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Biomedical subjects

K Okazaki

Publications and source records attributed to K Okazaki.

At least 397 records · Page 22Linked to original sources
PubMed1986

Effects of food intake and various extrinsic hormones on portal blood flow in patients with liver cirrhosis demonstrated by pulsed Doppler with the Octoson.

In the fasting state the mean portal blood flow demonstrated by the pulsed Doppler system with the Octoson in liver cirrhosis (LC) patients (velocity (PV), 10.2 +/- 3.5 (mean +/- SD) cm/sec, 7.0 +/- 2.6 cm/sec/m2; flow (PF), 579 +/- 262 ml/min, 383 +/- 184 ml/min/m2 (n = 40)) was significantly lower than that in control subjects (PV, 21.2 +/- 5.2 cm/sec, 14.7 +/- 3.9 cm/sec/m2; PF, 966 +/- 344 ml/min, 667 +/- 220 ml/min/m2 (n = 40)). Food intake increased PV by 15% and PF by 15% in LC (n = 8) and increased PV by 56%, PF by 125% in controls (n = 8). Glucagon increased PV by 30% and PF by 52% in LC (n = 10) and increased PV by 50% and PF by 120% in controls (n = 8). Secretin increased PV by 44% and PF by 75% in LC (n = 9) and increased PV by 66% and PF by 142% in controls (n = 8). Vasopressin decreased PV by 42% and PF by 54% in LC (n = 9) and decreased PV by 48% and PF by 62% in controls (n = 8). Insulin, gastrin, and prostaglandin E1 had no effect in either group.

Adult↗
PubMed1986

Reconstruction of electrocardiogram using ionic current models for heart muscles.

A digital computer model is presented for the simulation of the electrocardiogram during ventricular activation and repolarization (QRS-T waves). The part of the ventricular septum and the left ventricular free wall of the heart are represented by a two dimensional array of 730 homogeneous functional units. Ionic currents models are used to determine the spatial distribution of the electrical activities of these units at each instant of time during simulated cardiac cycle. In order to reconstruct the electrocardiogram, the model is expanded three-dimensionally with equipotential assumption along the third axis and then the surface potentials are calculated using solid angle method. Our digital computer model can be used to improve the understanding of the relationship between body surface potentials and intracellular electrical events.

Computer Simulation↗
PubMed1985

DNA sequences responsible for tissue-specific expression of a chicken alpha-crystallin gene in mouse lens cells.

We have studied the DNA sequences required for high-level expression of a cloned chicken alpha-crystallin gene by introducing a hybrid alpha/delta-crystallin gene into nuclei of mouse lens epithelial cells in primary culture. The level of transient expression of the hybrid gene consisting of the 5' upstream promoter region of the alpha-crystallin gene fused to the structural portion of the delta-crystallin gene was determined by Western blot analysis using anti-delta-crystallin serum. The hybrid gene appears to be expressed in a tissue-specific manner, since it is active in mouse lens cells but not in fibroblasts or in L cells. The DNA sequences located 242-189 bp upstream from the transcription initiation site are required for high-level expression in lens cells. They are active when their orientation is reversed at the original site or when placed approximately 1.7 kbp downstream from the cap site in the second intron of the hybrid gene in either orientation. When these DNA sequences were replaced by the enhancer sequences of Moloney murine leukemia virus, the hybrid gene was expressed in both lens cells and fibroblasts.

Animals↗
PubMed1985

A convenient S-2-aminoethylation of cysteinyl residues in reduced proteins.

The cysteinyl residues in proteins had been S-2-aminoethylated with ethylenimine quantitatively. However, ethylenimine is now listed as a carcinogen and is no longer commercially available. A method of converting cysteinyl residues to S-2-aminoethyl derivatives quantitatively using 2-bromoethylamine under mild conditions was developed here.

Chromatography, High Pressure Liquid↗
PubMed1985

Clinical usefulness of the (chloride-90)/phosphate ratio for distinguishing primary hyperparathyroidism from hypercalcemia due to other causes.

In order to obtain a good separation line between patients with primary hyperparathyroidism (1 degree HPT) and those with non-parathyroidal hypercalcemia (NPHC), serum chloride (Cl) and phosphate (P) concentrations were analyzed. Ninety-nine per cent of the patients with 1 degree HPT had a Cl/P ratio greater than or equal to 33, but 29% of patients with NPHC were also included in this range. When the (Cl-90)/P ratio was used to separate into two groups, 98% of the patients with 1 degree HPT had a ratio greater than or equal to 5.0, and 94% of the patients with NPHC had a ratio less than 5.0. From these results, while high sensitivity was achieved both with the Cl/P and (Cl-90)/P ratios, the (Cl-90)/P ratio provided higher specificity. Therefore we conclude that the (Cl-90)/P ratio was excellent in distinguishing 1 degree HPT from other types of hypercalcemia.

Adult↗
PubMed1985

A close association of adriamycin resistance with expression of cell surface antigens in adriamycin-resistant cell lines of herpes simplex virus type 2-transformed Syrian hamster cells.

We determined the properties of three adriamycin (ADM)-resistant cell lines isolated from a clone of herpes simplex virus (HSV) type 2-transformed Syrian hamster cells. The ADM-resistant lines (ADMR-6, -7 and -9) established by continuous exposure of the cells to ADM were 20 to 30 times more resistant to ADM than was the parent line. These resistant lines exhibited cross-resistance to daunomycin, actinomycin D, chromomycin A3 and vincristine, but not to mitomycin C, bleomycin or methotrexate. Uptake and efflux studies with [3H]ADM indicated that one line (ADMR-9) incorporated and retained lesser amounts of [3H]ADM than did the parent line but the other two lines accumulated and retained as much of the drug as did the parent line. Expression of cell surface antigens, detected by immunofluorescence tests with antiserum to HSV type 1, was at a low level (about 8% positive) in the parent line after replating of the cells, although it was enhanced by treatment of the cells with ADM (0.25 micrograms/ml). However, the antigens were strongly expressed (greater than or equal to 35% positive) on the surface of cells of the three resistant lines in the absence of ADM. Both antigen expression and ADM resistance of the cells were relatively stable in in vitro cultivation but were unstable in in vivo cultivation, suggesting that the constitutive expression of the antigens is closely associated with the phenotype of ADM resistance.

Animals↗