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Objective To observe the value of clinical and CT radiomics features for predicting microsatellite instability-high(MSI-H)status of gastric cancer.Methods Totally 150 gastric cancer patients including 30 cases of MSI-H positive and 120 cases of MSI-H negative were enrolled and divided into training set(n=105)or validation set(n=45)at the ratio of 7∶3.Based on abdominal vein phase enhanced CT images,lesions radiomics features were extracted and screened,and radiomics scores(Radscore)was calculated.Clinical data and Radscores were compared between MSI-H positive and negative patients in training set and validation set.Based on clinical factors and Radscores being significant different between MSI-H positive and negative ones,clinical model,CT radiomics model and clinical-CT radiomics combination model were constructed,and their predictive value for MSI-H status of gastric cancer were observed.Results Significant differences of tumor location and Radscore were found between MSI-H positive and negative patients in both training and validation sets(all P＜0.05).The area under the curve(AUC)of clinical model,CT radiomics model and combination model for evaluating MSI-H status of gastric cancer in training set was 0.760,0.799 and 0.864,respectively,of that in validation set was 0.735,0.812 and 0.849,respectively.AUC of clinical-CT radiomics combination model was greater than that of the other 2 single models(all P＜0.05).Conclusion Clinical-CT radiomics combination model based on tumor location and Radscore could effectively predict MSI-H status of gastric cancer.
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Objective To explore the proliferation-promoting effect of bovine mammary gland epithelial cells (BMECs) co-cultured with umbilical cord mesenchymal stem cells (UC-MSCs) in serum-free culture mediuum.Methods Bovine UC-MSCs and BMECs were selected for co-culturing in direct or indirect contact.In the direct contact culture groups, UC-MSCs and BMECs were co-cultured at concentration ratios of 2∶1, 1∶1, 1∶2, 1∶3, 1∶4, 1∶5, and 1:10, respectively.In the indirect contact culture group, the supernatant of UC-MSCs was used as the conditioned medium to re-suspend BMECs.In the control groups, UC-MSCs and BMECs were cultured alone.The cell growth status in each group was observed at 0, 4, 8, 12, 24, 36, 48, 60, 72 h after culture, and cell proliferation was detected by cell counting kit-8 (CCK-8) assay.Results At 48 h, the optical density of the conditioned medium-BMECs group was significantly higher compared with the control groups (P<0.05).Meanwhile, the optical density in the direct contact group at a concentration ratio of 1∶2 reached the peak, which was extremely significantly higher compared with the control groups (P<0.01) and significantly higher compared with the other direct contact culture groups and the conditioned medium-BMECs group (P<0.05).Conclusions Co-culture of UC-MSCs and BMECs in serum-free culture medium is capable to promote the proliferation of BMECs, and the co-culture by cell-to-cell contact has a better effect.The optimal concentration ratio of UC-MSCs to BMECs is 1∶2, and the optimal culture time is 48 h.