Total aortic arch stenting--hemodynamical impact of carotid artery perfusion.

The aim of this experimental study is to evaluate the feasibility and the outcome of total endovascular stent implantation in the aortic arch. Indications for this operation-technique would be acute or chronic dissection of the aortic arch (non-A-non-B dissection) or type B dissection with retrograde extension. Four pigs were canulated via the distal abdominal aorta and a retrograde placement of a Djumbodis arch stent (4-9 cm) was controlled by using intravascular ultrasound and intracardiac ultrasound by the inferior cava vein and under radioscopic control. Cerebral perfusion, by using a flow meter placed on one prepared carotid artery, were controlled before, immediate post-procedural (<1 min), and in the early follow-up after aortic arch stent implantation. During the implantation process, especially during balloon inflation and deflation, mean carotid perfusion decreases slightly. A reactive increase of carotid perfusion after stent placements indicates transitory cerebral hypo-perfusion. Non-covered aortic arch stent implantation is technically feasible and could be a potential treatment option in otherwise inoperable arch dissections. The time required for balloon inflation and deflation causes an important risk of cerebral ischemia. The latter can be reduced by transaxillary perfusion.

The use of rapid dengue diagnostic tests in a routine clinical setting in a dengue-endemic area of Colombia

There is insufficient evidence of the usefulness of dengue diagnostic tests under routine conditions. We sought to analyse how physicians are using dengue diagnostics to inform research and development. Subjects attending 14 health institutions in an endemic area of Colombia with either a clinical diagnosis of dengue or for whom a dengue test was ordered were included in the study. Patterns of test-use are described herein. Factors associated with the ordering of dengue diagnostic tests were identified using contingency tables, nonparametric tests and logistic regression. A total of 778 subjects were diagnosed with dengue by the treating physician, of whom 386 (49.5%) were tested for dengue. Another 491 dengue tests were ordered in subjects whose primary diagnosis was not dengue. Severe dengue classification [odds ratio (OR) 2.2; 95% confidence interval (CI) 1.1-4.5], emergency consultation (OR 1.9; 95% CI 1.4-2.5) and month of the year (OR 3.1; 95% CI 1.7-5.5) were independently associated with ordering of dengue tests. Dengue tests were used both to rule in and rule out diagnosis. The latter use is not justified by the sensitivity of current rapid dengue diagnostic tests. Ordering of dengue tests appear to depend on a combination of factors, including physician and institutional preferences, as well as other patient and epidemiological factors.

From Opacity to Transparency? The Place of Organized Interests within the European Institutions

Regulació dels Grup d'interès en la governança europea és crucial per a una comprensió completa de com s'exerceix el poder a la Unió Europea (UE) i per a una descripció més precisa de com funciona el sistema polític de la UE (i dels seus principis subjacents). Un dels temes principals aquí és com els interessos privats o particulars comprometre amb un interès general o públic encarnat en una forma o altra per aquells que actuen per a la UE. Donada la varietat de temes sensibles en joc, no és d'estranyar que la qüestió de la regulació es troba amb una resistència considerable, sobre tot en la Comissió. No obstant això, els recents obstacles a la integració europea han tingut l'efecte de rellançar un debat que fa que l'ètica i la transparència de les peces centrals de l'agenda. Dinàmiques polítiques actuals semblen donar testimoni d'una creixent receptivitat de la UE a les reivindicacions del moviment ALTER-EU que busca un entorn molt més regulat per cabilderos i funcionaris comunitaris.

Adipose tissue concentrations of persistent organic pollutants and total cancer risk in an adult cohort from Southern Spain: preliminary data from year 9 of the follow-up.

There is an increasing trend in the incidence of cancer worldwide, and it has been accepted that environmental factors account for an important proportion of the global burden. The present paper reports preliminary findings on the influence of the historical exposure to a group of persistent organic pollutants on total cancer risk, at year 9 in the follow-up of a cohort from Southern Spain. A cohort of 368 participants (median age 51 years) was recruited in 2003. Their historical exposure was estimated by analyzing residues of persistent organic pollutants in adipose tissue. Estimation of cancer incidence was based on data from a population-based cancer registry. Statistical analyses were performed using multivariable Cox-regression models. In males, PCB 153 concentrations were positively associated with total cancer risk, with an adjusted hazard ratio (95% confidence interval) of 1.20 (1.01-1.41) for an increment of 100 ng/g lipid. Our preliminary findings suggest a potential relationship between the historical exposure to persistent organic pollutants and the risk of cancer in men. However, these results should be interpreted with caution and require verification during the future follow-up of this cohort.

El proyecto EMECAM: Estudio Multicéntrico Español sobre la Relación entre la Contaminación Atmosférica y la Mortalidad. Antecedentes, participantes, objetivos y métodología.

In recent years, a growing number of studies suggests that increases in air pollution levels may have short-term impact on human health, even at pollution levels similar to or lower than those which have been considered to be safe to date. The different methodological approaches and the varying analysis techniques employed have made it difficult to make a direct comparison among all of the findings, preventing any clear conclusions from being drawn. This has led to multicenter projects such as the APHEA (Short-Term Impact of Air Pollution on Health. A European Approach) within a European Scope. The EMECAM Project falls within the context of the aforesaid multicenter studies and has a wide-ranging projection nationwide within Spain. Fourteen (14) cities throughout Spain were included in this Project (Barcelona, Metropolitan Area of Bilbao, Cartagena, Castellón, Gijón, Huelva, Madrid, Pamplona, Seville, Oviedo, Valencia, Vigo, Vitoria and Saragossa) representing different sociodemographic, climate and environmental situations, adding up to a total of nearly nine million inhabitants. The objective of the EMECAM project is that to asses the short-term impact of air pollution throughout all of the participating cities on the mortality for all causes, on the population and on individuals over age 70, for respiratory and cardiovascular design causes. For this purpose, with an ecological, the time series data analyzed taking the daily deaths, pollutants, temperature data and other factors taken from records kept by public institutions. The period of time throughout which this study was conducted, although not exactly the same for all of the cities involved, runs in all cases from 1990 to 1996. The degree of relationship measured by means of an autoregressive Poisson regression. In the future, the results of each city will be combined by means of a meta-analysis.

Plasma phospholipid long-chain n-3 polyunsaturated fatty acids and body weight change.

OBJECTIVE We investigated the association between the proportion of long-chain n-3 polyunsaturated fatty acids (PUFA) in plasma phospholipids from blood samples drawn at enrollment and subsequent change in body weight. Sex, age, and BMI were considered as potential effect modifiers. METHOD A total of 1,998 women and men participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) were followed for a median of 4.9 years. The associations between the proportion of plasma phospholipid long-chain n-3 PUFA and change in weight were investigated using mixed-effect linear regression. RESULTS The proportion of long-chain n-3 PUFA was not associated with change in weight. Among all participants, the 1-year weight change was -0.7 g per 1% point higher long-chain n-3 PUFA level (95% confidence interval: -20.7 to 19.3). The results when stratified by sex, age, or BMI groups were not systematically different. CONCLUSION The results of this study suggest that the proportion of long-chain n-3 PUFA in plasma phospholipids is not associated with subsequent change in body weight within the range of exposure in the general population.

Controversias en artroplastia total de rodilla

Total knee replacement (TKR) is an operation that has radically improved the quality of life of millions of people during the last decades. However, some technical details, concerning the surgical procedure, are still a matter of a strong debate. In this review of the literature, we have included the best evidence available of the last decade, related to TKR surgery like the use of tourniquet during operation, patellar resufacing, all-polyethilene tibial component, cemented or cementless fixation, mobile bearings, or posterior-stabilized versus cruciate-retaining prosthesis.

Estrategia de reducción de costes en la artroplastia total de rodilla

Aim: Assess the clinical utility of plain radiography in the first postoperative outpatient visit after total knee arthroplasty. Patients and Methods: 200 patients which underwent a total knee arthroplasty from January to May 2012 were analyzed retrospectively, they had two previous control radiographs at hospital discharge and two more at 4-6 weeks after surgery, which were compared, seeking for radiographics signs that would induce a therapeutic changes in the patient’s clinical course. Results: No radiographics signs were observed in the cases studied in the first postoperative visit one month after the surgery, consequently the patient’s treatment plan had no change. Discussion: Our results support those of other authors who have recognized the benefits of reducing the number of postoperative radiographs, improve the cost effectiveness of outpatients care and avoid an extra damage to the patient’s health. We believe that repeated use of serial radiographs in outpatient is simply a custom that has become law, to calm down the patient, and his surgeon, with no scientific evidence to support it use. Conclusions: Our results suggest that the plain AP and L radiographic projection at the first visit, one month later after a TKA, does not provide any clinic information, adds substantial cost to the heath-care system and unnecessary harms the patient.

Tibial component positioning in total knee arthroplasty: bone coverage and extensor apparatus alignment.

Correct positioning of the tibial component in total knee arthroplasty (TKA) must take into account both an optimal bone coverage (defined by a maximal cortical bearing with posteromedial and anterolateral support) and satisfactory patellofemoral tracking. Consequently, a compromise position must be found by the surgeon during the operation to simultaneously meet these two requirements. Moreover, tibial tray positioning depends upon the tibial torsion, which has been shown to act mainly in the proximal quarter of the tibia. Therefore, the correct application of the tibial tray is also theoretically related to the level of bone resection. In this study, we first quantified the torsional profile given by an optimal bone coverage for a symmetrical tibial tray design and for an asymmetrical one. Then, for the two types of tibial trays, we measured the angle difference between optimal bone coverage and an alignment on the middle of the tibial tubercule. Results showed that the values of the torsional profile given by the symmetrical tray were more scattered than those from the asymmetrical one. However, determination of the mean differential angle between the position providing optimal bone coverage and the one providing the best patellofemoral tracking indicated that the symmetrical prosthetic tray offered the best compromise between these two requirements. Although the tibiofemoral joint is known to be asymmetric in both shape and dimension, the asymmetrical tray chosen in this study was found to fulfill this compromise with more difficulty.

Permanent demand excess as business strategy: an analysis of the Brazilian higher-education market

Many Higher Education Institutions (HEIs) establish tuition below the equilibrium price to generate permanent demand excess. This paper first adapts Becker’s (1991) theory to understand why the HEIs price in this way. The fact that students are both consumers and inputs on the education production process gives rise to a market equilibrium where some firms have excess demand and charge high prices, and others charge low prices and have empty seats.Second, the paper analyzes this equilibrium empirically. We estimated the demand for undergraduate courses in Business Administration in the State of São Paulo. The results show that tuition, quality of incoming students and percentage of lecturers holding doctorates degrees are the determining factors of students’ choice. Since the student quality determines the demand for a HEI, it is calculated what the value is for a HEI to get better students; that is the total revenue that each HEI gives up to guarantee excess demand. Regarding the “investment” in selectivity, 39 HEIs in São Paulo give up a combined R$ 5 million (or US$ 3.14 million) in revenue per year per freshman class, which means 7.6% of the revenue coming from a freshman class.

Painful total hip replacement due to sciatic nerve entrapment in scar tissue and lipoma.

Painful total hip replacement remains a challenging problem because of the large amount of possible diagnoses. We report about a 64-year-old female patient who was misdiagnosed during 4 years as psychiatric. She suffered of excruciating left retrotrochanteric pain after the implantation of a cementless total hip replacement and revision because of recurrent hip dislocations. Walking was limited to short distances using two crutches. The work-up at this time included the usual diagnoses and remained unsuccessful. No loosening, infection or malposition of the prosthesis could be found, and she had no neurologic deficits in her operated leg. An MRI was obtained to visualize the retrotrochanteric soft tissues and showed a tight scar surrounding the sciatic nerve, which was also compressed by an adjacent lipoma. Therefore, she was reoperated on to remove the lipoma and the scar tissue around the sciatic nerve. To decrease the risk of recurrent scarring around the sciatic nerve, an adhesion barrier was applied before closure. One year after the operation, the patient has no neurologic deficit, no more pain and is able to walk unlimited distances without crutches. Scar tissue around the sciatic nerve is frequently observed during revision surgery. However, we feel that sciatic nerve entrapment by scar tissue should be a part of the differential diagnosis of painful THR. MRI may be a useful tool to achieve this diagnosis.

Optimització del temps total d'escala d'aeronaus comercials

L'objectiu d'aquest projecte és analitzar com optimitzar el temps total d'escala d'una aeronau comercial, per tal de reduir els costos que suposa que l'aeronau estigui en terra. L'anàlisi es realitza a partir de conèixer quines són les operacions mínimes necessàries que cal dur a terme durant el tumaround i en quin ordre convé realitzar- les perquè el temps total sigui mínim. També s'estudien quins són els mètodes científics ja proposats i quins són els usats en l'actualitat. Fruit de l'estudi es proposa un model que permeti reduir els costos derivats de retards, afegint un temps addicional a l'escala, a partir de dades recollides de l'activitat comercial diària a l’aeroport de Barcelona. Dels resultats obtinguts es conclou que interessa afegir un buffer que absorbeixi possibles incidents, però convé que sigui dividit segons la franja horària del dia, per tal que s'adapti al màxim a les necessitats de cada vol, enlloc d'afegir un mateix buffer a tots els vols de qualsevol hora.

Effect of a pathological scapular tilt after total shoulder arthroplasty.

Total shoulder arthroplasty (TSA) is an accepted and most successfully used treatment for different shoulder pathologies. Different risk factors for the failure of the prosthesis are known. A pathological scapular orientation, observed in elderly people or in patients suffering from neuromuscular diseases, could be a cause of failure, which has not been investigated yet. To test this hypothesis, a numerical musculoskeletal model of the glenohumeral joint was used to compare two TSA cases: a reference normal case and a case with a pathological anterior tilt of the scapula. An active abduction of 150° was simulated. Joint force, contact pattern, polyethylene and cement stress were evaluated for both cases. The pathological tilt slightly increased the joint force and the contact pressure, but also shifted the contact pattern. This eccentric contact increased the stress level within the polyethylene of the glenoid component and within the surrounding cement layer. This adverse effect occurred mainly during the first 60° of abduction. Therefore, a pathological orientation of the scapula may increase the risk of a failure of the cement layer around the glenoid component. These preliminary numerical results should be confirmed by a clinical study.