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Biomedical subjects

K Nishimura

Publications and source records attributed to K Nishimura.

At least 577 records · Page 32Linked to original sources
PubMed1994

[Superior vena cava-right atrial appendage direct anastomosis for repair of partial anomalous pulmonary venous connection to superior vena cava].

Successful repair was performed for a 7-year-old male with a diagnosis of partial anomalous pulmonary venous connection (PAPVC) to superior vena cava (SVC) and superior sinus venosus atrial septal defect (ASD). The SVC was divided above the orifice of the anomalous pulmonary vein and the cephalad end of the SVC was anastomosed directly to the right atrial appendage. A patch was used to divert pulmonary venous flow from the orifice of the SVC through superior sinus venosus ASD into the left atrium. Postoperative course was uneventful with normal sinus rhythm. There was no evidence of vena caval or pulmonary venous obstruction. At 3-month after surgery, sinus node function was confirmed to be normal by electrophysiological study. This is useful alternative method for repair of PAPVC to high or middle SVC.

Anastomosis, Surgical↗
PubMed1994

[MEP (methotrexate, etoposide and cisplatin) and M-VAC (methotrexate, vinblastine, doxorubicin and cisplatin) for advanced uroepithelial cancer--a preliminary report of MEP as second line chemotherapy for recurrence after M-VAC].

Combination chemotherapy with methotrexate, vinblastine, doxorubicin and cisplatin (M-VAC regimen) or with methotrexate, etoposide and cisplatin (MEP regimen) was administered to 32 patients with advanced measurable uroepithelial cancers. Fifteen patients among them were adequately treated with M-VAC regimen, and 11 with MEP regimen. Complete remission was not achieved clinically in any patients. Partial remission occurred in 73.3% (11/15) of M-VAC patients and 72.7% (8/11) of MEP patients. Of eleven MEP patients, six were treated with MEP therapy as second line chemotherapy for the recurrence after other chemotherapy (5 cases after M-VAC, 1 case after intraarterial cisplatin). They showed a considerable response (4 patients, PR; 2 patients, MR) and an appreciable remission period, not inferior to those of first line chemotherapy with M-VAC regimen. The present study shows that MEP may be a promising regimen for advanced uroepithelial cancers, especially as a second line chemotherapy for relapsed cases after M-VAC therapy.

Adult↗
PubMed1993

Novel inhibitors of poly(ADP-ribose) glycohydrolase.

The inhibitory effects on poly(ADP-ribose) glycohydrolase purified from human placenta of three classes of chemically defined tannins; gallotannins, ellagitannins and condensed tannins, were examined in vitro. Oligomeric ellagitannins were found to be most potent inhibitors of poly(ADP-ribose) glycohydrolase, their potencies increasing with increasing number of monomeric residues (dimer < trimer < tetramer). Monomeric ellagitannins and gallotannins were less inhibitory. Condensed tannins, which consist of an epicatechin gallate oligomer without a glucose core, were not appreciably inhibitory. A structure-activity study showed that higher-order conformations of the conjugates with glucose of hexahydroxydiphenoyl and valoneoyl groups, which are unique components of ellagitannins, cooperatively potentiated the inhibitory activity.

Enzyme Inhibitors↗
PubMed1993

Cloning and sequencing of the hemE gene encoding uroporphyrinogen III decarboxylase (UPD) from Escherichia coli K-12.

Among the photoresistant revertants of the visA-deleted (hemH-deleted) strain of Escherichia coli K-12, three mutants defective in the hemE gene encoding uroporphyrinogen III decarboxylase (UPD) were identified. Using one of the mutants, we cloned and sequenced the hemE of E. coli. We found an open reading frame of 353 codons, which encoded a predicted amino acid (aa) sequence that exhibited a high degree of homology over its entire length to the aa sequence of UPD from humans and other organisms. This hemE was located at 90.3 min near the hupA gene on the linkage map of the E. coli chromosome.

Amino Acid Sequence↗
PubMed1993

The existence of a dispensable fibrillar layer on the wall surface of mycelial but not yeast cells of Aureobasidium pullulans.

Wall surface ultrastructure of Aureobasidium pullulans was studied by freeze-etching. Yeast cells had a smooth wall surface as in typical yeast species. Mycelial cells and chlamydospores had an extra layer on the wall surface made mostly of fibrils. The fibrils were 20 nm in diameter, and thicker than typical major fungal wall skeletal fibrils of beta-glucan and chitin. This layer was apparently easily detached from the wall proper, presumably as a result of enzymic activity or by physical means, suggesting that it is a physiologically dispensable wall component.

Candida albicans↗
PubMed1993

Isolation and identification of an endogenous inhibitor of enkephalin-degrading enzymes from bovine spinal cord.

We isolated a potent inhibitor of enkephalin-degrading enzymes from bovine spinal cord and determined its amino-acid sequence and inhibitory activity toward enkephalin-degrading enzymes. This new substance, designated spinorphin, is composed of a heptapeptide (Leu-Val-Val-Tyr-Pro-Trp-Thr). The inhibitory activity (IC50) of this new substance toward enkephalin-degrading enzymes, purified from monkey brain, was found to be 3.3 micrograms/ml against aminopeptidase, 1.4 micrograms/ml against dipeptidyl aminopeptidase, 2.4 micrograms/ml against angiotensin-converting enzyme, and 10 micrograms/ml against enkephalinase. This new substance did not show inhibitory activity toward enkephalin degrading enzymes purified from kidney and blood. Above results suggest that this substance is a new neuromodulator in the spinal cord.

Amino Acid Sequence↗
PubMed1993

Transformation of monoamine oxidase-B primary amine substrates into time-dependent inhibitors. Tertiary amine homologues of primary amine substrates.

A family of N-methylated and N,N-dimethylated alkyl and arylalkylamines was prepared and more than half of the analogues were shown to be time-dependent pseudo-first-order inhibitors of monoamine oxidase-B. Some of the time-dependent inactivators were reversible and others were irreversible with respect to prolonged dialysis following inactivation. Partition ratios ranged from zero to 11,000. These results are rationalized in terms of a combination of an inductive effect and a stereoelectronic effect as a result of hindered rotation of an active site covalent adduct. A molecular mechanics calculation indicates that there is at least 10 kcal/mol of torsional energy to be overcome in order for the enzyme adduct to be released. These findings show that tertiary amine homologues of primary amine substrates of monoamine oxidase are time-dependent inhibitors, and this should be useful in the design of new inactivators of this enzyme.

Alkylation↗
PubMed1993

Expression of P-cadherin in gastric carcinomas and its reduction in tumor progression.

The expression of P-cadherin, one of the Ca(2+)-dependent cell-cell adhesion molecules, in human gastric carcinomas was examined by Northern blotting, Western blotting and immunohistochemistry. P-cadherin mRNA was expressed in all the gastric carcinoma tissues examined, whereas no message was detected in non-neoplastic mucosa. By Western-blot analysis, P-cadherin protein was expressed in 83% and 29% of the well-differentiated and poorly differentiated gastric adenocarcinomas, respectively, the incidence being significantly different. Immunohistochemically, P-cadherin immunoreactivity was localized on the cell surface or the cell-to-cell borders of well-differentiated adenocarcinomas. P-cadherin was not detected in Borrmann's type-4 or scirrhous carcinomas where the tumor cells proliferate diffusely with productive fibrosis. The level of P-cadherin expression in stage-2 carcinomas was significantly higher than in stage-I carcinomas. In the case of patients in stages 2 to 4, however, the level of P-cadherin expression decreased as the stage progressed, the difference between stages 2 and 3 and between stages 3 and 4 being significant. Our findings suggest that P-cadherin might play an important role in the development of well-differentiated gastric adenocarcinomas and the decreased expression of P-cadherin might be responsible for the infiltrative growth and progression of gastric carcinomas.

Cadherins↗
PubMed1993

Rapid, extensive and reversible vacuolation of Schizosaccharomyces pombe induced by amphotericin B.

The fission yeast Schizosaccharomyces pombe has no large vacuoles under normal growth conditions, although budding yeasts usually have large central vacuoles. The minimum inhibitory concentration of amphotericin B to S. pombe was 0.5 microgram ml-1; treatment with 0.2 microgram ml-1 for 20 min induced rapid and extensive vacuolation in S. pombe exponential phase cells. Growth rate of the cells with 0.2 microgram ml-1 amphotericin B was much reduced for 6 h, showing extensive vacuolation. Vacuolation in itself was not fatal: on removal of the drug, most cells recovered gradually and eventually multiplied.

Amphotericin B↗
PubMed1993

Ubiquinone systems of Coccidioides immitis, the causative agent of coccidioidomycosis.

The ubiquinone (coenzyme Q) systems of eleven strains of Coccidioides immitis were determined by high performance liquid chromatography (HPLC). The ubiquinone profile of the fungi was shown to be homogeneous: in all of the strains, ubiquinone-10 (Q-10) was demonstrated to be the major component, with Q-9 as a minor component. The results imply that the ubiquinone system may serve as an additional phenotypic criterion for identifying the fungus.

Coccidioides↗
PubMed1993

Inactivation of monoamine oxidase B by analogues of the anticonvulsant agent milacemide (2-(n-pentylamino)acetamide).

Analogues of the anticonvulsant agent milacemide (1,2-(n-pentylamino)acetamide), in which the carboxamide group is changed to a nitrile (2), a carbethoxy group (3), a carboxylic acid (4), a cyanomethyl group (5), and a trifluoromethyl group (6), were synthesized and tested as substrates and inactivators of monoamine oxidase B (MAO B). The carboxylic acid was neither a substrate nor an inactivator. The trifluoromethyl compound was not soluble in buffer even when organic cosolvents were added, so it could not be tested. All of the other compounds were both substrates and time-dependent irreversible inactivators of MAO B. A plot of the logarithm of kcat/k(inact) (a measure of the efficiency of the inactivators) versus sigma I (Figure 1) shows a linear free energy relationship between the inactivator efficiency and the electron-withdrawing ability of the substituent. As the electron-withdrawing ability increases, the partition ratio decreases indicating that inactivation is becoming more efficient relative to substrate turnover to product. Milacemide was the least efficient of the compounds tested; the nitrile 2 was the most efficient.

Acetamides↗
PubMed1993

Increased expression of p34cdc2 and its kinase activity in human gastric and colonic carcinomas.

We examined the expression of p34cdc2 and its kinase activity in human gastric and colonic carcinoma cell lines and carcinoma tissues and studied its relation with a tumor-suppressor gene product, p53. All the gastric and colonic cancer cell lines expressed p34cdc2 and showed its kinase activity at various levels. When the cells were arrested in mitotic metaphase by the use of nocodazole, p34cdc2 kinase activity was induced and p53 was apparently phosphorylated. Of 12 gastric carcinoma cases, 11 (91.7%) showed higher p34cdc2 kinase activity in tumor tissues than in corresponding non-neoplastic mucosa. The protein kinase activities in the individual cases were well correlated with the levels of p34cdc2 protein expression. A good correlation was also found between the expression of p34cdc2 and proliferating cell nuclear antigen (PCNA). Almost all the colonic carcinomas showed higher cdc2 kinase activity and increased p34 expression when compared with non-neoplastic mucosa. Interestingly, most of the gastric and colonic carcinomas having high cdc2 kinase activity expressed high levels of p53. These findings suggest that the increased p34cdc2 kinase activity might cause the development and proliferation of gastric and colonic carcinomas, partly through abnormal p53 accumulation.

Blotting, Western↗
PubMed1993

Subarachnoid fluid collection in infants complicated by subdural hematoma.

In the natural history of infantile extracerebral fluid collections, subarachnoid fluid collection itself is regarded as a benign lesion, and surgical treatment is not indicated. As this condition is age-related and self-limiting, spontaneous resolution can be expected in most cases by 2-3 years of age. However, out of 20 cases of infantile subarachnoid fluid collection in an 8-year period, 3 infants developed subdural hematoma. Infantile subarachnoid fluid collection seems to be prone to complicate subdural hematoma. Surgical treatment should be considered when subarachnoid fluid collection is complicated by subdural hematoma due to arachnoid ruptures or tearing of the bridging veins. Therefore, all patients should be observed closely and measures should be taken to prevent head trauma since it may precipitate subdural hematoma.

Diagnosis, Differential↗