Tauchunfälle

Notfall + Rettungsmedizin - Tauchunfälle sind vergleichsweise selten und stellen (Erst‑)Helfer vor besondere Herausforderungen. Sie müssen schnell und kompetent behandelt werden, da...     

A novel assay for factor XIII based on cross-linking of synthetic peptides: analysis of different substrates.

A novel assay for factor XIII is described that utilizes exclusively small synthetic peptides as substrates for the cross-linking reaction catalyzed by activated factor XIII (FXIIIa). The acyl donor substrate (selection peptide) is immobilized on a microplate via biotin while the acyl acceptor substrate (detection peptide) is labeled with the fluorochrome Oregon green to allow sensitive detection without the need for secondary enzyme systems for signal amplification. Starting with an amino acid sequence from the fibrin gamma-chain (GQQHHLGGAKQAGDV) as a prototype peptide, the influence of amino acid exchanges were investigated with respect to their impact on the FXIIIa-catalyzed reaction. It was found that FXIIIa readily accepts a broad range of substrate peptides, with a proline neighboring the essential lysine having the most detrimental effect. The assay appears to be valuable for the molecular characterization of factor XIII and may be used for a deeper investigation into the substrate requirements of this final enzyme of wound repair, and eventually also for the characterization of other transglutaminases.     

Wirbelsäulenstabilisierung bei extraduraler Metastasenkrankheit Indikation und Verläufe bei 32 Patienten

Zweiunddrei?ig Patienten mit Metastasenkrankheit der Wirbels?ule, überwiegend von Mammakarzinomen und Plasmozytomen wurden über 41/2 Jahre operativ dekomprimiert und stabilisiert. Unter Einbeziehung von 5 früh Verstorbenen, betr?gt die mittlere überlebenszeit 9,5 Monate. Bei Entlassung der überlebenden aus station?rer Behandlung waren mit einer Ausnahme alle Patienten gehf?hig. In der Regel kamen Verbundosteosynthesen, bevorzugt der ventrale Zugang, zur Anwendung. Die pr?operative Embolisation war ein unverzichtbarer Bestandteil des Managements. Die operative Behandlung der Wirbels?ulenmetastasen ist eine segensreiche Methode, die in das gesamte Behandlungskonzept der bedauernswerten Patienten frühzeitig integriert werden sollte. Hochgradige Paresen oder Paralysen, insbesondere nach fudroyantem Verlauf, nicht kontrollierte Prim?rtumoren und spezielle Tumoren, z. B. das Bronchialkarzinom sowie gastrointestinale Karzinome, sind auch in der eigenen Serie indikatorisch eher kritisch zu sehen.      

Age dependence of the flow velocity in the basal cerebral arteries--a transcranial Doppler ultrasound study

The age dependence of the blood flow velocities of the middle, anterior, and posterior cerebral arteries measured by the transcranial Doppler method is discussed and compared with the velocity values in the internal carotid artery. A number of 535 patients without neurological deficits but with a previous neurological event were examined. Flow velocities decrease in all examined vessels with increasing age. This is in accordance with cerebral blood flow measurements by Xenon inhalation techniques. The reasons of the decrease and its consequences on the vasospasm in patients suffering from subarachnoidal hemorrhage are discussed.     

Circadian rhythm and pulsatility of parathyroid hormone secretion in man

OBJECTIVE: We wished to investigate the circadian rhythm and pulsatility of parathyroid hormone (PTH) secretion in man, as conflicting results have been published. DESIGN AND PATIENTS: To investigate the circadian rhythm during daytime, we sampled (a) peripheral blood at hourly intervals in 12 healthy young men from 0900 h until 1700 h. For observation of pulsatility, we sampled (b) peripheral blood at 1-minute intervals for 1 hour in three healthy men and three healthy women (mean 27.7 years, range 21-56 years) and (c) at 1-minute intervals for 30 minutes in 21 patients with surgically confirmed primary hyperparathyroidism (pHPT). MEASUREMENTS: The serum levels of intact PTH were measured by two-site immunoradiometric assay and special care was taken to reduce intra-assay variability, especially at the normal PTH concentration. In series (a), ionized calcium, total calcium and phosphate were also determined. RESULTS: A circadian rhythm during daytime was found for intact PTH in healthy men and women with a nadir at 0930 h and a peak in the afternoon. Ionized calcium and total calcium (protein-adjusted) decreased and phosphate increased in the afternoon. These changes were all statistically significant (P < 0.02). Pulsatility of PTH: Statistical cluster analysis of the data showed no pulsatility either in healthy persons or in patients with primary hyperparathyroidism. In two healthy women and one healthy man slight changes of longer duration were discovered, but no complete pulses. In five patients with primary hyperparathyroidism, larger differences between the highest and lowest concentrations of intact PTH were found, but no complete pulses. CONCLUSIONS: Our data show a significant circadian rhythm during daytime of intact PTH and only minor changes from minute to minute. The alterations in PTH-levels occurred at longer time intervals in healthy persons. In some patients with primary hyperparathyroidism, decreases of PTH-levels were found. The circadian rhythm of PTH may be due to slight changes in calcium or phosphate concentration.