Cardiovascular drugs attenuated myocardial resistance against ischaemia-induced and reperfusion-induced injury in a rat model of repetitive occlusion

We investigated the impact of cardioprotective drugs on ST-elevation, arrhythmias and infarct size in a rat model of repetitive coronary artery occlusion

Leukocyte telomere length and mitochondrial DNA copy number associate with endothelial function in aging-related cardiovascular disease

BackgroundWe investigated the association between leukocyte telomere length, mitochondrial DNA copy number, and endothelial function in patients with aging-related cardiovascular disease (CVD).MethodsIn total 430 patients with CVD and healthy persons were enrolled in the current study. Peripheral blood was drawn by routine venipuncture procedure. Plasma and peripheral blood mononuclear cells (PBMCs) were collected. Cell-free genomic DNA (cfDNA) and leukocytic genomic DNA (leuDNA) were extracted from plasma and PBMCs, respectively. Relative telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN) were analyzed using quantitative polymerase chain reaction. Endothelial function was evaluated by measuring flow-mediated dilation (FMD). The correlation between TL of cfDNA (cf-TL), mtDNA-CN of cfDNA (cf-mtDNA), TL of leuDNA (leu-TL), mtDNA-CN of leuDNA (leu-mtDNA), age, and FMD were analyzed based on Spearman's rank correlation. The association between cf-TL, cf-mtDNA, leu-TL, leu-mtDNA, age, gender, and FMD were explored using multiple linear regression analysis.Resultscf-TL positively correlated with cf-mtDNA (r = 0.1834, P = 0.0273), and leu-TL positively correlated with leu-mtDNA (r = 0.1244, P = 0.0109). In addition, both leu-TL (r = 0.1489, P = 0.0022) and leu-mtDNA (r = 0.1929, P < 0.0001) positively correlated with FMD. In a multiple linear regression analysis model, both leu-TL (β = 0.229, P = 0.002) and leu-mtDNA (β = 0.198, P = 0.008) were positively associated with FMD. In contrast, age was inversely associated with FMD (β = −0.426, P < 0.0001).ConclusionTL positively correlates mtDNA-CN in both cfDNA and leuDNA. leu-TL and leu-mtDNA can be regarded as novel biomarkers of endothelial dysfunction

Cyclodextrin modulation of gallic acid in vitro antibacterial activity

The substitution of large spectrum antibiotics for natural bioactive molecules (especially polyphenolics) for the treatment of wound infections has come into prominence in the pharmaceutical industry. However, the use of such molecules depends on their stability during environmental stress and on their ability to reach the action site without losing biological properties. The application of cyclodextrins as a vehicle for polyphenolics protection has been documented and appears to enhance the properties of bioactive molecules. Therefore, the encapsulation of gallic acid, an antibacterial agent with low stability, by -cyclodextrin, (2-hydroxy) propyl--cyclodextrin and methyl--cyclodextrin, was investigated. Encapsulation by -cyclodextrin was confirmed for pH 3 and 5, with similar stability parameters. The (2-hydroxy) propyl--cyclodextrin and methyl--cyclodextrin interactions with gallic acid were only confirmed at pH 3. Among the three cyclodextrins, better gallic acid encapsulation were observed for (2-hydroxy) propyl--cyclodextrin, followed by -cyclodextrin and methyl--cyclodextrin. The effect of cyclodextrin encapsulation on the gallic acid antibacterial activity was also analysed. The antibacterial activity of the inclusion complexes was investigated here for the first time. According to the results, encapsulation of gallic acid by (2-hydroxy) propyl--cyclodextrin seems to be a viable option for the treatment of skin and soft tissue infections, since this inclusion complex has good stability and antibacterial activity.The authors are grateful for the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the Project "BioHealth-Biotechnology and Bioengineering approaches to improve health quality", Ref. NORTE-07-0124-FEDER-000027, co-funded by the "Programa Operacional Regional do Norte" (ON.2-O Novo Norte), QREN, FEDER. The authors also acknowledge the project "Consolidating Research Expertise and Resources on Cellular and Molecular Biotechnology at CEB/IBB", Ref. FCOMP-01-0124-FEDER-027462. This work is, also, funded by FEDER funds through the Operational Programme for Competitiveness Factors-COMPETE and National Funds through FCT-Foundation for Science and Technology under the project PEst-C/CTM/UI0264/2011. Additionally, the authors would like to thank the FCT for the grant for E. Pinho (SFRH/BD/62665/2009)

Detection of Prion Protein Particles in Blood Plasma of Scrapie Infected Sheep

Prion diseases are transmissible neurodegenerative diseases affecting humans and animals. The agent of the disease is the prion consisting mainly, if not solely, of a misfolded and aggregated isoform of the host-encoded prion protein (PrP). Transmission of prions can occur naturally but also accidentally, e.g. by blood transfusion, which has raised serious concerns about blood product safety and emphasized the need for a reliable diagnostic test. In this report we present a method based on surface-FIDA (fluorescence intensity distribution analysis), that exploits the high state of molecular aggregation of PrP as an unequivocal diagnostic marker of the disease, and show that it can detect infection in blood. To prepare PrP aggregates from blood plasma we introduced a detergent and lipase treatment to separate PrP from blood lipophilic components. Prion protein aggregates were subsequently precipitated by phosphotungstic acid, immobilized on a glass surface by covalently bound capture antibodies, and finally labeled with fluorescent antibody probes. Individual PrP aggregates were visualized by laser scanning microscopy where signal intensity was proportional to aggregate size. After signal processing to remove the background from low fluorescence particles, fluorescence intensities of all remaining PrP particles were summed. We detected PrP aggregates in plasma samples from six out of ten scrapie-positive sheep with no false positives from uninfected sheep. Applying simultaneous intensity and size discrimination, ten out of ten samples from scrapie sheep could be differentiated from uninfected sheep. The implications for ante mortem diagnosis of prion diseases are discussed

Species-speciWc defense strategies of vegetative versus reproductive blades of the PaciWc kelps Lessonia nigrescens and Macrocystis integrifolia

Chemical defense is assumed to be costly and therefore algae should allocate defense investments in a way to reduce costs and optimize their overall fitness. Thus, lifetime expectation of particular tissues and their contribution to the fitness of the alga may affect defense allocation. Two brown algae common to the SE Pacific coasts, Lessonia nigrescens Bory and Macrocystis integrifolia Bory, feature important ontogenetic differences in the development of reproductive structures; in L. nigrescens blade tissues pass from a vegetative stage to a reproductive stage, while in M. integrifolia reproductive and vegetative functions are spatially separated on different blades. We hypothesized that vegetative blades of L. nigrescens with important future functions are more (or equally) defended than reproductive blades, whereas in M. integrifolia defense should be mainly allocated to reproductive blades (sporophylls), which are considered to make a higher contribution to fitness. Herein, within-plant variation in susceptibility of reproductive and vegetative tissues to herbivory and in allocation of phlorotannins (phenolics) and N-compounds was compared. The results show that phlorotannin and N-concentrations were higher in reproductive blade tissues for both investigated algae. However, preferences by amphipod grazers (Parhyalella penai) for either tissue type differed between the two algal species. Fresh reproductive tissue of L. nigrescens was more consumed than vegetative tissue, while the reverse was found in M. integrifolia, thus confirming the original hypothesis. This suggests that future fitness function might indeed be a useful predictor of anti-herbivore defense in large, perennial kelps. Results from feeding assays with artificial pellets that were made with air-dried material and extract-treated Ulva powder indicated that defenses in live algae are probably not based on chemicals that can be extracted or remain intact after air-drying and grinding up algal tissues. Instead, anti-herbivore defense against amphipod mesograzers seems to depend on structural traits of living algae

The Arabidopsis leucine-rich repeat receptor kinase MIK2/LRR-KISS connects cell wall integrity sensing, root growth and response to abiotic and biotic stresses

Plants actively perceive and respond to perturbations in their cell walls which arise during growth, biotic and abiotic stresses. However, few components involved in plant cell wall integrity sensing have been described to date. Using a reverse-genetic approach, we identified the Arabidopsis thaliana leucine-rich repeat receptor kinase MIK2 as an important regulator of cell wall damage responses triggered upon cellulose biosynthesis inhibition. Indeed, loss-of-function mik2 alleles are strongly affected in immune marker gene expression, jasmonic acid production and lignin deposition. MIK2 has both overlapping and distinct functions with THE1, a malectin-like receptor kinase previously proposed as cell wall integrity sensor. In addition, mik2 mutant plants exhibit enhanced leftward root skewing when grown on vertical plates. Notably, natural variation in MIK2 (also named LRR-KISS) has been correlated recently to mild salt stress tolerance, which we could confirm using our insertional alleles. Strikingly, both the increased root skewing and salt stress sensitivity phenotypes observed in the mik2 mutant are dependent on THE1. Finally, we found that MIK2 is required for resistance to the fungal root pathogen Fusarium oxysporum. Together, our data identify MIK2 as a novel component in cell wall integrity sensing and suggest that MIK2 is a nexus linking cell wall integrity sensing to growth and environmental cues

Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

Accessory pathways in horses : myth or reality?

Under normal conditions, the annulus fibrosus electrically isolates the atrium from the ventricle and atrial impulses only conduct to the ventricle through the atrioventricular node. Accessory pathways are strands of working myocardial cells that penetrate the annulus fibrosus and directly connect the atrial and ventricular myocardium, bypassing the atrioventricular node. Only a few cases of accessory pathways in horses have been described, although the condition may be underreported because it can be easily missed or mistaken for other arrhythmias. The conduction through the accessory pathway can be bi-directional or uni-directional in the anterograde or retrograde direction. Anterograde conduction along the accessory pathway results in earlier ventricular activation than would be expected if conduction occurred via the atrioventricular node. This is called ventricular pre-excitation and leads to the typical ECG findings of a shortened PQ interval and PQ segment, and abnormal QRS morphology and duration. Ventricular pre-excitation should be differentiated from ventricular premature complexes, accelerated idioventricular rhythm and bundle branch block. Ventricular premature complexes and accelerated idioventricular rhythm show no association with a P wave and can therefore be distinguished from pre-excitation. Bundle branch block and ventricular pre-excitation are both preceded by a P wave, but bundle branch block is characterized by a normal PQ interval. Retrograde conduction via the accessory pathway means that the atrial depolarization conducts normally over the atrioventricular node (orthodromic), depolarizes the ventricle and returns back to the atrium via the accessory pathway. It leads to an ECG pattern with a normal PQ interval and normal QRS morphology but with a retrograde conducted P wave, typically within the ST segment. Subsequently, there are several options. The retrogradely conducted P wave conducts back to the ventricle and initiates the next retrograde P wave which returns to the ventricle, etc..., leading to orthodromic atrioventricular reciprocating tachycardia. It is also possible that the retrogradely conducted P wave is blocked at the atrioventricular node, but as it also resets the sinus node, this leads to bradycardia. It is important for the clinician to realize that conduction over the accessory pathway can be intermittently present which makes it more difficult to diagnose. Little is known about the behaviour of an accessory pathway, the effect on performance and the associated risk in horses. Horses can show very strong changes in their autonomic tone which might influence the conduction pattern when an accessory pathway is present. In humans and dogs, the risk lies in a high prevalence of associated arrhythmias, such as orthodromic atrioventricular reciprocating tachycardia and atrial fibrillation. Atrial fibrillation with anterograde conduction via the accessory pathway can be life-threatening, because a rapid ventricular response can degenerate into ventricular fibrillation, causing sudden cardiac death. Atrial fibrillation was found in a horse with an accessory pathway and resulted in markedly increased heart rates at rest. Without further knowledge of the electrophysiological properties of accessory pathways in horses, these horses should not be considered safe to ride. Page 10 Accessory pathways and related arrhythmias can be treated by destroying the abnormal bundle with radiofrequency catheter ablation. This is the treatment of choice for accessory pathways in humans and dogs and it has a high success rate and low complication rate. Recently, three-dimensional electro-anatomical mapping was performed in a horse with ventricular pre-excitation and showed the precise localisation of an accessory pathway in the craniolateral region of the right atrium. Subsequently, radiofrequency catheter ablation was successfully performed and permanently restored normal conduction. In conclusion, clinicians should be aware that accessory pathways do occur in horses. Threedimensional electro-anatomical mapping followed by radiofrequency ablation might be a treatment option

Effekt der Externen Gegenpulsationstherapie auf die Kollateralarterienproliferation

Introduction: Arteriogenesis is the rapid proliferation of pre-existing collateral arteries and is nature´s most efficient rescue mechanisms to compensate for the loss of arterial inflow under conditions of chronic obstructive atherosclerotic disease. It differs from angiogenesis in fundamental aspects: 1) The speed of arterial growth in diameter can compensate for the deficit in blood flow of large conductance arteries, which is not the case in angiogenic sprouting. 2) Arteriogenesis may be located at non-ischemic zones and results in efficient collateral conductance arteries, whereas angiogenesis is located in the region of ischemia 3) The increase in biomechanical shear-rate is currently seen as the key mechanism to stimulate collateral growth. Taking these fundamentals into account our clinical trials in this thesis focused on following question: Is arteriogenesis a potential therapeutic substrate to enhance myocardial tissue perfusion in patients? Which parameters have to be taken into account to evaluate the collateral macro-circulation as well microcirculation? Is it possible to transfer the concept of shear-stress driven arteriogenesis into the cerebral circulation? Methods: To detect the capacity of the myocardial perfusion and collateral circulation invasive read-out parameters - pressure derived collateral flow index, CFIp- and the microcirculatory index (IMR) were applied; to assess functional relevance of coronary stenosis, fractional flow reserve was used. Further cerebrovascular blood flow at rest and under ECP-therapy was investigated with transcranial-dopplersonography. Results and Conclusion: The results of these trials may be summarized as followed: Upon pre existing coronary stenosis ECP significantly improves collateral conductance and enhances flow reserve (the CFIp improved significantly from 0.08 +/- 0.01 to 0.15 +/- 0.02; P < 0.001; FFR-Index improved from 0.68±0.03 to 0.79±0.03; p=0.001); while in the control group no change was observed. In patients with severe epicardial stenosis microcirculation can only be assessed reliably if collateral circulation is taken into account (CFIp r = 0.3, p = 0.046; FFR r = -0.44, p = c0.03). The findings of ECP treatment in healthy probands are summarized as: ECP does not enhance cerebral blood flow (59±10 vs. 58±13cm/s, n.s.) but flow velocities through-out the ECP therapy are increased compared to rest/baseline (increased shear-rate). Thus this thesis provides 3 important novel findings: 1.External counterpulsation can induce adaptive collateral- growth in patients with CAD and improve myocardial perfusion. 2. Given significant epicardial stenosis microcirculatory indices are efficient in detecting myocardial microcirculatory if collateral circulation in the region of interest is taken into account 3. ECP-treatment increases flow-velocities in the cerebral blood flow - giving rise to the assumption that ECP might induce cerebrovascular arteriogenesis.Hintergrund: Arteriogenese ist ein positives outward-remodeling von prä- existent angelegten kollateralen Anastomosen. Dieser Prozess zählt zu den effizientesten Rescue-Mechanismen des Körpers, einen kompromittierten Blutfluss wiederherzustellen. Arteriogenese unterscheidet sich wesentlich vom Prozess der Angiogenese : 1) Die Geschwindigkeit der kollateralen Proliferation kann einen gestörten Blutfluss in kurzer Zeit wiederherstellen. 2) Arteriogenese findet zumeist in Regionen statt, wo lediglich Blutdruckgradienten vorliegen, nicht aber eine Gewebeischämie. Letztere wiederum ist der wesentliche Auslöser von Angiogenese 3) die Zunahme der intraarteriellen Scherrate ist der wesentliche arteriogene Biomechanismus. Nimmt man diese Aspekte der Arteriogenese als experimentelle Basis von kollateralem Wachstum, haben wir uns in der vorliegenden Dissertation mit folgenden Fragen beschäftigt:1.) Sind Kollateralgefäße ein klinisches Substrat, womit man therapeutisches Wachstum anregen kann? 2.) Welche Parameter eignen sich therapeutische arteriogene Effekte bzw. auch die der Mikrozirkulation zu erfassen? 3.) Kann man das Therapiekonzept der Arteriogenese auf das Gehirn übertragen? 4.) Welche Rolle könnte die Gegenpulsation bei der therapeutischen Erhöhung der Scherrate Rate spielen? Methodisch kamen folgende Techniken zum Einsatz: Kollateraler-Index (CFIp) zur Evaluation der kollateralen Konduktanz, Fraktionelle Flussreserve (FFR) zur Beurteilung der hämodynamischen Relevanz einer Stenose, der mikrozirkulatorische Index (IMR) auf mikrozirkulatorischer Ebene. Neurologisch untersuchten wir den Effekt der Gegenpulsation auf die zerebrovaskuläre Zirkulation mittels Doppler Fluß Analyse. Ergebnisse/Zusammenfassung: ECP verbessert die kollaterale Zirkulation. Dieser Effekt wurde bei gleichbleibender zugrundeliegender Stenose gemessen: Der CFIp verbesserte sich signifikant von 0.08+/-0.01 auf 0.15+/-0.02; P < 0.001. In der Kontrollgruppe hingegen keinen Veränderungen. Dazu passend verbessert sich der FFR-Index in der ECP Gruppe von 0.68±0.03 auf 0.79±0.03 (p=0.001), aber nicht in der Kontrollgruppe (p=0.4). Desweiteren fokussierten wir auf die optimale Detektion des IMR bei Patienten mit einer stabilen KHK. Hierbei zeigte sich, dass je besser die Kollateralisierung war, und je höhergradiger die Stenose, umso mehr war der IMR vom gemessenen CFIp abhängig. Die Überschätzung des IMR korrelierte dabei positiv mit dem CFIp (r=0.3, p=0.046). Im letzten Teil unserer Versuche untersuchen wir den Effekt der ECP auf die zerebrovaskuläre Zirkulation. Interessanterweise zeigte sich, dass sich die mittlere Blutfließgeschwindigkeit unter ECP aufgrund der zerebrovaskuläre Autoregulation nicht verändert. Analysiert man jedoch die Blutflussgeschwindigkeitsprofile pro Herzzyklus, so zeigte sich eine erhöhte Beschleunigung im arteriellen Einstroms bei gleichbleibender Gesamtgeschwindigkeit. Dieser Befund ist von hoher Bedeutung da durch erhöhte Scherraten zerebrovaskuläre Arteriogenese induziert werden kann

Forsøksvirksomhet i en offentlig reformprosess : i hvilken grad ble erfaringene brukt?

Tema for denne studien er helhetlig tjenesteutforming i offentlig forvaltning. Ved å foreta en analyse av sentrale dokumenter som la grunnen for Nav-reformens iverksetting, har jeg sett på hvordan erfaringer fra forsøksvirksomhet har blitt brukt i prosessen fram mot endelig beslutning. Problemstillingen for oppgaven har vært i hvilken grad erfaringene fra to nasjonale forsøk anvendes ved iverksetting av Nav-reformen. Jeg ønsket å se på hvilke erfaringer som ble brukt og hvilke som ikke ble brukt, og jeg har reflektert over hva som kan være grunnen til at det ble slik. Analysen brukes til slutt til å drøfte hvilke funksjoner forsøksvirksomhet kan ha i en offentlig reformprosess. Oppsummeringsvis kan en si at det var mange, og høyst ulike problemstillinger som ble debattert i prosessen. Erfaringer fra forsøkene ble i varierende grad benyttet som argumenter for forslagene. Dels kan det ha sin forklaring i at forsøkene ikke alltid hadde svarene på problemstillingene som var oppe til debatt. En analyse av dokumentene tyder på at det skjedde en innsnevring av problemstillinger underveis i prosessen, slik at det i sterkere grad ble fokusert på organisasjonsmessige løsninger på samordningsutfordringene. Dette kan ha bidratt til for det ene at diskusjonen om virkemiddelbruken ble ”satt på vent”, og for det andre at det igjen resulterte i at erfaringer når det gjaldt fag- og metodeutvikling kom i skyggen i beslutningsprosessen. Til slutt diskuteres hvilken rolle forsøk kan tenkes å spille i offentlige reformprosesser, i forhold