Pancreatic Islet Cell Tumor Secreting Insulin-Like Growth Factor Type-II in a Dog

Plasma concentration and uterine and ovarian expressions of insulin-like growth factor-2 in dogs with cystic endometrial hyperplasia-pyometra

The objective of this study was to investigate the plasma concentrations of insulin-like growth factor-2 (IGF-2) as well as its expression in the uterus and ovary of healthy dogs and those with cystic endometrial hyperplasia (CEH)-pyometra complex. Group 1 (n = 10) included bitches with open cervix pyometra, while Group 2 (n = 7) consisted of clinically healthy bitches in dioestrus. The number of IGF-2 immunopositive interstitial cells was significantly higher in Group 1, whereas in Group 2 there were only two cases in which a few cells were IGF-2 immunopositive. IGF-2 immunopositivity was observed in the endometrial glandular epithelium in both groups. Additionally, interstitial fibroblasts and macrophages in the endometrium were also positive in Group 1. The concentration of plasma IGF-2 was higher in Group 1 than in Group 2 (P < 0.05). The concentration was positively correlated with IGF-2 expression in the endometrial glands (r = 0.926; P < 0.001) in Group 1. However, a negative correlation was present between plasma IGF-2 concentration and IGF-2 expression in the interstitial endocrine cells of the ovary in Group 1 (r = -0.652; P < 0.05). The results suggest that IGF-2 plays an important role during the inflammatory process occurring in bitches with CEH-pyometra complex as well as in the endometrium of healthy bitches in dioestrus.

Pathophysiology and aetiology of hypoglycaemic crises

Hypoglycaemia is a common, life-threatening complication that occurs as a component of a wide variety of disease processes. Despite its frequent occurrence, information concerning the aetiology, characteristics and outcomes of hypoglycaemic crises in veterinary medicine is limited. This review summarises the current understanding of the pathophysiology of hypoglycaemia, the body's counter-regulatory response, underlying aetiologies, diagnosis and treatment. Disease mechanisms are discussed and published evidence in veterinary literature regarding prognostic indicators, prevalence, diagnosis and treatment is examined for hypoglycaemia-related disease processes including insulinoma, glucose-lowering toxins and medications.

Canine pancreatic islet cell tumours secreting insulin-like growth factor type 2: a rare entity

Insulin-like growth factor type II (IGF-II) is the main cause of non-islet cell tumour hypoglycaemia (NICTH) and insulin is thought to be the only factor causing hypoglycaemia in insulinomas. However, two case reports of pancreatic neuroendocrine tumours (PNETs) producing IGF-II have been previously published: a human and a canine patient. In this study, we investigated clinical, histopathological, immunohistochemical and ultrastructural features, and biological behaviour of canine pancreatic IGF-II-omas, a subgroup of PNETs that has not been previously characterized. Case records of 58 dogs with confirmed PNETs and hypoglycaemia were reviewed: six patients were affected by IGF-II-omas. Surgery was performed in all cases and two dogs had metastases. Four patients remained alive and in remission at 370, 440, 560 and 890 days post-diagnosis; two died of non-tumour-related causes. IGF-II-omas can be differentiated from insulinomas through hypoinsulinaemia, IGF-II positive and insulin negative immunostaining. The prevalence of this neoplasia is low, accounting for just 6% of PNETs.

Relação da expressão de fatores de crescimento celular (IGF-1) e (SCF) com fatores prognósticos e o alvo da rapamicina em mamíferos (m-TOR) em mastocitomas cutâneos caninos

O mastocitoma cutâneo (MTC) é a neoplasia maligna mais comum na pele dos cães e seu comportamento biológico é muito variável. Dentre os fatores prognósticos estudados nos MTCs, a classificação histopatológica, o índice proliferativo e o padrão de expressão doc-KIT são os que apresentam uma associação mais relevante com o provável prognóstico deste tumor. O objetivo deste trabalho foi avaliar a expressão proteica de fator de crescimento semelhante à insulina tipo 1 (IGF-1), fator de célula tronco (SCF) e sua relação com o receptor tirosina quinase (c-KIT), alvo da rapamicina em mamíferos (m-TOR), grau histológico, índice proliferativo pelo KI-67e o número de figuras de mitose (IM) com dados clínicos de cães com MTCs . Foram utilizadas 133 amostras de MTCs, provenientes de 133 cães, dispostas em lâminas de microarranjo de tecidos (TMA). A técnica de imuno-histoquímica foi utilizada para a avaliação destas proteínas. Observou-se associação entre SCF e, a graduação histopatológica proposta em 2011, índice mitótico, proliferação celular (KI-67), escore de IGF-1, local da lesão, idade dos animais e padrão imuno-histoquímico do receptor c-KIT. A relação de dependência também foi observada entre IGF-1 e o porte dos animais, IM, m-TOR e c-KIT. A expressão de SCF teve relacção com a agressividade dos MTCs caninos, uma vez que foi mais freqüente em MTCs com c-KIT citoplasmático. A relação entre a expressão de IGF-1, SCF, c-KIT e m-TOR pode estar associada à integralização de suas vias de ação. A expressão de IGF-1 está associada à MTCs em cães de porte grande.