Roseli de Oliveira Mollerke

Modelo experimental de aneurisma sacular de artéria ilíaca comum com pericárdio bovino em suínos

Objective: To develop an experimental model of saccular pseudoaneurysm of the common iliac artery with bovine pericardium in pigs. Method: The animals used were two 30-kg female pigs from the Landrace specimen. The animals were submitted to general anesthesia and laparotomy with extraperitoneal access to infrarenal aorta and the iliac arteries. After systemic heparin and clamping, the iliac artery was opened and the pericardium sutured to the vessel wall. All animals were confined for 3 weeks and were sacrificed after performing an arteriography to verify the patency of the aneurysm. Result: All animals survived the procedure and the aneurysms were patent. No rupture was detected. Conclusion: This is a feasible pig model of iliac artery aneurysm with potential for further studies to develop new endovascular prostheses.

Distortion product otoacoustic emissions in sheep before and after hyperinsulinemia induction

UNLABELLED Transient evoked otoacoustic emissions and distortion product otoacoustic emissions have gained significant importance in the identification of cochlear alterations. AIM To record distortion product thresholds through the monitoring of otoacoustic emissions in normal conditions and in the presence of electrophysiologic changes in cochlear outer hair cells in sheep after hyperinsulinemia induction. MATERIAL AND METHODS Experimental study, with seven sheep in the control group and seven in the study group. Insulin and glucose concentrations were measured simultaneously for the recording of distortion product otoacoustic emission every 10 minutes, all the way to 90 minutes. The control group received saline solution, and the study group received a bolus injection of 0.1 U/kg of regular human insulin. RESULTS There was a significant reduction in distortion product thresholds in the study group when compared to the control group at frequencies greater than 1,500 Hz and after 60 minutes (P < 0.001). CONCLUSION This study established distortion product otoacoustic emission thresholds in sheep with constant reproducibility, demonstrating that the method is adequate for use in audiology and otology investigations. Results also fully confirm that acute hyperinsulinemia may cause important changes in these thresholds.

Emissões otoacústicas por produtos de distorção em ovinos normais e após indução de hiperinsulinemia

As emissoes otoacusticas transientes evocadas e as emissoes otoacusticas por produtos de distorcao vem assumindo importância significativa na identificacao de alteracoes cocleares. OBJETIVO: Atraves da monitorizacao das emissoes otoacusticas, registrar os limiares dos produtos de distorcao em condicoes normais e na presenca de modificacoes eletrofisiologicas nas celulas ciliadas externas cocleares de ovelhas apos a inducao de hiperinsulinemia aguda. MATERIAL E METODO: Estudo experimental com sete ovelhas no grupo-controle e sete no grupo-estudo. Os niveis de insulina e glicose foram verificados simultaneamente ao registro das emissoes otoacusticas por produtos de distorcao de 10 em 10 minutos, ate o tempo de 90 minutos. O grupo-controle recebeu soro fisiologico, e o grupo-estudo, injecao em bolo de 0,1 U/kg de insulina humana regular. RESULTADOS: Houve diminuicao significante nos limiares dos produtos de distorcao no grupo-estudo em relacao ao grupo-controle nas frequencias acima de 1.500 Hz e apos o tempo de 60 minutos (P < 0,001). CONCLUSAO: O estudo permitiu estabelecer os limiares das emissoes otoacusticas por produtos de distorcao em ovelhas com constante reprodutibilidade, o que mostra que o metodo e adequado para uso em investigacoes audiologicas e otologicas. Ficou, ainda, plenamente identificado que o hiperinsulinismo agudo foi capaz de provocar relevantes modificacoes nestes limiares.

Aterogênese em artéria ilíaca comum de suínos submetidos à homocisteinemia induzida pela ingestão de metionina

Objective: To assess the effects of induced homocystinemia in the swine iliac artery. Material and method: A comparative experimental study with two homogeneous groups of seven pigs from the Macao specimen, weighed between 20 and 30 kg, which were assessed during 30 days. The pigs were divided into two groups. One of them was fed with a methionine-rich diet for a 4-week period. Blood samples were collected for analyses of total cholesterol, triglycerides, HDL and homocysteine concentrations. The animals were submitted to arteriography to evaluate the patency of iliac arteries and then sacrificed. The iliac artery segment was removed for histological analysis. Results: All animals survived the procedure, and there were no significant changes in total cholesterol, triglycerides and HDL concentrations in both groups. Microscopic examinations of the control group did not show pathological changes and was similar in all analyses. In the group receiving the methionine diet, the plaques were formed by foamy macrophages, but smooth muscle cells, cholesterol crystals or inflammatory cells were not seen. The tunica media had the internal elastic lamina intact. In the control group, there was no change in homocysteine levels during the experiment. In the methionine group, there was an increase in plasma homocysteine levels, with an average value of 59.80 µmol/l after 30 days with a methionine-rich diet. Conclusion: Homocystinemia induced by methionine causes atherogenesis in the swine iliac artery.

Gastric Yield Pressure and Gastric Yield Volume to Assess Anti-Reflux Barrier in a Porcine Model

ABSTRACT Anti-reflux barrier (ARB) resistance may be useful to test new treatments for gastroesophageal reflux (GER). The ARB has been estimated by increasing gastric yield pressure (GYP) and gastric yield volume (GYV) in animal models but has not been validated. This study aimed to develop an experimental model suitable for assessing the ARB resistance to increasing intragastric pressure and volume and its reproducibility in a seven-day interval. Ten two-month-old female Large-White swine were studied. Intragastric pressure and volume were recorded using a digital system connected to a Foley catheter inserted through gastrostomy into the stomach. GYP and GYV were defined as the gastric pressure and volume able to yield gastric contents into the esophagus detected by esophageal pH. A sudden pH drop below 3 sustained during 5 min was considered diagnostic for gastric yield. Animals were studied again after seven days. On days 0 and 7, there were no significant differences for GYP (mean ± SD = 7.66 ± 3.02 mmHg vs. 7.07 ± 3.54 mmHg, p = .686) and GYV (636.70 ± 216.74 ml vs. 608.30 ± 276.66 ml; p = .299), respectively. Concordance correlation coefficient (ρc) was significant for GYP (ρc = 0.634, 95% CI = 0.141–0.829, p = .006), but not for GYV (ρc = 0.291, 95% CI = −0.118 to 0.774, p = .196). This study demonstrated an experimental model, assessing the ARB resistance. GYP seems to be a more reliable parameter than GYV for assessment of ARB resistance.

11:10 AM: Sheep: An Experimental Animal Model for Research in Otology

ential of implanting one versus two cochlear implants. RESULTS: Results indicate a 0.48 mean gain in health utility after bilateral cochlear implantation and a discounted cost per QALY of

Endoscopic implantation of polymethylmethacrylate augments the gastroesophageal antireflux barrier: a short-term study in a porcine model

24,859 in this cohort of patients. By comparing patient scores for unilateral and bilateral use, improvements in the domains of hearing, speech, emotion and cognition were noted, resulting in a mean gain in health utility of 0.11. Using this comparison, the discounted cost-utility differential between unilateral and bilateral cochlear implant placement was

Desenvolvimento de modelo de hipóxia intermitente em animal

2,154. CONCLUSION: This study found an improvement in quality of life and a favorable cost-utility associated with bilateral cochlear implantation in patients with profound hearing loss. The results also indicate that these patients showed additional improvements in quality of life after they received their second implant. Bilateral cochlear implantation was also cost-effective when compared to unilateral cochlear implant placement and can be offered as a beneficial, life-improving therapy in patients with severe hearing loss. SIGNIFICANCE: This is the first study showing improvements in quality of life and a favorable cost-utility after bilateral cochlear implantation in patients with profound hearing loss.