326
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Wu MC, Takagi K, Okuyama S, Ohsawa M, Masahashi T, Narita O, Tomoda Y. Determination of serum delta 5-3 beta-hydroxysteroid sulphates by combined high-performance liquid chromatography and immobilized 3 beta,17 beta-hydroxysteroid dehydrogenase in column form. JOURNAL OF CHROMATOGRAPHY 1986; 377:121-9. [PMID: 2940254 DOI: 10.1016/s0378-4347(00)80767-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We studied the use of an immobilized enzyme, covalently bound to aminopropyl-CPG, in the analysis of individual delta 5-3 beta-hydroxysteroid sulphates. A microcolumn with immobilized 3 beta,17 beta-hydroxysteroid dehydrogenase was prepared and used together with high-performance liquid chromatography (HPLC). The reduced nicotinamide-adenine dinucleotide produced from delta 5-3 beta-hydroxysteroids by this enzyme was fluorimetrically determined. The immobilized enzyme was sufficiently stable for at least one month or for 180 tests when used repeatedly. A clinical trial demonstrated that this HPLC-immobilized enzyme method is superior to the soluble enzyme method, giving reliable and reproducible results at a low cost.
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327
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Ochi T, Ishiguro T, Ohsawa M. Induction of alkaline-labile sites in DNA by benzo [a]pyrene and the repair of those lesions in cultured Chinese hamster cells. Mutat Res 1986; 165:31-8. [PMID: 3941669 DOI: 10.1016/0167-8817(86)90006-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Formation of alkaline-labile sites in DNA by S9-activated benzo [a]pyrene (B [a]P) and the repair of those lesions were investigated using the technique of alkaline elution in cultured Chinese hamster V79 cells. When the cells were treated with B [a]P (1-5 micrograms/ml) there was negligible increase in DNA elution at pH 12.1 as compared to untreated controls. However, the elution of DNA increased at pH 12.6 with a concentration dependency, thereby indicating formation of alkaline-labile sites in DNA by B [a]P. After 4 h of repair incubation the elution of DNA at pH 12.6 of B [a]P (5 micrograms/ml) treated cells returned to the control levels. The half-life of alkaline-labile sites formed by B [a]P was approximately 1.5 h. Inhibitors of DNA-repair synthesis, hydroxyurea (HU) and 1-beta-D-arabinofuranosyl cytosine (ara-C) when added simultaneously with S9-activated B [a]P for 3 h showed an increase in elution of DNA at pH 12.1, indicating that a population of B [a]P-induced DNA lesions could be removed by a rapid DNA-repair process. These results indicate that at least two kinds of DNA lesions, repairable alkaline-labile sites and rapidly repairable DNA single-strand breaks, are detected after B [a]P treatment by the use of the alkaline elution procedure, by changing elution pH.
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328
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Kawanishi M, Shimada Y, Ohsawa M, Narita O. [Effects of TZU-0460, a new histamine H2-receptor blocker, on the prophylaxis of acid aspiration pneumonitis and its placental transfer]. MASUI. THE JAPANESE JOURNAL OF ANESTHESIOLOGY 1986; 35:130-8. [PMID: 2872344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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329
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Masahashi T, Wu MC, Ohsawa M, Asai M, Ichikawa Y, Hanai K, Kikkawa H, Mizutani S, Narita O, Tomoda Y. Spironolactone therapy for hyperandrogenic anovulatory women--clinical and endocrinological study. NIHON SANKA FUJINKA GAKKAI ZASSHI 1986; 38:95-101. [PMID: 3950464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Seventeen patients with irregular menstrual periods and androgenic symptoms such as excessive hair growth, acne, and oily skin were treated with spironolactone. The basal levels of serum testosterone (T), dihydrotestosterone (DHT), estradiol (E2), and luteinizing hormone (LH) were significantly higher in the patients than in the controls. After a 4-week treatment with spironolactone, serum T and DHT showed significant decreases. Before treatment, the serum sex hormone binding globulin (SHBG) levels were significantly lower in the patients than in the controls. After initiation of the spironolactone treatment, the SHBG levels tended to increase but not significantly. Spironolactone treatment resulted in the improvement or disappearance of acne in 4 of 5 patients who suffered from this ailment. Improvement of hirsutism was obtained in 2 of 10 patients. Although 4 oligomenorrheic patients and 6 amenorrheic patients showed anovulatory bleeding but did not ovulate, 2 patients in the amenorrheic group ovulated. Two patients complained of tiredness and weakness, and 2 others of polyuria and polydipsia. Both groups showed only temporary symptoms, so treatment was not interrupted. Spironolactone has beneficial effects on ovarian function and few side effects, so it may prove to be an effective anti-androgen, especially for hyperandrogenic anovulatory patients.
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330
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Ochi T, Ishiguro T, Ohsawa M. Release of hydrogen peroxide from polymorphonuclear leukocytes stimulated with lambda-carrageenan. THE JAPANESE JOURNAL OF EXPERIMENTAL MEDICINE 1985; 55:245-9. [PMID: 3835323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The production of hydrogen peroxide (H2O2) by polymorphonuclear leukocytes (PMNs) that are exposed to lambda-carrageenan (100 micrograms/ml) and 12-0-tetradecanoylphorbol-13-acetate (TPA, 100 ng/ml) was measured by a colorimetric method. After a lag period of 15 min the release of H2O2 by carrageenan-stimulated PMNs increased until a plateau level was reached at 60 min. The amount of H2O2 released was dependent on the number of cells in well or the concentration of carrageenan, reaching a maximum production of H2O2 at 5 X 10(6) cells per 3-cm dish and 100 micrograms/ml of carrageenan, respectively. The maximum amount of released H2O2 from carrageenan-treated PMNs was approximately 11 n moles/hr/10(6) cells. In contrast, TPA-stimulated PMNs released H2O2 linearly for 60 min without a lag period and produced a maximum of 60 n moles/hr/10(6) cells. These results show that lambda-carrageenan stimulates an oxidative burst from in vitro PMNs and furthermore suggest that these carrageenan-stimulated PMNs release sufficient H2O2 to induce DNA damage in mammalian cells.
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331
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Ochi T, Ishiguro T, Ohsawa M. The effects of cell cycle position on the cytotoxicity and mutagenicity of benzo(a)pyrene in cultured Chinese hamster cells. Toxicol Lett 1985; 29:183-90. [PMID: 4089885 DOI: 10.1016/0378-4274(85)90040-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The induction of cytotoxicity and mutation to 6-thioguanine resistance (6TGr) by S9-activated benzo(a)pyrene (B(a)P) was studied in asynchronized and synchronized Chinese hamster V79 cells. After treatment of asynchronized populations with B(a)P (0.25-2 micrograms/ml) in the presence of S9 for 3 h, the number of 6TGr cells increased. The increase was concentration-dependent up to 2 micrograms/ml, and was accompanied by a concomitant concentration-dependent decrease in cell survival. Synchronized cells were treated with B(a)P for 2 h at 2-h intervals after release from the G1/S block by hydroxyurea (HU). The cytotoxicity of 2 micrograms/ml of B(a)P was maximal at 0 h after HU release, i.e., G1/S phase, and also at 2 h after HU release, i.e., early S phase. Thereafter, it decreased with the progression of the cell cycle. Similarly, treatment with B(a)P at 0 h and 2 h after HU release resulted in the maximum incidence of 6TGr mutants, after which the incidence showed a decrease from 4-10 h after HU release. These results indicate that the cells in G1/S and early S phase are highly susceptible to cytotoxic and mutagenic damage induced by B(a)P and suggest the presence of a specific hot spot in the cell cycle for mutagenesis by the carcinogen B(a)P in cultured hamster cells.
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332
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Ohsawa M, Wu MC, Masahashi T, Asai M, Narita O. Cyclic therapy resulted in pregnancy in premature ovarian failure. Obstet Gynecol 1985; 66:64S-67S. [PMID: 2410842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A successful pregnancy in a patient with premature ovarian failure is described. Increased serum gonadotropin titers, decreased serum estrogen levels, and lack of ovarian follicles on histologic examination confirmed the state of ovarian failure. The patient conceived after several courses of cyclical treatment with estrogen-progestin. A possible relationship between the estrogen treatment and subsequent pregnancy is discussed.
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333
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Ochi T, Ohsawa M. Participation of active oxygen species in the induction of chromosomal aberrations by cadmium chloride in cultured Chinese hamster cells. Mutat Res 1985; 143:137-42. [PMID: 2989680 DOI: 10.1016/s0165-7992(85)80024-5] [Citation(s) in RCA: 75] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of various scavengers of active oxygen species on the induction of chromosomal aberrations by cadmium chloride (CdCl2) was investigated in cultured Chinese hamster V79 cells. Incidences of chromosomal aberrations by CdCl2 were partially or fully reduced by the presence of catalase, mannitol (a scavenger of hydroxyl radicals) and butylated hydroxytoluene (BHT, an antioxidant). These findings may indicate participation of the active oxygen species such as hydrogen peroxide (H2O2) or hydroxyl radicals in the clastogenicity of cadmium. In contrast, superoxide dismutase (SOD) and dimethylfuran (a scavenger of singlet oxygen) did not influence incidences of chromosomal aberrations by CdCl2. These results suggest that superoxide anion and singlet oxygen are not directly involved in the clastogenicity of the metal. The presence of aminotriazole (an inhibitor of catalase) increased incidences of chromosomal aberrations by CdCl2. This emphasizes participation of H2O2 in the clastogenicity of cadmium.
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334
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Asai M, Ohsawa M, Ichikawa Y, Wu MC, Masahashi T, Narita O, Matsui N, Kashiwamata S. [Changes in % free testosterone and sex-hormone binding globulin during danazol administration]. NIHON SANKA FUJINKA GAKKAI ZASSHI 1985; 37:1001-6. [PMID: 4040541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
To clarify the androgen balance on the administration of danazol a study was conducted on the levels of % free testosterone (% free T) and sex-hormone-binding globulin (SHBG) during the therapy and the binding properties of danazol to SHBG and androgen receptor. It was found that danazol displaced testosterone (T) from SHBG and R1881 from androgen receptor, in vitro. During treatment with danazol, levels of % free T were increased about three fold, but in contrast the SHBG concentration were significantly decreased. Similar changes in % free T were observed by computer simulation. These data suggest that the androgenic effects of danazol were the results of increased free T levels by the T-displacing ability of danazol from SHBG. The concentration of SHBG might be reduced as a consequence of increased levels of free T. On the other hand, danazol binding to androgen receptor might partially inhibit the action of excess amounts of free T, because the androgenization during therapy was too weak to compare the levels of free T.
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335
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Ohsawa M, Kuwae T, Kurata M. Effect of eicosapentaenoic acid on mouse peritoneal exudate cells. Chem Pharm Bull (Tokyo) 1985; 33:2585-6. [PMID: 2998634 DOI: 10.1248/cpb.33.2585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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336
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Kimura H, Saheki S, Yoshida K, Ohsawa M. Characterization of purified group-specific components (Gc 1 and Gc 2 proteins) from human plasma. NIHON HOIGAKU ZASSHI = THE JAPANESE JOURNAL OF LEGAL MEDICINE 1985; 39:113-23. [PMID: 4087509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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337
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Ohsawa M, Narita O, Ichikawa Y, Masahashi T, Wu MC, Suganuma N, Asai M, Mizutani S, Tomoda Y, Matsui N. Binding capacity of sex-hormone-binding globulin and free testosterone determination in evaluation of hirsute women. NIHON SANKA FUJINKA GAKKAI ZASSHI 1985; 37:416-20. [PMID: 4038991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
To investigate the relation between free testosterone (T) and binding capacity of sex-hormone-binding globulin (SHBG-BC) and a degree of hirsutism, 34 women were classified into 3 groups according to the criteria of Ferriman and Gallway on the degree of the hirsutism; 11 patients with a total score of 1 to 3 (group 1), 8 patients with a total score of 4 to 10 (group 2), and 15 patients with a total score of 11 or more (group 3). Total plasma T, SHBG-BC, and free plasma T were measured in each group, and they were compared with those of controls. In groups 1 and 2, mean levels of total T were slightly higher than in controls but the differences were not significant. Total T levels were extremely elevated in group 3. Mean level of SHBG-BC in group 1 was slightly lower than in controls but was not statistically significant. SHBG-BC was drastically reduced in groups 2 and 3. The percent free T levels and free T concentrations were significantly higher than those of controls in groups 2 and 3, but not in group 1. The results suggested that decreased SHBG-BC and increased free T might be the cause of hirsutism in women with normal total T levels.
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338
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Abstract
A report is made of a 44-year-old female who died of malignant hyperthermia during general anesthesia for an operation of left subtrochanteric femoral fracture. Symptoms began with increases in heart rate and blood pressure after the introduction of anesthesia with halothane and were accelerated by the administration of succinylcholine, followed by muscle rigidity and high temperature. The typical wine red urine was observed. The oral temperature of 42 degrees C was recorded within 1 h after succinylcholine. The rectal temperature was 30 degrees C 22 h after death. Severe pulmonary edema and tubular necrosis of the kidney were found by postmortem examination. No latent myopathy was observed. The creatine phosphokinase levels in plasma obtained after the onset of malignant hyperthermia and at the time of autopsy were abnormally high and were 5632 and 34,854 mU/ml, respectively. Plasma myoglobin levels were 130,000 and 2.8 X 10(6) ng/ml, respectively.
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339
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Finger W, Ohsawa M. Accuracy of cast restorations produced by a refractory die-investing technique. J Prosthet Dent 1984; 52:800-3. [PMID: 6392512 DOI: 10.1016/s0022-3913(84)80007-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The present study has demonstrated a simple, controlled technique to produce consistently accurate gold alloy restorations. Distortion of the wax patterns was minimized with an adequate refractory die-investing technique.
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340
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Suda T, Fujiwara H, Kobayashi Y, Saitoh Y, Muramatsu M, Ohsawa M, Asari H. [Transvascular removal of catheter fragments from the great vessels and the heart]. RINSHO HOSHASEN. CLINICAL RADIOGRAPHY 1984; 29:1509-12. [PMID: 6530792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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341
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Ochi T, Mogi M, Watanabe M, Ohsawa M. Induction of chromosomal aberrations in cultured Chinese hamster cells by short-term treatment with cadmium chloride. Mutat Res 1984; 137:103-9. [PMID: 6472321 DOI: 10.1016/0165-1218(84)90098-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Inducibility of chromosomal aberrations and cytotoxicity in cultured Chinese hamster cells by cadmium chloride (CdCl2) was investigated under 3 different treatment conditions: (i) 2-h treatment in MEM medium supplemented with 10% fetal bovine serum (MEM + 10% FBS) or (ii) in HEPES-buffered Hanks' solution (HEPES-Hanks), and (iii) continuous treatment for 24 h in MEM + 10% FBS. Two-h treatment with CdCl2 in HEPES-Hanks or continuous treatment for 24 h in MEM + 10% FBS was respectively 2 or 3 times more cytotoxic than 2-h treatment with the metal in MEM + 10% FBS. Continuous treatment for 24 h with a CdCl2 concentration in excess of 5 X 10(-6) M was too toxic to the cells to allow chromosomal analysis, and moreover, only a slight increase in incidence of chromosomal aberrations was observed at a concentration of 5 X 10(-6) M CdCl2. In contrast, a marked and concentration-dependent increase in incidence of chromosomal aberrations was observed after post-treatment culture for 22 h follows 2-h treatment with 1 X 10(-6) M to 5 X 10(-5) M of CdCl2 in both MEM + 10% FBS and HEPES-Hanks. Two-h treatment with cadmium in HEPES-Hanks was approximately 3 times more potent for the induction of chromosomal aberrations than that in MEM + 10% FBS. Types of aberrations induced by CdCl2 mainly consisted of chromatid gaps and breaks, although a few exchanges, dicentrics and fragmentations were observed at high concentrations of cadmium. Increase in incidence of tetraploidy was also observed with a concentration dependency after 2-h treatment with CdCl2. Potency of CdCl2 to induce chromosomal aberrations after 2-h exposure was comparable to that of benzo[a]pyrene activated with S9 at equitoxic concentrations. Two-h treatment with cadmium markedly inhibited incorporation of [3H]thymidine, even at concentrations at which incorporation of [3H]uridine or [3H]leucine was less inhibited. However, the inhibition of [3H]thymidine incorporation by cadmium was reversible and the incorporation restored to the control level during 2-6 h of post-treatment incubation. These findings suggest that restoration of DNA synthesis after cadmium exposure is required for the efficient detection of chromosomal aberrations induced by the metal.
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342
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Hoshino S, Ohsawa M, Amano S, Nishiguchi K, Sakai Y. [Needle in the left ventricle: report of a case with successful removal]. [ZASSHI] [JOURNAL]. NIHON KYOBU GEKA GAKKAI 1984; 32:1086-9. [PMID: 6501953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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343
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Ohshima S, Shibata T, Sasaki N, Okuda H, Nishizawa H, Ohsawa M, Matsumoto M, Nakayama E. [Subacute toxicity of an amine-curing agent for epoxy resin]. SANGYO IGAKU. JAPANESE JOURNAL OF INDUSTRIAL HEALTH 1984; 26:197-204. [PMID: 6521056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Amine-curing agent for epoxy resin, bis(4-amino-3-methylcyclohexyl)methane, has been suspected of inducing toxic symptoms in man which resemble collagen disease such as scleroderma or polymyositis. We studied subacute toxicity of this agent by repeated oral administrations to rats. The agent was administered 25, 37.5, 50, 75 or 100 mg/kg per one dose, 8 times in 10 days or 17 times in 4 weeks or 20-22 times in 4 weeks. When administration had been completed, clinical biochemical tests and histopathological examinations were carried out. Animals of high dosage group showed suppression of body weight increase and loss of muscular strength of limbs in the administration period. By clinical biochemical tests, elevation of blood components from muscle (CPK, GOT, creatine) was noticed. Also, increase of monoamine oxidase and decrease of alkaline phosphatase were revealed. By histological examinations, skeletal muscle and choroid plexus of brain showed noticeable changes. In muscles of high dosage group, atrophy, degeneration and regeneration of muscle fibers were observed and an increase of fibroblasts was also seen. In choroid plexus, vacuolar changes in epithelial cells were observed, being clearly dose-dependent. No particular change was recognized in skin. Though scleroderma-like change was not observed in the skin histologically, our results suggest that this amine-curing agent was greatly associated with muscle symptoms in the workers who handled epoxy resin and that it was one of causative agents which induced toxic symptoms like those of collagen disease.
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344
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Sakai A, Ohsawa M, Hoshino S, Ando M, Kurosawa H. [Tetralogy of Fallot with a conus defect associated with a common atrioventricular canal and atrioventricular discordance [IDN]. A case report]. [ZASSHI] [JOURNAL]. NIHON KYOBU GEKA GAKKAI 1984; 32:255-60. [PMID: 6747359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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345
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Abstract
A genetic study was carried out on 153 families with 186 Fukuyama type congenital progressive muscular dystrophy (FCMD) patients. Consanguineous marriage of parents was found in 41 families (26.80%). Inbreeding coefficients in the patients was 10 times as high as that of the general population. Both sexes were almost equally affected (M:F = 1.1:1.0). No single parent of the patients was affected. Recurrence among siblings was frequent (9 out of 41 siblings in offspring of related parents and 18 out of 110 siblings in offspring of unrelated parents were affected. The segregation ratio was 23.91-27.08% in offspring of related parents, 20.00-22.94% in offspring of unrelated parents, these values being not significantly different from the 25% expected from the assumption of autosomal recessive mode of inheritance. In the sample two twin pairs were included, of which one male isosexual pair was concordant. Sporadic cases were not significantly more numerous than expected. All these data indicate that the disorder is caused by homozygosity of an autosomal recessive gene. Frequency of the gene was estimated to be 5.2-9.7 X 10(-3) and frequency of the patients 6.9-11.9 X 10(-5). Mutation rate was estimated to be 6.9-11.9 X 10(-5).
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346
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Amano S, Ohsawa M, Hoshino S, Nishiguchi K. [Aortic regurgitation following closure of ventricular septal defect. Report of two cases with successful surgical treatment in early and late stages]. RINSHO KYOBU GEKA = JAPANESE ANNALS OF THORACIC SURGERY 1984; 4:66-70. [PMID: 6740144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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347
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Ochi T, Ishiguro T, Ohsawa M. Participation of active oxygen species in the induction of DNA single-strand scissions by cadmium chloride in cultured Chinese hamster cells. Mutat Res 1983; 122:169-75. [PMID: 6656808 DOI: 10.1016/0165-7992(83)90056-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A mechanism for the induction of DNA single-strand scissions in cultured Chinese hamster cells by cadmium chloride (CdCl2) was investigated by use of the technique of alkaline elution. Inducibility of DNA single-strand scissions by cadmium was examined under an aerobic or anaerobic culture condition. About 62% of the total cellular DNA was eluted throughout the filter within 10 h of elution time by treatment with 4 X 10(-5) M CdCl2 for 2 h in our usual aerobic medium. In contrast, no difference in elution profiles of DNA was observed between untreated control cells and the cells treated with CdCl2 in the anaerobic medium which was prepared by N2 gas bubbling of aerobic medium for 60 min. Furthermore, elution of DNA from cells treated with cadmium decreased markedly in the presence of superoxide dismutase (SOD) when compared with that in the absence of SOD. Inhibition of the cell growth by cadmium was significantly protected by the presence of SOD in the medium although the cell growth was not restored to the control level. These results indicate that active oxygen species participate in Cd-induced DNA single-strand scissions and also in the growth inhibition of the cells by the metal.
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348
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Ohsawa M, Kurita Y, Horie A, Kurita K. Malignant chemodectoma (paraganglioma) of the larynx. A case report with electron microscopy and biochemical assay. ACTA PATHOLOGICA JAPONICA 1983; 33:1279-88. [PMID: 6322512 DOI: 10.1111/j.1440-1827.1983.tb02173.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
This reports presents a case of malignant chemodectoma in the epiglottic region of a 47-year-old man. His initial complaint was laryngeal discomfort and he expired from generalized metastases of the tumor about one year after operation. The tumor was detected by laryngoscopy and laryngogram. The yellow parenchymatous tumor, 2.8 x 2.5 x 1.5 cm in size, was resected together with two enlarged regional lymph nodes. The mass was subjected to a histopathological study and biochemical assay. Microscopically, the tumor was located in the submucosa of the epiglottis and showed an alveolar growth pattern of comparatively uniform tumor cells. Neurosecretory granules were clearly demonstrated by Grimelius' method and by electron microscopy. The biochemical assay revealed that the tumor contained small amounts of serotonin, epinephrine, norepinephrine, and dopamine. The distribution of paraganglia as the source of these tumors, the clinicopathological review of the previous reports and significance of neurosecretory granules are discussed.
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349
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Ohsawa M, Sato K, Takahashi K, Ochi T. Modified distribution of lymphocyte subpopulation in blood and spleen from mice exposed to cadmium. Toxicol Lett 1983; 19:29-35. [PMID: 6606865 DOI: 10.1016/0378-4274(83)90258-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The effect of cadmium (Cd) on the lymphocyte subpopulation in peripheral blood and spleen was studied in ICR mice given a daily subcutaneous injection of 0.5 and 1.0 mg Cd/kg body weight for 5 days or mice fed with the drinking water containing 3, 30 and 300 ppm Cd for 10 weeks. The reduction of blood B lymphocytes observed in Cd-injected mice was accompanied by the increase of the number of splenic B lymphocytes. On the other hand in Cd-fed mice the reduction of blood T lymphocytes was found and associated with the increase of the number of splenic T lymphocytes. These findings suggest that circulating lymphocytes may redistribute differentially in lymphoid organs responded to the Cd exposure.
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350
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Ochi T, Ohsawa M. Induction of 6-thioguanine-resistant mutants and single-strand scission of DNA by cadmium chloride in cultured Chinese hamster cells. Mutat Res 1983; 111:69-78. [PMID: 6312300 DOI: 10.1016/0027-5107(83)90009-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Inducibility of 6-thioguanine-resistant (6TGr) mutants and single-strand scission of DNA by cadmium chloride (CdCl2) was investigated in cultured Chinese hamster V79 cells. Frequency of 6TGr mutants increased concentration dependently by 24-h treatment with CdCl2 up to 3 X 10(-6) M but decreased beyond 3 X 10(-6) M. Mutagenic potency of cadmium in the absence of S9 was about half that of benzo[a]pyrene in the presence of S9 at equitoxic concentrations. Treatment of the cultured cells with cadmium after benzo[a]pyrene treatment was not synergistic but additive to the mutagenicity of benzo[a]pyrene. Single-strand scission of DNA by alkaline elution techniques was observed in the cells treated with CdCl2 for 2 h in a concentration-dependent manner. The single-strand scission by cadmium was detected only in combination with proteinase K digestion of the cell lysates, indicating formation of DNA--protein cross-linking by the metal. These biological and biochemical findings indicate that cadmium is mutagenic in mammalian cells, and its mutagenic effect seems to be accompanied by single-strand scission of DNA.
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