Biomedical subjects
Publications and source records attributed to T Takeuchi.
Almost all complement component 9 (C9) deficiency in Japan shows Arg95 Stop mutation of C9 gene. Therefore, we studied the prevalence of Arg95Stop mutation of C9 gene among 78 patients with SLE to elucidate the association of SLE and C9 deficiency. The Arg95Stop carrier frequency showed no significant difference between SLE patients and controls. Thus, C9 deficiency is not implicated in SLE susceptibility.
Deoxynybomycin was identified as an inducer of p21the/WAF1 gene following screening using a reporter, p21/luciferase. The present study examined its anti-proliferative effect on human tumor cell lines. Deoxynybomycin selectively inhibited growth of human osteoblastic sarcoma Saos-2, gastric cancer TMK-1, and monocytic leukemia THP-1 cells, but did not affect survival of normal human fibroblasts at doses up to 5 microg/ml. Results from an assay system using a panel of 39 human cancer cell lines indicated that deoxynybomycin has selective cytotoxic activity against lung carcinoma cell lines. Deoxynybomycin induced apoptosis in Saos-2, TMK-1, and THP-1 cells as revealed by DNA fragmentation and TUNEL assays. It inhibited topoisomerase I but not topoisomerase II. These results suggest that deoxynybomycin may be useful in cancer chemotherapy.
Participation of the nitric oxide-cyclic GMP pathway in nonadrenergic, noncholinergic (NANC) relaxation induced by electrical field stimulation of longitudinal muscle of the rectum of Wistar-ST rats was studied by using a selective inhibitor of soluble guanylyl cyclase, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). ODQ concentration dependently inhibited the relaxation and at 10 microM, maximally inhibited it by 83%. However, results obtained with N(G)-nitro-L-arginine, L-arginine and exogenously added nitric oxide excluded the participation of nitric oxide in the relaxation. An inhibitor of cyclic GMP-dependent protein kinase (PKG) partially (39%) inhibited the relaxation. ODQ also significantly inhibited the relaxation, which persisted after the PKG inhibitor-treatment, by 85%. The results strongly suggest that ODQ inhibits the NANC relaxation in a cyclic GMP-PKG pathway-independent manner.
alpha-Endosulfan and ss-endosulfan are isomers of endosulfan, a pesticide used worldwide. In this study, we examined the genotoxicity of [alpha]- and ss-endosulfan in vitro with a HepG2 cell line. We used sister chromatid exchanges (SCE), micronuclei (MN), and DNA strand breaks as detected by single-cell gel electrophoresis (SCG) assays as biomarkers to judge the genotoxicity of [alpha]- and ss-endosulfan at concentrations from 1 times 10(-12) M to 1 times 10(-3) M. After treating HepG2 cells for 48 hr with ss-endosulfan, SCE showed a significant increase at concentrations from 1 times 10(-7) M to 1 times 10(-5) M, and MN showed a significant increase at concentrations from 5 times 10(-5) M to 1 times 10(-3) M. [alpha]-Endosulfan failed to show significant effects in both the SCE and MN assays. After treating HepG2 cells with [alpha]- or ss-endosulfan for 1 hr, DNA strand breaks were significantly induced by [alpha]-endosulfan at concentrations from 2 times 10(-4) M to 1 times 10(-3) M, and by ss-endosulfan at 1 times 10(-3) M. The results of this study suggest that both [alpha]- and ss-endosulfan are genotoxic to HepG2 cells and that the genotoxicity of ss-endosulfan seems stronger than that of [alpha]-endosulfan.
Participation of nitric oxide, vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating peptide (PACAP) in nonadrenergic, noncholinergic (NANC) relaxation of longitudinal muscle of various intestinal regions in Sprague Dawley rats (8-week-old) was studied in vitro. Nitric oxide was suggested to participate in NANC relaxation of every intestinal region studied. But the participation was partial and its extent varied among the regions: significant in the proximal colon and rectum, and moderate in the jejunum, ileum and distal colon. Participation of PACAP in NANC relaxation was suggested only in the distal colon, while that of VIP was not detected in any of regions. Results obtained in the present study indicate that extent of participation of nitric oxide in NANC relaxation in Sprague Dawley rat intestine is more significant than those of other strains, Wistar and Wistar-ST.
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The effect of the dinitroaniline herbicides oryzalin and trifluralin on the growth of Entamoeba histolytica was examined. Oryzalin inhibited the growth of E. histolytica strain HM-1:IMSS. Trifluralin was less effective than oryzalin for this parasite. Entamoeba histolytica was more resistant to these dinitroanilines than other parasitic protozoa examined so far, including Leishmania spp., Trypanosoma brucei, Plasmodium falciparum, Toxoplasma gondii, and Cryptosporidium parvum. Colchicine, a potent microtubule inhibitor of animal cells, was much less effective for E. histolytica, even at very high concentrations. A reptilian parasite, Entamoeba invadens strain IP-1, examined for comparison, was more resistant to these dinitroanilines than E. histolytica. Accumulation of E. histolytica trophozoites in mitosis was observed after culture in 100 microM oryzalin. The inhibitory effect of oryzalin on the growth of E. histolytica trophozoites was abrogated by removal of the drug after exposure to 100 microM for 2 days. In parallel to the recovery of growth after removal of the drug, the percentage of trophozoites in mitosis was reduced to a normal level. The results indicate that treatment of trophozoites with oryzalin arrests mitosis and that its effect is reversible. Therefore, oryzalin is a useful tool for studies relating to the cell cycle of this parasite.
The indications for shunt operation in patients with idiopathic normal pressure hydrocephalus accompanied by brain atrophy (atypical idiopathic normal pressure hydrocephalus: AINPH) were investigated in 25 patients who satisfied the diagnostic criteria and underwent ventriculoperitoneal (VP) shunting. All patients had no apparent history of intra- or extracranial disease; dementia and gait disturbance as the main complaints; moderate to severe cerebral atrophy and ventricular dilatation and at least periventricular low density around the anterior horn on computed tomography; normal cerebrospinal fluid (CSF) pressure and filling of ventricles or cortical surface space with contrast medium at 24 hours on cisternography. The 15 male and 10 female patients were aged 47-83 years (mean 60.4 years). VP shunting was effective in 12 improved patients and not effective in 13 unimproved patients according to NPH grading. Pathological pressure wave on epidural pressure monitoring was observed in eight of 12 improved patients, but none of 13 unimproved patients. CSF outflow resistance was 35.33 +/- 11.16 mmHg/ml/min in improved patients and 9.12 +/- 3.51 mmHg/ml/min in unimproved patients. Preoperative serum alpha-1-antichymotrypsin value (alpha-1-ACT) was 42.02 +/- 8.64 mg/dl in improved patients and 61.72 +/- 11.03 mg/dl in unimproved patients. Alpha-1-ACT over 55 mg/dl occurred only in unimproved patients. Cerebral arteriovenous difference of oxygen content value (c-AVDO2) before and after surgery was 6.34 +/- 0.9 ml% and 5.91 +/- 0.78 ml% in improved patients and 4.75 +/- 1.85 ml% and 4.81 +/- 1.73 ml% in unimproved patients, respectively. The two cases with preoperative c-AVDO2 value over 8.5 ml% were both unimproved. Mean cerebral blood flow value before and after surgery was 23.51 +/- 4.20 ml/100 g/min and 45.22 +/- 8.11 ml/100 g/min in improved patients and 21.77 +/- 5.12 ml/100 g/min and 24.82 +/- 4.97 ml/100 g/min in unimproved patients, respectively. Cerebral atrophy in improved patients is caused by a cerebral circulation disturbance defined as a cerebral blood flow of penumbra or more due to cerebral arteriosclerosis, etc. A flow-chart of indications of shunt surgery for AINPH was prepared based on the results of the present study.
Chronic toxicity and carcinogenicity studies of 3-chloro-2-methylpropene (CMP), which has been widely used as an insecticide and chemical intermediate, were carried out in BDF1 mice. CMP was administered to mice in groups of 50 male and 50 female mice by the inhalation route 5 days per week for 104 weeks at doses of 0, 50, 100 or 200 ppm. Male and female mice in the CMP-exposed groups had decreased body weight but no noticeable clinical signs when compared with the control group. Dose-related increases in the incidences of gastric mucosal hyperplasia and squamous cell papilloma were observed in both sexes, and squamous cell carcinoma was observed in only one male mouse in the 100 ppm group. An increased incidence of Harderian gland adenoma in female mice was also recognized. In the nasal cavity, eosinophilic exudate associated with atrophy of olfactory epithelia, respiratory metaplasia of olfactory epithelia and olfactory gland, and eosinophilic changes in respiratory and olfactory epithelia were increased in both sexes.
A number of human cell lines derived from alveolar or embryonal rhabdomyosarcoma (RMS) have been described. To our knowledge, however, no cell line established from pleomorphic RMS has been reported. We describe here the establishment and characterization of a new human cell line, HS-RMS-1, which originated from a typical pleomorphic RMS arising in the gluteal muscle of a 26-year-old man. HS-RMS-1 cells had pseudotetraploid complex karyotypes with no specific abnormalities. Both in vitro and in vivo the cells on light microscopic examination exhibited pleomorphic features with immunopositive reaction for myogenic antigens including MyoD1 and myogenin, although no Z band-like structures were detected electron-microscopically. RT-PCR demonstrated the expression of MyoD1 and myogenin in HS-RMS-1 cells at the mRNA level, and direct sequencing analysis revealed cDNAs of MyoD1 and myogenin identical to those previously reported. This cell line, HS-RMS-1, established from pleomophic RMS will be useful for further studies including the molecular aspects of human RMS.
Only a few human malignant peripheral nerve sheath tumour (MPNST)-cell lines have been reported, and their characteristics have not been fully established. In this study, we established a new human cell line, HS-Sch-2, from an MPNST of the ordinary type which arose in a 54-year-old woman without von Recklinghausen's disease. This cell line was characterized by chromosome analysis, immunohistochemistry, ultrastructural examination, and direct sequencing of the p53 gene. The HS-Sch-2 cells have grown for more than 48 months in vitro, and exhibited hypotriploid karyotypes with complex chromosome abnormalities lacking a specific pattern. Histological features of the heterotranplanted nude mouse tumours were essentially the same as those of the original MPNST, with positive reactions for S-100 protein and neuron-specific enolase but not for epithelial membrane antigen, fibronectin or CD34. Ultrastructural examination in vivo revealed intricate interdigitation of long cytoplasmic processes and basal lamina-like structures. In addition, direct sequencing of the p53 gene detected a point mutation from CGT to CAT at codon 273 in exon 8. This HS-Sch-2 cell line, which exhibits distinctive morphological characteristics of MPNST and a p53 point mutation, will be useful for biological and pathological investigations of MPNST.
A novel 16-membered lactone antibiotic named tubelactomicin A was isolated from the culture broth of an actinomycete strain. The producing organism, designated MK703-102F1, was identified as a member of Nocardia. Tubelactomicin A was isolated from the culture broth by Diaion HP20 absorption, ethyl acetate extraction, silica gel and Sephadex LH-20 column chromatographies and centrifugal liquid-liquid partition chromatography (CPC). Tubelactomicin A showed strong activity against acid-fast bacteria including the drug-resistant strains.
A novel 16-membered lactone antibiotic named tubelactomicin A was isolated from the culture broth of Nocaradia sp. MK703-102F1. The structure of tubelactomicin A was assigned by spectroscopic analysis and the absolute configuration was determined by X-ray crystallographic analysis.
A new compound, migrastatin, was isolated from a cultured broth of Streptomyces sp. MK929-43F1, as an inhibitor of tumor cell migration. It was purified by column chromatographies on silica gel and Sephadex LH-20 and HPLC. Migrastatin has the molecular formula of C27H39NO7 consisting of 14-membered macrolide and glutarimide moiety. It inhibited spontaneous migration of human esophageal cancer EC17 cells. Migration inhibitory activity of migrastatin was not dependent on cytotoxicity or inhibition of protein synthesis.
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Three new sesquiterpenoid aromatic esters designated melleolides K (1), L (2) and M (3) were isolated from the cultured mycelia of Armillariella mellea (Vahl. ex Fr.) Karst. Structures of these compounds were determined on the basis of various NMR spectral data, chemical transformations and X-ray analysis. Compounds 1, 2 and 3 showed antimicrobial activities.
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