Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 223
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
1.
Antimicrob Agents Chemother ; 68(4): e0167823, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38477539

RESUMO

Horizontal gene transfer has been demonstrated to be an important driver for the emergency of multidrug-resistant pathogens. Recently, a transferable gene cluster tmexCD1-toprJ1 of the resistance-nodulation-division (RND) superfamily was identified in the plasmids of animal-derived Klebsiella pneumoniae strains, with a higher efflux capacity for various drugs than the Escherichia coli AcrAB-TolC homolog system. In this study, we focused on the differences in the inner membrane pump of these two systems and identified some key residues that contribute to the robust efflux activity of the TMexCD1 system. With the aid of homologous modeling and molecular docking, eight residues from the proximal binding pocket (PBP) and nine from the distal binding pocket (DBP) were selected and subjected to site-directed mutagenesis. Several of them, such as S134, I139, D181, and A290, were shown to be important for substrate binding in the DBP region, and all residues in PBP and DBP showed certain substrate preferences. Apart from the conservative switch loop (L613-623TMexD1) previously identified in the E. coli AcrB (EcAcrB), a relatively unconservative loop (L665-675TMexD1) at the bottom of PBP was proposed as a critical element for the robust activity of TMexD1, due to variations at sites E669, G670, N673, and S674 compared to EcAcrAB, and the significantly altered efflux activity due to their mutations. The conservation and flexibility of these key factors can contribute to the evolution of the RND efflux pumps and thus serve as potential targets for developing inhibitors to block the widespread of the TMexCD1 system.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Animais , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Antibacterianos/química , Simulação de Acoplamento Molecular , Farmacorresistência Bacteriana Múltipla/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Testes de Sensibilidade Microbiana
2.
Chemistry ; 30(18): e202303919, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38263478

RESUMO

Encouraged by the successful fabrication of C60-GNR (GNR=graphene nanoribbon) single-molecule transistors in experiments, four Fe-containing derived double-layered devices of Fe@C60-GNR are designed by employing different electrode linkages and their transport properties are investigated by using density functional theory (DFT) and nonequilibrium Green's function (NEGF) methods. Regardless of electrode connection, all these devices give rise to a smaller negative differential resistance (NDR) peak at V=0.2 and a higher peak at 1.2 V, suggesting their stable maneuverability as molecular devices and good candidates for developing on(off)-off(on)-on(off) current switches. The macroscopic NDR performance depends on the delocalization character and the crossing mechanism of the frontier orbitals. The peak-to-valley current ratios (Rmax) range from 454 to 2737, determined by the electrode linkage. Such a large Rmax-value is necessary for developing dynamic random-access memory (DRAM) cells. Encapsulating the Fe atom inside C60 not only improves the conductivity but also introduces the spin-polarized transport property. The spin-filtering efficiency (SFE) of almost all devices oscillates up and down in response to the bias voltage, indicating the possibility of designing on(off)-off(on)-on(off) spin switches and up-down spin switches. All these fascinating properties provide an important clue for designing similar molecular devices with multiple functions by trapping magnetic transition metal atoms inside fullerenes.

3.
Int J Med Sci ; 21(3): 474-482, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38250608

RESUMO

Background: The single nucleotide polymorphism (SNP) of Gastrokine-1 (GKN1) is associated with lung cancer but its association with prognosis is not clear. Methods: Genomic DNA was extracted from the blood samples of 888 patients with lung cancer. The association between GKN1 polymorphism rs4254535 and prognostic was analyzed by the Kaplan-Meier (KM) method, Log-rank test, and Cox proportional hazards model. Results: In females and patients diagnosed with late-stage lung cancer, the CC genotype (CC vs TT, adjusted odds ratio [HR] = 0.57, 95% Confidence Interval [CI]: 0.33-0.99, P = 0.045; HR = 0.66, 95% CI: 0.48-0.92, P = 0.014) and recessive CC genotype (CC vs TT + TC, HR = 0.55, 95% CI: 0.32-0.94, P = 0.028; HR = 0.64, 95% CI: 0.47-0.89, P = 0.006) of rs4254535 conferred a better prognosis, compared with the TT and TT + TC genotype. Rs4254535 dominate TC + CC genotype, recessive CC genotype, and C allele who were adenocarcinoma patients had a significantly better prognosis. The recessive CC genotype of non-smoking patients has a better prognosis, compared to the TT + TC genotype. Additionally, in the dominant TT + TC genotype and C allele, no family history patients had a significantly better prognosis, compared to the TT genotype. Conclusion: For lung cancer patients, GKN1 polymorphism rs4254535 may be a protective genetic marker and predicts the prognosis of lung cancer patients.


Assuntos
Neoplasias Pulmonares , Hormônios Peptídicos , Feminino , Humanos , Prognóstico , Neoplasias Pulmonares/genética , Genótipo , Polimorfismo de Nucleotídeo Único/genética , China
4.
Respiration ; 103(3): 155-165, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38382489

RESUMO

INTRODUCTION: Targeting the parasympathetic nervous system innervating the airway with pharmacologic products has been proved to improve the clinical outcomes of severe asthma. Bronchial cryo-denervation (BCD) is a novel non-pharmacologic treatment for severe asthma using an endobronchial cryo-balloon administered via bronchoscopy to denervate parasympathetic pulmonary nerves. Preclinical studies have demonstrated that BCD significantly disrupted vagal innervation in the lung. METHODS: A total of 15 patients with severe asthma were enrolled in this prospective, single-center pilot study. Patients underwent bifurcated BCD treatment at a 30-day interval after baseline assessment. Follow-up through 12 months included assessment of adverse events, technical feasibility, and changes in pulmonary function; asthma control questionnaire-7 (ACQ-7); and asthma control test (ACT). RESULTS: BCD was performed on all 15 severe asthma patients, with technical feasibility of 96.7%. There were no device-related and 2 procedure-related serious adverse events through 12 months, which resolved without sequelae. The most frequent nonserious procedure-related adverse event was increased cough in 60% (9 of 15) patients. Pulmonary function remained unchanged, and significant improvements from baseline ACQ-7 (mean, -1.19, p = 0.0032) and ACT (mean, 3.18, p = 0.0011) scores were observed since the first month's follow-up after a single lung airway treatment, with similar trends till the end of the 12-month follow-up. CONCLUSION: This study provides the first clinical evidence of the safety, feasibility, and initial efficacy of BCD in patients with severe asthma.

5.
BMC Emerg Med ; 24(1): 7, 2024 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-38185679

RESUMO

INTRODUCTION: Focused assessment with sonography for trauma helps detect abdominal free fluid. Prehospital ultrasound scanning is also important because the early diagnosis of hemoperitoneum may reduce the time to definitive treatment in the hospital. This study investigated whether prehospital ultrasound scanning can help detect abdominal free fluid. MATERIALS AND METHODS: In this systematic review, relevant databases were searched for studies investigating prehospital ultrasound examinations for abdominal free fluid in trauma patients. The prehospital ultrasound results were compared with computed tomography, surgery, or hospital ultrasound examination data. The pooled sensitivity and specificity values were analyzed using forest plots. The overall predictive power was calculated by the summary receiver operating characteristic curve. The quality of the included studies was assessed using the quality assessment of diagnostic accuracy studies tool. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was performed to assess the certainty of evidence. RESULT: This meta-analysis comprised six studies that included 1356 patients. The pooled sensitivity and specificity values were 0.596 (95% confidence interval [CI] = 0.345-0.822) and 0.970 (95% CI = 0.953-0.983), respectively. The pooled area under the summary receiver operating characteristic curve was 0.998. The quality assessment tool showed favorable results. In the GRADE analysis, the quality of evidence was very low for sensitivity and high for specificity when prehospital ultrasound was used for hemoperitoneum diagnosis. CONCLUSION: The specificity of abdominal free fluid detection using prehospital ultrasound examinations in trauma patients was very high.


Assuntos
Serviços Médicos de Emergência , Hemoperitônio , Humanos , Abdome/diagnóstico por imagem , Hemoperitônio/diagnóstico por imagem , Ultrassonografia
6.
Mol Microbiol ; 118(3): 244-257, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35852922

RESUMO

Sodium-proton (Na+ /H+ ) antiporters from the ion transporter (IT) superfamily play a vital role in controlling the pH and electrolyte homeostasis. However, very limited information regarding their structural functions is available to date. In this study, the structural model of the NhaD antiporter was proposed as a typical hairpin structure of IT proteins, with two symmetrically conserved scaffold domains that frame the core substrate-binding sites, and four motifs were identified. Furthermore, 25 conserved sites involving these domains were subjected to site-directed mutagenesis, and all mutations resulted in an impact on transport abilities. In particular, as candidates for Na+ -binding sites, D166 and D405 mutations at hairpin discontinuities were detrimental to transport activities and were found to induce pronounced conformational changes using fluorescence resonance energy transfer (FRET) assays. In addition, as observed in the NhaA structure, some charged residues, for example, E64, E65, R454, and R464, are predicted to be involved in the net charge switch of NhaD activation, by collectively form a "pH sensor" at the entrance of the cytoplasmic funnel. Mutations encompassing these residues were detrimental to the transport activity of NhaD or lost the capacity to respond to pH signals and trigger conformational changes for Na+ translocation.


Assuntos
Antiporters , Proteínas de Escherichia coli , Sequência de Aminoácidos , Antiporters/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Escherichia coli/metabolismo , Concentração de Íons de Hidrogênio , Prótons , Sódio/metabolismo , Trocadores de Sódio-Hidrogênio/química , Trocadores de Sódio-Hidrogênio/genética , Trocadores de Sódio-Hidrogênio/metabolismo
7.
FASEB J ; 36(12): e22659, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36394534

RESUMO

The arsenical resistance-3 (ACR3) family constitutes the most common pathway that confers high-level resistance to toxic metalloids in various microorganisms and lower plants. Based on the structural model constructed by AlphaFold2, the Acr3 antiporter from Bacillus subtilis (Acr3Bs ) exhibits a typical NhaA structure fold, with two discontinuous helices of transmembrane (TM) segments, TM4 and TM9, interacting with each other and forming an X-shaped structure. As the structural information available for these important arsenite-efflux pumps is limited, we investigated the evolutionary conservation among 300 homolog sequences and identified three conserved motifs in both the discontinuous helices and TM5. Through site-directed mutagenesis, microscale thermophoresis (MST), and fluorescence resonance energy transfer (FRET) analyses, the identified Motif C in TM9 was found to be a critical element for substrate binding, in which N292 and E295 are involved in substrate coordination, while R118 in TM4 and E322 in TM10 is responsible for structural stabilization. In addition, the highly conserved residues on Motif B of TM5 are potentially key factors in the protonation/deprotonation process. These consensus motifs and residues are essential for metalloid compound translocation of Acr3 antiporters, by framing the core domain and the typical X-shaped of NhaA fold.


Assuntos
Antiporters , Arsenitos , Antiporters/genética , Antiporters/metabolismo , Arsenitos/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Estrutura Secundária de Proteína
8.
Pak J Med Sci ; 39(2): 404-408, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36950407

RESUMO

Objectives: To evaluate the clinical effects of chemotherapy combined with immunotherapy in patients with advanced non-small-cell lung cancer (NSCLC) and the effect on their nutritional status and immune function. Methods: Total 120 patients with advanced NSCLC admitted to Affiliated Hospital of Hebei University from May 2019 to October 2021 were randomly divided into two groups (n= 60, respectively). Patients in the control group were treated by chemotherapy with cisplatin-paclitaxel (TP) alone: 120 mg/m2 paclitaxel was used on d1; and 25mg/m2 cisplatin (CDDP) was used for more than two hour, once every 14 days, for three consecutive three cycles. Patients in the study group were additionally given 200 mg sindilizumab by intravenous drip, once every three weeks. The contrastive analysis of clinical effects, the incidence of adverse reactions, improvement of the nutrient index and the changes in levels of CD3+, CD4+, CD8+, and CD4+/CD8+ in T-lymphocyte subsets was performed between the two groups. Result: The overall response rate (ORR) was 80% and 61% in the study group and the control group, respectively; and the difference was statistically significant (p=0.03); the contrast analysis of the incidence of post-treatment adverse drug reactions (ADRs) in patients in the two groups suggested that the incidence of adverse reactions was 33.3% and 45% in the study group and the control group, respectively; and the difference was not statistically significant (p=0.19). After the treatment, the improvement of hemoglobin, albumin, serum iron and ferritin levels in the study group was more significant than that in the control group; and the difference was statistically significant (p < 0.05). After the treatment, the levels of CD3+, CD4+ and CD4+/CD8+ in the study group were much higher than those in the control group; and the difference was statistically significant (p < 0.05). Conclusion: Chemotherapy combined with immunotherapy is effective in treating patients with advanced NSCLC without increasing the incidence of adverse reactions, and can significantly improve their nutritional status and T-lymphocyte function. This therapeutic regimen is of much higher clinical value than the chemotherapy-only regimen.

9.
Mol Biol Evol ; 38(11): 4867-4883, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34320652

RESUMO

True sea snakes (Hydrophiini) are among the last and most successful clades of vertebrates that show secondary marine adaptation, exhibiting diverse phenotypic traits and lethal venom systems. To better understand their evolution, we generated the first chromosome-level genomes of two representative Hydrophiini snakes, Hydrophis cyanocinctus and H. curtus. Through comparative genomics we identified a great expansion of the underwater olfaction-related V2R gene family, consisting of more than 1,000 copies in both snakes. A series of chromosome rearrangements and genomic structural variations were recognized, including large inversions longer than 30 megabase (Mb) on sex chromosomes which potentially affect key functional genes associated with differentiated phenotypes between the two species. By integrating multiomics we found a significant loss of the major weapon for elapid predation, three-finger toxin genes, which displayed a dosage effect in H. curtus. These genetic changes may imply mechanisms that drove the divergent evolution of adaptive traits including prey preferences between the two closely related snakes. Our reference-quality sea snake genomes also enrich the repositories for addressing important issues on the evolution of marine tetrapods, and provide a resource for discovering marine-derived biological products.


Assuntos
Hydrophiidae , Animais , Venenos Elapídicos/genética , Evolução Molecular , Genoma , Hydrophiidae/genética , Fenótipo
10.
J Antimicrob Chemother ; 77(3): 675-681, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-34910133

RESUMO

OBJECTIVES: The NorA antiporter of Staphylococcus aureus belongs to the major facilitator superfamily (MFS) and extrudes various kinds of drugs. With no structure available for this drug efflux pump, the aim of this study was to explore its important structural elements that contribute to substrate binding and drug transport. METHODS: Evolutionary conservative analyses were conducted on different compilations of NorA homologues to identify conservative motifs and residues. Site-directed mutations were constructed to verify the functional changes in NorA efflux capacities and the conformational changes were further measured by fluorescence resonance energy transfer (FRET) and microscale thermophoresis (MST) analysis. RESULTS: Besides Motif-A, Motif-B and Motif-C that were reported previously in MFS proteins, two other motifs, Motif-1 and Motif-2, were identified in NorA. Site-directed mutations of Motif-1 and Motif-2 as well as 11 predicted binding sites all caused remarkable reductions in drug resistance and efflux activity. Among these, mutant F16A/E222A/F303A/D307A showed an altered binding affinity for tetraphenylphosphonium chloride when measured by MST and Motif-1 mutant G114D/A117E/D118G/V119I and Motif-2 mutant Q325E/G326E/A328E/G330E displayed obvious conformational alterations when compared with the wild-type NorA in the FRET signal spectra. CONCLUSIONS: The NorA structure agrees well with the typical structures of MFS proteins, with two newly identified motifs (Motif-1 and Motif-2) that are critical to the structural stability of NorA, and sites F16, E222, F303 and D307 are involved in substrate binding.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Antibacterianos/metabolismo , Proteínas de Bactérias/metabolismo , Humanos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo
11.
Cell Immunol ; 378: 104558, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35717749

RESUMO

The role of Dectin-2 (gene symbol, Clec4n) in house dust mite (HDM) induced Th2 immune response and the exact mechanism remains controversial. In this study, we illustrated that, Clec4n-/- mice had decreased Th2 immune response following HDM challenge, which may ascribe to dramatically reduced type 2 conventional dendritic cells (cDC2s) in lung of Clec4n-/- mice, as cDC2s from lung of Clec4n-/- mice after challenging had less ability to induce Th2 response with decreased production of IL-4/IL-13. Further in vitro experiments showed the activation of Clec4n-/--BMDCs significantly decreased after HDM stimulation accompanied with decreased activation of Syk-NF-κB and Syk-JNK signal pathway. Importantly, Dectin-2 expression in PBMCs from asthmatic patients was significantly higher than that in healthy controls. Taken together, these results demonstrated that Dectin-2 could promote cDC2s activation in lung, which polarizes Th2 immune response outlining a novel mechanism of asthma development.


Assuntos
Asma , Pyroglyphidae , Animais , Citocinas/metabolismo , Células Dendríticas , Dermatophagoides pteronyssinus , Modelos Animais de Doenças , Lectinas Tipo C , Pulmão , Camundongos , Camundongos Knockout , Células Th2
12.
J Asthma ; 59(2): 288-296, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33263457

RESUMO

OBJECTIVE: Depression is a common co-morbidity in asthma, worsening asthma control and impairing quality of life. Previous studies have reported a higher risk of cognitive deficit in depression, yet little research has focused on the level of cognition in asthmatic patients with depression. Evidence shows that inflammation may play an important role in both asthma and depression. Cerebral white matter injury, possibly induced by inflammation, has been associated with depression. This study assesses cognitive function in patients with asthma and a depression comorbidity, compared to patients with asthma only or depression only. METHODS: Four groups were studied: Asthma comorbid Depression group (A + D, n = 26), Depression group (D, n = 25), Asthma group (A, n = 33) and Normal controls (N, n = 28). Cognitive function was evaluated using Montreal Cognitive Assessment (MoCA). Inflammatory cytokines were measured, including interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), high-mobility group box 1(HMGB1) and Netrin-1. Cerebral white matter injury was assessed by serum myelin basic protein (MBP) and myelin oligodendrocyte glycoprotein (MOG), and their correlations with cognitive performance were calculated. RESULTS: A + D group showed the highest incidence of cognitive deficit, with the cognitive domain particularly affected. Compared to N group, serum levels of IL-6, HMGB1, Netrin-1, MBP and MOG were significantly elevated in A + D group. MOG level negatively correlated with the MoCA score. CONCLUSION: Patients with comorbidities presented with more severe cognitive deficits and higher levels of inflammatory cytokines. Cerebral white matter injury may account for the cognitive deficit in patients and MOG could be a potential biomarker for this process.


Assuntos
Asma , Proteína HMGB1 , Substância Branca , Asma/complicações , Asma/epidemiologia , Cognição , Citocinas/metabolismo , Depressão/complicações , Depressão/epidemiologia , Proteína HMGB1/metabolismo , Humanos , Inflamação , Interleucina-6 , Netrina-1/metabolismo , Qualidade de Vida , Substância Branca/diagnóstico por imagem , Substância Branca/metabolismo
13.
BMC Pulm Med ; 22(1): 162, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35477385

RESUMO

OBJECTIVES: The aim of this study was to explore risk factors for the prognosis of lung cancer with simple brain metastasis (LCSBM) patients and to establish a prognostic predictive nomogram for LCSBM patients. MATERIALS AND METHODS: Three thousand eight hundred and six cases of LCSBM were extracted from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015 using SEER Stat 8.3.5. Lung cancer patients only had brain metastasis with no other organ metastasis were defined as LCSBM patients. Prognostic factors of LCSBM were analyzed with log-rank method and Cox proportional hazards model. Independent risk and protective prognostic factors were used to construct nomogram with accelerated failure time model. C-index was used to evaluate the prediction effect of nomogram. RESULTS AND CONCLUSION: The younger patients (18-65 years old) accounted for 54.41%, while patients aged over 65 accounted for 45.59%.The ratio of male: female was 1:1. Lung cancer in the main bronchus, upper lobe, middle lobe and lower lobe were accounted for 4.91%, 62.80%, 4.47% and 27.82% respectively; and adenocarcinoma accounted for 57.83% of all lung cancer types. The overall median survival time was 12.2 months. Survival rates for 1-, 3- and 5-years were 28.2%, 8.7% and 4.7% respectively. We found female (HR = 0.81, 95% CI 0.75-0.87), the married (HR = 0.80; 95% CI 0.75-0.86), the White (HR = 0.90, 95% CI 0.84-0.95) and primary site (HR = 0.45, 95% CI 0.39-0.52) were independent protective factors while higher age (HR = 1.51, 95% CI 1.40-1.62), advanced grade (HR = 1.19, 95% CI 1.12-1.25) and advanced T stage (HR = 1.09, 95% CI 1.05-1.13) were independent risk prognostic factors affecting the survival of LCSBM patients. We constructed the nomogram with above independent factors, and the C-index value was 0.634 (95% CI 0.622-0.646). We developed a nomogram with seven significant LCSBM independent prognostic factors to provide prognosis prediction.


Assuntos
Neoplasias Encefálicas , Neoplasias Pulmonares , Adolescente , Adulto , Idoso , Neoplasias Encefálicas/secundário , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Nomogramas , Prognóstico , Programa de SEER , Adulto Jovem
14.
Allergol Immunopathol (Madr) ; 50(1): 9-16, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34873891

RESUMO

Bronchial asthma is a common chronic airway disease, and long-term management of asthma is the focus and challenge of clinical treatment. Glucocorticoids are often used as the first choice for the treatment of asthma. However, the occurrence of hormone dependence, hormone resistance, and local and systemic adverse reactions caused by hormone application also creates problems for the treatment of asthma. Finding new, safe, and effective therapeutic drugs is an important research direction at present. Icariin is an effective ingredient of the traditional Chinese medicine, Epimedium. It has various biological attributes such as anti-inflammatory and antioxidative activities, and immune regulation. It has high safety and a wide range of clinical applications. Icariin has the characteristics of multitargeted intervention in the treatment of asthma. Here, we review the specific mechanisms of icariin in treating asthma, and icariin is considered a novel therapy in controlling asthma; however, the mechanism is still worth further investigation.


Assuntos
Asma , Medicina Tradicional Chinesa , Asma/tratamento farmacológico , Flavonoides , Hormônios , Humanos , Extratos Vegetais
15.
J Antimicrob Chemother ; 76(6): 1420-1427, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33677568

RESUMO

OBJECTIVES: The NorA efflux pump in Staphylococcus aureus mediates resistance to many fluoroquinolone (FQ) antibiotics. Three norA alleles with high sequence similarity are found in various S. aureus strains exhibiting different FQ resistance profiles. This study aimed to elucidate the underlying molecular basis for the varying efflux activity of these three allelic variations. METHODS: The norA genotypes of 20 S. aureus isolates were analysed. Multiple alignments and conservative analyses were conducted to explore the evolutionary variations. After heterologous expression in Escherichia coli, seven mutants were constructed for MIC tests, efflux activity and conformational change measurements. RESULTS: Three NorA alleles were identified that displayed different FQ MICs and varying efflux activity for ethidium bromide, with the NorAII protein showing the strongest activity. A total of 29 single amino acid polymorphisms were identified by conservative analysis within three allelic peptides, with seven sites densely distributed in the 277-297 region. Mutations of these seven residues in NorAII all significantly impaired drug resistance and efflux activity, and three key mutants showed conformational changes in fluorescence resonance energy transfer (FRET) analysis. CONCLUSIONS: Evolutionary variations of the 277-297 region could be a major explanation for the functional difference of three norA alleles and serve as a potential target for the development of novel NorA inhibitors.


Assuntos
Proteínas Associadas à Resistência a Múltiplos Medicamentos , Staphylococcus aureus , Alelos , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Testes de Sensibilidade Microbiana , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo
16.
Biotechnol Lett ; 43(4): 825-834, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33502660

RESUMO

OBJECTIVES: For the stress from fermenters, downstream processing equipment, and wastewater treatment to be alleviated, lowering salt-dependence in the ectoine synthesis process is of great significance in the moderately halotolerant Halomonas hydrothermalis Y2. RESULTS: In H. hydrothermalis Y2, the σ70- and σ38-controlled promoters of ectA are predicted to be involved in the osmotic regulation of ectoine synthesis. By substituting the ectA promoter with a promoter P265 that identified in the outer membrane pore protein E of H. hydrothermalis Y2, the salt dependence of ectoine synthesis was significantly decreased. In the 500-ml flask containing various NaCl contents, the engineered strain (p/Y2/△ectD/△doeA) showed a remarkably enhanced ability in ectoine synthesis, especially under lower saline stress. After a 36-h fed-batch fermentation in the 1-l fermenter, p/Y2/△ectD/△doeA synthesized 11.5 g ectoine l-1 in the presence of 60 g NaCl-1 l, with a high 0.32 g ectoine l-1 h-1 productivity, a specific productivity of 512.2 mg ectoine per g cell dry weight (CDW)-1, and an excretion ratio of 67 % ectoine. CONCLUSIONS: As no impaired growth was observed in strain p/Y2/△ectD/△doeA while ectoine synthesis was increased, this promoter engineering strategy provides a practical protocol for lowering the salt-dependence of ectoine synthesis in this moderately halotolerant strain.


Assuntos
Diamino Aminoácidos/biossíntese , Proteínas de Bactérias/genética , Técnicas de Cultura Celular por Lotes/métodos , Halomonas/crescimento & desenvolvimento , Proteínas da Membrana Bacteriana Externa/genética , Reatores Biológicos/microbiologia , Meios de Cultura/química , Fermentação , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Engenharia Genética , Halomonas/metabolismo , Regiões Promotoras Genéticas , Cloreto de Sódio/química
17.
Zhongguo Zhong Yao Za Zhi ; 46(17): 4555-4562, 2021 Sep.
Artigo em Zh | MEDLINE | ID: mdl-34581061

RESUMO

To analyze the research hotspots and trends of traditional Chinese medicine(TCM) for neurogenesis with use of CiteSpace 5.7.R3 software. The bibliometrics analysis on the literatures of TCM for neurogenesis from 1987 to 2020 included in the CNKI database was conducted to visualize the number of papers, authors, institutions and keywords. Totally 736 literatures were included and the volume of annual publications showed an upward in volatility. At present, several stable research teams have been formed, which were represented by DING Fei, ZHOU Chong-jian and ZHOU Yong-hong, but the cooperation was not close among the teams. According to the analysis of research institutions, Institute of Diagnostics of Hunan University of Chinese Medicine and Acupuncture Research Center of Tianjin University of Traditional Chinese Medicine produced largest number of literatures. The cooperation among institutions, with universities of TCM and affiliated hospitals as the main research force, was characterized by dominant cooperation among regional institutions and less cross-regional cooperation. Keywords analysis showed that in the field of TCM for neurogenesis, a lot of studies mainly focused on the disease field, treatment and medication, TCM therapy and molecular mechanism. The research on TCM therapy and molecular mechanism for neurogenesis of central nervous system will be the research hotspots in future.


Assuntos
Terapia por Acupuntura , Medicina Tradicional Chinesa , Bibliometria , Bases de Dados Factuais , Neurogênese
18.
BMC Pulm Med ; 20(1): 279, 2020 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-33099324

RESUMO

BACKGROUND: Due to the fact that pulmonary tuberculosis (PTB) is a highly infectious respiratory disease characterized by high herd susceptibility and hard to be treated, this study aimed to search novel effective biomarkers to improve the prognosis and treatment of PTB patients. METHODS: Firstly, bioinformatics analysis was performed to identify PTB-related differentially expressed genes (DEGs) from GEO database, which were then subjected to GO annotation and KEGG pathway enrichment analysis to initially describe their functions. Afterwards, clustering analysis was conducted to identify PTB-related gene clusters and relevant PPI networks were established using the STRING database. RESULTS: Based on the further differential and clustering analyses, 10 DEGs decreased during PTB development were identified and considered as candidate hub genes. Besides, we retrospectively analyzed some relevant studies and found that 7 genes (CCL20, PTGS2, ICAM1, TIMP1, MMP9, CXCL8 and IL6) presented an intimate correlation with PTB development and had the potential serving as biomarkers. CONCLUSIONS: Overall, this study provides a theoretical basis for research on novel biomarkers of PTB, and helps to estimate PTB prognosis as well as probe into targeted molecular treatment.


Assuntos
Biomarcadores/análise , Redes Reguladoras de Genes , Transcriptoma , Tuberculose Pulmonar/genética , Análise por Conglomerados , Biologia Computacional/métodos , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica , Humanos , Mycobacterium tuberculosis , Prognóstico , Estudos Retrospectivos , Tuberculose Pulmonar/microbiologia
19.
Genes Immun ; 20(4): 273-280, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-29915314

RESUMO

To further investigate the relationship between lung cancer and hedgehog interacting protein (HHIP) polymorphisms of chronic obstructive pulmonary disease (COPD) patients, we conducted a case-control study in a Chinese Han population. Six HHIP SNPs with minor allele frequencies >5% (rs1489758, rs1489759, rs10519717, rs13131837, rs1492820, and rs7689420) were analyzed in 1,017 COPD patients (767 males and 246 females) and 430 non-COPD patients. Using logistic regression analysis, we found that rs7689420 was significantly associated with lung cancer in COPD patients in the Chinese Han population (P < 0.001). The recessive allele of rs7689420 was associated with the occurrence of lung cancer in all COPD patients (odds ratios [OR] of 0.609 and 0.424 for the CT and TT genotypes, respectively) as well as in serious COPD patients (OR of 0.403 and 0.305 for CT and TT, respectively). Additionally, rs1489759 and rs3131837 were associated with lung cancer in various genetic models. rs1489758, rs1489759, and rs10519717 were also associated with lung cancer in serious COPD patients. However, none of the SNPs were significantly associated with lung cancer in mild COPD patients or healthy subjects. Therefore, the HHIP SNPs of COPD patients likely play a role in lung cancer pathology in the Chinese Han population.


Assuntos
Proteínas de Transporte/genética , Neoplasias Pulmonares/genética , Glicoproteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único , Doença Pulmonar Obstrutiva Crônica/complicações , Idoso , China , Feminino , Humanos , Neoplasias Pulmonares/epidemiologia , Masculino , Pessoa de Meia-Idade
20.
Int J Colorectal Dis ; 34(1): 113-121, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30368569

RESUMO

PURPOSE: Current clinical guidelines recommended the routine use of adjuvant chemotherapy for locally advanced rectal cancer (LARC) patients. However, the effects of adjuvant chemotherapy in patients with pathological complete response (pCR) after neoadjuvant chemoradiotherapy and radical surgery showed discrepancies in different investigations. METHODS: A systematic review and meta-analysis were conducted using PubMed, Embase and Web of Science databases. All original comparative studies published in English that were related to adjuvant versus non-adjuvant chemotherapy for LARC patients with pCR were included. RESULTS: A total of 6 studies based on 18 centres or databases involving 2948 rectal cancer patients with pCR (adjuvant group = 1324, non-adjuvant group = 1624) were included in our overall analysis. Based on our meta-analysis, LARC patients with pCR who received adjuvant chemotherapy showed a significantly improved overall survival (OS) when compared to patients with observation (HR = 0.65, 95% CI = 0.46-0.90, P = 0.01). In addition, investigations focused on this issue based on the National Cancer Database (NCDB) were systematically reviewed in our current study. Evidence from all three analyses demonstrated that LARC patients with clinical nodal positive disease that achieved pCR might benefit the most from additional adjuvant chemotherapy. CONCLUSION: Our meta-analysis indicated that adjuvant chemotherapy is associated with improved OS in LARC patients with pCR after neoadjuvant chemoradiotherapy and radical surgery.


Assuntos
Quimiorradioterapia , Neoplasias Retais/patologia , Neoplasias Retais/terapia , Quimioterapia Adjuvante , Humanos , Estadiamento de Neoplasias , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA