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971.
972.
Cecilia Ximénez Emma I. Melendro Amado Gonzalez-Mendoza Ana Ma. García Anastasio Martínez Librado Ortiz-Ortiz 《Mycopathologia》1980,70(2):117-122
Different vaccination procedures to increase the mecha nisms of host resistance to Nocardia brasiliensis were studied in mice. When mice were challenged in the footpad, 2×108
N. brasiliensis 20 days after footpad inoculation with either viable or killed N. brasiliensis, the mice demonstrated significant resistance to infection when compared with noninfected and nonimmunized mice. The degree of resistance seems to be correlated with the delayed-type hypersensitivity response in the vaccinated animals. Vaccination with another acid-fast bacilli, BCG, afforded both a mild protection and low DTH reactivity. Antibody levels to Nocardia were similar in either Nocardia- or BCG- treated groups indicating that they do not play an important role in resistance to infection by N. brasiliensis. 相似文献
973.
G Riondino F Strollo T Di Cesare N Cospito R Marini G Perniciaro 《Bollettino della Società italiana di biologia sperimentale》1981,57(23):2331-2337
PRL plasma levels and FSH and LH pituitary reserve were tested in ten apparently healthy male subjects. A good correlation was found between PRL on one hand and FSH plasma levels (p less than 0,05), LH plasma levels (p less than 0,01) and FSH pituitary reserve (p less than 0,01) on the other hand. This seems to support the current hypothesis that prolactin may cause a progressive clinically latent impairment in the spermatogenetic function of the testis. Further evidence is needed. 相似文献
974.
975.
Enrique Figueroa Rodolfo Vallejos Ariana Pfeifer Cecilia Kahler 《The Biochemical journal》1966,98(1):253-259
1. Glycogen synthesized by rat-liver slices 0.5mm. thick incubated at 1atm. oxygen pressure in Hastings medium with glucose was localized in the cells of the periphery of the slice. Cells of the interior of this slice do not synthesize glycogen. 2. Inner cells of thin slices (about 0.3mm. thick) can synthesize glycogen when such slices are incubated under the same conditions, but oxygen pressures higher than 1atm. are required if inner cells of slices 0.5mm. or more thick are to be able to synthesize glycogen. 3. Localization of newly synthesized glycogen in rat-liver slices incubated in Hastings medium with glucose does not depend on glucose concentration. 4. Calculation of the minimum oxygen pressure required to synthesize glycogen gives values between 0.09 and 0.17atm. 5. The advantages of high oxygen pressures for the study of the synthesis of glycogen and other compounds that require ATP are discussed. 相似文献
976.
977.
Liliana Chayet M. Cecilia Rojas Osvaldo CoriClifford A. Bunton Don C. McKenzie 《Bioorganic chemistry》1984,12(4):329-338
Kinetic analysis of the nonenzymic solvolysis of neryl and geranyl pyrophosphate (NPP and GPP, respectively) showed that the dissociation constants of the bis-metallic complexes with Mg2+ and Mn2+ were larger for NPP than for GPP by approximately one order of magnitude. Rate constants for reaction of the bis-metallic complexes were larger for NPP than for GPP. Qualitatively similar behavior was observed with complexes of Co2+. Extents of elimination and cyclization were increased by metal ions. Carbocyclase-catalyzed formation of cyclic monoterpene hydrocarbons in the presence of Mg2+ involved bis-metallic complexes as the “true” substrates. 相似文献
978.
Cecilia Schelin Håkan Wallin James Halpert Bengt Jergil 《Chemico-biological interactions》1984,49(3):269-281
A reconstituted mixed-function oxidase system, containing the major β-naphthoflavone-induced isozyme of rat liver cytochrome P-450 bound benzo[a]pyrene covalently in the presence of NADPH. NADPH-cytochrome P-450 reductase was required for binding and a maximum rate of adduct formation was obtained at 8 units of reductase per nmol cytochrome P-450. Phosphatidylcholine inhibited this reaction. Benzo[a]pyrene was bound to the cytochrome, but not to the reductase, as shown by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Approximately 6 molecules of benzo[a]pyrene bound to each molecule cytochrome P-450 during prolonged incubations. No binding occurred when the β-naphthoflavone-induced isozyme of cytochrome P-450 was replaced by the major isozyme induced by phenobarbital, but both cytochromes incorporated benzo[a]pyrene to approximately the same extent when they were incubated together in the presence of the reductase and NADPH. Metabolically activated benzo[a]pyrene also bound covalently to purified epoxide hydrodrolase, when this enzyme was added to the reconstituted mixed-function oxidase system. 相似文献
979.
Cecilia Gotti Donatella Cabrini Emanuele Sher Prof. Francesco Clementi 《Cell biology and toxicology》1987,3(4):431-440
Neurotoxicity of long-term exposure to lead, aluminum and cadmium has been studied in vitro on the human neuroblastoma cell line IMR32 by measuring cytotoxicity, and the effects on neuronal-specific characteristics such as nitrite outgrowth and expression of cholinergic receptors as parameters of toxicity. Cytotoxicity was highest with cadmium, intermediate with lead and lowest with aluminum exposure. Lead, but not cadmium and aluminum, interfered with neurite growth. The expression of a-bungarotoxin binding sites and muscarinic receptors was markedly increased by cadmium and not affected by aluminum exposure. Lead induced only an increase of toxin binding sites. These in vitro modifications are discussed in relation to the possible use of neuronal cell lines for detecting neurotoxic effects of heavy metals.Abbreviations ACh
acetylcholine
- -Bgtx
-bungarotoxin
- BrdUr
5'-bromodeoxyuridine
- CNS
central nervous system 相似文献
980.
Anna Carmen Borrione Anna Maria Cecilia Zanellato Leopoldo Saggin Manuela Mazzoli Giuseppe Azzarello Saverio Sartore 《Differentiation; research in biological diversity》1988,38(1):49-59
Myosin heavy chain (MHC) composition of chemically-induced rhabdomyosarcoma (RMS) was analyzed by gel electrophoresis and Western blotting using a panel of monoclonal antimyosin antibodies specific for embryonic-, neonatal-, slow- and adult fast-type MHC isoforms. Myosin extracted from tumours and electrophoresed on 6%-sodium dodecyl sulfate (SDS)glycerol gels was found to migrate as three distinct MHC components. These polypeptides were present in different relative amounts in the five RMS studied. Western blotting experiments revealed that variable proportions of embryonic-, slow- and adult fast-, but not neonatal-type, MHC isoforms are consistently expressed in RMS. Indirect and double immunofluorescence procedures applied to cryosections of tumoral tissue showed that: (a) RMS cells were unreactive with antineonatal-type-MHC antibody, (b) the majority of neoplastic, desmin-positive, cells contained embryonic- as well as adult fast-type MHCs and (c) a minority of cells were labelled by anti-slow MHC antibody. The results of this study indicate that there is no obligatory sequence of MHC isoform expression in the molecular transition (emb----neo----adult) which occurs during rat skeletal myogenesis. 相似文献