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Notes: We measure the complex conductivity of thin superconducting niobium films using coherent time-domain terahertz spectroscopy. Both real and imaginary part of the conductivity are measured simultaneously without referring to the Kramers–Kronig relations. We also measure the superconducting band gap directly from the onset of absorption and compare our results with theory.

Notes: We describe a case of carcinoma cuniculatum of the foot assessed by magnetic resonance scanning. The potential use of this imaging technique in the management of this condition is discussed.

Notes: Summary Background  Langerhans cells (LCs) play essential roles in the initiation and regulation of cutaneous immune responses mediated through their successful migration from the epidermis to draining lymph nodes while carrying antigen. Tumour necrosis factor (TNF)-α, a keratinocyte-derived cytokine, has recently been shown to play an important role in the mobilization of LCs from human epidermis. Although it is known that with age the immune system changes, the influence of increasing age on the function of human LCs has not been defined clearly.Objectives  To examine the influence of age on the ability of TNF-α to induce LC migration.Methods  Ten elderly (six men, four women; mean age 76 years, range 72–79) and 10 young (six men, four women; mean age 23 years, range 18–35) volunteers received intradermal injections of 200 U of human recombinant TNF-α diluted in sterile saline, and control injections of sterile saline alone, at each of two paired sites identified on photoprotected buttock skin. Two hours later, paired injection sites were excised by punch biopsy. One set of paired biopsies was processed for assessment of the frequency and morphology of epidermal LCs, following preparation of epidermal sheets and immunofluorescence staining for the LC marker CD1a. The remaining paired biopsies were processed in formalin and the inflammatory response to TNF-α was assessed by standard histological examination.Results  Mean ± SEM baseline values for LC frequency within epidermal sheets were significantly different between young (1156·3 ± 38·5 cells mm−2) and elderly subjects (835·7 ± 48·2 cells mm−2; P 〈 0·01). Intradermal injections of 200 U of TNF-α caused a significant reduction in the frequency of LCs in both elderly and young subjects (P 〈 0·01). However, the extent of TNF-α-induced LC migration was substantially different between the two groups, with a mean 9% reduction in LC frequency in elderly volunteers compared with a mean 23% decrease in young subjects. Exposure to TNF-α was associated with a perivascular polymorphonuclear infiltrate at 2 h in all young subjects; in contrast, only 50% of the elderly individuals showed evidence of such a response.Conclusions  There are significant differences between young and old skin with respect to both resting LC numbers and their response to TNF-α. These age-related changes in LC frequency and function may contribute to the altered cutaneous immune function observed in the elderly.

Notes: Background  The development of bullae accompanying acute oedema is a commonly observed clinical sign but has been rarely reported in the literature. Objectives  To document the clinical features and increase awareness of this entity. Methods  Retrospective case note review of 13 inpatient consultation cases seen in two dermatology departments. Results  Oedema blisters appear to be related to the speed of development rather than the degree of oedema, and respond rapidly to the reduction of the underlying oedema. Conclusions  Recognition of oedema blisters is important as they respond quickly and completely to treatment of the underlying oedema.

Notes: We present a brief account of the life and times of Dr Henry Grundy Brooke, a Manchester dermatologist and key figure in British dermatology in the nineteenth century. Our report highlights the achievements of a man whose contributions to dermatology continue to be of relevance in the new millennium.

Notes: Langerhans cells (LC) are members of the wider family of dendritic cells. LC reside in the epidermis where they serve as sentinels of the immune system, their responsibilities being to sample the external environment for changes and challenges and to deliver information (antigen) to responsive T lymphocytes within skin draining lymph nodes. The ability of LC to migrate from the epidermis to regional lymph nodes is therefore of pivotal importance to the induction of cutaneous immune responses. The journey that LC have to make from the skin has a number of requirements. Initially it is necessary that LC disassociate themselves from surrounding keratinocytes and are liberated from other influences that encourage their retention in the epidermis. Subsequently, migrating LC must successfully traverse the basement membrane of the dermal–epidermal junction and make their way, via afferent lymphatics, to draining lymph nodes. Effective entry into lymph nodes is necessary, as is correct positioning of cells within the paracortex. There is increasing evidence that both cytokines and chemokines, and their interaction with appropriate receptors expressed by LC, orchestrate the mobilization and movement of these cells. We here consider the parts played by these molecules, and how collectively they induce and direct LC migration.

Notes: Neovascularization appears to play an early and important part in the evolution of psoriatic plaques. We studied the distribution and production of two known angiogenesis factors, endothelial cell stimulating angiogenesis factor (ESAF) and vascular endothelial growth factor (VEGF), in the skin of patients with chronic plaque psoriasis and normal control subjects. Our results showed that tissue levels of ESAF and VEGF were significantly elevated in involved as compared with normal control skin (P = 0·006 and P 〈 0·0001, respectively). Tissue levels of ESAF and VEGF were also raised in involved skin as compared with uninvolved skin in patients with psoriasis (P = 0·001 and P 〈 0·0001, respectively). Tissue levels of ESAF and VEGF in plaques of psoriasis correlated closely with the clinical severity of psoriasis (r = 0·6 and r = 0·9, respectively). Serum levels of ESAF and VEGF were significantly raised in patients with psoriasis as compared with control subjects (P = 0·001 and P = 0·02, respectively). In vitro culture studies revealed that ESAF is produced by both keratinocytes and fibroblasts in approximately equal quantities in normal skin, whereas VEGF is secreted predominately by keratinocytes. A similar pattern is seen in both involved and uninvolved skin of patients with psoriasis. However, there is increased secretion of both factors in keratinocytes and fibroblasts from involved and uninvolved skin as compared with normal control skin (P 〈 0·001). The increased levels and secretion in plaques of psoriasis of two molecules, ESAF and VEGF, known to promote new blood vessel formation, suggest a pathogenetic role for them in this disease.

Notes: A trilayer deposition process for making high quality all-refractory Nb/AlOx/Nb Josephson junctions is described. The sputtering parameters were optimized to deposit very uniform Al films, less than 5 nm in thickness. We found that it was essential to keep the substrate temperature below 40 °C during Al deposition but not during Nb depositions. Rapid anodization of the Nb counterelectrode allowed us to use positive photoresist as an anodization mask even for submicron geometries. The dc superconducting quantum interference devices made with this process have the lowest intrinsic energy sensitivity reported to date for an all-refractory technology.

Notes: Superconducting Y-Ba-Cu-O (YBCO) films have been prepared by ex situ O2 annealing of multilayer films deposited on yttria-stabilized zirconia substrates by sequential rf diode sputtering of Y2O3, BaF2, and CuO targets, all of which are chemically stable. If sputtering is performed in an Ar ambient, the as-deposited films contain sufficient F to require its removal by annealing in wet O2 at about 800 °C or above before the superconducting YBCO phase can be formed by annealing in dry O2. However, sputtering in an Ar-O2 ambient greatly reduces the F content, making it possible to obtain the superconducting phase by annealing in dry O2 only. If the ambient contains about 20% O2, films with Tc (R=0)〉85 K can be prepared without wet-O2 annealing. The Ar-O2 process therefore has the potential for in situ preparation of superconducting YBCO films.