Masaaki Kojima

Are you Masaaki Kojima?

Claim your profile

Publications (3)4.38 Total impact

  • Source
    Article: Determination of immuno-reactive rabbit apolipoprotein B-48 in serum by ELISA.
    Makoto Kinoshita, Teruhiko Matsushima, Yamato Mashimo, Masaaki Kojima, Megumi Kigure, Tamio Teramoto
    [show abstract] [hide abstract]
    ABSTRACT: Apolipoprotein B-48 (apoB-48) is produced by the small intestine, is associated with chylomicrons, and appears to be a suitable marker for clinical studies of postprandial dynamics of lipoproteins. It is also associated with cardiovascular risk factors. We have developed an assay system to quantify immuno-reactive apoB-48 in rabbit serum or plasma. A microtiter-plate was coated with monoclonal antibody raised against human apoB-48 C-terminal specific decapeptide that has high homology to the rabbit C-terminal sequence. Appropriate ELISA standard curves were obtained using apoB-48 extracted from rabbit serum by immuno-affinity chromatography. No cross-reactivity was found with apoB-100 in western blot analyses. Intra- and inter-assay CVs were less than 3%. Recovery of rabbit apoB-48 spiked in serum was within 93.4-105%. ApoB-48 levels in healthy controls rabbits fed a normal diet were within the range of 0.903-1.09 microg/ml (mean +/- SD: 1.03 +/- 0.084 microg/ml). In healthy animals, the blood apoB-48 level was markedly increased by a high fat diet and in the postprandial state in parallel with serum triglyceride. Ezetimibe, cholesterol absorption inhibitor, given orally to rabbits fed on a high fat diet blocked further increase of blood levels of apoB-48 and triglyceride. This method for measuring apoB-48 using the monoclonal antibody is simple, reliable, and suitable for routine analyses.
    Experimental Animals 01/2010; 59(4):459-67. · 0.92 Impact Factor
  • Article: Correlation between body weight (epididymal fat) and permeation rate of serum leptin through the blood-brain barrier (BBB) in male rats aged 8 months.
    Mitsuro Suzuki, Qing Ding, Shiro Muranaka, Megumi Kigure, Masaaki Kojima, Misao Terada, Noyuri Kataoka, Akiko Hagiwara, Pudcharaporn Kromkhun, Naoki Moritani, Haruo Hashimoto, Makoto Yokosuka, Fujiro Sakurai, Minoru Tanaka, Toru R Saito
    [show abstract] [hide abstract]
    ABSTRACT: In this study, in order to clarify the kinetics of leptin, we focused on the ratio of leptin concentrations in cerebrospinal fluid and serum in aged male rats, and examined the weight of epididymal fat, and the passage rate of leptin through the blood-brain barrier. In the lighter animals, the epididymal fat weight was low, while leptin concentrations in the serum and cerebrospinal fluid were also low. Conversely, in the heavier animals, the weight of epididymal fat and leptin concentrations in the serum and cerebrospinal fluid were higher. With regard to the ratio of leptin in the cerebrospinal fluid and serum, the passage rate of leptin through the blood-brain barrier was lower in the heavier animals than in the lighter animals.
    Experimental Animals 11/2008; 57(5):485-8. · 0.92 Impact Factor
  • Article: Determination of apolipoprotein B-48 in serum by a sandwich ELISA.
    Makoto Kinoshita, Masaaki Kojima, Teruhiko Matsushima, Tamio Teramoto
    [show abstract] [hide abstract]
    ABSTRACT: Apolipoprotein B-48 (apoB-48) is produced by the small intestine, as a part of chylomicrons (CMs), and appears to be a suitable marker for clinical studies of postprandial lipoproteins and related cardiovascular risk factors. We have developed an assay for routine analysis to quantify apoB-48 in serum or plasma. A microtiter plate was coated with monoclonal antibody (4C8) raised against apoB-48 C-terminal specific decapeptide. Serum samples were diluted 100-fold with 0.05 mol/l Tris-HCl buffer (with or without 0.1% Triton X-100). Appropriate calibration curves were obtained in the ELISA by using apoB-48 recombinant antigen. No cross-reactivity (<0.001%) was found with apoB-100, as verified by ELISA and Western blot analyses. Intra- and inter-assay CVs were 4.8% and 5.4%, respectively. Recovery of added recombinant apoB-48 in serum was within 94-105%. The assay linearity was intact >5-fold dilution of serum by dilution buffer. ApoB-48 levels in healthy controls (n=18) at fasting were within the range of 2.69-6.56 microg/ml (mean+/-S.D.: 4.60+/-1.54 microg/ml). In healthy subjects, serum apoB-48 concentrations markedly increased in the postprandial state, in parallel with serum triglycerides. This method for measuring apoB-48 using the monoclonal antibody 4C8 is simple, reliable and suitable for routine analyses.
    Clinica Chimica Acta 01/2005; 351(1-2):115-20. · 2.54 Impact Factor
Browse more researchers