• Journal of Life Science
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• v.14 no.3
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• pp.441-444
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• 2004

This study was performed to establish a simple and rapid method for measuring thrombin activity based on weight of fibrin clot formed. The new method was based on the weight measurement of fibrin clot after enzymatic reaction of thrombin with fibrinogen. The fibrin formation depended upon the activities of thrombin used, temperature, incubation time, and centrifugation time. The fibrin formation was increased proportionally up to 1.0 unit/ml of thrombin activity, 4.0mg/ml of fibrinogen concentration, and 5 min of incubation time at 37$^{\circ}C$. The fibrin clot formed was stable by centrifugation at 3,000$\times$g for 5min. This simple assay based on weight of fibrin after centrifugation would be useful for identifying natural food anticoagulants by inhibiting thrombin.

• Restorative Dentistry and Endodontics
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• v.47 no.4
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• pp.42.1-42.11
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• 2022

Objective: This study investigated the effects of various concentrations of sodium hypochlorite (NaOCl) on human whole-blood clotting kinetics, the structure of the blood clots formed, and transforming growth factor (TGF)-β1 release. Materials and Methods: Human whole blood was collected from 5 healthy volunteers and divided into 4 groups: CG (control, 0.5 mL of blood), BN_0.5 (0.5 mL of blood with 0.5 mL of 0.5% NaOCl), BN₃ (0.5 mL of blood with 0.5 mL of 3% NaOCl), and BN_5.25 (0.5 mL of blood with 0.5 mL of 5.25% NaOCl). The effects of NaOCl on clotting kinetics, structure of fibrin and cells, and release of TGF-β1 were assessed using thromboelastography (TEG), scanning electron microscopy (SEM), and enzyme-linked immunosobent assay, respectively. Statistical analysis was conducted using the Kruskal Wallis and Mann-Whitney U tests, followed by the post hoc Dunn test. A p value < 0.05 indicated statistical significance. Results: The blood samples in BN_0.5 and BN₃ did not clot, whereas the TEG of BN_5.25 showed altered clot formation. Samples from the CG and BN₃ groups could only be processed with SEM, which showed that the latter lacked fibrin formation and branching of fibers, as well as clumping of red blood cells with surface roughening and distortion. TGF-β1 release was significantly highest in BN₃ when all groups were compared to CG (p < 0.05). Conclusions: Each concentration of NaOCl affected the release of TGF-β1 from blood clots and altered the clotting mechanism of blood by affecting clotting kinetics and cell structure.

• Journal of Periodontal and Implant Science
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• v.23 no.2
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• pp.283-299
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• 1993

The purpose of this study was to observe early connective tissue attachment on dentin surface treated with citric acid, tetracycline, and fibrin sealants and compare their conditioning effects on dentin surface. Experimental dentin blocks conditioned with citric acid, tetracycline or fibrin sealant, and only root planned control block were surgically implanted in the pouch under buccal mucoperiosteal flaps of left mandible, right maxilla, left maxilla, right mandible of 18 male rabbits. Rabbits were sacrificed after 1 and 6 hours, 1, 3, 7 and 14 days after implantation and then specimens including dentin block and surrounding soft tissue were obtained, and prepared for light and transmission electron microscopic examination. 1 and 6 hours after dentin block implantation, there was plasma proteins adsorption followed by fibrin clot formation and no differences among specimens. At the 1-day observation interval, delicate fibrin network was observed in the all groups, and there were proliferative fibroblasts, angiogenesis and macrophage in the all 3-day specimens. Cellular aggregates and abundant connective tissue adhered dentin surface and tetracycline or citric acid treated group showed much proliferative fibroblast and abundant collagen fibers at 1 week. But at 2 week, citric acid treated group showed much proliferative fibroblast and abundant collagen fibers. These observations suggested that new connective tissue attachment to dentin was initiated by the adsorption of plasma proteins to the dentin surface and followed by fibrin clot formation. Tetracycline and citric acid seemed to make dentin surface more biologically favorable for the connective tissue attachment.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.90-91
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• 2000

The physiological systems that control blood fluidity are both complex and elegant. Blood must remain fluid within the vasculature and yet clot quickly when exposed to nonendothelial surfaces at sites of vascular injury. There are two principle mechanisms to control a delicate balance in higher organisms (Davie & Ratnoff, 1964). Present evidence suggests that the intrinsic pathway play an important role in the growth and maintenance of fibrin formation in the coagulation cascade while a second overlapping mechanism, called the extrinsic pathway, is critical in the initiation of fibrin formation. Coagulation factors is in two mechanisms, and in order to clot blood, they are activated by a cooperation with $Ca^{2+}$, phospholipid and vitamin K etc. For example, the human placental anticoagulant protein (PAP of PAP- I), which is a $Ca^{2+}$ -dependent phospholipid binding protein (Funakoshi et al., 1987) inhibited the activity of factor Xa, so that it prolonged fibrin formation. We wondered whether any other protein was involved in regulation of the coagulant system as an anticoagulant protein from natural organisms. Natural agents would have not harmful side-effects in comparision with chemically synthesized materials such as warfarin, aspirin, phenindione, etc.. But anticoagulant agents from natural, especially marine organisms have hardly been researched except for polysaccharides from marine algae. (omitted)

• Journal of Biomedical Engineering Research
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• v.27 no.5
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• pp.267-273
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• 2006

Numerical analysis was performed on the enzyme transport and the flow fields in order to predict the effectiveness of urokinase injection regimens in clot dissolution. The species and momentum transport equations were numerically solved for the case of uniform perfusion of enzyme into a fibrin clot for an arterial thrombus and a deep vein thrombus models. In order to predict the thrombus lysis efficiency of continuous and forced intermittent injections, enzyme perfusion and clot lysis were simulated for the different injection velocities. Intermittent injection showed faster clot lysis compared to continuous perfusion, and lysis efficiency was increased as injection velocity increased.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.3
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• pp.216-222
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• 2013

Paradigm shift in management of infected immature permanent teeth has occurred. The new concept of the treatment includes minimal or no intracanal instrumentation, disinfection with triple antibiotic paste and sealing with mineral trioxide aggregate. This regenerative endodontic treatment promotes differentiation of periradicular stem cells that induce regeneration of vital tissue and continuation of root formation. Thorough disinfection and three-dimensional scaffold are important in this new concept of the treatment. Platelet-rich fibrin has been reported as 'new scaffold' instead of blood clot, which had been used in the past. Triple antibiotics can be used to disinfect the tooth but may lead to complications including discoloration. Three cases of infected immature permanent tooth caused by dens evaginatus fracture are presented. After removal of necrotic pulp and thorough intracanal irrigation, only platelet-rich fibrin was applied to the root canal in the first case. In the other cases, topical antibiotics was used for disinfection and platelet-rich fibrin for scaffold. In all the cases, the opening was sealed with mineral trioxide aggregate. All the cases showed proper healing of inrabony lesion and some lengthening of root. According to these cases, regenerating vital tissue of the infected immature permanent tooth can be achieved with disinfection and application of platelet-rich fibrin.

• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.3
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• pp.143-157
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• 2015

Successful integration of cementless femoral stems using porous surfaces relies on effective periimplant bone healing to secure the bone-implant interface. The initial stages of the healing process involve protein adsorption, fibrin clot formation and cell osteoconduction onto the implant surface. Modelling this process in vitro, the current work considered the effect of fibrin deposition on the responses of human mesenchymal stromal cells cultured on ferritic fibre networks intended for magneto-mechanical actuation of in-growing bone tissue. The underlying hypothesis for the study was that fibrin deposition would support early stromal cell attachment and physiological functions within the optimal regions for strain transmission to the cells in the fibre networks. Highly porous fibre networks composed of 444 ferritic stainless steel were selected due to their ability to support human osteoblasts and mesenchymal stromal cells without inducing untoward inflammatory responses in vitro. Cell attachment, proliferation, metabolic activity, differentiation and penetration into the ferritic fibre networks were examined for one week. For all fibrin-containing samples, cells were observed on and between the metal fibres, supported by the deposited fibrin, while cells on fibrin-free fibre networks (control surface) attached only onto fibre surfaces and junctions. Initial cell attachment, measured by analysis of deoxyribonucleic acid, increased significantly with increasing fibrinogen concentration within the physiological range. Despite higher cell numbers on fibrin-containing samples, similar metabolic activities to control surfaces were observed, which significantly increased for all samples over the duration of the study. It is concluded that fibrin deposition can support the early attachment of viable mesenchymal stromal cells within the inter-fibre spaces of fibre networks intended for magneto-mechanical strain transduction to in-growing cells.

• Restorative Dentistry and Endodontics
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• v.47 no.4
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• pp.41.1-41.20
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• 2022

Objectives: This study compared the clinical and radiological outcomes of regenerative endodontic procedures (REPs) using blood clots (BCs), platelet-rich plasma (PRP), and platelet-rich fibrin (PRF) through intraoral periapical radiography (IOPAR) and cone-beam computed tomography (CBCT). Materials and Methods: Forty-five single-rooted necrotic teeth with periapical pathology were randomly allocated to receive BC, PRP, or PRF as an individual scaffold. Outcomes were evaluated in 35 teeth in 23 patients with a follow-up period of 12-24 months through qualitative IOPAR scoring and quantitative CBCT measurements. Healing of periapical lesions and in immature teeth, changes in the apical foramen diameter (AFD), root wall thickness (RWT), and root length (RL) were assessed. A p value less than 0.05 was considered to indicate statistical significance. Results: All teeth were asymptomatic except 1 in the PRP group. Periapical lesion healing was seen in all except 2 teeth in the BC group and 3 in the PRP group. Both IOPAR and CBCT revealed no significant differences in bone healing or changes in AFD, RWT, and RL among the 3 groups. A positive pulp sensibility response to the cold test was seen in 2 teeth in the BC group, but none to the electric pulp test. Intracanal calcification (ICC) was evident in more teeth in the BC group than in the PRP and PRF groups, and was also significantly higher in immature teeth. Conclusions: Our results revealed that BC, PRP, and PRF have similar potential as scaffolds in REPs, and ICC may be a concern for long-term outcomes.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.1
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• pp.81-88
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• 1999

A fibrin adhesive have been widely used in oral and maxillofacial surgery for microvascular anastomosis, autogenous chip bone grafts, many kinds of soft tissue surgery (vestibuloplasty, bleeding control after extraction, primary healing by covering of suture of a gum after the extirpation of large cysts). There are two principal components in adhesive systems biologically: lyophilized human fibrinogen and bovine thrombin. The fibrinogen component contains coagulation factor XIII and enhance the initial wound healing, which polymerizes soluble fibrin monomers into an insoluble clot. The thrombin is dissolved in a solution of calcium chloride to provide the second component. We applied fibrin adhesive, Beriplast (Behring, Behringwerke AG, D-3350, Marburg, FRD), to 4 patients for fixation of free skin grafting donors who had facial scar around eye, nose, mouth corner which received from accidents, or burn. We have experienced initial accelerated graft fixation between donor and recipient sites with no additional fixation. And It's made easy bleeding control and easy manipulation during operation. But two cases showed partial hypertrophic scar engrowth in above 3 months follow up, but no significant. Histopathological reviews in general were showed similar scar findings such as abundant collagen bundles in H&E, M/T stain, but slight positive signs in elastic and collagen antibody immunopathologic findings in hypertrophic scar cases.

• Journal of Periodontal and Implant Science
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• v.52 no.1
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• pp.54-64
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• 2022

Purpose: This in vitro study was conducted to evaluate the effects of different debridement techniques and conditioning procedures on root surface morphology and blood clot stabilization. Methods: Two debridement techniques (curette [CU] vs. high-speed ultrasound [US]) and 2 conditioning procedures (ethylenediaminetetraacetic acid [EDTA] and phosphoric acid [PA]) were used for the study. Seven experimental groups were tested on root surfaces: 1) no treatment (C); 2) CU; 3) US; 4) CU+EDTA; 5) US+EDTA; 6) CU+PA; and 7) US+PA. Three specimens per group were observed under scanning electron microscopy (SEM) for surface characterization. Additional root slices received a blood drop, and clot formation was graded according to the blood element adhesion index by a single operator. Data were statistically analyzed, using a threshold of P<0.05 for statistical significance. Results: The C group displayed the most irregular surface among the tested groups with the complete absence of blood traces. The highest frequency of blood component adhesion was shown in the CU+EDTA group (P<0.05), while no differences were detected between the CU, US+EDTA, and CU+PA groups (P<0.05), which performed better than the US and US+PA groups (P<0.05). Conclusions: In this SEM analysis, EDTA and conventional manual scaling were the most efficient procedures for enhancing smear layer removal, collagen fiber exposure, and clot stabilization on the root surface. This technique is imperative in periodontal healing and regenerative procedures.