PubMed Health⌕ Search

Biomedical subjects

B J Vermeer

Publications and source records attributed to B J Vermeer.

At least 19 recordsLinked to original sources
PubMed1995

Distribution of HLA class II molecules in epidermal Langerhans cells in situ.

We performed immunoelectron microscopic studies to investigate the expression of HLA class II molecules in Langerhans cells (LC). In the epidermis, LC expressed class II molecules on the plasma membrane of the dendrites, resulting in a class II positive reticulo-epithelial network, but not on the surface of the cell body. In contrast, isolated LC as well as activated LC in situ displayed an even and strong expression of class II molecules on their entire cell surface. Therefore, isolation and/or activation results in redistribution and up-regulation of class II molecules on the cell surface. In addition, double-labeling experiments were carried out with monoclonal antibodies to class II antigens and to LAMP-1, CD63 and alpha-glucosidase, specific markers for organelles of the endosomal/lysosomal system. The results show expression of class II molecules on intracellular, electron-dense vesicular structures, and co-localization of class II molecules and the markers for late endosomes and early lysosomes in human LC in situ. Expression of these markers was not found on Birbeck granules, an LC-specific organelle.

Animals↗
PubMed1995

A comparative study of atypical and melanocytic naevi on the tropical island Curaçao and in The Netherlands.

A cross-sectional study was undertaken in 270 inhabitants of The Netherlands (moderate maritime climate, latitude 51 degrees 5' N-53 degrees 3' N) with skin types I-III and 757 inhabitants of the tropical island Curaçao (latitude 12 degrees 2' N-12 degrees 23' N). The latter group consisted of 282 White individuals (mostly Dutch immigrants) and 475 people with non-White skin types IV, V and VI. All participants underwent total skin examination and melanocytic naevi (MN) and clinically atypical naevi (AN) were noted. There was no statistical difference in the mean number of naevi > or = 2 mm or > or = 5 mm between the Curaçao and The Netherlands White groups, but the mean number of naevi > or = 2 mm and > or = 5 mm was significantly lower in the Curaçao non-White group. We found no obvious differences in mean naevus counts between genders and the various comparable age groups. Furthermore, we found no significant difference in mean crude and mean age-standardized prevalence of (one or more) AN between Whites in The Netherlands and on Curaçao. The Mantel-Haenszel prevalence ratio weighted for age and gender differences of Curaçao Whites vs non-Whites was 5.93 (95% confidence interval 3.9-12.0), demonstrating that AN are significantly less prevalent in darker skin types. In all groups, people with AN had significantly more MN than people without AN. We found a generation-dependent difference in the expression of AN among White inhabitants of The Netherlands and on Curaçao, with a higher prevalence of AN in the younger generation.

Adolescent↗
PubMed1995

Comparison of melanocytes and keratinocytes in ultraviolet-induced DNA damage per minimum erythema dose sunlight: applicability of ultraviolet action spectra for risk estimates.

Action spectra are being used in risk estimates for ultraviolet (UV) damage. The purpose of our investigation was to compare the susceptibility of cultured melanocytes and keratinocytes to UV-induced DNA damage per minimum erythema dose (MED) and to determine whether the predictions made with action spectra agree with the damage actually induced. Genetic damage was measured as the number of T4-endonuclease V-sensitive sites (ESS). Predictions made with the action spectrum for the induction of DNA damage in melanocytes after irradiation with sunlight and a solar simulator were 15.9 and 13.2 ESS per 10(8) daltons per MED, respectively; with the action spectrum for the induction of DNA damage in keratinocytes the predictions were 12.1 and 9.8 ESS per 10(8) daltons per MED, respectively. To determine the actual damage per MED, cultured cells were irradiated with sunlight or a solar simulator, and MED was determined with an erythema UV meter. The induction of DNA damage in melanocytes after sunlight and solar simulator irradiation was 8.01 and 6.7 ESS per 10(8) daltons per MED, respectively, and in keratinocytes 7.49 and 7.12 ESS per 10(8) daltons per MED, respectively. This was considered to be in agreement with the predicted data. The use of action spectra for risk estimates in melanocytes appears justified.

Animals↗
PubMed1995

High frequency of detection of epidermodysplasia verruciformis-associated human papillomavirus DNA in biopsies from malignant and premalignant skin lesions from renal transplant recipients.

Based on immunologic and epidemiologic data, it is plausible that skin cancer in renal transplant recipients is associated with human papillomaviruses (HPV). At present, conflicting evidence exists concerning the presence of HPV DNA in these cancers. We recently described a nested polymerase chain reaction method that enables the detection of all previously isolated epidermodysplasia verruciformis (EV)-associated HPVs. We now describe the detection of EV-associated HPV DNA in 49 (80%) of 61 biopsies from squamous cell carcinomas, in four (50%) of eight basal cell carcinomas, in 14 (93%) of 15 actinic keratoses, in two (40%) of five cases of Bowen's disease, and in four (57%) of seven keratoacanthomas. HPV DNA typing revealed that all detected HPV types belonged to the EV-associated HPV types. A wide spectrum of EV-associated HPVs was found, including six putative new HPV types. In a high percentage of the lesions more than one HPV type was detected. We often found the same HPV types in different skin biopsies from both malignant and premalignant lesions from the same patient. The high frequency of detection of EV-associated HPV types in biopsies from malignant and premalignant lesions is in agreement with the hypothesis that EV-associated HPVs are involved in the pathogenesis of skin cancer in renal transplant recipients.

Adult↗
PubMed1995

Adjuvant high-dose intravenous gammaglobulin in the treatment of pemphigus and bullous pemphigoid: experience in six patients.

At present, initial high-dose prednisone is the treatment of choice for patients with pemphigus and bullous pemphigoid. To reduce the risks associated with long-term corticosteroid treatment, other immunosuppressants are often given as steroid-sparing agents. Occasionally, the dose of steroids cannot be reduced. In this study, we report six patients with pemphigus vulgaris, pemphigus foliaceus and bullous pemphigoid, in whom the daily corticosteroid dose could only be tapered to acceptable, effective, maintenance levels following treatment with high-dose intravenous gammaglobulin.

Adult↗
PubMed1995

Nested PCR approach for detection and typing of epidermodysplasia verruciformis-associated human papillomavirus types in cutaneous cancers from renal transplant recipients.

The epidermodysplasia verruciformis (EV)-associated human papillomaviruses (HPVs) constitute a group of HPV genotypes isolated mostly from the cutaneous lesions of patients with the genetic disorder of EV. Broad-spectrum detection of EV HPVs in cutaneous lesions of non-EV patients was previously difficult because no EV HPV consensus PCR was available. We describe a nested PCR that enables the detection of all known EV HPV types at relatively low-copy-number levels. The deduced sequences of a 92-amino-acid stretch of the L1 open reading frames of all types are shown for convenient typing. The technique proved very valuable in viral studies of skin cancers from renal transplant recipients. A high prevalence (81%) of EV HPV types was found in skin cancer biopsies. A wide spectrum of EV HPV types that differed from HPV-5 and -8 was found to be involved. The technique also proved useful in detecting potentially novel EV HPV types in skin cancers. The relationship of these new types to known HPV types is demonstrated by phylogenetic tree analysis.

Amino Acid Sequence↗
PubMed1995

Prevention of skin cancer and reduction of keratotic skin lesions during acitretin therapy in renal transplant recipients: a double-blind, placebo-controlled study.

PURPOSE: The purpose of this study was to investigate the effect of acitretin on the development of keratotic skin lesions, and on squamous cell carcinomas and basal cell carcinomas in a group of renal transplant recipients. PATIENTS AND METHODS: Forty-four renal transplant recipients with more than 10 keratotic skin lesions on the hands and forearms were enrolled onto a randomized, double-blind, placebo-controlled trial to test the possible skin cancer-preventing effect of a 6-month treatment with acitretin 30 mg/d. RESULTS: No deterioration in renal function occurred in any of the 38 assessable patients treated. During the 6-month treatment period, two of 19 patients (11%) in the acitretin group reported a total of two new squamous cell carcinomas, compared with nine of 19 patients (47%) in the placebo group who developed a total of 18 new carcinomas (chi 2 = 6.27, P = .01). The relative decrease in the number of keratotic skin lesions in the acitretin group was 13.4%, as compared with a relative increase in the placebo group of 28.2% (difference, 41.6%; 95% confidence interval, 11.5 to 71.7). Most patients treated with acitretin had mild mucocutaneous side effects, but these were easily manageable. Some patients experienced mild hair loss. With the exception of three patients, no increase in serum cholesterol or triglyceride above pretreatment levels was observed, and liver function remained unchanged in all patients. CONCLUSION: Acitretin 30 mg/d over 6 months had significantly more effect than placebo in the prevention of squamous cell carcinomas and reduced the occurrence of keratotic skin lesions in a group of renal transplant recipients with severe lesions. This effect was most pronounced in patients with a history of squamous cell carcinomas and basal cell carcinomas.

Acitretin↗
PubMed1994

Phorbol ester induced rapid attachment and spreading of melanoma cells and the role of extracellular matrix proteins.

Phorbol 12-myristate 13-acetate (PMA) is a tumour promotor that acts as a potent protein kinase C (PKC) activator that has significant effects on tumour cell attachment and spreading. We tested whether these effects of PMA may be observed in human melanoma cells, and whether a specific response to extracellular matrix proteins may be mediated by shifts in the expression of beta 1 integrins. We used cell attachment assays, video time lapse cell spreading assays, flow cytometry, function blocking monoclonal antibodies (MAbs) and PKC inhibitor Calphostin C to address these questions. We established that PMA induces a rapid and temporary enhancement of cell attachment and spreading which was not accompanied by a significant change in the expression of beta 1 integrins. Spreading of melanoma cells that were not stimulated with PMA could be significantly blocked with a function blocking MAb (clone P4C10) against the common beta 1 integrin subunit. The spreading and attachment of the PMA treated cells was also significantly reduced, but less so, after MAb treatment. The PMA enhanced cell attachment and spreading could be effectively blocked by RGD sequences and PKC inhibitor. Taken together, our data indicate that PMA induces a rapid and temporary ECM-dependent enhancement of melanoma cell attachment and spreading, and that the response to ECM components appears not to be due to significant shifts in beta 1 integrin expression, but rather to activation of beta 1 integrins.

Amino Acid Sequence↗
PubMed1994

The distribution of cellular adhesion molecules in pigmented skin lesions.

BACKGROUND: The process of multistep tumor development has been studied thoroughly in the development of malignant melanomas. The authors investigated the expression of cellular adhesion molecules in nevomelanocytic lesions to explore a postulated role of adhesion molecules in cell-cell and cell-matrix interactions during tumor development. METHODS: Sections of 20 nevocellular nevi, 35 dysplastic nevi, 6 melanomas in situ, and 20 malignant melanomas were investigated with respect to their expression of intercellular adhesion molecule-1 (ICAM-1), inducible cell adhesion molecule-110 (INCAM-110)/vascular cell adhesion molecule-1 (VCAM-1), E-selectin, lymphocyte function-associated antigen-1 (LFA-1), and the integrins for very late antigen-(VLA) alpha-(alpha) 2 and VLA-alpha 6; for these studies, monoclonal antibodies were used and indirect immunoperoxidase and immunofluorescence staining methods were performed. RESULTS: In the transformation from benign to malignant neoplasms, the expression of ICAM-1 was upregulated strongly. The expression of VLA-alpha 2 on tumor cells increased whereas that of VLA-alpha 6 decreased; these alterations corresponded to changes previously observed in their ligands within the extracellular matrix. These results were statistically significant. In addition, ICAM-1, INCAM-110/VCAM-1, and E-selectin were detected in activated endothelial cells, probably as a result of cytokine activation. The ligand for ICAM-1, LFA-1, was confined to mononuclear cells. CONCLUSIONS: The increase in ICAM-1 and VLA-alpha 2 expression and the decrease of VLA-alpha 6 expression may, in combination with specific matrix alterations, lead to a change in cell-cell and cell-matrix interaction, thereby contributing to the invasive property of melanocytic tumor cells. The neoexpression of INCAM-110/VCAM-1 and E-selectin in pigmented skin lesions may play a role in both infiltrative growth and the generation of a host reaction toward these tumors.

Animals↗
PubMed1994

Resurfacing the back of the hand as treatment and prevention of multiple skin cancers in kidney transplant recipients.

BACKGROUND: Skin cancer is a serious problem in renal transplant recipients. In some patients numerous skin cancers develop on the back of the hand. Instead of repeated excisions, a more radical procedure may be necessary. For these patients a new surgical therapy is available: resurfacing the back of the hand. OBJECTIVE: Our purpose was to clinically evaluate this new procedure. METHODS: Eleven kidney transplant recipients who underwent resurfacing of the back of the hand were analyzed in a retrospective follow-up study. With this surgical procedure the skin of the entire dorsum of the hand is excised and split-skin grafts harvested from thigh and buttock skin are then placed. Information was gathered from the medical records and questionnaires, and by physical examination. RESULTS: The mean follow-up time was 4.7 years. No recurrences of skin cancer were observed in the transplanted skin. The cosmetic appearance was acceptable, and there were few side effects. CONCLUSION: Resurfacing the back of the hand can be a successful treatment for carefully selected patients with multiple skin cancers on the back of the hand and can be used prophylactically in patients with severely actinically damaged skin.

Adult↗
PubMed1994

Functional human epidermal Langerhans cells that lack Birbeck granules.

Birbeck granules (BG) are cytoplasmic organelles that are only found in Langerhans cells (LC). The function of BG is still unclear, although it has been claimed that they are actively involved in receptor-mediated endocytosis and participate in the antigen-processing/presenting function of LC. We have identified a healthy white 29-year-old man whose LC completely lack the presence of BG as determined by electronmicroscopic studies. This was observed repeatedly using skin biopsy specimens taken from several places on the body during a period of 2.5 years. The absence of BG in these LG was documented further by the lack of staining with a BG-specific monoclonal antibody. Despite the complete lack of BG, LC were present in normal numbers, had all the usual morphologic characteristics, and were CD1a and human leukocyte antigen (HLA) class II positive. Two observations indicate that these BG-negative LC display normal antigen-presenting capacity. First, the individual could be sensitized by the hapten diphenylcyclopropenone. This was accompanied by a strong increase in the cell surface expression of HLA class II antigens on his LC, suggesting LC activation. Second, his epidermal cells elicited a normal positive response in an allogeneic mixed epidermal cell lymphocyte reaction. Together these observations strongly suggest that BG are not a prerequisite for normal LC function in vivo and in vitro.

Adult↗
PubMed1994

Detection of epidermodysplasia verruciformis-like human papillomavirus types in malignant and premalignant skin lesions of renal transplant recipients.

To evaluate the putative role of human papillomaviruses (HPV) in the development of skin cancer in renal transplant recipients, a series of skin biopsies from premalignant and malignant skin lesions was analysed using the polymerase chain reaction. Four different consensus primer pairs were used. HPV DNA was detected in five of 24 cases of squamous cell carcinoma, in one of three cases of Bowen's disease, in none of four basal cell carcinomas, in two of seven cases of actinic keratosis and in one of five cases of keratoacanthoma. Typing by direct sequencing of the amplified HPV DNA was possible in seven of nine cases, and revealed epidermodysplasia verruciformis (EV)-associated HPV types, or HPV types related to EV-associated types. Hence, HPV DNA could be detected in a significant proportion of (pre)malignant skin tumours in renal transplant recipients. The finding that some of the detected HPV types were as yet uncharacterized EV-related types, suggests that HPV DNA could be present in a higher percentage of lesions, and might be detected with refinement of the techniques.

Base Sequence↗
PubMed1994

Role of beta 1 integrins in cell spreading and migration of human nevomelanocytes and dysplastic nevi cells on collagen type IV and laminin.

We characterized beta 1 integrin subunit expression on three different cultures of benign human nevomelanocytes (NMC) and on four different cell cultures of human dysplastic nevus (DN) cells by flow cytometry analysis and examined their role in mediating cell spreading and migration on collagen type IV (CN IV) and laminin (LN) coated substrates by using a quantitative video image analysis system. The seven human NMC and DNC cultures expressed heterogeneous levels of beta 1, alpha 2, alpha 3 and alpha 6 integrin subunits. Image analysis showed that a significant increase (P < 0.001) in cell spreading and migration of the DN cells was induced on increasing coating concentrations of CN IV and LN. However, the NMC did not show an increase in cell spreading or migration on these substrates when compared to the substrates coated with denatured BSA only. The CN IV-induced cell spreading of the DN cells was significantly inhibited by anti-beta 1 mAb (AIIB2), anti-alpha 2 mAb (P1E6), or anti-alpha 3 mAb (P1B5), but not by mAb against alpha 6 integrin subunit (GoH3). The DN cell spreading on LN was not significantly inhibited by these mAbs. In contrast, the migration of the DN on CN IV and LN was significantly inhibited by anti-beta 1 mAb, anti-alpha 2 mAb, anti-alpha 3 mAb and anti-alpha 6 mAb. These data suggest that the alpha 2 and alpha 3 subunit are important for cell spreading of the DN on CN IV, although they are less important in cell spreading on the extracellular matrix component LN.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1994

Oral calcitriol as a new therapeutic modality for generalized morphea.

BACKGROUND: None of the commonly used drugs for the treatment of scleroderma appears to significantly influence the fibrotic stage of this disorder. Recently, a beneficial effect of the treatment with oral calcitriol (1,25 dihydroxyvitamin D3) in 10 patients with systemic sclerosis and four patients with morphea was described. This fact could be ascribed to the immunoregulatory effects of calcitriol observed in vitro and to inhibition of fibroblast growth. We treated three patients with extensive morphea with remarkable results. OBSERVATION: Three patients with generalized morphea were treated with calcitriol in an oral daily dose of 0.50 to 0.75 microgram. After 3 to 7 months of treatment, the mobility of the joints improved and the skin extensibility increased. No adverse effects were observed. The improvement persisted after discontinuation of therapy during a follow-up period of 1 to 2 years. CONCLUSION: Calcitriol showed a beneficial effect in generalized morphea during an open study. Double-blind, placebo-controlled trials are needed to assess its therapeutic value.

Administration, Oral↗