Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Arch Toxicol ; 83(10): 941-6, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19533100

RESUMEN

4-Nonylphenol (para-nonylphenol, 4-NP), metabolites including linear and branched isoforms of nonylphenol (n-NP and t-NP, respectively), has been considered an endocrine disrupting substance resulting in reproductive dysfunction and increasing reactive oxygen species production in testis, liver, kidney, and brain. However, to date, whether vasculature is susceptible to NP exposure remains to be unclear. In this study, we have investigated the effects of chronic in vivo 4-n-NP exposure on vasoconstriction and vasorelaxation in male rats. After a 20-week 4-n-NP treatment orally at the dosage of 10 and 50 muM in the drinking water, phenylephrine- and potassium chloride-induced concentration-dependent responsiveness assessed by wire myograph were both significantly higher in aorta isolated from 4-n-NP-treated rats compared with control rats, but acetylcholine-induced vasorelaxation was similar between these two groups. In addition, systemic oxidative stress and vascular, but not intestinal, oxidant enzyme activities assessed by lucigenin-amplified chemiluminescence were all markedly higher in 4-n-NP-treated rats. In conclusion, our results suggested that chronic in vivo 4-n-NP exposure augments vascular contractile responsiveness through enhanced vascular oxidant enzyme activity.


Asunto(s)
Disruptores Endocrinos/farmacología , Fenoles/farmacología , Vasoconstricción/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Animales , Disruptores Endocrinos/administración & dosificación , Masculino , NADP/metabolismo , Fenoles/administración & dosificación , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Pruebas de Toxicidad Crónica , Xantina Oxidasa/metabolismo
2.
Environ Monit Assess ; 159(1-4): 207-16, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19011980

RESUMEN

In this study, a questionnaire survey of school drinking water quality of 42 schools in Pingtung County was conducted according to the water sources, treatment facilities, location of school as well as different grade levels. Among them, 45% of schools used tap water as the main source of drinking water, and the schools using groundwater and surface water as drinking water source account for 29% and 26%, respectively. The schools above senior high school level in the city used tap water as drinking water more than underground water, while the schools under junior high school level in the rural area used surface water as their main source of drinking water. The surface water was normally boiled before being provided to their students. The reverse osmosis system is a commonly used water treatment equipment for those schools using tap water or underground water. Drinking fountain or boiled water unit is widely installed in schools above senior high school level. For schools under junior high school level, a pipeline is stretched across the campus. Relative test shows that the unqualified rate of microbe in water is 26.2%. All parameters for physical and chemical properties and metal content had met the domestic standards except that the turbidity of schools under junior high school level using tap water is slightly higher than the standard value.


Asunto(s)
Instituciones Académicas , Abastecimiento de Agua/análisis , Agua/análisis , Taiwán , Contaminantes Químicos del Agua/análisis
3.
J Nat Prod ; 71(6): 1016-21, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18471021

RESUMEN

Four new compounds, including two new dihydroagarofuranoid sesquiterpenes, 8-benzoyloxymutangin (1) and 15-acetoxyorbiculin G (2), a new lignan derivative, 9,9'- O-di-(Z)-feruloyl-(-)-secoisolariciresinol (3), and a new benzenoid, 5'-methoxyevofolin B (4), have been isolated from the stem of Microtropis japonica, together with 20 known compounds (5- 24). 3-Ethoxy-4-hydroxybenzaldehyde (5) was identified from a natural source for the first time. The structures of these new compounds were determined through analyses of physical data. 15-Acetoxyorbiculin G (2), celahin C (6), and salasol A (7) exhibit antituberculosis activities (MICs < or = 39.6 microM) against Mycobacterium tuberculosis H 37Rv in vitro.


Asunto(s)
Antituberculosos/aislamiento & purificación , Antituberculosos/farmacología , Derivados del Benceno/aislamiento & purificación , Derivados del Benceno/farmacología , Celastraceae/química , Lignanos/aislamiento & purificación , Lignanos/farmacología , Plantas Medicinales/química , Sesquiterpenos/aislamiento & purificación , Sesquiterpenos/farmacología , Antituberculosos/química , Derivados del Benceno/química , Lignanos/química , Estructura Molecular , Mycobacterium tuberculosis/efectos de los fármacos , Tallos de la Planta/química , Sesquiterpenos/química , Taiwán
4.
Sci Total Environ ; 636: 464-476, 2018 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-29709864

RESUMEN

We assessed 22 selected endocrine-disrupting compounds (EDCs) and other emerging, potentially endocrine-active compounds with estrogenic activity from the waters of the Wuluo River, southern Taiwan. This watershed receives high amounts of livestock and untreated household wastewaters. The river is surrounded by concentrated animal feedlot operations (CAFOs). River water samples were analyzed for selected compounds by liquid chromatography-tandem mass spectrometry (LC-MS/MS), T47D-KBluc reporter gene assay, and E-screen cell proliferation in vitro bioassay. Total concentrations of ∑alkylphenolic compounds (bisphenol A, 4-nonylphenol, t-nonylphenol, octylphenol, nonylphenol mono-ethoxylate, nonylphenol di-ethoxylate) were much higher than ∑estrogens (estrone, 17 ß-estradiol, estriol, 17ß-ethynylestradiol, diethylstilbestrol), ∑preservatives (methyl paraben, ethyl paraben, propyl paraben, butyl paraben), ∑UV-filters (benzophenone, methyl benzylidene camphor, benzophenone-3), ∑antimicrobials (triclocarben, triclosan, chloroxylenol), and an insect repellent (diethyltoluamide) over four seasonal sampling periods. The highest concentration was found for bisphenol A with a mean of 302 ng/L. However, its contribution to estrogenic activity was not significant due to its relatively low estrogenic potency. Lower detection rates were found for BP, EE2, TCS, and PCMX, while DES and EP were not detected. E1 and E2 levels in raw water samples were 50% higher than the predicted no-effect concentrations (PNEC) for aquatic organisms of 6 and 2 ng/L, respectively. The potency of estrogenic activity ranged from 11.7 to 190.1 ng/L E2T47D-Kbluc and 6.63 to 84.5 ng/L E2E-Screen for extracted samples. Importantly, estrone contributed 50% of the overall activity in 60% and 44% of the samples based on T47D-KBluc and MCF-7 bioassays, followed by 17 ß-estradiol, highlighting the importance of total steroid estrogen loading. This study demonstrates that the estrogenic activity of target chemicals was comparable to levels found in different countries worldwide. More intense wastewater treatment is required in areas of intensive agriculture in order to prevent adverse impacts on the ambient environment and aquatic ecosystems.


Asunto(s)
Crianza de Animales Domésticos , Disruptores Endocrinos/análisis , Monitoreo del Ambiente , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisis , Animales , Estrógenos , Ganado , Ríos , Taiwán , Aguas Residuales/estadística & datos numéricos
5.
J Vet Med Sci ; 76(7): 971-5, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24694943

RESUMEN

Alkylphenol polyethoxylate (APEO) derivatives, such as nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), nonylphenol (NP) and octylphenol (OP), have been detected in the surface water, sediment, food and groundwater of numerous countries. Because groundwater is the main source of water for pig herds, the aim of this study was to measure the concentrations of APEO derivatives in groundwater and blood samples that were collected from pig herds raised near the Wuluo River in Southern Taiwan. The mean concentrations of NP, OP, NP1EO and NP2EO in the groundwater supply for 10 pig herds were 0.04 µg/l, 0.26 ± 0.23 µg/l, 0.74 ± 0.69 µg/l and 0.17 ± 0.22 µg/l, respectively. NP was detected in all blood samples collected from 5 of the 10 pig herds. The highest concentrations detected in the blood samples collected from six-week-old piglets and sows were 12.00 µg/l and 56.94 µg/l, respectively. Blood samples from 4 of the 5 herds showed OP contamination. The highest OP concentrations detected in 6-week-old piglets and sows were 275.58 µg/l and 566.32 µg/l, respectively. These results indicate that APEO derivatives accumulated in the groundwater supply and the bloodstreams of the pigs.


Asunto(s)
Contaminantes Ambientales/sangre , Contaminantes Ambientales/química , Agua Subterránea/química , Polietilenglicoles/química , Porcinos/sangre , Animales , Monitoreo del Ambiente , Taiwán
6.
Bioorg Med Chem ; 15(20): 6527-34, 2007 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-17689252

RESUMEN

Certain oxime- and amide-containing quinolin-2(1H)-one derivatives were synthesized and evaluated for their antiproliferative and antiplatelet activities. These compounds were synthesized via alkylation of hydroxyl precursors followed by the reaction with NH(2)OH or NaN(3) (Schmidt reaction). The preliminary assays indicated that amide derivatives are either weakly active or inactive while the oxime counterparts exhibited potent inhibitory activities against platelet aggregation induced by collagen, AA (arachidonic acid), and U46619 (the stable thromboxan A(2) receptor agonist). Among them, (Z)-6-[2-(4-methoxyphenyl)-2-hydroxyiminoethoxy]quinolin-2(1H)-one (7c) was the most active against AA induced platelet aggregation with an IC(50) of 0.58microM and was inactive against cell proliferation. For the inhibition of U46619 induced aggregation, 7a and 8a-c exhibited very potent activities with IC(50) values in a range between 0.54 and 0.74microM. For the antiproliferative evaluation, N-(biphenyl-4-yl)-2-(2-oxo-1,2-dihydroquinolin-7-yloxy)acetamide (11d) was the most potent with GI(50) values of <10, 10.8, and <10microM against the growth of MT-2, NCI-H661, and NPC-Tw01, respectively, and possessed only a weak antiplatelet activity. Further evaluation of 11d as a potential anticancer agent is on-going.


Asunto(s)
Amidas/química , Oximas/química , Agregación Plaquetaria/efectos de los fármacos , Quinolinas/química , Quinolinas/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Concentración 50 Inhibidora , Quinolinas/síntesis química , Relación Estructura-Actividad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA