23 research outputs found

    Rapid establishment of teat order and allonursing in wild boar (Sus scrofa)

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    Transfer of milk is the fundamental common characteristic of mammalian reproduction, but species differ considerably with respect to nursing strategies. The consequences of teat orders and allonursing have been studied intensively in domestic pigs. However, whether similar nursing strategies also exist in wild boar, the ancestor of domestic pigs is so far not known. The occurrence of allonursing in wild boar is only described anecdotally, and the question whether a teat order is established has not yet been investigated. Studying suckling behaviour of 29 piglets from six primiparous wild boar females in a semi‐natural environment we found a surprisingly fast development of a rigid teat order among littermates, which established within 2.2 hr after birth. This suggests strong fitness benefits of this phenomenon that may ultimately explain the evolution and maintenance of this trait. We further found a strong synchrony of oestrus and delivery among the females of a group, as well as the occurrence of allonursing. By determining the amount of allonursing for the first time quantitatively, we demonstrate the importance of this trait and its presumably pivotal role for juvenile survival under truly natural conditions

    Chromium(III) biosorption onto spent grains residual from brewing industry : equilibrium, kinetics and column studies

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    The use of industrial wastes for wastewater treatment as a strategy to their re-use and valorisation may provide important advances toward sustainability. The present work gives new insights into heavy metal biosorption onto low-cost biosorbents, studying chromium(III) biosorption onto spent grains residual from a Portuguese brewing industry both in batch and expanded bed column systems. Experimental studies involved unmodified spent grains and spent grains treated with NaOH. Metal uptake followed a rapid initial step, well described by the pseudo-second-order kinetic model up to 27 h, indicating chemisorption to be the rate-limiting step. Beyond this period intraparticle diffusion assumed an important role in the uptake global kinetics. The best fit for equilibrium data was obtained using the Langmuir model, with unmodified spent grains having the higher maximum uptake capacity (q max = 16.7 mg g1). In open system studies, using expanded bed columns, the best performance was also achieved with unmodified spent grains: Breakthrough time (C/C i = 0.25) and total saturation time (C/C i = 0.99) occurred after 58 and 199 h of operation, corresponding to the accumulation of 390 mg of chromium(III), 43.3 % of the total amount entering the column. These results suggest that alkali treatment does not improve spent grains uptake performance. Changes in biomass composition determined by Fourier transform infrared spectroscopy suggested hydroxyl groups and proteins to have an important role in chromium(III) biosorption. This study points out that unmodified spent grains can be successfully used as low-cost biosorbent for trivalent chromium.The authors would like to thank the Portuguese brewing industry UNICER for all the support and FCT (Fundacao para a Ciencia e a Tecnologia) financial support through the Grant PRAXIS XXI/BD/15945/98

    Mst1/2 signalling to Yap: gatekeeper for liver size and tumour development

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    The mechanisms controlling mammalian organ size have long been a source of fascination for biologists. These controls are needed to both ensure the integrity of the body plan and to restrict inappropriate proliferation that could lead to cancer. Regulation of liver size is of particular interest inasmuch as this organ maintains the capacity for regeneration throughout life, and is able to regain precisely its original mass after partial surgical resection. Recent studies using genetically engineered mouse strains have shed new light on this problem; the Hippo signalling pathway, first elucidated as a regulator of organ size in Drosophila, has been identified as dominant determinant of liver growth. Defects in this pathway in mouse liver lead to sustained liver overgrowth and the eventual development of both major types of liver cancer, hepatocellular carcinoma and cholangiocarcinoma. In this review, we discuss the role of Hippo signalling in liver biology and the contribution of this pathway to liver cancer in humans

    New cellular tools reveal complex epithelial–mesenchymal interactions in hepatocarcinogenesis

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    To enable detailed analyses of cell interactions in tumour development, new epithelial and mesenchymal cell lines were established from human hepatocellular carcinoma by spontaneous outgrowth in culture. We obtained several hepatocarcinoma (HCC)-, B-lymphoblastoid (BLC)-, and myofibroblastoid (MF)-lines from seven cases. In-depth characterisation included cell kinetics, genotype, tumourigenicity, expression of cell-type specific markers, and proteome patterns. Many functions of the cells of origin were found to be preserved. We studied the impact of the mesenchymal lines on hepatocarcinogenesis by in vitro assays. BLC- and MF-supernatants strongly increased the DNA replication of premalignant hepatocytes. The stimulation by MF-lines was mainly attributed to HGF secretion. In HCC-cells, MF-supernatant had only minor effects on cell growth but enhanced migration. MF-lines also stimulated neoangiogenesis through vEGF release. BLC-supernatant dramatically induced death of HCC-cells, which could be largely abrogated by preincubating the supernatant with TNFÎČ-antiserum. Thus, the new cell lines reveal stage-specific stimulatory and inhibitory interactions between mesenchymal and epithelial tumour cells. In conclusion, the new cell lines provide unique tools to analyse essential components of the complex interplay between the microenvironment and the developing liver cancer, and to identify factors affecting proliferation, migration and death of tumour cells, neoangiogenesis, and outgrowth of additional malignancy

    Pre-treatment and extraction techniques for recovery of added value compounds from wastes throughout the agri-food chain

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    Pre-treatment and extraction techniques for recovery of added value compounds from wastes throughout the agri-food chain

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    The enormous quantity of food wastes discarded annually force to look for alternatives for this interesting feedstock. Thus, food bio-waste valorisation is one of the imperatives of the nowadays society. This review is the most comprehensive overview of currently existing technologies and processes in this field. It tackles classical and innovative physical, physico-chemical and chemical methods of food waste pre-treatment and extraction for recovery of added value compounds and detection by modern technologies and are an outcome of the COST Action EUBIS, TD1203 Food Waste Valorisation for Sustainable Chemicals, Materials and Fuels

    The haemochromatosis gene Hfe and Kupffer cells control LDL cholesterol homeostasis and impact on atherosclerosis development.

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    Imbalances of iron metabolism have been linked to the development of atherosclerosis. However, subjects with hereditary haemochromatosis have a lower prevalence of cardiovascular disease. The aim of our study was to understand the underlying mechanisms by combining data from genome-wide association study analyses in humans, CRISPR/Cas9 genome editing, and loss-of-function studies in mice. Our analysis of the Global Lipids Genetics Consortium (GLGC) dataset revealed that single nucleotide polymorphisms (SNPs) in the haemochromatosis gene HFE associate with reduced low-density lipoprotein cholesterol (LDL-C) in human plasma. The LDL-C lowering effect could be phenocopied in dyslipidaemic ApoE-/- mice lacking Hfe, which translated into reduced atherosclerosis burden. Mechanistically, we identified HFE as a negative regulator of LDL receptor expression in hepatocytes. Moreover, we uncovered liver-resident Kupffer cells (KCs) as central players in cholesterol homeostasis as they were found to acquire and transfer LDL-derived cholesterol to hepatocytes in an Abca1-dependent fashion, which is controlled by iron availability. Our results disentangle novel regulatory interactions between iron metabolism, KC biology and cholesterol homeostasis which are promising targets for treating dyslipidaemia but also provide a mechanistic explanation for reduced cardiovascular morbidity in subjects with haemochromatosis
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