BACKGROUND: Sampling the autogenous bone always needs to develop the second operational area or harvest surrounding the implant, which will increase the risk of trauma and infection. Therefore autogenous bone powder may be taken into consideration to reclaim and use for the treatment of local bone defect.OBJECTIVE: To construct experimental models of repairing bone defect by autogenous bone powder and implant material, and observe the biocompatibility between materials and host.DESIGN: Single sample observation.SETTING: College of Stomatology, Dalian Medical University.MATERIALS: The experiment was performed at the Animal Experimental Center of Dalian Medical University from August 2005 to April 2006. Five healthy hybrid dogs were used in this study. Titanium nail and Bio-Oss bone implant materials were designed and produced by Xi'an Zhonghang Titanium Biological Materials Co., Ltd.METHODS: The first, second and third premolars of dogs were uprooted and received implantation 3 months later. Four implant sockets were prepared at left and right sides respectively of each dog, totally 40 sockets. One titanium nail was implanted into each socket, totally 40 nails. Autogenous bone powder collected when drilling hole, Bio-Oss implant materials and their mixture at 1:1 were implanted in artificial bone defect at bucca side, respectively, while non-implanted bone was served as blank control.MAIN OUTCOME MEASURES: ①At week 9, recovery of bone mass was recorded. Height of alveolar bone, density of bone trabecula and osseointegration were observed by X-ray film.②Histological change was determined by methylene blue-basic fuchsin method.RESULTS: No titanium nail fell off, so five dogs were all involved in the result analysis.①General condition and bone defect: At week 9 of implantation, wound was well healed, and the titanium nail was stable with total reserved rate of 100%. Compared with blank control, the bone defect mass was less in bones implanted with autogenous bone powder (P＜0.01), and the least in bones implanted with mixed powder, which had optimal recovery.②Recovery of bone mass: X-ray film demonstrated that, 40 titanium nails were closely connected with bone, and the healing was well.③Biocompatibility between materials and host: All titanium nails were closely surrounded by erythroic compact bone, no blue soft tissues were seen between implant materials and bone, and direct bone interface appeared under low power lens.CONCLUSION: It is effective to repair bone defect by autogenous bone powder and implant material in dog models,good hiocompatibility is observed between materials and host.

site C. As for the pulmonary function indexes, site A

OBJECTIVE To investigate pathogenic bacteria isolated from children with respiratory tract infection and bacterial resistance to commonly used antimicrcrobial agents. METHODS Routine methods were used to isolate and identify fastidious bacteria and Streptococcus from children throat swabs. The drug susceptibility tests were performed by Kirby-Bauer method. RESULTS One hundred and twenty four pathogenic bacteria were isolated from 300 samples. The isolation rate was 41.3% and the fastidious bacteria were 78 strains(62.9%). The resistant rate of Haemophilus influenzae to clarithromycimn, trimethoprim-sulfamethoxazoe(SXT) and ampicllin was 70.0%, 60.0%and 66.7%, respectively. The resistant rate of Streptococcus pneumoniae to tetracycline, clindamycin, SXT and azithromycin was 96.2% 92.3% 92.3% and 92.3%, respectively; the resistant rate of Streptococcus pyogenes to tetracycline, clidamycin and azithromyoin was 100.00%, 94.45% and 83.33%, respectively. CONCLUSIONS Fastidion bacteria and S. pyogenes are the main Pathogenic bacteria in children with respiratory tract infection. The antimicrobial agents should be chosen according to antimicrobial sasceptibility test results.

Objective To investigate the effects of different concentrations of sevoflurane on proliferation and invasion in human prostate cancer PC3 cell line. Methods The cells were randomly divided into four groups:control group and three sevoflurane groups (exposed to 1.7%, 3.4%and 5.1%sevollurane for 2, 4 and 6 h respectively). The ability of prolifera-tion and invasion of PC3 cells were evaluated by MTT and Transwell invasion assays. Western blot analysis was performed to detect the protein expression of hypoxia inducing factor 1 alpha (HIF-1α) in PC3 cells. Results The ability of proliferation and invasion of PC3 cells was significantly increased after being exposed to sevollurane for 2, 4 and 6 h (P<0.05), and the expression of HIF-1αprotein in PC3 cells was significantly higher after being exposed to sevollurane for 2,4 and 6 h (P<0.05), showing the Treat 3 group>Treat 2 group>Treat 1 group (P<0.05). Conclusion Sevoflurane can promote prolifer-ation and invasion in PC3 cells, which are gradually increased with time and concentration of sevoflurane treatment. The mechanism may involve in the up-regulation of HIF-1αexpression.

AIM: To investigate the signaling mechanisms involved in the priming effects of lipopolysaccharide(LPS) on heat killed Staphylococcus aureus(HKSa)-induced nitric oxide(NO) production in macrophages.METHODS: Murine macrophage RAW264.7 was used in the experiment.Griess reagent was used to measure the content of nitrite in culture medium.Real-time PCR and Western blot was utilized to examine the mRNA and protein levels of toll-like receptor 2(TLR2),respectively.Dual luciferase reporter assay was used to assess the transcriptional activity of nuclear factor of activated T cells(NF-AT).RESULTS: The RAW264.7 cells pretreated with LPS for 24 h significantly enhanced NO production induced by HKSa,suggesting that LPS primed the macrophages and increased the reactivity of the cells to HKSa.LPS increased the mRNA and protein levels of TLR2 in a dose-dependent manner in RAW264.7 cells.The RAW264.7 cells pretreated with LPS enhanced NO production induced by peptidoglycan,one of the specific ligand of TLR2.The priming effect of LPS on HKSa-induced NO production was partly blocked by TLR2 neutralizing antibody.LPS significantly enhanced the transcriptional activity of NF-AT,which was inhibited by BAPTA/AM(a cell-permeable cytosolic calcium chelator) and cyclosporine A(CsA,an inhibitor for calcineurin).Both BAPTA/AM and CsA inhibited the priming effect of LPS on HKSa-induced NO production in RAW264.7 cells.CONCLUSION: The present study confirms the priming effect of LPS on the reactivity of RAW264.7 cells to HKSa.Pattern recognition receptor TLR2 and calcium/calcineurin/NF-AT signaling pathway may be involved in the priming process initiated by LPS.

Objective To investigate the efficacy and safety of preoperative regional intra-arterial chemoembolization combined with systemic vein chemotherapy in the treatment of locally advanced gastric cancer.Methods The clinical data of 78 locally advanced gastric cancer patients treated by radical D2 gastretomy from January 2010 to December 2012 were retrospectively analyzed.Patients were devided into treatment group receiving regional intra-arterial chemoembolization combined with systemic vein chemotherapy (n =36),and those with preoperative systemic vein chemotherapy (n =42) 3 to 4 weeks before surgery.Systemic chemotherapy with mFOLFOX6 was started after 5 weeks of surgery in the two groups.Results The incidence of toxicity reaction and postoperative anastomotic leakage were lower in treatment group than in control group,all P ＜ 0.05.The 1-year recurrence and overall survival rate were similar between the two groups (all P ＞ 0.05).The 3-year liver metastasis rate was higher in treatment group than in control group (x2 =4.063,P ＜ 0.05).The 3-year survival rate was higher than that of the control group(x2 =4.396,P ＜ 0.05).Conclusions Preoperative systemic vein chemotherapy combined with regional intra-arterial chemoembolization decreases toxicity reaction,anastomotic leakage and liver metastasis,while prolonging 3-year overall survival.

Objective:To investigate the predictive value of neuron-specific enolase (NSE), serum 100 calcium-binding protein β (S100β), gray-white-matter-ratio on head CT (GWR) and the combination of the three on the prognosis of neurological function in patients with post-cardiac arrest brain injury (PCABI).Methods:A total of 136 patients admitted to Tianjin Medical University General Hospital after resuscitation from cardiac arrest from September 2021 to May 2023 were selected and included in the good prognosis group (96 patients) and the poor prognosis group (40 patients) based on the Glasgow-Pittsburgh Cerebral Performance (CPC) classification at discharge, respectively, to compare the demographic data, resuscitation data and NSE, S100β and GWR levels within 24 h of admission between the 2 groups, and modified Poisson regression was applied to investigate the factors affecting the neuroprognosis of PCABI patients. The effectiveness of NSE, S100β, GWR and the combination of the three in predicting neurological prognosis was evaluated using receiver operating characteristic (ROC) curve and the area under the curve (AUC), and the statistical differences in AUC were compared by Delong's test.Results:NSE, S100β, GWR, history of coronary artery disease, APACHEⅡ score, time from CA to CPR, duration of resuscitation, and dose of epinephrine use were independent factors influencing the neurological prognosis of PCABI patients ( P<0.05). Compared with the good prognosis group, NSE and S100β levels were significantly higher and GWR levels were significantly lower in the poor prognosis group, with statistically significant differences ( P<0.01). The AUCs for NSE, S100β and GWR to predict poor neurological prognosis were 0.905(0.851, 0.959), 0.876 (0.797, 0.956), 0.842(0.754, 0.930), with cut-off values of 26.75 ng/mL, 1.35 ng/mL and 1.195, respectively, and an AUC of 0.982 (0.961, 1.000) for the combination of the three predicting poor neurological prognosis, significantly higher than any single indicator ( P=0.001 4, 0.001 6, 0.002 8). Conclusions:Early monitoring of NSE, S100β and GWR is effective in predicting the neurological prognosis of PCABI patients at discharge, and the combination of all three significantly improves the predictive power.

Objective:To construct an early prediction model for post cardiopulmonary resuscitation-acute kidney injury (PCPR-AKI) by machine learning and provide a basis for early identification of acute kidney injury (AKI) high-risk patients and accurate treatment.Methods:It was a single-center retrospective study. The clinical data of patients admitted to Tianjin Medical University General Hospital after cardiopulmonary resuscitation following cardiac arrest from January 1, 2016 to October 31, 2023 were collected. The end-point event of the study was defined as AKI occurring within 48 hours after cardiopulmonary resuscitation. The patients were divided into AKI group and non-AKI group according to the AKI diagnostic criteria, and the differences of baseline clinical data between the two groups were compared. The patients who met the inclusion criteria were randomly (using the train_test_split function, set the random seeds to 1, 2, and 3) divided into training and validation sets at a ratio of 7∶3. Random forest (RF), support vector machine, decision tree, extreme gradient boosting and light gradient boosting machine algorithm were used to develop the early prediction model of PCPR-AKI. The receiver-operating characteristic curve and decision curve analysis were used to evaluate the performance and clinical practicality of the predictive models, and the importance of variables in the optimal model was screened and ranked.Results:A total of 547 patients were enrolled, with age of 66 (59, 70) years old and 282 males (51.6%). There were 238 patients (43.5%) having incidence of AKI within 48 hours after cardiopulmonary resuscitation. In the AKI group, 182 patients (76.5%) were in stage 1, 47 patients (19.7%) were in stage 2, and 9 patients (3.8%) were in stage 3. There were statistically significant differences in the age, time to reach resuscitation of spontaneous circulation, time from cardiac arrest to starting cardiopulmonary resuscitation, proportion of initial defibrillation rhythm, proportion of electric defibrillation, proportion of mechanical ventilation, adrenaline dosage, sodium bicarbonate dosage, proportion of coronary heart disease, proportion of hypertension, proportion of diabetes, serum creatinine, blood urea nitrogen, blood lactic acid, blood potassium, brain natriuretic peptide, troponin, D-dimer, neuron specific enolase, and 24 hours urine volume after cardiopulmonary resuscitation between AKI group and non-AKI group (all P<0.05). Among the five machine learning algorithms, RF model achieved the best performance and clinical practicality, with area under the curve of 0.875, sensitivity of 0.863, specificity of 0.956, and accuracy rate of 90.7%. In the variable importance ranking of RF model, the top 10 variables were as follows: time to reach resuscitation of spontaneous circulation, time from cardiac arrest to starting cardiopulmonary resuscitation, initial defibrillable rhythm, serum creatinine, mechanical ventilation, blood lactate acid, adrenaline dosage, brain natriuretic peptide, D-dimer and age. Conclusions:An early predictive model for PCPR-AKI is successfully constructed based on machine learning. RF model has the best predictive performance. According to the importance of the variables, it can provide clinical strategies for early identification and precise intervention for PCPR-AKI.

Cystatin, a cysteine protease inhibitor found in many parasites, plays important roles in immune evasion. This study analyzed the molecular characteristics of a cystatin from Fasciola hepatica (FhCystatin) and expressed recombinant FhCystatin (rFhcystatin) to investigate the immune modulatory effects on lipopolysaccharide-induced proliferation, migration, cytokine secretion, nitric oxide (NO) production, and apoptosis in mouse macrophages. The FhCystatin gene encoded 116 amino acids and contained a conserved cystatin-like domain. rFhCystatin significantly inhibited the activity of cathepsin B. rFhCystatin bound to the surface of mouse RAW264.7 cells, significantly inhibited cell proliferation and promoted apoptosis. Moreover, rFhCystatin inhibited the expression of cellular nitric oxide, interleukin-6, and tumor necrosis factor-α, and promoted the expression of transforming growth factor-β and interleukin-10. These results showed that FhCystatin played an important role in regulating the activity of mouse macrophages. Our findings provide new insights into mechanisms underlying the immune evasion and contribute to the exploration of potential targets for the development of new drug to control F. hepatica infection.

Objective:To understand the incidence of HIV infection, high risk behaviors and pre-exposure prophylaxis/post-exposure prophylaxis (PrEP/PEP) utilization in men who have sex with men (MSM) in Beijing.Methods:Sample size was estimated to be 1 227 persons and 207 person year respectively in the survey and the cohort by using Epi Info 7.0 software. Using convenient sampling method, MSM were recruited by using Wechat app. Questionnaire was completed online to collect the information about demographic characteristics, high risk behavior, and utilization of PrEP/PEP of the MSM. MSM collected dry blood spot (DBS) samples by themselves, and mailed the DBS samples to laboratory for HIV nucleic acid testing. Open cohort was established and those with HIV negative nucleic acid testing results were followed up. Non-conditional binary logistic regression method was used to identify the associated factors for high risk anal sex in the last month and having multiple homosexual partners in the last month.Results:A total of 1 147 MSM were recruited, and follow up for 236 person years was conducted in 956 MSM with negative HIV nucleic acid testing results. The detection rate of new HIV infection was 1.3 per 100 person-years (3/236). During the last month, the proportions of consistent condom use in anal sex and oral sex were 50.7% (238/469) and 4.9% (23/469). In the MSM, 5.9% (43/723) had sex with HIV positive partners in the last month. 9.8% (103/1 049) used PrEP, and 8.7% (91/1 049) used PEP. The proportion of consistent condom use in PrEP and PEP were 34.3% (24/70) and 72.2% (39/54) respectively. Logistic regression analysis revealed that compared with those who used no PrEP/PEP, those who used PrEP/PEP were more likely to have unprotected anal sex in the last month (a OR=3.16, 95% CI:1.45-7.18), and more likely to have multiple homosexual partners in the last month (a OR=2.64, 95% CI:1.19-6.30), and compared with those who used no Rush Popper or drugs in the last month, those who used Rush Popper or drugs in the last month were more likely to have unprotected anal sex in the last month (a OR=2.34, 95% CI:1.67-3.30), and more likely to have multiple homosexual partners (a OR=2.42,95% CI:1.76-3.33). Conclusions:It is necessary to strengthen the health education to promote condom use and introduce the harm of drug use in MSM. In PrEP and PEP services, it is still necessary to suggest consistent condom use for MSM.