Publications by authors named "Takako Muroi"

Background: Small mesenteric hiatal hernias (SMHHs) are defined as a small group of internal hernias (IHs) that frequently diagnosed in children. However, SMHHs are relatively rare in adults. Bowel loop herniation via an abnormal mesenteric defect can lead to strangulated intestinal obstruction.

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Occupational exposure to nickel oxide (NiO) is an important cause of respiratory tract cancer. Toxicity is known to be associated with the dissociated component, i.e.

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Lung metastasis of gastric cancer often presents as multiple pulmonary metastases or cancerous lymphadenopathy, which is rarely indicated for surgery and has a poor prognosis. We report a case of solitary metastases that were surgically resected. The patient underwent distal gastrectomy for stomach cancer and then received chemotherapy for abdominal lymph node metastasis.

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We have conducted animal toxicity tests of chemicals for a chemical safety program implemented by the Ministry of Economy, Trade and Industry of Japan. Here we conducted a combined repeated-dose and reproductive/developmental toxicity screening test of benzene, 1,1'-oxybis-, tetrapropylene derivs. (BOTD).

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We have carried out animal toxicity tests of chemicals for a chemical safety program implemented by the Ministry of Economy, Trade, and Industry of Japan. Here, we tested 1-tert-butoxy-4-chlorobenzene in a combined repeat-dose and developmental and reproductive toxicity test. The test chemical was administered daily by gavage to 9-week-old Crl:CD (SD) rats at doses of 0, 20, 100, and 500  mg/kg/d.

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4-Methoxy-2-nitroaniline (4M2NA) is widely used as an intermediate for the synthesis of dyes, pigments and other chemical compounds. Since 4M2NA has amino-group and nitro-group on the benzene ring, it was expected that it induced obvious hemolytic anemia. We conducted a combined repeated dose and reproductive/developmental toxicity screening test according to Organisation for Economic Co-operation and Development (OECD) Test Guideline No.

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Ethyl tertiary-butyl ether (ETBE) is commonly used as an oxygenated gasoline additive. In this study, we evaluated its developmental toxicity in rats. ETBE was administered by gavage to 21 or 22 pregnant female Sprague-Dawley rats per group at dose levels of 0, 100, 300 and 1000 mg/kg/day from days 5 through 19 postcoitum to assess its effects on pregnant animals and their embryos and fetuses applied to the OECD testing guideline (no.

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tert-Butylhydrazine monohydrochloride was daily administered by gavage to groups of Crl:CD (SD)IGS rats at doses of 0 (control), 0.8, 4, or 20 mg/kg/day. Twelve males per group were treated for a total of 42 days from 14 days before mating.

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We performed a uterotrophic assay, the Hershberger assay, and a 28-day repeated-dose toxicity study [enhanced Organization for Economic Co-operation and Development (OECD) test guideline No. 407] of 4,4'-butylidenebis(2-tert-butyl-5-methylphenol) and 3-(dibutylamino)phenol, based on the OECD draft protocols. In the uterotrophic assay of 4,4'-butylidenebis(2-tert-butyl-5-methylphenol), female SD rats were subcutaneously injected with the chemical at doses of 0, 100, 300, and 1,000 mg/kg on each of 3 days from postnatal day 20 to day 22, and no changes were observed.

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We performed an uterotrophic assay, the Hershberger assay, and a 28-day repeated-dose toxicity study (enhanced OECD test guideline No. 407) of 4,4 -[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bis[phenol] based on the OECD draft protocols. In the uterotrophic assay, female SD rats were subcutaneously injected with the chemical at doses of 0, 100, 300, and 1,000 mg/kg on each of 3 days from postnatal day 20 to day 22, and the uterine weight of rats given the 1,000 mg/kg dose of the test chemical plus ethinyl estradiol decreased.

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In vivo screening methods for detection of thyroid function modulators are now under development in many research laboratories. We assessed the applicability of the Hershberger assay protocol to screen for thyroid function modulators. In experiment 1, castrated male BrlHan WIST@Jcl (GALAS) rats were administered a potent thyroid peroxidase inhibitor, 3-amino-1,2,4-triazole (AT), in doses of 0, 40, 200, and 1,000 mg/kg/day with gravimetric endpoint, and in experiment 2, castrated and intact male rats were administered in doses of 0, 40, and 200 mg/kg/day, with quantification of the extent of hypertrophy of the thyroid epithelium, to assess the effects of castration, by gavage to 8-week-old for 10 consecutive days.

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In this preliminary study, the potential of an in utero-lactation assay to detect thyroid effectors was evaluated by treating three dams/group with 6-n-propyl-2-thiouracil (PTU), a known thyroid antagonist, by oral gavage at doses of 0, 0.0032, 0.016, 0.

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Pregnant CD (SD) IGS rats were given tamoxifen (TMX) orally at doses of 0.12, 0.6, or 3 microg/kg/day from gestational day 6 to postnatal day 21, and the effects of TMX exposure on all offspring were examined 10 weeks after birth; the reproductive performance of the offspring was also evaluated.

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Pregnant CD(SD) IGS rats were given flutamide (FLUT) orally at doses of 0.4, 2, or 10 mg/kg/day from gestational day 6 to postnatal day (PND) 20, and the effects of FLUT exposure on male offspring were examined 10 weeks after birth, and compared to the effects in offspring treated after weaning and in offspring untreated after weaning. Although the body weight of the dams treated with FLUT remained normal, two dams in the 10 mg/kg/day group were killed because of abnormal parturition periods and loss of all the pups.

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We performed the Hershberger assay of 12 chemicals based on the OECD draft protocol. The chemicals tested by the Hershberger assay were phthalic acid di-n-hexyl ester, phthalic acid di-n-amyl ester, phthalic acid di-n-propyl ester, diethylstilbestrol, 17beta-estradiol, tamoxifen, 5alpha-dihydrotestosterone, dichlorodiphenyldichloroethane, cyproterone acetate, 6alpha-methyl-17alpha-hydroxy-progesterone, atrazine, and spironolactone. Phthalic acid di-n-hexyl ester, phthalic acid di-n-amyl ester, and phthalic acid di-n-propyl ester are phthalates; diethylstilbestrol and 17beta-estradiol are estrogenic chemicals; tamoxifen is partial estrogen receptor antagonist with mainly estrogenic properties; 5alpha-dihydrotestosterone is an androgen derivatives; dichlorodiphenyldichloroethane is a reference androgen antagonistic chemical; cyproterone acetate, 6alpha-methyl-17alpha-hydroxy-progesterone, and spironolactone have an androgenic steroid structure and are known as androgen antagonistic chemicals; and atrazine is a reference endocrine disruptor.

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Most of the attention currently focused on endocrine-active chemicals is directed to their effects on the development of offspring exposed to them in utero or during the neonatal period. Pregnant Crj:CD(SD)IGS rats were given ethinyl estradiol (EE) orally in doses of 0.5-50 microg/kg/day from gestational day 7 to postnatal day 18, and their offspring were examined for its effects.

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As a preliminary trial of an in utero through lactational exposure protocol, ethinyl estradiol, 0, 0.5, 5, or 50 micro g/kg/day, was administered by gavage to pregnant Crj: CD (SD) IGS BR rats from gestational day (GD) 7 to day 18 after delivery to evaluate the efficacy of this protocol and to estimate optimal endpoints. The dams showed no abnormalities.

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The immature rat uterotrophic assay has been proposed as a screening test method for detecting estrogenic and antiestrogenic chemicals. Although the immature rat uterotrophic assay is advantageous because the test animals are not traumatized by the ovariectomizing process, the effect of endogenous estrogen on ovarian and uterine weight in the immature animals that are used in immature rat uterotrophic assay has not received much attention. In this study, 19-day-old rats were treated with antide, a gonadotropin-releasing hormone antagonist, antide, to block gonadal production of endogenous estrogen.

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