Image-Derived Input Function for Human Brain Using High Resolution PET Imaging with [11C](R)-rolipram and [11C]PBR28

The aim of this study was to test seven previously published image-input methods in state-of-the-art high resolution PET brain images. Images were obtained with a High Resolution Research Tomograph plus a resolution-recovery reconstruction algorithm using two different radioligands with different radiometabolite fractions. Three of the methods required arterial blood samples to scale the image-input, and four were blood-free methods. values was quantified using a scoring system. Using the image input methods that gave the most accurate results with Logan analysis, we also performed kinetic modelling with a two-tissue compartment model.)-rolipram, which has a lower metabolite fraction. Compartment modeling gave less reliable results, especially for the estimation of individual rate constants.C]PBR28), the more difficult it is to obtain a reliable image-derived input function; and 4) in association with image inputs, graphical analyses should be preferred over compartmental modelling

Automated Nuclear Analysis of Leishmania major Telomeric Clusters Reveals Changes in Their Organization during the Parasite's Life Cycle

Parasite virulence genes are usually associated with telomeres. The clustering of the telomeres, together with their particular spatial distribution in the nucleus of human parasites such as Plasmodium falciparum and Trypanosoma brucei, has been suggested to play a role in facilitating ectopic recombination and in the emergence of new antigenic variants. Leishmania parasites, as well as other trypanosomes, have unusual gene expression characteristics, such as polycistronic and constitutive transcription of protein-coding genes. Leishmania subtelomeric regions are even more unique because unlike these regions in other trypanosomes they are devoid of virulence genes. Given these peculiarities of Leishmania, we sought to investigate how telomeres are organized in the nucleus of Leishmania major parasites at both the human and insect stages of their life cycle. We developed a new automated and precise method for identifying telomere position in the three-dimensional space of the nucleus, and we found that the telomeres are organized in clusters present in similar numbers in both the human and insect stages. While the number of clusters remained the same, their distribution differed between the two stages. The telomeric clusters were found more concentrated near the center of the nucleus in the human stage than in the insect stage suggesting reorganization during the parasite's differentiation process between the two hosts. These data provide the first 3D analysis of Leishmania telomere organization. The possible biological implications of these findings are discussed

Obesity prevalence from a European perspective: a systematic review

<p>Abstract</p> <p>Background</p> <p>Obesity has been recognised as an important contributing factor in the development of various diseases, but comparative data on this condition are limited. We therefore aimed to identify and discuss current epidemiological data on the prevalence of obesity in European countries.</p> <p>Methods</p> <p>We identified relevant published studies by means of a MEDLINE search (1990–2008) supplemented by information obtained from regulatory agencies. We only included surveys that used direct measures of weight and height and were representative of each country's overall population.</p> <p>Results</p> <p>In Europe, the prevalence of obesity (body mass index ≥ 30 kg/m²) in men ranged from 4.0% to 28.3% and in women from 6.2% to 36.5%. We observed considerable geographic variation, with prevalence rates in Central, Eastern, and Southern Europe being higher than those in Western and Northern Europe.</p> <p>Conclusion</p> <p>In Europe, obesity has reached epidemic proportions. The data presented in our review emphasise the need for effective therapeutic and preventive strategies.</p

3D Fluorescent Spots Detection in Line-Scanning Confocal Microscopy

International audienc

Kompetenzorientiertes Lernen im ambulanten Kontext. Implementierung der Lehrveranstaltung "Ambulanzsimulation" in das Quartal Ambulante Medizin des Mannheimer Modellstudiengangs MaReCuM

Aim: As part of the MaReCuM model curriculum at Medical Faculty Mannheim Heidelberg University, a final year rotation in ambulatory care was implemented and augmented to include ambulatory care simulation. In this paper we describe this ambulatory care simulation, the designated competency-based learning objectives, and evaluate the educational effect of the ambulatory care simulation training.Method: Seventy-five final year medical students participated in the survey (response rate: 83%). The control group completed the ambulatory rotation prior to the implementation of the ambulatory care simulation. The experimental group was required to participate in the simulation at the beginning of the final year rotation in ambulatory care. A survey of both groups was conducted at the beginning and at the end of the rotation. The learning objectives were taken from the National Competency-based Catalogue of Learning Objectives for Undergraduate Medical Education (NKLM).Results: The ambulatory care simulation had no measurable influence on students' subjectively perceived learning progress, the evaluation of the ambulatory care rotation, or working in an ambulatory care setting. At the end of the rotation participants in both groups reported having gained better insight into treating outpatients. At the beginning of the rotation members of both groups assessed their competencies to be at the same level. The simulated ambulatory scenarios were evaluated by the participating students as being well structured and easy to understand. The scenarios successfully created a sense of time pressure for those confronted with them. The ability to correctly fill out a narcotic prescription form as required was rated significantly higher by those who participated in the simulation. Participation in the ambulatory care simulation had no effect on the other competencies covered by the survey.Discussion: The effect of the four instructional units comprising the ambulatory care simulation was not measurable due to the current form or the measurement point at the end of the 12-week rotation. The reasons for this could be the many and statistically elusive factors relevant to the individual and the wide variety among final year rotation placements, the late point in time of the final survey, and the selection of simulated scenarios. The course is slated to undergo specific further development and should be supplemented with additional learning opportunities to ensure that the main learning objectives are covered. The description of the teaching format is meant to contribute to the ongoing development of medical education with an emphasis on competency in the areas of ambulatory care, communication, prevention and health promotion.Zielsetzung: Im Rahmen des Modellstudiengangs MaReCuM der Medizinischen Fakultät Mannheim der Universität Heidelberg wurde das PJ-Quartal Ambulante Medizin implementiert und um die Lehrveranstaltung "Ambulanzsimulation" erweitert. Die Ziele der Arbeit umfassen die Beschreibung der Lehrveranstaltung und der formulierten kompetenzbasierten Lernziele sowie die Untersuchung des Lerneffekts der Lehrveranstaltung.Methodik: 75 PJ-Studierende haben sich an der Fragebogenerhebung beteiligt (Rücklauf: 83%). Die Kontrollgruppe absolvierte das Quartal Ambulante Medizin vor Einführung der Lehrveranstaltung "Ambulanzsimulation". Die Versuchsgruppe nahm verpflichtend an dieser Lehrveranstaltung zu Beginn des PJ-Quartals Ambulante Medizin teil. In beiden Gruppen erfolgte jeweils am ersten Tag des Quartals sowie 21 Tage vor Ende des Quartals eine Fragebogenerhebung. Die Lernziele wurden dem NKLM entnommen.Ergebnisse: Die "Ambulanzsimulation" hatte keinen messbaren Einfluss auf den subjektiv wahrgenommenen Lernerfolg, die Bewertung des Quartals Ambulante Medizin sowie das Arbeiten in einem ambulanten Setting. Die Teilnehmer beider Gruppen gaben am Ende des Quartals an, einen besseren Einblick in die Behandlung ambulanter Patienten gewonnen zu haben. Die Teilnehmer beider Gruppen schätzten die untersuchten Kompetenzen zu Beginn des Quartals gleich ein. Die simulierten Patientenfälle wurden durch die Teilnehmer als eher gut strukturiert und leicht verständlich bewertet. Die Szenarien waren geeignet, beim Bearbeiten Zeitdruck entstehen zu lassen. Die Kompetenz, ein BTM-Rezept den formalen Vorgaben entsprechend korrekt auszufüllen, schätzten die Teilnehmer der "Ambulanzsimulation" signifikant besser ein. Auf die übrigen erhobenen Kompetenzen hatte die Teilnahme an der Ambulanzsimulation keinen Effekt.Diskussion: Der Effekt der nur 4 Unterrichtseinheiten umfassenden Lehrveranstaltung "Ambulanzsimulation" war in der untersuchten Form und am Ende des 12-wöchigen Quartals nicht messbar. Gründe dafür könnten die vielfältigen und statistisch nicht zu kontrollierenden Einflussfaktoren im Bereich der individuellen und sehr unterschiedlichen PJ-Rotationsplätze, der späte Zeitpunkt der Abschlusserhebung sowie die Auswahl der Simulationsszenarien sein. Die Lehrveranstaltung sollte spezifisch weiterentwickelt und möglicherweise um weitere Lerngelegenheiten ergänzt werden, um rotationsplatzübergreifend die Vermittlung der übergeordneten Lernziele sicher zu stellen. Die Beschreibung des Lehrformats versteht sich weiterhin als Diskussionsbeitrag im Rahmen der Weiterentwicklung des Medizinstudiums mit einer Stärkung der Kompetenzen im Bereich der ambulanten Patientenversorgung, der Kommunikation, der Prävention und Gesundheitsförderung

Three-dimensional point spread function model for line-scanning confocal microscope with high-aperture objective

International audienc