Virulence determinants and drug resistance mechanisms of two linezolid-intermediate Enterococcus faecalis isolates from bloodstream infection / 中国感染控制杂志

Objective To study virulence factors and drug resistance mechanism of linezolid-intermediate Enterococcus faecalis(E.faecalis) isolated from patients with bloodstream infection.Methods Two linezolid-intermediate E.faecalis strains,namely A and B,were isolated from two patients with bloodstream infection,the treatment of two patients was analyzed.The minimum inhibitory concentration (MIC) of linezolid and vancomycin were determined.The virulence genes (esp,asa1,gelE,ace,agg,efaA,cylA,and hyl) and linezolid resistance genes (domain V region of the 23SrRNA,cfr,cfr[B],optrA) were amplified by polymerase chain reaction (PCR).PCR products of domain V region of 23SrRNA gene were sequenced and analyzed.Results Symptoms of two patients who isolated two linezolid-intermediate E.faecalis strains were controlled after accepted linezolid therapy.Strains A and B were both susceptible to vancomycin(MICs were 1μg/mL and 4μg/mL respectively),teicoplain,ampicillin,and nitrofurantoin,while intermediate to linezolid(MIC were both 4μg/mL).Two strains both contained multiple virulence factors,strain A were negative for cylA and hyl,strain B were negative for hyl and esp,but positive for other virulence genes.There was G2621T mutation in domain V region of 23SrRNA in strain A,and no variation was found in strain B.Drug resistance genes of cfr,cfr(B),and optrA were all negative in both strain A and B.Conclusion In the present study,two linezolid-intermediate E.faecalis strains isolated from patients with bloodstream infection were susceptible to vancomycin and ampicillin,although the treatment of linezolid in two patients is effective,the utilization of linezolid therapy in clinical practice still needs to be cautious.The mutation of target site is a significant resistance mechanism,it is necessary for us to pay more attention to these clinical strains which are non-susceptible to such antimicrobial agents,and the treatment strategy needs further study.

MRI diagnosis of Joubert syndrome and its differential diagnosis / 中华神经医学杂志

Objective To study the clinical and MR imaging features of patients with Joubert syndrome to improve the understanding of this disorder and the diagnosis accuracy.Methods A retrospective study of clinical and MR imaging data was performed in 3 pediatric patients had definite diagnosis of Joubert syndrome; and a comprehensive review of literature was presented.Results All 3 patients showed typical manifestations of complex brainstem malformations on MR imaging which comprised the "molar tooth sign" on midbrain level,"thin median cleft" separating cerebellar hemispheres and "bat wing" appearance of the fourth ventricle due to the cerebellar vermis hypoplasia.Clinically,hypotonia,intermittent irregular breathing pattern (with apnea in 1 patient) and developmental delay/mental retardation in infancy in all 3 patients and abnormal eye movements (episodic deviation to lateral extremes of gaze) in 1 patient were noted.Conclusion Joubert syndrome is characterized on MR imaging,but clinical data is necessary for an exact diagnosis; differentiation should be made with the other disorders due to the hypoplasia of cerebellar vermis.

Percutaneous lumbar discectomy combined with medical ozone in the treatment of lumbar disc herniation / 中华神经医学杂志

Objective To observe the distribution of O2-O3 mixture in the disc and the shrinkage of herniation after the application of percutaneous lumbar discectomy (PLD) combined with medical ozone (O3) in patients with lumbar disc herniation, and analyze the clinical effect of PLD combined with O3 and the complications of lumbar disc hemiation. Methods One hundred and twenty patients with lumbar disc herniation proved by imaging (CT or MRI) and physical examinations were divided randomly into 3 groups (n=40): PLD-treated group, O3-treated group and PLD combined with O3 treatment group.They were treated as planning and their clinical effects were observed. Results PLD combined with O3 treatment group showed a significantly lower incidence of lumbago and obviously better distribution of O3 in or outside the discs as compared with the other 2 groups. The shrinkage rate of herniation was not statistically different among the 3 groups. The effective rate in the PLD combined with O3 treatment group was 86% (34/40); that in the PLD-treated group was 83% (33/40); that in the O3-treated group was 35% (14/40). After 6-18 months follow-up, the total effective rate was as following: 87.5% (35/40) in the PLD-treated group, 77.5% (31/40) in the O3-treated group and 92.5% (37/40) in the PLD combined with O3 treatment group. No complications were found in all the 3 groups. Conclusion PLD combined with O3 is a safe and effective method in the treatment of lumbar disc herniation with less adverse reaction.

The influence of HBV/P22 protein on the apoptosis of HepG2 cells: an experimental study / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study the influence of HBV/P22 protein on the induced apoptosis of HepG2 cells.</p><p><b>METHODS</b>In vitro, two HepG2 strains were transfected with pcDNA3.1+ and pcDNA3.1+HBV/P22 respectively and the cells were exposed to Act D and TNF alpha for 6h and then the induced apoptosis was detected by flow cytometry (FCM) and TUNEL technique. Supernatant HBeAg was detected by Abbott reagent. The intracellular expression of HBV/P22 protein was measured by Western blot and immunochemistry. In vivo, three cell groups were inoculated into nude mice by subcutaneous injections. After two weeks, Act D and TNF alpha were injected into the tumors and then the induced apoptosis in the tissues was detected by TUNEL technique. The expression of HBV/P22 protein in the tumor tissues was detected by immunochemistry.</p><p><b>RESULTS</b>In vitro, in HepG2- pcDNA3.1+HBV/P22 cells, supernatant HBeAg was positive and intracellular HBV/P22 protein was positively expressed. The apoptosis proportion of HepG2-pCDNA3.1+HBV/P22 cells was markedly lower than HepG2 and HepG2-pcDNA3.1+ cells (P < 0.05). In vivo, HBV/P22 protein was expressed in the tumor tissues, and the apoptosis proportion in the group injected with HepG2-pcDNA3.1+HBV/P22 cells was markedly lower than those injected with HepG2 and HepG2-pcDNA3.1+cells (P < 0.05).</p><p><b>CONCLUSION</b>HBV/P22 protein could inhibit the induced apoptosis of HepG2 cells both in vitro and in vivo.</p>

Preparation of VX2 rabbit hepatoma models and modification of the hepatic artery catheterization technique / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish New Zealand rabbit hepatoma models with VX2 cell line, and modify the hepatic artery catheterization technique.</p><p><b>METHODS</b>Forty New Zealand rabbit models bearing hepatoma were established by implanting VX2 cells into the left and right liver lobes. Two weeks after the tumor cell implantation, 26 rabbits in the experimental group underwent modified hepatic artery catheterization procedures using microsurgical technique, and 10 rabbits in the control group were catheterized with 3F micro-catheter using Seldinger technique. The VX2 hepatomas were observed before and after the catheterization with multi-slice spiral CT scan and digital subtractive angiography (DSA).</p><p><b>RESULTS</b>Tumor growth after the tumor cell implantation was confirmed in 36 rabbits by CT scans and open operations. The success rate of catheterization was 88% (23/26) in the experimental group, and 40% (4/10) in the control group. VX2 hepatomas appeared as hypointense or isointense nodules on multi-slice spiral CT, and hepatic artery angiography showed that VX2 hepatomas had homogeneous or nodular tumor staining.</p><p><b>CONCLUSION</b>The modified hepatic artery catheterization using microsurgical technique has higher success rate than catheterization with 3F micro-catheter by Seldinger technique, and significantly decreases X-ray exposure for the staff undertaking the operations.</p>

Relationship between hepatitis B virus genotypes and liver fibrosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the relationship between hepatitis B virus (HBV) genotypes and liver fibrosis.</p><p><b>METHODS</b>Polymerase chain reaction-restriction fragment length polymorphism method was employed to determine HBV genotypes in 298 HBV-related liver disease patients, including 73 with hepatocellular carcinoma, 53 with liver cirrhosis, 91 with chronic hepatitis B and 82 asymptomatic HBV carriers to analyze the relationship of HBV genotypes with serum fibrous indices and serum albumin and globulin (A/G) ratio.</p><p><b>RESULTS</b>B and C genotypes were dominant in patients with HBV-related hepatic diseases in Guangdong province. The levels of serum fibrous indices were significantly higher in patients with genotype C than in those with genotype B, and the former patients also had lower A/G ratio.</p><p><b>CONCLUSION</b>Patients with HBV genotype C may sustain more serious liver injury.</p>