O cultivo de Caiman yacare demanda grandes gastos com alimentação, deste modo, é necessário formular dietas mais baratas e mais eficientes para a engorda destes animais. Uma possibilidade de redução nos custos é o acréscimo de lipídeos de origem vegetal. Neste trabalho, analisou-se o processo de absorção de óleo de soja pelo intestino de Caiman yacare para avaliar possíveis alterações patológicas pelo uso deste óleo na mucosa intestinal de um animal carnívoro. A absorção de óleo de soja ocorreu massiçamente pelo intestino delgado, gerando esteatose intestinal temporária e formando quilomícrons pequenas, que foram transportadas pelo sistema linfático. Outros parâmetros que indicam ausência de patologias na mucosa intestinal, como alteração na proliferação celular, lesão tecidual, recrutamento de granulócitos, formação de heterófilos tóxicos e degranulação de mastócitos, não foram alterados, indicando o potencial uso de óleo de soja na dieta de Caiman yacare. / Cultivation of Caiman yacare demands large financial expenditures on food, so it is desirable to reduce costs by formulating cheaper and more efficient feedings. The soybean oil addition in the diet is an opportunity to reduce spending, but very little is known about the effects of vegetable-origin oils in this carnivore species health. Here we describe the process of soybean oil absorption by the intestine of Cayman yacare in order to evaluate possible intestinal pathologies caused by the soybean oil. Soybean oil absorption occurred massively across the intestine, caused temporary intestinal steatosis and produced small-sized chylomicrons that were carried away from the intestine by the lymphatics. Some mucosal integrity parameters analyzed such as enterocyte proliferation, epithelial damage, granulocyte recruitment, toxic heterophil formation and mast cell degranulation were not altered, suggesting soybean oil may potentially be used in Caiman yacare feedings.

Parasitische Nematoden beeinflussen gezielt die Abwehrreaktionen ihres Wirtes. Dies wird besonders während der chronischen Infektionsphase durch eine herabregulierte T-Zell-Antwort auf Parasitenantigene und andere Stimuli ersichtlich. In dieser Arbeit wurde die T-Zell-Antwort gegen einen intestinalen Nematoden untersucht. Mäuse wurden mit dem Trichostrongyliden Heligmosomoides polygyrus infiziert und in der Folge Effektor- sowie regulatorische T-Zellen (Tregs) untersucht. Subpopulationen von CD4+ T-Zellen wurden aus chronisch infizierten Mäusen isoliert und in naive Empfänger transferiert, welche nachfolgend infiziert wurden. Dabei zeigte sich, dass der Transfer von CD4+ Effektor-T-Zellen zu einer verminderten Wurmlast in den Empfängertieren führte, diese Zellen also einen partiellen Schutz gegen die Primärinfektion vermitteln. Der gleichzeitige Transfer von Tregs beeinflusste diesen Effekt nicht. Tregs allein zeigten keinerlei Einfluss auf die Wurmlast der Empfänger. Die Protektion durch Transfer von Effektor-T-Zellen kann vermutlich auf eine kleine Antigen-spezifische Population von CD4+ Zellen zurückgeführt werden. Diese Zellen wurden durch die Expression von CD40-L (CD154) nach Restimulation mit Parasitenantigen in vitro charakterisiert und enthielten einen Großteil der Zytokinproduzenten unter den CD4+ Zellen. Während diese Effektorzellen ein deutliches Th2-Zytokinprofil durch Produktion von Interleukin-4 (IL-4) und IL-13 zeigten, reagierte eine Treg-Subpopulation mit der Sekretion hoher Mengen von IL-10 auf Antigenstimulation. Diese Tregs waren durch Expression des Integrins AlphaE (CD103)Beta7 sowie CD25 und Foxp3 charakterisiert und vermittelten in vitro die stärkste Suppression anderer T-Zellen, wenn sie aus chronisch infizierten Mäusen isoliert wurden. Durch Untersuchung der zellulären Zusammensetzung von mesenterialen Lymphknoten und Milz konnte gezeigt werden, dass die Frequenz solcher regulatorischer Zellen im Verlauf der Infektion dauerhaft und überproportional zunimmt. Im Gegensatz dazu wurde am Infektionsort nur eine vorübergehende Akkumulation von Tregs (Foxp3+) während der akuten Phase der Infektion nachgewiesen. Diese Ergebnisse zeigen den Einfluss einer intestinalen Nematodeninfektion auf die Aktivität von Tregs und das Potential parasitenspezifischer CD4+ Effektor-Zellen zur Vermittlung von Schutz gegen die Infektion. Ein weiteres Projekt dieser Arbeit wahr die Verabreichung eines immunmodulatorischen Parasitenproteins, des Filariencystatins Av17, in einem Mausmodell entzündlicher Darmerkrankungen. In Mäusen wurde eine kolitisartige Entzündung durch eine Chemikalie im Trinkwasser induziert. Die regelmäßige Verabreichung von rekombinant exprimiertem Cystatin verminderte die Entzündungsreaktion signifikant. Damit konnte in dieser Arbeit gezeigt werden. dass Entzündungsreaktionen, die nicht durch den Parasiten selbst hervorgerufen werden, durch die Applikation einer einzelnen Parasitenkomponente unterdrückt werden können. / Parasitic nematodes specifically modulate the immune response of their hosts. A cellular hyperreactivity, especially during the chronic phase of infection, is a distinct finding of such infections. The T cell response against an intestinal nematode was analyzed in this work. Mice were infected with the trichostrongylid Heligmosomoides polygyrus and surveyed for changes concerning effector and regulatory T cells (Tregs). Subpopulations of CD4+ T cells were isolated from chronically infected mice and adoptively transferred to naive recipients, which were subsequently infected. The Transfer of CD4+ effector cells conferred partial protection, seen as decreased worm burdens in recipients. This effect was unimpaired by simultaneous transfer of Tregs. The transfer of purified Tregs alone showed no effect on worm burdens. The protection by transfer of effector T cells was probably due to a small parasite-specific population, which was characterized by the expression of CD40-L (CD154) after antigen-restimulation. The CD154+ population contained high frequencies of cells reacting with production of the Th2 key cytokines interleukin-4 (IL-4) and IL-13. On the other hand, a subpopulation of Tregs secreted high amounts of IL-10 in response to the antigen. These Tregs were characterized by the expression of the integrin AlphaE (CD103)Beta7, as well as CD25 and Foxp3. They showed a peculiar strong suppressive efficacy on the proliferation of other T cells, especially when derived from chronically infected donors. Analyzing the cellular composition of mesenteric lymph nodes and spleens in response revealed a lasting and over-proportional increase in frequencies of these Tregs. In clear contrast, only a transient increase of Foxp3-expressing Tregs was detected at the site of infection during the acute phase. These results point out the changes Treg activity during an intestinal nematode infection and show the potential of CD4+ effector cells in mediating protection against infection. A second project of this work was the application of an immunomodulatory parasite protein, the filarial cystatin Av17, in a mouse model of inflammatory bowel disease. Mice developed an inflammatory response to a chemical applied in the drinking water. The repeated application of recombinantly expressed cystatin significantly diminished the inflammatory response. Hence, this work showed the potential of a single parasite component in suppressing inflammatory processes not caused by the parasite itself.

A lesão de isquemia/reperfusão(I/R) do intestino delgado é de importância fundamental em procedimentos cirúrgicos. Alguns radicais livres de oxigênio gerados atuam durante este período. Utilizamos o ácido ascórbico para atenuar as lesões de I/R. Cinqüenta ratos foram separados e cinco grupos, cada grupo com 10 ratos. Os grupos foram sumetidos à isquemia mesentérica e isquemia/reperfusão. Os grupos experimentos receberam ácido ascórbico. Foi realizada a análise histológica morfométrica. Os grupos com ácido ascórbico mostraram uma redução significativa do infarto anti-mesentérico. (p = 0,009) na isquemia/reperfusão e redução da necrose das vilosidades na isquemia. O ácido ascórbico é eficaz na redução dos danos intestinais causados pela I/R em ratos / Intestinal injury resulting from ischemia-reperfusion (I/R) is of fundamental importance in surgical procedures. Some oxygen-derived free radicals generated during this time possibly play an important role. We used ascorbic acid to attenuate I/R injury. Fifty male rats were divided into five groups, each containing 10 rats. The groups were submitted to mesenteric ischemia and ischemia/reperfusion, experimental groups received ascorbic acid. The intestinal histological morphometric analysis was performed. The ascorbic acid groups showed a significant reduction of antimesenteric villous infarct (p=0,009) in the /R and reduction of villous necrosis ischemia groups. The ascorbic acid is effective in reducing the intestinal damage caused by I/R in the rats

Die Tyrosin Kinase Brk stellt den Prototypen nicht N-terminal myristoylierter, Nicht-Rezeptor Tyrosin Kinasen dar. Die Expression dieser Kinase ist auf epitheliale Gewebe beschränkt und wird während der Entwicklung differentiell reguliert. In normalen Geweben ist die Brk Expression auf nichtproliferierende, terminal differenzierte Zellen beschränkt. Um die regulatorische Funktion von Brk im murinen Darmepithel zu untersuchen, wurde das brk Gen in der Maus inaktiviert. Brk knockout Mäuse zeigten keine offensichtlichen Defekte in ihrer Entwicklung jedoch eine erweiterte Proliferationszone in den Krypten des Darmepithels und verlängerte Villi. Die Inaktivierung von Brk führte zu einer erhöhten Akkummulation von nukleärem (-catenin sowie einer Hochregulierung des (-catenin Zielgens c-myc in den Krypten der knockout Mäuse. Zusätzlich zeigten Brk knockout Mäuse eine Aktivierung des Akt-Signaltransduktionswegs in ihrem Darmepithel. Im Gegensatz zu Wildtyp Mäusen waren Brk knockout Mäuse resistent gegenüber (-Strahlung, was die Anhäufung onkogener Mutationen und damit die Entwicklung von Krebs fördert. Eine Induktion der Expression des Brk-Proteins im Darmepithel behandelter Wildtyp Mäuse wurde festgestellt. Weiterhin traten bei Brk knockout Mäusen chronische Entzündungen des Darmepithels sowie eine erhöhte Sensibilität gegenüber dem Reizmittel DSS auf. Im Gegensatz dazu, zeigten Wildtyp Mäuse eine mit der Literatur Übereinstimmende Reaktion zu DSS verbunden mit einer Induktion der Brk Expression im Darmepithel. Zusammenfassend kann gesagt werden, dass die Brk Tyrosin Kinase eine entscheidende Rolle in der Aufrechterhaltung der Homöstase und Integrität des Darmepithels spielt. Insbesondere scheint Brk als wichtiger Faktor zur Bestimmung der Sensitivität epithelialer Zellen zu genotoxischem Stress zu fungieren. Entgegen der bisher vermuteten onkogenen Funktion in epithelialen Tumoren scheint Brk im normalen Darmepithel "Tumor Suppressor" Ähnliche Funtionen innezuhaben. / The Breast tumor kinase Brk is a prototypical non-myristoylated, non-receptor tyrosine kinase. Brk expression is epithelial-specific and ,in normal tissues, restricted to cells exiting the cell cycle and undergoing terminal differentiation. To determine the biological role of Brk in the gastrointestinal tract, we disrupted mouse brk by homologous recombination. Loss of Brk in the mouse resulted in increased intestinal epithelial cell turnover and the appearance of longer small intestinal villi. Brk deficient mice displayed enhanced accumulation of nuclear (-catenin and upregulation of the (-catenin target gene c-myc in the crypt compartment of small and large intestine. In addition, Brk deficient mice exhibited increased Akt kinase activity. Even though, there was no corresponding difference in base-line apoptosis in untreated wild-type and knockout animals. However, subjected to (-irradiation, Brk deficient animals were significantly impaired in the apoptotic response. Wild-type mice, however, exhibited normal levels of apoptosis following (-irradiation accompanied by a rapid induction of Brk expression in crypt cells. Furthermore, chronic inflammation was observed in Brk deficient mice, and they showed increased susceptibility to a colon injury model utilizing DSS. Interestingly, wild-type mice exhibited a significant upregulation of nuclear Brk protein throughout the intestinal epithelium in response to DSS. These recent findings suggest that Brk plays a crucial role in the maintenance of intestinal tissue homeostasis and integrity. In addition, Brk may function to protect the intestinal epithelium against DNA-replication-induced errors and hence the development of cancer. Contrary to reported oncogenic properties of Brk in other epithelial tissues, Brk appears to have tumor suppressor-like functions in the mouse gastrointestinal epithelium.

In der vorliegenden Arbeit wurde die Bedeutung von intraepithelialen Lymphozyten (IEL), oxidativem Streß und endogenen Schutzmechanismen bei GvHR, Dünndarmtransplantation, Sepsis, Morbus Crohn sowie intestinalem Ischämie/Reperfusionsschaden (I/RS) analysiert. Die Bestimmung der phänotypischen und funktionellen Charaktistika der IEL im Rahmen der o. g. Erkrankungen wies auf eine Selektion bestimmter T-Zell Subpopulationen in der Darmschleimhaut hin. Zusätzlich konnte gezeigt werden, daß IEL nicht nur als Effektorzellen zur mukosalen Barrierefunktion beitragen, sondern auch regulierende Funktionen bei weiteren Abwehrmechanismen der Darmschleimhaut, wie z.B. der NOS-2 Expression besitzen. Die Untersuchungen zum intestinalen I/RS zeigten eine Gewebeschädigung nicht nur im Darm sondern auch der Leber nach selektiver intestinaler Ischämie. Dabei konnte in beiden Organen oxidativer Streß als ein Faktor der Gewebeschädigung nachgewiesen werden. Bei der Modulation des I/RS durch Gabe von Zytokinen konnte eine Zunahme des I/RS durch Gabe von IL-10 und eine Abnahme des I/RS durch IL-2 erreicht werden. Der positive Effekt der IL-2 Gabe war von einer verstärkten und verlängerten NOS-2 mRNA Expression sowie einer gesteigerten NO-Freisetzung begleitet. Im Gegensatz dazu fehlte nach IL-10 Gabe die Zunahme der NOS-2 Epxression ebenso wie ein Anstieg der NO-Metabolite im Serum. Die verminderte NO-Produktion könnte somit den negativen Effekt des anti-inflammatorischen IL-10 auf den I/RS erklären. / In this study, the role of intraepithelial lymphocytes (IEL) was analyzed in Graft-versus-Host disease, small bowel transplantation, sepsis and inflammatory bowel disease. Furthermore, the influence of oxidative stress and endogenous protective mechanisms on the development of intestinal ischemia/reperfusion injury was determined. The phenotypic and functional characteristics of IEL in these diseases indicated that only specific T-cell subsets selectively migrate and/or survive in the intestinal mucosa. In addition, it was demonstrated that IEL display several functions in the intestinal barrier system: they are cytolytic effector cells, but do also exert regulatory functions on the expression of mucosal host defense mechanisms such as NOS-2 expression. The investigations on intestinal ischemia / reperfusion injury revealed that selective intestinal ischemia induces tissue injury not only in the intestine, but in the liver as well. In both organs, oxidative stress plays a predominant role in the development of tissue destruction. Modulation of I/RS by administration of cytokines lead to increased tissue damage after IL-10 administration and reduced tissue injury after IL-2 administration. The beneficial effect of IL-2 may have been due to an increased NOS-2 mRNA expression and the subsequently increased NO production. In contrast, IL-10 administration failed to induce an increased NOS-2 mRNA expression or NO production in the intestine and liver.

As doenças inflamatórias intestinais são caracterizadas por uma desregulação na resposta imune contra a microbiota. O zebrafish, tem emergido como um novo modelo para o estudo de doenças inflamatórias. Os ácidos graxos de cadeia curta (AGCCs) são produtos da microbiota intestinal, que possuem papéis antiinflamatórios e aparecem como uma das possíveis terapias contra doenças inflamatórias. A implementação do modelo de inflamação intestinal induzido pelo ácido trinitrobenzenesulfônico (TNBS) em larvas de zebrafish aumentou a mortalidade de forma dose-dependente. Se observou dilatação do lúmen com alisamento das vilosidades intestinais. Não se detectaram mudanças na produção de muco nem no número de células caliciformes mas teve um leve aumento da apoptóse e diminuição da proliferação, nos expostos ao TNBS. Teve aumento de células mielóides infiltrantes e de citocinas inflamatórias, assim como disbiose da microbiota. O tratamento com AGCCs gero alta mortalidade a concentrações acima de 10 mM, mas existe ação anti-inflamatória a esta mesma concentração. / Inflammatory bowel diseases are characterized by a dysregulation in immune response against microbiota. The zebrafish has emerged as a new model for the study of inflammatory diseases. Short chain fatty acids (SCFAs) are products of the intestinal microflora, which have anti-inflammatory roles and appear as a possible therapy against inflammatory diseases. The implementation of intestinal inflammation model induced by trinitrobencenesulfonic acid (TNBS) in zebrafish larvae, increased mortality in a dose-dependent manner. Was observe dilatation lumen and straightening of the intestinal villi. No changes were detected in the production of mucus or in the number of goblet cells but had a slight increase in apoptosis and decreased proliferation in exposed to TNBS. Also has, increased cytokines and infiltrating myeloid cells, and dysbiosis of the microbiota. Treatment with SCFAs generate high mortality above 10 mM concentrations, but there anti-inflammatory action to this same concentration.

Introdução: Pacientes com Polipose Adenomatosa Familiar (PAF) tem maior risco de desenvolvimento de carcinoma duodenal em comparação com a população em geral, sendo a classificação de Spigelman adotada como método de estadiamento da adenomatose duodenal em doentes com PAF. No entanto, a relação entre a gravidade da polipose duodenal e variáveis clínicas não é bem compreendida. Objetivos: 1) Avaliar, através do método endoscópico, a prevalência e a intensidade da adenomatose duodenojejunal em pacientes com PAF em nosso meio. 2) Verificar a associação de variáveis clínicas, com a gravidade fenotípica da adenomatose duodenal e ampular. Metodologia: Foram estudados prospectivamente, 62 pacientes com diagnóstico de PAF, atendidos no Ambulatório de Poliposes Intestinais do Departamento de Gastroenterologia do Hospital das Clínicas da Universidade de São Paulo. Os pacientes foram submetidos à duodenoscopia, classificados segundo Spigelman e a presença ou não de adenomas ampulares. Os pacientes foram distribuídos em dois grupos: Estadio de Spigelman de 0 a II, e Estadio III e IV. Estes grupos foram relacionados com variáveis clínicas, tais quais: sexo, idade, antecedentes familiares positivos de PAF, tipo de cirurgia do cólon, e tipo de polipose colônica. Naqueles pacientes classificados como Spigelman III e IV foi realizada enteroscopia assistida por balão via anterógrada para avaliação do jejuno. Resultados: Quarenta e nove pacientes foram classificados como estadios de Spigelman 0, I ou II, e 13 pacientes como estadios III ou IV. A análise da correlação destes grupos foi estatisticamente significativa com a variável história familiar (p = 0,03). Naquelas famílias que apresentaram vários parentes inclusos neste estudo, observou-se estadio de Spigelman similar entre os diferentes parentes de cada família. Sete pacientes apresentaram adenomas menores da papila duodenal. A associação da presença de adenoma de papila com a variável manifestações extraintestinais (p= 0,009) foi estatisticamente significante na análise multivariável. Enteroscopia assistida por balão foi realizada em 12 pacientes, dos quais 10 apresentaram adenomas tubulares com displasia de baixo grau no jejuno proximal. Conclusões: 1. A prevalência da adenomatose duodenal avançada e de adenomas ampulares é clinicamente significativa na PAF em nosso meio. 2. A prevalência de adenomas jejunais em pacientes com adenomatose duodenal avançada é alta, apesar de não serem lesões clinicamente significativas. No entanto, enteroscopia deve ser indicada de forma individualizada em casos de polipose duodenal avançada na avaliação da extensão do acometimento jejunal. 3. A intensidade da adenomatose duodenal pode ser previsível a partir da gravidade da adenomatose duodenal de algum parente de primeiro grau. 4. A presença de manifestações extracolônicas reforça a necessidade de avaliação da região da papila de Vater, desde que houve associação independente entre a presença de adenomas ampulares e as mesmas / Background: Patients with Familial Adenomatous Polyposis (FAP) have higher risk of duodenal cancer development compared with the general population. Spigelman classification has been adopted as the staging method of duodenal adenomatosis in patients with FAP. However, the relationship between the severity of duodenal polyposis and clinical variables is not well understood. Objectives: 1) To assess endoscopically, the prevalence and intensity of duodenojejunal adenomas in patients with FAP in our population. 2) To correlate clinical variables with the phenotypic severity of duodenal and ampullary adenomatosis. Methods: We prospectively studied 62 patients with FAP, attended at Intestinal polyposis Clinic of the Department of Gastroenterology, Clinics Hospital, University of São Paulo. Patients underwent duodenoscopy and were classified according to Spigelman and the presence or absence of ampullary adenomas. Patients were divided into two groups: Spigelman 0 to II and Stage III and IV. These groups were related to the clinical variables: gender, age, family history for FAP, type of colorectal surgery, and type of polyposis of the colon. Patients classified as Spigelman III and IV were submitted to balloon assisted enteroscopy for evaluation of the jejunum. Results: Forty-nine patients were staged as Spigelman 0, I or II, and 13 as stage III or IV. There was statistic significant correlation between these groups and family history (p = 0,03). Families that had several relatives included in this study showed that there was a similar Spigelman stage in different relatives of each family. Seven patients had minor ampullar adenomas. Association between ampullary adenomas and extraintestinal manifestations (p = 0.009) was statistically significant in multivariavel analysis. Balloon assisted enteroscopy was performed in 12 patients. Ten of those presented tubular adenomas with low grade dysplasia in the proximal jejunum. Conclusions: 1. The prevalence of advanced duodenal adenomatosis and ampullary adenomas is clinically significant in FAP patients of our population. 2. The prevalence of jejunal adenomas in patients with advanced duodenal adenomatosis is high, although lesions were not clinically significant. Indication for enteroscoDpy should be individualized in patients with advanced duodenal disease to evaluate jejunal disease. 3. The intensity of duodenal adenomatosis can be predicted upon the severity of duodenal polyposis of a first-degree relative. 4. The presence of extracolonic manifestations reinforces the importance for avaliation of the Vater Papilla since there was an independent association between ampullary adenomas and extracolonic manifestations

Admite-se que mais de 40% das crianças são acometidas pela desnutrição crônica em Moçambique (África Oriental). A doença pode estar relacionada, entre outros fatores, à qualidade da dieta que é oferecida à população, já que é bastante precária, pois exibe sérias deficiências de ferro, gordura e, principalmente, proteína animal em sua composição. Essa insuficiência proteica poderia acarretar em prejuízo ao desenvolvimento do organismo, pois a proteína animal é considerada uma boa fonte de aminoácidos essenciais, em decorrência de sua maior digestibilidade e absorção no intestino delgado, quando comparadas às fontes de origem vegetal. Na presente pesquisa foi reproduzida em laboratório, a dieta básica da população de Moçambique (DM), com o objetivo de avaliar seus efeitos nos componentes do plexo mioentérico e na mucosa dos segmentos do intestino delgado de ratos Wistar. Para isso, os animais foram divididos nos grupos Controle, com dieta AIN-93G com adição de 20% de caseína (NN21 e NN42); Dieta de Moçambique (DM21 e DM42) e Dieta Moçambique suplementada, acrescida de 20% de caseína (NM21 e NM42); e grupo Renutrido (RM42), composto por animais do grupo DM21 que, a partir do 22º dia, receberam a dieta NM até atingirem 42 dias de vida. Os segmentos foram coletados e submetidos às técnicas histoquímicas da NADH-diaforase e da NADPH-diaforase para evidenciação de neurônios do plexo mioentérico; histológicas (HE, Picro-sírius, Weigert) para avaliação da parede intestinal, mucosa, gânglios e seu tecido conjuntivo associado; de microscopia eletrônica de varredura (MEV) para observação da estrutura da mucosa; e de microscopia eletrônica de transmissão (MET) para a ultraestrutura dos componentes ganglionares. Estatisticamente, o peso corporal e o comprimento dos animais submetidos à dieta de Moçambique estavam abaixo dos valores encontrados para os animais controle. Na análise qualitativa, observou-se a presença de fibras elásticas, elaunínicas e oxitalânicas, assim como predominância de fibras colágenas do tipo I nos grupos NN42 e DM42, e do tipo III nos grupos NM42 e RM42 ao redor dos gânglios. A mucosa apresentou uma menor área no grupo DM21 com recuperação em DM42, com diminuição da altura das vilosidades nos dois grupos. Foram observadas alterações na organização do retículo endoplasmático rugoso e disposição dos materiais fibrilares e granulares do nucléolo dos animais DM. Sob MEV as vilosidades do grupo DM42 apresentaram superfície mais lisa, com poucas delimitações entre elas. A densidade dos neurônios reativos à NADH diminuiu de 21 para 42 dias em todos os grupos; porém, o DM21 e DM42 apresentou uma maior densidade. Os neurônios reativos à NADPH apresentaram a diminuição da densidade de 21 para 42 dias nos grupos DM e NM, quando comparados ao controle. Assim, conclui-se que a dieta vegetal de Moçambique levou à alterações na morfologia da mucosa, parede intestinal e neurônios entéricos, como uma forma de adaptação à dieta imposta / It is assumed that more than 40% of children are affected by chronic malnutrition in Mozambique (East Africa). The disease may be related, among other factors, the quality of diet that is offered to the population, since it is quite precarious, because it displays serious deficiencies of iron, fat and especially animal protein in their composition. This protein failure could result in damage to the development of the organism, as animal protein is considered a good source of essential amino acids, due to its higher digestibility and absorption in the small intestine when compared to vegetable sources. In this research has been reproduced in the laboratory, the staple diet of the population of Mozambique (DM), in order to evaluate its effects on components of the myenteric plexus and the mucosa of the small intestine segments of Wistar rats. For this, the animals were divided into control groups with AIN-93G diet with the addition of 20% casein (NN21 and NN42); Diet Mozambique (DM21 and DM42) and diet supplemented Mozambique, plus 20% casein (NM21 and NM42); and Refeeding group (RM42), consisting of the animals DM21 group, from the 22th day, given NM diet until they reached 42 days of life. The segments were collected and submitted to histochemical techniques of NADH-diaphorase and NADPH-diaphorase for disclosure of neurons of the myenteric plexus; histologic (HE, Sirius red, Weigert) for evaluation of the intestinal wall, mucosa, lymph nodes and its associated connective tissue; scanning electron microscopy (SEM) for observation of mucosal structure; and Transmission electron microscopy (TEM) ultrastructure to ganglion components. Statistically, body weight and length of the animals submitted to Mozambique diet were below the values found for control animals. Qualitative analysis showed the presence of elastic fibers, and elauninic oxytalan, and predominance of type I collagen fibers in the NN42 and DM42 groups, and type III in the NM42 and RM42 groups around the ganglia. The mucosa showed a smaller area in DM21 group recovery DM42, with a decrease in villus height in both groups. There have been changes in the organization of the rough endoplasmic reticulum and arrangement of fibrillar and granular materials nucleolus of DM animals. Under SEM the villi of the DM42 group showed smoother surface, with few boundaries between them. The density of reactive NADH decreased from 21 to 42 days in all groups; however, the DM21 and DM42 had a higher density. Reactive neurons to NADPH had decreased from 21 to 42 days density in DM and NM groups when compared to the control. Thus, it is concluded that vegetable diet Mozambique led to changes in the morphology of the mucosa, the intestinal wall and enteric neurons, as a way to adapt to the imposed diet

Les neurotoxines botuliques (BoNTs), produites par C. botulinum, sont responsables du botulisme humain et animal. Dans sa forme naturelle, le botulisme résulte le plus souvent d’une absorption des toxines botuliques à partir du tube digestif après ingestion d’aliments contaminés par la toxine et C. botulinum. L’intoxination peut être divisée en 4 grandes étapes : production de toxine par la bactérie, ingestion d’aliments contenant la toxine préformée, passage de la neurotoxine à travers la barrière intestinale et action protéolytique aux terminaisons nerveuses. La régulation de la production des toxines et le passage des neurotoxines botuliques à travers la barrière intestinale sont mal compris. BoNT s’associe à des protéines non toxiques (NAPs) pour former des complexes de différentes tailles. Les gènes codant les BoNTs et NAPs sont regroupés sur le locus botulique et leur expression est contrôlée positivement par le facteur sigma alternatif BoTR/A. La toxinogénèse chez C. botulinum est contrôlée par un réseau complexe de régulateurs incluant au moins 3 systèmes à deux composants (TCS), identifiés pas la méthode d’ARN antisens, qui régulent positivement la production de complexe botulique indépendamment de BoTR/A. D’autre part, l’entrée de BoNT/B dans la barrière intestinale a été suivie à l’aide du fragment HcB marqué en fluorescence dans une anse intestinale ligaturée de souris. Des analyses en microscopie à fluorescence, immunohistochimie et microscopie électronique ont permis de mettre en évidence que HcB transcytose à travers les entérocytes par une voie d’endocytose dépendante de la dynamine. HcB cible les terminaisons nerveuses acétylcholinergiques de la lamina propia des villosités et gagne les neurones acétylcholinergiques et sérotoninergiques de la sous-muqueuse et de la musculeuse en seulement 10 minutes. Une étude in vitro réalisée sur cellules intestinales (m-ICcl2) montre que l’entrée de HcB est dépendante de récepteurs gangliosidiques GD1b/GT1b présents à la surface des cellules mais pas de la synaptotagmine II qui est requise pour l’entrée de BoNT/B dans les cellules neuronales. / Botulinum neurotoxins (BoNTs), produced by C. botulinum, are responsible for animal and human botulism. In its natural form, botulism is mostly acquired after absorption of BoNTs in the digestive tract after ingestion of food contaminated with C. botulinum and its toxins. The intoxination can be divided in 4 major steps: toxin production, ingestion of food contaminated with BoNTs, passage of BoNTs through the intestinal barrier, and proteolytic activity on nerve endings. Regulation of toxin production and passage of BoNTs through the intestinal barrier are poorly understood. BoNT associates with non toxic protein (NAPs) to form complexes of various sizes. The BoNTs and NAPs genes are clustered in the botulinum locus and are positively regulated by an alternative sigma factor BotR/A. Toxinogenesis in C. botulinum is regulated by a complex regulatory network containing at least 3 two components systems (TCS), identified by antisens RNA strategy, which regulate the production of botulinum complex independently of BotR/A. On the other hand, BoNT/B entry was monitored with fluorescent HcB fragment in ligatureted mouse intestinal loop. Fluorescent imaging analysis, immunohistochemistry and electron microscopy, have evidence that HcB is transcytosed through enterocytes cells by an endocytosis dynamin dependant. HcB targets acetylcholinergic nerves localized in lamina propria of villi then reaches serotoninergic and acetylcholinergic nerve endings in the submucosa and musculosa within 10 minutes. In vitro experiments performed on intestinal cell line (m-ICcl2) shows that the endocytosis of HcB is dependent on the GD1b/GT1b gangliosidic receptors on the cell surface but not on the synaptotagmine II protein which is recquiered HcB entry in neuronal cells

A lesão de isquemia/reperfusão(I/R) do intestino delgado é de importância fundamental em procedimentos cirúrgicos. Alguns radicais livres de oxigênio gerados atuam durante este período. Utilizamos o ácido ascórbico para atenuar as lesões de I/R. Cinqüenta ratos foram separados e cinco grupos, cada grupo com 10 ratos. Os grupos foram sumetidos à isquemia mesentérica e isquemia/reperfusão. Os grupos experimentos receberam ácido ascórbico. Foi realizada a análise histológica morfométrica. Os grupos com ácido ascórbico mostraram uma redução significativa do infarto anti-mesentérico. (p = 0,009) na isquemia/reperfusão e redução da necrose das vilosidades na isquemia. O ácido ascórbico é eficaz na redução dos danos intestinais causados pela I/R em ratos / Intestinal injury resulting from ischemia-reperfusion (I/R) is of fundamental importance in surgical procedures. Some oxygen-derived free radicals generated during this time possibly play an important role. We used ascorbic acid to attenuate I/R injury. Fifty male rats were divided into five groups, each containing 10 rats. The groups were submitted to mesenteric ischemia and ischemia/reperfusion, experimental groups received ascorbic acid. The intestinal histological morphometric analysis was performed. The ascorbic acid groups showed a significant reduction of antimesenteric villous infarct (p=0,009) in the /R and reduction of villous necrosis ischemia groups. The ascorbic acid is effective in reducing the intestinal damage caused by I/R in the rats