ABSTRACT
Missing data is a common but unavoidable issue in clinical trials. It not only lowers the trial power, but brings the bias to the trial results. Therefore, on one hand, the missing data handling methods are employed in data analysis. On the other hand, it is vital to prevent the missing data in the trials. Prevention of missing data should take the first place. From the perspective of data, firstly, some measures should be taken at the stages of protocol design, data collection and data check to enhance the patients' compliance and reduce the unnecessary missing data. Secondly, the causes of confirmed missing data in the trials should be notified and recorded in detail, which are very important to determine the mechanism of missing data and choose the suitable missing data handling methods, e.g., last observation carried forward (LOCF); multiple imputation (MI); mixed-effect model repeated measure (MMRM), etc.
Subject(s)
Humans , Clinical Trials as Topic , Data Collection , Methods , Reference Standards , Models, Theoretical , Research DesignABSTRACT
Testing of hypothesis was affected by statistical analysis set division which was an important data management work before data base lock-in. Objective division of statistical analysis set under blinding was the guarantee of scientific trial conclusion. All the subjects having accepted at least once trial treatment after randomization should be concluded in safety set. Full analysis set should be close to the intention-to-treat as far as possible. Per protocol set division was the most difficult to control in blinded examination because of more subjectivity than the other two. The objectivity of statistical analysis set division must be guaranteed by the accurate raw data, the comprehensive data check and the scientific discussion, all of which were the strict requirement of data management. Proper division of statistical analysis set objectively and scientifically is an important approach to improve the data management quality.
Subject(s)
Clinical Trials as Topic , Reference Standards , Databases, Factual , Research Design , Reference Standards , Statistics as TopicABSTRACT
CAL-101 is a selective inhibitor of the phosphatidylinositol-3 kinase (PI3K), it inhibits the survival, proliferation and migration of tumor cells by directly inducing apoptosis and inhibiting micro-environmental interactions. It has been determined that the P110δ isoforms of PI3K expressed primarily in cells of hematopoietic lineage, such as B and T cells. This review focuses on the target, mechanism of action, the use and prospect of CAL-101 in tumors of blood and lymph systems.
Subject(s)
Animals , Humans , Class Ia Phosphatidylinositol 3-Kinase , Hematologic Neoplasms , Drug Therapy , Purines , Pharmacology , Therapeutic Uses , Quinazolinones , Pharmacology , Therapeutic Uses , Signal TransductionABSTRACT
Therapy-related myelodysplasia syndromes/acute myeloid leukemia (t-MDS/AML) is a clinical syndrome occurring as a late complication after chemotherapy and (or) radiotherapy, attracting much more attention owing to the improved treatment agents and longer survival of many treated patients. According to the WHO classification of 2008, t-MDS/AML is a serious complication of chemotherapy or radiotherapy given to a malignant or nonmalignant condition consisting of t-AML, t-MDS and t-MDS/myeloproliferative diseases (t-MDS/MPD). This review mainly focuses on the pathogenesis, relationship with primary tumour, treatment and prognosis of t-MDS/AML.
Subject(s)
Humans , Leukemia, Myeloid, Acute , Therapeutics , Myelodysplastic Syndromes , Therapeutics , Myeloproliferative Disorders , Neoplasms, Second Primary , PrognosisABSTRACT
Numerous interpolation-based methods have been described for reducing metal artifacts in CT images, but due to the limit of the interpolation methods, interpolation alone often fails to meet the clinical demands. In this paper, we describe the use of quartic polynomial interpolation in reconstruction of the images of the metal implant followed by linear interpolation to eliminate the streaks. The two interpolation methods are combined according to their given weights to achieve good results.
Subject(s)
Humans , Algorithms , Artifacts , Dental Prosthesis , Radiographic Image Interpretation, Computer-Assisted , Methods , Tomography, X-Ray Computed , MethodsABSTRACT
<p><b>OBJECTIVE</b>To explore several numerical methods of ordinal variable in one-way ordinal contingency table and their interrelationship, and to compare corresponding statistical analysis methods such as Ridit analysis and rank sum test.</p><p><b>METHODS</b>Formula deduction was based on five simplified grading approaches including rank_r(i), ridit_r(i), ridit_r(ci), ridit_r(mi), and table scores. Practical data set was verified by SAS8.2 in clinical practice (to test the effect of Shiwei solution in treatment for chronic tracheitis).</p><p><b>RESULTS</b>Because of the linear relationship of rank_r(i) = N ridit_r(i) + 1/2 = N ridit_r(ci) = (N + 1) ridit_r(mi), the exact chi2 values in Ridit analysis based on ridit_r(i), ridit_r(ci), and ridit_r(mi), were completely the same, and they were equivalent to the Kruskal-Wallis H test. Traditional Ridit analysis was based on ridit_r(i), and its corresponding chi2 value calculated with an approximate variance (1/12) was conservative. The exact chi2 test of Ridit analysis should be used when comparing multiple groups in the clinical researches because of its special merits such as distribution of mean ridit value on (0,1) and clear graph expression. The exact chi2 test of Ridit analysis can be output directly by proc freq of SAS8.2 with ridit and modridit option (SCORES =).</p><p><b>CONCLUSION</b>The exact chi2 test of Ridit analysis is equivalent to the Kruskal-Wallis H test, and should be used when comparing multiple groups in the clinical researches.</p>
Subject(s)
Biomedical Research , Methods , Statistics as Topic , Statistics, NonparametricABSTRACT
Objective To study the effect of different concentration of 1,25-dihydroxyvitamin D3[1,25(OH)2D3] on cell proliferation,differentiation and the expression of vitamin D receptor (VDR) in mouse MC3T3E1 osteoblast.Methods Osteoblast were cultured in medium with different concentrations of 1,25(OH)2D3.Incubated for 48 h,cell proliferation of osteoblast were examined by MTT reduction assay (mono-nuclear cell direc cytotoxicity assay),the osteocalcin (OC) levels in cell medium were detected by ELISA,and the expression of VDR mRNA and protein were examined by using SYBR Green real-time PCR and Western blot,respectively.Results 1.After incubation with 1,25(OH)2D3 for 48 h,the number of MC3T3E1 osteoblast was significantly less than that in control group(P0.05).3.SYBR Green real-time PCR and Western blot results showed that the expression of VDR mRNA as well as VDR protein of osteoblast in 10-8,10-9 mol/L experimental groups were significantly higher than those in control group (Pa0.05).Conclusions Cell proliferation of mouse osteoblast can be inhibited,while the cell differentiation was promoted by 1,25(OH)2D3.1,25(OH)2D3 up-regulated the expression of VDR in mouse osteoblast,which suggested that the VDR signal pathway may play some role in proliferation and differentiation of osteoblast.