Biomedical subjects

A M Shcherbakov

Publications and source records attributed to A M Shcherbakov.

At least 19 recordsLinked to original sources

PubMed2006

Sensitization of MCF-7 breast cancer cells to the apoptotic effect of estradiol.

A new substrain of hormone-resistant MCF-7/T breast cancer cells was selected after long-term culturing of estrogen-dependent MCF-7 cells in the presence of tamoxifen. These cells were resistant to the growth-stimulating and cytostatic effects of estradiol and tamoxifen, respectively. MCF-7/T cells gained paradoxical sensitivity to the apoptotic effect of estradiol. Estradiol stimulated p53 expression and decreased DNA-binding activity of NF-kappaB. Our findings provide indirect evidence that these proteins are involved in the regulation of estrogen-induced apoptosis. These results indicate that tamoxifen-resistant breast cancer cells can be sensitized to the apoptotic effect of estradiol. The data form a basis for the development of new methods of endocrine therapy for breast cancer patients.

Antineoplastic Agents↗

PubMed2006

[Combined radiotherapy for inoperable esophageal cancer].

Among 112 patients with inoperable esophageal cancer treated with high-dose intraluminal brachytherapy and distant irradiation, objective response was in 84.8%. Predominantly local complications were reported in 78.6%. Recurrences were detected in 63.5% during follow-up, with mean relapse-free period being 107 days. Mean survival time was 15.3 months (1-, 2- and 3-year survival--58.8; 22.3 and 12.9%, respectively) which was comparable to similar results of palliative esophagectomy for gastric cancer.

Aged↗

PubMed2006

[Use of endoscopic surgery and combined radiotherapy for inoperable cancer of the esophagus].

A comparative evaluation of the efficacy of combined radiotherapy (112 - group 1) carried out in conjunction with a battery of procedures of endoscopic surgery plus combined radiotherapy (76 - group 2) for inoperable cancer of the esophagus was conducted in 118 patients. Maximum local regression was reported in group 2 (77.6%) as compared with only 33.9% in group 1. Relatively longer relapse-free period (133 days) and lower residual growth incidence (44.6%) were in group 2, too, as compared with 107 days and 63.5% in group 1. Mean survival duration was nearly identical in both groups - ca.15 months. Similarly, survival rates in groups 2 and 1 were: 69.2 and 58.8% (year 1), 22.2 and 22.3% (year 2), and 11.3 and 12.9% (year 3), respectively. It was concluded that combinations of endoscopic surgery and combined radiotherapy for inoperable cancer of the esophagus improved immediate results and reduced the rates of residual tumor incidence. However, no significant differences in mean duration or rates of survival were observed.

Combined Modality Therapy↗

PubMed2005

Activated proteinkinase B in breast cancer.

The content of activated (phosphorylated) form of proteinkinase B in tumors and homologous tissues of 46 patients with breast cancer was measured by enzyme immunoassay. Activity of proteinkinase B was increased in tumors of 48% patients in comparison with homologous histologically unchanged tissue. Activity of proteinkinase B in hormone-dependent mammary tumors was significantly higher than in tumor tissue from patients with negative receptor status.

Adult↗

PubMed2005

[Vascular endothelial growth factor and two types of its receptors in breast cancer].

Levels of VEGF, VEGFR-1 and VEGFR-2 were determined by enzyme immunoassay in tumor and adjacent normal tissue samples from 39 breast cancer patients. Those parameters were significantly higher in tumor tissue. Direct correlations were established between VEGF and VEGFR-1, on the one hand, and VEGF and VEGFR-2, on the other. VEGF expression in breast tumor was relatively higher at earlier stages of tumor growth. VEGF and VEGFR-1 expression was consistently higher in progesterone receptor negative tumors.

Adult↗

PubMed2005

[Endoscopic possibilities in the palliative treatment of cardial gastroesophageal cancer].

Endoscopic surgery including chemical necrolysis, diathermy coagulation and excision, and argon-plasma was conducted in the course of two-stage palliative treatment of 31 patients with gastroesophageal cancer. A total of 273 procedures of tumor destruction were administered. Stenosis was either eliminated or significantly reduced in 28 (90.2%) on completion of stage I. Average stabilization duration was 44 days. During stage II, periodic destruction of tumor foci continued so that peroral feeding could be maintained for another 3 years. Mean survival was 8.7 months (one year--35%, two--20%, three--7.7%). Since no life-threatening complications were reported, our method may be recommended for out-patient hospital applications.

Aged↗

PubMed2005

[Results of endoscopic recanalization for inoperable cancer of the esophagus].

Patients with inoperable cancer of the esophagus were followed up for 1-3 years after a course of palliative endoscopic destruction of tumor. Residual growth occurred in 88.1% with an average stabilization period of 47 days. Among the unfavorable prognostic factors were partial decomposition of tumor, squamous-cell pattern, size of more than 9 cm, circular extension through the esophagus and stage III stenosis. With the aid of newly-developed methods of outpatient endoscopic destruction, 94.2% could eat throughout their survival period. Mean survival time was 5.6 months or 7.3 months in metastasis-free cases.

Adult↗

PubMed2005

[An experience with clinical endoscopy and argon-plasma coagulation for removal of large bowel polyps].

Fifty-one loop polypectomies assisted by argon-plasma coagulation were performed in 40 patients, aged 18-85. Polyps presented as sitting on a wide pedicle (25), sprawling (19) or spreading flat (7) in rectum (24), sigmoid (18) or colon (9). Polyp diameter ranged 1.0-1.9 cm (12 adenomas), 2-2.9 (18) or 3-5 cm (21). Coagulation was carried out immediately after partial removal of polyp with the aid of diathermic loop. Endoscopic follow-up and biopsy were conducted after 1, 3, 6 and 12 months. Complete destruction of adenomas was achieved by 1-6 coagulations (mean - 1.4) performed at an interval of 3-4 weeks. During follow-up (6-24 months), out of 40 patients with 51 polyps, histologically identifiable villous adenoma was detected in 3 (during 12 months). The latter underwent repeat argon-plasma coagulation. That technique proved more effective and safer than traditional methods in dealing with large polyps of the large bowel having a wide pedicle and/or sprawling.

Adenomatous Polyposis Coli↗

PubMed2005

[Endoscopic argon-plasma coagulation and combined radiotherapy for short (up to 3 cm) esophageal cancers].

The immediate and 3-year results were evaluated of application of combined radiotherapy and/or endoscopic argon-plasma coagulation carried out for esophageal cancers 3 cm long or less in 39 patients. Recurrences were reported, in 31.4% ca. 4 months later. Joint use of the modalities was followed by an up to 5-months rise in relapse-free period. Mean survival time was 20.2 months, and it was significantly higher in radiation-treated patients without metastases. One-year survival was 96.6% in those without distant metastases, 2-year--72%, and 3-year--47.6%. Our data point to new vistas in application of our techniques, particularly, for short (up to 3 cm) inoperable esophageal cancers.

Adult↗

PubMed2004

[Study of the antioxidant drug "Karinat" in patients with chronic atrophic gastritis].

A randomized double blind placebo-controlled trial of the drug karinat was carried out in patients with chronic multifocal atrophic gastritis. Karinat contains beta-carotene 2.5 mg, alpha-tocopherol 5 mg, ascorbic acid 30 mg and garlic powder 150 mg per tablet. Out of 66 patients, 34 received karinat, 32--placebo. Both karinat and placebo were administered for 6 months, one tablet twice a day. Karinat therapy improved digestion, the fibrogastroscopic pattern of mucosa, inhibited Helicobacter pylori infection, stimulated stomach activity, mitigated intestinal metaplasia and interfered with the epithelial proliferation of gastric mucosa. These therapeutic effects were more pronounced in the study group. On the whole, the effectiveness of the drug was significantly higher (29%). Karinat should be recommended for the management of chronic atrophic gastritis, a precursor of stomach cancer.

Anticarcinogenic Agents↗

PubMed2004

[An experience with argon-plasma coagulation in endoscopic management of obstructive tumors of the trachea and main bronchi].

Endoscopic management of obstructive tumors of the trachea and main bronchi was carried out using argon-plasma coagulation in 39 patients aged 15-75. Thirty four patients had primary malignancies, 2--secondary tumors and 1- metastasis to the lung. Two patients with benign tumors were cured completely. Lobar bronchus lesions involving the extrapulmonary bronchus were identified in 28 patients; involvement of both main bronchi and trachea--5, intermediate bronchus lesions--3, and involvement of one lobar bronchus--3. Stenosis was complete in most patients and full or partial lumen was restored in all of them. Follow-up checks were conducted at 2-, 4- and 12-week intervals under outpatient conditions. Bleeding from the bronchial arteries broke out in 1 patient during examination and was aborted. Our method may be used in emergency to manage tumor-induced obstruction of the trachea and main bronchi, to raise the quality of life in incurable cases and to improve the results of chemoradiotherapy.

Adolescent↗

PubMed2004

[Intraluminal endoscopic surgery in prevention and palliation of dysphagia induced by esophageal cancer (methods, technique and immediate results)].

A procedure of argon-plasma coagulation is suggested to be used alone or in conjunction with chemical necrolysis and high-frequency electrosurgery for endoscopic palliation of dysphagia. Its outstanding impact on tumor-induced dysphagia, involving no life-threatening complications, was demonstrated in a group of 97 patients. A number of basic factors immediately influencing the results of therapy are outlined and relevant recommendations on clinical use are provided.

Adenocarcinoma↗

PubMed2004

[The molecular mechanism responsible for the adaptation of malignant tumors to hormonal drugs: a role of phophatidylinositol-3-kinase and phosphoinositide-dependent proteins].

Phophatidylinositol-3-kinase (PI3K) is a major intracellular protein that is responsible for the transmission of an antiapoptotic signal and controls the survival of tumor cells upon exposure to damaging agents. Experiments using different tumor cell cultures have shown that the resistance of cells to the antiproliferative action of dexamethasone, caused by their long cultivation with the hormone, is associated with the activation of PI3K and the transcription factor STATS. The activation of PI3K and STAT3 in the dexamethasone-resistant cells correlates with the increase in the total thyrosine kinase activity and with the decrease in the sensitivity of cells to exogenous proliferative agents, such as 17beta-estradiol. The long exposure of hormone-sensitive cells to nonhormonal factors that activate the PI3K/STAT3 signaling pathway, hypoxia in particular, has been shown to suffice to reduce the degree of hormonal tumor cell dependence. VEGF-A, an angiogenic peptide whose action was partially realizes through the PI3K-signalling pathway, has been demonstrated to be involved in the maintenance of cell growth, including the growth of hormone-independent cells. The findings suggest that complex changes in the antiapoptotic and mitogenic signaling pathways associated with PI3K, which ensures the autonomic, hormone-independent growth of tumor cells, may underlie the decreased hormonal dependence of tumor cells. Whether PI3K may be used to suppress the growth of hormone-independent tumors is discussed.

Adenocarcinoma↗

PubMed2004

[An experience with stenting the esophagus in patients with inoperable cancer].

An experience with treatment of 21 patients with inoperable cancer of the esophagus allowed determination of indications and contraindications, development of the method and technique of endoscopic implantation of a domestic meshed self-expanding stent. The complications resulting from the process of mounting and the stent itself are analyzed. The methods of eliminating the complications are shown. The immediate and nearest results of endoprosthesing are assessed. Recommendations are given concerned with the cases of ingrowth of tumor into the stent.

Aged↗

PubMed2003

Vascular endothelial growth factor in tumor tissue and blood serum from patients with breast cancer.

Enzyme immunoassay showed that the content of free vascular endothelial growth factor increases in tumor cytosols and blood serum from patients with breast cancer. A positive correlation was found between the contents of vascular endothelial growth factor in tumor cytosols and blood serum. After removal of the tumor the content of vascular endothelial growth factor decreased only in 49% patients. It should be emphasized that changes in these parameters did not depend on their initial values.

Breast Neoplasms↗

PubMed2003

[Urokinase and tissue type plasminogen activators and their type-1 inhibitor (PAI-1) in gastric cancer].

The levels of urokinase (uPA) and tissue type (tPA) plasminogen activators and their type 1 inhibitor (PAI-1) were determined by immunoassay in tumor cytosols and samples of histologically unaltered adjacent mucosa in gastric cancer patients. Gastric tumor revealed enhanced uPA and PAI-1 matched by decreased tPA in intact mucosa. The expression of uPA and PAI-1 was particularly was high at the later stages of the disease. The concentrations of uPA in tumor tissue increased with age. No significant correlation was established between levels of plasminogen activation system components, on the one hand, and histopathological grading of tumor, on the other.

Adolescent↗

PubMed2003

[Vascular endothelial growth factor and plasminogen activators in endometrial carcinoma and hyperplasia].

Vascular endothelial growth factor (VEGF) and such plasminogen activation system components as uPA, PAI-1 and tPA were determined by enzyme immunoassay methods in endometrial tumors from 121 patients and 18 samples of endometrial hyperplasia of varying degree. Endometrial carcinoma concentrations of uPA vs. PAI-1 were significantly higher than those in hyperplasia. Significant direct correlations--uPA vs. VEGF, uPA vs. PAI-1 and PAI-1 vs. VEGF--were established in endometrial tumors, and inverse ones for tPA vs. uPA and tPA vs. VEGF. A marked correlation with prognostic factors was found for PAI-1 and VEGF: levels of these proteins were relatively higher in cases of tumor progression (FIGO stage and deeper myometrial invasion), poor cell differentiation, and loss of hormone sensitivity. Higher uPA expression was associated with deeper myometrial invasion while, in endometrial tumors with unfavorable prognosis, it was VEGF level alone that was significantly higher.

Adult↗

PubMed2002

[Use of general anesthesia during fiber colonoscopy in cancer patients].

The evidence on the attitude of 60 cancer out-patients to fibrocolonoscopy carried out under general anesthesia was evaluated versus different procedures of intravenous injection. Most patients were scared prior to examination; 83.3% felt sleepy during the procedure while 85% of those anesthetized wouldn't mind receiving narcosis for repeat examination. Propofol (diprivan) alone showed an advantage over midazolam (dormicum) in being more tolerable and cutting stay at hospital by a third. Ketamin proved undesirable due to psychomimetic effects and delayed regaining of consciousness.

Adult↗