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901.
Cell cycle specificity of tumor necrosis factor and its receptor 总被引:1,自引:0,他引:1
N Watanabe Y Niitsu N Yamauchi H Neda H Sone M Maeda I Urushizaki 《Cell biology international reports》1987,11(11):813-817
Phase specificity in the TNF cytotoxic effect and the number of TNF binding receptors was investigated using L-M cells incubated synchronously from the S phase. TNF cytotoxicity was observed to occur at various levels during the cell cycle, with peak effect in the G2-M phase. Analysis with 125I-labeled TNF to determine the number of receptors binding TNF in the various cell phases shewed a phase specificity with the maximum number occurring in the G2-M phase, similar to the peak in cytotoxicity. The results suggest the existence of a cell cycle specificity in the cytotoxicity of TNF which is apparently related to changes in the number of receptors capable of binding TNF. 相似文献
902.
903.
Mononuclear cells concentrated from 11 patients with chronic lymphocytic leukemia (CLL), 7 with non-Hodgkin's lymphoma in leukemic phase (NHL), 5 with hairy cell leukemia (HCL), 1 with prolymphocytic leukemia (PLL), and 1 with plasma cell leukemia (PCL) were induced to differentiate with various doses of TPA. The degree of induction was followed for up to 6 days by measuring the expression of surface membrane markers (SmIg and GP-70) and Ig secretion, the induction of tartrate-resistant acid phosphatase (TRAP) and by recording ultrastructural changes as seen by electronmicroscopy. The results show a dose and time dependency of the TPA effect and a great heterogeneity in the cellular response, particularly in cells obtained from B-CLL patients. TPA induced two main features, namely the development of "plasmacytoid" or "hairy cell" leukemia features that clearly depended on the dose and duration of treatment with the phorbol ester. The plasmacytoid features were more frequently encountered with lower doses (1 ng/ml) of TPA and were more evident after shorter exposures to TPA (1-2 days). Nevertheless, the hairy cell features were more striking after incubation with higher concentrations of TPA (10-100 ng/ml) after longer periods of incubation (up to 6 days) with lower doses of TPA. The various features of differentiation measured including cell morphology, surface membrane markers, Ig secretion, and TRAP staining, were frequently independent of each other, suggesting an autonomous pathway of differentiation for some of these features. Furthermore, in most of the cases, hairy cell leukemia features were obtained more frequently following TPA exposure than plasmacytic changes. 相似文献
904.
Summary Posttreatment with sodium arsenite in log phase synergistically increases the chromosomal aberrations induced by ethyl methanesulfonate in Chinese hamster ovary cells, human fibroblasts, and human lymphocytes. However, posttreatment with sodium arsenite in stationary phase has no apparent effect on the clastogenicity of ethyl methanesulfonate. These results indicate that the cycling state of the cell plays a crucial role in the action of arsenite coclastogenicity. One prediction from this finding is that in combined treatment, posttreatment with sodium arsenite should preferentially kill cancer cells. 相似文献
905.
Assignment of the human gamma-glutamyl transferase gene to the long arm of chromosome 22 总被引:3,自引:0,他引:3
F. Bulle M. G. Mattei S. Siegrist A. Pawlak E. Passage M. N. Chobert Y. Laperche G. Guellaën 《Human genetics》1987,76(3):283-286
Summary We have determined the chromosomal location of the human gene for gamma-glutamyltransferase (GGT). This study was done by in situ hybridization of human metaphase spreads with a rat cDNA probe specific for this enzyme and constructed from two clones previously characterized in our laboratory. The final construct had a 1.6-kb-long insert covering 92% of the coding sequence for GGT. The new insert was also freed of any GC tails introduced for the cDNA cloning, because we observed that these sequences were responsible for a high background. Using this probe for the analysis of 136 human metaphase spreads, we observed a strong specific signal on chromosome 22 at the interface of q111-112 and a minor peak in q131. Thus GGT might represent a new marker for the study of certain diseases which have chromosomal abnormalities at these loci. 相似文献
906.
Yéronique Blanquet Catherine Turleau Nicole Créau-Goldberg Chantal Cochet J. de Grouchy 《Human genetics》1987,76(1):102-105
Summary The two probes H3-8 and H2-42, known to be located in 13q14, were mapped by in situ hybridization to either side of the 13 breakpoint of an apparently balanced de novo t(2;13)(p24.3;q14.2) detected in a patient with retinoblastoma as the only phenotypic manifestation. 相似文献
907.
Analysis of nucleotide sequences of two ligninase cDNAs from a white-rot filamentous fungus, Phanerochaete chrysosporium 总被引:15,自引:0,他引:15
An analysis of nucleotide sequences of two types of ligninase cDNAs isolated from the basidiomycete Phanerochaete chrysosporium, designated CLG4 and CLG5, are presented here. The amino acid sequences of the corresponding ligninase proteins, designated LG4 and LG5, respectively, have been deduced from the cDNA sequences. Mature ligninases LG4 and LG5 are preceded by leader sequences containing 28 and 27 amino acids (aa), respectively, and each contains 344 aa residues. The estimated Mrs of mature LG4 and LG5 are 36,540 and 36,607, respectively. Potential N-glycosylation site(s) with the general sequence Asn-X-Thr/Ser are found in both LG4 and LG5. Nucleotide sequence homology between the coding region of CLG4 and CLG5 is 71.5%, whereas the amino acid sequence homology between the two ligninases is 68.5%. The codon usage of ligninases is extremely biased in favor of codons rich in cytosine and guanine. Amino acid sequences of two tryptic peptides of ligninase H8 have exactly matching sequences in ligninase LG5. Also, the sequences of the oligodeoxynucleotide probes, which correspond to the sequences in the tryptic peptides of ligninase H8 and which were used in isolating the ligninase clones from the cDNA library, have exactly matching sequences in CLG5. The experimentally determined N-terminal sequence of purified ligninase H8 is found in the deduced N-terminal amino acid sequence of LG5. These results suggest that CLG5 encodes ligninase H8 and that CLG4 represents a related but different ligninase gene. 相似文献
908.
S. Y. Ahmed B. K. Lonsane N. P. Ghildyal S. V. Ramakrishna 《Biotechnology Techniques》1987,1(2):97-102
Summary A large scale solid state fermentor of 150 tray capacity is designed with appropriate control system. It gave better productivity even at higher scale of operation as compared to lab and large scale units of similar type and largely overcomes some operational problems. 相似文献
909.
Summary N2-fixing bacteria were isolated from the rhizosphere of naturally grown salt tolerant grass (Leptochloa fusca). A broad spectrum of diazotrophs was found to be associated with the roots ofL. fusca. the systematic position of the three isolates, NIAB-1, C-2 and Iso-2 was determined by morphological, biochemical and mol % (G+C) DNA contents. Two isolates were identified asKlebsiella pneumoniae (NIAB-1) andBeijerinckia sp. (Iso-2).15N enrichment studies confirmed the nitrogen fixing ability of the isolates. The effects of different levels of combined nitrogen (NO
3
–
& NH
4
+
), pH (5.5–9.0) and salt (NaCl) on nitrogenase activity of the isolates were determined at various time intervals. All isolates exhibited nitrogenase activity even in the presence of 5 mmol/l NO
3
–
or NH
4
+
in a semi-solid medium after 24 h of growth. Maximum nitrogenase activity was observed at alkaline pH and all isolates were able to tolerate up to 3% NaCl in the medium.
Resumen Se han aíslado bacterias fijadoras de N2 en la rizosfera del hábitat natural de la graminea halófilaLeptochloa fusca. Un amplio espectro de diazotrofos se encontró asociado con las raíces deL. fusca. La posición sistemática de tres aíslados: NIAB-1, C-2 y Iso-2 se determinó utilizando sus características morfológicas, bioquímicas y el % (G+C) molar del ADN. El aíslado NIAB-1 se identificó comoKlebsiella pneumoniae y el aíslado Iso-2 comoBeijerinckia. sp. Estudios mediante15N confirmaron la habilidad fijadora de N2 de los aíslados. Se determinaron periodicamente los efectos de distintos niveles de nitrógeno combinado (NO3 – y NH4 +), pH (5.5–9.0) y sal (NaCl) en la actividad nitrogenásica de los aíslados. Todas las cepas aísladas mostraron actividad nitrogenásica incluso en presencia de 5mmol/l de NO3 – y NH4 + en un medio semisólido desqués de 24 h. de crecimiento. La actividad nitrogenásica máxima se observó a pH alcalino y todos loa aíslados eran capaces de tolerar hasta 3% de NaCl en el medio.
Résumé Des bactéries fixatrices de l'azote ont été isolées à partir de la rhizosphère de l'herbe halotoléranteLeptochloa fusca développée dans les conditions naturelles. Il a été constaté qu'un large spectre de diazotrophes est associé aux racines de la plante. La position taxonomique de 3 souches isolées, NIAB-1, C-2 et Iso-2, a été déterminée par des critères morphologiques et biochimiques et par le pourcentage de (G+C) de l'ADN. Deux souches on été identifiées commeKlebsiella pneumoniae (NIAB-1) etBeijerinckia sp. (Iso-2). Les études d'enrichissement en15N ont confirmé l'aptitude des souches à fixer l'azote. les effets de différents niveaux d'azote combiné (NO3 – et NH4 +), de pH (5.5–9.0) et de sel (NaCl) sur l'activité nitrogénasique des souches ont été déterminés à divers intervalles de temps. Toutes les souches présentent une activité nitrogènase après 24 h de croissance en milieu semi-solide, et cela même en présence de 5 mmol/l de NO3 – ou NH4 +. L'activité nitrogènase maximum est observée à pH alcalin, et toutes les souches tolèrent jusqu'à 3% de NaCl dans le milieu.相似文献
910.
Summary
Vigna unguiculata cv. 58–185 grown in a sterile Dek soil was inoculated withRhizobium sp. orRhizobium sp. plusGlomus mosseae. Response of the host plant to the treatments was estimated by periodic measurements of shoot and nodule dry weights, N2 fixation (C2H2 reduction activity) and N and P contents up to the 50th day of the growth cycle. It was only 45 days after planting that shoot dry weight of dually inoculated plants differed significantly from that of plants inoculated withRhizobium sp. alone. Nodule dry weight and N2 fixation of dually inoculated plants were significantly higher than those of plants inoculated withRhizobium sp. alone from day 20 after planting, but there was no significant difference in N content (%). During the first 20 days, shoot P content (%) of both sets of plants decreased progressively, P content of dually inoculated plants being lower than that of the others. Later, P content of dually inoculated plants increased rapidly whereas P content of the other plants remained constant. Increase in nodule dry weight, N2 fixation and P content of dually inoculated plants corresponded to the onset of the development of the extra-radical hyphae ofGlomus mosseae. In the rhizosphere.
Resumen Se cultivóVigna unguiculata cv. 58–185 en un suelo estéril tipo Dek, se inoculó conRhizobium sp. o conRhizobium sp. másGlomus mosseae. La respuesta de la planta huésped a los tratamientos se estudió midiendo periodicamente el peso seco de la parte aerea y de los nódulos, la fijación de N (actividad reductora de C2H2) y los contenidos de N y P hasta el 50° día del ciclo de crecimiento. La diferencia entre el peso seco de la parte aerea de las plantas con doble inoculación y aquellas inoculadas conRhizobium sp. unicamente, no fue significativa hasta 45 días despúés de la siembra. A los 20 días de la siembra tanto el peso seco de los nódulos como la fijación de nitrógeno de las plantas con doble inoculación eran significativamente superiores a los valores obtenidos para las plantas con soloRhizobium sp., aunque no se observaron diferencias en el contenido en N (%). Durante los primeros 20 días del ciclo el contenido en P (%) de ambos grupos de plantas disminuyó progresivamente, siendo los valores obtenidos por las plantas con doble inoculación inferiores a los de las demás. Más tarde el contenido en P de las plantas con doble inoculación aumentó rapidamente manteniéndose constante el de las demás. El incremento en el peso seco de los nódulos, en la fijación de N y en el contenido en P de las plantas con doble inoculación se correspondió con el inicio del desarrollo de las hifas extraradiculares deGlomus mosseae.
Résumé On a inoculéV. unguiculata poussant dans un sol Dek stérile avecRhizobium etRhizobium plusGlomus mosseae. On a recherché la réponse de la plante-hôte à ces deux traitements en estimant périodiquement les poids des nodules et des parties aériennes de la plante, la fixation d'azote (activité réductrice de C2H2), les teneurs en N et P jusqu'au 50e jour du cycle de végétation. C'est seulement au 45e jour après la plantation que le poids sec des parties aériennes des plantes inoculées avec deux symbiotes (plantes doublement inoculées) diffère significativement de celui des plantes inoculées avec Rhizobium seul. Le poids sec des nodules et la fixation N2 des plantes doublement inoculées sont significativement plus élevés que ceux des plantes inoculées avecRhizobium seul au 20e jour après la plantation mais il n'y a pas de différence significative pour la teneur en N (%). Pendant les 20 premiers jours, la teneur en P (%) des parties aériennes des deux catégories de plantes décroit progressivement; la teneur en P des plantes doublement inoculées est plus faible que celle des plantes inoculées seulement avecRhizobium. Plus tard, la teneur en P des plantes doublement inoculées augmente rapidement tandis que celle des autres plantes reste constante. L'accroissement du poids sec des nodules, de la fixation d'azote et de la teneur en P observé chez les plantes doublement inoculées correspond au démarrage du développement des hyphes extra-radicales deGlomus mosseae dans la rhizosphère.相似文献