Search PubMed⌕ Search

Biomedical subjects

H Kuroda

Publications and source records attributed to H Kuroda.

At least 127 records · Page 7Linked to original sources
PubMed1997

Quantitative assays for hepatitis C virus in serum as predictors of the long-term response to interferon.

BACKGROUND/AIMS: Interferon therapy has a beneficial effect in patients with chronic hepatitis C who have a low viral load. The aim of this study was to compare the core protein level with HCV RNA levels and to analyze whether virus quantitation predicts the efficacy of interferon therapy. METHODS: HCV core protein level assessed by the recently developed assay was compared with HCV RNA levels measured by three different methods (Amplicor-HCV monitor, competitive RT(CRT)-PCR, and bDNA probe assay) in 352 patients with chronic hepatitis C in relation to viral serotype. RESULTS: From 91% (320/352) to 93% (299/322) of patients with viremia were detected by Amplicor-monitor and CRT-PCR, in contrast to 60% (187/312) and 74% (191/258) by bDNA and HCV core protein assay, respectively. The HCV core protein level was positively correlated with HCV RNA levels measured by the three assays (r = 0.680 to 0.731). Serum HCV RNA and core protein levels were significantly lower in patients with serotype 2 than in those with serotype 1. Viral eradication after interferon therapy was observed in 60-70% of the patients with < 1 x 10(4) copies/ml of HCV RNA by Amplicor-monitor assay, < 2 x 10(5) copies/ml by CRT-PCR, < 0.5 Meq/ml by bDNA assay, and < 20 pg/ml of core protein by HCV core protein assay. Viral eradication was uncommon (< 11%) among the patients with higher viral loads. Bivariate analysis revealed that the outcome of interferon therapy was more closely associated with both HCV core protein and RNA levels than the HCV serotype. CONCLUSIONS: Quantitation of HCV core protein and HCV RNA in useful for prediction of the interferon response.

Adolescent↗
PubMed1997

Long-term survival and differentiation of human peripheral blood CD34+ cells in SCID mice.

Human peripheral blood progenitor cells (PBPC) are currently used as a source of hematopoietic reconstitution by autologous transplantation after myeloabrative chemotherapy for malignancies. PBPC would also be useful for allogeneic transplantation since the collection of PBPC is much safer than that of bone marrow stem cells (BM). For allogeneic transplantation, it is imperative to confirm that PBPC contains self-renewable stem cells that can sustain a long lasting hematopoiesis. In the present study, we examined the reconstitution of human hematopoiesis in severe combined immunodeficiency (SCID) mice by transplanting peripheral blood CD34+ cells in which the neo gene was transduced as a marker. In 2 of 4 mice receiving PB-CD34+ cell transplantation, the neo gene appeared as early as 4 weeks and lasted as long as 24 weeks in all DNA preparations of bone marrow, peripheral blood and spleen cells from the SCID mice, while in 2 of 4 mice receiving BM-CD34+ cell transplantation, although the neo gene also lasted as late as 24 weeks, it did not appear as early as in the mice receiving PB-CD34+ cell transplantation. A similar observation was noted in clinical trials, i.e. the white blood cell and platelet recovered earlier by transplantation of PBPC than of BM. In mice who had the neo gene, we were also able to demonstrate by FACS the presence of human lineage specific antigen in the cells as late as 24 weeks after transplantation with PB-CD34+ cells, and the presence of human IgG in the sera 10 weeks after transplantation. These findings indicate that PB-CD34+ cells contain long-term repopulating stem cells which undergo differentiation in SCID mice.

Animals↗
PubMed1997

Messenger ribonucleic acid expression of LH/hCG receptor gene in human ovarian carcinomas.

The mRNA expression of luteinizing hormone (LH)/human chorionic gonadotropin (hCG) receptors was analysed by the RT-nested PCR method in five normal ovarian tissues, 62 ovarian tumours (5 benign, 7 borderline and 43 malignant epithelial tumours, 3 sex cord-stromal tumours and 4 germ cell tumours) and in 2 ovarian cancer cell lines. In normal ovaries, two cDNA fragments of different sizes were detected using primers designed to amplify a region including exon 9. Sequencing revealed that the larger fragment was derived from a full-length receptor, while the smaller fragment was a splice variant lacking exon 9. In ovarian tumours, the larger fragment of LH/hCG receptors was detected in 40% of the epithelial ovarian carcinomas, none of the germ cell tumours, all of the sex cord-stromal tumours and one of the 2 ovarian cancer cell lines. Immunohistochemistry confirmed the localisation of LH/hCG receptor protein in the tumour cells which correlated with mRNA expression. Patients with full-length LH/hCG receptors in carcinomas showed a better prognosis compared with those without the receptors.

Biomarkers, Tumor↗
PubMed1997

STAM, signal transducing adaptor molecule, is associated with Janus kinases and involved in signaling for cell growth and c-myc induction.

We previously identified a putative signal transducing adaptor molecule, named STAM, that contains an Src homology 3 (SH3) domain and immunoreceptor tyrosine-based activation motif (ITAM). In this report, we demonstrate the functional significance of STAM in cytokine-mediated signal transduction. STAM is associated with Jak3 and Jak2 tyrosine kinases via its ITAM region and phosphorylated by Jak3 and Jak2 upon stimulation with IL-2 and GM-CSF, respectively. An SH3 deletion mutant of STAM confers a dominant-negative effect on DNA synthesis mediated by IL-2 and GM-CSF. Furthermore, the wild-type STAM, but not STAM mutants deleted of SH3 and ITAM, significantly enhances c-myc induction mediated by IL-2 and GM-CSF. These results strongly implicate STAM in the signaling pathways for cell growth and c-myc induction immediately downstream of the Jaks associated with the cytokine receptors.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Expression of vascular endothelial growth factor (VEGF) in epithelial ovarian neoplasms: correlation with clinicopathology and patient survival, and analysis of serum VEGF levels.

Vascular endothelial growth factor (VEGF) is known to be produced by various solid tumours and is thought to be involved in microvascular permeability and/or angiogenesis. To examine the relationship between VEGF expression in ovarian neoplasms and clinicopathological factors or patient survival, expression of VEGF was analysed immunohistochemically in 110 epithelial ovarian tumours. In addition, VEGF levels in the tumour fluid (17 patients), ascites (12 patients) and sera (38 patients) were determined using enzyme immunoassay. Positive immunostaining for VEGF was observed in 97% (68 out of 70) of ovarian carcinomas, which was significantly higher than that of tumours of low malignant potential (LMP) (13 out of 25; 52%) and benign cystadenomas (5 out of 15; 33%) (P < 0.01). In ovarian carcinomas, strong VEGF immunostaining was also observed more frequently in tumours of clear cell type (P < 0.05) in the advanced stage of disease (P < 0.05) and with positive peritoneal cytology (P < 0.01). Patients with strong VEGF staining had poorer survival rates than those with weak or no immunostaining for VEGF (P < 0.01). These findings suggest that strong VEGF expression plays an important role in the tumour progression of ovarian carcinoma. The enzyme immunoassay revealed higher serum VEGF levels in carcinoma patients than those in patients with LMP or benign tumours (P < 0.01). Serum VEGF levels decreased after the successful removal of tumours in ovarian cancer patients and, in one patient, the serum VEGF level was re-elevated during relapse. Therefore, serum VEGF could be used as a marker for monitoring the clinical course of ovarian cancer patients.

Adult↗
PubMed1997

Predictors of the efficacy of interferon therapy in chronic hepatitis C virus infection. Tokyo-Chiba Hepatitis Research Group.

BACKGROUND & AIMS: The relative role of virus load and hepatitis C virus (HCV) subtype as predictor of the efficacy of interferon (IFN) therapy is still in dispute. To resolve this issue, a multicenter, randomized, prospective study of 272 patients with chronic hepatitis C but without cirrhosis was conducted. METHODS: The patients were randomly assigned to two different dose groups: 6 million units (MU) or 9 MU IFN three times a week for 6 months. Serum HCV RNA levels and HCV subtypes were determined. RESULTS: HCV RNA negativity rate at the completion of treatment with 9 MU IFN was higher than that with 6 MU (75% vs. 44%; P < 0.05). Virus eradication at 12 months after completion of treatment was higher in the 9 MU group than in the 6 MU group (36% vs. 25%; P < 0.05), especially in patients who had an intermediate virus load (10(4)-10(5) copies/mL by Amplicor monitor assay) (52% vs. 19%; P = 0.029). Virus eradication rate in patients with serotype 2 was higher than in those with serotype 1 for both regimens (6 MU, 53% vs. 15%; 9 MU, 76% vs. 29%; each P < 0.05). CONCLUSIONS: This prospective study showed that virus load, HCV serotype, and IFN dose are important predictors of the virological response to IFN therapy but virus load is the most important factor influencing the efficacy of IFN.

Adult↗
PubMed1997

Computed tomographic study of aged schizophrenic patients.

The width of interhemispheric fissure, lateral ventricles and third ventricle were measured using cranial computed tomography (CT; linear method) in 45 elderly inpatients with chronic schizophrenia and in 28 age-matched control subjects. Twenty-three patients were men and 22 were women. In addition, Mini-Mental State Examination, Brief Psychiatric Rating Scale (BPRS) and a subclass of BPRS were undertaken in all patients. There is a significant enlargement of the maximum width of the interhemispheric fissure (in both male and female) and a significant enlargement of the ventricular system (more severe in men than in women) in aged schizophrenics, as seen with CT, compared with normal controls. These findings are consistent with previous studies of non-aged schizophrenic patients. Based upon the relation between the third ventricle enlargement and the positive and depressive symptoms in all patients. This result suggests that the advanced third ventricle enlargement may decrease these symptoms in aged schizophrenics.

Aged↗
PubMed1997

Involvement of protein kinase A in the subjective nocturnal rise of melatonin release by chick pineal cells in constant darkness.

Melatonin release by chick cultured pineal cells increases during the dark periods and decreases during the light periods under light-dark cycles, and this rhythmic secretion is maintained under constant conditions with a period of almost 24 hr. The mechanisms by which the circadian oscillator drives the melatonin rhythm under constant conditions have not been elucidated enough. We examined the possibility that cyclic AMP-dependent protein kinase A is involved in the subjective nocturnal increase in melatonin release by chick pineal cells cultured under constant darkness. The subjective nocturnal increase of melatonin release was suppressed dose dependently by H8 (protein kinase inhibitor) and H89 (specific protein kinase A inhibitor), but not by calphostin C (specific protein kinase C inhibitor) in static cell cultures. In a cell perfusion experiment, 9 hr pulses of H8 and H89 starting at ZT 9 (CT 11.2) hr suppressed the subjective nocturnal increase in melatonin rhythm in dose-dependent manner without causing a phase shift. An intracellular Ca2+ chelator, O,O'-bis(2-aminophenoxy)ethyleneglycol-N,N,N',N'-tetraacetic acid tetraacetoxymethyl ester (BAPTA-AM), and extracellular Ca2+ chelators, O,O'-bis(2-aminophenoxy)ethyleneglycol-N,N,N',N'-tetraacetic acid tetrapotassium salt hydrate (BAPTA) and ethyleneglycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA), suppressed both the subjective nocturnal increases in melatonin release and cAMP levels dose dependently. This direct evidence strongly supports the hypothesis that cAMP-dependent protein kinase A may be involved in the subjective nocturnal increase in melatonin release by chick pineal cells and that intracellular Ca2+ plays an important role in pineal adenylate cyclase activation.

Animals↗
PubMed1997

Transient expression of goat growth hormone gene in poplar (Populus alba L.) protoplasts: a quick method for detection of foreign gene expression in mRNA level.

We developed a sensitive, accurate, and fast method to detect foreign gene expression using reverse transcriptase-mediated polymerase chain reaction (RT-PCR) in poplar tree (Populus alba L.) protoplasts. Template total RNA was purified by removing the transfected foreign gene vector completely with DNase I treatment before the RT reaction. Expression of cDNA that encodes goat growth hormone was confirmed at the mRNA level 24 h after electroporation mediated DNA transfer.

Animals↗
PubMed1997

Immunohistochemical localization of basic fibroblast growth factor (bFGF) during folliculogenesis in the human ovary.

Basic fibroblast growth factor (bFGF) has been suggested to be one of the intraovarian regulators of ovarian folliculogenesis, but its localization in the human ovary remains to be determined. We examined the immunohistochemical reactivity for bFGF in the course of follicular development and corpora lutea formation in the human ovary. Pregranulosa cells in the primordial follicle were negative, but at the preantral stage both granulosa and theca cells showed weakly positive immunostaining for bFGF. In the antral follicles, both granulosa and theca interna cells showed stronger staining for bFGF with the increase in follicular diameter. In atretic follicles at various stages, granulosa cells were negative or weakly positive for bFGF, whereas luteinized theca cells showed strong immunoreactivity. In the corpora lutea during the early luteal phase, granulosa lutein cells were strongly positive for bFGF but in the late luteal phase became immunonegative. On the other hand, bFGF staining in theca lutein cells was strong throughout the course of corpora lutea formation and regression. These findings suggest that bFGF is localized not only in granulosa cells but also in theca cells, and in the latter, bFGF immunoreactivity is associated with luteinization.

Adult↗
PubMed1997

Expression of vascular endothelial growth factor (VEGF) during folliculogenesis and corpus luteum formation in the human ovary.

Vascular endothelial growth factor (VEGF) has been suggested to be involved in angiogenesis and microvascular hyperpermeability. We examined immunohistochemically the expression of VEGF in the granulosa and theca cells, along with that of proliferating cell nuclear antigen (PCNA), in the vascular endothelium during the course of follicular development and corpora lutea formation in human ovaries. The immunolocalization of VEGF in these cells was compared with that of another putative angiogenic factor, basic fibroblast growth factor (bFGF). The granulosa cells in the primordial and primary follicles were VEGF negative, but at the preantral stage, the granulosa cells showed weakly positive immunostaining for VEGF. However, the VEGF immunostaining in the granulosa cells was weak throughout the folliculogenesis. In contrast, the theca interna cells of developing follicles showed strong staining for VEGF, which was well correlated with the PCNA positivity in the vascular endothelial cells in the thecal layer. In the atretic follicles, the granulosa and theca cells were VEGF negative. In the corpora lutea, VEGF was strongly expressed in both granulosa and theca lutein cells in the early luteal phase when the PCNA positivity in the endothelium increased, but the VEGF staining in these cells became weak in the mid- and late luteal phases. Accordingly, the PCNA positivity in the vascular endothelium was well correlated with the expression of VEGF in the theca cells during follicular development and atresia, and that in the granulosa and theca lutein cells in corpora lutea formation and regression. In addition, the immunolocalization of VEGF was different from that of bFGF.

Biopsy↗
PubMed1997

[Surgical treatment of aortic valve regurgitation due to nonpenetrating trauma of the chest--a case report and review of the literature in Japan].

A case report and a literature review of the patients in Japan who underwent surgical treatment of an aortic valve regurgitation due to nonpenetrating chest trauma are presented. A 70-year-old man was admitted to our hospital with multiple trauma, including fracture of sternum, caused by traffic accident. After treatment of respiratory and circulatory failure, he was found to have aortic regurgitation and subsequent congestive heart failure. The aortic valve replacement was performed and his postoperative course was good. The tear of aortic valve was detected in the noncoronary cusp, and the size of the tear was 4 mm. The aortic valve was not recognized the findings of inflammatory or rheumatic changes. Before this case, 15 cases were operated in Japan with the diagnosis of traumatic aortic regurgitation. We reviewed them in the table.

Accidents, Traffic↗
PubMed1997

Immunostaining of PRAD1/cyclin D1 protein as a marker for the diagnosis of mantle cell lymphoma.

The overexpression of PRAD1/cyclin D1 gene activated by the 11q13 translocation and its molecular counterpart BCL-1 rearrangement is frequently associated with mantle cell lymphomas (MCLs). Recently, we produced a monoclonal antibody, 5D4, against the PRAD1/cyclin D1 product, and demonstrated that the positive nuclear staining by this antibody correlates with PRAD1/cyclin D1 mRNA overexpression in MCLs. In the present study, we have immunohistochemically examined the cyclin D1 protein in a large series of 315 malignant lymphomas including 39 MCLs on paraffin sections. The nuclear positive pattern was found in 35 (90%) of 39 MCLs with an exceptional case of immunocytoma among the B-cell lymphomas examined. In the other cases, the positivity was absent or appeared to lie within the cytoplasm without nuclear staining. We therefore propose that the immunolocalization of cyclin D1 protein is an essential marker for the definite diagnosis of MCL.

Biomarkers, Tumor↗
PubMed1997

[A case of a successfully treated subclavian aneurysm complicated by a brachiocephalic aneurysm, and the left vertebral artery occlusion].

The patient was a 67-year-old male. Preoperative DSA study revealed a right subclavian aneurysm, a brachiocephalic aneurysm, stenosis of the left common carotid artery and the left subclavian artery, and occlusion of the left vertebral artery. An intraoperative occlusion test of the right vertebral artery showed a decline of the brainstem auditory evoked responses (BAER) seven minutes after the start of the procedure. Cardiopulmonary bypass was established by femoral arterial and bicaval cannulation. Under selective cerebral perfusion by cannulation of both common caroid arteries, a partial aortic arch replacement was performed using a graft patch with 3 branches. These three branches were connected to the right subclavian artery and to both common carotid arteries, respectively. Under deep hypothermia the right vertebral artery was reconstructed with the saphenous vein graft. Proximal anastomosis between the saphenous vein graft and the right caroid graft was done perfusion from a branch of the saphenous vein graft in order to shorten ischemic time of basilar arterial region. The patient was weaned from bypass without problems. After weaning the BAER test was again performed and found to be normal. The postoperative course was uneventful. Postoperative DSA examination showed good blood flow in all the reconstructed vessels. This study suggests that deep hypothermia and shortening of ischemic time of the basilar arterial region are effective in preventing ischemic injury of the brain stem and the cerebellum.

Aged↗
PubMed1997

[A randomized study on intravesical pirarubicin (THP) chemoprophylaxis of recurrence after transurethral resection of superficial bladder cancer].

A prospective randomized study was conducted to evaluate the efficacy of prophylactic intravesical instillation of tetrahydropyranyladriamycin (THP) following complete transurethral resection (TUR) of superficial bladder cancer. A total of 80 patients were randomized into "THP" or "control" group. In the THP group, 20 mg of THP dissolved in 40 ml saline (or 5% dextrose) was administered intravesically once a week for 10 weeks, starting from about 7 days after TUR. In the control group, 40 ml saline was given with the same schedule. The patients were followed up by cystoscopy and urinary cytology every 3 months. The number of evaluable patients was 36 for the THP group and 37 for the control group. The non-recurrence rates in the THP group and control group were 79.4% versus 63.2% at 1 year and 69.8% versus 47.4% at 3 to 5 years, respectively. These figures were not statistically significant. However, THP instillation significantly reduced tumor recurrence rates for multiple tumors, and also tended to decrease recurrence rates for primary and pT1 tumors. Adverse effects were observed in 53.6% of the patients in the THP group, but they were tolerable. Our results suggest that intravesical THP instillation would not be effective for all patients with superficial bladder cancer. Further study is warranted in a selected group of patients.

Administration, Intravesical↗
PubMed1996

Physical mapping of the DDX1 gene to 340 kb 5' of MYCN.

One of the most important prognostic factors in neuroblastoma is amplification of the MYCN gene, which is strongly associated with advanced stages of disease and a poor prognosis. Although the MYCN amplicon sometimes spans more than 1 Mb, no other consistently expressed sequences from the MYCN amplicon have been reported. However, DDX1, a gene encoding a DEAD box protein, was recently mapped to chromosome 2p24 and is frequently co-amplified with MYCN. Therefore, we performed genomic mapping with YACs to determine the physical relationship between DDX1 and MYCN, and whether DDX1 was contained within the core region of amplification. Based on YAC restriction mapping and content analysis, DDX1 maps 340 kb 5' of MYCN, outside the core domain of consistent amplification. Interestingly, we also determined by sequence analysis and detailed restriction mapping that G21, previously isolated as a 'neuroblastoma-specific' cDNA clone from an MYCN amplicon, is a partial cDNA of DDX1. Our data confirm that DDX1 is amplified in some but not all MYCN-amplified tumors, and that it is rearranged in other cases. This suggests that the co-amplification of DDX1 is due to its proximity to MYCN.

Chromosome Mapping↗
PubMed1996

Cloning of a novel signal-transducing adaptor molecule containing an SH3 domain and ITAM.

We molecularly cloned a cDNA coding for a novel phosphotyrosine molecule with a 70 kDa molecular mass, named STAM (signal transducing adaptor molecule), which is tyrosine-phosphorylated rapidly after stimulation with various cytokines such as IL-2, IL-3, IL-4, IL-7, GM-CSF, EGF and PDGF. STAM contains an SH3 (Src-homology 3) domain and the ITAM (immunoreceptor tyrosine-based activation motif), suggesting that STAM acts as an adaptor molecule involved in signal transducing pathways from the cytokine receptors.

Adaptor Proteins, Signal Transducing↗