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Arbuscular mycorrhizal (AM) fungi establish mutualistic symbiosis with a wide range of terrestrial plants, including rice. However, the mechanisms underlying the initiation of AM symbiosis are yet to be elucidated, particularly in nonleguminous plants. We previously demonstrated that chitin elicitor receptor kinase 1 (OsCERK1), a lysin motif receptor-like kinase essential for chitin-triggered immunity, also plays a key role in AM symbiosis in rice. However, the mechanisms underlying the regulation of switching between immunity and symbiosis by OsCERK1 are yet to be fully elucidated. SYMBIOSIS RECEPTOR-LIKE KINASE (SYMRK)/DOES NOT MAKE INFECTIONS 2 (DMI2) is a leucine-rich repeat receptor-like kinase associated with both root nodule symbiosis and AM symbiosis in legumes. The homolog of SYMRK in rice, OsSYMRK, has a shorter form than that in legumes because OsSYMRK lacks a malectin-like domain (MLD). The MLD reportedly contributes to symbiosis in Lotus japonicus; however, the contribution of OsSYMRK to AM symbiosis in rice remains unclear. Phylogenetic analyses indicated that the MLD of SYMRK/DMI2 is widely conserved even in mosses and ferns but absent in commelinids, including rice. To understand the function of OsSYMRK, we produced an Ossymrk knockout mutant using genome editing technology. AM colonization was mostly abolished in Ossymrk with a more severe phenotype than Oscerk1. Ca2+ spiking against chitin tetramer was also diminished in Ossymrk. In contrast, comparable defense responses against chitin heptamer to the wild type were observed in Ossymrk. Bimolecular fluorescence complementation studies demonstrating an interaction between OsSYMRK and OsCERK1 indicate that OsSYMRK may play an important role in switching from immunity to symbiosis through the interaction with OsCERK1 in rice.
Assuntos
Micorrizas , Oryza , Simbiose/genética , Oryza/fisiologia , Filogenia , Micorrizas/fisiologia , Fosfotransferases/genética , Quitina , Proteínas de Plantas/genéticaRESUMO
BACKGROUND: Long-term outcome of patients with locally advanced gastric cancer (LAGC) who achieved a pathological complete response (pCR) was scarcely discussed, and never had the factors affecting the prognosis of pCR patients been investigated. METHODS: We retrospectively reviewed all patients who achieved a pCR to neoadjuvant chemotherapy (NAC) in Jinling Hospital. The 3- and 5-year overall survival (OS) and progression-free survival (PFS) were calculated with the Kaplan-Meier method. Meanwhile, univariate and multivariate COX regression analysis was applied to identify prognostic factors affecting patients' survival. RESULTS: A total of 37 consecutive LAGC patients with pCR were included. The 3- and 5-year OS rates were 88.8% and 78.6%, and the 3- and 5-year PFS rates were 86.5% and 75.8%. In the multivariate COX model, NAC duration of more than 3 cycles (HR 0.11 [0.02-0.62], P = 0.013) and poorly differentiated tumor at diagnosis (HR 0.17 [0.03-0.95], P = 0.043) were detected as protective factors for patients OS. Whereas for PFS, NAC duration (HR 0.12 [0.02-0.67], P = 0.015) was the only protective factor confirmed, with tumor differentiation at diagnosis exhibiting marginal significance (HR 0.21 [0.04-1.09], P = 0.063). CONCLUSIONS: Patients with LAGC who achieved a pCR displayed favorable long-term survival outcome, especially those with adequate cycles (≥ 3) of NAC. Besides, poor differentiation at diagnosis might also predict the better OS when pCR achieved.
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Segunda Neoplasia Primária , Neoplasias Gástricas , Humanos , Terapia Neoadjuvante , Estadiamento de Neoplasias , Neoplasias Gástricas/tratamento farmacológico , Estudos Retrospectivos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , PrognósticoRESUMO
Background: Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) have been associated with worse patient outcomes and higher costs of care than methicillin-susceptible (MSSA) infections. However, since prior studies found these differences, the healthcare landscape has changed, including widespread dissemination of community-associated strains of MRSA. We sought to provide updated estimates of the excess costs of MRSA infections. Methods: We conducted a retrospective analysis using data from the National Inpatient Sample from the Agency for Healthcare Research and Quality for the years 2010-2014. We calculated costs for hospitalizations, including MRSA- and MSSA-related septicemia and pneumonia infections, as well as MRSA- and MSSA-related infections from conditions classified elsewhere and of an unspecified site ("other infections"). Differences in the costs of hospitalization were estimated using propensity score-adjusted mortality outcomes for 2010-2014. Results: In 2014, estimated costs were highest for pneumonia and sepsis-related hospitalizations. Propensity score-adjusted costs were significantly higher for MSSA-related pneumonia ($40725 vs $38561; P = .045) and other hospitalizations ($15578 vs $14792; P < .001) than for MRSA-related hospitalizations. Similar patterns were observed from 2010 to 2013, although crude cost differences between MSSA- and MRSA-related pneumonia hospitalizations rose from 25.8% in 2010 to 31.0% in 2014. Compared with MSSA-related hospitalizations, MRSA-related hospitalizations had a higher adjusted mortality rate. Conclusions: Although MRSA infections had been previously associated with higher hospitalization costs, our results suggest that, in recent years, costs associated with MSSA-related infections have converged with and may surpass costs of similar MRSA-related hospitalizations.
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Custos de Cuidados de Saúde , Hospitalização/economia , Infecções Estafilocócicas/economia , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/isolamento & purificação , Adulto , Idoso , Humanos , Resistência a Meticilina , Pessoa de Meia-Idade , Estudos Retrospectivos , Staphylococcus aureus/efeitos dos fármacos , Estados Unidos/epidemiologiaRESUMO
Data from the National Inpatient Sample show that the decrease in hospitalizations related to methicillin-resistant Staphylococcus aureus (MRSA) infections between 2010 and 2014 primarily reflected declines in skin and soft tissue infections. Hospitalizations related to invasive MRSA remained largely unchanged.
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Hospitalização/tendências , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Hospitalização/estatística & dados numéricos , Humanos , Pneumonia/epidemiologia , Pneumonia/microbiologia , Infecções dos Tecidos Moles/tratamento farmacológico , Infecções dos Tecidos Moles/epidemiologia , Infecções dos Tecidos Moles/microbiologia , Infecções Cutâneas Estafilocócicas/tratamento farmacológico , Infecções Cutâneas Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Estados Unidos/epidemiologiaRESUMO
The elongation factor Tu (EF-Tu) receptor (EFR) in cruciferous plants specifically recognizes the N-terminal acetylated elf18 region of bacterial EF-Tu and thereby activates plant immunity. It has been demonstrated that Arabidopsis EFR confers broad-spectrum bacterial resistance in the EFR transgenic solanaceous plants. Here, the transgenic rice plants (Oryza sativa L. ssp. japonica cv. Zhonghua 17) and cell cultures with constitutive expression of AtEFR were developed to investigate whether AtEFR senses EF-Tu and thus enhances bacterial resistance in the monocot plants. We demonstrated that the Xanthomonas oryzae-derived elf18 peptide induced oxidative burst and mitogen-activated protein kinase activation in the AtEFR transgenic rice cells and plants, respectively. Pathogenesis-related genes, such as OsPBZ1, were upregulated dramatically in transgenic rice plant and cell lines in response to elf18 stimulation. Importantly, pretreatment with elf18 triggered strong resistance to X. oryzae pv. oryzae in the transgenic plants, which was largely dependent on the AtEFR expression level. These plants also exhibited enhanced resistance to rice bacterial brown stripe, but not to rice fungal blast. Collectively, the results indicate that the rice plants with heterologous expression of AtEFR recognize bacterial EF-Tu and exhibit enhanced broad-spectrum bacterial disease resistance and that pattern recognition receptor-mediated immunity may be manipulated across the two plant classes, dicots and monocots.
Assuntos
Proteínas de Arabidopsis/metabolismo , Imunidade Inata , Oryza/genética , Oryza/imunologia , Fator Tu de Elongação de Peptídeos/metabolismo , Imunidade Vegetal , Receptores de Reconhecimento de Padrão/metabolismo , Sequência de Aminoácidos , Resistência à Doença , Ativação Enzimática , Regulação da Expressão Gênica de Plantas , Magnaporthe/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Dados de Sequência Molecular , Oryza/microbiologia , Peptídeos/química , Peptídeos/metabolismo , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Xanthomonas/fisiologiaRESUMO
A high-glucose environment is involved in the progression of diabetes mellitus (DM). This study aims to explore the regulatory effects of quercetin (QUE) on autophagy and apoptosis after myocardial injury in rats with DM. The type 2 DM rat models were constructed using low-dose streptozotocin (STZ) treatment combined with a high-carbohydrate (HC) diet in vivo. Compared with the control group, the body weight was decreased, whereas blood pressure, blood glucose, and the LVW/BW ratio were increased in the diabetic group. The results showed that the myocardial fibers were disordered in the diabetic group. Moreover, we found that the myocardial collagen fibers, PAS-positive cells, and apoptosis were increased, whereas the mitochondrial structure was destroyed and autophagic vacuoles were significantly reduced in the diabetic group compared with the control group. The expression levels of autophagy-related proteins LC3 and Beclin1 were decreased, whereas the expression levels of P62, Caspae-3, and Bax/Bcl-2 were increased in the diabetic group in vitro and in vivo. Moreover, QUE treatment alleviated the cellular oxidative stress reaction under high-glucose environments. The results of immunoprecipitation (IP) showed that the autophagy protein Beclin1 was bound to Bcl-2, and the binding capacity increased in the HG group, whereas it decreased after QUE treatment, suggesting that QUE inhibited the binding capacity between Beclin1 and Bcl-2, thus leading to the preservation of Beclin1-induced autophagy. In addition, the blood pressure, blood glucose, and cardiac function of rats were improved following QUE treatment. In conclusion, QUE suppressed diabetic myocardial injury and ameliorated cardiac function by regulating myocardial autophagy and inhibition of apoptosis in diabetes through the AMPK/mTOR signaling pathway.
Assuntos
Proteínas Quinases Ativadas por AMP , Apoptose , Autofagia , Diabetes Mellitus Experimental , Quercetina , Transdução de Sinais , Serina-Treonina Quinases TOR , Animais , Autofagia/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Quercetina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Masculino , Proteínas Quinases Ativadas por AMP/metabolismo , Ratos Sprague-Dawley , Ratos , Modelos Animais de Doenças , Miocárdio/metabolismo , Miocárdio/patologia , Estreptozocina , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/tratamento farmacológico , Cardiomiopatias Diabéticas/metabolismo , Cardiomiopatias Diabéticas/prevenção & controle , Fitoterapia , Proteína Beclina-1/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/complicaçõesRESUMO
XA21, as a pattern recognition receptor in rice, senses the quorum-sensing (QS) signal molecule Ax21 secreted by Xanthomonas oryzae pv. oryzae (Xoo) and mediates hypersensitive response-like immunity against the pathogen. However, for the infection of another pathovar, X. o. pv. oryzicola (Xoc), relatively weak defense responses are observed in XA21-containing rice cultivars. In the present study, we demonstrated that the Xoc Δax21 mutant caused more severe disease symptoms than the wild type in XA21 rice cv. IRBB21, but not in non-Xa21 rice cv. Taipei 309. The substance(s) secreted by the wild-type Xoc strain, but not those by the ax21 mutant triggered host immunity against Xoo PXO99 Δax21 in Xa21 rice. Immunoblot analysis corroborated that Xoc, like Xoo, synthesizes and secretes Ax21. Furthermore, the membrane fusion protein RaxA was demonstrated to be required, but the ATP-binding cassette transporter RaxB was dispensable for Ax21 secretion in Xoc. In addition, we demonstrated that Ax21 functions as a QS signal molecule that regulates biofilm formation in Xoc. However, Ax21 signaling is dispensable for bacterial motility, the production of extracellular polysaccharide and protease secretion in Xoc. Interestingly, the two-component system RaxR/H was involved in the regulation of bacterial motility and the regulation was likely independent on Ax21 signaling in Xoc. Taken together, the results indicated that Ax21 secreted by Xoc might induce plant immunity that plays a significant role in rice defense against the pathogen infection.
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Given the enormous value that project failure brings to individuals and organizations, a large number of scholars have explored the antecedents that affect employees' learning from project failure. However, few scholars have paid attention to how individuals' affective states interact with cognition patterns to learn from failure. Based on cognitive behavioral theory, this paper explores the relationship between employees' different daily affective states and learning from project failure and incorporates the mediating role of error management strategy and the moderating role of project commitment. By using SPSS and Amos software, hierarchical regression analysis of questionnaire data collected from 774 employees in high-tech firms in China indicates that (1) positive/negative affective states positively/negatively affect learning from failure, respectively; (2) error management strategy mediates the relationship between daily affective states and learning from project failure; and (3) project commitment moderates the relationship between negative affective states and error management strategy; specifically, this relationship is weaker when project commitment is stronger. However, the moderating effect of project commitment on the relationship between positive affective states and error management strategy is not supported. The results further expand the research related to learning from failure and have practical implications for failure management in high-tech enterprises.
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Background: Owing to the complex pathophysiological features and heterogeneity of sepsis, current diagnostic methods are not sufficiently precise or timely, causing a delay in treatment. It has been suggested that mitochondrial dysfunction plays a critical role in sepsis. However, the role and mechanism of mitochondria-related genes in the diagnostic and immune microenvironment of sepsis have not been sufficiently investigated. Methods: Mitochondria-related differentially expressed genes (DEGs) were identified between human sepsis and normal samples from GSE65682 dataset. Least absolute shrinkage and selection operator (LASSO) regression and the Support Vector Machine (SVM) analyses were carried out to locate potential diagnostic biomarkers. Gene ontology and gene set enrichment analyses were conducted to identify the key signaling pathways associated with these biomarker genes. Furthermore, correlation of these genes with the proportion of infiltrating immune cells was estimated using CIBERSORT. The expression and diagnostic value of the diagnostic genes were evaluated using GSE9960 and GSE134347 datasets and septic patients. Furthermore, we established an in vitro sepsis model using lipopolysaccharide (1 µg/mL)-stimulated CP-M191 cells. Mitochondrial morphology and function were evaluated in PBMCs from septic patients and CP-M191 cells, respectively. Results: In this study, 647 mitochondrion-related DEGs were obtained. Machine learning confirmed six critical mitochondrion-related DEGs, including PID1, CS, CYP1B1, FLVCR1, IFIT2, and MAPK14. We then developed a diagnostic model using the six genes, and receiver operating characteristic (ROC) curves indicated that the novel diagnostic model based on the above six critical genes screened sepsis samples from normal samples with area under the curve (AUC) = 1.000, which was further demonstrated in the GSE9960 and GSE134347 datasets and our cohort. Importantly, we also found that the expression of these genes was associated with different kinds of immune cells. In addition, mitochondrial dysfunction was mainly manifested by the promotion of mitochondrial fragmentation (p<0.05), impaired mitochondrial respiration (p<0.05), decreased mitochondrial membrane potential (p<0.05), and increased reactive oxygen species (ROS) generation (p<0.05) in human sepsis and LPS-simulated in vitro sepsis models. Conclusion: We constructed a novel diagnostic model containing six MRGs, which has the potential to be an innovative tool for the early diagnosis of sepsis.
Assuntos
Mitocôndrias , Sepse , Humanos , Mitocôndrias/genética , DNA Mitocondrial , Sepse/diagnóstico , Sepse/genética , Área Sob a Curva , Ontologia Genética , LipopolissacarídeosRESUMO
BACKGROUND: Timely and accurate microbial diagnosis is important in managing patients with infected pancreatic necrosis (IPN). AIMS: To evaluate the diagnostic performance of Metagenomic next-generation sequencing (mNGS) in patients with suspected IPN. METHODS: The clinical data of 40 patients with suspected IPN who underwent CT-guided pancreatic fluid aspiration were retrospectively analyzed. Microbial culture and mNGS were simultaneously applied to identify the potential pathogens. The diagnostic performance of the mNGS was assessed by sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: The mNGS report can be obtained significantly earlier than culture methods (42 (36-62 h) vs. 60 (42-124 h), P = 0.032). Across all the study samples, seven species of bacteria and two species of fungi were reported accordingly to the culture results, while 22 species of bacteria and two species of fungi were detected by mNGS. The sensitivity, specificity, NPV, and PPV of mNGS were 88.0%, 100%, 83.33%, and 100%, respectively. CONCLUSIONS: The diagnostic accuracy of mNGS in patients with suspected IPN is satisfactory. Moreover, mNGS may broaden the range of identifiable infectious pathogens and provide a more timely diagnosis.
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Pancreatite Necrosante Aguda , Humanos , Pancreatite Necrosante Aguda/diagnóstico , Estudos Retrospectivos , Pâncreas , Sequenciamento de Nucleotídeos em Larga Escala , Tomografia Computadorizada por Raios X , Sensibilidade e EspecificidadeRESUMO
Shikonin(SK) is a natural small molecule naphthoquinone compound, which has anti-cancer activity in various human malignant tumors. Pyrroline-5-carboxylate reductase 1(PYCR1) is involved in tumorigenesis and regulates various cellular processes, including growth, invasion, migration, and apoptosis. However, the effect of SK and PYCR1 on apoptosis and autophagy in hepatocellular carcinoma are unclear. Our goal is to determine the internal molecular mechanism of the interaction between SK and PYCR1 and its role in the occurrence and development of liver cancer. The CCK8 assay, wound healing assay, and transwell assays show that SK and siPYCR1(gene silence PYCR1) inhibited the malignant phenotype of HCC cells, including cell viability, colony formation, migration, and invasion, respectively. The flow cytometry assays and immunofluorescence show that SK and siPYCR1 activated apoptosis and autophagy, respectively. SK induces apoptosis and autophagy in a dose-dependent manner. In addition, HCC cells were transfected with small interference fragment PYCR1 siRNA to construct siPYCR1 and SK single treatment group and co-treatment group to verify the interaction between SK and PYCR1. The Western blot identified that PI3K/Akt/mTOR signal pathway protein expression was significantly downregulated in HCC cells treated with SK and siPYCR1 together. Collectively, SK may induce apoptosis and autophagy by reducing the expression of PYCR1 and suppressing PI3K/Akt/mTOR. Thus, SK may be a promising antineoplastic drug in Hepatocellular carcinoma (HCC). SK downregulating PYCR1 might supply a theoretical foundation for the potential therapeutic application in hepatocellular carcinoma.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Naftoquinonas , Apoptose , Autofagia , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação para Baixo , Humanos , Neoplasias Hepáticas/metabolismo , Naftoquinonas/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirróis , Pirrolina Carboxilato Redutases/genética , Pirrolina Carboxilato Redutases/metabolismo , Serina-Treonina Quinases TOR/metabolismoRESUMO
PURPOSE: Infected pancreatic necrosis (IPN) is a highly morbid complication of acute necrotising pancreatitis (ANP). Since there is evidence of early-onset immunosuppression in acute pancreatitis, immune enhancement may be a therapeutic option. This trial aimed to evaluate whether early immune-enhancing Thymosin alpha 1 (Tα1) treatment reduces the incidence of IPN in patients with predicted severe ANP. METHODS: We conducted a multicentre, double-blind, randomised, placebo-controlled trial involving ANP patients with an Acute Physiology and Chronic Health Evaluation II (APACHE II) score ≥ 8 and a computed tomography (CT) severity score ≥ 5 admitted within 7 days of the advent of symptoms. Enrolled patients were assigned to receive a subcutaneous injection of Tα1 1.6 mg every 12 h for the first 7 days and 1.6 mg once a day for the subsequent 7 days or matching placebos (normal saline). The primary outcome was the development of IPN during the index admission. RESULTS: A total of 508 patients were randomised, of whom 254 were assigned to receive Tα1 and 254 placebo. The vast majority of the participants required admission to the intensive care unit (ICU) (479/508, 94.3%). During the index admission, 40/254(15.7%) patients in the Tα1 group developed IPN compared with 46/254 patients (18.1%) in the placebo group (difference -2.4% [95% CI - 7.4 to 5.1%]; p = 0.48). The results were similar across four predefined subgroups. There was no difference in other major complications, including new-onset organ failure (10.6% vs. 15%), bleeding (6.3% vs. 3.5%), and gastrointestinal fistula (2% vs. 2.4%). CONCLUSION: The immune-enhancing Tα1 treatment of patients with predicted severe ANP did not reduce the incidence of IPN during the index admission.
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Pancreatite Necrosante Aguda , Humanos , Doença Aguda , Método Duplo-Cego , Pancreatite Necrosante Aguda/complicações , Pancreatite Necrosante Aguda/diagnóstico por imagem , Resultado do TratamentoRESUMO
INTRODUCTION: Infected pancreatic necrosis (IPN) is an important complication of acute pancreatitis (AP). Absolute lymphocyte count (ALC) was reported to be associated with immunosuppression and the development of IPN. The aim of this study was to describe the trajectory of ALC during the early phase of AP and assess its association with IPN. METHODS: We retrospectively screened patients with AP admitted to our center between January 2016 and July 2019. The ALC levels for the first 7 days after admission were collected. Group-based trajectory modeling was performed to detect the trajectories. Cox proportional hazards regression model was adopted to identify potential risk factors of IPN. RESULTS: Overall, 292 patients were enrolled for analysis. A triple-group trajectory model was developed, assigning 116 patients to the low-level ALC group, 133 to the medium-level ALC group, and 43 to the high-level ALC group. There was no overall significant difference regarding the incidence of IPN among the 3 groups (P = 0.066). In pairwise comparison, patients in the low-level ALC group had significantly higher incidence of IPN than those in the high-level ALC group (hazard ratio: 3.50; 95% confidence interval: 1.22-10.00, P = 0.020). Length of hospital stay and intensive care unit stay differed significantly among patients with different trajectories (P = 0.042 and 0.033, respectively). DISCUSSION: Despite the fact that the trajectories of ALC is overall insignificant for the development of IPN, patients with persistent low ALC trajectories during the early phase of AP are more likely to develop IPN when compared with patients with high ALC trajectories.
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Contagem de Linfócitos , Pancreatite Necrosante Aguda/imunologia , Pancreatite Necrosante Aguda/patologia , Pancreatite/imunologia , Pancreatite/patologia , Adulto , Cuidados Críticos , Progressão da Doença , Feminino , Humanos , Hospedeiro Imunocomprometido , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de RiscoRESUMO
AIM: Coinfecting bacterial pathogens are a major cause of morbidity and mortality in influenza. However, there remains a paucity of literature on the magnitude of coinfection in influenza patients. METHOD: A systematic search of MeSH, Cochrane Library, Web of Science, SCOPUS, EMBASE, and PubMed was performed. Studies of humans in which all individuals had laboratory confirmed influenza, and all individuals were tested for an array of common bacterial species, met inclusion criteria. RESULTS: Twenty-seven studies including 3215 participants met all inclusion criteria. Common etiologies were defined from a subset of eight articles. There was high heterogeneity in the results (I(2) = 95%), with reported coinfection rates ranging from 2% to 65%. Although only a subset of papers were responsible for observed heterogeneity, subanalyses and meta-regression analysis found no study characteristic that was significantly associated with coinfection. The most common coinfecting species were Streptococcus pneumoniae and Staphylococcus aureus, which accounted for 35% (95% CI, 14%-56%) and 28% (95% CI, 16%-40%) of infections, respectively; a wide range of other pathogens caused the remaining infections. An assessment of bias suggested that lack of small-study publications may have biased the results. CONCLUSIONS: The frequency of coinfection in the published studies included in this review suggests that although providers should consider possible bacterial coinfection in all patients hospitalized with influenza, they should not assume all patients are coinfected and be sure to properly treat underlying viral processes. Further, high heterogeneity suggests additional large-scale studies are needed to better understand the etiology of influenza bacterial coinfection.
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Coinfecção/epidemiologia , Influenza Humana/epidemiologia , Infecções Pneumocócicas/epidemiologia , Infecções Estafilocócicas/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Coinfecção/microbiologia , Coinfecção/virologia , Farmacorresistência Bacteriana , Feminino , Hospitalização , Humanos , Lactente , Recém-Nascido , Influenza Humana/virologia , Masculino , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Pessoa de Meia-Idade , Infecções Pneumocócicas/microbiologia , Infecções Estafilocócicas/microbiologia , Streptococcus pneumoniae/isolamento & purificação , Adulto JovemRESUMO
The second messenger c-di-GMP is implicated in regulation of various aspects of the lifestyles and virulence of Gram-negative bacteria. Cyclic di-GMP is formed by diguanylate cyclases with a GGDEF domain and degraded by phosphodiesterases with either an EAL or HD-GYP domain. Proteins with tandem GGDEF-EAL domains occur in many bacteria, where they may be involved in c-di-GMP turnover or act as enzymatically-inactive c-di-GMP effectors. Here, we report a systematic study of the regulatory action of the eleven GGDEF-EAL proteins in Xanthomonas oryzae pv. oryzicola, an important rice pathogen causing bacterial leaf streak. Mutational analysis revealed that XOC_2335 and XOC_2393 positively regulate bacterial swimming motility, while XOC_2102, XOC_2393 and XOC_4190 negatively control sliding motility. The ΔXOC_2335/XOC_2393 mutant that had a higher intracellular c-di-GMP level than the wild type and the ΔXOC_4190 mutant exhibited reduced virulence to rice after pressure inoculation. In vitro purified XOC_4190 and XOC_2102 have little or no diguanylate cyclase or phosphodiesterase activity, which is consistent with unaltered c-di-GMP concentration in ΔXOC_4190. Nevertheless, both proteins can bind to c-di-GMP with high affinity, indicating a potential role as c-di-GMP effectors. Overall our findings advance understanding of c-di-GMP signaling and its links to virulence in an important rice pathogen.
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Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Análise Mutacional de DNA , Xanthomonas/patogenicidade , Proteínas de Bactérias/química , GMP Cíclico/análogos & derivados , GMP Cíclico/metabolismo , Regulação Bacteriana da Expressão Gênica , Oryza/microbiologia , Estrutura Terciária de Proteína , Transdução de Sinais , Virulência , Xanthomonas/metabolismo , Xanthomonas/fisiologiaRESUMO
Bacterial leaf streak caused by Xanthomonas oryzae pv. oryzicola (Xoc) is one of the most important diseases in rice. However, little is known about the pathogenicity mechanisms of Xoc. Here we have investigated the function of three HD-GYP domain regulatory proteins in biofilm formation, the synthesis of virulence factors and virulence of Xoc. Deletion of rpfG resulted in altered production of extracellular polysaccharides (EPS), abolished virulence on rice and enhanced biofilm formation, but had little effect on the secretion of proteases and motility. In contrast, mutational analysis showed that the other two HD-GYP domain proteins had no effect on virulence factor synthesis and tested phenotypes. Mutation of rpfG led to up-regulation of the type III secretion system and altered expression of three putative glycosyltransferase genes gumD, pgaC and xagB, which are part of operons directing the synthesis of different extracellular polysaccharides. The pgaABCD and xagABCD operons were greatly up-regulated in the Xoc ΔrpfG mutant, whereas the expression of the gum genes was unaltered or slightly enhanced. The elevated biofilm formation of the Xoc ΔrpfG mutant was dramatically reduced upon deletion of gumD, xagA and xagB, but not when pgaA and pgaC were deleted. Interestingly, only the ΔgumD mutant, among these single gene mutants, exhibits multiple phenotype alterations including reduced biofilm and EPS production and attenuated virulence on rice. These data indicate that RpfG is a global regulator that controls biofilm formation, EPS production and bacterial virulence in Xoc and that both gumD- and xagB-dependent EPS contribute to biofilm formation under different conditions.