Browsing by Author "So, Edmund Cheung"

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Dual-wavelength fiber-optic technique to assist needle cricothyroidotomy
(1970-01-01)
Lee, Chien-Ching
;
Chuang, Chia-Chun
;
Lai, Bo-Cheng
;
Lu, Chin-Li
;
So, Edmund Cheung
The traditional needle cricothyroidotomy procedure is performed blindly without any medical equipment. Complications including posterior tracheal wall perforation, accidental vessel puncture, and missed tracheal puncture are reported. Therefore, we proposed a dual-wavelength fiber-optic technique based on the technique of near-infrared spectroscopy to assist operators performing needle cricothyroidotomy in a swine model. We embedded optical fibers in a 16-gauge intravenous needle catheter. Real-time data were displayed on an oscilloscope, and we used the program to analyze the data immediately. The change of optical density corresponding to 690-nm and 850-nm wavelengths and hemoglobin parameters (HbO(2)and Hb concentrations) was analyzed immediately using the program in the laptop. Unique and significant optical differences were presented in this experiment. We could easily identify every different tissue by the change of optical density corresponding to 690-nm and 850-nm wavelengths and hemoglobin parameters (HbO(2)and Hb concentrations). Statistical method (Kruskal-WallisHtest) was used to compare differences in tissues at each time-point, respectively. Thepvalues in every tissue in optical density change corresponding to 690 nm and 850 nm were all < 0.001. Furthermore, thepvalues in every tissue in Hb and HbO(2)were also all < 0.001. The results were statistically significant. This is the first and novel study to introduce a dual-wavelength embedded fibers into a standard cricothyroidotomy needle. This proposed system might be helpful to provide us real-time information of the advanced needle tip to decrease possible complications.
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.