Differential sensitivities of bone marrow, spleen and thymus to genotoxicity induced by environmentally relevant concentrations of arsenite

It is known in humans and mouse models, that drinking water exposures to arsenite (As+3) leads to immunotoxicity. Previously, our group showed that certain types of immune cells are extremely sensitive to arsenic induced genotoxicity. In order to see if cells from different immune organs have differential sensitivities to As+3, and if the sensitivities correlate with the intracellular concentrations of arsenic species, male C57BL/6J mice were dosed with 0, 100 and 500 ppb As+3 via drinking water for 30 d. Oxidation State Specific Hydride Generation-Cryotrapping- Inductively Coupled Plasma- Mass Spectrometry (HG- CT- ICP- MS) was applied to analyze the intracellular arsenic species and concentrations in bone marrow, spleen and thymus cells isolated from the exposed mice. A dose-dependent increase in intracellular monomethylarsonous acid (MMA+3) was observed in both bone marrow and thymus cells, but not spleen cells. The total arsenic and MMA+3 levels were correlated with an increase in DNA damage in bone marrow and thymus cells. An in vitro treatment of 5, 50 and 500 nM As+3 and MMA+3 revealed that bone marrow cells are most sensitive to As+3 treatment, and MMA+3 is more genotoxic than As+3. These results suggest that the differential sensitivities of the three immune organs to As+3 exposure are due to the different intracellular arsenic species and concentrations, and that MMA+3 may play a critical role in immunotoxicity

Polymerization of bis(triethoxysilyl)ethenes. The impact of substitution geometry on the formation of ethenyl- and vinylidene-bridged polysilsesquioxanes

Preparation of organically-bridged polysilsesquioxanes has been achieved by polymerizing organic monomers with two or more trialkoxysilyl groups per monomer repeat unit. The nature of the organic bridging group has been shown to strongly impact the final properties (surface area, pore size, and thermal stability) of the end product. For example, rigid arylene bridging groups have been shown to give rise to materials with high surface areas with a relatively large contribution from micropores (< 20 {angstrom}). The length of alkylene-bridging groups can be used to control the size and dispersity of pores in hydrocarbon-bridged xerogels. In this study, the authors have examined the preparation of ethylene-bridged polysilsesquioxanes from the E-(1) and Z-(2) isomers of 1,2-bis(triethoxysilyl)ethene and vinylidene-bridged polysilsesquioxanes from 1,1-bis(triethoxysilyl)ethene-(3). This study was intended to determine the effects of substitution geometry about the carbon-carbon double bond on the condensation chemistry of the monomers and on the resulting architectures of the final materials

Development and testing of the BONES physical activity survey for young children

<p>Abstract</p> <p>Background</p> <p>Weight-bearing and high intensity physical activities are particularly beneficial for stimulating bone growth in children given that bone responds favorably to mechanical load. While it is important to assess the contribution and impact of weight-bearing physical activity on health outcomes, measurement tools that quantify and provide information on these activities separately from overall physical activity are limited. This study describes the development and evaluation of a pictorial physical activity survey (PAS) that measures children's participation and knowledge of high-intensity, weight-bearing ("bone smart") physical activity.</p> <p>Methods</p> <p>To test reliability, two identical sets of the PAS were administered on the same day to 41 children (mean age 7.1 ± 0.8 years; 63% female) and compared. To test validity, accelerometry data from 40 children (mean age 7.7 ± 0.8 years; 50% female) were compared to data provided by the PAS. Agreements between categorical and ordinal items were assessed with Kappa statistics; agreements between continuous indices were assessed with Spearman's correlation tests.</p> <p>Results</p> <p>The subjects produced reliable results in all 10 physical activity participation items (κ range: 0.36-0.73, all p < 0.05), but less reliable in answering if the physical activities were "bone smart" (κ range: -0.04-0.66). Physical activity indices, including metabolic equivalent time and weight-bearing factors, were significant in test-retest analyses (Spearman's <it>r </it>range: 0.57-0.74, all p < 0.001). Minutes of very vigorous activity from the accelerometer were associated with the self-reported weight-bearing activity, moderate-high, and high activity scores from the PAS (Spearman's <it>r </it>range: 0.47-0.48, all p < 0.01). However, accelerometer counts, counts per minute, and minutes of moderate-vigorous and vigorous activity were not associated with the PAS scores.</p> <p>Conclusions</p> <p>Together, the results of these studies suggest that the PAS has acceptable test-retest reliability, but limited validity for early elementary school children. This survey demonstrates a first step towards developing a questionnaire that measures high intensity, weight-bearing activity in schoolchildren.</p

Types of interventions targeting dietary, physical activity and weight-related outcomes among university students : a systematic review of systematic reviews

Belogianni, Katerina - ORCID 0000-0002-3634-7861 https://orcid.org/0000-0002-3634-7861Item previously deposited in Kingston University repository on 17 April 2019 at: http://eprints.kingston.ac.uk/id/eprint/43127Item not available in this repository.A plethora of studies aiming to improve dietary, physical activity (PA), and weight-related (WR) outcomes among university students have been implemented and summarized in a series of systematic reviews, with unclear conclusions regarding their effectiveness. This overview aims to identify systematic reviews and meta-analyses of studies aiming to improve health outcomes in university students, to assess their methodological quality, to identify the different types of interventions used and outcomes assessed, and to estimate their overall effect. Four electronic databases were searched until 19 March, 2018 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The identified reviews were described and their methodological quality was rated. The studies of reviews were investigated to identify the different types of interventions used and outcomes assessed. Effectiveness was assessed by measuring the overall number of improved outcomes out of the total number of outcomes reported. As a result, 8 reviews were identified targeting food sales (n = 2), dietary (n = 3), PA (n = 1), WR (n = 1), or all outcomes (n = 1). The methodological quality of the reviews was moderate (n = 5) to low (n = 3). In all, the reviews included 122 studies, of which 36 used an environmental, 51 a face-to-face, 30 an e-intervention, and 5 a combined approach. Environmental interventions improved a moderate number of food sales (32 of 61) and dietary intake (22 of 47) outcomes. Face-to-face interventions improved a high number of dietary cognitive outcomes (15 of 18), a moderate number of dietary intake (28 of 65) and WR (11 of 18) outcomes, and a low number of PA behavioral (22 of 69) and cognitive (2 of 14) outcomes. E-interventions improved a high number of dietary cognitive variables (11 of 16) but had a low effect (≤33%) on the other types of outcomes. In conclusion, face-to-face and e-interventions improved cognitive variables toward diet or PA but were less effective in changing actual behaviors. Environmental interventions favorably changed food sales. Face-to-face and e-interventions moderately affected WR outcomes. Future research should focus on long-term studies.http://dx.doi.org/10.1093/advances/nmz027inpressinpres

Structural Modification of Sol-gel Materials Through Retro Diels-Alder Reaction

Hydrolysis and condensation of organically bridged bis-triethoxysilanes, (EtO)âSi-R-Si(OEt)â, results in the formation of three dimensional organic/inorganic hybrid networks (Equation 1). Properties of these materials, including porosity, are dependent on the nature of the bridging group, R. Flexible groups (akylene-spacers longer than five carbons in length) polymerize under acidic conditions to give non-porous materials. Rigid groups (such as arylene-, alkynylene-, or alkenylene) form non-porous, microporous, and macroporous gels. In many cases the pore size distributions are quite narrow. One of the motivations for preparing hybrid organic-inorganic materials is to extend the range of properties available with sol-gel systems by incorporating organic groups into the inorganic network. For example, organically modified silica gels arc either prepared by co-polymerizing an organoalkoxysilane with a silica precursor or surface silylating the inorganic gel. This can serve to increase hydrophobicity or to introduce some reactive organic functionality. However, the type and orientation of these organic functionalities is difficult to control. Furthermore, many organoalkoxysilanes can act to inhibitor even prevent gelation, limiting the final density of organic functionalities. We have devised a new route for preparing highly functionalized pores in hybrid materials using bridging groups that are thermally converted into the desired functionalities after the gel has been obtained. In this paper, we present the preparation and characterization of bridged polysilsesquioxanes with Diels-Alder adducts as the bridging groups from the sol-gel polymerization of monomers 2 and 4. The bridging groups are constructed such that the retro Diela-Alder reaction releases the dienes and leaves the dienophiles as integral parts of the network polymers. In the rigid architecture of a xerogel, this loss of organic functionality should liberate sufficient space to modify the overall porosity. Furthermore, the new porosity will be functionalized with the dienophilic olefin bridging group. We also demonstrate that by changing the type of Diels-Alder adduct used as the bridging group, we can change the temperature at which the retro-Diels-Alder reaction will occur

Structural Modification of Sol-gel Materials Through Retro Diels-Alder Reaction

Hydrolysis and condensation of organically bridged bis-triethoxysilanes, (EtO){sub 3}Si-R-Si(OEt){sub 3}, results in the formation of three dimensional organic/inorganic hybrid networks (Equation 1). Properties of these materials, including porosity, are dependent on the nature of the bridging group, R. Flexible groups (akylene-spacers longer than five carbons in length) polymerize under acidic conditions to give non-porous materials. Rigid groups (such as arylene-, alkynylene-, or alkenylene) form non-porous, microporous, and macroporous gels. In many cases the pore size distributions are quite narrow. One of the motivations for preparing hybrid organic-inorganic materials is to extend the range of properties available with sol-gel systems by incorporating organic groups into the inorganic network. For example, organically modified silica gels arc either prepared by co-polymerizing an organoalkoxysilane with a silica precursor or surface silylating the inorganic gel. This can serve to increase hydrophobicity or to introduce some reactive organic functionality. However, the type and orientation of these organic functionalities is difficult to control. Furthermore, many organoalkoxysilanes can act to inhibitor even prevent gelation, limiting the final density of organic functionalities. We have devised a new route for preparing highly functionalized pores in hybrid materials using bridging groups that are thermally converted into the desired functionalities after the gel has been obtained. In this paper, we present the preparation and characterization of bridged polysilsesquioxanes with Diels-Alder adducts as the bridging groups from the sol-gel polymerization of monomers 2 and 4. The bridging groups are constructed such that the retro Diela-Alder reaction releases the dienes and leaves the dienophiles as integral parts of the network polymers. In the rigid architecture of a xerogel, this loss of organic functionality should liberate sufficient space to modify the overall porosity. Furthermore, the new porosity will be functionalized with the dienophilic olefin bridging group. We also demonstrate that by changing the type of Diels-Alder adduct used as the bridging group, we can change the temperature at which the retro-Diels-Alder reaction will occur

Polymerization of Bis(triethoxysilyl)ethenes. Impact of Substitution Geometry on the Formation of Ethenylene- and Vinylidene-Bridged Polysilsesquioxane

In this study, we utilized the substitution geometry of triethoxysilyl groups about an organic bridging group to control the outcome of the sol-gel polymerization process. The substitution geometry of two triethoxysilyl groups about a carbon-carbon double bond was determined to have a profound effect on sol-gel polymerizations of the E (1) and Z (2) ethenylene-bridged monomers and vinylidene-bridged monomer (3) and on the porosity in the resulting xerogels. 29Si NMR and chemical ionization mass spectrometry were used to elucidate the early sol-gel chemistry in the acid-catalyzed polymerizations of 1-3. Trans substitution about the ethenylene-bridging group in 1 led to acyclic and monocyclic dimers and trimers as condensation products under acidic conditions and only microporous gels under both acidic and basic conditions. In contrast, cyclization reactions dominated the sol-gel chemistry of 2 beginning with intramolecular cyclization to give the cyclic disilsesquioxane (4) and continued with the formation of cyclic oligomers, including a bicyclic dimer. The cyclization of 2 slowed the rate of gelation compared to 1 and afforded microporous xerogels under acidic conditions and mesoporous gels under basic conditions. The sol-gel chemistry of the vinylidene monomer (3) was strongly retarded by the formation of a cyclic dimer (5). Only mesoporous gels were formed under basic conditions after 9 months; no gels were obtained under acidic conditions