Correlation of Fracture Resistance of Dental Implants and Bite Force in Dogs described in the literature: An In Vitro Study.

Dental implants are not routinely used for rehabilitation in veterinary dentistry. For some veterinarians, further studies are necessary to be considered for clinical use in animals. The objective of the present in vitro study was to evaluate static fatigue of dental implants and to correlate that with the bite strength of dogs described in the literature. Sixty implants and abutments were used with the smallest diameter of each brand of implant utilized in the study. Three groups (n = 20) were created on the basis of the implant diameter, all with external hex connector: 3.30 mm (group 1), 4.0 mm (group 2) and 5.0 mm (group 3). All groups were subjected to quasi-static loading at 30° to the implant's long axis in a universal machine (model AME-5 kN). The mean fracture strength for group 1 was 964 ± 187 N, for group 2 was 1618 ± 149 N and for group 3 was 2595 ± 161 N. Significant differences between the groups with respect to resistance after the load applications were observed (P < .05). The diameter of implants affects the resistance to external forces during the application of non-axial strength (off-axis loading) and must be considered during the planning of rehabilitation to avoid problems.

Adult stem cells in the healing of fractures and bone grafts / Células-madre adultas en la cicatrización de fracturas e injertos óseos

ABSTRACT The traumatic accidents which result in fractures and even in impairment of a bone segment have a high prevalence in routine veterinary surgery. Many times these fractures are complex and difficulty healing or need bone grafts to preserve and restore the length of the affected limb. Thus, the recovery time of these animals is usually delicate and long, with complications risks, such as delayed union and non-union of the fractured bone segments or absence of graft incorporation. In this sense, the stem cells (SC) have shown to be a strong ally of the orthopedic doctors due to their capacity to provide osteoprogenitor cells, to increase the osteoinductive effect minimize the healing time and provide a greater efficiency to the repairing process. Due to that, before the expectation of their assignments, this review aims to describe the stem cells characteristics, their current applications in the fractures healing and, especially, their contribution to the bone grafts consolidation.

RESUMEN Los accidentes traumáticos que resultan en fracturas y hasta en el comprometimiento de un segmento óseo tienen alta prevalencia en la rutina quirúrgica veterinaria. Muchas veces esas fracturas son complejas y presentan dificultades de cicatrización o necesitan de injertos óseos para preservar y restaurar el largo del miembro acometido. De esa forma, el tiempo de recuperación de esos animales suele ser delicado y prolongado con riegos de complicaciones, como unión retardada y no unión de los segmentos óseos fracturados o ausencia de incorporación de los injertos. En este sentido, las células-madre (CT) vienen demostrando ser una fuerte aliada de los ortopedistas debido a su capacidad en proveer células osteoprogenitoras, de incrementar el efecto osteoinductor, minimizar el tiempo de cicatrización y proporcionar mayor eficiencia al proceso reparador. Frente a la expectativa de sus atribuciones, la presente revisión tiene por objetivo describir las características de las células-madre, sus aplicaciones actuales en la cicatrización de fracturas y, especialmente, su contribución en la consolidación de injertos óseos.

DNA damage in dental pulp mesenchymal stem cells: An in vitro study.

The aim of this study was to evaluate the potential use of a DNA comet assay, DNA fragmentation fluorimetric assay and reactive oxygen species levels as potential biomarkers of genome conditions of dental pulp stem cells (DPSCs) isolated from dog canine teeth. Mesenchymal stem cells were isolated from the dental pulp collected from dog teeth. The results obtained suggest the ideal moment for clinical application of cellular therapy for this type of cell. The cell culture was maintained with Dulbecco's modified Eagle's medium supplemented with 10.00% fetal bovine serum for eight passages. During each passage, cell proliferation, oxidative stress and level of DNA fragmentation were assessed by3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium (MTT) assay, testing 2,7 dichlorodihydro-fluorescein-diacetate and PicoGreen®, respectively. There were important differences among the first three DPSC passages compared to passages 4-8 and a large number of nuclei with some levels of DNA damage (30.00 to 40.00% in initial DPSC passages and > 50.00% in late passages), indicating in vitro DPSC genomic fragility. Within the limitations of this study, the results suggest these relatively simple and inexpensive approaches - comet and DNA fragmentation assays - could help sort stem cells with less DNA damage for use in research or therapies.

Vascular Endothelial Growth Factor Up-regulation in Human Amniotic Fluid Stem Cell Enhances Nephroprotection After Ischemia-Reperfusion Injury in the Rat.

OBJECTIVE: To evaluate if the up-regulation of vascular endothelial growth factor strengthens the protective effect of amniotic fluid stem cells in a renal ischemia-reperfusion injury model. DESIGN: Randomized animal study. SETTINGS: University research laboratory. SUBJECTS: A total of 40 males 12-week-old Wistar rats were subjected to ischemia-reperfusion and assigned to four groups: amniotic fluid stem cells, vascular endothelial growth factor-amniotic fluid stem cells in two different doses, and vehicle. Ten animals were used as sham-controls. INTERVENTION: Six hours after induction of renal ischemia-reperfusion injury, amniotic fluid stem cells, vascular endothelial growth factor-amniotic fluid stem cells in two different doses, or vehicle were injected intraarterially. MEASUREMENTS AND MAIN RESULTS: Analyses were performed at 24 hours, 48 hours, and 2 months after treatment. Outcome measures included serum creatinine, urine microprotenuira, and immunohistomorphometric analyses. Vascular endothelial growth factor-amniotic fluid stem cells induced a significantly higher nephroprotection than amniotic fluid stem cells. This effect was mediated mainly by immunomodulation, which led to lower macrophage infiltration and higher presence of regulatory T cell after ischemia-reperfusion injury. At medium term, it inhibited the progression toward chronic kidney disease. Vascular endothelial growth factor-amniotic fluid stem cells can worsen the ischemia-reperfusion injury when delivered in a high dose. CONCLUSIONS: Up-regulation of vascular endothelial growth factor enhances the therapeutic effect of human amniotic fluid stem cells in rats with renal ischemia-reperfusion injury, mainly by mitogenic, angiogenic, and anti-inflammatory mechanisms.

Evaluation of electrosurgery and titanium clips for ovarian pedicle haemostasis in video-assisted ovariohysterectomy with two portals in bitches / Eletrocirurgia bipolar e clipes de titânio para hemostasia em pedículos ovarianos durante ovariohisterectomia videoassistida com dois portais em cadelas

ABSTRACT: This study evaluated the use of bipolar electrosurgery and laparoscopic clipping, and their effects on blood loss and the inflammatory response, during a two portal video-assisted ovariohysterectomy technique (two groups with 10 animals each). Surgical time and blood loss volume were significantly lower in the electrosurgery group. There were no significant changes in haematocrit between groups; however, haematocrit did differ between evaluated times, and decreased 10% from the initial measurement to four hours after the procedure. The inflammatory response was significantly higher throughout the post-surgical period, but without any different clinical signs between the two groups. Both techniques had good application for the two portal video-assisted procedure; however, the bipolar electrosurgery allowed for shorter surgical times, reduced blood loss and a minimal learning curve for the surgeon.

RESUMO: Este estudo avaliou a utilização da eletrocirurgia bipolar e do clipador laparoscópico em relação à perda sanguínea e resposta inflamatória durante a ovariohisterectomia videoassistida com dois portais (dois grupos com 10 animais). O tempo cirúrgico, assim como o volume de sangue perdido foram significativamente menores no Grupo Bipolar. Não houve mudanças significativas no hematócrito entre os grupos, mas entre os tempos avaliados houve redução de 10% do valor inicial até quatro horas após o procedimento. A resposta inflamatória foi significativamente maior durante todo o período de avaliação após a cirurgia, mas sem manifestações clínicas diferentes daquelas apresentadas pelo Grupo Clipador. Ambas as técnicas têm boa execução pelo procedimento videoassistido, contudo, o uso da eletrocirurgia bipolar permite tempos cirúrgicos menores, perda de sangue mínima e menor curva de aprendizado para o cirurgião.

Toxicity and oxidative stress of canine mesenchymal stromal cells from adipose tissue in different culture passages / Toxicidade e estresse oxidativo das células mesenquimais estromais do tecido adiposo de cão em diferentes passagens de cultura

Stem cells in regenerative therapy have received attention from researchers in recent decades. The culture of these cells allows studies about their behavior and metabolism. Thus, cell culture is the basis for cell therapy and tissue engineering researches. A major concern regarding the use of cultivated stem cell in human or veterinary clinical routine is the risk of carcinogenesis. Cellular activities require a balanced redox state. However, when there is an imbalance in this state, oxidative stress occurs. Oxidative stress contributes to cytotoxicity, which may result in cell death or genomic alterations, favoring the development of cancer cells. The aim of this study was to determine whether there are differences in the behavior of cultured mesenchymal stem cells from canine adipose tissue according to its site of collection (omentum and subcutaneous) evaluating the rate of proliferation, viability, level of oxidative stress and cytotoxicity over six passages. For this experiment, two samples of adipose tissue from subcutaneous and omentum where taken from a female dog corpse, 13 years old, Pitbull. The results showed greater levels of oxidative stress in the first and last passages of both groups, favoring cytotoxicity and cell death.(AU)

O uso de células-tronco como terapia regenerativa tem recebido atenção de pesquisadores nas últimas décadas. A possibilidade de cultivá-las permite o estudo de seu comportamento e metabolismo. Assim, o cultivo celular representa a base para pesquisas de terapia celular e engenharia de tecidos. Uma das principais preocupações relativa ao uso de células-tronco cultivas na rotina clínica humana ou veterinária é a reprogramação dessas células em tumores benignos ou malignos. As atividades celulares necessitam de um estado redox balanceado e quando há algum desequilíbrio nessas reações ocorre o estresse oxidativo. O quadro de estresse oxidativo contribui pra a citotoxicidade podendo resultar em morte celular e até mesmo em alterações genômicas e ocorrência de células cancerígenas. O objetivo deste trabalho foi verificar se há diferenças no comportamento de células-tronco mesenquimais estromais de tecido adiposo de cão de acordo com o seu tecido de coleta (omento e subcutâneo) avaliando o cultivo dessas células quanto a sua taxa de proliferação, viabilidade, estresse oxidativo e citotoxicidade ao longo de seis passagens. Para a execução deste experimento foram utilizadas duas amostras de tecido adiposo coletas do subcutâneo e omento do cadáver de um cão, fêmea, 13 anos de idade, da raça Pitbull. O cadáver era oriundo do Hospital Veterinário Universitário e sofreu eutanásia devido a complicações no seu quadro de cardiomiopatia. As duas amostras foram encaminhadas para o isolamento e cultura celular. Os resultados mostraram que a primeira e última passagem em ambos os grupos são as passagens mais submetidas ao estresse oxidativo ficando mais sujeitas à citotoxicidade.(AU)

Amniotic Fluid Derived Stem Cells with a Renal Progenitor Phenotype Inhibit Interstitial Fibrosis in Renal Ischemia and Reperfusion Injury in Rats.

OBJECTIVES: Mesenchymal stem cells derived from human amniotic fluid (hAFSCs) are a promising source for cellular therapy, especially for renal disorders, as a subpopulation is derived from the fetal urinary tract. The purpose of this study was to evaluate if hAFSCs with a renal progenitor phenotype demonstrate a nephroprotective effect in acute ischemia reperfusion (I/R) model and prevent late stage fibrosis. METHODS: A total of 45 male 12-wk-old Wistar rats were divided into three equal groups;: rats subjected to I/R injury and treated with Chang Medium, rats subjected to I/R injury and treated with hAFSCs and sham-operated animals. In the first part of this study, hAFSCs that highly expressed CD24, CD117, SIX2 and PAX2 were isolated and characterized. In the second part, renal I/R injury was induced in male rats and cellular treatment was performed 6 hours later via arterial injection. Functional and histological analyses were performed 24 hours, 48 hours and 2 months after treatment using serum creatinine, urine protein to creatinine ratio, inflammatory and regeneration markers and histomorphometric analysis of the kidney. Statistical analysis was performed by analysis of variance followed by the Tukey's test for multiple comparisons or by nonparametric Kruskal-Wallis followed by Dunn. Statistical significance level was defined as p <0.05. RESULTS: hAFSCs treatment resulted in significantly reduced serum creatinine level at 24 hours, less tubular necrosis, less hyaline cast formation, higher proliferation index, less inflammatory cell infiltration and less myofibroblasts at 48 h. The treated group had less fibrosis and proteinuria at 2 months after injury. CONCLUSION: hAFSCs contain a renal progenitor cell subpopulation that has a nephroprotective effect when delivered intra-arterially in rats with renal I/R injury, and reduces interstitial fibrosis on long term follow-up.

Anthocyanins suppress the secretion of proinflammatory mediators and oxidative stress, and restore ion pump activities in demyelination.

The aim of this study was to investigate the protective effect of anthocyanins (ANT) on oxidative and inflammatory parameters, as well as ion pump activities, in the pons of rats experimentally demyelinated with ethidium bromide (EB). Rats were divided in six groups: control, ANT 30 mg/kg, ANT 100 mg/kg, EB (0.1%), EB plus ANT 30 mg/kg and EB plus ANT 100 mg/kg. The EB cistern pons injection occurred on the first day. On day 7, there was a peak in the demyelination. During the 7 days, the animals were treated once per day with vehicle or ANT. It was observed that demyelination reduced Na(+),K(+)-ATPase and Ca(2+)-ATPase activities and increased 4-hydroxynonenal, malondialdehyde, protein carbonyl and NO2plus NO3 levels. In addition, a depletion of glutathione reduced level/nonprotein thiol content and a decrease in superoxide dismutase activity were also seen. The dose of 100 mg/kg showed a better dose-response to the protective effects. The demyelination did not affect the neuronal viability but did increase the inflammatory infiltrate (myeloperoxidase activity) followed by an elevation in interleukin (IL)-1ß, IL-6, tumor necrosis factor-α and interferon-γ levels. ANT promoted a reduction in cellular infiltration and proinflammatory mediators. Furthermore, ANT restored the levels of IL-10. Luxol fast blue staining confirmed the loss of myelin in the EB group and the protective effect of ANT 100 mg/kg. In conclusion, this study was the first to show that ANT are able to restore ion pump activities and protect cellular components against the inflammatory and oxidative damages induced by demyelination.

A surgical technique for homogenous renal distribution of substances in rats.

Intra-arterial injection of mesenchymal stem cells has been proven to result in a superior nephroprotection compared to intravenous injection. This avoids initial passage through filter organs such as the lung, liver and spleen. The aim of the present study was to investigate whether suprarenal aortic delivery results in a homogenous distribution to both kidneys. Chinese ink was used to evaluate the renal distribution pattern for the comparison of two retrograde intra-aortic injection methods. In the first, the aorta caudal to the renal branches was temporarily clamped and Chinese ink was injected at the level of the renal arteries. In the second, a distal aortic clamp was combined with alternated clamping of the contralateral arteries. Immediately after injection, kidneys were harvested for histological analysis. Amniotic fluid stem cells labeled with LacZ were injected in the aorta by alternated clamping of the renal arteries in order to track the cells in a rat ischemia/reperfusion model. Without renal artery clamping, intra-aortic administration resulted in a delivery of the ink into the right kidney, whereas administration with alternated clamping of the contralateral renal artery, together with distal aortic artery clamping, resulted in a more homogenous distribution of the ink in both kidneys. Moreover, LacZ-positive cells were found in both kidneys after 6 h of injection. In conclusion, the retrograde administration of Chinese ink in two steps is a fast and reproducible technique, which results in a more homogenous distribution of the stain in both kidneys than a single administration combined by only clamping the aorta.

Colopexia videoassistida com dois portais para o tratamento de prolapso retal recidivante / Two portal video-assisted colopexy for treatment of recurrent rectal prolapse

O presente relato descreve a utilização da colopexia videoassistida por meio de dois portais de acesso em um caso de cão com prolapso retal recidivante. Após abordagem laparoscópica, o cólon descendente foi tracionado em sentido caudocranial, promovendo-se a redução do prolapso. O acesso pré-púbico foi ampliado, exteriorizando-se o bordo antimesentérico do cólon, no qual se realizou incisão seromuscular de tamanho correspondente à realizada na parede muscular, criando uma ferida de aproximadamente 2,5cm de extensão. A fixação à bainha muscular interna se deu através de sutura contínua simples empregando fio de ácido poliglicólico n° 2-0. Não houve complicações no trans-operatório, bem como indícios de recidiva ou episódios de tenesmo e disquesia após seis meses da intervenção cirúrgica. A colopexia videoassistida descrita é uma alternativa à técnica convencional na correção de prolapso retal recidivante em cães.

This report describes a two portals video-assisted colopexy technique in a case of dog with recurrent rectal prolapse. After laparoscopic approach, the descending colon was pulled in a caudocranial direction to promote the prolapse reduction. The prepubic laparoscopic access was enlarged for the exteriorization of colon's antimesenteric border, which was incised in its seromuscular layer with a similar size of the muscular wall incision, creating a 2,5cm wound. The colopexy on the internal muscular sheath was performed using a simple continuous pattern with 2-0 polyglycolic acid. There were no transoperative complications, as well as evidence of recurrence or episodes of tenesmus and dyschezia for at least six months after surgery. The video-assisted colopexy described is an alternative to the conventional technique of recurrent rectal prolapse treatment in dogs.

Marcadores fluorescentes coloidais: conceitos e aplicações / Colloidal fluorescence markers: concepts and applications

Os nanocristais coloidas ou quantum dots são pontos quânticos e semicondutores na forma coloidal. Eles têm sido responsáveis por um grande volume de pesquisas, seja no âmbito da ciência básica ou aplicações em campos diversos como sonda luminescente, dentre eles a biotecnologia. O domínio das metodologias desses pontos quânticos é o primeiro e fundamental passo para futuras aplicações como biomarcadores em sistemas biológicos, in vitro e in vivo, devido a vantagens em relação aos fluoróforos orgânicos. O objetivo deste artigo é realizar uma breve revisão sobre marcadores biológicos nanocristais e sua importância nas pesquisas biológicas.

The nanocrystals are quantum dots and semiconductors in aqueous solution. They have been responsible for a large volume of research, either within the basic science and which can be applied in diverse fields such as luminescent probe, among them biotechnology. The field of these quantum dots methodologies is the first and fundamental step for future applications as biomarkers in biological systems in vitro and in vivo, due to advantages over organic fluorophores. This article aims to conduct a review of biological markers nanocrystals and their importance in biological research.

Substituição dos ligamentos cruzados cranial e caudal em cães por duplo implante de polipropileno / Replacement of the cranial and caudal cruciate ligaments in dogs by double t polypropylene implant

O objetivo deste trabalho é salientar uma alternativa eficaz no tratamento da ruptura dos ligamentos cruzados cranial e caudal de cães, sem associação de imobilização externa. Foram atendidos seis animais portadores de ruptura de ambos os ligamentos cruzados. Optou-se pela correção cirúrgica intracapsular, utilizando-se dois implantes sintéticos de polipropileno, para a estabilização da articulação. Os pacientes retornaram ao apoio completo do membro em 11,8±3,5 dias e não mantiveram instabilidade articular, após 0, 30 e 90 dias de avaliação clínica pós-operatória. Aos 90 dias após a cirurgia, não se percebeu claudicação nos pacientes avaliados. Concluiu-se que a técnica utilizada promoveu total estabilidade articular na ausência dos ligamentos cruzados cranial e caudal.

The objective of this study is to point out an effective alternative in the treatment of the cranial and caudal cruciate ligaments rupture in dogs, with no association of external immobilization. Six dogs with rupture of both cruciate ligaments were included in the present study. Stifle joint was surgically stabilized by an intracapsular technique, using two polypropylene synthetic implants. The animals returned to full member support in 11.8±3.5 days and did not sustain any joint instability degree after 0, 30 and 90 days of clinical evaluation after surgery. At 90 days after surgery, it became apparent lameness in any of the six patients. It was concluded that the technique employed caused total joint stability in the absence of caudal and cranial cruciate ligaments.

Transplante de fração total de células mononucleares ou fração vascular estromal associada à membrana celulósica em feridas cutâneas experimentais de coelhos / Total fraction of mononuclear cell or stromal vascular fraction transplant associated with cellulosic membrane in experimental cutaneous wounds in rabbits

A pele apresenta diversas funções importantes para o organismo. A manutenção de sua integridade é fundamental, entre outras, para impedir a penetração de microrganismos e a perda de líquidos essenciais à manutenção da vida. Por estar constantemente exposta ao meio ambiente, a pele é altamente susceptível a traumas que podem acarretar soluções de continuidade. A cicatrização da pele ferida deve ser rápida e diversas alternativas são buscadas, visando à redução do tempo de reparo a fim de garantir cicatriz funcional e esteticamente aceitável. Uma opção cada vez mais viável para reparar tecidos danificados é a terapia celular com células-tronco adultas. Os objetivos deste trabalho consistiram em avaliar o transplante da fração total de células mononucleares (FTCM) da medula óssea (MO) e da fração vascular estromal (FVE) do tecido adiposo (TA), associado ao uso da membrana celulósica. Para realização deste experimento, 20 coelhos foram divididos aleatoriamente em quatro grupos com cinco animais cada. Após a indução da ferida cutânea experimental, o grupo A, não recebeu nenhum tratamento, o grupo B, recebeu apenas membrana celulósica e os grupos C e D, além de receberem a membrana, foram submetidos a transplante autólogo da FTCM, com valor total de células entre 6,92 x 106 a 4,91 x 107 e uma viabilidade de 82 a 97% ou da FVE, com valor total de células entre 9,6 x 105 e 6,5 x 106 e uma viabilidade de 66 a 87%, respectivamente. Ao final do período de avaliação, os três grupos tratados apresentaram diferença estatística significativa da área da ferida em relação ao grupo controle e o grupo que recebeu a FVE do tecido adiposo apresentou o menor tempo de cicatrização da ferida.

The skin presents various important functions to the organism. The maintenance of its integrity is fundamental, among others, to prevent penetration of microorganisms and exit of liquids essential to life maintenance. Due to its constant environment exposure, the skin is highly susceptible to trauma which can result solutions of continuity. The healing of wounded skin should be fast and many alternatives are searched for, aiming to reduce repair time and to guarantee a functional and esthetically acceptable scar. One option to repair injured tissues which is ever more viable is cellular therapy with adult stem cells. The aims of this study consisted in evaluating the transplant of total mononuclear cell fraction (TMCF) from bone marrow (BM) or stromal vascular fraction (SVF) from adipose tissue (AT), associated with the use of cellulose membrane. To carry out this experiment, 20 rabbits were randomly divided in four groups with five animals each. After induction of the experimental cutaneous wound, Group A did not receive any treatment; group B received only cellulose membrane; and groups C and D, in addition to receiving the membrane, were submitted to autologous transplant of TMCF, with total cell value between 6,92 x 106 and 4,91 x 107 and a viability of 82 to 97% or SVF, with total cell value between 9,6 x 105 and 6,5 x 106 and a viability of 66 a 87%, respectively. At the end of the evaluation period, the three treated groups presented significant statistical difference of wound area in relation to the control group, and the group which received SVF from adipose tissue presented the shortest wound healing time.

Cardiopulmonary effects and eyeball centralization with low-dose atracurium in spontaneously breathing, anesthetized dogs / Avaliação cardiopulmonar e da centralização do globo ocular em cães com baixas doses de atracúrio mantidos em anestesia inalatória sob ventilação espontânea

The objective was to determine the cardiopulmonary effects and eyeball centralization time obtained with 15 or 30µg kg-1 of atracurium in anesthetized dogs under spontaneous breathing. Eighteen healthy adult mixed-breed dogs were used, which received 0.1mg kg-1 acepromazine and 0.5mg kg-1 morphine IM, followed by 4mg kg-1 propofol IV and maintained on isoflurane anesthesia with spontaneous breathing. Animals received 1mL 0.9 percent NaCl IV (CG), 15µg kg-1 (G15) or 30µg kg-1 (G30) of atracurium IV. Eyeball centralization time was measured; heart rate (HR), systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures, respiratory rate (RR), tidal volume (Vt) and minute volume (Vm) were determined every 5min, and pH, arterial CO2 pressure (PaCO2 ), arterial O2 pressure (PaO2 ), hemoglobin oxygen saturation (SaO2 ), bicarbonate (HCO3-) and base excess (BE) every 15min until 60min. Both doses of atracurium produced a similar period of eyeball centralization. Vt in groups treated with atracurium was lower than in CG up to 15min. Vm in G15 differed from CG up to 10min and in G30 up to 25min. No differences were observed for cardiovascular parameters, RR, SaO2, PaO2, HCO3- and BE. pH decreased in CG between 30 and 60min and in G15 and G30 at 15min. G30 differed from CG between 15 and 30min. PaCO2 in GC differed from baseline between 30 and 60min and in G15 differed at 15min. Atracurium at the dose of 15µg kg-1 is adequate for short corneal procedures in inhalant-anesthetized dogs under spontaneous breathing.

Objetivou-se determinar os efeitos cardiopulmonares e o tempo de centralização do globo ocular obtidos com 15 ou 30µg kg-1 de atracúrio em cães anestesiados sob ventilação espontânea. Dezoito cães adultos foram pré-medicados com 0,1mg kg-1 de acepromazina e 0,5mg kg-1 de morfina IM, anestesiados com 4mg kg-1 de propofol IV e mantidos sob anestesia inalatória com isofluorano em ventilação espontânea. Os animais receberam 1mL de NaCl 0,9 por cento IV (GC), 15µg kg-1 (G15) ou 30µg kg-1 de atracúrio IV. Mensuraram-se o tempo de centralização do globo ocular, a frequência cardíaca (FC), as pressões arteriais sistólica (PAS), média (PAM) e diastólica (PAD), a frequência respiratória (f), o volume corrente (Vt) e o volume minuto (Vm) a cada 5min, e o pH, as pressões arteriais de CO2 (PaCO2) e O2 (PaO2), a saturação de oxigênio nas hemoglobinas (SaO2), o bicarbonato (HCO3-) e o excesso de base (BE) a cada 15min, até 60min. Ambas as doses de atracúrio produziram similar período de centralização. Os grupos tratados com atracúrio apresentaram menores valores para Vt até 15min. O Vm, no G15, diferiu do GC até 10min e do G30 até 25min. Não foram observadas alterações nos parâmetros cardiovasculares f, SaO2, PaO2, HCO3- e EB. O pH diminuiu no GC entre 30 e 60min e em G15 e G30 aos 15min. A PaCO2 elevou-se no GC entre 30 e 60min e no G15 aos 15min. A dose de 15µg kg-1 de atracúrio demonstrou ser adequada para centralização do globo ocular, podendo ser utilizada em procedimentos corneanos de curta duração em cães anestesiados com isoflurano e mantidos sob ventilação espontânea.

Hemipelvectomia no tratamento de condrossarcoma no acetábulo de cão / Hemipelvectomy in the treatment of chondrosarcoma of the acetabulum dog

Hemipelvectomia é a remoção de parte da pelve e tem sido indicada no tratamento cirúrgico de tumores malignos. Este estudo apresenta o caso de um paciente canino, portador de condrossarcoma recidivante, submetido à hemipelvectomia parcial com amputação do membro. O objetivo deste trabalho é ressaltar a importância da cirurgia radical no tratamento de condrossarcoma ósseo, abordando uma alternativa viável e pouco convencional para pacientes acometidos por tumores na pelve, que frente à extensão da lesão podem ser erroneamente diagnosticados como portadores de neoplasias não tratáveis. Após a realização da hemipelvectomia parcial com amputação do membro, o animal obteve retorno satisfatório à deambulação, sem dificuldade de apoio ou alteração de equilíbrio.

Hemipelvectomy is the removal of part of the pelvis and is indicated for the surgical treatment of malignant tumors. This study presents the case of a canine patient with recurrent chondrosarcoma, submitted to hemipelvectomy with limb amputation. The report aims to highlight the importance of surgery in the treatment of radial bone chondrosarcoma, addressing a viable and unconventional alternative for patients suffering from tumors in the pelvis, which against the extension of the lesion may be misdiagnosed as intractable cancer. After the partial hemipelvectomy with amputation of the limb the animal satisfactory returned to ambulation without difficulty in supporting or alteration in balance.

Miniplacas de titânio na redução de fraturas mandibulares em cães e gatos: estudo de seis casos / Titanium miniplates in mandibular fracture repair in dogs and cats: study of 6 cases

Fraturas de mandíbula e maxila são comuns em cães e gatos, correspondendo a cerca de 3 a 6 por cento de todas as fraturas. Muitos tratamentos são propostos para a correção desse defeito, como o uso de pino intramedular, a fixação esquelética externa, a cerclagem e o uso de acrílicos e placas ósseas. Este estudo teve como objetivo avaliar o uso das mini e microplacas de titânio do sistema 2,0 e 1,5mm no tratamento de fraturas mandibulares, em cães e gatos, respectivamente. Os parafusos e as miniplacas utilizadas são compostos de titânio, e o formato dependeu da localização e do tipo de fratura. No total, foram avaliados seis casos, dos quais quatro apresentaram completa consolidação, sendo as placas utilizadas como método único ou associado com fio de aço ou imobilização com focinheira. As causas de insucesso foram a quebra da placa em um dos casos e a contaminação do enxerto, com posterior osteomielite em decorrência da deiscência dos pontos em outro caso. O emprego das miniplacas de titânio mostrou-se eficaz na maioria dos casos testados, promovendo fixação rígida e retorno funcional adequado, sendo utilizado como método único ou associado com outras técnicas de osteossíntese.

Jaw and maxilla fractures are common in dogs and cats, representing 3-6 percent of all fractures. Numerous techniques are proposed to reduce the defect such as intramedullary pin, percutaneous skeletal fixation, circumferential wiring, acrylic splints and bone plating. This study aimed to evaluate the use of 2.0mm and 1.5mm titanium microplates in the treatment of mandibular fractures in dogs and cats, respectively. The screws and the mini and microplates used were composed of titanium and their format depended on the location and type of fracture. A total of 6 cases were selected and 4 of them had complete consolidation using the mini microplate method alone or associated with steel wire or tie with noseband. In one case the failure occurred due to plate breakage and other implant failed due to dehiscence of the skin suture. The use of mini titanium microplates was effective in most cases, as a single method or combined with other techniques of osteosynthesis, because it promoted rigid fixation and return to the appropriate function.

Overlapping of mononuclear cells derived from bone marrow in rats' intervertebral discs: an in vitro study / Sobreposição de células mononucleares provenientes da medula óssea em disco intervertebral de ratos: estudo in vitro

In this study, bone marrow mononuclear cells (BM-MNC) derived from rats were used in order to promote intervertebral disc regeneration. These cells were isolated after centrifugation in a Ficoll-Paque™ PLUS density gradient and then placed in plastic dishes to proliferate during a period of 14 days. The BM-MNCs were previously labeled with the fluorescent membrane marker Chloromethyl-benzamidodialkylcarbocyanine (CM-DIL), and thereafter were implanted in rats' intervertebral discs explants as an in vitro experimental model. Daily analyses of the cells under a fluorescence microscope revealed morphological changes, which assumed a thin and elongated shape similar to cells that originally form the annulus fibroses. Histopathological analysis demonstrated the presence of mononuclear cells interspersed within collagen fibers. The presence of viable cells, in which were found morphological changes and their disposal in the same pattern of the layers that originate the annulus fibrosus, is an indicator that they engrafted and proliferated on the intervertebral disc. Therefore, morphological changes presented by these cells indicate that they presented mesenchymal stem-like cell characteristics.

Neste trabalho, foram utilizadas células mononucleares provenientes da medula óssea (MO) de ratos para implantação em discos intervertebrais, a fim de estudar a sua participação em possível regeneração tecidual. Essas células foram obtidas por centrifugação, em gradiente de Ficoll-Paque™ PLUS, e cultivadas em frascos apropriados, por um período de 14 dias. Em etapa posterior, foram submetidas à marcação celular, em que foi utilizado o marcador citoplasmático CM-Dil, seguida de implantação em discos intervertebrais de ratos, em um sistema de cultivo in vitro. Foram feitas avaliações diárias dos discos com utilização de um microscópio de fluorescência, sendo constatadas alterações morfológicas com um formato alongado semelhante a células que originalmente compõem o anel fibroso. O exame histopatológico revelou a presença de células mononucleares entremeadas em fibras de colágeno. As alterações morfológicas das células e a presença de células viáveis são indícios de que essas células se integraram e proliferaram no disco intervertebral, interagindo com o microambiente deste, assumindo inclusive características semelhantes às apresentadas por células-tronco mesenquimais.

Técnicas e sítios de coleta de medula óssea em cães e gatos / Techniques and bone marrow sites sampling in dogs and cats

Atualmente, o incremento das pesquisas enfoca a medula óssea como fonte potencial para o tratamento de doenças, uma vez que seu uso como diagnóstico já é largamente empregado. Os objetivos deste artigo são revisar os melhores acessos à medula óssea e destacar a importância desse material como diagnóstico e tratamento de doenças. São abordadas particularidades sobre as técnicas de coleta e as complicações observadas pelos autores, a fim de facilitar os procedimentos, tornando-os mais seguros.

Currently, the research focuses on bone marrow as a potential source for the treatment of diseases, since its use as a diagnosis is already largely employed. This paper aims to promote a practical review on the best access to the bone marrow and the importance of this material as diagnosis and treatment. Sampling techniques are observed and detailed by the authors, in order to facilitate the procedures and make them safer.

Transplante autólogo de células mononucleares da medula óssea em úlcera de córnea experimental em cães / Bone marrow mononuclear cells autotransplant in experimental corneal ulcer in dogs

As células mononucleares (CM) da medula óssea (MO) despertam grande interesse nas pesquisas sobre regeneração tecidual. O limbo é a fonte de células-tronco (CT) para repor ceratócitos lesados e uma disfunção destas é denominada deficiência límbica. Essa condição é desenvolvida por diversas afecções, sendo que a queimadura por base é a mais comum. A fim de confirmar a presença das CM da MO transplantadas, a ocorrência de quimiotaxia destas e comparar histopatologicamente os grupos tratado e controle, utilizou-se um modelo experimental de úlcera de córnea associado ao autotransplante de CM. Para tanto, 16 cães machos ou fêmeas, sem raça definida, foram submetidos à úlcera experimental de córnea com papel filtro embebido em hidróxido de sódio (NaOH). Após as lesões, os animais foram submetidos a transplante subconjuntival de CM da MO, previamente marcadas com nanocristais. A avaliação pós-operatória foi realizada por imunofluorescência no sexto dia após o transplante e por histopatologia passados 15 dias do procedimento, quando foi possível notar que as CM fixaram-se na região lesionada, não sofreram quimiotaxia e, apesar de diminuírem a inflamação, não auxiliaram o processo de cicatrização corneana a curto prazo. Assim, sugerem-se estudos adicionais no transplante de CM da MO na cicatrização da córnea.

Bone marrow (BM) mononuclear cells (MC) are a great subject in tissual regeneration. The main stem cell source to the eye is the limbus. Theses cells replace injured corneal cells, however, if the limbal stem cells are not functional, a limbal deficiency with concomitant conjunctivalization takes place. This pathological condition can be caused for several reasons, in which alkali burns are the most common. To conduct a research about transplanted BM MC presence, the cells homing and to histopathologically compare the treated and sham group, an experimental corneal ulcer model associated with MC autotransplant was used. Sixteen, male or female, stray dogs suffered experimental corneal ulceration with sodium hydroxide soaked filter discs. After the lesions, animals were submitted to subconjunctival autotransplant of previously marked BM MC. The evaluation was made by immunofluorescence on the sixth day after lesions creation and histopathology was conducted 15 days after the same procedure, when it was possible to observe that the MC grafted in the injured area, the cells did not execute the homing process and, despite the inflammatory decrease, they did not help the corneal epithelial healing process in a short term evaluation. Thus, future studies about MC transplantations in corneal ulcers are indicated.

Colheita de medula óssea em cães: modelo para obtenção da fração total de células mononucleares / Bone marrow harvest in dogs: model for acquisition of the total fraction of mononuclears cells

No presente trabalho foi elaborada uma técnica para protocolo de colheita de medula óssea (MO) (10ml. kg-1), do osso femoral, para isolamento, quantificação e viabilidade da fração total de células mononucleares (CM). Para tanto, 40 cães machos ou fêmeas, sem raça definida, com idade aproximada de dois anos, pesando em torno de 10kg, foram submetidos a procedimento asséptico em ambiente cirúrgico para colheita de MO. Para a obtenção de uma quantidade suficiente de CM, durante o procedimento foi utilizada a agulha tipo Steis anatômica, que favoreceu a colheita de volume sangüíneo em menor espaço de tempo e não danificou a viabilidade celular. Também foi utilizado o Kit Bone Marrow collection, que teve a finalidade de filtrar as espículas ósseas, mantendo a integridade das CM colhidas durante o período decorrido para o acondiconamento do sangue. Durante o período da colheita de MO, os animais foram submetidos à collheita de sangue periférico (pré, trans e pós-operatório) para avaliações hematológicas e sofreram autotransfusão sangüínea para suprir a queda acentuada de hemoglobina ocorrida nos primeiros momentos da coletaheita. O total de MO colhida e filtrada foi colocado lentamente sob gradiente de densidade Histopaque (1.077g ml-1). O material foi centrifugado a 440 x g por 30 minutos e o anel de células foi colhido, lavado e centrifugado três vezes em meio contendo solução salina 0,9 por cento, DMEM e soro sangüíneo autólogo estéril. Foi realizada a contagem do anel celular em câmara de Neubauer e foi verificada sua viabilidade utilizando corante vital. Neste estudo foi verificado que no volume de MO colhido foi possível obter a média de 2,57 x 10(6) (± 1,56) CM kg-1 e a viabilidade celular foi superior a 90 por cento (96,72 ± 2,9 por cento). Conclui-se que a técnica de colheita de MO com agulha Steis com lavagem celular no meio contendo soro autólogo e Kit Bone Marrow e agulha Steis com lavagem celular no meio contendo...

In the present research a new protocol to harvest 10ml kg-1 femoral bone marrow (BM) was developed to allow isolation, quantification and to test the mononuclear cell (MC) fraction viability. Forty male or female stray dogs, aging and weighting around two years old and 10kg respectively, were submitted to aseptic bone marrow harvest in a surgical environment. To achieve an ideal cell count of MC, an anatomical Steis needle was used during the procedure, which favored the indicated volume harvest in a shorter period of time without interfering cellular viability. A bone marrow collection kit was also used to filter bone fragments while maintaining harvested MC integrity during blood packaging. Meanwhile BM harvesting was conducted, animals peripheral blood collection was performed (pre, trans and post-operatory) to hematological evaluations and autologous blood transfusion was made to overcome the increased hemoglobin fall that takes place in the initial harvesting moments. The harvested and filtered BM was slowly placed over a Histopaque density gradient (1.077g ml-1). The material was centrifuged at 440g x for 30 minutes. The cellular ring was harvested, washed and three times centrifuged in saline 0.9 percent, DMEM and autologous sterile serum. Cellular ring count was conducted in neubauer chamber and its viability was performed with vital dye. In this study was possible to notice that with the harvested BM volume an average of 2.57 x 10(6) (± 1.56) MC kg-1 was obtained and the cell viability was over 90 percent (96.72 ± 2.9 percent). It was concluded that the bone marrow kit and Steis needle with autologous serum cellular wash BM harvesting technique allow an ideal MC number isolation which can be administered in tissue lesions to enhance the regeneration process.