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1.
Zhonghua Yu Fang Yi Xue Za Zhi ; 56(9): 1302-1306, 2022 Sep 06.
Artículo en Chino | MEDLINE | ID: mdl-36207895

RESUMEN

Objective: To analyze the epidemiological characteristics of pulmonary tuberculosis (PTB) in Fengtai District from 2011 to 2021. Methods: A retrospective study was conducted, the data of PTB patients in Fengtai District from 2011 to 2021 were collected in Chinese disease prevention and Control Information System, which included etiological classification, gender, age, occupation, onset time, demographic information etc. the epidemiological characteristics of reported PTB patients was analysis. Results: A total of 10 342 cases of PTB were reported from 2011 to 2021 in Fengtai District, with an average annual reported incidence rate of 42.87/ 100 000. The incidence rate was the highest in 2012(75.89/100 000), and significantly declined from 2013, which declined to 29.70/100 000 in 2017. It showed a slow rise from 2018 to 2021. The difference was statistically significant (χ2=1 471.77,P<0.001).There were 2 975 cases of etiologic positive PTB from 2011 to 2021, and 76 cases of Rifampicin-resistant PTB from 2017 to 2021. The ratio of male cases to female was 1.75, the average annual incidence rate of male (53.94/100 000) was higher, than female(31.57/100 000).(χ2=704.01,P<0.001). Among all age groups, 25-29 years group, 20-24 years group and 30-34 years group had the highest proportion, which were 1 506 cases (14.56%) , 1 292 cases (12.49%) and 1 024 cases (9.90%) respectively. The average annual incidence rate was the lowest in the group less than 10 years old (1.43/100 000), and the highest in the group 85 years old and over (195.20/100 000), the difference was statistically significant(χ2=3164.24, P<0.001). The top occupations from high to low were housework and unemployment (2 917 cases, 28.21%), retirees (2 308 cases, 22.32%), workers (1 047 cases, 10.12%), cadres and staff (950 cases, 9.19%), farmers (860 cases, 8.32%), business services (698 cases, 6.75%), teachers and students (455 cases, 4.40%). Conclusion: From 2011 to 2021, the incidence rate of PTB was decreased from 2012 to 2017, and slowly increased lately in Fengtai District. The epidemiological characteristics of PTB vary in different age and gender.


Asunto(s)
Rifampin , Tuberculosis Pulmonar , Adulto , Anciano de 80 o más Años , Beijing , Niño , China/epidemiología , Femenino , Humanos , Incidencia , Masculino , Estudios Retrospectivos , Tuberculosis Pulmonar/epidemiología , Tuberculosis Pulmonar/prevención & control
2.
J Prev Alzheimers Dis ; 6(3): 204-211, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31062836

RESUMEN

OBJECTIVE: The associations between dietary fat intake and cognitive function are inconsistent and inconclusive. This study aimed to provide a quantitative synthesis of prospective cohort studies on the relationship between dietary fat intake and cognitive function among older adults. METHODS: PubMed, EMBASE, PsycINFO and Web of Science databases were searched for prospective cohort studies published in English before March 2018 reporting cognitive outcomes in relation to dietary fat intake. Four binary incident outcomes included were mild cognitive impairment (MCI), dementia, Alzheimer disease (AD) and cognitive impairment. The categories of dietary fat intake were based on fat consumption or the percentage of energy from fat consumption, including dichotomies, tertiles, quartiles and quintiles. The relative risk (RR) with the corresponding 95% confidence intervals (CIs) was pooled using a random effects model. RESULTS: Nine studies covering a total of 23,402 participants were included. Compared with the lowest category of consumption, the highest category of saturated fat intake was associated with an increased risk of cognitive impairment (RR = 1.40; 95% CI: 1.02-1.91) and AD (RR: 1.87, 95% CI: 1.09-3.20). The total and unsaturated fat intake was not statistically associated with cognitive outcomes with significant between-study heterogeneity. CONCLUSION: This study reported a detrimental association between saturated fat intake and cognitive impairment and mixed results between unsaturated fat intake and selected cognitive outcomes. Given the substantial heterogeneity in the sample size and methodology used across studies, the evidence presented here should be interpreted with caution.


Asunto(s)
Cognición/fisiología , Disfunción Cognitiva/epidemiología , Grasas de la Dieta/efectos adversos , Factores de Edad , Estudios de Cohortes , Humanos , Estudios Prospectivos , Factores de Riesgo
3.
Zhonghua Liu Xing Bing Xue Za Zhi ; 39(10): 1394-1401, 2018 Oct 10.
Artículo en Chino | MEDLINE | ID: mdl-30453443

RESUMEN

Objective: To carry out a quantitative estimate that related to the effects of short-term exposure to PM(2.5) on all-cause mortality and emergency visits in China by using the systematic review and Meta-analysis. Methods: We selected all the studies published before March 2018 from China National Knowledge Infrastructure, Wanfang database, PubMed and EMBASE and data on relative risk (RR), excess risk (ER) and their 95%CIs: appeared in these papers were extracted. According to the differences in the size or direction (heterogeneity) of the results, we computed summary estimates of the effect values using a random-effect or fixed effect model. We also conducted the subgroup analysis and Meta-analysis to have assessed the selected studies for the evidence of study bias. Results: A total of 33 original studies, indexed in databases, were identified. Among those studies, 39 sets of data on mortality and 4 sets of data on emergency were valid to show that within the daily concentration range from 47.7 to 176.7 µg/m(3), for 10 µg/m(3) increases in PM(2.5) concentrations, it would increase the daily numbers of deaths by 0.49% (95%CI: 0.39%-0.59%) and 0.30% (95%CI: 0.10%-0.51%) for all-cause deaths and all-cause emergency-room visits, respectively. For subgroup analysis, the combined effect of PM(2.5) in causing short-term all-cause deaths in the northern areas (ER=0.42%, 95%CI: 0.30%-0.54%) seemed lower than that in the southern areas (ER=0.63%, 95%CI: 0.44%-0.82%). The combined effect of PM(2.5) concentration below 75 µg/m(3) (ER=0.50%, 95%CI: 0.37%-0.62%) was higher than that of PM(2.5) concentration ≥75 µg/m(3) (ER=0.39%, 95%CI: 0.26%-0.52%). Conclusion: Within the concentration range from 47.7 to 176.7 µg/m(3), short-term exposure to current level of PM(2.5) might increase both the all-cause daily mortality and daily emergency visits in China.


Asunto(s)
Contaminación del Aire/estadística & datos numéricos , Servicio de Urgencia en Hospital/estadística & datos numéricos , Exposición a Riesgos Ambientales/estadística & datos numéricos , Material Particulado/toxicidad , Contaminantes Atmosféricos , Contaminación del Aire/efectos adversos , China , Bases de Datos Factuales , Exposición a Riesgos Ambientales/efectos adversos , Femenino , Humanos , Masculino , Factores de Tiempo
4.
J Environ Sci Health B ; 53(2): 126-134, 2018 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-29227209

RESUMEN

A simple, sensitive, reliable method was developed for the simultaneous determination of organochlorine and pyrethriod pesticide residues in Chinese patent medicines Six ingredient rehmannia pills and Xiaoyao pills. These pesticides were extracted by ethyl acetate. The extraction time and volume of ethyl acetate were optimized. Cleanup of extracts was performed with dispersive-solid phase extraction using graphitized carbon black as the sorbent. The determination of pesticides in the final extracts was carried out by gas chromatography-tandem mass spectrometry in multiple reaction monitoring mode (GC-MS/MS, MRM). The linearity of the calibration curves is good in matrix-matched standard and yields the coefficients of determination (R2) ≥0.99 for all of the target analytes. Under optimized conditions, the average recoveries (five replicates) for most pesticides range from 75.5% to 114.6%, and RSDs are less than 10.0%. The LODs of 18 pesticides in Six ingredient rehmannia pill and Xiaoyao pills are in the range of 0.01-8.82 µg kg-1. The developed method meets the requirements of pesticide residue analysis and could be effectively used for routine analysis of the organochlorine and pyrethriod pesticide residues in Six ingredient rehmannia pills and Xiaoyao pills.


Asunto(s)
Medicamentos Herbarios Chinos/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Residuos de Plaguicidas/análisis , Piretrinas/análisis , Espectrometría de Masas en Tándem/métodos , Calibración , Medicamentos Herbarios Chinos/química , Hidrocarburos Clorados/análisis , Hidrocarburos Clorados/química , Límite de Detección , Medicamentos sin Prescripción , Piretrinas/química , Extracción en Fase Sólida/métodos
5.
Acta Neurol Scand ; 137(2): 277-282, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29023630

RESUMEN

BACKGROUND: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder of the central nervous system (CNS). Interleukin (IL)-6 and IL-17A may play important roles in the pathogenesis of this disease. High-mobility group box protein 1 (HMGB1), a small but highly conserved ubiquitous protein, is recognized to be a potent innate inflammatory mediator that can activate the nuclear factor light chain enhancer of activated B cells and release cytokines such as IL-6 and IL-17A when released extracellularly. However, whether cerebrospinal fluid (CSF) HMGB1 levels are altered in anti-NMDAR encephalitis is still unclear. OBJECTIVE: The aim of this study was to determine whether a correlation exists between the CSF concentrations of HMGB1 and IL-6 and IL-17A in anti-NMDAR encephalitis patients. We also sought to assess whether HMGB1 influences the clinical outcomes in anti-NMDAR encephalitis patients. METHODS: Thirty-three patients with anti-NMDAR antibodies and 38 controls were recruited. CSF HMGB1 was measured using an enzyme-linked immunosorbent assay. The main clinical outcomes were evaluated using the modified Rankin scale (mRS). The data were extracted using microarray analysis software. RESULTS AND CONCLUSION: Our results showed significant increases in CSF HMGB1, IL-6, and IL-17A (P < .05) in anti-NMDAR encephalitis patients. But between 3 months' mRS scores in anti-NMDAR encephalitis patients and CSF data, there was no correlation. Our study suggests that HMGB1 CSF levels are increased in patients with anti-NMDAR encephalitis and reflect the underlying neuroinflammatory process.


Asunto(s)
Encefalitis Antirreceptor N-Metil-D-Aspartato/líquido cefalorraquídeo , Proteína HMGB1/líquido cefalorraquídeo , Interleucina-6/líquido cefalorraquídeo , Adulto , Estudios Transversales , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Interleucina-17/líquido cefalorraquídeo , Masculino
6.
Cancer Radiother ; 21(2): 99-103, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28325619

RESUMEN

PURPOSE: To test if active breath control during cone-beam computed tomography (CBCT) could improve planning target volume during accelerated partial breast radiotherapy for breast cancer. METHODS: Patients who were more than 40 years old, underwent breast-conserving dissection and planned for accelerated partial breast irradiation, and with postoperative staging limited to T1-2 N0 M0, or postoperative staging T2 lesion no larger than 3cm with a negative surgical margin greater than 2mm were enrolled. Patients with lobular carcinoma or extensive ductal carcinoma in situ were excluded. CBCT images were obtained pre-correction, post-correction and post-treatment. Set-up errors were recorded at left-right, anterior-posterior and superior-inferior directions. The differences between these CBCT images, as well as calculated radiation doses, were compared between patients with active breath control or free breathing. RESULTS: Forty patients were enrolled, among them 25 had active breath control. A total of 836 CBCT images were obtained for analysis. CBCT significantly reduced planning target volume. However, active breath control did not show significant benefit in decreasing planning target volume margin and the doses of organ-at-risk when compared to free breathing. CONCLUSION: CBCT, but not active breath control, could reduce planning target volume during accelerated partial breast irradiation.


Asunto(s)
Neoplasias de la Mama/radioterapia , Tomografía Computarizada de Haz Cónico/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Respiración , Adulto , Anciano , Femenino , Humanos , Persona de Mediana Edad , Estudios Prospectivos
7.
Stand Genomic Sci ; 10: 62, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26380647

RESUMEN

Bacillus thuringiensis is the most widely used biological pesticide in the world. It belongs to the Bacillus cereus sensu lato group, which contains six species. Among these six species, B. thuringiensis, B. anthracis, and B. cereus have a low genetic diversity. B. thuringiensis strain HD521 shows maroon colony which is different from most of the B. thuringiensis strains. Strain HD521 also displays an ability to inhibit plant sheath blight disease pathogen (Rhizoctonia solani AG1 IB) growth and can form bipyramidal parasporal crystals consisting of three cry7 genes. These crystals have an insecticidal activity against Henosepilachna vigintioctomaculata larva (Coleoptera). Here we report the complete genome sequence of strain HD521, which has one chromosome and six circular plasmids.

8.
Support Care Cancer ; 23(2): 561-79, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25339619

RESUMEN

OBJECTIVE: We performed a systematic review and meta-analysis to explore the clinical application of Chinese herbal medicine (CHM) for chemotherapy-induced leucopenia and to evaluate its effectiveness and safety. METHODS: We included randomized clinical trials (RCTs) with no limitation of publication type or language. Participants were cancer patients undergoing chemotherapy. Trial designs included comparisons of CHM with granulocyte colony-stimulating factor, supportive treatments for leucopenia, and/or placebo. Main outcomes were white blood cell count and incidence of leucopenia. Screening, data extraction, and analysis were conducted according to the PRISMA guidelines. RESULTS: Eighty-three RCTs (n = 8,012) met the inclusion criteria. Fifteen Chinese patent medicines and 47 different modified formulas were used as prophylaxis for chemotherapy-induced leucopenia. Compared with no treatment, CHMs were shown to decrease the incidence of leucopenia (odds ratio (OR) -0.23 [-0.20, -0.27]), P < 0.00001), with the number needed to treat (NNT) -3.45 [-3.13, -3.85]. Subgroup analysis suggested a prophylactic benefit for white blood cell counts with Fufang E-jiao Jiang, Diyu Shengbai Pian, combination Huangqi and Shengmai Zhusheye, and Fuzhong Shengbai Fang for patients undergoing chemotherapy. No serious adverse events were reported. Only three articles (3/83, 4 %) were rated as having adequate methodological quality with a low level of bias. Funnel plots were asymmetrical. CONCLUSIONS: Some CHMs may be efficacious in the treatment of chemotherapy-induced leucopenia, but the majority of reviewed studies were of poor quality. Results need to be confirmed in rigorously conducted high-quality trials, including pharmacokinetic studies to ensure that there are no interactions between the CHM agent and chemotherapy.


Asunto(s)
Neutropenia Febril Inducida por Quimioterapia/prevención & control , Medicamentos Herbarios Chinos/uso terapéutico , Factor Estimulante de Colonias de Granulocitos/uso terapéutico , Neoplasias/tratamiento farmacológico , Antineoplásicos/efectos adversos , Antineoplásicos/uso terapéutico , Pueblo Asiatico , Medicamentos Herbarios Chinos/efectos adversos , Necesidades y Demandas de Servicios de Salud , Humanos , Recuento de Leucocitos , Ensayos Clínicos Controlados Aleatorios como Asunto
9.
Inflamm Res ; 61(1): 17-26, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21947361

RESUMEN

OBJECTIVE: Mice injected with Bacillus Calmette-Guérin (BCG) were challenged with lipopolysaccharide (LPS) to induce inflammatory liver injury. This study was performed to explore the protective effects of interleukin (IL)-4 against liver injury induced by BCG and LPS in mice. MATERIALS AND METHODS: Mice injected with BCG (125 mg/kg) were challenged with LPS (10 µg/kg) to induce the model of inflammatory liver injury. Half an hour after injection of LPS, mice were subcutaneously administered rmIL-4 at 5 and 0.5 µg/kg, respectively. Liver injury was evaluated by serum transaminase assay and H & E staining. Liver cytokine concentrations were determined by enzyme-linked immunosorbent assay, and intrahepatic cytokine and iNOS mRNA levels by reverse transcriptase polymerase chain reaction. Intrahepatic apoptosis was evaluated by terminal deoxynucleotidyl transferase mediated nick end labeling. NF-κB p65 and ERK signal pathway was detected by Western-blotting. NF-κB signal pathway was also detected by electrophoretic mobility shift assay. RESULTS: IL-4 reduced the serum ALT, AST and LDH, alleviated the inflammatory cells infiltration, down regulated the expression of TNF-α, IL-1ß, IFN-γ, IL-6 and iNOS mRNA in liver, and alleviated hepatic glutathione depletion (GSH). In addition, IL-4 displayed inhibition of extracellular signal-regulated kinase phosphorylation and NF-κB activation. CONCLUSION: IL-4 may protect mice against BCG/LPS-induced immune liver injury, besides ERK and NF-κB signal pathways were involved in the effects.


Asunto(s)
Interleucina-4/metabolismo , Lipopolisacáridos/metabolismo , Mycobacterium bovis/metabolismo , Alanina Transaminasa/metabolismo , Animales , Aspartato Aminotransferasas/metabolismo , Femenino , Inflamación/tratamiento farmacológico , Interferón gamma/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , L-Lactato Deshidrogenasa/metabolismo , Hígado/lesiones , Ratones , Ratones Endogámicos BALB C , Óxido Nítrico Sintasa de Tipo II/metabolismo , ARN Mensajero/metabolismo , Temperatura , Factor de Necrosis Tumoral alfa/metabolismo
10.
Int J Rheum Dis ; 14(3): e33-7, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21816011

RESUMEN

Since the discovery of the inflammasome, interleukin 1 production has been found to be integral in the pathophysiology of gout. Interleukin 1 inhibition by Anakinra has been shown to effective for the treatment of gout. We report three cases of resistant chronic tophaceous gout who responded to anakinra subcutaneous injections on an intermittent basis.


Asunto(s)
Supresores de la Gota/uso terapéutico , Gota/tratamiento farmacológico , Proteína Antagonista del Receptor de Interleucina 1/uso terapéutico , Interleucina-1/antagonistas & inhibidores , Enfermedad Aguda , Anciano , Alopurinol/uso terapéutico , Antiinflamatorios no Esteroideos/uso terapéutico , Enfermedad Crónica , Colchicina/uso terapéutico , Resistencia a Medicamentos/efectos de los fármacos , Gota/metabolismo , Gota/fisiopatología , Humanos , Inyecciones Subcutáneas , Interleucina-1/metabolismo , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
11.
J Environ Sci Health B ; 45(4): 315-24, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20401783

RESUMEN

Gas chromatography with nitrogen phosphorus detector (GC-NPD) was applied to the simultaneous determination of 15 organophosphorus and 6 organonitrogen pesticides residues in Angelica sinensis. The pesticides were extracted by microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) techniques, respectively. The experimental variables were optimized through orthogonal array experimental design. Cleanup of extracts was performed with column chromatography using florisil and neutral aluminum as the sorbents. The determination of pesticides in the final extracts was carried out by GC-NPD. Under optimized conditions, the average recoveries obtained from MAE and UAE are in the range of 75.1-129% and 70.6-129%, respectively, and the relative standard deviations of MAE and UAE were 3.1-10.6% and 1.0-17.8%, respectively.


Asunto(s)
Angelica sinensis/química , Compuestos de Nitrógeno/análisis , Compuestos Organofosforados/análisis , Residuos de Plaguicidas/análisis , Cromatografía de Gases y Espectrometría de Masas , Microondas , Estándares de Referencia , Reproducibilidad de los Resultados , Ultrasonido
12.
Am J Respir Cell Mol Biol ; 40(1): 76-82, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18635817

RESUMEN

Previous studies from our lab have demonstrated that upon exposure to physiologic levels of cyclic stretch, alveolar epithelial cells demonstrate a significant decrease in the amount of polymerized tubulin (Geiger et al., Gene Therapy 2006;13:725-731). However, not all microtubules are disassembled, although the mechanisms or implications of this were unknown. Using immunofluorescence microscopy, Western blotting, and immunohistochemistry approaches, we have compared the levels of acetylated tubulin in stretched and unstretched A549 cells and in murine lungs. In cultured cells exposed to cyclic stretch (10% change in basement membrane surface area at 0.25 Hz), nearly all of the remaining microtubules were acetylated, as demonstrated using immunofluorescence microscopy. In murine lungs ventilated for 20 minutes at 12 to 20 ml/kg followed by 48 hours of spontaneous breathing or for 3 hours at 16 to 40 ml/kg, levels of acetylated tubulin were increased in the peripheral lung. In both our in vitro and in vivo studies, we have found that mild to moderate levels of cyclic stretch significantly increases tubulin acetylation in a magnitude- and duration-dependent manner. This appears to be due to a decrease in histone deacetylase 6 activity (HDAC6), the major tubulin deacetylase. Since it has been previously shown that acetylated microtubules are positively correlated to a more stable population of microtubules, this result suggests that microtubule stability may be increased by cyclic stretch, and that tubulin acetylation is one way in which cells respond to changes in exogenous mechanical forces.


Asunto(s)
Histona Desacetilasas/metabolismo , Pulmón , Microtúbulos/metabolismo , Tubulina (Proteína)/metabolismo , Acetilación , Animales , Células Cultivadas , Elasticidad , Células Epiteliales/citología , Células Epiteliales/fisiología , Femenino , Histona Desacetilasa 6 , Histona Desacetilasas/genética , Humanos , Pulmón/citología , Pulmón/metabolismo , Ratones , Ratones Endogámicos BALB C , Periodicidad , Respiración con Presión Positiva , Alveolos Pulmonares/citología , Mucosa Respiratoria/citología , Estrés Mecánico , Transcripción Genética , Tubulina (Proteína)/genética
13.
Theor Appl Genet ; 117(3): 369-82, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18481043

RESUMEN

Sorghum ergot, caused predominantly by Claviceps africana Frederickson, Mantle, de Milliano, is a significant threat to the sorghum industry worldwide. The objectives of this study were firstly, to identify molecular markers linked to ergot resistance and to two pollen traits, pollen quantity (PQ) and pollen viability (PV), and secondly, to assess the relationship between the two pollen traits and ergot resistance in sorghum. A genetic linkage map of sorghum RIL population R931945-2-2 x IS 8525 (resistance source) was constructed using 303 markers including 36 SSR, 117 AFLP , 148 DArT and two morphological trait loci. Composite interval mapping identified nine, five, and four QTL linked to molecular markers for percentage ergot infection (PCERGOT), PQ and PV, respectively, at a LOD >2.0. Co-location/linkage of QTL were identified on four chromosomes while other QTL for the three traits mapped independently, indicating that both pollen and non pollen-based mechanisms of ergot resistance were operating in this sorghum population. Of the nine QTL identified for PCERGOT, five were identified using the overall data set while four were specific to the group data sets defined by temperature and humidity. QTL identified on SBI-02 and SBI-06 were further validated in additional populations. This is the first report of QTL associated with ergot resistance in sorghum. The markers reported herein could be used for marker-assisted selection for this important disease of sorghum.


Asunto(s)
Claviceps/fisiología , Inmunidad Innata/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Sitios de Carácter Cuantitativo/genética , Sorghum/genética , Sorghum/microbiología , Supervivencia Celular , Cromosomas de las Plantas/genética , Cruzamientos Genéticos , Ambiente , Epistasis Genética , Ligamiento Genético , Endogamia , Fenotipo , Enfermedades de las Plantas/microbiología , Polen/citología , Polen/genética , Carácter Cuantitativo Heredable , Reproducibilidad de los Resultados , Sorghum/inmunología
14.
Macromol Biosci ; 4(7): 665-73, 2004 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-15468260

RESUMEN

For use in micro-patterned scaffolds in tissue engineering, novel diacrylated triblock macromers (PLA-b-PCL-b-PLA, PGA-b-PCL-b-PGA and PCL-b-PEO-b-PCL) were synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR) and gel permeation chromatography (GPC). All diacrylated polymers were designed as triblock copolymers and involved biodegradable blocks of relatively non-polar epsilon-caprolactone (CL) and polar monomers such as glycolide (GA), lactide (LA) or ethylene oxide (EO). All triblock polymers were prepared in molecular weights of a few kilo daltons via the anionic ring-opening polymerization (ROP) of the corresponding lactide, glycolide or caprolactone using stannous octoate [Sn(Oct)(2)] as catalyst. The polymers had low polydispersity indices, ranging from 1.23 to 1.56. Biodegradable polymeric networks were prepared with conversions of 72-84% via photopolymerization of the triblock diacrylated polymers with 2,2-dimethoxy-2-phenylacetophenone (DMPA) as photoinitiator. PLA-b-PCL-b-PLA copolymers crumbled easily and were not suitable for micro-patterning. PGA-b-PCL-b-PGA copolymers had higher water contact angles than PCL-b-PEO-b-PCL and were also cytocompatible with Fibroblasts 3T3.


Asunto(s)
Polímeros/síntesis química , Ingeniería de Tejidos , Células 3T3 , Animales , Biodegradación Ambiental , Medios de Cultivo , Espectroscopía de Resonancia Magnética , Ratones , Peso Molecular , Polímeros/química , Propiedades de Superficie
15.
J Chromatogr A ; 927(1-2): 91-6, 2001 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-11572401

RESUMEN

In order to find a versatile high speed counter-current chromatography solvent system that can be used as a general prefractionation system for most alkaloids, the crude extracts of five Chinese traditional medicinal herbs, Cortex phellodendri, Semen strychni, green tea, Sophora flavescens ait, and Datura mete L. were resolved. All separations were performed only with a two-phase system composed of CHCl3-CH3OH-water (4:3:2). The water had different acidities controlled by adding NaH2PO4 or HCl to each sample. The fractionated components were identified by thin-layer chromatography, which confirmed this solvent system was versatile and very useful for the separation of alkaloids.


Asunto(s)
Alcaloides/aislamiento & purificación , Distribución en Contracorriente/métodos , Medicamentos Herbarios Chinos/química , Cromatografía en Capa Delgada , Solventes
16.
J Gen Virol ; 78 ( Pt 10): 2497-501, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9349470

RESUMEN

We have demonstrated that COS7 cells transiently co-expressing myristylation-defective (Myr-) and protease-defective (PR-) human immunodeficiency virus (HIV) mutants can release infectious virions when co-transfected with an amphotropic murine leukaemia virus envelope protein expression plasmid (SV-A-MLV-env). In contrast, no infectious virions were detected when a PR-, noninfectious HIV gag mutant was co-expressed with the Myr- mutant, although the Myr- mutant could still process the immature core particles in trans. This result indicates that generation of functionally normal Gag proteins is required for virus infectivity in our complementation system. A mutant with a 56-amino-acid deletion in the N-terminal region of the capsid (CA) domain could still complement the PR- mutant to generate infectious virions, suggesting that the deletion mutant could provide a functional protease for processing in the PR- mutant. This result is consistent with the concept that mutations within the N-terminal region of the CA domain have no major effects on Gag-Pol incorporation into particles.


Asunto(s)
Productos del Gen gag/metabolismo , Genes gag , VIH-1/crecimiento & desarrollo , Precursores de Proteínas/metabolismo , Animales , Células COS , Productos del Gen gag/genética , Prueba de Complementación Genética , Proteasa del VIH/fisiología , VIH-1/genética , Virus de la Leucemia Murina , Mutación , Ácidos Mirísticos/metabolismo , Precursores de Proteínas/genética , Procesamiento Proteico-Postraduccional , Transfección , Virión/ultraestructura
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