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Biomedical subjects

T Tanabe

Publications and source records attributed to T Tanabe.

At least 145 records · Page 8Linked to original sources
PubMed1999

[Clinicopathological evaluation of intralaryngeal ultrasonography].

We used a miniature ultrasonic probe to study its diagnostic application in the detection of laryngeal lesions. Using the immersion method and an extracted human larynx, we evaluated ultrasonic images, identified the layered structure of vocal folds, and examined clinical cases following the study of diagnostic application. By the immersion method, ultrasonic images revealed that the membranous vocal fold was separated into three layers. We identified the histological structures of these three layers by comparing the ultrasonic images with the corresponding histologies. The first layer (hyperechoic) was the epithelial and the superficial layer of the lamina propria; the second layer (hypoechoic) was the vocal ligament; and the third layer (hyperechoic) was the deep layer of the lamina propria. On the basis of this study, we then evaluated ultrasonographic images of clinical cases. Benign lesions such as vocal nodules or vocal polyps were noted on the layered structure of the mucosa, especially, polyps as hyperechoic images. Furthermore, glottic cancer lesions demonstrated hypoechoic images and sometimes revealed destruction of the layered structures. These results suggest that intralaryngeal ultrasonography can be useful as a clinical application for the detection of tumor involvement in the vocal folds.

Aged↗
PubMed1999

[Problems of intravenous lidocaine treatment in status epilepticus or clustering seizures in childhood].

Lidocaine was administered intravenously as a substitute for diazepam, to 12 patients with status epilepticus or clustering seizures aged 26 days to 11 years. The medication was very effective in 3 cases with acute convulsions, which disappeared immediately after infusion of lidocaine without relapse. The medication was effective only temporarily in 4 patients; they experienced relapsing seizures during drip infusion of lidocaine intravenously for maintenance. All the relapsing seizures were secondarily generalized ones with diffuse ictal discharges. In 2 cases of localization-related epilepsy, complex partial seizures evolved to secondarily generalized seizures immediately after administration of lidocaine. It must be noticed that in a relatively large number of cases lidocaine is ineffective or even harmful.

Anticonvulsants↗
PubMed1999

UFT and mitomycin plus tamoxifen for stage II, ER-positive breast cancer. Hokkaido ACETBC Study Group.

A trial was designed to examine the combination of UFT and mitomycin (Mutamycin) plus tamoxifen (Nolvadex) as postoperative adjuvant therapy in the treatment of patients with stage II, estrogen receptor (ER)-positive primary breast cancer. Mitomycin was administered intravenously at 13 mg/m2 on the day of surgery. Patients judged to be ER-positive were randomly allocated to either group A, which received oral tamoxifen 20 mg/day 14 days after surgery for 2 years, or group B, receiving oral UFT 400 mg/day plus tamoxifen 20 mg/day. A total of 219 patients were enrolled in group A, of which 213 (97.3%) were determined to be eligible; 225 patients enrolled in group B and 223 (99.1%) were eligible. The 5-year survival rates were 93.0% for group A and 95.4% for group B, with no significant difference between groups. The 5-year relapse-free survival rates were 83.1% for group A and 90.7% for group B, a significant advantage (P = .020) for the UFT plus tamoxifen group. Combination therapy with mitomycin, tamoxifen, and UFT proved to be an effective postoperative chemoendocrine therapy for stage II, ER-positive breast cancer.

Adult↗
PubMed1999

Clear-cell basal cell carcinoma of the upper eyelid: a case report.

A clear-cell variant of basal cell carcinoma in a previously unreported site is described. This rare variant appeared on the upper eyelid of an 81-year-old woman. Light microscopic examination showed an intradermal tumor with circumscribed lobules composed of clear cells. Histological differential diagnosis of tumors with clear-cell formation is often confusing and can have a great influence on treatment decision making, including surgical intervention.

Adenocarcinoma, Clear Cell↗
PubMed1999

[A case of advanced gastric cancer with abdominal para-aortic lymph node metastasis successfully treated with FLP therapy].

A 73-year-old woman was admitted to our hospital in June 1998, suffering from upper abdominal pain. The upper G-I series and endoscopic examination revealed stenosis of the pylorus and antrum by a type 2 cancer, and a poorly differentiated adenocarcinoma and a signet-ring cell carcinoma were confirmed on endoscopic biopsy. A CT scan showed the enlargement of many regional and abdominal para-aortic lymph nodes. FLP therapy combined with cisplatin (50 mg/m2 drip i.v., day 1-8), 5-fluorouracil (333 mg/m2 drip i.v.) and leucovorin (30 mg/body i.v., day 1-8) was planned for neoadjuvant chemotherapy (NAC) in order to reduce or eliminate the tumor and increase curability. After two cycles of the FLP therapy, the tumor size shrunk remarkably and the enlargement of the para-aortic lymph nodes disappeared. Distal gastrectomy with extended lymphadenectomy and cholecystectomy was performed. The histological findings of the primary tumor and metastatic lymph nodes demonstrated massive cancer cell degeneration such as pycnosis and vacuolation, xanthogranulomatous inflammation and dense fibrosis. The effect of NAC was judged to be grade 2 histologically. FLP therapy is an effective and safe regimen for NAC.

Adenocarcinoma↗
PubMed1999

Effect of age on rat aortic responses to acetylcholine and nitric oxide donor (NOC-18).

The purpose of the present study was to examine the effects of age on vascular responses to acetylcholine (ACh) and NO-releasing compound (NOC-18). The studies were performed in young (4 mo old, n = 8) and old (22 mo old, n = 6) male rats. Responses to ACh and NOC-18 were examined in vitro by using isolated abdominal aortic rings. The maximum relaxation response to ACh, an endothelium-dependent vasodilation, was lower in aortas from old rats. Sensitivity (mean effective concentration; EC50) of ACh in old rats was significantly less than in young rats. There were no differences in maximum NOC-18-induced relaxation, an endothelium-independent vasodilation, in aortas from young and old rats. On the other hand, the concentration-response curve for NOC-18 was shifted to the right and the sensitivity (EC50 to NOC-18) was lower in old rats. These results indicated that both endothelium-dependent vasodilation induced by ACh and endothelium-independent vasodilation induced by NOC-18 are impaired in aorta from old rats.

Acetylcholine↗
PubMed1998

IFNgamma inhibition of cell growth in glioblastomas correlates with increased levels of the cyclin dependent kinase inhibitor p21WAF1/CIP1.

Glioblastoma is a highly aggressive form of brain cancer characterized by uncontrolled cell growth resulting from a loss of cell cycle regulation. In this study we determined the antiproliferative effects of interferon gamma (IFNgamma) on the glioblastoma cell lines T98G, SNB-19 and U-373, focusing on the ability of IFNgamma to increase levels of p21WAF1/CIP1, an important negative regulator of cell cycle events. IFNgamma was found to inhibit the growth of all cell lines, with inhibition ranging from 82.2% to 45.4%. Flow cytometry analysis showed that IFNgamma treatment caused a cell cycle delay in the G1 or S phases. The strength of this delay varied, correlating with the degree by which IFNgamma inhibited proliferation of each cell line. IFNgamma treatment increased the production of the cyclin dependent kinase inhibitor (CKI) p21WAF1/ CIP1 in all cell lines, the level and kinetics of production of which correlated with the degree and stage of inhibition of cellular proliferation. Further, immunoprecipitation of p21WAF1/CIP1 in complexes of p21WAF1/CIP1/cyclin-dependent kinase 2 (cdk2)/cyclin showed that the amount of p21WAF1/CIP1 in the complexes and the inhibition of cdk2-cyclin kinase activity correlated with the level of p21WAF1/CIP1 produced in the cells by IFNgamma. These results show that IFNgamma has significant antiproliferative effects on the glioblastoma cell lines and suggest that p21WAF1/CIP1 plays a role in mediating these effects.

CDC2-CDC28 Kinases↗
PubMed1998

Localization in the II-III loop of the dihydropyridine receptor of a sequence critical for excitation-contraction coupling.

Skeletal and cardiac muscles express distinct isoforms of the dihydropyridine receptor (DHPR), a type of voltage-gated Ca2+ channel that is important for excitation-contraction (EC) coupling. However, entry of Ca2+ through the channel is not required for skeletal muscle-type EC coupling. Previous work (Tanabe, T., Beam, K. G., Adams, B. A., Niidome, T., and Numa, S. (1990) Nature 346, 567-569) revealed that the loop between repeats II and III (II-III loop) is an important determinant of skeletal-type EC coupling. In the present study we have further dissected the regions of the II-III loop critical for skeletal-type EC coupling by expression of cDNA constructs in dysgenic myotubes. Because Ser687 of the skeletal II-III loop has been reported to be rapidly phosphorylated in vitro, we substituted this serine with alanine, the corresponding cardiac residue. This alanine-substituted skeletal DHPR retained the ability to mediate skeletal-type EC coupling. Weak skeletal-type EC coupling was produced by a chimeric DHPR, which was entirely cardiac except for a small amount of skeletal sequence (residues 725-742) in the II-III loop. Skeletal-type coupling was stronger when both residues 725-742 and adjacent residues were skeletal (e.g. a chimera containing skeletal residues 711-765). However, residues 725-742 appeared to be critical because skeletal-type coupling was not produced either by a chimera with skeletal residues 711-732 or by one with skeletal residues 734-765.

Amino Acid Sequence↗
PubMed1998

Resveratrol inhibits cyclooxygenase-2 transcription and activity in phorbol ester-treated human mammary epithelial cells.

We determined whether resveratrol, a phenolic antioxidant found in grapes and other food products, inhibited phorbol ester (PMA)-mediated induction of COX-2 in human mammary and oral epithelial cells. Treatment of cells with PMA induces COX-2 and causes a marked increase in the production of prostaglandin E2. These effects were inhibited by resveratrol. Resveratrol suppressed PMA-mediated increases in COX-2 mRNA and protein. Nuclear run-offs revealed increased rates of COX-2 transcription after treatment with PMA, an effect that was inhibited by resveratrol. PMA caused about a 6-fold increase in COX-2 promoter activity, which was suppressed by resveratrol. Transient transfections utilizing COX-2 promoter deletion constructs and COX-2 promoter constructs, in which specific enhancer elements were mutagenized, indicated that the effects of PMA and resveratrol were mediated via a cyclic AMP response element. Resveratrol inhibited PMA-mediated activation of protein kinase C. Overexpressing protein kinase C-alpha, ERK1, and c-Jun led to 4.7-, 5.1-, and 4-fold increases in COX-2 promoter activity, respectively. These effects also were inhibited by resveratrol. Resveratrol blocked PMA-dependent activation of AP-1-mediated gene expression. In addition to the above effects on gene expression, we found that resveratrol also directly inhibited the activity of COX-2. These data are likely to be important for understanding the anti-cancer and anti-inflammatory properties of resveratrol.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

Cloning and expression of the gene for a vanadium-dependent bromoperoxidase from a marine macro-alga, Corallina pilulifera.

The cDNAs for a vanadium-dependent bromoperoxidase were cloned from a marine macro-alga, Corallina pilulifera. The open reading frame of one clone (bpo1) encoded a protein of 598 amino acids with a calculated molecular mass of 65312 Da in good agreement with that of 64 kDa determined for the native enzyme. The deduced amino acid sequence coincided well with partial sequences of peptide fragments of the enzyme. From the same cDNA library we also isolated another cDNA clone (bpo2) encoding a protein of 597 amino acids with an identity of about 90% to BPO1, suggesting a genetic diversity of the bromoperoxidase gene of C. pilulifera growing in a relatively narrow area. The carboxy-terminal 123 residues of the enzyme (BPO1) showed an identity of 45% to that of the marine macro-alga Ascophillum nodosum. The homology search of the sequences of bromoperoxidases from C. pilulifera (this study) and A. nodostum, and chloroperoxidase from the fungus Curvularia inaequalis indicated highly conserved sequences PxYxSGHA and LxxxxAxxRxxxGxHxxxD. Furthermore, it was found that the histidine residue directly bound to vanadium, other residues building up the metal center and catalytic histidine residue forming the active site of the chloroperoxidase from C. inaequalis are conserved in the primary structure of the bromoperoxidase from C. pilulifera. The cloned hpol was introduced into Escherichia coli, and the expressed PO1 was purified from the recombinant strain. The N-terminal amino acid sequence of the purified BPO1 was identical to the deduced sequence from the cDNA except the N-terminal methionine.

Amino Acid Sequence↗
PubMed1998

Initial results from an in-vacuum undulator in the NSLS X-ray ring.

A short-period in-vacuum undulator for the NSLS X-ray Ring has been developed in a collaboration between SPring-8 and the NSLS, and has achieved its project design goals during commissioning studies. The device is called IVUN (in-vacuum undulator) and employs magnet arrays (31 periods, with an 11 mm period) developed at SPring-8, while the requisite vacuum chamber and mechanical systems were developed at the NSLS. At a magnet gap of 3.3 mm, IVUN produces 4.6 keV radiation in the fundamental, with useful photon fluxes in both the second and third harmonics. The magnet gap is adjustable between 2 and 10 mm. A brief overview of IVUN is presented, together with initial commissioning results: the dependence of electron-beam lifetime and bremsstrahlung on magnet gap, and the output radiation spectrum.

Journal Article↗
PubMed1998

Rotating/Helmholtz coil system using a lock-in amplifier method.

Measurement of integrated magnetic induction is an important part of the construction of insertion devices. The so-called 'flipping coil system' is normally utilized to characterize the integrated multipole components of the device, a requirement which varies from one storage ring to another. A Helmholtz coil system is used to determine a magnetization vector of each magnet piece in the device. Both systems are designed to measure the integrated magnetic flux to deduce the necessary quantities using the known relationship. We have developed an unconventional system which has a continuously rotating mechanism that allows the use of a lock-in amplifier instead of an integrator or a voltmeter. Detailed descriptions of the equipment are given.

Journal Article↗
PubMed1998

In-vacuum figure-8 undulator for hard X-rays with both horizontal and vertical polarization.

A figure-8 undulator of the in-vacuum type has been adopted as an insertion device for BL24XU, the Hyogo Beamline at SPring-8, to provide hard X-rays with both horizontal and vertical polarization instead of a tandem undulator consisting of horizontal and vertical undulators. The undulator will be operated with the gap almost fixed at 11.6 mm to provide the fundamental radiation with horizontal polarization at 9.5 keV and the 1.5th harmonic with vertical polarization at 14 keV.

Journal Article↗
PubMed1998

An insertion device for the soft X-ray photochemistry beamline at SPring-8.

A figure-8 undulator is an insertion device (ID) proposed at SPring-8 to reduce the heat-load problems encountered with ordinary linear undulators. This device is useful when the K value is high in order to obtain low-energy photons as the fundamental of the undulator radiation. It has therefore been adopted as the ID for the soft X-ray photochemistry beamline (BL27SU) at SPring-8 because linearly polarized photons between 100 and 2000 eV are necessary for the experiments on this beamline. The figure-8 undulator for BL27SU is now under construction and, in the first phase of operation, is expected to cover the energy range down to 500 eV. In the second and third phases, the lowest energy may be reduced to 170 and 100 eV, respectively.

Journal Article↗
PubMed1998

Construction of a vertical undulator at SPring-8.

A new-type insertion device (ID) has been constructed for the structural-biology beamline (BL45XU) at SPring-8. The ID consists of two undulators which can provide vertical polarized radiation (vertical undulators). By changing the individual gap of each undulator independently, photons with two different energies can be obtained. Magnetic field measurements show that the maximum horizontal field is 0.49 T and the magnetic performance is as good as expected.

Journal Article↗
PubMed1998

SPring-8 in-vacuum undulator beam test at the ESRF.

Before the commissioning of SPring-8, the in-vacuum hybrid undulator developed at SPring-8 had been brought to the ESRF for the first beam test in the summer of 1996. The purpose of this test was to investigate the influence of the in-vacuum undulator on the beam and check its vacuum system. However, heating by the resistive wall impedance turned out to be a critical issue for the in-vacuum undulators.

Journal Article↗