BACKGROUND: Gentamicin bead chain is an effective drug delivery system for treatment of osteomyelitis, but it cannot be degraded, need to be removed by second operation, and can breed pathogens. As a result, biodegradable drug delivery systems become a hotspot. Nano-hydroxyapatite/poly(β-hydroxybutyrate-co-β-hydroxyvalerate)-polyethylene glycol-gentamicin (nano-HA/PHBV-PEG-GM-DDS) is considered to be a good choice for the current predicament. OBJECTIVE: To evaluate the acute or chronic toxic reactions of the whole body and local tissues, intracutaneous stimulation, cytotoxicity and hemolytic reactions after bone remodeling and implantation of nano-HA/PHBV-PEG-GM-DDS, thus providing a new kind of material for treating osteomyelitis. METHODS: Plastic nano-HA/PHBV-PEG-GM-DDS was prepared using plastic fibrin glue as microsphere scaffold and nano-HA as the core carrier of GM that was coated with PHBV and PEG. The acute, subacute/chronic toxicity, implantation, hemolysis, cytotoxicity and intracutaneous stimulation tests were performed according to the evaluated criteria of medical implanted materials as wel as biological and animal trials recommended in GB/T16886.1-1997. RESULTS AND CONCLUSION: The plastic nano-HA/PHBV-PEG-GM-DDS was nontoxic and caused no apparent changes in liver and kidney function and serum biochemical indexes. Pathological examination showed that the implanted material was covered with tissues, and inflammation changes accorded with the general regularity of inflammatory outcomes. After implantation, the nano-HA/PHBV-PEG-GM-DDS was biodegraded and replaced by osseous tissues. The hemolytic rate of the material extract to the composite diffusion solution was 1.2%, which was below the standard criteria (5%). Human bone marrow cells cultured in vitro with the plastic nano-HA/PHBV-PEG-GM-DDS grew normally with good morphology. There was no stimulation reaction according to the criteria after the diffusion solution was subcutaneously injected into the back of the animal. These findings indicate that the plastic nano-HA/PHBV-PEG-GM-DDS for treating osteomyelitis possesses excel ent biocompatibility and security.

OBJECTIVE:To study the improvement effects of baicalein against myocardial ischemia/reperfusion(I/R)injury in rats. METHODS:I/R injury model was induced by Langendorff method. Isolated heart of 40 rats were randomly divided into nor-mal group(continuous perfusion),model group(perfusion withdrawal 20 min)and baicalein high,medium and low concentration groups (K-H solution of baicalein 40,10 and 2.5 μmol/ml 10 min before perfusion withdrawal). The myocardial infarction rate, the activity of creatine kinase(CK)and lactate dehydrogenase(LDH)in coronary effluent liquid,SOD activity and MDA content, GSH/GSSG and apoptosis rate of cardiac muscle cell in myocardial tissue were detected. RESULTS:Compared with normal group, the myocardial infarction rate,apoptosis rate of cardiac muscle cell,the activities of CK and LDH and the content of MDA in myo-cardial tissue were increased in model group,while SOD activity and GSH/GSSG of myocardial tissue decreased(P<0.01). Com-pared with model group,the isolated myocardial infarction rate and the activities of CK and LDH in baicalein low and medium con-centration groups decreased,while SOD activity increased(P<0.05 or P<0.01);apoptosis rate of cardiac muscle cell and the con-tent MDA of myocardial tissue decreased significantly in medium concentration group,while GSH/GSSG increased (P<0.05 or P<0.01);those indicators had no significant change in high concentration group(P>0.05). CONCLUSIONS:Baicalein has cer-tain improvement effect on myocardial I/R injury in rats,and its mechanism may be associated with antioxidant and anti-apoptosis effect of baicalein.

Objective To evaluate the safety and efficacy of self-expanding metallic stents (SEMS) in one-stage surgery for patients with left-sided malignant colorectal obstruction. Methods The clinical data of 97 patients with left-sided colorectal cancer who had been admitted to the First Affiliated Hospital of Zhejiang Chinese Medical University from May 2005 to September 2008 were retrospectively analyzed. Forty-six patients with left-sided malignant colorectal obstruction were in the test group, after the placement of SEMS, they received one-stage resection and anastomosis; 51 patients with left-sided colorectal cancer (without obstruction) were in the control group, and they received one-stage surgery. The defecation and anal exhaust time, hospital stay and incidence of postoperative complications between the 2 groups were analyzed. All data were analyzed via t test or chi-square test. Results One patient in test group had acute diffuse peritonitis which was induced by intestinal perforation at postoperative day 4, and was treated with radical resection for sigmoid cancer. One-stage surgery was successfully performed on 45 patients, and they were discharged at postoperative day 11-16. One patient died of respiratory infection and heart failure at postoperative day 10. All patients were followed up for 4-48 months. There was no significant difference in defecation and anal exhaust time, hospital stay, incidence of perioperative complications, recurrence, metastasis and survival within follow-up interval between the 2 groups (t=0.164, 1.358, χ~2 = 0.252, 1.200, 0.580, P >0.05). Conclusion SEMS is effective and safe in the treatment of left-sided malignant colorectal obstruction.

Objective To compare the tumor sizes of primary lesions in pancreatic cancer based on CT scan and postoperative pathological analysis and measure the extent of filtration under a microscope,and to determine the CTV in radiotherapy target delineation.Methods A total of 19 patients with pancreatic cancer who were admitted to PLA General Hospital and Air Force General Hospital,PLA from 2013 to 2014 were analyzed.In 15 patients,the maximum diameters of tumor cross-section were measured based on the images of preoperative multi-slice spiral CT and postoperative gross samples,respectively.In 19 patients,the extent of tumor infiltration was measured on pathological sections under a microscope and the actual extent of infiltration was calculated.The paired t-test was applied to analyze the differences in the results of different measurement methods.Results In the 15 patients,the maximum tumor diameters measured with gross samples and CT scan were 33.6 mm and 30.1 mm,respectively (P=0.000),and the median and mean of the differences were 3.1 mm (1.2-8.0 mm) and 3.6±2.0 mm,respectively (95％ CI 1.2-6.0).In the 19 patients,the maximum actual infiltration distance and the maximum distance measured were 3.50 mm and 3.19 mm,respectively (P=0.000),and the median and mean of the differences were 0.31 mm (0.15-0.50 mm) and 0.30±0.09 mm,respectively.The maximum distance between the margin of primary lesions and the infiltrating lesions was 5.21 mm,with a median of 3.34 mm (2.19-5.21 mm) and a mean of 3.50± 0.88 mm (95％ CI 2.19-5.06).Conclusions Contrast-enhanced CT scan underestimates the actual size of primary lesions in pancreatic cancer,and an extension of 5 mm outside gross tumor volume (GTV) as CTV may not be sufficient.It is recommended to extend another 1-3 mm outside GTV as CTV.

Aim To investigate the protective effects of dihydroquercetin(DDQ) against myocardial ischemis reperfusion injury(MIRI) in rats.Methods Male Sprague-Dawley rats were randomly divided into 4 groups(n=10):normal,control,I/R model, and I/R model+DDQ(5,10 mg·L-1).This study used an isolated Langendorff rat heart model.The left ventricu-lar developed pressure(LVDP),heart rate(HR) and the maximum rise and fall rate of the left ventricular pressure(±dp/dtmax) were monitored and documented using a physiological recorder.The levels of lactate dehydrogenase(LDH) and creatine kinase(CK) were analyzed using enzyme-linked immunosorbent assay(ELISA).Infarct size was measured using 2,3,5-triphenyltetrazolium chloride staining.The levels of superoxide dismutase(SOD) and malondialdehyde(MDA), as well as the ratio of glutathione/glutathione disulfide(GSH/GSSG) were measured via ELISA.HE staining was used to observe the pathological changes of myocardial tissue.Results Compared with the I/R model group, the I/R model+DDQ groups raised hemodynamic parameters, SOD level, and GSH/GSSG ratio;and reduced the amount of CK, LDH, MDA levels.Moreover, the I/R model+DDQ groups had lower infarct size and pathological changes in myocardial tissue than I/R model group.Conclusion DDQ exertes cardioprotective effects against I/R via improving the oxygen free radical scavenging ability, the inhibition of oxygen free radical and reducing lipid peroxidation.

To explore the differentiation of gastrointestinal stromal tumor(GIST) with synchronous carcinoma clinical and pathological features,diagnosis and differential diagnosis.Methods Clinical characteristics,pathological morphology and immunohistochemical staining were observed in 9 cases of GIST with synchronous carcinoma,with review of the relevant literature.Results Microscopically,in 4 cases GIST with esophageal carcinoma,most of tumor cells in central focus were squamous cells and keratin pearls which were well differentiated and the rest of tumor cells are basal like cells on the edge.In the other 5 cases (4 of them with gastric carcinoma and 1 with rectal cancer).Microscopically,the tumors were composed of dysplastic glands which presented as adenoid structures and poorly differentiated.The majority of gastric GIST were spindle cell tumors,which resembled smooth muscle tumors histologically and showed a variety of histological pattern,such as lace like pattern,palisading pattern,antique coins like pattern and eddy pattern.And a perinuclear vacuolization pattern was common.Immunohistochemistry showed that the tumor cells were positive for CK5/6,CK14 and p53,but negative for S-100,CK7 of the 4 cases GIST with esophageal carcinoma.In the other 5 cases (4 of them with gastric carcinoma and 1 with colorectal cancer),showed that CK7,CK20,CEA and HER-2 were positive and negative for S-100.In all the 9 case of GIST,the tumor cells were positive for CD34,CD117 (+),DOG1 and SMA,but negative for S-100,desmin,etc.Conclusion There are no special clinical symptoms in most of GIST with synchronous carcinoma,because these GISTs are generally incidental findings.The proliferative index of GIST with synchronous carcinoma is observably lower than that of GIST without synchronous carcinoma.Most GISTs with synchronous carcinoma can be treated by the standard treatment for the accompanying carcinoma,and do not need specific additional treatments.

Objective To investigate the expression and clinical significance of S100A14 and LOXL2 in papillary thyroid carcinoma tissues. Methods Paraffin blocks from 90 cases of thyroid lesion were collected to make tissue microarray. The expression of S100A14 and LOXL2 in 30 cases of nodular goiter (NG), 30 cases of classic papillary thyroid carcinoma (CPTC) and 30 cases of high invasion papillary thyroid carcinoma were detected by immunohistochemistry. The correlation of S100A14 and LOXL2 expression with the clinicopathological characteristics of papillary thyroid carcinoma patients was investigated. Results S100A4 and LOXL2 were highly expressed in papillary thyroid carcinoma. There was a gradually increasing trend from the expression in NG group, CPTC group to high invasive group. The positive rate of S100A14 in papillary thyroid carcinoma with lymph node metastasis was higher than that without lymph node metastasis (P < 0.05). There was significant difference of S100A14 and LOXL2 expression between CPTC group and high invasion group (P < 0.05). S100A14 expression was positively correlated with LOXL2 expression (r=0.332). Conclusion The high expression of S100A14 and LOXL2 may be related to the malignant biological behavior and invasiveness of papillary thyroid carcinoma, and S100A14 may promote lymph node metastasis.

Objective:To identify the current situation of contract signing for family physician services in Luohu District, Shenzhen, and to explore the associated factors with contract signing and access to services.Methods:Using the WeChat official account of"People′s Hospital of Luohu", an online survey was conducted to investigate the status of family physician′s contract services for residents in Luohu District from May 19th to 25th, 2019. A total of 14 487 valid responses were received. Chi-square test and Logistic regression models were used to analyze the contract signing of family physician services and the related factors.Results:8 560 (59.09%) of the participants had signed with a family physician, and 12 696 of them had learnt about the service before. The awareness rate of family doctor services was 87.64%. The contract signing rate of those unemployed, who living or working in Luohu less than 5 years, who living alone, having no Shenzhen medical insurance, or having not heard of family physicians signing services were less than 50%. The signing rate was positively correlated with the awareness of family physician contract service, as well as the possibility of accepting signed medical examination, traditional Chinese medicine services and health information. Only 9.70% of the contractors received health services information.Conclusions:The contract Signing rates and awareness rate of family physicians among young and middle-aged residents in Luohu District are relatively high. However, access to contract services varies considerably. The signing rate and accepted services are mainly affected by job, length of residence in Shenzhen, type of medical insurance, and understanding of contract.

Objective: The serotype screening of Shigella flexneri from 1934 to 1965 preserved by the National Center for Medical Culture Collections was carried out, and the molecular characteristics of the serotype conversion strains were studied. Methods: Serotyping of Shigella flexneri in this study was conducted by slide agglutination and multiplex PCR, respectively. The gtrⅡ gene sequence alignment and pulsed field gel electrophoresis typing were performed on the serotype conversion strains. Results: Among the 255 strains of Shigella flexneri preserved in CMCC (B) from 1934 to 1965, 79 were carrying gtrⅡ gene, of which 19 strains and 1 strain were agglutinated with the Y serotype and X serotype, respectively, and furthermore, the multiplex PCR assays results showed serotypes 2a and 2b, respectively, and the strains were considered to have serotype conversion. The 20 strains carrying the gtrⅡ gene showed multiple nucleotide mutations. Besides 3 strains of 3 amino acid mutations, the amino acid sequences of the other 17 strains showed a stop codon in advance, resulting in functional inactivation of gtrⅡ. PFGE analysis revealed that the similarity between the serotype Y strain carrying the gtrⅡ gene and the serotype 2a strain was 75.8%-100%, and the similarity between the serotype X strain carrying the gtrⅡ gene and the serotype 2b strain was 81.6%-100%. Conclusion Mutations in the gtrⅡ gene are more complicated in serotype-transforming Shigella flexneri serotype Y or X strains. Molecular typing suggests that the serotype-transforming Shigella flexneri serotype Y or X strains may be derived from the Shigella flexneri serotype 2a or 2b, and advance the serotype conversion to 1949.