A study on the host-tumor relationship, with special reference to protein metabolism.
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Animals↗
Biomedical subjects
M Suda
Publications and source records attributed to M Suda.
Miniaturized detectors for a chemical analysis system.
Recently, several studies about miniaturized chemical analysis systems fabricated with micromachining methods were reported. These systems have some advantages, such as fast response, small amount of sample, and low consumption of reagents, as compared with the conventional system. With such a small system, design of the detector units is very important to monitor analytical performance. This paper introduces some examples of micromachined detectors for miniaturized chemical analysis systems.
Catecholamines↗
Micromachined detectors for an enzyme-based FIA.
Micromachining techniques were applied to construct biosensor systems. The micromachined biosensors have small size, low production cost, and good reproducibility. We made some detection units for flow injection analysis (FIA). An electrochemical flow cell was fabricated, and both the enzyme immobilized column and electrochemical detector were integrated onto the same chip. A chemiluminescence detector was also fabricated and applied to the determination of glucose and lactic acid contained in human serum and urine.
Biosensing Techniques↗
Characterization of telomeric oligonucleotides: fidelity of repetitive nucleotide sequences.
To clarify the reasons for the high fidelity of repetitive telomeric sequences, a series of d(TTXGGG)4 (X: A, G, C, and T) were synthesized and characterized by UV absorption, CD, chemical modification, and resistance to nucleases. d(TTCGGG)4, which is lacking in nature, has similar structural stability and resistance to nucleases, compared with d(TTAGGG)4, which is widely present at the telomeres of many organisms. d(TTGGGG)4 is the most stable as a result of formation of the four G-quartet layers in the presence of potassium ion.
Circular Dichroism↗
Relationship between left ventricular geometry and brain natriuretic peptide levels in elderly subjects.
BACKGROUND: The plasma brain natriuretic peptide (BNP) level in elderly patients is elevated, but the mechanism of this increase is not clear. OBJECTIVE: To examine the relationship between left ventricular geometry and BNP levels in elderly subjects. METHODS: We investigated the effects of left ventricular (LV) geometry on plasma BNP levels by measuring these levels in elderly patients with or without LV hypertrophy. Patients were classified into 4 groups based on echocardiographic data: normal geometry; concentric remodeling; eccentric hypertrophy (EH), and concentric hypertrophy (CH). The samples were analyzed for BNP and endothelin-1 (ET-1). RESULTS: Among the 4 groups, there were no differences in plasma ET-1 levels, ejection fraction, percent fractional shortening, or indices of diastolic function. Plasma BNP levels in EH and CH were higher than those in the normal geometry and concentric remodeling groups. There was a good correlation between plasma BNP levels and the relative wall thickness in EH, and between plasma BNP levels and the posterior wall thickness in CH (r = -0.474, r = 0.396, respectively, both p < 0.05). There were also good correlations between plasma BNP levels and LV mass index (LVMI). A stepwise multiple regression analysis showed that age and LVMI were significant independent contributors to plasma BNP levels. CONCLUSIONS: These results suggest that aging, increased wall stress and the extent of cardiac hypertrophy contribute to elevated BNP levels in the elderly.
Aged↗
A case of xanthinuria: a study on the metabolism of pyrazinamide and allopurinol.
A 74-year-old female was diagnosed as having xanthinuria by measurement of the uric acid level in plasma, purine bases in urine and activity of xanthine oxidase in the duodenal mucosa. The determination of the urinary excretion of purine bases in her family demonstrated a slightly increased urinary excretion of oxypurines in her younger brother, suggesting that he was a heterozygote. The pyrazinamide-loading test and allopurinol-loading test demonstrated that she could neither metabolize pyrazinoic acid into 5-hydroxypyrazinoic acid nor allopurinol into oxypurinol, although there was a slight metabolizing of prazinamide into 5-hydroxypyrazinamide. This suggested that she belonged to the subgroup which can neither metabolize pyrazinamide into 5-hydroxypyrazinamide, pyrazinoic acid into 5-hydroxypyrazinoic acid nor allopurinol into oxypurinol.
Aged↗
Detergent solubilization of liver microsomal acyl-coenzyme A:1-acyl-glycerophosphocholine acyltransferase in nephrotic rat.
Hyperlipidaemia is a common feature of nephrotic syndrome and this has been thought to involve increased assembly and secretion of very low density lipoprotein (VLDL) in the liver. An important pathway for an indirect modulation of VLDL. Synthesis is the reaction catalyzed by the acyl-coenzyme A:1-acyl-glycero-phosphcholine acyl transferase. We therefore investigated the activity of this enzyme in liver microsomes isolated from puromycin amino nucleoside induced nephrotic rats. When oleoyl-CoA was employed as the acyl-donor, our results indicated that both the total and detergent soluble enzyme activities (112.2 +/- 16.7; 116.1 +/- 17.5 units, respectively) were significantly higher than the corresponding control levels of 91.1 +/- 11.1 and 75.4 +/- 20.9 units respectively. The percentage stimulation by sodium cholate were 176.5 and 192.2 for the control and nephrotic rats, respectively. In absence of sodium cholate, when oleoyl CoA was replaced by arachidonoyl-CoA as acyl-donor, the measured total enzyme activity was only significantly reduced in the control rats (71.1 +/- 8.9 Vs 91.1 +/- 11.1 Units). Oleoyl-CoA as acyl-donor gave higher values for the soluble and residual enzyme activities (90.4 13.3; 99.5 34.5 unit) than the corresponding control levels (75.9 +/- 10.0; 50.5 +/- 34.0 units) as compared to arachidonoyl-CoA. In the control group the difference was only significant in the residual activity (92.9 20.5 Vs 64.7 24.1 units). The addition of monomethylethanomine (200 mM) had little or no effect, while both reduced glutathione (10 mM) and 1,2-diacylglycerol (1 mM) caused significant reduction in measured activity. These results indicated that in nephrotic rats new phospholipid synthesis is enhanced and this could contribute to the increased VLDL assembly and secretion usually associated with nephrotic syndrome.
1-Acylglycerophosphocholine O-Acyltransferase↗