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Biomedical subjects

T Ohmori

Publications and source records attributed to T Ohmori.

At least 181 records · Page 10Linked to original sources

Relationship of HBsAg subtypes with HBeAg/anti-HBe status and chronic liver disease. Part I: Analysis of 1744 HBsAg carriers.

A total of 1744 HBsAg carriers were investigated to determine whether there are clinical differences among HBsAg subtypes or not. Although adr was more predominant than adw in 1078 asymptomatic carriers as well as in 666 carriers with liver dysfunction, the adr carriers had liver dysfunction more frequently than the adw carriers (p = 0.005). In addition, the adr carriers were more often positive for HBeAg and less often positive for anti-HBe than the adw carriers (p less than 0.001). Multivariate analyses indicated that the HBsAg subtypes were associated with liver dysfunction not directly but through the relationship between the HBsAg subtypes and HBeAg/anti-HBe status. HBeAg/anti-HBe status of each age bracket in the adr carriers and in the adw carriers suggested that adr carriers are seroconverted later than adw carriers. In conclusion, HBsAg subtypes may affect the development of chronic liver disease, through their association with HBeAg/anti-HBe status.

Adult↗

Relationship of HBsAg subtypes with HBeAg/anti-HBe status and chronic liver disease. Part II: Evaluation of epidemiological factors and suspected risk factors of liver dysfunction.

In this study, we examined a possibility that epidemiological factors or suspected risk factors of liver dysfunction could account for the different HBeAg/anti-HBe status or the different prevalence of liver dysfunction between the adr and adw carriers. A total of 428 HBsAg carriers were surveyed of their age, sex, racial background, socioeconomic status, place of residence, birthplace, alcohol consumption, smoking habit, and history of blood transfusion as epidemiological factors or suspected risk factors of liver dysfunction. Adjustment for those variables using multivariate analyses did not substantially affect the association of the HBsAg subtypes with either prevalence of liver dysfunction or HBeAg/anti-HBe status. HBsAg subtypes seem to directly affect HBeAg/anti-HBe status and consequently influence development of chronic liver disease.

Adult↗

[Informed consent of the family in the chemotherapy for lung cancer].

In Japan where the question of cancer notification has yet to be resolved, it is difficult to obtain an informed consent from the patient himself in clinical studies of the chemotherapies for cancer. In fact, the chemotherapy is administered while not enough explanation is given to the family let alone the patient. Such is the present situation. For the purpose of finding out the best possible method at present, we carried out a method whereby an informed consent of the family is substituted for a consent of the patient in phase II study of inoperable non-small cell carcinoma of the lung. As a result, the consent was obtained from 21 (91.3%) out of 23 families. This method should be taken into consideration as a feasible one under the present circumstances. It was in only one family (4.3%) that a consent on the notification of diagnosis from the family to the patient was obtained. In order for the informed consent to be established, efforts to form a social consensus on cancer notification are needed.

Adult↗

Purification and characterization of a novel GTP-binding protein with a Mr value of 24,000 from rat liver.

About 15% of the total GTP-binding proteins (G proteins) of rat liver homogenate was found in the microsomes-Golgi complex fraction. From this fraction, we purified to near homogeneity and characterized a G protein with a Mr value of 24,000 (24K G). 24K G specifically bound guanosine 5'-(3-Q-thio) triphosphate (GTP gamma S), GTP and GDP with a Kd value for GTP gamma S of about 30 nM. 24K G bound maximally about 0.7 mol of GTP gamma S/mol of protein. 24K G hydrolyzed GTP to liberate Pi with a turnover number of about 0.008 min-1. 24K G was not copurified with the beta gamma subunit of heterotrimeric G proteins. The partial amino acid sequences of 24K G revealed that this protein was a novel small G protein.

Animals↗

A fourth subunit is present in cytochrome c oxidase from the thermophilic bacterium PS3.

A new putative subunit was found in cytochrome c oxidase (aa3-type) of the thermophilic bacterium PS3. The N-terminal amino acid sequence of this approximately 12 kDa protein coincides with the deduced sequence of an open reading frame found downstream from the gene encoding subunit I of the PS3 cytochrome oxidase [(1988) J. Biochem. 103, 606-610]. This small hydrophobic protein, composed of 109 amino acid residues after the initial methionine residue has been processed, shows homology with the subunit IV (cyoD product) of cytochrome bo-type quinol oxidase of Escherichia coli.

Amino Acid Sequence↗

Nucleotide sequence of the gene coding for four subunits of cytochrome c oxidase from the thermophilic bacterium PS3.

The gene coding for four subunits of cytochrome aa3-type oxidase was isolated from a genomic DNA library of the thermophilic bacterium PS3 and sequenced. The N-terminus of each subunit was also sequenced to verify the initiation site of the reading frame. The deduced amino acid sequences contained 615 amino acid residues for subunit I (CO1/caaB product), 333 residues for subunit II (CO2/caaA product), 207 residues for subunit III (CO3/caaC product), and 109 residues for subunit IV (CO4/caaD product) after processing. Re-examination of the sequencing of caa revealed a longer open reading frame for CO1, which contains 14 transmembrane segments instead of 12 [Sone et al. (1988) J. Biochem. 103, 606-610], although the main portions of the sequences constituting cytochrome a (FeA), cytochrome a3 (FeB), and CuB are correct. PS3 CO2 has an additional sequence for cytochrome c after the CuA binding protein portion with 2 transmembrane segments, which is homologous to the mitochondrial counterpart. PS3 CO3 has DCCD-binding glutamyl residues but contains only 5 transmembrane segments, unlike the mitochondrial counterpart, which has 7 segments. The subunits of PS3 cytochrome oxidase (aa3-type) show clear similarity in amino acid sequences with those of cytochrome bo-type oxidase from Escherichia coli as well, in spite of the difference of hemes. PS3 CO3 and CO4 are much more similar to E. coli CO3 and CO4 than to mitochondrial CO3 and CO4, respectively.

Amino Acid Sequence↗

Detection of proteins that recognize platinum-modified DNA using gel mobility shift assay.

Using a gel mobility shift assay, we have identified proteins, in the nuclear extracts of a human lung cancer cell line, that recognize cis-diamminedichloroplatinum(II) (cis-DDP, CDDP)-modified DNA. A 158-base-pair double-stranded DNA fragment, derived from pBR322 plasmid DNA, was modified by either CDDP, tetrachloro(dl-trans)-1,2-diaminocyclohexaneplatinum(IV) (tetraplatin) or trans-DDP (the stereoisomer of CDDP and clinically ineffective). These platinum drug-modified probes were incubated with nuclear extracts and analyzed by gel mobility shift assay. Proteins in the extracts selectively recognized the clinically active platinum-modified DNA fragment. No binding to the trans-DDP-modified DNA fragment was observed. These proteins may play a role in the cytotoxicity or in a DNA repair process.

Cisplatin↗

The role of bone fracture at the site of carcinogen exposure on nickel carcinogenesis in the soft tissue.

The influence upon nickel subsulfide (alpha-Ni3S2; Ni-SS)-induced carcinogenesis in the soft tissue of bone fracture at the site of Ni-SS exposure was studied using female Fischer rats. During the one year of the experiment, the group subjected to bone fracture exhibited the shortest tumor induction time and survival time, and a significantly higher metastatic rate. The present study may suggest a model for the metastasis of human soft tissue tumors.

Animals↗

Biological study of alcohol dependence syndrome with reference to ethnic difference: report of a WHO Collaborative Study.

Inherited deficiency of acetaldehyde dehydrogenase type I (ALDH-I) was found in 43% (50/117) of normals, 33% (27/82) of schizophrenics, but only 4% (5/113) of alcoholics among Japanese. The ALDH-I deficiency was never found, however, in 146 mostly schizophrenic subjects from Europe (Basel, Moscow, Zagreb), Australia (Nedlands), India (Lucknow), Morocco (Casablanca) and Mexico (Mexico City). It was demonstrated that ALDH-I deficiency produces the flushing syndrome which inhibits the development of drinking habit and alcohol dependence syndrome.

Alcoholism↗

Interleukin-2 receptor antigen, leukocyte common antigen, and Ki-1 antigen-expressing gastric plasmacytoma. A case report with an immunohistochemical study.

A case of primary gastric plasmacytoma expressing various surface and cytoplasmic antigens is reported. With the use of formalin-fixed and deparaffinized sections, 13 different antibodies were applied. Neoplastic plasma cells revealed monoclonal IgG and kappa light chain in the cytoplasm, and expressed epithelial membrane antigen, Ki 67 antigen, cytokeratin, CD 22 antigen, interleukin-2 receptor antigen, leukocyte common antigen and Ki-1 (CD 30) antigen. However, tumor cells were devoid of HLA-DR antigen. These data suggest that the neoplastic plasma cells are at the plasmoblastic stage of maturation and express various surface and cytoplasmic phenotypes.

Aged↗

Difference in the induction of macrophage interleukin-1 production between viable and killed cells of Listeria monocytogenes.

T-cell-mediated immunity to Listeria monocytogenes in mice, as determined by delayed-type hypersensitivity and acquired resistance, was induced by immunization with viable bacteria but not with killed bacteria, even when killed cells were injected in a high dose or repeatedly. T cells obtained from mice immunized with viable L. monocytogenes were readily stimulated with killed-bacterial antigens, resulting in T-cell proliferation in vitro and expression of a delayed footpad reaction in vivo. After immunization with killed-bacterial vaccine, T-cell responsiveness to interleukin 2 (IL-2) never developed but a lower level of responsiveness to IL-1 appeared later than with T cells from mice immunized with viable bacteria. When IL-1 production by macrophages was examined in vitro, viable L. monocytogenes stimulated a high level of IL-1 release while killed bacteria did not. Avirulent strains which were ineffective in the induction of T-cell mediated immunity were incapable of inducing IL-1 production as well. The impaired ability of killed bacteria to stimulate IL-1 production was confirmed by the level of IL-1 mRNA expression. These results suggested that the ineffectiveness of killed L. monocytogenes vaccine is not due to loss or lack of antigenic epitopes but may be ascribed to insufficient induction of IL-1 production in the initial stage of the immune response in vivo.

Bacterial Vaccines↗

Horseshoe kidney found in a female cadaver.

The present report describes a case of malformation of the kidney, of the type known as horseshoe kidney, in an 83-year-old Japanese female used for student dissection practice. In this case, the kidney consisted of three parts: the original kidneys on both sides and an isthmus between them. The kidneys formed a U-shaped structure as a result of fusion at the inferior poles of the original kidneys. As a whole, the structure presented a typical horseshoe shape. The renal artery system as well as the position of the kidney was almost normal except for a surplus artery into the isthmus. The incidence of horseshoe kidney was estimated to be 0.27% in our department for the period from 1975 to 1988.

Aged↗

Improved assay method for activity of thyroid peroxidase-catalysed coupling of iodotyrosine residues of thyroglobulin utilizing h.p.l.c. for analysis of iodothyronines.

The coupling of iodotyrosine residues of thyroglobulin (Tg) catalysed by thyroid peroxidase (TPO) has scarcely been studied with respect to the TPO of abnormal human thyroid glands. The present paper proposes a rapid and convenient assay method applicable for determining the coupling activity of a sample of less than 500 mg from each patient's thyroid. The main characteristics of the method are as follows: (i) mitochondrial/microsomal fractions of thyroid glands were treated with sodium cholate plus trypsin, and the supernatants obtained by ultracentrifugation were directly used for the assay of coupling and peroxidase activity of TPO; (ii) the formation of iodotyrosine residues catalysed by TPO was performed by using chemically iodinated Graves'-disease Tg containing 41 iodine atoms per molecule and with a high iodotyrosine and a low iodothyronine content; (iii) newly synthesized iodothyronine residues (thyroxine, 3,5,3'-tri-iodothyronine, and 3,3',5'-tri-iodothyronine) were analysed by h.p.l.c. after hydrolysis of Tg with proteinases and extraction of iodothyronines with ethyl acetate.

Chromatography, High Pressure Liquid↗

Small molecular weight GTP-binding proteins in human platelet membranes. Purification and characterization of a novel GTP-binding protein with a molecular weight of 22,000.

When guanosine 5'-(3-O-[35S]thio)triphosphate (GTP gamma S)-binding activity was assayed in the particulate and cytosol fractions of human platelets, most activity was found in the particulate fraction. GTP-binding proteins (G proteins) were extracted from the particulate fraction by sodium cholate and purified by several column chromatographies. At least three G proteins with Mr values of about 21,000, 22,000, and 24,000 (21K G, 22K G, and 24K G, respectively) were separated in addition to the stimulatory (Gs) and inhibitory (Gi) regulatory GTP-binding proteins of adenylate cyclase. Among them, the amount of 22K G was more than 10-fold of those of other G proteins. 22K G was purified to near homogeneity and characterized. 22K G specifically bound GTP gamma S, GTP, and GDP, with a Kd value for GTP gamma S of about 50 nM. [35S]GTP gamma S binding to 22K G was inhibited by pretreatment with N-ethylmaleimide. 22K G hydrolyzed GTP to liberate Pi, with a turnover number of 0.01 min-1. 22K G was not copurified with the beta gamma subunits of Gs and Gi and was not recognized by the antibodies against the ADP-ribosylation factor for Gs and the ras protein. The peptide map of 22K G was different from those of the smg-25A and rho proteins, which we have purified from bovine brain membranes. 21K G was identified to be the c-ras protein, but 24K G was unidentified. These results indicate that there are multiple G proteins in platelet membranes and that a novel G protein (22K G) is a major G protein in platelets.

Blood Platelets↗

Two cases of resected esophageal mucoepidermoid carcinoma.

Two cases of resected esophageal mucoepidermoid carcinoma are described herein. Case 1, a 56-year-old man, had an ulcerous lesion of 6.5 cm in length, in the lower esophagus and a small skin tumor of 0.5 cm in diameter, in the forehead. Pathologic studies of both tumors revealed mucoepidermoid carcinoma. This case was therefore considered to be a primary tumor of the esophagus with skin metastasis. The patient was alive and well when last seen, 15 months after his operation. Case 2, a 66-year-old man, had a long ulcerous lesion of 9.0 cm in length, in the mid-thoracic and lower esophagus. The tumor had invaded the aorta and the membranous portion of the left main bronchus, and therefore complete resection was impossible. The patient died of mediastinal recurrence only 3 months after his operation in spite of postoperative irradiation. A review of the literature showed that this tumor has a much greater incidence of rapid recurrence and distant metastasis, regardless of treatment, than usual squamous cell carcinoma of the esophagus. In order to establish and accurate diagnosis of mucoepidermoid carcinoma, alcian blue and/or mucicarmin staining of the endoscopic biopsy specimen should be performed if the tumor contains both glandular and squamous cell carcinoma.

Aged↗

Regulation of thyroid peroxidase activity by thyrotropin, epidermal growth factor and phorbol ester in porcine thyroid follicles cultured in suspension.

The activity of thyroid peroxidase (TPO) in porcine follicles cultured for 96 h in suspension with five hormones (5H) still attained over 50% of that in the freshly isolated follicles. On the other hand, the activity in those cultured with 5H + TSH (6H) was several times higher than that cultured with 5H after 96 h, although an initial decrease of TPO activity during the first 24 h of culture was observed in both conditions. The ability of follicles to metabolize iodide (uptake and organification) when cultured with 6H for 96 h was also several times higher than that of those cultured with 5H. The half-maximal dose of TSH for stimulation of TPO activity and iodide metabolism was 0.03-0.04 mU/ml and the effect was mediated by cAMP. These results indicate that in porcine thyroid follicles in primary suspension culture, TPO activity as well as the ability of iodide metabolism is induced by chronic TSH stimulation. In addition, epidermal growth factor (EGF, 10(-9)M) and phorbol 12-myristate 13-acetate (PMA, 10(-8) M) completely inhibited TSH stimulation on both activities and also basal (5H) activity of iodide metabolism.

Animals↗

Transition of starving Dictyostelium cells to differentiation phase at a particular position of the cell cycle.

The relationship between proliferation and differentiation in Dictyostelium discoideum Ax-2 was analyzed with reference to the cell-cycle position at the onset of starvation, using cells synchronized by temperature shift (11.5 degrees C-22.0 degrees C). To examine how far Ax-2 cells at any particular phase of the cell cycle are able to progress through the cycle in response to nutritional deprivation, we measured temporal changes in cell number and nuclearity after starvation. Nuclear DNA synthesis in synchronously developing cells was also monitored by pulse-labeling with [methyl-3H]thymidine. Increase in cell number and subsequent DNA synthesis occurred in cells just before mitosis (referred to as T0.5 cells and T1 cells; 0.5 h and 1 h after the shift-up from 11.5 degrees C to 22.0 degrees C respectively), but not in T3, T5, or T7 cells. When T1 cells were incubated for 6 h in the absence of external nutrients, they (T1 + 6 cells) exhibited developmental features similar to T7 cells, which most rapidly acquired chemotactic sensitivity to 3',5'-cyclic adenosine monophosphate (cAMP) and EDTA-resistant cohesiveness after starvation. Thus, it is quite likely that Ax-2 cells may progress through the cell cycle to a particular point (possibly the cell-cycle position of T7 cells), irrespective of the presence or absence of nutrients, and enter the differentiation phase from this point under conditions of nutritional deprivation. There was no difference in the ratio of prestalk to prespore cells in migratory pseudoplasmodia derived from cells that had been starved at other cell-cycle positions.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Cycle↗