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Biomedical subjects

T Nakada

Publications and source records attributed to T Nakada.

At least 433 records · Page 24Linked to original sources

[A case of hemangioma of the heart].

A-74-year old woman who had suffered from anterior chest pain and palpitation was admitted to our hospital. The chest X-ray photograph showed that the heart was enlarged mildly. We found that the tumor lay in the mediastinum by the echocardiograph and was enhanced at the aortic phase of the radioisotope angiography. In order to obtain the histological specimen, she underwent exploratory thoracotomy. The tumor was diagnosed as a cavernous hemangioma. She has been asymptomatic over 1-year period. The RI angiography seemed to be useful to diagnose the hemangioma of the heart.

Aged↗

[Estimation of the filtration variables in the rat lung].

The filtration variables, filtration coefficient (K), perimicrovascular pressure (Ppmv) and reflection coefficient (sigma) were estimated independently in previous reports using the Starling Equation or the micropuncture method. We estimated these variables simultaneously. We measured filtration rate by a gravimetric method in isolated rat lung lobes in zone 1 conditions (alveolar pressure = 20 cmH2O) at two vascular pressures, Pvasc = 15 or 8 cmH2O and perfused the lobes with plasma containing a low or high concentration of protein. By extrapolating the log of the rate of weight gain to time = 0, we obtain the initial filtration rate. Assuming that protein filtered into perimicrovascular space only by convection, we substituted into the Starling Equation as follows: Q = K[(Pmv-Ppmv)-sigma 2 pi mv], where Pmv and pi mv are hydrostatic and plasma protein osmotic pressures in microvascular space. pi mv was estimated by Yamada's equation. We obtained K = 26.3 +/- 8.7 mg/(min.cmH2O.g), PPMV = 6.2 +/- 0.7 cmH2O, sigma = 0.46 +/- 0.07. The chief advantages of this method are that it does not require a separate estimation of isogravimetric pressure or a direct measurement of interstitial pressure, and that all variables are obtained simultaneously.

Animals↗

[Postoperative bronchopleural fistula--diagnostic significance of masked cases and results of early re-operation].

We studied recent-day cases of postoperative bronchopleural fistula from 1982 to 1985. And in 1985, postoperative chest X-ray films were intensively compared with previous ones. Radiological signs for bronchopleural fistula and/or alveolar fistula such as increases in air content and/or falls in air-fluid level of pleural space were seen in 11 (7.1%) of 155 pulmonary resection cases in 1985. Among them, 8 of these cases were confirmed as bronchopleural fistulas. So one half of cases with these radiological findings were bronchopleural fistulas. But 2 of these 8 cases were masked bronchopleural fistulas which were not recognizable by bronchofiberscope and soon or later, bronchopleural fistulas developed which were recognizable by bronchofiberscope. For differential diagnosis between the bronchopleural fistula and alveolar fistula, serial chest X-ray films which was compared with previous one, were useful. In masked bronchopleural fistula cases, abnormal findings as mentioned above were seen more than three times, but in alveolar fistula cases were seen less than two times. On the bronchoscopic examination, bronchopleural fistulas were mainly located at the side of the residual lobe on the stump. Bronchopleural fistula cases which were re-operated for re-amputation, re-suture, and coverage of the stump within 48 hours, were all cured. So we concluded early re-operation is the best choice for bronchopleural fistula patient, because of short administration, no cosmetical problems and no disadvantage for lung function.

Bronchial Fistula↗

[Clinicopathologic assessment of primary thymic carcinoma based on seven cases].

In order to study clinicopathologic characteristics of thymic carcinomas, seven patients experienced in our department were reviewed in this paper; 6 patients underwent thoracotomy and one did not receive surgical treatment. Among 6 who received operation, the tumor was resected totally in 3, subtotally in one, partially in one. One patient underwent exploratory thoracotomy. There have been no distinctive clinical features including clinical symptoms and radiographical findings from invasive thymomas in 7 primary thymic carcinomas, however, in these malignant tumors there have been no tumor-associated disorders not infrequently observed in thymomas. Postoperatively, distant metastasis was common in patients with thymic carcinomas, even though the primary tumor was resected totally in the operation. However, one patient with squamous cell carcinoma of the thymus who underwent subtotal tumor resection followed by radiotherapy and chemotherapy are surviving over 6 years postoperatively. Intensive treatment including pre- and postoperative radiation, tumor resection and postoperative chemotherapy is absolutely necessary for thymic carcinoma. Histologically, there were 4 squamous cell carcinomas and 3 large cell carcinomas. One of 3 large cell carcinomas showed squamous cell differentiation histologically. Two of 4 squamous cell carcinomas demonstrated concomitant entity of residual thymus tissue as well as thymoma in one specimen. However, further studies are necessary to determine precise etiology and tumor characteristics of thymic carcinoma.

Adult↗

[Histopathological studies of endomyocardial biopsy on the children with Kawasaki disease].

Since there has been many reports on the coronary artery lesions in the patients with Kawasaki disease, but only a few reports on histopathological investigation employing endomyocardial biopsy, histopathological study was performed in eighteen children of Kawasaki disease with coronary artery lesions and eighteen children of Kawasaki disease with intact coronary artery, aged from one year and ten months to fourteen years. There were twenty males and sixteen females. Comparing Kawasaki disease who had coronary artery lesions with those not, there was no striking difference in histologic findings. Kawasaki disease without coronary artery lesions revealed myocellular hypertrophy, degeneration of myocytes, disarray, interstitial fibrosis and endocardial changes in 44%, 61%, 11% and 44%, respectively. Among Kawasaki disease who had coronary artery lesions, children with coronary artery stenosis showed a higher incidence of histological abnormalities than those with coronary artery aneurysm. Some cases of Kawasaki disease were recognized to have significant myocardial abnormalities even in three to six years after onset, which seemed to persist whether or not they would have coronary artery lesions. Since Kawasaki disease who would have myocardial damages might have the potential for developing cardiomyopathy, careful attention should be payed to myocardial lesions as well as sequelae of coronary artery lesions.

Adolescent↗

[The effect of bilateral vagal blockade on respiration].

Although respiratory regulation has been extensively studied so far, the relation between the vagal nerves and respiratory reflex in man is still open to controversy. This paper describes the effect of bilateral vagal blockade on respiration. 1) Dyspnea due to unilateral bronchial occlusion. This type of dyspnea is caused by extreme depression of the intrabronchial pressure on the occluded side and is accompanied by a rapid increase in respiratory rate and a rapid decrease in tidal volume. This type of dyspnea is relieved by blockade of the ipsilateral cervical vagal nerve. 2) Animal experiments on bilateral lung transplantation, heart-lung transplantation and bilateral cervical vagal blockade. The respiratory changes induced by CO2 inhalation, low O2 inhalation, respiratory stimulant. Loss of blood or fever stimulation in the manipulated dogs were compared with those in normal controls. CO2 inhalation alone produced differences in the respiratory rates and tidal volumes between the two groups. The tidal volume increase under CO2 inhalation was suppressed by the inflation reflex but other afferent vagal nerves seemed to be closely associated with the increased respiratory rate. 3) Vagal nerve reflex in humans. Blockade of the bilateral cervical vagal nerves in an awake state resulted in irregular PETCO2 in cases that had been stable and sometimes produced a pattern of Cheyne-Stokes respiration. Inhalation of 5% CO2 restored the regular rhythm of respiration and enhanced the response to CO2. When subjected to bilateral vagal blockade in an awake state, the patient expressed an unbearbly uneasy dyspneic sensation as if he were pulled into a bottomless abyss. This was demonstrated by the unstable FRC level.

Animals↗

[Study of postoperative bronchopleural fistulas--analysis of factors related to bronchopleural fistulas].

Postoperative bronchopleural fistulas, although reduced in incidence, remain as a grave complication of pulmonary resection. In our department, cases of lung cancer have been rapidly increasing and those of infectious diseases have been decreasing. In light of this trend, the causes of bronchopleural fistulas may have changed, and thus we studied recent cases of postoperative bronchopleural fistulas from 1982 to 1986. Bronchopleural fistulas were seen in 5 (7.8%) of 64 cases of inflammatory diseases and in 19 (4%) of 481 cases of lung cancer. In lung cancer, bronchopleural fistulas were more frequently seen with advanced cases, especially in cases of residual tumors on the stump and in cases of intrathoracic use of anticancer drugs. The highest incidences of bronchopleural fistulas were seen with right pneumonectomy and right lower lobectomy. Bronchoscopic examination showed bronchopleural fistulas to be mainly located on the stump beside the residual lobe. When Sweet's procedure is employed, this is the point with the most tension on the stump. Clinical and retrospective analysis of preoperative data revealed the following factors to be significantly higher in cases of bronchopleural fistulas than in cases of non-bronchopleural fistulas: fever, use of steroid hormone, Haemophilus influenzae in sputum, elevation of erythrocyte sedimentation ratio and anemia. Such analysis of postoperative data showed the following factors to be significant: fever, use of steroid hormone, leucocytosis, tracheostomy and bronchoscopy for sputum suction.

Adolescent↗

[Arterial switch operation for simple transposition of the great arteries in infancy].

Five infants (22-42 days of life) underwent arterial switch operation for simple transposition of the great arteries under deep hypothermic cardio-pulmonary bypass. Three babies required prostaglandin E1 infusion to keep ductus arteriosus opened widely before surgery. Balloon atrioseptostomy was necessary in 0-10 days of life in all babies because of poor condition. Left to right ventricular peak pressure ratio ranged from 0.75 to 0.86, preoperatively. Four of the five survived the operation, and one died of coronary insufficiency because of kinking of the implanted coronary artery. Hypothermic circulatory arrest was used in three (38-41 minutes). Aortic cross clamp time was 70-100 minutes, and cold crystalloid cardioplegia was given only one time just after aortic clamp in 3 babies. Single dose of cardioplegia protected left ventricular muscle well in babies with transposition of the great arteries as same as multiple dose method used in those with ventricular septal defect.

Humans↗

[A case of reexpansion pulmonary edema during thoracotomy].

A case of reexpansion pulmonary edema during thoracotomy is presented. A high edema fluid-plasma protein concentration ratio suggested an increase in pulmonary vascular permeability. A marked increase in the percentages of polymorphonuclear leukocytes (PMN) and high concentration of PMN-elastase in edema fluid suggested activated PMN-mediated vascular endothelial injury, which caused an increase in permeability. Edema fluid and plasma contained high concentrations of Thromboxane B2 and 6-keto-PGF1 alpha at the stage of increased permeability. This suggested these chemical mediators participated in the mechanisms of increased permeability in reexpansion pulmonary edema.

Adult↗

Comparison of single dose versus multiple dose crystalloid cardioplegia in neonate. Experimental study with neonatal rabbits from birth to 2 days of age.

Thirty-five isolated hearts from newborn rabbits (aged birth to 2 days) were subjected to 120 minutes of ischemia at 15 degrees C with high potassium crystalloid cardioplegia. They were divided into four groups according to the method of cardioplegic administration: group C (preischemic control, n = 9), group S (single dose, n = 10), group M-1 (multiple dose, infused every 40 minutes, n = 7), and group M-2 (multiple dose, infused every 20 minutes, n = 9). After 30 minutes of reperfusion, the heart rate, coronary flow, creatine kinase release, percent water content, and myocardial ultrastructural scores for mitochondrial damage and intracellular edema were compared among the four groups. All of these parameters except coronary flow were significantly poorer in group M-2 than in groups C and S (p less than 0.05). The mitochondrial damage and intracellular edema scores were significantly poorer in group M-1 than in group C (p less than 0.05). No significant differences in these two scores were seen between group S and group C and between group S and group M-1. These results indicate that the single dose method of administering crystalloid cardioplegia may provide better myocardial protection than the multiple dose method in the neonate.

Animals↗

[Diagnosis of rejection using immunologic probe in lung allotransplantation].

We attempted to establish the method of early diagnosis of rejection in lung transplantation using dog, rat and monkey experimental models. Orthotopic left lung allotransplantation was performed in these animals and lymphocytes from peripheral blood (PBL) and/or bronchoalveolar lavage fluid (BALF) were examined as a probe of rejection monitoring. The recipient dog showed a decreased response of PBL to PHA and an increased spontaneous blastogenesis (SB) at the period undergoing rejection which were confirmed by blood samples taken within 2 days before sacrifice of the animal. In rat lung transplantation, 2 groups of animal pair were used; WKA to F344, and WKY to F344. The former recipient rejected the graft within 5 days postoperatively and the latter rejected within 2 weeks after the operation. In both groups parameters for detection of rejection included lymphocyte count, SB and T cell subsets of PBL and BALF lymphocyte. Lymphocyte SB of BALF from lung transplant reflected early stage of rejection and preceded the changes in PBL. This seemed to be useful for early diagnosis of lung allograft rejection. In monkey experiment, BALF lymphocyte from the transplanted lung seemed to well reflect the grade of rejection when compared total cell count and differential cell count with histologic findings of the graft, though the number of this experiment was small.

Animals↗

[Present status of lung transplantation and heart-lung transplantation].

On the basis of development of the immunosuppressive drugs such as cyclosporine since 1981, many successful cases have been reported on clinical lung and heart-lung transplantations. A principal disease for a single lung transplantation is pulmonary fibrosis. Obstructive lung disease and bilateral pulmonary sepsis such as cystic fibrosis and bronchiectasis are now considered to be done double lung transplantation. On the other hand, heart-lung transplantations have been performed not only on primary pulmonary hypertension and Eisenmenger's syndrome but also on restrictive and/or obstructive lung disease. Today's subjects on lung and heart-lung transplantations are as follows 1) The establishment of preservation method of transplant organs. 2) Development of an appropriate technique of monitoring for the rejected lungs. 3) Assessment and improvement of bronchial anastomotic healing. 4) Investigation of the causal factors on reimplantation response and obliterative bronchitis. Long-term survivals have been reported in both lung and heart-lung transplantation. Therefore, many attempts have been increasingly made in order to obtain the heart beating cadaver donors in Japan. But experimental study on the unsolved problems of transplantation should be continuously carried out for successful clinical lung and heart-lung transplantation.

Graft Rejection↗

Purification and analysis of the structure of alpha-galactosidase from Escherichia coli.

Alpha-Galactosidase, the product of the melA gene, was purified from a strain of Escherichia coli harboring a plasmid carrying melA, which over-produced the alpha-galactosidase. An apparent molecular weight was determined to be 50 kDa. The amino acid composition of this enzyme was determined. The result indicates that this enzyme is a hydrophilic and acidic protein. We have subjected the purified enzyme to 20 cycles of N-terminal sequence analysis. This verified the translation start site of the melA gene and the predicted N-terminal sequence.

Amino Acid Sequence↗

Phospholipid profile of the human brain: 31P NMR spectroscopic study.

Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, sphingomyelin, and ethanolamine plasmalogen represent the six most abundant phospholipids of brain cell membrane. The ratio of the phospholipid contents (phospholipid profile) of the brain is remarkably consistent under various metabolic conditions and alteration of the phospholipid profile is believed to reflect changes in the membrane system. We describe here a simple but sensitive method to analyze the phospholipid profile of the human brain utilizing the acidified chloroform-methanol lipid extraction method of Folch et al. and 31P nuclear magnetic resonance (NMR) spectroscopy. Unique regional phospholipid profiles were consistently obtained. Although the large chemical-shift anisotropy of the 31P confined to rigid structures such as the cell membrane precludes direct observation of phospholipid profiles in living tissue, a reflection of the membrane phospholipid profiles can nevertheless be obtained by studying "NMR visible" water soluble intermediate metabolites of membrane phospholipids in vivo.

Adult↗

Fluorine-19 NMR imaging of glucose metabolism.

Metabolic imaging reflecting glucose metabolism in the glycolytic and aldose reductase sorbitol (ARS) pathways was performed noninvasively in rat using fluorinated glucose analogs, 2-fluoro-2-deoxy-D-glucose (2-FDG) or 3-fluoro-3-deoxy-D-glucose (3-FDG), and fluorine-19 (19F) nuclear magnetic resonance (NMR) imaging. 19F images of 2-FDG-6-phosphate, a main metabolite of 2-FDG in the glycolytic pathway, showed high glucose utilization in the brain, spinal cord, and heart. Images of 3-fluoro-3-deoxy-D-sorbitol (3-FDSL), a main metabolite of 3-FDG in the ARS pathway, demonstrated the heterogeneous nature of the spatial distribution of aldose reductase activities, being highest in the brain and lens. The extremely low toxicity of 3-FDG indicates promise for clinical application of 3-FDG NMR imaging.

Animals↗

Changes of vasoactive substances following embolization for renal cell carcinoma.

Renal arterial embolization and subsequent nephrectomy or nephrectomy alone were performed in 34 patients with renal cell carcinoma. Renal arterial embolization caused a blood pressure elevation concomitant with an increase in plasma renin activity (PRA), urinary aldosterone excretion or urinary prostaglandin (PGE2) excretion. Subsequent nephrectomy normalized hypertension and reduced the levels of these vasoactive substances. There were significant relationships between the increase in mean blood pressure and the increase in PRA, the increment in mean blood pressure and the increment in urinary aldosterone excretion, and the increase in PRA and increase in log urinary PGE2 excretion following embolization. These evidences suggest that enhancement of the renin-angiotensin-aldosterone system participates in the development of hypertension following embolization, and increased PRA may play an important role in the release of urinary PGE2.

Aged↗