CPOM composition exhibited a gradual shift from leaves and branches in the headwater, an area characterised by high canopy cover, to algae in the midstream reaches and marsh plants in the downstream reaches. 3. Consumer communities can be classified into two regional categories: the upland category in the headwater and upstream and midstream reaches and the lowland category comprised of samples from the downstream reach and estuary. The upland category revealed a clear and gradual seasonal shift in community composition, but a seasonal shift was not apparent for the lowland category. Nutrient concentrations and water temperature were the main factors explaining longitudinal and seasonal variations. 4. The use of sources of organic matter by dominant consumers along the Lanyang River was primarily determined by their availability. Riparian C₃ plants were the major food sources in the headwater, upstream reach and estuary, but the contribution of periphyton increased in the upper midstream reach where the river flows through an agricultural area. In the lower midstream and downstream reaches, the contribution of riparian C₄ plants became dominant. 5. The trophic transfer of organic materials in the Lanyang River may be influenced by the fast current velocity and by sewage nutrient loading in the river, both of which have important implications for predicting how the functioning of subtropical river food webs will respond to human‐related changes in land use.     

厉蚤属在我国的首次纪录及一新亚种记述(蚤目:多毛蚤科)

厉蚤属(Xcnodaeria Jordan,1932)的建立系根据从锡金的斑林狸(Prionodon paradicotor Hodgson)体上采到的一只雄蚤,描述为后厉蚤(Xenodaeria telios Jordan,1932)为模式种。迄今只有这一种。至1966年,Hopkins和Rothschild在《英国自然博物馆蚤类目录》第四卷86页脚注中提到,Traub在喜马拉雅山较低处,具有古北界动物区系的几个地方得到本种,由此证实了以前认为印度次大陆具有古北界动物地理特征的说法。并认为其真正宿主可能是鼩鼱。     

EVALUATION OF CORD FORMATION IN KINYOUN-STAINED SMEARS OF MGIT CULTURES AS A RAPID IDENTIFICATION METHOD FOR MYCOBACTERIUM TUBERCULOSIS COMPLEX

Tuberculosis (TB) is a major cause of morbidity and mortality worldwide. One hundred and nineteen acid-fast bacilli-positive smears for Mycobacterium Growth Indicator Tube cultures from 119 patients were examined by microscopy for the presence of cord formation. The results were compared with those of the traditional TB identification method, IS6110 polymerase chain reaction (PCR) , and the Capilia TB assay which uses a monoclonal antibody to identify. With the traditional TB identification method, 57 of these 119 specimens were determined to be positive for Mycobacterium tuberculosis complex, and the organisms in the remaining 62 specimens were identified as non-tuberculosis mycobacteria (NTM). Both IS6110 PCR and the Capilia TB assay yielded results identical to those of the traditional method with 57 true TB and 62 NTM. For the cord formation assay, all 62 NTM cultures were negative, but 54 of the 57 true TB cultures were positive. Therefore, the cord formation method had a sensitivity of 94.74% (54/57), specificity of 100% (62/62), negative predictive value of 95.38% (62/65) and positive predictive value of 100% (54/54) for identification of M. tuberculosis complex. The cord formation method is less expensive and 3–5 weeks quicker than the biochemical tests in the identification of M. tuberculosis.

PRACTICAL APPLICATIONS

Due to the slow growth of Mycobacterium tuberculosis bacilli, delays in the detection of TB infection may occur in clinical TB laboratories when only conventional methods for recovery of mycobacteria are used. This problem can be supported by other techniques, such as cord formation in Kinyoun-stained smears of Mycobacterium Growth Indicator Tube cultures and molecular biology-based systems, which can be used in combination to obtain accurate results in a much shorter period of time.     

厦门丽蝇科麻蝇科及家蝇料记录

作者于1954年11月即开始采集蝇类,旋即中断,仅得常见种7种。至1956年5月又重新开始,迄1957年5月,共得蝇类39种,分隶于丽蝇、麻蝇及家蝇3科,今记录如下:     

Proinflammatory cytokine responses induced by influenza A (H5N1) viruses in primary human alveolar and bronchial epithelial cells

Background

Fatal human respiratory disease associated with influenza A subtype H5N1 has been documented in Hong Kong, and more recently in Vietnam, Thailand and Cambodia. We previously demonstrated that patients with H5N1 disease had unusually high serum levels of IP-10 (interferon-gamma-inducible protein-10). Furthermore, when compared with human influenza virus subtype H1N1, the H5N1 viruses in 1997 (A/Hong Kong/483/97) (H5N1/97) were more potent inducers of pro-inflammatory cytokines (e.g. tumor necrosis factor-a) and chemokines (e.g. IP-10) from primary human macrophages in vitro, which suggests that cytokines dysregulation may play a role in pathogenesis of H5N1 disease. Since respiratory epithelial cells are the primary target cell for replication of influenza viruses, it is pertinent to investigate the cytokine induction profile of H5N1 viruses in these cells.

Methods

We used quantitative RT-PCR and ELISA to compare the profile of cytokine and chemokine gene expression induced by H5N1 viruses A/HK/483/97 (H5N1/97), A/Vietnam/1194/04 and A/Vietnam/3046/04 (both H5N1/04) with that of human H1N1 virus in human primary alveolar and bronchial epithelial cells in vitro.

Results

We demonstrated that in comparison to human H1N1 viruses, H5N1/97 and H5N1/04 viruses were more potent inducers of IP-10, interferon beta, RANTES (regulated on activation, normal T cell expressed and secreted) and interleukin 6 (IL-6) in primary human alveolar and bronchial epithelial cells in vitro. Recent H5N1 viruses from Vietnam (H5N1/04) appeared to be even more potent at inducing IP-10 than H5N1/97 virus.

Conclusion

The H5N1/97 and H5N1/04 subtype influenza A viruses are more potent inducers of proinflammatory cytokines and chemokines in primary human respiratory epithelial cells than subtype H1N1 virus. We suggest that this hyper-induction of cytokines may be relevant to the pathogenesis of human H5N1 disease.     

New conformational constraints in isotopically (13C) enriched oligosaccharides

Multidimensional heteronuclear NMR studies have been applied to the resonance assignment and conformational analysis of 13C-enriched Neu5Acalpha2-3Galbeta1-4Glc. It is demonstrated that three-dimensional ROESY-HSQC experiments provide through-space distance restraints which cannot be observed with conventional homonuclear 1H techniques due to resonance overlap. In particular, connectivities demonstrating the existence of the "anti" conformation about the Galbeta1-4Glc glycosidic linkage are unambiguously observed. It is shown that 13C isotopic enrichment of the trisaccharide at a level >95% enables straightforward measurement of trans-glycosidic 1H-13C and 13C-13C coupling constants and a Karplus-type relation is derived for the latter. In total 15 conformational restraints were obtained for the trisaccharide in aqueous solution, all of which were in excellent agreement with theoretical parameters computed from a 5 ns molecular dynamics simulation of the glycan.