Lack of association between paraoxonase 1 Q192R polymorphism and multiple sclerosis in relapse phase: A case-control study

ObjectivesThe aim of this study was to estimate the serum activity of paraoxonase 1(PON1) and assess the distribution of PON1 polymorphisms in MS patients in the relapse phase.Design and methodsPON1 and arylesterase (ARE) serum activities were measured in two equal groups (each group 63 cases) of relapsing–remitting MS patients and healthy individuals.ResultsMean values for serum PON1 and ARE activities were 90.3 ± 63.4 and 182.1 ± 128.7 IU/L for patients and 99.9 ± 73.3 and 190.8 ± 150.3 IU/L for controls. Those values were not statistically significant (p = 0.242 and p = 0.378), respectively. Comparing genotype distributions and allele frequencies in both groups for PON1 Q192R and PON L55M polymorphisms did not show any statistical difference.ConclusionIn a selected group of MS patients in relapsing phase no statistically significant difference in PON1 and ARE activities was detected but the mean values for the serum enzyme activities were lower in MS patients.     

Is serum transthyretin a reliable marker of nutritional status in patients with end-stage renal disease?

ObjectiveTo test the value of serum transthyretin (TTR) concentration as a nutritional marker in renal patients.MethodsThe study included 115 renal patients, out of which 35 are on conservative treatment, 50 on hemodialysis and 30 renal transplant recipients, and 31 healthy control subjects. Serum TTR, albumin, transferrin, C-reactive protein (CRP) and α1 anti trypsine (AAT) were assessed by immunoturbidimetry, and vitamin A by HPLC. Linear regression models were applied to test the association between serum TTR and body mass index (BMI).ResultsSerum TTR concentrations were normal, but serum vitamin A, CRP and AAT concentrations were significantly higher in patients. In renal patients, serum TTR was positively and independently related to BMI and was significantly lower in malnourished than well-nourished patients (367 ± 91 vs. 417 ± 130 mg/L; p = 0.05). The risk of serum TTR < 300 mg/L was higher in malnourished patients [OR, 4.82 (1.78–13.2); p = 0.001].ConclusionSerum TTR concentrations were at normal range in renal patients despite evidence of malnutrition and inflammation. However, they were related to BMI and were significantly lowered in malnourished patients. Thus, serum TTR would reflect nutritional status in renal patients. However, the cutoff of malnutrition should be raised to 300 mg/L.     

The influence of smoking on semen quality, seminal microelements and Ca2+-ATPase activity among infertile and fertile men

ObjectiveTobacco smoking is now increasing rapidly throughout the developing world and is one of the biggest threats to current and future world health. Several studies have addressed the role of cigarette smoking on semen quality, but the exact mechanisms remain inconclusive. In order to evaluate the detrimental effects of smoking on semen quality among Saudi subjects, the levels of different seminal parameters in smokers were compared to non-smokers.Patients and methodsA total of 159 semen samples (61 smokers and 98 non-smokers) from men attending an infertility clinic for routine infertility workup were sub-grouped into fertile or infertile and were compared based on standard semen analysis (according to WHO guidelines), content of metals (magnesium, zinc and cadmium) and plasma membrane Ca²⁺-ATPase activity of sperms.ResultsCadmium concentration was found significantly higher in smokers than in non-smokers either in fertile or infertile group (2.9 ± 0.4 vs 1.4 ± 0.7; 2.9 ± 0.5 vs 1.3 ± 0.7 μg L^? 1; respectively). Together with this increase in seminal Cd a significant decrease in Ca²⁺-ATPase activity (21.5 ± 2.8 vs 33.71 ± 1.2; 20.7 ± 1.5 vs 35.07 ± 2.9 mmol min^? 1 mg^? 1 protein, p < 0.05), decrease in seminal zinc (109.8 ± 8.1 vs 189.7 ± 9.9 mg L^? 1, p < 0.01) and decrease in sperm motility (41.9% ± 2.9 vs 46.01% ± 2.5; 9.8% ± 2.4 vs 15.3% ± 2.7, p < 0.05) were found.ConclusionOur data demonstrate that cigarette smoking affects both Ca²⁺-ATPase activity and motility of the spermatozoa. These effects may be attributed to increased seminal cadmium and reduced zinc concentrations.     

Specific, rapid, and sensitive enzymatic measurement of sphingomyelin, phosphatidylcholine and lysophosphatidylcholine in serum and lipid extracts

ObjectiveHuman serum sphingomyelin (SM) and phosphatidylcholine (PC) play important roles in the development of atherosclerosis. However, there are no rapid and sensitive methods for SM and PC measurement. The present report describes a novel enzymatic method for measuring SM, PC and lysophosphatidylcholine (lyso-PC) levels in plasma and lipid extracts.Design and methodsThe total choline-containing phospholipids (total PL), SM and PC were measured using a two-reagent system involving specific enzymes for choline-based phospholipids. The procedure was performed using either microplate or automatic analyzer technology. The concentration of lyso-PC was calculated by subtracting the concentration of SM plus PC from the total PL concentration.ResultsAssay results showed linear correlations between sample concentration and absorbance. The within-run and between-run coefficients of variation for PC, SM, and lyso-PC concentrations were 2.0–4.4% for the microplate analyzer and 0.9–2.9% for the automatic analyzer. Analysis of normal human serum showed that the total PL concentration strongly correlated with the SM plus PC concentration (r = 0.9850). There were moderate correlations between serum PC and SM levels (r = 0.6228) and between serum PC and lyso-PC levels (r = 0.7806). SM, PC, and lyso-PC levels in normal human serum (n = 50) were 0.54 ± 0.07, 1.99 ± 0.22 and 0.60 ± 0.15 mmol/L, respectively.ConclusionThe present enzymatic method allowed for rapid, simple, and accurate measurement of SM, PC, and lyso-PC levels in lipid extracts and in serum. The method is suitable for both microplate and automatic analyzer assays.     

Serum autotaxin measurements in pregnant women: application for the differentiation of normal pregnancy and pregnancy-induced hypertension

BackgroundThe bioactive lipid lysophosphatidic acid (LPA) exerts multiple effects in the female reproductive system. Serum/plasma LPA is mainly produced by the lysophospholipase D activity of autotaxin (ATX). Previous studies have suggested that ATX has critical roles in cancer, reproduction, and vascular development. In the present study, we evaluated the usefulness of serum ATX measurements in pregnant women.MethodsWe measured the serum ATX antigen levels in 32 normal pregnant women, 15 patients with pregnancy-induced hypertension (PIH), and 7 patients with preterm delivery using a recently developed automated enzyme immunoassay.ResultsThe serum ATX antigen levels in normal pregnant women were significantly higher than those in non-pregnant women (P < 0.001). The serum ATX antigen levels in normal pregnant women were significantly and positively correlated with the gestational week (r = 0.809, P < 0.001). During the third trimester, the serum ATX antigen levels of the patients with PIH (3.299 ± 1.720 mg/l) were significantly lower than those of the normal pregnant women (4.915 ± 2.323 mg/l) (P = 0.04).ConclusionsThe serum ATX antigen level increases with the progression of pregnancy. The serum ATX level may be a serological marker for the prediction of PIH.     

Serum tartrate-resistant acid phosphatase 5b (TRACP5b) activity as a biomarker for bone metastasis in non-small cell lung cancer patients

BackgroundDiagnosis and follow-up of bone metastasis (BMet) in non-small cell lung cancer (NSCLC) patients usually rely on symptoms and image studies. A serum marker of bone resorption may improve the quality of treatment in such patients. Tartrate-resistant acid phosphatase 5b (TRACP5b) is a specific marker for osteoclasts and we proposed it can be used as a marker of BMet in NSCLC patients.MethodsIn November 2002 till August 2008 serum samples were obtained from 141 newly diagnosed stage IIIA, IIIB or IV NSCLC patients and 41 normal subjects. All patients received baseline bone scintinography examination and evaluation of clinical symptoms as a standard of BMet diagnosis. Patients were divided into 2 groups by having BMet (Group I, n = 72) or not (Group II, n = 69). An in-house immunoassay using a TRACP-specific monoclonal antibody, 14G6, was used to measure the serum TRACP5b activity at pH 6.1.ResultsThe mean serum TRACP5b activities of Group I, Group II and normal subjects were 3.50 ± 2.23 U/l, 2.09 ± 0.72 U/l and 2.33 ± 0.52 U/l, respectively. After adjusting for age, stage, gender, and histology in a generalized linear model, Group I has significantly higher TRACP5b activity than Group II (p < 0.001). The receiver operating characteristic analysis established a cutoff value of 2.551 U/l to identify BMet in NSCLC patients with a sensitivity of 63.9% and a specificity of 76.8%. TRACP5b activity declined in patients who responded to treatment (p = 0.047), and elevated in patients who developed new BMet (p = 0.05).ConclusionsSerum TRACP5b activity test is a potentially useful adjunct in diagnosing and monitoring BMet in NSCLC. Further study is warranted to establish its real value in diagnosis and monitoring of BMet in NSCLC patients.     

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.     

Association of beta 1-adrenergic receptor gene polymorphisms with left ventricular hypertrophy in human essential hypertension

ObjectivesExperimental evidence support a key role for beta (1)-adrenergic receptor (ADRB1) in the modulation of cardiac mass. This relationship has not yet been described in Chinese population. The goal of our study was to investigate the relationships between ADRB1 gene polymorphisms and left ventricular structure in human essential hypertension.Design and methodsA total of 2417 hypertensive patients were successfully investigated. The polymorphisms of ADRB1 gene (Arg389Gly and Gly49Ser) were genotyped by using PCR-RFLP and confirmed by sequencing.ResultsPatients carrying the Arg389Arg genotype had an increase in the left ventricular septal thickness (10.4 ± 1.5 mm vs. 9.6 ± 1.5 mm, P < 0.01 or 9.4 ± 1.4 mm, P < 0.01); left ventricular posterior wall thickness (10.4 ± 2.4 mm vs. 9.6 ± 2.4 mm or 9.7 ± 2.9 mm, P < 0.01); left ventricular mass index (51.6 ± 13.3 g/m^2.7 vs. 44.6 ± 12.9 g/m^2.7, P < 0.01 or 43.2 ± 14.4 g/m^2.7, P < 0.01) and relative wall thickness (45.0 ± 9.0% vs. 42.6 ± 8.1%, P < 0.01 or 43.2 ± 8.8%, P < 0.01) as compared with those carrying genotypes Arg389Gly and Gly389Gly. These associations were independent of anthropometric factors and major clinical features and were replicated in another independent hypertensive population (n = 327).ConclusionsOur findings show that the Arg389Gly polymorphism of the ADRB1 gene confers higher risk of left ventricular hypertrophy in human essential hypertension.     

Diabetes in pregnancy: Effect on glycation and acetylation of the different chains of fetal and maternal hemoglobin

BackgroundMeasurement of glycated fetal hemoglobin to assess maternal glycemic control is unreliable. Electrospray ionization–mass spectrometry (ESI-MS) has been suggested as a definitive procedure.ObjectiveThis study aimed to evaluate glycation and acetylation by ESI-MS of the separate chains of neonatal fetal hemoglobin in comparison with glycation of maternal hemoglobin, to assess the impact of maternal diabetes.MethodsTwenty-nine non-diabetic (31 neonates) and 15 diabetic women (15 neonates) were recruited. Whole blood was collected at delivery from the mothers and cord blood from their respective neonate. The blood samples were diluted in acetonitrile:water (50:50) and treated with a cation exchange resin to remove sodium and potassium adducts on the hemoglobin. The α- and β-chain glycated maternal hemoglobin and α- and γ-chain glycated and acetylated hemoglobin of the neonate were measured by ESI-MS. HbA1c was measured on the Menarini 8160.ResultsMean α- and γ-chain and overall glycated hemoglobin and acetylated fetal hemoglobin were 1.23 ± 0.41%, 1.62 ± 0.47%, 1.24 ± 0.37%, and 8.56 ± 0.84% in the infant of the non-diabetic mother (INDM) and 1.39 ± 0.21%, 1.92 ± 0.61%, 1.64 ± 0.59%, and 8.44 ± 0.63% in the infant of the diabetic mother (IDM). Mean maternal α- and β-chain, overall glycated hemoglobin and HbA1c were 1.98 ± 0.38%, 4.28 ± 0.76%, 3.13 ± 0.51%, 5.39 ± 0.39% (non-diabetic) and 2.40 ± 0.83%, 4.71 ± 0.90%, 3.58 ± 0.83%, 6.15 ± 0.71% (diabetic). Overall glycated hemoglobin levels were significantly higher in the IDM (p = 0.006) compared to the INDM. Maternal glycated hemoglobin was significantly higher than neonatal glycated hemoglobin in the control (p < 0.0001) and diabetic group (p < 0.0001). A significant correlation was observed between maternal glucose concentration and overall glycated fetal hemoglobin in the IDM (p = 0.02). Glucose concentrations in the diabetic mother and the IDM were not significantly different (p = 0.5) and were significantly correlated (p < 0.0001). HbA1c was not significantly different in the two maternal groups. No significant difference was observed between AcHbF in IDM or INDM (p = 0.61).ConclusionsMeasurement of overall glycated fetal hemoglobin, incorporating α- and γ-chain glycations, seems best to assess abnormal glucose homeostasis during pregnancy. Accurate assay of this parameter is critical for stratification of risk of possible post birth developmental complications.     

Glycated albumin is independently associated with estimated glomerular filtration rate in nondiabetic patients with chronic kidney disease

BackgroundGlycated albumin (GA) may contribute to diabetic nephropathy, but the clinical significance of GA in patients with chronic kidney disease (CKD) is unknown.MethodsPatients were classified with the NKF/DOQI classification system as mild (stage I, II), moderate (stage III), or advanced CKD (stage IV). Those undergoing dialysis or with CKD stage V were excluded. GA was measured using the Lucica TM GA-L assay kit. The relationship between GA and renal dysfunction was analyzed in patients with or without diabetes.ResultsA total of 187 subjects were enrolled. GA values in those with normal, mild, moderate and advanced CKD were 18.4 ± 1.4%, 18.4 ± 3.1%, 19.0 ± 3.8%, 20.4 ± 6.4%, respectively, in diabetic patients (N = 67, p = 0.5), and were 14.1 ± 1.9%, 14.2 ± 2.2%, 15.9 ± 1.9%, 15.0 ± 1.7%, respectively, in nondiabetic patients (N = 120, p = 0.004). GA value was negatively correlated to eGFR in nondiabetic patients (r = ?0.35, p < 0.001) but not in diabetic patients (r = ?0.11, p = 0.39). In the adjusted model, GA is independently correlated to eGFR only in nondiabetic subjects.ConclusionsIncreased GA concentrations are independently associated with renal dysfunction in nondiabetic patients with CKD.     

Decreased serum brain-derived neurotrophic factor concentration in young nonobese subjects with low insulin sensitivity

ObjectiveInsulin resistance and type 2 diabetes are associated with an increased risk of neurodegenerative diseases. Decreased brain-derived neurotrophic factor (BDNF) levels might play a role in the pathogenesis of neuropsychiatric disorders. The aim of our study was to estimate serum BDNF concentration in nonobese women divided into subgroups according to their insulin sensitivity.Design and methodsWe studied 46 young, healthy, nonobese women. Insulin sensitivity was estimated with the euglycemic–hyperinsulinemic clamp technique. Then, participants were divided into subgroups of high (mean, 12.79 ± 2.01 mg/kg fat-free mass/min) and low insulin sensitivity (mean, 7.33 ± 1.66 mg/kg fat-free mass/min).ResultsWe observed decreased serum BDNF concentration in women with low insulin sensitivity in comparison to high insulin sensitivity group (3306.11 ± 603.10 vs 4141.91 ± 755.37 pg/mL, p = 0.001). Serum BDNF was positively related to insulin sensitivity (r = 0.43, p = 0.003). This correlation remained significant after adjustment for other estimated parameters.ConclusionsSerum BDNF is decreased in young nonobese women with low insulin sensitivity. Early detection and prevention of insulin resistance might be useful in the prevention of neurodegenerative disorders.     

Relationship of age-related concentrations of serum FSH and LH with bone mineral density, prevalence of osteoporosis in native Chinese women

BackgroundFollicle-stimulating hormone (FSH) and luteinizing hormone (LH) may play an important role in bone mass regulation in postmenopausal women.MethodsA cross-sectional study of 699 healthy Chinese women, aged 20 to 82 y, was conducted. Serum FSH and LH and BMD were measured at the posteroanterior (PA) spine, lateral spine, total hip, and distal forearm.ResultsThe geometric mean values (± SD) of serum FSH and LH in premenopausal women were 3.94 ± 2.08 and 7.51 ± 2.58 IU/l, respectively, and in postmenopausal women were 28.8 ± 1.88 and 25.6 ± 1.95 IU/l, respectively. The correlation of FSH to BMD at different skeletal regions (r = ? 0.597 – ? 0.492, P = 0.000) was higher than that of LH to BMD (r = ? 0.452 – ? 0.332, P = 0.000). The prevalences of osteoporosis for the quartiles of FSH at various skeletal sites were 0.57%, 0.43%, 27.1%, and 30.9%, respectively; and of LH were 2.14%, 4.43%, 19.5%, and 26.0%, respectively. The prevalence of osteoporosis in 3rd and 4th quartile was more significantly increased than the 1st and 2nd quartile.ConclusionsThese data suggest that FSH and LH levels in circulation are associated with BMD changes and osteoporosis occurrence in Chinese women.     

Effects of temperature and light on the stability of bilirubin in plasma samples

BackgroundAlthough it is known that bilirubin is photo-sensitive, detailed effects of both temperature and artificial light exposure on bilirubin stability in plasma have not been well investigated. We determined the impact of temperature and artificial light on bilirubin stability in plasma.MethodsPlasma total and direct bilirubin were analyzed using a diazo method. The aliquots of 38 samples were stored at 3 °C and 22 °C with light protection for 2, 4, 8, and 24 h respectively before analysis. The aliquots of 20 samples with normal bilirubin and additional 20 with elevated bilirubin were exposed to artificial light for 2, 4, 8, 24, and 48 h at 22 °C, and total and direct bilirubin were measured. The differences between the baselines and subsequent measurements were analyzed with analysis of variance.ResultsThe baseline total bilirubin was 9.6 ± 8.1 mg/dl (mean ± SD) and the concentrations were 9.6 ± 8.2, 9.0 ± 7.4, 9.0 ± 7.5, and 8.8 ± 7.5 mg/dl at 3 °C and 9.5 ± 8.1, 9.0 ± 7.4, 9.6 ± 8.1, and 9.5 ± 8.0 mg/dl at 22 °C after 2, 4, 8, and 24 h (p > 0.05, n = 38). The baseline direct bilirubin was 1.3 ± 1.2 mg/dl and the concentrations after 2, 4, 8, and 24 h were 1.4 ± 1.2, 1.4 ± 1.2, 1.5 ± 1.2, and 1.3 ± 1.1 mg/dl at 3 °C and 1.4 ± 1.1, 1.3 ± 1.1, 1.3 ± 1.1, and 1.3 ± 1.0 mg/dl at 22 °C (p > 0.05, n = 19). In samples with elevated bilirubin exposed to light at 22 °C, the baseline total and direct bilirubin concentrations were 10.2 ± 1.7 mg/dl and 5.0 ± 1.9 mg/dl, respectively. After 2, 4, 8, 24, and 48 h, total bilirubin concentrations were 10.1 ± 1.8, 10.0 ± 1.8, 10.0 ± 1.8, 9.3 ± 2.0 (p > 0.05, n = 20), and 8.4 ± 2.3 (p < 0.01, n = 20) mg/dl and direct bilirubin concentrations were 4.9 ± 1.8, 4.9 ± 1.9, 4.8 ± 1.8, 4.2 ± 1.6 (p > 0.05, n = 20), and 3.5 ± 1.5 (p < 0.01, n = 20) mg/dl. For samples with normal bilirubin levels under the same conditions, the average baseline total and direct bilirubin concentrations were 0.7 ± 0.1 mg/dl and below the lower limit of quantification (LLOQ), respectively. After 2, 4, 8, 24, and 48 h, the average total bilirubin concentrations were 0.7 ± 0.1, 0.6 ± 0.1, 0.6 ± 0.1 (p > 0.05, n = 20), 0.5 ± 0.1, and 0.4 ± 0.1 mg/dl (p < 0.01, n = 20) and direct bilirubin concentrations were still below LLOQ.ConclusionsBilirubin in plasma is stable in refrigerator or at room temperature without light exposure for at least 24 h. In normal laboratory environment, a delay of up to 8 h in the measurement of bilirubin left unprotected from light at room temperature does not significantly affect the results. Under these conditions, the changes in bilirubin concentration are not clinically significant until 24 h (direct bilirubin) and after 48 h (total bilirubin).     

Atrial natriuretic peptide stability

ObjectiveAtrial natriuretic peptide (ANP) is a key regulator in the homeostasis of water excretion and has emerged as an important prognostic marker for symptomatic chronic heart failure (CHF). The stability of ANP represents a crucial factor in assessing its use as a cardiac biomarker. Accordingly, we assessed the stability of ANP in blood samples collected from healthy controls and CHF subjects for a 12 month period.MethodsBlood samples from 10 healthy controls and 12 symptomatic CHF subjects with left ventricular systolic dysfunction were drawn. Determination of plasma ANP was performed by a standardized radioimmunoassay protocol.ResultsThe ANP levels of healthy subjects were 68.5 ± 11.6 pg/mL at baseline and 69.9 ± 17.2 pg/mL at 12 months (p = 0.71). The ANP concentrations of CHF subjects were 199.25 ± 44.8 pg/mL at baseline and 197.83 ± 47.4 pg/mL at 12 months (p = 0.70) respectively.ConclusionANP is a stable molecule with no evidence of degradation when stored at ? 80 °C.     

Serum pigment epithelium-derived factor levels are increased in patients with biopsy-proven nonalcoholic fatty liver disease and independently associated with liver steatosis

BackgroundIncreased serum concentrations of pigment epithelium-derived factor (PEDF) have been linked to the metabolic syndrome in the general population. However, the relationship between serum PEDF and nonalcoholic fatty liver disease (NAFLD), a hepatic manifestation of the metabolic syndrome, remains unknown.MethodsWe assayed serum PEDF levels in 156 patients with biopsy-proven NAFLD and 103 nonsteatotic control subjects who were matched for age and sex. The association between levels of PEDF and clinical, biochemical, and histological phenotypes was examined.ResultsNAFLD patients had significantly higher serum PEDF levels (1.97 ± 0.50 μg/mL) than control subjects (1.51 ± 0.49 μg/mL, Student's t test, P < 0.001). Multivariable-adjusted stepwise regression analysis showed that PEDF ([beta] = 0.32, t = 3.13, P = 0.002) and triglycerides ([beta] = 0.22, t = 2.23, P = 0.02) were, in the order they entered into the model, the main independent predictors of steatosis scores in our patients with NAFLD.ConclusionsSerum PEDF levels are significantly increased in patients with biopsy-proven NAFLD and are associated with liver steatosis independently of traditional risk factors.     

Accelerometer as a tool to assess sedentarity and adherence to physical activity recommendations after cardiac rehabilitation program

PurposeTo objectively assess, in stable cardiac patients, the adherence to physical activity (PA) recommendations using an accelerometer at 2 or 12 months after the discharge of cardiac rehabilitation program (CRP).MethodsEighty cardiac patients wore an accelerometer at 2 months (group 1, short-term adherence, n = 41) or one-year (group 2, long-term adherence, n = 39) after a CRP including therapeutic education about regular PA. PA was classified as “light” (1.8–2.9 Metabolic Equivalent of Task [METs]), “moderate” (3–5.9 METs), or “intense” (> 6 METs). Energy expenditure (EE, in Kcal) and time (min) spent in these three different levels were measured during a one-week period with the MyWellness Key actimeter (MWK). Motivational readiness for change was also assessed at the end of CRP. Patients were considered as physically active when a minimum of 150 min of moderate PA during the one-week period was achieved.ResultsBoth groups were comparable, except for exercise capacity at the end of the CRP which was slightly higher in group 1 (167.5 ± 42.3 versus 140.7 ± 46.1 W, P < 0.01). The total weekly active EE averaged 676.7 ± 353.2 kcal and 609.5 ± 433.5 kcal in group 1 and 2, respectively. The time spent within the light-intensity range PA was 319.4 ± 170.9 and 310.9 ± 160.6 min, and the time spent within the moderate-intensity range averaged 157.4 ± 115.4 and 165 ± 77.2 min per week for group 1 and 2, respectively. Fifty-three percent and 41% of patients remained active in both groups respectively.ConclusionAbout half of the patients are non-adherent to PA after CRP and do not reach target levels recommended by physicians. The first 2 months following the discharge of CRP seem to be of outmost importance for lifestyle modifications maintenance, and further study monitoring more closely PA decrease could help to clarify the optimal follow-up options.     

Persistent elevation of paraoxonase-1 specific enzyme activity after weight reduction in obese non-diabetic men with metabolic syndrome

BackgroundParaoxonase-1 (PON1) is an esterase associated with the high-density lipoprotein (HDL) in serum. To date, there have been few reports about circulating PON1 protein concentration and specific activity in subjects with metabolic syndrome (MetS). More importantly, it is unknown whether weight loss could alter PON1 protein expression or specific activity in obese non-diabetic men with MetS.MethodsWe prospectively enrolled a total of 40 obese non-diabetic men with MetS. Among them, 22 subjects finished the 3-month course of weight loss program and complied for longer follow-ups post-weight loss at the 3rd, 12th, and 18th month from the beginning of the program. Twenty-six healthy volunteers served as controls. Serum circulating PON1 concentration was measured by an enzyme linked immunosorbent kit (ELISA) and PON1 activity was measured by an automated PON1 activity assay.ResultsObese non-diabetic men with MetS (n = 40) had a higher PON1 protein concentration (31.0 ± 11.3 vs. 24.8 ± 9.7 μg/ml, p = 0.025) but lower specific enzyme activity (7.5 ± 4.0 vs. 11.2 ± 7.2 mU/μg, p = 0.023) than those of the controls. Multivariate regression analysis of baseline PON1 specific activity revealed that adiponectin was a significant positive predictor (p = 0.044) while monocyte chemotactic protein-1 (MCP-1) was a negative predictor (p = 0.031). After a 3-month weight loss program, obese MetS men (n = 22) had a significant weight reduction (95.8 ± 9.0 to 86.3 ± 10.4 kg, with a 9.9 ± 5.4% decrease, p < 0.001). PON1 protein decreased significantly after weight loss and kept declining through the 3rd month till the 18th month follow-up. PON1 specific enzyme activity (baseline 7.5 ± 2.6 mU/μg) increased significantly after weight loss and kept increasing through the 12th month till the 18th month follow-ups (11.8 ± 6.4 mU/μg, p = 0.001 vs. baseline).ConclusionsWeight loss by a 3-month diet and exercise program time-sequentially increased PON1 specific enzyme activity in obese non-diabetic men with MetS.     

Purification and properties of human serum carnosinase

Carnosinase from human plasma was purified 18,000-fold to apparent homogeneity in a four step procedure. The dipeptidase was partially inactivated during DEAE-cellulose chromatography; however, it reactivated slowly when concentrated and stored at 4 degrees C. In the second purification step, hydroxylapatite column chromatography, two forms of the enzyme were separated from one another. Human serum carnosinase was found to be a glycoprotein with a pI of 4.4 and a subunit Mr of 75,000; the active enzyme was a dimer, the two subunits being connected by one or more disulfide bonds. The enzyme was especially active in hydrolyzing carnosine and anserine, preferring dipeptides with histidine in the C-terminal position. In most human tissues, the concentration of serum carnosinase was proportional to the percentage of trapped blood in the sample. However, the brain contained about 9 times more enzyme than expected, based on the amount of trapped blood present. The physiological function of this enzyme seems to be the hydrolysis of homocarnosine in the brain and the splitting of carnosine and anserine in the blood stream. Six higher primates were found to have serum carnosinase. Twelve nonprimate mammals were tested; all were lacking the serum enzyme except for the Golden hamster, which had very high concentrations of a carnosinase having somewhat different properties than the higher primate enzyme.     

Association of haptoglobin phenotypes with ceruloplasmin ferroxidase activity in β-thalassemia major

BackgroundHaptoglobin (Hp) and ceruloplasmin (CP) are 2 plasma antioxidants playing a role in preventing iron-induced oxidative damage. This study presents data related to Hp phenotypes and ceruloplasmin ferroxidase activity in relation to iron store markers in patients with β-thalassemia major.MethodsBlood specimens were collected from 196 subjects (124 β-thalassemia major patients and 72 healthy controls). Serum levels of iron, total iron binding capacity (TIBC), ferritin, high sensitivity C-reactive protein (hs-CRP), ceruloplasmin, and ferroxidase activity were determined using conventional methods. Haptoglobin phenotypes were determined by polyacrylamide gel electrophoresis.ResultsAs expected, the mean levels of iron store markers, except TIBC, were significantly higher in patients than in controls. Ceruloplasmin concentrations (mg/dl) and its ferroxidase activity (U/l) were significantly higher in patients than in controls (57.9 ± 18.8 vs 46.9 ± 14.2 and 159.9 ± 47.8 vs 95.3 ± 20.9; p < 0.001, for CP and Hp, respectively). As for Hp phenotypes, no significant differences were observed between iron store markers and ferroxidase activity among the control group. In the patients group however, significantly higher concentrations of ceruloplasmin and its ferroxidase activity were observed among patients with Hp2-2 phenotype as compared to patients with the other phenotypes. Additionally, correlations according to Hp phenotypes revealed strong association between ceruloplasmin ferroxidase activity and serum ferritin in patients with Hp 2-2 phenotype and not in the others (r = 0.331, p < 0.05).ConclusionThalassemia patients with Hp 2-2 phenotype are under greater iron-driven oxidative stress than patients with other phenotypes.     

Increased serum levels of β₂-GPI-Lp(a) complexes and their association with premature atherosclerosis in patients with rheumatoid arthritis

BackgroundOur recent study found the existence of complexes of β₂-glycoprotein I (β₂-GPI) with lipoprotein(a)[Lp(a)] in circulation and the complex concentrations were increased in sera of systemic lupus erythematosus patients. The concentration of β₂-GPI-Lp(a) and its relationship with premature atherosclerosis were evaluated in rheumatoid arthritis (RA) patients.MethodsSerum concentrations of β₂-GPI-Lp(a) were measured in 53 active RA patients and 40 healthy controls by a “sandwich” ELISA. β₂-GPI-ox-LDL, ox-Lp(a), ox-LDL and anti-β₂-GPI were also measured by ELISAs. In addition, inflammatory markers were examined.ResultsSerum β₂-GPI-Lp(a) (1.12 ± 0.25 U/ml vs. 0.87 ± 0.19 U/ml, P < 0.0001) and β₂-GPI-ox-LDL (1.01 ± 0.20 U/ml vs. 0.80 ± 0.08 U/ml, P < 0.0001) concentrations in RA were both significantly higher than those of controls. Ox-Lp(a) (8.38 ± 6.69 mg/l vs. 5.49 ± 4.31 mg/l, P < 0.05) and ox-LDL (0.68 ± 0.65 mg/l vs. 0.37 ± 0.13 mg/l, P = 0.001) were also higher in RA than in controls. The area under the ROC curve (AUC) for β₂-GPI-Lp(a) (0.787) was larger than for ox-Lp(a) (0.731). AUC of β₂-GPI-ox-LDL (0.858) was also larger than for ox-LDL (0.785). β₂-GPI-Lp(a) and β₂-GPI-ox-LDL were positively correlated with ox-Lp(a), ox-LDL and CRP, respectively.Conclusionsβ₂-GPI-Lp(a) complex concentrations increased in active RA. Inflammation and oxidative stress in RA contribute to the increase of ox-Lp(a) and subsequently the formation of β₂-GPI-Lp(a).