Factor VIII, a component of the intrinsic pathway of blood coagulation, has yet to be purified to homogeneity. It appears that, in vivo, the factor VIII coagulant protein is closely associated with one or more other proteins (factor VHI-related antigen and platelet aggregating factor). The material normally isolated from bovine plasma as 'factor VIII' possesses all three activities and is therefore either a mixture or a complex of the various proteins. In the present study, bovine factor VIII:C was purified approximately fivethousand- fold by a combination of ion-exchange chromatography and fractional precipitation. The factor VIII coagulant activity can be separated from the other activities of the 'factor VIII complex' but the procedures involved are not suitable for preparative use as the factor VIII:C which is obtained is unstable. During coagulation, factor VIII:C is required during the activation of factor X. Studies with purified bovine clotting factors indicate that factor IX_a is the enzyme responsible for the cleavage of factor X, in a calcium-dependent reaction which is stimulated by phospholipid. Factor VIII:C further accelerates the rate at which factor X_a is generated. Preliminary investigations of the kinetic parameters of the reaction indicate that the stimulation by factor VIII:C occurs through a marked increase in the V_max of the reaction; factor VIII:C does not affect the K_m for factor X. The coagulant activity of factor VIII is enhanced by exposure to thrombin, but the 'activated' factor VIII:C which is produced is not itself capable of activating factor X in the absence of factor IX_a. Thus, the 'activation' of factor VIII:C, in contrast to the activation of, for example, factors IX and X, does not appear to result in the formation of an enzyme. That is, factor VIII:C is a non-enzymic, high molecular weight cofactor for factor IX_a.

Thesis (Ph.D. in Clinical Science) -- University of Colorado Denver, 2008. / Typescript. Includes bibliographical references (leaves 136-146). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;

Thesis (doctoral)--Lund University, 1994. / Added t.p. with thesis statement inserted.

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206 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (M.D.)--Dept. of Medicine, University of Adelaide, 1974

Thesis (Ph.D.)--Cleveland State University, 2009. / Abstract. Title from PDF t.p. (viewed on Jan. 13, 2010). Includes bibliographical references (p. 124-131). Available online via the OhioLINK ETD Center and available in print.

Background: Blood clot formation is one of the first events in bone regeneration and osseointegration. The blood clot adheres to dental implants with hydrophilic surfaces more favorably than to those with hydrophobic surfaces. This appears to result in better bone healing and bone fill of defects around dental implants. Objective: To assess the impact of blood clot stabilization at modSLA titanium implants on bone formation in chronic-type defects in a dog model. Material & methods: Ten modSLA implants were installed in 5 dogs after creation of saddle-type buccal-lingual bony defects. In 5 implants (test sites), the blood clot was removed by sterile saline irrigation, while the clot was left undisturbed on the other 5 implants (control sites). After 8 weeks of healing, the animals were sacrificed and sections were prepared for histomorphometric analysis. The following measurements were performed: The residual defect length (DL), the buccal and lingual most coronal level of bone in contact with the implant (CBI-b and CPI-l), the new bone height (NBH), the percentage of bone to implant contact (BIC), the area of new bone fill (BF), the difference in buccal and lingual dimensions of CBI (D-CBI), and percentage of linear bone fill (PLF). Results: the mean values of DL were similar in both groups (3.4 mm). All parameters assessed were consistently more favorable in control sites: CBI-b: 1.3 vs. 1.5, CBI-l: 1.3 vs. 0.8, D-CBI: -0.2 vs -0.5, NBH: 1.9 mm vs. 2.1 mm, PLF: 57.1% vs. 64.5% and BF: 4.4 mm? vs. 6.0 mm?. However, these differences were not statistically significant. Conclusion: In the light of consistently more favorable parameters assessed for the healing of saddle-shaped bony defects around implants, it is assumed that a stabilized blood clot contributed to early bone regeneration and osseointegration. Undisturbed blood clot formation may, indeed, be a prerequisite for optimal treatment outcomes. However, owing to the small sample size in the present study, these tendencies ought to be explored in further studies. / published_or_final_version / Dental Surgery / Master / Master of Dental Surgery

Thesis (PhD)--University of South Australia, 2000