The effects of reality television on weight bias: an examination of The Biggest Loser

Weight-loss reality shows, a popular form of television programming, portray obese individuals and their struggles to lose weight. While the media is believed to reinforce obesity stereotypes and contribute to weight stigma, it is not yet known whether weight-loss reality shows have any effect on weight bias. The goal of this investigation was to examine how exposure to 40-min of The Biggest Loser impacted participants' levels of weight bias. Fifty-nine participants (majority of whom were white females) were randomly assigned to either an experimental (one episode of The Biggest Loser) or control (one episode of a nature reality show) condition. Levels of weight bias were measured by the Implicit Associations Test (IAT), the Obese Person Trait Survey (OPTS), and the Anti-fat Attitudes scale (AFA) at baseline and following the episode viewing (1 week later). Participants in The Biggest Loser condition had significantly higher levels of dislike of overweight individuals and more strongly believed that weight is controllable after the exposure. No significant condition effects were found for implicit bias or traits associated with obese persons. Exploratory analyses examining moderation of the condition effect by BMI and intention to lose weight indicated that participants who had lower BMIs and were not trying to lose weight had significantly higher levels of dislike of overweight individuals following exposure to The Biggest Loser compared to similar participants in the control condition. These results indicate that anti-fat attitudes increase after brief exposure to weight-loss reality television.     

Optimal production of L-threo-2,3-dihydroxyphenylserine (L-threo-DOPS) on a large scale by diastereoselectivity-enhanced variant of L-threonine aldolase expressed in Escherichia coli

This study examined the efficient production and optimal separation procedures for pure L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) from a mixture of diastereomers synthesized by whole-cell aldol condensation reaction, harboring diastereoselectivity-enhanced L-threonine aldolase in Escherichia coli JM109. The addition of the reducing agent sodium sulfite was found to stimulate the production of L-threo-DOPS without affecting the diastereoselectivity ratio, especially at the 50 mM concentration. The optimal pH for diastereoselective synthesis was 6.5. The addition of Triton X-100 also strongly affected the synthesis yield, showing the highest conversion yield at a 0.75% concentration; however, the diastereoselectivity of the L-threonine aldolase was not affected. Lowering the temperature to 10°C did not significantly affect the diastereoselectiviy without affecting the synthesis rate. At the optimized conditions, a mixture of L-threo-DOPS and L-erythro-DOPS was synthesized by diastereoselectivity-enhanced L-threonine aldolase from E. coli in a continuous process for 100 hr, yielding an average of 4.0 mg/mL of L-threo-DOPS and 60% diastereoselectivity (de), and was subjected to two steps of ion exchange chromatography. The optimum separation conditions for the resin and solvent were evaluated in which it was found that a two-step process with the ion-exchange resin Dowex 50 W × 8 and activated carbon by washing with 0.5 N acetic acid was sufficient to separate the L-threo-DOPS. By using two-step ion-exchange chromatography, synthesized high-purity L-threo-DOPS of up to 100% was purified with a yield of 71%. The remaining substrates, glycine and 3,4-dihydroxybenzaldehyde, were recovered successfully with a yield of 71.2%. Our results indicate this potential procedure as an economical purification process for the synthesis and purification of important L-threo-DOPS at the pharmaceutical level.     

Chitinibacter suncheonensis sp. nov., a chitinolytic bacterium from a mud flat in Suncheon Bay

A chitinolytic bacterium, designated strain SK16^T, was isolated from a mud flat in Suncheon Bay, Republic of Korea. Strain SK16^T is Gram-negative, strictly aerobic, motile by a polar flagellum, and short rod-shaped. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain belonged to the genus Chitinibacter and was most closely related to Chitinibacter tainanensis S1^T (98.2% similarity). DNA-DNA hybridization analyses showed a low association value of 20.45±4.08% between them. The major cellular fatty acids, the G+C content of the genomic DNA, and the predominant quinone of the strain were summed feature 3 (iso-C_15:0 2-OH and/or C_16:1 ω7c; 50.5%) and C_12:0 (12.5%), 52.26 mol%, and Q-8, respectively. Based on the phylogenetic, chemotaxonomic, and phenotypic properties, strain SK16^T represents a novel species of the genus Chitinibacter, for which the name Chitinibacter suncheonensis sp. nov. is proposed. The type strain is SK16^T (=KCTC 23839^T =DSM 25421^T).     

Induction of endothelial apoptosis by 4-hydroxyhexenal.

Lipid peroxidation and its products such as 4-hydroxy-2-nonenal (HNE) and 4-hydroxyhexenal (HHE) are known to affect redox balance during aging and various degenerative processes, including vascular dysfunction. Deterioration of the endothelial cells that line the vascular wall is known to be an underlying cause of vascular dysfunction. At present, little is known about the mechanism by which HHE induces endothelial cell death (i.e. apoptosis), although HNE-induced apoptotic cell death has been reported. The aim of this study was to determine whether apoptosis induced by HHE in endothelial cells involves peroxynitrite (ONOO(-)). Our results show that in endothelial cells HHE triggers apoptotic cell death by inducing apoptotic Bax coupled with a decrease in anti-apoptotic Bcl-2. Results show that HHE induces reactive oxygen species (ROS), nitric oxide, and ONOO(-) generation, leading to redox imbalance. Furthermore, the antioxidant N-acetyl cysteine, ROS scavenger, and penicillamine, an ONOO(-) scavenger, were found to block HHE-mediated apoptosis. We used confocal laser microscopy to estimate the ability of these inhibitors to attenuate HHE-induced intracellular ONOO(-) levels thus confirming the oxidative mediation of apoptosis in endothelial cells. These findings strongly suggest that accumulated HHE triggers reactive species-mediated endothelial apoptosis, leading to vascular dysfunction as well as vascular aging. During aging, increased lipid peroxidation and its associated production of HHE may exacerbate the weakened redox balance, leading to various chronic degenerative processes including vascular dysfunction.     

Dopamine signaling in food addiction: role of dopamine D2 receptors

Dopamine (DA) regulates emotional and motivational behavior through the mesolimbic dopaminergic pathway. Changes in DA signaling in mesolimbic neurotransmission are widely believed to modify reward-related behaviors and are therefore closely associated with drug addiction. Recent evidence now suggests that as with drug addiction, obesity with compulsive eating behaviors involves reward circuitry of the brain, particularly the circuitry involving dopaminergic neural substrates. Increasing amounts of data from human imaging studies, together with genetic analysis, have demonstrated that obese people and drug addicts tend to show altered expression of DA D2 receptors in specific brain areas, and that similar brain areas are activated by food-related and drug-related cues. This review focuses on the functions of the DA system, with specific focus on the physiological interpretation and the role of DA D2 receptor signaling in food addiction. [BMB Reports 2013; 46(11): 519-526]     

Characterization of Aminopeptidase P from the Unicellular Cyanobacterium <Emphasis Type="Italic">Synechocystis</Emphasis> sp. PCC6803

The PepP protein has been purified in vitro and characterized for the first time. It is encoded by the sll0136 gene of the unicellular cyanobacterium Synechocystis sp. PCC6803. It is established that the PepP protein is a Mn²⁺-dependent Xaa-Pro-specific aminopeptidase. The protein in the reaction of hydrolysis of the fluorescent peptide Lys(N-Abz)-Pro-Pro-pNA has a maximal activity at pH 7.6 and 32°C.     

Designing Redox‐Stable Cobalt–Polypyridyl Complexes for Redox Flow Batteries: Spin‐Crossover Delocalizes Excess Charge

Redox‐active organometallic molecules offer a promising avenue for increasing the energy density and cycling stability of redox flow batteries. The molecular properties change dramatically as the ligands are functionalized and these variations allow for improving the solubility and controlling the redox potentials to optimize their performance when used as electrolytes. Unfortunately, it has been difficult to predict and design the stability of redox‐active molecules to enhance cyclability in a rational manner, in part because the relationship between electronic structure and redox behavior has been neither fully understood nor systematically explored. In this work, rational strategies for exploiting two common principles in organometallic chemistry for enhancing the robustness of pseudo‐octahedral cobalt–polypyridyl complexes are developed. Namely, the spin‐crossover between low and high‐spin states and the chelation effect emerging from replacing three bidentate ligands with two tridentate analogues. Quantum chemical models are used to conceptualize the approach and make predictions that are tested against experiments by preparing prototype Co‐complexes and profiling them as catholytes and anolytes. In good agreement with the conceptual predictions, very stable cycling performance over 600 cycles is found.     

Development of a diagnostic system for detection of specific antibodies and antigens against Middle East respiratory syndrome coronavirus

Middle East respiratory syndrome coronavirus (MERS‐CoV) is a single‐stranded RNA virus that causes severe respiratory disease in humans with a high fatality rate. Binding of the receptor binding domain (RBD) of the spike (S) glycoprotein to dipeptidyl peptidase 4 is the critical step in MERS‐CoV infection of a host cell. No vaccines or clinically applicable treatments are currently available for MERS‐CoV. Therefore, rapid diagnosis is important for improving patient outcomes through prompt treatment and protection against viral outbreaks. In this study, the aim was to establish two ELISA systems for detecting antigens and antibodies against MERS‐CoV. Using a recombinant full‐length S protein, an indirect ELISA was developed and found to detect MERS‐CoV‐specific antibodies in animal sera and sera of patient with MERS. Moreover, MAbs were induced with the recombinant S protein and RBD and used for sandwich ELISA to detect the MERS‐CoV S protein. Neither ELISA system exhibited significant intra‐assay or inter‐assay variation, indicating good reproducibility. Moreover, the inter‐day precision and sensitivity were adequate for use as a diagnostic kit. Thus, these ELISAs can be used clinically to diagnose MERS‐CoV.

     

Novel nuclear targeting coiled-coil protein of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> showing Ca<Superscript>2+</Superscript>-independent,Mg<Superscript>2+</Superscript>-dependent DNase I activity

HP0059, an uncharacterized gene of Helicobacter pylori, encodes a 284-aa-long protein containing a nuclear localization sequence (NLS) and multiple leucine-rich heptad repeats. Effects of HP0059 proteins in human stomach cells were assessed by incubation of recombinant HP0059 proteins with the AGS human gastric carcinoma cell line. Wild-type HP0059 proteins showed cytotoxicity in AGS cells in a concentration-dependent manner, whereas NLS mutant protein showed no effect, suggesting that the cytotoxicity is attributed to host nuclear localization. AGS cells transfected with pEGFP-HP0059 plasmid showed strong GFP signal merged to the chromosomal DNA region. The chromosome was fragmented into multiple distinct dots merged with the GFP signal after 12 h of incubation. The chromosome fragmentation was further explored by incubation of AGS chromosomal DNA with recombinant HP0059 proteins, which leaded to complete degradation of the chromosomal DNA. HP0059 protein also degraded circular plasmid DNA without consensus, being an indication of DNase I activity. The DNase was activated by MgCl₂, but not by CaCl₂. The activity was completely blocked by EDTA. The optimal pH and temperature for DNase activity were 7.0–8.0 and 55°C, respectively. These results indicate that HP0059 possesses a novel DNase I activity along with a role in the genomic instability of human gastric cells, which may result in the transformation of gastric cells.