Erinnerungen an die Bekämpfung der Diphtherie in Posen

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Color Doppler ultrasonography of hand and finger arteries to differentiate primary from secondary forms of Raynaud's phenomenon

OBJECTIVE: Modern ultrasound (US) equipment allows rheumatologists to directly visualize hand and finger arteries. How does US aid in diagnosis of Raynaud's phenomenon (RP)? METHODS: Color Doppler US of the proper and common palmar digital, radial, and ulnar arteries and the superficial palmar arch of both hands was performed in 135 consecutive patients who presented with suspected RP. RESULTS: US was pathologic in 63% of patients with secondary RP, in 6% with primary RP, and in none with pseudo-RP (p < 0.0001). We found 3 types of vascular pathology: Type 1 showed narrowing or chronic occlusion of some proper digital arteries; Type 2 was characterized by the same finding in all proper digital arteries; and Type 3 involved acute occlusions. Type 1 was found in 3 of 53 patients with primary RP and in 19 patients with secondary RP including 5 of 9 patients with anti-centromere positive systemic sclerosis (SSc); Type 2 occurred in 16 patients with SSc, MCTD, and dermatomyositis; and Type 3 was found in 8 patients with antiphospholipid antibody syndrome, thromboangiitis obliterans, vibration trauma, or vasculitis. The ulnar arteries were more commonly affected than the radial arteries. The 2nd radial, 3rd radial, 4th ulnar, and 5th ulnar proper palmar digital arteries were most commonly involved. CONCLUSION: Aiding in differentiating primary versus secondary RP, severe versus less severe disease, and acute versus chronic vascular occlusion, digital artery US depicts the same anatomical structures as angiography, but it is cheaper, faster, and noninvasive.     

Haftung des Zahnarztes für Fremdlabor

Abstrakt 1. Wird ein Fremdlabor vom Zahnarzt mit Reparaturarbeiten beauftragt, so ist es dann nicht Verrichtungsgehilfe des Zahnarztes, wenn es an dem für die Zurechnung erforderlichen Abhängigkeitsverhältnis zwischen Arzt und Labor fehlt.2. Fehlt es an einem Weisungsrecht des Zahnarztes gegenüber dem Labor, so ist eine Haftung für das Labor als Verrichtungsgehilfe selbst dann ausgeschlossen, wenn der Zahnarzt das Labor im eigenen Namen und auf eigene Rechnung beauftragt hat. (Leitsätze des Bearbeiters)     

Postappendectomy fluid collections in children: incidence, nature, and evolution evaluated using US

At the authors' medical center, most patients with postappendectomy fluid collections are treated conservatively. Thirty-two (15%) of 216 children underwent postoperative sonography following appendectomies. In ten patients (31%), a total of 16 fluid collections were found on the initial postoperative sonogram. In the seven patients (70%) whose fluid collections were confined to the pelvis, the condition was treated conservatively and it resolved in 2-9 weeks. In three patients, fluid collections required surgical drainage and proved to be abscesses. In two of the three patients, abscesses were multiple and widely distributed in the abdomen, and the patients were clinically ill. The authors conclude that clinically symptomatic fluid collections develop postoperatively in approximately 5% of children who have undergone appendectomy for acute appendicitis and that the size and course of the fluid collection can be objectively monitored using sonography. Such fluid collections confined to the pelvis ultimately resolve with conservative, nonoperative therapy, although resolution may take up to 2 months.     

A Fluid Dynamic Analysis Using Flow Visualization of the Baylor/NASA Implantable Axial Flow Blood Pump for Design Improvement

Abstract: The Baylor/NASA Axial Blood Flow Pump has been developed for use as an implantable left ventricular assist device (LVAD). The pump is intended as an assist device for either pulmonary or systemic circulatory support for more than 3-months' duration. To date the pump provides acceptable results in terms of thrombus formation and hemolysis (IH of 0.018 g/100 L). A fluid dynamics analysis using flow visualization was performed to investigate the flow fields and to determine areas within the pump that could be improved. These studies focused upon the inflow area in front of the pump. A prototype axial flow pump assembly was constructed to facilitate the flow visualization studies. Particle image tracking velocimetry techniques were used to measure Amberlite particles suspended in a blood analog fluid composed of 63% water and 37% glycerin. This method used a pulsed (612 Hz) laser light to determine flow velocity profiles, shear stress, Reynolds numbers, and stagnant areas within the axial pump. These studies showed that the flow straightener (a vaned assembly in the pump inflow) reduced Reynolds numbers from 4,640 to 2,540 (at 8.5 L/min) and that the flow straightener exacerbates a discontinuity found between it and the impeller. Within the inflow area, a maximum of 80 N/m² shear stress was measured, which is well below published blood damage thresholds. Design variations were investigated resulting in a smoother flow transition between flow straightener and impeller. These variations must be investigated further to establish a correlation with hemolysis and thrombus formation.     

Honorarzahlungspflicht bei Nichterscheinen des Patienten

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