Structural and mechanistic basis of the central energy-converting methyltransferase complex of methanogenesis.

Methanogenic archaea inhabiting anaerobic environments play a crucial role in the global biogeochemical material cycle. The most universal electrogenic reaction of their methane-producing energy metabolism is catalyzed by N    5-methyl-tetrahydromethanopterin: coenzyme M methyltransferase (MtrABCDEFGH), which couples the vectorial Na+ transport with a methyl transfer between the one-carbon carriers tetrahydromethanopterin and coenzyme M via a vitamin B12 derivative (cobamide) as prosthetic group. We present the 2.08 Šcryo-EM structure of Mtr(ABCDEFG)3 composed of the central Mtr(ABFG)3 stalk symmetrically flanked by three membrane-spanning MtrCDE globes. Tetraether glycolipids visible in the map fill gaps inside the multisubunit complex. Putative coenzyme M and Na+ were identified inside or in a side-pocket of a cytoplasmic cavity formed within MtrCDE. Its bottom marks the gate of the transmembrane pore occluded in the cryo-EM map. By integrating Alphafold2 information, functionally competent MtrA-MtrH and MtrA-MtrCDE subcomplexes could be modeled and thus the methyl-tetrahydromethanopterin demethylation and coenzyme M methylation half-reactions structurally described. Methyl-transfer-driven Na+ transport is proposed to be based on a strong and weak complex between MtrCDE and MtrA carrying vitamin B12, the latter being placed at the entrance of the cytoplasmic MtrCDE cavity. Hypothetically, strongly attached methyl-cob(III)amide (His-on) carrying MtrA induces an inward-facing conformation, Na+ flux into the membrane protein center and finally coenzyme M methylation while the generated loosely attached (or detached) MtrA carrying cob(I)amide (His-off) induces an outward-facing conformation and an extracellular Na+ outflux. Methyl-cob(III)amide (His-on) is regenerated in the distant active site of the methyl-tetrahydromethanopterin binding MtrH implicating a large-scale shuttling movement of the vitamin B12-carrying domain.

Anaerobic hexadecane degradation by a thermophilic Hadarchaeon from Guaymas Basin.

Hadarchaeota inhabit subsurface and hydrothermally heated environments, but previous to this study, they had not been cultured. Based on metagenome-assembled genomes, most Hadarchaeota are heterotrophs that grow on sugars and amino acids, or oxidize carbon monoxide or reduce nitrite to ammonium. A few other metagenome-assembled genomes encode alkyl-coenzyme M reductases (Acrs), ß-oxidation, and Wood-Ljungdahl pathways, pointing toward multicarbon alkane metabolism. To identify the organisms involved in thermophilic oil degradation, we established anaerobic sulfate-reducing hexadecane-degrading cultures from hydrothermally heated sediments of the Guaymas Basin. Cultures at 70°C were enriched in one Hadarchaeon that we propose as Candidatus Cerberiarchaeum oleivorans. Genomic and chemical analyses indicate that Ca. C. oleivorans uses an Acr to activate hexadecane to hexadecyl-coenzyme M. A ß-oxidation pathway and a tetrahydromethanopterin methyl branch Wood-Ljungdahl (mWL) pathway allow the complete oxidation of hexadecane to CO2. Our results suggest a syntrophic lifestyle with sulfate reducers, as Ca. C. oleivorans lacks a sulfate respiration pathway. Comparative genomics show that Acr, mWL, and ß-oxidation are restricted to one family of Hadarchaeota, which we propose as Ca. Cerberiarchaeaceae. Phylogenetic analyses further indicate that the mWL pathway is basal to all Hadarchaeota. By contrast, the carbon monoxide dehydrogenase/acetyl-coenzyme A synthase complex in Ca. Cerberiarchaeaceae was horizontally acquired from Bathyarchaeia. The Acr and ß-oxidation genes of Ca. Cerberiarchaeaceae are highly similar to those of other alkane-oxidizing archaea such as Ca. Methanoliparia and Ca. Helarchaeales. Our results support the use of Acrs in the degradation of petroleum alkanes and suggest a role of Hadarchaeota in oil-rich environments.

Teaching ultrasound in osteopathic medical schools.

CONTEXT: An important diagnostic tool, ultrasound (US) has been incorporated into the curriculum of medical schools for more than 20 years. In the last decade, the interest in US educational research has experienced exponential growth but mostly from Medical Doctor (MD)-granted schools. The extent to which US is embedded in the curricula of the colleges of osteopathic medicine (COM) still requires a comprehensive evaluation. OBJECTIVES: This survey is designed to evaluate the current status of US teaching in COMs with an emphasis on the inclusion of the US in osteopathic manipulative medicine (OMM) training. METHODS: An anonymous, voluntary, 22-question online survey was created and administered to all COMs to collect data about the current state of US teaching. A descriptive analysis was performed to describe and summarize the final data. Fisher's exact test was utilized for the comparison of study variables. RESULTS: We received responses from 36 of the 43 (83.7 %) COMs invited to participate in the survey, all of which had US training within their curriculum, most commonly integrated into the year 1 curriculum (86.1 %). Focused US training is incorporated into 83.3 % of these schools (30 of 36). Focused US training is covered in 83.3 % of schools (30 of 36). US is mostly taught in the anatomy course (38.8 %). US is incorporated in the OMM course in 12 of 36 schools (33.3 %). The majority of respondents feel that US training will make osteopathic students more competitive in the job market (88.9 %) and want more US in their curriculum (86.1 %). The idea that US is useful for a better understanding of the key OMM concepts is believed by 62.9 % of respondents. The major obstacle to the implementation of US in the curriculum is having appropriately trained faculty (86.1 %). The majority of the respondents did not feel that an adequate budget is a handicap to implementing US in the curriculum. CONCLUSIONS: US is included within the curriculum of all respondents to our survey, a third of whom included US within their OMM curriculum. US is treated as a useful and important skill for future osteopathic physicians. The majority of COMs desire more US training in the curriculum. The main barrier to implementing US in the curriculum is the lack of appropriately trained faculty.

Mesna Improves Outcomes of Sulfur Mustard Inhalation Toxicity in an Acute Rat Model.

Inhalation of high levels of sulfur mustard (SM), a potent vesicating and alkylating agent used in chemical warfare, results in acutely lethal pulmonary damage. Sodium 2-mercaptoethane sulfonate (mesna) is an organosulfur compound that is currently Food and Drug Administration (FDA)-approved for decreasing the toxicity of mustard-derived chemotherapeutic alkylating agents like ifosfamide and cyclophosphamide. The nucleophilic thiol of mesna is a suitable reactant for the neutralization of the electrophilic group of toxic mustard intermediates. In a rat model of SM inhalation, treatment with mesna (three doses: 300 mg/kg intraperitoneally 20 minutes, 4 hours, and 8 hours postexposure) afforded 74% survival at 48 hours, compared with 0% survival at less than 17 hours in the untreated and vehicle-treated control groups. Protection from cardiopulmonary failure by mesna was demonstrated by improved peripheral oxygen saturation and increased heart rate through 48 hours. Additionally, mesna normalized arterial pH and pACO2 Airway fibrin cast formation was decreased by more than 66% in the mesna-treated group at 9 hour after exposure compared with the vehicle group. Finally, analysis of mixtures of a mustard agent and mesna by a 5,5'-dithiobis(2-nitrobenzoic acid) assay and high performance liquid chromatography tandem mass spectrometry demonstrate a direct reaction between the compounds. This study provides evidence that mesna is an efficacious, inexpensive, FDA-approved candidate antidote for SM exposure. SIGNIFICANCE STATEMENT: Despite the use of sulfur mustard (SM) as a chemical weapon for over 100 years, an ideal drug candidate for treatment after real-world exposure situations has not yet been identified. Utilizing a uniformly lethal animal model, the results of the present study demonstrate that sodium 2-mercaptoethane sulfonate is a promising candidate for repurposing as an antidote, decreasing airway obstruction and improving pulmonary gas exchange, tissue oxygen delivery, and survival following high level SM inhalation exposure, and warrants further consideration.

Thiol-Disulfide Exchange Kinetics and Redox Potential of the Coenzyme M and Coenzyme B Heterodisulfide, an Electron Acceptor Coupled to Energy Conservation in Methanogenic Archaea.

Methanogenic and methanotrophic archaea play important roles in the global carbon cycle by interconverting CO2 and methane. To conserve energy from these metabolic pathways that happen close to the thermodynamic equilibrium, specific electron carriers have evolved to balance the redox potentials between key steps. Reduced ferredoxins required to activate CO2 are provided by energetical coupling to the reduction of the high-potential heterodisulfide (HDS) of coenzyme M (2-mercaptoethanesulfonate) and coenzyme B (7-mercaptoheptanoylthreonine phosphate). While the standard redox potential of this important HDS has been determined previously to be -143 mV (Tietze et al. 2003 DOI: 10.1002/cbic.200390053), we have measured thiol disulfide exchange kinetics and reassessed this value by equilibrating thiol-disulfide mixtures of coenzyme M, coenzyme B, and mercaptoethanol. We determined the redox potential of the HDS of coenzyme M and coenzyme B to be -16.4±1.7 mV relative to the reference thiol mercaptoethanol (E0 '=-264 mV). The resulting E0 ' values are -281 mV for the HDS, -271 mV for the homodisulfide of coenzyme M, and -270 mV for the homodisulfide of coenzyme B. We discuss the importance of these updated values for the physiology of methanogenic and methanotrophic archaea and their implications in terms of energy conservation.

A novel mesna-based electrochemical sensor embellished with silver nanoparticles for ultrasensitive analysis of modafinil.

Modafinil (MOD) is a CNS stimulant used for the treatment of narcolepsy, shift work sleep disorder, excessive daytime sleepiness, and post-COVID 19 neurological symptoms. In the literature, there is no report of square wave voltammetric (SWV) methods being used for the determination of MOD. This study describes, for the first time, the construction and evaluation of the analytical performance of a novel sensor for ultrasensitive SWV detection of MOD. The sensor was constructed by integration of silver nanoparticles (AgNPs) on Mesna (MSN) layers over a pencil graphite electrode (PGE) surface. The interface and morphological characteristics of the fabricated AgNPs@MSN/PGE sensor were investigated via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). This sensor was found to enhance the electro-oxidation of MOD. The combination of AgNPs@MSN/PGE with SWV enabled the determination of MOD in its bulk form and in pharmaceutical and biological matrices at the nanomolar scale (LOD = 28.59 nM) with excellent recoveries. This study represents the first report describing an electrochemical procedure for MOD detection in human plasma. The established SWV method was also validated, and the results were consistent with ICH criteria. Finally, the presented SWV procedure provides a facile, sensitive, rapid, and cost-effective approach compared to other existing methods.

MESNA (2-Mercaptoethanesulfonate) Attenuates Brain, Heart, and Lung Injury Induced by Carotid Ischemia-Reperfusion in Rats.

Background: Ischemia-reperfusion (I/R) causes organ dysfunction as a result of the increased formation of various reactive oxygen metabolites, infiltration of inflammatory cells, interstitial edema, cellular dysfunction, and tissue death. Aim: The study aimed to investigate the cytoprotective effect of 2-mercaptoethanesulfonate (MESNA) against tissue damage in rats exposed to carotid ischemia-reperfusion. Materials and Methods: Twenty-four male Wistar albino rats were divided into four groups (n = 6): sham, carotid I/R, I/R + MESNA (75 mg/kg), and I/R + MESNA (150 mg/kg) groups. To induce ischemia in rats, the carotid arteries were ligated with silk sutures for 10 min; the silk suture was then opened, and 1 h reperfusion was done. MESNA (75 and 150 mg/kg) was administered intraperitoneally 30 min before ischemia-reperfusion. Tissue samples from the animals were taken for histological examination, while the serum levels of some biochemical parameters were utilized to evaluate the systemic alterations. ANOVA and Tukey's post hoc tests were applied with a significance level of 5%. Results: The ischemia-reperfusion-induced tissue damage as evidenced by increase in serum levels of alanine transaminase, aspartate aminotransferase, alkaline phosphatase, malondialdehyde, lactate dehydrogenase, and matrix metalloproteinases (MMP-1, -2, -8) was significantly (P < 0.05-0.0001) reversed after treatment with MESNA in a dose-dependent manner. Treatment with MESNA (75 and 150 mg/kg), significantly (P < 0.05-0.0001) decreased the I/R-induced increase in serum tumor necrosis factor-alpha (TNF-α) and Interleukin-1-beta (IL-1 ß). Conclusion: The results of this study suggest that MESNA has a protective effect on tissues by suppressing cellular responses to oxidants and inflammatory mediators associated with carotid ischemia-reperfusion.

Cysteine-lowering treatment with mesna against obesity: Proof of concept and results from a human phase I, dose-finding study.

AIM: To investigate whether mesna-sodium-2-mercaptoethane sulfonate) can reduce diet-induced fat gain in mice, and to assess the safety of single ascending mesna doses in humans to find the dose associated with lowering of plasma tCys by at least 30%. METHODS: C3H/HeH mice were shifted to a high-fat diet ± mesna in drinking water; body composition was measured at weeks 0, 2 and 4. In an open, phase I, single ascending dose study, oral mesna (400, 800, 1200, 1600 mg) was administered to 17 men with overweight or obesity. Mesna and tCys concentrations were measured repeatedly for a duration of 48 hours postdosing in plasma, as well as in 24-hour urine. RESULTS: Compared with controls, mesna-treated mice had lower tCys and lower estimated mean fat mass gain from baseline (week 2: 4.54 ± 0.40 vs. 6.52 ± 0.36 g; week 4: 6.95 ± 0.35 vs. 8.19 ± 0.34 g; Poverall = .002), but similar lean mass gain. In men with overweight, mesna doses of 400-1600 mg showed dose linearity and were well tolerated. Mesna doses of 800 mg or higher decreased plasma tCys by 30% or more at nadir (4h post-dosing). With increasing mesna dose, tCys AUC0-12h decreased (Ptrend < .001), and urine tCys excretion increased (Ptrend = .004). CONCLUSIONS: Mesna reduces diet-induced fat gain in mice. In men with overweight, single oral doses of mesna (800-1600 mg) were well tolerated and lowered plasma tCys efficiently. The effect of sustained tCys-lowering by repeated mesna administration on weight loss in humans deserves investigation.

Fabrication of impedimetric sensor based on metallic nanoparticle for the determination of mesna anticancer drug.

Electrochemical impedance spectroscopy (EIS) is a highly effective technique for studying the surface of electrodes in great detail. EIS-based electrochemical sensors have been widely reported, which measure the charge transfer resistance (Rct) of redox probes on electrode surfaces to monitor the binding of target molecules. One of the protective drugs against hemorrhagic cystitis caused by oxazaphosphorine chemotherapy drugs such as ifosfamide, cyclophosphamide and trophosphamide is Mesna (sodium salt of 2-mercaptoethanesulfonate). The increase in the use of Mesna due to the high consumption of anti-cancer drugs, the determination of this drug in biological samples is of particular importance. So far, no electrochemical method has been reported to measure Mesna. In this research, a novel impedimetric sensor based on a glassy carbon electrode (GCE) modified with oxidized multiwalled carbon nanotubes (MWCNTs)/gold nanoparticle (AuNPs) (denoted as Au NPs/MWCNTs/GCE) for impedimetric determination of Mesna anticancer drug was developed. The modified electrode materials were characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), and EIS. The electrochemical behavior of Mesna at the surface of Au NPs/MWCNTs/GCE was studied by an impedimetric method. The detection mechanism of Mesna using the proposed impedimetric sensor relied on the increase in the Rct value of [Fe (CN)6]3-/4- as an electrochemical probe in the presence of Mesna compared to the absence of Mesna as the analyte. Under the optimum condition, which covered two linear dynamic ranges from 0.06 nmol L-1 to 1.0 nmol L-1 and 1.0 nmol L-1 to 130.0 µmol L-1, respectively. The detection limit was 0.02 nmol L-1. Finally, the performance of the proposed sensor was investigated for Mesna electrochemical detection in biological samples.

Alkyl Thiocyanurates as Thioester Mimetics. Transthioesterification and Ligation Reactions with High Potential in Dynamic Covalent Chemistry.

Alkyl thiocyanurates, the compounds formed in the SN reaction of thiocyanuric acid and alkyl halides, are susceptible to transthioesterification and ligation with molecules containing cysteamine, analogous to native chemical ligation of thioesters with peptides with an N-terminal cysteine moiety. The ligation is irreversible and results in the formation of mono- and disubstituted products dominantly. Transthioesterification, in contrast, is fully reversible and may be used in constructing dynamic systems. The application of this reactivity in dynamic covalent chemistry has been exemplified by the preparation of a library of mixed thiocyanurates of glutathione and thioglycolic acid with self-assembly abilities and metathesis between thiocyanurates of tris(carboxymethyl) and tris(carboxamidomethyl) catalyzed by MESNa (sodium 2-mercaptoethylsulphonate) or MPAA (4-mercaptophenylacetic acid). Differences in reactivity of thiocyanurates toward cysteamines and thiols has been explained based on conceptual DFT.

Brevetoxin induces a shift in the redox state of the proteome and unfolded protein response in human lymphoblast cells that can be alleviated with the acrolein scavenger MESNA.

Human lymphoblast cells were treated with the marine algal toxin, brevetoxin-2 (PbTx-2), and its effects on the proteome were assessed by redox proteomics using cysteine reactive tandem mass tags (TMT). Additionally, cells were simultaneously treated with PbTx-2 and the antioxidant and acrolein scavenger sodium 2-mercaptoethylsulfonate (MESNA) to determine if MESNA could prevent the proteomic effects of brevetoxin-2. A massive shift in the redox state of the proteome of brevetoxin-2 treated cells was observed. The main pathway affected was genetic information processing. Significantly oxidized proteins included Trx-1, peroxyredoxins (Prxs), ribosomal proteins, and the eukaryotic initiation factor 2 ß subunit (eIF2ß). Proteins that were overexpressed in brevetoxin-treated cells included four folding chaperones. These effects were diminished in the presence of MESNA indicating that MESNA may act through its antioxidant properties or as a brevetoxin scavenger. These studies provide novel insights into new prophylactics for brevetoxicosis in humans and wildlife.

[Analysis of the prevalence and social security situation of pneumoconiosis in non-coal mine industry in Jiangsu Province].

Objective: To understand the social security situation of current cases of pneumoconiosis in non-coal mine industries in Jiangsu Province, and to provide reference for the treatment and security work of pneumoconiosis patients. Methods: From January to October 2020, a follow-up survey was conducted on 4038 cases of pneumoconiosis in non-coal mine industries of the province from October 1949 to December 2019. The age, type of pneumoconiosis, industry type, and social security status of the patients were collected. Namely, work-related injury insurance, employer compensation, basic medical insurance for urban and rural residents, major illness insurance, etc. SPSS 19.0 was used for statistical description and analysis. Results: The cases of pneumoconiosis in non-coal mine industries in Jiangsu Province ranged in age from 36 to 105 (70.78±8.43) years old, and had been exposed to dust for 1 to 55 (19.27±9.29) years. Silicosis was the main form (3875 cases, 95.96%), and non-metallic mining and dressing industry was the main form (2618 cases, 64.83%). A total of 3991 cases (98.84%) of pneumoconiosis patients enjoyed social security, most of them were urban and rural residents with basic medical insurance (3624 cases, 89.75%), but there were still 47 patients without any social security. 15 cases (0.37%) enjoyed the subsistence allowance, with the monthly allowance amount ranging from 104 to 3960 yuan, with the average amount of 954.87 yuan/month. Conclusion: In Jiangsu Province, the proportion of pneumoconiosis patients in non-coal mine industries enjoying social security is relatively high, but there are still patients who do not enjoy any social security, and the difference in the amount of subsistence allowance is slightly larger. It is necessary to further improve the medical security of pneumoconiosis patients and improve their quality of life.

[8] and [10]-Gingerol reduces urothelial damage in ifosfamide-induced hemorrhagic cystitis via JAK/STAT/FOXO signaling pathway via IL-10.

Acrolein is the main toxic metabolite of ifosfamide (IFO) that causes urothelial damage by oxidative stress and inflammation. Here, we investigate the molecular mechanism of action of gingerols, Zingiber officinale bioactive molecules, as an alternative treatment for ifosfamide-induced hemorrhagic cystitis. Female Swiss mice were randomly divided into 5 groups: control; IFO; IFO + Mesna; and IFO + [8]- or [10]-gingerol. Mesna (80 mg/kg, i.p.) was given 5 min before, 4 and 8 h after IFO (400mg/kg, i.p.). Gingerols (25 mg/kg, p.o.) were given 1 h before and 4 and 8 h after IFO. Animals were euthanized 12 h after IFO injection. Bladders were submitted to macroscopic and histological evaluation. Oxidative stress and inflammation were assessed by malondialdehyde (MDA) or myeloperoxidase assays, respectively. mRNA gene expression was performed to evaluate mesna and gingerols mechanisms of action. Mesna was able to protect bladder tissue by activating NF-κB and NrF2 pathways. However, we demonstrated that gingerols acted as an antioxidant and anti-inflammatory agent stimulating the expression of IL-10, which intracellularly activates JAK/STAT/FOXO signaling pathway.

High-dose continuous-infusion ifosfamide in advanced thymic epithelial Tumors: A TYME network study.

BACKGROUND: We reported the efficacy and safety results of high-dose, continuous-infusion Ifosfamide,in patients with advanced thymoma (TM) and thymic carcinoma (TC). METHODS: This was a multicentric, prospective study in patients with advanced TM or TC, who had progressed after at least one line of platinum-based chemotherapy. Previous treatment with an anti-angiogenesis or anti-PD(L)1 was allowed. Patients received Ifosfamide (1 g/m2/day) and sodium-2-mercaptoethanesulfonate (1 g/m2/day), as continuous infusion, via a portable pumps for 14 consecutive days. Treatment was administered every 4 weeks until progression or unacceptable toxicity, up to a maximum of 6 cycles. The primary endpoint was the overall response rate (ORR) assessed by RECIST1.1. Secondary endpoints included disease control rate (DCR), Progression-free survival (PFS), overall survival (OS), and safety. RESULTS: Eighteen patients were enrolled from October 2020 to January 2022. Twelve patients had a TC, 5 a TM and 1 a mixed TM/TC. Sixty-one percent of patients (11/18) had stage IVB disease according to Masaoka-Koga, and 39% (7/18) had an ECOG-PS 2. The median number of previous lines of therapy was 2 (range:1-5), and 72% (13/18) and 61% (11/18) of patients were pretreated with an anti-angiogenesis drug and an anti-PD(L)1 drug respectively. The ORR and the disease control rate (DCR) were 28 % (95 %CI: 10 %-53 %) and 67 % (95 %CI: 41 %-86 %), respectively. The median follow-up for PFS was 17.3 months (95 %CI: 4.3-NA), and median PFS was 5.4 months (95 %CI: 2.9-6.4). The median duration of response and SD was respectively 19.6 months (95 %CI: 3.5-NA) and 6.0 months (95 % CI: 3.8-6.4). In patients with TC, the ORR and DCR were 15 % (95 % CI: 2 %-45 %) and 54 % (95 % CI: 25 %-81 %), respectively. In the subgroup of 5 patients with TM, 2 PR and 3 SD were observed. Most patients had only mild (grade 1-2) AEs, the most common being nausea and vomiting (39%; 7/18) and transaminases elevation (33%; 6/18). Twenty-two percent of patients (4/18) experienced an AEs of grade 3 and required ifosfamide dose reduction. No patients had severe AEs. CONCLUSION: High-dose continuous-infusion Ifosfamide can be considered as a valuable treatment option in patients with advanced thymic epithelial tumors.

Evaluation of the Efficacy of Lactobacillus acidophilus in the Treatment of Cyclophosphamide-induced Hemorrhagic Cystitis in Wistar Rats.

BACKGROUND: Hemorrhagic cystitis is an inflammatory complication that can be caused by the administration of cyclophosphamide, which is widely used as an antineoplastic agent. In the search for new therapeutic alternatives, probiotics can suppress the inflammatory process and, therefore, can be used to prevent this disease. OBJECTIVE: Thus, this study aimed to evaluate the effects of using Lactobacillus acidophilus NCFM in the treatment of cyclophosphamide-induced hemorrhagic cystitis in Wistar rats. METHODS: Lactobacillus acidophilus NCFM (2x108 CFU) was used in the treatment of cyclophosphamide- induced hemorrhagic cystitis (200 mg/kg, intraperitoneal) in 77 female Wistar rats. Rats were distributed into experimental groups (n = 9): control group (GC), zero control group (GCZ), inflammation group (GI), 24-hour acute treatment groups: 24-hour lactobacilli treatment group (GL24H) and mesna group (GM), and 30-day chronic treatment groups: lactobacilli treatment group (GTL) and mesna+lactobacilli group (GM+L). After treatment, animals were euthanized and biological materials were collected for blood count, biochemical analyses, examination of abnormal sediment elements (EAS), and histopathological analysis. RESULTS: GI results showed development of edema, macroscopic alterations, and signs of bleeding in the bladder; in addition, lesions in the urothelium and hemorrhage were also found. GL24H and GM presented intact urothelium, without inflammatory reaction and hematological or biochemical urine alterations. CONCLUSION: Therefore, this study demonstrated that L. acidophilus presented uroprotective effect against the action of cyclophosphamide in both the short and long term.

Analysis of the prevalence and social security situation of pneumoconiosis in non-coal mine industry in Jiangsu Province / 中华劳动卫生职业病杂志

Objective: To understand the social security situation of current cases of pneumoconiosis in non-coal mine industries in Jiangsu Province, and to provide reference for the treatment and security work of pneumoconiosis patients. Methods: From January to October 2020, a follow-up survey was conducted on 4038 cases of pneumoconiosis in non-coal mine industries of the province from October 1949 to December 2019. The age, type of pneumoconiosis, industry type, and social security status of the patients were collected. Namely, work-related injury insurance, employer compensation, basic medical insurance for urban and rural residents, major illness insurance, etc. SPSS 19.0 was used for statistical description and analysis. Results: The cases of pneumoconiosis in non-coal mine industries in Jiangsu Province ranged in age from 36 to 105 (70.78±8.43) years old, and had been exposed to dust for 1 to 55 (19.27±9.29) years. Silicosis was the main form (3875 cases, 95.96%), and non-metallic mining and dressing industry was the main form (2618 cases, 64.83%). A total of 3991 cases (98.84%) of pneumoconiosis patients enjoyed social security, most of them were urban and rural residents with basic medical insurance (3624 cases, 89.75%), but there were still 47 patients without any social security. 15 cases (0.37%) enjoyed the subsistence allowance, with the monthly allowance amount ranging from 104 to 3960 yuan, with the average amount of 954.87 yuan/month. Conclusion: In Jiangsu Province, the proportion of pneumoconiosis patients in non-coal mine industries enjoying social security is relatively high, but there are still patients who do not enjoy any social security, and the difference in the amount of subsistence allowance is slightly larger. It is necessary to further improve the medical security of pneumoconiosis patients and improve their quality of life.

Expression of divergent methyl/alkyl coenzyme M reductases from uncultured archaea.

Methanogens and anaerobic methane-oxidizing archaea (ANME) are important players in the global carbon cycle. Methyl-coenzyme M reductase (MCR) is a key enzyme in methane metabolism, catalyzing the last step in methanogenesis and the first step in anaerobic methane oxidation. Divergent mcr and mcr-like genes have recently been identified in uncultured archaeal lineages. However, the assembly and biochemistry of MCRs from uncultured archaea remain largely unknown. Here we present an approach to study MCRs from uncultured archaea by heterologous expression in a methanogen, Methanococcus maripaludis. Promoter, operon structure, and temperature were important determinants for MCR production. Both recombinant methanococcal and ANME-2 MCR assembled with the host MCR forming hybrid complexes, whereas tested ANME-1 MCR and ethyl-coenzyme M reductase only formed homogenous complexes. Together with structural modeling, this suggests that ANME-2 and methanogen MCRs are structurally similar and their reaction directions are likely regulated by thermodynamics rather than intrinsic structural differences.

Extrato de Echinodorus grandiflorus apresenta efeito renoprotetor em ratos com nefrotoxicidade aguda induzida pela ciclofosfamida / Extract of Echinodorus grandiflorus presents renoprotetic effect on rats with acute nephrotoxicity induced by cyclophosphamid / El extracto de Echinodorus grandiflorus tiene un efecto renoprotector en ratas con nefrotoxicidad aguda inducida por ciclofosfamida

Pelas características anatômicas e fisiológicas dos rins, a lesão renal aguda tem sua origem nefrotóxica pela alta circulação local, o que favorece a alta concentração de substâncias tóxicas e seus metabólitos no tecido. A lesão renal aguda é uma complicação comum em internações hospitalares e principalmente em internações em unidades de terapia intensiva. A ciclofosfamida, um quimioterápico utilizado no tratamento de doenças autoimunes e neoplasias sólidas, pode causar nefrotoxicidade com disfunção glomerular e tubular. O uso de plantas medicinais, pelas suas potentes ações antioxidantes, tem sido usado para prevenção ou tratamento de lesões celulares induzidas pelo desequilíbrio entre enzimas antioxidantes e oxidantes. Por esse motivo, o objetivo do experimento foi avaliar o potencial efeito protetor da Echinodorus grandiflorus na prevenção da nefrotoxidade induzida pela ciclofosfamida. Para isso, foi realizado o experimento com a utilização de 35 ratos machos, Wistar, divididos em seis grupos experimentais, sendo administrado a ciclofosfamida na dose de 150mg/kg nos grupos G2 a G6 e diferentes doses da Echinodorus grandiflorus, com posterior análise de parâmetros sanguíneos e histológicos. A administração de ciclofosfamida na dose de 150mg/kg de massa corporal, em dose única, foi capaz de induzir a nefrotoxicidade aguda em todos os ratos. O extrato bruto de Echinodorus grandiflorus apresentou potencial efeito renoprotetor ao uso da ciclofosfamida, na dose de 300mg/kg de massa corporal, sendo possível observar redução dos efeitos nefrotóxicos do quimioterápico, pela redução dos danos tubulares e pela diminuição dos espaços capsulas, nitidamente encontradas alterados no grupo que recebeu apenas ciclofosfamida, denotando resultados promissores para utilização desta planta medicinal na prevenção da nefrotoxicidade induzida pelo fármaco. Contudo, novos estudos dos efeitos renoprotetor do chapéu de couro, poderão elucidar os mecanismos envolvidos na ação do extrato bruto do chapéu de couro. A utilização de extrato bruto de plantas medicinais torna-se um adjuvante aos tratamentos pelo baixo custo e pela facilidade de acesso das diferentes populações as plantas desde que devidamente orientados pelos profissionais habilitados.

Due to the anatomical and physiological characteristics of the kidneys, acute kidney injury has its nephrotoxic origin due to the high local circulation, which favors the high concentration of toxic substances and their metabolites in the tissue. Acute kidney injury is a common complication in hospital admissions and especially in intensive care unit admissions. Cyclophosphamide, a chemotherapy drug used in the treatment of autoimmune diseases and solid neoplasms, can cause nephrotoxicity with glomerular and tubular dysfunction. The use of medicinal plants, due to their potent antioxidant actions, has been used for the prevention or treatment of cellular injuries induced by the imbalance between antioxidant and oxidant enzymes. For this reason, the aim of the experiment was to evaluate the potential protective effect of Echinodorus grandiflorus in preventing cyclophosphamide-induced nephrotoxicity. For this, the experiment was carried out with the use of 35 male Wistar rats, divided into six experimental groups, being administered cyclophosphamide at a dose of 150mg/kg in groups G2 to G6 and different doses of Echinodorus grandiflorus, with subsequent analysis of parameters blood and histology. The administration of cyclophosphamide at a dose of 150mg/kg of body weight, in a single dose, was able to induce acute nephrotoxicity in all rats. The crude extract of Echinodorus grandiflorus showed a potential renoprotective effect with the use of cyclophosphamide, at a dose of 300mg/kg of body mass, and it was possible to observe a reduction in the nephrotoxic effects of the chemotherapy, due to the reduction of tubular damage and the reduction of capsule spaces, clearly found altered in the group that received only cyclophosphamide, showing promising results for the use of this medicinal plant in the prevention of drug-induced nephrotoxicity. However, further studies of the renoprotective effects of the leather hat may elucidate the mechanisms involved in the action of the crude extract of the leather hat. The use of raw extract of medicinal plants becomes an adjuvant to treatments due to the low cost and ease of access of different populations to plants, provided that they are properly guided by qualified professionals.

Debido a las características anatómicas y fisiológicas de los riñones, la lesión renal aguda tiene su origen nefrotóxico por la elevada circulación local, que favorece la alta concentración de sustancias tóxicas y sus metabolitos en el tejido. La lesión renal aguda es una complicación frecuente en los ingresos hospitalarios y principalmente en las unidades de cuidados intensivos. La ciclofosfamida, un quimioterápico utilizado en el tratamiento de enfermedades autoinmunes y neoplasias sólidas, puede causar nefrotoxicidad con disfunción glomerular y tubular. El uso de plantas medicinales, debido a sus potentes acciones antioxidantes, se ha utilizado para la prevención o el tratamiento de lesiones celulares inducidas por el desequilibrio entre enzimas antioxidantes y oxidantes. Por este motivo, el objetivo del experimento era evaluar el posible efecto protector del Echinodorus grandiflorus en la prevención de la nefrotoxicidad inducida por la ciclofosfamida. Para ello, se realizó el experimento utilizando 35 ratas Wistar macho, divididas en seis grupos experimentales, administrándoseles ciclofosfamida a una dosis de 150mg/kg en los grupos G2 a G6 y diferentes dosis de Echinodorus grandiflorus, con posterior análisis de sangre y parámetros histológicos. La administración de ciclofosfamida a una dosis de 150mg/kg de masa corporal, en dosis única, fue capaz de inducir nefrotoxicidad aguda en todas las ratas. El extracto crudo de Echinodorus grandiflorus presentó un potencial efecto renoprotector al uso de ciclofosfamida, a una dosis de 300mg/kg de masa corporal, siendo posible observar una reducción de los efectos nefrotóxicos de la quimioterapia, por la reducción del daño tubular y por la disminución de los espacios capsulares, encontrándose claramente alterados en el grupo que recibió solamente ciclofosfamida, denotando resultados promisorios para el uso de esta planta medicinal en la prevención de la nefrotoxicidad inducida por el fármaco. Sin embargo, nuevos estudios sobre los efectos renoprotectores del sombrero de cuero podrían dilucidar los mecanismos implicados en la acción del extracto crudo de sombrero de cuero. El uso de extractos crudos de plantas medicinales se convierte en un coadyuvante de los tratamientos por su bajo coste y la facilidad de acceso de las diferentes poblaciones a las plantas desde que son guiadas adecuadamente por profesionales cualificados.

Updates in paediatric cholesteatoma.

PURPOSE OF REVIEW: The management of paediatric patients with cholesteatoma is complex, as the disease process is more aggressive in children than adults. New technologies and practice adaptations currently help optimize the surgical management and monitoring of these challenging patients. RECENT FINDINGS: Several options of surgical management are available and are associated with equal if not improved outcomes. Technologic advancements in endoscopic ear surgery, the discovery of chemical-assisted dissection of cholesteatoma and advanced imaging protocols have enabled surgeons to better care for patients with this complex disease process. SUMMARY: The advances in endoscopic ear surgery, the discovery of Mesna as a chemically assisted dissection agent to improve recidivism rates and the use of specific diffusion-weighted MRI protocols enable the otologic surgeon to better care for these paediatric patients.

The pathway for coenzyme M biosynthesis in bacteria.

Mercaptoethane sulfonate or coenzyme M (CoM) is the smallest known organic cofactor and is most commonly associated with the methane-forming step in all methanogenic archaea but is also associated with the anaerobic oxidation of methane to CO2 in anaerobic methanotrophic archaea and the oxidation of short-chain alkanes in Syntrophoarchaeum species. It has also been found in a small number of bacteria capable of the metabolism of small organics. Although many of the steps for CoM biosynthesis in methanogenic archaea have been elucidated, a complete pathway for the biosynthesis of CoM in archaea or bacteria has not been reported. Here, we present the complete CoM biosynthesis pathway in bacteria, revealing distinct chemical steps relative to CoM biosynthesis in methanogenic archaea. The existence of different pathways represents a profound instance of convergent evolution. The five-step pathway involves the addition of sulfite, the elimination of phosphate, decarboxylation, thiolation, and the reduction to affect the sequential conversion of phosphoenolpyruvate to CoM. The salient features of the pathway demonstrate reactivities for members of large aspartase/fumarase and pyridoxal 5'-phosphate-dependent enzyme families.