Posteroventral pallidotomy in a patient with parkinsonism caused by hypoxic encephalopathy.
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Brain↗
Biomedical subjects
Y Ushio
Publications and source records attributed to Y Ushio.
Stereotactic selective Vo-complex thalamotomy in a patient with dystonic writer's cramp.
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Adolescent↗
Effectiveness of retrograde perfusion of the cerebral vein for attenuating neuronal injury after transient ischemia following reperfusion in the rat brain.
The effect of retrograde perfusion of the cerebral vein (RPCV) with antioxidant LY231617 on neuronal injury after transient ischemia in rat brain was examined. Transient ischemia was caused by left middle cerebral artery (MCA) occlusion and reperfusion. Rats were assigned to three groups: Group A (n = 6), MCA occlusion only; Group B (n = 8), RPCV with saline (flow rate 4.95 ml/hr) into the left inferior cerebral vein; and Group C (n = 6), RPCV with LY231617 (20 mg/kg/hr, flow rate 4.95 ml/hr). RPCV in Groups B and C was performed simultaneously with occlusion. Both occlusion and RPCV were performed for 30 minutes in awake animals. Seven days later, all rats were investigated for rotational behavior elicited by apomorphine (1.0 mg/kg), and then immunohistochemical analysis of brain specimens was carried out using calcineurin as a neuronal marker in the striatum to detect the ischemic damaged area. The number of turns to the left (lesioned side) in both Groups B (42 +/- 12) and C (46 +/- 14) was significantly lower (p < 0.01) than in Group A (222 +/- 45), but there was no significant difference between Groups B and C. The percentage ischemic damaged area in both Groups B (17.9 +/- 6.2%) and C (1.6 +/- 1.0%) was significantly less (p < 0.01) in Group A (51.1 +/- 2.1%). RPCV with and without LY231617 during occlusion was effective for attenuating reperfusion injury.
Animals↗
Cerebellar mutism after posterior fossa surgery--two case reports.
Two adults (aged 71 and 74 years) developed cerebellar mutism after posterior fossa surgery for a mass lesion in the superior cerebellar hemisphere or upper vermis. Histological examination showed one was a hemangioblastoma, the other a metastatic brain tumor. The tumors were totally removed via the occipital transtentorial approach. Both patients developed mutism on the 2nd postoperative day, which persisted for 3-4 weeks and was followed within 2-4 months by cerebellar dysarthria. Thereafter, their condition improved. Transient cerebellar mutism usually occurs in pediatric patients after the removal of a mass lesion in the upper vermis. Cerebellar mutism in adults is rare. The predominance of cerebellar mutism in children may be attributable to the predilection for vermian tumor and their tendency to experience personality and behavioral changes after posterior fossa surgery.
Aged↗
Follow-up evaluation of dissecting aneurysms of the vertebrobasilar circulation by using gadolinium-enhanced magnetic resonance imaging.
The authors assessed the reliability of magnetic resonance (MR) imaging contrast enhancement for the detection and follow-up evaluation of dissecting aneurysms of the vertebrobasilar circulation. Twenty consecutively admitted patients who underwent both gadolinium-enhanced MR imaging and conventional angiography were reviewed. Enhancement of the dissecting aneurysm was seen in all but one of the 20 patients, including 10 (71%) of 14 patients examined in the chronic phases, when the T1-hyperintensity signal that corresponded to the intramural hematoma was unrecognizable. The enhanced area corresponded to the "pearl sign" or aneurysm dilation noted on the comparable angiogram. On follow-up MR studies enhancement had spontaneously disappeared in four patients at a time when comparable vertebral angiograms revealed disappearance of the aneurysm dilation. The enhancement persisted in five of nine patients examined more than 24 weeks after symptom onset; in all five patients the aneurysm dilation remained on comparable angiograms. Dynamic MR studies showed rapid and remarkable enhancements with their peaks during the immediate dynamic phase after injection of the contrast material. The authors conclude that gadolinium-enhanced MR imaging is useful for the detection and follow-up evaluation of dissecting aneurysms of the vertebrobasilar circulation.
Adult↗
Treatment of cancer using pulsed electric field in combination with chemotherapeutic agents or genes.
Electroporation is a standard laboratory technique originally developed for in vitro transfer of molecules into cells. It involves application of electrical pulses ranging from micro- to milliseconds that create transient pores in the cell membrane allowing intracellular access of exogenous molecules. This technique has been successfully applied to regress tumors in animal models by combining electroporation with chemotherapeutic agents--a process known as electrochemotherapy (ECT) which substantially enhance cytotoxicity of some antineoplastic agents. Recently ECT has moved into clinical arena and patients with cutaneous tumors and head and neck cancers have been treated very effectively with ECT. Parallel to ECT, a technique has also been developed which makes it possible to inject plasmid DNA and combine it with in vivo electroporation--electro--genetherapy (EGT)--to deliver in a highly efficient manner both marker and functional genes into target tissue and achieve gene expression. Thus, in vivo electroporation is contributing to the development of a new strategy for cancer treatment with both drugs and genes.
Animals↗
MR of epidermoids with a variety of pulse sequences.
PURPOSE: To assess the usefulness of fluid-attenuated inversion recovery (FLAIR) and constructive interference in steady state (CISS) sequences in depicting epidermoid tumors. METHODS: Six patients with surgically confirmed epidermoid tumors in the subarachnoid space were examined with T1-weighted MR imaging with a spin-echo sequence, and with T2- and proton density-weighted imaging with a fast spin-echo sequence, a FLAIR sequence, and a CISS sequence. In the qualitative analysis, three observers compared the five sequences for visibility of tumors and presence of artifacts. A quantitative analysis was also performed by measuring the contrast-to-noise ratio. RESULTS: On visual assessment, the FLAIR sequence depicted all tumors as hyperintense relative to cerebrospinal fluid. The CISS sequence depicted all tumors as hypointense relative to cerebrospinal fluid and was considered to show tumor extension better than the FLAIR sequence. At quantitative analysis, the mean contrast-to-noise ratios of tumor to cerebrospinal fluid on T1-, T2-, and proton density-weighted images, and on FLAIR and CISS sequences were 2.85, 3.41, 4.42, 16.13, and 20.23, respectively. The contrast-to-noise ratios for the FLAIR and CISS sequences were significantly higher than those for the T1-, T2-, and proton density-weighted sequences. The contrast-to-noise ratio was not significantly different between FLAIR and CISS sequences, although the CISS sequence was slightly superior. CONCLUSION: CISS and FLAIR sequences depicted epidermoid tumors in the subarachnoid spaces better than conventional spin-echo images did. The CISS sequence produced a relatively constant contrast between the tumors and less artifactual interference.
Adolescent↗
Neurocutaneous melanosis with intracranial malignant melanoma in an adult: a case report.
A 65-year-old female with congenital giant, hairy and pigmented nevus developed sudden onset of headache and consciousness disturbance. CT scan revealed a high density mass in the right temporal subcortical region. The high density area suggested hematoma. A right temporal craniotomy was performed. Hemorrhage was observed in a black colored tumor. Histologically, the tumor was malignant melanoma, while the skin tumor was benign intradermal nevi. This patient was diagnosed as neurocutaneous melanosis. Neurocutaneous melanosis belongs to unusual congenital syndrome, and an adult case is very rare. To our knowledge this is the oldest patient to be reported with this disease.
Aged↗
Involvement of N-methyl-D-aspartate receptor in the delayed transneuronal regression of substantia nigra neurons in rats.
The substantia nigra pars reticulata (SNr) receives both inhibitory GABAergic and excitatory glutamatergic afferents from diverse origins. Ischemic injury to the striatum and/or the globus pallidus causes delayed transneuronal death of the SNr neurons, in the course of which neuronal disinhibition induced by loss of GABAergic inputs is supposed to trigger a lethal hypermetabolic process. In the in vivo experiment presented herein, we clarified the role of glutamatergic action via the N-methyl-D-aspartate receptor in this cell death process. Continuous intraventricular infusion (0.5 microliter/h) of the N-methyl-D-aspartate receptor antagonist MK-801 (1000 micrograms/ml), or of saline (control group) was initiated 24 h after 2 h of transient middle cerebral artery (MCA) occlusion in rats, by which massive ischemic injury was produced in the striatopallidal regions. The measured rectal temperature was not significantly altered in the MK-801-infused and in the control rats throughout the time period examined. The rats were killed at 15 days after MCA occlusion. The volume of the focal ischemic infarction of the MK-801-infused group did not significantly differ from that of controls. Also, MK-801-infusion did not significantly ameliorate the nigral atrophy subsequent to MCA occlusion. In association with a marked depletion of GABAergic afferent fibers, neuronal cell number in the ipsilateral SNr was significantly decreased in the control group. In contrast, the neuronal cell loss in the nucleus was completely prevented in the MK-801-infusion group. The data suggested that withdrawal of GABAergic inputs may cause a severe imbalance between excitation and inhibition of the SNr neurons and may eventually result in neurotoxicity mediated by the N-methyl-D-aspartate receptor. Suppression of glutamatergic excitatory effects by suitable drugs may be a reasonable therapy for the transneuronal death of the SNr neurons.
Animals↗
Regulation of CCAAT/enhancer-binding protein family members by stimulation of glutamate receptors in cultured rat cortical astrocytes.
Regulation of mRNA levels, DNA binding activities, and phosphorylation of CCAAT/enhancer-binding protein (C/EBP) family members by stimulation of glutamate receptors were studied in cultured rat cortical astrocytes. Indirect immunofluorescence and immunoblot analyses with specific antibodies to C/EBP family members revealed that both C/EBPbeta and C/EBPdelta but not C/EBPalpha are expressed in the nuclei of astrocytes. After exposure to glutamate, C/EBPbeta mRNA levels increased within 10 min, reached the maximal level at about 1 h, and returned to the basal level within 6 h. In contrast, C/EBPdelta mRNA levels decreased by 6 h and were recovered within 12 h. These changes in mRNA levels were accompanied by an increase and a decrease in proteins for C/EBPbeta and C/EBPdelta, respectively. Elevation of C/EBPbeta mRNA levels by glutamate treatment required an increase in intracellular Ca2+ concentration and depended on activations of protein kinase C and calmodulin-dependent protein kinases. Gel mobility shift analysis using nuclear extracts from the glutamate-treated cells showed increases in C/EBP site binding activities 2 h after the exposure to glutamate. Moreover, glutamate stimulated phosphorylation of C/EBPbeta in 32P-labeled astrocytes in a Ca2+-dependent manner. These results suggest that glutamate regulates functions of C/EBP family members in brain astrocytes through changes in mRNA levels of C/EBPbeta and C/EBPdelta as well as through phosphorylation of C/EBPbeta.
Animals↗
Multiple expression of Ly-6C and accumulation of a Ly-6C pre-mRNA in activated macrophages involved in rejection of an allografted tumor.
We established a monoclonal antibody against a surface antigen of activated macrophages (Møs) involved in the rejection of an allografted mouse tumor, Meth A. Bacteria-elicited Møs also expressed the antigen but resident or inflammatory Møs, or other leukocytes, did not. The antigen was identified as Ly-6C by isolation of cDNA clones encoding it. Two-dimensional immunoblotting revealed that Ly-6C of the Møs exists in multiple forms with a similar size but with different isoelectric points. A Ly-6C pre-mRNA also accumulated abundantly in the Møs. Thus, the multiple expression of Ly-6C and the accumulation of the pre-mRNA are the features of allograft- and bacteria-elicited Møs.
Amino Acid Sequence↗
Intrathecal chemotherapy with 1,3-bis(2-chloroethyl)-1-nitrosourea encapsulated into hybrid liposomes for meningeal gliomatosis: an experimental study.
1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), one of the chloroethyl nitrosoureas, is effective against malignant glioma. To develop its use in intrathecal chemotherapy, we encapsulated BCNU in hybrid liposomes composed of dimyristoylphosphatidylcholine and micellar surfactants (Tween 20) and dissolved it in artificial cerebrospinal fluid (lipo-BCNU). We then studied the toxicity of hybrid liposomes and cellular proliferation inhibition of lipo-BCNU in vitro. We found that 3 mM hybrid liposomes did not affect the viability of human endothelial cells and that lipo-BCNU inhibited the proliferation of human glioma cell lines U-105MG, U-251MG, and U-373MG, and rat glioma cell lines C6 and 9L in a concentration-dependent fashion. Wistar rats that were administered lipo-BCNU intracisternally showed no weight loss, neurological symptoms, or histological changes of the brain and spinal cord. A Wistar rat model of meningeal gliomatosis was established by intracisternal inoculation of 0.1 ml cell suspension containing 1 x 10(6) or 5 x 10(6) viable C6 glioma cells. Two days after inoculation, lipo-BCNU (BCNU, 2.5 mg/kg) was administered intracisternally. When 1 x 10(6) glioma cells were inoculated (experiments 1 and 2), the median survival times were 24.5 and 26 days in the control groups and 32 and 45 days in the lipo-BCNU-treated groups. respectively. When 5 x 10(6) glioma cells were inoculated (experiments 3-6), the median survival times were 17-29.5 days in the control groups and 23-44 days in the treated groups, respectively. Significantly prolonged survival was obtained in three of six experimental groups. After the administration of 1 ml lipo-BCNU (BCNU, 4.67 mM) or 1 ml BCNU solubilized with 5% dextrose/water (BCNU, 4.67 mM) into the cisterna magna of dogs, the cisterna magna cerebrospinal fluid was sampled, and the BCNU concentrations were assayed by high-performance liquid chromatography. The half-life of the lipo-BCNU was longer than that of BCNU solubilized with 5% dextrose/water. These results suggest that the intrathecal administration of lipo-BCNU may be possible for the treatment of meningeal gliomatosis.
Animals↗
Inducing the loss of immunoglobulin lambda light chain production and the rearrangement of a previously excluded allele in human plasma B cell lines with concanavalin A.
We investigated the expression of differential lambda light chains in human B cell lines secreting immunoglobulin (Ig). When these cell lines were cultured with concanavalin A for a long period of time, a subpopulation of some but not all of these cell lines was induced to express new lambda light chains replacing the original lambda chain (light chain shifting). Production of the new lambda chain, which replaces the original lambda chain, results from a VJ rearrangement at a previously excluded allele and a dramatic reduction of the original lambda chain transcript, although no difference was found in the level of heavy chain transcript. Recombination activating genes RAG-1 and RAG-2, which are normally expressed during specific early stages of lymphocyte development, were expressed in not only the light chain shifting-inducible lines but also in the non-inducible cells. Treatment of these Ig secreting cell lines with dibutyryl cAMP, which is known to enhance expression of the RAG genes, could not induce the creation of new lambda light chain-producing cells from the inducible lines, suggesting that the expression of the two RAG genes is not sufficient for inducing new lambda light chain production. Concanavalin A induced a gradual but significant production lost of the original lambda chain in a subpopulation of the light chain shifting-inducible cells but not in the non-inducible cells. Association of new lambda light chain production with loss of original lambda chain raises the possibility that, when the RAG genes are expressed, concanavalin A may act on a novel intracellular mechanism controlling lambda light chain allelic exclusion in these plasma cell lines.
Adenocarcinoma↗
Expression of tissue factor correlates with grade of malignancy in human glioma.
BACKGROUND: Tissue factor (TF), a cell surface receptor of factor VII/VIIa, was initially recognized as an initiator of the extrinsic coagulation pathway. TF has recently been found to be expressed highly in certain types of malignant tumors. In addition, TF belongs to the interferon receptor family and is one of the immediate early genes, suggesting that TF may participate in the regulation of cell growth. However, the correlation between the expression of TF and cell growth is still unclear. METHODS: Expression of TF in 6 glioma cell lines and 44 glioma surgical specimens was studied by Northern blot analysis, Western blot analysis, immunohistochemistry, and in situ hybridization. RESULTS: Northern blot analysis showed that glioma cells expressed minor novel transcripts of 3.3 kb and 1.6 kb, in addition to the transcripts of 2.2 kb and 3.1 kb that were previously reported. Western blot analysis revealed that the level of TF protein did not correlate with that of TF transcripts. Although immunohistochemical analysis of surgical specimens showed that all gliomas were positive for TF, it was interesting that 1 of 10 benign gliomas (10%) was positive for TF (malignancy Grade I-II), 13 of 14 anaplastic astrocytomas (86%) (malignancy grade III) and 19 of 20 glioblastomas (95%) (malignancy grade IV) were moderately or strongly positive for TF. In situ hybridization showed the expression of TF mRNA in glioma cells. CONCLUSIONS: TF is expressed in glioma and the level of expression correlates with the histologic grade of malignancy.
Astrocytoma↗
High-efficiency in vivo gene transfer using intraarterial plasmid DNA injection following in vivo electroporation.
A novel method for high-efficiency and region- controlled in vivo gene transfer was developed by combining in vivo electroporation and intraarterial plasmid DNA injection. A mammalian expression plasmid for the Escherichia coli lacZ gene (driven with a SV40 early promoter) was injected into the internal carotid artery of rats whose brain tumors (from prior inoculation) had been electroporated between two electrodes. The lacZ gene was efficiently transferred and expressed in the tumor cell 3 days after plasmid injection. However, neither any gene transfers nor any elevated lacZ activity was detected in tissues outside the electrodes. The plasmid was not transferred without electroporation. Human monocyte chemoattractant protein-1 cDNA was also transferred by this method, and its long-lasting (3 weeks) expression was confirmed by using the Epstein-Barr virus episomal replicon system. The expressed monocyte chemoattractant protein-1 protein was functional, as evident by the presence of a large number of monocytes in tumor tissue. This method, electrogene therapy, which does not require viral genes or particles, allows genes to be transferred and expressed in desired organs or tissues, and it may lead to the development of a new type of highly effective gene therapy.
Animals↗
Alterations of local cerebral blood flow, phorbol 12,13-dibutyrate binding activity, and histological damage during acute focal ischaemia in rat brain. A pathophysiology of acute focal ischaemia: Part 1.
The alterations of the local cerebral blood flow (LCBF), 3H-phorbol 12,13-dibutyrate (PDBu) binding activity were measured, and histological findings were also examined during the closed time course (0, 1, 3, 5, 7 hour) after middle cerebral artery occlusion (MCAO) in rat brain to assess the complex pathophysiology of acute focal ischaemia. From 1 to 3 hours after the start of MCAO, significant (p < 0.01) hyperreactivity of the second messenger system involving PDBu binding may be present, despite low perfusion of LCBF, and severe damage in the striatum whereas sparing almost completely the cortex on histological examination. At 5 hours, the PDBu binding activity increased slightly but not significantly but is reduced markedly at 7 hours after MCAO compared with the control group. The measurement of PDBu binding activity, additionally to measuring the LCBF and observation of the histological change might be a useful indicator in determining the threshold and duration of ischaemia which cause functionally irreversible cell damage in the brain.
Animals↗
Cytochrome oxidase activity during acute focal ischaemia in rat brain. A pathophysiology of acute focal ischaemia: Part 2.
An enzyme-histochemical technique was used to examine the changes in cytochrome oxidase activity during acute focal ischaemia in the rat. In the somatosensory cortex, the enzyme activity began to increase significantly (p < 0.01) 1 hour after middle cerebral artery occlusion (MCAO) and continued to increase up to 3 hours, during which ischaemic cell damage was not detected. In the striatum, the enzyme activity increased significantly (p < 0.01) 1 hour after MCAO in the absence of morphological evidence of ischaemic cell damage; a peak activity was reached at 2 hours, and began to decline 3 hours after MCAO when moderate ischaemic change was detected. In both cortical and subcortical areas, the enzyme activity tended to decrease from 4 hours after MCAO, and was reduced to a level similar to or below that of the non-ischaemic hemisphere 5 hours after MCAO, when severe ischaemic damage was demonstrated. The relation of this transient increase of cytochrome oxidase activity in the early stage of acute ischaemia and the hypermetabolism of neuronal cells during ischaemic insult was discussed.
Animals↗
Modified antigen-binding of human antibodies with glycosylation variations of the light chains produced in sugar-limited human hybridoma cultures.
We have characterized the effects of serum and N-acetylglucosamine in a glucose-deprived condition on the glycosylation of antibody light chains, as well as the resulting biological properties of those antibodies. We have chosen for our investigation the human hybridoma lines producing monoclonal antibodies reactive to lung adenocarcinoma. Each antibody possess a N-glycosylated carbohydrate chain in the hypervariable region of the light chains. When the cell lines were grown in the absence of glucose, variant light chains with varying molecular masses were found to be secreted. Analysis of these light chains produced in a glucose-deprived condition revealed that the changed molecular-mass of the variant light chains is due to different glycosylation. Addition of N-acetylglucosamine or fetal calf serum to the glucose-free medium led to the creation of other light chains that exhibit increased antigen binding activity.
Acetylglucosamine↗