[A Case of Cardiac Tamponade during Multimodal Treatment for Mediastinal Lymph Node Metastasis of Gastric Cancer].

A 52-year-old man underwent total gastrectomy for gastric cancer and chemoradiotherapy for thoracic paraaortic lymph node metastasis. He also underwent esophageal stent implantation for stenosis. He was admitted to our hospital with fever and breathing difficulty and was diagnosed with infectious pericarditis. He showed symptoms of shock due to cardiac tamponade. After pericardial drainage, his vital signs improved. When signs of infection are detected in patients with a history of chemoradiotherapy or stent implantation, we should consider infectious pericarditis due to esophageal pericardial fistula and apply immediate drainage of cardiac tamponade.

Quantitative Assessment of Fluid Accumulation Using Bioelectrical Impedance Analysis in Patients With Acute Decompensated Heart Failure.

BACKGROUND: Acute decompensated heart failure (ADHF) is generally considered to be a problem of fluid volume overload, therefore accurately quantifying the degree of fluid accumulation is of critical importance in assessing whether adequate decongestion has been achieved. The aim of this study was to develop and validate a method to quantify the degree of fluid accumulation in patients with ADHF. METHODS AND RESULTS: Using multi-frequency bioelectrical impedance analysis (BIA), we measured extracellular water (ECW) volume in 130 ADHF patients on admission and at discharge. We also predicted optimal ECW volume using original equations based on data from 60 control subjects without the signs of HF. Measured/predicted (M/P) ratio of ECW in ADHF patients was observed to decrease from 1.26±0.25 to 1.04±0.17 during hospitalization (P<0.001). The amount of ECW volume reduction was significantly correlated with reduction in body weight (r=0.766, P<0.001). On multivariate analysis, higher M/P ratio of ECW at discharge was associated with increased risk of ADHF readmission or cardiac death within 6 months after discharge. CONCLUSIONS: Multi-frequency BIA-measured ECW was found to offer valuable information for analyzing the pathophysiology of ADHF, and may be a useful guide in the management of this disease.

Recurrent Pericardial Effusion Resulting From Right Ventricular Free Wall Injury Caused by Leadless Pacemaker Tines.

An 87-year-old man developed delayed cardiac tamponade 55 min after leadless pacemaker implantation and recurrent pericardial effusion 20 days later. Electrocardiogram-gated enhanced cardiac computed tomography revealed that the leadless pacemaker tines on the lateral side had penetrated the right ventricular free wall. He underwent off-pump hemostatic surgery.

Modular network SOM.

This study aims to develop a generalized framework of an SOM called a modular network SOM (mnSOM). The mnSOM has an array structure consisting of functional modules that are trainable neural networks, e.g., multi-layer perceptrons (MLPs), instead of the vector units of the conventional SOM. In the case of MLP-modules, an mnSOM learns a group of systems or functions in terms of the input-output relationships in parallel with generating a feature map of them. Thus an mnSOM with MLP modules is an SOM in function space rather than in vector space. In this paper, first, as an example, we focus on a class of mnSOM that consists of MLP modules and introduce the architecture and algorithm. Then, a more generalized framework is described. Finally, some simulation results of an MLP-module-mnSOM are presented.

Estimation of microinhomogeneity of conduction impairment by wavelet analysis during early phase of myocardial ischemia in pigs.

Ventricular fibrillation (VF) is most frequent in the very early phase in acute coronary occlusion, and is triggered by the re-entrant mechanism in this phase. An inhomogeneous conduction in the ischemic myocardium would be substrates for re-entry. The aim of this study was to examine the relationship between the severity of irregularities of the QRS complex and VF. Eleven pigs were analyzed, and the heart was fixed in the pericardial cradle. Ag-AgCl bipolar electrodes were fixed on the epicardium in ischemic and non-ischemic regions. The proximal portion of the left anterior descending coronary artery was occluded for one hour. Electrocardiograms (ECGs) were continuously recorded on a magnetic tape, and wavelet analysis was performed on signal-averaged ECG (25 beats) every 60 sec after the experiment. The number of local maxima (N) and the duration between the first and the last local maximum (D) were automatically measured. N and D significantly increased in the ischemic area, but not in the non-ischemic area. N and D increased approximately twofold just before the occurrence of VF in 8 fibrillated pigs (p<0.01, each). There were significant positive linear relationships between the rate of increase in N and D to VF and basal heart rate before coronary occlusion (r=0.90, p <0.01 in N, r=0.84, p <0.01 in D at 160 Hz). These results suggest that there would be a threshold inhomogeneous conduction for the occurrence of VF and an increase in heart rate would accelerate the inhomogeneous conduction in acute myocardial ischemia.

Tensor SOM and tensor GTM: Nonlinear tensor analysis by topographic mappings.

In this paper, we propose nonlinear tensor analysis methods: the tensor self-organizing map (TSOM) and the tensor generative topographic mapping (TGTM). TSOM is a straightforward extension of the self-organizing map from high-dimensional data to tensorial data, and TGTM is an extension of the generative topographic map, which provides a theoretical background for TSOM using a probabilistic generative model. These methods are useful tools for analyzing and visualizing tensorial data, especially multimodal relational data. For given n-mode relational data, TSOM and TGTM can simultaneously organize a set of n-topographic maps. Furthermore, they can be used to explore the tensorial data space by interactively visualizing the relationships between modes. We present the TSOM algorithm and a theoretical description from the viewpoint of TGTM. Various TSOM variations and visualization techniques are also described, along with some applications to real relational datasets. Additionally, we attempt to build a comprehensive description of the TSOM family by adapting various data structures.

Asymmetric temporal properties in the receptive field of retinal transient amacrine cells.

The speed of signal conduction is a factor determining the temporal properties of individual neurons and neuronal networks. We observed very different conduction velocities within the receptive field of fast-type On-Off transient amacrine cells in carp retina cells, which are tightly coupled to each other via gap junctions. The fastest speeds were found in the dorsal area of the receptive fields, on average five times faster than those detected within the ventral area. The asymmetry was similar in the On- and Off-part of the responses, thus being independent of the pathway, pointing to the existence of a functional mechanism within the recorded cells themselves. Nonetheless, the spatial decay of the graded-voltage photoresponse within the receptive field was found to be symmetrical, with the amplitude center of the receptive field being displaced to the faster side from the minimum-latency location. A sample of the orientation of varicosity-laden polyaxons in neurobiotin-injected cells supported the model, revealing that approximately 75% of these processes were directed dorsally from the origin cells. Based on these results, we modeled the velocity asymmetry and the displacement of amplitude center by adding a contribution of an asymmetric polyaxonal inhibition to the network. Due to the asymmetry in the conduction velocity, the time delay of a light response is proposed to depend on the origin of the photostimulus movement, a potentially important mechanism underlying direction selectivity within the inner retina.

[Joseph Babinski's contribution to neurological symptomatology].

Joseph Babinski (1857-1932) was an excellent clinician. André Breton, a French poet, described Babinski's way of clinical examination in his Manifeste du surréalisme (1924), which vividly revealed Babinski's meticulous character. Babinski is well known by his eponymous Babinski reflex. Although some predecessors had described this phenomenon briefly, its meaning was interpreted by Babinski. His contribution to neurological symptomatology was not restricted to his plantar skin reflex, but also to other wide area. In this article, symptoms described by Babinski, i.e. plantar skin reflex, cerebellar symptoms including cerebellar asynergy, adiadochokinesis, dysmetria, cerebellar catalepsy, and rising sign, platysma sign, anosognosia are explained and are critically discussed.

SOM of SOMs.

This paper proposes an extension of the self-organizing map (SOM), in which the mapping objects themselves are self-organizing maps. Thus a "SOM of SOMs" is presented, which we refer to as a SOM(2). A SOM(2) has a hierarchical structure consisting of a single parent SOM and a set of child SOMs. Each child SOM is trained to represent the distribution of a data class in a manifold, while the parent SOM generates a self-organizing map of the group of manifolds modeled by the child SOMs. Thus a SOM(2) is an architecture that organizes a product manifold represented as (child SOM) x (parent SOM). Such a product manifold is called a fiber bundle in terms of the topology. This extension of a SOM is easily generalized to any combination of SOM families, including cases of neural gas (NG) in which, for example, " NG(2) (=NG x NG) as an NG of NGs" and "NG x SOM as a SOM of NGs" are possible. Furthermore, a SOM(2) can be extended to a SOM(n), such as SOM(3)=SOM x SOM x SOM defined as a "SOM of SOM(2)". In this paper, the algorithms for the SOM(2) and its variations are introduced, and some simulation results are reported.

Nitric oxide controls the light adaptive chromatic difference in receptive field size of H1 horizontal cell network in carp retina.

In carp retina, the receptive field size of the H1-type horizontal cell (HC) network is known to be chromatically selective, as electrophysiological signals are generated by short-wavelength (SW) light stimuli, which spread much less than those for long-wavelength (LW). We have shown previously that the signalling mechanism underlying this chromatic difference operates only in the light-adapted retina and that it involves cGMP as an intermediary messenger. In the present study, the possible role of nitric oxide (NO) as such a control mechanism was investigated. Application of a NO donor (SNP or SNOG) to dark-adapted retinae produced a chromatic difference in the receptive field size, such as in the light-adapted state. This effect was due mainly to a reduction in the spread of signals generated by SW stimuli; LW signalling spread was not altered. No such effect was observed in light-adapted retinae where a chromatic difference in receptive field size was already present. On the other hand, application of the NO 'scavenger' haemoglobin to light-adapted retinae suppressed the chromatic difference. These results are consistent with NO being a light-adaptive retinal neuromodulator involved in the generation of the chromatic difference in H1 cell receptive field size. These results are discussed in the context of two different hypotheses.