The impact of curricular change on medical students' knowledge of anatomy

Background: In recent years, following the publication of Tomorrow's Doctors, the undergraduate medical curriculum in most UK medical schools has undergone major revision. This has resulted in a significant reduction in the time allocated to the teaching of the basic medical sciences, including anatomy. However, it is not clear what impact these changes have had on medical students' knowledge of surface anatomy. Aim: This study aimed to assess the impact of these curricular changes on medical students' knowledge of surface anatomy. Setting: Medical student intakes for 1995-98 at the Queen's University of Belfast, UK. Methods: The students were invited to complete a simple examination paper testing their knowledge of surface anatomy. Results from the student intake of 1995, which undertook a traditional, 'old' curriculum, were compared with those from the student intakes of 1996-98, which undertook a new, 'systems-based' curriculum. To enhance linear response and enable the use of linear models for analysis, all data were adjusted using probit transformations of the proportion (percentage) of correct answers for each item and each year group. Results: The student intake of 1995 (old curriculum) were more likely to score higher than the students who undertook the new, systems-based curriculum. Conclusion: The introduction of the new, systems-based course has had a negative impact on medical students' knowledge of surface anatomy.

Terminal nerve-derived neuropeptide Y modulates physiological responses in the olfactory epithelium of hungry axolotls (Ambystoma mexicanum).

The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the olfactory epithelium, displays anatomical and neurochemical characteristics that suggest that it modulates activity in the olfactory epithelium. Using immunocytochemical techniques, we demonstrate that neuropeptide Y (NPY) is abundantly present in the terminal nerve in the axolotl (Ambystoma mexicanum), an aquatic salamander. Because NPY plays an important role in regulating appetite and hunger in many vertebrates, we investigated the possibility that NPY modulates activity in the olfactory epithelium in relation to the animal's hunger level. We therefore characterized the full-length NPY gene from axolotls to enable synthesis of authentic axolotl NPY for use in electrophysiological experiments. We find that axolotl NPY modulates olfactory epithelial responses evoked by L-glutamic acid, a food-related odorant, but only in hungry animals. Similarly, whole-cell patch-clamp recordings demonstrate that bath application of axolotl NPY enhances the magnitude of a tetrodotoxin-sensitive inward current, but only in hungry animals. These results suggest that expression or activity of NPY receptors in the olfactory epithelium may change with hunger level, and that terminal nerve-derived peptides modulate activity in the olfactory epithelium in response to an animal's changing behavioral and physiological circumstances.

Gross anatomy of the muscle systems and associated innervation of Apatemon cobitidis proterorhini metacercaria (Trematoda: Strigeidea), as visualized by confocal microscopy.:Strigeidea), as visualized by confocal microscopy

The major muscle systems of the metacercaria of the strigeid trematode, Apatemon cobitidis proterorhini have been examined using phalloidin as a site-specific probe for filamentous actin. Regional differences were evident in the organization of the body wall musculature of the forebody and hindbody, the former comprising outer circular, intermediate longitudinal and inner diagonal fibres, the latter having the inner diagonal fibres replaced with an extra layer of more widely spaced circular muscle. Three orientations of muscle fibres (equatorial, meridional, radial) were discernible in the oral sucker, acetabulum and paired lappets. Large longitudinal extensor and flexor muscles project into the hindbody where they connect to the body wall or end blindly. Innervation to the muscle systems of Apatemon was examined by immunocytochemistry, using antibodies to known myoactive substances: the flatworm FMRFamide-related neuropeptide (FaRP), GYIRFamide, and the biogenic amine, 5-hydroxytryptamine (5-HT). Strong immunostaining for both peptidergic and serotoninergic components was found in the central nervous system and confocal microscopic mapping of the distribution of these neuroactive substances revealed they occupied separate neuronal pathways. In the peripheral nervous system, GYIRFamide-immunoreactivity was extensive and, in particular, associated with the innervation of all attachment structures; serotoninergic fibres, on the other hand, were localized to the oral sucker and pharynx and to regions along the anterior margins of the forebody.

Flatworm nerve-muscle: structural and functional analysis

Platyhelminthes occupy a unique position in nerve-muscle evolution, being the most primitive of metazoan phyla. Essentially, their nervous system consists of an archaic brain and associated pairs of longitudinal nerve cords cross-linked as an orthogon by transverse commissures. Confocal imaging reveals that these central nervous system elements are in continuity with an array of peripheral nerve plexuses which innervate a well-differentiated grid work of somatic muscle as well as a complexity of myofibres associated with organs of attachment, feeding, and reproduction. Electrophysiological studies of flatworm muscles have exposed a diversity of voltage-activated ion channels that influence muscle contractile events. Neuronal cell types are mainly multi- and bi-polar and highly secretory in nature, producing a heterogeneity of vesicular inclusions whose contents have been identified cytochemically to include all three major types of cholinergic, aminergic, and peptidergic messenger molecules. A landmark discovery in flatworm neurobiology was the biochemical isolation and amino acid sequencing of two groups of native neuropeptides: neuropeptide F and FMRFamide-related peptides (FaRPs). Both families of neuropeptide are abundant and broadly distributed in platyhelminths, occurring in neuronal vesicles in representatives of all major flatworm taxa. Dual localization studies have revealed that peptidergic and cholinergic substances occupy neuronal sets separate from those of serotoninergic components. The physiological actions of neuronal messengers in flatworms are beginning to be established, and where examined, FaRPs and 5-HT are myoexcitatory, while cholinomimetic substances are generally inhibitory. There is immunocytochemical evidence that FaRPs and 5-HT have a regulatory role in the mechanism of egg assembly. Use of muscle strips and (or) muscle fibres from free-living and parasitic flatworms has provided baseline information to indicate that muscle responses to FaRPs are mediated by a G-protein-coupled receptor, and that the signal transduction pathway for contraction involves the second messengers cAMP and protein kinase C.

An unusual delayed complication of inferior alveolar nerve block

Systemic and localised complications after administration of local anaesthetic for dental procedures are well recognised. We present two cases of patients with trismus and sensory deficit that arose during resolution of trismus as a delayed complication of inferior alveolar nerve block.

Order without law? An anatomy of Hamas security: The Executive Force (Tanfithya)

In the struggle to assert and consolidate its power, the Hamas movement of the Palestinian territories has devised several strategies for control. In recognition that control of security remains a key goal for any power-seeker, following its election victory in January 2006, Hamas entered into a fierce and ultimately successful conflict with Fatah for control of the Palestinian Authority Ministry of Interior and Palestinian Security Forces (PSF) in the Gaza Strip. One way in which Hamas was able to achieve this objective was through the creation of its own internal ‘police’ force called the Tanfithya (Executive Force or EF). This article details an anatomy of the EF and the implications of this force in terms of Hamas' confrontation with opponents and its attempts at governance. It also examines the extent to which the EF can be considered to be a model of Islamic policing and its impact on secular rivals in the Gaza Strip.