The fractional shortening-velocity ratio: Validation of a new echocardiographic doppler method for identifying patients with significant aortic stenosis

AbstractPrevious studies have shown that Doppler echographic methods based on the continuity equation can accurately determine aortic valve area in patients with clinically significant aortic stenosis; nonetheless, methods based on the continuity equation are time-consuming and may not be technically possible in all subsets of patients. Thee purpose of this study was to develop and prospectively evaluate a simpler new noninvasive method for determining aortic valve area. With this new method, aortic valve area is obtained by dividing the percent fractional anteroposterior shortening at the midventriclevel by 4V2, where V is the peak instantaneous Doppler-derived How velocity across the aortic valve.In the fast part of the study, the fractional shortening-velocity ratio was used to examine a group of 25 patients evaluated retrospectively. There was a highly significant linear relation between the fractional shortening-velocity ratio (FSVR) and the aortic valve area (AVA) determined by the Gorlin formula at cardiac catheterization: FSVR = 1.1(AVA) − 0.1 (r = 0.88; significance of slope p < 0.001). Furthermore, a fractional shortening-velocity ratio <1.1 reliably identified all patients with clinically significant aortic stenosis (aortic valve area <1 cm2), whereas a fractional shortening-velocity ratio <0.8 reliably identified all patients with critical aortic stenosis (aortic valve area <0.7 cm2).This new method was then validated by prospectively applying the fractignal shortening-velocity ratio to a group of 44 patients from two separate institutions. This prospective study showed that a fractional shortening-velocity ratio <l.l had a seRR-Jitivity of 90% to 96% and a positive predictive accuracy of 90% to 92% for identifying patients with significant aortic stenosis, whereas a fractional shortening-velocity ratio <0.8 had a sensitivity of 100% and a predictive accuracy of 74% to % for identifying patients with critical aortic stenosis.In summary, the fractional shortening-velocity ratio is a new Doppler echocardiographic method that reliably identifies patients with clinically significant aortic stenosis. The simplicity of this new noninvasive method readily lends itself to routine clinical use

The association of handgrip strength and mortality: What does it tell us and what can we do with it?

© Copyright 2019, Mary Ann Liebert, Inc., publishers 2019. The relationship between grip strength and mortality is often used to underscore the importance of resistance exercise in physical activity guidelines. However, grip strength does not appear to appreciably change following traditional resistance training. Thus, grip strength could be considered reflective of strength independent of resistance exercise. If true, grip strength is not necessarily informing us of the importance of resistance exercise as an adult, but potentially highlighting inherent differences between individuals who are stronger at baseline compared to their weaker counterpart. The purpose of this article is to discuss: (1) potential factors that may influence grip strength and (2) hypothesize strategies that may be able to influence grip strength and ultimately attain a higher baseline level of strength. Although there appears to be a limited ability to augment grip strength as an adult, there may be critical periods during growth/development during which individuals can establish a higher baseline. Establishing a high baseline of strength earlier in life may have long-term implications related to mortality and disease

Microarray and pathway analysis reveals decreased CDC25A and increased CDC42 associated with slow growth of BCL2 overexpressing immortalized breast cell line

Bcl-2 is an anti-apoptotic protein that is frequently overex-pressed in cancer cells but its role in carcinogenesis is not clear. We are interested in how Bcl-2 expression affects non-cancerous breast cells and its role in the cell cycle. We prepared an MCF10A breast epithelial cell line that stably overexpressed Bcl-2. We analyzed the cells by flow cytometry after synchronization, and used cDNA microarrays with quantitative reverse-transcription PCR (qRTPCR) to determine differences in gene expression. The microarray data was subjected to two pathway analysis tools, parametric analysis of gene set enrichment (PAGE) and ingenuity pathway analysis (IPA), and western analysis was carried out to determine the correlation between mRNA and protein levels. The MCF10A/Bcl-2 cells exhibited a slow-growth phenotype compared to control MCF10A/Neo cells that we attributed to a slowing of the G1-S cell cycle transition. A total of 363 genes were differentially expressed by at least two-fold, 307 upregulated and 56 downregulated. PAGE identified 22 significantly changed gene sets. The highest ranked network of genes identified by IPA contained 24 genes. Genes that were chosen for further analysis were confirmed by qRT-PCR, however, the western analysis did not always confirm differential expression of the proteins. Downregulation of the phosphatase CDC25A could solely be responsible for the slow growth pheno-type in MCF10A/Bcl-2 cells. Increased levels of GTPase Cdc42 could be adding to this effect. PAGE and IPA are valuable tools for microarray analysis, but protein expression results do not always follow mRNA expression results. Originally published Cell Cycle, Vol. 7, No. 19, Oct. 200

The Basics of Training for Muscle Size and Strength: A Brief Review on the Theory

The periodization of resistance exercise is often touted as the most effective strategy for optimizing muscle size and strength adaptations. This narrative persists despite a lack of experimental evidence to demonstrate its superiority. In addition, the general adaptation syndrome, which provides the theoretical framework underlying periodization, does not appear to provide a strong physiological rationale that periodization is necessary. Hans Selye conducted a series of rodent studies which used toxic stressors to facilitate the development of the general adaptation syndrome. To our knowledge, normal exercise in humans has never been shown to produce a general adaptation syndrome. We question whether there is any physiological rationale that a periodized training approach would facilitate greater adaptations compared with nonperiodized approaches employing progressive overload. The purpose of this article is to briefly review currently debated topics within strength and conditioning and provide some practical insight regarding the implications these reevaluations of the literature may have for resistance exercise and periodization. In addition, we provide some suggestions for the continued advancement within the field of strength and conditioning

Limb Occlusion Pressure: A Method to Assess Changes in Systolic Blood Pressure

Although often used as a surrogate, comparisons between traditional blood pressure measurements and limb occlusion assessed via hand-held Doppler have yet to be completed. Using limb occlusion pressure as a method of assessing systolic pressure is of interest to those studying the acute effects of blood flow restriction, where the removal of the cuff may alter the physiological response. Purpose: We sought to determine how changes in limb occlusion pressure track with changes in traditional assessments of blood pressure. Basic Procedures: Limb occlusion pressure measured by hand-held Doppler and blood pressure measured by an automatic blood pressure cuff were assessed at rest and following isometric knee extension (post and 5 minutes post). Main Findings: Each individual had a similar dispersion from the mean value for both the limb occlusion pressure measurement and traditional systolic blood pressure measurement [BF10: 0.33; median (95% credible interval): 0.02 (−6.0, 5.9) %]. In response to lower body isometric exercise, blood pressure changed across time. The difference between measurements was small at immediately post and 5 minutes post. The Bayes factors were in the direction of the null but did not exceed the threshold needed to accept the null hypothesis. However, at 5 minutes post, the differences were within the range of practical equivalence (within ± 4.6%). Principal Conclusions: Our findings suggest that changes in limb occlusion pressure measured by hand-held Doppler track similarly to traditional measurements of brachial systolic blood pressure following isometric knee extension exercise

Characterising two-sided quantum correlations beyond entanglement via metric-adjusted f-correlations

We introduce an infinite family of quantifiers of quantum correlations beyond entanglement which vanish on both classical-quantum and quantum-classical states and are in one-to-one correspondence with the metric-adjusted skew informations. The `quantum $f-$correlations' are defined as the maximum metric-adjusted $f-$correlations between pairs of local observables with the same fixed equispaced spectrum. We show that these quantifiers are entanglement monotones when restricted to pure states of qubit-qudit systems. We also evaluate the quantum $f-$correlations in closed form for two-qubit systems and discuss their behaviour under local commutativity preserving channels. We finally provide a physical interpretation for the quantifier corresponding to the average of the Wigner-Yanase-Dyson skew informations.Comment: 20 pages, 1 figure. Published versio

Stringent Constraints on Cosmological Neutrino-Antineutrino Asymmetries from Synchronized Flavor Transformation

We assess a mechanism which can transform neutrino-antineutrino asymmetries between flavors in the early universe, and confirm that such transformation is unavoidable in the near bi-maximal framework emerging for the neutrino mixing matrix. We show that the process is a standard Mikheyev-Smirnov-Wolfenstein flavor transformation dictated by a synchronization of momentum states. We also show that flavor ``equilibration'' is a special feature of maximal mixing, and carefully examine new constraints placed on neutrino asymmetries. In particular, the big bang nucleosynthesis limit on electron neutrino degeneracy xi_e < 0.04 does not apply directly to all flavors, yet confirmation of the large-mixing-angle solution to the solar neutrino problem will eliminate the possibility of degenerate big bang nucleosynthesis.Comment: 11 pages, 6 figures; minor changes to match PRD versio

Invariant Regularization of Anomaly-Free Chiral Theories

We present a generalization of the Frolov-Slavnov invariant regularization scheme for chiral fermion theories in curved spacetimes. local gauge symmetries of the theory, including local Lorentz invariance. The perturbative scheme works for arbitrary representations which satisfy the chiral gauge anomaly and the mixed Lorentz-gauge anomaly cancellation conditions. Anomalous theories on the other hand manifest themselves by having divergent fermion loops which remain unregularized by the scheme. Since the invariant scheme is promoted to also include local Lorentz invariance, spectator fields which do not couple to gravity cannot be, and are not, introduced. Furthermore, the scheme is truly chiral (Weyl) in that all fields, including the regulators, are left-handed; and only the left-handed spin connection is needed. The scheme is, therefore, well suited for the study of the interaction of matter with all four known forces in a completely chiral fashion. In contrast with the vectorlike formulation, the degeneracy between the Adler-Bell-Jackiw current and the fermion number current in the bare action is preserved by the chiral regularization scheme.Comment: 28pgs, LaTeX. Typos corrected. Further remarks on singlet current

CAMKII as a therapeutic target for growth factor-induced retinal and choroidal neovascularisation

This study was supported by grants from the British Heart Foundation (PG/11/99/29207 and PG/11/94/29169), Fight for Sight, UK (1387/88), Health & Social Care R&D Division, Northern Ireland (STL/4748/13) and the Medical Research Council (MC_PC_15026). We would like to thank Gordon Revolta for excellent assistance with colony management and genotyping.Peer reviewedPublisher PD

VEP oscillation solutions to the solar neutrino problem

We study the solar neutrino problem within the framework of a parametrized post-Newtonian formulation for the gravitational interaction of the neutrinos, which incorporates a violation to the equivalence principle (VEP). Using the current data on the rates and the energy spectrum we find two possible oscillation solutions, both for a large mixing angle. One of them involves the MSW effect in matter and the other corresponds to vacuum oscillations. An interesting characteristic of this mechanism is that it predicts a semi-annual variation of the neutrino flux. Our analysis provides new constraints for some VEP parameters.Comment: revtex, 18 pages, 11 figure