Notes: To diagnose allergic or irritant contact dermatitis, a clinically relevant contact allergy has to be demonstrated or ruled out, respectively. Although patch testing has been used for 100 years, it remains the method of choice for diagnosing contact allergy. A disadvantage of patch testing is that reading is subjective, based on inspection and palpation of the test area, implying that the assessment is subject to the reader's knowledge and experience. This study was carried out to investigate the accordance in reading patch test reactions between 5 dermatologists. 4 groups, each with 10 patients, participated. Within each group, all 10 were allergic to one and the same sensitizer; nickel, epoxy resin, ethylenediamine, or Kathon CG. The sensitizers were tested in serial dilutions and applied randomly to the back. The tests were read independently by the dermatologists in a blinded fashion. A protocol was used where the dermatologists had to note the presence of the morphological features erythema, infiltration, papules, vesicles, and bullae. In this way, it was possible to allocate the various readings into 4 classification systems, 3 European and one American, although the definition of the various classifications might differ slightly. Based on the readings and classifications, it was possible to calculate the degree of accordance within the 4 systems used. It was also possible to analyze the degree of accordance for the various morphological features. Total accordance for the 5 reading dermatologists for positive and negative test reactions was noted in 36% and 46%, respectively. The 3 European systems require homogenous erythema and infiltration for a reaction to be classified as allergic, while the American system also requires the presence of papules. Therefore, a higher number of allergic reactions (9%) was obtained with the European systems. Between the 4 classification systems, there were statistically significant differences, with the highest number of deviations for the system in which papules had discriminatory significance. When looking at the various morphological features, papules were most difficult to assess, followed by vesicles. Preferably, a classification system should not depend on papules. In conclusion, there was good accordance among the dermatologists in reading patch test reactions, since the 5 dermatologists read 82% of all tests similarly.

Notes: An increasingly common and effective method for the treatment of atherosclerotic disease in the coronary arteries is percutaneous transluminal coronary angioplasty (PTCA) and stenting. The stents are made of different metals. An increased rate of restenosis when using gold-plated stents has been shown. Contact allergy to gold is common in many countries. Recently, a study has shown an increased rate of contact allergy to nickel among patients with restenosis and a nickel-containing stent. The aims of our study were to investigate whether there was an increased rate of contact allergy to gold among patients with gold-plated stents and if this increased the risk of restenosis. 22 patients who had received a gold-plated stent were patch tested. An age- and sex-matched population of 88 patients, previously patch tested because of a suspected contact dermatitis, served as controls. In the stent group, 10/22 (45.5%) had a contact allergy to gold, in the control group 18/88 (20.5%); the difference is statistically significant (P = 0.04). There was no significant difference regarding frequency of restenosis. Our study indicates that there is a risk of sensitizing the patient when implanting a gold-plated stent. Further studies are needed to confirm these results and to evaluate whether there is an increased risk of restenosis.

Notes: Normal skin was cryoprotected by submerging it in a mixture of 30% dimethylformamide (DMF) in PBS or RPMI. Subsequently it was frozen in liquid propane gas. Cryosubstitution was carried out at −90°C by using methanol to which uranyl acetate or osmium tetroxide were added. The tissue was embedded in either Lowicryl K4M at −40°C or in Epon at +60°C. The- tissue was evaluated by its overall preservation of ultras-tructural details and by its labeling intensity alter incubation with either anti-clesmoglein or anti-type VII collagen monoclonal antibodies. The mixture of DMF and PBS caused an electron-dense precipitate within the cell. The overall morphology was better in Epon-embedded material than in K4M-embedclecl material. However, the labeling was best in K4M material. Regardless of whether the tissue was embedded in Epon or K4M, the addition of osmium tetroxide markedly reduced the degree of labeling.

Notes: In a double blind experimental study, 20 patients with a contact allergy to gold sodium thiosulphate were challenged intramuscularly with the chemically similar gold sodium thiomalate and with placebo. The most spectacular clinical reaction in the 10 patients given the active agent, was an epidermal and dermal flare up of healed patch-test reactions to the gold salts, as well as a high, but transient, rise in body temperature. Previous intradermal tests were similarly reactivated. In addition, toxicoderma-like rashes were observed in several cases, but a flare up of a previous contact dermatitis site was seen in one patient only. The specificity of the positive provocations was demonstrated.

Notes: The serotonergic neurotransmission was suggested to play an important role in the aetiology of alcoholism. This study explores the association between tryptophan hydroxylase (TPH)-alleles and Loudness Dependence of Auditory Evoked N1/P2 Potentials (LDAEP). The TPH is the rate-limiting biosynthetic enzyme in serotonergic pathway. The LDAEP is one of the best validated non-invasive indicators for serotonergic neurotransmission. A sample of 54 alcoholics was recruited. N1/P2 potentials were evoked by five different sound intensities. A dipole source analysis using BESA (brain electric signal topography) was performed and intensity dependence was computed. The TPH intron 7 polymorphism was determined by using PCR in DNA samples. There was a weak but significant association between low LDAEP and the L-TPH allele. No influence from an individual's history of alcohol dependence or a positive family history of alcohol dependence on LDAEP was found. The weak but significant relationship found between L-TPH-allele and high serotonergic neurotransmission may contribute to a more detailed neurobiological characterization of alcohol dependents using functional and genetic parameters.

Notes: An-11-day old girl was seen with brownish nodular lesions scattered over (he body with emphasis on the face and seal). Several lesions had started lo involute. Tissue was studied by histopathology, immunohistopathology, routine electron microscopy, and immuno-electron microscopy using cryosubstitution and embedding in K4M. Immunohistopathology revealed that the cells of the dermal infiltrate were Langerhans cells. They expressed Leu 6 and HLA-DR. On routine electron microscopy no Birbeck granules were (bund in the dermal cells. Birbeck granules in epidermal Langerhans cells were deformed and often situated next to laminated dense bodies. The latter expressed Leu 6 and HLA-DR. on immuno-electron microscopy. It was concluded that congenital self-healing reticulohistiocytosis is a benign Langerhans cell disease in which Birbeck granules are transformed to laminated dense bodies and possibly degraded by lysosomal enzymes.

Notes: Light microscopic studies have shown that nevus cell nests and melanoma nests are surrounded by basement membrane (BM) material containing type IV collagen and laminin. This study confirms this by electron microscopy and relates it to proteins which interact with the basement membrane. Nevi except for dysplastic and Spitz nevi, malignant melanomas, and melanoma metastases were studied by immunohistopathology, routine electron microscopy (EM), and immunoelectron microscopy. The lesions were incubated with monoclonal antibody (moAb) against type IV collagen, laminin, and the integrin α6 and studied by light microscopy. In addition, melanomas were studied by immuno-EM after incubation with a moAb against matrix metalloproteinase-2 (MMP-2). Nevus cell nests and melanoma nests are surrounded by BM material containing type IV collagen and laminin by immuno-EM. The BM material various in thickness and is amorphous. Type IV collagen, laminin, and MMP-2 are synthesized by melanoma cells as well as adjacent fibroblasts. Destruction or loss of the BM is not mandatory for melanoma invasion or even metastasis. Possibly the BM material is a protective wall for melanoma cells. Interactions between melanocytes and the extracellular matrix of which the BM is a part, can be traced back to the migration of melanocytes from the neural crest.