E.G.L. Alves

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.

Emprego experimental da placa de compósito poli-hidroxibutirado/hidroxiapatita na fixação femoral em gatos

The composite of polyhydroxybutyrate (PHB) 70% and hydroxyapatite (HA) 30% was evaluated as plate for bone fixation in cats. The employed composite plates presented six orifices and measured 60 x 10mm, length and width, respectively, with thickness ranging from 3 to 5mm according to the region. The composite plate was used in the fixation of femoral osteotomy in four cats, in a total of six interventions. There were ruptures in five plates (83.3%) until day 4 and in one plate (16.7%) on the day 21, when it was possible to observe an exuberant osseous callus. The result of the plate deployment in the cat showed that the composite does not have sufficient strength to be used as plate of femoral fixation in cats.

Modelo experimental de trauma medular agudo produzido por aparelho estereotáxico modificado

Foram utilizados 55 ratos machos da especie Rattus novergicus, variedade Wistar, com o objetivo de propor um modelo experimental de trauma medular produzido por aparelho estereotaxico modificado, capaz de reproduzir clinicamente lesoes medulares padronizadas. Apos realizacao de laminectomia dorsal de T13, utilizou-se peso compressivo de 50,5g (25 animais - grupo I) ou 70,5g (30 animais - grupo II), durante cinco minutos, comprimindo a medula espinhal. Os animais foram assistidos durante oito dias, por meio de testes comportamentais para avaliar a sensibilidade dolorosa, a capacidade motora, o posicionamento tatil e proprioceptivo e a capacidade de manter-se em plano inclinado. No grupo I, observaram-se deficits neurologicos moderados e transitorios, que variaram entre os animais. No grupo II, foi possivel obter um trauma padronizado, caracterizado por paraplegia bilateral e simetrica dos membros posteriores, perda de propriocepcao e da sensibilidade dolorosa de todos os animais. A utilizacao do aparelho estereotaxico desenvolvido permite reproduzir clinicamente trauma medular padronizado em ratos, de maneira simples, economica e satisfatoria, o que podera proporcionar avancos nas investigacoes terapeuticas, abrangendo doencas neurodegenerativas, como e o caso do trauma medular agudo.

Avaliação mecânica da placa de compósito de poli-hidroxibutirato e hidroxiapatita em modelos ósseos de gato

Fixation bone plates made of 70% polyhydroxybutyrate and 30% hydroxyapatite composite were mechanically evaluated. The fifteen composite plates employed presented six holes and measured 60 x 10mm, length and width, respectively, with thickness ranging from 3 to 5mm according to the region. The plates were fixed in acrylic models of cat femur, then were subjected to tests of four-points bending, axial compression, and torsion, using as reference 2mm stainless steel plates. The means of the maximum force in flexion and compression tests were, respectively, 323.20N and 617,70N for the composite plates and 352.33N and 547.70N for the steel plates. In the torsional test, the means of torque were 1.01Nm for the composite plates and 1.15Nm for steel plates. There were no statistical differences between the plates of composite and steel. The physical behavior of the material was different once the composite plates broke up while the stainless steel ones only presented deformation, revealing the low ductility of the composite plates

Efeito do produto iônico do biovidro 60S na diferenciação osteogênica de células-tronco mesenquimais do tecido adiposo de cães

The aim was to evaluate the ionic product of 60S bioglass (BV60S) in osteogenic differentiation of mesenchymal stem cells from adipose tissue (ADMSCs) in dogs. ADMSCs were differentiated without the ionic product (OST) and with the ionic product (PI-OST) for 7, 14 and 21 days. We evaluated the MTT, alkaline phosphatase (ALP), collagen mineralization and expressions of osterix (OSX), bone sialoprotein (BSP), osteonectin (ON) and osteocalcin (OC). The PI-OST group had a lower MTT conversion to 7days and higher conversion at 21 days. The ALP activity was higher in the OST group at 14 and 21 days. Collagen synthesis was higher in the OST group at 7 and 21 days. A higher mineralized area in the PI-OST group was observed at all times. There were no differences in expressions of OSX and OC between groups. We observed increased expression of BSP in the PI-OST group at 14 and 21 days. The expression of ON was higher in the OST group at 14 days. It was concluded that the ionic product of BV60S promotes in vitro osteogenesis of MSC-AD from dogs.

Aspectos clínicos, cirúrgicos e epidemiológicos da luxação de patela em cães atendidos no Hospital Veterinário, no período de janeiro de 2000 a julho de 2010: estudo retrospectivo

The epidemiological profile, clinical signs, and surgical techniques used and the recovery of dogs presented for treatment of patellar luxation in the Veterinary Hospital of UFMG in the period from 2000 to 2010 were evaluated through a retrospective study. The clinical and surgical records of dogs and the data recorded for each animal were used. 342 joints in the records of 210 animals were studied. The congenital bilateral medial luxation was the most frequent occurrence and females were more affected. The age of the animals ranged from 32 days to 16 years, with higher incidence of luxation in animals under one year of age and body mass below 9.1kg. In 11.7% of the members had grade I luxation, 39.8% were grade II, 20.5% were grade III and 28% were grade IV. The frequency of preoperative claudicating was higher in dogs with luxation grades III and IV. Of the 342 joints, 218 underwent surgery. In the postoperative evaluation of animals, those with grade IV luxation showed higher claudicating frequency. The patellar luxation mainly affects females, and the bilateral congenital luxation is the most common occurrence, and young and small animals are more likely to have it. Functional recovery postoperative luxation in grade IV is slow and partial.