Morphological and Cytogenetic Characterization and N-myc Oncogene Analysis of a Newly Established Neuroblastoma Cell Line

A permanent cell line established from a xenograft of neuroblastoma which occurred in a 5 year old girl was investigated for its morphological and biological characteristics. The cultured cells were tumorigenic in nude mice. Microscopically, each tumor consisted of small round to polygonal cells with irregular nuclei and prominent nucleoli, corresponding to the features of the primary and xenografted tumor cells. Electron microscopic examination revealed that both the transplanted tumor cells and the cultured cells contained scanty microtubules and dense-core neurosecretory granules. Chromosome analysis of this cell line showed monosomy for chromosomes 1,10,19 and X, and structural rearrangements involving chromosomes 8, 17 and 20, in addition to numerous double minutes. The N- myc oncogene was found to be amplified 40 to 80 fold in the transplanted and cultured tumor cells, as well as in the primary tumor cells. In situ hybridization with a digoxigenin labeled uridine-triphosphate N- myc RNA probe detected abundant mRNA in the tumor cells. This neuroblastoma line may become a valuable in vitro experimental model system for studies aimed at better characterization of neuroblastoma. Acta Pathol Jpn 41: 507 515, 1991.     

Cellular blue nevus of the scalp associated with intracranial involvement

The authors report a rare case of cellular blue nevus located in the right frontotemporoparietal area of the scalp with local extension to the central nervous system. The diagnostic value of computed tomography is discussed.     

Micro-angiographical studies of the medullary venous system of the cerebral hemisphere

In order to identify the zones of convergence of the medullary veins of the cerebral white matter, gelatin-mixed barium sulfate was injected into normal brains at autopsy. A catheter was inserted into the internal jugular veins or the carotid and vertebral arteries. Serial soft tissue roentgenograms of whole brains and brain slices were used to determine the zones of convergence. The deep med-ullary veins had four zones of covergence before draining into the subependymal veins: the first (superficial), second (candelabra), third (palmate) and fourth (subependymal). The zones of various convergence within the white matter were due to the crossing of nerve fiber tracts (e.g. the pes of the corona radiata, the radiation of the corpus callosum, the superior occipitofrontal fasciculus, the tapetum and the sagittal strata). Similar but less conspicuous information about the parenchymal arteries was observed in the arterial injection studies. These results suggest that micro-angiographical studies of the medullary veins of the cerebral white matter provide detailed information on veno-architecture and convergence zones. This information may help in understanding the pathogenesis of medullary venous malformations.     

Novel peptide toxins recently isolated from sea anemones

Sea anemones are a rich source of peptide toxins acting on ion channels. Two classes of peptide toxins, site-3 sodium channel toxins and Kv1 potassium channel toxins, have been well characterized and some of them used as valuable pharmacological reagents. Recently, the following six peptides toxins, which structurally constitute a new family but target different ion channels, have been isolated: BDS-I and -II (Kv3 potassium channel toxins) from Anemonia sulcata, APETx1 (human ether-a-go-go-related gene potassium channel toxin) and APETx2 (acid-sensing sodium channel toxin) from Anthopleura elegantissima, BcIV (sodium channel toxin) from Bunodosoma caissarum and Am II (whose target is unknown) from Antheopsis maculata. In addition, the following structurally novel peptide toxins have also emerged in sea anemones: gigantoxin I (epidermal growth factor-like toxin) from Stichodactyla gigantea and acrorhagins I and II from acrorhagi (specialized aggressive organs) of Actinia equina. This review deals with the structural and functional features of these recently isolated sea anemone peptide toxins that are promising tools in studying the physiology of diverse ion channels.     

Gastric Wall Structure Using a 30 MHz Endoscopic Ultrasound Probe,Focusing upon Delineation of the Muscularis Mucosae

Background: The normal gastric wall has been reported to appear to be a five‐layered structure. The structure of the gastric wall using a 30 MHz endoscopic ultrasound probe and especially the identification of the muscularis mucosae (MM), has not been analyzed clearly. Methods: In a basic study, 11 sections of normal gastric wall with 26 horizontally inserted nylon sutures were immersed in water. The sections were scanned and the findings correlated using standard histology. In a clinical study, 15 early gastric cancers were examined by a 30 MHz endoscopic ultrasound probe. Results: In a basic study, layers deeper than the lower part of the submucosa could not be seen using ultrasonography. The first to fourth layers represented the mucosal layer except the MM, the fifth layer (high‐echo layer) represented the boundary echo and a part of the MM, while the sixth layer (low‐echo layer) represented the rest of the MM. The muscularis mucosae was seen clearly in all samples. In a clinical study the layers deeper than the submucosal layer could not be seen and the MM was visible in 87% of cases. The depth of invasion was estimated accurately in 90% of mucosal cancers and in 80% of submucosal cancers. Conclusion: A 30 MHz endoscopic ultrasound probe, which cannot image the entire gastric wall, can visualize the MM and may help to confirm the structure of gastric wall layers and improve the ability to determine the depth of invasion in gastric cancer.     

Development of a novel statistical model for mandibular kinematics

The purpose of this study was to establish a new statistical method for the analysis of masticatory function. The subjects were patients with anterior crossbite who had received orthognathic surgery. Chewing movement was measured by means of an opto-electronic motion-analysis system. This movement was compared with similar movement in control patients. We sought to develop a statistical model to predict the population average curves of the chewing cycles. In this study, the mandibular incisor point was used as a target point of jaw movement. The combination of a spline function with random coefficients and self-modeling regression (SEMOR) extended to three dimensions was used to predict population average curves for each group. Unquestionably, significant differences were present in some areas. The present modeling method that uses the combination of a spline function and SEMOR is one of the best ways to eliminate subjective estimation with regard to predicting representative chewing cycles.     

Effect of pilsicainide, a pure sodium channel blocker, on spiral waves during atrial fibrillation: theoretical analysis by numerical simulation

This study investigated the effects of a particular type of sodium channel blocker, pilsicainide, on spiral waves, which are a possible mechanism of atrial fibrillation, by using numerical simulation. A meandering spiral wave was induced on a two-dimensional matrix corresponding to the isolated atrial myocardium. The model attempted to simulate the changes caused by pilsicainide. The conductivity was depressed and the refractory period was prolonged with little change in the action potential duration. The dynamic change in the refractory period depended on the preceding coupling interval. A blockline occurred and changed gradually because of the change in the refractory period. The spiral wave became a stable reentry rotating around the blockline, decreasing the excitation frequency in the matrix before rushing out of the matrix. The electrocardiogram showed a slow coarse wave, as well as a real electrocardiographic change by pilsicainide. This might, in part, explain how pilsicainide acts on atrial fibrillation. Key words: sodium channel blocker, pilsicainide, spiral wave, atrial fibrillation, computer simulation.     

EBM in acute stroke]

Evidence-based medicine (EBM) has been emphasized in Japan for these years. In management of acute stroke, prospective stroke registries and randomized controlled trials have provided evidence that helps us examine and treat patients with acute stroke. The author advocates five important key words, DRUGS, for establishing the EBM in stroke management in Japan; 1) Stroke Data Bank, 2) Randomized Controlled Trials (RCT), 3) Stroke Unit (SU), 4) Guidelines and 5) Stroke Scales. Unfortunately evidence in the five key words has always been imported into Japan from the Western countries. We have to create the basis of the EBM in acute stroke management by establishing a Stroke Data Bank, confirming the effects of potential therapies with RCTs, spreading SUs to major hospitals, publishing guidelines for acute stroke management, and using stroke scales in our daily clinical practice.