BACKGROUND:The research of dental stem cells in the fields of regenerative medicine and tissue engineering has been deepening,bringing hope for the repair of tooth-related tissues and the treatment of systemic diseases.However,there is a lack of systematic research and analysis on the biological characteristics of dental stem cells in different age groups. OBJECTIVE:To explore the biological characteristics of the human deciduous tooth and permanent tooth pulp stem cells cultured in umbilical cord blood platelet lysate to provide a reliable basis for human platelet lysates to replace fetal bovine serum. METHODS:The pulp tissues of deciduous teeth,juvenile permanent teeth and adult permanent teeth were taken out and cultured in DMEM/F-12 medium supplemented with 10%fetal bovine serum or different concentrations(5%,10%and 15%)of human platelet lysates.Cell proliferation in the four groups was detected by cytometry.The optimal concentration of human platelet lysates was selected for subsequent experiments.Under the optimal concentration of human platelet lysates,human deciduous tooth and juvenile and adult permanent tooth pulp stem cells were cultured in vitro.The cell growth status was observed under the microscope.The specific antigen on the cell surface was detected by flow cytometry.The cell proliferation ability was tested by the cell counting method and CCK-8 assay.The cell differentiation ability in vitro was observed by a three-line differentiation assay. RESULTS AND CONCLUSION:(1)The cell proliferation rate of the 10%human platelet lysate group was the highest.(2)In all three groups,fusiform fibrous cells grew and expanded from around the tissue block.There was no significant difference between deciduous teeth and juvenile permanent tooth cells,but the adult permanent tooth cells were larger than the deciduous and juvenile permanent tooth cells of the same generation.(3)The results of flow cytometry showed that deciduous teeth,juvenile permanent teeth and adult permanent teeth conformed to the phenotypic characteristics of mesenchymal stem cells.(4)The proliferative capacity of adult permanent dental pulp stem cells was significantly lower than those of deciduous teeth and juvenile permanent dental pulp stem cells(P<0.01).(5)mRNA expressions of osteoblast-related genes alkaline phosphatase and bone morphogenetic protein 2,lipoprotein lipase and peroxisome proliferator-activated receptor γ2,mRNA expressions of chondroblast related gene type II collagen α1 and cartilage oligomeric matrix protein in adult pulp stem cells of permanent teeth were significantly lower than those of deciduous teeth and juvenile permanent teeth pulp stem cells(P<0.01).(6)Compared with adult dental pulp stem cells,human deciduous teeth and juvenile permanent teeth dental pulp stem cells have the stronger proliferative capacity and multidirectional differentiation potential,and are more suitable for clinical research and disease treatment.

Objective:To explore the effects of small-group collaborative stratified teaching in critical care medicine training for professional postgraduate students.Methods:We randomly assigned 71 professional postgraduate students who entered the Intensive Care Unit of The Affiliated Hospital of Qingdao University for standardized training between June 2020 and November 2020 into experimental group and control group. An entrance examination was taken after one week of unified training. Then the experimental group adopted small-group collaborative stratified teaching, while the control group adopted traditional teaching for training. After two months of training, the Mini-Clinical Evaluation Exercise (Mini-CEX) assessment, post competency assessment, exit examination, and teaching satisfaction evaluation were conducted. SPSS 25.0 was used for the t test and chi-square test. Results:In the Mini-CEX assessment, the experimental group had significantly higher scores in history-taking skills [(7.42±0.60) vs. (7.00±0.55)], physical examination [(7.47±0.56) vs. (6.94±0.24)], communication skills [(7.56±0.50）vs.(7.24±0.49)], clinical dialectical thinking [(7.53±0.56) vs. (7.03±0.39)], clinical judgement [(7.50±0.51) vs.(6.90±0.42)], organization/efficiency [(7.58±0.50) vs. (7.15±0.44)], and overall clinical competence [(7.64±0.49) vs. (7.17±0.39); all P<0.05] than the control group. In the post competency assessment, the experimental group had significantly better performance in clinical basic competence [(89.15±9.12) vs. (86.24±10.23)], medical knowledge application [(48.37±5.87) vs. (46.98±3.68)], teamwork [(48.10±3.55) vs. (45.96±4.83)], information and management [(68.52±7.61) vs. (66.38±5.54)], and academic research [(22.18±0.95) vs. (20.87±1.22); all P<0.05] than the control group. The experimental group was also significantly superior to the control group in terms of the exit examination score and teaching satisfaction (both P<0.05). Conclusions:Small-group collaborative stratified teaching can improve the quality of critical care medicine training for professional postgraduate students, and strengthen their clinical comprehensive abilities and post competencies.

Purpose: The interval between neoadjuvant chemotherapy (NAC) and surgery for locally advanced breast cancer (LABC) remains controversial. At the same time, the prognostic effect of delayed surgery in patients with poor responses is currently unclear. Methods: Data was collected from patients who had poor responses to NAC and underwent modified radical surgery from January 2013 to December 2018. The interval from completion of NAC to surgery was divided into two groups: a longer (greater than four weeks) or shorter (four weeks or less) interval. The associations of these interval groups with overall survival (OS) and recurrence-free survival (RFS) were evaluated by multivariable Cox models adjusting for the existing prognostic factors. Propensity score matching (PSM) was used to minimize election bias. Results: A total of 1,229 patients (mean age, 47.2 ± 8.9 years; median follow-up duration, 32.67 [6.57–52.63] months) were included. The 5-year OS rates were 73.2% and 60.8% in the shorter (n = 171) and longer interval group (n = 1,058), respectively, while the 3-year RFS rates were 80.8% and 71.7%, respectively. In multivariate Cox analysis, the longer interval was associated with an increased risk of mortality (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.01–2.02; p = 0.046) and recurrence (HR, 1.50; 95% CI, 1.12–1.99; p = 0.006).There was an interaction between the molecular subtype and the surgery interval for OS (pinteraction = 0.014) and RFS (pinteraction = 0.027). After PSM, no significant difference in OS (p = 0.180) and RFS (p = 0.069) was observed between the two groups. Conclusion Among LABC patients with a poor response, those with a longer interval between NAC and surgery had worse OS and RFS. The results indicate that these patients should receive modified radical surgery timely, which may in turn improve their prognosis.

Objective:To compare the efficacy between deep continuous irrigation combined with vacuum sealing drainage (VSD) and routine dressing change in treating multidrug-resistant bacterial infections at the surgical wound site in patients with major vascular injury.Methods:A retrospective cohort study was conducted to analyze the clinical data of 28 patients with surgical wound infections by multidrug-resistant bacteria after major vascular injury treated at the First Affiliated Hospital of Henan University of Science and Technology from March 2015 to December 2021. There were 15 males and 13 females, aged 15-65 years [(41.8±12.9)years]. All patients received vascular graft surgery after major vascular injury. Postoperative microbiological culture indicated that the wound infections were caused by Carbapenem-resistant organisms (CRO) or vancomycin- resistant Enterococci (VRE), with no available sensitive antibiotics for treatment. The patients received surgical debridement every five days after vascular graft surgery and were divided into two groups to receive the subsequent treatments including a routine dressing change (routine dressing group, 14 patients) or a deep continuous irrigation combined with VSD (irrigation combined with VSD group, 14 patients). On the first day post-operation and then every 3 days, inflammatory indicators [white blood cell count, neutrophils, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and procalcitonin] were observed in the two groups (repeat tests when a patient′s condition changed). Microbiological cultures were applied with patient samples every 5 days to observe the wound and infection control. Comparisons were made between the two groups regarding the duration to normal levels of inflammatory indicators, duration to negative CRO or VRE cultures, visual analogue score (VAS) before and at 1, 2 and 3 hours after changing the irrigation fluid (changing the dressing), conditions of wound skin grafting or flap repair, and incidences of anastomotic fistula.Results:All patients were followed up for 12-24 months [(14.3±2.4)months], during which no wound redness, rupture, purulent discharge or infection recurrence was noted. The duration to normal levels was (9.4±2.4)days for white blood cells, (9.6±2.8)days for neutrophils, (9.8±3.1)days for CRP, (12.2±3.6)days for ESR, and (7.6±1.9)days for procalcitonin in the irrigation combined with VSD group, significantly shorter than those in the routine dressing group [(15.2±3.1)days, (13.6±3.4)days, (14.2±3.9)days, (19.9±3.3)days, and (12.9±4.1)days, respectively] (all P<0.01). The duration to negative CRO or VRE cultures was (13.9±3.1)days in the irrigation combined with VSD group, significantly shorter than that in the routine dressing group [(19.2±6.9)days] ( P<0.05). The VAS before and at 1, 2 and 3 hours after changing the irrigation fluid was (4.2±0.7)points, (4.1±0.9)points, (4.2±0.9)points and (4.1±0.8)points in the irrigation combined with VSD group, respectively, and was (4.3±0.6)points, (6.9±0.7)points, (5.4±0.9)points and (4.5±0.9)points in the routine dressing group, respectively. The VAS score in the irrigation combined with VSD group was significantly lower than that in the routine dressing group at 1 hour and 2 hours after changing the irrigation fluid (all P<0.01), while no significant differences were found before and at 3 hours after changing the irrigation fluid (all P>0.05). After infection control, 5 patients (35.7%) in the irrigation combined with VSD group required skin grafting or flap repair at the wound site, lower than 11 patients (78.6%) in the routine dressing group ( P<0.01). The incidence of anastomotic fistula was 7.1% (1/14) in the irrigation combined with VSD group, lower than 42.9% (6/14) in the routine dressing group ( P<0.05). Conclusion:When multidrug-resistant bacterial infections occur at the surgical wound site after major vascular injury, deep continuous irrigation combined with VSD performs better than routine dressing change in controlling infection as well as in reducing pain, rate of wound skin grafting or flap repair and incidence of anastomotic fistula, without reliance on antibiotics.

Objective:To evaluate the clinical effects of posterior reduction in the treatment of acute severe traumatic lumbar spondylolisthesis.Methods:A retrospective study was conducted to analyze the clinical data of 12 patients with acute severe traumatic lumbar spondylolisthesis who had been treated by posterior reduction at Department of Spinal Surgery, Zhengzhou Orthopaedic Hospital from June 2010 to December 2018. There were 7 males and 5 females with an age of (25.7±1.8) years. The spondylolisthesis was at L4 in 4 cases and at L5 in 8 cases, and grade Ⅲ in 7 cases, grade Ⅳ in 4 cases and grade Ⅴ in 1 case according to the Meyerding classification. By the American Spinal Injury Association (ASIA) grading, the preoperative neurological function was at level B in 6 cases, at level C in 4 cases, and at level D in 2 cases. All the 12 patients underwent posterior reduction and internal fixation with pedicle screws, as well as intervertebral bone graft fusion. Operation time and intraoperative blood loss were recorded. Clinical efficacy was evaluated by visual analogue scale (VAS) and Oswestry disability index (ODI) before and after surgery, and neurological function was evaluated by ASIA grading. X-ray, CT plain scan and reconstruction were used to observe internal fixation and bone grafting.Results:All patients were followed up for (18.5±2.1) months. The operation time was (165.7±42.3) min and the blood loss (497.7±75.3) mL. The VAS pain scores [(2.7±0.3) points and (1.8±0.2) points] and ODIs (18.2%±2.3% and 14.5%±2.6%) at 2 weeks after operation and at the last follow-up were significantly lower than the preoperational values [(8.5±0.6) points and 72.3%±12.3%] ( P<0.05), but there was no statistically significant difference between 2 weeks after operation and the last follow-up ( P>0.05). At the last follow-up, X-rays and CT scans showed good fixation and adequate bone grafting; the spondylolisthesis was grade 0 in 10 cases and grade I in 2 cases; the ASIA level of neurological function was C in 2 cases, D in 3 cases, and E in 7 cases. Healing of surgical incision was delayed in 2 patients but responded to symptomatic treatment. Follow-ups observed no such complications as loosening or pulling out of internal fixation. Conclusion:In the treatment of acute severe traumatic lumbar spondylolisthesis, posterior reduction can effectively restore the spondylolisthesis sequence and restore spinal stability, leading to satisfactory curative outcomes.

Objective:To establish a nomogram prediction model for the prognosis of patients with septic cardiomyopathy (SCM) based on afterload-corrected cardiac performance (ACP), in order to identify septic patients with poor outcomes and treatment.Methods:The data of patients admitted to the department of critical medicine of the Second Affiliated Hospital of Guangzhou Medical University from June 2016 to June 2019 were analyzed. All patients were monitored by pulse indication continuous cardiac output (PiCCO) monitor more than 24 hours and diagnosed as SCM with ACP less than 80%. The predictors of 30-day death risk of SCM patients were screened by univariate Cox regression analysis. Multivariate Cox regression analysis was used to establish the prediction model for 30-day death risk of SCM patients, which was displayed by the nomogram. Finally, the discrimination and calibration of the model were analyzed by receiver operator characteristic curve (ROC curve) and consistency index (C-index).Results:A total of 102 patients with SCM were included and the 30-day mortality was 60.8% (62 cases). Among 102 patients with SCM, 57 patients (55.9%) had mild impairment of cardiac function (60%≤ACP < 80%), and the 30-day mortality was 43.9% (25/57); 39 patients (38.2%) had moderate impairment of cardiac function (40%≤ACP < 60%), and the 30-day mortality was 79.5% (31/39); 6 patients (5.9%) had severe impairment of cardiac function (ACP < 40%), and the 30-day mortality was 100% (6/6). There was significantly difference in mortality among the three groups (χ 2 = 24.156, P < 0.001). The potential risk factors for 30-day death of SCM patients screened by univariate Cox regression analysis were included in multivariate Cox regression analysis. The results showed that the independent risk factors for 30-day death of SCM patients were acute physiology and chronic health evaluation Ⅱ [APACHEⅡ, risk ratio ( HR) = 1.031, 95% confidence interval (95% CI) was 1.002-1.061, P = 0.039], vasoactive inotropic score (VIS, HR = 1.003, 95% CI was 1.001-1.005, P = 0.012), continuous renal replacement therapy (CRRT; HR = 2.106, 95% CI was 1.089-4.072, P = 0.027), and ACP ( HR = 0.952, 95% CI was 0.928-0.977, P < 0.001). The nomogram model was established based on the above independent risk factors and age, and the area under the curve (AUC) was 0.865 (95% CI was 0.795-0.935), P < 0.001; C-index was 0.797 (95% CI was 0.747-0.847), P > 0.05. Conclusions:The nomogram model based on age, APACHEⅡ score, VIS score, CRRT and ACP has a certain clinical reference significance for the prediction of 30-day mortality of SCM patients. The discrimination and calibration are good, however, further verification is needed.

Objective To observe the effects of electro-acupuncture on loading of lower limb joints in patients with knee osteoarthritis (KOA) during stair climbing and explore the related biomechanical mechanism. Methods Forty patients with KOA were randomly assigned, with 20 patients in observation group (electro-acupuncture group, EA group) and 20 patients in control group (superficial acupuncture group, SA group). Finally 18 patients in each group completed the study. In observation group, seven knee acupuncture points were chosen and patients were connected with electro-acupuncture instrument; while in control group, the electro-acupuncture instrument was connected but not electrified after superficial acupuncture at non-acupoint points. The three-dimensional gait analysis system was used to assess the biomechanical characteristics during stair climbing before and after treatment, including peak vertical force (PFz), vertical impulse (IFz) and symmetry index (SI%). Results After 3 weeks of treatment in EA group, PFz of the right foot during stair ascent and PFz of the left foot during stair descent increased (P＜0.05); IFz of both feet during stair ascent and IFz of the right foot during stairs descent significantly decreased (P＜0.05); no significant differences were found in SI% of peak and impulse (P＞0.05). In SA group, only SI of impulse during stairs ascent increased (P＜0.05). There was no significant difference between two groups before and after treatment (P＞0.05). Conclusions Electro-acupuncture can effectively improve the joint load capacity and reduce the dynamic cumulative load of patients w

Objective:To investigate the relationship between 1-hour lactate (1 h Lac) and 30-day mortality in critical care patients in intensive care unit (ICU).Methods:A retrospective, observational cohort study was performed with adult critical patients (age ≥ 16 years old) having lactate records within 1 hour after ICU admission from Medical Information Mart for Intensive Care-Ⅲ database (MIMIC-Ⅲ). According to the 1 h Lac level, the patients were divided into three groups: < 2 mmol/L, 2-4 mmol/L, and > 4 mmol/L groups. The baseline characteristics were analyzed. Multivariable Logistic regression analysis was performed to assess the association between 1 h Lac and 30-day mortality. The receiver operating characteristic (ROC) curve was used to analyze the predictive value of 1 h Lac for 30-day mortality, and Kaplan-Meier survival curve was performed according to the best cut-off value. In addition, sensitivity analysis was carried out for each classification variable.Results:A total of 3 969 ICU patients were included, with 673 died in 30 days, and the total mortality was 16.95%. There were 1 664, 1 588, 717 patients in Lac < 2 mmol/L, 2-4 mmol/L and > 4 mmol/L group, respectively. There were significant differences in age, ICU duration, ICU type, heart rate, leukocyte count, hemoglobin, creatinine, sequential organ failure score (SOFA), ventilator application, vasoactive drug use and main diagnosis among the three groups. Multivariable Logistic regression analysis showed that a 1 mmol/L increment in Lac was associated with 0.24 times higher risk of 30-day mortality [odds ratio ( OR) = 1.24, 95% confidence interval (95% CI) was 1.19-1.29, P < 0.000 1]. ROC curve analysis showed that the area under ROC curve (AUC) of 1 h Lac for predicting 30-day mortality of severe patients was 0.694 (95% CI was 0.669-0.718). The cut-off value was 3.35 mmol/L with sensitivity of 0.499 and specificity of 0.779, whilst positive likelihood ratio was 2.260, and negative likelihood ratio was 0.643. According to the cut-off value of 1 h Lac, the patients were divided into high lactate group (≥ 3.35 mmol/L) and low lactate group (< 3.35 mmol/L). In the two subgroups, 30-day mortality was 31.58% (336/1 064) and 11.60% (337/2 905), respectively. The Kaplan-Meier survival curve showed that the 30-day cumulative survival rate of high lactate group was significantly lower than that of low lactate group (Log-rank test: χ 2 = 247.72, P < 0.000 1). Multiple Logistic regression analysis showed that the 30-day mortality rate of high lactate group was 2.34 times that the level of low lactate group ( OR = 2.34, 95% CI was 1.90-2.88, P < 0.000 1), after the adjustment of age, time of admission, type of ICU, hemoglobin, leukocyte count, use of vasopressor, use of ventilator and main diagnosis of patients. Stratified analysis showed that the relationship between 1 h Lac and 30-day mortality was stable. Conclusions:1 h Lac is associated with 30-day mortality in critical care patients. The risk of death was significantly increased in critically ill patients with 1 h Lac higher than 3.35 mmol/L.

Objective:To explore the COVID-19 knowledge and attitude, and its influences on protective behavior among clinical nurses so as to provide a reference for developing effective intervention strategy.Methods:Cross-sectional investigation was used to hospital-wide nurses selected by convenience sampling in February 2020 through sending a link of Wenjuanxing to work WeChat group of Nursing Department of Beijing Hospital and to circle of friends. Clinical nurses met the inclusion and exclusion criteria were invited to fill in the questionnaire. The self-designed COVID-19 related knowledge, attitude and behavior questionnaire was used to the investigation.Results:Among 750 clinical nurses, the self-assessment of COVID-19 related knowledge was≥7, with 70.04% for the average percentage. There were 91.6% of nurses with the confidence to fight with epidemic situation. After COVID-19 broke out, 94.1% of nurses strictly carried out the hand hygiene. Behavior changes in "wearing gloves when potentially contacting bloods, body fluids, secretions and excreta", "wearing goggles and protective clothing when bloods, body fluids, secretions and excreta potentially splashing" accounted for 89.2%, 81.5% and 71.6% respectively. Pearson correlation analysis showed that COVID-19 related knowledge of 750 nurses had no correlations with three dimensions "worrying about infecting COVID-19", "effectiveness of standard precaution" and "influencing factors of taking standard precaution" of attitude with no statistical differences ( P>0.05) . The results showed that the clinical knowledge of the first-line nurses of COVID-19 had no impact on the implementation of hand hygiene, but also had impacts on their attitudes ("views on dealing with the epidemic of COVID-19" dimension) and protective behavior habits ( P<0.05) ; their attitudes had no effect on the implementation of hand hygiene, and had impacts on other protective behavior habits ( P<0.05) . Conclusions:COVID-19 related knowledge of clinical nurses need to be improved and protective behavior should be changed further.

Objective:To explore the level of evidence-based nursing practical ability of nurses in Class Ⅲ Grade A hospitals and its influencing factors.Methods:From August to September 2019, the cluster sampling was used to survey 1 187 nurses in 6 Class Ⅲ Grade A hospitals in Beijing using general information questionnaire, Evidence-Based Nursing Practice Ability Scale, Evidence-Based Nursing Awareness and Training Demand Questionnaire. Univariate analysis and multivariateregression analysis were used to explore the influencing factors of evidence-based nursing practice ability.Results:Among the 1 187 nurses participating in the survey, 24.6% (292/1 187) had participated in academic activities related to evidence-based nursing. 70.2% (205/292) of nurses whose cumulative training hours were less than or equal to 10 hours, and the training was mainly in the form of academic lectures in the hospital. Only 5.0% (59/1 187) were "well-know" and " very familiar" with evidence-based nursing, and 30.8% (366/1 187) believed that continuous and systematic evidence-based special training was needed. The total score of evidence-based nursing practice ability of 1 187 nurses was (38.71±27.11) . The univariate analysis showed that there were statistically significant differences in the scores of nurses with different research experiences, gender, participation in academic activities related to evidence-based nursing, duration of participation in evidence-based nursing training, age, first degree, professional title and foreign language proficiency ( P<0.05) . Multiple regression analysis showed that the main factors affecting nurses' evidence-based nursing practice ability were research experience, the length of time they had participated in evidence-based nursing training, age, first degree and foreign language proficiency. Conclusions:In this study, the practice ability of nurses is low, but their willingness to implement evidence-based nursing is strong. It is suggested that nursing managers should carry out systematic training of evidence-based nursing according to the different abilities of nurses, especially in the aspect of evidence integration, and actively cultivate evidence-based nursing talents.