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Indiana University-Purdue University Indianapolis (IUPUI) / Root surface caries is an increasing problem in the United States as more of the population are retaining their teeth to an older age. The disease requires the recession of gingival tissue and resorption of alveolar bone prior to exposure of the root surface. Animal models for root surface caries provide a means to investigate the etiology and treatment of the disease. The Golden Syrian hamster has been used as a model, and alveolar bone loss and root exposure are induced by feeding the animals a high glucose diet. Significant bone loss, when compared to control groups, is usually detected within five weeks. At present, the use of non-steroidal anti-inflammatory drugs in the treatment of periodontal disease is an area of great interest. As there is a role of host response in the alveolar bone destruction seen in periodontitis, inhibition of this prostaglandin-mediated process may provide a means of treatment. Flurbiprofen (Ansaid™, Upjohn Co., Kalamazoo, Ml) has been widely studied and appears to inhibit this bone loss in a variety of animals, including man. The purposes of the study were to determine if the early alveolar bone loss occurring after three, four and five weeks' exposure to the high carbohydrate diet could be quantitated with fluorescent bone labels, and if this bone loss could be inhibited by daily administration of flurbiprofen. The animals received a series of four intraperitoneally-injected fluorochrome labels over a one-month period, then were fed ground lab chow, the high carbohydrate MIT-200GI diet or the MIT-200GI diet plus flurbiprofen. At the end of three, four and five weeks, animals were euthanized, and the mandibles were prepared for analysis. Statistical analysis of gross and histomorphometric measurements detected no significant differences between the experimental groups. It is suspected that the diets failed to produce periodontal disease in this experiment, possibly due to changes in the oral microflora caused by administration of tetracycline as the final bone label. There was much variation in the presence of bone labels, but they were able to provide the growth velocity of the alveolar complex. Flurbiprofen administration produced no measurable effects, but the animals did tolerate the dosage given. Future studies should consider variation of the labels and a different route of administration.

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Fentanyl has historically been used to reduce inhalant anesthetic requirements in the dog, with the end goal of reducing detrimental cardiovascular effects seen with their use. While fentanyl has been investigated in this context with the older agent enflurane, this agent is no longer in common use. In the current literature, no studies exist that compare the effects of low and high doses of fentanyl on cardiovascular function in dogs anesthetized with isoflurane. In previous literature, a high dose of fentanyl improved cardiovascular function in enflurane anesthetized dogs only following correction of bradycardia associated with its use. The objective of this study was to evaluate the effect of two doses of fentanyl on isoflurane requirement in the dog, followed by an evaluation of cardiovascular function in the isoflurane-anesthetized dog at equivalent depth of anesthesia. The hypothesis was that fentanyl would reduce inhalant requirements in a dose dependent fashion, and that cardiovascular function would increase with fentanyl administration only following correction of bradycardia. A total of 8 healthy adult male beagle dogs were enrolled in this study, which was performed in a randomized cross-over design. Minimum Alveolar Concentration (MAC) was determined in these dogs via a 30 mA electric stimulation both before and after administration of a low (loading dose 30 µg/kg, continuous rate infusion (CRI) of 0.2 µg/kg/minute) or high (loading dose 90 µg/kg, CRI 0.8 µg/kg/min) dose of fentanyl. A 7-day washout was observed between experimental days. Following MAC determination, in a subsequent anesthetic episode animals were placed at a MAC multiple of 1.3 and cardiovascular and blood gas parameters were evaluated before and after each fentanyl dose in the presence and absence of bradycardia. Fentanyl decreased MAC in a dose-dependent fashion (p < 0.001), with the low dose reducing MAC by about 42% and the high dose by about 77%. MAC reduction, however, did not translate into improvement in cardiovascular function, with a significant reduction in cardiac index and oxygen delivery noted with both doses (p < 0.01) that was not different between treatments. Normal mean arterial pressures were maintained with both treatments despite these effects. Only with the high dose, however, correction of bradycardia caused an increase in both cardiac index and oxygen delivery (p < 0.02) when compared to isoflurane alone. In clinically healthy dogs, administration of a high dose of fentanyl increased cardiac function following correction of bradycardia, but a decrease was observed when bradycardia went uncorrected. Further studies are needed in order to evaluate these effects in clinical patients. / Master of Science / Fentanyl, a potent opioid painkiller, has historically been used to reduce inhalant anesthetic requirements in the dog, with the end goal of reducing detrimental effects on the heart and blood vessels seen with their use. While fentanyl has been investigated in this context with the older agent enflurane, this agent is no longer in common use. In the current literature, no studies exist that compare the effects of low and high doses of fentanyl on heart function in dogs anesthetized with isoflurane. In previous literature, a high dose of fentanyl improved blood flow in enflurane anesthetized dogs only following correction of the low heart rate associated with its use. The objective of this study was to evaluate the effect of two doses of fentanyl on isoflurane requirement in the dog, followed by an evaluation of heart function and blood flow in the isoflurane-anesthetized dog at equivalent depth of anesthesia. The hypothesis was that fentanyl would reduce isoflurane requirements in a dose dependent fashion, and that heart function would increase with fentanyl administration only following correction of low heart rate. A total of 8 healthy adult male beagle dogs were enrolled in this study, which was performed in a randomized cross-over design. Inhalant anesthetic requirement was assessed with an electric stimulation both before and after administration of a low or high dose of fentanyl. A 7-day washout was observed between experimental days. In a subsequent anesthetic episode animals were placed at a surgical anesthetic depth and cardiac and blood gas parameters were evaluated before and after each fentanyl dose in the presence and absence of low heart rate. Fentanyl decreased inhalant requirements in a dose-dependent fashion. This did not translate into improvement in cardiovascular function, with a significant reduction in blood flow and oxygen delivery noted with both doses that was not different between treatments. Normal blood pressure was maintained with both treatments despite these effects. Only with the high dose, however, correction of low heart rate caused an increase in both blood flow and oxygen delivery when compared to isoflurane alone. In clinically healthy dogs, administration of a high dose of fentanyl increased heart function following correction of low heart rate, but a decrease was observed when the low rate went uncorrected. Further studies are needed in order to evaluate these effects in clinical patients.

A principal causa da disfunção respiratória em equinos durante anestesia geral inalatória é atribuída à hipoxemia devido a formação de áreas de atelectasias. Visando reverter estes quadros são instituídas as manobras de recrutamento alveolar (MRA) através da administração de elevadas pressões no sistema respiratório. Estas manobras quando utilizadas de maneira inadequada podem contribuir para a formação de atelectasias, barotrauma, volutrauma e até mesmo atelectrauma; sendo de suma importância a sua monitoração. Com isso, uma nova técnica, a tomografia por impedância elétrica (TIE), vem sendo estudada, no qual, seu funcionamento se dá por emissão de corrente elétrica de baixa frequência e intensidade nos tecidos, gerando uma imagem dos tecidos avaliados. Sendo assim, o objetivo do presente estudo experimental foi avaliar se na espécie equina a TIE é capaz de visualizar as alterações de volume corrente global e regional, em pulmões saudáveis, durante a ventilação mecânica e escalonamento da PEEP como MRA. Para tanto foram utilizados 14 equinos de peso médio de 306 kg, submetidos a anestesia geral inalatória em decúbito dorsal. Os animais foram mecanicamente ventilados com volume corrente de 14 mL/kg e frequência respiratória de 7-9 mpm. Foi instituída manobra de recrutamento alveolar, aumentando-se a PEEP de 5 em 5 cmH2O, a cada 5 minutos, até 32 cmH2O, seguido de seu decréscimo também de 5 em 5 cmH2O, a cada 5 minutos, até 7 cmH2O. Foram realizadas coletadas de amostras de sangue arterial para hemogasometria, imagens do TIE e registrados os parâmetros hemodinâmicos e de mecânica respiratória em cada estágio do escalonamento da PEEP. Durante a MRA foram observados aumento na PaO2/FiO2 dos pacientes assim como aumento na complacência estática pulmonar, associado a uma diminuição no shunt pulmonar, e deslocamento da ventilação para região pulmonar dependente por meio da TIE, principalmente em PEEP acima de 17 cmH2O. Como efeitos adversos foram observados alterações em parâmetros hemodinâmicos sendo estas transitórias. Portanto o TIE demonstrou-se capaz de avaliar as mudanças de ventilação pulmonar durante a MRA e mostrou relação com os ganhos em oxigenação e mecânica pulmonar. / The main cause of respiratory dysfunction in horses under isoflurane anaesthesia is hypoxemia attributed to the atelectasis formation areas. In order to revert these sets, alveolar recruitment manoeuvres (ARM) are instituted through high pressures administration in the respiratory system. These manoeuvres when used improperly can contribute to the atelectasis formation, barotrauma, volutrauma and even atelectrauma; being of utmost importance its monitoring. A new technique, electrical impedance tomography (EIT), has been studied, in which its operation is due to the low frequency and intensity of electric current emission in the tissues, generating tissues images for evaluation. Therefore, the present experimental study aimed to evaluate whether in horses the EIT is able to visualize changes of global and regional tidal volume in healthy lungs during mechanical ventilation and titration of PEEP as ARM. For this purpose, 14 horses weighting 306 kg were used, undergoing general inhalation anaesthesia in dorsal recumbence. The animals were mechanically ventilated with tidal volume of 14 mL/kg and respiration rate of 7-9 bpm. An alveolar recruitment manoeuvre was instituted, increasing the PEEP by 5 cmH2O every 5 minutes until 32 cmH2O, followed by decreasing it by 5 cmH2O every 5 minutes to 7 cmH2O. Arterial blood samples were collected for hemogasometry, EIT images and hemodynamic parameters and respiratory mechanics were recorded at each stage of PEEP. During ARM, patients\' PaO2/FiO2 increased as well as increased pulmonary static compliance, associated with a decrease in pulmonary shunt, and pulmonary ventilation moving to dependent areas, mainly when 17 cmH2O or more were applied. As adverse effects were observed transient changes in hemodynamic parameters. So TIE is capable of presenting the changes in pulmonary ventilation in horse in dorsal recumbency undergoing ARM, and showed good relation to oxygenation gain and respiratory mechanics.

O trabalho teve como objetivo avaliar e quantificar o tecido ósseo neoformado, a distribuição e a importância das proteínas não colágenas (osteocalcina, osteopontina e osteonectina) no processo de reparação tecidual do alvéolo dental de ratos Wistar idosos após exodontia. Para sua realização, foram utilizados 80 Rattus Norvegicus albinus, linhagem Wistar, machos. Os animais foram distribuídos em dois grupos: Grupo Controle, correspondente a animais com 60 dias de vida; e Grupo Experimental correspondente aos animais com 2 anos de vida (700 dias em média). Cada grupo foi dividido em 4 subgrupos de 10 animais em cada grupo. Os animais foram submetidos à exodontia do incisivo superior direito e foram sacrificados com 05, 15, 21 e 28 dias de pós-operatório. Após a dissecção, 5 amostras foram submetidas à análise por microscopia convencional com coloração por Hematoxilina e Eosina e análise da imunohistoquímica e 5 amostras para análise por RT-PCR. Os resultados mostraram que o processo de envelhecimento não alterou a cronologia do reparo ósseo alveolar e não promoveu maior remodelação do alvéolo dental. A osteocalcina não apresentou atuação importante nos períodos pós-operatórios estudados. A osteonectina apresentou-se importante no processo de reparo, não sofrendo alterações no início da reparação óssea, apresentando marcação mais intensa durante a maturação óssea entre 21 e 28 dias de pós-operatório no grupo controle e diminuição da marcação no grupo experimental aos 28 dias de pósoperatório. O envelhecimento proporcionou uma diminuição da imunomarcação da osteonectina e demonstrou marcações positivas principalmente em osteoblastos e matriz mineralizada. A osteopontina apresentou-se importante no processo de reparo ósseo durante todos os períodos pós-operatório, apresentando marcações em osteoblastos, matriz osteóide, osteócitos e matriz mineralizada, apresentando maior marcação dos tipos celulares do no grupo experimental aos 28 de pós-operatório. Apesar desses achados, novos estudos são necessários para o melhor entendimento do processo de reparo ósseo alveolar em ratos adultos e idosos. / The aim of the present study was to evaluate and quantify the newly formed bone tissue, as well as the distribution and the importance of non-collagen proteins (osteocalcin, osteopontin and osteonectin) in the process of dental alveolar repair in Wistar aged rats submitted to tooth extraction. To perform that, about 80 male Rattus Norvegicus albinus, Wistar strain, were randomly distributed into two groups: Control Group corresponding to 60 days old rats; and Experimental Group corresponding to 2 years old animals (about 700 days old). Both groups were later subdivided into 4 subgroups consisting of 10 animals each. All animals were submitted to the upright incisive tooth extraction and were euthanized 05, 15, 21 and 28 days after the tooth extraction surgery. After the dissection, five samples from each subgroup underwent conventional microscopy analysis by hematoxylin-eosin stain as well as immunohistochemistry. Bone tissue from other five samples of each groups were subjected to Real Time RT-PCR analysis of non-collagen proteins expression The results obtained suggest that aging process was not able to change either the chronology of alveolar bone repair or the remodeling of dental alveolus. Osteocalcin did not present any important action in the post-operation periods evaluated. On the other hand, osteonectin showed an important role during the repair process, since its expression was increased in the control group and decreased in comparison to the experimental group at 28 days. Osteopontin was important in the bone repair in all times evaluated, since it was present in osteoblasts, osteiod matrix, osteocytes and mineralized matrix, being even more stained at 21 days after the surgery. Finally, besides the results obtained in the present work, other studies are necessary to better understand the alveolar bone repair in adult and aged rats.