Geometric optimal control of the contrast imaging problem in Nuclear Magnetic Resonance

The objective of this article is to introduce the tools to analyze the contrast imaging problem in Nuclear Magnetic Resonance. Optimal trajectories can be selected among extremal solutions of the Pontryagin Maximum Principle applied to this Mayer type optimal problem. Such trajectories are associated to the question of extremizing the transfer time. Hence the optimal problem is reduced to the analysis of the Hamiltonian dynamics related to singular extremals and their optimality status. This is illustrated by using the examples of cerebrospinal fluid / water and grey / white matter of cerebrum.Comment: 30 pages, 13 figur

Energy minimization problem in two-level dissipative quantum control: meridian case

International audienceWe analyze the energy-minimizing problem for a two-level dissipative quantum system described by the Kossakowsky-Lindblad equation. According to the Pontryagin Maximum Principle (PMP), minimizers can be selected among normal and abnormal extremals whose dynamics are classified according to the values of the dissipation parameters. Our aim is to improve our previous analysis concerning 2D solutions in the case where the Hamiltonian dynamics are integrable

Comparative study of paediatric prescription drug utilization between the spanish and immigrant population

<p>Abstract</p> <p>Background</p> <p>The immigrant population has increased greatly in Spain in recent years to the point where immigrants made up 12% of the infant population in 2008. There is little information available on the profile of this group with regard to prescription drug utilization in universal public health care systems such as that operating in Spain. This work studies the overall and specific differences in prescription drug utilization between the immigrant and Spanish population.</p> <p>Methods</p> <p>Use was made of the Aragonese Health Service databases for 2006. The studied population comprises 159,908 children aged 0-14 years, 13.6% of whom are foreign nationals. Different utilization variables were calculated for each group. Prescription-drug consumption is measured in Defined Daily Doses (DDD) and DDD/1000 persons/day/(DID).</p> <p>Results</p> <p>A total of 833,223 prescriptions were studied. Utilization is lower for immigrant children than in Spanish children for both DID (66.27 v. 113.67) and average annual expense (€21.55 v. €41.14). Immigrant children consume fewer prescription drugs than Spanish children in all of the therapy groups, with the most prescribed (in DID) being: respiratory system, anti-infectives for systemic use, nervous system, sensory organs. Significant differences were observed in relation to the type of drugs and the geographical background of immigrants.</p> <p>Conclusion</p> <p>Prescription drug utilization is much greater in Spanish children than in immigrant children, particularly with reference to bronchodilators (montelukast and terbutaline) and attention-disorder hyperactivity drugs such as methylphenidate. There are important differences regarding drug type and depending on immigrants' geographical backgrounds that suggest there are social, cultural and access factors underlying these disparities.</p

Solisluumurtumien konservatiivinen ja operatiivinen hoito : Systemaattinen kirjallisuuskatsaus 1190 potilaasta

Peer reviewe

Comparación de costes de tres tratamientos del cáncer de próstata localizado en España : prostatectomía radical, braquiterapia prostática y radioterapia conformacional externa 3D

Altres ajuts: AATM/086/24/2000Objetivo: comparar los costes de los tratamientos más establecidos para el cáncer de próstata localizado según grupos de riesgo, edad y comorbilidad, desde la perspectiva del proveedor asistencial. Métodos: comparación de costes en pacientes reclutados consecutivamente entre 2003 y 2005 en una unidad funcional de tratamiento del cáncer de próstata. La utilización de servicios hasta 6 meses después del inicio del tratamiento se obtuvo de las bases de datos hospitalarias, y los costes directos se estimaron mediante cálculo microcoste. La información sobre las características clínicas de los pacientes y los tratamientos recogió prospectivamente. Los costes se compararon mediante tests no paramétricos de comparación de medianas (Kruskall-Wallis) y un modelo semilogarítmico de regresión múltiple. Resultados: la diferencia de costes fue estadísticamente significativa: medianas de 3229.10D, 5369.00Dy 6265.60D para los pacientes tratados con radioterapia conformacional externa 3D, braquiterapia, y prostatectomía radical retro pública, respectivamente (p <0,001). En el análisis multivariado (R2 ajustada=0,8), los costes medios de la braquiterapia y de la radioterapia externa fueron significativamente menores que los de la prostatectomía (coeficiente -0,212 y -0,729, respectivamente). Conclusiones: la prostatectomía radical resultó ser la opción terapéutica de mayor coste. En general, los costes estimados en nuestro estudio son inferiores a los publicados en otros ámbitos. La opción terapéutica explica gran parte de los costes, y tanto la comorbilidad como el grupo de riesgo no mostraron efecto independiente del tratamiento sobre los costes totales.Objective: To compare the initial costs of the three most established treatments for clinically localized prostate cancer according to risk, age and comorbidity groups, from the healthcare provider's perspective. Methods: We carried out a cost comparison study in a sample of patients consecutively recruited between 2003 and 2005 from a functional unit for prostate cancer treatment in Catalonia (Spain). The use of services up to 6 months after the treatment start date was obtained from hospital databases and direct costs were estimated by micro-cost calculation. Information on the clinical characteristics of patients and treatments was collected prospectively. Costs were compared by using nonparametric tests comparing medians (Kruskall-Wallis) and a semi-logarithmic multiple regression model. Results: Among the 398 patients included, the cost difference among treatments was statistically significant: medians were €3,229.10, €5,369.00 and €6,265.60, respectively, for the groups of patients treated with external 3D conformal radiotherapy, brachytherapy and radical retropublic prostatectomy, (p<0.001). In the multivariate analysis (adjusted R=0.8), the average costs of brachytherapy and external radiotherapy were significantly lower than that of prostatectomy (coefficient -0.212 and -0.729, respectively). Conclusions: Radical prostatectomy proved to be the most expensive treatment option. Overall, the estimated costs in our study were lower than those published elsewhere. Most of the costs were explained by the therapeutic option and neither comorbidity nor risk groups showed an effect on total costs independent of treatment

Determinants of health care utilization by immigrants in Portugal

<p>Abstract</p> <p>Background</p> <p>The increasing diversity of population in European Countries poses new challenges to national health systems. There is a lack of data on accessibility and use of health care services by migrants, appropriateness of the care provided, client satisfaction and problems experienced when confronting the health care system. This limits knowledge about the multiple determinants of the utilization of health services. The aim of this study was to describe the access of migrants to health care and its determinants in Portugal.</p> <p>Methods</p> <p>The study sample included 1513 immigrants (53% men), interviewed at the National Immigrant Support Centre, in Lisbon. Data were collected using questionnaires. The magnitude of associations between use of National Health Service and socio-demographic variables was estimated by means of odds ratios (OR) at 95% confidence intervals, calculated using logistic regression.</p> <p>Results</p> <p>Among participants, 3.6% stated not knowing where to go if facing a health problem. Approximately 20% of the respondents reported that they had never used the National Health Service, men more than women. Among National Health Service users, 35.6% attended Health Centres, 12% used Hospital services, and 54.4% used both. Among the participants that ever used the health services, 22.4% reported to be unsatisfied or very unsatisfied. After adjusting for all variables, utilization of health services, among immigrant men, remained significantly associated with length of stay, legal status, and country of origin. Among immigrant women, the use of health services was significantly associated with length of stay and country of origin.</p> <p>Conclusion</p> <p>There is a clear need to better understand how to ensure access to health care services and to deliver appropriate care to immigrants, and that special consideration must be given to recent and undocumented migrants. To increase health services use, and the uptake of prevention programs, barriers must be identified and approaches to remove them developed, through coherent and comprehensive strategies.</p

Defective HNF4alpha-dependent gene expression as a driver of hepatocellular failure in alcoholic hepatitis

Alcoholic hepatitis (AH) is a life-threatening condition characterized by profound hepatocellular dysfunction for which targeted treatments are urgently needed. Identification of molecular drivers is hampered by the lack of suitable animal models. By performing RNA sequencing in livers from patients with different phenotypes of alcohol-related liver disease (ALD), we show that development of AH is characterized by defective activity of liver-enriched transcription factors (LETFs). TGFβ1 is a key upstream transcriptome regulator in AH and induces the use of HNF4α P2 promoter in hepatocytes, which results in defective metabolic and synthetic functions. Gene polymorphisms in LETFs including HNF4α are not associated with the development of AH. In contrast, epigenetic studies show that AH livers have profound changes in DNA methylation state and chromatin remodeling, affecting HNF4α-dependent gene expression. We conclude that targeting TGFβ1 and epigenetic drivers that modulate HNF4α-dependent gene expression could be beneficial to improve hepatocellular function in patients with AH

Perfil de la casuística hospitalaria de la población inmigrante en Barcelona Profile of the hospital case mix of the immigrant population in Barcelona, Spain

Objetivo: A pesar de que en los últimos 5 años la población inmigrante se ha triplicado en ciudades como Barcelona, hasta el momento no se ha evaluado de forma rigurosa el impacto de este colectivo en el sistema sanitario. El objetivo del presente estudio ha sido comparar el perfil de la hospitalización de la población inmigrante con la autóctona, desde el punto de vista de la casuística, gravedad, características demográficas y consumo de estancias. Material y métodos: Se han analizado las 15.057 altas del Hospital del Mar de Barcelona en el año 2000. Este hospital asiste el 60% de los ingresos hospitalarios del distrito de Ciutat Vella, distrito que presentaba en el año 2000 un porcentaje de inmigrantes residentes del 21%. Se han comparado las características sociodemográficas y de casuística de los pacientes en razón de ser o no inmigrantes. También se ha comparado el consumo de recursos hospitalarios teniendo en cuenta la edad, la casuística (grupos relacionados por el diagnóstico) y la gravedad (severidad, complicaciones y comorbilidades) de la patología atendida. Resultados: La población inmigrante ha presentado una casuística distinta de la autóctona por la marcada diferencia en la edad y por su mayor tasa de fecundidad. El 33% de los ingresos de inmigrantes han sido partos. El coste medio de las altas de inmigrantes de países de renta baja valorado en consumo de estancias hospitalarias, ha sido un 30% menor que el del resto de las altas. Una vez ajustadas la edad, la casuística y la severidad, el consumo de estancias hospitalarias en la población inmigrante ha sido significativamente menor. La diferencia se ha cifrado en un 5% cuando sólo se ha ajustado por patología y en un 10% cuando han sido considerados todos los factores. Conclusiones: Las diferencias en la casuística vienen marcadas por la edad y por las diferencias socioculturales. La pirámide de edad de la población hospitalaria inmigrante recompone la envejecida estructura de edad de los pacientes autóctonos y plantea la necesidad de recuperar el mayor peso de los servicios de ginecología-obstetricia y pediatría. El hecho de que exista menor consumo de recursos por alta hospitalaria en la población inmigrante de países de renta baja contradice la relación esperada de inmigrante-peor situación socioeconómica-mayor intensidad de consumo de recursos por alta hospitalaria. Deben proponerse nuevas hipótesis de trabajo y análisis que permitan explicar esta realidad.Objective: Although the immigrant population in cities such as Barcelona has tripled in the last five years, until now the impact of this group on the health system has not been rigorously evaluated. The aim of this study was to compare hospital resource utilization among the immigrant population with that among the native population through case mix, demographic characteristics and hospital day use. Material and methods: We analyzed 15,057 discharges from Hospital del Mar in Barcelona in 2000. This hospital attends 60% of admissions from the Ciutat Vella district. In 2000, 21% of the population of this district were immigrants. Socio-demographic patient characteristics and case mix were compared between the immigrant and the native population. Hospital resource use was compared according to age, case mix (diagnosis related groups) and seriousness (severity, complications and comorbidities) of the events requiring medical care. Results: The case mix of the immigrant population differed from that of the autochthonous population due to pronounced ge differences and a higher fertility rate. Thirty-three percent of immigrant admissions were for deliveries. The mean cost of discharge of immigrants from low-income countries was 30% lower than that for the remaining discharges. After adjusting for age, case mix and severity, length of stay among the immigrant population was significantly shorter. A 5% reduction was found after adjusting for case mix and a 10% reduction was found when all the factors were considered. Conclusions: Case mix differences are due to age and socio-cultural factors. Immigrants are rejuvenating the ageing native population and the role of gynecology-obstetrics and pediatrics needs to be increased. The finding that resource use per discharge is lower among immigrants from low-income countries contradicts the expectation that lower socioeconomic status leads to higher hospital resource use intensity. Therefore, new hypotheses and analyses that explain this situation should be put forward