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1.
Int J Neonatal Screen ; 7(3)2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34449549

RESUMO

Screening for severe combined immunodeficiency (SCID) was introduced into the Swedish newborn screening program in August 2019 and here we report the results of the first year. T cell receptor excision circles (TRECs), kappa-deleting element excision circles (KRECs), and actin beta (ACTB) levels were quantitated by multiplex qPCR from dried blood spots (DBS) of 115,786 newborns and children up to two years of age, as an approximation of the number of recently formed T and B cells and sample quality, respectively. Based on low TREC levels, 73 children were referred for clinical assessment which led to the diagnosis of T cell lymphopenia in 21 children. Of these, three were diagnosed with SCID. The screening performance for SCID as the outcome was sensitivity 100%, specificity 99.94%, positive predictive value (PPV) 4.11%, and negative predictive value (NPV) 100%. For the outcome T cell lymphopenia, PPV was 28.77%, and specificity was 99.95%. Based on the first year of screening, the incidence of SCID in the Swedish population was estimated to be 1:38,500 newborns.

2.
Addict Biol ; 25(3): e12761, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31099157

RESUMO

Excessive alcohol use causes considerable morbidity and mortality worldwide. Changes in the mesolimbic dopamine system have been postulated as a neurobiological underpinning of excessive alcohol consumption, and recent research also suggests that the amino acid taurine plays a central role in ethanol-induced dopamine elevation. The aim of this study was to further outline the role of dopamine and taurine in regulating alcohol consumption. In this study, a choice between ethanol (20%) and water was administered to Wistar rats in an intermittent manner (three times/week) for seven consecutive weeks. In vivo microdialysis was used to explore baseline levels as well as ethanol-induced increases of extracellular dopamine and taurine, in the nucleus accumbens (nAc) of Wistar rats voluntarily consuming large or small amounts of ethanol. Basal levels of taurine were also measured in cerebrospinal fluid (CSF) and serum in a subset of rats. Ethanol-induced increases in nAc dopamine and taurine did not differ between alcohol-consuming and naïve rats. However, when categorized based on ethanol intake, rats consuming larger amounts of ethanol exhibited a lower dopamine tone in the nucleus accumbens and responded to ethanol with a slower elevation of extracellular taurine levels, as compared with low-consuming animals. Basal levels of taurine in nAc, CSF, or serum did not differ between ethanol high- and low-consuming rats. Our data support previous studies claiming an association between low endogenous dopamine levels and excessive alcohol intake.


Assuntos
Consumo de Bebidas Alcoólicas/metabolismo , Depressores do Sistema Nervoso Central/administração & dosagem , Dopamina/metabolismo , Etanol/administração & dosagem , Núcleo Accumbens/metabolismo , Taurina/metabolismo , Animais , Comportamento Animal , Líquido Cefalorraquidiano/química , Microdiálise , Ratos , Ratos Wistar , Autoadministração
3.
J Neural Transm (Vienna) ; 124(5): 607-619, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28161754

RESUMO

The glycine transporter-1 inhibitor Org25935 is a promising candidate in a treatment concept for alcohol use disorder targeting the glycine system. Org25935 inhibits ethanol-induced dopamine elevation in brain reward regions and reduces ethanol intake in Wistar rats. This study aimed to further characterise the compound and used ethanol consumption, behavioral measures, and gene expression as parameters to investigate the effects in Wistar rats and, as pharmacogenetic comparison, Alko-Alcohol (AA) rats. Animals were provided limited access to ethanol in a two-bottle free-choice paradigm with daily drug administration. Acute effects of Org25935 were estimated using locomotor activity and neurobehavioral status. Effects on gene expression in Wistar rats were measured with qPCR. The higher but not the lower dose of Org25935 reduced alcohol intake in Wistar rats. Unexpectedly, Org25935 reduced both ethanol and water intake and induced strong CNS-depressive effects in AA-rats (withdrawn from further studies). Neurobehavioral effects by Org25935 differed between the strains (AA-rats towards sedation). Org25935 did not affect gene expression at the mRNA level in the glycine system of Wistar rats. The data indicate a small therapeutic range for the anti-alcohol properties of Org25935, a finding that may guide further evaluations of the clinical utility of GlyT-1 inhibitors. The results point to the importance of pharmacogenetic considerations when developing drugs for alcohol-related medical concerns. Despite the lack of successful clinical outcomes, to date, the heterogeneity of drug action of Org25935 and similar agents and the unmet medical need justify further studies of glycinergic compounds in alcohol use disorder.


Assuntos
Dissuasores de Álcool/farmacologia , Consumo de Bebidas Alcoólicas/tratamento farmacológico , Consumo de Bebidas Alcoólicas/metabolismo , Proteínas da Membrana Plasmática de Transporte de Glicina/antagonistas & inibidores , Neurotransmissores/farmacologia , Tetra-Hidronaftalenos/farmacologia , Dissuasores de Álcool/química , Consumo de Bebidas Alcoólicas/genética , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Depressores do Sistema Nervoso Central/administração & dosagem , Comportamento de Escolha/efeitos dos fármacos , Comportamento de Escolha/fisiologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Etanol/administração & dosagem , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/fisiologia , Predisposição Genética para Doença , Proteínas da Membrana Plasmática de Transporte de Glicina/metabolismo , Masculino , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Neurotransmissores/química , RNA Mensageiro/metabolismo , Ratos Wistar , Tetra-Hidronaftalenos/química
4.
Addict Biol ; 22(1): 93-102, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26365786

RESUMO

Drugs of abuse share the ability to increase extracellular dopamine (DA) levels in the mesolimbic DA system. This effect has been linked to positive and reinforcing experiences of drug consumption and is presumed to be of importance for continued use, as well as for the development of dependence and addiction. Previous rat studies from our lab have implicated a neuronal circuitry involving glycine receptors in nucleus accumbens (nAc) and, secondarily, nicotinic acetylcholine receptors in the ventral tegmental area (VTA) in ethanol's (EtOH) DA-elevating effect. The work presented here, performed in male Wistar rats, suggests that the lateral septum (LS), which has previously been associated with different aspects of EtOH-related behaviour, is involved as well. In vivo microdialysis methodology demonstrated that blocking the generation of action potentials in LS using tetrodotoxin prevented a DA increase in nAc after accumbal EtOH perfusion. Retrograde tracing and polymerase chain reaction (PCR) were used to identify and characterize cells projecting to VTA from nAc/LS and from LS to nAc. Based on the PCR results, cells projecting from both LS/nAc to anterior VTA and from LS to nAc were mainly GABAergic neurons expressing glycine receptors, and these cells are presumed to be involved in mediating the DA-elevating effect of EtOH. These results provide further evidence implicating LS in the reinforcing effects of EtOH. Additional studies are needed to investigate LS involvement in EtOH consumption behaviour and its potential role in the development of dependence and addiction.


Assuntos
Depressores do Sistema Nervoso Central/farmacologia , Dopamina/metabolismo , Etanol/farmacologia , Núcleos Septais/efeitos dos fármacos , Núcleos Septais/metabolismo , Animais , Masculino , Modelos Animais , Ratos , Ratos Wistar
5.
J Clin Immunol ; 37(1): 51-60, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27873105

RESUMO

Newborn screening for severe primary immunodeficiencies (PID), characterized by T and/or B cell lymphopenia, was carried out in a pilot program in the Stockholm County, Sweden, over a 2-year period, encompassing 58,834 children. T cell receptor excision circles (TREC) and kappa-deleting recombination excision circles (KREC) were measured simultaneously using a quantitative PCR-based method on DNA extracted from dried blood spots (DBS), with beta-actin serving as a quality control for DNA quantity. Diagnostic cutoff levels enabling identification of newborns with milder and reversible T and/or B cell lymphopenia were also evaluated. Sixty-four children were recalled for follow-up due to low TREC and/or KREC levels, and three patients with immunodeficiency (Artemis-SCID, ATM, and an as yet unclassified T cell lymphopenia/hypogammaglobulinemia) were identified. Of the positive samples, 24 were associated with prematurity. Thirteen children born to mothers treated with immunosuppressive agents during pregnancy (azathioprine (n = 9), mercaptopurine (n = 1), azathioprine and tacrolimus (n = 3)) showed low KREC levels at birth, which spontaneously normalized. Twenty-nine newborns had no apparent cause identified for their abnormal results, but normalized with time. Children with trisomy 21 (n = 43) showed a lower median number of both TREC (104 vs. 174 copies/µL blood) and KREC (45 vs. 100 copies/3.2 mm blood spot), but only one, born prematurely, fell below the cutoff level. Two children diagnosed with DiGeorge syndrome were found to have low TREC levels, but these were still above the cutoff level. This is the first large-scale screening study with a simultaneous detection of both TREC and KREC, allowing identification of newborns with both T and B cell defects.


Assuntos
Triagem Neonatal , Imunodeficiência Combinada Severa/diagnóstico , Feminino , Testes Genéticos/métodos , Idade Gestacional , Humanos , Recém-Nascido , Masculino , Reação em Cadeia da Polimerase Multiplex , Triagem Neonatal/métodos , Fenótipo , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Antígenos de Linfócitos T/genética , Recombinação Genética , Fatores de Risco , Deleção de Sequência , Imunodeficiência Combinada Severa/genética , Suécia
6.
Neuropharmacology ; 82: 69-75, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24686030

RESUMO

The ability of drugs of abuse to increase mesolimbic levels of dopamine is a characteristic associated with their rewarding effects. Exactly how these effects are produced by different substances is not as well characterised. Our previous work in rats has demonstrated that accumbal glycine receptors (GlyRs) are involved in mediating the dopamine-activating effects of ethanol, and in modulating ethanol intake. In this study the investigation of GlyR involvement was extended to include several different drugs of abuse. By using microdialysis and electrophysiology we compared effects of addictive drugs, with and without the GlyR antagonist strychnine, on dopamine levels and neurotransmission in nucleus accumbens. The dopamine-increasing effect of systemic ethanol and the drug-induced change in neurotransmission in vitro, as measured by microdialysis and field potential recordings, were dependent on GlyRs in nAc. Accumbal GlyRs were also involved in the actions of tetrahydrocannabinol and nicotine, but not in those of cocaine or morphine. These data indicate that accumbal GlyRs play a key role in ethanol-induced dopamine activation and contribute also to that of cannabinoids and nicotine.


Assuntos
Dopamina/metabolismo , Drogas Ilícitas/farmacologia , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/fisiopatologia , Receptores de Glicina/metabolismo , Animais , Depressores do Sistema Nervoso Central/farmacologia , Cocaína/farmacologia , Inibidores da Captação de Dopamina/farmacologia , Dronabinol/farmacologia , Etanol/farmacologia , Glicinérgicos/farmacologia , Alucinógenos/farmacologia , Masculino , Microdiálise , Microeletrodos , Morfina/farmacologia , Entorpecentes/farmacologia , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Ratos Wistar , Receptores de Glicina/antagonistas & inibidores , Estricnina/farmacologia , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia
7.
Alcohol Clin Exp Res ; 38(3): 722-9, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24224855

RESUMO

BACKGROUND: Over 100 million people worldwide are affected by alcohol use disorders. These conditions usually take years to develop where an initial, voluntary consumption is gradually replaced by a compulsive intake of alcohol. The exact mechanisms behind this transition remain unknown. However, ethanol (EtOH) is known to interact with several neurotransmitters and receptors in the central nervous system, and chronic EtOH consumption causes alterations in these neurotransmitter systems, proposed to contribute to the development of dependence. This study aimed to repeat previous findings that animals after long-term voluntary EtOH consumption spontaneously increase their intake. That the initial encounter with EtOH causes an elevation of dopamine in the nucleus accumbens (nAc), inducing feelings of well-being and creating an incentive to continue the behavior, has been repeatedly reported in both animals and humans. The effects of chronic EtOH consumption on this region are not as well investigated. METHODS: We examined both long-term EtOH consumption behavior and its consequences on expression of neurotransmitter-related genes in the nAc of the Wistar rat using quantitative polymerase chain reaction. RESULTS: In general, the EtOH consumption of the animals in this study was modest with an average intake of 0.9 g/kg/d, and only 1 of the 24 rats consuming EtOH for 10 months drastically increased its intake in line with the results of Wolffgramm and Heyne (1995). Expression of the genes for dopamine receptor 2, µ-opioid receptor, and somatostatin receptor 4 were down-regulated in animals after 2 and/or 4, but not 10, months of EtOH consumption. CONCLUSIONS: Chronic consumption even of modest amounts of alcohol seems to affect regulation of expression of these genes, possibly leading to changes in neurotransmitter signaling. Studies are ongoing to investigate whether these alterations are specific for the nAc.


Assuntos
Consumo de Bebidas Alcoólicas/metabolismo , Depressores do Sistema Nervoso Central/efeitos adversos , Etanol/efeitos adversos , Núcleo Accumbens/efeitos dos fármacos , Receptores de Neurotransmissores/metabolismo , Animais , Depressores do Sistema Nervoso Central/administração & dosagem , Etanol/administração & dosagem , Perfilação da Expressão Gênica , Masculino , Núcleo Accumbens/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Distribuição Aleatória , Ratos , Ratos Wistar
8.
Brain Res ; 1446: 12-21, 2012 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-22330726

RESUMO

Glycine receptors (GlyRs) are pentameric membrane proteins in the form of either α-homomers or α-ß heteromers. Four out of five subunits; α1-3 and ß, have been found in the mammalian brain. Early studies investigating subunit composition and expression patterns of this receptor have proposed a developmental switch from α2 homomers to α1ß heteromers as the CNS matures, a conclusion primarily based on results from the spinal cord. However, our previous results indicate that this might not apply to e.g. the forebrain regions. Here we examined alterations in GlyR expression caused by developmental changes in selected brain areas, focusing on reward-related regions. Animals of several ages (P2, P21 and P60) were included to examine potential changes over time. In accordance with previous reports, a switch in expression was observed in the spinal cord. However, the present results indicate that a decrease in α2 subunit expression is not replaced by α1 subunit expression since the generally low levels, and modest increases, of α1 could hardly replace the reduction in α2-mRNA. Instead mRNA measurements indicate that α2 continues to be the dominating α-subunit also in adult animals, usually in combination with high and stable levels of ß-subunit expression. This indicates that alterations in GlyR subunit expression are not simply a maturation effect common for the entire CNS, but rather a unique pattern of transition depending on the region at hand.


Assuntos
Envelhecimento , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Prosencéfalo/crescimento & desenvolvimento , Prosencéfalo/metabolismo , Subunidades Proteicas/metabolismo , Receptores de Glicina/metabolismo , Fatores Etários , Análise de Variância , Animais , Animais Recém-Nascidos , Feminino , Masculino , Subunidades Proteicas/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptores de Glicina/genética
9.
Neuropharmacology ; 61(7): 1160-5, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21251919

RESUMO

Recent research suggests that adaptations elicited by drugs of abuse share common features with traditional learning models, and that drugs of abuse cause long-term changes in behavior by altering synaptic function and plasticity. In this study, endocannabinoid (eCB) signaling in the dorsolateral striatum, a brain region vital for habit formation, was evaluated in acutely isolated brain slices from ethanol (EtOH)-consuming rats and control rats. EtOH-consuming rats had free access to a 20% EtOH solution for three 24 hour sessions a week during seven weeks and consumed an average of 3.4 g/kg per session. eCB-mediated long-lasting disinhibition (DLL) of population spike (PS) amplitude induced by moderate frequency stimulation was impaired in EtOH-consuming rats, and was not restored by the muscarinic receptor antagonist scopolamine (10 µM). The lack of DLL could be linked to a reduced GABA(A) receptor tone, since bicuculline-mediated disinhibition of striatal output was significantly reduced in slices from EtOH-consuming rats. However, eCB signaling induced by high frequency stimulation (HFS) was also impaired in slices from EtOH-consuming rats and isolated control rats. Activation of presynaptic cannabinoid 1 receptors (CB1R) with WIN55,212-2 (250 nM, 1 µM) significantly modulated PS amplitude in slices from age-matched control rats while slices from EtOH-consuming rats remained unaffected, indicating that eCB signaling is inhibited at a level that is downstream from CB1R activation. Intermittent alcohol intake for seven weeks might thus be sufficient to modulate a presynaptic mechanism that needs to be synergized with CB1R activation for induction of long-term depression (LTD). In conclusion, alcohol consumption inhibits striatal eCB signaling in a way that could be of importance for understanding the neurological underpinnings of addictive behavior.


Assuntos
Consumo de Bebidas Alcoólicas/metabolismo , Moduladores de Receptores de Canabinoides/metabolismo , Corpo Estriado/efeitos dos fármacos , Endocanabinoides , Inibição Neural/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Receptor CB1 de Canabinoide/metabolismo , Transdução de Sinais/efeitos dos fármacos , Consumo de Bebidas Alcoólicas/efeitos adversos , Animais , Benzoxazinas/farmacologia , Bicuculina/farmacologia , Corpo Estriado/metabolismo , Corpo Estriado/fisiopatologia , Antagonistas de Receptores de GABA-A/farmacologia , Técnicas In Vitro , Masculino , Morfolinas/farmacologia , Antagonistas Muscarínicos/farmacologia , Naftalenos/farmacologia , Proteínas do Tecido Nervoso/agonistas , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/metabolismo , Plasticidade Neuronal/efeitos dos fármacos , Neurônios/metabolismo , Ratos , Ratos Wistar , Receptor CB1 de Canabinoide/agonistas , Escopolamina/farmacologia , Potenciais Sinápticos/efeitos dos fármacos
10.
Brain Res ; 1305 Suppl: S27-36, 2009 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-19781529

RESUMO

Ethanol is known to directly interact with the glycine receptor (GlyR). GlyRs are membrane proteins and are constituted as either alpha-homomers or alpha-beta heteromers with a subunit stoichiometry of 2 alpha 3 beta. Previous studies by our group have suggested a role for GlyRs and its endogenous ligands glycine and taurine in the mesolimbic dopamine activating and reinforcing effects of ethanol. Here we use quantitative PCR (qPCR) to compare the relative GlyR expression in Alko Alcohol/Non-Alcohol (AA/ANA) rats. These animals have been selectively bred to create distinct populations regarding alcohol consumption and preference, presumably mainly due to genetic differences. The aim of this study was to examine the relative gene expression of GlyR subunits (alpha1-3 and beta) in different brain areas and relate it to alcohol consumption. The hypothesis was that AA/ANA rats are differently disposed to ethanol consumption due to their GlyR set-ups and/or compositions. Results from the present study indicate that alpha2 is the most widely expressed alpha-subunit in the forebrain regions and that the alpha 2 beta-heteromer seems to be the most common subunit composition in this part of the CNS. Despite displaying different drinking behaviours the anticipated differences in mRNA expression were few. However, correlations found between alcohol consumption and/or preference and GlyR expression support a role for GlyRs in alcohol consumption. Tentative differences between AA and ANA animals related to GlyR transmission could therefore lie in, for example, the regulation of the levels of the endogenous ligand(s) for the receptor or in mechanisms downstream to GlyR activation.


Assuntos
Consumo de Bebidas Alcoólicas/metabolismo , Prosencéfalo/metabolismo , Receptores de Glicina/metabolismo , Animais , Encéfalo/metabolismo , Depressores do Sistema Nervoso Central/administração & dosagem , Etanol/administração & dosagem , Masculino , RNA Mensageiro/metabolismo , Distribuição Aleatória , Ratos , Ratos Mutantes , Especificidade da Espécie
11.
Philos Trans R Soc Lond B Biol Sci ; 364(1526): 2027-45, 2009 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-19528054

RESUMO

Plastics debris in the marine environment, including resin pellets, fragments and microscopic plastic fragments, contain organic contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons, petroleum hydrocarbons, organochlorine pesticides (2,2'-bis(p-chlorophenyl)-1,1,1-trichloroethane, hexachlorinated hexanes), polybrominated diphenylethers, alkylphenols and bisphenol A, at concentrations from sub ng g(-1) to microg g(-1). Some of these compounds are added during plastics manufacture, while others adsorb from the surrounding seawater. Concentrations of hydrophobic contaminants adsorbed on plastics showed distinct spatial variations reflecting global pollution patterns. Model calculations and experimental observations consistently show that polyethylene accumulates more organic contaminants than other plastics such as polypropylene and polyvinyl chloride. Both a mathematical model using equilibrium partitioning and experimental data have demonstrated the transfer of contaminants from plastic to organisms. A feeding experiment indicated that PCBs could transfer from contaminated plastics to streaked shearwater chicks. Plasticizers, other plastics additives and constitutional monomers also present potential threats in terrestrial environments because they can leach from waste disposal sites into groundwater and/or surface waters. Leaching and degradation of plasticizers and polymers are complex phenomena dependent on environmental conditions in the landfill and the chemical properties of each additive. Bisphenol A concentrations in leachates from municipal waste disposal sites in tropical Asia ranged from sub microg l(-1) to mg l(-1) and were correlated with the level of economic development.


Assuntos
Aves/metabolismo , Poluentes Ambientais/análise , Cadeia Alimentar , Modelos Teóricos , Plásticos/química , Água do Mar/química , Resíduos/análise , Adsorção , Animais , Compostos Benzidrílicos , Aves/fisiologia , Disruptores Endócrinos/análise , Poluentes Ambientais/farmacocinética , Comportamento Alimentar/fisiologia , Éteres Difenil Halogenados/análise , Cinética , Praguicidas/análise , Petróleo/análise , Fenóis/análise , Poliquetos/metabolismo , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise
12.
J Vasc Res ; 46(4): 270-7, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19033689

RESUMO

BACKGROUND/AIMS: The analysis of blood flow responses to iontophoresis of vasoactive drugs is often limited to evaluation of maximum responses. In this study, a time-response model is proposed for the blood flow responses to vasoactive drugs applied by iontophoresis. METHODS: The microvascular bed is represented as a single compartment with a zero-order influx of the drugs from the electrode and a first-order clearance due to diffusion and blood flow. The blood flow response to the local drug dose is described using the E(max) model. RESULTS: The model accurately describes the blood flow responses to acetylcholine and sodium nitroprusside during a single iontophoretic current pulse. There is a significant clearance out of the microvascular bed during iontophoresis which depends on the type of drug administered. CONCLUSION: The model enables an accurate estimation of response parameters such as ED50 and maximum response, even if the true maximum blood flow is not obtained. The results suggest that due to clearance from the microvascular bed, the local drug dose during a single pulse of current is not linearly proportional to current strength multiplied by pulse duration.


Assuntos
Acetilcolina/administração & dosagem , Endotélio Vascular/efeitos dos fármacos , Iontoforese , Modelos Cardiovasculares , Nitroprussiato/administração & dosagem , Pele/irrigação sanguínea , Vasodilatação/efeitos dos fármacos , Vasodilatadores/administração & dosagem , Acetilcolina/farmacocinética , Administração Cutânea , Adulto , Velocidade do Fluxo Sanguíneo , Difusão , Relação Dose-Resposta a Droga , Endotélio Vascular/diagnóstico por imagem , Endotélio Vascular/metabolismo , Feminino , Humanos , Fluxometria por Laser-Doppler , Masculino , Microcirculação/efeitos dos fármacos , Nitroprussiato/farmacocinética , Fluxo Sanguíneo Regional/efeitos dos fármacos , Absorção Cutânea , Ultrassonografia , Vasodilatadores/farmacocinética , Adulto Jovem
13.
Biodegradation ; 17(5): 389-402, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16477363

RESUMO

A landfill typically progresses through a series of microbial degradation phases, in which hydrolysis, production and consumption of fermentation products, such as fatty acids, and methane formation play important roles. For ultimate degradation of the waste, stable methanogenic conditions have to be attained, and maintained for sufficient time. Using experimental data from 100-L landfill simulation reactors containing municipal solid waste from a residential area, a distributed model, which accounts for vertical water flow, was developed. As a first step, the waste was divided into two fractions: readily degradable and recalcitrant waste. Secondly, the general hydrolysis of the recalcitrant waste was accounted for by including a specific, well-defined chemical substance in the model that generally occurs in Municipal Solid Waste (MSW) and is hydrolysed before its further degradation to methane. For this purpose we chose diethyl phthalate and its hydrolysis product monoethyl phthalate, for which leachate data are available from the reactors. The model indicated that inhibition of the hydrolytic and methanogenic processes occurred during the acidogenic phase and that it could be overcome either by improving the chemical environment or by the complete oxidation of the inhibiting, i.e. the easily degraded, fraction of the waste. The generality of the model was confirmed by the patterns of the phthalate di- and monoester transformations obtained. The validity of the model was further confirmed using experimental data from parallel reactors, which were subjected to either leachate exchange with an already methanogenic reactor or to initial aeration to force the reactor into stable methanogenic conditions.


Assuntos
Metano/metabolismo , Modelos Biológicos , Eliminação de Resíduos/métodos , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Reatores Biológicos , Concentração de Íons de Hidrogênio , Hidrólise , Ácidos Ftálicos/metabolismo , Prótons
14.
Appl Microbiol Biotechnol ; 69(4): 474-84, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16096786

RESUMO

Phthalates such as dimethyl phthalate, dimethyl terephthalate (DMT), diethyl phthalate (DEP), di(2-ethylhexyl) phthalate and mono(2-ethylhexyl) phthalate (MEHP) are degraded to varying degrees under anaerobic conditions in waste treatment systems. Here we kinetically analyse the enzymatic hydrolyses involved and the subsequent stoichiometric reactions. The resulting model indicates that the degradation of the alcohols released and the transformation of the phthalic acid (PA) result in biphasic kinetics for the methane formation during transformation of DMT, DEP and MEHP. The ester hydrolysis and the PA transformation to methane appear to be the two rate-limiting steps. The PA-fermenting bacteria, which have biomass-specific growth rates between 0.04 and 0.085 day(-1), grow more slowly than the other bacteria involved. Anaerobic microorganisms that remove intermediate products during phthalic acid ester conversion appear to be important for the efficiency of the ultimate phthalate degradation and to be inhibited by elevated hydrogen partial pressures. The model was based on (and the simulations corresponded well with) data obtained from experimental waste treatment systems.


Assuntos
Bactérias Anaeróbias/metabolismo , Ésteres/metabolismo , Ácidos Ftálicos/metabolismo , Eliminação de Resíduos/métodos , Anaerobiose , Bactérias Anaeróbias/crescimento & desenvolvimento , Microbiologia Industrial/métodos , Cinética , Metano/metabolismo , Modelos Biológicos
15.
J Biol Chem ; 278(47): 47181-9, 2003 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-12972423

RESUMO

Polyamines (putrescine, spermidine, and spermine) are essential for growth and survival of all cells. When polyamine biosynthesis is inhibited, there is up-regulation of import. The mammalian polyamine transport system is unknown. We have previously shown that the heparan sulfate (HS) side chains of recycling glypican-1 (Gpc-1) can sequester spermine, that intracellular polyamine depletion increases the number of NO-sensitive N-unsubstituted glucosamines in HS, and that NO-dependent cleavage of HS at these sites is required for spermine uptake. The NO is derived from S-nitroso groups in the Gpc-1 protein. Using RNA interference technology as well as biochemical and microscopic techniques applied to both normal and uptake-deficient cells, we demonstrate that inhibition of Gpc-1 expression abrogates spermine uptake and intracellular delivery. In unperturbed cells, spermine and recycling Gpc-1 carrying HS chains rich in N-unsubstituted glucosamines were co-localized. By exposing cells to ascorbate, we induced release of NO from the S-nitroso groups, resulting in HS degradation and unloading of the sequestered polyamines as well as nuclear targeting of the deglycanated Gpc-1 protein. Polyamine uptake-deficient cells appear to have a defect in the NO release mechanism. We have managed to restore spermine uptake partially in these cells by providing spermine NONOate and ascorbate. The former bound to the HS chains of recycling Gpc-1 and S-nitrosylated the core protein. Ascorbate released NO, which degraded HS and liberated the bound spermine. Recycling HS proteoglycans of the glypican-type may be plasma membrane carriers for cargo taken up by caveolar endocytosis.


Assuntos
Proteoglicanas de Heparan Sulfato/metabolismo , Óxido Nítrico/metabolismo , Poliaminas/farmacocinética , Ácido Ascórbico/farmacologia , Proteínas de Transporte/química , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Proteoglicanas de Heparan Sulfato/química , Proteoglicanas de Heparan Sulfato/genética , Heparitina Sulfato/química , Humanos , Microscopia de Fluorescência , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo III , Compostos Nitrosos/metabolismo , Poliaminas/metabolismo , Espermina/farmacocinética , Transfecção
16.
Water Res ; 37(3): 609-17, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12688695

RESUMO

Leachates from 17 different landfills in Europe were analysed with respect to phthalates, i.e. phthalic acid diesters (PAEs) and their degradation products phthalic acid monoesters (PMEs) and ortho-phthalic acid (PA). Diesters are ubiquitous and the human possible exposure and potential to human health and environment has put them in focus. The aim of this study was to elucidate whether monoesters and phthalic acid could be traced in landfill leachates and in what concentrations they may be found. The results showed that phthalates were present in the majority of the leachates investigated. The monoesters appeared from 1 to 20 microg/L and phthalic acid 2-880 microg/L (one divergent value of 19 mg phthalic acid/L). Their parental diesters were observed from 1 to 460 microg/L. These observed occurrences of degradation products, of all diesters studied, support that they are degraded under the landfill conditions covered by this study. Thus, we have presented strong evidences to conclude that microorganisms in landfills degrade diesters released from formulations in a variety of products, including polyvinyl chloride (PVC) species.


Assuntos
Ácidos Ftálicos/química , Eliminação de Resíduos , Poluentes do Solo/análise , Poluentes da Água/análise , Biodegradação Ambiental , Monitoramento Ambiental , Europa (Continente) , Ácidos Ftálicos/análise , Ácidos Ftálicos/metabolismo , Microbiologia do Solo
17.
Environ Toxicol Chem ; 22(12): 3037-43, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14713047

RESUMO

The degradation of phthalic acid diesters may lead to formation of o-phthalic acid and phthalic acid monoesters. The ecotoxic properties of the monoesters have never been systematically investigated, and concern has been raised that these degradation products may be more toxic than the diesters. Therefore, the aquatic toxicity of phthalic acid, six monoesters, and five diesters of o-phthalic acid was tested in three standardized toxicity tests using the bacteria Vibrio fischeri, the green algae Pseudokirchneriella subcapitata, and the crustacean Daphnia magna. The monoesters tested were monomethyl, monoethyl, monobutyl, monobenzyl, mono(2-ethylhexyl), and monodecyl phthalate, while the diesters tested were dimethyl, diethyl, dibutyl, butylbentyl, and di(2-ethylhexyl)phthalate, which were assumed to be below their water solubility. The median effective concentration (EC50) values for the three organisms ranged from 103 mg/L to >4.710 mg/L for phthalic acid, and corresponding values for the monoesters ranged from 2.3 mg/L (monodecyl phthalate in bacteria test) to 4,130 mg/L (monomethyl phthalate in bacteria test). Dimethyl and diethyl phthalate were found to be the least toxic of the diesters (EC50 26.2-377 mg/L), and the toxicity of the other diesters (butylbenzyl and dibutyl phthalate) ranged from 0.96 to 7.74 mg/L. In general, the phthalate monoesters (degradation products) were less toxic than the corresponding diesters (mother compounds).


Assuntos
Ácidos Ftálicos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Clorófitas , Daphnia , Ésteres , Dose Letal Mediana , Vibrio
18.
Analyst ; 127(8): 1045-9, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12195944

RESUMO

A method was developed for the simultaneous determination of the following nine volatile sulfur compounds in gas samples: carbon disulfide, carbonyl sulfide, ethyl sulfide, ethyl methyl sulfide, hydrogen sulfide, isopropanethiol, methanethiol, methyl disulfide and methyl sulfide. The target compounds were preconcentrated by solid-phase microextraction (SPME) and determined by gas chromatography combined with mass spectrometry. Experimental design was employed to optimize the extraction time and temperature and concurrent detection of the nine compounds was achieved by using an SPME fiber coated with Carboxen-polydimethylsiloxane (75 microns). Detection limits ranged from 1 ppt (v/v) for carbon disulfide to 350 ppt (v/v) for hydrogen sulfide and calibration functions were linear up to 20 ppb (v/v) for all the compounds investigated.


Assuntos
Compostos de Enxofre/análise , Poluentes Químicos da Água/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos
19.
J Chromatogr A ; 963(1-2): 57-64, 2002 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-12188001

RESUMO

Procedures were assessed for quantifying nine volatile sulfur compounds found in complex gaseous samples collected at a biogas-production plant and a sewage treatment plant. The target compounds were extracted by solid-phase microextraction (using the 75-microm Carboxen-polydimethylsiloxane fiber coating) at 22 degrees C for 20 min, and analyzed by GC-MS. Detection limits ranged between 1 pptv (v/v) for carbon disulfide and 470 pptv (v/v) for hydrogen sulfide. High amounts of organic compounds were found during full-scan analysis of the samples and standard additions to individual sub-samples revealed that the analysis was subject to matrix effects. However, the functions obtained by standard additions were still linear and quantification was possible for all the compounds tested except hydrogen sulfide. No detectable losses were observed during storage in the sampling containers, made of Tedlar film, over a storage period of 20 h. However, water permeated through the walls and the relative humidity in the bag increased during storage until it reached the ambient level. Finally, it was shown that the drying agent, CaCl2, caused no detectable losses of any of the compounds.


Assuntos
Gases/química , Compostos de Enxofre/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Sensibilidade e Especificidade , Volatilização
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