Multiple apocrine hidrocystomas successfully treated with botulinum toxin A.

Apocrine hidrocystomas, while rare, present predominantly as solitary papules occurring in the periocular region of the face. Various treatment modalities for these lesions exist depending on their size and location, but the management of multiple hidrocystomas can be more challenging. Recent reports illustrate that multiple eccrine hidrocystomas have been successfully treated with botulinum toxin A. Herein we describe the effective use of botulinum toxin A in a 29-year-old man with multiple facial apocrine hidrocystomas, which, to our knowledge, has not yet been reported in the English-language literature.

Stem cells in the skin and their role in oncogenesis.

Stem cells generate great interest because they hold the promise for treatment of various incurable diseases. Several distinct stem cell populations have been identified in each organ, including the skin. As the skin is the largest organ in the body and is easily accessible, cutaneous stem cells have raised significant hopes for being a rich source of easily available multipotent stem cells. Genetic alterations and mutations in stem cells are being proposed as initiation step in multiple cancers. Small populations of oncogenic stem cells termed as cancer stem cells or tumour-initiating cells have been identified in multiple tumours, including squamous cell carcinomas, and melanomas that can sustain tumour growth, underlie its malignant behaviour and initiate distant metastases. These cells are controlled and regulated by the same pathways that are also responsible for maintenance and differentiation of normal stem cells. Developing a targeted therapy against the oncogenic stem cells and dysregulated members of the signalling pathways may be the key to understanding and treating skin cancers like melanomas, for which we still do not have an effective treatment.

CT features of plexiform neurofibroma of the submandibular gland.

Plexiform neurofibroma of the submandibular gland is an extremely rare tumor. We report the CT findings in a 6-year-old girl with type 1 neurofibromatosis who had a histopathologically proven submandibular gland plexiform neurofibroma. A "branching" hypodense mass was noted on the CT scan infiltrating the submandibular gland and the adjacent spaces of the neck. CT could be extremely valuable in suggesting the diagnosis.

Spatial asynchrony and periodic travelling waves in cyclic populations of field voles.

We demonstrate evidence for the presence of travelling waves in a cyclic population of field voles in northern Britain by fitting simple, empirical models to spatially referenced time series data. Population cycles were broadly synchronous at all sites, but use of Mantel correlations suggested a strong spatial pattern along one axis at a projection line 72 degrees from North. We then fitted a generalized additive model to log population density assuming a fixed-form travelling wave in one spatial dimension for which the density at each site was offset in time by a constant amount from a standard density-time curve. We assumed that the magnitude of this offset would be proportional to the spatial separation between any given site and the centroid of the sampling sites, where separation is the distance between sites in a fixed direction. After fitting this model, we estimated that the wave moved at an average speed of 19 km yr-1, heading from West to East at an angle of 78 degrees from North. Nomadic avian predators which could synchronize populations over large areas are scarce and the travelling wave may be caused by density-dependent dispersal by field voles and/or predation by weasels, both of which act at a suitably small spatial scale.

The evolution of phylogenetic differences in the efficiency of digestion in ruminants.

This study investigates, for the first time (to our knowledge) for any animal group, the evolution of phylogenetic differences in fibre digestibility across a wide range of feeds that differ in potential fibre digestibility (fibre to lignin ratio) in ruminants. Data, collated from the literature, were analysed using a linear mixed model that allows for different sources of random variability, covariates and fixed effects, as well as controlling for phylogenetic relatedness. This approach overcomes the problem of defining boundaries to separate different ruminant feeding styles (browsers, mixed feeders and grazers) by using two covariates that describe the browser-grazer continuum (proportion of grass and proportion of browse in the natural diet of a species). The results indicate that closely related species are more likely to have similar values of fibre digestibility than species that are more distant in the phylogenetic tree. Body mass did not have any significant effect on fibre digestibility. Fibre digestibility is estimated to increase with the proportion of grass and to decrease with the proportion of browse in the natural diet that characterizes the species. We applied an evolutionary model to infer rates of evolution and ancestral states of fibre digestibility; the model indicates that the rate of evolution of fibre digestibility accelerated across time. We suggest that this could be caused by a combination of increasing competition among ruminant species and adaptation to diets rich in fibre, both related to climatically driven environmental changes in the past few million years.

Fluorescence of fungi in superficial and deep fungal infections.

BACKGROUND: Fluorescence of many fungi is noted when H&E stained sections are examined under a fluorescent microscope. In theory, this phenomenon could aid in the diagnosis of cutaneous and disseminated fungal infections without the delay associated with special stains. Seventy-six cases of superficial and deep fungal infections and 3 cases of protothecosis were studied to determine the clinical usefulness of this technique. RESULTS: In most cases, fluorescence was noted, but was not intense. Fluorescence of fungi did not correlate with the age of the specimen. In most cases, organisms in H&E stained sections were more easily identified with routine light microscopy than with fluorescent microscopy. CONCLUSION: This report suggests that in H&E stained skin specimens, fluorescent microscopy is of little benefit in the identification of fungal organisms.

Multiple hamartoma syndrome (Cowden's disease) associated with non-Hodgkin's lymphoma.

A 70-year-old woman with the multiple hamartoma syndrome is described. Diagnosis was based on the clinical presentation and histopathologic examination of cutaneous trichilemmomas. The case is reported to document the association of Cowden's disease with non-Hodgkin's lymphoma. This is the first known report of the occurrence of trichilemmomas in the sacral area. The literature concerning the association of the multiple hamartoma syndrome with malignancy is reviewed.

The composition of rime ice as an indicator of the quality of winter deposition.

Rime ice deposition and snow chemistry has been determined over a 4-year period on the summit of Cairngorm Mountain, NE Scotland. The direction of ice deposition reflected the dominant air mass movement over the summit. Sea salt concentrations in the rime ice were approximately 2.5 times greater than in snow deposited over the same period. Excess sulphate concentrations were double, and those of nitrate nearly four times higher. The direction of deposition influenced concentrations of excess sulphate and nitrogen species (nitrate and ammonium) in rime ice. The same directional effect was found in the snow chemistry indicating increased entrapment of pollutants, or a more polluted air mass, when it prevailed from a Southerly or Easterly direction. The potential surface reactions involving gaseous species of S and N may increase the ionic loading to the rime and reflect natural ionic enrichment of the rimed snowpack surface. Because of such phenomena, rime ice is proposed as a further indicator of winter air quality revealing important information on ionic interactions and total deposition flux measurement, especially at high altitudes.

Biochemical and haematological evidence of endotoxic shock in gnotobiotic lambs with watery mouth disease.

Eight gnotobiotic lambs deprived of colostrum were infected by mouth when two hours old with nonenterotoxigenic strains of Escherichia coli. All developed clinical signs of watery mouth disease and seven died within 24 hours. The mean concentrations of several blood constituents were determined in samples taken at intervals until 24 hours after infection in infected lambs and in four control lambs. The biochemical and haematological changes observed in the lambs developing watery mouth disease were those characteristic of endotoxic shock.

Dermatophytosis in the military.

Dr. Elston summarizes the US military experience with dermatophytosis in World War II and Vietnam and then brings us to the present and the current military situation with its increased role in humanitarian assistance.

Treatment of granuloma faciale with the pulsed dye laser.

Granuloma faciale is a chronic benign vasculitis that generally affects the skin of the face. The lesions are commonly refractory to therapy. A patient with long-standing granuloma faciale refractory to topical corticosteroid and dapsone therapy had an excellent response to treatment with the pulsed dye laser.

What's eating you? Pediculus humanus (head louse and body louse).

Head lice remain a common problem worldwide. As resistance to available therapeutic agents can emerge rapidly, there is a need for continued research to find new and better agents. Until better agents are available, clinicians may find that rotational therapy, using different agents, may help to slow the emergence of resistance. Physical modalities, such as mechanical nit and louse removal and occlusive agents to asphyxiate the lice, should not be ignored, especially in light of our limited therapeutic armamentarium. All therapeutic agents are doomed to failure if infestation is allowed to recur. Classmates, playmates, and family members of infested children should be inspected for head lice. Efforts should be directed at fomite control and nit removal. Louse infestation must be addressed as a community-wide problem. Body lice remain important vectors of disease. War, natural disaster, and poverty favor the spread of body lice. As we work to solve these seemingly eternal problems, we must develop better agents to treat infestation and prevent the spread of body lice.

Cutaneous schwannoma of the foot.

Schwannomas usually present as solitary subcutaneous tumors adherent to a peripheral nerve. A solitary cutaneous schwannoma presenting as a solitary cutaneous nodule on the foot of a 19-year-old male is described. This is an unusual presentation of schwannoma. Saucerized excision produced an excellent result with no adverse effect on function or cutaneous sensation.

Treatment of trichostasis spinulosa with a hydroactive adhesive pad.

Trichostasis spinulosa is a common skin condition that may be easier to diagnose than to treat. Successful treatment with the use of a hydroactive adhesive "deep cleaning" pad (Biore) is discussed.