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Experimental Animal Study (experimental + animal_study)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Temperature controlled burn generation system based on a CO2 laser and a silver halide fiber optic radiometer

LASERS IN SURGERY AND MEDICINE, Issue 5 2003
Meir Cohen MD
Abstract Background and Objectives Experimental animal study of burns is dependent on a reliable burn generation system. Most of the experimental systems used today are unable to produce precise partial thickness burns. This limits the ability to study minor changes associated with burn care. The aim of the study was to develop a method for generating burns with a fixed depth using a CO2 laser burn generation system. Materials and Methods The burn generation system was composed of two components: a burn generation device and a temperature sensing and control system. These components were designed to operate together in order to keep a constant, predetermined skin surface temperature during prolonged burn generation. One hundred thirty-eight spot burns were generated on the back of five shaved 450 g male Wistar rats. The rat skin was exposed to a 70°C for 5,60 seconds. The burned areas were excised and underwent evaluation by hematoxylin-eosin-stained slide microscopy. Results A linear correlation was found between the duration of exposure and the average burn depth (r,=,0.93). This correlation is represented by the equation: burn depth in millimeters,=,0.012×,(duration in seconds of skin exposure at 70°C). Conclusions The fiber-optic-controlled laser burn generation system studied is a reliable tool for creating partial thickness as well as full thickness skin burns in rats. Lasers Surg. Med. 32:413,416, 2003. © 2003 Wiley-Liss, Inc. [source]

The effect of topical sodium thiosulfate in experimentally induced myringosclerosis,

THE LARYNGOSCOPE, Issue 7 2010
Yong Ho Park MD
Abstract Objectives/Hypothesis: The purpose of this study was to investigate the effect of topical sodium thiosulfate (STS) in experimentally induced myringosclerosis (MS). Study Design: A prospective experimental animal study. Methods: Thirty Wistar albino rats were bilaterally myringotomized. The right ears were treated with STS or saline daily, and the left ears were left untreated and used as controls. The tympanic membranes were observed by otoendoscopy weekly, and tympanometric measurements were performed. All animals were histopathologically examined for myringosclerotic plaques. Results: Under otoendoscopy, myringosclerosis were observed around the handle of the malleus and near the annular region. The numbers of myringosclerotic ears were significantly more frequent in control and saline groups compared with the STS group (P < .05), and the formation of MS was more severe in control and saline groups compared with STS group (P < .05). Using tympanometric measurement, significantly reduced magnitudes of maximum admittance were observed in control and saline groups compared to normal and STS groups (P < .05). Under histopathologic examination, the tympanic membrane of the STS group appeared thinner than the control group (P < .05), with reduced calcium deposition than control and saline groups. Conclusions: Our results show that sodium thiosulfate has a preventive role in the development of myringosclerosis in the experimental animal model. Laryngoscope, 2010 [source]

A Potential Portal Flow in the Inner Ear,

THE LARYNGOSCOPE, Issue 2 2007
Morten Friis MD
Abstract Objectives/Hypothesis: The aim of the present study was to visualize the flow direction of blood in the extraosseous part of the vein of the vestibular aqueduct (VVA) and to explore the effect of an induced obstruction in the distal part of the VVA before it merges with the sigmoid sinus. The endolymphatic sac has been implicated as a potential endocrine gland, which venules drain to the VVA. A reversal of the direction of flow in the VVA toward the inner ear could, through vestibular arteriovenous anastomosis, cause portal circulation in the inner ear. Study Design: The authors conducted an experimental animal study using in vivo fluorescence microscopy. Results: Obstructing the distal part of the VVA just before it empties into the sigmoid sinus immediately reverses the flow of blood in the VVA toward the inner ear. Conclusions: After an obstruction of the VVA, the drained venous blood from the endolymphatic sac may enter a portal circulation in the inner ear, which could cause disturbances in the endolymph homeostasis and potentially symptoms as seen in Meniere disease. [source]

Microbubble-enriched lavage fluid for treatment of experimental peritonitis

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 4 2008
P. K. Sharma
Background: Relaparotomies and closed postoperative peritoneal lavage (CPPL) are performed to treat persistent peritonitis. This experimental animal study compared open abdominal lavage with CPPL, and evaluated the potential of microbubble-enriched lavage fluids to improve the efficiency of CPPL and reduce clinical morbidity, mortality and cost. Methods: Fluorescent polystyrene spheres were injected intraperitoneally into 22 male Wistar rats to simulate localized peritonitis. After 18 h the rats received open abdominal lavage and CPPL, with and without microbubbles. Microbubbles were obtained by adding ultrasound contrast agents to continuous ambulatory peritoneal dialysis fluid. Results: Open abdominal lavage was 3·5 times more effective in particle removal than CPPL, owing to better fluid dynamics. The introduction of air,liquid interfaces in the form of microbubbles made CPPL up to 2·4 times more effective than lavage without bubbles. Best detachment results were obtained when microbubbles with a flexible surfactant shell and longer blood elimination half-life were used. Conclusion: Open abdominal and CPPL lavage techniques are not efficient beyond a certain duration and volume as they do not cause bacterial detachment from the peritoneal membrane. Using surface tension forces from microbubbles significantly enhanced polystyrene particle detachment. These findings may have great consequences for the treatment of patients with peritonitis. Copyright © 2007 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]