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Biomedical subjects

A V Sotnikov

Publications and source records attributed to A V Sotnikov.

17 recordsLinked to original sources
PubMed2002

[Diagnosis and treatment of patients with acute postintubation and post-tracheostomy stenosis of the larynx and trachea].

The data on diagnosis and treatment of 200 patients with acute postintubation laryngostenosis (LS) and tracheostenosis (TS) are reviewed. Peculiarities of tracheostomy technique practiced in critical care units are specified. Postintubation and posttracheostomy alterations in the larynx and trachea detected endoscopically are described. Effective endosurgical methods are proposed to avoid multistage surgical rehabilitation for recovery of the respiration function in 97% LS and TS patients.

Acute Disease↗
PubMed1999

Energy intake and prostate tumor growth, angiogenesis, and vascular endothelial growth factor expression.

BACKGROUND: A sedentary lifestyle coupled with excessive energy intake is speculated to be a factor associated with increased incidence of prostate cancer. We have investigated the effects of energy intake on prostate tumor growth in experimental animals. METHODS: Two transplantable prostate tumor models, i.e., the androgen-dependent Dunning R3327-H adenocarcinoma in rats and the androgen-sensitive LNCaP human carcinoma in severe combined immunodeficient mice, were studied. R3327-H tumor growth and relevant tumor biomarkers (proliferation index, apoptosis [programmed cell death], microvessel density, and vascular endothelial growth factor [VEGF] expression) were compared in ad libitum fed control rats, ad libitum fed castrated rats, and groups restricted in energy intake by 20% or 40%. A second set of experiments involving both tumor models examined tumor growth in ad libitum fed rats or in animals whose energy intake was restricted by 30% using three different methods, i.e., total diet restriction, carbohydrate restriction, or lipid restriction. All P values are two-sided. RESULTS: R3327-H tumors were smaller in energy-restricted or castrated rats than in control rats (P<.001). Tumors from energy-restricted rats exhibited changes in tumor architecture characterized by increased stroma and more homogeneous and smaller glands. In castrated rats, the tumor proliferation index was reduced (P<.0001), whereas apoptosis was increased in both energy-restricted (P<.001) and castrated (P<.001) rats. Tumor microvessel density and VEGF expression were reduced by energy restriction and castration (P<.003 versus control). Restriction of energy intake by reduction of carbohydrate intake, lipid intake, or total diet produced a similar inhibition of growth of R3327-H or LNCaP tumors. These effects were associated with reduced circulating insulin-like growth factor-I. CONCLUSIONS: Our observations are consistent with the hypothesis that energy restriction reduces prostate tumor growth by inhibiting tumor angiogenesis. Furthermore, dietary fat concentration does not influence prostate tumor growth when energy intake is reduced.

Adenocarcinoma↗
PubMed1998

[The surgical and endoscopic treatments of benign submucosal tumors of the esophagus, stomach and duodenum].

Analysis of the results of various modes of treatment and follow-up of 160 patients with benign submucosal tumors (BST) was carried out. Most often histological type of BST was leiomyoma (43.7%). BST were mainly located in the stomach (68.7%). 22 patients underwent open operations, 37--endoscopical removal of BST, 101 patients were followed-up from 5 to 10 years. The analysis of the material makes it possible to come to the conclusions about advisability of endoscopical treatment. The results of which are not inferior to surgical method of treatment. In patients with absence or slow growth of BST endoscopic follow-up is valid.

Duodenal Neoplasms↗
PubMed1997

[Vibration bouginage in the cicatricial strictures of esophagus].

In 66 patients for the dilation of the cicatricial stricture of the esophagus vibration method was used. In 48 patients the vibrator was attached to proximal end of the bouge, in 18 patients the vibration device was introduced directly in the area of the stricture. The suggested method provided an easy and fast dilation of the stricture in 63 patients. In 3 cases surgical treatment was carried out because multiple strictures in separate areas resulted in complete obliteration of the esophagus. There were no complications due to the vibrobouginage. For the treatment of inflammatory disorders of the esophagus and for prophylaxis of the scar formation in the area of stricture in 29 patients the therapeutic laser irradiation was used. This treatment has ensured promising results.

Adolescent↗
PubMed1996

Quantification of proliferating cell nuclear antigen in large intestinal crypt by computer-assisted image analysis.

Measurements of proliferating cell nuclear antigen (PCNA) labeling of the large intestinal crypts scored by experienced observers were compared with those generated by computer-assisted image analysis (CAIA). (CAIA was performed at Pathology Expertise, Inc., Newton, MA, by A. V. Sotnikov.) Serial sections (3 microns) of the rectal biopsy specimens from 32 patients were immunostained for PCNA and then counterstained with hematoxylin. The same set of slides and rules for the location/acquisition of complete crypts was used to assess a minimum of ten complete crypts/patient. Each crypt was subdivided longitudinally into five equal compartments. With CAIA, the images were stored digitally, and once the color references were set, the areas occupied by labeled and counterstained nuclei were quantified automatically. The labeling index (LI) was calculated from the PCNA-labeled nuclei area/total nuclei area in CAIA and from the number of labeled cells/total number of cells in visual scoring. The LI of whole crypts averaged 1.04 +/- 0.18 by CAIA and 3.91 +/- 0.46 by the visual method, and the Spearman correlation (rs) between the two methods was 0.89. The different modes of evaluation and color reference selection are likely to have contributed to the differences in the LI ranges observed in the two methods. The high correlation between PCNA quantification by CAIA and visual scoring by experienced technicians indicates that CAIA can reliably rank individual subjects. Thus, measurement of PCNA labeling by CAIA is a practical alternative for evaluating colorectal epithelial cell proliferation.

Adult↗
PubMed1996

Digital imaging in anatomic pathology.

Advances in computer technology continue to bring new innovations to departments of anatomic pathology. This article briefly reviews the present status of digital optical imaging, and explores the directions that this technology may lead over the next several years. Technical requirements for digital microscopic and gross imaging, and the available options for image archival and retrieval are summarized. The advantages of digital images over conventional photography in the conference room, and the usefulness of digital imaging in the frozen section suite and gross room, as an adjunct to surgical signout and as a resource for training and education, are discussed. An approach to the future construction of digital histologic sections and the computer as microscope is described. The digital technologic applications that are now available as components of the surgical pathologist's workstation are enumerated. These include laboratory information systems, computerized voice recognition, and on-line or CD-based literature searching, texts and atlases and, in some departments, on-line image databases. The authors suggest that, in addition to these resources that are already available, tomorrow's surgical pathology workstation will include network-linked digital histologic databases, on-line software for image analysis and 3-D image enhancement, expert systems, and ultimately, advanced pattern recognition capabilities. In conclusion, the authors submit that digital optical imaging is likely to have a significant and positive impact on the future development of anatomic pathology.

Humans↗
PubMed1992

Cotton rats previously immunized with a chimeric RSV FG glycoprotein develop enhanced pulmonary pathology when infected with RSV, a phenomenon not encountered following immunization with vaccinia--RSV recombinants or RSV.

In studies conducted in the 1960s, children previously immunized with a formalin-inactivated respiratory syncytial virus (RSV) vaccine (FI-RSV) developed a greater incidence and severity of pulmonary disease during subsequent natural RSV infection than did controls. It was previously shown that cotton rats immunized with FI-RSV or immunoaffinity-purified fusion (F) glycoprotein developed enhanced pulmonary histopathology following intranasal challenge with RSV. In the present studies, various forms of immunization, including parenteral inoculation of an immunoaffinity-purified F glycoprotein or a chimeric FG glycoprotein produced in insect cells using a baculovirus vector (Bac-FG), intradermal infection with a vaccinia-F recombinant (Vac-F) or intranasal infection with an adenovirus-F recombinant (Ad-F) or RSV, were compared for immunogenicity, efficacy and ability to alter the host so that enhanced pulmonary histopathology developed during RSV infection 3 months after immunization. Immunization of cotton rats with F glycoprotein, Bac-FG, Vac-F, Ad-F or infection with RSV induced high levels of ELISA-F antibodies, but the antibodies induced by purified F glycoprotein of Bac-FG had low levels of neutralizing activity. Immunization with Vac-F or Ad-F, or infection with RSV induced a high level of resistance to pulmonary RSV replication, whereas animals immunized with Bac-FG or FI-RSV were only partially protected. Following RSV challenge, animals immunized with purified F glycoprotein or Bac-FG developed the highest levels of bronchiolar and alveolar histopathology, those immunized with FI-RSV had intermediate levels, and those immunized with Vac-F or RSV had histopathology scores at control levels. Ad-F immunized animals had elevated scores of bronchiolar but not alveolar histopathology; however, this finding was not reproducible. Passive transfer of pooled immune sera from animals infected with RSV or Vac-F and Vac-G was highly protective, whereas pooled sera from animals immunized with Bac-FG failed to protect the lungs against RSV challenge. Increased pulmonary histopathology was not observed in the passively immunized animals following RSV challenge, suggesting that the histopathology was mediated by RSV-specific T cells. These data indicate that subunit F glycoprotein or chimeric FG vaccines share with FI-RSV the properties of (i) induction of F antibodies with low neutralizing activity and (ii) enhancement of pulmonary histopathology during subsequent RSV infection. These observations confirm the need for caution in studies involving the administration of RSV subunit vaccines to seronegative humans.

Animals↗
PubMed1992

Pulmonary histopathology induced by respiratory syncytial virus (RSV) challenge of formalin-inactivated RSV-immunized BALB/c mice is abrogated by depletion of CD4+ T cells.

In previous studies, it was observed that children immunized with a formalin-inactivated respiratory syncytial virus vaccine (FI-RSV) developed severe pulmonary disease with greater frequency during subsequent natural RSV infection than did controls. During earlier efforts to develop an animal model of this phenomenon, enhanced pulmonary histopathology was observed after intranasal RSV challenge of FI-RSV-immunized cotton rats. Progress in understanding the immunologic basis for these observations has been hampered by the lack of reagents useful in manipulating the immune response of the cotton rat. This problem prompted us to reinvestigate the characteristics of immunity to RSV in the mouse. In the present studies, extensive pulmonary histopathology was observed in FI-RSV-immunized or RSV-infected BALB/c mice upon RSV challenge, and studies to determine the relative contributions of CD4+ or CD8+ T cells to this process were undertaken. Mice previously immunized with FI-RSV or infected with RSV were depleted of CD4+, CD8+, or both T-cell subsets immediately prior to RSV challenge, and the magnitude of inflammatory cell infiltration around bronchioles and pulmonary blood vessels and into alveolar spaces was quantified. The magnitude of infiltration at each anatomic site in previously FI-RSV-immunized or RSV-infected, nondepleted animals was similar, indicating that this is not a relevant model for enhanced disease. However, the effect of T-cell subset depletion on pulmonary histopathology following RSV challenge was very different between the two groups. Depletion of CD4+ T cells completely abrogated pulmonary histopathology in FI-RSV-immunized mice, whereas it had a much smaller effect on mice previously infected with RSV. FI-RSV-immunized or RSV-infected animals depleted of CD8+ T cells had only a modest reduction of pulmonary histopathology. In addition, RSV infection induced high levels of major histocompatibility complex class I-restricted cytotoxic T-cell activity, whereas FI-RSV immunization induced a low level. These data indicate that immunization with FI-RSV induces a cellular immune response different from that induced by RSV infection, which likely played a role in enhanced disease observed in infants and children.

Animals↗
PubMed1990

Enhanced pulmonary histopathology is observed in cotton rats immunized with formalin-inactivated respiratory syncytial virus (RSV) or purified F glycoprotein and challenged with RSV 3-6 months after immunization.

Formalin-inactivated (FI) RSV, purified F glycoprotein in alum, and RSV infection (intranasal) were compared for their immunogenicity, efficacy, and ability to enhance pulmonary histopathology during RSV infection 3 and 6 months following immunization by the intramuscular route. Purified influenza virus in alum was used as a control immunogen. At 1 month following immunization with one dose of purified F glycoprotein (5 micrograms), cotton rats developed levels of F antibodies (ELISA) higher than the other groups, but these antibodies had the lowest level of neutralizing activity, Little increase in antibody titre was seen following a second dose of FI-RSV or purified F vaccine given at 1 month. Animals that received 5 micrograms F, 0.5 microgram F, or were almost completely resistant to pulmonary RSV infection following challenge at 3 months, but were susceptible by 6 months. Animals immunized with 5 micrograms of purified F glycoprotein developed alveolar and bronchiolar histopathology following RSV challenge at 3 or 6 months which was comparable to that of animals immunized with FI-RSV. These levels significantly exceeded those in animals previously immunized with influenza A virus vaccine which exhibited little histopathology. Animals previously infected with RSV also developed bronchiolar, but not alveolar, histopathology suggesting that the bronchiolar histopathology seen in RSV challenged cotton rats is a normal component of the immune resolution of RSV infection. These results suggest that the immune response of cotton rats to immunoaffinity purified F glycoprotein can result in enhanced bronchiolar and alveolar histopathology following RSV challenge. Thus, caution should be exercised in studies in humans using a purified F glycoprotein subunit vaccine.

Animals↗
PubMed1986

[Immunomorphological study of fibronectin and collagen types I, III, IV and V in the myocardium in cardiosclerosis].

Fibronectin and collagen, types I, III, IV and V, in the granulation tissue replacing the myocardial infarction, in the focal and diffuse cardiosclerosis were studied by means of the immunofluorescent method. The extracellular matrix in the granulation tissue contained fibronectin and collagen of the above types. Intracellular fibronectin was also found in the necrotized cardiomyocytes. Fibronectin and collagen of type IV were not detected in the postinfarction scars. The extracellular matrix consisted mainly of collagen, types III and V. Fibronectin and collagen, types I, III and V, are observed in the connective tissue in diffuse cardiosclerosis in the presence of the coronary arteries stenosis. No prevalence of the collagen of any type was found.

Aged↗
PubMedDate not supplied

Diet: the neglected variable in chemical safety evaluations.

The objectives of this review are to alert the community of toxicologic pathologists to the types and significance of various diets fed to experimental animals used in safety evaluations of drugs and other chemicals, to acquaint investigators with dietary nutrients and contaminants of significance to research animals, to review some of the consequences of improper or inadequate diets on results of safety evaluations, and, finally, to offer a brief introduction to a highly promising new digital specimen technology for evaluating histopathology of tissues from animals used in safety evaluations with the aid of computers. Results that form the basis for this review have accumulated for more than 4 decades during research conducted during appointments at the University of Missouri, Columbia; Auburn University; Massachusetts Institute of Technology; and Boston University School of Medicine. The methods used in these studies have generally been state-of-the-art at the time the studies were conducted and involved an integration of techniques and methods used in fundamental nutrition, toxicology, and experimental pathology. Some of these investigations have shown that contaminants, naturally occurring and man-made, intentional and nonintentional, do occur in commercial animal diets; that essential nutrients, including total calories, protein and fat, can be provided in less or more than adequate amounts for the species of animal used in safety evaluations; and that such variables can influence responses to chemicals through effects on xenobiotic metabolism, immunocompetence, secondary diseases, and other factors. Under such conditions, serious differences in final interpretation of human risk for a drug or other chemical can contribute to failure to gain approval for a potentially valuable therapeutic agent. This review discusses the significance of various dietary components with examples of their effects on response of the animal to chemicals and demonstrates why nutrients, new technologies for assessing their effects, and other components in the diet should be accorded greater consideration by investigators and regulators.

Animal Feed↗
PubMedDate not supplied

[Prognostic value of SAPS II and APACHE II scales in patients with multiple organ failure syndrome during early postoperative period after oncological surgery].

The key fixed task was the following: detection, as soon as possible, of patients with a high risk of lethal outcome; an objective assessment of the condition of patients during the early postoperative period by using a quantitative evaluation (SAPS II, APACHE II); and defining of the prognostic value of SAPS II and APACHE II after oncology surgeries. The in-hospital lethality amounted to 53% in 73 patients with MOFS during the early postoperative period after oncology surgeries. The formalized (numerical) score, according to SAPS II and APACHE II, made it possible to detect patients with a higher risk of lethal outcome yet during the very first day after oncology surgeries. If the score of SAPS II or APACHE II topped 30 (on the first day after surgery), then the in-hospital lethality exceeded 50%. The information density of the SAPS II and APACHE II systems turned out to be identical, however, SAPS II appears to be more convenient in terms of practical usage since it demands the evolution of a smaller number of physiological parameters.

APACHE↗
PubMedDate not supplied

[Endoscopic diagnosis and treatment of cicatricial esophageal strictures].

The paper summarizes the experience gained by the authors in 10-year treatment of esophageal cicatricial strictures. Work-up and treatment results available on 107 relevant patients provided evidence on the leading role of endoscopic diagnosis in cicatricial strictures, while endoscopic bouginage is effective treatment of the strictures. To prevent recurrences esophageal bouginage should be combined with drug and laser therapy. The immediate response was reached in 91 (85%) patients. Long-term response was good only in 34 (46.6%) patients. Six slight complications passed off without special treatment.

Adolescent↗