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101.
PI phenotyping by separator isoelectric focusing (SIEF) was performed on a total of 1000 unrelated Japanese individuals from two different areas of Western Japan. The PI M1M4 subtype was observed together with the six common PI M subtypes. PI*M4 was confirmed to be present but rare in the Japanese. Several new PI variants were identified by comparison runs of each variant with previously reported genetic variants. The significance of treatment of serum with dithiothreitol (DTT) followed by iodacetic acid (IAC) in determination of PI variants is also described. 相似文献
102.
Renzo Hirayama Kazuto Sato Katsuiku Hirokawa Mei-Ping Chang Yoshio Mishima Takashi Makinodan 《Cancer immunology, immunotherapy : CII》1984,18(3):209-214
Summary An attempt has been made to determine (a) whether aging plays an important role in resistance against metastasis and (b) whether dithiothreitol, an effective in vitro mitogenic potentiator of splenic cells of young and old mice, can modulate the occurrence of pulmonary metastasis. B16-F10 melanoma cells were injected into the outer ear of young and old female C57BL/6 mice; and the growth of the primary tumor, the palpable size of the cervical lymph node, and the number of lung metastases were then determined at various intervals. The ear was amputated when the primary tumor reached 4 mm in mean diameter. The following results were obtained. (a) The growth rate of the primary tumor in young mice is comparable to that in old mice. (b) Enlargement of the cervical lymph node occurs earlier in old than in young mice. (c) Old mice are more vulnerable to pulmonary metastases, but small metastasized pulmonary colonies are more prominent in old than in young mice. (d) Dithiothreitol (100 g) injected every 2 days after the inoculation of tumor cells is effective in reducing the incidence of pulmonary metastases in old mice. 相似文献
103.
104.
Cells of Arthrobacter sp. that had been isolated from soil were used to study oxidation of some linear terpenes and squalene variants. The cells oxidized geraniol, nerol, and farnesol to the corresponding aldehydes, with partial conversion of the geometrical isomerism of the alpha,beta-double bond. The squalene variant, squalene-2,3-oxide, was cleaved to 9,10-epoxygeranylacetone and geranylacetone. Squalene-2,3-22,23-dioxide was cleaved to 9,10-epoxygeranylacetone. These products were optically active, and their stereochemistry and optical purity were determined. 相似文献
105.
André B. Borle Takashi Uchikawa Julius H. Anderson 《The Journal of membrane biology》1982,68(1):37-46
Summary Stimulations or inhibitions by various agents of45Ca efflux from prelabeled cells or tissues display distinct and reproducible profile patterns when the results are plotted against time as fractional efflux ratios (FER). FER is the fractional efflux of45Ca from stimulated cells divided by the fractional efflux from a control unstimulated group. These profile patterns fall into three categories: peak patterns, exponential patterns, and mixed patterns. Each category can be positive (stimulation) or negative (inhibition). The interpretation of these profiles is difficult because45Ca efflux depends on three variables: the rate of calcium transport out of the cell, the specific activity of the cell compartment from which the calcium originates, and the concentration of free calcium in this compartment. A computer model based on data obtained by kinetic analyses of45Ca desaturation curves and consisting of two distinct intracellular pools was designed to follow the concentration of the traced substance (40Ca), the tracer (45Ca), and the specific activity of each compartment before, during, and after the stimulation or the inhibition of calcium fluxes at various pool boundaries. The computer model can reproduce all the FER profiles obtained experimentally and bring information which may be helpful to the interpretation of this type of data. Some predictions of the model were tested experimentally, and the results support the views that a peak pattern may reflect a sustained change in calcium transport across the plasma membrane, that an exponential pattern arises from calcium mobilization from an internal subcellular pool, and that a mixed pattern may be caused by a simultaneous change in calcium fluxes at both compartment boundaries. 相似文献
106.
Antisymmetry of the amino acid code table in terms of codon degeneracy is pointed out, and it is related to a physico-chemical problem of codon-anticodon interaction energy. A strong negative correlation between molecular weight of an amino acid and its codon degeneracy is pointed out, and its implication to the origin of the amino acid code table is discussed. Finally, an earlier form of the amino acid code table is proposed. 相似文献
107.
Kozo Hayashi Kazuo Yamada Keiji Ohe Akima Miyoshi Takashi Kawasaki 《生物化学与生物物理学报:生物膜》1980,596(3):414-419
The effect of amytal on energy metabolism and acid secretion in an isolated gastric mucosa of the guinea-pig were studied. Determination of adenine nucleotides, creatine phosphate, pyruvate and lactate in the gastric mucosa showed that amytal depressed the levels of ATP, creatine phosphate and energy charge with elevation of the AMP and pyruvate levels. This treatment inhibited concomitantly acid secretion and active chloride transport detected by short circuit current. The addition of menadione with ascorbate to the medium in the presence of amytal partially restored ATP and energy charge levels and also induced a partial recovery of acid secretion and active chloride transport. These results suggest that ATP is a direct energy donor for acid secretion in the gastric mucosa of the guinea-pig. 相似文献
108.
There are two 3-hydroxyacyl-CoA dehydrogenase (EC 1.1.1.35) in rat liver, one in mitochondria (type I enzyme), and another in peroxisomes (type II enzyme). In a series of the studies on the properties and the physiological roles of fatty acid oxidation systems in both organelles, the two enzymes were purified and compared for their properties. The final preparations obtained were judged to be homogeneous based on the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and sedimentation velocity analysis. Type I enzyme was composed of two identical subunits of molecular weight of 32,000, whereas type II enzyme was a monomeric enzyme having a molecular weight of 70,000–77,000. These subunit structures were confirmed by the results of fluorescence studies. Both enzymes were different in amino acid compositions, especially in the contents of tryptophan and half-cystine. Antibodies against them formed single precipitin lines for the corresponding enzymes, but not for the others when subjected to an Ouchterlony double-diffusion test. The Km values of type II enzyme for various substrates were lower than those of type I enzyme except those for acetoacetyl-CoA. As for 3-hydroxyacyl-CoA substrates, both enzymes had lower Km's for longer-chain substrates. The V for the substrates of C4C10 were similar for each enzyme, though the value of type II enzyme for C10 substrate was rather lower. The results of fluorescence studies suggested that their dissociation constants for NADH were lower and those for NAD+ were higher at lower pH. Both enzymes were specific to l-form of 3-hydroxyacyl-CoA substrate. The optimal pH of the forward reaction of type I and type II enzymes was 9.6 and 9.8, and of the reverse reaction, 4.5 and 6.2, respectively. From these results they were concluded to be completely different enzymes. 相似文献
109.
Summary Effects of divalent cations on oscillations of membrane potentials (i.e., spontaneous repetitive hyperpolarizing responses) and on hyperpolarizing responses induced by electrical stimuli as well as on resting potentials were studied in large nondividing L cells. Deprivation of Ca2+ from the external medium inhibited these hyperpolarizing responses accompanying slight depolarization of the resting potential. Sr2+ or Mn2+ applied to the external medium in place of Ca2+ was able to substitute for Ca2+ in the generation of hyperpolarizing responses, while Mg2+, Ba2+ or La3+ suppressed hyperpolarizing responses. The addition of A23187 to the bathing medium or intracellular injection of Ca2+, Sr2+, Mn2+ or La3+ induced membrane hyperpolarization. When the external Ca2+, Sr2+ or Mn2+ concentration was increased, the resting potential also hyperpolarized, in a saturating manner. The amplitude of maximum hyperpolarization produced by high external Ca2+ was of the same order of magnitude as those of hyperpolarizing responses and was dependent on the external K+ concentration. In the light of these experimental observations, it was deduced that the K+ conductance increase associated with the hyperpolarizing excitation is the result of an increase in the intracellular concentration of free Ca2+ mainly derived from the external solution. 相似文献
110.
Nakajima Hiromitsu; Yokota Takao; Matsumoto Takashi; Noguchi Masao; Takahashi Nobutaka 《Plant & cell physiology》1979,20(8):1489-1499
Various autonomous cultured tobacco cells including crown gallwere examined for their contents of growth regulators by meansof Avena curvature test, cell-division induction test, and tobaccopith callus test. The crown gall cells derived from cv. Hicks produced auxin andcytokinin in the high levels of 300500 µg IAA equivalentsand 4080 µg kinetin equivalents per kg, respectively.The major auxin was identified as indole-3-acetic acid basedon mass spectrometry and gas chromatography. These cells alsoproduced methyl indole-3-acetate as a minor component. One ofthe cytokinins was identified as ribosyl-trans-zeatin by meansof both gas chromatography-mass spectrometry and high performanceliquid chromatography. Auxin and cytokinin activities were not detected in the followingthree suspension cultured tobacco cells: cells requiring neithercytokinin nor auxin derived from the callus of N. tabacum cv.Bright Yellow and cells requiring auxin but not cytokinin derivedfrom the calluses of cv. Bright Yellow and cv. Hicks. Theirauxin and cytokinin contents per kg were less than 1 µgIAA equivalent and less than 0.1 µg kinetin equivalent,respectively. The results obtained in this study indicate that enhanced hormonalcontent is not the only reason for autonomous growth. (Received August 16, 1979; ) 相似文献