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Ikunosuke Sakurabayashi

Publications and source records attributed to Ikunosuke Sakurabayashi.

25 records · Page 2Linked to original sources
PubMed2002

Epitope analysis of human immunoglobulin D with a mouse monoclonal anti-Fab delta chain antibody.

BACKGROUND: The clinical significance of IgD measurements in serum is limited as the frequency of abnormal concentrations is rare. METHODS: We prepared a mouse monoclonal antibody and a rabbit polyclonal antibody against Fab delta and Fc delta chain and compared epitope recognition by the monoclonal antibody against Fab delta (anti-Fab delta mono) with that by other antibodies. RESULTS: Anti-Fab delta mono specifically reacted with purified IgD and Fab delta of myelomatous origin, but not with other isotypes and light chains. In 19 of 22 myeloma sera, the monoclonal antibody recognized intact IgD and/or its fragments when analyzed by immunoblotting. Of these there were only four cases in which possible Fab delta fragments were identified. The other three sera showed no reactivity with the antibody and the IgD value was low on a chemiluminescence enzyme immunoassay. CONCLUSIONS: These findings indicate the presence of at least two immunochemically different IgD molecules in the sera. No positive reaction with any synthetic peptide was observed for the antibody on delta-chain ranging from N-terminus of JH, C delta 1 to a hinge region. We suggest that the epitope recognized by the antibody is related to the variable region or a conformational structure on the Fd delta region of IgD.

Amino Acid Sequence↗
PubMed2002

Mitogenic activity of oxidized lipoprotein (a) on human vascular smooth muscle cells.

Although oxidized lipoproteins may play an important role in the progression of atherosclerosis, no report has mentioned the significance of oxidized lipoprotein (a) (Lp[a]) in the pathogenesis of cardiovascular disease. Initially, we compared the mitogenic actions of Lp(a) and oxidized Lp(a) on human vascular smooth muscle cells (VSMC). Lp(a) significantly stimulated the growth of human VSMC in a dose-dependent manner, whereas oxidized Lp(a) showed a stronger stimulatory action on VSMC growth than native Lp(a). Interestingly, antioxidants probucol and fluvastatin inhibited the oxidation of Lp(a). Moreover, the stimulatory effect of oxidized Lp(a) on human VSMC growth was significantly inhibited by probucol. Finally, we elucidated the molecular mechanisms of how Lp(a) stimulated the growth of VSMC. Extracellular signal-regulated kinase (ERK), as those controlled by kinases, modulate critical cellular functions such as cell growth, differentiation, and apoptosis, was transiently phosphorylated by oxidized Lp(a) as well as native Lp(a) from 5 minutes, and the phosphorylation disappeared within 30 minutes. The degree of ERK phosphorylation by oxidized Lp(a) was much higher than that by native Lp(a). Administration of a specific inhibitor of MEK, PD 98059, significantly attenuated VSMC growth induced by native Lp(a) or oxidized Lp(a) in a dose-dependent manner (P<0.01). The current study demonstrated that oxidized Lp(a) is more potent than native Lp(a) in stimulating VSMC growth. Oxidized Lp(a) may play an important role in the pathogenesis of vascular disease.

Aorta↗
PubMed2002

Japanese familial hypercholesterolaemia with a 327insC mutation in the LDL receptor gene.

Mutations in the LDL receptor (LDLR) cause familial hypercholesterolaemia (FH) in an autosomal dominant manner. The condition frequently progresses to coronary atherosclerosis. We describe a patient with FH, but without ischaemic heart disease, who had a novel frameshift mutation (327insC) in exon 4 of the LDLR gene. This mutation introduced a premature termination codon (TGA, codon 158). The patient was a 59-year-old man who had presented with hypercholesterolaemia and a plasma total cholesterol (TC) concentration of 12.2 mmol/L at age 44 years. The mutation 327insC in this patient was heterozygous and hypercholesterolaemia was common within his family. Despite taking lipid-lowering medications (probucol and pravastatin) for more than 20 years, his TC concentration hardly fell below 7.8 mmol/L. However, neither the patient nor anyone else in his family developed characteristic symptoms of ischaemic heart disease or xanthoma. This patient was discovered by an intensive mutation survey among 22 unrelated Japanese with FH mainly in the Kanto area of Japan, suggesting a low incidence of the mutation in the area.

Electrophoresis, Polyacrylamide Gel↗
PubMed2002

[A go-between the laboratory medicine and clinical chemistry].

The Joint Annual Meeting of the Japanese Society of Laboratory Medicine and the Japanese Society of Clinical Chemistry is held in Yokohama at the first time in the history of both Societies. A chance of this time, we should consider the subjects to cooperate each Society. At first, standardization of the clinical tests at clinical laboratory field including clinical chemistry should be promoted by the both Societies. At second, EBLM(evidence based laboratory medicine) making the core of EBM (evidence based medicine) is very important tool practicing science based medicine by the reason of the getting out from experience-medicine. The hard effort which find out evidence on the clinical laboratory tests from enormous literature must be carried out on many clinical test items. In the Japanese Society of Laboratory Medicine, EBLM Committee was formed at last year and the work has been started. At third, if serum and other body fluids as well as tissues which are got from patients are used outside the purpose, ethics should be asked. Ethics Committee in both Society will make a guideline for the ethics for the handling the materials from patients including genetic subjects. At forth, clinical laboratory is said to be necessary the method of quality management(QM). The accreditation process is needed under unified national control survey, if we promote QM. At fifth, medical science rapidly advances at twenty-first century. Especially, there will be advanced at the fields of gene therapy, organ substitution, prevention and complete therapy of arteriosclerosis diseases and diabetes mellitus, terminal care, infectious diseases control and so on. The effective way of activating clinical laboratory is to related to those medical fields.

Chemistry, Clinical↗