A Reappraisal of the Mechanism by Which Plant Sterols Promote Neutral Sterol Loss in Mice

Dietary plant sterols (PS) reduce serum total and LDL-cholesterol in hyperlipidemic animal models and in humans. This hypocholesterolemic effect is generally ascribed to inhibition of cholesterol absorption. However, whether this effect fully explains the reported strong induction of neutral sterol excretion upon plant sterol feeding is not known. Recent data demonstrate that the intestine directly mediates plasma cholesterol excretion into feces, i.e., without involvement of the hepato-biliary route

HISTOFLASH: una eina per al reconeixement de teixits que millora l'aprenentatge

Podeu consultar la Vuitena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/66524Els estudiants de Fisiologia i Fisiopatologia III del Grau de Farmàcia realitzen pràctiques de laboratori entre d’altres activitats complementàries. El curs 2011-12, l’Equip Docent de l’assignatura va posar a punt una pràctica d'histologia que té com a objectiu que els estudiants, per mitjà de l'observació al microscopi òptic, identifiquin estructures en diferents sistemes orgànics. El temps dedicat a aquesta pràctica depenia, en gran mesura, de les habilitats de l’estudiant i de la presència del professor, que havia de confirmar o corregir la identificació que feia l'alumne i donar les pautes per a una correcte interpretació de les preparacions. En una enquesta realitzada durant el curs 2012-2013, un 84% dels estudiants van opinar que seria útil disposar de les imatges de les preparacions, tant per preparar la pràctica com per repassar els continguts posteriorment. En aquest context, l’Equip Docent de l’assignatura ha creat un programa interactiu, l’Histoflash, que permet a l’alumne estudiar els teixits a l’ordinador a través de la simulació de l’observació al microscopi. El desenvolupament i l’aplicació del programa pretén facilitar l’aprenentatge autònom dels estudiants per a millorar de forma no presencial les habilitats d’observació al microscopi, prèviament i posteriorment a les que adquireixen al laboratori de pràctiques. Durant el curs 2013-2014, per mitjà d’una enquesta, es va observar que els estudiants valoren molt positivament aquesta eina ja que poden dedicar a cada preparació el temps necessari segons les seves necessitats. A més a més, en les activitats d’avaluació del curs 2013-14, el nombre d’estudiants que supera aquesta pràctica ha augmentat significativament després de la implementació d’aquesta eina. Es pot concloure que l’Histoflash és un bon complement a l’activitat presencial i facilita el procés de ensenyament-aprenentatge

Plasma bile acids are not associated with energy metabolism in humans

Bile acids (BA) have recently been shown to increase energy expenditure in mice, but this concept has not been tested in humans. Therefore, we investigated the relationship between plasma BA levels and energy expenditure in humans. Type 2 diabetic (T2DM) patients (n = 12) and gender, age and BMI-matched healthy controls (n = 12) were studied before and after 8 weeks of treatment with a BA sequestrant. In addition, patients with liver cirrhosis (n = 46) were investigated, since these display elevated plasma BA together with increased energy expenditure. This group was compared to gender-, age- and BMI-matched healthy controls (n = 20). Fasting plasma levels of total BA and individual BA species as well as resting energy expenditure were determined. In response to treatment with the BA sequestrant, plasma deoxycholic acid (DCA) levels decreased in controls (-60%, p &lt;0.05) and T2DM (-32%, p &lt;0.05), while chenodeoxycholic acid (CDCA) decreased in controls only (-33%, p &lt;0.05). Energy expenditure did not differ between T2DM and controls at baseline and, in contrast to plasma BA levels, was unaffected by treatment with the BA sequestrant. Total BA as well as individual BA species did not correlate with energy expenditure at any time throughout the study. Patients with cirrhosis displayed on average an increase in energy expenditure of 18% compared to values predicted by the Harris-Benedict equation, and plasma levels of total BA (up to 12-fold) and individual BA (up to 20-fold) were increased over a wide range. However, neither total nor individual plasma BA levels correlated with energy expenditure. In addition, energy expenditure was identical in patients with a cholestatic versus a non-cholestatic origin of liver disease while plasma total BA levels differed four-fold between the groups. In conclusion, in the various (patho) physiological conditions studied, plasma BA levels were not associated with changes in energy expenditure. Therefore, our data do not support an important role of circulating BA in the control of human energy metabolism.</p

Creació i aplicació del programa HISTOFLASH a les classes pràctiques d'histologia de l'assignatura Fisiologia i Fisiopatologia III del Grau de Farmàcia de la Universitat de Barcelona. Programa interactiu com a eina d'aprenentatge

Els estudiants de Fisiologia i Fisiopatologia III del Grau de Farmàcia realitzen pràctiques de laboratori entre d'altres activitats complementàries. Una de les pràctiques es basa en l'observació i identificació de teixits humans sans i patològics de diferents sistemes orgànics. L'equip docent de l'assignatura ha creat un programa interactiu, l'Histoflash, que permet a l'alumne estudiar els teixits a l'ordinador a través de la simulació de l'observació al microscopi

Efecte de la ingesta de fitosterols i pectines sobre el perfil lipídic en conills d'índies

[cat] Actualment, les malalties cardiovasculars són la primera causa de mortalitat als països desenvolupats, on el consum de greix, ric en àcids grassos saturats, i el de colesterol és elevat. En aquests països, es troben comercialitzats un gran nombre de productes als que se'ls han afegit fitosterols i/o pectines. Nombrosos estudis clínics atribueixen, tant als fitosterols com a les pectines, propietats hipocolesterolemiants. No obstant, cap d'aquests estudis ha avaluat els efectes d'aquests compostos quan, al mateix temps, l'alimentació és rica en àcids grassos saturats i colesterol. Por aquesta raó, es va plantejar l'estudi dels efectes de la addició de fitosterols i pectines sobre el perfil lipídic en conills d'índies, quan aquests ingredients funcionals es subministren conjuntament amb greixos amb alt contingut en àcids grassos saturats i colesterol. Con aquests plantejament previ, l¡addició de fitosterols no va modificar els valors de colesterol en sang mentre que, al seu torn es va incrementar l'absorció d'àcids grassos saturats de cadena mitja (làurico i mirístic) i es va disminuir el colesterol "output". Per altra banda, l'addició de pectina tampoc va disminuir les concentracions de colesterol plasmàtiques, possiblement degut a una hidròlisis prematura d'aquesta fibra. En resum, en el nostre estudi l'addició de pectina i fitosterols subministrats conjuntament amb una alimentació rica en greixos amb alt contingut en àcid grassos saturats i colesterol no va tenir cap efecte beneficiós sobre el perfil lipídic del model animal utilitzat en aquest assaig.[eng] Nowadays, cardiovascular diseases are the leading cause of death and illness in developed countries, where the consumption of saturated fat and cholesterol is high. In these countries, many functional foods enriched with phytosterols and pectin (described as cholesterol-lowering agents) are on the food market. However, they should never be used to counterbalance the effects of an unhealthy diet. Thus, the aim of this thesis was to study the effects of a high-saturated diet enriched with phytosterols and pectin on the lipid profile in an animal model. Phytosterol addition to high-saturated diet did not lower cholesterolemia, did enhance absorption of medium-chain saturated fatty acids (lauric and myristic) and did reduce in cholesterol output. Moreover, pectin addition did not reduce plasma cholesterol concentrations, maybe because of an early breakdown of this soluble fiber. Thus, in our study, the addition of phytosterols and pectin to a high-saturated diet did not show any beneficial effect on the lipid profile

Metabolic Effects of Bile Acids in the Gut in Health and Disease

In the last decade, it became clear that bile acids, in addition to their role in intestinal absorption of lipids and fat-soluble vitamins, are major regulators of metabolism. They activate signal transduction pathways through binding to the specific bile acid receptors TGR5 and FXR. Indirectly, bile acids influence metabolism via modification of the gut microbiota ecosystem. The relation between bile acid metabolism and gut microbiota composition is very complex whereas gut microbiota modulates bile acid structure, creating a complex bile acid pool consisting of a mixture of differentially structured species, bile acids alter gut microbiota by disturbing bacterial membrane integrity. In addition, to the effects on glucose and energy homeostasis, recent literature ascribed a role for bile acid signaling in control of inflammation and regulation of the nervous system. In this review, we discuss a selection of recent published studies describing the effects of intestinal bile acid signaling on health and disease

Metabolic Effects of Bile Acids in the Gut in Health and Disease

In the last decade, it became clear that bile acids, in addition to their role in intestinal absorption of lipids and fat-soluble vitamins, are major regulators of metabolism. They activate signal transduction pathways through binding to the specific bile acid receptors TGR5 and FXR. Indirectly, bile acids influence metabolism via modification of the gut microbiota ecosystem. The relation between bile acid metabolism and gut microbiota composition is very complex whereas gut microbiota modulates bile acid structure, creating a complex bile acid pool consisting of a mixture of differentially structured species, bile acids alter gut microbiota by disturbing bacterial membrane integrity. In addition, to the effects on glucose and energy homeostasis, recent literature ascribed a role for bile acid signaling in control of inflammation and regulation of the nervous system. In this review, we discuss a selection of recent published studies describing the effects of intestinal bile acid signaling on health and disease

Metabolic Effects of Bile Acids in the Gut in Health and Disease

In the last decade, it became clear that bile acids, in addition to their role in intestinal absorption of lipids and fat-soluble vitamins, are major regulators of metabolism. They activate signal transduction pathways through binding to the specific bile acid receptors TGR5 and FXR. Indirectly, bile acids influence metabolism via modification of the gut microbiota ecosystem. The relation between bile acid metabolism and gut microbiota composition is very complex whereas gut microbiota modulates bile acid structure, creating a complex bile acid pool consisting of a mixture of differentially structured species, bile acids alter gut microbiota by disturbing bacterial membrane integrity. In addition, to the effects on glucose and energy homeostasis, recent literature ascribed a role for bile acid signaling in control of inflammation and regulation of the nervous system. In this review, we discuss a selection of recent published studies describing the effects of intestinal bile acid signaling on health and disease

Bile acid sequestrants: more than simple resins

Purpose of review Bile acid sequestrants (BAS) have been used for more than 50 years in the treatment of hypercholesterolemia. The last decade, bile acids are emerging as integrated regulators of metabolism via induction of various signal transduction pathways. Consequently, BAS treatment may exert unexpected side-effects. We discuss a selection of recently published studies that evaluated BAS in several metabolic diseases. Recent findings Recently, an increasing body of evidence has shown that BAS in addition to ameliorating hypercholesterolemia are also effective in improving glycemic control in patients with type 2 diabetes, although the mechanism is not completely understood. Furthermore, some reports suggested using these compounds to modulate energy expenditure. Many of these effects have been related to the local effects of BAS in the intestine by directly binding bile acids in the intestine or indirectly by interfering with signaling processes. Summary A substantial effort is being made by researchers to fully define the mechanism by which BAS improve glycemic control in type 2 diabetic patients. A new challenge will be to confirm in clinical trials the recent discoveries coming from animal experiments suggesting a role for bile acids in energy metabolism

Reverse Cholesterol Transport Revisited Contribution of Biliary Versus Intestinal Cholesterol Excretion

Reverse cholesterol transport (RCT) is usually defined as high-density lipoprotein-mediated transport of excess cholesterol from peripheral tissues, including cholesterol-laden macrophages in vessel walls, to the liver. From the liver, cholesterol can then be removed from the body via secretion into the bile for eventual disposal via the feces. According to this paradigm, high plasma high-density lipoprotein levels accelerate RCT and hence are atheroprotective. New insights in individual steps of the RCT pathway, in part derived from innovative mouse models, indicate that the classical concept of RCT may require modification. (Arterioscler Thromb Vasc Biol. 2011;31:1726-1733.