931 resultados para When disease makes history
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A variety of behavioral disorders occurring abruptly in patients with Parkinson's disease (PD) has been recently published and attracted considerable attention in the press. Taking the form of pathological gambling, compulsive shopping, addiction to Internet and to other recreational activities, hypersexuality or bulimia, impulse control disorders (ICD) related to PD are probably more frequent than previously appreciated and may have consequences as spectacular as disastrous for the involved patients. ICD are currently viewed as particular adverse reactions to antiparkinsonian medications, notably to dopamine agonists, and, accordingly, tend to improve or disappear when PD therapy is appropriately adjusted.
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Homozygous (delta ccr5/delta ccr5) and heterozygous (CCR5/delta ccr5) deletions in the beta-chemokine receptor 5 (CCR5) gene, which encodes for the major co-receptor for macrophage-tropic HIV-1 entry, have been implicated in resistance to HIV infection and in protection against disease progression, respectively. The CCR5/delta ccr5 genotype was found more frequently in long-term nonprogressors (LTNP) (31.0%) than in progressors (10.6%, p < 0.0001), in agreement with previous studies. Kaplan-Meier survival analyses showed that a slower progression of disease, i.e. higher proportion of subjects with CD4+ T cell counts > 500/microl (p = 0.0006) and a trend toward a slower progression to AIDS (p = 0.077), was associated with the CCR5/delta ccr5 genotype. However, when LTNP were analyzed separately, no significant differences in CD4+ T cell counts (p = 0.12) and viremia levels (p = 0.65) were observed between the wild-type (69% of LTNP) and the heterozygous (31.0%) genotypes. Therefore, there are other factors which play a major role in determining the status of nonprogression in the majority of LTNP. Furthermore, there was no evidence that the CCR5/delta ccr5 genotype was associated with different rates of disease progression in the group of progressors. Taken together, these results indicate that the CCR5/delta ccr5 genotype is neither essential nor sufficient for protection against the progression of HIV disease.
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Background: Food allergy in children, an increasingly prevalent disease, significantly affects the quality of life. Its impact can be analyzed by the recently validated French version of the Food Allergy Quality of Life Questionnaire (FAQLQ). Objectives: The aim of our study was to evaluate the quality of life in a small sample of Swiss children with IgE-mediated food allergy. Methods: Information were collected with the questionnaire among 0-12 years old children and their parents during a scheduled allergy visit, and analysed in term of emotional impact, food anxiety and social and food limitations. Patients were divided according to the questionnaire in three age groups: group 1 from 0 to 3 years, group 2 from 4 to 6 years and group 3 from 7 up to 12 years. Results: 30 food allergic patients were included, with a girl/boy ratio of 1:1.14. Median age was 6 years. 56% suffered from or had a history of eczema, 23% of rhino-conjunctivitis, 30% of asthma, and 13% reported a drug allergy. None had insect venom allergy. 57% were known to be allergic to one food, 20% to two foods, 20% to 3 foods and 3% had 3 or more food allergies. Tree nuts (51% of all allergies) as well as eggs (28 %) were the major allergies. Emotional impact had a total score of 1.54 but showed differences between age groups. In group 1 it was lower with 0.23, in group 2 the score was 2.03 and 1.77 in group 3. Food anxiety total score was 1.9; 0.76 in group 1, 2.31 in group 2 and 2.23 in group 3. Social and food limitations showed similar results with a total score of 1.73 and 1.23 in group 1, 2.05 in group 2 and 1.68 for group 3. Conclusion: Food allergy affects the quality of life of Swiss children. Our preliminary results on a small sample are comparable to previously published data. We show that the impact of food allergy on daily life increases when the child starts school and social activities.
Dimethylarginines, homocysteine metabolism, and cerebrospinal fluid markers for Alzheimer's disease.
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Dimethylarginine and homocysteine metabolism are closely linked and alterations of both were observed in plasma and cerebrospinal fluid (CSF) of patients with Alzheimer's disease (AD). CSF parameters of homocysteine metabolism have recently been found to be associated with the CSF level of the AD biomarker phosphorylated tau (ptau) in AD patients. To investigate possible relationships between homocysteine and dimethylarginine metabolism and the AD CSF biomarkers ptau181 and amyloid-β 1-42 (Aβ42), we assessed parameters of homocysteine metabolism (CSF homocysteine, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), 5-methyltetrahydrofolate (5-MTHF)) and dimethylarginine metabolism (plasma and CSF asymmetric dimethylarginine (ADMA), symmetric dimethylarginine, L-arginine) as well as CSF Aβ42 and ptau181 in 98 controls and 51 AD patients. Multivariate linear regression analyses were performed to assess associations between the considered parameters. SAH concentrations show significant associations to CSF ADMA levels, and CSF ADMA and L-arginine to ptau181, but not to Aβ42 concentrations in AD patients. When including concentrations of homocysteine, 5-MTHF, SAM, and SAH into the analysis, CSF ADMA concentrations independently predicted ptau181 levels in AD patients but homocysteine-related metabolites were associated with ptau181 only when ADMA was removed from the analysis model. These results suggest that CSF ADMA may interact with CNS homocysteine metabolism and may contribute to neurodegeneration and accumulation of phosphorylated tau in AD. Functional and interventional studies are needed to further proof this hypothesis.
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BACKGROUND: Current guidelines for the prevention of cardiovascular disease (CVD) recommend diabetes as a CVD risk equivalent. However, reports that have examined the risk of diabetes in comparison to pre-existing CVD are lacking among older women. We aimed to assess whether diabetes was associated with a similar risk of total and cause-specific mortality as a history of CVD in older women. METHODOLOGY/PRINCIPAL FINDINGS: We studied 9218 women aged 68 years or older enrolled in a prospective cohort study (Study of Osteoporotic Fracture) during a mean follow-up period of 11.7 years and compared all-cause, cardiovascular and coronary heart disease mortality among 4 groups: non-diabetic women with and without existing CVD, diabetic women with and without existing CVD. Mean (SD) age of the participants was 75.2 (5.3) years, 3.5% reported diabetes and 6.8% reported existing CVD. During follow-up, 5117 women died with 36% from CVD. The multivariate adjusted risk of cardiovascular mortality was increased among both non-diabetic women with CVD (hazard ratio (HR) 2.32, 95% CI: 1.97-2.74, P<0.001) and diabetic women without CVD (HR 2.06, CI: 1.62-2.64, P<0.001) compared to non-diabetic women without existing CVD. All-cause, cardiovascular and coronary mortality of non-diabetic women with CVD were not significantly different from diabetic women without CVD. CONCLUSIONS/SIGNIFICANCE: Older diabetic women without CVD have a similar risk of cardiovascular mortality compared to non-diabetic women with pre-existing CVD. The equivalence of diabetes and CVD seems to extend to older women, supporting current guidelines for cardiovascular prevention.
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The increasing number of trials testing management strategies for luminal Crohn's disease (CD) has not fitted all the gaps in our knowledge and thus, in clinical. practice, many decisions for CD patients have to be taken without the benefit of high-quality evidence. Methods: A multidisciplinary European expert panel used the RAND Appropriateness Method to develop and rate explicit criteria for the management of individual patients with active, steroid-dependent (ST-D) and steroid-refractory (ST-R) CD. Results: Overall., 296 indications pertaining to mild-to-moderate, severe, ST-D, and ST-R CD were rated. In anti-TNF naive patients, budesonide and prednisone were found to be appropriate for mild-moderate CD, and infliximab (IFX) was appropriate when these had previously failed or had not been tolerated. In patients with a prior successful treatment by IFX, this drug, with or without co-administration of a thiopurine analog, was favoured. Other anti-TNFs were appropriate in the presence of intolerance or resistance to IFX. High-dose steroids, IFX or adlimumab were appropriate in severe active CD. For the 105 indications for ST-D or ST-R disease, the panel considered the thiopurine analogs, methotrexate, IFX, adalimumab, and surgery for limited resection, to be appropriate, depending on the outcome of prior therapies. Anti-TNFs were generally considered appropriate in ST-R. Conclusion: Steroids, including budesonide for mild-to-moderate CD, remain the first-line therapy for active luminal CD. Anti-TNFs, in particular IFX as shown by the amount of available evidence, remain the second-line therapy for most indications. Thiopurine analogs, methotrexate and anti-TNFs are favoured in ST-D patients and ST-R patients. (C) 2009 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.
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Résumé : Les corps magmatiques sont des indicateurs essentiels dans toute reconstitution paléogéographique et/ou géodynamique d'un cycle orogénique, en particulier en contexte polycyclique, où la plupart des autres indices ont été oblitérés. Ils sont aisément datables et leurs caractéristiques géochimiques permettent de contraindre leur contexte tectonique de mise en place. Cette approche a été appliquée aux socles pré-mésozoïques des nappes penniques inférieures de Sambuco et de la Maggia, dans les Alpes centrales lepontines. Plusieurs événements magmatiques ont été identifiés dans le socle de Sambuco et datés par la méthode U-Pb sur zircon couplée à la technique LA-ICPMS. La suite calco-alcaline mafique rubanée de Scheggia est datée du Cambrien inférieur à 540-530 Ma ; le métagranite alumineux oeillé de Sasso Nero a un âge de 480-470 Ma, tout comme bien d'autres «older orthogneisses» des socles alpins. Il contient des zircons hérités d'âge panafricain à 630-610 Ma, indicateur d'une affiliation gondwanienne de ces terrains. Le pluton calco-alcalin du Matorello est daté à environ 300-310 Ma, et les filons lamprophyriques qu'il abrite à 300 Ma. La granodiorite de Cocco et le leucogranite de Ruscada, tous deux intrudés dans le socle de la nappe adjacente de la Maggia, ont des âges similaires à celui du Matorello. Ceci ajouté aux similitudes magmatiques observées entre Cocco et Matorello suggère une proximité paléogéographique des deux nappes au Permien-Carbonifère. Or ces dernières sont actuellement considérées appartenir à deux domaines paléogéographiques mésozoïques distincts : helvétique pour Sambuco et briançonnais pour Maggia, séparés par un bassin océanique. Si tel fut le cas, aucun mouvement décrochant ne doit avoir décalé les marges continentales de l'océan, retrouvées en parfaite coïncidence lors de sa fermeture. Le Matorello est un pluton recristallisé en faciès amphibolite et plissé par cinq phases successives de déformation non-coaxiales, qui ont conduit à son renversement complet, attesté par des indicateurs de paléogravité. Il préserve de spectaculaires phénomènes de coexistence liquide de magmas (essaims d'enclaves et Bills composites). Ce pluton était originellement tabulaire, construit par l'accumulation de multiples injections de magma en feuillets d'épaisseur métrique à décamétrique. Suivant le rythme de mise en place, les injections successives ont rapidement cristallisé avec des contours nets et bien définis (Bills composites) ou se sont mélangées avec les précédentes pour former une couche non consolidée de plusieurs dizaines de mètres d'épaisseur (granodiorite principale). Les injections individuelles sont délimitées par de subtils contrastes en granulométrie, proportions modales ou ségrégation de minéraux (schlieren), ou par des phénomènes d'érosion le long des surfaces de contact. Deux couches métriques à contour sinueux consistent en une accumulation compacte d'enclaves mafiques arrondies dans une matrice granodioritique fine. Le granoclassement des enclaves, la présence de figures de charge et de phénomènes érosifs en base de couche, ainsi que des schlieren de biotite entrecroisés évoquent l'injection de coulées de magma chargé d'enclaves et de faible viscosité en régime hydrodynamique turbulent dans un encaissant granodioritique encore largement liquide. La nature hybride des roches implique une chambre magmatique sous-jacente, en cours de différenciation et périodiquement réalimentée. Les magmas sont des liquides mafiques dérivés du manteau et des liquides anatectiques d'origine crustale, comme l'indique la gamme mesurée des rapports isotopiques initiaux du Sr (0.704 à 0.709) et des valeurs epsilon Nd (-2.1 à -4.7). Ces données montrent également que la contribution crustale est dominante, en accord avec les isotopes du plomb. Les phénomènes d'hybridation ont vraisemblablement eu lieu en base de croûte et dans la chambre magmatique sous-jacente au laccolite du Matorello. Les indicateurs de paléogravité du Matorello contribuent accessoirement à la compréhension de l'architecture actuelle de la nappe de Sambuco. Des plis isoclinaux à surface axiale verticale peuvent être mis en évidence par le contact entre les faciès dioritique et granodioritique. L'antiforme dont le Matorello forme le coeur est un synclinal, ce qui le positionne dans le Flanc inverse du grand pli couché que forme la nappe de Sambuco. Par ailleurs, des blocs de gneiss retrouvés dans le wildflysch sommital de la couverture de la nappe d'Antigorio ont été affiliés dans cette étude au pluton du Matorello. Ceci implique que le front de la nappe de Sambuco chevauchait déjà la partie est du bassin d'Antigorio au moment de sa fermeture. Par conséquent, ce n'est qu'en position externe que la nappe du Lebendun chevauche directement la nappe d'Antigorio. Abstract Magmatic bodies are important markers in paleo-geographic or geodynamic reconstructions of orogenic cycles, even more so in the case of polycyclic events where many of the other markers have been overwritten or destroyed. Plutons are relatively easy to date and their geochemical properties help constrain the tectonic context in which they were emplaced. This study focuses on the pre-mesozoic basement in the Sambuco and Maggia lower Penninic nappes located in the central Lepontine domain of the Alps. A number of magmatic events have been identified in the Sambuco basement. These events were dated using LA-ICPMS U/Pb on zircon grains. The mafic calc-alkaline banded Scheggia suite is dated as lower Cambrian, 540-530 Ma. The Al-rich Sasso-Nero lenticular gneiss is 480-470 Ma old (similarly to many older orfhogneisses of the Alpine basement) and contains 630-610 Ma old pan-African inherited zircons that illustrate the Gondwanian origin of these terranes.The calc-alkaline Matorello pluton is dated as 310-300 Ma whereas the lamprophyric bodies it contains are of 300 Ma. The Cocco granodiorite and the Ruscada leucogranite both intrude the basement of the adjacent Maggia nappe and are of similar ages to the Matorello. The ages as well as the geochemical similarities between the Cocco, Rucada and Matorello plutons suggest their paleo-geographic proximity at the Permian-Carboniferous boundary. However, these nappes are currently considered as belonging to two different Mesozoic paleo-geographic domains. Indeed, the Sambuco is considered as Helvetic whereas the Maggia is said to be Briançonnais, both separated by an oceanic basin. If this is the case, then it is essential that nostrike-slip movement has misaligned both continental margins since these coincide perfectly now that the oceanic domain closed. The Matorello pluton was originally a tabular intrusion, built up by the accumulation of multiple, several meter-thick, subhorizontal sheet-like injections of magma. Depending on their emplacement rate, the successive magma injections either solidified rapidly with sharp and rather well-defined boundaries (like the composite sills) or mingled with previous injections generating a thick molten layer up to several tens to hundred meters thick, like in the main granodioritic facies. These coalesced injections are hardly distinguishable, however subtle contrasts in granulometry, mineral modal proportions or mineral sorting (cross-bedded biotite-rich schlieren), as well as erosional features and/or crystal entrapment along contact surfaces allow to distinguish between the different injections. Two exceptional meter-thick layers display sinuous boundaries with the host granodiorite and consist of a densely packed accumulation of mafic enclaves in a granodioritic matrix. Gravitational sorting of the enclaves with load cast features at the base of the layers and sinuous biotite schlieren point to injection of low viscosity turbulent composite magma flows in the still largely molten granodiorite host. The hybrid nature of these rocks implies the existence of á periodically replenished and differentiated underlying magma chamber. Magmas are mafic liquids derived from the mantle and anatectic liquids of crustal origin, as shown by the (87Sr/86Sr), and epsilon Nd values (0.704-0.709 and -2.1 to -4.7 respectively. These data show that the crustal contribution is important, as confirmed by the Pb isotopes. The hybridisation processes seem to have occurred in the lower crust in magma chambers underlying the Matorello laccolith. The paleo-gravity markers in the Matorello help understand the architecture of the Sambuco nappe. Isoclinal folds with a vertical axial plane can be seen at the contact between dioritic and granodioritic facies. The antiform structure of which the Matorello is the heart is in fact a syncline. This places it in the inverse flanc of the large recumbent fold that constitutes the Sambuco nappe. The gneiss blocs found in the summital wildflysh cover of the Antigorio nappe have been linked to the Matorello pluton. This means that the front of the Sambuco nappe already overlapped the Antigorio basin when it closed. This implies that the Lebendun nappe can only overlap the Antigorio nappe in it's external position. Résumé grand public La chaîne alpine est la conséquence de la collision tertiaire entre deux masses continentales, l'Europe au nord et la péninsule apulienne africaine au sud, originellement séparées par l'océan mésozoïque téthysien. Cette collision a fermé un espace large de plusieurs centaines de km avec pour résultat l'écaillage de la croûte terrestre en unités tectoniques de dimensions variables, qui se sont empilées, imbriquées, éventuellement replissées en nappes de géométrie complexe. Cet amoncellement de 40 km d'épaisseur a vu sa température et sa pression lithostatique internes augmenter jusqu'à des valeurs de l'ordre de 680 °C et 6000 bars, induisant une recristallisation métamorphique des roches. L'un des objectifs de la géologie alpine est de reconstituer la géographie de la région aux temps mésozoïques de l'océan téthysien, en d'autres termes, de replacer chacune des unités tectoniques identifiées au sein de l'empilement alpin dans sa position originelle. Le défi est de taille et peut être comparé à celui de la reconstitution d'un vaste puzzle, dont certaines pièces seraient endommagées au niveau de leur contour ou leurs couleurs (métamorphisme), dissimulées par d'autres (enfouissement), voire tombées de la table de jeu (subduction, échappement latéral). Plusieurs approches ont été mises en oeuvre au cours du siècle écoulé. On citera en particulier la stratigraphie, la tectonique et le paléomagnétisme. Dans ce travail, nous avons essentiellement utilisé des techniques de datation isotopique absolue des roches (U/Pb sur zircon) qui, sur la base des connaissances acquises par l'ensemble des autres disciplines géologiques, nous ont permis de mieux contraindre ta paléogéographie mésozoïque du domaine «pennique inférieur » des Alpes centrales lépontines. Et au-delà? Nous savons tous que la disposition des continents à la surface de la Terre évolue constamment. Il est donc tentant d'essayer de remonter plus loin encore dans le temps et de reconstituer la physionomie de la marge sud européenne, tout au moins certains éléments de son histoire, au cours de l'ère paléozoïque. Les traces de ces événements très anciens sont naturellement ténues et dans ce contexte, les techniques de datation mentionnées ci-dessus deviennent les outils les plus performants. Ainsi, des datations u/Pb sur zircon nous ont permis de recenser plusieurs intrusions magmatiques, attribuées à quatre événements orogéniques anté-alpins. Des âges néoprotérozoïques (630-610 millions d'années ou Ma), cambrien inférieur (540-530 Ma), ordovicien inférieur (480-470 Ma) et carbonifère supérieur-permien inférieur (310-285 Ma) ont été obtenus dans le socle de la nappe de Sambuco. Des âges similaires à 300 Ma ont été obtenus dans la nappe voisine de la Maggia, qui permettent de relier ces deux unités. Aujourd'hui côte à côte, ces deux nappes devaient également se trouver proches l'une de l'autre il y a 300 Ma, lors de l'extension post-varisque. Les structures magmatiques spectaculaires préservées dans le pluton du Matorello (300 Ma) contraignent la géométrie actuelle de la nappe de Sambuco dans laquelle l'intrusion s'est mise en place. La forme originelle du pluton, aujourd'hui retourné et replissé plusieurs fois, s'avère être tabulaire, faite d'intrusions de faible épaisseur (1-300 m) s'étalant en forme de disque (30m à 2 km de diamètre). Les injections successives de magma se sont accumulées sous un toit dioritique précoce; elles sont issues, par le refais de fractures, d'une chambre magmatique plus profonde, périodiquement réalimentée par des magmas calco-alcalins d'origine mantellique contaminés parla croûte continentale profonde (εNd = -2.1 à -4.7). Des accumulations d'enclaves magmatiques arrondies et granoclassées dans des paléo-chenaux à fond érosif témoignent de conditions de mise en place hydrodynamiques à haute énergie. Ces enclaves sont emmenées de la chambre magmatique sous-jacente à la faveur d'épisodes de fracturation hydraulique liés à l'injection de magmas matelliques chauds dans des liquides différenciés riches en eau. Cette hypothèse est étayée par l'existence de filons composites. Une paléohorizontale a pu être déduite au sein du pluton, indiquant que cette partie de la nappe de Sambuco est verticalisée et isoclinalement replissée par la déformation alpine. Finalement, des blocs érodés du socle Sambuco ont été retrouvés dans le wildflysch sommital de la couverture sédimentaire mésozoïque de la nappe d'Antigorio sous-jacente. Ceci suggère que les blocs ont été fournis parle front de la nappe de Sambuco en train de chevaucher sur la nappe d'Antigorio au moment de la fermeture du bassin sédimentaire de cette dernière.
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BACKGROUND: Persons infected with human immunodeficiency virus (HIV) have increased rates of coronary artery disease (CAD). The relative contribution of genetic background, HIV-related factors, antiretroviral medications, and traditional risk factors to CAD has not been fully evaluated in the setting of HIV infection. METHODS: In the general population, 23 common single-nucleotide polymorphisms (SNPs) were shown to be associated with CAD through genome-wide association analysis. Using the Metabochip, we genotyped 1875 HIV-positive, white individuals enrolled in 24 HIV observational studies, including 571 participants with a first CAD event during the 9-year study period and 1304 controls matched on sex and cohort. RESULTS: A genetic risk score built from 23 CAD-associated SNPs contributed significantly to CAD (P = 2.9 × 10(-4)). In the final multivariable model, participants with an unfavorable genetic background (top genetic score quartile) had a CAD odds ratio (OR) of 1.47 (95% confidence interval [CI], 1.05-2.04). This effect was similar to hypertension (OR = 1.36; 95% CI, 1.06-1.73), hypercholesterolemia (OR = 1.51; 95% CI, 1.16-1.96), diabetes (OR = 1.66; 95% CI, 1.10-2.49), ≥ 1 year lopinavir exposure (OR = 1.36; 95% CI, 1.06-1.73), and current abacavir treatment (OR = 1.56; 95% CI, 1.17-2.07). The effect of the genetic risk score was additive to the effect of nongenetic CAD risk factors, and did not change after adjustment for family history of CAD. CONCLUSIONS: In the setting of HIV infection, the effect of an unfavorable genetic background was similar to traditional CAD risk factors and certain adverse antiretroviral exposures. Genetic testing may provide prognostic information complementary to family history of CAD.
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1. 1. Summaries 1.1. Preamble and extended abstract The present thesis dissertation addresses the question of antiviral immunity from the particular standpoint of the adaptive T cell-mediated immune response. The experimental work is presented in the form of three published articles (two experimental articles and one review article, see sections 4.1, 4.2 and 4.3 on pages 73, 81 and 91, respectively), describing advances both in our understanding of viral control by CD8 T lymphocytes, and in vaccine development against the Human Immunodeficiency Virus Type 1 (HIV-1). Because the articles focus on rather specialized areas of antiviral immunity, the article sections are preceded by a general introduction (section 3) on the immune system in general, and on four viruses that were addressed in the experimental work, namely HIV-1, Cytomegalovirus (CMV), Epstein Barr Virus (EBV) and Influenzavirus (Flu). This introduction section is aimed at providing a glimpse on viral molecular biology and immunity, to help the hypothetical non-expert reader proceeding into the experimental part. For this reason, each section is presented as individual entity and can be consulted separately. The four viruses described are of peculiar relevance to immunity because they induce an array of opposite host responses. Flu causes a self limiting disease after which the virus is eradicated. CMV and EBV cause pauci-symptomatic or asymptomatic diseases after which the viruses establish lifelong latency in the host cells, but are kept in check by immunity. Eventually, HIV-1 establishes both latency - by inserting its genome into the host cell chromosome - and proceeds in destroying the immune system in a poorly controlled fashion. Hence, understanding the fundamental differences between these kinds of viral host interactions might help develop new strategies to curb progressive diseases caused by viruses such as HIV-1. Publication #1: The first article (section 4.1, page 73) represents the main frame of my laboratory work. It analyses the ability of CD8 T lymphocytes recovered from viral-infected patients to secrete interferon γ (IFN-γ) alone or in conjunction with interleukin 2 (IL-2) when exposed in vitro to their cognate viral antigens. CD8 T cells are instrumental in controlling viral infection. They can identify infected cells by detecting viral antigens presented at the surface of the infected cells, and eliminate both the cell and its infecting virus by triggering apoptosis and/or lysis of the infected cell. Recognition of these antigens triggers the cognate CD8 cells to produce cytokines, including IFN-γ and IL-2, which in turn attract and activate other pro-inflammatory cells. IFN-γ triggers both intrinsic antiviral activity of the infected cells and distant activation of pro-inflammatory cells, which are important for the eradication of infection. IL-2 is essential for clonal expansion of the antigen (Ag)-specific CD8 T cell. Hence the existence of Ag-specific CD8 cells secreting both IFN-γand IL-2 should be beneficial for controlling infection. In this first work we determined the percentage of IFN-y/IL-2 double positive and single IFN-γsecreting CD8 T cells against antigens HIV-1, CMV, EBV and Flu in three groups of subjects: (i) HIV-1 infected patients progressing to disease (progressors), (ii) HIV-1-infected subjects not progressing to disease (long-term non progressors or LTNP), and (iii) HIV negative blood donors. The results disclosed a specific IFN-y/IL-2 double positive CD8 response in all subjects able to control infection. In other words, IFN-y/IL-2 double positive CD8 cells were present in virus-specific CD8 T cells against Flu, CMV and EBV as well against HIV-1 in LTNP. In contrast, progressors only had single IFN-γsecreting CD8 T cells. Hence, the ability to develop an IFN-y/IL-2 double positive response might be critical to control infection, independently of the nature of the virus. Additional experiments helped identify the developmental stage of the missing cells (using different markers such as CD45RA and CCR7) and showed a correlation between the absence of IL-2 secreting CD8 T cells and a failure in the proliferation capacity of virus-specific CD8 T cells. Addition of exogenous IL-2 could restore clonal expansion of HIV-1 specific CD8 T cells, at least in vitro. It could further been shown, that IL-2 secreting CD8 T cells are sufficient to support proliferation even in absence of CD4 help. However, the reason for the missing IFN-y/IL-2 double positive CD8 T cell response in HIV-1 progessors has yet to be determined. Publication #2: The second article (section 4.2, page 81) explores new strategies to trigger CD8 T cell immunity against specific HIV-1 proteins believed to be processed and exposed as "infection signal" at the surface of infected cells. Such signals consist of peptide fragments (8- 13 amino acids) originating from viral proteins and presented to CD8 T cells in the frame of particular cell surface molecules of the major histocompatibility complex class I* (MHC I). To mimic "natural" viral infection, the HIV-1 polyprotein Gagpolnef was inserted and expressed in either of two attenuated viruses i.e. vaccinia virus (MVA) or poxvirus (NYVAC). Mice were infected with these recombinant viruses and specific CD8 T cell response to Gagpolnef peptides was sought. Mice could indeed mount a CD8 T cell response against the HIV-1 antigens, indicating that the system worked, at least in this animal model. To further test whether peptides from Gagpolnef could also be presented in the frame of the human MHC class I proteins, a second round of experiments was performed in "humanized" transgenic mice expressing human MHC molecules. The transgenic mice were also able to load Gagpolnef peptides on their human MHC molecule, and these cells could be detected and destroyed by Ag-specific CD8 T cells isolated from HIV-1-infected patients. Therefore, expressing Gagpolnef on attenuated recombinant viruses might represent a valid strategy for anti-HIV-1 immunization in human. Publication #3: This is a review paper (section 4.3, page 91) describing the immune response to CMV and newly developed methods to detect this cellular immune response. Some of it focuses on the detection of T cells by using in vitro manufactured tetramers. These consist of four MHC class I molecules linked together and loaded with the appropriate antigenic peptide. The tetramer can be labeled with a fluorochrome and analyzed with a fluorescence-activated cell sorter. Taken together, the work presented indicates that (i) an appropriate CD8 T cell response consisting of IFN-y/IL-2 double positive effectors, can potentially control viral infection, including HIV-1 infection, (ii) such a response might be triggered by recombinant viral vaccines, and (iii) CD8 T cell response can be monitored by a variety of techniques, including recently-developed MHC class I tetramers. 1. 2. Préambule et résumé élargi Le présent travail de thèse s'intéresse à l'immunité antivirale du point de vue particulier de la réponse adaptative des cellules T. Le travail expérimental est présenté sous la forme de trois articles publiés (2 articles expérimentaux et 1 article de revue, voir sections 4.1, 4.2 et 4.3, pages 58, 66 et 77, respectivement), décrivant des progrès dans la compréhension du contrôle de l'infection virale par les lymphocytes T CD8, ainsi que dans le développement de nouveaux vaccins contre le Virus d'Immunodéficience de Humaine de type 1 (VIH-1). En raison du caractère spécialisé de l'immunité antivirale de type cellulaire, les articles sont précédés par une introduction générale (section 3), dont le but est de pourvoir le lecteur non avisé avec des bases nécessaire à une meilleure appréhension du travail expérimental. Cette introduction présente les grandes lignes du système immunitaire, et décrit de façon générale les 4 virus utilisés dans le travail expérimental: à savoir le virus VIH-1, le Cytomégalovirus (CMV), le virus Epstein Barr (EBV) et le virus Influenza A (Flu). Toutes les sections sont présentées de façon individuelle et peuvent être consultées séparément. La description des 4 virus a une pertinence particulière quant à leur interaction avec le système immun. En effet, ils induisent une panoplie de réponses immunitaires s'étendant aux extrêmes de la réaction de l'hôte. Influenza A est à l'origine d'une maladie cytopathique aiguë, au décours de laquelle le virus est éradiqué par l'hôte. CMV et EBV sont classiquement à l'origine d'infections pauci-symptomatiques, voire asymptomatiques, après lesquelles les virus persistent de façon latente dans la cellule hôte. Cependant, ils restent sous le contrôle du système immun, qui peut prévenir une éventuelle réactivation. Enfin, VIH-1 s'établit à la fois en infection latente - par l'insertion de son génome dans le chromosome des cellules hôtes - et en infection productive et cytopathique, échappant au contrôle immunitaire et détruisant ses cellules cibles. La compréhension des différences fondamentales entre ces différents types d'interactions virus-hôte devraient faciliter le développement de nouvelles stratégies antivirales. Article 1: Le premier article (section 4.1 Page 58) représente l'objet principal de mon travail de laboratoire. Il analyse la capacité des lymphocytes T CD8 spécifiques de différent virus à sécréter de l'interféron gamma (IFN-y) et/ou de l'interleukine 2 (IL-2) après stimulation par leur antigène spécifique. Les cellules T CD8 jouent un rôle crucial dans le contrôle des infections virales. Elles identifient les cellules infectées en détectant des antigènes viraux présentés à la surface de ces mêmes cellules, et éliminent à la fois les cellules infectées et les virus qu'elles contiennent en induisant l'apoptose et/ou la lyse des cellules cibles. Parallèlement, l'identification de l'antigène par la cellule T CD8 la stimule à sécréter des cytokines. L'IFN-γen est un exemple. L'IFN-γ stimule les cellules infectées à développer une activé antivirale intrinsèque. De plus, il attire sur place d'autres cellules de l'inflammation, et active leur fonction d'éradication des pathogènes. L'IL-2 est un autre exemple. L'IL-2 est essentielle à l'expansion clonale des cellules T CD8 spécifiques à un virus donné. Elle est donc essentielle à augmenter le pool de lymphocytes antiviraux. En conséquence, la double capacité de sécréter de l'IFN-γ et de IL-2 pourrait être un avantage pour le contrôle antiviral par les cellules T CD8. Dans ce travail nous avons comparé les proportions de lymphocytes T CD8 doubles positifs (IFN-γ/IL-2) et simples positifs (IFN-γ) chez trois groupes de sujets: (i) des patients infectés par VIH-1 qui ne contrôlent pas l'infection (progresseurs), (ii) des patients infectés par VIH-1, mais contrôlant l'infection malgré l'absence de traitement ("long term non progressors" [LTNP]) et (iii) des donneurs de sang négatifs pour l'infection à VIH-1. Les résultats ont montré que les individus capables de contrôler une infection possédaient des cellules T CD8 doubles positifs (IFN-γ/IL-2), alors que les patients ne contrôlant pas l'infection procédaient prioritairement des CD8 simples positifs (IFN-γ). Spécifiquement, les lymphocytes T spécifiques pour Flu, CMV, EBV, et VII-1-1 chez les LTNP étaient tous IFN-γ/IL-2 doubles positifs. Au contraire, les lymphocytes T CD8 spécifique à VIH-1 étaient IFN-γ simples positifs chez les progresseurs. La capacité de développer une réponse IFN-γ/IL-2 pourraient être primordiale pour le contrôle de l'infection, indépendamment de la nature du virus. En effet, il a été montré que l'absence de sécrétion d'IL2 par les lymphocytes T CD8 corrélait avec leur incapacité de proliférer. Dans nos mains, cette prolifération a pu être restaurée in vitro par l'adjonction exogène d'IL-2. Toutefois, la faisabilité de ce type de complémentation in vivo n'est pas claire. Des expériences additionnelles ont permis de préciser de stade de développement des lymphocytes doubles positifs et simples positifs par le biais des marqueurs CD45RA et CCR7. Il reste maintenant à comprendre pourquoi certains lymphocytes T CD8 spécifiques sont incapables à sécréter de l'IL-2. Article 2: Le deuxième article explore des nouvelles stratégies pour induire une immunité T CD8 spécifique aux protéines du VIH-1, qui sont édités et exposés à la surface des cellules infectées. Ces signaux consistent en fragments de peptide de 8-13 acide aminés provenant de protéines virales, et exposées à la surface des cellules infectées dans le cadre des molécules spécialisées d'histocompatibilité de classe I (en anglais "major histocompatibility class I" ou MHC I). Pour mimer une infection virale, la polyprotéine Gagpolnef du VIH-1 a été insérée et exprimée dans deux vecteurs viraux atténués, soit MVA (provenant de vaccinia virus) ou NYVAC (provenant d'un poxvirus). Ensuite des souris ont été infectées avec ces virus recombinants et la réponse T CD8 aux peptides issus de Gagpolnef a été étudiée. Les souris ont été capables de développer une réponse de type CD8 T contre ces antigènes du VIH-1. Pour tester si ces antigènes pouvaient aussi être présentés par dans le cadre de molécules MHC humaines, des expériences supplémentaires ont été faites avec des souris exprimant un MHC humain. Les résultats de ces manipulations ont montré que des cellules T CD8 spécifique aux protéines du VIH pouvaient être détectées. Ce travail ouvre de nouvelles options quant à l'utilisation des virus recombinants exprimant Gagpolnef comme stratégie vaccinale contre le virus VIH-I chez l'homme. Article 3: Ces revues décrivent la réponse immunitaire à CMV ainsi que des nouvelles méthodes pouvant servir à sa détection. Une partie du manuscrit décrit la détection de cellule T à l'aide de tétramères. Il s'agit de protéines chimériques composées de 4 quatre molécules MHC liées entre elles. Elles sont ensuite "chargées" avec le peptide antigénique approprié, et utilisée pour détecter les cellules T CD8 spécifiques à ce montage. Elles sont aussi marquées par un fluorochrome, qui permet une analyse avec un cytomètre de flux, et l'isolement ultime des CD8 d'intérêt. En résumé, le travail présenté dans cette thèse indique que (i) une réponse T CD8 appropriée - définie par la présence des cellules effectrices doublement positives pour l'IFN-γ et l'IL-2 - semble indispensable pour le contrôle des infections virales, y compris par le VIH-1, (ii) une telle réponse peut être induite par des vaccin viral recombinant, et (iii) la réponse T CD8 peut être analysée et suivie grâce à plusieurs techniques, incluant celle des tétramères de MHC class I. 1.3. Résumé pour un large public Le système immunitaire humain est composé de différents éléments (cellules, tissus et organes) qui participent aux défenses de l'organisme contre les pathogènes (bactéries, virus). Parmi ces cellules, les lymphocytes T CD8, également appelés cellules tueuses, jouent un rôle important dans la réponse immunitaire et le contrôle des infections virales. Les cellules T CD8 reconnaissent de manière spécifique des fragments de protéines virales qui sont exposés à la surface des cellules infectées par le virus. Suite à cette reconnaissance, les cellules T CD8 sont capables de détruire et d'éliminer ces cellules infectées, ainsi que les virus qu'elles contiennent. Dans le contexte d'une infection par le virus de l'immunodéficience humaine (VIH), le virus responsable du SIDA, il a pu être montré que la présence des cellules T CD8 est primordiale. En effet, en l'absence de ces cellules, les individus infectés par le VIH progressent plus rapidement vers le SIDA. Au cours de la vie, l'Homme est exposé à plusieurs virus. Mais à l'opposé du VIH, certains d'entre eux ne causent pas des maladies graves : par exemple le virus de la grippe (Influenza), le cytomégalovirus ou encore le virus d'Epstein-Barr. Certains de ces virus peuvent être contrôlés et éliminés de l'organisme (p. ex. le virus de la grippe), alors que d'autres ne sont que contrôlés par notre système immunitaire et restent présents en petite quantité dans le corps sans avoir d'effet sur notre santé. Le sujet de mon travail de thèse porte sur la compréhension du mécanisme de contrôle des infections virales par le système immunitaire : pourquoi certains virus peuvent être contrôlés ou même éliminés de l'organisme alors que d'autres, et notamment le VIH, ne le sont pas. Ce travail a permis de démontrer que les cellules T CD8 spécifiques du VIH ne sécrètent pas les mêmes substances, nécessaires au développement d'une réponse antivirale efficace, que les cellules T CD8 spécifiques des virus contrôlés (le virus de la grippe, le cytomégalovirus et le virus d'Epstein-Barr). Parallèlement nous avons également observé que les lymphocytes T CD8 spécifiques du VIH ne possèdent pas la capacité de se diviser. Ils sont ainsi incapables d'être présents en quantité suffisante pour assurer un combat efficace contre le virus du SIDA. La (les) différence(s) entre les cellules T CD8 spécifiques aux virus contrôlés (grippe, cytomégalovirus et Epstein-Barr) et au VIH pourront peut-être nous amener à comprendre comment restaurer une immunité efficace contre ce dernier.
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Background: Experimental evidences demonstrate that vegetable derived extracts inhibit cholesterol absorption in the gastrointestinal tract. To further explore the mechanisms behind, we modeled duodenal contents with several vegetable extracts. Results: By employing a widely used cholesterol quantification method based on a cholesterol oxidase-peroxidase coupled reaction we analyzed the effects on cholesterol partition. Evidenced interferences were analyzed by studying specific and unspecific inhibitors of cholesterol oxidase-peroxidase coupled reaction. Cholesterol was also quantified by LC/MS. We found a significant interference of diverse (cocoa and tea-derived) extracts over this method. The interference was strongly dependent on model matrix: while as in phosphate buffered saline, the development of unspecific fluorescence was inhibitable by catalase (but not by heat denaturation), suggesting vegetable extract derived H2O2 production, in bile-containing model systems, this interference also comprised cholesterol-oxidase inhibition. Several strategies, such as cholesterol standard addition and use of suitable blanks containing vegetable extracts were tested. When those failed, the use of a mass-spectrometry based chromatographic assay allowed quantification of cholesterol in models of duodenal contents in the presence of vegetable extracts. Conclusions: We propose that the use of cholesterol-oxidase and/or peroxidase based systems for cholesterol analyses in foodstuffs should be accurately monitored, as important interferences in all the components of the enzymatic chain were evident. The use of adequate controls, standard addition and finally, chromatographic analyses solve these issues.
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Background: Gender-related differences are seen in multiple aspects of both health and illness. Ischemic heart disease (IHD) is a pathology in which diagnostic, treatment and prognostic differences are seen between sexes, especially in the acute phase and in the hospital setting. The objective of the present study is to analyze whether there are differences between men and women when examining associated cardiovascular risk factors and secondary pharmacological prevention in the primary care setting. Methods: Retrospective descriptive observational study from January to December of 2006, including 1907 patients diagnosed with ischemic heart disease in the city of Lleida, Spain. The clinical data were obtained from computerized medical records and pharmaceutical records of medications dispensed in pharmacies with official prescriptions. Data was analyzed using bivariate descriptive statistical analysis as well as logistic regression. Results: There were no gender-related differences in screening percentages for arterial hypertension, diabetes, obesity, dyslipemia, and smoking. A greater percentage of women were hypertensive, obese and diabetic compared to men. However, men showed a tendency to achieve control targets more easily than women, with no statistically significant differences. In both sexes cardiovascular risk factors control was inadequate, between 10 and 50%. For secondary pharmaceutical prevention, the percentages of prescriptions were greater in men for anticoagulants, beta-blockers, lipid-lowering agents and angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers, with age group variations up to 10%. When adjusting by age and specific diagnoses, differences were maintained for anticoagulants and lipid-lowering agents. Conclusion: Screening of cardiovascular risk factors was similar in men and women with IHD. Although a greater percentage of women were hypertensive, diabetic or obese, their management of risk factors tended to be worse than men. Overall, a poor control of cardiovascular risk factors was noted. Taken as a whole, more men were prescribed secondary prevention drugs, with differences varying by age group and IHD diagnosis.
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BACKGROUND: Pneumonia is the biggest cause of deaths in young children in developing countries, but early diagnosis and intervention can effectively reduce mortality. We aimed to assess the diagnostic value of clinical signs and symptoms to identify radiological pneumonia in children younger than 5 years and to review the accuracy of WHO criteria for diagnosis of clinical pneumonia. METHODS: We searched Medline (PubMed), Embase (Ovid), the Cochrane Database of Systematic Reviews, and reference lists of relevant studies, without date restrictions, to identify articles assessing clinical predictors of radiological pneumonia in children. Selection was based on: design (diagnostic accuracy studies), target disease (pneumonia), participants (children aged <5 years), setting (ambulatory or hospital care), index test (clinical features), and reference standard (chest radiography). Quality assessment was based on the 2011 Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. For each index test, we calculated sensitivity and specificity and, when the tests were assessed in four or more studies, calculated pooled estimates with use of bivariate model and hierarchical summary receiver operation characteristics plots for meta-analysis. FINDINGS: We included 18 articles in our analysis. WHO-approved signs age-related fast breathing (six studies; pooled sensitivity 0·62, 95% CI 0·26-0·89; specificity 0·59, 0·29-0·84) and lower chest wall indrawing (four studies; 0·48, 0·16-0·82; 0·72, 0·47-0·89) showed poor diagnostic performance in the meta-analysis. Features with the highest pooled positive likelihood ratios were respiratory rate higher than 50 breaths per min (1·90, 1·45-2·48), grunting (1·78, 1·10-2·88), chest indrawing (1·76, 0·86-3·58), and nasal flaring (1·75, 1·20-2·56). Features with the lowest pooled negative likelihood ratio were cough (0·30, 0·09-0·96), history of fever (0·53, 0·41-0·69), and respiratory rate higher than 40 breaths per min (0·43, 0·23-0·83). INTERPRETATION: Not one clinical feature was sufficient to diagnose pneumonia definitively. Combination of clinical features in a decision tree might improve diagnostic performance, but the addition of new point-of-care tests for diagnosis of bacterial pneumonia would help to attain an acceptable level of accuracy. FUNDING: Swiss National Science Foundation.
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BACKGROUND: In 2011, a patient was admitted to our hospital with acute schistosomiasis after having returned from Madagascar and having bathed at the Lily waterfalls. On the basis of this patient's indication, infection was suspected in 41 other subjects. This study investigated (1) the knowledge of the travelers about the risks of schistosomiasis and their related behavior to evaluate the appropriateness of prevention messages and (2) the diagnostic workup of symptomatic travelers by general practitioners to evaluate medical care of travelers with a history of freshwater exposure in tropical areas. METHODS: A questionnaire was sent to the 42 travelers with potential exposure to schistosomiasis. It focused on pre-travel knowledge of the disease, bathing conditions, clinical presentation, first suspected diagnosis, and treatment. RESULTS: Of the 42 questionnaires, 40 (95%) were returned, among which 37 travelers (92%) reported an exposure to freshwater, and 18 (45%) were aware of the risk of schistosomiasis. Among these latter subjects, 16 (89%) still reported an exposure to freshwater. Serology was positive in 28 (78%) of 36 exposed subjects at least 3 months after exposure. Of the 28 infected travelers, 23 (82%) exhibited symptoms and 16 (70%) consulted their general practitioner before the information about the outbreak had spread, but none of these patients had a serology for schistosomiasis done during the first consultation. CONCLUSIONS: The usual prevention message of avoiding freshwater contact when traveling in tropical regions had no impact on the behavior of these travelers, who still went swimming at the Lily waterfalls. This prevention message should, therefore, be either modified or abandoned. The clinical presentation of acute schistosomiasis is often misleading. General practitioners should at least request an eosinophil count, when confronted with a returning traveler with fever. If eosinophilia is detected, it should prompt the search for a parasitic disease.
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Severe acute refractory respiratory failure is considered a life-threatening situation, with a high mortality of 40 to 60%. When conservative oxygenation methods fail, a lifesaving measure is the introduction of extracorporeal membrane oxygenation (ECMO). Venovenous ECMO (VV-ECMO) is a preferred modality of support for patients with refractory acute respiratory failure. Specifically, bicaval VV-ECMO is a well-recognized and validated therapy, where single or double periphery venous access is used for the insertion of two differently sized cannulas in order to achieve adequate blood oxygenation. Compared to venoarterial ECMO, in VV-ECMO, the rate of complications, such as thrombosis, bleeding, infection and ischemic events, is lower. On the other hand, the size and insertion location is an obstacle to patient mobilization. This is a considerable problem for patients where the time interval for lung recovery and the bridge to the transplantation is prolonged. To address this issue, a dual-lumen, single venovenous cannula was introduced. Here, by insertion of one single catheter in one target vessel, in a majority of cases in the right internal jugular vein, satisfactory oxygenation of the patient is achieved. In this form, the instituted VV-ECMO enables patient mobility, better physical rehabilitation and facilitates pulmonary extubation and toilet. However, relatively early, after the first short-term reports were published, a relatively high complication rate became evident. In the recent literature, the complication rate using actual commercially available double-lumen venovenous cannula ranges between 5 and 30%. These cases were mostly conjoined to the implantation phase or the early postoperative phase and vary between right heart perforation to migration of the cannula. This review focuses on complications allied to commercially available dual-lumen, single, venovenous cannula implantation, pointing out the critical segments of the implantation process and analyzing the structure of the device.
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PURPOSE: The natural history of prostate cancer might be driven by the index lesion. We determined the percent of men in whom the index lesion could be defined using transperineal template prostate mapping biopsies. MATERIALS AND METHODS: Included in study were consecutive men undergoing transperineal template prostate mapping biopsies with biopsies grouped into 20 zones. Men with clinically significant disease in only 1 prostate area were considered to have an identifiable index lesion. We evaluated the impact of using 2 definitions of clinically significant disease (Gleason grade pattern 4 and/or lesion volume 0.5 cc or greater) and 2 clustering rules (stringent and tolerant) to define the index lesion. RESULTS: Included in study were 391 men with a median age of 62 years (IQR 58-67) and a median prostate specific antigen of 6.9 ng/ml (IQR 4.8-10.0). Of the men 269 (69%) were previously diagnosed with prostate cancer. By deploying a median of 1.2 cores per ml (IQR 0.9-1.7) cancer was diagnosed in 82.9% of the men (324 of 391) with a median of 6 positive cores (IQR 2-9), a median maximum cancer core length of 5 mm (IQR 3-8) and a total cancer core length per zone of 7 mm (IQR 3-13). Insignificant disease was found in 26.3% to 42.9% of cases. When a stringent spatial relationship was used to define individual lesions, 44.4% to 54.6% of patients had 1 index lesion and 12.7% to 19.1% had more than 1 area with clinically significant disease. These proportions changed to 46.6% to 59.2% and 10.5% to 14.5%, respectively, when less stringent spatial clustering was applied. CONCLUSIONS: Transperineal template prostate mapping biopsies enable the index lesion to be localized in most men with clinically significant disease. This information may be important to select appropriate candidates for targeted therapy and to plan a tailored treatment strategy in men undergoing radical therapy.