ABSTRACT Purpose To evaluate the effect of light-emitting diode (LED) in an experimental model of radiodermatitis. Methods Ten male Wistar rats weighing 200–250 g were analyzed. Radiation was delivered in a single dose (20 Gy with Strontium-90 dermatological plaques), two areas per animal. After 15 days, they were divided into two groups: control group (n = 5) and LED group (n = 5), which was treated during 21 days later (LED 660 nm, 10 min in alternate days). The endpoints were radiodermatitis scale, histological analysis HE, Picrius Sirius and the gene expression of interleukin-10 (IL-10) and matrix metalloproteinase-9 (MMP-9). Results The LED group showed a higher number of dermal appendages (p = 0.04) and angiogenesis(p = 0.007), a tendency towards higher IL-10 (p = 0.06) and an increase in MMP-9 (p = 0.004) when compared to the control group. Conclusions This study suggested that the use of LED for radiodermatitis increased skin regeneration.
Abstract Purpose: To evaluate the hyaluronic acid (HA) inflammatory reaction, fibroblasts, fibrosis and duration of effect in the dorsal region of tobacco-exposed rats. Methods: Ten Wistar rats were divided into two groups: tobacco-exposed-group (TEG;n=5) and air-control-group (CG;n=5). The TEG animals were tobacco-exposed twice a day, 30-minutes/session, during 60 days. After this period, all animals received 0.1 mL HA subcutaneous injection in the dorsal area. The volume of HA was measured immediately after HA injection and weekly using a hand-caliper in nine weeks. After this period, all the animals were euthanized, and a specimen of was collected to evaluate inflammatory cells, fibroblasts, and fibrosis by HE. Results: This study showed a higher inflammatory reaction in TEG than CG: inflammatory cell-count (CG: 1.07±0.9; TEG: 8.61±0.36, p<0.001); fibroblast count (CG: 2.92±0.17; TEG: 19.14±0.62, p<0.001), and fibrosis quantification (CG: 2.0; TEG: 3.75, p<0.001). The analysis of the HA volume in nine weeks in the dorsal region did not show a difference between groups (p=0.39). Conclusions: This study suggested that the HA injection in the TEG caused an increase in inflammatory cell count, fibroblast, and fibrosis quantification when compared to the CG. There was no difference in the duration of effect of HA between the groups.
Abstract Purpose: To introduce a nonliving microvascular training model based on vessels diameter and feasibility. Methods: We dissected ten oxen tongues, and divided the pedicles into three-thirds: proximal, middle and distal. We measured the external vessels diameter in all regions. We performed a descriptive statistical analysis. Three students (two beginner level and one intermediate level) performed this training. We evaluated the confidence, according Likert scale. Results: We dissected all oxen tongues, each tongue showed two parallel pedicles. Each pedicle was located at 1.5 - 2.0 cm from the midline. Proximal median artery and vein diameter were 3.9 ± 0.7, and 5.04 ± 1.44mm, respectively. In the middle third, the mean artery diameter was 3.3 ± 0.4mm, and the vein diameter was 3.5 ± 0.9mm. The distal third showed a mean artery diameter of 2.0 ± 0.42mm, and a vein diameter of 2.4 ± 0.82mm. The students performed ten anastomoses. This study showed a higher confidence level (CL) (p=0.03) than the pre training CL assessment. Conclusion: This study suggested a feasible non-animal model for microsurgical training process for beginners and intermediate trainees.
ABSTRACT PURPOSE: To evaluate the effect of Botulinum Toxin A in different time of tobacco exposure. METHODS: 60 male, Wistar rats were divided into two tobacco exposure groups: a 2- month or a 4-month regimen. After this period, these two groups were subdivided as two: saline solution(SS) or botulinum toxin A(Bonta), at the time of the surgery. Seven days before the SS or Bonta injection, the animals were submitted to a random flap (3x10cm). On the seventh postoperative day, all animals were assessed for total flap area, viable area, and the viable/ total area ratio. RESULTS: This study showed a difference between groups 2-month saline vs. BontA injection (p=0.04); groups 4-month saline vs. BontA injection (p=0.001); groups 2-month saline vs. 4-month BontA (p=0.003), and, between groups 2- month BontA vs. 4-month saline(p=0.03). CONCLUSIONS: Botulinum Toxin A increased random flap viability in tobacco-exposed rats. Two months of tobacco exposure had the same effect as exposure for four months.
As conventional options for bone repair are not satisfactory, a new flap category was developed, the prefabricated flap (RPF). 42 metatarsic-I bone were obtained from 21 Wistar rats, and divided in two groups: group I (n=21) the bones were freeze- dryed and decalcified and group II (n=21) was frozen to - 70º C. After 3 weeks the bones were grafted in 21 rats, onto the left na right inferior epigastric vessels wrapped in silicon sheet. Groups I and II were subdivided in 3 groups each, following the period of permanence (1,2 or 4 weeks). In macroscopic histologic study, group I revealed loss of bone architecture and group II manteined its concistency and shape. In quantitative analysis, alterations were observed in group I, mainly inthe 2 weeks group. There is a histologic difference in prefabricated bone flaps betwenn groups I and II. Gradual bone reabsorption suggests that the flap should be rotated early. This study shows the applicability of homogenous bone for flap prefabrication.
As opções convencionais de tratamento de perdas ósseas, como enxertos e retalhos não são satisfatórias. Com isso uma nova categoria de retalhos, o retalho pré-fabricado (RPF), passou a ser estudada. Foram retirados 42 ossos metatársicos-I das patas traseiras de 21 ratos Wistar. O grupo I (n=21) foi descalcificado e liofilizado e o grupo II (n=21) foi não descalcificado e congelado a -70°C. Após 3 semanas os ossos foram enxertados em 21 animais sobre os vasos epigástricos inferiores nas regiões inguinal direita e esquerda, individualizados por uma lâmina de silicone. Os grupos I e II foram divididos em três subgrupos cada, de acordo com o tempo de permanência (1, 2 e 4 semanas) após a pré-fabricação do retalho. No estudo histológico macroscópico os grupos apresentaram diferenças em morfologia e consistência: o grupo I mostrou perda da arquitetura óssea e da rigidez e grupo II mantiveram sua forma, rigidez e consistência. Na análise qualitativa alterações foram observadas nos fragmentos do grupo desmineralizado e liofilizado, especialmente no subgrupo de 2 semanas. O grupo II não apresentou alteração no aspecto do tecido ósseo mineralizado entre os diversos subgrupos. É nítida a diferença histológica entre os RPF com osso descalcificado e liofilizado quando comparado ao não descalcificado e congelado. A reabsorção óssea gradual sugere que a rotação do retalho deve ocorrer precocemente. Este estudo demonstra a aplicabilidade do osso homógeno para pré-fabricação de retalhos.