Hypoxia alters blood coagulation during acute decompression in humans

1984 ◽  
Vol 56 (3) ◽  
pp. 666-670 ◽  
Author(s):  
H. M. O'Brodovich ◽  
M. Andrew ◽  
G. W. Gray ◽  
G. Coates
Keyword(s):  
Molecular Weight ◽  
Platelet Count ◽  
Blood Coagulation ◽  
High Molecular Weight ◽  
Plasma Protein ◽  
Partial Thromboplastin Time ◽  
Activated Partial Thromboplastin Time ◽  
Total Plasma ◽  
High Molecular Weight Kininogen ◽  
Total Plasma Protein

Acute decompression is associated with a shortening of the activated partial thromboplastin time (aPTT). This study was performed to examine whether this change in aPTT results from hypoxia or hypobaria. We exposed healthy adults on three separate occasions to 2 h of 1) hypoxic hypobaria (410 Torr, n = 5), 2) hypoxic normobaria (fractional inspired O2 tension = 0.11, n = 4), or 3) normoxic hypobaria (410 Torr breathing supplemental O2, n = 5). The aPTT shortened during hypoxic hypobaria and hypoxic normobaria (P less than 0.05) but was unchanged during normoxic hypobaria. The prothrombin and thrombin times, hematocrit, and concentrations of fibrinogen, total plasma protein, and fibrinogen-fibrin fragment E were unchanged. During hypoxic hypobaria biologic levels of prekallikrein, high-molecular-weight kininogen, and factors XII, XI, X, VII, V, and II were unchanged, but procoagulant VIII (VIII:C) increased 50% without an increase in VIII-related antigen levels (VIIIR:Ag). Fibrin monomer was not detected in any group. In one subject who became ill after 1.5 h of hypoxic normobaria aPTT shortened by 10 s; the platelet count decreased by 93,000/mm3; VIII:C increased fivefold, but VIIIR:Ag only increased three-fold. We conclude that it is the hypoxia which shortens aPTT during acute decompression to 410 Torr and speculate that it results from an increase in plasma VIII:C-like activity.

The Contact Phase of Blood Coagulation in Diabetes Mellitus and in Patients with Vasculopathy

1984 ◽  
Vol 52 (03) ◽  
pp. 221-223 ◽  
Author(s):  
M Christe ◽  
P Gattlen ◽  
J Fritschi ◽  
B Lämmle ◽  
W Berger ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Molecular Weight ◽  
Blood Coagulation ◽  
High Molecular Weight ◽  
Negative Correlation ◽  
Factor Xii ◽  
C1 Inhibitor ◽  
High Molecular Weight Kininogen ◽  
Contact Phase ◽  
Α2 Macroglobulin

SummaryThe contact phase has been studied in diabetics and patients with macroangiopathy. Factor XII and high molecular weight kininogen (HMWK) are normal. C1-inhibitor and also α2-macroglobulin are significantly elevated in diabetics with complications, for α1-macroglobulin especially in patients with nephropathy, 137.5% ± 36.0 (p <0.001). C1-inhibitor is also increased in vasculopathy without diabetes 113.2 ± 22.1 (p <0.01).Prekallikrein (PK) is increased in all patients’ groups (Table 2) as compared to normals. PK is particularly high (134% ± 32) in 5 diabetics without macroangiopathy but with sensomotor neuropathy. This difference is remarkable because of the older age of diabetics and the negative correlation of PK with age in normals.

Surface Independent Factor XI Activation by Thrombin in the Presence of High Molecular Weight Kininogen

1994 ◽  
Vol 72 (03) ◽  
pp. 397-402 ◽  
Author(s):  
Peter A Kr von dem Borne ◽  
Stefan J Koppelman ◽  
Bonno N Bouma ◽  
Joost C M Meijers
Keyword(s):  
Molecular Weight ◽  
Blood Coagulation ◽  
High Molecular Weight ◽  
Dextran Sulfate ◽  
Factor Xa ◽  
Factor X ◽  
High Molecular Weight Kininogen ◽  
Factor Xi ◽  
Factor Xia

SummaryA deficiency of one of the proteins of the contact system of blood coagulation does not result in a bleeding disorder. For this reason activation of blood coagulation via this system is believed to be an in vitro artefact. However, patients deficient in factor XI do suffer from variable bleeding abnormalities. Recently, an alternative pathway for factor XI activation has been described. Factor XI was found to be activated by thrombin in the presence of dextran sulfate as a surface. However, high molecular weight kininogen (HK), to which factor XI is bound in plasma, and fibrinogen were shown to block this activation suggesting it to be an in vitro phenomenon. We investigated the thrombin-mediated factor XI activation using an amplified detection system consisting of factors IX, VIII and X, which was shown to be very sensitive for factor XIa activity. This assay is approximately 4 to 5 orders of magnitude more sensitive than the normal factor XIa activity assay using a chromogenic substrate. With this assay we found that factor XI activation by thrombin could take place in the absence of dextran sulfate. The initial activation rate was approximately 0.3 pM/min (using 25 nM factor XI and 10 nM thrombin). The presence of dextran sulfate enhanced this rate about 8500-fold. A very rapid and complete factor X activation was observed in the presence of dextran sulfate. Although only minute amounts of factor XIa were formed in the absence of dextran sulfate, significant activation of factor X was detected in the amplification assay within a few minutes. HK inhibited the activation of factor XI by thrombin strongly in the presence, yet only slightly in the absence of dextran sulfate (26 and 1.2 times, respectively). Despite the strong inhibition of HK on the activation of factor XI by thrombin in the presence of dextran sulfate, HK had only a minor effect on the factor Xa generation.We conclude that activation of factor XI by thrombin can take place regardless of the presence of a surface or HK. This activation might therefore be physiologically relevant. The inhibitory effect of HK on the thrombin-mediated factor XI activation is largely dextran sulfate dependent. Due to the amplification in the intrinsic system, trace amounts of factor XIa might generate physiological sufficient amounts of factor Xa for an adequate haemostatic response.

Studies on Fletcher trait and Fitzgerald trait

2010 ◽  
Vol 104 (11) ◽  
pp. 867-874 ◽  
Author(s):  
Hidehiko Saito
Keyword(s):  
Molecular Weight ◽  
Blood Coagulation ◽  
High Molecular Weight ◽  
Intimate Relationships ◽  
High Molecular Weight Kininogen ◽  
Rare Disorders ◽  
Defense Reactions ◽  
Foreign Surface ◽  
Fletcher Factor ◽  
Generating System

SummaryThe way by which contact of blood with foreign surface accelerates clotting has been elucidated from the discovery of four rare disorders of blood coagulation; Hageman trait, plasma thromboplastin antecedent (PTA) deficiency, Fletcher trait, and Fitzgerald trait. Interestingly, it was unexpectedly found that Fletcher factor is plasma prekallikrein and Fitzgerald factor is high-molecular-weight kininogen; components of the kinin-generating system, thus disclosing intimate relationships among clotting, fibrinolysis and kinin generation which may be viewed as body’s defense reactions against injury. This review mainly reflects our research on Fletcher trait and Fitzgerald trait during the 1970s in Cleveland.

Factor XI and Protection of the Fibrin Clot against Lysis – a Role for the Intrinsic Pathway of Coagulation in Fibrinolysis

1998 ◽  
Vol 80 (07) ◽  
pp. 24-27 ◽  
Author(s):  
Peter von dem Borne ◽  
Joost Meijers ◽  
Bonno Bouma
Keyword(s):  
Molecular Weight ◽  
Blood Coagulation ◽  
High Molecular Weight ◽  
Fibrin Clot ◽  
Contact System ◽  
Activate Factor ◽  
Factor Xii ◽  
High Molecular Weight Kininogen ◽  
Intrinsic Pathway ◽  
Factor Xi

IntroducationBlood coagulation is an important mechanism that maintains the integrity of the vascular system to prevent blood loss after injury. The conceptions on the working mechanism of coagulation are based on the waterfall or cascade model, which was already proposed more than 30 years ago, independently by Davie and Ratnoff (1) and MacFarlane (2). Blood coagulation was viewed as a series of linked proteolytic reactions in which zymogens are converted into serine proteases, ultimately leading to the formation of thrombin, which converts soluble fibrinogen into insoluble fibrin. Coagulation was thought to proceed via two pathways, an extrinsic and an intrinsic pathway. Activation of the extrinsic pathway of coagulation occurs by the exposition of tissue factor at the site of injury (3) whereas the intrinsic system is activated after exposure of plasma to an activating surface. Although the in vivo activating surface is unknown, the contact system was believed to play a role in the initiation of the intrinsic pathway. This system consists of factor XII, prekallikrein, high molecular weight kininogen and factor XI. The physiological relevance of the contact system is unclear, since a deficiency of factor XII, prekallikrein or high molecular weight kininogen does not result in a bleeding disorder. In contrast, patients deficient in factor XI, most common among Ashkenazi Jews, do suffer from variable bleeding abnormalities especially from tissues with high local fibrinolytic activity (urinary tract, nose, oral cavity, tonsils) (4, 5). This suggested there was an alternative route for the activation of factor XI, and recently such a route was described (6, 7). Thrombin was found to activate factor XI, even in the absence of a negatively charged surface (6-11), and factor XI was shown to play a role in the protection of the fibrin clot against lysis (9). In plasma the possibility cannot be excluded that the activation of factor XI by thrombin takes place via an intermediary component. Recently, it was shown that meizothrombin was capable of activating factor XI (12).

scholarly journals Cardiorespiratory and haematologicalparameters of healthy french bulldogs

2021 ◽  
Vol 17 (3) ◽  
pp. 83-88
Author(s):  
Vinícius dos Santos Rosa ◽  
Thais Caroline da Silva Santos ◽  
Felipe Franco Nascimento ◽  
João Victor Goulart Consoni Passareli ◽  
Claudia Lizandra Ricci ◽  
...  
Keyword(s):  
Heart Rate ◽  
Platelet Count ◽  
Respiratory Rate ◽  
Plasma Protein ◽  
Normal Values ◽  
Blood Platelet ◽  
Haematological Parameters ◽  
Total Plasma ◽  
Total Plasma Protein ◽  
Blood Platelet Count

Brachycephalic dogs have a normal lower jaw and a receded upper jaw, and these dogs are predisposed to nostril stenosis, elongated palate, tracheal hypoplasia and hyperthermia due to heat stress. Giventhese characteristics, these dogs are more predisposed to respiratory and cardiovascular disorders. The popularity of brachycephalic dogsthathave a greatertendency for cardiorespiratory disorders, such as French bulldogs,has increased recently; however, studies on the cardiorespiratoryand haematological parameters in this breedare lacking. Thus, the present study sought to evaluatethe cardiorespiratory and haematological parameters of healthy French bulldogs to standardize normal values forthisbreed. Thirty-six French bulldogs wereused without predilection for age or sex, and the following parameters were evaluated: temperature (T), heart rate (HR), respiratory rate (RR), erythrogram, leukogram, total plasma protein, plasmatic fibrinogen, blood platelet count, urea, creatinine, alkaline phosphatase (AP) and alanine aminotransferase (ALT). The mean and standard deviation wereas follows: T°C (38.3±0.4), HR (111.1±27.0) beats per minute, RR (54.8±32.5) breaths per minute, erythrocyte count (7.3±1.2x106), haemoglobin (16.9±2.8 g/dL), haematocrit (48.9±7.7%), MCV (67.6±2.4fL), MCH (23.3±0.7 pg), MCHC (34.6±0.8%), RDW-CV (9.3±0.9; 9.2-12.0%), total leukocytes (11009.7±2907.3/mm3), band neutrophils (250.0±260.4/mm3), segmented neutrophils (7094.4±2307.3/mm3), eosinophils (589.7±561.3/mm3), lymphocytes (2020.8±1457.5/mm3), monocytes (987.6±528.4/mm3), total plasma protein (6.9±0.5 g/dL), plasmatic fibrinogen (274.1±96.5 mg/dL), blood platelet count (366.4±88.5/mm3), urea (35.2±12.6 mg/dL), creatinine (0.8±0.2/mg/dL), AP (49.1±25.8U/L),ALT (36.2±12.3U/L). The haematological parameters and heart rate were within the normal values for the species, but the respiratory rate values (54.8±32.5 breaths per minute)were greater than the normal averageof10 to 30 breaths per minute. We conclude thatthehaematological parameters and heart rateof healthy French bulldogs arewithin the normal limit for dogs; however, the respiratory rate is above referencevalues, reinforcing the notion that dogs of this breed, although healthy,exhibitan increasedrisk of respiratory disorders

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