Transesophageal echocardiography (TEE): its diagnostic value in endocarditis

Transthoracic two-dimensional echocardiography (TTE) has been an accepted noninvasive procedure used to diagnose infective endocarditis by demonstrating the presence of vegetations and other complications such as ring abcess, mycotic lesions or sinus of valsalva aneurysm. Moreover, complementary Doppler and Color Flow imaging are very useful in detecting early valvular regurgitation and in evaluating the severity of such regurgitant lesions. Occasionally, TTE fails to provide an adequate quality of imaging because of the patient's obesity, chest deformity or emphysema. Transesophageal echocardiography (TEE) on the other hand, a relatively new technique, allows ultrasonic imaging of the heart through the esophagus and provides a clear visualization of all cardiac structures without any interference from the lungs, chest wall or rib cage. We present a case of aortic valve endocarditis diagnosed by TEE.

Inhibitory and stimulatory effects of glucocorticoid on androgen-induced growth of murine Shionogi carcinoma 115 in vivo and in cell culture

It has been generally accepted for 20 years that the growth of Shionogi carcinoma 115 (SC115) is stimulated only by androgen in vivo and in cell culture. However, we recently found that the growth of SC115 is also stimulated by pharmacological, but not physiological, doses of glucocorticoid both in vivo and in cell culture and by pharmacological doses of estrogen only in vivo. In the present study, therefore, we investigated the effect of dexamethasone on androgen-induced growth of SC115 cells in vivo and in cell culture. In a serum-free medium [Ham's F-12:Eagle's minimum essential medium (1:1, v/v) containing 0.1% bovine serum albumin], the proliferation of SC-3 cells (a cloned cell line from SC115 cells) estimated by cell number and DNA synthesis reached a plateau at 10(-8) M testosterone (up to 93-fold) or 10(-6) M dexamethasone (up to 7.2-fold); high stimulation induced by higher than 10(-8) M testosterone was inhibited by the addition of 10(-5)-10(-8) M dexamethasone in a concentration-dependent manner, whereas low stimulation induced by lower than 10(-10) M testosterone was significantly enhanced by the addition of dexamethasone. The presence of typical glucocorticoid and androgen receptors in SC-3 cells was also demonstrated; dexamethasone did not bind to androgen receptor and testosterone did not bind to glucocorticoid receptor. In castrated mice, the concomitant administration of dexamethasone again significantly inhibited the high growth of SC115 tumors induced by high doses of androgen but significantly enhanced the low growth induced by low doses of androgen. The present results demonstrate both inhibitory and stimulatory effects of glucocorticoid on androgen-induced proliferation of SC115 cells in cell culture and probably in vivo.

Growth-stimulating effect of pharmacological doses of glucocorticoid on androgen-responsive Shionogi carcinoma 115 in vivo in mice and in cell culture

It has been generally accepted for 20 years that the growth of Shionogi carcinoma 115 (SC115) is stimulated only by androgen. However, we recently found that the growth of SC115 cells is also stimulated by pharmacological doses of estrogen in vivo but not in cell culture. In the present study, the growth-stimulatory effect of glucocorticoid on SC115 cells was examined. In castrated mice, daily injections of high doses of dexamethasone (100 micrograms/mouse) markedly stimulated the tumor growth, and the growth approached that found in normal males. However, daily injections of physiological doses of dexamethasone (4 micrograms/mouse) or high doses of epitestosterone, progesterone, or cholesterol (200-5000 micrograms/mouse) did not enhance the tumor growth in castrated mice. The androgen dependency, growth speed, steroid receptors, and histological type of the tumors grown by pharmacological doses of glucocorticoid were not significantly different from those of the original SC115 tumors grown by androgen. In a serum-free medium [Ham's F-12:Eagle's minimum essential medium (1:1, v/v) containing 0.1% bovine serum albumin], the proliferation of SC-3 cells (a cloned cell line from SC115 cells) was markedly (by up to 25-fold) stimulated by 10(-10)-10(-8) M testosterone, whereas the proliferation was only slightly but significantly (by up to 3.3-fold) stimulated by 10(-8)-10(-5) M dexamethasone. The present findings demonstrate that the growth of SC115 cells in vivo and in cell culture is significantly stimulated by physiological doses of androgen or pharmacological doses of glucocorticoid.