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Biomedical subjects

T Nagatani

Publications and source records attributed to T Nagatani.

At least 37 records · Page 2Linked to original sources
PubMed1998

Hemifacial spasm associated with Marfan's syndrome: a case report.

The authors describe a case of hemifacial spasm associated with Marfan's syndrome. A 24-year-old-woman suffered from left hemifacial spasm for 6 years. She had undergone surgical treatments for bilateral ectopia lentis and kyphoscoliosis in the second decade of life. She also had unusually long and slim limbs with arachnodactyly. Three-dimensional CT angiography revealed bilateral tortuous and elongated vertebral arteries. Microvascular decompression was performed following a left lateral suboccipital craniotomy. The root exit zone of the left seventh nerve was directly compressed by the proximal segment of the anterior inferior cerebellar artery (AICA) and the left vertebral artery. These arteries were decompressed with pieces of Teflon cotton. The patient's symptoms completely resolved following surgery. We review cerebrovascular disorders in Marfan's syndrome and discuss the pathogenesis and possible mechanisms of vascular compression in these patients.

Adult↗
PubMed1998

T cells expressing killer cell inhibitory receptors do not carry TCR for alloantigens.

The role of T cells carrying the killer cell inhibitory receptor (KIR) is unknown. Here we investigate the allo-response of KIR+ CD3+ cells (KIR+ T cells). KIR+ T cells was found in 4.6-14.7% of the T cells from the PBMC of healthy individuals. Flow cytometry analysis showed that the percentage of KIR+ T cells in T cells from three individuals was decreased after stimulation with allogeneic PBMC. These findings suggest that KIR+ T cells do not respond to alloantigens. Furthermore, the analyses using purified KIR+ T cells also confirmed that KIR+ T cells do not respond to alloantigens.

Antibodies, Monoclonal↗
PubMed1998

Effect of natural interferon-beta on the growth of melanoma cell lines.

Malignant melanoma is one of the fulminant skin cancers. The 5-year survival of patients with stage III (N0, N1) malignant melanoma treated with multi-agent chemoimmunotherapy, including natural interferon-beta (nIFNbeta), was found in our department to be better than that of patients treated with other forms of therapy. In order to study the effects of nIFNbeta on melanoma, the growth inhibition effect of nIFNbeta was assessed in vitro using the melanoma cell lines, MM8.1, MM28, MM33.1, Bowes and A375-2. The growth of these cell lines was inhibited by nIFNbeta. Incorporation of [3H]thymidine and [3H]uridine was also inhibited by nIFNbeta in a dose-dependent manner. Apoptosis was demonstrated using the TUNEL method in melanoma cell lines cocultured with nIFNbeta. Results showed that nIFNbeta had direct killer activity on melanoma cell lines.

Antineoplastic Agents↗
PubMed1998

Titanium aneurysm clips: mechanical characteristics and clinical trial.

Titanium clip is well documented to reduce the artifact observed in computed tomography (CT) or magnetic resonance (MR) imaging and improve the quality of these images. There are, however, some demerits based on metallic characteristics including large spring portions, lack of long and fenestration clips, and difficulties to produce. We examined the mechanical characteristics of Sugita titanium aneurysm clips (product of 6 aluminium-4 vanadium-titanium) and investigate the safety in clinical use and the imaging quality compared with those of cobalt (Co) alloy clips. On mechanical test, Sugita titanium clips showed no significant difference in closing force compared with the conventional Co alloy clips. The closing force reduced about 10% after 100 times repeated opening in titanium clips in contrast with no remarkable changes in Co alloy clips. Sixty-four patients with ruptured or unruptured cerebral aneurysms (total number of 71 aneurysms) were treated with Sugita titanium clips through the microsurgical technique. None of the unfavorable outcome occurred in related to the titanium clips. Neither clip dislocation nor deformation was experienced in this series during the follow-up period. The clip artifacts seen in CT and MR image were markedly reduced, however, MR angiography had less quality to resolve anatomical structures due to an existence of vessel gap. These results indicate that in spite of some disadvantages, Sugita titanium clips allow safe and beneficial use routinely in aneurysm surgery insofar as the complete clipping is obtained.

Biomechanical Phenomena↗
PubMed1997

Effects of corticosterone on 5-HT1A and 5-HT2 receptor binding and on the receptor-mediated behavioral responses of rats.

The effects of corticosterone after binding to 5-HT1A and 5-HT2 receptors were studied in rats. Binding of [3H]8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) to 5-HT1A receptors in the hippocampus decreased 24 h after both acute and chronic (14 day) administration of CORT (50 mg/kg, s.c.). Chronic, but not acute, CORT treatment increased [3H]ketanserin binding to 5-HT2 receptors in the frontal cortex. Receptor-mediated behavioral responses were also examined following acute and chronic CORT treatment. Flat body posture and hypothermia induced by 8-OH-DPAT, a 5-HT1A receptor agonist, were attenuated following chronic, but not acute, CORT administration. (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), a 5-HT2 receptor agonist, induced wet-dog shakes, but not hyperthermia and this response was increased 24 h after the chronic administration of CORT. These findings indicate that both 5-HT1A and 5-HT2 receptor functions were changed following chronic exposure to high levels of CORT. Such changes in these receptor systems may play an important role in the etiology of affective disorders.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1997

Experimental use of semiconductor diode laser for neuroendoscopic surgery.

The authors demonstrate an experimental use of the newly developed high power aluminium-gallium-arsenide (AlGaAr) diode laser (DIOMED 25, Olympus Optical Company, Tokyo, Japan). The unit consists of a compact body and fiberoptic probes with small accessories. There are two types (contact and non-contact) of probes. Tissue effects on rat liver, femoral artery, and brain tissue were examined. Adding that, we measured the thermal changes on the liver surface produced by the laser beam with a thermography system. For coagulation with the contact probe, 5 or 7 W was adequate but 10 W was too excess because of tissue adhesion. For cutting, low absorption of the laser in less vascularized tissue like brain white matter provided a deeper tissue damage compared with more vascularized tissue. The temperature at the center reached over 100 degrees C during 10 seconds after laser treatment with the cutting probe. These findings suggest that this system proved to be a good candidate for endoscopic hemostasis and cutting with meticulous maneuver.

Animals↗
PubMed1997

[Primary cutaneous lymphoma--mycosis fungoides].

Malignant lymphoma of the skin is a type of extranodal lymphoma with a benign prognosis, in which the main organ involved is the skin. Some 80-90% of the cases in Japan show a T-cell phenotype. Mycosis fungoides and Sézary syndrome are common T-cell lymphomas of the skin. The tumor cells of mycosis fungoides, small and medium-sized cells with cerebriform nuclei, are detected in an epidermo-dermo junction. The tumor cells show CD3, CD4 and CLA, (cutaneous lymphocyte associated antigen) positivity. Various forms of topical therapy, such as topical steroid, photochemotherapy (PUVA), and interferons, have been indicated for the good-risk group (stages I A, I B and II A). Electron-beam irradiation, various chemotherapy, such as low-dose etoposide, low-dose MTX and CPT-11 and deoxy coformycin (DCF) plus IFNs, have been indicated for intermediate-risk group (stage II B, III and IV A). BRMs plus low-dose etoposide, electron-beam irradiation and a multiagent combination chemotherapy, such as MACOP-B, M-BACOD or ProMACE-CytaBOM, have been indicated for the high-risk group (stages IV A and IV B). Cutaneous B cell lymphoma (CBCL) can be diagnosed using a molecular biological assay. The tumor cells of CBCL do not express T-cell antigens such as CD2, CD3 and CD43 and show B-cell antigens such as sIg, CD19, CD20 and CD22. Electron-beam irradiation has been indicated for early-stage CBCL (stages I and II). An effective multiagent combination chemotherapy, such as MACOP-B, M-BACOD or ProMACE-CytaBOM, is required for patients with advanced stage CBCL (stages III and IV).

Antigens, CD↗
PubMed1996

Interleukin-6 (IL-6) in patients with Behçet's disease.

We have examined the levels of interleukin-6 (IL-6) in plasma and supernatants of peripheral blood mononuclear cells (PBMC) from patients with Behçet's disease and healthy controls using a sensitive enzyme-linked immunosorbent assay (ELISA). Plasma IL-6 level was not detected in any subjects. The IL-6 concentrations in culture supernatants of patients with active Behçet's disease were significantly high compared with patients with inactive disease and healthy controls. Moreover, we investigated IL-6 gene expression in cultured PBMC from patients with Behçet's disease. IL-6 gene expression was enhanced in active patients compared with inactive patients. These results show that IL-6 may play a role in the pathogenesis of Behçet's disease.

Adult↗
PubMed1996

Buspirone enhances immobility in the forced swim test in mice.

We studied the effects of buspirone and 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) on duration of immobility in mice in the forced swim test. Buspirone [3-10 mg/kg, intraperitoneally (IP)] potently and dose dependently increased the duration of immobility in mice. In contrast, following a single dose of 8-OH-DPAT (1-3 mg/kg, IP), there was a dose-dependent decrease in the duration of immobility. Pretreatment with the 5-HT synthesis inhibitor p-chlorophenylalanine (200 mg/kg, IP, 3 days before further drug treatment) did not alter the effects of buspirone or 8-OH-DPAT. The increase in the duration of immobility induced by buspirone (3 mg/kg, IP) was blocked by NAN-190 [1-(2-methoxyphenyl)-4-(4-[2-phthalimido]butyl)-piperazine hydrobromide, 1 mg/kg, IP], a postsynaptic 5-HT1A receptor antagonist. However, the effect of 8-OH-DPAT (1 mg/kg, IP) was not blocked by NAN-190 (1 mg/kg, IP). The effect of buspirone (3 mg/kg, IP) was blocked by apomorphine (0.3 mg/kg, IP), a dopamine receptor agonist. Based on the results of this study, it is suggested that the effects of buspirone and of 8-OH-DPAT on immobility in the forced swim test may occur through different mechanisms.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1995

Chronic forced swim stress of rats increases frontal cortical 5-HT2 receptors and the wet-dog shakes they mediate, but not frontal cortical beta-adrenoceptors.

We studied the effects of chronic forced swim stress on 5-HT2 receptors and beta-adrenoceptors in the rat frontal cortex. The number of 5-HT2 receptors was increased immediately after the last chronic stress, but not after an acute stress. In vivo, the number of wet-dog shakes induced by a 5-HT2 receptor agonist, (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), was increased 24 h after the last chronic stress. However, the concentrations of 5-HT and 5-hydroxyindole acetic acid (5-HIAA), measured by high pressure liquid chromatography (HPLC), were not altered by this stress. Binding sites for [3H]CGP-12177, i.e., beta-adrenoceptor sites, were unchanged after both the acute and the chronic stress. These results suggest that, in the rat, the chronic forced swim stress increases the number of frontal cortical 5-HT2 receptors and the number of wet-dog shakes mediated by these receptors, while the number of frontal cortical beta-adrenoceptors is not increased by this treatment.

Amphetamines↗
PubMed1995

Anaplastic large cell lymphomas expressing the novel chimeric protein p80NPM/ALK: a distinct clinicopathologic entity.

Anaplastic large cell lymphoma (ALCL) is a subtype of non-Hodgkin's lymphoma characterized by the CD30+ large neoplastic cells and sometimes carries a t(2;5)(p23;q35). Recently, we found a novel hyperphosphorylated 80-kD protein tyrosine kinase, p80, in ALCLs with t(2;5). Subsequent cDNA cloning showed p80 to be a fusion protein of two genes, the novel tyrosine kinase gene and the nucleophosmin gene, in accordance with the sequence of the NPM/ALK gene (Morris et al, Science 263:1281, 1994). Meanwhile, the clinicopathologic features of p80-carrying ALCLs have remained unclear. Paraffin sections of 105 cases of ALCL were immunostained using anti-p80 antibody, and 30 of them were shown to express p80. Clinicopathologic comparison between p80-positive and -negative ALCLs showed that p80-positive cases occurred in a far younger patient age group (16.2 +/- 12.9 years; p80-negative cases, 51.0 +/- 22.3 years; P < .0001) and the patients showed a far better 5-year survival rate (79.8%; p80-negative group, 32.9%; P < .01). These data showed that p80-positive ALCL is a distinct entity both clinically and pathogenetically and should be differentiated from p80-negative ALCL.

Adolescent↗
PubMed1995

Low expression of adhesion molecules in a case of cutaneous T-cell lymphoma.

A case of cutaneous T-cell lymphoma (CTCL) with low expression of the adhesion molecules lymphocyte function-associated antigen-1 (LFA-1), intercellular adhesion molecule-1 (ICAM-1), and very late antigen-4 (VLA-4) is described. The patient was a 90-year-old man with red round homogeneous tumors on his scalp, trunk, and extremities. He had no history of definite erythema or plaque stage. A biopsy sample taken from a tumor revealed massive infiltration of atypical lymphocytes in the reticular dermis and subcutis with a definite clear zone. The atypical lymphocytes were medium-sized with slightly convoluted nuclei. Immunohistochemically, the infiltrates showed the phenotype of so-called memory T cells. On the basis of these features, the case was diagnosed as CTCL. Expression of LFA-1, ICAM-1 and VLA-4 on the infiltrates was 9%, 13% and 11%, respectively, which is much lower than that in classic mycosis fungoides. This finding suggests that loss of these adhesion molecules may contribute to loss of epidermotropism in the advanced stage of CTCL.

Aged↗
PubMed1995

Acute revascularization for bihemispheric anterior cerebral artery thrombosis--case report.

A 65-year-old male presented with rapidly progressive paraparesis and akinetic mutism due to occlusion of the bihemispheric anterior cerebral artery (ACA). He was treated by intra-arterial thrombolytic therapy but reocclusion of the arteriosclerotic lesion occurred. Bilateral superficial temporal artery (STA)-ACA anastomoses achieved lasting neurological improvement. Bilateral STA-ACA anastomoses are quite effective to prevent ischemia of the bilateral ACA territories.

Aged↗