Short report: Effect of exercise training on left ventricular mechanics after acute myocardial infarction-an exploratory study.

BACKGROUND: Cardiac rehabilitation (CR) exercise training is beneficial after myocardial infarction (MI). Whilst the peripheral adaptations to training are well defined, little is known regarding the effect on left ventricular (LV) remodelling, particularly LV function. Efficient LV ejection and filling is achieved through deformation and rotation of the myocardium in systole and diastole - LV mechanics. The response of LV mechanics to CR exercise training in MI patients is unknown. METHODS: In this observational exploratory study, 36 (of 40 enrolled) male, MI patients completed either 10-weeks of twice-weekly gym based cardiovascular exercise at 60-80% VO2peak(n=18), or a non-exercise control period (n=18). Cardiopulmonary exercise testing and speckle tracking echocardiography were performed at baseline and 10 weeks. RESULTS: Compared to the non-exercise group, VO2peakimproved with CR exercise training (Difference: +4.28 [95% CI: 1.34 to 7.23] ml.kg-1.min-1, P=0.01). Neither conventional LV structural or functional indices, nor LV global longitudinal strain, significantly changed in either group. In contrast, LV twist and twist velocity decreased in the exercise group and increased in the non-exercise group (Difference: -3.95° [95% CI: -7.92 to 0.03°], P=0.05 and -19.2°.s-1[95% CI: -35.9 to -2.7°.s-1], P=0.02, respectively). CONCLUSION: In MI patients who completed CR exercise training, LV twist and twist velocity decreased, whereas these parameters increased in patients who did not exercise. These preliminary data may indicate reverse LV functional remodelling and improved functional reserve. The assessment of LV twist may serve as an indicator of the therapeutic benefit of CR exercise training and should be investigated in larger trials

High intensity interval training (HIIT) improves resting blood pressure, metabolic (MET) capacity and heart rate reserve without compromising cardiac function in sedentary aging men

Background: This study examined a programme of pre-conditioning exercise with subsequent high intensity interval training (HIIT) on blood pressure, echocardiography, cardiac strain mechanics and maximal metabolic (MET) capacity in sedentary (SED) aging men compared with age matched masters athletes (LEX). Methods: Using a STROBE compliant observational design, 39 aging male participants (SED; n=22, aged 62.7± 5.2 yrs) (LEX; n = 17, aged= 61.1 ± 5.4 yrs) were recruited to a study that necessitated three distinct assessment phases; enrolment (Phase A), following pre-conditioning exercise in SED (Phase B), then following 6 weeks of HIIT performed once every five days by both groups before reassessment (Phase C). Hemodynamic, echocardiographic and cardiac strain mechanics were obtained at rest and maximal cardiorespiratory and chronotropic responses were obtained at each measurement phase. Results: The training intervention improved systolic, mean arterial blood pressure, rate pressure product and heart rate reserve (each P b 0.05) in SED and increased MET capacity in both SED and LEX (P b 0.01) which was amplified by HIIT. Echocardiography and cardiac strain measures were unremarkable apart from trivial increase to intra-ventricular septum diastole (IVSd) (P b 0.05) and decrease to left ventricular internal dimension diastole (LVId) (P b 0.05) in LEX following HIIT. Conclusions: A programme of preconditioning exercise with HIIT induces clinically relevant improvements in blood pressure, rate pressure product and encourages recovery of heart rate reserve in SED, while improving maximal MET capacity in both SED and LEX without inducing any pathological cardiovascular remodeling. These data add to the emerging repute of HIIT as a safe and promising exercise prescription to improve cardiovascular function and metabolic capacity in sedentary aging

Relationship between cardiac deformation parameters measured by cardiovascular magnetic resonance and aerobic fitness in endurance athletes

Background: Athletic training leads to remodelling of both left and right ventricles with increased myocardial mass and cavity dilatation. Whether changes in cardiac strain parameters occur in response to training is less well established. In this study we investigated the relationship in trained athletes between cardiovascular magnetic resonance (CMR) derived strain parameters of cardiac function and fitness. Methods: 35 endurance athletes and 35 age and sex matched controls underwent CMR at 3.0T including cine imaging in multiple planes and tissue tagging by spatial modulation of magnetization (SPAMM). CMR data were analysed quantitatively reporting circumferential strain and torsion from tagged images and left and right ventricular longitudinal strain from feature tracking of cine images. Athletes performed a maximal ramp-incremental exercise test to determine the lactate threshold (LT) and maximal oxygen uptake (V̇O2max). Results: LV circumferential strain at all levels, LV twist and torsion, LV late diastolic longitudinal strain rate, RV peak longitudinal strain and RV early and late diastolic longitudinal strain rate were all lower in athletes than controls. On multivariable linear regression only LV torsion (beta=-0.37, P=0.03) had a significant association with LT. Only RV longitudinal late diastolic strain rate (beta=-0.35, P=0.03) had a significant association with V̇O2max. Conclusions: This cohort of endurance athletes had lower LV circumferential strain, LV torsion and biventricular diastolic strain rates than controls. Increased LT, which is a major determinant of performance in endurance athletes, was associated with decreased LV torsion. Further work is needed to understand the mechanisms by which this occurs

Preliminary Findings of a Randomized Trial of Non-Pharmaceutical Interventions to Prevent Influenza Transmission in Households

Background: There are sparse data on whether non-pharmaceutical interventions can reduce the spread of influenza. We implemented a study of the feasibility and efficacy of face masks and hand hygiene to reduce influenza transmission among Hong Kong household members. Methodology/Principal Findings: We conducted a cluster randomized controlled trial of households (composed of at least 3 members) where an index subject presented with influenza-like-illness of <48 hours duration. After influenza was confirmed in an index case by the QuickVue Influenza A+B rapid test, the household of the index subject was randomised to 1) control or 2) surgical face masks or 3) hand hygiene. Households were visited within 36 hours, and 3, 6 and 9 days later. Nose and throat swabs were collected from index subjects and all household contact at each home visit and tested by viral culture. The primary outcome measure was laboratory culture confirmed influenza in a household contact; the secondary outcome was clinically diagnosed influenza (by self-reported symptoms). We randomized 198 households and completed follow up home visits in 128; the index cases in 122 of those households had laboratory-confirmed influenza. There were 21 household contacts with laboratory confirmed influenza corresponding to a secondary attack ratio of 6%. Clinical secondary attack ratios varied from 5% to 18% depending on case definitions. The laboratory-based or clinical secondary attack ratios old not significantly differ across the intervention arms. Adherence to interventions was variable. Conclusions/Significance: The secondary attack ratios were lower than anticipated, and lower than reported in other countries, perhaps due to differing patterns of susceptibility, lack of significant antigenic drift in circulating influenza virus strains recently, and/or issues related to the symptomatic recruitment design. Lessons learn from this pilot have informed changes for the main study in 2008.published_or_final_versio

Defining the Conformational Features of Anchorless, Poorly Neuroinvasive Prions

Infectious prions cause diverse clinical signs and form an extraordinary range of structures, from amorphous aggregates to fibrils. How the conformation of a prion dictates the disease phenotype remains unclear. Mice expressing GPI-anchorless or GPI-anchored prion protein exposed to the same infectious prion develop fibrillar or nonfibrillar aggregates, respectively, and show a striking divergence in the disease pathogenesis. To better understand how a prion's physical properties govern the pathogenesis, infectious anchorless prions were passaged in mice expressing anchorless prion protein and the resulting prions were biochemically characterized. Serial passage of anchorless prions led to a significant decrease in the incubation period to terminal disease and altered the biochemical properties, consistent with a transmission barrier effect. After an intraperitoneal exposure, anchorless prions were only weakly neuroinvasive, as prion plaques rarely occurred in the brain yet were abundant in extracerebral sites such as heart and adipose tissue. Anchorless prions consistently showed very high stability in chaotropes or when heated in SDS, and were highly resistant to enzyme digestion. Consistent with the results in mice, anchorless prions from a human patient were also highly stable in chaotropes. These findings reveal that anchorless prions consist of fibrillar and highly stable conformers. The additional finding from our group and others that both anchorless and anchored prion fibrils are poorly neuroinvasive strengthens the hypothesis that a fibrillar prion structure impedes efficient CNS invasion

Expression of Genes Encoding Multi-Transmembrane Proteins in Specific Primate Taste Cell Populations

BACKGROUND: Using fungiform (FG) and circumvallate (CV) taste buds isolated by laser capture microdissection and analyzed using gene arrays, we previously constructed a comprehensive database of gene expression in primates, which revealed over 2,300 taste bud-associated genes. Bioinformatics analyses identified hundreds of genes predicted to encode multi-transmembrane domain proteins with no previous association with taste function. A first step in elucidating the roles these gene products play in gustation is to identify the specific taste cell types in which they are expressed. METHODOLOGY/PRINCIPAL FINDINGS: Using double label in situ hybridization analyses, we identified seven new genes expressed in specific taste cell types, including sweet, bitter, and umami cells (TRPM5-positive), sour cells (PKD2L1-positive), as well as other taste cell populations. Transmembrane protein 44 (TMEM44), a protein with seven predicted transmembrane domains with no homology to GPCRs, is expressed in a TRPM5-negative and PKD2L1-negative population that is enriched in the bottom portion of taste buds and may represent developmentally immature taste cells. Calcium homeostasis modulator 1 (CALHM1), a component of a novel calcium channel, along with family members CALHM2 and CALHM3; multiple C2 domains; transmembrane 1 (MCTP1), a calcium-binding transmembrane protein; and anoctamin 7 (ANO7), a member of the recently identified calcium-gated chloride channel family, are all expressed in TRPM5 cells. These proteins may modulate and effect calcium signalling stemming from sweet, bitter, and umami receptor activation. Synaptic vesicle glycoprotein 2B (SV2B), a regulator of synaptic vesicle exocytosis, is expressed in PKD2L1 cells, suggesting that this taste cell population transmits tastant information to gustatory afferent nerve fibers via exocytic neurotransmitter release. CONCLUSIONS/SIGNIFICANCE: Identification of genes encoding multi-transmembrane domain proteins expressed in primate taste buds provides new insights into the processes of taste cell development, signal transduction, and information coding. Discrete taste cell populations exhibit highly specific gene expression patterns, supporting a model whereby each mature taste receptor cell is responsible for sensing, transmitting, and coding a specific taste quality

The Sirtuin Family Members SIRT1, SIRT3 and SIRT6: Their Role In Vascular Biology and Atherogenesis

The sirtuins, silent mating-type information regulation 2 (SIRTs), are a family of nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylases with important roles in regulating energy metabolism and senescence. Activation of SIRTs appears to have beneficial effects on lipid metabolism and antioxidants, prompting investigation of the roles of these proteins in atherogenesis. Although clinical data are currently limited, the availability and safety of SIRT activators such as metformin and resveratrol provide an excellent opportunity to conduct research to better understand the role of SIRTs in human atherosclerosis. Encouraging observations from preclinical studies necessitate rigorous large, prospective, randomized clinical trials to determine the roles of SIRT activators on the progression of atherosclerosis and ultimately on cardiac outcomes, such as myocardial infarction and mortality

CfP: Doktoranden- bzw. Nachwuchsseminar für Cistercienserforschung, 16.–18. Januar 2020, Heiligenkreuz

Veranstaltungsort: Philosophisch-Theologische Hochschule Benedikt XVI. Heiligenkreuz Veranstalter: Europainstitut für Cistercienserforschung der Philosophisch-Theologischen Hochschule Benedikt XVI. in Heiligenkreuz (Prof. P. Alkuin Schachenmayr); Forum Mittelalter der Universität Regensburg (Prof. Jörg Oberste) Datum: 16. bis 18. Januar 2020 Bewerbungsschluss: 24. Dezember 2019 Die Veranstaltung möchte laufende Studien zum Zisterzienserorden in fächer- und epochenübergreifender Perspektive d..

A Test of Modified Indium Seal of a Window at Liquid Helium Temperature(Physics)

A modified version of an indium seal with a very small loss area, in which pure In solder is used instead of pure In wire, has been tried for a glass window of 20 mm in diameter. It has turned out that this seal is vacuum tight against the liquid helium at 4.2K. A seal of a 10 mmφ sapphire window with STYCAST 2, 850 GT was also successfully tested at 4.2 K

n Studie van die faktore wat die akkuraatheid van vogbepaling van Pinus patula-droogkamermonsters beinvloed en 'n kritiese ontleding van versnelde tegnieke van vogbepaling van droogkamervragte

Skripsie (M. Sc.) -- Universiteit van Stellenbosch, 1975.Full text to be digitised and attached to bibliographic record