Objective To determine the effects of hypoxia pre-treatment combined with radiation damage on the hematopoietic cells in the bone marrow of mice.Methods A total of 165 male C57BL/6 mice(10～12 weeks old,weighing 20～25 g)were randomly divided into 7 groups:normal control(Control,n=33),6 Gy irradiation(6-Gy,n=43),7 d hypoxia-6 Gy irradiation(Hy-7 d+6 Gy,n=43),7 Gy irradiation(7 Gy,n=12),7 d hypoxia-7 Gy irradiation(Hy-7 d+7 Gy,n=12),7 Gy continuous hypoxia treatment(Hy-7 d+7 Gy+Hy,n=12),and 6 Gy continuous hypoxia treatment(Hy-7 d+6 Gy+Hy,n=10).The mice of the hypoxia treatment groups were given 7-day hypoxic pretreatment(12%oxygen)in a normobaric hypoxic chamber,while those of the other groups were housed in normoxic condition.After pretreatment,the mice of the irradiation groups were exposed to a single 6 or 7 Gy of whole-body 60Co γ-irradiation in normoxia.The mice of the hypoxia and irradiation groups were kept in hypoxic condition in 24 h post-irradiation followed by being resumed to normoxia,while those of the continuous hypoxia treatment groups were remained in hypoxia.After bone marrow cell suspensions were prepared from the Control,6 Gy,and Hy-7 d+6 Gy groups,bone marrow nucleated cells(BMNCs)were counted via automated cell counter.HE staining was employed to observe pathologic changes in medullary cavity,and flow cytometry was used to assess Lin-Sca1?c-Kit?(LSK)hematopoietic stem/progenitor cells,myeloid progenitors(MPs),and mature T/B/myeloid cells.The mice of the 7 Gy,Hy-7 d+7 Gy,and Hy-7 d+7 Gy+Hy groups were monitored for 30-day survival after hypoxic pretreatment.The dynamic changes in the counts of red blood cells(RBC),white blood cells(WBC)and platelets(PLT),and hemoglobin(HGB)level were observed in the 6 Gy,Hy-7 d+6 Gy,and Hy-7 d+6 Gy+Hy groups with aid of a fully automatic blood analyzer.Single-cell RNA sequencing was performed on bone marrow cell suspension derived from the mice euthanized in 17 d after irradiation from the Control,6 Gy,and Hy-7 d+6 Gy groups.Results ①Compared to the Control group,the 6 Gy group showed significantly reduced BMNCs(P<0.01),dilated bone marrow sinusoids,and erythrocyte extravasation.The Hy-7 d+6 Gy group exhibited higher cellular density and attenuated BMNC loss than the 6 Gy group(P<0.01).②Flow cytometry revealed less LSK,MP,and mature T/B/myeloid cells in the 6 Gy group than the Control group(P<0.05),and the reduced counts of LSK and MP were mitigated in the Hy-7 d+6 Gy group(P<0.01).③The Hy-7 d+7 Gy group demonstrated improved 30-day survival than the 7 Gy group(P<0.01),while continuous hypoxia(Hy-7 d+7 Gy+Hy)failed to enhance the survival.No statistical difference was seen in the survival rate between the 2 groups(P=0.12),though the Hy-7 d+7 Gy group showing higher survival rate.④Routine blood test revealed that the Hy-7 d+6 Gy group showed faster WBC recovery(vs the 6 Gy and Hy-7 d+6 Gy+Hy groups,P<0.05),higher pre-irradiation RBC/HGB levels,and accelerated PLT restoration(P<0.05).⑤Single-cell RNA sequencing indicated that hypoxia pretreatment suppressed the numbers of long-term hematopoietic stem cells/short-term hematopoietic stem cells(LT-HSC/ST-HSC)depletion in the Hy-7 d+6 Gy group when compared with the 6 Gy group,which was consistent with the results of flow cytometry.Pseudotime trajectory aligned the Hy-7 d+6 Gy group,as the Control group,showed enriched undifferentiated LSKs.Differential gene analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis revealed that oxidative phosphorylation pathway was strongly activated in the 6 Gy group,while the Hy-7 d+6 Gy group had enriched in chromatin remodeling and mRNA surveillance pathways.Conclusion Hypoxic preconditioning alleviates radiation-induced bone marrow injury,and post-irradiation normoxia restoration promotes hematopoietic recovery in acute radiation-exposed mice.

Objective To study the dosimetric peculiarity of 3D intracavitary brachytherapy in the application of endometrial carcinoma comparing with traditional 2D plans. Method 39 3D brachytherapy treatment plans of 11 patients with endometrial carcinoma were retrospectively analyzed with re?planning 2D treatment plan, the dose volume histogram ( DVH) parameters such as the target dose volume parameters V150 and D90 , the 2?cc doses to organs such as bladder, small intestine, rectum and sigmoid and the total reference air kerma TRAK were analyzed. The differences between the two groups are compared by paired samples T test. Results For target with V<60 cm3 ,there is no statistically significant difference between 2D and 3D plans,the D90 is (551?17±90?33) cGy and (574?15±117?18) cGy,respectively (P=0?390). As the increase of target volume,the D90 came to be significantly different ( P=0?001) , high dose region V150 for 3D and 2D plans is (51?05±21?61) cm3 and (53?41±11?71) cm3, respectively (P=0?482). With the target volume larger than 60 cm3 ,compare to 2D plans, the 3D plan can increase the target coverage as well as OAR dose except for small intestine ( P=0?128) . In addition, with different plan mode,the BMI did not affect the crisis organ dose such as rectum, small intestine, bladder and sigmoid, the P value is 0?239, 0?198,0?744 and 0?834,respectively. Conclusions For endometrial carcinoma,compared with traditional two?dimensional plans,the 3D brachytherapy treatment plans can significantly improve the target coverage and avoiding overdose of organs, clinical curative effect and side effect still needs further observation.

Objective: To explore the effect of calcium channel blocker (CCB) treatment in patients of idiopathic pulmonary arterial hypertension (IPAH) with positive acute pulmonary vasodilator test, and to compare the hemodynamic differences between the positive and negative patients.
Methods: A total of 156 consecutive IPAH patients with acute pulmonary vasodilator test were studied. The patients were divided into 2 groups according to the testing result. Positive group, n=23 and Negative group, n=133. The positive patients were followed up by clinical or telephone visit to investigate their CCB dose, WHO PAH cardiac classiifcation and the survival conditions. Kaplan-meier curve was conducted to analyze the living condition and t test was used to compare the hemodynamic differences between the positive and negative patients.
Results: There were 43 male and 113 female patients at the male/female ratio of 1: 2.6, and 14.7% (23/156) positive patients. The average follow-up period for Positive group was (50.9 ± 3.8) months. There were 13 patients using diltiazem with the mean dose of (277 ± 108) mg/d at the range of (90-450) mg/d; 3 patients using amlodipine, 1 with the dose of 15mg/d and 2 with the dose of 7.5mg/d. The 1, 2 and 3 years survival rate for the positive patients were for 91.3%, 86.6% and 79.7% respectively. The mean pulmonary arterial pressure and pulmonary vascular resistance were lower, P=0.000, while the mixed venous oxygen saturation was higher in Positive group than Negative group, P=0.009.The NT-pro BNP level was lower in Positive group, P=0.001.
Conclusion: IPAH patients has lower ratio of positive acute pulmonary vasodilator test. The positive patients has the higher 1, 3 and 5 years survival rate and better hemodynamic parameters as the mean pulmonary arterial pressure, pulmonary vascular resistance and better level of NT-pro BNP.

Objective To compare the differences in physical activity (PA), self-efficacy, stages of change and physical exercise behaviour in college students. Methods International physical activivty questionnaire( IPAQ), scales of self-efficacy, questionnaire of stage of change in physical exercise behaviour, and scales of physical behaviour were used to make a study on college students from Zhejiang province. Results The rate of males (40.43%) was signficant higher than that of females (26.09%) MET in the high activity tertile. There was significantly more energy expenditure in males (( 3462.79 ± 976.31 ) MET) than in females (( 3118.63 ±944.29 ) MET) (P ＜ 0.05 ). The rate of males (44.68 % ) was more than females (25.00%) in maintainanee period and period of action. PA characteristics were shown significant defferences in different stages (F= 31. 380, F=6.012, P ＜ 0.01 ). Characteristics in stages of change were shown high in behaviour score (F= 13.071, F= 7. 461,P ＜0. 01 ). Four factors as attitude,cognitive controls, behavior disposition and self-efficacy in males were entered into regression model of MET( t = 2.138 ～ 3. 789, P ＜ 0.05 ), while in females only the factor of behaviour attitude was entered. Conclusion There is significant difference in PA, stages of change, behaviour characteristics, and self-efficacy between male and female college students.

Aim To investigate the effect of intrauterine injection of rat fetal hepatocytes on homograft rejection reaction. Methods The skin graft from a male LOU/CN rat was transplanted to a female recipient CHN rat of 7 to 9 weeks after parturition, and then survival time of the graft was observed. Simultaneously, homograft rejection reaction was examined by mixture lymphocyte culture. Results As compared with control group, survival time of transplanted skin graft was obviously prolonged. Mixure lymphocyte culture demonstrated that homograft rejection reaction was inhibited markedly. Conclusion Intrauterine injection of rat fetal hepatocytes wuld obviously inhibite homograft rejection reaction, thus prolonging survival time of the graft.

Aim To screen peptides binding specifically to anti-human PTA1mAbs from a random twelve-peptide phage-disp-layed library. Methods Series of PTA1mAbs(LeoA1、 1B11、 C9、 2D1、 2E9、 2G8、 2H2 and E8)were purified using protein-A affinity column. PTA1mAbs which could bind PTA1-Fc fusion protein binding to its ligand were confirmed by flow cytometry, and then used as target to screen phage library. After three rounds of affinity screening, the peptide sequences of positive phage clones were determined and analyzed. Results LeoA1 could block PTA1-Fc fusion protein binding to its ligand. 13 phages which could bind specifically to LeoA1 were isolated from phage library and further confirmed by ELISA. Conserved motifs were found among the sequences of the peptides. Conclusion It was shown that the conserved motifs were candidafe regions binding to PTA1 ligand,which is important to identify functional epitopes for seeking ligand of PTA1 and further investigation of biological function of PTA1.