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1.
Zhonghua Gan Zang Bing Za Zhi ; 32(6): 532-544, 2024 Jun 20.
Artículo en Chino | MEDLINE | ID: mdl-38964896

RESUMEN

Objective: To systematically evaluate the effect of hepatitis B virus (HBV) infection on the risk of adverse pregnancy outcomes. Methods: We searched PubMed, Embase, Web of Science, and Cochrane databases. Two researchers independently screened the literature, extracted data, and evaluated the quality. Meta-analysis and cumulative meta-analysis were performed using R4.4.1 software. Fixed/random effects models were used to analyze heterogeneous and non-heterogeneous results. Heterogeneous modifiers were identified by subgroup analysis. Funnel plots and Peters' test were used to analyze potential publication bias. Results: A total of 48 studies involving 92 836 HBsAg-positive pregnant women and 7 123 292 HBsAg-negative pregnant women were included. In terms of adverse pregnancy outcomes, HBV infection was significantly correlated with the occurrence of gestational diabetes mellitus [odds ratio (OR)=1.34, 95% confidence interval (CI): 1.17-1.53] and intrahepatic cholestasis (OR=2.48, 95%CI: 1.88-3.29), with statistically significant differences. In terms of adverse neonatal outcomes, HBV infection was significantly correlated with the occurrence of neonatal asphyxia (OR=1.49, 95%CI: 1.20-1.86) and preterm birth (OR=1.22, 95%CI: 1.12-1.33), with statistically significant differences. In addition, the cumulative meta-analysis demonstrated that the risk of gestational diabetes mellitus and preterm birth both tended to be stable in pregnant women with HBV infection following 2009 and 2010, respectively. The supplementary questions answered for repeated studies had limited significance. Conclusion: Intrahepatic cholestasis, gestational diabetes mellitus, neonatal asphyxia, and preterm birth occurrence risk can be raised with HBV infection in pregnant women.


Asunto(s)
Hepatitis B , Complicaciones Infecciosas del Embarazo , Resultado del Embarazo , Humanos , Embarazo , Femenino , Hepatitis B/epidemiología , Hepatitis B/complicaciones , Complicaciones Infecciosas del Embarazo/virología , Complicaciones Infecciosas del Embarazo/epidemiología , Virus de la Hepatitis B , Diabetes Gestacional/epidemiología , Nacimiento Prematuro/epidemiología , Recién Nacido , Colestasis Intrahepática/epidemiología , Factores de Riesgo
2.
Nan Fang Yi Ke Da Xue Xue Bao ; 44(3): 491-498, 2024 Mar 20.
Artículo en Chino | MEDLINE | ID: mdl-38597440

RESUMEN

OBJECTIVE: To investigate the risk factors of in-hospital mortality and establish a risk prediction model for patients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO). METHODS: We retrospectively collected the data of 302 patients receiving VA-ECMO in ICU of 3 hospitals in Guangdong Province between January, 2015 and January, 2022 using a convenience sampling method. The patients were divided into a derivation cohort (201 cases) and a validation cohort (101 cases). Univariate and multivariate logistic regression analyses were used to analyze the risk factors for in-hospital death of these patients, based on which a risk prediction model was established in the form of a nomogram. The receiver operator characteristic (ROC) curve, calibration curve and clinical decision curve were used to evaluate the discrimination ability, calibration and clinical validity of this model. RESULTS: The in-hospital mortality risk prediction model was established based the risk factors including hypertension (OR=3.694, 95% CI: 1.582-8.621), continuous renal replacement therapy (OR=9.661, 95%CI: 4.103-22.745), elevated Na2 + level (OR=1.048, 95% CI: 1.003-1.095) and increased hemoglobin level (OR=0.987, 95% CI: 0.977-0.998). In the derivation cohort, the area under the ROC curve (AUC) of this model was 0.829 (95% CI: 0.770-0.889), greater than those of the 4 single factors (all AUC < 0.800), APACHE II Score (AUC=0.777, 95% CI: 0.714-0.840) and the SOFA Score (AUC=0.721, 95% CI: 0.647-0.796). The results of internal validation showed that the AUC of the model was 0.774 (95% CI: 0.679-0.869), and the goodness of fit test showed a good fitting of this model (χ2=4.629, P>0.05). CONCLUSION: The risk prediction model for in-hospital mortality of patients on VA-ECMO has good differentiation, calibration and clinical effectiveness and outperforms the commonly used disease severity scoring system, and thus can be used for assessing disease severity and prognostic risk level in critically ill patients.


Asunto(s)
Oxigenación por Membrana Extracorpórea , Humanos , Estudios Retrospectivos , Mortalidad Hospitalaria , Oxigenación por Membrana Extracorpórea/métodos , Estudios de Casos y Controles , Pronóstico , Curva ROC
3.
Artículo en Chino | MEDLINE | ID: mdl-36992642

RESUMEN

Objective: To analyze the difference of application methods and effects of local flap in small and medium-sized defects of different aesthetic subunits of nose, in order to provide reference for clinical work. Methods: A retrospective analysis was made on 59 patients with external nasal masses and scars who underwent surgical treatment in the Department of Aesthetic Plastic Surgery of the Affiliated Hospital of Qingdao University from July 1, 2021 to January 30, 2022, including 27 females and 32 males, aged 15 to 69 years. Using Likert scale, the repair methods and effects of local flap for nasal soft tissue defects were evaluated and summarized from three aspects of texture, flatness and scar concealment. GraphPad Prism 5.0 software was used for data statistics and analysis. Results: The use of skin flaps to repair small and medium-sized areas of the nose could achieve satisfactory results. For patients with different subunits, in terms of skin flatness and scar concealment degree in the operation area, patients' satisfaction with the dorsal and lateral nasal areas was higher than that of the alar and tip areas, respectively (F=6.40, P=0.001; F=10.57, P<0.001). For patients with different skin flap repair methods, the satisfaction of patients with Z-plasty and Dufourmentel skin flap was higher than that of other skin flap repair methods (F=4.38, P=0.002), and the satisfaction of patients with Dufourmentel skin flap was the highest in the degree of scar concealment (F=2.57, P=0.038). Conclusions: In the small and medium-sized defects of the nose, the use of multiple local flaps can achieve good cosmetic effects and functional recovery. The operator should select the appropriate flap repair method according to the characteristics of different aesthetic subunits of the nose.

4.
Beijing Da Xue Xue Bao Yi Xue Ban ; 53(3): 479-484, 2021 Jun 18.
Artículo en Chino | MEDLINE | ID: mdl-34145848

RESUMEN

OBJECTIVE: To test the reliability and validity of the Chinese version of parenting sense of competence scale (PSOC) in Chinese mothers of preschool children, and to explore the perception of preschool children's mothers on their own parenting skills and their comfort of being a parent in Yanqing District of Beijing. METHODS: A cross-sectional survey was conducted using a convenience sample in 1 384 preschool children's mothers in Yanqing District of Beijing. SPSS 21.0 and Mplus 7.4 software were used for statistical analysis to test the structural validity, criterion related validity, internal consistency and split half reliability of the scale, and to analyze the score of the scale and its influencing factors. RESULTS: The PSOC had good reliability and validity. Exploratory factor analysis showed that each item of the PSOC had more than 0.4 factor loading in efficacy factor or satisfaction factor, and there was no double load phenomenon. Confirmatory factor analysis showed that the factor loadings ranged from 0.212 to 0.843 in efficacy factor and satisfaction factor, respectively. The goodness of fit test showed that all the fitting indexes were within the acceptable range, and the correlation between the effectiveness subscale and the satisfaction subscale was high. The Cronbach's α coefficient of the whole scale, the efficacy subscale and the satisfaction subscale were 0.872, 0.802, and 0.874, respectively. The Spearman-Brown coefficient of PSOC was 0.851. The average score of the whole scale, the efficacy subscale, and the satisfaction subscale were 72.33±11.31, 35.54±5.91, and 36.79±7.11, respectively, and the score of parenting competence in Chinese mothers of preschool children was influenced by the mother's educational level and the annual income of her family. CONCLUSION: The PSOC has satisfactory reliability and validity in Chinese mothers of preschool children. It can be used as an evaluation instrument for measuring the parenting competency, self perceived efficacy and satisfaction in the mainland Chinese mothers of preschool children. The competency of preschool children's mothers in Yanqing District of Beijing is very good, which may be related to the higher education level of the mothers and the higher annual income of their families in this study.


Asunto(s)
Madres , Responsabilidad Parental , Beijing , Preescolar , China , Estudios Transversales , Femenino , Humanos , Psicometría , Reproducibilidad de los Resultados , Encuestas y Cuestionarios
5.
Trop Biomed ; 38(1): 111-121, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33797533

RESUMEN

Chigger mites is a group of arthropods and some of them are vectors of scrub typhus. As a common synanthropic rodent species, the Brown rat (Rattus norvegicus) often harbors lots of ectoparasites including chigger mites. According to some "data mining" strategies, the present study took the advantage of the abundant original data from a long-term field ecological investigation between 2001 and 2015 to make a detailed analysis of chigger mites on R. norvegicus in Yunnan Province, Southwest of China. From 18 of 33 investigated counties, only 1414 chigger mites were collected from 1113 Brown rats with relatively low infestations. The 1414 individual chigger mites were identified as comprising 61 species, 11 genera and 2 subfamilies of the family Trombiculidae with a high species diversity (S=61, H'=3.13). Of 61 mite species, there were four main species, Walchia ewingi, Ascoschoengastia indica, W. koi and A. rattinorvegici, which accounted for 44.41% of the total mites. All the chigger mites were of aggregated distribution among different individuals of R. norvegicus. The Brown rats in the outdoor habitats harbored much more individuals and species of chigger mites with a higher mean abundance (MA=1.46) and mean intensity (MI=12.53) than in the indoor habitats (P<0.05). The overall infestation of the rats was significantly higher in the mountainous landscapes than in the flatland landscapes (P<0.001). The species similarity (Css) of the mites on the male and female rats reached 64.44% with sex biased infestations. The male rats harbored more species and individuals of the mites than the female rats. The adult rats harbored more species and individuals of the mites than the juvenile rats. The species abundance distribution of the mites was successfully fitted by Preston's lognormal model with s(R)=15e-[0.31(R-1)]2 (α=0.31, R2=0.95). On the basis of fitting the theoretical curve by Preston's model, the total mite species on R. norvegicus was estimated to be 86 species, and 25 rare mite species were missed in the sampling field investigation. The curve tendency of the species-plot relationship indicates that R. norvegicus have a great potential to harbor many species of chigger mites, and more species of the mites would be collected if more rats are sampled.


Asunto(s)
Infestaciones por Ácaros/veterinaria , Ratas/parasitología , Animales , China/epidemiología , Ecosistema , Femenino , Masculino , Infestaciones por Ácaros/epidemiología , Trombiculidae
6.
Tropical Biomedicine ; : 111-121, 2021.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-886262

RESUMEN

@#Chigger mites is a group of arthropods and some of them are vectors of scrub typhus. As a common synanthropic rodent species, the Brown rat (Rattus norvegicus) often harbors lots of ectoparasites including chigger mites. According to some “data mining” strategies, the present study took the advantage of the abundant original data from a long-term field ecological investigation between 2001 and 2015 to make a detailed analysis of chigger mites on R. norvegicus in Yunnan Province, Southwest of China. From 18 of 33 investigated counties, only 1414 chigger mites were collected from 1113 Brown rats with relatively low infestations. The 1414 individual chigger mites were identified as comprising 61 species, 11 genera and 2 subfamilies of the family Trombiculidae with a high species diversity (S=61, H’=3.13). Of 61 mite species, there were four main species, Walchia ewingi, Ascoschoengastia indica, W. koi and A. rattinorvegici, which accounted for 44.41% of the total mites. All the chigger mites were of aggregated distribution among different individuals of R. norvegicus. The Brown rats in the outdoor habitats harbored much more individuals and species of chigger mites with a higher mean abundance (MA=1.46) and mean intensity (MI=12.53) than in the indoor habitats (P<0.05). The overall infestation of the rats was significantly higher in the mountainous landscapes than in the flatland landscapes (P<0.001). The species similarity (Css) of the mites on the male and female rats reached 64.44% with sex biased infestations. The male rats harbored more species and individuals of the mites than the female rats. The adult rats harbored more species and individuals of the mites than the juvenile rats. The species abundance distribution of the mites was successfully fitted by Preston’s lognormal model with S

7.
Beijing Da Xue Xue Bao Yi Xue Ban ; 51(3): 525-529, 2019 Jun 18.
Artículo en Chino | MEDLINE | ID: mdl-31209426

RESUMEN

OBJECTIVE: To quantitatively analyze image quality of two sets of phantom (CatPhan504 and Cheese) Megavoltage computed tomography (MVCT) images acquired by Helical Tomotherapy with three scanning modes (Fine, Normal and Coarse), and to explore and validate a semi-automatic quality assurance procedure for MVCT images of Helical Tomotherapy. METHODS: On Helical Tomotherapy, CatPan504 and Cheese phantoms were scanned with three pitch levels (Fine, Normal, Coarse: 4 mm, 8 mm, 12 mm/circle) respectively. Pylinac, Matlab and Eclipse were used to calculate and compare spatial resolution, noise level and low contrast resolution of images obtained under three scanning modes respectively. The spatial resolution can be evaluated by the blurring of line-pair CT value in the images of CatPhan504's CTP528 module. The noise level can be evaluated by the integral non-uniformity in the images of Cheese's uniformity module. the low contrast resolution can be evaluated by contrast-to-noise ratio of both phantoms' plug-in module, or visibility of the region of interest (Supra-Slice) in the images of CatPhan504's CTP515 module. RESULTS: Analyses on CatPhan504's line pair module(CTP528 module) showed that the first three line pairs(the gap size are 0.500 cm, 0.250 cm and 0.167 cm respectively) could be clearly observed but blurring began to occur from the fourth line pair(the gap size is 0.125 cm) under Coarse mode. Meanwhile, the first four line pairs were all observable under the Normal and Fine modes. Integral non-integrity index(the value negatively correlated with the noise level) were 0.155 7, 0.136 8 and 0.122 9 for Coarse, Normal and Fine modes respectively. None of the Supra-Slice in CatPhan504's CTP515 module could be observed under three imaging modes. Low contrast contrast-to-noise ratio of Cheese phantom was similar under three modes and the insert visibility exhibited nearly linear growth with the increasing difference between CT average value of the insert material and background. CONCLUSION: Superiority and inferiority of three image modes in terms of the three image quality index was not consistent. Evaluation results above could provide reference for more rational decision on scanning modes selection of helical tomotherapy, which was based on image visualization demands in clinical practice. The proposed method could also provide guidance for similar image quality assessment and periodic quality assurance.


Asunto(s)
Radioterapia de Intensidad Modulada , Tomografía Computarizada de Haz Cónico , Fantasmas de Imagen , Tomografía Computarizada Espiral , Tomografía Computarizada por Rayos X
8.
Zhonghua Wai Ke Za Zhi ; 57(6): 466-470, 2019 Jun 01.
Artículo en Chino | MEDLINE | ID: mdl-31142072

RESUMEN

With the development of diagnostic and screening technologies, the incidence of hepatocellular carcinoma (HCC) with extrahepatic metastasis is increasing. It is a kind of refractory disease with extremely poor prognosis. Currently, there is no standard therapy. The existing guidelines only recommend targeted therapy, systemic chemotherapy or best supportive care for HCC patients with extrahepatic metastasis, but have not mentioned surgical therapy.Several studies have shown that the majority of HCC patients with extrahepatic metastasis died of progressive intrahepatic tumor leading to hepatic failure, but not extrahepatic metastases; and primary tumor resection may have a favorable impact on the prognosis of these patients with resectable primary tumors.Furthermore, the role of resection of metastatic tumors for HCC patients with extrahepatic metastasis remains unclear so far.Majority of experts think that resection of lung metastases has survival benefit when the hepatic lesion is resected or controlled, whereas resection of lymph nodes, bone metastases, adrenal gland lesions, or brain metastases does not prolong survival, which may be recommended when the goal is to relieve symptoms or improve quality of life.Therefore, surgical treatment is important for HCC patients with extrahepatic metastasis, and surgical therapy combined with personalized systemic treatment shows survival benefit for selected patients.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Neoplasias Hepáticas/cirugía , Neoplasias Pulmonares/cirugía , Carcinoma Hepatocelular/secundario , Humanos , Neoplasias Hepáticas/patología , Neoplasias Pulmonares/secundario , Metástasis de la Neoplasia , Pronóstico , Calidad de Vida , Estudios Retrospectivos
9.
Benef Microbes ; 9(5): 775-787, 2018 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-30014710

RESUMEN

Ulcerative colitis is a type of chronic inflammation present in the intestines for which the aetiology is not yet clear. The current therapies for ulcerative colitis cannot be considered to be long-term management strategies due to their significant side effects. Therefore, it is essential to identify an alternative therapeutic strategy for ulcerative colitis. The present study focused on the evaluation of the anti-inflammatory activities of Lactobacillus acidophilus CGMCC 7282 and Clostridium butyricum CGMCC 7281. The roles of both single and combination of L. acidophilus CGMCC 7282 and C. butyricum CGMCC 7281 in ulcerative colitis were investigated in 2,4,6-trinitrobenzenesulfonic acid-induced acute colitis (Th1-type colitis) in Sprague-Dawley rats and oxazolone-induced chronic colitis (Th2-type colitis) in BALB/c mice. The in vivo studies showed that the administration of L. acidophilus CGMCC 7282, C. butyricum CGMCC 7281 and L. acidophilus CGMCC 7282 plus C. butyricum CGMCC 7281 could reduce the Th1-type colitis as well as the Th2-type colitis, and the combination of the two strains exhibited the most notable effects, as indicated by the reduced mortality rates, the suppressed disease activity indices, the improved body weights, the reduced colon weight/colon length and colon weight/body weight ratios, and the improved gross anatomic characteristics and histological features (ameliorations of neutrophil infiltration and ulceration in the colon). It was found that the alterations of the gut microbiome, the barrier function changing and the selected inflammation-related cytokines are observed in the ulcerative colitis rats/mice treated with L. acidophilus CGMCC 7282 and C. butyricum CGMCC 7281. The combination of L. acidophilus CGMCC 7282 plus C. butyricum CGMCC 7281 also exerted a stronger anti-inflammatory effect than either of the single strains alone in vitro. These findings provide evidence that the administration of L. acidophilus CGMCC 7282 plus C. butyricum CGMCC 7281 may be a promising therapy for ulcerative colitis.


Asunto(s)
Clostridium butyricum/fisiología , Colitis Ulcerosa/tratamiento farmacológico , Intestinos/inmunología , Lactobacillus acidophilus/fisiología , Probióticos/administración & dosificación , Animales , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/genética , Colitis Ulcerosa/inmunología , Citocinas/genética , Citocinas/inmunología , Modelos Animales de Enfermedad , Microbioma Gastrointestinal , Humanos , Intestinos/microbiología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratas Sprague-Dawley , Células TH1/inmunología , Células Th2/inmunología , Ácido Trinitrobencenosulfónico/efectos adversos
10.
Artículo en Inglés | MEDLINE | ID: mdl-25768493

RESUMEN

We present experimental measurements of penetration depths for the impact of spheres into wetted granular media. We observe that the penetration depth in the liquid saturated case scales with projectile density, size, and drop height in a fashion consistent with the scaling observed in the dry case, but with smaller penetrations. Neither viscous drag nor density effects can explain the enhancement to the stopping force. The penetration depth exhibits a complicated dependence on liquid fraction, accompanied by a change in the drop-height dependence, that must be the consequence of accompanying changes in the conformation of the liquid phase in the interstices.

11.
Int J Data Min Bioinform ; 7(1): 22-37, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23437513

RESUMEN

Feature ranking, which ranks features via their individual importance, is one of the frequently used feature selection techniques. Traditional feature ranking criteria are apt to produce inconsistent ranking results even with light perturbations in training samples when applied to high dimensional and small-sized gene expression data, which brings troubles for further studies such as biomarker identification. A widely used strategy for solving the inconsistencies is the multicriterion combination, where score normalisation is crucial. In this paper, three problems in existing methods are first analyzed, and then a new feature importance transformation algorithm based on resampling and permutation is proposed for score normalisation. Experimental studies on four popular gene expression data sets show that the multi-criterion combination based on the proposed score normalisation produces gene rankings with improved robustness.


Asunto(s)
Algoritmos , Perfilación de la Expresión Génica , Análisis de Secuencia por Matrices de Oligonucleótidos , Reconocimiento de Normas Patrones Automatizadas
12.
Opt Express ; 20(18): 20096-101, 2012 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-23037062

RESUMEN

Land surface window emissivity is a key parameter for estimating the longwave radiative budget. The combined radiative transfer model (RM) with neural network (NN) algorithm is utilized to directly estimate the window (8-12 um) emissivity from the brightness temperature of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) with 90 m spatial resolution. Although the estimation accuracy is very high when the broadband emissivity is estimated from AST05 (ASTER Standard Data Product) by using regression method, the accuracy of AST05 is about ± 0.015 for 86 spectra which is determined by the atmosphere correction for ASTER 1B data. The MODTRAN 4 is used to simulate the process of radiance transfer, and the broadband emissivity is directly estimated from the brightness temperature of ASTER 1B data at satellite. The comparison analysis indicates that the RM-NN is more competent to estimate broadband emissivity than other method when the brightness temperatures of band 11, 12, 13, 14 are made as input nodes of dynamic neural network. The estimation average accuracy is about 0.009, and the estimation results are not sensitive to instrument noise. The RM-NN is applied to extract broadband emissivity from an image of ASTER 1B data in China, and the comparison against a classification based multiple bands with 15 m spatial resolution shows that the estimation results from RM-NN are very good.


Asunto(s)
Algoritmos , Atmósfera/análisis , Atmósfera/química , Interpretación Estadística de Datos , Redes Neurales de la Computación , Fotometría/métodos , Luz , Dispersión de Radiación
13.
Hum Exp Toxicol ; 31(9): 861-7, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22751198

RESUMEN

Trichloroethylene (TCE) is a common organic solvent that has been widely used in industrial applications. Hundred cases of allergic reactions occurred after the workers were occupationally exposed to TCE in China in the past decade, but the underlying effector mechanisms of TCE remain unclear. The purpose of the present study is to examine the alteration of hepatic metabolic enzyme gene and apoptosis-related gene messenger RNA (mRNA) expression in L02 human hepatocytes (L02 cells) after treatment with TCE. L02 cells were cultured either with various doses of TCE (0.25, 0.5, 1.0 and 2.0 mmol/L) for 24 h or with a single dose of TCE (1.0 mmol/L) for different time intervals, whereas samples treated with dimethyl sulfoxide served as control. Quantitative real-time polymerase chain reaction analysis was performed to detect the mRNA expression of hepatic metabolic enzyme genes (CYP1A2, CYP3A4 and CYP2E1) and apoptosis-related genes (BAX and BAD). It was found that the transcript levels of hepatic metabolic enzyme genes and apoptosis genes including BAX and BAD were significantly increased after TCE treatment at various doses for 24 h when compared with controls. Additionally, when the cells were treated with a single dose of TCE (1.0 mmol/L) for different periods of time (3, 6, 12 and 24 h), the mRNA expression of these genes also increased significantly compared with control (p < 0.05 or p < 0.01). The conclusion of the study is that TCE could induce alteration of mRNA expression of hepatic metabolic enzyme genes and apoptosis genes, which might be implicated in the effector mechanisms of TCE cytotoxicity in vivo.


Asunto(s)
Regulación de la Expresión Génica/efectos de los fármacos , Hepatocitos/efectos de los fármacos , Solventes/toxicidad , Tricloroetileno/toxicidad , Apoptosis/genética , Línea Celular , Supervivencia Celular/efectos de los fármacos , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP2E1/genética , Citocromo P-450 CYP3A/genética , Hepatocitos/metabolismo , Humanos , Hígado/metabolismo , ARN Mensajero/metabolismo , Proteína X Asociada a bcl-2/genética , Proteína Letal Asociada a bcl/genética
14.
Artículo en Inglés | MEDLINE | ID: mdl-21566255

RESUMEN

Feature selection often aims to select a compact feature subset to build a pattern classifier with reduced complexity, so as to achieve improved classification performance. From the perspective of pattern analysis, producing stable or robust solution is also a desired property of a feature selection algorithm. However, the issue of robustness is often overlooked in feature selection. In this study, we analyze the robustness issue existing in feature selection for high-dimensional and small-sized gene-expression data, and propose to improve robustness of feature selection algorithm by using multiple feature selection evaluation criteria. Based on this idea, a multicriterion fusion-based recursive feature elimination (MCF-RFE) algorithm is developed with the goal of improving both classification performance and stability of feature selection results. Experimental studies on five gene-expression data sets show that the MCF-RFE algorithm outperforms the commonly used benchmark feature selection algorithm SVM-RFE.


Asunto(s)
Algoritmos , Biología Computacional/métodos , Perfilación de la Expresión Génica/métodos , Análisis de Secuencia por Matrices de Oligonucleótidos , Reconocimiento de Normas Patrones Automatizadas/métodos , Inteligencia Artificial , Bases de Datos Genéticas , Humanos , Neoplasias/genética , Neoplasias/metabolismo
15.
Artículo en Inglés | MEDLINE | ID: mdl-20479500

RESUMEN

Mahalanobis class separability measure provides an effective evaluation of the discriminative power of a feature subset, and is widely used in feature selection. However, this measure is computationally intensive or even prohibitive when it is applied to gene expression data. In this study, a recursive approach to Mahalanobis measure evaluation is proposed, with the goal of reducing computational overhead. Instead of evaluating Mahalanobis measure directly in high-dimensional space, the recursive approach evaluates the measure through successive evaluations in 2D space. Because of its recursive nature, this approach is extremely efficient when it is combined with a forward search procedure. In addition, it is noted that gene subsets selected by Mahalanobis measure tend to overfit training data and generalize unsatisfactorily on unseen test data, due to small sample size in gene expression problems. To alleviate the overfitting problem, a regularized recursive Mahalanobis measure is proposed in this study, and guidelines on determination of regularization parameters are provided. Experimental studies on five gene expression problems show that the regularized recursive Mahalanobis measure substantially outperforms the nonregularized Mahalanobis measures and the benchmark recursive feature elimination (RFE) algorithm in all five problems.


Asunto(s)
Algoritmos , Biología Computacional/métodos , Minería de Datos/métodos , Perfilación de la Expresión Génica/métodos , Interpretación Estadística de Datos , Bases de Datos Genéticas , Humanos , Neoplasias/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Análisis de Regresión
16.
Diabetologia ; 54(3): 583-93, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21190012

RESUMEN

AIM/HYPOTHESIS: Neonatal beta cells lack glucose-stimulated insulin secretion and are thus functionally immature. We hypothesised that this lack of glucose responsiveness results from a generalised low expression of genes characteristic of mature functional beta cells. Important glucose-responsive transcription factors, Mafa and Pdx1, regulate genes involved in insulin synthesis and secretion, and have been implicated in late beta cell development. The aim of this study was to assess whether Mafa and/or Pdx1 regulates the postnatal functional maturation of beta cells. METHODS: By quantitative PCR we evaluated expression of these and other beta cell genes over the first month compared with adult. After infection with adenovirus expressing MAFA, Pdx1 or green fluorescent protein (Gfp), P2 rat islets were evaluated by RT-PCR and insulin secretion with static incubation and reverse haemolytic plaque assay (RHPA). RESULTS: At P2 most beta cell genes were expressed at about 10% of adult, but by P7 Pdx1 and Neurod1 no longer differ from adult; by contrast, Mafa expression remained significantly lower than adult through P21. Overexpression of Pdx1 increased Mafa, Neurod1, glucokinase (Gck) mRNA and insulin content but failed to enhance glucose responsiveness. Similar overexpression of MAFA resulted in increased Neurod1, Nkx6-1, Gck and Glp1r mRNAs and no change in insulin content but, importantly, acquisition of glucose-responsive insulin secretion. Both the percentage of secreting beta cells and the amount of insulin secreted per beta cell increased, approaching that of adult beta cells. CONCLUSIONS/INTERPRETATION: In the process of functional maturation acquiring glucose-responsive insulin secretion, neonatal beta cells undergo a coordinated gene expression programme in which Mafa plays a crucial role.


Asunto(s)
Células Secretoras de Insulina/metabolismo , Factores de Transcripción Maf de Gran Tamaño/metabolismo , Animales , Western Blotting , Femenino , Humanos , Técnicas In Vitro , Insulina/metabolismo , Factores de Transcripción Maf de Gran Tamaño/genética , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
17.
Opt Express ; 18(9): 9542-54, 2010 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-20588801

RESUMEN

An algorithm based on the radiance transfer model (RM) and a dynamic learning neural network (NN) for estimating water vapor content from moderate resolution imaging spectrometer (MODIS) 1B data is developed in this paper. The MODTRAN4 is used to simulate the sun-surface-sensor process with different conditions. The dynamic learning neural network is used to estimate water vapor content. Analysis of the simulation data indicates that the mean and standard deviation of estimation error are under 0.06 gcm(-2 )and 0.08 gcm(-2). The comparison analysis indicates that the estimation result by RM-NN is comparable to that of a MODIS water vapor content product (MYD05_L2). Finally, validation with ground measurement data shows that RM-NN can be used to accurately estimate the water vapor content from MODIS 1B data, and the mean and standard deviation of the estimation error are about 0.12 gcm(-2 )and 0.18 gcm(-2).

18.
Poult Sci ; 88(12): 2636-43, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19903963

RESUMEN

In the eggs of the quail Coturnix japonica, the limiting membrane demarcates the shell membrane at the interface with the albumen and decreases in width during the hatching process. This study was done to identify agents that affect the width of this limiting membrane. Zymography tests on extracts from extraembryonic tissues, yolk sacs, or chorioallantoic membranes, or all three, showed proteolytic activities during d 4 to 10 of incubation. Localization experiments on these activities, performed on d 5 eggs, indicated that they were located in an avascular chorion. Electron microscopic analysis showed there were secretory cells specifically located in the avascular chorion. After partial purification of d 5 avascular chorion extracts using QA52 and Sephadex G-200 column chromatography, the proteolytic activity of 20 kDa was isolated. The protease showed a high level of activity toward succinyl-Gly-Pro-Leu-Gly-Pro-4-methylcoumaryl-7-amide. It had an optimal pH of 9 and digested the limiting membrane. These enzymatic activities were inhibited moderately by EDTA and strongly by leupeptin and aprotinin. It was concluded that it is the 20-kDa protease, showing collagenase-like activity produced by the avascular chorion, that affects the limiting membrane.


Asunto(s)
Coturnix/embriología , Proteínas del Huevo/metabolismo , Membranas Extraembrionarias/metabolismo , Óvulo/enzimología , Péptido Hidrolasas/metabolismo , Animales , Membranas Extraembrionarias/ultraestructura
19.
Braz. j. med. biol. res ; 40(5): 621-631, May 2007. graf, ilus
Artículo en Inglés | LILACS | ID: lil-449091

RESUMEN

The tissue inhibitor of metalloproteinases (TIMP)-1 is a multifunctional protein which is not only an inhibitor of matrix metalloproteinases (MMPs) but also to have a possible "cytokine-like" action. Here, we first compared mRNA expression of TIMP-1 and MMP-9 in BEL-7402 (a hepatocellular carcinoma cell line), L-02 (a normal liver cell line) and QSG-7701 (a cell line derived from peripheral tissue of liver carcinoma) using real-time quantitative RT-PCR. By evaluating the variation of the MMP-9/TIMP-1 ratio as an index of reciprocal changes of the expression of the two genes, we observed that the MMP-9/TIMP-1 ratio was about 13- and 5-fold higher in BEL-7402 than in L-02 and QSG-7701, respectively. Significantly, overexpression of TIMP-1 decreased the MMP-9/TIMP-1 ratio in BEL-7402 and then inhibited the cell growth to 60 percent and reduced the migration to about 30 percent. Meanwhile, our data showed that interleukin-6 (IL-6) (100 ng/mL) could also inhibited the cell growth of BEL-7402. Further studies indicated that TIMP-1 mediated the inhibitory effect of IL-6 on BEL-7402 cell proliferation in a STAT3-dependent manner, which could further accelerate the expression of the cyclin-dependent kinase inhibitor p21. A dominant negative STAT3 mutant totally abolished IL-6-induced TIMP-1 expression and its biological functions. The present results demonstrate that TIMP-1 may be one of the mediators that regulate the inhibitory effect of IL-6 on BEL-7402 proliferation in which STAT3 signal transduction and p21 up-regulation also play important roles.


Asunto(s)
Humanos , Carcinoma Hepatocelular/genética , /genética , Neoplasias Hepáticas/genética , Metaloproteinasa 9 de la Matriz/genética , /genética , Inhibidor Tisular de Metaloproteinasa-1/genética , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , /metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Metaloproteinasa 9 de la Matriz/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal , /metabolismo , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Regulación hacia Arriba
20.
Braz J Med Biol Res ; 40(5): 621-31, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17464423

RESUMEN

The tissue inhibitor of metalloproteinases (TIMP)-1 is a multifunctional protein which is not only an inhibitor of matrix metalloproteinases (MMPs) but also to have a possible "cytokine-like" action. Here, we first compared mRNA expression of TIMP-1 and MMP-9 in BEL-7402 (a hepatocellular carcinoma cell line), L-02 (a normal liver cell line) and QSG-7701 (a cell line derived from peripheral tissue of liver carcinoma) using real-time quantitative RT-PCR. By evaluating the variation of the MMP-9/TIMP-1 ratio as an index of reciprocal changes of the expression of the two genes, we observed that the MMP-9/TIMP-1 ratio was about 13- and 5-fold higher in BEL-7402 than in L-02 and QSG-7701, respectively. Significantly, overexpression of TIMP-1 decreased the MMP-9/TIMP-1 ratio in BEL-7402 and then inhibited the cell growth to 60% and reduced the migration to about 30%. Meanwhile, our data showed that interleukin-6 (IL-6) (100 ng/mL) could also inhibited the cell growth of BEL-7402. Further studies indicated that TIMP-1 mediated the inhibitory effect of IL-6 on BEL-7402 cell proliferation in a STAT3-dependent manner, which could further accelerate the expression of the cyclin-dependent kinase inhibitor p21. A dominant negative STAT3 mutant totally abolished IL-6-induced TIMP-1 expression and its biological functions. The present results demonstrate that TIMP-1 may be one of the mediators that regulate the inhibitory effect of IL-6 on BEL-7402 proliferation in which STAT3 signal transduction and p21 up-regulation also play important roles.


Asunto(s)
Carcinoma Hepatocelular/genética , Interleucina-6/genética , Neoplasias Hepáticas/genética , Metaloproteinasa 9 de la Matriz/genética , Factor de Transcripción STAT3/genética , Inhibidor Tisular de Metaloproteinasa-1/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Humanos , Interleucina-6/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Metaloproteinasa 9 de la Matriz/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Regulación hacia Arriba
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