Kolloide in der Intensivmedizin

Die Normovol?mie ist essentiell im Rahmen der Behandlung von Patienten w?hrend Narkose, in der Notfall- und Intensivmedizin. Grunds?tzlich stehen zur Volumensubstitution kristalloide L?sungen und kolloidale L?sungen zur Verfügung. In Europa ist die kombinierte Verwendung beider L?sungen anerkannter Standard. Differenzierte überlegungen zum Einsatz der verschiedenen Kolloide sind beim kritisch kranken Erwachsenen notwendig, da sowohl Humanalbumin als auch die künstlichen Kolloide Dextran, Gelatine und Hydroxyethylst?rke spezifische Effekte und typische Nebenwirkungen haben. Diese spielen unter den Gegebenheiten, die der Intensivpatient mit Organdysfunktionen und Organversagen aufweist, eine besondere Rolle. Die klinisch relevanten Daten zu allen Substanzen werden unter besonderer Berücksichtigung der Intensivmedizin diskutiert.

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A possible mechanism for decrease in serum thyroxine level by polychlorinated biphenyls in Wistar and Gunn rats.

We have previously demonstrated that in mice, the decrease in serum thyroxine (T(4)) level by polychlorinated biphenyls (PCBs) occurs without an increase in the UDP-glucuronosyltransferase (T(4)-UDP-GT) for T(4) glucuronidation, although the PCB-induced decrease in rats is generally thought to occur through induction of T(4)-UDP-GT, UGT1A1, and UGT1A6. In the present study, to further clarify the relationship between the decrease in serum T(4) level and the increase in UGT1A activity by PCB in rats, we examined the relationship using Wistar rats and Gunn rats, a mutant strain of Wistar rats deficient in UGT1A isoforms. The serum total T(4) level was markedly decreased not only in the Wistar rats but also in the Gunn rats 4 days after treatment with a PCB, Kanechlor-500 (KC500, 100 mg/kg) or 2,2',4,5,5'-pentachlorobiphenyl (PentaCB, 112 mg/kg), and there was no significant difference in magnitude of the decrease between the two rat strains. At the same time, the level and activity of T(4)-UDP-GT were significantly increased by treatment with either KC500 or PentaCB in Wistar rats but not in Gunn rats. In addition, no significant change in the level of serum total triiodothyronine (T(3)) and thyroid-stimulating hormone by the KC500 treatment was observed in either Wistar or Gunn rats. Furthermore, significant decrease in the activity of hepatic type-I deiodinase, which mediates the deiodization of T(4) and T(3), by treatment with KC500 or PentaCB was observed in both Wistar and Gunn rats. From the serum of KC500- or PentaCB-treated Wistar and Gunn rats, mono- and di-hydroxylated PCB metabolites, which would bind to T(4) binding serum protein (transthyretin), were detected. In conclusion, the present results suggest that the decrease in serum total T(4) level by either KC500 or PentaCB in Gunn rats was not dependent on the increase in hepatic T(4)-UDP-GT activity. The findings further suggest that the PCB-mediated decrease in serum T(4) level might occur, at least in part, through formation of the hydroxylated PCB metabolites. Furthermore, even in Wistar rats, the PCB-mediated decrease in serum T(4) level might occur not only through the increase in hepatic T(4)-UDP-GT but also via formation of hydroxylated PCB metabolites.     

Automatic titration and calculation by predictive equations for the determination of therapeutic continuous positive airway pressure for obstructive sleep apnea

BACKGROUND: It is unknown to what extent therapeutic continuous positive airway pressure (CPAP) levels obtained by various methods for the treatment of obstructive sleep apnea syndrome (OSAS) differ. This study aimed to explore the relationships among pressures titrated by an automatic CPAP (APAP) device and those calculated using different predictive equations, and to compare different ranges of calculated pressures with pressure values titrated by APAP. METHODS: In 140 OSAS patients, the 95th percentile pressure delivered by an APAP device (AutoSet T; ResMed; Sydney, NSW, Australia) during polysomnography, and pressures calculated by three equations (equation 1, Hoffstein and Miljetig [1994]; equation 2, Sériès et al [2000]; and equation 3, Stradling et al [2004]) were compared. RESULTS: Titrated and calculated pressures were weakly correlated. Significant differences were found between the mean (+/- SD) pressures (11.1 +/- 1.6, 8.3 +/- 1.8, 10.5 +/- 1.6, and 10.3 +/- 1.3 cm H(2)O, respectively) for 95th percentile APAP, and pressures calculated by equations 1, 2, and 3, except between values calculated by equations 2and 3. Differences between the calculated and APAP-derived pressures were negative for the low calculated values, and were progressively attenuated, or became positive, for the high values. The differences were smallest for calculated pressures from 11 to > 13 cm H(2)O, which were represented to a greater extent among the values calculated by equations 2 and 3 than by those calculated by equation 1. CONCLUSIONS: Considerably different therapeutic CPAP levels may be determined using various methods. The differences between the calculated and APAP-derived pressures are largest for calculated values of < 9 or > 15 cm H(2)O. The clinical consequences of these findings deserve further evaluation. Caution is still required before treating OSAS patients with calculated pressures.     

Effect of various polishing systems on the surface roughness and phase transformation of zirconia and the durability of the polishing systems

Statement of problem

Although many systems are used to polish zirconia, a comparison of the performance of zirconia and feldspathic porcelain polishing systems is lacking.

Low-Density Lipoprotein Apheresis Using the Liposorber System: Features of the System and Clinical Benefits

Abstract: LDL apheresis using the Liposorber system is indicated for use to remove selectively LDL from the plasma of hypercholesterolemic patients for whom diet and maximum cholesterol-lowering drug therapy have been ineffective or not tolerated. The dextran sulfate immobilized to porous cellulose beads is contained in the adsorption column as the adsorbent. The dextran sulfate has a structure similar to that of the LDL receptor and seems to act as a type of pseudoreceptor for LDL. There have been reported a number of clinical benefits using the Liposorber system for drug refractory hypercholesterolemic patients. Among them, the improvement of endothelial cell function of coronary and brachial arteries by a single treatment is the focus of the world's attention. Moreover, it is also noteworthy that LDL apheresis reduced the incidence of the cardiac events by 70% compared to drug therapy alone. In addition to the clinical benefits of the Liposorber system on familial hypercholesterolemia (FH), the preliminary data suggest that LDL apheresis may improve arteriosclerosis obliterans (ASO) of the lower extremities and focal glomerular sclerosis (FGS).