Detection of Staphylococcal Enterotoxin A,B, and C in Milk By an Elisa Procedure

Enterotoxigenic reference strains of Staphylococcus aureus were cultivated in sterile whole and skim milk for 18 h at 37°G. Staphylococcal enterotoxin A, B, and C were detected directly in the milk by an enzyme linked immunosorbent assay (ELISA), sensitive down to 1 ng/ml. Enterotoxins in the range of 1 ng–20 µg/ml milk were detected without any concentration or extraction. Skim and whole milk were almost identical as medium for enterotoxin production.     

Integrated species delimitation and conservation implications of an endangered weevil Pachyrhynchus sonani (Coleoptera: Curculionidae) in Green and Orchid Islands of Taiwan

Oceanic islands are productive habitats for generating new species and high endemism, which is primarily due to their geographical isolation, smaller population sizes and local adaptation. However, the short divergence times and subtle morphological or ecological divergence of insular organisms may obscure species identity, so the cryptic endemism on islands may be underestimated. The endangered weevil Pachyrhynchus sonani Kôno (Coleoptera: Curculionidae: Entiminae: Pachyrhynchini) is endemic to Green Island and Orchid Island of the Taiwan‐Luzon Archipelago and displays widespread variation in coloration and host range, thus raising questions regarding its species boundaries and degree of cryptic diversity. We tested the species boundaries of P. sonani using an integrated approach that combined morphological (body size and shape, genital shape, coloration and cuticular scale), genetic (four genes and restriction site‐associated DNA sequencing, RAD‐seq) and ecological (host range and distribution) diversity. The results indicated that all the morphological datasets for male P. sonani, except for the colour spectrum, reveal overlapping but statistically significant differences between islands. In contrast, the morphology of the female P. sonani showed minimum divergence between island populations. The populations of P. sonani on the two islands were significantly different in their host ranges, and the genetic clustering and phylogenies of P. sonani established two valid evolutionary species. Integrated species delimitation combining morphological, molecular and ecological characters supported two distinct species of P. sonani from Green Island and Orchid Island. The Green Island population was described as P. jitanasaius sp.n. Chen & Lin, and it is recommended that its threatened conservation status be recognized. Our findings suggest that the inter‐island speciation of endemic organisms inhabiting both islands may be more common than previously thought, and they highlight the possibility that the cryptic diversity of small oceanic islands may still be largely underestimated.     

厦门地区鸭鹅绦虫生活史研究

本文报告了福建厦门地区寄生于鸭鹅类的膜壳科绦虫计5属9种。实验阐明了5种绦虫的生活史,其中有三种生活史为我国首次报告。厦门地区有5种嵌水甲壳类可作膜壳绦虫的中间宿主。其中短角异剑水蚤(Apocyclops royi)是矛形剑带绦虫和片形皱缘绦虫的审间宿主,不等异介虫(Heterocypris anomala)为新发现的棘盘双睾绦虫的中间宿主,介虫(Cyprinotus sp.)为新发现的美丽膜壳绦虫的中间宿主。     

Microclimates and water budget of algae,lichens and a moss on some nunataks in Queen Maud Land

During the Norwegian Antarctic Expedition of 1984–1985, land parties worked in the area of Mühlig-Hofmannfjella and Gjelsvikfjella in Queen Maud Land (5° 20E, 1° 37W, 1000–1600 m a.s.l.). The nunataks in this area, which represents one of the climatic limits for terrestrial life on earth, is among those areas absorbing the highest quantity of shortwave radiation during a period of 24 h in summer. In spite of this the air temperature never, or very seldom, exceeds 0° C. The limiting factor for photosynthesis over most of the summer was water availability. Melt-water plays an important role in spring. During rest of the growth season, water from condensation is probably the most important water source for plants. On calm nights the rate of condensation during 6 h may reach 0.5 mm, which constitutes only 10%–30% of daily potential evapotranspiration. Plants situated in narrow clefts or shielded by stone blocks have the highest rate of potential photosynthesis. These locations are shielded from direct solar radiation most of the time, but the radiation from surrounding stone surfaces is higher than from the atmosphere and heat loss by turbulence is smaller than for exposed locations. These locations also probably have the highest rate of actual photosynthesis.     

Ha-ras-1 alleles in Norwegian lung cancer patients

Summary We have examined DNA restriction fragment length polymorphisms (RFLP) of the Ha-ras-1 gene in DNA from 118 lung cancer patients and 123 unaffected controls. When DNA samples were digested with MspI/ HpaII restriction endonucleases. Southern blot analysis demonstrated 4 common, 4 intermediate and 7 different rare alleles in the combined population after hybridization to the pGDa1 probe. Six of the rare alleles were unique for the lung cancer group and 1 rare allele for the control group. The frequency of rare alleles in lung cancer patients (10/236) was significantly different (P<0.01) from the control group (1/246). The lung cancer group also had a significantly lower frequency of the common 2.57 kb fragment than the controls (P<0.02). The results thus indicate that Ha-ras genotyping may be of value in lung cancer risk assessment.     

肾神经在扩张心房时对尿量和尿钠排出的作用

单侧肾去神经的麻醉狗,用乳胶小囊扩张肺静脉-心房连接部,观察到神经完好肾的尿流量与排钠量均显著增加(P<0.01);去神经肾的尿流量仍显著增加(P<0 01),但排钠量无明显变化(P>0.05);两侧肾的肾小球滤过率(GFR)及肾血浆流量(RPF)均保持稳定;神经完好肾的静脉血浆肾素活性(PRA)及血管紧张素Ⅱ水平(PAⅡ)均明显降低,PAⅡ降低的幅度与尿流量增加的幅度无相关(r=-0.2975,P>0.05);与排钠量增加的幅度也无相关(r=-0.2359,P>0.05);去神经肾的PRA和PAⅡ都没有显著变化。说明在刺激心房感受器引起的利尿与尿钠排泄的反应中,肾神经主要促进肾对尿钠的排出。肾神经的这种作用既不是通过改变GFR和RPF,也不是抑制肾素的释放,而可能是由于直接影响肾小管对钠的重吸收。     

Further studies on the biological characteristics of an endogenous colon mitosis inhibitor: Comparison with some structurally related peptides

Previous work indicates that the colonic epithelial cell proliferation in mice is reversibly inhibited by the tripeptide pGlu-His-GlyOH found in aqueous extracts of the intestine. In the present study we examined the possible tissue specificity of the colon mitosis inhibitor. The mitotic rate in the small intestine, epidermis and forestomach in mice was registered after a single i.p. injection of the tripeptide. A significantly reduced rate of cell renewal was found at 18 h in the epidermis whereas no inhibition was observed in the forestomach or ileal epithelium. To investigate whether the amino acid sequence of the tripeptide is essential for the inhibitory effect, three structurally related bioactive peptides were tested and compared to the effect of CMI. CMI showed a bell-shaped dose-response relationship as previously shown, whereas the mitotic rate was not reduced in the colonie epithelium after treatment with either an epidermal mitosis inhibitory pentapeptide, or the dipeptide pGlu-GlyOH, or an analogue of luteinizing hormone-releasing hormone. The efficacy of the tripeptide was dependent on the basal rate of cell renewal in the colonie epithelium. When the tripeptide was given at the circadian nadir of cell proliferation a delayed reduction of the proliferative activity was observed at 6 h after treatment, whereas treatment when the rate of cell proliferation was at its circadian zenith gave an immediate mitotic inhibition.