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Biomedical subjects

A Amano

Publications and source records attributed to A Amano.

At least 109 records · Page 6Linked to original sources
PubMed1990

Evaluation of the depth sensitivity of tissue reflectance spectrophotometry in gingival measurement.

Tissue reflectance spectrophotometry (TRS) can estimate hemoglobin concentration (Hb index) and oxygen saturation of hemoglobin (apparent SO2) in tissues. Reflectance spectra were measured in a gingiva-model and in human gingival biopsies by TRS. The gingiva-model was composed of human red cells and white gel in a cuvette placed on a black or white surface. The distance from the bottom surface of the cuvette to the optical probe was decreased from 5.0 to 0.5 mm. The Hb index in the gingiva-model on the black surface was constant before decreasing at less than a 3.0 mm distance. However, the Hb index in the gingiva-model on the white surface showed a decrease at less than a 1.5 mm distance. Apparent SO2 was constant at more than a 1.0 mm distance. Reflectance spectra were measured from human gingival tissue preparations, by slicing them off with microtome and making them less thick each time. Changes in reflectance spectra were observed in less than 1.0-1.5 mm thick specimens. These results suggest that the sensitivity in TRS measurement may exist within 1.0-1.5 mm from the gingival surface, and the limit of depth at which the TRS can measure may be within 3.0 mm.

Gingiva↗
PubMed1990

[A case report of bilateral free internal mammary artery bypass grafting reoperation--spontaneous resolution of stenotic LAD graft one year after revascularization].

We experienced a coronary artery bypass reoperation utilizing bilateral free internal mammary artery (IMA) grafts for a 68 year old male with unstable angina due to graft occlusion. Although post-operative early graftgraphy showed LAD graft stenosis, it resolved completely at the second graftgraphy one year after the operation. Recently in situ IMA grafting has become a standard method for coronary artery revascularization because of its long term high patency rate. On the other hand, free IMA grafting has been rarely tried in our country. Though there has been a few reports of the growth and enlargement of in situ IMA graft, similar events in free IMA graft are rare and not found in the literature. We feel our case of spontaneous resolution of free IMA graft stenosis is unique and worth reporting.

Aged↗
PubMed1989

Familial aortic dissection: a report of rare family cluster.

Acute aortic dissection occurred in three of four siblings without Marfan syndrome. All of them were successfully treated by operation and remain well 6-42 months after operation. Their mother died suddenly in another hospital of acute aortic dissection. All her siblings were dead and cardiovascular disease was suspected in all of them.

Acute Disease↗
PubMed1988

Relationship between enzyme activities involved in oxygen metabolism and oxygen tolerance in black-pigmented Bacteroides.

In this study, the relationship between enzyme activities involved in oxygen metabolism and the degrees of oxygen tolerance in black-pigmented Bacteroides was investigated. All strains of Bacteroides tested possessed the activities of NADH oxidase and superoxide dismutase, whereas the activities of catalase and peroxidases were not detected in the cell-free extracts. There were relatively high correlations between oxygen tolerance and activity of either NADH oxidase or superoxide dismutase. The activity of superoxide dismutase showed a higher correlation with oxygen tolerance than with that of NADH oxidase. Among the species tested, Bacteroides gingivalis showed the highest activities of both the enzymes and was the most tolerant in the presence of oxygen. Furthermore, the activities of these two enzymes increased during aeration of the oxygen-tolerant strain Bacteroides gingivalis 381, but not in the oxygen-sensitive strain Bacteroides denticola ATCC 33185. These results suggest that superoxide dismutase and NADH oxidase might be important for protection of black-pigmented Bacteroides against the toxic effect of oxygen.

Bacteroides↗
PubMed1987

Substrate specificity of fucosyltransferase purified from human parotid saliva.

The purified fucosyltransferase from human parotid saliva was shown to transfer fucose from GDP-fucose onto the oligosaccharide chains containing the Gal beta 1----3GlcNAc or Gal beta 1----4GlcNAc/Glc sequences. Competition studies between asialotransferrin and either lacto-N-fucopentaose 1 or 2'-fucosyllactose provided evidence that both the substrates competed for a common enzyme active site. These results suggest that the fucosyltransferase activities for the three acceptors may be catalyzed by the same enzyme.

Acetylglucosamine↗
PubMed1986

Isolation and some properties of exohemagglutinin from the culture medium of Bacteroides gingivalis 381.

Exohemagglutinin was found in the culture medium of Bacteroides gingivalis 381. Exohemagglutinin was purified 3,150-fold from culture fluid by ultracentrifugation followed by gel filtration on Sepharose CL-4B and by affinity chromatography on arginine-agarose. Examination of the final preparation of exohemagglutinin by biochemical analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the isolated exohemagglutinin contained three major proteins but not a detectable lipopolysaccharide. Hemagglutination inhibition experiments showed that the activity of exohemagglutinin was inhibited by L-arginine and the arginine-containing peptides, although the activity was unaffected by the sugars tested. Some protein and glycoproteins that were examined also exhibited the inhibitory activity. When the bovine submaxillary mucin was chemically modified by beta-elimination and bovine serum albumin was modified by guanidination, the inhibitory effects on hemagglutination were significantly enhanced. These results suggest that the hemagglutination of the isolated exohemagglutinin may be involved in arginine residues as components of ligand-binding sites on erythrocytes.

Bacterial Proteins↗
PubMed1979

Use of curves for prediction of maternal blood levels of placenta-specific substances for diagnosis of placental function.

Maternal blood levels of cystine aminopeptidase (CAP), human placental lactogen (HPL) and beta 1 glycoprotein (SP-1) were predicted and evaluated using the expressions and their charts developed by us to help diagnosis of placental function in women of the third trimester of pregnancy. This study was conducted on the assumption that these placenta-originating substances as markers would behave similarly to the previously reported heat-stable alkaline phosphatase (HSAP). The results realized the following features: (1) CAP, HPL and SP-1, like HSAP, had their normal ranges of values too wide to be based on for diagnosing placental function in general, but it was confirmed that on the individual basis these marker substances could develop adequate "prediction curves" for their values to come well answering to the test in the same way as with HSAP. (2) The expressions for predicted values revealed that these marker substances in their shift in the maternal blood had different critical points start of deviation from exponential rising. Particularly in abnormal pregnancy, their shifting patterns were often dissimilar to one another, with implications that impaired placental function could possibly be confirmed qualitatively by reference to the predicted curve for the values of either of the marker substances.

Aminopeptidases↗