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Plasma Samples (plasma + sample)
Kinds of Plasma Samples Selected AbstractsPharmacokinetics of carisbamate (RWJ-333369) in healthy Japanese and Western subjectsEPILEPSIA, Issue 8 2009Peter Zannikos Summary Purpose:, To compare the pharmacokinetics of carisbamate (RWJ-333369) in healthy Japanese and Western adults, and to comparatively assess carisbamate safety and tolerability between the two populations. Methods:, An open-label study was conducted in 24 Japanese and 24 Caucasian healthy subjects. Subjects received a single oral dose of 250 mg carisbamate on day 1 followed by a 3-day washout period; twice-daily dosing of 250 mg carisbamate on days 5,8; subsequently, 500 mg on days 9,12 and a single dose of 500 mg on day 13. Plasma samples were collected for a pharmacokinetic analysis on days 1, 8, and 13. Plasma and urine samples were analyzed for carisbamate and its urinary metabolites by liquid-chromatography-mass-spectrometry. Results:, Following a single dose, carisbamate Cmax and area under the curve (AUC) geometric mean ratios were 16.4% and 28.8% higher in Japanese than in Caucasians, respectively; these differences were statistically significant and their 90% confidence intervals (CIs) fell outside of the 80,125% limits, which are considered not to be of clinical significance. With dose,body weight normalization, Cmax and AUC were similar in Japanese and Caucasian subjects and the 90% CIs were within the 80,125% boundaries. Carisbamate was well tolerated, and its mean oral clearance and half-life were similar in both groups, ranging from 35.1,41.4 ml/h/kg and 11.5,12.8 h. Discussion:, Carisbamate plasma exposure (AUC) and Cmax in Japanese subjects is ,20,25% higher than in Caucasians due to a higher mg/kg dose. After body weight normalization, carisbamate pharmacokinetics was similar between Japanese and Caucasian subjects following single and multiple dosing, and showed the same dose proportionality. [source] A diet enriched with mackerel (Scomber scombrus),derived products improves the endothelial function in a senior population (Prevención de las Enfermedades Cardiovasculares: Estudio Santoña , PECES project)EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2009J. R. De Berrazueta ABSTRACT Background, Regular consumption of fish reduces cardiovascular risks. Here, we investigate if the consumption of products with mackerel (Scomber scombrus) with 8·82 g of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) content per 100 g of product improves parameters of endothelial function in a controlled population. Materials and methods, Subjects maintained a 12-week diet with products with mackerel. The population consisted of 58 senior subjects (12 withdrawals, 25 women), aged 82·08 ± 8·13 years (Group A). Twenty-three senior subjects (13 women) on a regular diet were used as the control group (Group B). Subjects of Group A received 57 portions throughout 12 weeks (four to five portions a week of products with a mean EPA + DHA content of 2·5 g a day). A continuous follow-up and a final evaluation were performed to determine the level of consumption. Plasma samples were stored at ,70 °C for a biochemical study. Endothelial function was analysed by reactive hyperemia with a mercury strain gauge plethysmography with measurement of blood flow in the forearm, both baseline and at the end of the 12-week diet. Results, Endothelium-dependent vasodilatation significantly increased in Group A subjects (P < 0·001). No changes were found in Group B. The subgroup analyses showed that improvements were produced in Group A subjects without cardiovascular disease (P < 0·001). Nitrites/nitrates and von Willebrand factor plasma concentrations were higher in participants after the 12-week diet. Conclusions, The consumption of mackerel meat products improves endothelium-dependent, flow-mediated vasodilatation in a senior population. This finding might explain some of the cardioprotective effects of fish consumption. [source] Elevated cerebrospinal fluid adiponectin and adipsin levels in patients with multiple sclerosis: a Finnish co-twin studyEUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2010A. Hietaharju Background and purpose:, The aim of this study was to investigate the levels of three adipocytokines: leptin, adiponectin and adipsin, in serum and cerebrospinal fluid (CSF) of twins discordant for multiple sclerosis (MS). Adipose tissue is an important component connecting immune system and several tissues and organs including CNS. Fat cells produce adipocytokines, which seem to have a role in various autoimmune disorders including MS. Methods:, Plasma samples were collected from twelve twins and CSF samples from four twins discordant for MS. The concentrations of interleukine (IL)-6, adiponectin, adipsin and leptin in plasma and CSF samples were determined by enzyme immuno assay. Results:, A significant difference was seen in the adipocytokine levels in CSF samples. Twins with MS had higher concentrations of adiponectin (P = 0.039) and adipsin (P = 0.039), than their asymptomatic co-twins. Conclusion:, As adiponectin and adipsin levels in CSF did not correlate with their levels in plasma, it seems that there could be a secondary intrathecal synthesis of these adipocytokines in MS. [source] Age-related plasma reference ranges for two heparin-binding proteins , vitronectin and platelet factor 4INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2009F. NEWALL Summary This study was conducted to establish age-related reference ranges for two heparin-binding proteins , vitronectin and platelet factor 4 (PF4) , and to determine if the quantitative values of these proteins may contribute to the reported age-dependent effect of unfractionated heparin (UFH). Plasma samples were obtained from healthy children aged between 1 month and 16 years and from healthy adult volunteers. Two commercial kits were used to measure plasma vitronectin and PF4 levels. Results were reported as mean and boundaries including 95% of the population. Plasma vitronectin levels for children aged 1,5 years were significantly higher compared with adults. Plasma PF4 levels for infants <1 year of age were significantly lower compared with adults. The differences between reference values for both proteins in all other age-groups were not statistically significant. This study for the first time has established age-related reference ranges for vitronectin and PF4. In establishing these ranges, the quantitative values of these proteins do not appear to be the major contributory cause for the age-dependent variation in UFH effect. Future studies are required to evaluate the possible impact of age-dependent differences in binding between heparin-binding proteins and UFH. [source] Influence of the surface on thrombin generationINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 4 2008T. W. STIEF Summary Thrombin generation depends on the surface of the blood vessel or container. With a new ultra-sensitive and -specific thrombin assay the surface-dependent thrombin generation was quantified. Citrated blood or plasma was preincubated for 1 h (37 °C). Citrated blood, plasma, or plasma with 0,10 g/l hemoglobin,erythrocyte microparticles (Hb,MP) were preincubated at 23 °C or at 37 °C. Plasma samples (50 ,l) were recalcified in polystyrol (PS) wells and incubated for different coagulation reaction times (CRT). Final supramolar arginine concentrations, 0.1% Triton X 100, and chromogenic thrombin substrate concentrations in the onefold km,range were added and the linear ,A/t was measured in the recalcified coagulation activity assay (RECA). Aprotinin or corn trypsin inhibitor were added. (i) Recalcification of plasma (in different monovettes) pre-incubated for 1 h (37 °C) generated the following thrombin activities after 7 min (37 °C): 0.74 IU/ml (polypropylene (PP)-citrate), 0.39 IU/ml (PP-EDTA), 0.06 IU/ml (PP-heparin), 1.38 IU/ml (PS), 0.63 IU/ml (1 ml volume PP), 0.13 IU/ml (15 ml volume PP), and 3.62 IU/ml (glass). (ii) Recalcification of preincubated whole blood generated up to about fivefold more thrombin. (iii) Thrombin generation is proportional to the plasmatic concentration of Hb,MP, 10 g/l Hb,MP generating about 4 IU/ml thrombin within 20 min CRT. (iv) The IC50 of aprotinin and corn typsin inhibitor on thrombin generation in RECA are about 2 KIU/ml and about 1 U/ml, respectively. The reaction wall, the preincubation temperature, and hemolysis influences thrombin generation. The RECA allows to diagnose the prothrombotic capacity of any material. [source] S100A8/A9: A Potential New Diagnostic Aid for Acute AppendicitisACADEMIC EMERGENCY MEDICINE, Issue 3 2010John F. Bealer MD Abstract Objectives:, Diagnosing acute appendicitis is a daunting clinical challenge, as there is no single test that reliably distinguishes acute appendicitis from other etiologies of acute abdominal pain. In this study, the authors examined whether circulating levels of S100A8/A9 could be useful as a marker to aid in the diagnosis of acute appendicitis. Methods:, Plasma samples from emergency department (ED) patients with acute abdominal pain (n = 181) were tested using an immunoassay for S100A8/A9. Results:, The sensitivity and specificity for S100A8/A9 in diagnosing acute appendicitis were estimated to be 93% (95% confidence interval [CI] = 81% to 97%) and 54% (95% CI = 45% to 62%), respectively. Negative predictive value (NPV) was 96% (95% CI = 89% to 99%), and positive predictive value (PPV) was 37% (95% CI = 28% to 47%). Performance characteristics of elevated white blood cell (WBC) count were also estimated: sensitivity 63% (95% CI = 47% to 76%), specificity 67% (95% CI = 59% to 75%), NPV 86% (95% CI = 78% to 91%), and PPV 36% (95% CI = 26% to 47%). Conclusions:, This is the first report exploring the relationship between circulating S100A8/A9 and acute appendicitis and establishes proof of concept for this biomarker as a diagnostic test for acute appendicitis. Further studies are indicated to optimize the use of this biomarker, in conjunction with other established approaches. ACADEMIC EMERGENCY MEDICINE 2010; 17:333,336 © 2010 by the Society for Academic Emergency Medicine [source] Value of ADAMTS13 activity and inhibitor in the postmortem diagnosis of thrombotic thrombocytopenic purpuraJOURNAL OF CLINICAL APHERESIS, Issue 3 2009Denis M. Dwyre Abstract Background and Objectives: Thrombotic thrombocytopenic purpura (TTP) is a clinical diagnosis that can be difficult to establish in severely ill patients. We report a case of fulminant TTP in a woman who died before receiving plasma exchange. An autopsy plasma sample was analyzed for ADAMTS13 activity and inhibitor for correlation with the diagnosis of TTP. Recognizing that hemolysis in postmortem blood samples could interfere with ADAMTS13 activity, plasma samples from four additional decedents not suspected of having TTP were analyzed and correlated with their autopsy results. The purpose of this study was to assess whether testing postmortem samples for ADAMTS13 is useful in the postmortem diagnosis of TTP. Material and Methods: Plasma samples from the index case and four non-TTP decedents were analyzed for ADAMTS13 activity, ADAMTS13 inhibitor levels, and plasma free hemoglobin (PFH). Autopsy tissues were evaluated for evidence of platelet microthrombi in all five cases. Results: The ADAMTS13 activity level in the index patient was <4%, and the inhibitor level was 1.0 inhibitor unit. Microthrombi were prominent in the heart, kidneys, pancreas, and adrenal glands, consistent with the clinical diagnosis of TTP. ADAMTS13 activity levels in the four non-TTP decedents ranged from 4 to 82% (3/4 , 26%), and inhibitor was present in two of the four samples. Postmortem PFH levels in the four non-TTP decedents ranged from 64 to 3,917 mg/dL. No microthrombi were observed. Conclusion: Low postmortem ADAMTS13 activity and evidence of inhibitor can occur in decedents without clinical or histologic evidence of TTP. Postmortem ADAMTS13 activity levels may not be valid in establishing a diagnosis of TTP, and high inhibitor levels in this setting may be related to elevated PFH. Caution must be used in the interpretation of ADAMTS13 testing in the presence of hemolysis. J. Clin. Apheresis 2009. © 2009 Wiley-Liss, Inc. [source] Oxidative stress during leukocyte absorption apheresisJOURNAL OF CLINICAL APHERESIS, Issue 2 2003Aki Hirayama Abstract Leukocyte absorption apheresis absorbs leukocytes to the apheresis columns involving leukocyte activation. This process is regarded as bioincompatible and avoided in hemodialysis or other extracorporeal circulation processes. Thus, leukocyte apheresis has a potential risk to exacerbate in vivo oxidative stress. We evaluated the changes in plasma oxidative stress during leukocyte apheresis. Patients diagnosed as ulcerative colitis (UC) and treated with leukocyte apheresis were studied. Adacolumn (celluloseacetate beads) or Cellsorba EX (polyethylenephtarate fiber) was used for the leukocyte absorption device. Oxidative stress was measured by thiobarbituric acid reactive substances (TBARS) and hydroxyl radical (,OH) scavenging activity. Plasma samples were collected from the pre- and post-column sampling port at the start, and from the pre-column sampling port at the end of the treatment. The ,OH signal intensities (OHRI) significantly increased during a column passage, indicating a loss of plasma ,OH scavenging activity. However, OHRI was reduced at the end, suggesting a recovery of radical scavenging activity during leukocyte apheresis. Significant decreases of OHRI and TBARS were only observed in the early phase of the therapeutic course. No differences of OHRI and TBARS levels were observed between the two columns. These results indicate that though the plasma antioxidant activity was diminished by a column passage, plasma antioxidant activity recovers during the procedure. This efficient antioxidative effect is limited to the early phase of the therapeutic course. J. Clin. Apheresis 18:61,66, 2003. © 2003 Wiley-Liss, Inc. [source] Use of a new silica clotting time for diagnosing lupus anticoagulant in patients who meet the clinical criteria for antiphospholipid syndromeJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 1 2006Panagiotis Grypiotis Abstract The silica clotting time (SCT) is a phospholipid-dependent coagulation assay used for the laboratory diagnosis of lupus anticoagulant (LA) antibodies. The sensitivity and specificity of a new commercial SCT for identifying LA in patients who meet the clinical criteria for antiphospholipid syndrome (APS), and its association with thrombotic events were evaluated here. Forty-five patients who met the clinical criteria for APS according to the Sapporo International Consensus Statement were examined. Sixty-nine patients who did not meet the clinical criteria for APS, and 20 blood donors were used as controls. Plasma samples from the patients and controls were tested for LA using a new commercial SCT with low and high synthetic phospholipid concentrations. The results were compared with those obtained by diluted Russell's viper venom time (dRVVT) and activated partial thromboplastin time (APTT). SCT's sensitivity for identifying LA in patients who met the clinical criteria of APS was higher compared to APTT and dRVVT (53.3% vs. 31.1% and 31.1%), and the specificities of these assays were 96.6%, 100%, and 98.9%, respectively. When dRVVT was combined with SCT, and dRVVT was combined with APTT their sensitivities were 57.7% and 48.8%, and their specificities were 96.6% and 98.9%, respectively. A stepwise logistic regression analysis indicated that the combination of dRVVT with SCT was associated with total thrombotic events (odds ratio (OR)=11.5, 95% confidence interval (CI)=1.25,106.3, P=0.031) as well as with venous thrombosis (OR=4.09, 95% CI=1.16,14.43, P=0.028). According to our results, SCT is the most sensitive assay for identifying LA in patients who meet the clinical criteria for APS. Moreover, the highest sensitivity was reached with a combination of SCT and dRVVT. The method's association with total thrombotic events and venous thrombosis was in fact significant. J. Clin. Lab. Anal. 20:15,18, 2006. © 2006 Wiley-Liss, Inc. [source] Depression following open-heart surgery: A path model involving interleukin-6, spiritual struggle, and hope under preoperative distressJOURNAL OF CLINICAL PSYCHOLOGY, Issue 10 2010Amy L. Ai Abstract Faith factors (i.e., factors pertaining to religion/spirituality) have been linked with well-being and adequate coping. Few studies have investigated negative aspects of religious coping, such as spiritual struggle. Based on the multidisciplinary literature and on previous findings, the study's analysis estimated parallel psychophysiological pathways from preoperative distress to postoperative depression in patients undergoing open heart surgery. Plasma samples for interleukin(IL)-6 were obtained before surgery. The results showed that a link between spiritual struggle and IL-6 mediated the indirect effects of preoperative anxiety on postoperative depression. Avoidant coping also mediated the influence of anxiety on postoperative maladjustment. Further, hope played a protective mediating role to moderate the undesirable influences of the spiritual struggle,IL-6 link and maladaptive coping on postoperative mental health attributes. © 2010 Wiley Periodicals, Inc. J Clin Psychol 66:1,19, 2010. [source] Determination of 17,-estradiol in bovine plasma: development of a highly sensitive technique by ion trap gas chromatography,tandem mass spectrometry using negative chemical ionization,JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 12 2002Giancarlo Biancotto Abstract A novel approach to the determination of 17,-estradiol in bovine plasma is presented. The observed enhanced sensitivity is gained by the application of tandem mass spectrometry (MS) fragmentation to a stable, well characterized negative ion produced by chemical ionization (methane as reagent gas). A specific derivatizing reactant is employed (pentafluorobenzyl bromide), combined with bis-trimethylsilyltrifluoroacetamide, to favor the formation of a diagnostic precursor negative ion. Plasma samples are purified through a C18 solid phase extraction column and derivatized before gas chromatography,MS analysis. The accuracy and the precision of the method, tested over a set of spiked samples, were satisfactory. The limit of detection was found to be 5 pg ml,1 and the limit of quantification was fixed at 20 pg ml,1. The fragmentation pattern is fully explained and the method is applicable for the official analysis of bovine plasma for the detection of 17,-estradiol according to the European criteria 256/93 and to the draft SANCO/1805/2000 rev. 3. The quantification of incurred positive samples was performed according to the proposed procedure and compared with the results obtained by standardized radio immuno assay; the estimated concentrations were significantly similar. Copyright © 2002 John Wiley & Sons, Ltd. [source] Molecular epidemiology of HIV in Ghana: Dominance of CRF02_AGJOURNAL OF MEDICAL VIROLOGY, Issue 2 2004Lucia Fischetti Abstract Recent studies showed the importance of CRF02_AG in West Africa, although the clinical relevance of these recombinant forms of HIV remains unknown. The present study aimed at determining the molecular diversity of HIV in Ghana and investigating the possible epidemiologic advantage of recombinant HIV-1. Plasma samples collected in 1999,2002 from two populations of HIV infected individuals (144 asymptomatic candidate blood donors and 169 AIDS patients) were studied and 249 of them were molecularly characterised in gag, pol, and env regions. Five molecular groups were identified: strains clustering with CRF02_AG in all regions (147/249 or 59%), recombinant strains clustering with CRF02_AG in one or two regions (50/249 or 20%), other subtypes, pure or recombinant, but not involving CRF02_AG (37/249 or 15%), HIV-2 (11/249 or 4.5%), and double infections (4/249 or 1.5%). There was no significant difference in the distribution of HIV-1 recombinant strains according to clinical presentation. No evidence of a significant increase in CRF02_AG prevalence between 1999 and 2002 was found. Irrespective of clinical condition, CRF02_AG is the predominant molecular form of HIV-1 in Kumasi, Ghana. J. Med. Virol. 73:158,166, 2004. © 2004 Wiley-Liss, Inc. [source] Measles virus protein-specific IgM, IgA, and IgG subclass responses during the acute and convalescent phase of infectionJOURNAL OF MEDICAL VIROLOGY, Issue 2 2004H.S. El Mubarak Abstract The availability of new generation serological assays allowed re-evaluation of the antibody response to measles virus. IgM, IgA, total IgG, and IgG subclass responses were studied to the three major immunogenic measles virus proteins: the fusion protein (F), haemagglutinin (H), and nucleoprotein (N). Plasma samples were obtained from clinically diagnosed measles cases (n,=,146) in Khartoum (Sudan) within a week after onset of the rash. Convalescent phase samples were collected from 32 of 117 laboratory-confirmed measles cases at different time points after onset of rash. Glycoprotein-specific IgM, IgG, and IgA antibody levels correlated well to the N-specific response. For IgG and IgA, responses to F were higher than to H. IgA antibody levels were undetectable in about one third of the laboratory-confirmed cases during the acute phase, but positive in all patients tested 1,4 weeks after infection. IgM levels declined rapidly and were lost 3,6 months after infection. IgA levels declined slowly during the first year but did not return to background levels during the subsequent 2 years. IgG avidity maturation was detected during a 3,6 month period after infection. The predominant IgG subclasses during the acute phase were IgG1 and IgG3. The latter was lost in the convalescent phase, while the IgG4 isotype showed a slight rise afterwards. Interestingly, acute phase IgG3 and IgA responses were associated, and were only detected in samples with high IgG. This study provides a comprehensive perspective on the antibody response to wild-type measles virus infection. J. Med. Virol. 72:290,298, 2004. © 2004 Wiley-Liss, Inc. [source] A Critical Evaluation of Influence of Ethanol and Diet on Salsolinol Enantiomers in Humans and RatsALCOHOLISM, Issue 2 2010Jeongrim Lee Background:, (R/S)-Salsolinol (SAL), a condensation product of dopamine (DA) with acetaldehyde, has been speculated to have a role in the etiology of alcoholism. Earlier studies have shown the presence of SAL in biological fluids and postmortem brains from both alcoholics and nonalcoholics. However, the involvement of SAL in alcoholism has been controversial over several decades, since the reported SAL levels and their changes after ethanol exposure were not consistent, possibly due to inadequate analytical procedures and confounding factors such as diet and genetic predisposition. Using a newly developed mass spectrometric method to analyze SAL stereoisomers, we evaluated the contribution of ethanol, diet, and genetic background to SAL levels as well as its enantiomeric distribution. Methods:, Simultaneous measurement of SAL enantiomers and DA were achieved by high performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS). Plasma samples were collected from human subjects before and after banana (a food rich in SAL) intake, and during ethanol infusion. Rat plasma and brain samples were collected at various time points after the administration of SAL or banana by gavage. The brain parts including nucleus accumbens (NAC) and striatum (STR) were obtained from alcohol-non-preferring (NP) or alcohol-preferring (P) rats as well as P-rats which had a free access to ethanol (P-EtOH). Results:, Plasma SAL levels were increased significantly after banana intake in humans. Consistently, administration of banana to rats also resulted in a drastic increase of plasma SAL levels, whereas brain SAL levels remained unaltered. Acute ethanol infusion did not change SAL levels or R/S ratio in plasma from healthy humans. The levels of both SAL isomers and DA were significantly lower in the NAC of P rats in comparison to NP rats. The SAL levels in NAC of P rats remained unchanged after chronic free-choice ethanol drinking. There were decreasing trends of SAL in STR and DA in both brain regions. No changes in enantiomeric ratio were observed after acute or chronic ethanol exposure. Conclusions:, SAL from dietary sources is the major contributor to plasma SAL levels. No significant changes of SAL plasma levels or enantiomeric distribution after acute or chronic ethanol exposure suggest that SAL may not be a biomarker for ethanol drinking. Significantly lower SAL and DA levels observed in NAC of P rats may be associated with innate alcohol preference. [source] Determination of the small cell lung cancer associated biomarker pro-gastrin-releasing peptide (ProGRP) using LC-MSJOURNAL OF SEPARATION SCIENCE, JSS, Issue 2 2007Bjørn Winther Abstract Small cell lung cancer is a rapidly growing neoplasm with high mortality. A recently discovered biomarker, pro-gastrin-releasing peptide (ProGRP), is used as a specific diagnostic marker for the disease. The present methods of quantification are based on the immunoassay techniques RIA and ELISA. Our object was to develop an LC-MS method for the detection and quantification of ProGRP using specific tryptic digestion products from the recombinant peptide ProGRP (31,98), a sequence common to three isoforms of ProGRP. The conditions for enzymatic cleavage were optimized and MS compatibility was obtained. Digestion of ProGRP (31,98) yielded an array of peptide products and these were evaluated for further method development. The peptide product NLLGLIEAK proved to be the preferable candidate to monitor ProGRP due to signal intensity, column retention, and peptide specificity. The identity of this product was verified by means of LC-MS/MS and the linearity of the calibration curve evaluated. LOD was calculated to be 13.9 pg on column (O.C.). Plasma samples spiked with ProGRP (31,98) prior to digestion verified the suitability of this digest product for the determination of ProGRP. LC-MS may prove to be a valuable tool for biomarker mediated diagnosis in the future. [source] The antigenic binding site(s) of antibodies to factor XII associated with the antiphospholipid syndromeJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2005S. L. HARRIS Summary., Phospholipid binding proteins, including factor XII (FXII), are known to be targeted by antiphospholipid antibodies (aPA). Factor XII antibodies (FXIIab) have been described in some patients with the antiphospholipid syndrome (APS) and have been shown to lead to reduced levels of FXII. The antigenic binding site(s) and the pathophysiological effects of FXIIab are unknown. In an attempt to elucidate the binding site of these antibodies, immobilized plasma kallikrein was used to cleave FXII into its 52-kDa heavy-chain (HCFXII) and 28-kDa light-chain (LCFXII) components. Plasma samples from 12 female patients with definite APS and FXIIab were investigated for the presence of antibodies to FXII, HCFXII and LCFXII. All but one patient's plasma reacted to FXII, HCFXII and LCFXII in a similar manner. One patient gave markedly reduced positivity to HCFXII and LCFXII, suggesting that the FXIIab in this patient had a higher affinity for the intact FXII molecule. To further investigate the antigenic binding site(s) of FXII, 150 biotinylated peptides of the known FXII sequence were synthesized using a MultipinTM peptide synthesis procedure. The IgG and IgM fractions of the 12 patients' plasma were purified by affinity chromatography. The synthesized peptides were captured on streptavidin plates and individual patients' purified FXIIab assayed against the peptides in a modified enzyme-linked immunosorbent assay (ELISA). Two regions were identified as possible antigenic binding site(s) for FXIIab: one in the growth factor domain and the other in the catalytic domain. [source] Pharmacodynamics of Carvedilol in Conscious, Healthy DogsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 2 2006Sonya G. Gordon The purpose of the study reported here was to determine the magnitude and duration of beta-blocking efficacy, determine an effective dose and dosing interval, and document safety and tolerability of carvedilol given orally in clinically normal dogs. Pharmacodynamic data were evaluated in conscious, unrestrained, healthy hound dogs at baseline and after long-term oral administration of carvedilol (1.5 mg/kg of body weight PO q12h for >5 days). At baseline, heart rate (HR) and blood pressure (BP) data were collected continuously for 24 hours, and complete echocardiography was performed. This protocol was repeated after long-term oral carvedilol administration. Additionally, isoproterenol was administered to evaluate the magnitude and duration of the nonselective beta-blocking efficacy of carvedilol. An isoproterenol challenge was performed 0.75, 1.5, 2.25, 4, 6, 12, and 24 hours after carvedilol administration, with echocardiography being performed once at 2 hours. Plasma samples were obtained prior to each challenge time point for determination of plasma carvedilol concentration. Time series regression analysis indicated no difference between baseline and carvedilol-induced HR or BP trend lines in 6 of 8 dogs. In 2 of 8 dogs, HR, after long-term carvedilol administration, was reduced. Carvedilol attenuated isoproterenol-induced changes in HR by 54,76% through 12 hours and by 30% at 24 hours. The BP changes were attenuated by 80,100% through 12 hours. These data suggest that carvedilol (1.5 mg/kg PO q12h) in healthy, conscious dogs confers nonselective beta blockade for 12 hours, with minimal effects on resting HR, BP, and echocardiographic variables. Additionally, the magnitude of beta blockade correlated strongly to peak plasma carvedilol concentration, suggesting that therapeutic drug monitoring may be clinically useful. [source] Hemostatic Changes in Dogs with Naturally Occurring SepsisJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2003Armelle M. de Laforcade Sepsis is a frequent source of morbidity and mortality in critically ill patients. The goal of this case control study was to measure hemostatic changes in dogs with naturally occurring sepsis. Blood was collected within 24 hours of admission from 20 dogs that fulfilled the criteria for sepsis. Sepsis was defined as histologic or microbiological confirmation of infection and 2 or more of the following criteria: hypo- or hyperthermia, tachycardia, tachypnea, or leukopenia, leukocytosis, or >3% bands. Culture and sensitivities were performed on appropriate samples from all septic dogs. Twenty-eight control dogs were enrolled on the basis of normal results of physical examination, CBC, serum biochemistry, and coagulation profile. Plasma samples were analyzed for prothrombin time (PT), partial thromboplastin time (PTT), fibrin(ogen) degradation products (FDP), D-dimer (DD) concentrations, antithrombin (AT) activity, and protein C (PC) activity. Data were compared between groups by chi-square or independent t -tests. PC (P < .001) and AT (P < .001) activities were significantly lower in dogs with sepsis compared to controls. Dogs with sepsis had significantly higher PT (P= .007), PTT (P= .005), D-dimer (P= .005), and FDP (P= .001) compared to controls. Platelet counts were not significantly different between groups. Ten of the 20 septic dogs (50%) died, but no association was identified between any of the measured variables and outcome. These findings are consistent with previous studies in animals with experimentally induced disease and in clinical studies of humans. On the basis of these results, further investigation of the role of AT and PC in canine sepsis is warranted. [source] Characterization of the pharmacokinetic disposition of levofloxacin in stallions after intravenous and intramuscular administrationJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 5 2008A. GOUDAH The target of the present study was to investigate the plasma disposition kinetics of levofloxacin in stallions (n = 6) following a single intravenous (i.v.) bolus or intramuscular (i.m.) injection at a dose rate of 4 mg/kg bwt, using a two-phase crossover design with 15 days as an interval period. Plasma samples were collected at appropriate times during a 48-h administration interval, and were analyzed using a microbiological assay method. The plasma levofloxacin disposition was best fitted to a two-compartment open model after i.v. dosing. The half-lives of distribution and elimination were 0.21 ± 0.13 and 2.58 ± 0.51 h, respectively. The volume of distribution at steady-state was 0.81 ± 0.26 L/kg, the total body clearance (Cltot) was 0.21 ± 0.18 L/h/kg, and the areas under the concentration,time curves (AUCs) were 18.79 ± 4.57 ,g.h/mL. Following i.m. administration, the mean t1/2el and AUC values were 2.94 ± 0.78 h and 17.21 ± 4.36 ,g.h/mL. The bioavailability was high (91.76% ± 12.68%), with a peak plasma mean concentration (Cmax) of 2.85 ± 0.89 ,g/mL attained at 1.56 ± 0.71 h (Tmax). The in vitro protein binding percentage was 27.84%. Calculation of efficacy predictors showed that levofloxacin might have a good therapeutic profile against Gram-negative and Gram-positive bacteria, with an MIC , 0.1 ,g/mL. [source] Comparison of plasma pharmacokinetics and bioequivalence of ceftiofur sodium in cattle after a single intramuscular or subcutaneous injectionJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 5 2000S. A. Brown Ceftiofur sodium, a broad-spectrum cephalosporin, is active against gram-positive and gram-negative pathogens of veterinary importance. This study was designed to compare the bioequivalence of the sodium salt in cattle after a single intramuscular (i.m.) or subcutaneous dose (s.c.) of 2.2 mg ceftiofur equivalents/kg body weight. The criteria used to evaluate bioequivalence were (1) the area under the curve from time of injection to the limit of quantitation (LOQ) of the assay (AUC0-LOQ), and (2) time concentrations remained above 0.2 ,g/mL (t>0.2). Twelve crossbred beef cattle were enrolled in a three-period, two-treatment crossover trial, with a minimum 2-week washout period between doses of 2.2 mg ceftiofur equivalents/kg. Blood samples were collected serially for up to 72 h post-injection. Plasma samples were then analyzed using a validated assay that measures ceftiofur, and all desfuroylceftiofur-related metabolites, by high-performance liquid chromatography (HPLC) as the stable derivative, desfuroylceftiofur acetamide. A maximum plasma concentration (Cmax) of 13.9±3.55 ,g/mL was observed from 0.67,2.0 h after i.m. administration, whereas a Cmax of 13.6±3.85 ,g/mL was observed from 0.67,3.0 h after s.c. administration. The AUC0-LOQ was 108±35.0 ,g · h/mL after i.m. dosing, compared with 105±29.8 ,g · h/mL after s.c. dosing. The pre-established criterion for equivalence of the AUC0-LOQ for the i.m. and s.c. routes of administration was satisfied. The t>0.2 was 49.2±8.55 h after i.m. administration, compared with 47.0±9.40 h after s.c. administration. The pre-established criterion for equivalence of the t>0.2 for i.m. and s.c. administration was satisfied. The equivalence of AUC0-LOQ and t>0.2 for i.m. and s.c. administration of 2.2 mg ceftiofur equivalents (CE)/kg doses of ceftiofur sodium suggest similar therapeutic efficacy and systemic safety for the two routes of administration. [source] Bioavailability of amprolium in fasting and nonfasting chickens after intravenous and oral administrationJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 1 2000Hamamoto The bioavailability of amprolium (APL) was measured after intravenous (i.v.) and oral (p.o.) administration to chickens. Twelve healthy chickens weighing 1.28,1.41 kg received a dose of 13 mg APL/kg intravenously, and 13 or 26 mg APL/kg orally in both a fasted and a nonfasted condition in a Latin square design. Plasma samples were taken from the subwing vein for determination of APL concentration by HPLC method. The data following intravenous and oral administration were best fitted by 2-compartment and 1-compartment models, respectively, using weighted nonlinear least squares regression. The half-life beta t½,, volume of distribution (Vd) and total body clearance (Cl) after intravenous administration were 0.21 h, 0.12 L/kg and 1.32 L/h.kg, respectively. The elimination half-life (t½ Kel) after oral administration was 0.292,0.654 h which is 1.5,3.2 times longer than after intravenous administration, suggesting the presence of a ,flip-flop' phenomenon in chickens. The maximum plasma concentration (Cmax) of 13 mg/kg APL administered orally to chickens during fasting was significantly (about four times) higher than that during nonfasting (P < 0.05). Bioavailability during nonfasting was from 2.3 to 2.6%, and 6.4% during fasting. [source] Prospective study of hemostatic alterations in children with acute lymphoblastic leukemia,AMERICAN JOURNAL OF HEMATOLOGY, Issue 5 2010Paola Giordano In a group of newly diagnosed acute lymphocytic leukemia (ALL) children we evaluated a number of hemostatic and inflammatory markers at diagnosis and at different time points during chemotherapy for the remission induction to identify alterations in the plasma levels of prothrombotic markers before and during the course of chemotherapy. The following plasma markers were evaluated: thrombin-antithrombin complex (TAT), D-Dimer, plasminogen activator inhibitor 1 (PAI-1), antithrombin, fibrinogen, von Willebrand factor (VWF) antigen and high molecular weight VWF (HMW-VWF) multimers, P-selectin, tumor necrosis factor alpha (TNF-,), and interleukin 6 (IL-6). Plasma samples were collected at the following time points: at T0 (baseline) and T1 (+24 days of therapy), T2 (+36 days therapy), and T3 (+64 days therapy). The results show that, at diagnosis, ALL children presented with laboratory signs of increased thrombin generation and fibrin formation (i.e. high TAT and D-dimer levels), fibrinolysis inhibition (i.e. high PAI-1 level), endothelial activation (i.e., high HMW-VWF and soluble P-selectin levels) and inflammation (i.e. high TNF-alpha and IL-6 levels). After starting induction therapy, the thrombin generation markers and inflammatory cytokines significantly decreased. To the opposite, PAI-1 and P-selectin significantly increased, suggesting an insult by chemotherapy on the vascular endothelium. These effects were more evident during steroid administration. Symptomatic venous thromboembolism (VTE) episodes developed in two cases during induction therapy, which did not allow the evaluation of the predictive value for VTE of laboratory markers. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc. [source] HPA axis safety of fluticasone furoate nasal spray once daily in children with perennial allergic rhinitisPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 3 2009Ita Tripathy The effects of intranasal corticosteroids (INSs) on the hypothalamic,pituitary,adrenal (HPA) axis should be assessed for any to be marketed INS. The objective of this study was to assess the effects of fluticasone furoate nasal spray (FFNS) on cortisol production (as a measure of HPA axis function) following 6 wk of treatment with FFNS 110 ,g once daily (QD) compared with placebo in pediatric patients with perennial allergic rhinitis (PAR). In this double-blind, parallel-group study, patients (n = 112) aged 2,11 yr with a 1-yr history of PAR (6 months for patients aged 2,3 yr) were randomized in a 1:1 ratio to either placebo or FFNS. Serum cortisol (SC) concentrations and urinary cortisol (UC) excretion were measured over a 24-h period at the randomization (baseline) and final treatment (week 6) visits for HPA axis evaluation in a domiciled environment (overnight in the clinic). Plasma samples were collected for FFNS at several time points over the 24 h after the final dose for pharmacokinetic analyses. FFNS was non-inferior to placebo with respect to change from baseline (expressed as a ratio) in 24-h SC weighted mean. The lower limit of the two-sided 95% confidence interval (CI) for the treatment ratio was greater than the pre-specified non-inferiority margin of 0.8 (treatment ratio = 0.97, 95% CI 0.88,1.07). UC excretion over 24 h at baseline and end of treatment was similar between treatment groups; no patients had 24-h excretion levels below normal range after 6 wk of treatment. Plasma concentrations of FFNS were generally non-quantifiable (<10 pg/ml). Results of the current study indicate that FFNS 110 ,g QD has no significant effect on HPA axis function in 2- to 11-yr-old pediatric patients with PAR. [source] Plasma-lead concentration: Investigations into its usefulness for biological monitoring of occupational lead exposureAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 2 2006Ingvar A. Bergdahl Abstract Background The lead concentration in plasma is correlated to that in whole blood with a two to fourfold variation. It has never been investigated if this variation is inter-individual. Methods Lead and hemoglobin were determined in blood and plasma from 13 lead workers with a history of relatively high blood-lead concentrations, sampled three times during 1 day. The variation in the distribution of lead between cells and plasma was studied, but not the variation in the lead concentrations as such. Results Blood hemoglobin decreased with rising plasma lead (0.9,3.0 µg/L). Regarding the distribution of lead, no effect of current exposure during the day or of recent meals appeared. As much as 84% of the overall variance of the distribution of lead between cells and plasma could be attributed to individual factors. After adjustment for erythrocyte volume fraction this decreased to 67%. Plasma samples with elevated hemoglobin concentrations (due to in vitro hemolysis) had somewhat elevated lead concentrations. Conclusions Plasma lead is not significantly altered by variation in a single day's exposure and, therefore, the choice of time of the day is not critical for sampling. However, plasma lead is negatively correlated to blood hemoglobin and mild hemolysis (not visible by the eye) in a sample may increase plasma lead with up to 30%. Finally, plasma provides lead exposure information that differs from whole blood, but it is not clear which one of these is the biomarker with the closest relation to exposure and/or effects. Am. J. Ind. Med. 49:93,101, 2006. © 2006 Wiley-Liss, Inc. [source] Determination of paclitaxel in human plasma following the administration of Genaxol or Genetaxyl by liquid chromatography/tandem mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 14 2006Erin R. Gardner A sensitive and specific assay for paclitaxel in plasma has been developed to overcome limitations in previously published assays, using liquid chromatography with tandem mass spectrometric detection. Plasma samples (100,µL) were subjected to liquid-liquid extraction with 1-chlorobutane/acetonitrile (4:1, v/v), with [2H5]paclitaxel employed as the internal standard. Chromatography was carried out with a Waters SymmetryShield C8 column (50,×,2.1 mm, 3.5,µm). The total run time, including equilibration, was 8 min, using a gradient of acetonitrile and 10,mM ammonium formate, pH 4.0. The assay is accurate and precise over the range of 2,2500,ng/mL and has been successfully applied to study the clinical pharmacokinetics of two formulations of paclitaxel, Genaxol and Genetaxyl, given orally and intravenously. Copyright © 2006 John Wiley & Sons, Ltd. [source] Genetic and plasma variation of insulin-like growth factor binding proteins in relation to prostate cancer incidence and survivalTHE PROSTATE, Issue 12 2009Mattias Johansson Abstract BACKGROUND Binding proteins regulate bioavailability of insulin-like growth factor-I (IGF-I) in the circulation and affect apoptosis of tumor cells in the prostate. We analyzed genetic variation within genes coding for IGF binding proteins in relation to prostate cancer incidence and survival. We also investigated if circulating IGFBP3 affects prostate cancer-specific survival. MATERIALS AND METHODS Eleven haplotype tagging SNPs and two single SNPs in the IGFBP1, IGFBP3, and IGFALS genes were genotyped within the CAncer Prostate in Sweden (CAPS) study including 2,774 cases and 1,736 controls. Plasma samples for analyses of total- and intact IGFBP3 levels were available for 1,521 cases and 909 controls. Complete follow-up of vital status was achieved by linkage to the Swedish Cause of Death Register. RESULTS We found no clear association between the genetic variants and prostate cancer incidence or survival. The rare allele of the IGFBP3 SNP rs2854744 was associated with elevated plasma levels of total IGFBP3 (Ptrend,=,9,×,10,8), but not intact IGFBP3 (Ptrend,=,0.16). Elevated levels of total- (Ptrend,=,0.03) and intact IGFBP3 (Ptrend,=,6,×,10,14) were associated with increased risk of prostate cancer specific death. Treatment and tumor characteristics accounted for the association with total IGFBP3, whereas the association with intact IGFBP3 was attenuated, but still statistically significant in adjusted analysis (Ptrend-adjusted,=,0.0004). Elevated intact IGFBP3 was also significantly associated with increased risk of prostate cancer-specific death among patients who were chemically or surgically castrated (Ptrend-adjusted,=,0.0003), and among patients who had not been treated (Ptrend-adjusted,=,0.02). CONCLUSIONS Circulating levels of intact IGFBP3 measured after diagnosis is associated with increased risk of prostate cancer-specific death. Prostate 69:1281,1291, 2009. © 2009 Wiley-Liss, Inc. [source] Antiangiogenic plasma activity in patients with systemic sclerosisARTHRITIS & RHEUMATISM, Issue 10 2007Mary Jo Mulligan-Kehoe Objective Systemic sclerosis (SSc; scleroderma) is a systemic connective tissue disease with an extensive vascular component that includes aberrant microvasculature and impaired wound healing. The aim of this study was to investigate the presence of antiangiogenic factors in patients with SSc. Methods Plasma samples were obtained from 30 patients with SSc and from 10 control patients without SSc. The samples were analyzed for the ability of plasma to affect endothelial cell migration and vascular structure formation and for the presence of antiangiogenic activity. Results Exposure of normal human microvascular dermal endothelial cells to plasma from patients with SSc resulted in decreased cell migration (mean ± SEM 52 ± 5%) and tube formation (34 ± 6%) compared with that in plasma from control patients (P < 0.001 for both). SSc plasma contained 2.9-fold more plasminogen kringle 1,3 fragments (angiostatin) than that in control plasma. The addition of angiostatin to control plasma resulted in inhibition of endothelial cell migration and proliferation similar to that observed in SSc plasma. In vitro studies demonstrated that granzyme B and other proteases contained in T cell granule content cleave plasminogen and plasmin into angiostatin fragments. Conclusion Plasminogen conformation in patients with SSc enables granzyme B and granule content protease to limit the proangiogenic effects of plasmin and increase the levels of antiangiogenic angiostatin. This increase in angiostatin production may account for some of the vascular defects observed in patients with SSc. [source] Preservation of Endothelium Nitric Oxide Release by Pulsatile Flow Cardiopulmonary Bypass When Compared With Continuous FlowARTIFICIAL ORGANS, Issue 11 2009Ettore Lanzarone Abstract The aim of this work is to analyze endothelium nitric oxide (NO) release in patients undergoing continuous or pulsatile flow cardiopulmonary bypass (CPB). Nine patients operated under continuous flow CPB, and nine patients on pulsatile flow CPB were enrolled. Plasma samples were withdrawn for the chemiluminescence detection of nitrite and nitrate. Moreover the cellular component was withdrawn for the detection of nitric oxide synthase (NOS) activity in the erythrocytes, and an estimation of systemic inflammatory response was carried out. Significant reduction in the intraoperative concentration with respect to the preoperative was observed only under continuous flow CPB for both nitrite and NOx (nitrite + nitrate) concentration (P = 0.010 and P = 0.016, respectively). Significant difference in intraoperative nitrite concentration was also observed between the groups (P = 0.012). Finally, erythrocytes showed a certain endothelial NOS activity, which did not differ between the groups, and no differences in the inflammatory response were pointed out. The significant reduction of NO2 - concentration under continuous perfusion revealed the strong connection among perfusion modality, endothelial NO release, and plasmatic nitrite concentration. The similar erythrocyte eNOS activity between the groups revealed that the differences in blood NO metabolites are mainly ascribable to the endothelium release. [source] SPE/RIA vs LC/MS for measurement of low levels of budesonide in plasmaBIOMEDICAL CHROMATOGRAPHY, Issue 1 2003H. Dimova Abstract A radioimmunoassay is described that measures budesonide in plasma after solid-phase extraction (SPE/RIA) of the analyte. The performance of the assay was compared with that of a selective LC/MS method. The limit of quantitation of budesonide determined for the LC/MS and SPE/RIA assay was 50,pg/mL and 120,pg/mL, respectively. Based on quality control samples, a higher variability was observed for the SPE/RIA (CV between 4.5 and 23.0%) than for the LC/MS method (CV between 7.5 and 12.5%). Plasma samples obtained from healthy volunteers after administration of budesonide rectal foam were assayed by both methods. In a subset of samples, these results were compared with those measured by direct RIA to evaluate the selectivity of two assays. About two times higher budesonide levels were measured with the direct RIA (lacking the extraction step), presumably because of cross-reactivity with budesonide metabolites, indicating that the extraction step in SPE/RIA is necessary for selectivity. Both SPE/RIA and LC/MS methods were found to be selective, sensitive and suitable for pharmacokinetic studies. Results obtained from the two methods were compared with a number of statistical methods. Ratios of results obtained for the clinical samples were close to 1 (ratio LC-MS/ SPE/RIA,=,0.98,±,0.27). Linear regression indicated a slope of 1.17,±,0.0378. The concordance correlation (r,=,0.91) indicated that the agreement between both methods was fair while the Bland,Altman plot indicated that the agreement was less pronounced at higher concentrations (1,3,ng/mL). In summary, the results confirm that the SPE/RIA is an alternative to HPLC/MS and that among the statistical methods tested the concordance correlation analysis was judged to be the most informative test to assess the comparability of two methods. Copyright © 2002 John Wiley & Sons, Ltd. [source] Effect of omeprazole on the pharmacokinetics of paricalcitol in healthy subjectsBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 2 2007Rameshraja Palaparthy Abstract Paricalcitol capsules are indicated for the prevention and treatment of secondary hyperparathyroidism in chronic kidney disease (CKD). Proton pump inhibitors are prescribed to CKD patients to treat gastroesophageal reflux. This was a single dose, crossover study evaluating the effect of omeprazole, change in gastric pH as a result thereof, on the pharmacokinetics (PK) of paricalcitol. Twenty-six healthy subjects were administered paricalcitol capsules (16 µg) alone (regimen A), and following a single dose of OMP (40 mg) (regimen B), with a washout of at least 7 days. Plasma samples for paricalcitol concentrations were collected for 48 h post-paricalcitol dose. The plasma paricalcitol concentrations were measured using an LC,MS/MS assay (LOQ=0.02 ng/ml) and paricalcitol pharmacokinetic parameters were estimated using non-compartmental methods. The point estimates and the corresponding 90% confidence intervals for Cmax and AUC0-, to evaluate paricalcitol,omeprazole interaction were 1.032 [0.920,1.158] and 1.041 [0.951,1.139], respectively. No significant differences in Tmax (regimen A: 2.9 h vs regimen B: 2.6 h) or t1/2 (6.83 h vs 6.6 h) between the regimens were observed. Hence, the co-administration of omeprazole does not affect the PK of paricalcitol. Both regimens were well tolerated and no apparent differences among the regimens with respect to safety were observed. Copyright © 2007 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||