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Biomedical subjects

A Fukuda

Publications and source records attributed to A Fukuda.

At least 217 records · Page 12Linked to original sources
PubMed1983

Temperature-dependent growth restriction in measles vaccine strains.

Temperature-dependent growth restriction was studied with the measles vaccine strains licensed in Japan in comparison with their parental wild strains. Plaquing efficiency was compared at various temperatures from 35 to 40 C. AIK-C strain derived from Edmonston wild strain was temperature-sensitive with the 39 C shutoff temperature. No significant restriction of growth was found for other vaccine strains, i.e., Schwarz, FF-8, and CAM-70, and for their parental wild strains, i.e., Edmonston and Tanabe . A paradoxical feature was found for FF-8 strain; in spite of undiminished plaquing efficiency at 40 C, the growth in the fluid medium was markedly depressed at 39 C or above.

Measles Vaccine↗
PubMed1983

Effects of phenytoin on regional cerebral blood flow, electroencephalogram, and electrolyte contents in cerebral blood and cerebral cortex following total cerebral ischemia in dogs.

To study the protective effect of phenytoin on postischemic brain damage, total cerebral ischemia was produced for 8-12 min (aortic occlusion balloon catheter method) in 36 adult mongrel dogs. The regional cerebral blood flow (rCBF), sodium:potassium ratio in the cerebral cortex, electroencephalogram (EEG), and plasma electrolytes in the superior sagittal sinus blood were examined before ischemia and during the acute stage up to 120 min after recirculation in the control and phenytoin-treated groups. Measurement of rCBF (microsphere method) indicated easing of postischemic hypoperfusion of the cerebral cortex. The time from total cerebral ischemia to EEG electrical silence was significantly prolonged, and recovery of the electrical activity after recirculation was hastened. The increase in plasma potassium concentration in the superior sagittal sinus tended to be suppressed immediately after recirculation, and the sodium:potassium ratio in the cerebral cortex was lowered. Phenytoin increased the rCBF in the cerebral cortex, hastened the recovery of electrical activity, and stabilized the water and electrolyte balance in the cerebral cortex, suggesting some protecting effect on total cerebral ischemia.

Animals↗
PubMed1982

[Correlation between coagulation and fibrinolysis in patient with cerebrovascular accident at acute stage].

Ninety five patients with cerebrovascular accidents were studied on their coagulation and fibrinolysis at acute stage of their onset. From the data collected in the present study, following findings were obtained; 1) Hypercoagulable state, which are responsible for the decreased antithrombin III levels, was observed at acute stage of cerebral infarction. 2) Findings from patients with cerebral hemorrhage were normal antithrombin III levels and slightly decreased alpha 2-plasmin inhibitor. These imply the fact of increased fibrinolytic activities. It is suggested that increased fibrinolysis are secondary reaction of cerebral hemorrhage. 3) Findings from patients with subarachnoid hemorrhage showed hypercoagulable state and increased fibrinolytic activities. It is considered that subarachnoid hemorrhage might have mostly a preparatory condition of disseminated intravascular coagulation among cerebrovascular accidents.

Acute Disease↗
PubMed1981

Stopping powers of a tissue-equivalent gas for 40-200 ke V He+ and N+.

The stopping powers of a tissue-equivalent gas have been measured for He+ and N+ using the ion beams from a Cockcroft and Walton type accelerator and a differentially pumped gas cell. The stopping powers of each component of the tissue-equivalent gas were also measured and used to calculate expected values of the stopping powers of the tissue-equivalent gas. Results from direct measurement and from calculation showed good agreement.

Gases↗
PubMed1981

Regulation of polar morphogenesis in Caulobacter crescentus.

Deoxyribonucleic acid (DNA) phage phi CbK-resistant nonmotile mutants of Caulobacter crescentus CB15 were examined for their formation of polar surface structures (a stalk, a single flagellum, pili, and DNA phage receptors). These mutants were devoid of pili and DNA phage receptors and simultaneously defective either in both stalk formation and flagellar activity (stalk-defective type) or in the formation of normal flagella (flagella-defective type). DNA phage phi Cr30-mediated transductions revealed that stalk-defective mutants were of a single genetic type, whereas flagella-defective mutants were grouped into two different genetic types, I and II. To investigate how membrane proteins change in the above morphology mutants, cell envelopes pulse-labeled with L-[35S]methionine were analyzed by two-dimensional gel electrophoresis. No gross change of membrane proteins was observed in the stalk-defective mutant CB15 pdr-803, except a 49,000-molecular-weight (49K) protein which was found reduced. However, a 27K, two 28.5K, and a 70.5K protein were missing from the membrane of the flagella-defective type I mutant CB15 pdr-813. These proteins are most likely to be flagella-related protein, flagellins A and B, and hook protein, respectively. In another flagella-defective type II mutant, CB15 pdr-816, the 27K and two 28.5K proteins were similarly absent but the 70.5K protein was consistently present in the membrane. The synthesis of flagellin was next assayed radioimmunologically in the above 35S-labeled mutants. Stalk-defective CB15 pdr-803 synthesized flagellin normally, compared to the wild-type strain. Flagellins A (26K) and B (28K) formed multiple spots in isoelectric focusing. A 29K protein was also detected in the flagellin-specific radioactivity from the cytoplasm. Flagella-defective type I CB15 pdr-813 synthesized flagellin only at a basal level. Thus transcription or translation of flagellin appeared to be repressed in this mutant. Another flagella-defective type II strain, CB15 pdr-816, however, synthesized flagellin at an apparently enhanced rate compared with the wild type. Flagellin synthesized in CB15 pdr-816 was flagellin A and a smaller 22K flagellin. Flagellin B was not synthesized in the mutant. It then follows that flagellin B is not a precursor of flagellin A and the 22K flagellin. Flagella-defective type II CB15 pdr-816, without flagellin B, formed a stub structure with a hook attached to one end instead of normal flagella. In the wild-type membrane, flagellin B was the major flagellin, whereas flagellin A was major in the cytoplasm and the flagellar filament. It is suggested from these results that flagellin B is important in the assembly of normal flagella.

Bacteria↗
PubMed1981

Comparison of autoimmunity induction with virulent and attenuated rinderpest virus in rabbits.

Two strains of rinderpest virus which differ each other in virulence to rabbits were compared in their capacity to produce autoantibodies and their effects on the function of the lymphoid system. The virulent L strain induced two autoantibodies, i.e., antinuclear antibody (ANA) and cold hemagglutinating antibody (HA), and suppressed lymphocyte response to phytohemagglutinin and to concanavalin A for at least 4 weeks after infection. The attenuated LA strain, on the other hand, failed to induce the autoantibodies except transient production of cold HA in few animals, although persistent production of virus-neutralizing antibody like that in L strain infection was observed. The suppression of lymphocyte responses to mitogens was limited to a period of 3--7 days after infection. Possible mechanism of the virus-induced autoimmunity was discussed in relation to the immunosuppressive effect of virus infection.

Animals↗
PubMed1980

Stopping powers of a tissue-equivalent gas for 40--200 keV protons.

The stopping powers of a tissue-equivalent gas were measured for protons using the proton beam from a Cockcroft and Walton type accelerator and a differentially pumped gas cell. The stopping powers of each component of the tissue-equivalent gas were also measured and used to calculate expected values of the stopping powers of the tissue-equivalent gas. Results from direct measurement and from calculation showed good agreement. The results of the measurements on the component gases were also used to calculate the stopping power of Rossi's gas.

Carbon Dioxide↗
PubMed1980

The penicillin-binding proteins of Caulobacter crescentus.

The proteins that specifically bind penicillin G were studied with Caulobacter crescentus. This organism possessed at least 5 penicillin-binding proteins (PBPs): PBP 1A (132 K), PBP 1Bs (98 K), PBP 2 (77 K), PBP 3 (64 K), and PBP 4 (50 K). As expected from the unique morphology, the C. crescentus PBPs were different from those of other sources in molecular weight and localization: C. crescentus did not possess PBPs of low molecular weight. PBP 4 was found only in the outer membrane, while the other PBPs were present mostly in the inner membrane.

Bacteria↗
PubMed1978

Rate of major protein synthesis during the cell cycle of Caulobacter crescentus.

The rate of major protein synthesis was examined during the synchronous differentiation of Caulobacter crescentus. Total cell proteins were pulse-labeled with [35S]methionine at different times in the swarmer cell cycle and analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis. The rates of synthesis of total cell proteins and of about one-half of the individual major proteins examined increased through G1 and S periods but remained nearly constant during G2 period. The rates of synthesis of the other half of the individual major proteins either increased continuously throughout the swarmer cell cycle or doubled during S period. One stage-specific protein was also detected in late S period. For most of the major proteins examined, the rate of synthesis in the swarmer cell was less than that in the stalked cell. It seemed that, before the onset of G2 period, the Caulobacter cell was already able to synthesize each major protein at the additive rate of the two progeny cells. Compared to the stability of cellular proteins, the functional degradation rate of mRNA coding for individual major proteins was rapid, with half-lives of 0.4 to 5.8 min. It thus seems that the rate of major protein synthesis mainly reflects the transcriptional control of gene expression.

Bacteria↗