Routine application of ex vivo confocal laser scanning microscopy with digital staining for examination of surgical margins in basal cell carcinomas.

BACKGROUND AND OBJECTIVES: Ex vivo confocal laser scanning microscopy (CLSM) allows histologic examination of native tissue based on tissue reflection and nuclear fluorescence staining. The newly introduced digital staining process almost perfectly mimics conventional hematoxylin and eosin (HE) slides. The aim was to evaluate the new method in clinical routine, with regard to quality of findings and time requirements, in the examination of surgical margins of basal cell carcinomas. PATIENTS AND METHODS: 78 patients with 101 basal cell carcinomas were prospectively enrolled. Surgery was performed either with complete margin control (n = 60) or as elliptical excision (n = 41). Immediately after excision specimens were scanned with CLSM and then routinely processed by conventional histopathology. Blinded evaluation of images and slides was performed by a dermatopathologist. RESULTS: Basal cell carcinomas were excellently recognizable by CLSM directly after excision, and the use of digital staining did not require any adjustment of the examiner's visualization preferences. CLSM images showed a sensitivity of 73.6 % and a specificity of 96.5 % compared to conventional HE stained slides. Erroneous findings were often due to limited assessment potential in cases where the epidermis could not be fully visualized. CONCLUSIONS: CLSM with digital HE staining is very well suited to diagnose basal cell carcinomas and their incision margins even under routine conditions and thus represents a tissue-saving alternative to rapid cryostat sectioning.

[Alopecia areata universalis under treatment with sitagliptin : Possible immunological effect of dipeptidyl peptidase-4 inhibitors?] / Alopecia areata universalis nach Sitagliptin-Einnahme : Mögliche immunologische Wirkung von Dipeptidylpeptidase-4-Inhibitoren?

A 64-year old man developed alopecia universalis after one month of treatment with metformin and sitagliptin, a dipeptidyl peptidase­4 (DPP-4) inhibitor. Diabetes treatment was changed to another genericum of sitagliptin and dapagliflozin. Following our recommendation, sitagliptin was interrupted and monotherapy with dapagliflozin was continued. After 6 weeks, sitagliptin was reassumed due to unsatisfactory diabetes control. Alopecia did not improve. We suspect a connection between DPP­4 inhibition and development of alopecia due to its immunological potential. We assume that the treatment interruption might have been too short to induce regrowth of hair. DPP­4 may result in both inhibition and activation of the immune system.

In vivo wound healing and dermal matrix remodelling in response to fractional CO(2) laser intervention: clinicopathological correlation in non-facial skin.

PURPOSE: Ablative fractional photothermolysis is a new concept for treatment of aged skin. Despite the low frequency of side effects there are now several reports about scarring, especially in non-facial regions like the neck. Our study aimed to investigate the in vivo wound healing process and remodelling in an area prone to scarring using a fractional ablative CO(2) laser with three different energy protocols. MATERIALS AND METHODS: Six patients with photo-damaged skin received a single fractional ablative treatment using a 250-µm scanning CO(2) laser. Three areas on the neck were treated with 50, 100 and 300 mJ/microbeam at densities of 200, 150 and 100/cm(2), respectively. Biopsies were taken from untreated skin (control) and 10 minutes, 3 days, 14 days, 21 days and 28 days post-intervention. RESULTS: Fractional ablation with higher energies resulted in increased total thermal damage. Overall, 50 mJ was effective up to the superficial dermis, 100 mJ up to the mid-dermis, and 300 mJ resulted in deep dermal ablation. The intensity of lymphocytic inflammation and dermal remodelling correlated with the total amount of thermal damage. At 300 mJ, granuloma was present and persisted for at least 4 weeks as opposed to clinical healing, which was completed < 2 weeks. CONCLUSIONS: With the above-mentioned low and medium parameter settings, ablative fractional photothermolysis is safe and effective in non-facial skin. However, dermal remodelling continues for up to 4 weeks, which should be the minimum space between treatment sessions. Higher energies may induce granuloma formation, possibly a sign of an overstrained remodelling capacity.

Histological evaluation of vertical laser channels from ablative fractional resurfacing: an ex vivo pig skin model.

Ablative fractional resurfacing (AFR) represents a new treatment potential for various skin conditions and new laser devices are being introduced. It is important to gain information about the impact of laser settings on the dimensions of the created laser channels for obtaining a safe and efficient treatment outcome. The aim of this study was to establish a standard model to document the histological tissue damage profiles after AFR and to test a new laser device at diverse settings. Ex vivo abdominal pig skin was treated with a MedArt 620, prototype fractional carbon dioxide (CO(2)) laser (Medart, Hvidovre, Denmark) delivering single microbeams (MB) with a spot size of 165 µm. By using a constant pulse duration of 2 ms, intensities of 1-18 W, single and 2-4 stacked pulses, energies were delivered in a range from 2-144 mJ/MB. Histological evaluations included 3-4 high-quality histological measurements for each laser setting (n = 28). AFR created cone-shaped laser channels. Ablation depths varied from reaching the superficial dermis (2 mJ, median 41 µm) to approaching the subcutaneous fat (144 mJ, median 1,943 µm) and correlated to the applied energy levels in an approximate linear relation (r(2) = 0.84, p < 0.001). The dermal ablation width increased slightly within the energy range of 4-144 mJ (median 163 µm). The thickness of the coagulation zone reached a plateau around 65 µm at energies levels above 16 mJ. The calculated volumes of ablated tissue increased with increasing energies. We suggest this ex vivo pig skin model to characterize AFR laser channels histologically.

Repin1 maybe involved in the regulation of cell size and glucose transport in adipocytes.

Replication initiator 1 (Repin1) is highly expressed in liver and adipose tissue and has been suggested as candidate gene for obesity and its related metabolic disorders in congenic and subcongenic rat strains. The cellular localization and function of Repin1 has remained elusive since its discovery in 1990. To characterize the role of Repin1 in adipocyte biology, we used siRNA knockdown technology to reduce the expression of Repin1 by electroporation of semiconfluent 3T3-L1 preadipocytes. Glucose transport, palmitate uptake as well as triglyceride content were measured. In paired samples of human visceral and subcutaneous adipose tissue, we investigated whether Repin1 mRNA expression is related to measures of fat accumulation and adipocyte size. We demonstrate that Repin1 increases during adipogenesis. RNA interference based Repin1 downregulation in mature adipocytes significantly reduces adipocyte size and causes reduced basal, but enhanced insulin stimulated glucose uptake into 3T3-L1 cells. Additionally, knockdown of Repin1 resulted in reduced palmitate uptake and significantly changed the mRNA expression of genes involved lipid droplet formation, adipogenesis, glucose and fatty acid transport. Furthermore, we found significant correlations between Repin1 mRNA expression in human paired visceral and subcutaneous adipose tissue and total body fat mass as well as adipocyte size. We have identified a potential role for Repin1 in the regulation of adipocyte size and expression of glucose transporters GLUT1 and GLUT4 in adipocytes.