Serum glycated albumin levels,but not glycated hemoglobin,is low in relation to glycemia in non-diabetic men with nonalcoholic fatty liver disease with high alanine aminotransferase levels

ObjectivesWe have reported that serum glycated albumin (GA) levels are low in obese subjects, smokers and hyperuricemic subjects in whom high sensitive CRP (hs-CRP) is elevated. Because patients with nonalcoholic fatty liver disease with high alanine aminotransferase (ALT) levels are reported to show high levels of hs-CRP, the relationship between serum ALT and serum GA levels was investigated.Design and methodsThis study comprised 196 non-diabetic men without drinking habit.ResultsCompared with the normal ALT group (serum ALT ≤ 30 U/L; n = 158), the high ALT group (serum ALT > 30 U/L; n = 38) had significantly higher fasting plasma glucose (PG), OGTT 2-h PG and HbA_1C levels. Meanwhile, serum GA was significantly lower, and hs-CRP was significantly higher in the high ALT group.ConclusionsThe results obtained indicate that serum GA is under a negative control of hs-CRP in subjects with high ALT without drinking habit.     

Serum 1,5-anhydroglucitol levels in patients with fulminant type 1 diabetes are lower than those in patients with type 2 diabetes

ObjectivesWe investigated clinical relevance of serum 1,5-anhydroglucitol (1,5-AG) levels in fulminant type 1 diabetes mellitus (FT1DM) patients, because 1,5-AG is known to reflect short term glycemic control.Design and methodsSubjects comprised 7 patients with FT1DM and 32 patients with type 2 diabetes mellitus (T2DM) with HbA1c < 8.5%. All of them have never been treated for diabetes.ResultsHbA_1C showed no significant difference between both groups. On the other hand, serum 1,5-AG levels were significantly lower in the FT1DM patients than in the T2DM patients. Serum 1,5-AG levels were < 5.0 μg/ml in 6 of 7 (86%) FT1DM patients, compared with only 1 of 32 (3%) T2DM patients.ConclusionsSerum 1,5-AG levels were lower in the FT1DM patients than in the T2DM patients. Serum 1,5-AG, but not HbA_1C, reflects short-term exacerbation of glycemia in patients with FT1DM.     

Revaluation of biological variation of glycated hemoglobin (HbA(1c)) using an accurately designed protocol and an assay traceable to the IFCC reference system

BackgroundGlycated hemoglobin (HbA_1c) has a key role for diagnosing diabetes and monitoring glycemic state. As recently reviewed, available data on HbA_1c biological variation show marked heterogeneity. Here we experimentally revaluated these data using a well designed protocol.MethodsWe took five EDTA whole blood specimens from 18 apparently healthy subjects on the same day, every two weeks for two months. Samples were stored at ? 80 °C until analysis and assayed in duplicate in a single run by Roche Tina-quant® Gen.2 immunoassay. Data were analyzed by the ANOVA. To assess the assay traceability to the IFCC reference method, we preliminarily carried out a correlation experiment.ResultsThe bias (mean ± SD) of the Roche immunoassay was 0.3% ± 0.7%, confirming the traceability of the employed assay. No difference was found in HbA_1c values between men and women. Within- and between-subject CV were 2.5% and 7.1%, respectively. Derived desirable analytical goals for imprecision, bias, and total error resulted 1.3%, 1.9%, and 3.9%, respectively. HbA_1c had marked individuality, limiting the use of population-based reference limits for test interpretation. The estimated critical difference was ~ 10%.ConclusionsFor the first time we defined biological variation and derived indices for the clinical application of HbA_1c measurements using an accurately designed protocol and an assay standardized according to the IFCC.     

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

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

β37Trp→Cys mutation leads to multiple new hemoglobin species in red cells

ObjectivesTo determine the cause of an unusual hemoglobin (Hb) pattern detected during HbA₁c monitoring.Design and methodHemolysate was analysed by ESI MS, and individual components purified by reverse phase HPLC. Peptide mapping was used to pinpoint the substitution and DNA sequencing to confirm the mutation.ResultsESI MS of lysate showed three novel β chains with mass changes of ? 83, ? 51 and + 222 Da. Peptide mapping and DNA sequencing indicated a β37Trp→Cys substitution. Reverse phase chromatography showed three new β globins eluting ahead of β^AConclusionThe new Hbs result from an initial β37Trp→Cys mutation (? 83 Da) followed by oxidation to cysteine sulfinic acid (+ 32 Da) and the formation of a glutathione adduct (+ 305 Da). Despite the hydrophobicity change and the critical location of the side chain on the α1β2 interface, there was no evidence of molecular instability or altered oxygen affinity, and no clear phenotype apart from discordant HbA₁c.     

The plasma levels of relaxin-2 and relaxin-3 in patients with diabetes

ObjectivesRelaxin-2 has been found to alleviate fibrosis in experimental diabetic cardiomyopathy. In addition, the levels of serum relaxin-3 were increased and correlated with all the component traits of metabolic syndrome. We investigated the levels of plasma relaxin-2 or relaxin-3 and their relationship to component traits in patients with diabetes.Design and methodsWe studied 33 newly diagnosed type 2 diabetes patients and 38 age-matched healthy subjects. Blood samples were taken at study entry, and relaxin-3, relaxin-2, fasting blood glucose, total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides, serum insulin and hemoglobin A_1c (HbA_1c) levels were measured.ResultsRelaxin-2 levels were significantly lower in patients with diabetes than in controls: the median plasma relaxin-2 concentration was 34.68 pg/mL (range, < 29.00–50.81 pg/mL) in patients with diabetes and 45.80 pg/mL (range, < 37.42–54.46 pg/mL) in controls (p = 0.0150). However, no differences in relaxin-3 levels were observed between the diabetes group and controls (p = 0.6550). The plasma levels of relaxin-2 or relaxin-3 were not correlated with systolic blood pressure (BP), diastolic BP, total cholesterol, LDL-C, HDL-C, triglyceride, fasting blood glucose, fasting insulin and HbA_1c in patients with diabetes. Additionally, there was no correlation between the plasma concentrations of relaxin-2 and relaxin-3 in patients with diabetes (r_s = 0.225; p = 0.208).ConclusionsWe conclude that the plasma levels of relaxin-2 in diabetes patients were lower than in controls, however, there are no difference in plasma relaxin-3 concentrations between controls and patients with diabetes. Relaxin-2 or relaxin-3 levels are not related to component traits in patients with diabetes.     

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

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

Improved measurement of LINE-1 sequence methylation for cancer detection

BackgroundMethylation of long interspersed nuclear element-1 (LINE-1) sequences varies among normal cells and it is often decreased in cancer genomes and white blood cells (WBC) of cancer patients. Current measurement techniques of genome-wide level are inadequate because LINE-1 methylation is distinctive at each locus. Here, we improved the detection of cancer by combining information of LINE-1 methylation pattern and level.MethodsCombined bisulfite restriction analysis (COBRA) of LINE-1, COBRA LINE-1, was used to test cancer cell lines, two oral rinse cohorts, and WBC from normal and cancer patients. COBRA LINE-1 separated LINE-1 sequences into 4 products depending on the methylation statuses of 2 CpG dinucleotides, as follows: 2 unmethylated CpGs (^uC^uC), partial methylation (^mC^uC), 1 methylated CpG (^mC), and 1 unmethylated CpG (^uC).ResultsThe association between ^mC^uC and ^uC^uC was directly correlated in normal cells (r = 0.4895, p = 0.0009) but inversely correlated in cancer (r = ? 0.8979, p = 0.0002). Oral rinse AUC values of ^uC^uC were 0.763 and 0.926 and methylation levels were 0.707 and 0.621, respectively. ^uC^uC, but not overall methylation level, differentiated cancer WBC from normal (p = 0.0082 and p = 0.4830, respectively).ConclusionLINE-1 partial methylation represents hypomethylation in normal cells but hypermethylation in cancer cells. This information improves LINE-1 methylation detection in cancer.     

Coenzyme Q10 levels are low and associated with increased mortality in post-cardiac arrest patients

AimSurvival after cardiac arrest (CA) is limited by the profound neurologic insult from ischemia–reperfusion injury. Therapeutic options are limited. Previous data suggest a benefit of coenzyme Q₁₀ (CoQ₁₀) in post-arrest patients. We hypothesized that plasma CoQ₁₀ levels would be low after CA and associated with poorer outcomes.MethodsProspective observational study of post-arrest patients presenting to a tertiary care center. CoQ₁₀ levels were drawn 24 h after return of spontaneous circulation (ROSC) and compared to healthy controls. Levels of inflammatory cytokines and biomarkers were analyzed. Primary endpoints were survival to discharge and neurologic status at time of discharge.Results23 CA subjects and 16 healthy controls were enrolled. CoQ₁₀ levels in CA patients (0.28 μmol L^?1, inter-quartile range (IQR): 0.22–0.39) were significantly lower than in controls (0.75 μmol L^?1, IQR: 0.61–1.08, p < 0.0001). The mean CoQ₁₀ level in CA patients who died was significantly lower than in those who survived (0.27 vs 0.47 μmol L^?1, p = 0.007). There was a significant difference in median CoQ₁₀ level between patients with a good vs poor neurological outcome (0.49 μmol L^?1, IQR: 0.30–0.67 vs 0.27 μmol L^?1, IQR: 0.21–0.30, p = 0.02). CoQ₁₀ was a statistically significant predictor of poor neurologic outcome (adjusted p = 0.02) and in-hospital mortality (adjusted p = 0.026).ConclusionCoQ₁₀ levels are low in human subjects with ROSC after cardiac arrest as compared to healthy controls. CoQ₁₀ levels were lower in those who died, as well as in those with a poor neurologic outcome.     

Platelet activation and vascular endothelial growth factor 165 release in hepatocellular cancer

BackgroundVascular endothelial growth factor (VEGF₁₆₅) is stored, transported and released by platelets. Platelet functional abnormalities have been described in patients with hepatocellular carcinoma (HCC). Thus, this study was designed to investigate the behavior of VEGF₁₆₅ with respect to platelet activation in HCC.MethodsPlasma and serum VEGF₁₆₅ and plasma sP-selectin levels were analyzed in patients with HCC (n = 70) or cirrhosis (n = 45) and control subjects (n = 70). Given the thrombocytopenia that characterizes both HCC and cirrhotic patients, plasma VEGF₁₆₅ and sP-selectin as well as serum VEGF (plt-VEGF₁₆₅-load) levels were normalized by platelet counts.ResultsMedian concentrations of plasma VEGF₁₆₅/platelet (p = 0.002) and sP-selectin/platelet (p < 0.0001) were higher in HCC or cirrhotic patients compared to controls. Moreover, sP-selectin/platelet was the only independent variable predictive of plasma VEGF₁₆₅/platelet at multivariate analysis (p < 0.0001). Conversely, plt-VEGF₁₆₅-load correlated with tumor diameter (p < 0.05) but not with sP-selectin/platelet and was an independent predictor for 5 year overall survival (p = 0.012).ConclusionsThe results obtained are suggestive for VEGF₁₆₅ release by tumor in HCC. It is plt-VEGF₁₆₅-load, but not plasma VEGF₁₆₅ or serum VEGF₁₆₅ that is an independent predictor for overall survival of HCC patients.     

Mitochondrial depolarisation and oxidative stress in rheumatoid arthritis patients

ObjectivesTo investigate mitochondrial membrane integrity, lipid peroxidation and cytotoxicity in peripheral lymphocytes (PL) from rheumatoid arthritis (RA) patients.Design and methodsSouth African black RA patients (HIV^?) were recruited into the study. Mitochondrial membrane potential (Δψ_m) was analysed in PL using the JC-1 dye distribution assay and flow cytometry. Correlations between Δψ_m and clinical parameters were tested for statistical significance. Cytotoxicity (LDH) and lipid peroxidation (thiobarbituric acid reactive substances (TBARS)) was also determined.ResultsOur findings show significantly elevated levels of cytotoxicity (p = 0.0029) and lipid peroxidation (p = 0.0030) in RA. A significantly higher percentage of circulating PL contained depolarised mitochondria (p = 0.0003) which correlated with disease activity and C-reactive protein levels in patients. Collapse of Δψ_m also negatively correlated to absolute lymphocyte counts (r = ? 0.4041; p = 0.0197).ConclusionThese findings suggest a possible role for mitochondrial membrane alterations in the pathology of RA.     

Positive correlation between CD137 expression and complex stenosis morphology in patients with acute coronary syndromes

BackgroundCD137, a member of the tumor necrosis factor receptor superfamily, has been reported to be expressed highly in patients with acute coronary syndromes. However, limited information is available on the relationship between CD137 expression and complex stenosis morphology in patients with acute coronary syndromes.MethodsOur study included normal controls (n = 50), patients with stable angina (SA) (n = 80) and patients with acute coronary syndromes (ACS), including unstable angina (UA) (n = 70) and acute myocardial infarction (AMI) (n = 100). The expression of CD137 in peripheral monocytes was analyzed by flow cytometry. Serum soluble CD137 (sCD137), MMP-9 and MMP-3 levels were measured by enzyme-linked immunosorbent assay kit. All coronary stenoses with ≥ 50% diameter reduction were assessed by angiographic coronary stenosis morphology.ResultsPatients with ACS(n = 170) showed a significant increase of CD137 [23.6 ± 5.7 mean fluorescence intensity (MFI)] expression in peripheral monocytes compared with control (8.4 ± 2.6 MFI) and SA group (7.9 ± 2.1 MFI) (p < 0.001). sCD137 also showed higher level in patients with ACS(30.2 ± 8.7 ng/ml) than in control (6.2 ± 1.8 ng/ml) and SA group (7.1 ± 2.1 ng/ml) (p < 0.001). Serum MMP-3 and MMP-9 in patients with ACS were 2-times greater than those in control and SA group. A positive correlation was found between MMP-9, MMP-3 and CD137 expression in peripheral monocytes as well as sCD137 levels. An obvious correlation was also observed between soluble or membrane-bound CD137 expression and complex coronary stenoses (r₁ = 0.5548, r₂ = 0.4652, and p < 0.001). In the logistic regression model, the independent predictors of ACS were sCD137 (odds ratio 2.671, 95% CI 1.718–4.153, P = 0.000), MMP-9 (1.431, 1.043–1.964, P = 0.026) and MMP-3 (1.368, 1.038–1.817, P = 0.018).ConclusionPatients with ACS showed significantly positive correlation between CD137 expression and complex coronary stenosis morphology. We speculate that the increased CD137 expression might represent or reflect an instability of atherosclerotic plaques in patients with ACS.     

Urinary 11-dehydro thromboxane B₂ levels in type 2 diabetic patients before and during aspirin intake

BackgroundDiabetic patients commonly present an increased risk for cardiovascular events, for which aspirin is the most frequently used medication for primary prevention. Urinary 11-dehydro thromboxane (11-dhTXB₂) concentrations assess the effect of aspirin on platelets and identify patients who are at risk of cardiovascular events. The present study investigated whether or not type 2 diabetic patients who took a daily dose of 100 mg of aspirin had a significant reduction in urinary 11-dhTXB₂ concentrations and whether these results were associated with clinical and laboratory variables.MethodsEighty-one type 2 diabetic patients were enrolled in the study. Laboratory tests included the determination of lipidic profile, glycated hemoglobin, platelets count, molecular analysis for both GPIIbIIIa and COX-1 polymorphisms, and urinary 11-dhTXB₂.ResultsPatients' median value for urinary 11-dhTXB₂ before aspirin intake was 179 pg/mg of creatinine. After 15 days taking aspirin, the patients presented median of 51 pg/mg of creatinine, thus revealing a significant difference between medians (p = 0.00). A reduction of 95% in urinary 11-dhTXB₂ concentrations could only be identified in 4 patients (5%). A BMI of ≥ 26 presented a significant association with a reduction of urinary 11-dhTXB₂ concentrations (p = 0.010), as shown by the multiple logistic regression model. Other clinical and laboratory variables showed no association.ConclusionsRegardless of the mechanisms related to aspirin non-responsiveness, most patients enrolled in the present study also presented a reduced or minimal response to low-dose aspirin therapy, thereby indicating a clear variability related to aspirin effectiveness. Moreover, BMI appears to be independently associated to the reduction of urinary 11-dhTXB₂ concentrations in type 2 diabetic patients taking aspirin.     

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

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

Evaluation of circulating vascular endothelial growth factor and soluble adhesion molecules as reliable predictors of native arteriovenous fistula thrombosis in chronic hemodialysis patients

ObjectivesWe evaluated the possibility of using circulating vascular endothelial growth factor (VEGF) and soluble adhesion molecules as reliable predictors of native arteriovenous (AV) fistula thrombosis in chronic hemodialysis (HD) patients.Design and methodsThis study included 62 HD patients (34 with thrombosed and 28 with non-thrombosed AV fistulas) and 21 healthy volunteers. Serum VEGF, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble E-selectin (sE-selectin) were measured using ELISA technique.ResultsVEGF, sVCAM-1, sICAM-1 and sE-selectin median levels were higher in HD patients compared to controls (p = 0.000 for all parameters). Increased median levels of VEGF and sVCAM-1 were demonstrated in HD patients with thrombosed AV fistulas compared to HD patients with non-thrombosed AV fistulas (p = 0.003 and 0.000, respectively). A significant positive correlation has been found between VEGF and sVCAM-1 in HD patients with thombosed AV fistulas (r = 0.525, p = 0.001).ConclusionsThe assessment of serum VEGF and sVCAM-1 might be useful for the identification of the chronic HD patients at an increased risk for native AV fistulas thrombosis. The clinical relevance of these observations warrants further investigations.     

Analysis of glucocerebrosidase activity in dry blood spots using tandem mass spectrometry

BackgroundGaucher disease (GD) is due to deficiency of acid-β-glucosidase (ABG) and comprises a clinical spectrum with variable age of onset and severity. We evaluated a tandem mass spectrometry (MS/MS) method to measure ABG activity for high through-put screening.MethodsABG activity was measured in 3.2 mm punches from dry blood spots (DBS). Each punch was incubated for 21 h with the substrate D-Glucosyl-β1-1′-N-dodecanoyl-D-erythro-sphingosine [C12-glucocerebroside (C₃₆H₆₉NO₈)] and internal standard N-myristoyl-D-erythro-sphingosine [C14-ceramide (C₃₂H₆₃NO₃)]. The product and internal standard were quantified using MS/MS.ResultsABG activities in anonymized newborn screening samples from NY State were (mean) 22.0 μmol/h/L ± (SD) 13.8 μmol/h/L (n = 2088, median 19.9 μmol/h/L, 95%CI 22.59–21.41 μmol/h/L). The enzymatic activity in DBS from 10 treatment naïve adult Gaucher patients was less than 4.2 μmol/h/L. ABG activity was stable for 3 months at room temperature a 20% activity reduction was observed. Inter- and intra-run imprecisions were 8% and 13.7%, respectively. The limit of detection was 0.75 μmol/h/L and limit of quantification was 1.25 μmol/h/L.ConclusionsThe measurement of ABG activities in DBS using MS/MS is suitable for high-throughput analysis of at-risk individuals and potentially for newborn screening for GD.     

Population pharmacokinetics of oral levofloxacin 500 mg once-daily dosage in community-acquired lower respiratory tract infections: results of a prospective multicenter study in China

This study aimed to explore the pharmacokinetic features of levofloxacin (LVFX) in Chinese patients with infections and to confirm oral LVFX 500 mg once daily as an optimal treatment regimen based on pharmacokinetic-pharmacodynamic (PK-PD) analysis. A total of 1052 plasma samples from 164 Chinese adult patients with communityacquired lower respiratory tract infections (CALRTIs) and 18 healthy volunteers were used for population PK analysis. LVFX 500-mg tablets were given once daily. A nonlinear mixed effects model (NONMEM) program was used for population PK model-building and a two-compartment model with first-order absorption process was established. Creatinine clearance (CL_cr) and body weight were identified as intrinsic factors which significantly affected oral clearance (CL_t/F) and the apparent volume of distribution of the central compartment (V1/F), respectively. The final model is described as follows: CL_t/F (l/h) = (8.97 + 0.917 × (CL_cr (ml/min) ? 100.92) × 60/1000) × exp (η_CLt/F). V1/F (l) = (85.3 + 1.22 × (weight (kg) ? 60.75)) × exp (η_V1/F). Q/F (l/h) = 0.351. V2/F (l) = 6.81. k_a (h^?1) = 1.44 × exp(η_ka). Based on the population PK model, mean C_max and AUC_0–24h in CALRTI patients were estimated as 5.13 µg/ml and 58.98 µg·h/ml, respectively. A subgroup analysis showed that patients with mild renal dysfunction (50 ml/min ≤ CL_cr < 80 ml/min) had 34% higher AUC_0–24h values compared to patients with normal renal function (CL_cr ≥ 80 ml/min). Postmodeling simulation using final population PK estimates also showed that C_max and AUC_0–24h increased markedly in patients with severe renal dysfunction. The results indicate that LVFX dosage adjustment should be individualized on the basis of the CL_cr, especially in those with CL_cr less than 50 ml/min. None of the PK parameters had any correlation with the occurrence of adverse events. PK-PD analysis indicated that, in patients treated with LVFX 500 mg once daily, the AUC_0–24h/MIC ratio exceeded the target for those major CALRTI pathogens isolated. In addition, the C_max/MIC ratio reached 5 for Streptococcus pneumoniae, indicating that the emergence of LVFX-resistant S. pneumoniae could be prevented during the therapy with this dosage regimen. These results demonstrate that oral LVFX 500 mg once daily has favorable PK parameters and PK-PD features in patients with CALRTIs, and the results strongly support this dosage regimen for the treatment of CALRTI.     

Hemoglobin Seville [α2 β2 81(EF5) Leu→Phe] a silent phenotypic variant that interferes in hemoglobin A1c measurement by ion-exchange HPLC method

ObjectivesThe aim of the study was to investigate hemoglobin (Hb) species in a 61 year-old male with diabetes mellitus type II and a low value of Hb A_1c.Design and methodsHb species were analyzed by electrophoresis and chromatography methods. Functional properties were determined by oxygen equilibrium studies. β-globin gene was amplified by PCR and sequenced.Results and conclusionsA novel clinically silent Hb (Hb Seville), that results in falsely low Hb A_1c measurement, was detected. This Hb variant presented a single base mutation at codon 81 (C → T) of the β-globin gene. This case points out the necessity of careful inspection of the chromatograms and the use of additional methods to Hb A_1c measurement when the presence of aberrant peaks is detected.     

Analysis of glucagon-like peptide 1; what to measure?

BackgroundGlucagon-like peptide 1 (GLP-1) is a gut hormone which acts as an incretin and is therefore of major interest in treatment of type II diabetes mellitus. GLP-1 circulates in many different forms, some of which are biologically active and others are not. Our hypothesis was that various methods to measure GLP-1 detect different forms of GLP-1, which may cause confusion when comparing results.MethodsWe compared three assays, the GLP-1 (active) ELISA (Linco research; ELISA_LINCO), GLP-1 (total) RIA (Linco research; RIA_LINCO) and the total GLP-1 RIA developed by the group of Holst (RIA_HOLST) on specimens obtained during meal studies. In addition, we studied the effect of addition of a DPP-4 inhibitor.ResultsThe correlation between RIA_LINCO and ELISA_LINCO was highest (r = 0.76; n = 35; p < 0.01), whereas results of RIA_HOLST correlated less with those of RIA_LINCO and ELISA_LINCO (r = 0.35 and 0.39 respectively; n = 35; p < 0.05). GLP-1 results measured with ELISA_LINCO were higher (median 28%; p < 0.001) upon addition of the DPP-4 inhibitor.ConclusionTwo commercially available GLP-1 assays do not necessarily give results equal to the well-defined GLP-1 assay developed in Copenhagen. Absolute values are also different due to differences in standardisation. Moreover, assays detect different forms of GLP-1, which hampers comparison to published data.     

Lymphocytic enzymes and lipid peroxidation in patients with metabolic syndrome

ObjectivesMetabolic syndrome (MetS) is considered a state of chronic inflammation. This study aimed to ascertain selected parameters of purinergic and cholinergic systems related to glucose metabolism and inflammation, as well as _γ-glutamyltransferase (GGT) and N-acetyl-b-glucosaminidase (NAG) activities and lipoperoxidation in lymphocytes of patients with MetS.Design and methodsThe adenosine deaminase (ADA), dipeptidyl peptidase IV (DPP-IV), acetylcholinesterase (AChE), GGT and NAG activities, as well as thiobarbituric acid reactive substances (TBARS) levels were investigated in lymphocytes of patients with MetS (n = 38) and healthy volunteers (n = 41). We also evaluated the insulin levels, anthropometric measurements and routine biochemical analyses.ResultsADA (p < 0.05), DPP-IV and AChE (p < 0.0001) activities were higher in patients with MetS when compared to the control group. Furthermore, we observed correlations between ADA and DPP-IV activities (p = 0.0002; r = 0.5945), TBARS levels and ADA (p = 0.0021; r = 0.5172) and DPP-IV activities (p = 0.0022; r = 0.5010).ConclusionsOur findings showed that MetS might cause tissue distress that disturbed lymphocytic ADA, DPP-IV and AChE activities in response to inflammatory stimuli. These alterations evidence clinical abnormalities, since these enzymatic systems are able to regulate several aspects of adipose tissue function and inflammatory state of MetS and could be used successfully both for preventing and for halting the progression of MetS.