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 523 records · Page 29Linked to original sources
PubMed2004

[Correlation between age and average apparent diffusion coefficient in normal-appearing cerebral white matter].

OBJECTIVE: To quantitatively study the effect of ages on the average apparent diffusion coefficient (ADCav) of normal-appearing white matter. METHODS: Fifty patients with normal-appearing white matter were divided into four age groups, namely 16-30 years, (n=13), 31-45 years (n=12), 46-60 years (n=14) and >60 years (n=11). All the subjects were examined with conventional and trace-weighted diffusion imaging in three orthogonal directions. The ADCav of the white matter was measured and compared between various age groups. RESULTS: In the white matter, the ADCav of all the patients was (0.71+/-0.08) x 10(-3) mm2/s; the ADCav of the white matter in the first to fourth age groups were (0.69+/-0.06) x 10(-3) mm2/s, (0.71+/-0.07) x 10(-3) mm2/s, (0.71+/-0.09) x 10(-3) mm2/s, and (0.73+/-0.10) x 10(-3) mm2/s respectively. ADCav of patients between 16-30 years was significantly different from that of patients over 60 years of age (P=0.014). Patients older than 60 years had an ADCav of the white matter significantly higher than the value of (0.70+/-0.07) x 10(-3) mm2)/s in the total patients younger than 60 years (P=0.026). CONCLUSION: Water diffusibility shows a slight increase in human white matter with aging, possibly due to mild ultrastructural changes associated with aging.

Adolescent↗
PubMed2006

[Studied of dry matter accumulation and echinacoside content of Cistanche tubulosa in Huabei plain].

OBJECTIVE: To give some theory support of Cistanche tubulosa cultivation by searching dry matter accumulation and echinacoside content of C. tubulosa. METHOD: Dry matter accumulation content of C. tubulosa culturing in Huabei plain was analysed in different growth season of C. tubulosa. Echinacoside content was determined by HPLC. RESULT: Dry matter accumulation of C. tubulosa showed "S" variation. Dry matter accumulation increased fastest in September among growing seasons. Dry matter amount was 138.58 g after C. tubulosa grew a year. Dry matter amount decreased significantly along with inoculation time retarded. Echinacoside content was 30.59% when C. tubulosa grew in 5 months, decreased guadully after that, and 9.76% in annual. CONCLUSION: Variation rule of dry matter accumulation and echinacoside content was found in C. tubulosa that grew one year in Huabei plain.

Biomass↗
PubMed1991

[Relation between cerebral white matter damage on CT and MRI and clinical data in DRPLA (pseudo-Huntington form)].

We studied the relation between cerebral white matter damage and clinical data in nine patients with dentatorubropallidoluysian atrophy (DRPLA). All patients showed pseudo-Huntington form. The study produced five results. (1) The four of the nine patients showed diffuse hypodensity of the cerebral white matter on CT. We studied one of this four patients by MRI. The hypodensity area on CT showed marked high signal intensity by T2-weighted image on MRI. (2) The onset age was later in the patients with cerebral white matter damage as compared with the patients without this damage. (3) All patients showed subcortical dementia, which was more remarkable in the patient with white matter damage. This suggests the relation between cerebral white matter damage and progression rate of subcortical dementia in DRPLA. (4) Gait disturbance progressed more rapidly in the patients with cerebral white matter damage. (5) The homovanillic acid (HVA) and 5-hydroxyindole acetic acid (5-HIAA) concentration in CSF decreased more remarkably in the patients with white matter damage.

Adult↗
PubMed1978

[Measurement of spinal cord blood flow in rabbits: central gray matter flow and CO2 reactivity (author's transl)].

Spinal cord blood flow (SCBF) was measured in 20 rabbits anesthetized with sodium pentobarbital. The platinum electrodes (0.3 mm in diameter) were inserted into the central gray matter of the thoracic spinal cord (Th8-10). In all animals, blood pressure and pAO2 remained constantly in the normal range. The pACO2 was changed by ventilation. Blood gases were checked both before and after each spinal cord blood flow measurement. The results are as follows. 1. Seventy-three percent of the clearances recorded from the gray matter were monoexponential and in the white matter almost all were monoexponential. 2. The mean values of gray matter SCBF of all animals was 38.3 +/- 1.85 ml/100 g/min (SE) at normo-capnea and the white matter was 19.5 +/- 1.33 ml/100 g/min. 3. An almost linear relationship exists between the pACO2 and SCBF. The values were 0.62 ml/100 g/min/torr in the gray matter and 0.38 ml/100 g/min/torr in the white matter.

Animals↗
PubMedDate not supplied

Patterns of edema in tumors vs. infarcts: visualization of white matter pathways.

The computed tomographic (CT) scans of 339 patients with recent nonhemorrhagic cerebral infarct and 155 patients with supratentorial tumors were reviewed to evaluate the appearance of cerebral edema. White matter pathway edema characterized the CT pattern in 106 (68%) of the 155 tumor cases. In these 106 cases, there were 143 tumors, with edema in the arcuate white matter (73%), the external capsule (33%), the internal capsule (12%) and the corpus callosum (14%). In contrast, only four of the 339 cases of infarct had edema in the white matter pathways. In addition, 260 (77%) of the infarct cases had edema in both gray and white matter and 98% had at least gray matter involvement, while only two of the tumor cases had any gray matter edema. White matter pathway involvement with respect to tumor site is useful in differentiating tumor and infarct edema.

Brain Neoplasms↗
PubMed1995

Magnetization transfer imaging of periventricular hyperintense white matter in the elderly.

PURPOSE: To characterize with magnetization transfer imaging the pathologic substrate of the nonspecific periventricular hyperintense white matter changes seen on T2-weighted images of elderly patients. METHODS: Twenty-one elderly patients with periventricular hyperintense white matter on T2-weighted MR images and eleven control subjects were studied using MT technique. Magnetization transfer ratios (MTRs) were calculated for the periventricular hyperintense white matter and normal-appearing white matter. These MTRs were correlated with histopathologic changes that have previously been reported as well as with established MTRs for other lesions. RESULTS: The MTRs (mean, 35.2; SD, 1.2) in the periventricular hyperintense white matter are lower than those in the normal white matter of the patient (mean, 40.8; SD, 1.4) and control (mean, 41.3; SD, 1.8) groups. These MTRs are much higher than those of demyelinating lesions but are similar to those of experimental lesions with just edema. CONCLUSION: Because MTR may reflect to some extent histopathologic changes and thus provide more specificity than conventional pulse sequences, the main pathologic substrate accounting for the lower MTR in periventricular hyperintense white matter is probably the increased water content in reactive astrocytes.

Adult↗
PubMedDate not supplied

Neuro-Behçet disease with demyelination and gliosis of the frontal white matter.

A rare case of neuro-Behçet disease with diffuse demyelination and gliosis of the frontal white matter is reported clinico-pathologically. The disease began with genital ulcer and recurrent oral aphthosis when the patient was 42 years of age. There was erythema, moderate fever, CSF (cerebrospinal fluid)-pleocytosis and elevated CSF-globulin. He was diagnosed as having neuro-Behçet disease and treated with prednisolone. He gradually became euphoric, disinhibited, indifferent and demented. His cranial CT showed diffuse low density areas in the bilateral frontal white matter. He became bedridden, akinetic mute and died from respiratory dysfunction 3 1/2 years after onset. The following neuropathological findings were observed: 1) Moderate demyelination and gliosis was present mainly in the frontal and parietal white matter. 2) There were many micro-spongious necrotic foci in the gray and white matters of the cerebrum, basal ganglia, thalamus, midbrain and pons, some of which were accompanied by gliosis. 3) From 1/2 to 1/3 of all micro-necrotic foci in the frontal white matter were old and accompanied by gliosis. The white matter containing numerous micro-necrotic foci had myelin pallor and gliosis. 4) There was neither micro-necrosis nor gliosis in the occipital lobe. The pathogenetic correlation of white matter lesions with primary and secondary circulatory disturbances is discussed.

Atrophy↗
PubMed1994

White matter changes in patients with breast cancer treated with high-dose chemotherapy and autologous bone marrow support.

PURPOSE: To study MR changes in the white matter of the brain in patients with breast cancer treated with a widely used protocol of high-dose chemotherapy and autologous bone marrow support. METHODS: Thirteen patients with high-risk stage II or stage IV breast cancer treated with high-dose cyclophosphamide, cisplatin, carmustine, and bone marrow support underwent posttransplant MR examination of the brain. Serial posttransplant MR examinations were performed in 5 of the 13 patients and single MR examinations in 8. The severity of the white matter change was evaluated by two neuroradiologists and rated mild, moderate, or severe. RESULTS: In 9 of the 13 patients, central and peripheral cerebral white matter changes were observed. Four patients had severe changes, extending from the ependyma of the lateral ventricles to the gyri. An additional 4 patients had moderate white matter change at the last observation. One had mild change, and 4 had no white matter change. In all patients, there was sparing of inferior frontal, posterior inferior occipital, and anterior temporal lobes, and of the centrosylvian brain. CONCLUSIONS: White matter change occurred in patients treated with a high-dose chemotherapy and bone marrow support protocol. Most of the changes, and the more severe ones, occurred 5 or more months after the transplants. There was no apparent relationship between these changes and central nervous system function. Because of the increased longevity with this treatment, it is important to appreciate these white matter changes, recognizing however that their expression may be subclinical.

Adult↗
PubMed1994

[Investigation of involvement of cerebral white matter in DRPLA--including MRI perfusion study].

Clinical, radiological, and histological examinations were performed on eight patients with autosomal-dominant dentato-rubro-pallido-luysian atrophy (DRPLA) including an autopsy case, to investigate the abnormal findings of the cerebral white matter in DRPLA. Three of the eight patients were found to have diffuse low density on CT or diffuse high-signal areas on T2-MRI in the white matter of the brain. There were no correlations between abnormal findings in the white matter and the following factors; age of onset, duration of the disease, clinical manifestations, disease severity, Hachinski score, or EEG abnormality. Single-photon emission tomography failed to reveal any relative decrease in cerebral blood flow in the white matter, even in the three patients with abnormal findings in the white matter. MRI perfusion studies did not suggest any decrease in cerebral blood volume in any of the patients examined, but in the DRPLA patients the latency, i.e., the interval from the time of injection to the time of the minimum signal intensity, was significantly prolonged in comparison with the results in normal controls. On histopathological investigation, there was diffuse decreased staining in the centrum semiovale and deep white matter of the temporal lobes bilaterally, but no gliosis, or arteriolar thickening or hyalinization were detected. These findings confirmed that the lesions in the white matter in DRPLA are not attributable to cerebral ischemia. The abnormal findings are presumably the result of the degeneration which occurs in DRPLA itself.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1997

Neurite growth-inhibitory activity in the adult rat cerebral cortical gray matter.

Axon growth-promoting and -inhibitory molecules are likely to work in concert to promote and guide axons in vivo. In adult mammals, inhibitory molecules associated with myelin in the white matter of the central nervous system (CNS) play an important role in the failure of long-distance axon regeneration. The presence of neurite growth-inhibitory molecules in the adult rat gray matter has not been extensively studied. In this article we describe work on the characterization of neurite growth-inhibitory activity in the adult rat cerebral cortical gray matter using various biochemical and cell culture approaches. We show using a neuronal cell line (NG108-15 cells) that neurite growth-inhibitory activity is present in membrane preparations of the cortical gray matter. Purified gray matter membranes also induce growth cone collapse of cultured embryonic rat dorsal root ganglion neurons. The inhibitory activity in the membrane preparations is extractable with 3-[(3-cholamidoprophyl)-dimethylammonio]-1-propane-sulfonate, but does not appear to be depleted by various lectins. Western blots and enzyme treatments showed that the inhibitory effect of the gray-matter preparations is not likely to be mediated by myelin-associated inhibitors or chondroitin sulfate proteoglycans. However, tenascin was detected in these samples and may contribute to some of the inhibitory activity. Selective separation of the inhibitory molecules can be achieved by ion-exchange chromatography, which also suggests the presence of multiple inhibitors in cortical gray matter membranes.

Animals↗
PubMed1998

[Developmental plasticity of corticospinal projections in the spinal cord gray matter of normal and hemicortectomized rat].

In the previous study we demonstrated in rats that aberrant ipsilateral CST fibers were increased when the cerebral cortex was surgically ablated unilaterally during the neonatal period. Origin of these aberrant fibers was confirmed to involve collateral axons, ramified from their parent axons. In this study, possible plastic change and the critical period for the outgrowth of CST fibers into the spinal cord gray matter in the rat after unilateral (right side) cortical damage at different ages measured in days were examined using anterograde horseradish peroxidase (HRP). HRP was injected into the left sensorimotor cortex in both normal and experimental rats. In the normal control rats, the outgrowth of HRP positive axons into the spinal gray matter was first noticed at 7 day of age in the vicinity of the right dorsal funiculus, and then reached maximal density and extension at 10 and 14 days of age, respectively. From 21 days onwards, the density and extension of HRP positive axons in the gray matter decreased rapidly except in the medial part close to the dorsal funiculus. In rats whose right cerebral cortex were damaged at day 1 of age, the pattern of the outgrowth of HRP positive axons into the right gray matter was much the same as that in age-matched controls. However, significantly different from the control, many HRP positive axons were noted even in the contralateral gray matter. HRP-positive axons in the contralateral left gray matter were also abundant in the rats who sustained cortical damage at 7 and 14 days, but were decreased considerably when the cerebral cortex was damaged at 28 days of age. When damage occurred at 56 days of age, HRP-positive axons did not increase in the left gray matter, indicating that the critical period of axonal plasticity after localized damage was before 4 weeks of age in rats.

Animals↗
PubMed1995

Computed tomography--but not magnetic resonance imaging--identified periventricular white-matter lesions predict symptomatic cerebrovascular disease in probable Alzheimer's disease.

OBJECTIVE: To examine the clinical consequences of periventricular white-matter lesions on computed tomography (CT) and magnetic resonance imaging (MRI) scans in probable Alzheimer's disease. DESIGN: Case series, 12-month follow-up. SETTING: Multidisciplinary behavioral neurology research clinic. PATIENTS: We longitudinally evaluated the clinical characteristics of 27 patients with probable AD for whom both CT and MRI scans had been performed at baseline. INTERVENTIONS: None. MAIN OUTCOME MEASURE: The presence of abnormal neurological signs was examined at baseline and at a 12-month examination. RESULTS: Periventricular white-matter lesions were observed with CT in 12 patients (44%) and with MRI in 21 patients (78%). Computed tomography did not detect lesions of 1 to 3 mm, as were seen on MRI scans, and CT also did not detect lesions of 4 to 10 mm when they occurred in the deep subcortical white matter and were not part of a greater confluent lesion. There was no relationship between the severity of periventricular white-matter lesions with either neuroimaging method and the presence of abnormal neurological signs. However, there was a greater frequency of periventricular white-matter lesions shown on CT scans than on MRI scans at baseline in patients in whom abnormal neurological signs (eg, abnormal gait, asymmetric deep tendon reflexes, focal motor deficits, abnormal plantar response) developed at 12-month follow-up. CONCLUSION: Although MRI may be more sensitive in detecting periventricular white-matter lesions, CT is more specific in predicting subsequent symptomatic cerebrovascular disease.

Aged↗
PubMed2004

Severe cerebral white matter involvement in a case of dentatorubropallidoluysian atrophy studied at autopsy.

BACKGROUND: The pathophysiology of white matter involvement in dentatorubropallidoluysian atrophy (DRPLA) is controversial. Moreover, the clinical repercussions and evolution of these lesions have not been well documented. OBJECTIVE: To describe a case of DRPLA with severe cerebellar white matter involvement. DESIGN: Case report. Patient A 62-year-old woman with DRPLA. RESULTS: When the genetic diagnosis was made, the patient manifested severe ataxia, slight dysarthria, and subcortical cognitive impairment. Cranial magnetic resonance imaging showed atrophy of the cerebellum and brainstem and moderate high-intensity signal alterations in the periventricular cerebral white matter in T2-weighted sequences. In the following 5 years, she developed uncontrolled head movements associated with severe bruxism and tetraparesis, and became deeply demented. New magnetic resonance imaging showed severe diffuse cerebral white matter alterations in T2 sequences with only slight progression of brainstem and cerebellar atrophy. After her death at 67 years of age, the autopsy study showed diffuse myelin pallor, axonal preservation, and reactive astrogliosis in the cerebral white matter, with only mild atherosclerotic changes, and moderate neuronal loss in the cerebellum and brainstem. CONCLUSIONS: Leukoencephalopathy could be a prominent finding in some patients with DRPLA, explaining, at least in part, their clinical evolution. In our case, the disproportion between the severity of white matter damage and vascular changes does not support a cardinal role for ischemic mechanisms in leukoencephalopathy.

Female↗
PubMed1990

Preservation of normal cognitive functioning in elderly subjects with extensive white-matter lesions of long duration.

Although deep white-matter brain lesions are seen on magnetic resonance imaging in about one third of elderly subjects, their clinical significance is not known. In 1984, we studied three retired teachers who had extensive deep white-matter brain lesions on magnetic resonance imaging, yet functioned cognitively at an above-average level. Blinded review of 1981 computed tomographic scans revealed patchy white-matter lucencies for two of the subjects. Repeated magnetic resonance imaging in 1987 showed that the deep white-matter brain lesions were at least as extensive as in the initial study. One subject had developed renal failure, while the other two continued to function at a high level with no evidence of cognitive decline or psychiatric or neurologic impairment. The presence of extensive deep white-matter brain lesions for up to 7 years in two subjects whose cognitive, behavioral, and neurologic functioning is unimpaired suggests that deep white-matter brain lesions do not necessarily indicate a clinically significant central nervous system disease process.

Age Factors↗
PubMed2001

Focal gray matter density changes in schizophrenia.

BACKGROUND: The view that schizophrenia is a brain disease particularly involving decrements in gray matter is supported by findings from many imaging studies. However, it is unknown whether the (progressive) loss of tissue affects the brain globally or whether tissue loss is more prominent in some areas than in others. METHODS: Magnetic resonance whole brain images were acquired from 159 patients with schizophrenia or a schizophreniform disorder and 158 healthy subjects across a 55-year age span. Gray matter density maps were made and analyzed using voxel-based morphometry. RESULTS: Compared with healthy subjects, decreases in gray matter density were found in the left amygdala; left hippocampus; right supramarginal gyrus; thalamus; (orbito) frontal, (superior) temporal, occipitotemporal, precuneate, posterior cingulate, and insular cortices bilaterally in patients with schizophrenia or schizophreniform disorder. Compared with healthy subjects, increases in gray matter density were exclusively found in the right caudate and globus pallidus in patients with schizophrenia or schizophreniform disorder. A group-by-age interaction for density was found in the left amygdala, owing to a negative regression slope of gray matter density on age in the left amygdala in patients compared with healthy subjects. CONCLUSIONS: Gray matter density is decreased in distinct focal areas in the brains of patients with schizophrenia or schizophreniform disorder. The decreased density in the left amygdala is more pronounced in older patients with schizophrenia.

Adolescent↗
PubMed2003

Differences and similarities in insular and temporal pole MRI gray matter volume abnormalities in first-episode schizophrenia and affective psychosis.

CONTEXT: Whether psychoses associated with schizophrenia and affective disorder represent manifestations of different disorders or the same disorder is an important but unresolved question in psychiatry. Results of previous volumetric magnetic resonance imaging investigations indicate that gray matter volume reductions in neocortical regions may be specific to schizophrenia. OBJECTIVE: To simultaneously evaluate multiple olfactocentric paralimbic regions, which play crucial roles in human emotion and motivation, in first-episode patients with schizophrenia and affective psychosis. DESIGN: A cross-sectional study using high-spatial resolution magnetic resonance imaging in patients with schizophrenia and affective psychosis at their first hospitalization. SETTING: Inpatient units at a private psychiatric hospital. PARTICIPANTS: Fifty-three first-episode patients, 27 with schizophrenia and 26 with affective (mainly manic) psychosis, and 29 control subjects. MAIN OUTCOME MEASURES: Using high-spatial resolution magnetic resonance imaging, the gray matter volumes of 2 olfactocentric paralimbic regions of interest, the insular cortex and the temporal pole, were evaluated. RESULTS: A bilateral volume reduction in insular cortex gray matter was specific to first-episode patients with schizophrenia. In contrast, both first-episode psychosis groups showed a volume reduction in left temporal pole gray matter and an absence of normal left-greater-than-right asymmetry. Region of interest correlations showed that only patients with schizophrenia lacked a positive correlation between left temporal pole and left anterior amygdala-hippocampal complex gray matter volumes, whereas both psychosis groups were similar in lacking normal positive correlations between left temporal pole and left anterior superior temporal gyrus gray matter volumes. CONCLUSIONS: These partially different and partially similar patterns of structural abnormalities in olfactocentric paralimbic regions and their associated abnormalities in other temporolimbic regions may be important factors in the differential and common manifestations of the 2 psychoses.

Acute Disease↗
PubMed2006

Smaller neocortical gray matter and larger sulcal cerebrospinal fluid volumes in neuroleptic-naive women with schizotypal personality disorder.

CONTEXT: Structural brain abnormalities, including larger cerebrospinal fluid (CSF) volumes, have been observed in men diagnosed as having schizotypal personality disorder (SPD). OBJECTIVES: To determine whether women with SPD have abnormalities similar to those of men with SPD and to elucidate specific SPD regional volume deficits and symptom correlations. DESIGN: Naturalistic study. SETTING AND PARTICIPANTS: Thirty neuroleptic-naive women with SPD and 29 female control subjects, both recruited from the community. Participants were group matched for age, parental socioeconomic status, handedness, and IQ. INTERVENTIONS: A new segmentation method was applied to magnetic resonance images to automatically parcel the images into CSF, gray matter, and white matter. The neocortex was manually separated from subcortical and other nonneocortical structures. Voxel-based morphometry was applied to determine global and regional volume deficits. MAIN OUTCOME MEASURES: Left and right neocortical gray matter, white matter, and CSF relative volumes as well as clinical symptoms from the Structured Interview for Schizotypy and the Schizotypal Personality Questionnaire-Brief Version. RESULTS: Smaller left (3.84%) and right (3.83%) neocortical gray matter relative volumes associated with larger left (9.66%) and right (9.61%) sulcal CSF relative volumes were found in women with SPD compared with controls. Voxel-based morphometry showed that the neocortical deficits in SPD were especially prominent in the left superior and middle temporal gyri, left inferior parietal region with postcentral gyrus, and right superior frontal and inferior parietal gyri. In the SPD group, larger lateral ventricle volumes correlated with more severe symptoms on the Structured Interview for Schizotypy and the Schizotypal Personality Questionnaire-Brief Version. CONCLUSIONS: The smaller neocortical gray matter volume and larger sulcal CSF volume provide evidence of the brain basis of this personality disorder and emphasize the communality of brain abnormalities in the schizophrenia spectrum.

Adult↗
PubMed2000

White matter changes on MRI during treatment in children with acute lymphoblastic leukemia: correlation with neuropsychological findings.

BACKGROUND: Treatment of childhood acute lymphoblastic leukemia (ALL) may cause structural and functional brain damage. To find out the incidence of white matter changes during therapy, a prospective MRI study was designed, and the findings were correlated with neuropsychological evaluation. PROCEDURE: Thirty-three children with ALL underwent serial cranial MRI before, during, and after therapy. Twenty-eight of these children underwent also neuropsychological assessment at the end of treatment. They all received intravenous and intrathecal methotrexate for central nervous system (CNS) therapy, 15 patients received cranial irradiation in addition. RESULTS: Transient high-intensity white matter changes were observed by MRI in three children 9% (95% CI, 2-24%) who received chemotherapy only. The high-intensity changes were most prominent in the frontal lobes in two of these children. The children with white matter changes were significantly younger than those with normal MRI (2.8 vs. 7.4 years; mean). There was no correlation between neuropsychological tests and white matter changes, except in attention and in tests referring to the frontal areas in general. CONCLUSIONS: White matter changes are occasionally observed during therapy with the current Nordic protocols. Young children may be more susceptible to developing white matter changes after repeated intravenous methotrexate injections. There is no systematic correlation between neuropsychological deficits and MRI findings.

Adolescent↗