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Ghrelin is a gut hormone that stimulates food intake. In physiological conditions, ghrelin plasma levels rise with fasting and decrease after meals. Obese individuals have low fasting ghrelin levels that rise after food restriction, which is pointed out as a reason for the difficulty in maintaining weight loss. Some bariatric surgery procedures prevent rise in ghrelin levels with weight loss and this has been hypothesised to contribute to the long-term success of the treatment. The main goal of this study was to develop a safe and effective anti-ghrelin vaccine for obesity, through the chemical conjugation of ghrelin with a virus like particle, namely NS1 protein tubules from the Bluetongue Virus (BTV) using a hetero-bifunctional cross linker. Male adult C57BL/6 mice, with a normal weight and with diet-induced obesity (DIO), were randomized into six weight matched groups (n=6/group) and each group of mice received three intra-peritoneal injections with two weeks intervals, containing either 75 µg of ghrelin-NS1 immunoconjugate, 75 µg of NS1 or PBS. Our data show that immunized animals present increasing titres of anti-ghrelin antibodies, while their cumulative food intake significantly decreased and energy expenditure was significantly enhanced, although there were no significative changes in body weight.Vaccinated DIO mice also displayed significant decrease of NPY gene expression in the basal hypothalamus reflecting a decrease in central orexigenic signals. This study suggests that this anti-ghrelin vaccine has a positive impact on energy homeostasis and may be an additional therapeutical tool to be used with diet and exercise for obesity treatment.

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Obesity has been associated with increased incidence and aggressiveness of prostate cancer. Although controversial, several studies suggest that leptin could influence tumour cell growth and proliferation. The main goal of this study was to assess cellular growth of prostate adenocarcinoma cells in obese mice with different endogenous hormonal environments in what relates to leptin circulating levels and sensitivity. Four groups of mice (n = 6/group) were used, namely obese mice with congenital non-functioning leptin receptor OBR (db/db), obese mice with congenital leptin deficiency (ob/ob), mice with diet induced obesity (DIO) and normal weight C57BL/6J mice (control). All groups of mice were injected subcutaneously with 3.0 x 10(5) RM1 cells/500 microl PBS (murine prostate carcinoma androgen insensitive cells) and tumour growth and angiogenesis were evaluated 14 days after inoculation. The tumours induced in ob/ob and DIO mice were significantly larger (P < 0.001) while those induced in db/db mice were significantly smaller (P = 0.047), when compared with controls. Morphometric analysis revealed that mitotic index and Ki-67 positive nuclear density, both cell proliferation markers, were also significantly lower in the tumours of db/db mice (P < 0.001) when compared to controls. An inverse correlation was observed between leptin plasma levels and tumour weight (r = -0.642, P < 0.001), mitotic index (r = -0.646, P < 0.01) and Ki-67 positive nuclear density (r = -0.795, P < 0.001). These results suggest that high leptin concentrations are not favourable to RM1 cell growth and proliferation. On the contrary, high plasma leptin levels were associated with less cellular proliferation and angiogenesis in vivo.

Replacing synthetic surfactants by natural alternatives when formulating nanoemulsions has gained attention as a sustainable approach. In this context, nanoemulsions based on sweet almond oil and stabilized by saponin from Quillaja bark with glycerol as cosurfactant were prepared by the high-pressure homogenization method. The effects of oil/water (O/W) ratio, total surfactant amount, and saponin/glycerol ratio on their stability were analyzed. The formation and stabilization of the oil-in-water nanoemulsions were analyzed through the evaluation of stability over time, pH, zeta potential, and particle size distribution analysis. Moreover, a design of experiments was performed to assess the most suitable composition based on particle size and stability parameters. The prepared nanoemulsions are, in general, highly stable over time, showing zeta potential values lower than −40 mV, a slight acid behavior due to the character of the components, and particle size (in volume) in the range of 1.1 to 4.3 µm. Response surface methodology revealed that formulations using an O/W ratio of 10/90 and 1.5 wt% surfactant resulted in lower particle sizes and zeta potential, presenting higher stability. The use of glycerol did not positively affect the formulations, which reinforces the suitability of preparing highly stable nanoemulsions based on natural surfactants such as saponins.

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Chronic exposure to industrial noise and its effects on biological systems. Occupational exposure to noise may result in health disorders. Our aim was to evaluate the effects of chronic exposure to high-intensity noise of textile industry cotton rooms on the adrenal morphology. The environmental noise of a cotton-mill room from a large textile factory of Northern Portugal was recorded and reproduced by an adopted electroacoustic setup in a sound-insulated animal room where the rats were housed. The sounds were reproduced at the original levels of approximately 92 dB, which was achieved by equalization and distribution of sound output in the room. Wistar rats were submitted to noise exposure, in the same time schedule as employed in textile plants. After one, three, five, and seven months, the adrenals were collected and analyzed by light microscopy. Analyzed by multivariate analysis of variance and post hoc Bonferroni correction for multiple comparisons of the means between the groups. Noise exposure induced time-dependent changes in adrenal cortex, with decrease of zona fasciculata (ZF) and increase of zona reticularis volumes, together with a significant depletion of lipid droplet density in ZF cells of exposed rats, in comparison to control rats. Chronic exposure of rats to textile industry noise triggers cytological changes in the adrenals that suggest the existence of a sustained stress response.