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Biomedical subjects

T Takano

Publications and source records attributed to T Takano.

At least 613 records · Page 34Linked to original sources
PubMed1983

Effects of phospholipids on lysosomal acid lipase purified from rabbit liver.

The effects of phospholipids on lysosomal acid lipase purified from rabbit liver were studied. Non-ionic phospholipids such as phosphatidylethanolamine and phosphatidylcholine increased the enzyme activity. However, anionic phospholipids such as phosphatidylserine, phosphatidylinositol, and cardiolipin were ineffective. The acyl chain length and the degree of unsaturation of synthetic phospholipids were also related to the enzyme activity. Among a series of saturated phosphatidylcholines with different acyl chain lengths, 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine was the most effective. Among a series of unsaturated phosphatidylcholines, the enzyme activity increased in parallel with the number of double bonds. The role of lysosomal acid lipase in relation to phospholipids is discussed.

Animals↗
PubMed1983

Esterastin: a potent inhibitor of lysosomal acid lipase.

The effect of a fungal metabolite, esterastin, on lysosomal acid lipase purified from rabbit liver was studied. Esterastin inhibited the enzyme activity very strongly (IC50, about 80 nM). The inhibition of acid lipase by esterastin was competitive with respect to the substrate and the inhibition constant for esterastin was 90 nM. Esterastin was less inhibitory to other lipolytic enzymes, such as pancreatic lipase and carboxylesterase. Thus esterastin is a potent new inhibitor of lysosomal acid lipase.

Animals↗
PubMed1983

Electrogenic nature of lysosomal proton pump as revealed with a cyanine dye.

Studies were carried out on the electrogenicity of the lysosomal proton pump using dipropylthiadicarbocyanine iodide (diS-C3-(5] as a membrane potential probe. Pure lysosome preparations (tritosomes) quenched the fluorescence of diS-C3-(5). The quenching correlated well with the potassium ion diffusion potential (inside negative) generated by K+ with or without valinomycin. The quenching caused by lysosomes was reversed by lipophilic cations, tetraphenylarsonium (TPA) or triphenylmethylphosphonium (TPMP). Mg-ATP also reversed the quenching, which was inhibited by a protonophore, 3,5-di-tert-butyl-4-hydroxybenzylidene-malononitrile (SF-6847). The properties of the ATP-induced recovery of the quenching were exactly the same as those of ATP-induced acidification, as measured with fluorescein isothiocyanate-dextran (FD) (Ohkuma, S., et al. (1982) Proc. Natl. Acad. Sci. U.S. 79, 2758-2762) and acridine orange (Moriyama, Y., et al. (1982) J. Biochem. 92, 1333-1336), except replacement of the anion by an impermeable one enhanced ATP-induced recovery of quenching, but reduced ATP-induced acidification. Amines which dissipate delta pH across the lysosomal membrane also enhanced the Mg-ATP-induced fluorescence recovery. These results suggest that isolated lysosomes exhibit an inside negative membrane potential, especially in low K+ medium, mostly due to the K+-diffusion potential, and that the Mg-ATP-driven proton pump causes membrane depolarization (in the direction of inside positive). These possibilities were supported by results on the uptake of the radioactive membrane-permeant ions [3H]TPMP and [14C]SCN. The present results provide evidence for the electrogenic nature of the lysosomal proton pump.

Adenosine Triphosphate↗
PubMed1983

Unloading effects of molsidomine on peripheral circulation and cardiac hemodynamics in patients with acute myocardial infarction.

The unloading mechanisms and side of peripheral action of the new antianginal drug molsidomine was compared with isosorbide dinitrate (ISDN) in 14 patients with acute myocardial infarction using a Swan-Ganz catheter and venous occlusion plethysmography. Sublingual molsidomine (2-4 mg) increased calf venous capacitance (CVC) (0.42 +/- 0.18 to 0.64 +/- 0.09 ml/100 ml, p less than 0.05) from 30 to 240 minutes, while simultaneously lowering of PCWP (25.9 +/- 4.9 to 15.8 +/- 7.3 mmHg, p less than 0.05) and CVP (9.3 +/- 3.7 to 5.8 +/- 3.5 cmH2O, p less than 0.05). Calf blood flow (CBF), calf vascular resistance (CVR), CI, TSPR and SWI were not affected significantly. Molsidomine reduced preload more than 240 minutes after its administration. Sublingual ISDN increased CBF into the initial 15 minutes (1.19 +/- 0.49 to 1.83 +/- 0.98 ml/100ml/min, p less than 0.05) and CVC from 5 to 60 minutes (0.42 +/- 0.19 to 0.68 +/- 0.24 ml/100ml p less than 0.01) while simultaneously lowering PCWP (24.3 +/- 2.2 to 14.6 +/- 4.5 mmHg, p less than 0.01) and CVP (9.0 +/- 2.8 to 5.5 +/- 3.5 cmH2O, p less than 0.05). Neither drug affected cardiac index, blood pressure or systemic vascular resistance. These data suggest that molsidomine significantly lowered elevated preload (PCWP/PCP) by dilating venous capacitance vessels. Its length of action was 240 minutes compared with 60 minutes obtained with ISDN, which suggests this new agent may be of marked benefit in the AMI patients suffering from backward failure uncomplicated by forward failure in whom continued preload reduction is necessary. (Results are expressed as the mean +/- standard deviation).

Adult↗
PubMed1983

The relationship between mental disorders and physical severities in patients with acute myocardial infarction.

We studied the relationship between the mental disorders and the mental severities of 163 patients with acute myocardial infarction (AMI), who were admitted to the CCU (Coronary Care Unit) of Nippon Medical School Hospital during the past 2 years. Their mental disorders were diagnosed by psychiatrists, and the relationship between their physical severities according to Killip's classification and their mental severities was investigated. Based on these studies, the authors described the way to manage AMI patients in a CCU, especially from a psychiatric point of view. 1) About 64% of all the patients showed some mental disorders, and many of them were in a state of anxiety or depression. In most of the cases their mental severities were considered to be mild or moderate. 2) We found some correlation between physical severities according to Killip's classification and mental severities (r = 0.3061, p less than 0.005). Many patients with grade I of Killip's classification showed a normal or mild severity, and many with grade II had a mild or moderate severity. About one half of the patients with grades III and IV showed moderate and severe severities, respectively. 3) About 26% of the subjects were in need of psychotropic medication. 4) About 10% of the subjects showed disorientation or cloudy consciousness. The mental severity of patients with an acute lidocaine intoxication was severe. These results showed that there was a significant correlation between physical severity according to Killip's classification and mental severity of AMI patients in the CCU. Patients whose physical severity was not so great showed comparatively mild mental disorders. As Killip's grade of physical severity progressed, mental disorder became more severe.

Adult↗
PubMed1983

Homologous radioimmunoassay for human carboxyl-terminal parathyroid hormone and its clinical evaluation.

An homologous radioimmunoassay for human carboxyl-terminal parathyroid hormone (PTH) was developed using the antiserum raised against synthetic human PTH (46-84) and its clinical evaluation was attempted. Antisera were produced in guinea pigs by immunization with synthetic human PTH (46-84) conjugated with BSA. One of the antisera was used at a final concentration of 1 : 10,000 in the assay, and synthetic human PTH (53-84) for a standard and 125I-Tyr45 human PTH (46-84) for a tracer were used. A standard curve was obtained at concentrations from 0.001 to 10 ng per tube of human PTH (53-84). The displacement curves for human PTH (51-84), human PTH (46-84), Tyr45 human PTH (46-84) and bovine PTH (1-84) were almost identical with the standard curve made by synthetic human PTH (53-84). This antiserum, however, did not recognize the human PTH (1-34) fragment at all. Using this assay system, circulating immunoreactive PTH was measured in normal subjects and patients with parathyroid disorders. Normal PTH values in serum ranged from 0.47 ng/ml to an undetectable level (undetectable in two out of 32 normal subjects) and serum PTH values in patients with primary or secondary hyperparathyroidism or idiopathic hypoparathyroidism were almost completely discriminated from normal values. These results suggest that this homologous radioimmunoassay is a carboxyl-terminal specific assay for human PTH and can be quite useful in clinical practice.

Cross Reactions↗
PubMed1983

Mitral regurgitation associated with aortitis syndrome.

Three patients with mitral regurgitation (MR) associated with aortitis syndrome are presented. All had multiple lesions of the large sized arteries, calcification of the aorta, mild inflammatory findings, a chronic course, and congestive heart failure. MR was observed by ventriculography in all 3 patients. Case 1 had mitral valve prolapse and secondary systemic hypertension. Case 2 showed mildly thickened mitral valve leaflets and had moderate aortic regurgitation (AR). Case 3 had massive AR. The grade of MR was moderate in Cases 1 and 2, and massive in Case 3. The left ventricle was moderately dilated in Cases 1 and 2 but contracted sufficiently and symmetrically in all 3 patients. Other than the prolapse, no significant mitral valve deformity or left ventricular asynergy was evident by ventriculography. The incidence of MR was 3.1% of 128 patients with aortitis syndrome observed in our clinic. MR may be found in the late stage of aortitis syndrome. It may be caused by a mild valvular lesion related to aortitis syndrome and be exacerbated by increased hemodynamic loads such as those which occur in secondary hypertension and AR.

Aortic Arch Syndromes↗
PubMed1983

Evidence in patients with systemic lupus erythematosus of the presence of antibodies against RNA-dependent DNA polymerase of baboon endogenous virus.

Immunoglobulin G (IgG) in six out of 30 patients with systemic lupus erythematosus (SLE) strongly inhibited the activity of RNA-dependent DNA polymerase (RDPase) of baboon endogenous virus, M7, while IgG obtained from scleroderma patients, rheumatoid arthritis patients and normal subjects was less reactive. Experiments with anti-human IgG and with IgG F (ab')2-bound immunoaffinity columns indicated that the inhibition of RDPase was antibody-mediated. The RDPase inhibiting activity of SLE IgG was considered not to be due to cross-reactions of anti-nuclear antibodies including anti-DNA, anti-ribonucleoprotein, anti-Sm and anti-SS.B antibodies. SLE IgG preferably inhibited the RDPase activity of baboon endogenous virus and a feline endogenous virus, RD114. These findings support the hypothesis that retrovirus(es) might be involved in SLE.

Animals↗
PubMed1983

[Changes in immunoglobulin-positive cell populations in the vaginal smear during radiotherapy of cervical cancer and their relation to 5-year survival rate].

To study the immunological response of irradiated cervical cancer, vaginal smears were taken from patients with this neoplasm during radiotherapy and stained with fluorescent anti-Igs sera by a direct method. Then, the relationship between the immune response during radiotherapy and a five year cure were discussed. The results obtained were as follows: 1. The mean percentage of the surface IgM-positive cells was 1.9% in normal vaginal smears and 5.8% in cervical cancer. 2. On the changes in the surface IgM-positive cells during radiotherapy, the patients were classified into three groups. Group A: The number of surface IgM-positive cells increased temporarily during radiotherapy. Group B: The number of surface IgM-positive cells decreased gradually during radiotherapy. Group C: The changes in the surface IgM-positive cells were irregular and/or showed little deviation. The five year survival rate for Group A was 81.8% and for Group B was 50.0%. There was significant difference between Group A and Group B in survival rates, and Group A was considered to be an immunoreactive group.

Female↗
PubMed1983

Lipid composition of low-density lysosomal membrane fraction prepared from atheromatous aorta of cholesterol-fed rabbits.

The lipid composition of low-density lysosomal membranes prepared from atheromatous aorta was analyzed. Results showed that the molar ratio of free cholesterol to phospholipids was 2.4, the phospholipids contained 49% sphingomyelin and 4% phosphatidylethanolamine and the phosphatidylcholine contained 22% polyunsaturated fatty acids. These values for the lipid composition are very different from those for normal biological membranes. The involvement of alteration of lysosomal membranes in accumulation of cholesterol ester in atherosclerosis is discussed.

Animals↗
PubMed1983

[Neoplastic cardiac tamponade].

Pericardial metastases are frequently found and often cause cardiac tamponade which requires emergency treatment. Pericardiocentesis or subxiphoid pericardiotomy and pericardial drainage can be performed; the latter is a safe and effective method for the management of continuous pericardial effusion since it can be done under direct visualization and local anesthesia. We had four patients with neoplastic cardiac tamponade who were treated successfully with subxiphoid pericardiotomy and pericardial drainage. In three of them neoplasms had not been found until cytology of pericardial fluid proved to be malignant when they were attacked by cardiac tamponade. If the patient with malignancy is attacked by cardiac tamponade, subxiphoid pericardiotomy and pericardial drainage should be performed considering neoplastic cardiac tamponade. We have described pathophysiology, diagnosis and treatment of neoplastic cardiac tamponade.

Adult↗