Cloves (Syzygium aromaticum) fluid gel on healing of pododermatitis in rabbits.

Wounds are damaging to quality life of confined animals, causing dysfunction in spinal, members injuries, and reduction in productive performance. This research investigated the clove antimicrobial and antioxidant activity on the healing of decubitus wounds (pododermatitis) of rabbits (Oryctolagus cuniculus). Adult animals were treated for 21 days every three days with a fluid gel spray in the wound region: control fluid gel without addition of clove (FGC0), fluid gel with addition of 1% clove powder (FGC1), and fluid gel with 2% clove powder (FGC2). Microbiological analysis for Escherichia coli and Pseudomonas spp. were performed during 21 days of experimental period. After this period, samples from treated skin were evaluated for histological analysis and evaluation of the healing process by spectroscopy (FTIR-ATR). Rabbits treated with FGC2 showed advanced healing and decreased tissue inflammation similar to healthy rabbits, while FGC0 rabbits showed a decrease in bacterial contamination without signs of healing. Both FGC1 and FGC2 rabbits demonstrated antimicrobial and antioxidant action against both bacteria tested, favoring the wound healing process. Considering the results, the use of fluid gel with 2% of clove powder (Syzigium aromaticum) based on the best antimicrobial, antioxidant and anti-inflammatory activities on healing of decubitus wounds (pododermatitis) of rabbits in commercial farming system.

Região metafisária da tíbia de coelhos: uma opção para estudos dos substitutos ósseos / Metaphyseal region of the tibia of rabbits: an option for bone substitutes studies

Apresenta-se um modelo experimental de ostectomia de tíbia em coelhos para estudo de biomateriais em processos de reparação óssea. Foi realizada falha segmentar de 6mm de diâmetro na região metafisária medial proximal de tíbia de 72 coelhos as quais foram preenchidas com substituto ósseo e avaliadas clinicamente, por exame radiográfico e por meio de tomografia computadorizada feixe cônico, em diferentes tempos. Conclui-se que a metáfise medial proximal de tíbia de coelhos é adequada como modelo para estudos que avaliem o comportamento de enxertos e/ou biomateriais em falhas ósseas.

Is presented an experimental model of tibial ostectomy in rabbits to study biomaterials during bone repair process. Segmental failure of 6 mm diameter was performed in the medial proximal tibial metaphyseal region of 72 rabbits, which were filled with bone substitute and evaluated by clinical exam, X-ray, and cone beam computed tomography at different times. It is concluded that the medial proximal tibial metaphysis region of rabbits is suitable as a model for studies that evaluate the behavior of grafts and/or biomaterials on bone defects.

Experimental Basis for Creating an Osseointegrated Neural Interface for Prosthetic Control: A Pilot Study in Rabbits.

INTRODUCTION: While debate persists over how to best prevent or treat amputation neuromas, the more pressing question of how to best marry residual nerves to state-of-the-art robotic prostheses for naturalistic control of a replacement limb has come to the fore. One potential solution involves the transposition of terminal nerve ends into the medullary canal of long bones, creating the neural interface within the bone. Nerve transposition into bone is a long-practiced, clinically relevant treatment for painful neuromas. Despite neuropathic pain relief, the physiological capacity of transposed nerves to conduct motor and sensory signals required for prosthesis control remains unknown. This pilot study addresses the hypotheses that (1) bone provides stability to transposed nerves and (2) nerves transposed into bone remain physiologically active, as they relate to the creation of an osseointegrated neural interface. METHODS: New Zealand white rabbits received transfemoral amputation, with the sciatic nerve transposed into the femur. RESULTS: Morphological examination demonstrates that nerves remain stable within the medullary canal, while compound nerve action potentials evoked by electrical stimulation of the residual nerve within the bone could be achieved at 12 weeks (p < 0.0005). CONCLUSION: Transposed nerves retain a degree of physiological function suitable for creating an osseointegrated neural interface.

A rabbit model for assessing symblepharon after alkali burn of the superior conjunctival sac.

Symblepharon due to chemical burns affects ocular surface health, and there are currently no satisfactory treatments. To improve our understanding of symblepharon, an appropriate animal model is urgently needed. We established a rabbit model of superior conjunctival sac alkaline burn to evaluate symblepharon severity. Alkali burns were induced in rabbits by contacting the superior conjunctival sac with 2 N NaOH-soaked semicircle filter paper (10 mm diameter) for 60 s, 90 s or 120 s. Clinical and histological features were examined, symblepharon severity was evaluated via conjunctival sac depth (grade I - IV) and volume measurements (grade a-d) post-injury at 4 weeks. With increasing alkali burn duration, corneal perforation and symblepharon severity increased. The 60 s group manifested a sub-conjunctiva scar. The 90 s group featured localized adhesion. The 120 s group was characterized by extensive scar hyperplasia and adhesion. The rabbit model exhibited stable and reliable symblepharon following an alkali burn of the superior conjunctival sac. For further research, 90 s is a suitable duration for conjunctival sac burn. The volume measured using conjunctival sac casting was considered when developing a successful evaluation system for symblepharon severity.

Establishment of an experimental model of small intestinal ischemia and reperfusion injuries in New Zealand rabbits / Estabelecimento de modelo experimental de indução da lesão de isquemia e reperfusão de intestino delgado em coelhos Nova Zelândia

The present study aimed to establish a methodology capable to cause intestinal ischemia and reperfusion injuries, to perform clamping of the jejunal segment of the extramural peri-intestinal marginal artery branch. For this, 37, 10-week-old male New Zealand breed rabbits were used. One rabbit was used to establish the anatomic references for the procedure and was not part of the six experimental groups; the rest were allocated into six experimental groups: Sham group, negative control, subjected only to midline celiotomy; group I1H undergoing vascular occlusion for an hour; group I2H submitted to vascular occlusion for two hours; group I1H/R2H undergoing vascular occlusion for one hour followed by two hours of reperfusion; group I2H/R1H undergoing vascular occlusion for two hours, followed by reperfusion for one hour, and group I2H/R5H undergoing vascular occlusion for two hours followed by reperfusion for five hours. The rabbits were evaluated for the macroscopic aspects (color and peristalsis) of the jejunal segment, as well as the histological aspect, checking for presence or absence of mucosal destruction, edema, hemorrhaging, lymphatic vessel dilatation, and the presence of polymorphonuclear cells. It was observed that the macroscopic and histopathological lesions accentuated in larger employed ischemia and reperfusion times. Rabbits subjected to ischemia for two hours followed by reperfusion for five hours (I2H/R5H) made up the experimental group which was easily reproducible and showed moderate intestinal injury, different from the other groups.(AU)

O presente estudo objetivou estabelecer uma metodologia capaz de causar lesões de isquemia e reperfusão intestinal, realizando clipagem de um ramo de artéria marginal peri-intestinal extramural em segmento jejunal. Para tal foram utilizados 37 coelhos da raça Nova Zelândia, machos, de 10 semanas de idade, alocados em seis grupos experimentais: grupo Sham, controle negativo, submetido apenas a celiotomia mediana; grupo I1H submetido à oclusão vascular por uma hora; grupo I2H submetido a oclusão vascular por duas horas; grupo I1H/R2H submetido a oclusão vascular por uma hora, seguida de reperfusão por duas horas; grupo I2H/R1H submetido a oclusão vascular por duas horas, seguida de reperfusão por uma hora e grupo I2H/R5H submetido a oclusão vascular por duas horas seguida de reperfusão por cincos horas. Os animais foram avaliados quanto o aspecto macroscópico (coloração e peristaltismo) do segmento jejunal e quanto ao aspecto histopatológico, verificando presença ou ausência de destruição de mucosa, edema, hemorragia, dilatação de vasos linfáticos e presença de polimorfonucleares. Observou-se que as lesões macroscópicas e histopatológicas se acentuaram nos maiores tempos de isquemia e reperfusão empregados. Os animais submetidos à isquemia durante duas horas, seguida de reperfusão por cinco horas (I2H/R5H) compuseram o grupo experimental de fácil reprodução e foram os que apresentaram uma lesão intestinal moderada, diferentes dos demais grupos.(AU)

Allogenic mesenchymal stem cell intravenous infusion in reparation of mild intestinal ischemia/reperfusion injury in New Zealand rabbits / Infusão intravenosa de células tronco mesenquimais alógenas na reparação da lesão branda de isquemia/reperfusão intestinal em coelhos Nova Zelândia

The present study aimed to evaluate the efficacy of mesenchymal stem cell (MSC) infusion, derived from adipose tissue, on reduction of local and remote tissue damage caused by the event of experimental intestinal I/R in New Zealand breed rabbits. For obtaining, characterization, and cultivation of MSC derived from adipose tissue (MSC-Adp), 3 juvenile animals (four months old) were used. The cells were considered to be viable for therapy after the fourth passage (in vitro phase). For the in vivo stage, 24 young adult animals (six months old) were used, weighing approximately 3.5 kg, in which were randomly divided into two groups, called: IR treated with MSC (I2H/R5H MSC 3D; I2H/R5H MSC 7D); IR treated with PBS (I2H/R5H PBS 3D; I2H/R5H PBS 7D). The animals were anesthetized and submitted to pre-retro-umbilical midline celiotomy. The extramural peri-intestinal marginal artery was located and clamped (predetermined and standardized region) with the aid of a vascular clip, promoting a 2 hour blood flow interruption. After this period, blood flow was reestablished, inhalatory anesthesia was suspended, and the animals awaken. After 5 hours of reperfusion, the treatments were performed by intravenous infusion according to the experimental groups. The animals were evaluated 72 hours and seven days after the treatment as for the macroscopic appearance (color and peristaltism) of the jejunal segment, and by histological evaluation of the ischemic segment for the presence or absence of destruction of the intestinal mucosa, edema, bleeding, dilation of lymph vessels, and presence of polymorphonuclear inflammatory cells, both in the mucosa and submucosa. The observed results revealed that the groups treated with MSC-Adp obtained smaller mucosal and submucosal lesions when compared to the groups treated with PBS. Also, MSC-Adp treated groups obtained controlled inflammatory response and higher mitotic rate, outcomes related to the therapeutic potential of MSC. Infusion of stem cells attenuated the lesions caused by intestinal I/R in both MSC groups when compared to the group treated with PBS.(AU)

O presente estudo teve como principal objetivo avaliar a eficácia da infusão células tronco mesenquimais (CTM) derivada de tecido adiposo sobre diminuição das lesões teciduais locais e remotas, causadas pelo evento de I/R intestinal experimental, em coelhos da raça Nova Zelândia. Para obtenção, cultivo e caracterização das CTM provenientes de tecido adiposo (ADCTM) foram utilizados 3 animais jovens. As células foram consideradas viáveis para terapia a partir da quarta passagem (fase in vitro). Para etapa in vivo foram utilizados 24 animais, adulto-jovens, pesando aproximadamente 3,5kg, divididos aleatoriamente em dois grupos experimentais, denominados IR Tratado com CTM (I2H/R5H CTM 3D; I2H/R5H CTM 7D); IR Tratado PBS (I2H/R5H PBS 3D; I2H/R5H PBS 7D). Os animais foram anestesiados e submetidos à celiotomia mediana pré-retroumbilical. A artéria marginal peri-intestinal extramural foi localizada e clampeada (região predeterminada e padronizada) com auxílio de um clipe vascular, promovendo uma interrupção do fluxo sanguíneo durante 2 horas. Após esse período, o fluxo sanguíneo foi restabelecido, a anestesia inalatória suspendida e os animais despertados. Após 5 horas de reperfusão realizou-se os tratamentos por infusão endovenosa, conforme grupos experimentais. Os animais foram avaliados 72 horas e sete dias após o tratamento quanto ao aspecto macroscópico (coloração e peristaltismo) do segmento jejunal e por meio de avaliação histológica do segmento isquemiado quanto à presença ou ausência de destruição de mucosa intestinal, edema, hemorragia, dilatação de vasos linfáticos e presença de células inflamatórias polimorfornucleares, tanto em mucosa quanto submucosa. Os resultados observados revelaram que os grupos tratados com ADCTM obtiveram menores lesões em mucosa e submucosa quando comprados aos grupos tratados com PBS. Ainda os grupos tratados com ADCTM obtiveram resposta inflamatória controlada e maior taxa mitótica, resultados relacionados ao potencial terapêutico das CTM.(AU)

Outcome of limb fracture repair in rabbits: 139 cases (2007-2015).

OBJECTIVE To evaluate outcome of limb fracture repair in rabbits. DESIGN Retrospective case series. ANIMALS 139 client-owned rabbits with limb fractures treated between 2007 and 2015. PROCEDURES Medical records were reviewed for information on fracture location, fracture treatment, and time to fracture healing. RESULTS 25 rabbits had fractures involving the distal aspects of the limbs (ie, metacarpal or metatarsal bones, phalanges, and calcaneus or talus). Fractures were treated in 23 of these 25 rabbits (external coaptation, n = 17; external skeletal fixation, 4; and intramedullary pinning, 2) and healed in all 23, with a median healing time of 28 days (range, 20 to 45 days). One hundred ten rabbits had long bone fractures, and fractures were treated in 100 of the 110 (external skeletal fixation, n = 89; bone plating, 1; intramedullary pinning, 3; and external coaptation, 7). The percentage of fractures that healed was significantly lower for open (14/18) than for closed (26/26) tibial fractures and was significantly lower for femoral (19/26) and treated humeral (4/6) fractures than for radial (23/24) or closed tibial (26/26) fractures. Micro-CT was used to assess fracture realignment during external skeletal fixator application and to evaluate fracture healing. CONCLUSIONS AND CLINICAL RELEVANCE The prognosis for rabbits with limb fractures was good, with fractures healing in most rabbits following fracture repair (109/123). Micro-CT was useful in assessing fracture realignment and evaluating fracture healing.

Biocerâmica de fosfato de cálcio nanoestruturada micro-macroporosa em grânulos de absorção rápida no preenchimento de defeito crítico em rádio de coelhos (Oryctolagus cuniculus) / Bioceramics of calcium phosphate nano-structured micro-macro porous granules rapidly absorbed in filling critical radial defect in rabbits (Oryctolagus cuniculus)

O objetivo do presente trabalho foi avaliar, por radiografia, histologia e densitometria óssea, o efeito da HA/ßTCP em grânulos de absorção rápida em defeito ósseo crítico em rádio de coelhos. Foram utilizados 35 coelhos machos, da raça Nova Zelândia, e realizou-se um defeito crítico nos rádios direito e esquerdo. Os animais foram distribuídos em GI, enxerto autólogo e GII, HA/ßTCP em grânulos de absorção rápida. Avaliações radiográficas foram feitas antes da cirurgia, após, aos oito, 15, 30, 45 e 60 dias e avaliações histológicas e de densitometria. Verificou-se diferença significativa ao se comparar a densidade mineral óssea obtida ao longo do tempo de estudo. Observou-se formação de rede vascular entre os poros da biocerâmica desde o primeiro tempo de avaliação, (oito dias). Foram observados tecido ósseo primário e trabéculas em tecido ósseo preexistente a partir de 30 dias da implantação. Aos 60 dias, constatou-se presença de matriz óssea em segmentos ósseos preexistentes, caracterizando a formação óssea centrípeta. A biocerâmica HA/ßTCP nanoestruturada micro-macroporosa em grânulos de absorção rápida não causa alterações microscópicas indicativas de rejeição, permite a invasão e a multiplicação celular, bem como propicia a regeneração óssea, constituindo um implante apropriado para preenchimento de falhas ósseas críticas.(AU)

The objective of this study was to evaluate the effect of HA/ ßTCP on rapid absorption granules in rabbit radiography, histology, and bone densitometry. Thirty - five male rabbits of the New Zealand breed were used and a critical defect was performed on the right and left radios. The animals were distributed in GI, autologous graft and GII HA / ßTCP in rapidly absorbed granules. Radiographic, histological, and densitometry evaluations were performed before surgery, then after eight, 15, 30, 45 and 60 days. A significant difference was found when comparing the bone mineral density obtained over the study time. Formation of vascular network between the bioceramic pores was observed by the first evaluation time, (eight days). Primary bone tissue and trabeculae were observed from preexisting bone tissue after 30 days of implantation. At 60 days, the presence of bone matrix was observed from the preexisting bone segments, characterizing the centripetal bone formation. The micro-macroporous nanocomposite HA / ßTCP of rapidly absorbing granules do not cause microscopic changes indicative of rejection, allows invasion, cell multiplication, and promotes bone regeneration, constituting an appropriate implant for filling of critical bone failures.(AU)

Plasma rico em plaquetas autólogas na cicatrização do tendão do músculo gastrocnêmio de coelhos / Plasma platelet-rich autogenous healing tendon of the gastrocnemius muscle in rabbits

As lesões tendíneas podem envolver a secção parcial ou total do tendão calcâneo comum e ocasionar alterações posturais do membro locomotor. O presente trabalho avaliou o efeito da aplicação tópica de concentrado de plaquetas autólogas na reparação do tendão do músculo gastrocnêmio de coelhos, decorridos 45 e 90 dias de período pós-operatório (PO). Doze coelhos adultos foram separados em dois grupos (n = 6) e submetidos à punção cardíaca e colheita de 10 mL de sangue para obtenção do plasma rico em plaquetas (PRP). Nos animais de ambos os grupos, foi realizada a tenotomia transversal total no terço médio do ventre lateral do tendão do músculo gastrocnêmio e a sua aproximação com a sutura de Kessler modificada e fio de náilon. Nos animais do grupo tratado, foi aplicado sobre a síntese dos tendões em média 490.644 mil plaquetas/μL do PRP e notou-se maior quantidade de fibras colágenas em relação ao controle, sendo que aos 90 dias de PO a intensidade de colágeno observado foi maior que nos animais com 45 dias, com maior quantidade de fibroblastos nos controles em relação aos tratados. A administração de concentrado de plasma de plaquetas autógenas no reparo do tendão gastrocnêmio de coelhos estimula e organiza o processo de reparação e ocasiona produção precoce de fibras colágenas.

Tendon lesions may involve the partial or total section of the common calcaneal tendon and cause postural changes of the member. This study evaluated, after 45 and 90 postoperative days (PO), the repair of the tendon of gastrocnemius muscle of rabbits with topical application of autologous platelet concentrate. Twelve adult rabbits were divided into two groups (n = 6) undergoing cardiac puncture and collection of 10 ml of blood to obtain platelet rich-plasma (PRP). Animals of both groups had a transverse tenotomy in the middle third of the lateral belly of the gastrocnemius tendon and muscle that was approximated with modified Kessler suture and nylon thread. In the animals of the treated group it was applied the average of 490.644 platelets / uL of PRP, per animal over the tendon synthesis. The treated group showed a higher amount of collagen fibers than the control one, and at 90 PO days the intensity of collagen was higher than at 45 days with more fibroblasts in the control than in treated one. The administration of plasma autogenous platelet concentrate in the repair of the gastrocnemius tendon of rabbits stimulates and organizes the repair process and causes early production of collagen fibers.

Utilização do filme de quitosana na reparação de tendão em coelhos / Use of the film of chitosan in the repair of tendons in rabbits

Com este trabalho objetivou-se avaliar o processo de cicatrização do tendão em coelhos, utilizando-se no grupo tratamento o filme de quitosana, por meio de uma análise clínico-cirúrgica e histológica. Foram utilizados 12 coelhos adultos, separados em grupo controle (GC) e grupo tratamento (GT), nos quais se realizou uma secção parcial do tendão gastrocnêmio de ambos os membros pélvicos. A avaliação clínica baseou-se na presença de reação inflamatória, infecção, dor e deiscência da sutura. Para a avaliação histológica, foi realizado um estudo comparativo do processo cicatricial por meio do tipo de células, da quantidade de tecido conjuntivo e da organização das fibras colágenas entre os grupos e os momentos. Nas feridas cirúrgicas, não foram observadas secreção, dor ou deiscência. Na histologia comparativa entre os grupos, o GC apresentou melhor processo cicatricial em relação ao GT, aos 60 dias. Aos 90 dias, no GT a cicatrização já esboça recuperação do tendão, com reorganização da celularidade e das fibras colágenas no tecido conjuntivo denso modelado. Concluiu-se que a quitosana estimula rápido crescimento celular, mas de forma desorganizada, e que a cicatrização completa só ocorre após 90 dias da sua implantação no tecido...

This work aimed to evaluate the process of tendon healing in rabbits, using the treatment group in chitosan film through a clinical, surgical and histological analysis. In the experiment, 12 adult rabbits were used, divided into control group (CG) and treatment group (TG), which were held in the partial section of the gastrocnemius tendon of both limbs. Clinical assessment was based on the presence of inflammation, infection, pain and suture dehiscence. For histological evaluation a comparative study of the healing process through the cell type, amount of connective tissue and collagen fiber organization was performed between groups and times. In surgical wounds no secretion, pain or dehiscence were observed. In the comparative histology between groups, the CG showed better healing compared to TG, at 60 days. On day 90 the TG already outlines tendon recovery with reorganization of cellularity and collagen fibers in the dense connective tissue modeled. It was concluded that chitosan stimulates faster cell growth, but it is haphazardly, and that complete healing occurs after 90 days of their implantation in tissue...

Aspecto radiológico e macroscópico de matriz óssea mineralizada heteróloga fragmentada e polimetilmetacrilato autoclavados em falha óssea de tíbia de coelho / Radiological and macroscopic aspects of autoclaved heterologous fragmented mineralized bone matrix and polymethylmethacrylate in bone defect in tibia of rabbits

Foi realizada falha segmentar com 6mm de diâmetro na região metafisária medial de tíbias de 12 coelhos, onde foi implantado uma associação de micro e macrofragmentos de matriz óssea cortical heteróloga fragmentada conservada em glicerina (98%) e polimetilmetacrilato autoclavados, para a sua reconstrução, e avaliados radiológica e macroscopicamente aos 30, 60, 90 e 120 dias. Houve adesão, em relação ao tempo, dos micro e macrocompósitos ao leito receptor, em 100% dos casos, mostrando ser biologicamente biocompatível, pois promoveram a reparação de falhas ósseas, sem sinais de infecção, migração e/ou rejeição, podendo, dessa forma, ser mais uma opção como substituto para preencher grandes defeitos ósseos.

A segmental defect of 6mm diameter was performed in the medial metaphyseal region of the tibia of 12 rabbits. For the bone defect reconstruction there was implanted a combination of micro and macro fragments of heterologous fragmented cortical bone matrix preserved in glycerin (98%) and polymethylmethacrylate, both autoclaved. Radiological and macroscopic evaluation was performed at 30, 60, 90 and 120 days. Adhesion in relation to time of the micro and macro composites to the recipient bed was observed in 100% of the cases. This showed that this implant is biologically biocompatible, since it promoted bone defects repair, with no signs of infection, migration and/or rejection. In this way, this implant can be classified as one more option of substitute to fill large bone defects.

Placas ósseas confeccionadas a partir de diáfise cortical equina na osteossíntese femoral em coelhos / Bone plates produced from equine cortical bone in rabbits femoral osteosynthesis

A evolução tecnológica tem possibilitado o desenvolvimento e o aperfeiçoamento de novos materiais para implantes. Apesar dos fundamentais benefícios providos pelos dispositivos ortopédicos, complicações decorrentes de corrosão, degradação, infecção, além de outras podem ocorrer. O entendimento das características dos biomateriais é fundamental para a previsibilidade do seu comportamento in vivo, fornecendo subsídios para que o composto mais adequado seja escolhido na reconstrução do defeito ósseo. As placas de origem metálica são as mais utilizadas para o reparo de fraturas de ossos longos, sendo mecanicamente resistentes e biocompatíveis. No entanto, a necessidade de remoção e o enfraquecimento do osso são suas principais desvantagens. Neste trabalho, placas produzidas a partir de osso cortical equino foram empregadas experimentalmente em fêmur osteotomizado de coelhos (Grupo osso-GO), num estudo comparativo com placas de metal (Grupo metal-GM). A avaliação radiográfica foi realizada a cada 30 dias, durante 120 dias, momento em que foi então realizada análise histológica do material em estudo. Não houve diferença estatisticamente significante entre os dois grupos com relação à morfometria do calo ósseo e consolidação óssea em todos os momentos avaliados, sendo que ambas as placas permitiram a consolidação em todos os animais. Entretanto, observou-se que o calo ósseo foi menor no GO, em relação ao GM, em todos os momentos do estudo. Por outro lado, a maior parte dos animais do GO apresentou consolidação completa da fratura aos 90 dias, enquanto que no GM isto ocorreu aos 60 dias. Não foram evidenciadas células do tipo corpo estranho na histopatologia dos animais do GO, mas maior quantidade de tecido fibroso foi identificada, envolvendo este biomaterial. A placa confeccionada com osso equino representa uma alternativa de baixo custo e muito viável, uma vez que permitiu estabilização adequada para consolidação óssea de fratura de fêmur em ...

Actually, technological advances have contributed to the development and improvement of new materials for implants. Despite the fundamental benefits provided by orthopedic materials, complications resulting from corrosion, degradation, infection, and others may occur. The knowledge of characteristics of the biomaterials is important to predict their behavior in vivo, supporting that the most suitable compound is chosen to reconstruct the bone defect. Metallic plates are the most common material used for repair of long bone fractures, and they are mechanically stable and biocompatible. However, the need of removal and bone weakening are their disadvantages. In this paper, plates made from equine cortical bone were used experimentally in osteotomized rabbit femur (bone-GO Group), in a comparative study with metal plates (metal GM Group). Radiographic evaluation was performed every 30 days during 120 days, at which time was then performed femur histological analysis. During all evaluated moments of the study, there was no statistically significant difference between the two groups in callus morphometry, and complete consolidation was observed in all animals. However, it was observed that the callus was lower in GO compared to GM, all times during the study. Moreover, most of the GO animals showed complete consolidation fracture at 90 days only, whereas this occurred in GM at 60 days. There were no foreign-body cells in the histopathology exam of the GO animals, but larger amount of fibrous tissue was identified, involving this biomaterial. The plate made from horse bone represents a low cost alternative and it is very feasible, it allowed adequate stabilization of femur fracture in rabbits. In this study, the lower periosteal callus associated with a longer time for consolidation in GO suggest greater fracture stability when the bone plate was used.

Uso do plasma rico em plaquetas no reparo de úlceras de córnea profundas induzidas em coelhos. Avaliação clínica e histomorfométrica / Use of platelet-rich plasma in the treatment of deep corneal ulcers induced in rabbits. Clinical and histomorphometric evaluation

Avaliou-se e comparou-se, clinicamente, por meio de histopatologia e morfometria, o processo de reparação corneana de úlceras experimentais induzidas em coelhos, com o uso de plasma rico em plaquetas (PRP) sob a forma de colírio ou tampão. Foram utilizados 60 coelhos, constituindo-se quatro grupos experimentais de 15 animais cada, designados grupo plaqueta (GP), grupo tampão (GT), grupo controle (GC) e grupo controle amniótica (GA). Os grupos experimentais foram subdivididos em três subgrupos (M4, M7, M30), de acordo com o período final de avaliação, aos quatro, sete e 30 dias, respectivamente. Não houve diferenças entre os tratamentos utilizados quanto aos sinais relacionados à sensibilidade ocular, quemose e secreção ocular. Os grupos tratados com PRP, na forma de tampão ou colírio, apresentaram menor opacidade corneana do que os animais tratados apenas com membrana amniótica no momento final de avaliação. Quanto à presença da úlcera corneana, os grupos tratados com PRP apresentaram menor ulceração corneana em relação aos demais grupos. No exame histomorfométrico, verificou-se maior epitelização corneana na fase inicial da lesão no tratamento à base de colírio de plasma rico em plaquetas. O uso da membrana amniótica promoveu espessamento do epitélio e estroma corneano, com sinergismo dela quando associada ao plasma rico em plaquetas.

The repair process induced corneal ulcer in rabbits using platelet-rich plasma in the form of eyedrop or clot was clinically evaluated and compared. Sixty rabbits were divided into four groups of 15 animals, denominated platelet group (PG), clot group (CLG), control group (CG), and amniotic control group (AG). Experimental groups were then subdivided into three groups (M4, M7, M30), corresponding to the end of the evaluation period. There were no differences between treatments regarding ocular sensitivity, chemosis and ocular secretion. The groups treated with PRP either as eyedrop or a clot showed less opacity than the animals treated only with amniotic membrane at the moment of the final evaluation. The presence of corneal ulcers in the groups treated with PRP showed lower intensity than the other groups. Histomorphometric examination showed that corneal epithelization in the initial phase of the lesion was greater when using PRP. The use of amniotic membrane promoted corneal epithelial and stromal thickness, as well as synergism when associated to PRP.

Epidemiologic survey in Swiss group-housed breeding rabbits: extent of lesions and potential risk factors.

In Switzerland, group-housing for breeding rabbit does is not explicitly required by law, but label programmes, as well as the general public and animal welfare groups, are advocating it. Although group-housing is of great benefit to the gregariously living rabbits, the establishment of a social hierarchy within the group might lead to stress and lesions. In the present epidemiological study, lesions were scored twice on 30% of the breeding does on all 28 commercial Swiss farms with group-housed breeding does. Additionally, a detailed questionnaire was filled out with all producers to determine risk factors potentially associated with lesions. Data were analysed using hierarchical proportional odds models. About 33% of the does examined had lesions, including wounds that were almost healed and small scratches. Severe lesions were counted on 9% of the animals. Differences between seasons in lesions score were identified, with the extent of lesions being higher in summer than in spring. Fewer lesions occurred on farms on which mastitis was more common. More lesions were found on farms where the does were isolated between littering and artificial insemination than on farms without isolation. According to the producers, most of the aggression occurred directly after the isolation phase when the does were regrouped again. We conclude that lesions in group-housed breeding does might be reduced by appropriate reproductive management.

Uso do colírio de Citrus lemon em úlceras de córnea induzidas em coelhos / Use of Citrus lemon eyedrops in corneal ulcers induced in rabbits

Avaliaram-se e compararam-se clinicamente os efeitos de colírios de Citrus lemon (CL) na reparação de úlcera corneal superficial. Foram utilizadas 50 coelhas, distribuídas em cinco grupos experimentais de 10 animais cada. Após a indução da úlcera, três grupos foram tratados com colírios de CL, nas concentrações de 1,5% (GL1,5), 3% (GL3) e 5% (GL5). Um quarto grupo foi tratado com Tween 80 a 8%, diluente utilizado na produção dos colírios de CL, e o quinto grupo, controle, recebeu substituto da lágrima. Os grupos foram distribuídos em dois subgrupos de cinco animais; assim, o primeiro (M1) foi avaliado após 24 horas, e o segundo (M5) após cinco dias. Não houve diferença entre os tratamentos quanto aos sinais clínicos secreção, hiperemia conjuntival, quemose e opacidade corneal. A extensão da úlcera corneal diminuiu, de forma significativa, em todos os grupos no M5, com exceção do GL3, o qual apresentou menor mediana quanto à extensão no M1. O colírio de óleo essencial de Citrus lemon pode ser utilizado no tratamento de ceratites ulcerativas superficiais, sem induzir irritação conjuntival, favorecendo a reepitelização corneal.

The aim of this study was to clinically evaluate and compare the effects of Citrus lemon (CL) eye drops in the repair of superficial corneal ulcers. Fifty female rabbits were used, constituting five experimental groups with 10 animals each. After ulcer induction, three groups were treated with CL eye drops, at 1.5% (GL1, 5), 3% (GL3) and 5% (GL5) concentrations. Another group was treated with Tween 80 8% solvent used in the production of CL eye drops, and the control group received tear substitute. The experimental groups were divided into two subgroups (five animals). The first (M1) was evaluated after 24 hours and the second (M5) after five days. There was no difference between treatments for clinical signs of secretion, conjunctival hyperemia, chemosis and corneal opacity. The extension of corneal ulcer significantly decreased in all groups in M5, the exception was GL3, which had a lower median of extension in the M1. The eye drops made of Citrus lemon essential oil can be used in the treatment of superficial ulcerative keratitis, without inducing conjunctival irritation, favoring corneal reepithelialization.

A case of traumatic myiasis in a domestic rabbit (Oryctolagus cuniculus) caused by Lucilia sericata.

Lucilia sericata is one of the factors resulting in facultative traumatic myiasis in animals and humans. L. sericata threatens human health and leads to significant economic losses in animal industry by leading to serious parasitic infestations. A three month old female rabbit was presented to the clinics of the Veterinary Faculty of Dicle University for the treatment of the wound located on the left carpal joint. The examination revealed that the wound was infested with larvae. The microscopic inspection of the larvae collected from the rabbit showed that they were the third instar larvae of L. sericata.

Histopathological characterization of experimentally induced cutaneous loxoscelism in rabbits inoculated with Loxosceles similis venom

Envenomation by Loxosceles bites is characterized by dermonecrotic and/or systemic features that lead to several clinical signs and symptoms called loxoscelism. Dermonecrotic lesions are preceded by thrombosis of the dermal plexus. Recent studies show that atheromatous plaque is prone to thrombosis due to endothelial cell apoptosis. To the best of our knowledge, there are no reports of microscopic dermal lesion and endothelial cell apoptosis induced by Loxosceles similis venom in the literature. Thus, the aim of the present study is to describe histological lesions induced by L. similis venom in rabbit skin and to elucidate whether apoptosis of endothelial cells is involved in the pathogenesis of loxoscelism. Forty male rabbits were split into two groups: the control group (intradermally injected with 50 µL of PBS) and the experimental group (intradermally injected with 0.5 µg of L. similis crude venom diluted in 50 µL of PBS). After 2, 4, 6 and 8 hours of injection, skin fragments were collected and processed for paraffin or methacrylate embedding. Sections of 5 µm thick were stained by HE, PAS or submitted to TUNEL reaction. Microscopically, severe edema, diffuse heterophilic inflammatory infiltrate, perivascular heterophilic infiltrate, thrombosis, fibrinoid necrosis of arteriolar wall and cutaneous muscle necrosis were observed. Two hours after venom injection, endothelial cells with apoptosis morphology were evidenced in the dermal plexus. Apoptosis was confirmed by TUNEL reaction. It seems that endothelial cell apoptosis and its consequent desquamation is an important factor that induces thrombosis and culminates in dermonecrosis, which is characteristic of cutaneous loxoscelism.

[Fractures and luxations in small mammals]. / Frakturen und Luxationen beim Kleinsäuger.

Most traumata in small mammals occur at home. Diagnosis and therapy can be compared with that in the dog and cat, but species-specific differences have to be considered. For fracture treatment a butterfly-cast can be sufficient for stabilization in special cases. In most cases satisfying results can be obtained with a "tie-in-fixator" treatment. Dislocations of the elbow joint are treated by reduction or stabilization through suture techniques or temporary arthrodesis.

Patterns of sudanophilic lesions at ostia of descending thoracic and abdominal aorta in cholesterol-fed adult rabbits / Patrones de lesiones sudanofílicas en el ostio de las partes torácica y abdominal de la aorta en conejos adultos alimentados con colesterol

Sudan-positive atherosclerotic lesions preferentially occur at downstream and lateral margins of arterial branch ostia in human neonates and weanling rabbits but tend to develop at lateral and upstream margins in old subjects. We investigated (i) the pattern of sudanophilic lesions at aortic ostia of cholesterol-fed adult rabbits and (ii) determined any differences in lesion distribution between descending thoracic and abdominal aorta. Ten adult males, New Zealand white rabbits were fed 2 percent high cholesterol diet. After six weeks, aortas were excised, opened longitudinally and stained with Sudan-IV for gross examination of atherosclerotic lesions. A total of 156 descending thoracic and 90 abdominal ostia were examined. Mean lesion frequencies upstream, downstream and at lateral margins of the affected ostia were calculated and compared. Sudanophilic lesions were detected around 32 percent ostia of descending thoracic aorta and 25 percent those of abdominal aorta. At ostia of descending thoracic aorta, lesion frequencies were significantly higher (P<0.001) downstream (95 percent) and at lateral margins (92 percent) than upstream (2 percent). In abdominal aorta, lateral (100 percent) and upstream (43 percent) margins were significantly (P<0.05) more affected while minimal lesion frequencies were seen at downstream branch points (9 percent). Comparison between descending thoracic and abdominal aorta showed an insignificant difference of lesion frequencies at lateral margins (P>0.05) but a highly significant difference at upstream versus downstream of ostia (P<0.001). We concluded that in cholesterol-fed adult rabbits, juvenile pattern of downstream lipid deposition persists at ostia of descending thoracic aorta while a switch towards the upstream pattern of old subjects occurs at ostia of abdominal aorta.

Las lesiones ateroscleróticas Sudán-positivas se producen preferentemente en los márgenes posteriores y laterales del ostio de las ramas arteriales en neonatos humanos y en conejos destetados, pero tienden a desarrollarse en los márgenes laterales y superiores en sujetos de edad avanzada. Investigamos el patrón de lesiones sudanofílicas en el ostio aórtico de conejos adultos alimentados con colesterol y determinamos las diferencias en la distribución de lesiones entre la aorta torácica descendente y abdominal. Diez conejos machos blancos adultos New Zealand fueron alimentados con una dieta alta en colesterol al 2 por ciento. Después de seis semanas, fueron extraídas las aortas, se disecaron longitudinalmente y se tiñeron con Sudan-IV para el examen macroscópico y se observaron las lesiones ateroscleróticas. Fueron examinados 156 ostios de aortas torácicas descendentes y 90 de aortas abdominales. Fueron calculadas y comparadas las frecuencias medias de lesiones superiores, inferiores y de los márgenes laterales de los ostios afectados. Las lesiones sudanofílicas se detectaron en alrededor del 32 por ciento de ostios de la aorta torácica descendente y en el 25 por ciento de las aortas abdominales. En el ostio de la aorta torácica descendente, las frecuencias de lesiones fueron significativamente mayores (p <0,001) por superior (95 por ciento) y en los márgenes laterales (92 por ciento) que por inferior (2 por ciento). En la aorta abdominal, los márgenes laterales (100 por ciento) y superiores (43 por ciento) fueron significativamente más afectados (p <0,05), mientras que las frecuencias mínimas de lesiones se observaron en los puntos de la rama descendente (9 por ciento). La comparación entre la aorta torácica descendente y abdominal mostró una diferencia no significativa de las frecuencias de lesiones en los márgenes laterales (p> 0,05), pero muy significativa al comparar el margen superior con el inferior (p <0,001). Llegamos a la conclusión que en los conej...