Gas Chromatography Combustion Isotope Ratio Mass Spectrometry to Detect Differences in Four Compartments of Simmental Cows Fed on C3 and C4 Diets.

Fatty acids (FAs) metabolism in animals represents an important field of study since they influence the quality and the properties of the meat. The aim of this study is to assess the possibility to discriminate the diets of cows in different animal compartments and to study the fate of dietary FAs in the bovine organism, using carbon isotopic ratios. Five FAs, both essential (linoleic and linolenic) and non-essential (palmitic, stearic, and oleic) in four compartments (feed, rumen, liver, meat) of animals fed two different diets (based on either C3 or C4 plants) were considered. For all compartments, the carbon isotopic ratio (δ13C) of all FAs (with few exceptions) resulted significantly lower in cows fed on C3 than C4 plants, figuring as a powerful tool to discriminate between different diets. Moreover, chemical reactions taking place in each animal compartment result in fraction processes affecting the δ13C values. The δ13CFAs tendentially increase from feed to meat in group C3. On the other hand, the δ13CFAs generally increase from rumen to liver in group C4, while δ13CFAs of rumen and meat are mostly not statistically different. Different trends in the δ13CFAs of the two groups suggested different FAs fates depending on the diet.

A Native CPP from Rattlesnake with Therapeutic and Theranostic Properties.

The cell-penetrating peptides (CPPs) are characterized by the ability of internalization into cells in vitro and in vivo, and the ability of these peptides can rely on a high content of positive charges, as it is the case of the native CPP crotamine. Crotamine is a polypeptide of about 42 amino acid residues with high content of basic residues as Arg and Lys. Although most of known CPPs are linear peptides, native crotamine from the venom of a South American rattlesnake has a well-defined 3D structure stabilized by three disulfide bonds which guarantee the exposure of side chains of basic amino acids. This 3D structure also protects this amphipathic polypeptide from the degradation even if administered by oral route, therefore, protecting also the biological activities of crotamine. As several different biological properties of crotamine are dependent of cell penetration, the methods mainly employed for analyzing crotamine properties as anthelminthic and antimalarial activities, antimicrobial and antitumor activities, with a unique selective cytotoxic property against actively proliferating cells, as tumor cells, were chosen based on crotamine ability of internalization mediated by its positive charge. This native cationic polypeptide is also able to efficiently carry, with no need of covalent linkage with the cargo, genetic material into cells in vitro and in vivo, suggesting its use in gene therapy. Moreover, the possibility of decorating gold nanoparticles keeping the ability of transfecting cells was demonstrated. More recently, the ability of crotamine to interfere in animal metabolism, inducing browning of adipose tissue and increasing the energy expenditure, and its application in renal therapy was demonstrated. As crotamine also accumulates specifically in tumor cells in vivo, and the potential utility of crotamine as a theranostic agent was then suggested. Therefore, diverse methodologies employed for the characterization and exploration of the therapeutic applications of this promising native CPP for remediation of several pathogenic conditions are presented here.

Metabolic heat production by human and animal populations in cities.

Anthropogenic heating from building energy use, vehicle fuel consumption, and human metabolism is a key term in the urban energy budget equation. Heating from human metabolism, however, is often excluded from urban energy budgets because it is widely observed to be negligible. Few reports for low-latitude cities are available to support this observation, and no reports exist on the contribution of domestic animals to urban heat budgets. To provide a more comprehensive view of metabolic heating in cities, we quantified all terms of the anthropogenic heat budget at metropolitan scale for the world's 26 largest cities, using a top-down statistical approach. Results show that metabolic heat release from human populations in mid-latitude cities (e.g. London, Tokyo, New York) accounts for 4-8% of annual anthropogenic heating, compared to 10-45% in high-density tropical cities (e.g. Cairo, Dhaka, Kolkata). Heat release from animal populations amounts to <1% of anthropogenic heating in all cities. Heat flux density from human and animal metabolism combined is highest in Mumbai-the world's most densely populated megacity-at 6.5 W m-2, surpassing heat production by electricity use in buildings (5.8 W m-2) and fuel combustion in vehicles (3.9 W m-2). These findings, along with recent output from global climate models, suggest that in the world's largest and most crowded cities, heat emissions from human metabolism alone can force measurable change in mean annual temperature at regional scale.

Chloroquine increases phosphorylation of AMPK and Akt in myotubes.

AIMS: There are reports that ataxia telangiectasia mutated (ATM) can activate the AMP-activated protein kinase (AMPK) and also Akt, two kinases that play integral parts in cardioprotection and metabolic function. We hypothesized that chloroquine and resveratrol, both known ATM activators, would also activate AMPK and Akt. MAIN METHODS: Phosphorylation of AMPK and Akt was assessed after C2C12 myotubes were exposed to chloroquine or resveratrol. Additional experiments were done in cells expressing shRNA against ATM or in the presence of the ATM inhibitor KU55933. The effects of chloroquine on intracellular calcium were assessed with the fluorescent probe Calcium Green-1 AM. KEY FINDINGS: 0.5 mM chloroquine increased AMPK phosphorylation by nearly 4-fold (P<0.05), and 0.25 mM chloroquine roughly doubled Akt phosphorylation (P<0.05). Chloroquine also increased autophosphorylation of ATM by ~50% (P<0.05). Resveratrol (0.15 mM) increased AMPK phosphorylation about three-fold (P<0.05) but in contrast to chloroquine sharply decreased Akt phosphorylation. Chloroquine increased AMPK and Akt phosphorylation in myotubes expressing shRNA against ATM that reduced ATM protein levels by about 90%. Likewise, chloroquine-stimulated phosphorylation of AMPK and Akt and resveratrol-stimulated phosphorylation of AMPK were not altered by inhibition of ATM. Chloroquine decreased intracellular calcium by >50% concomitant with a decrease in glucose transport. SIGNIFICANCE: These ATM-independent effects of chloroquine on AMPK and Akt and the additional effect to decrease intracellular calcium are likely to partially underlie the positive metabolic effects of chloroquine that have been reported in the literature.

Considerações sobre os principais indicadores utilizados em estudos de nutrição com ruminantes / Considerations on the main markers used in nutrition studies with rumlnants / Consideraciones acerca de los principales indicadores utilizados en estudios de nutrición con rumiantes

ABSTRACT: In animal metabolism studies, sometimes it's not possible to obtain the desired information in a direct way, and therefore it is necessary to make use of substances designated as markers, which allow the estimative of determined physiological and nutritional parameters. The markers are grouped into internal, which are represented by indigestible materials occurring naturally on a diet, and external markers, which are materials that are either added to the diet or administered orally or intraruminally to the animal. However, in order to be used as a marker, a substance must comply with some essential criteria. There are several problems associated to the use of markers, specially their incomplete recovery in the duodenum or faeces. Each group of markers has its own characteristics, which will defi ne its application. Chromium oxide is the most extensively used external marker, presenting a great wide application, especially because it is easy to use and it cost is low.Among the internal markers, the use of the indigestible fi bre portion of the foods is recommended for its facility to use and has demonstrated reliable and accurate values in several studies. The use of n-alkanes, especially for the intake estimation in grazing animals, has provided quite satisfactory values. Several criteria, like the facility to use and determination must be established to guide the decision by the marker which better adapts to the parameters that will be assessed.KEYWORDS: Markers, animal metabolism, methodology, nutrition

RESUMO: Em estudos de metabolismo animal, muitas vezes, não é possível obter de forma direta a informação desejada, sendo necessário o uso de substâncias denominadas indicadores, possibilitando a estimativa de determinados parâmetros fi siológicos e nutricionais. Os indicadores são divididos em internos, representados por substâncias indigestíveis presentes naturalmente na dieta, ou externos, quando adicionados à dieta ou fornecidos via oral ou ruminal aos animais. Para que uma substância possa ser utilizada como indicador, deve atender a determinados critérios, sendo vários os problemas associados ao seu uso, especialmente a incompleta recuperação do indicador no duodeno ou fezes. Cada grupo de indicadores possui suas características próprias, defi nindo em que situação ele melhor se aplica. O óxido crômico é o indicador externo mais amplamente difundido, apresentando uma grande amplitude de aplicações, associada ainda às vantagens de fácil utilização e baixo custo. Entre os indicadores internos, a utilização da porção da fi bra indigestível dos alimentos vem se destacando pela facilidade de uso e bons resultados apresentados pela literatura. A utilização dos n-alcanos, sobretudo em estimativa de consumo de animais em regime de pastejo, tem apresentado resultados bastante satisfatórios. No momento da escolha, devem ser estabelecidos critérios, como facilidade de uso e determinação, que norteiem a decisão pelo indicador que melhor se adapte aos parâmetros a ser avaliados

RESUMEN: En estudios de metabolismo animal, muchas veces no es posible obtener de forma directa la información deseada, debiéndose entonces, hacer uso de sustancias denominadas indicadores, haciendo posible con eso la estimación de determinados parámetros fi siológicos y nutricionales. Los indicadores son divididos en internos y externos, existiendo una gran variedad de indicadores que deben ser escogidos de acuerdo con la respuesta a ser encontrada. Por tanto, para que una sustancia pueda ser utilizada como indicador, ella debe atender a determinados criterios básicos. Diversos son los problemas asociados al uso de indicadores, especialmente su incompleta recuperación en el duodeno o heces. Cada grupo de indicadores posee sus propias características, defi niéndose en que situación se aplica mejor. El óxido de cromo es el indicador externo mas ampliamente difundido, presentando una grande amplitud de aplicaciones, asociado además a las ventajas de fácil uso y bajo costo. Entre los indicadores internos, la utilización de la porción de la fi bra indigestible de los alimentos fue destacada por la facilidad de uso y de buenos resultados presentados por la literatura. La utilización de n-alcanos, sobre todo en estimaciones de consumo de alimento de animales en régimen de pastoreo presentó resultados bastante satisfactorios. En el momento de elegir el indicador para ser utilizado, deben ser establecidos criterios que norteen la decisión por el indicador que mejor se adecue a los parámetros evaluados y a sus facilidades de uso y determinación.