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Biomedical subjects

A M Nikitin

Publications and source records attributed to A M Nikitin.

At least 19 recordsLinked to original sources
PubMed1995

Mono-, di- and trimeric binding of a bis-netropsin to DNA.

An unusual 3:1 stoichiometry for complex formation between an elongated bis-netropsin compound and its binding site on DNA has been observed. Circular dichroism measurements distinguish two types of complexes formed between this bis-netropsin and poly[d(A-T)].poly[d(A-T)]. The first type is characterized by a 1:1 saturating ratio of bound molecules per ten base pairs. Formation of the second type results from the cooperative binding of two additional bis-netropsin molecules to the first type of complex. In contrast to these results observed for binding to the alternating polynucleotide, only the 1:1 type of complex is formed when this ligand binds to the homopolymer poly(dA).poly(dT).

Circular Dichroism↗
PubMed1994

[Effectiveness of preserving large intestinal segments in surgical treatment of proliferative diffuse polyposis].

Among 390 patients who were operated on in the Research Institute of Proctology for the proliferative form of diffuse polyposis, 242 underwent various types of operations in which polyp-free segments of the large intestine were not resected. In the first 5 postoperative years all 242 patients were examined, in follow-up periods of 6 to 10 years 144 patients (59.5%), in periods of 11 to 15 years 88 patients (36.4%), in periods of 16 to 20 years 28 patients (11.6%), and after 21 years 8 patients (3.3%) were examined. Development of carcinoma in the preserved segments was encountered in 26 patients (10.7%), and intensive growth of polyps for which the preserved segment had to be removed was found in 5 patients (2.1%). There was no significant increase of the risk of carcinoma development in the preserved intestinal segments in patients who previously had a malignant tumor in the resected part of the large intestine. The development of carcinoma and intensive growth of polyps were encountered most frequently in patients in whom the distal parts of the large intestine were not removed during the operation. The obtained data are evidence of the validity of the choice of the volume of the operation based on the endeavor to preserve the polyp-free parts of the large intestine for rehabilitation of the patients.

Adolescent↗
PubMed1993

[Malaria morbidity in Sevastopol (1944-1991)].

Malaria morbidity in Sevastopol in 1944 was 3192 per 100,000. Efforts on malaria control has resulted in liquidation of the disease in the town. For twenty years (1955-1974) infection had not been reported. There were 42 cases diagnosed from 1975 to 1991 in patients who had arrived from Asia and Africa. One patient died of tropic malaria. Measures against malaria should be carried out the whole year round in order to prevent outbreak of this grave infection in the town.

Africa↗
PubMed1993

[Results of preservation of distal parts of the large intestine in the surgical treatment of diffuse polyposis].

One hundred patients were examined in periods of one to 30 years after subtotal resection of the large intestine with the formation of an ileorectal or ileo-sigmoid anastomosis for diffuse polyposis with prevalence of proliferative processes. A malignant tumor developed in the preserved distal parts of the large intestine during this period in 19 (19%) persons. Such factors as the sex, age, duration of the postoperative follow-up period, the presence of a malignant tumor in the removed part, and the length of the functioning segment of the large intestine had no essential effect on the frequency of carcinoma. The presence of any number of polyps in the remaining part of the large intestine at the moment of the surgical intervention was the principal precondition for carcinoma development. The absence of polyps in it is a favorable factor for the survival of the operated on patients; in none of them did a malignant tumor develop in the preserved segment of the large intestine.

Adolescent↗
PubMed1993

[Comparative characteristics of various types of operations performed in treatment of diffuse colonic polyposis].

Diffuse polyposis of the large intestine characterized by the development of multiple polyps in it and their subsequent malignant degeneration is one of the most severe disease of the gastrointestinal tract. That it must be treated by surgery needs no proof. However, the volume and the character of the surgical intervention on the large intestine is still a debatable problem. The article discusses the experience in the follow-up of 445 patients for periods of 12 months to 30 years after operation for diffuse polyposis. In 228 patients various segments of the large intestine which were free from polyps were not resected. During these follow-up periods malignant tumors developed in the preserved parts of the large intestine in 10.1% patients and intensive growth of polyps was encountered in 3.5% of patients. The frequency of carcinoma development depended significantly less on the length of the follow-up period and much more on the character of affection of the preserved parts of the large intestine with the polyps.

Adolescent↗
PubMed1991

[The therapeutic procedure for desmoids in patients with diffuse polyposis of the large intestine].

Desmoid was diagnosed in 54 out of 632 patients who had been operated on for diffuse polyposis. The age of patients with desmoid ranged from 18-61 years. Twenty of them had desmoid in the anterior abdominal wall whereas 30--in the small intestine mesentery or retroperitoneal space. Dissection was carried out in 14 out of 18 patients with anterior abdominal wall desmoid. Recurrence was registered in 6 patients. Dissection was attempted in 12 out of 26 patients with intraabdominal desmoid but radical procedure could be performed in 5 only. In a group of 4 patients with synchronous desmoid of both sites, both tumors were removed in one patient only whereas in the other 3--only anterior abdominal wall tumor could be dissected.

Adolescent↗
PubMed1991

[Colectomy with resection of the rectal mucosa and formation of the ileo-rectal anastomosis as an alternative of permanent ileostomy].

A new method for surgical management of patients with diffuse polyposis of the large intestine is described. It was applied in 22 patients with total involvement of all parts of the large intestine in polyps. The essence of the suggested operation consists in preservation of the rectum after its demucosation and the formation of a cecal++-ileorectal anastomosis at the level of the pelvic peritoneum. The operative techniques are described. Experience in various types of intestinal anastomoses with a demucosated rectum as well as the techniques of the most optimal anastomosis are analysed. Retrospective analysis of the results of treatment allowed the authors to conclude that in inclusion of demucosated rectum into the intestinal passage its reservoir and accumulative function is maintained. Follow-up of the patients showed that small intestinal type mucosa regenerates in the rectum after mucosectomy in one third of patients and colonic-type mucosa in the remaining patients. It is pointed out that recurrent growth of polyps in the rectum after adequate demucosation was not encountered.

Adolescent↗
PubMed1991

[Presacral cysts in pregnant women].

Of the 14 women in whom presacral cysts were detected in connection with pregnancy or labor in only 4 this condition was diagnosed before labor, in the rest 10 it was revealed only in labor or after it; this fact points to the necessity of profound examinations of the presacral space in women who consult a physician because of pregnancy. If presacral cysts are detected in pregnancy terms of up to 12 weeks, abortions are advisable, if such cysts are detected later, the patient should be regularly examined by an obstetrician gynecologist and by a proctologist.

Abdominal Neoplasms↗
PubMed1991

[Endoscopic polypectomy in the surgical treatment of diffuse polyposis of the large intestine].

The article analyses experience in the treatment of 81 patients with diffuse polyposis who underwent subtotal resection of the colon with abdominoanal resection of the rectum and downward displacement of the right parts into the anal canal. It is shown that growth of the remaining occasional polyps and appearance of new polyps are encountered in the maintained parts of the colon and upper parts of the gastrointestinal tract in the postoperative period. The authors found that endoscopic polypectomy allows the right colon to be preserved in 92.6% of cases and the upper digestive tract in 97.5% of cases at a minimum risk of a surgical intervention.

Adult↗
PubMed1990

[Secretion of thyrocalcitonin and parathyroid hormone in diffuse polyposis of the colon].

The article presents data obtained in studying the content of calcium regulating hormone thyrocalcitonin and parathyroid hormone in blood plasma of patients with diffuse polyposis of the colon prior to and after a radical surgical treatment. The content of these hormones was also studied in extracts from colonic polyps. The concentration The concentration of thyrocalcitonin was found to decrease after operation. The elevated concentration of thyrocalcitonin was established in polyp extracts which might suggest its "ectopic secretion" in the polyp tissue in diffuse polyposis. Removal of the colon with polyps is followed by normalization of metabolism in the organism which proves the expediency of early surgical treatment.

Adenomatous Polyposis Coli↗
PubMed1990

[Comparative evaluation of the anal sphincter function after sphincter-sparing operations in diffuse polyposis].

Experience in treating 76 patients who were subjected to various sphincter-preserving operations is analysed. It is shown that after subtotal resection of the large intestine with ++abdomino-anal resection of the rectum and pull-through of the right parts of the colon into the anal canal as well as after pull-through of the segment of the transverse colon into the anal canal, the neuro-reflex activity of the musculus sphincter ani internus is destroyed in 55% and reduces in 25% of patients while the reflex activity of the musculus sphincter ani externus is disturbed in 45% of patients and is not restored later. The results bear evidence that the condition of the rectal obturation apparatus does not depend on the segment of the colon subjected to the pull-through operation (cecum, ascending colon, transverse colon). Experience has shown that the results of sphicterometry, electromyography, and electromanometry in various periods after colectomy, mucosectomy of the rectum, and formation of ileorectal anastomosis are much better than those after pull-through operations on various parts of the colon, and return to normal values in 18 months.

Anal Canal↗
PubMed1990

[Therapeutic tactics in patients operated on for diffuse polyposis of the colon].

The endoscopic sanitation is possible in patients operated upon for diffuse polyposis in cases of the absence of malignization of the polyps in the other parts of the colon. The endoscopic polypectomy performed on patients with diffuse polyposis allows preserving the rectum in 88.8% and the upper parts of the gastrointestinal tract in 99.1% of the cases.

Adult↗