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Biomedical subjects

V G Andreev

Publications and source records attributed to V G Andreev.

At least 37 records · Page 2Linked to original sources
PubMed1986

[Determination of the DNA-synthesizing cell count by the immunofluorescence method].

In DNA-synthesizing cells DNA is partially single-stranded. Anti-thymidine antibodies, while specifically reacting with this DNA, form a complex which may be revealed using indirect immunofluorescent technique. A comparative determination of DNA-synthesizing cell number in tumor tissue (larynx squamous cell carcinoma) was performed using immunofluorescent technique and radioautography. The former method showed the labeling index (LI) to vary from 1.2 to 9.9%, while the latter showed it to vary from 1.0 to 8.2%. The correlation ratio between the LI values obtained by the two techniques was 0.79. To eliminate a possible reaction of anti-thymidine antibodies with cellular RNA, specimens were preincubated in solutions with RNAase. No more than 6 hours were required to stain specimens using this LI estimation technique. This investigation allows to reveal DNA synthesizing cells not only in the periphery of a histological section, as does routinely radioautography, but also in its centre.

Animals↗
PubMed1986

[Combination treatment of recurring laryngeal cancer].

The results of treatment of 192 patients with recurring and incurable laryngeal cancer after a previous course of radiotherapy were studied. Of the total number of patients 95 were treated by surgery only and 97 received a preoperative course of intensive radiotherapy. The study has shown that the irradiation of recurring and incurable by radiotherapy tumors of the larynx at a dose of 6 Gy on the eve and on the day of operation (a summary focal dose of 12 Gy, DMF--37 units) permits an increase of the index of uncomplicated healing of the laryngeal wound from 68.4 up to 86%; simultaneously the 3-year recurrence and metastasis-free survival rates increase from 47.8 up to 81.4%.

Adult↗
PubMed1986

[Radiation and combination treatment of maxillary cancer using metronidazole].

A study was made of the results of therapy of 66 patients with maxillary cancer, of them 31 (a control group) received routine therapy by a method of summary focal dose (SFD) fractionation--60-70 Gy. In the study group (35 patients) treatment was started with large fractions at a dose of 5 Gy 2 times a week up to SFD of 20 Gy using metronidazole 2.5-3 h before each of the first 4 large fractions and continued using a course with SFD up to 52 Gy by common fractionation. Staged assessment of the results of radiotherapy was done when the summary dose reached 40 Gy in the control group and 32 Gy in the study group. Complete regression of a tumor or a decrease in its volume by more than 50% at these doses were noted in 13 (41.9%) patients of the control group and in 23 (65.7%) patients of the study group. After combined treatment of a slightly decreased tumor preirradiated in a summary dose of 40 Gy and 32 Gy the 3-year recurrence-free survival was noted in 72.2% (13 patients) in the control group and in 91.7% (11 patients) in the study group. The results obtained are indicative of a marked radiosensitizing effect of metronidazole in radical radiation and combined radiation therapy of maxillary cancer improving long-term results.

Adult↗
PubMed1985

[The results of metronidazole use in radiation and combined treatment of patients with laryngeal cancer].

The paper is concerned with the results of radiation and combined therapy of 153 laryngeal cancer patients. Of them 103 received radiotherapy combined with metronidazole at a dose of 5-8 g/m2 2.5-3 h before an irradiation session, 50 patients were controls. Radiotherapy was given by mean fractions at a dose of 5 Gy 2 times a week with a summary focal dose of 20 Gy with subsequent irradiation at a daily dose of 2 Gy up to a summary dose of 32 Gy. The efficacy of radiotherapy was evaluated after a 2-week discontinuation. In a complete resorption or lessening of a tumor volume by more than 70% radiotherapy was continued by conventional fractionation at a daily dose of 2 Gy up to a summary focal dose of 52 Gy. In insignificant lessening of a tumor volume the patients were operated on. The use of metronidazole in a radical course of radiotherapy of laryngeal cancer patients did not improve therapeutic results, however the number of postoperative complications caused by surgical treatment for tumor recurrences increased 3 times. In combined treatment of the laryngeal cancer patients after a summary focal dose of 32 Gy and 1.5-3 years of follow-up the number of the patients increased up to 75.7% as compared to 50% in the control group. A decrease in the number of postoperative complications was noted.

Adult↗
PubMed1985

[Morphology of laryngeal cancer in radiotherapy combined with the use of metronidazole].

The authors described clinicomorphological correlations in the evaluation of the efficacy of preoperative radiotherapy combined with metronidazole (MZ) in laryngeal cancer patients. A study was made of the tumors from 61 laryngeal cancer patients following radiation exposure at a summary dose of 20 and 32 Gy with and without MZ. Histological change of a tumor confirmed a radiosensitizing effect of MZ. However the MZ effect was not equally noticeable in tumor central and peripheral parts. Microscopic foci of the affected epithelium of the larynx and gland mucosa, muscular cells and vessels were revealed. MZ produces a stimulating effect on collagen production by fibroblasts.

Adult↗
PubMed1985

[Teleradiotherapy of laryngeal cancer using a gas hypoxic mixture (GHM-10)].

A total of 96 laryngeal cancer patients were studied. A comparative analysis of short-term therapeutic results was performed in 2 similar groups: patients receiving radiotherapy without GHM-10 (50) and those receiving radiotherapy with the use of GHM-10 containing 10% of oxygen and 90% of nitrogen (46). Irradiation methods and general tactics of the patients management in both groups were identical. No differences in the short-term results were noted. Radiation reactions of the healthy tissues were less pronounced and noted less frequently in the patients on radiotherapy with the use of GHM-10.

Adult↗
PubMed1985

[Combined (radiation and surgical) treatment of laryngeal cancer patients using metronidazole].

The results of combined treatment of 98 laryngeal cancer patients followed up for 1.5-3 years were analysed. Of them 68 received a preoperative radiotherapy course combined with the electron acceptor compound metronidazole. The drug was given in the form of a sugar syrup suspension at a dose of 100-150 mg/kg bw 2.5-3 hours before each of the 4 fractions of irradiation, at 5 Gy twice a week reaching a summary focal dose of 20 Gy. Thirty patients received radiation therapy without metronidazole. Altogether 4 preoperative radiotherapy methods were used. An analysis of the results showed a significant improvement of the cure rates for laryngeal cancer patients using metronidazole, particularly for those with advanced stages. A better healing of postoperative wounds was noted. The author proved the appropriateness of preoperative irradiation by mean fractions up to a summary focal dose of 20 Gy combined with metronidazole and subsequent (on the last or next day of irradiation) radical operation.

Adult↗
PubMed1984

[Kidney function during radiosensitization with metronidazole].

Renal function was studied in patients with laryngeal cancer during radiation therapy performed under the conditions of mean fractionation in the presence of metronidazole radiosensitization up to the summary focal dose of 20 Gy. As compared to the findings before treatment an increase in the level of residual nitrogen, urea, uric acid and a decreased amount of creatinine in the plasma were noted. Decreased clearance of the urea, elevated Ambard's urosecretory constant were observed. The nature of these shifts was preserved even after the termination of subsequent radiation therapy up to the summary focal dose of 32 Gy without using the radiosensitogen. There is a possibility of a direct toxic effect of metronidazole on the renal tissue regardless of the state of oxygenation.

Blood Urea Nitrogen↗
PubMed1984

[State of the liver after radiotherapy of cancer of the stomach and larynx with metronidazole radiosensitization].

The use of metronidazole in radiation therapy of laryngeal cancer (SFD = 20 Gy) as a radiosensitizer of tumor hypoxic cells resulted in changes of the liver function tests: a decrease in the cholinesterase activity, a decrease in the level of cholesterol and albumin esters in the blood serum that characterize synthetic liver function. Similar though more noticeable in amounts shifts were marked in stomach cancer patients following preoperative irradiation (SFD = 20 Gy). A slight decrease in AP activity and a decrease in LDH activity below the initial level were simultaneously noted in the latter group as opposed to the group of laryngeal cancer patients. The deviations from the initial level of such liver function indices as bilirubin and total protein level, alanine and asparagine aminotransferase activity did not depend on the incorporation of metronidazole in the radiotherapeutic scheme and developed one way in the intervention and control groups of patients disregarding tumor site. The comparison of shifts of the liver tests in stomach and laryngeal cancer patients in whom tumor site was responsible for the incorporation of the liver in the irradiated zone or for the distance from it, made it possible to regard MZ direct toxic effect and its radiosensitizing effect on the hepatic tissue as causes of the observed deviations.

Humans↗
PubMed1984

[Medullary hematopoiesis in laryngeal cancer during radiotherapy using metronidazole].

To investigate the blood system response to the use of radiation therapy with metronidazole as a radiosensitizer, a study was made of the peripheral blood and bone marrow (at the light and electron microscopy level) in 46 patients with laryngeal cancer who had been subjected to local therapeutic irradiation at a summary focal dose up to 32 Gy. Twenty-eight patients received radiotherapy in the presence of a radiosensitizing effect of metronidazole, the others without a modifier. The patients ranged in age between 30 and 65. It has been shown that the medullary hemopoiesis of patients with laryngeal cancer is characterized by a considerable variability of the main indices: from hyperplasia of the hemopoietic tissue to the depression of myelopoiesis. The general signs of the bone marrow state were the intensity of erythropoiesis, high lymphocyte, monocyte, reticular and plasma cell counts, change of the partial morphograms of granulocytes and erythrokaryocytes that attest to the inhibition of the maturation of myelokaryocytes. The use of metronidazole as a radiosensitizer as distinct from purely radiation effects results in a high leukocyte count at the expense of the proliferating pool of the granulocytic growth of the bone marrow as well as in a larger share of ineffective erythropoiesis with a corresponding decrease of red blood indices. The disturbances revealed do not restrict indications to the use of metronidazole as a radiosensitizer.

Adult↗
PubMedDate not supplied

[Apoptosis of peripheral lymphocytes of healthy donors and patients with laryngeal neoplasms after gamma-irradiation in vitro].

Apoptosis in peripheral blood lymphocytes of healthy donors and cancer patients after gamma-irradiation with different doses was studied by the flow cytometry method. Wide intra- and interindividual variabilities of the lymphocyte radiosensitivity were observed. The radiosensitivity did not depend on the subpopulation composition of the lymphocyte pool. The persons with very low and high lymphocyte radiosensitivities were found significantly more often among the cancer patients than among the healthy donors. One can suggest that this method is useful as a biomarker of future cancer risk and prognosis of radiotherapy efficiency.

Apoptosis↗
PubMedDate not supplied

[The effect of irradiation on the growth of human laryngeal tumors transplanted under the kidney capsule of immunocompetent mice].

A study was made of the influence of gamma-radiation on the growth of human larynx squamous cell carcinoma transplanted under the capsule of the kidney of immunocompetent mice. The transplants were shown to increase in size 6 days after transplantation. Irradiation of animals 24 h after transplantation inhibited considerably the tumor growth. However, the preirradiation (24 h before operation) inhibited the growth of nonirradiated transplants to the same extent as the exposure of mice with the transplanted tumor fragments did: the radiation dose that induced 50% inhibition of the growth was 4.5 Gy and 5.3 Gy, respectively. Preliminary data indicate that tumor fragment of patients with the unfavourable prognosis increase in size and respond to radiation to a lesser extent.

Animals↗