Bariumchlorid-Vergiftung

Ohne Zusammenfassung     

Vergleich des Azetylens und Stickoxyduls in ihrer Wirkung auf verschiedene Teile des Zentralnervensystems

Zusammenfassung Es wird die Wirksamkeit von Stickoxydul und Azetylen im Katzenversuche verglichen. Für die Narkosetiefe ist nicht die Anzahl der in der Körperflüssigkeit gelösten Moleküle maßgeblich, sondern es erweist sich, daß das Azetylenmolekül 1,8–2,7 mal (unter Berücksichtigung der Wasserlöslichkeit) bzw. 2,4–3,6 mal (unter Berücksichtigung der Öllöslichkeit) so wirksam auf das Rückenmark ist, wie das Stickoxydulmolekül.Am Kreislauf ist eine Reizung des Vasomotorenzentrums durch Stickoxydul höchstens angedeutet.Mit 1 Kurve.     

Neugeborenenscreening auf Zystische Fibrose (CF)

Die Erkrankung Zystische Fibrose (CF) erfüllt wesentliche Kriterien, die die Einführung eines allgemeinen Neugeborenenscreenings zur Frühdiagnose rechtfertigen. Bei der Bewertung der bisherigen weltweiten Erfahrungen zahlreicher Pilotprogramme zum CF-Screening und in der Abw?gung von Vor-und Nachteilen besteht jedoch zur Zeit noch kein Konsens. Hinsichtlich der Auswirkungen auf den Verlauf und die Prognose der Erkrankung geben jüngste Ergebnisse mehrerer Beobachtungsstudien und des kontrollierten Screeningprogramms in Wisconsin nun ausreichend Hinweise, die einen klaren Vorteil eines CF-Neugeborenenscreenings zumindest hinsichtlich des Ern?hrungszustandes zeigen. Darüber hinaus werden jedoch auch andere positive Auswirkungen einer Frühdiagnostik sowohl von vielen Experten als auch von beteiligten Selbsthilfeorganisationen als wichtiges Argument für ein generelles CF-Screening angeführt. Zum gegenw?rtigen Zeitpunkt wird übereinstimmend empfohlen, bestehende Pilotprogramme fortzuführen und weitere wissenschaftlich begleitete CF-Screeningprojekte zur Fortentwicklung einzuführen. Dabei müssen jedoch zur Vermeidung potenzieller Risken strenge Richtlinien und Vorgaben eingehalten werden. Eine interdisziplin?re Zusammenarbeit vieler beteiligter Fachrichtungen (Labor, Behandlungszentrum und Nachsorgenetzwerk, genetische Beratung, psychosoziale Dienste etc.) muss gew?hrleistet sein.     

Circadian variation of granulocyte colony stimulating factor levels in man

Glucocorticoids dose-dependently increase plasma levels of granulocyte colony stimulating factor (G-CSF). Based on the marked circadian rhythm of cortisol levels, we hypothesized that plasma levels of G-CSF may also show a diurnal rhythm. A prospective study was conducted in 12 healthy young volunteers. Blood samples were obtained every 2 h over 24 h. G-CSF levels averaged 18.0 ng/l (CI 13. 1-22.9) at 8.00 am, increased continuously and reached peak values at 10.00 p.m. Individual harmonic regression analysis showed a clear circadian rhythm. The individual differences between nadir and peak levels averaged 54% (CI 43-65%). This pronounced diurnal rhythm of G-CSF levels may help understand the circadian changes in circulating stem cells, bone marrow DNA synthesis, or bone marrow toxicity induced by some chemotherapeutic agents.     

Comparison of the effects of ketamine and memantine on prolactin and cortisol release in men. a randomized, double-blind, placebo-controlled trial.

N-methyl D-aspartate (NMDA)-antagonists decrease neurotoxicity by inhibiting Ca2+ influx which is of interest for the treatment of acute cerebrovascular insults and chronic neurodegenerative disorders. Currently, there is no surrogate marker for quantification of NMDA-receptor-mediated drug effects, which hampers dose-finding clinical studies. As prolactin and cortisol liberation is in part influenced through NMDA-receptors we investigated whether the elevation of prolactin or cortisol plasma levels is a class effect of NMDA-antagonists and might be an appropriate marker for studying NMDA-antagonistic potency. Fifteen healthy male volunteers participated in this placebo-controlled, randomized, three-way crossover trial. Ketamine (0.5mg/kg), memantine (0.16 mg/kg; i.e., a well tolerated standard dose) or placebo were infused over 60 min. Ketamine increased serum prolactin and cortisol levels (p < 0.001), whereas memantine and placebo did not affect hormone levels. Further studies are needed to define whether higher doses of memantine or other NMDA antagonists can induce hormone release.     

A first approach to compare efficacy and safety of lepirudin and danaparoid in patients with heparin-induced thrombocytopenia (HIT)

Studies using a time‐resolved fluoroimmuno‐assay (DELFIA®) have shown that platelets and plasma are the main compartments of the normal isoform of prion protein (PrP^c) in human blood. The aim of the present study was to monitor PrP^c levels in various fractions of apheresis platelet concentrates (PC) during storage and to assess the association of this release with α granule protein β‐thrombo‐globulin (BTG) and cytoplasmic lactate dehydrogenase (LDH) as cell activation and cell lysis markers, respectively. Six apheresis PC were obtained from volunteer donors using Haemonetics MCS and stored up to 10 days. 7–9 mL samples were aseptically collected from each PC on days 1, 2, 3, 4, 5, 8, and 10 of storage. Platelet poor plasma (PPP) and platelets (P) were prepared and the PPP split into two equal fractions, one of which was centrifuged at 40,000g for 2 h at 4 °C to remove microparticles (MP) [high spun plasma (HSP)]. The results showed that the mean overall levels of PrP^c during storage remained within 15% of day 1 levels. In contrast, the mean levels in P significantly decreased to 46% day 1 levels by day 10 of storage (P < 0·01), while the corresponding levels in plasma significantly rose by up to 329% (P < 0·01). Moreover, although MP‐bound PrP^c was released during storage, it was increasingly superceded by soluble prion protein. PrP^c and BTG release exhibited very similar patterns, both showing a significant rise in PPP and HSP (P < 0·01). In contrast, LDH showed a significant rise in HSP only towards the end of the storage period (P < 0·01). These results indicate that PrP^c is released from platelets during storage of PCs and that this release is probably due mainly to platelet activation and α‐granule release in the first few days of storage. The release of PrP^c is apparently reinforced through cell lysis, and is increasingly comprised of soluble prion proteins, at longer storage periods.     

Referate

Ohne Zusammenfassung     

Heparin lowers plasma levels of activated factor VII

Based on heparin's antithrombin and anti-FXa activity and its in vitro inhibition of activated factor VII (FVIIa) activity, we hypothesized that unfractionated heparin (UFH) may decrease plasma levels of FVIIa in humans. Therefore, 10 healthy young male volunteers received an intravenous UFH infusion over 24 h. Heparin decreased FVIIa levels by 30% (95% CI 14-47%) at 12 h, which was sustained until 24 h. In contrast, neither the substrate pool (i.e. total factor VII) as measured by FVII antigen nor FVII activity were affected by UFH. These results may improve our understanding of the regulation of FVIIa levels and heparin's mode of action.