ve To investigate the effect of ischemic preconditioning (IPC) on apoptosis induced by acute myocardial ischemia/reperfusion and expressions of Bcl-2 and Bax protein which were known to modulate apoptosis. Methods Twenty-four healthy SD rats of either sex, weighing (200()20)g were anesthetized with intraperitoneal pentobarbital 4.5mg?100g-1. The animals were tracheotomized and mechanically ventilated. Respiratory rate was 20 bpm and tidal volume 2 ml?100g-1. Myocardial ischemia/ reperfusion(I/R) model was established by ligation and untying of the anterior descending branch of left coronary artery. The animals were randomly divided into three equal groups with eight animals each. Group I : (control group) anterior descending branch was exposed and dissected but not ligated and was exposed for 50 min. Group II (I/R group): anterior descending branch was double ligated for 30 min and then untied for reperfusion which lasted 2h. Group III (IPC group): The anterior descending branch was tied for 5 min then untied for 5 min and the process was repeated 4 times according to Murray's method, then I/R was produced as in group II. A piece of myocardium of 2 mm thick was cut from ischemia-infarct area. Apoptotic myocardial cells were detected by TdT-mediated dUTP-biotin nick end labeling (TUNEL) and the expressions of Bcl-2 and Bax protein were measured by immunohistochemical technique. Results I/R increased the percentage of apoptotic myocardial cells and the optical density (OD) value of Bax protein and decreased the OD value of Bcl-2 protein as compared with those in the control group. IPC reduced the increased percentage of apoptotic myocardial cells and OD value of Bax protein induced by I/R and increased the OD value of Bcl-2 protein as compared with those in the I/R group. Conclusions IPC can inhibit the apoptosis induced by myocardial I/R by modulating the expression of Bcl-2 and Bax protein.

Objective:To explore the relationship between the nitric oxide(NO)and the pathogenesis of the pulmonary hypertension(PH)induced by congenital heart disease(CHD). Method:NO content in plasma of CHD patient's pulmonory artery and superior vena cava was detected with NO kit. Result:NO content in the pulmonary artery of the patients with PH was much higher than that of patients without PH(37.58?9.99?mol/L vs 19.03?15.25?mol/L,P0.5). Conclusion:NO content in the pulmonary artery of CHD patients with PH increase,which may be involved in the pathogenesis of PH induced by CHD.

Objective To evaluate the effects of chronic exposure to sub-anesthetic concentrations of sevoflurane on memory function and homeostasis of mice.Methods Thirty-six healthy male Kunming mice,aged 40 days,weighing 25-30 g,were randomly assigned into 3 groups (n =12 each):control group (group C),0.1％ sevoflurane group (group L) and 0.5 ％ sevoflurane group (group H).The mice inhaled 0.1％ (group L) or 0.5％ sevoflurane (group H) between 18:00-6:00 (the next day) every night for 30 days.Water maze test was performed at 27-30 days of inhalation.Blood samples were collected from the left ventricle for blood gas analysis and for determination of blood electrolytes.Results There was no significant difference in swimming time in Water maze test,number of errors and blood gas analysis and blood electrolytes.Conclusion Chronic exposure to subanesthetic concentrations of sevoflurane has no significant effects on memory function and homeostasis of mice.

Objective To evaluate the relationship between the level of AMP-activated protein kinase (AMPK) in hippocampus and cognitive dysfunction after splenectomy in aged rats.Methods Sixty-three male aged Sprague-Dawley rats,weighing 480-550 g,were randomly divided into 3 groups (n =21 each):control group (group C),anesthesia group (group A),and surgery group (group S).Morris water maze (MWM) test was performed to evaluate the spatial learning and memory ability before surgery and at 1,3 and 7 days after surgery.The escape latency and swimming distance were recorded.Seven rats were chosen after MWM test was performed at 1,3 and 7 days after surgery and sacrificed.Their hippocampi were removed for detection of the expression of AMPK and phosphorylated (p-AMPK) (by Western blot).Results Compared with the baseline,the escape latency and swimming distance were significantly prolonged at 1 and 3 days after surgery in group S (P ＜ 0.05).Compared with group C,the escape latency and swimming distance were significantly prolonged at 1 and 3 days after surgery,the expression of AMPK was up-regulated at 1,3 and 7 days after surgery,and the expression of p-AMPK was up-regulated at 1 and 3 days after surgery in group S (P ＜ 0.05),and no significant changes were found in the indices mentioned above in group A (P ＞ 0.05).Conclusion Increased AMPK level in hippocampus is the regulatory mechanism of the body adapting to the development of cognitive dysfunction after splenectomy in aged rats.

Due to its advantages of low wear, high stability and flexibility, the new generation metal-on-metal hip prosthesis is favored by many patients with hip diseases, especially young patients. However, in recent years, several studies have indicated that adverse reactions to metal debris (ARMD) caused the formation of inflammatory pseudotumor, which ultimately led to a higher revision rate after metal-on-metal hip arthroplasty. This aroused the widespread concern from doctors and patients. Moreover, revision surgery for metal-on-metal hip arthroplasty in the setting of inflammatory pseudotumor is faced with a great risk of failure because of the large defects of bone and surrounding soft tissue and difficulty in removing the original prosthesis and the fixing of the modified prosthesis. Therefore, the use of such products is restricted with caution in their choice. We summarized the recent developments in the research in the risk factors, diagnosis and treatment of inflammatory pseudotumor after metal-on-metal hip arthroplasty. The risk factors for the formation of inflammatory pseudotumor around the hip prosthesis mainly include the increase of metal ion concentration, the position of prosthesis implantation and the patient's own factors. The diagnosis mainly depends on physical examination, imaging examination, laboratory examination, arthroscopy and histological examination. The treatment strategies for clinical symptomatic and asymptomatic patients are also varies. Through the detailed analysis, evaluation and summary of the above contents, we may provide guidance for the selection of hip prosthesis, and lay the foundation for further exploration of the mechanism of inflammatory pseudotumor caused by ARMD.

Objective To investigate the mid-and long-term effects of metal-on-metal hip resurfacing arthroplasty (HRA),and to analyze its related factors.Methods A total of 64 patients (81 hips) who underwent metal-on-metal HRA from June 2005 to January 2013 were recruited in the present study.There were 35 males (44 hips) and 29 females (37 hips) with the mean age of 48.26±10.45 years (20-65 years),including 47 unilateral and 17 bilateral HRAs.The cohort consisted of osteoarthritis secondary to the developmental dysplasia of the hip (23 cases,29 hips),necrosis of the femoral head (19 cases,22 hips),osteoarthritis (8 cases,10 hips),rheumatoid arthritis (5 cases,9 hips),ankylosing spondylitis (6 cases,8 hips),pigmented villonodular synovitis (2 cases,2 hips) and Otto's disease (1 case,1 hip).During the follow-up duration,radiographic features,including acetabular inclination angle,stem-femoral shaft angle,component loosening,osteolysis,femoral neck narrowing and heterotopic ossification,were evaluated by hip X-rays in straight and froglike position.The size and type of pseudotumor were assessed by MRI and ultrasonography.Clinical efficacy was evaluated by Harris hip score and the University of California at Los Angeles (UCLA) hip score.Considering revision surgery as the end point,the component survivorship was calculated.Results The mean follow-up was 7.98±2.21 years,ranging from 5.0 to 12.8 years.The mean postoperative Harris hip score (92.01 ±5.69) was higher than the preoperative score (41.93 ±9.09).The mean postoperative UCLA pain,walking,function,activity scores (9.37±0.86,9.14± 1.01,8.77± 1.09,6.47± 1.27,respectively) were improved when compared with the preoperative UCLA scores (3.57± 1.23,5.99± 1.30,5.00± 1.01,3.84± 1.41,respectively).The postoperative flexion,abduction and adduction,medial and lateral rotation of the hip was larger than the preoperative ones.Complications occurred in 10 hips (12.3％,10/81).Seven patients (8 hips) experienced early and intermediate complications,including one intraoperative femoral nerve injury,one deep femoral artery and saphenous nerve injuries during the same surgery,one unexplained pain of hip,one femoral neck fracture,three hips of heterotopic ossification,and one pseudotumour.There were mid-and long-term complications in two hips,including one narrowing of the neck and one pseudotumour which was occurred at 9 years.There was one patient (2 hips) underwent revision surgery twice at 5 months and 9 years.The former cause of revision was femoral neck fracture and the latter one was pseudotumour.The Kaplan-Meier survivorship was 98.8％ at five years,and 95.0％ at ten years.Conclusion Patients who underwent metal-on-metal HRA could obtain good mid and long-term results.Pseudotumour and unexplained pain of the hip are critical factors which can affect the mid-and long-term results and survivorship of metal-on-metal HRA.

Objective: To investigate the current status of picky eating among children and family-related factors, to provide scientific basis for diet intervention for children. Methods: A total of 1 829 children were selected from 5 kindergartens in Shenzhen and investigated by electronic questionnaire survey from March 18 th-20 th in 2020.The data was analyzed by SPSS 21.0. Results: The reported rate of picky eating behavior among children was 43.8%. Parents-picky eating behavior, children s preference to eating snacks, parental worries on children s appetite, parents attitude toward the food disliked by children were positively correlated to children s picky eating behaviors[OR(95%CI)=3.86(2.74-5.43), 1.44(1.15-1.80), 3.21(2.45-4.22), 2.21(1.65-2.95)]; however, eating various food under the instruction of their parents was negatively correlated to children s behaviors[OR(95%CI)=0.38(0.29-0.49)](P<0.05). Conclusion The reported rate of picky eating behaviors of children on holiday is lower than usual, but parents should to help them develop good dietary habits, prevent picky eating among children.

Objective: To investigate eating behavior and associated family factors of preschool children during the prevalence of Corona Virus Disease(COVID-19), and to provide scientific basis for healthy eating behavior for preschool children. Methods: A total of 1 829 preschool children were investigated by electronic questionnaire from 5 kindergartens in Shenzhen from March 18-20, 2020. SPSS 19.0 was used to perform logistic regression analysis on the factors for eating behavior. Results: The rate of unhealthy eating behavior during the prevalence of COVID-19 was 47.2%. The rate of unhealthy eating behaviors in boys and girls were 46.1% and 48.4%, respectively. And there was no significant difference between different genders(χ 2=1.02，P=0.31). The rate of unhealthy eating behaviors of preschool children aged 3-, 4-, 5- and 6- were 56.6%, 56.8%, 42.3% and 29.9%, respectively, and the differences between different ages were significant(χ 2=72.17，P<0.01). Logistic regression analysis showed that fathers high education level, mothers education level(OR=0.78，0.77，0.21), and parents satisfaction with children s eating were associated with low nutritional problems of child, while parental permission to play while eating, criticize while eating, force child to eat more and force child to eat foods they do not like, and parental concerns about children s appetite, were associated with more unhealthy eating behavior(OR=6.29，1.80，2.20，1.70，2.16)(P<0.05). Conclusion The prevalence of unhealthy eating behaviors of preschool children during the prevalence of COVID-19 is lower than usual, but the health education of preschool children s families still needs to be strengthened.

【Objective】 To explore the effect of health education intervention measures on improving parents′ perception of their children′s weight, so as to provide scientific basis for intervention in preschool obese children. 【Methods】 Children from 7 kindergartens in Luohu district were randomly selected in this study in October 2020, and were divided into intervention group and control group. The intervention group consisted of 1 318 children and parents from 3 kindergartens, and the control group consisted of 1 546 children and parents from 4 kindergartens. Parents in the intervention group received combination of online and offline health education intervention measures for 2 months, while parents in the control group received no intervention measures. Logistic regression analysis was used to evaluate the effect of parents′ perception of their children′s weight in intervention group and control group. 【Results】 After controlling for imbalanced variables such as parents′ education level, total monthly family income, and parents′ perception of their children′s weight, there was a statistically significant difference in the improvement of parents′ perception of their children′s weight status between two groups after intervention(OR=2.175, 95%CI: 1.536 - 3.080, P<0.05). After intervention, the improvement of parents′ perception of boys′ weight status in intervention group was better than that in control group(OR=2.985, 95%CI: 1.878 - 4.745, P<0.05). There was no statistically significant difference in the degree of improvement in perceived weight status among girls′ parents after intervention(P>0.05). Regardless of whether the child′s weight status was normal or not, parents in the intervention group showed better improvement in their perception of their children′s weight status than the control group(OR=1.558, 6.111, 95%CI:1.025 - 2.368, 2.811 - 13.287, P<0.05). 【Conclusion】 Health education measures can improve the perception bias of parents towards their preschool children′s weight, and the intervention effect varies among children of different genders and weight states.