Characteristics, risk factors and treatment reality in livedoid vasculopathy - a multicentre analysis.

BACKGROUND: Livedoid vasculopathy (LV) is a rare cutaneous thrombotic disease. It is characterized by occlusion of dermal vessels resulting in livedo racemosa, ulceration and atrophie blanche. Clear guidelines for diagnosis and treatment are missing. OBJECTIVE: The purpose of this study was to better characterize epidemiology, clinical appearance and treatment reality of LV in a well-defined patient cohort. METHODS: The cohort was allocated within a prospective, multicentre, phase IIa trial that investigated the effect of rivaroxaban in LV. RESULTS: Analysis of 27 patients revealed that LV patients had an increased Body Mass Index (BMI; 11/27), hypertension (19/27) and increased levels of lipoprotein (a) (5/12) and homocysteine (10/12) in the blood. The female-to-male ratio was 2.1 : 1, and the median age was 53.0 years [interquartile range (IQR) 40.5-68]. Investigation of the clinical appearance found that 82% of patients had livedo racemosa, and the ankle region was most likely to be affected by ulceration (56-70%). The analysis of patient treatment history showed that heparin was most effective (12/17), while anti-inflammatory regimens were, although often used (17/24), not effective (0/17). CONCLUSION: We add clinical clues for a data supported diagnosis of LV, and we provide evidence that anticoagulants should be administered in monotherapy first line (EudraCT number 2012-000108-13-DE).

Radiosensitization by BRAF inhibitor therapy-mechanism and frequency of toxicity in melanoma patients.

BACKGROUND: Recent evidence suggests that ionizing radiation may be associated with unexpected side-effects in melanoma patients treated with concomitant BRAF inhibitors. A large multicenter analysis was carried out to generate reliable safety data and elucidate the mechanism. METHODS: A total of 161 melanoma patients from 11 European skin cancer centers were evaluated for acute and late toxicity, of whom 70 consecutive patients received 86 series of radiotherapy with concomitant BRAF inhibitor therapy. To further characterize and quantify a possible radiosensitization by BRAF inhibitors, blood samples of 35 melanoma patients were used for individual radiosensitivity testing by fluorescence in situ hybridization of chromosomal breaks after ex vivo irradiation. RESULTS: With radiotherapy and concomitant BRAF inhibitor therapy the rate of acute radiodermatitis ≥2° was 36% and follicular cystic proliferation was seen in 13% of all radiotherapies. Non-skin toxicities included hearing disorders (4%) and dysphagia (2%). Following whole-brain radiotherapy, rates of radiodermatitis ≥2° were 44% and 8% (P < 0.001) for patients with and without BRAF inhibitor therapy, respectively. Concomitant treatment with vemurafenib induced acute radiodermatitis ≥2° more frequently than treatment with dabrafenib (40% versus 26%, P = 0.07). In line with these findings, analysis of chromosomal breaks ex vivo indicated significantly increased radiosensitivity for patients under vemurafenib (P = 0.004) and for patients switched from vemurafenib to dabrafenib (P = 0.002), but not for patients on dabrafenib only. No toxicities were reported after stereotactic treatment. CONCLUSION: Radiotherapy with concomitant BRAF inhibitor therapy is feasible with an acceptable increase in toxicity. Vemurafenib is a more potent radiosensitizer than dabrafenib.

Evaluation of the German guideline for chronic pruritus: results of a retrospective study on 385 patients.

OBJECTIVES: The first guideline for the treatment of chronic pruritus was published in 2005. The recommendations are based mainly on case series studies or expert opinions. This retrospective study aimed at analyzing the outcome of treatment according to the German guidelines in a representative cohort of patients. METHODS: 385 consecutive patients with chronic pruritus were evaluated for therapeutic outcome. RESULTS: 268/385 patients (69.6%) reported an antipruritic effect while 117/385 (30.4%) showed no response. Three therapeutic steps were undertaken by 40.3% of the responding patients. CONCLUSIONS: Treating pruritus patients according to the German guideline achieved a high response rate. A prolonged treatment period with multiple therapeutic steps was needed by a high number of patients due to the lack of specific antipruritic substances. Given that multiple therapy steps produce a high disease and economic burden, novel target-specific therapies are eligible.

Two-step negative enrichment of CD4+ and CD8+ T cells from murine spleen via nylon wool adherence and an optimized antibody cocktail.

We developed a method to highly purify CD4+ and CD8+ T cells from murine spleen by negative enrichment strategy. Single-cell suspensions of spleen cells were depleted from erythrocytes by ammonium chloride-mediated lysis. The obtained cell suspension contained approximately 28% CD4+ cells and 14% CD8+ cells. Passing of these cells over a nylon wool column removed up to 75% of all cells, leading to a suspension containing approximately 50% CD4+ and 23% CD8+ cells. These cells were further purified by a single immunomagnetic depletion step using a panel of eight antibodies in combination with MACS magnetic beads and an autoMACS machine. After purification, cells were viable and mostly non-activated based on the expression of activation markers and did not or only minimally respond to polyclonal stimuli such as soluble anti-CD3 antibodies or Concanavalin A. With this method, 19-38% of all CD4 cells and 10-29% of all CD8 cells in a spleen cell suspension were recovered at the mentioned purity. The whole procedure is fast (<4 h of preparation), simple and cost effective, as all antibodies and the magnetic beads have been titrated to the minimal concentration needed for purification. The method is highly reproducible, routinely leading to CD4+ cells with >97% purity (range 97.4-99%) and CD8+ cells with >96% purity (range 95.6-96.7%). The described protocol should facilitate studies aiming at the physiology of "untouched" murine T cells.

The early chick embryo as a model to evaluate cardiovascular effects of adrenaline and nicotine.

During the early stages of development, chick embryos offer a good model for vascular and circulatory studies. The present experiments were carried out with nicotine and adrenaline as validation substances, to test whether this system can be applied to evaluate functional cardiovascular effects. Nicotine was injected into the yolk before incubation and administered topically on different days of incubation. Adrenaline was injected intravascularly to evaluate functional effects (heart rate and heart arrhythmia). Mortality rates following nicotine and adrenaline application were determined. An injection of nicotine prior to incubation resulted in a dose-related increase in undeveloped chick embryos, and the topical application led to hyperaemia and haemorrhages. The body weight of the embryos was reduced due to the repeated nicotine application. After iv injection of adrenaline, heart rate increase and the occurrence of heart arrhythmia showed dose-response effects and the mortality rate was three-fold higher as compared with the controls. These results show that, following the application of adrenaline and nicotine, effects on the early chick embryo are similar to those seen in other test systems. In addition to its use in toxicology, this model is suitable for the evaluation of functional cardiovascular effects. The system does not require living animals, and uses stages of development during which the nervous system is still immature.

Time-course analysis of type II cell hyperplasia and alveolar bronchiolization in rats treated with different particulates.

In this study, we compared the morphological reaction patterns in rat lungs following a single intratracheal instillation of 20 mg quartz, 20 mg coal mine dust (15.3% quartz), or 25 mg talc. Control animals received a single dose of 0.5 ml saline solution intratracheally. Investigations by light microscopy, morphometry, and DNA image cytometry were carried out 3, 6, 12, and 18 mo after dust administration. During the investigation period, we observed a temporary increase in the number, area, and proliferative activity of the type II cells, which differed in intensity among the three dusts. After 18 mo, however, type II cells in treated animals did not differ from control animals. On the other hand, the expansion of a multifocal alveolar bronchiolization as putative preneoplastic lesion had progressed enormously by the end of the test (1-3% of the investigated lung area). Consistent with this, the proliferative activity of the epithelial cells in terminal bronchi of the coal mine dust- and quartz-treated animals was enhanced by the end of the 18-mo investigation period, while the reaction to talc was minimal (0.2% of totally investigated lung area). Our data suggest that in bronchiolo-alveolar regions, especially in the epithelium of terminal bronchi, there is an overshoot regeneration after cell damage that leads to an alveolar bronchiolization.

Clara-cell hyperplasia after quartz and coal-dust instillation in rat lung.

Bronchiolo-alveolar hyperplasia of type II cells in rat lungs after particle exposure is a well-known preneoplastic lesion. The Clara cell, stem cell of the bronchiolar epithelium and the main carrier of cytochrome P-450 isoenzyme system in the lung, has barely been evaluated with regard to this effect. The aim of this study was to examine Clara-cell hyperplasia after particle exposure and to characterize cell proliferation and its normal function. Female Wistar rats were intratracheally instilled with coal dust samples of variable quartz content, quartz (DQ12), titanium dioxide, or saline solution containing 0.5% Tween 80. After 126-129 wk, all coal mine dust- and quartz-exposed animals developed Clara-cell hyperplasia: up to 0.48% of the total lung area, which was significantly increased compared to titanium dioxide (p <.05) and control (p <.03) animals. Proliferation and hyperplasia of bronchiolar Clara cells by coal dusts was independent of their quartz content. The lack of proliferating cell nuclear antigen staining in most of the hyperplastic Clara cells suggests that following damage of alveolar epithelial cells, Clara cells migrate in and remodulate the alveolar epithelium. After the migration they keep their function in the xenobiotic metabolism, as shown by expansion of CYP2E1 active Clara cells. The minor development of Clara-cell hyperplasia in titanium dioxide-treated rats indicates that this is not a general particle effect, and is possibly due to its lower toxicity to epithelial cells.