Sex Recognition of Skulls in Chinese Uygur / 法医学杂志

Objective Logistic regression method was used to establish a multiple regression sex discriminant function to discriminate the complete skull model and the incomplete skull model without frontal bone, occipital bone and mandible of Uygur adults in Turpan, Xinjiang. Methods A total of 117 （60 male and 57 female） three-dimensional skull models were collected by CT. Sixteen cranial measurement indexes were measured and calculated by computer software. The multivariate regression sex discriminant function was established with Logistic regression method and retrospectively tested. Results Among the 16 measurement indexes, except for nose width （x7） and maximum frontal breadth （x13）, the remaining 14 indexes had statistical significance of differences between male and female （P<0.05）. For the discriminant function of complete skull established by eyebrow arch convexity （x4）, mastoid width （x6）, maximum cranial length （x12）, cranial base length （x15）, cranial circumference （x16）, the male and female discrimination accuracy was 90.0% and 94.7%, respectively. For the sex discriminant function of incomplete skull without frontal bone established by mandibular angle width （x10）, mandibular height （x11） and cranial circumference （x16）, the discrimination accuracy of male and female was 85.0% and 84.2%, respectively. For the sex discriminant function of incomplete skull without occipital bone established by the index of eyebrow arch convexity （x4）, the discrimination accuracy of male and female was 80.0% and 73.7%, respectively. For the sex discriminant function of incomplete skull without mandible established by frontal chord （x5） and occipital protrusion angle （x9）, the discrimination accuracy of male and female was 85.0% and 78.9%, respectively. Conclusion The computer software and system developed in our study can achieve sex discrimination of complete skulls and incomplete skulls without frontal bone, occipital bone or mandible.

Sensitivity of gastric cancer stem cells to 5-fluorouracil and biological mechanism underlying multidrug resistance / 中国组织工程研究

BACKGROUND:Fluorouracil is a basic chemotherapy drug for gastric cancer, and its drug resistance is commonly seen in clinic. Cancer stem cels have low sensitivity to chemotherapy drugs, which may be an important cause of tumor recurrence and progression folowing chemotherpay. OBJECTIVE: To explore the sensitivity of gastric cancer stem cels to 5-fluorouracil and related biology mechanism underlying multidrug resistance. METHODS: Stem cel marker CD44 and multidrug resistance protein thymidylate synthase in 69 cases of gastric cancer tissues were tested by immunohistochemical staining. The selection strategy was based on the clonal morphology, and gastric cancer stem cels were isolated from human gastric cancer cel line AGS to detect the expression of CD44 and thymidylate synthase and the self renewing ability. Inhibitory concentration 50 (IC50) of 5-fluorouracil in different AGS cel clone was detected using cel counting kit-8. RESULTS AND CONCLUSION:In 69 cases of gastric cancer tissues, the positive expression rates of thymidylate synthase and CD44 were 57% (39/69) and 61% (42/69), respectively, and there was a positive correlation between the expression of CD44 and thymidylate synthase (Kappa=0.41,χ2=11.59,P < 0.05). Cloning efficiency of the AGS cel line was 39% (29/69), wherein, vice cloning, secondary cloning, and ful clone proportions were 17% (5/29), 69% (20/29), 14% (4/29), respectively. After sub-cloning, the clone was digested using trysin folowed by low-density passage; vice clones were unable to passage, secondary clones could only passage a few, and ful clones could serialy passage. After treatment with different concentrations of 5-fluorouracil, the ful clone growth inhibition rate was significantly lower than that of secondary clones and AGS cels (P < 0.05). These findings show that gastric cancer stem cels are less sensitive to 5-fluorouracil, indicating the cels have a resistance to chemotherapy drugs, which may be one of the chemotherapy resistance mechanisms in the clinical treatment of gastric cancer.