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Biomedical subjects

E Tsuchiya

Publications and source records attributed to E Tsuchiya.

At least 91 records · Page 5Linked to original sources
PubMed1988

Comparative histopathology of resected bronchial cancers of women in Hong Kong and Japan.

Pathological findings relating to lung cancers removed surgically from women at the Kowloon Hospital (KH), Hong Kong, and the Cancer Institute Hospital (CIH), Japan (77 and 54 cases respectively), were examined in order to clarify possible differences between Hong Kong Chinese and Tokyo Japanese women. Adenocarcinoma was the most frequent subtype encountered in both hospitals, but the rate was higher in CIH (90.9% in CIH and 68.8% in KH); that of large-cell carcinoma was second in KH where the rate was higher (14.3% in KH and 0%, in CIH). A remarkable difference was observed in the location of adenocarcinomas; the percentages of central and peripheral types were 60.4% and 24.5% respectively in KH, but 4% and 96% respectively in CIH. The proportion of the central type (45.5%) was higher than that of the peripheral type (27.3%) in large-cell carcinomas of KH. The number of adenocarcinomas having a bronchiolo-alveolar pattern (which is observed more frequently in peripheral-type adenocarcinomas) was higher in CIH (50%) than in KH (17%). Tall columnar cells were observed more often in KH (43.1% in KH and 20.8% in CIH), and hobnail and cuboidal cells more often in CIH (31.4 and 80.4% respectively in KH, and 54.2 and 95.8% respectively in CIH). The difference may be explained by the frequent presence of tall columnar cells in the glands of central carcinomas, and hobnail and cuboidal cells in peripheral adenocarcinomas. The frequent occurrence of the central type of adenocarcinoma and large-cell carcinoma appears characteristic of the lung carcinomas removed from women in Hong Kong. This suggests the existence of exogenous causative agents for lung cancer in Hong Kong females.

Adenocarcinoma↗
PubMed1988

Characterization of a DNA uptake reaction through the nuclear membrane of isolated yeast nuclei.

Isolated yeast nuclei were able to incorporate 3H-labeled pJDB219 DNA in vitro in the presence of ATP and Mg2+. The number of plasmid molecules incorporated into each nucleus was calculated to be 60 under the conditions we used. Enzyme-histochemical staining of the incorporated biotinylated pJDB219 with streptavidin-biotinylated-peroxidase complex indicated a uniform distribution of the incorporated plasmids within each nucleus. After intranuclear incorporation, substrate pJDB219 DNAs (open and closed circular forms) were changed to the linear form and were weakly digested over the longer incubation period (over 60 min). Facile release of the once-incorporated plasmid DNA was never observable; discharge of the incorporated [3H]pJDB219 during a 60-min incubation was less than 5%. The addition of adenylyl-imidodiphosphate, N,N'-dicyclohexylcarbodiimide (DCCD), or quercetin inhibited in vitro DNA uptake reaction. DCCD and quercetin inhibited the nuclear ATPase and apparent protein kinase, respectively; hence, the involvement of these enzymes in the nuclear DNA transport system was suggested.

Adenosine Triphosphate↗
PubMed1988

[Surgical treatment of lung cancer for both preserving lung function and maintaining radicality--bronchoplastic surgery].

Fifty cases with lung cancer given bronchoplastic surgery were discussed. Five-year survival rates of all of the cases, those with squamous cell carcinoma, pathological stage I + II cases and absolute curative cases were 36%, 42%, 46% and 59%, respectively, excluding operation death and hospital death. These results were virtually comparable with those of all of the cases with lung cancer which were ever resected in our hospital. The prognosis for cases with adenocarcinoma and of cases operated with bronchoplasty was poor because of direct bronchial invasion from inter-lobar lymph-node metastasis. Hence, this procedure could be better indicated for cases with squamous cell carcinoma, direct primary tumor invasion of the bronchus, and these in which absolute curative operation could be expected clinically. As is characteristic, suture failure occurred in 3 cases, and 2 of them which were followed by pulmonary arterial fistula died of massive bleeding. Preoperative BAI (Bronchial Arterial Infusion had been performed in all 3 cases. It is suggested that there may will be some relation between BAI and suture failure. From the viewpoint of technique, both blood supply preserving and tension relaxing procedures are the most important to avoid suture failure.

Adenocarcinoma↗
PubMed1987

Interaction with phospholipids of a membrane thiol peptidase that is essential for the signal transduction of mating pheromone in Rhodosporidium toruloides.

Interaction with phospholipids of a membrane thiol peptidase [referred to as trigger peptidase (TPase), T. Miyakawa et al. (1987) J. Bacteriol. 169, 1626-1631] that plays a key role in the signalling of a lipopeptidyl mating pheromone at the cell surface of pheromone-target cell (mating type a) of Rhodosporidium toruloides was studied. The activity of highly purified TPase which requires phospholipids was restored by reconstitution of the enzyme into liposomes prepared with phospholipids extracted from the yeast cell. The presence of Ca2+ was essential for both the reconstitution process and the catalytic reaction of TPase. Triton X-100 mixed micelles containing phospholipids also activated the enzyme. The specificity and stoichiometry of activation by phospholipids was investigated by determination of TPase in the presence of mixed micelles that contained defined classes and numbers of phospholipid molecules in the Triton X-100 micelles. It was demonstrated that TPase is activated by mixed micelles containing 2-6 molecules of phosphatidylserine or phosphatidylethanolamine. Other phospholipids of the membranes of this organism, such as phosphatidylcholine and phosphatidylglycerol, had little effect on activation, indicating that the amino group of the phospholipids may be required for the function of TPase. Direct evidence for the interaction of TPase and Triton X-100/phosphatidylserine mixed micelles was obtained by molecular sieve chromatography on Sephacryl S-200. These data established that a phospholipid bilayer is not a requirement for TPase activation, and that the purified enzyme can be activated by a relatively small number of phospholipid molecules of specific classes.

Calcium↗
PubMed1987

Inhibition of membrane Ca2+-ATPase in vitro by mating pheromone in Rhodosporidium toruloides, a heterobasidiomycetous yeast.

Direct addition of physiological concentrations of rhodotorucine A, a lipopeptide mating pheromone of Rhodosporidium toruloides, to the particulate fraction of the target cell strongly inhibited Ca2+-ATPase activity. The pheromone effect was mating-type specific. Membrane Ca2+-ATPase solubilized by a nonionic detergent and further purified by calmodulin-affinity chromatography was also inhibited by the pheromone. Rhodotorucine A S-oxide, a biologically inactive analogue, had no effect on Ca2+-ATPase. The results suggested that the inhibition of membrane Ca2+-ATPase is a critical event in the signaling of mating pheromone and the inhibition of membrane Ca2+-pump could be responsible for the pheromone-induced rapid raise of intracellular Ca2+ concentration reported.

Basidiomycota↗
PubMed1987

Purification and characterization of a Ca2+-dependent membrane peptidase involved in the signaling of mating pheromone in Rhodosporidium toruloides.

A mating-type-specific, membrane thiol peptidase (referred to as trigger peptidase) that seems to play a key role in the transmembrane signaling of the lipopeptidyl mating pheromone rhodotorucine A at the cell surface of mating type a cells of Rhodosporidium toruloides (T. Miyakawa, M. Kaji, T. Yasutake, Y.K. Jeong, E. Tsuchiya, and S. Fukui, J. Bacteriol. 162:294-299, 1985) was purified to homogeneity and characterized. The following lines of evidence support the contention that the enzyme we purified was the trigger peptidase: the identical specificity of hydrolysis at the Arg-Asn sequence of rhodotorucine A and the sensitivity of the reaction to sulfhydryl-blocking reagents; the identical specificity for the substrate, with a strict requirement for the presence of the lipid moiety; and the absence of the corresponding activity in the pheromone-producing strain (mating type A) and in a sterile mutant strain, M-39 (type a), that lacks trigger peptidase activity in vivo. The apparent molecular weight of trigger peptidase was estimated to be 68,000 by Sepharose 6B gel filtration in the presence of octylglucoside and 63,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Trigger peptidase alone was inactive but exhibited enzymatic activity with the simultaneous addition of Ca2+, membrane phospholipids, and a nonionic detergent such as octylglucoside. The concentration of Ca2+ required for maximum activation was approximately 1 mM. Only Mn2+ could replace Ca2+ at comparable concentrations. Among the phospholipids tested, only phosphatidylserine and phosphatidylethanolamine supported trigger peptidase activation. Solubilized trigger peptidase was strongly inhibited by antipain and phosphoramidon.

Basidiomycota↗
PubMed1987

[The influence of smoking on the development of various subtypes of pulmonary carcinoma].

The influence of smoking on the development of pulmonary carcinoma of various histological subtypes was analyzed in 244 primary and 84 metastatic lung cancer patients. The new WHO classification was used for histological diagnosis. The relative risk was calculated by the odds ratio. It was found that all the squamous, small-and large-cell carcinomas were derived from smokers with relative risks of 27.8, 7.5 and 5.6, respectively. On the other hand, adenocarcinoma had very little, if any, relationship with smoking, the relative risk being 1.5 in men and 1.3 in women. The high-risk group for squamous cell carcinoma in men was defined with a regression line of y (duration of smoking) on x (number of cigarettes per day) as y = -0.24 x + 48.6.

Adenocarcinoma↗
PubMed1987

Incidence of squamous metaplasia in large bronchi of Japanese lungs: relation to pulmonary carcinomas of various subtypes.

The incidence of bronchial squamous metaplasia in Japanese lungs was investigated in order to clarify the significance of this lesion for the development of lung cancer of various histological subtypes. The bronchi of 104 and 32 lungs resected, respectively, for primary or metastatic tumors were step-sectioned and examined histologically. The incidence of squamous metaplasia was particularly high (83% of cases, 8-11% of sections) in male lungs bearing primary squamous or small cell carcinoma whereas it was low (43% of cases, 3% of sections) in lungs of both sexes with adenocarcinoma, the latter figures being about the same as those for lungs with secondary metastatic tumors. Although the overall incidence of lung squamous metaplasia in Japanese is much lower than in the U.S., the present data demonstrate a high level in association with squamous or small cell carcinoma, directly comparable to that of Americans. However, atypical metaplasia, or dysplasia, was encountered much less frequently than in the U.S. A topographical study of 7 minute or small squamous cell carcinomas revealed 3 to have adjacent and 2 to have nearby areas of squamous metaplasia. However, 2 cases were found to be completely free of squamous metaplastic lesion. Thus, squamous metaplasia may be associated with the development of squamous cell carcinoma but would appear not to be an obligatory step in the development of this neoplasm.

Bronchi↗
PubMed1987

[Spindle cell squamous carcinoma of the lung--two case reports].

Two cases of spindle cell squamous carcinoma of the lung are presented. Both cases were female heavy smokers aged 73 and 55. The carcinomas, 7.5 and 6.0 cm in diameter respectively, were located at the peripheral portion of the right lower lung lobes. Direct invasion to the diaphragma and metastasis to the chest wall were observed in the first case but no metastasis was observed in the second case. Histologically, both carcinomas showed a biphasic appearance due to the presence of a squamous cell carcinoma component and a spindle cell sarcomatous component with marked cellular pleomorphism, but no neoplastic bone, cartilage or muscle. Transitional area of two components were seen in the second case.

Aged↗
PubMed1986

[Pulmonary malignant lymphoma--a case report].

A case of pulmonary malignant lymphoma is reported. A 65-year-old woman had no complaint. But chest roentgenography and CT revealed an infiltrating shadow with marked airbronchogram in the left S3. TBLB revealed marked subepithelial lymphocytic infiltration of the bronchial wall. Because the shadow had gradually enlarged, malignancy was suspected and lobectomy was performed. The resected specimen showed a 60 X 56 X 30 mm greyish-yellow, medullary tumor with intrapulmonary metastasis. Microscopically, well-differentiated small lymphocytic tumor cells severely infiltrated the pulmonary parenchyma, pleura and bronchial cartilage. There was no lymph node metastasis or extrapulmonary involvement. Immunohistochemical study proved the monoclonality of the K chain. She was treated with chemotherapy postoperatively.

Aged↗
PubMed1985

Biosynthesis and secretion of tremerogen A-10, a polyisoprenyl peptide mating pheromone of Tremella mesenterica.

The biosynthetic pathway of tremerogen A-10, a polyisoprenyl peptide mating pheromone produced by mating type AB cells of the heterobasidiomycetous yeast Tremella mesenterica, was investigated by immunological techniques with antibody specific to the peptide moiety of the pheromone. Using the biological assay and the radioimmunoassay of the pheromone and its related substances, it was suggested that the peptide is synthesized near the end of logarithmic phase of growth with a temporary accumulation of precursors in the cell. The precursors initially appeared in membrane-bound form and were subsequently converted to soluble forms prior to the secretion. The pheromone acquired its biological activity during the secretion. In the presence of tunicamycin or compactin, pheromone production was blocked with accumulation of membrane-bound precursors. Monensin, however, blocked pheromone production with accumulation of soluble precursors. The molecular species which accumulated in the presence of the antibiotics were analyzed by immunoprecipitation followed by sodium dodecyl sulfate/urea/polyacrylamide gel electrophoresis. In the absence of the inhibitors, membrane-bound precursors with molecular masses of 28 kDa, 12 kDa, 7.8 kDa and 2.8 kDa were found. The precursors which accumulated in the presence of tunicamycin and compactin were the 12-kDa and 28-kDa species, respectively. The results suggested that membrane-bound very high-molecular-mass precursors were initially formed and their extensive modifications, including glycosylation, farnesylation and proteolytic digestion, occur in the membrane. Based on these data, a biosynthetic and secretory pathway was postulated.

Animals↗
PubMed1985

Involvement of protein sulfhydryls in the trigger reaction of rhodotorucine A, a farnesyl peptide mating pheromone of Rhodosporidium toruloides.

The involvement of protein sulfhydryls for the signaling of rhodotorucine A, a mating pheromone produced by mating type A cells of Rhodosporidium toruloides, was investigated by the use of sulfhydryl compounds. The sulfhydryl-blocking reagent 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB; Ellman's reagent) strongly inhibited both the biological effect of the pheromone on the recipient cell and the hydrolysis of the pheromone, which is catalyzed by the mating type-specific surface endopeptidase of the recipient cell. Conversely, the two reactions were markedly enhanced by the presence of the reducing reagent dithiothreitol. The inhibitory effect of DTNB on the pheromone response of the recipient cell was specific to an initial stage of the differentiation; once it had initiated, the reagent had no effect on its progression. The results suggested that dithiothreitol enhances and DTNB impairs the efficiency with which the pheromone triggers sexual d differentiation. The reaction of DTNB with cellular protein sulfhydryls was highly restricted to those at the exterior surface of the membrane due to the impermeability of the reagent through the membrane. Phosphorylation of endogenous proteins, which is modulated by the pheromone added to an in vitro phosphorylation system, was also blocked by DTNB. The results showed that sulfhydryl groups are involved in the pheromone hydrolysis by the surface endopeptidase of the recipient cell and that pheromone metabolism is indispensable for the signaling reaction. We suggest that the modulation of protein phosphorylation of membrane proteins by the pheromone is an initial transmembrane response coupled to pheromone metabolism.

Animals↗
PubMed1985

Transient increase of Ca2+ uptake as a signal for mating pheromone-induced differentiation in the heterobasidiomycetous yeast Rhodosporidium toruloides.

The role of Ca2+ for the signaling of rhodotorucine A, a mating pheromone of Rhodosporidium toruloides, was investigated. The efficiency with which the target cells responded to the mating pheromone was dependent on the Ca2+ concentration in the medium. The pheromone induced a very rapid and transient increase of Ca2+ uptake in the recipient cell. We concluded that the transient increase in the intracellular Ca2+ concentration could play an essential role in the control of differentiation by the pheromone.

Animals↗
PubMed1984

Characteristic alteration in the nuclear DNA polymerase activity during the cell division cycle of Saccharomyces cerevisiae.

Specific activity of the intranuclear DNA polymerase in cdc-mutant cells of Saccharomyces cerevisiae was found to be characteristically changed by arrest in their specific stage of cell division cycle without a notable alteration in the total cellular activity. The activities were low in the nuclei of cdc 25, cdc 28 and cdc 4, which were arrested in early to mid G1 phase by temperature shift-up, and in the nuclei of wild-type cells (A364A), which were arrested in early G1 phase by alpha-factor treatment, while high level of the activity was found in the nuclei of cdc 7 and cdc 8, which were arrested at late G1 and S phase, respectively. Activity-gel analysis of DNA polymerase in the nuclear extracts revealed the presence of two active peptides (120K and 72K), and the characteristic decrease in both active peptides was induced by arrest in early to mid G1 phase. Consequently, it is strongly suggested that intranuclear DNA polymerase activity alters in a dependent fashion on progression of cell division cycle. Subunit analysis indicated that the purified DNA polymerase I is constructed from two subunit peptides of 120K and 62K, and the large subunit possesses catalytic activity.

Cell Cycle↗