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At least 1,333 records · Page 74Linked to original sources
PubMed1991

Fatty acid composition and dynamics of phospholipids from hake (Merluccius hubbsi) spinal cord and brain and sea bass (Acanthustius brasilianus) brain.

This work studies the phospholipid and fatty acid composition in hake brain and spinal cord and in sea bass brain. Fluorescence anisotropy of phospholipid vesicles labeled with 1,6-diphenyl hexatriene was measured to investigate the associated dynamic properties. In all tissues studied, phosphatidylcholine and phosphatidylethanolamine were the major constituents with minor contributions of phosphatidylserine, phosphatidylinositol and sphingomyelin. Fatty acids belong to the n-9 and n-3 series exclusively. Phosphatidylinositol from hake spinal cord and phosphatidylethanolamine and phosphatidylserine from hake brain contain the greatest percentages of eicosa-5,8,11,14,17-pentaenoic (20:5) and docosa-4,7,10,13,16,19-hexaenoic (22:6), respectively. For all fractions studied the total content of saturated fatty acids increases in the order of hake spinal cord, hake brain, sea bass brain together with a decrease in the sum of monounsaturated fatty acids. The comparison between fluorescence anisotropy values and fatty acid composition clearly demonstrates that saturated acids and 20:5 and 22:6 exert a rigidizing effect.

Animals↗
PubMed1990

Brain-type glucose transporter (GLUT-1) is selectively localized to the blood-brain barrier. Studies with quantitative western blotting and in situ hybridization.

The hypothesis that the GLUT-1 glucose transporter isoform is expressed selectively in brain at the capillary endothelium, i.e. the blood-brain barrier (BBB), was tested by using quantitative Western blotting, cytochalasin B binding, and in situ hybridization in bovine brain cortex. Purified human red cell glucose transporter was used as the standard for quantitative Western blots, because the mobility of the human erythrocyte and BBB glucose transporters in electrophoretic gels was identical. The concentration of immunoreactive glucose transporter in bovine BBB plasma membranes was 10.8 +/- 0.9 pmol/mgp (mean +/- S.E., n = 6). This value was not statistically different from the estimate of the maximal binding sites of D-glucose-displaceable [3H]cytochalasin B binding in the BBB membrane preparations, 11.7 +/- 3.5 pmol/mgp. In situ hybridization experiments using 35S-labeled antisense and sense riboprobes corresponding to nucleotides 385-932 of the GLUT-1 cDNA showed prominent hybridization of the antisense probe over brain microvascular endothelium, but no hybridization over neuropil greater than that found with the 35S-labeled sense probe. These studies are consistent with the following conclusion: (a) essentially 100% of the glucose transporter binding sites at the BBB can be accounted for by the GLUT-1 isoform; (b) in situ hybridization studies confirm previous Northern blot analysis and indicate the GLUT-1 gene is expressed selectively in microvascular endothelium in brain with minimal, if any, expression of this gene in neurons or glial cells in vivo.

Animals↗
PubMedDate not supplied

[Cathepsin H activity in the human brain and human brain neoplasms].

The human brain cathepsin H is shown to be a specific cysteine aminopeptidase with the optimum activity at pH 6.0. Human brain tumours of neuroectodermal (astrocytomas and glioblastomas) and epithelial (meningiomas) origin were used to study the cathepsin H activity in the malignant brain tissue. A significant increase in the aminopeptidase cathepsin H activity was found in malignant human brain tumours as compared to benign tumours and normal brain tissues.

Brain↗
PubMed1988

Neuronal degeneration in the brain of the brindled mouse. Histochemical demonstration of decreased cytochrome oxidase activity in the cerebellum and brain stem.

In order to investigate the levels of cytochrome oxidase activity in neuronal mitochondria in the brain of the brindled mouse hemizygote (BM), the cerebella and brain stems from 12 pairs of brindled and normal littermates aged 13-16 days were examined. The diaminobenzidine method for light- and electronmicroscopic histochemistry was adopted. Light microscopy revealed that mitochondria in the normal cerebellum showed an intensely positive reaction to diaminobenzidine, whereas those in the BM cerebellum showed a very weak reaction indicating an evident reduction of cytochrome oxidase activity. Electron microscopy disclosed a diaminobenzidine-OsO4 product densely appearing on the inner membranes of most mitochondria in Purkinje cells in the normal cerebellum. However, it was very faint or absent in those in the BM cerebellum. The same was true in Golgi II cells, granule cells, glomeruli and brain stem nuclei, but the degree of reduction was not uniform among these structures. In conclusion, there is not only a generalized reduction of cytochrome oxidase activity but also a topographical predilection of areas showing a reduction of the enzyme in the BM cerebellum and brain stem. These facts may explain the pathogenesis of neuronal degeneration in the brain of the BM.

Animals↗
PubMed1988

[The relative importance of the brain stem acoustic evoked potential (BAEP) in patients with brain stem tumors].

The brain stem acoustic evoked potential is a non-invasive procedure at the disposal of neurological diagnostics that permits to obtain information about the functional condition of the brain stem. As regards the question of the topodiagnostic possibilities of this examination method in patients with brain stem tumours the BAEP parameters were compared with the clinical symptoms existing at the time of the examination as well as with computer tomographic findings. There is a good agreement of the severity of the clinical symptoms and the distinction of the BAEP changes. In case of unilateral BAEP changes or BAEP changes with a pronounced accentuation on one side indications with respect to the lateral localisation of the brain stem tumour in connection with the clinical findings can be derived. An exact topodiagnosis of brain stem tumours is exclusively possible by the correlation of clinical symptoms, results of picture-yielding examination methods and BAEP examination.

Adolescent↗
PubMed1988

[Non-clostridial gas-producing brain abscess in a brain death patient--report of a case].

A 46 year old female was admitted to our emergency room because of cardiopulmonary arrest by hanging. After ten minutes cardiopulmonary resuscitation, she was resuscitated but her consciousness did'nt recover. CT-scans on the day of admission showed no abnormalities but on the second hospital day it showed symmetrical low density areas within the basal ganglia, the thalamus, the hippocampus, and the occipital lobe. There were marked enhanced effect in cerebral sulci due to cytotoxic edema of hypoxic encephalopathy. She was comatose for a week, her pupils were dilated, light reflex and other brain stem reflex were absent. CT-scans on the sixth hospital day showed marked brain swelling with disappearance of the ventricular systems (so called brain tamponade). Brain death was confirmed on the basis of Japanese Criteria on the seventh and tenth day of admission. She had been suffering from pneumonia and urinary tract infection with an elevation of temperature since the fourth hospital day. We detected Enterobacter Cloacae (E. Cloacae), Klebsiella Oxytoca from the cultures of sputum and urine. On the tenth hospital day her temperature was running up to 39.4 degrees C and blood count revealed a peripheral blood leucocytosis of 40,300/mm3 with a shift to the left. E. Cloacae was also detected from the cultures of blood. Skull roentgenogram showed multiple gas collections in the ventricular systems. CT-scans on the fourteenth hospital day showed multiple gas-containing brain abscess. The etiology of this infection was considered due to septicemia of E. Cloacae. She died from acute renal failure on the fifteenth hospital day. Consent for autopsy was not accepted.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Abscess↗
PubMed1987

[Criteria of brain death: 3d generation. Interpretation of criteria established by the Federal Chamber of Physicians in determining brain death].

The criteria of brain death published by the Federal Chamber of Physicians in 1982 in their second generation have stood the test of time and remain valid. The most important amendments in issuing a third generation are the following: In primary cerebral lesions supratentorial lesions have to be distinguished from infratentorial processes. In primarily the infratentorial processes EEG activities of the cortex max outlast apneic brain stem areflexia. Therefore in infratentorial processes controls of the EEG are indispensable. The extinction of evoked potentials, certain conditions being observed, may prove the loss of brain stem function and therefore may allow to shorten observation time, and may offer an alternative to isoelectricity in the EEG or cerebral perfusion stop as a diagnostic procedure. Additional tests for brain death are commented on. Special considerations are necessary in brain death in children.

Brain Damage, Chronic↗
PubMed1986

Heterogeneity and structure of brain tubulins from cold-adapted Antarctic fishes. Comparison to brain tubulins from a temperate fish and a mammal.

Tubulins purified from brain tissue of Antarctic fishes assemble in vitro to form microtubules at the low temperatures experienced by these extreme psychrophiles (Williams, R. C., Jr., Correia, J. J., and DeVries, A. L. (1985) Biochemistry 24, 2790-2798). We have initiated studies to determine the structural requirements for assembly of Antarctic fish tubulins at low temperatures. As a first step we have compared the heterogeneity, structures, amino acid compositions, and net charge of brain tubulins purified from three Antarctic fishes (Notothenia gibberifrons, Notothenia coriiceps neglecta, and Chaenocephalus aceratus), from the temperate channel catfish (Ictalurus punctatus), and from a mammal (the cow). Each preparation contained the alpha- and beta-tubulins and was free of microtubule-associated proteins. When examined by isoelectric focusing and by two-dimensional electrophoresis, brain tubulins from the Antarctic fishes were found to be highly heterogeneous; each was resolved into approximately 20 isoelectric variants. The distributions of the isotubulins from the cold-adapted fishes were similar but differed significantly from those of tubulins from catfish and cow. The average isoelectric points of the alpha- and beta-tubulins from the Antarctic fishes were more basic than the isoelectric points of the corresponding tubulins from bovine brain. Peptide mapping confirmed that tubulins from the Antarctic fishes and the mammal differed in structure. The amino acid compositions of fish and mammalian tubulins were similar, but Antarctic fish tubulins apparently contained fewer Glx residues than did catfish or bovine tubulins. Finally, native tubulins from an Antarctic fish and the cow differed slightly in net negative charge. Thus, brain tubulins from the cold-adapted fishes differ structurally from the tubulins of a temperate fish and of a mammal.

Acclimatization↗
PubMed1985

On the blood-brain barrier to peptides: accumulation of labelled vasopressin, DesGlyNH2-vasopressin and oxytocin by brain regions.

After intracarotid injection of 125I-arginine vasopressin (AVP), 125I- or 3H-lysine vasopressin (LVP), 3H-DesGlyNH2-arginine vasopressin (DGAVP), and 125I- or 3H-oxytocin (OXT), the accumulation of radioactivity was determined in 13 to 18 brain regions and anterior pituitary in rats. Calculated extraction by tight capillary regions amounts to about 1-2% independently of the peptide doses injected (4 X 10(-4) to 5 X 10(-9) mol-1). This indicates a low but measurable extraction of labelled peptides which furthermore is nonsaturable. Among brain regions with tight capillaries, the extraction does not vary obviously. Blood-brain barrier (BBB)-free regions extract up to 30 fold more peptide than BBB-protected regions and the extraction varies considerably between individual regions. Within BBB-free regions, the peptides passed the leaky capillary endothelium, but there is no evidence for a penetration to deeper layers of the brain. It is concluded that endogenous blood-borne peptides cannot pass brain barriers in physiologically significant amounts. This does not exclude a possibility that passive transport of minute but effective amounts might occur if high pharmacological amounts of peptides are injected peripherally. But, as shown, none of the peptides studied possesses properties that favour its passage across the BBB.

Animals↗
PubMed1985

[Effect of brain antibodies on the lipid peroxidation process in the brain].

The authors studies the effects of blood serum and IgG fraction from dogs immunized with brain and blood sera from patients with multiple sclerosis and schizophrenia on lipid peroxidation in rat brain homogenates. Measured the content of diene conjugates (DC) and malonic dialdehyde (MDA) in the rat brain after administering the IgG fraction. It was established that antioxidant activity of blood sera and IgG fraction from control animals and donors was significantly higher as compared to experimental. Administration of the IgG fraction brought about an increase in the content of DC and MDA in the brain of experimental animals. It is concluded that complement-dependent brain antibodies present in the blood serum of patients with schizophrenia and multiple sclerosis potentiate lipid peroxidation in the cerebral tissue and that the unsophisticated and informative method for antibody determination may be used in clinical practice.

Animals↗
PubMed1985

[3H]Methotrexate loss from the rat brain following enhanced uptake by osmotic opening of the blood-brain barrier.

Right brain regions of anesthetized rats were loaded with [3,5,7-3H]methotrexate ([3H]MTX) or with [14C]sucrose by infusing the tracers into the right carotid artery, after the blood-brain barrier had been opened by right carotid infusion of a hypertonic arabinose solution. During the 6 hr following the procedure, the [3H]MTX concentration in 7 right-sided brain regions, when normalized to the plasma concentration integral during tracer infusion, fell, with an average half-time of 4.8 hr as compared to less than 20 min for the initial rate of loss [14C]sucrose. Right-left brain concentration differences 3 hr after treatment were statistically significant (p less than 0.05) for [3H]MTX but not for [14C]sucrose. The results indicate that intracerebral [3H]MTX is lost more slowly than is intracerebral [14C]sucrose, possibly because [3H]MTX enters brain cells, whereas [14C]sucrose remains largely extracellular.

Animals↗
PubMed1975

[Sensitization against the antigens of the brain after experimental vaccinia infection. I. Evidence for cell-mediated immune response to brain-antigens (author's transl)].

Vaccinia virus infection was performed by scarification of the shaved skin (5 times 5 cm2) on the back of Pirbright guinea pigs. The macrophage migration inhibition test was performed with peritonealexudate cells 7, 11, 14 and 21 days after infection. Macrophage migration inhibition occurred after exposure of the cells to whole brain tissue antigen on the 7th, 11th, 14th day after infection (s. table 1). Lymphocyte transformation responses were examined by 14C-2-Thymidin uptake using blood cultures and basic encephalitogenic protein and whole brain tissue extract as antigens. A positive transformation response could be demonstrated from one to 8 weeks after infection (s. table 2). The specificity of the transformation response to brain antigen was established using control cultures stimulated with PHA or PPD. In no case stimulation occured with PPD. Stimulation with PHA was not altered. On the other hand the spontaneous lymphocyte transformation was enhanced at one week after infection and lymphocyte cultures exposed to heat inactivated vaccinia virus showed transformation from the 3th week after infection until the end of the observation period (i.e. 8 weeks) (s. table 2). The reason why cell mediated hypersensitivity to brain antigen is induced following vaccinia infection remains unknown. The most probable among several possible mechanisms seem a) the induction of virus-specific antigens on the surface of infected cells or b) the release of brain specific antigen through virus infection.

Administration, Topical↗
PubMedDate not supplied

[Short-latency brain-stem auditory evoked potentials in patients with a brain concussion].

The short-latent acoustic stem potentials were examined in 72 males aged 9 to 61 years (mean 32.3 +/- 10.2 years) with concussion of the brain in different early posttraumatic periods (0.5-15 days). The clinical picture of the victims was characterized by systemic cerebral and mild transient symptoms of involvement of stem regions of the brain. Two thirds of the patients were found to have decreased rates of conduction of electric pulses along the acoustic pathway of the brain stem. Moreover, a fourth of the victims had a retarded perception of acoustic stimuli, which implies that concussion of the brain led to the decreased function of the auditory nerve and all relay nuclei of the acoustic system of the brain. The normal pattern of short-latent acoustic stem evoked potentials was seen in 8.3%, their mild and moderate abnormal changes were observed in 40.3 and 51.4% of the patients. Prolongation of a latent period and interpeak intervals, the deformation and lack of waves were considered to be criteria for abnormal changes in short-latent acoustic stem evoked potentials.

Acoustic Stimulation↗
PubMed1995

[A study on thallium-201 SPECT in brain metastases of lung cancer: with special reference to tumor size and tumor to normal brain thallium uptake ratio].

Thallium-201 brain SPECT was performed on 20 patients with brain metastases of lung cancer using a three-head rotating gamma camera and the effect of tumor size on tumor detectability and tumor to normal brain thallium uptake ratio (T/N ratio) was studied. Among 71 metastatic lesions, only 9 (22.5%) of 40 lesions of 13 mm diameter or below and 31 (100%) of 31 lesions of 14 mm diameter or above could be detected in this study. There was a significant correlation between T/N ratio and tumor size (r = 0.75, p < 0.001). The greater the metastatic lesion, the higher the T/N ratio. Even among the tumors in a single patient with multiple brain metastases, there was a significant linear correlation between tumor size and T/N ratio (r = 0.96, p < 0.01). In this patient, T/N ratio varied by the tumor size and these differences in T/N ratios were thought to be based on the partial volume effect. However, T/N.d which was a parameter corrected by tumor diameter (d) showed a constant value regardless of tumor size. The present results showed that T/N ratio, which was usually believed to quantitate the malignancy grade of brain tumor, was affected by tumor size and that more accurate parameter could be obtained by the correction of T/N ratio by tumor size.

Adenocarcinoma↗
PubMed1994

Stereotactic PET atlas of the human brain: aid for visual interpretation of functional brain images.

UNLABELLED: In the routine analysis of functional brain images obtained by PET, subjective visual interpretation is often used for anatomic localization. To enhance the accuracy and consistency of the anatomic interpretation, a PET stereotactic atlas and localization approach was designed for functional brain images. METHODS: The PET atlas was constructed from a high-resolution [18F]fluorodeoxyglucose (FDG) image set of a normal volunteer (a 41-yr-old woman). The image set was reoriented stereotactically, according to the intercommissural (anterior and posterior commissures) line and transformed to the standard stereotactic atlas coordinates. Cerebral structures were annotated on the transaxial planes by using a proportional grid system and surface-rendered images. The stereotactic localization technique was applied to image sets from patients with Alzheimer's disease, and areas of functional alteration were localized visually by referring to the PET atlas. RESULTS: Major brain structures were identified on both transaxial planes and surface-rendered images. In the stereotactic system, anatomic correspondence between the PET atlas and stereotactically reoriented individual image sets of patients with Alzheimer's disease facilitated both indirect and direct localization of the cerebral structures. CONCLUSION: Because rapid stereotactic alignment methods for PET images are now available for routine use, the PET atlas will serve as an aid for visual interpretation of functional brain images in the stereotactic system. Widespread application of stereotactic localization may be used in functional brain images, not only in the research setting, but also in routine clinical situations.

Adult↗
PubMed1993

Migratory pattern of fetal rat brain cells and human glioma cells in the adult rat brain.

The migratory behavior of two human glioma cell lines (D-54MG and GaMG) and fetal rat brain cells grafted into the adult rat brain was studied. To trace the implanted cells, they were stained with the carbocyanine vital dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate before injecting them into the white matter above the corpus callosum. The animals were sacrificed 2 h and 7 and 21 days after injection, and the brains were removed and cryosectioned. Fluorescence microscopy showed that both the 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate-stained fetal and tumor cells had the same migratory pattern. Implanted cells were found along myelinated fibers in the corpus callosum and in the perivascular space. After immunostaining for several extracellular matrix (ECM) components (laminin, fibronectin, collagen type IV, and chondroitin sulfate), laminin deposits were observed in the border zone between the host tissue and implanted tumor cells as well as fetal cells. By using two different types of antibodies against fibronectin, it is shown that the fibronectin expression observed in the tumor matrix may be host derived. This was further supported by the fact that tumor spheroids obtained from the two glioma cell lines were negative when immunostained for these ECM components. Several of the ECM components may be host derived. This can be caused by neovascularization and repair synthesis or by a local production of guiding substrates which are important for tumor cell locomotion. The present data suggest that the migratory patterns of fetal and glioma cells are indistinguishable when transplanted into the adult rat brain. Thus, glioma cells may be routed by the same ECM components that play a major role during brain development.

Animals↗
PubMed1995

[Effect of DL-butylphthalide (NBP) on mouse brain energy metabolism in complete brain ischemia induced by decapitation].

The effects of NBP on gasping and brain energy metabolism after complete brain ischemia in mice subjected to decapitation were investigated. The levels of ATP, phosphocreatine (PCr) and lactate were determined by the method of Lowry. The data indicated that NBP at 112.5 or 250 mg.kg-1 sc can significantly prolong the duration of gasping and at the dose of 150 or 200 mg.kg-1 sc reduce the level of lactate and increase the levels of ATP and PCr after complete brain ischemia. The results suggest that NBP may have brain protective action and improve ischemic brain energy metabolism.

Adenosine Triphosphate↗
PubMed1997

Efficacy of postacute brain injury rehabilitation for patients with primary malignant brain tumors.

BACKGROUND: Patients with primary malignant brain tumors (PMBT) often have neurobehavioral deficits due to the tumor, subsequent surgery, and therapies that interfere with their ability to live independently or work. Previous studies have shown that such patients generally have a progressive decline in functioning from diagnosis to death. Consequently, PMBT patients have not been considered good candidates for rehabilitation services. The current study is a preliminary, retrospective investigation of the effectiveness of postacute brain injury rehabilitation methods, originally developed for traumatic brain injury survivors, in a sample of patients with PMBT. METHODS: The subjects were 13 patients with a history of surgical resection of PMBT and subsequent radiation and chemotherapy. There were 8 males and 5 females with a mean age of 34.3 +/- 10.0 years and a mean educational level of 15.1 +/- 1.7 years. Mean time from tumor diagnosis to the commencement of rehabilitation was 75.4 +/- 87.9 months. All patients had cognitive deficits documented with neuropsychologic tests. Patients received an average of 2.6 +/- 1.9 months of postacute brain injury rehabilitation. RESULTS: Six patients had increased independence during the time from the start of rehabilitation to discharge, six were unchanged, and one patient had decreased independence. Eight patients had increased productivity during the same time period, four were unchanged, and one had decreased productivity. Treatment gains were maintained at follow-up 8.0 +/- 7.6 months after discharge. CONCLUSIONS: The results of the current study offer preliminary support for the effectiveness of postacute brain injury rehabilitation in the management of PMBT patients. Although additional investigation is needed, such treatment appears to be an attractive, relatively low cost option for these patients.

Adult↗