Schwannoma of the nasal septum presenting as a multicentric neuronal tumour

PROBLEM

Schwannomas (neurilemmomas) are benign primary tumours that arise from Schwann cells. Schwannomas arising from the nasal septum are exceptionally rare. Here, we report a unique case of schwannoma of the nasal septum presenting as a multicentric neuronal tumour.

RESULTS

A 40-year old male sustained intermittent left tinnitus. Magnetic resonance imaging revealed masses near the nasal septum and upper cervical cord in addition to a tumour in the left cerebellopontine (CP) angle. The tumour in the nasal septum was completely resected by endoscopic endonasal surgery and diagnosed as a typical schwannoma. The CP angle tumour was treated with stereotactic radiosurgery, while the asymptomatic cord lesion showed no significant growth and remains under observation.

CONCLUSION

Endoscopic endonasal surgery is useful for the resection of schwannomas of the nasal septum. Schwannomas of the nasal septum may present as multiple neuronal tumours.

Predictors of in-hospital outcomes after primary percutaneous coronary intervention for acute myocardial infarction in patients with a high Killip class

OBJECTIVE

The predictors of in-hospital outcomes after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) complicated with heart failure or cardiogenic shock at presentation remain unclear.

METHODS

Using the AMI-Kyoto Multi-Center Risk Study database, the clinical background characteristics, angiographic findings, primary PCI results, and in-hospital prognoses were retrospectively compared between primary PCI-treated AMI patients with a Killip class status of ≥2 (Killip 2-4 patients, n=390) and those with a Killip class 1 status (Killip 1 patients, n=1,057).

RESULTS

The Killip 2-4 patients were more likely to have a higher age and proportion of women and exhibited a higher prevalence of previous myocardial infarction, diabetes mellitus and chronic kidney disease or anemia on admission, lower systolic blood pressure (SBP) values on admission, a higher rate of multivessels or left main trunk as the culprit artery, a larger number of diseased vessels, a lower Thrombolysis In Myocardial Infarction (TIMI) grade in the infarct-related artery (IRA) before/after primary PCI and a significantly higher in-hospital mortality rate than the Killip 1 patients. According to a multivariate analysis, age was found to be an independent positive predictor of in-hospital mortality, while admission SBP was an independent positive predictor of in-hospital survival in both groups. In contrast, anemia on admission was found to be an independent predictor of in-hospital death, while the TIMI 3 flow in the IRA after PCI was found to be an independent factor for survival in the Killip 2-4 patients, but not the Killip 1 patients.

CONCLUSION

Anemia on admission and the final TIMI 3 flow in the IRA are critical determinants of in-hospital death in AMI patients with a Killip class status of ≥2 undergoing primary PCI.

Visualization Analysis of Asymmetric Fountain Flow Phenomenon in Injection Molding of Filler-reinforced Resins by Rotary Runner Exchange System

In this study, we attempted to visualize the flow patterns inside molded samples of glass-fibers or talc reinforced GPPS and PP especially in the vicinity of the flow front, using a rotary runner exchange system which instantaneously switches melt flowing into the cavity. From the visualization results, an extremely characteristic flow behavior was seen at the flow front area for resins with fillers which was not observed for those without fillers. Especially in the case of resins with 40 wt.% talc or 30 wt.% GF, a-symmetric zigzag fountain flows were generated alternately upward and downward along the cavity width direction. Moreover along the outer layer of the flow front, one observed a large amount of residual resin remaining for a long time during the cavity filling process, in the case of 40 wt.% GF, primarily due to the increase of viscosity which restricts the occurrence of diverging flow. Based on the above visualization results, we proposed a generic model of zigzag fountain flow; an a-symmetric upward flow in a certain area starts preventing the fountain flow in the upper side of the adjacent area, causing the diverging center to sink. This phenomenon subsequently causes an a-symmetric flow in the opposite direction in the next adjacent area, which continuously propagates along the cavity width direction.

Visualization Analysis of a Multilayer Foam Development Process in Microcellular Injection Molding

In this study, cross-sectional analyses were performed on microcellular injection-molded high-impact polystyrene products. The results confirm that the following five types of layers were formed: Skin layers I (the silver streak layer) and II (a nonfoamed layer), Core layers I (cell diameter, d > 150 μm), II (d < 50 μm), and III (d > 100 μm). As the maximum in-mold pressure (Pmax) was increased from 5 to 30 MPa, the thickness of Skin layer II remained nearly constant. However, the foam types in the core layers changed from I and II to II and III or III only, resulting in an increase in cell diameter and a decrease in cell density. The process of cellular structure formation was observed using a glass-inserted mold, which revealed that this process consists of a flow (with a burst of cells at the melt front and the subsequent flow of the melt containing the cells), an end of the filling (involving elastic compression or the dissolution and disappearance of cells formed in the flow stage), and a cooling (new cell generation and growth and cooling solidification). Based on these cross-sectional observations, in concert with melt-pressure measurements and visualizations, we developed a model describing the formation process of Skin layer II and the core layers including a new concept that considers the melt pressure inside the cavity. The following layers are incorporated into the model: Skin layer II: A nonfoamed layer is formed in the area of the melt front where gases diffuse out from within the melt during the filling stage, and this nonfoamed layer moves to from melt front to the surface of the product due to fountain flow. Core layers I and II: A multilayer is formed containing a distribution of cells preserved from the flow stage due to the low compression forces, Core layer III: cells are dissolved in the melt due to strong compression forces at the end of the filling stage and then reform and grow in the cooling stage.

Visualization Analysis of Resin Flow Behavior around a Flow Front Using a Rotary Runner Exchange System

In plastic injection molding, external defects such as flow marks are serious problems. These external defects are known to occur during cavity filling processes inside the mold, and are closely related to resin flow behavior in the flow front area. In this study, the authors propose a new method for visualizing in-mold resin flow behavior using a glass-inserted mold and rotary runner exchange system capable of instantaneously switching two types of melt at the runner just before the gate. This method is capable not only of dynamic visualization, but also static visualization by the observation of cross-sections of a sample, because colored resins switched multiple times at the gate spread in layers inside the sample and freeze. Using this method and general purpose polystyrene, visualization analysis of the flow behavior of inner layer resins near the flow front in simple rectangular cavities was carried out. As a result, it was found that resins reaching the flow front are not exposed at the molded product surface immediately after the fountain-flow process, but remain along the circumference of the flow front for a long period of time, and then stretch out into a thin film-like shape to form the surface of the molded product. In addition, the inner layer resins near the flow front form a converging flow just before reaching the flow front and then form a fountain flow. It was also confirmed that this is a general phenomenon in the fountain-flow process during injection molding regardless of whether the resin is crystalline or noncrystalline. Based on these results, we built a model on the flow of inner layer resins near the flow front of general resins.

Exacerbation of diabetic nephropathy by hyperlipidaemia is mediated by Toll-like receptor 4 in mice

AIMS/HYPOTHESIS

Hyperlipidaemia is an independent risk factor for the progression of diabetic nephropathy, but its molecular mechanism remains elusive. We investigated in mice how diabetes and hyperlipidaemia cause renal lesions separately and in combination, and the involvement of Toll-like receptor 4 (TLR4) in the process.

METHODS

Diabetes was induced in wild-type (WT) and Tlr4 knockout (KO) mice by intraperitoneal injection of streptozotocin (STZ). At 2 weeks after STZ injection, normal diet was substituted with a high-fat diet (HFD). Functional and histological analyses were carried out 6 weeks later.

RESULTS

Compared with treatment with STZ or HFD alone, treatment of WT mice with both STZ and HFD markedly aggravated nephropathy, as indicated by an increase in albuminuria, mesangial expansion, infiltration of macrophages and upregulation of pro-inflammatory and extracellular-matrix-associated gene expression in glomeruli. In Tlr4 KO mice, the addition of an HFD to STZ had almost no effects on the variables measured. Production of protein S100 calcium binding protein A8 (calgranulin A; S100A8), a potent ligand for TLR4, was observed in abundance in macrophages infiltrating STZ-HFD WT glomeruli and in glomeruli of diabetic nephropathy patients. High-glucose and fatty acid treatment synergistically upregulated S100a8 gene expression in macrophages from WT mice, but not from KO mice. As putative downstream targets of TLR4, phosphorylation of interferon regulatory factor 3 (IRF3) was enhanced in kidneys of WT mice co-treated with STZ and HFD.

CONCLUSIONS/INTERPRETATION

Activation of S100A8/TLR4 signalling was elucidated in an animal model of diabetic glomerular injury accompanied with hyperlipidaemia, which may provide novel therapeutic targets in progressive diabetic nephropathy.

Primary percutaneous coronary intervention and intravascular ultrasound imaging for coronary thrombosis after cisplatin-based chemotherapy

Although cisplatin is indispensable for the chemotherapy treatment of many malignancies, cisplatin-associated thrombosis is attracting increasing attention. However, experience of primary percutaneous coronary intervention (PCI) and intravascular ultrasound imaging (IVUS) for coronary thrombosis, possibly due to cisplatin-based chemotherapy, has been limited. Case 1 with postoperative gastric cancer developed acute myocardial infarction (AMI) on the sixth day of the second chemotherapy course with conventional doses of cisplatin and tegafur gimeracil oteracil potassium. Emergency coronary angiography (CAG) showed a filling defect in the proximal left anterior descending coronary artery (LAD) concomitant with no reflow in the distal LAD. Case 2 with advanced lung cancer and brain metastasis suffered AMI on the fifth day of the first chemotherapy course with conventional doses of cisplatin and gemcitabine. Emergency CAG delineated a total occlusion in the proximal right coronary artery. In both cases, thrombectomy using aspiration catheter alone obtained optimal angiographic results and subsequent IVUS revealed no definite atherosclerotic plaque, while slow flow still remained even after selective intra-coronary infusion of vasodilator in the case 1. These cases suggest that primary PCI using thrombus-aspiration catheter might be safe and effective for coronary thrombosis due to cisplatin-based chemotherapy.

Predictor Using an Error-Convergence Neuron Network and its Application to Electrocardiograms

The output error of a neuron network cannot converge at zero, even if the training for a neuron network is iterated many times. “Error-convergence neuron network” in which the output error of a singleoutput system uses neuron networks with multiplestep convergence, has been designed to resolve this problem. The output error is converged at zero by setting infinite steps of the neuron network. Three types of neuron network systems also have been designed. They are “Error-convergence parallel neuron network,” “Error-convergence recurrent neuron network,” and “Error-convergence parallel recurrent neuron network.” A subsequent prediction can be obtained by recurring the prediction of a predictor to its input if the predictor is free of prediction error. An error-convergence neuron network can be applied to realize this predictor. “Error-convergence neuron network predictor” has been proposed as such a predictor. In this study, its feasibility is investigated by performing prediction training for the errorconvergence neuron network predictor constructed of second-order Volterra neuron networks with two steps, using the nonlinear time series signal of a normal sinus rhythm electrocardiogram. Predictions without any error were obtained.