Withdrawing medical treatment is quite common among patients with malignant tumors in present clinical practice in China,which is considered as a form of passive euthanasia and serious violation against social ethics and medical purposes.In this paper,the behaviors and reasons for withdrawing treatment of patients with malignant tumors are analyzed,and concerned solutions are explored as well.

Objective To investigate the sensitivity of tumor cells to photodynamic therapy(PDT), and to select the optimal photo-dose and photo density for PDT to the cultured cells. Methods Cells of SHEE and SHEEC cell lines were divided into 21 groups randomly,after 24 h inoculation, the cells accreted on paries of culture capsule completely, we replaced M199 complete culture solution with 30 μg/rnl Photofrin-Ⅱ solution 100 μl and then replacd with M199 complete culture solution without Photofiin-Ⅱ after 150 min of incubation in Photofrin-Ⅱ. Within 15 min,we dealed the cells with PDT using Photofrin-Diomed 630 under three different power densities:25 raW/cm~2,50 mW/cm~2 and 100 mW/cm~2 for 10 s,20 9,30 s,50 s, 100 s, 150 s and 200 s respectively,and then continue for 24 h culture. We examined the inhibiting effect on cell line SHEE and SHEEC under PDT by the method of CCK-8. Results There was no significant difference in the inhibition ratio with same power density of PDT between cell line SHEE and SHEEC under the concentration of 30 μg/ml Photofrin-Ⅱ. However, the inhibition ratio increased with the raising of photo-dose of PDT,but there was a platform stage after the 2.5～30 J/cm~ 2 photo-dose. Conclu-sion The difference for photodynamic sensitivity between human immortalization esophageal epithelial cell line SHEE and the malignant transformation cell line SHEEC is not significant. The targeting of PDT to malignant tumor cell may not be involved in the photosensitivity for tumor cell.

Objective:To investigate expressions and clinical significance of plasma exosomal hsa_circ_0022417 in gastric cancer (GC).Methods:Sixty gastric cancer patients, 30 chronic gastritis patients (disease control group) and 30 healthy volunteers (healthy control group) were enrolled in this study. The expression levels of plasma exosomal hsa_circ_0022417 and serum CEA and CA19-9 were detected. The ROC curve and AUC were used to estimate the diagnostic capacity.Results:Compared with chronic gastritis patients and healthy control, the expression of plasma exosomal hsa_circ_0022417 was significantly upregulated in the gastric cancer group ( F=9.96, P<0.05). The expression level of hsa_circ_0022417 in GC tissue was significantly higher than that in adjacent tissue ( t=6.08, P<0.05). The AUC of hsa_circ_0022417, serum CEA and CA 19-9 was 0.79, 0.68 and 0.66, respectively. The combined detection of three indicators had the highest AUC (0.86) ( P<0.05). The expression level of exosomal hsa_circ_0022417 was significantly correlated with tumor size ( χ2=6.42, P<0.01), differentiation degree ( χ2=5.83, P=0.05), TNM stage ( χ2=7.14, P<0.05) and lymph node metastasis ( χ2=5.17, P<0.05). Conclusion:Exosome hsa_circ_0022417 is highly expressed in the plasma of GC patients, which is of great significance for clinical auxiliary diagnosis and early screening of GC.

Objective:This study aimed to investigate the expression of plasma exosomal hsa_circ_0064910 in gastric cancer (GC) patients, explore its correlation with the clinical pathological characteristics and evaluate its diagnostic efficacy in GC.Methods:Sixty patients with GC and 30 patients with Chronic Gastritis (disease control group) admitted to The First Affiliated Hospital of Henan University from October 2019 to December 2020 were selected. Meanwhile, 30 healthy subjects (healthy control group) who underwent physical examination were also enrolled. General data of GC patients were collected, including tumor size, degree of differentiation, TNM stage, lymph node metastasis, etc. Blood samples were collected before treatment and the expression levels of plasma exosomal hsa_circ_0064910 were detected via quantitative reverse transcription PCR (qRT-PCR). The serum concentrations of traditional biomarker (CEA and CA19-9) were measured via a chemiluminescent detection system. The receiver operating characteristic (ROC) curve and area under curve (AUC) were used to estimate the diagnostic capacity of different index in GC. Then, the expression difference of plasma exosomal hsa_circ_0064910 in GC patients before and after operation was analyzed, and its relationship with clinicopathological features of GC patients was also investigated.Results:RT-PCR results revealed that compared with Chronic gastritis patients and healthy control, the expression of plasma exosomal hsa_circ_0064910 was upregulated in the gastric cancer group(0.47±0.06, 0.43±0.05, 0.97±0.12, all P<0.001). The area under the ROC curve was 0.778, and AUC of the combination of CEA and CA19-9 for the diagnosis of gastric cancer was 0.841. which was higher than the diagnostic accuracies of CEA (AUC=0.673)and CA 19-9(AUC=0.653). The expression level of exosomal hsa_circ_0064910 was also significantly correlated with tumor size( χ2=7.545, P<0.01), TNM stage( χ2=4.571, P<0.05)and lymph node metastasis( χ2=6.907, P<0.01). The postoperative expression levels of exosomal hsa_circ_0064910 were lower compared with those of preoperative levels(1.21±0.21 vs 0.62±0.11, P<0.01). Conclusion:Our data demonstrated that exosomal hsa_circ_0064910 is highly expressed in GC patients and might be a potential noninvasive biomarker for the auxiliary diagnosis of GC.