Hyperoxia in extreme hemodilution

Intraoperative surgical blood loss is initially replaced by infusion of red cell-free, cristalloidal or colloidal solutions. When normovolemia is maintained the ensuing dilutional anemia is compensated by an increase of cardiac output and of arterial oxygen extraction. In the ideal case, a surgical blood loss can entirely be `bridged' without transfusion by intraciperative normovolemic hemodilution. However major blood loss results in extreme hemodilution and the transfusion of red blood cells may finally become necessary to increase arterial oxygen content and to preserve tissue oxygenation. When transfusion has to be started before surgical control of bleeding has been achieved, parts of the red blood cells transfused will get lost, thereby increasing intraoperative transfusion needs. Beside red blood cell transfusion, arterial oxygen content can be rapidly increased by ventilating the patient with 100% oxygen (hyperoxic ventilation), thus enhancing the amount of physically dissolved oxygen in plasma (hyperoxia). In experimental and clinical studies hyperoxic ventilation has emerged as a simple, safe and effective intervention to enlarge the margin of safety for hemodynamic compensation and tissue oxygenation in hemodiluted subjects experiencing major bleeding. The hyperoxia-associated microcirculatory dysregulation and impaired tissue oxygenation known to take place in the presence of a physiologic hemoglobin concentration are not encountered in hemodiluted subjects. Hyperoxic hemodilution i.e. the combination of intraoperative extreme hemodilution and hyperoxic ventilation may therefore be considered a cost-effective, safe and efficient supplement to reduce allogeneic transfusion during surgical interventions associated with high blood losses. The vast majority of the experimental and clinical investigations this new concept is based on was initiated and performed under the guidance of Prof. Konrad Messmer. Copyright (C) 2002 S. Karger AG, Basel

Diaspirin cross-linked hemoglobin fails to improve left ventricular diastolic function after fluid resuscitation from hemorrhagic shock

In severe hemorrhagic shock, left ventricular (LV) diastolic dysfunction is an early sign of cardiac failure due to compromised myocardial oxygenation. Immediate fluid replacement or, in particular, administration of a hemoglobin-based oxygen carrier (diaspirin cross-linked hemoglobin; DCLHb) improves myocardial oxygenation; therefore, positive effects on LV diastolic function could be expected. The effects of fluid resuscitation from severe hemorrhagic shock with DCLHb were investigated in 20 anesthetized domestic pigs. After generation of a critical left anterior descending coronary artery stenosis (narrowing of the artery until disappearance of reactive hyperemia after a 10-second complete vessel occlusion), hemorrhagic shock (mean arterial blood pressure 45 mm Hg) was induced within 15 min by controlled blood withdrawal and maintained for 60 min. Fluid resuscitation consisted of replacement of the plasma volume withdrawn during hemorrhage by infusion of either 10% DCLHb (DCLHb group, n = 10) or 8% human serum albumin (HSA) oncotically matched to DCLHb (HSA group, n = 10). After completion of resuscitation, an observation period of 60 min elapsed. Measurements of central hemodynamics, myocardial oxygenation, and LV Stolic function were performed at baseline, after induction of critical coronary artery stenosis, after 60 min hemorrhagic shock, immediately after resuscitation, and 60 min later. While 5 out of 10 animals treated with died within the first 20 min after fluid resuscitation from acute LV pump failure, all DCLHb-treated animals survived until the end of the protocol (p < 0.05). Despite superior myocardial oxygenation due to augmentation of the arterial O-2 content as well as of coronary perfusion pressure, no beneficial effects on LV diastolic function were observed after infusion of DCLHb. Peak velocity Of LV pressure decrease (dp/dt(min)) did not reveal significant differences between the two groups. Immediately after completion of fluid resuscitation with DCLHb, the time constant of LV diastolic relaxation (tau) was prolonged when compared with HSA-treated animals (p < 0.05), indicating retardation of early LV diastolic relaxation. Our data suggest that DCLHb fails to improve LV diastolic function after fluid resuscitation from severe hemorrhagic shock. However, positive effects on myocardial perfusion. and oxygenation result in a significant reduction of the mortality of severe hemorrhagic shock. Copyright (C) 2001 S.Karger AG, Basel

Auswirkungen von Schnitt-und Weidenutzung auf die Ertragsbildung und den Stickstoffgehalt verschiedener Futterleguminosen.

The objective of this study was to compare the agronomic performance of different forage legume species submitted to different management systems, i.e. grazing, silage-cut and simulated grazing to find alternatives for white clover. The experiment was established in 2003 and 2004 as binary swards with perennial ryegrass (Lolium perenne L.) as the companion grass with three replicates in two different sites on the experimental station “Lindhof” of the University of Kiel. Legume species were arranged within each management system as completely randomised blocks. Results of agro-nomic performance of the first production years in 2004 and 2005 (DM-yield, botanical composition, N-yield, N-content) are presented for white clover swards (Trifolium repens L.), red clover swards (Trifolium pratense L.), lucerne swards (grazing type, Medicago sativa L.) and birdsfoot trefoil swards (Lotus corniculatus L.). Considering both years the birdsfoot trefoil/grass-swards were the only ones which produced significantly less DM-yield (736 g DM m² a-1) under simulated grazing than the white clover/grass-swards (805 g DM m2 a-1). While under grazing all legume/grass-swards produced a significant lower DM-yield compared to the white clover/grass-swards, no significant differences can be found under the silage-cut system. Considering the N-yield, birdsfoot trefoil/grass-swards were the only legume/grass-swards which pro-duced a significant lower N-yield under the 5-cut system (14.1 g N m² a-1) as well as under grazing (15.7 g N m² a-1) compared to the white clover/grass-swards (26 g N m² a-1 and 21.9 g N m² a-1 respectively). Considering the botanical composition of the different legume/grass-swards all legume species had a significant higher propor-tion of total DM-yield under cutting compared to white clover in 2004. Comparisons between systems showed that beside the white clover/grass-swards all legume/grass-swards had a significant lower legume proportion under grazing in comparison to the cutting systems. Because of the comparable agronomic performance of the red clo-ver/grass-swards and lucerne/grass-swards, both legume species could be used as alternatives for white clover under cutting, while the birdsfoot trefoil/grass-swards should be considered carefully because of their low agronomic performance. Whereas white clover showed the highest performance under the grazing system, none of the different legume species present an alternative for white clover

Chaos - No randomness in cardiac physiology

Struktur telinga manusia memiliki ciri yang stabil dan dapat diandalkan dibandingkan dengan wajah, karena struktur telinga tidak mengalami Perubahan secara proporsional pada peningkatan usia. Penelitian ini menggunakan ekstraksi ciri Zernike moment invariants (ZMI) untuk menentukan karakteristik daun telinga, sedangkan pengenalan telinga menggunakan Jaringan Syaraf Propagasi Balik (JSPB). Hasil eksperimen menunjukkan akurasi pengenalan telinga mencapai sebesar 96,66%

Searching the ideal inhaled vasodilator: From nitric oxide to prostacyclin

Today, the technique to directly administer vasodilators via the airway to treat pulmonary hypertension and to improve pulmonary gas exchange is widely accepted among clinicians. The flood of scientific work focussing on this new therapeutic concept had been initiated by a fundamental new observation by Pepke-Zaba {[}1] and Frostell in 1991 {[}2]: Both scientists reported, that inhalation of exogenous nitric oxide (NO) gas selectively dilates pulmonary vessels without a concomittant systemic vasodilation. No more than another decade ago NO was identified as an important endogenous vasodilator {[}3] while having merely been regarded an environmental pollutant before that time. Although inhaled NO proved to be efficacious, alternatives were sought-after due to NO's potential side-effects. In search for the ideal inhaled vasodilator another group of endogenous mediators - the prostanoids - came into the focus of interest. The evidence for safety and efficacy of inhaled prostanoids is - among a lot of other valuable work - based on a series of experimental and clinical investigations that have been performed or designed at the Institute for Surgical Research under the guidance and mentorship of Prof. Dr. med. Dr. h.c. mult. K. Messmer {[}4-19]. In the following, the current and newly emerging clinical applications of inhaled prostanoids and the experimental data which they are based on, will be reviewed. Copyright (C) 2002 S. Karger AG, Basel

Emerging concepts in biomarker discovery; The US-Japan workshop on immunological molecular markers in oncology

Supported by the Office of International Affairs, National Cancer Institute (NCI), the "US-Japan Workshop on Immunological Biomarkers in Oncology" was held in March 2009. The workshop was related to a task force launched by the International Society for the Biological Therapy of Cancer (iSBTc) and the United States Food and Drug Administration (FDA) to identify strategies for biomarker discovery and validation in the field of biotherapy. The effort will culminate on October 28th 2009 in the "iSBTc-FDA-NCI Workshop on Prognostic and Predictive Immunologic Biomarkers in Cancer", which will be held in Washington DC in association with the Annual Meeting. The purposes of the US-Japan workshop were a) to discuss novel approaches to enhance the discovery of predictive and/or prognostic markers in cancer immunotherapy; b) to define the state of the science in biomarker discovery and validation. The participation of Japanese and US scientists provided the opportunity to identify shared or discordant themes across the distinct immune genetic background and the diverse prevalence of disease between the two Nations