Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Projection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,225 records · Page 68Linked to original sources
PubMed1995

Audit activity and quality of completed audit projects in primary care in Staffordshire.

OBJECTIVES: To survey audit activity in primary care and determine which practice factors are associated with completed audit; to survey the quality of completed audit projects. DESIGN: From April 1992 to June 1993 a team from the medical audit advisory group visited all general practices; a research assistant visited each practice to study the best audit project. Data were collected in structured interviews. SETTING: Staffordshire, United Kingdom. SUBJECTS: All 189 general practices. MAIN MEASURES: Audit activity using Oxford classification system. Quality of best audit project by assessing choice of topic; participation of practice staff; setting of standards; methods of data collection and presentation of results; whether a plan to make changes resulted from the audit; and whether changes led to the set standards being achieved. RESULTS: Audit information was available from 169 practices (89%). 44(26%) practices had carried out at least one full audit; 40(24%) had not started audit. Mean scores with the Oxford classification system were significantly higher with the presence of a practice manager (2.7(95% confidence interval 2.4 to 2.9) v 1.2(0.7 to 1.8), p < 0.0001) and with computerisation (2.8(2.5 to 3.1) v 1.4 (0.9 to 2.0), p < 0.0001), organised notes (2.6(2.1 to 3.0) v 1.7(7.2 to 2.2), p = 0.03), being a training practice (3.5(3.2 to 3.8) v 2.1(1.8 to 2.4), p < 0.0001), and being a partnership (2.8(2.6 to 3.0) v 1.5(1.1 to 2.0), p < 0.0001). Standards had been set in 62 of the 71 projects reviewed. Data were collected prospectively in 36 projects and retrospectively in 35. 16 projects entailed taking samples from a study population and 55 from the whole population. 50 projects had a written summary. Performance was less than the standards set or expected in 56 projects. 62 practices made changes as a result of the audit. 35 of the 53 that had reviewed the changes found that the original standards had been reached. CONCLUSIONS: Evaluation of audit in primary care should include evaluation of the methods used, whether deficiencies were identified, and whether changes were implemented to resolve any problems found.

Data Collection↗
PubMed1996

Sliding thin slab, minimum intensity projection technique in the diagnosis of emphysema: histopathologic-CT correlation.

PURPOSE: To assess the accuracy of sliding thin slab, minimum intensity projection technique in the detection of emphysema. MATERIALS AND METHODS: In 29 patients without radiographic evidence of emphysema and who were undergoing lung resection, focal spiral computed tomography (CT) was performed in the lobe to be resected. Ten contiguous 1-mm-thick CT scans and sliding thin slab, minimum intensity projection images with slab thicknesses of 3-, 5-, and 8 mm were generated. From each image, the presence and extent of emphysema were recorded before histopathologic analysis was performed. To familiarize readers with the appearance of normal lung parenchyma on sliding thin slab, minimum intensity projection images, five asymptomatic volunteers underwent scanning with a similar protocol. RESULTS: Emphysema was present on both thin-section CT scans and sliding thin slab, minimum intensity projection images in 13 patients. In all cases, sliding thin slab, minimum intensity projection images improved conspicuity of small areas of hypoattenuation. When thin-section CT scans were negative (n = 16), sliding thin slab, minimum intensity projection images enabled identification of focal zones of hypoattenuation in four cases with histologic confirmation of emphysema. Sensitivity of thin-section CT (62%) and sliding thin slab, minimum intensity projection technique (81%) were significantly different (P < .01); specificity for both was 100%. Emphysema was easier to detect on 8-mm-thick slabs because of better suppression of vascular structures. CONCLUSION: The sliding thin slab, minimum intensity projection technique enabled improved detection of mild forms of emphysema.

Adult↗
PubMed1998

Interdependence of spatial properties and projection patterns of medial vestibulospinal tract neurons in the cat.

Activity of vestibular nucleus neurons with axons in the ipsi- or contralateral medial vestibulospinal tract was studied in decerebrate cats during sinusoidal, whole-body rotations in many planes in three-dimensional space. Antidromic activation of axon collaterals distinguished between neurons projecting only to neck segments from those with collaterals to C6 and/or oculomotor nucleus. Secondary neurons were identified by monosynaptic activation after labyrinth stimulation. A three-dimensional maximum activation direction vector (MAD) summarized the spatial properties of 151 of 169 neurons. The majority of secondary neurons (71%) terminated above the C6 segment. Of these, 43% had ascending collaterals to the oculomotor nucleus (VOC neurons), and 57% did not (VC neurons). The majority of VOC and VC neurons projected contralaterally and ipsilaterally, respectively. Most C6-projecting neurons could not be activated from oculomotor nucleus (V-C6 neurons) and projected primarily ipsilaterally. All VO-C6 neurons projected contralaterally. The distributions of MADs for secondary neurons with different projection patterns were different. Most VOC (84%) and contralaterally projecting VC (91%) neurons had MADs close to the activation vector of a semicircular canal pair, compared with 54% of ipsilaterally projecting VC (i-VC) and 39% of V-C6 neurons. Many i-VC (44%) and V-C6 (48%) neurons had responses suggesting convergent input from horizontal and vertical canal pairs. Horizontal and vertical gains were comparable for some, making it difficult to assign a primary canal input. MADs consistent with vertical-vertical canal pair convergence were less common. Type II yaw or type II roll responses were seen for 22% of the i-VC neurons, 68% of the V-C6 neurons, and no VOC cells. VO-C6 neurons had spatial properties between those of VOC and V-C6 neurons. These results suggest that secondary VOC neurons convey semicircular canal pair signals to both ocular and neck motor centers, perhaps linking eye and head movements. Secondary VC and V-C6 neurons carry more processed signals, possibly to drive neck and forelimb reflexes more selectively. Two groups of secondary i-VC neurons exhibited vertical-horizontal canal convergence similar to that present on neck muscles. The vertical-vertical canal convergence present on many neck muscles, however, was not present on medial vestibulospinal neurons. Spatial transformations achieved by the vestibulocollic reflex may occur in part on secondary neurons but further combination of canal signals must take place to generate compensatory muscle activity.

Animals↗
PubMed2002

Inhibitory interactions between spiny projection neurons in the rat striatum.

The spiny projection neurons are by far the most numerous type of striatal neuron. In addition to being the principal projection neurons of the striatum, the spiny projection neurons also have an extensive network of local axon collaterals by which they make synaptic connections with other striatal projection neurons. However, up to now there has been no direct physiological evidence for functional inhibitory interactions between spiny projection neurons. Here we present new evidence that striatal projection neurons are interconnected by functional inhibitory synapses. To examine the physiological properties of unitary inhibitory postsynaptic potentials (IPSPs), dual intracellular recordings were made from pairs of spiny projection neurons in brain slices of adult rat striatum. Synaptic interactions were found in 9 of 45 pairs of neurons using averages of 200 traces that were triggered by a single presynaptic action potential. In all cases, synaptic interactions were unidirectional, and no bidirectional interactions were detected. Unitary IPSPs evoked by a single presynaptic action potential had a peak amplitude ranging from 157 to 319 microV in different connections (mean: 277 +/- 46 microV, n = 9). The percentage of failures of single action potentials to evoke a unitary IPSP was estimated and ranged from 9 to 63% (mean: 38 +/- 14%, n = 9). Unitary IPSPs were reversibly blocked by bicuculline (n = 4) and had a reversal potential of -62.4 +/- 0.7 mV (n = 5), consistent with GABA-mediated inhibition. The findings of the present study correlate very well with anatomical evidence for local synaptic connectivity between spiny projection neurons and suggest that lateral inhibition plays a significant role in the information processing operations of the striatum.

Animals↗
PubMed1994

Brainstem reticular nuclei that project to the thalamus in rats: a retrograde tracer study.

The precise nuclear origins of projections from the brainstem reticular formation to the thalamus were identified in rats using two retrograde tracing substances: wheat germ agglutinin-horseradish peroxidase conjugate, and Fluoro-Gold. Injections of these tracers were made into a variety of thalamic nuclei, including the intralaminar nuclei (most of these also involved the lateral part of the mediodorsal nucleus), the central part of the mediodorsal nucleus, the ventrolateral/ventromedial nuclei, and the ventral posterolateral/ventral posteromedial nuclei. Counts of retrogradely labeled cells were done on a large sample of select cases. The data generated by these cell counts indicate that brainstem reticular projections to the intralaminar/lateral mediodorsal complex are fairly strong, as are those to the ventrolateral/ventromedial nuclear complex. Ascending reticular projections to the mediodorsal nucleus per se are somewhat weaker, while those to the ventrobasal complex (or at least the ventral posterolateral nucleus) are weaker still. As a whole, reticular neurons projecting to the thalamus are by far most numerous in the midbrain, and then decline gradually at successively caudal levels through the pons and medulla. Midbrain reticular groups evincing very strong ascending projections include nucleus reticularis (n.r.) pedunculopontinus (particularly its pars compactus), n.r. cuneiformis and n.r. subcuneiformis (together known as the deep mesencephalic nucleus). Strong thalamic projections arise from the medial part of n.r. pontis oralis, the medial (beta) part of n.r. pontis caudalis, and the mid-pontine dorsomedial tegmental area. Within the medullary reticular formation, a 'trans-nuclear field' of neurons encompassing n.r. paragigantocellularis dorsalis and dorsal parts of n.r. gigantocellularis and n.r. parvocellularis was consistently labeled contralateral to the injection site. In general, ascending reticulothalamic projections are largely ipsilateral from midbrain reticular groups, bilateral from pontine reticular groups, and contralateral from medullary reticular groups. Within individual reticular nuclei, the morphology of labeled neurons is identical to that reported previously by this laboratory subsequent to spinal, cortical, or cerebellar tracer injections, thus strengthening our hypothesis that the various brainstem reticular nuclei can be distinguished on the basis of neuronal morphology. As a whole, thalamic-projecting reticular neurons are mostly small or medium-sized cells.

Animals↗
PubMed1992

Wulst efferents in the little owl Athene noctua: an investigation of projections to the optic tectum.

The efferent projections from the Wulst were studied in the little owl, Athene noctua, using anterograde migration of wheat-germ-agglutinin conjugated horseradish peroxidase (WGA-HRP). Wulst projections were distributed to telencephalic, diencephalic and mesencephalic targets in a general pattern similar to that previously described in other avian species. Our results on the organization of the Wulst-optic tectum pathway in the little owl reveal well defined and laminarly arranged terminal projections into the superficial tectal layers, with a distribution suggestive of topographical relationships between neurons of origin in the Wulst and termination fields in the optic tectum. In contrast to lateral-eyed birds, the little owl possesses conspicuous contralateral projections to the optic tectum. Ipsilateral and contralateral efferents are restricted to different tectal regions, i.e. ipsilateral projections to the caudo-dorsal and contralateral projections to the rostro-ventral optic tectum. In addition, the anterior and posterior Wulst differentially contribute to the ipsilateral and contralateral projections to the optic tectum. This differential organization of Wulst efferents, as well as the presence of substantial contralateral projections, might be related to the high degree of binocular overlap typical of frontal-eyed birds. At a functional level, electric potentials recorded in the optic tectum and evoked by visual stimulation showed that information from one eye can reach the ipsilateral optic tectum. After Wulst ablation, the amplitude of these potentials was significantly reduced, indicating that Wulst efferents may influence visually-evoked activity in the optic tectum.

Animals↗
PubMed1993

Topographic organization of the corticonuclear projections from the paraflocculus in the albino rat: an autoradiographic orthograde tracing study.

The topographic organization of corticonuclear projections from the paraflocculus was studied in rats by an autoradiographic orthograde tracing method. The corticonuclear fibers from the paraflocculus terminated primarily in the caudoventral part of the lateral cerebellar nucleus and in the lateral part of the posterior interpositus nucleus. The rostrolateral part of the ventral paraflocculus projected only to the lateral nucleus, and the caudomedial part projected only to the posterior interpositus nucleus. Although differential projections from the dorsal and ventral paraflocculi were not clearly observed, the dorsal paraflocculus appeared to project to slightly more dorsal parts of the lateral and posterior interpositus nuclei than did the ventral paraflocculus. The lateral, medial, rostral, and caudal parts of each sublobule tended to project to the ventral, dorsal, rostral, and caudal regions within the caudoventral part of the lateral nucleus, respectively, despite massive overlap in the individual terminal fields. The corticonuclear projection from the dorsal and ventral paraflocculi to the posterior interpositus nucleus were organized in different directions; those from the dorsal paraflocculus were organized rostrocaudally, while those from the ventral paraflocculus were organized mediolaterally. These results suggest that in rats the corticonuclear projections from the paraflocculus are topographically organized in the mediolateral and rostrocaudal directions as well as in the dorsoventral direction.

Animals↗
PubMed1988

Projections of the vestibular and cerebellar nuclei in Rana pipiens.

The efferent projections and cytoarchitecture of the vestibulocerebellar region were examined to determine the nuclear boundaries and potential homologies. The anterior portion of the vestibular complex projects to the ipsilateral oculomotor and trochlear nuclei and is the major source of commissural fibers. Neurons in the rostromedial portions of the complex project to the contralateral trochlear nucleus. Large neurons in the ventrolateral portion of the complex give rise to a bilateral vestibulospinal pathway. Medium-sized neurons in the neuropil and small neurons in the central gray giving rise to bilateral projections to the spinal cord and oculomotor nuclei as well as commissural and ipsilateral cerebellar efferents. Projections from the nucleus of the cerebellum reach the contralateral spinal cord and cerebellar nucleus and there is also a bilateral projection to the ventral rhombencephalic and mesencephalic basal plates. The medial portion of the nucleus gives rise to commissural, ipsilateral mesencephalic and contralateral spinal projections. The lateral portion of the nucleus projects to the contralateral ventral mesencephalon. On the whole, the results of this investigation substantiate the division of the anuran vestibular complex in anurans into nuclei which may be homologous to the superior nucleus and nucleus of Deiters in mammals. The case for distinct descending and medial nuclei is less compelling. Further, it appears possible to divide the nucleus of the cerebellum into medial and lateral components whose connectivity is similar to that of reptiles and to a lesser extent mammals.

Animals↗
PubMed1987

Auditory pathways in the budgerigar. I. Thalamo-telencephalic projections.

Thalamo-telencephalic auditory pathways in the budgerigar (Melopsittacus undulatus) were studied using horseradish peroxidase (HRP) histochemistry and amino acids autoradiography. The results indicate that in this species the thalamic auditory relay nucleus, n. ovoidalis, projects upon a circumscribed region of the caudal and caudomedial neostriatum including field 'L' and immediately adjacent portions of the neostriatum intermedium, pars dorsolateralis (NIDL). This region of NIDL also receives inputs from another thalamic nucleus, n. dorsolateralis posterior (DLP). In the DLP is in receipt of tectal inputs. Projections of DLP upon NIDL were confirmed with amino acids autoradiography. The results of the HRP experiments indicate that different portions of n. ovoidalis project upon different portions of field 'L' and NIDL. Neurons in the dorsal and lateral portions of the n. ovoidalis project upon more medial portions of field 'L'. Neurons located centrally in the n. ovoidalis project upon central and lateral portions of field 'L'. Neurons in the ventromedial portion of the n. ovoidalis are labeled in all cases in which HRP is placed in either field 'L' or in the DLP projection field immediately adjacent to field 'L' proper. HRP injections placed in NIDL lateral to the projection fields of the n. ovoidalis and DLP label neurons within other diencephalic nuclei including the n. subrotundus. The caudal and intermediate levels of the neostriatum intermedium apparently serve as a complex processing area for many thalamic inputs in this species. The existence of multiple ascending thalamo-telencephalic projections from portions of the thalamus receiving inputs from both the visual (i.e., tectal) and auditory (i.e., n. mesencephalicus lateralis pars dorsalis) portions of the midbrain roof (i.e., from DLP and from n. ovoidalis) suggests the possibility that intermodal associations may take place in these telencephalic fields. Such partially converging pathways may provide a basics for intermodal associations which are important in individual recognition and social signalling systems in this species.

Animals↗
PubMed2005

An extrahippocampal projection from the dentate gyrus to the olfactory tubercle.

BACKGROUND: The dentate gyrus is well known for its mossy fiber projection to the hippocampal field 3 (CA3) and its extensive associational and commissural connections. The dentate gyrus, on the other hand, has only few projections to the CA1 and the subiculum, and none have clearly been shown to extrahippocampal target regions. RESULTS: Using anterograde and retrograde tracer techniques in the Madagascan lesser hedgehog tenrec (Afrosoricidae, Afrotheria) it was shown in this study that the dentate hilar region gave rise to a faint, but distinct, bilateral projection to the most rostromedial portion of the olfactory tubercle, particularly its molecular layer. Unlike the CA1 and the subiculum the dentate gyrus did not project to the accumbens nucleus. A control injection into the medial septum-diagonal band complex also retrogradely labeled cells in the dentate hilus, but these neurons were found immediately adjacent to the heavily labeled CA3, while the tracer injections into the rostromedial tubercle did not reveal any labeling in CA3. CONCLUSION: The dentate hilar neurons projecting to the olfactory tubercle cannot be considered displaced cells of CA3 but represent true dentato-tubercular projection neurons. This projection supplements the subiculo-tubercular projection. Both terminal fields overlap among one another as well as with the fiber terminations arising in the anteromedial frontal cortex. The rostromedial olfactory tubercle might represent a distinct ventral striatal target area worth investigating in studies of the parallel processing of cortico-limbic information in tenrec as well as in cat and monkey.

Animals↗
PubMed2002

The early topography of thalamocortical projections is shifted in Ebf1 and Dlx1/2 mutant mice.

The prevailing model to explain the formation of topographic projections in the nervous system stipulates that this process is governed by information located within the projecting and targeted structures. In mammals, different thalamic nuclei establish highly ordered projections with specific neocortical domains and the mechanisms controlling the initial topography of these projections remain to be characterized. To address this issue, we examined Ebf1(-/-) embryos in which a subset of thalamic axons does not reach the neocortex. We show that the projections that do form between thalamic nuclei and neocortical domains have a shifted topography, in the absence of regionalization defects in the thalamus or neocortex. This shift is first detected inside the basal ganglia, a structure on the path of thalamic axons, and which develops abnormally in Ebf1(-/-) embryos. A similar shift in the topography of thalamocortical axons inside the basal ganglia and neocortex was observed in Dlx1/2(-/-) embryos, which also have an abnormal basal ganglia development. Furthermore, Dlx1 and Dlx2 are not expressed in the dorsal thalamus or in cortical projections neurons. Thus, our study shows that: (1) different thalamic nuclei do not establish projections independently of each other; (2) a shift in thalamocortical topography can occur in the absence of major regionalization defects in the dorsal thalamus and neocortex; and (3) the basal ganglia may contain decision points for thalamic axons' pathfinding and topographic organization. These observations suggest that the topography of thalamocortical projections is not strictly determined by cues located within the neocortex and may be regulated by the relative positioning of thalamic axons inside the basal ganglia.

Animals↗
PubMed1994

Development of specific muscle and cutaneous sensory projections in cultured segments of spinal cord.

Development of sensory projections was studied in cultured spinal segments with attached dorsal root ganglia. In spinal segments from stage 30 (E6.5) and older chicken embryos, prelabeled muscle and cutaneous afferents established appropriate projections. Cutaneous afferents terminated solely within the dorsolateral laminae, whereas some muscle afferents (presumably Ia afferents) projected ventrally towards motoneurons. Development of appropriate projections suggests that sufficient cues are preserved in spinal segments to support the formation of modality-specific sensory projections. Further, because these projections developed in the absence of muscle or skin, these results show that the continued presence of peripheral targets is not required for the formation of specific central projections after stage 29 (E6.0). Development of the dorsal horn in cultured spinal segments was assessed using the dorsal midline as a marker. In ovo, this midline structure appears at stage 29. Lack of midline formation in stage 28 and 29 cultured spinal segments suggests that the development of the dorsal horn is arrested in this preparation. This is consistent with earlier reports suggesting that dorsal horn development may be dependent on factors outside the spinal cord. Because dorsal horn development is blocked in cultured spinal segments, this preparation makes it possible to study the consequences of premature ingrowth of sensory axons into the spinal cord. In chicken embryos sensory afferents reach the spinal cord at stage 25 (E4.5) but do not arborize within the gray matter until stage 30. During this period dorsal horn cells are still being generated. In spinal segments, only those segments that have developed a midline at the time of culture support the formation of midline at the time of culture support the formation of specific sensory projections.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

The ganglionic origins and central projections of primary sensory neurons innervating the upper and lower lips in the rat.

Retrograde and transganglionic transport of horseradish peroxidase (HRP) was used to investigate the neurons innervating the upper and the lower lips and their central projections in the rat. Both the upper and the lower lips were observed to be innervated by a very large number of trigeminal sensory neurons, with their cell bodies located in the maxillary and the mandibular parts of the trigeminal ganglion, respectively. The central projections of neurons innervating the upper lip formed a long continuous column starting rostrally at midlevels of the trigeminal main sensory nucleus (5P) and extending caudally through the C1 dorsal horn, with occasional fibers reaching the C3 segment. The heaviest projections appeared in the middle portions of 5P and nucleus interpolaris (5I), as well as in the rostral part of nucleus caudalis (5C). A small but consistent projection to the solitary tract nucleus, originating from cells in the inferior vagal ganglion, was observed in the upper-lip experiments. The central projections from neurons innervating the lower lip also appeared as a long column located dorsally or dorsomedially to the projections from the upper lip. The most prominent projections from the lower lip were located in the caudal part of 5P, the middle part of 5I, and the caudal two-thirds of 5C. Sparse projections could be traced as far caudally as C4. At 5C and cervical levels, some labeling appeared contralaterally in the same location as on the ipsilateral side.

Animals↗
PubMedDate not supplied

Occupations and well-being: a study of personal projects.

OBJECTIVE: The purpose of this study was to explore the relationship between occupation and subjective well-being (SWB). METHOD: A convenience sample of 120 adults completed a personal projects analysis, a method of rating their current goal-directed pursuits. They also completed measures of SWB (Affect Balance Scale, Life Satisfaction Index Form A) and personality traits (Myers-Briggs Personality Inventory). Characteristics of personal projects were correlated with SWB scores. Multiple regression analysis was used to investigate possible predictors of well-being from among the characteristics of personal projects, personality traits, and demographic variables. RESULTS: The stress associated with personal projects was significantly and inversely correlated with well-being, as was project difficulty. Perceived progress in completing projects was significantly positively correlated with well-being. The strongest predictors for well-being were the composite project factors of stress and efficacy. Two personality traits, sensing and extraversion, interacted with the project dimension of stress to emerge as significant predictors of well-being. Together, these four variables explained 42% of the variance in well-being scores. CONCLUSION: These findings are consistent with assumptions that attributes of meaningful occupations are significantly related to people's perceived well-being.

Adult↗
PubMed2002

The projections of early enteric neurons are influenced by the direction of neural crest cell migration.

The enteric nervous system arises from the neural crest. In embryonic mice, vagal neural crest cells enter the developing foregut at approximately embryonic day 9.5 (E9.5) and then migrate rostrocaudally to colonize the entire gastrointestinal tract by E14.5. This study showed that a subpopulation of vagal crest-derived cells, very close to the migratory wavefront, starts to differentiate into neurons early, as shown by the expression of neuron-specific proteins and the absence of Sox10. Many of the early differentiating neurons transiently exhibited tyrosine hydroxylase (TH) immunoreactivity. The TH cells were demonstrated to be the progenitors of nitric oxide synthase (NOS) neurons. Immunohistochemistry, lesions, and DiI tracing were used to examine the projections of developing enteric neurons. The axons of first neurons in the gut (the TH-NOS neurons) projected in the same direction (caudally), and traversed the same pathways through the mesenchyme, as the migrating, undifferentiated, vagal crest-derived cells. To examine if the direction of migration and direction of axon projection are linked, coculture experiments were set up in which vagal crest-derived cells migrated either rostrocaudally (as they do in vivo), or caudorostrally (which they do not normally do), to colonize explants of embryonic aneural hindgut. The direction in which neurons projected was correlated with the direction of cell migration, but migration direction appears to be not the only mechanism influencing axon projection. Peristaltic reflexes involve both orally (rostrally) projecting neurons and anally (caudally) projecting neurons. Because few rostrally projecting neurons could be detected before birth, the full circuitry for peristaltic reflexes appears to develop after birth.

Animals↗
PubMed1999

Projections of neurons in the periaqueductal gray to pontine and medullary catecholamine cell groups involved in the modulation of nociception.

Stimulation of neurons in the periaqueductal gray (PAG) produces antinociception that is mediated in part by noradrenergic neurons that innervate the spinal cord dorsal horn. Because norepinephrine-containing neurons are not found in the PAG, noncatecholamine neurons in the PAG must project to, and activate, spinally projecting catecholamine neurons located in the pons or medulla. The present studies determined the projections of neurons in the ventrolateral PAG to the A5, A6 (locus coeruleus), and A7 catecholamine cell groups that are known to contain spinally projecting noradrenergic neurons. The anterograde tracer biotinylated dextran amine (BDA) was injected into the ventrolateral PAG, and labeled axon terminal profiles were identified near noradrenergic neurons that were visualized by processing tissue sections for tyrosine hydroxylase immunoreactivity. Highly varicose, anterogradely labeled terminal profiles were found apposed to the dendrites and somata of tyrosine-hydroxylase-immunoreactive neurons and non-tyrosine-hydroxylase-immunoreactive neurons in the dorsolateral and ventrolateral pontine tegmentum. These axon terminal profiles were more dense on the side ipsilateral to the BDA deposit, and both A7 and locus coeruleus neurons received a more dense innervation than did the A5 neurons. Although definitive evidence for a direct pathway from PAG neurons to spinally projecting A7 neurons requires ultrastructural studies, the results of the present studies provide presumptive evidence for direct projections from neurons in the PAG to noradrenergic A7 neurons that innervate the spinal cord dorsal horn and modulate pain perception. If neurons in the ventrolateral PAG do form synapses with noradrenergic A7 neurons, these spinally projecting catecholamine neurons may mediate part of the analgesic effect produced by systemic administration of morphine. In contrast, the projections of PAG neurons to the A5 cell group and the locus coeruleus may mediate the cardiovascular and motor effects produced by stimulation of sites in the ventrolateral PAG.

Animals↗
PubMed1999

Results of European projects enabling secure regional, national and international health care networks.

Based on the work of the ISHTAR, the TRUSTHEALTH1, the EUROMED-ETS and the MEDSEC project funded by the European Commission, the synergetic results of these different projects in providing a security infrastructure for the test environment of an oncological network will be demonstrated. The ISHTAR project investigated security issues in Health Care Establishments (HCE). It provides guidance for threat and risk analysis, and defines a schema for specification and implementation of appropriate security services and mechanisms to respond to the HCE security requirements of both communication and application security concepts. The TRUSTHEALTH1 project dealt with specification and test implementation of basic security services and mechanisms based on Health Professional Cards (HPC) and Trusted Third Party (TTP) services. Within the EUROMED-ETS project, the security solution has been extended to the Internet environment and WWW tools, successfully creating an Internet-based international TTP structure between the universities of Athens, Calabria, and Magdeburg. Finally, in the MEDSEC project the specification and implementation of a generic EDI security solution has been delivered to provide secure communication between applications and sites. In the ongoing TRUSTHEALTH2 project, the results of all these projects will be implemented in a real environment of cancer care.

Algorithms↗
PubMed2000

The SIP project: A national united approach to nursing informatics education in Denmark.

The SIP-project is a developmental project initiated by the deans of the Danish Nursing Schools on introducing and implementing the use and learning of Nursing Informatics in Danish nursing education. SIP is the acronym of SYGEPLEJE(Nursing) INFORMATIK (Informatics) and Paedagogik (Learning). This paper presents the background, structure, goals, expected and actual outcomes of the project and actual problems within the project. The SIP-project is a developmental project initiated by the deans of the Danish Nursing Schools on introducing and implementing the use and learning of Nursing Informatics in Danish nursing education. SIP is the acronym of SYGEPLEJE(Nursing) INFORMATIK (Informatics) and Paedagogik (Learning). This paper presents the background, structure, goals, expected and actual outcomes of the project and actual problems within the project.

Communication↗