The authors describe the design of the first multiprobe cryosurgical system (AccuProbe system). Compared with prior conventional cryosurgical devices, the new system has the following ...characteristics: 1) generation of subcooled liquid nitrogen, 2) optional use of up to five independently operated and controlled cryoprobes, 3) use of disposable probes of various sizes and shapes, 4) more accurate placement of the cryoprobes in the lesions due to probe miniaturization (3.4 mm in overall diameter), and 5) higher capacity freezing, which supports more accurate and controllable tissue temperatures. With the use of the newly developed system, numerous cryosurgical procedures, including those in the prostate, brain, and liver, have been successfully performed.
Water, Temperature and Life [and Discussion] Franks, F.; Mathias, S. F.; Hatley, R. H. M. ...
Philosophical transactions of the Royal Society of London. Series B, Biological sciences,
01/1990, Letnik:
326, Številka:
1237
Journal Article
Recenzirano
Cold is the fiercest and most widespread enemy of life on earth. Natural cold adaptation and survival are discussed in terms of physicochemical and biochemical water management mechanisms, relying on ...thermodynamic or kinetic stabilization. Distinctions are drawn between general effects of low temperature (chill) and specific effects of freezing. Freeze tolerance is a misnomer because tolerance does not extend to the cell fluids. Freezing is confined to the extracellular spaces where it acts as a means of protecting the cytoplasm against freezing injury. Freeze resistance depends on the phenomenon of undercooling, a survival mechanism that relies on the long-term maintenance of a thermodynamically highly unstable state. Correct water management involves many factors, among them the control of membrane composition and transmembrane osmotic equilibrium, the biosynthesis of compounds able to afford protection against injury through freeze desiccation and the availability (or inactivation) of biogenic ice nucleation catalysts.
Interactions between human erythrocyte ghosts and small unilamellar vesicles consisting of various lipids and containing high intravesicular concentrations of calcein were studied. The entrapped ...marker leaked out under the influence of erythrocyte ghost in dependence on ghost and vesicle concentration, phospholipid composition as well as cholesterol content of the liposomes. Small unilamellar vesicles composed of sphingomyelin/cholesterol mixtures at a molar ratio of 1:1 are less permeable than those prepared from other phospholipids in the presence of erythrocyte ghosts. The amount of ghost associated liposomal lipid was measured by addition of cholesteryl 14Coleate. It was shown to be minimal compared to the transfer of 14Ccholesterol between liposomes and ghosts. The half-time of the transfer process was also increased by incorporation of sphingomyelin into the liposomes, the retarding effect being apparent at levels of 5 mol% sphingomyelin.
Referate Bachmann, G. W.; Bauereisen, E.; Baumann, Christian ...
Pflüger's Archiv für die gesamte Physiologie des Menschen und der Tiere,
9/1964, Letnik:
281, Številka:
1
Journal Article
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