Effect of 17beta-estradiol on the Contraction to Endothelin-1 in Porcine Coronary Artery / 대한내과학회지

OBJECTIVES: It is widely accepted that estrogen has favorable effects on cardiovascular diseases, especially in the postmenopausal women. Endothelin-1(ET-I), released from the vascular endothelium, is a 21-amino acid peptide with strong vasoconstrictor activity. However, the effect of estrogen on the vasoconstriction to ET-1 has not been extensively studied. METHODS: To investigate the effect of estrogen (175beta-estradiol) on the vascular contraction to ET-1, porcine coronary artery(PCA) rings were suspended in organ chambers(37 degrees C, 95% O2/5% CO2) for measurement of isometric tension change. Endothelium was removed mechanically if necessary. In acute experiments, vascular rings were preincubated for 15minutes with 3different concentrations of 170beta-estradiol(10(-6), 10(-5), 10(-4)M) and concentration-contraction curves to cumulative doses of ET-1 were constructed. In the experiments after a longer exposure to 17beta-estradiol, the vessels with endothelium were exposed in the 5% CO2 incubator to 3different concentrations of 17beta-estradiol(10(-9), 10(-8), 10(-7)M) for 44-50 hours, and then concentrationcontraction curves to ET-1 were obtained. RESULTS: Incubation for 15minutes with 170beta-estradiol(10(-4)M) inhibited ET-1-induced contraction in the vessels with endothelium(area under the curve and maximal contraction, p<0.05 compared with control). This effect persisted regardless of the sex and the presence or absence of the endotheliurn. Incubation of the vessels far a longer time with 170beta-estradiol(44-50 hours) resulted in the inhibition of maximal contraction to ET-1(p<0.05) by a lower concentration of 175beta-estradiol(10(-7)M) than in acute experiments in male PCA rings, but an enhanced contraction to ET-1(area under the curve; p<0.05) by 10M of 175beta-estradiol was observed in female PCA rings. CONCLUSION: Short-time incubation with 17Pbeta-estradiol has an inhibitory effect on the contraction to ET-1 in PCA rings. This effect is independent of the presence of the endothelium and the sex of the pigs. A longer incubation with 17beta-estradiol results in a similar inhibitory effect on male(but not female) PCA rings, suggesting that a sex-related difference may exist concerning the effect of 17beta-estradiol on ET-1-induced contraction.

A Case of Listeria Monocytogenes Endocarditis in Apparently Healthy Adult

About 50 cases of Listeria monocytogenes endocarditis were reported in worldwide literature in 1950-1995. Though clinical and laboratory data suggest a similarity with other types of bacterial endocarditis, the prognosis is more unfavorable and the mortality rate is higher. However, there has not been a report in Korean literature. We report a case of 55 year-old male with rapidly progressive native aortic endocarditis caused by L. monocytogenes. He had neither history of underlying cardiac disease nor definitive predisposing factor. He presented mild dyspnes, chest pain and febrile sensation for a week. Echocardiography showed large vegetation in aortic valve and severe aortic regurgitation. L. monocytogenes grew on blood culture. We underwent artificial aortic valve replacement due to rapidly progessive heart failure. A thromboembolism occured at right femoral artery on postoperative 2nd day was removed successfully. He discharged without any sequellae.

A Case of Thyroid Abscess by Staphylococcus Aureus / 대한내분비학회지

Acute thyroid abscess is an uneommon type of neck infection. We experieneed a case of staphylococcal thyroid abscess in 29 year old man, diagnosed by needle aspira~tion and culture of the aspirate. The patient had complained fever and slowly growing anterior neck swelling. Needle aspiration of the cold nodule prior to broad spectrum antibiotics was performed. After Surgical excision combined with antibiotics, he was discharged with elinical improvement. The laboratory diagnosis and clinical course was summarized and is reported with relevent references.