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931.
932.
933.
Methanobacterium thermoautotrophicum, an archaebacterium, possesses the first and last enzymes of the diaminopimelic acid pathway for lysine biosynthesis, dihydrodipicolinate synthase, and diaminopimelate decarboxylase. It does not have saccharopine dehydrogenase, the last enzyme of the aminoadipate pathway for lysine biosynthesis. The dihydrodipicolinate synthase is inhibited but not repressed by lysine. We conclude that this microbe uses the diaminopimelate pathway for synthesis of lysine.Deceased.  相似文献   
934.
Addition of a thermostable cytoplasmic fraction leads to the uncoupling of oxidative phosphorylation of the mitochondria. In hyperthyrosis such an effect manifests itself more powerfully than in the control. Addition of the thermostable cytoplasmic fraction induces electrogenic phosphate transport via the mitochondrial membrane. In hyperthyrosis, the activity of the thermostable inducer of phosphate transport in the cytoplasm increases. The functioning of the phosphate cycle may be the cause of the uncoupling of oxidative phosphorylation of the mitochondria during the disease in question.  相似文献   
935.
936.
Additive reagents have been investigated to improve the stability of methanolic Wright's stain. The addition of ammonium halides, monoalkyiamine hydrochlorides, dialkylamine hydrochlorides or trialkylamine hydrochlorides to methanolic Wright's stain was found to enhance the stability of stain components in methanol. No change in performance is observed with these additives present. Random precipitation in the stain solution was still observed with the addition of ammonium halides and monoalkyiamine hydrochlorides. No precipitation was found in stain solutions containing hydrochlorides of most dialkylamines and trialkylamines. Of the compounds evaluated, 0.6% diethylamine hydrochloride added to methanolic stain solutions produced the most desirable overall results. Mechanisms of stabilization and precipitation in these stain solutions are proposed, Essentially, separation of the thiazine-eosinate ion pair through interaction with an appropriate additive increases stain stability. The solubilities of thiazine-eosinate or additive cation-eosinate ion pairs in methanol determine the formation of precipitate in such stain solutions.  相似文献   
937.
Two general models for the transspecific evolution of butterfly colour patterns are advanced: directional selection acting equally on both sexes, and disruptive selection involving periods of polymorphism. To consider possible outcomes of me latter process, a morphism notation based on an integrated classification for polymorphism and sexual dimorphism is developed. This notation is used to examine the properties of all morphism transformations possible from the minimal expressions of the nine morphism categories, as reached through defined minimum step changes. The significance of such pathway models is analysed in terms of general properties of butterfly polymorphism. The potential use of pathway models in evolutionary studies is briefly discussed, mainly with respect to phylogenetics, and ideas on the evolution of genetic dominance.  相似文献   
938.
939.
S Mikamo 《Human cell》1992,5(3):256-266
Inflammatory cytokines are able to facilitate the homing of transferred lymphocytes, tumor cell lysis through induction of adhesion molecules, also able to reduce tumor cell susceptibility to LAK cells by increasing tumor cell class I antigen. Investigation with 12 cell lines suggested that promotion of lysis by ICAM-1 was more responsible than protection by (allogeneic) class I Ags (Fig. 1). PBMC were cultured in anti-CD3 coated flasks with rIL-2. CD3+ cells dominated until day 7, decreased thereafter with CD4+. CD8+ and CD16+ increased (Fig. 2). Strong cytotoxicity obtained in some cultures correlated well with CD16+, contributing exclusively among several variables to the activity estimation in multiple regression analysis (Fig. 4). Among 6 cases, in which 2 or more cycles of transfer was done, 1 was prophylaxis of recurrence, in 2 of 3 advanced metastasis cases in which cells were transferred as BRM in the course of chemotherapy, survival of half a year was obtained in good QOL with suppressed disease and adequate level of PBL number. In 2 other cases, inflammation eliciting local treatments were combined. In the case 4, three large liver metastasis from colon cancer which resisted topical ethanol injection and chemotherapy, responded to the transfer with reduced lesions to 1/8 (Fig. 8). In the case 5, abdominal metastasis from colon cancer were removed, liver metastasis were injected of ethanol, and cells were transferred. Responses were obtained to immunotherapy in a certain degree, while never to any chemotherapy.  相似文献   
940.
G M?rdh  D S Auld  B L Vallee 《Biochemistry》1987,26(24):7585-7588
Thyroid hormones are potent, instantaneous, and reversible inhibitors of ethanol oxidation catalyzed by isozymes of class I and II human alcohol dehydrogenase (ADH). None of the thyroid hormones inhibits class III ADH. At pH 7.40 the apparent Ki values vary between 55 and 110 microM for triiodothyronine, 35 and greater than 200 microM for thyroxine, and 10 and 23 microM for triiodothyroacetic acid. The inhibition is of a mixed type toward both NAD+ and ethanol. The binding of the thyroid hormone triiodothyronine to beta 1 gamma 1 ADH is mutually exclusive with 1,10-phenanthroline, 4-methylpyrazole, and testosterone, identifying a binding site(s) for the thyroid hormones, which overlap(s) both the 1,10-phenanthroline site near the active site zinc atom and the testosterone binding site, the latter being a regulatory site on the gamma-subunit-containing isozymes and distinct from their catalytic site. The inhibition by thyroid hormones may have implications for regulation of ADH catalysis of ethanol and alcohols in the intermediary metabolism of dopamine, norepinephrine, and serotonin and in steroid metabolism. In concert with other hormonal regulators, e.g., testosterone, the rate of ADH catalysis is capable of being fine tuned in accord with both substrate and modulator concentrations.  相似文献   
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