each group were sacrificed, respectively. Distributions of BrdU positive cels and ChAT positive cels were detected by S-P immunohistochemical method. The learning and memory abilities of rats were detected by Morris water maze system.
RESULTS AND CONCLUSION:BrdU positive cels were mainly distributed in the cortex and hippocampus, especialy around the blood vessels, and there was the presence of focal aggregation. A smal amount of BrdU positive cels were observed in the basal ganglia and thalamus as wel as in the ependyma. BrdU positive cels were counted at different time after operation. The number of BrdU positive cels decreased with time, and only a smal number of BrdU positive cels were observed at 60 days after transplantation. The number of ChAT positive cels at different time after transplantation was ranked as folows: neural stem cel transplantation group > model group > sham operated group (P < 0.05). Compared with the model group, the time for searching the platform was significantly lower in the neural stem transplantation group and sham operated group, but the number of crossing the platform was significantly higher in the neural stem cel transplantation group and sham operated group (P < 0.05). The results show that neural stem cels could be transplanted into the rats with vascular dementia, and the cels could survive and migrate in the brain of rats and significantly improve the learning and memory ability. This mechanism may be related to the differentiation and growth of cholinergic neurons in the hippocampus.

In this consideration,the paper described the imperatives of drug safety,constraints of governance by the government,and advantages of social co-governance,proposing the necessity to establish aFive-in-One (referring to the involvement of the government,enterprises,industry associations,media and the public) drug safety social co-governance.In its analysis of the present dilemma o[drug safety governance,the authors proposed such measures as perfecting legal and institutional system,reforming governmental power allocation mechanism,improving the incentive mechanism,innovating governance means and improving social governance ability,for the purpose of enhancing such a co-governance pattern.

Objective To prepare the 99Tcm-labeled human epidermal growth factor receptor type 2 (HER2) affibody molecule ZHER2:342 and evaluate its receptor binding specificity in vitro.Methods The molecular ZHERa:342 was labeled with 99Tcm using the ligand exchange method.The labeling efficiency and radiochemical purity were measured by HPLC.The major factors,such as the mass of SnC12 and NaOH and reaction time were analyzed,and the optimal method was summarized.Cell binding kinetics and cellular retention of the probe were investigated in HER2-expressing SKOV-3 cells and MDA-MB-231 cells with low HER2 expression respectively.HER2 binding specificity of 99Tcm-ZHER2:342 was analyzed by a pre-injection of excess unlabeled ZHER2:342 to saturate HER2 receptors.One-way analysis of variance and two-sample t test were used.Results The optimal labeling procedure was as follows:5 μg (1 g/L) of ZHER2:342 was mixed with 5 μg of NaOH (1 g/L),then 8.8 μg SnC12(1 g/L,solution) was added,followed by 150 μl (37 MBq) 99TcmO4-solution,and finally the mixture was slightly vortexed and incubated for 1 h at room temperature.99TcmZHER2:342 was stable in vitro with a high labeling efficiency of (98.10± 1.73)％.The radiochemical purity was ＞ 98％,and was more than 85％ after the incubation for 24 h in saline and fresh human serum.The cell binding of 99Tcm-ZHER2:342 with HER2-expressing SKOV-3 cells gradually increased over time with a peak of (9.95± 1.02)％ at 6 h.The binding of 99Tcm-ZHER2:342 in SKOV-3 cells was significantly higher than that in MDA-MB-231 cells at every time point (5.68-9.88 vs 0.56-2.11 ; t:from-34.50 to-13.14,all P＜0.01).The labeled molecular probe retained the capacity to bind specifically to HER2-expressing SKOV-3 cells since the cell binding decreased from (9.95 ± 1.02) ％ to (2.11 ±0.27) ％ after receptor saturation (t =-13.14,P＜0.01).Conclusions 99Tcm-ZHER2:342 has a high labeling efficiency,good stability and optimal binding specificity.These characteristics enable it to be a promising molecular probe for HER2-targeting imaging.

Objective To compare the differences between two statistical methods for evaluating non-sensitivity of pathogenic bacteria to antimicrobial agents,and explore effect of non-consideration of clinical background on evalua-ting extent of bacterial resistance.Methods Data of Staphylococcus aureus and Acinetobacter spp .in a hospital in the first half year of 2008,2010 and 2013 were collected and conducted statistical analysis with two methods (me-thod 1 :based on all clinically isolated bacteria;method 2 :based on infection-related non-repetitive bacteria),two methods for evaluating bacterial non-sensitive rates to antimicrobial agents were compared.Results The non-sensi-tive rates of Acinetobacter spp .to various antimicrobial agents :statistical results by using method 1 were generally higher than those using method 2,absolute difference between two statistical methods was 10.46%-33.77%;the non-sensitive rates of Staphylococcus aureus to various antimicrobial agents :except compound sulfamethoxazole in 2010 and 2013(difference were 6.17% and 10.21 % respectively),penicillin G (difference was 3.86%),erythromy-cin (difference was 2.71 %),and azithromycin in 2013 (difference was 2.43%),statistical results by using method 1 were generally higher than those using method 2,absolute difference between two statistical methods was 0-18.04%.Conclusion There are deviation in the non-sensitive rates of bacterial strains to antimicrobial agents by using two different statistical methods,deviation is larger in Acinetobacter spp ..The resistance level might be incorrectly higher when evaluating the resistance status without considering clinical background of bacteria.

Objective To evaluate the in vitro effect on tumor cell uptake,tumor imaging and in vivo biodistribution of 99Tcm-epidermal growth factor receptor (EGFR) mRNA antisense PNA probe mediated by cationic liposome.Methods The oligonucleotide with sequence complementary to part of the EGFR mRNA antisense PNA was hybridized in an anti-parallel orientation targeted PNA.PNA hybridization complexes were labeled with 99Tcm by ligand exchange.The assembly of lipofectamine and 99Tcm-labeled heteroduplex was achieved by electrostatic interactions,and the radiolabeled purity was determined by reversedphase HPLC (RP-HPLC).The disparities of cell uptake in SKOV3 cells and the differences of biodistribution and molecular imaging in BALB/c nude mice bearing SKOV3 xenografts between lipofectanine-mediated 99Tcm-EGFR mRNA antisense PNA (group 1) and 99Tcm-EGFR mRNA antisense PNA (group 2) were analyzed.Two-sample t (or t') test and Wilcoxon rank sum test were used for statistical analysis.Results The labeling rates of both group 1 and group 2 were more than 95％ within 6 h.The cell uptake at 1,2,4,6,12,24 h after injection was (28.90±1.12)％,(32.76±1.20)％,(38.20±3.11)％,(41.23±1.60)％,(46.63±1.55)％ and (46.78±2.14)％ in group 1,and was (3.51±0.39)％,(3.90±0.40)％,(4.69±0.18)％,(5.91±0.26)％,(5.30±0.22)％ and (5.39±0.17)％ in group 2 respectively (t'=47.11-58.67,Z=2.80,all P＜0.05).The retention ratios showed significant difference between the two groups (t'=7.25-11.55,Z=2.80,all P＜0.05).The SKOV3 tumor could be visualized in both groups at 1 h post injection but much better visualized in group 1.The T/NT ratios were higher in group 1 at all time points (t =3.96,t'=12.65-14.69,Z=2.83-5.29,all P＜0.05).The T/NT ratios at uptake peak were 5.02 and 3.95,respectively.The probe accumulated mainly in tumor,kidneys and liver.Tumor uptake increased with time ((1.49±0.09) ％ID/g and (2.15±0.21) ％ID/g at 1 h,(3.90±0.65) ％ID/g and (5.00±0.10) ％ID/g at 6 h) after lipofectamine treatment.The ratios of tumor to contralateral muscle were also higher in group 1 (t =11.24,t' =3.96-11.94,all P＜0.05).Conclusions Lipofectamine-mediation can significantly improve the intracellular delivery of radionuclide molecular probe.Lipofectamine-mediated 99Tcm-EGFR mRNA antisense PNA can greatly improve imaging contrast and visualization of EGFR-over-expressing tumors.

Objective To analyze the influencing factors for doctors' prescription of essential medicines at county hospitals of Anhui province.Methods Multi-stage random sampling method was designed to conduct an investigation for doctors at nine county hospitals in Anhui province,and SPSS 1 6.0 was used to conduct descriptive statistical,chi-square test and binary logistic regression.Results 50.8% respondents reported that they had prescribed essential medicines with the rate of less than 60%. The factors of doctors'prescription for essential medicines are work experience,average monthly income, policy awareness, recognition, training willingness, training times, hospital support, medication preferences,and drug marketing.Conclusion The prescription rate of essential medicines in the sampled hospitals is low,and the targeted comprehensive intervention measures should be taken to promote prescription rate of essential medicines in county hospitals.

Objective To study the resistance and molecular profiles of Staphylococcus aureus strains isolated from the clinical specimens.Methods Antimicrobial susceptibility was tested with 56 strains of Staphylococcus aureus isolated from a hospital from May to November 2011.The mecA and pvl genes were detected.The spa genetic types were analyzed.Results A total of 21 (37.5%)Staphylococcus aureus strains were resistant to methicillin (MRSA)and 35 (62.5%)were sensitive to methicillin (MSSA).Nineteen of the 21 (90.5%)MRSA strains carried mecA gene.Compared with MSSA,MRSA were much less sen-sitive to rifampin,fluoroqunolones,tetracycline and gentamicin (P <0.05).All the MRSA isolates were susceptible to vanco-mycin,linezolid,tigecycline,quinupristin-dalfopristin and nitrofurantoin.Six spa types were identified among the MRSA strains.Type t030 was the most prevalent,accounting for 66.7% (14/21)of all the MRSA strains.MRSA-t030 and MRSA-t002 were resistant to multiple antibiotics.Eighteen spa types were identified among the MSSA strains.Type t189,t377 and t034 were the top three spa types of MSSA,accounting for 14.3%,14.3% and 11.4%,respectively.A new MSSA spa typ-ing strain new1 was isolated from pus.There were five Panton-Valentine leukocidin (PVL)-positive isolates,3 of which was MSSA-t189 type. Conclusions Type t030 is the most prevalent spa type among clinical MRSA strains,which is resistant to many kinds of antibiotics and widely spreads in the hospital setting.There are many different spa types a-mong the MSSA strains.Type t389,t377 and t034 are the top three spa types of MSSA.

Background and purpose:Epidermal growth factor receptor (EGFR) gene mutation is the most important predictive factor for determining the effectiveness of EGFR tyrosine kinase inhibitors (TKIs) for non-small cell lung cancer (NSCLC). This study aimed to determine the clinical application value of mutation-speciifc immu-nohistochemistry forEGFR mutation detection in NSCLC.Methods:Mutation-specific immunohistochemistry and ampliifcation refractory mutation system (ARMS) were used simultaneously to detectEGFR gene mutation status in 290 lung cancer specimens. The sensitivity, speciifcity, positive predictive value (PPV) and negative predictive value (NPV) of mutation-speciifc immunohistochemistry for detectingEGFR gene mutations were evaluated. The consistency was analyzed between mutation-speciifc immunohistochemistry results and ARMS results.Results:With ARMS testing as the gold standard, when a cutoff value of score 1+ was used as positive by immunohistochemistry, the sensitivity of mutation-speciifc immunohistochemistry forEGFR gene mutation was 72.92%, speciifcity 95.20%, positive predictive value 93.75% and negative predictive value 78.08%. The accuracy of immunohistochemistry was obviously different when variousEGFR gene mutations were detected. The sensitivity of immunohistochemistry for exon 19 deletion was only 55.55%, but speciifcity was above 99%. When immunohistochemistry score was 1+, the sensitivity for L858R mu-tation was 90.27%, whereas speciifcity was 95.86%. When immunohistochemistry score was 2+ or 3+, the speciifcity for L858R mutation was 98.63%-100%. The results of mutation-speciifc immunohistochemistry were ifnely correlated with mutation status determined by ARMS assay (P<0.001, Kappa value: 0.612-0.864). Mutation-speciifc immunohis-tochemistry can directly determineEGFR gene mutation abundance at the cellular level.Conclusion:Mutation-speciifc immunohistochemistry could be an effective supplemental method toEGFR molecular tests.

ObjectiveTo encourage development of county-level hospitals by building a performance appraisal indicator system for such institutions. Methods Using the PATH model ( a performance appraisal tool for hospital ) quality improvement, an appraisal system was built for such institutions. Centering on patients, this system encompassed such dimensions as public benefits, quality of care and safety, staff and hospital development. Results This system consisted of six level-1 indicators, 21 level-2 indicators and 70 level-3 indicators, each given due weight. Conclusions This indicator system centers on patients, follows guidance of public benefits, and aims at continuous quality improvement, making it an effective in evaluating hospital performance and providing reference for the decision-makers to promote and adjust medical reform policies.

Objective:To investigate the prenatal genetic features and the factors influencing the prognosis of twin reversed arterial perfusion sequence (TRAPS) in monochorionic twin pregnancies.Methods:A total of 99 cases diagnosed with TRAPS by prenatal ultrasound in the First Affiliated Hospital of Sun Yat-sen University from July 1, 2007, to December 31, 2021, were included retrospectively. The prenatal genetic features of acardiac and pump twins were analyzed. Eighty-nine cases were followed up and divided into two groups: the expectation group ( n=45) and the intrauterine intervention group (all underwent radiofrequency ablation, n=44) and the pregnancy outcomes were compared between the two groups. After excluding eight cases without complete ultrasound data, the expectation group was further divided into two subgroups: the pump fetus survival ( n=28) and the pump fetus death groups ( n=9), and the survival subgroup was divided into the spontaneous arrest group ( n=16) and coexistence group ( n=12) according to whether or not the blood flow stopped spontaneously.The relationship between ultrasonic indexes and pregnancy outcome was compared between the groups. Chi-square test (or Fisher's exact test), univariate logistic regression analysis and receiver operating characteristic (ROC) curve were used to analyze the relationship between the estimated acardiac to pump twin weight ratio (A/P Wt) and the pregnancy outcome of the pump twin in the expectation group. Results:(1) The median gestational age at diagnosis of the 99 TRAPS cases was 16.4 weeks (13.3- 21.3 weeks) and 32% (32/99) were diagnosed in the first trimester. Most of the cases were monochorionic diamniotic pregnancies (72/99, 73%). The survival rate of the pump twins was 71% (63/89). (2) Chromosome karyotyping and/or chromosomal microarray analysis was performed in 19 acardiac twins and 82 pump twins. The detection rate of genetic abnormalities in the acardiac twins was higher than that in the pump twins [4/19 vs 5% (4/82), Fisher's exact test, P=0.039]. Chromosomal microarray analysis was performed in 54 pump twins with normal karyotypes and the results showed three (6%) with genetic abnormalities. (3) In the expectation group, the area under ROC curve for the prenatal A/P Wt were 0.913 in predicting pump twin death and 0.807 in predicting spontaneous cessation of blood flow in the cardiac twin, and the cut-off values were 0.24 (sensitivity: 88.9%, specificity: 96.4%) and 0.11 (sensitivity: 75.0%, specificity: 81.3%), respectively. The survival rate of pump twins with abnormal cardiac function after intrauterine intervention was higher than that of the expectant group [72% (18/25) vs 3/11, Fisher's exact test, P=0.025]. Conclusions:TRAPS can be diagnosed in the first trimester and commonly occur in monochorionic diamniotic pregnancies. The detection rate of genetic abnormalities in the acardiac twins is higher than that in the pump twins. Prenatal A/P Wt>0.24 indicates the death of the pump twin and prenatal A/P Wt≤0.11 suggests a high possibility of spontaneous cessation of blood flow in the acardiac twin. Radiofrequency ablation is an effective method for improving the prognosis of the pump twin with cardiac dysfunction.