Acid Plasma Concentrations Research Articles

Early post-traumatic seizures are associated with valproic acid plasma concentrations and UGT1A6/CYP2C9 genetic polymorphisms in patients with severe traumatic brain injury

BackgroundSeizure is a common complication for severe traumatic brain injury (TBI). Valproic acid (VPA) is a first-line antiepileptic drug, though its metabolism is affected by genetic polymorphisms and varies between individuals. The aim of this study was to investigate such association and to explore its influence on the occurrence of early post-traumatic seizure.MethodsA prospective case control study was conducted from 2012 to 2016 recruiting adult patients with severe TBI. Electroencephalograph (EEG) monitoring was performed approximately 4 h for each patient from day 1 to day 7 after injury. If seizures were detected, EEG monitoring was extended until 12 h after seizures being controlled. Genetic polymorphisms in UGT1A6, UGT2B7, CYP2C9, and CYP2C19 were analyzed in association with daily VPA plasma concentrations, adjusted dosages, and occurrence of seizures.ResultsAmong the 395 recruited patients, eighty-three (21%) had early post-traumatic seizure, of which 30 (36.14%) were non-convulsive. Most seizures were first detected on day 1 (34.94%) and day 2 (46.99%) after injury. Patients with seizure had longer ICU length of stay and relatively lower VPA plasma concentrations. Patients with UGT1A6_19T > G/541A > G/552A > C double heterozygosities or CYP2C9 extensive metabolizers (EMs) initially had lower adjusted VPA plasma concentrations (power >0.99) and accordingly require higher VPA dosages during later time of treatment (power >0.99). The odds ratio indicated a higher risk of early post-traumatic seizure occurrence in male patients (OR 1.96, 95% CI 1.01-3.81, p = 0.043), age over 65 (OR 2.13, 95% CI 1.01-4.48), and with UGT1A6_19T > G/541A > G/552A > C double heterozygosities (OR 2.38, 95% CI 1.11-5.10, p = 0.02), though the power of the difference was between 0.54 to 0.61.DiscussionDue to limited facility, the actual frequency of non-convulsive seizures is suspected to be higher than identified. There has been discrepancy regarding to genetic polymorphisms and VPA metab olism between this study and some previous reports. This could be related to confounders such as sample size, race, and patient age. Another limitation is that the case numbers of certain genotypes are limited in this study.ConclusionsContinuous EEG monitoring is necessary to detect both convulsive and non-convulsive early post-traumatic seizures in severe TBI patients. UGT1A6/CYP2C9 polymorphisms have influence on VPA metabolism. UGT1A6_19T > G/541A > G/552A > C double heterozygositie is associated with occurrence of early post-traumatic seizures in addition to patients’ age and gender. Further investigations with larger sample size are required to confirm the difference.Trial registrationRetrospectively registered with Chinese Clinical Trail Registry on 1st Jan 2016 (ChiCTR-OPC-16007687)

187 Early Post-Traumatic Seizures are Associated with Valproic Acid Plasma Concentrations and UGT1A6/CYP2C9 Genetic Polymorphisms in Patients with Severe Traumatic Brain Injury

Abstract INTRODUCTION Seizure is a common complication for severe traumatic brain injury (TBI). Valproic acid (VPA) is a first-line antiepileptic drug, though its metabolism is affected by genetic polymorphisms and varies between individuals. The aim of this study was to investigate such association and to explore its influence on the occurrence of early post-traumatic seizure. METHODS A case control study was conducted from 2012 to 2016 recruiting adult patients with severe TBI. Continuous electroencephalograph (EEG) monitoring was performed for 7 days. Genetic polymorphisms in UGT1A6, UGT2B7, CYP2C9, and CYP2C19 were analyzed in association with daily VPA plasma concentrations, adjusted dosages, and occurrence seizures. RESULTS >Among the 395 recruited patients, eight-three (21%) had early post-traumatic seizure, of which 30 (36.14%) were non-convulsive. Most seizures were first detected on day 1 (34.94%) and day 2 (46.99%) after injury. Patients with seizure had longer ICU length of stay and relatively lower VPA plasma concentrations. Patients with UGT1A6_19T>G/541A>G/552A>C double heterozygosities or CYP2C9 extensive metabolizers (EMs) initially had lower adjusted VPA plasma concentrations (power >0.99) and accordingly require higher VPA dosages during later time of treatment (power >0.99). The odds ratio indicated a higher risk of early post-traumatic seizure occurrence in male patients (OR 1.96, 95% CI 1.01-3.81, P = 0.043), age over 65 (OR 2.13, 95% CI 1.01-4.48), and with UGT1A6_19T>G/541A>G/552A>C double heterozygosities (OR 2.38, 95% CI 1.11-5.10, P = 0.02). CONCLUSION Continuous EEG monitoring are necessary to detect both convulsive and non-convulsive early post-traumatic seizures in severe TBI patients. UGT1A6/CYP2C9 polymorphisms have influence on VPA metabolism. UGT1A6_19T>G/541A>G/552A>C double heterozygositie is associated with occurrence of early post-traumatic seizures in addition to patients' age and gender. Further investigations with larger sample size are required to confirm the difference.

Lysophosphatidic acid plasma concentrations in healthy subjects: circadian rhythm and associations with demographic, anthropometric and biochemical parameters

BackgroundLysophosphatidic acid (LPA) is a bioactive lipid with a wide biological activity. Previous studies have shown its potential usefulness as a diagnostic marker for ovarian cancer. The aim of the study was to investigate which factors may influence plasma LPA concentrations in healthy subjects and to propose reference values.MethodsThe study group consisted of 100 healthy subjects. From all of them the blood samples were taken at 7 a.m. (fasting state). From 40 volunteers additional blood samples were taken at 2 p.m., at 8 p.m. and at 2 a.m. next morning. Concentrations of LPA were measured in plasma samples using enzyme-linked immunosorbent assay.ResultsAnalysis of samples from 100 healthy volunteers showed significant influence of sex and age on plasma LPA. The reference range for the plasma LPA concentration corrected for age and sex, determined at 2.5–97.5 percentile interval is 0.14–1.64 μM. LPA correlates positively with BMI, serum total cholesterol, triacylglycerols, uric acid and negatively with estimated glomerular filtration rate and serum albumin. Concentration of LPA at 2 a.m. was lower than at 2 p.m. There were not any significant differences between plasma LPA at 7 a.m. and any other time of the day.ConclusionsPlasma LPA is associated with demographic, anthropometric and biochemical parameters. It seems that LPA concentrations have no specific circadian rhythm and the time of donation and fasting state have marginal effect on plasma LPA. These findings may be helpful in future incorporation of LPA as a diagnostic marker.

Genetic polymorphisms and valproic acid plasma concentration in children with epilepsy on valproic acid monotherapy

PurposeThe aim of the study is to evaluate the association between genetic polymorphisms and valproic acid (VPA) concentration to dose ratio in children with epilepsy on VPA monotherapy. MethodsA total of 137 children, aged 3.5–18 years, (89 males and 48 females) with epilepsy on sustained-release VPA monotherapy were enrolled. Trough plasma concentrations of VPA at steady-state were measured using an AXSYM automatic immunity analyzer. The values were divided by body weight and total daily dose to calculate concentration to dose ratio of VPA (CDRV). Forty-eight single nucleotide polymorphisms involved in the pharmacokinetics of VPA were identified by MassARRAY system. The logarithmic transformed CDRV (lnCDRV) was normally distributed, and PLINK software was used to evaluate the association between genetic polymorphisms and lnCDRV using linear regression adjusted for gender and seizure type. Resultsrs28898617 (UGT1A3/4/5/6/7/8/9/10, BETA=0.32, P=0.0089) was significantly associated with higher lnCDRV. No other associations were found. ConclusionsIn pediatric patients taking VPA monotherapy, rs28898617 was associated with a higher normalized VPA plasma concentration. Further studies are warranted to confirm the results.

Branched-chain amino acid catabolism rather than amino acids plasma concentrations is associated with diet-induced changes in insulin resistance in overweight to obese individuals

Background & aims3-Hydroxyisobutyrate (3-HIB), a catabolic intermediate of the BCAA valine, which stimulates muscle fatty acid uptake, has been implicated in the pathogenesis of insulin resistance. We tested the hypothesis that circulating 3-HIB herald insulin resistance and that metabolic improvement with weight loss are related to changes in BCAAs and 3-HIB. Methods and resultsWe analyzed plasma and urine in 109 overweight to obese individuals before and after six months on hypocaloric diets reduced in either carbohydrates or fat. We calculated the homeostasis model assessment index (HOMA-IR) and whole body insulin sensitivity from oral glucose tolerance tests and measured intramyocellular fat by magnetic resonance spectroscopy. BCAAs and 3-HIB plasma concentrations were inversely related to insulin sensitivity but not to intramyocellular fat content at baseline. With 7.4 ± 4.5% weight loss mean BCAA and 3-HIB plasma concentrations did not change, irrespective of dietary macronutrient content. Individual changes in 3-HIB with 6-month diet but not BCAAs were correlated to the change in whole body insulin sensitivity and HOMA-IR independently of BMI changes. Conclusions3-HIB relates to insulin sensitivity but is not associated with intramyocellular fat content in overweight to obese individuals. Moreover, changes in 3-HIB rather than changes in BCAAs are associated with metabolic improvements with weight loss.Registration number for clinical trials: ClinicalTrials.gov Identifier: NCT00956566.

Isolation and Probiotic Potential of Lactobacillus Salivarius and Pediococcus Pentosaceus in Specific Pathogen Free Chickens

ABSTRACT This study was conducted to isolate Lactobacillus salivarius and Pediococcus pentosaceus strains from cecal content and investigate their probiotic potential in specific pathogen free (SPF) chickens. L. salivarius and P. pentosaceus strains were isolated from the cecal content of SPF chickens and identified by 16s rDNA sequence analysis by BLAST analysis at the National Center for Biotechnology Information and phylogenetic analysis using DNAStar software. In an in vivo experiment, 180 7-day-old SPF chickens were randomly assigned into three groups. Group 1 served as a control that was fed a basal diet without probiotic supplementation, and groups 2 and 3 were fed the basal diets supplemented with L. salivarius and P. pentosaceus at 2×108 CFU/g, respectively. Body weight (BW), average daily gain (ADG), feed conversion ratio (FCR), dressing percentage (DP), and the apparent digestibility of crude protein (AD-CP) were calculated. We also determined meat color, fat content, shear force, water content and pH value of breast and thigh muscles; ammonia, urea nitrogen and uric acid content in plasma; fecal ammonia emission level and pH value; and Lactobacillus and Escherichia coli in ceca. Compared with the control group, L. salivarius and P. pentosaceus supplementation significantly increased BW, ADG, DP, AD-CP, fat content of meat, and the number of Lactobacillus in ceca (p<0.05), and decreased FCR, plasma ammonia content, fecal ammonia emission, and pH value and the number of E. coli in ceca (p<0.05). In the in vitro experiment, L. salivarius and P. pentosaceus treatments significantly decreased the ammonia content in medium compared with the control group without probiotic treatment (p<0.05). These results suggest that P. pentosaceus and L. salivarius strains show promising probiotic properties for improving growth, meat quality and microenvironment in chickens and decreasing ammonia content in the medium.

Metabolic Differences in Essential Amino Acid Plasma Concentrations in High‐ and Low‐Active Mice

BACKGROUNDWith current health problems such as obesity and Type II Diabetes attributable to both physical inactivity and metabolic disorders, there continues to be a lack of information regarding physiological mechanistic interactions between physical activity and metabolism.PURPOSETo conduct basic metabolic analysis on mice either high‐ active (HA) (C57L/J) or low‐active (LA) (C3H/HeJ), and determine basic metabolic differences between essential amino acids (EAA) in these activity types.METHODSAll procedures were approved by the TAMU IACUC. At 12wks of age, 20 HA male mice (body weight: 27.5±1.2g; lean mass: 22.5±1.3g; fat mass: 2.5±0.7g; food intake: 3.4±0.8g) and 23 LA male mice (body weight: 25.8 ±1.2g; lean mass: 21.0±1.1g; fat mass: 2.5±0.5g; food intake: 3.0±1.0g) (Jackson Labs) under anesthesia had a catheter placed in the right jugular vein for blood sampling. Plasma EAA concentrations were determined by LC‐MS/MS. Data were analyzed using unpaired t‐tests for each EAA.RESULTSLA mice had significantly higher EAA for THR, VAL, MET, ILE, LEU, TRP and HIS (Table). LYS was the only essential AA with a significantly lower concentration.CONCLUSIONWe hypothesize that the consistent higher EAA plasma concentrations in LA strain mice indicate a modified essential AA metabolism that is linked to their lower activity levels.Support or Funding InformationStudy funded by research development grant from the Vice‐President of Research, Texas A&amp;M University Amino Acid Low Active (n=20) High Active (n=23) Difference P Threonine (THR) 206.7 ± 9.8 161.4 ± 6.7 −45.3 ± 11.9 0.0005 Valine (VAL) 187.9 ±7.1 156.8 ± 4.9 −31.1 ± 8.6 0.0008 Methionine (MET) 60.9 ± 2.7 47.3 ± 1.5 −13.6 ± 3.1 0.0001 Isoleucine (ILE) 57.7 ± 2.3 48.5 ± 1.9 −9.2 ± 3.0 0.0041 Leucine (LEU) 144.8 ± 6.4 125.2 ± 4.8 −19.6 ± 8.0 0.0184 Tryptophan (TRP) 71.1 ± 3.0 58.2 ± 2.3 −13.0 ±3.8 0.0016 Phenylalanine (PHE) 86.7 ± 4.3 77.5 ± 2.4 −9.2 ± 4.9 0.0724 Histidine (HIS) 109.3 ± 3.9 92.4 ± 2.8 −16.8 ± 4.8 0.0011 Lysine (LYS) 379.9 ± 17.2 481.4 ± 18.2 101.5 ± 25.0 0.0002 Sum EAA 1305.0 ± 56.7 1248.7 ± 45.5 −56.3 ± 73.1 0.9139 Plasma concentrations in μm. Data are mean ± SE.

Metabolic Differences in Nonessential Amino Acid Plasma Concentrations in High‐ and Low‐Active Mice

BACKGROUNDThere continues to be a lack of information regarding physiological mechanistic interactions between physical activity and metabolism. This is important in relation to obesity and Type II Diabetes.PURPOSETo conduct basic metabolic analysis on mice either high‐ active (HA) (C57L/J) or low‐active (LA) (C3H/HeJ), and determine basic metabolic differences between non‐essential amino acids pathways (NEAA).METHODSAll procedures were approved by the TAMU IACUC. At 12wks of age, 20 HA male mice (body weight: 27.5±1.2g; lean mass: 22.5±1.3g; fat mass: 2.5±0.7g; food intake: 3.4±0.8g) and 23 LA male mice (body weight: 25.8 ±1.2g; lean mass: 21.0±1.1g; fat mass: 2.5±0.5g; food intake: 3.0 ±1.0g) (Jackson Labs) under anesthesia had a catheter placed in the right jugular vein for blood sampling. Plasma NEAA concentrations were determined by LC‐MS/MS. Data were analyzed using unpaired t‐tests for each NEAA.RESULTSLA mice had significantly higher NEAA for GLU, ALA, CIT, ORN and for SER. Remarkable no change in GLN, ARG and GLY (Table).CONCLUSIONIn LA strain mice, specific changes in the GLU/GLN and ARG/CIT/ORN and GLY/SER pathway are observed suggesting modified pathways, linked to their lower activity levels.Support or Funding InformationStudy funded by research development grant from the Vice‐President of Research, Texas A&amp;M University Amino Acid Low Active (n=20) High Active (n=23) Difference P Glutamic Acid (GLU) 36.8 ± 3.0 17.5 ± 2.0 −19.3 ± 3.6 &lt;0.0001 Glutamine (GLN) 641.8 ± 23.9 633.7 ± 20.7 −8.0 ± 31.6 0.8011 Citrulline (CIT) 57.3 ± 2.3 46.4 ±1.5 −10.9 ± 2.8 0.0003 Serine (SER) 185.2 ± 7.1 152.3 ±5.4 −32.9 ± 8.8 0.0006 Glycine (GLY) 401.0 ± 15.4 399.0 ± 12.0 −2.1 ± 19.5 0.9167 Arginine (ARG) 104.6 ± 6.7 106.7 ± 4.2 2.1 ± 7.9 0.7895 Alanine (ALA) 671.5 ± 39.3 453.6 ± 18.7 −217.9 ±43.6 &lt;0.0001 Ornithine (ORN) 55.4 ± 7.3 36.9 ± 2.6 −18.6 ± 7.8 0.0241 SUM NEAA 2153.6 ±105.0 1846.1 ±67.1 −307.6 ± 125.6 0.7632 Plasma concentrations in μM. Data are mean ± SE.

Validasi Metode HPLC untuk Penetapan Aspirin dan Asam Salisilat dalam Plasma Kelinci (Lepus curpaeums) secara Simultan

Aspirin is a nonsteroidal anti-inflammatory drug which also has the effect of antiplatelet for stroke prevention. Aspirin inside human body is very easy to break down into salicylic acid as the main metabolite. The aim of this study is to develop and validate the method for determinating aspirin and salicylic acid concentration in plasma by HPLC. M ethod validation includ ing system suitability test, linearity test , determination of LOD and LOQ, recovery, accuracy and precision. Concentration of analytes in blood is measured by HPLC using benzoic acid as internal standard, with condition Purospher column Endcapped Star RP-18 (250 x 4.6 mm id, 5 m), acetonitrile : buffer phosphate 20 mM pH 2.5 (30:70 v/v) as mobile phase , injection volume 20 mL, flow rate 1.5 mL/minute, and UV-Vis detector λ 230 nm. The results showed that the proposed method meets the requirements of system suitability and good linearity (r > 0,990) with LOQ (aspirin = 0.024 mg/mL, salicylic acid = 0.336 mg/mL) and LOD (aspirin = 0.007 mg/mL, salicylic acid = 0.101 mg/mL). The method of analysis provides recovery of 85-115 %, accuracy and precision in accordance with the requirements for bioanalytical with CV < 5 %. Therefore, the proposed method is applicable to determine of aspirin and salicylic acid concentration in plasma.

Comparison of LC-MS/MS vs chemiluminescent microparticle immunoassay in measuring the valproic acid concentration in plasma of epilepsy patients in a new perspective.

This study was designed to compare the performance of LC-MS/MS with chemiluminescent microparticle immunoassay (CMIA) for determination of VPA in epilepsy patients in the perspective of metabolites' hepatotoxicity. Samples were collected and then analyzed using both LC-MS/MS and CMIA. A LO2 cells (normal human hepatic cells) experiment was carried out to confirm VPA metabolites' hepatotoxicity using AST(Aspertate Aminotransferase, AST), ALT(Alanine aminotransferase, ALT) and LDH(lactate dehydrogenase, LDH) in supernate as index. The regression equation analysis showed as LC-MS/MS=1.0094CMIA-1.8937, with the concordance correlation coefficient of 0.9700, and the CUSUM test proved no significant deviation from linearity (P>.05). CMIA compared to LC-MS/MS gave a positive bias of 1.2μg/mL. In LO2 experiment, VPA and its metabolites groups showed an obvious increment of AST, ALT, and LDH in supernate. The LC-MS/MS is largely consistent with the CMIA in analytical time and quantification ability for VPA, but the LC-MS/MS can simultaneously determinate VPA and its metabolites in plasma, and is also a higher cost-efficiency method in consideration of toxic metabolites monitoring. The overestimation of VPA by CMIA showed no clinical significance. The metabolites 3-OH-VPA and 5-OH-VPA damage the LO2 cells and the results presented a statistical significance (P<.05). It is vital to monitor the metabolites' concentrations for VAP's clinical safety application, and now is the occasion that laboratory and clinic consider the LC-MS/MS method as a more advantageous alternative to CMIA method in therapeutic monitoring of VPA.

Drug-drug interaction between valproic acid and meropenem: a retrospective analysis of electronic medical records from neurosurgery inpatients.

A series of studies have indicated that valproic acid (VPA) plasma concentration decreased rapidly when used concomitantly with carbapenem antibiotics, including meropenem (MEPM), imipenem and panipenem, which may increase the risk of seizure breakthrough. However, the cause for the change in VPA pharmacokinetics is unclear. A retrospective analysis of VPA therapeutic drug monitoring (TDM) records was performed to investigate this VPA pharmacokinetics drug-drug interaction. Three hundred and eighty one VPA TDM records from the Department of Neurosurgery of Xiangya Hospital from January 2012 to December 2014 were collected. The VPA TDM records were categorized by VPA and MEPM daily dosages in grams/day (g/day). A comparison of VPA plasma levels among different groups was performed to investigate the change in VPA level in this drug interaction. Remarkable decreases in VPA plasma level were observed when the drug was used concomitantly with MEPM in both 1.2 g/d and 1.6 g/d VPA groups (67·3 ± 4·6 μg/mL, n = 21 vs. 15·3 ± 1·9 μg/mL, n = 15, P < 0·001; 67·6 ± 1·2 μg/mL vs. 18·1 ± 2·6 μg/mL, n = 38, P < 0·001). No significant difference in VPA plasma concentrations was observed between the 1·2 g/day VPA + MEPM, 1·6 g/day VPA + MEPM and 2·0 g/day VPA + MEPM groups (15·3 ± 1·9 μg/mL, n = 15 vs. 18·1 ± 2·6 μg/mL, n = 38 vs. 9·0 ± 3·0 μg/mL, n = 7; P = 0·252). The decrease in VPA concentration was independent of MEPM daily dose (14·0 ± 5·1 μg/mL, n = 4 for high MEPM daily dose vs. 16·5 ± 1·9 μg/mL, n = 56 for low MEPM daily dose; P = 0·729). After discontinuation of MEPM for more than 7 days, VPA plasma concentration recovered to a value comparable to that before MPEM initiation (69·7 ± 4·2 μg/mL, n = 21 vs. 51·2 ± 8·1 μg/mL, n = 9; P = 0·48). This is the first study using a large number of VPA TDM records to investigate the change in VPA levels caused by concomitant use of MEPM. Our results imply that the decrease in drug concentration cannot be reversed by increasing VPA dose. Moreover, MEPM daily dose did not influence the drop in VPA plasma level. At least 7 days are required for the recovery of VPA plasma concentration after discontinuation of MEPM.

Plasma Free Amino Acid Profiles to Link Protein Malnutrition and Malnutrition Initiated Clinical Outcomes

In this mini-review, we focus on essential and semi-essential amino acid concentrations in plasma as potential biomarkers for clinical consequences related to protein malnutrition. In Japan, protein malnutrition is common across varying populations, especially in elderly adults and young women, which could cause increased risk of sarcopenia, heart failure, impaired immune response, and conditions specific to women. After establishing clinical reference intervals for plasma free amino acid concentrations, we have reported the clinical characteristics of a Japanese subpopulation with low plasma free essential and semi-essential amino acid concentrations (Low-EAA), which we hypothesized to be potential protein malnutrition. Intriguingly, the ratio of the subjects with Low-EAA was varied depending on age and gender, with elderly subjects and young women having higher ratio of subjects with Low-EAA. After adjusting for age, sex, and BMI, Low-EAA was significantly associated with surrogate markers of protein malnutrition, anemia, cardiovascular diseases and infectious diseases. Plasma free amino acid concentrations could be not only a potential biomarker, but also a predictor for health problems associated with malnutrition.

Modelling of atorvastatin pharmacokinetics and the identification of the effect of a BCRP polymorphism in the Japanese population.

Ethnicity plays a modulating role in atorvastatin pharmacokinetics (PK), with Asian patients reported to have higher exposure compared with Caucasians. Therefore, it is difficult to safely extrapolate atorvastatin PK data and models across ethnic groups. This work aims to develop a population PK model for atorvastatin and its pharmacologically active metabolites specifically for the Japanese population. Subsequently, it aimed to identify genetic polymorphisms affecting atorvastatin PK in this population. Atorvastatin acid (ATA) and ortho-hydroxy-atorvastatin acid (o-OH-ATA) plasma concentrations, clinical/demographic characteristics and genotypes for 18 (3, 3, 1, 1, 7, 2 and 1 in the ABCB1, ABCG2, CYP3A4, CYP3A5, SLCO1B1, SLCO2B1 and PPARA genes, respectively) genetic polymorphisms were collected from 27 Japanese individuals (taking 10 mg atorvastatin once daily) and analysed using a population PK modelling approach. The population PK model developed (one-compartment for ATA linked through metabolite formation to an additional compartment describing the disposition of o-OH-ATA) accurately described the observed data and the associated population variability. Our analysis suggested that patients carrying one variant allele for the rs2622604 polymorphism (ABCG2) show a 55% (95% confidence interval: 16-131%) increase in atorvastatin oral bioavailability relative to the value in individuals without the variant allele. The current work reports the identification in the Japanese population of a BCRP polymorphism, not previously associated with the PK of any statin, that markedly increases ATA and o-OH-ATA exposure. The model developed may be of clinical importance to guide dosing recommendations tailored specifically for the Japanese.

Comparative Bioavailability Study of Two 81 mg Coated Tablet Formulations of Acetylsalicylic Acid in Fasting Healthy Volunteers

Introduction: Low-dose acetylsalicylic acid is used as antithrombotic agent and the enteric-coated formulations are widely used to minimize the gastrointestinal side effects. Aim: To compare the bioavailability of two acetylsalicylic acid formulations (Ecasil-81®, 81 mg coated tablet) in fasting healthy volunteers. Methods: Healthy volunteers (n=16) were recruited to a monocentric, open label, randomized, two-way crossover pharmacokinetic study, with seven days washout period between the treatments. They received a single 81 mg oral dose of a test (new formulation) or a standard reference formulation of acetylsalicylic acid (Ecasil-81®) after about 8 h fasting. Blood samples were collected over a period of 36 h. The salicylic acid plasma concentration was evaluated by high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). Noncompartmental pharmacokinetic analysis was performed using the WinNonlin program. Results: The maximum plasma concentration (Cmax) of salicylic acid was 5433 and 5719 ng/mL reached in 3.66 and 4.02 h (tmax) for the test and the reference formulation, respectively. The 90% confidence interval of the ratios of geometric means of Cmax and area under curve of plasma concentration until the last concentration observed (AUC0- last) were within the interval 80-125%. Conclusion: The new acetylsalicylic acid formulation has a bioavailability equivalent to the reference formulation for the rate and the extent of absorption.

67 MATERNAL OBESITY AT CONCEPTION AND INSULIN SENSITIVITY IN LATE GESTATION ALTERS PLACENTAL STRUCTURE BUT NOT FETAL BIOMETRY AT BIRTH IN THE HORSE

Obesity is a major health issue in the horse industry, often associated with insulin resistance. This study aimed to analyse effects of maternal obesity at insemination and insulin resistance during late gestation on term placenta and foals at term. A total of 24 multiparous saddlebred mares were allocated to 1 of 2 groups at insemination: group obese (O) had a body condition score (BCS, French scale 1–5) &gt;4 (N = 15), and group normal (N) had a BCS = 4 (N = 9). From insemination until the sixth month of gestation, all the mares had access to pasture. From wintering, they were housed in box stalls and fed the same amount of energy, proteins, and fibre as a percentage of their body weight. During all the gestation, BCS, basal blood glucose, insulin, triglycerides, and nonesterified fatty acid plasma concentrations were measured each month. At 300 days of gestation, a frequent sampling glucose tolerance test, enabling the simultaneous evaluation of insulin sensitivity (IS) and glucose tolerance, was performed. At birth, placentas and foals were measured. Placentas were sampled around the umbilical cord to perform structural and functional analyses by stereology and RT-qPCR. Results were analysed using a type 3 ANOVA taking into account mare group and foal sex. Effects were considered significant when P &lt; 0.05. At 300 days of gestation, the frequent sampling glucose tolerance test indicated that half of the O mares were insulin resistant (IS &lt;1; N = 8), whereas the other half were insulin sensitive (IS &gt;1; N = 7). Based on these results, O mares were subdivided in 2 groups: obese resistant and obese sensitive (OS). Obese resistant mares were 61% less insulin sensitive than N mares and 59% less insulin sensitive than OS mares (P &lt; 0.0001, P &lt; 0.01, respectively). There was no difference for IS between N and OS mares. All analyses were thus performed comparing the 3 groups. In the N group, 3 mares were insulin resistant (one-third of the mares of the N group). Feed intake during wintering was not different between groups. Mares of both O groups maintained a high BCS (&gt;4) during pregnancy, whereas N mares lost BCS down 2.75 at birth (&lt;0.001). Basal glucose, insulin, triglycerides, and nonesterified fatty acid plasma were not different during gestation. At birth, no difference was observed for placental weight, surface and volume, nor for foal weight and withers height. The volume of allantoic vessels was reduced in placentas of OS mares compared with those of OR (P = 0.03; 78%) and N mares (P = 0.005; 65%). Moreover, placentas from OS mares had an increased volume of haemotrophic trophoblast (P = 0.03) and microcotyledonary vessels (P = 0.03) compared with N mares. No difference of expression was observed for 11 genes related to nutrient transfer, vascularization, growth, and development. Mare that are obese at insemination and insulin sensitive in late gestation appear to develop placental structural adaptations during gestation, possibly to increase fetoplacental exchanges, compared with obese, insulin resistant mares and lean mares. The monitoring of foal development (growth, metabolism, and osteoarticular status) is ongoing.

Effects of UGT1A6 and GABRA1 on Standardized Valproic Acid Plasma Concentrations and Treatment Effect in Children With Epilepsy in China.

Valproic acid (VPA) is a widely used antiepileptic drug with acceptable safety and efficacy in treating pediatric patients with various kinds of seizures. However, interindividual variations in plasma concentrations and treatment effects of patients with epilepsy treated with VPA are observed. This study aimed to evaluate the effects of various genetic variations on normalized plasma concentration of VPA (NCVPA) and the treatment response in Chinese children with epilepsy administered with VPA. Pediatric patients (3 months to 18 years old) with epilepsy, taking VPA therapy, were enrolled in the study. Important genetic variations of the pharmacokinetic and pharmacodynamic pathways of VPA were evaluated using the MassARRAY system (Sequenom). The associations of genetic variations with NCVPA/drug response and the mean value of NCVPA in responsive and resistant patients were evaluated using SPSS (17.0) and Plink (1.07) software. A total of 111 children with epilepsy (80 responsive and 31 resistant) were enrolled. rs28898617 (UGT1A6, A > G) was associated with an increase in NCVPA (β = 5.31, 95% confidence interval = 0.78-9.83, P = 0.024); therefore, patients with this variation need a lower dose of VPA. rs2279020 (GABRA1, G > A) was associated with a decreased risk of developing VPA-resistant epilepsy (odds ratio = 0.42, 95% confidence interval = 0.21-0.84, P = 0.014). Similar NCVPA was observed in resistant and responsive patients (P = 0.257). rs28898617 (UGT1A6, A > G) variation was associated with an increase in NCVPA. rs2279020 (GABRA1, G > A) variation was associated with a decreased risk of developing VPA-resistant epilepsy. Resistant and responsive patients to VPA treatment had a similar mean value of NCVPA. The findings may help clinicians to adjust the dose and predict treatment effect for children with epilepsy receiving VPA treatment.

Comparison of tranexamic acid plasma concentrations when administered via intraosseous and intravenous routes

IntroductionThere is a lack of information regarding intraosseous (IO) administration of tranexamic acid (TXA). Our hypothesis was that a single bolus IO injection of TXA will have a similar pharmacokinetic profile to TXA administered at the same dose IV. MethodsSixteen male Landrace cross swine (mean body weight 27.6±2.6kg) were divided into an IV group (n=8) and an IO group (n=8). Each animal received 30mg/kg TXA via an IV or IO catheter, respectively. Jugular blood samples were collected for pharmacokinetic analysis over a 3h period. The maximum TXA plasma concentration (Cmax) and corresponding time as well as distribution half-life, elimination half-life, area under the curve, plasma clearance and volume of distribution were calculated. One- and two-way analysis of variance for repeated measures (time, group) with Tukey's and Bonferonni post hoc tests were used to compare TXA plasma concentrations within and between groups, respectively. ResultsPlasma concentrations of TXA were significantly higher (p<0.0001) in the IV group during the TXA infusion. Cmax occurred at 4min after initiation of the bolus in the IV group (9.36±3.20ng/μl) and at 5min after initiation of the bolus in the IO group (4.46±0.49ng/μl). Plasma concentrations were very similar from the completion of injection onwards. There were no significant differences between the two administration routes for any other pharmacokinetic variables measured. ConclusionThe results of this study support pharmacokinetic bioequivalence of IO and IV administration of TXA.

Associations among plasma metabolite levels and short-term exposure to PM2.5 and ozone in a cardiac catheterization cohort

RationaleExposure to ambient particulate matter (PM) and ozone has been associated with cardiovascular disease (CVD). However, the mechanisms linking PM and ozone exposure to CVD remain poorly understood. ObjectiveThis study explored associations between short-term exposures to PM with a diameter <2.5μm (PM2.5) and ozone with plasma metabolite concentrations. Methods and resultsWe used cross-sectional data from a cardiac catheterization cohort at Duke University, North Carolina (NC), USA, accumulated between 2001 and 2007. Amino acids, acylcarnitines, ketones and total non-esterified fatty acid plasma concentrations were determined in fasting samples. Daily concentrations of PM2.5 and ozone were obtained from a Bayesian space-time hierarchical model, matched to each patient's residential address. Ten metabolites were selected for the analysis based on quality criteria and cluster analysis. Associations between metabolites and PM2.5 or ozone were analyzed using linear regression models adjusting for long-term trend and seasonality, calendar effects, meteorological parameters, and participant characteristics.We found delayed associations between PM2.5 or ozone and changes in metabolite levels of the glycine-ornithine-arginine metabolic axis and incomplete fatty acid oxidation associated with mitochondrial dysfunction. The strongest association was seen for an increase of 8.1μg/m3 in PM2.5 with a lag of one day and decreased mean glycine concentrations (−2.5% [95% confidence interval: −3.8%; −1.2%]). ConclusionsShort-term exposures to ambient PM2.5 and ozone is associated with changes in plasma concentrations of metabolites in a cohort of cardiac catheterization patients. Our findings might help to understand the link between air pollution and cardiovascular disease.

Hydroxytyrosol augments the redox status of high fat diet-fed rats

Hydroxytyrosol (HT) is being investigated for its manifold biological activities. In this study, we assessed whether HT could lessen the metabolic and redox imbalance caused by high-fat diet, in a rat model. Male Wistar rats were divided into four groups (n=4 each), homogeneous for age and weight. Group 1: control diet; Group 2: control diet+20μg HT/d by oral gavage; Group 3: high fat, high carbohydrate diet; Group 4: high fat, high carbohydrate diet +20μg HT/d by oral gavage. The experiment lasted four weeks. The addition of HT to the high fat diet did not slow down weight gain as compared to the unsupplemented diet. No significant differences in glycemia were observed among the four experimental groups. Ascorbic acid plasma concentrations at the end of the experimental period were non-significantly lower in high fat diet rats than in control animals. Plasma, but not erythrocytes hydroperoxide concentrations were significantly lower in group 4 animals as compared with the other ones. The high-fat diet induced protein carbonyl formation. Even though supplementation with HT lowered carbonyls’ concentrations, the effect did not reach statistical significance. Conversely, the action of HT became significant when plasma MDA was measured.HT also increased serum antioxidant capacity, assessed as ORAC of total serum and as conjugated diene formation of copper-oxidized isolated LDL/HDL.Public heath bodies should actively discourage the adoption of obesogenic high-fat diets, but HT as supplement modulates some of their harmful effects.

Alpha-Lipoic Acid Alleviates Acute Inflammation and Promotes Lipid Mobilization During the Inflammatory Response in White Adipose Tissue of Mice.

Recently, white adipose tissue has been shown to exhibit immunological activity, and may play an important role in host defense and protection against bacterial infection. Αlpha-lipoic acid (α-LA) has been demonstrated to function as an anti-inflammatory and anti-oxidant agent. However, its influence on the inflammatory response and metabolic changes in white adipose tissue remains unknown. We used male C57BL/6 mice as models to study the effect of α-LA on the inflammatory response and metabolic changes in white adipose tissue after stimulation with lipopolysaccharide (LPS). The non-esterified fatty acid content was measured by an automatic biochemical analyzer. The expression of inflammation-, lipid- and energy metabolism-related genes and proteins was determined by quantitative real-time polymerase chain reaction and western blotting. The results indicated that α-LA significantly decreased the epididymis fat weight index and the non-esterified fatty acid content in plasma compared with the control group. LPS significantly increased the expression of inflammation genes and α-LA reduced their expression. The LPS-induced expression of nuclear factor-κB protein was decreased by α-LA. Regarding lipid metabolism, α-LA significantly counteracted the inhibitory effects of LPS on the expression of hormone-sensitive lipase gene and protein. α-LA evidently increased the gene expression of fatty acid transport protein 1 and cluster of differentiation 36. Regarding energy metabolism, α-LA significantly increased the expression of most of mitochondrial DNA-encoded genes compared with the control and LPS group. Accordingly, α-LA can alleviate acute inflammatory response and this action may be related with the promotion of lipid mobilization in white adipose tissue.