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Biomedical subjects

S Ohta

Publications and source records attributed to S Ohta.

At least 613 records · Page 34Linked to original sources
PubMed1991

Neuronal differentiation of Ewing's sarcoma induced by cholera toxin B and bromodeoxyuridine--establishment of Ewing's sarcoma cell line and histochemical study.

An Ewing's sarcoma (ES) cell line was established from a metastatic bone marrow specimen in a patient with advanced disease, and some histochemical characteristics were investigated by neuronal differentiation induced with cholera toxin B (CTB) and bromodeoxyuridine (BrdU). Neuronal differentiation was investigated by the expression of neurofilament and Leu-7, and glial differentiation was observed by expression of S-100 protein. Neurofilament (NF) and Leu-7 were positive in ES cells and these were expressed more intensively by induction with CTB than with BrdU. There was no expression of S-100 protein in untreated or differentiated ES cells. ES cells became differentiated to neuronal cells with CTB and BrdU, but it was not observed, that ES cells had the potential to differentiate to glial cells. It appears that ES is of more primitive neural origin than neuroblastoma, primitive neuroectodermal tumors and other related neural tumors.

Antigens, Differentiation↗
PubMed1991

Familial juvenile nephronophthisis in two siblings--histological findings at an early stage.

We present two female siblings with familial juvenile nephronophthisis (FJN) which was diagnosed at the early stage of renal failure. Diagnosis was made during the investigation of anemia in case 1 and by a subsequent family survey in case 2. Most patients with FJN are not identified until the terminal stage of renal failure and such cases have rarely been reported in Japan. Case 2 had a reduction in the maximum urinary concentration ability but no azotemia, and among the FJN patients reported in Japan so far she has the least advanced renal disease. Histological examination of the renal biopsy in case 1 showed typical findings of FJN, such as thickening and lamination of the tubular basement membrane (TBM), interstitial fibrosis, and round cell infiltration of the interstitium. In case 2, renal biopsy revealed an irregular marked thickening of the TBM with trivial interstitial changes and a normal glomerular appearance. The histology of these two cases suggests that the TBM may be the primary site affected in FJN.

Child↗
PubMed1991

1-Methyl-1,2,3,4-tetrahydroisoquinoline, decreasing in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated mouse, prevents parkinsonism-like behavior abnormalities.

In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mouse brain, there was no significant increase or decrease in the content of an endogenous amine, 1,2,3,4-tetrahydroisoquinoline (TIQ), which is well noted for inducing parkinsonism, whereas another endogenous amine, 1-methyl-1,2,3,4-tetrahydroisoquinoline (1-MeTIQ), was markedly reduced. This result agrees with the finding in human idiopathic parkinsonianism, confirmed by our previous research. In addition, pretreatment with 1-MeTIQ completely prevented MPTP- or TIQ-inducing bradykinesia, a symptom of parkinsonism. This study confirmed that 1-MeTIQ plays an important role in preventing the pathogenesis of parkinsonism and is a possible leading compound of anti-parkinsonism agents.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1991

On the transforming growth factor beta-like activity of synthetic polypeptides comprising the amino-terminal sequence of human parathyroid hormone-related peptide.

Purified native forms of human parathyroid hormone-related peptide (PTHrp) have recently been reported to display biological activities characteristic of transforming growth factor beta (TGF-beta). The TGF-beta-like property of PTHrp may reside within the amino N-terminal PTH-receptor binding region of the polypeptide, since a synthetic analog corresponding to amino acids 1-36 of human PTHrp is as active as purified native PTHrp in bioassays specific to TGF-beta. Complete lack of structural similarity between PTHrp and TGF-beta prompted us to address the question whether copresence of the TGF-beta-like and PTH-like biological activities in the N-terminal sequence of the PTHrp molecule is a general phenomenon observable with different N-terminal PTHrp peptides of varying amino acid chain length in a variety of target cells that respond in defined ways to TGF-beta in vitro. Two forms of synthetic N-terminal human PTHrp, PTHrp-(1-34) and [Tyr40]PTHrp-(1-40), which are fully active in conventional assays for PTH/PTHrp, were tested for effects in three in vitro bioassay systems for TGF-beta: 1) stimulation, and 2) inhibition, respectively, of epidermal growth factor-dependent soft-agar colony formation of either normal rat kidney-derived fibroblasts (NRK 49F) or human lung carcinoma cells (A549); and 3) biosynthesis of metabolically labeled fibronectin in both NRK 49F cells and clonal osteoblastic rat osteosarcoma cells (ROS 17/2.8). Human TGF-beta over the dose range of 2.5-80 pM significantly stimulated or inhibited soft-agar colony formation of either NRK 49F or A549 cells, respectively, and caused a severalfold increase in biosynthetically labeled [35S]fibronectin in NRK 49F and ROS 17/2.8 cells. In contrast, none of PTHrp-(1-34), [Tyr40]PTHrp-(1-40), and synthetic human PTH-(1-34), each tested at 0.1-10 nM, displayed detectable biological activity in any of the three assay systems. In addition, covalent cross-linking of intact NRK 49F and ROS 17/2.8 cells with either [125I]TGF-beta or 125I-[Tyr40] PTHrp-(1-40) revealed the presence of several distinct affinity-labeled receptor species for TGF-beta in both cell types and the 80K PTH/PTHrp receptors in ROS 17/2.8 cells. The affinity-labeled TGF-beta receptor species were insensitive to excess PTHrp and PTH peptides, and the 80K PTH/PTHrp receptors were insensitive to excess TGF-beta, indicating that PTHrp and TGF-beta do not cross-react with respect to receptor binding for interaction with these cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Affinity Labels↗
PubMed1991

Structure-activity relationships of rat neuromedin U for smooth muscle contraction.

Rat neuromedin U (r-NMU) and its fragment peptide amides were synthesized by solid-phase methodology. Using a chicken crop smooth muscle contraction assay, the potency of r-NMU and its fragments relative to porcine neuromedin U-8 (p-NMU-8) was r-NMU: 10.25 +/- 2.88, r-NMU (6-23): 8.01 +/- 1.04, r-NMU (10-23): 2.76 +/- 0.46, r-NMU (13-23): 2.81 +/- 0.52, and r-NMU (16-23): 0.88 +/- 0.19, respectively. Two heptapeptides, r-NMU (17-23) and r-NMU (16-22), had a relative potency of 0.61 and 0.03 respectively, and elicited maximal contraction at a dose of 10 microM to a similar degree to p-NMU-8. The other shorter C-terminal fragments did not elicit the maximal contraction or any activity. In a rat uterus contraction assay, r-NMU (13-23), but not r-NMU (16-23), at a dose of 4 nM retained as high a stimulatory activity as r-NMU itself. r-NMU (17-22) was the smallest peptide fragment to elicit the maximal sustained contraction at 10 microM. These results indicate that the amino acid sequence Phe-Leu-Phe-Arg-Pro-Arg, corresponding to positions 17 to 22 of r-NMU, may be essential for contractile activity. N-terminal peptide segments Tyr-Gln-Gly-Pro corresponding to positions 6 to 9, and Ser-Gly-Gly corresponding to positions 13 to 15, appear to be of special importance for potent activity.

Amino Acid Sequence↗
PubMed1991

[Protective effects of the fractions extracted from the callus of Acer nikoense Maxim. on carbon tetrachloride induced liver injury].

The decoctions extracted from the bark and leaf of Acer nikoense Maxim. (AN) have been used as a folk medicine for eye-wash and hepatic disease. As previously reported, the methanol extract from the bark of AN and the fractions of the methanol extract have protective effects for liver injury induced by carbon tetrachloride (CCl4) in rats. In this study, protective effects of the fractions extracted from the callus of AN were investigated on CCl4-induced liver injury in rat. The active principles for the protection of CCl4-induced liver injury were recognized in a fraction (EF 3-3) obtained by using silica gel chromatography (solvent: CHCl3-MeOH-H2O). The components were further fractionated by silica gel chromatography followed by gel filtration (solvent: CHCl3-MeOH). In addition, the mechanism of the protective action against liver injury induced by CCl4 was also examined. The fractions with protective effects in vivo showed the inhibitory effects on CCl4-dependent lipid peroxidation in microsomal fraction in vitro.

Animals↗
PubMed1991

[Studies on chemical protectors against radiation. XXXIII. Protective mechanisms of various compounds against skin injury induced by radiation].

The radiation protective mechanisms on skin injury induced by soft X-irradiation were investigated by use of various radiation protective agents such as sulfur compounds (MEA, MEG, thiourea), nucleic acid constitutional compounds (adenosine, inosine), antioxidative compounds (sesamol, ferulic acid, ascorbic acid), crude drugs (Rosae Fructus, Anemarrhenae Rhizoma, Trapae Fructus, Forsythiae Fructus, Aloe arborescens). Scavenge action of activated oxygen, inhibitory effect of lipid peroxidation, induction of antioxidative protein and protective effect against damage of deoxyribonucleic acid and superoxide dismutase by X-irradiation were evaluated as the radiation protective mechanisms, and relationship between these results and protective effect of skin injury induced by radiation was studied.

Adenosine↗
PubMed1991

[Protective effects of various methanol extracts of crude drugs on experimental hepatic injury induced by alpha-naphthylisothiocyanate in rats].

Sixty seven methanol extracts of crude drugs were examined for their effects to protect hepatic injury induced by alpha-naphthylisothiocyanate (ANIT) in rats. In terms of the release of intrahepatic enzymes and bilirubin into the serum, 19 extracts were found to suppress the increase in the concentration of serum bilirubin by ANIT. Out of the 19 extracts those of Berchemia Racemosa Caulis, Aurantii Nobilis Pericarpium, Polygoni Avicularis Herba and Gentianae Scabrae Radix, also inhibited the release of several intrahepatic enzymes used as parenchymal injury parameter.

1-Naphthylisothiocyanate↗
PubMed1991

[Studies on chemical protectors against radiation. XXXIV. Survival effects of aqueous extracts of various Chinese traditional medicines on radiation injury].

In order to develop a nontoxic radioprotector, 60 kinds of Chinese traditional medicines were chosen, and their aqueous extracts tested for their survival effects against the lethal effect of X-irradiation in mice. Radiation factors used were as follows: soft X-rays, 2100R (5.418 x 10(-1) Ckg-1), 70 kVp, 10 mA, 10 mm acrylic filter, 70R (1.806 x 10(-2) Ckg-1)/min. Among 60 medicines tested by intraperitoneal injection immediately before the irradiation, 15 are shown to have the significant survival effect. These 15 effective medicines were also tested by intraperitoneal injection after the irradiation, and the survival effect was recognized in Keisi-syakuyaku-chimo-to, Keigai-rengyo-to, Simotu-to, Syakuyaku-kanzo-to and Hange-syasin-to. On the other hand, the survival effects of 25 medicines including the above-mentioned 15 medicines were investigated by the oral administration at various times before or after the irradiation. As the result of these studies, only Keigai-rengyo-to and Bukuryo-in are shown to have the significant survival effect when administered 2 h before the irradiation.

Administration, Oral↗
PubMed1991

Survey of infectious coryza of chickens in Indonesia.

A survey of infectious coryza of chickens was performed in West Jawa of Indonesia between 1987 to 1988 by the detection of hemagglutination-inhibition (HI) antibody against Haemophilus paragallinarum (Hpg) in non-vaccinated healthy laying (12 farms, 196 chickens) and native (8 farms, 197 chickens) chickens. HI antibodies against Hpg were detected not only in the native chickens but also in the laying chickens, regardless of the district, and were observed in 70% (14/20) of farms and 19% (73/393) of chickens. HI antibodies against serotype A were detected from 11 farms (55%) and 11% (45/393) in chickens. Those against serotype C were detected from 5 farms (25%) and 8% (30/393) in chickens. Three Hpg strains were isolated from different chickens affected with infectious coryza. Two of them were identified as type A and the other as type C by the rapid plate agglutination test. These results demonstrated that the outbreaks of infectious coryza caused by serotype A and C strains had occurred in Indonesia.

Animals↗
PubMed1991

Expression of hemagglutinin of Haemophilus paragallinarum serotype A in Escherichia coli.

The genomic DNA of Haemophilus paragallinarum (Hpg) serotype A strain 221 was cloned into vector plasmid pBR322. The recombinant plasmids were introduced into Escherichia coli (E. coli) strain C600. Subsequently, a total of 277 transformants were obtained. One, designated strain no. 6, expressed hemagglutination activity against chicken erythrocytes. Strain no. 6 contained the recombinant plasmid pNV102, and DNA of about 2.57 kb was inserted into pNV102. When strain no. 6 was cured of pNV102, the strain lost hemagglutination activity. When the cured strain was retransformed with pNV102, hemagglutination activity was restored. E. coli strain no. 6 reacted with monoclonal antibody specific to the hemagglutinin of Hpg serotype A in a dot-blotting analysis. Chickens immunized with the inactivated strain no. 6 produced the hemagglutination inhibition (HI) antibody, and chickens possessing the HI antibody showed protection against challenge exposure by Hpg strain 221.

Animals↗
PubMed1991

[In situ hybridization study on the detection of HPV DNA in adenocarcinoma and adenosquamous carcinoma of the uterine cervix].

Human papillomavirus (HPV) types 16 and 18 have been found closely associated with squamous cell carcinoma and related lesions of the uterine cervix. In order to investigate the relationship between HPV and adenocarcinoma and adenosquamous carcinoma of the uterine cervix, formalin-fixed, paraffinembedded tissues prepared from 38 cases consisting of 30 cases of adenocarcinoma and 8 cases of adenosquamous carcinoma were examined for the presence of HPV DNA by in situ hybridization with digoxigenin labeled HPV 6/11, 16, 18 DNA probes. HPV DNA was localized on the nuclei of the cancer cells in adenocarcinoma and adenosquamous carcinoma. HPV DNA was detected in 13 cases (43.3%) of adenocarcinoma and 4 cases (50.0%) of adenosquamous carcinoma, and HPV type 18 DNA was detected in 13 cases (34.2%) of adenocarcinoma and adenosquamous carcinoma. These findings suggest an association between HPV, especially HPV type 18, and adenocarcinoma and adenosquamous carcinoma of the uterine cervix.

Adenocarcinoma↗
PubMed1991

Respiration-deficient cells are caused by a single point mutation in the mitochondrial tRNA-Leu (UUR) gene in mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS).

MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes) is a major subgroup of heterogeneous mitochondrial diseases. For identifying a mutation in the mitochondrial gene, we isolated, from the same muscle tissue from a patient with MELAS, cell lines with distinctly different phenotypes: one was respiration-deficient, and the other was apparently normal. Compared with the normal cells, only one A-to-G nucleotide transition at nucleotide 3243 in the tRNA-Leu (UUR) gene was found in whole mtDNA of the respiration-deficient cells. This mutation was also found in eight patients, from unrelated families, who had MELAS in a heteroplasmic manner but was not found in control individuals. Therefore, the single point mutation causes the functional abnormality in the respiratory chain of mitochondria.

Acidosis, Lactic↗
PubMed1991

Retrospective analysis of late intensification therapy with high-dose methotrexate for standard-risk acute lymphoblastic leukemia in childhood (CCLSG-S811 study). The Children's Cancer and Leukemia Study Group.

Using the CCLSG-S811 protocol for children with standard-risk acute lymphoblastic leukemia (ALL), late intensification therapy (LIT) with high-dose methotrexate (HD-MTX) was conducted without randomization. Of 118 eligible patients, 114 attained complete remission and 82 maintained continuous complete remission (CCR) for at least 3 years, completing the entire S811 regimen. Among the latter, 74 patients received LIT with HD-MTX between 2-3 years after CCR onset. MTX (2,000 mg/m2 per dose per week) was administered by 24 h infusion and three doses were given every 12 weeks. Leucovorin rescue (15 mg/m2 i.v.) every 6 h was initiated 12 h after the end of MTX infusion for seven doses. As regular maintenance chemotherapy, intermittent (Regimen A) or continuous (Regimen B) MTX plus 6-mercaptopurine (6MP) combined with pulses of prednisolone and vincristine was administered (Koizumi S, Fujimoto T, Takeda T, et al. Cancer 1988; 61: 1292-1300). Retrospective analysis revealed that patients on Regimen A who started LIT earlier (within 2 years of CCR onset (n = 23)) showed a higher rate of event-free survival (EFS) at 8 years (95.5% +/- 4.4%, mean +/- S.E.) than patients who started LIT later (2.5 years after CCR onset (n = 18, 66.2% +/- 11.3%, p less than 0.01)). In addition, the superiority of four or five courses of the LIT (n = 39) as compared to 2 or 3 courses (n = 35) was noted for both regimens. The data suggest that early and aggressive LIT with HD-MTX may improve the long-term survival of childhood ALL patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

[A two-year-old clinically manifesting carrier of Duchenne muscular dystrophy].

A two-year-old symptomatic carrier of Duchenne muscular dystrophy (DMD) confirmed by dystrophin immunohistochemical study was reported. She had mild proximal muscular weakness and elevated serum creatine kinase (CK) level. There were no family members of DMD. CT examination revealed low density areas in the muscles similar to that seen in the early stage of DMD. Biopsied specimen of muscle showed myopathic changes with necrotic and regenerating fibers. The immunohistochemical study using an antiserum against dystrophin showed the mosaic expression of the surface membrane, with positive and negative patches. Accordingly, she was strongly suggested to be a DMD carrier. This case shows that dystrophin immunohistochemistry is useful for diagnosis of a DMD carrier without affected family members.

Child, Preschool↗