Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Front Bioeng Biotechnol ; 10: 810244, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35646845

RESUMEN

Capsular contracture caused by silicone rubber is a critical issue in plastic surgery that urgently needs to be solved. Studies have shown that carbon ion implant in silicone rubber (carbon silicone rubber, C-SR) can significantly improve the capsular structure, but the effect of this improvement only appear 2months or later. In this study, asiaticoside combined with carbon silicone rubber was used to explore the changes in the capsule to provide a reference for the treatment of capsule contracture. Human fibroblasts (HFF-1) were used for in vitro experiments. The combined effect of asiaticoside and carbon silicone rubber on cell proliferation was determined by the CCK8 method, cell migration changes were measured by Transwell assays, cell cycle changes were measured by flow cytometry, and the expression levels of fibroblast transformation markers (vimentin and α-SMA), collagen (Col-1A1) and TGF-ß/Smad signaling pathway-related proteins (TGF-ß1, TßRI, TßRII and Smad2/3) were detected by immunofluorescence. In vivo experiments were carried out by subcutaneous implantation of the material in SD rats, and asiaticoside was oral administered simultaneously. WB and ELISA were used to detect changes in the expression of TGF-ß/Smad signaling pathway-related proteins. TGF-ß/Smad signaling pathway proteins were then detected and confirmed by HE, Masson and immunohistochemical staining. The results shown that asiaticoside combined with carbon ion implantation inhibited the viability, proliferation and migration of fibroblasts on silicone rubber. In vitro immunofluorescence showed that the secretion levels of α-SMA and Col-1A1 were significantly decreased, the transformation of fibroblasts into myofibroblasts was weakened, and the TGF-ß/Smad signaling pathway was inhibited. In vivo experimental results showed that asiaticoside combined with carbon silicone rubber inhibited TGF-ß1 secretion and inhibited the TGF-ß/Smad signaling pathway, reducing the thickness of the capsule and collagen deposition. These results imply that carbon silicone rubber combined with asiaticoside can regulate the viability, proliferation and migration of fibroblasts by inhibiting the TGF-ß/Smad signaling pathway and reduce capsule thickness and collagen deposition, which greatly reduces the incidence of capsule contracture.

3.
J Dig Dis ; 20(9): 447-459, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31240835

RESUMEN

OBJECTIVES: Microbiota dysbiosis in inflammatory bowel disease (IBD) has been widely reported. The gut microbiota connect diet to the metabolism by producing small molecules via diverse metabolic pathways. In this study we aimed to investigate the dietary preferences of IBD patients, and to explore the interactions among gut microbiota composition, dietary components, and metabolites in relation to IBD. METHODS: Dietary preferences of IBD patients (including those with ulcerative colitis [UC] and Crohn's disease [CD]) and health controls were investigated, and their gut microbiota were analyzed using 16S rRNA gene sequencing and metagenomic analyses of fecal and biopsy samples. The metabolite profiles of the samples were then analyzed using gas and liquid chromatography-mass spectrometry analyses. RESULTS: The daily intake of folic acid, niacin, vitamins C and D, calcium, and selenium differed significantly between patients with IBD and healthy controls. A decrease in long-chain (such as arachidic, and oleic acid) and medium-chain fatty acids (sebacic acid and isocaproic acid) as well as bile acid was observed in patients with IBD. Compared with healthy controls, 22 microbial species (including Sulfolobus acidocaldarius, and Clostridium clostridioforme CAG132) in the UC group and 37 microbial species (such as Bacteroides fragilis and Fusobacterium nucleatum) in the CD group were found to be correlated to diet and metabolites. Bacteroides fragilis was enriched in patients with IBD and associated with multi-nutrients, and 21 metabolites including 25-hydroxyvitamin D3 and taurolithocholic acid. CONCLUSIONS: This study provides an interaction network to identify key micronutrients, microbiota components and metabolites that contribute to IBD.


Asunto(s)
Dieta , Preferencias Alimentarias , Microbioma Gastrointestinal , Enfermedades Inflamatorias del Intestino/microbiología , Adulto , Biopsia , Índice de Masa Corporal , Estudios de Casos y Controles , Disbiosis/complicaciones , Heces/microbiología , Femenino , Humanos , Enfermedades Inflamatorias del Intestino/metabolismo , Enfermedades Inflamatorias del Intestino/patología , Mucosa Intestinal/microbiología , Mucosa Intestinal/patología , Masculino , Redes y Vías Metabólicas/fisiología , Metagenómica , Persona de Mediana Edad , Evaluación Nutricional , Adulto Joven
4.
RSC Adv ; 9(42): 24175-24183, 2019 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-35527896

RESUMEN

Microcapsules are widely applied in coatings; however, there are very few reports on the dispersion of microcapsules in the coating material or the effects of dispersion on their performance. Herein, the efficiency of three types of dispersants bearing distinctive functional groups for the dispersion of concentrated thermochromic microcapsules in a solvent and coating resin is studied. The dispersion properties of 35 wt% thermochromic microcapsules in toluene and in coating resin are investigated by measuring their sedimentation and rheological behavior. Interactions between the dispersant and microcapsules are characterized by Fourier transform infrared spectroscopy in order to identify the dominant dispersion mechanism. The physical quality and thermochromic performance of the coating films are characterized by electron microscopy observations and temperature variation tests. The most effective dispersant for thermochromic microcapsules is determined. Compared to the coating film containing non-dispersed microcapsules, the film with well-dispersed microcapsules shows improved surface flatness, with few or no pores in the microstructure. In addition, the color of the film with well-dispersed thermochromic microcapsules shows faster response to temperature variation, resulting in complete and uniform color transformation.

5.
J Cell Biochem ; 120(6): 9147-9158, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30582204

RESUMEN

Interstitial cystitis (IC) is a heterogeneous syndrome with unknown etiology, and microRNAs (miRs) were found to be involved in IC. In our study, we aim to explore the role of miR-132 in the inflammatory response and detrusor fibrosis in IC through the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway in rat models. A rat model of IC was established and treated with the miR-132 mimic, miR-132 inhibitor, and/or JAK-STAT signaling pathway inhibitor AG490. Enzyme-linked immunosorbent assay was applied to measure the expression of interleukin (IL)-6, IL-10, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α), and intercellular adhesion molecule-1 (ICAM-1). The urodynamic test was performed to assess urodynamic parameters, and reverse transcription quantitative polymerase chain reaction and Western blot analysis for the expression of miR-132, STAT4, suppressors of cytokine signaling 3 (SOCS3), JAK2, vascular endothelial growth factor (VEGF), IFN-γ, and TNF-α. IC rats treated with miR-132 inhibitor and AG490 had decreased collagen fiber, inflammatory cell infiltration, and mast cells, lower expression of IL-6, IL-10, IFN-γ, TNF-α, ICAM-1, collagens I and III, and alleviated urodynamic parameters and decreased expression of STAT4, VEGF, JAK2, IFN-γ, TNF-α, and increased expression of SOCS3. Taken together, our data indicate that downregulation of miR-132 alleviates inflammatory response and detrusor fibrosis in IC via the inhibition of the JAK-STAT signaling pathway.


Asunto(s)
Cistitis Intersticial/metabolismo , Inflamación/metabolismo , Quinasas Janus/metabolismo , MicroARNs/metabolismo , Animales , Cistitis Intersticial/tratamiento farmacológico , Femenino , Humanos , Inmunohistoquímica , Técnicas In Vitro , Inflamación/tratamiento farmacológico , Janus Quinasa 2/metabolismo , MicroARNs/genética , Ratas , Ratas Sprague-Dawley , Factor de Transcripción STAT4/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Factor de Necrosis Tumoral alfa/metabolismo , Tirfostinos/uso terapéutico , Factor A de Crecimiento Endotelial Vascular/metabolismo
6.
BMC Infect Dis ; 18(1): 315, 2018 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-29986658

RESUMEN

BACKGROUND: Hepatitis B virus (HBV) is considered highly prevalent in West Africa. However, major gaps in surveillance exist in Sierra Leone. Although healthcare workers (HCWs) are at high risk for HBV infection, little is known about the prevalence and knowledge of hepatitis B among HCWs in Sierra Leone. METHODS: A cross-sectional study of all HCWs at the No. 34 Military Hospital located in Freetown, Sierra Leone, was conducted from March 20 to April 10, 2017. Whole blood was collected and screened for HBV markers using a one-step rapid immunochromatographic test with positive samples tested for HBV DNA. Additionally, questionnaires assessing self-reported knowledge of HBV infections were administered to all participants. Data were processed and analyzed using SPSS (version 17.0) software. RESULTS: A total of 211 HCWs were included in this study with a median age of 39.0 years (range: 18-59). Of the participating HCWs, 172 (81.5%) participants were susceptible (all markers negative), 21(10.0%) were current HBV (HBsAg positive) and nine (4.3%) were considered immune because of past infection (HBsAg negative and anti-HBc positive; anti-HBs positive). Additionally, nine (4.3%) participants displayed immunity to the virus as a result of prior hepatitis B vaccination (only anti-HBs positive). Of the 21 HCWs with positive HBsAg, 13 (61.9%) had detectable HBV DNA. There was a significantly lower risk for current HBV infection among HCWs older than 39 years (OR 0.337, p = 0.046). In addition, only 14 (6.6%), 73 (34.6%) and 82 (38.9%) participants in this survey had adequate knowledge about the clinical outcome, routes of transmission, and correct preventive measures of HBV infection, respectively. CONCLUSIONS: HCWs in Sierra Leone lacked adequate knowledge of the hepatitis B virus. Additionally, the low coverage rate of hepatitis B vaccination among HCWs fails to meet WHO recommendations, leaving many of the sampled HCWs susceptible to infection. This study reaffirms the need for more intensive training for HCWs in addition to strengthening vaccination programmes to protect HCWs against HBV in Sierra Leone.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Personal de Salud/estadística & datos numéricos , Hepatitis B/epidemiología , Adolescente , Adulto , Estudios Transversales , Femenino , Hepatitis B/prevención & control , Antígenos de Superficie de la Hepatitis B/sangre , Vacunas contra Hepatitis B , Virus de la Hepatitis B/patogenicidad , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Sierra Leona/epidemiología , Encuestas y Cuestionarios , Vacunación/estadística & datos numéricos
7.
Nat Commun ; 9(1): 673, 2018 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-29445153

RESUMEN

The global spread of Zika virus (ZIKV) and its unexpected association with congenital defects necessitates the rapid development of a safe and effective vaccine. Here we report the development and characterization of a recombinant chimeric ZIKV vaccine candidate (termed ChinZIKV) that expresses the prM-E proteins of ZIKV using the licensed Japanese encephalitis live-attenuated vaccine SA14-14-2 as the genetic backbone. ChinZIKV retains its replication activity and genetic stability in vitro, while exhibiting an attenuation phenotype in multiple animal models. Remarkably, immunization of mice and rhesus macaques with a single dose of ChinZIKV elicits robust and long-lasting immune responses, and confers complete protection against ZIKV challenge. Significantly, female mice immunized with ChinZIKV are protected against placental and fetal damage upon ZIKV challenge during pregnancy. Overall, our study provides an alternative vaccine platform in response to the ZIKV emergency, and the safety, immunogenicity, and protection profiles of ChinZIKV warrant further clinical development.


Asunto(s)
Vacunas Virales/genética , Vacunas Virales/inmunología , Infección por el Virus Zika/prevención & control , Virus Zika/inmunología , Aedes/virología , Animales , Anticuerpos Neutralizantes/biosíntesis , Anticuerpos Antivirales/biosíntesis , Modelos Animales de Enfermedad , Virus de la Encefalitis Japonesa (Especie)/genética , Virus de la Encefalitis Japonesa (Especie)/inmunología , Femenino , Ingeniería Genética , Humanos , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Macaca mulatta , Masculino , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos BALB C , Mosquitos Vectores/virología , Embarazo , Vacunas Atenuadas/efectos adversos , Vacunas Atenuadas/genética , Vacunas Atenuadas/inmunología , Vacunas Sintéticas/efectos adversos , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología , Vacunas Virales/efectos adversos , Viremia/prevención & control , Virus Zika/genética , Infección por el Virus Zika/inmunología , Infección por el Virus Zika/virología
8.
Am J Transl Res ; 9(3): 1193-1202, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28386345

RESUMEN

OBJECTIVE: This study aimed to explore the role of the transforming growth factor-ß/mitogen activated protein kinase (TGF-ß/MAPK) signaling pathway in the effects of bone marrow mesenchymal stem cells (BMSCs) on urinary control and interstitial cystitis in a rat model of urinary bladder transplantation. METHODS: A urinary bladder transplantation model was established using Sprague-Dawley rats. Rats were assigned to normal (blank control), negative control (phosphate-buffered saline injection), BMSCs (BMSC injection), sp600125 (MAPK inhibitor injection), or protamine sulfate (protamine sulfate injection) groups. Immunohistochemistry, urodynamic testing, hematoxylin-eosin staining, Western blotting, enzyme-linked immunosorbent assay, and MTT assay were used to assess BMSC growth, the kinetics of bladder urinary excretion, pathological changes in bladder tissue, bladder tissue ultrastructure, the expression of TGF-ß/MAPK signaling pathway-related proteins, levels of inflammatory cytokines, and the effects of antiproliferative factor on cell proliferation. RESULTS: Compared with normal, negative control, BMSCs, and sp600125 groups, rats in the PS group exhibited decreased discharge volume, maximal micturition volume, contraction interval, and bladder capacity but increased residual urine volume, bladder pressure, bladder peak pressure, expression of TGF-ß/MAPK signaling pathway-related proteins, levels of inflammatory cytokines, and growth inhibition rate. Levels of inflammatory cytokines and the growth inhibition rate were positively correlated with the expression of TGF-ß/MAPK signaling pathway-related proteins. CONCLUSIONS: Our findings demonstrate that the TGF-ß/MAPK signaling pathway mediates the beneficial effects of BMSCs on urinary control and interstitial cystitis.

9.
J Biol Chem ; 292(13): 5488-5498, 2017 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-28196868

RESUMEN

The type III secretion system is a highly conserved virulence mechanism that is widely distributed in Gram-negative bacteria. It has a syringe-like structure composed of a multi-ring basal body that spans the bacterial envelope and a projecting needle that delivers virulence effectors into host cells. Here, we showed that the Yersinia inner rod protein YscI directly interacts with the needle protein YscF inside the bacterial cells and that this interaction depends on amino acid residues 83-102 in the carboxyl terminus of YscI. Alanine substitution of Trp-85 or Ser-86 abrogated the binding of YscI to YscF as well as needle assembly and the secretion of effectors (Yops) and the needle tip protein LcrV. However, yscI null mutants that were trans-complemented with YscI mutants that bind YscF still assembled the needle and secreted Yops, demonstrating that a direct interaction between YscF and YscI is critical for these processes. Consistently, YscI mutants that did not bind YscF resulted in greatly decreased HeLa cell cytotoxicity. Together, these results show that YscI participates in needle assembly by directly interacting with YscF.


Asunto(s)
Proteínas Bacterianas/metabolismo , Sistemas de Secreción Tipo III/biosíntesis , Yersinia pestis/química , Sitios de Unión/genética , Muerte Celular , Células HeLa , Humanos , Mutagénesis Sitio-Dirigida , Unión Proteica , Sistemas de Secreción Tipo III/química , Sistemas de Secreción Tipo III/toxicidad , Yersinia pestis/patogenicidad
10.
BMC Med Educ ; 15: 93, 2015 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-26032174

RESUMEN

BACKGROUND: Simulators have been widely used to train operational skills in urology, how to improve its effectiveness deserves further investigation. In this paper, we evaluated training using a novel transparent anatomic simulator, an opaque model or no simulator training, with regard to post-training ureteroscopy and cystoscopy proficiency. METHODS: Anatomically correct transparent and non-transparent endourological simulators were fabricated. Ten experienced urologists provided a preliminary evaluation of the models as teaching tools. 36 first-year medical students underwent identical theoretical training and a 50-point examination of theoretical knowledge. The students were randomly assigned to receive training with the transparent simulator (Group 1), the non-transparent simulator (Group 2) or detailed verbal instruction only (Group 3). 12 days after the training session, the trainees' skills at ureteral stent insertion and removal were evaluated using the Uro-Scopic Trainer and rated on an Objective Structured Assessment of Technical Skills (OSATS) scale. RESULTS: The new simulators were successfully fabricated in accordance with the design parameters. Of the ten urologists invited to evaluate the devices, 100% rated the devices as anatomically accurate, 90% thought both models were easy to use and 80% thought they were good ureteroscopy and cystoscopy training tools. The scores on the theoretical knowledge test were comparable among the training groups, and all students were able to perform ureteral stent insertion and removal. The mean OSATS scores of groups 1, 2 and 3 were 21.83 ± 3.64, 18.50 ± 4.03 and 15.58 ± 2.23 points, respectively, (p = 0.001). CONCLUSIONS: Simulator training allowed students to achieve higher ureteroscopic and cystoscopic proficiency, and transparent simulators were more effective than non-transparent simulators.


Asunto(s)
Competencia Clínica , Simulación por Computador , Cistoscopía/educación , Educación de Pregrado en Medicina , Ureteroscopía/educación , Adulto , Educación Médica Continua , Evaluación Educacional , Diseño de Equipo , Femenino , Humanos , Internado y Residencia , Masculino , Persona de Mediana Edad , Urología/educación
11.
Exp Ther Med ; 5(4): 1184-1188, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23596488

RESUMEN

The aim of this study was to study the clinical value of prethrombotic state and treatment with low molecular weight heparin (LMWH) in senile patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) combined with respiratory failure. Hemorheological markers (hematocrit, blood viscosity and plasma viscosity), fibrinogen (FIB), D-dimer and gas analysis were evaluated in 30 senile patients with AECOPD combined with respiratory failure and compared with those in 30 cases without respiratory failure. A total of 30 cases with AECOPD combined with respiratory failure were randomly divided into treatment and control groups. The two groups received conventional treatment. The treatment group also received LMWH injections every 12 h for 6 days and the clinical effect was observed. The levels of FIB, D-dimer, hematocrit, blood viscosity and plasma viscosity were significantly higher in the patients with AECOPD combined with respiratory failure compared with those in the patients without respiratory failure. The plasma D-dimer and FIB levels had significantly positive correlations with the partial pressure of CO2 (PaCO2) and negative correlations with the partial pressure of O2 (PaO2) in the patients with AECOPD combined with respiratory failure. The curative effect was improved in the treatment group, compared with that in the control group without side-effects. However, no significant changes in activated partial thromboplastin time (APTT) and international normalized ratio (INR) were observed between the treatment and control groups. The senile patients with AECOPD combined with respiratory failure suffered from hypercoagulation. Early detection and diagnosis of the prethrombotic state and timely treatment with LMWH may benefit these patients without side-effects.

13.
Zhonghua Yu Fang Yi Xue Za Zhi ; 42(9): 653-7, 2008 Sep.
Artículo en Chino | MEDLINE | ID: mdl-19175175

RESUMEN

OBJECTIVE: To establish a set of procedure for recovery and species identification of Legionella from the surface environmental water. METHODS: Forty-four water samples were collected in eight parks of Guangzhou city from August to November in 2006. The bacteriologic examination was performed by cultivation on BCYEalpha plate, and 108 presumptive Legionella colonies were picked and their homogeneous relationship was analyzed by using an amplified fragment length polymorphism (AFLP) method. Species identification was carried out by latex agglutination test, biochemical characterization, analysis of cellular fatty acids composition, 16 S rRNA gene and mip gene sequencing. RESULTS: Legionella was recovered among 27 (61.36%) samples of all eight parks, and 31 different strains were identified from those 108 presumptive Legionella isolates by AFLP method, including 20 strains of L. pneumophila, five strains of L. feeleii, four strains of L. longbeachae, one strain of L. oakridgensis and one strain of L. sainthelensi, and L. pneumophila could be easily differentiated by phenotypic and biochemical characteristics, latex agglutination test or analysis of the cellular fatty acids composition . However, uncertain factors were existing in those phenotypic identification methods as compared to the sequence analysis. CONCLUSION: The taxonomic analysis of the Legionellae family should be dependent on the 16 S rRNA gene or mip gene.


Asunto(s)
Monitoreo del Ambiente/métodos , Legionella/aislamiento & purificación , Microbiología del Agua , Técnicas Bacteriológicas , ADN Bacteriano/genética , Legionella/genética , ARN Bacteriano , ARN Ribosómico 16S
14.
Artículo en Chino | MEDLINE | ID: mdl-16201466

RESUMEN

OBJECTIVE: To elucidate the relationship between HBV core promoter mutation and clinical features as well as its effects on serum e system and viral replication. METHODS: Semi-nested mutation specific PCR (msPCR) was employed for detecting core promoter mutation at nt 1 762-1 764 in 97 patients with HBV infection. RESULTS: The msPCR method was demonstrated to be specific and reliable for the mutation detection by sequencing the PCR products. The detection ratio of the mutation in patients with acute hepatitis, mild, moderate and severe chronic hepatitis and liver cirrhosis was 2/5, 7/43, 10/31, 1/3 and 7/15, respectively. The detection rate of the mutation in liver cirrhosis was significantly higher than that in light chronic hepatitis (P < 0.025). In 92 patients with chronic HBV infection, HBeAg positive rate in wild (25/92), mutant (42/92) and mixed (25/92) strain infection was 80.0%, 56.0% and 64.3%, HBV DNA level was (4.4 +/- 8.5) x 10(8), (1.1 +/- 1.6) x 10(9) and (1.4 +/- 1.8) x 10(9) copies/ml, the rate of abnormal ALT was 44.0%, 52.0% and 42.6%; ALT level was (58.6 +/- 79.0), (57.1 +/- 75.2) and (62.6 +/- 90.3) IU/L, respectively (P > 0.05). CONCLUSIONS: The msPCR method for detecting core promoter mutation at nt 1 762-1 764 is specific and reliable. Core promoter mutation is associated with the severity of liver disease, but neither related to the status of e system in serum nor to the virus replication.


Asunto(s)
Antígenos del Núcleo de la Hepatitis B/genética , Virus de la Hepatitis B/genética , Hepatitis B/patología , Mutación , Regiones Promotoras Genéticas/genética , Adolescente , Adulto , Anciano , Niño , ADN Viral/sangre , ADN Viral/genética , Ensayo de Inmunoadsorción Enzimática , Femenino , Hepatitis B/sangre , Hepatitis B/virología , Antígenos del Núcleo de la Hepatitis B/sangre , Virus de la Hepatitis B/aislamiento & purificación , Virus de la Hepatitis B/fisiología , Interacciones Huésped-Patógeno , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Replicación Viral , Adulto Joven
15.
J Gen Appl Microbiol ; 51(1): 11-9, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15864756

RESUMEN

A PCR-based screening method was used to study the genetic variations of the pgm locus among natural isolates of Yersinia pestis from China. Our results indicate that genetic variations in the pgm locus are well correlated with biovars of Y. pestis and plague foci, suggesting that the pgm locus plays a role in Y. pestis adaptation to its environment. The gene encoding two-component regulatory system sensor kinase became a pseudogene in all strains of biovar Orientalis due to a thymidine deletion, while it is intact in all the strains of the other biovars. Only strains from Foci H and L are the same as Yersinia pseudotuberculosis in that they have an intact transmembrane helix in the sensor kinase protein, which is lost in all the other strains because of the 18 bp in-frame deletion. The IS100 element that flanks the 39 terminus of the pgm locus was inserted into the chromosome during the within-species microevolution of Y. pestis, which is absent in strains from Foci G, H and L and also in Y. pseudotuberculosis. This fact indicates that the strains from these three foci are of an older lineage of Chinese Y. pestis. It is this IS100 element's absence that maintained high stability of the pgm locus in the Y. pestis strains from these three foci. The IS285 element insertion in the pigmentation segment and the IS100 element insertion in the downstream flanking region of the pgm locus are only present in strains from Foci H and L. The flanking region outside the 59 terminus of the upstream IS100 element is identical in the strains from these two foci, which is different in the other strains. All of these unique characteristics suggest that they are of a special lineage of Chinese Y. pestis.


Asunto(s)
Genes Bacterianos , Yersinia pestis/genética , Alelos , Secuencia de Bases , China , Elementos Transponibles de ADN , ADN Bacteriano/genética , Variación Genética , Inestabilidad Genómica , Islas Genómicas , Humanos , Fenotipo , Pigmentación/genética , Reacción en Cadena de la Polimerasa , Seudogenes , Yersinia pestis/clasificación , Yersinia pestis/aislamiento & purificación , Yersinia pseudotuberculosis/clasificación , Yersinia pseudotuberculosis/genética
16.
Artículo en Chino | MEDLINE | ID: mdl-12198569

RESUMEN

To obtain oligonucleotide aptamers, specifically binding to Bacillus anthracis spores, and to find the relationship between the structures and the affinities, and to determine whether the aptamers can be used as a novel molecule for spore detection, a synthetic 35 mer random DNA library was subjected to 18 rounds of selection by using SELEX (systematic evolution of ligands by exponential enrichment) protocol against spores of Bacillus anthracis vaccine strain A. 16R. The selected aptamers were cloned and sequenced. Software packages CLUSTALX (1.8) and DNASIS v2.5 were employed to analyze the conserved sequences and second structures of the aptamers, respectively. Affinities of aptamers to the spores were visualized by biotin streptavidin horseradish peroxidase system. DAB was used to visualize signals, as an assay method. A membrane-based hybrid sandwich assay was developed for detecting Bacillus anthracic spores by using a 5'-biotinylated ssDNA aptamers and anti-spore antibodies. PCR amplification band pattern of the first round selection was different from that of the ninth round. The binding assay demonstrated that the affinity of the eighteenth round pool increased thirty-seven folds more than that of the first round pool. The affinities of the aptamers were different: the highest A at 450 nm was 1.20, and the lowest was 0.20. The secondary structure analysis revealed possible stem-loop and hairpin structures for binding to the spores. The colorimetry on the immuno-membrane got the best signal with a ratio of 16 microgram aptamer to 4x10(7) spores. A set of aptamers with considerable binding affinity to Bacillus anthracis spores was successfully selected from the initial random ssDNA pool. The stem-loop and hairpin at 5' end of the aptamers worked as the main motif in the interaction between oligonucleotides and spores, while the neighbor bases of the triple structure might affect the stability. Therefore ssDNA aptamers seem to be a type of potential diagnostic molecule.


Asunto(s)
Bacillus anthracis/metabolismo , Oligodesoxirribonucleótidos/metabolismo , Clonación Molecular , Conformación de Ácido Nucleico , Oligodesoxirribonucleótidos/química , Reacción en Cadena de la Polimerasa/métodos , Análisis de Secuencia de ADN , Esporas Bacterianas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA