Objective To investigate the application value of serum tumor necrosis factor alpha (TNF-α) expression in diagnosing colorectal cancer (CRC).Methods One hundred and thirty inpatients with CRC in our hospital from February 2015 to November 2016 were selected and divided into 90 cases of CRC confirmed by operation and histopathology(CRC group),including intestinal cancer with and without metastasis,and 40 cases of benign colorectal diseases(colonrectal benign disease group),at the same time 40 persons undergoing physical examination were selected as the healthy control group.The levels of TNF-α,carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 724 were collected in all subjects.The data of various groups were not normally distributed,and the nonparametric statistical method was used to analyze and compare.Results Serum TNF-α level in clinical TNM stage Ⅱ(median 9.47 pg/mL),Ⅲ(9.95 pg/mL) and Ⅳ(9.67 pg/mL) of the CRC group was significantly higher than that in TNM stage Ⅰ(6.59 pg/mL);which in the CRC with metastasis group (9.95 pg/mL) was higher than 8.03 pg/mL in CRC without metastasis group,the difference was statistically significant (P<0.05);the TNF-α expression had no obvious difference among different ages and between different genders(P>0.05).The area under the ROC curve in each test index:TNF-α was 0.868,CEA was 0.912,CA724 was 0.523,and which of their joint detection was 0.940.Conclusion The expression of TNF-α is increased in the occurrence and development process of CRC,its serum level detection has certain clinical application value,the TNF-α expression has no obvious difference in the subjects with different ages and different sexes and has wide suitability.The combine detection of serum TNF-α,CEA and CA724 in the patients with CRC significantly increases the level,the combined detection of 3-index can have complementary advantages to increase the sensitivity of CRC diagnosis,which serve as the significant indexes in CRC early diagnosis,therapeutic effect evaluation and prognosis monitoring.

Objective To study DNA quantification and STR typing of samples pre-treated with pyrami-don. Methods The blood samples of ten unrelated individuals were anticoagulated in EDTA. The blood stains were made on the filter paper. The experimental groups were divided into six groups in accor-dance with the storage time, 30 min, 1 h, 3 h, 6 h, 12 h and 24 h after pre-treated with pyramidon. DNA was extracted by three methods: magnetic bead-based extraction, QIAcube DNA purification method and Chelex-100 method. The quantification of DNA was made by fluorescent quantitative PCR. STR typing was detected by PCR-STR fluorescent technology. Results In the same DNA extraction method, the sample DNA decreased gradually with times after pre-treatment with pyramidon. In the same storage time, the DNA quantification in different extraction methods had significant differences. Sixteen loci DNA typing were detected in 90.56% of samples. Conclusion Pyramidon pre-treatment could cause DNA degradation, but effective STR typing can be achieved within 24 h. The magnetic bead-based extrac-tion is the best method for STR profiling and DNA extraction.