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Biomedical subjects

H Kanazawa

Publications and source records attributed to H Kanazawa.

At least 253 records · Page 14Linked to original sources
PubMed1986

A successful electrical ablation of recurrent sustained ventricular tachycardia in a postoperative case of tetralogy of Fallot.

A 26 year old female patient developed recurrent sustained ventricular tachycardia (VT) after undergoing heart surgery for the third time for chronic pulmonary regurgitation following repair of tetralogy of Fallot. At the last surgery, ventriculotomy was again performed in the outflow tract of the right ventricle. At that time, scar formation and thinning of the cardiac wall were obvious. The surgical result was excellent. Three months later, she lost consciousness. ECG showed VT which was refractory to tolerated doses of antiarrhythmic drugs. Electrophysiologic study showed fragmented activity in the outflow tract of the right ventricle during VT which could be induced and terminated by programmed electrical stimulations. DC energy delivery of 200 Joules to catheter electrodes which recorded local activity 20 msec prior to the onset of the QRS of VT was successful in preventing VT. VT could not be induced by extensive programmed stimulation 1 month later.

Adult↗
PubMed1986

Microcirculation of the pancreas in the rat and rabbit with special reference to the insulo-acinar portal system and emissary vein of the islet.

Microcirculation of the pancreas in the rat and rabbit with special reference to the islets was studied by scanning electron microscopy (SEM) of vascular corrosion casts, light microscopy (LM) of India ink-injected/cleared tissues, and intravital microscopy of in situ organs. The following observations were made: Approximately 10-20% of the total terminal arterioles supplied the islets, while the remainder directly supplied the exocrine pancreas. The vas afferens of the islets divided into sinusoidal capillaries with frequent U-shaped turns in the cortical A and D cell area of the islets, and their secondary branches supplied the core B cell area. Intravital microscopy confirmed that blood irrigated the cortex of the islets first and the core portion second. All islets observed possessed insulo-acinar portal vessels. About 60% of the islets in the rat possessed emissary veins leading directly into the systemic circulation, while in the rabbit, less than 5% of islets possessed emissary venules of small diameter. Thus, the well-developed emissary veins of the islets seemed characteristic of the rat, as compared with the rabbit and several other mammals examined previously. The insulo-acinar portal system seems to represent a short vascular route through which islet secretions are transported in high concentrations to the exocrine pancreas, there to exert their actions. The emissary veins of the islet seem to serve for the quick conveyance of insular secretions into general circulation. It is suggested that the pancreatic lobule is made up of subdivisions or microcirculatory units, each of which is supplied centrally by the insulo-acinar portal system, while peripherally the unit also receives direct branches of intralobular arterioles. The veins run the periphery of the unit. The occurrence of sphincters in the vas afferens and the emissary veins of the islets is suggested as being involved in the regulation of the islet blood flow.

Animals↗
PubMed1986

[Treatment results of locally advanced carcinoma of the breast with radiation therapy].

Nineteen patients with stage IIIb carcinoma of the breast were radically treated with radiation therapy from November 1966 through November 1976 at the Aichi Cancer Center hospital. The actuarial three and five year survival rate were 42% and 32%, respectively. The prognosis of the patients received a total dose of more than 75 Gy was better than that of less than 75 Gy, although there was no statistical difference between two groups. All five cases with a inflammatory breast cancer died within 2 years from the beginning of radiotherapy. In the majority of the cases, the first relapse appeared within 2 years after treatment. Minor complications were observed in nine cases (47.4%), but no major complications.

Adult↗
PubMed1986

Plasma gastrin and secretin changes after esophagectomy.

Plasma gastrin levels were determined in 14 patients with esophageal cancer submitted to an esophagogastrectomy. Six patients were also given 0.1 N hydrochloric acid preoperatively and 1 month after operation to clarify the secretion of plasma secretin. In addition, the correlation between the G cell population in the pyloric part of the postoperative intrathoracic stomach and plasma gastrin was investigated, and the following results were obtained. Hypergastrinemia developed 1 month after surgery, but 3 months or more after surgery, the plasma gastrin level was close to normal. Plasma secretin levels tended to fall postoperatively, but no statistical differences in plasma secretin levels could be found. Staining by the enzyme antibody method revealed hyperplasia of G cells in patients with hypergastrinemia without pyloric antral atrophy.

Aged↗
PubMed1985

ATP synthesis and hydrolysis by a hybrid system reconstituted from the beta-subunit of Escherichia coli F1-ATPase and beta-less chromatophores of Rhodospirillum rubrum.

Photophosphorylation and ATPase activities were restored to beta-less Rhodospirillum rubrum chromatophores by their reconstitution with purified beta-subunits of either R. rubrum F1-ATPase (Rr beta) or Escherichia coli F1-ATPase (Ec beta). In the homologous reconstituted system both activities were restored to the same extent, whereas in the hybrid system ATP synthesis was restored to about 10% when the hydrolysis was restored to 200%. This difference in rates of synthesis and hydrolysis was not due to any general uncoupling effect of Ec beta leading to an increased membrane permeability to protons, because with both hybrid and homologous systems an identical light-induced quenching of quinacrine fluorescence was observed. They differed, however, in ATP-driven quenching of quinacrine fluorescence, which was much lower in the hybrid system. These results suggest that the hybrid has a decreased capacity for proton-translocation through the membrane-bound Fo channel during ATP hydrolysis, and probably also during ATP synthesis. The very high ATPase activity of the hybrid system indicates that it might enable the released protons to leak to the outside medium rather than to move inside through the Fo channel. The activities restored by Rr beta and Ec beta exhibit a similar sensitivity to dicyclohexylcarbodiimide, but different sensitivities to oligomycin and to an anti-E. coli F1 (EcF1) antibody. Oligomycin inhibited only the homologous R. rubrum system whereas anti-EcF1 was a much more effective inhibitor of the hybrid system. It is therefore concluded that Rr beta plays a role, that the Ec beta cannot fulfill, in conferring oligomycin sensitivity to the RrFo X F1-ATP synthase-ATPase complex.

Adenosine Triphosphate↗
PubMed1985

Relationship between the radiologic features of esophageal cancer and the local control by radiation therapy.

In order to predict the possibility of local control of esophageal cancer by radiation therapy, the relationship between the x-ray findings before and after irradiation and the histologic radiation effect obtained from the surgically resected esophagus was analyzed in 130 cases irradiated preoperatively during the period 1971 through 1980. In the superficial or proliferative type in x-ray image before treatment, the local control was obtained in 46.5% of the cases with the dose of 40 Gy, whereas in the ulcerative or infiltrative type, in 21.8%. The barium examination performed after irradiation was more useful to evaluate the radiation effect than that before treatment. In cases with a marked radiation effect after irradiation, the frequency of local control reached 76.9%. On the other hand, the local control remained 11.9% in cases with no or poor radiation effect. The results obtained by the preoperatively irradiated cases were applied to the analysis of 119 cases irradiated radically during the period 1965 to 1980. Almost the same results were also acquired in radically irradiated cases. The degree of radiologic and histologic radiation effect on the primary tumor was closely related to the long-term survival rate of the patient.

Adult↗
PubMed1985

Deletion of seven amino acid residues from the gamma subunit of Escherichia coli H+-ATPase causes total loss of F1 assembly on membranes.

A mutant gene for the gamma subunit of H+-translocating ATPase was cloned from Escherichia coli mutant NR70 isolated by B. P. Rosen [J. Bacteriol. 116, 1124-1129 (1973)]. Determination of its nucleotide sequence revealed a deletion of 21 base pairs between nucleotide residues 64 and 84, resulting in a deletion of seven amino acid residues (LysAlaMetGluMetValAla) from the amino-terminal portion. This deletion resulted in the loss of a hydrophobic domain of the subunit estimated by an analysis of its hydropathic character. Since F1 subunits are reported not to be assembled on the normal F0 portion of NR70, it is concluded that the hydrophobic domain deleted in the mutant subunit is important for assembly of the F1 portion. Introduction of a plasmid pNR70 carrying the mutant allele of NR70 into a wild-type strain gave no recombinants resistant to neomycin. This result suggested that the neomycin-resistant phenotype is not directly related to the defect in the gamma subunit of NR70.

Amino Acid Sequence↗
PubMed1985

Effects of ACNU, a water-soluble nitrosourea derivative, on survival and cell kinetics of cultured HeLa S3 cells.

Effects of a water-soluble nitrosourea, 1(4-aminomethylpyrimidine-5yl)methyl-3-(2-chloroethyl)-3-nit rosourea hydrochloride (ACNU) was investigated on cultured HeLa S3 cells with regard to their lethality and cell progression through the cell cycle. The survival curve of exponentially growing cells exposed to increasing concentrations of the drug for 1 hr was characterized by a threshold type of response (Do = 7.0 micrograms/ml X 1 hr, Dq 3.5 micrograms/ml X 1 hr). Throughout the cell cycle, ACNU exerted its main killing effect on cells in the G1 and G2 + M phases, whereas cells in S were resistant to the drug. The change in their age-response was due to the Do value of the dose-survival curve rather than the Dq. Effects of cell progression were also examined at a low concentration of ACNU (5.0 micrograms/ml), which allowed 80% of treated cells to survive. Delayed transit was observed in the S phase, and more markedly in the G2 + M phase. The magnitude of these perturbations depended on the position of the cell cycle at which the drug was administered. Cells treated in the G1 and early S phases showed a much longer duration of S and G2 + M phases than cells treated in mid-S phase. Cells treated in the late S and G2 phases could normally pass through mitosis, but were subsequently blocked in the G2 phase following a prolonged S phase in the next cell cycle. These studies revealed that there seems to be some positive relationship of the effect of ACNU on cell progression and cell killing throughout the cell cycle.

Cell Cycle↗
PubMed1985

Change of inhibitor sensitivities of Escherichia coli F1-ATPase due to a mutational substitution of Phe for Ser at residue 174 of the beta subunit.

The F1-ATPase from the uncD11 mutant of E. coli (Kanazawa, H., Horiuchi, Y., Takagi, M., Ishino, Y., & Futai, M. (1980) J. Biochem. 88, 695-703), showed different enzymological properties from the wild-type enzyme. The mutant F1-ATPase had biphasic kinetics and essentially the same Km values as the wild-type enzyme, although its Vmax values were lower. The mutant enzyme showed altered sensitivities to dicyclohexylcarbodiimide (DCCD), azide and quercetin; it was less sensitive than the wild-type to quercetin and DCCD, and its Mg2+-dependent ATPase activity was slightly more resistant to azide than that of the wild-type, whereas its Ca2+-dependent activity was more sensitive. On the other hand, the mutant and wild-type F1 were inhibited equally by 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl). The fact that the Mg2+- and Ca2+-dependent F1-ATPase activities of the wild-type and mutant responded differently to quercetin and azide suggested that their mechanisms of action were different. Previous studies (Noumi, T., Mosher, M.E., Natori, S., Futai, M., & Kanazawa, H. (1984) J. Biol. Chem. 259, 10071-10075) indicated that Ser is replaced by Phe at residue 174 of the beta subunit of the mutant. Thus the Ser residue or its neighboring area(s) may constitute the binding site of DCCD, quercetin and azide.

Amino Acid Sequence↗
PubMed1985

Production of a monoclonal antibody to a membrane antigen of human T-cell leukaemia virus (HTLV1/ATLV)-infected cell lines from a systemic lupus erythematosus (SLE) patient: serological analyses for HTLV1 infections in SLE patients.

Human T-cell leukaemia virus (HTLV1/ATLV), which causes adult T cell leukaemia (ATL), is an infectious, lymphotrophic retrovirus unique for humans. The present study was undertaken to determine whether HTLV1 had any pathogenetic role for systemic lupus erythematosus (SLE). The incidence of antibodies to ATL cell-associated antigens (ATLA) in sera from patients with SLE and other collagen diseases was investigated by an indirect immunofluorescent cytoplasmic staining of an HTLV1-infected cell line (MT-1). A radioimmunoassay was also performed to detect antibodies to HTLV1 protein and crude membrane fraction derived from an HTLV1-producing cell line MT-2. Furthermore, an Epstein-Barr virus (EBV)-transformed B cell line (ES-1) was constructed from an SLE patient, which produced a monoclonal antibody (IgG, lambda) reactive to an HTLV1-related cell-membrane antigen expressed on MT-1 and MT-2 cells. The specific reactivity of the monoclonal antibody was analysed by an indirect immunofluorescent cell-membrane staining and a microcytotoxicity test. The incidence of anti-ATLA antibodies was not different among SLE and other collagen diseases. The monoclonal antibody produced by ES-1 stained and killed HTLV1-infected cell lines specifically, but did not react with other human lymphoid cell lines. This monoclonal antibody failed to react with peripheral blood mononuclear cells (PBMC), mitogen-induced T cell blasts, and iododeoxyuridine-treated T cells from SLE patients. Thus, a possible role of HTLV1 in the aetiology of SLE was not established.

Antibodies, Monoclonal↗