Continuum of vasodilator stress from rest to contrast medium to adenosine hyperemia for fractional flow reserve assessment

Objectives: This study compared the diagnostic performance with adenosine-derived fractional flow reserve (FFR) ≤0.8 of contrast-based FFR (cFFR), resting distal pressure (Pd)/aortic pressure (Pa), and the instantaneous wave-free ratio (iFR). Background: FFR objectively identifies lesions that benefit from medical therapy versus revascularization. However, FFR requires maximal vasodilation, usually achieved with adenosine. Radiographic contrast injection causes submaximal coronary hyperemia. Therefore, intracoronary contrast could provide an easy and inexpensive tool for predicting FFR. Methods: We recruited patients undergoing routine FFR assessment and made paired, repeated measurements of all physiology metrics (Pd/Pa, iFR, cFFR, and FFR). Contrast medium and dose were per local practice, as was the dose of intracoronary adenosine. Operators were encouraged to perform both intracoronary and intravenous adenosine assessments and a final drift check to assess wire calibration. A central core lab analyzed blinded pressure tracings in a standardized fashion. Results: A total of 763 subjects were enrolled from 12 international centers. Contrast volume was 8 ± 2 ml per measurement, and 8 different contrast media were used. Repeated measurements of each metric showed a bias <0.005, but a lower SD (less variability) for cFFR than resting indexes. Although Pd/Pa and iFR demonstrated equivalent performance against FFR ≤0.8 (78.5% vs. 79.9% accuracy; p = 0.78; area under the receiver-operating characteristic curve: 0.875 vs. 0.881; p = 0.35), cFFR improved both metrics (85.8% accuracy and 0.930 area; p < 0.001 for each) with an optimal binary threshold of 0.83. A hybrid decision-making strategy using cFFR required adenosine less often than when based on either Pd/Pa or iFR. Conclusions: cFFR provides diagnostic performance superior to that of Pd/Pa or iFR for predicting FFR. For clinical scenarios or health care systems in which adenosine is contraindicated or prohibitively expensive, cFFR offers a universal technique to simplify invasive coronary physiological assessments. Yet FFR remains the reference standard for diagnostic certainty as even cFFR reached only ∼85% agreement

Evaluation of the Linear Relationship Between Pulse Arrival Time and Blood Pressure in ICU Patients: Potential and Limitations

A variety of techniques based on the indirect measurement of blood pressure (BP) by Pulse Transit Time (PTT) have been explored over the past few years. Such an approach has the potential in providing continuous and non-invasive beat to beat blood pressure without the use of a cuff. Pulse Arrival Time (PAT) which includes the cardiac pre-ejection period has been proposed as a surrogate of PTT, however, the balance between its questioned accuracy and measurement simplicity has yet to be established. The present work assessed the degree of linear relationship between PAT and blood pressure on 96 h of continuous electrocardiography and invasive radial blood pressure waveforms in a group of 11 young ICU patients. Participants were selected according to strict exclusion criteria including no use of vasoactive medications and presence of clinical conditions associated with cardiovascular diseases. The average range of variation for diastolic BP was 60 to 79 mmHg while systolic BP varied between 123 and 158 mmHg in the study database. The overall Pearson correlation coefficient for systolic and diastolic blood pressure was −0.5 and −0.42, respectively, while the mean absolute error was 3.9 and 7.6 mmHg. It was concluded that the utilization of PAT for the continuous non-invasive blood pressure estimation is rather limited according to the experimental setup, nonetheless the correlation coefficient performed better when the range of variation of blood pressure was high over periods of 30 min suggesting that PAT has the potential to be used as indicator of changes relating to hypertensive or hypotensive episodes

Role of Game Theory in Public Health

Game theory, a branch of applied mathematics has been utilized by researchers in various fields including health to arrive at practical solutions to contemporary challenges. The article aims to introduce the subject to medical fraternity in India and recommends that the theory should be included in the syllabus of post graduate students of community medicine so that future generations of public health experts are aware of the theory and its potential use to find tangible solutions to public health issues

Evaluation Of Serum High-sensitivity C-reactive Protein Levels During Various Periods Of Pregnancy In Woman, Infected With Parvovirus - B19 Infection

The aim of the research was analyze of C-reactive protein levels in serum blood samples during various periods of pregnancy in women, infected with parvovirus B19 and in case of presence of clinical complications.129 pregnant women, infected with parvovirus B19 infection and 16 women with physiological pregnancy during first, second and third trimesters of pregnancy were examined. Depending on the presence or absence of clinical complications each group of pregnant women (I, II, III) was divided into two subgroups. The concentration of C-reactive protein in blood serum was determined by the method of immunoassay analysis using diagnostic sets of reagents (ELISA kits, USA). Statistical processing of data was carried out using the package of applied programs Microsoft Office Excel 2010 and StatSoft Statistica 6.1.The mean age of pregnant woman in our study was 26±6 years. In the Iand II groups of infected B19 parvovirus pregnant women were identified a significant increasing of C-reactive protein levels compared to controls by 62.5 % and 50.0 % (p<0.05). The largest increasing of C-reactive protein level relative to control values was observed in women with clinical complications in different pregnancy periods (p<0.05).An increase levels of the marker of systemic inflammation the C-reactive protein in the blood testifies to its active participation in the launch of a complex mechanism for the development of labor activity and the occurrence of fetal disorders, which was confirmed in groups of pregnant women with clinical complications in different periods of pregnancy

Improvement in Hemodynamic Responses to Metaboreflex Activation after One Year of Training in Spinal Cord Injured Humans

Spinal cord injured (SCI) individuals show an altered hemodynamic response to metaboreflex activation due to a reduced capacity to vasoconstrict the venous and arterial vessels below the level of the lesion. Exercise training was found to enhance circulating catecholamines and to improve cardiac preload and venous tone in response to exercise in SCI subjects. Therefore, training would result in enhanced diastolic function and capacity to vasoconstrict circulation. The aim of this study was to test the hypothesis that one year of training improves hemodynamic response to metaboreflex activation in these subjects. Nine SCI individuals were enrolled and underwent a metaboreflex activation test at the beginning of the study (T0) and after one year of training (T1). Hemodynamics were assessed by impedance cardiography and echocardiography at both T0 and T1. Results show that there was an increment in cardiac output response due to metaboreflex activity at T1 as compared to T0 (545.4 ± 683.9 mL · min(-1) versus 220.5 ± 745.4 mL · min(-1), P < 0.05). Moreover, ventricular filling rate response was higher at T1 than at T0. Similarly, end-diastolic volume response was increased after training. We concluded that a period of training can successfully improve hemodynamic response to muscle metaboreflex activation in SCI subjects

In vivo measurements with robust silicon-based multielectrode arrays with extreme shaft lengths

In this paper, manufacturing and in vivo testing of extreme-long Si-based neural microelectrode arrays are presented. Probes with different shaft lengths (15–70 mm) are formed by deep reactive ion etching and have been equipped with platinum electrodes of various configurations. In vivo measurements on rats indicate good mechanical stability, robust implantation, and targeting capability. High-quality signals have been recorded from different locations of the cerebrum of the rodents. The accompanied tissue damage is characterized by histology

Regular treatment with formoterol versus regular treatment with salmeterol for chronic asthma: serious adverse events

An increase in serious adverse events with both regular formoterol and regular salmeterol in chronic asthma has been demonstrated in previous Cochrane reviews.ObjectivesWe set out to compare the risks of mortality and non-fatal serious adverse events in trials which have randomised patients with chronic asthma to regular formoterol versus regular salmeterol.Search methodsWe identified trials using the Cochrane Airways Group Specialised Register of trials. We checked manufacturers' websites of clinical trial registers for unpublished trial data and also checked Food and Drug Administration (FDA) submissions in relation to formoterol and salmeterol. The date of the most recent search was January 2012.Selection criteriaWe included controlled, parallel-design clinical trials on patients of any age and with any severity of asthma if they randomised patients to treatment with regular formoterol versus regular salmeterol (without randomised inhaled corticosteroids), and were of at least 12 weeks' duration.Data collection and analysisTwo authors independently selected trials for inclusion in the review and extracted outcome data. We sought unpublished data on mortality and serious adverse events from the sponsors and authors.Main resultsThe review included four studies (involving 1116 adults and 156 children). All studies were open label and recruited patients who were already taking inhaled corticosteroids for their asthma, and all studies contributed data on serious adverse events. All studies compared formoterol 12 mu g versus salmeterol 50 mu g twice daily. The adult studies were all comparing Foradil Aerolizer with Serevent Diskus, and the children's study compared Oxis Turbohaler to Serevent Accuhaler. There was only one death in an adult (which was unrelated to asthma) and none in children, and there were no significant differences in non-fatal serious adverse events comparing formoterol to salmeterol in adults (Peto odds ratio (OR) 0.77; 95% confidence interval (CI) 0.46 to 1.28), or children (Peto OR 0.95; 95% CI 0.06 to 15.33). Over a six-month period, in studies involving adults that contributed to this analysis, the percentages with serious adverse events were 5.1% for formoterol and 6.4% for salmeterol; and over a three-month period the percentages of children with serious adverse events were 1.3% for formoterol and 1.3% for salmeterol.Authors' conclusionsWe identified four studies comparing regular formoterol to regular salmeterol (without randomised inhaled corticosteroids, but all participants were on regular background inhaled corticosteroids). The events were infrequent and consequently too few patients have been studied to allow any firm conclusions to be drawn about the relative safety of formoterol and salmeterol. Asthma-related serious adverse events were rare and there were no reported asthma-related deaths

Blood lactate clearance during active recovery after an intense running bout depends on the intensity of the active recovery

High-intensity exercise training contributes to the production and accumulation of blood lactate, which is cleared by active recovery. However, there is no commonly agreed intensity or mode for clearing accumulated blood lactate. We studied clearance of accumulated blood lactate during recovery at various exercise intensities at or below the lactate threshold after high-intensity interval runs that prompted lactate accumulation. Ten males repeated 5-min running bouts at 90% of maximal oxygen uptake ([Vdot]O2max), which increased blood lactate concentration from 1.0 ± 0.1 to 3.9 ± 0.3 mmol · l-1. This was followed by recovery exercises ranging from 0 to 100% of lactate threshold. Repeated blood lactate measurements showed faster clearance of lactate during active versus passive recovery, and that the decrease in lactate was more rapid during higher (60-100% of lactate threshold) than lower (0-40% of lactate threshold) (P &#60; 0.05) intensities. The more detailed curve and rate analyses showed that active recovery at 80-100% of lactate threshold had shorter time constants for 67% lactate clearance and higher peak clearance rates than 40% of lactate threshold or passive recovery (P &#60; 0.05). Finally, examination of self-regulated intensities showed enhanced lactate clearance during higher versus lower intensities, further validating the intensity dependence of clearance of accumulated blood lactate. Therefore, active recovery after strenuous exercise clears accumulated blood lactate faster than passive recovery in an intensity-dependent manner. Maximum clearance occurred at active recovery close to the lactate threshold

Investigation of the limits of nanoscale filopodial interactions

Mesenchymal stem cells are sensitive to changes in feature height, order and spacing. We had previously noted that there was an inverse relationship between osteoinductive potential and feature height on 15-, 55- and 90 nm-high titania nanopillars, with 15 nm-high pillars being the most effective substrate at inducing osteogenesis of human mesenchymal stem cells. The osteoinductive effect was somewhat diminished by decreasing the feature height to 8 nm, however, which suggested that there was a cut-off point, potentially associated with a change in cell–nanofeature interactions. To investigate this further, in this study, a scanning electron microscopy/three-dimensional scanning electron microscopy approach was used to examine the interactions between mesenchymal stem cells and the 8 and 15 nm nanopillared surfaces. As expected, the cells adopted a predominantly filopodial mode of interaction with the 15 nm-high pillars. Interestingly, fine nanoscale membrane projections, which we have termed ‘nanopodia,’ were also employed by the cells on the 8 nm pillars, and it seems that this is analogous to the cells ‘clinging on with their fingertips’ to this scale of features