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Biomedical subjects

T Oshima

Publications and source records attributed to T Oshima.

At least 721 records · Page 40Linked to original sources

Establishment of a cell line from a woodchuck hepatocellular carcinoma.

A new cell line derived from a woodchuck hepatocellular carcinoma serially transplanted in athymic nude mice has been established and named WH257GE10. The original tumor in the nude mouse system produces woodchuck hepatitis surface antigen and albumin. In addition, woodchuck hepatitis virus DNA is integrated into cellular DNA. Adaptation of the cells to the in vitro culture condition was completed after 15 months with the doubling time of 40 hr. The morphologic features of the cell by light microscopy are of an epithelial type. The modal chromosome number is 36 and the karyotype is mainly metacentric, similar to that observed in normal woodchuck liver cells. Ornithine and tyrosine aminotransferase activities were detected. Production of albumin was demonstrated in the cytoplasm by indirect immunofluorescence. Integration of woodchuck hepatitis virus DNA was shown by Southern blot analysis, although the secretion of woodchuck hepatitis surface antigen was not detected. This cell line provides an excellent in vitro model to study human hepatocellular carcinoma related to hepatitis B virus.

Albumins↗

Prevalence of urinary tract infection during outpatient follow-up after renal transplantation.

Seven hundred and twenty-seven renal transplant patients are reviewed with respect to the occurrence of urinary tract infection (UTI) after renal transplantation. UTI was defined as the detection of both bacteriuria (10(5) CFU/ml) and pyuria (10 leukocytes/hpf). UTI developed in 11 of the inpatients (20.8%) and in 30 (4.2%) of the outpatients during a one-year period. Among outpatients, 12 had symptomatic infections, comprising seven with acute pyelonephritis and five with acute cystitis. Asymptomatic UTI was detected in 18 patients. In addition, asymptomatic bacteriuria without pyuria was observed in ten (1.4%) patients. UTI was more common in patients with diabetes, and underlying urinary tract complications were present in some patients. Administration of trimethoprim-sulfamethoxazole for about 4 months is suggested to reduce the frequency of UTI in the early period after renal transplantation.

Anti-Bacterial Agents↗

Mating-type differentiation by transposition of controlling elements in Saccharomyces cerevisiae.

The nonfunctional mutation of the homothallic gene HML alpha, designated hml alpha, produced two mutant alleles, hml alpha-1 and hml alpha-2. Both mutant clones were mixed cultures consisting of a mating-type cells and nonmating haploid cells. The frequencies of the two cell types were different, and a few diploid cells able to sporulate were found in the hml alpha-2 mutant. Conversions of an a mating-type cell to nonmater, and vice versa, were observed in both mutants. The conversion of an a mating phenotype to nonmating is postulated to occur by alteration of the a mating type to the sterile mating-type allele in the hml alpha-1 mutant. In tetrad dissection of prototrophic diploids that were obtained by rare mating of hml alpha-1 mutants with a heterothallic strain having the MATa ho HMRa HMLa genotype, many mating-deficient haploid segregants were found, while alpha mating-type segregants were observed in a similar diploid using an hml alpha-2 mutant. The mating-type-deficient haploid segregants were supposed to have the sterile alpha mating-type allele because the nonmating genetic trait always segregated with the mating-type locus. Sporogenous diploid cells obtained in the hml alpha-2 mutant clone had the MATa/MAT alpha HO/HO HMRa/HMRa hml alpha-2/hml alpha-2 genotype. These observations suggested that the hml alpha-1 allele produces a transposable element that gives rise to the sterile alpha mating type by transposition into the mating-type locus, and that the hml alpha-2 allele produces an element that provides alpha mating-type information, but is defective in the structure for transposition.

DNA Transposable Elements↗

Prognostic factors of chronic rhinosinusitis under long-term low-dose macrolide therapy.

We studied the immunological and histopathological factors that affect the prognosis of chronic rhinosinusitis under long-term low-dose macrolide therapy. Sixteen patients with chronic rhinosinusitis were given 200 mg clarithromycin or 150 mg roxithromycin orally once a day without other concurrent treatments for 2-3 months. Measurement of the serum IgE level, blood cell count and differential leukocyte count of the peripheral blood, cytological assessment of the nasal smear and computed tomographic (CT) scans of the paranasal sinuses were performed before treatment. The opacity of the sinuses was estimated and scored by the CT images. After treatment, anterior ethmoidal mucosa samples were collected, an infiltrated inflammatory cells, interferon (IFN)-gamma-positive cells and interleukin (IL)-4-positive cells were examined histologically and immunohistochemically. The severity of nasal symptoms was scored before and after treatment, and the improvement rate of the score (symptomatic improvement rate) was calculated. Patients with normal levels of serum IgE (</=250 U/ml) showed a significantly higher symptomatic improvement rate than those with high levels of serum IgE (42.1 +/- 11.2 vs. 4.9 +/- 3.1%, p = 0.046). The symptomatic improvement rate was inversely correlated with the eosinophil counts in the peripheral blood (r = -0.51, p = 0.04), in the nasal smear (r = -0.54, p = 0.045) and in the sinus mucosa (r = -0.54, p = 0.02). Meanwhile, the CT score, the number of IFN-gamma-positive cells and IL-4-positive cells in the sinus mucosa and neutrophil counts in the nasal smear and in the sinus mucosa failed to correlate with the symptomatic improvement rate. These results suggest that macrolide therapy is indicated for patients without atopy or smear/tissue/peripheral blood eosinophilia. On the contrary, the severity of the disease, Th1/Th2 dominance in the sinus mucosa and neutrophilia are unlikely to be prognostic factors of chronic rhinosinusitis under long-term low-dose marolide therapy.

Adolescent↗

Effect of rabbit aqueous humor obtained after cataract surgery on collagen gel contraction induced by bovine lens epithelial cells.

We evaluated the effect of specimens of pre- and postoperative aqueous humor on the contraction of collagen gels, and the effect of transforming growth factor-beta(2) (TGF-beta(2)) in postoperative aqueous humor. Rabbit aqueous humor was collected preoperatively and on postoperative day 7. Bovine lens epithelial cells (LECs) were cultured in collagen gel in F-12 nutrient mixture supplemented with 5% fetal bovine serum that contained 10% aqueous humor obtained under various conditions. Gel area was determined on day 4. Gels cultured with the medium that contained phosphate-buffered saline showed a statistically significant contraction after 4 days. Aqueous humor from aphakic or pseudophakic eyes significantly increased contraction, with both specimens having a similar effect. Approximately 60% of the contractile effect of the postoperative aqueous humor was neutralized by anti-TGF-beta(2) antibody. However, the promoting effect of the aqueous humor sampled postoperatively was less than that sampled preoperatively. Although the aqueous humor obtained postoperatively increased the contractility of the LECs, with the level of TGF-beta(2) apparently responsible for much of its effect, the effect was less than that observed in the aqueous humor obtained preoperatively.

Animals↗

Expression of the voltage-dependent chloride channel ClC-3 in human nasal tissue.

In the present study, ClC-3, one of the voltage-dependent chloride channels, was identified in human nasal tissue. In situ hybridization and immunohistochemical investigations demonstrated the localization of ClC-3 in the serous acini and ductal portions of submucosal nasal glands, which are the primary source of nasal secretion. Our data suggest that this channel contributes to nasal secretion via chloride transport. Its dysfunction might lead to abnormal nasal secretion in such pathological states as sinusitis.

Chloride Channels↗

Point mutation of the mitochondrial genome in Japanese deaf-mutism.

Recently, a number of hearing-impaired individuals with mitochondrial genome (mtDNA) mutations have been reported, and it is well known that the mtDNA mutations are responsible for the hearing disorder. We have demonstrated that the mtDNA mutation A3243G is responsible for adult-onset sensorineural hearing loss (SNHL). At the same time, a case in which SNHL occurred within 2 years from birth has been reported. The mtDNA mutations may be possible causes of prelingual deafness. In the present study, the mtDNA fragments from the deaf-mute persons were amplified by polymerase chain reaction, followed by a restriction enzyme fragment length polymorphism method and direct sequencing. We failed to find A3243G involvement in 46 deaf-mutes but found that 8.7% of them had A1555G which is an important cause of prelingual deafness, no less than autosomal recessive inheritance, in Japan.

Adult↗

Laser-assisted uvulopalatoplasty for habitual snoring without sleep apnea: outcome and complications.

Thirty patients suffering from habitual snoring were subjected to laser-assisted uvulopalatoplasty with a KTP/532 laser under local anesthesia. The patients selected for the present study had no complaints of severe sleep apnea. The surgical procedure included bilateral vertical incision through the palate at the base of the uvula with or without removal of the lower half of the uvula. Ninety-three percent of the patients showed apparent improvement of snoring following the operation. However, other sleep-related symptoms such as sleep quality and daytime sleepiness were not significantly improved. No major or critical complications such as massive bleeding and asphyxia occurred. Post-operative pain on deglutition disappeared in most patients 2 weeks after the operation. This procedure is safe, minimally invasive and effective for habitual snoring without apnea.

Adult↗

Budd-Chiari syndrome treated by percutaneous transluminal angioplasty. Report of a case.

Percutaneous transluminal angioplasty was performed in a patient with an incomplete obstruction of the inferior vena cava producing the Budd-Chiari syndrome. The web was successfully dilated percutaneously by three simultaneously inflated 9 mm balloon catheters. Symptoms and signs of obstruction of the inferior vena cava improved without any complications. This method is recommended because of its safety, low procedure related risk, and the possibility of recurrent use.

Angioplasty, Balloon↗