Journal Articles, Hindawi Press

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https://hdl.handle.net/10919/78797

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Browsing Journal Articles, Hindawi Press by Department "Dairy Science"

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    Hepatic Metabolic, Inflammatory, and Stress-Related Gene Expression in Growing Mice Consuming a Low Dose of Trans-10, cis-12-Conjugated Linoleic Acid
    Li, Jing; Viswanadha, Srikant; Loor, Juan J. (Hindawi, 2012-09-02)
    Dietary trans-10, cis-12-conjugated linoleic acid (trans-10, cis-12-CLA) fed to obese and nonobese rodents reduces body fat but leads to greater liver mass due to steatosis. The molecular mechanisms accompanying such responses remain largely unknown. Our study investigated the effects of chronic low trans-10, cis-12-CLA supplementation on hepatic expression of 39 genes related to metabolism, inflammation, and stress in growing mice. Feeding a diet supplemented with 0.3% trans-10, cis-12-CLA (wt/wt basis) for 6 weeks increased liver mass and concentration of long-chain fatty acids (LCFAs) in liver, while adipose tissue mass decreased markedly. These changes were accompanied by greater expression of genes involved in LCFA uptake (Cd36), lipogenesis, and triacylglycerol synthesis (Acaca, Gpam, Scd, Pck1, Plin2). Expression of these genes was in line with upregulation of the lipogenic transcription factor Srebf1. Unlike previous studies where higher >0.50% of the diet) doses of trans-10, cis-12-CLA were fed, we found greater expression of genes associated with VLDL assembly/secretion (Mttp, Cideb), ketogenesis (Hmgcs2, Bdh1), and LCFA oxidation (Acox1, Pdk4) in response to trans-10, cis-12-CLA. Dietary CLA, however, did not affect inflammation- and stress-related genes. Results suggested that a chronic low dose of dietary CLA increases liver mass and lipid accumulation due to activation of lipogenesis and insufficient induction of LCFA oxidation and VLDL assembly/secretion.
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    A Time Course for Susceptibility to Staphylococcus aureus Respiratory Infection during Influenza in a Swine Model.
    Smith, E. A.; Kumar, S. R.; Deventhiran, Jagadeeswaran; Cecere, Thomas E.; LeRoith, Tanya; McGilliard, M.; Elankumaran, Subbiah; Mullarky, Isis K. (2011)
    Bacterial superinfections following influenza A virus (IAV) are predominant causes of morbidity in humans. The recent emergence of methicillin-resistant Staphylococcus aureus (MRSA) and highly virulent IAV strains has reduced treatment options. Development of an appropriate animal model to study secondary S. aureus infections may provide important information regarding disease pathogenesis. Pigs are natural hosts to both IAV and S. aureus and have respiratory physiology and immune response comparable to humans. To establish a time course of susceptibility to S. aureus after IAV infection, nursery pigs infected intranasally with IAV were challenged with MRSA at different time points. Lung pathology scores and MRSA CFU were evaluated in dual-infected animals after IAV infection. Flow cytometric analysis of bronchoalveolar lavage fluid indicated differences between treatments. These results demonstrate the appropriateness of an intranasal challenge model in nursery pigs for studying the pathogenesis of IAV and S. aureus coinfection and provide insights into the timeframe for susceptibility of IAV-infected pigs to secondary S. aureus infection.