Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
Medicine (Baltimore) ; 103(23): e38487, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38847733

RESUMEN

Lung cancer is one of the most malignant tumors with fastest morbidity and mortality. Small cell lung cancer (SCLC) is the most malignant pathological type of lung cancer with early metastasis and poor prognosis. At present, there is a lack of effective indicators to predict prognosis of SCLC patients. Delta-like 3 protein (DLL3) is selectively expressed on the surface of SCLC and is involved in proliferation and invasion. Neuron-specific enolase (NSE) is an enolase isoenzyme that is generally regarded as a biomarker for SCLC and may correlate with stage of SCLC, prognosis and chemotherapy response. NSE can be influenced by different types of factors. To explore the associations between expression levels of DLL3 in tumor tissues with platinum/etoposide chemotherapy response, and assess the prognostic values of DLL3, NSE and other potential prognostic factors in advanced SCLC patients were herein studied. Ninety-seven patients diagnosed with SCLC in Zhongda Hospital from 2014 to 2020 were enrolled in the study. Serum NSE levels were tested using ELISA methods before any treatment. The expression of DLL3 in tumor tissue was detected by Immunohistochemistry (IHC). We investigated the relationship of DLL3 expression with chemotherapy and survival. Progression free survival (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method. Multivariate Cox-proportional hazard regression was used to identify predictors of PFS and OS. DLL3 was detected in 84.5% (82/97) of all patients' tumor samples by IHC, mainly located on the surface of SCLC cells. Lower DLL3 expression was associated with longer PFS and better chemotherapy response. OS had no significant differences. Multivariate analysis by Cox Hazard model showed that, high DLL3 expression and maximum tumor size >5 cm were independent risk factors for PFS, where NSE < 35 ng/mL and age < 70 were independent prognostic factors for OS. Early stage was independent prognostic factors for PFS and OS (P < .05 log-rank). DLL3 was expressed in the most of SCLCs. DLL3 expression level in the tumor and NSE level in the serum may be useful biomarkers to predict the prognosis of SCLC. DLL3 may be a potential therapeutic target for SCLC in the future.


Asunto(s)
Biomarcadores de Tumor , Neoplasias Pulmonares , Fosfopiruvato Hidratasa , Carcinoma Pulmonar de Células Pequeñas , Humanos , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Carcinoma Pulmonar de Células Pequeñas/sangre , Carcinoma Pulmonar de Células Pequeñas/mortalidad , Carcinoma Pulmonar de Células Pequeñas/patología , Masculino , Femenino , Fosfopiruvato Hidratasa/sangre , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/sangre , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/mortalidad , Persona de Mediana Edad , Pronóstico , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/metabolismo , Anciano , Proteínas de la Membrana/sangre , Proteínas de la Membrana/metabolismo , Péptidos y Proteínas de Señalización Intracelular/sangre , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Etopósido/uso terapéutico , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Valor Predictivo de las Pruebas , Estimación de Kaplan-Meier
3.
Case Rep Oncol ; 17(1): 101-106, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38229975

RESUMEN

Introduction: Primary pleural epithelial angiosarcoma (EAS) is an extremely rare tumor with no specific clinical symptoms. Clinical data on primary pleural EAS are limited, and misdiagnosis often occurs. Case Presentation: The present study reports the case of a 31-year-old patient diagnosed with primary pleural EAS with lung and bone metastases. The patient presented with persistent right chest pain for 5 months and dyspnea for 2 months. Chest computed tomography (CT) scan revealed right hydropneumothorax, diffuse thickening of the right pleura, passive atelectasis, and scattered nodules in the left lung. A medical thoracoscopic pleural biopsy revealed a vasogenic tumor. To further confirm the diagnosis, positron emission tomography/CT (PET/CT) examination was recommended to determine the biopsy site after multidisciplinary discussion. Increased 18F-FDG uptake in the right pleura and hypermetabolic nodules in the right chest wall, first lumbar vertebrae, second sacral vertebrae, and bilateral iliac crest was detected via PET/CT. CT-guided chest wall and lung biopsies were performed. Immunohistochemistry of specific markers was performed according to remote consultation with a pathologist, and tumor cells with strong positive expression of CD31, CD34, and ETS-related genes led to the final diagnosis of primary pleural EAS. Conclusion: Primary pleural EAS should be considered for hydropneumothorax of an unknown cause. PET/CT can accurately locate the lesion. The pathological examination is the basis for primary pleural EAS diagnosis. Moreover, multidisciplinary discussion and remote expert consultation can improve the diagnosis rate of primary pleural EAS.

4.
PLoS One ; 18(11): e0295082, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38015883

RESUMEN

BACKGROUND: Previous studies have found that the persistence of herpesvirus significantly increases the risk of idiopathic pulmonary fibrosis (IPF), but it is unclear whether this effect is causal. We conducted a two-sample Mendelian randomization (MR) study to evaluate the causal relationship between three herpesvirus infections and IPF. METHODS: We used genome-wide association studies (GWAS) data from three independent datasets, including FinnGen cohort, Milieu Intérieur cohort, and 23andMe cohort, to screen for instrumental variables (IVs) of herpesvirus infection or herpesvirus-related immunoglobulin G (IgG) levels. Outcome dataset came from the largest meta-analysis of IPF susceptibility currently available. RESULTS: In the FinnGen cohort, genetically predicted Epstein-Barr virus (EBV) (OR = 1.105, 95%CI: 0.897-1.149, p = 0.815), cytomegalovirus (CMV) (OR = 1.073, 95%CI: 0.926-1.244, p = 0.302) and herpes simplex (HSV) infection (OR = 0.906, 95%CI: 0.753-1.097, p = 0.298) were not associated with the risk of IPF. In the Milieu Intérieur cohort, we found no correlations between herpesvirus-related IgG EBV nuclear antigen-1 (EBNA1) (OR = 0.968, 95%CI: 0.782-1.198, p = 0.764), EBV viral capsid antigen (VCA) (OR = 1.061, 95CI%: 0.811-1.387, p = 0.665), CMV (OR = 1.108, 95CI%: 0.944-1.314, p = 0.240), HSV-1 (OR = 1.154, 95%CI: 0.684-1.945, p = 0.592) and HSV-2 (OR = 0.915, 95%CI: 0.793-1.056, p = 0.225) and IPF risk. Moreover, in the 23andMe cohort, no evidence of associations between mononucleosis (OR = 1.042, 95%CI: 0.709-1.532, p = 0.832) and cold scores (OR = 0.906, 95%CI: 0.603-1.362, p = 0.635) and IPF were found. Sensitivity analysis confirmed the robustness of our results. CONCLUSIONS: This study provides preliminary evidence that EBV, CMV, and HSV herpesviruses, and herpesviruses-related IgG levels, are not causally linked to IPF. Further MR analysis will be necessary when stronger instrument variables and GWAS with larger sample sizes become available.


Asunto(s)
Infecciones por Citomegalovirus , Infecciones por Virus de Epstein-Barr , Herpes Simple , Infecciones por Herpesviridae , Herpesviridae , Herpesvirus Humano 1 , Fibrosis Pulmonar Idiopática , Humanos , Herpesvirus Humano 4/genética , Infecciones por Virus de Epstein-Barr/complicaciones , Estudio de Asociación del Genoma Completo , Análisis de la Aleatorización Mendeliana , Infecciones por Herpesviridae/complicaciones , Infecciones por Herpesviridae/genética , Herpesviridae/genética , Herpes Simple/complicaciones , Citomegalovirus , Fibrosis Pulmonar Idiopática/genética , Fibrosis Pulmonar Idiopática/complicaciones , Inmunoglobulina G
5.
Front Cell Infect Microbiol ; 13: 1106859, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37091676

RESUMEN

Background: Clinical values of metagenomic next-generation sequencing (mNGS) in patients with severe pneumonia remain controversial. Therefore, we conduct this meta-analysis to evaluate the diagnostic performance of mNGS for pathogen detection and its role in the prognosis of severe pneumonia. Methods: We systematically searched the literature published in PubMed, Embase, Cochrane Library, Web of Science, Clinical Trials.gov, CNKI, Wanfang Data, and CBM from the inception to the 28th September 2022. Relevant trials comparing mNGS with conventional methods applied to patients with severe pneumonia were included. The primary outcomes of this study were the pathogen-positive rate, the 28-day mortality, and the 90-day mortality; secondary outcomes included the duration of mechanical ventilation, the length of hospital stay, and the length of stay in the ICU. Results: Totally, 24 publications with 3220 patients met the inclusion criteria and were enrolled in this study. Compared with conventional methods (45.78%, 705/1540), mNGS (80.48%, 1233/1532) significantly increased the positive rate of pathogen detection [OR = 6.81, 95% CI (4.59, 10.11, P < 0.001]. The pooled 28-day and 90-day mortality in mNGS group were 15.08% (38/252) and 22.36% (36/161), respectively, which were significantly lower than those in conventional methods group 33.05% (117/354) [OR = 0.35, 95% CI (0.23, 0.55), P < 0.001, I2 = 0%] and 43.43%(109/251) [OR = 0.34, 95% CI (0.21, 0.54), P < 0.001]. Meanwhile, adjusted treatment based on the results of mNGS shortened the length of hospital stay [MD = -2.76, 95% CI (- 3.56, - 1.96), P < 0.001] and the length of stay in ICU [MD = -4.11, 95% CI (- 5.35, - 2.87), P < 0.001]. Conclusion: The pathogen detection positive rate of mNGS was much higher than that of conventional methods. Adjusted treatment based on mNGS results can reduce the 28-day and 90-day mortality of patients with severe pneumonia, and shorten the length of hospital and ICU stay. Therefore, mNGS advised to be applied to severe pneumonia patients as early as possible in addition to conventional methods to improve the prognosis and reduce the length of hospital stay.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Neumonía , Humanos , Hospitales , Metagenoma , Metagenómica , Neumonía/diagnóstico , Sensibilidad y Especificidad
6.
Medicine (Baltimore) ; 102(14): e33405, 2023 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-37026937

RESUMEN

RATIONALE: Airway stents have been developed rapidly to treat airway stenosis and fistula caused by various reasons. Malignant conditions that lead to central airway obstruction, especially the invasion of trachea carina and formation of esophageal fistula, are still a challenge for clinicians. PATIENT CONCERNS: A 61-year-old man presented with malignant airway obstruction and fistula between trachea carina and esophagus accompanied by severe respiratory failure. DIAGNOSIS: The patient was clinically diagnosed with esophageal squamous cell cancer of stage IV, carina esophageal fistula, severe pneumonia, hypoproteinemia. INTERVENTIONS: Y-shaped covered metallic stent and Y-type silicone stent (hybrid stent) were placed in the airway to increase tracheal patency, block the fistula and perform carinal plasty. OUTCOMES: The clinical symptoms of the patient improved rapidly and the lung infection was controlled effectively. This patient was followed up for more than 2 month, and the quality of life was better than before. LESSONS: Hybrid stent can be used as 1 of options for airway reconstruction and palliative treatment for patients with complex airway diseases caused by malignant tumors.


Asunto(s)
Obstrucción de las Vías Aéreas , Fístula Esofágica , Neoplasias Esofágicas , Masculino , Humanos , Persona de Mediana Edad , Tráquea/cirugía , Calidad de Vida , Obstrucción de las Vías Aéreas/etiología , Obstrucción de las Vías Aéreas/cirugía , Fístula Esofágica/cirugía , Fístula Esofágica/complicaciones , Stents/efectos adversos , Resultado del Tratamiento , Neoplasias Esofágicas/complicaciones , Neoplasias Esofágicas/cirugía
7.
Front Immunol ; 13: 1088130, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36713441

RESUMEN

Acinetobacter baumannii is a gram-negative bacterium and a crucial opportunistic pathogen in hospitals. A. baumannii infection has become a challenging problem in clinical practice due to the increasing number of multidrug-resistant strains and their prevalence worldwide. Vaccines are effective tools to prevent and control A. baumannii infection. Many researchers are studying subunit vaccines against A. baumannii. Subunit vaccines have the advantages of high purity, safety, and stability, ease of production, and highly targeted induced immune responses. To date, no A. baumannii subunit vaccine candidate has entered clinical trials. This may be related to the easy degradation of subunit vaccines in vivo and weak immunogenicity. Using adjuvants or delivery vehicles to prepare subunit vaccines can slow down degradation and improve immunogenicity. The common immunization routes include intramuscular injection, subcutaneous injection, intraperitoneal injection and mucosal vaccination. The appropriate immunization method can also enhance the immune effect of subunit vaccines. Therefore, selecting an appropriate adjuvant and immunization method is essential for subunit vaccine research. This review summarizes the past exploration of A. baumannii subunit vaccines, hoping to guide current and future research on these vaccines.


Asunto(s)
Acinetobacter baumannii , Inmunización/métodos , Vacunación/métodos , Adyuvantes Inmunológicos/farmacología , Vacunas de Subunidad/farmacología
8.
Surgery ; 168(5): 909-914, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32792099

RESUMEN

BACKGROUND: This study investigates the clinical outcomes of endovenous microwave ablation and endovenous laser ablation for varicose veins. METHODS: A total of 139 patients who underwent endovenous microwave ablation and 145 patients who underwent endovenous laser ablation were included in this multicenter study. The clinical outcomes and complications were assessed at 1, 6, and 12 months after the procedure. The effect on quality of life was assessed by the Aberdeen Varicose Vein Questionnaire and the EuroQol Group 5-Dimension Self-Report Questionnaire. RESULTS: The endovenous microwave ablation group had a shorter procedure time than the endovenous laser ablation group (42.58 ± 15.62 minutes vs 65.46 ± 24.38 minutes, P < .01), and no significant differences were observed in the other procedure parameters. The incidences of induration (20.26% vs 31.06%) and ecchymosis (13.07% vs 22.98%, P < .05) were lower in the endovenous microwave ablation group. The rates of temporary paresthesia (9.80% vs 18.01%) and residual varicosities (8.61% vs 16.77%, P < .05) were lower in the endovenous microwave ablation group at 1 month. There were no significant differences in paresthesia or saphenous vein closure rates between the groups at 6 and 12 months. Both groups had significant improvements in their Aberdeen Varicose Vein Questionnaire and EuroQol Group 5-Dimension Self-Report Questionnaire scores post-procedure, and no significant differences in Aberdeen Varicose Vein Questionnaire and EuroQol Group 5-Dimension Self-Report Questionnaire scores were confirmed. However, local recurrence below the knee was lower in the endovenous microwave ablation group (2.34% vs 8.46%, P < .05) after 12 months. CONCLUSION: Our results confirmed that the endovenous microwave ablation procedure demonstrated a shorter procedure time, lower complication, and local recurrence than the endovenous laser ablation procedure.


Asunto(s)
Técnicas de Ablación/métodos , Terapia por Láser/métodos , Microondas/uso terapéutico , Várices/cirugía , Técnicas de Ablación/efectos adversos , Adulto , Femenino , Estudios de Seguimiento , Humanos , Terapia por Láser/efectos adversos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Calidad de Vida , Várices/psicología
9.
Mol Plant ; 12(2): 199-214, 2019 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-30639120

RESUMEN

Over the past few years, three photorespiratory bypasses have been introduced into plants, two of which led to observable increases in photosynthesis and biomass yield. However, most of the experiments were carried out using Arabidopsis under controlled environmental conditions, and the increases were only observed under low-light and short-day conditions. In this study, we designed a new photorespiratory bypass (called GOC bypass), characterized by no reducing equivalents being produced during a complete oxidation of glycolate into CO2 catalyzed by three rice-self-originating enzymes, i.e., glycolate oxidase, oxalate oxidase, and catalase. We successfully established this bypass in rice chloroplasts using a multi-gene assembly and transformation system. Transgenic rice plants carrying GOC bypass (GOC plants) showed significant increases in photosynthesis efficiency, biomass yield, and nitrogen content, as well as several other CO2-enriched phenotypes under both greenhouse and field conditions. Grain yield of GOC plants varied depending on seeding season and was increased significantly in the spring. We further demonstrated that GOC plants had significant advantages under high-light conditions and that the improvements in GOC plants resulted primarily from a photosynthetic CO2-concentrating effect rather than from improved energy balance. Taken together, our results reveal that engineering a newly designed chloroplastic photorespiratory bypass could increase photosynthetic efficiency and yield of rice plants grown in field conditions, particularly under high light.


Asunto(s)
Cloroplastos/metabolismo , Cloroplastos/efectos de la radiación , Ingeniería Genética , Luz , Oryza/citología , Oryza/genética , Fotosíntesis/genética , Dióxido de Carbono/metabolismo , Respiración de la Célula/genética , Respiración de la Célula/efectos de la radiación , Metabolismo Energético/genética , Metabolismo Energético/efectos de la radiación , Oryza/metabolismo , Oryza/efectos de la radiación , Fenotipo , Fotosíntesis/efectos de la radiación , Plantas Modificadas Genéticamente
10.
Sci Rep ; 7: 46231, 2017 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-28397859

RESUMEN

Various chloroplast transit peptides (CTP) have been used to successfully target some foreign proteins into chloroplasts, but for other proteins these same CTPs have reduced localization efficiencies or fail completely. The underlying cause of the failures remains an open question, and more effective CTPs are needed. In this study, we initially observed that two E.coli enzymes, EcTSR and EcGCL, failed to be targeted into rice chloroplasts by the commonly-used rice rbcS transit peptide (rCTP) and were subsequently degraded. Further analyses revealed that the N-terminal unfolded region of cargo proteins is critical for their localization capability, and that a length of about 20 amino acids is required to attain the maximum localization efficiency. We considered that the unfolded region may alleviate the steric hindrance produced by the cargo protein, by functioning as a spacer to which cytosolic translocators can bind. Based on this inference, an optimized CTP, named RC2, was constructed. Analyses showed that RC2 can more effectively target diverse proteins, including EcTSR and EcGCL, into rice chloroplasts. Collectively, our results provide further insight into the mechanism of CTP-mediated chloroplastic localization, and more importantly, RC2 can be widely applied in future chloroplastic metabolic engineering, particularly for crop plants.


Asunto(s)
Proteínas de Cloroplastos/metabolismo , Oryza/metabolismo , Secuencia de Aminoácidos , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Oryza/genética , Plantas Modificadas Genéticamente , Pliegue de Proteína , Señales de Clasificación de Proteína , Estructura Terciaria de Proteína , Transporte de Proteínas , Proteolisis , Protoplastos/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Ribulosa-Bifosfato Carboxilasa/metabolismo , Fracciones Subcelulares/metabolismo
11.
BMJ Open ; 6(8): e012227, 2016 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-27543591

RESUMEN

OBJECTIVES: To investigate and describe the epidemiological characteristics of suicide in the elderly in Jiading, Shanghai, for the period 2003-2013. DESIGN: Retrospective, observational, epidemiological study using routinely collected data. SETTING: Jiading District, Shanghai. METHODS: Suicide data were retrieved from the Shanghai Vital Registry database for the period 2003-2013. Crude and age-standardised mortality rates were calculated for various groups according to sex and age. Joinpoint regression was performed to estimate the percentage change (PC) and annual percentage change (APC) for suicide mortality. RESULT: A total of 956 deaths due to suicide occurred among people aged ≥65 years during the study period, accounting for 76.7% (956/1247) of all suicide decedents. Among the 956 people with suicide deaths, 88.7% (848/956) had a history of a psychiatric condition. The age-standardised mortality rates for suicide without and with a psychotic history in people aged ≥65 years were much higher than those for people aged <65 years in both genders. Suicide mortality in the elderly showed a declining trend, with a PC of -51.5% for men and -47.5% for women. The APC was -29.1 in 2003-2005, 4.6 in 2005-2008 and -9.7 in 2008-2013 for aged men, and -12.2 in 2003-2006 and -5.2 in 2006-2013 for aged women, respectively. Women living in Jiading had a higher risk of suicide death than men, especially among the elderly. The mortality rate for suicide increased with age in the elderly, and was more marked for those with a psychiatric history than for those without. CONCLUSIONS: Suicide mortality declined in Jiading during the study period 2003-2013 overall, but remained high in the elderly, especially those with a psychiatric history.


Asunto(s)
Suicidio/estadística & datos numéricos , Adulto , Anciano , Causas de Muerte , China/epidemiología , Femenino , Humanos , Masculino , Trastornos Mentales/mortalidad , Trastornos Mentales/psicología , Persona de Mediana Edad , Análisis de Regresión , Estudios Retrospectivos , Factores de Riesgo , Distribución por Sexo , Tasa de Supervivencia
12.
J Immunol ; 190(11): 5436-45, 2013 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-23616572

RESUMEN

Although modifier genes are extensively studied in various diseases, little is known about modifier genes that regulate autoimmune diseases. Autoimmune disease caused by the Fas(lpr) mutation depends on the genetic background of mouse strains, suggesting a crucial role of modifier genes. MRL/MpJ-Fas(lpr) (MRL/lpr) and AKR/lpr mice develop severe and mild lupus-like autoimmune disease, respectively, whereas this mutation does not cause disease on C57BL/6 (B6) or C3H background. Both MRL and AKR carry the same haplotype of the Cd72 gene encoding an inhibitory BCR coreceptor (CD72(c)), and CD72(c) contains several amino acid substitutions and a deletion in the extracellular region compared with CD72(a) and CD72(b). To address the role of Cd72(c) locus in the regulation of Fas(lpr)-induced autoimmune disease, we generated B6.CD72(c)/lpr and MRL.CD72(b)/lpr congenic mice. Introduction of the chromosomal interval containing Cd72(c) did not cause disease in B6 mice by itself, but caused development of lupus-like disease in the presence of Fas(lpr) on B6 background, clearly demonstrating that this interval contains the modifier gene that regulates Fas(lpr)-induced autoimmune disease. Conversely, MRL.CD72(b)/lpr congenic mice showed milder disease compared with MRL/lpr mice. We further demonstrated that Cd72(c) is a hypofunctional allele in BCR signal inhibition and that CD72 deficiency induces severe autoimmune disease in the presence of Fas(lpr). These results strongly suggest that the Cd72(c) is a crucial modifier gene that regulates Fas(lpr)-induced autoimmune disease due to its reduced activity of B cell signal regulation.


Asunto(s)
Antígenos CD/genética , Antígenos de Diferenciación de Linfocitos B/genética , Enfermedades Autoinmunes/genética , Enfermedades Autoinmunes/inmunología , Regulación de la Expresión Génica , Receptor fas/genética , Animales , Antígenos CD/inmunología , Antígenos de Diferenciación de Linfocitos B/inmunología , Autoanticuerpos/inmunología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Línea Celular , Femenino , Inmunofenotipificación , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/inmunología , Ganglios Linfáticos/citología , Ratones , Ratones Congénicos , Ratones Endogámicos MRL lpr , Ratones Noqueados , Mutación , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal , Bazo/citología , Receptor fas/inmunología
13.
Se Pu ; 31(11): 1076-80, 2013 Nov.
Artículo en Chino | MEDLINE | ID: mdl-24558843

RESUMEN

A novel method for simultaneous determination of eight organochlorine pesticides in solidification of floating organic drop coupled with gas chromatography-mass spectrometry (GC-MS) was established. A mixture of extractant (n-hexadecane) and dispersive agent (acetone) at the ratio of 1/5 (v/v) was injected into aqueous sample to form an emulsion and an extraction process was accomplished. The demulsifier (750 microL acetone) was then injected to break up the emulsion. The two phases were separated quickly without centrifugation. After being solidified in an ice-bath, the upper layer (n-hexadecane) was transferred into an Eppendorf tube and analyzed by GC-MS after melted at room temperature. Factors affecting extraction efficiency such as the type and volume of extractant, dispersive agent and demulsifier, also ionic strength and pH value of extraction system were studied. Under the optimized conditions, the working curve of the proposed method provided a good linearity in the range of 0.025-2.00 microg/L (r = 0.999 5-0.999 9). The detection limits of the organochlorine pesticides calculated by Hubaux-Vos method were 0.012-0.024 microg/L and the relative standard deviations (RSDs) ranged from 3.15% to 4.53%. The enrichment factors (EF) were 96-101. When the method was applied to the determination of farmland water, the average spiked recoveries were 96.77%-102.93% with the relative standard deviations of 2.68%-4.86%. The proposed method is sensitive and fast. It also has the advantage of little organic solvent consumption so that it is friendly to environment and suitable for batch analysis of organochlorine pesticides in aqueous samples. Meanwhile, it provides technical and methodological support for achieving the automation of sample pretreatment.


Asunto(s)
Cromatografía de Gases y Espectrometría de Masas , Hidrocarburos Clorados/análisis , Microextracción en Fase Líquida , Residuos de Plaguicidas/análisis , Contaminantes Químicos del Agua/análisis , Emulsiones , Solventes , Agua
14.
J Biol Chem ; 283(3): 1653-1659, 2008 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-18024433

RESUMEN

CD22, a B lymphocyte membrane glycoprotein, contains immunoreceptor tyrosine-based inhibition motifs (ITIMs) in the cytoplasmic region and recruits Src homology 2-containing protein-tyrosine phosphatase-1 (SHP-1) to the phosphorylated ITIMs upon ligation of B lymphocyte antigen receptor (BCR), thereby negatively regulating BCR signaling. Among the three previously identified ITIMs, both ITIMs containing tyrosine residues at position 843 (Tyr(843)) and 863 (Tyr(863)), respectively, are shown to be required for CD22 to recruit SHP-1 and regulate BCR signaling upon BCR ligation by anti-Ig antibody (Ab), indicating that CD22 has the SHP-1-binding domain at the region containing Tyr(843) and Tyr(863). Here we address the requirement of CD22 for SHP-1 recruitment and BCR regulation upon BCR ligation by antigen, which induces much stronger CD22 phosphorylation than anti-Ig Ab does. We demonstrate that the CD22 mutant in which both Tyr(843) and Tyr(863) are replaced by phenylalanine (CD22F5/6) recruits SHP-1 and regulates BCR signaling upon stimulation with antigen but not anti-Ig Ab. This result strongly suggests that CD22 contains another SHP-1 binding domain that is specifically activated upon stimulation with antigen. Both of the flanking sequences of Tyr(783) and Tyr(817) fit the consensus sequence of ITIM, and the CD22F5/6 mutant requires these tyrosine residues for SHP-1 binding and BCR regulation. Thus, these ITIMs constitute a novel conditional SHP-1-binding site of CD22 that is activated upon BCR ligation by antigen but not by anti-Ig Ab.


Asunto(s)
Linfocitos B/enzimología , Linfocitos B/inmunología , Activación de Linfocitos/inmunología , Proteína Tirosina Fosfatasa no Receptora Tipo 6/metabolismo , Lectina 2 Similar a Ig de Unión al Ácido Siálico/metabolismo , Secuencias de Aminoácidos , Animales , Anticuerpos/farmacología , Linfocitos B/efectos de los fármacos , Sitios de Unión , Línea Celular , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Activación de Linfocitos/efectos de los fármacos , Ratones , Proteínas Mutantes/metabolismo , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal/efectos de los fármacos , Especificidad por Sustrato/efectos de los fármacos , Tirosina/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...