Marketing education, distance learning and hypermedia : teaching 'current issues in marketing' in a virtual campus

This article reports on a project at the Universitat Oberta de Catalunya (UOC: The Open University of Catalonia, Barcelona) to develop an innovative package of hypermedia-based learning materials for a new course entitled 'Current Issues in Marketing'. The UOC is a distance university entirely based on a virtual campus. The learning materials project was undertaken in order to benefit from the advantages which new communication technologies offer to the teaching of marketing in distance education. The article reviews the main issues involved in incorporating new technologies in learning materials, the development of the learning materials, and their functioning within the hypermedia based virtual campus of the UOC. An empirical study is then carried out in order to evaluate the attitudes of students to the project. Finally, suggestions for improving similar projects in the future are put forward.

Reversible and high capacity data hiding in medical images

In this paper we introduce a highly efficient reversible data hiding system. It is based on dividing the image into tiles and shifting the histograms of each image tile between its minimum and maximum frequency. Data are then inserted at the pixel level with the largest frequency to maximize data hiding capacity. It exploits the special properties of medical images, where the histogram of their nonoverlapping image tiles mostly peak around some gray values and the rest of the spectrum is mainlyempty. The zeros (or minima) and peaks (maxima) of the histograms of the image tiles are then relocated to embed the data. The grey values of some pixels are therefore modified.High capacity, high fidelity, reversibility and multiple data insertions are the key requirements of data hiding in medical images. We show how histograms of image tiles of medical images can be exploited to achieve these requirements. Compared with data hiding method applied to the whole image, our scheme can result in 30%-200% capacity improvement and still with better image quality, depending on the medical image content. Additional advantages of the proposed method include hiding data in the regions of non-interest and better exploitation of spatial masking.

Stress ulcer prophylaxis in non-critically ill patients: a prospective evaluation of current practice in a general surgery department.

RATIONALE, AIMS AND OBJECTIVES: There is little evidence regarding the benefit of stress ulcer prophylaxis (SUP) outside a critical care setting. Overprescription of SUP is not devoid of risks. This prospective study aimed to evaluate the use of proton pump inhibitors (PPIs) for SUP in a general surgery department. METHOD: Data collection was performed prospectively during an 8-week period on patients hospitalized in a general surgery department (58 beds) by pharmacists. Patients with a PPI prescription for the treatment of ulcers, gastro-oesophageal reflux disease, oesophagitis or epigastric pain were excluded. Patients admitted twice during the study period were not reincluded. The American Society of Health-System Pharmacists guidelines on SUP were used to assess the appropriateness of de novo PPI prescriptions. RESULTS: Among 255 patients in the study, 138 (54%) received a prophylaxis with PPI, of which 86 (62%) were de novo PPI prescriptions. A total of 129 patients (94%) received esomeprazole (according to the hospital drug policy). The most frequent dosage was at 40 mg once daily. Use of PPI for SUP was evaluated in 67 patients. A total of 53 patients (79%) had no risk factors for SUP. Twelve and two patients had one or two risk factors, respectively. At discharge, PPI prophylaxis was continued in 33% of patients with a de novo PPI prescription. CONCLUSIONS: This study highlights the overuse of PPIs in non-intensive care unit patients and the inappropriate continuation of PPI prescriptions at discharge. Treatment recommendations for SUP are needed to restrict PPI use for justified indications.

Fetoscopic laser therapy for twin-twin transfusion syndrome: beyond current gestational age limits.

Both "early" (< 16 weeks' gestation) and "late" (> 26 weeks' gestation) presentations of twin-twin transfusion syndrome (TTTS) are rare and challenging complications of monochorionic/diamniotic twin pregnancies. Growing evidence suggests that fetoscopic laser therapy for both "early" and "late" TTTS is feasible, safe, and yields similar outcomes to cases treated between 16 and 26 weeks' gestation. We suggest reevaluation of conventional gestational age guidelines for laser therapy for TTTS.

Syndrome de vasoconstriction cérébrale réversible : identifications de facteurs pronostiques = [Reversible cerebral vasoconstriction syndrome identification of pronostic factors]

Objectif : Le syndrome de vasoconstriction cérébrale réversible (SVCR) est une entité clinico-radiologique associant des céphalées paroxystiques à un vasospasme uni- ou multifocal réversible des artères cérébrales avec ou sans déficit neurologique transitoire ou crise comitiale. Le but de notre étude est de rechercher les facteurs de mauvais pronostic des patients présentant un SVCR. Méthode : Nous avons réalisé une étude rétrospective des imageries vasculaires cérébrales invasives et non invasives entre janvier 2006 et 2011 et avons retenu 10 patients présentant les critères du RCVS. Les données démographiques, facteurs de risque vasculaires ainsi que l'évolution de chaque patient ont été noté. Résultats : Sept des 10 patients sont des femmes, avec un âge médian de 46 ans. Quatre patients ne présentaient pas de facteur étiologique, deux femmes se trouvaient en période post-partum (entre la première et la troisième semaine) et les trois autres cas sont induits par des drogues vaso-actives (cannabis pour 2 cas dont un associé à la cyclosporine, sumatriptan pour un cas). La durée moyenne du suivi est de 10,2 mois (0¬28 mois). Deux patients ont présentés une séquelle neurologique : un a gardé des troubles phasiques et l'autre une hémianopsie latérale homonyme. Deux autres patients sont décédés dans les suites, ce qui est inhabituel. Nous n'avons pas trouvé de corrélation d'évolution différente entre les cas de SVCR primaire ou secondaire. Les seules facteurs corrélaient à l'évolution clinique sont le status neurologique à l'admission et la présence de lésion parenchymateuse (ischémie ou hématome) à l'imagerie. Conclusion : La vasoconstriction cérébrale réversible impliquant des déficits neurologiques ou la mort a été, rarement, rapportée. Nous devons garder à l'esprit qu'une telle évolution peut survenir notamment pour les cas présentant un état neurologique dégradé à l'admission ou présentant des lésions parenchymateuses à l'imagerie.

Combinations of vascular endothelial growth factor pathway inhibitors with metronomic chemotherapy: Rational and current status.

Chemotherapy given in a metronomic manner can be administered with less adverse effects which are common with conventional schedules such as myelotoxicity and gastrointestinal toxicity and thus may be appropriate for older patients and patients with decreased performance status. Efficacy has been observed in several settings. An opportunity to improve the efficacy of metronomic schedules without significantly increasing toxicity presents with the addition of anti-angiogenic targeted treatments. These combinations rational stems from the understanding of the importance of angiogenesis in the mechanism of action of metronomic chemotherapy which may be augmented by specific targeting of the vascular endothelial growth factor (VEGF) pathway by antibodies or small tyrosine kinase inhibitors. Combinations of metronomic chemotherapy schedules with VEGF pathway targeting drugs will be discussed in this paper.

Reversible mitochondrial respiratory chain impairment during symptomatic hyperlactatemia associated with antiretroviral therapy

Direct evidence confirming the hypothesis that a dysfunction of the mitochondrial respiratory chain (MRC) underlies the pathogenesis of hyperlactatemia associated with highly active antiretroviral therapy (HAART) is scarce. We studied mitochondrial DNA (mtDNA) content and MRC function in the skeletal muscle of an HIV-infected patient during an episode of symptomatic hyperlactatemia. Skeletal muscle biopsy was performed during the episode when the patient was symptomatic and 3 months later when the patient was clinically recovered. Assessment of mitochondria was performed using histological, polarographic, spectrophotometrical, and Southern blot and real time PCR DNA quantification methods. The histological study disclosed extensive mitochondrial impairment in the form of ragged-red fibers or equivalents on oxidative reactions. These findings were associated with an increase in mitochondrial content and a decrease in both mitochondrial respiratory capacity and MRC enzyme activities. Mitochondrial DNA content declined to 53% of control values. Mitochondrial abnormalities had almost disappeared later when the patient became asymptomatic. Our findings support the hypothesis that MRC dysfunction stands at the basis of HAART-related hyperlactatemia.

Reversible mitochondrial respiratory chain impairment during symptomatic hyperlactatemia associated with antiretroviral therapy

Direct evidence confirming the hypothesis that a dysfunction of the mitochondrial respiratory chain (MRC) underlies the pathogenesis of hyperlactatemia associated with highly active antiretroviral therapy (HAART) is scarce. We studied mitochondrial DNA (mtDNA) content and MRC function in the skeletal muscle of an HIV-infected patient during an episode of symptomatic hyperlactatemia. Skeletal muscle biopsy was performed during the episode when the patient was symptomatic and 3 months later when the patient was clinically recovered. Assessment of mitochondria was performed using histological, polarographic, spectrophotometrical, and Southern blot and real time PCR DNA quantification methods. The histological study disclosed extensive mitochondrial impairment in the form of ragged-red fibers or equivalents on oxidative reactions. These findings were associated with an increase in mitochondrial content and a decrease in both mitochondrial respiratory capacity and MRC enzyme activities. Mitochondrial DNA content declined to 53% of control values. Mitochondrial abnormalities had almost disappeared later when the patient became asymptomatic. Our findings support the hypothesis that MRC dysfunction stands at the basis of HAART-related hyperlactatemia.

Heart transplantation: current practice and outlook to the future.

QUESTIONS UNDER STUDY: The field of heart transplantation has seen substantial progress in the last 40 years. The breakthroughs in long-term survival were followed by a period of stagnation in the last decade. This review summarises current recommendations for the identification of candidates for heart transplantation and their immunological and non-immunological postoperative follow-up. RESULTS: The progress made in the treatment of patients with advanced heart failure has considerably changed the profile of candidates for heart transplantation. Patients are older, and the load of co-morbidities is more important requiring careful evaluation for candidacy. Long-standing research in the field of immunosuppression made available various drugs, which decrease the risk of acute allograft rejection and prolong survival after heart transplantation. Powerful new molecules are entering early phase clinical studies, suggesting further improvement in the near future. As a consequence, treatment of non-immunological co-morbidity after heart transplantation will gain in importance, however, the base of evidence guiding current recommendations is poor. CONCLUSIONS: The substantial progress in heart failure treatment and immunosuppression after heart transplantation has changed the profile of heart transplant recipients. The arrival of new molecules will provide additional alternatives for immunosuppressive treatment while studies have to address non-immunological treatment in order to improve long-term survival after heart transplantation.