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Nariaki Fujimoto

Bio: Nariaki Fujimoto is an academic researcher from Hiroshima University. The author has contributed to research in topics: Thyroid & Estrogen receptor. The author has an hindex of 21, co-authored 97 publications receiving 2805 citations.


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Journal ArticleDOI
TL;DR: The results suggest that the 4-hydroxyl group of the A- phenyl ring and the B-phenyl ring of BPA derivatives are required for these hormonal activities, and substituents at the 3,5-positions of the phenyl rings and the bridging alkyl moiety markedly influence the activities.

652 citations

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TL;DR: The results suggest that TBBPA and TCBPA act as thyroid hormone agonists, as well as estrogens.

313 citations

Journal ArticleDOI
TL;DR: Results suggest that a 4-hydroxyl group on the phenyl ring of benzophenone derivatives is essential for high hormonal activities, and the presence of other hydroxyl groups markedly alters these activities.

312 citations

Journal ArticleDOI
TL;DR: TBBPA, TCBPA, TMBPA and DMBPA can act as thyroid hormone-disrupting agents, and TBBPA showed suppressive action on T3 (5 x 10(-8) M)-enhancement of Rana rugosa tadpole tail shortening.

202 citations

Journal ArticleDOI
TL;DR: It is confirmed that liver tumor is testosterone‐responsive and hormonal manipulation by surgical orchidectomy or by chemical orchid surgery, or by leuprorelin, could substantially prevent the appearance of liver tumors.
Abstract: The prevalence of liver tumors throughout the world makes it imperative to seek chemopreventive agents. This tumor appears to be hormone-responsive and hormonal manipulations may therefore be beneficial. On this basis, both sexes of 12-day-old B6C3F(1) mice were injected i.p. with diethylnitrosamine (DEN) at the dose of 2.5 mg / g body weight and observed for 32 weeks (males) or 36 weeks (females). In 100% of male mice, liver tumors were observed with an average diameter of 2.72 mm and multiplicity of 60.8. Orchidectomy at 6 weeks of age in these mice inhibited the incidence, multiplicity and size to 63%, 5.6 and 1.54 mm, respectively. By further implantation with an E(2) pellet at monthly intervals, these parameters were reduced to 26%, 0.6 and 0.61 mm, respectively. Administration of a gonadotropin-blocking chemical, leuprorelin, to DEN-treated male mice significantly reduced the multiplicity and size of tumors to 18.3 and 2.54 mm (P < 0.01 compared to those of DEN only). In female mice, the incidence of liver tumor was significantly smaller than that of males. However, ovariectomy and / or testosterone supplement significantly increased the occurrence of liver tumor. An anti-estrogen, toremifene, caused a marked further decrease of liver tumors. Mitotic indices with bromodeoxyuridine in tumor tissues paralleled the occurrence of liver tumors. Serum testosterone levels were significantly reduced by orchidectomy or by leuprorelin administration. These results further confirm that liver tumor is testosterone-responsive and hormonal manipulation by surgical orchidectomy or by chemical orchidectomy i.e. by leuprorelin, could substantially prevent the appearance of liver tumors.

128 citations


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01 Jan 2000
TL;DR: This annex is aimed at providing a sound basis for conclusions regarding the number of significant radiation accidents that have occurred, the corresponding levels of radiation exposures and numbers of deaths and injuries, and the general trends for various practices, in the context of the Committee's overall evaluations of the levels and effects of exposure to ionizing radiation.
Abstract: NOTE The report of the Committee without its annexes appears as Official Records of the General Assembly, Sixty-third Session, Supplement No. 46. The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The country names used in this document are, in most cases, those that were in use at the time the data were collected or the text prepared. In other cases, however, the names have been updated, where this was possible and appropriate, to reflect political changes. Scientific Annexes Annex A. Medical radiation exposures Annex B. Exposures of the public and workers from various sources of radiation INTROdUCTION 1. In the course of the research and development for and the application of atomic energy and nuclear technologies, a number of radiation accidents have occurred. Some of these accidents have resulted in significant health effects and occasionally in fatal outcomes. The application of technologies that make use of radiation is increasingly widespread around the world. Millions of people have occupations related to the use of radiation, and hundreds of millions of individuals benefit from these uses. Facilities using intense radiation sources for energy production and for purposes such as radiotherapy, sterilization of products, preservation of foodstuffs and gamma radiography require special care in the design and operation of equipment to avoid radiation injury to workers or to the public. Experience has shown that such technology is generally used safely, but on occasion controls have been circumvented and serious radiation accidents have ensued. 2. Reviews of radiation exposures from accidents have been presented in previous UNSCEAR reports. The last report containing an exclusive chapter on exposures from accidents was the UNSCEAR 1993 Report [U6]. 3. This annex is aimed at providing a sound basis for conclusions regarding the number of significant radiation accidents that have occurred, the corresponding levels of radiation exposures and numbers of deaths and injuries, and the general trends for various practices. Its conclusions are to be seen in the context of the Committee's overall evaluations of the levels and effects of exposure to ionizing radiation. 4. The Committee's evaluations of public, occupational and medical diagnostic exposures are mostly concerned with chronic exposures of …

3,924 citations

Journal ArticleDOI
TL;DR: The evidence that endocrine disruptors have effects on male and female reproduction, breast development and cancer, prostate cancer, neuroendocrinology, thyroid, metabolism and obesity, and cardiovascular endocrinology is presented.
Abstract: Thereisgrowinginterestinthepossiblehealththreatposedbyendocrine-disruptingchemicals (EDCs), which are substances in our environment, food, and consumer products that interfere with hormone biosynthesis, metabolism, or action resulting in a deviation from normal homeostatic control or reproduction. In this first Scientific Statement of The Endocrine Society, we present the evidence that endocrine disruptors have effects on male and female reproduction, breast development and cancer, prostate cancer, neuroendocrinology, thyroid, metabolism and obesity, and cardiovascular endocrinology. Results from animal models, human clinical observations, and epidemiological studies converge to implicate EDCs as a significant concern to public health. The mechanisms of EDCs involve divergent pathways including (but not limited to) estrogenic, antiandrogenic, thyroid, peroxisome proliferator-activated receptor , retinoid, and actions through other nuclear receptors; steroidogenic enzymes; neurotransmitter receptors and systems; and many other pathways that are highly conserved in wildlife and humans, and which can be modeled in laboratory in vitro and in vivo models. Furthermore, EDCs represent a broad class of molecules such as organochlorinated pesticides and industrial chemicals, plastics and plasticizers, fuels, and many other chemicals that are present in the environment or are in widespread use. We make a number of recommendations to increase understanding of effects of EDCs, including enhancing increased basic and clinical research, invoking the precautionary principle, and advocating involvement of individual and scientific society stakeholders in communicating and implementing changes in public policy and awareness. (Endocrine Reviews 30: 293–342, 2009)

3,576 citations

Journal ArticleDOI
TL;DR: The present overview highlights the waste management and pollution challenges, emphasising on the various chemical substances contained in all plastic products for enhancing polymer properties and prolonging their life.

1,740 citations

Journal ArticleDOI
06 Jul 2007-Science
TL;DR: It is proposed that estrogen-mediated inhibition of IL-6 production by KCs reduces liver cancer risk in females, and these findings may be used to prevent HCC in males.
Abstract: Hepatocellular carcinoma (HCC), the most common liver cancer, occurs mainly in men. Similar gender disparity is seen in mice given a chemical carcinogen, diethylnitrosamine (DEN). DEN administration caused greater increases in serum interleukin-6 (IL-6) concentration in males than it did in females. Furthermore, ablation of IL-6 abolished the gender differences in hepatocarcinogenesis in mice. DEN exposure promoted production of IL-6 in Kupffer cells (KCs) in a manner dependent on the Toll-like receptor adaptor protein MyD88, ablation of which also protected male mice from DEN-induced hepatocarcinogenesis. Estrogen inhibited secretion of IL-6 from KCs exposed to necrotic hepatocytes and reduced circulating concentrations of IL-6 in DEN-treated male mice. We propose that estrogen-mediated inhibition of IL-6 production by KCs reduces liver cancer risk in females, and these findings may be used to prevent HCC in males.

1,712 citations

Journal ArticleDOI
TL;DR: Scientific issues associated with the use of tetrabromobisphenol A, hexabromocyclodododecane, and three commercial mixtures of polybrominated diphenyl ethers are reviewed and data gaps are discussed.
Abstract: Brominated flame retardants (BFRs) have routinely been added to consumer products for several decades in a successful effort to reduce fire-related injury and property damage. Recently, concern for this emerging class of chemicals has risen because of the occurrence of several classes of BFRs in the environment and in human biota. The widespread production and use of BFRs; strong evidence of increasing contamination of the environment, wildlife, and people; and limited knowledge of potential effects heighten the importance of identifying emerging issues associated with the use of BFRs. In this article, we briefly review scientific issues associated with the use of tetrabromobisphenol A, hexabromocyclododecane, and three commercial mixtures of polybrominated diphenyl ethers and discuss data gaps. Overall, the toxicology database is very limited; the current literature is incomplete and often conflicting. Available data, however, raise concern over the use of certain classes of brominated flame retardants.

1,593 citations