Manoel Roberto Maciel Trindade

Experimental model to induce obesity in rats

The etiology of obesity is multifactorial and is becoming a problem of public health, due to its increased prevalence and the consequent repercussion of its comorbidities on the health of the population. The great similarity and homology between the genomes of rodents and humans make these animal models a major tool to study conditions affecting humans, which can be simulated in rats. Obesity can be induced in animals by neuroendocrine, dietary or genetic changes. The most widely used models to induce obesity in rats are a lesion of the ventromedial hypothalamic nucleus (VMH) by administering monosodium glutamate or a direct electrical lesion, ovariectomy, feeding on hypercaloric diets and genetic manipulation for obesity.

Collagen in the transversalis fascia of patients with indirect inguinal hernia: a case-control study

BACKGROUND The aim of this study was to analyze the constituents of total and types I and III collagen fibers in the transversalis fascias of patients with indirect inguinal hernias, compared with samples removed from nonherniated cadavers. METHODS Biopsy samples from 26 patients and 26 cadavers were analyzed. Hematoxylin-eosin and picrosirius staining techniques were used. The images obtained were analyzed using a video morphometric technique to determine the constituents of total collagen and types I and III collagen in the transversalis fascia. The picrosirius-stained tissues were submitted to observation under polarized-light microscopy. RESULTS The results showed 17.3% less total collagen in patients with hernias compared with the control group (P < .01). Type I collagen in patients with indirect inguinal hernias was 23.7% less than the control group (P < .01), type III collagen was 6.4% less in the controls (P < .01). CONCLUSION The lower percentages of total collagen and type I collagen in the transversalis fascias of patients with indirect inguinal hernias could be a factor in hernia formation.

Fibroplasia after polypropylene mesh implantation for abdominal wall hernia repair in rats

PURPOSE This study assessed the collagen deposition and correlated it with local inflammatory responses to evaluate the length of time required for fibroplasia when polypropylene meshes are used to repair incisional abdominal wall hernias in rats. METHODS Thirty-six male Wistar rats underwent longitudinal resection of a peritoneal and musculoaponeurotic tissue segment (3x2 cm) of the abdominal wall followed by defect reconstruction with polypropylene mesh bridging over aponeurosis. The animals were divided into 6 groups according to the time points for the analysis of fibroplasia: 1, 2, 3, 7, 21 and 30 days post-implantation. Animals were sacrificed at each time point, and the site where the polypropylene mesh was implanted was evaluated histologically to assess inflammatory response and percentage of collagen using computer-assisted videomorphometry. RESULTS Total collagen was found at the mesh site on the 3rd day post-implantation, and increased progressively on all subsequent days up to the 21st day, when it reached its highest percentage (p<0.001). Type III collagen increased progressively from the 3rd to the 21st days, when it reached its highest percentage (p<0.001); on the 30th day, it decreased significantly (p>0.001). Type I collagen was first found between the 7th and 21st days; it reached its highest percentage on the 21st day and then remained stable until the 30th day. The type I to type III collagen ratio increased significantly and progressively up to the 30th day (p<0.001). Neutrophils were found at the mesh site from the 1st to the 21st day post-implantation. Macrophages, giant cells and lymphocytes were seen on the 2nd day. Thirty days after mesh implantation, neutrophils disappeared, but the percentages of macrophages, giant cells and lymphocytes remained stable (p<0.001). CONCLUSIONS This study showed that total collagen was first seen on the 3rd day post-implantation, with a higher percentage of type I collagen at the last observational time point. The prolonged healing inflammatory response and the persistence of chronic inflammation surrounding to the mesh did not affect the length of time required for fibroplasia.

Qualitative and quantitative evaluation of total and types I and III collagens in patients with ventral hernias

AimThe purpose of this study was to evaluate the amount of total and types I and III collagens of samples from the linea alba in patients with hernias (epigastric, umbilical, and incisional) on the anterior wall of the abdomen, comparing them to findings obtained from a cadaver control group without hernias.Materials and methodsSamples of the linea alba aponeurosis from 26 patients with hernias on the anterior abdominal wall and from 32 cadavers without hernias were analyzed and compared for qualitative and quantitative evaluation of the total and the types I and III collagens. Sirius-red staining was used to evaluate the total collagen, and for types I and III collagens, immunohistochemistry was used with monoclonal antibody anticollagen types I and III, respectively.ResultsThe amount of total collagen was 18.05% smaller in patients with hernias than in cadavers (p<0.05). Type I collagen was 20.50% smaller in patients than in cadavers (p<0.05). There was no significant difference in the amount of type III collagen between cases and controls (p=0.383).ConclusionThe results of this study indicate a relationship between hernias of the anterior abdominal wall and smaller amounts of total and type I collagens.

O colágeno em fáscia transversal de pacientes com hérnia inguinal direta submetidos à videolaparoscopia

PURPOSE: To analyse in respect to thickness, constitutive elements and total collagen quantification, samples of transversalis fascia from direct inguinal hernia patients, between twenty and sixty years of age and colected at the moment of laparoscopic repair, compairing with samples of the same tissue, obtained from corpse. METHODS: We collected 23 samples from patients and 22 samples from corpse. The samples were stained for Hematoxiline-eosine and Sirius-Red. The video captured images were analysed by computer-assisted videomorphometric techenic. RESULTS: We noticed the thickness of normal transversalis fascia to be 4.5 milimetres. Otherwise, the transversalis fascia from patients were 58 % thinner (p< 0.001). There was no evidence of any senile degenerative process involving the collagen fibres. The Dense connective tissue was the principal constitutive element in both groups being responsable for 75 % of controls fascia and 49 % for the hernia one (p< 0.001). The collagens mean percentual area in the sample field from patients were half the controls area (p< 0.001), stablishing that there are less collagen in the hernias wall. CONCLUSION: The direct inguinal hernia patients have less collagen in transversalis fascia either absolutely or relatively to other constitutional elements.

Determinants of body weight regulation in humans

Body weight is regulated by the ability of hypothalamic neurons to orchestrate behavioral, endocrine and autonomic responses via afferent and efferent pathways to the brainstem and the periphery. Weight maintenance requires a balance between energy intake and energy expenditure. Although several components that participate in energy homeostasis have been identified, there is a need to know in more detail their actions as well as their interactions with environmental and psychosocial factors in the development of human obesity. In this review, we examine the role of systemic mediators such as leptin, ghrelin and insulin, which act in the central nervous system by activating or inhibiting neuropeptide Y, Agouti-related peptide protein, melanocortin, transcript related to cocaine and amphetamine, and others. As a result, modifications in energy homeostasis occur through regulation of appetite and energy expenditure. We also examine compensatory changes in the circulating levels of several peripheral hormones after diet-induced weight loss.

Acute gastric dilatation and necrosis: a case report.

Abstract Massive gastric dilatation with necrosis and rupture is a very rare event. Here we describe the case of a 13-year-old girl with acute gastric dilatation, infarction, necrosis and perforation. It began with acute abdominal pain, but an absence of vomiting after eating a heavy meal. Laparotomy showed massive gastric dilatation with infarction and perforation. Early diagnosis is essential to reduce morbidity and mortality, and therefore treatment must be started promptly.

Melanoma metastasis to the spleen: Laparoscopic approach

We report a case of minimally invasive surgery in the management of metastasis to the spleen. A 67-year-old male patient with possible splenic soft tissue melanoma metastasis was referred to our hospital. He had a history of an excised soft tissue melanoma from his back eight months earlier, and the control abdominal computer tomography (CT) scan revealed a hypodense spleen lesion. The patient underwent laparoscopic surgery to diagnose and treat the splenic lesion. The splenectomy was performed and the histological examination revealed a melanoma. The patient had a good postoperative course and was discharged on the second postoperative day. On his 12-month follow-up there was no sign of recurrence. The laparoscopic approach is a safe and effective alternative for treatment of splenic metastases.

Comparação entre o uso de fio inabsorvível (polipropileno) e fio absorvível (poliglactina 910) na fixação de prótese de polipropileno em correção de defeitos músculo-aponeurótico da parede abdominal: estudo experimental em ratos

PURPOSE: The aim of this study is to assess fixation of a polypropylene mesh in the repair of incisional hernias comparing an absorbable (polyglactin 910) suture and an inabsorbable (polypropylene) one. METHODS: Eighty-one male rats of the Wistar breed, weighing from 180g to 220g, were submitted to a longitudinally resection of a musculoaponeurotic and peritoneal segment (3x2 cm) of the abdominal wall. Reconstruction was performed by reinforcement with polypropylene mesh, overlaid on the aponeurosis. They were distributed in two groups according to the thread used for mesh fixation as follows: (1) polyglactin 910 group, fixed with 8 stitches 4.0 Polyglactin 910 suture; and (2) Polipropylene group, fixed with 4.0 polypropylene suture. The skin suture was performed with 4.0 nylon continuous stitches. After 90 days, animals were sacrificed and submitted to macroscopic evaluation for the presence of hernias. Histologic samples were stained for Hematoxylin-Eosine and Sirius-Red and were assessed for signs of cicatrization such as chronic inflammatory reaction, fibrosis, suture absortion and percentage of fibrosis by computer-assisted video morfometric technic. RESULTS: There was no significant difference between the groups studied in relation to hernia formation (p=0,194). The histologic study showed significant increase of fibrotic reaction in the polipropylene group (p=0,0005), but this finding was not confirmed in the video-morfometric evaluation. Considering chronic inflammatory reaction, there was no difference between groups in relation to giant cells, lymphocytes and neutrophils. However, in the polipropylene group, macrophages were significantly increased (p=0,02). Polyglactin 910 has not been absorved 90 days after the procedure. CONCLUSIONS: The results of this study suggest that the fixation of polipropilene mesh is effective using absorbable sutures in the repair of ventral (incisional) hernias.

Effect of the oral administration of monosodium glutamate during pregnancy and breast-feeding in the offspring of pregnant Wistar rats.

PURPOSE Determine the effects of the MSG (monosodium glutamate) in the offspring of pregnant rats through the comparison of the weight, NAL (nasal-anal length) and IL (Index of Lee) at birth and with 21 days of life. METHODS Pregnant Wistar rats and their offspring were divided into 3 groups: GC, G10 and G20. Each of the groups received 0%, 10% and 20% of MSG, respectively from coupling until the end of the weaning period. RESULTS Neither weight nor NAL were different among the groups at birth. The group G20 at birth had an IL lower than the group GC (p<0,05) and with 21 days of life presented weight and NAL lower than the groups G10 and this lower than the GC (p<0,01). Otherwise the G20 at 21 days of life had the IL similar to the other two groups. The weight profit percentage from birth to the 21st day of life was lower in the G20 regarding the other two groups (p<0,01). The G20 had a NAL increase percentage from birth to the 21st day of life lower than the G10 and this lower than the GC (p<0,01). CONCLUSIONS MSG presented a dose-dependent relation in the variables weight and NAL. It caused a decrease in the growth pattern as well as in the weight gain pattern until the 21st day of life. The IL of the group 20% had an increased in relation to the control group after 3 weeks of follow up.