Objective To investigate the genetic mutation of the norA gene and its promotor from the wild-type drug-resistance Staphylococeus aureus(S.aureus)strains. Methods A total of 10 antibiotic-resistant S.aureus strains were isolated and screened from the burn wound for the sequencing and analysis of the nora gene and its promoter. Results There isolated 87 S.aureus strains from the burn wound flora,which were completely sensitive to vacomycin,highly sensitive to Quinupristin and Nitrofurantoin,but highly resistant to the other antibiotics,even up to91.7% of MRSA.There found the same point mutation(G→A) located at 1 349 sites of the norA gene coding region in all the S.aureus strains,saying that the amino acid was changed from Gly(glycin)to Asp(agpartic acid) in 291 sites.The resetpine reverse test showed that the MICs value of three antibiotics was lowered at various degrees in all 10strains.Conclusion NorA gene mutation is one of the mechanisms for antibiotic-resistance of S.aureus.

Anemia, Hemolytic, Congenital ; etiology ; Female ; Hepatitis ; complications ; Humans ; Infant ; Syndrome

Objective To explore the relationship between cough variant asthma (CVA) and mycoplasma pneumoniae (MP) infection.Methods Fifty children with CVA were chosen as the experimental group at random,and 50 children with acute upper respiratory infection,who went to the hospital in the same time and with similar age,were chosen as control group.The MP-IgM of children in both groups were tested by the granule agglutinating method.Results Significant difference (? 2=9.013 P

Objective To summarize the clinical features,neuroimaging findings and pathological characteristics of demyelinating pseudotumors(DPT)of the brain,and to differentiate it from glioma. Methods The clinical features,neuroimaging findings and pathological characteristics of 35 patients with demyelinating pseudotumors of the brain were summarized,and the diagnosis for 18 of them was confirmed by bioscopy.Results Demyelinating pseudotumors affected adults of both sexes.The onset age of patients ranged from 9 to 69 years old.There was no definite antecedent,and the clinical syndromes were atypical. Neuroimaging scans showed multiple lesions in cerebral hemisphere,while the lesion in brain stem and spinal cord was single.The symptom and neuroimaging were not parallel.While with many or large lesions, the symptoms and signs were less.The lesions were not enhanced on CT scan,but appeared round or patch enhancement on MRI scan.Nine patients with DWI all appeared high density.The myelin basic protein was useful for diagnosis.The typical pathological changes were demyelination,perivascular inflammatory infiltration and reactive gliosis.The Creutzfeuldt cells were also found in these patients.The lesions might become small or disappear after treatment,but could not serve as the criterion to exclude brain neoplasm. Conclusions DPT is a distinct demyelination disease entity,which is confusable with brain neoplasm.It is difficult to distinguish DPT from brain neoplasm with the clinical features and conventional neuroimaging scan.But DWI scan is useful.The pathological changes accord with demyelination,and Creutzfeuldt cells are also found.It is important to apply corticosteroid treatment or biopsy rather than being anxious to excise the lesions.

Connexin-43 (Cx43) expression in prostate cancer (PCa) cells and the potency of gap junctional intercellular communication (GJIC) in the cells were investigated, with an attempt to elucidate the reason why the so-called "bystander effect" mediated by thymidine kinase (TK) suicide gene therapy on PCa cells is not of significance and to explore the role of GJIC in PCa carcinogenesis. mRNA and protein expression of Cx43 in a PCa cell line PC-3m was detected by reverse-transcription polymerase chain reaction (RT-PCR) and strapt-avidin-biotin-enzyme complex (SABC) immunohistochemical staining, and inherent GJIC of PC-3m cells was assayed by scrape-loading and dye transfer (SLDT) assay. The expression of Cx43 in human normal and malignant prostate tissues was determined by SABC immunohistochemistry as well. It was found that Cx43 mRNA and protein expression in PC-3m cells was slightly reduced as compared with positive controls and the location of Cx43 protein was aberrant in cytoplasm rather than on membrane. Assessment of paraffin sections demonstrated that the expression of Cx43 protein in PCa cells was abnormally located and markedly diminished as compared with normal prostatic epithelial ones, displaying a negative correlation to the pathological grade (chi2=4.025, P<0.05). Additionally, capacity of inherent GJIC in PC-3m cells was disrupted, which was semi-quantified as (+) or (-). It was indicated that both down-regulated expression of Cx43 mRNA and aberrant location of Cx43 protein participated in the mechanisms leading to deficient GJIC in PC-3m cells. Lack of efficient GJIC is a molecular event, which may contribute not only to limited extent of "bystander effect", but also to initiation and progression of prostatic neoplasm.

AIM:To study the feasibility of recombinant adeno-associated virus(rAAV)as a vector to transfer the green fluorescent protein(GFP)gene as a target gene into rabbit retina.METHODS:Intravitreal injection of rAAV-gfp was performed in either eye for each rabbit with the other eye taken as control.At the 3rd,7th,and 14th day after injection,the eyeballs were removed,and the retinas were flat-mounted on glass slides to inspect the retinal fluorescence,respectively.RESULTS:After intravitreal injection of rAAV-gfp,the presence of fluorescent spots in the cytoplasm of retinal cells indicated that GFP gene was efficiently transferred and expressed in the rabbit retina.CONCLUSION:Recombinant adeno-associated virus is a reliable and simple vector for transferring target gene,e.g.,GFP gene,to the retina.

The killing effects of herpes simplex virus thymidine kinase gene/ganciclovir (HSV-tk/GCV) approach by the addition of several commonly clinical chemotherapeutic agents on hormone refractory prostate cancer (HRPC) cells PC-3m were investigated. After transferring of the HSV-tk gene into PC-3m cells, mRNA and protein expression of HSV-tk was detected by reverse-transcript polymerase chain reaction (RT-PCR) and strept avidin-biotin complex (SABC) immunohistochemical method. The killing effect of GCV, cisplatin (CDDP), etoposide (VP-16), vincristine (VCR), methotrexate (MTX), 5-fluorouracil (5-Fu), and suramin on PC-3m cells was evaluated by morphological assessment analysis, trypan blue exclusion assay and MTT assay respectively. Additionally, the cooperative effect of HSV-tk/GCV system combined with the above agents on the target cancer cells was determined by MTT. Furthermore, apoptosis and necrosis induced by GCV plus 5-Fu or suramin was analyzed by flow cytometry (FCM). The results showed that that there was HSV-tk mRNA and protein expression in pDR2-tk plasmid transduced PC-3m cell. Combination of GCV with VP-16, VCR, 5-Fu or suramin led to an enhanced cellular killing effect, but with CDDP resulted in a reduced one and with MTX in an approximate one. FCM revealed that synergistic use of GCV and 5-fu or suramin resulted in a rather large proportion of apoptosis and necrosis with the apoptosis index being 36.38% and 35.51%, and the proportion of necrosis being 33.05% and 28.87%, respectively. In conclusion, HSV-tk/CGV approach by addition of certain clinical available chemotherapeutic drugs brings on statistically significant enhanced cell killing over single-agent treatment. Our results highlight the potential for such new combination therapies for future treatments of HRPC.

Some studies indicate that adipose derived stem cells (ADSCs) can differentiate into adipogenic, chondrogenic, myogenic, and osteogenic cells in vitro. However, whether ADSCs can be induced to differentiate into neural cells in vitro has not been clearly demonstrated. In this study, the ADSCs isolated from the murine adipose tissue were cultured and transfected with the EGFP gene, and then the cells were induced for neural differentiation. The morphology of those ADSCs began to change within two days which developed into characteristics of round cell bodies with several branching extensions, concomitantly expressing EGFP fluorescence. Approximately 60% of the total cell populations were bipolar or multipolar in shape. Some of them appeared to make contact with their neighboring cells. RT-PCR, Western blot and Immunocytochemistry revealed that the expression levels of the markers of neurons and oligodendrocytes such as MAP2, NF-70, Neu N and RIP upon neural induction were increased, but the expression of the special marker of astrocytes, GFAP, was undetectable until 96 h after induction when a small signal was observed. It was concluded that the ADSCs transfected with EGFP possessed the ability to undergo morphologic and phenotypic changes consistent with neural differentiation in vitro. It suggests that these cells might provide an ideal source for further stem cell research with possible therapeutic application for spinal cord injury.

The cancer stem cells (CSCs) from human osteosarcoma by serum-free three-dimensional culture combined with anticancer drugs were isolated and identified. The primary cells derived from human osteosarcoma were digested by trypsin to prepare a single-cell suspension, and mixed homogeneously into 1.2% alginate gel. Single-cell alginate gel was cultured with serum-free DMEM/F12 medium. Epirubicin (0.8 mug/mL) was added to the medium to enrich CSCs. After cultured conventionally for 7 to 10 days, most of cells suspended in alginate gel were killed by epirubicin. But few cells survived and some single-cell cloning spheres formed. Immunofluorescent staining for Oct3/4 and Nanog was implemented to find cells with properties of self-renewal and multi-potential differentiation. Cells from cloning spheres were transplanted into BALB/c mice to detect the tumorigenicity in vivo. The results showed that some cells positive for Oct3/4 (TRITC) and Nanog (TRITC) were found in single-cell cloning spheres, and most of positive cells were concentrated in the core of sphere. Cells from spheres could form osteosarcoma in the body of mice. It was concluded that cells from single-cell cloning spheres had the properties of the expression of parts of stem cell genes (Oct3/4 and Nanog), resisting anti-cancer drugs, and tumorigenicity in vivo. To sum up, it is believed that cells obtained from osteosarcoma by serum-free three-dimensional culture combined with anticancer drugs are cancer stem cells.