RESUMO
Quenching is an important step to terminate disinfection during preparation of disinfected water samples for the analysis of disinfection byproducts (DBPs). However, an incomplete quenching might result in continued reactions of residual chlorine, whereas an excessive quenching might decompose target DBPs. Therefore, an adequate quenching to achieve simultaneous disinfection termination and DBP preservation is of particular importance. In this study, the two-stage reaction kinetics of chlorine and three commonly used quenching agents (i.e., ascorbic acid, sodium thiosulfate, and sodium sulfite) were determined. Stopping quenching during the first stage prevented interactions of residual chlorine with natural organic matter. Complete quenching was achieved by minimizing the quenching time for ascorbic acid and sodium sulfite, while limiting the quenching time to less than 3 min for sodium thiosulfate. At the optimized quenching times, the molar ratios (MRs) of quenching agent to chlorine were 1.05, 1.10, and 0.75 for ascorbic acid, sodium sulfite, and sodium thiosulfate, respectively. The destructive effects of the three quenching agents on total organic halogen (TOX) followed the rank order of ascorbic acid (33.7-64.8 %) < sodium sulfite (41.6-72.8 %) < sodium thiosulfate (43.3-73.2 %), and the destructive effects on aliphatic DBPs also followed the rank order of ascorbic acid (29.5-44.5 %) < sodium sulfite (34.9-51.9 %) < sodium thiosulfate (46.9-53.2 %). For total organic chlorine (TOCl) and aliphatic DBPs, the quenching behavior itself had more significant destructive effect than the quenching agent type/dose and quenching time, but for total organic bromine (TOBr), the destructive effect caused by quenching agent type/dose and quenching time was more significant. High-dose, long-duration quenching enhanced the reduction of TOX, but had little effect on aliphatic DBPs. Additionally, the three quenching agents reduced the levels of halophenols (except for tribromophenol), while maintained or increased the levels of tribromophenol, halobenzoic/salicylic acids, and halobenzaldehydes/salicylaldehydes. To achieve adequate quenching for overall DBP analysis in chlorinated water samples, it is recommended to use ascorbic acid at a quenching agent-to-chlorine MR of 1.0 for a quenching time of < 0.5 h.
Assuntos
Desinfetantes , Água Potável , Sulfitos , Tiossulfatos , Poluentes Químicos da Água , Purificação da Água , Água Potável/análise , Cloro/análise , Desinfetantes/análise , Halogênios/análise , Desinfecção , Cloretos , Ácido Ascórbico/análise , Poluentes Químicos da Água/análise , HalogenaçãoRESUMO
BACKGROUND: Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) is an effective treatment for peritoneal metastases. However, HIPEC with cisplatin is associated with renal toxicity. Sodium thiosulfate (ST) has been shown to prevent cisplatin-induced toxicity. METHODS: A retrospective, single-center analysis of patients treated curatively for peritoneal surface malignancy, who underwent cytoreductive surgery with cisplatin-based HIPEC between 2015 and 2020. Patients were categorized into three groups based on the management of cisplatin-induced renal toxicity: preoperative hyperhydration alone (PHH), preoperative hyperhydration with ST (PHH + ST), and ST alone. Renal function and complications, in terms of Acute (AKI) and chronic kidney injury (CKI), were monitored and analyzed during 3 postoperative months. RESULTS: This study included 220 consecutive patients. Mean serum creatinine levels were 95, 57 and 61 mmol/L, for PHH, PHH + ST and ST groups, respectively (p < 0.001). Glomerular Filtration Rate (GFR) were 96, 94 and 78 ml/min/1.73 m2, respectively (p < 0.001). AKI and CKI are respectively for PHH, PHH + ST and ST groups were 21 % (n = 46), 1 % (n = 2) and 0 % vs 19 % (n = 42), 0 % and 0 % (p < 0.001), for pairwise analysis did not show any difference between PHH + ST and ST alone combination, regarding nephrological outcomes. All patients were followed 3 months postoperatively. CONCLUSION: There is no need for preoperative hyperhydration when sodium-thiosulfate is used to prevent cisplatin-induced nephrotoxicity in patients undergoing cytoreductive surgery with HIPEC. These findings have implications for improving and simplifying the management of patients with peritoneal metastases undergoing HIPEC with cisplatin.
Assuntos
Injúria Renal Aguda , Antineoplásicos , Hipertermia Induzida , Neoplasias Peritoneais , Intoxicação por Água , Humanos , Cisplatino , Antineoplásicos/uso terapêutico , Tiossulfatos/uso terapêutico , Quimioterapia Intraperitoneal Hipertérmica/efeitos adversos , Estudos Retrospectivos , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Peritoneais/secundário , Intoxicação por Água/induzido quimicamente , Intoxicação por Água/complicações , Hipertermia Induzida/efeitos adversos , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/prevenção & controle , Procedimentos Cirúrgicos de Citorredução/efeitos adversos , Terapia Combinada , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Taxa de SobrevidaRESUMO
BACKGROUND: Calciphylaxis is a thrombotic vasculopathy characterized by painful necrotic ulcerations. There are no Food and Drug Administration approved therapies despite high mortality. OBJECTIVE: To compare mortality and wound healing outcomes in patients treated with hyperbaric oxygen therapy (HBOT) in addition to intravenous sodium thiosulfate (IV STS) versus patients who received IV STS only. Findings were stratified by dialysis status and modality. METHODS: 93 patients were included, with 57 patients in the control group (IV STS) and 36 patients in the treatment group (HBOT + IV STS). Mortality data were analyzed with traditional survival analyses and Cox proportional hazard models. Longitudinal wound outcomes were analyzed with mixed effects modeling. RESULTS: Univariate survival analyses showed that full HBOT treatment was associated with significantly (P = .016) longer survival time. Increasing number of HBOT sessions was associated with improved mortality outcomes, with 1, 5, 10 and 20 sessions yielding decreasing hazard ratios. There was also a significant (P = .042) positive association between increasing number of HBOT sessions and increased wound score. LIMITATIONS: Data collection was retrospective. CONCLUSION: HBOT may have a role in the treatment of calciphylaxis with benefits demonstrated in both mortality and wound healing. Larger prospective studies are needed to identify which patients would most benefit from this intervention.
Assuntos
Calciofilaxia , Oxigenoterapia Hiperbárica , Humanos , Estudos Retrospectivos , Calciofilaxia/terapia , Calciofilaxia/tratamento farmacológico , Tiossulfatos/uso terapêuticoRESUMO
Recently, increasing attention is given on the resource and energy recovery (e.g. short-chain fatty acids (SCFAs) and phosphorus (P)) from waste active sludge (WAS) under the "Dual carbon goals". This study compared four thiosulfate-assisted Fe2+/persulfate (TAFP) pretreatments of WAS, i.e. in-situ TAFP pretreatment (R1), ex-situ TAFP pretreatment (R2), in-situ TAFP pretreatment + pH adjustment (R3) and ex-situ TAFP pretreatment + pH adjustment (R4), followed by anaerobic fermentation over 20 days for SCFA production and P recovery. The results showed that the maximal SCFA yields in R1-4 were 730.2 ± 7.0, 1017.4 ± 13.9, 860.1 ± 40.8, and 1072.0 ± 33.2 mg COD/L, respectively, significantly higher than Control (365.2 ± 17.8 mg COD/L). The findings indicated that TAFP pretreatments (particularly ex-situ TAFP pretreatment) enhanced WAS disintegration and provided more soluble organics and subsequently promoted SCFA production. The P fractionation results showed the non-apatite inorganic P increased from 11.6 ± 0.2 mg P/g TSS in Control to 11.8 ± 0.5 (R1), 12.4 ± 0.3 (R2), 13.2 ± 0.7 (R3) and 12.7 ± 0.7 mg P/g TSS (R4), suggesting TAFP pretreatments improved P bioavailability due to formation of Fe-P mineral (Fe(H2PO4)2·2H2O), which could be recycled through magnetic separators. These findings were further strengthened by the analysis of microbial community and related marker genes that fermentative bacteria containing SCFA biosynthesis genes (e.g. pyk, pdhA, accA and accB) and iron-reducing bacteria containing iron-related proteins (e.g. feoA and feoB) were enriched in R1-4 (dominant in ex-situ pretreatment systems, R2 and R4). Economic evaluation further verified ex-situ TAFP pretreatment was cost-effective and a better strategy over other operations to treat WAS for SCFA production and P recovery.
Assuntos
Esgotos , Tiossulfatos , Fermentação , Esgotos/microbiologia , Anaerobiose , Ácidos Graxos Voláteis , Fósforo , Ferro , Concentração de Íons de HidrogênioRESUMO
Herein we demonstrate an enhanced performance of acid-assisted thiosulfate-impregnated spent/waste tea leaves (TWTL) for the removal of malachite green (MG) from water by batch mode. The material was characterized by pHZPC, FTIR, powder XRD, SEM, and proximate analysis. FTIR suggests the presence of polyphenolic moieties whereas a lignocellulosic peak was observed in powder XRD. SEM image shows a grafted surface texture with intermittent blocks, which upon dye uptake becomes somewhat condensed. Under optimized conditions, the highest removal efficiency of 126.8 mg/g was achieved at pH 7. A fast adsorption process was noticed with >97% removal within the first 10 min. Adsorption follows pseudo-second-order kinetics (R2 = 0.999) and the Langmuir model (R2 = 0.999). The material can be regenerated by dilute hydrochloric acid and can be reused for up to four cycles. Treatment of industrial effluent was successful in up to 47.56%. Our results highlight the potential of thiosulfate-treated spent tea leaves as a choice for the efficient removal of malachite green from water.
Tea, being one of the most popular beverages produces huge waste which requires proper management. With this aim; the thiosulfate-impregnated spent tea leaves have been exercised for effective separation of malachite green from contaminated water. Thiosulfate impregnation under mildly acidic conditions activates the tea leaves and makes the material robust with enhanced water stability than its untreated variety. With a remarkable maximum adsorption capacity of 126.8 mg/g under ambient conditions, the present methodology enjoys the edge over related phytosorbents. The protocol is techno-economic, environment friendly, and could be extended to possible field applications.
Assuntos
Poluentes Químicos da Água , Purificação da Água , Tiossulfatos , Pós , Purificação da Água/métodos , Biodegradação Ambiental , Cinética , Chá , Água , Adsorção , Poluentes Químicos da Água/química , Concentração de Íons de HidrogênioRESUMO
Antibiotics are the cornerstone of modern medicine and agriculture, and rising antibiotic resistance is one the biggest threats to global health and food security. Identifying new and different druggable targets for the development of new antibiotics is absolutely crucial to overcome resistance. Adjuvant strategies that either enhance the activity of existing antibiotics or improve clearance by the host immune system provide another mechanism to combat antibiotic resistance. Targeting a combination of essential and non-essential enzymes that play key roles in bacterial metabolism is a promising strategy to develop new antimicrobials and adjuvants, respectively. The enzymatic synthesis of L-cysteine is one such strategy. Cysteine plays a key role in proteins and is crucial for the synthesis of many biomolecules important for defense against the host immune system. Cysteine synthesis is a two-step process, catalyzed by two enzymes. Serine acetyltransferase (CysE) catalyzes the first step to synthesize the pathway intermediate O-acetylserine, and O-acetylserine sulfhydrylase (CysK/CysM) catalyzes the second step using sulfide or thiosulfate to produce cysteine. Disruption of the cysteine biosynthesis pathway results in dysregulated sulfur metabolism, altering the redox state of the cell leading to decreased fitness, enhanced susceptibility to oxidative stress and increased sensitivity to antibiotics. In this review, we summarize the structure and mechanism of characterized CysE and CysK/CysM enzymes from a variety of bacterial pathogens, and the evidence that support targeting these enzymes for the development of new antimicrobials or antibiotic adjuvants. In addition, we explore and compare compounds identified thus far that target these enzymes.
Assuntos
Cisteína Sintase , Serina O-Acetiltransferase , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias/metabolismo , Cisteína/metabolismo , Cisteína Sintase/química , Cisteína Sintase/genética , Farmacorresistência Bacteriana , Serina O-Acetiltransferase/química , Serina O-Acetiltransferase/metabolismo , Sulfetos , Enxofre/metabolismo , TiossulfatosRESUMO
Intermittent increases of dissolved ferrous iron concentrations have been observed in deep marine methanic sediments which is different from the traditional diagenetic electron acceptor cascade, where iron reduction precedes methanogenesis. Here we aimed to gain insight into the mechanism of iron reduction and the associated microbial processes in deep sea methanic sediment by setting up long-term high-pressure incubation experiments supplemented with ferrihydrite and methane. Continuous iron reduction was observed during the entire incubation period. Intriguingly, ferrihydrite addition shifted the archaeal community from the dominance of hydrogenotrophic methanogens (Methanogenium) to methylotrophic methanogens (Methanococcoides). The enriched samples were then amended with 13C-labeled methane and different iron (oxyhydr)oxides in batch slurries to test the mechanism of iron reduction. Intensive iron reduction was observed, the highest rates with ferrihydrite, followed by hematite and then magnetite, however, no anaerobic oxidation of methane (AOM) was observed in any treatment. Further tests on the enriched slurry showed that the addition of molybdate decreased iron reduction, suggesting a link between iron reduction with sulfur cycling. This was accompanied by the enrichment of microbes capable of dissimilatory sulfate reduction and sulfur/thiosulfate oxidation, which indicates the presence of a cryptic sulfur cycle in the incubation system with the addition of iron (oxyhydr)oxides. Our work suggests that under low sulfate conditions, the presence of iron (oxyhydr)oxides would trigger a cascade of microbial reactions, and iron reduction could link with the microbial sulfur cycle, changing the kinetics of the methanogenesis process in methanic sediment.
Assuntos
Ferro , Óxidos , Compostos Férricos , Óxido Ferroso-Férrico , Sedimentos Geológicos , Metano , Sulfatos , Enxofre , TiossulfatosRESUMO
The Permian Basin is the highest producing oil and gas reservoir in the United States. Hydrocarbon resources in this region are often accessed by unconventional extraction methods, including horizontal drilling and hydraulic fracturing. Despite the importance of the Permian Basin, there is no publicly available microbiological data from this region. We completed an analysis of Permian produced water samples to understand the dynamics present in hydraulically fractured wells in this region. We analyzed produced water samples taken from 10 wells in the Permian region of the Midland Basin using geochemical measurements, 16S rRNA gene sequencing, and metagenomic sequencing. Compared to other regions, we found that Permian Basin produced water was characterized by higher sulfate and lower total dissolved solids (TDS) concentrations, with a median of 1,110 mg/L and 107,000 mg/L. Additionally, geochemical measurements revealed the presence of frac hits, or interwell communication events where an established well is affected by the pumping of fracturing fluid into a new well. The occurrence of frac hits was supported by correlations between the microbiome and the geochemical parameters. Our 16S rRNA gene sequencing identified a produced water microbiome characterized by anaerobic, halophilic, and sulfur reducing taxa. Interestingly, sulfate and thiosulfate reducing taxa including Halanaerobium, Orenia, Marinobacter, and Desulfohalobium were the most prevalent microbiota in most wells. We further investigated the metabolic potential of microorganisms in the Permian Basin with metagenomic sequencing. We recovered 15 metagenome assembled genomes (MAGs) from seven different samples representing 6 unique well sites. These MAGs corroborated the high presence of sulfate and thiosulfate reducing genes across all wells, especially from key taxa including Halanaerobium and Orenia. The observed microbiome composition and metabolic capabilities in conjunction with the high sulfate concentrations demonstrate a high potential for hydrogen sulfide production in the Permian Basin. Additionally, evidence of frac hits suggests the possibility for the exchange of microbial cells and/or genetic information between wells. This exchange would increase the likelihood of hydrogen sulfide production and has implications for the oil and gas industry. IMPORTANCE The Permian Basin is the largest producing oil and gas region in the United States and plays a critical role supplying national energy needs. Previous work in other basins has demonstrated that the geochemistry and microbiology of hydrocarbon regions can have a major impact on well infrastructure and production. Despite that, little work has been done to understand the complex dynamics present in the Permian Basin. This study characterizes and analyzes 10 unique wells and one groundwater sample in the Permian Basin using geochemical and microbial techniques. Across all wells we found a high number of classic and thiosulfate reducers, suggesting that hydrogen sulfide production may be especially prevalent in the Permian Basin. Additionally, our analysis revealed a biogeochemical signal impacted by the presence of frac hits, or interwell communication events where an established well is affected by the pumping of fracturing fluid into a new well. This information can be utilized by the oil and gas industry to improve oil recovery efforts and minimize commercial and environmental costs.
Assuntos
Sulfeto de Hidrogênio , Microbiota , RNA Ribossômico 16S/genética , Sulfatos/química , Tiossulfatos , ÁguaRESUMO
PURPOSE: This study aimed to investigate the effects of AGE on microvascular reactivity, systolic blood pressure (SBP), and diastolic blood pressure (DBP) in older individuals at high risk for cardiovascular disease (CVD). Urinary thiosulfate was also investigated as an indirect marker of endogenous hydrogen sulfide (H2S) synthesis. The study was conducted in a randomized, double-blind, crossover, and placebo-controlled way. METHODS: Twenty-eight participants (14 male), 67 ± 6 years old with CVD risk factors, ingested 2.4 g of AGE or placebo (PLA). Near-infrared spectroscopy evaluated tissue oxygen saturation (StO2) during a vascular occlusion test (30 s baseline, 5 min occlusion, and 2 min reperfusion). The upslope of StO2 signal after cuff release was calculated to measure microvascular reactivity. Urinary thiosulfate levels were measured using a high-performance liquid chromatography system. RESULTS: The upslope of StO2 was significantly faster after AGE (1.01 ± 0.37% s-1) intake compared to PLA (0.83 ± 0.35% s-1; P < 0.001; d = 0.50). Relative changes in Δ% SBP from pre- to post-AGE intake (- 5.17 ± 5.77%) was significantly different compared to Δ% PLA (0.32 ± 5.99%; P = 0.001; d = 0.93). No significant changes in urinary thiosulfate concentrations were observed between interventions. Moreover, no significant gender effect in any parameter assessed was found. CONCLUSION: This study demonstrated that a single dose of AGE improved microvascular reactivity in older adults at risk of CVD despite such an effect was not linked with urinary thiosulfate levels. This trial was registered at clinicaltrials.gov as NCT04008693 (May 19, 2020).
Assuntos
Doenças Cardiovasculares , Alho , Sulfeto de Hidrogênio , Idoso , Doenças Cardiovasculares/prevenção & controle , Humanos , Sulfeto de Hidrogênio/metabolismo , Masculino , Microcirculação/fisiologia , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo , Consumo de Oxigênio/fisiologia , Extratos Vegetais/metabolismo , Poliésteres/metabolismo , Tiossulfatos/metabolismoRESUMO
This study aimed to effectively control the disease process of hemodialysis outpatients. Hemodialysis secondary hyperparathyroidism patients were randomly divided into the control group and treatment group. The control group was treated with routine treatment, and the treatment group was treated with sodium thiosulfate based on the control group. The changes of serum calcium, phosphorus, whole parathyroid hormone, calcium-phosphorus product and coronary artery calcification (CAC) score, as well as the relief of clinical symptoms, postoperative complications and recurrence in the preoperative and postoperative periods were observed. The levels of C-reactive protein and CAC scores were significantly decreased in the treatment group after treatment. While there was no significant difference in blood calcium, blood phosphorus, PTH, calcium-phosphorus product, and CAC score in the control group after treatment. And after treatment, the proportion of skin pruritus, myasthenia, bone pain, insomnia, restless legs syndrome, and other symptoms in the treatment group was significantly decreased compared with those before treatment, but there was no significant change in the control group before and after treatment. Sodium thiosulfate can reduce the high level of CAC in hemodialysis patients obviously.
Assuntos
Doença da Artéria Coronariana , Falência Renal Crônica , Cálcio/uso terapêutico , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/tratamento farmacológico , Humanos , Falência Renal Crônica/terapia , Fósforo/uso terapêutico , Diálise Renal/efeitos adversos , Tiossulfatos/uso terapêuticoRESUMO
Iodine is an essential component for fetal neurodevelopment and maternal thyroid function. Urine iodine is the most widely used indicator of iodine status. In this study, a novel validated ion-pair HPLC-UV method was developed to measure iodine concentration in clinical samples. A sodium thiosulfate solution was added to the urine sample to convert the total free iodine to iodide. Chromatographic separation was achieved in a Pursuit XRs C8 column. The mobile phase consisted of acetonitrile and a water phase containing 18-crown-6-ether, octylamine and sodium dihydrogen phosphate. Validation parameters, such as accuracy, precision, limits of detection and quantification, linearity and stability, were determined. Urinary samples from pregnant women were used to complete the validation and confirm the method's applicability. In the studied population of 93 pregnant women, the median UIC was lower in the group without iodine supplementation (117 µg/L, confidence interval (%CI): 95; 138) than in the supplement group (133 µg/L, %CI: 109; 157). In conclusion, the newly established ion-pair HPLC-UV method was adequately precise, accurate and fulfilled validation the criteria for analyzing compounds in biological fluids. The method is less complicated and expensive than other frequently used assays and permits the identification of the iodine-deficient subjects.
Assuntos
Iodo/análise , Iodo/urina , Adulto , Cromatografia Líquida de Alta Pressão/métodos , Suplementos Nutricionais , Feminino , Humanos , Iodetos/análise , Pessoa de Meia-Idade , Estado Nutricional , Polônia , Gravidez , Gestantes , Tiossulfatos/químicaRESUMO
Uremic pruritus is a distressful complication of chronic kidney disease and results in impaired quality of life and higher mortality rates. Intravenous sodium thiosulfate has been reported to alleviate pruritus in hemodialysis patients. We performed a systematic review and meta-analysis to estimate the efficacy of intravenous sodium thiosulfate in patients with uremic pruritus. A systematic search of electronic databases up to June 2021 was conducted for randomized controlled trials that evaluated the clinical effects of sodium thiosulfate in the management of patients with uremic pruritus. Two reviewers selected eligible articles and evaluated the risk of bias; the results of pruritus assessment and uremic pruritus-related laboratory parameters in selected studies were analyzed. There are four trials published between 2018 and 2021, which include 222 participants. The sodium thiosulfate group displayed significant decrease in the pruritus score (standardized mean difference = -3.52, 95% confidence interval = -5.63 to -1.41, p = 0.001), without a significant increase in the adverse effects (risk ratio = 2.44, 95% confidence interval = 0.37 to 15.99, p = 0.35) compared to the control group. Administration of sodium thiosulfate is found to be a safe and efficacious complementary therapy in improving uremic pruritus in patients with chronic kidney disease.
Assuntos
Antioxidantes/efeitos adversos , Prurido/tratamento farmacológico , Tiossulfatos/efeitos adversos , Uremia/tratamento farmacológico , Vasodilatadores/efeitos adversos , Antioxidantes/farmacologia , Humanos , Prurido/etiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Tiossulfatos/farmacologia , Uremia/complicações , Vasodilatadores/farmacologiaRESUMO
Kinetics of thiosulfate oxidation, product and intermediate formation, and 34S fractionation, were studied for the members of Alphaproteobacteria Paracoccus sp. SMMA5 and Mesorhizobium thiogangeticum SJTT, the Betaproteobacteria member Pusillimonas ginsengisoli SBO3, and the Acidithiobacillia member Thermithiobacillus sp. SMMA2, during chemolithoautotrophic growth in minimal salts media supplemented with 20 mM thiosulfate. The two Alphaproteobacteria oxidized thiosulfate directly to sulfate, progressively enriching the end-product with 34S; Δ34Sthiosulfate-sulfate values recorded at the end of the two processes (when no thiosulfate was oxidized any further) were -2.9 and -3.5, respectively. Pusillimonas ginsengisoli SBO3 and Thermithiobacillus sp. SMMA2, on the other hand, oxidized thiosulfate to sulfate via tetrathionate intermediate formation, with progressive 34S enrichment in the end-product sulfate throughout the incubation period; Δ34Sthiosulfate-sulfate, at the end of the two processes (when no further oxidation took place), reached -3.5 and -3.8, respectively. Based on similar 34S fractionation patterns recorded previously during thiosulfate oxidation by strains of Paracoccus pantotrophus, Advenella kashmirensis and Hydrogenovibrio crunogenus, it was concluded that progressive reverse fractionation, enriching the end-product sulfate with 34S, could be a characteristic signature of bacterial thiosulfate oxidation.
Assuntos
Proteobactérias/metabolismo , Isótopos de Enxofre/metabolismo , Tiossulfatos/metabolismo , Crescimento Quimioautotrófico , Cinética , Oxirredução , Filogenia , Proteobactérias/classificação , Proteobactérias/genética , Sulfatos/química , Sulfatos/metabolismo , Isótopos de Enxofre/químicaRESUMO
Pathological calcification is a major cause of cardiovascular morbidities primarily in population with chronic kidney disease (CKD), end stage renal diseases (ERSD) and metabolic disorders. Investigators have accepted the fact that vascular calcification is not a passive process but a highly complex, cell mediated, active process in patients with cardiovascular disease (CVD) resulting from, metabolic insults of bone fragility, diabetes, hypertension, dyslipidemia and atherosclerosis. Over the years, studies have revealed various mechanisms of vascular calcification like induction of bone formation, apoptosis, alteration in Ca-P balance and loss of inhibition. Novel clinical studies targeting cellular mechanisms of calcification provide promising and potential avenues for drug development. The interventions include phosphate binders, sodium thiosulphate, vitamin K, calcimimetics, vitamin D, bisphosphonates, Myoinositol hexaphosphate (IP6), Denosumab and TNAP inhibitors. Concurrently investigators are also working towards reversing or curing pathological calcification. This review focuses on the relationship of vascular calcification to clinical diseases, regulators and factors causing calcification including genetics which have been identified. At present, there is lack of any significant preventive measures for calcifications and hence this review explores further possibilities for drug development and treatment modalities.
Assuntos
Aterosclerose/tratamento farmacológico , Diabetes Mellitus/tratamento farmacológico , Dislipidemias/tratamento farmacológico , Hipertensão/tratamento farmacológico , Insuficiência Renal Crônica/tratamento farmacológico , Calcificação Vascular/tratamento farmacológico , Aterosclerose/metabolismo , Aterosclerose/patologia , Calcimiméticos/uso terapêutico , Cálcio/metabolismo , Denosumab/uso terapêutico , Diabetes Mellitus/metabolismo , Diabetes Mellitus/patologia , Difosfonatos/uso terapêutico , Dislipidemias/metabolismo , Dislipidemias/patologia , Inibidores Enzimáticos/uso terapêutico , Homeostase/efeitos dos fármacos , Hipertensão/metabolismo , Hipertensão/patologia , Fosfatos de Inositol/uso terapêutico , Fósforo/metabolismo , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/patologia , Tiossulfatos/uso terapêutico , Calcificação Vascular/metabolismo , Calcificação Vascular/patologia , Vitamina D/uso terapêutico , Vitamina K/uso terapêuticoRESUMO
Matcha and green tea catechins such as (-)-epicatechin (EC), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG) have long been studied for their antioxidant and health-promoting effects. Using specific fluorophores for H2S (AzMC) and polysulfides (SSP4) as well as IC-MS and UPLC-MS/MS-based techniques we here show that popular Japanese and Chinese green teas and select catechins all catalytically oxidize hydrogen sulfide (H2S) to polysulfides with the potency of EGC > EGCG >> EG. This reaction is accompanied by the formation of sulfite, thiosulfate and sulfate, consumes oxygen and is partially inhibited by the superoxide scavenger, tempol, and superoxide dismutase but not mannitol, trolox, DMPO, or the iron chelator, desferrioxamine. We propose that the reaction proceeds via a one-electron autoxidation process during which one of the OH-groups of the catechin B-ring is autooxidized to a semiquinone radical and oxygen is reduced to superoxide, either of which can then oxidize HS- to thiyl radicals (HSâ¢) which react to form hydrogen persulfide (H2S2). H2S oxidation reduces the B-ring back to the hydroquinone for recycling while the superoxide is reduced to hydrogen peroxide (H2O2). Matcha and catechins also concentration-dependently and rapidly produce polysulfides in HEK293 cells with the potency order EGCG > EGC > EG, an EGCG threshold of ~300 nM, and an EC50 of ~3 µM, suggesting green tea also acts as powerful pro-oxidant in vivo. The resultant polysulfides formed are not only potent antioxidants, but elicit a cascade of secondary cytoprotective effects, and we propose that many of the health benefits of green tea are mediated through these reactions. Remarkably, all green tea leaves constitutively contain small amounts of H2S2.
Assuntos
Catequina , Sulfeto de Hidrogênio , Antioxidantes/farmacologia , Catequina/farmacologia , Cromatografia Líquida , Células HEK293 , Humanos , Peróxido de Hidrogênio , Sulfetos , Espectrometria de Massas em Tandem , Chá , TiossulfatosRESUMO
BACKGROUND: Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has been shown to provide benefits in the management of peritoneal metastasis. Cisplatin (CDDP) is one of the most frequently used drugs for peritoneal infusion. A major restriction is that CDDP causes renal toxicity and acute renal failure, sometimes leading to chronic renal failure. The aim of the present study was to assess the impact of sodium thiosulfate (ST) in preventing renal impairment (RI) following HIPEC with CDDP. METHODS: This prospective study assessed the RI rates for all patients who underwent HIPEC with CDDP during two successive periods: without ST (nST Period; from November 2016 to September 2017) and with ST (ST Period; from October 2017 to March 2018). During the ST Period, patients received an ST infusion at 9 mg/m2 prior to HIPEC and at 12 mg/m2 at the end of the procedure. RI was defined by postoperative serum creatinine >1.6 times elevation of baseline value. The impact of ST treatment was evaluated by comparison of the RI rates between the two periods. RESULTS: During ST Period, none of 38 patients (0%) developed RI versus 11/35 patients (31.4%) during the nST Period (p < .005); 2 of whom required definitive hemodialysis. Baseline characteristics, background circumstances, indications and laboratory parameters before HIPEC were comparable between the two groups, as well as CDDP dose use during HIPEC. CONCLUSION: ST appears to be an effective drug for the prevention of the renal toxicity of CDDP used for HIPEC and should be used for all such procedures.
Assuntos
Antineoplásicos , Hipertermia Induzida , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica , Cisplatino/efeitos adversos , Terapia Combinada , Procedimentos Cirúrgicos de Citorredução , Humanos , Hipertermia Induzida/efeitos adversos , Quimioterapia Intraperitoneal Hipertérmica , Estudos Prospectivos , TiossulfatosRESUMO
Primary hyperoxaluria (PH) is a rare genetic disorder with autosomal recessive transmission, characterized by high endogenous production and markedly excessive urinary excretion of oxalate (Ox). It causes the accumulation of calcium oxide crystals in organs and tissues including bones, heart, arteries, skin and kidneys, where it may cause oxalo-calcic nephrolithiasis, nephrocalcinosis and chronic renal failure. Some forms are secondary to enteric diseases, drugs or dietetic substances, while three primitive forms, caused by various enzymatic defects, are currently known: PH1, PH2 and PH3. An early diagnosis, with the aid of biochemical and genetic investigations, helps prevent complications and establish a therapeutic strategy that often includes liver and liver-kidney transplantation, improving the prognosis of these patients. In this work we describe the clinical case of a patient with PH1 undergoing extracorporeal hemodialysis treatment and we report the latest research results that could change the life of patients with PH.
Assuntos
Calciofilaxia/terapia , Hiperoxalúria Primária/genética , Hiperoxalúria Primária/terapia , Diálise Renal/métodos , Dermatopatias Metabólicas/terapia , Transaminases/genética , Calciofilaxia/etiologia , Calciofilaxia/patologia , Compostos de Cálcio/metabolismo , Feminino , Glioxilatos/metabolismo , Hemodiafiltração/métodos , Humanos , Hiperoxalúria Primária/diagnóstico , Falência Renal Crônica/etiologia , Transplante de Rim , Pessoa de Meia-Idade , Nefrocalcinose/etiologia , Nefrocalcinose/terapia , Uso Off-Label , Oxalatos/metabolismo , Óxidos/metabolismo , Dermatopatias Metabólicas/etiologia , Dermatopatias Metabólicas/patologia , Tiossulfatos/uso terapêuticoRESUMO
BACKGROUND AND OBJECTIVES: Hyperthermic intrathoracic chemotherapy (HITOC) is used for the treatment of malignant pleural tumors. Although HITOC proved to be safe, postoperative renal failure due to nephrotoxicity of intrapleural cisplatin remains a concern. METHODS: This single-center study was performed retrospectively in patients who underwent pleural tumor resection and HITOC between September 2008 and December 2018. RESULTS: A total of 84 patients (female n = 33; 39.3%) with malignant pleural tumors underwent surgical cytoreduction with subsequent HITOC (60 minutes; 42°C). During the study period, we gradually increased the dosage of cisplatin (100-150 mg/m2 BSA n = 36; 175 mg/m2 BSA n = 2) and finally added doxorubicin (cisplatin 175 mg/m2 BSA/doxorubicin 65 mg; n = 46). All patients had perioperative fluid balancing. The last 54 (64.3%) patients also received perioperative cytoprotection. Overall 29 patients (34.5%) experienced renal insufficiency. Despite higher cisplatin concentrations, patients with cytoprotection showed significantly lower postoperative serum creatinine levels after 1 week (P = .006) and at discharge (P = .020). Also, they showed less intermediate and severe renal insufficiencies (5.6% vs 13.3%). CONCLUSIONS: Adequate perioperative fluid management and cytoprotection seem to be effective in protecting renal function. This allows the administration of higher intracavitary cisplatin doses without raising the rate of renal insufficiencies.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Quimioterapia do Câncer por Perfusão Regional/efeitos adversos , Hipertermia Induzida/efeitos adversos , Mesotelioma/terapia , Néfrons/efeitos dos fármacos , Neoplasias Pleurais/terapia , Substâncias Protetoras/administração & dosagem , Insuficiência Renal Crônica/tratamento farmacológico , Amifostina/administração & dosagem , Cisplatino/administração & dosagem , Terapia Combinada , Creatinina/sangue , Citoproteção , Doxorrubicina/administração & dosagem , Feminino , Seguimentos , Humanos , Masculino , Mesotelioma/patologia , Pessoa de Meia-Idade , Neoplasias Pleurais/patologia , Cuidados Pós-Operatórios , Prognóstico , Insuficiência Renal Crônica/induzido quimicamente , Insuficiência Renal Crônica/patologia , Estudos Retrospectivos , Taxa de Sobrevida , Tiossulfatos/administração & dosagem , Cavidade Torácica/cirurgiaRESUMO
Microbially influenced corrosion (MIC) results in significant damage to metallic materials in many industries. Anaerobic sulfate-reducing bacteria (SRB) have been well studied for their involvement in these processes. Highly corrosive environments are also found in pulp and paper processing, where chloride and thiosulfate lead to the corrosion of stainless steels. Acidithiobacillus ferrooxidans is a critically important chemolithotrophic acidophile exploited in metal biomining operations, and there is interest in using A. ferrooxidans cells for emerging processes such as electronic waste recycling. We explored conditions under which A. ferrooxidans could enable the corrosion of stainless steel. Acidic medium with iron, chloride, low sulfate, and pyrite supplementation created an environment where unstable thiosulfate was continuously generated. When combined with the chloride, acid, and iron, the thiosulfate enabled substantial corrosion of stainless steel (SS304) coupons (mass loss, 5.4 ± 1.1 mg/cm2 over 13 days), which is an order of magnitude higher than what has been reported for SRB. There results were verified in an abiotic flow reactor, and the importance of mixing was also demonstrated. Overall, these results indicate that A. ferrooxidans and related pyrite-oxidizing bacteria could produce aggressive MIC conditions in certain environmental milieus.IMPORTANCE MIC of industrial equipment, gas pipelines, and military material leads to billions of dollars in damage annually. Thus, there is a clear need to better understand MIC processes and chemistries as efforts are made to ameliorate these effects. Additionally, A. ferrooxidans is a valuable acidophile with high metal tolerance which can continuously generate ferric iron, making it critical to copper and other biomining operations as well as a potential biocatalyst for electronic waste recycling. New MIC mechanisms may expand the utility of these cells in future metal resource recovery operations.
Assuntos
Acidithiobacillus/metabolismo , Ferro/química , Aço Inoxidável/química , Sulfatos/química , Tiossulfatos/química , Ligas , Crescimento Quimioautotrófico , Cobre , Corrosão , Elétrons , Microbiologia Industrial , Mineração , Oxidantes , Oxirredução , Sulfetos , Propriedades de SuperfícieRESUMO
Inhalation injury is often associated with burns and significantly increases morbidity and mortality. The main toxic components of fire smoke are carbon monoxide, hydrogen cyanide, and irritants. In the case of an incident at a nuclear power plant or recycling facility associated with fire, smoke may also contain radioactive material. Medical treatments may vary in different countries, and in this paper, we discuss the similarities and differences in the treatments between China and Germany. Carbon monoxide poisoning is treated by 100% oxygen administration and, if available, hyperbaric oxygenation in China as well as in Germany. In addition, antidotes binding the cyanide ions and relieving the respiratory chain are important. Methemoglobin-forming agents (e.g., nitrites, dimethylaminophenol) or hydroxocobalamin (Vitamin B12) are options. The metabolic elimination of cyanide may be enhanced by sodium thiosulfate. In China, sodium nitrite with sodium thiosulfate is the most common combination. The use of dimethylaminophenol instead of sodium nitrite is typical for Germany, and hydroxocobalamin is considered the antidote of choice if available in cases of cyanide intoxications by fire smoke inhalation as it does not further reduce oxygen transport capacity. Systematic prophylactic use of corticosteroids to prevent toxic pulmonary edema is not recommended in China or Germany. Stable iodine is indicated in the case of radioiodine exposure and must be administered within several hours to be effective. The decorporation of metal radionuclides is possible with Ca (DTPA) or Prussian blue that should be given as soon as possible. These medications are used in both countries, but it seems that Ca (DTPA) is administered at lower dosages in China. Although the details of the treatment of inhalation injury and radionuclide(s) decorporation may vary, the general therapeutic strategy is very similar in China and Germany.