Synthetic conduits

C. Ljungberg, G. Johansson-Ruden, K.J. Bostrom, L. Novikov, M. Wiberg, Neuronal survival using a resorbable synthetic conduit as an alternative to primary nerve repair. Microsurgery 19(6), 259-264 (1999)... 

Natural product synthesis poses the challenge to consider and develop new pathways of structural transformation. Natural products as targets for synthetic research possess a special fertility in this regard, because the structural channels of biosynthesis are not necessarily the conduits of organic synthesis. A. Eschenmoser19... 

The application is derived from new microsurgical techniques that can repair small blood vessels and nerves by sutures with optical equipment. The well-known synthetic implant materials for conduits of larger vessels (in-... 

The sensitivity of the original wire transport detector, besides being degraded by the high noise level, was also determined by the quantity of pyrolysis product that could find its way to the FID. Excluding synthetic polymers, which often quantitatively produce monomers on pyrolysis, many compounds yield only a few percent of volatile compounds and the higher boiling components of these often condense in the conduits and never actually reach the FID. Thus the FID may only sense a very small fraction of the products from the solute deposited on the wire. 

Methylcobalamin is completely different from adenosylcobalamin because it is essentially a conduit for synthetic reactions catalyzed by methyltransferases, illustrated in Scheme 2 for the case of methionine. These reactions depend on the supemucle-ophilicity of cob(I)alamin. In one case, this species removes a methyl group from A -methyltetrahydrofolate with the formation of methylcobalamin, and then transfers this group to the acceptor homocysteine, which results in the synthesis of methionine (see Scheme 2). 

Reversed segments of autologous saphenous vein can be used as appropriate conduits. Particularly in coronary revascularization, the internal mammary arteries and the radial arteries have widely been used [3]. However, autologous vessels may be insufficient for multiple or repeated bypasses and/or saphenous veins may have varicose degenerative alterations. Therefore, allograft arteries and veins as well as synthetic tubes have been developed, but they proved to be less satisfactory as conduits [4, 5] particularly, synthetic grafts with an internal diameter of 6 mm or less are prone to thrombus induction and occlusion [6]. 

Synthetic material and biological tissne conduits function to restore blood flow to an organ or limb when there is deprivation by occlusive disease, disruption by trauma, or surgical removal. 

Biofllms may be formed on the surfaces of implanted artificial organs, synthetic blood vessels, joint replacements, and indwelling catheters. The picture shows a cardiac assist device. Infection may occur during operation or via the prosthetic conduits. 

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