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J Hunyadi

Publications and source records attributed to J Hunyadi.

At least 37 records · Page 2Linked to original sources
PubMed1998

Consistent polymerase chain reaction-single-strand conformation polymorphism pattern of human herpesvirus-8 in the course of classical Kaposi's sarcoma assumes its clonal origin.

There is emerging evidence that Kaposi's sarcoma-associated herpesvirus (KSHV or HHV-8) has a central role in the pathogenesis of Kaposi's sarcoma (KS). The occurrence of HHV-8 in classical KS biopsies is reported irrespective of its clinical stage (patch, plaque, nodular). HHV-8 was detected in 25 of 28 formalin-fixed paraffin-embedded classical KS samples by nested polymerase chain reaction. In addition, in six patients multiple tumors were available (n = 21). Single-strand conformation polymorphism (SSCP) analysis of the amplicons showed uniform SSCP pattern of samples belonging to the same patient regardless of whether the KS was multiplex or developed again years after the first excision. Most of the SSCP patterns were confirmed by further sequence analysis. The presence of the same sequence variant of HHV-8 in various samples of the same patient supports the clonal origin of classical Kaposi's sarcoma.

Herpesvirus 8, Human↗
PubMed1997

bcl-2 vs p53 protein expression and apoptotic rate in human nonmelanoma skin cancers.

BACKGROUND: A failure in the apoptotic response after severe genomic damage could facilitate cell transformation and tumor development, and a constitutive overexpression of either p53 or bcl-2 protein in nonapoptotic tumor cells could signify a defective bax-mediated apoptosis. OBJECTIVES: To investigate whether a negative correlation occurs between these 2 proteins in nonmelanoma skin cancer and whether overexpression of either protein is associated with a low rate of spontaneous apoptosis. DESIGN: Immunohistochemical study of nonmelanoma skin cancer archive material. SETTING: University referral center. PATIENTS: White patients with tumors on sun-exposed skin areas (ie, 17 basal cell carcinomas and 22 squamous cell carcinomas). MAIN OUTCOME MEASURES: Positivity for p53 and bcl-2 were scored semiquantitatively on 4 levels, and the percentages of apoptotic cells were determined. RESULTS: A significant negative correlation between p53 and bcl-2 expression was found in the basal cell carcinomas, but not in the squamous cell carcinomas, largely attributable to the low level of bcl-2 staining in the squamous cell carcinomas. Squamous cell carcinomas have a significantly higher number of apoptotic cells than basal cell carcinomas: 1.1% vs 0.6%, respectively. This spontaneous apoptosis decreases with increasing bcl-2 (in basal cell carcinoma), whereas it does not appear to be related to p53 level expression. CONCLUSIONS: These results indicate that a disturbance in either p53 or bcl-2 suffices to enhance skin tumor formation by suppressing apoptosis; bcl-2 appears to reduce the rate of spontaneous apoptosis, but an aberrant p53 expression does not, and this factor may solely affect the apoptosis from exogenous genotoxicity.

Apoptosis↗
PubMed1996

Repopulation of Langerhans cells during wound healing in an experimental human skin/SCID mouse model.

The epidermal repopulation of Langerhans cells (LCs) during wound healing was examined using a human skin severe combined immunodeficient (SCID) mouse model. The experiments, were carried out after proving the human origin of keratinocytes repopulating the wound beds using the W6/32 monoclonal antibody. It was shown that CD1a- and HLA-DR-positive dendritic cells (mostly LCs) are already detectable 2 days after injury within the newly formed epithelium. In the excisional wounds investigated, neither HLA-DR nor ICAM-1 expression of human keratinocytes was observed. Our present data suggest that LC repopulation is an early event in the process of re-epithelization.

Animals↗
PubMed1996

Thrombospondin receptor (CD36) expression of human keratinocytes during wound healing in a SCID mouse/human skin repair model.

Using a human skin/severe combined immunodeficient (SCID) chimeric mouse model, we examined the keratinocyte expression of the thrombospondin receptor (CD36) and its ligand thrombospondin-1 (TSP1) in acute uninflamed wounds. Positive suprabasal keratinocyte expression of CD36 was observed as early as 30 minutes after wounding in the adjacent, intact epidermis; it disappeared 4 days later. Keratinocytes of the freshly re-epithelised wounds and those of the surrounding epidermis remained TSP1-negative throughout the whole observation period of 7 days. Our results indicate that CD36-positive keratinocytes, probably in connection with activated, TSP1-positive thrombocytes, may play an important role in the early phase of wound healing.

Animals↗
PubMed1995

[Immunologic studies in chronic urticaria].

Chronic urticaria is considered to be a heterogeneous disease, which can be divided into several subclasses. The authors investigated 126 patients suffering from chronic urticaria with 41 of unknown origin. The aim of the present study was to work out a strategy for the complete investigation of patients with chronic urticaria. The findings of the immunological study modified the results obtained by medical assessment of the 126 chronic urticaria cases, diminished the number of the patient with chronic urticaria unknown etiology.

Adolescent↗
PubMed1994

[Skin as an immune system].

Skin consists of three structurally and functionally distinct compartments containing resident and nonresident cells. These cells cooperative with humoral pathway of immune system in defence of healthy skin. Resident and nonresident cells are able to initiate inflammatory or immune processes of skin, although interstitial reactions (activation by bacteria, immunoglobulin or complement) also take place in such processes. In normal conditions nonresident cells can migrate through vascular endothel, however, PMN granulocytes and B lymphocytes cannot. Resident and nonresident cells of skin are capable of exerting a wide range of immunomodulatory effects, among them keratinocytes are of distinguished significance producing arachidon metabolites and IL-1 as well. Activated skin cells might induce chemotactic migration of distinct white blood cells normally absent or only a few cells being present in healthy skin. Cell migration into the interstitial space of skin is mediated by adhesion molecules expressed on cell surface of migrating cells, vascular endothel cells and on keratinocytes. Composition and density of adhesion molecules vary by type of stimuli, therefore various cytokines might induce distinct reactions mediated by certain population of cells. In addition, initiation and progress of immune- or inflammatory reactions are determined by the involved cell-populations as well. Normal regulation provides appropriate control and termination of the reaction, however, uncontrolled regulation results in development of pathological state.

Adjuvants, Immunologic↗
PubMed1994

[Functional study of the regeneration of nerve fibers after keratinocyte transplantation].

The functional regeneration of sensory nerves was investigated in 5 patients with skin defects (caused by leg ulcers, a burn or fasciitis necrotisans) after transplantation with a keratinocyte suspension. In this area, first the pain sense and soon after wards the cold and heat sense returned, followed finally by the flare reaction caused by the mustard oil test. No sweat production could be observed during the study, because sweat glands were not found after the keratinocyte transplantation. The reinnervation course is roughly the same for skin defects covered with split skin graft or with a keratinocyte suspension.

Adult↗
PubMed1994

Chemotaxis of freshly separated and cultured human keratinocytes.

It is generally accepted that keratinocyte migration plays a critical role in the process of wound healing. A study was therefore made of the migratory response of freshly separated and cultured human keratinocytes to factors with chemotactic properties for a variety of cells. Interleukin-1 alpha (IL-1 alpha), interferon-gamma (IFN-gamma), interleukin-8 (IL-8), and tumour necrosis factor alpha (TNF-alpha) were tested for their chemotactic effectiveness in a modified Boyden chamber assay. IFN-gamma, IL-1 alpha and IL-8 were demonstrated to serve as chemoattractants for freshly separated keratinocytes. For cultured cells, however, only IFN-gamma was found to display chemotactic properties. The findings demonstrate that there is significant difference between the chemotactic behaviour of freshly separated and cultured cells.

Cells, Cultured↗
PubMed1994

Expression of thrombospondin-1 (TSP1) and its receptor (CD36) in healthy and diseased human skin.

In the present study, an analysis was made of the expression pattern of thrombospondin-1 (TSP1) and its receptor (CD36) in skin biopsies obtained from healthy volunteers and from patients with lichen planus, lupus erythematosus, cutaneous T-cell lymphoma and psoriasis vulgaris. Using monoclonal antibodies against TSP1 in biopsies from the healthy volunteers and from both clinically involved and uninvolved skin of the patients, a specific peroxidase-positive reaction was detected around the sweat glands in the dermis. In all cases investigated, the CD36-positive lesional keratinocytes remained TSP1-negative. These findings favour the hypothesis that CD36-positive keratinocytes might have some functional relevance via oxidized low-density lipoprotein and/or collagen fibrils, without any connection with TSP1.

Antigens, CD↗
PubMed1993

Platelet-activating factor antagonists (BN 52021 and BN 50730) inhibit tumor necrosis factor-alfa-mediated cytotoxicity on murine L929 tumor cells.

Tumor necrosis factor (TNF)-alfa has been described as a mononuclear phagocyte-produced cytotoxin that causes the necrosis and regression of some tumors. The mechanism of the cytotoxicity and the basis for the differential cytotoxic effects of TNF against cells of various origin remains unclear. It has also been reported, that murine TNF stimulates the production of platelet-activating factor (PAF) by cultured peritoneal macrophages, and that PAF enhances TNF production by alveolar macrophages. Furthermore, it is known that the synthesis and release of PAF are inhibited by plasma proteinase inhibitors. This study was devoted to investigate the effects of two specific PAF antagonists (BN 52021 and 50730), and a proteinase inhibitor (aprotinin; GordoxR) on the TNF-induced cytotoxicity in L929 murine fibroblasts. Our present findings indicate that TNF-induced cytotoxicity is inhibited in a dose-dependent manner by the PAF antagonists studied and by the kallikrein inhibitor aprotinin. These findings provide further evidence suggesting that PAF might be involved in the process of the TNF-alfa-induced cytotoxicity of L929 mouse fibroblasts.

Animals↗
PubMed1993

Expression of monocyte/macrophage markers (CD13, CD14, CD68) on human keratinocytes in healthy and diseased skin.

The results of several investigations proved that, in special circumstances, human keratinocytes (HKs) synthesize and express cell surface moieties characteristic of effector and/or accessory cells of the immune system, such as CD16, CD36, HLA-DR, and intercellular adhesion molecule-1 (CD54), which are all detectable on the surfaces of macrophages. In the present study, skin biopsies from healthy volunteers, from positive tuberculin skin tests, and from patients with acute urticaria (AU), lichen planus (LP), psoriasis vulgaris (PV), mycosis fungoides (MF), and purpura pigmentosa chronica (PPC) were investigated by means of a multistep immunoperoxidase method to examine the reactivity of the HKs with a panel of monoclonal antibodies (MABs) characteristic of monocyte/macrophage cell lines. In biopsies obtained from positive tuberculin tests and from clinically involved skin of patients with LP, PV, MF, or PPC, a multifocal, positive peroxidase reaction was observed on the membranes of HKs of the basal and suprabasal cell layers when the MABs OKM13 (CD13), OKM14 (CD14), and Dako-Macrophage (CD68) were used. In contrast, specific staining of the HKs was not observed with the same antibodies in the biopsies of healthy volunteers or of patients with AU or in the uninvolved skin specimens obtained from the other patients. The HKs of PV, LP, MF, PPC, and AU patients and those of the healthy subjects all failed to give positive reactions when MABs against CD11b, CD15, or CD33 were used. The published data supplement the known surface characteristics of HKs, reflecting their stage of activation and differentiation.

Antigens, CD↗
PubMed1993

Macrophage markers 25F9 and 27E10 on human keratinocytes in normal and diseased skin.

In the present study, an immunohistochemical analysis was made of the expression pattern of different macrophage markers such as 25F9, 27E10 and RM 3/1 on the surface of human keratinocytes (HK) in biopsies obtained from healthy volunteers and from patients with lichen planus, chronic cutaneous graft-versus-host reaction, mycosis fungoides, and purpura pigmentosa chronica. In biopsies from the healthy volunteers and from both clinically involved and uninvolved skin of the patients, the HK of the basal cell layer exhibited a specific peroxidase-positive reaction when the monoclonal antibody against 25F9 was used. Lesional HK from all patients studied displayed 25F9 and 27E10 in nearly the entire epidermis. The present findings provide further evidence that HK and macrophages share a number of common cell surface moieties.

Antigens, Surface↗
PubMed1992

Immune-associated surface markers of human keratinocytes.

The results of a number of investigations have proved that human keratinocytes (HKs) possess the ability to synthesize and express cell surface moieties characteristic of effector and/or accessory cells of the immune system. The present paper summarizes the known immune cell surface features of HKs, reflecting their stage of activation and differentiation. The surface and functional characteristics of HKs suggest their monocyte/macrophage behavior, which fits in well with the presumed active involvement of HKs in the skin immune system.

Antigens, CD↗
PubMed1992

Expression of beta-2 integrin molecules on human keratinocytes in cytokine-mediated skin diseases.

Integrins are cell surface molecules of importance in a wide variety of cellular functions, including morphogenesis, cell migration and cell matrix interactions. The beta-2 (B2) integrin (leukocyte integrin, CD11/CD18) subfamily comprising three members, each consisting of a shared beta subunit (CD18) non-covalently associated with unique alpha subunits (CD11a, CD11b, CD11c). In the present study, we have analysed the expression pattern of B2 integrins on the surface of human keratinocytes (HKs) in biopsies obtained from healthy volunteers, from positive tuberculin skin tests and from patients with acute urticaria (AU), lichen planus (LP), psoriasis vulgaris (PV), mycosis fungoides (MF) or purpura pigmentosa chronica (PPC). In biopsies obtained from positive tuberculin tests and from the clinically involved skin of patients with LP, PV, MF or PPC, a multifocally occurring, suprabasal peroxidase-positive reaction was observed on the membranes of the HKs when the monoclonal antibodies (MABs) Dako CD11a, Dako-p150, 95 or Dako CD18 were used. In contrast, no specific staining of the HKs was observed with the same MABs in biopsies from healthy volunteers, from patients with AU and in the uninvolved skin specimens obtained from the other patients. The HKs from PV, LP, MF, PPC and AU patients and those from the healthy subjects failed to give a positive reaction when the MAB against CD11b (OKM1) was used. Our present findings provide further evidence that HKs may be actively involved in cell adhesion processes.

Antigens, CD↗
PubMed1991

Expression of complement receptor CR2 (CD21) on human subcorneal keratinocytes in normal and diseased skin.

Human keratinocytes are able to synthesize and express cell surface moieties characteristic of effector and/or accessory cells of the immune system (CD16, CD36, HLA-DR, intercellular adhesion molecule-1). In the present study, skin biopsies from healthy volunteers, from patients with psoriasis vulgaris (PV), mycosis fungoides (MF), purpura pigmentosa chronica (PPC), acute urticaria (AU) and from positive tuberculin skin tests were investigated with regard to the reactivity with the monoclonal antibodies to complement receptors CR1 CR2 and CR3 by means of a multistep immunoperoxidase method. In the clinically involved skin of all patients with PV, MF or PPC, and in biopsies obtained from positive tuberculin tests, specific epidermal intercellular staining with OKB7 and Leu anti-CR2 was seen on subcorneal keratinocytes. This finding suggests a differentiation-linked expression of CR2 on human keratinocytes in cytokine-mediated skin diseases whereas CR1 and CR3 are apparently not expressed.

Antigens, CD↗