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The suppressive effects of cyclodextrins (CDs) on the strong estrogenic activity of 17β-estradiol (E2) in water environments were investigated in this study. Cyclodextrins are doughnut-shaped molecules that possess a hydrophobic cavity and a hydrophilic exterior. The cavity can incorporate nonpolar molecules as guests to form inclusion complexes. β-CD and 2-hydroxypropyl-β-CD (HP-β-CD) were the most successful in forming a complex with E2 and improving its low aqueous solubility. The E2/CDs complexes bound to the estrogen receptor in a cell-free system as determined by ELISA and suppressed the hormone activities as measured by a yeast two-hybrid assay. These results indicate that hydrophobic E2 is easily transported through the lipid zone of the plasma membrane into the target cell and can bind to the nuclear receptor. However, the hydrophilic E2/β-CD and E2/HP-β-CD complexes do not penetrate the membrane. Therefore, these CDs are able to suppress the hormone activity of E2 through complex formation. 相似文献
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Md. Abdul Halim Ratan K. Majumder Syeda Afsarun Nessa Keita Oda Yoshinario Hiroshiro Kenji Jinno 《Environmental monitoring and assessment》2010,161(1-4):453-472
Probable sources and mechanisms of arsenic (As) release in shallow aquifer in eastern Bangladesh are evaluated using statistical analysis of groundwater compositions. Dissolved As in 39 samples ranged from 8.05 to 341.5 μg/L with an average of 95.14 μg/L. Ninety seven percent of wells exceed the WHO limit (10 μg/L) for safe drinking water. Principal component analysis is applied to reduce 16 measured compositional variables to five significant components (principal components—PCs) that explain 86.63% of the geochemical variance. Two component loadings, namely PC 1 and PC 2 (45.31% and 23.05%) indicate the natural processes within the aquifers in which organic matter is a key reactant in the weathering reactions. Four groups of wells are defined by the PCA and each group of wells represents distinct physicochemical characteristics. Among them, group III groundwater shows higher As concentration together with high concentrations of Fe, Mn, dissolved organic carbon, $\text{PO}_{4}^{3-}$ and $\text{HCO}_{3}^{-}$ than groups I and II. Speciation calculations suggest that only wells of group III are saturated with respect to siderite, and all groups of samples are supersaturated with respect of rhodochrosite. The relationship of As with these parameters in the different groups of wells of the study area suggests that reductive dissolution of Fe–Mn oxyhydroxides with microbially mediated degradation of organic matter is considered to be the dominant processes to release As in groundwater. 相似文献
3.
Ryo Yamada Keita Kodama Takashi Yamakawa Toshihiro Horiguchi Ichiro Aoki 《Marine Biology》2007,151(3):961-971
We investigated the growth and reproductive biology of the penaeid shrimp Trachysalambria curvirostris in Tokyo Bay, Japan, by monthly bottom-trawl surveys from May 2002 to December 2004. We also examined oogenesis in T. curvirostris by histological observation of the ovary. Females grew faster and attained a larger body size for age than males. The growth
rate was high in summer and low in winter and was likely to be associated with seasonal changes in water temperature. The
carapace length (CL) at which 50% of females contained vitellogenic oocytes was estimated to be 17.0 mm. The reproductive
season extended from May to October. Young-of-the-year appeared in October and could be traced across the months on CL histograms
to the following September or October, indicating a 1-year life cycle. This extended reproductive season, together with our
observation of asynchronous development of oocytes in the ovary, suggests that multiple spawning by individual females may
occur during the reproductive season. Postovulated oocytes were not found among the samples we collected during the daytime,
suggesting that final oocyte maturation and spawning occur at night. Cortical crypts in the cytoplasm of the oocyte, considered
to be a general feature of oogenesis in penaeid shrimps, were not found in T. curvirostris, even in oocytes undergoing germinal vesicle breakdown. This result implies that the cortical reaction after spawning of
T. curvirostris may be different from that of other penaeid shrimps. 相似文献
4.
Kazuya Mimura Masayuki Endo Yoko Kawanishi Takeshi Kanagawa Kouji Nagata Keita Terui Makoto Fujii Masayuki Shiraishi Masaya Yamoto Miharu Ito Atsuo Itakura Hiroomi Okuyama Noriaki Usui the Japanese Congenital Diaphragmatic Hernia Study Group 《黑龙江环境通报》2023,43(8):993-1001
This systematic review and meta-analysis aimed to review the optimal timing of delivery at term for neonates with prenatally diagnosed congenital diaphragmatic hernia (CDH). We reviewed the literature up to December 19, 2022 using MEDLINE and the Cochrane Library databases. The inclusion criteria were original articles, comparative studies of CDH neonates delivered at an early term (37–38 weeks of gestation) and at full term (39 weeks of gestation or later), and comparative studies investigating outcomes of CDH neonates. Six studies met the inclusion criteria, including 985 neonates delivered at an early term and 629 delivered at full term. The cumulative rate of survival to discharge showed no significant difference between CDH neonates delivered at an early term (395/515; 76.7%) or at full term (345/467; 73.9%) (risk ratio [RR] 1.01; 95% confidence interval [CI], 0.89–1.16; p = 0.85). Furthermore, the number of neonates requiring oxygen therapy at discharge was not significantly different between CDH neonates delivered at an early term (32/370; 8.6%) and at full term (14/154; 9.1%) (RR, 0.99; 95% CI, 0.36–2.70; p = 0.99). Therefore, the optimal timing of delivery at term for neonates with CDH remains unclear. 相似文献
5.
Effects of Landscape Disturbance on Animal Communities in Lake Tanganyika, East Africa 总被引:1,自引:0,他引:1
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We developed a novel polymer type sulfoxide-modified solid phase enabling to achieve selective separation of polychlorinated biphenyls (PCBs) from insulation oil. In this study, firstly we prepared base-polymer based on the concept of the molecular imprinting to capture PCBs in selectively, then, the sulfoxide groups were modified on the pore surface of base-polymers by changing preparation methods. As results of liquid chromatographic analyses for the polymers as columns, the base-polymer prepared by xylene as a porogenic solvent showed selective retention ability for chlorinated aromatic compounds by the porogen imprinting effect. Additionally, the polymer-type sulfoxide solid phases showed highly retention ability for PCBs by increasing amount of introduced sulfoxide groups. Consequently, the results of separation of PCBs comparing to insulation oil suggested that the prepared solid phase can be used for the selective separation of PCBs at the same level as a commercially available media utilized for the regulated method. 相似文献
7.
Keita Furukawa 《Journal of Coastal Conservation》2014,18(3):273-277
On 26 March 2003, the Tokyo Bay Renaissance Promotion Council, composed of six central government agencies and eight regional government bodies endorsed an “Action Plan for Tokyo Bay Renaissance”. Under the action plan, the monitoring campaign of bay environment has been started in 2008. Dissolved oxygen (DO), salinity, and temperature were monitored in sea area, chemical oxygen demand, temperature, and discharge were monitored in river area. These data sets show a detailed snap shot of hypoxic water occurrence in the inner part of the bay. A series of environment maps for Tokyo Bay have been published for sharing the data. For example, in 2012, goby census has been implemented to show importance of biological – environmental relations. Participants of the census are 240, and the more than 8,000 data of fished gobies has been corrected. It clearly shows relation between growth and special environment variation. From just few trial of the campaigns are not enough to answer all questions, nevertheless, these trials shows its importance and efficiency on bay environment monitoring and management as one of the ICM tools. 相似文献
8.
Keita Kodama Hiroaki Shiraishi Masatoshi Morita Toshihiro Horiguchi 《Marine Biology》2006,150(1):131-140
To verify the lipofuscin-based age estimation of crustaceans of unknown age from wild populations, we conducted a modal analysis of lipofuscin-concentration histograms in the stomatopod Oratosquilla oratoria seasonally collected from Tokyo Bay, Japan. Confocal microscopy and subsequent image analysis were used to quantify lipofuscin concentrations in the protocerebral bridge cell mass in the brain. Conventional body length frequency analysis failed to detect modes corresponding to ≥1 year old. In contrast, four or five distinct modes were found in the lipofuscin-concentration histograms, in which modes could be readily traced across months, suggesting that each mode represented an independent age group. The lipofuscin accumulation rate fluctuated seasonally: it was high in summer (June–July) and low in winter (December–January). Cross-correlation analysis showed that the highest instantaneous lipofuscin accumulation rate was achieved in early summer before maximum bottom temperatures were reached and when the temperature was increasing most rapidly. Our findings support the usefulness of lipofuscin concentration analysis in age estimation in wild crustacean populations. 相似文献
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