Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MATTER”

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 1,423 records · Page 79Linked to original sources
PubMed1992

Resolution of cerebral white matter lesions following long-term penicillamine therapy for Wilson's disease: report of a case.

Although lenticular gray matter lesions in Wilson's disease (WD) may resolve following long-term decoppering therapy, response of cerebral white matter lesions to such a treatment has not been reported. A patient with WD developed dystonia of the left hand and focal seizures involving the left upper limb with occasional generalization. CT disclosed a low density area in the right frontal white matter. Initiation of penicillamine therapy resulted in worsening of clinical manifestations, further extension of the right frontal lesion, and development of a new left parietal lesion. However, after five years of continued penicillamine therapy, clinical improvements were noted, including disappearance of the left parietal lesion and almost complete resolution of the right frontal lesion. The present case suggests that cerebral white matter lesions in WD may also respond to long-term chelating therapy.

Adult↗
PubMed1978

Experimental spongy degeneration of the white matter induced by 6-aminonicotinamide intoxication.

Spongy state and degeneration of the white matter in the 6-aminonicotinamide intoxicated rats were studied neuropathologically and electromicroscopically. Young albino rats, four weeks of age, received 0.1% of 6-aminonicotinamide solution intraperitoneally as a single dose of 10 mg/Kg of body weight. Four hours after the administration, paralysis of the hind limbs occurred in the rats. Neuropathological investigations revealed a characteristic spongy and degenerative change of white matter as well as gray matter of the central nervous system. Corpus callosum, cerebellar cortex, and optic nerves showed edematous and spongy degeneration in the early stage of the experiment. Ultrastructural changes of myelin sheath were initially seen in the vicinity of severely damaged oligodendrocytes. The vacuoles in the myelin, i.e. intramyelinic vacuoles, were formed by splitting between the innermost myelin lamellae and axon. Axons remained usually unchanged in the early stage. The pathogenesis of ultrastructural changes of the white matter in the 6-aminonicotinamide intoxication was discussed.

6-Aminonicotinamide↗
PubMed2004

Anatomic dissection tractography: a new method for precise MR localization of white matter tracts.

BACKGROUND AND PURPOSE: Several white matter tracts in the brain cannot be identified on MR studies because they are indistinguishable from the surrounding white matter. We sought to develop a method to precisely localize white matter tracts by correlating anatomic dissections with corresponding MR images. METHODS: MR imaging was used to guide anatomic dissection of the uncinate fasciculus. Formalin-preserved brains were imaged before and after several stages of dissection. Progressive dissection was guided by using volume-rendered and cross-sectional images of the dissected specimens. To precisely define the location of a tract, its surface was traced on the corresponding three-dimensional MR image of the dissected specimen. MR images of the dissected and intact specimens were coregistered to allow the tracings to be projected onto multiplanar reformatted images of the intact specimen. RESULTS: The uncinate fasciculus in the anterior temporal lobe and external and extreme capsules was dissected without destroying adjacent structures. Coregistration of the MR images from intact and dissected specimens permitted precise MR identification of the surface of this tract. These methods were successful for two additional tracts. (The dissected anatomy, MR anatomy, and clinical examples of the three tracts are described in a companion article.) CONCLUSION: MR-assisted anatomic dissection permits limited removal of brain tissue so that important anatomic and surgical relationships can be demonstrated on correlated MR studies. This method can be applied to other white matter tracts that are indistinguishable on MR studies and to situations in which anatomic validation of normal and abnormal diffusion tractographic studies is needed.

Adult↗
PubMed2004

[Multiple cerebral white matter lesions following head trauma with eyeball contusion].

We reported a 36-year-old man with multiple cerebral white matter lesions following head trauma with eyeball contusion. He had suffered from optic neuritis on non-injured side after one and half months from the head trauma. Brain MRI revealed multiple cerebral white matter lesions and lumbar puncture disclosed an elevated level of protein of the cerebrospinal fluid after two and half months from the head trauma. He was treated with steroid pulse therapy and resulted in an improvement of his visual acuity and a remarkable decrease of multiple cerebral white matter lesions. There has been a controversy concerning the causal relationship between trauma and multiple sclerosis (MS). In this case, MS-like multiple cerebral white matter lesions are considered to be relevant to the head trauma.

Adult↗
PubMed1992

[Arterial hypertension and pathology of cerebral white matter].

White matter of the brain in 25 autopsy cases with the stroke and chronic cerebro-vascular pathology produced by arterial hypertension (AH) was studied morphologically. Focal and diffuse changes of the white matter were found against the background of the hypertonic angiopathy. These changes were represented by lacunar infarcts, foci of incomplete necrosis, perivascular encephalolysis, more seldom by small haemorrhages in combination with edema, cribriform lesions and widespread spongiosis of the white matter. Alterations of the cortex-medullary arteries, microcirculatory bed, disturbances of the dynamics of liquor and permeability of blood-brain barrier play the most important role in the white matter damage. The authors distinguish 3 forms of this damage. The complex of these alterations is regarded as a morphological substrate of a vascular dementia associated with AH.

Adult↗
PubMed2004

Organic matter balance in ECF kraft mill fiberline.

Organic matter balances of an ECF kraft mill fiberline were studied in three different operational conditions of the oxygen delignification stage by implementing mill measurements, collecting routine mill data and combining them in a modified PROCELL steady state model. Dissolved volatile solids was the basic measurement for organic matter in liquid streams. Normal operation of the O2D0E(O)D1E(OP)D2 fiberline was described successfully. It was also possible to describe exceptional operating situations in the oxygen delignification stage and their effects on other parts of the production process reasonably well in order to focus studies on aspects requiring further attention. The existence of organic matter lost through complete degradation and volatile organic compounds in unit processes as well as its sensitivity to yield and operational situations is shown. The different perspectives of pulp production and wastewater treatment can be brought closer to each other using the approach in this study. The variation in the fractions discharged to wastewater treatment, although a relatively small share of the overall organic matter balance, will continue to become more important also for pulp production when effluent streams are increasingly turned back to the production line through further closure. Studies like the one presented here, can contribute to the evaluation of this development.

Industrial Waste↗
PubMed2003

[Comparative study of dissolved matter of glycyrrhizic acid before and after supermicro-pulverization of Radix Glycyrrhizae].

OBJECTIVE: To investigate various activities of dissolved matter of glycyrrhizic acid of Radix Glycyrrhizae and the powder by supermicro-pulverization. METHOD: The contents of glycyrrhizic acid in different samples were tested. RESULT: The dissolved matter of glycyrrhizic acid was greatly increased by supermicro-pulverization. The more time used for grinding, the smaller the size of the powder, and the easier the glycyrrhizic acid would be dissolved. CONCLUSION: Supermicro-pulverization is helpful to the dissolved matter of glycyrrhizic acid of Radix Glycyrrhizae, and the size of powder exerts great influence on dissolved matter of glycyrrhizic acid.

Drug Combinations↗
PubMed2005

Diffusion abnormality of deep gray matter in external capsular hemorrhage.

BACKGROUND AND PURPOSE: To our knowledge, diffusion abnormality of the unaffected deep gray matter during striatocapsular hemorrhage has not been previously described in the literature. We report the presence of the diffusion abnormality separated from hematoma in patients with external capsular (lateral striatocapsular) hemorrhage and suggest the plausible mechanisms of diffusion signal intensity change. METHODS: We retrospectively reviewed MR images in 28 consecutive patients with spontaneous striatocapsular hemorrhage and evaluated signal intensity changes at sites separated from the hemorrhage and the lesions on diffusion-weighted (DW) images. Apparent diffusion coefficients (ADCs) of the lesions were measured, and volume changes in the deep gray matter were assessed at follow-up. RESULTS: On DW images, hyperintensity of deep gray matter was found in nine patients (25%). In all patients with DW imaging abnormality, the hemorrhage was located in the external capsule, and the interval from hemorrhagic ictus to MR imaging study was 8-54 days. Hyperintensity of the deep gray matter was seen in the caudate (n = 8), putamen (n = 7), thalamus (n = 5), and substantia nigra (n = 2). Mean relative ADC ratios of the diffusion abnormality were 0.76 +/- 0.10 in the caudate, 0.79 +/- 0.07 in the putamen, and 0.85 +/- 0.11 in the thalamus. DW imaging abnormality disappeared with mild atrophy in two patients who underwent follow-up imaging. CONCLUSION: External capsular hemorrhage may be uncommonly accompanied by diffusion abnormality in the striatum or thalamus at follow-up, and the lesion should not be misdiagnosed as new-onset infarction. Secondary neuronal degeneration may play an important role in the development of diffusion abnormality.

Adolescent↗
PubMed2005

Ex vivo evaluation of ADC values within spinal cord white matter tracts.

BACKGROUND AND PURPOSE: Our purpose was to evaluate the effect of fixative on apparent diffusion coefficient (ADC) values and anisotropy within spinal cord white matter. As glutaraldehyde (GL) better preserves axonal ultrastructure as compared with paraformaldehyde (PF), we hypothesize that spinal cord white matter fixed with GL will have increased anisotropic water diffusion as compared with specimens fixed with PF. METHODS: Eleven rats were perfusion-fixed with either 4% PF or a combination of 2.5% GL and 4% PF. Diffusion-weighted imaging of the ex vivo spinal cord was performed using a 9.4T magnet with b values up to 3100 s/mm(2). In-plane resolution was 39 mum x 39 mum, and section thickness was 500 mum. RESULTS: Overall, animals fixed with a combination of GL and PF (GL-PF) showed a greater increase in longitudinal ADC (lADC) as compared to those fixed with PF only, without differences in transverse ADC (tADC). As a consequence of the increased lADC, overall anisotropic diffusion increased in those animals fixed with GL-PF, as measured with an anisotropy index (AI = tADC/lADC). Evaluation of specific tracts demonstrated that lADC for animals fixed with GL-PF were significantly elevated in the rubrospinal, vestibulospinal, and reticulospinal tracts as compared with animals fixed with PF only. CONCLUSION: Using a fixative of GL-PL results in increased anisotropy (decreased AI values) in spinal cord white matter tracts, as compared with PF fixation only, largely owing to increases in the lADC values. This finding may be due to better fixation of intra-axonal cytoskeletal proteins that results when GL is combined with PF and sheds further light on underlying sources of anisotropic water diffusion in CNS white matter.

Animals↗
PubMed2004

[Factors of effects on transformation behaviors of inorganic mineral matters in desulfurizing process of burning coal].

The Heshan coal and the Wansheng coal were selected to investigate the effects of Ca/S molar ratio, combustion temperature and other factors on the desulfurization efficiency when limestone as a desulfurizer. And then the possible effects of various desufurizing systems on the mineral constituents of their residues were discussed by using the X-ray diffraction analyzer. Moreover, the phase diagrams of the ternary system CaO-Al2O3-SiO2 were further used in order to find out the transformation behaviors of inorganic mineral matters in the desulfurizing processes of burning coal on the basis of the XRD results. The results show that the combustion temperature and the Ca/S molar ratio are the key factors affected the desulfurization efficiency and their residues' mineral constituents. When the temperature raised and the Ca/S ratio increased, the solid-phase reactions between CaO and some inorganic matters in coal ash will be obviously accelerated, which thus are good for the formaion of many mineral matters such as C4AF,C2AS and beta-C2S. Yet the anhydrite formed will decompose if the temperature is above 1050 degrees C and then the desulfurization efficiency will decrease. The desulfurization efficiency in different temperature is mainly decided by the existence form of the sulfur-contained mineral matters and their contents in the residue. In the experiment, the best desulfurization efficiency for the HS coal was about 90% when the Ca/S ratio was 2 or 3 and the range of the temperature was from 850 degrees C to 950 degrees C.

Air Pollutants↗
PubMed2005

Sorption of dissolved organic matter and its effects on the atrazine sorption on soils.

The dissolved organic matter (DOM), water soluble organic matter derived from sewage sludge was separated into hydrophobic fraction (Ho) and hydrophilic fraction (Hi). The sorption of DOM and its fractions on soils and the effects of DOM sorption on a nonionic pesticide (atrazine(2-chloro-4-ethylamino-6-isopropylamino-1,3,5-trazine)) distribution between soil and water were investigated using a batch equilibrium technique. The total DOM sorption on soils described by the Langmuir equation reached saturation as the DOM concentration increased. The sorption of Ho fit the Freundlich model. In contrast, a negative retention evidently occurred as adding Hi at higher level in tested soils. The sorption of Ho dominated the total DOM sorption and the release of soil organic matter (SOM). Effects of DOM on the atrazine sorption by soils were DOM-concentration dependent and dominated by the interaction of atrazine, DOM, and soil solids. Generally, the presence of DOM with lower concentration promoted atrazine sorption on soils, namely the apparent partitioning constant (Kd) for atrazine sorption in the presence of DOM was larger than the distribution constant (Kd) without DOM; whereas the presence of DOM with higher concentration inhibited atrazine sorption (i.e., Kd < Kd). The overall effects of DOM on atrazine sorption in soils might be related to the DOM sorption and the release of soil intrinsic organic matter into aqueous solution. The sorption of Ho on soils promoted the atrazine sorption on soil, while the release of SOM by Hi and the competitive sorption between Hi and atrazine on soil surface led to a decrease of atrazine sorption. Information provided in this work may contribute to a better understanding of the DOM sorption and its impacts on the contaminant soil-water distribution.

Adsorption↗
PubMed2005

[Dynamics of soil active organic matter in Chinese fir plantations].

Soil active organic matter is the main source of soil nutrients, and plays an important role in the formation and stabilization of soil aggregate. Chinese fir (Cunninghamia lanceolata) is the most important fast-growing timber tree species in southern China, but its continuous plantation has caused soil deterioration. The study on the active fractions of soil organic matter under the first and second generation plantations of Chinese fir and the native broad-leaved forest at Huitong Experimental Station of Forest Ecology, Chinese Academy of Sciences, in Hunan Province showed that their contents were higher under native broad-leaved forest than under Chinese fir plantations, and higher under the first than under the second generation plantation. The content of soil active organic carbon (SAOC), microbial biomass carbon (MBC), water-soluble organic carbon (WSOC) and water-soluble carbohydrate (WSC) was 18.79 g x kg(-1), 421.7 mg x kg(-1), 252.2 mg x kg(-1) and 136.3 mg x kg(-1) under the first generation plantation of Chinese fir, and 22.31 g x kg(-1), 800.5 mg x kg(-1), 361.1 mg x kg(-1) and 220.1 mg x kg(-1) under the native broad-leaved forest, respectively. The corresponding values under the second generation plantation of Chinese fir were 73.6%, 87.9%, 66.3% and 53.2% of those under the first generation plantation of Chinese fir. The results also indicated that there existed some extent correlations among the active fractions of soil organic matter, and higher correlations between soil microbial biomass carbon and other active fractions of soil organic matter.

Carbon↗
PubMed2005

[Diffusion tensor tracking of cerebral white matter fibers: a preliminary study].

OBJECTIVE: To study the efficacy of diffusion tensor tracking (DTT) in study of the normal and abnormal cerebral white matter fiber. METHODS: Ten normal adult volunteers, 5 males and 5 females, aged 40.9 (24-65), and 28 patients with cranial tumors, 9 males and 19 females, aged 43.0 (11-77), underwent MR diffusion tensor. The data thus obtained were transferred to a personal computer and processed with dTV. RESULTS: The main cerebral white matter fiber pathways were successfully observed. Association fibers, including arcuate fibers, cingulum, superior and inferior longitudinal fasciculus, and inferior fronto-occipital fasciculus, commissural fibers (corpus callosum), and projection fibers (corticospinal tract) were revealed. The arcuate fibers, cingulum, superior and inferior longitudinal fasciculus, corticospinal tract, external capsule, optic radiation, and corpus callosum were all involved by intracranial tumors. The abnormality of cerebral white matter could be classified into 4 groups: disruption + infiltration (7 cases), disruption + displacement (10 cases), infiltration + displacement (3 cases), and displacement (8 cases). CONCLUSION: DTT is useful for showing the main normal and abnormal cerebral white mater fiber tracts, thus opening a new field foe research of cerebral white matter fiber in vitro.

Adolescent↗
PubMed2005

Using respirometer in biodegradation phenomenon of natural organic matters.

This study conducted in monitoring respirometer oxygen consumption of aerobic microorganism during biodegradation processes of ozonated organic matters, which can estimate both biodegraded efficiency and coefficient of natural organic matters (NOMs) in water source. It can be proposed that different ozone dosage might change biodegradation characteristics of organic matters. The result reveals that higher ozone dosage may cause higher biomass yield coefficient of microorganism, and cultured microorganism may easily utilize biodegradation organic matters (BOMs) produced by ozonation, finally increasing overall removal efficiency. Therefore, using respirometer to evaluate the production of BOMs by ozonation before the biological treatment is effective for controling ozone dosage and enhancement of NOMs removal by biological processes.

Bacteria, Aerobic↗
PubMed2005

Fluorescence characteristic changes of dissolved organic matter during municipal solid waste composting.

Dissolved organic matter(DOM) of municipal solid waste (MSW) consists of minerals, water, ash and humic substances, and is known to enhance plant growth. In this study, inoculating microbes (ZJ, MS) were used in municipal solid wastes composting, and composting implemented a industrialized technology. During composting, dissolved organic matter was extracted from the compost and purified. The spectral characteristics of dissolved organic matter was determined by fluorescence emission, excitation, and synchronous spectroscopy. Fluorescence emission, excitation, and synchronous spectra characterized by different relative fluorescent intensities and peaks over time. Fluorescence spectra were similar to that of fulvic acid in sewage sludge, indicating the presence of dissolved organic matter with aromatic structures and a high degree of molecular polymerization. Compared with the controls with no microbial inoculation, the microbe-inoculated treatments exhibited the increase of aromatic polycondensation, in the following order: MS + ZJ > ZJ > MS > CK.

Bacteria, Aerobic↗
PubMed2006

[Influence of mineral matter on sulfur conversion in coal during combustion].

Three species micro-pulverized coals(Hegang, Tiefa, Zhungeer coal) were studied, the mineral matters (MgO, CaO, Al2O3 and Fe3O4) were respectively added to the coals. The combustion of samples were studied to investigate the effect of mineral matter on transformation of sulfur during combustion by the combined of DTG and GC-MS, the flowmeter 50 mL/min, heating rate 20 degrees C/ min, oxygen volume percentage 20% . The SO2 release curve of primitive micro-pulverized coal appear three peaks during the combustion, but the demineralized sample appear two peaks. The species of coal has effect on temperature of the maximum release rate of SOz, the release rate of SO2 of Hegang coal is even in three temperature ranges, Tiefa coal appear maximum value about 500 degrees C and Zhungeer coal about 200 degrees C which probably due to the different amount of all kinds of sulfur in primitive coal sample. The mineral matter (MgO, CaO, Al2O3 and Fe3O4) have sulfur retention and catalyzing effect on SO2 the combustion of coal. The amount and species of mineral matter and species of coal determine the sulfur retention effect.

Air Pollution↗
PubMedDate not supplied

The morphologic correlate of incidental punctate white matter hyperintensities on MR images.

Postmortem examinations were made of the brains of six patients, 52-63 years old, who exhibited incidental punctate white matter hyperintensities on MR images before death. Our aim was to unravel the morphologic correlate of such lesions. By repeating the MR study after fixation on four specimens, cutting the brain parallel to the MR imaging plane, and examining whole-hemisphere microscopic sections, we optimized lesion identification. The white matter signal abnormalities were better delineated on pre- than postmortem scans, and visual inspection of the brain slices was normal in all but one location. Histologically, we found areas of reduced myelination with atrophy of the neuropil around fibrohyalinotic arteries as well as different stages of perivenous damage. The latter ranged from spongiform transformation of the neuropil and scattered foci of demyelination to large perivenous areas with marked rarefaction of myelinated fibers. Edematous glial swelling in foci of ganglion cell heterotopia caused subcortical white matter hyperintensities in one case. Our results suggest minor perivascular damage but not infarction as the most likely substrate of punctate MR white matter hyperintensities in elderly brains. Histologic correlations with MR images obtained during life or with studies of unfixed material are necessary to analyze such small lesions.

Brain↗
PubMed1990

[A case of membranous lipodystrophy (Nasu) with diffuse cerebral white matter involvement and cerebellar atrophy on brain CT and MRI].

A 37-year-old female was admitted to our hospital because of progressive dementia and gait disturbance. She was healthy until 34 years of age when she had difficulty in walking and memory disturbance with personality changes. At age 36, she developed urinary incontinence and dementia. The neurological examination demonstrated euphoric mental state, emotional incontinence, severe dementia, paraplegia, dysmetria, choreic movements in both arms and urinary incontinence. Diffuse hyperreflexia and bilateral Babinski signs were observed. Routine laboratory examination showed slightly increased erythrocyte sedimentation rate and alkaline phosphatase. Electroencephalogram revealed diffuse irregular slow waves. X-ray film of the ulnar bone revealed osteoporotic and cystic lesions. The biopsy of the left tibial bone showed a specific membranous cystic structure. Computerized tomography (CT) of the brain showed symmetric, diffuse low density areas in the cerebral white matter and severe atrophy of the cerebellum. T2-weighted magnetic resonance imaging (MRI) revealed diffuse high intensity areas in the cerebral white matter. The present case is characterized by diffuse changes in cerebral white matter and cerebellar atrophy, which have been never reported in Nasu-Hakola disease. The diffuse cerebral white matter changes shown by CT and MRI appear to indicate that this patient is the first case of leukodystrophy of sudanophilic type since the original case reported by Nasu et al.

Adult↗