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Biomedical subjects

T Tsuji

Publications and source records attributed to T Tsuji.

At least 937 records · Page 52Linked to original sources
PubMed1988

Accuracy in the noninvasive estimation of pulmonary blood flow by identification of the CO2 uptake system.

Estimation of pulmonary blood flow, controlled by a roller pump, was carried out in dogs using a system identification technique. The system parameters in a linearized CO2 uptake model were estimated by the maximum-likelihood method from the input consisting of alveolar ventilation and inspired pCO2 and the output of end-tidal pCO2. The auto- and cross-correlations of the residuals showed that the model used for estimation was appropriate. The pulmonary blood flow calculated from the system parameters contained a degree of error which showed an average coefficient of variation of 23.8%. Error analysis revealed that the main sources of error lay in the estimates and in the error-magnifying effect arising in the calculation of the flow from these estimates. Reduction of the error in the estimates requires a long set of data for estimation; on the other hand, the error-magnifying effect is determined by physiological constants, so that it cannot be small even in clinical application.

Animals↗
PubMed1988

A case of anomalous origin of the right coronary artery from the pulmonary trunk: imaging of abnormal flow by Doppler color flow mapping.

An asymptomatic 48-year-old woman was admitted to our hospital for evaluation of a precordial continuous murmur. The chest radiograph showed a normal cardiac silhouette. The resting electrocardiogram showed incomplete right bundle branch block. A multistage, graded treadmill exercise test did not affect the ST-T segment. A thallium-201 myocardial perfusion scan with a multistage ergometer exercise test showed no distinct perfusion defect. A two-dimensional echocardiogram disclosed a dilated left coronary artery arising from the left sinus of Valsalva, and a dilated right coronary artery crossing the aorta anteriorly to the pulmonary trunk. Real-time two-dimensional Doppler echocardiography of the same region showed an abnormal jet coming from the right coronary artery into the pulmonary trunk during diastole. A continuous wave Doppler flow study in the pulmonary trunk revealed a high-speed, disturbed flow which began in mid-systole, and continued during diastole. These findings were compatible with anomalous origin of the right coronary artery from the pulmonary trunk. An aortogram confirmed the diagnosis.

Coronary Vessel Anomalies↗
PubMed1988

Hepatocellular expression of a novel glycoprotein with sialylated difucosyl Lex activity in the active inflammatory lesions of chronic liver disease.

Hepatic expression of sialylated difucosyl Lex antigen (SDLex, NeuAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-) was studied with monoclonal antibody FH6, which defines this structure. Hepatocytes in the severe form of chronic active hepatitis and liver cirrhosis strongly expressed SDLex. The antigen was only weakly and focally detected in chronic persistent hepatitis. The mild form of chronic active hepatitis showed intermediate expression. SDLex expressed along the liver cell membranes displayed a honeycomb pattern when extensively expressed in the severe form of chronic active hepatitis or in liver cirrhosis. Cytoplasmic expression was faint and focal. Preferential tissue distribution was at the periphery of the hepatic lobules where the distruction of the limiting plate was present. The antigen was also expressed in sinusoidal lining cells and polymorphonuclear cells but not in the biliary epithelia. Hepatocytes expressing SDLex did not express related carbohydrate antigens, ie, Type 2 chain N-acetyllactosamine, Lex, and sialylated Lea. On subcellular fractionation, the microsome fraction contained the majority of the antigen activity. SDS-PAGE and Western blot analysis revealed one major SDLex-active glycoprotein with an apparent molecular weight of 110 kilodaltons. This glycoprotein was different from SDLex-active glycoproteins found in the sera of cancer patients. No ganglioside showed FH6 reactivity. These results indicate that liver cells in active inflammatory lesion expressed a novel glycoprotein carrying SDLex antigen in honeycomblike membrane-associated pattern.

Acute Disease↗
PubMed1988

[Intracranial pressure irregularities induced by bulbar stimulation in experimental subarachnoid hemorrhage].

Neurogenic mechanisms of pressure waves were investigated in dogs with acute intracranial hypertension. After subarachnoid infusion of hemolyzed red blood cells, simultaneous recordings of both systemic blood pressure (SBP) and intracranial pressure (ICP) were made continuously. Pressure waves could be induced by electrical stimulation of the medulla oblongata at the stage of increased ICP. Induced pressure waves were specific at the site of the stimulation. These pressure waves were classified into 3 types, consisting of fast waves, slow waves and rebound waves. The fast waves had a duration of 10-30 seconds, being accompanied by a marked increase of SBP. These waves were induced by stimulation of various portions of the lateral reticular formation. The slow waves had a duration of 30 seconds to 3 minutes, being accompanied by a decrease or little change of SBP. These waves were induced by stimulation of the lateral portion of lateral reticular formation. The rebound waves had a duration of 30 seconds to 3 minutes, followed by a decrease of SBP. These waves were induced by stimulation of the lateral area of the solitary tract nucleus. At the end stage of intracranial hypertension, electrical stimulation of all of these sites induced changes of ICP depending on SBP. Slow waves were increase the intracranial pressure during arterial depressor responses indicating primary cerebral vasodilatation. It is suggested from these data that cerebral vascular tonus is concerned with the lateral portion of lateral reticular formation.

Animals↗
PubMed1987

Characterization of disulfide bonds in recombinant proteins: reduced human interleukin 2 in inclusion bodies and its oxidative refolding.

Cloned cDNA of human interleukin 2 (IL-2) was expressed in Escherichia coli cells in which IL-2 formed insoluble inclusion bodies. Human IL-2 has three Cys residues, namely, Cys-58, Cys-105, and Cys-125, and native IL-2 has an intramolecular disulfide bond between Cys-58 and Cys-105. Since the formation of inclusion bodies was thought to be due to disorder in the oxidation state of these Cys residues, all intramolecular disulfide bond isomers of IL-2 were prepared by denaturation of native IL-2 to characterize the state of a disulfide bond in IL-2 in the inclusion bodies. These isomers can be separated from native IL-2, reduced IL-2, and IL-2's with intermolecular disulfide bonds by means of reversed-phase high-performance liquid chromatography. Human IL-2 produced in inclusion bodies in E. coli carrying a recombinant DNA was analyzed by HPLC and was proved to be a fully reduced form with no intra- and intermolecular disulfide bonds. Refolding of reduced IL-2 in the presence of reduced and oxidized glutathione and a low concentration of guanidine hydrochloride resulted in the formation of the biologically active IL-2 quantitatively. Further purification provided a practically pure IL-2 preparation without contamination of any disulfide bond isomers.

Amino Acid Sequence↗
PubMed1987

Crystallization and preliminary X-ray studies of human recombinant interleukin-2.

Two different forms of crystals (potentially) suitable for x-ray structure analysis were obtained for recombinant human interleukin-2 (IL-2) using ammonium sulfate as a precipitant in the pH range of 6.3-7.3 (in the case of hexagonal bipyramidal crystals) and 4.5-5.5 (in the case of plate crystals). The hexagonal bipyramidal crystal belongs to a hexagonal space group P6(2)22 or P6(4)22 with a = b = 105.8 A and c = 122.2 A. The crystal diffracts up to 3.4 A resolution and contains 2 or 3 IL-2 molecules in an asymmetric unit. The plate crystal belongs to an orthorhombic space group P2(1)2(1)2 with a = 47.9 A, b = 79.6 A, and c = 31.9 A. The crystal diffracts up to 2.5 A resolution and contains only 1 IL-2 molecule in an asymmetric unit. These facts reconfirmed crystallographically the high homogeneity of the present preparation of human recombinant IL-2.

Cloning, Molecular↗
PubMed1987

Local structural features around the C-terminal segment of Streptomyces subtilisin inhibitor studied by carbonyl carbon nuclear magnetic resonances three phenylalanyl residues.

The carbonyl carbon NMR signals of the Phe residues in Streptomyces subtilisin inhibitor (SSI) were selectively observed for [F]SSI, in which all phenylalanines were uniformly labeled with [1-13C]Phe. The three enhanced resonances in the spectrum of [F]SSI were unambiguously assigned to the specific sites in the amino acid sequence by means of 15N,13C double-labeling techniques. Namely, the resonances at 174.9 and 172.6 ppm (in D2O, pH 7.3, 50 degrees C) showed the satellite peaks due to 13C-15N spin coupling in the spectra of [F,GS]SSI and [F,A]SSI, in which Ser/Gly and Ala residues were labeled with [15N]Gly/Ser and [15N]Ala, respectively, together with [1-13C]Phe. The carbonyl groups of Phe-97 and Phe-111 are involved in peptide bonds with the amino nitrogens of Ser-98 and Ala-112, respectively. These results clearly indicate that the signals at 174.5 and 172.6 ppm are due to Phe-97 and Phe-111, respectively. The signal at the lowest field (177.1 ppm) was thus assigned to the carboxyl carbon of the C-terminal Phe-113. The lifetimes of the amide hydrogens of the three Phe residues and their C-terminal-side neighbors (Ser-98 and Ala-112) were investigated by using the effect of deuterium-hydrogen exchange of amide on the line shapes (DEALS) for the Phe carbonyl carbon resonances. In this method, the NMR spectra of [F]SSI dissolved in 50% D2O (pH 7.3) were measured at various temperatures, and the line shape changes caused by deuteriation isotope shifts were analyzed.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1987

Purification and characterization of erythroid differentiation factor (EDF) isolated from human leukemia cell line THP-1.

We isolated a protein, from a cell line of human origin, which exhibits extensive differentiation inducing activity toward Friend leukemia cells. The protein, called Erythroid Differentiation Factor (EDF), was found in a 4 day culture of THP-1 cells performed in the presence of 4 beta-phorbol 12-myristate 13-acetate(PMA). EDF is a homodimer of a molecular weight of 25,000, with an NH2-terminal sequence identical to that of the beta A-chain of porcine Inhibin. It was suggested that a single protein species is responsible for the activities of both EDF and FRP, a FSH releasing protein isolated from porcine ovarian follicular fluid.

Activins↗
PubMed1987

Patient monitoring during and after open heart surgery by an improved deep body thermometer.

The deep body thermometer developed by Fox was improved by Togawa by thermal insulation of the probe. The present status of medical progress in clinical thermometry through the improved deep body thermometer was reviewed from the view point of cardiac surgery. The forehead and sole temperatures obtained by this improved thermometer were monitored and recorded by a multipotentiometric recorder continuously up to 12 days in the patients admitted to the ICU who underwent open heart surgery. The forehead tissue temperature measured by this thermometer is slightly lower than and parallel to the rectal temperature, being close to the pulmonary arterial blood temperature. On the other hand, the sole tissue temperature fluctuates from room temperature to the forehead tissue temperature, sometimes showing rhythmic changes. The former seems to be the core temperature and the latter, the shell temperature. The dissociation when the two temperatures are more than 7 degrees C apart from each other suggests that the hemodynamical condition is worse than in the convergence when they remain within 2 degrees C. A state of shock can be diagnosed when the arterial systolic pressure is less than 90 mmHg and the urine output less than 1 ml/min/mg in addition to the dissociation. The effect of treatment and the prognosis for the patient are predictable according to the trends of the two temperatures as divergent or convergent. The dynamic thermometry by this thermometer is very informative and the procedure is noninvasive without discomfort to the patient.

Adult↗
PubMed1987

Specific cell surface labels in the visual centers of Xenopus laevis tadpole identified using monoclonal antibodies.

Monoclonal antibodies (MAbs) against the optic tectum of Xenopus tadpoles were generated and screened by the immunofluorescent staining of frozen sections of tadpole brains. MAb-A5 stains the 8th and 9th plexiform layers of the optic tectum, whereas MAb-B2 stains all but the eighth and ninth plexiform layers of the optic tectum. MAb-A5 antigen is also detectable in the nucleus of Belonci, the corpus geniculatum thalamicum, the pretectal area, and the basal optic nucleus, all targets of the optic nerve, but is not detectable in the optic nerve or the optic tract. On the other hand, MAb-B2 does not stain any of these visual centers, though many fibers surrounding them are stained. Eye-enucleation experiments showed that MAb-A5 antigen is expressed in the optic tectum even when it is not innervated by optic nerves. Staining of viable brains with these MAbs indicates that these antigens are cell surface molecules. Immunoadsorption followed by SDS-PAGE suggests that proteins are constituents of these antigens. The MAb-A5 antigen in the diencephalon and the mesencephalon is not detectable at stage 35/36, but is detectable at stage 39 when the optic nerves begin to innervate the optic tectum. The spatial as well as the temporal patterns of the expression of the MAb-A5 antigen suggest that this molecule may be involved in the target recognition of optic nerve fibers.

Animals↗
PubMed1987

Vapor compression distiller and membrane technology for water revitalization.

Water revitalization for a space station can consist of membrane filtration processes and a distillation process. Water recycling equipment using membrane filtration processes was manufactured for ground testing. It was assembled using commercially available components. Two systems for the distillation are studied; one is an absorption type thermopervaporation cell and the other is a vapor compression distiller. Absorption type thermopervaporation able to easily produce condensed water under zero gravity was investigated experimentally and through simulated calculation. The vapor compression distiller was studied experimentally and it offers significant energy savings for evaporation of water.

Absorption↗
PubMed1987

Changes in proton T1 in dog brains due to the administration of haloperidol.

Changes in proton T1 in dog brains due to the administration of haloperidol were determined by the intravenous administration of a single dose of 20 mg of haloperidol to mongrel dogs. The MRI used was the Aberdeen type with the static magnetic field of 0.1 T. A coil made exclusively for these animals (bore diameter 120 mm) was used. There was a significant increase in the T1 value in the striate body 30 minutes and more (within two hours) after the administration of haloperidol. Subtraction images were also obtained by subtracting the image of the pre-treatment (control) T1 values from the image of the post-treatment values (2 hours after the injection). The subtraction images also revealed increases in the T1 values of the striate body.

Animals↗