Acta cirurgica brasileira最新文献

Purpose: To investigate the active ingredients of walnut ointment (WO) and its mechanism in repairing wounds.

Methods: The ingredients of WO were detected by gas chromatography-mass spectrometry. The effect of linoleic acid (LA) was tested by in vitro Alamar Blue (AB) reagent. Image J software, histological and immunohistochemical analysis were used to confirm the healing effect of LA in the porcine skin model. The animals were euthanized after the experiment by injection of pentobarbital sodium.

Results: LA, 24% in WO, promotes keratinocytes and fibroblasts proliferation, which were 50.09% and 15.07% respectively higher than control (p < 0.05). The healing rate of the LA group (96.02% ± 2%, 98.58% ± 0.78%) was higher than the saline group (82.11% ± 3.37%, 88.72% ± 1.73%) at week 3 and week 4 (p < 0.05). The epidermal thickness of the LA was 0.16 ± 0.04 mm greater and the expression of the P63 and CK10 proteins was stronger in the LA group than the control (p < 0.05).

Conclusions: LA, which is the main components in WO can promote full-thickness burning wounds (FBWs) by stimulating cell proliferation and differentiation.

Purpose: Fluorescence spectroscopy techniques have been investigated aiming to reduce the invasiveness of methods for investigation of tissue. In transplantation procedures, it may offer the possibility of a complementary technique for the monitoring of liver grafts' conditions prior to and during the transplantation procedure stages involving cold perfusion. The objective of this study was to evaluate fluorescence spectroscopy under violet light excitation (408 nm) for the monitoring of clinical hypothermic liver transplantation procedures.

Methods: Organ grafts were monitored from before the removal of the donor's body to 1 h after the implant into the receptor's body. Fluorescence spectroscopy was assessed over five stages within these transplant stages.

Results: The study provided evidence of a correlation between fluorescence information collected during liver grafts transplantation and the survival of patients.

Conclusions: Fluorescence spectroscopy can become a tool to monitor transplantation grafts, providing objective information for the final decision of surgeons to use organs.

Purpose: The present study explored the role and mechanism involved in aprepitant-induced cardioprotective effects in rat model of ischemia-reperfusion injury.

Methods: The isolated hearts of Wistar male albino rats were subjected to ischemia-reperfusion injury on Langendorff apparatus. The extent of myocardial injury was assessed by measuring lactate dehydrogenase 1 and CK-MB release in the coronary effluent. The rats were treated with aprepitant (5, 10 and 20 mg/kg) before isolating hearts. After injury, the levels of HIF-1α, p-AkT, p-GSK-3β/GSK-3β were measured in heart homogenates. LY294002 was employed as PI3K inhibitor.

Results: Ischemia-reperfusion led to significant myocardial injury and decreased the levels of HIF-1α, p-AkT and ratio of p-GSK-3β/GSK-3β. Aprepitant attenuated myocardial injury and restored the biochemical changes in a dose-dependent manner. Pre-treatment with LY294002 (10 and 20 mg/kg) abolished aprepitant-mediated cardioprotective effects and restored the biochemical parameters in the heart homogenate.

Conclusions: Aprepitant may be effective in preventing ischemia-reperfusion-induced myocardial injury, which may be due to activation of PI3K-AkT-GSK-3β and HIF-1α signaling pathway.

Purpose: To evaluate a biofilm model of Pseudomonas aeruginosa in excisional cutaneous wound in mice.

Methods: Preclinical, translational study conducted with 64 C57BL/6 mice randomly assigned to control and intervention groups. Evaluation was on days D0, D3, D5, D7 and D10 of wound making. The profile of biofilm formation and induction was evaluated using wound closure kinetics, quantitative culture, and evaluation of wounds using transmission electron microscopy (TEM). Clinical evaluation was performed by liver tissue culture, weight variation, and quantification of leukocytes in peripheral blood. Analyses were performed with GraphPad Prism software.

Results: Bacterial load for induction of infection with P. aeruginosa and survival of animals was 104 UFC·mL-1. In D5 (p < 0.0001) and D7 (p < 0.01), animals in the intervention group showed a delay in the healing process and had their wounds covered by necrotic tissue until D10. Statistical differences were observed in wound cultures and weight at D5 and D7 (p < 0.01). Liver cultures and leukocyte quantification showed no statistical differences. No bacteria in planktonic or biofilm form were identified by TEM.

Conclusions: The findings raise questions about the understanding of the ease of formation and high occurrence of biofilm in chronic wounds.

Purpose: Negative pressure wound therapy (NPWT) has revolutionized wound care, but its high cost reduces the procedure's availability. To solve the problem, streamlined vacuum dressings systems have been proposed, but the utility of these devices has been poorly studied. The objective of this study was to evaluate a simplified vacuum dressing system model (SVDM).

Methods: Randomized clinical trial in which wounds were treated with SVDM compared to a complex occlusive dressing (silver hydrofiber, SHF). The analyzed outcomes were cleaning, presence of granulation tissue, clinical appearance, and indication for surgical closure of wounds.

Results: Fifty injuries were treated (25 in each group), most located on lower limbs. SVDM proved to be more effective than SHF in the evaluated outcomes. Wound recalcitrance reduced the effectiveness of the equipment used. Despite its efficacy, complications occurred, the most frequent related to dressing changes: minor bleeding, foam adherence to a wound bed, and pain. Only for bleeding no favorable risk-benefit ratio was found. There were no severe complications, worsening conditions of injuries, or deaths.

Conclusions: SVDM proved to be an effective and acceptably safe device for managing studied wounds.

Purpose: This study aimed to develop a minimally invasive surgical procedure for laminar lift and posterior cervical laminoplasty via the intermuscular approach using a canine model.

Methods: Six Alaskan dogs were used for developing the surgical approach. The bilateral laminae of C3-7 were cut with an ultrasonic osteotome and fixed with bilateral plates to maintain the lamina lifting and reshape a wider spinal canal. The important structures, such as ligaments, supraspinous ligaments, interspinous ligaments, and ligamentum flavum were preserved. The therapeutic effect was evaluated by preoperative and postoperative imaging results and neck mobility.

Results: The surgical procedures were all successfully performed in the 6 animals. All the dogs survived well within 1 year of postoperative follow-up. The postoperative neck mobility was as good as the preoperative one. Computed tomography results showed that the anteroposterior diameter of the spinal canal was successfully enlarged and maintained well.

Conclusions: The minimally invasive surgical procedure for laminar lift and posterior cervical laminoplasty via the intermuscular approach was feasible in a canine model, which might be applied in clinical practice.

Purpose: To evaluate the effect of preoperative intravenous chemotherapy with 5-fluorouracil on liver regeneration in an experimental model of major hepatectomy in rats.

Methods: Wistar rats were divided into two groups of 20 animals each and submitted to 70% hepatectomy 24 h after intravenous injection of 5-fluorouracil 20 mg/kg (fluorouracil group, FG) or 0.9% saline (control group, CG). After hepatectomy, each group was subdivided into two subgroups of 10 animals each according to the day of sacrifice (24 h or 7 days). Liver weight during regeneration, liver regeneration rate using Kwon formula, and the immunohistochemical markers proliferating cell nuclear antigen (PCNA) and Ki-67 were used to assess liver regeneration.

Results: At early phase (24 h after hepatectomy) it was demonstrated the negative effect of 5-fluorouracil on liver regeneration when assessed by Kwon formula (p < 0.0001), PCNA analysis (p = 0.02). With regeneration process complete (7 days), it was possible to demonstrate the sustained impairment of chemotherapy with 5-fluorouracil on hepatocytes regeneration phenomenon when measured by Kwon formula (p = 0.009), PCNA analysis (p = 0.0001) and Ki-67 analysis (0.001).

Conclusions: Preoperative chemotherapy with intravenous 5-fluorouracil negatively affected the mechanisms of liver regeneration after major hepatectomy in rats.

Purpose: Hancornia speciosa latex has shown pharmacological potential in wound healing processes due to its angiogenic, osteogenic, and anti-inflammatory activities. The aims of this study were to carry out a cream-gel formulation with 5, 10 and 25% of H. speciosa serum latex and to evaluate its potential to stimulate the skin regeneration in rats' wounds.

Methods: One hundred and twenty rats were divided into five groups: neutral control with saline (G1), cream-gel based on H. speciosa latex serum at 5% m/v (G2), cream-gel at 15% m/v (G3), cream-gel at 25% m/v (G4), and cream-gel (G5). The animals were euthanized at three, seven, 14 and 21 days after the injury induction, and some parameters were analyzed: wound contraction, necrosis, fibrin, polymorphonuclear and mononuclear infiltrates, fibroblast, angiogenesis, hemorrhage, and collagen.

Results: The therapeutic treatment with cream-gel at 15 and 25% is beneficial in the inflammatory phase of healing processes since it increased the angiogenesis and proliferation of mononuclear infiltrations in wounds. Regarding wound contraction, the treatment with cream-gel (5 and 15%) induced a higher rate of contraction in the proliferative phase. The 15% cream-gel formulation stimulated a greater production of collagen in the injured tissues.

Conclusions: H. speciosa cream-gel is a low-cost herbal medicine which can aid in tissue repair.

Purpose: To describe the microsurgical anatomical aspects of the extratemporal facial nerve of Wistar rats under a high-definition video system.

Methods: Ten male Wistar rats (12-15 weeks old), without veterinary diseases, weighing 220-280 g, were used in this study. All animals in this study were submitted to the same protocol and by the same surgeon. A 10-mm incision was made below the bony prominence of the right or left ear, and extended towards the angle of the mandible. The dissection was performed and the main branches of the facial nerve were dissected.

Results: The main trunk of the facial nerve has a length of 0.88 ± 0.10 mm and a length of 3.81 ± 1.03 mm, measured from its emergence from the stylomastoid foramen to its bifurcation. Seven branches originating from the facial nerve were identified: posterior auricular, posterior cervical, cervical, mandibular, buccal, temporal, and zygomatic.

Conclusions: The anatomy of the facial nerve is comparable to that of humans, with some variations. The most observed anatomical division was the distribution in posterior auricular, posterior cervical, cervical, mandibular, buccal, temporal, and zygomatic branches. There is no statistical difference between the thickness and distance of the structures compared to the contralateral side.

Purpose: To analyze the cytotoxicity and cell in porcine-derived decellularized skin matrix.

Methods: We analyzed the effect of multiple decellularization processes by histological analysis, DNA quantification, and flow cytometry. Subsequently, we analyzed the most appropriate hydrogel concentration to minimize cytotoxicity on fibroblast culture and to maximize cell proliferation.

Results: After the fourth decellularization, the DNA quantification showed the lowest DNA concentration (< 50 ng/mg). Histological analysis showed no cell components in the hydrogel. Moreover, hematoxylin and eosin showed a heterogeneous structure of collagen fibers. The best hydrogel concentration ranged from 3 to 25%, and there was no significant difference between the 24 hours and seven days.

Conclusions: The process of hydrogel production was effective for removing cells and DNA elements. The best hydrogel concentration ranged from 3 to 25%.