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One of the greatest challenges encountered by enteric pathogens is responding to rapid changes of nutrient availability in host. However, the mechanisms by which pathogens sense gastrointestinal signals and exploit available host nutrients for proliferation remain largely unknown. Here, we identified a two-component system in Vibrio parahaemolyticus, TtrRS, which senses environmental tetrathionate and subsequently activates the transcription of the ttrRS-ttrBCA-tsdBA gene cluster to promote V. parahaemolyticus colonization of adult mice. We demonstrated that TsdBA confers the ability of thiosulfate oxidation to produce tetrathionate which is sensed by TtrRS. TtrRS autoregulates and directly activates the transcription of the ttrBCA and tsdBA gene clusters. Activated TtrBCA promotes bacterial growth under micro-aerobic conditions by inducing the reduction of both tetrathionate and thiosulfate. TtrBCA and TsdBA activation by TtrRS is important for V. parahaemolyticus to colonize adult mice. Therefore, TtrRS and their target genes constitute a tetrathionate-responsive genetic circuit to exploit the host available sulfur compounds, which further contributes to the intestinal colonization of V. parahaemolyticus.
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Proteínas Bacterianas , Vibriosis , Vibrio parahaemolyticus , Vibrio parahaemolyticus/metabolismo , Vibrio parahaemolyticus/genética , Animales , Ratones , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Compuestos de Azufre/metabolismo , Regulación Bacteriana de la Expresión Génica , Femenino , Ratones Endogámicos C57BLRESUMEN
AIMS AND OBJECTIVES: To construct a predictive nomogram of the risk of nosocomial infections among patients after cardiac valve replacement surgery. BACKGROUND: Nosocomial infections are a standout challenge that worsens the prognosis of patients after valve replacement surgery. However, studies on the nomogram of nosocomial infections in these patients have remained scarce. DESIGN: A retrospective cohort study. METHODS: Patients (n = 720) following valve replacement surgery from 2018 to 2019 were selected. LASSO regression and multivariate logistic regression were utilised to ascertain predictors of nosocomial infections. The predictive performance of the nomogram was appraised by calibration and discrimination. Decision and impact curves were used to assess the clinical utility. Internal validation was implemented via 1000 bootstrap samples to mitigate overfitting. TRIPOD guidelines were used in this study. RESULTS: One hundred and fifty one patients (20.97%) experienced nosocomial infections following valve replacement surgery. Heart failure, preoperative anaemia, valve material, American Society of Anesthesiologists score ≥ IV, prolonged duration of surgery, duration of mechanical ventilation ≥ 24 h and indwelling nasogastric tube were predictors of nosocomial infections. Using these variables, we developed a predictive nomogram of the occurrence of nosocomial infections and the internal validation results demonstrated good discrimination and calibration of the nomogram. The clinical decision and impact curve revealed significant clinical utility. CONCLUSIONS: The present study constructed a nomogram for predicting the risk of nosocomial infections in patients following cardiac valve replacement surgery. This nomogram may strengthen the effective screening of patients at high risk of nosocomial infections. RELEVANCE TO CLINICAL PRACTICE: This risk warning tool can assist clinical staff in making decisions and providing individualised infection control measures for patients, which has a significant reference value for clinical practice. NO PATIENT OR PUBLIC CONTRIBUTION: The data for this study were obtained from the hospital database, and the entire process of the study did not involve patient participation.
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Infección Hospitalaria , Nomogramas , Humanos , Estudios Retrospectivos , Infección Hospitalaria/epidemiología , Pronóstico , Válvulas CardíacasRESUMEN
Objective: To investigate the role of aberrant Dyrk1a expression in phosphorylation modification at the α-synuclein serine 129 (Ser129) site to analyze its molecular mechanism in mediating apoptosis of PD. Methods: The protein level of P-α-synuclein (Ser129), α-synuclein, Bcl-2, Bax, active caspase 3, GSK3ß, PI3K, AKT, and cyclinD1 were detected. The mRNA transcript levels of Dyrk1a and DAT and protein levels of IL-1ß, IL-6, COX-2, and TNF-α were detected. Results: P-α-synuclein (Ser129), α-synuclein, Bax, active caspase 3, GSK3ß, and cyclinD1 expressions were decreased in Dyrk1a-AAV-ShRNA (P < 0.05), and Bcl-2, AKT, and PI3K expressions were increased (P < 0.05). Increased TH protein expression was shown in Dyrk1a-AAV-ShRNA (P < 0.05). Dyrk1a mRNA was decreased in the Dyrk1a-AAV-ShRNA group (P < 0.05), and DAT mRNA was increased (P < 0.05). IL-1ß, IL-6, COX-2, and TNF-α protein levels were decreased in Dyrk1al-AAV-Sh-RNA (P < 0.05). Transcriptome sequencing showed that Fam220a, which was expected to activate STAT family protein binding activity and participate in the negative regulation of transcription through RNA polymerase II and protein dephosphorylation showed differentially upregulated expression. The untargeted metabolome showed that the major compounds in the Dyrk1a-AAV-ShRNA group were hormones and transmission mediators and the most metabolism-related pathways. Fam220a showed differentially upregulated expression, and differentially expressed genes were enriched for the neuroactive ligand-receptor interaction, vascular smooth muscle contraction, and melanogenesis-related pathways. Conclusion: Abnormal Dyrk1a expression can affect α-synuclein phosphorylation modifications, and dyrk1a knockdown activates the PI3K/AKT pathway and reduces dopaminergic neuron apoptosis. It provides a theoretical basis for the group to further investigate the molecular mechanism.
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OBJECTIVE: To investigate the molecular epidemiology of HIV-1 in Heilongjiang, China, and try to spot signs of new circulating recombinant form (CRF) in this region. DESIGN: A molecular epidemiological study was conducted in Heilongjiang, China during 2011-2020. METHODS: Plasma samples were collected from three HIV-1-positive patients (two MSM and one man lacking risk factor information). The near full-length genome sequences (NFLGs) of a novel CRF were then obtained and subjected to phylogenetic analysis using Mega 7.0.26. Recombination analysis was performed by the jumping profile Hidden Markov Model (jpHMM). Finally, the origin time of this novel CRF was inferred using the Bayesian phylogenetic analysis in Beast v1.10.4. RESULTS: The three NFLGs formed a distinct monophyletic cluster in the neighbor-joining (NJ) tree. Recombination analysis revealed that the recombinant genome was composed of five segments derived from CRF01_AE, subtypes B, and C, but further confirmed to be a second-generation recombinant form of CRF01_AE/CRF07_BC by a comparison of genome maps and subregion phylogenetic analysis and, therefore, designated as CRF136_0107. With Bayesian phylogenetic analysis, CRF136_0107 was estimated to originate around 2010-2011. CONCLUSION: A novel HIV-1 CRF01_AE/CRF07_BC second-generation CRF called CRF136_0107 was identified among MSM in Heilongjiang, a northeast province of China.
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Infecciones por VIH , Seropositividad para VIH , VIH-1 , Minorías Sexuales y de Género , Masculino , Humanos , Homosexualidad Masculina , VIH-1/genética , Filogenia , Recombinación Genética , Teorema de Bayes , Infecciones por VIH/epidemiología , Infecciones por VIH/genética , Genoma Viral , Análisis de Secuencia de ADN , China/epidemiología , GenotipoRESUMEN
PREMISE OF THE STUDY: Tetracentron sinense (Trochodendraceae) is a Tertiary relict endemic to East Asia. Microsatellite markers were developed and characterized to investigate the population genetics of the species. METHODS AND RESULTS: Microsatellite markers were isolated from the genome of T. sinense using the protocol of Fast Isolation by AFLP of Sequences COntaining repeats (FIASCO). Eight polymorphic microsatellite markers were assessed in 44 samples collected from three wild populations. The number of alleles observed for each locus ranged from two to five. The observed and expected heterozygosities ranged from 0.0000 to 0.9375 and 0.0000 to 0.7681, respectively. CONCLUSIONS: The microsatellite markers will be helpful in further studies of the population genetics and phylogeography of T. sinense.
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Cartilla de ADN/genética , Magnoliopsida/genética , Repeticiones de Microsatélite/genética , Polimorfismo Genético , Alelos , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Secuencia de Bases , ADN de Plantas/genética , Sitios Genéticos , Marcadores Genéticos , Genética de Población , Magnoliopsida/clasificación , Datos de Secuencia Molecular , Hojas de la Planta/clasificación , Hojas de la Planta/genética , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
PREMISE OF THE STUDY: Microsatellite markers were developed for the dove tree, Davidia involucrata (Cornaceae), a Tertiary relict currently endemic to China, to investigate its population genetics and phylogeography. METHODS AND RESULTS: Using the Fast Isolation by AFLP of Sequences Containing repeats (FIASCO) protocol, nine polymorphic microsatellite loci were identified and screened in 44 individuals from three wild populations of D. involucrata. The number of alleles per locus ranged from two to three, while the observed heterozygosity and expected heterozygosity ranged from 0.0000 to 0.6000 and from 0.0000 to 0.6323, respectively. CONCLUSIONS: These new microsatellite loci will facilitate further studies of the population genetics and phylogeography of D. involucrata, as well as of the evolutionary history of the plant and other Tertiary relicts endemic to East Asia.
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Cornaceae/genética , Repeticiones de Microsatélite/genética , ADN de Cloroplastos/genética , ADN de Plantas/genética , DemografíaRESUMEN
Autophagy degrades phagocytosed damaged organelles, misfolded proteins, and various pathogens through lysosomes as an essential way to maintain cellular homeostasis. Autophagy is a tightly regulated cellular self-degradation process that plays a crucial role in maintaining normal cellular function and homeostasis in the body. The NLRP3 inflammasome in neuroinflammation is a vital recognition receptor in innate cellular immunity, sensing external invading pathogens and endogenous stimuli and further triggering inflammatory responses. The NLRP3 inflammasome forms an inflammatory complex by recognizing DAMPS or PAMPS, and its activation triggers caspase-1-mediated cleavage of pro-IL-1ß and pro-IL-18 to promote the inflammatory response. In recent years, it has been reported that there is a complex interaction between autophagy and neuroinflammation. Strengthening autophagy can regulate the expression of NLRP3 inflammasome to reduce neuroinflammation in neurodegenerative disease and protect neurons. However, the related mechanism is not entirely clear. The formation of protein aggregates is one of the standard features of Neurodegenerative diseases. A large number of toxic protein aggregates can induce inflammation. In theory, activation of the autophagy pathway can remove the potential toxicity of protein aggregates and delay the progression of the disease. This article aims to review recent research on the interaction of autophagy, NLRP3 inflammasome, and protein aggregates in Alzheimer's disease (AD) and Parkinson's disease (PD), analyze the mechanism and provide theoretical references for further research in the future.
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Vibrio parahaemolyticus is one of the most important food-borne pathogens that cause economic and public health problems worldwide. Quorum sensing (QS) is a way for the cell-cell communication between bacteria that controls a wide spectrum of processes and phenotypic behaviors. In this study, we performed a systematic research of LuxR family regulators in V. parahaemolyticus and found that they influence the bacterial growth and biofilm formation. We then established a QS reporter plasmid based on bioluminescence luxCDABE operon of Vibrio harveyi and demonstrated that several LuxR family regulators integrated into QS circuit in V. parahaemolyticus. Thereinto, a novel LuxR family regulator, named RobA, was identified as a global regulator by RNA-sequencing analyses, which affected the transcription of 515 genes in V. parahaemolyticus. Subsequent studies confirmed that RobA regulated the expression of the exopolysaccharides (EPS) synthesis cluster and thus controlled the biofilm formation. In addition, bioluminescence reporter assays showed that RobA plays a key role in the QS circuit by regulating the expression of opaR, aphA, cpsQ-mfpABC, cpsS, and scrO. We further demonstrated that the regulation of RobA to EPS and MfpABC depended on OpaR and CpsQ, which combined the QS signal with bis-(3'-5')-cyclic dimeric GMP to construct a complex regulatory network of biofilm formation. Our data provided new insights into the bacterial QS mechanisms and biofilm formation in V. parahaemolyticus.
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Fluorine and tin co-doped rutile TiO2 nanorod arrays are grown on fluorine-doped tin oxide substrates by a hydrothermal process and are used as photoanodes to perform photoelectrochemical water oxidation. Fluorine and tin co-doping synergistically enhances the ultraviolet light conversion efficiency of the resulting TiO2, which enables its photocurrent density of photoelectrochemical water oxidation to be more than four times that of the undoped samples. Such improvement in photoelectrochemical performance is attributed to changes in the electronic structure of the rutile TiO2 due to fluorine and tin co-doping. It is found that introducing tin into the matrix of rutile TiO2 can improve the charge separation efficiency because of the enhanced migration of photogenerated electrons from the conduction band of TiO2 to that of SnO2 that occurs at local sites, while fluorine doping can greatly reduce the recombination of the photogenerated electron-hole pairs due to the presence of the Ti3+ state that is produced to compensate for the charge difference between F- ions and O2- ions. It is envisaged that the fluorine and tin co-doped TiO2 nanorod arrays described will provide valuable platforms for wide photocatalytic applications that are not merely limited to photoelectrochemical water oxidation.