Search

A universal calibrator for the determination of all anti-Xa inhibitors would support laboratory processes. We aimed to test the clinical performance of an anti-Xa assay utilizing a universal edoxaban calibrator to determine clinically relevant concentrations of all anti-Xa inhibitors. Following a pilot study, we enrolled 553 consecutive patients taking rivaroxaban, edoxaban, or apixaban from nine study centers in a prospective cross-sectional study. The Technochrom® anti-Xa assay was conducted using the Technoview® edoxaban calibrator. Using ultra-high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS), anti-Xa inhibitor drug concentrations were determined. Sensitivities and specificities to detect three clinically relevant drug concentrations (30 µgL−1, 50 µgL−1, 100 µgL−1) were determined. Overall, 300 patients treated with rivaroxaban, 221 with apixaban, and 32 with edoxaban were included. The overall correlation coefficient (rs) was 0.95 (95% CI 0.94, 0.96). An area under the receiver operating characteristic curve of 0.96 for 30 µgL−1, 0.98 for 50 µgL−1, and 0.99 for 100 µgL−1 was found. The sensitivities were 92.3% (95% CI 89.2, 94.6), 92.7% (89.4, 95.1), and 94.8% (91.1, 97.0), respectively (specificities 82.2%, 93.7%, and 94.4%). In conclusion, the clinical performance of a universal, edoxaban-calibrated anti-Xa assay was solid and most drug concentrations were predicted correctly.

Adaptive behaviour necessitates the formation of memories for fearful events, but also that these memories can be extinguished. Effective extinction prevents excessive and persistent reactions to perceived threat, as can occur in anxiety and ‘trauma- and stressor-related’ disorders1. However, although there is evidence that fear learning and extinction are mediated by distinct neural circuits, the nature of the interaction between these circuits remains poorly understood2–6. Here, through a combination of in vivo calcium imaging, functional manipulations, and slice physiology, we show that distinct inhibitory clusters of intercalated neurons (ITCs) in the mouse amygdala exert diametrically opposed roles during the acquisition and retrieval of fear extinction memory. Furthermore, we find that the ITC clusters antagonize one another through mutual synaptic inhibition and differentially access functionally distinct cortical- and midbrain-projecting amygdala output pathways. Our findings show that the balance of activity between ITC clusters represents a unique regulatory motif that orchestrates a distributed neural circuitry, which in turn regulates the switch between high- and low-fear states. These findings suggest that the ITCs have a broader role in a range of amygdala functions and associated brain states that underpins the capacity to adapt to salient environmental demands. Distinct clusters of inhibitory neurons in the mouse amygdala perform opposing roles in fear extinction.

α-Thalassemia (α-thal) is caused by DNA deletions or point mutations in the genes coding for the α-globin chains and can lead to hemolytic anemia in its carriers. If only one of the four α genes is affected, the mutation is mostly discovered by chance, as the carriers are asymptomatic. Hb Évora (

Despite the widely known role of dopamine in reinforcement learning, how the patterns of dopamine release that are critical to the acquisition, performance, and extinction of conditioned responses are generated is poorly resolved. Here, we demonstrate that the coordinated actions of two ion channels, Kv4.3 and BKCa1.1, control the pattern of dopamine neuron firing and dopamine release on different time scales to regulate separate phases of reinforced behavior and extinction in mice. Inactivation of Kv4.3 in VTA dopamine neurons increasesex vivopacemaker activity and excitability that is associated with decreased rates of bursting and increasedin vivoramping dynamics prior to lever press in a learned instrumental response paradigm. Loss of Kv4.3 enhances performance of the learned response and facilitates extinction. In contrast, loss of BKCa1.1 increases duration of burst firing and phasic dopamine release that enhances learning of an instrumental response. Inactivation of BKCa1.1 also enhances extinction burst lever pressing in early extinction training that is associated with a greater change in activity between reinforced and unreinforced actions. These data demonstrate that disruption of intrinsic regulators of neuronal activity differentially impacts dopamine dynamics observed during reinforcement learning and extinction behaviors.TeaserIon channels in midbrain dopamine neurons are critical for patterning action potential firing, dopamine release, and learning.

A universal anti-Xa assay for the determination of rivaroxaban, apixaban and edoxaban drug concentrations would simplify laboratory procedures and facilitate widespread implementation. Following two pilot studies analysing spiked samples and material from 698 patients, we conducted a prospective multicentre cross-sectional study, including 867 patients treated with rivaroxaban, apixaban or edoxaban in clinical practice to comprehensively evaluate a simple, readily available anti-Xa assay that would accurately measure drug concentrations and correctly predict relevant levels in clinical practice. Anti-Xa activity was measured by an assay calibrated with low-molecular-weight heparin (LMWH) in addition to ultra-high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). As an external validation, LMWH-calibrated anti-Xa activity was also determined in nine external laboratories. The LMWH-calibrated anti-Xa activity correlated strongly with rivaroxaban, apixaban or edoxaban drug levels [r s = 0·98, 95% confidence interval (CI) 0·98-0·98]. The sensitivity for the clinically relevant cut-off levels of 30, 50 and 100 µg/l was 96·2% (95% CI 94·4-97·4), 96·4% (95% CI 94·4-97·7) and 96·7% (95% CI 94·3-98·1) respectively. Concordant results were obtained in the external validation study. In conclusion, a universal, LMWH-calibrated anti-Xa assay accurately measured rivaroxaban, apixaban and edoxaban concentrations and correctly predicted relevant drug concentrations in clinical practice.

Las investigaciones en el campo de la Mercadotecnia tienen como eje central el análisis del comportamiento de los mercados, de sus consumidores y de los diferentes elementos que los componen. Los métodos utilizados para su estudio han sido diversos y han aportado conocimiento científico. En este sentido, el estudio de caso se suele utilizar para investigar y documentar un hecho sucedido en una organización, aplicando metodología científica con base en la revisión rigurosa de la literatura especializada y en la experiencia del autor. El libro Estrategias de mercadotecnia aplicadas a las Pymes de México y Colombia es el resultado del trabajo colaborativo entre la Red Internacional de Investigadores en Marketing, (RIIM), la Facultad de Contaduría y Administración (FCA) de la Universidad Nacional Autónoma de México (UNAM) y la Facultad de Ciencias Económicas y Administrativas de la Universidad de Bogotá Jorge Tadeo Lozano (UTADEO), de Colombia; por ello, consideramos esta obra como una herramienta de difusión de los trabajos emprendidos entre dos importantes universidades, mexicana y colombiana, que buscan dar a conocer problemáticas específicas en el campo de la mercadotecnia en empresas pequeñas y medianas (Pymes) de la región de influencia de cada una de las universidades participantes.

In this essay, I return to the Spanish edition of Merlin’s Viaje a la Habana (1844), reading it with fresh eyes not only as a poetic homage to the city of Havana, but also as a foundational work in the Cuban literary tradition. Merlin’s Viaje a la Habana is emblematic of nineteenth-century literary and visual cartographies that mapped colonial Havana in a romantic mode. During her two-month stay (June–July, 1840), Merlin’s sentimental return to her native city is tinged with remembrance and renewal of lost family ties. While an accent on affect and the poetry of place haunts every episode in the travelogue, the text unfolds as a literary map of nineteenth-century Havana that sheds light on an early, formative stage in the formation of Cuban national identity. I examine Merlin’s literary mapping of colonial Havana through various spatial tropes: sublime tropics (the topography of the port), the contrast between public and private spaces, and the effect of surveillance in the city. Lastly, I look at how Merlin’s travelogue constructs a social history of colonial Havana at a threshold moment not only in her life story—the eve of her final farewell—but also of the nation.

Deficiencies in the ability to extinguish fear is a hallmark of Trauma- and stressor-related disorders, Anxiety disorders, and certain other neuropsychiatric conditions. Hence, a greater understanding of the brain mechanisms involved in the inhibition of fear is of significant translational relevance. Previous studies in rodents have shown that glutamatergic projections from the infralimbic prefrontal cortex (IL) to basolateral amygdala (BLA) play a crucial instructional role in the formation of extinction memories, and also indicate that variation in the strength of this input correlates with extinction efficacy. To further examine the relationship between the IL→BLA pathway and extinction we expressed three different titers of the excitatory opsin, channelrhodopsin (ChR2), in IL neurons and photostimulated their projections in the BLA during partial extinction training. The behavioral effects of photoexcitation differed across the titer groups: the low titer had no effect, the medium titer selectively facilitated extinction memory formation, and the high titer produced both an acute suppression of fear and a decrease in fear during (light-free) extinction retrieval. We discuss various possible explanations for these titer-specific effects, including the possibility of IL-mediated inhibition of BLA fear-encoding neurons under conditions of sufficiently strong photoexcitation. These findings further support the role of IL→BLA pathway in regulating fear and highlight the importance of methodological factors in optogenetic studies of neural circuits underling behavior.

The functional activity of von Willebrand factor (VWF) is most frequently measured by using the ristocetin cofactor assay (VWF:RCo). However, the method's drawbacks include unsatisfactory precision, sensitivity and availability of automated system applications. We have developed an alternative assay (INNOVANCE VWF Ac) that is based on the binding of VWF to recombinant glycoprotein Ib (GPIb). Two gain-of-function mutations were introduced into a GPIb fragment, allowing an assay format without ristocetin. Fully automated assay applications are available for the BCS/BCS XP systems and the Sysmex CS-2000i, Sysmex CA-7000, Sysmex CA-1500 and Sysmex CA-560 systems.The INNOVANCE VWF Ac assay measuring range extends from 4 to 600% VWF for all systems except the Sysmex CA-560 system. Within-device precision values were found to be between 2 and 7%. The limit of detection was below 2.2% VWF. In a study on the BCS XP system, a total number of 580 sample results yielded a correlation to the VWF:RCo assay of r equal to 0.99 (slope = 0.96). Very similar results were observed when von Willebrand disease samples type 1, 2A, 2B, 2M, 2N and 3 were investigated with the new assay and the VWF:RCo assay. The excellent performance data and comparability to VWF:RCo, together with the ease of use, led us to the conclusion that the ristocetin cofactor assay can be replaced by the new GPIb-binding assay to reliably diagnosing patients with von Willebrand disease.

ESSENTIALS Accurate determination of anticoagulant plasma concentration is important in clinical practice. We studied the accuracy and consistency of anti-Xa assays for rivaroxaban in a multicentre study. In a range between 50 and 200 μg L(-1) , anti-Xa activity correlated well with plasma concentrations. The clinical value might be limited by overestimation and intra- and inter-individual variation. SUMMARY Background Determining the plasma level of direct oral anticoagulants reliably is important in the work-up of complex clinical situations. Objectives To study the accuracy and consistency of anti-Xa assays for rivaroxaban plasma concentration in a prospective, multicenter evaluation study employing different reagents and analytical platforms. Methods Rivaroxaban 20 mg was administered once daily to 20 healthy volunteers and blood samples were taken at peak and trough levels (clinicaltrials.gov NCT01710267). Anti-Xa activity was determined in 10 major laboratories using different reagents and analyzers; corresponding rivaroxaban plasma concentrations were measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS). Findings Overall Pearson's correlation coefficient of anti-Xa levels and HPLC-MS results was 0.99 for Biophen(®) Heparin (95% CI, 0.99, 0.99), Biophen(®) DiXaI (95% CI, 0.99, 0.99) and STA(®) anti-Xa liquid (95% CI, 0.99, 1.00). Correlation was lower in rivaroxaban concentrations below 50 μg L(-1) and above 200 μg L(-1) . The overall bias of the Bland-Altman difference plot was 14.7 μg L(-1) for Biophen Heparin, 17.9 μg L(-1) for Biophen DiXal and 19.0 μg L(-1) for STA anti-Xa liquid. Agreement between laboratories was high at peak level but limited at trough level. Conclusions Anti-Xa activity correlated well with rivaroxaban plasma concentrations, especially in a range between 50 and 200 μg L(-1) . However, anti-Xa assays systematically overestimated rivaroxaban concentration as compared with HPLC-MS, particularly at higher concentrations. This overestimation, coupled with an apparent interindividual variation, might affect the interpretation of results in some situations.

Background Point-of-care testing (POCT) is regularly used to assess haemostasis in various clinical settings. The impact of rivaroxaban on those POCT is still elusive. We aimed to study the effects of rivaroxaban on most commonly used POCT assays. Methods Blood samples were taken before, 3 h, and 24 h after administration of 20 mg rivaroxaban to 20 healthy volunteers as part of a prospective, multicenter validation study ( clinicaltrials.gov NCT01710267 ). Blood samples were analysed with thromboelastometry (ROTEM®), two platelet function assays (INNOVANCE® PFA-200 and Multiplate®), and the CoaguChek® XS. Rivaroxaban plasma levels were determined using liquid chromatography-mass spectrometry. Results Rivaroxaban significantly modified some thromboelastometry parameters (CT INTEM: mean difference 56.1 s, 95% CI: 41.8, 70.3; CT EXTEM: 47.5 s, 95% CI: 37.8, 57.1; CT HEPTEM: 50.1 s, 95% CI: 34.7, 65.6), and CoaguChek® XS parameters (prothrombin time: mean difference 3.8 s, 95% CI: 3.3, 4.2; INR: 0.32, 95% CI: 0.27, 0.38; prothrombin ratio: − 36.1%, 95% CI: − 32.3, − 39.9). CT EXTEM and INR showed a moderate correlation with rivaroxaban plasma levels (r = 0.83; 95% CI 0.69, 0.9 and r = 0.83; 95% CI 0.70, 0.91, respectively) and a high sensitivity to detect rivaroxaban treatment at peak levels (0.95; 95% CI: 0.76, 1.0 and 0.90, 95% CI 0.70, 0.99, respectively). Conclusions Rivaroxaban 20 mg treatment significantly alters ROTEM® and CoaguChek® XS parameters. Even though POCT do not allow precise quantification of rivaroxaban plasma concentration, CT EXTEM and CoaguChek XS detect the presence of rivaroxaban at peak level with a high sensitivity.

The whale shark Rhincodon typus is a popular focal species in the marine tourism industry. We analysed 689 encounters with at least 142 individual sharks during 2008–2010 to assess their behaviour in the presence of swimmers at Tofo Beach, Mozambique. Sharks varied in size (estimated 3.0–9.5 m total length) and the majority (74%) were males. The sharks displayed avoidance behaviours during 64.7% of encounters. Encounter duration decreased significantly, from 12 minutes 37 s with undisturbed sharks to 8 minutes 25 s when sharks expressed avoidance behaviours, indicating that interactions with tourists affected the sharks’ short-term behaviour. However, during the 2.5-year study period we found no trend in the mean encounter duration, the overall expression of avoidance behaviour or the likelihood of an individual shark exhibiting avoidance behaviours. Potential effects of tourism may be mitigated by the non-breeding status and transient behaviour of sharks at this aggregation site.

In the last few decades we have seen a significant decrease in the rates of analytical errors in clinical laboratories. The test performances have improved, new parameters have been introduced, as well as internal and external quality controls have been used for the monitoring of accuracy. Currently available evidence demonstrates that the pre- and post-analytical steps show higher error rates (up to 70 % of all errors) than the analytical phase. Recognition of the weak points of the preanalytical phase and search for appropriate solutions in case of discrepancies will finally help to lead to the correct therapeutic strategy. In order to avoid problems in the preanaytical phase in hematology it is very important to consider some essential issues. The patients must be identified in appropriate form, the blood collection for the requested tests must be made using the appropriate tubes in the specified sequence and the samples must be transported to the lab at the right temperature and on time to be analysed. In case of special tests additional information for the lab is very important for the interpretation of the results. In case of unexpected results the lab should contact the responsible physician in order to look for an adequate explanation for the abnormal findings. With help of several cases of the daily haematology routine we want to point out some preanalytical problems.

article i nfo Introduction: Rivaroxaban (RXA) is licensed for prophylaxis of venous thromboembolism after major orthopaedic surgery of the lower limbs. Currently, no test to quantify RXA in plasma has been validated in an inter-laboratory setting. Our study had three aims: to assess i) the feasibility of RXA quantification with a commercial anti-FXa assay, ii) its accuracy and precision in an inter-laboratory setting, and iii) the influence of 10 mg of RXA on routine coagulation tests. Methods: The same chromogenic anti-FXa assay (Hyphen BioMed) was used in all participating laboratories. RXA calibrators and sets of blinded probes (aim ii.) were prepared in vitro by spiking normal plasma. The precise RXA content was assessed by high-pressure liquid chromatography-tandem mass spectrometry. For ex-vivo studies (aim iii), plasma samples from 20 healthy volunteers taken before and 2 - 3 hours after ingestion of 10 mg of RXA were analyzed by participating laboratories. Results: RXA can be assayed chromogenically. Among the participating laboratories, the mean accuracy and the mean coefficient of variation for precision of RXA quantification were 7.0% and 8.8%, respectively. Mean RXA concentration was 114±43 μg/L.RXA significantly altered prothrombin time, activated partial thromboplastin time, factor analysis for intrinsic and extrinsic factors. Determinations of thrombin time, fibrinogen, FXIII and D-Dimer levels were not affected. Conclusions: RXA plasma levels can be quantified accurately and precisely by a chromogenic anti-FXa assay on different coagulometers in different laboratories. Ingestion of 10 mg RXA results in significant alterations of both PT- and aPTT-based coagulation assays.

1.The whale shark (Rhincodon typus) is a popular focal species within the global marine tourism industry. Although this has contributed to increased protection being granted to the species in several countries, tourism itself can be detrimental to the sharks in the absence of appropriate management. Potential impacts can be mitigated, at least in the short term, by adherence to well-designed interaction guidelines. 2.A burgeoning marine tourism industry based on swimming with whale sharks has developed at Tofo Beach in Mozambique. However, no formal management is currently in place at this site. 3.The behaviour of whale sharks during interactions with boats and swimmers were recorded during 137 commercial snorkelling trips run from Tofo Beach over a 20 month period. Whale sharks were encountered on 87% of trips, which operated year-round. 4.Boat proximity and shark size were significant predictors of avoidance behaviour. No avoidance responses were recorded at >20 m boat distance. 5.The mean in-water interaction time between sharks and swimmers was 8 min 48 s overall. There was a significant decrease in interaction times during encounters where sharks expressed avoidance behaviours, and also in cases where sharks had expressed boat avoidance behaviour before swimmers entered the water. 6.It is suggested that mean encounter times can be extended through adherence to a basic Code of Conduct for operators and swimmers that enforces minimum distances between the sharks, boats and swimmers. Using encounter time as a measure of the ‘success’ of interactions holds promise, as longer encounters appear to be indicative of lower impacts on sharks while also providing higher customer satisfaction for swimmers. Copyright © 2010 John Wiley & Sons, Ltd.

Objective: To reach the recovery and identification of antioxidant polyphenolic compounds from Nephelium lappaceum L. (Mexican variety) husk using ultrasound-assisted extraction and liquid chromatography/mass spectrometry as well as the in vitro antioxidant activity. Methods: Rambutan husk extracts were obtained by ultrasound-assisted extraction, mass/ volume ratio, water/ethanol percentage and extraction time were evaluated. Once the best extraction condition of polyphenolic compounds was defined, a polyphenolic fraction was recovered using Ambetlite XAD-16. The total content of antioxidant polyphenolic compounds was determined by summation of the total hydrolysable polyphenol and total condensed polyphenol contents. Recovered compounds were identified by FTIR (ATR) spectroscopy and HPLC/ESI/MS. The antioxidant activity was carried out by ABTS, DPPH and lipid oxidation inhibition in vitro methods. Results: In Mexican variety rambutan husk, the total polyphenolic content was 487.67 mg/g, after ultrasound-assisted extraction. According to the HPLC/ESI/MS analysis 12 antioxidant polyphenolic compounds were identified, mostly ellagitannins such as geraniin, corilagin and ellagic acid. The antioxidant activity determined by ABTS, DPPH and lipid oxidation inhibition methods was demonstrated. The main functional groups of the identified compounds were determined by FTIR analysis. Conclusions: It was demonstrated that ultrasound-assisted extraction was effective and allowed the extraction and recovery of antioxidant polyphenolic compounds. Furthermore Mexican variety rambutan husk is an important source for recovering polyphenolic compounds with antioxidant activity, these compounds have potential application for the treatment/prevention of various diseases related to cancer and pathogenic microorganisms.

The aim of this study was to provide data on the main toxic and trace metals in the liver and kidney of domestic dogs in Galicia, NW Spain and to evaluate the influence of diet, sex, age, and pathological lesions on metal accumulation. Samples of the liver and kidney from 77 male and female dogs, aged between 6 mo and 18 yr, were collected during ordinary necropsy. Samples were acid-digested and metal concentrations determined by inductively coupled plasma (ICP)-mass spectrometry and ICP-atomic emission spectrometry. Mean toxic metal concentrations (geometric means for liver and kidney respectively) were 11.5 and 15.8 microg/kg wet weight for As, 56.3 and 166 microg/kg for Cd, 32.7 and 51.9 microg/kg for Hg, and 60.1 and 23.6 microg/kg for Pb. For the trace metals, these concentrations were respectively 16.3 and 21.0 microg/kg for Co, 57.6 and 43.9 microg/kg for Cr, 42.1 and 5.95 mg/kg for Cu, 394 mg/kg and 95.7 mg/kg for Fe, 2.39 and 0.956 mg/kg for Mn, 0.522 and 0.357 mg/kg for Mo, 23.8 and 26.8 microg/kg for Ni, 0.686 and 1.39 mg/kg for Se, and 46.7 and 26.0 mg/kg for Zn. Cd concentrations in the kidney significantly increased with age, and Co concentrations in the liver and kidney significantly decreased with age. Hepatic Pb concentrations were significantly higher in growing (1 yr) and old (10 yr) dogs. Animals with pathological lesions showed significantly higher Co and lower Mn and Zn concentrations in liver than animals without macroscopic abnormalities. Dogs that received commercial diets in general showed low variability in hepatic mineral status compared to animals that receive homemade feeds or a mixture of commercial and homemade feeds.

Blutungen gehorten schon immer zu den Alarmsignalen in allen Kulturen und sozialen Schichten, sie gehoren zum menschlichen Alltag. Die Herausforderung fur den Arzt ist es, zwischen normaler und pathologischer Blutung zu unterscheiden, um grosseren Blutverlust und Blutungskomplikationen zu vermeiden.