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Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 1,423 records · Page 79Linked to original sources
PubMed1981

[Echocardiographic and non-gated computed tomographic findings of intrapericardial tumor and mediastinal tumor adjacent to the heart (author's transl)].

UNLABELLED: Echocardiographic and computed tomographic findings of a case of intrapericardial tumor are reported, and two other cases of mediastinal tumor are presented in a discussion of the differential diagnosis of intrapericardial from mediastinal tumors. CASE REPORT: A 7-year-old male complained of cough and dyspnea. Cardiomegaly had been pointed out at a mass X-ray examination about a month prior to the admission. Two-dimensional echocardiography revealed a massive anterior pericardial effusion and a fist-sized tumor with cystic structure. The tumor pushed the heart backward at the level of the aortic root. Non-gated computed tomography of the chest disclosed the size and location of the tumor, but failed to clarify the internal structure. The patient underwent successful removal of a tumor, 12 x 10 x 8 cm in size and 350 g in weight, originating from the left atrial wall. Histologically, the tumor was a fibrosarcomatous mesothelioma. Usually, an intrapericardial tumor is easily suspected by echocardiography by the presence of pericardial effusion, although there have been a few reports of intrapericardial tumors without pericardial effusion. Echocardiographic diagnosis of the intrapericardial tumor is difficult in such cases. Identification of the pericardium is necessary to diagnose whether a tumor is intra- or extrapericardial. This identification, however, is not always easy by echocardiography when the ultrasonic beams become tangent to the pericardium. The pericardium between the tumor and the heart could not be identified by echocardiography in our two cases of mediastinal tumor. Computed tomography is helpful in diagnosing the size and location of a mediastinal tumor.

Adult↗
PubMed1981

[Effects of antiarrhythmic agents on ventricular arrhythmias following myocardial infarct induced with glass beads in dogs (author's transl)].

Ventricular arrhythmias due to myocardial infarct were produced in 14 dogs, and the antiarrhytmic effects of quinidine (Qd), lidocaine (Lid), aprindine (Apr), and dl-propranolol (dl-Prop) were investigated. While recording the blood pressure and lead II ECG, a coronary cannula was inserted into a coronary orifice via the left carotid artery and a glass bead (diameter, 1.5 mm) was flushed into the left coronary artery. Beads were found at the descending branches in 12 and circumflex branches in 2 out of 14 gods, at autopsy. Using a telemetry system to record the lead II ECG of conscious, non-restricted dogs, the antiarrhythmic effects of Qd, Lid, Apr, and dl-Prop on ventricular arrhythmias 24 hours after coronary occlusion were compared. Apr and dl-Prop were about three times more potent than Qd and Lid. Although the durations of the antiarrhythmic effects of Apr, Lid, and dl-Prop were 20 to 30 min, that of Qd lasted longer. Since stable ventricular arrhythmias can be obtained by surgical intervention and the antiarrhythmic effects of standard compounds with glass beads can be used to study antiarrhythmic effects.

Animals↗
PubMed1980

Magnetic circular dichroism on oxygen complexes of hemoproteins: correlation between magnetic circular dichroism magnitude and electronic structures of oxygen complexes.

Magnetic circular dichroism (MCD) and natural circular dichroism (CD) spectra are reported for horseradish peroxidase Compounds II and III, and kangaroo myoglobin Compound II at pH values of 8.5 and 4.9. These compounds exhibited MCD spectra of apparent Faraday A term both in the Soret and Q regions, except for myoglobin compounds in the Soret region where intrinsic temperature dependence showed large contribution from Faraday C terms. Comparison of these data with the MCD spectra of the dioxygen complexes of hemoglobin (myoglobin) and cytochrome P-450 revealed that the magnitude of the apparent Faraday A term trough at the Q0-0 bands decreased in the order of O2 complexes of hemoglobin (myoglobin) ([theta]M not equal to 16) greater than horseradish peroxidase Compound III ([theta]M not equal to 8) greater than O2 complex of cytochrome P-450 ([theta]M not equal to 4). The [theta]M values of the oxygen complex of cytochrome P-450 is similar to those observed for the compounds II of horseradish peroxidase and kangaroo myoglobin. From these observations it was concluded that the magnitude of MCD, especially the trough depth of the Q0-0 band, has direct correlation to the electronic states of the oxygen complexes of the hemoproteins. The implication of the findings was discussed in terms of the iron electronic structures perturbed by the axial ligation.

Animals↗
PubMed1980

Cardiac output by dye dilution using a left carotid loop in conscious rats.

By a modified dye dilution method using a simple dichromatic densitometer, cardiac output (CO) in conscious rats was determined. Under anesthesia, a carotid loop was made in the left carotid artery with a polyethylene tube (PE50) and exteriorized. A sensor of the densitometer was set at the center of the carotid loop. Indocyanine green dye solution was injected into the right atrium via the jugular vein. CO was calculated from the dye dilution curve obtained. In the conscious state (6 hours after ether anesthesia),CO in normotensive, spontaneously and DOC/saline hypertensive rats was determined without affecting blood pressure and heart rate. However, CO in the pentobarbital or urethane anesthetized rats was decreased with other hemodynamic changes. The validity of this method was confirmed with a hydraulic model system and in anesthetized open-chest cats using an electromagnetic flowmetry. From these studies, it was concluded that the modifed dye dilution method for measuring CO in conscious rats was reliable and useful for hemodynamic studies in hypertensive rats.

Animals↗
PubMed1980

Extra RNAs of von Magnus particles of influenza virus cause reduction of particular polymerase genes.

Extra RNAs, or RNA species other than eight gene segments, in von Magnus particles of the influenza virus WSN strain were studied by polyacrylamide gel electrophoresis and oligonucleotide mapping. From the original virus stock, various cloned stocks were obtained, each giving rise to a characteristic set of extra RNAs. One cloned virus stock contained a large number of von Magnus particles. The RNA pattern was characterized by two prominent extra RNAs (X1 and X2) and a decrease in the content of two polymerase genes, P1 and P2. Segregation of the two extra RNAs was carried out by coinfection of cells with a von Magnus particle and infectious virions. The results showed that the presence of one of the extra RNAs (X2) was associated with a reduction in the amount of the P1 gene and that the presence of the other extra RNA (X1) was associated with a reduction in the amount of the P2 gene. Oligonucleotide mapping showed that both extra RNAs, X1 and X2, were derived from the P1 gene. The results suggested that an extra RNA did not necessarily cause the reduction of the progenitor polymerase gene, but might cause the reduction of another polymerase gene.

DNA-Directed RNA Polymerases↗
PubMed1980

Clinical and hormonal aspects of the watery diarrhea-hypokalemia-achlorhydria (WDHA) syndrome due to vasoactive intestinal polypeptide (VIP)-producing tumor.

Three patients with the watery diarrhea-hypokalemia-achlorhydria (WDHA) syndrome were studied. All had watery diarrhea, hypokalemia and hypercalcemia. Plasma vasoactive intestinal polypeptide (VIP) levels determined by radioimmunoassay were markedly elevated in these patients, indicating that they had VIP-producing tumors. Plasma VIP levels determined serially after the operation indicate that its determination is useful in estimating the effect of a treatment. As for multiple endocrine neoplasia type 1 (MEN1), two out of the three cases belonged to this category. Patient 1 had a brother with insulinoma, and in case 2, even though there was no family history, the autopsy revealed not only multiple tumors of the pancreas but also pituitary adenomas, chief cell hyperplasia of the parathyroid glands, thyroid adenomas and adrenocortical adenomas. VIP and other hormones in the tumors as well as in the plasma were examined extensively in these cases. In case 1, VIP, gastrin and calcitonin were produced in the tumor and only plasma VIP levels were elevated. In case 2, with multiple tumors, tumor 1 produced VIP, glucagon pancreatic polypeptide, gastrin and calcitonin, and tumor 2, VIP, pancreatic polypeptide, gastrin and beta-melanocyte stimulating hormone. In this case, plasma VIP, pancreatic polypeptide and glucagon levels were elevated. In case 3, VIP and calcitonin were produced in the tumor, and plasma VIP and calcitonin levels were elevated. These results indicate that (1) VIP is a good tumor marker for the WDHA syndrome due to VIP-producing tumors; (2) patients with the WDHA syndrome are sometimes associated with MEN1; and (3) VIP-producing tumors are multiple hormone-producing tumors, and VIP predominantly elevated in the plasma results in the WDHA syndrome, although other hormones such as pancreatic polypeptide, glucagon and calcitonin are sometimes found to be elevated in plasma without contributing to the clinical features.

Achlorhydria↗