Characterization of pigmented dermo‐epidermal skin substitutes in a long‐term in vivo assay

In our laboratory, we have been using human pigmented dermo‐epidermal skin substitutes for short‐term experiments since several years. Little is known, however, about the long‐term biology of such constructs after transplantation. We constructed human, melanocyte‐containing dermo‐epidermal skin substitutes of different (light and dark) pigmentation types and studied them in a long‐term animal experiment. Developmental and maturational stages of the epidermal and dermal compartment as well as signs of homoeostasis were analysed 15 weeks after transplantation. Keratinocytes, melanocytes and fibroblasts from human skin biopsies were isolated and assembled into dermo‐epidermal skin substitutes. These were transplanted onto immuno‐incompetent rats and investigated 15 weeks after transplantation. Chromameter evaluation showed a consistent skin colour between 3 and 4 months after transplantation. Melanocytes resided in the epidermal basal layer in physiological numbers and melanin accumulated in keratinocytes in a supranuclear position. Skin substitutes showed a mature epidermis in a homoeostatic state and the presence of dermal components such as Fibrillin and Tropoelastin suggested advanced maturation. Overall, pigmented dermo‐epidermal skin substitutes show a promising development towards achieving near‐normal skin characteristics and epidermal and dermal tissue homoeostasis. In particular, melanocytes function correctly over several months whilst remaining in a physiological, epidermal position and yield a pigmentation resembling original donor skin colour.     

The War on Prevention II: Battle Metaphors Undermine Cancer Treatment and Prevention and Do Not Increase Vigilance

ABSTRACT

Bellicose metaphors for cancer are ubiquitous. But are they good metaphors for health communicators to use? Because metaphors can guide reasoning about abstract concepts, framing cancer with metaphors of battle, war, and enemies leads people to apply attributes of these concepts to cancer. The current research investigates how this affects inferences about cancer treatment, prevention, and monitoring. Battles and war are usually seen as being difficult. Indeed, reading about a person’s “battle” or “fight” against cancer makes cancer treatment seem more difficult (studies 1–4). One way to approach a battle is to surrender and give up control. Consistent with this implication, battle metaphors increase fatalistic beliefs about cancer prevention (e.g. believing that there is little one can do to prevent getting cancer; study 3). Finally, even though battles invoke vigilance and action, Study 4 failed to find that such metaphors motivate people to immediately see their doctor when imagining a cancer scare. These findings suggest that bellicose metaphors for cancer can influence the health beliefs of nonpatients in ways that may make them less willing to enact healthy behaviors     

Benign mesenchymal tumours and tumour‐like lesions in end‐stage renal disease

Aims: Mesenchymal neoplasms of the kidney are rare, and most represent sporadic angiomyolipomas. A few haemangiomas have been reported in end‐stage renal disease (ESRD) but, to date, no study has focused on the frequency and morphological spectrum of mesenchymal lesions in ESRD. Methods and results: We evaluated retrospectively 90 nephrectomy specimens with ESRD. Haemangiomas were detected in eight cases (8.8%; six males and two females; mean age: 55 years); four were multifocal and four had concurrent renal epithelial neoplasms. Lesions involved the medulla (three), cortex (two) or both (three), and the size range was 1–25 mm (mean 4.8 mm). Histologically, all were capillary haemangiomas with an at least focally detectable spleen‐like anastomosing pattern. All tumours stained positively for CD31 and FLI‐1, but none expressed pankeratin (KL‐1), podoplanin/D2‐40, HHV8 or GLUT‐1. Minute angiomyolipomas (mean size 2.3 mm) were detected in four patients (mean age 49.5 years). Tumour‐like smooth muscle proliferations were seen surrounding muscular arteries (eight), occasionally admixed with fat extending from the renal sinus mimicking angiomyolipoma. No similar tumours were found in 105 control kidneys. Conclusions: Benign haemangiomas are not uncommon in ESRD, but may be under‐recognized. They display distinctive morphology and should be distinguished from angiosarcomas and capillary‐rich renal cell carcinomas.