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Biomedical subjects

T Ozawa

Publications and source records attributed to T Ozawa.

At least 19 recordsLinked to original sources
PubMed1979

An experimental study of release arrhythmia: Occlusion time-dependent changes in ventricular fibrillation threshold.

There have been many reports about ventricular arrhythmias during acute coronary occlusion. Nevertheless, it is only recently that interest has been taken in the occurrence of ventricular arrhythmia after reperfusion following coronary occlusion. To investigate the mechanism of the latter kind of arrhythmia, we studied the effect of changing the duration of occlusion time on the recovery time courses of the VMRT (Ventricular Multiple Response Threshold), and of the A-V differences in the serum K+ concentration across the heart. The time course of delta K+ recovered soon after reperfusion, while changes in VMRT needed more time for recovery to the initial state. Concerning heart rate, blood pH, and the levels of Na+, Cl-, and Ca++, no significant changes were detected. There was no relation between the time courses of VMRT and those of the A-V differences in serum K+. Consequently, time courses in VMRT were dependent upon the duration of coronary occlusion time. A possible explanation for these results may be that the longer the duration of the preceding occlusion time, the more severe the myocardial damage due to myocardial ischemia.

Animals↗
PubMed1979

Immune-complex glomerulonephritis associated with cytomegalovirus infection.

Histologic and immunopathologic studies were performed at autopsy on the kidneys of a patient in whom hematuria and proteinuria developed in association with cytomegalovirus (CMV) pneumonitis. Light microscopic examination of the kidneys revealed focal mesangial proliferative glomerulonephritis. Immunofluorescent microscopy revealed a granular deposition of IgG, IgA, C3, and C4, mainly in the mesangium. CMV antigens were also demonstrated in a similar immunofluorescent pattern. Glomerulus-bound immunoglobulins were eluted and demonstrated to contain antibodies to CMV antigens. These findings suggest that in some patients who have CMV infection immune-complex glomerulonephritis is induced by glomerular deposition of CMV antigen-antibody complexes.

Antigens, Bacterial↗
PubMed1979

Hydrolysis of cefamandole nafate in dialysis patients.

The hydrolysis of cefamandole nafate was examined in vivo in five dialysis patients and five subjects with normal renal function. The plasma half-life of cefamandole was prolonged in the patients with renal failure compared with normal subjects (18.3 +/- 4.5 [standard deviation] versus 10.35 +/- 1.4 min, P less than 0.01). The pharmacokinetics of cefamandole nafate best fit two-compartment, open-model kinetics. We conclude that patients with severe renal failure are capable of hydrolyzing cefamandole nafate to cefamandole and formate at a rate sufficiently rapid so as not to allow an accumulation of cefamandole nafate. The difference in half-life may be related to urinary excretion of cefamandole nafate in normal individuals.

Adult↗
PubMed1979

Protection of chlorpromazine-induced arrhythmia by flavin-adenine-dinucleotide in canine heart.

To investigate the mechanism of chlorpromazine(CPZ)-induced ventricular arrhythmia, the changes in ventricular fibrillation threshold (VFT) were followed after intravenous injection of CPZ (1 mg/Kg) in dogs. Following injection, VFT was decreased to 56.6 +/- 5.4% (mean +/- SE) of the initial level. Since flavin-adenine-dinucleotide (FAD) combines specifically with CPZ in vitro, we investigate whether or not prior treatment with FAD prevents the CPZ effect. With FAD (2 mg/Kg), the CPZ-induced decrease in VFT was significantly cancelled (92.2 +/- 4.2% of the initial level). Mitochondria isolated from canine heart after CPZ injection showed a significant decrease in respiratory control index and ADP/O. Effects of CPZ on canine heart mitochondria were also well cancelled by prior administration of FAD. The findings suggest that the arrhythmogenic action of CPZ might be associated in part with impaired function of heart mitochondria. These results also suggest that FAD might be useful in the treatment of the cardiac disturbances associated with overdosage of CPZ.

Animals↗
PubMed1978

Prevention of cystoid macular edema after lens extraction by topical indomethacin (III) radioimmunoassay measurement of prostaglandins in the aqueous during and after lens extraction procedures.

The amounts of Prostaglandin (PG) E and F2alpha in the aqueous humor were measured by radioimmunoassay techniques before and immediately after intracapsular and extracapsular cataract extractions. We found that: 1. The levels of PG E and PG F2alpha are elevated by cataract extraction. 2. The elevated levels of PGs can all be prevented by preoperative applications of topical indomethacin. 3. No differences in the amounts of PGs biosynthesized during intracapsular and extracapsular lens extraction were found. 4. In some cases, the levels of PG E were still elevated one week after surgery. These findings were used as the basis for our attempts to define the causes of cystoid macular edema (CME) following lens extractions.

Aged↗
PubMed1978

Electron spin resonance studies of radicals obtained by the reaction of alpha-tocopherol and its model compound with superoxide ion.

alpha-Tocopherol (vitamin E) and its model compound, 6-hydroxy-2,2,5,7,8-pentamethylchroman, were found to be oxidized by O2- to yield free radicals which were detected at room temperature by ESR spectroscopy. The ESR spectra of these radicals showed seven main lines with additional hyperfine structure and have the same g-values at 2.0046. Assignments of the ESR spectra were done on the basis of the spectra of the free radicals of deuterated hydroxypentamethylchroman obtained from the same reaction with O2-. The radicals observed are chromanoxyls generated by the abstraction of hydrogen from the 6-hydroxy group of tocopherols.

Electron Spin Resonance Spectroscopy↗
PubMed1978

Enzyme-linked immunospecific antibody test for detecting antibody to Klebsiella.

The enzyme-linked immunospecific antibody test was performed in standard test tubes and microtiter plates to meausre high-titer antibody against Klebsiella capsular polysaccharide. Initial studies were conducted with rabbit sera; other studies were conducted with the serum of a patient infected with type 9 Klebsiella. Both immunized rabbits and an infected patient disclosed high titers of anticapsular antibody. Control sera from other immunized rabbits and other infected humans failed to show this substantial antibody titer against type 9 Klebsiella. Comparisons between counterimmunoelectrophoresis and indirect immunofluorescence disclosed that the sensitivity of the enzyme-linked immunospecific antibody test for anti-Klebsiella antibody ranged between 400 and 10,000 times that of these tests.

Antibodies, Bacterial↗