170 research outputs found

    Simulation-based Estimation of Mean and Standard Deviation for Meta-analysis via Approximate Bayesian Computation (ABC)

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    Background: When conducting a meta-analysis of a continuous outcome, estimated means and standard deviations from the selected studies are required in order to obtain an overall estimate of the mean effect and its confidence interval. If these quantities are not directly reported in the publications, they need to must be estimated from other reported summary statistics, such as the median, the minimum, the maximum, and quartiles. Methods: We propose a simulation-based estimation approach using the Approximate Bayesian Computation (ABC) technique for estimating mean and standard deviation based on various sets of summary statistics found in published studies. We conduct a simulation study to compare the proposed ABC method with the existing methods of Hozo et al. (2005), Bland (2015), and Wan et al. (2014). Results: In the estimation of the standard deviation, our ABC method performs best in skewed or heavy-tailed distributions. The average relative error (ARE) approaches zero as sample size increases. In the normal distribution, our ABC performs well. However, the Wan et al. method is best since it is based on the normal distribution assumption. When the distribution is skewed or heavy-tailed, the ARE of Wan et al. moves away from zero even as sample size increases. In the estimation of the mean, our ABC method is best since the AREs converge to zero. Conclusion: ABC is a flexible method for estimating the study-specific mean and standard deviation for meta-analysis, especially with underlying skewed or heavy-tailed distributions. The ABC method can be applied using other reported summary statistics such as the posterior mean and 95% credible interval when Bayesian analysis has been employed

    ABCMETAapp: R Shiny Application for Simulation-based Estimation of Mean and Standard Deviation for Meta-analysis via Approximate Bayesian Computation (ABC)

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    Background and Objective: In meta-analysis based on continuous outcome, estimated means and corresponding standard deviations from the selected studies are key inputs to obtain a pooled estimate of the mean and its confidence interval. We often encounter the situation that these quantities are not directly reported in the literatures. Instead, other summary statistics are reported such as median, minimum, maximum, quartiles, and study sample size. Based on available summary statistics, we need to estimate estimates of mean and standard deviation for meta-analysis. Methods: We developed a R Shiny code based on approximate Bayesian computation (ABC), ABCMETA, to deal with this situation. Results: In this article, we present an interactive and user-friendly R Shiny application for implementing the proposed method (named ABCMETAapp). In ABCMETAapp, users can choose an underlying outcome distribution other than the normal distribution when the distribution of the outcome variable is skewed or heavy tailed. We show how to run ABCMETAapp with examples. Conclusions: ABCMETAapp provides a R Shiny implementation. This method is more flexible than the existing analytical methods since estimation can be based on five different distribution (Normal, Lognormal, Exponential, Weibull, and Beta) for the outcome variable

    Methylation mediated silencing of TMS1/ASC gene in prostate cancer

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    BACKGROUND: Transcriptional silencing associated with aberrant promoter methylation has been established as an alternate pathway for the development of cancer by inactivating tumor suppressor genes. TMS1 (Target of Methylation induced Silencing), also known as ASC (Apoptosis Speck like protein containing a CARD) is a tumor suppressor gene which encodes for a CARD (caspase recruitment domain) containing regulatory protein and has been shown to promote apoptosis directly and by activation of downstream caspases. This study describes the methylation induced silencing of TMS1/ASC gene in prostate cancer cell lines. We also examined the prevalence of TMS1/ASC gene methylation in prostate cancer tissue samples in an effort to correlate race and clinico-pathological features with TMS1/ASC gene methylation. RESULTS: Loss of TMS1/ASC gene expression associated with complete methylation of the promoter region was observed in LNCaP cells. Gene expression was restored by a demethylating agent, 5-aza-2'deoxycytidine, but not by a histone deacetylase inhibitor, Trichostatin A. Chromatin Immunoprecipitation (ChIP) assay showed enrichment of MBD3 (methyl binding domain protein 3) to a higher degree than commonly associated MBDs and MeCP2. We evaluated the methylation pattern in 66 prostate cancer and 34 benign prostatic hyperplasia tissue samples. TMS1/ASC gene methylation was more prevalent in prostate cancer cases than controls in White patients (OR 7.6, p 0.002) while no difference between the cases and controls was seen in Black patients (OR 1.1, p 0.91). CONCLUSION: Our study demonstrates that methylation-mediated silencing of TMS1/ASC is a frequent event in prostate cancer, thus identifying a new potential diagnostic and prognostic marker for the treatment of the disease. Racial differences in TMS1/ASC methylation patterns implicate the probable role of molecular markers in determining in susceptibility to prostate cancer in different ethnic groups

    Mucosal Melanomas of the Head and Neck: The Role of Postoperative Radiation Therapy

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    Objectives. Mucosal melanomas are rarer than their cutaneous counterparts and are associated with a poorer prognosis. We report the clinical outcomes of patients with mucosal melanomas of the head and neck region generally treated with definitive surgery followed by postoperative radiation therapy (RT). Methods. We reviewed the records of 17 patients treated at the University of Miami in 1990–2007. Patients generally received conventionally fractionated RT regimens to the postoperative bed. Elective nodal RT was not routinely delivered. Eight patients received adjuvant chemotherapy or immunotherapy. Results. Median followup was 35.2 months (range 5–225). As the first site of failure: 3 patients recurred locally, 2 regionally and 2 distantly. All 3 patients who recurred locally had not received RT. Of the 5 locoregional recurrences, 4 were salvaged successfully with multimodality therapy with no evidence of disease at last followup. Overall survival was 64.7% at 2 years and 51.5% at 5 years. Conclusions. Patients with mucosal melanoma of the head and neck are best treated with surgery to achieve negative margins, followed by postoperative RT to optimize local control. Elective nodal irradiation may not be indicated in all cases, as regional failures were not predominant. Distant metastases were fewer when compared to historical data, potentially due to advancements in adjuvant therapies as well as aggressive multi-modality salvage at time of failure

    Green salad intake is associated with improved oral cancer survival and lower soluble CD44 levels

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    Deficiencies in fruit and vegetable intake have been associated with oral cancer (oral cavity and oropharyngeal). Salivary rinses contain measurable biomarkers including soluble CD44 (solCD44) and total protein, which are known markers of oral cancer risk. This study investigates the effect of nutritional factors on solCD44 and protein levels to evaluate oral cancer risk and survival. We evaluated solCD44 and protein levels from 150 patients with oral and oropharyngeal squamous cell carcinoma and 150 frequency-matched controls. We subsequently characterized the effect of food group consumption and these biomarkers on progression-free survival (PFS) and overall survival (OS). Patients reported eating fewer servings of salad (p = 0.015), while controls reported eating fewer servings of potatoes (p \u3c 0.001). Oral cancer patients who consumed at least one serving per week of green salad were found to have significantly lower CD44 levels than those who ate salad less frequently (mean of log2[solCD44]1.73 versus 2.25, p = 0.014). Patients who consumed at least one serving per week of “salad or other vegetables” had significantly longer PFS (median 43.5 versus 9.1 months, p = 0.003, adjusted hazard ratio (HR) = 0.39 p = 0.014) and OS (median 83.6 versus 10 months, p = 0.008, adjusted HR = 0.04 p = 0.029). These findings suggest that dietary factors, namely greater green salad and vegetable intake, may be associated with lower CD44 levels and better prognosis in oral cancer patients

    Decreased Levels of Soluble CD44 in a High-Risk Population following a Smoking Cessation Program

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    Tobacco is a risk factor of head and neck cancer (HNC) and smoking cessation alone may reduce HNC risk by 70%. Soluble CD44 (solCD44), a cell surface receptor linked to cell proliferation and migration, and total protein (TP) levels can detect early HNC. This study aims to determine whether salivary solCD44 and TP levels in oral rinses change following a smoking cessation program. 150 smokers provided oral rinse samples at baseline and at a 12-month follow-up after participation in a smoking cessation program. Assays to measure levels of solCD44, TP, and cotinine, a metabolite used as a biomarker of tobacco exposure, were completed. A paired-samples t-test was used to determine whether there was a statistically significant ( \u3c 0.05) mean difference in biomarker levels before and after the program. Baseline and at 12-month follow-up data were available for 88 subjects, 21 of whom quit smoking entirely. Mean levels of solCD44 significantly decreased by 0.412 ng/mL from baseline to the 12-month follow-up, = 0.010. There was no significant difference in mean TP levels, = 0.975. Mean cotinine levels decreased significantly by 74.7 ng/mL, = 0.035. This is the first work demonstrating an association between smoking cessation and decreased solCD44 levels in oral rinses. Decreased expression of the tumorigenic CD44 may be one mechanism by which smoking cessation lowers cancer risk

    Decreased levels of soluble cd44 in a high-risk population following a smoking cessation program

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    Tobacco is a risk factor of head and neck cancer (HNC) and smoking cessation alone may reduce HNC risk by 70%. Soluble CD44 (solCD44), a cell surface receptor linked to cell proliferation and migration, and total protein (TP) levels can detect early HNC. This study aims to determine whether salivary solCD44 and TP levels in oral rinses change following a smoking cessation program. 150 smokers provided oral rinse samples at baseline and at a 12-month follow-up after participation in a smoking cessation program. Assays to measure levels of solCD44, TP, and cotinine, a metabolite used as a biomarker of tobacco exposure, were completed. A paired-samples t-test was used to determine whether there was a statistically significant (p \u3c 0.05) mean difference in biomarker levels before and after the program. Baseline and at 12-month follow-up data were available for 88 subjects, 21 of whom quit smoking entirely. Mean levels of solCD44 significantly decreased by 0.412 ng/mL from baseline to the 12-month follow-up, p = 0.010. There was no significant difference in mean TP levels, p = 0.975. Mean cotinine levels decreased significantly by 74.7 ng/mL, p = 0.035. This is the first work demonstrating an association between smoking cessation and decreased solCD44 levels in oral rinses. Decreased expression of the tumorigenic CD44 may be one mechanism by which smoking cessation lowers cancer risk

    The Reversal of Immune Exclusion Mediated by Tadalafil and an Anti-tumor Vaccine Also Induces PDL1 Upregulation in Recurrent Head and Neck Squamous Cell Carcinoma: Interim Analysis of a Phase I Clinical Trial

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    Myeloid Derived suppressor cells (MDSCs) play a key role in the progression and recurrence of human malignancies and in restraining the efficacy of adjuvant therapies. We have previously shown that Tadalafil lowers MDSCs and regulatory T cells (Treg) in the blood and in the tumor, primes a tumor specific immune response, and increases the number of activated intratumoral CD8+T cells in patients with primary Head and Neck Squamous Cell Carcinoma (HNSCC). However, despite these important immune modulatory actions, to date no clinically significant effects have been reported following PDE5 inhibition. Here we report for the first time interim results of our ongoing phase I clinical trial (NCT02544880) in patients with recurrent HNSCC to evaluate the safety of and immunological effects of combining Tadalafil with the antitumor vaccine composed of Mucin1 (MUC1) and polyICLC. The combined treatment of Tadalafil and MUC1/polyICLC vaccine was well-tolerated with no serious adverse events or treatment limiting toxicities. Immunologically, this trial also confirms the positive immunomodulation of Tadalafil in patients with recurrent HNSCC and suggests an adjuvant effect of the anti-tumor vaccine MUC1/polyICLC. Additionally, image cytometry analysis of scanned tumors indicates that the PDE5 inhibitor Tadalafil in conjunction with the MUC1/polyICLC vaccine effectively reduces the number of PDL1+macrophages present at the tumor edge, and increases the number of activated tumor infiltrating T cells, suggesting reversion of immune exclusion. However, this analysis shows also that CD163 negative cells within the tumor upregulate PDL1 after treatment, suggesting the instauration of additional mechanisms of immune evasion. In summary, our data confirm the safety and immunologic potential of PDE5 inhibition in HNSCC but also point to PDL1 as additional mechanism of tumor evasion. This supports the rationale for combining checkpoint and PDE5 inhibitors for the treatment of human malignancies

    An international analysis evaluating frontline bendamustine with rituximab in extranodal marginal zone lymphoma

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    : Extranodal marginal zone lymphoma (EMZL) is a heterogeneous non-Hodgkin lymphoma. No consensus exists regarding the standard-of-care in patients with advanced-stage disease. Current recommendations are largely adapted from follicular lymphoma, for which bendamustine with rituximab (BR) is an established approach. We analyzed the safety and efficacy of frontline BR in EMZL using a large international consortium. We included 237 patients with a median age of 63 years (range, 21-85). Most patients presented with Eastern Cooperative Oncology Group (ECOG) performance status 0 to 1 (n = 228; 96.2%), stage III/IV (n = 179; 75.5%), and intermediate (49.8%) or high (33.3%) Mucosa Associated Lymphoid Tissue International Prognosis Index (MALT-IPI). Patients received a median of 6 (range, 1-8) cycles of BR, and 20.3% (n = 48) received rituximab maintenance. Thirteen percent experienced infectious complications during BR therapy; herpes zoster (4%) was the most common. Overall response rate was 93.2% with 81% complete responses. Estimated 5-year progression-free survival (PFS) and overall survival (OS) were 80.5% (95% CI, 73.1% to 86%) and 89.6% (95% CI, 83.1% to 93.6%), respectively. MALT-IPI failed to predict outcomes. In the multivariable model, the presence of B symptoms was associated with shorter PFS. Rituximab maintenance was associated with longer PFS (hazard ratio = 0.16; 95% CI, 0.04-0.71; P = .016) but did not impact OS. BR is a highly effective upfront regimen in EMZL, providing durable remissions and overcoming known adverse prognosis factors. This regimen is associated with occurrence of herpes zoster; thus, prophylactic treatment may be considered

    Avaliação do impacto da suplementação alimentar a gestantes no cotrole do baixo peso ao nascer no município de São Paulo, SP (Brasil)

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    A partir de estudo realizado em oito grandes maternidades do Município de São Paulo, SP (Brasil) que atendem clientela predominantemente de baixo nível sócio-econômico, objetivou-se analisar o impacto da suplementação alimentar durante a assistência pré-natal sobre a incidência de recém-nascidos de baixo peso ao nascer (peso < 2.500 g). Foram envolvidos no estudo 1.060 recém-nascidos de mães que receberam suplementação e 664 recém-nascidos de mães que não a receberam. Ã incidência de baixo peso ao nascer foi de cerca de 11%, considerada elevada e semelhante em ambos os grupos de recém-nascidos. A análise multivariada, realizada para controlar eventuais diferenças entre os grupos, que não a condição de suplementação, descartou qualquer associação significativa entre suplementação e peso ao nascer e revelou, por outro lado, que tabagismo e morbidade na gestação e determinadas características antropométricas e reprodutivas da mãe, prévias à gestação, são importantes fatores de risco para o baixo peso ao nascer. A aparente explicação para a ausência de impacto da suplementação alimentar na população estudada parece residir não na quantidade insuficiente da suplementação alimentar oferecida (370 Kcal/dia), mas no predomínio de fatores não alimentares na determinação do baixo peso ao nascer. São formuladas recomendações quanto ao controle do baixo peso ao nascer no contexto estudado
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