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Biomedical subjects

M Fukuda

Publications and source records attributed to M Fukuda.

At least 1,297 records · Page 72Linked to original sources
PubMed1983

Gastric mucosal blood distribution and its changes in the healing process of gastric ulcer.

Changes in gastric mucosal blood volume in the healing process of ulcers were investigated by organ reflectance spectrophotometry performed during endoscopy. Spectra were taken from 24 regions in the stomach in 42 patients with gastric ulcers located at the angle of the stomach. Fifty-one patients with no gastric lesions were used as normal controls. In patients with active gastric ulcers, mucosal blood volume decreased significantly in most regions in the stomach. During the healing process, mucosal blood volume returned to the same levels as those of the controls. On the other hand, mucosal blood volume around the gastric ulcer increased significantly as compared with that of surrounding mucosal at the healing stage. The rise in mucosal blood volume of the ulcer margin at the healing stage (H2 stage) was 33% in cases where gastric ulcers healed within 3 mo, and 2% in cases where the gastric ulcer failed to heal after 3 mo of therapy. It was concluded that the mucosal blood volume changes during the healing process of gastric ulcer and that an increased blood supply to the ulcer margin at the healing stage has a strong effect on the healing periods of ulcer. The reduction of mucosal blood volume at the active stage of the ulcer may also be implicated in the pathogenesis of gastric ulcers.

Adult↗
PubMed1983

Cytogenetic effects of argon laser irradiation on Chinese hamster cells.

The cytogenetic effects of argon laser light on V79 Chinese hamster cells were studied. Irradiation with a defocused continuous beam from an argon laser at doses of 100 to 400 J/cm2 had dose-related cytostatic and cytocidal effects. Cell cycle analysis by flow cytofluorometric measurement indicated that argon laser irradiation induced a temporary block at the G2 + M phase. The survival curve after laser irradiation was exponential without an initial shoulder and the D0 value (34% lethal dose) was calculated as 170 J/cm2. A significant increase in sister chromatid exchange was observed after laser irradiation. Laser irradiation also induced chromatid and chromosome aberrations, most of which were breaks and gaps. These chromosomal changes are probably not an artifact of the experimental procedures such as the use of phenol red and antibiotics or spontaneously emitted uv light. No mutation at the Na+/K+-dependent ATPase locus was induced by argon laser irradiation. Although the mechanism by which an argon laser beam induces cytogenetic damage remains to be investigated, the possible involvement of hyperthermia seemed to be excluded.

Animals↗
PubMed1982

Carbohydrate structure of hamster plasma fibronectin. Evidence for chemical diversity between cellular and plasma fibronectins.

The structure of the carbohydrate moiety of hamster plasma fibronectin was determined. The glycopeptides and oligosaccharides released by hydrazinolysis (Fukuda, M., Kondo, T., and Osawa, T. (1976) J. Biochem. (Tokyo) 80, 1223-1232) were analyzed by methylation and exoglycosidase digestion and the major oligosaccharide unit of hamster plasma fibronectin was shown to be (formula, see text) The structure of carbohydrate moiety of plasma fibronectin shown above (NeuGly, N-glycolyl-neuraminic acid) and that of cellular fibronectin (Fukuda, M., and Hakomori, S. (1979) J. Biol. Chem. 254, 5451-5457) are distinctly different with respect to the linkage of sialic acid, the degree of sialylation and the absence or presence of fucose. These results, therefore, provide the evidence for chemical diversity between cellular (fibroblast) and plasma fibronectins.

Animals↗
PubMed1982

Pressure dependence of trypsin-catalyzed hydrolyses of specific substrates.

The effects of pressure on the trypsin-catalyzed hydrolyzed hydrolyses of three specific substrates, N-benzoyl-L-arginine ethyl ester (BzArgOEt), amide (BzArgNH2) and p-nitroanilide (BzArgNA), have been examined. The volume of the activation (delta V++) for kcat was -2.4 ml/mol for BzArgOEt and +3 - +6 ml/mol for BzArgNH2. Because of different rate-determining steps in the steady-state kinetics, the delta V++ value for BzArgOEt would indicate the activation volume of the deacylation step, whereas that for BzArgNH2 the delta V++ for the acylation step. The activation volumes were accounted for in terms of the difference in the mechanisms on the formation and decomposition of the tetrahedral-like intermediates during the acylation and deacylation steps. The delta V values for the formation of BzArgNH2- and thionine-trypsin complexes were several ml/mol, consistent with the fact that the main driving force of the substrate binding to this enzyme is electrostatic interaction, and in contrast to the delta V values of alpha-chymotrypsin complex formation with indole (approximately 0 ml/mol) or 2-furylacryloyl-D-tryptophan methyl ester (approximately 0 ml/mol), for which the hydrophobic interaction is the dominant force of the substrate binding. For the hydrolysis of BzArgNA, which showed a distinct substrate activation at high substrate concentrations, the pressure dependence of the four parameters, ks, Ks, (the catalytic rate and dissociation constant of the normal enzyme-substrate complex, respectively), Kss and Kss (those of the complex activated by the binding of the second substrate molecule), were measured at 1 atm and 1000 atm (25 degrees C). All of the four parameters increased with increase in pressure.

Amides↗
PubMed1982

Two types of substance P-containing cells and their uneven distribution in the chicken retina: an immunohistochemical analysis with flat-mounts.

Substance P-like immunoreactivity (SPI) was investigated in the chicken retina by means of the indirect immunofluorescence method with flat-mounts. SPI cells were located mostly in the peripheral retinal regions, while in the central region, none or only a few cells were seen. Based upon their 3-dimensional profiles, SPI cells can be divided into two types: one type belongs to the stratified amacrine cells of the first sublayer and the other to those of the third to fifth sublayer.

Animals↗
PubMed1982

Glucoresponsive neurons in rat ventromedial hypothalamic tissue slices in vitro.

Extracellular action potentials were recorded from rat ventromedial hypothalamic nucleus (VMH) tissue slices in vitro. The identified glucoresponsive and non-glucoresponsive neurons were then visually located and observed by intracellular horseradish peroxidase staining. Glucoresponsive neurons, which were predominantly multipolar, were found near the center of the VMH, while non-glucoresponsive neurons, half of which were bipolar and half multipolar, were found randomly throughout the VMH.

Animals↗
PubMed1982

A fluorescence cytophotometer operated under computer control for multi-parameter cell analysis.

A new type of fluorescence cytophotometer has been developed for multi-parameter cell analysis (Olympus BH2-QRFL). For multi-color fluorescence cytophotometry, this instrument is equipped with four sets of interchangeable filters, each consisting of an excitation filter, a dichroic mirror with a barrier filter, and a measuring filter. For permitting automatic operation of the filter sets, the cytophotometer is connected on line with a personal computer (HP 85F). A desired sequence of filter sets can be memorized in the software and multiple cellular constituents can be rapidly and consecutively determined on a single cell basis. All data are stored in the same computer and can be retrieved for further statistical analysis and display either in tabular form, or as histogram, correlation histograms, two-dimensional scatter plot, or two-dimensional frequency distribution histogram, on the CRT (cathode ray tube) with simultaneous hard copy. As an example of multiparameter cell analysis, combined protein and DNA measurements were performed on normal, border-line, and cancerous gynecological cytology specimens by using the ninhydrin-Schiff and Feulgen techniques.

Cell Separation↗
PubMed1982

Mechanism of tobacco mosaic virus assembly: role of subunit and larger aggregate protein.

Tobacco mosaic virus (TMV) was reconstituted from the RNA of a common strain (OM) and the protein of a watermelon strain of cucumber green mottle mosaic virus (CGMMV-W), which is a member of the tobamovirus group. In 0.25 M phosphate buffer at 25 degrees C, CGMMV-W protein existed mainly as 21S aggregates. When this protein was mixed with OM RNA, complexes of short rods were formed but further elongation did not occur. After the addition of subunits in 0.1 M phosphate buffer at 25 degrees C, elongation to the 5' end of the RNA proceeded as fast as in the case of reconstitution with the usual equilibrium "disk preparation" of OM protein, to give 260-nm intermediates in the first 5-7 min. The results proved that the rapid elongation we previously observed in the reconstitution of TMV-OM following the assembly initiation is the outcome of preferential incorporation of TMV subunit protein. Either preformed 21S aggregate or the subunit of CGMMV protein was added to the 260-nm intermediate. Elongation to the 3' end of the RNA was investigated in 0.1 M phosphate buffer at 25 degrees C by measuring the distribution of rod length and the RNase-resistant infectivity. The results showed that the 21S aggregate is kinetically favored as the protein source during the slow elongation process.

Kinetics↗
PubMed1982

P 50 in burn injury.

P50, 2,3-diphosphoglycerate (DPG), inorganic phosphorus (Pi), adenosine triphosphate (ATP), and blood gases were measured daily in 23 patients with burn injuries, until their death or discharge from the ICU. At the time of admission, P50 values were high. In nonsurvivors, P50 started to decline 1 week after the injury. Corrected P50 values to pH 7.4 were well correlated with DPG values. In survivors, P50 tended to correlated with Pi values, but in nonsurvivors at the septic or terminal stage, the values P50 did not correlate with Pi or ATP. Low P50 predicted the poor outcome of severely burned patients. At the convalescent stage of major burn injury, P50 and DPG were higher than normal and often remained elevated for weeks.

2,3-Diphosphoglycerate↗