Biomedical subjects

T Takagi

Publications and source records attributed to T Takagi.

At least 199 records · Page 11Linked to original sources

PubMed1999

[Study of optimal CHOP dose ranges for elderly patients with non-Hodgkin's lymphoma].

Two groups of intermediate-to high-grade non-Hodgkin's lymphoma patients aged 65 years and over were enrolled in a dose-range study of CHOP therapy utilizing 5 doses (1/2, 7/12, 2/3, 5/6, full CHOP): 11 patients 65-79 years of age (group A) and 9 patients 80 years or older (group B). The patients were enrolled consecutively; the study was designed so that if 3 patients completed 3 cycles of CHOP on schedule without major problems, the next highest dose was administered. If 2 patients experienced any major problems during 6 cycles at a given dose, treatment was discontinued and the dose prior to that particular dose was regarded as the optimal dose. The 6 treatment cycles were completed by 3 of 3 (2/3 CHOP), 3 of 4 (5/6 CHOP), and 1 of 4 (full CHOP) group A patients; and by 3 of 3 (1/2 CHOP), 2 of 3 (7/12 CHOP) and 1 of 3 (2/3 CHOP) group B patients. The results indicated that the optimal doses for group A and B were five-sixths and seven-twelfths of the standard CHOP dose, respectively.

Aged↗

PubMed1999

[Effects of imaging parameters on automated cardiac flow measurement using color Doppler echocardiography].

The color Doppler echocardiographic technique has been developed for automated cardiac flow measurement (ACM). This study evaluated the effect of imaging parameters on stroke volume measurement. Cardiac output derived from the ACM method was compared with that obtained from pulsed wave Doppler in 36 patients (26 men and 10 women, mean age 54 +/- 8 years) in whom clear two-dimensional and color Doppler images of the left ventricular outflow tract were obtained. The effects of frame rate, color gain and moving target indicator (MTI) filter on cardiac output were evaluated in 13 patients (8 men and 5 women, mean age 49 +/- 6 years). Using ACM at a frame rate of 30 Hz, optimal color gain setting and high-frequency MTI filter (cutoff frequency: 915 Hz), there was an excellent correlation in cardiac output between the ACM and pulsed wave Doppler methods (stroke volume: r = 0.91, SEE = 0.32 l/min). Using ACM at a frame rate of 30, 22 and 15 Hz, the differences in stroke volume were 4.4%, 5.2% and 8.6%, respectively. When color gain was reduced, left ventricular stroke volume reduction was 12.1% (-2 dB), 18.9% (-4 dB). In contrast, there was no significant change in stroke volume measurement when color gain was increased. There was a significant decrease in stroke volume using the low-frequency MTI filter [cutoff frequency: 467 Hz (-35.6%)] and medium-frequency MTI filter [cutoff frequency: 703 Hz (-13.4%)]. Color Doppler imaging parameters are extremely important for automated assessment of cardiac output.

Automation↗

PubMed1999

[Improvement of quality of life (QOL) and life prolongation by CPT-11 + adriamycin (ADM) therapy: report of 4 cases of non-Hodgkin's lymphoma refractory to conventional chemotherapies].

CPT-11 + ADM therapy (CPT-11 40 mg/body x 2 days; Day 1 & 2, combined with ADM 20 to 60 mg/body x 1 day; Day 3) was given to four patients with relapsed and advanced non-Hodgkin's lymphoma, which was refractory to conventional chemotherapies. The symptoms of the patients at the beginning of CPT-11 + ADM therapy were fever (in two cases), dyspnea due to pleural effusion (in two), severe backache (in one), and jaundice with splenomegaly (in one). Their Karnofsky performance scales were 20 or 30%. Soon after the initiation of CPT-11 + ADM therapy, their clinical conditions improved dramatically, and they obtained a partial remission lasting 3.5 to 9 months. During the period of controlling lymphomas by this therapy, all patients had some time at home for 2 to 8 months. The adverse effects were vomiting, diarrhea, neutropenia and thrombocytopenia, but no lethal infection or hemorrhage was seen. We conclude that CPT-11 + ADM therapy is very useful for improvement of QOL and life prolongation of patients with non-Hodgkin's lymphoma, which is refractory to conventional chemotherapies and is even disseminated.

Adult↗

PubMed1999

Measurement of serum leptin in patients with chronic renal failure on hemodialysis.

BACKGROUND: Leptin, the product of the obese gene, is produced exclusively in fat cells. SUBJECTS, MATERIALS AND METHODS: To evaluate the clinical significance of measuring serum leptin in 56 patients with chronic renal failure on hemodialysis (HD), we measured leptin levels using radioimmunoassay in 34 normal volunteers and in 56 patients on HD. RESULTS: Normal serum leptin averaged 5.7 +/- 0.7 (mean +/- SEM) ng/ml, which correlated significantly (p < 0.001) with the body fat percentage as measured by bioelectrical impedance analysis. Serum leptin in HD patients ranged from 1.3 to 142 ng/ml. The mean serum leptin analyzed after the logarithmic conversion was 5.6 ng/ml, which was not significantly different from the normal control value, although the body fat percentage was significantly lower than normal volunteers. There was a significant (p < 0.01) positive correlation between body fat percentage and serum leptin in both normal controls and HD patients. The slope of the regression curve was steeper in HD patients than in normal controls. CONCLUSION: (1) serum leptin levels to body fat mass are significantly higher in HD patients than controls; (2) the variability is much wider in HD patients; and (3) a significant relation exists between percent body fat and log serum leptin, the relation being steeper in HD patients than in controls.

Adipose Tissue↗

PubMed1999

[Evaluation of chemotherapy with docetaxel and cisplatin in advanced non-small cell lung cancer].

Clinical study has been conducted to evaluate the efficacy of chemotherapy with docetaxel and cisplatin in six patients with advanced non-small cell lung cancer. Treatment schedule consisted of docetaxel 60 mg/m2 and cisplatin 80 mg/m2 on day 1 and repeated every 4 weeks. Eligible patients had histologically proven locally advanced or metastatic non-small cell lung cancer, PS < or = 2, age < or = 74, normal hematological, hepatic and renal functions and informed consent in writing. Six patients have been included; all were males, median age 64 (range 47-74), histology; adenocarcinoma 4, squamous cell carcinoma 2, stage III B 4, stage IV 2. Among these 6 patients, 3 PR (50%) were observed. Neutropenia was the most common adverse event (83%). The lowest granulocyte counts were most frequently seen on day 9.4 (range: 6-14). Non hematologic adverse events included alopecia (6 cases), general fatigue (5 cases), anorexia (5 cases) and emesis (3 cases). These events were recovered rapidly with no therapy. The results suggest that combination chemotherapy of docetaxel and cisplatin will be effective and safe under careful observation.

Adenocarcinoma↗

PubMed1999

[Refractory multiple myeloma preceded by extramedullary plasmacytoma of lymph node--a case report and review of the literature].

It has been reported that extramedullary plasmacytoma (EMP) tends to be characterized by an indolent clinical course and lower incidence of progression to multiple myeloma. Primary plasmacytoma of lymph nodes is extremely rare and details of its clinical picture remain unclarified. We recently encountered an unusual case of EMP of lymph nodes that progressed to refractory multiple myeloma only 18 months later. A 74-year-old woman was admitted to our hospital because of a painless swelling in the right inguinal region. A tumor was removed surgically, and a histological diagnosis of EMP of the lymph nodes was made. Bence Jones protein (BJP) was detected in the urine, but there was no other evidence of systemic myelomatosis. The patient received local irradiation, which resulted in the elimination of BJP. Eighteen months later, however, a tumor developed in her right stemo-clavicular joint. A bone survey revealed multiple osteolytic lesions, and many atypical plasma cells were observed in the bone marrow, indicating multiple myeloma. The patient deteriorated despite several regimens of combination chemotherapy, and died four and a half years after the initial diagnosis of EMP.

Aged↗

PubMed1999

Effects of hyaluronate on CD44 expression of infiltrating cells in exudate of rat air pouch, induced by sensitization with lipopolysaccharide.

OBJECTIVE: To investigate the effects of hyaluronate (HA) on CD44 expression of infiltrating cells in vivo. METHODS: Intra-air pouch injection of 10 microg lipopolysaccharide (LPS) with 0.4, 4.0, or 40 mg HA, 40 mg carboxymethylcellulose (CMC), or saline was performed on rats immunized with LPS. The percentage of CD44+ cells in the exudate of the air pouch was measured by flow cytometry, and the concentrations of interleukin 1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) in the air pouch exudate were measured by ELISA. IL-1beta and TNF-alpha in the air pouch lining layer were stained by immunohistochemistry. RESULTS: The percentage of CD44+ cells in air pouch exudate was greater in the presence of HA, with a dose dependent increase (0.4 mg, 9.4+/-2.6%, n = 4; 4.0 mg, 13.8+/-2.9%, n = 4; 40 mg, 24.9+/-6.3%, n = 3; p < 0.05), while it was 4.9+/-1.2% (n = 4) in the presence of 40 mg CMC. The concentration of IL-1beta was lower in the presence of 40 mg HA (251.0+/-61.4 pg/ml, n = 4) or 40 mg CMC (168.2+/-43.5 pg/ml, n = 4; p < 0.05) than in saline (403.0+/-60.5 pg/ml, n = 4). The concentration of TNF-alpha was lower in the presence of 40 mg HA (14.0+/-6.7 pg/ml, n = 4) or 40 mg CMC (7.04+/-7.0 pg/ml, n = 4) than in saline (38.2+/-12.2 pg/ml, n = 4). Extensively stained lining cells in superficial layer of the air pouch with IL-1beta and TNF-alpha were observed in rats inoculated with 0.4 mg HA. CONCLUSION: These findings suggest that HA might affect the inflammatory process through modifying CD44 expression on infiltrating cells in air pouch exudate.

Adjuvants, Immunologic↗

PubMed1999

Antioxidative action of flavonoids, quercetin and catechin, mediated by the activation of glutathione peroxidase.

Antioxidative action of flavonoids have been attracted attention of many investigators and a good deal of studies on it were reported. While their interests were mostly centered to the direct scavenging action of flavonoids against free radicals and active oxygen species, we expected that the interaction of flavonoids and intracellularly occurring antioxidative agents such as glutathione peroxidase (GSH-PO) could synergistically enhance their antioxidative activities. For this purpose, cultured rat hepatocytes (BL-9), which are highly expressing GSH-PO, were employed. One group of the cells were cultured with Se deficient media (Se(-) cells) to diminish the activity and the expression of GSH-PO protein and mRNA, and the other group was cultured with Se supplemented media (Se(+) cells). The oxidative cell damage was induced by the addition of H2O2 and two representative antioxidative flavonoids, quercetin and catechin, were added to the media to test their cytoprotective action. In Se(+) cells, the remarkable cytoprotective activity of those flavonoids were confirmed, whereas none of such activity was evidenced in Se(-) cells. It was proved that the intracellular antioxidative function of flavonoids requires the interaction with GSH-PO, at least in the cells expressing the enzyme. Interestingly, the flavonoid activated GSH-PO clearly, and its mechanism is discussed.

Animals↗

PubMed1999

[Measurement of left ventricular filling by automated contour tracking method in echocardiography: comparison with radionuclide ventriculography].

Recent development of an automated contour tracking (ACT) method using the energy minimization principle provides automated edge detection and tracking of the endocardial boundary of the left ventricle, without tracing a region of interest. This study determined whether left ventricular filling indexes obtained from the ACT method provide a reliable estimate of left ventricular diastolic filling. Fourteen patients were examined by the ACT method and equilibrium radionuclide ventriculography. The volume-time wave form for ACT measurements was obtained from the 4-chamber views. Peak filling rate and time to peak filling rate measured by the ACT method were compared with those determined by radionuclide ventriculography. Peak filling rate and time to peak filling rate by the ACT method were closely correlated with those determined by radionuclide ventriculography (peak filling rate: r = 0.88, y = 0.71x + 0.36, SEE = 0.54 ml/end-diastolic volume/sec, time to peak filling rate: r = 0.89, y = 0.72x + 30.0, SEE = 0.02 msec, respectively) The ACT method is useful for the assessment of left ventricular diastolic filling.

Aged↗

PubMed1999

Characterization of a novel variant (S145C/L311V) of 3alpha-hydroxysteroid/dihydrodiol dehydrogenase in human liver.

Human liver 3alpha-hydroxysteroid/dihydrodiol dehydrogenase (DD) is involved in the metabolism of steroid hormones and polycyclic aromatic hydrocarbons, and is also responsible for the reduction of ketone-containing drugs. To account for the interindividual difference in the activity, we isolated and characterized clones for the human liver enzymes. The sequence of the cDNA clone coding for the variant differed from that coding for the wild-type DD by two nucleotides (substitutions of C with G at positions 434 and 931) which caused two amino acid replacements, Ser145 to Cys (S145C) and Leu311 to Val (L311V). The heterologous expression of the variant mRNA was confirmed in four of 31 liver samples from Japanese by an allele-specific polymerase chain reaction. The effects of the mutations on the catalytic properties were examined with the recombinant enzymes expressed in Escherichia coli. The introduction of S145C/L311V double mutations resulted in three- to five-fold decreased activities for xenobiotic and steroidal substrates, whereas no significant change was observed by an introduction of the S145C mutation alone. The results substantiate the existence of polymorphic forms for human liver DD, and also suggest the importance of the residue at position 311 for substrate binding to the enzyme.

Base Sequence↗

PubMed1998

Evidence that P-TEFb alleviates the negative effect of DSIF on RNA polymerase II-dependent transcription in vitro.

Recently, a positive and a negative elongation factor, implicated in 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) inhibition of transcription elongation, has been identified. P-TEFb is a positive transcription elongation factor and the DRB-sensitive kinase that phosphorylates the C-terminal domain (CTD) of the largest subunit of RNA polymerase II (Pol II). PITALRE, a member of the Cdc2 family of protein kinases, is the catalytic subunit of P-TEFb. DSIF is a human homolog of the yeast Spt4-Spt5 complex and renders elongation of transcription sensitive to DRB. DRB sensitivity-inducing factor (DSIF) binds to RNA Pol II and may directly regulate elongation. Here we show a functional interaction between P-TEFb and DSIF. The reduction of P-TEFb activity induced by either DRB, antibody against PITALRE, or immunodepletion resulted in a negative effect of DSIF on transcription. DSIF acts at an early phase of elongation, and the prior action of P-TEFb makes transcription resistant to DSIF. The state of phosphorylation of CTD determines the DSIF-RNA Pol II interaction, and may provide a direct link between P-TEFb and DSIF. Taken together, this study reveals a molecular basis for DRB action and suggests that P-TEFb stimulates elongation by alleviating the negative action of DSIF.

Cyclin-Dependent Kinase 9↗

PubMed1998

Allosteric interactions between capping enzyme subunits and the RNA polymerase II carboxy-terminal domain.

mRNA capping is a cotranscriptional event mediated by the association of capping enzyme with the phosphorylated carboxy-terminal domain (CTD) of RNA polymerase II. In the yeast Saccharomyces cerevisiae, capping enzyme is composed of two subunits, the mRNA 5'-triphosphatase (Cet1) and the mRNA guanylyltransferase (Ceg1). Here we map interactions between Ceg1, Cet1, and the CTD. Although the guanylyltransferase subunit can bind alone to the CTD, it cannot be guanylylated unless the triphosphatase subunit is also present. Therefore, the yeast mRNA guanylyltransferase is regulated by allosteric interactions with both the triphosphatase and CTD.

Acid Anhydride Hydrolases↗

PubMed1998

Characterization of a heat modifiable protein, Escherichia coli outer membrane protein OmpA in binary surfactant system of sodium dodecyl sulfate and octylglucoside.

A membrane protein, OmpA of Escherichia coli, in the process of refolding from its heat-modified form in the presence of sodium dodecyl sulfate (SDS) to its non-heated one by the addition of systematic amounts of octylglucoside (OG) was characterized by means of dynamic light scattering and the size exclusion chromatography combined with low angle laser light scattering photometry. Upon heating in the presence of SDS only, the amount of SDS bound to OmpA was increased from 1.8 to 2.3 g/g of protein and its hydrodynamic radius increased from 3.7 to 4.7 nm. On the addition of OG, the once denatured OmpA regained its original size above the weight fraction of OG in the total amount of surfactants, 0.8. During the process, the hydrodynamic radius was observed to decrease cooperatively at the weight fraction of 0.6, while no change took place in the molar mass of the protein. The refractive index increment of OmpA reflecting the amount of surfactant binding also regained the value before the heating in parallel with the change of size. Examination of the amount of surfactants bound to the membrane protein according to known properties of the binary surfactant micellar system of the surfactants showed that SDS was principally responsible for the denaturing phenomena of OmpA.

Bacterial Outer Membrane Proteins↗

PubMed1998

The influence of DNA ploidy of a human tumor cell line on the frequencies of micronuclei or chromosome aberrations after irradiation.

To develop methods for assessing the intrinsic cellular radiosensitivity, it is important to evaluate the relationship between DNA ploidy of cells and frequencies of micronuclei (MN) or chromosome aberrations after irradiation. From the original human fibrosarcoma cell line HT-1080, we isolated two clones which have different chromosome ploidy: clone 5 is pseudodiploid and clone 1 is heteroploid. We examined the radiosensitivity of the two clones using a clonogenic cell survival assay and a cytokinesis-block MN assay, and by scoring chromosome aberrations using the premature chromosome condensation (PCC) method combined with a fluorescence in situ hybridization (FISH) procedure immediately and at 24 h after irradiation. The MN frequency increased according to the irradiation dose in both clones. The MN frequency of clone 1 was significantly higher than that of clone 5 regardless of whether the assay was performed immediately or 24 h after irradiation. However, when the numbers of MN were normalized by the DNA index of each clone, a significant difference in the frequency of MN was not observed. In the PCC and FISH studies, there was a linear relationship between the radiation dose and the initial breaks of chromosome 4, but the breaks of clone 1 were much more frequent than those of clone 5. Twenty-four h after irradiation, the chromosome 4 breaks of clone 1 were observed much more frequently than those of clone 5 at the same radiation dose. When the numbers of chromosome 4 breaks were normalized by the number of chromosome 4 in each clone without radiation, no such difference in the number of breaks was observed. These findings demonstrated that the DNA content or chromosome ploidy influenced the induction of the MN or chromosome aberrations in HT-1080 cells after irradiation.

Cell Survival↗

PubMed1998

Acetonitrile-protein interactions: amino acid solubility and preferential solvation.

The solubility of amino acids and the preferential solvent interaction of hen-egg lysozyme in acetonitrile (AN)-water mixtures (<60 w/v% AN) were investigated by means of densimetric and refractometric methods at 25 degreesC. The free energy of transfer from water to aqueous AN was negative for most nonpolar side-chains of amino acids and positive for the peptide group, the extent being comparable to those for methanol and ethanol systems. Addition of AN to an aqueous solvent was thus suggested to weaken the hydrophobic interaction and to enhance the peptide-peptide hydrogen bond therein leading to the denaturation of proteins. A parallel examination by circular dichroism confirmed that the conformation of lysozyme (pH 3) remains native in aqueous AN up to 40% but changes to the helix-rich form at higher AN concentrations. At all solvent compositions up to 50% AN (pH 3), however, lysozyme was preferentially hydrated probably due to a local salting-out of the AN molecules from the charges on the protein surface, indicating the increase of the chemical potential of the protein. These results are discussed in relation to the role of AN as an eluting organic solvent in reverse-phase chromatography.

Acetonitriles↗

PubMed1998

N-terminal myosin-binding fragment of talin.

Talin, an actin-binding protein from smooth muscle, is shown to bind to myosin in such a way that it stimulates the ATPase activity of myosin irrespective of the phosphorylation state of myosin. The binding site is shown to be localized at the N-terminal, 47 KDa fragment. The position of the actin-binding site at the C terminal suggests that talin may work as a crosslinker between myosin and actin.

Actins↗

PubMed1998

A protein tyrosine phosphatase-like protein from baculovirus has RNA 5'-triphosphatase and diphosphatase activities.

The superfamily of protein tyrosine phosphatases (PTPs) includes at least one enzyme with an RNA substrate. We recently showed that the RNA triphosphatase domain of the Caenorhabditis elegans mRNA capping enzyme is related to the PTP enzyme family by sequence similarity and mechanism. The PTP most similar in sequence to the capping enzyme triphosphatase is BVP, a dual-specificity PTP encoded by the Autographa californica nuclear polyhedrosis virus. Although BVP previously has been shown to have modest tyrosine and serine/threonine phosphatase activity, we find that it is much more potent as an RNA 5'-phosphatase. BVP sequentially removes gamma and beta phosphates from the 5' end of triphosphate-terminated RNA, leaving a 5'-monophosphate end. The activity was specific for polynucleotides; nucleotide triphosphates were not hydrolyzed. A mutant protein in which the active site cysteine was replaced with serine was inactive. Three other dual-specificity PTPs (VH1, VHR, and Cdc14) did not exhibit detectable RNA phosphatase activity. Therefore, capping enzyme and BVP are members of a distinct PTP-like subfamily that can remove phosphates from RNA.

Acid Anhydride Hydrolases↗

PubMed1998

Casein kinase II interacts with the bZIP domains of several transcription factors.

Casein kinase II (CKII) is thought to regulate a broad range of transcription factors, but its mode of action is not well characterized. We previously showed that CKII is co-purified with the ATF family of transcription factors using DNA-affinity latex beads. Here we report a functional and physical interaction between CKII and transcription factors. We demonstrate that CKII binds through its catalytic alpha and alpha' subunits to the basic leucine zipper (bZIP) DNA-binding domains of many transcription factors, including ATF1. Kinetic analysis using a surface plasmon resonance sensor suggests that CKII loosely associates with ATF1 in vivo . Deletion of the bZIP domain of ATF1 markedly reduces its phosphorylation by CKII, suggesting that the bZIP recruits CKII to the vicinity of the target site. ATF1-CKII complex is also formed on DNA. Using CKIIalpha fusedto a heterologous DNA-binding domain, we also demonstrate that CKII, when bound to DNA, efficiently phosphorylates its substrate, which is bound to the same DNA molecule. Taken together, CKII may regulate transcription (and possibly other events) by phosphorylating proteins on DNA.

Activating Transcription Factor 1↗