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Biomedical subjects

N Kitazawa

Publications and source records attributed to N Kitazawa.

12 recordsLinked to original sources

Expression of cell division cycle 2 kinase transcription in chronically rejected cardiac allografts of nonhuman primates.

Accurate diagnosis and prevention of graft arteriosclerosis, known as chronic rejection, is critical to the success of cardiac transplantation, but often is difficult to attain. Expression of cell division cycle (cdc) 2 kinase, which plays a critical role in cell transition through the G2/M phase, is critical to the proliferation of vascular smooth muscle cells. To evaluate the usefulness of cdc2 kinase expression for pathophysiological analysis of chronic rejection, heterotopic cardiac transplantation was performed in Japanese monkeys (n = 7). Standard reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ RT-PCR were performed to evaluate the expression. In the coronary arteries of chronically rejected allografts, enhanced cdc2 kinase expression was observed in thickened intima and media, while none was expressed in native hearts. The cdc2 kinase was also expressed before the intimal thickening occurred. These results indicate that enhanced expression of cdc2 kinase is a sensitive indicator for chronic cardiac rejection; targeting cdc2 kinase may be a viable gene therapy for prevention of this vasculopathy.

Animals↗

Determination of hemoglobin A1C in normal and diabetic mice: neonatal streptozotocin-induced diabetic mice and KK-Ay mice.

We have determined Hemoglobin A1C (HbA1C) in normal, neonatal streptozotocin-induced diabetic animals (NSZ), a model of lean-type non-insulin-dependent diabetes mellitus (NIDDM) with hypoinsulinaemia, and KK-Ay mice, a model of obese-type NIDDM with hyperinsulinaemia. The HbA1C of NSZ mice was slightly increased from 5 to 20 weeks while the HbA1C of KK-Ay mice was markedly increased from 5 to 10 weeks. Our findings showed a difference between experimentally-induced (NSZ) and genetically (KK-Ay) diabetic animals.

Animals↗

An adult case of adrenoleukodystrophy with features of olivo-ponto-cerebellar atrophy: II. Lipid biochemical studies.

Different portions with or without demyelination or degeneration of formalin-fixed brain tissues of a patient with adrenoleukodystrophy and a control subject were applied to analyses of lipids, particularly sphingolipids and cholesteryl ester. Demyelinated area of the white matter in the occipital lobe showed marked decrease in cerebroside and sulfatide except for sphingomyelin and, conversely an accumulation of cholesteryl ester, whereas un-demyelinated white matter in the frontal lobe showed no abnormalities in lipids. Abnormalities of lipids in degenerated lateral nuclei of the thalamus were not so remarkable as the demyelinated white matter, whereas apparently normal dorsomedial nuclei of the thalamus showed no abnormalities in lipids. With regard to the fatty acid composition of abnormal lipids in the demyelinated white matter, all sphingolipids of cerebroside, sulfatide, and sphingomyelin showed remarkable reduction of their longer chain fatty acids and, conversely a significant increment of shorter chain fatty acids. However, these fatty acids in the degenerated lateral nuclei of the thalamus were not so different from those in the undemyelinated and apparently normal areas as well as in control brain. The fatty acids of cholesteryl ester contained mainly C18:1 and C16 acids, and very long chain fatty acids, namely fatty acids with chain length more than 22 carbons, by about 22% of the total fatty acids. In view of the analytical results of the fatty acid composition of brain lipids, it was inconceivable that this ALD patient brain showed especially the accumulation of very long chain fatty acids, and that the biochemical defect in this disease was related to the abnormal oxidation of very long chain fatty acids in peroxisomes. However, the neuropathological findings of demyelination, reactive astrocytosis, and massive infiltration of foam cells well correlated with the abnormalities in myelin lipids and the accumulation of cholesteryl ester. Also, the lower values of urinary 17-ketosteroid and 17-hydroxycorticosteroid suggested that the failure of ACTH to stimulate corticoid secretion seemed to indicate the relationship between the adrenocortical insufficiency and the affected areas of the central nervous system.

Adrenoleukodystrophy↗

Antibody response of rabbits to nerve ending gangliosides. Analysis of antibody specificity by liposome lysis and lysis inhibition assays.

Rabbits were immunized with nerve ending fraction prepared from guinea pig brain. Serum antibodies to total gangliosides were followed by enzyme-linked immunosorbent assay; their titers were highest at 2 to 3 weeks after immunization and some rabbits showed a response to reinjections. Specific reactivities of the antibodies against each molecular species of gangliosides were analyzed by liposome lysis assay and liposome lysis inhibition assay. Antibody responses were detected against GM1, GD1b, GM3 and GM2, but not against GD1a and GT1b. Natural and immune antibodies to the asialo glycolipids and to galactosylceramide were also observed.

Animals↗

Abnormalities of glycosphingolipids in mucopolysaccharidosis type III B.

Glycosphingolipids from brain, liver, and spleen of a patient with mucopolysaccharidosis type III B were quantitatively analyzed. Neutral glycosphingolipids containing glucosylceramide, lactosylceramide, globotriaosylceramide, globotetraosylceramide, and gangliotriaosylceramide were increased in the brain, while the contents of galactosylceramide and galactosylceramide I3-sulfate were decreased. The total ganglioside levels were low in the grey matter (522 micrograms N-acetylneuraminic acid/g) and high in the white matter (342 micrograms N-acetylneuraminic acid/g), when compared with the normal values (744-918 micrograms/g in grey matter and 80-180 micrograms/g in white matter). The ganglioside compositions were characterized by a high proportion of II3-N-acetylneuraminosylgangliotriaosylceramide (GM2), II3-N-acetylneuraminosyllactosylceramide (GM3), and II3-(N-acetylneuraminosyl)2lactosylceramide (GD3). An unusual band of protein in place of an ordinary band of Wolfgram protein was detected as a major band by sodium dodecylsulfate-polyacrylamide gel electrophoresis. The low levels of 4-eicosasphingenine in the brain gangliosides indicated that the disturbance of the sphingolipid metabolism already began at age 3 at the latest and that the brain remained immature. These abnormal glycosphingolipids and protein as well as the accumulation of heparan sulfate explain in part the severe progressive mental retardation which is most characteristic of the mucopolysaccharidosis III B. Abnormalities of glycosphingolipids in the liver and spleen are also found.

Acetylglucosaminidase↗

Immunochemical determination of Forssman and blood group A-active glycolipids in human gastric mucosa by inhibition assay of liposome lysis.

A simple liposome immunoassay, liposome immune-lysis inhibition (LILI) assay, is described for quantitative determination of individual glycolipid antigens. Liposomes containing fluorogenic marker, 4-methylumbelliferyl phosphate, were prepared from sphingomyelin, cholesterol, dicetylphosphate and standard glycolipid. Release of trapped markers from these liposomes by antibody and complement (liposome lysis) was inhibited by preincubating the antibody with test glycolipid incorporated into inhibitor liposomes. Based on the competitive inhibition, it was possible to quantitate each glycolipid antigen in less than picomolar amounts. The sensitivity and specificity of the assay were examined with purified glycolipid standards. LILI assay has been applied for the determination of Forssman glycolipid and blood group A-active glycolipid in human gastric mucosa and cancer tissues.

ABO Blood-Group System↗

Liposome agglutination and liposomal membrane immune-damage assays for the characterization of antibodies to glycosphingolipids.

Antibodies against each of three neutral glycosphingolipids, Forssman glycolipid, globoside I, and asialo GM2, were elicited in rabbits. The specificity of these antibodies was studied by liposome agglutination and liposomal membrane immune-damage assays using liposomes prepared with each glycolipid hapten. Spectrophotometric measurement of liposome agglutination was found to be effective for detecting IgG antibodies, whereas complement-dependent immune-damage assay favored the expression of IgM antibodies. Three glycosphingolipids having the same non-reducing terminal N-acetylgalactosamine residues were discriminated with IgG antibodies, while IgM antibodies showed cross-reactivity. Specifically purified anti-Forssman and anti-asialo GM2 antibodies reacted only with Forssman glycolipid and asialo Gm2, respectively, but purified anti-globoside I antibodies cross-reacted with asialo GM2.

Agglutination↗

Immunochemical studies of lipids. IV. Reactions of anti-sulfatide antibodies with sulfatide in liposomal and myelin membranes.

Antibodies against sulfatide (3-sulfogalactopyranosylceramide) were raised in rabbits by an intradermal injection of a mixture of sulfatide and bovine serum albumin in Freund's complete adjuvant followed by three to five booster injections in complete adjuvant. Complement fixation assays done with liposomes containing lecithin-cholesterol-hapten (1 : 0.75:0.1, by mol) demonstrated the reactivity of the antibodies with sulfatide, but not with galactosylceramide. The antibody activity was found entirely in the IgM fraction after Sephadex G-200 gel filtration. Anti-sulfatide antibodies were purified with liposomes as the immunoadsorbent. Sulfatide in artificial and natural membranes could react with these antibodies to cause complement-dependent release of a fluorogenic marker from liposomes and resealed myelin membrane vesicles.

Animals↗