15 resultados para Sult


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Mode of access: Internet.

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Cytosolic sulfotransferases are believed to play a role in the neuromodulation of certain neurotransmitters and drugs. To date, four cytosolic sulfotransferases have been shown to be expressed in human brain. Recently, a novel human brain sulfotransferase has been identified and characterized, although its role and localization in the brain are unknown. Here we present the first immunohistochemical (IHC) localization of SULT4A1 in human brain using an affinity-purified polyclonal antibody raised against recombinant human SULT4A1. These results are supported and supplemented by the IHC localization of SULT4A1 in rat brain. In both human and rat brains, strong reactivity was found in several brain regions, including cerebral cortex, cerebellum, pituitary, and brainstem. Specific signal was entirely absent on sections for which preimmune serum from the corresponding animal, processed in the same way as the postimmune serum, was used in the primary screen. The findings from this study may assist in determining the physiological role of this SULT isoform.

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Sulfotransferases (SULTs) catalyse the sulfonation of both endogenous and exogenous compounds including hormones, catecholamines. drugs and xenobiotics. While in most occasions, sulfonation is a detoxication pathway. in the case of certain drugs and carcinogens. it leads to metabolic activation. Since, the rabbit has been extensively used for both pharmacological and toxicological studies, the purpose of this study was to further characterise the sulfotransferase system of this animal. In the present study, a novel sulfotransferase isoform (GenBank Accession no. AF360872) was isolated from a rabbit liver cDNA lambdaZAP 11 library. The full-length sequence of the clone was 1138 bp long and contained a coding region of 888 bp encoding a cytosolic protein of 295 amino acids (deduced molecular weight 34,193 Da). The amino acid sequence of this novel SULT isoform showed >70% identity with members of the SULT1A subfamily of sulfotransferases from other species. Upon expression of the encoded rabbit sulfotransferase in Escherchia coli (E. coli), it was shown that the enzyme was capable of sulfonating both p-nitrophenot (K-m and V-max values of 0.15 muM and 897.5 nmol/min/mg protein. respectively) and dopamine (K-m and V-max values of 175.3 muM and 151.1 nmol/min/mg protein, respectively). Based on the sequence data obtained and substrate specificity, this new rabbit sulfotransferase was named rabSULT1A1. Immunoblotting was used to demonstrate that rabSULT1A1 protein is expressed in liver, duodenum, jejunum, ileum, colon and recturm. (C) 2002 Elsevier Science Ltd. All rights reserved.

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Sinkin valmistuksessa pitää sinkkirikasteesta poistaa epäpuhtausmetallit ennen elektrolyysiä. Nykyisin epäpuhtauksien poistamiseksi käytetään sementointimene-telmiä. Sementointi voisi olla mahdollista korvata kelatoivalla adsorbentilla suori-tettavalla erotuksella, jonka etuja ovat selektiivisyys ja ympäristöystävällisyys. Työn tarkoituksena on tutkia lämpötilan vaikutusta kelatoivalla adsorbentilla teh-tävään nikkelin ja kuparin kolonnierotukseen. Kolonnierotuksessa lämpötila voi vaikuttaa sekä liuoksen että adsorbentin fysi-kaalisiin, kemiallisiin ja sähkökemiallisiin ominaisuuksiin. Näiden vaikutusten johdosta voivat esimerkiksi erotuksen stoikiometria, kinetiikka tai toimintaolosuh-teet muuttua. Tässä työssä lämpötilan vaikutusta kolonnierotukseen tutkittiin rik-kihapon ja erotusmateriaalin välisillä kinetiikkakokeilla sekä synteettisellä CuSO4-liuoksella ja autenttisella ZnSO4-liuoksella tehdyillä kolonniajoilla. Työssä käytetyn erotusmateriaalin runko on silikapolyamiini ja sen funktionaali-sena ryhmänä toimii 2-aminometyylipyridiini. Lämpötilan ollessa 60 °C havaittiin erotusmateriaalin ja rikkihapon asettuvan tasapainoon kolme kertaa nopeammin kuin 25 °C:ssa. Lämpötilan nostamisella edelleen 90 °C:een ei havaittu olevan merkittävää vaikutusta tasapainon saavuttamisen nopeuteen. Kuparin läpäisykäyrän havaittiin jyrkentyvän lämpötilan noston vaikutuksesta niin autenttisella ZnSO4-liuoksella kuin synteettisellä CuSO4-liuoksella. Tämän oletettiin johtuvan kinetiikan nopeuden kasvusta sekä autenttisella liuoksella myös viskositeetin pienenemisestä. Lämpötilan vaikutuksesta on mahdollista käsitellä autenttista ZnSO4-liuosta 90 °C:ssa noin 3,5-kertaa enemmän kuin 25 °C:ssa, siten että liuoksesta saadaan poistettua lähes kaikki kupari. Nikkelin havaittiin lä-päisevän kolonnin kaikissa lämpötiloissa lähes välittömästi. Tästä syystä tutkittu erotusmateriaali ei sovellu nikkelin ja kuparin samanaikaiseen erottamiseen tutki-tusta autenttisesta ZnSO4-liuoksesta.

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Pelvic pain is a common indication for ultrasound examinations in female pediatric patients. Many pathological processes affect the female pelvis in childhood. Knowledge of the normal ultrasound appearance of the pelvic organs is the basis for the recognition of pathologic findings. Pelvic pain in children is a nonspecific clinical finding often prompting use of ultrasound. Other indications for pelvic ultrasound in female children include workup of cysts seen on fetal ultrasound, urogenital malformations in newborns, precocious puberty, vaginal discharge or abnormal bleeding, and amenorrhea. Knowledge of differential diagnosis for disease processes of the female pelvic organs is essential. Ultrasound is the imaging modality of choice for evaluating the pediatric female pelvis.

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Added t.p.: Le diwan d'Amroʼlkaïs,prʹecʹdʹe de la vie de ce poète par l'auteur du Kitab el-aghani accompagnʹe d'une traduction et de notes par Le Bon. Mac Guckin de Slane.

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Mode of access: Internet.

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Sulfonation is an important reaction in the metabolism of numerous xenobiotics, drugs, and endogenous compounds. A supergene family of enzymes called sulfotransferases (SULTs) catalyze this reaction. In most cases, the addition of a sulfonate moiety to a compound increases its water solubility and decreases its biological activity. However, many of these enzymes are also capable of bioactivating procarcinogens to reactive electrophiles. In humans three SULT families, SULT1, SULT2, and SULT4, have been identified that contain at least thirteen distinct members. SULTs have a wide tissue distribution and act as a major detoxification enzyme system in adult and the developing human fetus. Nine crystal structures of human cytosolic SULTs have now been determined, and together with site-directed mutagenesis experiments and molecular modeling, we are now beginning to understand the factors that govern distinct but overlapping substrate specificities. These studies have also provided insight into the enzyme kinetics and inhibition characteristics of these enzymes. The regulation of human SULTs remains as one of the least explored areas of research in the field, though there have been some recent advances on the molecular transcription mechanism controlling the individual SULT promoters. Interindividual variation in sulfonation capacity may be important in determining an individual's response to xenobiotics, and recent studies have begun to suggest roles for SULT polymorphism in disease susceptibility. This review aims to provide a summary of our present understanding of the function of human cytosolic sulfotransferases.

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A type of macro drainage solution widely used in urban areas with predomi-nance of closed catchments (basins without outlet) is the implementation of detention and infiltration reservoirs (DIR). This type of solution has the main function of storing surface runoff and to promote soil infiltration and, consequently, aquifer recharge. The practice is to avoid floods in the drainage basin low-lying areas. The catchment waterproofing reduces the distributed groundwater recharge in urban areas, as is the case of Natal city, RN. However, the advantage of DIR is to concentrate the runoff and to promote aquifer recharge to an amount that can surpass the distributed natu-ral recharge. In this paper, we proposed studying a small urban drainage catchment, named Experimental Mirassol Watershed (EMW) in Natal, RN, whose outlet is a DIR. The rainfall-runoff transformation processes, water accumulation in DIR and the pro-cess of infiltration and percolation in the soil profile until the free aquifer were mod-eled and, from rainfall event observations, water levels in DIR and free aquifer water level measurements, and also, parameter values determination, it is was enabled to calibrate and modeling these combined processes. The mathematical modeling was carried out from two numerical models. We used the rainfall-runoff model developed by RIGHETTO (2014), and besides, we developed a one-dimensional model to simu-late the soil infiltration, percolation, redistribution soil water and groundwater in a combined system to the reservoir water balance. Continuous simulation was run over a period of eighteen months in time intervals of one minute. The drainage basin was discretized in blocks units as well as street reaches and the soil profile in vertical cells of 2 cm deep to a total depth of 30 m. The generated hydrographs were transformed into inlet volumes to the DIR and then, it was carried out water balance in these time intervals, considering infiltration and percolation of water in the soil profile. As a re-sult, we get to evaluate the storage water process in DIR as well as the infiltration of water, redistribution into the soil and the groundwater aquifer recharge, in continuous temporal simulation. We found that the DIR has good performance to storage excess water drainage and to contribute to the local aquifer recharge process (Aquifer Dunas / Barreiras).

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Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants (BFRs) that have been heavily used in consumer products such as furniture foams, plastics, and textiles since the mid-1970’s. BFRs are added to products in order to meet state flammability standards intended to increase indoor safety in the event of a fire. The three commercial PBDE mixtures, Penta-, Octa-, and DecaBDE, have all been banned in the United States, however, limited use of DecaBDE is still permitted. PBDEs were phased out of production and added to the Stockholm Convention due to concerns over their environmental persistence and toxicity. Human exposure to PBDEs occurs primarily through the inadvertent ingestion of contaminated house dust, as well as though dietary sources. Despite the phase-out and discontinued use of PBDEs, human exposure to this class of chemicals is likely to continue for decades due to the continued use of treated products and existing environmental reservoirs of PBDEs. Extensive research over the years has shown that PBDEs disrupt thyroid hormone (TH) levels and neurodevelopmental endpoints in rodent and fish models. Additionally, there is growing epidemiological evidence linking PBDE exposure in humans to altered TH homeostasis and neurodevelopmental impairments in children. Due to the importance of THs throughout gestation, there is a great need to understand the effects of BFRs on the developing fetus. Specifically, the placenta plays a critical role in the transport, metabolism, and delivery of THs to the fetal compartment during pregnancy and is a likely target for BFR bioaccumulation and endocrine disruption. The central hypothesis of this dissertation research is that BFRs disrupt the activity of TH sulfotransferase (SULT) enzymes, thereby altering TH concentrations in the placenta.

In the first aim of this dissertation research, the concentrations of PBDEs and 2,4,6-TBP were measured in a cohort of 102 placenta tissue samples from an ongoing pregnancy cohort in Durham, NC. Methods were developed for the extraction and analysis of the BFR analytes. It was found that 2,4,6-TBP was significantly correlated with all PBDE analytes, indicating that 2,4,6-TBP may share common product applications with PBDEs or that 2,4,6-TBP is a metabolite of PBDE compounds. Additionally, this was the first study to measure 2,4,6-TBP in human placenta tissues.

In the second aim of this dissertation research, the placenta tissue concentrations of THs, as well as the endogenous activity of deiodinase (DI) and TH SULT enzymes were quantified using the same cohort of 102 placenta tissue samples. Enzyme activity was detected in all samples and this was the first study to measure TH DI and SULT activity in human placenta tissues. Enzyme activities and TH concentrations were compared with BFR concentrations measured in Aim 1. There were few statistically significant associations observed for the combined data, however, upon stratifying the data set based on infant sex, additional significant associations were observed. For example, among males, those with the highest concentrations of BDE-99 in placenta had T3 levels 0.80 times those with the lowest concentration of BDE-99 (95% confidence interval (CI): 0.59, 1.07). Whereas females with the highest concentrations of BDE-99 in placenta had T3 levels 1.50 times those with the lowest concentration of BDE-99 (95% CI: 1.10, 2.04). Additionally, all BFR analyte concentrations were higher in the placenta of males versus females and they were significantly higher for 2,4,6-TBP and BDE-209. 3,3’-T2 SULT activity was significantly higher in female placenta tissues, while type 3 DI activity was significantly higher in male placenta tissues. This research is the first to show sex-specific differences in the bioaccumulation of BFRs in human placenta tissue, as well as differences in TH concentrations and endogenous DI and SULT activity. The underlying mechanisms of these observed sex differences warrant further investigation.

In the third aim of this dissertation research, the effects of BFRs were examined in a human choriocarcinoma placenta cell line, BeWo. Michaelis-Menten parameters and inhibition curves were calculated for 2,4,6-TBP, 3-OH BDE-47, and 6-OH BDE-47. 2,4,6-TBP was shown to be the most potent inhibitor of 3,3’-T2 SULT activity with a calculated IC50 value of 11.6 nM. It was also shown that 2,4,6-TBP and 3-OH BDE-47 exhibit mixed inhibition of 3,3’-T2 sulfation in BeWo cell homogenates. Next, a series of cell culture exposure experiments were performed using 1, 6, 12, and 24 hour exposure durations. Once again, 2,4,6-TBP was shown to be the most potent inhibitor of basal 3,3’-T2 SULT activity by significantly decreasing activity at the high and medium dose (1 M and 0.5 M, respectively) at all measured time points. Interestingly, BDE-99 was also shown to inhibit basal 3,3’-T2 SULT activity in BeWo cells following the 24 hour exposure, despite exhibiting no inhibitory effects in the BeWo cell homogenate experiments. This indicates that BDE-99 must act through a pathway other than direct enzyme inhibition. Following exposures, the TH concentrations in the cell culture growth media and mRNA expression of TH-related genes were also examined. There was no observed effect of BFR treatment on these endpoints. Future work should focus on determining the downstream biological effects of TH SULT disruption in placental cells, as well as the underlying mechanisms of action responsible for reductions in basal TH SULT activity following BFR exposure.

This was one of the first studies to measure BFRs in a cohort of placenta tissue samples from the United States and the first study to measure THs, DI activity, and SULT activity in human placenta tissues. This research provides a novel contribution to our growing understanding of the effects of BFRs on TH homeostasis within the human placenta, and provides further evidence for sex-specific differences within this important organ. Future research should continue to investigate the effects of environmental contaminants on TH homeostasis within the placenta, as this represents the most critical and vulnerable stage of human development.

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Ce mémoire porte sur le rôle des cercles abolitionnistes dans l’application des lois sur l’émancipation graduelle de l’esclavage dans le nord des États-Unis vers la fin du dix-huitième siècle, principalement à New York et en Pennsylvanie. Plus particulièrement, il met en lumière la façon dont ces cercles, dont les deux plus importants étaient la Pennsylvania Abolition So-ciety (PAS) et le New­York Manumission Society (NYMS), ont fait face aux centaines de réfugiés de Saint-Domingue qui sont arrivés avec leurs esclaves sur la côte est américaine pour fuir la révolution haïtienne dans les années 1790. Dans un premier temps, ce mémoire étudie l’abolition graduelle de l’esclavage dans le nord des États-Unis, débutant avec la Pennsylvanie en 1780, et la formation des cercles abolitionnistes dans les anciennes colonies anglaises. Il sera en outre question des stratégies des antiesclavagistes américains afin de promouvoir l’abolition graduelle de l’esclavage et d’empêcher le mouvement des esclaves et des noirs libres en dehors des frontières de leurs États respectifs. Il sera aussi question de leurs efforts pour resserrer davantage les clauses des lois existantes à ce sujet. Dans un second temps, dans le but de mettre en relief la contribution des cercles abolitionnistes, ce mémoire procède à une étude de cas sur la manière dont les réfugiés de Saint-Domingue ont interagi avec l’esclavage résiduel à New York et en Pennsylvanie et cherche à comprendre pourquoi leurs tentatives d’échapper aux lois sur l’émancipation graduelle se sont heurtées, à plusieurs reprises, aux stratégies des sociétés antiesclavagistes.

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Ce mémoire porte sur le rôle des cercles abolitionnistes dans l’application des lois sur l’émancipation graduelle de l’esclavage dans le nord des États-Unis vers la fin du dix-huitième siècle, principalement à New York et en Pennsylvanie. Plus particulièrement, il met en lumière la façon dont ces cercles, dont les deux plus importants étaient la Pennsylvania Abolition So-ciety (PAS) et le New­York Manumission Society (NYMS), ont fait face aux centaines de réfugiés de Saint-Domingue qui sont arrivés avec leurs esclaves sur la côte est américaine pour fuir la révolution haïtienne dans les années 1790. Dans un premier temps, ce mémoire étudie l’abolition graduelle de l’esclavage dans le nord des États-Unis, débutant avec la Pennsylvanie en 1780, et la formation des cercles abolitionnistes dans les anciennes colonies anglaises. Il sera en outre question des stratégies des antiesclavagistes américains afin de promouvoir l’abolition graduelle de l’esclavage et d’empêcher le mouvement des esclaves et des noirs libres en dehors des frontières de leurs États respectifs. Il sera aussi question de leurs efforts pour resserrer davantage les clauses des lois existantes à ce sujet. Dans un second temps, dans le but de mettre en relief la contribution des cercles abolitionnistes, ce mémoire procède à une étude de cas sur la manière dont les réfugiés de Saint-Domingue ont interagi avec l’esclavage résiduel à New York et en Pennsylvanie et cherche à comprendre pourquoi leurs tentatives d’échapper aux lois sur l’émancipation graduelle se sont heurtées, à plusieurs reprises, aux stratégies des sociétés antiesclavagistes.