BACKGROUND: For decades, liposome drug carrier has been used to enhance drug stability and efficacy, reduce drug toxicity and adverse effects. However, they fail to provide long-term delivery due to insufficient stability. Studies have demonstrated that silica is not toxic, with chemically inert and biological compatibility, and can be used as modified material. OBJECTIVE: To characterize the silica coated liposome and investigate the controlled release property. DESIGN, TIME AND SETTING: In vitro observation. The study was performed at the Nanomedicine and Biosensor Laboratory, Biomedical Engineering Center, Harbin Institute of Technology from May 2007 to June 2008. MATERIALS: Dipalmitoylphosphatidylcholine (DPPC) was purchased from Nanjing Kangsente Chemical Engineering Company; tetraethylorthosilicate (TEOS) was purchased from Aldrich, USA. Doxorubicin (DOX) was purchased from Beijing Huafeng United Technology Company; Sephadex G-50 was purchased from Amersham Biosciences, Sweden. All other chemical agents were of analytical purity. METHODS: Liposome was formed from DPPC following the precipitation of silica by sol-gel method. MAIN OUTCOME MEASURES: Zeta-potential and dynamic light scanning were used for zeta-potential measurement and particle size distribution; transmission electron microscopy was used to collect the image of particle morphology; Fourier transform infrared spectroscopy (FTIR) was used to display chemical characteristics of Si-O-Si structure; Spectrophotofluorimetry was used to determine DOX regression equation and was further used for calculation in drug encapsulation efficiency and in vitro release.　RESULTS: ①Silica coated liposome was successfully prepared. ②FTIR proofed the presence of Si-O-Si at 1 166, 1 080, 859 and 526 cm-1. ③The DOX encapsulated silica coated liposome had encapsulation efficiency of 72.4%. ④Drug release profiles showed that sustained release of DOX was achieved after modification of silica on liposome. CONCLUSION: With Si-O-Si as protective layer, the liposome has increased stability and prolonged drug release.

Objective To evaluate the effect of dexmedetomidine on the quality of recovery from sevoflurane-based anesthesia in the patients undergoing abdominal surgery.Methods Eighty patients of both sexes, aged 30-64 yr, weighing 45-80 kg, with American Society of Anesthesiologists physical status Ⅰ or Ⅱ , scheduled for elective abdominal surgery, were randomly assigned into 2 groups (n =40 each) using a random number table: control group (group C) and dexmedetomidine group (group D).After routine induction of anesthesia, all the patients were tracheally intubated, and mechanically ventilated.Anesthesia was maintained with sevoflurane inhalation and intermittent iv boluses of sufentanil and cisatracurium besylate, and bispectral index values were maintained at 45-60.After induction of anesthesia, dexmedetomidine was infused in a dose of 1 μg/kg over 15 min, followed by a continuous infusion of 0.6 μg · kg-1 · h-1 until 30 min before the end of surgery in group D.Group C received normal saline instead.Heart rate (HR) and mean arterial pressure (MAP) were recorded at the end of surgery, and at 1 min before and after extubation.The emergence time, extubation time, and occurrence of bucking during extubation, and nausea and vomiting, respiratory depression, and agitation during recovery from anesthesia were recorded.Results Compared with group C, MAP and HR were significantly decreased at 1 min before and after extubation, the emergence time and extubation time were shortened, the incidence of bucking, nausea and vomiting, and agitation was decreased, and no significant change was found in the incidence of respiratory depression in group D.Conclusion Dexmedetomidine infused in a dose of 1 μg/kg after routine induction of anesthesia, followed by a continuous infusion of 0.6 μg · kg-1 · h-1 until 30 min before the end of surgery, can significantly increase the quality of recovery from sevoflurane-based anesthesia in the patients undergoing abdominal surgery.

The scenario simulation teaching method created a novel teaching mode for medical ethics and explored the new methods to enhance the teaching level.Through 6-year practice teaching,the authors made a comprehensive summary,refined the process,and resolved the existing problems.Several experiences gained in the process.The form of scenario simulation is novel,which is loved by the students.It is helpful to achieve the teaching goal that class should be led by students,cultivate medical students' humanistic quality,and make teaching benefits teachers as well as students.

Objective:To explore the relation between parental cohesion,peer acceptance and the loneliness of left-behind children,and furthermore explore the mediation role of self-esteem.Methods:Totally 427 left-behind children in Hubei Province (275 males,152 females) were surveyed,and the Parental Cohesion Scale (PCS),Peer Nomination (PN),Self-Esteem Scale (SES) and Children Loneliness Scale (CLS) were used to assess parental cohesion,peer acceptance,self-esteem and loneliness respectively.The relation between parental cohesion,peer acceptance andthe loneliness of left-behind children,and the mediation role of self-esteem wereanalyzed.Results:The CLS scores in left-behind children were negatively correlated with the scores of PCS,PN,and SES (r =-0.31,-0.37,-0.50,P ＜ 0.01),the SES scoresplayed a mediation role in the relation between PN scores and CLS scores (95 ％ CI:-7.02--0.01),and between PCS scores and CLS scores (95 ％ CI:-0.18--0.09).Furthermore,the unique effect of the PN scores on the CLS scores (sr2 =0.10) was higher than that of PCS scores (sr2 =0.06).Conclusion:The current research indicates that the loneliness,parental cohesion,peer acceptance and self-esteem of the left behind children have a close relationship.Furthermore,it suggests that self-esteem may play partial mediating effects between parental cohesion,peer acceptance and the loneliness of left-behind children.

Objective:To explore the relationship between hepatitis B virus (HBV) infection and the pathogenesis of multiple my-eloma (MM), in order to provide an epidemiological evidence for the prevention and treatment of MM. Methods:Clinical and epidemi-ological data of 185 MM patients and 182 non-tumorous patients were collected. Subjects were randomly selected from in-patients who were homeochronously admitted to the same five grade-III A hospitals, including Xi'an Central Hospital, Shaanxi People's Hospital, Xi'an Jiaotong University Xibei Hospital, and so on. MM patients were selected in terms of age and gender. Peripheral blood HBsAg was assayed by ELISA. If HBsAg was negative, the S and C-gene fragments of HBV DNA were tested using nested PCR . Fisher's ex-act test orχ2 test (SPSS statistical software) was used to compare the differences between the groups. Logistic regression was employed to examine the association between the pathogenesis of MM and HBV infection. Results:In MM patients, the HBsAg positive rate was 8.11% (15/185), the occult HBV infection (OBI) positive rate was 3.53% (6/170), and the total HBV infection rate was 11.35% (21/185). For the control group, the HBsAg positive rate was 4.40%(8/182), the OBI positive rate was 0.57%(1/174), and the total HBV in-fection rate was 4.95%(9/182). No statistical difference in HBsAg or OBI positive rate was found between the two groups (P>0.05). However, MM patients showed significantly higher total HBV infection rate than that of the controls [χ2=5.02, P<0.05;OR was 2.46 (95%CI:1.10-5.53, P<0.05)]. Additionally, the proportion of ISS stage III was significantly higher in MM patients with HBV infection than in uninfected MM patients (85.71%vs. 60.37%,χ2=5.15, P<0.05). Patients with HBV infection showed reduced albumin level (χ2=5.60, P<0.05) and aκ/λlight chain ratio (P<0.05) compared with uninfected patients. Conclusion:The risk of MM pathogenesis after HBV infection is significantly increased as OBI is included in the analyses. Furthermore, MM patients with HBV infection will develop more severe liver damage, indicating that OBI in MM patients with negative HBsAg should be screened before chemotherapy to pre-vent HBV reactivation.

Objective To evaluate the outcomes of the payment reform at public hospitals in Sanming city.Methods Interrupted time series analysis was used to compare changes of the average days of stay,per capita hospitalization expense,outpatient expense per visit,proportion of medical expense and that of drugs during hospitalization at 21 public hospitals at or above county level before and after the DRGs reform.Results Comparisons before and after the reform found the average days of stay at the original momentum,poor control in curbing the proportion of medical expense and that of drugs during hospitalization,adropping followed by rising trend in the outpatient expense per visit,and minimal drop of the abovementioned proportions.Conclusions The rapid growth of outpatient and hospitalization costs at tertiary hospitals may be incurred by unreasonable cost transfer,structural trend of hospitalization expense makeup,and rationality pending scrutiny.

Tripartite-sector reform (a synergistic reform in public health services,medical insurance and medicine production-circulation) in Sanming city was described in the paper which centers on medical insurance.Tapping full potentials of the medical insurance,the city achieved efficient synergy among healthcare,medical insurance and medication systems.This reform has trimmed out inflated drug pricing to some extent for rooms of maneuver of medical service pricing changes,thus curbing excessive growth of medical costs successfully.The authors proposed areas of further improvements including the relationship between achieving such objective as curbing medical expenditure,and advancement of technical/medical service capacity;that between integrative control of medical insurance expenditure and protection of people's health;the equilibrium of interests between medical insurance,healthcare and medication.All these will contribute to the goal of healthy patients flow and a hierarchical medical system.

Objectives To investigate the prevalence of childhood asthma in 2000～2010,to find the changes of childhood asthma in distribution characteristics,precipitating factors,diagnosis and treatment status,and to provide scientific data for the improvement of the prevention and management of asthma in children in Kunming city,China.Methods Children were selected by random cluster sampling.Standardized preliminary questionnaire was used for screening out possible patients in the two surveys of 2000 and 2010.Diagnosis of asthma was confirmed by diagnostic criteria in suspected asthmatic children.Asthmatic children were further asked for past diagnosis and treatment with the questionnaire of asthma in children.Double entry and validation were adopted for all data and analysis was carried out using Epi-Info software.Results Compared with 2000,the total asthma incidence rate increased significantly from 0.88％ to 1.40％ (x 2=12.52,P＜0.05),the coincidence rate of final diagnosis and previous diagnosis increased from 22.8％ to 51.3％ (x2 =19.23,P ＜0.05) and the proportion of acute exacerbation of asthma reduced from 40.2％ to 19.3％ (x 2 =12.54,P＜0.05) in 2010.Compared with 2000,Antibiotics use rate reduced from 97.8％ to 80.0％ (x 2=14.28,P ＜0.05) and the proportion of inhaled corticosteroid increased from 12.0％ to 64.0％ (x 2=60.53,P＜0.05).Conclusion Compared with 10 years ago,the total asthma incidence of childhood asthma aged 0 ～ 14 year old in Kunming city was significantly increased.The coincidence rate of final diagnosis and previous diagnosis increased and the proportion of acute exacerbation of asthma reduced.Antibiotics use rate reduced and the proportion of inhaled corticosteroid increased.The treatment and management of asthma in children awaits improvement as well,especially in reducing the rate of missed diagnosis in children with asthma and regulating the use of corticosteroids and bronchodilators inhaling treatment and reduces the use of the proportion of antibiotics.

Objective To investigate the clinical characteristics of childhood anaphylactoid purpura.Methods Seven hundred and sixty children with anaphylactoid purpura were included in this retrospective study.The clinicopathological features of childhood anaphylactoid purpura were analyzed,including age at onset,gender,season at onset,clinical and pathological manifestations,and complications such as purpura nephritis.Results Childhood anaphylactoid purpura commonly affected preschool and school-age children,and usually occurred in winter or spring.Of these patients,265 (34.87％) had gastrointestinal symptoms,298 (39.21％) had joint involvement,and 223 (29.34％) had renal impairment.Purpura nephritis mainly manifested as haematuria,proteinuria and nephritic syndrome,and was diagnosed in 91.91％ (91) of the patients receiving renal biopsy.The pathological grade of purpura nephritis varied from Ⅱ to Ⅲ in these patients.The distribution pattern of purpura was associated with complications.Conclusions Anaphylactoid purpura has age and season predilection.Purpura in both lower and upper extremities is likely to be complicated by gastrointestinal haemorrhage and joint involvement,and lower extremity purpura is more frequently to be complicated by nephritis than purpura in both lower and upper extremities.In general,childhood anaphylactoid purpura is a mild condition with a good prognosis.

4"-O-isovaleryltransferase gene (ist) was regulated by positive regulatory genes of midecamycin 4"-O-propionyltransferase gene (mpt) in Streptomyces lividans TK24. A BamH I ~8.0 kb fragment from Streptomyces mycarofaciens 1748 was proved that it contained mpt gene and linked with two positive regulatory genes, orf27 and orf28. Orf of mpt was replaced by orf of ist and linked with two regulatory genes or orf27 single, and individually cloned into the vectors pKC1139 or pWHM3 (high copy number), and then transformed into S. lividans TK24. The levels of mpt and ist expression were evaluated by the bio-tramsformation efficacy of spiramycin into 4"-O-acylspiramycins in these transformants. The results showed that 4"-O-isovalerylspiramycins could be detected only in the transformants containing the plasmids constructed with pWHM3. The efficacy of bio-transformation of the transformants containing two regulatory genes was higher than that of orf27 single. So, the positive regulatory genes system of mpt gene could enhance ist gene expression.
Acyltransferases ; genetics ; metabolism ; Bacterial Proteins ; genetics ; metabolism ; Gene Expression ; Genetic Vectors ; Plasmids ; Spiramycin ; analogs & derivatives ; biosynthesis ; Streptomyces ; enzymology ; genetics ; Streptomyces lividans ; metabolism ; Transformation, Genetic