995 resultados para First-principle
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According to the Taylor principle a central bank should adjust the nominal interest rate by more than one-for-one in response to changes in current inflation. Most of the existing literature supports the view that by following this simple recommendation a central bank can avoid being a source of unnecessary fluctuations in economic activity. The present paper shows that this conclusion is not robust with respect to the modelling of capital accumulation. We use our insights to discuss the desirability of alternative interest rate rules. Our results suggest a reinterpretation of monetary policy under Volcker and Greenspan: The empirically plausible characterization of monetary policy can explain the stabilization of macroeconomic outcomes observed in the early eighties for the US economy. The Taylor principle in itself cannot.
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In this article we present the first empirical analysis on the associations between body size, activity, employment and wages for several European countries. The main advantage of the present work with respect to the previous literature is offered by the comparability of the data and its large geographical coverage. According to our results, for Spanish women, being obese is associated with both a 9% lower wage and probability of being employed, while for Swedish and Danish, obesity is associated with a 12% lower probability of being employed, and a 10% lower wage respectively. In Belgium, obesity is associated with a 19% lower probability of being employed for men. These robust estimates are strongly informative and may be used as a simple statistical rule of thumb to decide the countries in which lab and field experiments should be run.
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Introduction: Population ageing is a worldwide phenomenon that forces us to make radical changes on multiple levels of society. So far, studies have concluded that the health, both physical and mental, of prisoners in general and older prisoners in particular is worse than that of the general population. Prisoners are reported to age faster as compared to adults in the community. However, to date, very little is known about the actual healthcare conditions of older prisoners and almost no substantial knowledge is available concerning their patterns of healthcare use. Method: A quantitative study was conducted in four prisons for male prisoners in Switzerland, including two open and two closed prisons situated in different cantons. In this study, medical records of older prisoners (50+) were obtained from the respective authority upon consent and total anonymity was ensured. Data gathered from all available medical records included basic demographic information, education and prison sentencing. Healthcare data obtained were extensive in nature encompassing data related to illness types, number of visits to different health care providers and hospitals. The corresponding reasons for visits and outcomes of these visits were extracted. All data are analysed using statistical software SPSS 20.0. Results: Data were extracted for a total of 50 older prisoners living in Switzerland. The chosen prisons are located in German-speaking cantons. Preliminary results show that the age average was 56 years. For more than half, this was their first imprisonment. Nevertheless, a third of them were sentenced to measures (Art. 64 Swiss Criminal Code) which means that the length of the detention is indefinite and while release is possible it is in most cases not very likely. This entails that these prisoners will grow old in prison and some will even spend their remaining years there. Concerning their health, a third of the sample reported respiratory and cardiovascular illnesses and half reported suffering from some form of musculoskeletal related pain. Older prisoners were prescribed on average only 3.5 medications, which is significantly fewer than the number of medication prescribed to younger prisoners, whose data were also sampled. Conclusion: Access to healthcare is a right given to all prisoners through the principle of equivalence which is generally exercised in Switzerland. Prisoners growing old in prison will represent a challenge for prison health care services.
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BACKGROUND AND AIM: Recurrent hepatitis C is a major cause of morbidity and mortality after liver transplantation (LT), and optimal treatment algorithms have yet to be defined. Here, we present our experience of the first 21 patients with recurrent hepatitis C treated in Lausanne. PATIENTS AND METHODS: Twenty-one patients with histologyproven recurrent hepatitis C after LT were treated since 2003. Treatment was initiated with pegylated interferon-α2a 135 μg per week and ribavirin 400 mg per day in the majority of patients, and subsequent doses were adapted individually based on on-treatment virological responses and clinical and/or biochemical side effects. RESULTS: On an intention-to-treat basis, sustained virological response (SVR) was achieved in 12/21 (57%) patients (5/11 [45%], 2/3 [67%], 4/5 [80%] and 1/2 [50%] of patients infected with genotypes 1, 2, 3 and 4, respectively). Two patients experienced relapse and 6 did not respond to treatment (NR). Treatment duration ranged from 24 to 90 weeks. It was stopped prematurely due to adverse events in 5/21 (24%) patients (with SVR achieved in 2 patients, NR in 2 patients, and death of one patient awaiting re-transplantation). Of note, SVR was achieved in a patient with combined liver and kidney transplantation. Importantly, SVR was achieved in some patients despite the lack of an early virological response or HCV RNA negativity at week 24. Darbepoetin α and filgrastim were used in 33% and 14%, respectively. CONCLUSION: Individually adapted treatment of recurrent hepatitis C can achieve SVR in a substantial proportion of LT patients. Conventional stopping rules do not apply in this setting so that prolonged therapy may be useful in selected patients.
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In this study of the efficacy and safety of isradipine as first-line therapy in hypertension, 1,647 patients enrolled; 1,472 completed the 4-week placebo run-in period and began treatment with isradipine at 2.5 mg twice daily for 4 weeks. During placebo, 11% (n = 175) of the 1,647 patients withdrew because of normalization of blood pressure, side effects, noncompliance, violation of the study protocol, side effects from concomitant therapy, or other reasons. During isradipine therapy (n = 1,376), blood pressure decreased from 168 +/- 18/102 +/- 8 mm Hg at the end of the placebo period to 155 +/- 17/94 +/- 9 mm Hg after 2 weeks (p less than 0.001) and 151 +/- 16/92 +/- 9 mm Hg after 4 weeks (p less than 0.001). During active treatment, 6.4% (n = 94) were withdrawn because of flushing, headache, edema, palpitations, gastrointestinal side effects, skin rashes, or other side effects, and two patients because of lack of efficacy. The side effect score in the remaining patients worsened for flushing, remained unchanged for edema, but significantly improved for palpitations, fatigue, dizziness, headache, and nervousness. After 4 weeks, 60% of patients had diastolic blood pressures of less than or equal to 90 mm Hg. Thus, isradipine is effective and safe as first-line therapy in patients with primary hypertension as seen in general practice.
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Objective To analyze pelvic floor muscle strength (PFMS), urinary continence and quality of life related to urinary incontinence (UI) of women in the first trimester of pregnancy. Method Cross-sectional study with a sample of 500 women who started prenatal care in a complementary healthcare facility in Guarulhos, state of São Paulo, from 2012 and 2013. Pelvic floor muscle strength was evaluated through perineometry. The pregnant women who presented UI answered the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF). Results It was found that maternal age (OR=1.06; CI95% 1.02-1.11) and prior UI (OR=15.12; 95%CI 8.19-27.92) are the variables that, in tandem, best explain the occurrence of UI at the beginning of pregnancy. The mean score on the ICIQ-SF was 8.2 (SD=3.9), considered a moderate impact on quality of life. Conclusion Older pregnant women with prior UI are more likely to have UI in the first trimester of pregnancy.
MEDICAL STUDENT IN THE FAMILY HEALTH STRATEGY ON THE FIRST YEARS OF COLLEGE: PERCEPTION OF GRADUATES
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There is a lack of knowledge about the effective value of the experience gained by medical students who participate in the Family Health Strategy (Estratégia Saúde da Família (ESF)) during the early stages of their medical training. This teaching strategy is based on learning by experiencing the problems that exist in real life. This study proposed to understand the value of this teaching strategy from the viewpoint of the students who had participated, after their graduation. The method adopted was a qualitative study conducted through interviews with students who graduated in the years 2009, 2010 and 2011. The data analysis used the hermeneutic dialectic technique as its model. The graduates considered that this experience enabled them to understand the organization and functioning of the health service and the context of the daily life of the users. This experience facilitated the doctor patient relationship, the development of clinical reasoning and the bond with the user. However the students emphasized that a lack of maturity prevented them gaining a higher level of benefit from the experience. Therefore, although the structure of the course is permeated by advances and challenges, it was concluded that this experience contributed to the student's learning of certain essential elements of medical training.
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Functional specialization is tightly linked to the ability of eukaryotic cells to acquire a particular shape. Cell morphogenesis, in turn, relies on the capacity to establish and maintain cell "polarity", which is achieved by orienting the trafficking of signaling molecules and organelles towards specific cellular locations and/or membrane domains. The "oriented" transport is based upon cytoskeletal polymers, microtubules and actin filaments, which serve as tracks for molecular motors. These latter generate motion that is translated either into pulling forces or directed transport. Fission yeast, a rod-like unicellular eukaryote, shapes itself by restricting growth at cell tips through the concerted activity of microtubules and actin cables. Microtubules, which assemble into 2-6 bundles and run parallel to the long axis of the cell, serve to orient growth to the tips. Growth is supported by the actin cytoskeleton, which provides tracks, the cables, for motor-based transport of secretory vesicles. The molecular motors, which bind cargos and deliver them to the tips along cables, are also known as type V myosins (hereafter indicated as myosin V). How the bundles of parallel actin filaments, i.e. the cables, extend from the tips through the cell and whether they serve any other purpose, besides providing tracks, is poorly understood. It is also unclear how the crosstalk between the two cytoskeletal systems is achieved. These are the basic questions I addressed during my PhD. The first part of the thesis work (Chapter two) suggests that the sole function of actin cables in polarized growth is to serve as tracks for motors. The data indicate that cells may have evolved two cytoskeletal systems to provide robustness to the polarization process but in principle a unique cytoskeleton might have been able to direct and support polarized growth. How actin cables are organized within the cell to optimize cargo transport is addressed later on (Chapter three). The major finding, based on the actin cable defect of cells lacking myosin Vs, is that actin filaments self-organize through the activity of the transport motors. In fact, by delivering cargos to cell tips and exerting physical pulling forces on actin filaments, Myosin Vs contribute not only to polarize cargo transport but also actin tracks. Among the cargos transported by Myosin V, which may be relevant to its function in organizing cables, there is likely the endoplasmic reticulum (ER). Actin cables, which run parallel to cortical ER, may serve as tracks for Myosin V. Myosin V-driven displacement, in turn, may account for the dynamic expansion and organization of ER during polarized growth as suggested in Chapter four. The last part of the work (Chapter five) highlights the existence of a crosstalk between actin and microtubules. In absence of myosin V, indeed, microtubules contribute to actin cable organization, likely playing a scaffolding/tethering function. Whether or not the kinesin 1, Klp3, plays any role in such process has to be demonstrated. In conclusion the work proposes a novel role for myosin Vs in actin organization, besides its transport function, and provides molecular tools to further dissect the role of this type of myosin in fission yeast. - La spécialisation fonctionnelle est étroitement connectée à la capacité des cellules eucaryotes d'acquérir une forme particulière. La morphogenèse cellulaire à son tour, est basée sur la capacité d'établir et de maintenir la polarité cellulaire, polarité réalisée en orientant le trafic des molécules signales et des organelles vers des zones cellulaires spécifiques. Ce transport directionnel dépend des polymères du cytosquelette, microtubules et microfilaments, qui servent comme des voies pour les moteurs moléculaires. Ces derniers engendrent du mouvement, traduit soit en force de traction soit en transport directionnel. La levure fissipare, un eucaryote unicellulaire en forme de bâtonnet, acquière sa forme en limitant sa croissance aux extrémités par l'action concertée des microtubules et de l'actine. Les microtubules, qui s'assemblent de façon antiparallèle et parcourent la cellule parallèlement à l'axe longitudinal, servent à orienter la croissance aux extrémités. Cette croissance est permise par le cytosquelette d'actine, fournissant des voies, les câbles, pour le transport actif des vésicules de sécrétion. Les moteurs moléculaires, responsables de ce transport actif sont aussi appelés myosines de type V (par la suite appelés myosines V). La manière dont ces câbles s'étendent depuis l'extrémité jusqu'à l'intérieur de la cellule est peu connue. De plus, on ignore également si ces câbles présentent une fonction autre que le transport. L'interaction entre les deux cytosquelettes est également obscure. Ce sont ces questions de base auxquelles j'ai tenté de répondre lors de ma thèse. La première partie de cette thèse (chapitre II) suggère que les câbles d'actine, pendant la croissance polarisée, fonctionnent uniquement comme des voies pour les moteurs moléculaires. Les données indiqueraient que les cellules ont fait évoluer deux systèmes de cytosquelette pour assurer plus de robustesse au processus de polarisation, bien que, comme nous le verrons, un système unique est suffisant. Au chapitre III, nous verrons comment les câbles d'actine sont organisés à l'intérieur de la cellule afin d'optimiser le transport des cargo. La découverte majeure, réalisée en observant des cellules dont la myosine V fait défaut, est que ces filaments d'actine s'auto organisent grâce au passage des moteurs moléculaires le long de ces voies. En réalité, en délivrant les cargos aux extrémités de la cellule et en exerçant des forces de traction sur les câbles, les myosines V contribuent non seulement à polariser le transport mais également à polariser les voies elles mêmes. Nous verrons également au chapitre IV, que parmi les cargos importants pour l'organisation des câbles, il y aurait le réticulum endoplasmique (RE). En effet, les câbles d'actine, qui s'étalent parallèlement au RE cortical, pourraient servir comme voie pour la myosine V. Cette dernière en retour pourrait être responsable de l'expansion dynamique et de l'organisation du RE pendant la croissance polarisée.
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A solid-phase enzyme immunoassay using both mouse monoclonal and goat polyclonal antibodies against carcinoembryonic antigen (CEA) was developed. The assay detects 0.6 to 1.2 ng of CEA per ml of serum and has 3 incubation steps which can be performed in 1 day. Polystyrene balls coated with polyclonal goat anti-CEA antibodies are first incubated with heat-extracted serum samples. Bound CEA is then detected by addition of mouse monoclonal antibodies, followed by goat IgG anti-mouse IgG1 coupled to alkaline phosphatase. Results with this enzyme immunoassay using monoclonal antibodies (M-EIA) have been compared with those obtained by the conventional inhibition radioimmunoassay (RIA) using goat antiserum. Three hundred and eighty serum samples from 167 patients with malignant or non-malignant diseases and from 134 normal individuals with or without heavy smoking habits were analyzed by the 2 assays. Excellent correlation between the results of the 2 assays was obtained, but the M-EIA, using monoclonal antibodies from a single hybridoma, did not discriminate better than the conventional RIA between CEA produced by different types of carcinoma and between CEA associated with malignant or non-malignant diseases. Follow-up studies of several patients by sequential CEA determinations with the 2 assays showed that the M-EIA was as accurate as the RIA for the detection of tumor recurrences.
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Although hemoglobin (Hb) is mainly present in the cytoplasm of erythrocytes (red blood cells), lower concentrations of pure, cell-free Hb are released permanently into the circulation due to an inherent intravascular hemolytic disruption of erythrocytes. Previously it was shown that the interaction of Hb with bacterial endotoxins (lipopolysaccharides, LPS) results in a significant increase of the biological activity of LPS. There is clear evidence that the enhancement of the biological activity of LPS by Hb is connected with a disaggregation of LPS. From these findings one questions whether the property to enhance the biological activity of endotoxin, in most cases proven by the ability to increase the cytokine (tumor-necrosis-factor-alpha, interleukins) production in human mononuclear cells, is restricted to bacterial endotoxin or is a more general principle in nature. To elucidate this question, we investigated the interaction of various synthetic and natural virulence (pathogenicity) factors with hemoglobin of human or sheep origin. In addition to enterobacterial R-type LPS a synthetic bacterial lipopeptide and synthetic phospholipid-like structures mimicking the lipid A portion of LPS were analysed. Furthermore, we also tested endotoxically inactive LPS and lipid A compounds such as those from Chlamydia trachomatis. We found that the observations made for endotoxically active form of LPS can be generalized for the other synthetic and natural virulence factors: In every case, the cytokine-production induced by them is increased by the addition of Hb. This biological property of Hb is connected with its physical property to convert the aggregate structures of the virulence factors into one with cubic symmetry, accompanied with a considerable reduction of the size and number of the original aggregates.
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There is increasing evidence that the clinical efficacy of tamoxifen, the first and most widely used targeted therapy for estrogen-sensitive breast cancer, depends on the formation of the active metabolites 4-hydroxy-tamoxifen and 4-hydroxy-N-desmethyl-tamoxifen (endoxifen). Large inter-individual variability in endoxifen plasma concentrations has been observed and related both to genetic and environmental (i.e. drug-induced) factors altering CYP450s metabolizing enzymes activity. In this context, we have developed an ultra performance liquid chromatography-tandem mass spectrometry method (UPLC-MS/MS) requiring 100 μL of plasma for the quantification of tamoxifen and three of its major metabolites in breast cancer patients. Plasma is purified by a combination of protein precipitation, evaporation at room temperature under nitrogen, and reconstitution in methanol/20 mM ammonium formate 1:1 (v/v), adjusted to pH 2.9 with formic acid. Reverse-phase chromatographic separation of tamoxifen, N-desmethyl-tamoxifen, 4-hydroxy-tamoxifen and 4-hydroxy-N-desmethyl-tamoxifen is performed within 13 min using elution with a gradient of 10 mM ammonium formate and acetonitrile, both containing 0.1% formic acid. Analytes quantification, using matrix-matched calibration samples spiked with their respective deuterated internal standards, is performed by electrospray ionization-triple quadrupole mass spectrometry using selected reaction monitoring detection in the positive mode. The method was validated according to FDA recommendations, including assessment of relative matrix effects variability, as well as tamoxifen and metabolites short-term stability in plasma and whole blood. The method is precise (inter-day CV%: 2.5-7.8%), accurate (-1.4 to +5.8%) and sensitive (lower limits of quantification comprised between 0.4 and 2.0 ng/mL). Application of this method to patients' samples has made possible the identification of two further metabolites, 4'-hydroxy-tamoxifen and 4'-hydroxy-N-desmethyl-tamoxifen, described for the first time in breast cancer patients. This UPLC-MS/MS assay is currently applied for monitoring plasma levels of tamoxifen and its metabolites in breast cancer patients within the frame of a clinical trial aiming to assess the impact of dose increase on tamoxifen and endoxifen exposure.