【Abstract】 Objective To introduce the cl inical appl ication of heterogeneity (cattle) acellular dermal matrix(ADM)in the repair of mucosa defect otolaryngology. Methods From October 2006 to March 2007, 12 cases of mucosa defect was repaired with heterogeneity ADM after the surgery. There were 10 males and 2 females, aged 18-76 years. Defect was caused by deflection of nasal septum in 1 case, melanoma of front and midst basal is (capillary hemangioma) in 1 case, nasal vestibule angioma (T2N2M0)in 1 case, cancer of hypopharynx (T2N1M0) in 1 case, cancer of amygdale in 3 cases (2 of T2N0M0 and 1 of T3N1M0),cervical segments esophageal carcinoma in 1 case, and cancer of larynx in 4 cases (3 of T2N0M0 and 1 of T3N1M0). Results All these 12 cases were followed up for 6 months. The results of endoscope showed that heterogeneity ADM mingled with mucosa within 3 months after operation and the function was recovered. Pharynx fistula occurred in 1 case of hypopharynx cancer afterthe operation. After treatment of dressing change and antibiotics for 10 days, the wound healed, but after 2 months tumor recurred. All the patients were treated by radiation treatment. One case of amygdala cancer recurred and transferred to the neck after 2 months of radiation treatment. But 1 case of hypopharynx cancer died of massive haemorrhage after radiation treatment for 3 months. Conclusion Heterogeneity ADM can be easily obtained and it is a new method to repair mucosa defect. Theoperative procedure is easy to perform and worthwhile to be appl ied to cl inical operation.
Objective To summarize and review the heterogeneity of bone marrow derived stem cells (BMDSCs) and its formation mechanism and significance, and to analyze the possible roles and mechanisms in intestinal epithel ial reconstruction. Methods The related l iterature about BMDSCs heterogeneity and its role in intestinal epithel ial repair was reviewed and analyzed. Results The heterogeneity of BMDSCs provided better explanations for its multi-potency. The probable mechanisms of BMDSCs to repair intestinal epithel ium included direct implantation into intestinal epithel ium, fusion between BMDSCs and intestinal stem cells, and promotion of injury microcirculation reconstruction. Conclusion BMDSCs have a bright future in gastrointestinal injury caused by inflammatory bowl disease and regeneration.
Objective To investigate confidence interval estimation for the amount of heterogeneity in meta-analysis. Methods On the basis of BT’s method, the approximate Q-statistic distribution following linear transformation of Chi-square was applied to improve the accuracy of Q-statistic distribution, and to obtain the confidence interval for the amount of heterogeneity in meta-analysis. Results In case, the Q1 distribution obtained 95%CI 0.07 to 2.20, while the Q2 distribution obtained 95%CI 0.00 to 1.41; The proposed method Q2 narrowed down the range of confidence interval. Conclusion On account of improving the accuracy of Q-statistic distribution, the proposed method effectively strengthens the coverage probabilities of the confidence interval for the amount of heterogeneity. And the proposed method can also improve the precision of the confidence interval estimation for the amount of heterogeneity.
Through collecting and synthesizing the paper concerning the method of dealing with heterogeneity in the meta analysis, to introduce the multi-levels statistical models, such as meta regression and baseline risk effect model based on random effects, and random effects model based on hierarchical bayes, and to introduce their application of controlling the meta analysis heterogeneity. The multi-levels statistical model will decompose the single random error in the traditional model to data structure hierarchical. Its fitting effect can not only make the meta-analysis result more robust and reasonable, but also guide clinical issues through the interpretation of association variable.
Objective To analyze the heterogeneity of systematic reviews (SRs)/Meta-analysis on traditional Chinese medicine (TCM), and explore strategies for addressing heterogeneity correctly during the process of conducting TCM related to systematic reviews (SRs). Methods Both electronic and hand searches were used to identify TCM SRs in CBM, CNKI, VIP database, and Chinese Journal of Evidence-Based Medicine. Two researchers performed data extracting and heterogeneity evaluation independently. Results A total of 115 TCM SRs were included, involving 17 types of diseases, among which the cardiovascular and cerebrovascular diseases were the most addressed (n=36, 31.30%). There were 35.65% (n=41) of SRs which integrated two or more types of studies; interventions of the included studies were inconsistent in 53.91% (n=62) of TCM SRs; control groups of the included studies were completely different in 60 (52.17%) SRs; and 8.7% (n=10) of SRs failed to investigate heterogeneity in the process of synthesis analysis. Conclusion The heterogeneity is common in TCM related to SRs, and the most addressed is clinical heterogeneity. Addressing heterogeneity incorrectly would downgrade the quality of TCM related to SRs.
Objective To summarize the advancement of breast cancer stem cells and genotyping and analyze the correlation between the two. Methods Relevant literatures about breast cancer stem cells and genotyping, which were published recently were collected and reviewed. Results Cancer stem cell origin theory was supported by researches of correlation between breast cancer stem cells and genotyping, which also explained the complexity of intrinsic subtypes and heterogeneity of breast cancer. Conclusions A new way can be detected to study the formation mechanism and biological characteristics of breast cancer at the cellular and molecular level by researches of correlation between breast cancer stem cells and genotyping, which are expected to provide new strategies and tools for diagnosis and treatment of breast cancer.
Objective To summarize the research progress of distributional heterogeneity of the molecular pathology characteristics in breast cancer. Methods The related literatures about the distribution of the molecular pathology characteristics in breast cancer were reviewed. Results The breast cancer had the same heterogeneity as other cancers. At the same time, the molecular pathology characteristics, such as estrogen receptor (ER), progesterone receptor (PR), Ki-67, and human epidermal growth factor receptor-2 (HER-2), had the distributional heterogeneity. The distributional heterogeneity of molecular pathology characteristics in breast cancer could effect the pathologic diagnosis, the treatment, and the prognosis. Conclusion Although there are some new techniques which were used to investigate the heterogeneity of breast cancer, but each way has some problems. The more attention should be paid to the research about the distributional heterogeneity of the molecular pathology characteristics in breast cancer.
Many meta-analysis studies evaluate rates as parameter to assess the overall estimate of effects. However, none of these studies address systematic approaches for the meta-analysis of rates. This paper outlines the conditions, analysis and software operation procedures for the meta-analysis of rates. It also compares different operation procedures of three types of commonly-used R software (Comprehensive Meta-Analysis, Stata and MetaAnalyst) through real application examples. The biggest challenge for the meta-analysis of rates is to determine whether rates can be pooled, and how to evaluate heterogeneity between studies' outcomes needs further discussion.
Compared with traditional head to head meta-analysis, network meta-analysis has more confounding factors and difficulties to handle. Due to the mutual transitivity of evidence in network meta-analysis, heterogeneity may be brought into indirect meta-analysis. Hence, effective differentiation and correct handling of heterogeneity are being current focus. In order to ensure the reliability of the results of network meta-analysis, the concept of homogeneity is proposed and a series of methods are developed for differentiation and handling of homogeneity. Based on the extension of Bucher methods, current methods for differentiation and handling of homogeneity has extended to ten quantitative measures (eg., node analysis method, hypothesis tests, and two-step method). However, because of the differences and the focus of fundamental methodological theories as well as the limitation of statistics power, no highly-effective method has been worked out. Therefore, the exploration of highly-effective, simple and high-resolved methods are still needed.
ObjectiveStudy how to quantify the bias of each study and how to estimate them. MethodIn the random-effect model, it is commonly assumed that the effect size of each study in meta-analysis follows a skew normal distribution which has different shape parameter. Through introducing a shape parameter to quantify the bias and making use of Markov estimation as well as maximum likelihood estimation to estimate the overall effect size, bias of each study, heterogeneity variance. ResultIn simulation study, the result was closer to the real value when the effect size followed a skew normal distribution with different shape parameter and the impact of heterogeneity of random effects meta-analysis model based on the skew normal distribution with different shape parameter was smaller than it in a random effects metaanalysis model. Moreover, in this specific example, the length of the 95%CI of the overall effect size was shorter compared with the model based on the normal distribution. ConclusionIncorporate the bias of each study into the random effects meta-analysis model and by quantifying the bias of each study we can eliminate the influence of heterogeneity caused by bias on the pooled estimate, which further make the pooled estimate closer to its true value.