CTL activation is induced by cross-linking of TCR/MHC-peptide-CD8/p56lck adducts in rafts.

To investigate the role of the coreceptor CD8 and lipid rafts in cytotoxic T lymphocyte (CTL) activation, we used soluble mono-and multimeric H-2Kd-peptide complexes and cloned S14 CTL specific for a photoreactive derivative of the Plasmodium berghei circumsporozoite (PbCS) peptide 252-260 [PbCS(ABA)]. We report that activation of CTL in suspension requires multimeric Kd-PbCS(ABA) complexes co-engaging TCR and CD8. Using TCR ligand photo-cross-linking, we find that monomeric Kd-PbCS(ABA) complexes promote association of TCR/CD3 with CD8/p56lck. Dimerization of these adducts results in activation of p56lck in lipid rafts, where phosphatases are excluded. Additional cross-linking further increases p56lck kinase activity, induces translocation of TCR/CD3 and other signaling molecules to lipid rafts and intracellular calcium mobilization. These events are prevented by blocking Src kinases or CD8 binding to TCR-associated Kd molecules, indicating that CTL activation is initiated by cross-linking of CD8-associated p56lck. They are also inhibited by methyl-beta-cyclodextrin, which disrupts rafts and by dipalmitoyl phosphatidylethanolamine, which interferes with TCR signaling. Because efficient association of CD8 and p56lck takes place in rafts, both reagents, though in different ways, impair coupling of p56lck to TCR, thereby inhibiting the initial and essential activation of p56lck induced by cross-linking of engaged TCR.

Reduction in the expression of glucose transporter protein GLUT 2 in preneoplastic and neoplastic hepatic lesions and reexpression of GLUT 1 in late stages of hepatocarcinogenesis.

Expression of two important glucose transporter proteins, GLUT 2 (which is the typical glucose transporter in hepatocytes of adult liver) and the erythroid/brain type glucose transporter GLUT 1 (representing the typical glucose transporter in fetal liver parenchyma), was studied immunocytochemically during hepatocarcinogenesis in rats at different time points between 7 and 65 wk after cessation of 7-wk administration of 12 mg/kg of body weight of N-nitrosomorpholine p.o. (stop model). Foci of altered hepatocytes excessively storing glycogen (GSF) and mixed cell foci (MCF) composed of both glycogenotic and glycogen-poor cells were present at all time points studied. Seven wk after withdrawal of the carcinogen, GSF were the predominant type of focus of altered hepatocytes. Morphometrical evaluation of the focal lesions revealed that the number and volume fraction of GSF increased steadily until Wk 65. MCF were rare at 7 wk, increased slightly in number and size until Wk 37, but showed a pronounced elevation in their number and volume fraction from Wk 37 to Wk 65. In both GSF and MCF, GLUT 2 was generally decreased or partially absent at all time points. Consequently, foci of decreased GLUT 2 expression showed a steady increase in number and volume fraction from Wk 7 to Wk 65. GLUT 1 was lacking in GSF but occurred in some MCF from Wk 50 onward. The liver type glucose transporter GLUT 2 was decreased in all adenomas and hepatocellular carcinomas (HCC). In three of seven adenomas and 10 of 12 carcinomas, expression of GLUT 1 was increased compared with normal liver parenchyma. In two cases of adenoid HCC, cells of ductular formations coexpressed GLUT 2 and GLUT 1. In contrast, normal bile ducts, bile duct proliferations, and cystic cholangiomas expressed only GLUT 1. Seven of 12 HCC contained many microvessels intensely stained for GLUT 1, a phenomenon never observed in normal liver. Whenever adenoid tumor formations occurred, GLUT 1-positive microvessels were located in the immediate vicinity of these formations. Only in one HCC were such microvessels found in the absence of adenoid formations. Our studies indicate that a reduction of GLUT 2 expression occurs already in early preneoplastic hepatic foci and is maintained throughout hepatocarcinogenesis, including benign and malignant neoplasms. Reexpression of GLUT 1, however, appears in a few MCF and in the majority of adenomas and carcinomas.

A comprehensive characterization of genome-wide copy number aberrations in colorectal cancer reveals novel oncogenes and patterns of alterations.

To develop a comprehensive overview of copy number aberrations (CNAs) in stage-II/III colorectal cancer (CRC), we characterized 302 tumors from the PETACC-3 clinical trial. Microsatellite-stable (MSS) samples (n = 269) had 66 minimal common CNA regions, with frequent gains on 20 q (72.5%), 7 (41.8%), 8 q (33.1%) and 13 q (51.0%) and losses on 18 (58.6%), 4 q (26%) and 21 q (21.6%). MSS tumors have significantly more CNAs than microsatellite-instable (MSI) tumors: within the MSI tumors a novel deletion of the tumor suppressor WWOX at 16 q23.1 was identified (p<0.01). Focal aberrations identified by the GISTIC method confirmed amplifications of oncogenes including EGFR, ERBB2, CCND1, MET, and MYC, and deletions of tumor suppressors including TP53, APC, and SMAD4, and gene expression was highly concordant with copy number aberration for these genes. Novel amplicons included putative oncogenes such as WNK1 and HNF4A, which also showed high concordance between copy number and expression. Survival analysis associated a specific patient segment featured by chromosome 20 q gains to an improved overall survival, which might be due to higher expression of genes such as EEF1B2 and PTK6. The CNA clustering also grouped tumors characterized by a poor prognosis BRAF-mutant-like signature derived from mRNA data from this cohort. We further revealed non-random correlation between CNAs among unlinked loci, including positive correlation between 20 q gain and 8 q gain, and 20 q gain and chromosome 18 loss, consistent with co-selection of these CNAs. These results reinforce the non-random nature of somatic CNAs in stage-II/III CRC and highlight loci and genes that may play an important role in driving the development and outcome of this disease.

Communally breeding Bechstein's bats have a stable social system that is independent from the postglacial history and location of the populations.

Investigating macro-geographical genetic structures of animal populations is crucial to reconstruct population histories and to identify significant units for conservation. This approach may also provide information about the intraspecific flexibility of social systems. We investigated the history and current structure of a large number of populations in the communally breeding Bechstein's bat (Myotis bechsteinii). Our aim was to understand which factors shape the species' social system over a large ecological and geographical range. Using sequence data from one coding and one noncoding mitochondrial DNA region, we identified the Balkan Peninsula as the main and probably only glacial refugium of the species in Europe. Sequence data also suggest the presence of a cryptic taxon in the Caucasus and Anatolia. In a second step, we used seven autosomal and two mitochondrial microsatellite loci to compare population structures inside and outside of the Balkan glacial refugium. Central European and Balkan populations both were more strongly differentiated for mitochondrial DNA than for nuclear DNA, had higher genetic diversities and lower levels of relatedness at swarming (mating) sites than in maternity (breeding) colonies, and showed more differentiation between colonies than between swarming sites. All these suggest that populations are shaped by strong female philopatry, male dispersal, and outbreeding throughout their European range. We conclude that Bechstein's bats have a stable social system that is independent from the postglacial history and location of the populations. Our findings have implications for the understanding of the benefits of sociality in female Bechstein's bats and for the conservation of this endangered species.

RXR: from partnership to leadership in metabolic regulations.

Vitamin A signaling occurs through nuclear receptors recognizing diverse forms of retinoic acid (RA). The retinoic acid receptors (RARs) bind all-trans RA and its 9-cis isomer (9-cis RA). They convey most of the activity of RA, particularly during embryogenesis. The second subset of receptors, the rexinoid receptors (RXRs), binds 9-cis RA only. However, RXRs are obligatory DNA-binding partners for a number of nuclear receptors, broadening the spectrum of their biological activity to the corresponding nuclear receptor-signaling pathways. The present chapter more particularly focuses on RXR-containing transcriptional complexes for which RXR is not only a structural component necessary for DNA binding but also acts as a ligand-activated partner. After positioning RXR among the nuclear receptor superfamily in the first part, we will give an overview of three major signaling pathways involved in metabolism, which are sensitive to RXR activation: LXR:RXR, FXR:RXR, and PPAR:RXR. The third and last part is focused on RXR signaling and its potential role in metabolic regulation. Indeed, while the nature of the endogenous ligand for RXR is still in question, as we will discuss herein, a better understanding of RXR activities is necessary to envisage the potential therapeutic applications of synthetic RXR ligands.

Reducing the number of young people not in employment, education or training (NEET)

Evidence Review 3 - Reducing the number of young people not in employment, education or training (NEET) Briefing 3 - Reducing the number of young people not in employment, education or training (NEET) This pair of documents, commissioned by Public Health England, and written by the UCL Institute of Health Equity, examine how to help young people into employment, education or training. They describe the relationship between being NEET and health; inequalities in prevalence of being NEET; and the scale of the problem. The papers show that being NEET, particularly for prolonged periods, is associated with negative effects on health and a range of other outcomes. Furthermore, the chances of becoming NEET are not equally or randomly distributed throughout society – those who are relatively disadvantaged, from poor backgrounds, or who have had negative experiences at school are more likely to spend some time being NEET. The papers also propose actions that can be taken at a local level in order to reduce the proportion of young people who are NEET. There is good evidence on what works in order to enable and support young people to enter employment, education and training. Taking action to reduce NEET levels is both possible and necessary – both to ensure young people have opportunities, and also as an important way to improve public health and reduce inequalities. The full evidence review and a shorter summary briefing are available to download above. This document is part of a series. An overview document which provides an introduction to this and other documents in the series, and links to the other topic areas, is available on the ‘Local Action on health inequalities’ project page. A video of Michael Marmot introducing the work is also available on our videos page.

A Study of the Number, Profile and Progression Routes of Homeless Persons before the Court and in Custody

This study aimed to obtain information on homeless people appearing before the courts and in custody in the Dublin Metropolitan area and to track and to determine how homeless persons progress through the court and prison systems. The overall objective was to provide information the Probation and Welfare Service's processes of policy formation, service development and planning. Findings on the number of homeless offenders, their profile, their progression routes into the criminal justice system and prisoner reintegration are presented. Recommendations are made regarding sentencing policy, agency responsibility for ex-prisoners and appropriate issues for discussion by the Cross Departmental Committee on Homelessness. It is also recommended that drug free units be available across all closed regime prison establishments.This resource was contributed by The National Documentation Centre on Drug Use.

Impact of a computerized physician order entry system on compliance with prescription accuracy requirements.

OBJECTIVE: To assess the change in non-compliant items in prescription orders following the implementation of a computerized physician order entry (CPOE) system named PreDiMed. SETTING: The department of internal medicine (39 and 38 beds) in two regional hospitals in Canton Vaud, Switzerland. METHOD: The prescription lines in 100 pre- and 100 post-implementation patients' files were classified according to three modes of administration (medicines for oral or other non-parenteral uses; medicines administered parenterally or via nasogastric tube; pro re nata (PRN), as needed) and analyzed for a number of relevant variables constitutive of medical prescriptions. MAIN OUTCOME MEASURE: The monitored variables depended on the pharmaceutical category and included mainly name of medicine, pharmaceutical form, posology and route of administration, diluting solution, flow rate and identification of prescriber. RESULTS: In 2,099 prescription lines, the total number of non-compliant items was 2,265 before CPOE implementation, or 1.079 non-compliant items per line. Two-thirds of these were due to missing information, and the remaining third to incomplete information. In 2,074 prescription lines post-CPOE implementation, the number of non-compliant items had decreased to 221, or 0.107 non-compliant item per line, a dramatic 10-fold decrease (chi(2) = 4615; P < 10(-6)). Limitations of the computerized system were the risk for erroneous items in some non-prefilled fields and ambiguity due to a field with doses shown on commercial products. CONCLUSION: The deployment of PreDiMed in two departments of internal medicine has led to a major improvement in formal aspects of physicians' prescriptions. Some limitations of the first version of PreDiMed were unveiled and are being corrected.

A Study of the Epidemiology of AIDS in Ireland and an Evaluation of an AIDS Education Programme in Second-level Schools

Second-level school students have been identified by the Minister for health as a priority group for education on AIDS. An education programme was accordingly initiated in 1988 in Community Care Area 1 in South county Dublin. This report evaluates this education intervention by means of pre- and post- intervention questionnaires. The questionnaire examined knowledge and attitudes of students relevant to AIDS. The results showed that the level of knowledge of students living in this area was high prior to intervention. The education programme succeeded in improving some aspects of knowledge and also influenced some attitudes of the students. A study of the epidemiology of Aids in Ireland reveals that the epidemic is at a relatively early stage with a consequent rapid doubling time of 9-10 months. In comparison with most developed countries Ireland has a high proportion of AIDS cases occurring among intravenous drug abusers and directly related to this a high number of HIV infected children. Examination of the literature reveals that behaviour change has occurred most noticeably among the homosexual/bisexual risk group. There is some evidence that the comprehensive programmes can achieve change in the behaviour of intravenous drug abusers. There are very few reports linking behaviour change among adolescents and young adults to education programmes. Much of the available literature relates to changes in knowledge and attitudes. International recommendations on the nature of the ideal health education intervention on AIDS are reviewed. The importance of a comprehensive health education programme which incorporates AIDS education and which commences early in youth is noted. The role of the community physician in relation to education programmes and other aspects of monitoring and management of the AIDS epidemic is discussed.This resource was contributed by The National Documentation Centre on Drug Use.

Why do scientists migrate? A diffusion model

The article is intended to improve our understanding of the reasons underlying the intellectual migration of scientists from well-known cognitive domains to nascent scientific fields. To that purpose we present, first, a number of findings from the sociology of science that give different insights about this phenomenon. We then attempt to bring some of these insights together under the conceptual roof of an actor-based approach linking expected utility and diffusion theory. Intellectual migration is regarded as the rational choice of scientists who decide under uncertainty and on the base of a number of decision-making variables, which define probabilities, costs, and benefits of the migration.

The number of families of Triatoma dimidiata in a Guatemalan house

Triatoma dimidiata is an important vector of Chagas disease in Guatemala. To help understand the biology and population dynamics of the insect, we estimated the number of full sibling families living in one house. Forty one families with an average size of 2.17 individuals were detected using random amplification of polymorphic DNA-polymerase chain reaction genetic markers. This result suggests high levels of migration of the vector, polyandry, and a significant capability for spreading the disease.

Gene finding in the chicken genome.

BACKGROUND: Despite the continuous production of genome sequence for a number of organisms, reliable, comprehensive, and cost effective gene prediction remains problematic. This is particularly true for genomes for which there is not a large collection of known gene sequences, such as the recently published chicken genome. We used the chicken sequence to test comparative and homology-based gene-finding methods followed by experimental validation as an effective genome annotation method. RESULTS: We performed experimental evaluation by RT-PCR of three different computational gene finders, Ensembl, SGP2 and TWINSCAN, applied to the chicken genome. A Venn diagram was computed and each component of it was evaluated. The results showed that de novo comparative methods can identify up to about 700 chicken genes with no previous evidence of expression, and can correctly extend about 40% of homology-based predictions at the 5' end. CONCLUSIONS: De novo comparative gene prediction followed by experimental verification is effective at enhancing the annotation of the newly sequenced genomes provided by standard homology-based methods.

Thyroid hormone enhances transected axonal regeneration and muscle reinnervation following rat sciatic nerve injury.

Improvement of nerve regeneration and functional recovery following nerve injury is a challenging problem in clinical research. We have already shown that following rat sciatic nerve transection, the local administration of triiodothyronine (T3) significantly increased the number and the myelination of regenerated axons. Functional recovery is a sum of the number of regenerated axons and reinnervation of denervated peripheral targets. In the present study, we investigated whether the increased number of regenerated axons by T3-treatment is linked to improved reinnervation of hind limb muscles. After transection of rat sciatic nerves, silicone or biodegradable nerve guides were implanted and filled with either T3 or phosphate buffer solution (PBS). Neuromuscular junctions (NMJs) were analyzed on gastrocnemius and plantar muscle sections stained with rhodamine alpha-bungarotoxin and neurofilament antibody. Four weeks after surgery, most end-plates (EPs) of operated limbs were still denervated and no effect of T3 on muscle reinnervation was detected at this stage of nerve repair. In contrast, after 14 weeks of nerve regeneration, T3 clearly enhanced the reinnervation of gastrocnemius and plantar EPs, demonstrated by significantly higher recovery of size and shape complexity of reinnervated EPs and also by increased acetylcholine receptor (AChRs) density on post synaptic membranes compared to PBS-treated EPs. The stimulating effect of T3 on EP reinnervation is confirmed by a higher index of compound muscle action potentials recorded in gastrocnemius muscles. In conclusion, our results provide for the first time strong evidence that T3 enhances the restoration of NMJ structure and improves synaptic transmission.

Copy number variation and chromatin structure

The functional consequences of structural variation in the human genome range from adaptation, to phenotypic variation, to predisposition to diseases. Copy number variation (CNV) was shown to influence the phenotype by modifying, in a somewhat dose-dependent manner, the expression of genes that map within them, as well as that of genes located on their flanks. To assess the possible mechanism(s) behind this neighboring effect, we compared histone modification status of cell lines from patients affected by Williams-Beuren, Williams-Beuren region duplication, Smith-Magenis or DiGeorge Syndrome and control individuals using a high-throughput version of chromatin immuno-precipitation method (ChIP), called ChlP-seq. We monitored monomethylation of lysine K20 on histone H4 and trimethylation of lysine K27 on histone H3, as proxies for open and condensed chromatin, respectively. Consistent with the changes in expression levels observed for multiple genes mapping on the entire length of chromosomes affected by structural variants, we also detected regions with modified histone status between samples, up- and downstream from the critical regions, up to the end of the rearranged chromosome. We also gauged the intrachromosomal interactions of these cell lines utilizing chromosome conformation capture (4C-seq) technique. We observed that a set of genes flanking the Williams-Beuren Syndrome critical region (WBSCR) were often looping together, possibly forming an interacting cluster with each other and the WBSCR. Deletion of the WBSCR disrupts the expression of this group of flanking genes, as well as long-range interactions between them and the rearranged interval. We conclude, that large genomic rearrangements can lead to changes in the state of the chromatin spreading far away from the critical region, thus possibly affecting expression globally and as a result modifying the phenotype of the patients. - Les conséquences fonctionnelles des variations structurelles dans le génome humain sont vastes, allant de l'adaptation, en passant par les variations phénotypiques, aux prédispositions à certaines maladies. Il a été démontré que les variations du nombre de copies (CNV) influencent le phénotype en modifiant, d'une manière plus ou moins dose-dépendante, l'expression des gènes se situant à l'intérieur de ces régions, mais également celle des gènes se trouvant dans les régions flanquantes. Afin d'étudier les mécanismes possibles sous-jacents à cet effet de voisinage, nous avons comparé les états de modification des histones dans des lignées cellulaires dérivées de patients atteints du syndrome de Williams-Beuren, de la duplication de la région Williams-Beuren, du syndrome de Smith-Magenis ou du syndrome de Di- George et d'individus contrôles en utilisant une version haut-débit de la méthode d'immunoprécipitation de la chromatine (ChIP), appelée ChIP-seq. Nous avons suivi la mono-méthylation de la lysine K20 sur l'histone H4 et la tri-méthylation de la lysine K27 sur l'histone H3, marqueurs respectifs de la chromatine ouverte et fermée. En accord avec les changements de niveaux d'expression observés pour de multiples gènes tout le long des chromosomes affectés par les CNVs, nous avons aussi détecté des régions présentant des modifications d'histones entre les échantillons, situées de part et d'autre des régions critiques, jusqu'aux extrémités du chromosome réarrangé. Nous avons aussi évalué les interactions intra-chromosomiques ayant lieu dans ces cellules par l'utilisation de la technique de capture de conformation des chromosomes (4C-seq). Nous avons observé qu'un groupe de gènes flanquants la région critique du syndrome de Williams-Beuren (WBSCR) forment souvent une boucle, constituant un groupe d'interactions privilégiées entre ces gènes et la WBSCR. La délétion de la WBSCR perturbe l'expression de ce groupe de gènes flanquants, mais également les interactions à grande échelle entre eux et la région réarrangée. Nous en concluons que les larges réarrangements génomiques peuvent aboutir à des changements de l'état de la chromatine pouvant s'étendre bien plus loin que la région critique, affectant donc potentiellement l'expression de manière globale et ainsi modifiant le phénotype des patients.

Bacillus subtilis alpha-phosphoglucomutase is required for normal cell morphology and biofilm formation.

Mutations designated gtaC and gtaE that affect alpha-phosphoglucomutase activity required for interconversion of glucose 6-phosphate and alpha-glucose 1-phosphate were mapped to the Bacillus subtilis pgcA (yhxB) gene. Backcrossing of the two mutations into the 168 reference strain was accompanied by impaired alpha-phosphoglucomutase activity in the soluble cell extract fraction, altered colony and cell morphology, and resistance to phages phi29 and rho11. Altered cell morphology, reversible by additional magnesium ions, may be correlated with a deficiency in the membrane glycolipid. The deficiency in biofilm formation in gtaC and gtaE mutants may be attributed to an inability to synthesize UDP-glucose, an important intermediate in a number of cell envelope biosynthetic processes.