Headteachers' and chairs of governors' perspectives on adolescent obesity and its prevention in English secondary school settings.

BACKGROUND: Secondary schools are an important setting for preventing obesity in adolescence. Headteachers and chairs of governors are identified in national guidance as crucial stakeholders for school-based preventative action. Despite this, their views remain unexplored and unrepresented. METHODS: A sequential mixed method study was conducted. Semi-structured interviews were undertaken with a purposive sample of 22 secondary school headteachers and chairs of governors in England. Data were thematically analysed and informed the development of a descriptive cross-sectional survey, completed by 127 participants from the same population. RESULTS: Unhealthy dietary and sedentary behaviours were viewed as a more significant problem than adolescent obesity. Obesity was perceived as complex and multi-causal, and a range of stakeholders were deemed to have responsibility for its prevention, most notably parents. Support was identified for the role of secondary schools, although this was not an explicit priority and extensive internal and external barriers exist, which hinder preventative action. CONCLUSIONS: Whilst secondary school settings in England remain an important setting for the prevention of adolescent obesity, it is crucial for policy makers and public health professionals to recognize the factors affecting school leaders' ability and willingness to contribute to this agenda.

Measurement of the Vector and Tensor Asymmetries at Large Missing Momentum in Quasielastic (e[over →],e

We report the measurement of the beam-vector and tensor asymmetries A_{ed}^{V} and A_{d}^{T} in quasielastic (e[over →],e^{'}p) electrodisintegration of the deuteron at the MIT-Bates Linear Accelerator Center up to missing momentum of 500 MeV/c. Data were collected simultaneously over a momentum transfer range 0.1

Precise measurement of deuteron tensor analyzing powers with BLAST.

We report a precision measurement of the deuteron tensor analyzing powers T(20) and T(21) at the MIT-Bates Linear Accelerator Center. Data were collected simultaneously over a momentum transfer range Q=2.15-4.50 fm(-1) with the Bates Large Acceptance Spectrometer Toroid using a highly polarized deuterium internal gas target. The data are in excellent agreement with calculations in a framework of effective field theory. The deuteron charge monopole and quadrupole form factors G(C) and G(Q) were separated with improved precision, and the location of the first node of G(C) was confirmed at Q=4.19±0.05 fm(-1). The new data provide a strong constraint on theoretical models in a momentum transfer range covering the minimum of T(20) and the first node of G(C).

A FRET-based method for monitoring septin polymerization and binding of septin-associated proteins.

Much about septin function has been inferred from in vivo studies using mainly genetic methods, and much of what we know about septin organization has been obtained through examination of static structures in vitro primarily by electron microscopy. Deeper mechanistic insight requires real-time analysis of the dynamics of the assembly of septin-based structures and how other proteins associate with them. We describe here a Förster resonance energy transfer (FRET)-based approach for measuring in vitro the rate and extent of filament formation from septin complexes, binding of other proteins to septin structures, and the apparent affinities of these interactions. FRET is particularly well suited for interrogating protein-protein interactions, especially on a rapid timescale; the spectral change provides an unambiguous indication of whether two elements within the system under study are associating and serves as a molecular-level "ruler" because it is very sensitive to the separation between the donor and acceptor fluorophores over biologically relevant distances (≤10nm). The necessary procedures involve generation of appropriate cysteine-less and single cysteine-containing septin variants, expression and purification of the heterooctameric complexes containing them, efficient labeling of the purified complexes with desired fluorophores, fluorimetric measurement of FRET, and appropriate safeguards and controls in data acquisition and analysis. Our methods can be used to interrogate the effects of buffer conditions, small molecules, and septin-binding proteins on septin filament assembly or stability; determine the effect of alternative septin subunits, mutational alterations, or posttranslational modifications on assembly; and, delineate the location of septin-binding proteins.

Influence of pH on the conformation and stability of mismatch base-pairs in DNA.

A series of self-complementary dodecanucleotide duplexes containing two symmetrically disposed mismatches have been studied by pH-dependent, ultraviolet light melting techniques. The results indicate that A.C, and C.C mismatches are strongly stabilized by protonation and that the degree of stabilization of the A.C mismatch depends greatly on the flanking bases. In one case, a duplex containing two A.C mismatches is more stable than the native sequence below pH 5.5. The G.A mismatch displays conformational flexibility, with a protonated G(syn).A(anti) base-pair occurring in certain base stacking environments but not in others. The A.A and T.C mismatches are not stabilized at low pH. These solution studies correlate well with predictions based on X-ray crystallographic data.

Crystal structure and stability of a DNA duplex containing A(anti).G(syn) base-pairs.

The synthetic dodecanucleotide d(CGCAAATTGGCG) has been analysed by single-crystal X-ray diffraction techniques and the structure refined to R = 0.16 and 2.25 A resolution, with the location of 94 solvent molecules. The sequence crystallizes as a full turn of a B-DNA helix with ten Watson-Crick base-pairs and two adenine-guanine mispairs. The analysis clearly shows that the mismatches are of the form A(anti).G(syn). Thermal denaturation studies indicate that the stability of the duplex is strongly pH dependent, with a maximum at pH 5.0, suggesting that the base-pair is stabilized by protonation. Three different arrangements have been observed for base-pairs between guanine and adenine and it is likely that A.G mismatch conformation is strongly influenced by dipole-dipole interactions with adjacent base-pairs.

The cyclic relationship of estrogen sulfurylation to the nuclear receptor level in human endometrial curettings.

Human endometrial curettings were selected principally from patients undergoing tubal ligations for elective sterilization. Specimens were analyzed for the metabolism of 17beta-[6,7-3H]estradiol and Na2 35SO4; assayed for the nuclear receptor content with 17beta-[6,7-3H]estradiol; and examined for the cytosol receptor content with 17beta-[2,4,6,7-3H]estradiol. The results of these experiments demonstrated that a) estrogen sulfotransferase activity is greatly stimulated during the secretory phase; b) although estrogen dehydrogenase is active throughout the menstrual cycle, the formation of estrone is elevated in concert with sulfurylation; and c) this increased metabolism of 17beta-estradiol is accompanied by a decreased nuclear uptake of the estrogen receptor complex. The importance of this endometrial estrogen metabolism in the maintenance of a secretory tissue is discussed.

H-Y antigen in a 46,XX female with dysgenetic ovaries.

Hypogonadism secondary to ovarian dysgenesis or resistant ovary syndrome was diagnosed in a 19-yr-old obese woman with primary amenorrhea, a 46,XX karyotype, and an H-Y+ cellular phenotype. Small ovoid gonads (1.5 X 0.6 cm) were found found bilaterally; these were encased in a dense venous network. The stroma was ovarian, and primordial follicles and some primary follicles were present, but there were no follicles at or beyond the antrum stage. There was no evidence of testicular tissue and no evidence of malignancy. Analysis of serological data indicated the possibility of residual H-Y antigen in the blood cells of the mother.

Quantitative and qualitative differences in the metabolism of 14C-1,3-butadiene in rats and mice: relevance to cancer susceptibility.

1,3-Butadiene (butadiene) is a potent carcinogen in mice, but not in rats. Metabolic studies may provide an explanation of these species differences and their relevance to humans. Male Sprague-Dawley rats and B6C3F1 mice were exposed for 6 h to 200 ppm [2,3-14C]-butadiene (specific radioactivity [sa] 20 mCi/mmol) in a Cannon nose-only system. Radioactivity in urine, feces, exhaled volatiles and 14C-CO2 were measured during and up to 42 h after exposure. The total uptake of butadiene by rats and mice under these experimental conditions was 0.19 and 0.38 mmol (equivalent to 3.8 and 7.5 mCi) per kg body weight, respectively. In the rat, 40% of the recovered radioactivity was exhaled as 14C-CO2, 70% of which was trapped during the 6-h exposure period. In contrast, only 6% was exhaled as 14C-CO2 by mice, 3% during the 6-h exposure and 97% in the 42 h following cessation of exposure. The formation of 14C-CO2 from [2,3-14C]-labeled butadiene indicated a ready biodegradability of butadiene. Radioactivity excreted in urine accounted for 42% of the recovered radioactivity from rats and 71% from mice. Small amounts of radioactivity were recovered in feces, exhaled volatiles and carcasses. Although there was a large measure of commonality, the exposure to butadiene also led to the formation of different metabolites in rats and mice. These metabolites were not found after administration of [4-14C]-1,2-epoxy-3-butene to animals by i.p. injection. The results show that the species differences in the metabolism of butadiene are not simply confined to the quantitative formation of epoxides, but also reflect a species-dependent selection of metabolic pathways. No metabolites other than those formed via an epoxide intermediate were identified in the urine of rats or mice after exposure to 14C-butadiene. These findings may have relevance for the prediction of butadiene toxicity and provide a basis for a revision of the existing physiologically based pharmacokinetic models.

Comparison of immunoaffinity chromatography enrichment and nuclease P1 procedures for 32P-postlabelling analysis of PAH-DNA adducts.

32P-postlabelling analysis for detecting DNA adducts formed by polycyclic aromatic compounds is one of the most widely used techniques for assessing genotoxicity associated with these compounds. In cases where the formation of adducts is extremely low, a crucial step in the analysis is an enrichment procedure for adducts prior to the radiolabelling step. The nuclease P1 enhancement procedure is the most established and frequently used of these methods. An immunoaffinity procedure developed for class specific recognition for polycyclic aromatic hydrocarbon (PAH)-DNA adducts has therefore been compared with the nuclease P1 method for a range of DNA adducts formed by PAHs. The evaluation was carried out with skin DNA from mice treated topically with benzo[a]pyrene, 7,12-dimethylbenz[a]anthracene, 5-methylchrysene or chrysene. The immobilised antibody had the highest affinity for adducts structurally similar to the BPDE-I-deoxyguanosine adduct ([+/-]-N2-(7r,8t,9r-trihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene-1 0t-yl)-2'-deoxyguanosine) against which the antibody had been raised. Of the PAH-modified DNAs evaluated, the maximum adduct recovery was obtained for DNA containing the BPDE I-deoxyguanosine adduct. With DMBA-modified DNA, the profiles of adducts recovered from the column were similar when the column material was treated either with a digest of DMBA-modified DNA or with 32P-labelled DMBA adducts. I-compounds (endogenous adducts in tissue DNA of unexposed animals), which had similar chromatographic properties to PAH-DNA adducts, were not enriched by the immunoaffinity procedure. Compared to the simple nuclease P1 enhancement procedure, the immunoaffinity methods were lengthier and more labour intensive. Advantages of the immunoaffinity procedure include: specificity, allowing the selective detection of a certain class of adducts: efficient adduct enrichment, providing a viable alternative to other enrichment procedures; adequate sensitivity for model studies and the potential to purify adducts for further characterisation. However, as a general screen for detecting the formation of DNA adducts, the nuclease P1 procedure was viewed as the initial method of choice since it was capable of detecting a wider range of PAH-DNA adducts.

The risk of foot ulceration in people with diabetes screened in community settings: findings from a cohort study.

BACKGROUND: Annual foot checks are recommended in patients with diabetes mellitus (DM) to identify those at risk of foot ulceration. Systematic reviews have found few studies evaluating the predictive value of tests in community-based diabetic populations. AIM: To quantify the predictive value of clinical risk factors in relation to foot ulceration in a community population. METHODS: A cohort of 1192 people with diabetes receiving care in community settings was recruited and a screening procedure, covering symptoms, signs and diagnostic tests was conducted at baseline. At an average 1-year follow-up patients who developed a foot ulcer were identified by an independent blind assessor. Multivariable analysis was performed to identify clinical predictors of foot ulceration. FINDINGS: The incidence of foot ulceration was 1.93% [95% confidence interval (CI) 1.27-2.89). Three time-independent clinical predictors with five factors were selected: previous amputation [odds ratio (OR) 14.7, 95% CI 3.1-69.5), use of insulin before 3 months with inability to distinguish between cool and cold temperatures (OR 2.97, 95% CI 1.9-4.5) and failure to obtain at least one blood pressure reading for the calculation of ankle-brachial index with the failure to feel touch with a 10-g monofilament (OR 1.7, 95% CI 1.3-2.2). INTERPRETATION: Recommendations for annual diabetic foot check in low-risk, community-based patients should be reviewed as absolute events of ulceration are low. The accuracy of foot risk assessment tools to predict ulceration requires evaluation in randomized controlled trials with concurrent economic evaluations.

Charge form factor of the neutron at low momentum transfer from the 2H-->(e-->,e'n)1H reaction.

We report new measurements of the neutron charge form factor at low momentum transfer using quasielastic electrodisintegration of the deuteron. Longitudinally polarized electrons at an energy of 850 MeV were scattered from an isotopically pure, highly polarized deuterium gas target. The scattered electrons and coincident neutrons were measured by the Bates Large Acceptance Spectrometer Toroid (BLAST) detector. The neutron form factor ratio GEn/GMn was extracted from the beam-target vector asymmetry AedV at four-momentum transfers Q2=0.14, 0.20, 0.29, and 0.42 (GeV/c)2.

-Measurement of the proton's electric to magnetic form factor ratio from 1H(over -->)(e(over -->),e'p).

We report the first precision measurement of the proton electric to magnetic form factor ratio from spin-dependent elastic scattering of longitudinally polarized electrons from a polarized hydrogen internal gas target. The measurement was performed at the MIT-Bates South Hall Ring over a range of four-momentum transfer squared Q2 from 0.15 to 0.65 (GeV/c)(2). Significantly improved results on the proton electric and magnetic form factors are obtained in combination with existing cross-section data on elastic electron-proton scattering in the same Q2 region.