query: 0-dimensional biomaterials show inductive properties.

positive: New opportunities: the use of nanotechnologies to manipulate and track stem cells. Nanotechnologies are emerging platforms that could be useful in measuring, understanding, and manipulating stem cells. Examples include magnetic nanoparticles and quantum dots for stem cell labeling and in vivo tracking; nanoparticles, carbon nanotubes, and polyplexes for the intracellular delivery of genes/oligonucleotides and protein/peptides; and engineered nanometer-scale scaffolds for stem cell differentiation and transplantation. This review examines the use of nanotechnologies for stem cell tracking, differentiation, and transplantation. We further discuss their utility and the potential concerns regarding their cytotoxicity.

negative: The first gene of the Bacillus subtilis clpC operon, ctsR, encodes a negative regulator of its own operon and other class III heat shock genes. The Bacillus subtilis clpC operon is regulated by two stress induction pathways relying on either sigmaB or a class III stress induction mechanism acting at a sigmaA-like promoter. When the clpC operon was placed under the control of the isopropyl-beta-D-thiogalactopyranoside (IPTG)-inducible Pspac promoter, dramatic repression of the natural clpC promoters fused to a lacZ reporter gene was noticed after IPTG induction. This result strongly indicated negative regulation of the clpC operon by one of its gene products. Indeed, the negative regulator could be identified which is encoded by the first gene of the clpC operon, ctsR, containing a predicted helix-turn-helix DNA-binding motif. Deletion of ctsR abolished the negative regulation and resulted in high expression of both the clpC operon and the clpP gene under nonstressed conditions. Nevertheless, a further increase in clpC and clpP mRNA levels was observed after heat shock, even in the absence of sigmaB, suggesting a second induction mechanism at the vegetative promoter. Two-dimensional gel analysis and mRNA studies showed that the expression of other class III stress genes was at least partially influenced by the ctsR deletion. Studies with different clpC promoter fragments either fused to the reporter gene bgaB or used in gel mobility shift experiments with the purified CtsR protein revealed a possible target region where the repressor seemed to bind in vivo and in vitro. Our data demonstrate that the CtsR protein acts as a global repressor of the clpC operon, as well as other class III heat shock genes, by preventing unstressed transcription from either the sigmaB- or sigmaA-dependent promoter and might be inactivated or dissociate under inducing stress conditions.

negative: Circulating plasma microRNAs as a screening method for detection of colorectal adenomas. BACKGROUND MicroRNAs (miRNAs) are small non-coding RNA molecules. Reduced or increased levels of specific miRNAs are observed in colon and other cancers, supporting their role in carcinogenesis. Detection of colorectal polyps is the cornerstone of the Bowel Cancer Screening Programme in the UK. However, uptake of screening nationally remains under 60%. We aimed to see whether circulating plasma miRNAs can be used to screen for patients with colorectal polyps, adenomas, or both. METHODS Blood samples were taken from patients from the Bowel Cancer Screening Programme (asymptomatic but faecal occult blood testing [FOBt] positive). Plasma RNA was extracted, target miRNAs (19a, 98, 146b, 186, 191, 222*, 331-5p, 452, 625, 664, 1247) were identified on pooled case miRNA assay cards, and miRNA fraction was quantified by quantitative RT-PCR assay. Results were compared with endoscopy reports and with histology of any polyps identified and removed. Analysis was done with Excel (2011) and SPSS (version 20) software. FINDINGS 210 patients were included (117 with polyps, 12 with cancer, 81 healthy controls [FOBt positive]). The miRNA panel showed significant differences in expression (on t testing) for patients compared with controls for those with polyps, cancer, or both (miR-19a, p=0·0184; miR-98, p=0·0206; miR-146b, p=0·0029; miR-186, p=0·0006; miR-62,5 p=0·0008), polyps (miR-19a, p=0·0233; miR-98, p=0·0224; miR-146b, p=0·003; miR-186, p=0·0004; miR-625, p=0·001), adenomas (miR-19a, p=0·0339; miR-98, p=0·0266; miR-146b, p=0·0045; miR-186, p=0·0008; miR-625, p=0·0049), multiple adenomas (both sides of colon; miR-146b, p=0·0194; miR-186, p=0·0226; miR-625, p=0·0013), and right-sided adenomas (miR-98, p=0·031; miR-146b, p=0·0076; miR-186, p=0·0041; miR-331-5p, p=0·0142; miR-625, p=0·0049). Receiver operating characteristic analysis showed sensitivity of 60% or more, and specificity of 86% or more for men with polyps, men with adenomas, all patients with haemorrhoids or diverticulosis and polyps, and all patients with haemorrhoids or diverticulosis and adenomas. INTERPRETATION The target miRNAs that we identified showed significant differences in expression levels for patients with polyps and patients with adenomas from controls. Use of this panel has potential as a screening test. FUNDING Bowel Disease Research Foundation.

negative: How long will long-term potentiation last? The paramount feature of long-term potentiation (LTP) as a memory mechanism is its characteristic persistence over time. Although the basic phenomenology of LTP persistence was established 30 years ago, new insights have emerged recently about the extent of LTP persistence and its regulation by activity and experience. Thus, it is now evident that LTP, at least in the dentate gyrus, can either be decremental, lasting from hours to weeks, or stable, lasting months or longer. Although mechanisms engaged during the induction of LTP regulate its subsequent persistence, the maintenance of LTP is also governed by activity patterns post-induction, whether induced experimentally or generated by experience. These new findings establish dentate gyrus LTP as a useful model system for studying the mechanisms governing the induction, maintenance and interference with long-term memory, including very long-term memory lasting months or longer. The challenge is to study LTP persistence in other brain areas, and to relate, if possible, the properties and regulation of LTP maintenance to these same properties of the information that is actually stored in those regions.

negative: Modification in the chemical bath deposition apparatus, growth and characterization of CdS semiconducting thin films for photovoltaic applications Abstract In this paper, growth and characterization of CdS thin films by Chemical Bath Deposition (CBD) technique using the reaction between CdCl 2 , (NH 2 ) 2 CS and NH 3 in an aqueous solution has been reported. The parameters actively involved in the process of deposition have been identified. A commonly available CBD system has been sucessfully modified to obtain the precious control over the pH of the solution at 90°C during the deposition and studies have been made to understand the fundamental parameters like concentrations of the solution, pH and temperature of the solution involved in the chemical bath deposition of CdS. It is confirmed that the pH of the solution plays a vital role in the quality of the CBD–CdS films. Structural, optical and electrical properties have been analysed for the as-deposited and annealed films. XRD studies on the CBD–CdS films reveal that the change in Cadmium ion concentration in the bath results in the change in crystallization from cubic phase with (1 1 1) predominant orientation to a hexagonal phase with (0 0 2) predominant orientation. The structural changes due to varying cadmium ion concentration in the bath affects the optical and electrical properties. Optimum electrical resistivity, band gap and refractive index value are observed for the annealed films deposited from 0.8 M cadmium ion concentration. The films are suitable for solar cell fabrication. Further on, annealing the samples at 350°C in H 2 for 30 min resulted in an increased diffraction intensity as well as shifts in the peak towards lower scattering angles due to enlarged CdS unit cell. This in turn brought about an increase in the lattice parameters and narrowing in the band-gap values. The results are compared with the analysis of previous work.

negative: Large deformation of red blood cell ghosts in a simple shear flow. Red blood cells are known to change shape in response to local flow conditions. Deformability affects red blood cell physiological function and the hydrodynamic properties of blood. The immersed boundary method is used to simulate three-dimensional membrane-fluid flow interactions for cells with the same internal and external fluid viscosities. The method has been validated for small deformations of an initially spherical capsule in simple shear flow for both neo-Hookean and the Evans-Skalak membrane models. Initially oblate spheroidal capsules are simulated and it is shown that the red blood cell membrane exhibits asymptotic behavior as the ratio of the dilation modulus to the extensional modulus is increased and a good approximation of local area conservation is obtained. Tank treading behavior is observed and its period calculated.

negative: 0021-972X/06/$15.00/0 The Journal of Clinical Endocrinology & Metabolism 91(3):760–771 Printed in U.S.A. Copyright © 2006 by The Endocrine Society doi: 10.1210/jc.2005-1923 REVIEW: Aromatase Inhibitors for Ovulation Induction CONTEXT For the last 40 yr, the first line of treatment for anovulation in infertile women has been clomiphene citrate (CC). CC is a safe, effective oral agent but is known to have relatively common antiestrogenic endometrial and cervical mucous side effects that could prevent pregnancy in the face of successful ovulation. In addition, there is a significant risk of multiple pregnancy with CC, compared with natural cycles. Because of these problems, we proposed the concept of aromatase inhibition as a new method of ovulation induction that could avoid many of the adverse effects of CC. The objective of this review was to describe the different physiological mechanisms of action for CC and aromatase inhibitors (AIs) and compare studies of efficacy for both agents for ovulation induction. EVIDENCE ACQUISITION We conducted a systematic review of all the published studies, both controlled and noncontrolled, comparing CC and AI treatment, either alone or in combination with gonadotropins, for ovulation induction or augmentation, identified through the Entrez-PubMed search engine. EVIDENCE SYNTHESIS Because of the recent acceptance of the concept of using AIs for ovulation induction, few controlled studies were identified, and the rest of the studies were pilot or preliminary comparisons. Based on these studies, it appears that AIs are as effective as CC in inducing ovulation, are devoid of any antiestrogenic side effects, result in lower serum estrogen concentrations, and are associated with good pregnancy rates with a lower incidence of multiple pregnancy than CC. When combined with gonadotropins for assisted reproductive technologies, AIs reduce the dose of FSH required for optimal follicle recruitment and improve the response to FSH in poor responders. CONCLUSIONS Preliminary evidence suggests that AIs may replace CC in the future because of similar efficacy with a reduced side effect profile. Although worldwide experience with AIs for ovulation induction is increasing, at present, definitive studies in the form of randomized controlled trials comparing CC with AIs are lacking.

negative: Human embryonic stem cells with biological and epigenetic characteristics similar to those of mouse ESCs. Human and mouse embryonic stem cells (ESCs) are derived from blastocyst-stage embryos but have very different biological properties, and molecular analyses suggest that the pluripotent state of human ESCs isolated so far corresponds to that of mouse-derived epiblast stem cells (EpiSCs). Here we rewire the identity of conventional human ESCs into a more immature state that extensively shares defining features with pluripotent mouse ESCs. This was achieved by ectopic induction of Oct4, Klf4, and Klf2 factors combined with LIF and inhibitors of glycogen synthase kinase 3beta (GSK3beta) and mitogen-activated protein kinase (ERK1/2) pathway. Forskolin, a protein kinase A pathway agonist which can induce Klf4 and Klf2 expression, transiently substitutes for the requirement for ectopic transgene expression. In contrast to conventional human ESCs, these epigenetically converted cells have growth properties, an X-chromosome activation state (XaXa), a gene expression profile, and a signaling pathway dependence that are highly similar to those of mouse ESCs. Finally, the same growth conditions allow the derivation of human induced pluripotent stem (iPS) cells with similar properties as mouse iPS cells. The generation of validated "naïve" human ESCs will allow the molecular dissection of a previously undefined pluripotent state in humans and may open up new opportunities for patient-specific, disease-relevant research.

negative: Long-term effect of aspirin on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial BACKGROUND Observational studies report reduced colorectal cancer in regular aspirin consumers. Randomised controlled trials have shown reduced risk of adenomas but none have employed prevention of colorectal cancer as a primary endpoint. The CAPP2 trial aimed to investigate the antineoplastic effects of aspirin and a resistant starch in carriers of Lynch syndrome, the major form of hereditary colorectal cancer; we now report long-term follow-up of participants randomly assigned to aspirin or placebo. METHODS In the CAPP2 randomised trial, carriers of Lynch syndrome were randomly assigned in a two-by-two factorial design to 600 mg aspirin or aspirin placebo or 30 g resistant starch or starch placebo, for up to 4 years. Randomisation was in blocks of 16 with provision for optional single-agent randomisation and extended postintervention double-blind follow-up; participants and investigators were masked to treatment allocation. The primary endpoint was development of colorectal cancer. Analysis was by intention to treat and per protocol. This trial is registered, ISRCTN59521990. RESULTS 861 participants were randomly assigned to aspirin or aspirin placebo. At a mean follow-up of 55·7 months, 48 participants had developed 53 primary colorectal cancers (18 of 427 randomly assigned to aspirin, 30 of 434 to aspirin placebo). Intention-to-treat analysis of time to first colorectal cancer showed a hazard ratio (HR) of 0·63 (95% CI 0·35-1·13, p=0·12). Poisson regression taking account of multiple primary events gave an incidence rate ratio (IRR) of 0·56 (95% CI 0·32-0·99, p=0·05). For participants completing 2 years of intervention (258 aspirin, 250 aspirin placebo), per-protocol analysis yielded an HR of 0·41 (0·19-0·86, p=0·02) and an IRR of 0·37 (0·18-0·78, p=0·008). No data for adverse events were available postintervention; during the intervention, adverse events did not differ between aspirin and placebo groups. INTERPRETATION 600 mg aspirin per day for a mean of 25 months substantially reduced cancer incidence after 55·7 months in carriers of hereditary colorectal cancer. Further studies are needed to establish the optimum dose and duration of aspirin treatment. FUNDING European Union; Cancer Research UK; Bayer Corporation; National Starch and Chemical Co; UK Medical Research Council; Newcastle Hospitals trustees; Cancer Council of Victoria Australia; THRIPP South Africa; The Finnish Cancer Foundation; SIAK Switzerland; Bayer Pharma.

negative: A central role for HER3 in HER2-amplified breast cancer: implications for targeted therapy. Epidermal growth factor receptor (EGFR) and HER3 each form heterodimers with HER2 and have independently been implicated as key coreceptors that drive HER2-amplified breast cancer. Some studies suggest a dominant role for EGFR, a notion of renewed interest given the development of dual HER2/EGFR small-molecule inhibitors. Other studies point to HER3 as the primary coreceptor. To clarify the relative contributions of EGFR and HER3 to HER2 signaling, we studied receptor knockdown via small interfering RNA technology across a panel of six HER2-overexpressing cell lines. Interestingly, HER3 was as critical as HER2 for maintaining cell proliferation in most cell lines, whereas EGFR was dispensable. Induction of HER3 knockdown in the HER2-overexpressing BT474M1 cell line was found to inhibit growth in three-dimensional culture and induce rapid tumor regression of in vivo xenografts. Furthermore, preferential phosphorylation of HER3, but not EGFR, was observed in HER2-amplified breast cancer tissues. Given these data suggesting HER3 as an important therapeutic target, we examined the activity of pertuzumab, a HER2 antibody that inhibits HER3 signaling by blocking ligand-induced HER2/HER3 heterodimerization. Pertuzumab inhibited ligand-dependent morphogenesis in three-dimensional culture and induced tumor regression in the heregulin-dependent MDA-MB-175 xenograft model. Importantly, these activities of pertuzumab were distinct from those of trastuzumab, a monoclonal antibody currently used for treatment of HER2-amplified breast cancer patients. Our data suggest that inhibition of HER3 may be more clinically relevant than inhibition of EGFR in HER2-amplified breast cancer and also suggest that adding pertuzumab to trastuzumab may augment therapeutic benefit by blocking HER2/HER3 signaling.

negative: Data analysis methods for detection of differential protein expression in two-dimensional gel electrophoresis. The recent development of microarray technology has led statisticians and bioinformaticians to develop new statistical methodologies for comparing different biological samples. The objective is to identify a small number of differentially expressed genes from among thousands. In quantitative proteomics, analysis of protein expression using two-dimensional gel electrophoresis shows some similarities with transcriptomic studies. Thus, the goal of this study was to evaluate different data analysis methodologies widely used in array analysis using different proteomic data sets of hundreds of proteins. Even with few replications, the significance analysis of microarrays method appeared to be more powerful than the Student's t test in truly declaring differentially expressed proteins. This procedure will avoid wasting time due to false positives and losing information with false negatives.

negative: Electrical, optical, and structural properties of indium-tin-oxide thin films for organic light-emitting devices High-quality indium–tin–oxide (ITO) thin films (200–850 nm) have been grown by pulsed laser deposition (PLD) on glass substrates without a postdeposition annealing treatment. The structural, electrical, and optical properties of these films have been investigated as a function of target composition, substrate deposition temperature, background gas pressure, and film thickness. Films were deposited from various target compositions ranging from 0 to 15 wt % of SnO2 content. The optimum target composition for high conductivity was 5 wt % SnO2+95 wt % In2O3. Films were deposited at substrate temperatures ranging from room temperature to 300 °C in O2 partial pressures ranging from 1 to 100 mTorr. Films were deposited using a KrF excimer laser (248 nm, 30 ns full width at half maximum) at a fluence of 2 J/cm2. For a 150-nm-thick ITO film grown at room temperature in an oxygen pressure of 10 mTorr, the resistivity was 4×10−4 Ω cm and the average transmission in the visible range (400–700 nm) was 85%. For a 170-n...

negative: 2D and 3D Stem Cell Models of Primate Cortical Development Identify Species-Specific Differences in Progenitor Behavior Contributing to Brain Size. Variation in cerebral cortex size and complexity is thought to contribute to differences in cognitive ability between humans and other animals. Here we compare cortical progenitor cell output in humans and three nonhuman primates using directed differentiation of pluripotent stem cells (PSCs) in adherent two-dimensional (2D) and organoid three-dimensional (3D) culture systems. Clonal lineage analysis showed that primate cortical progenitors proliferate for a protracted period of time, during which they generate early-born neurons, in contrast to rodents, where this expansion phase largely ceases before neurogenesis begins. The extent of this additional cortical progenitor expansion differs among primates, leading to differences in the number of neurons generated by each progenitor cell. We found that this mechanism for controlling cortical size is regulated cell autonomously in culture, suggesting that primate cerebral cortex size is regulated at least in part at the level of individual cortical progenitor cell clonal output.

negative: Comparisons between different polychemotherapy regimens for early breast cancer: meta-analyses of long-term outcome among 100,000 women in 123 randomised trials. BACKGROUND Moderate differences in efficacy between adjuvant chemotherapy regimens for breast cancer are plausible, and could affect treatment choices. We sought any such differences. METHODS We undertook individual-patient-data meta-analyses of the randomised trials comparing: any taxane-plus-anthracycline-based regimen versus the same, or more, non-taxane chemotherapy (n=44,000); one anthracycline-based regimen versus another (n=7000) or versus cyclophosphamide, methotrexate, and fluorouracil (CMF; n=18,000); and polychemotherapy versus no chemotherapy (n=32,000). The scheduled dosages of these three drugs and of the anthracyclines doxorubicin (A) and epirubicin (E) were used to define standard CMF, standard 4AC, and CAF and CEF. Log-rank breast cancer mortality rate ratios (RRs) are reported. FINDINGS In trials adding four separate cycles of a taxane to a fixed anthracycline-based control regimen, extending treatment duration, breast cancer mortality was reduced (RR 0·86, SE 0·04, two-sided significance [2p]=0·0005). In trials with four such extra cycles of a taxane counterbalanced in controls by extra cycles of other cytotoxic drugs, roughly doubling non-taxane dosage, there was no significant difference (RR 0·94, SE 0·06, 2p=0·33). Trials with CMF-treated controls showed that standard 4AC and standard CMF were equivalent (RR 0·98, SE 0·05, 2p=0·67), but that anthracycline-based regimens with substantially higher cumulative dosage than standard 4AC (eg, CAF or CEF) were superior to standard CMF (RR 0·78, SE 0·06, 2p=0·0004). Trials versus no chemotherapy also suggested greater mortality reductions with CAF (RR 0·64, SE 0·09, 2p<0·0001) than with standard 4AC (RR 0·78, SE 0·09, 2p=0·01) or standard CMF (RR 0·76, SE 0·05, 2p<0·0001). In all meta-analyses involving taxane-based or anthracycline-based regimens, proportional risk reductions were little affected by age, nodal status, tumour diameter or differentiation (moderate or poor; few were well differentiated), oestrogen receptor status, or tamoxifen use. Hence, largely independently of age (up to at least 70 years) or the tumour characteristics currently available to us for the patients selected to be in these trials, some taxane-plus-anthracycline-based or higher-cumulative-dosage anthracycline-based regimens (not requiring stem cells) reduced breast cancer mortality by, on average, about one-third. 10-year overall mortality differences paralleled breast cancer mortality differences, despite taxane, anthracycline, and other toxicities. INTERPRETATION 10-year gains from a one-third breast cancer mortality reduction depend on absolute risks without chemotherapy (which, for oestrogen-receptor-positive disease, are the risks remaining with appropriate endocrine therapy). Low absolute risk implies low absolute benefit, but information was lacking about tumour gene expression markers or quantitative immunohistochemistry that might help to predict risk, chemosensitivity, or both. FUNDING Cancer Research UK; British Heart Foundation; UK Medical Research Council.

negative: Cerebral organoids model human brain development and microcephaly The complexity of the human brain has made it difficult to study many brain disorders in model organisms, highlighting the need for an in vitro model of human brain development. Here we have developed a human pluripotent stem cell-derived three-dimensional organoid culture system, termed cerebral organoids, that develop various discrete, although interdependent, brain regions. These include a cerebral cortex containing progenitor populations that organize and produce mature cortical neuron subtypes. Furthermore, cerebral organoids are shown to recapitulate features of human cortical development, namely characteristic progenitor zone organization with abundant outer radial glial stem cells. Finally, we use RNA interference and patient-specific induced pluripotent stem cells to model microcephaly, a disorder that has been difficult to recapitulate in mice. We demonstrate premature neuronal differentiation in patient organoids, a defect that could help to explain the disease phenotype. Together, these data show that three-dimensional organoids can recapitulate development and disease even in this most complex human tissue.

negative: The carboxyl terminus of human cytomegalovirus-encoded 7 transmembrane receptor US28 camouflages agonism by mediating constitutive endocytosis. US28 is one of four 7 transmembrane (7TM) chemokine receptors encoded by human cytomegalovirus and has been shown to both signal and endocytose in a ligand-independent, constitutively active manner. Here we show that the constitutive activity and constitutive endocytosis properties of US28 are separable entities in this viral chemokine receptor. We generated chimeric and mutant US28 proteins that were altered in either their constitutive endocytic (US28 Delta 300, US28 Delta 317, US28-NK1-ctail, and US28-ORF74-ctail) or signaling properties (US28R129A). By using this series of mutants, we show that the cytoplasmic tail domain of US28 per se regulates receptor endocytosis, independent of the signaling ability of the core domain of US28. The constitutive endocytic property of the US28 c-tail was transposable to other 7TM receptors, the herpes virus 8-encoded ORF74 and the tachykinin NK1 receptor (ORF74-US28-ctail and NK1-US28-ctail). Deletion of the US28 C terminus resulted in reduced constitutive endocytosis and consequently enhanced signaling capacity of all receptors tested as assessed by inositol phosphate turnover, NF-kappa B, and cAMP-responsive element-binding protein transcription assays. We further show that the constitutive endocytic property of US28 affects the action of its chemokine ligand fractalkine/CX3CL1 and show that in the absence of the US28 C terminus, fractalkine/CX3CL1 acts as an agonist on US28. This demonstrates for the first time that the endocytic properties of a 7TM receptor can camouflage the agonist properties of a ligand.

negative: Effect modification by population dietary folate on the association between MTHFR genotype, homocysteine, and stroke risk: a meta-analysis of genetic studies and randomised trials BACKGROUND The MTHFR 677C→T polymorphism has been associated with raised homocysteine concentration and increased risk of stroke. A previous overview showed that the effects were greatest in regions with low dietary folate consumption, but differentiation between the effect of folate and small-study bias was difficult. A meta-analysis of randomised trials of homocysteine-lowering interventions showed no reduction in coronary heart disease events or stroke, but the trials were generally set in populations with high folate consumption. We aimed to reduce the effect of small-study bias and investigate whether folate status modifies the association between MTHFR 677C→T and stroke in a genetic analysis and meta-analysis of randomised controlled trials. METHODS We established a collaboration of genetic studies consisting of 237 datasets including 59,995 individuals with data for homocysteine and 20,885 stroke events. We compared the genetic findings with a meta-analysis of 13 randomised trials of homocysteine-lowering treatments and stroke risk (45,549 individuals, 2314 stroke events, 269 transient ischaemic attacks). FINDINGS The effect of the MTHFR 677C→T variant on homocysteine concentration was larger in low folate regions (Asia; difference between individuals with TT versus CC genotype, 3·12 μmol/L, 95% CI 2·23 to 4·01) than in areas with folate fortification (America, Australia, and New Zealand, high; 0·13 μmol/L, -0·85 to 1·11). The odds ratio (OR) for stroke was also higher in Asia (1·68, 95% CI 1·44 to 1·97) than in America, Australia, and New Zealand, high (1·03, 0·84 to 1·25). Most randomised trials took place in regions with high or increasing population folate concentrations. The summary relative risk (RR) of stroke in trials of homocysteine-lowering interventions (0·94, 95% CI 0·85 to 1·04) was similar to that predicted for the same extent of homocysteine reduction in large genetic studies in populations with similar folate status (predicted RR 1·00, 95% CI 0·90 to 1·11). Although the predicted effect of homocysteine reduction from large genetic studies in low folate regions (Asia) was larger (RR 0·78, 95% CI 0·68 to 0·90), no trial has evaluated the effect of lowering of homocysteine on stroke risk exclusively in a low folate region. INTERPRETATION In regions with increasing levels or established policies of population folate supplementation, evidence from genetic studies and randomised trials is concordant in suggesting an absence of benefit from lowering of homocysteine for prevention of stroke. Further large-scale genetic studies of the association between MTHFR 677C→T and stroke in low folate settings are needed to distinguish effect modification by folate from small-study bias. If future randomised trials of homocysteine-lowering interventions for stroke prevention are undertaken, they should take place in regions with low folate consumption. FUNDING Full funding sources listed at end of paper (see Acknowledgments).

negative: Three-dimensional structure of the AAH26994.1 protein from Mus musculus, a putative eukaryotic Urm1. We have used NMR spectroscopy to determine the solution structure of protein AAH26994.1 from Mus musculus and propose that it represents the first three-dimensional structure of a ubiquitin-related modifier 1 (Urm1) protein. Amino acid sequence comparisons indicate that AAH26994.1 belongs to the Urm1 family of ubiquitin-like modifier proteins. The best characterized member of this family has been shown to be involved in nutrient sensing, invasive growth, and budding in yeast. Proteins in this family have only a weak sequence similarity to ubiquitin, and the structure of AAH26994.1 showed a much closer resemblance to MoaD subunits of molybdopterin synthases (known structures are of three bacterial MoaD proteins with 14%-26% sequence identity to AAH26994.1). The structures of AAH26994.1 and the MoaD proteins each contain the signature ubiquitin secondary structure fold, but all differ from ubiquitin largely in regions outside of this fold. This structural similarity bolsters the hypothesis that ubiquitin and ubiquitin-related proteins evolved from a protein-based sulfide donor system of the molybdopterin synthase type.

negative: Role of ocular pigment epithelial cells in immune privilege The ocular microenvironment is both immunosuppressive and anti-inflammatory in nature. Pigment epithelial (PE) cells isolated from the eye possess the ability to suppress the T cell receptor-dependent activation of T cells and the induction of regulatory T cells in vitro. This property is dependent on the cells’ capacity to produce cell-surface and soluble inhibitory molecules, for example CD86 (B7-2), transforming growth factor (TGF)-β, thrombospondin-1, programmed cell death 1 ligand 1 (PD-L1/B7-H1), and cytotoxic T lymphocyte-associated antigen 2α. Cultured ocular PE cells from the iris, ciliary body, and retina can individually suppress T-cell activation via mechanisms that partially overlap. Moreover, PE-derived regulatory T cells acquire functions that play a role in establishing immune regulation in the eye. Multiple strategies are employed within the eye to control immune-mediated inflammation. This phenomenon is known as immune privilege and is instrumental in helping to prevent extensive damage to bystander cells that would otherwise lead to blindness. This review focuses on the immunosuppressive property and role of ocular PE cells in immune privileged sites.

negative: Latent membrane protein 1 of Epstein–Barr virus coordinately regulates proliferation with control of apoptosis Latent membrane protein 1 (LMP1), an oncoprotein encoded by Epstein–Barr virus (EBV), is an integral membrane protein, which acts like a constitutively active receptor. LMP1 is critical for some facet of EBV's induction and maintenance of proliferation of infected B cells. It, in part, mimics signaling by the CD40 receptor and has been implicated in regulating proliferation, survival, or both properties of EBV-infected cells. We established a conditional LMP1 allele in the context of the intact EBV genome to define the immediate-early cellular target genes regulated by LMP1 in order to assess its contributions to infected human B cells. The functional analysis of this conditional system indicated that LMP1 specifically induces mitogenic B-cell activation through c-myc and Jun/AP1 family members and confirms its direct role in upregulating expression of multiple genes with opposing activities involved in cell survival. LMP1's signals were found to be essential for the G1/S transition in human B cells; cells lacking LMP1's signals are cell cycle arrested and survive quiescently. LMP1's activities are therefore not required to maintain survival in nonproliferating cells. LMP1 does induce both pro- and antiapoptotic genes whose balance seems to permit survival during LMP1's induction and maintenance of proliferation.

negative: Human papillomavirus testing for the detection of high-grade cervical intraepithelial neoplasia and cancer: final results of the POBASCAM randomised controlled trial. BACKGROUND Human papillomavirus (HPV) testing is more sensitive for the detection of high-grade cervical lesions than is cytology, but detection of HPV by DNA screening in two screening rounds 5 years apart has not been assessed. The aim of this study was to assess whether HPV DNA testing in the first screen decreases detection of cervical intraepithelial neoplasia (CIN) grade 3 or worse, CIN grade 2 or worse, and cervical cancer in the second screening. METHODS In this randomised trial, women aged 29-56 years participating in the cervical screening programme in the Netherlands were randomly assigned to receive HPV DNA (GP5+/6+-PCR method) and cytology co-testing or cytology testing alone, from January, 1999, to September, 2002. Randomisation (in a 1:1 ratio) was done with computer-generated random numbers after the cervical specimen had been taken. At the second screening 5 years later, HPV DNA and cytology co-testing was done in both groups; researchers were masked to the patient's assignment. The primary endpoint was the number of CIN grade 3 or worse detected. Analysis was done by intention to screen. The trial is now finished and is registered, number ISRCTN20781131. FINDINGS 22,420 women were randomly assigned to the intervention group and 22 518 to the control group; 19 999 in the intervention group and 20,106 in the control group were eligible for analysis at the first screen. At the second screen, 19 579 women in the intervention group and 19,731 in the control group were eligible, of whom 16,750 and 16,743, respectively, attended the second screen. In the second round, CIN grade 3 or worse was less common in the intervention group than in the control group (88 of 19 579 in the intervention group vs 122 of 19,731 in the control group; relative risk 0·73, 95% CI 0·55-0·96; p=0·023). Cervical cancer was also less common in the intervention group than in the control group (four of 19 579 in the intervention group vs 14 of 19,731; 0·29, 0·10-0·87; p=0·031). In the baseline round, detection of CIN grade 3 or worse did not differ significantly between groups (171 of 19 999 vs 150 of 20,106; 1·15, 0·92-1·43; p=0·239) but was significantly more common in women with normal cytology (34 of 19,286 vs 12 of 19,373; 2·85, 1·47-5·49; p=0·001). Furthermore, significantly more cases of CIN grade 2 or worse were detected in the intervention group than in the control group (267 of 19 999 vs 215 of 20,106; 1·25, 1·05-1·50; p=0·015). In the second screen, fewer HPV16-positive CIN grade 3 or worse were detected in the intervention group than in the control group (17 of 9481 vs 35 of 9354; 0·48, 0·27-0·85; p=0·012); detection of non-HPV16-positive CIN grade 3 or worse did not differ between groups (25 of 9481 vs 25 of 9354; 0·99, 0·57-1·72; p=1·00). The cumulative detection of CIN grade 3 or worse and CIN grade 2 or worse did not differ significantly between study arms, neither for the whole study group (CIN grade 3 or worse: 259 of 19 999 vs 272 of 20,106; 0·96, 0·81-1·14, p=0·631; CIN grade 2 or worse: 427 of 19 999 vs 399 of 20,106; 1·08, 0·94-1·24; p=0·292), nor for subgroups of women invited for the first time (CIN grade 3 or worse in women aged 29-33 years: 102 of 3139 vs 105 of 3128; 0·97, 0·74-1·27; CIN grade 2 or worse in women aged 29-33 years: 153 of 3139 vs 151 of 3128; 1·01, 0·81-1·26; CIN grade 3 or worse in women aged 34-56 years: 157 of 16,860 vs 167 of 16 978; 0·95, 0·76-1·18; CIN grade 2 or worse in women aged 34-56 years: 274 of 16,860 vs 248 of 16 978; 1·11, 0·94-1·32). INTERPRETATION Implementation of HPV DNA testing in cervical screening leads to earlier detection of clinically relevant CIN grade 2 or worse, which when adequately treated, improves protection against CIN grade 3 or worse and cervical cancer. Early detection of high-grade cervical legions caused by HPV16 was a major component of this benefit. Our results lend support to the use of HPV DNA testing for all women aged 29 years and older. FUNDING Zorg Onderzoek Nederland (Netherlands Organisation for Health Research and Development).

negative: Chemotherapy options in elderly and frail patients with metastatic colorectal cancer (MRC FOCUS2): an open-label, randomised factorial trial BACKGROUND Elderly and frail patients with cancer, although often treated with chemotherapy, are under-represented in clinical trials. We designed FOCUS2 to investigate reduced-dose chemotherapy options and to seek objective predictors of outcome in frail patients with advanced colorectal cancer. METHODS We undertook an open, 2 × 2 factorial trial in 61 UK centres for patients with previously untreated advanced colorectal cancer who were considered unfit for full-dose chemotherapy. After comprehensive health assessment (CHA), patients were randomly assigned by minimisation to: 48-h intravenous fluorouracil with levofolinate (group A); oxaliplatin and fluorouracil (group B); capecitabine (group C); or oxaliplatin and capecitabine (group D). Treatment allocation was not masked. Starting doses were 80% of standard doses, with discretionary escalation to full dose after 6 weeks. The two primary outcome measures were: addition of oxaliplatin ([A vs B] + [C vs D]), assessed with progression-free survival (PFS); and substitution of fluorouracil with capecitabine ([A vs C] + [B vs D]), assessed by change from baseline to 12 weeks in global quality of life (QoL). Analysis was by intention to treat. Baseline clinical and CHA data were modelled against outcomes with a novel composite measure, overall treatment utility (OTU). This study is registered, number ISRCTN21221452. FINDINGS 459 patients were randomly assigned (115 to each of groups A-C, 114 to group D). Factorial comparison of addition of oxaliplatin versus no addition suggested some improvement in PFS, but the finding was not significant (median 5·8 months [IQR 3·3-7·5] vs 4·5 months [2·8-6·4]; hazard ratio 0·84, 95% CI 0·69-1·01, p=0·07). Replacement of fluorouracil with capecitabine did not improve global QoL: 69 of 124 (56%) patients receiving fluorouracil reported improvement in global QoL compared with 69 of 123 (56%) receiving capecitabine. The risk of having any grade 3 or worse toxic effect was not significantly increased with oxaliplatin (83/219 [38%] vs 70/221 [32%]; p=0·17), but was higher with capecitabine than with fluorouracil (88/222 [40%] vs 65/218 [30%]; p=0·03). In multivariable analysis, fewer baseline symptoms (odds ratio 1·32, 95% CI 1·14-1·52), less widespread disease (1·51, 1·05-2·19), and use of oxaliplatin (0·57, 0·39-0·82) were predictive of better OTU. INTERPRETATION FOCUS2 shows that with an appropriate design, including reduced starting doses of chemotherapy, frail and elderly patients can participate in a randomised controlled trial. On balance, a combination including oxaliplatin was preferable to single-agent fluoropyrimidines, although the primary endpoint of PFS was not met. Capecitabine did not improve QoL compared with fluorouracil. Comprehensive baseline assessment holds promise as an objective predictor of treatment benefit. FUNDING Cancer Research UK and the Medical Research Council.

negative: Promiscuous gene expression in medullary thymic epithelial cells mirrors the peripheral self Expression of peripheral antigens in the thymus has been implicated in T cell tolerance and autoimmunity. Here we identified medullary thymic epithelial cells as being a unique cell type that expresses a diverse range of tissue-specific antigens. We found that this promiscuous gene expression was a cell-autonomous property of medullary epithelial cells and was maintained during the entire period of thymic T cell output. It may facilitate tolerance induction to self-antigens that would otherwise be temporally or spatially secluded from the immune system. However, the array of promiscuously expressed self-antigens appeared random rather than selected and was not confined to secluded self-antigens.

negative: Synaptic islands defined by the territory of a single astrocyte. In the mammalian brain, astrocytes modulate neuronal function, in part, by synchronizing neuronal firing and coordinating synaptic networks. Little, however, is known about how this is accomplished from a structural standpoint. To investigate the structural basis of astrocyte-mediated neuronal synchrony and synaptic coordination, the three-dimensional relationships between cortical astrocytes and neurons was investigated. Using a transgenic and viral approach to label astrocytes with enhanced green fluorescent protein, we performed a three-dimensional reconstruction of astrocytes from tissue sections or live animals in vivo. We found that cortical astrocytes occupy nonoverlapping territories similar to those described in the hippocampus. Using immunofluorescence labeling of neuronal somata, a single astrocyte enwraps on average four neuronal somata with an upper limit of eight. Single-neuron dye-fills allowed us to estimate that one astrocyte contacts 300-600 neuronal dendrites. Together with the recent findings showing that glial Ca2+ signaling is restricted to individual astrocytes in vivo, and that Ca2+ signaling leads to gliotransmission, we propose the concept of functional islands of synapses in which groups of synapses confined within the boundaries of an individual astrocyte are modulated by the gliotransmitter environment controlled by that astrocyte. Our description offers a new structurally based conceptual framework to evaluate functional data involving interactions between neurons and astrocytes in the mammalian brain.

negative: International standards for fetal growth based on serial ultrasound measurements: the Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project. BACKGROUND In 2006, WHO produced international growth standards for infants and children up to age 5 years on the basis of recommendations from a WHO expert committee. Using the same methods and conceptual approach, the Fetal Growth Longitudinal Study (FGLS), part of the INTERGROWTH-21(st) Project, aimed to develop international growth and size standards for fetuses. METHODS The multicentre, population-based FGLS assessed fetal growth in geographically defined urban populations in eight countries, in which most of the health and nutritional needs of mothers were met and adequate antenatal care was provided. We used ultrasound to take fetal anthropometric measurements prospectively from 14 weeks and 0 days of gestation until birth in a cohort of women with adequate health and nutritional status who were at low risk of intrauterine growth restriction. All women had a reliable estimate of gestational age confirmed by ultrasound measurement of fetal crown-rump length in the first trimester. The five primary ultrasound measures of fetal growth--head circumference, biparietal diameter, occipitofrontal diameter, abdominal circumference, and femur length--were obtained every 5 weeks (within 1 week either side) from 14 weeks to 42 weeks of gestation. The best fitting curves for the five measures were selected using second-degree fractional polynomials and further modelled in a multilevel framework to account for the longitudinal design of the study. FINDINGS We screened 13,108 women commencing antenatal care at less than 14 weeks and 0 days of gestation, of whom 4607 (35%) were eligible. 4321 (94%) eligible women had pregnancies without major complications and delivered live singletons without congenital malformations (the analysis population). We documented very low maternal and perinatal mortality and morbidity, confirming that the participants were at low risk of adverse outcomes. For each of the five fetal growth measures, the mean differences between the observed and smoothed centiles for the 3rd, 50th, and 97th centiles, respectively, were small: 2·25 mm (SD 3·0), 0·02 mm (3·0), and -2·69 mm (3·2) for head circumference; 0·83 mm (0·9), -0·05 mm (0·8), and -0·84 mm (1·0) for biparietal diameter; 0·63 mm (1·2), 0·04 mm (1·1), and -1·05 mm (1·3) for occipitofrontal diameter; 2·99 mm (3·1), 0·25 mm (3·2), and -4·22 mm (3·7) for abdominal circumference; and 0·62 mm (0·8), 0·03 mm (0·8), and -0·65 mm (0·8) for femur length. We calculated the 3rd, 5th 10th, 50th, 90th, 95th and 97th centile curves according to gestational age for these ultrasound measures, representing the international standards for fetal growth. INTERPRETATION We recommend these international fetal growth standards for the clinical interpretation of routinely taken ultrasound measurements and for comparisons across populations. FUNDING Bill & Melinda Gates Foundation.

negative: Long-term effects of continuing adjuvant tamoxifen to 10 years versus stopping at 5 years after diagnosis of oestrogen receptor-positive breast cancer: ATLAS, a randomised trial BACKGROUND For women with oestrogen receptor (ER)-positive early breast cancer, treatment with tamoxifen for 5 years substantially reduces the breast cancer mortality rate throughout the first 15 years after diagnosis. We aimed to assess the further effects of continuing tamoxifen to 10 years instead of stopping at 5 years. METHODS In the worldwide Adjuvant Tamoxifen: Longer Against Shorter (ATLAS) trial, 12,894 women with early breast cancer who had completed 5 years of treatment with tamoxifen were randomly allocated to continue tamoxifen to 10 years or stop at 5 years (open control). Allocation (1:1) was by central computer, using minimisation. After entry (between 1996 and 2005), yearly follow-up forms recorded any recurrence, second cancer, hospital admission, or death. We report effects on breast cancer outcomes among the 6846 women with ER-positive disease, and side-effects among all women (with positive, negative, or unknown ER status). Long-term follow-up still continues. This study is registered, number ISRCTN19652633. FINDINGS Among women with ER-positive disease, allocation to continue tamoxifen reduced the risk of breast cancer recurrence (617 recurrences in 3428 women allocated to continue vs 711 in 3418 controls, p=0·002), reduced breast cancer mortality (331 deaths vs 397 deaths, p=0·01), and reduced overall mortality (639 deaths vs 722 deaths, p=0·01). The reductions in adverse breast cancer outcomes appeared to be less extreme before than after year 10 (recurrence rate ratio [RR] 0·90 [95% CI 0·79–1·02] during years 5–9 and 0·75 [0·62–0·90] in later years; breast cancer mortality RR 0·97 [0·79–1·18] during years 5–9 and 0·71 [0·58–0·88] in later years). The cumulative risk of recurrence during years 5–14 was 21·4% for women allocated to continue versus 25·1% for controls; breast cancer mortality during years 5–14 was 12·2% for women allocated to continue versus 15·0% for controls (absolute mortality reduction 2·8%). Treatment allocation seemed to have no effect on breast cancer outcome among 1248 women with ER-negative disease, and an intermediate effect among 4800 women with unknown ER status. Among all 12,894 women, mortality without recurrence from causes other than breast cancer was little affected (691 deaths without recurrence in 6454 women allocated to continue versus 679 deaths in 6440 controls; RR 0·99 [0·89–1·10]; p=0·84). For the incidence (hospitalisation or death) rates of specific diseases, RRs were as follows: pulmonary embolus 1·87 (95% CI 1·13–3·07, p=0·01 [including 0·2% mortality in both treatment groups]), stroke 1·06 (0·83–1·36), ischaemic heart disease 0·76 (0·60–0·95, p=0·02), and endometrial cancer 1·74 (1·30–2·34, p=0·0002). The cumulative risk of endometrial cancer during years 5–14 was 3·1% (mortality 0·4%) for women allocated to continue versus 1·6% (mortality 0·2%) for controls (absolute mortality increase 0·2%). INTERPRETATION For women with ER-positive disease, continuing tamoxifen to 10 years rather than stopping at 5 years produces a further reduction in recurrence and mortality, particularly after year 10. These results, taken together with results from previous trials of 5 years of tamoxifen treatment versus none, suggest that 10 years of tamoxifen treatment can approximately halve breast cancer mortality during the second decade after diagnosis. FUNDING Cancer Research UK, UK Medical Research Council, AstraZeneca UK, US Army, EU-Biomed.

negative: Identification of an allele of VAM3/SYP22 that confers a semi-dwarf phenotype in Arabidopsis thaliana. The short stem and midrib (ssm) mutants of Arabidopsis thaliana show both semi-dwarf and wavy leaf phenotypes due to defects in the elongation of the stem internodes and leaves. Moreover, these abnormalities cannot be recovered by exogenous phytohormones. ssm was originally identified as a single recessive mutant of the ecotype Columbia (Col-0), but genetic crossing experiments have revealed that this mutant phenotype is restored by another gene that is functional in the ecotype Landsberg erecta (Ler) and not in Col-0. Map-based cloning of the gene that is defective in ssm mutants has uncovered a small deletion in the sixth intron of a gene encoding a syntaxin, VAM3/SYP22, which has been implicated in vesicle transport to the vacuole. This mutation appears to cause a peptide insertion in the deduced VAM3/SYP22 polypeptide sequence due to defective splicing of the shortened sixth intron. Significantly, when compared with the wild-type Ler genome, the wild-type Col-0 genome has a single base pair deletion causing a frameshift mutation in SYP23, a gene with the highest known homology to VAM3/SYP22. These findings suggest that VAM3/SYP22 and SYP23 have overlapping functions and that the vesicle transport mediated by these syntaxins is important for shoot morphogenesis.

negative: Topical application of chlorhexidine to neonatal umbilical cords for prevention of omphalitis and neonatal mortality in a rural district of Pakistan: a community-based, cluster-randomised trial. BACKGROUND Umbilical cord infection (omphalitis) is a risk factor for neonatal sepsis and mortality in low-resource settings where home deliveries are common. We aimed to assess the effect of umbilical-cord cleansing with 4% chlorhexidine (CHX) solution, with or without handwashing with antiseptic soap, on the incidence of omphalitis and neonatal mortality. METHODS We did a two-by-two factorial, cluster-randomised trial in Dadu, a rural area of Sindh province, Pakistan. Clusters were defined as the population covered by a functional traditional birth attendant (TBA), and were randomly allocated to one of four groups (groups A to D) with a computer-generated random number sequence. Implementation and data collection teams were masked to allocation. Liveborn infants delivered by participating TBAs who received birth kits were eligible for enrolment in the study. One intervention comprised birth kits containing 4% CHX solution for application to the cord at birth by TBAs and once daily by family members for up to 14 days along with soap and educational messages promoting handwashing. One intervention was CHX solution only and another was handwashing only. Standard dry cord care was promoted in the control group. The primary outcomes were incidence of neonatal omphalitis and neonatal mortality. The trial is registered with ClinicalTrials.gov, number NCT00682006. FINDINGS 187 clusters were randomly allocated to one of the four study groups. Of 9741 newborn babies delivered by participating TBAs, factorial analysis indicated a reduction in risk of omphalitis with CHX application (risk ratio [RR]=0·58, 95% CI 0·41-0·82; p=0·002) but no evidence of an effect of handwashing (RR=0·83, 0·61-1·13; p=0·24). We recorded strong evidence of a reduction in neonatal mortality in neonates who received CHX cleansing (RR=0·62, 95 % CI 0·45-0·85; p=0·003) but no evidence of an effect of handwashing promotion on neonatal mortality (RR=1·08, 0·79-1·48; p=0·62). We recorded no serious adverse events. INTERPRETATION Application of 4% CHX to the umbilical cord was effective in reducing the risk of omphalitis and neonatal mortality in rural Pakistan. Provision of CHX in birth kits might be a useful strategy for the prevention of neonatal mortality in high-mortality settings. FUNDING The United States Agency for International Development.

negative: Effect of mammographic screening from age 40 years on breast cancer mortality in the UK Age trial at 17 years' follow-up: a randomised controlled trial. BACKGROUND Age-specific effects of mammographic screening, and the timing of such effects, are a matter of debate. The results of the UK Age trial, which compared the effect of invitation to annual mammographic screening from age 40 years with commencement of screening at age 50 years on breast cancer mortality, have been reported at 10 years of follow-up and showed no significant difference in mortality between the trial groups. Here, we report the results of the UK Age trial after 17 years of follow-up. METHODS Women aged 39-41 from 23 UK NHS Breast Screening Programme units years were randomly assigned by individual randomisation (1:2) to either an intervention group offered annual screening by mammography up to and including the calendar year of their 48th birthday or to a control group receiving usual medical care (invited for screening at age 50 years and every 3 years thereafter). Both groups were stratified by general practice. We compared breast cancer incidence and mortality by time since randomisation. Analyses included all women randomly assigned who could be traced with the National Health Service Central Register and who had not died or emigrated before entry. The primary outcome measures were mortality from breast cancer (defined as deaths with breast cancer coded as the underlying cause of death) and breast cancer incidence, including in-situ, invasive, and total incidence. Because there is an interest in the timing of the mortality effect, we analysed the results in different follow-up periods. This trial is registered, number ISRCTN24647151. FINDINGS Between Oct 14, 1990, and Sept 25, 1997, 160 921 participants were randomly assigned; 53 883 women in the intervention group and 106 953 assigned to usual medical care were included in this analysis. After a median follow-up of 17 years (IQR 16·8-18·8), the rate ratio (RR) for breast cancer mortality was 0·88 (95% CI 0·74-1·04) from tumours diagnosed during the intervention phase. A significant reduction in breast cancer mortality was noted in the intervention group compared with the control group in the first 10 years after diagnosis (RR 0·75, 0·58-0·97) but not thereafter (RR 1·02, 0·80-1·30) from tumours diagnosed during the intervention phase. The overall breast cancer incidence during 17 year follow-up was similar between the intervention group and the control group (RR 0·98, 0·93-1·04). INTERPRETATION Our results support an early reduction in mortality from breast cancer with annual mammography screening in women aged 40-49 years. Further data are needed to fully understand long-term effects. Cumulative incidence figures suggest at worst a small amount of overdiagnosis. FUNDING National Institute for Health Research Health Technology Assessment programme and the American Cancer Society. Past funding was received from the Medical Research Council, Cancer Research UK, the UK Department of Health, and the US National Cancer Institute.

negative: Body-mass index and risk of 22 specific cancers: a population-based cohort study of 5·24 million UK adults BACKGROUND High body-mass index (BMI) predisposes to several site-specific cancers, but a large-scale systematic and detailed characterisation of patterns of risk across all common cancers adjusted for potential confounders has not previously been undertaken. We aimed to investigate the links between BMI and the most common site-specific cancers. METHODS With primary care data from individuals in the Clinical Practice Research Datalink with BMI data, we fitted Cox models to investigate associations between BMI and 22 of the most common cancers, adjusting for potential confounders. We fitted linear then non-linear (spline) models; investigated effect modification by sex, menopausal status, smoking, and age; and calculated population effects. FINDINGS 5·24 million individuals were included; 166,955 developed cancers of interest. BMI was associated with 17 of 22 cancers, but effects varied substantially by site. Each 5 kg/m(2) increase in BMI was roughly linearly associated with cancers of the uterus (hazard ratio [HR] 1·62, 99% CI 1·56-1·69; p<0·0001), gallbladder (1·31, 1·12-1·52; p<0·0001), kidney (1·25, 1·17-1·33; p<0·0001), cervix (1·10, 1·03-1·17; p=0·00035), thyroid (1·09, 1·00-1·19; p=0·0088), and leukaemia (1·09, 1·05-1·13; p≤0·0001). BMI was positively associated with liver (1·19, 1·12-1·27), colon (1·10, 1·07-1·13), ovarian (1·09, 1.04-1.14), and postmenopausal breast cancers (1·05, 1·03-1·07) overall (all p<0·0001), but these effects varied by underlying BMI or individual-level characteristics. We estimated inverse associations with prostate and premenopausal breast cancer risk, both overall (prostate 0·98, 0·95-1·00; premenopausal breast cancer 0·89, 0·86-0·92) and in never-smokers (prostate 0·96, 0·93-0·99; premenopausal breast cancer 0·89, 0·85-0·94). By contrast, for lung and oral cavity cancer, we observed no association in never smokers (lung 0·99, 0·93-1·05; oral cavity 1·07, 0·91-1·26): inverse associations overall were driven by current smokers and ex-smokers, probably because of residual confounding by smoking amount. Assuming causality, 41% of uterine and 10% or more of gallbladder, kidney, liver, and colon cancers could be attributable to excess weight. We estimated that a 1 kg/m(2) population-wide increase in BMI would result in 3790 additional annual UK patients developing one of the ten cancers positively associated with BMI. INTERPRETATION BMI is associated with cancer risk, with substantial population-level effects. The heterogeneity in the effects suggests that different mechanisms are associated with different cancer sites and different patient subgroups. FUNDING National Institute for Health Research, Wellcome Trust, and Medical Research Council.

negative: Dementia incidence and mortality in middle-income countries, and associations with indicators of cognitive reserve: a 10/66 Dementia Research Group population-based cohort study BACKGROUND Results of the few cohort studies from countries with low incomes or middle incomes suggest a lower incidence of dementia than in high-income countries. We assessed incidence of dementia according to criteria from the 10/66 Dementia Research Group and Diagnostic and Statistical Manual of Mental Disorders (DSM) IV, the effect of dementia at baseline on mortality, and the independent effects of age, sex, socioeconomic position, and indicators of cognitive reserve. METHODS We did a population-based cohort study of all people aged 65 years and older living in urban sites in Cuba, the Dominican Republic, and Venezuela, and rural and urban sites in Peru, Mexico, and China, with ascertainment of incident 10/66 and DSM-IV dementia 3-5 years after cohort inception. We used questionnaires to obtain information about age in years, sex, educational level, literacy, occupational attainment, and number of household assets. We obtained information about mortality from all sites. For participants who had died, we interviewed a friend or relative to ascertain the likelihood that they had dementia before death. FINDINGS 12,887 participants were interviewed at baseline. 11,718 were free of dementia, of whom 8137 (69%) were reinterviewed, contributing 34,718 person-years of follow-up. Incidence for 10/66 dementia varied between 18·2 and 30·4 per 1000 person-years, and were 1·4-2·7 times higher than were those for DSM-IV dementia (9·9-15·7 per 1000 person-years). Mortality hazards were 1·56-5·69 times higher in individuals with dementia at baseline than in those who were dementia-free. Informant reports suggested a high incidence of dementia before death; overall incidence might be 4-19% higher if these data were included. 10/66 dementia incidence was independently associated with increased age (HR 1·67; 95% CI 1·56-1·79), female sex (0·72; 0·61-0·84), and low education (0·89; 0·81-0·97), but not with occupational attainment (1·04; 0·95-1·13). INTERPRETATION Our results provide supportive evidence for the cognitive reserve hypothesis, showing that in middle-income countries as in high-income countries, education, literacy, verbal fluency, and motor sequencing confer substantial protection against the onset of dementia. FUNDING Wellcome Trust Health Consequences of Population Change Programme, WHO, US Alzheimer's Association, FONACIT/ CDCH/ UCV.

negative: Dietary quality among men and women in 187 countries in 1990 and 2010: a systematic assessment BACKGROUND Healthy dietary patterns are a global priority to reduce non-communicable diseases. Yet neither worldwide patterns of diets nor their trends with time are well established. We aimed to characterise global changes (or trends) in dietary patterns nationally and regionally and to assess heterogeneity by age, sex, national income, and type of dietary pattern. METHODS In this systematic assessment, we evaluated global consumption of key dietary items (foods and nutrients) by region, nation, age, and sex in 1990 and 2010. Consumption data were evaluated from 325 surveys (71·7% nationally representative) covering 88·7% of the global adult population. Two types of dietary pattern were assessed: one reflecting greater consumption of ten healthy dietary items and the other based on lesser consumption of seven unhealthy dietary items. The mean intakes of each dietary factor were divided into quintiles, and each quintile was assigned an ordinal score, with higher scores being equivalent to healthier diets (range 0-100). The dietary patterns were assessed by hierarchical linear regression including country, age, sex, national income, and time as exploratory variables. FINDINGS From 1990 to 2010, diets based on healthy items improved globally (by 2·2 points, 95% uncertainty interval (UI) 0·9 to 3·5), whereas diets based on unhealthy items worsened (-2·5, -3·3 to -1·7). In 2010, the global mean scores were 44·0 (SD 10·5) for the healthy pattern and 52·1 (18·6) for the unhealthy pattern, with weak intercorrelation (r=-0·08) between countries. On average, better diets were seen in older adults compared with younger adults, and in women compared with men (p<0·0001 each). Compared with low-income nations, high-income nations had better diets based on healthy items (+2·5 points, 95% UI 0·3 to 4·1), but substantially poorer diets based on unhealthy items (-33·0, -37·8 to -28·3). Diets and their trends were very heterogeneous across the world regions. For example, both types of dietary patterns improved in high-income countries, but worsened in some low-income countries in Africa and Asia. Middle-income countries showed the largest improvement in dietary patterns based on healthy items, but the largest deterioration in dietary patterns based on unhealthy items. INTERPRETATION Consumption of healthy items improved, while consumption of unhealthy items worsened across the world, with heterogeneity across regions and countries. These global data provide the best estimates to date of nutrition transitions across the world and inform policies and priorities for reducing the health and economic burdens of poor diet quality. FUNDING The Bill & Melinda Gates Foundation and Medical Research Council.

negative: The effect of folate fortification on folic acid-based homocysteine-lowering intervention and stroke risk: a meta-analysis. OBJECTIVE Folate and vitamin B12 are two vital regulators in the metabolic process of homocysteine, which is a risk factor of atherothrombotic events. Low folate intake or low plasma folate concentration is associated with increased stroke risk. Previous randomized controlled trials presented discordant findings in the effect of folic acid supplementation-based homocysteine lowering on stroke risk. The aim of the present review was to perform a meta-analysis of relevant randomized controlled trials to check the how different folate fortification status might affect the effects of folic acid supplementation in lowering homocysteine and reducing stroke risk. DESIGN Relevant randomized controlled trials were identified through formal literature search. Homocysteine reduction was compared in subgroups stratified by folate fortification status. Relative risks with 95 % confidence intervals were used as a measure to assess the association between folic acid supplementation and stroke risk. SETTING The meta-analysis included fourteen randomized controlled trials,   SUBJECTS A total of 39 420 patients. RESULTS Homocysteine reductions were 26·99 (sd 1·91) %, 18·38 (sd 3·82) % and 21·30 (sd 1·98) %, respectively, in the subgroups without folate fortification, with folate fortification and with partial folate fortification. Significant difference was observed between the subgroups with folate fortification and without folate fortification (P=0·05). The relative risk of stroke was 0·88 (95 % CI 0·77, 1·00, P=0·05) in the subgroup without folate fortification, 0·94 (95 % CI 0·58, 1·54, P=0·82) in the subgroup with folate fortification and 0·91 (95 % CI 0·82, 1·01, P=0·09) in the subgroup with partial folate fortification. CONCLUSIONS Folic acid supplementation might have a modest benefit on stroke prevention in regions without folate fortification.