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Biomedical subjects

T Kusaka

Publications and source records attributed to T Kusaka.

At least 19 recordsLinked to original sources
PubMed1992

Liquid chromatography-mass spectrometry of hydroxy and non-hydroxy fatty acids as amide derivatives.

A useful method for analyzing fatty acids by liquid chromatography-mass spectrometry with an atmospheric-pressure chemical-ionization interface system has been developed. The sensitivity of six kinds of palmitamide derivatives monitored by a single ion of [M+H]+ was, in decreasing order: N-n-propylamide greater than anilide greater than N,N-diethylamide, amide greater than N,N-diphenylamide greater than N-1-naphthylamide. Individual fatty acids were identified from a mixture of amide derivatives of authentic fatty acids from C16:0 to C30:0 on a mass chromatogram. This method was used to detect both hydroxy and non-hydroxy fatty acids. Many kinds of fatty acid, including hydroxy fatty acids of the rat brain, were detected in a single run.

Animals↗
PubMed1992

[A cardiodynamic study on cardio-assistive effect of the assist device: evaluation on left ventricular dehematizing system].

Of late years, assist artificial heart device has been more and more investigated with subsequent reports being made of its clinical application. Dehematization of left ventricular assist device (LVAD) is divided into two systems, i.e., left atrial dehematization and left ventricular dehematization according to the location of the canula's tip. At present in our country, the former system is being adopted for the majority of LVADs and is generally regarded as preferably acceptable. However, because of low survival rate of LVAD in spite of its comparatively good rate of break-away, not a few cases appear to exist beyond the limit of the former system's effects. Then, compared with the left atrial dehematizing system, LVAD according to the left ventricular dehematizing system was examined for its cardio-assistive effect both blood circulatorily and cardiodynamically. A pneumatically-driven diaphragm type pump was implanted between the left ventricular apex and the descending aorta of a dog and was driven by ECG-synchronous counterpulsation method with heart rate versus pump beating number ratios of 1:1, 2:1 and 4:1 and fixed beating number method with beating number of 60 and 80 beats/min (bpm). In order to measure the left ventricular diameter and myocardial length, 7 pairs of ultrasonic sonomicrometers were embedded intra-left ventriculomurally. Ischemia was prepared by ligating the left anterior descending coronary artery (LAD). Bulk mechanical work and regional mechanical work were calculated from these dimensions and the left ventricular pressure. The following results were obtained: 1) In all driving modes but that of 4:1, compared with non-driven pumping, heart rate, peak left ventricular pressure, mean left atrial pressure and total peripheral resistance showed low values, and mean aortic pressure and total blood flow showed high values. Moreover, in the above driving modes, total bypass was obtained. 2) In the above driving modes, bulk and regional mechanical works were practically null with a de-loading effect of 100% or so being obtained. 3) Compared with the left atrial dehematizing system, peak left ventricular pressure showed remarkably low value with increases in mean aortic pressure and total blood flow, and with remarkable decreases in bulk and regional mechanical works. 4) In driving modes of 2:1, 1:1, I60 and I80, little difference in the effect according to the driving mode was noted.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

[A case of middle lobar bulla associated with severe bronchial asthma].

We experienced a case of middle lobar bulla associated with severe bronchial asthma. Bulla occurs favoritely at apical area and S6, and middle lobar bulla which is very rare has been reported to cause higher ventilatory disorder compared with superior lobar bulla, when it becomes giant. The pathogenesis of the present middle lobar bulla remains unknown, but steroid administration to bronchial asthma may possibly have influenced pleura and/or lung parenchyma. We would like to make its further observation, paying attention to its possible recurrence and its occurrence at other sites.

Adult↗
PubMed1992

[A case of intrathoracic chest wall type lipoma].

Intrathoracic lipoma is a comparatively rare disease. We have recently experienced a case of intrathoracic chest wall type lipoma associated with Charcot-Marie-Tooth disease. The case was a 16-year-old man, in whom preoperative examination of his foot-drop due to Charcot-Marie-Tooth disease pointed out an abnormal chest shadow. Image diagnosis led to intrathoracic chest wall type lipoma. The tumor was easily resectable and was lipoma pathohistologically as well. The literature presented us with 22 cases of such lipoma, which appeared to be predominant for age not more than 10 and age 41-60 and to occur favorably in postero-superior chest wall. Preoperative diagnosis of the present disease became possible to a certain extent by means of CT, MRI. However, in view of imperfect differentiation between lipoma and liposarcoma, surgical resection should be considered, if possibly. No case of intrathoracic lipoma associated with Charcot-Marie-Tooth disease had been reported in the literature, and the causal relationship there between also remains unknown, but to be further examined.

Adolescent↗
PubMed1979

Purification and characterization of 3-hydroxyacyl-CoA dehydrogenase of Mycobacterium smegmatis.

3-Hydroxyacyl-CoA dehydrogenase [EC 1.1.1.35] was purified 100-fold to homogeneity from crude extracts of Mycobacterium smegmatis, using ammonium sulfate fractionation, gel filtration, and chromatography on DEAE-cellulose, hydroxyapatite, and NAD-Sepharose 4B columns. Its molecular weight was estimated to be 50,300 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. NADH acted twelve times more efficiently than NADPH as an electron donor for the reduction of 3-ketoacyl-CoA, and there was strict substrate stereospecificity (L form) in the oxidation of 3-hydroxyacyl-CoA. The pH optimum depended upon the direction of reaction, i.e., 6.0 for the oxidation of NADH and 9--10 for the reduction of NAD. The Km values for different thioesters of acetoacetate, i.e., esters of CoA, pantetheine, and acetyl-cysteamine were determined to be 0.036, 1.19, and 44.4 mM, respectively. Antibodies raised against the dehydrogenase of M. smegmatis strongly inhibited the enzyme activity, but did not affect the corresponding dehydrogenase of pig heart. The antibodies were found to inhibit the acetyl-CoA dependent elongation of fatty acids by the crude extract of M. smegmatis. These findings, together with those on the reconstitution of the elongation activity reported previously (Shimakata, T., Fujita, Y., & Kusaka, T. (1977) J. Biochem. 82, 725-732) indicate that 3-hydroxyacyl-CoA dehydrogenase is involved in the acetyl-CoA dependent elongation of fatty acids in M. smegmatis.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1979

Change in plasma renin activity by cold storage of plasma in normal subjects and patients with essential hypertension and primary aldosteronism.

The time courses of change in renin activity after cold storage of human plasma at -5 degrees C and pH 7.4 were examined in 5 normal subjects, 6 patients with essential hypertension and one female patient with primary aldosteronism before and after extirpation of the adrenal tumor. In the 5 normal subjects and 6 essential hypertensives, the gradual increase in plasma renin activity was observed until 10 days of cold storage. The same result was obtained in the case of primary aldosteronism. However, there was no increase in renin activity despite of cold storage for 10 days in plasma which was sampled from this patient 45 days after operation. These data indicate that a period of 4 days for cryoactivation of human plasma renin as has been reported by Sealey et al. is not sufficient to accomplish activation of renin by cold storage.

Adolescent↗
PubMed1978

Effect of furosemide on urinary kallikrein excretion in patients with essential hypertension.

The effect of furosemide on urinary kallikrein excretion was studied in 10 patients with essential hypertension and 9 normal volunteer subjects. After intravenous administration of furosemide and 2 hours of upright posture, urine volume (UV), urinary sodium (UNaV) and potassium (UKV) excretion, plasma renin activity (PRA), plasma aldosterone concentration (PAC) and urinary kallikrein markedly increased. However, the augmentation of urinary kallikrein in patients with essential hypertension (1.50 +/- 0.19 EU/2 hr) was less remarkable than that in normal subjects (2.33 +/- 0.24 EU/2 hr), although the same degrees of response were observed in PRA and PAC. The increments of UV, UNaV and UKV in patients with essential hypertension were also significantly lower than in normal subjects. Significant positive relations were found between urinary kallikrein and UV or UNaV in both hypertensive and normotensive groups, but there was no such correlation before fursemide administration. It is likely that diuresis and natriuresis induced by furosemide are somehow associated with an increase in urinary kallikrein excretion. Blunted response of urinary kallikrein in essential hypertension may suggest an abnormality in the renal kallikrein-kinin system in this disease.

Adult↗
PubMed1978

Taxonomic study and fermentation of producing organism and antimicrobial activity of mildiomycin.

A taxonomic study of strain B-98891, which produced an antibiotic effective against powdery mildew of barley, identified it as Streptoverticillium rimofaciens. On agar media the antibiotic, which was named mildiomycin, was only weakly active against most fungi and bacteria tested. However, it inhibited some Mycobacterium and Rhodotorula, and it showed excellent control of powdery mildew of barley plants in greenhouse tests at concentrations between 31.2 and 62.5 ppm. Rhodotorula rubra IFO 0907 was selected as the test organism for in vitro assay of mildiomycin.

Antifungal Agents↗
PubMed1977

Acetyl-CoA-dependent elongation of fatty acids in Mycobacterium smegmatis.

An enzyme system of Mycobacterium smegmatis catalyzing the elongation of medium-chain fatty acids with acetyl-CoA was obtained free from de novo fatty acid synthetase by ammonium sulfate fractionation. The system was resolved by gel filtration and DEAE-cellulose chromatography into three fractions, all of which were required for reconstitution of the elongation activity. The three fractions were highly purified enoyl-CoA hydratase, highly purified 3-hydroxyacyl-CoA dehydrogenase, and a fraction containing both enoyl-CoA reductase and thiolase. The reconstituted system was avidin-insenstive, required NADH as a sole hydrogen donor, and was sensitive to pCMB, but not to N-ethylmaleimide or monoiodoacetate. Decanoyl-CoA and octanoyl-CoA were the best primers for the elongation system. When decanoyl-CoA was used as the primer, the major product was found to be a lauroyl derivative (probably lauroyl-CoA). Evidence was obtained suggesting that acyl-CoA dehydrogenase, catalyzing the first step of beta-oxidation, was not functional in the elongation system.

Acetyl-CoA C-Acetyltransferase↗
PubMed1976

Interaction of dopamine, methyldopa and reserpine in the sympatho-adrenal system in essential hypertension.

1. The interactions of dopamine, reserpine and methyldopa on blood pressure of normal subjects and of those with essential hypertension were examined. 2. When biosynthesis of noradrenaline from dopamine was blocked by reserpine, dopamine induced a prominent depressor effect in essential hypertension. 3. The long-term treatment with methyldopa induced a marked potentiateion of the pressor action of domapine in hypertension, although no significant pressor response was found in normal subjects. 4. It is suggested that methylnoradrenaline may accumulate in peripheral nerve endings of patients with essential hypertension in comparison with normal subjects, and this accumulated methylnoradrenaline potentiates the pressor response to dopamine in essential hypertension.

Adult↗