Mitsutoshi Sugano

Bio: Mitsutoshi Sugano is an academic researcher from Shinshu University. The author has contributed to research in topics: Lipoprotein & Apolipoprotein E. The author has an hindex of 14, co-authored 70 publications receiving 726 citations.

Analysis of human serum lipoprotein lipid composition using MALDI-TOF mass spectrometry.

Abstract: This study used matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify all lipid classes in human serum lipoproteins. After the major lipoproteins classes were isolated from serum by ultracentrifugation, the lipids were extracted and mixed with 2,5-dihydroxybenzoic acid (2,5-DHB) dissolved in Folch's solution (chloroform/methanol 2:1, v/v). MALDI-TOF MS analysis of the samples identified phospholipids (PLs), lysophospholipids (lysoPLs), sphingolipids (SLs), triglycerides (TGs), cholesteryl esters (CEs), and free cholesterol; it also showed the characteristics of individual fatty acid chains in serum lipids. MALDI-TOF MS allowed analysis of strongly hydrophobic and non-polar molecules such as CEs and TGs as well as hydrophilic molecules such as phospholipids. Direct analysis of fatty acids was not possible. The concentrations of lipids were not consistent with the ion peak intensities, since the extent of polarity affected the ionization characteristics of the molecules. However, lipid molecules with similar molecular structures but various fatty acid chains, such as phosphatidylcholine (PCs), were analyzed quantitatively by MALDI-TOF MS. Quantitative measurement of cholesterol was possible with the use of an internal standard. This study shows that MALDI-TOF MS can be used for direct investigation and quantitative analysis of the phospholipid composition of serum lipoproteins.

Apolipoprotein E in Cerebrospinal Fluid: Relation to Phenotype and Plasma Apolipoprotein E Concentrations

Abstract: Background: Apolipoprotein (apo) E may be related to the development of Alzheimer disease, but data on apoE in cerebrospinal fluid (CSF) are limited. The aim of the present study was to measure apoE in CSF and relate its concentrations to apoE phenotype and CSF lipids. Methods: We adapted an assay for CSF apoE sensitivity using an ELISA. It allowed us to measure CSF apoE with sufficient reproducibility and precision. Results: The within- and between-run CVs were 5 year group (n = 34; 8.82 ± 3.31 mg/L). The mean concentrations of total cholesterol (TC) and phospholipid (PL) in CSF were 2.68 ± 2.16 and 6.50 ± 2.84 mg/L (n = 52), respectively. Although no significant differences in TC or PL in the CSF were found with respect to sex or age, the concentrations in subjects with the apoE phenotype E4/E3 were significantly lower than in those with E3/E3 and E3/E2. The concentrations of apoE, TC, and PL in CSF did not correlate with those in plasma. The time-related fluctuations in CSF apoE were independent of those in total protein and IgG. CSF apoE was significantly correlated with TC and PL concentrations in the CSF, but not with the number of cells in the CSF. Conclusions: These findings support the idea that apoE and lipids are unable to cross the blood-brain barrier and that their concentrations in CSF may reflect production in central nervous tissue.

Higher avidity binding of apolipoprotein (E-AII) complex than of apolipoprotein E monomer to beta-amyloid.

Abstract: Apolipoprotein E (apoE) is believed to be closely involved in the pathogenesis of Alzheimer's disease (AD) because of its ability to bind to β-amyloid (Aβ), the primary component of senile plaques. The presence of cystein residues in apoE2 and apoE3 allows these isoforms to form disulfide-linked complexes, such as apo(E–AII) complex and apo(AII–E–AII) complex. A 50-kDa complex [which corresponded to apo(E–AII)–Aβ, because it reacted with any of the three antibodies, anti-apoE, anti-apoAII, or anti-Aβ] was detected by immunoblot analysis in native cerebrospinal fluid (CSF) obtained from nondementia patients with the apoE phenotype E3/E3. However, a band considered to represent apoE–Aβ was not observed. The dissociation constant (Kd) values obtained for the specific binding of recombinant apoE2, apoE3, and apoE4 to Aβ1–42 were 48.1 ± 2.2 nM, 63.7 ± 2.1 nM, and 75.9 ± 1.8 nM, respectively. In contrast, the binding affinity of the partially purified apo(E3–AII) complex to Aβ1–42 was very high, the Kd being 5.5 ± 0.5 nM. No basic difference was observed between lipidated and nonlipidated apoE in terms of the characteristics of the binding of apoE isoforms to Aβ1–42; however, lipidation reduced the binding capacity of each isoform in a dose-dependent manner. These findings seem consistent with the generally accepted idea that apoE4 is a risk factor for AD, insofar as only apoE4 is unable to form a complex with apoAII owing to its lack of a cystein residue. In addition, it is possible that apoE3 monomer (and possibly apoE2 monomer), like apoE4 but unlike apo(E–AII) complex, can act as a risk factor in the pathogenesis of AD. J. Neurosci. Res. 58:301–307, 1999. © 1999 Wiley-Liss, Inc.

Management of Helicobacter pylori infection—the Maastricht V/Florence Consensus Report

Abstract: Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

Management of Helicobacter pylori infection—the Maastricht IV/ Florence Consensus Report

Abstract: Management of Helicobacter pylori infection is evolving and in this 4th edition of the Maastricht consensus report aspects related to the clinical role of H pylori were looked at again in 2010. In the 4th Maastricht/Florence Consensus Conference 44 experts from 24 countries took active part and examined key clinical aspects in three subdivided workshops: (1) Indications and contraindications for diagnosis and treatment, focusing on dyspepsia, non-steroidal anti-inflammatory drugs or aspirin use, gastro-oesophageal reflux disease and extraintestinal manifestations of the infection. (2) Diagnostic tests and treatment of infection. (3) Prevention of gastric cancer and other complications. The results of the individual workshops were submitted to a final consensus voting to all participants. Recommendations are provided on the basis of the best current evidence and plausibility to guide doctors involved in the management of this infection associated with various clinical conditions.

Small Colony Variants: a Pathogenic Form of Bacteria that Facilitates Persistent and Recurrent Infections

Abstract: Small colony variants constitute a slow-growing subpopulation of bacteria with distinctive phenotypic and pathogenic traits. Phenotypically, small colony variants have a slow growth rate, atypical colony morphology and unusual biochemical characteristics, making them a challenge for clinical microbiologists to identify. Clinically, small colony variants are better able to persist in mammalian cells and are less susceptible to antibiotics than their wild-type counterparts, and can cause latent or recurrent infections on emergence from the protective environment of the host cell. This review covered the phenotypic, genetic and clinical picture associated with small colony variants, with an emphasis on staphylococci, for which the greatest amount of information is available.