Ectopic ACTH syndrome in a dog with a mesenteric neuroendocrine tumour: a case report

Ectopic ACTH secretion is provoked by extra-pituitary tumours that secrete ACTH, constituting an infrequent type of Cushing Syndrome in the dog. Neuroendocrine tumours (NET) are characterised by the synthesis of peptides with hormone activity. A dog with clinical diagnosis of Cushing?s syndrome and presenting an abdominal tumour located in the area of the left adrenal gland was sent to the hospital. Cortisol was not inhibited at four and eight hours after the application of low-dose dexamethasone and the cortisol/creatinine ratio was elevated (93 × 10-6, reference values < 10 × 10?6). Plasma ACTH measurements were high (28.6 pmol/l, reference values 5.5?14.3 pmol/l). On computed tomography, the tumour was found in the meso-epigastrium, with both adrenal glands hyperplasic and no alteration of the pituitary image. The tumour was located between the two layers of the meso-colon and was removed using laparoscopy. After surgery, ACTH concentrations became normal and clinical signs remitted. The histopathological diagnosis was NET, with positive ACTH immunostaining.Fil: Castillo, V. A.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Pessina, P. P.. Universidad de la Republica; UruguayFil: García, J. D.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Hall, P.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Galleli, M. F.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Miceli, Diego Daniel. Universidad de Buenos Aires. Facultad de Cs.veterinarias. Departamento de Medicina. Clinica Medica de Animales Peque?os; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Cabrera Blatter, M. F.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; Argentin

Increased resistance and depressed delayed-type hypersensitivity to Listeria monocytogenes induced by pretreatment with lipopolysaccharide.

Intravenous injection of a small dose of lipopolysaccharide 24 h before infection with Listeria monocytogenes enhanced the resistance of mice to this organism. This protective effect of lipopolysaccharide related to the ability of nonimmune macrophages to inhibit bacterial proliferation in livers and spleens. Surprisingly, lipopolysaccharide-treated mice exhibited inferior acquired immunity, as measured by adoptive transfer of immunity to normal mice, delayed-type hypersensitivity to Listeria antigens, and uptake of tritiated thymidine by lymphocytes in the spleen. These results support the view that lipopolysaccharide stimulates a highly effective anti-Listeria immunity via the macrophage component, despite interference with the lymphocyte component