-
1.
Experimental study of the remediation of acid mine drainage by Maifan stones combined with SRB.
Guo, X, Hu, Z, Fu, S, Dong, Y, Jiang, G, Li, Y
PloS one. 2022;(1):e0261823
Abstract
The problems of acid mine drainage (AMD) in coal mine acidic wastewaters arise from a range of sources, including severe pollution with heavy metals and SO42- and difficulties during treatment. Based on the ability of Maifan stone to adsorb heavy metals and the dissimilatory reduction of SO42- by sulfate-reducing bacteria (SRB), Maifan stone-sulfate-reducing bacterium-immobilized particles were prepared via immobilization techniques using Shandong Maifan stone as the experimental material. The effects of Maifan stones containing SRB on mitigating AMD were investigated by constructing Dynamic Column 1 with Maifan stone-sulfate-reducing bacterium-immobilized particles and by constructing Dynamic Column 2 with SRB mixed with Maifan stones. By the use of adsorption isotherms, adsorption kinetics, a reduction kinetics model and X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies, the mechanism by which Maifan stone-sulfate-reducing bacterium-immobilized particles mitigate AMD was revealed. The results showed that the total effect of Maifan stone-sulfate-reducing bacterium-immobilized particles on AMD was better than that of biological Maifan stone carriers. The highest rates for the removal of Fe2+, Mn2+, and SO42- in AMD were 90.51%, 85.75% and 93.61%, respectively, and the pH value of the wastewater increased from 4.08 to 7.64. The isotherms for the adsorption of Fe2+ and Mn2+ on Maifan stone-sulfate-reducing bacterium-immobilized particles conformed to the output of the Langmuir model. The adsorption kinetics were in accordance with Lagergren first-order kinetics, and the kinetics for the reduction of SO42- conformed to those of a first-order reaction model.
-
2.
The clinical efficacy of external application of mirabilite and rhubarb combined with intrathoracic chemotherapy in treating malignant pleural effusion: A prospective, randomized, controlled clinical trial.
Zhang, H, Jiang, M, Gao, L, Lin, Z
Medicine. 2021;(7):e24758
-
-
Free full text
-
Abstract
BACKGROUND Malignant pleural effusion (MPE) is one of the commonest causes of an exudative pleural effusion. Breathlessness, dyspnea and other symptoms often seriously distress and affect the quality of life. The external application of mirabilite and rhubarb (EAMR) combined with intrathoracic infusion of cisplatin, as an alternative treatment for MPE, is popular in China. The study aims to assess its effectiveness and safety combined with intrathoracic chemotherapy. METHODS This study is a prospective, randomized controlled clinical trial. Patient visits were performed at baseline and days 14 and 28 after treatment. Clinical outcomes were measured after chest drain placement using the criterion of efficacy refer to WHO standard, and QLQ-C30 questionnaire. RESULTS Database records of patients treated in our institution for MPE between October, 2016 and March, 2019. The study included 84 eligible patients. They were categorized with a randomization schedule into treatment group (N = 42) and control group (N = 42). There is statistical significance in the comparison of the total effective rate between these 2 groups (66.67% vs 54.76%, P < .05). Furthermore, there is statistical significance in the comparison of items of Physical (1.95 ± 0.50 vs 2.19 ± 0.58%, P < .05), Pain (1.98 ± 0.42 vs 2.07 ± 0.32, P < .05), and Global Health (1.23 ± 0.64 vs 1.13 ± 0.23%, P < .05) between these 2 groups. None of the patients had adverse reactions such as skin allergy and chest tightness. CONCLUSIONS The total effective rate of treatment group using extra external application of mirabilite rhubarb powder is significantly higher than that of control group. The improvement of patients' clinical symptoms is greater in treatment group and no adverse reactions is found. Therefore, external application of mirabilite and rhubarb combined with intrathoracic infusion of cisplatin is an effective method for the treatment of MPE, which is worth popularizing.
-
3.
Biogeochemical dynamics and microbial community development under sulfate- and iron-reducing conditions based on electron shuttle amendment.
Flynn, TM, Antonopoulos, DA, Skinner, KA, Brulc, JM, Johnston, E, Boyanov, MI, Kwon, MJ, Kemner, KM, O'Loughlin, EJ
PloS one. 2021;(5):e0251883
Abstract
Iron reduction and sulfate reduction are two of the major biogeochemical processes that occur in anoxic sediments. Microbes that catalyze these reactions are therefore some of the most abundant organisms in the subsurface, and some of the most important. Due to the variety of mechanisms that microbes employ to derive energy from these reactions, including the use of soluble electron shuttles, the dynamics between iron- and sulfate-reducing populations under changing biogeochemical conditions still elude complete characterization. Here, we amended experimental bioreactors comprised of freshwater aquifer sediment with ferric iron, sulfate, acetate, and the model electron shuttle AQDS (9,10-anthraquinone-2,6-disulfonate) and monitored both the changing redox conditions as well as changes in the microbial community over time. The addition of the electron shuttle AQDS did increase the initial rate of FeIII reduction; however, it had little effect on the composition of the microbial community. Our results show that in both AQDS- and AQDS+ systems there was an initial dominance of organisms classified as Geobacter (a genus of dissimilatory FeIII-reducing bacteria), after which sequences classified as Desulfosporosinus (a genus of dissimilatory sulfate-reducing bacteria) came to dominate both experimental systems. Furthermore, most of the ferric iron reduction occurred under this later, ostensibly "sulfate-reducing" phase of the experiment. This calls into question the usefulness of classifying subsurface sediments by the dominant microbial process alone because of their interrelated biogeochemical consequences. To better inform models of microbially-catalyzed subsurface processes, such interactions must be more thoroughly understood under a broad range of conditions.
-
4.
Sulfation predominates the pharmacokinetics, metabolism, and excretion of forsythin in humans: major enzymes and transporters identified.
Pan, LL, Yang, Y, Hui, M, Wang, S, Li, CY, Zhang, H, Ding, YH, Fu, L, Diao, XX, Zhong, DF
Acta pharmacologica Sinica. 2021;(2):311-322
-
-
Free full text
-
Abstract
Forsythin extracted from Forsythiae Fructus is widely used to treat fever caused by the common cold or influenza in China, Japan and Korea. The present study aimed to analyze the pharmacokinetics, metabolism and excretion routes of forsythin in humans and determine the major enzymes and transporters involved in these processes. After a single oral administration, forsythin underwent extensive metabolism via hydrolysis and further sulfation. In total, 3 of the 13 metabolites were confirmed by comparison to reference substances, i.e., aglycone M1, M1 sulfate (M2), and M1 glucuronide (M7). Hydrolysis was the initial and main metabolic pathway of the parent compound, followed by extensive sulfation to form M2 and a reduced level of glucuronidation to form M7. In addition, the plasma exposure of M2 and M7 were 86- and 4.2-fold higher than that of forsythin. Within 48 h, ~75.1% of the administered dose was found in urine, with M2 accounting for 71.6%. Further phenotyping experiments revealed that sulfotransferase 1A1 and UDP-glucuronosyltransferase 1A8 were the most active hepatic enzymes involved in the formation of M2 and M7, respectively. The in vitro kinetic study provided direct evidence that M1 showed a preference for sulfation. Sulfated conjugate M2 was identified as a specific substrate of organic anion transporter 3, which could facilitate the renal excretion of M2. Altogether, our study demonstrated that sulfation dominated the metabolism and pharmacokinetics of forsythin, while the sulfate conjugate was excreted mainly in the urine.
-
5.
Human hepatic microsomal sulfatase catalyzes the hydrolysis of polychlorinated biphenyl sulfates: A potential mechanism for retention of hydroxylated PCBs.
Duffel, MW, Tuttle, K, Lehmler, HJ, Robertson, LW
Environmental toxicology and pharmacology. 2021;:103757
-
-
Free full text
-
Abstract
Polychlorinated biphenyls (PCBs) are persistent environmental contaminants that continue to be of concern due to their varied toxicities. Upon human exposure, many PCBs with lower numbers of chlorine atoms are metabolized to hydroxylated derivatives (OH-PCBs), and cytosolic sulfotransferases can subsequently catalyze the formation of PCB sulfates. Recent studies have indicated that PCB sulfates bind reversibly with a high affinity to human serum proteins, and that they are also taken up by cells and tissues. Since PCB sulfates might be hydrolyzed to the more toxic OH-PCBs, we have investigated the ability of human hepatic microsomal sulfatase to catalyze this reaction. Twelve congeners of PCB sulfates were substrates for the microsomal sulfatase with catalytic rates exceeding that of dehydroepiandrosterone sulfate as a comparison substrate for steroid sulfatase (STS). These results are consistent with an intracellular mechanism for sulfation and de-sulfation that may contribute to retention and increased time of exposure to OH-PCBs.
-
6.
Root meristem growth factor RGF, a sulfated peptide hormone in plants.
Shinohara, H
Peptides. 2021;:170556
Abstract
In recent decades, small secreted peptides have been recognized as a new class of intercellular signaling phytohormones in plants. Tyrosine sulfation plays crucial roles in peptide hormone bioactivities in plants. The Arabidopsis tyrosylprotein sulfotransferase mutant tpst-1 causes severe abnormalities in the root tip due to deficiency in the biosynthesis of all functional tyrosine-sulfated peptides. Root meristem growth factor RGF, a sulfated peptide hormone specifically expressed in the root tip, was found to complement tpst-1 root defects. This review summarizes the history of the identification of RGF, the characteristics of RGF, the identification of RGF receptors, and the target of RGF. In brief, RGF is a 13 amino acid sulfated peptide. The RGF peptide mutant rgf1,2,3 exhibited a reduced size of the root apical meristem, indicating that RGF maintains cell proliferation activity in the root apical meristem. RGF receptors were identified by comprehensive binding analysis with a custom-made receptor expression library. The RGF receptor mutant rgfr1,2,3 showed a phenotype of reduced root length due to a reduction in the root apical meristem and was insensitive to RGF. The signaling cascade through RGF-RGF receptor pairs regulates the gradient formation of PLETHORA (PLT), which is known as the master regulator of root formation. In the peptide mutant rgf1,2,3 and receptor mutant rgfr1,2,3, the gradient of PLT proteins disappeared, indicating that RGF defines the PLT protein gradient to ensure robust root growth and root development. Recent studies of the downstream signaling of RGF-RGF receptor pairs are also described in this review.
-
7.
A Safety and Efficacy Comparison of a New Sulfate-Based Tablet Bowel Preparation Versus a PEG and Ascorbate Comparator in Adult Subjects Undergoing Colonoscopy.
Di Palma, JA, Bhandari, R, Cleveland, MV, Mishkin, DS, Tesoriero, J, Hall, S, McGowan, J
The American journal of gastroenterology. 2021;(2):319-328
-
-
Free full text
-
Abstract
INTRODUCTION A new tablet-based bowel prep for colonoscopy has been developed containing poorly absorbed sulfate salts which act to retain water within the intestinal lumen resulting in a copious diarrhea, thereby cleansing the bowel. This study evaluated the safety and efficacy of these oral sulfate tablets (OST) compared with a US FDA-approved bowel prep solution containing PEG3350, electrolytes, and ascorbate (polyethylene glycol and ascorbate [PEG-EA]). METHODS Five hundred fifteen adult patients (mean 57y) were enrolled in this single-blind, multicenter, noninferiority study. Subjects were assigned either PEG-EA or OST to be administered in a split-dose regimen starting the evening before colonoscopy. PEG-EA was taken according to its approved labeling (1 L of prep solution with 16 oz. of additional water) in the evening and again in the morning. OST patients took a total of 24 tablets. OST patients were administered 12 tablets in the evening, and the following morning. Patients consumed 16 ounces of water with each dose of 12 tablets and drank an additional 32 oz. of water with each dose. Colonoscopies were performed by blinded investigators. Cleansing efficacy was evaluated globally and segmentally using a 4-point scale (Excellent-no more than small bits of feces/fluid which can be suctioned easily; achieves clear visualization of the entire colonic mucosa. Good-feces and fluid requiring washing and suctioning, but still achieves clear visualization of the entire colonic mucosa. Fair-enough feces even after washing and suctioning to prevent clear visualization of the entire colonic mucosa. Poor-large amounts of fecal residue and additional bowel preparation required). Scores of Good or Excellent were considered to be a success. Safety was assessed by spontaneously reported adverse events, solicited ratings of expected prep symptoms, and laboratory testing. RESULTS A high rate of cleansing success was seen with OST (92%), which was noninferior to PEG-EA (89%). Only a small proportion of subjects rated their expected gastrointestinal symptoms as severe (<5% for both preps). No clinically significant differences were seen between preps for chemistry and hematology parameters. No serious adverse experiences were reported with OST. DISCUSSION Sulfate tablets achieved a high level of cleansing in the study, comparable with US FDA-approved preps. OST was noninferior to PEG-EA in this study and achieved significantly more Excellent preps overall and in the proximal colon. The OST prep was well-tolerated, with a similar rate of spontaneously reported adverse experiences to PEG-EA and a low rate of severe expected gastrointestinal symptoms.
-
8.
Dynamic modeling of anaerobic methane oxidation coupled to sulfate reduction: role of elemental sulfur as intermediate.
Hatzikioseyian, A, Bhattarai, S, Cassarini, C, Esposito, G, Lens, PNL
Bioprocess and biosystems engineering. 2021;(4):855-874
Abstract
The process dynamics of anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR), and the potential role of elemental sulfur as intermediate are presented in this paper. Thermodynamic screening and experimental evidence from the literature conclude that a prominent model to describe AOM-SR is based on the concept that anaerobic methane oxidation proceeds through the production of the intermediate elemental sulfur. Two microbial groups are involved in the process: (a) anaerobic methanotrophs (ANME-2) and (b) Desulfosarcina/Desulfococcus sulfur reducers cluster (DSS). In this work, a dynamic model was developed to explore the interactions between biotic and abiotic processes to simulate the microbial activity, the chemical composition and speciation of the liquid phase, and the gas phase composition in the reactor headspace. The model includes the microbial kinetics for the symbiotic growth of ANME-2 and DSS, mass transfer phenomena between the gas and liquid phase for methane, hydrogen sulfide, and carbon dioxide and acid-base reactions for bicarbonate, sulfide, and ammonium. A data set from batch experiments, running for 250 days in artificial seawater inoculated with sediment from Marine Lake Grevelingen (The Netherlands) was used to calibrate the model. The inherent characteristics of AOM-SR make the identification of the kinetic parameters difficult due to the high correlation between them. However, by meaningfully selecting a set of kinetic parameters, the model simulates successfully the experimental data for sulfate reduction and sulfide production. The model can be considered as the basic structure for simulating continuous flow three-phase engineered systems based on AOM-SR.
-
9.
Comparative metabolic modeling of multiple sulfate-reducing prokaryotes reveals versatile energy conservation mechanisms.
Tang, WT, Hao, TW, Chen, GH
Biotechnology and bioengineering. 2021;(7):2676-2693
Abstract
Sulfate-reducing prokaryotes (SRPs) are crucial participants in the cycling of sulfur, carbon, and various metals in the natural environment and in engineered systems. Despite recent advances in genetics and molecular biology bringing a huge amount of information about the energy metabolism of SRPs, little effort has been made to link this important information with their biotechnological studies. This study aims to construct multiple metabolic models of SRPs that systematically compile genomic, genetic, biochemical, and molecular information about SRPs to study their energy metabolism. Pan-genome analysis was conducted to compare the genomes of SRPs, from which a list of orthologous genes related to central and energy metabolism was obtained. Twenty-four SRP metabolic models via the inference of pan-genome analysis were efficiently constructed. The metabolic model of the well-studied model SRP Desulfovibrio vulgaris Hildenborough (DvH) was validated via flux balance analysis (FBA). The DvH model predictions matched reported experimental growth and energy yields, which demonstrated that the core metabolic model worked successfully. Further, steady-state simulation of SRP metabolic models under different growth conditions showed how the use of different electron transfer pathways leads to energy generation. Three energy conservation mechanisms were identified, including menaquinone-based redox loop, hydrogen cycling, and proton pumping. Flavin-based electron bifurcation (FBEB) was also demonstrated to be an essential mechanism for supporting energy conservation. The developed models can be easily extended to other species of SRPs not examined in this study. More importantly, the present work develops an accurate and efficient approach for constructing metabolic models of multiple organisms, which can be applied to other critical microbes in environmental and industrial systems, thereby enabling the quantitative prediction of their metabolic behaviors to benefit relevant applications.
-
10.
Novel sulfate tablet PBK-1701TC versus oral sulfate solution for colon cleansing: A randomized phase 3 trial.
Yang, HJ, Park, DI, Park, SK, Lee, CK, Kim, HJ, Oh, SJ, Moon, JR, Lee, BJ, Koh, JS, Kim, HS, et al
Journal of gastroenterology and hepatology. 2020;(1):29-36
Abstract
BACKGROUND AND AIM PBK-1701TC is a novel sulfate tablet-based that contains 320 mg of simethicone and delivers 90% of the salt and water delivered by oral sulfate solution (OSS) preparation. This study evaluated the efficacy, safety, and tolerability of PBK-1701TC compared with OSS in bowel preparation for colonoscopy. METHODS This randomized, multicenter, phase 3 non-inferiority trial included adults aged 19 years or older with a body mass index of 19-30 kg/m2 undergoing colonoscopy at five university hospitals in Korea. The primary efficacy endpoint was successful bowel-cleansing rate, defined as Harefield Cleansing Scale grade A or B as evaluated by blinded central readers. Secondary endpoints included the presence of residual air bubbles. Adverse events and laboratory evaluations were monitored to assess safety. Tolerability was assessed via participant interview. RESULTS Overall, 235 participants were randomized, and 224 were included in the per-protocol analysis (PBK, 112; OSS, 112). Successful bowel cleansing was achieved for 95.5% (107/112) in the PBK group, which was non-inferior to the OSS group (98.2%, 110/112) with a difference of -2.7% (one sided 97.5% confidence limit, -8.1%). The participants in the PBK group had fewer intraluminal bubbles (0.9% vs 81.3%, P < 0.001) and reported a lower incidence of nausea and vomiting, with better acceptance, taste, and willingness to repeat the regimen than those in the OSS group (all P < 0.05). CONCLUSION The novel sulfate tablet, PBK-1701TC, was non-inferior to OSS with respect to bowel-cleansing efficacy and exhibited better safety and tolerability in adults undergoing colonoscopy.