BACKGROUND: Uncontrolled-rate freezing in -80 ℃ refrigerator is convenient, while controlled-rate freezing in -196 ℃ liquid nitrogen is reliable and long-term, the combination of the two can simplify the process and has been successfully used in clinics. OBJECTIVE: To explore the influences of different cryoprotectants by ladder-style freezing from -80 ℃ low temperature refrigerator to liquid nitrogen on the cryopreservation of hemopoietic stem cells. METHODS: The experiments were divided into four groups: 10% dimethyl sulfoxide (DMSO) group, 5% DMSO combined with 3% hydroxyethyl starch group, 5% DMSO combined with 0.25 mol/L trehalose group, 5% DMSO combined with 3% hydroxyethyl starch and 0.25 mol/L trehalose group. Peripheral hemopoietic stem cells were cryopreserved by ladder-style freezing from -80 ℃ low temperature refrigerator to liquid nitrogen. The ultrastructural changes were examined by transmission electron microscopy, the expressions of Annexin-V, PI and Caspase-3 were detected by flow cytometry. RESULTS AND CONCLUSION: There was no significant difference in survival rate, apoptotic rate and necrotic rates of the cryopreserved cells in the four groups (P > 0.05). The ultrastructural changes had no significant difference under the transmission electron microscopy. The viability was more than 90% in frozen-thawed mononuclear cell colonies, and the apoptosis was roughly 50% in the frozen-thawed CD45+ cell population, which contained many mature cells. Of hemopoietic stem cells, early stage cells have greater resistance to damage of cryopreservation than late stage cells. It is concluded that the addition of hydroxyethyl starch or trehalose into DMSO exhibits no synergistic protective effect on the cryopreservation of hemopoietic stem cells.

ObjectiveTo investigate the predictive value of heart rate turbulence(HRT) in patients with diabetes mellitus (DM) after acute myocardial infarction (AMI).MethodsNinety-two AMI patients combined with DM (DM group) and 120 AMI patients without DM (non-DM group) were selected.Turbulence onset (TO) and turbulence slope (TS) were two indexes of HRT.HRT was considered positive when TO was ≥0 and TS was ≤2.5 ms/R-R.The differences in clinical data between HRT-positive and HRT-negative patients were compared.And the related risk factors after AMI were analyzed.ResultsAge,left ventricular ejection fraction (LVEF) level,renal insufficiency,LVEF＜40％,standard deviation of sinus cardiac cycle (R-R interval)(SDNN),heart rate variability (HRV) positiveand HRT indexes (TO,TS) between HRT-positive and HRT-negative patients in DM group had significant differences (P ＜ 0.05 ).Age,LVEF level,SDNN and HRT indexes(TO,TS) between HRT-positive and HRT-negative patients in non-DM group had significant differences(P ＜ 0.05).Multivariate Cox regression analysis showed that renal insufficiency (OR=4.8,95％ CI:1.8 - 10.7,P=0.008) and HRT positive (OR=3.7,95％ CI:1.5 - 8.6,P=0.070) in DM group had statistical significance.And HRT positive in non-DM group had statisticalsignificance(OR=23.0,95％ CI:5.2 ～ 86.0,P ＜ 0.01 ).ConclusionsHRT,an index of dynamic electrocardiogram,can predict the risk in patients with DM or without DM after AMI.

Objective:To investigate the current status and influencing factors of kinesiophobia in adult burn patients.Methods:A single center cross-sectional research method was conducted. A total of 170 adult burn patients, meeting the inclusion criteria, were admitted to the Department of Plastic Surgery and Burns of the West China Hospital of Sichuan University from October 2018 to December 2019. On admission, the self-made general information questionnaire was used to investigate the gender, age, education level, marital status, payment method of medical expenses, injury factors, and total burn area of patients. One month after admission or before discharge, the presence and degree of kinesiophobia of patients were evaluated by the Tampa Scale for Kinesiophobia (TSK), their pain degrees (results averaged) at the time of burn, debridement and dressing change, after burn operation, and at rest were evaluated by the Visual Analogue Scale, their social support levels were evaluated by the Social Support Revalued Scale, and their degrees of anxiety and depression were evaluated by the Hospital Anxiety and Depression Scale. According to the TSK score, the patients with score >37 points were included into kinesiophobia group, and the patients with score ≤37 points were included into non-kinesiophobia group. The general information of patients in the two groups, as well as the pain score, social support level score, anxiety score, and depression score mentioned above, were recorded. Data of patients between the two groups were statistically analyzed with unifactor analysis including chi-square test, independent sample t test, and Mann-Whitney U test. The factors with statistically significant differences in unifactor analysis were used as variables for multivariate logistic regression analysis to screen out the independent influencing factors of kinesiophobia in adult burn patients. Results:Questionnaires and scales of 170 patients were collected, and the recovery rate was 100%. The data of two patients complicated with cranial fracture aggravation were removed, and 168 valid data were obtained, with the effective rate of 98.82%. Among the 168 patients, 88 were male (52.38%) and 80 were female (47.62%), aged from 18 to 71 (41±6) years. Most of the patients had secondary school education or below, were married, and with no out-of-pocket medical expenses. The main factors of injury were flame and hydrothermal fluid, and the total burn area was 2%-75% ((28±5)%) total body surface area. The TSK score was (41±5) points, the pain score was 4.0 (2.6, 7.0) points, the social support level score was (40±5) points, the anxiety score was 8.5 (7.0, 13.0) points, and the depression score was 9.5 (6.5, 12.0) points. A total of 98 patients had kinesiophobia, and the incidence of kinesiophobia was 58.33%. There were no statistically significant differences in gender, age, educational level, marital status, or injury factors of patients between kinesiophobia group and non-kinesiophobia group ( P>0.05). The percentage of out-of-pocket expenses, total burn area, pain score, anxiety score, and depression score of patients in kinesiophobia group were significantly higher than those in non-kinesiophobia group ( χ2=6.402, t=2.39, Z=-8.05, -6.68, -7.89, P<0.05 or P<0.01), and the social support level score of patients in kinesiophobia group was significantly lower than that in non-kinesiophobia group ( t=5.22, P<0.01). The multivariate logistic regression analysis showed that total burn area, pain score, social support level score, anxiety score, and depression score were the independent influencing factors for the development of kinesiophobia in adult burn patients (odds ratio=0.79, 1.45, 0.78, 1.15, 1.17, 95% confidence interval=0.80-0.92, 1.24-1.74, 0.65-0.91, 1.06-1.29, 1.03-1.24, P<0.01). Conclusions:The incidence of kinesiophobia in adult burn patients is high, and the degree of kinesiophobia is mainly affected by total burn area, pain, social support level, anxiety and depression degrees, and so on. Thus these factors should be taken into consideration when designing interventions to reduce the incidence and degree of kinesiophobia.