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Biomedical subjects

H Honda

Publications and source records attributed to H Honda.

At least 451 records · Page 25Linked to original sources
PubMed1986

Directional movement of F-actin in vitro.

By a fluorescence microscopic method for visualizing single filaments of F-actin in solutions, we have investigated movement of F-actin in a motility system in vitro. It was found that, when F-actin and myosin were mixed in the presence of Mg2+-ATP under appropriate conditions, individual F-actin filaments continued moving in different directions, but in parallel to their length, for a long period of time. The actin filaments did not reverse their direction of movement and had a distribution of speed with the maximum at about 5 micron per second (at 27 degrees C).

Actins↗
PubMed1986

Gastric and intestinal phenotypic expressions of human signet ring cell carcinomas revealed by their biochemistry, mucin histochemistry, and ultrastructure.

Gastric and intestinal phenotypic expression in 37 surgically obtained primary signet ring cell carcinomas, five of their metastases to lymph nodes, and three signet ring cell carcinomas transplanted into nude mice were determined by biochemical, mucin, histochemical, and ultrastructural studies. Crude extracts of cancer tissues were used for measurements of pepsinogen isozymes, sucrase, aminopeptidase (microsomal), and alkaline phosphatase. Histochemical staining of mucin by paradoxical concanavalin A, the galactose oxidase-Schiff sequence and sialidase-galactose oxidase-Schiff, and the periodate-borohydride technique/potassium hydroxide/periodic acid-Schiff procedure was performed. The procedures allowed clear definition of pyloric gland, surface mucous, small and large intestinal goblet, and intestinal absorptive cell types. Of 40 specimens examined, 19 consisted entirely of gastric-type cells, and three entirely of intestinal-type cells. The others consisted of mixtures of gastric and intestinal-type cells. The observed high incidence of intestinal-type cells in signet ring cell carcinomas suggested that intestinal-type cells develop independently from intestinal metaplasia within signet ring cell carcinomas (diffuse-type gastric cancers), which probably originate from nonmetaplastic gastric mucosa.

Adenocarcinoma, Mucinous↗
PubMed1986

[Combination of selective intra-arterial infusion of an anticancer agent via the vascular access port with RF local hyperthermia].

It is desirable for multidisciplinary cancer treatments to be concentrated as selectively as possible onto the cancer-bearing organs in order to augment the anticancer effects and minimize the untoward effects. Combined treatments of selective intraarterial infusion of anticancer agents via an implanted Vascular Access Port with local hyperthermia using 13.56 MHz RF have been performed in 12 patients with extensive cancers. In 9 out of these 12 cases (75%), more than 50% reduction in tumor size has been obtained. Tumor-diminishing effect was more remarkable in patients who underwent bolus infusion of anticancer agents such as 1 mg/kg of mitomycin C under charcoal hemoperfusion for rapid removal of anticancer agents from the blood stream.

Aged↗
PubMed1986

Diagnosis of diffuse hepatocellular diseases using SPECT.

In the scintigraphic diagnosis of diffuse hepatocellular diseases, increased splenic uptake of colloids and splenomegaly are helpful signs. To quantify these patterns, the volume and activity of liver and spleen were measured by using single photon emission computed tomography (SPECT). The spleen-to-liver (S/L) ratios in volume and activity that were calculated from SPECT images were estimated in normal individuals and in patients with diffuse hepatocellular diseases. The maximum normal limits of S/L ratios of volume, activity, and activity/volume were predicted as 0.19, 0.087, and 0.72 (mean +/- 2 s.d.). Twenty-two of twenty-three patients (96%) with liver cirrhosis had at least two elevated S/L ratios, and three elevated S/L ratios could clearly differentiate the patient with liver cirrhosis from normal individuals. On the other hand, only six patients (32%) with chronic hepatitis had elevation of any S/L ratio. Abnormal S/L ratios of activity/volume in the range from 0.72 to 1.05 were not obvious on planar or SPECT images.

Chronic Disease↗
PubMed1986

Transformation of a polygonal cellular pattern during sexual maturation of the avian oviduct epithelium: computer simulation.

A peculiar cellular pattern resembling a checkerboard has been observed on the luminal surface of the oviduct epithelium of an adult Japanese quail. The epithelium is a monolayer cell sheet and consists of two types of columnar cells, ciliated cells (C-cells) and gland cells (G-cells) assembled in alternating blocks. The pattern develops, during sexual maturation, from a kagome-like pattern (in which large C-cells are surrounded by small G-cells) characteristic of the immature oviduct. In the present paper, computer simulations of the pattern transformation from kagome to checkerboard were performed assuming a few properties of individual cells. The adult checkerboard-like pattern is not strictly rectangular, but is deformed toward a honeycomb pattern. In theoretical considerations the assumption that adhesion is stronger between unlike cells than between like cells formed an ideal checkerboard pattern, because all cell boundaries in it are edges along which unlike cells meet. On the other hand, a honeycomb pattern formed after assuming that the boundary length of the cellular pattern is minimized (caused by contraction of bundles of microfilaments running along lateral boundaries of the columnar epithelial cell while keeping contact between neighbouring cells). The actual checkerboard-like pattern was considered to be in a balanced state between the effects of (1) the strong adhesion between unlike cells, and (2) the boundary contraction. Using a computational analysis, this consideration enabled us to obtain a quantitative parameter value for the difference between cell adhesions of unlike cells and of like cells. C-cells divided once during the kagome-checkerboard transformation, while G-cells did not divide. We performed computer simulations starting with the kagome pattern in which all C-cells divided once. The computer program of the boundary shortening procedure we used involved the quantitative parameter value for differential cell adhesion obtained as described above. A checkerboard pattern was successfully generated in the simulation. It is concluded that the strong adhesion between unlike cells and the boundary shortening have important roles in formation and maintenance of the kagome and checkerboard patterns of the avian oviduct epithelium.

Animals↗
PubMed1986

Similarities between rat liver mitochondrial and cytosolic glutathione reductases and their apoenzyme accumulation in riboflavin deficiency.

Glutathione reductase has been purified 5,500-fold from rat liver mitochondrial matrix in a yield of 30%. The mitochondrial enzyme was immunochemically indistinguishable from that of the cytosol and the subunit molecular weight was apparently similar to that of the cytosolic enzyme, that is, 50,000 daltons. The optimum pH and kinetic properties investigated were not significantly different from those of the cytosolic enzyme. When rats were fed a riboflavin-deficient diet, the enzyme activity in the mitochondria decreased to a greater extent than that in the cytosol, and greater accumulation of apo-enzyme in the former than that in the latter was confirmed by the amount of immunoprecipitable protein, activation by FAD addition in vitro, and the enzyme activity recovery after injection of riboflavin, into riboflavin-deficient rats.

Animals↗
PubMed1986

A new expression of pharmacological activity, ET63.

We studied the response time of drugs in relation to the feedback mechanism in animals. The time from drug administration to onset of loss and recovery of righting reflex or death by hexobarbital in mice were measured at several dose levels and it was demonstrate that in every case the time (t)- response rate (R) function could be expressed as: (formula: see text) These parameters could be obtain by use of only a small number of animals at every dose level. The result suggests that the pharmacological activity of not only pure drugs but also of commercial chemicals with fixed standard of purity and concentrations may be expressed by the parameter t63 transposed as ET63. t63: time when cummulative response rate reaches 63%. t1: latency.

Animals↗
PubMed1985

Effect of cyclic AMP and cyclic GMP on the autophosphorylation of elongation factor 1 from wheat embryos.

Extensively purified EF-1H (EF-1 alpha beta beta' gamma) from wheat embryos had a protein kinase activity and phosphorylated EF-1 beta which is one of the two EF-Ts-like factors (EF-1 beta and EF-1 beta'). In this reaction ATP and GTP were equally effective as phosphate donors, and threonine residue was phosphorylated. At 10(-7)M, 3', 5' cyclic GMP stimulated both the phosphorylation and phe-tRNA binding reactions, whereas 3', 5' cyclic AMP inhibited both reactions. These findings indicate that phosphorylation of EF-1H may play an important role in the translational control of protein biosynthesis at the elongation step.

Autoradiography↗
PubMed1985

[Pharmacological actions of iprazochrome on the vascular system].

The pharmacological actions of iprazochrome (IC) on the vascular system were studied, and the following results were obtained: No death nor abnormal behaviors were observed in acute toxicity tests conducted on male and female mice and rats despite the administration of large doses of IC (10,000 mg/kg, p.o. and 80 mg/kg, i.v., respectively). IC inhibited dose-dependently platelet aggregation in vitro induced by arachidonate and ADP, whereas no effect was observed on ADP-induced respiratory depression in mice, which is closely related to platelet aggregation in vivo. The antiserotonergic actions of IC on the isolated external carotid arteries and femoral arteries in dogs observed in a noncompetitive manner were found to be 1/24 to 1/65 that of methysergide. On the other hand, IC showed no inhibitory effect on the paw edema of rats in vivo induced by serotonin. The inhibitory effect of IC on peritoneal dye leakage in mice was less than half that of phenylbutazone. IC prevented apoplexy in stroke-prone SHR (SHRSP) without lowering the blood pressure. Histological changes in the cerebrum of SHRSP were ischemic changes such as swelling of the neurons and shrinkage of the nuclei, mainly in the cerebral cortex and corpus striatum area.

Adrenochrome↗
PubMed1985

Electrophysiological analysis of warming up phenomenon in myotonia.

The after discharges following grip and percussion in myotonia of 4 cases with myotonic dystrophy were evaluated in repetitive percussion or grip, in cold exposure and in warm exposure electromyographically. By repetition, the after discharges reduced markedly. After 2 or 3 trials, after discharges disappeared or became short duration. During local cooling (15 degrees C-20 degrees C), the amplitude and the prolongation in the duration of after discharges were marked, although these enhanced after discharges were reduced by repetition even in cooling. During local warming (40 degrees C-42 degrees C), the after discharges became less marked or disappeared. Both the warming of muscle and the repetitive movements reduced the duration of abnormal after discharges. These effect might be explained on the same mechanism which was the change of the ion transport in muscle membrane, and could be called as warming up phenomenon together. The degree of these after discharges are close related to the degree of myotonic phenomenon. Myotonia is the disorder of primarily the electrical excitabilities, not the contractile properties. So the method of evaluation of after discharges electromyographically is very valuable compared to the measurement of the relaxation process which was used popular in evaluation of myotonia in the past.

Action Potentials↗