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Biomedical subjects

S Eguchi

Publications and source records attributed to S Eguchi.

At least 289 records · Page 16Linked to original sources
PubMed1987

Comparison of red and white muscle wet weight changed by age, denervation and morbid states.

[Na]i, [K]i and wet weight of the extensor digitrum longus (EDL) and soleus (SOL) muscles of 9- and 52-week-old rats were measured for 7 days after sectioning of the sciatic nerve. The changes in wet weight of the EDL and SOL muscles of rats over 52 weeks and those of morbid state rats were also measured. There was no significant difference in wet weights between the EDL and SOL muscles in infant rats, but the EDL muscle became much heavier than the SOL muscle with aging. The decrease in rate of growth of wet weight of the EDL and SOL muscles caused by denervation, was greater in young rats than in mature rats. In addition, the rate of decrease was greater in the SOL muscles than in the EDL muscles in both young and mature rats. The [Na]i increased while [K]i was decreased by denervation, and the net Na+ increase and the net K+ loss were greater in young rats than in mature rats. The changing rate was more remarkable in the EDL muscles than in the SOL muscles throughout the aging process. During DOCA treatment over 4 weeks, the decrease of muscle wet weight was greater in the EDL muscles. The mechanisms which serve to maintain normal muscle wet weight in the SOL muscle after denervation or treatment with DOCA, were discussed.

Aging↗
PubMed1987

Movement of fluorescein and fluorescein glucuronide across the isolated rabbit iris-ciliary body.

Movement of fluorescein and fluorescein glucuronide, a fluorescent metabolite of fluorescein, across the isolated iris-ciliary body of the albino rabbit was determined under short-circuit conditions using a modified Ussing's chamber. The permeabilities of this tissue to these dyes were calculated. The outward permeability (from the aqueous to the stromal side) of the iris-ciliary body preparation averaged 6.63 +/- 0.86 for fluorescein and 1.51 +/- 0.47 X 10(-6) cm/sec for fluorescein glucuronide, and the inward permeability (from the stromal to the aqueous side) was 1.68 +/- 0.41 for fluorescein and 1.37 +/- 0.77 X 10(-6) cm/sec for fluorescein glucuronide, respectively. Application of probenecid or ouabain decreased the outward permeability of fluorescein, but it had no significant effect on the fluorescein glucuronide movement. Application of 10(-5) M 2,4-dinitrophenol showed no significant effect on the fluorescein or fluorescein glucuronide movement, but application of 5 X 10(-4) M 2,4-dinitrophenol decreased the outward fluorescein transfer, which was also markedly suppressed by incubation at 0 degrees C. It is possible that an active transport mechanism is involved in the outward fluorescein movement across the iris-ciliary body, while the inward movement of fluorescein and also the fluorescein glucuronide movement across this tissue is mainly by passive diffusion.

2,4-Dinitrophenol↗
PubMed1987

Thrombosed St. Jude Medical valve prosthesis in the right side of the heart in patients with tetralogy of Fallot.

Five patients who previously had had repair of tetralogy of Fallot underwent pulmonary valve replacement with a St. Jude Medical valve prosthesis for progressive right ventricular failure. One also underwent tricuspid valve replacement. Two of the valves subsequently became thrombotic despite anticoagulant therapy. Because of the high incidence of thrombosis, we conclude that the St. Jude Medical valve prosthesis is not a suitable prosthesis in the right side of the heart in patients with tetralogy of Fallot.

Child↗
PubMed1986

Role played by oxygen in myocardial protection with crystalloid cardioplegic solution.

To evaluate the importance of the oxygen dissolved in crystalloid cardioplegic solution, the protective effects of oxygenated glucose-insulin-potassium cardioplegic solution (O2-GIK) (oxygen tension greater than 600 mm Hg) on the isolated working guinea pig heart were compared with those of deoxygenated (N2-GIK) (oxygen tension less than 10 mm Hg) and aerated GIK solution (GIK) (oxygen tension = 140 to 160 mm Hg). Hearts were subjected to 180 minutes of ischemia with intermittent infusions (every 30 minutes) of cold cardioplegic solution, followed by 30 minutes of normothermic reperfusion. The O2-GIK solution tended to maintain high-energy phosphates at higher levels during ischemia, and resulted in the best recovery of cardiac function. Though not as effective as O2-GIK, GIK solution produced protective effects; N2-GIK solution failed to exert such effects. These results strongly suggest that the protective effects of crystalloid cardioplegic solution are due primarily to the oxygen dissolved in it; anaerobic metabolism or washout of the metabolites plays a minor part.

Animals↗
PubMed1986

Myocardial structure in volume-overloaded hearts before and after valve replacement.

The purpose of this study was to evaluate the histological characteristics of left ventricular muscle in volume-overloaded hearts. A preoperative biopsy was obtained in 31 patients: 14 with mitral regurgitation, 14 with aortic regurgitation and 3 with mitral regurgitation and aortic regurgitation. Postoperative tissue samples were available in 15 patients. Histological findings were correlated with echocardiographic and angiographic data before (preop) and one year after (postop) operation. Myocardial cell diameter was correlated with both the end-diastolic (r = 0.77, p less than 0.01) and end-systolic (r = 0.78, p less than 0.01) dimensions of the left ventricle, but was inversely correlated with the end-diastolic wall thickness-to-radius (h/R) ratio (r = -0.71, p less than 0.01). Percent fibrosis increased proportionally to the diameter (r = 0.42, p less than 0.05). For one year after operation, echocardiographic left ventricular dimensions and angiographic left ventricular volumes were significantly reduced (p less than 0.05), but in some patients postoperative values remained greater than normal. With regard to left ventricular morphology, myocardial cell diameter and interstitial fibrosis decreased significantly after valve replacement (p less than 0.05). However, the myocardial fiber remained hypertrophied and interstitial fibrosis remained above normal after surgery. Thus, postoperative ventricular dilatation was dependent upon the degree of myocardial fiber hypertrophy and interstitial fibrosis.

Cardiomegaly↗