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A reaction–diffusion approximation is a method that solutions of multi-component reaction–diffusion systems approximate those of differential equations. We introduce the reaction–diffusion approximations of a semilinear wave equation and a semilinear damped wave equation under some assumptions of a reaction term. These approximation systems consist of a two-component reaction–diffusion system with a small parameter. In this paper, we prove that a first component of a solution for the system converges to a solution for the semilinear damped wave equation as the parameter tends to zero. Moreover, let us show the numerical results of reaction–diffusion approximation for the wave equation and the damped wave equation, respectively. [ABSTRACT FROM AUTHOR]

Cardiotocography records fetal heart rates and their temporal relationship to uterine contractions. To identify high risk fetuses, obstetricians inspect cardiotocograms (CTGs) by eye. Therefore, CTG traces are often interpreted differently among obstetricians, resulting in inappropriate interventions. However, few studies have focused on quantitative and nonbiased algorithms for CTG evaluation. In this study, we propose a newly constructed deep neural network model (CTG-net) to detect compromised fetal status. CTG-net consists of three convolutional layers that extract temporal patterns and interrelationships between fetal heart rate and uterine contraction signals. We aimed to classify the abnormal group (umbilical artery pH < 7.20 or Apgar score at 1 min < 7) and the normal group from CTG data. We evaluated the performance of the CTG-net with the F1 score and compared it with conventional algorithms, namely, support vector machine and k-means clustering, and another deep neural network model, long short-term memory. CTG-net showed the area under the receiver operating characteristic curve of 0.73 ± 0.04, which was significantly higher than that of long short-term memory. CTG-net, a quantitative and automated diagnostic aid system, enables early intervention for putatively abnormal fetuses, resulting in a reduction in the number of cases of hypoxic injury. [ABSTRACT FROM AUTHOR]

The receptor for advanced glycation end-products (RAGE) and the G protein-coupled angiotensin II (AngII) type I receptor (AT1) play a central role in cardiovascular diseases. It was recently reported that RAGE modifies AngII-mediated AT1 activation via the membrane oligomeric complex of the two receptors. In this study, we investigated the presence of the different directional crosstalk in this phenomenon, that is, the RAGE/AT1 complex plays a role in the signal transduction pathway of RAGE ligands. We generated Chinese hamster ovary (CHO) cells stably expressing RAGE and AT1, mutated AT1, or AT2 receptor. The activation of two types of G protein α-subunit, Gq and Gi, was estimated through the accumulation of inositol monophosphate and the inhibition of forskolin-induced cAMP production, respectively. Rat kidney epithelial cells were used to assess RAGE ligand-induced cellular responses. We determined that RAGE ligands activated Gi, but not Gq, only in cells expressing RAGE and wildtype AT1. The activation was inhibited by an AT1 blocker (ARB) as well as a RAGE inhibitor. ARBs inhibited RAGE ligand-induced ERK phosphorylation, NF-κB activation, and epithelial–mesenchymal transition of rat renal epithelial cells. Our findings suggest that the activation of AT1 plays a central role in RAGE-mediated cellular responses and elucidate the role of a novel molecular mechanism in the development of cardiovascular diseases. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) patients often have altered body composition including reduced muscle mass and increased fat mass. Some RA patients are likely to increase visceral fat without obesity [Body Mass Index (BMI) ≥ 25]. The objective of the study was to determine the association between obesity and/or visceral adiposity and the risk for atherosclerosis in Japanese RA patients. Obesity was evaluated using the BMI, with visceral adiposity evaluated using the visceral fat area (VFA) and the visceral/subcutaneous fat ratio (V/S ratio), quantified using the dual bioelectrical impedance method. Atherosclerosis was evaluated based on the intima-media thickness (IMT) and Plaque score (PS) of the carotid artery, measured using ultrasonography. Multivariate analysis was performed to determine the factors associated with IMT and PS. IMT and PS were compared among groups of patients sub-classified according to BMI and VFA levels. The V/S ratio was higher in RA patients than healthy controls, after adjustment for age, BMI, and waist circumference. On multivariate analysis, the V/S ratio, but not the BMI, was independently associated with the IMT and PS. Among the sub-classifications for BMI and VFA, non-obese patients with a high visceral adiposity (18.5 ≤ BMI < 25 kg/m2 and VFA ≥ 100 cm2) had the highest IMT (mean IMT, 0.93 ± 0.29 mm; maximum IMT, 1.44 ± 0.71 mm) and PS (1.43 ± 0.61), compared to all other BMI and VFA subgroups. RA patients have increased visceral adiposity, which is associated with a high prevalence of atherosclerotic of plaques. Non-obese RA patients who have visceral adiposity have a specifically higher risk for atherosclerosis. [ABSTRACT FROM AUTHOR]

Nonlocal interactions, which have attracted attention in various fields, result from the integration of microscopic information such as a transition possibility, molecular events, and signaling networks of living creatures. Nonlocal interactions are useful to reproduce various patterns corresponding to such detailed microscopic information. However, the approach is inconvenient for observing the specific mechanisms behind the target phenomena because of the compression of the information. Therefore, we previously proposed a method capable of approximating any nonlocal interactions by a reaction-diffusion system with auxiliary factors (Ninomiya et al., J Math Biol 75:1203-1233, 2017). In this paper, we provide an explicit method for determining the parameters of the reaction-diffusion system for the given kernel shape by using Jacobi polynomials under appropriate assumptions. We additionally introduce a numerical method to specify the parameters of the reaction-diffusion system with the general diffusion coefficients by the Tikhonov regularization. [ABSTRACT FROM AUTHOR]

Recent years have seen the introduction of non-local interactions in various fields. A typical example of a non-local interaction is where the convolution kernel incorporates short-range activation and long-range inhibition. This paper presents the relationship between non-local interactions and reaction-diffusion systems in the following sense: (a) the relationship between the instability induced by non-local interaction and diffusion-driven instability; (b) the realization of non-local interactions by reaction-diffusion systems. More precisely, it is shown that the non-local interaction of a Mexican-hat kernel destabilizes the stable homogeneous state and that this instability is related to diffusion-driven instability. Furthermore, a reaction-diffusion system that approximates the non-local interaction system with any even convolution kernel is shown to exist. [ABSTRACT FROM AUTHOR]

To disclose the neuropathological progression course of Machado-Joseph disease (MJD), magnetic resonance imaging (MRI) findings of six genetically confirmed MJD cases (four males and two females, including an autopsied female, all unrelated to one another) were further investigated on neurodegeneration. Brain MRI studies were repeated in all cases at different stages of the disease. Ages at the first MRI study ranged from 47 to 65 years (55.2 ± 7.1), with observation periods from 4.5 to 10.6 years (6.95 ± 2.48). We paid particular attention to two types of previously reported MRI findings detectable using T2-weighted images. One is located just outside the internal capsules, and another in the pons. A linear high-intensity change along the internal capsules was detected in all cases, and showed progression during the observation period. A comparison between MRI and autopsy findings suggested that the lesion might reflect degeneration with neuronal loss, astrocytosis, and gliosis in the internal segment of the globus pallidus. A cross-shaped high-intensity change in the pons was well advanced but still incomplete in all cases. In this region, pontine transverse fibers were atrophic, while longitudinal fibers remained intact. Pontine nuclei showed apparent nerve cell loss, and the remaining cells had many 1C2-positive intranuclear inclusions. Since these findings were detected both by lifetime images and by postmortem examination, MRI intensity changes could track the progression of neurodegeneration. Based on a comparison between MRI findings and neuropathology, the degeneration of an internal segment of the globus pallidus (one of the pathological features of MJD) had progressed following the initial symptoms. [ABSTRACT FROM AUTHOR]

This study investigated the relationship between caries assessment using a laser fluorescence device (DIAGNOdent), and bacterial invasion in arrested carious dentin detected by polymerase chain reaction (PCR). The ten extracted human molars used in this study had black or dark brown, hard occlusal carious lesions, and were found to be only weakly stained or unstained with a caries detector dye of 1% acid red in propylene glycol. In those extracted human molars, dentin was removed in the direction of the pulp chamber at 150-μm intervals. During each removal (104 sections in total), the dentin surface was assessed with DIAGNOdent, and a dentinal tissue sample was taken with a round bur. Bacterial DNA of each tissue sample was examined using PCR and primers based on the nucleotide sequence of a conserved region of bacterial 16S rDNA. Rates of bacterial detection increased as the DIAGNOdent values increased. When the DIAGNOdent values were <10, the rate of bacterial detection was 0%. The area under the receiver operating characteristic curve of the DIAGNOdent values was 0.87. These results indicate that the DIAGNOdent values of arrested dentinal carious lesion were closely related to the rates of bacterial detection. [ABSTRACT FROM AUTHOR]

Previous studies from this laboratory and others have suggested the evidences that acidic glycosphingolipid, ganglioside GM1 (GM1), is an endogenous regulator of high affinity nerve growth factor receptor, Trk, which is an essential factor for the normal development and differentiation of neuronal cells by forming a complex with Trk. The present study was aimed to examine whether Trk expressed in cells that are deficient in endogenous GM1 due to the mutation of GM1 synthase gene (NG-CR72 cells) is responsive to its ligand nerve growth factor and how genetic restoration of GM1 synthase gene by a stable transfection of the gene affects the function of the Trk protein. The data clearly showed that (1) confocal lazor microscopic studies disclosed NG-CR72 cells are really deficient in GM1, (2) stable transfection of GM1 synthase cDNA into these cells (NG-CR72G cells) restores the expression of GM1 in the cells, and (3) Trk protein is expressed in NG-CR72 cells but its location seemed not to be on the plasma membrane, whereas we clearly observed that the Trk protein is expressed on the plasma membrane in NG-CR72G cells. (4) NGF did not elicit the autophosphorylation of the Trk protein in GM 1 deficient NG-CR72 cells but did elicit the activation of the Trk protein in NG-CR72G cells with an activation of mitogen activated protein kinase. These studies strongly suggested that GM1 is necessary for the normal expression of the Trk protein function and for normal targeting of the Trk protein to the plasma membrane. [ABSTRACT FROM AUTHOR]

The present polysomnographic study compared sleep structures in patients with post-traumatic stress disorder (PTSD) with those of age-matched normal controls. Seven patients with relatively acute PTSD and seven normal controls were studied in a sleep laboratory. The post-traumatic patients demonstrated significantly poorer sleep, reduced sleep efficiency, increased numbers of arousals, and a remarkably decreased percentage of slow-wave sleep (SWS), and a decreased percentage of rapid eye movement (REM) sleep. In two patients who reported having frequent nightmares, REM interruptions of more than 10 min were recognized. Although several previous polysomnographic studies in PTSD subjects have demonstrated disagreements regarding REM sleep and slow-wave sleep, the subjects in those studies were mainly chronic PTSD subjects. Regarding this point, because we investigated relatively acute PTSD subjects, characteristic sleep data might be obtained. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor concerning hypersomnia, asterixis and cataplexy in association with orexin A-reduced hypothalamic tumor.