The Relationship of Visceral Adipose Tissue with Markers of Energy Homeostasis Following Weight-Loss

Excess levels of adipose tissue, in particular visceral adipose tissue (VAT), is closely associated with the metabolic syndrome and dysregulation of energy homeostasis. It is hypothesized that leptin resistance results in overconsumption of calories and reduced satiety. Recently, brain derived neurotrophic factor (BDNF), beyond functioning in learning and memory, is shown to play a role in energy homeostasis via its positive satiety effects on the hypothalamus. However, it remains to be elucidated how changes in visceral adipose tissue are associated with changes in circulating leptin and BDNF after weight-loss. PURPOSE: To identify changes in adiposity and circulating leptin and BDNF following a 3-month weight-loss program. METHODS: Sixty-five obese (mean±SEM; age=47.9±1.1 years; BMI=34.5±0.8 kg/m2;), men and women completed a 3-month weight-loss program that consisted of a reduced energy intake of 1200-1500 kcals/day using a high-volume low-calorie diet combined with a progressive walking program to target 300 min/wk. Fasted (12 hr) blood samples were collected at baseline and post-weight-loss (3 months) and assayed for concentrations of glucose, insulin, BDNF, and leptin. Using DXA, total VAT and subcutaneous (SubQ) adipose tissue mass were measured at baseline and post-weight-loss (3 months). To identify significant changes over time, ANOVA with repeated measures was performed with significance set at p\u3c0.05. RESULTS: Following the 3-month weight-loss program, both BMI and HOMA-IR were significantly reduced 9.3% and 49%, respectively. The reduction in BMI and HOMA-IR were matched by a significant reduction in both VAT (-658 g; -33%, p\u3c0.001) and SubQ (-367 g; -17%, p\u3c0.001). Interestingly, leptin was reduced and BDNF was increased by 43% (p\u3c0.001) and 42% (p=0.011), respectively. Linear regression revealed that changes in VAT were associated with changes in leptin (b=0.298, p=0.026), but not with BDNF (b=0.027, p=0.896). CONCLUSION: This study shows that the reduction in VAT, by caloric restriction and physical activity, was associated with the reduction in circulating leptin concentrations, but not with changes in BDNF. Changes in leptin and BDNF may be in part responsible for the normalization of the energy homeostasis observed after weight-loss; however, changes in BDNF may be independent of VAT

The Effect of Gender on Circulating Adipokines during Weight Loss and Weight Maintenance

During obesity, the altered release of adipokines, leptin and adiponectin, have been strongly associated with development of the metabolic syndrome. Treatment with weight loss has been shown to increase adiponectin, in particular high molecular weight (HMW) adiponectin, and reduce circulating leptin levels indicating an increased leptin sensitizing effect. Interestingly, a gender dichotomy has been identified with women generally possessing higher plasma concentrations of both adipokines. Weight loss effects have been well established; however, it remains to be determined how the gender differences in adiponectin and leptin will affect these adipokines during prolonged weight maintenance. PURPOSE: To identify gender differences in adiponectin and leptin concentrations following a 6-month weight loss and weight maintenance program. METHODS: Sixty-five obese (mean±SEM; age=47.9±1.1 years; BMI=34.3±0.7 kg/m2;) adults (M=20, F=45) completed a 3-month weight loss program that consisted of a reduced energy intake of 1200-1500 kcals/day using a high-volume low-calorie diet combined with a progressive walking program to target 300 min/wk. During the 3-month weight maintenance program, participants consumed sufficient calories to maintain weight loss with continued walking to target 300 min/wk. Fasted (12 hr) blood samples were collected at baseline, post- weight loss (3 months), and weight maintenance (6 months) and assayed for glucose, insulin, total and HMW adiponectin, and leptin. To identify significant changes over time and between gender, a repeated measures (time x gender) ANOVA was performed with significance set at P\u3c0.05. Results: At baseline, no significant difference in BMI or HOMA-IR were observed between genders. Following 3 months of weight loss, BMI was significantly reduced 9.9% and 8.5% in men and women, respectively, and BMI remained unchanged through the weight maintenance program. Interestingly, only men demonstrated a significant reduction in HOMA-IR following weight loss. Following weight maintenance in women, HOMA-IR increased slightly such that it was not significantly different than the baseline or weight loss time points. At baseline, women had significantly higher circulating levels of total and HMW adiponectin, and leptin. No significant changes in total or HMW adiponectin were observed over time for either gender. Following weight-loss, leptin concentrations were reduced 49.6% and 39.2% in men and women, respectively. Interestingly, only women demonstrated a transient reduction in leptin through the weight maintenance program. Conclusions: At baseline, we identified the presence of a clear gender dichotomy for total and HMW adiponectin, and leptin concentrations. Despite these significant differences in circulating adipokines at baseline, both men and women responded similarly to a 6-month weight loss and weight maintenance program

HtrA, fatty acids, and membrane protein interplay in Chlamydia trachomatis to impact stress response and trigger early cellular exit

UNLABELLED: Chlamydia trachomatis is an intracellular bacterial pathogen that undergoes a biphasic developmental cycle, consisting of intracellular reticulate bodies and extracellular infectious elementary bodies. A conserved bacterial protease, HtrA, was shown previously to be essential for Chlamydia during the reticulate body phase, using a novel inhibitor (JO146). In this study, isolates selected for the survival of JO146 treatment were found to have polymorphisms in the acyl-acyl carrier protein synthetase gene (aasC). AasC encodes the enzyme responsible for activating fatty acids from the host cell or synthesis to be incorporated into lipid bilayers. The isolates had distinct lipidomes with varied fatty acid compositions. A reduction in the lipid compositions that HtrA prefers to bind to was detected, yet HtrA and MOMP (a key outer membrane protein) were present at higher levels in the variants. Reduced progeny production and an earlier cellular exit were observed. Transcriptome analysis identified that multiple genes were downregulated in the variants especially stress and DNA processing factors. Here, we have shown that the fatty acid composition of chlamydial lipids, HtrA, and membrane proteins interplay and, when disrupted, impact chlamydial stress response that could trigger early cellular exit.IMPORTANCE: Chlamydia trachomatis is an important obligate intracellular pathogen that has a unique biphasic developmental cycle. HtrA is an essential stress or virulence protease in many bacteria, with many different functions. Previously, we demonstrated that HtrA is critical for Chlamydia using a novel inhibitor. In the present study, we characterized genetic variants of Chlamydia trachomatis with reduced susceptibility to the HtrA inhibitor. The variants were changed in membrane fatty acid composition, outer membrane proteins, and transcription of stress genes. Earlier and more synchronous cellular exit was observed. Combined, this links stress response to fatty acids, membrane proteins, and HtrA interplay with the outcome of disrupted timing of chlamydial cellular exit.</p

Comparing the immune response to a novel intranasal nanoparticle PLGA vaccine and a commercial BPI3V vaccine in dairy calves

peer-reviewedBackground There is a need to improve vaccination against respiratory pathogens in calves by stimulation of local immunity at the site of pathogen entry at an early stage in life. Ideally such a vaccine preparation would not be inhibited by the maternally derived antibodies. Additionally, localized immune response at the site of infection is also crucial to control infection at the site of entry of virus. The present study investigated the response to an intranasal bovine parainfluenza 3 virus (BPI3V) antigen preparation encapsulated in PLGA (poly dl-lactic-co-glycolide) nanoparticles in the presence of pre-existing anti-BPI3V antibodies in young calves and comparing it to a commercially available BPI3V respiratory vaccine. Results There was a significant (P < 0.05) increase in BPI3V-specific IgA in the nasal mucus of the BPI3V nanoparticle vaccine group alone. Following administration of the nanoparticle vaccine an early immune response was induced that continued to grow until the end of study and was not observed in the other treatment groups. Virus specific serum IgG response to both the nanoparticle vaccine and commercial live attenuated vaccine showed a significant (P < 0.05) rise over the period of study. However, the cell mediated immune response observed didn’t show any significant rise in any of the treatment groups. Conclusion Calves administered the intranasal nanoparticle vaccine induced significantly greater mucosal IgA responses, compared to the other treatment groups. This suggests an enhanced, sustained mucosal-based immunological response to the BPI3V nanoparticle vaccine in the face of pre-existing antibodies to BPI3V, which are encouraging and potentially useful characteristics of a candidate vaccine. However, ability of nanoparticle vaccine in eliciting cell mediated immune response needs further investigation. More sustained local mucosal immunity induced by nanoparticle vaccine has obvious potential if it translates into enhanced protective immunity in the face of virus outbreak

Numerical simulations of the Warm-Hot Intergalactic Medium

In this paper we review the current predictions of numerical simulations for the origin and observability of the warm hot intergalactic medium (WHIM), the diffuse gas that contains up to 50 per cent of the baryons at z~0. During structure formation, gravitational accretion shocks emerging from collapsing regions gradually heat the intergalactic medium (IGM) to temperatures in the range T~10^5-10^7 K. The WHIM is predicted to radiate most of its energy in the ultraviolet (UV) and X-ray bands and to contribute a significant fraction of the soft X-ray background emission. While O VI and C IV absorption systems arising in the cooler fraction of the WHIM with T~10^5-10^5.5 K are seen in FUSE and HST observations, models agree that current X-ray telescopes such as Chandra and XMM-Newton do not have enough sensitivity to detect the hotter WHIM. However, future missions such as Constellation-X and XEUS might be able to detect both emission lines and absorption systems from highly ionised atoms such as O VII, O VIII and Fe XVII.Comment: 18 pages, 5 figures, accepted for publication in Space Science Reviews, special issue "Clusters of galaxies: beyond the thermal view", Editor J.S. Kaastra, Chapter 14; work done by an international team at the International Space Science Institute (ISSI), Bern, organised by J.S. Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke

'To live and die [for] Dixie': Irish civilians and the Confederate States of America

Around 20,000 Irishmen served in the Confederate army in the Civil War. As a result, they left behind, in various Southern towns and cities, large numbers of friends, family, and community leaders. As with native-born Confederates, Irish civilian support was crucial to Irish participation in the Confederate military effort. Also, Irish civilians served in various supporting roles: in factories and hospitals, on railroads and diplomatic missions, and as boosters for the cause. They also, however, suffered in bombardments, sieges, and the blockade. Usually poorer than their native neighbours, they could not afford to become 'refugees' and move away from the centres of conflict. This essay, based on research from manuscript collections, contemporary newspapers, British Consular records, and Federal military records, will examine the role of Irish civilians in the Confederacy, and assess the role this activity had on their integration into Southern communities. It will also look at Irish civilians in the defeat of the Confederacy, particularly when they came under Union occupation. Initial research shows that Irish civilians were not as upset as other whites in the South about Union victory. They welcomed a return to normalcy, and often 'collaborated' with Union authorities. Also, Irish desertion rates in the Confederate army were particularly high, and I will attempt to gauge whether Irish civilians played a role in this. All of the research in this paper will thus be put in the context of the Drew Gilpin Faust/Gary Gallagher debate on the influence of the Confederate homefront on military performance. By studying the Irish civilian experience one can assess how strong the Confederate national experiment was. Was it a nation without a nationalism

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Mobilizing Crop Biodiversity

Over the past 70 years, the world has witnessed extraordinary growth in crop productivity, 1 enabled by a suite of technological advances, including higher yielding crop varieties, improved farm management, synthetic agrochemicals, and agricultural mechanization. While this “Green Revolution” intensified crop production, and is credited with reducing famine and malnutrition, its benefits were accompanied by several undesirable collateral effects (Pingali, 2012). These include a narrowing of agricultural biodiversity, stemming from increased monoculture and greater reliance on a smaller number of crops and crop varieties for the majority of our calories. This reduction in diversity has created vulnerabilities to pest and disease epidemics, climate variation, and ultimately to human health (Harlan, 1972). The value of crop diversity has long been recognized (Vavilov, 1992). A global system of genebanks (e.g.www.genebanks.org/genebanks/) was established in the 1970s to preserve the abundant genetic variation found in traditional “landrace” varieties of crops and in crop wild relatives (Harlan, 1972). While preserving crop variation is a critical first step, the time has come to make use of this variation to breed more resilient crops. The DivSeek International Network (https://divseekintl.org/) is a scientific, not-for profit organization that aims to accelerate such effort

Spatial variation of trace metals within intertidal beds of native mussels (Mytilus edulis) and non-native Pacific oysters (Crassostrea gigas): implications for the food web?

Abstract Pollution is of increasing concern within coastal regions and the prevalence of invasive species is also rising. Yet the impact of invasive species on the distribution and potential trophic transfer of metals has rarely been examined. Within European intertidal areas, the non-native Pacific oyster (Crassostrea gigas) is becoming established, forming reefs and displacing beds of the native blue mussel (Mytilus edulis). The main hypothesis tested is that the spatial pattern of metal accumulation within intertidal habitats will change should the abundance and distribution of C. gigas continue to increase. A comparative analysis of trace metal content (cadmium, lead, copper and zinc) in both species was carried out at four shores in south-east England. Metal concentrations in bivalve and sediment samples were determined after acid digestion by inductively coupled plasma-optical emission spectrometry. Although results showed variation in the quantities of zinc, copper and lead (mg m-2) in the two bivalve species, differences in shell thickness are also likely to influence the feeding behaviour of predators and intake of metals. The availability and potential for trophic transfer of metals within the coastal food web, should Pacific oysters transform intertidal habitats, is discussed

Validation of elemental and isotopic abundances in late-M spectral types with the benchmark HIP 55507 AB system

M dwarfs are common host stars to exoplanets but often lack atmospheric abundance measurements. Late-M dwarfs are also good analogs to the youngest substellar companions, which share similar $T_{\rm eff}\sim2300-2800~K$. We present atmospheric analyses for the M7.5 companion HIP 55507 B and its K6V primary star with Keck/KPIC high-resolution ($R\sim35,000$) $K$ band spectroscopy. First, by including KPIC relative radial velocities between the primary and secondary in the orbit fit, we improve the dynamical mass precision by 60% and find $M_B=88.0_{-3.2}^{+3.4}$ $M_{\rm Jup}$, putting HIP 55507 B above the stellar-substellar boundary. We also find that HIP 55507 B orbits its K6V primary star with $a=38^{+4}_{-3}$ AU and $e=0.40\pm0.04$. From atmospheric retrievals of HIP 55507 B, we measure $\rm [C/H]=0.24\pm0.13$, $\rm [O/H]=0.15\pm0.13$, and $\rm C/O=0.67\pm0.04$. Moreover, we strongly detect $\rm ^{13}CO$ ($7.8\sigma$ significance) and tentatively detect $\rm H_2^{18}O$ ($3.7\sigma$ significance) in companion's atmosphere, and measure $\rm ^{12}CO/^{13}CO=98_{-22}^{+28}$ and $\rm H_2^{16}O/H_2^{18}O=240_{-80}^{+145}$ after accounting for systematic errors. From a simplified retrieval analysis of HIP 55507 A, we measure $\rm ^{12}CO/^{13}CO=79_{-16}^{+21}$ and $\rm C^{16}O/C^{18}O=288_{-70}^{+125}$ for the primary star. These results demonstrate that HIP 55507 A and B have consistent $\rm ^{12} C/^{13}C$ and $\rm ^{16}O/^{18}O$ to the $<1\sigma$ level, as expected for a chemically homogeneous binary system. Given the similar flux ratios and separations between HIP 55507 AB and systems with young, substellar companions, our results open the door to systematically measuring $\rm ^{13}CO$ and $\rm H_2^{18}O$ abundances in the atmospheres of substellar or even planetary-mass companions with similar spectral types.Comment: Accepted to ApJ, 28 pages, 14 figure