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1.
Braz. j. med. biol. res ; 50(2): e5592, 2017. graf
Artigo em Inglês | LILACS | ID: biblio-839247

RESUMO

Levels of hydrogen sulfide (H2S), a gaseous signaling molecule, are reduced in the serum of individuals who smoke. We hypothesized that tobacco smoke influenced smooth muscle relaxation by decreasing H2S levels and this effect could also influence expression of cystathionine γ-lyase (CSE) and sulfonylurea receptor-2 (SUR-2). The aim of this study was to explore the effect of tobacco smoke on H2S-mediated rat thoracic aorta relaxation and its possible mechanism. Thirty-two Sprague-Dawley rats were divided into four groups: control (C) group, short-term smoker (SS) group, mid-term smoker (MS) group, and long-term smoker (LS) group. H2S concentrations in serum, action of H2S on rat aortic vascular relaxation, and expression of CSE and SUR-2 in thoracic aortic smooth muscle were measured. Although there was no significant difference in H2S between the C and the SS groups, concentration of H2S was significantly reduced in both the LS and MS groups compared to control (P<0.01). Furthermore, H2S was significantly lower in the LS than in the MS group (P<0.05). Rat aortic vascular relaxation was lower in all three treatment groups compared to the control, with the most significant decrease observed in the LS group (P<0.05 compared to the MS group). Expression of CSE and SUR-2 was reduced in the LS and MS groups compared to control (P<0.05), with the lowest levels observed in the LS group (P<0.05). Therefore, tobacco smoke reduced expression of CSE and SUR-2 in rat thoracic aorta, which may inhibit H2S production and vascular dilation.


Assuntos
Animais , Masculino , Ratos , Aorta Torácica/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Sulfeto de Hidrogênio , Poluição por Fumaça de Tabaco , Modelos Animais , Ratos Sprague-Dawley , Fatores de Tempo
2.
Braz. j. microbiol ; 47(1): 181-190, Jan.-Mar. 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-775120

RESUMO

Abstract In the present work we isolated and identified various indigenous Saccharomyces cerevisiae strains and screened them for the selected oenological properties. These S. cerevisiae strains were isolated from berries and spontaneously fermented musts. The grape berries (Sauvignon blanc and Pinot noir) were grown under the integrated and organic mode of farming in the South Moravia (Czech Republic) wine region. Modern genotyping techniques such as PCR-fingerprinting and interdelta PCR typing were employed to differentiate among indigenous S. cerevisiae strains. This combination of the methods provides a rapid and relatively simple approach for identification of yeast of S. cerevisiae at strain level. In total, 120 isolates were identified and grouped by molecular approaches and 45 of the representative strains were tested for selected important oenological properties including ethanol, sulfur dioxide and osmotic stress tolerance, intensity of flocculation and desirable enzymatic activities. Their ability to produce and utilize acetic/malic acid was examined as well; in addition, H2S production as an undesirable property was screened. The oenological characteristics of indigenous isolates were compared to a commercially available S. cerevisiae BS6 strain, which is commonly used as the starter culture. Finally, some indigenous strains coming from organically treated grape berries were chosen for their promising oenological properties and these strains will be used as the starter culture, because application of a selected indigenous S. cerevisiae strain can enhance the regional character of the wines.


Assuntos
Saccharomyces cerevisiae/classificação , Saccharomyces cerevisiae/isolamento & purificação , Vitis/microbiologia , Ácido Acético/metabolismo , Aderência Bacteriana , República Tcheca , Impressões Digitais de DNA , Tolerância a Medicamentos , Etanol/toxicidade , Sulfeto de Hidrogênio/metabolismo , Tipagem Molecular , Técnicas de Tipagem Micológica , Malatos/metabolismo , Pressão Osmótica , Reação em Cadeia da Polimerase , Estresse Fisiológico , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologia , Dióxido de Enxofre/toxicidade
3.
Int. braz. j. urol ; 41(6): 1185-1193, Nov.-Dec. 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-769773

RESUMO

Introduction/Objective: Ureteral obstruction is a common pathology and causes kidney fibrosis and dysfunction at late period. In this present study, we investigated the antifibrotic and antiinflammatory effects of hydrogen sulfide on kidney damage after unilateral ureteral obstruction (UUO) in rats. Materials and Methods: 24 rats were divided into four groups. Group 1 was control, group 2 was sham, group 3 included rats with UUO and group 4 rats with UUO which were given sodium hydrogen sulfide (NaHS)-exogenous donor of hydrogen sulfide (intraperitoneally 56μmoL/kg/day). After 14 days, rats were killed and their kidneys were taken and blood analysis was performed. Tubular necrosis, mononuclear cell infiltration and interstitial fibrosis were determined histopathologically in a part of the kidneys; nitric oxide (NO), malondialdehyde (MDA) and reduced glutathione (GSH) levels were determined in the other part of the kidneys. Urea-creatinine levels were investigated by blood analysis. Statistical analyses were made by the Chi-square test and one-way analysis of variance (ANOVA). Results: There was no significantly difference for urea-creatinine levels among groups. Pathologically, there was serious tubular necrosis and fibrosis in group 3 and there was significantly decreasing of tubular necrosis and fibrosis in group 4 (p<0.005). Also, there was significantly increase of NO and MDA levels and decrease of GSH levels in group 3 compared to other groups (p<0.005). Conclusions: hydrogen sulfide prevents kidney damage with antioxidant and antiinflammatory effect.


Assuntos
Animais , Masculino , Anti-Inflamatórios/farmacologia , Sulfeto de Hidrogênio/farmacologia , Insuficiência Renal/prevenção & controle , Obstrução Ureteral/prevenção & controle , Anti-Inflamatórios/uso terapêutico , Creatinina/sangue , Modelos Animais de Doenças , Fibrose , Glutationa/análise , Sulfeto de Hidrogênio/uso terapêutico , Rim/patologia , Malondialdeído/análise , Óxido Nítrico/análise , Estresse Oxidativo , Distribuição Aleatória , Ratos Wistar , Reprodutibilidade dos Testes , Insuficiência Renal/etiologia , Insuficiência Renal/patologia , Fatores de Tempo , Ureia/sangue , Obstrução Ureteral/complicações
4.
Int. braz. j. urol ; 41(3): 503-510, May-June 2015. ilus
Artigo em Inglês | LILACS | ID: lil-755866

RESUMO

ABSTRACTPurpose:

Calcium oxalate urolithiasis is one of the most common urinary tract diseases and is of high prevalence. The present study proposes to evaluate the antilithiatic property of hydrogen sulfide and its metabolites like thiosulfate & sulfate in an in vitro model.

Materials and Methods:

The antilithiatic activity of sodium hydrogen sulfide (NaSH), sodium thiosulfate (Na2S2O3) and sodium sulfate (Na2SO4) on the kinetics of calcium oxalate crystal formation was investigated both in physiological buffer and in urine from normal and recurrent stone forming volunteers. The stones were characterized by optical and spectroscopic techniques.

Results:

The stones were characterized to be monoclinic, prismatic and bipyramidal habit which is of calcium monohydrate and dihydrate nature. The FTIR displayed fingerprint corresponding to calcium oxalate in the control while in NaSH treated, S=O vibrations were visible in the spectrum. The order of percentage inhibition was NaSH>Na2S2O3>Na2SO4.

Conclusion:

Our study indicates that sodium hydrogen sulfide and its metabolite thiosulfate are inhibitors of calcium oxalate stone agglomeration which makes them unstable both in physiological buffer and in urine. This effect is attributed to pH changes and complexing of calcium by S2O32-and SO42- moiety produced by the test compounds.

.


Assuntos
Adulto , Feminino , Humanos , Masculino , Oxalato de Cálcio/metabolismo , Sulfeto de Hidrogênio/química , Sulfeto de Hidrogênio/metabolismo , Urolitíase/metabolismo , Urolitíase/prevenção & controle , Análise de Variância , Estudos de Casos e Controles , Oxalato de Cálcio/química , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Urina/química
5.
Rev. Esc. Enferm. USP ; 49(1): 69-75, Jan-Feb/2015. graf
Artigo em Inglês | LILACS | ID: lil-742066

RESUMO

OBJECTIVE To evaluate the effect of using antihypertensive classes of drugs of the calcium channel antagonists and inhibitors of angiotensin-converting enzyme in plasma concentrations of hydrogen sulfide and nitric oxide in patients with hypertension. METHODS Cross-sectional study with quantitative approach conducted with hypertensive patients in use of antihypertensive classes of drugs: angiotensin-converting enzyme inhibitors or calcium channel antagonists. RESULTS It was found that the concentration of plasma nitric oxide was significantly higher in hypertensive patients that were in use of angiotensin-converting enzyme inhibitors (p<0.03) and the hydrogen sulphide concentration was significantly higher in hypertensive plasma in use of calcium channel antagonists (p<0.002). CONCLUSION The findings suggest that these medications have as additional action mechanism the improvement of endothelial dysfunction by elevate plasma levels of vasodilatory substances. .


OBJETIVO Evaluar el efecto del uso de antihipertensivos pertenecientes a las clases medicamentosas antagonistas de canales de calcio e inhibidores de la enzima convertidora de angiotensina en las concentraciones plasmáticas de ácido sulfhídrico y óxido nítrico en portadores de hipertensión arterial sistémica. MÉTODO Estudio transversal con abordaje cuantitativo realizado con hipertensos que toman antihipertensivos de las clases de inhibidores de la enzima convertidora de angiotensina o antagonistas de los canales de calcio. RESULTADOS Se verificó que la concentración de óxido nítrico plasmático fue significativamente mayor en hipertensos que estaban usando inhibidores de la enzima convertidora de angiotensina (p<0.03) y que la concentración de ácido sulfhídrico plasmático fue significativamente mayor en hipertensos en uso de antagonistas de los canales de calcio (p<0.002). CONCLUSIÓN Los hallazgos sugieren que dichos fármacos tienen como mecanismo de acción adicional la mejora de la disfunción endotelial al elevar los niveles plasmáticos de sustancias vasodilatadoras. .


OBJETIVO Avaliar o efeito do uso de anti-hipertensivos pertencentes às classes medicamentosas antagonistas de canais de cálcio e inibidores da enzima conversora de angiotensina nas concentrações plasmáticas de ácido sulfídrico e óxido nítrico em portadores de hipertensão arterial sistêmica. MÉTODO Estudo transversal com abordagem quantitativa realizado com hipertensos em uso de anti-hipertensivos das classes inibidores da enzima conversora de angiotensina ou antagonistas dos canais de cálcio. RESULTADOS Verificou-se que a concentração de óxido nítrico plasmático foi significativamente maior em hipertensos que estavam em uso de inibidores da enzima conversora de angiotensina (p<0.03) e que a concentração de ácido sulfídrico plasmático foi significativamente maior em hipertensos em uso de antagonistas dos canais de cálcio (p<0.002). CONCLUSÃO Os achados sugerem que essas medicações possuem como mecanismo de ação adicional a melhora da disfunção endotelial por elevar os níveis plasmáticos de substâncias vasodilatadoras. .


Assuntos
Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Sulfeto de Hidrogênio/sangue , Hipertensão/sangue , Hipertensão/tratamento farmacológico , Óxido Nítrico/sangue , Estudos Transversais
6.
Braz. j. med. biol. res ; 46(8): 708-714, ago. 2013. tab, graf
Artigo em Inglês | LILACS | ID: lil-684527

RESUMO

Our objective was to investigate the protective effect of Lawesson's reagent, an H2S donor, against alendronate (ALD)-induced gastric damage in rats. Rats were pretreated with saline or Lawesson's reagent (3, 9, or 27 µmol/kg, po) once daily for 4 days. After 30 min, gastric damage was induced by ALD (30 mg/kg) administration by gavage. On the last day of treatment, the animals were killed 4 h after ALD administration. Gastric lesions were measured using a computer planimetry program, and gastric corpus pieces were assayed for malondialdehyde (MDA), glutathione (GSH), proinflammatory cytokines [tumor necrosis factor (TNF)-α and interleukin (IL)-1β], and myeloperoxidase (MPO). Other groups were pretreated with glibenclamide (5 mg/kg, ip) or with glibenclamide (5 mg/kg, ip)+diazoxide (3 mg/kg, ip). After 1 h, 27 µmol/kg Lawesson's reagent was administered. After 30 min, 30 mg/kg ALD was administered. ALD caused gastric damage (63.35±9.8 mm2); increased levels of TNF-α, IL-1β, and MDA (2311±302.3 pg/mL, 901.9±106.2 pg/mL, 121.1±4.3 nmol/g, respectively); increased MPO activity (26.1±3.8 U/mg); and reduced GSH levels (180.3±21.9 µg/g). ALD also increased cystathionine-γ-lyase immunoreactivity in the gastric mucosa. Pretreatment with Lawesson's reagent (27 µmol/kg) attenuated ALD-mediated gastric damage (15.77±5.3 mm2); reduced TNF-α, IL-1β, and MDA formation (1502±150.2 pg/mL, 632.3±43.4 pg/mL, 78.4±7.6 nmol/g, respectively); lowered MPO activity (11.7±2.8 U/mg); and increased the level of GSH in the gastric tissue (397.9±40.2 µg/g). Glibenclamide alone reversed the gastric protective effect of Lawesson's reagent. However, glibenclamide plus diazoxide did not alter the effects of Lawesson's reagent. Our results suggest that Lawesson's reagent plays a protective role against ALD-induced gastric damage through mechanisms that depend at least in part on activation of ATP-sensitive potassium (KATP) channels.


Assuntos
Animais , Feminino , Ratos , Alendronato/antagonistas & inibidores , Mucosa Gástrica/efeitos dos fármacos , Sulfeto de Hidrogênio/farmacologia , Indicadores e Reagentes/farmacologia , Compostos Organotiofosforados/farmacologia , Gastropatias/induzido quimicamente , Análise de Variância , Cistationina gama-Liase/análise , Diagnóstico por Computador , Diazóxido/administração & dosagem , Mucosa Gástrica/patologia , Glutationa/análise , Glibureto/administração & dosagem , Interleucina-1beta/análise , Canais KATP/farmacologia , Malondialdeído/análise , Peroxidase/análise , Peroxidase/metabolismo , Ratos Wistar , Gastropatias/enzimologia , Gastropatias/patologia , Fator de Necrose Tumoral alfa/análise
7.
Artigo em Espanhol | LILACS | ID: lil-673082

RESUMO

Antecedentes: El efecto de los Compuestos Volátiles Sulfurados (CVS) sobre los tejidos periodontales, específicamente a nivel del eje RANKL/OPG, no ha sido dilucidado y en la actualidad existe escasa literatura al respecto publicada. Objetivo: Evaluar si los CVS medidos en la cavidad oral de pacientes con periodontitis crónica moderada a severa se relacionan con la expresión de RANKL y OPG a nivel de fluido gingival crevicular (FGC). Método: Se realizó un estudio transversal con 71 pacientes derivados de la Unidad de Diagnóstico de la Clínica Odontológica Docente Asistencial de la Universidad de los Andes. Posterior a la realización de un examen periodontal completo se tomaron muestra de los niveles de CVS de la boca de los pacientes mediante un monitor de sulfuros y muestras de FGC para evaluar los niveles de RANKL y OPG mediante test de ELISA. Los datos obtenidos fueron analizados mediante test de correlación de Spearman. Resultados: Al evaluar la correlación de los niveles de CVS con los niveles de RANKL, OPG y la razón RANKL/OPG, se observó un R de 0.098 con un p value = 0.41; -0.084 con un p value= 0.48 y 0.067 con un p value = 0.57 respectivamente. Conclusiones: El presente estudio no pudo demostrar si existe una relación entre los niveles de CVS con la expresión de RANKL y OPG en el FGC de pacientes con periodontitis crónica.


Background: The effect of the Volatile Sulfur Compounds (VSC) on the periodontal tissues, specifically at the RANKL/OPG level has not been elucidate and there is little literature published on this subject. Aim: To explore if the VSC levels measured in the oral cavity of patients with moderate or severe chronic periodontitis are correlated with the expression of RANKL and OPG at the gingival fluid level (GF). Method: A cross-sectional study was conducted with 71 patients referred by the Universidad de los Andes’s dentistry diagnosis department. After undergoing full-mouth periodontal exam, levels of CVS were recorded using a sulfur monitor and then GF was extracted to assess RANKL and OPG levels with ELISA. Data was analyzed with Spearman correlation test. Results: The correlation (R) between the VSC and the GF levels was 0.098 with a p value = 0.41; -0.084 with a p value = 0.48 y 0.067 with a p value = 0.57 respectively. Conclusions: This study could not demonstrate if there is a relation between the VSC levels and the expression of RANKL and OPG in the GF in patients with chronic periodontitis.


Assuntos
Humanos , Masculino , Adulto , Feminino , Pessoa de Meia-Idade , Compostos de Enxofre/análise , Periodontite Crônica/metabolismo , Sulfeto de Hidrogênio/análise , Testes Respiratórios , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Líquido do Sulco Gengival , Halitose/etiologia , Osteoprotegerina , Periodontite Crônica/complicações , Ligante RANK
8.
Arq. gastroenterol ; 50(2): 157-160, abr. 2013. tab, graf
Artigo em Inglês | LILACS | ID: lil-679152

RESUMO

Context Hydrogen sulphide (H2S) has been proved to be a neuromodulator and contributes to the maintenance of gastric mucosal integrity in damage caused by anti-inflammatory nonsteroidal drugs. Previously, we demonstrated that H2S synthesis is essential to gastric protection against ethanol. Objective To better understanding the role of H2S and the detailed localization of its production in both normal and injured stomach due to ethanol injection, we studied the expression of cystathionine-γ-lyase (CSE) and cystathionine-β-synthetase (CBS) isoforms in gastric mucosa of mice treated with saline or 50% ethanol. Methods Mice were treated by gavage with saline or 50% ethanol (0.5 mL/25 g). After 1 hour, mice were sacrificed, and gastric tissue was evaluated by histological and immunohistochemical analysis specific for CSE and CBS. Results We have demonstrated a non-specific expression of CBS in the normal gastric mucosa and expression of CSE occurring mainly in the parietal cells of the animals treated with ethanol. Conclusion Thus, we demonstrated that the expression of CBS appears to be constitutive and diffuse across the gastric epithelium, while the expression of CSE appears to be induced in parietal cells by damage agents such as ethanol. .


Contexto O sulfeto de hidrogênio (H2S) tem sido mostrado como um neuromodulador e contribuidor para a manutenção da integridade da mucosa gástrica na lesão causada por drogas antiinflamatórias não esteroidais. Previamente, demonstramos que a síntese de H2S é essencial para a proteção da mucosa gástrica contra a administração de etanol. Objetivo Para compreender o papel do H2S e a localização detalhada de sua produção no estômago normal e após lesão induzida pela administração de etanol, estudou-se a expressão das isoformas cistationina-γ-liase (CSE) e cistationina-β-sintetase (CBS) na mucosa gástrica de camundongos tratados com salina ou etanol 50%. Métodos Os camundongos foram tratados por gavagem com salina ou etanol 50% (0,5 mL/25 g). Após 1 hora, os camundongos foram sacrificados e os tecidos gástricos foram avaliados por análise histológica e imunoistoquímica específica para CBS e CSE. Resultados Foi demonstrado expressão não específica de CBS na mucosa gástrica normal e expressão de CSE ocorrendo principalmente nas células parietais dos animais tratados com etanol. Conclusão Assim, demonstramos que a expressão de CBS parece ser constitutiva e difusa através do epitélio gástrico, enquanto a expressão de CSE parece ser induzida nas células parietais por agentes lesivos como o etanol. .


Assuntos
Animais , Camundongos , Cistationina beta-Sintase/metabolismo , Cistationina gama-Liase/metabolismo , Mucosa Gástrica/enzimologia , Sulfeto de Hidrogênio/metabolismo , Modelos Animais de Doenças , Etanol/farmacologia , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/patologia , Imuno-Histoquímica
9.
In. Rodríguez Almada, Hugo; Abilleira, Doris; Bazán, Natalia; Bengochea, Milka; Borges, Freddy; Cano, Jacqueline; Coitinho, Cecilia; Gamero, Sylvia; Imbert, María; Lozano, Fernanda; Maglia Canzani, Daniel; Mederos Catalano, Domingo; Mesa Figueras, Guillermo; Rabotti, Claudio; Rodríguez Estula, Geraldine; Rodríguez Machado, María Noel; Roó, Rafael; Sarkissian May, Paula; Tidball-Binz, Morris; Verdú Pascual, Fernando. Patología forense. Montevideo, Oficina del Libro Fefmur, 2013. p.467-519.
Monografia em Espanhol | LILACS | ID: lil-763539
10.
Braz. j. med. biol. res ; 45(10): 898-905, Oct. 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-647748

RESUMO

The JAK2/STAT3 signal pathway is an important component of survivor activating factor enhancement (SAFE) pathway. The objective of the present study was to determine whether the JAK2/STAT3 signaling pathway participates in hydrogen sulfide (H2S) postconditioning, protecting isolated rat hearts from ischemic-reperfusion injury. Male Sprague-Dawley rats (230-270 g) were divided into 6 groups (N = 14 per group): time-matched perfusion (Sham) group, ischemia/reperfusion (I/R) group, NaHS postconditioning group, NaHS with AG-490 group, AG-490 (5 µM) group, and dimethyl sulfoxide (DMSO; <0.2%) group. Langendorff-perfused rat hearts, with the exception of the Sham group, were subjected to 30 min of ischemia followed by 90 min of reperfusion after 20 min of equilibrium. Heart rate, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), and the maximum rate of increase or decrease of left ventricular pressure (± dp/dt max) were recorded. Infarct size was determined using triphenyltetrazolium chloride (TTC) staining. Myocardial TUNEL staining was used as the in situ cell death detection method and the percentage of TUNEL-positive nuclei to all nuclei counted was used as the apoptotic index. The expression of STAT3, bcl-2 and bax was determined by Western blotting. After reperfusion, compared to the I/R group, H2S significantly improved functional recovery and decreased infarct size (23.3 ± 3.8 vs 41.2 ± 4.7%, P < 0.05) and apoptotic index (22.1 ± 3.6 vs 43.0 ± 4.8%, P < 0.05). However, H2S-mediated protection was abolished by AG-490, the JAK2 inhibitor. In conclusion, H2S postconditioning effectively protects isolated I/R rat hearts via activation of the JAK2/STAT3 signaling pathway.


Assuntos
Animais , Masculino , Ratos , Sulfeto de Hidrogênio/metabolismo , Pós-Condicionamento Isquêmico , /metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , /metabolismo , Apoptose , /análise , Ratos Sprague-Dawley , Transdução de Sinais , /análise , Tirfostinas
11.
Electron. j. biotechnol ; 15(3): 7-7, May 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-640551

RESUMO

Background: The behaviour of two biotrickling filters connected in serie (BTF) inoculated with Acidithiobacillus thiooxidans and Thiobacillus thioparus, biodegrading hydrogen sulphide (H2S) and dimethyl sulphide (DMS) simultaneously were studied. A model which considers gas to liquid mass transfer and biooxidation in the biofilm attached to the support is developed. Additionally, a fixed bed biotrickling filter where the microorganism is immobilized in a biofilm which degrades a mixture of H2S and DMS is implemented. Validation of the model was carried out using experimental data obtained at different H2S and DMS loads. Results: The inhibitory effect caused by the presence of H2S on the DMS is observed, which is evidenced by the decrease of the DMS removal efficiency from 80 to 27 percent, due to the preference that T. thioparus has by simple metabolism. H2S is not affected by the DMS, with removal efficiencies of 95 to 97 percent, but it decreases at high concentrations of the compound, due to the inhibition of metabolism by high H2S input loads. The model which describes the BFT fits successfully with the experimental results and it has a high sensitivity to inhibition parameters. Conclusion: It is shown that the microorganism has a high affinity for H2S, producing substrate inhibition when the concentration is high. The H2S is able to inhibit the DMS biooxidation, whereas the DMS does not affect the H2S biooxidation.


Assuntos
Filtração , Sulfeto de Hidrogênio , Modelos Teóricos , Sulfetos , Thiobacillus , Acidithiobacillus thiooxidans
12.
Braz. j. med. biol. res ; 45(3): 244-249, Mar. 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-618052

RESUMO

Animal models of gentamicin nephrotoxicity present acute tubular necrosis associated with inflammation, which can contribute to intensify the renal damage. Hydrogen sulfide (H2S) is a signaling molecule involved in inflammation. We evaluated the effect of DL-propargylglycine (PAG), an inhibitor of endogenous H2S formation, on the renal damage induced by gentamicin. Male Wistar rats (N = 8) were injected with 40 mg/kg gentamicin (im) twice a day for 9 days, some of them also received PAG (N = 8, 10 mg·kg-1·day-1, ip). Control rats (N = 6) were treated with saline or PAG only (N = 4). Twenty-four-hour urine samples were collected one day after the end of these treatments, blood samples were collected, the animals were sacrificed, and the kidneys were removed for quantification of H2S formation and histological and immunohistochemical studies. Gentamicin-treated rats presented higher sodium and potassium fractional excretion, increased plasma creatinine [4.06 (3.00; 5.87) mg percent] and urea levels, a greater number of macrophages/monocytes, and a higher score for tubular interstitial lesions [3.50 (3.00; 4.00)] in the renal cortex. These changes were associated with increased H2S formation in the kidneys from gentamicin-treated rats (230.60 ± 38.62 µg·mg protein-1·h-1) compared to control (21.12 ± 1.63) and PAG (11.44 ± 3.08). Treatment with PAG reduced this increase (171.60 ± 18.34), the disturbances in plasma creatinine levels [2.20 (1.92; 4.60) mg percent], macrophage infiltration, and score for tubular interstitial lesions [2.00 (2.00; 3.00)]. However, PAG did not interfere with the increase in fractional sodium excretion provoked by gentamicin. The protective effect of PAG on gentamicin nephrotoxicity was related, at least in part, to decreased H2S formation.


Assuntos
Animais , Masculino , Ratos , Alquinos/farmacologia , Antibacterianos/toxicidade , Gentamicinas/toxicidade , Glicina/análogos & derivados , Sulfeto de Hidrogênio/antagonistas & inibidores , Necrose Tubular Aguda/induzido quimicamente , Creatinina/sangue , Glicina/farmacologia , Sulfeto de Hidrogênio/metabolismo , Imuno-Histoquímica , Necrose Tubular Aguda/tratamento farmacológico , Rim/metabolismo , Ratos Wistar , Fatores de Tempo
13.
Fortaleza; s.n; 2009.
Tese em Português | LILACS | ID: lil-759754

RESUMO

Recentemente, foi demonstrado que o H2S está envolvido em inúmeras funções fisiológicas e patológicas, sendo produzido em muitos tecidos de mamíferos. OBJETIVOS: Avaliar o papel do H2S na defesa da mucosa e no controle da motilidade gástrica em camundongos, bem como estudar a participação dos canais de KATP, dos neurônios sensoriais sensíveis à capsaicina e dos receptores TRPV1 neste efeito. MÉTODOS: Camundongos Swiss foram pré-tratados com L-cisteína (25, 50 ou 100 mg/kg, v.o), NaHS (75, 150 ou 300 µmol/kg, v.o) ou Lawesson´s (3, 9, 27 ou 81 µmol/kg, v.o). Trinta minutos depois, o etanol 50% (0,5ml/25g, v.o) foi administrado. Depois de 1 h, os animais foram sacrificados e os estômagos abertos para determinação da área da lesão usando planimetria computadorizada. Além disso, fragmentos de tecidos foram removidos para análise microscópica e dosagem de glutationa e malondialdeído. Para o estudo do esvaziamento gástrico, outro grupo experimental foi tratado, por gavagem, com as mesmas doses de L-cisteína, NaHS ou Lawesson´s, decorridos 30 min os animais receberam uma solução glicosada (5%) contendo vermelho de fenol (0,75 mg/ml) em cada animal. Após 10, 20 ou 30 min os animais foram sacrificados e o esvaziamento gástrico foi avaliado por técnica de espectrofotometria. Em outro grupo experimental os animais foram pré-tratados com glibenclamida (3 e 10 mg/Kg, v.o.) ou capsazepina (10 mg/kg, i.p). Após 1h, foram administrados a L-cisteína (50 mg/kg) ou os doadores de H2S (NaHS 150 µmol/kg ou o reagente de Lawesson´s 27µmol/kg, v.o). Trinta minutos depois, o etanol 50% foi administrado para avaliação da lesão gástrica e solução de vermelho de fenol foi administrada para avaliar o esvaziamento gástrico conforme descrito anteriormente...


Assuntos
Animais , Camundongos , Etanol , Sulfeto de Hidrogênio , Gastropatias
14.
Biofarbo ; 15(15): 5-12, dic. 2007. tab, graf
Artigo em Espanhol | LILACS | ID: lil-507156

RESUMO

Los drenajes ácidos de mina (DAM) están caracterizados por acidez extrema y altas concentraciones de metales pesados y sulfatos. Las bacterias sulfato reductoras (BSR) reducen sulfatos oxidandola materia orgánica para la producción de sulfuro de hidrógeno y bicarbonato. la biorremediación consiste en la precipitación insoluble del sulfuro con los metales pesados y la alcalinización del medio por el bicarbonato.


Assuntos
Ácidos/análise , Metais Pesados/análise , Sulfeto de Hidrogênio/análise
15.
Electron. j. biotechnol ; 10(4): 514-520, oct. 2007. ilus, graf
Artigo em Inglês | LILACS | ID: lil-504123

RESUMO

Emissions of hydrogen sulfide (H2S) by industrial activities is frequent cause of corrosion and unpleasant odours. Treatment of gaseous emissions contaminated with H2S by biotrickling filters inoculated with single cultures of sulfur oxidizer bacteria exhibit several advantages over physicochemical methods, such as shorter adaptation times and higher removal ability. Biofilms of Thiobacillus thioparus and Acidithiobacillus thiooxidans have proved to exhibit high removal capacities, yet no comparative studies between them have been reported. This article reports the efficiency of biotrickling filters inoculated with T. thioparus and A. thiooxidans under similar conditions excepting the pH, that was the optimal for the bacterial growth, for the removal of H2S. The support was selected by determining the respirometric coefficients of the biomass. The maximum removal capacity of the biofilter inoculated with T. thioparus, operating within the range of pH (5.5-7.0) was 14 gS m-3 h-1, lower the value obtained for the biotrickling filter inoculated with A. thiooxidans; 370 gS m-3 h-1. Therefore, it is concluded that acid biotrickling filter inoculated with A. thiooxidans constitute the best strategy to remove H2S, with the advantage that the system not require an exhaustive pH control of the liquid media.


Assuntos
Acidithiobacillus thiooxidans/metabolismo , Biofilmes , Sulfeto de Hidrogênio/química , Thiobacillus/metabolismo , Biodegradação Ambiental , Biomassa , Poluição Ambiental/prevenção & controle , Filtração , Concentração de Íons de Hidrogênio , Resíduos Industriais , Oxirredução
16.
Biofarbo ; 13(13): 33-38, dic. 2005. ilus
Artigo em Espanhol | LILACS | ID: lil-507188

RESUMO

Las Bacterias Sulfato Reductoras (BSR) son responsables de la producción de sulfuro de hidrógeno (H2S) en anaerobiosis a partir de sulfatos y un donador de electrones. El sulfuro producido podría utilizarse para precipitar metales catiónicos divalentes,permitiendo la biorremediación de efluentes contaminados. El presente estudio forma parte del proyecto: “Biodiversidad Microbiana del programa UMSA-SAREC” con cooperación del departamento deBiotecnología de la Universidad de Lund y establece la posibilidad de montar biorreactores en el altiplano Boliviano para generar H2S. En el trabajo, se”utilizó paja de trigo (donador de electrones) y consorcio bacteriano A10 (BSR) obtenido de la laguna ChalviriPotosí. Bajo condiciones de cultivo batch, se obtuvo una concentración de H2S entre 5 y 8 mM, y en condiciones de cultivo continuo una concentración de25 mM a los 100 días, concentraciones similares se sostuvieron por 90 días, lo que hace este modelo prometedor para su aprovechamiento a escala industrial.


Assuntos
Sulfeto de Hidrogênio/análise
18.
Rev. cuba. hig. epidemiol ; 31(2): 72-7, jul.-dic. 1993. tab, ilus
Artigo em Espanhol | LILACS | ID: lil-149963

RESUMO

Se describe la elaboración, calibración y validación de laboratorio de un dosímetro pasivo de tira reactiva para la determinación de la concentración de sulfuro de hidrógeno en el aire. El dosímetro es válido para determinar concentraciones del orden de 10 a 100 mg/m3 (0,5 a 5 CMA) y tiempos de exposición de 15 min a 1,5 h. El error total de la determinación es de más o menos 15,2 por ciento . El método es sencillo y no requiere de análisis posterior en un laboratorio


Assuntos
Exposição Ambiental , Monitoramento Ambiental , Laboratórios , Fitas Reagentes , Sulfeto de Hidrogênio/análise
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