PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Brain based”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 181 records · Page 10Linked to original sources
PubMed1999

Applying wavelet-transform on Internet-based radiologic brain images.

Wavelet-transform compression creates high-quality images of small file size by tuning its compression ratio between 10:1 and 80:1. We applied the wavelet-based compression technique to radiologic brain images on the Internet for image display purposes. Wavelet transform compression reduces file size up to 50%. Wavelet transform compression offers the advantage of retaining complete color information in digital images and faster Internet transmission than traditional Joint Photography Experts Group (JPEG) files of equivalent file size. The application of wavelet-based compression technique decreases storage requirements for images on Internet servers.

Brain↗
PubMedDate not supplied

Ultra-fast automated brain volumetry based on bispectral MR imaging data.

In this paper we present a fast automated three-dimensional brain segmentation and brain volumetry method providing minimal requirements of the number of spectral MR image channels and the performance of the computer equipment employed. The presented method is based on standard non-iterative two-dimensional grey level segmentation techniques in combination with pixel vector-oriented classificators and morphological operators and requires a bispectral high resolution MR data base. In its current design, the method provides for the largely partial volume-corrected determination of the cerebrospinal fluid (CSF) and the white and grey brain matter volumes of the human brain. For the verification of our approach, the results of applications to clinical data were compared to those of studies found in the literature.

Algorithms↗
PubMed2005

A new microcontroller-based human brain hypothermia system.

Many studies show that artificial hypothermia of brain in conditions of anesthesia with the rectal temperature lowered down to 33 degrees C produces pronounced prophylactic effect protecting the brain from anoxia. Out of the methods employed now in clinical practice for reducing the oxygen consumption by the cerebral tissue, the most efficacious is craniocerebral hypothermia (CCH). It is finding even more extensive application in cardiovascular surgery, neurosurgery, neurorenimatology and many other fields of medical practice. In this study, a microcontroller-based designed human brain hypothermia system (HBHS) is designed and constructed. The system is intended for cooling and heating the brain. HBHS consists of a thermoelectric hypothermic helmet, a control and a power unit. Helmet temperature is controlled by 8-bit PIC16F877 microcontroller which is programmed using MPLAB editor. Temperature is converted to 10-bit digital and is controlled automatically by the preset values which have been already entered in the microcontroller. Calibration is controlled and the working range is tested. Temperature of helmet is controlled between -5 and +46 degrees C by microcontroller, with the accuracy of +/-0.5 degrees C.

Brain↗
PubMed2003

Evaluation of the home and community-based services brain injury Medicaid Waiver Programme in Colorado.

PRIMARY OBJECTIVES: To evaluate Colorado's Traumatic Brain Injury (TBI) Waiver programme in terms of functional, community integration and other key psychosocial outcomes. RESEARCH DESIGN: Results of telephone surveys of 66 TBI survivors who had received services through the Colorado Medicaid programme were compared with those of a matched sample not receiving such services. METHODS AND PROCEDURES: Participants were identified by Colorado's Medicaid programme and a control group was randomly selected from the population-based Colorado Traumatic Brain Injury Registry and Follow-up System. Groups were matched on Glasgow Coma Scale score at injury, age, gender,whether inpatient rehabilitation had been received and the number of years post-injury when the follow-up interview was conducted. All participants completed an extensive follow-up interview, which included CHART, the Sickness Impact Profile, the Satisfaction with Life Scale, the SF-12 and questions on symptoms and service use. MAIN OUTCOMES AND RESULTS: For four of the evaluated outcomes-relating to mental health problems (SF-12) and alcohol use-the Medicaid Waiver group had significantly fewer problems than the control group. In eight areas, the Waiver group demonstrated poorer outcomes than the control group. The Waiver group scored significantly lower on most measures of societal participation (measured by CHART), needed more help with IADLS (instrumental activities of daily living) and were less likely to be competitively employed. Additionally, Waiver recipients had significantly more case management, physical therapy and group home services and more second rehabilitation admissions than the control group. No significant differences were found for the remaining 62 outcomes that were evaluated. CONCLUSIONS: Although there were significant differences between the two groups in a few important areas, it is impossible to conclude that any outcome differences--or lack of differences---are attributable to the Waiver programme alone, since many important potential group differences could not be adequately controlled for by the design. Recommendations are offered for future research to address these limitations.

Adolescent↗
PubMed1976

Significance of cranial circulation for the brain homeothermia in rabbits. II. The role of the cranial venous lakes in the defence against hyperthermia.

Chronic experiments were conducted on five freely moving rabbits at ambient temperatures of 0-42 degrees Celsius. The influence of nasal mucosal thermal changes on the venous blood temperature inside the pterygoid plexus and on the temperatures at three intracerebral sites were investigated against the background of the carotid arterial blood temperature shifts. A correlation was found between: (i) the fluctuations in the nasal mucosal temperature reflecting its vasomotor responses, (ii) temperature shifts of the pterygoid plexus venous blood, and (iii) of the ventral brain. Mucosal vasodilatation caused parallel drops in both the plexal blood and brain temperatures. However, mucosal vasoconstriction was accompanied by increases in temperatures at those sites. Intracranial thermal shifts were independent of the arterial blood temperature changes. During motor activity in normothermia nasal mucosal vasoconstriction was present, and in that case brain temperatures exceeded arterial blood temperature. During rest, mucosal vasodilatation appeared and brain base cooled below the arterial blood temperature. During panting in dry heat, the brain base was cooler than the arterial blood by as much as 0.5 degree Celsius. The intensity of the selective brain cooling was directly proportional to deep body temperature. The blockade of the respiratory evaporation in heat elicited an increase of the plexal venous blood as well as brain temperatures above the arterial blood temperature. We conclude that the venous blood outflowing from the nasal mucosa exerts a cooling influence on the brain through the pterygoid plexus.

Animals↗
PubMed1988

Nucleus basalis (Ch4) and cortical cholinergic innervation in the human brain: observations based on the distribution of acetylcholinesterase and choline acetyltransferase.

The nucleus basalis (NB) of the human brain is a large, complex, and highly differentiated structure. Many of its neurons are magnocellular, hyperchromic, isodendritic, acetylcholinesterase-rich, and choline-acetyltransferase-positive. Concurrent histochemical and immunological staining demonstrated that all choline-acetyltransferase-positive NB neurons in the human brain also contain acetylcholinesterase enzyme activity. Only a small minority of acetylcholinesterase-rich magnocellular cell bodies in the NB failed to show choline acetyltransferase immunoreactivity. Sections that were counterstained for Nissl substance showed that 80-90% of all magnocellular neurons in the NB were choline-acetyltransferase-positive and therefore cholinergic. These characteristics, which are very similar to those of the NB in the monkey brain, justified the designation of these cholinergic neurons in the human brain as the Ch4 (or NB-Ch4) complex. On morphological grounds, the compact parts of the human NB-Ch4 complex were divided into distinct sectors which appeared to show a greater level of differentiation than in the monkey brain. In addition to the compact sectors, interstitial elements of NB Ch4 were embedded within adjacent fiber bundles. The putative cortical projections from NB-Ch4 were identified in the form of acetylcholinesterase-rich fibers. These fibers formed a dense plexus in all cortical regions but also displayed laminar and regional variations. Limbic and paralimbic areas had higher concentrations of these fibers than the immediately adjacent neocortical association areas. Alzheimer's disease was associated with a marked depletion of cortical acetylcholinesterase. Two cases of Alzheimer's disease with relatively selective NB-Ch4 cell loss supported the hypothesis that the corticopetal cholinergic pathways in the human brain may have a topographical organization similar to that in the monkey brain.

Acetylcholine↗
PubMed2003

Renovating the house of being: genomes, souls, and selves.

In recent years, the views of the German philosopher Peter Sloterdijk about humanism and the biological self-engineering of mankind caused much turmoil in European intellectual circles. However, this is just one episode in a more general current controversy about the ethics of self-manipulation, a debate that often centers around the recent progress in genomics and the possibility of shaping human genetic structure. The complete sequencing of the human genome has reinforced this focus. Making the human genome the object of a highly visible world-wide research effort has reinforced popular notions stressing the centrality of the genome in defining individuality and humanity. As a result, proponents and opponents of the self-engineering of human nature have often concentrated on technologies related to the genome. However, if one compares "genome-based" and "brain-based" explanations of Self and behavior, it turns out that neural aspects of human nature are more directly relevant. Many philosophical and ethical questions traditionally raised about genetics and genomics acquire more relevance and urgency when re-examined in the context of neuroscience.

Bioethics↗
PubMed1994

Radiosurgical treatment planning of brain metastases based on a fast, three-dimensional MR imaging technique.

A fast, three-dimensional (3D) sequence for magnetic resonance (MR) imaging of the brain and its application in radiosurgical treatment planning of brain metastases is reported. The measuring sequence (MPRAGE) requires magnetization-prepared 180 degrees inversion pulses followed by rapid low angle excitation pulses and gradient-echoes for image generation. The resulting T1-weighted MPRAGE images were compared with two-dimensional (2D) T1-weighted spin-echo (SE) images after administration of 0.1 mmol/kg b.w. Gd-DTPA in 10 patients with known brain metastases. Original or multiplanar reformatted images obtained from a 128 partition data set of the 3D MPRAGE sequence offered comparable diagnostic quality to that of 2D SE imaging. Gd-DTPA enhancement and lesion targeting was similar in most of the patients in SE as well as MPRAGE imaging. During imaging and therapy the patient's head was fixed in a stereotactic localization system which is usable at the MR and the linear accelerator installations. The dose calculation of the radiosurgery planning was based on 3D MR imaging data assuming a homogenous attenuation value inside the head which was sufficient for an accurate dose calculation since tissue inhomogeneities do not significantly influence the shape of the relative dose distribution especially for radiosurgery of the brain. Under this circumstance the dose calculation can be based only on the 3D geometric conformation of the patient's head. A simple algorithm for treatment planning can be used if the MR data are free of geometric distortion.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗
PubMed1991

A new model of focal brain ischemia based on the intracerebral injection of endothelin-1.

Endothelin-1 and its receptors are widely distributed in the brain of rodents and humans. In view of its potent and long-lasting vasoconstrictor activity, a role of endothelin-1 has been proposed in brain ischemia. In the present paper, the local injection of endothelin-1 was utilized to induce ischemia in rat striatum. An evaluation of the rostrocaudal extension of the lesion is reported. By using intracerebral microdialysis, a marked increase of lactate and dopamine, but not glutamate, was observed in this region upon endothelin-1 administration. Moreover, preliminary data reported show a protective effect of ganglioside treatment on endothelin-1 lesion of rat striatum. The characteristics of the present model of brain ischemia are discussed in comparison with well characterized models, such as the Pulsinelli's four vessel occlusion and the middle cerebral artery occlusion.

Animals↗
PubMed2005

Anatomical signatures of dyslexia in children: unique information from manual and voxel based morphometry brain measures.

Thirteen male control and thirteen male dyslexic children (age, 121-152 months) were studied to determine if voxel based morphometry (VBM) could identify anatomical differences in the right cerebellar anterior lobe, and right and left pars triangularis that were identified with manual measures of the same children. VBM demonstrated significant gray and white matter differences in these three brain regions. In contrast to the manual results, these differences were not significant after controlling for brain volume, suggesting the manual measures captured additional important variance that distinguished the groups. Post-hoc VBM comparisons demonstrated white matter volume differences in a left temporal-parietal region that are consistent in location with results from diffusion tensor imaging studies of dyslexia. The VBM analyses also identified, gray matter volume differences in the left and right lingual gyrus, left inferior parietal lobule and cerebellum, areas that had not been examined with manual methods. We conclude that manual and automated methods provide valuable and complementary approaches to the search for functionally significant neurobiological characteristics of dyslexia.

Brain↗
PubMed2003

Imaging of L-glutamate fluxes in mouse brain slices based on an enzyme-based membrane combined with a difference-image analysis.

A time-resolved imaging method for visualizing L-glutamate release in mammalian brain slices is proposed by using an enzyme membrane combined with a difference-image analysis. The enzyme membrane is composed of L-glutamate oxidase and horseradish peroxidase incorporated into a bovine serum albumin matrix. L-Glutamate triggers an enzyme-coupling reaction to convert a redox substrate (DA-64) to Bindschedler's Green, which gives a green color signal. The difference-image analysis is based on calculating slopes of a signal versus time (t) plot in the time range from (t - 40 s) to (t + 40 s) for visualizing L-glutamate release in terms of its flux (in mol min(-1) cm(-2)). The method was applied to a time-resolved imaging of hippocampal distribution of ischemia-induced L-glutamate release in mouse brain slices. The image of L-glutamate distribution showed that the level and time courses of L-glutamate fluxes were neuronal region-dependent. The maximum flux of L-glutamate at CA1 was observed at 7.7 min after ischemia. The flux at 7.7 min increased in the order of CA1 approximately CA3 > DG. The time course of the L-glutamate flux in the CA1 region was biphasic and that in the DG region was modestly biphasic. In the CA3 region, such biphasic release of L-glutamate was not seen. The ischemia-induced L-glutamate flux was accelerated when Mg2+ was omitted from an extracellular solution. The present enzyme membrane-based approach provides a useful method for visualizing distribution of L-glutamate release in the brain slices during ischemia.

Amino Acid Oxidoreductases↗
PubMed1989

D2 dopamine receptors in the human brain: heterogeneity based on differences in guanine nucleotide effect on agonist binding, and their presence on corticostriatal nerve terminals.

In human brain, regulation of agonist binding to the D2 dopamine receptors by guanine nucleotides is different between several regions. In membranes of the anterior pituitary lobe, agonist binding is fully sensitive to GTP or Gpp(NH)p, whereas it is resistant in membranes of globus pallidus. Both guanine nucleotide-sensitive (G-S) and -insensitive (G-I) receptors are found in membranes of the striatum. The G-S and G-I type receptors display similar affinities for antipsychotic drugs of different classes, suggesting that they only differ in their effector-coupling system. We investigated the D2 receptors in striatal membranes of postmortem human brains in which corticostriatal pathways were unilaterally destroyed by an infarction. Compared to the intact side, D2 receptor densities in striata from the lesioned side were reduced by 46-65%, whereas the densities of the muscarinic cholinergic receptors, dopamine uptake sites, and D1 dopamine receptors were unchanged. In the deafferented striata all G-I, but also a substantial number of G-S receptors were lost, suggesting that both receptor subtypes are present on corticostriatal nerve terminals.

Adult↗