198 research outputs found

    Effect of n-3 fatty acids on metabolism of apoB100-containing lipoprotein in type 2 diabetic subjects

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    The effect of long-chain n-3 PUFA on the metabolism of apoB100-containing lipoprotein in diabetic subjects is not fully understood. The objective of the present study was to determine the effect of a daily intake of 1080mg EPA and 720mg DHA for diabetic subjects on the kinetics of apoB100-containing lipoprotein in the fasting state. A kinetic study was undertaken to determine the mechanisms involved in the effects of n-3 fatty acids in terms of a decrease in triacylglycerol level in type 2 diabetic patients. We have studied the effect of fish oils on the metabolism of apoB100 endogenously labelled by [5,5,5-2H3]-leucine in type 2 diabetic patients in the fasting state. The kinetic parameters of apoB100 in VLDL, intermediate-density lipoprotein and LDL were determined by compartmental modelling in five diabetic subjects before and 8 weeks aftern-3 fatty acid treatment. Treatment did not change the plasma cholesterol level (0·801 (sd 0·120)v. 0·793 (sd 0·163) mmol/l) but lowered the plasma triacylglycerol level (1·776 (sd 0·280) v.1·356 (sd 0·595) mmol/l; p<0·05). Treated patients showed a decrease in VLDL apoB100 concentration (0·366 (sd 0·030) v.0·174 (sd 0·036) g/l; v<0·05) related to a decrease in VLDL 1 production (1·49 (sd 0·23) v.0·44 (sd 0·19) mg/kg per h; p<0·05) and an increase in the VLDL conversion rate (0·031 (sd 0·024)v.0·052 (sd 0·040) per h; p<0·05), with no change in fractional catabolic rates. Treatment led to a higher direct production of intermediate-density lipoprotein (0·02 (sd 0·01) v 0·24 (sd 0·12) mg/kg per h; p<0·05). In conclusion, the present study, conducted in the fasting state, showed that supplementation with n-3 fatty acids in type 2 diabetic patients induced beneficial changes in the metabolism of apoB100-containing lipoprotei

    Experience and Challenges from Clinical Trials with Malaria Vaccines in Africa.

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    Malaria vaccines are considered amongst the most important modalities for potential elimination of malaria disease and transmission. Research and development in this field has been an area of intense effort by many groups over the last few decades. Despite this, there is currently no licensed malaria vaccine. Researchers, clinical trialists and vaccine developers have been working on many approached to make malaria vaccine available.African research institutions have developed and demonstrated a great capacity to undertake clinical trials in accordance to the International Conference on Harmonization-Good Clinical Practice (ICH-GCP) standards in the last decade; particularly in the field of malaria vaccines and anti-malarial drugs. This capacity is a result of networking among African scientists in collaboration with other partners; this has traversed both clinical trials and malaria control programmes as part of the Global Malaria Action Plan (GMAP). GMAP outlined and support global strategies toward the elimination and eradication of malaria in many areas, translating in reduction in public health burden, especially for African children. In the sub-Saharan region the capacity to undertake more clinical trials remains small in comparison to the actual need.However, sustainability of the already developed capacity is essential and crucial for the evaluation of different interventions and diagnostic tools/strategies for other diseases like TB, HIV, neglected tropical diseases and non-communicable diseases. There is urgent need for innovative mechanisms for the sustainability and expansion of the capacity in clinical trials in sub-Saharan Africa as the catalyst for health improvement and maintained

    New Speakers and Language Revitalisation: Arpitan and Community (Re)formation

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    Today, it is uncontroversial to claim that France’s regional (minority) languages (RLs) are in decline. However, revitalisation movements have nonetheless continued to surface, and this chapter considers one by-product of such efforts: the emergence of new speakers in RL contexts. The term ‘new speaker’ refers to individuals who acquire the target language not through traditional transmission contexts (e.g. home, family), but instead as adults through language revitalisation initiatives. The chapter focuses on revitalisation efforts in the context of Francoprovençal, a severely endangered and understudied RL spoken transnationally across French, Italian and Swiss borders. A critical examination of current studies supplemented with recently collected empirical data shows new speakers to be central agents in a movement championing proto-nation-statehood across national borders, reorienting the region’s traditional sociolinguistic field

    Determinants of synaptic integration and heterogeneity in rebound firing explored with data-driven models of deep cerebellar nucleus cells

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    Significant inroads have been made to understand cerebellar cortical processing but neural coding at the output stage of the cerebellum in the deep cerebellar nuclei (DCN) remains poorly understood. The DCN are unlikely to just present a relay nucleus because Purkinje cell inhibition has to be turned into an excitatory output signal, and DCN neurons exhibit complex intrinsic properties. In particular, DCN neurons exhibit a range of rebound spiking properties following hyperpolarizing current injection, raising the question how this could contribute to signal processing in behaving animals. Computer modeling presents an ideal tool to investigate how intrinsic voltage-gated conductances in DCN neurons could generate the heterogeneous firing behavior observed, and what input conditions could result in rebound responses. To enable such an investigation we built a compartmental DCN neuron model with a full dendritic morphology and appropriate active conductances. We generated a good match of our simulations with DCN current clamp data we recorded in acute slices, including the heterogeneity in the rebound responses. We then examined how inhibitory and excitatory synaptic input interacted with these intrinsic conductances to control DCN firing. We found that the output spiking of the model reflected the ongoing balance of excitatory and inhibitory input rates and that changing the level of inhibition performed an additive operation. Rebound firing following strong Purkinje cell input bursts was also possible, but only if the chloride reversal potential was more negative than −70 mV to allow de-inactivation of rebound currents. Fast rebound bursts due to T-type calcium current and slow rebounds due to persistent sodium current could be differentially regulated by synaptic input, and the pattern of these rebounds was further influenced by HCN current. Our findings suggest that active properties of DCN neurons could play a crucial role for signal processing in the cerebellum

    Rebound Discharge in Deep Cerebellar Nuclear Neurons In Vitro

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    Neurons of the deep cerebellar nuclei (DCN) play a critical role in defining the output of cerebellum in the course of encoding Purkinje cell inhibitory inputs. The earliest work performed with in vitro preparations established that DCN cells have the capacity to translate membrane hyperpolarizations into a rebound increase in firing frequency. The primary means of distinguishing between DCN neurons has been according to cell size and transmitter phenotype, but in some cases, differences in the firing properties of DCN cells maintained in vitro have been reported. In particular, it was shown that large diameter cells in the rat DCN exhibit two phenotypes of rebound discharge in vitro that may eventually help define their functional roles in cerebellar output. A transient burst and weak burst phenotype can be distinguished based on the frequency and pattern of rebound discharge immediately following a hyperpolarizing stimulus. Work to date indicates that the difference in excitability arises from at least the degree of activation of T-type Ca2+ current during the immediate phase of rebound firing and Ca2+-dependent K+ channels that underlie afterhyperpolarizations. Both phenotypes can be detected following stimulation of Purkinje cell inhibitory inputs under conditions that preserve resting membrane potential and natural ionic gradients. In this paper, we review the evidence supporting the existence of different rebound phenotypes in DCN cells and the ion channel expression patterns that underlie their generation

    Photodegradation of polystyrene/montmorillonite clay: the effect of the type of clay and presence of salt

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    Compósitos de poliestireno/montmorilonita (PS/MMT) contendo 2,5% em peso de argila foram preparados com dois tipos de argila modificada com sais quaternários de amônio. Também foram preparadas amostras do PS + sal quaternário de amônio, utilizando-se proporção de sal semelhante à usada na modificação da argila. Todas as amostras foram expostas à radiação UV por períodos de até 12 semanas, e em seguida foram realizados testes para avaliar as modificações em massa molar, propriedades mecânicas (tração e impacto), estrutura química (FTIR) e superfície de fratura (MEV) dessas amostras. Os resultados mostraram que compostos metálicos existentes na argila catalisam o processo fotodegradativo do PS e a presença isolada do sal não altera significativamente o comportamento do PS frente à radiação UV

    Transdifferentiation of Human Circulating Monocytes Into Neuronal-Like Cells in 20 Days and Without Reprograming

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    Despite progress, our understanding of psychiatric and neurological illnesses remains poor, at least in part due to the inability to access neurons directly from patients. Currently, there are in vitro models available but significant work remains, including the search for a less invasive, inexpensive and rapid method to obtain neuronal-like cells with the capacity to deliver reproducible results. Here, we present a new protocol to transdifferentiate human circulating monocytes into neuronal-like cells in 20 days and without the need for viral insertion or reprograming. We have thoroughly characterized these monocyte-derived-neuronal-like cells (MDNCs) through various approaches including immunofluorescence (IF), flow cytometry, qRT-PCR, single cell mRNA sequencing, electrophysiology and pharmacological techniques. These MDNCs resembled human neurons early in development, expressed a variety of neuroprogenitor and neuronal genes as well as several neuroprogenitor and neuronal proteins and also presented electrical activity. In addition, when these neuronal-like cells were exposed to either dopamine or colchicine, they responded similarly to neurons by retracting their neuronal arborizations. More importantly, MDNCs exhibited reproducible differentiation rates, arborizations and expression of dopamine 1 receptors (DR1) on separate sequential samples from the same individual. Differentiation efficiency measured by cell morphology was on average 11.9 ± 1.4% (mean, SEM, n = 38,819 cells from 15 donors). To provide context and help researchers decide which in vitro model of neuronal development is best suited to address their scientific question,we compared our results with those of other in vitro models currently available and exposed advantages and disadvantages of each paradigm
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