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1. This study aimed to investigate the protective effects of Gingko biloba extract EGB761 on heat-stressed chicken heart in vivo and its underlying relevance to Hsp70.2. A total of 50 one-day-old female chicks were randomly divided into five groups: control (Con), heat-stress (HS), 0.1% EGB761 plus heat-stress (0.1%EGB+HS), 0.3%EGB761 plus heat-stress (0.3%EGB+HS) and 0.6%EGB761 plus heat-stress (0.6%EGB+HS) groups. After administration of EGB761 for 45 days, the chickens in each group were exposed to a single heat-stress event at 38 ± 1°C for 3 h.3. EGB761 attenuated the abnormal symptoms and pathological scores of myocardium of heat-stressed chickens. Despite a reduction in the transcription and translation of the Hsp70 gene in heat-stressed myocardium, EGB761 induced the expression of Hsp70 in endothelial cells of the microarteries and venules into the blood, and reduced heat-stress damage in vascular endothelial cells.4. Supplementation with EGB761 before heat-stress exposure protected chicken myocardium from damage by increasing serum Hsp70 protein from myocardial cells and cardiac microvascular endothelial cells and protected the microvascular system from adverse injury.
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Pollos , Ginkgo biloba , Animales , Células Endoteliales , Corazón , Respuesta al Choque Térmico , Calor , Miocardio/metabolismo , Extractos VegetalesRESUMEN
Acinetobacter baumannii is a nosocomial pathogen capable of resistance to multiple antimicrobials. The AdeRS two-component system (TCS) is associated with antimicrobial resistance by controlling the AdeABC efflux pump. To elucidate modulation by AdeRS, we made an A. baumannii mutant lacking the AdeRS TCS and characterized it using phenotype microarray (PM) analysis. After disrupting the adeRS operon, lower expression of AdeABC efflux pump was observed in the mutant strain. PM analysis showed that the AdeRS deletion strain and parental strain presented different tolerances to 91 compounds. Tolerance to 54 of the 91 compounds could be restored by complementing the AdeRS deleted strain with a plasmid carrying the adeRS gene. Compared to the parental strain, the AdeRS deletion strain was more sensitive to various inhibitors that target on-protein synthesis and function of cell membrane permeability. Tolerance to phleomycin of the AdeRS deletion strain reduced greatly and was further confirmed with minimum inhibitory concentration (MIC) determination and spot assay. The efflux pump inhibitor, NMP, could reduce phleomycin MIC four-fold at least for 29 (34.8%) of 81 tigecycline-resistant extensively drug-resistant A. baumannii (TGC-resistant XDRAB) clinical isolates. Our results suggested that the AdeRS TCS of A. baumannii was important for both elimination of antibiotics and tolerance to particular compounds.
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Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/fisiología , Farmacorresistencia Bacteriana , Proteínas de Transporte de Membrana/genética , Fenotipo , Infecciones por Acinetobacter/microbiología , Antibacterianos/farmacología , Sinergismo Farmacológico , Orden Génico , Prueba de Complementación Genética , Humanos , Proteínas de Transporte de Membrana/metabolismo , Análisis por Micromatrices , Pruebas de Sensibilidad Microbiana , Operón , Eliminación de SecuenciaRESUMEN
Little is known about the virulence and clinical impact on humans from infection with Anaeroglobus geminates, an anaerobic gram-negative coccus belonging to the family Veillonellaceae. We report the first case of an Anaeroglobus geminates invasive infection in humans characterized by pneumonia complicated with empyema. The pathogen was initially identified as Veillonella spp. by an automatic identification system (Becton-Dickinson and Company, Franklin Lakes, NJ, USA) and definitively identified following 16S ribosomal RNA gene sequence analysis. The patient was cured by surgical decortication and antimicrobial therapy. In this case, the combination of effective antibiotics, surgical intervention, and adequate drainage successfully cured the patient.
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Empiema , Infecciones por Bacterias Gramnegativas , Neumonía Bacteriana , Veillonellaceae , Anciano , ADN Bacteriano/análisis , ADN Bacteriano/genética , Femenino , Humanos , Radiografía Torácica , Veillonellaceae/clasificación , Veillonellaceae/genéticaAsunto(s)
Poroqueratosis/diagnóstico , Piel/patología , Biopsia , Nalgas , Humanos , Masculino , Poroqueratosis/patología , Adulto JovenRESUMEN
Tigecycline (TGC)-resistant extensively drug-resistant Acinetobacter baumannii (XDRAB) is an increasing threat in regard to nosocomial infections. The resistance-nodulation-cell division (RND) efflux pump has played an important role in TGC resistance. In this study, total 81 TGC-resistant XDRAB isolates were analyzed for their responses to the efflux pump inhibitor 1-(1-naphthylmethyl)-piperazine (NMP). We found that NMP could reduce by 4-fold or greater than 4-fold the minimum inhibitory concentration (MIC) of TGC in 45 isolates (55.6 %). After typing with pulsed-field gel electrophoresis (PFGE), group A appeared to be the major cluster with good synergistic response to NMP. Transcripts of the AdeABC efflux pump gene were consistently more correlated with TGC resistance than transcripts of the AdeFGJ or AdeIJK efflux pump genes in these isolates. Of the 81 isolates, the amino acid sequences of AdeR and AdeS were further classified and combined into 31 different codes. Although the dissemination of TGC-resistant XDRAB isolates was genetically diverse in our hospital, their responses to NMP conversion were still strain-dependent. We found that AdeRS combination codes were better than PFGE typing in separating groups of isolates with different sensitivity to NMP conversion.
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Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/efectos de los fármacos , Proteínas Bacterianas/genética , Proteínas de Transporte de Membrana/genética , Minociclina/análogos & derivados , Acinetobacter baumannii/genética , Acinetobacter baumannii/aislamiento & purificación , Acinetobacter baumannii/metabolismo , Antibacterianos/farmacología , Proteínas Bacterianas/antagonistas & inhibidores , Proteínas Bacterianas/metabolismo , Farmacorresistencia Bacteriana Múltiple , Electroforesis en Gel de Campo Pulsado , Humanos , Proteínas de Transporte de Membrana/metabolismo , Pruebas de Sensibilidad Microbiana , Minociclina/farmacología , TigeciclinaRESUMEN
The aim of the present study was to identify the correlation between expression of heat shock protein 47 (Hsp47) and stress injury in heat-stressed myocardial cells and to compare variations in Hsp47 expression in rat myocardial cells exposed to different heat stress for varying periods in vitro and in vivo. Exposure to heat stress at 42°C resulted in similar induction patterns of the heart damage-related enzyme aspartate aminotransferase in the supernatants of H9c2 cells and in the serum of rats. Histological analysis revealed that both H9c2 cells and heart tissues displayed cellular degeneration in response to different periods of heat stress. Hsp47 was constitutively expressed in the cytoplasm of H9c2 cells at all time points during heat stress, which was consistent with observations in heart fibers in vivo. Immunoblotting analysis revealed no significant difference between the expression of Hsp47 in H9c2 cells and heart tissue. However, the expression of hsp47 mRNA in response to heat stress was significantly increased in H9c2 cells at 60 min (P < 0.01) and 100 min (P < 0.01), which was comparable to that at 100 min (P < 0.01) in the rat heart. Thus, Hsp47 was elevated significantly after hyperthermia at the mRNA level but not at the protein level both in vitro and in vivo. The results suggest that Hsp47 turnover may increase during heat stress or that Hsp47 consumption exceeds its production.
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Proteínas del Choque Térmico HSP47/metabolismo , Respuesta al Choque Térmico/genética , Miocitos Cardíacos/metabolismo , Animales , Enzimas/sangre , Enzimas/metabolismo , Femenino , Proteínas del Choque Térmico HSP47/sangre , Proteínas del Choque Térmico HSP47/genética , Trastornos de Estrés por Calor/genética , Trastornos de Estrés por Calor/metabolismo , Trastornos de Estrés por Calor/patología , Masculino , Miocitos Cardíacos/patología , Ratas Sprague-DawleyRESUMEN
To investigate the protective role of Hsp60 against stress damage and its role in the sudden death of stressed animals, changes in the levels of Hsp60 protein and hsp60 mRNA of myocardial cells in vivo and in vitro were studied. In addition, the relationship between Hsp60 expression and heat-induced damage was also studied. Rats were exposed to a temperature of 42° ± 1°C for 0, 20, 40, 60, 80, or 100 min. More than 50% of the rats died suddenly within 100 min. With increasing heat stress duration, hsp60 mRNA levels significantly increased in both in vivo and in vitro rat myocardial cells; however, a similar trend was not observed for Hsp60 protein levels. Although the changes observed in Hsp60 expression in myocardial cells in vitro were inconsistent with those of rat heart tissues in vivo, Hsp60 expression levels were consistent with the histopathological damage observed in myocardial cells both in vivo and in vitro. Differences in Hsp60 expression may reflect the degree of injury sustained by myocardial cells in vivo and in vitro. As a mitochondrial protein, Hsp60 represents a potential biomarker of heat stress, and may protect against heat stress induced myocardial cellular damage both in vivo and in vitro.
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Chaperonina 60/genética , Respuesta al Choque Térmico , Miocardio/metabolismo , Miocardio/patología , Animales , Línea Celular , Chaperonina 60/metabolismo , Regulación de la Expresión Génica , Respuesta al Choque Térmico/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Transcripción GenéticaRESUMEN
We report a memristive switching effect in Pt/CuOx/Si/Pt devices prepared by the rf sputtering technique at room temperature. Differently from other Cu-based metal filament switching systems, a gradual electroforming process, marked by a gradual increase of the device resistance and a gradual decrease of the device capacitance, was observed in the current-voltage and capacitance characteristics. After the gradual electroforming, the devices show a uniform memristive switching behavior. By Auger electron spectroscopy analysis, a model based on the thickness change of the SiOx layer at the CuOx/Si interface and Cu ion migration is proposed for the gradual electroforming and uniform memristive switching, respectively. This work should be meaningful for the preparation of forming-free and homogeneous memristive devices.
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PURPOSE: To investigate the impact of beclin 1 on prognosis of cervical cancer, we determined the expression of beclin 1 in cervical cancer, cervical intraepithelial neoplasia (CIN) and normal cervical tissues. METHODS: A total of 122 cases of cervical cancer, 35 cases with CIN and 31 cases with uterine fibroids were collected at the Cancer Center of Sun Yat University to determine the expression of beclin 1. RESULTS: Beclin 1 positive rate in normal cervical tissues, CIN tissues and cervical cancers was 83.9%, 74.3% and 53.3%, respectively, and it was significantly different between the three groups (p < 0.01). Beclin 1 expression was negatively correlated with cervical cancer differentiation, lymph node metastasis, recurrence and death (p < 0.05). The negative expression is the risk factor affecting overall survival (p < 0.05) and progression-free survival (PFS) (p < 0.05). Multivariate analysis showed that beclin 1 negative expression was an independent risk factor of PFS time. CONCLUSIONS: Beclin 1 may play a role in the occurrence and development of cervical cancer. Beclin 1 positive expression in patients indicates a better prognosis.
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Proteínas Reguladoras de la Apoptosis/metabolismo , Carcinoma de Células Escamosas/metabolismo , Cuello del Útero/metabolismo , Proteínas de la Membrana/metabolismo , Displasia del Cuello del Útero/metabolismo , Neoplasias del Cuello Uterino/metabolismo , Adulto , Autofagia , Beclina-1 , Carcinoma de Células Escamosas/patología , Supervivencia sin Enfermedad , Femenino , Humanos , Estimación de Kaplan-Meier , Análisis Multivariante , Pronóstico , Modelos de Riesgos Proporcionales , Estadísticas no Paramétricas , Neoplasias del Cuello Uterino/patología , Displasia del Cuello del Útero/patologíaRESUMEN
AIM: This study was designed to investigate the risk factors of pelvic lymph node metastasis in early stage cervical cancer in order to establish a prediction model for this metastasis and to explore the feasibility of conservative surgery. METHODS: The records of 207 stage IB-IIA cervical cancer patients were retrospectivly analyzed. The risk factors of pelvic lymph node metastasis were analyzed using univariate and multivariate methods. The prediction model for pelvic lymph node metastasis was established by logistic regression. RESULTS: Without preoperative adjuvant therapy, the metastatic rate of pelvic lymph node in stage IB-IIA cervical cancer was 25.1%. The serum SCCAg, the tumor diameter, the depth of cervical stroma invasion, and the cervical canal involvement were revealed as the risk factors of pelvic lymph node metastasis by univariate analysis (P<0.05). Multivariate analysis showed that the serum SCCAg and the depth of cervical stroma invasion were the independent risk factors of pelvic lymph node metastasis (P<0.05, OR = 6.917, 2.227). The patients were divided into three groups according to different independent risk factors: the low-risk group, the medium-risk group, and the high-risk group, which showed metastatic rates of pelvic lymph node of 5.7%, 16.9%, and 48.7%, respectively (P<0.001). A prediction model for pelvic lymph node metastasis was established as follows: Logti(P) = -2.534 + serum SCCAg×1.934 + depth of cervical stroma invasion×0.801. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of this prediction model were 53.8%, 83.9 %, 52.8%, 84.4%, and 76.3%, respectively. CONCLUSION: The serum SCCAg and the depth of cervical stroma invasion were the independent risk factors of pelvic lymph node metastasis in early stage cervical cancer. The proposed prediction model may help to improve the conservative surgery for early stage cervical cancer.
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Ganglios Linfáticos/patología , Neoplasias del Cuello Uterino/patología , Adulto , Anciano , Algoritmos , Análisis de Varianza , Femenino , Humanos , Histerectomía , Ganglios Linfáticos/cirugía , Metástasis Linfática , Persona de Mediana Edad , Análisis Multivariante , Estadificación de Neoplasias , Pelvis , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Factores de Riesgo , Sensibilidad y Especificidad , Resultado del Tratamiento , Neoplasias del Cuello Uterino/cirugíaRESUMEN
OBJECTIVE: The aim of this study was to explore the changes in the body state of patients with non-small cell lung cancer (NSCLC), including intestinal flora, serum inflammatory factors, immunity and adiponectin. PATIENTS AND METHODS: A total of 18 NSCLC patients (disease group) and 16 healthy people from the Medical Center (control group) were selected as research objects. The levels of immune molecules immunoglobulin A (IgA), IgG and IgM, and inflammatory factors interleukin-2 (IL-2), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α) and IL-6 were detected via enzyme-linked immunosorbent assay (ELISA). The level of adiponectin was determined using the quantitative kit. In addition, the changes in intestinal flora were analyzed. RESULTS: The overall survival time of NSCLC patients was significantly affected by IL-2 (p=0.0026), CRP (p=0.03), TNF-α (p=0.014) and IL-6 (p=0.00018). It can be seen that these inflammatory factors may play important roles in the progression of NSCLC. The levels of TNF-α (p=0.037), IL-2 (p=0.043) and CRP (p=0.000) in the peripheral blood serum were significantly higher in disease group than control group. Meanwhile, the levels of IgA (p=0.040) and IgG (p=0.000) in the peripheral blood serum were significantly higher in disease group than control group. However, no significant difference was observed in the level of IgM between the two groups (p>0.05). The expression of adiponectin gene (ADIPOQ) could remarkably affect the overall survival rate of NSCLC patients, and patients with high expression of ADIPOQ exerted significantly better prognosis (p=0.017). The level of serum adiponectin was evidently higher in control group than that in disease group (p<0.05). According to the linear discriminant analysis (LDA) score of the intestinal flora in both groups, the abundance of some intestinal flora (Enterobacter and Lachnospiraceae) was markedly higher in disease group than control group (p<0.05). However, the abundance of Bifidobacteria, Pediococcus and Lactobacillus was remarkably higher in control group than disease group (p<0.05). Correlation analysis indicated that Lactobacillus was positively correlated with Bifidobacteria (r=0.44, p=0.000), whereas was negatively correlated with Enterobacter (r=-0.22, p=0.024). Furthermore, Enterobacter was negatively associated with Bifidobacteria (r=-0.15, p=0.038) and Streptococcus (r=-0.12, p=0.046). CONCLUSIONS: Serum inflammatory factors, adiponectin, intestinal flora and immunity may play important roles in the development of NSCLC.
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Carcinoma de Pulmón de Células no Pequeñas/sangre , Neoplasias Pulmonares/sangre , Adiponectina/sangre , Adiponectina/inmunología , Proteína C-Reactiva/análisis , Proteína C-Reactiva/inmunología , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Microbioma Gastrointestinal/inmunología , Humanos , Inmunoglobulinas/sangre , Inmunoglobulinas/inmunología , Interleucina-2/sangre , Interleucina-2/inmunología , Interleucina-6/sangre , Interleucina-6/inmunología , Neoplasias Pulmonares/inmunología , Persona de Mediana Edad , Factor de Necrosis Tumoral alfa/sangre , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
OBJECTIVE: The aim of this study was to investigate the correlations between interleukin-6 (IL-6) and IL-10 gene polymorphisms with childhood acute lymphoblastic leukemia. PATIENTS AND METHODS: Specimens were collected from 200 children with acute lymphoblastic leukemia (disease group) and 200 normal children (control group) in our hospital. DNA was extracted from peripheral blood nucleated cells in both groups to detect the gene polymorphisms rs2069830 and rs2069836 of IL-6, as well as rs3024489 and rs3024493 of IL-10. Then, the content of serum IL-6 and IL-10 was determined via enzyme-linked immunosorbent assay (ELISA). RESULTS: It was found that there were differences in the distribution of alleles of IL-6 gene polymorphism rs2069830 (p=0.000) and IL-10 gene polymorphism rs3024493 (p=0.007) between the disease group and control group. The frequency of T allele of IL-6 gene polymorphism rs2069830 was higher, while that of IL-10 gene polymorphism rs3024493 was lower in the disease group. Besides, the differences in the distribution of genotypes of IL-6 gene polymorphism rs2069830 (p=0.000) and IL-10 gene polymorphism rs3024493 (p=0.000) were also observed between the disease group and control group. Moreover, the disease group had higher frequencies of TT genotype of IL-6 gene polymorphism rs2069830 and TA genotype of IL-10 gene polymorphism rs3024493. The frequencies of dominant model of IL-6 gene polymorphism rs2069830 (p=0.048) and recessive model of IL-10 gene polymorphism rs3024493 (p=0.000) in the disease group were different from those in the control group. In addition, the frequency of CC + CT dominant model of IL-6 gene polymorphism rs2069830 was lower, and the frequency of TA + AA recessive model of IL-10 gene polymorphism rs3024493 was higher in the disease group. There were differences in haplotypes CG (p=0.001), CT (p=0.007), and TG (p=0.000) of IL-6 gene, as well as haplotypes AA (p=0.002) and AT (p=0.005) of IL-10 gene between disease group and control group. Furthermore, the content of IL-6 in the serum was associated with the genotypes of IL-6 gene polymorphism rs2069830 (p<0.05), whereas the children with acute lymphoblastic leukemia carrying CT genotype had remarkably higher content of serum IL-6. The genotypes of IL-6 gene polymorphism rs2069830 was notably related to white blood cell (WBC) (p=0.002), and the WBC level was higher in children with CT genotype. The genotypes of IL-10 gene polymorphism rs3024489 had prominent correlations with platelet (PLT) (p=0.043), and the children with AA genotype had a higher PLT level. In addition, the genotypes of IL-10 gene polymorphism rs3024493 were evidently correlated with hemoglobin, which was significantly higher in children carrying TA genotype. CONCLUSIONS: The gene polymorphisms of IL-6 and IL-10 are significantly correlated with the susceptibility to and pathogenesis of childhood acute lymphoblastic leukemia.
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Interleucina-10/genética , Interleucina-6/genética , Polimorfismo Genético/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Alelos , Preescolar , Humanos , Interleucina-10/sangre , Interleucina-6/sangre , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnósticoRESUMEN
The genotype of a Beijing strain of Mycobacterium tuberculosis (MTB) is usually determined by spoligotyping. However, this technique requires special equipment and is time-consuming. In this study, we developed a new multiplex polymerase chain reaction (PCR) to differentiate between Beijing and non-Beijing strains of MTB. A total of 323 MTB isolates were genotyped by both spoligotyping and the novel multiplex PCR. By spoligotyping, 169 (52.3%) isolates were determined to be Beijing strains and the remaining 154 (47.7%) isolates were non-Beijing strains. The multiplex PCR method produced results identical to those of spoligotyping in the identification of Beijing strains of MTB. This method is highly sensitive, specific, and fast. It is also cost-effective and suitable for screening large numbers of samples.
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Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Mycobacterium tuberculosis/clasificación , Mycobacterium tuberculosis/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Tuberculosis/microbiología , Dermatoglifia del ADN/métodos , Genotipo , Humanos , Mycobacterium tuberculosis/genética , Sensibilidad y EspecificidadRESUMEN
OBJECTIVES: Rapid identification of Elizabethkingia species is essential because these species show variations in antibiotic susceptibility and clinical outcomes. Many recent inaccuracies in Elizabethkingia identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) have been noted. Accordingly, in this study, we evaluated the use of MALDI-TOF MS with an amended database to identify isolates of Elizabethkingia anophelis, E. miricola and E. meningoseptica. We then investigated the antimicrobial susceptibility of Elizabethkingia. METHODS: MALDI-TOF MS spectra were acquired from formic acid extracts overlaid with α-cyano-4-hydroxycinnamic acid matrix on target slides in linear positive ion mode for m/z 2000 to 20â000 Da. Spectra were analysed and SuperSpectra were created with SARAMIS premium software. 16S rRNA gene sequencing was used as the reference standard for species identification. Antibiotic susceptibility was assessed by broth microdilution. RESULTS: A total of 103 E. anophelis, 21 E. miricola and 11 E. meningoseptica isolates were used to calculate the average spectra and exclude common peaks. SuperSpectra were added to the SARAMIS taxonomy database; all validation results were correct, even for isolates not included in SuperSpectra. Confirmation by direct colony formation was also performed. Overall, the positive predictive value of SuperSpectra was 100% for all isolates. E. miricola (77%, 17/22) was more susceptible to levofloxacin than E. anophelis (16%, 17/105). Doxycycline and minocycline were effective against all Elizabethkingia species. CONCLUSIONS: Spectral analysis software identified significant species-specific peaks to create reference masses for efficient and accurate identification of Elizabethkingia species, providing accurate information for clinical treatment of Elizabethkingia infections.
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Antibacterianos/farmacología , Infecciones por Flavobacteriaceae/microbiología , Flavobacteriaceae/clasificación , Flavobacteriaceae/efectos de los fármacos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , ARN Polimerasas Dirigidas por ADN/genética , Flavobacteriaceae/química , Flavobacteriaceae/aislamiento & purificación , Humanos , Pruebas de Sensibilidad Microbiana , ARN Ribosómico 16S/genética , Reproducibilidad de los Resultados , Análisis de Secuencia de ADN , Programas Informáticos , Especificidad de la EspecieRESUMEN
OBJECTIVES: Tigecycline non-susceptible Acinetobacter nosocomialis (TNAN) has been discovered in clinical isolates. The resistance-nodulation-cell division (RND)-type efflux system plays a major role in tigecycline non-susceptible Acinetobacter baumannii, but the mechanism in A. nosocomialis remains unknown. Our aim was to analyse the contribution of efflux-based tigecycline resistance in clinical A. nosocomialis isolates collected from multiple medical centres in Taiwan. METHODS: A total of 57 A. nosocomialis isolates, including 46 TNAN and 11 tigecycline-susceptible A. nosocomialis (TSAN) isolates, were analysed. Of these, 46 TNAN isolates were clustered to ST410 (43 isolates) and ST68 (three isolates) by multi-locus sequence typing. RESULTS: The relationship between the RND efflux pump and tigecycline resistance was indirectly verified by successfully reducing tigecycline resistance with NMP, an efflux pump inhibitor. The three RND efflux systems (AdeABC, AdeIJK and AdeFGH) were detected in all clinical isolates. The transcript level of adeB gene increased significantly and was correlated with tigecycline resistance. Moreover, the AdeRS two-component system was further classified into four different types of AdeRS patterns considering the amino acid sequence. Further analysis showed that tigecycline resistance was related to the transcript level of adeB gene and the AdeRS pattern. CONCLUSION: This study showed that the dissemination of TNAN isolates in Taiwan is attributable mainly to the spread of ST410. The AdeABC efflux pump appeared to play an important role in the tigecycline resistance of A. nosocomialis.
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Infecciones por Acinetobacter/tratamiento farmacológico , Acinetobacter/efectos de los fármacos , Acinetobacter/aislamiento & purificación , Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana/fisiología , Proteínas de Transporte de Membrana/metabolismo , Tigeciclina/uso terapéutico , Acinetobacter/genética , Acinetobacter/metabolismo , Infecciones por Acinetobacter/microbiología , Secuencia de Aminoácidos/genética , Farmacorresistencia Bacteriana/genética , Humanos , Proteínas de Transporte de Membrana/biosíntesis , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , TaiwánRESUMEN
Electrical resistivity, dc magnetization, ac magnetic susceptibility, and magnetic relaxation studies of polycrystalline Pr(0.2)La(0.8)Fe(11.4)Al(1.6) compound have been carried out. On the basis of the measurements of isofield magnetization and ac magnetic susceptibility, we provide evidence for phase coexistence (the appearance of the ferromagnetic phase in the antiferromagnetic matrix) rather than a spin glass, resulting in a cusp observed at â¼70 K in the zero-field-cooled thermal magnetization curve under low fields. The ferromagnetic clusters or nuclei appear randomly in the antiferromagnetic matrix according to the electrical resistivity results. An excellent magnetic-resistive correspondence is observed under medium fields. Under these fields large relaxation effects are presented in the vicinity of the phase transition temperature. Nonuniform variation of the relaxation rate with temperature gives a clear picture of the nucleation and growth of phases. Distinct metastable behavior is shown during the phase transition, which brings about the step-like behavior in the various magnetization curves.
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The evolution of topological magnetic domains microscopically correlates the dynamic behavior of memory units in spintronic application. Nanometric bubbles with variation of spin configurations have been directly observed in a centrosymmetric hexagonal magnet (Mn0.5Ni0.5)65(Ga1-yYy)35 (y = 0.01) using Lorentz transmission electron microscopy. Magnetic bubbles instead of biskyrmions are generated due to the enhancement of quality factor Q caused by the substitution of rare-earth element Y. Furthermore, the bubble density and diversified spin configurations are systematically manipulated via combining the electric current with perpendicular magnetic fields. The magnetic bubble lattice at zero field is achieved after the optimized manipulation.
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We report a facile route for the green synthesis of trimethyl chitosan nitrate-capped silver nanoparticles (TMCN-AgNPs) with positive surface charge. In this synthesis, silver nitrate, glucose, and trimethyl chitosan nitrate (TMCN) were used as silver precursor, reducing agent, and stabilizer, respectively. The reaction was carried out in a stirred basic aqueous medium at room temperature without the use of energy-consuming or expensive equipment. We investigated the effects of the concentrations of NaOH, glucose, and TMCN on the particle size, zeta potential, and formation yield. The AgNPs were characterized by UV-vis spectroscopy, photon correlation spectroscopy, laser Doppler anemometry, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The catalytic activity of the TMCN-AgNPs was studied by the reduction of 4-nitrophenol using NaBH4 as a reducing agent. We evaluated the antibacterial effects of the TMCN-AgNPs on Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus using the broth microdilution method. The results showed that both gram-positive and gram-negative bacteria were killed by the TMCN-AgNPs at very low concentration (<6.13µg/mL). Moreover, the TMCN-AgNPs also showed high antibacterial activity against clinically isolated multidrug-resistant A. baumannii strains, and the minimum inhibitory concentration (MIC) was ≤12.25µg/mL.
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Acinetobacter baumannii/efectos de los fármacos , Antibacterianos/farmacología , Quitosano/química , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Nanopartículas del Metal/química , Plata/farmacología , Acinetobacter baumannii/crecimiento & desarrollo , Borohidruros/química , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Glucosa/química , Nanopartículas del Metal/ultraestructura , Pruebas de Sensibilidad Microbiana , Nitrofenoles/química , Oxidación-Reducción , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/crecimiento & desarrollo , Plata/química , Hidróxido de Sodio/química , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Electricidad EstáticaRESUMEN
A pinhole camera is an important instrument for the detection of radiation in laser plasmas. It can monitor the laser focus directly and assist in the analysis of the experimental data. However, conventional pinhole cameras are difficult to use when the target is irradiated by an ultrahigh-power laser because of the high background of hard X-ray emission generated in the laser/target region. Therefore, an improved pinhole camera has been developed that uses a grazing-incidence mirror that enables soft X-ray imaging while avoiding the effect of hard X-ray from hot dense plasmas.