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PubMed1984

Is matter inanimate? Protobiological information from within.

Biological information refers to the process of how matter informs matter through endogenous boundary conditions, exhibiting a sharp contrast to Shannon's information referring to the process of how coded messages inform a human receiver or observer. The origin and evolution of protobiological and biological information occur because prior polymeric products successively provide new boundary conditions to the subsequent production process. The transition from what looks like inanimate matter to living beings is a continuous process. The underlying mechanism is the physical process that prior products provide new boundary conditions to the subsequent production process in a successive manner. Biological information resides in perpetuating cellular production process which eventually leads to an enhancement of evolutionary specificity. Cellular units are prerequisite to biological evolution, not vice versa.

Animals↗
PubMed1981

Protease activities in normal and schizophrenic human prefrontal cortex and white matter.

Endo- and exopeptidase activities have been measured post-mortem human prefrontal cortex and subjacent white matter to estimate their relative capabilities for protein and peptide degradation. Cathepsin D and three dipeptidases versus leucyl-glycine, glycyl-L-leucine and glycyl-glycine) were assayed in serial, microtome prepared frozen sections (+/- 125 micrograms fresh weight) and related to histological composition (Nissl stain), dry weight, total protein, and DNA content. RNA concentrations were similarly determined, serving as approximate indices of protein synthetic potential. Cathepsin D activity and RNA concentration were, respectively, threefold and twofold greater in cortical gray than in subcortical white matter. Each dipeptidase showed somewhat higher activity in white matter than in cortex. In both tissues the order of activities were: glycyl-leucine greater than glycyl-glycine greater than leucyl-glycine dipeptidase. The results are consistent with preferential localizations of cathepsin D in cortical neurons and dipeptidases in neuroglia. None of the four enzymes showed differences in activity in comparable cortex from six patients with chronic schizophrenia.

Adult↗
PubMed1980

Cytology and time of origin of interstitial neurons in the white matter in infant and adult human and monkey telencephalon.

The fine structure, synaptic relationships, distribution and time of origin of interstitial neurons situated within the white matter subjacent to the visual, somatosensory and motor cortices were studied in the human and monkey telencephalon. The analysis was carried out on Nissl-stained serial sections, rapid Golgi impregnations, by acetylcholinesterase (AChE) histochemistry, electron microscopy and [3H]thymidine ([3H]TdR) autoradiography. Interstitial neurons have a similar distribution, morphology and histochemistry in both human and monkey telencephalon. Their highest density and the most extensive distribution is found in the neonatal period in both species. The number of interstitial neurons decreases during infancy, but numerous cells remain in the adult. Two types of interstitial neuron can be recognized in Golgi preparations: polymorphic cells, usually situated close to the cortex and fusiform cells, located predominantly in the depths of the white matter. The polymorphic cell type is prevalent during neonatal and infant stages, while fusiform cells are relatively more numerous in the adult. Interstitial cells have ultrastructural features and organelles typical of neurons of the central nervous system with well-defined axosomatic and axodendritic synapses of both symmetrical and asymmetrical types. About 20% fo the interstitial cells show strong specific AChE activity. Autoradiographic analysis of postnatal monkeys exposed to [3H]TdR at various embryonic (E) and early postnatal days indicates that interstitial neurons which lie beneath the visual and somatosensory-motor cortices are generated between E38 and E48. Contrary to the prevailing notion that interstitial neurons are the latest generated cells arreste during migration across the maturing white matter, they prove to be produced at the end of the first third of the 165-day gestation in the rhesus monkey concomitantly with the generation of neurons destined for the deep neocortical layers. These findings raise the possibility that interstitial cells represent a vestige of the transient embryonic subplate layer.

Acetylcholinesterase↗
PubMed1991

Immunocytochemical identification of GABA in astrocytes located in white matter after inhibition of GABA-transaminase with gamma-acetylenic GABA.

Several lines of evidence suggest that astrocytes contribute to the uptake and degradation of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). Recent immunohistochemical studies have shown that GABA-like immunoreactivity can be demonstrated in astrocytes in the grey matter of the rat's brainstem. The present study investigates whether GABA is also present in astrocytes located in the white matter. Adult rats were given gamma-acetylenic GABA (GAG), which inhibits the GABA-degratory enzyme GABA-alpha-ketoglutaric acid aminotransferase, and tissue sections from the cerebral cortex and brainstem were processed for GABA immunohistochemistry using an antiserum to GABA. Light microscopic examination of the sections showed numerous small GABA-immunoreactive cells in fibre tracts as well as in nuclear regions. Electron microscopic examination of the immunoreactive cells showed that they were fibrous astrocytes. The results provide evidence that the large increase in GABA in fibre tracts found in biochemical studies of rats injected with GAG is due to an increase in astrocytic GABA and suggest that fibrous astrocytes regulate GABA levels in the extracellular space of white matter.

4-Aminobutyrate Transaminase↗
PubMed1991

The efferent projections of neurons in the white matter of different cortical areas of the adult rat.

Injection of Fast Blue into different cortical areas (frontal, parietal, anterior and posterior cingulate cortex) revealed that neurons in the white matter (interstitial neurons) give rise to association fibers which project mostly to the gray matter of the overlying cytoarchitectonic area, but which may extend also over different cytoarchitectonic areas. The rostrocaudal extent of the projecting axons was up to 1 mm in the frontal and parietal cortex, and up to 3.5 mm in the cingulate cortex. Concurrent processing for dihydronicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry showed that 70% of cortically projecting interstitial neurons were NADPH-d-positive. An analysis of neuronal morphology suggests that the FasT-Blue-labeled, NADPH-d-negative neurons may represent displaced pyramidal neurons of layer VIb; the Fast-Blue-labeled and NADPH-d-positive neurons have bipolar or multipolar dendritic trees, constituting a population of nonpyramidal interstitial neurons that project into the cortical gray matter.

Amidines↗
PubMed1983

Thinking about mind and matter from biology.

In biology, man is an object of research; therefore the question might be asked whether inspirations can go from biological data to the reflections on the mind-matter relation in man. The social aspect of man, as treated by sociobiology, is left out of consideration. The knowledge that man is mind, or has a mind, is no result of biological research. It is a datum from philosophy. The biologist, however, is living in a culture which knows about the mental character of man, and this is incorporated in his investigations. He knows that mental activities are connected with processes in the central nervous system and that, especially in the brain, localizations of mental activities are found. As a result of the split-brain experiments with patients and animals, some have arrived at the conclusion that there is a double consciousness. An approach from biology can lead to statements of a philosophical character, as, for example, statements about the unity, or even identity, of mind and matter. The theories of identity meet with great interest in scientific circles, and the truth value of identity statements is investigated. The system theory is taken into consideration. On a philosophical level a revaluation of the concept of matter can lead to a different sort of identity theory.

Biological Evolution↗
PubMed1997

Proton magnetic resonance spectroscopy in brain white matter disorders.

The advent of magnetic resonance imaging (MRI) has revolutionized the clinical approach to the evaluation of brain white matter disorders and has contributed significantly to expansion of the concept of these diseases. MRI is very sensitive at detecting white matter lesions, but conventional T1 and T2-weighted images do not provide specific pathological information about the lesions, and correlation between MRI lesion load and clinical disability is often weak. Proton magnetic resonance spectroscopy can provide chemical-pathological information of a given tissue in vivo. The use of this MR technique in brain white matter disorders has shown to improve diagnostic classification and to provide surrogate measures useful for monitoring disease evolution and response to therapeutic intervention.

Acquired Immunodeficiency Syndrome↗
PubMed1979

Examination of the metabolism of oedematous brain tissue. V. The metabolism of oedematous white matter from rabbit brain.

Glucose and gas metabolism as well as water, sodium, and potassium content of normal and oedematous white matter slices of rabbit brain have been determined. A cutting technique for the preparation of the slices is described. Although the increase of the relative water content in oedematous white matter is much more pronounced than in oedema of the grey matter, we observed only one significant change: the pyruvate production in vitro is about 20% higher in slices prepared from oedematous brain.

Animals↗
PubMed1988

Magnetic resonance imaging of normal and pathological white matter maturation.

Fifty children between 3 months postnatal and 16 years of age were examined by means of a 1.5 T superconductive magnet, run at 0.35 and 1.0 T. The myelination was studied qualitatively and quantitatively (relaxation times, proton densities, image contrast). With increasing age, a decrease of T1 and proton density of white matter was found, which was complete at one year of age. In regions with a slow progression of myelination, gray/white matter contrast showed an increase up to the end of the first decade. Pathological white matter maturation was diagnosed either as an abnormal transformation of myelin (characterized by abnormal relaxation values), or as a deficient or delayed myelin formation (in comparison with age-matched controls).

Adolescent↗
PubMed2000

Tissue tears in the white matter after lateral fluid percussion brain injury in the rat: relevance to human brain injury.

A characteristic feature of severe diffuse axonal injury in man is radiological evidence of the "shearing injury triad" represented by lesions, sometimes haemorrhagic, in the corpus callosum, deep white matter and the rostral brain stem. With the exception of studies carried out on the non-human primate, such lesions have not been replicated to date in the multiple and diverse rodent laboratory models of traumatic brain injury. The present report describes tissue tears in the white matter, particularly in the fimbria of Sprague-Dawley rats killed 12, 24, and 48 h and 7 days after lateral fluid percussion brain injury of moderate severity (2.1-2.4 atm). The lesions were most easily seen at 24 h when they appeared as foci of tissue rarefaction in which there were a few polymorphonuclear leucocytes. At the margins of these lesions, large amounts of accumulated amyloid precursor protein (APP) were found in axonal swellings and bulbs. By 1 week post-injury, there was macrophage infiltration with marked astrocytosis and early scar formation. This lesion is considered to be due to severe deformation of white matter and this is the first time that it has been identified reproducibly in a rodent model of head injury under controlled conditions.

Amyloid beta-Protein Precursor↗
PubMed2001

Development and validation of capillary electrophoresis for the determination of selected metal ions in airborne particulate matter after sequential extraction.

A capillary electrophoresis (CE) method has been developed and validated for the determination of the distribution of metals in particulate matter after three-stage sequential extraction. Fe(II), Zn(II), Cu(II), Mn(II), and Cd(II) ions were separated using a background electrolyte consisting of 200 mmol L(-1) ammonium acetate (pH 5.5), 0.5 mmol L(-1) 1,10-phenanthroline, 10 mmol L(-1) hydroxylamine hydrochloride, and 20% acetone. The method was validated with respect to specificity, linearity, detection limits, precision, and accuracy. Detection limits are at sub-microg L(-1) levels (tens of microg g(-1) of particulate matter) using pressure injection. The analytical procedure was checked by analyzing a standard reference material, NIST SRM 1648 Urban Particulate Matter.

Air Pollutants↗
PubMed2003

Evaluation of the efficiency of extraction of PAHs from diesel particulate matter with pressurized solvents.

Pressurized Fluid Extraction (PFE) was evaluated for the extraction of polycyclic aromatic hydrocarbons (PAHs) and nitro-derivatives from diesel particulate matter. Extraction conditions were set up by performing several tests in which temperature, solvent strength, pressure, and static time were gradually increased. The results obtained on a laboratory test material made of a "lean" (low content of soluble fraction) Diesel particulate matter indicate that very severe conditions were needed in order to obtain better recoveries of the higher molecular weight molecules. Moreover, extraction efficiency seems to be influenced by the amount of soluble matter in the particulate, so that a "lean" particulate appears more difficult to extract. Recoveries of the deuterated standards of certain PAHs (i.e. indeno[1,2,3- cd]pyrene) were incomplete even with the toughest conditions tested. Experiments carried out on a certified material (SRM 1650 from NIST) also indicate that PFE can perform a better extraction of some of the PAHs than the method used for certification, but still incomplete. Comparison of results obtained on the SRM with different extraction techniques suggests that the composition of the extract varies considerably with the extraction technique and conditions. It is relevant to notice that recent Diesel engines produce leaner particulate: for future materials more drastic extraction conditions will be required.

Chemical Fractionation↗
PubMed2002

Progressive white-matter disease with primary cerebellar involvement: a separate entity?

Abstract. Although its metabolic basis has not yet been clarified, we report a progressive white-matter disease in a Turkish girl, starting in the cerebellum and spreading to supratentorial white matter. The onset was at the age of 2.5 years with diabetes insipidus, followed by ataxia and pyramidal signs resulting in loss of walking. Aqueduct stenosis was first recognised at the age of 8 years. To our knowledge, this MRI and clinical pattern does not correspond to a recognised, well-defined white-matter disease and may indicate a separate entity.

Age of Onset↗
PubMed2003

A case of Salla disease with involvement of the cerebellar white matter.

Salla disease (SD) is a lysosomal disorder manifesting in infancy with hypotonia, nystagmus, ataxia and retarded motor development. MRI typically shows hypomyelination confined to the cerebral white matter. We describe a patient with two MRI studies in addition to repeated urine examinations. This case was problematic because the first urine examination did not show the elevation of free sialic acid typical of SD and MRI was also atypical, with abnormal signal intensity in cerebellar white matter. We recommend repeated urinary examinations and a search for SLC17A5 mutations in patients with cerebral signal intensity abnormalities typical of SD and emphasise that cerebellar white-matter involvement on MRI does not exclude the diagnosis.

Cerebellum↗
PubMed2003

Three-dimensional white matter tractography by diffusion tensor imaging in ischaemic stroke involving the corticospinal tract.

Diffusion tensor MR imaging (DTI) provides information on diffusion anisotropy, which can be expressed with three-dimensional (3D) white matter tractography. We used 3D white matter tractography to show the corticospinal tract in eight patients with acute or early subacute ischaemic stroke involving the posterior limb of the internal capsule or corona radiata and to assess involvement of the tract. Infarcts and the tract were shown simultaneously, providing information on their spatial relationships. In five of the eight patients, 3D fibre tract maps showed the corticospinal tract in close proximity to the infarct but not to pass through it. All these patients recovered well, with maximum improvement from the lowest score on manual muscle testing (MMT) up to the full score through rehabilitation. In the other three patients the corticospinal tract was shown running through the infarct; reduction in MMT did not necessarily improve favourably or last longer, other than in one patient. As 3D white matter tractography can show spatial relationships between the corticospinal tract and an infarct, it might be helpful in prognosis of gross motor function.

Aged↗
PubMed2005

Analysis of the brain-stem white-matter tracts with diffusion tensor imaging.

The authors have reviewed the diffusion tensor imaging (DTI) of the brain stem in 19 subjects, consisting of 15 normal volunteers and four multi-system atrophy patients. The study was performed with 1.5 T MRI scanners. DTI was correlated with an automated program allowing superposition of the structural anatomy. Axial, sagittal, and coronal images demonstrated major white-matter fibers within the brain stem, including cortico-spinal tracts, transverse pontine fibers, and medial lemniscus. Smaller fibers, such as medial longitudinal fascicles and central tegmental tracts are difficult to visualize. To identify the anatomical orientation of the brain stem, white-matter fibers will help us understand the different functional disease processes, and DTI will play an important role for the evaluation of the different white matter fibers in the brain stem.

Adult↗
PubMed2006

White matter abnormalities in the anterior temporal lobe suggest the side of the seizure foci in temporal lobe epilepsy.

INTRODUCTION: White matter abnormalities in the anterior temporal lobe (WAATL) are sometimes observed on magnetic resonance (MR) images of patients with temporal lobe epilepsy (TLE). Our purpose was to determine whether WAATL could indicate if the seizure foci are ipsilateral on electroencephalograms (EEG) in TLE patients. METHODS: We reviewed 112 consecutive patients with medically intractable TLE. We compared the side of seizure foci on EEG (preoperative and intraoperative) and MR images. RESULTS: Both loss of gray-white matter demarcation and increased signal intensity changes in the anterior white matter (positive WAATL) were observed in 54 of 112 patients (48.2%) with TLE. WAATL were present on the same side as the seizure foci on preoperative intracranial EEG with subdural electrodes (iEEG) and on intraoperative electrocorticography (ECG) in all the patients. In 47 patients, MR images showed WAATL and focal lesions that were possibly epileptogenic for TLE. In 2 of the 47 patients, the seizure foci on iEEG and ECG were contralateral to the focal lesion; in the remaining 45 patients, the seizure foci on surface EEG (sEEG) and ECG and the focal lesion were on the same side. In three patients, no focal lesions were seen but WAATL were present on the same side as the seizure foci on sEEG and ECG. In four patients, MR images showed focal lesions for which epileptogenicity was questionable, and WAATL on the same side as the seizure foci on EEG. CONCLUSION: WAATL are clinically useful because they indicate the side of the seizure foci.

Adolescent↗
PubMed2000

Magnetisation transfer ratio is low in normal-appearing cerebral white matter in patients with normal pressure hydrocephalus.

We measured the magnetisation transfer ratios (MTR) of normal-appearing rostral (PR) and caudal (PC) periventricular white matter, the genu (CG) and the splenium (CS) of the corpus callosum and the thalamus (TH) in 12 patients with normal-pressure hydrocephalus (NPH) and compared them with 16 healthy control subjects. We found a significantly lower MTR in the NPH group than in the normal group for PR, PC, CG, and CS but not for TH. MT measurements give additional information which cannot be gained by conventional MRI, suggesting that NPH is associated with diffuse white matter damage, even in normal-appearing cerebral white matter.

Adult↗