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Biomedical subjects

S Kaseda

Publications and source records attributed to S Kaseda.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Recent trial of bronchoplasty: reconstruction of air way in the vicinity to the segmental bronchi].

With modern techniques sleeve lobectomy is the safe method of surgery for lung diseases. The reports of reconstructive surgery of more peripheral bronchi are still a few. We experienced anastomosis at the vicinity to the segmental bronchi in 11 patients with 3 central early cancers, 2 synchronous double cancers, 1 adenoid cystic carcinoma, 1 pulmonary metastasis and 4 stage III lung cancers. Operative procedures were sometimes complicated and various. Wedge segmentectomy were performed in 4 cases, of whom one patient died from pneumonia after persistent pulmonary fistula. Sleeve resectin of the segmental bronchi were performed in 7 patients, of whom one patient died from anastmotic dehiscence due to empyema thoracis induced by MRSA, another died suddenly from pulmonary infarction one month after operation. Two causes of 3 hospital deaths could not be anticipated and there was no relation with bronchoplastic procedure. Reconstructive surgery in the peripheral bronchi should be indicated for patients with central early cancer, low grade malignancy of the lung and sometimes patients with hypolung function.

Aged↗
PubMed1991

[Prognosis and survival of pT1N2 lung carcinoma undergoing pulmonary resection and mediastinal lymph node dissection].

In the past 15 years, mediastinal lymph node dissection in conjunction with pulmonary resection was performed on 39 pT1N2 patients at Tokyo Metropolitan Komagome Hospital. The patients consisted of 4 histological cell types: 26 adenocarcinomas, 5 epidermoid carcinomas, 4 large cell carcinomas and 4 small cell carcinomas. The absolute five-year survival rate for pT1 N2 patients undergoing curative resection was 52.7% which was better than that of patients with stage II non-small cell carcinoma surgically resected during the same period. This finding suggests that pT1N2 group is a special entity among pN2 lung carcinoma, that shows better survival rate than less advanced patients with respect to pathological stage (stage II).

Adult↗
PubMed1991

[A case of carcinoma of the esophagus involving the trachea undergoing anterior mediastinal tracheostomy with pedicled omental wrapping].

A 62-year-old male who complained of dysphagia, body weight loss and hoarseness was admitted to our hospital. Chest x-ray film disclosed right superior mediastinal mass compressing membranous portion of trachea. Esophageal fiberscope revealed carcinoma of cervical esophagus. Bronchofiberscope revealed the paralysis of right recurrent laryngeal nerve and the invasion of esophageal cancer to tracheal membranous portion from the 5th tracheal ring to the 12th. The cancer also invaded the right lobe of thyroid which was shown by echogram. Operation was performed. On dissecting the cervical region, it was found that the tumor invaded both sides of the trachea so that tracheal reconstruction could not be done without injuring left recurrent laryngeal nerve. Sternotomy was added. Anterior mediastinal tracheostomy was done after laryngeal resection with total thoracic esophagectomy and tracheal resection leaving 5 rings long cartilage from carina. The trachea was wrapped with pedicled omentum. Post-operative course was uneventful. This procedure helps to increase blood supply to the tracheal anastomosis and turns to advantage in preventing infectious extension around trachea to mediastinum as well as tracheal compression to major vessels.

Esophageal Neoplasms↗
PubMed1990

[Incidence and clinical significance of the esophageal branches originating from the bronchial artery].

The authors investigated the incidence and extent of angiographic visualization of the esophageal branches originating from the bronchial arteries. Approximately 20% of 371 patients showed considerable blood flow to the esophagus. The left bronchial artery more often gives rise to the esophageal branches. Esophageal complications have been experienced in 8 cases following bronchial artery infusion of Mitomycin C for pulmonary carcinoma. Complications tend to occur in cases showing marked opacification of the esophageal veins or in those which a lesion locates in the peripheral portion of the lung. It is imperative to pay attention to esophageal branches of the bronchial artery in interventional angiography.

Bronchial Arteries↗
PubMed1989

Expression of epidermal growth factor receptors in four histologic cell types of lung cancer.

Lung cancer tissues from 68 patients were examined for epidermal growth factor (EGF) receptor levels and EGF receptor gene copy numbers. Histologic cell types of these lung cancer tissues included squamous-cell carcinoma (n = 30), adenocarcinoma (n = 28), large-cell carcinoma (n = 4), and small-cell carcinoma (n = 6). Tissues of squamous-cell carcinoma exhibited exceptionally high 125I-EGF binding activity, and those of small-cell carcinoma showed no EGF binding activity. Southern blot hybridization analysis revealed EGF receptor gene amplification in the squamous-cell carcinomas with high EGF binding activity. The EGF receptor levels in squamous-cell carcinomas and adenocarcinomas were compared with their pathological staging grouping and pathological findings, including degree of differentiation, diameter of tumor, and lymph node metastasis. However, unlike previous reports on breast and bladder cancers, there was no obvious correlation between these pathological characteristics and the EGF receptor levels of lung cancer.

Adenocarcinoma↗
PubMed1989

Depressant effect of magnesium on early afterdepolarizations and triggered activity induced by cesium, quinidine, and 4-aminopyridine in canine cardiac Purkinje fibers.

Magnesium chloride has been shown to terminate torsades de pointes in some patients with the acquired long QT syndrome. The mechanism for this effect is unknown. Recently early afterdepolarizations (EADs) and triggered activity (TA) have been proposed as causes of torsades de pointes. The purpose of the present study was to examine whether magnesium suppressed EADs that were initiated in vitro by different agents and if so its mechanism of action. TA arising from EADs was induced by quinidine (1 to 4 mumol/L, n = 5) at high temperature (38.5 to 40 degrees C), cesium chloride (5 to 12 mmol/L, n = 6), and 4-aminopyridine (1.5 to 5 mmol/L, n = 7) in canine cardiac Purkinje fibers superfused with modified Tyrode's solution (KCI = 2.7 mmol/L). MgCl2 (2 to 7 mmol/L) reversibly abolished TA and suppressed EADs. Tetrodotoxin (TTX; 1 to 5 mumol/L) also abolished TA elicited by 4-aminopyridine (n = 6). We then examined the effects of MgCl2, TTX, and verapamil on depolarization-induced automaticity by means of a single sucrose gap technique to gain insight into the mechanism of action of magnesium. MgCl2 (5 mmol/L) abolished automaticity arising from membrane potentials more negative than -70 mV and prolonged the spontaneous cycle length at less negative membrane potentials. The effects of TTX (1 to 5 mumol/L) resembled those of MgCl2. Verapamil (1 mumol/L) prolonged the cycle length of the initial automatic response at high levels of membrane potential and progressively reduced the amplitude of the subsequent automatic potentials. It abolished automaticity arising from less negative membrane potentials.(ABSTRACT TRUNCATED AT 250 WORDS)

4-Aminopyridine↗
PubMed1988

Evaluation of the malignant grade of thymoma by morphometric analysis.

To determine the histologic grade of malignancy of thymoma, the nuclear areas of epithelial cells of 42 thymomas, 14 thymic hyperplasias, and ten normal thymuses were measured by morphometry and the results were compared with the extent of disease, association with myasthenia gravis (MG), and histologic subtypes of the thymomas. The nuclei of epithelial cells of thymomas were significantly larger than those of both of thymic hyperplasias and normal thymuses (P less than 0.01). The nuclei of epithelial cells of invasive thymomas were significantly larger than those of noninvasive ones (P less than 0.001). In the noninvasive group, the nuclei of epithelial cells of thymomas associated with MG were significantly larger than those without MG (P less than 0.02), and were similar to those of invasive thymomas. These results confirm that invasive thymomas are morphometrically malignant tumors, and suggest that noninvasive thymomas associated with MG might have malignant potential.

Adolescent↗
PubMed1988

Contraction-excitation feedback in the atria: a cause of changes in refractoriness.

The purpose of this study was to investigate the immediate effects of an increase in atrial pressure on atrial refractoriness by determining the relation between the atrial pressure and effective refractory period of the atrium. In 21 open chest anesthetized dogs, after the blocking of atrioventricular (AV) conduction by formalin injection, the left atrium and left ventricle were paced sequentially at a fixed cycle length of 300 ms. The AV interval was varied from 0 to 280 ms in 20 ms steps during the recording of aortic and left atrial pressures and refractory period of the left atrium. Mean left atrial pressure was lowest (8.0 +/- 0.4 mm Hg, all values mean +/- SEM) at an AV interval of 47 +/- 3 ms, when refractory period was 135.5 +/- 2.6 ms. Mean left atrial pressure was highest (13.3 +/- 0.5 mm Hg) at an AV interval of 147 +/- 5 ms, when refractory period was 137.9 +/- 2.4 ms (p less than 0.01). Left atrial diameter measured by echocardiography increased from 33.7 +/- 1.8 mm at an AV interval of 47 ms to 37.8 +/- 1.8 mm (p less than 0.01, n = 10) at an AV interval of 147 ms, and mean aortic pressure decreased from 109 +/- 4 to 101 +/- 4 mm Hg. After surgical decentralization of vagal and sympathetic innervation to eliminate baroreflex influence on refractoriness, left atrial refractory period prolonged from 141.6 +/- 3.4 to 145.4 +/- 3.4 ms (p less than 0.01) when mean left atrial pressure increased from 9.5 +/- 0.4 to 15.2 +/- 0.6 mm Hg. A similar relation was noted between right atrial pressure and right atrial refractory period (n = 10) and between left atrial pressure and refractory period of the interatrial septum (n = 12). In six chronically instrumented conscious dogs, left atrial refractory period prolonged from 116.3 +/- 2.3 to 124.2 +/- 1.7 ms (p less than 0.01) when mean left atrial pressure increased from 4.0 +/- 0.8 to 9.0 +/- 0.3 mm Hg. Therefore, an increase in atrial pressure lengthens refractory period of both atria and the interatrial septum in anesthetized and conscious dogs.

Animals↗
PubMed1988

Supersensitivity to acetylcholine of canine sinus and AV nodes after parasympathetic denervation.

Supersensitivity of the sinus (SAN) and atrioventricular (AVN) nodes to acetylcholine (ACh) after parasympathetic denervation has not been demonstrated conclusively. In this study, we denervated the SAN and AVN by surgically removing parasympathetic ganglia and painting the area with phenol. Sham dogs underwent thoracotomy without denervation. Four to 9 days later, vagal denervation was proved by supramaximal bilateral vagal stimulation, which prolonged the sinus cycle length (SCL) only 32 +/- 7% (mean +/- SE) and the AVN conduction time (AH interval) 15 +/- 7% in denervated dogs. We tested for supersensitivity by obtaining dose-response curves to ACh (1 ml, 10(-8.0) to 10(-4.0) M in 10(0.5) steps) infused over 15 s into the sinus nodal and posterior septal arteries in open chest-denervated (Den) dogs and in sham-operated (Sham) dogs that were anesthetized with alpha-chloralose. ACh concentration (Log[ACh], M) required to prolong SCL 50, 100, and 300% was -5.7 +/- 0.1, -5.6 +/- 0.1, and -5.4 +/- 0.1 in 10 Sham dogs vs. -6.4 +/- 0.1 (P less than 0.001), -6.3 +/- 0.1 (P less than 0.001) and -6.1 +/- 0.1 (P less than 0.001) in 11 Den dogs. ACh concentration necessary to produce second degree and complete AV block was -5.7 +/- 0.1 and -5.3 +/- 0.1 in 11 Sham dogs vs. -6.3 +/- 0.1 (P less than 0.001) and -5.8 +/- 0.1 (P less than 0.01) in 10 Den dogs. Because significantly lower doses of ACh prolonged SCL or produced AV block in Den compared with Sham dogs, we conclude that dogs with vagally denervated SAN and AVN develop a supersensitive response to ACh.

Acetylcholine↗
PubMed1988

Magnesium suppression of early afterdepolarizations and ventricular tachyarrhythmias induced by cesium in dogs.

The mechanism by which magnesium therapy suppresses some ventricular tachyarrhythmias characterized by a prolonged QT interval (e.g., torsades de pointes) is unknown. Since early afterdepolarizations have been proposed as a cause of the long QT syndrome and the related ventricular tachyarrhythmias, we hypothesized that magnesium therapy would suppress both the early afterdepolarizations and the ventricular arrhythmias. The present study was performed to test that hypothesis. Using monophasic action potentials (MAP) recorded with a contact electrode from the right ventricular endocardium to demonstrate early afterdepolarizations, cesium chloride (168 mg/kg iv) was administered before, during, and 1 to 2 hr after discontinuation of a magnesium infusion (1 to 2 mg/kg/min for 20 to 30 min). Before magnesium infusion, cesium induced early afterdepolarizations that were 49.7 +/- 1.6% (mean +/- SE) of the amplitude of the corresponding monophasic action potential. The amplitude of the early afterdepolarization decreased to 31.2 +/- 3.8% of the MAP amplitude during magnesium infusion (p less than .003) and increased to 48.0 +/- 4.0% 1 to 2 hr after termination of the magnesium infusion (p less than .003). Cesium induced sustained monomorphic ventricular tachycardia, torsades de pointes, or ventricular fibrillation in 12 of 13 dogs before magnesium infusion, and in eight of 11 dogs 1 to 2 hr after stopping infusion, but in only three of 13 dogs during magnesium infusion. Cesium prolonged the corrected QT interval from 338 +/- 16 msec (control) to 387 +/- 14 msec before (p less than .003), 356 +/- 12 msec during (p less than .003), and 406 +/- 16 msec after stopping the magnesium infusion (p less than .003).(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1988

Adenoid cystic carcinoma of the trachea and main-stem bronchus. A clinical, histopathologic, and immunohistochemical study.

Twelve cases of adenoid cystic carcinoma of the trachea and main-stem bronchus were histologically analyzed, and the results were examined with reference to the growth pattern of the tumor and the prognosis. The tumors were histologically classified into tubular, cribriform, and solid subtypes. Three histologic grades were established: grade I, tumors with tubular and cribriform subtypes but without solid subtype; grade II, tumors with tubular and cribriform subtypes in which the solid subtype comprised less than 20% of the area; grade III, tumors in which the solid subtype comprised more than 20% of the area. Three gross infiltrating types were established: type I, entirely intraluminal; type II, predominantly intraluminal; type III, predominantly extraluminal. In most cases histologic grade correlated with gross tumor type; that is, grades, I, II, and III were grossly types I, II, and III, respectively. The tumors infiltrating along the tracheobronchial wall were of the tubular or cribriform subtype, but not of the solid subtype. In two patients who died of distant metastasis, the histologic studies revealed the solid subtype. Immunohistochemical analysis demonstrated that the tubular subtype was the most differentiated form and the solid subtype, the most undifferentiated form. The histologic subtype of adenoid cystic carcinoma of the tracheobronchial tree was an important factor in the growth pattern of the tumor and the prognosis.

Adult↗
PubMed1987

Quantitative analysis of regional wall motion in dogs in situ--characteristics of end-systolic pressure-length relation.

Regional wall motion was analyzed to deduce the muscle property unique to regional contractile states. End-systolic pressure length relations were evaluated under global changes in a contractile state, under selective intracoronary administration of inotropic agents to produce regional hypo- or hyper-kinesis, and before and after extension of size of the ischemia. Linearity of the end-systolic pressure-length relation was confirmed in each perturbation; however, the behavior of this relation with regard to changes in the slope and X-axis intercept differed among the three situations. When the contractile state was altered globally by intravenous administration of inotropic agents such as dobutamine and propranolol, the slope of the end-systolic pressure-length relation changed in a manner similar to that seen with the pressure-volume relation or stress-strain relation, with no significant changes in the X-axis intercept. Namely, the level of global cardiac function determined the slope of the end-systolic pressure length relation. When regional hypokinesis was produced pharmacologically by selective intracoronary infusion of lidocaine, the X-axis intercept moved rightward, depending on the degree of regional hypokinesis. Expansion in the size of the ischemic area also shifted the X-axis intercept rightward. The latter two phenomena suggested that the hypokinetic segments were stretched by the surrounding intact myocardium. Accordingly, end-systolic pressure-length relations provide useful information concerning the functional state of regional myocardium. The systolic properties of the regional myocardium rendered hypokinetic have to be quantified so as to include the total geometry of the heart.

Animals↗