COVID-19 pandemic reduces the negative perception of oral health-related quality of life in adolescents

Quality of Life Research - As people around the world are facing the Covid-19 outbreak, their perception of oral health problems could be changed. This study aimed to evaluate the immediate effects...     

Lokale und systemische Wirkung von Stoffwechselinhibitoren auf die Ödembildung

Ohne Zusammenfassung     

Einfluß von Radiomimetica und Röntgenstrahlen auf die Permeabilität der Blut-Hirnschranke

Zusammenfassung Sinalost, Triäthylenmelamin und Röntgenbestrahlung erhöhen die Permeabilität der Blut-Hirnschranke der Ratte für Evans-Blau nach dosis-abhängiger Latenzzeit.Der Permeabilitätsschaden ist nach letaler Ganzkörperbestrahlung sowie letalen und subletalen Dosen von Sinalost und Triäthylenmelamin um den 3. Tag, nach subletaler Ganzkörperbestrahlung um den 7. Tag maximal. Die Regeneration dauert im Fall der Radiomimetica 10 Tage, nach subletaler Ganzkörperbestrahlung länger.Sinalost wirkt auf das Zentralnervensystem toxischer als Triäthylenmelamin.Die Erhöhung der Permeabilität der Blut-Hirnschranke für Evans-Blau während Ganzkörperbestrahlung mit letaler Dosis ist reversibel und darf im Unterschied zu den übrigen Reaktionen als primäre Strahlenwirkung gelten.Herrn Prof. Dr. O. Schaumann zum 75. Geburtstag gewidmet.     

Altered impedance during pigment aggregation in<Emphasis Type="Italic">Xenopus laevis</Emphasis> melanophores

Melanophores are dark-brown pigment cells located in the skin of amphibia, fish and many invertebrates. The skin colour of these organisms is regulated by the translocation of pigment organelles, and the pigment distribution can be altered by external stimuli. The ability to change colour in response to stimuli makes these cells of interest for biosensing applications. It was investigated whether pigment aggregation in Xenopus laevis melanophores can be detected by impedance measurements performed in transparent microvials. The results show that cell attachment, cell spreading and pigment aggregation all resulted in impedance changes, seen particularly at the highest frequency tested (10 kHz). The mechanisms behind the impedance changes were investigated by the addition of latrunculin or melatonin, both of which cause pigment aggregation. The latrunculin-induced aggregation was associated with cell area decrease and filamentous actin (F-actin) breakdown, processes that can influence the impedance. Lack of F-actin breakdown and an increase in cell area during melatonin-induced aggregation suggest that some other intracellular process also contributes to the impedance decrease seen for melatonin. It was shown that impedance measurements reflect not only cell attachment and cell spreading, but also intracellular events.     

Untersuchungen über die Ausspritzmethode zur Lokalisation der Mikroelektrodenspitze bei Potentialmessungen am proximalen Konvolut der Rattenniere

Summary In measurements of transtubular potential differences of the rat kidney, reported previously, the electrode tip could be localized by ejection of electrode fluid under microscopic observation. In the proximal tubule it was found in contrast to the distal tubule that all potential differences disappeared irreversibly upon fluid ejection. The present study is concerned with the mechanism underlying this effect.The localization of the puncturing electrode was controlled by a coupling pulse technique. Current pulses were injected into the tubular lumen through a first electrode, and the same tubule was punctured subsequently with a second electrode which measured the potential difference. It was found that in most impalements the puncturing electrode would stop within the tubular wall, although from microscopic inspection it appeared to have reached the tubular lumen. Furthermore, when fluid was ejected from the electrode tip, the electrode abruptly penetrated into the tubular lumen. Simultaneously the potential difference recorded hitherto disappeared. This coincidence suggests that the breakdown of the potential difference merely corresponds to the potential step between cellular compartment and tubular lumen and that it is not caused by a transtubular leak.Conclusive evidence against the development of leaks during fluid ejection was derived from microperfusion experiments. During perfusion of the tubular lumen with choline chloride solution proximal tubules develop a transtubular potential difference significantly different from zero (up to 30 mV, lumen positive). Whether the electrode entered the tubular lumen during the impalement immediately, or whether the penetration was only accomplished by fluid ejection, did not affect the magnitude of the positive potential differences recorded. Hence these experiments constitute proof that the method of fluid ejection permits reliable measurements of transtubular potential differences in the proximal tubule. They confirm our finding that under normal free flow conditions no transtubular potential difference exists across the proximal tubular epithelium of the rat kidney.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Asthmaanfälle unter niedrigdosierter Heparinprophylaxe bei einem Mann mit Schenkelhalsfraktur und Aortenaneurysma

Summary Hypersensitivity reactions to heparin preparations with a wide spectrum of clinical manifestations have been reported frequently in the past, but are a rarity now. A 88 year old man was admitted for physical therapy of a collum femoris fracture. Treatment with a diuretic, Reserpine and Verapamil was continued. Chest x-ray revealed a large thoracic aortic aneurysm. From the 12th to the 18th day of low dose heparin prophylaxis with calcium heparin, 7500 U twice daily, at least eight attacks of asthma or cyanosis were observed, starting about two hours after heparin injection. The last attack began suddenly with wheezing, tachypnoea and cough and was associated with apprehension, a sudden blood pressure increase and severe cyanosis. Ventilation improved with oxygen and a ₂-stimulator, but hypertension and cyanosis lasted for three hours. After discontinuation of heparin no further attacks occurred. Causes other then heparin could not be found. Despite the use of porcine mucosa heparin, avoidance of preservatives and use of low doses a hypersensitivity reaction occurred in our case. The delayed onset after preceeding subcutaneous application as well as difficulties in separating the reaction from complications of underlying disease may delay heparin discontinuation.

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Abkünzungen BWS Brustwirbelsäule - p.a. posterior-anterior     

A GPS logger and software for analysis of homing in pigeons and small mammals

A detailed analysis of homing in pigeons and small mammals has remained difficult because the paths of the animals could not be reconstructed precisely. Here, we describe a lightweight global position system (GPS) data logger (35 g including battery and casing; 40 x 68 x 18 mm) that records the flight of pigeons and the path of dogs with an accuracy of +/-12 m. With one battery, the logger runs in continuous mode (1 fix/s) for 3.5 h and in power-saving mode (1 fix/5 s) for about 16 h, and stores a maximum of 100,000 data points that are downloaded to a PC. A module of our public domain software WINTRACK permits a detailed numerical and graphical analysis of path geometry, phases of resting and moving, and path similarity. The device can be adapted to different species provided that satellite signals can be received reliably and that the loggers can be recovered. We expect it to be useful for testing hypotheses about pigeon homing, assessing natural spatial behavior and orientation of many species, and anticipate further miniaturization.     

CNS-induced natriuresis, neurohypophyseal peptides and renal dopamine and noradrenaline excretion in prehypertensive salt-sensitive Dahl rats

To identify defects in the salt-sensitive Dahl rat (Dahl-S), the natriuretic, catecholaminergic and pressor responses to 60-min elevation of the cerebroventricular sodium concentration (CNS-induced natriuresis) were compared between prehypertensive salt-sensitive Dahl-S and salt-resistant Dahl rats (Dahl-R). The plasma concentrations of the rat natriuretic hormone oxytocin, which has implications for the development of hypertension, and vasopressin (AVP) were also measured. Basal sodium and catecholamine excretion and mean arterial blood pressure (MAP) were similar in both strains. Sodium excretion during CNS stimulation increased more than 15-fold in Dahl-R but only 10-fold in Dahl-S. Dopamine excretion increased only transiently and similarly in both strains. Noradrenaline excretion and response to CNS stimulation were similar, suggesting a comparable sympathetic nervous activity between the strains. MAP increased comparably in Dahl-R and Dahl-S. Plasma AVP concentration was similar in both strains while plasma oxytocin concentration after CNS stimulation was more than 2-fold higher in Dahl-S than in Dahl-R. In conclusion, the prehypertensive Dahl-S has an attenuated natriuretic response to elevations of the cerebroventricular fluid sodium concentration and a higher plasma level of the natriuretic hormone oxytocin. Dopamine is not a mediator of CNS-induced natriuresis in neither strain. The attenuated natriuretic response may partly explain the salt-sensitivity in Dahl-S, and the higher plasma oxytocin value may either represent an effort to compensate for the deficient natriuretic response or reflect a primary defect in this system. Due to the known involvement of oxytocin in central MAP regulation in some hypertensive animal models, the findings warrant further investigation.