Silicon Dioxide Particles Deposited in Vessels and Cartilage of the Femoral Head

Silicosis had been considered for decades as an illness with manifestations of lung fibrosis due to inhalation of overconcentrated SiO2 dust. To the best of our knowledge, studies have yet to report SiO2 deposits in any other tissues and organs. In the present case, while performing bilateral artificial total hip arthroplasty for one patient, we found that the articular cartilage of the bilateral femoral head was black. Therefore, specimens thereof were sent for pathological examination. Pathological examination (immunohistochemistry) and polarized light microscopy revealed the presence of considerable brown, acicular, rhombic, and crumb-like crystals. The crystals were mainly composed of SiO2. SiO2 could deposit in vessels and femoral head cartilage via blood circulation.

La dimetilarginina asimétrica, estructura e implicaciones patológicas / Asymmetric dimethylarginine, structure and pathological implications

La ateroesclerosis, es una enfermedad crónica, sistémica, inmuno-inflamatoria que afecta a la íntima arterial. La disfunción endotelial es la primera fase en la ateroesclerosis La disfunción endotelial está caracterizada por un daño y pérdida de la monocapa celular que cubre el interior de los vasos sanguíneos, denominada endotelio. Uno de los principales mediadores ara el mentenimieno de la integridad del endotelio, es el óxido nítrico (ON). La Dimetilarginina asimétrica (DMMA), es un inhibidor endógeno de la enzima sintasa del Óxido Nítrico (SON); se ha sugerido que DMAA sirve como un marcador de disfunción endotelial en enfermedades cardiovasculares. Asimismo, la DMAA representa un factor de riesgo para mortalidad cardiovascular, progresión de enfermedad crónica renal. Se ha encontrado valores elevados de DMAA en diferentes condiciones como hipercolesterolemia, aterosclerosis, hipertensión, insuficiencia renal crónica, insuficiencia crónica del corazón, diabetes y disfunsión eréctil.

Atherosclerosis is an immune inflammatory systemic, arterial disease. Endothelial dysfunction is the first stage in aterosclerosis. Atherosclerosis develops because of reactions occurring in vessel wall beginning with response to enothelial injury. Endothelial dysfunction is characterized with impairment and loss of monolayer cells covering the inside of the vessels, which is enothelium. One of the main mediators for the maintenance of the integrity of endothelium is Nitric Oxide (NO). The asymmtric Dimethilarginine (ADMA), is an endogenous inhibitor of the enzyme Nitric Oxide Synthase (NOS). ADMA has been suggested to serve as a biomarker of endothelial dysfunction in cardiovascular diseases. ADMA is a risk factor for endothelial dysfunction, cardiovascular mortality, and progression of chronic kidney disease. Elevated values of ADMA have been found in hypercholesterolemia, atherosclerosis, hypertension, chronic renal insufficiency, heart chronic failure, diabetes and erectile dysfunction.