Cellular mechanisms in sympatho‐modulation of the heart

Cardiovascular function relies on complex servo-controlled regulation mechanisms that involve both fast-acting feedback responses and long-lasting adaptations affecting the gene expression. The adrenergic system, with its specific receptor subtypes and intracellular signalling cascades provides the major regulatory system, while the parasympathetic system plays a minor role. At the molecular level, Ca2+ acts as the general signal trigger for the majority of cell activities including contraction, metabolism and growth. During recent years, important new results have emerged allowing an integrated view of how the multifarious Ca2+-signalling mechanisms transmit adrenergic impulses to intracellular target sites. These insights into cellular and molecular mechanisms are pivotal in improving pharmacological control of the sympathetic responses to surgical trauma and perioperative stress. They are examined in detail in this review, with particular emphasis being given to the differences in intracellular signalling between cardiomyocytes and vascular smooth muscle cell

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

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

Sainfoin – New Data on Anthelmintic Effects and Production in Sheep and Goats

Gastrointestinal nematodes (GIN) are one of the most important problems affecting health and therefore performance and welfare in small ruminant husbandry. The control of these parasites in the past strongly relied on the repeated use of anthelmintic drugs. This has led to nematode populations which are resistant to most of the currently available anthelmintics. Furthermore customer’s demands for organic and residue free animal products are increasing. The aforementioned problems have given a strong impetus for the development of new non-chemical strategies to control GIN. Previous research has pointed out the anthelmintic potential of sainfoin (Onobrychis viciifolia) and other tanniferous (CT) feed sources in goats and lambs infected with GIN. A recent Swiss experiment focussed on the use of sainfoin and field bean (Vicia faba, cv. Scirocco) as single CT sources as well as in combination for additional synergic effects, to reduce periparturient GIN egg rise of ewes in late gestation and early lactation. Another experiment with Alpine goats concentrated on the influence of sainfoin on milk performance and cheese quality. The results of these experiments will be presented and discussed in connection with previous knowledge on (i) anthelmintic effects of sainfoin and (ii) the influence of sainfoin administration on performance

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

Draft Genome Sequence of the Principal Etiological Agent of Farmer?s Lung Disease, Saccharopolyspora rectivirgula

Saccharopolyspora rectivirgula is the main cause of farmer's lung disease. The development of recombinant antigens to standardize the serodiagnosis of the disease requires knowledge of the S. rectivirgula genome. We sequenced the genome of an environmental strain, S. rectivirgula DSM 43113. A total of 3,221 proteins were found to be encoded in a short 3.9-Mb genome

Size matters in quantitative radar monitoring of animal migration: estimating monitored volume from wingbeat frequency

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Quantitative radar studies are an important component of studying the movements of birds. Whether a bird, at a certain distance from the radar, is detected or not depends on its size. The volume monitored by the radar is therefore different for birds of different sizes. Consequently, an accurate quantification of bird movements recorded by small-scale radar requires an accurate determination of the monitored volume for the objects in question, although this has tended to be ignored. Here, we demonstrate the importance of sensitivity settings for echo detection on the estimated movement intensities of birds of different sizes. The amount of energy reflected from a bird and detected by the radar receiver (echo power) depends not only on the bird's size and on the distance from the radar antenna, but also on the beam shape and the bird's position within this beam. We propose a method to estimate the size of a bird based on the wingbeat frequency, retrieved from the echo-signal, independent of the absolute echo power. The estimated bird-size allows calculation of size-specific monitored volumes, allowing accurate quantification of movement intensities. We further investigate the importance of applying size-specific monitored volumes to quantify avian movements instead of using echo counts. We also highlight the importance of accounting for size-specific monitored volume of small scale radar systems, and the necessity of reporting technical information on radar parameters. Applying this framework will increase the quality and validity of quantitative radar monitoring.COST – European Cooperation in Science and Technolog