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Biomedical subjects

T Nagano

Publications and source records attributed to T Nagano.

At least 325 records · Page 18Linked to original sources

Pulmonary vein blood flow velocity waveform--with special reference to pulmonary "systolic runoff" in patients with atrial septal defect.

In order to evaluate the magnitude of pulmonary "systolic runoff", we studied the pulmonary vein blood flow velocity waveform by positioning a catheter-tip velocity-pressure transducer into the extraparenchymal pulmonary vein just distal to the left atrium. We recorded blood flow velocity and pressure simultaneously, and subsequently identified the zero blood flow velocity with blood flow velocity level of the pulmonary artery in diastole. Patients with atrial septal defect were used as subjects because of the technical ease although the altered hemodynamics were present. Two kinds of flow velocity waveforms were consistently demonstrated. One was a waveform of two peaks with the first peak in late systole and the second peak in early diastole (n = 9). The other was a waveform of one peak with a summit near the end of systole (n = 5). On the assumption that the blood flow velocity waveform obtained with this method is roughly equivalent to the flow volume waveform, we initiated the second study. The area encompassed between the actual flow velocity waveform and the line of zero flow velocity was divided into two compartments, i.e., ventricular systole (S) and diastole (D). The ratios of the area in systole to the sum of the areas in systole and diastole, i.e., (S)/[S) + (D], which are analogous to the pulmonary "systolic runoff", were 0.45 +/- 0.07 (mean +/- SD, n = 13). This suggests that about 40% of the right ventricular stroke volume flows into the pulmonary veins, the left atrium and a portion of the right atrium through the atrial septal defect during ventricular systole.

Adolescent↗

Aspirin-induced asthma and nasal polyps.

Asthma, aspirin intolerance and nasal polyps form a triad of aspirin-induced asthma (AIA). Eighteen cases, 6 males and 12 females, who complained of asthma attacks and/or rhinorrhea after ingestion of non-steroidal anti-inflammatory drugs were encountered over several years. The mean age of onset was 32.1 for asthma and 25.4 for rhinitis. Asthma was found in all of the 18 cases and nasal polyps in 13 cases (72.2%). The polyps were recurrent and 7 patients had undergone polypectomies. Urticaria was seen in 44.4% and sinusitis diagnosed by X-ray in 81.8%. Sensitivity to at least one allergen was found in 7 out of 9 cases (77.8%) and 6 out of 11 cases (54.5%) gave results positive for RAST. Eosinophilia was seen in 14 out of 16 patients (87.5%). The pathogenesis of AIA is obscure but is probably related to inhibition of prostaglandin biosynthesis. We concluded that AIA is not a rare disease in Japan either, and the studies for eosinophilia may be useful for elucidation of the pathogenesis of AIA and nasal polyps.

Adult↗

[Studies on Campylobacter and Salmonella in feces of pregnant women and newborn infants].

Fecal cultures from five thousand four hundred and twenty-seven pregnant women, who were delivered at Osaka National Hospital from January 1, 1980 to December 31, 1984, were examined to detect intestinal Campylobacter and Salmonella during 30 and 36 gestational weeks. In addition, the feces of newborn infants were cultured three days after delivery to check for the presence of Campylobacter and Salmonella. During pregnancy, Campylobacter was detected in the feces of 116 women (2.14%), and Salmonella in 99 cases (1.82%). By administering antibiotics to the affected cases, the number of women whose fecal cultures were positive for Campylobacter and Salmonella at the time of delivery was reduced to 8 and 15, respectively. Neonatal fecal cultures revealed that Salmonella infection occurred in two among fifteen (13.33%) and Campylobacter infection in three among eleven (27.27%) infants whose mothers had been affected. These findings suggest the importance of adequate management for these bacterial infections during pregnancy and the perinatal period to prevent danger to the newborn.

Campylobacter fetus↗

The co-oxidation of ammonia to nitrite during the aerobic xanthine oxidase reaction.

The xanthine oxidase reaction causes a co-oxidation of NH3 to NO2-, which was inhibitable by superoxide dismutase, catalase, hydroxyl radical scavengers, or by the chelating agents, desferrioxamine or diethylene triaminepentaacetic acid. Hydroxylamine was oxidized to NO2- much more rapidly than was NH3, and in this case superoxide dismutase or the chelating agents inhibited but catalase or the HO. scavengers did not. Hydrazine was not detectably oxidized to NO2-, and NO2- was not oxidized to NO3-, by the xanthine oxidase reaction. These results are accommodated by a reaction scheme involving (a) the metal-catalyzed production of HO. from O2- + H2O2; (b) the oxidation of H3N to H2N. by OH.; (c) the coupling of H2N. with O2- to yield peroxylamine, which hydrolyzes to hydroxylamine plus H2O2; (d) the metal-catalyzed oxidation of HO-NH2 to (Formula: see text), which couples with O2- to yield (Formula: see text), which finally dehydrates to yield NO2-.

Ammonia↗

Multiple meningiomas in the posterior fossa.

A case of multiple meningiomas in the posterior fossa is reported. Computed tomography scans clearly demonstrated the tumors. They were removed completely and the patient was discharged without any neurological deficits. The clinical features are discussed and the pertinent literature is reviewed.

Cranial Fossa, Posterior↗

Superoxide radical from xanthine oxidase acting upon lumazine.

The univalent and divalent reductions of dioxygen were measured using lumazine as a low turnover substrate and both xanthine and acetaldehyde as high turnover substrates. These measurements were made in solutions equilibrated with air and with 100% O2. The univalent route of dioxygen reduction predominated with the low turnover substrate and was increased by raising pO2 and by lowering substrate concentration. These results support the view that electron egress from heavily reduced xanthine oxidase occurs by divalent transfers, while that from the partially reduced enzyme is by univalent transfers. Xanthine oxidase, acting as lumazine, is a convenient source of O2-.

Acetaldehyde↗