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Biomedical subjects

V K Kovalev

Publications and source records attributed to V K Kovalev.

At least 19 recordsLinked to original sources
PubMed1998

[Damage to the transforming growth factor TGF-beta type II receptor gene and microsatellite instability in carcinoma cells of the gastrointestinal tract].

In order to compare the frequency of damage to the transforming growth factor TGF-beta receptor type II gene (RII gene) and microsatellite instability (MIN) in oncogenesis of sporadic and hereditary cancer of gastrointestinal tract (GIT), 4 groups of carcinomas were analyzed. They included sporadic gastric (GC), family gastric (FGC), sporadic colorectal (CC) and hereditary nonpolyposis colorectal (HNPCC) carcinomas having appropriate clinical and pathological characteristics. Each group consisted of two types of carcinomas, one of them showing MIN. The RII gene damage occurred in 89% of GC (8 cases out of 9), 86% of CC (6 out of 7), 71% of FGC (5 out of 7), 50% of HNPCC (3 out of 6) for carcinomas coupled with MIN, whereas only in 6% (1 out of 18) of GC and 5% (1 out of 22) of CC for carcinomas without MIN. No damage to RII gene was found in the cases of hereditary carcinomas which did not show MIN though the number of cases analyzed was not sufficient for final conclusions (3 cases of FGC and 3 HNPCC). The data revealed a correlation between the MIN phenotype and mutations in RII gene both for sporadic (p < 0.001) and for hereditary (p < 0.02) cases. For all 4 groups the frequency of RII gene damage was found for early and advanced carcinomas. This suggests that the deficiency of TGF-beta receptor complex in both sporadic and hereditary carcinomas of GIT is revealed at early stages of tumor development and consequently may be responsible for tumor progression. The correlation between RII gene damages and MIN in GIT carcinoma cells suggests that genetic change predetermined the neoplasia of colorectal and gastric epithelium and partially overlapped for both sporadic and hereditary cases.

Colorectal Neoplasms↗
PubMed1998

[Microsatellite instability of genome in cells of sporadic and hereditary carcinoma of the gastrointestinal tract].

Microsatellite instability (MIN) of human genome, i.e. instability of very short (1-5 nt) DNA tandem repeats, points to a deficiency in the mismatch repair system (MMR). To investigate the role of MMR in sporadic and hereditary carcinogenesis in the gastrointestinal tract, four types of carcinomas were compared: sporadic (GC), familial (FGC) gastric carcinoma, sporadic colorectal (CC) and hereditary nonpolyposis colorectal (HNPCC) carcinoma. No significant difference in MIN frequency was found between GC (9 out of 27) (33%) and CC (7 out of 29) (24%). In hereditary carcinoma group, MIN occurrence appeared 2-3 times as high: FGC in 7 out of 10 (70%) and HNPCC in 6 out of 8 patients (75%). No significant differences were recorded in MIN occurrence at early and later stages of the disease in all groups. Therefore, it can be suggested that disorders in the MMR develop at earlier stages of carcinogenesis and may be responsible for tumor progression.

Base Sequence↗
PubMed1997

[Current trends in the diagnosis and therapy of colorectal cancer].

The report deals with the 30-year experience gained by the Department in the treatment of nearly 5,500 cases of tumors of large bowel. Radical surgery for colonic tumor was followed by lethality in 3.0 and 5-year survival-80.8%; rectal tumor resection-5.3 and 58.2%, respectively. Individually-tailored modalities have been devised for a spectrum of cases of colonic wall invasion and metastatic lesions in regional lymph nodes. A choice of sparing, extended and combined surgical procedures vis-a-vis these factors has been developed, the latter offering most advantage. Therapeutic strategies for hepatic metastasis have been worked out on individual basis.

Colorectal Neoplasms↗
PubMed1997

[Current principles of surgical treatment for early colorectal neoplasms].

A distinct correlation between tumor process expansion within the large bowel wall and dissemination has been established thus suggesting a concept of early colorectal cancer. Indications for limited surgery for early large bowel cancers are discussed. Both local excision and standard radical surgery offer practically the same advantage in cases of carcinoma located within mucosa and the submucosal layer of the intestinal wall.

Colectomy↗
PubMed1996

[A rational surgical procedure in diffuse polyposis and multiple primary cancer against a background of polyps of the large intestine].

Under examination there were 292 patients. An analysis of results of treatment enabled the authors to conclude that surgical treatment of patients with diffuse polyposis of the colon is the method of choice. The method and volume of operations must be determined according to the involvement of the colon in polyposis, the age and state of the patients. The best method of surgery is a one-step radical operation-subtotal resection of the colon. Polyps concomitant to cancer of the colon should be ablated before the main operation since their histological analysis can change the volume of the planned radical operation. When choosing the method of surgical intervention for patients with primary-multiple cancer against the background of polyps the total portion of the colon with polyps should be ablated.

Colectomy↗
PubMed1989

[The initial forms of rectal cancer].

The paper discusses the tumor characteristics and long-term results of treatment of 6875 cases of rectal cancer admitted to oncological institutions of the USSR within 1968-1980. Stage I-IIa ("minimal") tumors were detected in 9.4% of patients. Organ-saving procedures (local excision included) were performed in 57%. Five-year actuarial survival following surgery was 63% according to the All-Union Center for Research on Effectiveness of Cancer Treatment and 74%--according to the N. N. Petrov Research Institute of Oncology data.

Adult↗
PubMed1988

[Treatment of cancer of the rectum by electrocoagulation].

The destruction of rectum carcinoma by electrocoagulation can be used for the treatment of patients of older age groups with high operative risk having exophite tumors of the inferior ampular part not more than 3 cm in size. When observing the conditions concerned and careful dispensary examination, the efficiency of immediate and long-term results of this operation are not inferior to generally used routine methods of treatment. Electrocoagulation of rectum carcinoma must be fulfilled but at oncological and specially equipped oncoproctological units.

Age Factors↗
PubMed1988

[Diagnostic significance of lymphoscintigraphy in cancer of the rectum].

Lymphoscintigraphic data were compared with the results of morphologic examination of resected regional lymph nodes in 51 cases of rectal cancer. Radionuclide method accuracy proved to be 80%, specificity--65% and sensitivity--96%. Correct diagnosis of metastasis was made in 73% while absence of metastases was reliably confirmed in 94%.

Humans↗
PubMed1987

[Diagnostic errors and inadequate therapeutic tactics in tumors of the large intestines].

The authors observed 21 patients after previous non-radical treatment in other medical institutions. The age of the patients was from 38 to 80. Radical operations were performed on all the patients during relaparotomies. The authors make a conclusion that choice of a rational surgical and curative tactics in colonic tumors was determined individually with special reference to the general state of the patient, careful assessment of the degree of local spread of the tumor. A dogmatic approach is thought to be inadmissible.

Adult↗
PubMed1985

[A method of treating villous tumors of the rectum].

A method of dissection of the rectum mucosa together with the tumor is described. The mucosa defect is closed by bringing the mucous membrane down and putting stitches on all the circumference. Successful operations were performed on 7 patients.

Female↗
PubMed1984

[Clinical manifestations of squamous cell carcinoma of the rectum].

The report deals with an evaluation of the data on 107 cases of squamous cell carcinoma of the rectum. 63 patients (58.8%) had proctological diseases in their case histories. Anal carcinoma is being misdiagnosed at out-patient hospitals as some other proctologic lesion in 34.9%. This fact points to the staff's lack of knowledge of the clinical picture of squamous cell carcinoma of the rectum. Abdominal-perineal extirpation of the rectum was the most frequent procedure used in the treatment of squamous cell carcinoma.

Adenocarcinoma↗
PubMed1982

The relation between the status of adaptive system and the number of postoperative complications in patients with gastrointestinal cancer: the effect of phenazepam.

The decrease in 11-hydroxycorticosteroids concentration caused by 0.5 mg of dexamethasone administered at 11 pm was studied in 91 primary patients suffering from gastrointestinal cancer. In dexamethasone-resistant patients postoperative complications developed in 65% of colon cancer patients and in 42% of stomach cancer patients. In dexamethasone-sensitive patients the complications were observed in 24% and 12% of patients, correspondingly. The elevation of hypothalamic threshold of sensitivity to the inhibiting effect of glucocorticoids, revealed by the dexamethasone suppression test, was considered to be as result of a combined action of age, the tumor itself, and pronounced emotional stress during the preparation for operation. The derivative of benzodiazepin--phenazepam--when administered before the operation in colon cancer patients improved the results of the dexamethasone suppression test and decreased the number of postoperative complications.

11-Hydroxycorticosteroids↗
PubMed1980

[Urolithiasis].

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Colic↗