Role of Nitrites in the Genesis of Adenocarcinoma Associated with Barrett's Esophagus

Background: Barrett's esophagus (BE) is one of the complications of gastroesophageal reflux disease (GERD) and a premalignant condition. It consists of a process of replacement of the squomous epithelium of the esophagus by intestinal columnar epithelium containing goblet cells, known as specialized intestinal metaplasia with goblet cells, and several factors have been related to its pathogenesis. The objective of this study! was to evaluate an experimental model of duodenogastroesophageal reflux and the effect of ingestion of sodium nitrite solution on the genesis of adenocarcinoma associated with Barrett's esophagus. Materials and Methods: Sixty male Wistar rats were divided into four groups. Twenty were not submitted to surgery and served as controls (10 animals ingesting only? water and 10 ingesting water plus a solution of sodium nitrite), while the remaining 40 animals were submitted to side-to-side duodenogastroesophageal anastomosis (20 animals ingesting only water and 20 ingesting water plus the sodium nitrite solution). The Vienna classification for dysplasia and adnocarcinoma was used in the analysis of results. Results: After 42 weeks of observation, Barrett Is esophagus was found in 26.3% (5119) of the animals submitted to surgery, that had not ingested nitrites compared to 72.3% (13118) of the animals in the group submitted to surgery and given nitrites. Six cases of adenocarcinoma (33.3%) were also found in this latter group. Barrett's esophagus was not found in an), of the animals that were not submitted to surgery. Categories 2, 3 and 5 of the Vienna classification were only found in the animals submitted to surgery that also received sodium nitrite (66.7%). Conclusion: The ingestion of sodium nitrite associated with duodenogastroesophageal reflux plays an important role in the genesis of adenocarcinoma associated with Barrett's esophagus.O TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE DEZEMBRO DE 2014.23691992

Changes in intestinal motility and in the myenteric plexus in a rat model of intestinal ischemia-reperfusion

Background/Purpose: Early histologic changes induced by intestinal ischemia-reperfusion injury (IIRI) have been extensively studied using animal models. However, information regarding late effects On intestinal motility is lacking. The aim of this study was to investigate the late effects of IIRI on myenteric plexus histology and intestinal motility. Materials and Methods: Thirty-two postweaning male mice weighing between 58 and 103 g were divided randomly into 4 groups: Control (unoperated), Sham (celiotomy), 30-minute ischemia (celiotomy and superior mesenteric artery ischemia for 30 minutes), and 45-minute ischemia (celiotomy and superior mesenteric artery ischemia for 45 minutes). Postoperative intestinal motility was assessed by weighing total fecal output for 24 hours on the 3rd, 7th, 14th, and 21st day after surgery. Segments of duodenum, jejunum, and ileum were examined at light microscopy for changes in the myenteric plexus. Results: Three weeks after IIRI, the ganglion cells from the myenteric plexus appeared in light microscopy, spongy or foamy, containing many vacuoles in their cytoplasm. The neuronal nucleus became irregular, with degenerative signs. These alterations did not occur among animals from the control or sham groups. Although the animals of the 45-minute ischemia group showed a significant drop in fecal output in the 21st postoperative day, this appeared to have no effect on weight gain. Conclusions: The results suggest that intestinal ischemia-reperfusion causes late neuronal damage. These changes resulted in alterations of intestinal motility, which, within the conditions of the present study, had no repercussion on general weight gain. (c) 2007 Elsevier Inc. All rights reserved.4261062106

Prostatic atrophy: Immunohistochemical study of hypoxia induced factors

Background: There is evidence that chronic local ischemia may be one possible etiology of prostatic atrophy (PA). Our aim was to study the expression of hypoxia induced factors in areas of PA. Design: The immunohistochemical expression of hypoxia-inducible factor-1 alpha (HIF-1) and vascular endothelial growth factor (VEGF) was studied in atrophic acini of 33 needle prostatic biopsies. Prostatic atrophy was the only diagnosis in these biopsies. For HIF-1 alpha, a total of 27,158, 10,060 and 9920 nuclei were counted in atrophic acini, acini with squamous metaplasia, and acini without squamous metaplasia surrounding acute infarct, respectively. For VEGF, a total of 24,966, 9849 and 9918 nuclei were counted for the same acini. A total of 1326 nuclei were counted in acini of the needle biopsy used as negative control. The Student's test for independent samples with significance level at 5% (p < 0.05) was used to compare the mean ratio (MR) of positive nuclei over total nuclei for HIF-1 and VEGF. Results: For HIF-1, 108 (MR = 0.004), 6877 (MR = 0.68), and 6566 (MR = 0.66) nuclei were positive in atrophic acini, acini with squamous metaplasia, and acini without squamous metaplasia surrounding acute infarct, respectively. There was a highly significant difference (p < 0.001) between atrophic acini and acini surrounding acute infarct. For VEGF, 139 (MR = 0.05), 5926 (MR = 0.60), and 4948 (MR = 0.50) nuclei were positive in the same acini. The difference was highly significant (p < 0.001). All 1326 nuclei counted in the needle biopsy with essentially normal findings were negative for HIF-1 and VEGF. Conclusions: This study showed that prostatic atrophic acini are not on acute ischemia. However, local chronic ischemia cannot be ruled out. Experimental data showed that on chronic ischemia, the signal triggering HIF-1 alpha accumulation may disappear despite continuous hypoxia suggesting that compensatory mechanisms triggered during prolonged hypoxia may be able to restore normal tissue oxygen levels.384173257758

Occurrence of Fat Embolism After Liposuction Surgery With or Without Lipografting An Experimental Study

Background: Liposuction in plastic surgery consists of the removal of excess fatty tissue in healthy individuals. In recent decades, this procedure has become more common worldwide. Associated with liposuction, lipografting has also been used for improving body contours, and has become known as liposculpture. Liposuction sometimes causes complications, including fat embolism, as described in the medical literature. The present study aims at ascertaining whether there is intravascular mobilization of fat after mechanical liposuction surgery and/or fat graft when carried out using one of the most common specific procedures used for liposuction, the superwet technique. Methods: A total of 30 Wistar rats were included in this study. Before the surgery, the animals were placed in the supine position and anesthetized with thiopental for 50 to 60 minutes, as it is generally performed in clinical practice. The animals were divided in the following 3 groups. Group A, consisting of 10 rats, served as controls, and were only anesthetized. Group B consisted of 10 rats, which underwent only liposuction. Group C also comprised 10 rats, which were liposuctioned and then lipografted in the dorsal region. Blood was collected just before and again, 48 hours after the procedure. After 48 hours, the animals were killed, and the lungs, kidneys, liver, and brain were histologically examined. Results: All the collected samples were analyzed microscopically with 2 different stains, namely, hematoxylin and eosin, and Sudan black. Fat particles were found in the lungs of 3 animals in group B (those that underwent only liposuction) and in 6 animals of group C (liposuction and lipografting). No fat particles were found in any organ of the control group. Conclusions: With this experiment, the authors showed that there is a risk of systemic mobilization of fat after liposuction surgery and that this risk is even higher when fat grafts are also carried out.67210110

Evaluation of Lateral Lymph Node Metastases in Advanced Distal Rectal Cancer

Background/Aims: The importance of lateral node dissection has not yet been fully investigated in advanced rectal cancer. To evaluate tumor cells in perirectal and lateral lymph nodes dissection from rectal adenocarcinomas considered free of disease by the hematoxylin-eosin test. Methodology: Fifteen patients submitted to neoadjuvant therapy and surgery for rectal adenocarcinoma with lateral node dissection were studied, retrospectively. The paraffin blocs of the nodes were analyzed with a immunohistochemical study and multiples cross section of the nodes. Results: A total of 331 lymph nodes from these 15 patients were assessed, distributed as 258 perirectal nodes, 73 non perirectal, and 27 lateral nodes. The average was 22,1 lymph nodes per patient. Three patients out of 15 (20%) with histological negative lateral lymph node had occult metastasis detected by pancytokeratins AE1 and AE3. One of these cases didn't present tumor in the surgical specimen of the rectum. A case of positive lateral node identified by hematoxylin-eosin was also identified by immunohistochemical study. Conclusions: Although we had a small number of patients in the present study, lateral node dissection is important in selected cases of advanced cancer. Pancytokeratins AE1 and AE3 had a potential to improve study for detection of occult node metastasis, being helpful in rectal cancer prognosis.5810413631366FAEPEX organisationUNICAMP organisatio