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Biomedical subjects

Y Aoyagi

Publications and source records attributed to Y Aoyagi.

At least 181 records · Page 10Linked to original sources

The reactivity of alpha-1-antitrypsin with Lens culinaris agglutinin and its usefulness in the diagnosis of neoplastic diseases of the liver.

The reactivity of alpha-1-antitrypsin (AAT) with Lens culinaris agglutinin (LCA) was studied by crossed immuno-affinity electrophoresis of the sera of 246 subjects from 6 groups (acute virus hepatitis, chronic hepatitis, liver cirrhosis, hepatocellular carcinoma (HCC), carcinoma metastatic to the liver and normal controls). Two species of AAT (LCA-reactive and -nonreactive species) were detected on crossed immuno-affinity electrophoresis in a gel containing LCA. The percentages of LCA-reactive species of AAT in neoplastic diseases of the liver were significantly higher than those in benign liver diseases and normal controls. There was no correlation between the percentage of LCA-reactive species of AAT and serum AAT concentration in any group. Furthermore, in studying 15 pairs of serum samples before and after the subsequent development of HCC, the percentage of LCA-reactive species of AAT after HCC occurrence was significantly higher than that before, although there was no statistically significant difference between the serum AAT concentration before and after development of the disease. The latter 15 patients were all of the normal protease inhibitor phenotype (PiMM) and no change in phenotype was observed before and after the development of HCC. The results indicate that measurement of the reactivity of AAT with LCA can be a useful marker for the diagnosis of HCC and carcinoma metastatic to the liver, especially when serum concentrations of alpha-foetoprotein or other tumour markers are within the normal ranges.

Carcinoma, Hepatocellular↗

Close topographical relationship in alpha foetoprotein (AFP) between a lens culinaris binding glycan and the epitope recognized by AFP-reactive monoclonal antibody, 18H4.

Monoclonal antibodies 18H4 and 19F12 against alpha-foetoprotein (AFP) were examined by enzyme immunoassay for binding to two forms of AFP that were separated on the basis of the reactivity with lentil lectin (LCA). LCA-binding and LCA non-binding AFP, coated on a solid phase, reacted with 18H4 but reactivity with the LCA-binding species was inhibited by 60% following pretreatment of the AFP with LCA. The lectin was a very poor inhibitor of binding of 18H4 to the AFP which did not interact with LCA. In an alternative binding assay, a polyclonal anti-AFP coated solid phase was reacted with beta-galactosidase-labelled 18H4. Pre-treatment with LCA of the LCA-reactive AFP gave 56% inhibition of binding of conjugated 18H4 while little inhibition was achieved with the LCA-nonreactive AFP component. These findings show that the epitope recognised by 18H4 is distinct from the glycan sequence that is reactive with LCA. However, the LCA-binding oligosaccharides occur in close proximity to the 18H4 epitope in the native AFP.

Antibodies, Monoclonal↗

Contribution of whole-body protein synthesis to basal metabolism in layer and broiler chickens.

The effect of starvation on whole-body protein synthesis and on the contribution of protein synthesis to basal metabolic rate was investigated in young chickens (Expt 1). Strain differences between layer and broiler chickens in whole-body protein synthesis and degradation rates were examined when the birds were starved (Expt 2). In Expt 1, 15-d-old White Leghorn male chickens were used, while in Expt 2 Hubbard (broiler) and White Leghorn (layer) male chickens at 14 d of age were used. They were starved for 4 d, and heat production was determined by carcass analysis after 2 and 4 d of starvation. Whole-body protein synthesis rates were measured on 0, 2 and 4 d of starvation (Expt 1), and on 0 and 4 d of starvation (Expt 2). The results showed that starving reduced whole-body protein synthesis in terms of fractional synthesis rate and the amount synthesized. Whole-body protein degradation was increased by starvation both in terms of fractional synthesis rate and the amount degraded on a per kg body-weight basis. Reduced fractional synthesis rate of protein in the whole body was accounted for by reductions in both protein synthesis per unit RNA and RNA:protein ratio. In the fed state, whole-body protein synthesis and degradation rates, whether expressed as fractional rates or amounts per unit body-weight, tended to be higher in layer than in broiler chickens. In the starved state, the difference in the rate of protein synthesis between the two strains virtually disappeared, while the degradation rates were higher in layer than in broiler birds.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Nutritional Physiological Phenomena↗

[Diagnostic evaluation of ischemic heart disease by X-ray computed tomography and magnetic resonance imaging].

To assess the usefulness of X-ray computed tomography (CT) and magnetic resonance imaging (MRI) in detecting and evaluating ischemic heart disease, conventional and enhanced CT were performed for 180 patients (150 with transmural infarction, 12 with subendocardial infarction, and 18 with angina pectoris). MRI examinations were performed for 38 patients (31 with transmural infarction, three with subendocardial infarction, and four with angina pectoris). With enhanced CT, two findings in the myocardium were direct evidence of myocardial infarction: 1. filling defects on the early scans, and 2. late enhancement of the myocardium on the delayed scans. The former were observed mainly at the sites of recent anterior myocardial infarction and the latter were seen in about half of the patients with recent and remote anterior myocardial infarctions. However, these findings were inadequately imaged in patients with inferoposterior infarction and subendocardial infarction. Among 137 patients with transmural infarction, enhanced CT revealed left ventricular aneurysms in 51 (37%) and ventricular thrombi in 26 (19%). ECG-gated MRI apparatus having a superconducting magnetic operating at 0.25 Tesla was used, and data for this study were collected using the single-slice spin echo technique. In eight of nine patients with acute myocardial infarction, gated MRI demonstrated the infarcted myocardium as regions of high signal intensity relative to that of the adjacent normal myocardium. Such a difference in MRI signal intensity was scarcely recognized in the chronic stage of myocardial infarction, but the indirect findings of infarction, such as regional wall thinning, wall motion disturbances, left ventricular aneurysms, and ventricular thrombi were easily detected using MRI. No characteristic finding was obtained by CT or MRI in patients with angina pectoris.

Aged↗

Secretion into the culture medium of a foreign gene product from Escherichia coli: use of the ompF gene for secretion of human beta-endorphin.

The ompF gene codes for a major outer membrane protein of Escherichia coli. A plasmid was constructed in which the structural gene for human beta-endorphin is preceded by the upstream region of the ompF gene consisting of the promoter region and the coding regions for the signal peptide and the N terminus of the OmpF protein. When the plasmid was introduced into E. coli N99, and OmpF-beta-endorphin fused peptide was synthesized and secreted into the culture medium through both the cytoplasmic and outer membranes. The OmpF signal peptide was cleaved correctly during the secretion, indicating that the export of the fused protein across the cytoplasmic membrane was dependent on the signal peptide. The secretion into the culture medium was apparently selective. Neither beta-lactamase nor alkaline phosphatase (both are periplasmic proteins) appeared in the culture medium in significant amounts. The mode of passage of the fused peptide across the outer membrane is discussed.

Bacterial Outer Membrane Proteins↗

Fucosylation of serum alpha-fetoprotein in patients with primary hepatocellular carcinoma.

alpha-Fetoprotein specimens were prepared from the sera of four patients with hepatocellular carcinoma. The lentil lectin-reactive and lectin-nonreactive variants of this glycoprotein were also prepared from the serum of one of the four patients by affinity chromatography with immobilized lectin. The correlation between the carbohydrate structure of these compounds and their reactivity in crossed immuno-affinoelectrophoresis with lentil lectin was studied by chemical analysis and affinity chromatography of the glycopeptides with lectin columns. It was found that the lentil lectin-reactive variant contained a carbohydrate chain of the fucosylated biantennary complex type. These data together with previous findings indicate that most of the patients with hepatocellular carcinoma have an elevated serum concentration of fucosylated alpha-fetoprotein.

Carbohydrates↗

Glycosaminoglycans of human colonic mucosa and colonic adenocarcinoma.

The mucosal scrapings of the normal human colons and the colonic adenocarcinoma tissues were digested with pronase, and the glycosaminoglycan fractions were prepared by fractionation with cetylpyridinium chloride after treatment with deoxyribonuclease. Chondroitin sulfate A/C, heparan sulfate, and hyaluronic acid were contained in the glycosaminoglycan fraction of the normal tissue, but dermatan sulfate was undetectable. In contrast, the glycosaminoglycan fractions derived from the tumors contained substantial amounts of dermatan sulfate together with the foregoing three glycosaminoglycans. The total content of glycosaminoglycans per wet tissue weight was elevated in the tumor tissues, which was consistent with histochemical findings.

Adenocarcinoma↗