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Ribosomal engineering is a technique that can improve the biosynthesis of secondary metabolites in the antibiotics-resistant mutants by attacking the bacterial RNA polymerase or ribosome units using the corresponding antibiotics. Ribosomal engineering can be used to discover and increase the production of valuable bioactive secondary metabolites from almost all actinomycetes strains regardless of their genetic accessibility. As a consequence, ribosomal engineering has been widely applied to genome mining and production optimization of secondary metabolites in actinomycetes. To date, more than a dozen of new molecules were discovered and production of approximately 30 secondary metabolites were enhanced using actinomycetes mutant strains generated by ribosomal engineering. This review summarized the mechanism, development, and protocol of ribosomal engineering, highlighting the application of ribosomal engineering in actinomycetes, with the aim to facilitate future development of ribosomal engineering and discovery of actinomycetes secondary metabolites.
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Actinobacteria/metabolismo , Actinomyces/genética , Antibacterianos/metabolismo , Família Multigênica , Ribossomos/genéticaRESUMO
Objective To explore the potential role of BK virus (BKV) in urothelial carcinoma after renal transplantation .Methods From May 2013 to March 2017 , We collected 26 cases of urothelial carcinoma after renal transplantation (study group) and 30 cases of urothelial carcinoma of non-immunosuppressed patients (control group) .Tumor tissues were stained with SV40 T antigen by immunohistochemical assay .Urinary and peripheral blood samples were assayed for BKV-DNA levels by real-time fluorescent quantitative polymerase chain reaction (PCR) .Results There were 7 positive cases of SV40 T-Ag in study group and only 1 weakly positive case in control group .The positive rate of BKV-DNA was 38 .5％ in urinary samples in study group (10 /26 ) and it was significantly higher than that in control group by 10％ (3/30)(P< 0 .05) .And the positive rate of blood BKV-DNA was not different between two groups ( P > 0 .05 ) .Conclusions There is a relatively high prevalence of BKV infection in urothelial carcinoma after renal transplantation .And a ,high level of BKV infection may play a role in urothelial carcinoma after renal transplantation .
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Objective To investigate the expression of human leucocyte antigen G (HLA-G) in urothelial carcinoma after renal transplantation,and to analyse the relationship between HLA-G expression and the various clinical and pathological parameters.Methods 29 patients with urothelium carcinoma after renal transplantation for the first time from January 2005 to June 2016 were selected as the experimental group,the age range was 32-70 years,with an average of (55.5 ± 8.1) years.29 non-transplanted patients with urothelial carcinoma as the control group 1,the age range was 36-74 years,with an average of (57.9 ± 8.2) years.15 cases of normal urinary tract epithelial were from cystoscopy biopsy as the control group 2.Immunohistochemical method was used to detect the difference of HLA-G expression between the three groups.The clinical and pathological data of patients with urothelial carcinoma after renal transplantation were analyzed.Results The expression rate of HLA-G was 79.3％ (23/32) in patients with urothelial carcinoma after renal transplantation,37.9％ (11/32) in non-transplanted group and 0 (0/15) in normal urinary tract epithelium group.The expression rate of HLA-G in non-transplanted group was significantly higher than that in normal urinary tract epithelium group (P ＜ 0.05).The expression rate of HLA-G in patients with urothelial carcinoma after renal transplantation was significantly higher than that in nontransplanted group and normal urinary tract epithelium group (P ＜ 0.05).Conclusions HLA-G is associated with the occurrence of urothelial carcinoma after renal transplantation.It may provide a new idea for the prevention and treatment of urinary tract epithelium after renal transplantation.
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Objective To investigate the expression of Notch4 protein and to analyze its correlation with the clinical parameters and the microvessel dentisty in renal cell carcinoma. Methods The expression of Notch4 was examined in 60 cases of renal cell carcinoma and the para-carcinoma tissue by SP immunohistochemical stain-ing ,and CD34 detection was used for counting microvessel density. Statistical analysis was performed to reveal the correlation with clinicopathological parameters ,microvessel density and prognosis. Results The positive rate of Notch4 protein expression was 75%(45/60)in para-carcinoma tissue,and was 43.3%(26/60)in renal cell car-cinoma,with significant difference on tumor grade and Lymph node metastasis(P<0.05). The microvessel densi-ty in Notch4 positive tissues was significant lower than that in the negative samples(P<0.05). The survival time of patients with Notch4 positive expression was significantly longer than that of patients with Notch4 negative expres-sion(P<0.05). Conclusion Notch4 protein plays an important role in the development of renal cell carcinoma. Notch4 expression might both attenuate the malignant biological characteristics and suppress the angiogenesis dur-ing tumor development.
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Objective To analyze the incidence and clinical features of urothelial tumors in renal allograft recipients.Methods A retrospective analysis of 1042 patients received renal allografts who had taken immunosuppression for at least six months between 2006 and 2011 in The First Centre Hospital of Tianjin was performed.Results Eleven cases of uroepithelial tumors were diagnosed in the 1042 cases of renal transplantation ( 1.06％ ),of whom 9 cases were noticed by hematuria ( 81.8 ％ ),2 cases ( 18.2％ ) by medical examination.Six patients were diagnosed with multifocal urothelial carcinomas.Surgery was performed on all the patients with renal tumors and followed by chemotherapy or radiotherapy.Conclusion Malignancies in urinary tract after renal transplantation should be bore in mind.Early diagnosis is very important.The treatment options include reducing immunosuppressive agents and removing tumor lesions completely.