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Biomedical subjects

Y Saeki

Publications and source records attributed to Y Saeki.

At least 253 records · Page 14Linked to original sources
PubMed1980

Elevated contents of spermidine and spermine in the erythrocytes of cancer patients.

Red blood cells (RBC) from 69 patients with advanced cancer and 37 healthy controls were subjected to polyamine determination by using high-performance liquid chromatography. The polyamine contents in normal human RBC were spermidine 15.04 +/- 3.63 nmol and spermine 8.82 +/- 3.12 nmol per 10(10) RBC. Spermidine and spermine levels in RBC were elevated in patients with cancer (p less than 0.005). Serial studies in seven patients with cancer indicated that both polyamines in RBC were reduced after successful surgery. Our data indicate that the determination of polyamine levels in RBC is clinically useful as a marker of disease activity in patients with cancer.

Chromatography, High Pressure Liquid↗
PubMed1980

Transient tension responses of heart muscle in Ba2+ contracture to step length changes.

To characterize mechanical properties of activated heart muscle, kitten papillary muscles in Ba2+ contracture were stretched or released stepwise, and the transient tension responses were analyzed. Various amplitudes of step length change (0.1-1.0% of Lmax) were tested from different initial lengths and at different temperatures. The tension response to either stretch or release showed four different phases, which were nearly symmetric when the input length change was 0.1% of Lmax. When the length changes was 1%, the second phase of stretch response became shorter, whereas that of release became longer. The third phase of stretch response was prolonged, whereas that of release response became obscure. The peak tension (F1) in the first phase was linearly related to the amplitude, whereas those in the second and third phase were not. Increasing temperature markedly decreased F1 and shortened the second and third phase independently of initial muscle length. These results were consistent with those properties of heart muscle in Ba2+ contracture previously characterized with sinusoidal length changes.

Animals↗
PubMed1980

Elevated polyamine content in erythrocytes of malignant lymphoma patients.

The polyamine content in erythrocytes was determined in an attempt to establish a biological marker of tumor growth in patients with malignant lymphoma. Erythrocytes from 24 patients with malignant lymphoma and 40 healthy controls were subjected to polyamine determination, using high-performance liquid chromatography. The spermidine and spermine levels in normal human erythrocytes were 15.06 +/- 3.61 and 8.79 +/- 3.12 nmol/10(10) cells, respectively. Spermidine and spermine levels in erythrocytes of lymphoma patients were 14.16 +/- 4.99 and 13.06 +/- 5.37 nmol/10(10) cells in the stage I and II groups, 21.25 +/- 3.80 and 14.17 +/- 6.11 in the stage III groups, and 34.17 +/- 10.37 and 24.39 +/- 16.08 in the stage IV group, respectively. The levels of both polyamines were significantly elevated (P < 0.005) in erythrocytes of stage IV patients, while those of stage I and II patients were within the normal range. Serial studies in 8 patients indicated that the levels of both polyamines in erythrocytes correlated well with the clinincal state. Thus, the determination of polyamines in erythrocytes should be clinically useful to determine the state of progression of malignant lymphoma.

Adolescent↗
PubMed1978

Sensitive fluorimetric method for the determination of putrescine, spermidine and spermine by high-performance liquid chromatography and its application to human blood.

A fast and sensitive method for the determination of putrescine, spermidine and spermine by high-performance liquid chromatography is described. These compounds are converted to their fluorescent dansyl derivatives and are separated by a reversed-phase chromatographic system (Micropak CH-10) with water and acetonitrile as mobile phase. The sensitivity of the method is 30 pmoles. The application of the method to the determination of polyamines in blood is described. It was found that most of the polyamines circulating in blood are localized in the erythrocytes, their content in normal human blood being spermidine 14.1 +/- 3.1, and spermine 8.4 +/- 2.8 nmoles/ml packed erythrocytes. The polyamine level in serum is less than 0.1 nmole/ml. The polyamine content of the erythrocytes from patients with malignant neoplasms was significantly elevated.

Chromatography, High Pressure Liquid↗
PubMed1978

Dynamic stiffness of cat heart muscle in Ba2+-induced contracture.

We analyzed mechanical properties of kitten papillary muscles both at rest and in Ba2+ contracture by the frequency response method. The muscle length was perturbed sinusoidally, with an amplitude less than 0.3% of Lmax over a frequency range from 0.1 to 60 Hz to determine the dynamic stiffness, F(omega)/L(omega), in which F(omega) = amplitude of the force response wave, L(omega) = amplitude of sinusoidal length wave, and omega = frequency, and the phase shift of F(omega) relative to L(omega). In resting muscles, the dynamic stiffness increased minutely with increasing frequency and the phase relation showed a small lead over the entire frequency range. In muscles in contracture at low temperature (22-24 degrees C), the stiffness first decreased with increasing frequency from about 0.2 to 1 Hz, then increased with a slope of 10-fold/decade, and finally plateaued over the range above 8 Hz. The phase relation showed a small lag between 0.3 and 0.5 Hz, but a clear lead of up to 60 degrees between 0.8 and 16 Hz. With an increase in temperature to 36 degrees C, the peculiar decrease in stiffness and the phase lag in the low frequency region decreased in size and shifted to a higher frequency region (about 4 Hz). These findings led us to two alternative, approximate analogues, which are similar to but simpler than that previously proposed for a twitching papillary muscle.

Animals↗
PubMed1978

[The diagnosis of lumbosacral lipomeningocele by computed tomography (author's transl)].

A case of 2-month-old girl with lumbosacral lipomeningocele was reported. She was admitted for evaluation of a large soft mass in the lumbosacral area, initially noted at birth. On examination, the tumor was 7 cm in diameter and 3 cm in height. The upper part of a mass was cystic. Plain X-ray films revealed bifid lower lumbar and sacal vertebra. Spinal CT scans revealed a mass and bifid spine. An area with EMI units, 2.4+/-4.2, at L4 level and another with EMI units, -52.9+/-5.5, at L5 level were seen extending from within the canal to the subcutaneous tissue. The former was identified as water and the latter as fat. The preoperative diagnosis of lipomeningocele was made. Operation was performed under the operating microscope. A meningocele sac contained no neural element and it's surface was adhesive to lipoma. Lipoma involved cauda equina and conus medullaris in the canal. We removed the extraspinal lipoma with meningeal sac and a part of the intraspinal lipoma to avoid neurological deficit. We consider, like many authors, that intraspinal lipoma should be operated as early as possible with the help of surgical microscope. Early diagnosis is necessary. Myelography is valuable but caution is needed at time of lumbar or cisternal puncture. But spinal computed tomography is noninvasive and allows for precise diagnosis without contrast myelography. CT scan is extremely useful in diagnosing congenital abnormality of the spine.

Cauda Equina↗
PubMed1977

Subunit structure of biodegradative threonine deaminase.

The molecule weight of the biodegradative threonine deaminase from Escherichia coli was determined to be approximately 147,000 by sedimentation equilibrium ultracentrifugation. Similar experiments using 5 M guanidinium chloride gave a value of 39,000 for the molecular weight of the enzyme subunit. On sodium dodecyl sulfate-gel electrophoresis the enzyme also dissociated into a single subunit with an estimated molecular weight of 38,000. The NH2 terminus of the enzyme was determined to be methionine by the dinitrophenylation procedure. Quantitative analysis revealed that 3.6 mol of methionine were detected per 147,000 g of enzyme. The selective tritium labeling method established alanine as the COOH-terminal residue. The sequence of residues at the NH2 terminus, determined using an automated sequence analyzer, was: (formula: see text). The fact that a single amino acid was released at each degradation step in the above experiment strongly suggests that the subunits in the enzyme contain the same amino acid sequence. Therefore, the native enzyme with a molecular weight of 147,000 appears to be composed of four identical polypeptide subunits.

Amino Acid Sequence↗
PubMed1977

End-systolic force-length relationship of nonexcised canine papillary muscle.

End-systolic force-length (F-L) relationships were studied in blood-perfused papillary muscles remining in the canine right ventricle. The muscles contracted spontaneously at a regular rate of 114 +/- 4 (SE, N = 31) beats/min at 37 degrees C. In each muscle, end-systolic F-L curves were obtained in different modes of contraction at different diastolic lengths between the unstressed length (9.4 +/- 0.7 mm) and 143 +/- 4% of it. At the latter length, muscles developed a peak isometric force of 46 +/- 4 g (5.1 +/- 0.5 g/mm2). The isotonic F-L curve was lower than the isometric F-L curves to various extents. An auxotonic F-L curve fell between the two curves. At identical end-systolic lengths peak isometric forces were greater than isotonic forces by 14.4 +/- 1.4% in the first transient beats after switching the contraction mode from isometric to isotonic. The difference increased to 28.5 +/- 3.5% in the steady-state beats. The reduced force in the first isotonic beat was suspected to be due to the uncoupling effect of shortening. The further reduction of isotonic force in the steady-state beats was caused by viscous properties (creep and stress relaxation) and by a gradual decrease in contractility.

Animals↗