Search PubMed⌕ Search

Biomedical subjects

S Majewski

Publications and source records attributed to S Majewski.

At least 73 records · Page 4Linked to original sources
PubMed1993

NK-cell activity in patients with HPV16-associated anogenital tumors: defective recognition of HPV16-harboring keratinocytes and restricted unresponsiveness to immunostimulatory cytokines.

Peripheral blood mononuclear cells (PBMC) from patients with active HPV16-associated pre-malignant and malignant anogenital lesions display a significantly decreased NK-cell activity against HPV16-harboring SKv keratinocytes (NK/SKv) while their cytotoxicity against erythroleukemic K562 cells (NK/K562) remains unaffected. A similar defect can also be seen in some healthy individuals displaying no symptoms of HPV infection (low responders). Analysis with specific Leu IIa monoclonal antibodies (MAbs) has revealed that all patients as well as weakly responding control subjects had normal numbers of circulating CD16+ NK cells. However, PBMC from patients with active disease and weakly responding controls displayed a significantly decreased ability to bind SKv cells. Binding of K562 was in the normal range. In patients in whom the lesions were successfully removed or regressed spontaneously (patients with no lesions), NK/SKv activity did not differ from that of normally responding healthy subjects and the ability of their PBMC to bind SKv cells was unaffected. To determine whether an abrogated NK/SKv cytotoxicity may be corrected by NK-cell stimulatory cytokines. PBMC were pre-incubated overnight with IL-2 and interferon-alpha. Both cytokines stimulated NK/K562 activity in all tested groups. Significant stimulation of NK/SKv activity was observed in PBMC from normal and weakly responding controls as well as patients with no lesions. No increase could be seen in patients with active disease. Evaluations of NK-cell activity before and after surgical removal or spontaneous regression of the lesions showed normalization of primarily depressed NK/SKv activity. Malignant progression was associated with a significant drop in SKv cell killing. Our results suggest that abrogation of NK-cell activity against HPV16-harboring targets in patients with HPV16-associated anogenital neoplasia is associated with restricted inability to recognize the disease-specific target cells, and may depend on persistence of the lesions.

Anus Neoplasms↗
PubMed1993

Alterations of T-cell: extracellular matrix proteins interactions in psoriasis.

Recent data indicate that extracellular matrix proteins (collagens, fibronectin) co-stimulate T-cell lymphoproliferative responses in vitro. We have studied the co-stimulatory activities of those proteins in patients with psoriasis, a disease in which T cells infiltrating the skin are continuously exposed to collagen and fibronectin. CD3-triggered T-cell proliferative responses were lower in psoriasis but could be enhanced by collagens I and IV and fibronectin. Interestingly, collagen-I-dependent co-stimulation was markedly decreased in patients with psoriasis, while there was a trend towards the enhancement of collagen-IV-induced responses. Those disturbances were most frequently seen in patients with active and widespread lesions. It appears that abnormalities of extracellular matrix protein-derived signals could play a role in the immunopathology of psoriasis.

Adult↗
PubMed1993

Expression of type VI collagen mRNA during wound healing.

During the highly regulated process of wound healing the expression of the interstitial collagens I and III is increased in a time-dependent fashion. Although ultrastructural and in vitro studies suggest a physiologic role of collagen VI in the organization of extracellular matrix deposition, nothing is known about its role in wound healing. Therefore, we studied collagen VI gene expression during wound healing in humans compared to that of collagens I and III. The presence of specific alpha 1(VI) and alpha 3(VI) mRNA species in scar tissue was demonstrated by Northern blot analysis. Quantification of mRNA expression by dot blot analysis and in situ hybridization indicated that like for the interstitial collagens I and III collagen VI gene expression was increased during wound healing, reaching its maximum 2 weeks after initial insult. In the late phase of wound healing like alpha 1(I) the alpha 1(VI) gene expression was not down regulated significantly. In contrast, a reduction of alpha 3(VI) collagen gene expression was observed, as was for the alpha 1(III) collagen gene, indicating a non-coordinate regulation of these chains. Collagen VI gene expression could be localized to fibroblast-like cells and to endothelial cells of newly formed vessels. Collagen VI gene expression was undetectable in smooth muscle cells and myoepithelial cells of eccrine glands. These results indicate that collagen VI gene expression is regulated in a time-dependent fashion and that fibroblasts and endothelial cells appear to play an important role in collagen VI synthesis during wound healing.

Collagen↗
PubMed1992

Autocrine growth limitation of human papillomavirus type 16-harboring keratinocytes by constitutively released tumor necrosis factor-alpha.

TNF-alpha is known to exert antitumor and antiviral effects and to participate in the regulation of the immune response. In our study we demonstrate that human rTNF-alpha specifically blocks growth of SK-v keratinocyte cell line harboring and expressing human papillomavirus type 16 (HPV16) sequences. This inhibitory effect was shown by [3H]TdR incorporation and cell counting. Binding experiments with 125I-TNF-alpha showed that SK-v cells express about 10,000 single class TNF-alpha R per cell with affinity constant of about 0.7 nM. Binding of 125I-TNF-alpha could be inhibited by htr-9 mAb recognizing a 55/60-kDa type I TNF-alpha R but not by utr-1 mAb recognizing 75/80-kDa type II TNF-alpha R or irrelevant mAb specific for HPV16E7 protein. Addition of anti-TNF-alpha antibodies to SK-v cell culture resulted in significant (p < 0.05), dose-dependent stimulation of their proliferation. SK-v cells constitutively expressed TNF-alpha mRNA, and SK-v CM contained TNF-alpha, as demonstrated by Northern blot analysis, a specific ELISA, Western blot analysis, and a bioassay with TNF-alpha-sensitive L-M cells. HPLC gel filtration of SK-v cell CM showed that the factor cytotoxic for L-M cells coeluted with immunoreactive TNF-alpha. These results demonstrate that HPV16-harboring SK-v cells constitutively express and release immunoreactive and biologically active TNF-alpha that in turn may exert an autocrine growth inhibitory effect. This phenomenon could represent one of the self-limiting mechanisms controling growth of HPV-induced neoplasia.

Cell Division↗
PubMed1992

Adhesion of peripheral blood mononuclear cells to vascular endothelium in patients with systemic sclerosis (scleroderma).

OBJECTIVE: Perivascular infiltrates in skin, subcutaneous tissue, and internal organs are a characteristic feature of early systemic sclerosis (SSc). We studied the first step of migration of peripheral blood mononuclear cells (PBMC) through the vessel wall to the extravascular space, i.e., adhesion of PBMC to endothelial cells (EC), in patients with various forms of SSc (limited scleroderma, diffuse scleroderma, and the transitional form). METHODS: Radioisotope-labeled patient PBMC were coincubated with umbilical cord EC in vitro, and the percentage adhesion was measured. RESULTS: Adhesion of PBMC to EC was markedly decreased, while adhesion of isolated active rosette-forming cells (ARFC) was significantly increased, in SSc patients compared with healthy controls. Decreased adhesion of PBMC to EC was found to correlate with a diminished percentage of ARFC in the peripheral blood. Preincubation of PBMC from healthy donors with interleukin-2 (IL-2) enhanced their adhesion to EC, while preincubation of PBMC from SSc patients with this cytokine resulted in a decrease in adhesion in 10 of 14 individuals. IL-1, interferon-gamma, and transforming growth factor beta had no significant effect on adhesion of SSc patient PBMC to EC. Differences in adhesion of PBMC to EC among the SSc subgroups were not significant. CONCLUSION: Our findings suggest that in SSc, activation of subpopulations of PBMC leads to their enhanced adhesion to vascular endothelium in vivo and to migration of these cells to the extravascular space, resulting in the elimination from the peripheral blood of those PBMC with high ability to adhere to EC.

Adult↗
PubMed1992

Epidermodysplasia verruciformis as a model of human papillomavirus-induced genetic cancers: the role of local immunosurveillance.

Epidermodysplasia verruciformis (EV) presents a genetically determined, unusual susceptibility to infection with EV-specific human papillomaviruses (HPVs) related to abrogation of immunosurveillance exclusively against these viruses. The cutaneous viral carcinogenesis depends upon potentially oncogenic HPVs, the cocarcinogenic effect of ultraviolet irradiation, and genetic host factors, presumably a defect of anti-oncogenes or alleles of major histocompatibility complex and tumor necrosis factor locus involved in antigen presentation.

Epidermodysplasia Verruciformis↗
PubMed1992

Increased adhesion of fibroblasts from patients with scleroderma to extracellular matrix components: in vitro modulation by IFN-gamma but not by TGF-beta.

A characteristic feature of systemic scleroderma is fibrosis of the skin and eventually of internal organs resulting from an overproduction of collagen and other connective tissue components by the resident fibroblasts. The balance between the cells and the amount of the surrounding extracellular matrix is then altered. Because cellular metabolism depends to a large extent on cellular contacts and communications with connective tissue molecules, we have therefore investigated the interactions with extracellular matrix components of fibroblasts obtained from skin of patients affected with scleroderma. In comparison to fibroblasts from healthy skin, all fibroblasts from scleroderma patients had an increased adhesion capacity to collagens I, IV, VI, fibronectin, and laminin. In addition, whereas adhesion of control fibroblasts was stimulated by a pre-treatment with transforming growth factor-beta, adhesion patterns of scleroderma fibroblasts remained unchanged. However, pre-incubation of the cells with interferon-gamma decreased the adhesion of both scleroderma and control fibroblasts.

Cell Adhesion↗
PubMed1992

The effect of interferon-gamma on the invasiveness of HT-180 cells.

It has been shown that tumour necrosis factor-alpha (TNF-alpha) induces the gene expression of collagenase and enhances the invasiveness of many cell types. However, we have previously demonstrated that interferon-gamma (IFN-gamma) induces the chemotactic response of cells and we have studied the in vitro effects of both cytokines on invasive migration using a human fibrosarcoma cell line (HT-1080). Invasive migration occurred with HT-1800 cells through a basement membrane equivalent (matrigel) and collagen type I gel. Pre-incubation of cells with increasing concentrations of IFN-gamma resulted in a dose-dependent reduction of this invasive migration. TNF-alpha considerably enhanced the invasiveness of HT-1080 cells and of fibroblasts. This effect could be significantly diminished by the pre-incubation of cells with IFN-gamma. Inhibition of invasiveness did not appear to be due to an altered binding to the barriers or altered collagenolytic activity of these cells, as shown by attachment and collagenase assays. These data support the concept that IFN-gamma can reduce the invasiveness of transformed cells which contributes to its in vivo anti-neoplastic effect.

Cell Adhesion↗
PubMed1992

Excessive collagen formation in fibrolamellar carcinoma of the liver: a morphological and biochemical study.

We have studied the excessive deposition of extracellular matrix in a patient with fibrolamellar carcinoma of the liver. The collagen matrix was predominantly composed of collagens I, III, and V. Since specific mRNAs for collagens I and III were detected by in situ hybridization, we also provide evidence that the fibroblastoid stromal cells were the major source of this collagen. Occasionally, also tumor cells could be shown to express collagen III-mRNA. Furthermore, some tumor cells showed positive signals for TGF-beta 1, while isolated stromal cells expressed interleukin-6. This cytokine expression may probably be related to the altered control of collagen gene expression.

Adolescent↗
PubMed1991

Dose fractionation and tumour repopulation in radiotherapy for bladder cancer.

Local control of the 77 transitional cell carcinoma of the bladder was analysed with respect to total dose after normalization for variations in fraction size and to overall treatment time. For the TCD50 of 63.3 Gy protraction of overall treatment time from 40 to 55 days average gave the decrease in local control rate from 50% to about 5%. The decrease in local tumour control with extension of overall treatment time likely reflects accelerated tumour repopulation during the treatment. To determine the time onset of the accelerated tumour clonogen repopulation, data taken from the literature were analysed. Results show that on average tumour clonogen repopulation in transitional cell cancer of the bladder accelerates after a lag period of about 5-6 weeks after the start of treatment and that a dose increment of 0.36 Gy per day is required to compensate for this repopulation. Such a dose increment is consistent with about 5-8 day clonogen doubling time. It suggests that overall treatment time is an important factor in the dose fractionation and protraction of time may have a significant impact on treatment outcome. Thus, radiotherapy for bladder cancer should be completed as soon as possible and total dose for high probability of local tumour control should consequently be delivered in more than 5 fractions per week.

Chemical Fractionation↗
PubMed1991

Expression of intercellular adhesion molecule-1 (ICAM-1) in the skin of patients with systemic scleroderma.

The expression and tissue distribution of intercellular adhesion molecule-1 (ICAM-1) in skin biopsies from 12 patients with systemic (SSc) and localized (LS) scleroderma was studied and compared to the biopsies from patients with lupus erythematosus (LE) and normal individuals. In normal human skin ICAM-1 expression was restricted to the vascular endothelium, infiltrating mononuclear cells (MNC), and to few individual keratinocytes. In the inflammatory stage of SSc, however, the expression of ICAM-1 was dramatically increased at the site of MNC infiltrates and could also be detected on fibroblast-like cells lying well apart from these infiltrates in the deep dermis. In contrast, in LS ICAM-1 was expressed mainly at the sites of MNC infiltrates. In LE ICAM-1 expression was confined to the keratinocytes, endothelial cells, and mononuclear cells in the upper parts of the dermis. Analysis of serial tissue sections from patients with SSc demonstrated also colocalization of staining of ICAM-1 around blood vessels with LFA-1-positive lymphocytes. Increased expression of ICAM-1 in the dermis of patients with SSc may represent an important mechanism by which MNC become localized and retained at a site of connective tissue inflammation, leading to the activation of fibroblasts.

Adult↗
PubMed1991

TGF beta-1 and TNF alpha expression in the epidermis of patients with epidermodysplasia verruciformis.

In epidermodysplasia verruciformis (EV), the infection with specific human papillomaviruses (HPV) might be under control of the local immunosurveillance mechanisms related to cytokines produced by epidermal cells. We have investigated by in situ hybridization the expression of mRNA coding for TGF beta-1 and TNF alpha in the skin of patients with EV (n = 4) as compared to the skin lesions of patients with other premalignant (actinic keratosis; n = 5) or malignant (squamous cell carcinoma; n = 4) skin lesions, and to the skin of healthy individuals (n = 5). The expression of TGF beta-1 and TNF alpha mRNA was higher in the epidermis of EV patients as compared to the control skin from healthy individuals. The increased expression of mRNA for both cytokines was confirmed by northern blot analysis of RNA isolated from the skin lesions of the patient with EV. No specific signals for TGF beta-1 and TNF alpha were detected in actinic keratosis, and in cases of squamous cell carcinomas only single neoplastic cells were positive for TGF beta-1. It is conceivable that in EV TGF beta-1 and TNF alpha can be involved in the regulation of the growth and differentiation of HPV-infected keratinocytes and in the persistence of HPV-induced skin lesions.

Adult↗
PubMed1991

Acitretin decreases tumor cell-induced angiogenesis.

The effects of acitretin and etretinate on angiogenesis induced in Balb/c mice by intradermal injection of keratinocyte tumor cell lines were evaluated. It was shown that both retinoids are capable of inhibiting angiogenesis evoked by a human epidermoid carcinoma cell line (A431). Acitretin, but not etretinate, inhibited also angiogenesis induced by the spontaneously transformed murine keratinocyte cell line Pam 212 and by the established tumorigenic SKv cell line harboring the HPV16 genome. We suggest that inhibition of blood vessel formation may be one of the mechanisms responsible for the anticancerogenic effect of retinoids.

Acitretin↗
PubMed1991

Beta-carotene in prevention of cutaneous carcinogenesis.

Beta-carotene, administered orally to mice, caused a decrease in angiogenesis evoked by HPV-transformed tumorigenic cell lines (SKv-t, HeLa). It did not affect angiogenesis induced by the non-tumorigenic SKv (not-t) cell line, and increased lymphocyte-induced immune angiogenesis. We suggest that the anti-cancerogenic effect of beta-carotene may be due, at least in part, to its inhibitory effect on formation of new blood vessels within the tumour mass.

Animals↗
PubMed1991

[Histopathologic evaluation of the reactivity of soft tissue to dental acrylate implants--in vivo examinations].

Wistar rats were implanted subcutaneously with samples of the home-made metacrylate material Akpol S and, for comparative purposes, with samples of the imported materials Trevalon and Superacryl. Throughout a period of 7 weeks, at 7-day intervals, sections of the tissues surrounding implants were collected from the animals and examined histopathologically. No differences in the character of the inflammatory reaction ensuing around the implants made from the three tested materials were observed. The dynamics of increase in the thickness of a pseudocapsule which developed at the edge of the inflammatory infiltration around the implants made from Akpol S and Trevalon was similar, whereas analogous values for the material Superacryl were higher. The conducted comparative in vivo studies permit us to evaluate positively the home-made metacrylate material Akpol S.

Animals↗
PubMed1991

[Reaction of dental methacrylate material in in vivo tests--selected hematologic and immunologic indices].

Wistar rats were implanted subcutaneously with 2.5 x 6 mm cylindrical matrices, made from the home-made metacrylate material Akpol S, and, for comparative purposes, with the imported materials Trevalon and Superacryl. At different time intervals quantitative and qualitative analyses of the picture of leucocytes and of blood plasma proteins were carried out in groups of animals implanted with the above-mentioned materials and in a control one. No differences in the values of the above parameters were found in any of the examined groups of animals. The carried out tests were aimed at making a thorough study of general reaction of the living organism to the new, home-made metacrylate material Akpol S, used for making removable dentures.

Animals↗
PubMed1990

Cytotoxic effects of sera from patients with systemic scleroderma: comparison of three different in vitro methods.

Sera from 93 patients with systemic scleroderma including incipient or prodromal acroscleroderma and from 43 healthy individuals were studied for cytotoxic effects on endothelial cells by means of three different in vitro methods. Inhibition of 3H-thymidine incorporation by endothelium was caused by about 33% of sera, almost exclusively from patients with diffuse scleroderma and the transitional form: acroscleroderma--diffuse scleroderma. An antibody-dependent cellular cytotoxicity assay revealed cytotoxicity of about 37% of sera from patients with diffuse scleroderma and the transitional form but also of a proportion of sera from patients with CREST syndrome with pronounced vascular changes. Serum cytotoxic activity, revealed by both methods, was related with more frequent involvement of muscle and kidney in the patients. A direct 51Cr release assay showed the cytotoxicity only in 4 of 68 cases in diffuse scleroderma with pronounced internal organ involvement. Thus, depending on the method used, various types of cytotoxicity could be detected in sera from patients with systemic scleroderma.

Adult↗