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D J Ruiter

Publications and source records attributed to D J Ruiter.

At least 145 records · Page 8Linked to original sources
PubMed1993

Thymosin beta-10 expression in melanoma cell lines and melanocytic lesions: a new progression marker for human cutaneous melanoma.

When screening a subtraction library for sequences that were specifically expressed in highly metastatic human melanoma cell lines, a cDNA clone was isolated encoding thymosin beta-10. We found that expression of thymosin beta-10 mRNA was associated with metastatic behavior of various human melanoma cell lines in nude mice. Furthermore, Northern blot analysis showed that also in freshly harvested human melanocytic lesions thymosin beta-10 was differentially expressed. Although expression of thymosin beta-10 was also examined in other non-melanoma model systems and materials, no clear relation could be established with metastatic potential or malignancy. Therefore, we conclude that thymosin beta-10 can be considered as a new progression marker for human cutaneous melanoma.

Amino Acid Sequence↗
PubMed1993

Cellular components of microvascular proliferation in human glial and metastatic brain neoplasms. A light microscopic and immunohistochemical study of formalin-fixed, routinely processed material.

Since the origin of cells contributing to microvascular proliferation (MVP) in glial neoplasms is unsettled, a light microscopic and immunohistochemical study for vascular smooth muscle cells and endothelial cells was performed in formalin-fixed, routinely processed brain tumor biopsy material. MVP in glial neoplasms was compared with that in intracerebral metastatic carcinomas and in intracranial granulation tissue. On the basis of the degree of hyperplasia of hypertrophic cells in the microvascular wall, MVP was subjectively divided into mild, moderate, and glomeruloid (marked) proliferation. The relative contribution of vascular smooth muscle cells and endothelial cells to different degrees of MVP was estimated immunohistochemically using antibodies against alpha-smooth muscle actin and von Willebrand factor, respectively. Glomeruloid MVP occurred in 50% of the malignant glial neoplasms. Moderate MVP was found in most malignant gliomas and in some pilocytic astrocytomas. Glomeruloid MVP was present in peritumoral glial tissue in 4 out of 15 intracerebral metastatic carcinomas, while only mild to moderate MVP was found within these tumors. In granulation tissue MVP was mild. In glomeruloid and moderate MVP vascular smooth muscle cells were more hypertrophic and more numerous than endothelial cells. The contribution of hypertrophic vascular smooth muscle cells to mild MVP was variable. MVP in glial neoplasms was generally not accompanied by a matrix of fibrous stroma but was directly embedded in glial tissue. The architecture of this MVP suggested "in situ" proliferation of microvascular cells without migration of these cells into the surrounding tissue.

Actins↗
PubMed1993

Topical treatment of ichthyoses and Darier's disease with 13-cis-retinoic acid. A clinical and immunohistochemical study.

In a bilaterally paired double-blind comparison study, a cream containing 0.1% 13-cis-retinoic acid (13-cis-RA) and cream base only were applied over 4 weeks in seven patients with non-erythrodermic lamellar ichthyosis (NELI), two patients with Darier's disease and one patient with autosomal dominant ichthyosis vulgaris (ADIV). In two patients with NELI and two patients with Darier's disease a half-side effect was observed in favour of the side treated with 13-cis-RA. In three patients an induction of cytokeratin-4, and in one of these patients expression of cytokeratin-13, were observed after therapy. Topical 13-cis-RA appears to be a promising approach in the treatment of disorders of keratinization. The selective modulation of the cytokeratin pattern may provide an immunohistochemical tool to investigate the mode of action of retinoids.

Administration, Cutaneous↗
PubMed1993

The proliferative response of human T cells to allogeneic IFN-gamma-treated endothelial cells is mediated via both CD2/LFA-3 and LFA-1/ICAM-1 and -2 adhesion pathways.

We studied the proliferative response of purified human peripheral blood T lymphocytes (contaminated with less than 0.1% monocytes) to allogeneic MHC class II molecules expressed by endothelial cells (EC) or fibroblasts (FB). In vitro expression of MHC class II molecules was induced by gamma-interferon (IFN-gamma) treatment. The MHC class II expression levels after IFN-gamma treatment on both cell types were comparable. No T cell proliferation was found in the presence of either untreated or IFN-gamma-treated FB, and a marginal proliferation in the presence of untreated EC. IFN-gamma-treated EC, however, were able to induce significant T cell growth. The previously established role of MHC class II molecules in allogeneic T cell proliferation was confirmed in inhibition experiments with monoclonal antibody (mAb) against MHC class II or CD4. In this model, we tested the involvement of a number of adhesion molecules by adding mAbs to cocultures of T cells and IFN-gamma-treated EC. Monoclonal antibodies directed against CD31, CD26, B7/BB1, E-selectin, CD44, VLA-4 alpha-chain and VCAM-1 had no effect, whereas moderate inhibition was observed with anti-VLA-beta-chain and anti-LFA-3. A distinct inhibition of T cell proliferation was observed with mAbs directed against LFA-1, CD2, or a combination of anti-ICAM-1 and -2. Combinations of mAbs directed against T cell adhesion molecules (LFA-1, CD2, VLA-4) or EC adhesion molecules (ICAM-1, and -2, LFA-3, VCAM-1) were able to block T cell proliferation for 100 and 80% respectively. We conclude that CD2/LFA-3 and LFA-1/ICAM interactions are crucially involved in allogeneic T cell/EC interactions.

Antibodies, Monoclonal↗
PubMed1993

Validity of the histopathological criteria used for diagnosing dysplastic naevi. An interobserver study by the pathology subgroup of the EORTC Malignant Melanoma Cooperative Group.

Ten (dermato)pathologists studied 50 cutaneous melanocytic lesions including common naevocellular naevi, dysplastic naevi (DN), melanomas in situ and invasive primary melanomas, with emphasis on the histological criteria of DN. Using a standardised form, 20 defined histopathological features were scored (semi)quantitatively. Concordance of diagnosis, efficacy and reproducibility of features were investigated. DN were distinguished well from the other entities (mean Po 0.87). Agreement on the degree of atypia of DN was low. The reproducibility of the scoring was best for the following features: irregular nests, lymphohistiocytic infiltrate, marked junctional proliferation and large nuclei. The overall values of these features to discriminate between DN and non-DN were better than for the other features studied. Using the presence of at least three of the four features as a condition for the diagnosis of DN, values for sensitivity, specificity and positive and negative predictive values were 0.86, 0.91, 0.96 and 0.73, respectively. On the basis of the results these features seem best suited as histological criteria for the diagnosis of DN.

Diagnosis, Differential↗
PubMed1993

The possible role of angiogenesis in the metastatic potential of human melanoma. Clinicopathological aspects.

In this review, we present a literature survey of angiogenesis in melanoma. Progression in melanoma is supposed to be associated with an angiogenic response. Several histological studies have shown an increase of vascular structures in malignant melanoma, which is not the case in common naevocellular naevi. Neovascularization can be caused by several angiogenic factors: the most important of those produced in melanoma are described. Proteases such as urokinase plasminogen activator and metalloproteinases are important for the migration for both endothelial cells and tumour cells. Possible effects of these factors in melanoma cells are discussed. Finally, inhibition of angiogenesis and its potential role in melanoma therapy are considered.

Animals↗
PubMed1993

Effects of systemic interferon-alpha (IFN-alpha) on the antigenic phenotype of melanoma metastases. EORTC melanoma group cooperative study No. 18852.

In order to investigate the effects of in vivo treatment with interferon-alpha (IFN-alpha) on melanoma antigens, a clinical EORTC trial (No. 18852) was accompanied by an immunohistological study. Twenty patients with melanoma metastases of skin and soft tissues, eventually also of the lung, who were treated with systemic IFN-alpha, were evaluated for a comparison of metastases before (40) and during (42) treatment. Representative cryostat sections were studied immunohistologically with a panel of monoclonal antibodies against differentiation antigens (HMW-MAA, K-1-2, NKI-beteb, M-2-10-15), progression markers (transferrin receptor, ICAM-1, VLA-2), histocompatibility antigens (HLA-A, B, C, HLA-DR) and the proliferation-associated nuclear antigen Ki67. We found an overall reduction of the proliferation-associated antigen Ki-67 (p < 0.01), and an increase in expression of HLA-DR (p < 0.05) and ICAM-1 (trend) during treatment. The intensity of expression of HLA-A, B and C antigens as well as pigmentation (p < 0.01) was found to be increased. Early progression (< or = 8 weeks after onset of treatment) was associated with a lack of phenotypic changes. The data suggest an independent modulation of proliferation, pigmentation, and antigen expression by systemic treatment of metastatic melanoma with IFN-alpha.

Adult↗
PubMed1993

A new 180-kDa dermal endothelial cell activation antigen: in vitro and in situ characteristics.

PN-E2 is a monoclonal antibody generated against recombinant tumor necrosis factor-alpha (TNF-alpha)-treated human umbilical vein endothelial cells (EC). PN-E2 recognized a molecule with expression levels in vitro that could be downregulated by TNF, and in situ PN-E2 showed only weak reactivity with vascular EC in normal skin, as assessed by immunohistochemical staining. The expression of PN-E2 was considerably increased on EC in various pathologic skin lesions, including psoriasis, granulation tissue, and inflamed skin. PN-E2 antigen expression was analyzed in more detail in vitro on cultured EC and fibroblasts by use of enzyme-linked immunosorbent assay and fluorescence-activated cell sorter techniques. The expression level on human umbilical vein endothelial cells and capillary EC was, in contrast to the in situ immunohistologic findings, invariably high. On fibroblasts, a low expression was found. Incubation of the EC with recombinant TNF-alpha decreased expression by a factor of 2. Incubation of EC with recombinant interferon-gamma resulted in a twofold increase in PN-E2 antigen expression, whereas other cytokines [recombinant interleukin (rIL)-1 alpha, rIL-1 beta, rIL-4, rIL-6], lipopolysaccharide, or recombinant basic fibroblast growth factor had no effect. Immunoelectron microscopy of tissue specimens and EC preparations localized the antigen on the luminal membrane of the endothelium. Immunoprecipitation followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed a major band at 90 kDa and a minor band at 80 kDa under reducing conditions and bands of 180 and 400 kDa under non-reducing conditions. Molecular weight and expression patterns in vitro on EC after incubation with cytokines excluded most of the known endothelium-specific molecules, with the possible exception of endoglin (the 44G4 antigen). We conclude from our findings that this new antigen could be useful as a marker for endothelial activation in skin biopsy material.

Antibodies, Monoclonal↗
PubMed1993

Endothelial cells promote anti-CD3-induced T-cell proliferation via cell-cell contact mediated by LFA-1 and CD2.

T-cell activation requires not only T-cell receptor (TCR) engagement and subsequent TCR/CD3 cross-linking, but also one or more secondary activation signals generated by accessory cells (AC). We investigated the accessory function of endothelial cells (EC) in an in vitro model for T-cell activation where the first cross-linking signal was delivered to peripheral human T lymphocytes by either immobilized anti-CD3 monoclonal antibody (MoAb) or by PHA. In a previous report, we showed that EC provided a potent costimulatory signal in this model system. We have now analysed the nature of the EC-derived costimulatory signal by testing whether EC could be substituted by cytokines, by studying the effect of EC fixation and by testing the involvement of a number of adhesion molecules. Our findings indicate that EC accessory function is mediated mainly by membrane-bound factors. The nature of these membrane-bound factors was analysed by studying the inhibitory properties of a series of MoAbs directed against several adhesion molecules. Antibodies directed against CD44, E-selectin, CD31, CD26, B7/BB1, VLA-4 or VCAM-1 were not inhibitory. However, an inhibition, was clearly observed with antibodies against LFA-1 and CD2. Remarkably, this inhibition was not found with MoAbs to their respective counterstructures ICAM-1 and LFA-3. In summary, we postulate that both LFA-1/ICAM-1, and CD2/LFA-3 interactions are involved in EC accessory function, although the role of the EC-associated adhesion partners is not fully understood.

Antibodies, Monoclonal↗
PubMed1993

Melanoma and occupation: results of a case-control study in The Netherlands.

Several studies have reported excesses of risk of melanoma in specific industries. Data from a case-control study in The Netherlands, including 140 cases with a cutaneous melanoma and 181 controls with other types of malignancy, were used to evaluate whether the reported associations with these specific industries could be reproduced. Adjustment for characteristics of pigmentation and exposure to sunlight was made. Increased risks of cutaneous melanoma were found for subjects who had ever worked in the electronics industry (odds ratio (OR) = 2.03, 95% confidence interval (95% CI) 0.63-6.62), in the metal industry (OR = 2.61, 95% CI 0.96-7.10), and in the transport and communication branch (OR = 1.92, 95% CI 0.84-4.35). These ORs were adjusted for age, sex, education, hair colour, tendency to burn, freckling, and exposure to sunlight. No increased risks were seen for workers in the chemical industry, the textile industry, and among health care workers. Analyses according to duration and latency of exposure did not give consistent results, but existing patterns may be obscured by the imprecision of the estimates.

Age Factors↗
PubMed1993

Monoclonal antibody MS-44B reacts with human dendritic, glial and endothelial cells: differential expression of MS-44B antigen by epidermal dendritic cells and by MS-1+ splenic sinusoidal endothelial cells. An immunohistological study.

Rat monoclonal antibody MS-44B was raised against the dendritic human melanoma cell line SK-Mel 25 and detects highly dendritic cells and endothelial cells in various human organs. Among the cells recognized are dendritic cells in lymphoid organs, such as lymph node, tonsil and spleen, dendritic cells in skin, lung and lamina propria, (astro-)glial cells in the central nervous system and mesangial cells in the kidney. In peripheral lymph nodes (and less consistently in visceral lymph nodes), MS-44B reactive cells are found predominantly in the paracortical area and in the region of the marginal sinus; in tonsils these dendritic cells are concentrated at the outer rim of the follicle, while their distribution in the white pulp of the spleen is less well defined. In skin, both dermal and epidermal dendritic cells are stained. In the dermis just beneath the dermal-epidermal border, dendritic cells may be found with their processes protruding into the epidermal basal layer. MS-44B reactive epidermal dendritic cells send their processes in a horizontal direction or into the upper epidermal cell layers. MS-44B reactive epidermal dendritic cells are neither Langerhans cells, since they lack HLA-DR antigens and CD1, nor Merkel cells, since they lack cytokeratin expression. They rather seem to constitute a subpopulation of epidermal melanocytes that are low in tyrosinase expression and do not populate the melanocyte area of the hair bulb. With regard to the endothelium, monoclonal antibody MS-44B reveals marked heterogeneity in that it preferentially stains the endothelium of large and medium-sized arterial vessels, while capillary and venous endothelia are less well stained.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Effect of intermittent exposure to sunlight on melanoma risk among indoor workers and sun-sensitive individuals.

Intermittent exposure to sunlight is considered to be an important risk factor for melanoma, but the associations reported in most case-control studies are surprisingly weak. The aim of this study was to evaluate whether the incorporation of a subject's background exposure to the sun and pigmentation characteristics (which are assumed to influence a person's susceptibility to sunlight exposure) could produce stronger associations between sunlight exposure and the risk for melanoma. A population-based case-control study was performed in the mid-eastern part of the Netherlands. The study group comprised 141 patients with a histologically verified melanoma and 183 controls with other malignancies who were registered by the same cancer registry. Patients with a lentigo maligna melanoma or an acrolentiginous melanoma were excluded. Information was collected by interviews and physical examination. We categorized subjects as indoor or outdoor workers on the basis of occupational exposure to the sun. Pigmentation characteristics, which are known to be risk indicators for cutaneous melanoma, were summarized as one sun sensitivity score. We used this score to distinguish between sun-sensitive and sun-resistant persons. The odds ratios associated with sunbathing, vacations spent in sunny countries, and sunburns were higher among the indoor workers than among the outdoor workers. After stratification by the sun sensitivity score, the effect of sunbathing, participating in water sports (swimming excluded), vacations to sunny countries, and a history of sunburn was largest for the sun-sensitive persons. The data show a general trend toward higher relative risks among indoor workers and sun-sensitive individuals. The results of this study support the intermittent sunlight hypothesis.

Adolescent↗
PubMed1993

Angiogenesis in wound healing and tumor metastasis.

Formation of new blood vessels is essential for several physiological and pathological events, e.g. embryogenesis, wound healing and tumor growth and metastasis. In order to increase the insight into the mechanisms of angiogenesis we have visualized the different components of the microvasculature in human wounds and tumors by immunohistochemistry on the light and electronmicroscopic level. For this purpose, antibodies recognizing distinct markers for human endothelial cells, pericytes and basal lamina were used on freshly frozen or paraformaldehyde-fixed tissue samples. In terms of efficacy, the PAL-E antigen is highly specific for blood vessel endothelium. Its sensitivity is less than other endothelial markers, such as von Willebrand factor and CD 31, as it is not expressed in arterioles. Within the context of the microvasculature alpha-smooth muscle actin and the HMW-MAA chondroitin sulphate proteoglycan are useful markers for pericytes. Type IV Collagen and Laminin can be visualized consistently in the microvascular basal lamina. During the formation of granulation tissue in wound healing a heterogeneity of the expression of endothelial and pericyte markers is found. In the least matured zone in granulation tissue of decubitus lesions and experimental skin wounds microvessels already contained both endothelial cells and pericytes, suggesting a role for both cell types in the early steps of angiogenesis. Regarding the tumor microvasculature, antibodies to von Willebrand factor often failed to stain capillaries, that did show expression of the other endothelial markers studied. Broad staining in pericytes was found for the HMW-MAA chondroitin sulphate proteoglycan. In contrast, these cells only locally expressed alpha-smooth muscle actin. Staining of the basal lamina components Type IV Collagen and Laminin within tumors was not restricted to the microvasculature. Therefore, antibodies recognizing endothelial markers, particularly PAL-E and BMA 120, are preferable as tools to visualize the tumor microvasculature. In accordance with the situation in granulation tissue of wound healing the broad presence of pericytes in the microvasculature of human tumor suggests an involvement of this cell type in tumor angiogenesis. Recent immunohistochemical studies on human tumor lesions indicated that a high number of microvessels adjacent to the tumor as a measure of tumor angiogenesis is an unfavorable prognostic factor in cutaneous melanoma, mammary carcinoma and non-small cell pulmonary carcinoma. This new application of immunohistochemistry represents a valuable, clinically relevant adjunct to the repertoire of the surgical pathologist.

Animals↗
PubMed1993

Involvement of LFA-1/ICAM and CD2/LFA-3 in human endothelial cell accessory function.

Interactions of endothelial cells with T cells occur during the process of lymphocyte migration and during leukocyte extravasation in the course of an inflammatory response. Adhesion molecules are crucially involved in these interactions. It has been assumed that, in this way, endothelial cells play an important role in the recruitment of immune cells to sites of inflammation. In vitro experiments indicate that, in addition to this function in leukocyte recirculation, endothelial cells might also be involved as accessory cells in the stimulation of T cells. In this overview, the possible role of adhesion molecules in this process will be discussed.

Antigens, CD↗
PubMed1993

Melanocyte lineage-specific antigens recognized by monoclonal antibodies NKI-beteb, HMB-50, and HMB-45 are encoded by a single cDNA.

The glycoproteins recognized by monoclonal antibody (MAb) NKI-beteb are among the best diagnostic markers for human melanoma. MAb NKI-beteb reacts with melanoma cells throughout tumor development and does not cross-react with other tumor or normal cells, except for cells of the melanocytic lineage. Two other melanocyte lineage-specific MAbs, HMB-50 and HMB-45, show a specificity and staining pattern strikingly similar to the ones observed for NKI-beteb. Herein, we demonstrate that all three MAbs recognize protein products encoded by a single cDNA. Expression of this cDNA in BLM cells results in immunoreactivity with all three MAbs. In addition, we demonstrate co-distribution of the RNA species detected by the cDNA with the proteins recognized by the MAbs in tissue sections.

Antibodies, Monoclonal↗
PubMed1993

Integrin expression in uveal melanoma differs from cutaneous melanoma.

PURPOSE: During the process of metastasis, changes in cell-cell and cell-matrix contacts occur; therefore, expression of integrins, a superfamily of adhesion molecules, may be important. Expression of integrins has been studied extensively in cutaneous melanoma. Because it is known that uveal melanoma has a metastatic behavior different from cutaneous melanoma, the authors investigated integrin expression in uveal melanoma. METHODS: The authors used monoclonal antibodies recognizing integrin subunits alpha 1-6, alpha v, beta 1, and beta 4 and integrins alpha v beta 3 and alpha v beta 5 on frozen sections of 32 human primary uveal melanomas and 4 metastases, followed by an avidin-biotin-peroxidase complex-immunoperoxidase technique. RESULTS: As in cutaneous melanoma, alpha 4 expression was rare, but most lesions expressed alpha 3 and alpha 6. In contrast to cutaneous melanoma, in which alpha 2 is well expressed in most lesions and alpha 5 is expressed only in a small percentage of lesions, alpha 2 expression was rare in uveal melanoma and alpha 5 expression was found in all lesions. A major difference was observed with regard to the alpha v beta 3 vitronectin receptor. In contrast to cutaneous melanoma, in which alpha v beta 3 is expressed in advanced primary melanomas and metastases, alpha v beta 3 was not detected in any of the primary uveal melanomas, but all lesions strongly expressed alpha v beta 5. CONCLUSIONS: Integrin expression in uveal melanoma cannot be correlated with cell type or invasiveness. In contrast to cutaneous melanoma, it seems that determination of the integrin expression profile is not suitable for categorizing uveal melanomas as less malignant and highly malignant lesions.

Biomarkers, Tumor↗