Search PubMed⌕ Search

Biomedical subjects

Y Amano

Publications and source records attributed to Y Amano.

At least 145 records · Page 8Linked to original sources
PubMed1987

[Mitral valve disease and atrial natriuretic polypeptide].

We compared plasma ANP concentration and atrial content of ANP as well as plasma concentrations of other fluid regulating hormones and renal function between the MVR group (n = 12) and the non MVR group (n = 14) during open heart surgery. Preoperatively there was no significant difference in plasma ADH and ACTH between two groups, however plasma ANP was significantly higher in the MVR group (96.9 +/- 16.2 pg/ml) than in the non MVR group (22.8 +/- 8.6 pg/ml) (p less than 0.01). During extracorporeal circulation ANP was at a low level because of aortic clamping. Tissue concentration of ANP in right appendages was higher (p less than 0.02) in the MVR group (61.8 +/- 11.8 nmol/g wet weight) (n = 6) than that in the non MVR group (14.9 +/- 3.1 nmol/g wel weight) (n = 15). Also, concentration in left appendages of the MVR group (50.0 +/- 10.4 nmol/g wet weight) (n = 4) was higher than that in right appendages of the non MVR group (p less than 0.05). From these results it may be concluded that increased secretion of ANP is elicited by left atrial load and probably playing an important role on circulating blood volume regulation.

Aldosterone↗
PubMed1986

Arterial chemoembolization with cisplatin microcapsules.

Cisplatin (CDDP) was microcapsulated with ethylcellulose. Sustained release of CDDP from the microcapsule, particularly non-protein-bound CDDP, which should have antitumour activity, was demonstrated by an in vitro test. Using a bioassay, it was proven that the biological activity of CDDP was not affected by the microencapsulation process. When CDDP-mc were infused into the maxillary artery of patients with carcinoma of the maxillary sinus or oral cavity, the CDDP level in the circulating blood was significantly lower than that of the patients given non-encapsulated CDDP intravenously. However, a significantly higher CDDP concentration in tumour tissue was found in patients treated with CDDP-mc. These results suggest that selective arterial infusion of CDDP-mc could exert intensive topical antitumour effects on lesions through microinfarction effects, and prolonged drug release, with minimum systemic side effects.

Cellulose↗
PubMed1986

Isolation of smooth muscle excitatory substances from chicken rectum and their characterization.

Acid-acetone extracts of the chicken rectum were subjected to chromatographic and electrophoretic separation, and two new smooth muscle-contracting substances close to purity were obtained. One of them showed chemical and biological characteristics similar to those of substance P, but it was clearly different from substance P on the basis of chromatographic and electrophoretic criteria. Thus, one could be a peptide belonging to the substance P-family. The other substance was also shown to be of peptide nature since its biological activity was destroyed by chymotrypsin and carboxypeptidase A. Parallel bioassay on the two tissues of the longitudinal muscle of the guinea-pig ileum and the isolated whole chick rectum revealed that none of the peptides such as substance P, physalaemin, kassinin, eledoisin, bradykinin and angiotensin II could be a candidate for the active substance. The biological activity was not antagonized by naloxone, suggesting that the substance was a peptide other than the opioid compounds. The molecular sizes estimated by gel filtration are 1300 for the substance P-like peptide and 1600 for the other substance. The possible physiological roles of the two substances as an excitatory non-adrenergic, non-cholinergic transmitter were discussed.

Animals↗
PubMed1986

Epidemiology of rotavirus in Guayaquil, Ecuador.

Detection of rotavirus by electron microscopy was conducted with fecal specimens from 1,722 infants and young children with acute diarrhea, during a 41-month survey from April 1978 through December 1981 in Guayaquil, Ecuador; 376 of these specimens (21.8%) were positive. The detection rate was higher during the dry season (May to November; 25.2%) than during the rainy season (December to April; 14.7%). When rotaviruses isolated from 59 patients hospitalized with diarrhea (from April 1979 to July 1981) were subjected to genome RNA analysis by polyacrylamide gel electrophoresis, a single dominant electropherotype was found with other less common electropherotypes. An atypical rotavirus with a unique property was also found.

Adenoviridae Infections↗
PubMed1986

[Immunological investigation of late cerebral vasospasm in subarachnoid hemorrhage. (Part 1)].

Although the occurrence of so-called late cerebral vasospasm after subarachnoid hemorrhage (SAH) due to ruptured cerebral aneurysm is well-known, its etiology still remains obscure. This time, the authors investigated the etiology by immunological research. Following results were obtained, Out of 13 cases of SAH due to ruptured cerebral aneurysm, angiographic cerebral vasospasm was observed in 9 cases. In these 9 cases, tendency of decrease in the number of peripheral blood T lymphocytes, depression on the lymphocyte PHA (phytohemagglutinin) and Con A (concanavalin A) response, and tuberculin anergy were found. These results suggest that the depression of cell-mediated immunity function might induce the occurrence of so-called late cerebral vasospasm after SAH.

Adult↗
PubMed1985

Microcapsule chemoembolization for head and neck cancer.

Cisplatin (CDDP) was microencapsulated with ethylcellulose, and microcapsules (CDDP-mc) were infused into the maxillary arteries of patients with various head and neck carcinomas. We then found that the CDDP level in the circulating blood was significantly lower than that in patients administrated intravenous non-excapsulated CDDP. However, significantly high concentrations of CDDP were found in the tissues of patients treated with CDDP-mc. Our results suggest that selective arterial infusions of CDDP-mc can exert an intensive topical antitumor effect through microinfarction of malignant tissues. The prolonged release of drug from the microcapsules has also been associated with minimal systemic side effects.

Aged↗
PubMed1985

Purification and properties of two endo-1,4-beta-xylanases from Irpex lacteus (Polyporus tulipiferae).

Two different endo-1,4-beta-xylanases [1,4-beta-D-xylan xylanohydrolases, EC 3.2.1.8], named Xylanases I and III, were purified to homogeneity by gel filtration and ion exchange column chromatography from Driselase, a commercial enzyme preparation from Irpex lacteus (Polyporus tulipiferae). The purified enzymes were found to be homogeneous on polyacrylamide disc electrophoresis and their specific activities toward xylan were increased approximately 28.7 and 19.8 times, respectively. The activities of each enzyme were considerably inhibited by Hg2+, Ag+, and Mn2+. Their molecular weights were estimated to be approximately 38,000 and 62,000 by gel filtration and sodium dodecyl sulfate (SDS)-polyacrylamide electrophoresis, respectively. Their carbohydrate contents were 2.5% and 8.0% as glucose, and their amino acid composition patterns resembled each other, showing high contents of acidic amino acids, serine, threonine, alanine, and glycine. Both enzymes were most active at pH 6.0 but Xylanase I was more stable as to pH. Their optimum temperatures were 60 degrees C and 70 degrees C, respectively. Xylanase I split up to 34.5% of larchwood xylan whereas Xylanase III split only 18.9% of it. The products with the former were mainly xylose (X1), xylobiose (X2), and xylotriose (X3), whereas X2 and X3 were the main products with the latter. Both enzymes did not hydrolyze X2. Xylanase I produced almost equal quantities of X1 and X2 from X3, while Xylanase III did not attack this substrate. Both enzymes showed no activity toward glycans, other than xylan, such as starch, pachyman and Avicel (microcrystalline cellulose), except the almost one twentieth activity of Xylanase III toward sodium carboxymethyl cellulose (CMC).

Amino Acids↗
PubMed1985

The nasal local antibody production of rats against respiratory infections.

For better understanding the nasal defense mechanism against infection, an experiment on bacterial inhalation was performed using rats with and without artificial nasal obstructions. Local antibodies in the nasal cavity may exert a wide defensive influence on inhaled pathogens. Their production can be affected by nasal obstruction.

Aerosols↗
PubMed1985

A human atypical rotavirus found in an Ecuador infant with diarrhea.

One strain of atypical rotavirus, morphologically indistinguishable from known rotaviruses but lacking the common group antigen of typical rotavirus detectable by an enzyme-linked immunosorbent assay (ELISA), was isolated from one of 152 Ecuadorian infants with acute rotavirus gastroenteritis. The genome analysis by polyacrylamide gel electrophoresis revealed a unique RNA pattern clearly distinct from that of typical rotaviruses.

Diarrhea, Infantile↗