Comparison of One Stage and Two Stage Factor VIII Activity Assays in Healthy and Sick Subjects

1979 ◽  
Author(s):  
W.E. Hathaway ◽  
R.R. Montgomery
Keyword(s):  
Factor Viii ◽  
Generation Time ◽  
Metabolic Diseases ◽  
Cell Disease ◽  
Factor Viii Activity ◽  
The Past ◽  
Uremic Syndrome ◽  
Method Of Measurement ◽  
Expected Values ◽  
Clinical Conditions

For the past several years, factor VIII assays have been performed on the same sample of plasma by the partial thromboplastin time method (PTT-VIII) and the thromboplastin generation time method (TGT-VIII) in a variety of clinical conditions. Mean (range) values for representative subject groups are given.The methods compare well in inflammatory and metabolic diseases like diabetes and nephrosis. However, higher PTT-VIII values are seen in vasculitis, sickle cell disease, the hemolytic-uremic syndrome, thrombosis, and DIC. Lower values for VIII activity were seen by VIII-TGT in a group of vWd variant patients. Obligate carriers of hemophilia were best detected by the VIII-PTT. Lower than expected values for factor VIII were demonstrated in Intensively transfused hemophiliacs by the VIII-PTT. These studies indicate that the level of factor VIII procoagulant activity is significantly different in many clinical situations depending upon the method of measurement.

Measurement of factor VIII activity of B-domain deleted recombinant factor VIII

2001 ◽  
Vol 38 (2, Suppl 4) ◽  
pp. 13-23 ◽  
Author(s):  
M. Mikaelsson ◽  
U. Oswaldsson ◽  
M. A. Jankowski
Keyword(s):  
Factor Viii ◽  
Recombinant Factor Viii ◽  
Factor Viii Activity

Thrombelastography during and after Elective Abdominal Surgery

1978 ◽  
Vol 39 (02) ◽  
pp. 488-495 ◽  
Author(s):  
J M Butler
Keyword(s):  
Abdominal Surgery ◽  
Factor Viii ◽  
Whole Blood ◽  
Dominant Factor ◽  
Fibrinogen Concentration ◽  
Factor Viii Activity ◽  
Elective Abdominal Surgery

SummaryThrombelastography has been performed on recalcified whole blood from 50 patients before, during and after elective abdominal surgery. The characteristic changes of the thrombelastographic indices r, k and mA are described.During operation r and k shortened, but no change in mA was observed. This response was in part associated with an increase in factor VIII activity. Following operation, while r time was somewhat shortened, much more marked changes in k and mA were evident. Increasing fibrinogen concentration was the dominant factor in determining the post-operative changes in the thrombelastograph.

Impaired Fibrinolysis in Sickle Cell Disease

1970 ◽  
Vol 24 (01/02) ◽  
pp. 010-016 ◽  
Author(s):  
D Green ◽  
H. C Kwaan ◽  
G Ruiz
Keyword(s):  
Sickle Cell Disease ◽  
Factor Viii ◽  
Plasminogen Activator ◽  
Sickle Cell ◽  
Fibrinolytic Activity ◽  
Endothelial Damage ◽  
Cell Disease ◽  
Clotting Factors ◽  
Platelet Counts

SummaryCoagulation studies were performed in 52 patients with sickle cell disease during asymptomatic periods and during episodes of crisis and infection. Platelet counts averaged 473,000, 469,000, and 461,000 per mm3 in these 3 groups, and factor VIII concentrations were elevated in all. Fibrinogen was increased to the same extent in both sickle cell and non-sickle cell patients with infection. Fibrinolytic activity, as measured by euglobulin lysis times and zones of lysis on fibrin plates, was markedly reduced during periods of infection in sickle cell patients but not in non-sickle patients. Impairment of fibrinolysis in most patients was not on the basis of overutilization or consumption, since no decrease in the levels of clotting factors or plasminogen was observed. It was suggested that generalized intravascular sickling in these patients may have caused widespread endothelial damage, resulting in decreased production of plasminogen activator.In addition, several sickle cell patients with infection were found to possess elevated levels of an inhibitor directed against urokinase.

In Vitro Thrombogenicity Tests of Factor IX Concentrates

1979 ◽  
Vol 42 (05) ◽  
pp. 1355-1367 ◽  
Author(s):  
C V Prowse ◽  
A Chirnside ◽  
R A Elton
Keyword(s):  
Factor Viii ◽  
Partial Thromboplastin Time ◽  
Generation Time ◽  
Activated Partial Thromboplastin Time ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Factor Viii Inhibitor ◽  
Factor Ixa ◽  
Viii Inhibitor

SummaryVarious factor IX concentrates have been examined in a number of in vitro tests of thrombogenicity. The results suggest that some tests are superfluous as in concentrates with activity in any of these tests activation is revealed by a combination of the non-activated partial thromboplastin time, the thrombin (or Xa) generation time and factor VIII inhibitor bypassing activity tests. Assay of individual coagulant enzymes revealed that most concentrates contained more factor IXa than Xa. However only a small number of concentrates, chiefly those that had been purposefully activated, contained appreciable amounts of either enzyme.

Heparin, Protamine and Polybrene

1965 ◽  
Vol 13 (02) ◽  
pp. 550-560 ◽  
Author(s):  
Anthony Britten
Keyword(s):  
Factor Viii ◽  
Incubation Mixture ◽  
Factor V ◽  
Factor Viii Activity ◽  
Rapid Loss

SummaryThe effects of incubating heparin, protamine or Polybrene with plasma were studied. All three drugs cause rapid loss of factor V from decalcified plasma, while Polybrene also accelerates the loss of factor VIII activity. These changes are related to temperature, the period of incubation and the dose of the drug used, and can be partially prevented by inclusion of neutralizing doses of the appropriate antagonist in the incubation mixture.The implications of these findings are discussed.

Periodontal Pathogens and Neuropsychiatric Health

2020 ◽  
Vol 20 (15) ◽  
pp. 1353-1397 ◽  
Author(s):  
Abhishek Wadhawan ◽  
Mark A. Reynolds ◽  
Hina Makkar ◽  
Alison J. Scott ◽  
Eileen Potocki ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Metabolic Diseases ◽  
Low Grade ◽  
Periodontal Pathogens ◽  
Synergistic Interactions ◽  
Brain Vasculature ◽  
Micro Rnas ◽  
Clinical Conditions ◽  
Low Grade Inflammation ◽  
Neuropsychiatric Illness

Increasing evidence incriminates low-grade inflammation in cardiovascular, metabolic diseases, and neuropsychiatric clinical conditions, all important causes of morbidity and mortality. One of the upstream and modifiable precipitants and perpetrators of inflammation is chronic periodontitis, a polymicrobial infection with Porphyromonas gingivalis (P. gingivalis) playing a central role in the disease pathogenesis. We review the association between P. gingivalis and cardiovascular, metabolic, and neuropsychiatric illness, and the molecular mechanisms potentially implicated in immune upregulation as well as downregulation induced by the pathogen. In addition to inflammation, translocation of the pathogens to the coronary and peripheral arteries, including brain vasculature, and gut and liver vasculature has important pathophysiological consequences. Distant effects via translocation rely on virulence factors of P. gingivalis such as gingipains, on its synergistic interactions with other pathogens, and on its capability to manipulate the immune system via several mechanisms, including its capacity to induce production of immune-downregulating micro-RNAs. Possible targets for intervention and drug development to manage distal consequences of infection with P. gingivalis are also reviewed.

Upcoming Drifts In Bio-Similars

2020 ◽  
Vol 15 ◽  
Author(s):  
Geeta Aggarwal ◽  
Manju Nagpal ◽  
Ameya Sharma ◽  
Vivek Puri ◽  
Gitika Arora Dhingra
Keyword(s):  
Metabolic Diseases ◽  
Market Competition ◽  
Current Status ◽  
Medicinal Products ◽  
The Past ◽  
Biologic Activity ◽  
Emerging Trends ◽  
Regulatory Guidelines ◽  
Food Drug Administration ◽  
Insight Into

Background: Biopharmaceuticals such as Biologic medicinal products have been in clinical use over the past three decades and have benefited towards the therapy of degenerative and critical metabolic diseases. It is forecasted that market of biologics will be going to increase at a rate of 20% per year, and by 2025, more than ˃ 50% of new drug approvals may be biological products. The increasing utilization of the biologics necessitates for cost control, especially for innovators products that have enjoyed a lengthy period of exclusive use. As the first wave of biopharmaceuticals is expired or set to expire, it has led to various opportunities for the expansion of bio-similars i.e. copied versions of original biologics with same biologic activity. Development of biosimilars is expected to promote market competition, meet worldwide demand, sustain the healthcare systems and maintain the incentives for innovation. Methods: Appraisal of published articles from peer reviewed journals, PubMed literature, latest news and guidelines from European Medicine Agency, US Food Drug Administration (FDA) and India are used to identify data for review. Results: Main insight into the quality requirements concerning biologics, current status of regulation of biosimilars and upcoming challenges lying ahead for the upgrading of marketing authorization of bio-similars has been incorporated. Compiled literature on therapeutic status, regulatory guidelines and the emerging trends and opportunities of biosimilars has been thoroughly stated. Conclusion: Updates on biosimilars will support to investigate the possible impact of bio-similars on healthcare market.

Factor VIII Activity in Haemophilic Plasma unmasked by Synthetic Organic Anions

1972 ◽  
Vol 240 (100) ◽  
pp. 144-145 ◽  
Author(s):  
EDITH VON KAULLA ◽  
KURT N. VON KAULLA
Keyword(s):  
Factor Viii ◽  
Organic Anions ◽  
Factor Viii Activity

scholarly journals A note on some further determinations of the dielectric constants of organic bodies and electrolytes at very low temperatures

1898 ◽  
Vol 62 (379-387) ◽  
pp. 250-266 ◽  
Keyword(s):  
Dielectric Constant ◽  
Low Temperatures ◽  
Tuning Fork ◽  
Dielectric Constants ◽  
The Past ◽  
Method Of Measurement ◽  
The Given ◽  
Past Summer

In several previous communications we have described the investigations made by us on the dielectric constants of various frozen organic bodies and electrolytes at very low temperatures. In these researches we employed a method for the measurement of the dielectric constant which consisted in charging and discharging a condenser, having the given body as dielectric, through a galvanometer 120 times in a second by means of a tuning-fork interrupter. During the past summer we have repeated some of these determinations and used a different method of measurement and a rather higher frequency. In the experiments here described we have adopted Nernst’s method for the measurement of dielectric constants, using for this purpose the apparatus as arranged by Dr. Nernst which belongs to the Davy-Faraday Laboratory.

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