Biomedical subjects
Publications and source records attributed to M A Ivanov.
The authors made an analysis of the nearest and long-term results of treatment of 139 patients subjected to right-sided hemicolectomy with different variants of ileotransversoanastomoses. Best results were obtained after end-to-end enterocolostomy.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The authors have analyzed literature data of 303 cases of adrenal cysts and describe their two cases (both patients were operated on with good results). Problems of diagnosis and treatment of this rare disease are discussed.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
BACKGROUND: Aberration in the pattern of DNA methylation is one of the hallmarks of cancer. We present data suggesting that dysregulation of MBD2, a recently characterized member of a novel family of methylated DNA binding proteins, is involved in tumorigenesis. Two functions were ascribed to MBD2, DNA demethylase activity and repression of methylated genes. METHODS: Multiple antisense expression and delivery systems, transfection, electrotransfer and adenoviral were employed to demonstrate that MBD2 is essential in tumorigenesis, both ex vivo and in vivo. RESULTS: Inhibition of MBD2 by antisense expression resulted in inhibition of anchorage-independent growth of antisense transfected cancer cells or cells infected with an adenoviral vector expressing MBD2 antisense. Xenograft tumors treated with an adenoviral vector expressing MBD2 antisense or xenografts treated with electrotransferred plasmids expressing MBD2 antisense showed reduced growth. CONCLUSIONS: These results support the hypothesis that one or both of the functions described for MBD2 are critical in tumorigenesis and that MBD2 is a potential anticancer target.
BACKGROUND: The "tet switch system" was originally described under the tet-off configuration with its components encoded by two separate plasmids. Since then, many virus vectors harbouring tet-off components have been designed and their regulation by tetracycline is widely reported. On the contrary, tet-on regulation by viral vectors is poorly documented. METHODS: E1-E4-defective adenoviruses harbouring either rtTA or the luciferase gene under a minimal inducible promoter (TK* or CMV*) or both components in a single genome were produced. Using either a double or a single virus strategy, induction of luciferase expression was investigated in various cell lines, in mice muscle and in rat brain. RESULTS: Over 400-fold induction can be reached with PC12 and NHA cells using a double virus strategy. Comparison of the background activity of different minimal inducible promoters revealed a significant difference between TK* and CMV* promoters both with the cell culture and the in vivo experiments. Interestingly, a single virus strategy permitted an induction exceeding 600-fold with human astrocyte primary cells. Moreover, the E1-E4-defective adenovirus-mediated tet-on system can be quickly switched off and turned back on again. Depending on the cell line, the level of rtTA derived by the single virus strategy differed, resulting in different efficiencies. Experiments performed in rat striatum and mouse muscle confirmed the importance of rtTA expression and minimal promoter used on both doxycycline-independent expression and induction efficiency. Under appropriated rtTA expression, a 32-fold induction is observed in mouse muscle. CONCLUSIONS: In the recombinant adenovirus context, the CMV* but not the TK* promoter is sensitive to transcriptional interference resulting in high doxycycline-independent expression. By paying attention to the rtTA expression, moderate and high induction can be obtained in vivo and in vitro accordingly.
After the transfection of the gene Bax into the cultured tumor cells of human ovary adenocarcinoma SKOV3 and uterus carcinoma HeLa in vitro the high sensitivity of the cells SKOV3 to the protein Bax produced after the gene Bax transfection was found. The sensitivity of the cells HeLa to the gene Bax transfection was much smaller. The hyperexpression of gene Bax and hypersensitivity to doxorubicin were seen in HeLa cells received as a result of the gene Bax transfection and subsequent selection. All cells of the line SKOV3 with the increased expression of the transfected gene Bax died. In the cell line SKOV3 the mutation in a gene Bax was found which has a genotype G7/G9 against a native type of a gene Bax--G8/G8. It was concluded that the found in the exone 3 of the gene Bax mutation G7/G9 in cells SKOV3 results in an inactivation of proapoptotic activity of the protein Bax.
A technique of prolonged sympathetic ganglion blockage with an epidurally applied ganglioblocker pentamine has been suggested. With the help of manometry, using an open catheter and electromyography methods, the effect of the above technique on the recovery of the damaged small intestinal functions in the early postoperative period has been studied in comparison with prolonged epidural blockade with trimecaine in patients after gastric surgery. The effect of epidurally administered drugs on central hemodynamics has been studied. The technique suggested is effective for the recovery of the damaged small intestinal functions and has a number of advantages over conventional prolonged epidural blockade: less pronounced effect on central hemodynamics, the absence of blocking effect on afferent pulsation. All these makes it a technique of choice in patients with severe homeostasis disturbances and low central hemodynamic indexes.