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排序方式: 共有362条查询结果,搜索用时 31 毫秒
1.
Masaru Kubota Ying-Wei Lin Keigo Hamahata Machiko Sawada Seiji Koishi Haruyo Hirota Yoshihiro Wakazono 《Mutation Research - Genetic Toxicology and Environmental Mutagenesis》2000,470(2):21
The occurrence of a second neoplasm is one of the major obstacles in cancer chemotherapy. The elucidation of the genotoxic effects induced by anti-cancer drugs is considered to be helpful in identifying the degree of cancer risk. Numerous investigations on cancer patients after chemotherapy have demonstrated: (i) an increase in the in vivo somatic cell mutant frequency (Mf) at three genetic loci, including hypoxanthine–guanine phosphoribosyl-transferase (hprt), glycophorin A (GPA), and the T-cell receptor (TCR), and (ii) alterations in the mutational spectra of hprt mutants. However, the time required for and the degree of such changes are quite variable among patients even if they have received the same chemotherapy, suggesting the existence of underlying genetic factor(s). Accordingly, some cancer patients prior to chemotherapy as well as patients with cancer-prone syndrome have been found to show an elevated Mf. Based on the information obtained from somatic cell mutation assays, an individualized chemotherapy should be considered in order to minimize the risk of a second neoplasm. 相似文献
2.
Yuichi Esaki Kenji Obayashi Keigo Saeki Kiyoshi Fujita Nakao Iwata Tsuyoshi Kitajima 《Chronobiology international》2020,37(6):887-896
ABSTRACT Previous studies have found that keeping the room dark at night was associated with a decrease in manic symptoms for patients with bipolar disorder (BD). However, the association between light at night of real-life conditions and manic symptoms is unclear. We investigated the association between bedroom light exposure at night and manic symptoms in BD patients. One-hundred and eighty-four outpatients with BD participated in this cross-sectional study. The average light intensity at night during sleep was evaluated using a portable photometer for seven consecutive nights. Manic symptoms were assessed using the Young Mania Rating Scale (YMRS), and scores ≥5 were treated as a “hypomanic state.” The median (interquartile range) YMRS score was 2.0 (0–5.0), and 52 (28.2%) participants were in a hypomanic state. The prevalence of a hypomanic state was significantly higher in the participants with an average light intensity at night exposure of ≥3 lux than in those with <3 lux (36.7% versus 21.9%; P = .02). In multivariable logistic regression analysis adjusted for BD type, depressive symptoms, sleep duration, and daytime physical activity, the odds ratio (OR) for a hypomanic state was significantly higher for the participants with an average light intensity at night exposure of ≥3 lux than for those with <3 lux (OR: 2.15, 95% confidence interval: 1.09–4.22, P = .02). This association remained significant at the cutoff value of YMRS score ≥6 (OR: 2.51, 95% confidence interval: 1.15–5.46; P = .02). The findings of this study indicate bedroom light exposure at night is significantly associated with manic symptoms in BD patients. Although the results of this cross-sectional investigation do not necessarily imply causality, they may serve to inform beneficial nonpharmacological intervention and personalized treatment of BD patients. 相似文献
3.
Dietary inhibitors of mutagenesis and carcinogenesis 总被引:12,自引:0,他引:12
Dietary inhibitors of mutagenesis and carcinogenesis are of particular interest because they may be useful for human cancer prevention. Several mutagenesis inhibitors have been demonstrated to be carcinogenesis inhibitors also, e.g., ellagic acid, palmitoleic acid, and N-acetylcysteine. This means that the search for mutagenesis inhibitors may be useful for discovering anticarcinogenic agents. Many mutagenesis inhibitors have been discovered by the use of short-term assays, particularly the Ames Salmonella test. This simple in vitro system has provided opportunities to elucidate the mechanisms of inhibition. The elucidation of the mechanism may allow us to infer the possible anticarcinogenic activity of the reagent. In this chapter, inhibitors of mutagenesis and carcinogenesis that can arise as components of diet have been reviewed. Most of the inhibitors have been demonstrated to be effective against a specific class of mutagens or carcinogens. Therefore, it may be argued that these inhibitors are antagonistic only to those particular agents. Here again, understanding of the mechanisms of these inhibitions is necessary for the assessment. Dietary inhibitors reviewed in this article include: (1) as inhibitors of mutagenesis: porphyllins, fatty acids, vitamins, polyphenols, and sulfhydryl compounds, (2) as inhibitors of carcinogenesis: vitamins A, E and C, ellagic acid, sulfhydryl compounds, fats, selenium, calcium, and fiber. Further studies in this area of science appear to help establish the recipe of a healthy diet. 相似文献
4.
Adsorption of mutagens to cotton bearing covalently bound trisulfo-copper-phthalocyanine 总被引:2,自引:0,他引:2
H Hayatsu T Oka A Wakata Y Ohara T Hayatsu H Kobayashi S Arimoto 《Mutation research》1983,119(3):233-238
A method for separating nonpolar mutagens from their dilute aqueous solutions is described. It utilizes the affinity of the mutagens to a phthalocyanine derivative attached to cotton through a covalent bond. For mutagens having 3 or more fused aromatic rings in their structures, efficient adsorption took place on soaking the cotton in their solutions. The mutagens adsorbed can be recovered by elution with ammoniacal methanol. Mutagenicity in smoker's urine, cooked beef, and river water was detected by use of this method. 相似文献
5.
Kazuki Sugawara Hidekazu Suzuki Mitsunobu Kamiya Keigo Osada Andrzej Witkowski 《Phycological Research》2023,71(4):182-192
The canal-bearing diatom genus Nagumoea, described based on only morphological evidence, was tentatively assigned to the order Bacillariales, although its phylogenetic position remained unclear. Because three isolates of Nagumoea (SK002, SK024 and SK053) were successfully established from Japanese coasts, we performed their morphological observations and molecular phylogenetic analyses to discuss the phylogeny and taxonomic position of this genus. Strains SK002 and SK024 were identified as Nagumoea africana, whereas SK053 conformed with Nagumoea serrata. There was high interspecific divergence between N. africana and N. serrata in the rbcL sequences (8.03–8.17%), indicating their distinctness. Furthermore, intraspecific variations were detected within N. africana (2.35%) in the rbcL, implying its cryptic diversity. The maximum likelihood and Bayesian phylogenetic trees inferred from the plastid rbcL, psbC and nuclear 18S rDNA genes recovered Nagumoea as monophyletic with strong statistical support and embedded within an unresolved, poorly supported lineage containing Achnanthes, Craspedostauros, Staurotropis and Undatella in the canal-bearing order Bacillariales (= the family Bacillariaceae). Although the constrained tree based on the monophyly of Nagumoea and the other canal-bearing clade (Surirellales and Rhopalodiales) was statistically rejected by the topology tests, the phylogenetic position of Nagumoea with other Bacillarialean members remains equivocal. The possession of two plastids positioned fore and aft, observed in the present study, and lack of keel, typical of the Bacillariales, indicate the possibility of Nagumoea being part of the ingroup of the Bacillariales or its closely related outgroup. 相似文献
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8.
The hemolymph of the hard clam, Mercenaria mercenaria, was found to agglutinate nonspecifically 4 of the 30 bacteria tested and a marine alga. The agglutinin is a protein (or a conjugated protein) because it is: (1) precipitated by trichloroacetic acid and ammonium sulfate; (2) inactivated by extraction with chloroform, but not with toluene or xylene; and (3) inactivated by chymotrypsin and protease, but not by deoxyribonuclease. Electrophoretic analysis shows that the agglutinin is composed of subunits each with a molecular weight of approximately 21,000. Calcium ions are required for the activity of the agglutinin and contribute to the heat stability of the molecule. Several saccharides, which may constitute a portion of the bacterial agglutinin receptors, were capable of partially inhibiting agglutination. In vitro studies using clam hemocytes showed that the phagocytosis of a marine bacterium, designated as RS-005, was enhanced by the presence of hemolymph. Adsorption of hemolymph samples with RS-005 bacteria removed the agglutinin activity for all types of cells tested and also abolished the opsonic effect. 相似文献
9.
Keigo Gohda 《Journal of enzyme inhibition and medicinal chemistry》2013,28(5):609-615
In this study, we investigated by linear regression model the SAR data of the 15 HIV-1 protease inhibitors possessing structurally diverse scaffolds. First, a regression model was developed only using the enzyme-inhibitor interaction energy as a term of the model, but did not provide a good correlation with the inhibitory activity (R2 = 0.580 and Q2 = 0.500). Then, we focused on the conformational flexibility of the inhibitors which may represent the diversity of the inhibitors, and added two conformational parameters into the model, respectively: the number of rotatable bonds of ligands (ΔSrot) and the distortion energy of ligands (ΔElig). The regression model by adding ΔElig successfully improved the quality of the model (R2 = 0.771 and Q2 = 0.713) while the model with ΔSrot was unsuccessful. The prediction for a training inhibitor by the ΔElig model also showed good agreement with experimental activity. These results suggest that the conformational flexibility of HIV-1 protease inhibitors directly contributes to the enzyme inhibition. 相似文献
10.
Shinsuke Mikami Ayumu Nakashima Keigo Nakagawa Tatsuya Maruhashi Yumiko Iwamoto Masato Kajikawa Takeshi Matsumoto Yasuki Kihara Kazuaki Chayama Kensuke Noma Mitsuo Ochi Masahiro Nishimura Koichiro Tsuji Yukio Kato Chikara Goto Yukihito Higashi 《PloS one》2013,8(7)