PubMed Health⌕ Search

Biomedical subjects

V Bychkov

Publications and source records attributed to V Bychkov.

16 recordsLinked to original sources
PubMed2000

Velocity of turbulent flamelets with realistic fuel expansion.

Nonlinear model equation for weakly turbulent premixed flames with realistic fuel expansion is proposed. The equation describes both the hydrodynamic flame instability and flame response to external turbulence in the regime of flamelets. On the basis of the proposed equation the velocity of turbulent flames is investigated for the cases of both weak and relatively strong turbulence. Comparison of the obtained turbulent velocity to experimental results shows that the model equation contains the essence of a more complete theory of turbulent flame speed.

Journal Article↗
PubMed1992

Lectin histochemistry of sex cord-stromal tumors and small cell carcinoma of the ovaries.

Binding sites of peanut agglutinin (PNA), Ulex europaeus (UEA-1), concanavalin A (Con A), and wheat germ agglutinin (WGA) were localized in 10 granulosa cell tumors, 10 Sertoli-Leydig cell tumors, 4 theca cell tumors, and 5 small cell carcinomas. Con A and WGA reacted positively with the majority of the studied neoplasms. PNA and UEA-1 were persistently negative in the sex cord-stromal tumors (SCST) but showed focal positivity in small cell carcinomas. Negative reactions of SCST with PNA and UEA-1 may serve for differentiation between them and common epithelial tumors that are usually PNA and UEA-1 positive.

Binding Sites↗
PubMed1991

Lectin binding to common epithelial tumors of the ovaries.

Binding sites of peanut agglutinin (PNA), Ulex europaeus (UEA-1), wheat germ agglutinin, concanavalin A, and Ricinus communis were localized in 46 common epithelial ovarian tumors. Binding pattern of serous cystadenomas showed significant similarity with the pattern seen in the epithelium of fallopian tubes. Lectin affinity of endometriosis and endometrioid tumors was similar to normal endometrium in secretory phase. Binding pattern of clear cell carcinomas was similar to gestational endometrium, with PNA and UEA-1 showing strong affinity. This pattern is in contrast to clear cell carcinomas of the kidney, that do not bind PNA and UEA-1. Mucinous cystadenomas exhibited binding patterns identical with cervical epithelium. Malignant counterparts of the described tumors were characterized by the partial loss of lectin binding and uneven distribution of the binding reaction.

Adenocarcinoma↗
PubMed1990

MR imaging of uterine carcinoma: correlation with clinical and pathologic findings.

Thirteen patients with clinical stages I and II endometrial carcinoma were examined with magnetic resonance (MR) imaging before surgery. Depth of invasion and stage of disease were assessed, and the results were compared with those from MR images of the surgical specimens and pathologic findings. Staging with MR imaging was accurate in 11 of 13 patients (85%). Our results agree with previous reports that MR imaging is an accurate, noninvasive method of assessing depth of myometrial invasion and cervical involvement. We anticipate that MR imaging will have an increasing role in treatment of patients with endometrial carcinoma.

Aged↗
PubMed1990

Ovarian pathology in chronic pelvic inflammatory disease.

One hundred and sixty-six ovaries of the women of childbearing age suffering from chronic pelvic inflammatory disease (PID) were studied histologically and compared with normal ovaries. The number of mature follicles, cystic atretic follicles, follicular cysts, corpora lutea of menstruation, regressing corpora lutea, and corpus luteum cysts were calculated for each ovary. The main difference between ovaries in chronic PID and normal controls was increase in the number of cystic follicles and follicular and corpus luteum cysts in PID. This phenomenon is explained by the altered blood supply in PID-involved ovaries covered by adhesions containing numerous blood vessels. Chronic PID did not influence the growth of follicles, and their ability to ovulate.

Adult↗
PubMed1988

Tumor of the tongue containing heterotopic brain tissue.

A polypoid tumor containing astrocytic glia and ependyma was excised from the base of the tongue of a 3-month-old infant. Neuroid elements were identified immunocytochemically and by means of electron microscopy. We attribute this rare anomaly to displacement of brain tissue in early embryogenesis before closure of the palate.

Astrocytes↗
PubMed1987

Histochemical study of lectin binding to gestational endometrium.

Avidin-biotin-peroxidase labeling technique was used to localize the binding sites of concanavalin A, peanut agglutinin, and Ulex europaeus in 30 formalin-fixed paraffin-embedded samples of gestational endometrium in intrauterine and ectopic pregnancy, in comparison with 23 samples of normal endometrium at different stages of the menstrual cycle. Concanavalin A shows strong affinity to decidual cells; in normal endometrium its affinity to stroma is weak to moderate. Ulex europaeus, which is weakly positive in normal endometrium, demonstrates focal strong reaction with epithelium and intraluminal secretions in some of the gestational glands. Peanut agglutinin is the most remarkable marker of pregnancy-related changes in endometrium, being strongly positive in the apical portions and intraluminal secretions of the glands; in nonpregnant endometrium its binding capacity is weak.

Abortion, Spontaneous↗
PubMed1987

Massive ovarian edema. Four cases and some pathogenetic considerations.

Four cases of massive ovarian edema (MOE) with symptoms persisting for 6 months and even up to 4 years are presented. No stromal changes other than edema were found histologically, and no functional anomalies were detected clinically. The reported cases are compared with the published data on MOE with stromal changes (fibromatosis, thecal hyperplasia, luteinization), concluding that there are at least two types of MOE: primary (without concomitant pathology), and secondary (superimposed on already altered ovaries).

Adult↗
PubMed1986

Lectin binding to normal, dysplastic, and neoplastic cervical epithelium.

Avidin-biotin-peroxidase labeling technic was used to localize the binding sites of Concanavalin agglutinin (Con A), Ricinus communis (RCA-I), Ulex europaeus (UEA-I), and Limus flafus (LFA) in the cervical epithelia afflicted with condyloma (2 cases), moderate dysplasia (6), severe dysplasia (3), carcinoma in situ (9), squamous cell carcinoma (18), adenosquamous carcinoma (2), adenocarcinoma (1), and glassy cell carcinoma (1). Normal squamous epithelium displayed binding sites predominantly located on the cellular membranes for all the tested lectins except UEA. Normal glandular epithelium showed cytoplasmic localization of the lectins. Neoplastic transformation of squamous epithelium was associated with an increased intensity of the reaction and the appearance of the binding sites in the cytoplasm. UEA binding has changed from negative in normal epithelium to moderately positive in dysplasia and strongly positive in carcinoma. Invasive squamous carcinomas demonstrated an extremely variable pattern of lectin binding, some with very high intensity, allowing easy recognition of malignant cells even in minute metastatic foci.

Adenocarcinoma↗
PubMed1986

Lectin binding to normal human endometrium.

Avidin-biotin-peroxidase labelling technique was used to localize the binding sites of peanut agglutinin (PNA), Ulex europaeus (UEA-I), wheat germ agglutinin (WGA), concanavalin A (Con A), and Ricinus communis (RCA-I) in 30 samples of endometrium at different stages of the menstrual cycle and in early pregnancy. PNA and UEA-I exhibit weak binding to the apical portions of epithelial cells in proliferative and secretory phases, but become strongly positive in pregnancy. WGA and RCA-I show weak binding to glandular epithelium in the proliferative phase, but increase their affinity in the secretory phase. Con A demonstrates strong affinity to decidual cells.

Concanavalin A↗
PubMed1986

Wheat germ and peanut agglutinin binding to normal, dysplastic and neoplastic cervical epithelium.

Binding of wheat germ agglutinin (WGA) and peanut agglutinin (PNA) was studied cytochemically in 43 cervical specimens covering a range of lesions from moderate atypia to invasive carcinoma. Normal squamous epithelium showed weak binding of WGA and negative reaction with PNA. Atypical squamous epithelium was characterized by moderate binding of WGA and PNA, while malignant lesions demonstrated strong affinity to both lectins. In adenocarcinoma in situ, WGA and PNA binding was reduced by comparison with normal glandular epithelium, that was strongly positive.

Adenocarcinoma↗
PubMed1986

Plexiform leiomyoma in endometrial curettings.

A tumor found in endometrial curettings of a 35-year-old woman was originally interpreted as malignant. Review of the slides and additional curettings revealed that the tumor was in reality a plexiform leiomyoma. Attention is drawn to the fact that this rare tumor may be present in endometrial curettings.

Adult↗
PubMed1984

Ovarian androblastoma metastatic to tonsil.

Structural pattern of a tonsillar tumor found in a 67-year-old female was similar to a small ovarian androblastoma diagnosed histologically 6 1/2 years earlier. Electron microscopic study of the tonsillar mass revealed crystalloid structures suggestive of the Leydig cell origin of the tumor. After tonsillectomy, there was no local recurrence of the tumor, but the patient died a year later of multiple metastases. There appeared to be no previous reports of ovarian tumors metastatic to tonsil, and malignant androblastomas of the Leydig cell type are extremely rare.

Female↗
PubMed1984

Immunocytochemical localization of keratin in normal, dysplastic and neoplastic cervical epithelium.

The PAP immunocytochemical technique utilizing specific keratin antibody was applied to paraffin sections from 36 cervical biopsies. Normal squamous epithelium and condylomas had similar patterns of keratin production with intense staining of intermediate and upper layers, while basal cells remained negative. Dysplasia, carcinoma in situ and infiltrating squamous carcinoma showed uneven distribution of keratin with the least amount seen in the areas with high mitotic rate and anaplasia. All large cell squamous carcinomas demonstrated presence of significant amounts of keratin. Squamous carcinomas of the small cell type were essentially keratin-free.

Adenocarcinoma↗
PubMed1983

Immunocytochemical localization of carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), and human chorionic gonadotropin (HCG) in cervical neoplasia.

Sixty-one cases of invasive cervical carcinoma and 40 cases of dysplasia and carcinoma in situ were studied by peroxidase-antiperoxidase method (PAP) for the presence of carcinoembryonic antigen (CEA). Forty-two cases (13 carcinomas in situ and 29 invasive carcinomas) also were tested for alpha-fetoprotein (AFP) and human chorionic gonadotropin hCG. CEA was not detected in normal cervical epithelium but was present in 90% of the neoplastic lesions. Not mere presence, but a pattern of CEA tissue distribution emerged as the main differential point between noninvasive and invasive lesions. Twenty-nine of 51 invasive squamous carcinomas (57%) contained CEA-positive cells at the stromal edge of epithelium, while this feature was not found in dysplasia and carcinoma in situ. Adenocarcinomas and adenosquamous carcinomas all were positive for CEA, while clear-cell carcinomas were negative. AFP was present only in a case of poorly differentiated adenosquamous ("glassy cell") carcinoma. hCG has not been revealed in any of the tumors.

Adenocarcinoma↗