Browsing by Author "Oliveira, J."
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- Biochemical and histological effects of sitagliptin on Zucker Diabetic Fatty rat pancreasPublication . Mega, C.; Vala, Helena; Teixeira de Lemos, E.; Fernandes, R.; Oliveira, J.; Ferreira, L.; Teixeira, F.; Reis, F.Background: Inhibition of dipeptidyl peptidase-4 (DPP-4) activity by sitagliptin has been shown to improve glycemic control in patients with type 2 diabetes Mellitus (T2DM) by prolonging the actions of incretin hormones, but the really impact of low-dose sitagliptin treatment on pancreas lesions is almost unknown. This study aimed to evaluate the effects of sitagliptin on biochemical and histological (pancreas) parameters of Zucker Diabetic Fatty (ZDF, fa/fa) rats, an animal model of T2DM. Methods: Diabetic (fa/fa) ZDF male rats were treated with vehicle or sitagliptin (10 mg/kg BW/day) during 6 weeks (n=8 each). The following parameters were assessed: serum glycaemia, HbA1c, insulin and lipid profile; serum and pancreas oxidative stress (MDA) and endocrine and exocrine pancreas histology, estimating and rating inflammatory infiltrate, fibrosis, vacuolization and congestion in a semiquantitative score ranging from 0 (minimal) to 3 (severe and extensive damage). Results: Sitagliptin in diabetic ZDF rats promoted beneficial effects on dysglycaemia, dyslipidaemia, inflammatory profile and pancreatic oxidative stress. Endocrine and exocrine pancreas presented a reduction/amelioration of fibrosis severity, inflammatory infiltrate, intra-islet vacuolation, and congestion vs the vehicle-treated diabetic rats. Conclusions: The favourable biochemical profile promoted by sitagliptin in the diabetic rats, together with a protection against endocrine and exocrine pancreas lesions, might represent a further advantage of low doses of sitagliptin in the management of T2DM.
- Cuidados de enfermagem em timpanismoPublication . Oliveira, J.; Oliveira, J.; Rego, A.; Valente, A.; Nascimento, R.; Vala, Helena; Mesquita, J.; Nóbrega, C.O timpanismo ruminal designa-se pela acumulação excessiva de gases e por vezes fluidos no retículo-rúmen, incapazes de serem eliminados pelo organismo, o que resulta no aumento anormal do abdómen (Radostits et al, 2007). Afecta ruminantes e é uma situação que pode desenvolver-se rapidamente e pôr em risco a vida do animal (Streeter, 2009). Este estudo sintetiza a etiologia, o diagnóstico, o tratamento e aconselhamento que é aplicável a esta patologia, procurando evidenciar o papel do enfermeiro veterinário em cada um dos parâmetros apresentados.
- Diabetic nephropathy amelioration by a low-dose sitagliptin in an animal model of type 2 diabetes (Zucker Diabetic Fatty rat)Publication . Mega, C.; Teixeira de Lemos, E.; Vala, Helena; Fernandes, R.; Oliveira, J.; Mascarenhas-Melo, F.; Teixeira, F.; Reis, F.This study was performed to assess the effect of chronic low-dose sitagliptin, a dipeptidyl peptidase 4 inhibitor, on metabolic profile and on renal lesions aggravation in a rat model of type-2 diabetic nephropathy, the Zucker Diabetic Fatty (ZDF) rat. Diabetic and obese ZDF (fa/fa) rats and their controls ZDF (+/+) were treated for 6 weeks with vehicle (control) or sitagliptin (10 mg/kg/bw). Blood/serum glucose, HbA1c, insulin, Total-c, TGs, urea and creatinine were assessed, as well as kidney glomerular and tubulointerstitial lesions (interstitial fibrosis/tubular atrophy), using a semi-quantitative rating from 0 (absent/normal) to 3 (severe and extensive damage). Vascular lesions were scored from 0-2. Sitagliptin in the diabetic rats promoted an amelioration of glycemia, HbA1c, Total-c and TGs, accompanied by a partial prevention of insulinopenia. Furthermore, together with urea increment prevention, renal lesions were ameliorated in the diabetic rats, including glomerular, tubulointerstitial and vascular lesions, accompanied by reduced lipid peroxidation. In conclusion, chronic low-dose sitagliptin treatment was able to ameliorate diabetic nephropathy, which might represent a key step forward in the management of T2DM and this serious complication.
- Nursing care in gastric dilatation in dogsPublication . Valente, A.; Rego, A.; Nascimento, R.; Oliveira, J.; Vala, Helena; Mesquita, Jr.; Nóbrega, C.Gastric Dilatation is a potentially fatal gastrointestinal pathology caused by aerophagy. It is mainly caused by rapid consumption of food, excitation or exercising near the time of feeding, which promotes the entrance of air into the stomach (Robbins et al, 2011). With this work we aim to emphasize the care given by veterinary nurses in this pathology.
- Pancreatic lesions and metabolic aggravation are prevented by low doses of sitagliptin in a rat model of type 2 diabetesPublication . Mega, C.; Vala, Helena; Oliveira, J.; Fernandes, R.; Mascarenhas-Melo, F.; Parada, B.; Pinto, R.; Teixeira, F.; Teixeira de Lemos, E.; Reis, F.Introduction: The management of type 2 diabetes is designed to reduce disease-related complications and improve long-term outcomes. Inhibition of dipeptidyl peptidase-4 (DPP-4) activity by sitagliptin has been shown to improve glycaemic control in patients with type 2 diabetes Mellitus (T2DM) by prolonging the actions of incretin hormones, but the real impact of low-dose sitagliptin treatment on cardiometabolic risk factors and pancreatic lesions is almost unknown. This study aimed to evaluate the effects of low doses of sitagliptin on cardiovascular risk factors and histological pancreas parameters in Zucker Diabetic Fatty rats (ZDF (fa/fa)) an animal model of T2DM. Materials and Methods: Twenty weeks old diabetic obese (fa/fa) ZDF male rats were treated with vehicle or sitagliptin (10 mg/kg BW/day) during 6 weeks (n=8 each). The following parameters were assessed: glycaemia, HbA1c, insulin, lipidic profile; blood pressure. Specimens for pancreatic histopathology were stained with haematoxylin-eosin and periodic-acid-Shiff, examined by light microscopy. Endocrine and exocrine pancreas was evaluated semiquantitatively concerning inflammatory infiltrate, fibrosis, vacuolization and congestion, and scored from 0 (absent) to 3 (severe and extensive damage). Results: Sitagliptin in diabetic obese ZDF rats promoted a positive effect on dysglycaemia, dyslipidaemia and prevented the increase of blood pressure. Endocrine and exocrine pancreas presented a reduction/amelioration of fibrosis severity, inflammatory infiltrate, intra-islet vacuolation, and congestion vs the vehicle-treated diabetic rats. Conclusion: Simultaneous improvement of a sustainable glycaemic profile and of pancreatic histopathological lesions supports the favorable cardiovascular risk profile and may prove beneficial in decreasing long-term complications of T2DM.
- Pancreatic protection afforded by sitagliptin in a rat model of type 2 diabetes: putative mechanismsPublication . Mega, C.; Vala, Helena; Oliveira, J.; Teixeira, F.; Fernandes, R.; Teixeira de Lemos, E.; Reis, F.
- Progression of renal disease in the Zucker Diabetic Fatty rat, an experimental model of Type2 DiabetesPublication . Mega, C.; Vala, Helena; Oliveira, J.; Fernandes, R.; Mascarenhas-Melo, F.; Parada, B.; Pinto, R.; Teixeira, F.; Reis, F.; Teixeira de Lemos, E.
- Pulmonary and subcutaneos emphysemaPublication . Rego, A.; Nascimento, R.; Valente, A.; Mesquita, J.; Nobrega, C.; Oliveira, J.; Vala, HelenaEmphysema is an accumulation of air quite frequent in dogs, being the Pekingese the most susceptible breed. Given the lack of collateral ventilation, horses, cattle, sheep and pigs are also susceptible to this condition (Porter et al., 2011). The main objective of this work is to highlight the care that should be given by veterinary nurses to emphysematous patients.
- Rabbit haemorrhagic disease (RHD) – a new variant?Publication . Vala, Helena; Coelho, C.; Nóbrega, C.; Mesquita, JR.; Oliveira, J.Background: Rabbit haemorrhagic disease (RHD) is an acute fatal disease of domestic and wild European rabbits caused by a RNA virus (genus Lagovirus, family Caliciviridae). Prior to 1984, healthy rabbits in European regions had RHDV-specific antibodies and their infection with benign rabbit caliciviruses conferred them a low degree of cross-protective immunity against RHD, determining less severe clinical courses. Vaccination allowed to control the disease in the rabbit industry, but RHD still threatens non-vaccinated wild populations. A new variant of this disease is being described since 2010 in Iberian Peninsula. It affects mainly young rabbits that exhibit haemorrhages in heart, trachea, thymus, lungs, liver, kidneys and gut, as well as DIC, jaundice, splenomegaly and catarrhal enteritis. Objectives: To describe a case of high mortality rate on a rabbitry, mostly in young rabbits, with typical lesions of RHD. Methods: Samples from domestic vaccinated and non vaccinated rabbits which died suddenly were taken and fixed in 10% neutral-buffered formalin for 48 hours and embedded in paraffin. 3µm sections were stained for routine histopathological diagnosis (H&E) and examined by light microscopy. Results: Main macroscopic lesions observed: opisthotonos, oedema and pulmonary congestion, severe jaundice, splenomegaly, gastric punctiform ulcers, bilateral renal congestion and thymic petechiae, Conclusions: Macroscopic lesions in infected young’s, consistent with RHD infection usually observed only in adult rabbits, and the presence of lesions mostly associated to the new variant of RHD (DIC, jaundice, splenomegaly, catarrhal enteritis), led us to consider the presence of the new variant of RHD in Portugal, although further studies are needed.
- Renal structure modification in an animal model of type 2 diabetes with aging: focus on hydronephrosisPublication . Mega, C.; Vala, Helena; Oliveira, J.; Fernandes, R.; Mascarenhas-Melo, F.; Parada, B.; Pinto, R.; Teixeira, F.; Teixeira de Lemos, E.; Reis, F.Background and aims: The Zucker Diabetic Fatty (ZDF-fa/fa) rat is one of the most used models for the study of type 2 diabetes (T2DM). Characterization of renal morphology in this model may provide useful insights into the mechanism of diabetic nephropathy progression. The purpose of the present study was to determine renal morphology, identify and characterize renal dysfunction complications such as hydronephrosis, in Zucker Diabetic fatty (ZDF) rat through T2DM evolution. Material and Methods: Male diabetic obese ZDF (fa/fa) rats were sacrificed at 8, 20 and 26 weeks of age and compared with their lean counterparts ZDF (+/+) with de same age. Biochemistry in serum for metabolic assessment was also performed. Kidney slices stained with hematoxylin-eosin and periodic acid-Schiff were evaluated. A semiquantitative rating was assigned for hydronephrosis and scored from 0 (normal) to 3 (severe), based on conformational aspects of the papilla and calyx and cortex compression. Results: A striking progression in the severity of hydronephrosis was observed. All end-disease state rats, 26 weeks of age, showed hydronephrosis, which was more severe in the diabetic rats (scoring: 2, 3) when compared to lean controls (scoring 1). No significant cortical atrophy was found. These abnormalities accompanied aggravation in diabetic desmetabolism. Conclusions: The present study indicates that ZDF rats present nephropathy with hydronephrosis. Lesions are age-related and aggravated by diabetic desmetabolism but don’t hinder morphological evaluation. Therefore the ZDF rat might represent a useful model for the preclinical study of therapeutic interventions in diabetic nephropathy.