Thiamine Whole Blood and Urinary Pharmacokinetics in Rats: Urethan-Induced Dose-Dependent Pharmacokinetics

1982 ◽  
Vol 71 (2) ◽  
pp. 169-172 ◽  
Author(s):  
J.D. Pipkin ◽  
V.J. Stella
Keyword(s):  
Whole Blood ◽  
Dose Dependent ◽  
Pharmacokinetics In Rats

Adenosine Diphosphate (ADP)-Induced ⍺-Granules Release from Platelets of Native Whole Blood Is Reduced by Ticlopidine but Not by Aspirin or Dipyridamole

1986 ◽  
Vol 56 (02) ◽  
pp. 147-150 ◽  
Author(s):  
V Pengo ◽  
M Boschello ◽  
A Marzari ◽  
M Baca ◽  
L Schivazappa ◽  
...  
Keyword(s):  
Whole Blood ◽  
Light Transmission ◽  
Ex Vivo ◽  
Early Stage ◽  
Shape Change ◽  
Adenosine Diphosphate ◽  
Dose Dependent ◽  
Plateletderived Growth Factor ◽  
Platelet Shape

SummaryA brief contact between native whole blood and ADP promotes a dose-dependent release of platelet a-granules without a fall in the platelet number. We assessed the “ex vivo” effect of three widely used antiplatelet drugs, aspirin dipyridamole and ticlopidine, on this system. Aspirin (a single 800 mg dose) and dipyridamole (300 mg/die for four days) had no effect, while ticlopidine (500 mg/die for four days) significantly reduced the a-granules release for an ADP stimulation of 0.4 (p <0.02), 1.2 (p <0.01) and 2 pM (p <0.01). No drug, however, completeley inhibits this early stage of platelet activation. The platelet release of α-granules may be related to platelet shape change of the light transmission aggregometer and may be important “in vivo” by enhancing platelet adhesiveness and by liberating the plateletderived growth factor.

Endotoxin-Induced Platelet Activation in Human Whole Blood In Vitro

1988 ◽  
Vol 59 (03) ◽  
pp. 378-382 ◽  
Author(s):  
Gyorgy Csako ◽  
Eva A Suba ◽  
Ronald J Elin
Keyword(s):  
Platelet Aggregation ◽  
Whole Blood ◽  
Human Platelet ◽  
Platelet Rich Plasma ◽  
Atp Release ◽  
Human Platelets ◽  
Lag Phase ◽  
Human Whole Blood ◽  
Dose Dependent

SummaryThe effect of purified bacterial endotoxin was studied on human platelets in vitro. In adding up to 1 μg/mL of a highly purified endotoxin, we found neither aggregation nor ATP release in heparinized or citrated human platelet-rich plasma. On the other hand, endotoxin at concentrations as low as a few ng/mL (as may be found in septic patients) caused platelet aggregation in both heparinized and citrated human whole blood, as monitored by change in impedance, free platelet count, and size. Unlike collagen, the platelet aggregation with endotoxin occurred after a long lag phase, developed slowly, and was rarely coupled with measurable release of ATP. The platelet aggregating effect of endotoxin was dose-dependent and modified by exposure of the endotoxin to ionizing radiation. Thus, the activation of human platelets by “solubilized” endotoxin in plasma requires the presence of other blood cells. We propose that the platelet effect is mediated by monocytes and/or neutrophils stimulated by endotoxin.

Chloroquine inhibits proinflammatory cytokine release into human whole blood

1998 ◽  
Vol 274 (4) ◽  
pp. R1058-R1064 ◽  
Author(s):  
Ina Karres ◽  
Jean-Pierre Kremer ◽  
Ingrid Dietl ◽  
Ursula Steckholzer ◽  
Marianne Jochum ◽  
...  
Keyword(s):  
Proinflammatory Cytokines ◽  
Whole Blood ◽  
Inhibitory Effect ◽  
Potential Effect ◽  
Therapeutic Benefit ◽  
Human Whole Blood ◽  
Weak Bases ◽  
Factor Α ◽  
Dose Dependent ◽  
Necrosis Factor

Excessive synthesis and release of proinflammatory cytokines during endotoxemia causes severe pathophysiological derangements and organ failure. Because the lysosomotropic agent chloroquine has been effective in the treatment of diseases associated with increased secretion of proinflammatory cytokines such as malaria or rheumatoid arthritis, this study evaluates the potential effect of chloroquine on endotoxin-induced cytokinemia using human whole blood from healthy volunteers. Chloroquine revealed a dose-dependent inhibitory effect on endotoxin-induced secretion of tumor necrosis factor-α, interleukin-1β, and interleukin-6 that was associated with reduced cytokine mRNA expression. Moreover, ammonia and methylamine, which react as weak bases like chloroquine, reduced synthesis and secretion of proinflammatory cytokines. These data indicate a potent anti-inflammatory effect of chloroquine on endotoxin-induced synthesis of proinflammatory cytokines that may be due to its weak base effect. Thus chloroquine may be of therapeutic benefit not only during chronic inflammation but also in diseases that are related to bacteria-induced inflammation.

Novel Concentration-Dependent Roles for Heparin in Modifying LPS-Induced Activation of Mononuclear Cells in Whole Blood.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 927-927
Author(s):  
Helene Hochart ◽  
Vince Jenkins ◽  
Owen P. Smith ◽  
Barry White ◽  
James O’Donnell
Keyword(s):  
Whole Blood ◽  
Mononuclear Cells ◽  
Inflammatory Responses ◽  
Ex Vivo ◽  
Anticoagulant Activity ◽  
Serum Free ◽  
Anti Inflammatory ◽  
Serum Free Conditions ◽  
Dose Dependent ◽  
Stimulation Of

Abstract Background: In addition to their etsblished anticoagulant activity, unfractionated heparin (UFH) and low molecular weight heparin (LMWH) are known to possess clinically important immuno-modulatory properties. However different studies have reported conflicting pro- and anti-inflammatory effects in association with heparin. Moreover, the molecular basis for these heparin effects on inflammation remains unclear. In view of the wide and diverse clinical indications for heparin, it is clearly of direct translational relevance to define how UFH and LMWH differentially regulate inflammatory responses to LPS in-vivo. Objectives: To determine how UFH and LMWH regulate lipopolysaccharide (LPS)-induced activation of human mononuclear cells in whole blood, and define the role of lipopolysaccharide binding protein (LBP) in mediating this effect. Methods: Whole blood was pre-treated with UFH or LMWH (0.1–200 IU/ml), prior to stimulation with LPS (10ng/ml). After 6 hours, monocyte pro-inflammatory cytokine (interleukin (IL)-1b, IL-6, IL-8, and TNF-a) secretion was determined by plasma ELISA. Parallel experiments using THP-1 cell line and primary monocytes were performed under serum-free conditions, in the presence or absence of varying doses of recombinant human LBP (range: 50–100nM). Results: Under serum-free conditions, heparin demonstrated dose-dependent anti -inflammatory effects, significantly reducing secretion of pro-inflammatory cytokines (IL-1b, IL-6, IL-8, and TNF-a) in response to LPS-stimulation of THP-1 cells and primary monocytes. In contrast, in the presence of LBP, both UFH and LMWH demonstrated dose-dependent pro-inflammatory effects at all heparin concentrations. In ex-vivo whole blood experiments, pro-inflammatory effects (increased IL-1b and IL-8 following LPS-stimulation) of heparin were also observed, but only at supra-therapeutic doses (10–200IU/ml). Conclusion: In keeping with previous reports, we have demonstrated that both UFH and LMWH can significantly down-regulate cytokine (TNF-a, IL-1b, IL-6 and IL-8) secretion in response to LPS-activation in-vitro. However our novel data demonstrate that the effect of heparin on monocyte activation by LPS is significantly more complex in the setting of whole blood. Firstly, in contrast to the anti-inflammatory effects observed under serum-free conditions, we found that in whole blood, high concentrations of heparin exerted marked pro-inflammatory effects. Secondly we have also demonstrated that the effects of heparin in whole blood are entirely dependent upon heparin concentration and LBP concentration.

Native Whole Blood Thrombin Generation Assay Evaluates Therapeutic Efficacy Of Plasma and Platelet-Derived FVIII

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1093-1093
Author(s):  
Christina K Baumgartner ◽  
Qizhen Shi ◽  
Robert R. Montgomery
Keyword(s):  
Gene Therapy ◽  
Replacement Therapy ◽  
Whole Blood ◽  
Therapeutic Efficacy ◽  
Thrombin Generation ◽  
Generation Rate ◽  
Gene Therapy Approach ◽  
Thrombin Generation Assay ◽  
Recombinant Fviii ◽  
Dose Dependent

Abstract Factor VIII (FVIII) gene therapy is a promising approach to potentially permanently and cost-effectively correct the bleeding phenotype of hemophilia A patients and improve patients quality of life. Our group has developed a successful gene therapy approach in which FVIII expression is targeted to platelets. Platelet expressed FVIII protects hemophilic mice from lethal blood loss after vessel injury. Most importantly this therapy does not induce FVIII inhibitory antibodies and is even successful in the treatment of mice with pre-existing high titer inhibitors. Therefore this approach is among the first to hold promise for patients who develop inhibitory antibodies against FVIII that render FVIII replacement therapy ineffective. Levels of platelet expressed FVIII achieved by gene therapy may vary between individuals due to differences in ex vivotransduction and gene expression efficiency. We determined hemostatic efficacy over a wide therapeutic dose range with a novel native whole blood thrombin generation assay. Tracking the correction of abnormal bleeding phenotypes during the treatment of patients with hemostatic disorders is crucial to evaluate success of therapy. Global coagulation assays in contrast to single clotting factor assays are desirable to better understand the overall hemostatic condition of patients. Here we evaluated thrombin generation using a modified protocol of a recently described whole blood assay. In our native assay we initiated coagulation without the addition of tissue factor. Sole recalcification of whole blood resulted in thrombin generation with high reproducibility. Lag time (LT) determined in blood from C57BL/6 WT mice was 6 ± 0.2 min (Mean ± SEM) , thrombin generation rate was 58 ± 6 nM/min and thrombin peak was 188 ± 7 nM. In contrast, FVIII deficient blood had negligible thrombin generation with 39 ± 7 min LT, 1.4 ± 0.3 nM/min thrombin generation rate and 12 ± 3 nM thrombin peak. Spiking hemophilic blood with increasing concentrations of recombinant FVIII ex vivo resulted in a dose dependent increase in thrombin generation. Reconstitution of hemophilic blood with FVIII to a 1%, 10% and 100% level shortened LT to 19 ± 1, 12 ± 0.3 and 9 ± 0.5 min, respectively. To evaluate efficacy of platelet-derived FVIII we utilized a newly developed transgenic mouse model that expresses high levels of FVIII in platelets. Homozygous mice express platelet FVIII levels corresponding to 20% endogenous FVIII in whole blood. We combined different ratios of FVIII deficient blood with blood from platelet FVIII expressing transgenic mice. At low ratios of transgenic blood, similar to ex vivospiking with recombinant FVIII, thrombin generation parameters were dose-dependent. Remarkably, a corresponding dose of as low as 0.2% platelet-derived FVIII significantly elevated thrombin generation above FVIII deficient blood and had comparable therapeutic efficacy as a 5-fold higher dose of recombinant FVIII (LT, 18 ± 2 vs 19 ± 1). Similarly, efficacy of 1.5% of platelet-derived FVIII compared with the 6.7-fold higher, 10% dose of recombinant FVIII (LT, 13 ± 1 vs 12 ± 0.3). Further increase of thrombin generation was noticed with platelet FVIII expressing transgenic blood ratios corresponding to 2% and 5% FVIII levels (LT, 11 ± 0.3 and 8.7 ± 0.3 min, respectively). Interestingly, our native assay showed that the platelet FVIII expressing transgenic blood ratio corresponding to a FVIII level of only 5% was sufficient to induce maximal thrombin generation, similar to that obtained with undiluted transgenic blood (LT, 8.7 ± 0.6 min). A similar FVIII dose-dependency was identified for additional thrombin generation parameters including endogenous thrombin potential, thrombin peak, peak time and thrombin generation rate. We conclude that this native whole blood thrombin generation assay could be used to track therapeutic efficacy of hemophilia A treatment. Using this assay, our data indicate that similar to FVIII replacement therapy our previously established platelet targeted FVIII gene therapy approach enhances hemostasis over a wide therapeutic dose level. This is of great importance because levels of platelet expressed FVIII achieved upon gene therapy in mice vary. In agreement with our previous reports our data from native whole blood thrombin generation assay confirm that at lower FVIII dose levels platelet targeted FVIII gene therapy might be more efficient than factor replacement therapy. Disclosures: No relevant conflicts of interest to declare.

Quantifying manganese in lymphocytes to assess manganese nutritional status.

1989 ◽  
Vol 35 (9) ◽  
pp. 1939-1941 ◽  
Author(s):  
A Matsuda ◽  
M Kimura ◽  
M Kataoka ◽  
S Ohkuma ◽  
M Sato ◽  
...  
Keyword(s):  
Nutritional Status ◽  
Intravenous Injection ◽  
Whole Blood ◽  
Manganese Concentration ◽  
Dependent Manner ◽  
Dose Dependent ◽  
Better Than ◽  
Manganese Concentrations

Abstract To clarify whether manganese nutritional status is better reflected by the manganese concentration in lymphocytes or in whole blood, we injected manganese solutions intravenously into manganese-deficient rats and determined manganese concentrations in lymphocytes, whole blood, and various tissues. The manganese concentrations in lymphocytes and tissues, but not in whole blood, were significantly less in manganese-deficient rats than in normal rats. These low values could be prevented by intravenous injection of manganese in a dose-dependent manner. These results suggest that, for assessment of manganese nutritional status, measurement of manganese in lymphocytes is better than that in whole blood.

Sign in / Sign up

Export Citation Format

Share Document