The present study was designed to evaluate the metabolism of chylomicron and chylomicron remnants by measuring serum apolipoprotein B-48 (apoB-48) levels in 335 normolipidemic and 253 hyperlipidemic subjects using a novel ELISA system. The distribution of fasting serum apoB-48 levels in normolipidemic subjects varied widely, ranging from Ͻ 1 to Ͼ 24 g/ml (mean, 5.2 ؎ 3.8 g/ml; median, 3.9 g/ml). Serum apoB-48 levels correlated with serum triglyceride (TG) concentrations ( r ‫؍‬ 0.45, P Ͻ 0.001), but not with total cholesterol levels. Serum apoB-48 levels were 7 to 18 times higher in patients with Type I, Type V, and Type III hyperlipidemia, and only slightly higher in patients with Type IIa, Type IIb, and Type IV hyperlipidemia, compared with normolipidemic subjects. The calculated apoB-48/ TG ratio was elevated only in patients with dysbetalipoproteinemia (apoE2/2 phenotype). In normolipidemic subjects, oral fat loading resulted in about 2-fold increase in serum apoB-48 levels, with a peak level recorded at 3-4 h postloading, and then returned to the baseline level within 6 h. On the other hand, in patients with dysbetalipoproteinemia, serum apoB-48 levels did not change considerably. Our results indicate that serum apoB-48 is a very useful parameter for evaluating lipoprotein metabolism in exogenous pathways. The pathogenic role of hypertriglyceridemia in atherosclerosis has long been elusive. A recent meta analysis of several cohort studies revealed that plasma triglyceride (TG) level is an independent risk factor for cardiovascular diseases (1). The relationship between plasma TG levels and atherosclerotic diseases has often been discussed in relation to postprandial hyperlipidemia (2-7). Several studies have pointed to the relationship between the impaired metabolism of postprandial TG-rich lipoproteins (TRLs) and the presence or development of coronary heart disease (CHD). A mechanistic hypothesis linking the postprandial generation of TRL remnants (products of lipolytic degradation of TRL produced by the liver, VLDL, and by the intestine chylomicrons) to the development of atherosclerosis was formulated almost 20 years ago by Zilversmit (8). TG-depleted remnants are considered to be atherogenic because they can penetrate the mucosal lining of the arterial wall and become entrapped within the subendothelial space. Thus, accurate evaluation of the kinetics of chylomicron and chylomicron remnants is very important.Chylomicrons are secreted by the intestine after fat ingestion. Chylomicron particles contain apolipoprotein B-48 (apoB-48) as the structural protein, which in humans is formed exclusively in the intestine after tissue-specific editing of the apoB-100 mRNA (9, 10). Different methods are used for estimation of postprandial lipoproteins. A number of studies have made use of retinyl palmitate (RP) labeling of chylomicrons, together with postprandial plasma TG quantification. The RP technique has shortcomings as it has recently been shown that RP can exchange between lipoprotein species in pla...

Visceral and subcutaneous adipose tissue masses (ATMs) were determined by magnetic resonance imaging and total ATM by bioelectrical impedance. Results: In univariate regression, plasma adiponectin and leptin concentrations were inversely and directly associated with plasma apoB-48, apoC-III, RLP-cholesterol, triglycerides, VLDL-apoB, and VLDL-triglycerides (P <0.05). Resistin, IL-6, and TNF-␣ were not significantly associated with any of these variables, except for a direct correction between apoC-III and IL-6 (P <0.05). In multivariate regression including HOMA, age, nonesterified fatty acids, and adipose tissue compartment, adiponectin was an independent predictor of plasma

Peptidylarginine deiminases (PADs) are posttranslational modification enzymes that convert protein arginine to citrulline residues in a calcium ion-dependent manner. Previously, we reported the abnormal accumulation of citrullinated proteins and the increase in the amount of PAD2 in hippocampi from Alzheimer's disease (AD) patients. Moreover, glial fibrillary acidic protein (GFAP), an astrocyte-specific marker protein, and vimentin were identified as citrullinated proteins by using two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry. To clarify the substrate specificity of PADs against GFAP, we prepared recombinant human (rh)PAD1, rhPAD2, rhPAD3, rhPAD4, and rhGFAP. After incubation of rhGFAP with rhPAD1, rhPAD2, rhPAD3, and rhPAD4, citrullinated (cit-)rhGFAP was detected by Western blotting. The citrullination of rhGFAP by rhPAD2 was unique, specific, and time dependent; additionally, rhPAD1 slightly citrullinated rhGFAP. We then generated eight anti-cit-rhGFAP monoclonal antibodies, CTGF-125, -128, -129, -1212, -1213, -1221, -122R, and -1224R, which reacted specifically with cit-rhGFAP. Two of those eight monoclonal antibodies, CTGF-122R and -1224R, reacted with both cit-rhGFAP and rhGFAP in Western blots. By using the CTGF-1221 antibody and a tandem mass spectrometer, we identified the two independent citrullination sites (R270Cit and R416Cit) of cit-rhGFAP. Immunohistochemical analysis with CTGF-1221 antibody revealed cit-GFAP staining in the hippocampus of AD brain, and the cit-GFAP-positive cells appeared to be astrocyte-like cells. These collective results strongly suggest that PAD2 is responsible for the citrullination of GFAP in the progression of AD and that the monoclonal antibody CTGF-1221, reacting with cit-GFAP at R270Cit and R416Cit, is useful for immunohistochemical investigation of AD brains.

Insertion (I)/deletion (D) polymorphism of the angiotensin converting enzyme (ACE) gene has been reported to be involved in various cardiovascular diseases. We investigated prospectively whether the response to the ACE inhibitor imidapril varied according to the ACE genotype or plasma ACE activity in Japanese hypertensive patients. The study population consisted of 57 hypertensive patients. After a 4-week observation period, imidapril was administered at a dose of 5 mg/day and blood pressure was measured every 2 weeks for 6 weeks. The plasma ACE activity in patients with the DD or ID genotype was significantly higher than that in patients with the II genotype. Neither the reduction nor the percent reduction in systolic blood pressure was significantly different between patients with either the DD or ID genotype and patients with the II genotype (DD or ID v II, 18.8 +/- 2.4 v 20.2 +/- 3.3 mm Hg; P = NS, 10.9 +/- 1.4 v 11.7 +/- 1.9%; P = NS, respectively). However, both the reduction and the percent reduction in diastolic blood pressure tended to be higher in patients with the II genotype (DD or ID v II, 7.9 +/- 1.2 v 12.4 +/- 2.2 mm Hg; P = .0669, 8.1 +/- 1.2 v 12.4 +/- 2.2%; P = .0569, respectively). The reduction in diastolic blood pressure was inversely correlated with plasma ACE activity (r = 0.301, P = .0253). In conclusion, the response to imidapril in hypertensive patients is determined at least in part by the ACE genotype.

Background: In an immunofluorescence study using antibody to podocalyxin, we reported that urinary excretion of podocytes reflected podocyte injury in glomeruli. However, this method has some problems, since it is basically urine cytology. To overcome problems with this test, we measured whole podocalyxin content in urine sediment by enzyme-linked immunosorbent assay (ELISA). Methods: Urinary sediment podocalyxin (u-sed-PCX) content of the first morning urine was quantified by ELISA after solubilization by detergent. We measured urine samples from children with various glomerular diseases and from healthy volunteers as controls. The glomerular diseases were classified into two categories: group I (inflammatory glomerular, 5 diseases) and group II (non-inflammatory glomerular, 3 diseases). Results: (1) The level of u-sed-PCX was significantly higher in the urine from patients with glomerular diseases (groups I and II, median (interquartile range (IQR)): 2 (0.6–18.5), n = 111) compared with controls (0 (0–0.4), n = 135), and the level of u-sed-PCX in group I diseases (3.4 (0.6–27.2), n = 90) was significantly higher than those in group II diseases (0.9 (0.1–2.5), n = 21). (2) The presence of PCX in urine sediment was confirmed by Western blot analysis. (3) The degree of proteinuria was significantly correlated with the level of u-sed-PCX in group I (r_s = 0.539, p < 0.001), but not in group II. (4) In group I, the level of u-sed-PCX was significantly higher in the acute phase than in the chronic phase (p < 0.01). (5) Comparison of histological findings of renal biopsies with u-sed-PCX showed a significant correlation in acute extracapillary lesions (p < 0.05). (6) Persistent high level of u-sed-PCX paralleled good histological progression in renal biopsies. Conclusion: Quantification of urinary sediment podocalyxin by ELISA is a reliable and useful laboratory marker for the estimation of the severity of active glomerular injury and a urinary index of acute extracapillary changes.