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1.
Water Sci Technol ; 81(10): 2043-2056, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32701485

RESUMO

This study was carried out to evaluate the effect of natural ventilation and intermittent pumping events in hydrogen sulfide and methane dynamics, in terms of system operation and risk of gas exposure. Work was conducted in a full scale gravity sewer downstream of pumping stations, in Portugal. Different ventilation rates and locations were assessed, as well as H2S removal rates and potential exposure risk, through the opening of distinct manhole covers. Increased ventilation, resulting from opening of one manhole cover, saw a 38% increase in average pipe air velocity peaks, doubling the estimated rate of air turnovers per day, accompanied by an increase of nearly 20% in H2S average removal rate. Simultaneous opening of two manhole covers induced similar airflow rates through the vent stack, but different rates throughout the pipe. H2S removal rates were also found to differ, according to location of open manholes, but also initial H2S headspace concentration. Under more unfavourable conditions, natural ventilation did not suffice in attaining recommended safety concentrations, regardless of number and location of open manhole covers. H2S concentrations above defined thresholds were verified for all studied setups. Headspace oxygen concentrations below an 18.5% asphyxiation threshold also occasionally occurred, even at manholes immediately downstream of ventilation point.


Assuntos
Sulfeto de Hidrogênio , Esgotos , Metano , Portugal , Ventilação
2.
Sci Total Environ ; 729: 138702, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32498155

RESUMO

Biogas is a renewable energy fuel that can be treated to increase purity so that the resulting "biomethane" can be injected into the natural gas pipeline grid. The trace contaminants in biogas and biomethane make up a small fraction of the total gas but they still have the potential to cause adverse health effects and pipeline corrosion. This study investigates the statistical distributions of 17 trace metals, six mercaptans, hydrogen sulfide, ammonia, and six additional trace organic compounds. Twelve of these 31 trace contaminants have been previously identified as constituents of concern based on their toxicity profiles and through health risk assessment studies. Untreated and treated samples of biogas were collected from 12 different biogas production facilities using diverse feedstocks throughout California. Results show that most biogas trace contaminants follow a single log-normal distribution or a bi-modal lognormal distribution depending on the type of production facility. Treatment of biogas demonstrates some removal for all trace contaminants, but four constituents of concern (copper, lead, hydrogen sulfide, and methyl mercaptan) are predicted to have a >1% probability of exceeding trigger levels even after common treatments. This finding suggests that enhanced monitoring may be warranted for these contaminants. Several trace metals and volatile organic compounds (VOCs) were found to have seasonal trends with greater concentrations in the summer and lower concentrations in the winter suggesting that seasonal variation should be considered in future monitoring plans.


Assuntos
Biocombustíveis , Sulfeto de Hidrogênio , Gás Natural , Compostos Orgânicos Voláteis
3.
Ying Yong Sheng Tai Xue Bao ; 31(3): 959-968, 2020 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-32537993

RESUMO

We investigated the signal relationship between phospholipase Dα1 (PLDα1) and the gas signal molecule hydrogen sulfide (H2S) in Arabidopsis thaliana response to the allelopathy of diterpenoid oridonin. The wild type Arabidopsis Columbia (WT), phospholipase Dα1 (PLDα1) deletion mutant pldα1, D-/L-cysteine desulfyrase synthetic deletion mutant d-cdes and l-cdes seedlings were used as experiment materials, while 60 µmol·L-1 oridonin was applied as treatment concentration. The results showed that oridonin significantly increased H2S content, PLD and D-/L-CDes activities, and gene expressions of PLDα1 and D-/L-CDes in WT. Under oridonin treatment, the D-CDes and L-CDes activities of pldɑ1 seedlings were significantly lower than those of WT. Both D-CDes and L-CDes activities increased after exogenous addition of phosphatidic acid (PA) and were higher than those of WT. Oridonin significantly inhibited root growth of four lines, with d-cdes and l-cdes being more sensitive to oridonin. Application of NaHS promoted root growth and endogenous H2S production of four lines under oridonin treatment, while application of PA increased root growth and endogenous H2S production in WT, pldɑ1 and l-cdes, but had no effect in d-cdes. These results indicated that PLDα1 and H2S played a vital role in driving the response of Arabidopsis to oridonin, and that PLDα1/PA was located at the upstream of D-CDes to participate the regulation of the H2S production and root growth.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Sulfeto de Hidrogênio , Alelopatia , Diterpenos de Caurano , Fosfolipases
4.
Am J Physiol Cell Physiol ; 319(2): C244-C249, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32515982

RESUMO

The outbreak of COVID-19 pneumonia caused by a new coronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) is posing a global health emergency and has led to more than 380,000 deaths worldwide. The cell entry of SARS-CoV-2 depends on two host proteins angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2). There is currently no vaccine available and also no effective drug for the treatment of COVID-19. Hydrogen sulfide (H2S) as a novel gasotransmitter has been shown to protect against lung damage via its anti-inflammation, antioxidative stress, antiviral, prosurvival, and antiaging effects. In light of the research advances on H2S signaling in biology and medicine, this review proposed H2S as a potential defense against COVID-19. It is suggested that H2S may block SARS-CoV-2 entry into host cells by interfering with ACE2 and TMPRSS2, inhibit SARS-CoV-2 replication by attenuating virus assembly/release, and protect SARS-CoV-2-induced lung damage by suppressing immune response and inflammation development. Preclinical studies and clinical trials with slow-releasing H2S donor(s) or the activators of endogenous H2S-generating enzymes should be considered as a preventative treatment or therapy for COVID-19.


Assuntos
Antivirais/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Sulfeto de Hidrogênio/uso terapêutico , Pneumonia Viral/tratamento farmacológico , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Animais , Betacoronavirus/patogenicidade , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Interações Hospedeiro-Patógeno , Humanos , Sulfeto de Hidrogênio/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/virologia , Pandemias , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , Serina Endopeptidases/metabolismo , Transdução de Sinais
5.
Ying Yong Sheng Tai Xue Bao ; 31(4): 1121-1129, 2020 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-32530186

RESUMO

To investigate the effects of H2S on mitochondrial functions under low temperature stress, we analyzed the effects of 0.05 mmol·L-1 NaHS and 15 µmmol·L-1 HT (hypotaurine and H2S scavenger) on mitochondria antioxidant enzyme activities and mitochondrial permeability transition pore, mitochondrial membrane fluidity, mitochondrial membrane potential, Cyt c/a ratio and H+-ATPase activity in sweet cherry stigma and ovary with sweet cherry variety Zaodaguo under -2 ℃ low temperature stress. The results showed that low temperature stress increased the concentrations of mitochondrial H2O2 and MDA, enhanced the mitochondrial membrane permeability, but decreased the mitochondrial membrane fluidity, membrane potential, Cyt c/a and H+-ATPase acti-vity. Application of NaHS at 0.05 mmol·L-1 could effectively reduce the concentrations of H2O2 and MDA, and keep higher activities of SOD, POD and CAT of mitochondrial for longer time. Furthermore, application of 0.05 mmol·L-1 NaHS could decrease mitochondrial membrane permeability while increase mitochondrial membrane fluidity, membrane potential, Cyt c/a and H+-ATPase activity in stigma and ovary under low temperature stress. The effects of NaHS were completely offset by HT addition. The results suggested that exogenous H2S could alleviate the oxidative damage on stigma and ovary stress through decreasing H2O2 accumulation, regulating mitochondria antioxidant system, increasing H+-ATPase activity, and mitigating mitochondria function under low temperature.


Assuntos
Sulfeto de Hidrogênio , Prunus avium , Feminino , Peróxido de Hidrogênio , Mitocôndrias , Ovário , Estresse Oxidativo , Temperatura
6.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 32(4): 443-448, 2020 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-32527350

RESUMO

OBJECTIVE: To study the new mechanism of Xuebijing injection improving the function of pulmonary vascular barrier from the perspective of claudin-5 protein. METHODS: Acute lung injury (ALI) model was induced by hydrogen sulfide (H2S) exposure. (1) In vivo study: Sprague-Dawley (SD) rats were divided into control group, H2S exposure group (exposure to 300×10-6 H2S for 3 hours), Xuebijing control group (Xuebijing injection 4 mL/kg , twice a day, for 3 days), and Xuebijing intervention group (H2S exposure after pretreatment of Xuebijing injection) according to random number method, with 6 rats in each group. At different time points (0, 6, 12 and 24 hours) after the model was made successfully, the total protein content in plasma and bronchoalveolar lavage fluid (BALF) of rats were detected respectively, and the pulmonary permeability index (PPI) was calculated (PPI = protein content in BALF/protein content in plasma), lung dry/wet weight ratio (W/D) was detected, and claudin-5 mRNA expression in lung tissue was measured by real time-polymerase chain reaction. (2) In vitro test: human pulmonary microvascular endothelial cells (HPMECs) were divided into blank control group, NaHS treatment group (co-incubated with 500 µmol/L NaHS for 12 hours), Xuebijing control group (2 g/L Xuebijing injection for 24 hours), and Xuebijing intervention group (2 g/L Xuebijing injection pre-treated for 24 hours, then co-incubated with 500 µmol/L NaHS for 12 hours). The HPMECs claudin-5 protein expression and monolayer permeability changes were measured at different co-incubation time (1, 3, 6, 12 and 24 hours) by Western Blot and fluoresceinsodium. RESULTS: (1) In vivo study: compared with the control group, the lung W/D ratio increased significantly at 6 hours and peaked at 12 hours after H2S exposure in rats (4.67±0.11 vs. 4.26±0.06, P < 0.01). The expression of claudin-5 mRNA in lung tissue was significantly decreased, which was 89% of control group 6 hours after exposure (P < 0.01). The total protein content in BALF and PPI at 12 hours after exposure were significantly higher than those in the control group [total protein content (mg/L): 262.31±14.24 vs. 33.30±3.09, PPI: (11.72±0.57)×10-3 vs. (1.21±0.08)×10-3, both P < 0.01], while the results in Xuebijing intervention group were significantly decreased [total protein content (mg/L): 153.25±7.32 vs. 262.31±14.24, PPI: (5.79±0.23)×10-3 vs. (11.72±0.57)×10-3, both P < 0.01]. (2) In vitro test: compared with the blank control group, after incubating HPMECs with NaHS, the permeability of monolayer endothelial cells gradually increased, reaching the highest level in 12 hours, about twice of that in the blank control group, while claudin-5 protein expression decreased to the lowest level at 12 hours (claudin-5/ß-actin: 0.42±0.03 vs. 1.03±0.05, P < 0.01). After intervention with Xuebijing, the permeability of endothelial cells was significantly improved (fluorescence intensity of fluorescein sodium: 1.46±0.10 vs. 1.89±0.11, P < 0.01), and the decrease of claudin-5 protein was reduced (claudin-5/ß-actin: 0.68±0.04 vs. 0.38±0.03, P < 0.01). CONCLUSIONS: Xuebijing injection may improve pulmonary vascular barrier function in ALI by upregulating claudin-5 expression.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Animais , Claudina-5 , Células Endoteliais , Humanos , Sulfeto de Hidrogênio , Pulmão , Ratos , Ratos Sprague-Dawley
7.
Chemosphere ; 255: 126931, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32402879

RESUMO

A lab-scale biotrickling filter (BTF) packed with porcelain Rasching ring and ceramsite was applied for co-treating of low concentrations of hydrogen sulfide (H2S) and ammonia (NH3), as major pollutants typically found in e.g., intensive livestock production facilities. In this study, the outlet gas concentrations of H2S and NH3 were used for indicators if the treated gas reached odor-free condition. Overall, excellent removal efficiencies were obtained for both H2S and NH3 in the BTF during Stage I (H2S alone) and Stage II (H2S and NH3). Specifically, the H2S outlet concentration was below the detection limit (∼3.6 ppbv) and the NH3 outlet concentration was less than 0.4 ppmv when the inlet concentrations of H2S and NH3 were around 1.8 ppmv and 35.3 ppmv, respectively. In this case, the running empty bed residence time was 10.2 s. During Stage II, the outlet H2S concentration was decreased significantly when the inlet NH3 concentration was increased, likely due to the influence by pH. Meanwhile, the outlet nitrous oxide (N2O) concentration was kept low (<2% NH3) during the experiment, suggesting a proper operation of the BTF. After the inlet gas shifted from H2S alone at Stage I to H2S and NH3 at Stage II, the main sulfur-oxidizing bacteria (SOB) species in the BTF switched from Acidithiobacillus to Thiobacillus.


Assuntos
Amônia/química , Reatores Biológicos , Sulfeto de Hidrogênio/química , Bactérias , Filtração
8.
Chemosphere ; 256: 127078, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32473468

RESUMO

This study investigated the feasibility of co-treating H2S and CO2 in a biological trickling filter (BTF) inoculated with hydrogenotrophic methanogens (HMs) and nitrate-reducing, sulfur-oxidizing bacteria. This was accomplished by introducing a pure culture of Thiobacillus denitrificans in a BTF that was successfully upgrading a biogas mimic (60:40 CH4:CO2) to >97% methane using an enriched HM consortium. Nitrate was fed as the electron acceptor to oxidize H2S. The results revealed that a severe competition for hydrogen's electrons occurred between carbon dioxide and nitrate. Due to this competition, N:S loading rates of 16:1 were required to achieve >98% H2S removal, a ratio which is four times greater than the theoretical N:S ratio for complete sulfur oxidation. However, such high nitrate loading rates (>50 g N-NO3- m-3 h-1) had a negative impact on the BTF's biogas upgrading performance. An electron balance illustrated the increasing diversion of H2 electrons towards nitrate reduction as nitrate loading increased. Overall, this study showed that simultaneous biogas upgrading and H2S removal in a single bioreactor is possible, but that achieving high yields for both reactions requires further research in process and culture optimization.


Assuntos
Biocombustíveis , Dióxido de Carbono/análise , Sulfeto de Hidrogênio/análise , Bactérias , Reatores Biológicos/microbiologia , Hidrogênio , Metano , Nitratos
9.
Life Sci ; 255: 117834, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32454158

RESUMO

AIMS: Hydrogen sulfide (H2S) is shown in ocular tissues and suggested to involve in the regulation of retinal circulation. However, the mechanism of H2S-induced relaxation on retinal artery is not clarified yet. Herein, we aimed to evaluate the role of several calcium (Ca2+) signaling and Ca2+ sensitization mechanisms in the relaxing effect of H2S donor, NaHS, on retinal arteries. MATERIALS AND METHODS: Relaxing effects of NaHS (10-5-3 × 10-3M) were determined on precontracted retinal arteries in Ca2+ free medium as well as in the presence of the inhibitors of Ca2+ signaling and Ca2+ sensitization mechanisms. Additively, Ca2+ sensitivity of the contractile apparatus were evaluated by CaCl2-induced contractions in the presence of NaHS (3 × 10-3M). Functional experiments were furtherly assessed by protein and/or mRNA expressions, as appropriate. KEY FINDINGS: The relaxations to NaHS were preserved in Ca2+ free medium while NaHS pretreatment decreased the responsiveness to CaCl2. The inhibitors of plasmalemmal Ca2+-ATPase, sarcoplasmic-endoplasmic reticulum Ca2+-ATPase, Na+-Ca2+ ion-exchanger and myosin light chain kinase (MLCK) unchanged the relaxations to NaHS. Likewise, Ca2+ sensitization mechanisms including, rho kinase, protein kinase C and tyrosine kinase were unlikely to mediate the relaxation to NaHS in retinal artery. Whereas, a marked reduction was determined in NaHS-induced relaxations in the presence of MLCP inhibitor, calyculin A. Supportively, NaHS pretreatment significantly reduced phosphorylation of MYPT1-subunit of MLCP. SIGNIFICANCE: The relaxing effect of NaHS in retinal artery is likely to be related to the activation of MLCP and partly, to decrement in Ca2+ sensitivity of contractile apparatus.


Assuntos
Cálcio/metabolismo , Sulfeto de Hidrogênio/metabolismo , Fosfatase de Miosina-de-Cadeia-Leve/metabolismo , Artéria Retiniana/metabolismo , Animais , Cloreto de Cálcio/administração & dosagem , Sinalização do Cálcio/fisiologia , Bovinos , Membrana Celular/metabolismo , Retículo Endoplasmático/metabolismo , Feminino , Masculino , Fosforilação/fisiologia , Sulfetos/administração & dosagem , Sulfetos/farmacologia
10.
Sheng Wu Gong Cheng Xue Bao ; 36(4): 792-800, 2020 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-32347073

RESUMO

Stomatal density is important for crop yield. In this paper, we studied the epidermal pattern factors (EPFs) related to stomatal development. Prokaryotic expression vectors were constructed to obtain EPFs. Then the relationship between EPFs and hydrogen sulfide (H2S) was established. First, AtEPF1, AtEPF2 and AtEPFL9 were cloned and constructed to pET28a vectors. Then recombinant plasmids pET28a-AtEPF1, pET28a-AtEPF2 and pET28a-AtEPFL9 were digested and sequenced, showing successful construction. Finally, they were transformed into E. coli BL21(DE3) separately and induced to express by isopropyl ß-D-galactoside (IPTG). The optimized expression conditions including IPTG concentration (0.5, 0.3 and 0.05 mmol/L), temperature (28 °C, 28 °C and 16 °C) and induction time (16 h, 16 h and 20 h) were obtained. The bands of purified proteins were about 18 kDa, 19 kDa and 14.5 kDa, respectively. In order to identify their function, the purified AtEPF2 and AtEPFL9 were presented to Arabidopsis thaliana seedlings. Interestingly, the H2S production rate decreased or increased compared with the control, showing significant differences. That is, EPFs affected the production of endogenous H2S in plants. These results provide a foundation for further study of the relationship between H2S and EPFs on stomatal development, but also a possible way to increase the yield or enhance the stress resistance.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Escherichia coli , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/isolamento & purificação , Proteínas de Arabidopsis/metabolismo , Escherichia coli/genética , Vetores Genéticos/genética , Sulfeto de Hidrogênio/metabolismo , Plasmídeos/genética , Plântula/metabolismo
11.
Water Res ; 176: 115727, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32259684

RESUMO

Dewatering and sulfide control are the key challenges in treating chemically enhanced primary treatment (CEPT) sludge. In this study, an electrochemical pretreatment (EPT) approach with the input of 10 V/800 mA was explored for simultaneously improving the dewaterability of CEPT sludge and eliminating its sulfide production. The effects of different electrode materials (carbon and titanium) and EPT durations (from 5 to 15 min) were documented to reveal the underlying EPT mechanism. EPT with titanium electrodes (titanium-EPT) led to limited improvement in dewaterability and sulfide control. EPT with carbon electrodes (carbon-EPT) for 15 min, however, led to decreases in capillary suction time and specific resistance in filtration of over 80% and the suppression of about 99% of hydrogen sulfide (H2S(g)) production over 5 days of anaerobic storage. Analysis of the characteristics of treated CEPT sludge revealed that carbon-EPT disintegrated sludge flocs with ∼70% reduction in sludge particle sizes and release of aromatic and tyrosine protein-like substances, thus enhancing sludge dewaterability. The sulfur balance in the liquid and gaseous phases showed that most of the sulfur-containing compounds remained in the solid phase as aliphatic sulfur and sulfonic acid after carbon-EPT, thereby mitigating sulfide emission. While the pattern of sulfur distribution in sludge with titanium-EPT was dominated by sulfide, it was similar to the control sample. Reduction in bacteria associated with sulfide production (i.e., Lachnospiraceae) in CEPT sludge after carbon-EPT also contributed to sulfide elimination. This study demonstrates that EPT can be a superior option for simultaneously enhancing the dewaterability of CEPT sludge and mitigating its sulfide production.


Assuntos
Sulfeto de Hidrogênio , Esgotos , Filtração , Sulfetos , Enxofre , Água
12.
Life Sci ; 252: 117661, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32305523

RESUMO

AIMS: Hydrogen sulfide (H2S) as a novel gasotransmitter can be endogenously produced in liver by cystathionine gamma-lyase (CSE). The dysfunctions of CSE/H2S system have been linked to various liver diseases. Acetyl-CoA is the key intermediate from the metabolism of lipid. This study examined the roles of H2S in hepatic acetyl-CoA and lipid metabolism. MATERIALS AND METHODS: Both in vitro cell model and in vivo animal model of lipid accumulation were used in this study. Western blotting and real-time PCR were used for analysis of protein and mRNA expression. Acetyl-CoA was analyzed by a coupled enzyme assay, and lipid accumulation was observed with Oil Red O staining. KEY FINDINGS: Incubation of human liver carcinoma (HepG2) cells with a mixture of free fatty acids (FFAs) or high glucose reduced CSE expression and H2S production, promoted intracellular accumulation of acetyl-CoA and lipid. Supply of exogenous NaHS or cysteine reduced acetyl-CoA contents and lipid accumulation, while blockage of CSE activity promoted intracellular lipid accumulation. Furthermore, H2S blocked FFAs-induced transcriptions of de novo lipogenesis, inflammation, and fibrosis-related genes. In vivo, knockout of CSE gene stimulated more hepatic acetyl-CoA and lipid accumulation in mice induced by high-fat choline-deficient diet. The expressions of lipogenesis, inflammation, and fibrosis-related genes were significantly higher in liver tissues from CSE knockout mice when compared with wild-type mice. SIGNIFICANCE: CSE/H2S system is indispensable for maintaining the homeostasis of acetyl-CoA and lipid accumulation and protecting from the development of inflammation and fibrosis in liver under excessive caloric ingestion.


Assuntos
Acetilcoenzima A/metabolismo , Cistationina gama-Liase/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Sulfeto de Hidrogênio/metabolismo , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Animais , Cistationina gama-Liase/genética , Modelos Animais de Doenças , Células Hep G2 , Humanos , Metabolismo dos Lipídeos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
13.
Zhonghua Yi Xue Za Zhi ; 100(14): 1095-1101, 2020 Apr 14.
Artigo em Chinês | MEDLINE | ID: mdl-32294875

RESUMO

Objective: To investigate the role of nitric oxide (NO) in hydrogen sulfide (H(2)S)-induced inhibition upon colonic smooth muscle contraction. Methods: Immunohistochemistry was applied to observe the distribution of H(2)S-producing enzymes CBS and CSE in adult male Wistar rats. Organ bath system was used to observe the spontaneous contraction of colonic smooth muscle. Patch clamp technique was applied to record currents of L-type calcium channel (I(Ca,L)) in smooth muscle cells. Results: Specific immunoreactivity for CSE and CBS was observed in mucosa, smooth muscle and enteric plexus of rat proximal colon. NaHS elicited relaxation in a concentration-dependent manner upon muscle contraction in the presence of tetrodotoxin. The NaHS IC(50) of LM was 917.6 µmol/L (95% CI: 776.3-1 085 µmol/L, n=6) and the NaHS IC(50) of CM was 730.4 µmol/L (95% CI: 592.2-900.8 µmol/L, n=6). The SNP-induced relaxation in muscle strips was partially reversed by NaHS (P<0.05). Instead, the relaxation caused by NaHS was decreased by the sGC inhibitor ODQ but affected neither by NO precursor L-arginine, the NO inhibitor L-NNA nor the competitive cGMP antagonist PET-cGMP. NaHS (100 µmol/L) increased I(Ca,L) while NaHS (300 µmol/L) decreased the peak I(Ca,L) with modifying the ion channel characteristics (P<0.05). Conclusions: Exogenous hydrogen sulfide might have a dual effect on colonic motility and its inhibitory effect might be independent of NO signaling system. L-type calcium channel may play an important role during the process of H(2)S modulating colonic contraction.


Assuntos
Contração Muscular , Animais , Colo , Sulfeto de Hidrogênio , Masculino , Óxido Nítrico , Ratos , Ratos Wistar
14.
Medicine (Baltimore) ; 99(14): e19684, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32243406

RESUMO

BACKGROUND: Fracture is a common disease; many factors affect fracture healing. Recent studies have confirmed that hydrogen sulfide (H2S) plays an essential role in bone formation, but most of these studies are drawing conclusions based on animal experiment; whether H2S could promote fracture healing in patients is still unclear. We aim to investigate the change of serum H2S in fracture patients, and analyze its effort on fracture healing. METHODS: This is a single-center, prospective cohort study. Patients with spinal or limb fracture will be recruited. Patient's serum and urine will be collected at baseline for examination (serum H2S, ß-CTX, OC, PINP, 25-OH-VitD3, S-CTX, urinary calcium, and urinary creatinine). All patients will be followed-up for 24 months in outpatients settings, the image of X-ray or CT will be reviewed and fracture healing will be judged by 2 experienced orthopedic physicians. The difference in serum parameters especially H2S will be compared between patients with fracture healed within 9 months and those with fracture unhealed at 9 months. DISCUSSION: Results of the trial could provide insight into influence of H2S on fracture healing. ETHICS AND DISSEMINATION: The study was approved by the ethics committee of School of Medicine UESTC & Sichuan Provincial People's Hospital Ethics Committee. All the participants will be asked to provide written informed consent before data collection. The findings of the study will be published in peer-reviewed journals and will be presented at national or international conferences.


Assuntos
Consolidação da Fratura/fisiologia , Fraturas Ósseas/sangue , Sulfeto de Hidrogênio/sangue , Traumatismos do Braço/sangue , Fraturas Ósseas/urina , Humanos , Sulfeto de Hidrogênio/urina , Traumatismos da Perna/sangue , Osteogênese/fisiologia , Estudos Prospectivos , Fraturas da Coluna Vertebral/sangue
15.
Sci Total Environ ; 724: 137977, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32247972

RESUMO

The biogas produced in food waste anaerobic digestion (FWAD) contains H2S which can lead to corrosion, bad smell and poisoning accident. To control H2S pollution, the characteristics and mechanisms of H2S production in FWAD should be known. In this study, a lab-scale FWAD batch test was applied for 20 days under 35 °C. The production potential and average concentration of H2S were 765 ± 163 g/t (TS) and 1065 ± 267 ppm, respectively. 76% of total H2S was produced within 6 h on the first day of fermentation, acidification and gas production were key reasons for high H2S production at this time. Compared to H2S peak production time, that of methane was long (4 days) and after that of H2S. Sulfides were found to be the dominant form of sulfur (accounting for 20-70% of total sulfur) in the mixed fermentation liquor in fermentation batch. These sulfides were from protein, which could be decomposed slowly to sulfide by protein-using bacteria and methanogen at the time of methane production peak, and sulfate, which could be converted to sulfide by Sulfate reducing bacteria (SRB) during the first two days of fermentation. Protein would be the main contributor to sulfide/H2S for the continuous feeding FWAD system in long term operation, due to its presence as the main form of sulfur in food waste.


Assuntos
Sulfeto de Hidrogênio/análise , Eliminação de Resíduos , Anaerobiose , Biocombustíveis , Reatores Biológicos , Alimentos , Metano
16.
Chemosphere ; 253: 126687, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32298914

RESUMO

The impact on H2S alleviation and methane yield enhancement after submitting the anaerobic digestion of chicken manure to a finite amount of air was investigated. The largest reduction in the H2S biogas content (58% lower) occurred when air intensity of 30 ml/g VSin was injected into the reactors. Consequently, a maximum methane yield (335 mL-g VSin-1), which was 77% higher than the control, was concurrently achieved. Slight sulfate accumulation (<330 mg L-1) was observed inside the micro-aerated digesters with higher air intensities, suggesting a suppression of sulfide inhibition. Bacterial diversity/richness was enhanced in these digesters while the relative abundance of Methanocelleus increased by 36%. The most important contributing factor to enhancement was the synergistic effect resulting from increments in the hydrolysis rate and the suppression of sulfide inhibition. The results highlighted the potential of in situ H2S mitigation with the added benefit of methane yield enhancement.


Assuntos
Recuperação e Remediação Ambiental/métodos , Sulfeto de Hidrogênio/química , Anaerobiose , Animais , Bactérias , Biocombustíveis , Reatores Biológicos , Galinhas , Hidrólise , Esterco/microbiologia , Metano , Sulfatos
17.
Nihon Yakurigaku Zasshi ; 155(2): 74-79, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32115481

RESUMO

Recently, hydrogen sulfide (H2S) has been recognized as the third gasotransmitter besides nitric oxide and carbon monoxide, and it has been reported that H2S exhibits various physiological functions such as neuromodulation and vasorelaxation. In the lower urinary tract (bladder and prostate), it is reported that donors of H2S induce contraction of the rat detrusor and relaxation of the pig bladder neck. These reports suggest a possibility that H2S may have site-specific effects on the bladder. However, the detailed functions of H2S in each part of the bladder are still unclear. In addition, there is no report showing physiological roles of H2S in the prostate. In this article, we will review the distribution of enzymes related to H2S biosynthesis and physiological roles of H2S in the lower urinary tract based on reports from our and other groups. We will also introduce a possibility that H2S can be a new therapeutic target against lower urinary tract symptoms (LUTS) based on our data from spontaneously hypertensive rats (SHRs), which develop hypertension-mediated LUTS.


Assuntos
Sulfeto de Hidrogênio/metabolismo , Próstata/fisiologia , Bexiga Urinária/fisiologia , Animais , Masculino , Ratos , Ratos Endogâmicos SHR , Suínos
18.
Ecotoxicol Environ Saf ; 194: 110412, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32155482

RESUMO

Hydrogen sulfide (H2S) is a toxic air pollutant that causes immune damage. Recent studies have found that neutrophil extracellular trap (NET) formation is one way in which neutrophils exert immune functions. In addition, the formation of NETs is also related to thrombosis and autoimmune diseases. Recent studies have shown that miRNAs are involved in the regulation of a variety of pathophysiological processes. Here, we investigated the role of H2S in regulating the formation of NETs by affecting miR-16-5p. Our study established an in vitro H2S exposure model for neutrophils using phorbol-myristate-acetate (PMA) to induce NET formation. We observed the morphological changes of cells with scanning electron microscopy and fluorescence microscopy. Then, the content of extracellular DNA and the expression of MPO and NE in each group were detected. The results showed that H2S inhibited the formation of NETs. The expression of miR-16-5p and its target genes PiK3R1 and RAF1 was then measured by qRT-PCR. H2S upregulated miR-16-5p and inhibited expression of the target genes PiK3R1 and RAF1, and it subsequently inhibited the Pi3K/AKT and ERK pathways and decreased respiratory burst levels. Furthermore, H2S attenuated inositol 1,4,5-trisphosphate receptor (IP3R)-mediated endoplasmic reticulum calcium outflow as well as autophagy caused by PMA. This study enriches H2S immunotoxicity research and provides a possible solution for the treatment of NET-related diseases.


Assuntos
Poluentes Atmosféricos/toxicidade , Classe Ia de Fosfatidilinositol 3-Quinase/genética , Armadilhas Extracelulares/efeitos dos fármacos , Sulfeto de Hidrogênio/toxicidade , MicroRNAs/genética , Neutrófilos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-raf/genética , Animais , Autofagia/efeitos dos fármacos , Galinhas , Armadilhas Extracelulares/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Modelos Animais , Neutrófilos/metabolismo , Neutrófilos/ultraestrutura , Acetato de Tetradecanoilforbol/farmacologia , Ativação Transcricional/efeitos dos fármacos , Regulação para Cima
19.
Chemosphere ; 250: 126221, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32114337

RESUMO

This study demonstrates the full scale application of iron dosing in a metropolitan wastewater treatment plant (WWTP) and the upstream sewer system for multiple benefits. Two different dosing locations, i.e., the WWTP inlet works (Trial-1) and upstream sewer network (Trial-2) were tested in this study. Both dosing trials achieved multiple benefits such as sulfide control, phosphate removal and improved sludge dewaterability. During Trial-1, a sulfide reduction of >90% was achieved at high dosing rates (>19 kgFe ML-1) of ferrous chloride in the inlet works and in Trial-2 the in-sewer ferrous dosing had significant gas phase hydrogen sulfide (H2S) concentration reduction in the sewer network. The ferrous dosing enhanced the phosphate removal in the bioreactor up to 76% and 53 ± 2% during Trial-1 & 2, respectively. The iron ending up in the anaerobic sludge digester reduced the biogas H2S concentration by up to 36% and 45%, respectively. The dewaterability of the digested sludge was improved, with relative increases of 9.7% and 9.8%, respectively. The presence of primary clarifier showed limited impact on the downstream availability of iron for achieving the afore-mentioned multiple benefits. The iron dosing enhanced the total chemical oxygen demand removal in the primary clarifier reaching up to 49% at the high dose rates during Trial-1 and 42 ± 1% during Trial-2. This study demonstrated that multiple benefits could be achieved independent of the iron dosing location (i.e., at the WWTP inlet or in the network). Further, iron dosing at both locations enhances primary settling, beneficial for bioenergy recovery from wastewater.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , Compostos Ferrosos , Sulfeto de Hidrogênio , Ferro , Fosfatos , Esgotos , Sulfetos , Águas Residuárias
20.
Adv Exp Med Biol ; 1219: 335-353, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130707

RESUMO

Hydrogen sulfide (H2S), while historically perceived merely as a toxicant, has progressively emerged as a key regulator of numerous processes in mammalian physiology, exerting its signaling function essentially through interaction with and/or modification of proteins, targeting mainly cysteine residues and metal centers. As a gaseous signaling molecule that freely diffuses across aqueous and hydrophobic biological milieu, it has been designated the third 'gasotransmitter' in mammalian physiology. H2S is synthesized and detoxified by specialized endogenous enzymes that operate under a tight regulation, ensuring homeostatic levels of this otherwise toxic molecule. Indeed, imbalances in H2S levels associated with dysfunctional H2S metabolism have been growingly correlated with various human pathologies, from cardiovascular and neurodegenerative diseases to cancer. Several cancer cell lines and specimens have been shown to naturally overexpress one or more of the H2S-synthesizing enzymes. The resulting increased H2S levels have been proposed to promote cancer development through the regulation of various cancer-related processes, which led to the interest in pharmacological targeting of H2S metabolism. Herein are summarized some of the key observations that place H2S metabolism and signaling pathways at the forefront of the cellular mechanisms that support the establishment and development of a tumor within its complex and challenging microenvironment. Special emphasis is given to the mechanisms whereby H2S helps shaping cancer cell bioenergetic metabolism and affords resistance and adaptive mechanisms to hypoxia.


Assuntos
Sulfeto de Hidrogênio/metabolismo , Neoplasias/metabolismo , Transdução de Sinais , Microambiente Tumoral , Animais , Humanos , Neoplasias/enzimologia
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