Food insecurity and food preparation equipment in US households: exploratory results from a cross-sectional questionnaire.

BACKGROUND: Food insecurity (FI) impacted 15.7% (5.9 million) of US households with children in 2017. These households often experience issues within one or more of the food security pillars: access, availability, utilisation or stability. An underexplored area within the pillar of utilisation that may impact FI risk is the availability of kitchen equipment in households. This exploratory project aimed to quantify household food preparation equipment ownership and use by household FI status. METHODS: An online platform (Qualtrics, Provo, UT, USA) was used to administer a questionnaire to a sample of 135 parents of children aged 11-14 years. The instrument queried sociodemographic characteristics, food preparation items owned and frequency of use of 44 items within a 6-month interval. Household FI was measured using the 18-item US Department of Agriculture, Household Food Security Survey Module with a 12-month reference period. RESULTS: Households experiencing FI (n = 39; 28.9%) owned an average of five fewer items than their food secure counterparts (n = 96, 71.1%, P < 0.001), reporting lower item ownership within each equipment category subgroup (i.e. large appliances, small appliances, food preparation utensils and cooking utensils; all P < 0.01). There were no differences between FI and food secure households in frequency of use (all P > 0.01). CONCLUSIONS: Compared to food secure households, the number of food preparation items owned was lower, although frequency of use was the same, in US households that were FI. Future projects should investigate how food equipment ownership impacts cooking behaviours, and whether households experiencing FI display behaviours to compensate for a differing set of equipment.

Successful melanoma triage by a virtual lesion clinic (teledermatoscopy).

BACKGROUND: A Virtual Lesion Clinic (VLC) using teledermatoscopy was established to improve efficiency of the melanoma referral pathway. OBJECTIVES: To assess diagnostic accuracy and to compare wait-times and costs of VLC and conventional clinics. METHODS: Patients with suspected melanoma referred from primary care into a publicly funded health system attended local skin imaging centres, rather than hospital outpatient clinics. A teledermatologist assessed each lesion choosing specialist assessment/excision, General Practitioner (GP) follow-up, to re-image in 3 months, or self-monitoring/no concern. RESULTS: 613 skin lesions in 310 patients were evaluated over 12 months. Median time between receipt of referral and attendance at the VLC was 9 days compared to 26.5 days for standard outpatient assessment. Sixty-six percent (404/613) of lesions were considered benign, and 12% (73/613) were suspicious for melanoma. Of 129 lesions excised, 98 were skin cancers including 48 histologically confirmed melanomas with one spitzoid tumour of unknown malignant potential (STUMP), i.e. one melanoma per 1.59 suspected lesions biopsied and one melanoma in every 12.8 referred to the service. There were 49 non-melanoma skin cancers (NMSC). Teledermatoscopic diagnosis of melanomas was found to have a positive predictive value (PPV) of 63%. Compared to the conventional clinic, cost reductions from running the VLC for 1 year were in excess of NZ$364,000 (or NZ$1174/patient seen). CONCLUSIONS: The VLC offered an efficient, accurate and cost effective way of processing suspected melanoma referrals to the public health system.

Morphometry of the hippocampal microvasculature in post-stroke and age-related dementias.

BACKGROUND: Optimal vascular function is vital for prevention of dementia. We hypothesized that elderly post-stroke survivors who preserve cognitive function show unperturbed cerebral microvasculature compared with those who develop dementia. METHODS: Using stereological spherical probe software, we compared the length density (Lv, cumulative vessel length per unit tissue volume) of hippocampal microvessels in post mortem brain tissue from post-stroke survivors, Alzheimer's disease (AD), vascular dementia (VaD) and normal ageing control subjects. We also assessed microvessel diameters in the same subjects. Microvessels were identified by markers of endothelial cells (glucose transporter 1; GLUT1), basement membrane (collagen IV; COL4) and smooth muscle cell α-actin (SMA). RESULTS: We found increased Lv of both GLUT1 and COL4 immunostained microvessels (P < 0.05) in the hippocampal CA1 region of post-stroke demented (PSD) and AD cases compared with post-stroke nondemented (PSND), control and VaD subjects. However, no changes were apparent in the CA2 region. We also noted significant increase in Lv in the entorhinal cortex of AD compared with PSND and PSD subjects. The mean diameter of microvessels was decreased in PSD, compared with PSND, as well as in AD and VaD compared with controls. Cumulative frequency analysis showed PSND subjects to have significantly greater proportion of microvessels with diameters, ranging from 7 to 12 µm. CONCLUSIONS: An increase in microvascular Lv in AD and PSD suggests either an increase in angiogenesis or the formation of newer microvessel loops in response to cerebral hypoperfusion. The decreased vessel diameters found in AD and VaD suggests increased vasoconstriction in dementia.

Excision pathways for keratinocyte cancers diagnosed by teledermatology: a retrospective review.

Introduction The New Zealand population has one of the highest incidences of skin cancer in the world. Hospital waiting lists for surgical excision of keratinocytic skin cancers (basal cell carcinoma and squamous cell carcinoma) are lengthy, and increasingly, excisions are undertaken in primary care. Teledermatology, in response to general practitioners' electronic referrals (e-referrals), can improve clinical communication between general practitioners and dermatologists. Aim The aim of this study was to evaluate an excision pathway for keratinocytic cancers diagnosed by teledermatology. Methods A retrospective observational descriptive review of a 3-month cohort of primary care e-referrals was undertaken. Results Three hundred and fifty eight suspected keratinocytic cancers (KCs) were diagnosed by teledermatology; histology reports confirmed KC in 201 of 267 excisions (75%). The majority (77.2%) were excised by general practitioners an average of 25 days after the dermatologist's recommendation. The rest were excised by plastic surgeons in private (3.4%) or at a public hospital (19.5%) after an average of 40 or 134 days, respectively. Discussion E-referral pathways are now widely implemented. However, the ideal workflow for skin cancer management is unknown. We have demonstrated in New Zealand that surgery can be undertaken in primary care within a month of a teledermatology diagnosis and excision recommendation. Conclusion This study reports prompt excision of KCs by general practitioners after an e-referral and a teledermatology response.

Effect of narrowband ultraviolet B phototherapy on melanocytic naevi.

BACKGROUND: Melanocytic naevi have been observed to undergo morphological changes following exposure to narrowband ultraviolet (NB-UV)B radiation. OBJECTIVES: To analyse changes in naevi exposed to NB-UVB in a large cohort of patients. METHODS: Subjects referred for phototherapy had macroscopic and dermoscopic images taken of prominent melanocytic naevi at the following time points: immediately prior to NB-UVB treatment, after 10 exposures, after 30 exposures or at the end of treatment if earlier, and 3 months after discontinuing treatment. Four dermatologists, by consensus, examined each naevus for specific clinical and dermoscopic features at each time point. The size (area) of each naevus was determined by plenimetry. RESULTS: Complete sets of images were taken for 36 out of 51 patients. The most common global dermoscopic patterns in the 440 naevi examined were reticular (50%) and globular (32%). Following NB-UVB exposure, blurring or merging of lines was observed in 45% of reticular naevi. An increase in colour intensity and in the number of dots or globules was observed in 63% of globular naevi, and 167 naevi (40%) underwent a change in size. Of these, 91/167 (54%) decreased in size, with a median area reduction of 8% (0·9-42%); while 76/167 (46%) increased in size, with a median area increase of 9% (1-76%). CONCLUSIONS: Around half of naevi exposed to a course of NB-UVB treatment undergo size or morphological changes. Naevi that enlarged tended to revert to pretreatment size 3 months after discontinuation of phototherapy.

Combined spectroscopic and computational study for optimising catalyst design in hydrocarbon transformations.

Molecular interactions of hydrocarbons within the confined pores of heterogeneous catalysts can influence reaction pathways, which play a crucial role in determining the overall efficacy of catalytic transformations. We probe the interactions of n-butane with a solid-acid zeolite, mordenite, combining inelastic neutron scattering with DFT calculations. This reveals that the solid-acid sites within mordenite induce a conformer change, which could be key in designing optimised catalysts, for hydrocarbon transformations.

Successful triage of patients referred to a skin lesion clinic using teledermoscopy (IMAGE IT trial).

BACKGROUND: Teledermatology is a rapidly growing field with studies showing high diagnostic accuracy when compared with face-to-face diagnosis. Teledermoscopy involves the use of epiluminescence microscopy to increase diagnostic accuracy. The utility of teledermoscopy as a triage tool has not been established. OBJECTIVES: To assess teledermoscopy as a triage tool for a hospital skin lesion clinic. METHODS: Patients referred to a dermatology skin lesion clinic were recruited. Digital and dermoscopic photographs were taken of skin lesions of concern and the patients were then seen independently face-to-face by two out of three dermatologists. The digital images were evaluated 4 weeks later, as a teledermoscopy consultation, by two of these dermatologists. The diagnosis and management from both types of consultation were compared. RESULTS: Two hundred patients with a total of 491 lesions were seen. There was excellent agreement between teledermoscopy and face-to-face diagnosis with only 12.3% of lesions having disparate diagnoses of clinical significance. Twelve of 491 (2.4%) lesions appeared to have been under-reported by teledermoscopy when compared with face-to-face diagnosis. However, when histopathology became available, only one malignant lesion had been missed (a basal cell carcinoma diagnosed as solar keratosis) by teledermoscopy. Teledermoscopy approximated 100% sensitivity and 90% specificity for detecting melanoma and nonmelanoma skin cancers. Importantly, 74% of all lesions were determined to be manageable by the general practitioner without needing to be seen face-to-face by a dermatologist. CONCLUSIONS: This use of teledermoscopy as a triage tool offers the potential to shorten waiting lists and thus improve healthcare access and delivery.

Interobserver variability of teledermoscopy: an international study.

BACKGROUND: Teledermoscopy is a rapidly developing field of dermatology with studies demonstrating excellent agreement with face-to-face diagnosis. However, we are unaware of studies evaluating interobserver variability in diagnosis between dermatologists from different continents. This evaluation is important to determine the robustness of teledermoscopy and allow comparisons to be made between different studies. OBJECTIVES: To assess the interobserver diagnostic variability between five independent experienced dermatologists (A-E) in New Zealand, Australia and the U.S.A. METHODS: Images from 979 lesions from 206 patients were distributed to five dermatologists. The lesions were viewed and diagnoses recorded using MoleMap Diagnose (MoleMap, Auckland, New Zealand) software. The diagnoses were analysed for interobserver variability. RESULTS: There was excellent agreement between four of five dermatologists (A-D) for lesions that were agreed upon as melanoma (κ = 0·81-0·97) and benign naevus (κ = 0·77-0·82).The fifth dermatologist (E) made a more frequent diagnosis of atypical naevus and melanoma than the others. For nonmelanocytic lesions, there was moderate to very good agreement for seborrhoeic keratosis (κ = 0·64-0·80) and basal cell carcinoma (κ = 0·55-0·67), but poor agreement for invasive squamous cell carcinoma (SCC) (κ = 0·05-0·15). Agreement for actinic keratosis (κ = 0·32-0·67) and SCC in situ (κ = 0·15-0·32) was only moderate. When atypical and benign naevi were grouped together and actinic keratosis and SCC in situ grouped together, there was better agreement among all dermatologists. There was good ability to distinguish malignant from benign lesions (κ = 0·57-0·93). CONCLUSIONS: There was good agreement among dermatologists A-D but dermatologist E varied from the group with more frequent diagnosis of melanoma and atypical naevus. This difference could be due to different definition of terms with lack of consensus guidelines in definition of atypical naevus, lack of familiarity with the specific patient population and/or diagnostic drift.

Estradiol enables cortisol to act directly upon the pituitary to suppress pituitary responsiveness to GnRH in sheep.

We have shown that cortisol infusion reduced the luteinizing hormone (LH) response to fixed hourly GnRH injections in ovariectomized ewes treated with estradiol during the non-breeding season (pituitary-clamp model). In contrast, cortisol did not affect the response to 2 hourly invariant GnRH injections in hypothalamo-pituitary disconnected ovariectomized ewes during the breeding season. To understand the differing results in these animal models and to determine if cortisol can act directly at the pituitary to suppress responsiveness to GnRH, we investigated the importance of the frequency of GnRH stimulus, the presence of estradiol and stage of the circannual breeding season. In experiment 1, during the non-breeding season, ovariectomized ewes were treated with estradiol, and pulsatile LH secretion was restored with i.v. GnRH injections either hourly or 2 hourly in the presence or absence of exogenous cortisol. Experiments 2 and 3 were conducted in hypothalamo-pituitary disconnected ovariectomized ewes in which GnRH was injected i.v. every 2 h. Experiment 2 was conducted during the non-breeding season and saline or cortisol was infused for 30 h in a cross-over design. Experiment 3 was conducted during the non-breeding and breeding seasons and saline or cortisol was infused for 30 h in the absence and presence of estradiol using a cross-over design. Samples were taken from all animals to measure plasma LH. LH pulse amplitude was reduced by cortisol in the pituitary clamp model with no difference between the hourly and 2-hourly GnRH pulse mode. In the absence of estradiol, there was no effect of cortisol on LH pulse amplitude in GnRH-replaced ovariectomized hypothalamo-pituitary disconnected ewes in either season. The LH pulse amplitude was reduced in both seasons in experiment 3 when cortisol was infused during estradiol treatment. We conclude that the ability of cortisol to reduce LH secretion does not depend upon the frequency of GnRH stimulus and that estradiol enables cortisol to act directly on the pituitary of ovariectomized hypothalamo-pituitary disconnected ewes to suppress the responsiveness to GnRH; this effect occurs in the breeding and non-breeding seasons.

Medullary autonomic pathology in carotid sinus hypersensitivity.

AIMS: Carotid sinus hypersensitivity (CSH) is an ageing-related autonomic disorder, rarely occurring before the age of 50 years but increasing in incidence thereafter. Clinical symptoms of CSH include falls and dizziness, thought to be precipitated by dysfunctional baroreflex responses. CSH is highly prevalent in Alzheimer's disease (AD), Parkinson's disease (PD) and dementia with Lewy bodies (DLB); diseases that are associated with variable degeneration of medullary autonomic nuclei which regulate baroreflex responses. Currently, there are no descriptions of the integrity of medullary autonomic nuclei in CSH. We hypothesized medullary autonomic degeneration is found in elderly patients with CSH. METHODS: Using in vitro digital imaging, we quantified the burden of tau, amyloid beta and alpha-synuclein in autonomic nuclei of 12 patients prospectively assessed with CSH (age 83 years) compared with 14 (80 years) control subjects. RESULTS: We found increased tau (P < 0.000) accumulation in baroreflex associated nuclei, but not the hypoglossal or raphe in the CSH patients. Medullary tau accumulation was not related to the development of AD in the CSH patients. Tau was colocalized to catecholaminergic neurones and occurred in the absence of neuronal loss. We found no difference in alpha-synuclein, amyloid beta or microglial numbers between the CSH cases and controls. CONCLUSIONS: We suggest that hyperphosphorylated tau accumulation particularly in tyrosine hydroxylase containing neurones may impair central regulation of baroreflex responses in patients with CSH. Future clinic-pathological investigations should reveal whether medullary degeneration is the cause of CSH symptoms.

Does the UK government's teenage pregnancy strategy deal with the correct risk factors? Findings from a secondary analysis of data from a randomised trial of sex education and their implications for policy.

BACKGROUND: Much of the UK government's 1999 report on teenage pregnancy was by necessity based on rather old or non-longitudinal research. AIM: To examine the associations between risk factors identified in the report and pregnancy at or before age 16 years among young women and partners of young men using the more recent data. RESULTS: Socioeconomic disadvantage, being born to a teenage mother, expectation of being a teenage parent, low educational expectations and various other behaviours are potential risk factors for teenage pregnancy, as suggested by unadjusted analyses. Those who cited school as providing information on sex had a reduced risk of pregnancy at or before age 16 years, as did girls reporting easy communication with parent or guardian at baseline. Various measures of low sexual health knowledge were not associated, in either adjusted or unadjusted analyses, with increased risk of pregnancy at or before age 16 years among boys or girls. CONCLUSIONS: A focus on many of the risk factors identified in the 1999 report is supported herein. It is suggested that knowledge may not be an important determinant, but that relationships with parents and school, as well as expectations for the future, may have important influences on teenage pregnancy. The analysis also provides new insights into risk factors for pregnancies among the partners of young men.

Effects of NOS inhibition on the cardiopulmonary system and brain microvascular markers after intermittent hypoxia in rats.

We previously demonstrated that rats subjected to intermittent hypoxia (IH) by exposure to 10% O(2) for 4 h daily for 56 days in a normobaric chamber, developed pulmonary hypertension, right ventricular hypertrophy and wall-thickening in pulmonary arterioles, compared with normoxic (N) controls. These changes were greater in rats subjected to continuous hypoxia (CH breathing 10% O(2) for 56 days). Cerebral angiogenesis was demonstrated by immunostaining with glucose transporter 1 (GLUT1) antibody, in viable vessels, in CH and to a lesser degree in IH. In this study, adult Wistar rats were subjected to the same hypoxic regimes and given the nitric oxide synthase (NOS) inhibitor N(6)-nitro-L-arginine methyl ester (L-NAME) in drinking water (NLN, IHLN and CHLN regimes) to induce hypertension. There was significant systemic hypertension in NLN and IHLN rats, compared with N and IH, but surprisingly not in CHLN compared with CH. Hematocrit rose in all hypoxic groups (up to 79% in CHLN). There was no significant pulmonary hypertension in IHLN versus NLN rats, although there was asymmetric wall thickening in pulmonary arterioles. Cerebral GLUT1 immunoreactivity increased with L-NAME, with or without hypoxia, especially in CHLN rats, but conspicuously there was no evidence of angiogenesis in brains of IHLN compared with NLN rats. NOS blockade may attenuate the cerebral and pulmonary vascular changes of IH while augmenting cerebral angiogenesis in continuous hypoxia. However, whether cerebral effects are due to systemic hypertension or changes in cerebral nitric oxide production needs to be evaluated.

Influence of family type and parenting behaviours on teenage sexual behaviour and conceptions.

BACKGROUND: Longitudinal data were used to explore relations between teenage pregnancy, sexual behaviour, and family type. The study examined whether students from lone parent and/or teenage mother initiated families more commonly report sex, lack of contraception at first sex, and/or conceptions by age 15/16, and whether such associations can be explained by low parental strictness, difficult parent-child communication, and/or low parental input into sex education. Up to date longitudinal UK research on family influences on conceptions is lacking, as is longitudinal research on family influences on sexual behaviour. No previous studies have comprehensively examined effects of parenting behaviours. Unlike previous research, this study tested theories suggesting that parenting deficits among lone parent and teenage initiated families increase risk of teenage pregnancy among their children. METHODS: Secondary analysis of data from a trial of sex education. RESULTS: Girls and boys from lone parent families or having mothers who were teenagers when they were born were more likely to report sex but not lack of contraception at first sex by age 15/16. Girls and boys with mothers having them as teenagers, and boys but not girls from lone parent families, were more likely to report being involved in conceptions by age 15/16. Only the association between teenage mother family and girls' conceptions was reduced by adjusting for a parenting behaviour measure. CONCLUSIONS: Students from lone parent families or having mothers who were teenagers when they were born are more likely to report early sexual debut and conceptions by age 15/16, but this is not generally explained by parenting style.

Human theta class glutathione transferase: the crystal structure reveals a sulfate-binding pocket within a buried active site.

BACKGROUND: Glutathione S-transferases (GSTs) comprise a multifunctional group of enzymes that play a critical role in the cellular detoxification process. These enzymes reduce the reactivity of toxic compounds by catalyzing their conjugation with glutathione. As a result of their role in detoxification, GSTs have been implicated in the development of cellular resistance to antibiotics, herbicides and clinical drugs and their study is therefore of much interest. In mammals, the cytosolic GSTs can be divided into five distinct classes termed alpha, mu, pi, sigma and theta. The human theta class GST, hGST T2-2, possesses several distinctive features compared to GSTs of other classes, including a long C-terminal extension and a specific sulfatase activity. It was hoped that the determination of the structure of hGST T2-2 may help us to understand more about this unusual class of enzymes. RESULTS: Here we present the crystal structures of hGST T2-2 in the apo form and in complex with the substrates glutathione and 1-menaphthyl sulfate. The enzyme adopts the canonical GST fold with a 40-residue C-terminal extension comprising two helices connected by a long loop. The extension completely buries the substrate-binding pocket and occludes most of the glutathione-binding site. The enzyme has a purpose-built novel sulfate-binding site. The crystals were shown to be catalytically active: soaks with 1-menaphthyl sulfate result in the production of the glutathione conjugate and cleavage of the sulfate group. CONCLUSIONS: hGST T2-2 shares less than 15% sequence identity with other GST classes, yet adopts a similar three-dimensional fold. The C-terminal extension that blocks the active site is not disordered in either the apo or complexed forms of the enzyme, but nevertheless catalysis occurs in the crystalline state. A narrow tunnel leading from the active site to the surface may provide a pathway for the entry of substrates and the release of products. The results suggest a molecular basis for the unique sulfatase activity of this GST.

Effects of diethyldithiocarbamate and nine other nucleophiles on the intersubunit protein cross-linking and inactivation of purified human alpha 2-macroglobulin by cis-diamminedichloroplatinum(II).

The cross-linking and inactivation of the plasma protein alpha 2-macroglobulin by cis-diamminedichloroplatinum(II) (cisplatin; Gonias, S. L., and Pizzo, S. V. J. Biol. Chem., 256: 12478-12484, 1981) was used to study platinum(II)-protein binding in the presence of compounds of therapeutic or biochemical significance. Diethyldithiocarbamate, potassium cyanide (KCN), sodium thiocyanate, L-methionine, N-acetyl-L-cysteine, 2-aminoethanethiol, L-cysteine, L-lysine, L-histidine, and L-arginine demonstrated variable capacity to inhibit reaction of cisplatin with protein and to reverse bidentate platinum(II)-protein binding in the in vitro model system. alpha 2-Macroglobulin lost 90% of its activity and was completely cross-linked, as determined with polyacrylamide gel electrophoresis, after reaction with cisplatin (0.6 to 1.0 mM). When diethyldithiocarbamate (4 to 15 mM) was incubated with alpha 2-macroglobulin and cisplatin, protein inactivation and cross-linking were totally prevented. In experiments with alpha 2-macroglobulin-platinum(II) complex, purified by gel filtration chromatography, 1.0 mM diethyldithiocarbamate completely reactivated the protein and eliminated nearly all of the intersubunit cross-links. Only KCN was comparably effective as an inhibitor of the reaction of cisplatin with alpha 2-macroglobulin; however, KCN was significantly less reactive with preformed platinum(II)-protein bonds than was diethyldithiocarbamate. N-Acetyl-L-cysteine, 2-aminoethanethiol, and L-cysteine were moderately reactive with free cisplatin. This group of compounds also demonstrated a low level of reactivity with the purified alpha 2-macroglobulin-platinum(II) complex. L-Methionine inhibited reaction of cisplatin with the protein, but was ineffective at reversing the reaction in the concentration range studied. The remaining compounds had little or no effect on the reaction of cisplatin with alpha 2-macroglobulin. The ability of diethyldithiocarbamate to displace nucleophilic protein groups from highly stable bonds with platinum(II) may be critical in its function as a rescue agent, limiting cisplatin toxicity towards nontumor cells.

Long-term survival of segmental pancreas isografts in NOD/Lt mice treated with anti-CD4 and anti-CD8 monoclonal antibodies.

Spontaneously diabetic nonobese diabetic (NOD/Lt) mice were treated with anti-T-cell monoclonal antibodies (mAbs) at the time of grafting with vascularized segmental pancreas isografts. Recipients were either untreated or given anti-CD4 and/or anti-CD8 mAbs (0.5 mg/20-g mouse on each of 4 consecutive days), which reduced target cell levels to <5% of normal. Graft function was monitored by measuring blood glucose (BG) levels. Transplants were removed for histological examination when BG returned to >20 mmol/l for two consecutive readings. Isografts from 3- to 4-week-old prediabetic mice placed in untreated diabetic NOD mice ceased functioning in 9-13 days with a mean survival time (MST) +/- SD of 10 +/- 2. Treatment with anti-CD4 prolonged survival significantly (MST = 61 +/- 35 days, P < 0.05 compared with untreated control mice). Anti-CD8 treatment was less effective, but it still significantly improved graft survival (MST = 24 +/- 9 days, P < 0.05 compared with untreated control mice). Anti-CD8 plus anti-CD4 treatment was highly effective in inhibiting autoimmune destruction of the grafts (MST = 97 +/- 8 days). This clearly demonstrates that transient inactivation of most T-cells with anti-CD4 plus anti-CD8 mAbs effectively controls autoimmune disease in the isograft, despite recovery of CD4 and CD8 T-cells to normal levels. Although insulitis developed in the long-term grafts, insulitis scores did not increase between 33 and 100 days, and none of the mice progressed to IDDM in 100 days. Histology showed a predominantly peri-islet T-cell and macrophage infiltrate with ductal expression of the cytokines interleukin (IL)-4, IL-2, and interferon-gamma. There was little infiltrate or expression of cytokines within the islets. Thus, mAb treatment at the time of grafting allowed isograft survival and prevented progression from insulitis to beta-cell destruction.

Pupil-led sex education in England (RIPPLE study): cluster-randomised intervention trial.

BACKGROUND: Improvement of sex education in schools is a key part of the UK government's strategy to reduce teenage pregnancy in England. We examined the effectiveness of one form of peer-led sex education in a school-based randomised trial of over 8000 pupils. METHODS: 29 schools were randomised to either peer-led sex education (intervention) or to continue their usual teacher-led sex education (control). In intervention schools, peer educators aged 16-17 years delivered three sessions of sex education to 13-14 year-old pupils from the same schools. Primary outcome was unprotected (without condom) first heterosexual intercourse by age 16 years. Analysis was by intention to treat. FINDINGS: By age 16 years, significantly fewer girls reported intercourse in the peer-led arm than in the control arm, but proportions were similar for boys. The proportions of pupils reporting unprotected first sex did not differ for girls (8.4% intervention vs 8.3% control) or for boys (6.2% vs 4.7%). Stratified estimates of the difference between arms were -0.4% (95% CI -3.7% to 2.8%, p=0.79) for girls and -1.4% (-4.4% to 1.6%, p=0.36) for boys. At follow-up (mean age 16.0 years [SD 0.32]), girls in the intervention arm reported fewer unintended pregnancies, although the difference was borderline (2.3% vs 3.3%, p=0.07). Girls and boys were more satisfied with peer-led than teacher-led sex education, but 57% of girls and 32% of boys wanted sex education in single-sex groups. INTERPRETATION: Peer-led sex education was effective in some ways, but broader strategies are needed to improve young people's sexual health. The role of single-sex sessions should be investigated further.

The ligandin (non-substrate) binding site of human Pi class glutathione transferase is located in the electrophile binding site (H-site).

Glutathione S -transferases (GSTs) play a pivotal role in the detoxification of foreign chemicals and toxic metabolites. They were originally termed ligandins because of their ability to bind large molecules (molecular masses >400 Da), possibly for storage and transport roles. The location of the ligandin site in mammalian GSTs is still uncertain despite numerous studies in recent years. Here we show by X-ray crystallography that the ligandin binding site in human pi class GST P1-1 occupies part of one of the substrate binding sites. This work has been extended to the determination of a number of enzyme complex crystal structures which show that very large ligands are readily accommodated into this substrate binding site and in all, but one case, causes no significant movement of protein side-chains. Some of these molecules make use of a hitherto undescribed binding site located in a surface pocket of the enzyme. This site is conserved in most, but not all, classes of GSTs suggesting it may play an important functional role.

Structures of thermolabile mutants of human glutathione transferase P1-1.

An N-capping box motif (Ser/Thr-Xaa-Xaa-Asp) is strictly conserved at the beginning of helix alpha6 in the core of virtually all glutathione transferases (GST) and GST-related proteins. It has been demonstrated that this local motif is important in determining the alpha-helical propensity of the isolated alpha6-peptide and plays a crucial role in the folding and stability of GSTs. Its removal by site-directed mutagenesis generated temperature-sensitive folding mutants unable to refold at physiological temperature (37 degrees C). In the present work, variants of human GSTP1-1 (S150A and D153A), in which the capping residues have been substituted by alanine, have been generated and purified for structural analysis. Thus, for the first time, temperature-sensitive folding mutants of an enzyme, expressed at a permissive temperature, have been crystallized and their three-dimensional structures determined by X-ray crystallography. The crystal structures of human pi class GST temperature-sensitive mutants provide a basis for understanding the structural origin of the dramatic effects observed on the overall stability of the enzyme at higher temperatures upon single substitution of a capping residue.