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Biomedical subjects

E Tani

Publications and source records attributed to E Tani.

At least 73 records · Page 4Linked to original sources
PubMed1995

DNA image cytometry and the expression of proliferative markers (proliferating cell nuclear antigen and Ki67) in non-Hodgkin's lymphomas.

We have analyzed DNA content and proliferative activity in morphologically defined cell subpopulations of 74 non-Hodgkin's lymphomas (NHL) and 29 reactive lymph nodes using DNA image cytometry and antibodies to proliferative markers (proliferating cell nuclear antigen (PCNA) and Ki67). Thirteen (18.6%) of 70 NHL cases were aneuploid. The follicular center cell-derived lymphomas with DNA aneuploidy had DNA indices (DI) predominantly in the tetraploid region, whereas aneuploid high-grade (HG) NHL presented DNA histograms with multiple aneuploid stemlines. In aneuploid centrocytic-centroblastic (CB/CC) NHLs, DNA aneuploidy was found exclusively in centroblasts, whereas centrocytes in these cases were diploid. Percentages of cells in S and G2/M phase in chronic lymphocytic leukemia (CLL), immunocytoma (IC), centrocytic NHL (CC), and centrocytes from CB/CC were low (< 5%), whereas the respective values for centroblasts in CB/CC and in malignant cells of HG NHL were similar to those of large lymphoid cells in the reactive lymph nodes (mean, 39.5%, 36.6%, and 53.5%, respectively). The mean percentage of PCNA positive cells in CLL, IC, and CC was 4.9%. In the follicles of CB/CC NHLs there was, on average, 56.9% of PCNA positive centroblasts and 8.1% of PCNA positive centrocytes. In HG NHL, the mean percentage of PCNA positive lymphoma cells was 27.9%. A positive correlation was found between percentages of cells in S and G2/M phase and cells positive for PCNA (P < 0.001). There was also a significant correlation between percentages of Ki67 (mean, 19.2%) and PCNA positive cells (mean, 17.7%) (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

[A case of suprasellar arachnoid cyst followed up for a long time].

We followed a case of suprasellar arachnoid cyst for 12 years. The patient was a sixteen-year-old girl without particular problems in her general condition. She showed optic atrophy in both eyes and optic nerve hypoplasia with an inferotemporal quandranopsia in the left eye. A suprasellar arachnoid cyst communicating with the tubarachnoid space was found to extend into the sella turcica as an empty sella. A cyst wall was resected and a cyst-peritoneal shunt performed. After 12 years from the operation, sensitivity was slightly depressed in the visual field where it had already been disturbed. Although there are few reports in the literature on involvement of the optic nerves and chiasma by suprasellar arachnoid cysts, papilledema and optic atrophy are often found in children, and infero-temporal quandranopsia or homonymous hemianopsia have been reported. Visual field defects were most likely caused by compression of the optic nerve by cyst or prolonged papilledema. We also suspect that some kind of disturbance to the optic nerve occurred during extension of the arachnoid cyst as an empty sella, or during formation of arachnoid cyst in the fetus stage.

Adolescent↗
PubMed1994

The immunohistochemical distribution of protein kinase C isozymes is altered in the canine brain and basilar artery after subarachnoid hemorrhage.

The effects of subarachnoid hemorrhage on immunoreactivities of protein kinase C isozymes (alpha, beta, gamma) were studied in canine brain and basilar artery. Mild and severe constriction of the basilar artery was shown 2 days and 7 days after hemorrhage, respectively. In control brain tissues, the isozymes showed distinct distributions and following hemorrhage, reactive astrocytes with protein kinase C alpha staining emerged in the surface of the pons and hippocampus. The control basilar artery showed protein kinase C alpha staining and its staining was decreased on day 7, consistent with the result of immunoblot. Our results demonstrated that subarachnoid hemorrhage induces gliosis with heavy protein kinase C alpha staining and down-regulation of protein kinase C in the artery.

Animals↗
PubMed1994

Spatial resolution of the primary beta-amyloidogenic process induced in postischemic hippocampus.

Proteolytic modifications of amyloid precursor protein (APP) play key roles in the development of Alzheimer's disease. However, each specific in vivo process has not yet been fully resolved in spatial terms because the orthodox approach employing electrophoretic analysis requires homogenization of samples and thus provides limited information on the localization of the process. To acquire such spatial information for the primary process involved in beta-amyloidogenesis, we have designed and developed a novel antibody exclusively specific to APP fragments possessing the exact amino terminus of the major beta-amyloid (A beta) peptide. Use of this antibody revealed that cleavage of APP at the amino terminal position of the A beta sequence is a normal steady-state process in gerbil hippocampus. Furthermore, nonfatal transient (10 min) forebrain ischemia followed by reperfusion enhanced the initial beta-amyloidogenic reaction mainly in pyramidal cells of CA1 sector and of dentate gyrus prior to and along with delayed neuronal degeneration. The APP fragments accumulated in cell bodies and dendrites of the neurons. These results suggest that beta-amyloidogenesis may involve a process that is also activated in postischemic brain and that ischemia-like conditions may contribute to pathogenic A beta accumulation.

Alzheimer Disease↗
PubMed1994

Stimulation of protein-tyrosine phosphorylation in gerbil hippocampus after global forebrain ischemia.

Tyrosine phosphorylation in the gerbil hippocampus after a transient ischemia was analyzed by immunoblotting and immunohistochemistry. In control hippocampus, the phosphotyrosine was detected in many proteins of 165 to 10 kDa and the immunostain showed a distinct distribution. The ischemic insult induced various alterations of the phosphotyrosine immunoreactivities in both ischemia-resistant and -vulnerable neurons which were associated with alterations in the expression of 165 to 19 kDa-immunoreactive bands. These results suggest that tyrosine phosphorylation is involved in the ischemic hippocampus to play a role in the development of early and delayed neuronal deaths in CA4 and CA1 neurons, respectively.

Animals↗
PubMed1994

Cerebrospinal fluid leakage from the nipple after ventriculoperitoneal shunt: case report.

A case of ventriculoperitoneal shunt malfunction is presented, in which cerebrospinal fluid was discharged from the nipple. A pseudocyst was found at the end of peritoneal catheter in the right subphrenic abdominal cavity. In addition, a fibrous tract was formed around the peritoneal catheter and communicated with the lactiferous duct probably injured incidentally during the subcutaneous insertion of catheter. Consequently, cerebrospinal fluid accumulated in the pseudocyst in the abdominal cavity and then flowed backward in the fibrous tract to the lactiferous duct during the respiration to discharge from the nipple.

Abdomen↗
PubMed1994

Effect of tyrphostin on cell growth and tyrosine kinase activity of epidermal growth factor receptor in human gliomas.

The effects of tyrphostin, a selective protein tyrosine kinase inhibitor, on epidermal growth factor (EGF)-stimulated cell growth and EGF-receptor tyrosine kinase activity were studied in four human glioma cell lines. Stimulation by EGF induced variable enhancements of cell growth as well as tyrosine phosphorylation of EGF receptor and intracellular target proteins in all glioma cell lines. The level of immunoreactive EGF receptor detected with antibodies against extra- and intracellular domains was moderate in all four glioma cell lines, but markedly decreased with the latter antibody in two glioma cell lines. This variation was associated with considerable reduction of the EGF-stimulated tyrosine autophosphorylation level. Tyrphostin inhibited dose-dependently the EGF-stimulated cell growth and tyrosine autophosphorylation in all glioma cell lines, and the optimum time for the maximum inhibitory effect on tyrosine autophosphorylation was 12 to 18 hours after treatment with tyrphostin. The antiproliferative activity of tyrphostin nearly correlated quantitatively with its potency as an inhibitor of the EGF-stimulated EGF receptor tyrosine kinase activity. Tyrphostin had no significant effect on the immunoreactive EGF receptor levels, on the affinity constants and numbers of EGF receptor, or on the down-regulation and specific internalization of EGF receptor in any glioma cell line, suggesting that the effects of tyrphostin are not likely to be the results of reduction in EGF receptor and EGF binding capacity. In addition, the serum-stimulated cell growth was also inhibited dose-dependently by higher concentrations of tyrphostin in all glioma cell lines. It might be suggested, therefore, that tyrphostin inhibits EGF-stimulated cell growth by a specific suppression of EGF receptor tyrosine kinase activity, and at higher concentrations there appears to be some degree of either nonspecific inhibition or inhibition of serum-stimulated protein tyrosine kinase activity to induce the cell growth inhibition of gliomas.

Catechols↗
PubMed1994

Immunohistochemical differential diagnosis of benign cysts in the central nervous system.

This report concerns the immunohistochemical characterization of 6 cases of thin-walled cysts in the central nervous system (enterogenous cyst, paraphyseal neuroepithelial cyst, Rathke's cleft cyst and arachnoid cyst). Antibodies to glial fibrillary acidic protein (GFAP), S-100 protein, epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), keratin (KER) and vimentin (VIM) were used. The enterogenous cyst was positive for KER, EMA and CEA. The neuroepithelial cyst of paraphyseal origin was positive for KER and S-100. The three Rathke's cleft cysts were positive for KER and EMA, but negative for S-100 and CEA, and the arachnoid cyst was positive for EMA and VIM. A unified concept and classification of the types of cysts studied based on immunohistochemical assays are proposed.

Adolescent↗
PubMed1994

Preoperative embolization of meningiomas: its efficacy and histopathological findings.

This report deals with the operative and histopathological findings in 14 meningiomas of 13 patients who were subjected to preoperative embolization. This procedure facilitated the removal of 11 of the 14 tumors and minimized blood loss. In the majority of cases the following histopathological findings were documented: 1) Presence of emboli and thrombi within the tumor and/or dural vessels; 2) associated vascular thrombosis; 3) ischemic changes of the tumor cells; 4) pathologic evidence of infarction with or without inflammatory response, and 5) diffuse or nodular necrosis and surviving tumor cell clusters with an island-like appearance. In two tumors in which the histological diagnosis of typical meningioma was difficult, large necrotic areas comprising over two-thirds of the whole specimens were seen with the naked eye.

Adolescent↗
PubMed1994

Synthesis and effect on free radical processes on some substituted morpholine derivatives with potential biologic activity.

Since a number of 2-hydroxy(alkoxy)-2-phenyl-4(5,6)-(tri)alkyl-morpholines presented antioxidant and interesting biologic activity which may implicate free radical processes, some 2-hydroxy(alkoxy)-2-biphenyl-4-methyl-morpholine derivatives were prepared in an attempt to synthesize more potent antioxidants with interesting biologic action. The 2-hydroxy-2-biphenyl-4-methyl-morpholine was prepared by reacting the N-methyl-ethanolamine with the p-phenyl-phenacylbromide, the 2-hydroxy-derivative formed after spontaneous cyclisation gave the 2-alkoxy-2-biphenyl-4-methyl morpholines by an acid catalyzed ketal formation. The lipophilicity of the synthesized compounds was determined by the reversed phase TLC technique as RM values. The synthesized 2-biphenyl substituted morpholines were evaluated for their antioxidant activity on hepatic microsomal lipid peroxidation and on hydroxyl radical mediated oxidation of dimethylsulfoxide. The synthesized compounds were found to possess potent antioxidant activity. A possible mechanism was proposed for the antioxidant properties while lipophilicity was found not to be an important determinant of this property.

Animals↗
PubMed1993

Spatial resolution of fodrin proteolysis in postischemic brain.

One of the major obstacles in investigating in vivo proteolytic phenomena has been the inaccessibility to spatial information as to where in the tissue the reaction proceeds because the orthodox method employing electrophoretic analysis requires homogenization of samples and thus results in loss of such spatial information. To overcome this technical drawback, we have developed methodology to produce antibodies that specifically distinguish a proteolyzed form of a given protein from its intact form. Here we describe our immunohistochemical observation of calpain-catalyzed fodrin proteolysis in postischemic gerbil hippocampus, using an antibody exclusively specific to the proteolyzed 150-kDa form of fodrin alpha subunit. Our data establish a novel discovery that transient (10 min) global forebrain ischemia followed by reperfusion induces at least two distinct phases of fodrin proteolysis in hippocampus: an early phase in molecular layer and in stratum oriens of CA3 and CA1 sectors within 15 min and a late drastic and persistent phase in the entire CA1 after 4-24 h. The former may be one of the early events initiating the complex cascade leading to the delayed neuronal death, while the latter should be considered as a more direct cause for the actual degeneration in CA1.

Animals↗
PubMed1993

Expressions of matrilysin and stromelysin in human glioma cells.

Production of matrilysin and stromelysin by five human glioma cell lines was investigated by Northern blot and immunoblot analyses. Four cell lines constitutively produced matrilysin. Its production was stimulated by phorbol-12-myristate-13-acetate (PMA) in two cell lines and by transforming growth factor-beta 1 (TGF-beta 1) in two other cell lines. Stromelysin transcript was constitutively expressed in only two cell lines, but enhanced or induced by PMA in four cell lines. These results suggest that these enzymes, especially matrilysin, may be involved in the invasive growth of neoplastic glial cells.

Blotting, Northern↗
PubMed1993

Stabilization of c-myc protein in human glioma cells.

The regulation of c-myc protein, product of c-myc/genes, was studied in four glioma cell lines by Northern blot, pulse-chase dot blot, immunoblot and immunoprecipitation analyses. Northern blot analysis revealed no overexpression of c-myc transcript, and pulse-chase dot blot analysis showed normal turnover rate of c-myc transcript, suggestive of no evidence of aberrant regulation of c-myc at post-transcriptional level. The synthesis levels of c-myc protein were shown by immunoprecipitation and closely associated with the c-myc transcript levels demonstrated by Northern blot, suggestive of no evidence of aberrant translational control of c-myc, whereas they were dissociated from the accumulation levels of c-myc protein shown by immunoblot, suggestive of an evidence of aberrant regulation of c-myc at post-translational level. The mean (+/- standard deviation) half-lives of c-myc protein in four glioma cell lines were calculated from the pulse-chase immunoprecipitation analysis, and being 98 +/- 8 to 143 +/- 11 min, were about four- to sixfold longer than normal. In surgical specimens, the immunostain of c-myc protein was not found in normal astrocytes but localized heterogenously in nuclei of reactive astrocytes and glioma cells, and increased in stained cell number in proportion to malignancy. Although this study was limited to four glioma cell lines, it suggests that the c-myc protein in glioma cells may be accumulated due to its prolonged half-life contributing to an uncontrolled proliferation.

Astrocytes↗
PubMed1993

Estrogen and progesterone receptor content in breast epithelial cells from healthy women during the menstrual cycle.

OBJECTIVE: Our objective was to analyze the presence of estrogen and progesterone receptors in breast epithelial cells from healthy women during the follicular and luteal phase of the menstrual cycle. STUDY DESIGN: We analyzed estrogen receptor and progesterone receptor variations in breast epithelial cells procured through fine-needle aspiration biopsy from 42 healthy volunteers during the menstrual cycle using immunocytochemical receptor analysis. Differences were assessed by chi 2 test and the Wilcoxon rank sum tests. RESULTS: Estrogen receptor was detected more often in women aspirated in the follicular (68%) than in the luteal (32%) phase (p < 0.001); progesterone receptor was detected in around 80% in both phases. In ovulating women who were aspirated twice during the same menstrual cycle the proportion of estrogen receptor-positive cells was reduced from 20% to 4% (p < 0.02); the progesterone receptor values were 17% and 24%. CONCLUSION: Our data indicate an important difference in progesterone receptor variation in the breast as compared with the endometrium.

Adult↗
PubMed1993

Pulse methylprednisolone therapy in the treatment of Wegener's granulomatosis.

Five patients with Wegener's granulomatosis were treated with high-dose intravenous methylprednisolone (MTP) pulse therapy. Three out of five patients received MTP pulse therapy as the initial treatment and remission was achieved. Renal biopsy after the treatment confirmed the improvement of kidney involvement in 2 cases. Although the other two patients received MTP pulse therapy when a relapse occurred, the therapy could not suppress the progression of the disease. These observations suggest that MTP pulse therapy when given early may make it possible to suppress the progression of kidney involvement and improve the prognosis of the disease. Furthermore, it may also decrease the total doses of oral steroids and cyclophosphamide because of a strong anti-inflammatory and immunosuppressive action and consequently diminish the side effects. In conclusion MTP pulse therapy as the initial treatment may be beneficial in treating patients with Wegener's granulomatosis.

Adult↗
PubMed1993

Immunoblotting of contractile and cytoskeletal proteins of canine basilar artery in vasospasm.

Vasospasm was produced in the canine basilar arteries by a two-hemorrhage method, and voltage- and receptor-dependent contractions of the normal canine basilar arteries were induced by local applications of potassium chloride (KCI) and serotonin, respectively, after transclival exposure. Actin, myosin, desmin, filamin, talin, vinculin, and alpha-actinin in the basilar artery were studied by immunoblotting. The immunoblots showed a decrease or loss in immunoreactivity of some native proteins and generation of protein fragments, smaller in size than native proteins, in spastic, KCI, and serotonin groups, indicating a proteolytic degradation. In the spastic group on Day 2, actin, desmin, and filamin were usually degraded slightly; myosin moderately; and talin and alpha-actinin substantially. Vinculin and metavinculin remained intact. In the spastic group on Day 7, actin and desmin were usually decomposed slightly; myosin, filamin, and vinculin substantially; and talin, metavinculin, and alpha-actinin markedly. In the KCI and serotonin groups, slight degradation was usually observed in filamin, often in alpha-actinin, and occasionally in actin, whereas desmin, vinculin, and metavinculin were not degraded. In addition, myosin was usually degraded moderately in the KCI group and slightly in the serotonin group, and talin was generally decomposed slightly in the KCI group and moderately in the serotonin group. The degraded fragments, although variable in number and immunoreactivity, were similar in size in the three groups. We suggest that the intracellular devices responsible for contraction of the basilar arteries are degraded more severely in the spastic group than in the KCI or serotonin group, probably by similar proteolytic mechanism and progressively with the passage of time after subarachnoid hemorrhage in vasospasm.

Animals↗
PubMed1993

Calpain-calpastatin system of canine basilar artery in vasospasm.

Vasospasm was produced in the canine basilar artery by a two-hemorrhage method, while contraction was induced in the normal canine basilar artery by a local application of KCl or serotonin after transclival exposure. The control animals were injected with saline instead of fresh blood. The activation of mu-calpain, a Ca(++)-dependent neutral protease, in the basilar artery was studied by evaluating the conversion from its inactivated into its activated form on immunoblots. In addition, the activity of calpastatin, an intrinsic inhibitor of calpain, in the basilar artery was determined by assay. The majority of the mu-calpain was inactivated in the control group. In the spastic group, mu-calpain was generally activated markedly in the early stage of vasospasm and moderately thereafter. The contraction induced by KCl or serotonin application was classified into the early phasic and the later tonic stages; mu-calpain was usually activated in the phasic stage and inactivated in the tonic stage. Calpastatin activity was significantly decreased during vasospasm, whereas it was not significantly changed in KCl- or serotonin-induced contraction. The final activity of mu-calpain results from the balance of mu-calpain and calpastatin. This suggests that mu-calpain activity was enhanced continuously in the spastic group and transiently in the KCl or serotonin group, and that the continuous activation of mu-calpain during vasospasm probably induced more proteolytic changes compared to those in the KCl or serotonin group.

Animals↗