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ε-Poly-l-lysine (ε-PL) is a natural antimicrobial polymer with significant inhibitory activity against a broad spectrum of microorganisms, and nowadays used widely as a preservative in the food industry. In the present study, ε-PL broth was obtained from Streptomyces ahygroscopicus GIM8 fermentation in a nutrient-limited liquid medium. The in vitro antifungal activity of the broth against fruit pathogens Penicillium expansum and Colletotrichum gloeosporioides was investigated, and its usage for postharvest storage of two highly perishable fruits wax apple and guava was evaluated. Results showed that ε-PL concentration in the broth reached 0.61 g/L, and the nutrition level of the broth was low. The antifungal activity of ε-PL broth was comparable to that of the aqueous solution of ε-PL under the same concentration. Immersion with the diluted broth (200 mg/L ε-PL) markedly delayed the decline in the quality of postharvest wax apple and guava fruits during storage, and the decay incidences were also greatly decreased as compared to their respective controls (distilled water immersion). A further investigation demonstrated that the ε-PL broth immersion induced an increase in the activity of defense-related enzymes peroxidase and polyphenol oxidase in the two fruits during storage. The present study proved that the fermentation broth of ε-PL could be used as a promising alternative to high purity ε-PL and synthetic fungicides for preserving fruits at postharvest stage.
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Psidium , Streptomyces , Syzygium , Antifúngicos/farmacologia , Frutas/microbiologia , Polilisina/farmacologiaRESUMO
PURPOSE: Studies investigating the association between genetic polymorphism of cyclin D1 (CCND1) G870A and risk of colorectal cancer (CRC) reported conflicting results. In order to derive a more precise estimation of the relationship, a meta-analysis was performed. MATERIALS AND METHODS: We performed an extensive search of relevant studies and carried out a meta-analysis, including 20 studies with 5,975 cases and 8,333 controls, to obtain a more precise estimate. RESULTS: Overall, significantly elevated colorectal cancer risk was associated with variant allele 870A when all studies were pooled (AA vs. GG: OR = 1.23, 95% CI = 1.04-1.44; GA vs. GG: OR = 1.13, 95% CI = 1.01-1.26; dominant model: OR = 1.16, 95% CI = 1.03-1.31). In the subgroup analysis by ethnicity, significantly increased risks were detected among Caucasians (AA vs. GG: OR = 1.27, 95% CI = 1.04-1.44; dominant model: OR = 1.17, 95% CI = 1.02-1.34).We also observed sporadic CRC with an increased cancer susceptibility (AA vs. GG: OR = 1.24, 95% CI = 1.04-1.48; dominant model: OR = 1.17, 95% CI = 1.04-1.33), when colorectal cancer was stratified into sporadic CRC and hereditary nonpolyposis colorectal cancer (HNPCC). However, no significant associations were found in both Asians and HNPCC patients for all genetic models. CONCLUSION: Result suggests that the cyclin D1 870A allele is a low-penetrant risk factor for developing sporadic colorectal cancer, especially among Caucasians.
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Substituição de Aminoácidos/genética , Neoplasias Colorretais/genética , Ciclina D1/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único/genética , Genética Populacional , Humanos , Razão de Chances , Viés de Publicação , Fatores de RiscoRESUMO
OBJECTIVE: To evaluate the therapeutic efficacy and safety of liver transplantation for patients with cholangiocarcinoma. METHODS: According to the requirements of Cochrane systematic review, a thorough literature search was performed in Pubmed/Medline, Embase and Cochrane Central Register electronic databases ranged between 1995 and 2009 in terms of the key words "liver transplantation", and "cholangiocarcinoma" or "cholangiocellular carcinoma" or "bile duct cancer". And restricted the articles published in the English language. Two reviewers independently screened the studies for eligibility, evaluated the quality and extracted the data from the eligible studies with confirmation by cross-checking. Data were processed for a meta-analysis by Stata 10 software with 1-, 3-, 5-year survival rates and incidence of complications. RESULTS: A total of 14 clinical trials containing 605 patients were finally enrolled in this study. The overall 1-, 3-, 5-year pooled survival rates were 73% (95%CI: 0.65 - 0.80), 42% (95%CI: 0.33 - 0.51) and 39% (95%CI: 0.28 - 0.51), respectively. Of note, preoperative adjuvant therapies (OLT-PAT group) rendered the transplanted individuals comparably favorable outcomes with 1-, 3-, 5-year pooled survival rates of 83% (95%CI: 0.57 - 0.98), 57% (95%CI: 0.18 - 0.92) and 65% (95%CI: 0.40 - 0.87), respectively. In addition, the overall pooled incidence of complications was 62% (95%CI: 0.44 - 0.78), among which that of OLT-PAT group (58%, 95%CI: 0.20 - 0.92) was relatively acceptable compared to those of liver transplantation alone (61%, 95%CI: 0.33 - 0.85) and liver transplantation with extended bile duct resection (78%, 95%CI: 0.55 - 0.94). CONCLUSIONS: In comparison to curative resection of cholangiocarcinoma with the 5-year survival rate reported from 20% to 40%, the role of liver transplantation alone is so limited, but neoadjuvant radiochemotherapy combined with liver transplantation can bring better short- and long-term prognosis.
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Neoplasias dos Ductos Biliares/cirurgia , Colangiocarcinoma/cirurgia , Transplante de Fígado , Ensaios Clínicos como Assunto , Humanos , Resultado do TratamentoRESUMO
BACKGROUND: Breast-conserving surgery followed by radiotherapy is recommended in most women with early-stage unilateral breast cancer. However, its role in contralateral breast cancer (CBC) patients remains unclear. This retrospective study aimed to evaluate the breast cancer-specific survival (BCSS) outcomes after breast-conserving surgery plus radiotherapy compared with mastectomy in women with early-stage (T1-2N0-1M0) CBC. METHODS: Data were extracted from the Surveillance, Epidemiology, and End Results database. BCSS was analyzed using the log-rank method, competing risks regression model, and propensity score matching method. RESULTS: A total of 9,336 early-stage CBC patients were included. After multivariable adjustment, no significant difference in BCSS was found between early-stage CBC patients undergoing breast-conserving surgery plus radiotherapy and those undergoing mastectomy [hazard ratio (HR) 1.11, 95% confidence interval (CI): 0.90-1.37, P=0.329]. BCSS was similar in both treatment groups and in the subgroups stratified by age at first primary breast cancer or CBC diagnosis (≤50, 51-60, and >60 years), time interval between cancers (<0.25, 0.25-4, 5-9, and ≤10 years), stage of first primary breast cancer, T classification of CBC, histology and hormone receptors status of both cancers (all P>0.05). Among patients with N1 disease at CBC diagnosis, breast-conserving surgery plus radiotherapy was associated with a boundary significantly improved BCSS (HR 1.45, 95% CI: 1.00-2.12, P=0.050). Among patients who underwent breast-conserving surgery for first primary cancer, bilateral mastectomy for contralateral cancer did not improve BCSS compared with breast-conserving surgery plus radiotherapy (P>0.05). There was no significant difference in BCSS between breast-conserving surgery plus radiotherapy and mastectomy plus radiotherapy (P>0.05). Stable results were obtained after propensity score matching. CONCLUSIONS: Breast-conserving surgery plus radiotherapy did not significantly influence BCSS outcomes of patients with early-stage CBC. Bilateral mastectomy and mastectomy plus radiotherapy did not confer a survival advantage over breast-conserving surgery plus radiotherapy in these patients. Future prospective studies are necessary to expand on these results.
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The published data about thymidylate synthase (TS) expression and its predictive value in advanced colorectal cancer (CRC) patients receiving fluoropyrimidine-based chemotherapy seemed inconclusive. To derive a more precise estimation of the relationship, a metaanalysis was performed. Studies have been identified by searching PubMed and Embase. Inclusion criteria were advanced CRC patients, received fluoropyrimidine-based chemotherapy and evaluation of TS expression and overall response rate (ORR). The relative ratio (RR) for ORR in patients with low-TS expression over those with high-TS expression with 95% confidence interval (CI) was calculated for each study as an estimation of the predictive effect of TS. A total of 24 studies including 1,112 patients were involved in this metaanalysis. The overall RR was 2.20 (95% CI, 1.82-2.66; p = 0.000). For studies evaluating TS expression in metastatic lesions, the pooled RR was 3.23 (95% CI, 2.27-4.59; p = 0.000); for studies testing TS expression in primary lesions, a pooled RR of 1.89 (95% CI, 1.45-2.48; p = 0.000) was estimated. Focusing the analysis on immunohistochemistry (IHC)-based or RTPCR-based assessments, the pooled RR was 1.83 (95% CI, 1.44-2.34; p = 0.000) and 2.96 (95% CI, 2.07-4.22; p = 0.000), respectively. The results indicated that low-TS expression tumors in advanced CRC patients were more sensitive to fluoropyrimidine-based chemotherapy. Subgroup analyses indicated that the predictive value of TS expression evaluated in metastases was more prominent than that of primary lesions, and that TS expression tested by RTPCR was also of greater predictive value than by IHC.
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Antineoplásicos/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/enzimologia , Timidilato Sintase/metabolismo , Humanos , Imuno-Histoquímica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Acute pancreatitis is a common complication of endoscopic retrograde cholangiopancreatography (ERCP), and the benefit of pharmacologic treatment of the condition is unclear. Although prophylactic use of gabexate mesylate (GM) for the reduction of pancreatic injury after ERCP has been evaluated, uncertainty remains regarding the effectiveness of GM treatment in post-ERCP pancreatitis (PEP). OBJECTIVE: The aim of this study was to determine through systematic review and meta-analysis the effectiveness and tolerability of GM in the prophylaxis of PEP. METHODS: MEDLINE (January 1966-July 2007), EMBASE (January 1966- July 2007), the Cochrane Controlled Trials Register on The Cochrane Library (Issue 2, 2007), and the China Biological Medicine Database (January 1978-July 2007) were searched. We used the method recommended by The Cochrane Collaboration to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) of GM in the prevention of PEP. RESULTS: Of the 38 studies identified, 31 were excluded for the following reasons: they were reviews or editorials (9 articles); were meta-analyses (4); had differences in cointerventions (4); were nonrandomized controlled trials or had incorrect randomization (4); were repeat publications (2); lacked a placebo group (1); or other (7). Seven RCTs, totaling 2883 patients, conducted in a variety of languages were included in the meta-analysis. When the RCTs were analyzed, odds ratios for GM were 0.65 (95% CI, 0.36-1.18; P 0.16) for PER 1.90 (95% CI, 0.54-6.65; P 0.32) for severe PEP, 0.55 (95% CI, 0.17-1.77; P 0.32) for the case-fatality ratio of PEP, 0.88 (95% CI, 0.74-1.05; P 0.16) for post-ERCP hyperamylasemia, and 0.78 (95% CI, 0.49 1.25; P 0.30) for post-ERCP abdominal pain. No evidence of publication bias was found. CONCLUSIONS: No beneficial effects of GM on acute pancreatitis, the PEP mortality rate, or post-ERCP abdominal pain or hyperamylasemia were found; therefore, GM cannot be recommended for the prophylaxis of PEP.
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OBJECTIVE: To evaluate the relationship between p27Kip1 low expression in breast cancer and its prognostic implication in breast carcinoma patients. Methods All data that were associated with the study of the relationship between p27Kip1 and the prognosis for breast cancer was pooled from Cochrane library, PubMed, Embase and Medlinebase. The outcome was measured using the risk ratio (RR). Data pooling was performed by RevMan 4. 2. Results 6457 patients from 20 studies were included in this meta-analysis. RR estimate of overall survival (OS) for patients with low level p27Kip1 was 2.07 [1.66,2.60] (P<0.01). For disease free survival (DFS), the pooled RR was 1.27 [1.10,1.47] (P<0.05). The combined RR estimate of relapse free survival (RFS) for patients with low level of p27Kip1 was 1.49 [0.92, 2.42] (P >0.05). In patients with lymph node negative breast carcinoma, the combined RR for OS and RFS were 1.98 [1.34,2.91] (P <0.01) and 1.28 [0.45,3.65] (P > 0.05), respectively. Among the patients with lymph node positive breast carcinoma, the combined RR for OS and RFS was 1.92 [1.31, 2.82] (P=0.0009) and 1.35 [0.96,1.89] (P>0.05) respectively. Conclusions Low level of p27Kip1 appears to be an independent prognostic factor to OS and DFS of breast cancer patients but not to RFS. Additional studies with large patient number and widely accepted practical methods are required to derive the precise prognostic significance of p27Kip1 expression in breast cancer patients.
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Neoplasias da Mama/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Metástase Linfática/diagnóstico , Prognóstico , Biomarcadores Tumorais/análise , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma/diagnóstico , Carcinoma/genética , Carcinoma/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/genética , Intervalo Livre de Doença , Feminino , Humanos , Metástase Linfática/fisiopatologia , Estadiamento de Neoplasias/métodosRESUMO
We sought to investigate safety of axitinib or sorafenib in renal cell carcinoma (RCC) patients and compare toxicity of these two vascular endothelial growth factor receptor inhibitors. Databases of PubMed and Embase were searched. We included phase II and III prospective trials, as well as retrospective studies, in which patients diagnosed with RCC were treated with axitinib or sorafenib monotherapy at a starting dose of 5 mg and 400 mg twice daily, respectively. The overall incidence of high grade hypertension, fatigue, gastrointestinal toxicity and hand-foot syndrome, along with their 95% confidence intervals (CI), were calculated using fixed- or random- effects model according to heterogeneity test results. A total of 26 trials, including 4790 patients, were included in our meta-analysis. Among them, 6 arms were related to axitinib and 22 were associated with sorafenib. The incidences of hypertension (24.9% vs. 7.9%), fatigue (8.2% vs. 6.6%), and gastrointestinal toxicity (17.6% vs. 11.3%) were higher in patients receiving axitinib versus those receiving sorafenib, while the incidence of hand-foot syndrome was lower in patients receiving axitinib versus those receiving sorafenib (9.5% vs. 13.3%). In conclusion, axitinib showed noticeably higher risks of toxicity versus sorafenib. Close monitoring and effective measures for adverse events are recommended during therapy.
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Tiocianatos/urina , Adulto , Feminino , Indústria Alimentícia , Humanos , Masculino , Pessoa de Meia-Idade , Fumar/epidemiologia , Recursos HumanosRESUMO
Sample size re-estimation is essential in oncology studies. However, the use of blinded sample size reassessment for survival data has been rarely reported. Based on the density function of the exponential distribution, an expectation-maximization (EM) algorithm of the hazard ratio was derived, and several simulation studies were used to verify its applications. The method had obvious variation in the hazard ratio estimates and overestimation for the relatively small hazard ratios. Our studies showed that the stability of the EM estimation results directly correlated with the sample size, the convergence of the EM algorithm was impacted by the initial values, and a balanced design produced the best estimates. No reliable blinded sample size re-estimation inference can be made in our studies, but the results provide useful information to steer the practitioners in this field from repeating the same endeavor..
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OBJECTIVE: Recently, several cohort studies suggested a positive relationship between serum uric acid (SUA) and type 2 diabetes mellitus (T2DM), which is inconsistent with the results of functional research. Our aim was to further evaluate this correlation by conducting a systematic review. METHODS: Computerized literature searches of the Medline database, EMBASE database, and PubMed were used to evaluate the relationship between SUA and T2DM in cohort studies. Cochran's Q and I2 statistics were used to evaluate heterogeneity among studies, and pooled relative risk (RR) and odds ratio (OR) with 95% confidence intervals (CIs) were calculated using random-effects and fixed-effects models. The summary RR and OR of per 1 mg/ml-SUA increase were calculated separately because of their different epidemiological implications and calculation methods. Additionally, sensitivity analysis, stratified analysis, meta-regression, and multiple meta-regression were applied to investigate the heterogeneity among studies. RESULTS: A total of 970 articles were retrieved from the searches. Sixteen publications of cohort studies containing 61,714 participants were included. The pooled RR was 1.131 (95% CI: 1.084-1.179) with significant heterogeneity among studies (I2 = 51.9%, P = 0.018). Adjusted RR to evaluate the stability of the relationship between SUA and T2DM in the sensitivity analysis was similar (RR = 1.140, 95% CI: 1.087-1.197), with statistically significant heterogeneity (I2 = 54.5%, P = 0.015). Stratified analysis and meta-regression showed that the positive relationship remained irrespective of age, sex, region, and adjustment for confounding factors including body mass index, fasting blood glucose, systolic blood pressure, diastolic blood pressure, alcohol consumption, smoking, blood cholesterol, waist circumference, fatty liver, and drugs affecting SUA. CONCLUSION: Although SUA is independently associated with development of T2DM, insulin resistance increased as the baseline SUA concentration increased; thus, the correlation between SUA and T2DM requires further evaluation and the baseline insulin resistance status should also be considered.
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BACKGROUND: With development and application of new and effective anti-cancer drugs, the median survival post-progression (SPP) is often prolonged, and the role of the median SPP on surrogacy performance should be considered. To evaluate the impact of the median SPP on the correlation between progression-free survival (PFS) and overall survival (OS), we performed simulations for treatment of four types of cancer, advanced gastric cancer (AGC), metastatic colorectal cancer (MCC), glioblastoma (GBM), and advanced non-small-cell lung cancer (ANSCLC). MATERIALS AND METHODS: The effects of the median SPP on the statistical properties of OS and the correlation between PFS and OS were assessed. Further, comparisons were made between the surrogacy performance based on real data from meta-analyses and simulation results with similar scenarios. RESULTS: The probability of a significant gain in OS and HR for OS was decreased by an increase of the SPP/ OS ratio or by a decrease of observed treatment benefit for PFS. Similarly, for each of the four types of cancer, the correlation between PFS and OS was reduced as the median SPP increased from 2 to 12 months. Except for ANSCLC, for which the median SPP was equal to the true value, the simulated correlation between PFS and OS was consistent with the values derived from meta-analyses for the other three kinds of cancer. Further, for these three types of cancer, when the median SPP was controlled at a designated level (i.e., < 4 months for AGC, < 12 months for MCC, and <6 months for GBM), the correlation between PFS and OS was strong; and the power of OS reached 34.9% at the minimum. CONCLUSIONS: PFS is an acceptable surrogate endpoint for OS under the condition of controlling SPPs for AGC, MCC, and GBM at their limit levels; a similar conclusion cannot be made for ANSCLC.
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Carcinoma Pulmonar de Células não Pequenas/mortalidade , Neoplasias Colorretais/mortalidade , Glioblastoma/mortalidade , Neoplasias Pulmonares/mortalidade , Modelos Estatísticos , Neoplasias Gástricas/mortalidade , Biomarcadores , Carcinoma Pulmonar de Células não Pequenas/patologia , Ensaios Clínicos como Assunto , Neoplasias Colorretais/patologia , Progressão da Doença , Intervalo Livre de Doença , Glioblastoma/patologia , Humanos , Neoplasias Pulmonares/patologia , Estadiamento de Neoplasias , Neoplasias Gástricas/patologia , Taxa de SobrevidaRESUMO
Toll-like receptor (TLR) 7 and 8 mediate anti-virus immunity and are of particular relevance to asthma. However, very little information about genetic association on TLR7/8 and asthma are available. This study aimed to evaluate the effects of polymorphisms in TLR7 and 8 on asthma risk and asthma-related phenotypes in a Chinese Han population. We enrolled 462 unrelated adult asthmatic patients and 398 healthy volunteers. The genotypes of tagging single nucleotide polymorphisms (SNPs) in TLR7 and 8 genes were determined using multiplex SNaPshot SNP genotyping assay. We used case-control and case-only studies to assess any links with asthma and asthma-related phenotypes. There was no association between the variants in TLR7 and 8 and asthma susceptibility. However, our results revealed that the genetic variants in TLR7 and 8 were associated with asthma-related phenotypes, including eosinophil counts, serum immunoglobulin E levels, lung function, and asthma severity as well. Our study suggests that TLR7 and 8 polymorphisms may play a considerable role in the pathogenesis of asthma. It will help in better understanding the pathogenesis of asthma and development of more effective strategies for asthma prevention, prediction, and therapy.
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Asma/genética , Polimorfismo de Nucleotídeo Único , Receptor 7 Toll-Like/genética , Receptor 8 Toll-Like/genética , Adolescente , Adulto , Idoso , Asma/etiologia , Estudos de Casos e Controles , China/etnologia , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , FenótipoRESUMO
In the evaluation of vaccine seroresponse rates and adverse reaction rates, extreme test results often occur, with substantial adverse event rates of 0% and/or seroresponse rates of 100%, which has produced several data challenges. Few studies have used both the Bayesian and frequentist methods on the same sets of data that contain extreme test cases to evaluate vaccine safety and immunogenicity. In this study, Bayesian methods were introduced, and the comparison with frequentist methods was made based on practical cases from randomized controlled vaccine trials and a simulation experiment to examine the rationality of the Bayesian methods. The results demonstrated that the Bayesian non-informative method obtained lower limits (for extreme cases of 100%) and upper limits (for extreme cases of zero), which were similar to the limits that were identified with the frequentist method. The frequentist rate estimates and corresponding confidence intervals (CIs) for extreme cases of 0 or 100% always equaled and included 0 or 100%, respectively, whereas the Bayesian estimations varied depending on the sample size, with none equaling zero or 100%. The Bayesian method obtained more reasonable interval estimates of the rates with extreme data compared with the frequentist method, whereas the frequentist method objectively expressed the outcomes of clinical vaccine trials. The two types of statistical results are complementary, and it is proposed that the Bayesian and frequentist methods should be combined to more comprehensively evaluate clinical vaccine trials.
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Anticorpos/sangue , Bioestatística/métodos , Vacinas/efeitos adversos , Vacinas/imunologia , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do TratamentoRESUMO
BACKGROUND: The role of cell-cycle protein cyclin D1 in lung cancer remains controversial. To clarify its impact on survival in non-small-cell lung cancer (NSCLC), we performed a meta-analysis on the currently available medial literature to quantitatively assess its role on survival of NSCLC according to cyclin D1 status. METHOD: Published studies that investigated the association between cyclin D1 expression and NSCLC survival were identified. Meta-analysis was performed by using a DerSimonian-Laird model. Funnel plot was used to investigate publication bias and sources of heterogeneity were identified by using meta-regression analysis. RESULT: A total of 24 studies with 2731 patients were evaluable for this meta-analysis. No statistical significance was found that cyclin D1 expression was associated with poor prognosis in NSCLC (hazard ratio 1.08 [95% CI, 0.80-1.45]) without publication bias found. But there was significant heterogeneity present; meta-regression analysis was used to explore the sources of heterogeneity and revealed that the outcome of analysis was influenced by cutoff values and ethnicity. No difference between positive and negative studies on study quality assessment was present. CONCLUSION: The cyclin D1 expression is unlikely to be useful as a prognostic marker for NSCLC in clinical practice from current evidence. The conclusion should be confirmed by a large well-designed prospective study.
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Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Ciclina D/metabolismo , Neoplasias Pulmonares/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Ciclina D/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/mortalidade , Variações Dependentes do Observador , Prognóstico , Análise de SobrevidaRESUMO
To explore the gene-based principal component logistic regression model and its application in genome-wide association study. Using the simulated genome-wide single nucleotide polymorphism (SNPs) genotypes data, we proposed a practical statistical analysis strategy-'the principal component logistic regression model', based on the gene levels to assess the association between genetic variations and complex diseases. The simulation results showed that the P value of genes in related diseases was the smallest among the results from all the genes. The results of simulation indicated that not only it could reduce the degree of freedom through hypothesis testing but could also better understand the correlations between SNPs. The gene-based principal component logistic regression model seemed to have certain statistical power for testing the association between genetic genes and diseases in the genome-wide association studies.
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Estudo de Associação Genômica Ampla , Modelos Logísticos , Simulação por Computador , Humanos , Polimorfismo de Nucleotídeo Único , Análise de Componente PrincipalRESUMO
AIM: To evaluate the effect of preoperative biliary drainage (PBD) on obstructive jaundice resulting from malignant tumors. METHODS: According to the requirements of Cochrane systematic review, studies in the English language were retrieved from MEDLINE and Embase databases from 1995 to 2009 with the key word "preoperative biliary drainage". Two reviewers independently screened the eligible studies, evaluated their academic level and extracted the data from the eligible studies confirmed by cross-checking. Data about patients with and without PBD after resection of malignant tumors were processed for meta-analysis using the Stata 9.2 software, including postoperative mortality, incidence of postoperative pancreatic and bile leakage, abdominal abscess, delayed gastric emptying and incision infection. RESULTS: Fourteen retrospective cohort studies involving 1826 patients with malignant obstructive jaundice accorded with our inclusion criteria, and were included in meta-analysis. Their baseline characteristics were comparable in all the studies. No significant difference was found in combined risk ratio (RR) of postoperative mortality and incidence of pancreatic and bile leakage, abdominal abscess, delayed gastric emptying between patients with and without PBD. However, the combined RR for the incidence of postoperative incision infection was improved better in patients with PBD than in those without PBD (P < 0.05). CONCLUSION: PBD cannot significantly reduce the postoperative mortality and complications of malignant obstructive jaundice, and therefore should not be used as a preoperative routine procedure for malignant obstructive jaundice.
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Drenagem/métodos , Icterícia Obstrutiva/cirurgia , Complicações Pós-Operatórias/mortalidade , Cuidados Pré-Operatórios/métodos , Estudos de Coortes , Esvaziamento Gástrico , Humanos , MEDLINE , Estudos Retrospectivos , Resultado do TratamentoRESUMO
In lieu of large samples of cases and/or controls with hundreds of markers spreading throughout the human genome, researchers started to notice the dramatic increase of genome-wide association study (GWAS) for complex disorders, in the last 5 years. This paper highlights the statistical challenges in such huge-scale genetic studies, and introduces the analytical strategies and steps for handling GWAS data. Such issues as quality control of data, population stratification, methods available to data analysis and results presentation, replication, as well as the limitations of GWAS studies and the challenges presenting for statistics, are addressed.
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Interpretação Estatística de Dados , Estudo de Associação Genômica Ampla , Biometria , HumanosRESUMO
Published data regarding the association between 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphisms and prostate cancer risk have been conflicting. To derive a more precise estimation of the relationship, a meta-analysis was performed. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association between MTHFR C677T and A1298C polymorphisms and prostate cancer risk. Six studies including 3511 cases and 2762 controls described C677T genotypes, among which four articles totalling 838 cases and 1121 controls described A1298C genotypes, were involved in this meta-analysis. Overall meta-analysis indicated that the 677T allele was more likely to exert a protective effect on prostate cancer risk (OR=0.81, 95% CI: 0.68-0.98) with a recessive genetic model. No association was found for the 677CT genotype and the 677TT mutant homozygote with prostate cancer risk compared with 677CC, with OR=1.13 (95% CI: 0.88-1.45) and OR=0.85 (95% CI: 0.71-1.03), respectively. No evidence of an association of MTHFR A1298C polymorphism with prostate cancer was found. This meta-analysis supports that the C677T of the MTHFR gene is a low-penetrance susceptibility gene for prostate cancer, and might provide protective effects against prostate cancer risk.
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Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo Genético , Neoplasias da Próstata/genética , Estudos de Casos e Controles , Genótipo , Humanos , Masculino , População Branca/genéticaRESUMO
OBJECTIVE: The purpose of this study was to approach the relation of SNP43, SNP44 locus, main haplotypes and haplotype combinations with type 2 diabetes mellitus (T2DM). METHODS: According to the theory and principles of systematic review, data from case-control studies regarding the association between calpain-10 (CAPN10) gene and T2DM were derived through electronic search of PubMed and Chinese journals databases. To gain a more precise estimation of the relationship, a stratified Meta-analysis with four subgroups was performed according to the races. Publication bias was also assessed. RESULTS: The association with T2DM in different races was evaluated. In Mongoloid race, SNP43-G allele, G/G genotype and 111/221 haplotype combination showed notable association with T2DM with ORs (95%CI) as 1.368 (1.155 - 1.620), 1.437 (1.186 - 1.741) and 2.762 (1.287 - 5.927) respectively. In Caucasoid race, SNP44-C allele, 111/111 hapotype combination showed strong relationship with T2DM with ORs (95%CI) as 1.144 (1.023 - 1.278), 1.291(1.050 - 1.586) respectively. In Hybrid race, only one positive finding was obtained which was SNP44-C allele with OR (95%CI) as 1.653 (1.025 - 2.665). CONCLUSION: SNP43-G allele, G/G genotype, 111/221 were risk factors to Mongoloid race. And SNP-C allele, 111/111 haplotype combination were risk factors to Caucasoid race, and SNP44-C allele to Hybrid race.