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201.
During a 7-10 day span, circadian rhythms of sleep-wake, self-rated fatigue and mood, oral temperature, eye-hand skill and right and left hand grip strength were investigated in eight subjects: five males (21-28 years of age), members of the French sabre fencing team selected for the 1984 Olympic Games in Los Angeles, and three females (19-26 years of age) practicing fleuret (foil) fencing as a sports activity. On the average six measurements/day/variable/subject were performed. The single cosinor method showed that a circadian rhythm was detectable for only 26 out of the 56 time series (46.4%). Power spectrum analysis gave almost the same figure (19 out of 48: 39.5%) with regard to rhythms with τ=24hr indicating that with one exception (subject JFL) rhythms were internally desynchronized including differences τ between right and left hand grip strength rhythms for three subjects. Results suggest: (a) a physiologic synchronization of circadian rhythms may be a predictor of good performance; (b) however, internal desynchronization as shown previously may be a trivial phenomenon and thus does not imply in itself alterations of either health or performance; (c) chronobiologic methods should be recommended for a better understanding of changes in performance by those participating in competitive and other sports.  相似文献   
202.
Antisera have been developed against the wholecell antigens of Desulfovibrio africanus Benghazi and Walvis Bay, D. vulgaris Hildenborough, D. salexigens British Guiana, D. gigas, and D. desulfuricans Essex 6. An enzymelinked immunoadsorption assay (ELISA) was developed to measure the reaction of these antisera with the homologous and heterologous antigens. The ELISA method demonstrated a reaction between pre-immune sera and cells of D. africanus, D. gigas and D. desulfuricans, suggesting the presence of a lectin-like substance on these cell surfaces. Extensive cross-reactions were seen between the antisera and heterologous cells, suggesting the sharing of a number of surface antigens amongst the Desulfovibrio. However, the pattern of these cross-reactions was different from that observed for an ELISA reaction developed for the cytochrome c3 from various Desulfovibrio.Abbreviation ELISA enzyme-linked immunoadsorption assay  相似文献   
203.
Summary The study of mutants of Erwinia specifically unable to ferment cellobiose indicates that the mutations are clustered between arg and ile on the chromosome of this organism. In vivo cloning of the genes responsible for cellobiose utilization lead to a plasmid, pBEC2, which complements all Erwinia Clb- specific mutants. When introduced into wild-type E. coli it allows this organism to use cellobiose, arbutin and salicin; it also complements bglB and bglC mutants of Escherichia coli indicating that arbutin and salicin utilization is due to the products of the pBEC2 cloned genes. From the characterization of mutants pleiotropically affected in the utilization of various carbon sources, including cellobiose, arbutin and salicin, it is proposed that the three--glucosides are substrates of the phosphoenolpyruvate-dependent phosphotransferase system (PTS).  相似文献   
204.
    
Summary Mutations at the URA3 locus of Saccharomyces cerevisiae can be obtained by a positive selection. Wild-type strains of yeast (or ura3 mutant strains containing a plasmid-borne URA3 + gene) are unable to grow on medium containing the pyrimidine analog 5-fluoro-orotic acid, whereas ura3 mutants grow normally. This selection, based on the loss of orotidine-5-phosphate decarboxylase activity seems applicable to a variety of eucaryotic and procaryotic cells.  相似文献   
205.
Summary Hydrogenases are among the main enzymes involved in bacterial anaerobic corrosion of metals. The study of their mode of action is important for a full comprehension of this phenomenon. The three types ofDesulfovibrio hydrogenases [(Fe), (NiFe), (NiFeSe)] present different patterns in the pH dependence of their activity. The periplasmic enzyme fromDesulfovibrio salexigens and the cytoplasmic enzyme fromDesulfovibrio baculatus both have pH optima at 7.5 for H2 uptake and 4.0 for H2 evolution and H+–D2 exchange reaction (measured by membrane-inlet mass-spectrometry). The H2 to HD ratio at pH above 5.0 is higher than 1.0. The periplasmic hydrogenase fromD. gigas presents the same pH optimum (8.0) for the H+–D2 exchange as for H2 consumption. In contrast, the enzyme fromD. vulgaris has the highest activity in H2 production and in the exchange at pH 5.0. Both hydrogenases have a H2-to-HD ratio below 1.0.  相似文献   
206.
Summary Hydrogenase and nitrogenase activities of sulfate-reducing bacteria allow their adaptation to different nutritional habits even under adverse conditions. These exceptional capabilities of adaptation are important factors in the understanding of their predominant role in problems related to anaerobic metal corrosion. Although the D2–H+ exchange reaction indicated thatDesulfovibrio desulfuricans strain Berre-Sol andDesulfovibrio gigas hydrogenases were reversible, the predominant activity in vivo was hydrogen uptake. Hydrogen production was restricted to some particular conditions such as sulfate or nitrogen starvation. Under diazotrophic conditions, a transient hydrogen evolution was followed by uptake when dinitrogen was effectively fixed. In contrast, hydrogen evolution proceeded when acetylene was substituted as the nitrogenase substrate. Hydrogen can thus serve as an electron donor in sulfate reduction and nitrogen metabolism.  相似文献   
207.
Fujita's diagrams in phyllotaxis, showing the frequencies of divergence angles as a function of these angles for low phyllotactic patterns such as (2, 1) and (3, 2), which are approximately normal curves centered at the limitdivergence angle of 137.51°, are shown to be puzzling when compared to results and observations in the field. An analysis of these diagrams is proposed, in the context of Fujita's methodology, of data from other sources, of a mathematical theorem on lattices, and of the contact pressure theory of phyllotaxis.  相似文献   
208.
Summary The organization of Gn-RH systems in the brain of teleosts has been investigated previously by immunohistochemistry using antibodies against the mammalian decapeptide which differs from the teleostean factor. Here, we report the distribution of immunoreactive Gn-RH in the brain of goldfish using antibodies against synthetic teleost peptide.Immunoreactive structures are found along a column extending from the rostral olfactory bulbs to the pituitary stalk. Cell bodies are observed within the olfactory nerves and bulbs, along the ventromedial telencephalon, the ventrolateral preoptic area and the latero-basal hypothalamus. Large perikarya are detected in the dorsal midbrain tegmentum, immediately caudal to the posterior commissure. A prominent pathway was traced from the cells located in the olfactory nerves through the medial olfactory tract and along all the perikarya described above to the pituitary stalk. In the pituitary, projections are restricted to the proximal pars distalis. A second immunoreactive pathway ascends more dorsally in the telencephalon and arches to the periventricular regions of the diencephalon. Part of this pathway forms a periventricular network in the dorsal and posterior hypothalamus, whereas other projections continue caudally to the medulla oblongata and the spinal cord. Lesions of the ventral preoptic area demonstrate that most of the fibers detected in the pituitary originate from the preoptic region.  相似文献   
209.
Virchows Archiv B Cell Pathology - Various parameters of the local cellular response have been studied in 16 laryngeal papillomas from ten patients with recurrent papillomas as well as normal...  相似文献   
210.
Summary Murine monoclonal antibodies (MCAs) against human ovarian tumor associated antigen NB/70K have been prepared. One of these MCAs, NB12123, was chosen for the development of a radioimmunoassay for measuring serum NB/70K levels. In this assay, the average NB/70K level in 75 normal, healthy controls was 11.9 activity units (AU) with an SD of 14.9 AU. The normal cut off value for this assay was set at 45 AU (mean +2 SD). 24 of 46 (52%) ovarian cancer patients, 7 of 18 (39%) patients with benign ovarian cysts or tumors and 3 of 85 (4%) control samples had elevated serum NB/70K levels. Comparison of NB/70K levels measured in the NB12123 assay with levels measured in an assay using a polyclonal antiNB/70K previously developed in our laboratory [13] indicated that although both assays had approximately the same percentage of positive ovarian cancer patient samples, there appeared to be no correlation between the absolute NB/70K levels measured by the two assays. The rank of ovarian cancer patient samples was also different for the two assays. Also, almost 40% of patients with benign ovarian cysts and tumors had elevated serum NB/70K levels as measured by the NB12123 assay as compared to 0% for the polyclonal assay. Reciprocal cross-blocking experiments, absorption studies, and immune precipitate analysis indicated that both the monoclonal NB12123 assay and the polyclonal antiNB/70K assay measured the same population of NB/70K molecules. However, the polyclonal antibody recognizes epitopes in addition to that recognized by NB12123. Taken together, these results suggest that the epitope recognized by NB12123 is not as specific for malignant ovarian tumors as the epitope(s) recognized by polyclonal antiNB/70K and/or that more than the one epitope detected by the MCA is responsible for the specificity for ovarian cancer of the polyclonal NB/70K assay. In spite of this, the greater sensitivity and range of the monoclonal NB12123 assay make it possible to monitor serum NB/70K levels in ovarian cancer patients. In four patients examined, the fluctuating serum NB/70K levels appeared to correlate well with clinical statusSupported in part by ACS # PDT 231 and a grant from the Elsa U. Pardee Foundation  相似文献   
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