RESUMO No presente estudo, foram realizadas análises histológica, morfométrica e ultraestrutural para investigar as alterações da mucosa intestinal em explantes jejunais de leitões expostos a duas cepas e concentrações de Lactobacillus plantarum inativado pelo calor e seus sobrenadantes de cultura. Os explantes jejunais foram incubados durante quatro horas, em meio de cultura DMEM com: a) meio de cultura (grupo controle); b) Lactobacillus plantarum, cepa 1 - LP1 (1,1 x 108CFU/mL); c) Lactobacillus plantarum, LP2 (2,0 x 109CFU/mL); d) sobrenadante da cultura do Lactobacillus plantarum, cepa 1 (SC1); e e) sobrenadante da cultura do Lactobacillus plantarum, cepa 2 (SC2). Os explantes expostos às cepas 1 e 2 do L. plantarum inativado pelo calor mostraram atrofia difusa de vilosidades, necrose apical das vilosidades e achatamento de enterócitos. A avaliação morfológica revelou resultados semelhantes, com adesão bacteriana ao muco e às células epiteliais intestinais, e a análise morfométrica mostrou uma diminuição da altura das vilosidades em relação ao grupo controle. Alterações nos explantes tratados com o sobrenadante da cultura de ambas as cepas caracterizaram-se por atrofia leve das vilosidades e necrose apical leve dos enterócitos. A avaliação morfológica revelou vilosidades bem delineadas, e a análise morfométrica mostrou um aumento significativo na altura das vilosidades em comparação ao grupo controle. Em geral, a exposição aos sobrenadantes da cultura melhora a morfologia intestinal.

ABSTRACT In the present study, histological, morphometrical and ultrastructural analysis were performed to investigate intestinal mucosa changes in piglets jejunal explants exposed to two concentration of heat-inactivated Lactobacillus plantarum and their respective culture supernatants. Jejunal explants were incubated for 4 hours in DMEM culture medium with a) only culture medium (control group), b) heat-inactivated Lactobacillus plantarum strain1 - LP1 (1.1 x 108CFU/ml), c) heat-inactivated Lactobacillus plantarum strain2 - LP2 (2.0 x 109CFU/ml), d) heat-inactivated Lactobacillus plantarum strain1 culture supernatant (CS1), and e) heat-inactivated Lactobacillus plantarum strain2 culture supernatant (CS2). Explants exposed to heat-inactivated L. plantarum strain 1 and 2 showed multifocal to difuse villi atrophy, villi apical necrosis and enterocyte flattening. Morphological assessment revealed similar results with bacterial adhesion to mucus and intestinal epithelial cells and, morphometric analysis showed a decreased villi height compared to the control group. Alterations in explants treated with the culture supernatant of both strains include mild villi atrophy and mild enterocyte apical necrosis. Morphological assesment reveled numerous well delineated villi and, morphometric analysis showed a significant increase in villi height compared to the control group. In general, exposure to the culture supernatants improved the intestinal morphology.

Primary colorectal lymphoma is an infrequent disease of unknown origin and with a growing incidence. Differentiation be-tween primary lymphoma and secondary colorectal involvement is of great therapeutic and prognostic importance. The diagnosis must always be based on histological findings. Different forms of presentation have been described, though all are nonspecific. While full agreement on the best management approach for colorectal lymphoma is lacking, surgical resection is usually the treatment of choice. The role of chemotherapy has not been defined. This study reports on a case of primary lymphoma in the cecum, with clinical manifestations in the form of meteorism and early satiety. The diagnosis was established by colonoscopy and biopsy. The absence of lymph-node involvement, tumor size, existing cardiopulmonary risk factors, and the fact that a full resection of the malignancy proved possible, with tumor-free resection margins, led us to exclude adjuvant chemotherapy. After one year of follow-up the patient remains disease-free.

El linfoma primario colorrectal es una enfermedad muy infrecuente, de causa desconocida y con una incidencia en aumento. Diferenciar entre el linfoma primario y la afectación colorrectal secundaria en el linfoma sistémico es de elevada importancia terapéutica y pronóstica. El diagnóstico ha de ser siempre histológico. Se han descrito diferentes formas de presentación, pero todas ellas inespecíficas. No existe un total acuerdo sobre cuál es el mejor tratamiento del linfoma colorrectal. La resección quirúrgica suele ser el procedimiento de elección, sin haberse definido el papel de la quimioterapia. Presentamos un caso de linfoma primario localizado en el ciego, cuyas manifestaciones clínicas fueron meteorismo y saciedad precoz, siendo diagnosticado mediante colonoscopia y biopsia. La resección asistida por laparoscopia fue el tratamiento de elección. La no afectación ganglionar, tamaño tumoral, resección completa con márgenes libres, así como los factores de riesgo cardiopulmonares del paciente, llevaron a desestimar la quimioterapia adyuvante. Tras un año de seguimiento el paciente se encuentra libre de enfermedad.