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81.
82.
Heat-stable somatic antigen (HSSA) variants were isolated from Bacillus thuringiensis strain T84A1-A by antiserum-mediated selection. Substantial differences in HSSAs were clearly shown between variants and the parent strain by HSSA agglutination tests, Ouchterlony tests and precipitin-halo-formation (PHF) tests of extracellular HSSAs, although a 'one way'cross-reaction was evident. The frequency of HSSA variants in the population was < 10-4 , as determined by PHF tests on antiserum-agar plates. Heat-stable somatic antigen variants showed no alteration in flagellar antigenic structure and in 30 phenotypic characteristics. The insecticidal activity of HSSA variants was on the level with that of the parent strain, when tested with larvae of three lepidopterous species. 相似文献
83.
Satoru Ohba Kiyoshi Kidouchi Toshiyuki Katoh 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1991,568(2)
A column-switching high-performance liquid chromatographic method, requiring no sample preparation apart from filtration, is described for quantification of urinary orotic acid, uracil and pseudouridine. The analyses were carried out using a reversed-phase octadecylsilane-bonded column for sample clean-up and a cation-exchange column for separation; 5–20 ]sml samples of urine were directly analysed, and more than 100 samples could be analysed consecutively. Each sample required only 30 min. Detection limits of these compounds were 5 pmol. Creatinine-related urinary uracil excretion was lowest in the newborn period (17.3 ± 14.4 μmol/g of creatinine). A patient with partial ornithine transcarbamylase deficiency and his mother usually excreted a high level of uracil during the period of normal orotic acid excretion and normal serum ammonia level. 相似文献
84.
Release of Excitatory Amino Acids from Cultured Hippocampal Astrocytes Induced by a Hypoxic-Hypoglycemic Stimulation 总被引:2,自引:0,他引:2
Tadanori Ogata† Yoichi Nakamura Taiho Shibata† Kiyoshi Kataoka 《Journal of neurochemistry》1992,58(5):1957-1959
An excess release of excitatory amino acids (EAA) is an important factor for postischemic brain damage. In the present communication, we demonstrate that cultured hippocampal cells release EAA after hypoxic-hypoglycemic treatment. The amounts of EAA released from astrocytes were appreciably above those released from neurons. Furthermore, the amount of aspartate released from astrocytes was comparable to that of glutamate, although the endogenous content of aspartate was one-fifth that of glutamate. The endogenous content of aspartate in astrocytes increased even after hypoxic-hypoglycemic treatment. These results suggests that ischemic neuronal death is due, at least in part, to the excitotoxicity of aspartate and glutamate derived from surrounding astrocytes. 相似文献
85.
H Aizawa M Kamijo Y Ohba A Mori K Okuhara H Kawasaki H Murofushi K Suzuki H Yasuda 《Biochemical and biophysical research communications》1991,179(3):1620-1626
Microtubule-associated protein-4 (MAP-4), a major MAP in proliferating cells, consists of a microtubule-binding domain and a projection domain protruding from the microtubule wall. The former contains a Pro-rich region and an assembly-promoting (AP) sequence region which is common to the neuron-specific MAPs, MAP-2 and tau1. In this paper, we describe the phosphorylation of the Pro-rich region of MAP-4 and the suppression of its assembly-promoting activity by cdc2/H1 histone kinase. This inactivation of MAP-4 may cause disassembly of the interphase microtubular network at the end of the G2 phase of the cell cycle. 相似文献
86.
87.
Kiyoshi Ohkawa Takashi Hatano Naoko Takizawa Kazue Shinmoto Kyosuke Yamada Makoto Matsuda Koji Takada Yutaka Tsukada 《In vitro cellular & developmental biology. Animal》1992,28(6):449-454
Summary A human yolk sac tumor cell line, TG1, which was established from a testicular yolk sac tumor, was found to replicate continuously
in a chemically defined medium supplemented with Na2SeO3 (ISRPMI). TG1 produced several plasma proteins and growth factors: albumin, alpha-fetoprotein (AFP), ferritin, carcinoembryonic
antigen, beta-2-microglobulin, polyamine, neuron specific enolase, tissue polypeptide antigen, transferrin (Tf), epidermal
growth factor, and platelet derived growth factor. By analysis of lectin (LcHA)-affinity electrophoresis, to examine the microheterogeneity
of carbohydrate chains of synthetic glycoproteins, TG1 cells cultured with ISRPMI produced only LcHA reactive Tf and AFP based
on core fucose attached to asparagine-linkedN-acetylglucosamine residues instead of LcHA-nonreactive Tf and AFP produced by TG1 cells cultured with fetal bovine serum
(FBS)-containing medium.α1-6 Fucosyltransferase activity was significantly greater in the TG1 cells cultured with ISRPMI (39.9±1.5 pmol · h−1 · mg−1 protein) than cultured with FBS-containing media (18.2±1.2 pmol · h−1 · mg−1 protein). These results have indicated that the selective increase ofα1-6 fucosyltransferase occurred when the cells were cultured with the FBS-free synthetic media. 相似文献
88.
89.
H Sotokawa T Shimizu H Furuya A J Sadeque M Hatano Y Ohba M Iwaizumi Y Fujii-Kuriyama 《Biochimica et biophysica acta》1990,1037(1):122-128
Low-temperature (6-40 K) electron spin resonance (ESR) spectra of cytochrome P-450d (P-450d) and its 17 mutants have been measured. The spectra of the wild-type and all mutant P-450ds showed signals at around g = 8, 3.7 and 1.7, while they didn't show any signal at around g = 2 up to 40 K. It was thus suggested that all of these P-450ds essentially take the ferric high-spin form. The g values of the proximal mutants were closer to those of the wild-type than those of the distal and aromatic mutants, suggesting that mutations at the distal and aromatic sites influence the electronic state of the heme more profoundly than those of the proximal site. The distal multiple mutants whose distal sequences are the same as those of the low-spin type P-450s such as rat P-450c, mouse P1-450 and P3-450 showed only high-spin ESR signals. Thus the spin state of P-450ds (the wild-type and all mutants) may not be solely due to specific characteristics of the distal site, but to the unique nature of the whole heme environment of P-450d. It is also suggested that the amino acids at the distal region of P-450d may be located close to the heme, so that the water molecule cannot bind to the heme, thus taking the high-spin state. Both the aromatic mutants showed rather large deviations of the g values from those of wild-type P-450d, suggesting that the aromatic region somehow interacts with the heme. 相似文献
90.
Summary Deficiency of inorganic phosphate caused the hyper production of invertase and the derepression of acid phosphatase in a continuous culture ofSaccharomyces carlsbergensis. The specific invertase activity was 40,000 enzyme units per g dry cell weight at a dilution rate lower than 0.05 h–1 with a synthetic glucose medium of which the molecular ratio of KH2PO4 to glucose was less than 0.006. This activity is eight fold higher than in a batch growth and 1.5 fold as much as the highest enzyme activity observed so far in a glucose-limited continuous culture.For the hyper production of invertase, it is necessary to culture the yeast continuously by keeping the Nyholm's conservative inorganic phosphate concentration at less than 0.2 m mole per g dry weight cell. The derepression of acid phosphatase brought about by phosphate deficiency, was similar in both batch and continuous cultures.Nomenclature D
dilution rate of continuous culture (h–1)
- Ei
invertase concentration in culture (enzyme unit l–1)
- Ep
acid phosphatase concentration in culture (enzyme unit l–1)
- P
inorganic phosphate concentration in culture (mM)
- S
glucose concentration in culture (mM)
- X
cell concentration in culture (g dry weight cell l–1)
Greek Letter
specific rate of growth (h–1)
Suffix f
feed
- 0
initial value 相似文献