Relation between ventriculoarterial coupling and myocardial energetics in patients with idiopathic dilated cardiomyopathy

AbstractObjectives. The purpose of this study was to evaluate left ventricular contractility, arterial loading conditions and the way their interaction affects myocardial energetics.Background. Ventriculoarterial coupling, defined as the ratio of effective arterial elastance to left ventricular end-systolic elastance, is known to reflect the mechanoenergetic performance of the heart. However, relations between the coupling and efficiencies of energy transfer from oxygen consumption to hydraulic energy have not been fully investigated in failing hearts.Methods. Pressure-volume data were measured in 23 patients with idiopathic dilated cardiomyopathy by using a conductance catheter, and myocardial oxygen consumption was obtained simultaneously in 16 patients by a double-thermistor coronary sinus catheter. End-systolic elastance was determined by transient inferior cava occlusion.Results. Data are reported as mean value ± SE. Ventriculoarterial coupling at baseline was 3.14 ± 0.28. It decreased from 3.12 ± 0.43 to 1.86 ± 0.15 (p < 0.05) for the group receiving dobutamine infusion and from 3.16 ± 0.45 to 1.78 ± 0.22 (p < 0.01) for the group receiving the oral phosphodiesterase inhibitor MS-857. The ratio of pressure-volume area to myocardial oxygen consumption had a positive correlation with ventriculoarterial coupling. The ratio of external work to pressure-volume area had a hyperbolic correlation with the coupling. The mechanical efficiency defined as the ratio of external work to myocardial oxygen consumption remained within a narrow range (16.4 ± 1.2%).Conclusions. The degree of ventriculoarterial coupling is far from optimal and the cardiovascular performance is severely depressed mechanically and energetically in patients with idiopathic dilated cardiomyopathy. Although inotropic agents improve the coupling, they have a minimal effect on mechanical efficiency

Interdisciplinary therapy for severe periodontitis with Angle Class II Division 1 malocclusion : A case report with 7-year follow-up

Background: Previous studies have suggested that occlusal discrepancy is a risk factor contributing to periodontal disease. 1-3 Occlusal discrepancy could increase the risk of infrabony defects. This is a case of a patient with severe periodontitis who exhibited many infrabony defects in the molar region due to malocclusion-induced trauma. Here, we report the 7-year prognosis of the patient after periodontal regenerative and comprehensive orthodontic therapies for functional recovery with implant prosthodontics. Case Description: A 54-year-old female presented with the chief complaint of masticatory disturbance. In the molar region, significant tooth mobility, deep periodontal pockets, and infrabony defects were observed. She had excessive overjet, resulting in collapse of anterior guidance. Malocclusion was considered to be an exacerbating factor of the infrabony defects. After initial periodontal therapy, we performed periodontal regenerative therapy in the mandibular molar regions. We carefully placed implants in a position in the maxillary molar region that would ensure an appropriate anterior dental relationship after orthodontic treatment. Comprehensive orthodontic treatment was subsequently performed using implants as anchoring units. Then, definitive surgery was performed on the mandibular molars before placing the final prosthesis. A favorable periodontal condition and a stable occlusion have been maintained for the 7-year post-treatment period. Practical Implications: Comprehensive and interdisciplinary treatment enables stable occlusion and establishment of periodontal tissue and peri-implant tissues with high cleansability, even in patients with severe periodontitis and malocclusion. In the present case, a favorable long-term treatment outcome can be expected

±Genetic structure of the oak wilt vector beetle Platypus quercivorus: inferences toward the process of damaged area expansion

<p>Abstract</p> <p>Background</p> <p>The ambrosia beetle, <it>Platypus quercivorus</it>, is the vector of oak wilt, one of the most serious forest diseases in Japan. Population genetics approaches have made great progress toward studying the population dynamics of pests, especially for estimating dispersal. Knowledge of the genetic structuring of the beetle populations should reveal their population history. Using five highly polymorphic microsatellite loci, 605 individuals from 14 sampling sites were assessed to infer the ongoing gene flow among populations as well as the processes of expansion of damaged areas.</p> <p>Results</p> <p>Population differentiation (<it>F</it>_ST= 0.047, <it>G'</it>_ST= 0.167) was moderate and two major clusters were detected by several methods, dividing the samples into north-eastern and south-western populations, a similar genetic divergence was reported in host oak trees. Within the north-eastern populations, the subgroups mostly corresponded to differences in the collection period. The genetic characteristics of the population might have changed after 2 years due to the mixing of individuals between populations with enhanced migration related to population outbreaks. Because isolation by distance was detected for whole populations and also within the north-eastern populations, migration was considered to be limited between neighbouring populations, and most populations were suggested to be in genetic equilibrium of genetic drift and gene flow. Recent bottlenecks were found in some populations with no geographical bias; however, they were all from newly emerged oak wilt forests. The emergence of oak wilt should have induced intense fluctuations in the beetle population size.</p> <p>Conclusions</p> <p>Because the genetic boundaries coincide, we suggest that the geographical structuring of the beetle was formed by co-evolution with the host species. Our findings indicate the oak wilt expansion process.</p

Comprehensive treatment for severe periodontitis with pathologic tooth migration−related bimaxillary protrusion : A case report with 3-year follow-up

Background: Patients with severe periodontitis often experience pathologic tooth migration (PTM), which impairs esthetics and leads to occlusal disharmony (e.g., premature contacts and/or traumatic occlusion) that can further exacerbate periodontitis. Here, we describe a patient who exhibited severe periodontitis with PTM-related bimaxillary protrusion. This report includes 3-year clinical outcomes following periodontal regenerative therapy, implant-anchored orthodontic therapy, and implant prosthodontics intended to achieve both functional and esthetic improvements. Case Description: A 63-year-old woman presented with the chief complaint of upper anterior tooth mobility. Clinical examination revealed excessive tooth mobility, deep periodontal pockets, and infrabony defects in all teeth. All teeth exhibited PTM; the mandibular anterior teeth exhibited marked protrusion caused by the progression of periodontitis. After initial periodontal therapy, periodontal regenerative therapy was performed in all molar regions. At 9 and 6 months postoperatively, comprehensive orthodontic treatment was initiated for the mandible and maxilla, respectively, using orthodontic anchorage devices to achieve acceptable functional occlusion. After orthodontic treatment, staged guided bone regeneration was performed and dental implants were placed in the severely resorbed maxillary anterior ridge. This comprehensive treatment yielded favorable periodontal conditions, stable occlusion, and good esthetic outcomes. Practical Implications: Favorable esthetics, stable occlusion, and highly cleansable periodontal tissues were achieved with well-planned interdisciplinary and comprehensive treatment, although the patient had severe periodontitis and PTM-related bimaxillary protrusion

Magnetic-Field-Independent Ultrasonic Dispersions in the Magnetically Robust Heavy Fermion System SmOs4Sb12

Elastic properties of the filled skutterudite compound SmOs$_4$Sb$_{12}$ have been investigated by ultrasonic measurements. The elastic constant $C_{11}(\omega)$ shows two ultrasonic dispersions at $\sim$15 K and $\sim$53 K for frequencies $\omega$ between 33 and 316 MHz, which follow a Debye-type formula with Arrhenius-type temperature-dependent relaxation times, and remain unchanged even with applied magnetic fields up to 10 T. The corresponding activation energies were estimated to be $E_2$ = 105 K and $E_1$ = 409 K, respectively. The latter, $E_1$, is the highest value reported so far in the Sb-based filled skutterudites. The presence of magnetically robust ultrasonic dispersions in SmOs$_4$Sb$_{12}$ implies a possibility that an emergence of a magnetically insensitive heavy fermion state in this system is associated with a novel local charge degree of freedom which causes the ultrasonic dispersion.Comment: 5 pages, 4 figure

Atomic structure and electronic properties of MgO grain boundaries in tunnelling magnetoresistive devices

Polycrystalline metal oxides find diverse applications in areas such as nanoelectronics, photovoltaics and catalysis. Although grain boundary defects are ubiquitous their structure and electronic properties are very poorly understood since it is extremely challenging to probe the structure of buried interfaces directly. In this paper we combine novel plan-view high-resolution transmission electron microscopy and first principles calculations to provide atomic level understanding of the structure and properties of grain boundaries in the barrier layer of a magnetic tunnel junction. We show that the highly [001] textured MgO films contain numerous tilt grain boundaries. First principles calculations reveal how these grain boundaries are associated with locally reduced band gaps (by up to 3 eV). Using a simple model we show how shunting a proportion of the tunnelling current through grain boundaries imposes limits on the maximum magnetoresistance that can be achieved in devices