999 resultados para EXOGENOUS HEMOSTATIC FACTORS
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Social Accounting Matrices (SAM) are normally used to analyse the income generation process. They are also useful, however, for analysing the cost transmission and price formation mechanisms. For price contributions, Roland-Holst and Sancho (1995) used the SAM structure to analyse the price and cost linkages through a representation of the interdependence between activities, households and factors. This paper is a further analysis of the cost transmission mechanisms, in which I add the capital account to the endogenous components of the Roland-Holst and Sancho approach. By doing this I reflect the responses of prices to the exogenous shocks in savings and investment. I also present an additive decomposition of the global price effects into categories of interdependence that isolates the impact on price levels of shocks in the capital account. I use a 1994 Social Accounting Matrix to make an empirical application of the Catalan economy. Keywords: social accounting matrix, cost linkages, price transmission, capital account. JEL Classification: C63, C69, D59.
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The main motivation for exploring the relationship between globalization and Europeanization is the understanding of the importance of exogenous factors for policy change at the domestic level. Can we distinguish the impact of Europeanization to that of globalization? What is the relationship between globalization and Europeanization and what can we learn about the impact of the two phenomena upon political institutions, public policies, identities and values of EU member-states? Can we distinguish the traces of globalization to those of Europeanization upon the domestic level? The paper draws upon International Relations and International Political Economy theories of globalization as well as upon the Europeanization literature. Both phenomena are multi-dimensional and in order to assess their impact and their relationship three dimensions are explored: political institutions, public policies and values and identities. It is concluded that the two phenomena are interwoven and that there is no antithetical relationship between them. Their core is similar, based on the values of neo-liberalism, representative democracy and open market economy.
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Studies were undertaken to determine the influence of several host-related parameters on the course of Leishmania mexicana mexicana infection in inbred C57B1/10 (C57) and outbred albino (OA) mice. An important influence of the following variables was demonstrated: Host strain: lesions in C57s were significantly less variable in size and outcome than those of OAs under the conditions studied and even when persistent developed at a slower rate. Host age: Subcutanous injection of 2 x 10 [raised to the power of 4] to 2 x 10 [raised to the power of 6] amastigotes into the dorsum of the rear paw produced significantly larger lesions which healed more slowly in 2 mo. old C57s than in 4 mo. old mice. Reduced healing ability was observed in older (8 mo. old) female C57s, and low mortality occurred after 15 months of age in infected mice of both sexes. Lesion site: Following amastigote infection, lesions in paws of most C57s regress within 15 - 25 wks. In contrast, perinasal legions produced with the same number of parasites tend to persist for the life of the animal as slowly spreading irregular nodules. In animals infected in both locations, each lesion site behaves similarly to that in singly infected animals of the same age, i.e. regression in the two sites is independent. Our results indicate that while host strain may strongly influence infection outcoem, such variables as lesion site and host age play important roles and may explain, in part, reported inter- and intraexperimental variability in responses of murine hosts to a given leishmanial parasite.
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Aedes fluviatilis is susceptible to infection by Plasmodium gallinaceum and is a convenient insect host for the malaria parasite in countries where Aedees aegypti cannot be maintained in laboratories. In South America, for instance, the rearing of A. aegypti the main vector of urban yellow fever, is not advaisable because of the potential health hazard it represents. Our results of the comparative studies carried out between the sporogonic cycle produced with two lines of P. gallinaceum parasites into A. fuviatilis were as follows. As proved for A. aegypti, mosquito infection rates were variable when A. fluviatilis blood-fed on chicks infected with and old syringe-passaged strain of P. gallinaceum. Oocysts developed in 41% of those mosquitos and the mean peak of oocyst production was 56 per stomach. Salivary gland infections developed in about 6% of the mosquitos. The course of sporogony was unrelated to the size of the inoculum administered to chicks or to the route by which the birds were infected. The development of infected salivary glands was unrelated to oocyst production. Sporogony of P. gallinaceum was more uniform when mosquitos blood-fed on chicks infected with a sporozoite-passaged strain. Oocysts developed in about 50% of those mosquitoes and the mean peak of oocyst production was 138 per stomach, with some individuals having as many as 600-800 oocysts. Infected salivary glands developed in a mean of 27% of the mosquitos but, in some batches, was a high as 50%. Patterns of salivary gland parasitism were similar to those of oocyst production. The course of sporogony of P. gallinaceum in A. fluviatilis is analized in relation to degree of parasitemia and gametocytemia in the vertebrate host.
Impact of preoperative risk factors on morbidity after esophagectomy: is there room for improvement?
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BACKGROUND: Despite progress in multidisciplinary treatment of esophageal cancer, oncologic esophagectomy is still the cornerstone of therapeutic strategies. Several scoring systems are used to predict postoperative morbidity, but in most cases they identify nonmodifiable parameters. The aim of this study was to identify potentially modifiable risk factors associated with complications after oncologic esophagectomy. METHODS: All consecutive patients with complete data sets undergoing oncologic esophagectomy in our department during 2001-2011 were included in this study. As potentially modifiable risk factors we assessed nutritional status depicted by body mass index (BMI) and preoperative serum albumin levels, excessive alcohol consumption, and active smoking. Postoperative complications were graded according to a validated 5-grade system. Univariate and multivariate analyses were used to identify preoperative risk factors associated with the occurrence and severity of complications. RESULTS: Our series included 93 patients. Overall morbidity rate was 81 % (n = 75), with 56 % (n = 52) minor complications and 18 % (n = 17) major complications. Active smoking and excessive alcohol consumption were associated with the occurrence of severe complications, whereas BMI and low preoperative albumin levels were not. The simultaneous presence of two or more of these risk factors significantly increased the risk of postoperative complications. CONCLUSIONS: A combination of malnutrition, active smoking and alcohol consumption were found to have a negative impact on postoperative morbidity rates. Therefore, preoperative smoking and alcohol cessation counseling and monitoring and improving the nutritional status are strongly recommended.
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Les virus exploitent la machinerie cellulaire de l'hôte pour se répliquer. Ils doivent s'adapter pour infecter la cellule hôte de manière optimale tout en échappant à la vigilance du système de défense de l'hôte. Ainsi l'hôte et les virus se livrent à de constantes batailles évolutives. Mon travail de thèse a porté sur l'étude des signatures évolutives de facteurs de l'hôte agissant comme des 'facteurs de restriction' en bloquant la réplication rétrovirale chez les primates. Plus spécifiquement, mon travail a visé à utiliser des données évolutives pour renseigner les analyses fonctionnelles et la biologie. Nous avons étudié le facteur anti-VIH-1 nommé TRIM5a (i) chez les prosimiens pour mieux comprendre son rôle dans le contrôle d'un lentivirus endogène, (ii) dans son activité contre d'autres anciennes infections représentées par des rétrovirus endogènes humains et (iii) en tant que protéine capable de générer des mutants de la capside. Premièrement nous nous sommes intéressés à TRIM5a chez deux espèces de lémuriens dont Microcebus murinus qui porte le lentivirus endogène PSIV dans son génome depuis plusieurs millions d'années,. Nous avons observé que TRIM5a chez M. murinus a un spectre d'activité antivirale réduit à l'opposé de TRIM5a chez le Lemur catta - non porteur du PSIV endogène - qui bloque une large variété de rétrovirus dont le PSIV. De ce fait TRIM5a aurait pu contribuer à protéger certaines espèces de lémuriens vis-à-vis d'anciennes infections par le PSIV. A l'inverse du PSIV, des virus dérivés des rétrovirus endogènes humains HERV-K and HERV-H se sont révélés largement résistants à l'inhibition par TRIM5a. Ces données illustrent une absence de protection par TRIM5a face à d'autres anciennes infections rétrovirales. Puis, pour évaluer l'impact de la protéine TRIM5a humaine sur le VIH-1, nous avons testé l'effet de mutations des résidues sous sélection positive dans la capside du VIH-1 sur l'inhibition par TRIM5a. Nos résultats montrent que TRIM5a ne jouerait pas un rôle significatif dans l'évolution de la capside du VIH-1. Enfin notre travail a porté sur le facteur anti-VIH-1 SAMHD1 récemment découvert, que nous avons séquencé chez 25 espèces de primates. L'analyse évolutive des sites sous sélection positive et des expériences fonctionnelles ont permis d'identifier le domaine de SAMHD1 interagissant avec la protéine lentivirale Vpx. De même que d'autres protéines virales contrecarrent les facteurs de restriction en les menant à la dégradation, nous avons observé que Vpx induit la dégradation de SAMHD1 de manière spécifique à l'espèce. Ces découvertes contribuent à comprendre comment les facteurs de restriction et les virus co-évoluent pour se neutraliser l'un l'autre. - Viruses hijack the host cellular machinery to replicate. They adapt to infect optimally host cells while escaping host defense systems. Viruses and the host coevolve in an evolutionary struggle. My thesis work has been devoted to study the evolutionary signatures of host factors acting as restriction factors that block retroviral replication in primates. Specifically, my work aimed at using evolutionary data to inform functional analyses and biology. We studied the anti-HIV-1 factor TRIM5a (i) in prosimians to better understand its possible role in the control of an endogenous lentivirus, (ii) in its activity against other ancient infections - as represented by HERVs, and (iii) as a protein capable of generating escape mutants in the viral capsid. First, my work focused on two lemur species, one of which was the gray mouse lemur that carries the endogenous lentivirus PSIV integrated in its genome for several million years. TRIM5a from gray mouse lemur exhibited a limited antiviral spectrum as opposed to TRIM5a from ring-tailed lemur - not a host of PSIV - that is able to block diverse retroviruses notably PSIV. These results support the possible contribution of TRIM5a in protecting lemur species from ancient infection by PSIV. In contrast, chimeric viruses derived from two human endogenous retroviruses were broadly resistant to TRIM5a-mediated restriction, suggesting TRIM5a lack of activity against other types of ancient infections. To evaluate the recent impact of human TRIM5a on HIV-1 evolution, we tested whether variants at positively selected sites in the HIV-1 capsid affected the ability of human TRIM5a alleles to restrict HIV-1. Our results indicate that TRIM5a does not play a significant role in the evolution of HIV1 capsid. At last, our work concentrated on the newly discovered anti-HIV-1 restriction factor SAMHD1. We determined its coding sequence in a panel of 25 species of primates. Evolutionary analyses of positively selected sites in SAMHD1 domains and functional assays identified the domain of SAMHD1 interacting with the lentiviral protein Vpx. Similar to other viral countermeasures targeting cellular restriction factors, Vpx was responsible of the degradation of SAMHD1 orthologs in a species-specific manner. These findings contributed to understanding how restriction factors and viruses evolve to counteract each other.
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Summary : The hypothalamus represents less than 1 % of the total volume of the brain tissue, yet it plays a crucial role in endocrine regulations. Puberty is defined as a process leading to physical, sexual and psychosocial maturation. The hypothalamus is central to this process, via the activation of GnRH neurons. Pulsatile GnRH secretion, minimal during childhood, increases with the onset of puberty. The primary function of GnRH is to regulate the growth, development and function of testes in boys and ovaries in girls, by stimulating the pituitary gland secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Several factors contribute to the timing of puberty, including sex and ethnicity, genetics, dietary intake and energy expenditure. Kisspeptins constitute a family of small peptides arising from the proteolytic cleavage of metastin, a peptide with 54 amino acids initially purified from human placenta. These kisspeptins were the subject of much attention following their discovery because of their antimetastatic properties, but it was more recently that their determining role in the reproductive function was demonstrated. It was shown that kisspeptins are ligands of a receptor, GPR54, whose natural inactivating mutation in humans, or knockout in the mouse, lead to infertility. GnRH neurons play a pivotal role in the central regulation of fertility. Kisspeptin greatly increases GnRH release and GnRH neuron firing activity, but the neurobiological mechanisms for these actions are unknown. Gprotein-coupled receptor 54, the receptor for kisspeptin, is expressed by GnRH neurons as well as other hypothalamic neurons, suggesting that both direct and indirect effects are possible. In the first part of my thesis, we investigated a possible connection between the acceleration of sexual development induced by leptin and hypothalamic metastin neurons. However, the data generated by our preliminary experiments confirmed that the commercially available antibodies are non-specific. This finding constituted a major drawback for our studies, which relied heavily upon the neuroanatomical study of the hypothalamic metastinergic pathways to elucidate their sensitivity to exogenous leptin. Therefore, we decided to postpone any further in vivo experiment until a better antibody becomes available, and focused on in vitro studies to better understand the mechanisms of action of kisspeptins in the modulation of the activity of GnRH neurons. We used two GnRH-expressing neuronal cell lines to investigate the cellular and molecular mechanisms of action of metastin in GnRH neurons. We demonstrated that kisspeptin induces an early activation of the MAP kinase intracellular signaling pathway in both cell lines, whereas the SAP/JNK or the Akt pathways were unaffected. Moreover, we found an increase in GnRH mRNA levels after 6h of metastin stimulation. Thus, we can conclude that kisspeptin regulates GnRH neurons both at the secretion and the gene expression levels. The MAPK pathway is the major pathway activated by metastin in GnRH expressing neurons. Taken together, these data provide the first mechanism of action of kisspeptin on GnRH neurons. Résumé : L'hypothalamus est une zone située au centre du cerveau, dont il représente moins de 1 du volume total. La puberté est la période de transition entre l'enfance et l'age adulte, qui s'accompagne de transformations somatiques, psychologiques, métaboliques et hormonales conduisant à la possibilité de procréer. La fonction principale de la GnRH est la régulation de la croissance, du développement et de la fonction des testicules chez les hommes, et des ovaires chez les femmes en stimulant la sécrétion de l'hormone lutéinisante (LH) et de l'hormone folliculostimulante (FSH) par la glande hypophysaire. Plusieurs facteurs contribuent au déclanchement de la puberté, y compris le sexe et l'appartenance ethnique, la génétique, l'apport alimentaire et la dépense énergétique. Les Kisspeptines constituent une famille de peptides résultant de la dissociation proteolytique de la métastine, un peptide de 54 acides aminés initialement purifié à partir de placenta humain. Ces kisspeptines ont fait l'objet de beaucoup d'attention à la suite de leur découverte en raison de leurs propriétés anti-metastatiques, et c'est plus récemment que leur rôle déterminant dans la fonction reproductive a été démontré. Les kisspeptines sont des ligands du récepteur GPR54, dont la mutation inactivatrice chez l'homme, ou le knockout chez la souris, conduisent à l'infertilité par hypogonadisme hypogonadotrope. Les neurones à GnRH jouent un rôle central dans le règlement des fonctions reproductrices et la kisspeptine stimule l'activité des neurones à GnRH et la libération de GnRH par ces neurones. Toutefois, les mécanismes neurobiologiques de ces actions ne sont pas connus. Dans la première partie de ma thèse, nous avons étudié le lien potentiel entre l'accélération du développement sexuel induite par la leptine et les neurones hypothalamiques à metastine. Les données générées dans cette première série d'expériences ont malheureusement confirmé que les anticorps anti-metastine disponibles dans le commerce sont aspécifiques. Ceci a constitué un inconvénient majeur pour nos études, qui devaient fortement s'appuyer sur l' étude neuroanatomique des neurones hypothalamiques à metastine pour évaluer leur sensibilité à la leptine exogène. Nous avons donc décidé de focaliser nos travaux sur une étude in vitro des mécanismes d'action de la kisspeptine pour moduler l'activité des neurones à GnRH. Nous avons utilisé deux lignées de cellules neuronales exprimant la GnRH pour étudier les mécanismes d'action cellulaires et moléculaires de la metastine dans des neurones. Nous avons ainsi pu démontrer que la kisspeptine induit une activation précoce de la voie f de signalisation de la MAP kinase dans les deux lignées cellulaires, alors que nous n'avons observé aucune activation de la voie de signalisation de la P13 Kinase et de la SAP/JNK. Nous avons en outre démontré une augmentation de l'expression de la GnRH par la stimulation avec la Kisspeptine. L'ensemble de ces données contribue à élucider le mécanisme d'action avec lequel la kisspeptine agit dans les neurones à GnRH, en démontrant un effet sur l'expression génique de la GnRH. Nous pouvons également conclure que la voie de la MAPK est la voie principale activée par la metastine dans les neurones exprimant la GnRH.
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Projecte de recerca elaborat a partir d’una estada al Pain Management Unit de la University of Bath-Royal National Hospital for Rheumatic Disease, a Gran Bretanya, entre juliol i octubre del 2006. El dolor i la discapacitat que hi va associada són experiències comunes. Les relacions entre variables de tipus biològic, social i psicològic han estat rarament investigades en mostres de nens que informen de dolor però extrets de contextos no clínics. L’objectiu d'aquest estudi va ser identificar els predictors de funcionament ens nens escolaritzats, que informaven que el dolor era una experiència força freqüent. Mig miler de nens d'entre 8 i 16 anys i els seus pares van participar en aquest estudi de disseny transversal. Informació de tipus biològic, social i psicològic era recollida a través d'entrevistes individualitzades amb els nens i la complementació de qüestionaris auto-informats per pares. El nivell funcionament del nen va ser avaluat a partir de 4 indicadors: auto-informes de qualitat de vida, assistència a l'escola, implicació en activitats físiques i/o esportives fòra de l'escola, i implicació en activitats de tipus sedentari. Es van recollir diversos tipus de variables psicològiques referents a l’afrontament del nen davant del dolor i tipus d'atenció dels pares a les conductes de dolor dels seu fill. Els resultats mostren un patró variable en funció de la mesura de funcionament específica utilitzada. Més específicament, s'ha proposat que la resposta de por a les experiències de dolor diàries pot ser un important predictor de funcionament. Són necessaris més estudis sobre la relació entre dolor i nivell d'implicació en conductes actives o sedentàries en nens.
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While genetic polymorphisms play a paramount role in tuberculosis (TB), less is known about their contribution to the severity of diseases caused by other intracellular bacteria and fastidious microorganisms. We searched electronic databases for observational studies reporting on host factors and genetic predisposition to infections caused by intracellular fastidious bacteria published up to 30 May 2014. The contribution of genetic polymorphisms was documented for TB. This includes genetic defects in the mononuclear phagocyte/T helper cell type 1 (Th1) pathway contributing to disseminated TB disease in children and genome-wide linkage analysis (GWAS) in reactivated pulmonary TB in adults. Similarly, experimental studies supported the role of host genetic factors in the clinical presentation of illnesses resulting from other fastidious intracellular bacteria. These include IL-6 -174G/C or low mannose-binding (MBL) polymorphisms, which are incriminated in chronic pulmonary conditions triggered by C. pneumoniae, type 2-like cytokine secretion polymorphisms, which are correlated with various clinical patterns of M. pneumoniae infections, and genetic variation in the NOD2 gene, which is an indicator of tubal pathology resulting from Chamydia trachomatis infections. Monocyte/macrophage migration and T lymphocyte recruitment defects are corroborated to ineffective granuloma formation observed among patients with chronic Q fever. Similar genetic polymorphisms have also been suggested for infections caused by T. whipplei although not confirmed yet. In conclusion, this review supports the paramount role of genetic factors in clinical presentations and severity of infections caused by intracellular fastidious bacteria. Genetic predisposition should be further explored through such as exome sequencing.
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Experimental techniques that we have found useful during our studies of insect blood-feeding behaviour are reviewed. Some of the principal findings resulting from these techniques are discussed. Where directly applicable, the work of others is included, but no complete review of the subject has been attempted.
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BACKGROUND: Screening and treatment of latent tuberculosis infection (LTBI) in asylum seekers (AS) may prevent future cases of tuberculosis. As the screening with Interferon Gamma Release Assay (IGRA) is costly, the objective of this study was to assess which factors were associated with LTBI and to define a score allowing the selection of AS with the highest risk of LTBI. METHODS: In across-sectional study, AS seekers recently arrived in Vaud County, after screening for tuberculosis at the border were offered screening for LTBI with T-SPOT.TB and questionnaire on potentially risk factors. The factors associated with LTBI were analyzed by univariate and multivariate regression. RESULTS: Among 393 adult AS, 98 (24.93%) had a positive IGRA response, five of them with active tuberculosis previously undetected. Six factors associated with LTBI were identified in multivariate analysis: origin, travel conditions, marital status, cough, age and prior TB exposure. Their combination leads to a robust LTBI predictive score. CONCLUSIONS: The prevalence of LTBI and active tuberculosis in AS is high. A predictive score integrating six factors could identify the asylum seekers with the highest risk for LTBI.
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The plasma glucose excursion may influence the metabolic responses after oral glucose ingestion. Although previous studies addressed the effects of hyperglycemia in conditions of hyperinsulinemia, it has not been evaluated whether the route of glucose administration (oral vs. intravenous) plays a role. Our aim was to determine the effects of moderately controlled hyperglycemia on glucose metabolism before and after oral glucose ingestion. Eight normal men underwent two oral glucose clamps at 6 and 10 mmol/l plasma glucose. Glucose turnover and cycling rates were measured by infusion of [2H7]glucose. The oral glucose load was labeled by D-[6,6-2H2]glucose to monitor exogenous glucose appearance, and respiratory exchanges were measured by indirect calorimetry. Sixty percent of the oral glucose load appeared in the systemic circulation during both the 6 and 10 mmol/l plasma glucose tests, although less endogenous glucose appeared during the 10 mmol/l tests before glucose ingestion (P < 0.05). This inhibitory effect of hyperglycemia was not detectable after oral glucose ingestion, although glucose utilization was increased (+28%, P < 0.05) due to increased nonoxidative glucose disposal [10 vs. 6 mmol/l: +20%, not significant (NS) before oral glucose ingestion; +40%, P < 0.05 after oral glucose ingestion]. Glucose cycling rates were increased by hyperglycemia (+13% before oral glucose ingestion, P < 0.001; +31% after oral glucose ingestion, P < 0.05) and oral glucose ingestion during both the 6 (+10%, P < 0.05) and 10 mmol/l (+26%, P < 0.005) tests. A moderate hyperglycemia inhibits endogenous glucose production and contributes to glucose tolerance by enhancing nonoxidative glucose disposal. Hyperglycemia and oral glucose ingestion both stimulate glucose cycling.
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BACKGROUND: Screening of peripheral atherosclerosis is increasingly used, but few trials have examined its clinical impact. We aimed to assess whether carotid plaque screening helps smokers to improve their health behaviors and cardiovascular risk factors. METHODS: We randomly assigned 536 smokers aged 40 to 70 years to carotid plaque ultrasonographic screening (US group) vs no screening (control group) in addition to individual counseling and nicotine replacement therapy for all participants. Smokers with at least 1 plaque received pictures of their plaques with a 7-minute structured explanation. The outcomes included biochemically validated smoking cessation at 12 months (primary outcome) and changes in cardiovascular risk factor levels and Framingham risk score. RESULTS: At baseline, participants (mean age, 51.1 years; 45.0% women) smoked an average of 20 cigarettes per day with a median duration of 32 years. The US group had a high prevalence of carotid plaques (57.9%). At 12 months, smoking cessation rates were high, but did not differ between the US and control groups (24.9% vs 22.1%; P = .45). In the US group, cessation rates did not differ according to the presence or absence of plaques. Control of cardiovascular risk factors (ie, blood pressure and low-density lipoprotein cholesterol and hemoglobin A(1c) levels in diabetic patients) and mean absolute risk change in Framingham risk score did not differ between the groups. The mean absolute risk change in Framingham risk score was +0.6 in the US group vs +0.3 in the control group (P = .56). CONCLUSION: In smokers, carotid plaque screening performed in addition to thorough smoking cessation counseling is not associated with increased rates of smoking cessation or control of cardiovascular risk factors. Trial Registration clinicaltrials.gov Identifier: NCT00548665.