Biomedical subjects

T Nakada

Publications and source records attributed to T Nakada.

At least 397 records · Page 22Linked to original sources

PubMed1990

Uneventful delivery following series of successive treatments for virilized Cushing syndrome due to adrenocortical carcinoma.

A twenty-one-year-old virilized woman with Cushing syndrome due to a huge adrenocortical carcinoma was successively treated with trilostane (3 beta-hydroxysteroid dehydrogenase inhibitor), subsequent adrenalectomy, and postoperative cis-platinum. Clinical or biochemical abnormalities peculiar to Cushing syndrome gradually subsided, and three and one-half years after the adrenal surgery, the patient delivered a normal female infant. This study points out some of the clinical and biochemical responses of each treatment.

Adrenal Cortex Neoplasms↗

PubMed1990

Membrane fatty acid composition shows delta-6-desaturase abnormalities in Alzheimer's disease.

Brain membrane phospholipid fatty acid composition is investigated in Alzheimer's disease using fresh pathologically proven autopsy material. The most striking abnormalities in Alzheimer brains compared to age-matched controls are found in the n - 6 line of polyunsaturated fatty acids (PUFA) showing an elevation of 18:2 (n - 6) associated with a reduction of 20:4 (n - 6) and 22:4 (n - 6). The findings strongly indicate abnormalities in delta 6-desaturation. The decrease in 22:6 (n - 3) also supports delta 6-desaturase abnormalities. Alteration in PUFA desaturation/elongation processes and resultant membrane abnormalities may play a key role in the pathogenesis of Alzheimer's disease.

Aged↗

PubMed1990

Vasopressin and atrial natriuretic peptide release in cardiopulmonary denervated dogs.

To assess the effect of cardiopulmonary denervation on the release of arginine vasopressin (AVP) and atrial natriuretic peptide (ANP), either hemorrhage (1.0 ml.kg-1.min-1, for 40 min) or an infusion of 3% dextran in lactated Ringer solution (RL) (3% dextran in RL, 1.0 ml.kg-1.min-1, for 40 min) was carried out in chronic cardiopulmonary denervated (CPD, n = 7) and sham-operated (SO, n = 7) dogs under anesthesia. Plasma AVP increased significantly in both groups during hemorrhage, but its rise was significantly attenuated in CPD dogs. Plasma ANP decreased similarly during hemorrhage in both groups. An infusion of 3% dextran in RL decreased significantly plasma AVP during its whole period in SO dogs, but AVP release was only suppressed in the late period in SO dogs. Plasma ANP increased significantly during its infusion in both groups. These results indicate that cardiopulmonary denervation may attenuate the release of AVP in response to either hemorrhage or blood volume expansion but may not affect the release of ANP in response to the blood volume change. Moreover, a large increase in plasma ANP may attenuate the release of AVP.

Animals↗

PubMed1990

Persistent high lactate level as a sensitive MR spectroscopy indicator of completed infarction.

Serial proton (1H) and phosphorus-31 (31P) magnetic resonance (MR) spectroscopy of cerebral infarction was performed in rats to assess the sensitivity of these techniques for use in clinical cerebral infarction. In this experimental chronic infarction model, 31P spectroscopy tended to return to a "normal" pattern within 24 hours after induction of infarction in spite of pathologically proven completed infarction and, therefore, appeared not to be sensitive enough for clinical application. On the other hand, proton spectroscopy invariably showed persistent high lactate levels and was capable of distinguishing completed infarction from reperfused recovered brain. Persistent high lactate levels appear to be a good MR spectroscopic indicator of completed infarction.

Animals↗

PubMed1990

[Adrenal regeneration hypertension--effects of vascular connective tissue protein and plasma corticosterone on hypertension in rats with adrenal regeneration hypertension].

In young rats consuming 1% NaCl drinking solution, unilateral nephrectomy and bilateral adrenal enucleation caused a hypertension. Plasma corticosterone concentration in hypertensive rats was not significantly higher than that of normotensive control rats in early hypertensive or chronic hypertensive stage. At the end of experiment, each rat received an intravenous injection of 0.4 microCi/g of 3H-lysine and was sacrificed 2 hours after the injection. Incorporation of 3H-lysine into collagen or elastin of the mesenteric artery and heart in hypertensive rats was greater than that of normotensive rats. Administration of phenoxybenzamine hydrochloride lower the blood pressure of hypertensive rats and reduced the incorporation of 3H-lysine into collagen and elastin of the mesenteric artery and heart. From these findings, increased protein synthesis of collagen and elastin in hypertensive rats appears to play an important role for the maintenance of adrenal regeneration hypertension.

Adrenal Glands↗

PubMed1990

[Study of the effects of dopamine hydrochloride on alpha 1-adrenoceptors in rat kidney].

We studied the number and affinity of catecholamine receptors in SD rat kidney by radioreceptor technique. The following conclusions were obtained: 1) By using 3H-prazosin, the numbers of alpha 1-receptor (Bmax) in rat renal cortex were greater than those in rat kidney medulla. As for affinity (Kd), the significance was not recognized between the two. Bmax of the rat renal cortex to 3H-prazosin binding was 96.1 fmol/mg protein, and Kd was 0.17 nM, and for the rat renal medullar these values were 44.5 fmol/mg protein and 0.13 nM, respectively. 2) By measurement of D1-receptor using 3H-SKF38393 in the rat renal cortex in the Scatchard plot analysis, positive cooperativity was observed under the low concentration of hot ligand which was less than 1 nM. But at the concentration of hot ligand over 1 nM, the plots showed a straight line. Bmax of the rat renal cortex to 3H-SKF38393 was 2.5 pmol/mg protein and Kd was 5.3 nM. 3) Based on displacement by dopamine for 3H-prazosin binding to rat renal cortex, it was surmised that high concentration of dopamine had an affinity to alpha 1-adrenoceptors. 4) There was no change in the Kd and Bmax of alpha 1-receptor in the rat renal cortex after incubation of samples with low concentration of dopamine. However, in the case of high concentration of dopamine, a remarkable decrease of the affinity (Kd) of alpha 1-adrenoceptor was observed.

Animals↗

PubMed1990

Purification and characterization of two forms of maltotetraose-forming amylase from Pseudomonas stutzeri.

Pseudomonas stutzeri MO-19 produced two active forms of extracellular maltotetraose-forming amylase. Both forms, G4-1 and G4-2, were purified to electrophoretic homogeneity. The molecular masses of G4(-1) and G4(-2) were 57 kd and 46 kd by SDS-polyacrylamide gel electrophoresis, respectively. An identical N-terminal sequence up to 20 amino acid residues and similar amino acid compositions were obtained from both forms, but different C-terminal amino acids, leucine from G4(-1) and alanine from G4(-2), were released by carboxypeptidase Y. By in vitro incubation with a culture supernatant containing protease activity, G4(-1) was converted into G4(-2) without any loss of the amylase activity. It was concluded that G4(-2) was a product derived by the limited proteolysis of G4(-1), and that the proteolysis occurred in the C-terminal region of G4-1. G4-2 was more thermostable than G4(-1), and had a 20-fold higher Michaelis constant value for glycogen, which was 50 mg/ml against 2.3 mg/ml of G4(-1). G4(-1) adsorbed onto raw starch granules while G4(-2) did not.

Amino Acid Sequence↗

PubMed1990

[A case of extramedullary plasmacytoma of the mesenteric lymph nodes].

Reported here is a extremely rare case of extramedullary plasmacytoma which occurred in the mesenteric lymph nodes and could be diagnosed before operation. The ultrasound examination showed a multilobular mass, the CT examination a multilobular, homogeneous mass, and angiography a hypervascular lesion. M-protein decreased after operation.

Humans↗

PubMed1990

[Analysis of patients with resected small-size (less than or equal to 2 cm in diameter) peripheral type lung cancer lesions].

From 1953 to 1985, a total of 1289 patients with primary carcinoma of the lung underwent surgical treatment. Of these 116 (8.9%) had small-sized (less than or equal to 2 cm in diameter) peripheral type lung cancer lesions. This study had three purposes: 1) to analyse how small-sized lung cancer lesions were detected; 2) to evaluate the reliability of diagnosis of small-sized cancer lesions; and 3) to evaluate pre- and post-prognostic factors of such patients compared with patients with peripheral type lung cancer lesions 2.1-3 cm in diameter. Of the 115 patients with small-sized lung cancer lesions were detected in the course of mass surveys. Cytopathological diagnosis in 75% of the patients resulted from transbronchial brushing cytology. The 5-year survival rate of patients who underwent resection of small-sized peripheral type lung cancer lesions was 70% (2.1-3 cm; 52%). Various factors such as histologic type, nodal involvement, pleural involvement, pathological stage, and success of the operation were shown to significantly affect survival. A comparison of two groups, i.e., those with lesions smaller than 2 cm in diameter and those with lesions 2.1-3 cm in diameter, showed the rate of lymph node metastasis to be significantly different. Of the patients with peripheral lung cancer lesions smaller than 2 cm who underwent surgery, 21% had peribronchial, hilar, or mediastinal lymph node metastasis. On the other hand, lymph node metastasis was seen in 43% of cases with peripheral lung cancer lesions 2.1-3 cm in diameter who underwent surgery.

Humans↗

PubMed1990

[A useful combination chemotherapy of cisplatin and etoposide in mediastinal yolk sac tumor].

A 28-year-old male was referred to our hospital because of chest pain and dry cough. Chest x-ray film revealed a tumor mass in the anterior mediastinum indicating invasion into the chest wall and upper lobe of right lung. No tumor was found in the testis. Serum level of alpha-fetoprotein (AFP) was 6,400 ng/ml. Percutaneous biopsy of the tumor suggested yolk sac tumor. The patient was treated with a combination chemotherapy schedule including 30 mg of cisplatin (CDDP) i.v. on Days 1, 2, 3, 4, and 5 and 150 mg of etoposide on Days 1, 2, and 3 as one course therapy. Two courses were employed. Partial response was achieved followed by successful resection of the tumor. This case indicated that a combination chemotherapy CDDP and etoposide combined with surgery could play an active role increasing long-term survival rates in mediastinal yolk sac tumors.

Adult↗

PubMed1990

[A case of thoracic neurilemoma with neurilemomas of the upper limb and sacrum].

A 64-year-old male was admitted in February 24, 1988 because of an abnormal shadow on chest X-ray. The tumor in the thoracic wall was removed at the thoracotomy and histology showed neurilemoma. Aspiration biopsy of tumors on the left upper limb and sacrum revealed the typical histopathologic appearance of neurilemomas. The possibility of malignant transformation and sequential appearance of tumors in patients with a neurilemoma indicates that complete resection and thorough follow-up examination are important.

Humans↗

PubMed1990

[A study of lung cancer with presence of pleural effusion at the time of thoracotomy--cytologic evaluation of a relatively small amount of pleural effusion and prognosis after removal].

The cytologic evaluation of a relatively small amount of pleural effusion in lung cancer at the time of thoracotomy has not been previously considered, and prognosis after removal has not been clarified. In order to clarify these points, 99 cases of removed lung cancer with presence of pleural effusion at the time of thoracotomy were examined following cytology. Our study was conducted with regard to the amount and nature of pleural effusion, pleural effusion cytology, tumor development and its relation to prognosis. On the basis of this study a formula was developed relating the occurrence rate of cytologically positive pleural effusion with the development of tumor employing multivariate analysis, specifically the multiple regression analysis. 21% of these cases showed cytologically positive pleural effusion, indicating an absence of its correlation to the amount of pleural effusion; the conducting of cytology regardless of the amount of pleural effusion was found to be significant in determining the precise stage. The occurrence rate of cytologically positive squamous cell carcinoma was significantly few compared with those in other cell types. Regarding the pleural effusion of a relatively small amount, the prognosis after removal showed a relatively high three-year survival rate of 32% for those cases with negative pleural metastasis despite the positive showing of pleural effusion cytology, indicating the viability of surgery. From the occurrence rate of cytologically positive pleural effusion (Y) and the degree of pleural metastasis (X1)/the degree of pleural invasion (X2)/the degree of lymph nodes metastasis (X3), the following formula was obtained employing multiple regression analysis: Y = 0.344X1 + 0.050X2 + 0.034X3 + 0.075 (proportion 0.840).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

[A case of mediastinal yolk sac tumor successfully treated with chemotherapy and surgery].

A 28-year-old man was admitted due to increasing respiratory symptoms. X-ray examination of the chest showed a tumor mass in the anterior mediastinum with possible invasion into the chest wall and upper lobe of right lung. No tumor was found in the testis. Serum alpha-fetoprotein (AFP) concentration was 6400 ng/ml. Serum levels of CEA and HCG were within normal limits. Percutaneous biopsy of the tumor strongly suggested yolk sac tumor with an evidence of AFP by an immunoenzyme labelling technique. The serum AFP rapidly decreased after two courses of combination chemotherapy. En bloc resection of the tumor was successfully performed and third chemotherapy was added. Mediastinal yolk sac tumors should be treated with combination chemotherapy and surgical resection.

Adult↗

PubMed1990

[Surgical experience of bronchogenic early squamous cell carcinoma detected by sputum cytology in lung cancer screening].

Eighty-one patients of roentgenologically occult lung cancer (all men, and squamous cell carcinoma) were detected by sputum cytology in lung cancer screening of "Miyagi Program". Sixty-seven patients were resected surgically, and sixty-four of them underwent absolutely curative resection. In fifty-six patients, carcinoma did not penetrate the bronchial wall, and all of them were free from lymph node involvement. In eleven patients, carcinoma penetrated the bronchial wall, and three of them were proved to have lymph node involvement. For that reason, carcinoma which did not penetrate the bronchial wall and was free from lymph node involvement, was defined as early squamous cell carcinoma. Fourty-two early squamous cell carcinoma were located on segmental or more proximal bronchi, but twelve were located on subsegmental or more peripheral bronchi. Five-year survival of fifty-six patients with early squamous cell carcinoma were 91.8%, seven of fifty-six early squamous cell carcinoma patients were multicentric, which were detected synchronously in four cases, postoperatively in two cases, and both synchronously and postoperatively in one case. Two of three postoperatively detected cases were resected surgically and alive without cancer. These results indicate the validity of surgical treatment for roentgenologically occult squamous cell carcinoma. As the most serious prognostic problem is multicentricity, careful localization of primary lesion and postoperative intensive follow-up should be considered.

Aged↗

PubMed1990

[Clinical investigation on childhood HCM; long-term follow-up study with special reference to electrophysiology, histopathology by endomyocardial biopsy and ambulatory and exercise electrocardiography].

In order to determine the prognosis and risk factors of childhood HCM, we investigated clinical parameters, such as the age of onset, symptoms and signs related to HCM, dysrhythmias and ST-T and changes by Holter ECG and exercise ECG, electrophysiological study and histopathological study by endomyocardial biopsy. Heart murmur was the commonest sign although only one patient revealed a significant left ventricular outflow tract gradient of more than 20 mmHg. The peak age of patients diagnosed as having HCM was 10 to 15 years. The major ECG manifestations of our series showed specific findings and in some cases ECG changed remarkably during the follow-up period. The diagnosis of apical hypertrophy should be made with caution in childhood. Holter ECG seemed to be indispensable for the follow-up of childhood HCM because Holter ECG in our patients manifested such significant findings as ventricular premature contractions or couplets or ST depression. The degree of clinical severity did not always correlate with the histopathological severity obtained by endomyocardial biopsy. As HCM in childhood is heterogeneous and multifaceted, there is no one therapy, and prognosis and proper treatment with close observation should be carried out in each individual case.

Adolescent↗

PubMed1989

Intrauterine fetal brain NMR spectroscopy: 1H and 31P studies in rats.

Fetal brain metabolism was investigated in utero noninvasively using multinuclear nuclear magnetic resonance spectroscopy in rats at two representative prenatal stages: early (17-18 days) and late (20-21 days) stages. Phosphorus-31 (31P) spectroscopy revealed that phosphocreatine is significantly lower in the early stage and increases to the level of early neonates by the late prenatal stage. Intracellular pH at the early stage was found to be strikingly high (7.52 +/- 0.21) and decreased to a level similar to that of neonates by the late stage (7.29 +/- 0.07). Phosphomonoester levels at both stages were similar to the values reported for early neonates. Water-suppressed proton (1H) spectroscopy demonstrated a distinctive in vivo fetal brain spectral pattern characterized by low levels of N-acetyl aspartate and high levels of taurine. High-resolution proton spectroscopy and homonuclear chemical-shift correlate spectroscopy of brain perchloric acid extracts confirmed these in vivo findings. In vitro 31P spectroscopy of acidified chloroform methanol extracts showed the characteristic membrane phospholipid profiles of fetal brain. The phosphatidylethanolamine (PE)-to-phosphatidylcholine (PC) ratio (PE/PC) did not show significant changes between the two stages at 0.40 +/- 0.11, a value similar to that of early neonates.

Animals↗

PubMed1989

Cortical spectroscopy: localized spectroscopy of the cerebral cortex in rats.

A method for obtaining nuclear magnetic resonance (NMR) spectroscopic signals confined to the cerebral cortex in rat using a cortical coil constructed based on the principles of the zig-zag coil is described. We obtained 31P NMR spectra of normal cerebral cortex and cold-induced injured cortex using this cortical coil. The cortical coil clearly demonstrated an increase in inorganic phosphate (Pi) confirmed to cerebral cortex which, by contrast, the conventional planar surface coil failed to detect. There are significant metabolic differences between cortex and subcortical tissues. The technique described here, capable of assessing cortical metabolism in vivo without contamination by the underlying tissue, has substantial application to studies of cerebral metabolism.

Animals↗

PubMed1989

In vivo pharmacokinetics of aldose reductase inhibitors: 3-fluoro-3-deoxy-D-glucose NMR studies in rat brains.

Direct quantification of the inhibitory effects of orally administered drugs (sorbinil, cyclandelate and sulindac) on aldose reductase activities in rat brains was performed non-invasively using the 3-fluoro-3-deoxy-D-glucose (3-FDG) 19F NMR spectroscopic technique. Quantitative data obtained directly from the target organ (brain) allowed for unprecedentedly accurate analysis of drug effects in the brain in vivo. Sorbinil, a potent aldose reductase inhibitor, exhibited a classic monophasic organ response, whereas cyclandelate and sulindac showed biphasic suppression patterns. The latter indicate that there are metabolites of these drugs which possess aldose reductase inhibitory activities. The estimated potency of aldose reductase inhibition for each of the three drugs in this study was significantly discrepant from the in vitro studies indicating the complicated nature of the bioavailability of a pharmaceutical agent in vivo, especially where pharmacologically active metabolites of a given drug are involved. Our method allows for a direct quantitative assay and hence the most reliable technique for evaluating aldose reductase inhibitory activities in the target organ.

Aldehyde Reductase↗