SD Plasma Research Articles

Plasma Concentrations of Fluconazole After a Single Oral Dose and Administration in Drinking Water in Cockatiels (Nymphicus hollandicus)

Candidiasis frequently affects the oropharynx, esophagus, and crop of juvenile birds with immature immune systems and adult birds that have received long-term antibiotic treatment. Fluconazole is used extensively in human medicine to treat mucosal and invasive candidiasis and has been used in birds; however, there have been few pharmacokinetic studies in avian species to guide safe and effective treatment. The purpose of the present study was to investigate the disposition of fluconazole in cockatiels (Nymphicus hollandicus) after single oral dose administration and to determine if therapeutic plasma concentrations could be safely achieved by providing medicated water. Twenty-eight cockatiels were placed into 7 groups and were orally administered a 10 mg/kg fluconazole suspension. Blood samples were collected from each group for plasma fluconazole assay at serial time points. Fluconazole-medicated drinking water was prepared daily and offered to 15 cockatiels at a concentration of 100 mg/L for 8 days. Blood was collected for plasma fluconazole assay at 2 time points on days 3 and 7. When using naive averaged data in the single-dose study, pharmacokinetic parameters were similar for both compartmental and noncompartmental analyses. The elimination half-life of fluconazole was 19.01 hours, maximum plasma concentration was 4.94 microg/mL, time until maximal concentration was 3.42 hours, and the area under the plasma concentration versus time curve (AUC) was 149.28 h x microg/mL. Computer-simulated trough and peak plasma concentrations at steady-state after multiple doses of fluconazole at 10 mg/kg every 24 hours, 10 mg/kg every 48 hours, and 5 mg/kg every 24 hours were approximately 4.1-8.5 microg/mL, 1.2-6.0 microg/mL, and 2.0-4.3 microg/mL, respectively. Mean +/- SD plasma fluconazole concentrations for the 100 mg/L medicated water study at 0800 and 1600 hours on day 3 were 3.69 +/- 1.22 microg/mL (range, 1.73-5.26 microg/mL) and 4.17 +/- 1.96 microg/mL (range, 3.58-7.49 microg/mL), respectively, and at 0800 and 1600 hours on day 7 were 4.78 +/- 0.91 microg/mL (range, 2.62-6.11 microg/mL) and 6.61 +/- 1.67 microg/mL (range, 3.76-8.78 microg/ mL), respectively. Treatment with fluconazole administered orally at a dosage of 5 mg/kg once daily or 10 mg/kg every 48 hours or fluconazole administered in the drinking water at a concentration of 100 mg/L is predicted to maintain plasma concentrations in most cockatiels that exceed the minimum inhibitory concentration of 90% or therapeutic AUC:MIC of most strains of Candida albicans (by using susceptibility data from humans). The compounded oral suspension was stable for 14 days when stored at 5 degrees C (41 degree sF) and protected from light.

Effect of hemodialysis on total antioxidant status of chronic renal failure patients in government hospitals in Lagos Nigeria

Renal failure is accompanied by oxidative stress, which is caused by enhanced production of reactive oxygen species and impaired antioxidant defense. To assess the effect of hemodialysis (by cellulose membrane dialyzer) on plasma total antioxidant status and lipid peroxidation of patients in chronic renal failure before and after dialysis. The finding would serve as guide to administration or otherwise of supplementary therapeutic antioxidant before or after hemodialysis. Also, it will assist in the choice of antioxidant impregnated over the conventional non-impregnated dialyzer membrane. Twenty-five patients (14 men and 11 women, aged 24-75 years; median 61) with end-stage renal failure who were undergoing hemodialysis for the first time were recruited. Plasma level of potassium (K+), sodium (Na+), blood urea nitrogen (BUN), creatinine, total antioxidant status (TAS), and lipid peroxidation (MDA) were measured, before and after hemodialysis. The mean ± SD of plasma level of TAS (1.10 ± 0.3 mmol/L trolox Eq) for males and (1.09 ± 0.2 mmol/L trolox Eq) for females postdialysis were significantly reduced ( P < 0.05) in comparison with (1.72 ± 0.4 mmol/L trolox Eq) for males and (1.83 ± 0.7 mmol/L trolox Eq) for females predialysis, respectively. However, the mean ± SD plasma level of MDA (6.03 ± 0.4 nmol/ml) for males and (6.71 ± 0.7 nmol/ml) for females were significantly increased postdialysis ( P < 0.01) compared to predialysis (3.98 ± 0.8 nmol/ml) for males and (4.05 ± 0.9 nmol/ml) for females, respectively. Based on the outcome of this study, it is suggested that antioxidant-impregnated dialysis membranes and/or exogenous supplementary antioxidant would be beneficial to patients with chronic renal failure. Removal of reactive oxygen species could improve the health and general quality of life of uremic patients.

Steady-State Pharmacokinetics and BAL Concentration of Colistin in Critically Ill Patients After IV Colistin Methanesulfonate Administration

Infections caused by multidrug-resistant gram-negative bacteria have caused a resurgence of interest in colistin. To date, information about pharmacokinetics of colistin is very limited in critically ill patients, and no attempts have been made to evaluate its concentration in BAL. In this prospective, open-label study, 13 adult patients with ventilator-associated pneumonia caused by gram-negative bacteria were treated with colistin methanesulfonate (CMS) IV, 2 million International Units (174 mg) q8h, a usually recommended dose, for at least 2 days. Blood samples were collected from each patient at time intervals after the end of infusion. BAL was performed at 2 h. Colistin was measured by a selective, sensitive high-performance liquid chromatography-based method. Pharmacokinetic parameters were determined by noncompartmental analysis. Patients received 2.19 ± 0.38 mg/kg (range, 1.58-3.16) of CMS per dose. At steady state, mean ± SD plasma colistin maximum (Cmax) and trough (Ctrough) concentrations were 2.21 ± 1.08 and 1.03 ± 0.69 μg/mL, respectively. Mean ± SD area under the plasma concentration-time curve from 0 to 8 h (AUC(0-8)), apparent elimination half-life, and apparent volume of distribution were 11.5 ± 6.2 μg × h/mL, 5.9 ± 2.6 h, and 1.5 ± 1.1 L/kg, respectively. Cmax/minimum inhibitory concentration (MIC) ratio and AUC(0-24)/MIC ratio (MIC = 2 μg/mL) were 1.1 ± 0.5 and 17.3 ± 9.3, respectively. Colistin was undetectable in BAL. Nephrotoxicity was not observed. Although the pharmacodynamic parameters that better predict the efficacy of colistin are not known in humans, in critically ill adult patients the IV administration of CMS 2 million International Units (174 mg) q8h results in apparently suboptimal plasma concentrations of colistin, which is undetectable in BAL. A better understanding of the pharmacokinetic-pharmacodynamic relationship of colistin is urgently needed to determine the optimal dosing regimen.

Membrane Associated TGF-β1 on Leukemia Blast-Derived Microvesicles In Sera of Acute Myeloid Leukemia Patients Suppresses NK Cell Function

AbstractAbstract 502Natural killer (NK) cell cytotoxicity in patients with acute myeloid leukemia (AML) is significantly decreased relative to that in normal controls (NC). TGF-β1 is a potent inhibitor of NK cell cytotoxicity. We considered the possibility that suppression of NK cell activity in AML patients is mediated by leukemia blast-derived microvesicles (MV) via TGF-β1. Sera of 19 patients newly diagnosed with AML prior to any treatment were used to isolate MV by ultracentrifugation. MV from AML patients were positive for the blast-associated markers (CD33, CD34, CD117) by flow cytometry and for membrane-associated TGFb-1 in Western blots, whereas neither these markers nor TGFb-1 were detected in MV from NC. The protein content of blast-derived MV was higher (p<0.001) than that of MV isolated from sera of 25 NC (75μ g±12/mL vs 1.2μ g±0.4/mL). To evaluate MV-mediated NK cell suppression, NK cells obtained from NC were co-incubated with MV isolated from patients' sera. A significant decrease (p<0.002) in NK cell cytotoxicity (2412 LU pre- vs 1640 LU post co-incubation) was accompanied by a concomitant decrease (p<0.004) in the NK-cell activating receptor, NKG2DR, expression levels. To determine whether MV-associated TGF-β1 was responsible for these adverse effects of MV on NK cells, neutralizing anti-TGF-β1 mAb was added to the co-cultures. This mAb significantly abrogated MV-mediated inhibition of NK cell cytotoxicity and down-regulation of the NKG2DR expression level. We next measured the plasma concentrations of TGF-β1 in AML patients and NC. The mean ± SD plasma concentration of TGF-β1 was 2,600 pg/mL ± 2,500 in patients vs. 101 pg/mL ± 55 in NC (p<0.0001). The use of urea, which disassociated membrane-bound TGF-β1 in MV, resulted in a significant increase of the measured TGF-β1 levels (mean 13,700 pg/mL ± 9,800) only in the sera of AML patients but not in the sera of NC. To determine whether the SMAD pathway used by the TGF-β family members is involved in the MV-NK cell interactions, we co-incubated NK cells with MV isolated from sera of AML patients. These MV induced SMAD phosphorylation in NK cells. The addition of anti-TGF-β1 mAbs to the co-culture inhibited SMAD phosphorylation but did not alter expression of the SMAD protein itself. These data provide evidence for a novel mechanism responsible for down-regulation of NK cell activity and NKG2DR expression levels by TGF-β1 associated with leukemia blast-derived MV in AML patients. Disclosures:No relevant conflicts of interest to declare.

Neutrophil Gelatinase-Associated Lipocalin: A Biomarker in COPD

<h3>Background</h3> Neutrophil gelatinase-associated lipocalin (NGAL) is an antimicrobial peptide that could be involved in the pathogenesis of COPD. This study aimed to measure the plasma levels of NGAL in a large cohort of patients with COPD and control subjects and examine the levels of NGAL by COPD characteristics. <h3>Methods</h3> The study included 402 patients with COPD and 229 control subjects aged 40 to 76 years from the Bergen COPD Cohort Study. All patients with COPD had an FEV₁/FVC ratio of < 0.7, an FEV₁ < 80% predicted, and a smoking history of ≥ 10 pack-years. Plasma levels of NGAL were determined by enzyme immunoassay. Linear regression models were fitted with NGAL as the outcome variable. Confounders examined were sex, age, smoking, Charlson comorbidity score, use of inhaled steroids, neutrophil cell count, plasma creatinine and ferritin, and C-reactive protein. <h3>Results</h3> Mean ± SD plasma concentrations of NGAL were 75.1 ± 31.8 ng/mL in patients with COPD and 56.5 ± 22.0 ng/mL in control subjects (<i>P</i> < .01). NGAL levels were bivariately associated with age, smoking, body composition, Charlson comorbidity score, neutrophil blood count, creatinine, and C-reactive protein but were significantly elevated in patients with COPD, even after adjustment for confounders. Frequent exacerbations and hypoxemia was associated with higher levels of NGAL, whereas increasing Global Initiative for Chronic Obstructive Lung Disease stage was associated with lower levels of NGAL among patients with COPD. <h3>Conclusions</h3> Plasma levels of NGAL were significantly higher in patients with COPD compared with control subjects. NGAL was related to important COPD characteristics.

The relationship between plasma angiopoietin-like protein 4 levels, angiopoietin-like protein 4 genotype, and coronary heart disease risk.

To investigate the relationship between angiopoietin-like protein 4 (Angptl4) levels, coronary heart disease (CHD) biomarkers, and ANGPTL4 variants. Plasma Angptl4 was quantified in 666 subjects of the Northwick Park Heart Study II using a validated ELISA. Seven ANGPTL4 single-nucleotide polymorphisms were genotyped, and CHD biomarkers were assessed in the whole cohort (N=2775). Weighted mean±SD plasma Angptl4 levels were 10.0±11.0 ng/mL. Plasma Angptl4 concentration correlated positively with age (r=0.15, P<0.001) and body fat mass (r=0.19, P=0.003) but negatively with plasma high-density lipoprotein cholesterol (r=-0.13, P=0.01). No correlation with triglycerides (TGs) was observed. T266M was independently associated with plasma Angptl4 levels (P<0.001) but was not associated with TGs or CHD risk in the meta-analysis of 5 studies (4061 cases/15 395 controls). E40K showed no independent association with plasma Angptl4 levels. In human embryonic kidney 293 and human hepatoma 7 cells compared with wild type, E40K and T266M showed significantly altered synthesis and secretion, respectively. Circulating Angptl4 levels may not influence TG levels or CHD risk for the following reasons: (1) Angptl4 levels were not correlated with TGs; (2) T266M, although associated with Angptl4 levels, showed no association with plasma TGs; and (3) TG-lowering E40K did not influence Angptl4 levels. These results provide new insights into the role of Angptl4 in TG metabolism.

Single‐Dose Pharmacokinetics and Tolerability of Telavancin in Elderly Men and Women

To assess the safety and tolerability, and the effect of sex on the pharmacokinetic disposition, of a single intravenous dose of telavancin 10 mg/kg in elderly (> or = 65 yrs) subjects. Phase I, open-label, single-dose, sex-stratified study. Clinical research unit. Eight healthy men and eight healthy women (mean +/- SD ages 70.6 +/- 6.1 and 70.8 +/- 5.5 yrs, respectively). Each subject received a 60-minute intravenous infusion of telavancin 10 mg/kg. For the pharmacokinetic analysis, blood samples were collected before drug administration and at regular intervals up to 48 hours after the start of the infusion. Telavancin plasma concentrations were determined by liquid chromatography with tandem mass spectrometric detection. Pharmacokinetic parameters of telavancin were determined by noncompartmental analysis. Standard clinical laboratory tests and electrocardiograms were used to assess safety and tolerability. The telavancin plasma concentration-time curves and pharmacokinetic parameters for both sexes were comparable. Pooled mean +/- SD clearance, half-life, and volume of distribution at the steady state were 12.2 +/- 1.4 ml/hour/kg, 9.3 +/- 1.3 hours, and 156 +/- 12 ml/kg, respectively. The pooled mean +/- SD plasma concentration of telavancin 24 hours postdose was 10.8 +/- 1.6 microg/ml, exceeding the telavancin minimum inhibitory concentration required to inhibit the growth of 90% of organisms for key gram-positive pathogens (0.5 microg/ml). Ten (63%) of the 16 subjects reported at least one adverse event, most of which were mild; no serious adverse events were noted in this study. No clinically significant changes in vital signs, physical examinations, electrocardiograms, or clinical biochemistry profiles were observed. The pharmacokinetic parameters of telavancin were similar between elderly men and women and comparable to historical results in healthy young subjects. No evidence was found to support telavancin dosage adjustment based on age or sex.

Aqueous humor and plasma concentrations of ciprofloxacin and moxifloxacin following topical ocular administration in ophthalmologically normal horses

To determine the degree of ocular penetration and systemic absorption of commercially available topical ophthalmic solutions of 0.3% ciprofloxacin and 0.5% moxifloxacin following repeated topical ocular administration in ophthalmologically normal horses. 7 healthy adult horses with clinically normal eyes as evaluated prior to each treatment. 6 horses were used for assessment of each antimicrobial, and 1 eye of each horse was treated with topically administered 0.3% ciprofloxacin or 0.5% moxifloxacin (n = 6 eyes/drug) every 4 hours for 7 doses. Anterior chamber paracentesis was performed 1 hour after the final dose was administered, and blood samples were collected at 24 (immediately after the final dose), 24.25, 24.5, and 25 hours (time of aqueous humor [AH] collection). Plasma and AH concentrations of ciprofloxacin or moxifloxacin were determined by use of high-performance liquid chromatography. Mean +/- SD AH concentrations of ciprofloxacin and moxifloxacin were 0.009 +/- 0.008 microg/mL and 0.071 +/- 0.029 microg/mL, respectively. The AH moxifloxacin concentrations were significantly greater than those of ciprofloxacin. Mean +/- SD plasma concentrations of ciprofloxacin were less than the lower limit of quantification. Moxifloxacin was detected in the plasma of all horses at all sample collection times, with a peak value of 0.015 microg/mL at 24 and 24.25 hours, decreasing to < 0.004 microg/mL at 25 hours. Moxifloxacin was better able to penetrate healthy equine corneas and reach measurable AH concentrations than was ciprofloxacin, suggesting moxifloxacin might be of greater value in the treatment of deep corneal or intraocular bacterial infections caused by susceptible organisms. Topical administration of moxifloxacin also resulted in detectable plasma concentrations.

Folate deficiency in women of reproductive age in nine administrative regions of Ethiopia: an emerging public health problem

Objective: To investigate the country-wide extent of folate deficiency and risk factors in Ethiopian women.Design: Cross-sectional study.Methods: Multistage cluster sampling and systematic sampling were used to select 970 women aged 15 to 49 years from nine accessible regions of Ethiopia. Demographic and health information was collected via questionnaire. Biological samples were collected by medical technologists. Outcome measures: demographic and health variables, food frequency, haemoglobin status, ferritin status and folate status.Results: Mean ± SD plasma folate was 5.57 ± 3.84 ng/mL. Forty-six per cent of women had severe folate deficiency (≤ 4 ng/mL) and 21.2% had marginal folate deficiency (> 4–6.6 ng/mL) with unequal prevalence across the country. Severe folate deficiency was higher in women who were unmarried (p = 0.002), had parity of 4–6 (p = 0.001), used oral contraceptives (p = 0.01), had no illnesses (p = 0.001), had intestinal parasites (0.001), followed lower plant food diets (0.001), followed lower animal product diets (0.001), had no anaemia (0.001) and had no iron deficiency (0.001). In logistic regression analysis, only low plant food diets (p = 0.001) and iron deficiency (p < 0.001) retained their significance with regard to folate deficiency. The odds for developing folate deficiency was 0.9 times less likely among those with higher plant food intake (AOR-0.9;95%CI – 0.72–1.2) and 0.2 times less likely among those with adequate iron (AOR-0.2;95%CI – 0.17–0.34).Conclusions: Folate deficiency is widespread in Ethiopian women, emphasising the need for sustainable folate intake through dietary diversification and appropriate public health measures.

Association of Plasma Sphingomyelin Levels and Incident Coronary Heart Disease Events in an Adult Population

A high plasma sphingomyelin level has been associated with subclinical atherosclerosis, coronary artery disease, and worse prognosis in subjects with acute coronary syndromes. We wanted to assess the predictive value of plasma sphingomyelin levels for incident coronary heart disease (CHD) events in the Multi-Ethnic Study of Atherosclerosis. The plasma sphingomyelin level was measured in 6809 of 6814 subjects (age, mean+/-SD, 62.2+/-10.2 years) participating in the Multi-Ethnic Study of Atherosclerosis, a population-based cohort study of adults free of clinical cardiovascular disease at baseline recruited at 6 clinic sites in the United States. The subjects consisted of 52.8% females, 38.5% whites, 11.8% Chinese, 27.8% blacks, and 21.9% Hispanics. Cox proportional hazard analysis was used to examine the association between plasma sphingomyelin level and 5 years of adjudicated incident CHD events, including myocardial infarction, resuscitated cardiac arrest, angina, CHD-related death, and revascularization (coronary artery bypass grafting or percutaneous transluminal coronary angioplasty). The mean+/-SD plasma sphingomyelin level was 48.0+/-16.0 mg/dL. A total of 189 subjects had an adjudicated CHD event during the 5 years of follow-up. In the Kaplan-Meier analysis, subjects with a plasma sphingomyelin level higher than the sex-specific median had a similar event-free survival rate compared with subjects with a plasma sphingomyelin level at or less than the sex-specific median (97.16% versus 97.00%; log rank P=0.71). In the univariate Cox proportional hazard analysis, the plasma sphingomyelin level was not a predictor of an incident CHD event (hazard ratio, 0.992 [0.982-1.004]; P=0.09). In our multistage multivariate Cox proportional hazard models, a higher plasma sphingomyelin level had a modest negative association with incident CHD events when total cholesterol, high-density lipoprotein, and triglycerides were included in the model (hazard ratio, 0.985 [0.973-0.996]; P=0.008) and also in our full model after adjusting for age, sex, total cholesterol, high-density lipoprotein, triglycerides, diabetes mellitus, cigarette smoking, systolic and diastolic blood pressure, medication use for blood pressure, and 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor use (hazard ratio, 0.984 [0.973-0.996]; P=0.002). In other models, the plasma sphingomyelin level was not associated with incident CHD events. A high plasma sphingomyelin level is not associated with an increased risk of incident CHD in population-based adults free of clinical cardiovascular disease at baseline.

Plasma Lipid Peroxidation and Total Antioxidant Status among Dyslipidaemic and Hypertensive Nigerians with High Risk of Coronary Heart Disease

The oxidative modification hypothesis of atherosclerosis predicts that low density lipoprotein-cholesterol (LDL-C) oxidation is an early event in atherosclerosis and that oxidized LDL-C contributes to atherogenesis To determine a link, if any, between the plasma lipid peroxidation and total antioxidant status (TAS) among dyslipidemic and hypertensive Nigerian patients with high risk of coronary heart disease. The study groups comprised 58 hypertensive adult Nigerians whose fasting plasma total cholesterol (TC) levels were > 5.5 mmol/L and with high risk coronary heart disease (CHD) lipid fraction i.e. 'the ratio of high density lipoprotein cholesterol to total cholesterol' (HDL-C/TC) < 0.13 were selected for the study. The control groups comprised 58 non hypertensive adult Nigerians with (HDL-C/TC) > 0.30. The mean +/- SD TAS level (1.02 +/- 0.15 mmol/L trolox) for males and (0.99 +/- 0.17 mmol/L) for females were significantly reduced (p < 0.05) compared to the controls; however (MDA) level (5.15 +/- 0.82 mmol/ml) for males and (5.06 +/- 0.73 mmol/ml) for females were significantly increased (p < 0.01) compared to the controls. The mean +/- SD plasma TC and LDL-C malonyl level (5.87 +/- 0.23 mmol/L and 4.65 +/- 0.34 mmol/L) were significantly increased (p < 0.01) in males hypertensive compared to the control. An inverse correlation between the TAS/TC(r = -0.53, p < 0.001) and TAS/LDL-C (r = -0.50, p < 0.001), however a direct correlation between the MDA/TC(r = 0.51, p < 0.001) and MDA/LDL-C (r = 0.48, p < 0.01) for males hypertensive were found. In female subjects the mean +/- SD plasma TC (5.95 +/- 0.13 mmol/L) and LDL-C (4.45 +/- 1.04 mmol/L) were significantly increased (p < 0.05) and (p < 0.01) respectively compared to the controls. Also in hypertensive females inverse correlation between the TAS/TC (r = -0.59, p < 0.001) and TAS/LDL-C (r = -.41, p < 0.01), and a direct correlation between the MDA/TC ( r= .48, p < 0.01) and MDA/LDL-C (r = 0.31, p < 0.05) were found. Since dyslipidaemia, hypertension and lipid peroxidation were directly relate to the severity of atherosclerosis, elimination of free radicals in the plasma before the peripheral tissues can take them up might reduce atherosclerosis. In view of our present findings, a management strategy aimed at simultaneously reducing lipid peroxidation and increasing total antioxidant status in dyslipidemic patients may be of benefit.

Plasma lactate concentrations in free-ranging moose (Alces alces) immobilized with etorphine

ObjectiveTo investigate plasma lactate concentrations of etorphine-immobilized moose in relation to environmental, temporal and physiological parameters. Study designProspective clinical study. AnimalsFourteen female and five male moose (Alces alces), estimated age range 1–7 years. MethodsThe moose were darted from a helicopter with 7.5 mg etorphine per animal using projectile syringes and a dart gun. Once immobilized, the moose were approached, a venous blood sample was obtained and vital signs including pulse oximetry were recorded. Diprenorphine was administered to reverse the effects of etorphine. Timing of events, ambient temperature and snow depth were recorded. Blood samples were cooled and centrifuged before plasma was harvested and frozen. The plasma was thawed later and lactate analysed. Data were analysed using descriptive statistics and regression analysis. ResultsAll animals recovered uneventfully and were alive 12 weeks after immobilization. Mean ± SD plasma lactate was found to be 9.2 ± 2.1 mmol L−1. Plasma lactate concentrations were related positively to snow depth and negatively to time from induction of immobilization to blood sampling. The model that best described the variability in plasma lactate concentrations used induction time (time from firing the dart to the moose being immobilized). The second best model included induction time and snow depth. Conclusions and clinical relevancePlasma lactate concentrations in these etorphine-immobilized moose were in the range reported for other immobilized wild ruminants. Decreasing induction time, which may be related to a more profound etorphine effect, and increasing snow depth possibly may increase plasma lactate concentrations in etorphine-immobilized moose.

Quantitative plasma DNA analysis in Parkinson's disease

Parkinson disease (PD) is a neurodegenerative disease resulting from the loss of the dopaminergic neurons from the substantia nigra pars compacta (SNpc). It is characterized by bradykinesia, rigidity, resting tremor and/or postural instability. The diagnosis of PD is essentially clinical and there is no reliable biological marker to assess its progression. Recently, investigations have been performed on the potential use of circulating cell-free deoxyribonucleic acid (DNA) in the plasma for clinical diagnosis, prognosis and monitoring of human diseases. The aim of this work was to assess the role of free DNA as a biological marker of PD. Forty-two patients with PD (19 men, 23 women) and 20 healthy (7 men, 13 women) subjects were enrolled in this study. Mean ± SD plasma DNA concentration in PD patients and control subjects were, respectively, 16,487 ± 16,378 (range: 100–62,034) kilogenomes-equivalents/L and 37,975 ± 17,832 (range: 15,143–78,783) kilogenomes-equivalents/L. There was a significant difference between control and PD groups ( p < 0.001). There was no correlation between plasma DNA levels and demographic or clinical parameters in PD patients. Free DNA does not seem to be a reliable marker of PD progression. Further research is warranted to confirm the present results to have some value as biomarkers in other neurodegenerative diseases.

A phase I trial of the small molecule pan-bcl-2 inhibitor obatoclax (GX15–070) in combination with docetaxel in patients with relapsed non-small cell lung cancer (NSCLC)

19035 Background: Over expression of bcl-2 family proteins is common in NSCLC and the BH-3 mimetic obatoclax (O) induces apoptosis in a subset of NSCLC where it synergizes with cisplatin (Li et al., Cancer Chemother. Pharmacol., 2008). Single agent O has shown clinical activity in hematological indications across 3 Phase I trials. This is the first trial combining O with a cytotoxic, docetaxel (D). Methods: Eligibility criteria included advanced stage IIIB/IV NSCLC, prior paclitaxel (but not D) allowed, measurable disease, ECOG PS ≤1, disease progression, adequate hematological, renal and hepatic function. D given as a 1 h infusion on day1 followed by flat dose O given as a 24 h continuous infusion on days 1 and 2, every 3 weeks for up to 8 cycles. Dose Level 1: D 55 mg/m2 and O 30 mg X 2; Dose Level 2: D 75 mg/m2 and O 30 mg X 2; Dose Level 3: D 75 mg/m2 and O 45 mg X 2; Dose Level 4: D 75 mg/m2 and O 60 mg X 2. PK samples were obtained at 1, 3, 24, 47 and 49 h after the start of the O infusion. Results: 18 patients enrolled (3, 3, 6 and 6 in consecutive Dose Levels). Patient characteristics: 11 male, median age = 62 (range= 44–81), PS = 0 in 11 and PS = 1 in 7, median prior regimens = 1 (range = 1–6). A total of 74 cycles were administered (median 4, range = 1–8). The only Grade 3–4 adverse events (AEs) were dyspnea (11%) and neutropenia (none in DL1, 60% in DL2–4). Known AEs of O were infrequent: somnolence only in 1/6 at DL4 and euphoria in 1/3 in DL2 and 1/6 in DL3. The mean ± SD plasma concentration of O at 1, 3, 24, 47, and 49 hr time-points from the start of infusion were 2.61±1.96, 2.00±1.43, 3.94±2.88, 4.04±3.33, and 1.61±0.86, respectively at 30 mg dose level. At 45 mg dose, the mean±SD concentrations at same time-points were 5.00±1.59, 6.21±2.24, 4.26±2.01, 7.32±2.84, and 2.42±1.30, respectively, and at 60 mg those concentrations were 5.03±4.61, 8.16±3.17, 10.34±7.34, 12.44±9.42, and 5.45±2.25, respectively. There have been 2 PRs (11%) and 4 confirmed SD (22%). Early PD was noted in 9 (50%). Conclusions: the BH3-mimetic O can be safely administered with D with no increase in neutropenia. The regimen described by DL4 is currently being evaluated in a phase II trial in relapsed NSCLC. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration GeminX GeminX

P‐141: Effect of Modified Scan and Sustain Waveforms on Black Luminance and Address Voltage in an AC Plasma Display Panel

AbstractAlthough the three Electrode Surface Discharge type AC PDP is the de‐facto standard in the Plasma TV industry, one parameter which researchers and manufacturers are working hard to improve is Dark Room Contrast Ratio. Poor DRCR is a result of the high Black luminance caused by strong reset discharge. Another parameter, which has seen a lot of activity, is the Address Voltage. This paper investigates the effect of increasing the negative bias voltage applied to the Scan (Y) electrode while reducing the voltage from sustain voltage level applied to the Sustain (X) electrode during the Reset period and address period. Under the optimum voltage and ramp conditions, the Black Luminance was found to have reduced by a factor of 8 and the Address Voltage reduced to the extent of 15 – 20 Volts as compared to conventional waveform. These improvements were tested and validated in the lab on 42″ SD Plasma Display Panels. The significance of this scheme lies in the fact that the improvement in picture quality as a result of Low Black Luminance and consequent improvement in the Dark Room Contrast Ratio did not lead to an increase in the cost of electronics. In fact a reduction of electronic costs is possible due to reduction in the Address Voltage by allowing the use of cheaper Address Driver ICs.

Plasma B 6 Vitamers in Hemodialysis Subjects Taking Prescription or Over-the-Counter Renal Multivitamin Supplements

Prescription and over-the-counter (OTC) multivitamin supplements are available for hemodialysis (HD) patients. The content of pyridoxine hydrochloride (PN-HCL) in these products ranges from 10 to 50 mg per tablet. Vitamin B-6 is an essential nutrient but it also has the potential at high doses to cause detrimental effects to the nervous system. The purpose of this study was to evaluate the B-6 vitamers in the plasma of hemodialysis subjects who had been taking either prescription or OTC vitamins, and to determine if subjects were experiencing any signs or symptoms associated with vitamin B-6 toxicity.Subjects on HD were grouped by vitamin B-6 intake (n=12/group; 10 or 50 mg PN-HCL per day 5-7 days per week for 6+ months). Plasma B-6 vitamers were analyzed using HPLC. Subjects were questioned regarding signs and symptoms of vitamin B-6 toxicity. Cluster analysis was used to sort subjects into 3 groups by symptoms.The mean ± SD plasma B-6 vitamers (nmol/L) were as follows in the 10 and 50 mg PN-HCL groups respectively: pyridoxal- 5′ -phosphate (PLP) 106 ± 53 and 163 ± 78 (significantly different p<0.04); pyridoxal (PL) 507 ± 396 and 683 ± 306; pyridoxine (PN) 265 ± 150 and 191 ± 107; and 4-pyridoxic acid (4-PA) 433 ± 264 and 994 ± 1361. Mean serum zinc, phosphorus, and alkaline phosphatase values of the groups were not significantly different. The cluster group with a significantly lower mean PLP value of 72 ± 25 nmol/L reported more tingling feet, muscle weakness and pain, balance problems, and itching than did the 2 groups with higher mean plasma PLP values (149 ± 101 and 142 ± 52 nmol/L). The cluster group with a significantly higher mean plasma PA value of 1678 ± 1697 nmol/L reported more tingling hands, tachycardia, and diarrhea. In conclusion, plasma PLP levels in HD subjects are impacted by dose of PN-HCL in supplements, but a higher incidence of neurologically related symptoms are associated with lower plasma PLP or higher plasma PA levels. Prescription and over-the-counter (OTC) multivitamin supplements are available for hemodialysis (HD) patients. The content of pyridoxine hydrochloride (PN-HCL) in these products ranges from 10 to 50 mg per tablet. Vitamin B-6 is an essential nutrient but it also has the potential at high doses to cause detrimental effects to the nervous system. The purpose of this study was to evaluate the B-6 vitamers in the plasma of hemodialysis subjects who had been taking either prescription or OTC vitamins, and to determine if subjects were experiencing any signs or symptoms associated with vitamin B-6 toxicity. Subjects on HD were grouped by vitamin B-6 intake (n=12/group; 10 or 50 mg PN-HCL per day 5-7 days per week for 6+ months). Plasma B-6 vitamers were analyzed using HPLC. Subjects were questioned regarding signs and symptoms of vitamin B-6 toxicity. Cluster analysis was used to sort subjects into 3 groups by symptoms. The mean ± SD plasma B-6 vitamers (nmol/L) were as follows in the 10 and 50 mg PN-HCL groups respectively: pyridoxal- 5′ -phosphate (PLP) 106 ± 53 and 163 ± 78 (significantly different p<0.04); pyridoxal (PL) 507 ± 396 and 683 ± 306; pyridoxine (PN) 265 ± 150 and 191 ± 107; and 4-pyridoxic acid (4-PA) 433 ± 264 and 994 ± 1361. Mean serum zinc, phosphorus, and alkaline phosphatase values of the groups were not significantly different. The cluster group with a significantly lower mean PLP value of 72 ± 25 nmol/L reported more tingling feet, muscle weakness and pain, balance problems, and itching than did the 2 groups with higher mean plasma PLP values (149 ± 101 and 142 ± 52 nmol/L). The cluster group with a significantly higher mean plasma PA value of 1678 ± 1697 nmol/L reported more tingling hands, tachycardia, and diarrhea. In conclusion, plasma PLP levels in HD subjects are impacted by dose of PN-HCL in supplements, but a higher incidence of neurologically related symptoms are associated with lower plasma PLP or higher plasma PA levels.

Effects of ultraviolet radiation on plasma 25-hydroxyvitamin D3 concentrations in corn snakes (Elaphe guttata)

To determine whether corn snakes exposed to UVB radiation have increased plasma 25-hydroxyvitamin D3 concentrations, compared with control snakes. 12 corn snakes (Elaphe guttata). After an acclimation period in individual enclosures, a blood sample was collected from each snake for assessment of plasma 25-hydroxyvitamin D3 concentration. Six snakes were provided with no supplemental lighting, and 6 snakes were exposed to light from 2 full-spectrum coil bulbs. By use of a radiometer-photometer, the UVA and UVB radiation generated by the bulbs were measured in each light-treated enclosure at 3 positions at the basking surface and at 2.54 cm (1 inch) below each bulb surface; the arithmetic mean values for the 3 positions at the basking surface and each individual bulb surface were calculated immediately after the start of the study and at weekly intervals thereafter. At the end of the study (day 28), another blood sample was collected from each snake to determine plasma 25-hydroxyvitamin D3 concentration. Mean +/- SD plasma concentration of 25-hydroxyvitamin D3 in snakes that were provided with supplemental lighting (196 +/- 16.73 nmol/L) differed significantly from the value in control snakes (57.17 +/- 15.28 nmol/L). Mean exposure to UVA or UVB did not alter during the 4-week study period, although the amount of UVA recorded near the bulb surfaces did change significantly. These findings have provided important insight into the appropriate UV radiation requirements for corn snakes. Further investigation will be needed before exact husbandry requirements can be determined.

Association of Galactose Single‐Point Test Levels and Phenytoin Metabolic Polymorphisms with Gingival Hyperplasia in Patients Receiving Long‐Term Phenytoin Therapy

To evaluate whether the occurrence or severity of gingival hyperplasia is associated with liver function test results or phenytoin metabolism. Prospective analysis. University-affiliated medical center in Taipei, Taiwan. Sixty-six patients (mean age 37.9 yrs) with epilepsy who were receiving phenytoin for more than 1 year. Intervention. Four blood samples were drawn from each patient for liver function testing, concentrations of phenytoin and its metabolites R-5-(4'-hydroxyphenyl)-5-phenylhydantoin (R-HPPH) and S-HPPH, and genotyping of cytochrome P450 (CYP) 2C9 and 2C19. Plasma concentrations of phenytoin and its metabolites were determined by a high-performance liquid chromatography method. The CYP2C9 and CYP2C19 genotypes were analyzed by polymerase chain reaction-restriction fragment length polymorphism analysis. Conventional liver function assays and a quantitative liver function test--galactose single-point (GSP) measurement--were performed. Statistical analyses were performed to evaluate the association between liver function test results as well as metabolic phenotype and the occurrence and severity of gingival hyperplasia. Among liver function tests, only GSP levels showed a significant difference between patients with and those without gingival hyperplasia. Patients with an elevated GSP level (> or = 280 microg/ml) had a significantly higher odds ratio (OR 4.51) for the occurrence of gingival hyperplasia. In addition, increased R-HPPH (OR 1.02) and phenytoin (OR 1.09) concentrations were associated with an increased occurrence of gingival hyperplasia. However, only increased GSP and R-HPPH concentrations had significantly higher ORs (2.84 and 1.02, respectively) associated with the severity of gingival hyperplasia. Although mean +/- SD plasma R-HPPH concentration was significantly lower in CYP2C19 poor metabolizers compared with CYP2C9 and CYP2C19 extensive metabolizers and CYP2C9 poor metabolizers (30.38 +/- 16.73 vs 68.22 +/- 44.75 and 78.95 +/- 51.67 microg/ml, respectively), no significant association between genotype and gingival hyperplasia was found. Increased GSP, phenytoin, and R-HPPH concentrations were associated with increased occurrence of phenytoin-induced gingival hyperplasia; only increased GSP and R-HPPH concentrations were associated with increased severity of this adverse effect.

Assessment of three automated assays for C-reactive protein determination in dogs

To determine the characteristics of an automated canine C-reactive protein (CRP) assay and evaluate 2 human CRP assays for use in dogs. Animals-56 client-owned dogs with pyometra and 11 healthy control dogs. Samples from 11 dogs with high (> 100 mg/L) or low (< 10 mg/L) CRP concentrations (determined by use of a canine ELISA) were evaluated by use of the automated canine CRP assay. Intra- and interassay imprecision was determined (by use of those 2 plasma pools), and assay inaccuracy was assessed by use of logistic regression analysis of results obtained via ELISA and the automated canine CRP assay. Two automated human CRP assays were used to measure plasma CRP concentration in 10 dogs. By use of the ELISA, mean +/- SD plasma CRP concentration was 96.1 +/- 38.5 mg/L and 10.1 +/- 23.2 mg/L in dogs with pyometra and control dogs, respectively. The automated canine assay had intra-assay coefficients of variation (CVs) of 7.8% and 7.9%, respectively, and interassay CVs of 11.1% and 13.1%, respectively. Results from the automated assay were highly correlated with results obtained via ELISA. The human assay results did not exceed 0.4 mg/L in any dog. The automated canine CRP assay had less interassay imprecision, compared with the ELISA. The 2 human CRP assays were not suitable for analysis of canine plasma samples. The automated canine CRP assay was more precise than the ELISA for serial evaluations of plasma CRP concentration in dogs.

A Phase II Trial of the Small Molecule Pan-Bcl-2 Family Inhibitor Obatoclax Mesylate (GX15-070) Administered by a 24-h Continuous Infusion Every 2 Weeks to Patients with Chronic Idiopathic Myelofibrosis (CIMF).

Obatoclax is an antagonist of the BH3-binding groove of the bcl-2 family of anti apoptotic proteins. It activates apoptosis and has clinical activity in chronic lymphocytic leukemia (CLL; O'Brien et al, ASH 2005) and myelodysplastic syndromes (MDS ; Borthakur et al., ASH 2006). In both CLL and MDS, treatment with obatoclax has resulted in achievement of red blood cell transfusion independence in chronically anemic patients. CIMF is also frequently associated with chronic anemia as well as activating mutations of the JAK2 kinase. Activated JAK2 in turns activates Stat5 which leads to the transcriptional activation of bcl-xl. Currently ongoing two-stage trial was designed to detect a ≥30% response rate to obatoclax given as a flat dose of 60 mg by 24-h infusion every 2 weeks (2-week period equals one cycle) using the International Working Group Consensus Criteria. Patients were assessed for response every 2 weeks while on therapy. Of the 19 patients required for Stage 1, 17 have been enrolled and 14 currently have data available. Median age was 68 (range: 45–89) and 8 patients were male. JAK2 mutated in 3, wild type in 3, status unknown in 8. Prior CIMF directed therapy other then hydroxyurea and erythropoietin was given to 8 patients (1–3 regimens, median = 1). A total of 102 cycles have been administered with 3 patients still receiving obatoclax. The most common adverse events (AEs) were fatigue (57%), gait disturbance (43%), dyspnea (43%), nausea (36%), peripheral edema (36%), diarrhea (29%), chest pain (29%), chills (29%), weight loss (29%), dizziness (29%), headache (29%), cough (29%), hyperhydrosis (29%), somnolence (21%) and euphoria (21%). All were of Grades 1–2 with the exception of 3 Grade 3 AEs of peripheral edema, 2 of dyspnea, 2 of fatigue and one each of diarrhea and chest pain. Two patients died of disease related complications shortly after having received their first cycle of obatoclax. The plasma concentrations of obatoclax appeared to have reached a steady state before end of infusion. The mean ±SD plasma levels at 0, 3, and 23 hr time-points after infusion started were 0, 6.45±2.64, and 4.33±0.83 ng/mL, respectively. Two patients amongst the 8 previously treated experienced a Clinical Improvement Response persisting 6 months with increases in hemoglobin and red blood cell transfusion independence, while continuing to receive chronic recombinant erythropoietin therapy to which they had not previously responded. While still responding, one was referred for an unrelated donor allogeneic stem cell transplant while the other progressed after 6 months. Of the 6 previously untreated patients 3 are still receiving therapy with stable disease.Conclusions: Obatoclax shows activity in CIMF. Enrollment is now focusing on patients without prior CIMF-directed therapies in order to better estimate the therapeutic potential of bcl-2 family inhibition in this disease.