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Biomedical subjects

T Okuno

Publications and source records attributed to T Okuno.

At least 109 records · Page 6Linked to original sources
PubMed1997

[Neuroimagings in neuronal migration disorders].

Recent progress in magnetic resonance imaging (MRI) has successfully visualized neuronal migration disorders (NMDs) without autopsy. NMDs are observed in the patients with hydranencephaly, porencephaly, cerebellar hypoplasia, agenesis of corpus callosum, agenesis of septum pellucidum and holoprocencephaly. Miller-Dieker syndrome, Fukuyama-type congenital muscular dystrophy, Walker-Warburg syndrome, hypomelanosis of Ito, congenital rubella syndrome, toxoplasmosis, Zellweger syndrome and other diseases are also associated with lissencephaly, pachygyria and polymicrogyria. Neuroimagings of illustrative cases with NMDs were shown here.

Adolescent↗
PubMed1997

[Clinical statistics of living and cadaveric renal transplantation at the Department of Urology, Mie University School of Medicine].

A statistic survey was made on the clinical results of living and cadaveric renal transplantations performed at our department between October 1980 and June 1996. A total of 38 patients received 6 living and 32 cadaveric renal transplants. The graft and patient survival rates of a living renal transplantation were 83.3% and 100% at 3 years, respectively. The graft survival rate of cadaveric renal transplantation was 66.3% at 3 years and 56.0% at 5 years. In a cadaveric renal transplantation, patients with episodes of acute rejection within 12 months showed a significantly worse graft survival rate. This clinical parameter seems to be a prognostic factor for a long-term graft survival.

Adolescent↗
PubMed1997

[Bladder cancer associated with von Recklinghausen's disease: a case report].

A 53-year-old man was admitted to our hospital with urinary frequency and miction pain. He had von Recklinghausen's disease with multiple café-au-lait spots and neurofibromatosis. Computed tomography scan and magnetic resonance imaging revealed an invasive bladder tumor 10 cm in diameter, and not metastasis. He was diagnosed as having a bladder tumor (T3a N0 M0 with von Recklinghausen's disease. After balloon occluded arterial infusion (BOAI) chemotherapy, total cystectomy was performed. Pathological diagnosis was transitional cell carcinoma, G3, pT3aN0M0. We reviewed and discussed 97 cases of carcinoma associated with von Recklinghausen's disease reported in the Japanese literature. Only 5 cases of bladder cancer have been reported, including the present case.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

A single codon change in a conserved motif of a bromovirus movement protein gene confers compatibility with a new host.

Brome mosaic virus (BMV) and cowpea chlorotic mottle virus (CCMV) are closely related bromoviruses with tripartite RNA genomes, but distinct host ranges: BMV systemically infects the monocot barley, while CCMV systemically infects the dicot cowpea. We have previously shown that in approximately 10% of inoculated cowpea plants, a CCMV hybrid [CCMV(B3a)] with the 3a cell-to-cell movement protein gene replaced by that of cowpea-nonadapted BMV directs systemic infections, which are caused by secondary mutation(s) of the hybrid virus. Here, to further analyze the role of RNA3 in adaptation to a new host, RNA3 cDNA clones were constructed from total RNA recovered from the uninoculated upper leaves of systemically infected cowpea plants inoculated with CCMV(B3a). Sequence and mutational analysis of two such RNA3 clones revealed that a single codon change (A776-->C) in a conserved motif of the 3a movement protein gene conferred compatibility for systemic infection of a new host, cowpea, suggesting that this site in the 3a gene is directly or indirectly involved in crucial host interactions associated with host-range specificity. The adaptive hybrid viruses carrying this mutation induced exacerbated symptoms, while wt CCMV appeared nearly symptomless, showing that the bromovirus 3a movement protein gene can significantly contribute to regulating symptom development. However, introducing this cowpea-adaptive mutation into the BMV genome had little effect on the ability of BMV to systemically infect barley.

Base Sequence↗
PubMed1996

Identification of a variant A-specific neutralizing epitope on glycoprotein B (gB) of human herpesvirus-6 (HHV-6).

Based on genetic, antigenic, and growth properties, human herpesvirus-6 (HHV-6) can be classified into two groups, variant A (HHV-6A) and variant B (HHV-6B). We have mapped the HHV-6A-specific epitope on glycoprotein B (gB), which was recognized by a monoclonal antibody (MAb), 87-y-13, with a complement-independent neutralizing activity. Plasmids carrying various chimeric gB sequences formed between strains U1102 (HHV-6A) and HST (HHV-6B) and carrying sequences for a series of carboxy-terminal deletions of U1102 gB were constructed. By using the plasmids, in vitro transcription and subsequent in vitro translation were carried out. Immunoprecipitation assay of the translated products with MAb 87-y-13 revealed that MAb 87-y-13 was able to react only with in vitro translation products containing the sequence between amino acid residues 335 and 395 of U1102 gB. Amino acid sequence comparison between HHV-6A and HHV-6B in this region showed that amino acid residues 347, 387, and 393-395 were HHV-6A-specific. To determine which amino acid residue(s) was involved in recognition by MAb 87-y-13 as well as in the neutralizing activity, point mutations were introduced at those amino acid positions. Immunoprecipitation assay of the mutagenized gB with point mutations suggested that the neutralizing MAb-y-13 was involved in the recognition of the amino acid Asn at residue 347 of U1102 gB (HHV-6A). This site may play an important role in viral infection.

Amino Acid Sequence↗
PubMed1996

Neuro-otological findings after radiosurgery for acoustic neurinomas.

OBJECTIVE: To evaluate the neuro-otological complications in patients after radiosurgery for acoustic neurinomas. DESIGN: Inception cohort, retrospective study. SETTING: University hospital. PATIENTS: A consecutive sample of 46 patients with acoustic neurinomas who underwent unilateral gamma knife radiosurgery at the University of Tokyo, Japan, between June 1990 and June 1994 were followed up by otolaryngologists for more than 3 months. INTERVENTION: Gamma knife stereotactic radiosurgery. MAIN OUTCOME MEASURES: Neuro-otological examinations including pure tone audiometry, auditory brain stem response, and caloric test. RESULTS: Tumor growth occurred in 2 patients (4.3%). Seven (18%) of the 38 patients with preserved hearing of any extent became deaf within 1 year. In cases of gradual hearing loss, the average deterioration rate was approximately 8 dB per year. Abnormalities of auditory brain stem response preceded deafness in 2 patients. Caloric response, preserved before treatment in 13 patients, disappeared 4 to 13 months after treatment (median, 8 months) in 9 (69%) of them, whereas their hearing was preserved. Delayed facial palsy and persistent trigeminal neuropathy occurred in 10 (22%) and 7 (15%) of the 46 patients, respectively. Severe facial palsy tended to persist. CONCLUSIONS: The rates of neuro-otological complications of radiosurgery are almost comparable with those previously reported from other institutions. The deafness within 1 year after treatment might be attributed to a lesion in the cochlear nerve. Hearing loss did not parallel vestibular function loss. The persistent severe facial palsy contrasts with previously reported findings. Considering the serious facial nerve complications that occurred in some of our patients, further study to disclose the risk factors for neurological dysfunction would be needed for radiosurgery to become a true, safe alternative to microsurgery.

Adolescent↗
PubMed1996

Identification and metabolism of selenocysteine-glutathione selenenyl sulfide (CySeSG) in small intestine of mice orally exposed to selenocystine.

This investigation was carried out to elucidate the chemical form of selenium-containing metabolite in small intestine of ICR male mice orally administered selenocystine (CySeSeCy). The metabolite in intestinal cytosol of mice treated with CySeSeCy (50 mg/kg) was identified as selenocysteine-glutathione selenenyl sulfide (CySeSG) by high performance liquid chromatography using a gel filtration and reversed phase column. Hydrogen selenide formation was caused as a result of the anaerobic reaction between the CySeSG and liver cytosol containing selenocysteine beta-lyase, which specifically acts on selenocysteine (CySeH). Effects of GSH or glutathione reductase on hydrogen selenide formation from CyseSG reacted with the liver cytosol were examined. The CySeSG was nonenzymatically reduced to CySeH by excess GSH in the liver cytosol. It was also recognized that CySeSG was enzymatically reduced to CySeH by glutathione reductase in the presence of NADPH. These results indicate that the chemical form of this metabolite is CySeSG, which has a molecular weight of 473, the CySeSG is then reduced by excess GSH and/or glutathione reductase yielding CySeH, which is decomposed by selenocysteine beta-lyase to hydrogen selenide. CySeSG may be a stable precursor of hydrogen selenide in animals.

Administration, Oral↗
PubMed1996

The clinical significance of changes in genetic heterogeneity of the hypervariable region 1 in chronic hepatitis C with interferon therapy.

We examined changes in the hypervariable region 1 of the hepatitis C virus (HCV) RNA that occurred with interferon therapy in 33 patients with chronic hepatitis C to assess the clinical significance of this region. The 33 patients had HCV genotype 1b and were classified into three groups based on serum aminotransferase levels during and after therapy with alpha interferon; long-term responders (n = 9), short-term responders (n = 11), and nonresponders (n = 13). Changes in the genetic heterogeneity of the hypervariable region 1 were determined by using nonisotopic polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). HCV RNA levels were evaluated by reverse transcriptase PCR and branched DNA probe assays. Changes in sequences were determined by cloning and sequencing analysis. Before therapy, the long-term responders had significantly lower degrees of heterogeneity and lower viral levels than nonresponders. There were no significant differences between short-term and nonresponders. With interferon therapy, viral levels and degree of heterogeneity decreased to a greater extent among long-term and short-term responders than among nonresponders. Sequencing analysis showed that the three groups had similar clone numbers initially, but long-term responders had rather homogeneous viral populations, whereas short-term and nonresponders had heterogeneous populations, but that there were no nucleotide sequences or amino acid alignments that were specific for any group before, during, and 6 months after therapy. Approximately half of short-term and nonresponders received a second course of interferon 7 to 10 months after the initial therapy; all showed an identical response to the second course of therapy regardless of interim changes in the heterogeneity of hypervariable region 1. These findings suggest that (1) patients who were nonresponders or short-term responders had mixed viral populations that had differing sensitivities to interferon, (2) the changes in the hypervariable region 1 (HVR 1) did not affect responsiveness to interferon, and (3) the lower heterogeneity in the HVR 1 was associated with a long-term response to interferon only when the viral levels were low.

Chronic Disease↗
PubMed1996

Lack of effect of vancomycin and gentamicin on auditory function in guinea pigs.

The dispositions of vancomycin (VCM) and gentamicin (GM) in plasma and perilymph after single and multiple administrations and the effects of multiple administrations of VCM or GM alone and the combination of both drugs on auditory function were studied in male guinea pigs. The pharmacokinetic parameters of VCM and GM obtained from plasma drug concentration-time data after single and multiple (22 days) intramuscular administrations of VCM (200 mg/kg of body weight) alone and GM (50 mg/kg) alone were not significantly different from those after combined administration of VCM (200 mg/kg) and GM (50 mg/kg). There was no change in the penetration ratio of VCM and GM into perilymph between administration of VCM or GM alone and the combination of both drugs. Furthermore, the hearing threshold of guinea pigs was not affected by VCM or GM alone or the combination of both drugs within the range of therapeutic VCM and GM levels in plasma in humans.

Animals↗
PubMed1996

Nephropathy and growth hormone deficiency in a patient with mitochondrial tRNA(Leu(UUR)) mutation.

A mitochondrial A 3243 G mutation in the tRNA(Leu(UUR)) gene was first described as a common cause of MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like syndrome). This same mutation is also the cause of a totally different disorder, a subtype of diabetes mellitus which is inherited maternally and often associated with sensorineural hearing loss. In this paper, we report on a Japanese boy with A 3243 G who developed a previously undescribed combination of symptoms, nephropathy and growth hormone deficiency. The patient first presented with short stature and moderate mental retardation. Growth hormone (GH) provocation tests showed deficient growth hormone secretion. During the course of follow up, he presented with progressive nephropathy followed by the development of diabetes mellitus. The results of laboratory tests and renal biopsy were against incidental association of known types of nephropathy. On PCR-RFLP analysis, the percentage of mutated mtDNA was higher in the renal biopsy specimen than 12 peripheral blood leucocytes. Our case suggests that mitochondrial diseases should be taken into account when there is nephropathy of unknown cause. In addition, the presence of growth hormone deficiency may account for part of the mechanism leading to short stature commonly seen in these patients.

Blotting, Southern↗
PubMed1996

A 100 mT-class ELF magnetic field exposure system for cultured cells.

We developed a system for exposure of cultured cells to extremely low frequency (ELF) magnetic fields much stronger than those used in previous in vitro studies. The system consists of an electromagnet, a commercial incubator with a custom-designed door and a custom-designed shelf, and other components, and exposes cells in the incubator to ELF magnetic field. We confirmed that it has good performance characteristics in terms of field intensity, field uniformity, waveform, field stability, temperature uniformity, and temperature stability. Its features include: (1) strong ELF magnetic fields (at most, 170 mTRMS), (2) long-term exposure (at least, 5.5 h), and (3) variable frequencies (10-100 Hz). This exposure system is expected to contribute significantly to research on possible hazards of ELF magnetic fields.

Cells, Cultured↗
PubMed1996

[A case of secondary leukemia in anaplastic seminoma patient treated with long-term chemotherapy].

A 46-year-old man had received a long-term induction plus salvage chemotherapy for anaplastic seminoma with stage IV disease. Chemotherapy regimens and cycles included the following; four cycles of bleomycin plus vinblastine plus cisplatin (BVP); eight cycles of cyclophosphamide, vincristine, and cisplatin (COP); three cycles of etoposide plus cisplatin (EP); thirteen cycles of etoposide with ifosfamide and cisplatin (VIP). The total cumulative dose of etoposide was 4250 mg/m2. Severe and persistent pancytopenia developed 32 months after starting etoposide-based salvage chemotherapy. Bone marrow examination showed hypercellular marrow containing 68% myeloblasts but peroxidase reaction was negative. CD-13 was 30.1% which meant that leukemia was myelogenous. Therefore, he was diagnosed as acute myelogenous leukemia. French-American-British classification was MO. Chromosome analysis revealed a t (8; 21)(q22;q22) cytogenetic abnormality. This case may be compatible with the clinical and cytogenetic characters of epipodophyllotoxin-related leukemia. We conclude that high doses of etoposide seem to be leukemogenic. To our knowledge, this is the first reported case in the literature relevant to epipodophyllotoxin-related secondary leukemia in testicular tomor in Japan.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

[Prognostic factors of renal cell carcinoma: a multivariate analysis].

In a series of 104 patients with renal cell carcinoma, a variety of clinical and histological factors were analyzed to establish their value as prognostic factors. In a univariate analysis (log-rank test), the presence or absence of symptoms, tumor size, pT, N, M, pV categories, TNM stage, Robson stage, nuclear grade and cell type were significantly associated with cause-specific survival, while age, sex and tumor side were not. In a multivariate analysis using Cox's proportional hazard model of 73 informative cases, only N (0 vs. 1-3) and M (0 vs. 1) categories of stage and nuclear grade (1-2 vs. 3) proved to be independent prognostic markers.

Aged↗
PubMed1996

[A clinical study of renal cell carcinoma with extension into the inferior vena cava].

Nineteen patients with renal cell carcinoma with tumor extension into the inferior vena cava (IVC) were investigated between January, 1973 and March, 1994. The patients were between 50 and 78 years old with a mean of 65.9 years. The male to female ratio was 1.7 to 1. Thirteen tumors were on the right side and 6 on the left side. In 12 patients, both nephrectomy and removal of the tumor thrombus were performed. The survival rate in the operated group was 60% at 5 years. Histologically, 7 cases were diagnosed as clear cell subtype and 5 cases as granular cell subtype. From this study, an extended operative intervention such as radical nephrectomy combined with tumor thrombectomy of the IVC with or without cavectomy was suggested in the case of renal cell carcinoma without any other metastatic lesions and histopathologically of the clear cell subtype.

Aged↗
PubMed1996

[A case of gastric cancer with peritoneal dissemination and malignant biliary stenosis treated by loco-regional cancer therapy].

A 68-year-old male diagnosed as Borrmann 2 type gastric cancer (T3N3P3H0M0: Stage IVb) was treated by distal gastrectomy and administration of CDDP 50 mg+MMC 10 mg intraperitoneally. After operation intraperitoneal chemotherapy was continued until adhesional ileus occurred four months later. At reoperation peritoneal dissemination was not found either macroscopically or microscopically. After four months, and expandable metallic stent (Wallstent) was applied for malignant biliary stenosis due to lymph node metastasis. Although the patient died 23 months after the first operation, our loco-regional cancer therapy seemed effective for support of quality of life.

Aged↗