Recommendations for the application and follow-up of quality controls in medical laboratories

This is a translation of the paper “Recommendations for the application and follow-up of quality controls in medical biology laboratories” published in French in the journal Annales de Biologie Clinique (Recommandations pour la mise en place et le suivi des contrôles de qualité dans les laboratoires de biologie médicale. Ann Biol Clin (Paris). 2019;77:577-97.). The recommendations proposed in this document are the result of work conducted jointly by the Network of Accredited Medical Laboratories (LABAC), the French Society of Medical Biology (SFBC) and the Federation of Associations for External Quality Assessment (FAEEQ). The different steps of the implementation of quality controls, based on a risk analysis, are described. The changes of reagent or internal quality control (IQC) materials batches, the action to be taken in case of non-conform IQC results, the choice of external quality assessment (EQA) scheme and interpretation of their results as well as the new issue of analyses performed on several automatic systems available in the same laboratory are discussed. Finally, the concept of measurement uncertainty, the robustness of the methods as well as the specificities of near-patient testing and rapid tests are described. These recommendations cannot apply for all cases we can find in medical laboratories. The implementation of an objective alternative strategy, supported with documented evidence, might be equally considered.

Icteric human samples: Icterus index and method of estimating an interference-free value for 16 biochemical analyses

BACKGROUND

Hemolysis, Icterus, and Lipemia constituting the HIL index, are the most common causes of interference with accurate measurement in biochemistry. This study focuses on bilirubin interference, aiming to identify the analyses impacted and proposing a way to predict nominal interference-free analyte concentrations, based on both analyte level and Icterus Index (I_ict ).

METHODS

Sixteen common analytes were studied: alanine aminotransferase (ALT), albumin (ALB), alkaline phosphatase (ALP), amylase (AMY), aspartate aminotransferase (AST), total cholesterol (CHOLT), creatinine (CREA, enzymatic method), fructosamine (FRUC), gamma-glutamyl transferase (GGT), HDL cholesterol (HDLc), total iron (Iron), lipase (LIP), inorganic phosphorus (Phos), total protein (PROT), triglycerides (TG), and uric acid (UA). Both the traditional 10% change in concentrations from baseline and the Total Change Level (TCL) were taken as acceptance limits. Nineteen pools of sera covering a wide range of values were tested on the Cobas® 6000 (Roche Diagnostics). I_ict ranged from 0 to 60.

RESULTS

Eight analytes increased (FRUC and Phos) or decreased (CHOLT, CREA, HDLc, PROT, TG, and UA) significantly when I_ict increased. FRUC, HDLc, PROT, and UA showed a linear relationship when I_ict increased. A non-linear relationship was found for TG, CREA, and for CHOLT; this also depended on analyte levels. Others were not impacted, even at high I_ict .

CONCLUSIONS

A method of estimating an interference-free value for FRUC, HDLc, PROT, Phos, UA, TG, and CREA, and for CHOLT in cases of cholestasis, is proposed. I_ict levels are identified based on analytical performance goals, and equations to recalculate interference-free values are also proposed.

A Combination of Single-Nucleotide Polymorphisms Is Associated with Interindividual Variability in Cholecalciferol Bioavailability in Healthy Men

BACKGROUND

Most people require dietary vitamin D to achieve the recommended concentration of 25-hydroxyvitamin D [25(OH)D] in the blood. However, the response to vitamin D supplementation is highly variable among individuals.

OBJECTIVE

We assessed whether the variability in cholecalciferol bioavailability was associated with single-nucleotide polymorphisms (SNPs) in candidate genes.

METHODS

In a single-group design, 39 healthy adult men with a mean ± SD age of 33 ± 2 y and mean ± SD body mass index (in kg/m²) of 22.9 ± 0.3 were genotyped with the use of whole-genome microarrays. After an overnight fast, plasma 25(OH)D status was measured, and the subjects then consumed a meal that provided 5 mg cholecalciferol as a supplement. Plasma chylomicron cholecalciferol concentration was measured over 8 h, and cholecalciferol response was assessed by calculating the postprandial area under the curve. Partial least squares regression was used to test the association of SNPs in or near candidate genes (61 genes representing 3791 SNPs) with the postprandial cholecalciferol response.

RESULTS

The postprandial chylomicron cholecalciferol concentration peaked at 5.4 h. The cholecalciferol response was extremely variable among individuals (CV: 47%). It correlated with the chylomicron triglyceride (TG) response (r = 0.60; P < 0.001) but not with the fasting plasma 25(OH)D concentration (r = 0.04; P = 0.83). A significant (P = 1.32 × 10^-4) partial least squares regression model that included 17 SNPs in 13 genes (including 5 that have been associated with chylomicron TG response) was associated with the variance in the cholecalciferol response.

CONCLUSION

In healthy men, there is a high interindividual variability in cholecalciferol bioavailability that is associated with a combination of SNPs located in or near genes involved in both vitamin D and lipid metabolism. This trial was registered at clinicaltrials.gov as NCT02100774.

A chronicle of the changes undergone by a maritime territory, the Bay of Toulon (Var Coast, France), and their consequences on PCB contamination

This study evaluated the distribution of polychlorinated biphenyls (PCBs) in 39 surface sediment samples and four cores collected in Toulon Bay, a semiclosed area submitted to various anthropogenic inputs. The concentration of PCBs in the superficial sediment samples ranged from 1.7 to 2530 ng g⁻¹ dry weight. The spatial distribution of these compounds suggested that the high concentrations of these contaminants are located in the small bay and are related to human activities. In the larger bay, the concentrations were in the same order of magnitude than those reported in others locations around the world. Comparison of the levels with target values from the French legislation shows that, except for four polluted sites with critical values (N2: values ≥1 mg kg⁻¹ dry weight) in the smaller bay, PCBs levels throughout the larger and the smaller bay are lower than the accepted values (N1: values <0.5 mg kg⁻¹ dry weight). The PCBs in the sediment cores ranged from 0.8 to 739 ng g⁻¹ dry weight dependent core. Vertical profiles indicated earlier usage of PCBs which coincided with the history of the Toulon Bay. In this study, using alkane, we could follow the PCBs pollution history over about 80 years and estimate a sedimentation rate of about 0.32 cm year in the small Bay of Toulon.

The Transcriptional Effects of PCB118 and PCB153 on the Liver, Adipose Tissue, Muscle and Colon of Mice: Highlighting of Glut4 and Lipin1 as Main Target Genes for PCB Induced Metabolic Disorders

Epidemiological studies have associated environmental exposure to polychlorinated biphenyls (PCBs) with an increased risk of type 2 diabetes; however, little is known about the underlying mechanisms involved in the metabolic side-effects of PCB. Our study evaluated the transcriptional effects of a subchronic exposure (gavage at Day 0 and Day 15 with 10 or 100 μmol/Kg bw) to PCB118 (dioxin-like PCB), PCB153 (non-dioxin-like PCB), or an equimolar mixture of PCB118 and PCB153 on various tissues (liver, visceral adipose tissue, muscle, and colon) in mice. Our results showed that a short-term exposure to PCB118 and/or PCB153 enhanced circulating triglyceride levels but did not affect glycemia. Among the studied tissues, we did not observe any modification of the expression of inflammation-related genes, such as cytokines or chemokines. The main transcriptional effects were observed in visceral adipose and liver tissues. We found a downregulation of lipin1 and glut4 expression in these two target organs. In adipose tissue, we also showed a downregulation of Agpat2, Slc25a1, and Fasn. All of these genes are involved in lipid metabolism and insulin resistance. In muscles, we observed an induction of CnR1 and Foxo3 expression, which may be partly involved in PCB metabolic effects. In summary, our results suggest that lipin1 and glut4, notably in adipose tissue, are the main targeted genes in PCB-induced metabolic disorders, however, further studies are required to fully elucidate the mechanisms involved.

Methylmercury and Trace Element Distribution in the Organs of Stenella coeruleoalba Dolphins Stranded on the French Mediterranean Coast

The main objective of this study was to evaluate the contamination by mercury (Hg), methylmercury (Me-Hg), cadmium (Cd), selenium (Se), zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) in dolphins stranded on the French Mediterranean coast.

The distributions of these contaminants in the organs of dolphins have also been studied. Overall, contamination levels varied according to the following sequence: liver > kidney > lung > muscle, except for cadmium (kidney > liver > lung > muscle).

Size and sex of animals were also considered. Young dolphins were less impacted with trace elements than adults, except for copper. Among the studied parameters, the most important appeared to be the size of mammals. In addition, in the case of mercury and selenium, the sex of mammals seemed to be also relevant.

The correlations between the concentrations of trace elements suggest the existence of detoxification processes.

Since 1990s, using dolphins for tracing marine pollution, a slight reduction in the burden of the considered trace elements could be noted.

Influence of diet and sample collection time on 77 laboratory tests on healthy adults

OBJECTIVES

We studied the effect of a standardized breakfast or lunch before blood sampling on 77 analytes.

DESIGN AND METHODS

The mean difference between assays from 20 healthy adults was calculated on blood samples taken before and after food intake. Significant differences were tested using two-tailed Student t-test and compared to the acceptable limits derived from analytical and intraindividual biological variation.

RESULTS

Most of the analytes investigated were not significantly affected by food intake. Six of them were influenced by breakfast or lunch: triglycerides, glucose, creatinine, C-peptide and insulin were significantly upregulated, whereas testosterone was downregulated. Fourteen parameters were more influenced by time of sampling than by meals: nine decreased during the day (total bilirubin, BNP, myoglobin, cortisol, TSH, C-telopeptide, prolactin, ACTH, uric acid) and two increased (white blood cells, neutrophils). Three parameters showed levels that were similar at 9:00 am and 5:00 pm but their lowest level at 12:30 pm (inorganic phosphorus, osteocalcin, PTH).

CONCLUSIONS

Fasting is necessary for some laboratory tests. Clinicians should be aware of variations due to sampling time before ordering non-fasting tests, and in the subsequent interpretation of results.

PCBs and DDTs in Stenella coeruleoalba dolphins from the French Mediterranean coastal environment (2007-2009): current state of contamination

Organochlorinated compounds including PolyChloroBiphenyles, Dichloro-DiphenylTrichloroethan and metabolites are determinated in Stenella coeruleoalba (n = 37) stranded on the french Mediterranean coasts from 2007 till 2009. Studies are carried out on lung, muscle, kidney, liver, and blubber. The sought-after compounds are all detected to variable levels in each tissue and organ. In general, total PCBs are the most abundant, followed by total DDTs. The concentration (in ng g(-1) of lipid weight) in blubber of S. coeruleoalba, varied from 2,052 to 158,992 for PCBs and from 1,120 to 45,779 for DDTs. The ratios DDE/tDDTs are higher than 80% in almost all samples. The overall results of this work, compared to previous studies concerning the Mediterranean Sea, seems to confirm the tendency to a decrease of the contamination by organics compounds for the cetaceans in the Western Mediterranean Sea.

Unacylated Ghrelin is associated with the isolated low HDL-cholesterol obese phenotype independently of insulin resistance and CRP level

BACKGROUND

Low plasma high-density lipoprotein-cholesterol (HDL-c) level is commonly present in obesity and represents an independent cardiovascular risk factor. However, obese patients are a very heterogeneous population and the factors and mechanisms that contribute to low HDL-c remain unclear. The aim of this study was to investigate the association between plasma HDL-c levels and plasma hormonal profiles (insulin, adiponectin, resistin, leptin and ghrelin) in subsets of class II and III obese patients.

METHODS

Fasting plasma levels of glucose, total cholesterol, LDL-c, HDL-c, triglycerides, free fatty acids, apoproteins A-I, B-100, B-48, C-II, C-III, insulin, hs-CRP, adipocytokines (adiponectin, resistin, leptin), unacylated ghrelin, body composition (DXA) and resting energy expenditure were measured in three subsets of obese patients: 17 metabolically abnormal obese (MAO) with metabolic syndrome and the typical metabolic dyslipidaemia, 21 metabolically healthy obese (MHO) without metabolic syndrome and with a normal lipid profile, and 21 isolated low HDL-c obese patients (LHO) without metabolic syndrome, compared to 21 healthy lean control subjects.

RESULTS

Insulin resistance (HOMA-IR) increased gradually from MHO to LHO and from LHO to MAO patients (p < 0.05 between MHO and MAO and between LHO and MAO). In multiple regression analysis, serum unacylated ghrelin levels were only positively and independently associated with HDL-c levels in the LHO group (p = 0.032).

CONCLUSIONS

These results suggest that, in class II and III obese patients with an isolated low HDL-c phenotype, unacylated ghrelin is positively associated with HDL-c level independently of insulin resistance and CRP levels, and may contribute to the highly prevalent low HDL-c level seen in obesity.

Stability study of 81 analytes in human whole blood, in serum and in plasma

OBJECTIVE

We studied the pre-analytical stability of 81 analytes based on the variables of delay before processing, storage as whole blood or serum/plasma, the storage temperature and the type of tube the sample was stored in.

DESIGN AND METHODS

The mean difference between assays for samples from 10 subjects was calculated with the samples being kept under different storage conditions and for different times between sampling time and analysis: up to 24h for biochemistry, coagulation and hematology, and up to 72 h for hormonology. This difference was compared to the acceptable limits derived from the analytical and the intra individual biological variation.

RESULTS

Most of the analytes investigated remained stable up to 24h under all storage conditions prior to centrifugation. However, some analytes were significantly affected either by delay, tube type or temperature, such as potassium, inorganic phosphorus, magnesium, LD, glucose, lactate, mean corpuscular volume, mean corpuscular hemoglobin, activated partial thromboplastin time, insulin, C-peptide, PTH, osteocalcin, C-telopeptide and ACTH.

CONCLUSION

This study may be useful to help define acceptable delay times and storage conditions when a short time between sample collection and processing is not possible.

Cholesterol-absorber status modifies the LDL cholesterol-lowering effect of a Mediterranean-type diet in adults with moderate cardiovascular risk factors

LDL-cholesterol (LDL-C) reduction may be achieved by various types of prudent diets, but their effects on surrogate markers of cholesterol absorption and synthesis have not been well studied in humans. We aimed to assess whether the extent of cholesterol absorption or synthesis, and cholesterol concentrations, are modified in adults when they shift from a Western-type diet (WD) to a combined low-fat, low-cholesterol/Mediterranean-type diet (LFCMD). Cholestanol and sitosterol, as well as desmosterol and lathosterol, surrogate markers of cholesterol absorption or synthesis, respectively, were quantified in the serum of 125 fasting, middle-aged participants at moderate cardiovascular risk. They habitually consumed a WD and then consumed a LFCMD during the 3-mo intervention. The group was stratified by serum cholestanol concentration and classified as high, intermediate, or low absorbers of cholesterol. When they consumed the WD, participants had comparable total and LDL-C concentrations, independent of absorber group and sex. After 3 mo of consuming the LFCMD, absorption and synthesis did not change or changed only slightly. The cholestanol concentration increased in low absorbers by 18% (P < 0.02) and decreased in high absorbers by 14% (P < 0.001), but these variations did not change the high- or low-absorber status. In male and female low absorbers, plasma total (-7%) and LDL-C (-9%) concentrations decreased after the 3-mo intervention and changes were 2.3- and 2.4-fold greater, respectively, than in high absorbers, independent of sex. Cholesterol synthesis/absorption status was not markedly altered by diet, but the decrease in plasma LDL-C due to the Mediterranean-type diet occurred only in low absorbers of cholesterol. This should be considered during further dietary interventions.

Cholesterol absorption status and fasting plasma cholesterol are modulated by the microsomal triacylglycerol transfer protein -493 G/T polymorphism and the usual diet in women

An important inter-individual variability in cholesterol absorption has been reported. It could result from polymorphisms in genes coding for proteins involved in the absorption process and in interaction with dietary intakes. To assess whether the extent of cholesterol absorption or synthesis is modified in adult women according to the -493 G/T polymorphism in the microsomal triglyceride transfer protein gene (MTP) and/or the habitual diet. Cholestanol and sitosterol, as well as desmosterol and lathosterol, surrogate markers of cholesterol absorption or synthesis, respectively, were analyzed in the fasting plasma of 69 middle-aged women under a Western-type diet (WD) and after 3 months on a low-saturated fat, low-cholesterol/Mediterranean-type diet (LFLCD). Genotypes for MTP -493G/T polymorphism were determined. Under an usual WD, subjects homozygous for the MTP -493 T allele exhibited higher (P < 0.05) fasting serum concentrations of cholestanol (199.0 ± 30.0 vs. 133 ± 7.4 × 10(2 )mmol/mol cholesterol) and lathosterol (188.7 ± 21.8 vs. 147.6 ± 9.1 × 10(2) mmol/mol cholesterol), as well as total cholesterol (7.32 ± 0.22 vs. 6.63 ± 0.12 mmol/l) compared to G carrier subjects. After 3 months on a LFLCD, level of absorption markers decreased in TT subjects with no change in synthesis ones, leading to values comparable to those measured in G carriers. The lowering of plasma total and LDL cholesterol due to dietary change was 2.4- and 2.3-fold greater in TT women than in G carriers. The polymorphism -493G/T in MTP modulates the level of cholesterol absorption but not synthesis in women under a WD, an effect abolished under a prudent LFLCD.

Additive effect of polymorphisms in the IL-6, LTA, and TNF-{alpha} genes and plasma fatty acid level modulate risk for the metabolic syndrome and its components

CONTEXT

Cytokine polymorphisms and dietary fat composition may influence the risk of the metabolic syndrome (MetS).

OBJECTIVE

The objective of the study was to determine the relationship between lymphotoxin-alpha (LTA), TNF-alpha, and IL-6 gene polymorphisms with MetS risk and investigate whether plasma fatty acid composition, a biomarker of dietary fat intake, modulated these associations.

DESIGN

Polymorphisms (LTA rs915654, TNF-alpha rs1800629, IL-6 rs1800797), biochemical measurements, and plasma fatty acids were determined in the LIPGENE-SU.VI.MAX study of MetS cases and matched controls (n = 1754).

RESULTS

LTA rs915654 minor A allele carriers and TNF-alpha rs1800629 major G allele homozygotes had increased MetS risk [odds ratio (OR) 1.37 (confidence interval [CI] 1.12-1.66), P = 0.002 and OR 1.35 (CI 1.08-1.70), P = 0.009] compared with their TT homozygotes and A allele carriers. Possession of the IL-6 rs1800797 GG genotype by the LTA and TNF-alpha risk genotype carriers further increased risk of the MetS [OR 2.10 (CI 1.19-3.71) P = 0.009], fasting hyperglycemia [OR 2.65 (CI 1.12-6.28), P = 0.027], high systolic blood pressure [OR 1.99 (CI 1.07-3.72), P = 0.03], and abdominal obesity [OR 1.52 (CI 1.01-2.28), P = 0.04]. Plasma polyunsaturated to saturated fat ratio exacerbated these effects; subjects in the lowest 50th percentile had even greater risk of the MetS [OR 4.40 (CI 1.55-12.45), P = 0.005], fasting hyperglycemia, high systolic blood pressure, and abdominal obesity (P < 0.05).

CONCLUSIONS

LTA, TNF-alpha, and IL-6 genotype interactions increased MetS risk, which was further exacerbated by a low plasma polyunsaturated to saturated fat exposure, indicating important modulation of genetic risk by dietary fat exposure.

Complement component 3 polymorphisms interact with polyunsaturated fatty acids to modulate risk of metabolic syndrome

BACKGROUND

Complement component 3 (C3) is a novel determinant of the metabolic syndrome (MetS). Gene-nutrient interactions with dietary fat may affect MetS risk.

OBJECTIVES

The objectives were to determine the relation between C3 polymorphisms and MetS and whether interaction with plasma polyunsaturated fatty acids (PUFAs), a biomarker of dietary PUFA, modulate this relation.

DESIGN

C3 polymorphisms (rs11569562, rs2250656, rs1047286, rs2230199, rs8107911, rs344548, rs344550, rs2241393, rs7257062, rs163913, and rs2230204), biochemical measurements, and plasma fatty acids were measured in the LIPGENE-SUpplementation en VItamines et Minéraux AntioXydants (SU.VI.MAX) study in MetS cases and matched controls (n = 1754).

RESULTS

Two single nucleotide polymorphisms were associated with MetS. rs11569562 GG homozygotes had decreased MetS risk compared with minor A allele carriers [odds ratio (OR): 0.53; 95% CI: 0.35, 0.82; P = 0.009], which was augmented by high plasma PUFA status (OR: 0.32; 95% CI: 0.11, 0.93; P = 0.04). GG homozygotes had lower C3 concentrations than those in AA homozygotes (P = 0.03) and decreased risk of hypertriglyceridemia compared with A allele carriers (OR: 0.54; 95% CI: 0.34, 0.92; P = 0.02), which was further ameliorated by an increase in long-chain n-3 (omega-3) PUFAs (OR: 0.46; 95% CI: 0.22, 0.97; P = 0.04) or a decrease in n-6 PUFAs (OR: 0.32; CI: 0.16, 0.62; P = 0.002). rs2250656 AA homozygotes had increased MetS risk relative to minor G allele carriers (OR: 1.78; CI: 1.19, 2.70; P = 0.02), which was exacerbated by low n-6 PUFA status (OR: 2.20; CI: 1.09, 4.55; P = 0.03).

CONCLUSION

Plasma PUFAs may modulate the susceptibility to MetS that is conferred by C3 polymorphisms, which suggests novel gene-nutrient interactions. This trial was registered at clinicaltrials.gov as NCT00272428.

Parallel increase of plasma apoproteins C-II and C-III in Type 2 diabetic patients

AIMS

To determine plasma levels of apoprotein (apo) C-II and apoprotein C-III in Type 2 diabetic patients and to examine the clinical and biological factors that are associated with elevated apoC concentrations.

METHODS

We measured apoC-II and apoC-III in total plasma and in non-high-density lipoprotein fractions by an immunoturbidimetric assay in 88 Caucasian Type 2 diabetic patients and in 138 healthy control subjects.

RESULTS

Plasma levels of both apoC-II and apoC-III were increased in Type 2 diabetic patients. The clinical conditions associated with an increase of plasma apoC-II and apoC-III were abdominal obesity, body mass index, poor glycaemic control and lack of insulin treatment. However, when multivariate analysis was used, plasma apoCs levels correlated with triglyceride levels only. The apoC-III/apoC-II ratio was similar in the Type 2 diabetic and control subjects.

CONCLUSIONS

Our study shows the parallel increase of apoC-II and C-III in Type 2 diabetic patients. This parallel increase is related to hypertriglyceridaemia only.

Pharmacodynamics of unfractionated heparin during and after a hemodialysis session

BACKGROUND

Anti-Xa activity is used as a clinical guide to anticoagulation with heparin, but heparin dosing regimens for hemodialysis were established before anti-Xa assays were developed; thus, the optimal regimen for heparin dosing was not determined. The aim is to confirm the interesting characteristics of unfractionated heparin pharmacokinetics for hemodialysis anticoagulation, provide insight into the hemorrhagic risk of hemodialysis patients, and determine the dose of unfractionated heparin and its adequate mode of administration.

STUDY DESIGN

Cross-sectional study of the pharmacokinetics of unfractionated heparin performed during and after a 4-hour midweek hemodialysis session.

SETTING & PARTICIPANTS

35 long-term hemodialysis patients at the Sainte-Marguerite Unit of the Marseille University Hospital, Marseille, France.

PREDICTOR

Hemodialysis anticoagulation with continuous unfractionated heparin infusion at a dose of 50 IU/kg/session (25 IU/kg/h during the first hour, 12.5 IU/kg during the second and third hours, and stop during the last hour).

OUTCOME & MEASUREMENTS

Anti-Xa activity was monitored during the 10 hours after the beginning of the hemodialysis session. Levels of 0.3 to 0.7 IU/mL are considered sufficient for anticoagulation. Pharmacokinetics was determined by using a population approach (nonlinear mixed-effects modeling). The final model and corresponding parameter values (including interindividual and residual variability) were used to simulate 1,000 replicates.

RESULTS

No case of clotting was recorded. A pharmacokinetic model with 1 compartment and first-order elimination best fitted the data. Terminal half-life was 54 minutes. Median anti-Xa activities were 0.55 IU/mL at peak, 0.25 IU/mL at end of the 4-hour session, and less than 0.1 IU/mL at 90 minutes after the session. We simulated a continuous infusion of the dose of 50 IU/kg for 1, 2, 3, and 4 hours. Peak values were 1.1, 0.8, 0.6, and 0.5 IU/mL, respectively. Values at the end of the session were 0.12, 0.18, 0.3, and 0.5 IU/mL, respectively. Values became less than 0.1 IU/mL at 15, 60, 105, and 120 minutes after the session, respectively.

LIMITATIONS

Interindividual variability in unfractionated heparin pharmacokinetics.

CONCLUSIONS

Unfractionated heparin administered by means of a 3-hour continuous infusion for hemodialysis anticoagulation provided an efficient and safe effect that quickly disappeared after the end of the session.

Human plasma levels of vitamin E and carotenoids are associated with genetic polymorphisms in genes involved in lipid metabolism

Vitamin E and carotenoids are fat-soluble micronutrients carried by plasma lipoproteins. Their plasma concentrations are governed by several factors, some of which are genetic, but data on these genetic factors remain scarce. We hypothesized that genes involved in lipid metabolism, i.e. the genes implicated in intestinal uptake, intracellular trafficking, and the lipoprotein distribution of lipids, play a role in the plasma concentrations of these micronutrients. To verify this hypothesis, we assessed whether the plasma status of vitamin E and carotenoids is related to genes involved in lipid metabolism. Fasting plasma vitamin E (alpha- and gamma-tocopherol) and carotenoid (alpha- and beta-carotene, lutein, lycopene, beta-cryptoxanthin, and zeaxanthin) concentrations were measured in 48 males and 80 females. The following genes were genotyped [single nucleotide polymorphisms (SNP)]: apolipoprotein (apo) A-IV, apo B, apo E, lipoprotein lipase, and scavenger-receptor class B type I (SR-BI). Plasma alpha-tocopherol concentrations were different (P < 0.05) in subjects bearing different SNP in apo A-IV, apo E, and SR-BI. Plasma gamma-tocopherol concentrations were different (P < 0.05) in subjects bearing different SNP in apo A-IV and SR-BI. Alpha-carotene concentrations were different (P < 0.05) in subjects bearing different SNP in SR-BI. Beta-carotene concentrations were different (P < 0.05) in subjects bearing different SNP in apo B and SR-BI. Lycopene concentrations were different (P < 0.05) in subjects bearing different SNP in apo A-IV and apo B. Beta-cryptoxanthin concentrations were different (P < 0.05) in subjects bearing different SNP in SR-BI. Plasma lutein and zeaxanthin concentrations did not differ in subjects bearing different SNP. Most of the differences remained significant after the plasma micronutrients were adjusted for plasma triglycerides and cholesterol. These results suggest that genes involved in lipid metabolism influence the plasma concentrations of these fat-soluble micronutrients.

Sex-specific association of fatty acid binding protein 2 and microsomal triacylglycerol transfer protein variants with response to dietary lipid changes in the 3-mo Medi-RIVAGE primary intervention study

BACKGROUND

The dietary guidelines targeted at reducing cardiovascular risk lead to largely heterogeneous responses in which genetic determinants are largely involved.

OBJECTIVES

We evaluated the effect of fatty acid binding protein 2 (FABP2) Ala54Thr and microsomal triacylglycerol transfer protein (MTTP) -493G/T allelic variations on plasma lipid markers, at baseline and on the response to the 3-mo Medi-RIVAGE primary prevention study.

DESIGN

Subjects with moderate cardiovascular disease risk (n = 169) were advised to reduce total and saturated dietary fats and to increase intake of monounsaturated and polyunsaturated fats. They were genotyped for FABP2 Ala54Thr and MTTP -493G/T allelic variations, and plasma was processed for cardiovascular risk marker analyses.

RESULTS

At baseline, men and women homozygous for Thr54 presented a significant opposite profile for plasma oleic acid (18:1), triacylglycerol-rich lipoprotein (TRL) cholesterol, and TRL phospholipids. In addition, all Thr/Thr men presented higher 18:1 values than did women. For the MTTP -493G/T polymorphism, although all TT subjects presented high apolipoprotein B-48, a genotype x sex interaction was present for palmitic acid, linolenic acid, eicosatrienoic acid, and insulin. The prudent diet clearly improved plasma lipid markers. FABP2 genotype did not interact much with the amplitude of the response. However, for MTTP polymorphism, men homozygous for the T allele displayed a significantly more pronounced response than did men carrying the G allele, which is particularly evident by their larger decrease in the Framingham score.

CONCLUSIONS

These 2 polymorphic loci are thus differently associated with the baseline lipid markers as well as with the response to nutritional recommendations, but both presented a marked sex-specific profile, with the response to diet being particularly efficient in men homozygous for the MTTP -493T allele.

Influence of parathyroidectomy on mortality in hemodialysis patients: a prospective observational study

BACKGROUND

In hemodialysis patients, the relationships between serum PTH and phosphorus levels and mortality are debated because both high and low turnover bone diseases increase the risk of vascular calcifications. Furthermore, the prevalence of hypoparathyroidism is increasing, and there is a fear that this state is associated with an increase in bone fractures.

METHODS

We performed a cross-sectional study to determine the prevalence and the causes of hypoparathyroidism (defined as basal and post-hypocalcemic-challenge serum PTH levels < 55 pg/mL) in 97 patients undergoing chronic hemodialysis treatment in our unit. We then prospectively observed patients with low PTH levels (< 55 pg/mL, n = 26) and those with hyperparathyroidism defined as a PTH levels > 200 pg/mL (n = 25) during eight years for all causes of mortality and bone fractures. Kaplan-Meyer survival curves were adjusted for age and sex.

RESULTS

Hypoparathyroidism was present in 30% of our patients. The main causes of hypoparathyroidism were parathyroidectomy (77%) and aluminium and iron overload. Survival did not differ between patients with hypoparathyroidism and hyperparathyroidism and between patients with serum phosphorus < or > 2 mmol/L. Parathyroidectomy was associated with better survival (p < 0.01). Similarly, incidence of bone fractures did not differ for the two groups.

CONCLUSIONS

Parathyroidectomy is the main cause of hypoparathyroidism in hemodialysis patients and is associated with a lower mortality risk. This result suggests that a more aggressive treatment of secondary hyperparathyroidism could decrease mortality in this high-risk population.

Cardiac troponins I and T in hemodialysis patients without acute coronary syndrome

BACKGROUND

There is a reluctance to use cardiac troponins (cTn) for the monitoring of acute coronary syndrome (ACS) in hemodialysis (HD) patients because renal failure per se is thought to lead to increased cTn levels. The aim of this study was to analyse the proportion of patients with increased cTn levels in HD patients without ACS.

METHODS

cTnI was measured with the AccuTnI(trade mark) from Beckman (cTnI-B) and Troponin I Stat(trade mark) from Dade Behring (cTnI-DB) assays; cTnT was measured with the third generation assay from Roche. The study included 105 HD patients. The clinical outcomes were determined after 2.5 years.

RESULTS

Considering the receiver operator characteristic (ROC) cutoff, the proportion of patients with elevated cTnI-B, cTnI-DB and cTnT levels was respectively 2%, 3% and 27%. The proportion of patients with abnormal cTn values increased when a lower cutoff value was considered, based on the 99th percentile of a reference population with a coefficient of variation of less than 10% (99th percentile-10% CV cutoff). The proportion of patients with elevated values did not differ before and after the HD session. The 2.5 years mortality was associated with increased levels of cTnT but not with increased levels of cTnI.

CONCLUSIONS

When the ROC cutoff is applied, cTnI assays are suitable for the monitoring of ACS in HD patients. cTnT could lead to false positive diagnosis of myocardial infarction, however it is predictive of long-term mortality. The 99th percentile-10% CV cutoff does not seem appropriate in HD patients.

Intradialytic parenteral nutrition: comparison of olive oil versus soybean oilbasedlipid emulsions

Lipid, oxidative and inflammatory parameters are frequently altered in dialysis patients and may be worsened by intravenous lipid emulsions (ILE). We assessed the efficacy and tolerance of olive as compared with standard soybean oil-based ILE during intradialytic parenteral nutrition (IDPN). IDPN mixtures containing amino acids, glucose, and either olive oil (OO group,n17) or soybean oil-based ILE (SO group,n18) were administered in a 5-week randomized, double-blind study. On days 0 and 35, patients' nutritional status was assessed by BMI, normalized protein catabolic rate, predialytic creatinine, serum albumin and transthyretin; lipid metabolism by plasma LDL- and HDL-cholesterol, triacylglycerols, phospholipids, apo A-I, A-II, B, C-II, C-III, E and lipoprotein (a); oxidative status by α-tocopherol, retinol, selenium, glutathione peroxidase, malondialdehyde and advanced oxidized protein products; inflammatory status by serum C-reactive protein, orosomucoid, IL-2 and IL-6. No serious adverse event was observed. Significant changes were observed from day 0 to day 35 (P<0·05): nutritional criteria improved (albumin in OO; albumin, transthyretin and creatinine in SO); LDL-cholesterol, apo B, C-II, C-III and apo A-I/A-II ratio increased in both groups. HDL-cholesterol decreased in OO; apo E increased and lipoprotein (a) decreased in SO; α-tocopherol/cholesterol ratio increased in OO; malondialdehyde decreased in both groups; IL-2 increased in both groups. The between-group comparison only showed the following differences: α-tocopherol/cholesterol increased in OO; lipoprotein (a) decreased in SO. From these data, it was concluded that OO- and SO-based IDPNs similarly improved nutritional status and influenced plasma lipid, oxidative, inflammatory and immune parameters.

A new approach to overcome natural cholesterol interference during simultaneous determination of two stable isotope-enriched cholesterol tracers in human plasma

We have developed a validated gas chromatography/mass spectrometry (GC/MS) method with two labelled cholesterol tracers, i.e. (2)H(4) ([2H4]-Chol) and (2)H(7) ([2H7]-Chol) enriched moieties, with a new way of calculating the abundance of labelled cholesterol in plasma without natural cholesterol interference. The isotopomers of the analytes could interfere during analysis. Elimination of these interferences can be performed by the blank or mathematical subtraction method. Validation was performed with the two interference elimination methods. For both methods, linearity was obtained in the range 5 x 10(-4) to 10(-2) mM for both labelled cholesterol moieties. In the same range, repeatability and reproducibility were less than 6.5% and 7.5% for [2H4]-Chol and [2H7]-Chol, respectively. Accuracy was about 100% and recoveries always included 100% for the two labelled cholesterols. We demonstrate that measurement of blank plasma is not necessary when using the validated abundance isotope calculation method. This saves time, reagent and samples. This calculation strategy can be extrapolated to comparable tracer approaches.

Potentiation of antifungal activity of amphotericin B by essential oil from Cinnamomum cassia

The antifungal activity of the essential oil from Cinnamomum cassia, alone or combined with amphotericin B, a drug widely used for most indications despite side-effects was investigated. The composition of the oil was analysed by GC/MS and characterized by its very high content of cinnamaldehyde (92.2%). The minimal inhibitory concentration (MIC 80%), used to evaluate the antifungal activity against Candida albicans, was determined by a macrobroth dilution method followed by a modelling of fungal growth. The essential oil of Cinnamomum cassia exhibited strong antifungal effect (MIC 80% = 0.169 microL/mL and K(aff) = 18,544 microL/mL). A decrease of the MIC 80% of amphotericin B was obtained when the culture medium contained essential oil concentrations ranging from 0.08 to 0.1 microL/mL. The strongest decrease (70%) was obtained when the medium contained 0.1 microL/mL of essential oil. This potentiation of amphotericin B obtained in vitro may show promise for the development of less toxic and more effective therapies especially for the treatment of HIV infection.

Concomitant cell growth and differentiation are dependent on erbB1 and integrin activation in an autonomously surviving colon adenocarcinoma: involvement of autocrine amphiregulin secretion

In normal colon epithelium, cell proliferation is followed by cell differentiation. The purpose of this work was to investigate, in the HT29-D4 colon adenocarcinoma cell line, the occurrence of a temporal sequence of changes in cell proliferation and differentiation, the role of autocrine EGF family ligands and to determine which transduction pathway(s) are involved in these processes. In a medium lacking both growth factor and serum, HT29-D4 cells secreted amphiregulin (AR), which was shown to be strongly involved in cell adhesion, growth and differentiation. In the main, integrins alpha2beta1 and alphavbeta6 intervened in these processes. Using tyrphostins, it was demonstrated that AR involvement was mediated through the ErbB1/ERK1,2 and ErbB1/FAK pathways. These signalling molecules were directly involved in pRb inhibition and, thus, in cyclin A expression. Concomitantly, colon differentiation markers were also expressed. Furthermore, terminal cell maturation resulted in a colon absorptive cell with strong polarisation, the growth of which was inhibited by tyrphostin and an ERK1,2 inhibitor. It was concluded that in a colon adenocarcinoma, cell proliferation and differentiation can occur concomitantly and that these deregulated processes are controlled by autocrine secretion through the ErbB1/ERK1,2 and FAK pathways.

Lack of toxicity of hydroethanolic extract from Mitragyna inermis (Willd.) O. Kuntze by gavage in the rat

In traditional medicine in Mali, extracts derived from Mitragyna inermis (Willd.) O. Kuntze (Family: Rubiaceae) are commonly used to treat malaria. The antimalarial activity and the lack of genotoxicity in vitro and in vivo have been demonstrated in previous studies. Acute and chronic evaluation of the toxicity of the hydroethanolic extract of Mitragyna inermis leaves was performed in this study, according to the recommendations (cahier de l'Agence no. 3) of the French Drug Office. Two dosages (300 mg/kg and 3 g/kg) were given in one single administration by gavage to male and female rats. No animal died and no behavioral signs of acute toxicity were observed. Chronic toxicity studies over 28 days showed no changes in body weight and no macroscopic abnormality in the 14 organs examined after the animals were sacrificed. With the 3 g/kg/d drug dosage (100-fold higher than those proposed in man), only slight histological abnormalities were observed. Statistically significant differences, compared to control animals, in the weight of some organs and the values of some haematological or biochemical parameters were observed. However, these values always remained in the range given by the breeder for naive animals of the same strain. These investigations thus seemed to indicate the safety of repeated oral administration (up to 3 g/kg/d) of the hydroethanolic extract of Mitragyna inermis leaves, which can therefore be continuously used with safety by the African population in traditional treatment of malaria.

Fasting apoprotein B-48 level and coronary artery disease in a population without frank fasting hypertriglyceridemia

The aim of this study was to test the hypothesis that fasting apoprotein B-48 level might be a surrogate marker of postprandial lipemia in evaluating the risk of coronary artery disease (CAD) in a population without frank abnormality in fasting lipid profile. One hundred twenty-three patients tested by coronary angiography were selected on the criteria of absence of treatment with hypolipidemic drugs, obvious hypertriglyceridemia (>2.85 mmol/L), or other conditions that may interfere with lipoprotein metabolism except diabetes. CAD was defined by more than 50% narrowing of vessel lumen, and its severity is determined by the number of arteries involved. Fasting apoprotein B-48 was measured by a competitive enzyme-linked immunosorbent assay method. There was no difference in fasting apoprotein B-48 levels between the groups with and without CAD (0.123+/-0.096 vs 0.136+/-0.125 microg/mL, respectively), whatever the sex or whether with or without diabetes. The apoprotein B-48 level was not related to the presence or the severity of CAD. There was also no correlation between fasting apoprotein B-48 levels and age, sex, body mass index, and usual fasting lipid parameters in both patients with and without angiographically proven CAD. Finally, among the features of metabolic syndrome, apoprotein B-48 was correlated with fasting triglyceride levels (r=0.357, P<.01) only. In conclusion, the present study shows that in the absence of any major fasting abnormality in plasma lipid parameters, fasting apoprotein B-48 level, which has been associated with postprandial hyperlipidemia, does not predict the risk of CAD.

The Medi-RIVAGE study: reduction of cardiovascular disease risk factors after a 3-mo intervention with a Mediterranean-type diet or a low-fat diet

BACKGROUND

Epidemiologic studies link Mediterranean-type diets to a low incidence of cardiovascular disease; however, few dietary intervention studies have been undertaken, especially in primary prevention.

OBJECTIVES

In the Mediterranean Diet, Cardiovascular Risks and Gene Polymorphisms (Medi-RIVAGE) study, the effects of a Mediterranean-type diet (Med group) or a low-fat diet (low-fat group) on risk factors were evaluated in 212 volunteers (men and women) with moderate risk factors for cardiovascular disease.

DESIGN

After the 3-mo dietary intervention, changes in many risk factors were evaluated. Dietary questionnaires and plasma nutritional markers were used to test compliance.

RESULTS

Although the dietary goals were only partially reached, changes in dietary habits were observed in both groups (n = 169): protein, carbohydrate, and fiber intakes increased and fat quality (decreased saturated fat and increased monounsaturated or polyunsaturated fat) improved. BMI, total and triacylglycerol-rich lipoprotein (TRL) cholesterol, triacylglycerols, TRL triacylglycerols, apolipoproteins A-I and B, insulinemia, glycemia, and the homeostasis model assessment score were significantly lower after 3 mo. The reductions in total cholesterol, triacylglycerols, and insulinemia remained significant after adjustment for BMI. There was a trend for a diet-by-time interaction for LDL cholesterol (P = 0.09). Our data predicted a 9% reduction in cardiovascular disease risk with the low-fat diet and a 15% reduction with this particular Mediterranean diet.

CONCLUSION

After a 3-mo intervention, both diets significantly reduced cardiovascular disease risk factors to an overall comparable extent.

Lutein transport by Caco-2 TC-7 cells occurs partly by a facilitated process involving the scavenger receptor class B type I (SR-BI)

The carotenoid lutein is thought to play a role in the human eye and to protect against age-related macular degeneration. Lutein transport in the human intestine has not been characterized. We examined lutein transport processes using Caco-2 TC-7 monolayers as a model for human intestinal epithelium. Purified lutein was mixed with phospholipids, lysophospholipids, cholesterol, mono-olein, oleic acid and taurocholate to obtain lutein-rich mixed micelles that mimicked those found under physiological conditions. The micelles were added to the apical side of Caco-2 TC-7 cell monolayers for 30 min or 3 h at 37 degrees C. Absorbed lutein, i.e. the sum of lutein recovered in the scraped cells and in the basolateral chamber, was quantified by HPLC. Transport rate was measured (i) as a function of time (from 15 to 60 min), (ii) as a function of micellar lutein concentration (from 1.5 to 15 microM), (iii) at 4 degrees C, (iv) in the basolateral to apical direction, (v) after trypsin pretreatment, (vi) in the presence of beta-carotene and/or lycopene, (vii) in the presence of increasing concentrations of antibody against SR-BI (scavenger receptor class B type 1) and (viii) in the presence of increasing concentrations of a chemical inhibitor of the selective transfer of lipids mediated by SR-BI, i.e. BLT1 (blocks lipid transport 1). The rate of transport of lutein as a function of time and as a function of concentration was saturable. It was significantly lower at 4 degrees C than at 37 degrees C (approx. 50%), in the basal to apical direction than in the opposite direction (approx. 85%), and after trypsin pretreatment (up to 45%). Co-incubation with beta-carotene, but not lycopene, decreased the lutein absorption rate (approx. 20%) significantly. Anti-SR-BI antibody and BLT1 significantly impaired the absorption rate (approx. 30% and 57% respectively). Overall, these results indicate that lutein absorption is, at least partly, protein-mediated and that some lutein is taken up through SR-BI.

Anionic Peptide Factor/Phosphatidylcholine Particles Promote the Inhibition of Vascular Cell Adhesion Molecule-1 in Human Umbilical Vein Endothelial Cells

OBJECTIVE

High-density lipoproteins (HDLs) have significant cardiovascular benefits by retarding the progression of atherosclerosis. One of the mechanisms is the inhibition by HDLs of the vascular cell adhesion molecule-1 (VCAM-1) expression in endothelial cells. Our objective was to test the effect on VCAM-1 expression by the human umbilical vein endothelial cells (HUVEC) of a minor HDL2 and HDL3 apolipoprotein, the anionic peptide factor (APF). The peptide has previously been found to develop some beneficial effects against atherosclerosis, i.e. by promoting the cholesterol efflux from endothelial cells.

METHODS

We examined the effects of two HDL apolipoproteins A-I and APF, either in presence or absence of phosphatidylcholines (PCs), or free PCs, on the expression of VCAM-1 by HUVEC. The cells were stimulated with either the tumor necrosis factor-alpha (TNFalpha, 500 pg/ml) or the calcium bound to heparin (10 microg Ca2+/ml, 50 microg heparin/ml).

RESULTS

In the presence of TNFalpha, only the free PCs (0.25 and 1 mM) developed an inhibitory effect (up to 50%). In the absence of TNFalpha and in the presence of calcium bound to heparin, either the lipid-free APF (3.5 microM) or the APF/PC complexes (1:57 molar ratio) or the free PCs (0.25 mM) exhibited a substantial inhibitory effect (72, 71 and 42%, respectively).

CONCLUSION

Our present findings suggest for the first time that one of the mechanisms of the antiatherogenic action of APF involves the inhibition of VCAM-1 expression by HUVEC. The peptide, through its phospholipid-binding and its calcium antagonist abilities, appears to confer on the HDLs a protective effect against the early cellular event of the inflammatory process.

Lipoprotein profile and prevalence of cardiovascular risk factors in urban Moroccan women

OBJECTIVE

The study aimed to characterize the lipid and apolipoprotein profile and the prevalence of cardiovascular risk factors in a population of urban adult women of Morocco.

DESIGN

A total of 213 women 25-55 y old were sampled from an agricultural province of Morocco: El Jadida. The following parameters of lipid and apolipoprotein profile were measured: plasma triglycerides (TG), plasma cholesterol (TC), triglyceride-rich lipoprotein triglycerides (TRL-TG), TRL-cholesterol (TRL-C), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and apolipoproteins A1, B, B48, CIII and E. Waist circumference (WC), body mass index (BMI) and blood pressure (BP) were also determined.

RESULTS

The women studied showed the following pattern: elevated TC, LDL-C levels and TC/HDL-C in 10, 19.4 and in 43.8%, respectively; low HDL-C levels in 45.3% (<0.9 mmol/l) or in 95% (when the cutoff <1.3 mmol/l is used), elevated TG levels in 11.8%. Elevated TRL-C (>0.6 mmol/l) and TRL-TG (>0.8 mmol/l) were observed in 13.4%. Obesity and hypertension were highly prevalent in 23.9 and 16.5%, respectively. Plasma triglyceride concentrations were closely correlated with plasma concentrations of TRL-TG (R = 0.86, P = 0.0001), apoB (R = 0.50, P = 0.0001) and apoCIII (R = 0.52, P = 0.0001) and moderately correlated with HDL-C levels (R = -0.3, P = 0.0001) and BMI (R = 0.4, P = 0.0001). The association between BMI and systolic blood pressure was statistically significant (R = 0.3, P = 0.0001). Obesity, BP, TRL-C, TRL-TG, TG, apoB and apoCIII increased with age.

CONCLUSION

There is a high prevalence of some risk factors for cardiovascular disease including altered lipid and lipoprotein profiles in the Moroccan urban women studied, some of these risk factors are associated with age.

Effect of lithium on norepinephrine metabolic pathways

We investigated lithium-induced changes in norepinephrine (NE) catabolism. NE and its major metabolites 3-methoxy-4-hydroxyphenylglycol (MHPG) and 3,4-dihydroxyphenyl glycol (DHPG), ions such as lithium (Li(+)), magnesium (Mg(2+)), and potassium (K(+)) were measured in rat plasma and cerebral cortex using an HPLC method with electrochemical detection for amines. The results obtained with a group of rats treated by lithium chloride (2 mmol/kg/IP) were compared with a control group receiving sodium chloride (2 mmol/kg/IP). Animals were killed at different times over a period of six hours in the morning following salt administration to minimize possible chronobiological effects. There are two pathways leading to MHPG formation: way A, without DHPG, and way B, with DHPG. In plasma and cerebral cortex of lithium treated rats, way A catabolism seems to be preferential. Lithium increases Mg(2+) and K(+) plasma levels. These results suggest that lithium may increase inactivation of NE and decrease NE available for adrenergic receptors.

NH2 terminal pro–brain natriuretic peptide plasma level as an early marker of prognosis and cardiac dysfunction in septic shock patients*

OBJECTIVE

To investigate N-terminal pro-brain natriuretic peptide (NT-proBNP) level as a prognostic factor and a marker of myocardial dysfunction in patients with septic shock.

DESIGN

Prospective observational study.

SETTING

Intensive care unit.

SUBJECTS

A total of 39 patients diagnosed with septic shock and requiring mechanical ventilation.

MEASUREMENTS AND MAIN RESULTS

Demographic, hemodynamic, respiratory, and biological data (notably NT-proBNP, lactate, and cardiac troponin I) were collected at inclusion and every 12 hrs. The independent factors for death were higher Sequential Organ Failure Assessment score in the 24-hr period after inclusion (odds ratio, 4.7; 95% confidence interval, 1.15-19.3) and the highest NT-proBNP level in the 24-hr period after inclusion (odds ratio, 1.12 per 1000 pg/mL increase; 95% confidence interval, 1.05-1.26). An NT-proBNP of >13,600 pg/mL predicted intensive care unit mortality with an accuracy of 77%. Area under the receiver operating characteristic curve was 0.8 (p = .002; 95% confidence interval, 0.66-0.93). NT-proBNP levels were over the accepted normal range in all patients. Values were highest between 24 and 36 hrs after onset of septic shock and were significantly higher in nonsurvivors at each time between inclusion and day 7. The lowest left ventricular stroke work index of the first 24-hr period after inclusion was the only factor that independently influenced higher NT-proBNP levels at the same time (odds ratio, 0.91; 95% confidence interval, 0.84-0.98).

CONCLUSION

NT-proBNP seems to be an early factor of prognosis and myocardial dysfunction in patients with septic shock.

Enrichment of tomato paste with 6% tomato peel increases lycopene and beta-carotene bioavailability in men

A high intake of tomato products is associated with a lower incidence of upper aerodigestive tract and prostate cancers. This beneficial effect might be explained by a higher intake of carotenoids such as lycopene and/or beta-carotene. Because tomato peels, usually eliminated during tomato processing, are a valuable source of these carotenoids, we designed a study to examine whether a tomato paste enriched in tomato peels (ETP, 6% peel) increases the absorption of these carotenoids compared to a classically made tomato paste (CTP). Carotenoid bioaccessibility was evaluated using an in vitro digestion model by measuring the amount of carotenoids transferred from the pastes to micelles. Carotenoid absorption by human intestinal cells (Caco-2) was evaluated after the addition of carotenoid-rich micelles (obtained from the in vitro digestion of the 2 pastes). Carotenoid bioavailability in humans was assessed by measuring chylomicron carotenoid responses in a postprandial experiment in which 8 healthy men consumed 2 meals containing either the ETP or the CTP. ETP contained 47.6 mg lycopene (58% more than CTP) and 1.75 mg beta-carotene (99% more than CTP) per 100 g of paste. In micelles, 30% more lycopene and 81% more beta-carotene were recovered after ETP than after CTP in vitro digestion. The amount of carotenoids absorbed by Caco-2 cells was 75% greater (P < or = 0.05) for lycopene and 41% greater (P < or = 0.05) for beta-carotene after the addition of micelles from ETP than from CTP. After ETP intake the chylomicron beta-carotene response was 74% greater than after CTP intake, and the lycopene response tended to be greater (34.1%, P = 0.093). Peel enrichment of tomato paste with tomato peel is an interesting option for increasing lycopene and beta-carotene intakes.

Antifungal effect of various essential oils againstCandidaalbicans. Potentiation of antifungal action of amphotericin B by essential oil fromThymus vulgaris

The antifungal effect of the essential oil from Satureja montana L., Lavandula angustifolia Mill., Lavandula hybrida Reverchon, Syzygium aromaticum (L.) Merril and Perry, Origanum vulgare L., Rosmarinus officinalis L. and six chemotypes of Thymus vulgaris L. on Candida albicans growth were studied. The most efficiency was obtained with the essential oil from Thymus vulgaris thymol chemotype (MIC 80% = 0.016 microL/mL and Kaff = 296 microL/mL). The presence in the culture medium of essential oil from Thymus vulgaris thymol chemotype (0.01, 0.1, 0.2, 0.3 microg/mL) and amphotericin B involved a decrease of the MIC 80% of amphotericin B. In contrast, the combination of amphotericin B and low concentrations (0.00031-0.0025 microg/mL) of essential oil was antagonistic. The strongest decrease (48%) of the MIC 80% was obtained with medium containing 0.2 microL/mL of essential oil. These results signify that the essential oil of Thymus vulgaris thymol chemotype potentiates the antifungal action of amphotericin B suggesting a possible utilization of this essential oil in addition to antifungal drugs for the treatment of mycoses.

High-fat diets impede the lowering effect of cyclosporine a on rat brain lipids and interact with the expression of apolipoproteins E and J

Cyclosporine A (CsA), a common immunosuppressive agent, produces hyperlipidemia and apolipoprotein profile alterations in plasma as well as neurological and psychiatric complications. In rats, 10 mg CsA/kg/d treatments for 3 wk induce alterations of the electroencephalogram, and of the blood and brain lipids. Using this model, we evaluated whether triacylglycerol (TG)- and lecithin (PC)-enriched diets, reported to decrease epileptic episodes (TG) and to improve memory, could modify the effects of CsA treatment on brain lipids and possibly change apolipoprotein (apo) E and apoJ gene expression. To evaluate this hypothesis, three groups of rats were treated for 3 wk with CsA and received a low-fat, PC, or TG diet. Three other groups were fed the above-mentioned diets and were treated with the CsA solvent. As a control, one group was fed only the low-fat diet. The CsA-mediated decreases in brain cholesterol and PC contents, under a low-fat diet, were eliminated by the TG and PC diets. These high-fat diets induced a global increase in hippocampal transcriptional activity, as revealed by elevated polyadenylated RNA levels. The apoE and apoJ mRNA levels in the cortex and hippocampus of rats receiving the solvent were not statistically different between the TG- and PC-enriched diets but showed important variations compared with the low-fat diet solvent-treated group. A differential effect between the two high-fat diets was observed in the hippocampus, resulting in a significant increase of the apoE to apoJ ratio with the PC diet. The balance between apoE and apoJ is presumed to be important in encephalopathic mechanisms, by its involvement through low levels of brain cholesterol and PC, that might be associated with mental disorders. Our results therefore suggest that diet enrichment with polyunsaturated fat might be beneficial during CsA therapy. However, if the high levels in PC used here are more beneficial on CsA peripheral side effects than similar enrichment in TG, this does not seem to be the case in the brain. Thus, lower levels in PC should be tested.

Usefulness of N-terminal-pro-brain natriuretic peptide levels in predicting survival in heart transplant recipients

We evaluated the prognostic value of plasma N-terminal-pro-brain natriuretic peptide (NT-pro-BNP) in 71 transplanted heart recipients during a 38 +/- 2 month follow-up. The negative predictive value of NT-pro-BNP levels </=800 pg/ml to predict death was 97% (95% confidence interval 92 to 100). Thus, NT-pro-BNP levels </=800 pg/ml predict a middle-term good survival in transplanted heart recipients.

Glycemic and insulinemic meal responses modulate postprandial hepatic and intestinal lipoprotein accumulation in obese, insulin-resistant subjects

BACKGROUND

Exacerbated postprandial lipemia is a risk factor for cardiovascular disease and is linked to insulin status. Limited data on the effect of dietary carbohydrate on postprandial lipoprotein accumulation are available.

OBJECTIVE

We tested the hypothesis that dietary carbohydrates with different glucose availability alter postprandial lipoprotein metabolism differently in obese, insulin-resistant subjects.

DESIGN

After an overnight fast, 9 subjects with central obesity and insulin resistance but normal triacylglycerolemia randomly ingested 2 test meals with comparable amounts of fat (28-29 g) and digestible carbohydrate (91-94 g) but with different quantities of slowly available glucose (SAG) in cereal products (17 or 2 g SAG/100 g for biscuits and wheat flakes, respectively). Blood samples were collected before and for 6 h after meal intakes.

RESULTS

The postmeal 0-2-h areas under the curve (AUCs) for glycemia and insulinemia were significantly lower (P < 0.05) after the biscuit meal than after the flakes meal. Plasma triacylglycerol concentrations increased significantly after the flakes meal but not after the biscuit meal (1.5-fold higher 0-6-h AUC for the flakes meal). Apolipoprotein B-100 concentrations in the triacylglycerol-rich lipoprotein fraction increased significantly 2 h after the flakes meal but not after the biscuit meal (3-fold higher 0-6-h AUC for the flakes meal). Apolipoprotein B-48 concentrations increased (P < 0.05) 4 h after the flakes meal but not after the biscuit meal (2.3-fold higher 0-6-h AUC for the flakes meal).

CONCLUSION

Mixed meals containing slowly digestible carbohydrate that induces low glycemic and insulinemic responses reduce the postprandial accumulation of both hepatically and intestinally derived triacylglycerol-rich lipoproteins in obese subjects with insulin resistance.

The Medi-RIVAGE study (Mediterranean Diet, Cardiovascular Risks and Gene Polymorphisms): rationale, recruitment, design, dietary intervention and baseline characteristics of participants

OBJECTIVE

To report the rationale, recruitment, design, dietary intervention and baseline characteristics of participants in the Medi-RIVAGE study (Mediterranean Diet, Cardiovascular Risks and Gene Polymorphisms).

DESIGN

A randomised, parallel trial comparing a new nutritional programme with a conventional programme.

SETTING

Centre for Detection and Prevention of Arteriosclerosis, Timone University Hospital, Marseille, France, and collaborating teams.

SUBJECTS

Two hundred and twelve male and female volunteers with at least one cardiovascular risk factor.

INTERVENTION

A Mediterranean-type diet characterised mainly by the quality of fatty acids, amount of fish, vegetable foodstuffs and fibre was proposed and compared with a usually prescribed, low-fat/cholesterol diet. Body mass index, fasting lipids and lipoproteins, apolipoproteins, glucose, insulin and homocysteine were the main outcome measures. Gene polymorphisms of interest were determined.

RESULTS

Characteristics of men in the two arms were comparable with regard to sociodemographic variables, and clinical and biological cardiovascular risk factors. There were few differences between the groups of women (cholesterol-related parameters, P<0.05). There was no difference between arms in allelic distribution of the gene polymorphisms studied. Saturated fat and protein intakes were high while carbohydrate and fibre intakes were low, but with no difference between arms. Overall, the nutritional markers were comparable in both arms with few exceptions. Correlations between nutritional intakes and plasma nutrient levels ranged from 0.19 (beta-carotene) to 0.47 (folate).

CONCLUSIONS

The comparability of the two arms is notable and warrants a low risk of biases. Current diet departs from the traditional Mediterranean one. The assessment of nutritional intake is validated by correlations obtained between dietary intake and relevant biomarkers. This will be important to estimate participant compliance and to analyse intervention data.

Docosahexaenoic acid-enriched egg consumption induces accretion of arachidonic acid in erythrocytes of elderly patients

Many studies in humans volunteers have shown that dietary docosahexaenoic acid (DHA) supplied as triacylglycerol can increase DHA levels in blood lipids but often strongly decreases those of arachidonic acid (AA). The aim of the present study was to determine the effect of dietary supplementation with egg-yolk powder enriched in DHA, corresponding to the French recommended dietary allowance for DHA, on the blood lipid status of an elderly population. Institutionalised elderly individuals aged between 63 and 93 years consumed an egg product enriched in DHA (150 mg/d) once daily for 9 months. Plasma lipids and the fatty acid composition of erythrocyte membranes were determined every 3 months. The supplementation induced an increase in the PUFA content of plasma and erythrocyte membranes which was +14.5 and +25.3 %, respectively, at 9 months. This effect was mainly due to the level of DHA and, unexpectedly, to that of AA which continuously increased. This increase in AA was the result of an increased dietary intake (+50 mg/d) and very probably of an increased biosynthesis as demonstrated by the behaviour of di-homo-gamma-linolenic acid. The supplementation resulted in a blood PUFA status comparable with that of young healthy controls. The data are consistent with a strong regulatory action of the dietary treatment on the subjects' lipid metabolism.

Exclusive expression of transmembrane TNF-alpha in mice reduces the inflammatory response in early lipid lesions of aortic sinus

We investigated the effect of transmembrane form of tumor necrosis factor-alpha (TNF) on atherosclerosis in mice. We compared the development of early atherosclerotic lesions in the aortic sinus of (1) TNF-deficient mice that express only a non-cleavable transmembrane form of TNF (tmTNF), (2) wild-type (WT) C57BL/6 mice, and (3) TNF-deficient mice (TNF(-/-)). All mice were fed an atherogenic diet for 20 weeks. Lipid deposition was the most prominent in WT mice (25030 +/- 5693 microm2), tended to be lower in tmTNF mice (13640+/- 2190 microm2, P > 0.05 versus WT mice) and rare in TNF(-/-) mice (1408 +/- 513 microm2, P < 0.05 versus tmTNF and P < 0.01 versus WT). Macrophage accumulation was five-fold lower (P < 0.05) in tmTNF than in WT mice. In addition, the alpha-actin immuno-reactivity of medial smooth muscle cells remained intact in tmTNF mice but not in WT mice. In WT mice, the plasma lipid profile was significantly more atherogenic than that of TNF(-/-) mice (P < 0.05), but not significantly different from that of tmTNF mice (P > 0.05). These results indicated that in contrast to TNF(-/-) mice, mice expressing exclusively tmTNF were not completely protected from early atherosclerotic lesion formation, although their lesions have a less inflammatory state than those of WT mice, which underlines the stronger proinflammatory potential of soluble TNF.

Method for simultaneous measurement of norepinephrine, 3-methoxy-4-hydroxyphenylglycol and 3,4-dihydroxyphenylglycol by liquid chromatography with electrochemical detection: application in rat cerebral cortex and plasma after lithium chloride treatment

An assay was developed to quantify norepinephrine (NE) and its metabolites (MHPG and DHPG) by high-performance liquid chromatography with electrochemical detection method (HPLC-ECD) in brain tissue and plasma of rats treated by LiCl. Separation on C(18) column was obtained by a mobile phase consisting of 4.5% methanol in buffer (0.1 M sodium acetate, 0.2 M citric acid) containing 0.2 mM ethylenediaminetetraacetic acid disodium salt (EDTA Na(2)) and 0.4 mM sodium octylsulfate, operated at a flow rate of 0.8 ml/min. A potential of +0.78 V was applied across the working and reference electrodes of the detector. The precision was in the range 2.88-4.35% for NE, 5.94-11.0% for MHPG and 1.97-4.40% for DHPG. Accuracy was 98.8-99.3% for NE, 97.4-100% for MHPG and 96.1-101% for DHPG. The limit of detection was 0.6 ng/ml for NE, 0.5 ng/ml for MHPG and 0.2 ng/ml for DHPG. The linearity is over the range 20-60 ng/ml for NE, 7-23 ng/ml for MHPG and 6-20 ng/ml for DHPG. The assay has been applied successfully to measure simultaneously cortex and plasmas concentrations of these three catecholamines in rats.

Pharmacokinetics of the low molecular weight heparin enoxaparin during 48 h after bolus administration as an anticoagulant in haemodialysis

BACKGROUND

The interest of low molecular weight heparins (LMWH) regarding bleeding risk is controversial in renal failure patients. In haemodialysis patients, there are very few data on the pharmacokinetics of LMWH after the end of the session. The aim of the study was to evaluate the duration of anticoagulation after bolus administration of the LMWH enoxaparin at the start of haemodialysis.

METHODS

The pharmacokinetics of enoxaparin were studied during the 48 h following a single bolus injection at the start of the dialysis session in 30 chronic haemodialysis patients. Pharmacokinetics were determined using a population approach (Non Linear Mixed Effects Modelling).

RESULTS

A single injection of enoxaparin at 60 U IU/kg (4000 +/- 455 IU) led to an anti-Xa activity higher than 1.2 IU/ml during the first 2 h of the session, and between 0.4 and 1.2 IU during the third and fourth hours. After the end of the session, anti-Xa activity remained higher than 0.4 IU/ml up to 10 h after injection, and higher than 0.1 IU/ml up to 24 h. The pharmacokinetic model showed that only weight improved the predicted vs observed anti-Xa activity plot. The model was used to simulate single and multiple dosing with decreased enoxaparin doses. Whatever the procedure, anti-Xa activity remained high (>0.22 +/- 0.99 UI/ml) up to 12 h after the start of the dialysis session.

CONCLUSIONS

These results suggest that haemodialysis patients receiving the LMWH enoxaparin during dialysis are at risk of bleeding up to 10 h after the injection.