bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Atrioventricular Compliance on Clinical Outcome of Patients Undergoing Successful Percutaneous Balloon Mitral Valvuloplasty
Authors: Mahfouz Ragab A , Elawady Waled , Hossein Ekhlas , Yosri Ahmad 
Published: June 2013

ObjectiveWe aimed to assess the impact of atrioventricular compliance (Cn) on the clinical outcome, after successful percutaneous balloon mitral valvuloplasty (PBMV).Methods and ResultsUsing Doppler echocardiography Cn was estimated from the equation that has been previously validated. Mitral valve area (MVA), tricuspid annular plane systolic excursion (TAPSE), pulmonary artery pressure (PAP), and degree of tricuspid regurgitation (TR) severity were evaluated before, immediately, and every 6 months with a median duration of 32 months after successful PBMV in 150 consecutive patients. An immediate drop in PAP and significant improvement of right ventricle (RV) function was observed after PBMV. Cn was negatively correlated pre and post‐PBMV, with the degree of pulmonary artery systolic pressure (PAPs), TAPSE (P < 0.0001). Patients with Cn ≤ 3.75 mL/mmHg had higher incidence of adverse outcome (developing atrial fibrillation [AF], worsening RV function, progressive left atrial dilation, and redo intervention). Multivariate regression analysis showed that the Cn was the strongest independent predictor of PAPs and RV function before and after successful PBMV (P < 0.0001). Cn ≤ 3.75 mL/mmHg was the cutoff value for prediction of clinical events at follow‐up.ConclusionsAtrioventricular compliance was significantly lower in patients with mitral stenosis (MS) with unfavorable outcome after successful PBMV. The RV function and pulmonary hypertension were significantly correlated with the degree of Cn. This suggests a significant role of Cn in patients with MS, providing a good insight for intervention and utilizing Cn as a noninvasive hemodynamic index for risk stratification and proper timing for intervention in patients with MS.
Evaluation of Correlation between Aortic Elastic Parameters and Atrial Electromechanical Abnormalities in Hypertensive Patients
Authors: Sen Omer , Abali Gulcan , Yavuz Bunyamin , Batur Mutafa Kemal 
Published: June 2013

ObjectivesArterial hypertension leads to instability and heterogeneity in atrial conduction by these hemodynamic and morphological changes in heart and aorta. These changes can be evaluated by transthoracic echocardiography. The aim of this study was to evaluate the correlation of aortic elastic parameters and atrial electromechanical delay (AEMD) parameters in patients with hypertension.MethodsEighty‐one hypertensive patients and 55 control subjects were included in the study. All subjects underwent transthoracic echocardiography for detecting aortic elastic parameters and AEMD parameters.ResultsThere was no difference between HT and control groups regarding age and gender. Aortic strain (8.1 ± 4.3% vs. 10.3 ± 5.1%, P = 0.008) and aortic distensibility (0.35 ± 0.18 cm2/dyn vs. 0.45 ± 0.23 cm2/dyn, P = 0.003) were decreased in hypertensive patients than in controls. Intra‐left AEMD (25.5 ± 7.3 vs. 21.8 ± 9.2 P < 0.009) was significantly higher in hypertensive patients compared to control subjects. No statistically significant difference was found in intra‐right AEMD and inter‐AEMD between the groups. There was a positive significant moderate correlation between aortic strain and intra‐left AEMD (r = 0.501, P < 0.001).ConclusionsThis study demonstrated that intra‐left AEMD was increased in hypertensive patients and aortic elastic parameters was correlated with intra‐left AEMD. These findings may be related to similar structural and functional changes in heart and aorta in hypertension.
Age‐ and Gender‐Dependent Left Ventricular Remodeling
Authors: Gebhard Catherine , Stähli Barbara E. , Gebhard Caroline E. , Tasnady Hanna , Zihler Deborah , Wischnewsky Manfred B. , Jenni Rolf , Tanner Felix C. 
Published: June 2013

BackgroundThe effect of age and gender on left ventricular (LV) size, muscle mass, and systolic function as determined by two‐dimensional echocardiography has not yet been investigated in a large population.MethodsNormal transthoracic two‐dimensional echocardiography studies of 5307 subjects (47% males) performed between March 1990 and December 2011 were analyzed. LV end‐diastolic volume index (LVEDVI), LV muscle mass index (LVMMI), LV ejection fraction (LVEF), and LV fractional shortening (LVFS) were compared in different age groups.ResultsLVMMI increased in females from 66.4 ± 1.3 g/m2 (7–20 years) to 76.3 ± 0.9 g/m2 (60–80 years; P < 0.0001) and in males from 81.9 ± 1.7 g/m2 (7–20 years) to 94.6 ± 1.3 g/m2 (60–80 years; P < 0.0001). LVEDVI decreased in females from 49.8 ± 0.9 mL/m2 (7–20 years) to 42.8 ± 0.6 mL/m2 (60–80 years; P < 0.0001) and in males from 56.6 ± 0.8 mL/m2 (7–20 years) to 49.0 ± 0.7 mL/m2 (60–80 years; P < 0.0001). A significant increase in LVEF was observed with age (P < 0.0001 for both genders), but it was more pronounced in females (62 ± 0.5% [age 7–20 years] vs. 65 ± 0.3% [age 60–80 years]) than in males (62 ± 0.5% [age 7–20 years] vs. 64 ± 0.3% [age 60–80 years]). Similarly, LVFS increased in females from 37.7 ± 0.5% (7–20 years) to 42.4 ± 0.4% (60–80 years; P < 0.001) and in males from 37.3 ± 0.5% (7–20 years) to 39.4 ± 0.5% (60–80 years; P < 0.001).ConclusionsLVEF, LVFS, and LVMMI increase with advancing age, in particular in females. In contrast, LVEDVI decreases with age. These findings indicate that the LV undergoes a lifelong remodeling.
Altered Mitral Inflow Orifice in Severe Aortic Regurgitation: Real Time Three‐Dimensional Echocardiographic Findings
Authors: Bertrand Philippe B. , Verhaert David , Vandervoort Pieter 
Published: June 2013

Mini‐AbstractWe present the case of a young man with severe eccentric aortic regurgitation, obstructing mitral inflow and provoking an audible Austin Flint murmur at clinical examination. Two‐dimensional color Doppler echocardiography depicts the remarkable mechanical interaction between aortic regurgitant jet and anterior mitral leaflet opening. Three‐dimensional transesophageal echocardiography aids in understanding the geometric and hemodynamic consequences of the regurgitant jet and in the genesis of the Austin Flint murmur. This case accentuates the incremental value of three‐dimensional echocardiography when evaluating valvular pathology, and offers more insight in the interaction between aortic regurgitant flow and mitral leaflet dynamics.
Bleeding Risk in Patients with Esophageal Varices Undergoing Transesophageal Echocardiography
Authors: Pantham Ganesh , Waghray Nisheet , Einstadter Douglas , Finkelhor Robert S. , Mullen Kevin D. 
Published: June 2013

BackgroundBleeding from esophageal varices is a major potential concern during transesophageal echocardiography (TEE) in patients with cirrhosis of the liver. As there are limited data on its risk in these patients, this was retrospectively assessed at our institution.MethodsThe hospital electronic medical record database at our university affiliated teaching hospital was searched for all patients with esophageal varices undergoing TEE from 2000 to 2012 and patient charts were reviewed for procedure‐related bleeding complications.ResultsTwenty‐four patients with esophageal varices were found (18 men, 57 ± 14 years). Nine patients had grade 2 esophageal varices, 15 patients had grade 1 varices, and 12 patients had portal hypertensive gastropathy. Alcoholic liver disease (9) and hepatitis C (8) were the most common etiologies of the cirrhosis with an average MELD score of 15. The most common indication for TEE was for possible endocarditis (15). Medications potentially increasing bleeding risk included warfarin in 2 and aspirin in 7 patients. Twelve patients were taking β‐blockers for portal hypertension. There were no immediate bleeding complications and none of these patients were readmitted with bleeding.ConclusionsTEE can be performed without serious bleeding risk in patients with grade 1 or 2 esophageal varices.
Coronary Flow Reserve and Myocardial Performance Index in Newly Diagnosed Diabetic Patients
Authors: Kalkan Gülhan Yüksel , Gür Mustafa , Şahin Durmuş Yıldıray , Baykan Ahmet Oytun , Elbasan Zafer , Kuloğlu Osman , Kıvrak Ali , Türkoğlu Caner , Arık Osman Ziya , Çayli Murat 
Published: June 2013

BackgroundPatients with diabetes mellitus (DM) are at high risk of left ventricular (LV) dysfunction. A reduction of coronary flow reserve (CFR) has been demonstrated in diabetic patients without coronary artery stenosis. In this study, we investigated the association between LV myocardial diastolic and systolic functions and the CFR in newly diagnosed diabetic patients in the absence of coronary artery disease.MethodWe studied 88 patients (mean age 49 ± 10 years) with newly diagnosed DM and 40 healthy control subjects (mean age 50 ± 9 years). All subjects underwent transthoracic echocardiography. The myocardial performance index (MPI) was determined by using pulsed‐wave Doppler. The CFR was calculated as the hyperemic to resting coronary diastolic peak velocities ratio.ResultsPatients with diabetes had significantly longer mitral E‐wave deceleration time and higher MPI value than control group (P = 0.023 and P < 0.001, respectively). The mean CFR was lower in diabetic patients compared with controls (P = 0.001). The MPI was significantly correlated with CFR (r = −0.371, P < 0.001), LV ejection fraction (r = −0.274, P = 0.018) E/A ratio (r = −0.244, P = 0.024), and glycosylated hemoglobin (HbA1c) (r = 0.476, P < 0.001). Multivariate regression analysis showed that MPI was independently associated with CFR (β = −0.292, P < 0.0001) and HbA1c level (β = 0.372, P < 0.0001).ConclusionsThe MPI was independently associated with CFR in newly diagnosed diabetic patients. The decrease in CFR may cause LV systolic and diastolic dysfunction in asymptomatic diabetic patients.
Spontaneous Echo Contrast at a Large Inter‐Atrial Septal Aneurysm
Authors: Pratap Pravin , Foster Mariah M. , Labovitz Arthur J. , Chae Sanders H. 
Published: June 2013

Mini‐AbstractA 75‐year‐old woman presented with typical atrial flutter. Prior to ablation, a transesophageal echocardiogram demonstrated significant spontaneous echo contrast (SEC) at the site of a large inter‐Atrial septal aneurysm (ASA). After ablation of the arrhythmia, recovery of her left ventricular function, and 3 months of therapeutic anticoagulation with warfarin, she continued to have significant SEC at the site of her ASA, implicating the ASA as the source for the SEC.
Modulation of presynaptic Ca2+ currents in frog motor nerve terminals by high pressure
Authors: Aviner Ben , Gradwohl Gideon , Moore Homer J. , Grossman Yoram 
Published: June 2013

AbstractPresynaptic Ca2+‐dependent mechanisms have already been implicated in depression of evoked synaptic transmission by high pressure (HP). Therefore, pressure effects on terminal Ca2+ currents were studied in Rana pipiens peripheral motor nerves. The terminal currents, evoked by nerve or direct stimulation, were recorded under the nerve perineurial sheath with a loose macropatch clamp technique. The combined use of Na+ and K+ channel blockers, [Ca2+]o changes, voltage‐dependent Ca2+ channel (VDCC) blocker treatments and HP perturbations revealed two components of presynaptic Ca2+ currents: an early fast Ca2+ current (ICaF), possibly carried by N‐type (CaV2.2) Ca2+ channels, and a late slow Ca2+ current (ICaS), possibly mediated by L‐type (CaV1) Ca2+ channels. HP reduced the amplitude and decreased the maximum (saturation level) of the Ca2+ currents, ICaF being more sensitive to pressure, and may have slightly shifted the voltage dependence. HP also moderately diminished the Na+ action current, which contributed to the depression of VDCC currents. Computer‐based modeling was used to verify the interpretation of the currents and investigate the influence of HP on the presynaptic currents. The direct HP reduction of the VDCC currents and the indirect effect of the action potential decrease are probably the major cause of pressure depression of synaptic release.
Multiple episodes of sodium depletion in the rat: a remodeling of the electrical properties of median preoptic nucleus neurons
Authors: Voisin Aurore N. , Mouginot Didier , Drolet Guy 
Published: June 2013

AbstractIn rat brain, the detection and integration of chemosensory and neural signals are achieved, inter alia, by the median preoptic nucleus (MnPO) during a disturbance of the hydromineral balance. This is allowed through the presence of the sodium (Na+) sensor neurons. Interestingly, enkephalins and mu‐opioid receptors (μ‐ORs) are known for their role in ingestive behaviors and have previously been shown to regulate the excitability of MnPO neurons following a single Na+ depletion. However, little is known about the role of these μ‐ORs in the response enhancement following repeated Na+ challenge. Therefore, we used whole‐cell recordings in acute brain slices to determine neuronal plasticity in the electrical properties of the MnPO Na+ sensor‐specific neuronal population following multiple Na+ depletions. Our results show that the population of Na+ sensor neurons was represented by 80% of MnPO neurons after a single Na+ depletion and was reduced after three Na+ depletions. Interestingly, the subpopulation of Na+ sensors responding to D‐Ala2,N‐MePhe4,Gly‐ol‐enkephalin (DAMGO), a specific μ‐OR agonist, represented 11% of MnPO neurons after a single Na+ depletion and the population doubled after three Na+ depletions. Moreover, Na+ sensor neurons displayed modifications in the discharge pattern distribution and shape of calcium action potentials after three Na+ depletions but these changes did not occur in Na+ sensors responding to DAMGO. Thus, the reinforced μ‐OR functionality in Na+ sensors might take place to control the neuronal hyperexcitability and this plasticity in opioid‐sensitive and Na+ detection MnPO networks might sustain the enhanced salt ingestion induced by repeated exposure to Na+ depletion.
Turnover and availability of soil organic carbon under differentMediterranean land‐uses as estimated by13Cnatural abundance
Authors: Novara A. , Gristina L. , Kuzyakov Y. , Schillaci C. , Laudicina V. A. , La Mantia T. 
Published: June 2013

SummarySoil organic matter (SOM) is an important factor in ecosystem stability and productivity. This is especially the case for Mediterranean soils suffering from the impact of human degradation as well as harsh climatic conditions. We used the carbon (C) exchange resulting fromC3‐C4andC4‐C3vegetation change under field conditions combined with incubations under controlled conditions to evaluate the turnover and availability of soil organicCunder different land‐uses. The 40‐year succession ofHyparrenia hirtaL. (C4photosynthesis) after more than 85 years of olive tree (Olea europaeaL.;C3photosynthesis) growth led to the exchange of 54% of soil organic C fromC3toC4forms. In contrast, 21 years of vine (Vitis viniferaL.) growing afterH. hirtadecreased the organic C content to 57%. Considering this exchange and decrease as well as the periods after the land‐use changes, we calculated the mean residence time (MRT) of soil C of different ages. TheMRTof C under grassland dominated byH. hirtawas about 19 years, but was 180 years under the vineyard. The rates of C accumulation under theH. hirtagrassland were about 0.36 Mg C ha−1 year−1. In contrast, the rates ofClosses after conversion from natural grassland to a vineyard were 1.8 times greater and amounted to 0.65 Mg C ha−1 year−1. We conclude that changes of land use from naturalMediterranean grassland to a vineyard lead to very largeClosses that cannot be compensated for over the same periods.
Noninvasive determination of atrial fibrillation cycle length by atrial colour tissue Doppler imaging in horses
Authors: Decloedt A. , de Clercq D. , van der Vekens N. , Verheyen T. , van Loon G. 
Published: June 2013

SummaryReasons for performing studyAtrial fibrillation cycle length (AFCL) is an indicator of atrial electrical remodelling during atrial fibrillation (AF).ObjectivesTo compare AFCL measured invasively from an intra‐atrial electrogram (AFCLEGM) with AFCL measured noninvasively by atrial colour tissue Doppler imaging (AFCLTDI).Study designProspective descriptive clinical study.MethodsMeasurements were performed in 31 episodes of AF or flutter in 29 horses (588 ± 61 kg bwt, 9 ± 3 years old) admitted for transvenous electrical cardioversion. The AFCLEGM was measured from an intracardiac electrogram using a bipolar sensing/pacing electrode inserted into the right atrium. The AFCLTDI was measured from atrial colour tissue velocity curves in the following 5 regions: 1) left atrial free wall from a right parasternal 4‐chamber view, 2) left atrial free wall from a short‐axis view, 3) left atrial free wall from a left parasternal long‐axis view, 4) interatrial septum, and 5) right atrial dorsal wall near the tuberculum intervenosum. The AFCLEGM and AFCLTDI from the 5 regions were compared using a one‐way repeated‐measures ANOVA with Bonferroni correction for multiple comparisons and calculation of the Bland‐Altman mean bias and limits of agreement of AFCLEGM and AFCLTDI.ResultsThe AFCLEGM was 161 ± 18 ms in 29 AF episodes. Two horses showed atrial flutter and had an AFCLEGM of 244 and 324 ms. The mean bias between AFCLTDI and AFCLEGM ranged from ‐18 to +9 ms depending on the atrial wall region. The AFCLTDI was significantly shorter in the left atrial free wall from the right parasternal 4‐chamber view and short‐axis view than in the other regions (P<0.001).ConclusionsTissue Doppler imaging allows noninvasive measurement of AFCL in horses with AF and is able to identify spatial differences within the equine atria. Atrial fibrillation cycle length is an indicator of atrial electrical remodelling and is an important parameter to study AF pathophysiology or the effect of antiarrhythmic drugs.
Identification of a sphingolipid‐specific phospholipase D activity associated with the generation of phytoceramide‐1‐phosphate in cabbage leaves
Authors: Tanaka Tamotsu , Kida Takashi , Imai Hiroyuki , Morishige Jun‐ichi , Yamashita Ryouhei , Matsuoka Hisatsugu , Uozumi Sachika , Satouchi Kiyoshi , Nagano Minoru , Tokumura Akira 
Published: June 2013

The structure and biosynthetic route for an unidentified lipid (lipid X) detected by TLC of cabbage (Brassica oleracea) lipids was determined. Lipid X is a phospholipid that is resistant to mild alkali and detectable by MALDI‐TOF MS as an adduct with Phos‐tag, a phosphate‐capture zinc complex. Various α‐hydroxy fatty acids (16:0, 22:0, 24:0 and 24:1) were detected by GC‐MS of fatty acid methyl esters prepared from lipid X. The deacyl derivative of lipid X was determined to be 4‐hydroxysphingenine (dehydrophytosphingosine)‐1‐phosphate by MALDI‐TOF MS with Phos‐tag. From these results, lipid X was determined to be phytoceramide‐1‐phosphate (PC1P) with an α‐hydroxy fatty acid. When cabbage homogenates were incubated, PC1P was formed, with a concomitant decrease in the amount of glycosylinositol phosphoceramide (GIPC). The formation of PC1P from GIPC was confirmed by treatment of purified cabbage GIPC with a membrane fraction of cabbage homogenates. Using a partially purified enzyme fraction, we found that the enzyme hydrolyzes GIPC specifically, but not glycerophospholipids and sphingomyelin. Arabidopsis thaliana also had this enzyme activity. From these results, we conclude that a previously uncharacterized phospholipase D activity that specifically hydrolyzes GIPC produces PC1P in brassicaceous plants.
Assessing physiological tipping point of sea urchin larvae exposed to a broad range of pH
Authors: Dorey Narimane , Lançon Pauline , Thorndyke Mike , Dupont Sam 
Published: June 2013

AbstractOur ability to project the impact of global change on marine ecosystem is limited by our poor understanding on how to predict species sensitivity. For example, the impact of ocean acidification is highly species‐specific, even in closely related taxa. The aim of this study was to test the hypothesis that the tolerance range of a given species to decreased pH corresponds to their natural range of exposure. Larvae of the green sea urchin Strongylocentrotus droebachiensis were cultured from fertilization to metamorphic competence (29 days) under a wide range of pH (from pHT = 8.0/pCO2 ≈ 480 μatm to pHT = 6.5/pCO2 ≈ 20 000 μatm) covering present (from pHT 8.7 to 7.6), projected near‐future variability (from pHT 8.3 to 7.2) and beyond. Decreasing pH impacted all tested parameters (mortality, symmetry, growth, morphometry and respiration). Development of normal, although showing morphological plasticity, swimming larvae was possible as low as pHT ≥ 7.0. Within that range, decreasing pH increased mortality and asymmetry and decreased body length (BL) growth rate. Larvae raised at lowered pH and with similar BL had shorter arms and a wider body. Relative to a given BL, respiration rates and stomach volume both increased with decreasing pH suggesting changes in energy budget. At the lowest pHs (pHT ≤ 6.5), all the tested parameters were strongly negatively affected and no larva survived past 13 days post fertilization. In conclusion, sea urchin larvae appeared to be highly plastic when exposed to decreased pH until a physiological tipping point at pHT = 7.0. However, this plasticity was associated with direct (increased mortality) and indirect (decreased growth) consequences for fitness.
Mean platelet volume is decreased in HIV‐infected women
Authors: Qadri S , Holman S , DeHovitz J , Crystal H , Minkoff H , Lazar JM 
Published: June 2013

ObjectivesHIV infection is associated with higher than expected cardiovascular event rates and lowered platelet counts. These conditions are associated with an elevation of mean platelet volume (MPV). The present study compared MPV in HIV‐infected and uninfected women and identified factors influencing MPV values in HIV‐infected women.MethodsA total of 234 HIV‐infected and 134 HIV‐uninfected participants from the Women's Interagency HIV Study (WIHS) had MPV values obtained. HIV‐infected women were older, were more likely to have diabetes and had higher triglyceride levels than HIV‐uninfected women.ResultsThe mean platelet count was lower in HIV‐infected vs. uninfected women [249 cells/μL (95% confidence interval (CI) 238, 259 cells/μL) vs. 276 cells/μL (95% CI 265, 287 cells/μL), respectively; P < 0.01]. Adjusted mean MPV values were lower in the HIV‐infected than in the uninfected group [8.66 fL (95% CI 8.52, 8.79 fL) vs. 9.05 fL (95% CI 8.87, 9.24 fL), respectively]. In multiple regression analysis, after adjusting for other covariates, MPV was positively associated with platelet count, and negatively with HIV infection (model R2 = 0.20; P < 0.01). In multiple regression analysis confined to HIV‐infected women, a lower MPV was independently associated with a history of AIDS‐defining illness (R2 = 0.28; P = 0.03), but not with nadir CD4 count or highly active antiretroviral therapy (HAART) use.ConclusionsHIV‐infected women had lower MPV values than uninfected women, suggesting impaired production rather than increased destruction. Higher than expected cardiovascular event rates cannot be attributed to greater platelet reactivity as measured by MPV.