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Biomedical subjects

G Szekeres

Publications and source records attributed to G Szekeres.

At least 19 recordsLinked to original sources
PubMed1995

Effect of ribonuclease A and deoxyribonuclease I on immunostaining of Ki-67 in fixed-embedded sections.

Immunostaining of the cell cycle-associated Ki-67 antigen was studied on routinely formalin-fixed and paraffin-embedded tissue sections, using the Ki-67-specific monoclonal antibody MIB-1. Immunomorphological analysis of the Ki-67 immunostaining pattern was carried out following tissue pre-treatments including combinations of microwave heating and trypsinization, as well as of ribonuclease and deoxyribonuclease pre-digestion of the sections. The nucleolar Ki-67 immunostaining after slide pre-treatment by microwave heating followed by trypsinization was reduced only by ribonuclease pre-digestion, if this latter was used before heating. Ki-67 immunostaining was not significantly reduced by deoxyribonuclease treatment. We conclude that Ki-67, located in the nucleoli, may be associated there with nucleolar RNA.

Deoxyribonuclease I↗
PubMed1994

Hapten-mediated identification of cell membrane antigens using an anti-FITC monoclonal antibody.

A monoclonal anti-FITC antibody (F4/1) was produced and demonstrated to be specific for both the free and protein-conjugated (either soluble or cell-bound) form of fluorescein, or carboxyfluorescein. When mouse thymocytes were labelled with a novel fluorescein derivative 5(6)-carboxyfluorescein succinimidyl ester (CFl-NSE), the incorporation of fluorescein was predominantly membrane-bound as demonstrated immunohistochemically. The coupling of CFl-NSE to cells displays a random distribution pattern as shown by immunoblotting of cell extracts prepared by detergent solubilization of CFl-NSE-labelled thymocytes. In addition, the Thy-1.2 antigen immunoprecipitated from a CFl-NSE-labelled thymocyte lysate with a rat monoclonal antibody (Mab) could be detected using the anti-FITC Mab. The molecular weight of the immunoprecipitated material could be estimated immediately by reference to the FITC-labelled molecular weight markers electrophoresed simultaneously.

Animals↗
PubMed1994

Bone marrow one step fixation-decalcification in Lowy FMA solution: an immunohistological and in situ hybridization study.

The immunoreactivity of paraffin embedded bone marrow biopsies (BMB) was studied following a one step 20-hour-fixation-decalcification in Lowy formalin mercuric chlorid acid solution which permits excellent histological stainings. Antibodies reactive with myeloid, megakaryocytic, erythroid cells, T and B lymphocytes, mastocytes and metastatic cells were compared. Nearly all antibodies working on paraffin sections were demonstrated on Lowy FMA fixed BMB. Special care was taken to define an optimal working dilution. Trypsinization was not necessary. A slide microwave pre-treatment appeared essential before testing CD20 L26, CD8, CD3, CD34, MB1 Kappa and Lambda antibodies. It was suitable for UCHL1, LN2, CD30 antibodies. The same fixative allowed an m RNA Kappa or Lambda in myeloma and EBER 1 EBV RNAs in HIV lymphoma visualization by in situ hybridization. The safety handling of the toxic mercuric chloride component is discussed.

Biopsy↗
PubMed1994

Ki-67 and p53 expression in cutaneous Bowen's disease: an immunohistochemical study of fixed-embedded tissue sections.

The monoclonal Ki-67-specific MIB-1 and p53 protein-specific DO-1 antibodies were used to identify proliferating cell fractions on microwave-pretreated paraffin sections of 7 cutaneous Bowen's disease specimens. A high Ki-67 score was characteristic of all cases examined, and significant p53-positivity was seen in 4 cases. In the peritumoral, histologically normal epidermis, Ki-67- and p53-positive cells were frequently present, in one case with very high scores (89% as well as 82%, respectively). These findings indicate an increase in the proliferative activity of the Bowen cells (high Ki-67 score) and that p53 mutations are frequently found in this disease. The p53 expression was not related to the Ki-67 score. The expression of Ki-67 and p53 in morphologically normal epidermal cells is also discussed. The histologically normal epidermal cells expressing p53 and Ki-67 antigens may correspond to pre-malignant clones.

Antigens, Neoplasm↗
PubMed1994

[Immunohistochemical characterization of a median raphe cyst of the penis].

Cysts and canals found on the ventral surface of the penis have been ascribed to minor dysembryoplasia of the male genitalia. These lesions occur almost exclusively on the ventral surface of the penis along the median raphe and can extend from the urethral meatus to the anus. They are lined by stratified urothelium or squamous epithelium and they do not communicate with the urethra. Most cases are noted in early adulthood, they are usually asymptomatic but may become infected. Surgical removal is the adapted treatment. In this report we describe a case in which the urothelial origin of the cyst was documented by immunohistochemistry for cytokeratin 13.

Adult↗
PubMed1993

Isolation and characterization of two new monoclonal antibodies against the CD34 molecule.

Two new monoclonal antibodies, Immu-133 and Immu-409, were raised against the human acute myelogenous leukemia cell line (KG-1a) and human immature erythroleukemic cells (TF1). These monoclonal antibodies were isolated from two different fusions of mouse myeloma cells with mouse splenic lymphocytes. The immunofluorescence studies performed on various target cells showed that these antibodies recognized a surface antigen expressed selectively on KG-1a, TF1 cells and on human hematopoietic progenitor cells. They also stained endothelial cells used in immunochemistry both in frozen and paraffin embedded tissue sections. Immu-133 and Immu-409 immunoprecipitated a KG-1a cell surface protein with an apparent molecular weight of 110-115 Kd. Competitive binding assays performed with a panel of referenced CD34 monoclonal antibodies revealed that Immu-133 and Immu-409 are monoclonal antibodies restricted to different epitopes of the CD34 molecule.

Animals↗
PubMed1990

Reactivity of lymphocytes to a progesterone receptor-specific monoclonal antibody.

In this study we present evidence for reactivity of pregnancy lymphocytes, but not nonpregnancy lymphocytes, with the progesterone receptor-specific monoclonal antibody mPRI. Using an avidin-biotin peroxidase detection system, we found a nuclear staining in 14.6 +/- 3.7% (mean +/- SEM, N = 27) of pregnancy lymphocytes, while only 0.47 +/- 0.33% (mean +/- SEM, N = 15) of nonpregnancy lymphocytes reacted with the antibody. To characterize the receptor-bearing subset, CD8+ and CD4+ cells were depleted by complement-dependent lysis. Depletion of CD8+ cells was accompanied by 62 +/- 18% loss of progesterone receptor-bearing cells, while depletion of CD4+ cells resulted in a twofold increase in the number of positively staining lymphocytes. In nonpregnancy lymphocytes a 3-day PHA treatment, as well as allogeneic stimulation, resulted in a significant increase in the number of receptor-containing cells. These results suggest that pregnancy, but not nonpregnancy, lymphocytes contain progesterone binding structures, and that these are inducible by mitogenic or alloantigenic stimuli.

Antibodies, Monoclonal↗
PubMed1989

Immunohistological demonstration of lymph node reticulum cells in the acquired immunodeficiency syndrome related complex. A study in Bouin-fixed tissues.

The results of an immunohistochemical study on paraffin sections of the lymph nodes from 5 patients with the acquired immunodeficiency syndrome (AIDS) related complex (ARC) are presented. The distribution and frequency of follicular dendritic cells (FDC) and of interdigitating cells (IDC) were examined with the monoclonal antibodies J3D3 (directed against the C3b complement receptor, CD 35) and IOB1a (specific for the C3D, CD21) as well as with the polyclonal anti-S-100 protein antiserum in Bouin-fixed, paraffin-embedded sections using a Streptavidin-biotin-peroxidase technique. Disruption of the follicular FDC network was demonstrated. No major alteration of the IDC was noted. The immunomorphological patterns observed in this study were comparable with the previously reported lymph node alterations studied in frozen section.

AIDS-Related Complex↗
PubMed1989

Lymph node interdigitating cell granuloma associated with non-Hodgkin's malignant lymphoma. A case report and review of the literature.

We report a new case of histiocytic proliferation, which histologically resembles histiocytosis X, in a lymph node affected by non-Hodgkin's malignant lymphoma. This brings the total number of such reported cases to 12. Histiocytosis X cells, with folded nuclei, expressed S100 protein and an antigen recognized by anti-CD1 monoclonal antibodies. Ultrastructural study did not show any Birbeck granules and demonstrated a morphology similar to that of interdigitating cells. In the absence of Birbeck granules, the term 'Langerhans' cell granulomatosis' is not correct and should be replaced by either 'interdigitating cell granuloma' according to immunohistochemistry and ultrastructure or 'histiocytosis X-like granuloma' according to optical morphology. The fact that some cells with folded nuclei were positive for lysozyme argues in favor of the existence of transitional cells between histiocytes hnd interdigitating cells. The 11 other reported cases were reviewed. In 6 cases, this type of granuloma was associated with B cell lymphoma. In 3 cases the lymphoma was also probably of B cell type. In 2 cases, no information could be found. We could speculate that these histiocytosis X-like lesions are reactive, resulting from immune disturbances due to the lymphoma and/or the treatment.

Aged↗