Objective To test the releasing property of a self-developed plastic drug delivery implant of anti-infective nano-hydroxyapatite(nano-HA)so as to provide a new local drug delivery system(LDDS)for treatment of osteomyelitis.Methods The nano-HA was used as the core carrier to load gentamicin(GM).It was coated with poly hydroxybutyrate-co-hydroxyvalerate /polyethylene glycol(PHBV/PEG)to prepare the nano-HA-PHBV/PEG-GM microspheres which were mixed with the fibrin sealant(FS)to develop a plastic implant.Then its antibacte rial and in vitro releasing properties were investigated.Results The plastic LDDS implant was found to have a fine drug delivery capability.The bacterial growth inhibition zone was found around the LDDS for 56 days in the antibacterial test.Three samples were soaked with liquid of PBS(phosphate buffered saline).The titer of GM released within the first day was 154.3 ?g/mL,and then the releasing maintained a slow level in the following days.After 49 days'releasing,the titer was 6.9 ?g/mL which was still higher than the MIC(2 ?g/mL)(minima l inhibitory concentration)of GM.Conclusion The plastic LDDS has a fine in vitro releasing property and may have a widespread application in treatment of osteomyelitis.

Objective To investigate the attitude of medical students towards standardized resident training in Shanghai and to provide references for policy adjustment.Methods Self-made questionnaire was used to investigate the attitude of 267 clinical medical students towards standardized resident training in Shanghai.Reference reviewing and expert consultation were also performed.Results Nearly eighty percent of students believed that they had basic knowledge of the training.Two thirds of students hold objective attitude towards the policy.Conclusions Income and pressure in finding jobs are the main reasons why students object the policy.Standardized resident training program need to improve in aspects of advertisement,incoming,quality of teaching staff,connection between medical education and training.

Objective: This study was designed to assess the protective effects of high-dose aprotinin on isolated rat hearts from ischemia-reperfusion injury. Method: The study consisted of two groups of rats. An isolated rat working heart model was established. Group A (n=16), received cardioplegia with high-dose aprotinin. Group B (n=16), received same cardioplegia only. The rat hearts were perfused for 30 minutes, then arrested for 40 minutes and reperfused for 30 minutes. The hemodynamic parameters, myocardial creatine kinase (CK) and myocardial ultrastructure were measured before ischemia and during reperfusion. Results: Recovery of cardial function, coronary flow and myocardial ultrastructure in group A was significantly better. CK level was lower in group A. Conclusion: High-dose aprotinin (1×106 KIU/L) may reduce myocardial ischemic and reperfusion injuries.

Objective To explore post-operative treatment and intensive care of infants with congenital heart disease(CHD).Methods Clinical data of post-operative treatment and intensive care in 264 infants with CHD were analyzed retrospectively from May.1998 to Apr.2006.Among them,256 cases underwent radical operation,and 8 cases with palliative operation.Results Sixteen cases died early.Among them,after operation,there were 8 cases with Fallot′s syndrome,2 cases with complete atrioventricular canal anomalous,3 cases with ventricular septal defect(VSD)and pulmonary hypoplasia(PH),1 case with tricuspid atresia,1 case with single ventricle,and 1 case with persistent truncus arteriosus.Causes of death include low cardiac output,acute renal failure,degree of Ⅲ atrioventricular block(AVB),lung infection,respiratory failure and arrhythmia.One case with complete pulmonary vein ectopia was discharged due to post-opertative refractory hypercapnia;1 case with atrial septal defect(ASD)and patent ductus arteriosus(PDA) died of refractory heart failure due to high pulmonary arterial pressure 1 year after operation;1 case with tetralogy of Fallot died of lung hemorrhage after radical correct operation followed by palliative outflow tract deo-ppilant operation.Of them 245 cases alive,there were 233 cases with heart function grade Ⅰ,12 cases with grade Ⅱ.Conclusion Correct management of respiratory system,systemic electrocardial care,handling with arrhthymia on time,low cardiac output and nutritional support are the important measures in improving survival rate of infants with CHD.

An investigation of the dietary conditions and the growth of children was made from February to May 1982 in 14 nurseries and kindergartens in G districts of Tianjin.The results showed: the calorie intake was lower than 80% of the daily allowance of normal children in 11 of 14 nurseries and kindergartens while the protein intake was lower than 70% of the daily allowance in 12. The levels of other nutrients were also lower. The heights and body weights of children in these institutions belonged to B class of 6 grades by Zhou Qi-yuan.The causes of calorie and protein insufficiency and some suggestions were discussed.

OBJECTIVE To investigate the ?-lactamases in Klebsiella pneumoniae strains isolated from the elderly patients.METHODS We had an observation on 20 strains of Klebsiella pneumoniae about 15 kinds of ?-lactamase gene test(blaTEM,blaSHV,blaLEN,laOKP,blaCTX-M-1 group,blaCTX-M-2 group,blaCTX-M-9 group,blaOXA-1 group,blaOXA-2 group,blaOXA-10 group,blaGES,blaPER,blaVEB,blaDHA,and blaACT-1).RESULTS Six kinds of ?-lactamase genes had been found out from these 20 strains of K.pneumoniae,namely,blaTEM,blaSHV,blaCTX-M-1 group,blaCTX-M-9 group,blaOXA-1 group,and blaDHA.Their positives were 95%,30%,50%,5%,5% and 15%.Among these 20 strains of K.pneumoniae,there were 19 ones of K.pneumoniae which at least contained 1 kind of ?-lactamase genes.Fifteen strains of K.pneumoniae were found containing more than 2 kinds of ?-lactamase genes,at the same time.Some were even tested out having 4 kinds of ?-lactamase genes.CONCLUSIONS The resistance of ?-lactamase antibiotics of these 20 strains of K.pneumoniae has a close relative to the number of ?-lactamase.

OBJECTIVE To investigate the chloramphenicol-resistant gene in Escherichia coli strains isolated from the old patients.METHODS Twenty strains of E.coli were clinically isolated.The resistance genes were analyzed by polymerase chain reaction(PCR) and verified by DNA sequencing.RESULTS The positive rates of catB and cmlA were 20% and 20%,respectively.Two strains of E.coli were found containing catB gene and cmlA gene.CONCLUSIONS The resistance to chloramphenicol in these 20 strains of E.coli has a close relation to antimicrobial-resistance gene existed,and the genes of catB and cmlA in E.coli are all firstly found and reported in China.

OBJECTIVE To investigate the prevalence of sulfamethoxazole/trimethoprim(SXT)-resistance genes and drug resistance in Escherichia coli isolates from the old patients.METHODS Drug resistance of 20 E.coli strains were analyzed.The SXT-resistance genes(sul1,dfrA1,dfrA12 and dfrA17)were detected by polymerase chain reaction(PCR).The PCR products were purified and sequenced.RESULTS In 20 E.coli strains,95.0% were SXT resistant.The positive rate of genes of sul1,dfrA12 and dfrA17 were 80.0%,20.0% and 65.0%.Gene of dfrA1 was not detected out,17 strains of E.coli were found dfrA gene.The SXT-resistance gene dfrA or sul1 was detected in 18 of the 20 strains.CONCLUSIONS The SXT resistance of E.coli can be caused mainly by gene expression of dfrA and sul1,and the genes of sul1,dfrA12 and dfrA17 are all firstly found and reported in China.

Objective To investgate the value of various parameters obtained from monoexponential, biexponential, and stretched exponential diffusion?weighted imaging models in the differential diagnosis of breast lesions. Methods A retrospective study performed in 54 patients with pathologically confirmed malignant tumors(n=30), benign lesions(n=34) and normal fibroglandular tissues (n=30). All patients underwent T1WI, T2WI, dynamic enhancement and diffusion weighted MRI with multi?b values at a 3.0 T magnetic resonance imaging unit. All parameters were measured at a workstation. ADC was calculated by using monoexponential analysis(b=0, 800 s/mm2). Slow apparent diffusion coefficient (ADC?slow), fast apparent diffusion coefficient (ADC?fast), and perfusion fraction (f) were calculated using the biexponential model. Distributed diffusion coefficient (DDC) and water molecular diffusion heterogeneity index (α) were obtained from diffusion?weighted images using the stretched exponential model. All parameters were statistically compared among normal fibroglandular tissues, benign lesions and malignant tumors using Kruskal?Wallis rank sum test. Mann?Whitney U test were used for further comparisons between specific group pairs. ADC values were compared with ADC?slow and DDC for different groups by paired Wilcoxon test. Correlations between ADC?value, ADC?slow and DDC were assessed by using Spearman rank correlation coefficient. Receiver operating characteristic curve was used to analyze and compare the ability of these parameters in differentiation of benign and malignant breast lesions. Results The ADC, ADC?slow, f, DDC and α values were significantly different among the normal fibroglandular tissues, benign tumors and malignant tumors (P<0.05). Further differential comparisons of the four parameters between each pair showed that the ADC, ADC?slow, f, DDC and α values were significantly lower in malignant tumors than both in normal fibroglandular tissues and benign tumors(P<0.016 7). The ADC values of normal fibroglandular tissues, benign tumors and malignant tumors were significantly higher than ADC?slow and DDC (P<0.05). The f and DDC had higher area under the receiver operating characteristic curve (0.688 and 0.657 respectively). The optimal cutoff values for ADC, ADC?slow, f, DDC and α were 1.235 × 10-3mm2/s, 0.428 × 10-3mm2/s, 57.8%, 1.175 × 10-3mm2/s and 0.721, respectively. Theαvalue showed higher specificity (65.5%) and the f value had higher sensitivity (82.9%). Conclusion The parameters derived from biexponential and stretched exponential DWI could be helpful for differentiation between benign and malignant breast tumors.

Aim Toinvestigatetheeffectofhigh,me-dium and low doses of Mahuang decoction on the re-lease amount of rat hippocampal neural transmitter (Glu,Gly,Asp,GABA),then compare Mahuang de-contion with ephedra alkaloids and ephedra.Methods Ratswererandomlydividedinto6groupsandgiven orally with Mahuang decoction of high dose (calculated by ephedra 4 g·kg-1 ),medium dose (calculated by ephedra 2 g·kg-1 ),low dose (calculated by ephedra 1 g · kg-1 ),ephedra (calculated by ephedra 2 g · kg-1 ),ephedra alkaloids (ephedrine 7 mg · kg-1 , pseudoephedrine 2. 4 mg · kg-1 , methylephedrine 1. 12 mg · kg-1 )and blank control group.Samples were obtained from the hippocampus of conscious rat by microdialysis sampling technique.The content of ami-no acid neurotransmitters in dialysates was detected u-sing the established HPLC-ECD with OPA pre-column derivationmethod.Results Fouraminoacidneuro-transmitters could be well separated in 28 min.High, medium and low doses of Mahuang decoction,ephedra and ephedra alkaloids significantly increased the con-tent of these four amino acid neurotransmitters,com-pared with blank control group (P<0. 05 ).Ephedra alkaloids significantly reduced the levels of inhibitoryamino acid neurotransmitters GABA and Gly in 90 min,compared with the medium dose of Mahuang de-coction.Excitatory neurotransmitters of ASP and Glu in hippocampus showed the trend of increase first and then decrease after oral administration of Mahuang de-coction and ephedra. The levels of Glu and Asp reached peaks from 90 min to 120 min after treatment with Mahuang decoction,and also increased along with dose increase of Mahuang decoction.In comparison with the medium dose of Mahuang decoction group,the level of Glu reached peak at 90 min and 150 min in ephedra alkaloids group and ephedra group respective-ly,and the content of Glu significantly increased at peaktime.Conclusions Increasedcontentofexcita-tory amino acid neurotransmitters (Asp and Glu ) shows positive correlation with the dose of Mahuang de-coction.Other components in Mahuang decoction in-hibits the up-regulation effect of ephedra and ephedra alkaloids on Glu,and promotes the up-regulation effect of ephedra alkaloids on GABA and Gly.