Leukonychia: What Can White Nails Tell Us?

Changes in nail color can provide important clues of underlying systemic and skin disease. In particular, white discoloration (leukonychia) has a high prevalence with a wide array of potential relevant causes, from simple manicure habits to life-threatening liver or kidney failure. Therefore, a reliable assessment of the patient with leukonychia is essential. In the past, two classifications for leukonychia have been presented. The morphological classifies the nail according to the distribution of the white lines: total, partial, transversal, and longitudinal leukonychia. Mees' and Muehrcke's lines are examples of transversal leukonychia, while Terry's and Lindsay's nails are examples of total and partial leukonychia. The anatomical classifies according to the structure responsible for the white color: the nail plate in true leukonychia, the nail bed in apparent leukonychia, and the surface only in pseudoleukonychia. In this review, both morphological and anatomical features have been combined in an algorithm that enables clinicians to approach leukonychia efficiently and effectively

Perioperative Strategien zur Regulierung des Sympathikotonus

Zusammenfassung: Obwohl für verschiedene therapeutische Konzepte zur Verminderung der kardialen perioperativen Morbidität und Mortalität zunehmend Evidenz vorliegt, bleibt die tatsächliche Umsetzung solcher Konzepte im klinischen Alltag oft aus. Zwar ist einem großen Teil der klinisch tätigen Ärzte die wachsende Literatur bekannt; dieses Wissen wird aber nur in einem Teil der Fälle angewendet, selbst wenn allgemein akzeptierte Indikationen bestehen. Die vorliegende Übersichtsarbeit hat deshalb zum Ziel, die Gründe für die mangelnde Umsetzung aufzuzeigen und nochmals die wesentlichen Grundlagen sowie die klinische Bedeutung einzelner Strategien einschließlich des α2-Agonismus, der β-adrenergen Blockade und der Regionalanästhesien zusammenzufassen. Dies insbesondere im Hinblick auf die klinische Anwendung dieser Konzepte in einem allgemeinanästhesiologischen Umfeld. Zudem wird ein Ausblick in die auf "gene profiling" basierende individualisierte Pharmakotherapie der perioperativen Medizin von morgen gegebe

Rheology of Ring Polymer Melts: From Linear Contaminants to Ring/Linear Blends

Ring polymers remain a major challenge to our current understanding of polymer dynamics. Experimental results are difficult to interpret because of the uncertainty in the purity and dispersity of the sample. Using both equilibrium and non-equilibrium molecular dynamics simulations we have systematically investigated the structure, dynamics and rheology of perfectly controlled ring/linear polymer blends with chains of such length and flexibility that the number of entanglements is up to about 14 per chain, which is comparable to experimental systems examined in the literature. The smallest concentration at which linear contaminants increase the zero-shear viscosity of a ring polymer melt of these chain lengths by 10% is approximately one-fifth of their overlap concentration. When the two architectures are present in equal amounts the viscosity of the blend is approximately twice as large as that of the pure linear melt. At this concentration the diffusion coefficient of the rings is found to decrease dramatically, while the static and dynamic properties of the linear polymers are mostly unaffected. Our results are supported by a primitive path analysis.Comment: 5 pages, 4 figures, accepted by PR

Anaesthetics and cardiac preconditioning. Part I. Signalling and cytoprotective mechanisms

Cardiac preconditioning represents the most potent and consistently reproducible method of rescuing heart tissue from undergoing irreversible ischaemic damage. Major milestones regarding the elucidation of this phenomenon have been passed in the last two decades. The signalling and amplification cascades from the preconditioning stimulus, be it ischaemic or pharmacological, to the putative end‐effectors, including the mechanisms involved in cellular protection, are discussed in this review. Volatile anaesthetics and opioids effectively elicit pharmacological preconditioning. Anaesthetic‐induced preconditioning and ischaemic preconditioning share many fundamental steps, including activation of G‐protein‐coupled receptors, multiple protein kinases and ATP‐sensitive potassium channels (KATP channels). Volatile anaesthetics prime the activation of the sarcolemmal and mitochondrial KATP channels, the putative end‐effectors of preconditioning, by stimulation of adenosine receptors and subsequent activation of protein kinase C (PKC) and by increased formation of nitric oxide and free oxygen radicals. In the case of desflurane, stimulation of α‐ and β‐adrenergic receptors may also be of importance. Similarly, opioids activate δ‐ and κ‐opioid receptors, and this also leads to PKC activation. Activated PKC acts as an amplifier of the preconditioning stimulus and stabilizes, by phosphorylation, the open state of the mitochondrial KATP channel (the main end‐effector in anaesthetic preconditioning) and the sarcolemmal KATP channel. The opening of KATP channels ultimately elicits cytoprotection by decreasing cytosolic and mitochondrial Ca2+ overload. Br J Anaesth 2003; 91: 551-6

Ueber bilineare Formen und deren geometrische Anwendung

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Anaesthetics and cardiac preconditioning. Part II. Clinical implications

There is compelling evidence that preconditioning occurs in humans. Experimental studies with potential clinical implications as well as clinical studies evaluating ischaemic, pharmacological and anaesthetic cardiac preconditioning in the perioperative setting are reviewed. These studies reveal promising results. However, there are conflicting reports on the efficacy of preconditioning in the diseased and aged myocardium. In addition, many anaesthetics and a significant number of perioperatively administered drugs affect the activity of cardiac sarcolemmal and mitochondrial KATP channels, the end‐effectors of cardiac preconditioning, and thereby markedly modulate preconditioning effects in myocardial tissue. Although these modulatory effects on KATP channels have been investigated almost exclusively in laboratory investigations, they may have potential implications in clinical medicine. Important questions regarding the clinical utility and applicability of perioperative cardiac preconditioning remain unresolved and need more experimental work and randomized controlled clinical trials. Br J Anaesth 2003; 91: 566-7

On the theory of Gordan-Noether on homogeneous forms with zero Hessian (Improved version)

We give a detailed proof for Gordan-Noether's results in "Ueber die algebraischen Formen, deren Hesse'sche Determinante identisch verschwindet" published in 1876 in Mathematische Annahlen. C. Lossen has written a paper in a similar direction as the present paper, but did not provide a proof for every result. In our paper, every result is proved. Furthermore, our paper is independent of Lossen's paper and includes a considerable number of new observations. An earlier version of this paper has been printed in Proceedings of the School of Science of Tokai University, Vol.49, Mar. 2014. In this version, a serious error has been corrected and some new results have been added

Teilvorhaben: "Plasmachemische Oberflächenbehandlung von Grafitfasern in einer Niederdruck-Wirbelschicht" des Verbundprojekts: "Grundlegende Untersuchungen zur plasmachemischen Behandlung von Grafitfasern für innovative Einsatzpotentiale" : Schlussbericht

[no abstract available