Interprofessional and problem-based learning: A marriage made in heaven?

This paper explores interprofessional learning (IPL) and whether it would profit from a more systematic merger with problem-based learning (PBL). IPL is based on the idea of bringing together knowledge from the different health professions as they interact with each other for better health care. PBL springs from the idea of bringing learning closer to the application of knowledge in every day life. It has been widely adopted as an interprofessional learning method, for example at Linkøping in Sweden.     

Synapsin- and actin-dependent frequency enhancement in mouse hippocampal mossy fiber synapses

The synapsin proteins have different roles in excitatory and inhibitory synaptic terminals. We demonstrate a differential role between types of excitatory terminals. Structural and functional aspects of the hippocampal mossy fiber (MF) synapses were studied in wild-type (WT) mice and in synapsin double-knockout mice (DKO). A severe reduction in the number of synaptic vesicles situated more than 100 nm away from the presynaptic membrane active zone was found in the synapsin DKO animals. The ultrastructural level gave concomitant reduction in F-actin immunoreactivity observed at the periactive endocytic zone of the MF terminals. Frequency facilitation was normal in synapsin DKO mice at low firing rates (approximately 0.1 Hz) but was impaired at firing rates within the physiological range (approximately 2 Hz). Synapses made by associational/commissural fibers showed comparatively small frequency facilitation at the same frequencies. Synapsin-dependent facilitation in MF synapses of WT mice was attenuated by blocking F-actin polymerization with cytochalasin B in hippocampal slices. Synapsin III, selectively seen in MF synapses, is enriched specifically in the area adjacent to the synaptic cleft. This may underlie the ability of synapsin III to promote synaptic depression, contributing to the reduced frequency facilitation observed in the absence of synapsins I and II.     

Regulation of synaptic vesicle recycling by complex formation between intersectin 1 and the clathrin adaptor complex AP2

Clathrin-mediated synaptic vesicle (SV) recycling involves the spatiotemporally controlled assembly of clathrin coat components at phosphatidylinositiol (4, 5)-bisphosphate [PI(4,5)P₂]-enriched membrane sites within the periactive zone. Such spatiotemporal control is needed to coordinate SV cargo sorting with clathrin/AP2 recruitment and to restrain membrane fission and synaptojanin-mediated uncoating until membrane deformation and clathrin coat assembly are completed. The molecular events underlying these control mechanisms are unknown. Here we show that the endocytic SH3 domain-containing accessory protein intersectin 1 scaffolds the endocytic process by directly associating with the clathrin adaptor AP2. Acute perturbation of the intersectin 1-AP2 interaction in lamprey synapses in situ inhibits the onset of SV recycling. Structurally, complex formation can be attributed to the direct association of hydrophobic peptides within the intersectin 1 SH3A-B linker region with the “side sites” of the AP2 α- and β-appendage domains. AP2 appendage association of the SH3A-B linker region inhibits binding of the inositol phosphatase synaptojanin 1 to intersectin 1. These data identify the intersectin-AP2 complex as an important regulator of clathrin-mediated SV recycling in synapses.     

Causes of death among patients with myasthenia gravis in Norway between 1951 and 2001

OBJECTIVE: This study investigated the causes of death among patients with myasthenia gravis (MG), with emphasis on respiratory tract and cardiac disease. METHODS: The Norwegian Cause of Death Register contains information on all deaths among Norwegian citizens. In total, 249 deceased patients with MG were identified (1951-2001). These were compared with 1245 controls deceased in the same period and matched for sex and year of birth. RESULTS: The death certificates of patients with MG had a significantly higher occurrence of respiratory tract disease as cause of death than controls (28.1% v 20.9%, p = 0.012). The difference was most pronounced for male patients, for patients dying between 30 and 69 years of age, and for deaths occurring before 1996. For cardiac disease there was a significantly lower occurrence among patients with MG than among controls at 50-69 years of age, for both men (19.4% v 52.0%, p = 0.001) and women (14.6% v 29.6%, p = 0.036). Age and year of death were important determinants for the causes of death, but could not account for the differences between the patients with MG and controls. CONCLUSIONS: This study shows that patients with MG dying between 1951 and 1995 had a higher occurrence of respiratory tract disease listed as cause of death than had a matched control group. The lack of difference after 1995 probably reflects improved treatment of MG and its complications. The reduced occurrence of cardiac disease among patients with MG is probably explained by competing factors (respiratory tract disease) causing death.     

Central nervous reactions to a 6.5-hour altitude exposure at 3048 meters

In this study of CNS reactions to mild hypoxia, 7 subjects were decompressed to the equivalence of 3048 m altitude breathing air, for 6.5 h. On reaching 3048 m, and for every second h thereafter, a battery of neuropsychological tests were administered. In addition, blood and performance measures were sampled and a symptom check list was administered. The performance tests indicated significant effects of hypoxia. In contrast to earlier studies on grade of hypoxia and performance, no relationship between impaired performance and duration of exposure to hypoxia was found. Repeated testing throughout exposure indicated stable individual reactions. Endocrine variables did not support the hypothesis that activation or 'stress' caused the impairment observed. In addition to impaired neuropsychological test performance and impaired task performance, the subjects reported headache, weakness and some dizziness. Comparisons between different tests confirmed previous results showing that mild hypoxia yields varying degrees of impairment on different cognitive functions.     

Formation of geometrically complex lipid nanotube-vesicle networks of higher-order topologies

We present a microelectrofusion method for construction of fluid-state lipid bilayer networks of high geometrical complexity up to fully connected networks with genus = 3 topology. Within networks, self-organizing branching nanotube architectures could be produced where intersections spontaneously arrange themselves into three-way junctions with an angle of 120 degrees between each nanotube. Formation of branching nanotube networks appears to follow a minimum-bending energy algorithm that solves for pathway minimization. It is also demonstrated that materials can be injected into specific containers within a network by nanotube-mediated transport of satellite vesicles having defined contents. Using a combination of microelectrofusion, spontaneous nanotube pattern formation, and satellite-vesicle injection, complex networks of containers and nanotubes can be produced for a range of applications in, for example, nanofluidics and artificial cell design. In addition, this electrofusion method allows integration of biological cells into lipid nanotube-vesicle networks.