Cleuza Mf Rezende

Intra-articular injections of autologous platelet concentrates in dogs with surgical reparation of cranial cruciate ligament rupture

OBJECTIVES The objective of this study was to evaluate by clinical, radiographic, and force plate gait analyses the effect of post-surgical intra-articular injections of autologous platelet concentrates (PC) in a small group of dogs with cranial cruciate ligament (CCL) rupture. METHODS The ten dogs used in this study were initially presented with CCL rupture and underwent ligament replacement surgery by fascia lata autograft guided by arthroscopy. Six dogs received three intra-articular injections of PC (PC group); one dose was injected immediately after surgery, and two additional doses were injected at two-week intervals. The remaining four dogs received only nutraceuticals (control group). All dogs were evaluated by clinical examination, serial radiography, and force plate gait analyses at monthly intervals up to 90 days. RESULTS The clinical follow-up of the PC-treated group indicated a better outcome than the control group. Radiographic evaluation was not conclusive. Values of peak vertical reaction force and vertical impulse of the affected limbs were only significantly larger on the 90th postoperative day in the PC group compared to the control group. CLINICAL SIGNIFICANCE Our results indicate that autologous PC might improve functional outcome after intra-articular cranial cruciate ligament repair. The effect of PC when using other repair procedures warrants additional studies.

In vivo evaluation of bioactive glass foams associated with platelet-rich plasma in bone defects.

The objective of this study was to evaluate the use of bioactive glass foams produced by the sol–gel process, associated or not with platelet‐rich plasma (PRP), in the regeneration of bone defects. Mongrel dogs (n = 14) were divided into two groups after having their superior first premolar removed. A small piece of vestibular bone from the alveolus was intentionally removed. The area was filled with bioactive glass foam produced by the sol–gel method. Two groups were tested: group A was the glass foam; group B was the same material associated with PRP, prepared from each animal. The other side of alveolar bone was used as a control group, in which the bone defect did not receive any biomaterial. The thickness of the bone area was measured before and after the intervention. After a period of 60 days implantation, the right and left bones were measured again, and a bone biopsy on both regions was conducted for histological analysis. The findings show an increase of bone thickness for both materials implanted compared to the control group. Group B, implanted with bioactive glass foam associated with PRP, showed a thicker bone area compared to Group A. Histological results indicate bone formation for both materials used. However, the bioactive glass associated with PRP gave rise to a more mature bone formation. These results show that bioactive glass foams processed by a sol–gel method is effective in maintaining the thickness of the alveolar ridge, and the use of PRP associated with the foams improve bone formation. Copyright

Evaluación del método del tubo para concentrar plaquetas felinas: estudio celular

SUMMARY The aim of this study was to evaluate a manual method for concentrating canine platelets and consequently produce autologous platelet concentrates (APCs) for clinical and experimental proposals. The APCs were obtained by venous blood collection in tubes with ACD solution and were spun at 191 g for 6 minutes. The cell counts of whole blood and APCs, were statistically different (P < 0.01) between the values for platelets, leukocytes, granulocytes, monocytes, but not for lymphocytes. A strong negative correlation (ρ = -0.702 P = 0.011) between the number of lymphocytes and platelets in the APCs was found. The collection efficiency of platelets was 29.9% and the concentration of platelets was 49.4% higher in APCs when compared to the whole blood samples. The results indicated that this simple centrifugation method allows concentrating canine platelets.

Comparison of the osteogenic potential of mesenchymal stem cells from the bone marrow and adipose tissue of young dogs

BackgroundThe aim of the present study was to compare the osteogenic potential of mesenchymal stem cells extracted from the bone marrow (BM-MSCs) and adipose tissue (AD-MSCs) of young dogs. The following parameters were assessed: dimethyl thiazolyl diphenyl tetrazolium (MTT) conversion, alkaline phosphatase (ALP) activity, collagen and mineralised matrix synthesis, and the expressions of osterix, bone sialoprotein (BSP), and osteocalcin (OC).ResultsMTT conversion was greater in BM-MSCs compared to AD-MSCs after 14 and 21 days of differentiation; ALP activity was greater in differentiated AD-MSCs on day 7; collagen synthesis was greater in BM-MSCs on days 14 and 21; the percentage of mineralized area per field was greater in BM-MSCs compared to AD-MSCs; osterix expression was greater in BM-MSCs in days 14 and 21, and BSP and OC expression levels were greater in BM-MSCs at all the investigation time-points.ConclusionsIt was concluded that the osteogenic potential was greater in BM-MSCs than AD-MSCs when extracted from young dogs.

Comparison of the effect of calcium gluconate and batroxobin on the release of transforming growth factor beta 1 in canine platelet concentrates

BackgroundThe clinical use of autologous platelet concentrates (also known as platelet-rich plasma) on the field of regenerative therapy, in the last decade has been the subject of several studies especially in equine medicine and surgery. The objectives of this study was: 1) to describe and compare the cellular population in whole blood, lower fraction (A) and upper fraction (B) of platelet concentrates, 2) to measure and compare the transforming growth factor beta 1 (TGF-β1) concentration in plasma and both platelet concentrates after be activated with calcium gluconate or batroxobin plus calcium gluconate and, 3) to determine correlations between cell counts in platelet concentrates and concentrations of TGF-β1. Blood samples were taken from 16 dogs for complete blood count, plasma collection and platelet concentrates preparation. The platelet concentrates (PC) were arbitrarily divided into two fractions, specifically, PC-A (lower fraction) and PC-B (upper fraction). The Platelet concentrates were analyzed by hemogram. After activated with calcium gluconate or batroxobin plus calcium gluconate, TGF-β1 concentration was determined in supernatants of platelet concentrates and plasma.ResultsThere were differences statistically significant (P < 0.05) for the platelet count and leukocyte count and TGF-β1 concentration between whole blood, plasma and both platelet concentrates. A significant correlation was found between the number of platelets in both platelet concentrates and TGF-β1 concentration. Platelet collection efficiency was 46.34% and 28.16% for PC-A and PC-B, respectively. TGF-β1 concentration efficiency for PC activated with calcium gluconate was 47.75% and 31.77%, for PC-A and PC-B, respectively. PC activated with batroxobin plus CG showed 46.87% and 32.24% for PC-A and PC-B, respectively.ConclusionsThe methodology used in this study allows the concentration of a number of platelets and TGF-β1 that might be acceptable for a biological effect for clinical or experimental use as a regenerative therapy in dogs.

Evaluation of the effect of calcium gluconate and bovine thrombin on the temporal release of transforming growth factor beta 1 and platelet-derived growth factor isoform BB from feline platelet concentrates.

BackgroundThere are not reported regarding the protocols for obtaining platelet concentrates (PC) in cats for medical purposes. The objectives of this study were: 1) to describe a manual method for producing two kinds of PC in cats (PC-A and PC-B), 2) to describe the cellular population of the PC, 3) to measure and compare the effect of calcium gluconate (CG) and bovine thrombin (BT) on the temporal release of transforming growth factor beta 1 (TGF-β1) and platelet-derived growth factor type BB (PDGF-BB) at 3 and 12 hours post-activation and 4) to establish correlations between the cellular population of both PCs and the concentration of growth factors (GF). Blood samples were taken from 16 cats for complete blood count, plasma collection and PC preparation. The PC were arbitrarily divided into two fractions, specifically, PC-A (lower fraction) and PC-B (upper fraction).ResultsThe platelet counts were significantly different (P<0.05) between the PC and whole blood but not between the PC fractions. The TGF-β1 concentration efficiencies for PC-A and PC-B activated with CG were 42.86% and 46.54%, and activated with BT were 42.88% and 54.64%, respectively. The PDGF-BB concentration efficiencies for PC-A and PC-B activated with CG were 61.36% and 60.61%, and activated with BT were 65.64% and 72.12%, respectively. The temporal release of GFs showed no statistically significant difference (P>0.05) between the activating substances at the time or for any PC fraction.ConclusionsWhatever the activation means, these preparations of cat PC provide significant concentrations of platelets and GFs for possible clinical or experimental use.

Ultrastructural characteristics of fibrin clots from canine and feline platelet concentrates activated with calcium gluconate or calcium gluconate plus batroxobin

BackgroundThe aim of this study was to use transmission electron microscopy to describe the ultrastructural characteristics of clots obtained from canine and feline platelet concentrates (PC) that had been activated with calcium gluconate (CG) or CG plus batroxobin (CGB). Platelets from fibrin clots were classified according their morphological changes. The area of the intercellular space (μm2), the area of the fibrin fibers (μm2), and the width of the fibrin fibers (μm) were determined for the dog clots. The platelet area (μm2), the area of fibrin fibers (μm2), the ratio of the minor and major axes of platelets, the ratio of the major and minor axes of platelets, and the number of α-granules found within platelets were measured for the cat clots.ResultsCat platelets displayed full activation. Dog platelets displayed lysis with loss of normal architecture. In both species, a statistically significant difference was found (P < 0.01) between the fibrin fiber measurements in the PC clots activated with CG and CGB.ConclusionsThe findings suggest that activation with CG caused platelet alpha granules to release their contents. In cats, fibrin production was greater when the PC was activated with CG. In dogs, activation with CG produced thick fibrin fibers.

Estudo comparativo da diferenciação osteogênica das células tronco mesenquimais da medula óssea e do tecido adiposo de cães adultos

O objetivo deste estudo foi comparar o potencial osteogenico das celulas tronco mesenquimais extraidas da medula ossea (CTM-MO) com as do tecido adiposo (CTM-AD) de caes adultos. As celulas foram caracterizadas fenotipicamente quanto a expressao de CD29, CD90, CD34 e CD45 e submetidas a diferenciacao adipogenica e condrogenica por 21 dias e osteogenica por 7, 14 e 21 dias. Foram constituidos quatro grupos: 1) CTM-MO em meio osteogenico, 2) CTM-MO em meio basal, 3) CTM-AD em meio osteogenico e 4) CTM-AD em meio basal. Aos 7, 14 e 21 dias de diferenciacao osteogenica as culturas foram submetidas as avaliacoes da conversao de MTT em formazan, da atividade da fosfatase alcalina (FA), da sintese de colageno e de matriz mineralizada, avaliacao do numero de celulas por campo e foram quantificados os transcritos genicos para osterix, sialoproteina ossea (BSP), osteonectina (ON) e osteocalcina (OC). Tanto as celulas extraidas da medula ossea quanto do tecido adiposo mostraram elevada expressao de marcadores para celulas tronco e baixa expressao de marcadores de celulas hematopoieticas (menor que 2%). Alem disso, foram capazes de se diferenciar em osteoblastos, condrocitos e adipocitos. As CTM-AD submetidas a diferenciacao osteogenica mostraram maior conversao do MTT em formazan que as CTM-MO, sob mesmas condicoes aos 7 e 21 dias. O numero de celulas por campo, a atividade da FA, a sintese de colageno e de matriz mineralizada foram superior nas CTM-AD em diferenciacao, em relacao as CTM-MO sob as mesmas condicoes, em todos os tempos estudados. As expressoes de osterix, BSP e OC foram predominantemente superiores nas CTM-MO diferenciadas, mas a expressao de ON foi superior nas CTM-AD diferenciadas aos 7, 14 e 21 dias. Conclui-se que as CTM-AD apresentam maior potencial osteogenico que as CTM-MO quando extraidas de caes adultos.

Características radiográficas, artroscópicas y biomecánicas de perros con ruptura del ligamento cruzado anterior

Resumen es: Los objetivos de este estudio fueron describir los signos clinicos asociados con alteraciones de la marcha, y correlacionar los resultados del examen rad...

Use of intra-articular autologous platelet concentrates as coadjutants in the surgical arthroscopy treatment of elbow dysplasia in a bitch

RESUMEN La displasia del codo canino (CED) es un complejo de enfermedades que resultan en (OA) osteoartritis. CED incluye la no union del proceso anconeo (UAP), fragmentacion del proceso coronoides medial (FMCP), osteocondritis (OC) del condilo medial del humero e incongruencia del codo. Una perra con OC del condilo medial del humero y FMCP fue tratada por artroscopia mediante microfracturas del hueso subcondral y remocion, respectivamente, y recibio dosis intra-articulares de concentrados autologos de plaquetas (APC). La paciente fue evaluada mediante examen clinico, citologia del liquido sinovial, evaluacion radiografica y evaluacion en plataforma de fuerza, antes de la cirugia y a los 15, 30, 60 y 90 dias postoperatorios. La paciente alcanzo recuperacion clinica completa al 60 dia postoperatorio, acompanado de mejoria en la citologia del liquido sinovial y en los resultados cinematicos. Sin embargo, la evaluacion radiologica mostro un leve desarrollo de OA. Los resultados de este informe pueden sugerir el potencial de uso de APC como una terapia de accion modificadora sintomatica en el tratamiento de OA secundaria a la displasia de codo en el perro.