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T Takagi

Publications and source records attributed to T Takagi.

At least 721 records · Page 40Linked to original sources
PubMed1987

Ethanol-metabolizing pathways in deermice. Estimation of flux calculated from isotope effects.

The apparent deuterium isotope effects on Vmax/Km (D(V/K] of ethanol oxidation in two deermouse strains (one having and one lacking hepatic alcohol dehydrogenase (ADH] were used to calculate flux through the ADH, microsomal ethanol-oxidizing system (MEOS), and catalase pathways. In vitro, D(V/K) values were 3.22 for ADH, 1.13 for MEOS, and 1.83 for catalase under physiological conditions of pH, temperature, and ionic strength. In vivo, in deermice lacking ADH (ADH-), D(V/K) was 1.20 +/- 0.09 (mean +/- S.E.) at 7.0 +/- 0.5 mM blood ethanol and 1.08 +/- 0.10 at 57.8 +/- 10.2 mM blood ethanol, consistent with ethanol oxidation principally by MEOS. Pretreatment of ADH- animals with the catalase inhibitor 3-amino-1,2,4-triazole did not significantly change D(V/K). ADH+ deermice exhibited D(V/K) values of 1.87 +/- 0.06 (untreated), 1.71 +/- 0.13 (pretreated with 3-amino-1,2,4-triazole), and 1.24 +/- 0.13 (after the ADH inhibitor, 4-methylpyrazole) at 5-7 mM blood ethanol levels. At elevated blood ethanol concentrations (58.1 +/- 2.4 mM), a D(V/K) of 1.37 +/- 0.21 was measured in the ADH+ strain. For measured D(V/K) values to accurately reflect pathway contributions, initial reaction conditions are essential. These were shown to exist by the following criteria: negligible fractional conversion of substrate to product and no measurable back reaction in deermice having a reversible enzyme (ADH). Thus, calculations from D(V/K) indicate that, even when ADH is present, non-ADH pathways (mostly MEOS) participate significantly in ethanol metabolism at all concentrations tested and play a major role at high levels.

Acetates↗
PubMed1987

Calcium-binding proteins in rat skin.

Skin Ca2+-binding protein (SCaBP) was reported to be distinct from the Ca2+-binding parvalbumin (PV), however, more recently its amino acid sequence was shown to be identical to PV. We purified a protein (Mr 12,000; pI4.5) from isolated epidermis (free of other cell layers) of adult rats and whole skin (containing no PV) of newborn rats. This protein is referred to as epidermal protein (EP-12), distinct from PV in its hydrophobicity, amino acid composition and immunological properties. Previously isolated SCaBP was shown to be a mixture of EP-12 and PV. The localization and possible functions of EP-12 and of PV in skin of adult and newborn rat are discussed.

Amino Acids↗
PubMed1987

Characteristics of primary cultured neurons from embryonic mutant El mouse cerebral cortex.

To elucidate the differences between neurons of epileptogenic animals and those of normal animals, cellular characteristics of neurons of mutant strain El mice which are highly susceptible to seizures were investigated using immunocytochemical techniques. In neurons of 3-day primary cultures, the control ddY mouse neurons showed dividing stages in about 0.2% of neurofilament (NF)-positive neurons, whereas no dividing neurons were observed among the NF-positive El mouse neurons. In 7-day cultures, localization of GD3 ganglioside in the proliferating control ddY mouse neurons was observed, but there was no GD3 ganglioside in the mutant El mouse neuron. The content of GD3 ganglioside detected by high-performance thin-layer chromatography of El mouse cultured cells was ca. 1/4 of that of ddy mice. These findings suggest that neurons of the El mouse are differentiated earlier than those of the control ddY mouse.

Animals↗
PubMed1987

Clinical significance of mean circulatory filling pressure and cardiac preload under anesthesia.

The circulatory effects of a rapid infusion of plasma substitute with intravenous administration of nitroglycerine (TNG) were investigated in low pressure systems of anesthetized patients by measuring various hemodynamic parameters. Measurements were made when the systolic blood pressure reached 70-80% of the control value after intravenous administration of TNG at 1-2 microg/kg/min and a 3.5% modified gelatin solution (Haemaccel) at a rate of 0.5 ml/kg/min. After the TNG was administered, the mean circulatory filling pressure (Pms) decreased, and the venous to arterial capacitance ratio (CV/CA) increased; however, they returned to control values after a rapid Haemaccel infusion. Changes in the pressure gradient between the X and Y valley of the right atrial pressure wave decreased to 70 +/- 14% of the control value when TNG was given and recovered to 106 +/- 22% by infusion. Pulmonary vascular resistance (PVR) decreased to 70 +/- 24% of the control value when TNG was administered and was restored to 96 +/- 40% by a rapid infusion. In the left ventricle, the mean velocity of myocardial circumferential fiber shortening (VCF) decreased in all cases when TNG was given and it recovered by a rapid infusion. In the right ventricle, VGF did not always decrease, and in a few case increased, but all cases recovered by a Haemaccel rapid infusion. We conclude that the augmentation of the right ventricular preload reserve is achieved by administration of TNG and infusion of a plasma substitute.

Journal Article↗
PubMed1987

The primary structure of a new Mr 18,000 calcium vector protein from amphioxus.

The amino acid sequence of a new Ca2+-binding protein (CaVP) from Amphioxus muscle (Cox, J. A., J. Biol. Chem. 261, 13173-13178) has been determined. The protein contains 161 amino acid residues and has a molecular weight of 18,267. The N terminus is blocked by an acetyl group. The two functional Ca2+-binding sites have been localized based on homology with known Ca2+-binding domains, on internal homology and on secondary structure prediction, and appear to be the domains III and IV. The C-terminal half of CaVP, which contains the two Ca2+-binding sites, shows a remarkable similarity with human brain calmodulin (45%) and with rabbit skeletal troponin C (40%). Functional domain III contains 2 epsilon-N-trimethyllysine residues in the alpha-helices flanking the Ca2+-binding loop. Sequence determination revealed two abortive Ca2+-binding domains in the N-terminal half of CaVP with a similarity of 24 and 30% as compared with calmodulin and troponin C, respectively. This half is also characterized by the presence of a disulfide bridge linking the N-terminal helix of domain I to the C-terminal helix of domain II. This disulfide bond is very resistant to reduction in the native state, but not in denatured CaVP. The optically interesting aromatic chromophores (2 tryptophan and 1 tyrosine residues) are all located in the nonfunctional domain II.

Amino Acid Sequence↗
PubMed1987

(2"-R)-4'-o-tetrahydropyranyladriamycin, a new anthracycline derivative; its effectiveness in lymphoid malignancies.

Thirty-eight patients with adult acute lymphoblastic leukemia (ALL) or non-Hodgkin's lymphoma (NHL) were treated intravenously with (2"-R)-4'-o-Tetrahydropyranyladriamycin (THP) at a dose of 10 mg/m2 for 5 consecutive days. Seven complete and 15 partial responses were observed in 35 evaluable patients (overall response rate, 62.8%). Both antitumor activity and antitumor spectrum were similar to those for doxorubicin. Since the patients who had had chemotherapy previously, including other kinds of anthracycline, responded rather poorly to THP, cross-resistance between THP and other anthracyclines may be present. Leukopenia and thrombocytopenia were dose-limiting factors. Nausea and vomiting episodes were mild, and epilation was also minimal. Although the observation period was short and a cumulative dose was not large enough to evaluate cardiotoxicity, there were no abnormal EKG changes or clinical signs of cardiotoxicity in this study. THP is a potent antitumor agent in the treatment of lymphoid malignancies.

Adult↗
PubMed1987

Rapid separations of diacyl- and dialkylglycerol enantiomers by high performance liquid chromatography on a chiral stationary phase.

Rapid and practical separations of 1,2- and 2,3-diacyl- and dialkyl-sn-glycerol enantiomers as their 3,5-dinitrophenyl-urethane derivatives were carried out by normal-phase high performance liquid chromatography on a chiral stationary phase, N-(R)-1-(alpha-naphthyl)ethylaminocarbonyl-(S)-valine chemically bonded to gamma-aminopropyl silanized silica. Complete separations of the racemates into enantiomers were achieved for both of the diacyl- and dialkylglycerols within 10 min using a stainless steel column (25 cm long) packed with the 5-mu particles, an isocratic elution with a mixture of hexane/ethylene dichloride/ethanol as a mobile phase and a UV detector. The sn-1,2-enantiomers were eluted ahead of the corresponding sn-2,3-enantiomers. Satisfactory separation of the sn-1,3-diacylglycerols from the corresponding enantiomers and the separation of the homologues differing in acyl and alkyl groups were also observed. The formations of hydrogen bonding and charge transfer complex between the urethane derivatives and the stationary phase may contribute to the enantiomer separations.

Acylation↗
PubMed1987

Polyacrylamide gel electrophoresis of several proteins in the presence of sodium oligooxyethylene dodecyl ether sulfates or a commercially available analog.

The behavior of water-soluble proteins and a typical membrane protein in polyacrylamide gel electrophoresis was studied in the presence of sodium oligooxyethylene dodecyl ether sulfates with a defined number of oxyethylene units or a commercially available analog with distribution and heterogeneity for the oxyethylene chain length and alkyl group, respectively. It was concluded that most water-soluble proteins do not interact with the anionic surfactants as long as their oxyethylene chain lengths are sufficiently long; the commercially available surfactant binds exceptionally well to beta-lactoglobulin without causing denaturation and subsequent dissociation; such surfactants are expected to solubilize membrane proteins without causing denaturation as judged from the result with Na+,K+-ATPase and are promising as new solubilizing agents for membrane proteins which enable efficient electrophoretic analysis or separation after the solubilization.

Animals↗
PubMed1987

Heritable fragile sites and cancer: fra(16)(q22) in lymphocytes of an acute nonlymphocytic leukemia patient with inv(16)(p13q22).

Fragile site testing was performed on normal peripheral blood lymphocytes from three acute nonlymphocytic leukemia patients who carried inv(16)(p13q22) in malignant cells. Cultures were treated with BrdU, distamycin A, Hoechst 33258, or folic acid deprivation to induce fragile site expression. One patient was found to be a carrier of fra(16)(q22), but the expression was observed only by Hoechst 33258 treatment.

Acute Disease↗
PubMed1987

Stability properties of oxymyoglobin from chicken gizzard smooth muscle.

1. Oxymyoglobin (MbO2) was isolated directly from the smooth muscle of chicken gizzard and was examined for its spectral and stability properties. 2. When compared with sperm whale MbO2 as a reference, chicken gizzard MbO2 was found to be much more susceptible to autoxidation. Its pH-dependence was therefore analyzed in terms of an "acid-catalyzed three-state model". 3. The complete amino acid sequence of the myoglobin was also determined. Its hydropathy profile revealed that the region corresponding to the distal side of the heme iron appears to be less hydrophobic.

Amino Acid Sequence↗
PubMed1987

Long-term in vitro suspension culture of Toxoplasma and HeLa cells.

To establish a method of mass and long-term propagation of Toxoplasma in suspension cultures and to find a technique for separating the organisms from host cells, basic investigations were carried out in a microcomputer controlled system. By using an arbitrary unit "the medium index" host HeLa cells were continuously supplied to Toxoplasma organisms for about 30 days, at cycles of 4 days. HeLa cells were well infected with Toxoplasma in the suspension cultures by leaving the medium unstirred for 15 min intervals. The separation of Toxoplasma organisms from cells was improved by treating toxoplasmas and HeLa cells mixtures with 0.4% trypsin. The total number of separated organisms obtained from 29 days cultivation period was 4.9 X 10(9). The mean generation time of Toxoplasma organisms on the 0, 10, 20 and 30 day's cultivation was calculated approximately 7.4, 9.4, 9.3 and 7.8 h, respectively.

Animals↗
PubMed1987

Determination of subunit molecular weights of canine renal (Na+,K+)-ATPase by low-angle laser light scattering coupled with high performance gel chromatography in the presence of sodium dodecyl sulfate.

Subunit molecular weights of the (Na+,K+)-ATPase of canine renal outer medulla were estimated in the presence of sodium dodecyl sulfate (SDS) by the measuring system consisted of components connected in the following sequence: a TSK-gel G3000 SW column, a UV spectrophotometer, a low-angle laser light scattering photometer, and a differential refractometer. Polypeptide molecular weights of the alpha- and beta-subunits were determined to be 117,900 and 39,400, respectively. The measurement required the extinction coefficient at 280 nm of the sample polypeptide in addition to the outputs from the three detectors. The extinction coefficients at 280 nm of the alpha- and beta-subunits were determined to be 0.931 and 1.41 ml X mg-1 X cm-1, respectively by the quantitative amino acid analysis. The above procedure seems to be most appropriate to determine uniquely the composition of subunits molecular weights of an oligomeric membrane protein.

Animals↗
PubMed1987

Real-time monitoring of polyacrylamide gel electrophoresis by schlieren optics.

A modernized schlieren optics was applied to follow protein bands visually during polyacrylamide gel electrophoresis. A band containing as little as 0.3 microgram of a protein could be detected. Besides the protein bands, usually overlooked phenomena such as boundary migration of the buffer components could be visualized. As an example, electrophoretic patterns thus obtained for SDS-polyacrylamide gel electrophoresis with a discontinuous buffer system are presented. The use of a split-type colored filter was found to be useful for coloring a particular location on the gel red or blue depending on the sign of the refractive index gradient. This means of detection also seems useful in that, firstly, it makes electrophoretic mobility measurement more quantitative and, secondly, it allows localization of a protein band and sampling in the intact state.

Computer Systems↗
PubMed1987

A microplate method for isolation of viruses from infants and children with acute respiratory infections.

Between December 1984 and December 1986, a microplate technique was adopted for isolation of viruses from infants and children with acute respiratory infections. By using two kinds of tissue culture microplates, i.e., the HHVM plate, containing human embryonic fibroblast (HEF), HEp-2, Vero and MDCK cells, and the MK plate which contains secondary monkey kidney cells, 1,080 field viruses were isolated from 1,061 (24.9%) out of 4,254 throat swabs. Of these 1,080 isolates, 1,003 (92.9%) were recovered in the HHVM plates and the remaining 77 (7.1%) in the MK plates. With the HHVM plate, influenza A and B viruses were cultivated in MDCK, RS virus in HEp-2, parainfluenza and mumps viruses in Vero, adenoviruses in both HEF and HEp-2, polioviruses in HEF, HEp-2 and Vero, coxsackie B viruses in both HEp-2 and Vero, rhino and echo viruses in HEF, herpes simplex virus in both HEF and HEp-2, and cytomegalovirus in HEF, although MK were more sensitive than Vero to parainfluenza and coxsackie B viruses. There was no difference in the rate of isolation of viruses between the microplate and ordinary tube methods. Cross contamination in the microplates was negligible for routine work.

Acute Disease↗
PubMed1987

An epithelioma of the ciliary body.

A 57-year-old woman developed a ciliary body mass which compressed the anterior side of the lens with focal cataract causing the iris to protrude into the anterior chamber. The lesion was removed by a large iridocyclectomy. The mass was classified as an epithelioma of the ciliary body, which was consistent with a benign epithelioma, i.e. an adenoma of the nonpigmented ciliary epithelium. Light and electron microscopic examinations revealed that the tumor cells had characteristics of both the ciliary and iris epithelium, which originated from the neuroectoderm, including abundant cytoplasmic filaments, and pheomelanosomes, and that the gland-like lumen was the pseudoacinous lumen, i.e. invaginated stroma containing the vitreous.

Adenoma↗