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Objective To interpret the clinicopathological features and the key factors for diagnosis of polyomavirus-associated nephropathy (PVAN).Methods Clinicopathological data of 13casesof polyomavirus-associatednephropathyduring2008-2011inour hospitalwere retrospectively analyzed.Three cases received repeat biopsy.The clinicopathological features were analyzed according to thelight microscopicsceneandSV40-Timmunochemicalexpression.Results Recipients had a peak incidence of PVAN in 12 to 18 months period after renal transplantation,accompanied by elevated serum creatinine.Due to the progression of the disease,3patterns of histological findings could be identified.The early lesion was confined to the collected ducts,with slightly inflammatory infiltration in medullary interstitium,viral inclusions were not necessarily seen.The only findings could be enlarged nuclear and irregular arrangement of the tubular epithelial cells.At the developing stage,prominent tubulointerstitial nephritis was detected,and the involved tubules extended to other segments of renal tubule,even the parietal epithelial cells of Bowman's capsule could be compromised.The epithelial cells shed off,leading the tubular basement membrane exposed.Typical intra-nuclear inclusions as well as variable nuclear changes were found.At the end stage,the allograft showed notable chronic tubulointersititial change,with diffuse tubular atrophy and interstitial fibrosis.Although in this period,typical viral inclusions were rare, stillIHCshowedpositiveexpression of SV40-T. After immunosuppressantreductionor exchange,2 cases developed renal failure,4 cases showed sustained increment in serum creatinine,while 7 cases had a stabilized serum creatinine level.Conclusions Polyomavirus-associated nephropathy can display uneven pathological changes,as well as the morphology of the infected epithelial cells.Segments of the involved tubule are associated with the course of disease.Reduction of immunosuppressant at the early stage has a favorable effect.A prompt renal biopsy should be done in renal transplant recipient if who shows increased serum creatinine,and a routine polyomavirus immunohistochemical staining should be applied as well.
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BACKGROUND: The association of simian virus 40 (SV40) with certain types of human cancers, including malignant lymphomas, has been a topic of interest for some time. Although the virus is distributed worldwide, its incidences vary according to the specific types of tumors, and the epidemiological areas. The aim of this study was to investigate the frequency of SV40 in malignant lymphomas among Korean patients. METHODS: One hundred seventy three cases of malignant lymphomas were evaluated by immunohistochemical staining for SV40 large T antigen (TAg), using an extremely sensitive, tyramide based, catalyzed signal amplification method. RESULTS: From 158 non-Hodgkin's lymphomas, including 115 diffuse large B-cell lymphomas, and 15 Hodgkin's lymphomas, none of the cases were positive for SV40 TAg. CONCLUSIONS: SV40 does not appear to be related to the pathogenesis of malignant lymphomas among Koreans.
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Humans , Antigens, Polyomavirus Transforming , Antigens, Viral, Tumor , Hodgkin Disease , Incidence , Korea , Lymphoma , Lymphoma, B-Cell , Lymphoma, Non-Hodgkin , Simian virus 40 , VirusesABSTRACT
Objective To immortalize rat astrocytes which could be used as cell carriers for transgenic cellular analgesia. Methods Astrocytes were isolated from cerebral cortex of newborn SD rats by trypsin digestion and cultured according to the method of differential cell adhesiveness and transfected with plasmid pCMVSV40T/ PUR containing the simian virus 40 large tumor antigen (SV40Tag) gene. The positive colonies were isolated by puromycin selection and expanded by many passages. The integration and expression of large T antigen gene were detected and the immuno-reactivity of glial fibrillary acidic protein (GFAP) was determined by PCR, RT-PCR and immuno-cytochemistry. Results Rat astrocytes were successfully cultured in vitro and positively stained for the astrocytic marker GFAP. The positive colonies were isolated and subcultured for 50 passages. PCR and RT-PCR products were analyzed using 1.5% agarose gel electrophoresis. The size of amplifacation product of target gene was identical to that of the positive control (558 bp) . There was no PCR and RT-PCR product from non-transfected cells. DNA sequencing and BLAST showed that 558 bp nucleotides were identical to the SV40Tag gene of the Genbank (100%). The transfected cells were positively stained for the SV40Tag and GFAP. Conclusion Immortalized rat astrocyte strain with SV40 tag gene is constructed successfully.
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Objective To establish and identify tetracycline controlled gene inducible system in immortalized rat astrocyte strains. Methods The PT67 cells were transfected with pRevTet-On vector. The transfected cells were selected in medium containing G418. RT-PCR assay was used to confirm that Rev Tet-On virus was packed correctly. The viral titer was assayed by infecting NIH3T3 cells. The immortalized astrocyte was infected by RevTet-On virus and individual clones were selected. All individual clones were transiently transfected with pRev TRE-Luc, which carried luciferase gene. The clone with low background and high induction expression was selected and its inducibility was tested. Results The RT-PCR assay showed that RevTet-On virus was packed successfully. The highest viral titer of RevTet-On was 7.4?05 CFU/ml. Rev Tet-On infected immortalized astrocyte and 48 individual clones were isolated. Clone 6 was selected for its highest induction of the luciferase activity in response to doxycycline and the lowest leakiness (activity in the absence of doxycycline) and its inducible fold was 20.6. The expression of luciferase was induced in a dose-dependent manner by doxycycline at the concentrations between 100 and 2 000 ng@ml-1. The expression of luciferase began 1h after doxycycline administration (1000 ng?ml-1) and reached the maximum level 48 h later. Conclusion The tetracycline controlled inducible system is established successfully in immortalized rat astrocyte strains, which is useful for the study of control exogenous gene expression.
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Objective To study the biological character of rat astrocyte strain immortalized by simian virus 40 large T antigen gene(SV40Tag) and explore the feasibility of using it as cell vehicle for transgenic cellular analgesia.Methods Rat cerebral cortical astrocytes (AST) and immortalized rat astrocyte strain (IAST) were cultured in vitro. Morphology and growth features of AST and IAST were examined and compared after subculture, freezing and recovery. The ultrastructure of the cells was observed by transmission electron microscopy. The glial fibrillary acidic protein (GFAP) in these cells was detected by immuno-cytochemistry. The cell proliferation rate and cell cycle were determined by bromodeoxyuridine labelling and flow cytometry. AST and IAST were cultured in soft agar and inoculated in nude mice to investigate the tumorigenesis of IAST. Results LAST could be subcultured successively. The cells remained monolayer, anchorage dependent and the growth was attachment-inhibited. When AST was subcultured for only 10 passages, replicative senescense began. Subculture, freezing and recovery did not influence the shape and proliferation of IAST (94%?5%) , but decreased the vitality rate of AST (54%?4% ) (P