Non-invasive cardiac electrophysiological indices in soccer players with mitral valve prolapse.

BACKGROUND: Cardiac disorders constitute the most common causes of sudden cardiac death (SCD) and mitral valve prolapse (MVP) is one of the cardiac structural causes in young populations. The aim of this study was to evaluate some reliable non-invasive electrophysiological variables of SCD in young athletes with mild or moderate MVP and to compare them with their cardiorespiratory adaptations. DESIGN: The study population comprised of 40 amateur male soccer players, who were equally subdivided into those with (group A, aged 20.4+/-4.5 years) and without (group B, 18.4+/-2.4 years) MVP and 20 healthy age-matched sedentary individuals (group C). METHODS: All subjects underwent echo study for left ventricular mass index (LVMI) estimation, treadmill spiro-ergometric test for maximal oxygen uptake (VO2max) measurement and continuous ambulatory 24-h ECG recordings for arrhythmias detection and heart rate variability (HRV) analysis. Furthermore, groups A and B were also submitted to signal-averaged electrocardiogram for late potentials (LP) assessment and to submaximal exercise test for T-wave alternans (TWA) detection. RESULTS: Maximal oxygen uptake, LVMI and HRV index were enhanced in all athletes compared to group C (P<0.05). Resting QTc interval was significantly prolonged only in group B (by 3.7%) compared to C (P<0.05), whereas no significant difference was found between A and B. No positive LP or TWA were observed in all subjects. Significant correlation was found only between HRV index and VO2max in all groups. CONCLUSIONS: Athletes with mild or moderate MVP do not present any significant difference in non-invasive cardiac electrophysiological indices as well as in cardiorespiratory performance, compared to healthy ones. It seems that long-term exercise induced adaptations overlap any cardiac autonomic disorders in cases of mild-to-moderate MVP severity.     

The MPO Study: just a European HEMO Study or something very different?

Although results from observational and epidemiological studies suggested a survival benefit associated with high-flux hemodialysis, conclusive evidence from prospective randomized clinical trials has been lacking. Both the HEMO Study in the USA and the Membrane Permeability Outcome Study (MPO Study) in Europe are randomized studies investigating the effect of high- and low-flux hemodialysis on patient outcomes, even though there were some significant differences in the design of the two studies. An earlier randomized clinical trial could not show differences on patient survival between patient groups being treated with membranes of different material and permeability, but this trial was not designed specifically to examine this particular endpoint. Based on these previous experiences, the MPO Study addressed a hemodialysis patient population which was considered to be more susceptible to the intervention with high-flux dialysis. To identify these patients with an elevated risk, low serum albumin levels were chosen as an indicator; low serum albumin is associated with malnutrition, inflammation, atherosclerosis, and with increased risk of morbidity and mortality. Together with low serum albumin, patients had to be new to dialysis to be selected for the MPO Study. These particular considerations on patient selection, together with additional methodological refinements in the study design allow the conclusion that the MPO Study is valid on its own rather than being a European version of the HEMO Study.     

Postsynaptic N-methyl-D-aspartate receptor function requires alpha-neurexins

Alpha-neurexins are neuron-specific cell-surface molecules that are essential for the functional organization of presynaptic Ca2+ channels and release sites. We have now examined postsynaptic glutamate receptor function in alpha-neurexin knockout (KO) mice by using whole-cell recordings in cultured neocortical slices. Unexpectedly, we find that alpha-neurexins are required for normal activity of N-methyl-D-aspartate (NMDA)- but not alpha-amino-3-hydroxy-5-methyl-4-isoxyzolepropionic acid (AMPA)-type glutamate receptors. In alpha-neurexin-deficient mice, the ratio of NMDA- to AMPA-receptor currents, recorded as evoked synaptic responses, was diminished approximately 50%. Furthermore, the NMDA-receptor-dependent component of spontaneous synaptic miniature responses was reduced approximately 50%, whereas the AMPA-receptor-dependent component was unaffected. No alterations in the levels of NMDA- or AMPA-receptor proteins were detected. These results suggest that alpha-neurexins are required to maintain normal postsynaptic NMDA-receptor function. The decrease in NMDA-receptor activity in alpha-neurexin-deficient synapses could be due to a transsynaptic effect on the postsynaptic neuron (i.e., alpha-neurexins on the presynaptic inputs guide postsynaptic NMDA-receptor function) or to a cell-autonomous postsynaptic effect of alpha-neurexins on NMDA-receptor activity. To distinguish between these two possibilities, we cocultured WT GFP-labeled neurons with neocortical slices from alpha-neurexin-deficient or control mice. No difference was found between WT neurons innervated by inputs that contained or lacked alpha-neurexins, indicating that the absence of presynaptic alpha-neurexins alone does not depress postsynaptic NMDA-receptor function. Our data suggest that, in addition to the previously described presynaptic impairments, loss of alpha-neurexins induces postsynaptic changes by a cell-autonomous mechanism.     

Increased Ca 2+-sensitivity of myofibrillar tension in heart failure and its functional implication

In human failing myocardium, an increased Ca ²⁺-sensitivity of myofilament tension development has been described in Triton X skinned cardiac myocytes compared to cardiomyocytes obtained from non-failing human donor hearts. The present study aimed to investigate whether there are functional implications of the increased Ca ²⁺-sensitivity in heart failure and whether alterations of myofilament function are already obvious at earlier stages of heart failure, such as in cardiac hypertrophy or whether alterations of the intracellular Ca ²⁺-homeostasis are able to induce alterations in myofilament function. Ca ²⁺-activated tension development was measured in Triton X-skinned fibers from human failing and non-failing myocardium. Ca ²⁺-sensitivity of myofilament tension development was significantly shifted to the left in human failing myocardium. Plots of diastolic free Ca ²⁺ versus diastolic tension development showed that in a range of similar diastolic Ca ²⁺-concentrations, diastolic tension was significantly enhanced in the failing hearts. The Ca ²⁺/tension relationship was shifted to the right in Triton X-skinned fiber preparations from transgenic renin overexpressing rats (TG(mREN2)27), shown to have concentric hypertrophy. In addition, the Ca ²⁺/tension relationship was unchanged in phospholamban knock-out mice with an increased systolic Ca ²⁺ (and enhanced diastolic Ca ²⁺-load). It is concluded that the increased Ca ²⁺-sensitivity of myofilament tension observed in single cardiomyocytes from failing human myocardium may be a phenomenon also present in multicellular preparations and may contribute to the diastolic dysfunction observed in human heart failure. Alterations of myofilament function occur at very early stages of heart failure and may be species dependent, or dependent on intracellular free Ca ²⁺-levels.     

Phospholamban gene ablation improves calcium transients but not cardiac function in a heart failure model

Decreased amplitude and slower kinetics of cardiomyocyte intracellular calcium (Ca(i)(2+)) transients may underlie the diminished cardiac function observed in heart failure. These alterations occur in humans and animals with heart failure, including the TNF1.6 mouse model, in which heart failure arises from cardiac-specific overexpression of tumor necrosis factor alpha (TNF alpha). OBJECTIVE: Since ablation of phospholamban expression (PLBKO) removes inhibition of the sarcoplasmic reticulum (SR) Ca(2+) pump, enhances SR Ca(2+) uptake and increases contractility, we assessed whether ablation of phospholamban expression could improve cardiac function, limit remodeling, and improve survival in the TNF1.6 model of heart failure. METHODS: We bred PLBKO with TNF1.6 mice and characterized the progeny for survival, cardiac function (echocardiography), cardiac remodeling (hypertrophy, dilation, fibrosis), and Ca(2+)(i) transients and contractile function of isolated cardiomyocytes. RESULTS: PLB ablation did not improve survival, cardiac function, or limit cardiac chamber dilation and hypertrophy in TNF1.6 mice (TKO mice). However, contractile function and Ca(2+)(i) transients (amplitude and kinetics) of isolated TKO cardiomyocytes were markedly enhanced. This discordance between unimproved cardiac function, and enhanced Ca(2+)(i) cycling and cardiomyocyte contractile parameters may arise from a continued overexpression of collagen and decreased expression of gap junction proteins (connexin 43) in response to chronic TNF alpha stimulation. CONCLUSIONS: Enhancement of intrinsic cardiomyocyte Ca(2+)(i) cycling and contractile function may not be sufficient to overcome several parallel pathophysiologic processes present in the failing heart.     

Breakfast cereal is associated with a lower prevalence of obesity among 10-12-year-old children: the PANACEA study

Background and aimEating behaviours and obesity status among children have already been evaluated in several studies, with conflicting results. The aim of this study is to assess the correlation of breakfast cereal with childhood obesity.Methods and resultsA representative sample of 700 children (323 male) selected from 18 schools located in Athens greater area were enrolled. Children and their parents completed questionnaires that evaluated dietary habits and physical activity. We also retrieved information about the type of breakfast most frequently consumed. Height and weight of the children was measured and body mass index (BMI) was calculated. Simple and multiple logistic regression methods were used in order to determine the relationship between cereal intake for breakfast and obesity.Some boys (8.6%) and girls (9.0%) were obese, whereas 33.9% of boys and 22.1% of girls were overweight. For boys, the adjusted odds ratio for breakfast cereal intake for being overweight or obese was 0.54 (95% confidence interval (CI): 0.45–1.29), while for girls it was 0.41 (95% CI: 0.21–0.79). Moreover, the odds ratio of overweight/obesity for boys who ate daily breakfast was 0.51 (95% CI: 0.25–1.05), and for girls was 0.27 (95% CI: 0.12–0.64), adjusted for physical activity and other potential confounders.ConclusionThese data provide evidence that breakfast cereal as a most frequent choice, and daily consumption of breakfast, are inversely associated with the prevalence of overweight or obesity in 10–12-year-old children.     

Key Characteristics of Rehabilitation Quality Improvement Publications: Scoping Review From 2010 to 2016

Objective

To characterize the peer-reviewed quality improvement (QI) literature in rehabilitation.

Effects of endoscopic variceal treatment on oesophageal function: a prospective, randomized study

AIM : Endoscopic methods are currently the most widely used techniques for the treatment of bleeding oesophageal varices (BOV). However, a number of complications may limit their usefulness. We conducted a prospective, randomized comparison of variceal ligation versus sclerotherapy in cirrhotics after the control of variceal haemorrhage to study the relative short-term risks of these two procedures with respect to oesophageal motility and gastro-oesophageal reflux. METHODS : Seventy-three patients with established cirrhosis and an episode of variceal bleeding controlled by one session of endoscopic therapy were randomized to treatment with sclerotherapy or ligation until variceal eradication. In 60 of these patients, oesophageal manometry and 24-h intra-oesophageal pH monitoring were performed at inclusion and 1 month after variceal eradication. RESULTS : After variceal eradication with sclerotherapy, peristaltic wave amplitude decreased from 76.2 +/- 14.7 mmHg to 61.6 +/- 17.7 mmHg (P = 0.0001), simultaneous contractions increased from 0% to 37.9% (P = 0.0008), and the percentage of time with pH < 4 increased from 1.60 +/- 0.25 to 4.91 +/- 1.16% in channel 1 (P = 0.0002) and from 1.82 +/- 0.27 to 5.69 +/- 1.37% in channel 2 (P = 0.0006). In contrast, the above parameters were not disturbed with ligation. CONCLUSION : Our data define the advantages of ligation over sclerotherapy with respect to post-treatment oesophageal dysmotility and associated gastro-oesophageal reflux.     

Management of congenital vascular malformations of the limbs

Congenital vascular malformations (CVMs) of the limbs are rare lesions of uncertain etiology with structural disorders of the vascular system, nondegenerative and noninflammatory in origin, which occur during embryologic development. They affect one or more systems, commonly coexist with other malformations, and create a polymorphy, and their classification and radical cure are questionable.Surgical treatment, where indicated, presupposes morphological and hemodynamic evaluation of each case, knowledge of the pathophysiology, and highly specialized surgical ability.In this series of 31 patients with CVMs of the limbs, 12 arteriovenous (av) fistulae, 8 Klippel-Trenaunay syndromes, 1 Kasabach-Merritt syndrome, and 10 pure venous angiomata were studied. Ten of the 12 av fistulae were managed operatively, and the other CVMs were managed mainly conservatively.Congenital av fistulae require surgical therapy because of their serious systemic and local complications. Surgical options include division and ligation of the fistula, skeletonization of the feeding artery, or resection of the fistula and ligation of the feeding vessels. In the other groups of CVMs nonoperative management offers the best results and consists of elastic support of the limb, appropriate profession selection, body weight control, orthopedic shoes, avoidance of oral contraceptives in women, and rarely, conservative operations on the veins of compression sclerotherapy.In 6 of the 10 limbs with av fistulae operated on the results remain good at mean follow-up of 7.2 years, but 4 of the remaining recurred (rate 40%), and in 2 of the recurrences reoperation has been planned for further reduction of the shunt. In the CVMs other than av fistulae, the condition of the patients treated with conservative measures only has stabilized, whereas in the ones who had surgery, compression sclerotherapy, or laser therapy the results were unsatisfactory.