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Aim: Clinical observations suggest that alternans in action potential (AP) characteristics presages breakdown of normal ordered cardiac electrical activity culminating in ventricular arrhythmogenesis. We compared such temporal nonuniformities in monophasic action potential (MAP) waveforms in left (LV) and right ventricular (RV) epicardia and endocardia of Langendorff-perfused murine wild-type (WT), and Scn5a+/− hearts modelling Brugada syndrome (BrS) for the first time. Methods: A dynamic pacing protocol imposed successively incremented steady pacing rates between 5.5 and 33 Hz. A signal analysis algorithm detected sequences of >10 beats showing alternans. Results were compared before and following the introduction of flecainide (10 μm) and quinidine (5 μm) known to exert pro- and anti-arrhythmic effects in BrS. Results: Sustained and transient amplitude and duration alternans were both frequently followed by ventricular ectopic beats and ventricular tachycardia or fibrillation. Diastolic intervals (DIs) that coincided with onsets of transient (tr) or sustained (ss) alternans in MAP duration (DI*) and amplitude (DI′) were determined. Kruskal–Wallis tests followed by Bonferroni-corrected Mann–Whitney U-tests were applied to these DI results sorted by recording site, pharmacological conditions or experimental populations. WT hearts showed no significant heterogeneities in any DI. Untreated Scn5a+/− hearts showed earlier onsets of transient but not sustained duration alternans in LV endocardium compared with RV endocardium or LV epicardium. Flecainide administration caused earlier onsets of both transient and sustained duration alternans selectively in the RV epicardium in the Scn5a+/− hearts. Conclusion: These findings in a genetic model thus implicate RV epicardial changes in the arrhythmogenicity produced by flecainide challenge in previously asymptomatic clinical BrS.

A study of agricultural practices around New Philadelphia, Illinois, and a comparison of these practices with those in the regions from whence the New Philadelphia residents came, tests the definitions of Upland South, Midland, and Northern (or Yankee) subsistence traditions. Using data from the U.S. census reports and agriculture schedules from 1840 and 1850, the choices of crops and livestock made by farmers in New York, Ohio, and Kentucky are compared to those made in the New Philadelphia community. Regional differences are found to have existed which influenced the farmers who lived in the area of that town in western Illinois. This study provides a firmer understanding of the subsistence and economic practices of the community.

Three years of research at the New Philadelphia site in western Illinois have provided the opportunity to integrate archaeological and documentary information to improve the understanding of family organization, economic patterns, and subsistence activities in this small, racially integrated, agrarian community. Analysis of the faunal remains recovered, and the study of available historical records, permit one to compare and contrast households within the town site, and to explore how the different regional backgrounds of the town’s residents affected their livelihoods. Patterns of migration, regional origin, social organization, and intricate familial relationships are continuing to emerge even as new data are being collected. Because of its small size and its discrete and relatively recent existence, New Philadelphia presents a unique opportunity to study the entire history of a community in minute detail.

Little information is known about the behaviour of ultrafine particles (UFP) on a citywide scale. Total particle number flux, dominated by UFP, and other meteorological parameters were collected from tower sites in Manchester, London, Edinburgh and Gothenburg between 1999 and 2006 using the eddy covariance technique. Averaged diurnal cycles were produced for particle number flux, concentration, sensible heat flux, emission velocity, friction velocity, wind speed and temperature. UFP flux cycles showed clear diurnal trends which were linked to traffic activity and local sources. Wind sector analysis showed contributions to flux from local heavily urbanised areas. A simple parameterised model linking UFP flux to traffic activity, sensible heat and friction velocity above the city was produced.

The seed morphology of 79 species of neotropical Miconieae (Melastomataceae) is presented. These species have been chosen, in majority, from the polyphyletic genus Leandra. A few other species from the polyphyletic genera Miconia, Ossaea, and Clidemia were also sampled, because of potential similarities. Sixteen morphological seed types are defined after analysis through light microscopy and scanning electron microscopy. The seed morphology appears to possess a great deal of variability on the level of the overall shape as well as the structure and the surface of the testa. The different types defined here do not match with genera or sections, but rather are composed of species coming from different genera. In comparison with a preliminary molecular phylogeny study done on Leandra, some types of seeds are related to well supported clades. In some cases seed morphology corresponds with natural groups of species, thus being of high phylogenetic importance.

We propose here two new names, six new synonyms, and five lectotypifications for South American Miconia (Melastomataceae). We propose M. baumgratziana instead of M. angustifolia; and M. labiakiana instead of M. plumosa. Miconia elaeagnoides is an illegitimate name, but since it has a synonym—M. dichrophylla—the former is now recognized as a synonym of the latter. Miconia eriantha is placed in the synonymy of M. racemifera;Miconia pohliana in the synonymy ofM. leucocarpa;Miconia pseudopetroniana in the synonymy of M. petroniana; Miconia verticillata in the synonymy of M. elaeodendrum; and Miconia pauciflora in the synonymy of M. brasiliensis. We propose lectotypes for M. angustifolia, M. brasiliensis, M. elaeagnoides, M. petroniana, and M. pohliana.

Melastomataceae is a tropical family of 4500–5000 species divided into nine tribes. The largest tribe, Miconieae, is composed of approximately 2200 species in 30 genera and is found exclusively in the Neotropics. Previous phylogenetic analyses of the Miconieae have suggested that many of the genera are derived from a paraphyletic Miconia. However, these analyses only included six species of the large genus Leandra, so its phylogenetic affinities remained unclear. As currently defined Leandra is characterized by acute petals and terminal inflorescences, but some species of Miconia, Clidemia and Ossaea also have these characters. In this study, we present an analysis of nrITS sequence data for a sample of 63 species of Leandra. The genus is clearly resolved as polyphyletic, but some distinct and well-supported clades exist. Some of these partially correspond to sections recognized in the nineteenth century by Cogniaux, or to geographic distribution. The distribution of seed structure characters is better correlated with the phylogeny than traditional characters, such as petal morphology. Seed appendages in Leandra have evolved independently at least four times. © The Willi Hennig Society 2007.

In the Caribbean region, the Melastomataceae are represented by about 450 species (from 28 genera), close to 400 of them endemic. The majority of these endemic species (approximately 330) belong to the tribe Miconieae, a monophyletic group characterized by flowers with inferior or partly inferior ovaries that develop into baccate fruits, stamens with no or only poorly developed connective appendages, and the absence of megastyloids and imbricate bracts at the base of the flowers. A phylogenetic analysis of 460 accessions from 450 species of the tribe Miconieae, including 139 present in the Antilles (103 of these endemic), was performed based on nuclear (nrITS) and plastid (ndhF) DNA sequence data. This analysis shows that most of the Caribbean endemics are the product of five radiation events: (1) a clade containing the Caribbean endemic (or near-endemic) genera Pachyanthus, Calycogonium, Tetrazygia and Charianthus, as well as a few representatives of Miconia and Leandra. (2) The genus Mecranium. (3) The Caribbean species of Miconia section Chaenopleura (which are probably not the sister group of Andean Chaenopleura). (4) The Greater Antillean species of Clidemia and Ossaea (including Sagraea). (5) The Lesser Antillean representatives of Clidemia. Caribbean endemics that are more closely related to mainland species, rather than other Caribbean species are rare, and these often are segregates of widespread continental species. Because of a lack of resolution at the base of several clades, it is currently not possible to determine which mainland groups are the closest relatives of these Caribbean endemics, thus preventing us from establishing unequivocally the geographical origins of these species.

Membrane fusion is the cell's delivery process, enabling its many compartments to receive cargo and machinery for cell growth and intercellular communication. The overall activation energy of the process must be large enough to prevent frequent and nonspecific spontaneous fusion events, yet must be low enough to allow it to be overcome upon demand by specific fusion proteins [such as soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs)]. Remarkably, to the best of our knowledge, the activation energy for spontaneous bilayer fusion has never been measured. Multiple models have been developed and refined to estimate the overall activation energy and its component parts, and they span a very broad range from 20 kBT to 150 kBT, depending on the assumptions. In this study, using a bulk lipid-mixing assay at various temperatures, we report that the activation energy of complete membrane fusion is at the lowest range of these theoretical values. Typical lipid vesicles were found to slowly and spontaneously fully fuse with activation energies of ∼30 kBT Our data demonstrate that the merging of membranes is not nearly as energy consuming as anticipated by many models and is ideally positioned to minimize spontaneous fusion while enabling rapid, SNARE-dependent fusion upon demand.

The family of the Melastomataceae comprises 5,000 species over the world. In French Guiana, 200 species represent this family. The majority of these species have fundamental importance in the ecological environment of secondary forest or disturbed zones of lowland primary rainforest. The architectural model, the inflorescence and the fruit of four species (six taxa) from the genera Leandra Raddi, Miconia Ruiz & Pav. and Ossaea DC. have been studied. This was done to further the understanding of the development of these species and their faculty to cover the ground.

Objectives To determine the diagnostic accuracy of the cardiothoracic ratio on postero-anterior or antero-posterior chest radiographs in predicting left ventricular or right ventricular dysfunction on echocardiography in an inpatient population. Design Retrospective study. Setting Two secondary care hospitals in the United Kingdom. Participants Four hundred consecutive inpatient echocardiograms were screened for inclusion along with chest radiographs (both postero-anterior and antero-posterior). The cardiothoracic ratio was calculated from chest radiographs along with quantitative and qualitative measures of left ventricular or right ventricular dysfunction on echocardiography. Main outcome measures Sensitivity and specificity of cardiothoracic ratio across a range of values to detect moderate/severe left ventricular and/or right ventricular dysfunction on echocardiography. Results Overall, 272 records met inclusion criteria. The prevalence of left ventricular/right ventricular dysfunction on echocardiography was 26% in an inpatient population with high clinical suspicion of cardiac disease referred for echocardiography. Over a range of cardiothoracic ratio values on postero-anterior films, a value of >0.55 yielded the best sensitivity (62.5%) and specificity (76.5%) for diagnosing left ventricular/right ventricular impairment (positive likelihood ratio 2.56), with a positive predictive value of 29.5%. Cardiothoracic ratio on antero-posterior film was not predictive of left ventricular/right ventricular impairment on echocardiography. Conclusions In conclusion, in the context of an acute admission, cardiothoracic ratio measured on postero-anterior or antero-posterior films has limited value in detecting moderate left ventricular and/or right ventricular systolic dysfunction. Previously established absolute values may be unreliable by modern standards.

Development of the cardiovascular system is critically dependent on the ability of endothelial cells (ECs) to reorganize their intracellular actin architecture to facilitate migration, adhesion, and morphogenesis. Nck family cytoskeletal adaptors function as key mediators of actin dynamics in numerous cell types, though their role in EC biology remains largely unexplored. Here, we demonstrate an essential requirement for Nck within ECs. Mouse embryos lacking endothelial Nck1/2 expression develop extensive angiogenic defects that result in lethality at about embryonic day 10. Mutant embryos show immature vascular networks, with decreased vessel branching, aberrant perivascular cell recruitment, and reduced cardiac trabeculation. Strikingly, embryos deficient in endothelial Nck also fail to undergo the endothelial-to-mesenchymal transition (EnMT) required for cardiac valve morphogenesis, with loss of Nck disrupting expression of major EnMT markers, as well as suppressing mesenchymal outgrowth. Furthermore, we show that Nck-null ECs are unable to migrate downstream of vascular endothelial growth factor and angiopoietin-1, and they exhibit profound perturbations in cytoskeletal patterning, with disorganized cellular projections, impaired focal adhesion turnover, and disrupted actin-based signaling. Our collective findings thereby reveal a crucial role for Nck as a master regulator within the endothelium to control actin cytoskeleton organization, vascular network remodeling, and EnMT during cardiovascular development.

Ultrastructural features of tubular–sarcoplasmic (T–SR) triad junctions and measures of cell volume following graded increases of extracellular tonicity were compared under physiological conditions recently shown to produce spontaneous release of intracellularly stored Ca2+ in fully polarized amphibian skeletal muscle fibres. The fibres were fixed using solutions of equivalent tonicities prior to processing for electron microscopy. The resulting anatomical sections demonstrated a partially reversible cell shrinkage corresponding to substantial increases in intracellular solute or ionic strength graded with extracellular tonicity. Serial thin sections through triad structures confirmed the presence of geometrically close but anatomically isolated transverse (T-) tubular and sarcoplasmic reticular (SR) membranes contrary to earlier suggestions for the development of luminal continuities between these structures in hypertonic solutions. They also quantitatively demonstrated accompanying decreases in T–SR distances, increased numbers of sections that showed closely apposed T and SR membranes, tubular luminal swelling and reductions in luminal volume of the junctional SR, all correlated with the imposed increases in extracellular osmolarity. Fully polarized fibres correspondingly showed elementary Ca2+-release events (‘sparks’, in 100 mM-sucrose-Ringer solution), sustained Ca2+ elevations and propagated Ca2+ waves (≥350–500 mM sucrose) following exposure to physiological Ringer solutions of successively greater tonicities. These were absent in hypotonic, isotonic or less strongly hypertonic (∼50 mM sucrose-Ringer) solutions. Yet exposure to hypotonic solutions also disrupted T–SR junctional anatomy. It increased the tubular diameters and T–SR distances and reduced their area of potential contact. The spontaneous release of intracellularly stored Ca2+ thus appears more closely to correlate with the expected changes in intracellular solute strength or a reduction in absolute T–SR distance rather than disruption of an optimal anatomical relationship between T and SR membranes taking place with either increases or decreases in extracellular tonicity.

BACKGROUND: To determine whether the presence of “coarse” fibrillatory waves (Fw) seen on surface ECGs of patients with persistent atrial fibrillation (AF) predict maintenance of sinus rhythm (SR) at 6 weeks after electrical cardioversion (ECV). METHODS: Preprocedure ECGs from 94 consecutive patients with persistent AF scheduled to undergo ECV at a single centre were classified as having coarse Fw (≥0.1 mV) or fine Fw (

Introduction Initiation of reentrant ventricular tachycardia (VT) involves complex interactions between activation (AT) and repolarization times (RT). Recently, an algorithm has been developed to generate a spatial map (designated the re-entry vulnerability index-RVI) from intervals between local ATs and RTs at adjacent points over a multielectrode grid. The algorithm has been shown to accurately identify the region of a macro-reentrant circuit in two animal models (1). The aim of this study was to test the feasibility of RVI mapping in the right ventricle (RV) to aid ablation strategy of reentrant arrhythmias. Methods Patients with Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) (n=10), Brugada Syndrome (BrS) (n=14) and normal heart RV outflow tract (RVOT) VT (n=6) underwent electrophysiological studies and were followed up for 113±21 months post procedure. Unipolar electrograms were recorded from a non-contact array (St Jude Medical) placed in the RVOT and geometry created with the Ensite system. Recordings were made during a programmed electrical stimulation protocol consisting of a 600 ms drive train and S2 extras. ATs and RTs were computed from the unipolar electrograms and the RVI calculated as previously described (1). Minimum 10% of global RVI values corrected for cycle length ( RVI c 10% ) and distance between region of lowest 5% of RVI values and region of earliest activation during VT ( D min ) were computed for each patient. Results Shortest values of RVI, which represent sites of highest susceptibility to re-entry, co-localised with earliest activation point during VT in the 9 patients with ARVC/BrS where VT was initiated (figure 1). In the ARVC patients this corresponded with location of RV scar as seen on MRI. In the 6 patients with normal heart focal VT, regions of lowest RVI did not co-localise with VT origin. Distance between region of lowest RVI and region of earliest activation during VT, D min , was significantly lower in BrS and ARVC than in normal heart VT (Fig 2A). In both ARVC patients D min =0, indicating region of lowest RVI overlapped with region of earliest VT activation. Of the patients with ARVC/BrS, those with inducible VT or clinical VT at follow-up had significantly lower minimum values of RVI c than those without (−61.0±13.8 ms vs −37.1±7.1 ms) (Fig 2B). Patients with normal heart VT had highest values of RVI c (−27.0±11.3 ms). Conclusion An algorithm based on relative local ATs and RTs identifies localised regions of high susceptibility to conduction block and re-entry, with lowest RVI values localising VT origin of reentrant but not focal arrhythmias. This index could be applied to: 1. Risk stratify ARVC/BrS patients to target ICD prophylaxis. 2. Target ablation for reentrant arrhythmias which are difficult to induce or are haemodynamically unstable, without need for arrhythmia initiation. Reference . Child Net al. Heart Rhythm2015;12:1644–1653

The podocyte slit diaphragm is a fundamental component of the glomerular filtration barrier and its function is highly dependent on the maintenance of specialized actin-based projections known as foot processes. In this review, we update the function of key slit diaphragm-associated proteins, and introduce some new players and emerging avenues of research within podocyte biology.Studies using rodent models continue to support the long-held belief that precise regulation of actin dynamics at the slit diaphragm is essential for proper foot process organization. However, it is also becoming increasingly clear that alterations in actin remodeling can significantly contribute to damage in both animal models and human disease. In particular, the importance of signaling via the Rho family of GTPases has been recognized, as well as the requirement for proper localization and turnover of the slit diaphragm.Regulation of the connection between the slit diaphragm and the podocyte actin network requires complex interplay between multiple signaling pathways. New discoveries contribute to an ever-expanding view of the slit diaphragm and serve to create a framework for the development of new therapeutic strategies targeting podocyte function in the future.

Despite the existence of a Black middle class in the United States (U.S.) for at least 100 years, scant research has been conducted on the Black elderly that has not been concerned with the level of their poverty or the incidence of morbidity and mortality among them. This study examined the living conditions and analyzed the determinants of quality of life satisfaction among 59 Black women 75 years and older. The findings indicate that satisfaction with quality of life is significantly associated with belonging to a family and social support network that includes church, as well as maintaining physical health independence and personal safety. These findings hold implications for the design of social work services to the Black middle income elderly as well for future development of public policy that focuses on providing effective help for older Americans in all their diversity.

Objective To quantify the consumption of chocolates in a hospital ward environment. Design Multicentre, prospective, covert observational study. Setting Four wards at three hospitals (where the authors worked) within the United Kingdom. Participants Boxes of Quality Street (Nestlé) and Roses (Cadbury) on the ward and anyone eating these chocolates. Intervention Observers covertly placed two 350 g boxes of Quality Street and Roses chocolates on each ward (eight boxes were used in the study containing a total of 258 individual chocolates). These boxes were kept under continuous covert surveillance, with the time recorded when each chocolate was eaten. Main outcome measure Median survival time of a chocolate. Results 191 out of 258 (74%) chocolates were observed being eaten. The mean total observation period was 254 minutes (95% confidence interval 179 to 329). The median survival time of a chocolate was 51 minutes (39 to 63). The model of chocolate consumption was non-linear, with an initial rapid rate of consumption that slowed with time. An exponential decay model best fitted these findings (model R2=0.844, P

Sudden cardiac death (SCD) following ventricular tachyarrhythmias constitutes an important clinical cause of mortality; 4% of cases may involve ion channel-mediated cellular excitation in structurally normal hearts. Alterations in such processes could disturb action potential conduction, depolarization/ repolarization gradients, or Ca(2+) homeostasis with potential arrhythmogenic consequences. Although SCD may be the first presentation of arrhythmic syndromes, patients may present to the general physician with symptoms of palpitations or hemodynamic compromise, including dizziness, seizure, or syncope, particularly following exertion. In all inherited cardiac death syndromes, first-degree relatives should be referred to a cardiologist and should undergo testing appropriate for the condition. While management of patients at risk of SCD largely centers on risk stratification and, if necessary, insertion of an implantable cardioverter-defibrillator, there are a number of other, pharmacological, treatments being developed. Furthermore, as the genetic basis of these diseases becomes established, genetic testing will form an increasingly important part of diagnosis, and gene-specific therapy is an area under investigation. This article bridges the gap between molecular medicine and clinical practice by reviewing recent developments in the pathophysiological understanding of SCD, and their implications for the management of patients with these complex diseases.

Organisms and cells are divided in different compartments which have their own function but nevertheless need to communicate with one another. This communication relies on intracellular vesicular traffic, in which vesicles bud from a donor compartment and are transported to an acceptor compartment where they fuse and release their content. Thus, membrane fusion is a most important process in living organisms.In vivo, fusion must not occur spontaneously in order to maintain the integrity of the compartments. This is why this process requires a large activation energy that is overcome thanks to the action of multiple proteins. This activation energy probably depends on many parameters such as membrane composition, curvature, surface tension.Even though biological fusion is very complex and involves proteins, the result is the coalescence of both lipid bilayers that constitute the cores of the involved membranes. This is why the activation energy that is necessary to disrupt the leaflet arrangement during lipid bilayer fusion should be similar to that of in vivo membrane fusion. Hence, we established a protocol to experimentally measure the activation energy for phospholipid membrane fusion, in order to approach the biological membrane fusion activation energy. Theoretical studies and simulations predict an activation energy in the range of 40-150 kT. To our knowledge, no experimental measurement has been done yet.In our experimental setup, the frequency of the rare spontaneous fusion events is investigated at various temperatures, which allows determining the activation energy thanks to Arrhenius’ law. We will present our protocol and show the results for DOPC and POPC membranes containing increasing amounts of DOPE, a phospholipid known to promote hemifusion. We will also present results concerning more physiological compositions, mimicking the fusion of the synaptic vesicle with the plasma membrane.

Two major mechanisms have been postulated for the arrhythmogenic tendency observed in Brugada Syndrome (BrS): delays in conduction or increased heterogeneities in repolarization. We use a contact mapping system to directly investigate the interacting roles of these two mechanisms in arrhythmogenesis using a genetic murine model for BrS for the first time. Electrograms were obtained from a multielectrode recording array placed against the left ventricle and right ventricle (RV) of spontaneously beating Langendorff-perfused wild type (WT) and Scn5a+/− mouse hearts. Scn5a+/− hearts showed activation waves arriving at the epicardial surface consistent with slowed conduction, which was exacerbated in the presence of flecainide. Lines of conduction block across the RV resulting from premature ventricular beats led to the formation of reentrant circuits and polymorphic ventricular tachycardia. WT hearts showed an inverse relationship between activation times and activation recovery intervals measured at the epicardial surface, which resulted in synchronicity of repolarization times. In contrast, Scn5a+/− hearts, despite having smaller mean activation recovery intervals, demonstrated a greater heterogeneity compared with WT. Isochronal maps showed that their normal activation recovery interval gradients at the epicardial surface were disrupted, leading to heterogeneity in repolarization times. We thus directly demonstrate the initiation of arrhythmia in the RV of Scn5a+/− hearts. This occurs as a result of the combination of repolarization heterogeneities leading to lines of conduction block and unidirectional conduction, with conduction slowing allowing the formation of reentrant circuits. The repolarization heterogeneities may also be responsible for the changing pattern of block, leading to the polymorphic character of the resulting ventricular tachycardia.

Repolarization Gradients in Brugada Syndrome.Introduction: Brugada syndrome (BrS) is associated with loss of Na+ channel function and increased risks of a ventricular tachycardia exacerbated by flecainide but reduced by quinidine. Previous studies in nongenetic models have implicated both altered conduction times and repolarization gradients in this arrhythmogenicity. We compared activation latencies and spatial differences in action potential recovery between different ventricular regions in a murine Scn5a+/− BrS model, and investigated the effect of flecainide and quinidine upon these. Methods and Results: Langendorff-perfused wild-type and Scn5a+/− hearts were subjected to regular pacing and a combination of programmed electrical stimulation techniques. Monophasic action potentials were recorded from the right (RV) and left ventricular (LV) epicardium and endocardium before and following flecainide (10 μM) or quinidine (5 μM) treatment, and activation latencies measured. Transmural repolarization gradients were then calculated from the difference between neighboring endocardial and epicardial action potential durations (APDs). Scn5a+/− hearts showed decreased RV epicardial APDs, accentuating RV, but not LV, transmural gradients. This correlated with increased arrhythmic tendencies compared with wild-type. Flecainide increased RV transmural gradients, while quinidine decreased them, in line with their respective pro- and antiarrhythmic effects. In contrast, Scna5+/− hearts showed slowed conduction times in both RV and LV, exacerbated not only by flecainide but also by quinidine, in contrast to their differing effects on arrhythmogenesis. Conclusion: We use a murine genetic model of BrS to systematically analyze LV and RV action potential kinetics for the first time. This establishes a key role for accentuated transmural gradients, specifically in the RV, in its arrhythmogenicity. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1153-1159)

We propose nine new synonyms, and five lectotypifications for South American Miconia (Melastomataceae). Miconia paulensis is synonymized under M. cinerascens var. cinerascens ; M.conferta as a synonym of M. inconspicua; Miconia riedelii and M. langsdorffii as a synonym of M. paucidens; M. camposnovaesii and M. coralliocarpa as a synonym of M. pseudonervosa ; and M. hispida, M. regnellii and M. brevipes var. longifolia under M. trianae. We propose lectotypes for M. conferta, M. hispida, M. langsdorffii, M. pseudonervosa, and M. trianae. Resumo São apresentados nove novos sinônimos e cinco lectotipificações para Miconia sul-americanas. Miconia paulensis é sinonimizada sob M. cinerascens var. cinerascens; M. conferta sob M. inconspicua ; M. riedelii e M. langsdorffii sob M. paucidens; Miconia camposnovaesii e M. coralliocarpa sob M. pseudonervosa e M. hispida, M. regnellii e M. brevipes var. longifolia sob M. trianae. São escolhidos lectótipos para M. conferta, M. hispida, M. langsdorffii, M. pseudonervosa e M. trianae.

In this study we investigate ultrafine particle (UFP) fluxes using a first order eddy viscosity turbulence closure Computational Fluid Dynamics (CFD) model and determine the different factors that influence emissions of UFP into the urban boundary layer. Both vertical turbulent fluxes as well as the fluxes due to mean circulatory flow are shown to contribute to the overall ventilation characteristics of street canyons. We then derive a simple parameterised numerical prediction model for canyon top UFP venting which is then compared with tower based micrometeorological flux measurements obtained during the REPARTEE & CityFlux field experiments.

Ultrastructural features of tubular-sarcoplasmic (T-SR) triad junctions and measures of cell volume following graded increases of extracellular tonicity were compared under physiological conditions recently shown to produce spontaneous release of intracellularly stored Ca2+ in fully polarized amphibian skeletal muscle fibres. The fibres were fixed using solutions of equivalent tonicities prior to processing for electron microscopy. The resulting anatomical sections demonstrated a partially reversible cell shrinkage corresponding to substantial increases in intracellular solute or ionic strength graded with extracellular tonicity. Serial thin sections through triad structures confirmed the presence of geometrically close but anatomically isolated transverse (T-) tubular and sarcoplasmic reticular (SR) membranes contrary to earlier suggestions for the development of luminal continuities between these structures in hypertonic solutions. They also quantitatively demonstrated accompanying decreases in T-SR distances, increased numbers of sections that showed closely apposed T and SR membranes, tubular luminal swelling and reductions in luminal volume of the junctional SR, all correlated with the imposed increases in extracellular osmolarity. Fully polarized fibres correspondingly showed elementary Ca(2+)-release events ('sparks', in 100 mM-sucrose-Ringer solution), sustained Ca2+ elevations and propagated Ca2+ waves (or = 350-500 mM sucrose) following exposure to physiological Ringer solutions of successively greater tonicities. These were absent in hypotonic, isotonic or less strongly hypertonic (approximately 50 mM sucrose-Ringer) solutions. Yet exposure to hypotonic solutions also disrupted T-SR junctional anatomy. It increased the tubular diameters and T-SR distances and reduced their area of potential contact. The spontaneous release of intracellularly stored Ca2+ thus appears more closely to correlate with the expected changes in intracellular solute strength or a reduction in absolute T-SR distance rather than disruption of an optimal anatomical relationship between T and SR membranes taking place with either increases or decreases in extracellular tonicity.

A previously well patient aged 20-plus years, underwent laparotomy following abdominal stab injuries. Bowel lacerations were identified and closed. Through a diaphragmatic defect, a small right atrial puncture was noted which was closed with cardiothoracic surgical assistance. No further injuries were identified. The patient was intubated and ventilated and on inotropic support with a blood pressure of 140/40 mm Hg. The patient's blood pressure later dropped to 100/30 mm Hg and plans were made for further abdominal imaging and re-laparatomy. In the meantime, transthoracic echocardiography (TTE) showed good left and right ventricular function and there was no pericardial effusion. However, the echocardiogram suggested severe aortic regurgitation (figure 1A), and there was a suspicious colour Doppler flow signal noted (figure 1B) through which continuous-wave Doppler velocities were recorded (figure 1C). Figure 1 (A) …

A 52-year-old man was found to have a severely dilated aortic root and a Stanford type A dissection on familial screening echocardiography, following diagnosis of a dilated aorta in his son. The dissection required urgent surgical repair. Clinical examination suggested features of Loeys-Dietz syndrome type II, and subsequent demonstration of a mutation in the TGFBR1 gene in the patient and his son confirmed the diagnosis. This article highlights the high prevalence of inherited conditions in dilated aortic root presentations and the importance of family screening and surveillance to allow early surgical intervention.

Nineteenth-century autobiographical narratives have given us a curious perspective into the early manifestations of Latin American writing as well as into Latin America’s emergence from colonial status to nationhood. Sylvia Molloy, in At Face Value, maintains that the autobiographical works of these new nations became a form of historical account, a personalized insertion of the authorial I/(eye) witness in the historical process. Thus, the personal, private history of the individual functions metonymically within the national discourse.2 Travel narratives stemming from the autobiographical impulse of constructing the self through the travel metaphor confront us with a unique perspective into a privileged site of confluence where the individual voice acts (however reluctantly) as a vessel for a dominant ideology.

We thank all respondents for their insightful comments.1 2 We are overwhelmed and humbled that such distinguished people have taken the time to read and critique our data. We acknowledge their comments and criticisms in light of their expertise and apologise for any shortcomings. The paper underwent rigorous peer review and, as part of this, the editorial committee asked us to focus more …

A patient with severely impaired LV systolic function and New York Heart Association Class III symptoms presented with collapse and was found to have non-sustained ventricular tachycardia. The ECG demonstrated sinus rhythm with first-degree atrioventricular (AV) block and a widened QRS complex. On this basis, a cardiac resynchronisation therapy-defibrillator device was implanted. Leads were introduced via the left subclavian vein to the RV apex and right atrial (RA) appendage. Initial active fix parameters were RA—threshold 0.25 V, impedance 513 Ω, P 2.3 mV; dual coil RV—threshold 0.75 V, impedance 513 Ω, R …

Introduction Studies of Brugada Syndrome (BrS) are often limited by the use of pharmacologically modified cellular or tissue preparations. We show that an in vivo murine genetic Scn5a +/− model reproduces the clinical electrocardiographic phenotype, thereby offering more direct modelling of BrS. We then use this model to investigate conduction and repolarization abnormalities associated with this condition. Methods ECGs were obtained from anaesthetised WT and Scn5a +/– mice, before and after administration of flecainide or quinidine. Traces were examined for ventricular arrhythmias, atrioventricular (AV) block and ST elevation. RR, PR, QR and QTc intervals were measured, and dispersions in QRS and QTc calculated from differences between right precordial and limb leads. Results Scn5a+/ − hearts showed ventricular arrhythmias, ST elevation and AV block. All these features were accentuated by flecainide, with mean ST elevation significantly increased from 0.17±0.03 mV to 0.40±0.07 mV (Abstract 001 Figure 1). Although quinidine did not exert ventricular arrhythmic effects in Scn5a +/− hearts, it had variable effects on ST segments and caused significant conduction abnormalities, which may limited its clinical usefulness in the management of BrS. Scn5a +/− hearts showed slightly increased ECG intervals compared to WT but none of these differences reached statistical significance. However, both flecainide and quinidine increased intervals in WT and Scn5a +/− mice, in contrast with discordant effects upon action potential duration found in previous studies. There was increased dispersion in QRS and QTc intervals for Scn5a+/− hearts compared to WT. In the Scn5a+/− hearts, flecainide increased dispersion in both QRS and QTc, whilst quinidine did not increase the dispersion in either (1.50±0.30 ms before drug for QTc to 3.43±0.30 ms with flecainide (p=0.01), and to 1.32±0.38 ms with quinidine (p=0.03) (n=5)) (Abstract 001 Figure 2). These changes directly parallel the respective pro- and anti- arrhythmic effects of flecainide and quinidine experimentally and clinically in BrS. Conclusions We have demonstrated for the first time that a murine genetic BrS model reproduces the human electrocardiographic features, suggesting both conduction and repolarization abnormalities. We also show that whilst the QT interval is not a direct correlate of action potential duration in a specific cardiac region, QT dispersion may offer an indicator of increased transmural repolarization gradients and may be useful in risk stratification of BrS patients.

Background Primary foci of necrobacillosis infection outside the head and neck are uncommon but have been reported in the urogenital or gastrointestinal tracts. Reports of infection with Solobacterium moorei are rare. Case presentation A 37-year-old male intravenous drug user was admitted with pain in his right groin, fever, rigors and vomiting following a recent injection into the right femoral vein. Admission blood cultures grew Fusobacterium nucleatum, Solobacterium moorei and Bacteroides ureolyticus. The patient was successfully treated with intravenous penicillin and metronidazole. Conclusion This case report describes an unusual case of femoral thrombophlebitis with septic pulmonary embolism associated with anaerobic organisms in a groin abscess. Solobacterium moorei, though rarely described, may also have clinically significant pathogenic potential.

Thirty Neotropical Miconia Ruiz & Pavon taxa described by Naudin and available in BR or P have been lectotypified: M. alternans Naudin, M. amygdalina Naudin, M. anceps Naudin, M. axilliflora Naudin, M. brachystyla Naudin, M. bracteolaris Naudin, M. claussenii Naudin, M. fothergilla (DC.) Naudin var. gracilipes Naudin, M. impetiolaris (Swartz) D. Don var. pandurifolia Naudin, M. lucida Naudin, M. melanodendron Naudin, M. molybdea Naudin, M. myriocarpa Naudin, M. myrtillifolia Naudin, M. obovalis Naudin, M. otodesma Naudin, M. plukenetii Naudin, M. proteoides A. Saint-Hilaire & Naudin, M. rhamnoidea Naudin, M. rhytidophylla Naudin, M. riedelii Naudin, M. rivoeriae Naudin, M. stellifera Naudin, M. stipularis Naudin, M. tentaculifera Naudin, M. tococoides Naudin, M. versicolor Naudin, M. verticilliflora Steudel ex Naudin, Octomeris macrodon Naudin, and Staphidium triste Richard ex Naudin.

It can be daunting to be called as a medical witness months or even years after you treated the patient (usually after an alleged assault or accident). Here are some tips. You will receive a notification letter that you are a witness at a hearing, telling you the following.