Mycobacterium ulcerans infection imported from Australia to Missouri, USA, 2012.

Buruli ulcer, the third most common mycobacterial disease worldwide, rarely affects travelers and is uncommon in the United States. We report a travel-associated case imported from Australia and review 3 previous cases diagnosed and treated in the United States. The differential diagnoses for unusual chronic cutaneous ulcers and those nonresponsive to conventional therapy should include Mycobacterium ulcerans infection.

The absence of a microbiota enhances TSLP expression in mice with defective skin barrier but does not affect the severity of their allergic inflammation.

Evidence is accumulating to suggest that our indigenous microbial communities (microbiota) may have a role in modulating allergic and immune disorders of the skin. To examine the link between the microbiota and atopic dermatitis (AD), we examined a mouse model of defective cutaneous barrier function with an AD-like disease due to loss of Notch signaling. Comparisons of conventionally raised and germ-free (GF) mice revealed a similar degree of allergic skin inflammation, systemic atopy, and airway hypersensitivity. GF mutant animals expressed significantly higher levels of thymic stromal lymphopoietin, a major proinflammatory cytokine released by skin with defective barrier function, resulting in a more severe B-lymphoproliferative disorder that persisted into adulthood. These findings suggest a role for the microbiota in ameliorating stress signals released by keratinocytes in response to perturbation in cutaneous barrier function.

In vivo photoacoustic microscopy of human cutaneous microvasculature and a nevus.

In several human volunteers, photoacoustic microscopy (PAM) has been utilized for noninvasive cutaneous imaging of the skin microvasculature and a melanocytic nevus. Microvascular networks in both acral and nonacral skin were imaged, and multiple features within the skin have been identified, including the stratum corneum, epidermal-dermal junction, and subpapillary vascular plexus. Several vascular and structural differences between acral and nonacral skin were also observed in the photoacoustic images. In addition, a nevus was photoacoustically imaged, excised, and histologically analyzed. The photoacoustic images allowed for in vivo measurement of tumor thickness, depth, and microvasculature-values confirmed by histologic examination. The presented images demonstrate the potential of PAM to aid in the study and evaluation of cutaneous microcirculation and analysis of pigmented lesions. Through its ability to three-dimensionally image the structure and function of the microvasculature and pigmented lesions, PAM can have a clinical impact in diagnosis and assessment of systemic diseases that affect the microvasculature such as diabetes and cardiovascular disease, cutaneous malignancies such as melanoma, and potentially other skin disorders.

Melanoma: from patient presentation to pathology report.

Melanoma is an increasingly common and potentially fatal malignancy of the skin and some mucous membranes. Early detection and diagnosis based on patient or primary care physician awareness can potentially reduce both related morbidity and mortality. This article will detail a basic clinical approach to pigmented skin lesions followed by a discussion of pathologic analysis and staging.

A role for wingless in an early pupal cell death event that contributes to patterning the Drosophila eye.

Programmed cell death (PCD) is utilized in a wide variety of tissues to refine structure in developing tissues and organs. However, little is understood about the mechanisms that, within a developing epithelium, combine signals to selectively remove some cells while sparing essential neighbors. One popular system for studying this question is the developing Drosophila pupal retina, where excess interommatidial support cells are removed to refine the patterned ommatidial array. In this paper, we present data indicating that PCD occurs earlier within the pupal retina than previously demonstrated. As with later PCD, this death is dependent on Notch activity. Surprisingly, altering Drosophila Epidermal Growth Factor Receptor or Ras pathway activity had no effect on this death. Instead, our evidence indicates a role for Wingless signaling to provoke this cell death. Together, these signals regulate an intermediate step in the selective removal of unneeded interommatidial cells that is necessary for a precise retinal pattern.

Dmp53 protects the Drosophila retina during a developmentally regulated DNA damage response.

Ultraviolet (UV) light is absorbed by cellular proteins and DNA, promoting skin damage, aging and cancer. In this paper, we explore the UV response by cells of the Drosophila retina. We demonstrate that the retina enters a period of heightened UV sensitivity in the young developing pupa, a stage closely associated with its period of normal developmental programmed cell death. Injury to irradiated cells included morphology changes and apoptotic cell death; these defects could be completely accounted for by DNA damage. Cell death, but not morphological changes, was blocked by the caspase inhibitor P35. Utilizing genetic and microarray data, we provide evidence for the central role of Hid expression and for Diap1 protein stability in controlling the UV response. In contrast, we found that Reaper had no effect on UV sensitivity. Surprisingly, Dmp53 is required to protect cells from UV-mediated cell death, an effect attributed to its role in DNA repair. These in vivo results demonstrate that the cellular effects of DNA damage depend on the developmental status of the tissue.