Old World eyelid cutaneous leishmaniasis: a case report.

Dermatol Online J. 2005; 11(3): 29Mencía-Gutiérrez E, Gutiérrez-Díaz E, Rodríguez-Peralto JL, Monsalve-Córdova JLeishmania is a protozoa that may infect the skin, mucous, and viscera. The geographical distribution of cutaneous leishmaniasis (CL) is mainly determined by the sandfly vectors. The Old World type is mainly attributed to Leishmania major and Leishmania tropica, and in South of Europe only to Leishmania infantum. A 63-year-old woman, who noted a pimple on the external third of the left upper eyelid 6 months before. The lesion was nodular, well-defined and measured 1.1 cm in diameter and in height, simulating a basal cell carcinoma. It was surgically excised. CL diagnosis was made upon the histologic examination, which showed histiocytes with intracellular leishmania organisms. At 2 years followup, no evidence exists of cutaneous, mucous, or visceral involvement. Apart from carcinomas, nodular lesions with central ulceration are rare on the eyelid. A single cutaneous lesion of leishmania (oriental sore) has to be considered in the differential diagnosis, along with malignant eyelid neoplasms.

Effect of disjoining pressure on the drainage and relaxation dynamics of liquid films with mobile interfaces.

J Colloid Interface Sci. 2009 Apr 8; Tabakova SS, Danov KDThis work presents a generalized lubrication approximation of the drainage and relaxation of thin liquid films with tangentially mobile surfaces. The proposed model accounts for the dynamic effects and the role of surface forces of intermolecular origin. The van der Waals and hydrophobic attractive and the electrostatic and steric repulsive components of the disjoining pressure are included in the numerical calculations of the dynamics and relaxation of one-dimensional films. Different regimes of film drainage are discussed: regular and unstable mechanisms of thinning depending on the magnitude of the Reynolds number; pimple formation in the presence of large enough attractive surface forces; and stabilizing effects of the disjoining pressure repulsive components. In the case of relaxation, it is proven that the disturbances in the film thickness: decrease exponentially to the equilibrium state without taking into account the role of the disjoining pressure; increase very fast to the point of film rupture in the presence of attractive surface forces; oscillate with exponentially decreasing amplitudes towards the state of stable equilibrium when the electrostatic and steric repulsive forces are significant.

Unsmooth cuticles of soil animals and theoretical analysis of their hydrophobicity and anti-soil-adhesion mechanism.

J Colloid Interface Sci. 2006 Mar 15; 295(2): 490-4Jia XSoil adhesion is a natural phenomenon, and it is harmful to terrain machines and tillage equipment that have soil as their work medium, such as automobiles, tractors, earth-moving machines, spades, hoes, and plows. Soil adhesion increases motion resistance and energy consumption, quickens damage to the soil-engaging components, and lowers work quality. The biomimetic research has provided a promising method to solve the soil adhesion problem. In this work, the cuticles of typical soil animals were observed by scanning electron microscopy (SEM) and their wettability and mechanism of antiadhesion were analyzed in theory. The results of experimental observation have shown that the cuticles of soil animals have different unsmooth appearances, such as pimple-shaped, pit-like, and undee structures. But for the cross sections of the unsmooth cuticles, their common character is undee. Theoretical analysis has indicated that the larger the ratio of the amplitude of the wave to the period of the wave, the stronger the hydrophobicity, the more easily the composite interface between the liquid and the unsmooth cuticles forms, and the function of reducing soil adhesion of the unsmooth cuticles will be better.

Microvilli appear to represent the first step in actin bundle formation in Drosophila bristles.

J Cell Sci. 2004 Jul 15; 117(Pt 16): 3531-8Tilney LG, Connelly PS, Guild GMDuring bristle development the emerging bristle shaft, socket cell, and the apical surface of thoracic epithelial cells form tiny protuberances or pimples that contain electron-dense material located on the cytoplasmic surface of the pimple tip. In a few cases short actin filaments extend from this material into the cortical cytoplasm. When cultured in the presence of jasplakinolide, an agent that prevents filament disassembly, pimples elongate to form microvilli containing a core of crosslinked filaments. Emerging-bristle mutants delay cortical bundle formation and are aggregated by forked protein crossbridges. Using these mutants and enhancing core bundle formation with jasplakinolide we found that microvillar formation represents the first stage in the morphogenesis of much larger actin bundles in Drosophila bristle shaft cells. Evidence is presented showing that socket cells do not contain forked protein crossbridges, a fact that may explain why cortical bundles only appear in bristle shaft cells. Furthermore, as pimples and microvilli form in the absence of both forked and fascin crossbridges, we also conclude that neither of these crossbridges account for core bundle formation in microvilli, but there must exist a third, as yet unidentified crossbridge in this system. Immunocytochemisty suggested that this new crossbridge is not Drosophila villin. Finally, ultrastructural comparisons suggest that microspikes and microvilli form very differently.