scholarly journals ALTERATIONS IN THE BLOOD COAGULATION SYSTEM INDUCED BY BACTERIAL ENDOTOXINS

1958 ◽  
Vol 107 (3) ◽  
pp. 369-376 ◽  
Author(s):  
Donald G. McKay ◽  
Sandor S. Shapiro ◽  
Jacob N. Shanberge

Bacterial endotoxins in vitro are capable of shortening the coagulation time of normal whole blood, native platelet-rich and platelet-poor plasma, and the blood of a hemophilic patient in silicone but not in glass. The point in the coagulation system at which the endotoxins act has not been found but the search has been narrowed by the demonstration that these materials act independently of leukocytes and red blood cells, and do not act as preformed thromboplastin or thrombin. The shortening of the coagulation time in vivo 4 hours after endotoxin injection is probably through a different mechanism than in vitro.

2014 ◽  
Vol 111 (03) ◽  
pp. 447-457 ◽  
Author(s):  
Marisa Ninivaggi ◽  
Gerhardus Kuiper ◽  
Marco Marcus ◽  
Hugo ten Cate ◽  
Marcus Lancé ◽  
...  

SummaryBlood dilution after transfusion fluids leads to diminished coagulant activity monitored by rotational thromboelastometry, assessing elastic fibrin clot formation, or by thrombin generation testing. We aimed to determine the contributions of blood cells (platelets, red blood cells) and plasma factors (fibrinogen, prothrombin complex concentrate) to fibrin clot formation under conditions of haemodilution in vitro or in vivo. Whole blood or plasma diluted in vitro was supplemented with platelets, red cells, fibrinogen or prothrombin complex concentrate (PCC). Thromboelastometry was measured in whole blood as well as plasma; thrombin generation was determined in parallel. Similar tests were performed with blood from 48 patients, obtained before and after massive fluid infusion during cardiothoracic surgery. Addition of platelets or fibrinogen, in additive and independent ways, reversed the impaired fibrin clot formation (thromboelastometry) in diluted whole blood. In contrast, supplementation of red blood cells or prothrombin complex concentrate was ineffective. Platelets and fibrinogen independently restored clot formation in diluted plasma, resulting in thromboelastometry curves approaching those in whole blood. In whole blood from patients undergoing dilution during surgery, elastic clot formation was determined by both the platelet count and the fibrinogen level. Thrombin generation in diluted (patient) plasma was not changed by fibrinogen, but improved markedly by prothrombin complex concentrate. In conclusion, in dilutional coagulopathy, platelets and fibrinogen, but not red blood cells or vitamin K-dependent coagulation factors, independently determine thromboelastometry parameters measured in whole blood and plasma. Clinical decisions for transfusion based on thromboelastometry should take into account the platelet concentration.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Seán Fitzgerald ◽  
Daying Dai ◽  
Andrew S Douglas ◽  
Oana M Mereuta ◽  
Thomas Caracena ◽  
...  

Introduction: Previous studies have successfully created blood clot analogues for In-vitro testing using animal blood. Blood components vary greatly among species and thus, creating clot analogues with human blood is likely a more accurate representation of thrombi formed in the human vasculature. We present a novel method of creating clot analogues from human blood and platelets that mimic the process by which clots form In-vivo . Methods: Following IRB approval from Mayo Clinic, human whole blood and platelets donations were obtained from the Blood Transfusion service. The whole blood was centrifuged at 1,200RPM for 20 minutes to separate it into its constituents. Plasma was removed and the remaining Red Blood Cells and Buffy Coat were mixed together by inverting. A total of 12 clot analogues were created with varying concentrations of components; Red Blood cells/Buffy Coat, Plasma and Platelets. Thrombin was added first to stimulate platelets activation for a total of 5 mins whilst continuously mixing by inversion. The RBC/WBC mixture was added next followed by CaCl2. The mixture was then quickly drawn into a 3cc syringe and spun overnight at 20RPM at room temperature to mimic dynamic flow conditions. Macro-photographs were taken to display the variation in texture and color between different clot analogue types. The clots were then fixed in 10% neutral buffered formalin for 24 hours prior to being processed. Histopathological analysis was performed using Hematoxylin and Eosin (H&E) and Martius Scarlet Blue (MSB) staining to confirm clot composition. Results: Red Blood cell-rich, Fibrin-rich, Platelet-rich and mixed clot analogues that accurately mimic clots retrieved from Acute Ischemic Stroke Patients were created. The range of histopathological compositions of the clot analogues is similar to that of the clinical samples. Conclusions: The addition and activation of platelets is key to creating accurate clot analogues for In-vitro testing. Spinning the clots is important to prevent natural sedimentation and mimic the In-vivo situation.


1959 ◽  
Vol 109 (1) ◽  
pp. 1-8 ◽  
Author(s):  
John Robbins ◽  
Chandler A. Stetson

Each of several antigen-antibody systems studied has been found to affect the coagulation mechanism in the rabbit, causing a marked shortening of the coagulation time in vitro of samples of whole blood maintained in siliconized glassware. Addition of specific antigen to the blood of actively immunized animals or addition of antigen-antibody mixtures to the blood of normal animals produced the effect. The coagulation time of plasma was not affected, indicating that the phenomenon may be mediated by an effect on platelets. This effect of antigen-antibody interaction may be involved in the production of tissue damage in vivo.


Author(s):  
D.J.P. Ferguson ◽  
A.R. Berendt ◽  
J. Tansey ◽  
K. Marsh ◽  
C.I. Newbold

In human malaria, the most serious clinical manifestation is cerebral malaria (CM) due to infection with Plasmodium falciparum. The pathology of CM is thought to relate to the fact that red blood cells containing mature forms of the parasite (PRBC) cytoadhere or sequester to post capillary venules of various tissues including the brain. This in vivo phenomenon has been studied in vitro by examining the cytoadherence of PRBCs to various cell types and purified proteins. To date, three Ijiost receptor molecules have been identified; CD36, ICAM-1 and thrombospondin. The specific changes in the PRBC membrane which mediate cytoadherence are less well understood, but they include the sub-membranous deposition of electron-dense material resulting in surface deformations called knobs. Knobs were thought to be essential for cytoadherence, lput recent work has shown that certain knob-negative (K-) lines can cytoadhere. In the present study, we have used electron microscopy to re-examine the interactions between K+ PRBCs and both C32 amelanotic melanoma cells and human umbilical vein endothelial cells (HUVEC).We confirm previous data demonstrating that C32 cells possess numerous microvilli which adhere to the PRBC, mainly via the knobs (Fig. 1). In contrast, the HUVEC were relatively smooth and the PRBCs appeared partially flattened onto the cell surface (Fig. 2). Furthermore, many of the PRBCs exhibited an invagination of the limiting membrane in the attachment zone, often containing a cytoplasmic process from the endothelial cell (Fig. 2).


Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Anastasia Maslianitsyna ◽  
Petr Ermolinskiy ◽  
Andrei Lugovtsov ◽  
Alexandra Pigurenko ◽  
Maria Sasonko ◽  
...  

Coronary heart disease (CHD) has serious implications for human health and needs to be diagnosed as early as possible. In this article in vivo and in vitro optical methods are used to study blood properties related to the aggregation of red blood cells in patients with CHD and comorbidities such as type 2 diabetes mellitus (T2DM). The results show not only a significant difference of the aggregation in patients compared to healthy people, but also a correspondence between in vivo and in vitro parameters. Red blood cells aggregate in CHD patients faster and more numerously; in particular the aggregation index increases by 20 ± 7%. The presence of T2DM also significantly elevates aggregation in CHD patients. This work demonstrates multimodal diagnostics and monitoring of patients with socially significant pathologies.


2021 ◽  
Author(s):  
Andrew D. Beale ◽  
Priya Crosby ◽  
Utham K. Valekunja ◽  
Rachel S. Edgar ◽  
Johanna E. Chesham ◽  
...  

AbstractCellular circadian rhythms confer daily temporal organisation upon behaviour and physiology that is fundamental to human health and disease. Rhythms are present in red blood cells (RBCs), the most abundant cell type in the body. Being naturally anucleate, RBC circadian rhythms share key elements of post-translational, but not transcriptional, regulation with other cell types. The physiological function and developmental regulation of RBC circadian rhythms is poorly understood, however, partly due to the small number of appropriate techniques available. Here, we extend the RBC circadian toolkit with a novel biochemical assay for haemoglobin oxidation status, termed “Bloody Blotting”. Our approach relies on a redox-sensitive covalent haem-haemoglobin linkage that forms during cell lysis. Formation of this linkage exhibits daily rhythms in vitro, which are unaffected by mutations that affect the timing of circadian rhythms in nucleated cells. In vivo, haemoglobin oxidation rhythms demonstrate daily variation in the oxygen-carrying and nitrite reductase capacity of the blood, and are seen in human subjects under controlled laboratory conditions as well as in freely-behaving humans. These results extend our molecular understanding of RBC circadian rhythms and suggest they serve an important physiological role in gas transport.


2017 ◽  
Vol 117 (07) ◽  
pp. 1402-1411 ◽  
Author(s):  
Laura Beth Mann Dosier ◽  
Vikram J. Premkumar ◽  
Hongmei Zhu ◽  
Izzet Akosman ◽  
Michael F. Wempe ◽  
...  

SummaryThe system L neutral amino acid transporter (LAT; LAT1, LAT2, LAT3, or LAT4) has multiple functions in human biology, including the cellular import of S-nitrosothiols (SNOs), biologically active derivatives of nitric oxide (NO). SNO formation by haemoglobin within red blood cells (RBC) has been studied, but the conduit whereby a SNO leaves the RBC remains unidentified. Here we hypothesised that SNO export by RBCs may also depend on LAT activity, and investigated the role of RBC LAT in modulating SNO-sensitive RBC-endothelial cell (EC) adhesion. We used multiple pharmacologic inhibitors of LAT in vitro and in vivo to test the role of LAT in SNO export from RBCs and in thereby modulating RBC-EC adhesion. Inhibition of human RBC LAT by type-1-specific or nonspecific LAT antagonists increased RBC-endothelial adhesivity in vitro, and LAT inhibitors tended to increase post-transfusion RBC sequestration in the lung and decreased oxygenation in vivo. A LAT1-specific inhibitor attenuated SNO export from RBCs, and we demonstrated LAT1 in RBC membranes and LAT1 mRNA in reticulocytes. The proadhesive effects of inhibiting LAT1 could be overcome by supplemental L-CSNO (S-nitroso-L-cysteine), but not D-CSNO or L-Cys, and suggest a basal anti-adhesive role for stereospecific intercellular SNO transport. This study reveals for the first time a novel role of LAT1 in the export of SNOs from RBCs to prevent their adhesion to ECs. The findings have implications for the mechanisms of intercellular SNO signalling, and for thrombosis, sickle cell disease, and post-storage RBC transfusion, when RBC adhesivity is increased.


2010 ◽  
Vol 53 (3) ◽  
pp. 575-582 ◽  
Author(s):  
Jacques Natan Grinapel Frydman ◽  
Adenilson de Souza da Fonseca ◽  
Vanessa Câmara da Rocha ◽  
Monica Oliveira Benarroz ◽  
Gabrielle de Souza Rocha ◽  
...  

This work evaluated the effect of in vitro and in vivo treatment with ASA on the morphology of the red blood cells. Blood samples or Wistar rats were treated with ASA for one hour. Blood samples or animals treated with saline were used as control group. Blood smears were prepared, fixed, stained and the qualitative and quantitative morphology of red blood cells were evaluated under optical microscopy. Data showed that the in vitro treatment for one hour with ASA at higher dose used significantly (p<0.05) modified the perimeter/area ratio of the red blood cells. No morphological alterations were obtained with the in vivo treatment. ASA use at highest doses could interfere on shape of red blood cells.


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