Acta cirurgica brasileira最新文献

Purpose: To describe an experimental surgical model in rats using a dual-plane technique for evaluation of biomaterials in an in-vivo silicone implant coverage.

Methods: This study was developed following the ISO 10993-6 standard. In this study, 40 male Wistar rats weighing between 250 and 350 g were used, distributed into two groups: experimental, biomaterial superimposed on the minimammary prosthesis (MP); and control, MP without implantation of the biomaterial, with eight animals at each biological point: 1, 2, 4, 12, and 26 weeks. Thus, at the end of biological points (1, 2, 4, 12, and 26 weeks; n = 8 animals per week), the tissue specimens achieved were fixed in buffered formalin and stained with hematoxylin-eosin.

Results: Macroscopically, throughout the study, no postoperative complications were apparent. In the histological analysis, it was possible to observe the evolution of the inflammatory response, tissue repair, and fibrous capsule during the biological points.

Conclusions: The experimental model described in this study proved to be suitable for evaluating the biomaterial used in the coverage of breast silicone implants.

Purpose: Tamoxifen, a widely used drug for breast cancer treatment, is associated with adverse effects on the liver, including the development of fatty liver. This study aimed to investigate the potential protective effect of caffeine against tamoxifen-induced fatty liver in Wistar rats.

Methods: Rats were divided into normal control, tamoxifen + saline, and tamoxifen + caffeine. Plasma samples were assessed for biochemical markers related to oxidative stress, inflammation, liver function, and cell damage. Additionally, liver histopathology was examined to quantify the extent of fatty infiltration.

Results: In the tamoxifen + saline group, elevated levels of plasma malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), alanine aminotransferase (ALT), cytokeratin 18, and soluble ST2 were observed compared to the normal control group, indicating increased oxidative stress, inflammation, and liver injury (p < 0.01). Moreover, histopathological examination revealed a significant increase in fatty infiltration (p < 0.001). However, in the tamoxifen + caffeine group, these markers were markedly reduced (p < 0.05, p < 0.01), and fatty infiltration was significantly mitigated (p < 0.001).

Conclusions: The findings suggest that caffeine administration attenuates tamoxifen-induced fatty liver in rats by ameliorating oxidative stress, inflammation, liver injury, and cell damage. Histopathological evidence further supports the protective role of caffeine. This study highlights the potential of caffeine as a therapeutic intervention to counter tamoxifen-induced hepatic complications, contributing to the optimization of breast cancer treatment strategies.

Purpose: To examine whether isoflurane preconditioning (IsoP) has a protective effect against renal ischemia/reperfusion injury (I/RI) in diabetic conditions and to further clarify the underlying mechanisms.

Methods: Control and streptozotocin-induced diabetic rats were randomly assigned to five groups, as follows: normal sham, normal I/R, diabetic sham, diabetic I/R, and diabetic I/R + isoflurane. Renal I/RI was induced by clamping renal pedicle for 45 min followed by reperfusion for 24 h. IsoP was achieved by exposing the rats to 2% isoflurane for 30 min before vascular occlusion. Kidneys and blood were collected after reperfusion for further analysis. Renal histology, blood urea nitrogen, serum creatinine, oxidative stress, inflammatory cytokines, and renal cell apoptosis were assessed. Furthermore, the expression of brahma related gene 1 (Brg1), nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and nuclear factor-κB (NF-κB) were determined.

Results: Compared with control, diabetic rats undergoing I/R presented more severe renal injury, oxidative stress, inflammatory reaction, and apoptosis with the impairment of Brg1/Nrf2/HO-1 signaling. All these alterations were significantly attenuated by pretreatment with isoflurane.

Conclusions: These findings suggest that isoflurane could alleviate renal I/RI in diabetes, possibly through improving Brg1/Nrf2/HO-1 signaling.

Purpose: This work aimed to investigate the effects of Tanshinone IIA (Tan IIA) on myocardial cell (MC) apoptosis in a rat model of heart failure (HF).

Methods: Tan IIA was extracted from Salvia miltiorrhiza Bunge (SMB) using an ethanol reflux method. Fifty rats were randomly divided into five groups: sham (no treatment), mod (HF model establishment), low dose (LD: 0.1 mL/kg Tan IIA), medium dose (MD: 0.3 mL/kg Tan IIA), and high dose (HD: 0.5 mL/kg Tan IIA), with 10 rats in each group. The effects of different doses of Tan IIA on cardiac function, MC apoptosis, and the levels of proteins associated with the PI3K/Akt/mTOR signaling pathway were compared.

Results: Mod group showed a significant decrease in systolic arterial pressure, mean arterial pressure, heart rate, left ventricular systolic pressure, left ventricular ejection fraction, left ventricular fractional shortening, and the levels of p-PI3K, p-Akt, and p-mTOR proteins versus sham group (p < 0.05). Additionally, the left ventricular end-diastolic diameter (LVIDd), end-systolic diameter, diastolic pressure, and MC apoptosis were significantly increased (p < 0.05). LD, MD, and HD groups exhibited significant improvements across various indicators of cardiac function and MC apoptosis versus mod group (p < 0.05).

Conclusions: Tan IIA may improve cardiac function and inhibit MC apoptosis in rats with HF by modulating the PI3K/Akt/mTOR signaling pathway.

Purpose: To analyze clinical and endoscopic aspects of dyspeptic patients submitted to upper endoscopy in a reference center in the interior of Maranhão, Brazil.

Methods: Observational, descriptive, and analytical research through interviews and endoscopic reports of 80 patients with dyspeptic complaints submitted to upper endoscopy.

Results: Among the respondents, 66.25% were women, most were aged ≥ 40 years old and had epigastric pain as their main symptom, and 29.75% had no appropriate indication to perform upper endoscopy. Mild enanthematous gastritis of the antrum was the most frequent finding, and 92.5% had non-significant findings. Rapid urease test was positive in 25%. The following findings showed a statistically significant correlation (p < 0.05): age < 40 years old, female gender, and gastric lesion with positive urease test; smoking with gastric lesion and age less than 40 years old with normal examination. Patients with significant findings had appropriate indications for upper endoscopy.

Conclusions: The correct indication of upper endoscopy is essential for satisfactory endoscopic yields and accurate diagnosis.

Purpose: Napabucasin (NP) is a natural compound that can suppress cancer cell proliferation and cell cycle by inhibition of the signal transducer and activator of transcription 3 (STAT3) gene. We examined the effects of NP on the proliferation and invasion of neuroblastoma cells (SH-SY5Y).

Methods: Human neuroblastoma SH-SY5Y cell line was used in this study. NP was administered to groups at the doses of 0.3-1 µM. Cell viability was analyzed by MTT assay. Real-time quantitative reverse transcription polymerase chain reaction and western blot analysis assessed the expressions of interleukin (IL)-6 dependent Jak2/Stat3 signaling pathway. The MTT cell viability method was applied to determine the antagonistic-synergistic effects and inhibitory concentration (IC50) doses of doxorubicin (DX) and NP.

Results: It was determined that 0.3-1 µM doses of NP killed the cells almost completely after 48 hours, and also that Jak2/Stat3 expressions decreased dose-dependently via IL-6. At the protein level, NP and DX were found to reduce Jak2 and Stat3 levels.

Conclusions: NP showed that it suppresses the proliferation of neuroblastoma cells. Due to its inhibitory effect on Jak2 and Stat3, it can be used to prevent invasion of SH-SY5Y cells. NP, which can inactivate Jak2/Stat3, can be used as a treatment agent by combining with DX in proliferation pathway in neuroblastoma.

Purpose: Full-endoscopic spine surgery (FESS) is associated with specific complications, possibly linked to increased intracranial pressure (ICP) resulting from continuous saline infusion into the epidural space. This study aimed to assess the impact of saline irrigation and its correlation with noninvasively obtained ICP waveform changes.

Methods: Patients undergoing FESS between January 2019 and November 2020 were included. Noninvasive ICP (n-ICP) monitoring utilized an extracranial strain sensor generating ICP waveforms, from which parameters P2/P1 ratio and time to peak (TTP) values were derived and correlated to irrigation and vital parameters. Documentation occurred at specific surgical intervals (M0-preoperatively; M1 to M4-intraoperatively; M5-postoperatively). Mixed-model analysis of variance and multiple comparisons tests were applied, with M0 as the baseline.

Results: Among 31 enrolled patients, three experienced headaches unrelated to increased ICP at M5. The P2/P1 ratio and TTP decreased during surgery (p < 0.001 and p < 0.004, respectively). Compared to baseline, P2/P1 ratio and vital parameters remained significantly lower at M5. No significant differences were observed for fluid parameters throughout surgery.

Conclusions: This study demonstrated a decline in the n-ICP parameters after anesthetic induction despite the anticipated increase in ICP due to constant epidural irrigation. The n-ICP parameters behaved independently of fluid parameters, suggesting a potential protective effect of anesthesia.

Purpose: This study aimed to introduce and evaluate two new microvascular anastomosis techniques compared to the conventional method in a rat renal transplant model.

Methods: Using a Fisher-to-Lewis rat kidney transplantation model, the renal artery anastomosis was performed using the interrupted (I) suture technique, Y-shaped continuous (Y) suture technique, and anterior-interrupted and posterior-continuous (I-C) suture technique. The rats were then divided into three groups: I group, Y group, and I-C group. Parameters such as arterial anastomosis time, warm ischemia time, seven-day survival rate of the rats, and vessel histopathology were assessed.

Results: The mean arterial anastomosis time, blood leakage scores, and warm ischemia time were significantly reduced in groups Y and I-C compared to group I. Moreover, the seven-day survival rate was significantly higher in the I-C group compared to the other two groups. Arterial histopathology demonstrated vessel wall recovery without damage in all three groups, suggesting the safety of both Y and I-C techniques.

Conclusions: The anterior-interrupted and posterior-continuous suture method is particularly beneficial for small artery reconstruction in organ transplantation.

Purpose: To explore artificial intelligence's impact on surgical education, highlighting its advantages and challenges.

Methods: A comprehensive search across databases such as PubMed, Scopus, Scientific Electronic Library Online (SciELO), Embase, Web of Science, and Google Scholar was conducted to compile relevant studies.

Results: Artificial intelligence offers several advantages in surgical training. It enables highly realistic simulation environments for the safe practice of complex procedures. Artificial intelligence provides personalized real-time feedback, improving trainees' skills. It efficiently processes clinical data, enhancing diagnostics and surgical planning. Artificial intelligence-assisted surgeries promise precision and minimally invasive procedures. Challenges include data security, resistance to artificial intelligence adoption, and ethical considerations.

Conclusions: Stricter policies and regulatory compliance are needed for data privacy. Addressing surgeons' and educators' reluctance to embrace artificial intelligence is crucial. Integrating artificial intelligence into curricula and providing ongoing training are vital. Ethical, bioethical, and legal aspects surrounding artificial intelligence demand attention. Establishing clear ethical guidelines, ensuring transparency, and implementing supervision and accountability are essential. As artificial intelligence evolves in surgical training, research and development remain crucial. Future studies should explore artificial intelligence-driven personalized training and monitor ethical and legal regulations. In summary, artificial intelligence is shaping the future of general surgeons, offering advanced simulations, personalized feedback, and improved patient care. However, addressing data security, adoption resistance, and ethical concerns is vital. Adapting curricula and providing continuous training are essential to maximize artificial intelligence's potential, promoting ethical and safe surgery.

Purpose: To evaluate exogenous hyaluronic acid (HA) derived from bacterial fermentation through enteral and parenteral routes in ischemic skin flaps induced in rats, using clinical and histological exams; and interleukins (IL) as tissue inflammatory biomarkers.

Methods: Sixty-four male adults Wistar rats with ischemic skin flaps on the dorsum were randomized into four groups, based on the treatment protocol: subcutaneous administration of saline solution (0.9%) (GI); oral administration of distilled water (GII); subcutaneous administration of HA (0.3%) (GIII); and oral administration of HA (1%) (GIV). Flaps of all groups were comparable regarding clinical and macroscopic evaluation, histological examination, pro-inflammatory cytokines (IL-1β, IL-6, and tumor necrosis factor-α) and anti-inflammatory cytokine IL-10.

Results: A lower percentage of necrosis was identified in flaps treated with subcutaneous administration of HA (0.3%). The pro- and anti-inflammatory cytokines, epidermis thickness, blood vessels, and inflammatory cells showed statistically significant inter-group and intra-group differences (p < 0.05).

Conclusions: High molecular HA (1,400 ~ 2,000 kDa) administrated by subcutaneous or oral route exhibited beneficial effects in ischemic skin flaps of rats. However, subcutaneous administration of HA (0.3%) showed better results in terms of the percentage of necrosis and epithelialization.