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Biomedical subjects

K Torizuka

Publications and source records attributed to K Torizuka.

At least 325 records · Page 18Linked to original sources
PubMed1982

Deferoxamine, a promising bifunctional chelating agent for labeling proteins with gallium: Ga-67 DF-HSA: concise communication.

A new efficient method has been developed for the labeling of various biologically important proteins with radiogallium, using deferoxamine (DF) as a bifunctional chelating agent. Human serum albumin (HSA) was chosen for studying the DF coupling reaction by a glutaraldehyde two-step method. The DF-HSA conjugate obtained was then easily labeled with Ga-67 with high efficiency and reproducibility. High stability of the Ga-67 DF-HSA was observed both in vitro and in vivo. In rats the half-time of blood clearance at the first phase was 234 min for the Ga-67 DF-HSA, whereas most conventional I-131 HSA gives 121 min. The excellent pharmacological and physiological properties were assessed by plasma clearance and plasma volume measurements in normal volunteers. Even at 2 hr after injection, (90.0 +/- 3.0)% of Ga-67 DF-HSA was retained within the vascular space. The mean plasma volume per kilogram of body weight, measured with Ga-67 DF-HSA, was 46.6 +/- 3.4 ml/kg, compared with 52.2 +/- 2.4 ml/kg as determined with I-131 HSA in the same men.

Animals↗
PubMed1982

[Assessment of left ventricular function at rest and during exercise by gated cardiac blood pool scan and pressure measurement of the pulmonary artery by Swan-Ganz catheter].

Gated cardiac blood pool scan and hemodynamic parameters by Swan-Ganz catheter were simultaneously measured in five normal subjects (Group A), five patients with coronary artery disease (CAD) without angina on exercise (Group B) and nine patients with CAD with angina on exercise (Group C) in order to evaluate left ventricular function at rest and during supine bicycle ergometer exercise. Work load was gradually increased every 3 minutes and each data were acquired using a digital computer. There was a fairly good correlation (r = 0.83) between stroke volume by thermodilution method and stroke counts corrected by counts/ml of blood on gated cardiac blood pool scan, which were obtained by subtraction of end-systolic counts (ESC) from end-diastolic counts (EDC) in the region of interest arranged at the left ventricle. Stroke counts obtained by this method are considered to reflect a change in the left ventricular volume during exercise. As to the correlation between pulmonary capillary wedge pressure (PCWP) and stroke work index (SWI) at peak exercise, there was a large increase in SWI (78.9 +/- 17.6 to 112.3 +/- 30.0 g X m/m2) with a small rise in PCWP (10.0 +/- 1.9 to 16.2 +/- 4.0 mmHg) in Group A. In Group B, SWI was increased (57.8 +/- 15.8 to 92.9 +/- 25.2 g X m/m2) with a moderate rise in PCWP (11.8 +/- 3.7 to 20.0 +/- 3.1 mmHg) at peak exercise. In Group C, there was a trivial increase in SWI (74.0 +/- 16.0 to 81.2 +/- 29.3 g X m/m2) despite a marked rise in PCWP (13.1 +/- 3.1 to 33.4 +/- 8.9 mmHg). Similar relationship was present between SWI and EDC. On mild exercise of 25w, however, the rise in PCWP was more prominent rather than the increase in EDC in Group C. This indicates that the left ventricle in Group C is operating on a very steep portion of the diastolic pressure-volume curve.

Adult↗
PubMed1981

[Studies on the measurement of vitamin D derivatives in human plasma. I. A competitive protein binding assay for 25-hydroxyvitamin D in plasma (author's transl)].

A simple and precise method has been developed for the determination of 25-hydroxyvitamin D in 1 ml of human plasma. The method consists of methanol/chloroform extraction, purification by high pressure liquid chromatography and a competitive protein binding assay using vitamin D deficient rat serum. The ethanol extract from vitamin D deficient chick serum was added to the sample before CPBA to eliminate the non-specific interference in the CPBA system as a vitamin D free serum extract. The assay was sensitive to 0.72 ng/ml of plasma. Satisfactory results were obtained in the dilution and recovery tests. The coefficients of variation were 5.8 approximately 9.1% for the within-assay, and 7.4 approximately 10.3% for the between-assay. Plasma concentrations of 25-hydroxyvitamin D in 46 samples of normal human plasma were 21 +/- 10.5 ng/ml (mean +/- SD), and the seasonal variation was demonstrated. Plasma levels for 25-hydroxyvitamin D were high in patients receiving vitamin D2 and low in patients suffering from liver cirrhosis.

25-Hydroxyvitamin D 2↗