Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Microb Pathog ; 189: 106574, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38354990

RESUMO

Antibiotics play an important role in the treatment of infectious diseases. Long-term overuse or misuse of antibiotics, however, has triggered the global crisis of antibiotic resistance, bringing challenges to treating clinical infection. Bacteriophages (phages) are the viruses infecting bacterial cells. Due to high host specificity, high bactericidal activity, and good biosafety, phages have been used as natural alternative antibacterial agents to fight against multiple drug-resistant bacteria. Enterococcus faecalis is the main species detected in secondary persistent infection caused by failure of root canal therapy. Due to strong tolerance and the formation of biofilm, E. faecalis can survive the changes in pH, temperature, and osmotic pressure in the mouth and thus is one of the main causes of periapical lesions. This paper summarizes the advantages of phage therapy, its applications in treating oral diseases caused by E. faecalis infections, and the challenges it faces. It offers a new perspective on phage therapy in oral diseases.


Assuntos
Infecções Bacterianas , Bacteriófagos , Doenças da Boca , Terapia por Fagos , Humanos , Enterococcus faecalis , Antibacterianos/uso terapêutico
2.
Microb Pathog ; 192: 106689, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38750777

RESUMO

Enterococcus faecalis is the primary species detected in cases of secondary persistent infection resulting from root canal therapy failure. Due to the overuse of antibacterial agents, E. faecalis has developed resistance to these drugs, making it challenging to treat clinical diseases caused by E. faecalis infection. Therefore, there is an urgent need to explore new alternative drugs for treating E. faecalis infections. We aimed to clone and express the genes of phage endolysins, purify the recombinant proteins, and analyze their antibacterial activity, lysis profile, and ability to remove biofilm. The crude enzyme of phage endolysin pEF51 (0.715 mg/mL), derived from phage PEf771 infecting E. faecalis, exhibited superior bacterial inhibitory activity and a broader bactericidal spectrum than its parental phage PEf771. Furthermore, pEF51 demonstrated high efficacy in eliminating E. faecalis biofilm. Therapeutic results of the infected Sprague-Dawley (SD) rat model indicated that among 10 SD rats, only one developed a thoracic peritoneal abscess and splenic peritoneal abscess after 72 h of treatment with pEF51. This suggests that pEF51 could provide protection against E. faecalis infection in SD rats. Based on the 16S rDNA metagenomic data of the intestinal microbial community of SD rats, endolysin pEF51 exerted a certain influence on the diversity of intestinal microorganisms at the genus level. Thus, pEF51 may serve as a promising alternative to antibiotics in the management of E. faecalis infection.


Assuntos
Antibacterianos , Bacteriófagos , Biofilmes , Modelos Animais de Doenças , Endopeptidases , Enterococcus faecalis , Infecções por Bactérias Gram-Positivas , Ratos Sprague-Dawley , Enterococcus faecalis/efeitos dos fármacos , Endopeptidases/farmacologia , Endopeptidases/genética , Endopeptidases/metabolismo , Animais , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Bacteriófagos/genética , Infecções por Bactérias Gram-Positivas/microbiologia , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Antibacterianos/farmacologia , Ratos , RNA Ribossômico 16S/genética , Microbioma Gastrointestinal/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Masculino
3.
Microb Pathog ; 186: 106471, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38048838

RESUMO

Enterococcus faecalis, a conditional pathogenic bacterium, is prevalent in the intestinal, oral, and reproductive tracts of humans and animals, causing a variety of infectious diseases. E. faecalis is the main species detected in secondary persistent infection from root canal therapy failure. Due to the abuse of antibacterial agents, E. faecalis has evolved its resistant ability. Therefore, it is difficult to treat clinical diseases infected by E. faecalis. Exploring new alternative drugs for treating E. faecalis infection is urgent. We cloned and expressed the gene of phage holin, purified the recombinant protein, and analyzed the antibacterial activity, lysis profile, and ability to remove bacterial biofilm. It showed that the crude enzyme of phage holin pEF191 exhibited superior bacterial inhibiting activity and a broader lysis host range compared to the parent phage PEf771. In addition, pEF191 demonstrated high efficacy in eliminating E. faecalis biofilm. The therapeutic results of the Sprague-Dawley (SD) rats model infected showed that pEf191 did not affect SD rats, indicating that pEF191 provided greater protection against E. faecalis infection in SD rats. Based on the 16 S rDNA data of SD rats intestinal microorganism population, holin pEF191 exhibited no impact on the diversity of intestinal microorganisms at the phylum and genus levels and improved the relative abundance of favorable bacteria. Thus, pEF191 may serve as a promising alternative to antibiotics in the management of E. faecalis infection.


Assuntos
Bacteriófagos , Ratos , Animais , Humanos , Bacteriófagos/genética , Enterococcus faecalis/genética , Ratos Sprague-Dawley , Antibacterianos/farmacologia , Biofilmes
4.
Anesth Analg ; 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38315626

RESUMO

BACKGROUND: The effects of oxygenation targets (partial pressure of arterial oxygen [Pao2], arterial oxygen saturation [Sao2]/peripheral oxygen saturation [Spo2], or inspiratory oxygen concentration [Fio2] on clinical outcomes in critically ill patients remains controversial. We reviewed the existing literature to assess the effects of lower and higher oxygenation targets on the mortality rates of critically ill intensive care unit (ICU) patients. METHODS: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science databases were searched from their dates of inception to December 31, 2022, for randomized controlled trials (RCTs) comparing lower and higher oxygenation targets for critically ill patients ≥18 years of age undergoing mechanical ventilation, nasal cannula, oxygen mask, or high-flow oxygen therapy in the ICU. Data extraction was conducted independently, and RoB 2.0 software was used to evaluate the quality of each RCT. A random-effects model was used for the meta-analysis to calculate the relative risk (RR). We used the I2 statistic as a measure of statistical heterogeneity. Certainty of evidence was assessed according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines. RESULTS: We included 12 studies with a total of 7416 patients participating in RCTs. Oxygenation targets were extremely heterogeneous between studies. The meta-analysis found no differences in mortality between lower and higher oxygenation targets for critically ill ICU patients (relative risk [RR], 1.00; 95% confidence interval [CI], 0.93-1.09; moderate certainty). The incidence of serious adverse events (RR, 0.93; 95% CI, 0.85-1.00; high certainty), mechanical ventilation-free days through day 28 (mean difference [MD], -0.05; 95%CI, -1.23 to 1.13; low certainty), the number of patients requiring renal replacement therapy (RRT) (RR, 0.96; 95% CI, 0.84-1.10; low certainty), and ICU length of stay (MD, 1.05; 95% CI, -0.04 to 2.13; very low certainty) also did not differ among patients with lower or higher oxygenation targets. CONCLUSIONS: Critically ill ICU patients ≥18 years of age managed with lower and higher oxygenation targets did not differ in terms of mortality, RRT need, mechanical ventilation-free days through day 28, or ICU length of stay. However, due to considerable heterogeneity between specific targets in individual studies, no conclusion can be drawn regarding the effect of oxygenation targets on ICU outcomes.

5.
Environ Sci Technol ; 57(1): 150-159, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36512687

RESUMO

Due to the complexities of the interactions between ammonia, chlor(am)ine, and intermediate species such as ONOOH, the radical formation in breakpoint chlorination and the consequential removal of micropollutants remain largely unexplored. In this study, the dominant generation pathway of HO•, as a primary radical in breakpoint chlorination, was examined, and the generations of HO•, reactive chlorine species (RCS), and reactive nitrogen species (RNS) were quantitatively evaluated. A dissolved oxygen (DO)-independent pathway was verified by 18O labeling and contributed over 90% to HO• generation. The commonly believed pathway, the decomposition of ONOOH involving DO, contributed only 7% to HO• formation in breakpoint chlorination. The chlorine to nitrogen (Cl/N) ratio and pH greatly affected the generations and speciations of the reactive species. An optimum Cl/N mass ratio for HO•, Cl2•-, and RNS generations occurred at the breakpoint (i.e., Cl/N mass ratio = 9), whereas excessive free chlorine shifted the radical speciation toward ClO• at Cl/N mass ratios above the breakpoint. Basic conditions inhibited the generations of HO• and RNS but significantly promoted that of ClO•. These findings improved the fundamental understanding of the radical chemistry of breakpoint chlorination, which can be extended to estimate the degradations of micropollutants of known rate constants toward the reactive species with influences from the Cl/N ratio and pH in real-world applications.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Cloro/química , Halogenação , Radical Hidroxila/química , Nitrogênio/química , Oxigênio , Cloretos , Poluentes Químicos da Água/química , Raios Ultravioleta , Cinética
6.
Environ Sci Technol ; 57(47): 18735-18743, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-37126657

RESUMO

Dichloramine (NHCl2) often coexists with monochloramine (NH2Cl) in reverse osmosis (RO) permeate in potable reuse scenarios when NH2Cl is added upstream of RO for membrane fouling control such that UV photolysis of NHCl2 occurs during the downstream UV/chloramine process. However, the formation of reactive nitrogen species (RNS) and their incorporation into byproducts during the UV/NHCl2 process are largely unknown. This study quantitatively evaluated the generation of RNS in the UV/NHCl2 process and investigated the role of RNS in micropollutant transformation. UV photolysis of NHCl2 produced comparable RNS concentration to that of NH2Cl at the same oxidant dosage (100 µM) at pH 5.5. Under the experimental conditions, the RNS contributed greatly (40.6%) to N,N-diethyl-3-methylbenzamide (DEET) degradation. By using 15N-labeling and mass spectrometry methods, seven nitrogenous byproducts of DEET degradation with the incorporation of nitrogen originating from the RNS were detected. Among these seven byproducts, six were identified to contain a nitro group (-NO2). While the UV/NHCl2 process formed comparable intensities of -NO-containing products to those in the UV/NH2Cl process, the later process formed 3-91% higher intensities of -NO2-containing products. These findings are essential in furthering our understanding of the contribution of the UV/NHCl2 process in potable reuse scenarios.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Espécies Reativas de Nitrogênio , Fotólise , Nitrogênio , DEET , Dióxido de Nitrogênio , Oxirredução , Raios Ultravioleta , Cloraminas , Óxido Nítrico , Cloro
7.
Environ Sci Technol ; 57(47): 18981-18990, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-37226837

RESUMO

Monobromamine (NH2Br) and dibromamine (NHBr2) produced from reactions of hypobromous acid (HOBr) with ammonia can react with phenolic structures of natural organic matter (NOM) to produce disinfection byproducts such as bromoform (CHBr3). The reactivity of NH2Br was controlled by the reaction of the bromoammonium ion (NH3Br+) with phenolate species, with specific rate constants ranging from 6.32 × 102 for 2,4,6-tribromophenol to 1.22 × 108 M-1 s-1 for phenol. Reactions of NHBr2 with phenol and bromophenols were negligible compared to its self-decomposition; rate constants could be determined only with resorcinol for pH > 7. At pH 8.1-8.2, no formation of CHBr3 was observed from the reaction of NH2Br with phenol while the reaction of NH2Br with resorcinol produced a significant concentration of CHBr3. In contrast to NH2Br, a significant amount of CHBr3 produced with an excess of NHBr2 over phenol was explained by the reactions of HOBr produced from NHBr2 decomposition. A comprehensive kinetic model including the formation and decomposition of bromamines and the reactivity of HOBr and NH2Br with phenolic compounds was developed at pH 8.0-8.3. Furthermore, the kinetic model was used to evaluate the significance of the NH2Br and NHBr2 reactions with the phenolic structures of two NOM isolates.


Assuntos
Fenóis , Purificação da Água , Bromatos/química , Fenol/química , Resorcinóis , Cinética
8.
Public Health Nurs ; 40(6): 885-894, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37579051

RESUMO

OBJECTIVE: Fangcang shelter hospital is a form of large temporary hospital developed in China to tackle public health events. Through the case study and analysis of managing a nursing unit in a huge Fangcang shelter hospital transformed from the National Exhibition and Convention Center during the Omicron wave in Shanghai, China between April 9, 2022 and May 24, 2022, this paper aimed to highlight critical implications of public health nurses in health emergencies. DESIGN: A case study was conducted using data collected from a nursing unit with 570 beds. The five characteristics of management were organized as follows: human resource management, establishment and optimization of the core workflow, safety management of high-risk patients, the grid cooperation mechanism with patient volunteers, as well as humanistic nursing. RESULTS: Analysis of the data of the nursing unit indicated close team cooperation, efficient and orderly process scheduling, good outcomes of patients, and the indispensable role of volunteers. CONCLUSION: Practice indicated that nursing unit management in a large Fangcang shelter hospital is important to ensure medical order and efficiency. This practical experience can provide valuable reference and data to support for the nursing management of large-scale public health events, such as infectious disease epidemics.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , SARS-CoV-2 , Hospitais Especializados , Unidades Móveis de Saúde , China/epidemiologia
9.
Appl Microbiol Biotechnol ; 106(5-6): 2121-2131, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35190846

RESUMO

A phage PEf771 that specifically infects and lyses pathogenic Enterococcus faecalis YN771 in patients with refractory periapical periodontitis was used to investigate resistance against E. faecalis infection in vitro and in vivo. PEf771 completely lysed YN771 within 3 h, with a multiplicity of infection of 1. Compared with ten routinely used clinical antibiotics, PEf771 demonstrated the highest bacteriostatic effect within 72 h. The antibacterial effect of PEf771 on extracted teeth within 72 h was better than that of conventional root canal disinfectants such as camphorated phenol, formaldehyde cresol solution, and Ca(OH)2 (P < 0.05) within 72 h. Using E. faecalis, intraperitoneal and periapical infection models were established using Sprague Dawley (SD) rats. The results showed that all SD rats inoculated with 9.6 × 1011 CFU/mL E. faecalis YN771 or 2.9 × 1011 CFU/mL E. faecalis RYN771 died within 8 h. Additionally, all SD rats inoculated with YN771 and treated with antibiotics died within 72 h. Although SD rats inoculated with RYN771 and treated with antibiotics survived for 72 h, the pathological anatomy of these rats showed purulent discharge, numerous pus and blood-filled ascites, and extensive liver abscesses. Notably, YN771 rats treated with PEf771 and RYN771 rats treated with RPEf771 survived for 72 h, and their pathological anatomy showed that the liver, kidneys, intestine, and mesenteries were normal. Computed tomography analysis of SD rats infected with periapical periodontitis showed pathological changes in experimental teeth inoculated with YN771, despite undergoing a normal root canal treatment. Contrastingly, none of the experimental teeth exhibited root periapical inflammation following PEf771 treatment. Hematoxylin and eosin staining revealed a gap between the periodontal ligament and the cementum of experimental teeth, whereas PEf771-treated teeth exhibited normal results. These findings suggested that phage therapy using PEf771 might effectively prevent E. faecalis infection after root canal treatment.Key points• Compared with common clinical antibiotics, PEf771 showed the highest antibacterial.• The liver, kidney, intestine, and mesentery of SD rats treated with PEf771 were normal.• Phage therapy can effectively prevent E. faecalis YN771 and RYN771 infection.


Assuntos
Periodontite Periapical , Terapia por Fagos , Animais , Enterococcus faecalis , Humanos , Periodontite Periapical/microbiologia , Periodontite Periapical/terapia , Ratos , Ratos Sprague-Dawley , Tratamento do Canal Radicular/métodos
10.
BMC Anesthesiol ; 22(1): 330, 2022 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-36309646

RESUMO

OBJECTIVE: This meta-analysis compared the quality of lung collapse and the resultant adverse reactions between the use of double-lumen endotracheal tubes (DLT) and bronchial blockers (BB) in minimally invasive thoracic surgery. METHODS: A search was performed in five bibliographic databases, namely PubMed, Springer, Medline, EMBASE, and Cochrane Library ignoring the original language, which identified five randomized controlled trials (RCTs) published on or before December 31, 2021. These studies were subsequently analyzed. All included studies compared the efficacy and safety of DLT and BB as a lung isolation technique in surgery. The methodological quality of each study was assessed by the Cochrane Collaboration's risk of bias tool. The quality of lung collapse and the malposition rate were adopted as the main outcome indicators. Alternatively, the intubation time and the incidence of postoperative sore throat were adopted as secondary indicators. RESULTS: When either DLT or BB were utilized in minimally invasive thoracic surgery, no differences were observed in the quality of lung collapse (odds ratio [OR], 1.00; 95% confidence interval [CI], 0.63 to 1.58), the intubation time (mean difference [MD], 0.06; 95% CI, -1.02 to 1.14), or the malposition rate (OR, 0.88; 95% CI, 0.37 to 2.06). However, the incidence of postoperative sore throat among patients treated with BB was significantly lower than that among patients treated with DLT (OR, 5.25; 95% CI, 2.55 to 10.75). CONCLUSION: When utilized in minimally invasive thoracic surgery, the quality of lung collapse with DLT was identical to that with BB. However, patients treated with the latter demonstrated a significantly lower incidence of postoperative sore throat.


Assuntos
Ventilação Monopulmonar , Faringite , Atelectasia Pulmonar , Humanos , Cirurgia Torácica Vídeoassistida/efeitos adversos , Cirurgia Torácica Vídeoassistida/métodos , Intubação Intratraqueal/efeitos adversos , Intubação Intratraqueal/métodos , Atelectasia Pulmonar/complicações , Ventilação Monopulmonar/métodos , Faringite/epidemiologia , Faringite/etiologia , Faringite/prevenção & controle
11.
J Cardiothorac Vasc Anesth ; 36(12): 4393-4402, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36155718

RESUMO

OBJECTIVES: To develop and validate a nomogram for predicting postoperative pulmonary infection (PPI) in patients undergoing lung surgery. DESIGN: Single-center retrospective cohort analysis. SETTING: A university-affiliated cancer hospital PARTICIPANTS: A total of 1,501 adult patients who underwent lung surgery from January 2018 to December 2020. INTERVENTIONS: Observation for PPI within 7 days after lung surgery. MEASUREMENTS AND MAIN RESULTS: A complete set of demographics, preoperative variables, and postoperative follow-up data was recorded. The primary outcome was PPI; a total of 125 (8.3%) out of 1,501 patients developed PPI. The variables with p < 0.1 in univariate logistic regression were included in the multivariate regression, and multivariate logistic regression analysis showed that surgical procedure, surgical duration, the inspired fraction of oxygen in one-lung ventilation, and postoperative pain were independent risk factors for PPI. A nomogram based on these factors was constructed in the development cohort (area under the curve: 0.794, 95% CI 0.744-0.845) and validated in the validation cohort (area under the curve: 0.849, 95% CI 0.786-0.912). The calibration slope was 1 in the development and validation cohorts. Decision curve analysis indicated that when the threshold probability was within a range of 0.02-to-0.58 and 0.02-to-0.42 for the development and validation cohorts, respectively, the nomogram model could provide a clinical net benefit. CONCLUSIONS: The authors developed and validated a nomogram for predicting PPI in patients undergoing lung surgery. The prediction model can predict the development of PPI and identify high-risk groups.


Assuntos
Neoplasias Pulmonares , Nomogramas , Adulto , Humanos , Estudos Retrospectivos , Pulmão , Neoplasias Pulmonares/cirurgia , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia
12.
J Environ Sci (China) ; 102: 24-36, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33637249

RESUMO

UV/chlorine process, as an emerging advanced oxidation process (AOP), was effective for removing micro-pollutants via various reactive radicals, but it also led to the changes of natural organic matter (NOM) and formation of disinfection byproducts (DBPs). By using negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS), the transformation of Suwannee River NOM (SRNOM) and the formation of chlorinated DBPs (Cl-DBPs) in the UV/chlorine AOP and subsequent post-chlorination were tracked and compared with dark chlorination. In comparison to dark chlorination, the involvement of ClO•, Cl•, and HO• in the UV/chlorine AOP promoted the transformation of NOM by removing the compounds owning higher aromaticity (AImod) value and DBE (double-bond equivalence)/C ratio and causing the decrease in the proportion of aromatic compounds. Meanwhile, more compounds which contained only C, H, O, N atoms (CHON) were observed after the UV/chlorine AOP compared with dark chlorination via photolysis of organic chloramines or radical reactions. A total of 833 compounds contained C, H, O, Cl atoms (CHOCl) were observed after the UV/chlorine AOP, higher than 789 CHOCl compounds in dark chlorination, and one-chlorine-containing components were the dominant species. The different products from chlorine substitution reactions (SR) and addition reactions (AR) suggested that SR often occurred in the precursors owning higher H/C ratio and AR often occurred in the precursors owning higher aromaticity. Post-chlorination further caused the cleavages of NOM structures into small molecular weight compounds, removed CHON compounds and enhanced the formation of Cl-DBPs. The results provide information about NOM transformation and Cl-DBPs formation at molecular levels in the UV/chlorine AOP.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Cloro/análise , Desinfecção , Halogenação , Espectrometria de Massas , Poluentes Químicos da Água/análise
13.
Environ Sci Technol ; 54(23): 14964-14973, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33179505

RESUMO

The UV/H2O2 process is a promising advanced oxidation process (AOP) for micropollutant abatement in drinking water treatment and water reuse plants. However, during micropollutant degradation by the AOP, dissolved organic matter (DOM) and the disinfection byproduct (DBP) formation potential may also be altered. This study investigated the influence of the UV/H2O2 AOP on the elemental composition and DBP formation potential of two DOM isolates by using ultrahigh-resolution mass spectrometry (UHRMS). After the AOP, 629 new chemical formulas with an increased degree of oxidation and decreased aromaticity were obtained. Such alterations led to the formation of 226 unknown DBPs with decreased aromaticity indices (AImod) in the subsequent 3-day chlorination. Links between the unknown DBPs and the corresponding precursors in DOM were visualized by network computational analysis. The analysis gave three zones in the van Krevelen diagram based on the possibility of the C7-22HnOm formulas located in each zone to link to the corresponding DBPs. A further investigation with two model compounds reconfirmed the hydroxylation and ring cleavage of DOM by HO· attack during the AOP and the influence on DBP formation. These results obtained from UHRMS build the connection between the elemental composition of DOM and the formation potential of DBPs.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Desinfecção , Halogenação , Peróxido de Hidrogênio , Poluentes Químicos da Água/análise
14.
Can J Microbiol ; 66(9): 505-520, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32374181

RESUMO

Enterococcus faecalis is a common pathogen causing refractory periapical periodontitis and secondary intraradicular infections. In this study, E. faecalis YN771 isolated from a re-treated root canal at a stomatology department was used as the host bacterium and was co-cultured with wastewater from the same department and patient samples to isolate a phage that lyses E. faecalis. We studied the biological and genomic characteristics of this phage. Transmission electron microscopy showed that this phage's head is icosahedral in structure, with a head diameter of around 98.4 nm, and a contractile tail of around 228.5 nm in length and a diameter of 17.3 nm. The phage was identified as a member of the Myoviridae family and named PEf771. It is sensitive to proteinase K but resistant to chloroform and Triton X-100. Its lytic cycle is 45 min, burst size is 78, optimal multiplicity of infection is 0.1, lysis spectrum is narrow, and host strain specificity is strong. Its optimal growth temperature is 37 °C, most suitable pH is 6.0, and is sensitive to ultraviolet radiation. Whole-genome sequencing of PEf771 indicated it has a genome size of 151 052 bp, with a GC content of 36.97%, and encodes 197 proteins plus 26 tRNAs. PEf771 is most closely related to E. faecalis phage EFDG1. Phage PEf771 has strong host specificity and lytic ability, so it is important to further characterize this phage and its interaction with E. faecalis.


Assuntos
Enterococcus faecalis/virologia , Genoma Viral/genética , Myoviridae/genética , Bacteriófagos/genética , Bacteriófagos/ultraestrutura , Composição de Bases , Genômica , Especificidade de Hospedeiro , Humanos , Microscopia Eletrônica de Transmissão , Myoviridae/ultraestrutura , Raios Ultravioleta , Sequenciamento Completo do Genoma
15.
Analyst ; 145(1): 177-183, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31729506

RESUMO

Carbon dots (CDs) have broad prospective applications in various fields, and expanding the applications of fluorescent CDs, especially for CDs derived from bacteria, is a major research goal. In this study, novel CDs derived from Escherichia coli BW25113 (WT) were successfully synthesized via a one-step hydrothermal method. Unlike previously developed CDs-E. coli, CDs-WT can be used for microbial imaging of both live and dead cells. We demonstrated the biocompatibility, excellent penetrability, and nontoxic characteristics of CDs-WT for use as fluorescent probes for bioimaging both in vitro and in vivo. Importantly, we provide the first demonstration of CDs-WT distribution in various organs of mice, including the ability to cross the blood-brain barrier and the potential for rapid excretion through the intestines. Additionally, CDs-WT can be instantly utilized as a fluorescent probe for the highly selective and rapid detection of p-nitrophenol (p-NP) by the inner filter effect, with a limit of detection for p-NP of 11 nM, the lowest value reported to date. Hence, our results demonstrate the feasibility of p-NP detection and extend the bio-imaging applications of CDs prepared from bacteria.


Assuntos
Corantes Fluorescentes/química , Nitrofenóis/análise , Pontos Quânticos/química , Animais , Bacillus cereus/metabolismo , Carbono/química , Carbono/toxicidade , Linhagem Celular Tumoral , Escherichia coli/química , Corantes Fluorescentes/toxicidade , Humanos , Limite de Detecção , Masculino , Camundongos Endogâmicos BALB C , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Nitrofenóis/metabolismo , Pontos Quânticos/toxicidade , Saccharomyces cerevisiae/metabolismo , Distribuição Tecidual
16.
Can J Microbiol ; 64(3): 183-190, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29253355

RESUMO

As the "kidneys of the Earth", wetlands play important roles as biodiversity reservoirs, in water purification, and in flood control. In this study, 2 lytic cold-active bacteriophages, named VW-6S and VW-6B, infecting Pseudomonas fluorescens W-6 cells from the Napahai plateau wetland in China were isolated and characterized. Electron microscopy showed that both VW-6S and VW-6B had an icosahedral head (66.7 and 61.1 nm, respectively) and a long tail (8.3 nm width × 233.3 nm length and 11.1 nm width × 166.7 nm length, respectively). The bacteriophages VW-6S and VW-6B were classified as Siphoviridae and had an approximate genome size of 30-40 kb. The latent and burst periods of VW-6S were 60 and 30 min, whereas those of VW-6B were 30 and 30 min, respectively. The optimal pH values for the bacteriophages VW-6S and VW-6B were 8.0 and 10.0, respectively, and their activity decreased rapidly at temperatures higher than 60 °C. These cold-active bacteriophages provide good materials for further study of cold-adaptation mechanisms and interaction with the host P. fluorescens.


Assuntos
Bacteriófagos/isolamento & purificação , Pseudomonas fluorescens/virologia , Bacteriófagos/genética , Bacteriófagos/ultraestrutura , China , Temperatura Baixa , DNA Viral/genética , Genoma Viral , Especificidade de Hospedeiro , Concentração de Íons de Hidrogênio , Microbiologia da Água , Áreas Alagadas
17.
J Environ Sci (China) ; 58: 146-154, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28774603

RESUMO

The formation of disinfection by-products (DBPs) from the degradation of N,N-diethyl-3-methyl benzoyl amide (DEET) and ibuprofen (IBP) by the ultraviolet irradiation (UV)/chlorine process and subsequent post-chlorination was investigated and compared with the UV/H2O2 process. The pseudo first-order rate constants of the degradation of DEET and IBP by the UV/chlorine process were 2 and 3.1 times higher than those by the UV/H2O2 process, respectively, under the tested conditions. This was due to the significant contributions of both reactive chlorine species (RCS) and hydroxyl radicals (HO) in the UV/chlorine process. Trichloromethane, 1,1,1-trichloro-2-propanone and dichloroacetic acid were the major known DBPs formed after 90% of both DEET and IBP that were degraded by the UV/chlorine process. Their yields increased by over 50% after subsequent 1-day post-chlorination. The detected DBPs after the degradation of DEET and IBP comprised 13.5% and 19.8% of total organic chlorine (TOCl), respectively, and the proportions increased to 19.8% and 33.9% after subsequent chlorination, respectively. In comparison to the UV/H2O2 process accompanied with post-chlorination, the formation of DBPs and TOCl in the UV/chlorine process together with post-chlorination was 5%-63% higher, likely due to the generation of more DBP precursors from the attack of RCS, in addition to HO.


Assuntos
DEET/química , Desinfetantes/análise , Ibuprofeno/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Desinfetantes/química , Desinfecção , Halogenação , Peróxido de Hidrogênio , Radical Hidroxila , Raios Ultravioleta , Poluentes Químicos da Água/química
18.
J BUON ; 22(4): 932-935, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28952209

RESUMO

PURPOSE: To evaluate the significance of hepatic functional reserve for the operation of liver cancer complicated with cirrhosis. METHODS: Fifty-six patients suffering from liver cancer complicated with cirrhosis were divided into three levels, A, B and C, according to Child-Pugh grading system. Based on indocyanine green retention rate at 15 min (ICGR15) value, patients were divided into three intervals, ≤15%, 15-25% and ≥25%. According to the existence of complications, patients were divided into the complication group and the no complication group. RESULTS: Child-Pugh grading included 50 cases of level A, 45 cases of B and 29 cases of C. ICGR15 value included 47 cases of ≤15% interval, 47 cases of 15-25% and 30 cases of ≥25%. As the IGCR15 value increased, the levels of all indicators were obviously increased. Among the 124 patients, 35 cases (28.23%) suffered complications The median follow-up time was 25.0 months. The survival rate of the complication group was 60.00% (21 cases), significantly lower than that of the no complication group (84.27%). Child-Pugh grading of the complication group included 4 cases of level A, 12 cases of B and 19 cases of C. ICGR15 value included 15 cases of 15~25% interval and 20 cases of ≥25%. CONCLUSION: Child-Pugh grading and ICGR15 value can both reflect hepatic functional reserve and are of great clinical significance for complication and survival. There is a fairly good relevance between ICGR15 and levels of AFP, ALT and indicators of liver fibrosis.


Assuntos
Fibrose/etiologia , Testes de Função Hepática/métodos , Neoplasias Hepáticas/complicações , Fígado/patologia , Feminino , Fibrose/patologia , Humanos , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
19.
J Ultrasound Med ; 34(7): 1245-51, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26112627

RESUMO

OBJECTIVES: The management of nodules with nondiagnostic or indeterminate fine-needle aspiration cytologic findings remains challenging. This study evaluated the clinical differences, conventional sonographic findings, elastographic findings, and cytologic findings for predicting thyroid malignancy. METHODS: A total of 167 patients with a nondiagnostic or indeterminate thyroid fine-needle aspiration cytologic findings were enrolled in this study. The clinicopathologic and sonographic data from the patients were analyzed retrospectively to determine the independent predictive factors for thyroid malignancy. Then a scoring system was designed on the basis of statistically significant predictors. RESULTS: Fine-needle aspiration cytologic findings, Thyroid Imaging Reporting and Data System categorization, and elastographic findings were independent predictive factors for thyroid cancer on multivariate analysis. The index points were statistically significant, with a score higher than 3 favoring malignant nodules with sensitivity of 79.37%, specificity of 85.85%, a positive predictive value of 76.9%, and a negative predictive value of 87.3%. CONCLUSIONS: For patients with nondiagnostic or indeterminate fine-needle aspiration cytologic findings, our scoring system for prediction of thyroid malignancy can be another choice. We suggest surgery for nodules with index points higher than 3. For nodules with index points of 3 or lower, observation and regular follow-up are recommended.


Assuntos
Nódulo da Glândula Tireoide/diagnóstico por imagem , Adolescente , Adulto , Idoso , Biópsia por Agulha Fina , Diagnóstico Diferencial , Técnicas de Imagem por Elasticidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/patologia , Adulto Jovem
20.
Stem Cell Rev Rep ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954390

RESUMO

Mesenchymal stem cells (MSCs) have demonstrated considerable potential in tissue repair and the treatment of immune-related diseases, but there are problems with homing efficiency during MSCs transplantation. Exercise, as an intervention, has been shown to have an important impact on the properties of MSCs. This review summarizes the effects of exercise on the properties (including proliferation, apoptosis, differentiation, and homing) of bone marrow-derived MSCs and adipose-derived MSCs. Studies indicated that exercise enhances bone marrow-derived MSCs proliferation, osteogenic differentiation, and homing while reducing adipogenic differentiation. For adipose-derived MSCs, exercise enhances proliferation and reduces adipogenic differentiation. In addition, studies have investigated the therapeutic effects of combined therapy of MSCs transplantation with exercise on diseases of the bone, cardiac, and nervous systems. The combined therapy improves tissue repair by increasing the homing of transplanted MSCs and cytokine secretion (such as neurotrophin 4). Furthermore, MSCs transplantation also has potential for the treatment of obesity. Although the effect is not significant in weight loss, MSCs transplantation shows effects in controlling blood glucose, improving dyslipidemia, reducing inflammation, and improving liver disease. Finally, the potential role of combined MSCs transplantation and exercise therapy in addressing obesity is discussed.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA