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Biomedical subjects

K Imai

Publications and source records attributed to K Imai.

At least 1,477 records · Page 82Linked to original sources
PubMed1981

Molecular profiles of human melanoma-associated antigens.

Melanoma-associated antigens (MAA) shed into spent culture medium of intrinsically radiolabeled melanoma cells react specifically with monoclonal and polyclonal anti-melanoma xenoantiserums and are represented by two glycoproteins with molecular weights of 240,000 (240K) and 94,000 (94K): 240K is present only on melanoma cells whereas 94k is also found on carcinoma cells and on fetal melanocytes. Both 240K and 94K have been obtained radiochemically pure by utilizing cellulose ion-exchange and antibody affinity chromatography. The two antigens have different charge properties, as 240K binds to CM-cellulose while 94K does not. A difference in carbohydrate moieties is also indicated since 240K binds selectively to lentil lectin and 94K to ricin lectin. Two-dimensional gel electrophoresis an tryptic peptide maps of the two antigens reveal distinct and characteristics profiles. Subunit structure determination of both antigens suggests 94K to be a single chain whereas 240K appears to be a subunit of a larger molecular structure.

Antibodies, Neoplasm↗
PubMed1981

Hb Toyoake: beta 142 (H20) Ala replaced by Pro. A new unstable hemoglobin with high oxygen affinity.

A new unstable hemoglobin with high oxygen affinity, Hb Toyoake: beta 142 (H20) Ala replaced by Pro, was found in Japanese male with a normal blood hemoglobin level, shortened red cell survival, and increased plasma erythropoietin. Hemoglobin studies showed heat and isopropanol instability, and an increased tendency to heme loss and to subunit dissociation. Electrophoresis of whole hemolysate showed inconstant abnormal bands with reduced mobilities due to progressive heme loss during the in vitro procedure. Isolated Hb Toyoake with normal heme content migrated slightly faster than HbA. Oxygen affinity of red cells was elevated with P50 of 17.0 mm Hg at pH 7.4 and 37 degrees C (normal 25.0 mm Hg). Studies on hemolysate implied that Hb Toyoake had an almost normal Bohr effect, a diminished cooperativity, and a reduced response to inositol hexaphosphate. These multiple abnormalities are associated with a substitution of Pro for beta 142 Ala, resulting in disruption of the H-helix and the adjacent C-terminal portion of beta chain, which contain residues crucial for normal oxygen binding.

Adult↗
PubMed1980

Rapid determination of glycine- and taurine-conjugated bile acids in human bile by high-performance liquid chromatography.

With use of an anion-exchange packing, TSK Gel IEX 540 DEAE, for high-performance liquid column chromatography, glycine- and taurine-conjugated bile acids were separated in 10 min and detected with a differential refractometer. Human bile could be analyzed after a simple pretreatment. The purity of the peaks of glycine- and taurine-conjugated bile acids in human bile was confirmed by enzymatic determinations using 3 alpha-hydroxysteroid:NAD oxidoreductase. The molar ratios of the two forms of the conjugates (glycine/taurine ratios) in bile from normal subjects and from patients suffering from various hepatobiliary diseases were measured.

Bile↗
PubMed1980

A new method for experimental study on gastric mucosal damage--changes in gastric mucosa of rat in hypoxemia.

We have demonstrated development of mucosal damage in rats maintained in a hypoxic condition. The gastric lesions were observed only in the corpus ventriculi in almost all cases, and they were rated as Ul-1 erosions histopathologically. The method has proven to facilitate the induction of long-sustained, stable hypoxemia of any desired degree in animals and is concluded to be appropriate for an experimental model of ulceration designed for the study of defensive mechanisms.

Animals↗
PubMed1980

Macrophage activation by muramyl dipeptide as measured by macrophage spreading and attachment.

A synthetic bacterial cell wall constituent, muramyl dipeptide (MDP), was found to induce the enhancement of macrophge spreading and attachment on glass or plastic surfaces. Macrophages exposed to bacterial lipopolysaccharide or lymphokine-containing cell supernatants showed similar enhancement. This finding supports the view that MDP activates macrophages. MDP was also found to enhance the viability of macrophages but to inhibit 3H-thymidine incorporation by macrophages.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1980

Functional studies of abnormal hemoglobins in Japan.

Oxygen binding properties of fifteen kinds of abnormal hemoglobins discovered in Japan were elucidated with the automatic oxygenation apparatus which was developed by Imai et al. This paper reviews the functional characteristics of those hemoglobins previously reported, presents functional data of some newly studied hemoglobins, and gives a discussion on structure-function relationships in those hemoglobins. This paper also describes a simple procedure for generating a predicted oxygen equilibrium curve of non-isolatable hemoglobin from equilibrium curves of normal hemolysate and hemolysate containing that hemoglobin.

Hemoglobins, Abnormal↗