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Biomedical subjects

H Takeuchi

Publications and source records attributed to H Takeuchi.

At least 271 records · Page 15Linked to original sources
PubMed1998

Reverse transcription-polymerase chain reaction and immunohistochemical study of the expression of fibronectin mRNA in human submandibular salivary gland.

The alternative expression of fibronectin mRNA in submandibular salivary glands was analysed using three groups of polymerase chain reaction probes to amplify the cell-binding domain (CBD), and the extra domain (ED)-A and ED-B exon regions in five normal human adults. The fibronectin CBD region was fairly well expressed in the salivary gland while less than trace amounts of ED-A and ED-B exons were expressed. Immunohistochemical staining with an antihuman plasma fibronectin monoclonal antibody, which recognized specifically the CBD region, demonstrated definite positive cytoplasmic staining in the duct-cell area. On the other hand, an anticellular fibronectin ED-A-specific monoclonal antibody was very low positive in duct cells. The results suggest that salivary fibronectin is synthesized in the submandibular salivary gland only, and does not include the ED-A segment. Furthermore, duct cells also produced fibronectin without ED-A.

Adult↗
PubMed1998

Orientations of tyrosines 21 and 24 in coat subunits of Ff filamentous virus: determination by Raman linear intensity difference spectroscopy and implications for subunit packing.

Virions of the Ff group of bacteriophages (fd, f1, M13) are morphologically identical filaments (approximately 6-nm diameter x approximately 880-nm length) in which a covalently closed, single-stranded DNA genome is sheathed by approximately 2700 copies of a 50-residue alpha-helical subunit (pVIII). Orientations of pVIII tyrosines (Tyr21 and Tyr24) with respect to the filament axis have been determined by Raman linear intensity difference (RLID) spectroscopy of flow-oriented mutant virions in which the tyrosines were independently mutated to methionine. The results show that the twofold axis of the phenolic ring (C1-C4 line) of Tyr21 is inclined at 39.5 +/- 1.4 degrees from the virion axis, and that of Tyr24 is inclined at 43.7 +/- 0.6 degrees. The orientation determined for the Tyr21 phenol ring is close to that of a structural model previously proposed on the basis of fiber x-ray diffraction results (Protein Data Bank, identification code 1IFJ). On the other hand, the orientation determined for the Tyr24 phenol ring differs from the diffraction-based model by a 40 degrees rotation about the Calpha-Cbeta bond. The RLID results also indicate that each tyrosine mutation does not greatly affect the orientation of either the remaining tyrosine or single tryptophan (Trp26) of pVIII. On the basis of these results, a refined model is proposed for the coat protein structure in Ff.

Amino Acid Sequence↗
PubMed1998

Stimulation of interleukin-6 production in human dental pulp cells by peptidoglycans from Lactobacillus casei.

Interleukin-6 (IL-6), which is a multifunctional cytokine, has an important role in acute and chronic inflammation. The peptidoglycan (PG) was purified from Lactobacillus casei, which was a Gram-positive bacteria frequently isolated from deep carious lesions and suspected to be a pathogen of pulpitis. In this study, the effects of PG on the production of IL-6 in human dental pulp cells were examined. PG stimulated IL-6 production in a time- and dose-dependent manner. Reverse transcriptase-polymerase chain reaction experiments showed that the increase was dependent on the enhancement of IL-6 mRNA levels. These findings suggest that Gram-positive bacteria, such as L. casei, from carious lesions, might be involved in developing pulpitis through the stimulation of IL-6 production.

Cells, Cultured↗
PubMed1998

Stimulatory effect of interleukin-6 on plasminogen activator activity from human dental pulp cells.

The plasminogen activator (PA)-plasmin proteolytic system has recently received considerable attention because of its participation in a wide variety of biological activities and in pathological conditions involving tissue destruction. We examined the effects of interleukin-6 (IL-6) on PA activity and the gene expressions of tissue type (t) PA and PA inhibitor-1 (PAI-1) in human dental pulp (HDP) cells. IL-6 treatment induced significantly high PA activity in the HDP cells in a time- and dose-dependent manner, compared with nontreated controls. Western-blot analysis showed that tPA protein in the conditioned medium was stimulated by IL-6, compared with the control. The tPA and PAI-1 mRNA levels were increased in HDP cells treated with IL-6, as shown by reverse transcriptase-polymerase chain reaction. These results suggest that IL-6 stimulated PA activity through an enhancement of tPA gene expression and may be involved in extracellular matrix degradation through the stimulation of the PA-plasmin system of HDP cells.

Blotting, Western↗
PubMed1998

Mechanical strength of calcium phosphate cement in vivo and in vitro.

Two different kinds of calcium phosphate cement were developed for implant fixation: cement A comprised of alpha-tricalcium phosphate (alpha-TCP) 95% and dicalcium phosphate dihydrate (DCPD) 5%, and cement B comprised of alpha-tricalcium phosphate 90% and dicalcium phosphate dihydrate 10%. The compression strength and pullout force of the new materials were tested both in vitro and in vivo. Microscopic observations were performed on the interface between bone and cement. Cement A showed a greater mechanical strength than cement B. The results suggest the clinical possibility of this calcium phosphate cement, which could be used as a material for enhancing implant fixation.

Animals↗
PubMed1998

Fosfomycin, an antibiotic, possessed TGF-beta-like immunoregulatory activities.

The regulatory effects of fosfomycin (FOM) were correlated closely with the multifunction of TGF-beta in the modulation of immune responses in vivo and in vitro. LPS-induced polyclonal IgM and IgG antibody responses were depressed at 3 days after the initial culture and subsequently enhanced at day 10 by FOM or TGF-beta. Neither FOM nor TGF-beta inhibited LPS-induced IgA antibody responses, whereas dexamethasone (DX) reduced polyclonal IgM, IgG and IgA antibody responses wholly. The suppression of antibody responses and Mv1Lu cell proliferation induced by FOM or TGF-beta was partly overcome with soluble TFG-beta receptors (sRIII). Oral, i.v. and i.p. administration of FOM exhibited similar enhanced SRBC-specific antibody responses to that seen after oral administration of TGF-beta. The addition of FOM and latent TGF-beta inhibited the proliferation of Mv1Lu cells, but FOM did not lead to an increase in plasmin activities, which convert latent to active TGF-beta, and further the expression of TGF-beta receptors on the cell surface. In addition, FOM failed to enhance TGF-beta secretion. These findings suggest that immunomodulation of FOM results in increased sensitivity of cells to TGF-beta.

Adjuvants, Immunologic↗
PubMed1998

Study on the suitability of a rat model for tardive dyskinesia and the preventive effects of various drugs.

1. Male Sprague-Dawley rats (weighing 260-300 g) were administered 1.5 mg/kg of haloperidol (HPD) intraperitoneally once daily for 28 days to produce an animal model for tardive dyskinesia (TD). The daily administration of HPD significantly increased the frequency of involuntary orofacial movements (chewing movements, tongue protrusions and buccal tremors). 2. Its suitability as a model for TD was assessed in terms of the therapeutic effects of 6 drugs [trihexyphenodyl hydrochloride(THP), clonazepam(CZP), sodium valproate(VPA), alpha-tocopherol(Vit E), ritanserin(RS) and propranolol hydrochloride(PPL)]. These drugs were also used concomitantly with HPD to study their preventive effect. 3. As for the therapeutic effects of the drugs, both the single and the 14-day daily administrations of CZP as well as of VPA significantly suppressed the chewing movements. The results were mostly consistent with the effect of each drug on human TD, indicating this would be an excellent model for TD in terms of the drug responsiveness. 4. The concomitant administration of RS from the start of HPD administration significantly suppressed the appearance of chewing movements. The concomitant administration of Vit E for 42 days also suppressed chewing movements and buccal tremors. On the other hand, the concomitant administration of THP tended to aggravate these involuntary movements. 5. The fact that the therapeutic and preventive effects of the drugs on this model differed suggested that the development and recovery of the movements might also differ, at least in part.

Animals↗
PubMed1998

Effects of inhibitors for intracellular signal transduction systems on the inward current produced by GABA in a snail neuron.

1. An inward current (I[in]) was produced by gamma-aminobutyric acid (GABA) and muscimol, but not by baclofen, in an identifiable giant neuron type, v-LCDN (ventral-left cerebral distinct neuron), of an African giant snail (Achatina fulica Ferussac) under voltage clamp. 2. The pharmacological features of the excitatory GABA receptors in this Achatina neuron type, termed the Achatina muscimol II type GABA receptors, were mainly comparable to those of the mammalian GABA(C) receptors. 3. It was demonstrated in the present study that the following inhibitors for intracellular signal transduction systems showed no significant effect on the I(in) produced by GABA in this Achatina neuron type: H-7 [1-(5-isoquinolinyl sulfonyl)-2-methylpiperazine], an inhibitor of cyclic AMP-dependent protein kinase (PKA), cyclic GMP-dependent protein kinase (PKG) and protein kinase C (PKC); H-8 (N-[2-(methylamino)-ethyl]-5-isoquinolinesulfonamide), a PKA and PKG inhibitor; H-9 [N-(2-aminoethyl)-5-isoquinolinesulfonamide], a PKA inhibitor; staurosporine ((9alpha,10beta,11beta,13alpha)-(+)-2,3,10,11,12 ,13-hexahydro-10-methoxy-9-methyl-11-(methylamino)-9,13-epoxy-1H,9H-d iindolo[1,2,3-gh: 3',2',1'-1m]pyrrolo[3,4-j] [1,7]benzodiazonin-1-one), a PKA and PKC inhibitor; KT5823 ((8R,9S, 11S)-9-methoxy-9-methoxycarbonyl-2N,8-dimethyl-2,3,9,10-tetrahydro-8,11- epoxy-1H,8H,11H-2,7b,11a-triazadibenzo[a,g]cycloocta[c,d,e]- trinden-1-one), a PKG inhibitor; W-7 [N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide], a calmodulin inhibitor; ML-9 [1-(5-chloronaphthalene-1-sulfonyl-1H-hexahydro-1,4-diazepine hydrochloride], a myosin light-chain kinase inhibitor; genistein [5,7-dihydroxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one], a tyrosine protein kinase inhibitor; IBMX (3-isobutyl-1-methylxanthine), a cyclic nucleotide phosphodiesterase (PDE) inhibitor; fluphenazine nitrogen-mustard (2-chloroethyl)-4[3-(2-trifluoromethyl-10-phenothiazinyl)-propyl]p iperazine dihydrochloride), a calmodulin-dependent PDE inhibitor; calyculin A, a type 1 protein phosphatase inhibitor; and okadaic acid (9,10-deepithio-9,10-didehydroacanthifolicin), a type 1, 2A and 2B protein phosphatase inhibitor. 4. With these results, it was proposed that the excitatory Achatina muscimol II type GABA receptors in v-LCDN are not metabotropic but ionotropic.

Animals↗
PubMed1998

Properties of a peptide containing DL-lactide/glycolide copolymer nanospheres prepared by novel emulsion solvent diffusion methods.

Novel emulsion solvent diffusion methods in water or oil were developed to prepare the peptide (TRH and elcatonin)-loaded PLGA nanospheres, via the coprecipitation of drug and polymer in the emulsion droplets induced by the diffusion of solvent. The PLGA nanospheres prepared by the emulsion solvent diffusion method in water were unimodally dispersed particles with an average diameter of about 250 nm, whereas those prepared by the emulsion solvent diffusion method in oil and the phase separation method exhibited bimodal distribution with average diameter of about 700 and 800 nm, respectively. The content and recovery of the peptide and nanospheres prepared by the emulsion solvent diffusion method in oil were superior to those of nanospheres prepared using other methods. The drug release properties from nanospheres depended strongly on their preparation processes. The nanospheres prepared by the emulsion solvent diffusion method in oil, released the drug continuously over 14 days, the rate of which was determined by the diffusion of drug in the rigid matrix structure of the nanosphere. The drug release behavior of nanospheres prepared by the phase separation method exhibited a triphasic release pattern with an initial burst and an induction period followed by the diffusion of drug through the walls of the reservoir type nanospheres, which were produced via the phase separation of polymer deposited around the emulsion droplets of the drug.

Biocompatible Materials↗
PubMed1998

Synovial chondromatosis of the temporomandibular joint: the effect of interleukin-1 on loose-body-derived cells.

OBJECTIVE: The purpose of this study was to investigate the effect of interleukin-1 on cells from loose bodies of synovial chondromatosis of the temporomandibular joint. STUDY DESIGN: The cells were isolated from uncalcified loose bodies in a case of synovial chondromatosis of the temporomandibular joint and cultured in alpha-MEM medium containing 10% fetal bovine serum. The cells were treated with or without interleukin-1alpha and then stained with toluidine blue. Their conditioned media were analyzed with gelatin zymography to detect matrix-degrading proteinase(s). RESULTS: The cells from loose bodies produced toluidine-blue-stained matrix. When the cells were treated with 100 ng/ml of interleukin-1alpha for 3 days, toluidine-blue-stained matrix was strikingly reduced. Gelatin zymography revealed that interleukin-1alpha-treated cells released 62-kDa gelatinase. CONCLUSIONS: Interleukin-1alpha may lead loose-body-derived cells to degrade the cartilaginous matrix of loose bodies in synovial chondromatosis of the temporomandibular joint.

Animals↗
PubMed1998

A new powder design method to improve inhalation efficiency of pranlukast hydrate dry powder aerosols by surface modification with hydroxypropylmethylcellulose phthalate nanospheres.

PURPOSE: A new particle design method to improve the aerosolization properties of a dry powder inhalation system was developed using surface modification of hydrophobic drug powders (pranlukast hydrate) with ultrafine hydrophilic particles, hydroxypropylmethylcellulose phthalate (HPMCP) nanospheres. The mechanism of the improved inhalation properties of the surface-modified particles and their deposits on carrier particles (lactose) was clarified in vitro. METHODS: Drug particles were introduced to aqueous colloidal HPMCP dispersions prepared by emulsion-solvent diffusion techniques followed by freeze- or spray-drying of the resultant aqueous dispersions. The surface-modified powders obtained with HPMCP nanospheres and their mixture with lactose powders were aerosolized by Spinhaler and their mode of deposition in lung was evaluated in vitro using a twin impinger. To elucidate the inhalation mechanism of these surface modified particles, we measured their modified micromeritic properties, such as surface topography, specific surface area, dissolution rate, and dispersibility in air. RESULTS: Dramatically improved inhalation properties of the surface modified powder, i.e. a two-fold increase in emission and a three-fold increase in delivery to deep lung, were found in vitro compared with the original unmodified powder. Improved inhalation was also found with the surface-modified drug deposited on lactose particles. Those improvements were attributed to the increased surface roughness and hydrophilicity of the surface-modified particles, and the resultant increased dispersibility in air. CONCLUSIONS: Surface modification of hydrophobic drug particles with HPMCP nanospheres to improve hydrophilicity was extremely useful in increasing the inhalation efficiency of the drug itself and the drug deposited on carrier; this was attributed to increased dispersibility in air and emission from the device, for spray- and freeze-dried particles, respectively.

Administration, Inhalation↗
PubMed1998

Surface-modified antiasthmatic dry powder aerosols inhaled intratracheally reduce the pharmacologically effective dose.

PURPOSE: The aim of this study was to construct a reliable dry powder inhalation (DPI) testing system for use in guinea pigs. Using this system, we were able to demonstrate the superiority of pulmonary administration of hydrophilically surface-modified pranlukast hydrate powder (SM-DP) over IV and PO administration as reflected in improved pharmacological action. Our ultimate aim is the development of an ideal treatment system for bronchial asthma involving topical administration to the lung. METHODS: The reliability of the present DPI system was validated by continuously monitoring the concentration and particle size distribution of aerosols generated with an ambient particulate monitor and an Andersen air sampler, respectively. The pharmacological effect of SM-DP intratracheally administered to guinea pig was investigated by measuring the degree of bronchoconstriction and microvascular leakage induced by leukotriene D4. RESULTS: The mass concentration of aerosols generated by the DPI system was stable and the mass median aerodynamic diameter of aerosols insufflated from the respirator of the DPI system ranged from 1.4 to 1.7 microm, within respirable limits. Inhibition of bronchoconstriction and airway microvascular leakage induced by leukotriene D4 was achieved successfully with a dramatically lower dose of DP, or a further lower dose of SM-DP, comparable with that of the drug solution injected intravenously. The plasma pranlukast hydrate level with SM-DP at 50% inhibition of bronchoconstriction and airway microvascular leakage was reduced to 1/10 or less that following IV and PO administration. CONCLUSIONS: The hydrophilically surface-modified pranlukast hydrate powders were ideally aerosolized by the present DPI system, and were uniformly deposited in the lung lobes after inhalation. The pulmonary administration system with SM-DP is strongly recommended as an ideal system for the treatment of bronchial asthma in order to avoid systemic side-effects due to a dramatically reduced ED50, comparable with or lower than IV, and the low plasma concentration of drug, 1/12 or less than that following IV and PO administration.

Administration, Inhalation↗
PubMed1998

8-hydroxydeoxyguanosine in urine as an index of oxidative damage to DNA in the evaluation of atopic dermatitis.

8-hydroxydeoxyguanosine (8-OHdG) is one of the products which are excreted in urine as a result of oxidative damage to DNA. We investigated the feasibility of using 8-OHdG in urine as an index for oxidative damage to DNA in atopic dermatitis (AD). Seventeen patients with long-standing AD and 17 healthy volunteers were enrolled in this study. The severity of AD was evaluated by SCORAD index. Eosinophils, total IgE and lactate dehydrogenase-5 in peripheral blood were measured as clinical parameters for AD. A newly developed enzyme-linked immunosorbent assay method was used to measure urine 8-OHdG. The AD patients showed significantly higher levels (P < 0.0001) of 8-OHdG in their urine than corresponding controls. Urine 8-OHdG levels showed as strong a positive correlation as other haematological parameters did using the SCORAD index. Thus, we conclude that the urine 8-OHdG levels can also serve as a biochemical index of tissue damage and can act as a useful tool in the clinical evaluation of AD.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1998

Survival analytic approach to long-term prescription of benzodiazepine hypnotics.

Eight hundred and sixty-two patients who visited the department of neuropsychiatry and who were prescribed benzodiazepine (BZ) hypnotics were investigated to evaluate the actual state of their use, in terms of age, gender, diagnostic categories according to ICD-9, duration of prescription and dose equivalent to diazepam prescribed. The frequency of prescriptions in subjects were surveyed using Kaplan-Meier survival analysis at every 3 months. Mean survival time to discontinuation was 8.5 months. A total of 60% of the subjects did not receive BZ hypnotics at the end of the third month, but 20% remained to be prescribed after 1 year. Moreover, 7.9% of the subjects were prescribed BZ hypnotics even after 3 years. The results indicated that 20% of patients who had started prescriptions for BZ hypnotics had the potential to induce dependence. The following variables were found in the long-term prescription: male patients; aged patients over 60; and affective psychoses (which mainly consisted of depression) including neurotic depression, in the present study. A low dose was considered to be associated with an ability to be free from BZ hypnotics in an early period.

Adult↗
PubMed1998

A possible association between paternal longevity and major depression among elderly men.

Ancestral longevity is sometimes thought to contribute to psychosocial well-being in late life. The present paper aims to examine if parental longevity is associated with mental health among the elderly. The age at death of the parents was compared between 68 patients with major depression who were aged 65 or over and 40 subjects of the same age range without any history of psychiatric disorder. Cox regression revealed that the fathers of the elderly men with unipolar depression died at a significantly younger age than those of the control group. Several hypotheses are advanced to explain this unexpected and intriguing association.

Age Factors↗