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Biomedical subjects

T Oishi

Publications and source records attributed to T Oishi.

At least 37 records · Page 2Linked to original sources
PubMed2001

[A survival case of severe Legionella longbeachae pneumonia].

A 56-year-old Japanese male was admitted to Toyohashi Municipal Hospital because of fever, cough, and dyspnea. Chest X-ray film showed bilateral alveolar infiltrates. He suffered from severe hypoxemia and was given a diagnosis of acute respiratory distress syndrome. He was also complicated with disseminated intravascular coagulation and pseudomembranous colitis. He fully recovered by intensive treatment with antibiotics, mechanical ventilation and endotoxin eliminating therapy. Legionella longbeachae was isolated from his respiratory specimens and was regarded as the etiologic agent of his pneumonia.

Humans↗
PubMed2001

Dual roles of RNA helicase A in CREB-dependent transcription.

RNA helicase A (RHA) is a member of an ATPase/DNA and RNA helicase family and is a homologue of Drosophila maleless protein (MLE), which regulates X-linked gene expression. RHA is also a component of holo-RNA polymerase II (Pol II) complexes and recruits Pol II to the CREB binding protein (CBP). The ATPase and/or helicase activity of RHA is required for CREB-dependent transcription. To further understand the role of RHA on gene expression, we have identified a 50-amino-acid transactivation domain that interacts with Pol II and termed it the minimal transactivation domain (MTAD). The protein sequence of this region contains six hydrophobic residues and is unique to RHA homologues and well conserved. A mutant with this region deleted from full-length RHA decreased transcriptional activity in CREB-dependent transcription. In addition, mutational analyses revealed that several tryptophan residues in MTAD are important for the interaction with Pol II and transactivation. These mutants had ATP binding and ATPase activities comparable to those of wild-type RHA. A mutant lacking ATP binding activity was still able to interact with Pol II. In CREB-dependent transcription, the transcriptional activity of each of these mutants was less than that of wild-type RHA. The activity of the double mutant lacking both functions was significantly lower than that of each mutant alone, and the double mutant had a dominant negative effect. These results suggest that RHA could independently regulate CREB-dependent transcription either through recruitment of Pol II or by ATP-dependent mechanisms.

Adenosine Triphosphatases↗
PubMed2001

Japanese family with glucocorticoid-remediable aldosteronism diagnosed by long-polymerase chain reaction.

We report a Japanese family with glucocorticoid-remediable aldosteronism (GRA) in whom gene abnormality was identified by the long-polymerase chain reaction (PCR) method. The proband was a 21-year-old female incidentally found to have high blood pressure (173/107 mmHg). Laboratory tests showed hypokalemia (3.7 mmol/l), and high plasma aldosterone concentration (PAC, 234 pg/ml) with suppressed plasma renin activity (PRA, <0.1 ng/ml/h). The circadian rhythm pattern and the results of a rapid adrenocorticotrophic hormone (ACTH) test indicated ACTH-dependent changes in PAC. Imaging studies showed no adrenal mass on either side. A dexamethasone (Dexa) suppression test (1.0 mg/day orally for 7 days) showed a marked decrease of PAC 2 days after administration, and this decreased level was maintained throughout Dexa administration. High blood pressure and hypokalemia also improved during Dexa treatment. The proband's younger sister was 19 years old and had hypertension, PAC of 231 pg/ml, and PRA <0.1 ng/ml/h. The mother was 53 years old and had hypertension, PAC of 98.5 pg/ml, and PRA <0.1 ng/ml/h. The proband's elder sister was a 22-year-old normotensive with PAC of 110 pg/ml and PRA of 0.1 ng/ml. Long-PCR was performed for detection of the chimeric gene associated with GRA, using DNA samples from all four cases and two normal control subjects. Although the aldosterone synthase gene was expressed among all DNA samples, the chimeric gene was detected only in the proband, her younger sister and her mother. Our clinical data and genetic investigation confirmed the presence of GRA in this Japanese family.

Adult↗
PubMed2001

[A case of primary HIV infection with oral candidiasis not diagnosed by western blot].

Seroconversion to human immunodeficiency virus(HIV) associated with an illness characterized by fever, sore throat, and lymphadenopathy, sometimes with rash, diarrhea, and vomiting. Leukopenia and liver dysfunction also can occur in some patients. The antibody response associated with HIV infection is directed against a variety of viral proteins. Western blot analysis(WB) is used currently for determining HIV-1 infection. A 47-year-old man whose wife was infected with HIV was found to have contracted primary HIV infection. His first HIV antibody examination 4 weeks after speculated exposure was negative by particle agglutination(PA) method and WB. Approximately 2 weeks later he experienced fever, general fatigue, oral candidiasis. His second laboratory examination showed positive PA and indeterminate WB tests, an HIV-RNA PCR of 4.4 x 10(5) copies/ml, 223 CD4+ lymphocytes/microliter, and liver dysfunction. Two weeks later, all of his symptoms and the abnormal lab data had improved with antifungal therapy alone and no anti-HIV therapy. Subsequently, it took 16 more weeks before HIV infection could be diagnosed by WB. It is necessary to adopt an appropriate HIV-1 PCR method to shorten the diagnostic window in primary HIV infection.

Biomarkers↗
PubMed2000

A Role of RNA Helicase A in cis-Acting Transactivation Response Element-mediated Transcriptional Regulation of Human Immunodeficiency Virus Type 1.

RNA helicase A (RHA) has two double-stranded (ds) RNA-binding domains (dsRBD1 and dsRBD2). These domains are conserved with the cis-acting transactivation response element (TAR)-binding protein (TRBP) and dsRNA-activated protein kinase (PKR). TRBP and PKR are involved in the regulation of HIV-1 gene expression through their binding to TAR RNA. This study shows that RHA also plays an important role in TAR-mediated HIV-1 gene expression. Wild-type RHA preferably bound to TAR RNA in vitro and in vivo. Overexpression of wild type RHA strongly enhanced viral mRNA synthesis and virion production as well as HIV-1 long terminal repeat-directed reporter (luciferase) gene expression. Substitution of lysine for glutamate at residue 236 in dsRBD2 (RHA(K236E)) reduced its affinity for TAR RNA and impaired HIV-1 transcriptional activity. These results indicate that TAR RNA is a preferred target of RHA dsRBDs and that RHA enhances HIV-1 transcription in vivo in part through the TAR-binding of RHA.

Amino Acid Sequence↗
PubMed2000

Expression of GAP-43 and SCG10 mRNAs in lateral geniculate nucleus of normal and monocularly deprived macaque monkeys.

We performed nonradioactive in situ hybridization histochemistry (ISH) in the lateral geniculate nucleus (LGN) of the macaque monkey to investigate the distribution of mRNA for two growth-associated proteins, GAP-43 and SCG10. GAP-43 and SCG10 mRNAs were coexpressed in most neurons of both magnocellular layers (layers I and II) and parvocellular layers (layers III-VI). Double-labeling using nonradioactive ISH and immunofluorescence revealed that both GAP-43 and SCG10 mRNAs were coexpressed with the alpha-subunit of type II calcium/calmodulin-dependent protein kinase, indicating that both mRNAs are expressed also in koniocellular neurons in the LGN. We also showed that GABA-immunoreactive neurons in the LGN did not contain GAP-43 and SCG10 mRNAs, indicating that neither GAP-43 nor SCG10 mRNAs were expressed in inhibitory interneurons in the LGN. GABA-immunoreactive neurons in the perigeniculate nucleus, however, contained both GAP-43 and SCG10 mRNAs, indicating that both mRNAs were expressed in inhibitory neurons in the perigeniculate nucleus, which project to relay neurons in the LGN. Furthermore, to determine whether the expression of GAP-43 and SCG10 mRNAs is regulated by visual input, we performed nonradioactive ISH in the LGN and the primary visual area of monkeys deprived of monocular visual input by intraocular injections of tetrodotoxin. Both mRNAs were downregulated in the LGN after monocular deprivation for 5 d or longer. From these results, we conclude that both GAP-43 and SCG10 mRNAs are expressed in the excitatory relay neurons of the monkey LGN in an activity-dependent manner.

Animals↗
PubMed2000

Diversity of opsin immunoreactivities in the extraretinal tissues of four anuran amphibians.

The pineal complex, deep brain, and skin have been known to function as extraretinal photoreceptors in non-mammalian vertebrates. To see the diversity of localization of extraretinal photoreceptors in lower vertebrates having different habitats, we analyzed the opsin-like immunoreactivities in anuran amphibians, Xenopus laevis, Rana catesbeiana, Rana nigromaculata, and Bufo japonicus. An antiserum (toad Rh-AS) was raised against rhodopsin purified from the retinas of Japanese toad, B. japonicus. In the retina of all the anurans examined, the outer segments of rods were immunopositive to toad Rh-AS. The outer segments of most pinealocytes were immunopositive in R. catesbeiana, R. nigromaculata, and B. japonicus. The outer segments of photoreceptor-like cells within the frontal organ of R. nigromaculata were immunostained. Interestingly, toad Rh-AS immunostained many secretory cells of mucous glands in the head skin of B. japonicus, implying the presence of a novel photoreceptive molecule. Within the hypothalamus, toad Rh-AS immunostained many cells in the magnocellular preoptic nucleus of R. catesbeiana and B. japonicus. Toad Rh-AS also labeled cerebrospinal fluid (CSF)-contacting cells in the anterior preoptic nucleus of R. nigromaculata and those adjacent to the lateral ventricle within the septum of R. catesbeiana. Thus the distribution patterns of the rhodopsin-like immunoreactivities among the anurans were highly diverged, and there was no relationship between the distribution patterns and their habitats. J. Exp. Zool. 286:136-142, 2000.

Animals↗
PubMed2000

Induction of hepatic stellate cell proliferation by LPS-stimulated peripheral blood mononuclear cells from patients with liver cirrhosis.

We studied hepatic stellate cell proliferation in vitro. Peripheral blood mononuclear cells (PBMC) from patients with chronic active hepatitis C (CAH) and liver cirrhosis (LC) were cultured for 24h in the presence or absence of Escherichia coli lipopolysaccharides (LPS). Hepatic stellate cell proliferation induced by the culture supernatants was measured, and interleukin-1 (IL-1) and IL-6 levels in the culture supernatants were quantified. Culture supernatants of LPS-stimulated PBMC from LC patients induced rat hepatic stellate cell proliferation by almost 2.8-fold (stimulation index, 2.83 +/- 1.41) compared with when the cells were cultured without addition of PBMC culture supernatants. Production of IL-1beta was significantly higher in the culture supernatants of both CAH and LC patients than in those of ten healthy controls (P < 0.01 and P < 0.05, respectively). But there was no significant correlation between IL-1 production and the induction of hepatic stellate cell proliferation by the culture supernatants. Although there were no significant differences in IL-6 production by LPS-stimulated PBMC among healthy controls and CAH and LC patients, we observed a significant correlation between IL-6 production and the induction of hepatic stellate cell proliferation in the culture supernatants of LC patients. Rat hepatic stellate cells themselves produced IL-6, and treatment with IL-6 antisense oligodeoxynucleotides suppressed the cell proliferation, suggesting that IL-6 is an autocrine growth factor for hepatic stellate cells. The addition of human recombinant IL-6 (hrIL-6) augmented rat hepatic stellate cell proliferation, indicating that excessive IL-6 may further facilitate cell proliferation. These findings suggest that a cytokine cascade including IL-6 may participate in hepatic stellate cell proliferation in LC patients when they are exposed to endotoxin.

Animals↗
PubMed2000

Hemoglobin content in intramucosal gastric carcinoma as a marker of histologic differentiation: a clinical application of quantitative electronic endoscopy.

BACKGROUND: It has been suggested that the endoscopic color of intramucosal gastric carcinoma is correlated with mucosal vascularity within the carcinomatous tissue. The development of electronic endoscopy has made it possible to quantitatively measure the mucosal hemoglobin volume, using a hemoglobin index. The aims of the present study were to investigate whether this hemoglobin index is useful for evaluating the change in color of early gastric carcinoma and to verify the diagnostic value of this index for distinguishing between histologic degrees of differentiation. METHODS: The ratios of the hemoglobin index of cancerous and non-cancerous mucosa for 26 differentiated and 18 undifferentiated intramucosal gastric carcinomas were determined from electronic endoscopic imaging data. RESULTS: The mean ratio of the hemoglobin index of cancerous and non-cancerous mucosa in the differentiated gastric carcinomas was higher than it was in the undifferentiated carcinomas (1.23: 95% CI [1.15, 1.31] versus 0.84: 95% CI [0.81, 0. 88]). The sensitivity and specificity for discriminating undifferentiated from differentiated carcinoma were 100% and 85%, respectively. CONCLUSION: Measurement of mucosal hemoglobin volume (hemoglobin index) is useful for evaluating the endoscopic color of early gastric carcinoma quantitatively and may be helpful in distinguishing differentiated from undifferentiated carcinoma.

Adult↗
PubMed2000

Alteration of telomerase activity in ovarian cancer after chemotherapy.

To elucidate the relationship between telomerase activity and chemosensitivity in epithelial ovarian cancer, telomerase activity and telomere length (TRF) were examined before and after chemotherapy. Of 21 patients, 9 patients responded to chemotherapy and 12 did not. The positivity of telomerase activity did not significantly differ between responders and nonresponders. There were no differences in the mean length and the distribution of TRF between the two groups. Those distributions became narrow after chemotherapy in both groups. Seven nonresponders (58.3%) exhibited an increase in telomerase activity after chemotherapy but none of the responders showed an increase in activity. Telomerase activity may relate to chemosensitivity in epithelial ovarian cancer.

Aged↗
PubMed2000

Alteration of a p53 gene status affects outcome of patients with recurrent ovarian cancer.

The aim of this longitudinal study was to examine whether and how the p53 gene is altered in patients with recurrent ovarian cancer and to determine the significance of p53 mutation in recurrent tumors. The primary and recurrent tumors were examined in 15 patients who had recurrent epithelial ovarian cancer, and whose primary tumor contained a wild-type p53 gene. The interval between cytoreductive surgery and the appearance of recurrence ranged from 5. 2 to 63.6 months (mean 23.4 months). Mutations in the p53 gene were screened by polymerase chain reaction single strand conformation polymorphism analysis and determined by cycle sequencing. Mutation of the p53 gene in the recurrent tumor was found in 7 of the 15 patients (46.7%). Estimated 3- and 5-year survival rates were 57.1 and 0%, respectively, for patients with p53 gene mutation detected in the recurrence tumor, and 75.0% and 37.5% for patients without the mutation (p = 0.0155). The interval between cytoreductive surgery and the appearance of recurrence did not differ between those groups (549.7 +/- 102.2 vs. 832.9 +/- 283.8 days). Mean survival time after recurrence was significantly better in the patients without mutation (438.6 +/- 56.4 vs. 873.0 +/- 157.5 days, p = 0.0125). The present study suggests that p53 gene mutation frequently occurs in recurrent ovarian cancer and that alteration of p53 gene status affects salvage chemotherapy. This phenomenon affects the prognosis of recurrent disease and may predict outcome.

Aged↗
PubMed2000

Hyperthyroidism in a patient with TSH-producing pituitary adenoma coexisting with thyroid papillary adenocarcinoma.

A 27-year-old woman who presented with a left thyroid nodule was found to have hyperthyroidism caused by a syndrome of inappropriate secretion of TSH. The levels of free T3, free T4 and TSH were 9.50 pg/mL, 4.05 ng/dL and 2.16 microU/mL, respectively. Magnetic resonance imaging of the head revealed a pituitary macroadenoma. The TSH response to TRH stimulation was normal and responses of other anterior pituitary hormones to stimulation tests were also normally preserved. Administration of octreotide with iodine successfully reversed hyperthyroidism prior to total resection of pituitary adenoma, which was followed by hemithyroidectomy of the left thyroid five months later. Histologically, the resected pituitary adenoma was a TSH-producing adenoma (TSH-oma) and the thyroid nodule was a papillary adenocarcinoma. Serum TSH diminished to undetectable levels immediately following pituitary adenomectomy but gradually normalized over nine months. Coexistence of a TSH-oma with thyroid cancer is very rare and only two similar cases have previously been documented. This combination raises the possibility that TSH may be involved in tumorigenesis in the thyroid gland.

Adenocarcinoma, Papillary↗
PubMed2000

Laparoscopic-assisted hepatectomy (LAH) for the treatment of hepatocellular carcinoma.

The treatment of hepatocellular carcinoma associated with liver cirrhosis necessitates local therapy in some patients because of severe hepatic dysfunction. Percutaneous ethanol injection therapy, the local therapy for such cancer of the liver, and percutaneous microwave coagulation therapy are detailed. The significant disadvantages of these procedures is their inability to evaluate precisely whether the tumor will develop complete necrosis after treatment because the cancer tissue cannot be excised with use of these procedures. Conversely, laparoscopic hepatectomy, which is minimally invasive surgery, has a disadvantage, that is, its difficulty in complex maneuvers, including hemostasis, ligation, and suture. The authors developed laparoscopic-assisted hepatectomy, which is hepatectomy by small incision during laparotomy with the use of laparoscopic observation. This report describes laparoscopic-assisted hepatectomy, which may allow the solving of problems with percutaneous ethanol injection therapy, percutaneous microwave coagulation therapy, and laparoscopic hepatectomy.

Aged↗
PubMed1999

Hypernuclear acetylation in atherosclerotic lesions and activated vascular smooth muscle cells.

Recent studies have implicated acetylation of several nuclear proteins such as histones and p53 on their epsilon-portion of lysine residues in eukaryotic transcription. Here we raised a specific polyclonal antibody against epsilon-acetylated lysine. Using the antibody, we detected hypernuclear acetylation (HNA) in atherosclerotic vascular smooth muscle cells (VSMCs). Thrombin, a humoral factor known to cause activation and proliferation of VSMCs, strongly potentiated HNA in cultured VSMCs. MAP kinase pathway and a signal coactivator CREB binding protein (CBP) were involved in thrombin-induced HNA of VSMCs. Our results suggest that coactivators cooperating with signal-dependent transcription activators play an important role in atherosclerogenesis via HNA in VSMCs.

Acetylation↗
PubMed1999

Topoisomerase-I activity and response to second-line chemotherapy consisting of camptothecin-11 and cisplatin in patients with ovarian cancer.

The aim of the present study was to clarify the relationship between topoisomerase-I (topo-I) activity and sensitivity to second-line chemotherapy consisting of cisplatin and camptothecin-11 (CPT-11) in patients with ovarian cancer. Thirty Japanese women with relapsed epithelial ovarian cancer who received treatment at Tottori University Hospital or Kurume University Hospital between 1992 and 1997 were included in this study. All patients had initially undergone chemotherapy consisting of cisplatin, doxorubicin and cyclophosphamide (CAP). All subjects exhibited measurable lesions and received second-line chemotherapy consisting of 50 to 60 mg/m(2) CPT-11 on days 1, 8 and 15 and 60 mg/m(2) cisplatin on day 1. Tumor samples were obtained in the period between initial and second-line chemotherapy. Topo-I activity was assayed by relaxation of supercoiled plasmid substrate DNA. Of the 30 patients, 18 responded to second-line chemotherapy and 12 did not. We found no significant difference in patient characteristics in responders and non-responders. The interval from the end of the initial course of chemotherapy to the beginning of the second-line chemotherapy did not significantly differ in the 2 groups. The minimum amount of extraction showing complete DNA relaxation in non-responders was significantly greater than that in responders (201.7 +/- 92.5 vs. 124.1 +/- 59.4 ng; p = 0.0164). In 8 cases whose samples could be obtained before and after CAP, the amount of protein significantly decreased after CAP therapy (286.4 +/- 142.1 vs. 138.5 +/- 97.8 ng; p = 0.0294). Topo-I activity, which is enhanced by CAP therapy, can play an important role in sensitivity to CPT-11.

Adult↗
PubMed1999

CRM1 mediates nuclear export of nonstructural protein 2 from parvovirus minute virus of mice.

The nonstructural protein 2 (NS2) from parvovirus minute virus of mice (MVMp) is a 25-kDa polypeptide which localizes preferentially to the cytoplasm and associates with cellular proteins in cytoplasm. These lines of evidence suggest that NS2 is positively exported from the nucleus to cytoplasm and functions in cytoplasm. We report here that nuclear export of NS2 is inhibited by leptomycin B (LMB), a drug that specifically blocks nuclear export signal (NES)-chromosomal region maintenance 1 (CRM1) interactions. CRM1 binds specifically to the 81- to 106-amino-acid (aa) region of NS2, and the region of NS2 actually functions as a NES. Interestingly, this region appears to be distinct from a typical NES sequence, which consists of leucine-rich sequences. These results indicate that NS2 protein is continuously exported from the nucleus by a CRM1-dependent mechanism and suggest that CRM1 also exports to distinct type of NESs.

Amino Acid Sequence↗