Prevention of bone infection after open fracture using a chitosan with ciprofloxacin implant in animal model

Purpose To evaluate different concentrations of ciprofloxacin to prevent infection after open fracture contaminated with S. aureus in rats using absorbable local delivery system. Methods Fifty-two Wistar rats were assigned to six groups. After 4 weeks, all animals underwent 99mTc-ceftizoxima scintigraphy evaluation, callus formation measurement and histological analysis. ANOVA, t-Student and Kruskal Wallis were used for quantitative variables statistical analysis, whereas qui square and exact Fisher were used for qualitative variables. Results Treatment using 25% and 50% of ciprofloxacin incorporated at the fracture fixation device were effective in preventing bone infection compared to control group (p<0.05). Chitosan were not effective in preventing bone infection when used alone compared to control group (p>0.05). Histological findings demonstrated bone-healing delay with 50% of ciprofloxacin. No difference in callus formation were observed (p>0.05). Conclusion Local delivery treatment for contaminated open fracture using chitosan with ciprofloxacin is effective above 25%.(AU)

Influence of biomaterials on scintigraphic diagnosis of periprosthetic infections. Ceftizoxime-99m technetium model

Purpose: To compare the influence of two metallic implants in the diagnosis of periprosthetic infection using 99m technetium-labeled ceftizoxime.Methods: Twenty rats were randomly divided into four groups, which received sterile and contaminated titanium and stainless steel implants. After 3 weeks, scintilographic images were obtained using a gamma chamber. Radioactivity counts were obtained for the region of interest (ROI) on the operated and non-operated paws.Results: Groups A, B, and C showed homogenous distribution of the radiopharmaceutical. Hyper uptake was observed in the operated paw from group D. The ROI target count was higher in the two groups with stainless steel implants. Among the control groups, the count was higher in the stainless steel group. Furthermore, among the contaminated groups, the uptake was higher in the stainless steel group, with a significant difference. The target: non-target ratio was significantly lower in the control and contaminated groups with both titanium and stainless steel, but the comparison between control groups and contaminated groups was only significant in the former. The cpm/g observed after a decay of 48h showed statistically significant differences between groups.Conclusion: Different biomaterials used in implants have an influence on the results of scintigraphy with 99mTc-CFT.(AU)

Biomechanical study of the effect of platelet rich plasma on the treatment of medial collateral ligament lesion in rabbits

Purpose: To evaluate the use of platelet-rich plasma in the early stages of healing of traumatic injury of the medial collateral ligament in the knee of rabbits. Methods: Thirty rabbits were subjected to surgical lesion of the medial collateral ligament. Of these, 16 were treated with platelet-rich plasma and 14 with saline (control). After 3 and 6 weeks of treatment, 50% of the animals from each group were sacrificed, and biomechanical tests were performed on the injured ligament to compare the tensile strength between the two groups. Results: Platelet-rich plasma significantly increased the tensile strength of the ligament in the groups treated after3 and 6 weeks. In the group treated with platelet-rich plasma vs. saline, the tensile strength values were 3192.5 ± 189.7 g/f vs. 2851.1 ± 193.1 g/f at3 weeks (p = 0.005) and 5915.6 ± 832.0 g/f vs. 4187.6 ± 512.9 g/f at 6 weeks (p = 0.0001). Conclusion: The use of platelet-rich plasma at the injury site accelerated ligament healing in an animal model, demonstrated by an increase in the tensile strength of the medial collateral ligament.(AU)

Effects of the povidone-iodine (PVPI) in treatment of bacterial peritonitis induced in rats / Eficácia do polivinilpirrolidona-iodo (PVPI) no tratamento da peritonite bacteriana em ratos

PURPOSE: To evaluate the effectiveness of the use of the povidone-iodine (PVI) added to the liquid of wash of the peritoneal cavity in the reduction of bacterial absorption and in the remainder non-phagocyted bacteria in the circulating blood of rat. METHODS: Thirty four Wistar females rats were used, distributed in the following groups: A (n=10), non-treated; B (n=9), wash of the peritoneal cavity with solution of PVI to 1 percent in saline solution; C (n=15), wash of the cavity with saline solution. After anesthesia, it was made intraperitoneal infusion of solution of Escherichia coli labeled with 99mTc containing 10(8) CFU/ml. After 40 minutes, it was made the treatment, in the group A, manipulation of the viscera; in the group B, irrigation of the peritoneal cavity with warm solution of 1 percent PVPI to 37,5ºC, and in the group C irrigation with warm saline (37,5ºC). After 15 minutes of the treatment, blood samples and fragments of liver, spleen and lung was obtained for count of the radioactivity, and animals killed by abdominal aorta section. There were determined the bacterial absorption index and the remainder index in the bloodstream. RESULTS: Of the total of bacteria infused in the peritoneum, there was absorption of 0,92 percent (0,14 percent to 2,13 percent) in the animals of the group A (controls), 0,49 percent (0,18 percent to 0,71 percent) after use of topical PVPI (group B) and 0,80 percent (0,04 percent to 3,8 percent) after wash with saline solution (group C). There was significant reduction of the absorption when compared the treated animals with PVPI and the controls (p=0,003). Of the total of bacteria absorbed for the circulatory current, the percentile amount of bacteria non-phagocyted in the outlying blood was of 2,9 percent (1,1 percent to 17,7 percent) in the control group, 15,2 percent (8,3 percent to 21,4 percent) in those treated with PVPI (group B) and 6,9 percent (0,8 percent to 29,7 percent) after wash...(AU)

OBJETIVO: Avaliar a eficácia do uso do polivinilpirrolidona-iodo (PVPI) acrescido ao líquido de lavagem da cavidade peritoneal na redução da absorção bacteriana e no remanescente bacteriano não fagocitado no sangue periférico de ratos. MÉTODOS: Estudou-se 34 ratos Wistar fêmeas, distribuídos aleatoriamente nos seguintes grupos: controle (n=10), nenhum tratamento; PVPI (n=9), lavagem da cavidade peritoneal com solução de PVPI a 10 por cento em solução salina; salina (n=15), lavagem da cavidade com solução salina. Após anestesia, fez-se inoculação intraperitoneal de solução de Escherichia coli marcadas com 99mTc contendo 10(8) UFC/ml. Após 40 minutos, realizou-se o tratamento que foi, no grupo controle, manipulação das vísceras; no grupo PVPI, irrigação da cavidade peritoneal com solução de PVPI aquecido a 37,5ºC na concentração de 1 por cento, e no grupo salina irrigação com solução salina aquecida a 37,5ºC. Após 15 minutos do tratamento, os animais foram mortos por secção da aorta abdominal e colhidas amostras do sangue, do fígado, do baço e do pulmão para contagem da radioatividade. Foram determinados o índice de absorção bacteriano e o índice de remanescente no sangue periférico. RESULTADOS: Do total de bactérias inoculadas no peritôneo, houve absorção de 0,92 por cento (0,14 por cento a 2,13 por cento) nos animais do grupo controle, 0,49 por cento (0,18 por cento a 0,71 por cento) após uso do PVPI tópico e 0,80 por cento (0,04 por cento a 3,8 por cento) após lavagem com solução salina. Houve redução significativa da absorção quando comparados os animais tratados com o PVPI e os controles não tratados (p=0,03). Do total de bactérias absorvidas para a corrente circulatória, o percentual de bactérias não fagocitadas presentes no sangue periférico foi de 2,9 por cento (1,1 por cento a 17,7 por cento) nos animais controle 15,2 por cento (8,3 por cento a 21,4 por cento) naqueles tratados com PVPI e 6,9 por cento (0,8 por cento a 29,7 por...(AU)