Objective To clarify malaria infection and the incidence in first Chinese medical team of United Nation peacekeeping mission in Democratic Republic of Congo and evaluate the effect of prevention measures so that provide reference for studying on malaria prevention and the precautionary measures for the follow-up personnel in Africa. Methods 43 cases (male 30, female 13) were observed between Apr. and Dec. 2003 when they were deployed in D.R.of Congo. Eliminating mosquito was used to decrease the density, including the usage of driving mosquito machine, killing mosquito lamp and chlorine cyanogens chrysanthemum ester, ”Prevent malaria-3”and COTECXIN as the precautionary medicines. Plasmodiums in blood were checked periodically. The cases with positive result of blood test and without clinical symptom was considered as infection, otherwise as disease with symptom appeared. Results The density of mosquito in house decreased. 3 cases (male 2, female 1) suffering from malaria, the incidence was 6.98%. Plasmodium was found in 39 individuals (male 26, female 13), the infection rate was 90.70%. The incidence was the lowest compared with contingents from other countries. Conclusion It was effective that these measures taken by reducing mosquito density and ”Prevent malaria-3”and COTECXIN usage in Chinese medical team during peacekeeping mission .

Objective To understand the current management situation of hand hygiene (HH)among health care workers(HCWs)in stomatology medical institutions in Zunyi,and provide basis for the scientific management of HH.Methods In October-December 2014,the on-site observation and questionnaire survey were adopted to investigate current management situation of HH in 127 stomatology medical institutions in Zunyi.Results The rates of qualified installation of sink,faucet,detergent,alcohol-based hand rub,and hand-drying facilities were 60.63%, 11 .02%,92.13%,22.05%,and 37.80% respectively.Except detergent and sink,the installation of other HH supplies in stomatology medical institutions in Zunyi were not ideal.The correct rate of HH among HCWs was 33.07%(42/127),qualified rates of HH methods among HCWs in departments of stomatology,comprehensive out-patient departments, stomatological clinics,and teeth-cleaning clinics were 50.00%,23.08%,23.53%,and 0 respectively.Conclusion HH facilities are not perfect in primary stomatology medical institutions in Zunyi,health ad-ministrative departments’supervision on HCWs’HH is inadequate,the awareness rate of HH knowledge and com-pliance to HH among HCWs are both low.

BACKGROUND: In the patients with congenital scoliosis, the spinal motor units exhibit developmental disorders and poor range of motion. It has been found that the compensation ability of coronal lumbosacral region (L4-S1) is associated with the occurrence of non-compensable trunk migration postoperatively.OBJECTIVE: To establish the three-dimensional finite element models of coronal lumbosacral region of normal and patients with congenital scoliosis and to compare the strain, displacement, stress and stiffness under different loading conditions among models.METHODS: One normal subject and two congenital scoliosis patients with different coronal lumbosacral region flexibility were selected, DICOM image datawere obtained by spiral CT scanning at the lumbosacral region, and then imported into MIMICS software, and a three-dimensional model was established according to the gray values of each tissue on CT,followed by simplified by GEOMAGIC, and finally imported into ABAQUS foftware to conduct a mechanic analysis under different loading conditions.RESULTS AND CONCLUSION: (1) Under different lateral forces, in the three models, the maximum stress mainly distributed on the frontal region of L4 cortical bone, and maximum displacement concentrated on L5. (2) There was no significant change in the stress distribution in the two scoliosis models, but the compensable model showed larger displacement change, and its stiffness was significantly less than that of the non-compensable model, indicating that the compensable model is easy to deform. (3) These findings suggest that three-dimensional finite element model is helpful to perform a biomechanical analysis for coronal lumbosacral region of congenital scoliosis, among which, a compensable model exhibits large displacement, suggesting a good flexibility.

BACKGROUND: Inherent modal analysis and harmonic response analysis on the human normal lumbosacral vertebraehave been reported, but there is a lack of comparative research on their modal analysis results before and after pediclescrew fixation.OBJECTIVE: To explore the dynamic characteristics of human lumbosacral vertebrae using three-dimensional finiteelement method.METHODS: Finite element model of lumbosacral vertebrae (L1-S1) before and after pedicle screw fixation was developedand validated based on CT images, and the modal analysis and harmonic response analysis were then conducted.RESULTS AND CONCLUSION: (1) Representative nodes were selected at the spinous process segments of L1, L3 andL5, and numbered as A, B, and C, respectively. (2) The maximum displacement of each node in Y and Z directions oflumbosacral vertebral model after internal fixation was significantly decreased compared with those of the normallumbosacral vertebral model, suggesting that screw fixation system plays a protective role in lumbosacral vertebrae, andreduces its amplitude under external load, thus diminishing its sensitivity to external load. (3) The lumbosacral vertebralmodal analysis can provide basis for further study on dynamic analysis, and the parameters such as natural frequency,modal shape and vibration amplitude of the lumbar spine have been determined.

Objective:To study the independent risk factors of tumor recurrence after radiofrequency ablation (RFA) in patients with hepatocellular carcinoma (HCC), and to establish a preoperative prediction score.Methods:A retrospective study was conducted on 168 HCC patients treated with RFA at Zhongshan Hospital affiliated to Sun Yat-sen University from June 2016 to September 2019. The X-tile software was used to determine the optimal cut-off value of preoperative circulating tumor cells (CTC) which was then used to analyze the relationship between different CTCs values with various clinical factors. The Cox regression model was used to analyze independent risk factors of recurrence after RFA, and each independent risk factor was assigned a score of 1 to compose the prediction score. The patients were divided into the low-risk group (0-2 scores), intermediate-risk group (3 scores) and high-risk group (4-5 scores). The Kaplan-Meier method was used to draw cumulative recurrence curves in calculating the cumulative recurrence rates of the 3 different groups.Results:Of 168 patients, there were 151 males and 17 females. Their age (Mean±SD) was 58.33±9.53 years. CTC≥1/3.2 ml was detected in 131 patients (77.98%) (range 0-20/3.2 ml). The X-tile software determined the preoperative CTC cut-off value of HCC patients to be 2/3.2ml which separated a CTC-negative group with 93 patients, and a positive group of 75 patients. On analyses, the relationship between preoperative CTC and various preoperative clinical parameters were related to number of tumor nodules, tumor maximum diameter and alpha-fetoprotein (AFP) levels ( P<0.05). Multivariate analysis showed that CTC positivity[ HR(95% CI): 1.990(1.332-2.974)], AFP>20 ng/ml[ HR(95% CI): 1.659(1.111-2.477)], PIVKA-II>40 mAU/ml[ HR(95% CI): 1.580 (1.022-2.443)], number of tumor nodules ≥2[ HR(95% CI): 1.568 (1.057-2.326)], and tumor diameter>30 mm[ HR (95% CI): 1.544 (1.007-2.369)] were independent risk factors of recurrence ( P<0.05) after RFA in HCC patients. The cumulative recurrence rates of patients at 6 months, 12 months, and 18 months were 14.9%, 35.6%, and 56.4% in the low-risk group, 38.9%, 70.5%, and 85.0% in the intermediate-risk group, and 64.5%, 84.5% and 100% in the high-risk group. The differences were significant ( P<0.05). Conclusion:Preoperative CTC positivity, AFP>20 ng/ml, PIVKA-II>40 mAU/ml, tumor nodules ≥2, and tumor diameter>30 mm were independent risk factors of recurrence after RFA in HCC patients. This preoperative predictive score could be used to guide clinical treatment strategies.

Objective:To explore the application value of detecting circulating tumor cells (CTC) before liver transplantation for predicting the recurrence and survival of hepatocellular carcinoma (HCC).Methods:From October 2015 to October 2019, 62 HCC patients at Affiliated Zhongshan Hospital were collected and analyzed by Cyttel method before liver transplantation. CTC was determined by X-tile software and Kaplan-Meier method for determining the optimal cutoff value of CTC before liver transplantation and the relationship between CTC and clinical factors was analyzed. Univariate and multivariate COX regression analyses were performed for determining the independent risk factors affecting the prognosis. Kaplan Meier method was employed for describing the survival curve of tumor-free survival and overall survival after transplantation.Results:The optimal preoperative critical value of CTC was 3.2 ml. CTC ≥3/3.2 mL was set as CTC positive group while CTC <3/3.2 mL CTC negative group. The positive/negative CTC before transplantation was significantly correlated with preoperative Alpha-fetoprotein(AFP) level, maximal tumor diameter, lymph node metastasis, liver transplantation criteria and degree of differentiation ( P<0.05). Univariate and multivariate COX regression models indicated that the number of preoperative CTC (HR: 1.262, 95%CI: 1.069-1.489, P=0.006) and microvascular invasion (HR: 2.657, 95%CI: 1.120-6.305, P=0.027) were independent risk factors for tumor-free survival after transplantation while microvascular invasion (HR: 3.738, 95%CI: 1.219-11.459, P=0.027) was the sole independent risk factor affecting the overall survival of HCC after transplantation. Statistically significant difference existed between preoperative CTC positive/negative and tumor recurrence or metastasis (no recurrence, intrahepatic recurrence, and distant metastasis)( χ2=7.790, P=0.020). The disease-free survival rates of 1/2/3-year CTC-negative/positive patients were 82.90%, 68.70%, 58.90% and 49.00%, 29.40%, 22.10%; the 1/2/3-year overall survival rates of preoperative CTC-negative/positive patients were 85.50%, 77.10%, 69.79% and 64.90%, 47.20%, 40.50% respectively. The disease-free survival curve of CTC-negative patients was significantly higher than that of CTC-positive counterparts ( P<0.001) and the overall survival curve of CTC-negative patients was significantly higher than that of CTC-positive counterparts ( P<0.005). Conclusions:Preoperative CTC detection has certain application value in evaluating the prognosis of liver cancer after liver transplantation, which has important clinical significance and application prospects.

Objective:To analyze the risk factors of hepatocellular carcinoma microvascular invasion (MVI) and to construct a preoperative prediction clinical scoring system.Methods:A retrospective analysis was made on 113 patients with hepatocellular carcinoma undergoing hepatectomy at Zhongshan Hospital from March 2018 to Jun 2019.Postoperative pathology confirmed 35 cases with microvascular invasion.Results:The multivariate logistic regression model showed that the maximum tumor diameter( OR: 1.028, 95% CI: 1.001-1.005), the smoothness of the capsule edge( OR: 0.208, 95% CI: 0.062-0.699), the positive circulating tumor cells (CTC)( OR: 3.728, 95% CI: 1.029-13.501) and abnormal prothrombin(PIVKA-Ⅱ)( OR: 1.001, 95% CI: 1.000-1.002) were risk factors for MVI. The area, sensitivity and specificity of the clinical score constructed by assigning 1 point to each risk factor were 0.906, 74.29% and 92.31%, respectively. Clinical scores of 0, 1, 2, 3, and 4 predict MVI positive rates of 0 (0/26), 9.09% (3/33), 28.57% (6/21), 77.78% (14/ 18), 85.71% (12/14). Conclusions:Tumor maximum diameter>62 mm, PIVKA-Ⅱ>115 mAU/ml, unsmooth tumor capsule and CTC in peripheral blood are independent high risk factors in patients with MVI.

Objective:To investigate the correlation between preoperative circulating tumor cells (CTC) and microvascular invasion (MVI) in patients with hepatocellular carcinoma.Methods:The data of 227 patients who underwent hepatocellular carcinoma resection in Zhongshan Hospital Affiliated to Sun Yat-sen University from January 2018 to March 2020 were retrospectively analyzed. The peripheral blood CTC was detected by Cyttel detection before operation. The relationship between preoperative peripheral blood CTC and clinical characteristics of patients was analyzed; the multivariate logistic regression model was used to analyze the independent risk factors for MVI; the receiver operating characteristic (ROC) curve was used to compare the efficacy of each independent risk factor in predicting the occurrence of MVI, and the relationship between CTC and MVI was clarified.Results:According to the ROC curve, the cut-off values for predicting MVI of CTC, alpha-fetoprotein (AFP), protein induced by vitamin K absence or antagonist Ⅱ (PIVKA-Ⅱ), and tumor long-axis diameter were 3 CTC/3.2 ml, 158 μg/L, 178 AU/L and 59 mm. CTC-positive group had ≥3 CTC/3.2 ml in peripheral blood, and CTC-negative group had <3 CTC/3.2 ml, and there were 117 and 110 cases in the two groups. The median AFP levels of preoperative CTC-positive group and CTC-negative group were 123.0 μg/L (0-20 000.0 μg/L) and 9.6 μg/L (0-18 676.0 μg/L), and the median tumor long-axis diameter was 50.0 mm (5.0-200.0 mm) and 36.0 mm (2.0-150.0 mm), the differences between the two groups were statistically significant (both P < 0.05). Before operation, AFP≥158 μg/L ( OR = 3.551, 95% CI 1.426-8.843, P = 0.006), PIVKA-Ⅱ≥178 AU/L ( OR = 12.250, 95% CI 4.384-34.231, P < 0.01), peripheral blood CTC ≥ 3 CTC/3.2 ml ( OR = 8.913, 95% CI 3.561-22.306, P < 0.01) and tumor long-axis diameter ≥59 mm ( OR = 3.250, 95% CI 1.339-7.885, P = 0.009) were independent risk factors for the occurrence of MVI; the area under the ROC curve (AUC) of these factors for predicting MVI was 0.752, 0.777, 0.857 and 0.743. CTC was more effective in predicting MVI than AFP and tumor long-axis diameter, and the differences were statistically significant (both P < 0.05). The efficacy of CTC in predicting MVI was slightly better than that of PIVKA-Ⅱ, but the difference was not statistically significant ( P > 0.05). Conclusion:CTC may be one of the important indicators of hepatocellular carcinoma MVI in clinical practice.

BACKGROUND: Implantation of bone marrow mesenchymal stem cells (BMSCs) is a potential alternative for promoting bone defects healing or osseointegration in osteoporosis. However, the reactive oxygen species (ROS) accumulated and excessive inflammation in the osteoporotic microenvironment could weaken the self-replication and multi-directional differentiation of transplanted BMSCs. METHODS: In this study, to improve the hostile microenvironment in osteoporosis, Poloxamer 407 and hyaluronic acid (HA) was crosslinked to synthetize a thermos-responsive and injectable hydrogel to load MnO2 nanoparticles as a protective carrier (MnO2 @Pol/HA hydrogel) for delivering BMSCs. RESULTS: The resulting MnO2 @Pol/HA hydrogel processed excellent biocompatibility and durable retention time, and can eliminate accumulated ROS effectively, thereby protecting BMSCs from ROS-mediated inhibition of cell viability, including survival, proliferation, and osteogenic differentiation. In osteoporotic bone defects, implanting of this BMSCs incorporated MnO2 @Pol/HA hydrogel significantly eliminated ROS level in bone marrow and bone tissue, induced macrophages polarization from M1 to M2 phenotype, decreased the expression of pro-inflammatory cytokines (e.g., TNFa, IL-1b, and IL-6) and osteogenic related factors (e.g., TGF-b and PDGF). CONCLUSION This hydrogel-based BMSCs protected delivery strategy indicated better bone repair effect than BMSCs delivering or MnO2 @Pol/HA hydrogel implantation singly, which providing a potential alternative strategy for enhancing osteoporotic bone defects healing.

Objective:To study the value hyperthermic intraperitoneal chemoperfusion after ruptured and hemorrhage of hepatocellular carcinoma.Methods:A retrospective study was conducted on 53 patients with ruptured hepatocellular carcinoma treated in Zhongshan Hospital Affiliated to Sun Yat-sen University from January 1, 2009 to January 1, 2019.Patients who underwent surgical resection combined with hyperthermic intraperitoneal chemoperfusion were included into the experimental group. Those who underwent surgical treatment only were included into the control group. The clinical data, postoperative hospital stay, complications, long-term tumor-free survival and overall survival were analyzed. Independent risk factors affecting prognosis were also determined.Results:Of the 33 patients in the experimental group, there were 27 males and 6 females, with a mean age ± s. d. being 50.49±11.59 years. There were 20 patients in the control group, including 17 males and 3 females, with a mean ± s. d. of 53.70±13.89 years. There were no significant differences in the length of postoperative hospital stay and complication rates between the two groups ( P>0.05). The tumor-free survival rate of the experimental group was significantly higher than that of the control group ( P<0.05). There was no significant difference in overall survival rates between the two groups ( P>0.05). Cox multivariate analysis showed that histological classification [ HR(95% CI): 27.700(1.695-452.794); 42.754(2.091-874.034)] and hyperthermic intraperitoneal chemoperfusion [ HR(95% CI): 0.238(0.086-0.661); 0.205(0.069-0.611)] were independent risk factors affecting tumor-free survival and overall survival (all P<0.05). Conclusion:Hyperthermic intraperitoneal chemoperfusion after surgical resection for ruptured hepatocellular carcinoma is a safe and effective treatment.