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Biomedical subjects

S Kato

Publications and source records attributed to S Kato.

At least 1,153 records · Page 64Linked to original sources
PubMed1991

[Clinical application of Modulith SL20 on extracorporeal shock wave lithotripsy for upper urinary tract calculi].

Thirty-nine patients, 27 males and 12 females with renal and ureteral stones, were treated using the Modulith SL 20 between October 1990 and January 1991. Thirty-three of the 39 cases had a single session of extracorporeal shockwave lithotripsy (ESWL) and the other six cases had two sessions. The pulverization rate of ESWL by this device was 84.6%. According to the X-rays taken 21 days after ESWL, of the 37 cases, 14 (37.8%) were stone-free, 18 (48.7%) had residual sandy stones less than 4 mm in diameter, five (13.5%) had residual stone fragments larger than 4.1 mm in diameter, and two cases were not clear. Using the criterion of cases which can be expected to have spontaneous passage, in other words, residual stones less than 4 mm in diameter, lithotripsy with the Modulith SL 20 was regarded as "effective" in 32 of the 37 cases (86.5%). As side effects of this treatment, hematuria was observed for several days after ESWL in all patients, but not other serious complications were observed. Among the 37 cases in which the grade could be evaluated the evaluation for 24 (64.9%) was "useful" and that for 13 (35.1%) "useful to some extent". Therefore, ESWL was performed very successfully.

Adult↗
PubMed1991

Two bcr/abl fusion gene products, P210bcr/abl and P190bcr/abl, are equally sensitive to the protein tyrosine phosphatase of mature granulocytes.

Two bcr/abl fusion gene products with tyrosine kinase activity have been found in two phenotypes of Philadelphia chromosome (Ph1)-positive leukemia. P210bcr/abl (P210) is associated with Ph1-positive chronic myelogenous leukemia (CML), while P190bcr/abl is associated with Ph1-positive acute leukemia. We compared the susceptibility of 32Pi-labeled P210 from K-562 cells and P190 from MR-87 cells to protein tyrosine phosphatase (PTPase). PTPase, present in the lysate of mature granulocytes from CML patients as well as in the lysate of these cells from normal subjects, effectively dephosphorylated the CML-associated P210 and the acute leukemia associated P190. This PTPase activity was specifically inhibited by ZnCl2; it was not present in lymphocyte lysates, and was not inhibited by neutralization with anti-CD45 antibody. Since P210 and P190 were equally sensitive to the PTPase, the difference in leukemic phenotypes associated with the expression of these two tyrosine kinases cannot be explained by the differential dephosphorylation of P210 and P190.

Cellular Senescence↗
PubMed1991

[A case of quadricuspid aortic valve associated with coronary arterial legion].

A case of quadricuspid aortic valve is reported in a patient with coronary artery disease and abdominal aortic aneurysms. A 54-year-old male who had undergone aortic replacement because of abdominal aortic aneurysms three years before presentation was readmitted due to complaints of angina pectoris and palpitations. Aortography and coronary arteriography revealed severe aortic regurgitation and proximal occlusion of LAD and RCA. Surgical correction consisted of aortic valve replacement with a Björk-Shilely valve and coronary revascularization of LAD. During the operation, a quadricuspid aortic valve with one smaller and three larger cusps that showed mild myxomatous degeneration without dystrophic calcification and normal coronary arterial orifices were noted. Accordingly, severe aortic regurgitation may have resulted from the dysfunction of congenital malformed cusps and acquired sclerotic coronary disease was the main cause of the chest pain.

Angina Pectoris↗
PubMed1991

[Bone marrow transplantation for pediatric solid tumor].

Bone marrow transplantation permits the use of greatly intensified cytoreductive therapy for cancer. Since 1981, fifteen children with disseminated solid tumor were treated by this method (6 Nb1, 6 Lymphoma, 1 PNET, 1 Hb1, 1 YST.). Eight out of 15 (53%) have been alive and well 2-96 (median 45) months after BMT. Though toxicity is severe, high dose chemo-radiotherapy using BMT after reaching complete remission with well scheduled induction chemotherapy and surgery is concluded as a treatment of choice for pediatric malignant solid tumor in advanced stage.

Bone Marrow Transplantation↗
PubMed1991

Intralobular heterogeneity of carbon tetrachloride-induced oxidative stress in perfused rat liver visualized by digital imaging fluorescence microscopy.

Spatial and temporal alterations in carbon tetrachloride-induced oxidative stress were studied in perfused hepatic microcirculatory units of the rat by digital imaging microscopic fluorography using dichlorofluorescin diacetate, a hydroperoxide-sensitive fluorogenic probe. The surface of the liver loaded with dichlorofluorescin was microscopically visualized, and the fluorescence of dichlorofluorescin (DCF), a highly fluorescent molecule generated by hydroperoxide-mediated oxidation of dichlorofluorescin, was digitally processed. After completing the experiments, fluorescein-labeled albumin was injected into the perfusate to confirm the state of sinusoidal perfusion and the topography of hepatic microangioarchitecture in the area studied. During transportal infusion of carbon tetrachloride, DCF fluorescence was observed predominantly in the pericentral area and was attenuated by pretreatment with SKF-525A, suggesting the involvement of cytochrome P-450. After peaking at the maximum level, the pericentral DCF fluorescence gradually decreased in parallel to the loss of viability, implicating the causal role of intracellular hydroperoxide formation in hepatocellular injury. In retrogradely perfused liver, in which intralobular O2 gradient was reversed, no significant activation of DCF fluorescence was observed among hepatic lobules. It is therefore conceivable that the zonal heterogeneity of carbon tetrachloride-induced lipid peroxidation may depend on at least two factors, sinusoidal oxygenation and the intralobular distribution of cytochrome P-450. Furthermore, development of the current technique will provide a useful method to investigate the microtopography of oxidative stress in organ microcirculatory units.

Animals↗
PubMed1991

[Surgical repair of partial anomalous pulmonary venous connection to the coronary sinus--a case report of PAPVC with mitral and tricuspid valve regurgitation in adult].

We have recently performed a successful repair of a total right anomalous pulmonary venous connection to the coronary sinus associated with mitral and tricuspid regurgitation. A 54-year-old female was inaccurately diagnosed as atrial septal defect associated with mitral and tricuspid regurgitation preoperatively. Operation revealed that all the right pulmonary veins connected to the coronary sinus. Mitral regurgitation which might be caused by distortion of the anterior leaflet was repaired by McGoon's technique. A Carpentire-Edwards ring was employed for the tricuspid annuloplasty. Repair of the atrial septal defect was undertaken with a pericardial septation patch which was sutured in place. The roof of the coronary sinus was widened by cutback, so that blood from the pulmonary veins could drain into the left atrium. The postoperative course was uneventful, except for a supraventricular arrhythmia.

Coronary Vessel Anomalies↗
PubMed1990

Tissue-specific enhancer of the human multidrug-resistance (MDR1) gene.

Identification of cis-regulatory sequences is a first step in analyzing the regulation of the human multidrug-resistant 1 (MDR1) gene which encodes the 170-kilodalton membrane P-glycoprotein in normal tissues and tumor cells. We have studied several overlapping genomic clones containing the 5'-flanking region of the gene. These clones span about 30 kilobases (kb) of contiguous DNA containing 10 kb of the gene and 20 kb of the 5'-flanking sequence. The nucleotide sequence of the first exon and the 2 kb preceding the exon were determined. DNA sequences containing the 5'-flanking regions were linked to the chloramphenicol acetyltransferase (CAT) gene. For transient CAT assay, we have employed six cell lines, including human cancer KB, vincristine-resistant VJ-300 derived from KB, mouse adrenal tumor Y-1, African green monkey kidney CV-1, mouse fibroblast NIH3T3, and human adrenal carcinoma SW-13 cells. Promoter activity was very weak regardless of the length of the promoter region in mouse adrenal tumor Y-1 and monkey kidney CV-1 cells, in which endogenous P-glycoprotein was expressed. Introduction of a 700-base genomic DNA fragment from a site located at 10 kb far upstream of the initiation site increased the transcription of the CAT gene in Y-1, CV-1, and SW-13 cells. However, no significant increase in the CAT activity could be observed in NIH3T3, KB, and VJ-300 cells. This fragment markedly augmented the expression of the CAT gene regardless of orientation or position, and it acted in a cell type-specific manner even with heterogenous promoters. Our present study suggests that the 700-base pair fragment may carry a tissue-specific transcriptional enhancer that is active in at least some adrenal and kidney-derived cell lines.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

Antitumor efficacy of vaccinia virus-modified tumor cell vaccine.

The antitumor efficacies of vaccinia virus-modified tumor cell vaccines were examined in murine syngeneic MH134 and X5563 tumor cells. UV-inactivated vaccinia virus was inoculated i.p. into C3H/HeN mice that had received whole body X-irradiation at 150 rads. After 3 weeks, the vaccines were administered i.p. 3 times at weekly intervals. One week after the last injection, mice were challenged i.p. with various doses of syngeneic MH134 or X5563 viable tumor cells. Four methods were used for preparing tumor cell vaccines: X-ray irradiation; fixation with paraformaldehyde for 1 h or 3 months; and purification of the membrane fraction. All four vaccines were effective, but the former two vaccines were the most effective. A mixture of the membrane fraction of untreated tumor cells and UV-inactivated vaccinia virus also had an antitumor effect. These results indicate that vaccine with the complete cell structure is the most effective. The membrane fraction of UV-inactivated vaccinia virus-absorbed tumor cells was also effective. UV-inactivated vaccinia virus can react with not only intact tumor cells but also the purified membrane fraction of tumor cells and augment antitumor activity.

Animals↗
PubMed1990

Temperature dependence of the ripple structure in dimyristoylphosphatidylcholine studied by synchrotron X-ray small-angle diffraction.

The ripple structure of 1,2-dimyristoyl-L-phosphatidylcholine (DMPC) multibilayer containing excess water (60 wt%) was studied by synchrotron X-ray small-angle diffraction. The (0,1) spacing which corresponds to the ripple repeat distance depends on temperature: At 13 degrees C the (0,1) spacing is 14.15 nm, the spacing decreases at higher temperatures and reaches 12.1 nm at 23.5 degrees C, just below the main transition temperature. The spacing is in good agreement between heating process and cooling process except for the supercooling region. The result suggests that the rearrangement of the ripple structure takes place during temperature change successively. The Landau-de Gennes free energy equation explains well the temperature dependence of the ripple repeat distance.

Dimyristoylphosphatidylcholine↗
PubMed1990

Herpes simplex virus glycoprotein D. Protective immunity against murine herpetic keratitis.

%$%%protective effect of glycoprotein D (gD) immunization against murine herpetic keratitis was investigated. gD was purified by affinity chromatography using anti-gD monoclonal antibodies. Prior immunization with gD was shown to be effective in protecting mice from both the development of stromal keratitis and the spread of the virus to the central nervous system. The level of serum antibodies for virus neutralization, as well as for complement-dependent cytolysis (CDC), was significantly elevated in gD-immunized animals. Cellular immunity, however, was not detected. These results indicate that two antibody-mediated defense mechanisms--virus neutralization and CDC--were responsible for the protective effect observed in our study.

Animals↗
PubMed1990

Potentiation of anti-platelet aggregating activity of cilostazol with vascular endothelial cells.

We developed the new system in which the platelet aggregation was detected turbidimetrically using glass cuvettes which were coated cultured vascular endothelial cells. Using this system, we evaluated the effect of cilostazol, having a selective inhibitory effect on cAMP-PDE, on the ADP-induced platelet aggregation in the presence of endothelial cells. Cilostazol inhibited the platelet aggregation dose-dependently in the presence or absence of endothelial cells. The inhibitory effect of cilostazol on platelet aggregation was potentiated by the presence of endothelial cells, and the slope of the dose-response curves were identified to be as the same between both experiments in the presence and the absence of endothelial cells. The pretreatment of endothelial cells with aspirin reversed the potentiated inhibitory effect of cilostazol on the platelet aggregation with endothelial cells. The amount of 6-keto-prostaglandin F1 alpha accumulated in the cuvette was reduced in this condition. On the other hand, the inhibitory effect of prostaglandin E1 on the platelet aggregation was not potentiated by the presence of endothelial cells. These results suggest that the endothelium-derived prostacyclin plays a role on the potentiation of anti-platelet aggregatory effect of cilostazol.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1990

Studies on transfer of varicella-zoster-virus specific T-cell immunity from bone marrow donor to recipient.

The transfer of antigen-specific cellular immunity in human bone marrow transplantation (BMT) was studied in 49 donor-recipient pairs, using a varicella-zoster-virus (VZV) specific lymphoproliferative response (LPR) assay. Posttransplant VZV-LPR could be serially measured in 31 long-term surviving recipients. VZV-specific T-cell immunity was detected in the early posttransplant period in 4 of 16 recipients who were, and whose donors were, immune to VZV before BMT, but two of those positive responses diminished in the first 100 days posttransplant. No positive response was detected in the immediate posttransplant period when either only the recipient or the donor was immune to VZV pretransplant. Herpes zoster or chickenpox developed in the recipients depending on a history of pretransplant VZV infection when the VZV-LPR became negative, and recovery from VZV infection was always followed by quick conversion of VZV-LPR. Long-lasting positive VZV-LPR was observed in the two recipients who experienced VZV infection in the immediate pretransplant period and received marrow graft from an immune donor. Our results indicate that a simple or direct transfer of VZV-specific cellular immunity from a marrow donor to a recipient cannot be expected in usual clinical bone marrow transplantation and that there might be a collaboration or recruitment of immune responses involving both donor and recipient that permits the VZV-LPR to remain positive posttransplant.

Bone Marrow Transplantation↗
PubMed1990

Histochemical and immunohistochemical evidence for hepatic zone 3 distribution of alcohol dehydrogenase in rats.

The distribution of alcohol dehydrogenase in the hepatic acinus was examined by both histochemical and immunohistochemical approaches. The immunohistochemical method using anti-alcohol dehydrogenase antibody indicated zone 3 predominance of this enzyme in the hepatic acinus, whereas a conventional histochemical method showed slight zone 1 predominance. However, when the histochemical technique was improved by using 2% glutaraldehyde instead of formalin for fixation and by adding phenazine methosulfate (0.33 mmol/L) to the staining incubation mixture, this method also supported zone 3 predominance of alcohol dehydrogenase. Evidence for zone 3 distribution of alcohol dehydrogenase may be of value in elucidating the mechanism of zone 3 liver damage by alcohol.

Alcohol Dehydrogenase↗
PubMed1990

Cytoplasmic argyrophilic inclusions in neurons of pontine nuclei in patients with olivopontocerebellar atrophy: immunohistochemical and ultrastructural studies.

Patients with olivopontocerebellar atrophy (OPCA) were studied, and cytoplasmic inclusions were observed in some of the remaining neurons of the pontine nuclei, nuclei reticularis tegmenti pontis and arcuate nuclei. The cytoplasmic argyrophilic inclusions were demonstrated by silver impregnation techniques such as Bielschowsky and Bodian staining. With hematoxylin and eosin stain, the inclusions were sharply demarcated and appeared pale. The inclusions were not stained by the following routine histological methods: Klüver-Barrera, phosphotungstic acid hematoxylin, Holzer, periodic acid-Schiff, Mallory azan, alcian blue, nile blue, Masson trichrome, Congo red, thioflavine S, oil red O and Sudan black B stains. Immunohistochemistry with anti-ubiquitin antiserum showed that these inclusions were ubiquitinated. However, the inclusions did not react with any of the following antibodies (Abs) or antisera: anti-phosphorylated neurofilament (NF) Ab, anti-nonphosphorylated NF Abs (160 and 200 kDa), anti-paired helical filament antiserum, anti-tau antiserum, anti-tubulin Abs (alpha and beta), anti-microtubule-associated protein antiserum, anti-glial fibrillary acidic protein antiserum, anti-vimentin Ab, anti-desmin Ab, anti-cytokeratin Abs (low and high molecular weights), anti-actin antiserum, anti-skeletal myosin antiserum and anti-myelin basic protein Ab. Ultrastructurally, the inclusion bodies noted in OPCA were composed primarily of fibrils having a width ranging from about 24 to 40 nm, which were entirely coated with osmiophilic granular material along their whole length. They were occasionally intermingled with a few filaments about 10 nm in width. Electron microscopical examination on silver-impregnated specimens revealed that each granule-coated fibril had a great affinity for silver particles. In elucidating the pathogenesis of OPCA, it was considered to be an important neuropathological finding that some of the remaining pontine neurons affected by OPCA developed characteristic cytoplasmic argyrophilic inclusions.

Adult↗
PubMed1990

Ubiquitin and phosphorylated neurofilament epitopes in ballooned neurons of the extraocular muscle nuclei in a case of Werdnig-Hoffmann disease.

The extraocular muscle nuclei in one case of Werdnig-Hoffmann disease were examined immunocytochemically using antibodies against phosphorylated neurofilament (pNF) and ubiquitin (UBQ). The oculomotor and trochlear nuclei showed several chromatolytic ballooned neurons. All ballooned neurons contained epitopes of pNF and UBQ. pNF were present mainly in the periphery of the cell in a ring-like shape and were occasionally seen in the center of some cells. On the other hand, the structures stained by the antibody to UBQ were small vesicles or granules and most of them were aggregated in the center of the cell. These distribution patterns of pNF and UBQ may be unique in Werdnig-Hoffmann disease, since similar patterns were reported in other types of neurons of Werdnig-Hoffmann disease but were not seen in two other motor neuron diseases: classical amyotrophic lateral sclerosis, and familial amyotrophic lateral sclerosis with posterior column and spinocerebellar tract involvement.

Brain↗
PubMed1990

Presence of two different fibril subtypes in the Pick body: an immunoelectron microscopic study.

A study of Pick bodies (PBs) was performed using immunohistochemical, ultrastructural and immunoelectron microscopic techniques. Ultrastructurally, the PBs in the granular neurons of the dentate fascia of Ammon's horn were composed of randomly distributed straight fibrils (14.5 +/- 2.1 nm in diameter), intermingled with a few constricted fibrils. The constricted fibrils had a periodicity of 157 +/- 11 nm, and were 28.7 +/- 3.3 nm wide at their widest point midway between the constrictions and 15.3 +/- 3.2 nm wide at the point constriction. A few straight fibrils approximately 15 nm in diameter appeared to morphologically transform into fibrils with constrictions at approximately 160-nm intervals. Immunoelectron microscopy revealed that the straight fibrils, the constricted fibrils, and the transitional form (straight fibrils linked with constricted fibrils) had the same immunoreactivity to anti-tau antiserum. The two different subtypes of Pick fibrils, i.e., the straight fibrils and the constricted fibrils, have interchangeable appearances and a common pathomechanism is suggested to underlie the formation of these two subtypes.

Brain↗