The association between ownership of common household devices and obesity and diabetes in high,middle and low income countries

Background:

Household devices (e.g., television, car, computer) are common in high income countries, and their use has been linked to obesity and type 2 diabetes mellitus. We hypothesized that device ownership is associated with obesity and diabetes and that these effects are explained through reduced physical activity, increased sitting time and increased energy intake.

Methods:

We performed a cross-sectional analysis using data from the Prospective Urban Rural Epidemiology study involving 153 996 adults from high, upper-middle, lower-middle and low income countries. We used multilevel regression models to account for clustering at the community and country levels.

Results:

Ownership of a household device increased from low to high income countries (4% to 83% for all 3 devices) and was associated with decreased physical activity and increased sitting, dietary energy intake, body mass index and waist circumference. There was an increased odds of obesity and diabetes with the ownership of any 1 household device compared to no device ownership (obesity: odds ratio [OR] 1.43, 95% confidence interval [CI] 1.32–1.55; diabetes: OR 1.38, 95% CI 1.28–1.50). Ownership of a second device increased the odds further but ownership of a third device did not. Subsequent adjustment for lifestyle factors modestly attenuated these associations. Of the 3 devices, ownership of a television had the strongest association with obesity (OR 1.39, 95% CI 1.29–1.49) and diabetes (OR 1.33, 95% CI 1.23–1.44). When stratified by country income level, the odds of obesity and diabetes when owning all 3 devices was greatest in low income countries (obesity: OR 3.15, 95% CI 2.33–4.25; diabetes: OR 1.97, 95% CI 1.53–2.53) and decreased through country income levels such that we did not detect an association in high income countries.

Interpretation:

The ownership of household devices increased the likelihood of obesity and diabetes, and this was mediated in part by effects on physical activity, sitting time and dietary energy intake. With increasing ownership of household devices in developing countries, societal interventions are needed to mitigate their effects on poor health.The increasing global prevalence of obesity and type 2 diabetes mellitus has been driven predominantly by increases in high income countries.^1,2 However, increases are expected in low and middle income countries, due in part to rapid development and industrialization.Proximal determinants of obesity and diabetes include energy expenditure and intake;^3–5 however, the upstream factors are complex and entail numerous environmental factors. Of these, the increased use of common household devices (e.g., televisions, cars, computers) has been linked to increased sitting, decreased physical activity, obesity, metabolic syndrome and diabetes.^6–12 Time spent watching television has also been linked to poor diet¹³ and increased caloric intake.¹⁴ However, these findings are based on studies in high income countries where the ownership of these devices is common.^15,16 In low and middle income countries, such household devices are less prevalent, but their prevalence is rapidly increasing. Studies in countries with greater variability in the ownership of household devices are needed to understand the full effect of owning such devices on the risk of obesity and diabetes.We hypothesized that the ownership of a television, car or computer would be associated with an increased risk of obesity and diabetes and that these effects would be explained by reduced physical activity, increased sitting time and increased energy intake.     

Over‐expression of secreted proteins from mammalian cell lines

Secreted mammalian proteins require the development of robust protein over‐expression systems for crystallographic and biophysical studies of protein function. Due to complex disulfide bonds and distinct glycosylation patterns preventing folding and expression in prokaryotic expression hosts, many secreted proteins necessitate production in more complex eukaryotic expression systems. Here, we elaborate on the methods used to obtain high yields of purified secreted proteins from transiently or stably transfected mammalian cell lines. Among the issues discussed are the selection of appropriate expression vectors, choice of signal sequences for protein secretion, availability of fusion tags for enhancing protein stability and purification, choice of cell line, and the large‐scale growth of cells in a variety of formats.     

Tie2 and Eph Receptor Tyrosine Kinase Activation and Signaling

The Eph and Tie cell surface receptors mediate a variety of signaling events during development and in the adult organism. As other receptor tyrosine kinases, they are activated on binding of extracellular ligands and their catalytic activity is tightly regulated on multiple levels. The Eph and Tie receptors display some unique characteristics, including the requirement of ligand-induced receptor clustering for efficient signaling. Interestingly, both Ephs and Ties can mediate different, even opposite, biological effects depending on the specific ligand eliciting the response and on the cellular context. Here we discuss the structural features of these receptors, their interactions with various ligands, as well as functional implications for downstream signaling initiation. The Eph/ephrin structures are already well reviewed and we only provide a brief overview on the initial binding events. We go into more detail discussing the Tie-angiopoietin structures and recognition.     

Surviving winter hypoxia: behavioral adaptations of fishes in a northern Wisconsin winterkill lake

Synopsis Winterkill lakes often have a characteristic fish community, presumably composed of species able to survive winter hypoxia. Our research on a small winterkill lake in northern Wisconsin indicates that fishes common in winterkill lakes have behavioral adaptations for tolerating or avoiding winter hypoxia. We examined the distribution of fishes within the lake during one winter (December through May), and fish migrations into and out of the lake for two consecutive years. As DO within the lake declined in late fall, adult-sized fishes of four species, brook stickleback, finescale dace, redbelly dace, and fathead minnow, moved to the ice-water interface where DO levels were highest. Stickleback, and to a lesser extent, fathead minnows, also moved toward the more highly oxygenated water near the inlet. During the first year, young-of-the-year fishes of blacknose shiner, Iowa darter, redbelly dace, and fathead minnow, avoided hypoxic conditions by emigrating from the lake via the outlet stream in late fall and early winter while DO within the lake was still relatively high. Blacknose shiner, redbelly dace, and fathead minnow returned to the lake in spring. Almost no fishes were trapped leaving the lake in the second fall-winter season. Central mudminnows neither moved to the ice-water interface nor emigrated from the lake as DO dropped. Mudminnows survive winter hypoxia by breathing oxygen-containing bubbles trapped beneath the ice. These relatively simple behavioral adaptations allow fishes to survive or avoid hypoxic conditions lethal to other species and may help explain the consistency in fish communities of winterkill lakes.     

The control of nitrate and ammonium concentrations in a coral reef lagoon

One Tree Reef lagoon is surrounded by an emergent rim which restricts exchange between lagoonal waters and the surrounding ocean. For this reason, the loss rate of dissolved inorganic nitrogen (DIN) through mixing processes is slow in the central lagoon compared to rates of advective input, uptake, regeneration and loss to the atmosphere. We present some hypotheses concerning the importance of these fluxes to the observed patterns of concentration of nitrate+nitrite and ammonium. A scaling analysis of these fluxes indicates that the relative influence of advection across the windward reef crest on lagoonal concentrations changes with season and differs for the two forms of DIN. Advective flux, dominated by DIN derived from production on the algal pavements of the reef crest, is significant in controlling DIN concentration in the peripheral regions of the lagoon. Loss to the atmosphere is a more important flux from the nitrate+nitrite pool in the centre of the lagoon, particularly in summer. Regeneration is a significant input to the ammonium pool of the central lagoon in winter. The relative magnitudes of all fluxes are more similar to each other in the summer than the winter, indicating the potential for shifts in the dominance hierarchy at small time and space scales. One form of DIN in One Tree Reef lagoonal waters (nitrate+nitrite) is controlled by input and another (ammonium) by recycling as well as input. The relative importance of these fluxes changes as a result of temperature pertubations at the physiological level as well as the rate of water turnover at the system level. It is proposed that the degree of consistency of the seasonal concentration patterns is a function of the period, rather than the amplitude of the temporal oscillations in the fluxes controlling these concentrations. This has important implications for sampling strategies. This paper provides a conceptual framework for hypothesis testing at a manageable scale, in the context of ecosystem function.     

Evidence for glutathione peroxidase activities in cultured plant cells

Extracts from cultured plant cells of spinach, maize and sycamore and from Lemna plants contain detectable glutathione peroxidase activity, using either hydrogen peroxide or t-butyl hydroperoxide as substrates. Using extracts from cultured maize cells, two peaks of glutathione peroxidase activity could be resolved by a combination of gel filtration and ion exchange chromatography. One peak was eluted along with glutathione transferase activity; the second was distinct from both glutathione transferase and ascorbic acid peroxidase, and was active with both hydrogen peroxide and organic hydroperoxides. It seems likely that at least two enzymes with glutathione peroxidase activity exist in higher plant cells.     

Ordered Synthesis of Proteins During Outgrowth of Spores of Bacillus cereus

The onset of macromolecular synthesis in activated spores of Bacillus cereus occurs under conditions in which the amino acids and nucleotides to be used for building proteins and nucleic acids must be derived only from stored pools and turnover of macromolecules of the spore. Upon addition of the factors required to initiate germination, (14)C-uracil is incorporated with a lag of 30 to 60 sec; (14)C-amino acids, with a lag of 3 to 4 min. The progression of protein synthesis during germination has been studied, and the results suggest three phases of development of the protein synthetic pattern of these germinating spores. The initial synthesis which occurs during the early part of germination is limited to only a few proteins. When the initiated spores are put in a medium containing a complete set of growth requirements and outgrowth ensues, the cells synthesize a large number of different proteins so that the distribution of radioactivity into different fractions appears to be a continuous function. At a later time during outgrowth, the distribution of synthetic rates among the different proteins becomes more representative of that found during vegetative growth.     

Untersuchungen über das Gefäss-system des Pankreasläppchens bei verschiedenen Säugern mit besonderer Berücksichtigung der Kapillarknäuel der Langerhansschen Inseln

Cell and Tissue Research - Untersuchungen an den arteriell injizierten Bauchspeicheldrüsen von Pferd, Schwein, Hund, Kaninchen, Meerschweinchen, Ratte und Maus über den feineren...     

Mangrove-sponge associations: a possible role for tannins

A positive correlation between sponge coverage and tannin concentrations in prop roots of Rhizophora mangle L. has previously been reported. However, the ecological role of tannins within the mangrove sponge association remains speculative. This study investigated whether tannins play a role in sponge recruitment and assessed tannin and polyphenol production in R. mangle roots in response to sponge colonization. We demonstrated in a field experiment using artificial substrates with different tannin concentrations that tannins are positively involved in larval recruitment of the sponge Tedania ignis and that roots significantly enhanced tannin and polyphenolic content in response to natural and experimental sponge fouling. Differential recruitment in response to tannins may have been the result of a behavioral response in sponge larvae. It is also possible that tannins affected the structure of the fouling microbial biofilm on the artificial substrate, or tannins affected the post-settlement dynamics of sponge recruits. Elevations in concentrations of tannins and polyphenolic compounds upon coverage with sponges, combined with differential recruitment of T. ignis in response to differences in tannin concentrations, may indicate a positive feedback in recruitment. This may in part explain the typical heterogeneity in sponge coverage and community composition among roots.     

Induction of tumour necrosis factor by staphylococcal toxic shock toxin 1

Abstract Staphylococcal toxic shock syndrome toxin 1 (TSST1) induced the release of tumour necrosis factor (TNF) from human and rabbit monocytes in vitro. Nanogram amounts of TSST1 were sufficient to induce TNF release. There was considerable variation in response between cells from different rabbits and different donors. Rabbit monocytes were slightly more sensitive to TSST1 than were human monocytes. Release of TNF in vivo could explain many of the symptoms of toxic shock syndrome.