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Biomedical subjects

B E Polotskiĭ

Publications and source records attributed to B E Polotskiĭ.

At least 19 recordsLinked to original sources
PubMed2003

[Inhibition of ABC-transporter(s)' function in non-small cell lung cancer cells by platinum drugs].

With an account of the literature data that platinum drugs react with many cellular targets, including ATP and proteins, the authors suggested that disturbance of the function of energy-dependent ABC-transporters (markers of multidrug resistance, MDR) under the effect of platinum drugs could be a cause of increased efficacy of MDR agents (agents, MDR to which is developed by the classical mechanism) when used in combination with platinum drugs even in the treatment of multidrug resistant lung cancer. The cisplatin and carboplatin effect on accumulation of MDR doxorubicin in cells of non-small cell cancer was studied by flow cytometry with the use of biopsy specimens. The MDR phenotype of the tumors was determined by a change in doxorubicin intracellular accumulation under the action of the ABC-transporter(s)' inhibitors: verapamil and genistein (specific inhibitors of Pgp and MRP respectively) and sodium azide (an inhibitor of all energy-dependent ABC-transporters). The MDR phenotypes, i.e. Pgp-MRP+ or Pgp+MRP+, were detected in all the tumors investigated. Two types of changes in doxorubicin intracellular accumulation under the action of the inhibitors and the platinum drugs were shown: (a) an increase in doxorubicin cytoplasmic accumulation and (b) a change in subcellular distribution of the anthracycline (increased accumulation of doxorubicin in the cell nucleus and its higher binding to DNA). Cisplatin and carboplatin had an inhibitory effect on ABC-transporter(s) in all the tumors investigated but the effect of carboplatin was less pronounced. It was concluded that cisplatin and carboplatin stimulation of doxorubicin intracellular accumulation, as well as a change in subcellular distribution of the anthracycline under the action of the platinum drugs (increased doxorubicin accumulation in the cell nucleus) in multidrug resistant lung tumors could be at least partly explained by inhibition of the MDR transporter(s)' function. The results could provide a basis for the use of the sequential combination cisplatin (or carboplatin)-->doxorubicin in the treatment of multidrug resistant lung cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2003

[Comparative assessment of the human cell viability ex vivo in Hanks solutions in distilled and Penta water].

Assessment of human colon and lung mucosa cell viability was performed in Hanks salt media prepared separately with distilled and patented Penta water. The cell viability in the suspension was estimated by fluorescence intensity of propidium iodide, a DNA specific dye, that is an indicator of DNA structure intactness or damage. The experiments were conducted with the flow cytometry technique. The histogram analysis showed that 2-hour incubation of the cells in Hanks salt medium prepared with distilled water resulted in an increase of the number of the apoptotic cells with a respective decrease of the number of the intact cells (approximately 2- and 4-fold in the suspensions of the colon and lung mucosa cells respectively). A similar experiment with Hanks salt medium prepared with Penta water resulted in a less marked increase of the viability of the apoptotic cells that did not exceed 20 and 50% for the colon and lung mucosa cells respectively. The findings showed that viability of the cells ex vivo was significantly higher when Penta water was used as a solvent for preparing Hanks salt media as compared to distilled water. The result is important for ex vivo experiments since maximum preservation of the DNA structure minimizes the number of possible experimental inaccurate and consequently erroneous conclusions. Furthermore, the fact of pathologic process inhibition in cells isolated from various human tissues in Penta-based salt media is in favour of using Penta water as a solvent for nutritional ingredients in ex vivo maintenance of human tissues for transplantation as compared to distilled water.

Cell Survival↗
PubMed1999

[EFR-like peptides and their receptors as prognostic factors for the survival of patients with non-small-cell lung cancer].

The levels of EGFR and its ligands have been assayed in tumor and adjacent lung tissues in NSCLC patients. Both EGFR and EGF-like peptides were found in tumor more frequently than in unaltered tissue. It was shown (Kaplan-Meyer) that simultaneous expression of EGFR and its ligands in tumor and adjacent lung tissues was associated with lower overall and relapse-free survival in NSCLC patients.

Adult↗
PubMed1998

[Epidermal growth factor receptors and their ligands in non-small-cell lung carcinoma].

Investigators and clinicians have recently called attention not only to the clinical and morphological parameters, but to the parameters characterizing the biological activity of nonsmall-cell carcinoma of the lung (NSCCL) from biochemical and molecular biological points of view. These include production of epidermal growth factor (EGF) receptors (EGFR) and their ligands which are important auto/paracrine regulation of lung tissue formation in health and tumor growth. Active studies of EGFR and EGF-like peptides (mainly, EGF and alpha-TGF) have failed to gain an insight into their role in the pathogenesis of NSCCL. Most authors suppose that tumor EGFR production increases as cell atypical features enhance and tumors show EGFR hyperexpression as compared with intact lung tissue. The expression of EGF and alpha-TGF is associated with poor prognosis in NSCCL. Attempts at designing and clinically testing the agents that block the transmission of EGFR ligands within the tumor cell are well-known, which open up new possibilities for antitumor therapy of patients with NSCCL.

Biomarkers, Tumor↗
PubMed1996

[Prognostic factors in the surgical treatment of lung cancer].

Some prognostic signs of surgical treatment of carcinoma of the lung are analysed. The stability and paramount importance of the integral clinical factor "extension of the tumor" is shown. The ultrastructural features of adenocarcinoma and squamous-cell carcinoma of the lungs influencing the disease prognosis were revealed. It is shown that electron microscopy allows differentiation of the tumor cells to be profoundly and precisely assessed. The results of the study unable a differentiated approach to the problems of postoperative therapy.

Adenocarcinoma↗
PubMed1995

[Germ cell tumors of the testis: current status and future progress].

The treatment of testicular cancer has undergone considerable evolution since the introduction of cisplatin and widespread recognition of its curative potentials at any stages of disease. This article provides an overview on statistical and epidemiological information, the latest developments in testicular cancer biology. Also, the results of treating 360 patients with nonseminomatous and 97 patients with seminomatous germ cell tumors are presented. A combined chemotherapy with cisplatin, etoposide and bleomycin demonstrates the highest rate of activity in nonseminomatous germ cell tumor patients. Surgical resection of residual masses after chemotherapy continues to be an important component of combined modality therapy in nonseminomatous testicular tumors. The needs for regular clinical examination during a follow-up have been underlined.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[Ultrastructure of pulmonary squamous cell carcinoma as a prognostic factor in surgical treatment].

163 operated on patients were divided into 2 groups: the 1st group--those surviving 5 years without recurrence (44.2%) and the 2nd group--those dying earlier from the tumour progression (55.8%). Central carcinoma was in 104, peripheral one in 59 cases. The number of dark cells (DC) and the degree of desmosome development revealed ultrastructurally have the greatest practical importance as the favourable course in the 1st group was associated with the absence or low number of DC (7%) and the high number of desmosomes (89%). These indices were found in the 2nd group in 86 and 41%, respectively. Both indices are of independent importance and are not associated with the spread of the carcinoma. The level of DC is of greater importance. Prognosis of the squamous cell carcinoma is the worse the higher is DC number in the tumour and the lower the desmosome number.

Carcinoma, Squamous Cell↗
PubMed1990

[Disorders in the sequence of regional metastasis and long-term results of the surgical treatment of complicated lung cancer].

To ascertain the frequency of disturbance of the stage character of regional metastasis in lung carcinoma complicated by disintegration or obstructive pneumonitis, and its influence on certain results of surgical treatment, the authors analysed the data on 175 patients who underwent lung resection. The stage character of regional lymphogenous metastasis was found to be disturbed in 61 (34.8%) patients, in 52 (85.2%) of them the main disease was complicated by obstructive pneumonitis. Five-year survival in the group of patients without disturbance of the stage character of metastasis was 28 +/- 4.8%, which was significantly greater than that in the group of patients with a disturbed stage character (15.5 +/- 5.2%).

Adult↗