Browsing by Author "Liu, Ping-Yen"

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Comparison of Home and Ambulatory Blood Pressure Measurements in Association With Preclinical Hypertensive Cardiovascular Damage
(2019-03-01)
Lin, Ting-Tse
;
Juang, Jimmy Jyh-Ming
;
Lee, Jen-Kuang
;
Tsai, Chia-Ti
;
Chen, Chen-Huan
Objective: To evaluate whether home or ambulatory blood pressure (BP) monitoring was associated with preclinical hypertensive cardiovascular target organ damage (TOD). Methods: We enrolled participants with prehypertension and stage 1 hypertension from 11 medical centers within the Taiwan hypertension-associated cardiac disease consortium. Recordings of clinical BP measurement, ambulatory BP monitoring for 24 hours, and home BP monitoring during morning and evening were made. The measured parameters of target organ damage included left ventricular mass index (LVMI), left atrial volume index (LAVI), and carotid-femoral pulse wave velocity (PWV). Results: Data were collected from 561 study participants (mean age, 65.0 +/- 10.8 years; men, 61.3%). Morning and evening home BP values were slightly higher than the daytime and nighttime ABP values (difference for systolic morning-daytime/evening-nighttime, 7.3 +/- 14.2/11.3 +/- 18.5 mm Hg, P <.001; for diastolic, 5.4 +/- 9.4/ 7.3 +/- 12.1, P <.001). Daytime ambulatory (r = 0.114), nighttime ambulatory (r = 0.130), morning home (r = 0.310), and evening home (r = 0.220) systolic BPs (SBPs) were all associated with LVMI (all P <.05). The correlation coefficient was significantly greater for the relationship between daytime home SBP and LVMI than for the relationship between ambulatory SBP and LVMI (P <.01). The goodness of fit of the association between SBP and LVMI improved by adding home daytime SBP to the other SBPs (P <.001). Similar findings were observed for LAVI, but not for PWV. Conclusion: These findings indicate that morning SBP assessed by home monitoring appears to be a better predictor than other BP measures to determine preclinical hypertensive cardiovascular damage in patients with early-stage hypertension.
High Effectiveness in Actions of Carfilzomib on Delayed-Rectifier K+ Current and on Spontaneous Action Potentials
(2019-10-07)
So, Edmund Cheung
;
Liu, Ping-Yen
;
Lee, Chien-Ching
;
Wu, Sheng-Nan
;
影像與生醫光電研究所
Carfilzomib (CFZ, Kyprolis (R)) is widely recognized as an irreversible inhibitor of proteasome activity; however, its actions on ion currents in electrically excitable cells are largely unresolved. The possible actions of CFZ on ionic currents and membrane potential in pituitary GH(3), A7r5 vascular smooth muscle, and heart-derived H9c2 cells were extensively investigated in this study. The presence of CFZ suppressed the amplitude of delayed-rectifier K+ current (I-K(DR)) in a time-, state-, and concentration-dependent manner in pituitary GH(3) cells. Based on minimal reaction scheme, the value of dissociation constant for CFZ-induced open-channel block of I-K(DR) in these cells was 0.33 mu M, which is similar to the IC50 value (0.32 mu M) used for its efficacy on inhibition of I-K(DR) amplitude. Recovery from I-K(DR) block by CFZ (0.3 mu M and 1 mu M) could be well fitted by single exponential with 447 and 645 ms, respectively. The M-type K+ current, another type of K+ current elicited by low-threshold potential, was slightly suppressed by CFZ (1 mu M). Under current-clamp condition, addition of CFZ depolarized GH(3) cells, broadened the duration of action potentials as well as raised the firing frequency. In A7r5 vascular smooth muscle cells or H9c2 cardiac cells, the CFZ-induced inhibition of I-K(DR) remained efficacious. Therefore, our study led us to reflect that CFZ or other structurally similar compounds should somehow act on the activity of membrane K-V channels through which they influence the functional activities in different types of electrically excitable cells such as endocrine, neuroendocrine cells, smooth muscle cells, or heart cells, if similar in vivo findings occur.