OBJECTIVE To investigate the distribution and resistance of commonly encountered pathogens in a General Hospital,and provide reference for antimicrobial agents usage.METHODS All pathogenic bacteria were isolated from the clinical specimens during the last four years and samples were identified.K-B method was performed to test the antibiotic resistance.RESULTS Among 1643 isolates,The Gram-negative bacteria Pseudomonas aeruginosaand Escherichia coli,and the Gram-positive bacteria Staphyococcus epidermidisand S.aureus were the main pathogens.The P.aeruginosa was highly resistant to broad-spectrum penicillins,third-generation cephalosprins,aminoglycosides and quinolones.But impenem showed activity against Gram-negative bacilli,with resistant rates less than

OBJECTIVE: To investigate the changes of ultrastructure of biliary epithelia with ischemic-type biliary lesion (ITBL) and the protection effect of exogenous growth hormone (GH) in order to provide experimental information for prevention of biliary complication after liver transplantation. METHODS: Rats underwent liver transplantation were randomized into control group, ITBL group and recombinant human growth hormone (rhGH) group (n=6, respectively). Each group was given drugs at the same day postoperation. 7 days later, the specimen of bile ducts was collected. The epithelial changes of biliary tract were observed with TEM, and the injury degree of the epithelia was analyzed quantitatively in a specialized image analysis system. The epithelial plane measurement parameters of each group were measured, including the density of area and quantity of epithelia, and the density of area of epithelial microvilli. RESULTS: As compared with control group, in ITBL group the integrity of bile ducts was destroyed, epithelial microvilli became sparse, the epithelial plane measurement parameters were significantly decreased (P

Objective To explore the effects of adriamycin-loaded immuno-nanoparticles on multidrug resistance (MDR) of hepatoma cell line SMMC-7721/ADM. Methods The cytotoxicity of the adriamycin-loaded immuno-nanoparticles on the bepatoma cell line SMMC-7721/ADM in vitro and the tumor cell-binding ability of adriamycin-loaded immuno-nanoparticles were detected. Results The effect of the cytotoxicity of adriamycin-loaded immuno-nanoparticles on the hepatoma cell line SMMC-7721/ADM was significantly better than that of adriamycin-loaded nanoparticles. Adriamycin-loaded immuno-nanoparticles had the specific binding ability with the hepatoma cell line SMMC-7721/ADM. Conclusions Adriamycin-loaded immuno-nanoparticles can overcome the MDR of the tumor in vitro. The mechanism may be that immuno-nanoparticles could adhere to the tumor cell membrane, and the release of the loaded adriamycin creates a high local concentration in the extracellular medium. The increased concentration gradient improves the diffusion of adriamycin from the extracellular medium to the intracellular medium.

Objective:To investigate the influence of miR-7 knock down on the development of CD 4+SP cells in the thymus in mice,and preliminary explore its possible mechanism.Methods:The changes of volume ,weight and total cell counts of thymus in miR-7 knock down (miR-7KD) mice were observed compared with Wild-type(WT)mice;the pathological changes of thymus were observed by HE staining.FACS analysis was performed on the proportion ,as well as the expression level of CD44 and CD62L,of thymus CD4+single positive (SP) cells.Meanwhile,the proliferation percentage of CD4+SP cells was measured by Ki-67 staining.The apoptosis percentage of CD4+SP cells was analyzed by FACS.The changes on the transduction of ERK 1/2 pathways were determined by Western blot.Results:Compared with WT mice ,the size,weight and total cell number of thymus were marked reduced in miR-7KD mice( P<0.05 );moreover ,pathological change also was presented.The proportion and total cell number of thymus CD 4+SP cells were marked decreased ( P<0.05 ).Furthermore ,the expression level of CD 44 and proliferation percentage ,as well as apoptosis percentage ,of CD4+SP cells were obviously increased (P<0.05),however,the expression level of CD62L of CD4+SP cells were decreased (P<0.05). Finally,the level of total ERK1/2 and phosphor-ERK1/2 was decreased obviously ( P<0.05 ).Conclusion: miR-7 knock down can affect the development of CD 4+SP cells in the thymus , which might be closely related to the cell activation state and altered the transduction of ERK1/2 pathways.

Objective: To describe the molecular epidemiological characteristics of norovirus gastroenteritis outbreaks in Zhuhai from 2011 to 2016. Methods: Anal swab specimens were collected from 576 cases with 56 outbreaks of acute norovirus gastroenteritis from 2011 to 2016. Specimens were tested by real-time RT-PCR. Three to four of norovirus positive specimens were selected from every outbreak to amplify the VP1 gene by RT-PCR and one strain was chosen randomly from every outbreaks to determine the genotype by phylogenetic tree analysis. Results: Eight genotypes were identified from 56 outbreaks and all of them belonged to GⅡ genogroup. The genotype of norovirus strain changed with prevalence time. The GⅡ.4/2006b was dominant from 2011 to 2012, and replaced by GⅡ.4/Sydney _2012 during the 2012—2013 norovirus season, and both of them never appeared after Feb. 2013. GⅡ.17 was the only genotype during the 2014—2015 norovirus season. All the 7 outbreaks occurred from 2015 to 2016 were caused by GⅡ.3 norovirus. The GⅡ.17and GⅡ.3 were identified from Apr. to Sep. 2016; GⅡ.p16-GⅡ.2 were the only genotype in 12 outbreaks from Nov. to Dec. 2016. The GⅠ genogrope was never identified from 2011 to 2016 in Zhuhai. Conclusions The Norovirus GⅡ was the only pathogeny which caused the outbreaks of norovirus gastroenteritis. The recombinant norovirus strain GⅡ.p16-GⅡ.2 emerged and caused large outbreaks in the last two months of 2016 in Zhuhai; several recombinant strains of the GⅡ.p16 RdRp gene were found now, which suggests that attention should be focused on the prevalence and evolution of the recombinant norovirus.

Objective:To analyze the prevalence and genotypes of human pegivirus-1 (HPgV-1) among HIV-1-infected men who have sex with men (MSM) in Zhuhai, aiming to elucidate the impact of HPgV-1 on the progression of AIDS.Methods:This study collected 934 serum specimens positive for antibodies against HIV-1 for viral RNA extraction from MSM in Zhuhai from 2012 to 2020. HPgV-1 5′UTR was amplified by nested PCR and then E gene was amplified by nested PCR and sequenced in the 5′UTR-positive specimens. A phylogenetic tree was constructed to analyze genotype distribution. The influence of HPgV-1 infection on the progression of AIDS was evaluated through analyzing HIV-1 viral load and CD4 + cell counts in patients in the early stage of AIDS before antiviral treatment. Results:The positive rate of HPgV-1 in MSM with HIV-1 infection in Zhuhai was 31.05%. A total of 273 valid sequences were obtained after amplification. The main genotype of HPgV-1 was G3 (252, 92.31%), which was highly homologous to the epidemic strains in China and Japan in recent years, followed G2 (21, 7.69%), which was highly homologous to the epidemic strains in France and America. HPgV-1 strains of G1, G4, G5, G6 and G7 genotypes were not detected. There was no significant difference in HIV-1 virus load or CD4 + cell counts between patients with HIV-1 infection alone and those with HIV-1 and HPgV-1 (G3 or G2 genotype) co-infection. Conclusions:According to the data of this study, HPgV-1 infection could not delay the progression of AIDS in MSM in the early stage of AIDS before antiviral therapy. The widespread HPgV-1 of G3 genotype in China did not have a significant impact on the progression of AIDS. Therefore, a systematic in-depth research on various genotypes of HPgV-1 and further study on the pathogenic mechanism of HPgV-1, especially in patients with HPgV-1 and HIV co-infection, were needed to understanding the interaction mechanism between different genotypes of HPgV-1 and HIV-1.

Guided bone regeneration technology applied in alveolar bone defect regeneration is based on the barrier function and space maintenance of the barrier membrane. Therefore, traditional development strategies for barrier membranes focus on their physical barrier function, degradation characteristics and biocompatibility to avoid immunogenicity. However, not only does the barrier membrane passively block connective tissue, it is recognized as a “foreign body”that triggers a persistent host immune response, known as a foreign body reaction. The theories of osteoimmunology reveal a close relationship between the immune system and bone system and emphasize the role of immune cells in bone tissue-related pathophysiological processes. Based on these findings, we propose a novel development strategy for barrier membranes based on immune microenvironment regulation: by manipulating mechanical properties, surface properties and physiochemical properties, barrier membranes are endowed with an improved immunomodulation ability, which helps to regulate immune cell reactions to induce a favorable local immune microenvironment, thus coordinating osteogenesis and osteoclastogenesis as well as barrier membrane degradation to increase the efficiency of barrier membranes in GBR applications. In this paper, we review the development of barrier membranes and their close relationship to the immune microenvironment concerning bone regeneration and membrane degradation. Additionally, the outcomes of research on barrier membranes based on the regulation of the immune microenvironment have been summarized to improve the osteogenesis efficiency of barrier membranes and solve the problem of the regeneration and repair of bone defects, especially alveolar bone defects.