Biomedical subjects

J Veraart

Publications and source records attributed to J Veraart.

3 recordsLinked to original sources

PubMed1998

Evaluation of the vasoconstrictive effects of topical steroids by laser-Doppler-perfusion-imaging.

Corticosteroids are one of the most frequently prescribed local therapeutic treatments. Their potency and bioavailability are tested with different methods. One of the most accepted methods is the skin-blanching test designed by McKenzie. In this study we investigated whether the skin-blanching test designed by McKenzie for screening topically active corticosteroids, producing vasoconstriction, is sufficiently detectable by a laser-Doppler-perfusion-imager (LDPI). Eight sites in two rows on the right forearm of 10 healthy volunteers were treated with a topical glucocorticosteroid (clobetasol-17-propionate 0.05% (Dermovate), and the bloodflow at each site was measured by the LDPI at different timesteps. Four sites per row were chosen to evaluate the dependency of bioavailability according to anatomical differences due to skin changes within the forearm. Furthermore, half of the sites were occluded to demonstrate the difference between occluded and non-occluded sites in bioavailability. The results show that the LDPI can easily detect changes in bloodflow due to the vasoconstriction caused by topical corticosteroid. The results showed significant changes during the different measurements, with a maximum reaction 30 h after the application of the corticosteroid. The sites under occlusion showed a slower decrease of laser values than those without occlusion, so that it can be pointed out that occlusion prolongs the bioavailability of corticosteroids but does not influence the speed of onset. So far we conclude that this technique is a simple and non-traumatic method for assessing steroid potency. Blanching, as a result of vasoconstriction, can be quantified by LDPI measurement. However, LDPI measurements have to be compared with other techniques, such as the non-traumatic 133Xe washout technique, to find out if the two technologies respond in a similar way.

Administration, Topical↗

PubMed1998

Adhesion molecule expression in basal cell carcinoma.

Basal cell carcinomas (BCCs) are frequently associated with a peritumoral mononuclear infiltrate. Until now, the function of this inflammatory infiltrate and its possible role in the control of tumor growth is unclear. Mechanisms controlling endothelial and target cell adhesiveness for leukocytes are important features in the development of a specific local immune response. The expression and distribution of the adhesion molecules ICAM-1, VCAM-1 and E-selectin by microvascular endothelial cells and tumor cells, together with their leukocyte receptors LFA-1, VLA-4 and CLA respectively, were studied in 33 BCCs of different histological subtypes. In normal skin, ICAM-1 is expressed by resting endothelial cells, whereas VCAM-1 and E-selectin expression correlates with endothelial activation. The epidermis in normal conditions displays no ICAM-1, VCAM-1, or E-selectin expression. In BCC, endothelial ICAM-1 expression was only slightly increased compared to normal skin, whereas expression of endothelial VCAM-1 and E-selectin was low or absent in all BCCs examined. Peritumoral infiltrates contained mostly LFA-1-expressing lymphocytes, with minimal VLA-4 and CLA positivity. In none of the cases studied was adhesion molecule expression by BCC tumor cells identified. The lack of significant expression of adhesion molecules on peritumoral vascular endothelial cells and BCC tumor cells does not support the idea of specific, cell-mediated immunity being an important mechanism in limiting BCC tumor spread.

Biomarkers, Tumor↗

PubMed1995

Severe limb defects and craniofacial anomalies in a fetus conceived during acitretin therapy.

We describe a 20-week-old fetus with multiple congenital anomalies exposed to acitretin in the first trimester of pregnancy. Acitretin and its ethylester etretinate are both vitamin A congeners; drugs of this group are well-known teratogenic agents. Since the marketing of acitretin only one report on human teratogenicity associated with acitretin has been published. The present male fetus showed severe symmetric anomalies of upper and lower limbs, craniofacial anomalies, ear anomalies, and an atrioventricular septal defect (ASD). Although the craniofacial anomalies resemble the abnormalities described in classical "retinoic acid embryopathy," limb anomalies were seldomly reported after maternal use of vitamin A congeners. However, in laboratory animals limb defects were frequently observed after retinoid exposure in utero. This case emphasizes again that extreme care and precaution are needed before prescribing a potentially teratogenic drug to a fertile woman.

Abnormalities, Drug-Induced↗