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Biomedical subjects

T Takeuchi

Publications and source records attributed to T Takeuchi.

At least 91 records · Page 5Linked to original sources
PubMed2001

Orientation of bull sperms in static magnetic fields.

The orientation of bull sperm cells in static magnetic fields was investigated by microscopic observation. The bull sperm, which has a very flat head, was fixed and its motion was stopped by glutaraldehyde. It was oriented with the whole body and the flat head perpendicular to the direction of the magnetic field. The diamagnetic cell components, such as the cell membrane, the DNA in the head, and the microtubule in the tail, were thought to contribute to this orientation, because bull sperm does not have paramagnetic components. For quantitative measurement of the orientation, the intensity of transmitted light through glutaraldehyde-fixed bull sperm suspension in a photometric cell was determined. The intensity changed slightly in proportion to the mean degree of orientation of the sperms. It increased sigmoidally depending on the intensity of the magnetic field and reached 100% at just below 1 T. The magnetic orientation is very strong in comparison to that of erythrocytes or platelets. By studying the response of the bull sperm to the magnetic field, it will be possible to understand its microstructure in more detail.

Animals↗
PubMed2001

Levels of interleukin-18 and its binding inhibitors in the blood circulation of patients with adult-onset Still's disease.

OBJECTIVE: Interleukin-18 (IL-18) is a proinflammatory cytokine that is involved in immunologically mediated tissue damage, but its bioactivity is regulated in vivo by its soluble decoy receptor, IL-18 binding protein (IL-18BP). This study was undertaken to determine levels of IL-18 and IL-18 binding inhibition in the blood of patients with adult-onset Still's disease (ASD). METHODS: Serum concentrations of IL-18 in ASD patients were compared by enzyme-linked immunosorbent assay (ELISA) with those in patients with other systemic rheumatic diseases and healthy controls. The biologically active mature protein of IL-18 was detected by Western blot analysis with anti-IL-18 antibody and its induction of interferon-gamma (IFNgamma) secretion from IL-18-responding human myelomonocytic KG-1 cells. The inhibitory activity on IL-18 binding to its receptor was determined by 125I-IL-18 binding inhibition assay using the Chinese hamster ovary cell line transfected with a murine IL-18 receptor (CHO-K1/mIL-18R). RESULTS: Concentrations of serum IL-18 were extremely elevated in patients with active ASD compared with those in patients with rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, polymyositis/dermatomyositis, Sjogren's syndrome, or healthy individuals. Levels of IL-18 were found to correlate with serum ferritin values and disease severity in ASD. Western blot analysis revealed that serum samples from patients with active ASD contained an 18-kd polypeptide of IL-18, corresponding in size to the mature form. Accordingly, the samples were able to induce IFNgamma secretion from KG-1 cells, which was largely abolished by neutralizing anti-IL-18 antibody. However, the level of IL-18 bioactivity was more than 10-fold weaker than the concentration of IL-18 protein measured by ELISA. Serum samples from patients with active ASD showed an inhibitory effect on the binding of 125I-IL-18 to CHO-K1/mIL-18R cells, and this activity was associated with elevation of IL-18. CONCLUSION: These data indicate that systemic overproduction of IL-18 may be closely related to the pathogenesis of ASD, despite the restriction on its inflammatory activity by IL-18 binding inhibitors such as IL-18BP. The disease activity appears to be determined on the basis of the relative levels of IL-18 and its specific inhibitors.

Adult↗
PubMed2001

Nonlinear pharmacokinetics of TAK-044, a new endothelin antagonist, in rats.

The mechanism of the nonlinear pharmacokinetics of TAK-044 in rats was shown from in vivo and in vitro studies to be due to capacity-limited hepatic uptake. In the rats, which were given intravenous injections of (14)C-labeled TAK-044 ([(14)C]TAK-044) (1, 3, 10, 30 and 100 mg/kg), the AUC(inf) per unit dose of unchanged compound increased remarkably. An analysis model indicated that the CL(tot), V(1) and k(12) values of TAK-044 decreased significantly with increasing dose, whereas the k(el) values remained constant over the doses examined. The uptake clearance of [(14)C]TAK-044 by several tissues was investigated by an integration plot at doses from 0.3 to 60 mg/kg. This study showed that the liver played the principal role in the removal of TAK-044 from the plasma, while hepatic uptake was capacity-limited at doses greater than 30 mg/kg. The hepatic uptake study using rat hepatocytes indicated that a carrier-mediated transport system contributed to the hepatic uptake of TAK-044, and this system had high affinity (K(m,in vitro); 8.4 micromol/L) with low capacity (V(max,in vitro); 86.3 pmol/mg protein/min). These results show that the saturation of hepatic uptake by the carrier-mediated transport system could explain the nonlinear pharmacokinetics of TAK-044 in rats.

Animals↗
PubMed2001

Eosinophilic peroxidase deficiency: Identification of a point mutation (D648N) and prediction of structural changes.

ABSTRACT Hereditary eosinophil peroxidase (EPO; EC 1.11.1.7) deficiency is a rare abnormality without clinical symptoms characterized by decreased or absent peroxidase activity and decreased volume of the granule matrix in eosinophils. Nearly 100 cases have been reported, but a specific mutation has been reported in only one case. We report the genetic analysis of an EPO-deficient subject and his family. The case was found by automated blood analyzer. Sequencing of the entire coding region of the EPO gene disclosed a novel mutation, a 2060 G-A transition (g. 2060G>A) causing an amino acid change from aspartic acid to asparagine (D648N). Both the son and daughter of the propositus inherited the G-A transition, and in vitro expression experiments suggest this transition is responsible for the deficiency. We then analyzed the location of the affected amino acid within this molecule using a structural model of EPO based on myeloperoxidase (MPO). Asn648 is on the inside of the molecule; changing D to N would cause loss of the electrostatic interaction with Arg146 which is crucial for disulfide bonds of the light chain in the N terminus.

Amino Acid Substitution↗
PubMed2001

Production of germ-line chimeras in rainbow trout by blastomere transplantation.

We describe a technique for producing germ-line chimeric rainbow trout, Oncorhynchus mykiss, by microinjection of the isolated blastomeres. FITC-labeled donor cells and non-labeled recipient embryos at various developmental stages between the early blastula and early gastrula stages were used for cell transplantation. The chimera formation rate and the degree of donor cell distribution in recipient embryos were evaluated at both the late gastrula stage (5 days post fertilization (dpf)) and the 40-somite stage (10 dpf). Among the six combinations of developmental stages of donor and recipient embryos, the combination of midblastula (2.5 dpf) donor cells and early blastula (1.5 dpf) recipient embryos gave the highest chimera formation rate and the best distribution pattern of donor cells. Using this combination, chimeric rainbow trout were produced with donor blastomeres from dominant orange-colored mutant embryos and wild-type recipient embryos. Of the 238 chimeric embryos produced, 28 (12%) hatched normally and 14 of the 28 fry (50%) had donor-derived orange body color. To test for germ-line transmission of donor cells, gametes obtained from the matured chimeras were fertilized with gametes from wild-type fish. Of the 19 matured chimeras, 6 (32%) yielded donor-derived orange-colored progeny, in addition to wild-type siblings. The contribution rates of donor cells in the germ-line ranged from 0.3 to 14%. This technique for producing germ-line chimeras should be a powerful tool for cell-mediated gene transfer in rainbow trout. Especially, if body color mutants are used for either donor cells or the host embryos, it will be possible to easily concentrate F1 transgenic embryos derived from transplanted donor cells by body color screening. Mol. Reprod. Dev. 59: 380-389, 2001.

Animals↗
PubMed2001

The Dream Property Scale: an exploratory English version.

Our goal is to develop an English version of the Dream Property Scale (DPS-E) based on the original normed scale in Japan (DPS-J). Factor analyses extracted four factors (Emotionality, Rationality, Activity, and Impression) and its factor structure was apparently similar to the DPS-J. The DPS-E was also shown to be related to EEG power spectral values. These results indicate that the DPS-E may provide an exploratory basis for a reliable and valid tool for capturing and quantifying the properties of dream experiences that could reflect physiological activities without the intervention of experimenters. We suggest that the DPS-E will develop into a useful tool to help clarify dream production mechanisms by further investigation.

Affect↗
PubMed2001

Entamoeba invadens: enhancement of excystation and metacystic development by cytochalasin D.

Effects of three actin-modifying drugs, cytochalasin D, latrunculin A, and jasplakinolide, on the excystation and metacystic development in vitro of Entamoeba invadens were examined by transfer of the cysts to growth medium with the drugs. Cytochalasin D unexpectedly increased the number of metacystic amoebae of E. invadens strain IP-1 during incubation. Metacystic development, which was determined by the number of nuclei of metacystic amoebae, was faster in the culture with cytochalasin D than in the culture without the drug. These results suggest that cytochalasin D enhances the excystation and metacystic development. In contrast, latrunculin A and jasplakinolide inhibited these process. No excystation occurred in encystation medium even in the presence of cytochalasin D, suggesting that growth medium is essential for excystation. Excystation was further enhanced when the cysts were incubated with cytochalasin D before culture in growth medium with the drug. The enhancing effect of cytochalasin D on the excystation and metacystic development was abrogated by jasplakinolide. Thus, the results indicate that cytochalasin D, unlike latrunculin A and jasplakinolide, caused enhancement of the excystation and metacystic development of this parasite.

Animals↗
PubMed2001

Assessment of prognostic factors in follicular lymphoma patients.

Prognostic factors, including clinical, biological, and histological parameters, were assessed for 94 patients with follicular lymphomas at our institute. Follicular lymphomas constituted 7.7% (94/1208) of malignant lymphomas in this study. Eighteen patients were diagnosed with stage I follicular lymphoma, 20 with stage II, 23 with stage III, and 33 with stage IV. The cases of follicular lymphoma were subclassified as: follicular small cleaved cell lymphoma (FSC) in 20 cases, follicular mixed cell lymphoma (FMX) in 59 cases, and follicular large cell lymphoma (FLC) in 15 cases. The patients comprised 49 men and 45 women with a median age of 54 years (range, 25-84 years). The complete response rate was 76.5%, and the median survival time was 13 years. The expected 10-year overall survival and event-free survival rates were 61.9% and 38.2%, respectively. Univariate analysis identified the factors associated with poor survival as elevated serum lactate dehydrogenase (LDH) level (P < .0001), age of >60 (P < .0001), Ann Arbor stage III/IV (P < .01), and Eastern Cooperative Oncology Group performance status (PS) of 2 to 4 (P = .048). Multivariate analysis showed that LDH, age, and PS were independent predictors. After application of the International Prognostic Index (IPI), the 10-year survival rates for the low-risk, low-intermediate risk, high-intermediate risk and high-risk groups were 80.4%, 48.7%, 21.9%, and 0.0%, respectively. The differences among these groups were significant at P < .01. The IPI for aggressive non-Hodgkin's lymphoma was found to be applicable to survival prediction for Japanese follicular lymphoma patients.

Adult↗
PubMed2001

CD34+-selected autologous peripheral blood stem cell transplantation conditioned with total body irradiation for malignant lymphoma: increased risk of infectious complications.

Although high-dose chemotherapy with autologous peripheral blood stem cell transplantation (autoPBSCT) has been shown or confirmed to be an effective treatment for high-risk and relapsed non-Hodgkin's lymphoma (NHL), relapse after autoPBSCT remains a serious problem. In a clinical trial to overcome relapse, we adopted a treatment plan in which PBSCs purified in vitro to CD34+ cells to deplete tumor cells (CD34+ autoPBSCT), total body irradiation (TBI) of 1200 cGy, and melphalan, 180 mg/m2, were used as a preconditioning regimen. Eighteen patients with relapsed or high-risk NHL participated in the study. This study compared the incidence of complications following CD34+ autoPBSCT preconditioned with the TBI regimen (n = 10): the TBI group; CD34+ autoPBSCT with the non-TBI regimen (n = 8): the non-TBI group; and unselected autoPBSCT with the non-TBI regimen (n = 19): the unselected autoPBSCT control group. After day 30 posttransplantation, 6 of 10 patients treated with the TBI regimen developed 11 infectious complications in total, compared with only 1 of 8 patients treated with the non-TBI regimen and 4 of 19 patients given unselected autoPBSCT. Two fatal complications occurred in the TBI group, but none occurred in the other 2 groups. The CD4+ lymphocyte count at 1 month posttransplantation was significantly lower in the TBI group than in the unselected autoPBSCT group. These findings suggest that the addition of TBI to the preconditioning regimen for CD34+ autoPBSCT is associated with an increased incidence of severe infectious complications after transplantation.

Adult↗
PubMed2001

Primary natural killer cell lymphoma of the lacrimal sac.

Primary lymphoid tumors of the lacrimal sac are quite rare, and all reported cases are of B-cell tumors with good prognosis. To our knowledge, this is the first case of primary natural killer (NK) cell lymphoma of the lacrimal sac. A 55-year-old woman presented with a lacrimal sac tumor, and histological diagnosis of NK cell lymphoma was made. Although disease was initially localized to the right lacrimal sac, it invaded into the adjacent ethmoidal sinus before chemotherapy was initiated (clinical stage IIE). Epstein-Barr virus (EBV)-encoded small RNA (EBER) was detected in lymphoma cells by in situ hybridization. Systemic chemotherapy combined with intrathecal chemotherapy followed by local radiotherapy was performed, and the patient achieved complete remission. However, shortly after completion of chemoradiotherapy, the lymphoma relapsed with rapid systemic dissemination. The disease was refractory to chemotherapy, and the patient eventually succumbed due to sepsis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

T-cadherin (CDH13, H-cadherin) expression downregulated surfactant protein D in bronchioloalveolar cells.

T cadherin is a unique cadherin cell adhesion molecule that is anchored to the surface membrane through a glycosyl phosphatidyl inositol (GPI) moiety. In the present study, we postulated that T cadherin could regulate surfactant protein (SP)-D gene expression in human bronchioloalveolar type-II cells. We transfected A549 cells (human lung cancer cell line with alveolar type-II cell characteristics) with the T-cadherin expression vector. Both original and control plasmid-transfected A549 cells expressed SP-D; however, neither human nor murine T-cadherin-transfected A549 cells expressed SP-D mRNA. The downregulation of SP-D production in human T-cadherin-expressed A549 cells was also demonstrated using Western immunoblotting techniques. Control vector-transfected A549 cells showed a positive band of SP-D but not of T cadherin. In contrast, T-cadherin-transfected A549 cells, which expressed T-cadherin protein, did not produce SP-D. We further examined the relationship of T cadherin and SP-D expression in secondary pulmonary alveolar proteinosis associated with hematolymphoid malignancies. SP-D was detected in bronchioloalveolar type-II cells in alveolar proteinosis. However, little or no T-cadherin expression was detected in alveolar type-II cells in these patients. To our knowledge, this is the first report describing an effect of cadherin on SP production in bronchioloalveolar cells.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2001

Reduced human mismatch repair protein expression in the development of precancerous skin lesions to squamous cell carcinoma.

Loss of human mismatch repair (hMSH2) gene function has been linked to hereditary non-polyposis colorectal cancer (HNPCC), Muir-Torre syndrome (MTS), and sporadic cancers, excluding skin cancers unrelated to MTS. We immunohistochemically examined 125 squamous cell carcinomas (SCCs) using a monoclonal antibody to the hMSH2 protein and compared the results with those for 106 precursor lesions of SCC, consisting of actinic keratosis (AK), Bowenoid type of actinic keratosis (BAK), and Bowen's disease (BOD). In contrast to the homogeneous immunoreactivity of proliferating cells composed of AK, BAK, and BOD, heterogeneous and diminished immunostaining to hMSH2 was observed in tumor cells of SCCs examined. In addition, two SCCs (2 of 125; 1.6%) at multiple loci exhibited a complete lack of immunoreaction to hMSH2. Immunohistochemical staining of hMSH2 was semiquantitatively scored as 0 (0% of total cells examined), 1 (less than 10%), 2 (10-50%), or 3 (more than 50%). Percentage preservation of and average score for hMSH2 expression in normal, AK, BAK, BOD, and SCC were 56% and 2.06, 100% and 2.80, 94% and 2.88, 83% and 2.78, 63% and 2.36, respectively. The percentage preservation of and average scores for hMSH2 in AK, BAK, and BOD were significantly higher than those in presumably normal skin (P<0.01). There were no significant differences in the percentage preservation of and average scores for hMSH2 between presumably normal skin and SCC. The score for hMSH2 expression was significantly correlated with score for sun exposure in presumably normal skin of each lesion (R=0.70). These findings for hMSH2 expression in precursor lesions and SCC suggest that promotion or activation of hMSH2 expression may be induced by the increased DNA damage caused by sun exposure and that diminished expression of it might occur according to the transformation from precancerous lesions to SCC.

Adult↗
PubMed2001

Inhibition of encystation of Entamoeba invadens by wortmannin.

Using an axenic encystation system in vitro, we examined the effect of wortmannin, a potent inhibitor of phosphatidylinositol 3-kinase (PI 3-kinase), which is a signaling molecule responsible for numerous cellular responses, on the encystation of Entamoeba invadens. Wortmannin inhibited both encystation and growth of E. invadens strain IP-1 in a dose-dependent manner, the former being more resistant to the drug than the latter. There was little decrease in the number of trophozoites after 3 days of culture in encystation medium containing wortmannin; and the cells remained motile, suggesting that the inhibitory effect of the drug on encystation was not due to its toxic effect on trophozoites. The addition of wortmannin after the induction of encystation was also inhibitory for encystation. Trophozoites incubated for 1 day in encystation medium with wortmannin did not encyst after removal of the drug, suggesting that the drug effect was not reversible in encystation medium. In contrast, trophozoites cultured in growth medium with wortmannin did encyst after their transfer to encystation medium without the drug. Encystation with wortmannin was more strongly inhibited among trophozoites grown in the presence of the drug than among those grown in the absence of the drug. The process of cyst maturation was slightly affected by wortmannin. These results suggest a possible role for PI 3-kinase in the signaling involved in the encystation of E. invadens.

Androstadienes↗
PubMed2001

Effect of calcium antagonists, calcium channel blockers and calmodulin inhibitors on the growth and encystation of Entamoeba histolytica and E. invadens.

The effects of calcium antagonists, calcium channel blockers, and calmodulin inhibitors on the growth of Entamoeba histolytica and the growth and encystation of Entamoeba invadens were examined. Calcium chelators ethyleneglycol bis (beta-aminoethyl ether)-N,N'-tetraacetate (EGTA) and ethylene-diaminetetraacetate (EDTA) inhibited the growth of both Entamoeba and also the encystation of E. invadens in a dose-dependent manner, with EDTA being more effective than EGTA. A putative antagonist of intracellular calcium flux, 8-(N,N-diethylamino) octyl-3,4,5-trimethoxybenzoate (TMB-8) also inhibited both growth and encystation, with the E. histolytica being more sensitive than E. invadens, and with the growth of E. invadens being more sensitive than encystation. The slow Na+-Ca2+ channel blockers bepridil and verapamil inhibited both growth and encystation. Bepridil was more effective than verapamil. The calmodulin (CaM) inhibitors, W-7 (N-(6-aminohexyl)-chloro-1-naphtalene sulphonamide) and trifluoperazine (TFP), were also inhibitory for both the growth and encystation; TFP was more effective than W-7, and encystation was more sensitive than growth in E. invadens. These results indicate that extracellular calcium ions, amebic intracellular calcium flux, calcium channels, and a CaM-dependent process contribute to the growth and encystation of Entamoeba.

Animals↗
PubMed2001

Gastrointestinal stromal tumor of the stomach: report of a case.

We report herein the case of a 70-year-old woman found to have a gastrointestinal stromal tumor (GIST) of the stomach. Preoperative X-ray and endoscopic examination revealed a hemispheric submucosal tumor with central depression in the anterior wall of the gastric fornix. The tumor, which was 3 cm in diameter, was resected by a laparoscopy-assisted procedure. Histologic examination revealed that it was composed of spindle-shaped cells with elongated nuclei, and few mitoses. Most of the tumor cells showed immunoreactivity for vimentin and CD34, but not for alpha-smooth muscle actin, desmin, or S-100 protein. The PCNA index was 40.5%. Thus, the GIST did not show differentiation toward smooth muscle or neural cells. A gastrectomy was not performed because the small size of the tumor, and the paucity of the mitoses indicated that it was benign. Nevertheless, careful and long-term follow-up is needed to monitor for signs of possible local recurrence or distant metastases.

Aged↗
PubMed2001

Expression of SMARCF1, a truncated form of SWI1, in neuroblastoma.

Previously we cloned and mapped a B120 gene to human chromosome 1p35-36.1 where possible suppressor genes for various neuroendocrine tumors including neuroblastoma have been mapped. Very recently, B120 was identified as a truncated form of p270, a putative human counterpart of SWI1. In the present study, expression of the B120 gene product was immunohistochemically investigated in 23 neuroblastomas. We also examined B120 expression in neural stem cells in developing brain and intact adrenal medulla. Four of 23 neuroblastomas strongly expressed B120 gene product in both cytoplasm and nucleus. The other neuroblastomas expressed B120 gene product in the nucleus; however, the intensity of staining was much weaker and equivalent to that in developing human brain stem cells in the subventricular region. B120 gene product was less strongly expressed in intact adrenal medulla. Subsequently, we performed loss of heterozygosity studies on 19 neuroblastomas using the polymorphic markers D1S195 and D1S511 located near the B120 gene. Loss of heterozygosity was observed in three of 19 tumors that abundantly expressed B120 protein. Furthermore, neuroblastoma cells were transfected with B120 expression vector. These transfected neuroblastoma cells adhered to each other and aggregated. Differential display experiments followed by reverse transcriptase-polymerase chain reaction and Northern blot analysis were performed and three molecules with altered expression in B120-transfected neuroblastoma cells were identified. One of three genes seemed to be a proliferation-related and cell cycle-related nucleolar protein, p120, encoding gene. We further characterized the genomic structure of B120. B120 appeared to be encoded by 17 exons in more than 20-kbp genomic DNA. The present findings contribute to understanding of the B120 gene, a truncated form of human SWII1, an approved term for which is SMARCF1, in normal cells and neuroblastomas.

Base Sequence↗