[Processed EEG for personalized dosing of anesthetics during general anesthesia]

Electroencephalogram (EEG)-guided anesthesia is indispensable in modern operating rooms and has become established as the standard form of monitoring. Many anesthesiologists rely on processed EEG indices in the hope of averting anesthesia-related complications, such as intraoperative awareness, postoperative delirium and other cognitive complications in their patients. This educational review aims to provide information on the five most prevalent monitors used to guide depth of sedation during general anesthesia. This article elucidates the principles underpinning the application of these monitors where known, which are generally based on power in various EEG frequency bands and on the burst suppression pattern. Convinced that EEG-guided anesthesia has the potential of benefitting many surgical patients, it is felt that many basic principles and shortcomings of processed EEG indices need to be better understood in the clinical practice. After discussing the different monitors and clinically relevant data from the literature, the article gives a short practical guidance on how to critically interpret processed EEG information and troubleshooting of confounded indices in the context of clinical situations.

Electronuclear Transition into a Spatially Modulated Magnetic State in YbRh_{2}Si_{2}

The nature of the antiferromagnetic order in the heavy fermion metal YbRh_{2}Si_{2}, its quantum criticality, and superconductivity, which appears at low mK temperatures, remain open questions. We report measurements of the heat capacity over the wide temperature range 180  μK-80  mK, using current sensing noise thermometry. In zero magnetic field we observe a remarkably sharp heat capacity anomaly at 1.5 mK, which we identify as an electronuclear transition into a state with spatially modulated electronic magnetic order of maximum amplitude 0.1  μ_{B}. We also report results of measurements in magnetic fields in the range 0 to 70 mT, applied perpendicular to the c axis, which show eventual suppression of this order. These results demonstrate a coexistence of a large moment antiferromagnet with putative superconductivity.

Fetal 4D flow MRI of the great thoracic vessels at 3 Tesla using Doppler-ultrasound gating: a feasibility study

OBJECTIVES

To evaluate the feasibility of Doppler-ultrasound (DUS)-gated 4D flow MRI of the fetal great thoracic vessels at 3T in a clinical setting.

METHODS

Sixteen consecutive fetuses (range 30⁺⁴-38⁺⁵ weeks) with (n = 11) and without (n = 5) cardiovascular anomalies underwent 4D flow MRI of the great thoracic vessels at 3T. Direct fetal cardiac gating was obtained using a MR-compatible DUS device. 4D flow MRI-based visualisation and quantification of four target regions (ascending aorta (AAo), descending aorta (DAo), main pulmonary artery (MPA), and ductus arteriosus (DA)) were performed using dedicated software.

RESULTS

Fetal 4D flow MRI of the great thoracic vessels was successful in 12/16 fetuses (75%) by adopting clinical 4D flow MR protocols in combination with direct fetal cardiac DUS-gating. Four datasets were excluded due to artefacts by fetal movement or maternal breathing. 4D flow MRI-derived time-velocity curves revealed typical arterial blood flow patterns in the aorta. 4D flow quantification was achieved for the pre-defined target regions. Average velocity and flow volume were 21.1 ± 5.2 cm/s and 6.0 ± 3.1 mL/s in the AAo, 24.3 ± 6.7 cm/s and 8.4 ± 3.7 mL/s in the DAo, 21.9 ± 6.4 cm/s and 7.8 ± 4.2 mL/s in the MPA, and 23.4 ± 4.7 cm/s and 5.9 ± 3.6 mL/s in the DA, respectively.

CONCLUSIONS

Combination of DUS-gating of the fetal heart and 4D flow MRI allows comprehensive visualisation and quantification of haemodynamics in the fetal great thoracic vessels. DUS-gated fetal 4D flow MRI may provide a new diagnostic approach for prenatal assessment of blood flow haemodynamics.

KEY POINTS

• Fetal cardiac Doppler-ultrasound (DUS) gating and 4D flow MRI can be successfully combined. • DUS-gated fetal 4D flow MRI allowed visualisation and evaluation of streamline directionality, illustration of blood flow variations, and pulsatile arterial waveforms in the target vessels. • 4D flow MRI-based visualisation and quantification of the fetal great thoracic vessels were successful and flow metrics agreed with echocardiographic reference values.

[The quantitative EEG in electroencephalogram-based brain monitoring during general anesthesia]

The electroencephalogram (EEG) is increasingly being used in the clinical routine of anesthesia in German-speaking countries. In over 90% of patients the frontal EEG changes somewhat predictably in response to administration of the normally used anesthetic agents (propofol and volatile gasses). An adequate depth of anesthesia and appropriate concentrations of anesthetics in the brain generate mostly frontal oscillations between 8 and 12 Hz as well as slow delta waves between 0.5 and 4 Hz. The frontal EEG channel is well-suited for avoidance of insufficient depth of anesthesia and excessive administration of anesthetics. This article explains the clinical interpretation of the most important EEG patterns and the biophysical background. Also discussed are important limitations and pitfalls for the clinical routine, which the anesthetist should know in order to utilize the EEG as an admittedly incomplete but clinically extremely important parameter for the level of consciousness.

[Automatic load-distributing band CPR (AutoPulse™) in prone position, feasible?]

BACKGROUND

Due to SARS-CoV‑2 respiratory failure, prone positioning of patients with respiratory and hemodynamic instability has become a frequent intervention in intensive care units (ICUs), and even in patients undergoing transfer in an ambulance or helicopter. It has become increasingly important how to perform safe and effective CPR in prone position, achieving both an optimal outcome for the patient and optimal protection of staff from infection.

MATERIALS AND METHODS

We conducted feasibility tests to assess the effects of CPR with an automatic load-distributing band (AutoPulse™) in prone position and discussed different aspects of mechanical chest compression (mCPR) in prone position.

RESULTS

In supine position, AutoPulse™ generated a constant pressure depth of 3cm at a frequency of 84/min. In prone position, AutoPulse™ generated a constant pressure depth of 2.6cm at a frequency of 84/min.

CONCLUSION

We found mCPR to be feasible in manikins in both prone and supine positions.

[Resuscitative endovascular balloon occlusion of the aorta : Option for incompressible trunk bleeding?]

Hemorrhage is the single largest cause of avoidable death in trauma patients, whereby in civil emergency medicine in Europe most life-threatening hemorrhages occur in the abdomen and the pelvis. This is one reason why endovascular balloon occlusion of the aorta (EBOA), a procedure especially established in vascular surgery, is increasingly propagated for rapid bleeding control in these patients. This review article provides a comprehensive overview of the technique, indications, contraindications and complications of resuscitative endovascular balloon occlusion of the aorta (REBOA). Additionally, outcomes reported in in the currently available literature are summarized and discussed. From this practical and user-oriented consequences for future successful introduction of REBOA in the field of emergency medicine are deduced.

[Approaches to pre-hospital bleeding management : Current overview on civilian emergency medicine]

Severe bleeding is a typical result of traumatic injuries. Hemorrhage is responsible for almost 50% of deaths within the first 6 h after trauma. Appropriate bleeding control and coagulation therapy depends on an integrated concept of local hemostasis by primary pressure with the hands, compression, and tourniquets accompanied by prevention of hypothermia, acidosis and hypocalcemia. Additionally, permissive hypotension is accepted for suitable patients and tranexamic acid should be administered early. Multiple publications prove that prehospital transfusion of blood products (e. g. red blood cells and plasma) and coagulation factors (e. g. fibrinogen) is feasible and safe, but only required for <5% of polytrauma patients in the civilian setting.

Effects of combined helium pre/post-conditioning on the brain and heart in a rat resuscitation model

BACKGROUND

The noble gas helium induces cardio- and neuroprotection by pre- and post-conditioning. We investigated the effects of helium pre- and post-conditioning on the brain and heart in a rat resuscitation model.

METHODS

After approval by the Animal Care Committee, 96 Wistar rats underwent cardiac arrest for 6 min induced by ventricular fibrillation. Animals received 70% helium and 30% oxygen for 5 min before cardiac arrest and for 30 min after restoration of spontaneous circulation (ROSC). Control animals received 70% nitrogen and 30% oxygen. Hearts and brains were excised after 2, 4 h or 7 days. Neurological degeneration was evaluated using TUNEL and Nissl staining in the hippocampal CA-1 sector. Cognitive function after 7 days was detected with the tape removal test. Molecular targets were measured by infrared western blot. Data are shown as median [Interquartile range].

RESULTS

Helium treatment resulted in significantly less apoptosis (TUNEL positive cells/100 pixel 73.5 [60.3-78.6] vs.78.2 [70.4-92.9] P = 0.023). Changes in Caveolin-3 expression in the membrane fraction and Hexokinase-II in the mitochondrial fraction were observed in the heart. Caveolin-1 expression of treated animals significantly differed from control animals in the membrane fraction of the heart and brain after ROSC.

CONCLUSION

Treatment with helium reduced apoptosis in our resuscitation model. Differential expression levels of Caveolin-1, Caveolin-3 and Hexokinase II in the heart were found after helium pre- and post-conditioning. No beneficial effects were seen on neurofunctional outcome.

BEESCOUT: A model of bee scouting behaviour and a software tool for characterizing nectar/pollen landscapes for BEEHAVE

•

BEESCOUT is a spatially explicit, individual-based model of scouting bees.

•

It determines the detection probabilities of food sources.

•

It can be linked to the honey bee model BEEHAVE to predict colony development.

Social bees are central place foragers collecting floral resources from the surrounding landscape, but little is known about the probability of a scouting bee finding a particular flower patch. We therefore developed a software tool, BEESCOUT, to theoretically examine how bees might explore a landscape and distribute their scouting activities over time and space. An image file can be imported, which is interpreted by the model as a “forage map” with certain colours representing certain crops or habitat types as specified by the user. BEESCOUT calculates the size and location of these potential food sources in that landscape relative to a bee colony. An individual-based model then determines the detection probabilities of the food patches by bees, based on parameter values gathered from the flight patterns of radar-tracked honeybees and bumblebees. Various “search modes” describe hypothetical search strategies for the long-range exploration of scouting bees. The resulting detection probabilities of forage patches can be used as input for the recently developed honeybee model BEEHAVE, to explore realistic scenarios of colony growth and death in response to different stressors. In example simulations, we find that detection probabilities for food sources close to the colony fit empirical data reasonably well. However, for food sources further away no empirical data are available to validate model output. The simulated detection probabilities depend largely on the bees’ search mode, and whether they exchange information about food source locations. Nevertheless, we show that landscape structure and connectivity of food sources can have a strong impact on the results. We believe that BEESCOUT is a valuable tool to better understand how landscape configurations and searching behaviour of bees affect detection probabilities of food sources. It can also guide the collection of relevant data and the design of experiments to close knowledge gaps, and provides a useful extension to the BEEHAVE honeybee model, enabling future users to explore how landscape structure and food availability affect the foraging decisions and patch visitation rates of the bees and, in consequence, to predict colony development and survival.

Landscape and climatic characteristics associated with human alveolar echinococcosis in France, 1982 to 2007

Binary file ES_Abstracts_Final_ECDC.txt matches

Using the genetics of Echinococcus multilocularis to trace the history of expansion from an endemic area

Alveolar echinococcosis, caused by the cestode Echinococcus multilocularis, is the most serious parasitic disease for humans in Europe, with a sylvatic life cycle generally between small rodents and red foxes. General expansion of the range of E. multilocularis has been observed across Europe over the last 15years. In France, a westward spread of the known endemic areas of the parasite was described recently. For genotyping, the microsatellite EmsB was used to trace expansion in five French areas. A total of 22 EmsB profiles were identified, with five similar to those previously described in other parts of Europe. An imbalance of genetic diversity was observed between the five areas which also revealed their interconnection with the presence of common profiles, notably the two main profiles both present in all regions except one in the North. These two findings are similar to those described at the European level, highlighting transmission of the parasite by a mainland-island system. A spatio-temporal scenario of the expansion of E. multilocularis can be proposed with spread from the French historical focus in eastern France to the Lorraine, the Champagne-Ardenne and finally the North, while simultaneously another expansion has occurred from the historical focus into the West. The colonization by the parasite into the West and North areas from the historical focus was probably due to the migration of foxes several decades ago. Recent detection of the parasite in new endemic "départements" may be due to more active research rather than a recent spread of the parasite. Regarding the numerous data obtained by the different EmsB analyses, principally across Europe, centralization of all the profiles described in a public databank appears necessary in order to obtain a precise understanding of transmission of the parasite from one country to another.

Detection of a high-endemic focus of Echinococcus multilocularis in red foxes in southern Denmark, January 2013

Binary file ES_Abstracts_Final_ECDC.txt matches

Measurement of the proton-air cross section at √s=57 TeV with the Pierre Auger Observatory

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)(-36)(+28)(syst)] mb is found.

[Update: studies in intensive care medicine. Results of the last 12 months]

Die Intensivmedizin spielt eine bedeutende Rolle sowohl für den medizinischen als auch den ökonomischen Erfolg eines Krankenhauses. Eine qualitativ hochwertige Intensivmedizin setzt die Kenntnis und die Umsetzung relevanter neuer klinischer Studien voraus. Die vorliegende Arbeit gibt einen Überblick über die wichtigsten intensivmedizinischen Publikationen des Jahres 2010 und der ersten Jahreshälfte von 2011 und ordnet diese im Hinblick auf die jeweilige klinische Relevanz ein. In den Jahren 2010 und 2011 sind zahlreiche randomisierte Studien veröffentlicht worden. Schwerpunkte waren die Therapie des Lungenversagens, die Analgosedierung und die Sepsistherapie.

Measurement of the depth of maximum of extensive air showers above 10{18} eV

We describe the measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) g/cm{2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

[Anesthesiologic procedure for elective aortic surgery]

Aortic aneurysms are frequent in the elderly who often suffer from relevant co-morbidities. In Germany it is estimated that approximately 250,000 patients suffer from an aortic aneurysm. Due to the high risk of cardiac or pulmonary complications operative management poses a challenge to the anesthesiologist. Especially hemodynamic management during aortic cross-clamping requires anesthesiologic know-how and an anticipatory use of vasodilators and catecholamines. Furthermore, the anesthesiologist has to protect renal function. In order to avoid paraplegia due to spinal ischemia cerebrospinal fluid drainage may be necessary in patients with aneurysms of the thoracic aorta. In recent years endovascular repair of aortic aneurysms has been established in addition to conventional open surgery. As a consequence in some patients aortic surgery can be performed under regional or local anesthesia. In special cases thoracic endovascular repair requires a medicinal induction of heart arrest or the reduction of aortic blood flow by overpacing.

Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV

The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.

Model generation by domain refinement and rule reduction

The granularity and interpretability of a fuzzy model are influenced by the method used to construct the rule base. Models obtained by a heuristic assessment of the underlying system are generally highly granular with interpretable rules, while models algorithmically generated from an analysis of training data consist of a large number of rules with small granularity. This paper presents a method for increasing the granularity of rules while satisfying a prescribed precision bound on the training data. The model is generated by a two-stage process. The first step iteratively refines the partitions of the input domains until a rule base is generated that satisfies the precision bound. In this step, the antecedents of the rules are obtained from decomposable partitions of the input domains and the consequents are generated using proximity techniques. A greedy merging algorithm is then applied to increase the granularity of the rules while preserving the precision bound. To enhance the representational capabilities of a rule and reduce the number of rules required, the rules constructed by the merging procedure have multi-dimensional antecedents. A model defined with rules of this form incorporates advantageous features of both clustering and proximity methods for rule generation. Experimental results demonstrate the ability of the algorithm to reduce the number of rules in a fuzzy model with both precise and imprecise training information.

Assessment of use of microsatellite polymorphism analysis for improving spatial distribution tracking of echinococcus multilocularis

Alveolar echinococcosis (AE)--caused by the cestode Echinococcus multilocularis--is a severe zoonotic disease found in temperate and arctic regions of the northern hemisphere. Even though the transmission patterns observed in different geographical areas are heterogeneous, the nuclear and mitochondrial targets usually used for the genotyping of E. multilocularis have shown only a marked genetic homogeneity in this species. We used microsatellite sequences, because of their high typing resolution, to explore the genetic diversity of E. multilocularis. Four microsatellite targets (EmsJ, EmsK, and EmsB, which were designed in our laboratory, and NAK1, selected from the literature) were tested on a panel of 76 E. multilocularis samples (larval and adult stages) obtained from Alaska, Canada, Europe, and Asia. Genetic diversity for each target was assessed by size polymorphism analysis. With the EmsJ and EmsK targets, two alleles were found for each locus, yielding two and three genotypes, respectively, discriminating European isolates from the other groups. With NAK1, five alleles were found, yielding seven genotypes, including those specific to Tibetan and Alaskan isolates. The EmsB target, a tandem repeated multilocus microsatellite, found 17 alleles showing a complex pattern. Hierarchical clustering analyses were performed with the EmsB findings, and 29 genotypes were identified. Due to its higher genetic polymorphism, EmsB exhibited a higher discriminatory power than the other targets. The complex EmsB pattern was able to discriminate isolates on a regional and sectoral level, while avoiding overdistinction. EmsB will be used to assess the putative emergence of E. multilocularis in Europe.

Taxonomic position and geographical distribution of the common sheep G1 and camel G6 strains of Echinococcus granulosus in three African countries

The taxonomic and phylogenetic status of Echinococcus granulosus strains are still controversial and under discussion. In the present study, we investigated the genetic polymorphism of E. granulosus isolates originating from three countries of Africa, including a region of Algeria, where the common G1 sheep and the camel G6 strains coexist sympatrically. Seventy-one hydatid cysts were collected from sheep, cattle, camels, and humans. Two mitochondrial markers (cox1 and nad1) were used for strain identification. Two nuclear markers (actII and hbx2) were used to study the possible occurrence of cross-fertilization. Despite the heterogeneity observed among the G1 isolates, they were all localized within one robust cluster. A second strong cluster was also observed containing all of the G6 isolates. Both strains appeared as two distinct groups, and no cases of interbreeding were found. Thus, the attribution of a species rank can be suggested. We also found the Tasmanian sheep G2 strain for the first time in Africa. Because of the slight variations observed between the common sheep and the Tasmanian sheep strains, further studies should be carried out to elucidate the epidemiological relevance of this genetic discrimination.

EmsB, a tandem repeated multi-loci microsatellite, new tool to investigate the genetic diversity of Echinococcus multilocularis

In order to explore the genetic diversity within Echinococcus multilocularis (E. multilocularis), the cestode responsible for the alveolar echinococcosis (AE) in humans, a microsatellite, composed of (CA) and (GA) repeats and designated EmsB, was isolated and characterized in view of its nature and potential field application. PCR-amplification with specific primers exhibited a high degree of size polymorphism between E. multilocularis and Echinococcus granulosus sheep (G1) and camel (G6) strains. Fluorescent-PCR was subsequently performed on a panel of E. multilocularis isolates to assess intra-species polymorphism level. EmsB provided a multi-peak profile, characterized by tandemly repeated microsatellite sequences in the E. multilocularis genome. This "repetition of repeats" feature provided to EmsB a high discriminatory power in that eight clusters, supported by bootstrap p-values larger than 95%, could be defined among the tested E. multilocularis samples. We were able to differentiate not only the Alaskan from the European samples, but also to detect different European isolate clusters. In total, 25 genotypes were defined within 37 E. multilocularis samples. Despite its complexity, this tandem repeated multi-loci microsatellite possesses the three important features for a molecular marker, i.e. sensitivity, repetitiveness and discriminatory power. It will permit assessing the genetic polymorphism of E. multilocularis and to investigate its spatial distribution in detail.

Genetic typing of Echinococcus granulosus in Romania

In Romania, cystic echinococcosis is endemic and affects, besides humans, various animal species including sheep, cattle, and swine. As yet, no molecular-genetic typing has been carried out to clearly identify the putative strains being transmitted there. Parasite samples (protoscoleces or germinal layers) were collected from infected intermediate hosts and subsequently analyzed by comparing the PCR-amplified DNA sequences of three targets: one nuclear (BG1/3) and two mitochondrial (cox1 and nadI). Three strains were identified with the mitochondrial sequences: (i) the common sheep strain (G1) which circulates between sheep and cattle and is infective for humans, (ii) the Tasmanian sheep strain (G2) infecting sheep and cattle, and (iii) the pig strain (G7) predominantly found in swine. To our knowledge, this is the first report which demonstrates the occurrence of the Tasmanian sheep strain in cattle and the sympatric occurrence of these three strains (G1, G2, and G7) in Europe.

Surface contact measurement of electrical cell uncoupling in the mouse heart during ischemia

Electrical cell uncoupling via gap junction closure is assumed to cause characteristic changes of the passive dielectric spectrum of ischemic heart tissue. In order to find an independent evidence for this assumption, we analysed heart tissue during ischemia, measured the open state of gap junctions by means of dye transfer and correlated this parameter with the time course of the dielectric permittivity. The hearts were pre-ischemically arrested by perfusion with Ringer solution containing 20 mmol/L of potassium (group KCL, n=10). This solution was also used with the addition of two gap junction blockers, either 3 mmol/L heptanol (group HEP, n=4) or 20 micromol/L palmitoleic acid (group PA, n=7). During subsequent ischemia at 21.0+/-0.5 degrees C, we monitored the passive dielectric permittivity spectrum and the spread of dye. After a sigmoidal increase the dielectric permittivity reached an upper plateau at 61+/-22 min of ischemia in KCL, at 45+/-7 min in PA, and already during perfusion at 2+/-1 min in group HEP. At the beginning of ischemia, dye migrated to neighbouring cells in groups KCL and PA but not in HEP. In KCL and PA, the intercellular diffusion of dye stopped after 64+/-26 and 40+/-11 min of ischemia, respectively. Our results suggest that the sigmoidal increase in dielectric permittivity and the reduction of dye diffusion depend on a common mechanism, namely gap junction closure.

Simple sequence repeat map of the sunflower genome

Several independent molecular genetic linkage maps of varying density and completeness have been constructed for cultivated sunflower ( Helianthus annuus L.). Because of the dearth of sequence and probe-specific DNA markers in the public domain, the various genetic maps of sunflower have not been integrated and a single reference map has not emerged. Moreover, comparisons between maps have been confounded by multiple linkage group nomenclatures and the lack of common DNA markers. The goal of the present research was to construct a dense molecular genetic linkage map for sunflower using simple sequence repeat (SSR) markers. First, 879 SSR markers were developed by identifying 1,093 unique SSR sequences in the DNA sequences of 2,033 clones isolated from genomic DNA libraries enriched for (AC)(n) or (AG)(n) and screening 1,000 SSR primer pairs; 579 of the newly developed SSR markers (65.9% of the total) were polymorphic among four elite inbred lines (RHA280, RHA801, PHA and PHB). The genetic map was constructed using 94 RHA280 x RHA801 F(7) recombinant inbred lines (RILs) and 408 polymorphic SSR markers (462 SSR marker loci segregated in the mapping population). Of the latter, 459 coalesced into 17 linkage groups presumably corresponding to the 17 chromosomes in the haploid sunflower genome ( x = 17). The map was 1,368.3-cM long and had a mean density of 3.1 cM per locus. The SSR markers described herein supply a critical mass of DNA markers for constructing genetic maps of sunflower and create the basis for unifying and cross-referencing the multitude of genetic maps developed for wild and cultivated sunflowers.

Interspecific differences in cuticular hydrocarbon profiles of Myrmica ants are sufficiently consistent to explain host specificity by Maculinea (large blue) butterflies

The chemical signatures on the cuticles of five common Myrmica ant species were analysed (49 colonies of M. rubra, M. ruginodis, M. sabuleti, M. scabrinodis and M. schencki), each ant being the specific host of one of the five threatened European species of Maculinea butterfly. The cuticular hydrocarbon profile (based on the relative abundance of each chemical) of each ant species was highly distinctive, even between the morphologically similar species M. sabuleti and M. scabrinodis. There was no significant difference in the chemical profiles of workers and larvae from any colony. Nor was there much pattern in the intraspecific variation: colonies from the same populations were significantly, but only slightly, more similar to each other than to colonies from distant populations. M. rubra showed remarkably little variation between populations sampled widely from northern Russia, Ukraine, Scotland and southern England. The data were compared with published profiles of M. rubra and two North American Myrmica species, and with a quantitative reanalysis of data for Maculinea rebeli caterpillars. We conclude that the hydrocarbon profiles of Myrmica species are sufficiently and consistently different for chemical mimicry to explain the pattern of host specificity recorded for the European Maculinea butterflies. The optimum strategy for chemical mimicry in each of the two life-styles of Maculinea larvae is discussed: we suggest that predatory species might benefit from mimicking the median profile of their model whereas the "cuckoo" species would benefit when variation between siblings encompasses a large range of the variation recorded within a local population of the model species.

Activation and inactivation of cAMP-response element-mediated gene transcription in cardiac myocytes

OBJECTIVE

Chronic beta-adrenergic stimulation of the cAMP-dependent signalling pathway is implicated in functionally relevant expressional changes in congestive heart failure. We studied activation and inactivation of the cardiac gene transcription mediated by the cAMP-response element (CRE) and the CRE-binding protein (CREB) as an important mechanism of a cAMP-dependent gene regulation.

METHODS

We investigated the transcriptional activation by forskolin, an activator of the adenylyl cyclase, in chick embryonic cardiomyocytes transfected with a CRE-controlled luciferase construct in comparison to the phosphorylation and expression of CREB determined on immunoblots.

RESULTS

Forskolin (10 micromol/l; 8 h) increased CRE-mediated transcription and phosphorylation of CREB 13- and 1.5-fold, respectively. The phosphorylation was further elevated in combination with cantharidin, an inhibitor of type 1+2A protein phosphatases. The transcriptional response to forskolin was desensitized by pretreatment with forskolin (1 micromol/l; 24 h) while CREB phosphorylation was increased. In forskolin-pretreated cells, total CREB protein levels were decreased. Cantharidin did not restore the attenuated transcriptional response.

CONCLUSIONS

In cardiomyocytes, there is an activation of the CRE-mediated gene transcription by forskolin that is attenuated after prolonged stimulation, and this attenuation is not dependent from a dephosphorylation of CREB. We suggest that attenuation of the CRE-mediated transcription through chronic stimulation of the cAMP-pathway, e.g. by elevated catecholamines, contributes to the altered expressional regulation in congestive heart failure.

Enhanced protein phosphorylation in hypertensive hypertrophy

OBJECTIVE

Chronic pressure overload in spontaneously hypertensive rats (SHR) is accompanied by heart hypertrophy and signs of heart failure. Since there is growing evidence for a possible pathophysiological role of altered protein phosphorylation in heart hypertrophy and failure, we studied here cardiac regulatory phosphoproteins and the kinases and phosphatases which regulate their phosphorylation state.

METHODS

The experiments were performed in ventricles of SHR (12-13 weeks old) and age-matched normotensive Wistar-Kyoto rats (WKY).

RESULTS

Basal as well as isoproterenol (Iso)-stimulated force of contraction (FOC) was markedly decreased in isolated electrically driven papillary muscles of SHR. Iso (3 micromol/l, 10 min) increased FOC by 0.91+/-0.20 mN in SHR and by 3.88+/-0.52 mN in WKY, respectively. Ca(2+)-uptake by sarcoplasmic reticulum (SR) at low ionized Ca(2+)-concentration was increased in homogenates from SHR. This was not due to altered expression of phospholamban (PLB), SR-Ca(2+)-ATPase and calsequestrin. However, PLB-phosphorylation at threonine-17 (PLB-PT-17) and the activity of Ca(2+)/calmodulin dependent protein kinase (Ca(2+)/Cam-PK) was increased in SHR. In addition, we found an enhanced protein kinase A (PKA)-dependent phosphorylation of the inhibitory subunit of troponin (TnI). In contrast, there was no difference in the activity or expression (protein- and mRNA-level) of protein phosphatases type 1 or type 2A between SHR and WKY.

CONCLUSIONS

It is suggested that increased Ca(2+)/Cam-PK-activity with resulting increase of PLB-PT-17 enhanced SR-Ca(2+)-uptake in SHR and might contribute to the pathophysiological changes in cardiac hypertrophy of SHR.

Functional properties of the rat phosphatase 1alpha promoter

The aim of this study was to investigate the functional properties of the promoter of the protein phosphatase 1alpha catalytic subunit. Luciferase plasmids with different fragments of the rat catalytic subunit of the protein phosphatase 1alpha promoter ranging from -3.7 kbp to -59 bp were transiently transfected into cells by the calcium-phosphate precipitation method. The promoter activity was determined in the absence and presence of inotropic agents which influencing the cAMP-depending pathway. The basal transcriptional activity decreased at fragment -124 bp and shorter fragments. To identify regions of regulatory importance we investigated the cAMP-dependent influence on the transcriptional activity. Stimulation of the complete promoter region with forskolin (1-100 microM) for 6 h led to a concentration-dependent decrease of transcriptional activity. Moreover, regions shorter than 3.7 kbp were inhibited by forskolin (10 microM). Short time stimulation (10 min) with forskolin (10 microM) increased the transcriptional activity of only the 3.7 kbp fragment. The effects were antagonized by Rp-cAMPS, a specific antagonist of protein kinase A, indicating cAMP-dependent effects. The results provide evidence for cAMP-dependent regulation of the protein phosphatase 1alpha promotor.

Role of protein phosphatases in regulation of cardiac inotropy and relaxation

We studied the effects of the protein phosphatase (PP) inhibitor cantharidin (Cant) on time parameters and force of contraction (FOC) in isometrically contracting electrically driven guinea pig papillary muscles. We correlated the mechanical parameters of contractility with phosphorylation of the inhibitory subunit of troponin (TnI-P) and with the site-specific phosphorylation of phospholamban (PLB) at serine-16 (PLB-Ser-16) and threonine-17 (PLB-Thr-17). Cant (after 30 min) started to increase FOC (112 +/- 4% of control, n = 10) and TnI-P and PLB-Thr-17 (120 +/- 5 and 128 +/- 7% of control) without any alteration of relaxation time. Cant (10 microM) started to increase PLB-Ser-16, but the relaxation was shortened at only 100 microM (from 140 +/- 9 to 116 +/- 12 ms, n = 9). Moreover, 100 microM Cant, 3 min after application, started to increase PLB-Thr-17, TnI-P, and FOC. Cant (100 microM) began to increase PLB-Ser-16 after 20 min. This was accompanied by shortening of relaxation time. Differences in protein kinase activation or different substrate specificities of PP may explain the difference in Cant-induced site-specific phosphorylation of PLB in isometrically contracting papillary muscles. Moreover, PLB-Thr-17 may be important for inotropy, whereas PLB-Ser-16 could be a major determinant of relaxation time.