Structural and functional properties of Bp-LAAO, a new L-amino acid oxidase isolated from Bothrops pauloensis snake venom

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Gel de plaquetas: arcabouço 3D para cultura celular

INTRODUÇÃO: O reparo tissular é o objetivo final da cirurgia. A cultura celular requer arcabouço mecânico que dê suporte ao crescimento celular e difusão dos nutrientes. O uso do plasma rico em plaquetas (PRP) como um arcabouço 3D possui diversas vantagens: é material biológico, de fácil absorção pós-transplante, rico em fatores de crescimento, em especial PDGF- ββ e TGF-β que estimula síntese de matriz extracelular na cartilagem. OBJETIVO: Desenvolver arcabouço 3D à base de PRP. MATERIAIS E MÉTODOS: Duas formas foram idealizadas: Sphere e Carpet. Condições estéreis foram utilizadas. O gel de plaquetas permaneceu em cultura celular, observado diariamente em microscópio invertido. RESULTADOS: Ambos arcabouços obtiveram sucesso, com aspectos positivos e negativos. DISCUSSÃO: A forma Sphere não aderiu ao plástico. Observou-se retração do gel e investigação ao microscópio dificultada devido às áreas opacas no campo visual. A forma Carpet não aderiu ao plástico e apresentou-se translúcida. O tempo de estudo foi de 20 dias. CONCLUSÕES: A produção de um arcabouço 3D PRP foi um sucesso, e trata-se de uma alternativa que necessita ser mais utilizado e investigado para que se consolide em uma rota eficiente e confiável na tecnologia de engenharia tissular, particularmente em cultura de tecido cartilaginoso.

Management of Osteonecrosis of the Jaws in Patients With History of Bisphosphonates Therapy

Bisphosphonates are compounds used in the treatment of various metabolic and malignant bone diseases. The relation between the use of bisphosphonates and ostenonecrosis of the jaws as an adverse effect of the drug has been intensely discussed during the last few years, and up to this moment, there is no consensus concerning an ideal treatment modality for this condition. Nevertheless, there is an agreement among researchers that the standard goal for controlling jaw osteonecrosis is to prevent it. Otherwise, the rationale for a randomized controlled trial is that current treatment has proven to be suboptimal, and no consensus has been reached yet on the best strategies to repair the exposed bone once bone necrosis is developed. This article is focused on reporting a case of moderate osteonecrosis of the upper jaw induced by bisphosphonates and discusses a possible role for surgical debridement associated to platelet-rich plasma, hyperbaric oxygen therapy, and the cessation of the bisphosphonate use in managing this type of lesion. Moreover, the dentist, the oral surgeon, and the oncologist need to work together to reach better outcomes.

Blood cells attachment after root conditioning and PRP application: An in vitro study

Aim: Root conditioning is aimed at smear layer removal and at dental matrix collagen exposure, which may promote periodontal regeneration. This in vitro study assessed smear layer removal, collagen fiber exposure and the influence of PRP (platelet-rich plasma) application on adhesion of blood cells to the root surface using scanning electron microscopy (SEM). Materials and methods: Scaled root samples (n = 160) were set in five groups and conditioned with: group I - control group (saline solution); group II (EDTA 24%); group III (citric acid 25%); group IV (tetracycline hydrochloride 50 mg/ml); group V (sodium citrate 30%). Eighty samples were assessed using the root surface modification index (RSMI). The other eighty samples were set in two groups. The first group (n = 40) received PRP gel application with a soft brush and the second group (n = 40) received PRP application and then a blood drop. The fibrin clot formation was assessed in the first group and the blood cells adhesion was assessed in the second group using the BEAI (blood elements adhesion index). A previously trained, calibrated, and blind examiner evaluated photomicrographs. Statistical analysis was performed using the Kruskal-Wallis's and Dunn's tests. Results: Group III attained the best results for RSMI and BEAI. Moreover, it was the only group showing fibrin clot formation. Conclusion: Citric acid was the most efficient conditioner for smear layer removal, collagen fiber exposure and blood cell adhesion. Moreover, it was the only group showing fibrin clot formation after PRP application. Clinical significance: This study demonstrated that root conditioning followed by PRP application may favor blood cell adhesion on root surface which may optimize periodontal healing.

Histologic Characterization of Engineered Tissues in the Canal Space of Closed-apex Teeth with Apical Periodontitis

Introduction: The aim of this study was to investigate the capacity of endodontic regenerative procedures combining an induced blood clot, platelet-rich plasma (PRP), and bone marrow aspirate (BMA) to regenerate dental pulp in canine closed-apex necrotic teeth. Methods: Apical periodontitis was induced in 20 upper and lower premolars of 2 dogs. After biomechanical preparation, enlargement to a #60 file, and disinfection with a triantibiotic paste for 28 days, the roots were randomly assigned to 4 treatment groups: blood clot (BC), BC + PRP gel, BC + BMA gel, and BC + BMA/PRP gel. Negative controls were also included. After a 3-month follow-up period, the animals were killed. Results: Histologic analysis showed the presence of newly formed vital tissues (connective, cement-like, and bone-like tissue) in 23 of the 32 treated roots (71.87%). There was no statistically significant difference between the treatment groups. Conclusions: New vital tissues were formed and characterized as connective, cementum-like, or bone-like, but not as pulp-like tissue; PRP and/or BMA did not improve the tissue ingrowth. © 2013 American Association of Endodontists.

Potencial imunogênico dos curativos bioativos: aspectos imunhematológicos e leucoplaquetários

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Treatment of osteochondral injuries with platelet gel

OBJECTIVES: Treatments for injured articular cartilage have not advanced to the point that efficient regeneration is possible. However, there has been an increase in the use of platelet-rich plasma for the treatment of several orthopedic disorders, including chondral injuries. Our hypothesis is that the treatment of chondral injuries with platelet gel results in higher-quality repair tissue after 180 days compared with chondral injuries not treated with gel.METHODS: A controlled experimental laboratory study was performed on 30 male rabbits to evaluate osteochondral injury repair after treatment with or without platelet gel. Osteochondral injuries were surgically induced in both knees of each rabbit at the medial femoral condyle. The left knee injury was filled with the platelet gel, and the right knee was not treated. Microscopic analysis of both knee samples was performed after 180 days using a histological grading scale.RESULTS: The only histological evaluation criterion that was not significantly different between treatments was metachromasia. The group that was treated with platelet gel exhibited superior results in all other criteria (cell morphology, surface regularity, chondral thickness and repair tissue integration) and in the total score.CONCLUSION: The repair tissue was histologically superior after 180 days in the study group treated with platelet gel compared with the group of untreated injuries.

Avaliação histológica de estratégias de engenharia tecidual para a terapia endodôntica

Pós-graduação em Ciência Odontólogica - FOA

Fatores indutores e supressores da eritropoiese em caninos doentes renais crônicos

Pós-graduação em Cirurgia Veterinária - FCAV

Adesão de células sanguineas em raízes biomodificadas de pacientes fumantes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Diferentes terapias na osteoartrite induzida por papaína em joelhos de ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Endophenotypes and serotonergic polymorphisms associated with treatment response in obsessive-compulsive disorder

OBJECTIVES: Approximately 40-60% of obsessive-compulsive disorder patients are nonresponsive to serotonin reuptake inhibitors. Genetic markers associated with treatment response remain largely unknown. We aimed (1) to investigate a possible association of serotonergic polymorphisms in obsessive-compulsive disorder patients and therapeutic response to selective serotonin reuptake inhibitors and (2) to examine the relationship between these polymorphisms and endocrine response to intravenous citalopram challenge in responders and non-responders to serotonin reuptake inhibitors and in healthy volunteers. METHODS: Patients with obsessive-compulsive disorder were classified as either responders or non-responders after long-term treatment with serotonin reuptake inhibitors, and both groups were compared with a control group of healthy volunteers. The investigated genetic markers were the G861C polymorphism of the serotonin receptor 1D beta gene and the T102C and C516T polymorphisms of the serotonin receptor subtype 2A gene. RESULTS: The T allele of the serotonin receptor subtype 2A T102C polymorphism was more frequent among obsessive-compulsive disorder patients (responders and non-responders) than in the controls (p<0.01). The CC genotype of the serotonin receptor subtype 2A C516T polymorphism was more frequent among the non-responders than in the responders (p<0.01). The CC genotype of the serotonin receptor subtype 1D beta G681C polymorphism was associated with higher cortisol and prolactin responses to citalopram (p<0.01 and p<0.001, respectively) and with a higher platelet-rich plasma serotonin concentration among the controls (p<0.05). However, this pattern was not observed in the non-responders with the same CC genotype after chronic treatment with serotonin reuptake inhibitors. This CC homozygosity was not observed in the responders.

A bayesian network meta-analysis on comparisons of enamel matrix derivatives, guided tissue regeneration and their combination therapies

Aims: Guided tissue regeneration (GTR) and enamel matrix derivatives (EMD) are two popular regenerative treatments for periodontal infrabony lesions. Both have been used in conjunction with other regenerative materials. We conducted a Bayesian network meta-analysis of randomized controlled trials on treatment effects of GTR, EMD and their combination therapies. Material and Methods: A systematic literature search was conducted using the Medline, EMBASE, LILACS and CENTRAL databases up to and including June 2011. Treatment outcomes were changes in probing pocket depth (PPD), clinical attachment level (CAL) and infrabony defect depth. Different types of bone grafts were treated as one group and so were barrier membranes. Results: A total of 53 studies were included in this review, and we found small differences between regenerative therapies which were non-significant statistically and clinically. GTR and GTR-related combination therapies achieved greater PPD reduction than EMD and EMD-related combination therapies. Combination therapies achieved slightly greater CAL gain than the use of EMD or GTR alone. GTR with BG achieved greatest defect fill. Conclusion: Combination therapies performed better than single therapies, but the additional benefits were small. Bayesian network meta-analysis is a promising technique to compare multiple treatments. Further analysis of methodological characteristics will be required prior to clinical recommendations.

Association of laser phototherapy with PRP improves healing of bisphosphonate-related osteonecrosis of the jaws in cancer patients: A preliminary study

The aim of this study was to compare retrospectively the effect of three different treatments on the healing outcome of bisphosphonate-related osteonecrosis of the jaws (BRONJ) in cancer patients. Twenty-two cancer patients were treated for BRONJ with one of the following protocols: clinical (pharmacological therapy), surgical (pharmacological plus surgical therapy), or PRP plus LPT (pharmacological plus surgical plus platelet rich plasma (PRP) plus laser phototherapy (LPT). The laser treatment was applied with a continuous diode laser (InGaAlP, 660 nm) using punctual and contact mode, 40 mW, spot size 0.042 cm(2), 6 J/cm(2) (6 s) and total energy of 0.24 J per point. The irradiations were performed on the exposed bone and surrounding soft tissue. The analysis of demographic data and risk factors was performed by gathering the following information: age, gender, primary tumor, bisphosphonate (BP) used, duration of BP intake, history of chemotherapy, use of steroids, and medical history of diabetes. The association between the current state of BRONJ (with or without bone exposure) and other qualitative variables was determined using the chi-square or Fisher's exact test. In all tests, the significance level adopted was 5%. Most BRONJ lesions occurred in the mandible (77%) after tooth extraction (55%) and in women (72%). A significantly higher percentage of patients reached the current state of BRONJ without bone exposure (86%) in the PPR plus LPT group than in the pharmacological (0%) and surgical (40%) groups after 1-month follow-up assessment. These results suggest that the association of pharmacological therapy and surgical therapy with PRP plus LPT significantly improves BRONJ healing in oncologic patients. Although prospective studies with larger sample sizes are still needed, this preliminary study may be used to inform a better-designed future study. (C) 2011 Elsevier Ltd. All rights reserved.

Efficacia del trattamento con concentrati piastrinici (P.R.P.) nelle lesioni condrali e tendinopatie

Purpose: Recent knowledge regarding tissue biology highlights a complex regulation of growth factors in reaction to tissue damage. Platelet Rich Plasma (P.R.P.), containing a natural pool of growth factors, can be obtained in a simple and minimally invasive way and be applied to the lesion site. The aim of this study is to explore this novel approach to treat cartilage degenerative lesions of the knee and tendon chronic lesions( patellar tendon, and achilles tendon). In this study we evaluated if the treatment with PRP injections can reduce pain and increase function in cases of patellar tendinosis (Jumper’s Knee), in chronic achilles tendinopathy and in patients with cartilage injuries of the knee. Materials and Methods: 40 patients with cartilage lesion of the knee, 28 male and 12 female with mean age 47 y. (min 18- max 52 years), were treated and prospectively evaluated at a minimum 6 months follow-up; in the same way, 12 patients with achilles tendon lesion (8 male and 4 female) with mean age 44,5 y. (min 32-max 58 years) and 10 patients with “Jumper’s Knee” (8 male and 2 female) with mean age 23,2 y. (min 18-max 37 years), were evaluated at 6 months follow up. The procedure involved 3 multiple injections , performed every two weeks. All patients were clinically evaluated at the end of the treatment and at 6 months follow up. IKDC, SF36, EQ-VAS, scores were used for clinical evaluation and patient satisfaction and functional status were also recorded. Results: Statistical analysis showed a significant improvement in the SF36 questionnaire in all parameters evaluated at the end of the therapy and 6 months follow-up in both group(tendinopathies and chondral lesions), and in the EQ VAS and IKDC score (paired T-test, p<0.0005) from basal evaluation to the end of the therapy, and a further improvement was present at 6 months follow-up. Whereas a higher improvement of the sport activity level was achieved in the “Jumper’s Knee” group. No complications related to the injections or severe adverse events were observed during the treatment and follow up period. Conclusion: PRP inhibits excess inflammation, apoptosis, and metalloproteinase activity. These interactive pathways may result in the restoration of tendon or cartilage, which can with stand loading with work or sports activity, thereby diminishing pain. PRP may also modulate the microvascular environment or alter efferent or afferent neural receptors. The clinical results are encouraging, indicating that PRP injections may have the potential to increase the tendon and cartilage healing capacity in cases with chronic tendinosis and chondropathy of the knee.