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Biomedical subjects

W Gorczyca

Publications and source records attributed to W Gorczyca.

At least 73 records · Page 4Linked to original sources
PubMed1989

Cell surface sialic acid affects immunoglobulin binding to macrophages.

We demonstrate that guinea pig peritoneal macrophages pretreated with neuraminidase from Vibrio cholerae bind more 125I-IgG than non-treated cells. Estimation of binding constants (Ka and Bmax) shows that the elevation of binding is the result of an increase in affinity and not in the number of receptors for IgG. The change of affinity is proportional to amounts of sialic acid liberated from the cells by increasing doses of neuraminidase. It is also shown that affinity of interactions of IgG with the macrophage receptor is pH dependent. These results indicate that electrostatic forces are important for IgG binding to the macrophage Fc gamma R. The IgG-Fc gamma R interaction can be modulated by changing the degree of sialylation of the macrophage surface glycoconjugates.

Animals↗
PubMed1989

Expression of ras oncogene p21 protein in early gastric carcinoma and adjacent gastric epithelia.

The expression of the ras gene product p21 in normal gastric mucosa, early gastric carcinoma of diffuse (gastric) and intestinal types, and in adjacent mucosal abnormalities is reported. The analysis was performed on paraffin sections by an immunohistochemical assay using the mouse monoclonal antibody RAP-5 and the rat monoclonal antibody Y13-259. Expression of ras p21 was assessed by staining intensity and percentage of positively stained cells. In comparison to normal gastric mucosa of non-cancer patients, p21 was overexpressed in nearly all early carcinomas of both types and in the dysplastic and/or metaplastic mucosal alterations accompanying intestinal type of gastric cancer. Increased p21 expression was also observed in the normal-appearing mucosa adjacent to early carcinomas of diffuse type, but not in the morphologically normal gastric epithelium adjacent to the intestinal type. The results of this investigation suggest that ras p21 overexpression may be related to early events of human gastric carcinogenesis. The study supports the notion of different pathways in the development of diffuse (gastric) and intestinal types of gastric carcinomas.

Adenocarcinoma↗
PubMed1989

Expression of ras oncogene p21 protein in relation to regional spread of human breast carcinomas.

The oncogenes most frequently detected in human tumors belong to the ras gene family (Ha-ras, Ki-ras, and N-ras). These genes encode a group of closely related 21,000 dalton proteins termed p21. An immunohistochemical study of ras p21 expression was carried out on paraffin sections of 54 human breast carcinomas using monoclonal antibodies to p21. The control group consisted of ten cases of benign fibrocystic disease. The p21 expression was significantly higher in cancer cells than in epithelial cells of control specimens. No correlations, however, were observed between oncogene product expression and tumor size, histologic type, or grade. As a group, tumors with axillary lymph node metastases expressed higher levels of ras p21 than nonmetastasizing tumors. However, because of the significant overlap in individual p21 values, it is unlikely that the immunohistochemical assay for p21 could be used to predict the behavior of mammary carcinomas.

Breast Neoplasms↗
PubMed1989

Wheat germ agglutinin binding sites on human urothelial cells of different grades of transformation.

125I-Wheat germ agglutinin (WGA) binding parameters of human urothelial cell lines of different grades of transformation (TGrII and TGrIII) were compared. The values of association constant (Ka) and the number of binding sites/cell for HCV29 (TGrII) cell line were about 3 x 10(6) M-1 and over 4 x 10(7), respectively. Two TGrIII cell lines, HCV29T and Hu549 revealed lower values for Ka, and considerably higher numbers of binding sites/cell (about 3 x 10(8) and 2 x 10(8), respectively). Binding of 125I-WGA to total cellular proteins resolved by SDS-PAGE and transferred to nitrocellulose showed multiple diffused bands in the range of 58-180 kDa. Some of these bands were characteristic for TGrII cells (124 kDa) or TGrIII cells (135 and 148 kDa).

Animals↗
PubMed1988

Microadenomas of the human pituitary and their vascularization.

During 100 autopsies of patients who had no previous endocrinological problem, selective injections of the pituitary arterial systems were performed. Pituitary glands were examined from 60 male and 40 female patients with an average age of 68 years. Detailed histological and immunocytological studies using peroxidase-antiperoxidase techniques for prolactin (PRL), adrenocorticocotropic hormone (ACTH), follicle-stimulating hormone, thyroid-stimulating hormone, and growth hormone were used. Thirty-three microadenomas were found in 27 patients; 22 were single, 4 were double, and 1 was triple. Fourteen were nonreactive to immunostaining, 10 were reactive to PRL, and 9 were reactive to ACTH. Their diameters ranged between 0.5 and 5.0 mm, and they were located mainly in the lateral wings and the peripheral zone of the anterior pituitary gland. Microvascular study revealed that 22 microadenomas (66%) had direct extraportal arterial supplies. Because the hypothalamic factors are transported to the anterior lobe through the portal vessels, this study suggests that the formation of microadenomas occurs most frequently outside the hypothalamic-hypophyseal portal system and further supports the hypothesis that pituitary adenomas may arise de novo without the influence of hypothalamic factors.

Adenoma↗
PubMed1987

Microvascular anatomy of Heubner's recurrent artery.

The microvascular anatomy of Heubner's recurrent artery (RAH) was studied in 50 human brains (100 hemispheres) using acrylic paint under the operative microscope. The recurrent artery of Heubner was always found as a single vessel in 28 cases (28%) and multiple vessels in 72% (double vessels in 48%, triple in 23% and quadruple in 1%). Altogether 197 RAH were found in 100 hemispheres, averaging 1.97 arteries per hemisphere. In 44 instances, it originated from the proximal part of the A1-segment of the anterior cerebral artery. The diameters of the RAH ranged from 0.4 to 1.5 mm. Their vascular territory was variable. Four groups of distributing branches were found in the RAH: frontal and hypothalamic, olfactory, perforating and sylvian-fissure branches. In 12 hemispheres, anastomoses were found between the perforating branches of the RAH and the middle cerebral artery. In five cases (5%) anastomoses were present between the perforating branches of the MCA and the olfactory branch of the RAH. In one case (1%), an anastomosis was found between two RAH.

Cerebral Arteries↗
PubMed1987

Anatomy of diaphragmatic circulation.

The diaphragmatic circulation was studied in 48 mongrel dogs weighing 10-35 kg by injecting acrylic coloring into the arteries and veins of the diaphragm. The phrenic arteries and internal mammary arteries were found to anastomose head to head, forming an internal arterial circle around the medial leaflet of the diaphragm tendon. This arterial circle emitted vascular branches that traveled between muscle fibers toward the periphery of the diaphragm. These branches anastomosed with vessels of the intercostal arteries to form costophrenic arcades all along the fibers of the crural and costal diaphragms. The intercostal arteries were anastomosed to one another by small vessels within the muscular diaphragm, thus forming an arterial ring around the insertions of the diaphragm on the ribs. The venous drainage has an anatomic distribution similar to that observed on the arterial side, but with the additional presence of valves that could play a role in directing blood flow.

Animals↗
PubMed1987

Observations and analysis of results in 131 cases of spasmodic torticollis after selective denervation.

In 131 patients treated exclusively by selective denervation during the past 10 years, all or almost all the abnormal movements of spasmodic torticollis were suppressed in 115 (88%) while preserving posture and mobility. This approach was also used in certain forms of adult-onset dystonia. An appreciable amount of abnormal movements remained in the other patients, either due to residual innervation or because of limitation of denervation necessary to preserve normal movements (laterocollis) or neck stability (retrocollis). A medio-lateral approach to the posterior cervical region in the sitting position using stimulation under light anaesthesia is recommended.

Humans↗
PubMed1987

Arterial supply of the human anterior pituitary gland.

The vascular anatomy of the anterior lobe (AL) of 182 previously injected human pituitary glands was examined. Three different techniques of injection using India ink and acrylic paints were performed to establish a direct arterial supply to the AL. In 81% of the cases, end-arteries were found in the AL. Their participation in the vascularization of the adenohypophysis is variable from a small subcapsular area to almost the entire lateral parts of the AL. Arteries playing some role in the perfusion of the AL are subdivided into infra- and supradiaphragmatic, according to their topography in relation to the diaphragma sellae. Evidence of the presence of end-arteries in the AL is in disagreement with the generally accepted concept of a purely portal supply to this part of the pituitary gland.

Adolescent↗
PubMed1986

Immunoglobulins of colostrum--VI. Comparative studies of cytophilic properties of bovine serum and colostral IgG.

In our previous studies, using physical-chemical and serological methods, substantial differences between bovine serum and colostral IgG, especially IgG2, have been shown. The structural differences were localized in the Fc region of immunoglobulins studied. The present comparative studies were undertaken to determine whether structural differences in the Fc region of bovine serum and colostral IgG are reflected in the interaction of these immunoglobulins with the guinea-pig peritoneal macrophage Fc gamma receptor. It was found that binding of bovine serum and colostral IgG1 was a saturable process and only quantitative differences in the mode of binding to the Fc receptor were observed. There is, however, a big difference in cytophilic activity of bovine IgG2--no saturable and reversible binding is observed in the case of bovine serum IgG2.

Animals↗
PubMed1983

Guinea-pig peritoneal macrophage receptor for IgG--II. Purification of the receptor and its partial characterization.

The Fc gamma receptor of guinea-pig peritoneal macrophages was purified by affinity chromatography by using rabbit IgG or guinea-pig IgG2 coupled to Sepharose. Lysates prepared by treatment of 125I-labeled macrophages with NP-40 were first applied to BSA-Sepharose and then to IgG-Sepharose and eluted with 0.5 M acetic acid containing 1% NP-40. The specific binding was determined by interaction of the 125I-labeled receptor with IgG-Sepharose in the presence and absence of soluble IgG. The specific binding of the purified receptor was 42-82%. Interactions of the purified receptor with IgG-Sepharose were equally well inhibited by soluble rabbit IgG or guinea-pig IgG2, but not by F(ab')2 fragments. Inclusion of NP-40 in the buffer used in the assay reduced nonspecific binding of the receptor to the affinity gels. The purified receptor can be stored for 20 days at 4 degrees C without a significant loss of the specific binding activity. Analysis of the receptor by SDS-polyacrylamide gel electrophoresis, under nonreducing and reducing conditions, revealed two major peaks of radioactivity corresponding to mol. wts of about 50,000 and 25,000, and one very minor peak corresponding to a mol. wt of about 30,000. The results obtained suggest that the protein of the second major peak is a product of the dissociation of the protein of the first major peak rather than a product of its reduction by 2-mercaptoethanol.

Animals↗
PubMed1982

Fetal cephalostat.

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Cephalometry↗