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31.
André Morin Jean-Pierre Touzel Alain Lafond Danielle Leblanc 《Applied microbiology and biotechnology》1991,35(4):536-540
Summary Of 373 anaerobic microbial isolates screened for the enzymatic conversion of dihydrouracil to N-carbamyl--alanine, several strains of Clostridium spp., C. glycolicum, C. subterminale and Peptococcus anaerobius were positive. These Clostridium and Peptococcus strains produced also N-carbamyl-d-amino acids from the respective 5-monosubstituted hydantoins. The d-hydantoinase activity from whole cell suspensions of P. anaerobius strain CRDA 303 was characterized with regard to pH and temperature stability and activity by using dihydrouracil (DHU) and isopropylhydantoin (IPH) as substrates. The d-hydantoinase from P. anaerobius was optimal at 60°C and at pH 6.5–9.5 for the substrate DHU. It was stable up to 55°C and at pH 5.0–9.5 and could be stored at 4°C under an aerobic atmosphere for at least 14 days.
Offprint requests to: A. Morin 相似文献
32.
Eric Giraud Alain Brauman Simon Keleke Bertrand Lelong Maurice Raimbault 《Applied microbiology and biotechnology》1991,36(3):379-383
Summary An amylolytic lactic acid bacterium identified as Lactobacillus plantarum was isolated from cassava roots (Manihot esculenta var. Ngansa) during reting. The amylolytic enzyme synthesized was an extracellular -amylase with an optimum pH of 5.0 and an optimum temperature of 55° C. Cultured on starch, the strain displayed a growth rate of 0.43 h–1, a biomass yield of 0.19 g·g–1 and a lactate yield of 0.81 g·g–1. The growth kinetics were similar on starch and glucose. Sufficient enzyme was synthesized and starch hydrolysis was not a limiting factor for growth. Biosynthesis of the enzyme was observed when the glucose concentration was less than 6.7 g·l–1 and reached up to 4 IU·ml–1 at the end of the fermentation.
Offprint requests to: M. Raimbault 相似文献
33.
Clostridium mayombei sp. nov., a previously undescribed H2-oxidizing CO2-reducing acetogenic bacterium, was isolated from gut contents of the African soilfeeding termite, Cubitermes speciosus. Cells were anaerobic, Gram positive, catalase and oxidase negative, endospore-forming motile rods which measured 1×2 – 6 m and which had a DNA base composition of 25.6 mol% G+C (strain SFC-5). Optimum conditions for growth on H2+CO2 were at 33°C and pH 7.3, and under these conditions cells produced acetate according to the equation: 4 H2+2 CO2CH3COOH+2 H2O. Other substrates supporting good growth included carbohydrates (e.g. glucose, xylose, starch), sugar alcohols, and organic and amino acids, and with these substrates acetate was almost always the principle fermentation product. Comparative analysis of 16S rRNA nucleotide sequences confirmed that C. mayombei was closely related to various members of the genus Clostridium. However, morphological and physiological differences between C. mayombei and other homoacetogenic clostridia were deemed significant enough to warrant creation of a new taxon. Results are discussed in light of the diversity of H2/CO2 acetogens recently isolated from various termites, and in terms of the relative importance of H2/CO2 acetogenesis to termite nutrition. 相似文献
34.
Albert Faradji Alain Bohbot Marion Schmitt-Goguel Norbert Roeslin Serge Dumont Marie-Louise Wiesel Christian Lallot Michel Eber Jacques Bartholeyns Philippe Poindron Georges Morand Jean-Paul Witz Francis Oberling 《Cancer immunology, immunotherapy : CII》1991,33(5):319-326
Summary The purpose of this phase I study was to evaluate the toxicity and biological activity of autologous blood-derived macrophages activated ex-vivo with recombinant human interferon (rhuIFN) [monokine-activated killer (MAK) cells] and administered intravenously to 11 lung cancer patients once a week for 6 consecutive weeks. Peripheral blood monocytes were collected by leukapheresis and then purified by counterflow elutriation. The MAK cells were generated by culturing the purified monocytes in Teflon bags for 7 days and adding rhuIFN to the cultured cells for the last 18 h. These MAK cells expressed differentiation-associated surface antigen MAX1, and were cytotoxic in vitro against tumour cell line U937. The MAK cells were infused at dose levels from 1 × 107 to 5 × 108 on an intrapatient dose-escalating schedule. No severe adverse side-effects occurred. Toxicity was mild to moderate [primarly fever (75%) and chills (32%)], non-dose-dependent, and non-cumulative. No consistent change in haemostatic function, or liver or renal function was observed. Dose-limiting toxicity was not reached at 5 × 108 cells (optimal dose reproduced for each patient). The maximum tolerated dose was not determined. The immunomodulatory activity of i.v. infused MAK cells was demonstrated both in vivo by significant increases in granulocyte count and neopterin level in the patients' peripheral blood postinfusion and in vitro by secretory products (IL-1. TNF, neopterin, and thromboplastin-like substance) in the culture supernatants. The in vivo traffic patterns of autologous MAK cells labelled ex-vivo with111In oxine were studied in 7 patients. Gamma imaging showed an immediate but transient lung uptake (<24 h), and a progressive uptake of radioactivity in the liver and spleen was seen from 6 h to 72 h post-infusion. Our results indicate that the preparation of high numbers of autologous, blood-derived MAK cells is a feasible procedure, and their transfusion is safe for patients. This immunotherapeutic approach seems to be encouraging from the point of view of establishing an adjuvant therapeutic modality in cancer patients with minimal residual disease.This work was supported in part by a grant 6911 from the Association pour la Recherche contre le Cancer (ARC), grants from the Ligue Nationale contre le cancer and the Ligues Regionales (Bas-Rhin, Haut-Rhin) contre le cancer, and contract 891013 from the Institut National pour la Santé et la Recherche Médicale (INSERM), France 相似文献
35.
A. Segonzac R. Raisman T. Tateishi H. Schoemaker P. E. Hicks S. Z. Langer 《Journal of neurochemistry》1985,44(2):349-356
Tricyclic antidepressants and nontricyclic serotonin (5-hydroxytryptamine) uptake blockers monophasically inhibit [3H]imipramine binding in human platelets. Similarly, serotonin and tryptamine inhibit the binding of [3H]imipramine in the low micromolar range and with a pseudo-Hill coefficient near unity. Dissociation of the [3H]imipramine receptor complex in the presence of uptake inhibitors follows first-order kinetics with a half-life of approximately 60 min. Although serotonin and tryptamine do not decrease [3H]imipramine binding when added under equilibrium conditions, simultaneous addition of serotonin or tryptamine with serotonin uptake inhibitors decreases the rate of ligand-receptor dissociation in a concentration-dependent manner. These data suggest a common site of action for serotonin, which is the substrate of the transporter system, and of tryptamine, its nonhydroxylated analog. This hypothesis is supported by the identification of a high-affinity (Km = 0.55 microM), saturable, and temperature-dependent uptake of [3H]tryptamine in human platelets. Uptake of [3H]tryptamine was inhibited potently by imipramine and nontricyclic serotonin uptake inhibitors with a potency similar to that observed for [3H]serotonin uptake. These data support the hypothesis that in platelets, [3H]imipramine, tricyclic, and nontricyclic serotonin uptake inhibitors bind to a common recognition site that is associated with the serotonin transporter but that differs from the substrate recognition site of the carrier through which serotonin and tryptamine exert a heterotropic allosteric modulation on [3H]imipramine binding. 相似文献
36.
Gauthier Janel Lacroix Renée Coté Alain Doyon Julien Drolet Michel 《Applied psychophysiology and biofeedback》1985,10(2):139-159
In order to assess the relative effectiveness of finger warming and temporal blood volume pulse reduction biofeedback in the treatment of migraine, 22 female migraine patients were assigned to one of three experimental conditions: temporal artery constriction feedback, finger temperature feedback, or waiting list. Biofeedback training consisted of 12 sessions over a 6-week period. All patients completed 5 weeks of daily self-monitoring of headache activity (frequency, duration, and intensity) and medication before and after treatment. Treatment credibility was assessed at the end of Sessions 1, 6, and 12. Results showed that temporal constriction and finger temperature biofeedback were equally effective in controlling migraine headaches and produced greater benefits than the waiting list condition. Power analyses indicated that very large sample sizes would have been required to detect any significant differences between the two treatment groups. No significant relationships were found between levels of therapeutic gains and levels of thermal or blood volume pulse self-regulation skills. Likewise, treatment outcome was not found to be related to treatment credibility. Further analyses revealed that changes in headache activity and medication were associated with changes in vasomotor variability. Because blood volume pulse variability was not significantly affected by biofeedback training, questions about its role in the therapeutic mechanism are raised.This research was supported in part by grants from the Quebec Ministry of Education and the Quebec Ministery of Social Affairs to the first author, and an award from the Medical Research Council of Canada to the second author. The authors are indebted to Drs. Frank Andrasik, Howard Barbaree, Edward Blanchard, Martin Ford, and Patrick McGrath, as well as to two anonymous reviewers, for their helpful comments on an earlier draft of this paper. 相似文献
37.
Circadian Rhythms in Competitive Sabre Fencers: Internal Desynchronization and Performance 总被引:1,自引:0,他引:1
Alain Reinberg Sylvie Proux Jean Pierre Bartal Francis L vi Alena Bicakova-rocher 《Chronobiology international》1985,2(3):195-201
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
38.
Florence Bettens Flemming Kristensen Guy D. Bonnard Alain L. de Weck 《Cellular immunology》1984,86(2):337-346
The question of whether lymphocytes which have once been activated and have completed one or several cell cycle(s) can return to the G0 phase and stay ready for a new activation (G0-G1 transition), rather than simply die, was investigated. To do so interleukin 2 (IL-2) was removed from cultures of continuously proliferating human T lymphocytes and the formation of resting (G0) cells was measured. Kinetic analyses in freshly prepared peripheral blood lymphocytes (PBL) revealed that the onset of detectable RNA synthesis and the appearance of structures binding the anti-Tac antibody occurred simultaneously. This allowed the expansion of the definition of G0 T lymphocytes as cells having a low RNA (and DNA) content, and no Tac antigen. When cultured human T cells proliferating continuously by means of IL-2 were characterized in terms of their distribution in the cell cycle, 7 days after the initial PHA stimulation, it could be demonstrated that very few cells were in the G0 phase, supporting the concept of direct S/G2/M-G1 transition. However, when IL-2 was removed from the cultures, the [3H]thymidine incorporation per 104 cells and correspondingly the number of cells in the S/G2/M and G1 phases were reduced drastically and during the following 72-hr period, the number of G0 cells increased markedly. Restimulation of such in vitro formed G0 cells, under conditions permitting observation of their shift from the G0 to G0 phase, demonstrated that most cells could respond normally. Based on these observations, it was concluded that IL-2 not only ensures T-lymphocyte survival and proliferation, but IL-2 starvation induces many continuously proliferating T lymphocytes to stop cycling and to return to the G0 phase of the cell cycle where they remain functional. 相似文献
39.
Meria E. Penttilä K. M. Helena Nevalainen Alain Raynal Jonathan K. C. Knowles 《Molecular & general genetics : MGG》1984,194(3):494-499
Summary The possibility of cloning filamentous fungal genes by expression in the yeast Saccharomyces cerevisiae has been studied. A genome bank of Aspergillus niger was made in E. coli using a yeast cosmid shuttle vector and over 10,000 different cosmid clones were individually isolated. Yeast transformants carrying Aspergillus DNA were screened for the expression of the genes for fungal secreted glycoproteins, -galactosidase, -glucosidase, and amyloglucosidase, and for the expression of fungal genes complementing yeast ura3 and leu2 mutations.Of the five Aspergillus genes studied, only one, -glucosidase, was found to be expressed in yeast, and this at a low level. This suggests that there are essential differences between the genes of yeast and filamentous fungi. 相似文献
40.
Stimulation of de novo synthesis of δ-aminolevulinate dehydralasc of radishes grown under far-red light .
Density labelling studies of δ-aminolevulinate dehydratase (ALAD) in cotyledons of radish ( Raphanus sativus L. cv. Longue Rave Saumonée) seedlings demonstrate that far-red light stimulates de novo synthesis of ALAD and that the turn-over of this enzyme is very poor. Cycloheximide reduces considerably both the increase of ALAD activity and the incorporation of deuterium in ALAD, which indicates that ALAD synthesis depends upon cytoplasmic ribosomes. 相似文献
Density labelling studies of δ-aminolevulinate dehydratase (ALAD) in cotyledons of radish ( Raphanus sativus L. cv. Longue Rave Saumonée) seedlings demonstrate that far-red light stimulates de novo synthesis of ALAD and that the turn-over of this enzyme is very poor. Cycloheximide reduces considerably both the increase of ALAD activity and the incorporation of deuterium in ALAD, which indicates that ALAD synthesis depends upon cytoplasmic ribosomes. 相似文献