Clinicopathological features of fibrin-associated diffuse large B-cell lymphoma: a report of six cases / 中华病理学杂志

Objective: To investigate the clinical, pathological and immunophenotypic features, molecular biology and prognosis of fibrin-associated large B-cell lymphoma (LBCL-FA) in various sites. Methods: Six cases of LBCL-FA diagnosed from April 2016 to November 2021 at the Beijing Friendship Hospital, Capital Medical University, Beijing, China and the First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China were collected. The cases were divided into atrial myxoma and cyst-related groups. Clinical characteristics, pathological morphology, immunophenotype, Epstein Barr virus infection status, B-cell gene rearrangement and fluorescence in situ hybridization of MYC, bcl-2, bcl-6 were summarized. Results: The patients' mean age was 60 years. All of them were male. Three cases occurred in atrial myxoma background, while the others were in cyst-related background, including adrenal gland, abdominal cavity and subdura. All cases showed tumor cells located in pink fibrin clot. However, three cyst-related cases showed the cyst wall with obviously fibrosis and inflammatory cells. All cases tested were non germinal center B cell origin, positive for PD-L1, EBER and EBNA2, and were negative for MYC, bcl-2 and bcl-6 rearrangements, except one case with MYC, bcl-2 and bcl-6 amplification. All of the 5 cases showed monoclonal rearrangement of the Ig gene using PCR based analysis. The patients had detailed follow-ups of 9-120 months, were treated surgically without radiotherapy or chemotherapy, and had long-term disease-free survivals. Conclusions: LBCL-FA is a group of rare diseases occurring in various sites, with predilection in the context of atrial myxoma and cyst-related lesions. Cyst-related lesions with obvious chronic inflammatory background show more scarcity of lymphoid cells and obvious degeneration, which are easy to be missed or misdiagnosed. LBCL-FA overall has a good prognosis with the potential for cure by surgery alone and postoperative chemotherapy may not be necessary.

Treatment of Chondral Knee Lesions with Autologous Chondrocytes Embedded in a Fibrin Scaffold. Clinical and Functional Assessment / Tratamento de lesões condrais no joelho com condrócitos autólogos embebidos em arcabouço de fibrina. Avaliação clínica e funcional

Abstract Objective The aim of our study is to analyze the clinical and functional results obtained using autologous chondrocytes embedded in a fibrin scaffold in knee joint injuries. Methods We included 56 patients, 36 men and 20 women, with a mean age 36 years. Six of the patients were professional athletes, with single knee injuries that were either chondral or osteochondral (43 chondral, 9 osteochondral, 2 cases of osteochondritis dissecans and 2 osteochondral fractures), 2 to 10 cm2 in size and ≤ 10 mm deep, with no signs of osteoarthritis. The location of the injury was in the patella (8), the medial femoral condyle (40) and lateral femoral condyle (7) and one in the trochlea. The mean follow-up was 3 (range: 1-6) years. The clinical course was assessed using the Cincinnati and Knee Injury and Osteoarthritis Outcome (KOOS) scores, 6 and 12 months after surgery. The paired Student t-test was used to compare pre-and postoperative results. Results Six months after the implant, patients resumed their everyday activities. On the assessment scores, their condition was improving in comparison with their presurgical state (p < 0.05). They were also able to carry out their sporting activities more easily than prior to surgery (p < 0.05). Conclusion The seeding of chondrocytes in fibrin may provide a favorable microenvironment for the synthesis of extracellular matrix and improved the clinical condition and activity of the patients 1 year after surgery.

Resumo Objetivo O objetivo do nosso estudo é analisar os resultados clínicos e funcionais do tratamento de lesões nas articulações do joelho com condrócitos autólogos embebidos em arcabouço de fibrina. Métodos O estudo foi realizado com 56 pacientes (36 homens e 20 mulheres) com idade média de 36 anos; 6 indivíduos eram atletas profissionais. Os pacientes apresentavam lesões únicas, condrais ou osteocondrais (43 condrais, nove osteocondrais, 2 casos de osteocondrite dissecante e duas fraturas osteocondrais) no joelho, com 2 a 10 cm2 de tamanho e ≤ 10 mm de profundidade, sem sinais de osteoartrite. As lesões estavam localizadas na patela (8), no côndilo femoral medial (40), no côndilo femoral lateral (7) e na tróclea (1). O período médio de acompanhamento foi de 3 anos (faixa de 1-6 anos). A evolução clínica foi avaliada pelos escores de Cincinnati e Knee Injury and Osteoarthritis Outcome (KOOS), 6 e 12 meses após a cirurgia. O teste t de Student pareado foi utilizado para comparação dos achados pré e pós-operatórios. Resultados Os pacientes retomaram suas atividades diárias 6 meses após o implante. Os escores avaliados demonstraram a melhora em comparação ao estado pré-cirúrgico (p < 0,05). Além disso, os pacientes conseguiram realizar suas atividades esportivas com mais facilidade do que antes da cirurgia (p < 0,05). Conclusão A cultura de condrócitos em fibrina pode proporcionar um microambiente favorável para a síntese de matriz extracelular e melhorar a condição clínica e a atividade dos pacientes 1 ano após a cirurgia

Recurrent pterygium resection associated to fibrin membrane graft: report of two cases / Resseção do pterígio recorrente associada ao enxerto de membrana fibrina: relato de dois casos

ABSTRACT We propose a novel surgical technique in cases of aggressive recurrent pterygium non-subsidiary of treatment with conjunctival autografts or antimetabolites. Two presented cases were treated with surgical excision and a sutured plasma rich in growth factors membrane (mPRGF) followed by rich in growth factors (PRGF) eye drops treatment. After surgery, dexamethasone, tobramycin and PRGF eye drops were prescribed for 6 weeks. After a 12-month and 3-year post-surgical follow-up respectively, treated eyes with mPRGF did not present relapse, and visual acuity improved in both cases. No ocular complications, pain, eye discomfort nor other symptoms were observed. The combined use of PRGF eye drops and mPRGF seems an effective and safe therapy for recurrent pterygium.

RESUMO Nós propomos uma nova técnica cirúrgica em casos de pterígio agressivo recorrente não subsidiário de tratamento com autoenxertos conjuntivais ou antimetabólitos. Dois casos foram tratados com excisão cirúrgica e um plasma suturado rico em membrana de fatores de crescimento (mPRGF), seguido de tratamento com colírios ricos em fatores de crescimento (PRGF). Após a cirurgia, foram prescritos colírios de dexametasona, tobramicina e PRGF por 6 semanas. Após 12 meses e 3 anos de acompanhamento pós-cirúrgico respectivamente, os olhos tratados com mPRGF não apresentaram recidiva e a acuidade visual melhorou nos dois casos. Não foram observadas complicações oculares, dor, desconforto ocular ou outros sintomas. O uso combinado de colírios de PRGF e mPRGF parece uma terapia eficaz e segura para o pterígio recorrente.

Factores de crecimiento en el plasma: herramienta terapéutica en dermatología / Growth factors in plasma: therapeutic tool in dermatology

Las plaquetas contienen una gran cantidad de factores de crecimiento que participan en los procesos de cicatrización tisular. Entre ellos, el factor de crecimiento derivado de las plaquetas (PDGF), el factor de crecimiento transformante (TGF), el factor plaquetario 4 (PF4), la interleucina (IL)-1, el factor angiogénico derivado de las plaquetas (PDAF), el factor de crecimiento endotelial (VEGF), el factor de crecimiento epidérmico (EGF), el factor de crecimiento endotelial derivado de las plaquetas (PDEGF), el factor de crecimiento de células epiteliales (ECGF) y el factor de crecimiento similar a la insulina (IGF). El plasma rico en plaquetas (PRP) es un derivado sanguíneo concentrado de la sangre total con una alta concentración de plaquetas. Otro componente esencial del PRP son las proteínas que actúan a nivel de la adhesión celular (fibrina, fibronectina y vitronectina), que proporcionan el soporte estructural necesario para la migración celular y para la proliferación y crecimiento tridimensional de los tejidos sobre los que actúa. La fibrina es la forma activada del fibrinógeno, sustrato final de todas las reacciones de coagulación, se transforma en fibrina insoluble por acción de la trombina. El gel de fibrina polimerizado constituye la primera matriz cicatricial de las heridas. Tanto el plasma rico en plaquetas como las mallas de fibrina varían en la composición y concentración de factores de crecimiento, proteínas y citocinas. En este trabajo se revisan las características de estos productos biológicos, su aplicación en dermatología así como los principales requisitos para su preparación(AU)

Platelets contain a large amount of growth factors involved in the processes of tissue healing. Among them, plateletderived growth factor (PDGF), transforming growth factor (TGF), platelet factor 4 (PF4), interleukin (IL) -1, angiogenic factor derived from platelets (PDAF) , the endothelial growth factor (VEGF), the epidermal growth factor (EGF), the plateletderived endothelial growth factor (PDEGF), the epithelial cell growth factor (ECGF) and the Insulin like growth factor (IGF). Platelet-rich plasma (PRP) is a concentrated whole blood derivate with a high concentration of platelets. Another essential component of PRP are proteins acting on cell adhesion (fibrin, fibronectin and vitronectin), which provide the structural support necessary for cell migration and proliferation as well as three-dimensional growth of the tissues on which they act. Fibrin is the activated form of fibrinogen, the final substrate of all coagulation reactions. It is transformed into insoluble fibrin by the action of thrombin. The polymerized fibrin gel constitutes the first cicatricial matrix of wounds. Both plateletrich plasma and fibrin meshes vary in the composition and concentration of growth factors, proteins and cytokines. In this work we review the characteristics of these biological products, their application in dermatology as well as main requirements for their preparation(AU)

Avaliação da qualidade dos agregados leucoplaquetários / Evaluation of the quality of the leuco platelet aggregates

Objetivo ­ Avaliar a qualidade do plasma rico em plaquetas (PRP) e da fibrina rica em plaquetas (PRF) obtidos através de alguns tipos de protocolos de obtenção por meio da contagem de plaquetas e leucócitos nos materiais. Métodos ­ Foram coletadas amostras de sangue de voluntários mediante aprovação do Comitê de Ética em Pesquisa (CEP). As amostras foram centrifugadas em diferentes rotações e tempos (1300 RPM por 5 minutos, 550 RPM por 5 minutos e 550 RPM por 3 minutos). As concentrações de plaquetas e leucócitos foram avaliadas no Coulter LH 750 analyzer. Os resultados foram submetidos a análise estatística (Graph Pad Prism). Resultados ­ As dosagens de plaquetas foram significativamente maiores (p<0.0001) no protocolo de PRF centrifugado a 1300 rpm em comparação com os outros materiais, e as dosagens de leucócitos foram maiores no PRF centrifugado a 550 rpm (p<0.05). Conclusão ­ Os resultados desse trabalho sugerem que a velocidade de centrifugação, o uso de anticoagulante e o tempo de centrifugação são alguns interferentes que afetam a qualidade do material obtido impactando na diminuição do número de células presentes no material. Os resultados também apontam que o PRF apresenta maiores concentrações celulares, principalmente próximo à camada de leucócitos

Objective ­ To evaluate the quality of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) obtained through some types of protocols for obtaining platelet and leukocyte counts in the materials. Methods ­ Blood samples were collected from volunteers with the approval of the Research Ethics Committee (CEP). The samples were centrifuged at different speeds and times (1300 RPM for 5 minutes, 550 RPM for 5 minutes and 550 RPM for 3 minutes). Platelet and leukocyte concentrations were evaluated on the Coulter LH 750 analyzer. The results were subjected to statistical analysis (Graph Pad Prism). Results ­ Platelet dosages were significantly higher (p <0.0001) in the PRF protocol centrifuged at 1300 rpm compared to other materials, and leukocyte dosages were higher in PRF centrifuged at 550 rpm (p <0.05). Conclusion ­ The results of this work suggest that the centrifugation speed, the use of anticoagulant and the centrifugation time are some interferents that affect the quality of the material obtained impacting on the decrease of the number of cells present in the material. The results also point out that PRF presents higher cellular concentrations, mainly near the leukocyte layer

Chronic venous ulcers: a review on treatment with fibrin sealant and prognostic advances using proteomic strategies

Venous ulcers are the main causes of chronic lower-limb ulcers. The healing difficulties encourage the research and development of new products in order to achieve better therapeutic results. Fibrin sealant is one of these alternatives. Besides being a validated scaffold and drug delivery system, it possesses excellent healing properties. This review covered the last 25 years of the literature and showed that the fibrin sealant is used in various clinical situations to promote the healing of different types of ulcers, especially chronic ones. These are mostly venous in origin and usually does not respond to conventional treatment. Commercially, only the homologous fibrin sealants obtained from human blood are available, which are highly efficient but very expensive. The heterologous fibrin sealant is a non-commercial experimental low-cost product and easily produced due to the abundance of raw material. The phase I/II clinical trial is already completed and showed that the product is safe and promisingly efficacious for the treatment of chronic venous ulcers. In addition, clinical proteomic strategies to assess disease prognosis have been increasingly used. By analyzing liquid samples from the wounds through proteomic strategies, it is possible to predict before treatment which ulcers will evolve favorably and which ones will be difficult to heal. This prognosis is only possible by evaluating the expression of isolated proteins in exudates and analysis using label-free strategies for shotgun. Multicentric clinical trials will be required to evaluate the efficacy of fibrin sealant to treat chronic ulcers, as well as to validate the proteomic strategies to assess prognosis.(AU)

Neuroprotection and immunomodulation by dimethyl fumarate and a heterologous fibrin biopolymer after ventral root avulsion and reimplantation

Ventral root avulsion (VRA) is an experimental approach in which there is an abrupt separation of the motor roots from the surface of the spinal cord. As a result, most of the axotomized motoneurons degenerate by the second week after injury, and the significant loss of synapses and increased glial reaction triggers a chronic inflammatory state. Pharmacological treatment associated with root reimplantation is thought to overcome the degenerative effects of VRA. Therefore, treatment with dimethyl fumarate (DMF), a drug with neuroprotective and immunomodulatory effects, in combination with a heterologous fibrin sealant/biopolymer (FS), a biological glue, may improve the regenerative response. Methods: Adult female Lewis rats were subjected to VRA of L4-L6 roots followed by reimplantation and daily treatment with DMF for four weeks. Survival times were evaluated 1, 4 or 12 weeks after surgery. Neuronal survival assessed by Nissl staining, glial reactivity (anti-GFAP for astrocytes and anti-Iba-1 for microglia) and synapse preservation (anti-VGLUT1 for glutamatergic inputs and anti-GAD65 for GABAergic inputs) evaluated by immunofluorescence, gene expression (pro- and anti-inflammatory molecules) and motor function recovery were measured. Results: Treatment with DMF at a dose of 15 mg/kg was found to be neuroprotective and immunomodulatory because it preserved motoneurons and synapses and decreased astrogliosis and microglial reactions, as well as downregulated the expression of pro-inflammatory gene transcripts. Conclusion: The pharmacological benefit was further enhanced when associated with root reimplantation with FS, in which animals recovered at least 50% of motor function, showing the efficacy of employing multiple regenerative approaches following spinal cord root injury.(AU)

Uso do plasma rico em plaquetas (PRP) e plasma rico em fibrina (PRF) em defeitos peri-implantares: análises biomecânica e histomorfométrica / The use of platelet rich plasma (PRP) and fibrin rich plasma (PRF) in peri-implant defects: biomechanical and histomorphometric analyzes

O presente trabalho teve o objetivo avaliar o uso do plasma rico em plaquetas (PRP) e plasma rico em fibrina (PRF) em defeitos peri-implantares por meio das análises biomecânica e histomorfométrica. Para tanto, 36 ratos machos adultos foram divididos em 3 grupos: controle (CO), plasma rico em plaquetas (PRP) e plasma rico em fibrina (PRF). Previamente à realização dos procedimentos cirúrgicos, foram coletados 3 ml de sangue de cada animal via punção cardíaca, seguindo-se pelos respectivos protocolos de centrifugação para obtenção de PRP e PRF. Um defeito ósseo foi preparado na tíbia esquerda e um implante foi instalado manualmente. Conforme o grupo experimental, o defeito peri-implantar não sofreu intervenção ou foi preenchido com PRP ou PRF. A eutanásia foi realizada em 20 e 40 dias. Os resultados mostraram que houve diferença estatística significativa presente intergrupos e interperíodos (p< 0,05) na análise biomecânica. Os resultados histológicos apresentaram maior atividade celular nos grupos experimentais em relação ao grupo controle. Os dados sobre a área óssea neoformada (AON) demonstraram uma maior formação óssea nos grupos PRP e PRF em relação ao grupo controle. Entretanto, entre todos os grupos não houve diferença estatística significativa, assim como na análise entre os grupos e os períodos. Contudo, entre os períodos houve diferença estatística significativa (p< 0,001). A aplicação de PRP nos defeitos peri-implantares em tíbias de ratos mostrou-se mais eficaz na resposta de estabilidade do implante e na neoformação óssea sendo superior ao plasma rico em fibrina (PRF) e ao grupo controle (coágulo). Relevância Clínica: os defeitos peri-implantares são uma realidade clínica e o uso de concentrados plaquetários é uma alternativa para um tratamento. A literatura apresenta resultados satisfatórios em relação às altas concentrações de fatores de crescimento que podem afetar o processo de regeneração tecidual e neoformação óssea(AU)

The aim of the present study was to evaluate the use of platelet-rich plasma (PRP) and platelet rich fibrin (PRF) in peri-implant defects submitted to biomechanical and histomorphometric analysis. Thirty-six adult male rats were divided into 3 groups: control (CO), platelet rich plasma (PRP) and fibrin rich plasma (PRF). Prior to the surgical procedures, 3 ml of blood were collected from each animal via cardiac puncture, followed by the respective centrifugation protocols to obtain PRP and PRF. A bone defect was prepared in the left tibia and an implant was manually installed. The defect was filled with PRP, PRF or own clot. Euthanasia was performed at 20 and 40 days. The results showed that there was statistically significant difference between groups and periods (p < 0.05) in the biomechanical analysis. The histological results showed higher cellular activity in the experimental groups compared to the control group. Data on the newly bone area showed a higher bone formation in the PRP and PRF groups compared to the control group. However, there was no statistically significant difference in all groups, as well as in the analysis between groups and periods. Only between the periods there was a statistically significant difference (p < 0.001). The application of PRP to peri-implant defects in rat tibias was more effective in implant stability response and bone neoformation being superior to fibrin-rich plasma (PRF) and control group (clot)(AU)

Fibrin Clot Mistook as a Worm in the Intravenous Line

There have been several reports of foreign bodies being discovered in the intravenous set. In this case, the patient complained that he found a worm in his intravenous line. It was later confirmed as a long, white fibrin deposit by pathologic examination. This happened even though there was a non-return valve in the intravenous line. Also, since there were few red blood cells in the deposit, it did not look like a blood clot. In cases like this, we suggest that physicians keep this possibility in mind to reassure their patients.

Uso de plasma rico en fibrina comparado con colágeno en el tratamiento de recesión gingival utilizando la técnica estenopéica. Ensayo clínico aleatorizado / Use of fibrin-rich plasma compared to collagen in the treatment of gingival recession using the stenopic technique. Randomized clinical trial

La recesión gingival (RG) es un problema de salud bucodental frecuente que aumenta con la edad, predispone a hipersensibilidad dentaria, caries radicular, inflamación gingival y efectos antiestéticos. El objetivo de este ensayo clínico aleatorizado fue evaluar comparativamente el efecto clínico del recubrimiento radicular utilizando la técnica estenopéica Pinhole con colágeno y la técnica estenopéica Pinhole modificada al incorporarle plasma rico en fibrina (PRF). Veintiséis participantes sistémicamente sanos, con diagnóstico de RG grado I de Miller, fueron reclutados y seguidos por 6 meses después de la cirugía. Los parámetros clínicos registrados fueron nivel de inserción clínica (NIC), RG y banda de encía queratinizada. Los participantes fueron asignados aleatoriamente a un grupo en quienes se utilizó PRF con 14 participantes, tratando 36 piezas dentales, y otro grupo en quienes se utilizó membrana de colágeno con 12 participantes, tratando 35 piezas dentales. Los resultados muestran un logro de ganancia en el NIC en ambos grupos, (M = 45.24 %, DE = 17.37 %) en el grupo PRF y (M = 47.37 %, DE = 15.67 %) en el grupo colágeno, diferencia que no fue significativa (p = .59). En ambos grupos existió un aumento significativo en la banda de encía queratinizada (p < .01). El uso de PRF como material de relleno al realizar la técnica estenopéica genera resultados similares al ser comparado con la técnica convencional que utiliza colágeno. Al presentar un menor costo el PRF aumenta las posibilidades que más personas tengan acceso al tratamiento.

Gingival recession (GR) is a frequent oral health disease that increases with age and may increase risk of dental hypersensitivity, root decay, gingival inflammation and aesthetic problems. The aim of this randomized clinical trial was to compare clinical parameters of dental root coverage using Pinhole technique with collagen and modi¬fied Pinhole technique using platelet-rich fibrin (PRF). Twenty-six participants, systemically healthy, with Miller class I GR diagnosis, were recruited and measured at baseline and after 6 months follow-up. Clinical parameters measured included clinical attachment level (ICL), GR and keratinized gingival width (KGW). All participants were randomly assigned to a group using PRF, with 14 participants and 36 teeth treated, and other group using collagen, with 12 participants and 35 teeth treated. Both PRF group and collagen group gained ICL, (M = 45.24 %, SD = 17.37 %) in PRF group and (M = 47.37 %, SD = 15.67 %) in collagen group, with no statistically significant difference (p = .59). Both groups gained KGW (p < .01). Use of PRF as filled material by using Pinhole technique resulted in similar clinical improvements compare to collagen as filled material. Considering that PRF is cheaper than collagen, it increases chances that people can have access to treatment.

Efectividad del plasma rico en fibrina y membrana de colágeno en la regeneración ósea guiada / Effectiveness of fibrin-rich plasma and collagen membrane in guided bone regeneration

RESUMEN: Objetivo: de este estudio fue determinar la efectividad de dos biomateriales, el plasma rico en fibrina (PRF) y la membrana de colágeno en la regeneración ósea guiada. Materiales y método: Fueron utilizados 30 cobayos adultos machos entre 900 a 1100 g. divididos en tres grupos de 10 cobayos cada uno (Grupo A: Control, grupo B: Membrana de colágeno y grupo C: Plasma rico en fibrina). A cada grupo se le creó un defecto óseo mandibular unilateral de 2mm. Al grupo A no se colocó un biomaterial, en los grupos B y C sí se colocaron los biomateriales en los defectos óseos. A los 15 y 30 días de cicatrización se realizaron cortes histológicos para evaluar la cantidad de fibroblastos, osteocitos y osteoblastos. Resultados: A los 15 días el grupo C formó 40,6 ± 8,08 osteocitos/camp y el grupo B 27,6 ± 4,72 (p<0.05); a los 30 días el grupo C: 30,6 ± 11,55 y el grupo B: 23,6 ±3,85 (p>0.05). Conclusión: El PRF induce una mayor proliferación celular de forma significativa que los otros grupos en los primeros días de cicatrización; a los 30 días la proliferación es similar con el grupo de membrana de colágeno sin existir diferencias significativas.

ABSTRACT: Aim: of this study was to determine the effectiveness of two biomaterials, fibrin-rich plasma (PRF) and collagen membrane in guided bone regeneration. Materials and method: Thirty male guinea pigs were used, weighing between 900 and 1100 g., divided into three groups of 10 guinea pigs each (Group A: control, group B: collagen membrane and group C: fibrin-rich plasma). Each group had a 2-mm unilateral mandibular bone defect. Group A did not receive any biomaterial; in groups B and C the biomaterials were used in the bone defects. After 15 and 30 days of healing, histological sections were performed to evaluate the amount of fibroblasts, osteocytes and osteoblasts. Results: After 15 days, group C formed 40.6 ± 8.08 osteocytes / camp and group B 27.6 ± 4.72 (p <0.05); After 30 days, group C: 30.6 ± 11.55 and group B: 23.6 ± 3.85 (p> 0.05). Conclusion: During the first 15 days of healing, PRF induces a greater cellular proliferation than the other groups in a significant way; after 30 days, the proliferation is similar to the collagen membrane group without significant differences.

Produção e purificação integrada de protease fibrinolítica de Mucor subtilissimus UCP 1262 / Integrated production and purification of fibrinolytic protease from Mucor subtilissimus UCP 1262

As enzimas fibrinolíticas podem ser obtidas de micro-organismos por meio de processos fermentativos. O presente trabalho teve como objetivo avaliar a produção e extração integrada da protease fibrinolítica de Mucor subtilissimus UCP 1262 usando sistema de duas fases aquosas (SDFA). O processo integrado foi realizado para avaliar a produção, partição e recuperação da protease fibrinolítica, segundo planejamento experimental 23, utilizando como variáveis independentes a massa molar do polietileno glicol (PEG), a concentração do PEG e a concentração do sulfato de sódio. A maior atividade fibrinolítica (15,40U/mL) foi obtida na fase rica em sulfato de sódio no ensaio composto por 10% de sal e 18% de PEG 8000 (g/mol). Recuperações superiores a 80% foram obtidas. A protease fibrinolítica apresentou pH ótimo 7,0, estabilidade entre os pH 6,0 e 8,5, temperatura ótima 50°C, sendo estável de 10°C a 50°C. A enzima foi classificada como uma serino protease, com massa molecular de 52kDa. Como resultado, o processo é notavelmente eficaz para pré-purificar a protease fibrinolítica com baixo custo e rapidez significativa. Quando comparada a outras técnicas de produção e purificação isoladas, a fermentação extrativa é um processo digno a ser substituto das etapas iniciais de separação convencionais.(AU)

Fibrinolytic enzymes can be obtained from microorganisms through fermentative processes. The study aimed to evaluate the fibrinolytic protease production and integrated extraction from Mucor subtilissimus UCP 1262 by extractive fermentation using Aqueous Two-Phase Systems (ATPS). The integrated process was carried out to assess the production, partition and fibrinolytic enzyme recovery, according to a 2 3 -experimental design, using as independent variables Polyethylene glycol (PEG) molar mass, PEG and sodium sulphate concentration, concentration. The highest fibrinolytic activity (15.40U/mL) was obtained in sodium sulfate rich phase in the assay comprising of 10% of salt and 18% of PEG 8000 (g/mol). Yield greater than 80% was obtained. The fibrinolytic protease presented optimum pH 7.0 and stability between pH 6.0 and 8.5, and optimum temperature 50°C, stable between 10°C to 50°C. The enzyme was classified as a serine-protease with 52kDa of molecular weight. As a result, the process is remarkably effective to pre-purify the fibrinolytic protease with a low cost and significantly faster processing time. When compared to other isolated production and purification techniques the extractive fermentation is worthy of being a candidate to replace the initial stages of conventional separation processes.(AU)

Diagnostic Significance of Fibrin Degradation Products and D-Dimer in Patients With Breast Cancer-Related Lymphedema

OBJECTIVE: To find out whether levels of fibrin degradation products (FDP) and D-dimer are increased in breast cancer-related lymphedema (BCRL) as in many vascular diseases. FDP and D-dimer have been used in blood tests to help differentiate deep vein thrombosis in the diagnosis of lymphedema. Levels of FDP and D-dimer are often elevated in patients with BCRL. METHODS: Patients with BCRL (group I), non-lymphedema after breast cancer treatment (group II), and deep venous thrombosis (group III) from January 2012 to December 2016 were enrolled. Levels of FDP and D-dimer were measured in all groups and compared among groups. RESULTS: Mean values of FDP and D-dimer of group I were 5.614±12.387 and 1.179±2.408 μg/μL, respectively. These were significantly higher than their upper normal limits set in our institution. Levels of FDP or D-dimer were not significantly different between group I and group II. However, values of FDP and D-dimer in group III were significantly higher than those in group I. CONCLUSION: Values of FDP and D-dimer were much higher in patients with thrombotic disease than those in patients with lymphedema. Thus, FDP and D-dimer can be used to differentiate between DVT and lymphedema. However, elevated levels of FDP or D-dimer cannot indicate the occurrence of lymphedema.

Fibrin biopolymer as scaffold candidate to treat bone defects in rats

Bone tissue repair remains a challenge in tissue engineering. Currently, new materials are being applied and often integrated with live cells and biological scaffolds. The fibrin biopolymer (FBP) proposed in this study has hemostatic, sealant, adhesive, scaffolding and drug-delivery properties. The regenerative potential of an association of FBP, biphasic calcium phosphate (BCP) and mesenchymal stem cells (MSCs) was evaluated in defects of rat femurs. Methods: Adult male Wistar rats were submitted to a 5-mm defect in the femur. This was filled with the following materials and/or associations: BPC; FBP and BCP; FBP and MSCs; and BCP, FBP and MSCs. Bone defect without filling was defined as the control group. Thirty and sixty days after the procedure, animals were euthanatized and subjected to computed tomography, scanning electron microscopy and qualitative and quantitative histological analysis. Results: It was shown that FBP is a suitable scaffold for bone defects due to the formation of a stable clot that facilitates the handling and optimizes the surgical procedures, allowing also cell adhesion and proliferation. The association between the materials was biocompatible. Progressive deposition of bone matrix was higher in the group treated with FBP and MSCs. Differentiation of mesenchymal stem cells into osteogenic lineage was not necessary to stimulate bone formation. Conclusions: FBP proved to be an excellent scaffold candidate for bone repair therapies due to application ease and biocompatibility with synthetic calcium-based materials. The satisfactory results obtained by the association of FBP with MSCs may provide a more effective and less costly new approach for bone tissue engineering.(AU)

Unique heterologous fibrin biopolymer with hemostatic, adhesive, sealant, scaffold and drug delivery properties: a systematic review

Fibrin biopolymers, previously referred as "fibrin glue" or "fibrin sealants", are natural biomaterials with diverse applications on health. They have hemostatic, adhesive, sealant, scaffold and drug delivery properties and have become widely used in medical and dental procedures. Historically, these biomaterials are produced from human fibrinogen and human or animal thrombin, and the possibility of transmission of infectious diseases by human blood is not ruled out. In the 1990s, to overcome this problem, a new heterologous biomaterial composed of a thrombin-like enzyme purified from Crotalus durissus terrificus venom and a cryoprecipitate rich in fibrinogen extracted from buffaloes Bubalus bubalis blood has been proposed. Therefore, a systematic review of studies on exclusively heterologous fibrin sealants published between 1989 and 2018 was carried out using the following databases: PubMed, SciELO and Google Scholar. The keyword used was "heterologous fibrin sealant". The search resulted in 35 scientific papers in PubMed, four in SciELO and 674 in Google Scholar. After applying the inclusion/exclusion criteria and complete reading of the articles, 30 studies were selected, which formed the basis of this systematic review. It has been observed that the only completely heterologous sealant is the one produced by CEVAP/UNESP. This heterologous biopolymer is proven effective by several studies published in refereed scientific journals. In addition, clinical trials phase I/II for the treatment of chronic venous ulcers authorized by the Brazilian Health Regulatory Agency (ANVISA) were completed. Preliminary results have indicated a safe and promising effective product. Phase III clinical trials will be proposed and required to validate these preliminary findings.(AU)

Socket preservation using eggshell-derived nanohydroxyapatite with platelet-rich fibrin as a barrier membrane: a new technique

OBJECTIVES: Socket grafting is vital to prevent bone resorption after tooth extraction. Several techniques to prevent resorption have been described, and various bone graft substitutes have been developed and used with varying success. We conducted this pilot study to evaluate the performance of nanohydroxyapatite (nHA) derived from chicken eggshells in socket preservation.MATERIALS AND METHODS: This was a prospective, single center, outcome assessor-blinded evaluation of 23 sockets (11 patients) grafted with nHA and covered with platelet-rich fibrin (PRF) membrane as a barrier. Bone width and radiographic bone density were measured using digital radiographs at 1, 12, and 24 weeks post-procedure. Postoperative histomorphometric and micro-computed tomography (CT) evaluation were performed. The study protocol was approved by the Institutional Ethics Committee.RESULTS: All patients had uneventful wound healing without graft material displacement or leaching despite partial exposure of the grafted socket. Tissuere-epithelialized with thick gingival biotype (>3 mm). Width of the bone was maintained and radiographic density increased significantly with a trabecular pattern (73.91% of sockets) within 12 weeks. Histomorphometric analysis showed 56.52% Grade 3 bone formation and micro-CT analysis revealed newly formed bone with interconnecting trabeculae.CONCLUSION: Use of a PRF membrane with nHA resulted in good bone regeneration in sockets. Use of a PRF membrane prevents periosteal-releasing incisions for primary closure, thereby facilitating the preservation of keratinized mucosa and gingival architecture. This technique, which uses eggshell-derived nHA and PRF membrane from the patient's own blood, is innovative and is free of disease transfer risks. nHA is a promising economic bone graft substitute for bone regeneration and reconstruction because of the abundant availability of eggshell waste as a raw material.

Platelet-rich fibrin along with a modified minimally invasive surgical technique for the treatment of intrabony defects: a randomized clinical trial

PURPOSE: The modified minimally invasive surgical technique (M-MIST) has been successfully employed to achieve periodontal regeneration. Platelet-rich fibrin (PRF) is known to enhance wound healing through the release of growth factors. This study aimed to observe the outcomes of periodontal surgery when M-MIST was used with or without PRF for the treatment of isolated intrabony defects.METHODS: This randomized clinical trial was conducted on 36 systemically healthy patients, who had chronic periodontitis associated with a single-site buccal probing pocket depth (PPD) and clinical attachment level of ≥5 mm. Patients were randomly divided into 2 groups: the test group treated with M-MIST and PRF, and the control group treated with M-MIST alone. The primary periodontal parameters analyzed were PPD, relative attachment level (RAL), and relative gingival margin level. The radiographic parameters analyzed were change in alveolar crest position (C-ACP), linear bone growth (LBG), and percentage bone fill (%BF). Patients were followed up to 6 months post-surgery.RESULTS: Intragroup comparisons at 3 and 6 months showed consistently significant improvements in PPD and RAL in both the groups. In intergroup comparisons, the improvement in PPD reduction, gain in RAL, and the level of the gingival margin was similar in both groups at 3 and 6 months of follow-up. Furthermore, an intergroup comparison of radiographic parameters also demonstrated similar improvements in C-ACP, LBG, and %BF at 6 months of follow-up.CONCLUSIONS: M-MIST with or without PRF yielded comparable periodontal tissue healing in terms of improvements in periodontal and radiographic parameters. Further investigation is required to confirm the beneficial effects of PRF with M-MIST.TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03169920

Repair of Osteochondral Defects in Rabbit Knee Using Menstrual Blood Stem Cells Encapsulated in Fibrin Glue: A Good Stem Cell Candidate for the Treatment of Osteochondral Defects

BACKGROUND: In recent years, researchers discovered that menstrual blood-derived stem cells (MenSCs) have the potential to differentiate into a wide range of tissues including the chondrogenic lineage. In this study, we aimed to investigate the effect of MenSCs encapsulated in fibrin glue (FG) on healing of osteochondral defect in rabbit model. METHODS: We examined the effectiveness of MenSCs encapsulated in FG in comparison with FG alone in the repair of osteochondral defect (OCD) lesions of rabbit knees after 12 and 24 weeks. RESULTS: Macroscopical evaluation revealed that the effectiveness of MenSCs incorporation with FG is much higher than FG alone in repair of OCD defects. Indeed, histopathological evaluation of FG + MenSCs group at 12 weeks post-transplantation demonstrated that defects were filled with hyaline cartilage-like tissue with proper integration, high content of glycosaminoglycan and the existence of collagen fibers especially collagen type II, as well as by passing time (24 weeks post-transplantation), the most regenerated tissue in FG + MenSCs group was similar to hyaline cartilage with relatively good infill and integration. As the same with the result of 12 weeks post-implantation, the total point of microscopical examination in FG + MenSCs group was higher than other experimental groups, however, no significant difference was detected between groups at 24 weeks (p>0.05). CONCLUSION: In summary, MenSCs as unique stem cell population, is suitable for in vivo repair of OCD defects and promising for the future clinical application.

Reduction in post extraction waiting period for dental implant patients using plasma rich in growth factors: an in vivo study using cone-beam computed tomography

OBJECTIVES: This study examined the effects of plasma-rich growth factors (PRGF) on accelerating bone regeneration/repair in fresh extraction sockets, and determined the quality and quantity of bone by assessing the bone density using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Twenty patients, who had undergone bilateral extractions, were included in this study. In one extraction socket, PRGF was used and covered with an autologous fibrin plug. Nothing was used in the opposite side extraction socket. Thirteen weeks post extraction, the level of bone regeneration was evaluated on both sides with CBCT. RESULTS: At the end of the study, the mean bone density according to the Hounsfield units (HU) in the control group and PRGF group was 500.05 HU (type III bone type) and 647.95 HU (type II bone type), respectively. CONCLUSION: This study recommends the use of PRGF in post extraction sites to accelerate the rate of bone regeneration and improve the quality of regenerated bone. The technique to process PRGF was simple compared to previously mentioned techniques used for platelet-rich plasma (PRP) preparation. PRP preparation requires a two-cycle centrifugation procedure, leading to a longer processing time.

Use of platelet-rich fibrin and natural bone regeneration in regenerative surgery

No abstract available.