Experimental testing of skin reactions to insulin detemir in diabetes patients naïve to insulin detemir.

BACKGROUND/AIMS: Sporadic reports on immediate and delayed cutaneous reactions to insulin detemir, a modern insulin analogue, have raised unsupported claims of allergy of type I, III and IV. The purpose of this experimental study using a provocative design was to elucidate the potential mechanisms behind such skin reactions. MATERIAL AND METHODS: A total of 40 patients with type 1 diabetes or insulin-requiring type 2 diabetes, all naïve to insulin detemir, were injected on the thigh with 0.l mL of insulin detemir (Levemir(®)) administered with an 8 mm needle at three different depths, i.e. intradermal, subdermal and subcutaneously. Saline was injected as control. Any cutaneous reactions were assessed after 10 and 30 min, after 24 and 48 h and after 7 days. Histopathology of positive reactions on day 7 was obtained. The study was randomized, controlled, double-blinded, and conducted in accordance with ICH-GCP guidelines. Blood flow was recorded with the Periflux PF5010, and skin colour (a*) with the DSMII colorimeter. RESULTS: Clinical reading, flowmetry and colorimetry consistently showed delayed reactions after intradermal insulin injection (35 of 40 patients reacted with mainly weak reactions, P<0.05), peaking after 48 h, contrasting no special reaction immediately after injection, except for reactions attributed to needle trauma. A total of 22 patients reacted on subdermal injection and 21 on subcutaneous injection. Histopathology on day 7 from 22 reactions in 15 patients showed a consistent pattern of inflammation with eosinophilia as typically observed in adverse skin reactions to a variety of medicines. Reactions were interpreted as non-specific biologic responses to the insulin different from direct toxic actions and classical allergic reaction patterns. Only one person registered itch/discomfort. A prick test vs. histamine reference excluded insulin detemir to be a pharmacological histamine releaser. Thus, provocative testing with insulin detemir produced delayed skin reaction but no immediate reaction. Measurement of circulating insulin detemir-specific antibodies by RIA before and after 3 months showed no increase. CONCLUSION: Non-allergic delayed skin reactions from intradermal and, to a minor degree, subdermal and subcutaneous injections of insulin detemir were frequent in this experimental study and showed a consistent histology pattern of inflammation with eosinophilia. Immediate reactions were not produced. The reactions are unlikely to be specific for insulin detemir, and other insulins should be studied in a similar provocative design.

Procollagen 1 - a marker of fibroblastic and fibrohistiocytic skin tumors.

BACKGROUND: When dealing with tumors of presumed fibroblastic or fibrohistiocytic origin, immunohistochemistry is traditionally done to exclude a tumor of non-fibroblastic or non-fibrohistiocytic nature, because a reliable marker of fibroblastic or fibrohistiocytic cell origin is still to be introduced. This study investigates whether procollagen 1 is a useful marker of skin tumors composed of cells derived from fibroblasts or fibrohistiocytes. MATERIALS AND METHODS: Twenty-nine different types of skin tumors, including tumors composed of spindle cells as well as some additional epithelial and melanocytic tumors, were stained immunohistochemically with antibodies against procollagen 1. The total number of cases tested was 154. RESULTS: Tumors composed of cells of fibroblastic or fibrohistiocytic origin in general showed a high expression of procollagen 1, whereas tumors composed of non-fibroblastic cells in general showed no expression. However, there were a few exceptions, e.g., leiomyosarcoma and desmoplastic melanoma. CONCLUSIONS: The study suggests that immunohistochemical staining for procollagen 1 is a valuable marker for skin tumors composed of spindle cells derived from fibroblasts or fibrohistiocytes. However, in cases of spindle cell tumors with a morphology suggesting malignancy, it is recommended to use a panel of antibodies, which besides procollagen 1 includes markers such as S100, CD68, CD34, h-caldesmon, and pancytokeratin.

Melanoma diagnosis by Raman spectroscopy and neural networks: structure alterations in proteins and lipids in intact cancer tissue.

Melanoma is the most aggressive skin cancer. The specificity and sensitivity of clinical diagnosis varies from around 40% to 80%. Here, we investigated whether the chemical changes in the melanoma tissue detected by Raman spectroscopy and neural networks can be used for diagnostic purposes. Near-infrared Fourier transform Raman spectra were obtained from samples of melanoma (n=22) and other skin tumors that can be clinically confused with melanoma: pigmented nevi (n=41), basal cell carcinoma (n=48), seborrheic keratoses (n=23), and normal skin (n=89). A sensitivity analysis of spectral frequencies used by a neural network was performed to determine the importance of the individual components in the Raman spectra. Visual inspection of the Raman spectra suggested that melanoma could be differentiated from pigmented nevi, basal cell carcinoma, seborrheic keratoses, and normal skin due to the decrease in the intensity of the amide I protein band around 1660 cm-1. Moreover, melanoma and basal cell carcinoma showed an increase in the intensity of the lipid-specific band peaks around 1310 cm-1 and 1330 cm-1, respectively. Band alterations used in the visual inspection were also independently identified by a neural network for melanoma diagnosis. The sensitivity and specificity for diagnosis of melanoma achieved by neural network analysis of Raman spectra were 85% and 99%, respectively. We propose that neural network analysis of near-infrared Fourier transform Raman spectra could provide a novel method for rapid, automated skin cancer diagnosis on unstained skin samples.

Skin changes following defibrillation. The effect of high voltage direct current.

Previously, electrical injuries have been suggested caused only by the concomitant heat developed during the passage of an electrical current. Recent experimental studies on fully anesthetized pigs and the study of one human case have, however, shown typical electrical alterations. The purpose of the present study was further to evaluate the histology of electrically induced changes in the skin in humans. In addition, supplementary in vivo methods for evaluation of skin changes as high-frequency ultrasound and Raman spectroscopy were used. The skin of 11 patients treated with a defibrillation of the heart was examined for macroscopic changes, the skin of eight of them also for histologic changes and for changes observable via supplementary methods. Immediately and 7 days after the defibrillation, fractions of a narrow red ring were observed along the periphery of the tin-foil electrode. Epidermis showed signs previously observed following electrical influence: segmental alterations often related to the openings of sweat ducts, darkstaining or "empty" nuclei and homogeneous cytoplasm, eosinophilic or pale. Dermis did not show the specific sign of electrical influence: deposits of calcium salts on dermal fibres, neither via histologic examination nor via high-frequency ultrasonography and Raman spectroscopy. Fractions of a narrow red ring along the periphery of the electrode showing histological signs of electric influence in epidermis thus appear to be characteristic of high voltage electrical injury.