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PubMed2005

Anatomical differences in the mirror neuron system and social cognition network in autism.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder associated with impaired social and emotional skills, the anatomical substrate of which is still unknown. In this study, we compared a group of 14 high-functioning ASD adults with a group of controls matched for sex, age, intelligence quotient, and handedness. We used an automated technique of analysis that accurately measures the thickness of the cerebral cortex and generates cross-subject statistics in a coordinate system based on cortical anatomy. We found local decreases of gray matter in the ASD group in areas belonging to the mirror neuron system (MNS), argued to be the basis of empathic behavior. Cortical thinning of the MNS was correlated with ASD symptom severity. Cortical thinning was also observed in areas involved in emotion recognition and social cognition. These findings suggest that the social and emotional deficits characteristic of autism may reflect abnormal thinning of the MNS and the broader network of cortical areas subserving social cognition.

Adult↗
PubMed2004

Systemic effects of local allergic disease.

Allergic reactions are not confined to the area they originated, but assume a secondary systemic, nonanaphylactic element. This element has two consequences: it feeds back into the site of the original reaction and it leads to the development of distant local manifestations. The well-established interactions between the nasal and the lower airways in allergic disease could be viewed as an example of this model. Interactions between the nasal mucosa and the paranasal sinuses, as well as interactions between the respiratory system, the skin, and the gastrointestinal tract have been described and may also fall under the same category. Two conduits of the systemic element of allergic disease are proposed: the systemic circulation and the nervous system. The mechanisms that lead to the development of the systemic element, and particularly the mechanisms of distant manifestations after a local allergic reaction have not been elucidated, but they probably include intricate interactions between the classic mediators of the acute allergic reaction, locally- and systemically-produced cytokines and neurotrophins, the vascular epithelium and the adhesion molecule system, the chemokine network, antigen-presenting dendritic cells and their interactions with T-lymphocytes, as well as a strong bone marrow component. From this perspective, the systemic element presents an exciting area of current and future research in allergic disease.

Asthma↗
PubMed2001

Developing palliative care services in regional areas. The Ipswich Palliative Care Network model.

BACKGROUND: Although there are over 350 palliative care services present in Australia and New Zealand, the distribution of these is patchy. Patients in some regional and rural areas have little or no access to specialist services, and manage with the enthusiasm and general expertise of local practitioners. OBJECTIVE: This paper discusses the problems encountered in maintaining skills in palliative care in the face of small patient numbers and poor resources, and describes a solution that was developed in Ipswich, Queensland. DISCUSSION: The twin problem of GP skills maintenance and adequate community service provision in palliative care can be overcome by developing a general practice based service in conjunction with local health authorities and the community. Highlighting the benefits to the health authority and the community of maximal general practitioner involvement is the most important lever in securing cooperation.

Australia↗
PubMed2002

Distortion correction for x-ray image intensifiers: local unwarping polynomials and RBF neural networks.

In this paper we present two novel techniques, namely a local unwarping polynomial (LUP) and a hierarchical radial basis function (HRBF) network, to correct geometric distortions in XRII images. The two techniques have been implemented and compared, in terms of residual error measured at control and intermediate points, with local and global methods reported in the previous literature. In particular, LUP rests on a locally optimized 3rd degree polynomial applied within each quadrilateral cell on the rectilinear calibration grid of points. HRBF, based on a feed-forward neural network paradigm, is constituted by a set of hierarchical layers at increasing cut-off frequency, each characterized by a set of Gaussian functions. Extensive experiments have been performed both on simulated and real data. In simulation, we tested the effect of pincushion, sigmoidal and local distortions, along with the number of calibration points. Provided that a sufficient number of cells of the calibration grid is available, the obtained accuracy for both LUP and HRBF is comparable to or better than that of global polynomial technique. Tests on real data, carried out by using two different (12 in. and 16 in.) XRIIs, showed that the global polynomial accuracy (0.16+/-0.08 pixels) is slightly worse than that of LUP (0.07+/-0.05 pixels) and HRBF (0.08+/-0.04 pixels). The effects of the discontinuity at the border of the local areas and the decreased accuracy at intermediate points, typical of local techniques, have been proved to be smoothed for both LUP and HRBF.

Algorithms↗
PubMed2003

A conduit system distributes chemokines and small blood-borne molecules through the splenic white pulp.

Access to the splenic white pulp is restricted to lymphocytes and dendritic cells. Here we show that movement of molecules from the blood into these confined areas is also limited. Large molecules, such as bovine serum albumin (68 kD), immunoglobulin G (150 kD), and 500 kD dextran are unable to enter the white pulp, whereas smaller blood-borne molecules can directly permeate this compartment. The distribution is restricted to a stromal network that we refer to as the splenic conduit system. The small lumen of the conduit contains collagen fibers and is surrounded in the T cell areas by reticular fibroblasts that express ER-TR7. It also contains the chemokine CCL21. Conversely, in B cell follicles the B cell-attracting chemokine CXCL13 was found to be associated with the conduit and absence of ER-TR7+ fibroblasts. These results show heterogeneity of reticular fibroblasts that enfold the conduit system and suggest that locally produced chemokines are transported through and presented on this reticular network. Therefore, the conduit plays a role in distribution of both blood-borne and locally produced molecules and provides a framework for directing lymphocyte migration and organization of the splenic white pulp.

Animals↗
PubMed2005

Measurements of groundwater velocity in discrete rock fractures.

Estimating groundwater velocity in fracture networks using a Darcy or cubic law calculation is complicated by the wide distribution of fracture aperture often found in these systems and by the difficulty in measuring hydraulic head in discrete fracture features. Although difficult to conduct in a fractured rock setting, the point dilution method can be utilized to collect direct measurements of groundwater velocity in individual fractures. To compare measured against calculated velocities, more than 100 point dilution experiments were conducted within a 35 x 35 m area of a single fracture and in discrete fracture features within a fracture network at a larger scale. The dilution experiments were conducted by isolating a fracture feature in a borehole, measuring the hydraulic aperture, and measuring the decay of an injected tracer due to the advective groundwater flux across the fracture. Groundwater velocity was estimated using the hydraulic aperture and the rate of decay of the injected tracer. Estimates of the local hydraulic gradient were calculated via the cubic law using the velocity estimate and the hydraulic aperture. The results of the tests conducted in the single fracture show variable (1 to 33 m/day) but on average higher velocities in comparison to that measured during a natural gradient tracer experiment conducted previously (in which the effects of matrix diffusion were accounted for) and to that which would be calculated using the cubic law. Based on these results, it was determined that the best estimate of the average groundwater velocity, at the scale of the measurement area used for the cubic law calculations, could only be obtained using the largest apertures in the aperture distribution. Variability of the velocity measurements was also observed over time. Increases in velocity were attributed to the effect of rainfall although concurrent increases in hydraulic gradient were not detected (likely within the tolerance of the measuring devices). The groundwater velocities measured in the fracture network varied over a wider range than at the scale of the single fracture (from 2 to 388 m/day). No correlation, however, was observed between the size of the fracture aperture and measured velocity.

Environmental Monitoring↗
PubMed2005

A new approach to neuroimaging with magnetoencephalography.

We discuss the application of beamforming techniques to the field of magnetoencephalography (MEG). We argue that beamformers have given us an insight into the dynamics of oscillatory changes across the cortex not explored previously with traditional analysis techniques that rely on averaged evoked responses. We review several experiments that have used beamformers, with special emphasis on those in which the results have been compared to those observed in functional magnetic resonance imaging (fMRI) and on those studying induced phenomena. We suggest that the success of the beamformer technique, despite the assumption that there are no linear interactions between the mesoscopic local field potentials across distinct cortical areas, may tell us something of the balance between functional integration and segregation in the human brain. What is more, MEG beamformer analysis facilitates the study of these complex interactions within cortical networks that are involved in both sensory-motor and cognitive processes.

Algorithms↗
PubMed2001

Association of the distinct visual representations of faces and names: a PET activation study.

A PET study of seven normal individuals was carried out to investigate the neural populations involved in the retrieval of the visual representation of a face when presented with an associated name, and conversely. Face-name associations were studied by means of four experimental matching conditions, including the retrieval of previously learned (1) name-name (NN), (2) face-face (FF), (3) name-face (NF), and (4) face-name (FN) associations, as well as a resting scan with eyes closed. Before PET images acquisition, subjects were presented with 24 unknown face-name associations to encode in 12 male/female couples. During PET scanning, their task was to decide whether the presented pair was a previously learned association. The right fusiform gyrus was strongly activated in FF condition as compared to NN and Rest conditions. However, no specific activations were found for NN condition relative to FF condition. A network of three areas distributed in the left hemisphere, both active in (NF-FF) and (FN-NN) comparisons, was interpreted as the locus of the integration of visual faces and names representations. These three regions were localized in the inferior frontal gyrus (BA 45), the medial frontal gyrus (BA 6) and the supramarginal gyrus of the inferior parietal lobe (BA 40). An interactive model accounting for these results, with BA 40 seen as an amodal binding region, is proposed.

Adult↗
PubMed2002

MR perfusion imaging in a case of cerebral proliferative angiopathy.

Proliferative angiopathy is an uncommon type of cerebral arteriovenous shunt characterized by an extensive capillary network with normal brain intermingled and few clinical symptoms (mostly seizures and headaches). This case report depicts an extensive proliferative angiopathy located in the right hemisphere. Its hemodynamic disturbances were studied with MR perfusion imaging (local or remote areas of increased time to peak, decrease ratio of signal, and relative regional cerebral blood volume values).

Adult↗
PubMed1999

Surface-induced polymerization of actin.

Living cells contain a very large amount of membrane surface area, which potentially influences the direction, the kinetics, and the localization of biochemical reactions. This paper quantitatively evaluates the possibility that a lipid monolayer can adsorb actin from a nonpolymerizing solution, induce its polymerization, and form a 2D network of individual actin filaments, in conditions that forbid bulk polymerization. G- and F-actin solutions were studied beneath saturated Langmuir monolayers containing phosphatidylcholine (PC, neutral) and stearylamine (SA, a positively charged surfactant) at PC:SA = 3:1 molar ratio. Ellipsometry, tensiometry, shear elastic measurements, electron microscopy, and dark-field light microscopy were used to characterize the adsorption kinetics and the interfacial polymerization of actin. In all cases studied, actin follows a monoexponential reaction-limited adsorption with similar time constants (approximately 10(3) s). At a longer time scale the shear elasticity of the monomeric actin adsorbate increases only in the presence of lipids, to a 2D shear elastic modulus of mu approximately 30 mN/m, indicating the formation of a structure coupled to the monolayer. Electron microscopy shows the formation of a 2D network of actin filaments at the PC:SA surface, and several arguments strongly suggest that this network is indeed causing the observed elasticity. Adsorption of F-actin to PC:SA leads more quickly to a slightly more rigid interface with a modulus of mu approximately 50 mN/m.

Actins↗
PubMed2005

Control of blood vessel structure: insights from theoretical models.

Blood vessels are capable of continuous structural adaptation in response to changing local conditions and functional requirements. Theoretical modeling approaches have stimulated the development of new concepts in this area and have allowed investigation of the complex relations between adaptive responses to multiple stimuli and resulting functional properties of vascular networks. Early analyses based on a minimum-work principle predicted uniform wall shear stress in all segments of vascular networks and led to the concept that vessel diameter is controlled by a feedback system based on responses to wall shear stress. Vascular reactions to changes in transmural pressure suggested feedback control of circumferential wall stress. However, theoretical simulations of network adaptation showed that these two mechanisms cannot, by themselves, lead to stable and realistic network structures. Models combining reactions to fluid shear stress, circumferential stress, and metabolic status of tissue, with propagation of stimuli upstream and downstream along vascular segments, are needed to explain stable and functionally adequate adaptation of vascular structure. Such models provide a basis for predicting the response of vascular segments exposed to altered conditions, as, for example, in vascular grafts.

Animals↗
PubMed2006

Longitudinal analysis of the impact and cost of person-centered planning for people with intellectual disabilities in England.

Person-centered planning is central to United Kingdom policies regarding the support of people with intellectual disabilities. However, little evidence exists on the impact or cost of introducing person-centered planning. We examined the efficacy, effectiveness, and costs of introducing person-centered planning for 93 people with intellectual disabilities over 2 years across four localities in England. A person-centered plan was successfully developed for 65 people. Little change was apparent prior to introducing person-centered planning. After its introduction, modest positive changes were found in the areas of social networks; contact with family; contact with friends; community-based activities; scheduled day activities; and choice. The direct training and support cost of introducing person-centered planning was $1,202 per participant; indirect costs were negligible.

Activities of Daily Living↗
PubMed2004

Coupling field theory with mesoscopic dynamical simulations of multicomponent lipid bilayers.

A method for simulating a two-component lipid bilayer membrane in the mesoscopic regime is presented. The membrane is modeled as an elastic network of bonded points; the spring constants of these bonds are parameterized by the microscopic bulk modulus estimated from earlier atomistic nonequilibrium molecular dynamics simulations for several bilayer mixtures of DMPC and cholesterol. The modulus depends on the composition of a point in the elastic membrane model. The dynamics of the composition field is governed by the Cahn-Hilliard equation where a free energy functional models the coupling between the composition and curvature fields. The strength of the bonds in the elastic network are then modulated noting local changes in the composition and using a fit to the nonequilibrium molecular dynamics simulation data. Estimates for the magnitude and sign of the coupling parameter in the free energy model are made treating the bending modulus as a function of composition. A procedure for assigning the remaining parameters in the free energy model is also outlined. It is found that the square of the mean curvature averaged over the entire simulation box is enhanced if the strength of the bonds in the elastic network are modulated in response to local changes in the composition field. We suggest that this simulation method could also be used to determine if phase coexistence affects the stress response of the membrane to uniform dilations in area. This response, measured in the mesoscopic regime, is already known to be conditioned or renormalized by thermal undulations.

Computer Simulation↗
PubMedDate not supplied

Attitudes and perceptions related to smoking among pregnant and postpartum women in a low-income, multiethnic setting.

PURPOSE: The purpose of this study was to gain insight into attitudes and perceptions about smoking during pregnancy, passive smoke exposure, barriers to quitting, and program preferences among women in a low-income, ethnically diverse setting. DESIGN: Nine focus group discussions were conducted with African-American, Native American, and white women. Discussions were moderated by local residents who shared the same ethnic background as group participants. SETTING: Discussions were held in neighborhood centers and clinics in an urban area. SUBJECTS: A total of 57 women participated. Moderators recruited participants from within their social networks and from neighborhood programs. The informal process of recruitment did not allow calculation of response rates. MEASURES: A series of open-ended questions with selected probes was used to guide the conversation. RESULTS: Participants were aware that smoking during pregnancy is harmful and were concerned to varying degrees about their smoking behavior. Most women who smoked took active steps to reduce the risks. Actions were frequently accompanied by beliefs that rationalized moderate levels of smoking. While concerned, women were uncertain about what constituted harmful, passive smoke exposure. Personal barriers to quitting included being around others who smoked, feelings of stress and boredom, addiction, and not believing smoking is dangerous enough. Participants tended to value pregnancy-related advice from female friends and relatives over advice from professionals. CONCLUSIONS: Results suggest that many women respond to warnings about smoking during pregnancy, but actions are not necessarily measured in quit rates. Misconceptions about the risks may help to rationalize continued smoking. Subjects lacked knowledge about how best to reduce the risks of passive smoke. Educational efforts may be effective when directed at networks of women who share information. The nature of qualitative data collection prevents extrapolation of these results to a larger population.

Adolescent↗
PubMed1998

Nitric oxide synthase and the acetylcholine receptor in the prefrontal cortex: metasynaptic organization of the brain.

Nitric oxide synthase (NOS) and the nicotinic acetylcholine receptor (nAChR) immunoreactivity of the cerebral cortex was studied in adult Macaca fascicularis monkeys at light- and electron microscopic levels. NOS was located by means of the polyclonal antibodies developed by Transduction Laboratories (Lexington, KY, USA), as primary serum, in a dilution of 1:1000, and nAChR was located by means of biotinylated alpha-bungarotoxin (BTX) obtained from Molecular probes (Eugene, Oregon, USA) in a dilution of 1:2000. While endothelial eNOS outlined blood vessels in the brain, brain-derived (neural) bNOS labelled three well-defined cell types in area 46 of the prefrontal cortex, viz. (a) bipolar cells, scattered through layers III to V, equipped with long dendrites which pass over the thickness of the cortex in a right angle to the pial surface, establishing dendritic bundles closely reminiscent of a columnar organization; (b) large multipolar cells, located mainly in layers V and VI, with axons which interconnect dendritic bundles of the bipolar cells and establish synapses with dendritic shafts and spines of the former; and (c) stellate cells, located in lamina II and III, which establish an axonal network in lamina zonalis (lamina I). This arrangement is most characteristic in area 46 of the prefrontal cortex; areas 10 and 12 display similar features. In contrast, the primary visual cortex (area 17), is lacking any sign of columnar organization. Localization of bNOS immunoreactivity is at marked variance to that of NADPH-diaphorase which labels large pyramidal cells in the primate cortex. Binding of alpha-bungarotoxin (BTX) which labels the alpha 7 subunit of nAChR is located in somata, dendrites and axons of interneurons scattered over the entire width of the prefrontal cortex; on the other hand, the monoclonal antibody mAb 35 which labels subunits alpha 1, alpha 3 and alpha 5 in the main immunogenic region of the receptor, visualizes apical dendritic shafts similar to those like bNOS. Strategic localization of bNOS in the primate prefrontal cortex fulfills criteria of producing a freely diffusing retrograde messenger molecule operative in signal transduction routes subserving topography and columnar organization of the cortex, as well as long-term potentiation and long-term depression phenomena underlying mnemonic and gnostic functions. Common occurrence of bNOS and nAChR in identical or similar structures in the prefrontal cortex suggests that interactions between nitrogen oxide and presynaptically released acetylcholine might be involved in the metasynaptic organization of the cerebral cortex, operating in a non-synaptic manner in maintaining optimal performance on cognitive tasks.

Animals↗
PubMed2006

'They get a bit funny about going'--transfer issues for rural and remote Australian Aboriginal people.

BACKGROUND: The integration of health care among providers to achieve good outcomes has been investigated in urban locations. However, more information is needed about what happens to people from rural areas, particularly when travelling away from their families and healthcare provider to receive hospital care. Therefore, a national project was conducted in 2004 that aimed: to document the experiences of people travelling to and from rural and remote areas to city hospitals; to identify factors that affect their optimal health outcomes; and to improve the exchange of information between primary healthcare providers and hospital staff. The Australian Rural Health Education Network (AHREN) coordinated the study, which consisted of several case studies. This article, part of the larger investigation, presents a segment on issues for Aboriginal people living in a rural and remote Australian area that were identified by local health workers, and suggestions that might assist in overcoming them. METHOD: Research and ethics approval was obtained from our university, hospital and the Aboriginal Health Council. Three Aboriginal health workers, employed at the community controlled Aboriginal health centre, involved in transport, consented to be audiotaped in a group interview. They are named researchers. Questions were: What are the issues in transfer to and from the city hospital? What special problems exist for the Aboriginal people you are involved with? What improvements/systems changes would you suggest? FINDINGS: Funding and equity of the Patient Assisted Transport Scheme (PATS) created problems. Raising payments for PATS and extra costs to clients and families were big issues. Antisocial arrival times, separation from family, transport to hospital and accommodation all caused distress and confusion. Potentially dangerous misunderstandings happened through language and cultural differences. Traditional people travelling unaccompanied were at risk. Often PATS notification requirements could not be met in emergencies and onsite accommodation was described as frightening and culturally inappropriate. At the time of interview, Stepdown transport did not cover people staying with families. Lack of privacy, different understandings of family and other issues important for Aboriginal people continue to add stress for families already suffering. DISCUSSION: PATS could be streamlined and more user-friendly. Aboriginal Liaison Officers in hospitals provide a link for Aboriginal clients, but unrealistic expectations may be placed on them and they are not available 24 hours a day. Strategies for improved communication are needed. A space and campfire in hospital grounds for traditional people and their families to gather would assist.

Attitude to Health↗
PubMed1993

Medical and economic consequences of gang-related shootings.

Treatment costs for victims of gang violence have fueled the withdrawal of hospitals from trauma networks. Not included in such tallies are the medical resources that these seriously ill and medically indigent patients divert from other areas. We examined the surgical care requirements, costs incurred, and outcomes at a Level I trauma center. Local law enforcement records were matched with hospital admissions over a 1-year period to identify with hospital admissions over a 1-year period to identify casualties of gang violence. Of 191 gunshot wound admissions, 107 (56%) were gang related. The majority were males (92%); ages ranged from 14 to 50 and trauma scores from 1-16. Eighty-six were admitted during periods of minimum staffing (7:00 PM to 7:00 AM), pre-emptying the use of limited resources for other medical/surgical emergencies. Fifty-eight (54%) needed emergency surgery: laparotomy (38), thoracotomy (5), and neck/extremity (15). Forty required multiple surgical procedures, and eight patients required nine subsequent surgeries. There were two deaths. Average hospital stay ranged from 1 to 180 days; inpatient days totalled 1003, 270 of which were spent in the ICU. Total charges neared +2.0 million. Ninety-four patients (88%) were medically indigent. On discharge, 75 patients were disabled, six permanently. We conclude: 1) Gang activity caused the majority of gunshot wounds at our trauma center; 2) multiple injuries predominated, requiring extensive ICU use; 3) the combination of indigent patients and high hospital costs underestimate the financial burden as valuable resources are diverted from other areas; 4) subsequent community costs include rehabilitation and chronic care.

Adolescent↗
PubMed1999

Localization of the Wilson's disease protein in human liver.

BACKGROUND & AIMS: Wilson's disease is an autosomal-recessive disorder of copper metabolism that results from the absence or dysfunction of a copper-transporting P-type adenosine triphosphatase that leads to impaired biliary copper excretion and disturbed holoceruloplasmin synthesis. To gain further insight into the role of the Wilson's disease protein in hepatic copper handling, its localization in human liver was investigated. METHODS: By use of a specific antibody, localization of the Wilson's disease protein was studied in liver membrane fractions and liver sections by immunoblotting, immunohistochemistry, and double-label confocal scanning laser microscopy. RESULTS: The 165-kilodalton protein, found by immunoblotting, was most abundant mainly in isolated plasma membrane fractions enriched in canalicular domains. Immunohistochemistry revealed intracellular punctuate staining of hepatocytes in certain regions of the liver, whereas a canalicular membrane staining pattern was observed in other regions. Double-labeling studies showed that in the latter regions the transporter is present mainly in vesicular structures just underneath the canalicular membrane that are positive for markers of the trans-Golgi network. A weak staining of the canalicular membrane, identified by staining for P-glycoprotein, was observed. CONCLUSIONS: These results show that in human liver the Wilson's disease protein is predominantly present in trans-Golgi vesicles in the pericanalicular area, whereas relatively small amounts of the protein appear to localize to the canalicular membrane, consistent with a dual function of the protein in holoceruloplasmin synthesis and biliary copper excretion.

Adenosine Triphosphatases↗