Leptin is a protein hormone synthesised and secreted by white adipocytes. This hormone is involved in various metabolic processes, energy balance, fertility, inflammation and angiogenesis. In order to have a system for determining the concentration of leptin in goats, in this work we developed and validated an immunodiagnostic system (ELISA) using goat leptin obtained in recombinant form in Escherichia coli. Polyclonal antibodies were prepared in rabbits and a specific ELISA system was developed, then the binding capacity of the recombinant leptin specific to the receptor in the central nervous system was demonstrated by immunohistochemistry. Prior to the development of immunometric system, reagents were evaluated in a commercial RIA standardised system, and results indicated support for the evaluation system. The displacement curve of recombinant leptin showed no difference in the slope or the correlation coefficient with reference leptin, although the IC50 dose was lower. Binding capacity of the recombinant protein to specific receptors in the hypothalamus was identified. No significant differences in plasma concentrations of leptin obtained by ELISA and those obtained in the study using the RIA formulated for ruminants were obtained. These observations suggest that the developed ELISA could be an effective method for determining the concentration of goat serum leptin.

La leptina es una hormona proteica sintetizada y secretada por los adipocitos blancos, que controla varios procesos metabólicos, balance energético, fertilidad, inflamación y angiogénesis. Este estudio muestra el desarrollo y validación de un sistema de inmunodiagnóstico (ELISA) usando la leptina de cabra recombinante generada en Escherichia coli, a partir de esta se generó su correspondiente anticuerpo policlonal en conejos. Previo al desarrollo del sistema se demostró por inmunohistoquímica la capacidad de unión de la leptina recombinante específica a su receptor en el sistema nervioso central. Adicionalmente, el antígeno y el anticuerpo generados se evaluaron en un sistema normalizado de RIA comercial. Para validar el ELISA se comparó las concentraciones plasmáticas de leptina obtenidas con el ELISA en estudio y con un RIA para rumiantes. La curva de desplazamiento de la leptina recombinante no mostró diferencia en su pendiente ni en el coeficiente de correlación con la leptina de referencia, aunque la dosis IC50 fue menor. Se demostró la capacidad de unión de la proteína recombinante a receptores específicos del hipotálamo caprino. No hubo diferencias significativas en las concentraciones plasmáticas de leptina obtenidas por el ELISA en estudio y aquellas obtenidas utilizando el RIA formulado para rumiantes. Los resultados sugieren que el ELISA desarrollado podría ser un método eficaz para determinar la concentración de leptina en suero de cabra.

Calciphylaxis is a rare but important cause of severe morbidity, which predominantly affects patients with advanced chronic kidney disease. It is associated with mortality in excess of 50% at one year, and this has changed little over the last 20 years despite advances in our understanding of its underlying pathophysiology, and evolving treatment strategies. Sodium thiosulphate has played a prominent role in the treatment of calciphylaxis since its first use in 2004, with reports of success both in improving the severe pain associated with the condition and in the healing of calciphylaxis lesions. The literature documenting the use of sodium thiosulphate in the treatment of calciphylaxis is reviewed here, along with a detailed summary of case reports and case series. While there is reason to be optimistic with regard to the efficacy of sodium thiosulphate within a multifaceted and multidisciplinary approach to treatment, there is clearly much yet to be learned

Modelos experimentais de tumores cerebrais malignos geralmente utilizam células imunologicamente compatíveis com o animal receptor. Neste estudo apresentamos um modelo experimental baseado na inoculação de células C6 em ratos atímicos Rowett, visando obter um tumor que se assemelhe mais àqueles observados nos seres humanos. Neste modelo observamos microinfiltração de ilhotas de células na periferia da massa tumoral principal e nas áreas mais distantes, células tumorais isoladas no tecido cerebral normal. Este grau de infiltração é superior àquele observado em outros modelos utilizando as células C6.

Malignant brain tumor experimental models tend to employ cells that are immunologically compatible with the receptor animal. In this study, we have proposed an experimental model of encephalic tumor development by injecting C6 cells into athymic Rowett rats, aiming at reaching a model which more closely resembles to the human glioma tumor. In our model, we observed micro-infiltration of tumor cell clusters in the vicinity of the main tumor mass, and of more distal isolated tumor cells immersed in normal encephalic parenchyma. This degree of infiltration is superior to that usually observed in other C6 models.