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Biomedical subjects

C Y Rhee

Publications and source records attributed to C Y Rhee.

8 recordsLinked to original sources

Creating permanent complete heart block by indirect cauterization without atriotomy.

We created permanent complete heart block (CHB) in 11 dogs without atriotomy by means of indirect cauterization of the atrioventricular (A-V) bundle with a partially insulated wire placed through a small puncture in the atrial wall and guided by palpation. In six acute studies and five chronic studies, all dogs exhibited permanent CHB. To test the block, isoproterenol increased both atrial and ventricular rates 200%-400% without affecting the block. Atropine had no effect on ventricular rate or block.

Animals↗

Estrogen suppression of surgically induced vascular intimal hyperplasia in rabbits.

Since estrogen has been shown to reduce aortic medial hypertrophy in hypertensive rats, a naturally occurring estrogen compound, estradiol, was studied for its ability to suppress the intimal hyperplasia which follows vessel transection and anastomosis. Suture lines and adjacent abdominal aortas were examined by light and electron microscopy 1 month after surgery, in 23 rabbits. Test animals were given 200 microgram of Depoestradiol I.M. weekly, starting 3 days preoperatively. Control animals were similarly manipulated but received no estrogen. Control animals showed striking intimal thickening over the sutures, in contrast to the estrogen-treated group in which there was significantly less growth of corresponding tissue (p less than 0.01).

Animals↗

Relationship between cell surface protease activity and doubling time in various normal and transformed cells.

A sensitive method for measuring cell surface and secreted protease activity utilizing 3H-labelled casein is described. The method is based upon proteolytic degradation of the casein substrate into trichloracetic acid soluble 3H-labelled peptides. Utilizing the radioassay we found that all cultured cell lines examined contain cell surface proteolytic activity which is not secreted into the media. The protease activity was found to be due to protease(s) other than plasminogen activator or plasmin. A comparison of surface protease activity of normal and transformed mouse epidermal cells indicated that the transformed cells contained approximately 3--1 times more proteolytic activity than the normal cells. Surface protease activity was also correlated with the doubling times of various cultured cells. The results indicated that cultured cells with doubling times of greater than three days possess less surface protease activity than cells with shorter doubling times. In order to determine changes in the levels of surface protease activity during the cell cycle several cell lines were synchronized. In synchronized rabbit aortic fibroblasts, mouse transformed epidermal cells and human melanoma cells, a marked increase in surface protease activity was observed during or before mitosis. The protease levels decreased following mitosis. The results suggest that in culture, cell surface protease(s) may be important factor in regulating the rate of cell growth.

Animals↗

Subacute consumption coagulopathy--an unusual complication of angiography.

A 20-year-old female with congenital venous malformations in her left lower extremity had a self-limited, moderate consumption coagulopathy following angiographic studies. This episode was documented by both conventional coagulation studies and by 125l fibrinogen survival studies. It seems likely that venography triggered a local inflammation in the vascular malformations, which resulted in a localized consumption coagulopathy which abated as did the phlebitis in three weeks. We are aware of no prior reports of this complication of venography. Patients with venous malformations who undergo venography should have appropriate coagulation screening performed before and after the procedure so that any similar episode can be promptly diagnosed and treated, if treatment is deemed necessary.

Adult↗