Young myotubes develop spots or macules of actin and alpha actinin under and adjacent to slender actin strands. Macules are found only before sarcomere formation. They contain cytoplasmic actin, small amounts of alpha actin, and alpha actinin but are devoid of tubulin, myosin and vimentin. In the electron microscope, they are seen to contain small filaments but no other organelles. Macules are ...

Schamberg disease, also known as Schamberg purpura or progressive pigmentary purpura, is characterized by orange-brown or reddish-brown macules/patches with overlaying purpuric spots simulating “cayenne pepper”. We report a 54-year-old Chinese woman with Schamberg disease presenting with purpuric macules and patches of varying sizes on the ankles, legs, and knees. The lesions were nonblanchable...

INTRODUCTION Dose-response skin prick tests are an important tool to standardise allergen extracts and to evaluate changes in skin test response as a consequence of allergen modifications. OBJECTIVES To evaluate in vivo and in vitro characteristics of 3 different types of extracts of Phleumpratense, Olea europaea, Parietaria judaica and Dermatophagoides pteronyssinus. MATERIAL AND METHODS T...

Human skin pigmentation is the product of two clines produced by natural selection to adjust levels of constitutive pigmentation to levels of UV radiation (UVR). One cline was generated by high UVR near the equator and led to the evolution of dark, photoprotective, eumelanin-rich pigmentation. The other was produced by the requirement for UVB photons to sustain cutaneous photosynthesis of vitam...

A 29-year-old man with a past history of appendectomy and morbid obesity, was seen for asymptomatic lesions that had appeared 7 to 8 years earlier on the hands and forearms. Multiple hypopigmented macules of 4 to 6 mm in diameter, with poorly defined borders and with surrounding erythema, were observed on the external aspect of both forearms and, more intensely, on the dorsum of the hands (Figu...

A 50-year-old woman with myotonic dystrophy (MD) presented with bilateral blurred vision. Visual acuity was 16/ 20 in both eyes. Slit lamp examination showed cortical and posterior subcapsular opacities in both lenses. Funduscopy showed depigmented changes at the macula, however, details were unclear due to the presence of cataract (Picture 1). Fundus autofluorescence (FAF) imaging clearly defi...