OBJECTIVE To study penicillin resistance in Staphylococcus aureus and the activity of ?-lactamase.METHODS The strains of S.aureus both sensitive and resistant to penicillin were inoculated into the media with penicillin and then incubated in 37 ℃.The number of the bacteria and the activities of ?-lactamase,were determined respectively at varying times.RESULTS In the media with 64 ?g/ml penicillin,the number of the sensitive strain decreased gradually in 24 h of culturing.The number of the resistant strains decreased at first 6 h and then the number increased in subsequent 24 h.The activity of penicillin did not be changed in the media with the sensitive strain.The activitiy of penicillin was decreased obviously with the resistant stains.In the media without penicillin,the ?-lactamase activities of the resistant stains were stable until 24 h of culturing,while the ?-lactamase activities were increased gradually in the media with penicillin.CONCLUSIONS The growth of early stage of S.aureus can be inhibited obviously by penicillin.?-Lactamase would be induced largely in resistant S.aureus.

BACKGROUND: Diabetic retinopathy is a commonly chronic-vascular complication in a course of diabetes mellitus (DM), and its relation with apoptosis and changes of ion level needs to be proved.OBJECTIVE: To observe apoptosis and changes of Na+ and K+ contents in retinal tissue of DM rats.DESIGN: Randomized controlled study.SETTING: Department of Ophthalmology, Liuzhou Municipal People's Hospital.MATERIALS: The experiment was completed at the Department of Ophthalmology, Liuzhou Municipal People's Hospital. A total of forty adult male Wistar rats, aged 20 months, weighing 320-350 g, were provided by Animal Center of Medical College Affiliated to Sun Yat-sen University.METHODS: Forth Wistar rats were randomly divided into control group and experimental group with 20 in each group. Streptozotocin was used to induce DM in the experimental group. Apoptosis and changes of Na+ and K+ contents in retinal tissue were measured on the 4th, 6th, 12th and 16th weeks after DM onset. Rats in the control group were injected only with the same volume of citrate buffer solution. Then, correlations on the aspect of fasting blood glucose (FBG), hemoglobin glycosylation (HbAlc), Na+ and K+ contents and DM course were analyzed between the two groups.MAIN OUTCOME MEASURES: ① Na+ and K+ contents; ② FBG concentra tion and HbAlc level; ③ changes of apoptosis; ④ correlations among markers.RESULTS: Apoptosis could be detected in retinal tissue in the experimental group at 4 weeks after DM onset, and with course elongating, level of apoptosis was aggravated gradually. Na+ concentration was increased in retinal tissue, but K+ concentration was decreased (P ＜ 0.01 or 0.05). Levels of apoptosis in retinal tissue in the experimental group were positive correlation with FBG concentration, HbAlc level, Na+ content and DM course (r=7.584, 7.844, 7.369, 6.246; P ＜ 0.01); however, they were negative correlation with K+ content in retinal tissue (r=7.658, P ＜ 0.01).CONCLUSION: There are apoptosis and abnormal Na+ and K+ contents in retinal tissue of DM rats. Moreover, these changes may be one of pathological bases of diabetic retinopathy.

Objective To explore the effect of endoscopic transnasal dacryocystorhinostomy(ET-DCR) by suture in the treatment of acute dacryocystitis(AD) as early as possible.Methods The clinical data of 32 patients with unilateral AD who underwent ET-DCR by suture as early as possible were retrospectively analyzed.Results All patients presented clear anatomic structure,intraoperative hemorrhage increased in 3 cases,swelling and pain was rapidly relieving in all patients in the first day of postoperation,the mean resolution time of congestion and swelling in the middle canthus was average 3 days(range 1-6 days),no spread of infection occurred,no facial scar appeared in all patients except one case of abscess rupture.Complete complaint relief in 26 cases,slight epiphora presented in 6 patients who confirmed for lacrimalduct obstruction and cured by intubation,and all ostial patency with no AD recurrences at the mean follow-up of 2 years (range 12 months-5 years).Conclusion ET-DCR by suture as early as possible can be used to cure acute dacryocystitis and it is effective safe and economy.

Objective To investigate the clinical value of endoscopic transnasal dacryocystorhinostomy ( ET-DCR) by suture techniques.Methods 85 patients of 98 eyes with chronic dacryocystifis were randomly divided into the two groups:control group ( without suture) and observation group ( by suture) .All cases were followed up for more than 12 months.The cure rates and occurrence of granulation tissue were compared between the two groups. Results The cure rate of the observation group ( 96.00%, 48/50 ) was higher than that in the control group (81.25%,39/48) (χ2 =5.35,P<0.05). During process of following up,the occurrence of granulation tissue at the ostium margins accounted for 14.00%(7/50) in the observation group and 31.25%(15/48) in the control group (χ2 =4.19,P<0.05).Conclusion ET-DCR by suture techniques reduces the formation of granulation tissue and improves the cure rate.Especially, ET-DCR by suture techniques for the small lacrimal sac of patients may have special advantages.

Objective To invesigate the value of contrast-enhanced spiral CT scan in diagnosing renal pelvic carcinoma.Methods All 35 cases with renal pelvic carcinoma confirmed by surgical pathology underwent plain and contrast-enhanced (including 4 phases) spiral CT scans before operation.CT data were reviewed retrospectively in comparison with surgical and patholgical results.Results CT findings of renal carcinoma could be classified into 3 types:type Ⅰ,the lesions limited within the renal pelvis in 25 cases;thype Ⅱ,the lesions were out of the renal pelvis and had indefinable margins with the renal parenchyma in 6 cases;type Ⅲ ,only showed the pelvic wall thickened with hydronephrosis in 4 cases.On contrast-enhanced CT scan,inhomogeneous enhancement of the lesions was presented in cortical phase,the intensity of enhancement was not obviously changed in 13 cases in parenchymal and excretion phases,but the lesions were still hypointense in comparison with renal parenchyma,14 cases demonstrated inhomogeneous enhancement of the lesions in delayed phase.Conclusion Contrast-enhanced spiral CT scanning is valuable in diagnosing renal pelvic carcinoma and renal delayed phase should be emphasized.

Objective To investigate the effects of sevoflurane preconditioning on autophagy after traumatic brain injury (TBI) in rats and the role of C-Jun N-terminal kinase (JNK) signaling pathway.Methods Sixty adult male Sprague-Dawley rats,weighing 220-250 g,were randomly divided into 4 groups (n =15 each) using a random number table:sham operation group (group S),group TBI,TBI + sevoflurane preconditioning group (group TBI + Sevo) and TBI + sevoflurane preconditioning + JNK inhibitor SP600125 group (group TBI + Sev + SP).TBI models were established using Feeney' s method.In TBI + Sev and TBI + Sev + SP groups,the rats inhaled 2.4％ sevoflurane for 30 min once a day for 4 concecutive days,and TBI was produced at 24 h after the end of sevoflurane preconditioning.In TBI + Sev + SP group,SP600125 (6 mg/kg) was injected intrapetitoneally at 30 min after TBI.Five rats were chosen at day 1,3,and 7 after TBI,and neurological deficit score (NDS) was measured.The rats were then sacrificed and brains were removed to measure brain water content,expression of LC3 lⅡ and Beclin-1 mRNA (using PCR),and expression of LC3 Ⅱ,Beclin-1,JNK and phosphorylated JNK (p-JNK) (by Western blot).Results Compared with group S,brain water content and NDS were significantly increased,and the expression of LC3 Ⅱ and Beclin-1 protein and mRNA,JNK,and p-JNK was up-regulated in the other three groups.Brain water content and NDS were significantly decreased,and the expression of LC3 Ⅱ and Beclin-1 protein and mRNA,JNK,and p-JNK was down-regulated in TBI + Sev and TBI + Sev + SP groups as compared with group TBI,and in TBI + Sev + SP group as compared with TBI + Sev group.Conclusion The mechanism by which sevoflurane preconditioning mitigates TBI is related to inhibiton of activation of JNK signaling pathway and decreased autophagy in rats.

BACKGROUND:Culture condition,isolation method and efficiency are different in reported human umbilical cord-derived mesenchymal stem cells,which lack of unified identification standards.Therefore,it is necessary to establish a high-efficiency and economical culture system for human umbilical cord-derived mesenchymal stem calls(hUCMSCs).OBJECTIVE:To isolate hUCMSCs and induced differentiate into adipocytes and osteblasts.METHODS:The hUCMSCs were isolated form human umbilical cord by tissue adherence and digested with collagenase.The morphology,proliferation and immunophenotype of the 3rd passage cells were analyzed,and then cells were induced to osteogenic and adipogenic differentiation in vitro.RESULTS AND CONCLUSION:The hUCMSCs isolated from human umbilical cord by tissue adherence and digested with collagenase could be cultured and proliferated in vitro.Flow cytometry analysis revealed that the hUCMSCs were positive for CD29 CD44,CD59,CD105,but were negative for CD40,CD86 and HLA-DR.These calls could be induced to differentiate into adipocytes and osteblasts under proper inducing conditions.The hUCMSCs retained the appearance and phenotype even after being expanded more than 40 passages in vitro.This confirmed that the existence of MSCs in human umbilical cord and they had the capacity of differentiating into adipocytes and osteblasts.

Objective:To investigate association between genetic polymorphism in the grainyhead-like 2 gene (GRHL2)and noise-induced hearing loss (NIHL)in the Chinese population.Methods:A matched case-control association study was employed,In which,3 790 workers exposed to continuous and steady-state occupational noise in a steel factory participated.The questionnaires were adopted to col-lect individual features and audiometry tests performed.In the sstudy,286 subjects were diagnosed as ca-ses,Which were each designated on the basis of the matched criterion,and 286 paired samples were se-lected finally.Noise intensity was measured according to the standards given in ‘Measurement of Noise in the Workplace’(Occupational Health Standard of the People’s Republic of China,GBZ /T1 89.8 -2007).Cumulative noise exposure (CNE)was calculated,according to monitoring data on A-weighed sound pressure level and employment time.Genomic DNA was obtained from peripheral blood samples using 2 mL DNA extraction Kit following the manufacturer’s protocol.Five single nucleotide polymor-phisms (SNPs)of GRHL2 were genotyped by multiplex SNP genotyping kit.The continuous variables and categorical variables were analyzed by t-test and chi-square test respectively.Multivariate Logistic re-gression was used to test the association between genetic frequency and disease status,with adjustments for the possible confounding variables.The haplotypes were established and their frequencies in the two groups were assessed by haploview and phase softwares.Results:All the five SNPs (rs373571 3, rs3824090,rs373571 4,rs373571 5 and rs61 1 41 9)were in Hardy-Weinberg equilibrium (HWE)(P >0.05).The subjects carrying rs373571 5 GG genotype had a higher NIHL risk than those carrying the GA genotype under the co-dominant model (OR =0.644,95% CI:0.442 -0.939,P =0.022)after ad-justment for height,blood pressure,drinking status and smoking status.After being stratified by CNE,in the CNE ≥ 98 dB (A)group,rs373571 5 polymorphism was associated with the NIHL under the co-dominant model (OR =0.509,95% CI:0.281 -0.923,P =0.026)after adjustment for height,blood pressure,drinking status and smoking status as well.However,no statistical significant difference was found in variant genotypes of the other SNPs between the case and control subjects.Four-locus (rs373571 3,rs3824090,rs373571 4 and rs373571 5)haplotypes were constructed,and no risk or protec-tive haplotypes was identified.Conclusion:It is suggested that GRHL2 polymorphisms may be associated with development of NIHL.

Objective To develop an ideal hypertension combined hyperlipidemia(HP/HL)rat model by feeding spontaneously hypertensive rats(SHRs)with high fat diet, and to evaluate the pathological changes in target organs including heart and kidney. Methods Twenty 3-week old male SHRs were randomly divided into two groups: normal fat control group(SHR-NC)and high fat group(SHR-HF). Moreover,ten 3-week old male Wistar-Kyoto rats(WKY)were taken as the model control group(WKY-NC). The rats in SHR-HF group were fed with high-fat diet to induce HP/HL, while rats of WKY-NC and SHR-NC groups were fed with normal diet. The systolic blood pressure(SBP)and body weight were measured every week. At the end of the experiment, the rats were sacrificed to take serum samples for blood lipid analysis including high density lipoprotein(HDL-C), low density lipoprotein(LDL-C), total cholesterol(TC)and triglyceride(TG). Heart and kidney tissue samples were collected to examine the pathological changes using HE and Masson staining. Results Compared with the SHR-NC group, the SHRs fed with high-fat diet for 23 weeks presented significant increase of blood pressure and TC, TG, LDL-C, and decrease of HDL-C. The HP/HL rat model showed pathological changes in the HP/HL target organs, heart and kidney. Renal tissues were severely damaged and showed a large area of fibrosis. Besides, left ventricular hypertrophy and myocardial fibrosis were also observed. Conclusions A HP/HL rat model is successfully constructed by feeding SHRs with high-fat diet for 23 weeks. Most importantly,this model exhibits progressive renal and cardiac alterations, similar to those of patients with HP/HL. This HP/HL rat model may become widely used for evaluation of HP/HL therapeutic drugs.

Mycobacterium abscessus complex (MABC), a rapidly growing nontuberculous mycobacterium, has received increasing attention worldwide due to its rising isolation rate. The similarity of symptoms between MABC pulmonary disease and tuberculosis, different treatment methods required by different subtypes, as well as high levels of innate, adaptive and acquired antibiotic resistance, make MABC treatment more difficult and lead to unfavorable clinical outcomes of patients. This article reviews the basic characteristics, common antibiotic resistance mechanisms, as well as diagnosis and treatment of MABC, to provide reference for future research and clinical treatment of MABC lung disease.