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Biomedical subjects

Y S Hsu

Publications and source records attributed to Y S Hsu.

23 records · Page 2Linked to original sources

Leukotriene C4-induced phosphoinositide hydrolysis in rat basophilic leukemia cell.

Leukotriene C4 (LTC4), one of the major constituents of the slow reacting substance of anaphylaxis, induced a dose-dependent hydrolysis of phosphoinositides in [3H]inositol-prelabeled rat basophilic leukemia (RBL-1) cells. The EC50 for LTC4 to elicit the half maximum accumulation of [3H]inositol phosphates (IPs) was around 20 nM. The increase in the formation of [3H]inositol bisphosphate (IP2) and [3H]inositol trisphosphate (IP3) was detectable at 2 min after the stimulation and progressed up to 30 min. Accumulation of [3H]inositol monophosphate (IP1) was observed only during the late phase of 5-30 min in the presence of LiCl. When cells were stimulated with LTC4 and LTD4 together, there was no additive accumulation in [3H]IPs. Pretreatment of cells with either LTC4 or LTD4 resulted in a decrease in production of [3H]IPs on further stimulation with the same agonist. The desensitization appeared to be heterologous since pretreatment of cells with LTC4 attenuated the responsiveness to LTD4. Conversely, pretreatment with LTD4 also diminished the responsiveness to LTC4 markedly. These results suggest that both LTC4- and LTD4-induced hydrolysis of phosphoinositides are mediated through the same effector in RBL-1 cells.

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[Coronary arterial rupture during percutaneous transluminal coronary angioplasty: a case report].

A case who developed rupture in a diagonal branch of the left anterior descending coronary artery (LAD) during percutaneous transluminal coronary angioplasty (PTCA) is reported here. The present case was 80-year-old man with severe focal stenosis of the LAD at its junction with a diagonal branch. PTCA for the LAD lesion was successfully performed, but occlusion of the diagonal branch developed later. A subsequent ECG showed elevation of an ST segment in a VL, and PTCA for the diagonal branch was attempted. A 018 Hi-torque floppy guide wire was introduced into the occluded diagonal branch, and its dilatation was attempted using a 2 mm Simpson-Robert catheter. During a maximal pressure of 120 psi, a deformity was found at the distal end of the balloon. Post-PTCA angiograms showed rupture of the diagonal arterial branch, and mild to moderate pericardial effusion was observed by echocardiography. The patient experienced transient hypotension (60 mmHg at systolic), but his condition gradually stabilized after the administration of only a pressor medication. Neither pericardiocentesis nor emergency surgery was performed. The next day, follow-up angiograms showed diagonal branch occlusion at the proximal portion of the rupture site. His clinical course was satisfactory with spontaneous resolution of pericardial effusion and mild elevation of his cardiac enzymes (CPK = 243IU). In this case, it was concluded that the cause of coronary arterial rupture was the difference in diameters of the coronary artery (1 mm) and the balloon catheter (2 mm). This was the first rupture case experienced among 750 PTCA sites (0.13%).(ABSTRACT TRUNCATED AT 250 WORDS)

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