Molecular genetic epidemiology of homozygous familial hypercholesterolemia in the Hokuriku district of Japan

金沢大学医学系研究科Aim: Familial hypercholesterolemia (FH) is caused by mutations of FH genes, i.e. LDL-receptor (LDLR), PCSK9 and apolipoprotein B (ApoB) gene. We evaluated the usefulness of DNA analysis for the diagnosis of homozygous FH (homo-FH), and studied the frequency of FH in the Hokuriku district of Japan. Methods: Twenty-five homo-FH patients were recruited. LDLR mutations were identified using the Invader assay method. Mutations in PCSK9 were detected by PCR-SSCP followed by direct sequence analysis. Results: We confirmed 15 true homozygotes and 10 compound heterozygotes for LDLR mutations. Three types of double heterozygotes for LDLR and PCSK9 were found. No FH patients due to ApoB mutations were found. The incidences of homo-FH and hetero-FH in the Hokuriku district were 1/171,167 and 1/208, respectively. Conclusions: Our observations underlined the value of FH gene analysis in diagnosing homo-FH and confirmed extraordinarily high frequency of FH in the Hokuriku district of Japan. © 2010 Elsevier Ireland Ltd

Preferential Enzymatic Hydrolysis of Phosphatidylcholine in Skipjack Flesh during Frozen Storage

Enzymatic hydrolysis of phosphatidylcholin (PC) in skipjack flesh during storage at -20°C for 16 weeks was studied by following the changes in PC composition on the basis of their fatty acid compositions. Major PC in skipjack flesh were those having fatty acid combinations of (C16, C22), (C22, C22), (C18, C22), (C20, C22), (C16, C18), and (C18, C20). Percentages of the PC having fatty acid combinations of (C22, C22), (C18, C22), and (C20, C22) incereased gradually during storage, while that of (C18, C22) decreased distinctly. These results indicate that the PC in skipjack flesh are preferentially hydrolyzed by endogenous lipolytic enzyme system during storage at -20°C. The molecular species of the PC preferentially hydrolyzed were the same as those in the ice-stored skipjack flesh as previously reported. This suggests that the preferential hydrolysis of PC in skipjack flesh occurs regardless of storage temperature.On the other hand, lyso-form phospholipids such as lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine accumulated in skipjack flesh during storage. The maximum amount of LPC was 89mg/100g after a 6-week storage period

Application of Selected-Ion Monitoring Gas Chromatography/Mass Spectrometry to the Analysis of Molecular Species of 1, 2-Diacylglycerophospholipids of Bonito White Muscle

The molecular species of 1, 2-diacylglycerophospholipids of bonito Euthynnus pelamis (Linna-eus) white muscle were determined by selected-ion monitoring gas chromatography/mass spectro-metry using electron impact ionization. The 1, 2-diacylglycerol tert-butyldimethylsilyl ether derivatives obtained from the glycerophospholipids were separated on a polar open-tubular column gas liquid chromatography based on the numbers of both total acyl carbons and double bonds. Peak assignment was carried out by locating the characteristic fragment ions, two types of [RCO+74]+ ions due to fatty acyl residues on sn-1 and sn-2 positions of 1, 2-diacylglycerol and [M-57]+ ions indicating the corresponding molecular weight. Consequently, the highly un-saturated 1, 2-diacylglycerophospholipids such as 20: 5n-3-20: 5n-3, 20: 5n-3-22: 6n-3 and 22: 6n-3-22: 6n-3 species were identified in the bonito white muscle

Molecular species of 1-O-alk-1\u27-enyl-2-acylglycerophospholipids of bonito white muscle.

The molecular species of 1-O-alk-1\u27-enyl-2-acylglycerophospholipids of bonito Euthynnus pelamis (I.innaeus) white muscle were determined by selected-ion monitoring gas chromatography/mass spectrometry using electron impact ionization. The 1-O-alk-1\u27-enyl-2-acylglycerol tert-BDMS ether derivatives obtained from the glycerophospholipids were separated on a polar opentubular column gas liquid chromatography on the basis of the numbers of both total acyl carbons and double bonds. Peak assignment was carried out by locating the characteristic fragment ions, [RCH=RCH+56]+ ions due to alk-1-enyl residues on sn-1 position, [RCO+74]+ ions due to acyl residues on sn-2 positions and [M-57]+ ions indicating the corresponding molecular weight. Consequently, the highly unsaturated 1-O-alk-1\u27-enyl-2-acylglycerophospholipids such as 16:0"-22:6n-3 (alkenyl-acyl) and 18:0"-22:6n-3 species were predominently present in the bonito white muscle