Establishment of Internal Quality Control Method for Mixed and Split Samples by NAT in Blood Donor Screening / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To establish and evaluate the methods of internal quality control in blood donor screening by nucleic acid test (NAT).</p><p><b>METHODS</b>After HBV-DNA standard quality control (QC) sample (60 IU/ml) was diluted by pooling 6 samples, the concentration was 10.0 IU/ml, which was approach twice of the low limit. When the pooling result turned out reactive, the pooling samples need to be split into single sample to process. Meanwhile, the standard QC samples were tested as well. The same batch QC samples were tested 20 times respectively, calculate the mean (x̄), standard deviation (SD) and CV. Make Levey-Jennings QC curves by setting x̄±2SD as warning, x̄±3SD as rejected. The Levey-Jennings quality controls chart was mapped by using Microsoft Excel.</p><p><b>RESULTS</b>After 20 times test of mixed/split samples, the x̄±2SD were 33.03±1.47 and 30.08±0.98, the x̄±3SD were 33.03±2.20 and 30.08±1.47, the CV were 2.22% and 1.63%, respectively. The P value of t test was 0.08 and 0.17 respectively, there was no statistically significant difference between the 2 group.</p><p><b>CONCLUSION</b>When establish an internal QC system in the screening laboratory by nucleic acid testing, the concentration of the QC samples should be equal to normal specimens. This type of QC system may validate the extraction and amplification of the nucleic acid, and improve the stability of the test results.</p>

Differentiation Study of Chinese Medical Syndrome Typing for Diarrhea-predominant Irritable Bowel Syndrome Based on Information of Four Chinese Medical Diagnostic Methods and Brain-gut Peptides / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To establish discriminant functions of diarrhea-predominant irritable bowel syndrome (IBS-D) by studying it from quantitative diagnosis angle, hoping to reduce interference of subjective factors in diagnosing and differentially diagnosing Chinese medical syndromes of IBS-D.</p><p><b>METHODS</b>A Chinese medical clinical epidemiological survey was carried out in 439 IBS-D patients using Clinical Information Collection Table of IBS. Initial syndromes were obtained by cluster analysis. They were analyzed using step-by-step discrimination by taking information of four Chinese medical diagnostic methods and serum brain-gut peptides (BGP) as variables.</p><p><b>RESULTS</b>Clustering results were Gan stagnation Pi deficiency syndrome (GSPDS), Pi-Wei weakness syndrome (PWWS), Gan stagnation qi stasis syndrome (GSQSS), Pi-Shen yang deficiency syndrome (PSYDS), Pi-Wei damp-heat syndrome (PWDHS), cold-damp disturbing Pi syndrome (CDDPS). Of them, GSPDS was mostly often seen with effective percentage of 34. 2%, while CDDPS was the least often seen with effective percentage of 5.5%. A total of 5 discriminant functions for GSPDS, PWWS, GSQSS, PSYDS, and PWDHS were obtained by step-by-step dis- crimination method. The retrospective misjudgment rate was 4.1% (16/390), while the cross-validation misjudgment rate was 15.4% (60/390).</p><p><b>CONCLUSION</b>The establishment of discriminant functions is of value in objectively diagnosing and differentially diagnosing Chinese medical syndromes of IBS-D.</p>