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1.
Huan Jing Ke Xue ; 45(5): 3088-3097, 2024 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-38629569

RESUMO

Mulching to conserve moisture has become an important agronomic practice in saline soil cultivation, and the effects of the dual stress of salinity and microplastics on soil microbes are receiving increasing attention. In order to investigate the effect of polyethylene microplastics on the microbial community of salinized soils, this study investigated the effects of different types (chloride and sulphate) and concentrations (weak, medium, and strong) of polyethylene (PE) microplastics (1% and 4% of the dry weight mass of the soil sample) on the soil microbial community by simulating microplastic contamination in salinized soil environments indoors. The results showed that:PE microplastics reduced the diversity and abundance of microbial communities in salinized soils and were more strongly affected by sulphate saline soil treatments. The relative abundance of each group of bacteria was more strongly changed in the sulphate saline soil treatment than in the chloride saline soil treatment. At the phylum level, the relative abundance of Proteobacteria was positively correlated with the abundance of fugitive PE microplastics, whereas the relative abundances of Bacteroidota, Actinobacteriota, and Acidobacteria were negatively correlated with the abundance of fugitive PE microplastics. At the family level, the relative abundances of Flavobacteriaceae, Alcanivoracaceae, Halomonadaceae, and Sphingomonasceae increased with increasing abundance of PE microplastics. The KEGG metabolic pathway prediction showed that the relative abundance of microbial metabolism and genetic information functions were reduced by the presence of PE microplastics, and the inhibition of metabolic functions was stronger in sulphate saline soils than in chloride saline soils, whereas the inhibition of genetic information functions was weaker than that in chloride saline soils. The secondary metabolic pathways of amino acid metabolism, carbohydrate metabolism, and energy metabolism were inhibited. It was hypothesized that the reduction in metabolic functions may have been caused by the reduced relative abundance of the above-mentioned secondary metabolic pathways. This study may provide a theoretical basis for the study of the effects of microplastics and salinization on the soil environment under the dual pollution conditions.


Assuntos
Microplásticos , Polietileno , Plásticos , Solo , Cloretos , Halogênios , Sulfatos , Microbiologia do Solo
2.
Proc Natl Acad Sci U S A ; 121(15): e2322135121, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38568964

RESUMO

Endothelial cells (ECs) line the wall of blood vessels and regulate arterial contractility to tune regional organ blood flow and systemic pressure. Chloride (Cl-) is the most abundant anion in ECs and the Cl- sensitive With-No-Lysine (WNK) kinase is expressed in this cell type. Whether intracellular Cl- signaling and WNK kinase regulate EC function to alter arterial contractility is unclear. Here, we tested the hypothesis that intracellular Cl- signaling in ECs regulates arterial contractility and examined the signaling mechanisms involved, including the participation of WNK kinase. Our data obtained using two-photon microscopy and cell-specific inducible knockout mice indicated that acetylcholine, a prototypical vasodilator, stimulated a rapid reduction in intracellular Cl- concentration ([Cl-]i) due to the activation of TMEM16A, a Cl- channel, in ECs of resistance-size arteries. TMEM16A channel-mediated Cl- signaling activated WNK kinase, which phosphorylated its substrate proteins SPAK and OSR1 in ECs. OSR1 potentiated transient receptor potential vanilloid 4 (TRPV4) currents in a kinase-dependent manner and required a conserved binding motif located in the channel C terminus. Intracellular Ca2+ signaling was measured in four dimensions in ECs using a high-speed lightsheet microscope. WNK kinase-dependent activation of TRPV4 channels increased local intracellular Ca2+ signaling in ECs and produced vasodilation. In summary, we show that TMEM16A channel activation reduces [Cl-]i, which activates WNK kinase in ECs. WNK kinase phosphorylates OSR1 which then stimulates TRPV4 channels to produce vasodilation. Thus, TMEM16A channels regulate intracellular Cl- signaling and WNK kinase activity in ECs to control arterial contractility.


Assuntos
Cloretos , Proteínas Serina-Treonina Quinases , Camundongos , Animais , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Cloretos/metabolismo , Células Endoteliais/metabolismo , Canais de Cátion TRPV/metabolismo , Transdução de Sinais/fisiologia
3.
Int J Mol Sci ; 25(7)2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38612883

RESUMO

Osteoporosis stands out as a prevalent skeletal ailment, prompting exploration into potential treatments, including dietary strontium ion supplements. This study assessed the efficacy of supplementation of three strontium forms-strontium citrate (SrC), strontium ranelate (SrR), and strontium chloride (SrCl)-for enhancing bone structure in 50 female SWISS mice, aged seven weeks. In total, 40 mice underwent ovariectomy, while 10 underwent sham ovariectomy. Ovariectomized (OVX) mice were randomly assigned to the following groups: OVX (no supplementation), OVX + SrR, OVX + SrC, and OVX + SrCl, at concentrations equivalent to the molar amount of strontium. After 16 weeks, micro-CT examined trabeculae and cortical bones, and whole-bone strontium content was determined. Results confirm strontium administration increased bone tissue mineral density (TMD) and Sr content, with SrC exhibiting the weakest effect. Femur morphometry showed limited Sr impact, especially in the OVX + SrC group. This research highlights strontium's potential in bone health, emphasizing variations in efficacy among its forms.


Assuntos
Ácido Cítrico , Osteoporose , Estrôncio , Tiofenos , Feminino , Animais , Camundongos , Densidade Óssea , Cloretos , Citratos , Osteoporose/tratamento farmacológico , Halogênios , Modelos Animais de Doenças
4.
Anal Chem ; 96(15): 5832-5842, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38573917

RESUMO

Chronic kidney disease is one of the major health issues worldwide. However, diagnosis is now highly centralized in large laboratories, resulting in low access to patient monitoring and poor personalized treatments. This work reports the development of a graphene-based lab-on-a-chip (G-LOC) for the digital testing of renal function biomarkers in serum and saliva samples. G-LOC integrates multiple bioelectronic sensors with a microfluidic system that enables multiplex self-testing of urea, potassium, sodium, and chloride. The linearity, limit of detection (LOD), accuracy, and coefficient of variability (CV) were studied. Accuracy values higher than 95.5% and CV lower than 9% were obtained for all of the biomarkers. The analytical performance was compared against three reference lab benchtop analyzers by measuring healthy- and renal-failure-level samples of serum. From receiver operating characteristic (ROC) plots, sensitivities (%) of 99.7, 97.6, 99.1, and 89.0 were obtained for urea, potassium, sodium, and chloride, respectively. Then, the test was evaluated in noninvasive saliva samples and compared against reference methods. Correlation and Bland-Altman plots showed good correlation and agreement of the G-LOC with the reference methods. It is noteworthy that the precision of G-LOC was similar to better than benchtop lab analyzers, with the advantage of being highly portable. Finally, a user testing study was conducted. The analytical performance obtained with untrained volunteers was similar to that obtained with trained chemists. Additionally, based on a user experience survey, G-LOC was found to have very simple usability and would be suitable for at-home diagnostics.


Assuntos
Grafite , Nefropatias , Humanos , Cloretos , Autoteste , Dispositivos Lab-On-A-Chip , Rim , Nefropatias/diagnóstico , Biomarcadores , Ureia , Potássio , Sódio
5.
Chemosphere ; 355: 141855, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38570051

RESUMO

Wastewater polluted by organics can be treated by using electro-generated active chlorine, even if this promising route presents some important drawbacks such as the production of chlorinated by-products. Here, for the first time, this process was studied in a microfluidic electrochemical reactor with a very small inter-electrode distance (145 µm) using a water solution of NaCl and phenol and a BDD anode. The potential production of chloroacetic acids, chlorophenols, carboxylic acids, chlorate and perchlorate was carefully evaluated. It was shown, for the first time, up to our knowledge, that the use of the microfluidic device allows to perform the treatment under a continuous mode and to achieve higher current efficiencies and a lower generation of some important by-products such as chlorate and perchlorate. As an example, the use of the microfluidic apparatus equipped with an Ag cathode allowed to achieve a high removal of total organic carbon (about 76%) coupled with a current efficiency of 17% and the production of a small amount of chlorate (about 30 ppm) and no perchlorate. The effect of many parameters (namely, flow rate, current density and nature of cathode) was also investigated.


Assuntos
Cloro , Poluentes Químicos da Água , Técnicas Eletroquímicas , Percloratos , Microfluídica , Água , Cloratos , Cloretos , Oxirredução , Eletrodos , Poluentes Químicos da Água/análise
6.
Nan Fang Yi Ke Da Xue Xue Bao ; 44(3): 523-532, 2024 Mar 20.
Artigo em Chinês | MEDLINE | ID: mdl-38597444

RESUMO

OBJECTIVE: To investigate the effect of asiaticoside on blood pressure and relaxation of thoracic aorta in rats and explore the underlying mechanism. METHODS: SD rats treated with 50 and 100 mg/kg asiaticoside by daily gavage for 2 weeks were monitored for systolic blood pressure changes, and histological changes of the thoracic aorta were evaluated using HE staining. In isolated rat endothelium-intact and endothelium-denuded thoracic aorta rings, the effects of asiaticoside on relaxation of the aortic rings were tested at baseline and following norepinephrine (NE)- and KCl-induced constriction. The vascular relaxation effect of asiaticoside was further observed in NE-stimulated endothelium-intact rat aortic rings pretreated with L-nitroarginine methyl ester, indomethacin, zinc protoporphyrin Ⅸ, tetraethyl ammonium chloride, glibenclamide, barium chloride, Iberiotoxin, 4-aminopyridine, or TASK-1-IN-1. The aortic rings were treated with KCl and NE followed by increasing concentrations of CaCl2 to investigate the effect of asiaticoside on vasoconstriction induced by external calcium influx and internal calcium release. RESULTS: Asiaticoside at 50 and 100 mg/kg significantly lowered systolic blood pressure in rats without affecting the thoracic aorta histomorphology. While not obviously affecting resting aortic rings with intact endothelium, asiaticoside at 100 mg/kg induced significant relaxation of the rings constricted by KCl and NE, but its effects differed between endothelium-intact and endothelium-denuded rings. In endothelium-intact aortic rings pretreated with indomethacin, ZnPP Ⅸ, barium chloride, glyburide, TASK-1-IN-1 and 4-aminopyridine, asiaticoside did not produce significant effect on NE-induced vasoconstriction, and tetraethylammonium, Iberiotoxin and L-nitroarginine methyl ester all inhibited the relaxation effect of asiaticoside. In KCland NE-treated rings, asiaticoside obviously inhibited CaCl2-induced vascular contraction. CONCLUSION: Asiaticoside induces thoracic aorta relaxation by mediating high-conductance calcium-activated potassium channel opening, promoting nitric oxide release from endothelial cells and regulating Ca2+ influx and outflow, thereby reducing systolic blood pressure in rats.


Assuntos
Aorta Torácica , Compostos de Bário , Cloretos , Triterpenos , Vasodilatação , Ratos , Animais , Pressão Sanguínea , Células Endoteliais , Cálcio , Cloreto de Cálcio/farmacologia , Nitroarginina/farmacologia , Ratos Sprague-Dawley , 4-Aminopiridina/farmacologia , Indometacina/farmacologia , Ésteres/farmacologia , Endotélio Vascular , Relação Dose-Resposta a Droga
7.
Environ Geochem Health ; 46(5): 158, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38592363

RESUMO

Groundwater, a predominant reservoir of freshwater, plays a critical role in providing a sustainable potable water and water for agricultural and industry uses in the In Salah desert region of Algeria. This research collected 82 underground water samples from Albian aquifers to assess water quality and identify hydrogeochemical processes influencing mineralization. To achieve this objective, various methods were employed to evaluate water quality based on its intended uses. The drinking water quality index utilized revealed the water potability status, while the indicators of irrigation potability were employed to evaluate its quality for agricultural purposes. Additionally, an assessment of groundwater susceptibility to corrosion and scaling in an industrial context was conducted using several indices, e.g., Langelier index, Larson-Skold index, Ryznar index, chloride-sulfate mass ratio, Puckorius index, aggressiveness index, and the Revelle index. The findings of this study revealed that the groundwater quality for consumption fell into four categories: good (2.44%), fair (29.27%), poor (65.85%), and non-potable (2.44%). Concerning agricultural irrigation, the indexical results indicated that 15.85% of the waters exhibited adequate quality, while 84.15% were questionable for irrigation. Calculations based on various corrosion and scaling evaluation indices showed that most wells were prone to corrosion, with a tendency for calcium bicarbonate deposit formation. Furthermore, the hydrochemical study identified three water types: Na-Cl (53.66%), Ca-Mg-Cl (37.80%), and Ca-Cl (8.54%) waters. Analyses of correlation matrices, R-type clustering, factor loadings, Gibbs diagrams, scatterplots, and chloro-alkaline indices highlighted that the chemistry of the Albian groundwater is fundamentally impacted by a number of processes such as silicate weathering, evaporite dissolution, ionic exchange, and anthropogenic inputs, that played impactful role in the aquifer's water chemistry.


Assuntos
Irrigação Agrícola , Água Subterrânea , África do Norte , Agricultura , Bicarbonatos , Cloretos
8.
Pan Afr Med J ; 47: 37, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38586073

RESUMO

Introduction: type 2 Diabetes mellitus is a chronic metabolic disease with devastating effects on patients and results in numerous healthcare challenges in terms of its management and the cost burden among the affected. Successful management involves maintaining optimal glycemic control to prevent complications, with adherence to antidiabetic medications playing a crucial role in achieving this objective. Additionally, maintaining a healthy electrolyte balance is key for overall well-being and physiological function. However, the correlation between glycated hemoglobin and electrolyte balance remains under investigated, particularly in patients with suboptimal adherence. The aim of this research was to study the relationship between glycated hemoglobin and electrolytes among diabetic patients with poor adherence to antidiabetic medications. Methods: this study was conducted at Samburu County Referral Hospital in Samburu County, Kenya. We employed a descriptive cross-sectional design focusing on adult diabetic patients aged 18 years and above who had visited the diabetic clinic over a three-month period. To evaluate their adherence levels, we employed a Morisky Medication Adherence Scale-8. Seventy-two diabetic patients who got adherence level scores of < 6 were categorized as having low adherence and their blood samples were collected for measuring glycated hemoglobin levels and electrolytes levels particularly potassium, sodium, calcium, magnesium, phosphorus and chloride. Relationship between electrolytes and glycated hemoglobin among diabetic patients with poor adherence to antidiabetics was determined using Karl Pearson correlation. Results: among the study participants, the lowest hemoglobin A1C (HbA1c) level recorded was 5.1% while the highest was 15.0% and the majority (41.7%) fell within the HbA1c range of 5-7%. A high proportion of individuals (58.3%) with poor adherence to antidiabetics had elevated HbA1c levels, indicating poor glycemic control. The correlations observed between glycated hemoglobin and electrolytes which included magnesium, sodium, chloride, calcium and phosphorus was r= -0.07, -0.32, -0.05 -0.24 and -0.04 respectively. Conclusion: this study concluded that there is a relationship between electrolytes and glycated hemoglobin among diabetic patients with poor adherence to antidiabetics. A statistically significant negative correlation was observed between glycated hemoglobin and calcium level (r=-0.2398 P ≤0.05) and also sodium (r=-0.31369 P≤0.05). A negative correlation (P≥0.05) was observed between phosphorus, magnesium, chloride and potassium with HbA1c levels though not statistically significant.


Assuntos
Diabetes Mellitus Tipo 2 , Adulto , Humanos , Hemoglobinas Glicadas , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Estudos Transversais , Cálcio , Magnésio , Cloretos/uso terapêutico , Glicemia/metabolismo , Hipoglicemiantes/uso terapêutico , Eletrólitos , Sódio , Potássio , Fósforo
9.
Appl Microbiol Biotechnol ; 108(1): 289, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38587649

RESUMO

Rumen microbial urease inhibitors have been proposed for regulating nitrogen emission and improving nitrogen utilization efficiency in ruminant livestock industry. However, studies on plant-derived natural inhibitors of rumen microbial urease are limited. Urease accessory protein UreG, plays a crucial role in facilitating urease maturation, is a new target for design of urease inhibitor. The objective of this study was to select the potential effective inhibitor of rumen microbial urease from major protoberberine alkaloids in Rhizoma Coptidis by targeting UreG. Our results showed that berberine chloride and epiberberine exerted superior inhibition potential than other alkaloids based on GTPase activity study of UreG. Berberine chloride inhibition of UreG was mixed type, while inhibition kinetics type of epiberberine was uncompetitive. Furthermore, epiberberine was found to be more effective than berberine chloride in inhibiting the combination of nickel towards UreG and inducing changes in the second structure of UreG. Molecular modeling provided the rational structural basis for the higher inhibition potential of epiberberine, amino acid residues in G1 motif and G3 motif of UreG formed interactions with D ring of berberine chloride, while interacted with A ring and D ring of epiberberine. We further demonstrated the efficacy of epiberberine in the ruminal microbial fermentation with low ammonia release and urea degradation. In conclusion, our study clearly indicates that epiberberine is a promising candidate as a safe and effective inhibitor of rumen microbial urease and provides an optimal strategy and suitable feed additive for regulating nitrogen excretion in ruminants in the future. KEY POINTS: • Epiberberine is the most effective inhibitor of rumen urease from Rhizoma Coptidis. • Urease accessory protein UreG is an effective target for design of urease inhibitor. • Epiberberine may be used as natural feed additive to reducing NH3 release in ruminants.


Assuntos
Berberina , Berberina/análogos & derivados , Animais , Berberina/farmacologia , Urease , Amônia , Cloretos , Rúmen , Inibidores Enzimáticos/farmacologia , Nitrogênio , Ruminantes
10.
Biochem Biophys Res Commun ; 710: 149892, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38581951

RESUMO

Chlorination is a potent disinfectant against various microorganisms, including bacteria and viruses, by inducing protein modifications and functional changes. Chlorine, in the form of sodium hypochlorite, stands out as the predominant sanitizer choice due to its cost-effectiveness and powerful antimicrobial properties. Upon exposure to chlorination, proteins undergo modifications, with amino acids experiencing alterations through the attachment of chloride or oxygen atoms. These modifications lead to shifts in protein function and the modulation of downstream signaling pathways, ultimately resulting in a bactericidal effect. However, certain survival proteins, such as chaperones or transcription factors, aid organisms in overcoming harsh chlorination conditions. The expression of YabJ, a highly conserved protein from Staphylococcus aureus, is regulated by a stress-activated sigma factor called sigma B (σB). This research revealed that S. aureus YabJ maintains its structural integrity even under intense chlorination conditions and harbors sodium hypochlorite molecules within its surface pocket. Notably, the pocket of S. aureus YabJ is primarily composed of amino acids less susceptible to chlorination-induced damage, rendering it resistant to such effects. This study elucidates how S. aureus YabJ evades the detrimental effects of chlorination and highlights its role in sequestering sodium hypochlorite within its structure. Consequently, this process enhances resilience and facilitates adaptation to challenging environmental conditions.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Humanos , Cloretos/metabolismo , Hipoclorito de Sódio/farmacologia , Hipoclorito de Sódio/metabolismo , Proteínas de Bactérias/metabolismo , Aminoácidos/metabolismo
11.
Sci Rep ; 14(1): 8597, 2024 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615119

RESUMO

Oral poisoning can trigger diverse physiological reactions, determined by the toxic substance involved. One such consequence is hyperchloremia, characterized by an elevated level of chloride in the blood and leads to kidney damage and impairing chloride ion regulation. Here, we conducted a comprehensive genome-wide analysis to investigate genes or proteins linked to hyperchloremia. Our analysis included functional enrichment, protein-protein interactions, gene expression, exploration of molecular pathways, and the identification of potential shared genetic factors contributing to the development of hyperchloremia. Functional enrichment analysis revealed that oral poisoning owing hyperchloremia is associated with 4 proteins e.g. Kelch-like protein 3, Serine/threonine-protein kinase WNK4, Serine/threonine-protein kinase WNK1 and Cullin-3. The protein-protein interaction network revealed Cullin-3 as an exceptional protein, displaying a maximum connection of 18 nodes. Insufficient data from transcriptomic analysis indicates that there are lack of information having direct associations between these proteins and human-related functions to oral poisoning, hyperchloremia, or metabolic acidosis. The metabolic pathway of Cullin-3 protein revealed that the derivative is Sulfonamide which play role in, increasing urine output, and metabolic acidosis resulted in hypertension. Based on molecular docking results analysis it found that Cullin-3 proteins has the lowest binding energies score and being suitable proteins. Moreover, no major variations were observed in unbound Cullin-3 and all three peptide bound complexes shows that all systems remain compact during 50 ns simulations. The results of our study revealed Cullin-3 proteins be a strong foundation for the development of potential drug targets or biomarker for future studies.


Assuntos
Cloretos , Proteínas Culina , Humanos , Acidose , Biomarcadores , Cloretos/efeitos adversos , Cloretos/toxicidade , Proteínas Culina/metabolismo , Halogênios , Simulação de Acoplamento Molecular , Proteínas Serina-Treonina Quinases/metabolismo , Proteína Quinase 1 Deficiente de Lisina WNK/metabolismo
12.
Food Microbiol ; 121: 104516, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38637078

RESUMO

Oxidation-reduction potential (ORP) is commonly used as a rapid measurement of the antimicrobial potential of free chlorine during industrial fresh produce washing. The current study tested the hypothesis that ORP can act as a "single variable" measurement of bacterial (vegetative and endospores) inactivation effectiveness with free chlorine irrespective of the water pH value. This situation has on occasion been assumed but never confirmed nor disproven. Chlorine-dosed pH 6.5 and 8.5 phosphate buffer solutions were inoculated with Escherichia coli (E. coli), Listeria innocua (L. innocua), or Bacillus subtilis (B. subtilis) endospores. ORP, free chlorine (FC), and log reduction were monitored after 5 s (for E. coli and L. innocua) and up to 30 min (for B. subtilis spores) of disinfection. Logistic and exponential models were developed to describe how bacteria reduction varied as a function of ORP at different pH levels. Validation tests were performed in phosphate buffered pH 6.5 and 8.5 cabbage wash water periodically dosed with FC, cabbage extract and a cocktail of Escherichia coli O157:H7 (E. coli O157:H7) and Listeria monocytogenes (L. monocytogenes). The built logistic and exponential models confirmed that at equal ORP values, the inactivation of the surrogate strains was not consistent across pH 6.5 and pH 8.5, with higher reductions at higher pH. This is the opposite of the well-known free chlorine-controlled bacterial inactivation, where the antibacterial effect is higher at lower pH. The validation test results indicated that in the cabbage wash water, the relationship between disinfection efficiency and ORP was consistent with the oxidant demand free systems. The study suggests that ORP cannot serve as a reliable single variable measurement to predict bacterial disinfection in buffered systems. When using ORP to monitor and control the antibacterial effectiveness of the chlorinated wash water, it is crucial to take into account (and control) the pH.


Assuntos
Escherichia coli O157 , Listeria monocytogenes , Listeria , Desinfecção/métodos , Cloro/farmacologia , Cloro/análise , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Oxidantes , Contagem de Colônia Microbiana , Manipulação de Alimentos/métodos , Cloretos , Oxirredução , Água/química , Antibacterianos , Concentração de Íons de Hidrogênio , Fosfatos
13.
Inorg Chem ; 63(15): 6776-6786, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38572830

RESUMO

The heme-containing chlorite dismutases catalyze the rapid and efficient decomposition of chlorite (ClO2-) to yield Cl- and O2, and the catalytic efficiency of chlorite dismutase from Dechloromonas aromatica (DaCld) in catalyzing the decomposition of bromite (BrO2-) was dependent on pH, which was supposed to be caused by the conversion of active Cpd I to the inactive Cpd II by proton-coupled electron transfer (PCET) from the pocket Tyr118 to the propionate side chain of heme at high pH. However, the direct evidence of PCET and how the pH affects the efficiency of DaCld, as well as whether Cpd II is really inactive, are still poorly understood. Here, on the basis of the high-resolution crystal structures, the computational models in both acidic (pH 5.0) and alkaline (pH 9.0) environments were constructed, and a series of quantum mechanical/molecular mechanical calculations were performed. On the basis of our calculation results, the O-Br bond cleavage of BrO2- always follows the homolytic mode to generate Cpd II rather than Cpd I. It is different from the O-O cleavage of O2/H2O2 or peracetic acid catalyzed by the other heme-containing enzymes. Thus, in the subsequent O-O rebound reaction, it is the Fe(IV)═O in Cpd II that combines with the O-Br radical. Because the porphyrin ring in Cpd II does not bear an unpaired electron, the previously suggested PCET from Tyr118 to the propionate side chain of heme was not theoretically recognized in an alkaline environment. In addition, the O-O rebound step in an alkaline solution corresponds to an energy barrier that is larger than that in an acidic environment, which can well explain the pH dependence of the activity of DaCld. In addition, the protonation state of the propionic acid side chains of heme and the surrounding hydrogen bond networks were calculated to have a significant impact on the barriers of the O-O rebound step, which is mainly achieved by affecting the reactivity of the Fe(IV)═O group in Cpd II. In an acidic environment, the relatively weaker coordination of the O2 atom to Fe leads to its higher reactivity toward the O-O rebound reaction. These observations may provide useful information for understanding the catalysis of chlorite dismutases.


Assuntos
Betaproteobacteria , Cloretos , Peróxido de Hidrogênio , Oxirredutases , Propionatos , Peróxido de Hidrogênio/química , Catálise , Prótons , Concentração de Íons de Hidrogênio , Heme/química
14.
Sci Rep ; 14(1): 7846, 2024 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-38570623

RESUMO

Previous studies have suggested that levels of sodium and chloride in the blood may be indicative of the prognosis of different medical conditions. Nevertheless, the assessment of the prognostic significance of the sodium-to-chloride (Na/Cl) ratio in relation to in-hospital mortality among individuals suffering from acute heart failure (AHF) remains unexplored. In this study, the participants were selected from the Medical Information Mart for Intensive Care IV database and divided into three groups based on the Na/Cl ratio level upon admission. The primary results were the mortality rate within the hospital. Cox regression, Kaplan-Meier curves, receiver operator characteristic (ROC) curve analysis and subgroup analyses were utilized to investigate the correlation between the admission Na/Cl ratio and outcomes in critically ill patients with AHF. A total of 7844 patients who met the selection criteria were included in this study. After adjusting for confounders, the multivariable Cox regression analysis revealed that the baseline Na/Cl ratio significantly elevated the risk of in-hospital mortality among critically ill patients with AHF (HR = 1.34, 95% CI 1.21-1.49). Furthermore, when the Na/Cl ratio was converted into a categorical factor and the initial tertile was taken as a point of comparison, the hazard ratios (HRs) and 95% confidence intervals (CIs) for the second and third tertiles were 1.27 (1.05-1.54) and 1.53 (1.27-1.84), respectively. Additionally, a P value indicating a significant trend of < 0.001 was observed. ROC curve analysis showed that Na/Cl ratio had a more sensitive prognostic value in predicting in-hospital mortality of AHF than the sodium or chloride level alone (0.564 vs. 0.505, 0.544). Subgroup examinations indicated that the association between the Na/Cl ratio upon admission and the mortality rate of critically ill patients with AHF remained consistent in the subgroups of hyponatremia and hypochlorhydria (P for interaction > 0.05). The linear relationship between the Na/Cl ratio and in-hospital mortality in AHF patients indicates a positive association.


Assuntos
Insuficiência Cardíaca , Cloreto de Sódio , Humanos , Cloretos , Mortalidade Hospitalar , Estado Terminal , Prognóstico , Sódio , Estudos Retrospectivos
15.
eNeuro ; 11(3)2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38471777

RESUMO

Synchronization in the gamma band (25-150 Hz) is mediated by PV+ inhibitory interneurons, and evidence is accumulating for the essential role of gamma oscillations in cognition. Oscillations can arise in inhibitory networks via synaptic interactions between individual oscillatory neurons (mean-driven) or via strong recurrent inhibition that destabilizes the stationary background firing rate in the fluctuation-driven balanced state, causing an oscillation in the population firing rate. Previous theoretical work focused on model neurons with Hodgkin's Type 1 excitability (integrators) connected by current-based synapses. Here we show that networks comprised of simple Type 2 oscillators (resonators) exhibit a supercritical Hopf bifurcation between synchrony and asynchrony and a gradual transition via cycle skipping from coupled oscillators to stochastic population oscillator (SPO), as previously shown for Type 1. We extended our analysis to homogeneous networks with conductance rather than current based synapses and found that networks with hyperpolarizing inhibitory synapses were more robust to noise than those with shunting synapses, both in the coupled oscillator and SPO regime. Assuming that reversal potentials are uniformly distributed between shunting and hyperpolarized values, as observed in one experimental study, converting synapses to purely hyperpolarizing favored synchrony in all cases, whereas conversion to purely shunting synapses made synchrony less robust except at very high conductance strengths. In mature neurons the synaptic reversal potential is controlled by chloride cotransporters that control the intracellular concentrations of chloride and bicarbonate ions, suggesting these transporters as a potential therapeutic target to enhance gamma synchrony and cognition.


Assuntos
Cloretos , Transmissão Sináptica , Transmissão Sináptica/fisiologia , Simulação por Computador , Interneurônios/fisiologia , Sinapses/fisiologia , Potenciais de Ação/fisiologia , Modelos Neurológicos
16.
Support Care Cancer ; 32(4): 256, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38546900

RESUMO

BACKGROUND: For patients with nasopharyngeal carcinoma (NPC), the incidence of malnutrition is quite high, and malnutrition has severe effects on NPC patients. However, there is currently no recognized gold standard or specific nutritional assessment tool available to assess malnutrition in NPC patients. Our objective was to develop and verify a new nomogram model for NPC patients. METHODS: Data were collected from NPC patients. To evaluate risk factors for malnutrition, univariate and multivariate logistic regression analyses were used. Based on the risk factors, a new nomogram model was developed. The efficacy of the model was evaluated and validated. RESULTS: Logistic regression analysis showed that age ≥ 65 years, the number of chemotherapy cycles completed ≥ 1, a high total radiation dose received, low body mass index (BMI), low albumin, and low chloride were the risk factors. The assessment effect of the new model was good by evaluation and validation; it can be used as an assessment tool for malnutrition in NPC patients. CONCLUSIONS: Age ≥ 65 years, completing ≥ 1 chemotherapy cycles, a high total radiation dose received, low BMI, low albumin, and low chloride levels are risk factors for malnutrition in NPC patients. The assessment effect of the new model, developed based on these risk factors, is good, and it can be used as an assessment tool for malnutrition in NPC patients.


Assuntos
Desnutrição , Neoplasias Nasofaríngeas , Humanos , Idoso , Carcinoma Nasofaríngeo/patologia , Nomogramas , Neoplasias Nasofaríngeas/radioterapia , Cloretos/uso terapêutico , Fatores de Risco , Desnutrição/epidemiologia , Desnutrição/etiologia , Albuminas
17.
Sci Total Environ ; 926: 172046, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38552983

RESUMO

Cadmium (Cd) contamination in rice ecosystems posed a critical challenge to global food security and environmental health. This study aimed to unveil the key mechanisms trough hydroponic experiments by which chloride (Cl-) promoted the absorption and accumulation of cadmium (Cd) in rice plants. The findings elucidated that the addition of Cl- increased Cd uptake by rice roots (5.1 % âˆ¼ 61 %), acting both directly by enhancing root morphology and indirectly through regulating of the main transporter genes of Cd. The study unveiled that Cl- addition significantly improves Cd bioavailability in roots, which was discernible through the augmentation of Cd concentration and proportion in subcellular fractions, coupled with elevated energy values in key cellular components. Moreover, Cl- addition further augmented the intricate process of Cd transport from roots to shoots (16.1- 86.7 %), which was mainly attributed to the underexpression of OsHMA3 and the decrease in the formation of sulfuhydryl substances. This research provides a comprehensive understanding of the complex mechanisms governing Cd dynamics in rice plants in the presence of Cl-. By elucidating these processes, our findings not only contribute to fundamental knowledge in plant metal uptake but also hold promising implications for mitigating Cd contamination in rice cultivation systems.


Assuntos
Oryza , Poluentes do Solo , Cádmio , Oryza/fisiologia , Cloretos , Ecossistema , Transporte Biológico , Raízes de Plantas
18.
Int J Biol Macromol ; 265(Pt 1): 130767, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38471601

RESUMO

The role of anionic counterions of divalent metal salts in alginate gelation and hydrogel properties has been thoroughly investigated. Three anions were selected from the Hofmeister series, namely sulphate, acetate and chloride, paired in all permutations and combinations with divalent metal cations like calcium, zinc and copper. Spectroscopic analysis revealed the presence of anions and their interaction with the respective metal cations in the hydrogel. The data showed that the gelation time and other hydrogel properties were largely controlled by cations. However, subtle yet significant variations in viscoelasticity, water uptake, drug release and cytocompatibility properties were anion dependent in each cationic group. Computational modelling based study showed that metal-anion-alginate configurations were energetically more stable than the metal-alginate models. The in vitro and in silico studies concluded that acetate anions preceded chlorides in the drug release, swelling and cytocompatibility fronts, followed by sulphate anions in each cationic group. Overall, the data confirmed that anions are an integral part of the metal-alginate complex. Furthermore, anions offer a novel option to further fine-tune the properties of alginate hydrogels for myriads of applications. In addition, full exploration of this novel avenue would enhance the usability of alginate polymers in the pharmaceutical, environmental, biomedical and food industries.


Assuntos
Hidrogéis , Sais , Hidrogéis/química , Alginatos/química , Cálcio/química , Cátions , Cloretos , Água , Sulfatos , Acetatos
19.
Int Heart J ; 65(2): 237-245, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38556334

RESUMO

Serum chloride level has clinical significance in the prognosis of heart failure. Little is known regarding the association between serum chloride levels and in-hospital mortality in patients with heart failure.This retrospective study used clinical data obtained from the Medical Information Mart for Intensive Care Database. The study cohort comprised patients who were categorized on the basis of their serum chloride levels, and the primary endpoint was in-hospital mortality. To assess the impact of serum chloride levels at the time of intensive care unit admission on in-hospital mortality, we used various statistical approaches, including multivariable logistic regression models, a generalized additive model, and a two-piecewise linear regression model. In addition, subgroup analysis was conducted to examine the robustness of the main findings.This study comprised 15,983 participants. When compared with the reference group (Q5), the groups with the highest (Q7) and lowest (Q1) blood chloride levels exhibited increased in-hospital mortality, with fully adjusted odds ratios (ORs) of 1.36 [95% confidence interval (CI): 1.08-1.71] and 1.25 (95% CI: 1-1.56), respectively. A U-shaped relationship was observed between blood chloride levels and in-hospital mortality, with the lowest risk observed at a threshold of 105.017 mmol/L. The effect sizes and corresponding CIs below and above the threshold were 0.969 (95% CI: 0.957-0.982) and 1.039 (95% CI: 1.002-1.076), respectively. Stratified analyses demonstrated the robustness of this correlation.The relationship between serum chloride levels and in-hospital mortality in patients with heart failure was U-shaped, with an inflection point of 105.017 mmol/L.


Assuntos
Cloretos , Insuficiência Cardíaca , Humanos , Mortalidade Hospitalar , Estudos Retrospectivos , Unidades de Terapia Intensiva
20.
Carbohydr Res ; 538: 109078, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38513462

RESUMO

N-(4-N'-pyridine-benzylcarbonyl chloride) chitosan (CBPyC), N-p-biguanidine benzoyl chitosan (CSBG), and N-(p-biguanidine -1-pyridine-4-benzylcarbonyl chloride) chitosan (CSQPG) were synthesized. The structures of prepared chitosan derivatives were characterized using nuclear magnetic resonance spectroscopy (NMR) and ultraviolet-visible (UV-vis) spectroscopy, and the degree of substitution was determined through elemental analysis (EA) and evaluated on the basis of the integral values in 1H NMR. The antibacterial activities of chitosan derivatives against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were investigated in vitro using antibacterial rate, minimal inhibitory concentration and minimum bacterial concentration assays. The antibiofilm activity was also assessed using the crystal violet assay. CSQPC exhibited higher antibacterial and antibiofilm activities against E. coli and S. aureus compared to CBPyC and CSBG. The antibacterial rate of CSQPG against E. coli and S. aureus at a concentration of 0.5 mg/mL was 43.3% and 100%, respectively. The biofilm inhibition rate of CSQPG at 0.5 MIC against E. coli and S. aureus was 56.5% and 69.1%, respectively. At a concentration of 2.5 mg/mL, the biofilm removal rates of E. coli and S. aureus were 72.9% and 90.1%, respectively. The antibacterial and antibiofilm activities of CSQPG were better than CSBG and CBPyC, and the combination of guanidine and quaternary ammonium further improved the positive charge density of chitosan and enhanced its antibacterial activity.


Assuntos
Quitosana , Quitosana/farmacologia , Quitosana/química , Sais , Staphylococcus aureus , Escherichia coli , Cloretos , Biofilmes , Compostos de Amônio Quaternário/farmacologia , Compostos de Amônio Quaternário/química , Antibacterianos/farmacologia , Antibacterianos/química , Testes de Sensibilidade Microbiana , Piridinas
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