Tropical pyomyositis

A 22 year old male presented with symptoms of diffuse muscle pain and multiple abnormal laboratory findings that were eventually attributed to tropical myositis. Computed tomography scan was more reliable than ultrasound and served as a guide to needle aspiration and pathologic diagnosis.     

The geometry of triple-balloon dilation

Triple-balloon dilation (TBD) of a variety of luminal structures has been successfully, though infrequently, used. A mathematical model is presented for the selection of balloon sizes, and equations and tables are derived that allow the user to estimate more accurately the size of balloons needed for TBD of structures with large lumina. With TBD, an approximately circular lumen can be formed. Also, TBD allows smaller, higher-pressure balloons to be used instead of single, low-pressure, large balloons. However, multiple puncture sites may be required for TBD.     

Oxiagin from the Naja oxiana cobra venom is the first reprolysin inhibiting the classical pathway of complement

A basic glycoprotein oxiagin with molecular mass of 49.8 kDa was isolated from the venom of Central Asian cobra Naja oxiana. Partial amino acid sequence determination has shown that oxiagin belongs to reprolysins, a subfamily of animal metalloproteinases possessing a characteristic multidomain structure. Oxiagin was found to inhibit the classical pathway of the complement system. A study of the oxiagin influence on the different stages of the classical pathway showed that it inhibited the formation of C3-convertase. To achieve it, oxiagin binds to IgG on the surface of sheep erythrocytes sensitized with rabbit antibodies, thus, preventing the interaction of component C2 (without its inactivation) with immobilized C4b. IC50 for the inhibiton of classical pathway of complement system by oxiagin is 80 nM, while it does not affect the alternative pathway at concentrations up to 1.2 microM. Oxiagin possessed hemagglutinating activity towards sheep and rabbit erythrocytes, and this activity as well as the complement inhibition by oxiagin were suppressed by D-galactose. Oxiagin is the first representative of snake venom reprolysins that inhibits the complement system, utilizing non-proteolytic inhibiting strategy.     

Contribution of non-parenchymal cells to the performance of micropatterned hepatocytes

Hepatocytes within current bioartificial liver designs are unable to maintain the wide range of differentiated functions observed for the liver in vivo. As recent studies suggest, the absence of controlled interactions between hepatocytes and non-parenchymal cell populations of the liver may contribute to this hepatocyte dedifferentiation. The current study investigates the effect of Kupffer cells, fibroblasts, and human umbilical vein endothelial cells on hepatocyte function. To effectively study the effect of these heterotypic cell-to-cell interactions, it is necessary to establish a culture environment that controls the interactions between multiple cell types. Micropatterning is such a technique and was used in the current study. In addition, to elucidate the influence of soluble factors on hepatocyte function, the micropatterned results were compared with those of the trans-well culture system. Specifically, we compared the morphological and functional changes of hepatocytes cultured with these cells at varying ratios. Our results suggest that direct heterotypic cell-to-cell contact between hepatocytes and fibroblasts, and soluble factor exchanges between hepatocytes and human umbilical vein endothelial cells, significantly enhanced hepatocyte performance.