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16. Livedo racemosa generalisata: an evaluation of thirty-four cases

Author

Lubach, Dietrich, Schwabe, Carmen, Weissenborn, Karin, Hartung, Klaus, Creutzig, Andreas, and Drenk, Franz

Subjects
Autoimmune diseases -- Case studies, Health
Abstract

Generalized livedo racemosa (GLR) is a rare disorder associated with vascular disease and autoimmune illness. It is accentuated by exposure to cold, which leads to a mottling or 'fishnet' appearance of the legs or arms (livedo). Thirty-four patients with GLR were followed-up after a period of seven years from the time they were first identified. Responses of their hands to cold water were measured with a plethysmograph, a device that records size changes in organs as a measure of blood flow changes. Results showed that five patients had died during the seven-year period, and the remaining 29 were quite similar clinically. The livedo was temperature-dependent and often disappeared completely when the patient was in a warm bed. Nineteen patients had suffered a total of 31 cerebral infarctions (blockage or rupture of a blood vessel in the brain, leading to reduced or absent blood flow to the tissue). Six other patients had epilepsy without obvious infarctions, two had peripheral neuropathy (inflammation or degeneration of the peripheral nerves), and one had chorea minor (a disease caused by streptococcus and characterized by writhing movements). Most patients with cerebrovascular symptoms also had psychiatric problems. Three-quarters had high blood pressure, and 35 percent had heart problems. Most also had Raynaud's phenomenon, a syndrome in which blood flow to the extremities lessens and fingers or toes become numb. It appears that cerebrovascular complications develop 10 to 30 years after symptoms of GLR are first noted. (Consumer Summary produced by Reliance Medical Information, Inc.)

Published
1990

25. Untersuchungen zur Bildqualität von Röntgenaufnahmen von Klein- und Heimtieren in der tierärztlichen Praxis

Author

Hartung, Klaus, Universität Leipzig, Boeltzig, Christian, Hartung, Klaus, Universität Leipzig, and Boeltzig, Christian

Abstract

Das Ziel dieser Untersuchung ist es, Aspekte der Strukturqualität (technische Untersuchungs- und Bildqualität), Prozessqualität (Angemessenheit der Indikation) und der Ergebnisqualität (Richtigkeit der Befunderhebungen) von Röntgenaufnahmen aus der tierärztlichen Praxis zu erörtern und häufige Fehlerquellen festzustellen. Dazu werden alle Röntgenaufnahmen von Kleintieren, die im Zeitraum von Anfang Dezember 2003 bis Ende Dezember 2004 als Original in die Klinik für Kleintiere der Universität Leipzig gelangen auf praxisrelevante Merkmale der Struktur-, Prozess- und Ergebnisqualität hin untersucht. Die Ermittlung der Daten erfolgt auf subjektiver Grundlage anhand eines Befundbogens durch Konsensbeurteilung von zwei Unter-suchern. Zur Auswertung gelangen 1259 Röntgenaufnahmen aus 600 verschiedenen Untersuchungen. Diese Aufnahmen stammen zu 86,9 % aus den Bundesländern Sachsen, Sachsen-Anhalt und Thüringen von 216 verschiedenen Tierarztpraxen. 80,3 % der untersuchten Tiere sind Hunde, 18,9 % Katzen. In der Gesamtbeurteilung der Bildqualität erweisen sich 48,7 % der Aufnahmen ohne Bean-standung. 29,2 % zeigen geringfügige Mängel, 16,0 % sind bedingt diagnostisch geeignet und 6,1 % sind unzureichend. 22,1 % der ausgewerteten Aufnahmen sind somit mangelhaft. Sie weisen Defizite in der diagnostischen Eignung auf oder sind hierfür ungeeignet. Die wichtigsten Fehlerquellen der Strukturqualität sind Mängel der Lagerung und Projektion, des Bildkontrastes und der Bildschärfe. Abweichungen der Lagerung und Projektion, meist durch nicht winkelgerechte Lagerung des Patienten im Direktstrahl verursacht, sind mit 11,4 % aller Aufnahmen im Vergleich zu anderen Fehlerquellen relativ selten. Die Auswirkungen auf die diagnostische Eignung sind jedoch oft schwerwiegend: 69,9 % der von Mängeln in der Lagerung betroffenen Aufnahmen zeigen Einschränkungen hinsichtlich der diagnostischen Eignung. 33,3 % aller Aufnahmen weisen Abweichungen des Bildkontrastes auf. Die häufigste Ursache dafür is, The aim of this study is to evaluate aspects of structural quality (technical examination and im-age quality), quality of the process (adequacy of indication) and the outcome (correctness of findings) of radiographs from the veterinary practice and to indentify frequent radiographic er-rors. For this purpose all radiographs of small animals that are received at the Department of Small Animal Medicine of the University of Leipzig between December 1st 2003 and December 31th 2004 as an original are examined for relevant features of structural quality, process quality and outcome. The data collection is done subjectively based on the consensus examination of the radiographs by two independent examiners. The evaluation includes 1259 radiographs from 600 different examinations. 86.9 % of these images come from the federal states of Germany Saxony, Saxony-Anhalt and Thuringia from 216 different veterinary practices. 80.3 % of the examined animals are dogs, 18.9 % are cats. Concerning the over-all evaluation of the image quality, 48.7 % of the radiographs are without restrictions. Minor faults are detected in 29.2 % of the radiographs, 16.0 % are diagnostically compromised and 6.1 % are insufficient. Thus, 22.1 % of the examined radiographs are unsatis-factory. They show either deficits in their diagnostic suitability or are completely useless. The most important sources of errors are faults in positioning of the patient and the following projec-tion, of image contrast and sharpness. Deviations in positioning and projection, mostly caused by a suboptimal angle in the position of the patient in the x-ray, are with 11.4 % of all radiographs in comparison to other errors relatively rare. However the effect on the diagnostic use is severe: 69.9 % of the images with positioning faults show deficits with regard to the diagnostic suitability. Regarding the contrast of the image, 33.3 % of all radiographs display deficits. The most com-mon cause is the use of exhausted developer, f

Published
2010

26. Untersuchungen zur Bildqualität von Röntgenaufnahmen von Klein- und Heimtieren in der tierärztlichen Praxis

Author

Oechtering, Gerhard, Hartung, Klaus, Universität Leipzig, Boeltzig, Christian, Oechtering, Gerhard, Hartung, Klaus, Universität Leipzig, and Boeltzig, Christian

Abstract

Das Ziel dieser Untersuchung ist es, Aspekte der Strukturqualität (technische Untersuchungs- und Bildqualität), Prozessqualität (Angemessenheit der Indikation) und der Ergebnisqualität (Richtigkeit der Befunderhebungen) von Röntgenaufnahmen aus der tierärztlichen Praxis zu erörtern und häufige Fehlerquellen festzustellen. Dazu werden alle Röntgenaufnahmen von Kleintieren, die im Zeitraum von Anfang Dezember 2003 bis Ende Dezember 2004 als Original in die Klinik für Kleintiere der Universität Leipzig gelangen auf praxisrelevante Merkmale der Struktur-, Prozess- und Ergebnisqualität hin untersucht. Die Ermittlung der Daten erfolgt auf subjektiver Grundlage anhand eines Befundbogens durch Konsensbeurteilung von zwei Unter-suchern. Zur Auswertung gelangen 1259 Röntgenaufnahmen aus 600 verschiedenen Untersuchungen. Diese Aufnahmen stammen zu 86,9 % aus den Bundesländern Sachsen, Sachsen-Anhalt und Thüringen von 216 verschiedenen Tierarztpraxen. 80,3 % der untersuchten Tiere sind Hunde, 18,9 % Katzen. In der Gesamtbeurteilung der Bildqualität erweisen sich 48,7 % der Aufnahmen ohne Bean-standung. 29,2 % zeigen geringfügige Mängel, 16,0 % sind bedingt diagnostisch geeignet und 6,1 % sind unzureichend. 22,1 % der ausgewerteten Aufnahmen sind somit mangelhaft. Sie weisen Defizite in der diagnostischen Eignung auf oder sind hierfür ungeeignet. Die wichtigsten Fehlerquellen der Strukturqualität sind Mängel der Lagerung und Projektion, des Bildkontrastes und der Bildschärfe. Abweichungen der Lagerung und Projektion, meist durch nicht winkelgerechte Lagerung des Patienten im Direktstrahl verursacht, sind mit 11,4 % aller Aufnahmen im Vergleich zu anderen Fehlerquellen relativ selten. Die Auswirkungen auf die diagnostische Eignung sind jedoch oft schwerwiegend: 69,9 % der von Mängeln in der Lagerung betroffenen Aufnahmen zeigen Einschränkungen hinsichtlich der diagnostischen Eignung. 33,3 % aller Aufnahmen weisen Abweichungen des Bildkontrastes auf. Die häufigste Ursache dafür is, The aim of this study is to evaluate aspects of structural quality (technical examination and im-age quality), quality of the process (adequacy of indication) and the outcome (correctness of findings) of radiographs from the veterinary practice and to indentify frequent radiographic er-rors. For this purpose all radiographs of small animals that are received at the Department of Small Animal Medicine of the University of Leipzig between December 1st 2003 and December 31th 2004 as an original are examined for relevant features of structural quality, process quality and outcome. The data collection is done subjectively based on the consensus examination of the radiographs by two independent examiners. The evaluation includes 1259 radiographs from 600 different examinations. 86.9 % of these images come from the federal states of Germany Saxony, Saxony-Anhalt and Thuringia from 216 different veterinary practices. 80.3 % of the examined animals are dogs, 18.9 % are cats. Concerning the over-all evaluation of the image quality, 48.7 % of the radiographs are without restrictions. Minor faults are detected in 29.2 % of the radiographs, 16.0 % are diagnostically compromised and 6.1 % are insufficient. Thus, 22.1 % of the examined radiographs are unsatis-factory. They show either deficits in their diagnostic suitability or are completely useless. The most important sources of errors are faults in positioning of the patient and the following projec-tion, of image contrast and sharpness. Deviations in positioning and projection, mostly caused by a suboptimal angle in the position of the patient in the x-ray, are with 11.4 % of all radiographs in comparison to other errors relatively rare. However the effect on the diagnostic use is severe: 69.9 % of the images with positioning faults show deficits with regard to the diagnostic suitability. Regarding the contrast of the image, 33.3 % of all radiographs display deficits. The most com-mon cause is the use of exhausted developer, f

Published
2010

46. Testing for association in SLE families

Author

Seuchter, Susanne A., primary, Knapp, Michael, additional, Hartung, Klaus, additional, Coldewey, Rolf, additional, Kalden, Joachim R., additional, Lakomek, Heinz J., additional, Peter, Hans H., additional, Deicher, Helmuth, additional, Baur, Max P., additional, and Vogler, G. P., additional

Published
1991
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47. Time resolved kinetics of the guinea pig Na–Ca exchanger (NCX1) expressed in Xenopus oocytes: voltage and Ca2+ dependence of pre-steady-state current investigated by photolytic Ca2+concentration jumps.

Author

Haase, Andreas, Wood, Philip G., Pintschovius, Verena, Bamberg, Ernst, and Hartung, Klaus

Subjects
XENOPUS, GUINEA pigs, PHOTOCHEMISTRY, HEART blood-vessels, PATCH-clamp techniques (Electrophysiology)
Abstract

Kinetic properties of the Na–Ca exchanger (guinea pig NCX1) expressed in Xenopus oocytes were investigated by patch clamp techniques and photolytic Ca2+ concentration jumps. Current measured in oocyte membranes expressing NCX1 is almost indistinguishable from current measured in patches derived from cardiac myocytes. In the Ca–Ca exchange mode, a transient inward current is observed, whereas in the Na–Ca exchange mode, current either rises to a plateau, or at higher Ca2+ concentration jumps, an initial transient is followed by a plateau. No comparable current was observed in membrane patches not expressing NCX1, indicating that photolytic Ca2+ concentrations jumps activate Na–Ca exchange current. Electrical currents generated by NCX1 expressed in Xenopus oocytes are about four times larger than those obtained from cardiac myocyte membranes enabling current recording with smaller concentration jumps and/or higher time resolution. The apparent affinity for Ca2+ of nonstationary exchange currents (0.1 mM) is much lower than that of stationary currents (6 μM). Measurement of the Ca2+ dependence of the rising phase provides direct evidence that the association rate constant for Ca2+ is about 5 × 108 M−1 s−1 and voltage independent. In both transport modes, the transient current decays with a voltage independent but Ca2+-dependent rate constant, which is about 9,000 s−1 at saturating Ca2+ concentrations. The voltage independence of this relaxation is maintained for Ca2+ concentrations far below saturation. In the Ca–Ca exchange mode, the amount of charge translocated after a concentration jump is independent of the magnitude of the jump but voltage dependent, increasing at negative voltages. The slope of the charge–voltage relation is independent of the Ca2+ concentration. Major conclusions are: (1) Photolytic Ca2+ concentration jumps generate current related to NCX1. (2) The dissociation constant for Ca2+ at the cytoplasmic transport binding site is about 0.1 mM. (3) The association rate constant of Ca2+ at the cytoplasmic transport sites is high (5 × 10−8 M−1s−1) and voltage independent. (4) The minimal five-state model (voltage independent binding reactions, one voltage independent conformational transition and one very fast voltage dependent conformational transition) used before to describe Ca2+ translocation at saturating Ca2+ concentrations is valid for Ca2+ concentrations far below saturation. [ABSTRACT FROM AUTHOR]

Published
2007
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48. Fluorometric Measurements of Intermolecular Distances between the α and β-Subunits of the Na+/K+~ATPase.

Author

Dempski, Robert E., Hartung, Klaus, Friedrich, Thomas, and Bamberg, Ernst

Subjects
*CELL membranes, *ADENOSINE triphosphatase, *HYDROLYSIS, *XENOPUS laevis, *FLUORIMETRY
Abstract

The Na+/K+-ATPase maintains the physiological Na+ and K+ gradients across the plasma membrane in most animal cells. The functional unit of the ion pump is comprised of two mandatory subunits including the α-subunit, which mediates ATP hydrolysis and ion translocation, as well as the α-subunit, which acts as a chaperone to promote proper membrane insertion and trafficking in the plasma membrane. To examine the conformational dynamics between the α- and β-subunits of the Na+/K+-ATPase during ion transport, we have used fluorescence resonance energy transfer, under voltage clamp conditions on Xenopus laevis oocytes, to differentiate between two models that have been proposed for the relative orientation of the α- and β-subunits. These experiments were performed by measuring the time constant of irreversible donor fluorophore destruction with fluorescein-5-maleimide as the donor fluorophore and in the presence or absence of tetramethylrhodamine- 6-maleimide as the acceptor fluorophore following labeling on the M3-M4 or M5-M6 loop of the α-subunit and the β-subunit. We have also used fluorescence resonance energy transfer to investigate the relative movement between the two subunits as the ion pump shuttles between the two main conformational states (E1 and E2) as described by the Albers-Post scheme. The results from this study have identified a model for the orientation of the β-subunit in relation to the α-subunit and suggest that the α- and β-subunits move toward each other during the E2 to E1 conformational transition. [ABSTRACT FROM AUTHOR]

Published
2006
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49. Activation and inactivation kinetics of a Ca2+-activated Cl- current: photolytic Ca2+ concentration and voltage jump experiments.

Author

Haase, Andreas and Hartung, Klaus

Subjects
*XENOPUS, *PHOTOCHEMISTRY, *PHYSIOLOGY, *ACTION potentials, *ELECTROPHYSIOLOGY
Abstract

The activation kinetics of the endogenous Ca2+-activated Cl− current ( I Cl,Ca) from Xenopus oocytes was investigated in excised “giant” membrane patches with voltage and Ca2+ concentration jumps performed by the photolytic cleavage of the chelator DM-nitrophen. Currents generated by photolytic Ca2+ concentration jumps begin with a lag phase followed by an exponential rising phase. Both phases show little voltage dependence but are Ca2+-dependent. The lag phase decreases from about 10 ms after a small Ca2+ concentration jump (0.1 μM) to less than 1 ms after a saturating concentration jump (55 μM). The rate constant of the rising phase is half-maximal at about 5 μM. At saturating Ca2+ concentrations, the rate constant is 400 to 500 s−1. The Ca2+ dependence of the stationary current can be described by the Hill equation with n=2.3 and K 0.5=0.5 μM. The amplitude of the stationary current decreases after the excision of the membrane patch with t 1/2≈5 min (run-down). The activation kinetics of the current elicited by a Ca2+ concentration jump is not affected by the run-down phenomenon. At low Ca2+ concentration (0.3 μM), voltage jumps induce a slowly activating current with voltage-independent time-course. Activation is preceded by an initial transient of about 1-ms duration. At saturating Ca2+ levels (1 mM), the initial transient decays to a stationary current. The transient can be explained by a voltage-dependent inactivation process. The experimental data reported here can be described by a linear five-state reaction model with two sequential voltage-dependent Ca2+-binding steps, followed by a voltage-independent rate-limiting transition to the open and a voltage-dependent transition to a closed, inactivated state. [ABSTRACT FROM AUTHOR]

Published
2006
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