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Biomedical subjects

N Yahagi

Publications and source records attributed to N Yahagi.

121 records · Page 7Linked to original sources
PubMed1989

Structural parts involved in activation and inactivation of the sodium channel.

Structure-function relationships of the sodium channel expressed in Xenopus oocytes have been investigated by the combined use of site-directed mutagenesis and patch-clamp recording. This study provides evidence that the positive charges in segment S4 are involved in the voltage-sensing mechanism for activation of the channel and that the region between repeats III and IV is important for its inactivation.

Action Potentials↗
PubMed1988

Functional expression of cloned cDNA encoding sodium channel III.

mRNA synthesized by transcription in vitro of the cloned cDNA encoding rat brain sodium channel III directs the formation of a functional sodium channel in Xenopus oocytes. The tissue distribution of the mRNAs encoding sodium channels I, II and III has been studied by blot hybridization analysis with specific probes.

Animals↗
PubMed1988

Ti (WT31)-negative, CD3-positive, large granular lymphocyte leukemia with nonspecific cytotoxicity.

A case of WT31-, CD3+ large granular lymphocyte leukemia is reported. On surface marker analysis, the proliferating cells were found to be CD3+4-8-16+ and WT31-. By two-color immunofluorescence staining, CD3+4-8- cells were found to be WT31-, and a small population of WT31+ cells expressed either CD4 or CD8. WT31-, CD3+ cells were also identified in a bulk culture of lymphocytes expanded in vitro. Because WT31 monoclonal antibody (MoAb) reacts with the nonpolymorphic epitope of the disulfide-linked heterodimer of the T cell antigen receptor (Ti), the absence of the WT31-reactive Ti determinant may represent an expression of different CD3-associated polypeptides. The rearrangement of the Ti-beta and Ti-gamma genes but not the immunoglobulin gene was demonstrated, and the single pattern of rearrangement indicated the monoclonal origin of the lymphocytes. When the lymphocytes were assayed for their cytotoxicity against K562, MOLT-4, Daudi, and Raji tumor cell lines, a broad spectrum of cytotoxicity for these tumor cells was observed, and the lymphocytes also exhibited antibody- and lectin-dependent cellular cytotoxicity and lymphokine-activated killer activity. Treatment with anti-CD2 and anti-CD3 MoAbs inhibited their nonspecific cytotoxicity. The anti-CD3-mediated inhibition of nonspecific cytotoxicity suggested that an as yet unidentified Ti, present in association with the CD3 molecule on these lymphocytes, serves as a specific receptor for target tumor cell recognition.

Antibodies, Monoclonal↗
PubMed1987

The effects of halothane and pentobarbital on the threshold of transpulmonary passage of venous air emboli in dogs.

The influence of halothane, pentobarbital, and their interaction on the passage of air across the pulmonary circulation was studied in 12 dogs using transesophageal M-mode echocardiography for air detection in the left atrium and/or aorta. Air was detected in the left atrium and/or aorta after pulmonary artery air injection of 0.04 ml/kg during 1% halothane anesthesia (n = 5). Addition of pentobarbital changed the threshold to 1.0 ml/kg. During pentobarbital anesthesia with and without halothane (n = 7), the thresholds were 1.1 and 1.2 ml/kg, respectively. The authors conclude that the threshold for transpulmonary passage of venous air is higher during anesthesia with pentobarbital with or without halothane than during anesthesia with halothane alone.

Anesthesia, General↗
PubMed1986

Cardiopulmonary effect of halothane concentration during pulmonary air embolism in dogs.

The purpose of this study was to determine the effect of different halothane concentrations on the hemodynamic consequences of pulmonary air embolism in dogs. The animals were studied in two groups. Group A (N = 11) at a halothane concentration of 0.5%, and Group B (N = 8) at a halothane concentration of 1.5%. Air was injected into a central vein in a bolus of 0.5 ml/kg, 1 ml/kg, and 2 ml/kg. With the lower halothane concentration, sudden loading to the right heart and pulmonary artery occurred with air embolism. Recovery in this group was faster in comparison to the higher concentration of halothane. Survival was not effected with air embolism to 2 ml/kg.

Animals↗
PubMed1984

[Minimal-flow xenon and semiclosed circuit anesthesia for computed tomographic measurement of local cerebral blood flow (LCBF)].

For the purpose of decreasing the volume of expensive xenon, anesthesia with minimal-flow xenon and semiclosed circuit were induced for computed tomographic LCBF measurement. Eighteen patients with ischemic cerebral disease were studied. Anesthesia was induced with minimum dose of thiopental, diazepam and fentanyl. Muscle relaxation was obtained by means of pancuronium bromide. Patients were intubated and ventilated mechanically with flows of 6 l/min. O2 for 20 to 30 minutes to eliminate nitrogen from the system. O2 concentrations in semiclosed circuit were monitored throughout the procedures using galvanic battery. Endtidal CO2 tension was also measured for maintaining normocarbia. Blood gas analyses were carried out before xenon inhalation, during xenon inhalation and immediately before stopping inhalation of xenon-oxygen mixture. Xenon inhalation programs were subdivided into three groups, each of them consisted of 6 patients. The formula for calculating fresh gas flow for low flow semiclosed circuit was introduced according to Shimoji's which was based on the original formula of Foldes. O2 concentration in circuit was predicted to be 25%. Mean xenon uptake for initial 20 minutes was predicted to be 125 ml/min. or 360 ml/min. (Formula: see text) (CRO2: O2% in semiclosed circuit. FO2: fresh O2 flow ml/min. FXe: fresh xenon flow ml/min. VO2: oxygen consumption ml/min. VXe: mean xenon uptake ml/min.) The first group started xenon inhalation during pure xenon inflow into semiclosed circuit for two minutes and followed by about 68% xenon in O2 inhalation for 23 minutes. FXe and VXe were fixed at 700 ml/min and 360 ml/min respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Endoscopic resection of adenoma of the minor papilla.

Tumors of the minor papilla of the duodenum are rare. We successfully and safely treated a 16 mm sessile adenoma of the minor papilla using endoscopic resection. Endoscopic retrograde cholangiopancreatography (ERCP) yielded a normal cholangiopancreatogram with blind termination of the duct of Santorini in the minor papilla. We recommend endoscopic resection and histological examination of the entire lesion for adenomas of the minor papilla in patients without pancreas divisum.

Adenoma↗
PubMedDate not supplied

Endoscopic submucosal dissection for gastric neoplasia: experience with the flex-knife.

Although the standard treatment for gastric neoplasia is still surgical resection, endoscopic resection has been accepted for some of these lesions in an early stage. Among several methods of endoscopic resection, endoscopic submucosal dissection has been developed to remove the lesions in an en bloc fashion regardless of size, shape, coexisting ulcer, and location. However, indication of endoscopic submucosal dissection is strictly confined by two aspects; those are the possibility of nodal metastases and technical difficulty. Nowadays, several knives for endoscopic submucosal dissection are available and each of them has some merits and demerits. We describe how to perform endoscopic submucosal dissection in the stomach by using the flex-knife, a new endoscopic device specifically designed for submucosal dissection, emphasizing its special features from our experience.

Endoscopy↗