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Biomedical subjects

H J Yang

Publications and source records attributed to H J Yang.

At least 73 records · Page 4Linked to original sources
PubMed1991

Metacercarial infections of Paragonimus westermani in freshwater crabs sold in markets in Seoul.

Status of metacercarial infections of Paragonimus westermani was observed in freshwater crabs, which were purchased at 3 markets in its peak season of 1990. All of 85 crabs were Eriocheir japonicus. No other species of Eriocheir were found. When crushed muscle and viscera was examined individually, the infection rate was 11.8%; and mean number of metacercariae was 2.1 per infected crab. Unless adequately cooked, freshwater crabs are still potential sources of human paragonimiasis.

Animals↗
PubMed1991

Changes of IgM and IgG antibody levels in experimental rabbit anisakiasis as observed by ELISA and SDS-PAGE/immunoblot.

Antibody changes in experimental anisakiasis were observed in 10 rabbits which were infected each with 10 Anisakis simplex larvae. The sera were collected before and on the 6th to the 95th day after the infection. Using crude saline extract of Anisakis larvae as antigen, specific IgM and IgG antibody levels were observed by ELISA and SDS-polyacrylamide gel electrophoresis/immunoblot. Levels of specific-IgM antibody were elevated from the 6th day, reached their peaks on the 11th day after the infection, and dropped thereafter. Serum levels of IgG antibody increased from the 6th day and reached their peak on the 26th day after the infection, and decreased gradually thereafter. When SDS-PAGE of the crude extract was done, at least forty-one SDS-polypeptide bands were recognized. Of them, IgM antibody reacted mainly to the bands of 168, 95, 74, 64, 51, 47 and 34 kDa while IgG antibody reacted strongly to 168, 92, 85, 64, 58, 52, 42 and 40 kDa bands. The crude extract showed negligible cross reactions with sera of other parasitic diseases and normal control.

Animals↗
PubMed1991

Diagnosis of gastric polypoid lesions by magnifying endoscopy and dye endoscopy.

From July 1989 to June 1990, a total of 19 patients with gastric polyps were studied by magnifying endoscopy and dye endoscopy. After pretreatment with pronase, both close and magnified pictures were observed before and after sprays of 0.2% indigo carmine. Polypectomy or multiple biopsies were done after endoscopic examinations. Of the 19 patients; 13 were classified as hyperplastic polyps and 6 as neoplastic polyps by histologic examination. Twelve of the 13 hyperplastic polyps showed regular sulciolar or sulciolar-mesh mucosal patterns after magnification, only 1 showed an irregular sulciolar-mesh pattern. All 6 neoplastic polyps showed irregular or destructive mucosal patterns. Hyperplastic polyps have a significantly higher rate of regular, fine gastric mucosal patterns. Contrast staining with indigo carmine did not significantly improve the observations. We conclude that magnifying endoscopy is useful in the diagnosis of gastric polyps; polyps with fine, regular gastric pits indicate a diagnosis of hyperplastic polyps, while irregular or destructive mucosal patterns suggest a high possibility of neoplastic polyps.

Coloring Agents↗
PubMed1990

Polymer-protein conjugates. I. Effect of protein conjugation on the cloud point of poly (N-isopropylacrylamide).

Poly (N-isopropylacrylamide) (p(NIPAAm] exhibits a cloud point around 32 degrees C. In this study we have conjugated several proteins to p(NIPAAm), and the effects of protein molecular weight, pH and ionic strength on the cloud point of the p(NIPAAm)-protein conjugates have been studied. The cloud points of p(NIPAAm)-protein conjugates appear to be unaffected by the molecular weight or isoelectric point (pl) of the proteins, the pH or ionic strength.

Acrylic Resins↗
PubMed1989

Value of angina pectoris after myocardial infarction in predicting extent of coronary artery disease.

Clinical, hemodynamic, and angiographic data were examined in 53 patients who underwent catheterization within 6 months of documented acute transmural myocardial infarction (MI). The patients were divided into two groups on the basis of presence (23 patients, group I) or absence (30 patients, group II) of angina pectoris 1 month after MI. Group I patients had more severe coronary artery disease and a greater prevalence of multivessel disease than group II patients. Partial preservation of segmental left ventricular wall function in group I was related to the presence of collateral vessels. In patients with single vessel disease, incidence of spontaneous recanalization of the infarct-related artery was more common in group I as compared with those in group II. It is concluded that angina pectoris after MI suggests multivessel disease or infarct-related artery recanalization. Coronary angiography may be advised in these patients in order to select adequate therapeutic interventions and improve prognosis.

Aged↗
PubMed1989

[Studies on the metabolism of antiepilepserine in isolated perfused rat liver].

The metabolism of antiepilepserine, 3,4-methylene dioxycinnamyl piperidine, was studied in isolated perfused rat liver. Two metabolites were separated and purified by means of HPLC. They were identified as 3,4-methylene dioxycinnamyl hydroxypiperidine and 4-hydroxy-3-methoxycinnamyl piperidine by UV and MS. The latter was further confirmed by chemical synthesis. The pharmacokinetics of antiepilepserine in isolated perfused liver was also studied. Parameters obtained include a first order elimination constant, k = 0.0157 +/- 0.0043 min-1, and a half-life, t 1/2 = 46.7 +/- 11.9 min, (n = 6). The amount of antiepilepserine lost during the perfusion could not be compensated by the increased amount of metabolites. Antiepilepserine was found to be tightly bound and stored in the liver. This might be one of the explanations of the first pass effect of antiepilepserine after oral administration.

Animals↗
PubMed1987

Mitogenic effect of polyclonal anti-porcine lymphocyte E-receptor antiserum IgG.

In the present paper we report the mitogenic effect of the sheep anti-porcine lymphocyte E-receptor antiserum IgG(APERIgG) on porcine peripheral T-lymphocytes in vitro. The effect was apparently dose-dependent and not seen in the B-lymphocyte cultures. Kinetic study showed that the maximal 3H-thymidine incorporation, similar to that induced by Con A, occurred on the third day of incubation. Neither F(ab')2 nor Fab fragment of APERIgG was able to induce cell proliferation, indicating that the integrity of IgG molecule was essential for cell response. It was very interesting to note that though there is cross antigenicity between porcine and human E-receptors, no similar effect could be produced by APERIgG in human peripheral lymphocyte cultures under the same experimental conditions, suggesting the existence of minor difference in structure between the porcine and human E-receptors.

Animals↗
PubMed1985

Endothelial wound-healing in penetrating corneal graft for experimental bullous keratopathy in rabbit.

Persistent bullous keratopathy was produced in one eye of a rabbit by anterior chamber irrigation with benzalkonium chloride solution (BAK). Corneal grafts were made from both eyes of another rabbit and they were transplanted to the eye with bullous keratopathy and the normal fellow eye, which served as the control. Subsequently, at intervals flat preparations of the endothelium of both eyes stained with silver nitrate were made. On panoramic photographs of the endothelium along one meridian of the cornea, the endothelial cell sizes were determined on both sides of the host-graft junction and at every 1 mm from the junction. In the control eyes the cell sizes increased, in the early postoperative period, near the host-graft junction both in the graft and in the host, and this increase gradually diminished by the end of the 6-month observation period. However, even after 6 months the mean cell size in both graft and host was slightly larger than the normal cell size. In the eye with bullous keratopathy, the cell size in the graft center increased rapidly and progressively. After 3 months the endothelial cells were seen in the host cornea and the cell sizes were considerably larger than those in the control cornea. After 6 months the cells were seen even in the periphery of the host cornea. In three sets of experiments, bullous keratopathy was produced in one eye of a male rabbit and the graft from a female rabbit was transplanted. Four months later, the detection frequency of the sex chromatin stained with acetic orcein was similar between the cells in the graft and in the host bullous cornea, indicating that the cells in the host had migrated from the graft.

Animals↗
PubMed1978

Effect of periodate oxidation on specific activities and carbohydrate components of human blood group N- and M-specific glycoproteins and glycopeptides.

Mild as well as strong periodate oxidation of isolated erythrocyte N and M glycoproteins and glycopeptides gave extensive to complete destruction of N-specificities as measured with Vicia graminea extracts and of N- as well as M- activities determined with all but 1 of 8 animal anti-N and 13 anti-M sera. Results with human antisera differed somewhat, while the specificity of mildly oxidized N-glycoprotein was completely destroyed as determined with all 8 human anti-N sera used, that of strongly oxidized N-active substance was completely inactivated towards one of the human antisera; the remainder showed 63--94% destruction, and 2 sera indicated no effect of oxidation. Similarly, while 10 of 14 human anti-M indicated complete inactivation of M-specific glycoproteins and glycopeptides after mild or strong oxidation, 2 showed partial inactivation and 2 human anti-M sera showed no inactivating effect of oxidation. The most relevant findings of quantitative carbohydrate analysis of periodate oxidized N- and M-specific substance were extensive transformation of N-acetylneuraminic acid (NAN) to its C8 and C1 analogues on mild oxidation and pronounced destruction of NAN and its analogues on strong oxidation; however, some intact NAN always remained. In all instances galactose (Gal) was destroyed to a much larger extent in N-derived than in M-derived glycoproteins and glycopeptides.

Amino Acids↗
PubMed1975

Crystallographic studies on L-asparaginase from Proteus vulgaris. II. Symmetry and location of the tetrameric molecule.

Analyses of the x-ray diffraction intensity data by the Patterson synthesis and rotation function techniques show that the true space group of the monoclinic crystals of L-asparaginase (L-asparagine amidohydrolase, EC 3.5.1.1) from Proteus vulgaris is P21, that the molecular centers lie at x = 0.054, y = 0, z = 0.256, and its symmetry related positions, and that the tetramer molecules possess three approximate, mutually perpendicular 2-fold rotational symmetries, the axes of which run along the directions of the crystallographic a*-, b-, and c-axes. In addition, an investigation of the molecular packing arrangement in the crystal indicates that the tetramer molecules possess an approximately regular tetrahedral subunit structure.

Asparaginase↗