HDL-C concentration is related to markers of absorption and of cholesterol synthesis: Study in subjects with low vs. high HDL-C

BackgroundThe antiatherogenic functions of high density lipoprotein (HDL-C) include its role in reverse cholesterol transport, but to what extent the concentration of HDL-C interferes with the whole-body cholesterol metabolism is unknown. Therefore, we measured markers of body cholesterol synthesis (desmosterol and lathosterol) and of intestinal cholesterol absorption (campesterol and β-sitosterol) in healthy subjects that differ according to their plasma HDL-C concentrations.MethodsHealthy participants presented either low HDL-C (< 40 mg/dl, n = 33, 17 male and 16 female) or high HDL-C (> 60 mg/dl, n = 33, 17 male and 16 female), BMI < 30 kg/m², were paired according to age and gender, without secondary factors that might interfere with their plasma lipid concentrations. Plasma concentrations of non-cholesterol sterols were measured by the combined GC–MS analysis.ResultsPlasma desmosterol did not differ between the two groups; however, as compared with the high HDL-C participants, the low HDL-C participants presented higher concentration of lathosterol and lower concentration of the intestinal cholesterol absorption markers campesterol and β-sitosterol.ConclusionPlasma concentrations of HDL, and not the activities of LCAT and CETP that regulate the reverse cholesterol transport system, correlate with plasma sterol markers of intestinal cholesterol absorption directly, and of cholesterol synthesis reciprocally.     

The alarm secretory leukocyte protease inhibitor increases with progressive metabolic dysfunction

BackgroundSecretory leukocyte protease inhibitor (SLPI) is an alarm antiprotease secreted by neutrophils and mucous membranes that potently inhibits the inflammatory cascade; however, the role of SLPI in human disease remains largely unknown. We hypothesized that SLPI is related to chronic low-grade inflammatory diseases, such as metabolic syndrome (MS) or type-2 diabetes (T2DM).MethodsWe examined associations between circulating SLPI (ELISA) and quantitative traits of MS (ATPIII criteria) in 261 Caucasian men with various degrees of metabolic dysfunction. Subjects had neither MS nor T2DM (n = 140), either diagnosis (n = 44) or both diagnoses (n = 77).ResultsCirculating SLPI increased with progressive metabolic dysfunction, with a mean increase of 4.4 ng/ml (95% IC 2.4 to 6.3 ng/ml; p < 0.001) for each unit increase in the criteria used to define MS. Circulating SLPI showed independent associations with uric acid [β = 5.1 (95% CI 3.4 to 6.7), p < 0.00001], serum lipids, pulse pressure and inflammatory markers.ConclusionsCirculating SLPI increases with progressive metabolic dysfunction and is related to metabolic and inflammatory parameters in men.     

Oxidative modification of patient's plasma proteins and its role in pathogenesis of multiple sclerosis

BackgroundOxidative stress plays an important role in multiple sclerosis (MS).Objective and methodsThe present study was designed to evaluate the modifications of plasma proteins by estimation markers of oxidative/nitrosative stress: carbonyl groups and 3-nitrotyrosines (3-NT) levels in relapsing-remitting (RR) (n = 10) and secondary progressive (SP) (n = 10) clinical course of multiple sclerosis. Moreover, we estimated the level of uric acid (UA) in plasma of MS patients.ResultsCompared to controls (n = 10), the levels of carbonyl groups in plasma proteins were elevated (P < 0.0001) as well in RRMS as in SPMS. The highest concentration of 3-NT was observed in plasma proteins obtained from SPMS patients (P < 0.0005). The level of uric acid in plasma was significantly lower in RRMS (P < 0.0001) than SPMS.ConclusionThis is the first report which presented differences between SPMS and RRMS patients in 3-NT and protein carbonyl groups in plasma proteins.     

Serum soluble Fas levels in patients with autoimmune rheumatic diseases

Objective:The role of the serum soluble Fas (sFAS) system is unclear in diagnosis of several autoimmune rheumatic diseases although there are present contradictory reports on the levels of serum sFas. We therefore assessed levels of sFAS in serum of patients with autoimmune rheumatic diseases.Patients and methods:We analyzed sFas levels and their relationship to clinical and laboratory data in patients with systemic lupus erythematosus (SLE, n = 32), rheumatoid arthritis (RA, n = 28), Sjögren's syndrome (SS, n = 20) systemic sclerosis (SSc, n = 21), polymyositis/dermatomyositis (PM/DM, n = 15). Patients with osteoarthritis (OA, n = 20) and healthy volunteers (n = 20) were used as controls. Serum levels of sFAS were determined by ELISA. sFas levels greater than mean (normals) + 2 SD were considered as elevated.Results:The mean sFas values were found higher in RA, PM/DM and OA than in control although no differences were found in SSc and SS patients. The mean sFas levels in SLE patients were lower than healthy controls. Elevated sFas rates in RA, PM/DM and SS were found to be 21.4%, 60%, 10% higher than in healthy controls, respectively. sFas levels in SLE and SSc did not differ from control values. Mean sFas levels did not show significant difference between active and inactive patients in all disease groups except PM/DM, RA and OA. No correlations of sFas with relevant disease subsets, laboratory findings and treatment modalities were found.Conclusions:The findings indicate that the serum sFas molecule may provide a useful additional marker for presence and assessment of disease in patients with RA and PM/DM.     

Specific increase in serum autotaxin activity in patients with pancreatic cancer

ObjectivesTo evaluate the potential clinical significance of serum autotaxin (ATX) level in patients with cancers of the digestive system.Design and methodsSerum ATX activity was measured as the lysophospholipase D activity in patients with cancer of the esophagus (n = 8), stomach (n = 18), colorectum (n = 21), biliary tract (n = 19), or pancreas (n = 103) and in patients with benign pancreatic diseases (n = 73).ResultsAmong patients with various cancers of digestive system, increased serum ATX activity was predominantly observed among pancreatic cancer patients. Serum ATX activity was not increased in patients with chronic pancreatitis or pancreatic cysts. In the diagnosis of pancreatic cancer, the area under the receiver operating curve for serum ATX activity was 0.541 (95% CI, 0.435–0.648) for men and 0.772 (95% CI, 0.659–0.885) for women. No significant correlation was observed between serum ATX activity and CEA, CA19-9 or Dupan2 levels.ConclusionSerum ATX activity may be useful for identifying pancreatic cancer when used together with other serum markers of pancreatic cancer.     

Association between indices of body mass and antibody titers to heat-shock protein-27 in healthy subjects

ObjectivesWe have assessed the relationship between indices of adiposity and antibody titers to Hsp-27 in healthy subjects.DesignTwo-hundred and fifty subjects were studied, including 50 normal-weight subjects (body-mass-index (BMI) ?25 kg/m²), 100 overweight subjects (BMI 25 to ?30 kg/m²) (n = 100) and 100 obese subjects (BMI ≥ 30 kg/m²).ResultsAnti-Hsp27-antibody levels in obese subjects were [0.34 (0.20–0.39) absorbency unit], being significantly higher than overweight and normal-weight groups (P < 0.05). Anti-Hsp27-antibody levels in overweight subjects [0.29 (0.15–0.34) absorbency unit] were statistically higher than controls [0.18 (0.10–0.23) absorbency unit] (P < 0.05).ConclusionHigh anti-Hsp-27-antibody levels in obese-subjects without established coronary disease may be related to a heightened state of immunoactivation associated with obesity.     

Prediction of the neurological outcome with intrathecal high mobility group box 1 and S100B in cardiac arrest victims: a pilot study

ObjectivesTo investigate whether high mobility group box 1 (HMGB1) and S100B in cerebrospinal fluid (CSF) and the serum predict the neurological outcome in patients resuscitated from out-of-hospital cardiac arrest (OHCA).Materials and methodsThis study was designed as a prospective observational study. Twenty-five patients, who received standard cardiopulmonary resuscitation and post-resuscitation intensive care, were enrolled in this study. The patients were divided into two groups according to Glasgow-Pittsburgh Cerebral Performance categories (CPCs) at 6 months after return of spontaneous circulation (ROSC), Group G (n = 7, CPC 1 or 2) and Group P (n = 18, CPC ≥ 3). Their blood samples were taken at 6, 24, and 48 h after ROSC. The patients, whose CSF was sampled at 48 h, were also divided into either sub-Group G (n = 6) or sub-Group P (n = 8) at 6 months after ROSC.ResultsHMGB1 and S100B in CSF in sub-Group P were significantly higher than those in sub-Group G (HMGB1, <1.0 vs. 12.4 ng/ml, P = 0.009; S100B, 2.68 vs. 84.2 ng/ml, P = 0.007, respectively). HMGB1 in CSF was strongly correlated with S100B (σ = 0.81, P = 0.001). HMGB1 was elevated in serum at 6 h and normalized within 48 h after ROSC without any significant differences between the two groups. Serum S100B in Group P was significantly higher than that in Group G at each time point.ConclusionsThe significant elevations of HMGB1 and S100B in CSF, and S100B in serum are associated with the neurologically poor outcome in OHCA patients.     

An oxidative stress score as a combined measure of the pro-oxidant and anti-oxidant counterparts in patients with coronary artery disease

Oxidative stress plays a key role in the pathogenesis and development of atherosclerosis.AimTo evaluate the relationship between a novel oxidative stress index (reflecting both oxidative and anti-oxidant counterparts) with traditional cardiovascular risk factors and C-reactive protein (CRP) in coronary artery disease (CAD).Methods100 angiographically proven CAD and 70 control subjects (mean age: 65 ± 10 years, 110 males), underwent a global cardiovascular risk assessment and serum CRP and oxidative stress estimation. The Oxidative-INDEX was calculated after automated evaluation of serum hydroperoxides and total anti-oxidant capacity (D-ROM and OXY-adsorbent Test, Diacron, Italy) subtracting the OXY standardized variable from the ROM standardized variable.ResultsThe Oxidative-INDEX was higher in CAD with respect to control subjects (p < 0.001). A stepwise elevation in the Oxidative-INDEX levels was found depending on the number of affected vessels (p < 0.001). Oxidative stress was elevated according to the presence of diabetes (p < 0.001), smoking habit (p < 0.01), and hypercholesterolemia (p < 0.05). Oxidative-INDEX significantly correlated with aging (p ≤ 0.05) and CRP (p < 0.001). The Oxidative-INDEX increased with the number of cardiovascular risk factors (p < 0.001).After adjustment for traditional CV risk factors, the multivariate logistic regression analysis indicated the Oxidative-INDEX concentration as an independent factor for CAD (odds ratio = 1.4, confidence intervals = 1.1–1.9, p < 0.05).ConclusionOxidative stress represents a shared molecular pathway in atherosclerotic-related conditions, and its estimation by the automated Oxidative-INDEX could represent a valuable tool and a promising target in the prevention, diagnosis and treatment of CAD in the clinical setting.     

Autoantibodies to GP2, the major zymogen granule membrane glycoprotein, are new markers in Crohn's disease

BackgroundCrohn's disease (CD) is an inflammatory bowel disease (IBD) characterized by reactivity against microbial and self antigens. Zymogen granule glycoprotein 2 (GP2) was identified as the major autoantigen of CD-specific pancreatic autoantibodies (PAB).MethodsHuman GP2 was expressed in the Spodoptera frugiperda 9 (Sf9) cell line using the baculovirus system, purified by Ni-chelate chromatography, and used as antigen for anti-GP2 IgA and IgG assessment by enzyme-linked immunosorbent assays (ELISA). Antibodies to mannan of Saccharomyces cerevisiae (ASCA), PAB, and anti-GP2 were investigated in sera of 178 CD patients, 100 ulcerative colitis (UC) patients, and 162 blood donors (BD).ResultsAnti-GP2 IgG and IgA were found in 48/72 (66.7%) and 23/72 (31.9%) PAB positive and 5/106 (4.7%) and 1/106 (0.9%) PAB negative CD patients (p < 0.0001), respectively. CD patients displayed significantly higher reactivity to GP2 than UC patients and BD (p < 0.0001), respectively. Occurrence of anti-GP2 antibodies correlated with PAB reactivity (Spearmen's rho = 0.493, p < 0.00001). There was a significant relationship between the occurrence of ASCA IgG and anti-GP2 IgG (p = 0.0307).ConclusionsAnti-GP2 IgG and IgA constitute novel CD specific autoantibodies, the quantification of which could improve the serological diagnosis of IBD.     

Synergistic effects of the polymorphisms in the PAI-1 and IL-6 genes with smoking in determining their associated risk with coronary artery disease

ObjectivesTo assess the relationship between IL-6 and PAI-1 polymorphisms and coronary artery disease (CAD) and to observe the interactions between these polymorphic variants and smoking in the CAD risk.Design and methodThe study population consisted of 178 patients with angiographically documented CAD and 202 blood donors. The analyses of genetic polymorphisms were performed using the PCR-RFLP method.ResultsThe frequency of PAI-1 5G allele was higher in the entire CAD group than in control group (p = 0.04, OR = 1.35). Also the 5G allele carriers (4G5G + 5G5G) were more frequent in patients than in controls (p = 0.03, OR = 1.93). The number of women carrying 5G allele was again significantly higher among patients (OR = 10.95 p = 0.0075). The IL-6 C allele frequency was higher only in the CAD male subgroup (p = 0.035, OR = 1.44). We found synergistic and cumulative effects between specific genotype patterns and smoking in determining the risk of CAD, especially between PAI-1(4G5G + 5G5G)+IL-6(CC) and smoking (SIM = 4.18 and p = 0.0005, OR = 9.20, respectively).ConclusionsThere are synergistic and cumulative effects of 5G allele of PAI-1 polymorphism and C allele of IL-6 polymorphism with smoking in determining their associated risk with CAD.     

Association between serum cortisol and testosterone levels, opioid therapy, and symptom distress in patients with advanced cancer

ContextPatients with advanced cancer often experience symptoms such as pain, anorexia, and fatigue. Opioid therapy for the management of cancer pain may result in neurohormonal dysfunction that may contribute to a patient’s symptom burden.ObjectivesTo examine the association between serum cortisol and testosterone levels, opioid therapy, and symptom distress in patients with cancer.MethodsA retrospective chart review was performed on 77 consecutive patients with advanced cancer referred for symptoms of fatigue or cachexia. We collected information regarding cortisol levels (am or random), testosterone levels (men only), morphine equivalent daily dose (MEDD), and symptom severity measured by the Edmonton Symptom Assessment Scale. Nonparametric correlation analysis was performed.ResultsThe median age was 63 years (range 24–79), and 62% were men (n = 48). Most patients had gastrointestinal (n = 33, 43%) or thoracic (n = 21, 27%) malignancies and were Caucasian (n = 46, 60%). The median random cortisol level was 19.1 μg/dL (Q1–Q3, 13.4–23.8 [normal, 4.3–22.4]), which correlated with MEDD (Spearman coefficient, 0.25, P = 0.032) and symptoms including pain (0.50, P < 0.001), fatigue (0.29, P = 0.012), nausea (0.34, P = 0.003), depression (0.24, P = 0.032), and anxiety (0.25, P = 0.031). Pain and nausea remained significant after Bonferroni correction. Median morning cortisol level (n = 28) was 20.6 μg/dL (Q1–Q3, 16.6–25.4) and significantly correlated with pain (0.55, P = 0.003) after Bonferroni correction. Patients with a MEDD <30 mg/day had a mean random cortisol level of 16.6 μg/dL, whereas patients with a MEDD ≥30 mg/day had a mean random cortisol level of 20.6 μg/dL (P = 0.01). In 44 male patients with cancer, MEDD was inversely correlated with the total testosterone level (?0.52, P = 0.001).ConclusionIn patients with advanced cancer, elevated random cortisol levels were associated with pain and opioid use, although abnormally low levels of cortisol were found to be infrequent. Patients on higher opioid therapy (MEDD >30) had increased cortisol levels, and male patients had lower testosterone levels. Our study suggests that opioid therapy in patients with advanced cancer may inhibit gonadal function while sparing the adrenal axis. Future studies are needed.     

Comparison of different anthropometric indices for identifying dyslipidemia in school children

BackgroundAnthropometric indices have been associated with dyslipidemia.ObjectiveTo compare the abilities of BMI, waist circumference (WC) and WC/height to identify children's dyslipidemia.MethodsStudents 1261 (639 male) age 9.5 ± 2.1 years. were examined for anthropometry and lipid levels. Triglycerides ≥ 1.69 mmol/L and high-density lipoprotein cholesterol (HDL-C) < 0.91 mmol/L were considered abnormal per American Heart Association.ResultsThe prevalence of abnormal triglycerides was 4.1% and HDL-C 8.1%. The areas under the receiver operator curves (ROC) were: BMI = 0.87, WC = 0.83, and WC/height = 0.84 in predicting both low HDL-C and high triglycerides. Multiple regression analyses showed that the odds ratios (OR) were highest for WC [6.5], followed by WC/height [5.4], and BMI [4.9], for dyslipidemia.ConclusionsThe results suggest that WC, WC/height, and BMI similarly predicted dyslipidemia, using ROC analyses. However, regression analyses showed that WC followed by WC/height was most predictive of dyslipidemia.     

Osteoprotegerin (OPG) and TNF-related apoptosis-inducing ligand (TRAIL) levels in malignant and benign pericardial effusions

ObjectivesOsteoprotegerin (OPG) is a regulator of bone and vascular homeostasis and acts as a decoy receptor for proapoptotic TNF-related apoptosis-inducing ligand (TRAIL).Design and methodsWe assessed pericardial and serum levels of OPG and TRAIL in pericardial effusions (PE) of malignant (mPE, n = 24) or non-malignant (nPE, n = 34) origin, and in pericardial fluid (PF, n = 25) of coronary artery disease (CAD) patients by ELISA.ResultsOPG was at least 5fold higher in PE or PF compared to serum, with a significantly higher ratio of pericardial to serum OPG in patients with mPE or nPE compared to PF (mPE vs. PF, p = 0.011; nPE vs. PF, p < 0.001). TRAIL was only detectable in mPE and PF. Logistic regression analysis revealed that a high ratio of pericardial to serum OPG and high TRAIL in PE were the best variable combination to predict malignancy of PE.ConclusionsPericardial and systemic OPG or TRAIL are potential diagnostic tools to discriminate between malignant or benign PE.     

HOMA-IR and non-HDL-C as predictors of high cholesteryl ester transfer protein activity in patients at risk for type 2 diabetes

Background and aimsMetabolic syndrome (MS) and type 2 diabetes are highly associated with an abnormal lipoprotein profile, which may be generated and accentuated by high cholesteryl ester transfer protein (CETP) activity. Given the difficulty in measuring CETP activity, the aim was to identify simple biochemical predictors of high CETP activity.Design and methodsEighty five subjects at risk for type 2 diabetes were classified according to the presence of MS. Lipoprotein profile, HOMA-IR and endogenous CETP activity were evaluated.ResultsAs expected, MS patients presented higher concentration of glucose, insulin, triglycerides and non-HDL-C and lower HDL-C levels. Moreover, MS patients exhibited increased HOMA-IR and CETP activity. Employing a ROC curve for MS, high CETP activity was defined as > 250% ml^? 1 h^? 1. The predictive variables of high CETP were non-HDL-C ≥ 160 mg/dl (OR = 11.1;95%IC = 3.3–38.2;p < 0.001) and HOMA-IR > 2.1 (OR = 4.4;95%IC = 1.3–14.8;p < 0.05).ConclusionsHigh non-HDL-C and insulin resistance were predictors for increased CETP activity which measurement is not accessible for clinical laboratories.     

Effects of a single dose of oral iron on hepcidin concentrations in human urine and serum analyzed by a robust LC-MS/MS method

BackgroundThe measurement of serum hepcidin, a peptide hormone that regulates iron metabolism, is clinically important to the understanding of iron homeostasis in health and disease. To date, the quantification of serum hepcidin levels by conventional immunological detection methods has proven problematic due to challenges in obtaining high quality antibodies which demonstrate good reproducibility. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) has been employed recently for more sensitive quantification of hepcidin; however, this method has high background levels and therefore less than optimal specificity.MethodsIn order to increase the specificity of the mass spectrometry based assay, we developed a robust, ultra-performance liquid-chromatography-tandem mass spectrometry (UPLC-MS/MS) protocol using multiple selected reaction monitoring (mSRM) for quantification of hepcidin levels in urine and serum of human subjects. With this assay, we assessed levels of hepcidin before and for up to 8 h after oral ingestion of ferrous sulfate in ten adult human subjects without known disease.ResultsThe linear response of hepcidin quantitation on each instrument was measured, and the correlation coefficients of these calibrations were r² = 0.9512 ± 0.0202 (n = 5) for urine and r² = 0.9709 ± 0.0291 (n = 5) for serum [r² = mean ± SD]. Compared to baseline, the levels of urinary hepcidin between 2–4 h and 4–8 h of both women and men showed significant increases with p < 0.05 and p < 0.001, respectively. The levels of serum hepcidin between 4 h and 8 h in both women and men showed significant increases, compared with baseline values, with both p < 0.01. Interestingly, we also observed some degree of oscillation of levels, occurring at later time points.ConclusionsWe have developed and validated a new method for measuring hepcidin concentrations in human serum and urine and used it to demonstrate early increases with iron supplement in both urinary and serum levels of hepcidin, which return to baseline levels, except in urine samples from men.     

Cytokine elevations in acute coronary syndrome and ovarian cancer: a mechanism for the up-regulation of the acute phase proteins in these different disease etiologies

Objectives:To identify if a common set of cytokines is elevated in both ovarian cancer and acute coronary syndrome (ACS).Design and methods:A cytokine array (Randox Ltd) was measured in healthy women (n = 33), women with ACS (n = 21) and ovarian cancer (n = 45).Results:Women with ACS or ovarian cancer had higher concentrations of IL-6, IL-8, VEGF, MCP-1, and EGF as compared to healthy volunteers.Discussion:Common cytokine elevations are present in both ACS and ovarian cancer.     

Pro-inflammatory and atherogenic circulating factors in non-alcoholic fatty liver disease associated to metabolic syndrome

BackgroundIt is not elucidated if liver fat deposits associated to metabolic syndrome (MS) aggravate the atherogenic state. We evaluated, in MS patients, if the presence of non-alcoholic hepatic steatosis (HS) determines differences in inflammatory markers and VLDL characteristics.MethodsSeventy-five patients with MS were divided into 2 groups depending on the presence or absence of HS, assessed by ultrasound. Lipid profile, free fatty acids (FFA), VLDL composition, adiponectin, tumor necrosis factor-alpha (TNF-α), high sensitivity C-reactive protein (hs-CRP), and soluble adhesion molecules (sVCAM-1 and sICAM-1) were measured.ResultsHS patients presented increased triglycerides levels, HOMA-IR and FFA. Patients with HS showed a reduction in adiponectin (p = 0.04) and increase in hs-CRP (p = 0.02), independently of insulin-resistance (IR). FFA correlated positively with TNF-α (p = 0.04) and inversely with adiponectin (p = 0.01). hs-CRP correlated with all inflammatory markers, independently of IR: TNF-α (r = 0.34, p = 0.02), sVCAM-1 (r = 0.29 p = 0.03), sICAM-1 (r = 0.56, p = 0.01), adiponectin (r = ?0.34, p = 0.04). HS patients presented higher VLDL mass and number of particles. Adiponectin correlated with VLDL cholesterol content (r = ?0.47, p = 0.04), independently of IR. VLDL, once secreted, would suffer from changes, becoming more atherogenic.ConclusionsSimple HS would play an important role increasing cardiovascular risk, independently of IR. hs-CRP may represent a useful biomarker of this condition.     

Assessment of circulating proteasome chymotrypsin-like activity in plasma of patients with acute and chronic leukemias

ObjectiveWe evaluated whether the proteasomal chymotrypsin-like (ChT-L) activity is increased in plasma of patients with acute lymphoblastic (ALL), acute myeloblastic (AML) and chronic lymphocytic (CLL) leukemias.MethodsThe activity was assayed using the fluorogenic peptide substrate in the presence of an artificial activator sodium dodecyl sulfate (SDS) in the plasma of healthy donors (n = 15) and ALL (n = 15), AML (n = 28) and CLL (n = 22) patients.ResultsThe activity was significantly (P < 0.001) higher in the plasma of ALL and AML patients at the diagnosis than in healthy subjects and decreased after therapy or remained unchanged or rose during relapse. By contrast, in CLL patients at the diagnosis, the activity did not differ significantly from the healthy controls. In each group, the activity positively correlated with the serum lactic dehydrogenase activity.ConclusionsPlasma proteasome ChT-L activity can be a useful bio-marker for patients with acute leukemia at the blast stage.     

Enzymatic assay of phosphatidylethanolamine in serum using amine oxidase from Arthrobacter sp

BackgroundIn human serum, as for phospholipids not containing choline, phosphatidylethanolamine (PE) exists approximately 5% in a whole phospholipid. PE is well known as one of the main components of biological membranes, and also plays important roles that contribute to apoptosis and cell signaling. However, it could not measure PE with other phospholipids due to a lack of choline in them.MethodsUsing an amine oxidase (EC 1.4.3.6), from Arthrobacter species, a simple and rapid enzymatic assay for measurements of PE in serum was established. That assay used the Hitachi 7170 analyzer to evaluate the analytical performance.ResultsThe average within-run CVs were 0.38–1.27% (n = 20) at 69–160 μmol/l. The correlation between values obtained with the present method (y) and the high-performance liquid chromatography (HPLC) method (x) was: y = 0.944x + 9.441 (r = 0.977, S_y|x = 5.82, n = 34). In addition, the reference interval of healthy subjects was 115 ± 45 μmol/l.ConclusionsThis new enzymatic method shows a high specificity for serum PE and can be easily applied to an automated analyzer. The present method is available as a novel marker of changes in the clinical condition of serum phospholipids.     

Predominance of large VLDL particles in metabolic syndrome, detected by size exclusion liquid chromatography

ObjectiveTo study size heterogeneity of triglyceride rich lipoproteins (TRL) in metabolic syndrome (MS).Design and methodsThirty MS patients and 14 healthy subjects were included. In fasting serum we measured: lipid profile, free fatty acids (FFA) and adiponectin; TRL were isolated (d < 1.006 g/mL) and analysis by size exclusion HPLC followed by UV detection was performed; each subfraction was expressed as percentage of total TRL.ResultsMS patients, even those with normal triglycerides, presented higher proportion of very large VLDL (90 nm diameter) and large VLDL (60 nm) and slightly lower of typical VLDL (37 nm) (p < 0.04); increased FFA (p = 0.04) and lower adiponectin (p = 0.001). FFA correlated with large VLDL% (r = 0.58; p = 0.003), independently of insulin-resistance and waist. Furthermore, the lower the adiponectin, the greater the predominance of large VLDL (r = ? 0.40; p = 0.04).ConclusionMS was associated with large VLDL, described as more atherogenic beyond triglyceride levels. Size exclusion HPLC would represent a useful tool for assessing subfractions' lipoprotein profile.