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Biomedical subjects

T Tanimoto

Publications and source records attributed to T Tanimoto.

At least 73 records · Page 4Linked to original sources

Effects of N-methyl-D-aspartate (NMDA) and non-NMDA receptor antagonists on excitation of the tooth-pulp-evoked C1 spinal neurons in the rat.

To examine whether there is a difference between the effects of iontophoretically applied N-methyl-D-aspartate (NMDA) and non-NMDA receptor antagonists on the activity of C1 spinal neurons with input from the tooth pulp, extracellular single recordings were performed in pentobarbital-anesthetized rats. The activity of 16 C1 spinal neurons and the amplitude of the digastric electromyogram increased proportionally by 1.0-3.5 times the threshold for jaw-opening reflex. After iontophoretic application (10, 30 and 50 nA, 5 min) of NMDA receptor blocker (5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a, d]cycloheptene-5,10-imine hydrogen maleate or non-NMDA receptor blocker (6-cyano- 7-nitroquinoxaline-2,3-dione), the mean number of spikes responding to the tooth pulp stimulation at x3.5 threshold for jaw-opening reflex was significantly decreased. Under these conditions, there were no significant differences between the amplitudes of the dEMG before and after applications of both NMDA and non-NMDA receptor antagonists. These results suggest that the release of endogenous excitatory neurotransmitters is necessary for activation of C1 spinal neurons that are associated with the transmission of nociceptive information, and that both NMDA and non-NMDA receptors contribute to the mechanism of excitation of tooth-pulp-evoked C1 spinal neurons.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

Serovar, pathogenicity and antimicrobial susceptibility of erysipelothrix rhusiopathiae isolates from farmed wild boars (Sus scrofa) affected with septicemic erysipelas in Japan.

Six strains of Erysipelothrix rhusiopathiae were isolated from farmed wild boars with acute septicemic erysipelas during the period from 1983 to 1998 in Japan. All isolates belonged to serovar 1a or 2 (predominant serovars in swine). The 50 per cent lethal dose values of those isolates ranged from 10(1.3)to 10(6.2)colony forming units in mice. In swine, all isolates were virulent, capable of inducing localized or generalized urticarial lesions after intradermal inoculation. All of the isolates were resistant to oxytetracycline and/or dihydrostreptomycin. These observations suggest that E. rhusiopathiae strains isolated from wild boars may have aetiological significance in swine erysipelas.

Animals↗

Involvement of interleukin-18 (IL-18) in mixed lymphocyte reactions (MLR).

The in vitro mixed lymphocyte reaction (MLR) is a useful model to study alloresponsiveness to histocompatibility antigens. Secretion of different cytokine proteins in the supernatant of allo-MLR cultures has been reported in a few studies. We studied the levels of the cytokines interferon gamma (IFN-gamma) and interleukin-6 (IL-6), IL-10, IL-12, and IL-18 in the supernatant in allo-MLR by ELISA assay. Supernatant levels of IFN-y, IL-6, IL-10, and IL-18 were detected at 12 h after MLR and markedly increased thereafter. In contrast, secretion of IL-12 was detected after 48-72 h. These results suggested that IFN-gamma production depended on IL-18 in the early phase of MLR and depended on both IL-18 and IL-12 in the late phase. An antibody (Ab) neutralizing test was also performed. The levels of IFN-gamma were significantly downregulated after the addition of anti-IL-18 Ab, anti-IL-12 Ab, or anti-IFN-y Ab, and the levels of IL-12 were significantly downregulated after the addition of anti-IL-12 Ab and anti-IL-18 Ab. Treatment with these Ab did not suppress IL-6 production at all. The two-way MLR showed the same tendency as the one-way MLR. These results suggest the importance of IL-18 and IL-12 in allogeneic cell interactions and also suggest the usefullness of these Ab as regulators of alloresponsiveness.

Culture Media↗

MUC1 expression in intramucosal colorectal neoplasms. Possible involvement in histogenesis and progression.

PURPOSE: The mucin core peptide MUC1 often is detectable in colorectal carcinoma (CRC) tissue and cell lines. However, whether MUC1 in CRC correlates with tumor histogenesis and progression is unclear. We studied the relationship between MUC1 expression in intramucosal CRC and clinicopathologic features, expression of Ki-67, and p53 protein, and apoptosis. METHODS: The intramucosal CRC we studied included 140 endoscopically or surgically resected lesions, including 106 low-grade carcinomas and 34 high-grade carcinomas. De novo carcinoma, defined as carcinoma with no adenomatous component, represented 9 of 140 tumors. Three macroscopic types were identified: 57 lesions were polypoid, 55 were superficial and flat, and 28 were granular-type laterally spreading tumors (G-LST). MUC1, Ki-67, and p53 expression were examined immunohistochemically. Apoptotic cells were identified by in situ DNA nick end labeling. RESULTS: MUC1 expression in high-grade carcinomas was significantly more frequent (p < 0.01) than in low-grade carcinomas; expression in adenomas was almost nil. MUC1 expression in polypoid carcinomas was significantly more frequent (p < 0.05) than in superficial carcinomas or G-LST. MUC1 expression in carcinomas with p53 expression was significantly more frequent (p < 0.01) than in carcinomas not expressing p53. No significant correlation was found between expression of MUC1 and Ki-67 labeling index. MUC1 was expressed more frequently in carcinomas with relatively high apoptotic index (p < 0.01). MUC1 expression did not differ between de novo carcinomas and those developing from adenomas. CONCLUSIONS: The results suggest that MUC1 is likely to be expressed in the course of colorectal carcinoma development when p53 protein is overexpressed and apoptosis is prominent.

Apoptosis↗

Enzymatic synthesis of N-acetylglucosaminyl-cyclodextrin by the reverse reaction of N-acetylhexosaminidase from jack bean.

Novel heterobranched cyclodextrins (CDs), N-acetylglucosaminyl-cyclodextrins (GlcNAc-CD), were synthesized from a mixture of GlcNAc and alpha, beta, or gamma CD by the reverse reaction of N-acetylhexosaminidase from jack bean. Optimum pH and temperature for the production of GlcNAc-alpha CD by N-acetylhexosaminidase were pH 4.9 and 50-70 degrees C, respectively. The maximum yield of GlcNAc-alpha CD was 17.5% (mol/mol) at the concentration of 1 M GlcNAc and 0.25 M alpha CD. The reverse reaction product, GlcNAc-alpha CD, was separated into two peaks by HPLC analysis on the ODS column. Their structures were identified as 6-O-beta-D-N-acetylglucosaminyl-alpha CD and 2-O-beta-D-N-acetylglucosaminyl-alpha CD by FAB-MS and NMR spectroscopies. N-Acetylhexosaminidase from jack bean also synthesized N-acetylgalactosaminyl-alpha CD from N-acetylgalactosamine and alpha CD.

Chromatography↗

Changes in c-Fos expression induced by noxious stimulation in the trigeminal spinal nucleus caudalis and C1 spinal neurons of rats after hyperbaric exposure.

The present study aims to test the hypothesis that hyperbaric exposure inhibits nociceptive processing in the trigeminal spinal nucleus caudalis and C1 spinal neurons. We investigated the c-Fos-like immunoreactivity of the brainstem and upper cervical spinal cord (C1 region) following an injection of mustard oil (15 microliters of 20%) into the nasal mucosa of pentobarbital anesthetized rats after exposure to hyperbaric (2-atmospheres, 1 h) and normobaric pressures. After the hyperbaric exposure, the mean number of Fos-immunoreactive neurons in the ipsilateral laminae I-II and III-IV of the trigeminal spinal nucleus caudalis were significantly lower than those in the normobaric condition. Similarly, the mean number of c-Fos positive neurons in the superficial layer (I-II) of the ipsilateral C1 segment were significantly reduced as compared with that in the normobaric condition. When treated with the vehicle alone, no significant difference was detected in the numbers of c-Fos positive neurons in the trigeminal spinal nucleus caudalis and C1 regions between hyperbaric and normobaric conditions. These results suggest that hyperbaric exposure may attenuate nociceptive signals from the area innervated by the trigeminal nerves at the level of both the trigeminal spinal nucleus caudalis and C1 dorsal horn.

Animals↗

[Inhibition of antigen-specific T helper type 2 responses by Perilla frutescens extract].

Perilla frutescens leaf extract (PFE) is known as a natural medicine with anti-allergic activities, although its mechanism of action remains unclear. In this study, we examined the effect of PFE on antigen-specific antibody and on cytokine production. Mice were immunized three times (weekly) with sugi basic protein (SBP), a major allergen of Japanese cedar pollen, in alum adjuvant. PFE was injected intraperitoneally into mice on day 2 before and on the day of each immunization with SBP in alum adjuvant. Serum anti-SBP IgE and IgG 1 antibody levels were significantly suppressed in mice injected with PFE. Furthermore, the production of interleukin (IL)-4, IL-5 and IL-10 by SBP-stimulated splenocyses also decreased in PFE-injected mice in a dose-dependent manner. However, PFE had no effect on either the serum anti-SBP IgG 2 a antibody levels or on interferon (INF)-gamma production by splenocytes. When splenocytes were stimulated with concanavalin A, there was no difference in cytokine production between mice injected with PFE and control mice injected with vehicle. SBP-specific T cell line established in the presence of PFE from the lymph node cells of mice immunized with SBP showed reduced IL-4, IL-5 and IL-10 production compared with that established in the absence of PFE. In contrast, comparable levels of IFN-gamma production were observed between these two T cell lines. These data suggest that PFE down-regulates Th 2-type cytokine production and prevents the Th 1/Th 2 balance from polarizing toward Th 2-type immune responses.

Animals↗

[A case of gastric stromal tumor with chest pain and diaphragm elevation].

A 66-year-old woman presented with left chest pain. Left pleural effusion was seen on a chest X-ray film and a large mass disclosed by chest computed tomography. However, the patient refused to undergo a recommended operation. Six months later, she was admitted without any symptoms. A huge (18 cm diameter) mass was detected by magnetic resonance imaging (MRI), and consisted of heterogeneous solid and cystic components. Angiography and endoscopic sonography disclosed a suspected abdominal tumor, which was resected by thoracolaparotomy. Gastric stromal tumor was diagnosed on the basis of histological findings. Chest pain and pleural effusion are rare as initial clinical symptoms of such tumors.

Aged↗

[Saliva production in patients with diffuse lung disease].

We explored the potential involvement of Sjögren's syndrome as a cause of diffuse lung disease. A prospective clinical study was performed with measurements of saliva production made using the Saxon test. Sixty-seven diffuse lung disease patients who did not exhibit xerosis were examined. The group included 43 patients with sarcoidosis, 11 with interstitial pneumonia, 3 with primary pulmonary lymphoma (PPL), 2 with idiopathic BOOP, 2 with chronic eosinophilic pneumonia, and 6 with other diseases. Decreased saliva production was detected in 11 (16.4%), and Sjögren's syndrome was diagnosed in 4 (6.0%). Lung lesions displayed by the group with Sjögren's syndrome included PPL, bronchiolitis, sarcoidosis, and interstitial pneumonia. We concluded that in patients with diffuse lung diseases, it is always important to discriminate between those with sicca syndrome and Sjögren's syndrome. In our study, the Saxon test proved highly effective as a screening procedure for this purpose.

Adult↗

Effects of potassium channel blockers on CO2-induced slowly adapting pulmonary stretch receptor inhibition.

In anesthetized, artificially ventilated rabbits with vagus nerve section, inhalation of CO(2) gas mixtures (tracheal CO(2) concentration ranging from 8.0 to 10.2%) for 60 s decreased slowly adapting pulmonary stretch receptor (SAR) activity during both inflation and deflation. The magnitude of decreased receptor activity during deflation had a more pronounced effect than that seen during inflation. CO(2) inhalation did not cause any significant change in tracheal pressure (P(T)) as an index of bronchomotor tone. Intravenous administration of 4-aminopyridine (0. 7 and 2.0 mg/kg i.v.), a K(+) channel blocker, which dose-dependently increased SAR activity during deflation and had no effect on P(T), abolished or attenuated the decrease in SAR activities induced by CO(2) inhalation in a dose-dependent manner. The K(+) channel blocker tetraethylammonium (2.0 and 6.0 mg/kg i.v.) that did not significantly alter either basal SAR discharge or P(T) had no effect on the inhibitory responses of receptor activity to CO(2) inhalation. These results suggest that the inhibitory mechanism of CO(2) inhalation on SARs may be involved in the activation of 4-aminopyridine-sensitive K(+) channels in the nerve terminals of SARs.

4-Aminopyridine↗

[Triamcinolone Acetonide Reference Standard (Control 981) of National Institute of Health Sciences].

The raw material of triamcinolone acetonide was examined for preparation of the "Triamcinolone Acetonide Reference Standard (Control 981)". The analytical data obtained were: melting point, 289 degrees C (decomposition); UV spectrum, lambda max of 238 nm; IR spectrum, same as that of the Triamcinolone Acetonide Reference Standard (Control 834); optical rotation, [alpha]D20 = +106.8 degrees; thin-layer chromatography, no impurities detected; high-performance liquid chromatography, total amount of impurities less than 0.4%; loss on drying, 1.3%; assay by HPLC, 100.1%. Based on the above results, the raw material was authorized as the Triamcinolone Acetonide Reference Standard (Control 981) of the National Institute of Health Sciences.

Government Agencies↗

[Triamcinolone Reference Standard (Control 981) of National Institute of Health Sciences].

The raw material of triamcinolone was examined for preparation of the "Triamcinolone Reference Standard (Control 981)". The analytical data obtained were: melting point, 246 degrees C (decomposition); UV spectrum, lambda max of 239 nm and specific absorbance in methanol at 289 nm of 394; IR spectrum, specific absorptions at 3462, 1716, 1659, 1615, 1604, 1132 and 1061 cm-1; optical rotation, [alpha]D20 = +69.7 degrees; high-performance liquid chromatography, five impurities detected and amount of each impurity estimated to be less than 0.6% and total amount of impurities less than 1.4%; loss on drying, 0.24%. Based on the above results, the raw material was authorized as the Triamcinolone Reference Standard (Control 981) of the National Institute of Health Sciences.

Government Agencies↗

[Digoxin Reference Standard (Control 991) of National Institute of Health Sciences].

The raw material of digoxin was examined to prepare a "Digoxin Reference Standard". The analytical data obtained were: optical rotation, [alpha](20)D = + 11.7 degree; loss on drying, 0.008%, infrared spectrum, the same as that of the Digoxin Reference Standard (Control 807); high-performance liquid chromatography, several impurities detected and the total amount estimated to be about 0.31%, assay by spectrophotometry, 100.1%. Based on the above results, the candidate material was authorized as the Digoxin Reference Standard (Control 991) of the National Institute of Health Sciences.

Digoxin↗

[Lanatoside C Reference Standard (Control 981) of National Institute of Health Sciences].

The raw material of lanatoside C was examined for preparation of the "Lanatoside C Reference Standard". The analytical data obtained were: melting point, 247.4 degree C; optical rotation, [alpha]20(D) = + 34.0 degree, loss on drying, 6.93%; infrared spectrum, the same as that of the Lanatoside C Reference Standard (Control 784); thin-layer chromatography, two impurities detected; high-performance liquid chromatography, several impurities detected and the total amount estimated to be about 1.26%; assay by spectrophotometry, 103.0%. Based on the above results, the candidate material was authorized as the Lanatoside C Reference Standard (Control 981) of the National Institute of Health Sciences.

Government Agencies↗

[Glycyrrhizic Acid Reference Standard (Control 991) of National Institute of Health Sciences].

The raw material of glycyrrhizic acid examined for preparation of the "Glycyrrhizic Acid Reference Standard". The analytical data obtained were: UV spectrum: Lambda max, 251 nm; specific absorbance (E (1%) 1cm) in ethanol at 251 nm, 146; IR spectrum, specific absorptions at 1716,1656, 1215, and 1170 cm-1; and the spectrum of raw material was consistent with that of Standard (Control 941). Also, thin-layer chromatography, no impurities detected; high-performance liquid chromatography, three impurities detected. The amount of each impurity was estimated at less than 0.1%, and the total amount of impurities was less than 0.2%. Based on the above results, the candidate material was authorized as the Glycyrrhizic Acid Reference Standard (Control 991) of the National Institute of Health Sciences.

Glycyrrhizic Acid↗

[Tocopherol Succinate Reference Standard (Control 981) of National Institute of Health Sciences].

The raw material of tocopherol succinate was tested for preparation of the "Tocopherol Succinate Reference Standard (Control 981)". The analytical data obtained were: infrared spectrum same as that of the Tocopherol Succinate Reference Standard (Control 8510); specific absorbance, E(1%)1 cm (286 nm) = 40.7; thin-layer chromatography, no impurities detected until 50.0 microgram; high-performance liquid chromatography (HPLC),three impurities detected and amount of tocopherol succinate estimated to be 98.2%, loss on drying, 0.19%, assay by HPLC, 101.7%. Based on the above results, the raw material was authorized as the Japanese Pharmacopoeia Reference Standard (Control 981).

Government Agencies↗

[Fluocinolone Acetonide Reference Standard (Control 981) of National Institute of Health Sciences].

The raw material of fluocinolone acetonide was examined for preparation of the "Fluocinolone Acetonide Reference Standard (Control 981)". The analytical data obtained were: melting point, 271.5 degree C; UV spectrum, Lambda max of 237.0 nm and specific absorbance in ethanol at 237 nm of 359.3; IR spectrum, same as that of the Fluocinolone Acetonide Reference Standard (Control 904); optical rotation, [alpha]20(D) = + 102.8; thin-layer chromatography, no impurities detected; high-performance liquid chromatography, one impurity detected and total amount estimated to be about 0.17%; loss on drying, 0.29%; assay by HPLC, 100.9%. Based on the above results, the raw material was authorized as the Fluocinolone Acetonide Reference Standard (Control 981) of the National Institute of Health Sciences.

Fluocinolone Acetonide↗

[Fluocinonide Reference Standard (Control 981) of National Institute of Health Sciences].

The raw material of fluocinonide was examined for preparation of the "Fluocinonide Reference Standard (Control 981)". The analytical data obtained were: UV spectrum, lambda max of 237.4 nm; IR spectrum, same as that of the Fluocinonide Reference Standard (Control 841); optical rotation, [alpha]20(D) = + 84.4 degree, thin-layer chromatography, one impurity detected; high-performance liquid chromatography, three impurities detected and total amount estimated to be about 0.20%; loss on drying, 0.15%; assay by HPLC, 99.6% Based on the above results, the raw material was authorized as the Fluocinonide Reference Standard (Control 981) of the National Institute of Health Sciences.

Fluocinonide↗