• 한국임상수의학회지
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• 제40권6호
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• pp.414-422
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• 2023

Hearing assessment is critical in dogs and cats. Hearing loss in dogs and cats may be congenital or secondary to a central nervous system disorder or ear disease. The brainstem auditory-evoked response (BAER) test has been developed as an electrophysiological test for auditory function assessment. Modern BAER equipment is based on a computerized system. Thus, auditory function assessment can be performed using this objective, safe, and noninvasive method. No study has yet investigated the interspecies differences between BAER test results of dogs and cats. Therefore, the present study aimed to analyze the differences in BAER test results between dogs and cats. The test was conducted on four healthy adult dogs and four healthy adult cats. Regarding latency, lower values were obtained for all waveforms above 50 dB in cats compared to dogs. Regarding amplitude, cats showed higher values than dogs at intensities above 50 dB. Through a comparative analysis in this study, it was concluded that the two species had statistically significant differences. The BAER data of dogs cannot be applied to cats, and vice versa.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권4호
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• pp.679-700
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• 1996

Inferior alveolar nerve dysfunction may be the result of trauma, disease, or iatrogenic injury. Inferior alveolar nerve injury is inherent risk in endodontic therapy, orthognathic surgery of the mandible, and extraction of mandibular teeth, particularly the third molars. The sensory disturbances of inferior alveolar nerve associated with such injury have been well documented clinical problem that is commonly evaluated by several clinical sensory test including Tinels sign, Von Frey test(static light touch detection), directional discrimination, two-point discrimination, pin pressure nociceptive discrimination, and thermal test. These methods used to detect and assess inferior alveolar nerve injury have been subjective in nature, relying on the cooperation of the patients. In addition, many of these techniques are sensitive to differences in the examiners experience and skill with the particular technique. Data obtained at different times or by different examiners are therefore difficult to compare. Prior experimental studies have used electro diagnostic methods(sensory evoked potential) to objectively evaluate inferior alveolar nerve after nerve injury. This study was designed with inferior alveolar nerve of rabbit. Several types of injury including mind, moderate, severe compression and perforation with 19 gauze, 21 gauze needle and 6mm, 10mm traction were applied for taking the sesory evoked ppterntial. Latency and amplitude of injury rabbit inferior alveolar nerve were investigated with sensory evoked potential using unpaired t-test. The results were as follows : 1. Intensity of threshold (T1) was $128{\pm}16{\mu}A$ : latency, $0.87{\pm}0.07$ microsecond : amplitude, $0.4{\pm}0.1{\mu}V$ : conduction velocity, 23.3 m/s in sensory evoked potential of uninjured rabbit inferior alveolar nerve. 2. Rabbit inferior alveolar nerve consists of type II and III sensory nerve fiber. 3. Latency was increased and amplitude was decreased in compression injury. The more injured, the more changed in latency and amplitude. 4. Findings in perforation injury was similar to compression injury. Waveform for sensory evoked potential improved by increasing postinjured time. 5. Increasing latency was prominent in traction injury rabbit inferior alveolar nerve. 6. In microscopic histopathological findings, significant degeneration and disorganization of the internal architecture were seen in nerve facicle of severe compression and 10mm traction group. From the above findings, electrophysiological assessment(sensory evoked potential) of rabbit injured inferior alveolar nerve is reliable technique in diagnosis and prognosis of nerve injury.

• International Journal of Stem Cells
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• 제16권3호
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• pp.281-292
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• 2023

Background and Objectives: Human induced pluripotent stem cell (hiPSC)-derived cardiomyocyte (CM) hold great promise as a cellular source of CM for cardiac function restoration in ischemic heart disease. However, the use of animal-derived xenogeneic substances during the biomanufacturing of hiPSC-CM can induce inadvertent immune responses or chronic inflammation, followed by tumorigenicity. In this study, we aimed to reveal the effects of xenogeneic substances on the functional properties and potential immunogenicity of hiPSC-CM during differentiation, demonstrating the quality and safety of hiPSC-based cell therapy. Methods and Results: We successfully generated hiPSC-CM in the presence and absence of xenogeneic substances (xeno-containing (XC) and xeno-free (XF) conditions, respectively), and compared their characteristics, including the contractile functions and glycan profiles. Compared to XC-hiPSC-CM, XF-hiPSC-CM showed early onset of myocyte contractile beating and maturation, with a high expression of cardiac lineage-specific genes (ACTC1, TNNT2, and RYR2) by using MEA and RT-qPCR. We quantified N-glycolylneuraminic acid (Neu5Gc), a xenogeneic sialic acid, in hiPSC-CM using an indirect enzyme-linked immunosorbent assay and liquid chromatography-multiple reaction monitoring-mass spectrometry. Neu5Gc was incorporated into the glycans of hiPSC-CM during xeno-containing differentiation, whereas it was barely detected in XF-hiPSC-CM. Conclusions: To the best of our knowledge, this is the first study to show that the electrophysiological function and glycan profiles of hiPSC-CM can be affected by the presence of xenogeneic substances during their differentiation and maturation. To ensure quality control and safety in hiPSC-based cell therapy, xenogeneic substances should be excluded from the biomanufacturing process.

• 대한한의진단학회지
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• 제9권1호
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• pp.131-135
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• 2005

Background and purpose: The measurement of direct current (DC) potential on skin area of meridian has recently been adopted to explore the electrophysiological characteristics of meridian system, But there exists two problems to be explained; the entity of the DC potential to be measured and the characteristics of electrode gel interface of measurement system, It is not clear whether the DC potential reflect, at least hypothetically, the entity of meridian, and if there exist any unstable factor in the DC potential measurement system. Methods: In this study, we designed an electronic circuit model of skin and applied known DC potential sources $({\pm}10.75mV,\;0mV)$ to the electrode interface of the skin model. Results: The result showed that the measured DC potential changed according to the time, and the same phenomenon was observed when the electrode gel was replaced with an electric condenser. It is suggested that the measurement of DC potential on electrode gel interface is very difficult and produces unstable values due to the capacity effect of electrode gel. Conclusion: Further studies on the DC potential evaluation in the context of meridian study should consider and bypass this problem.

• 대한불안의학회지
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• 제6권1호
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• pp.31-36
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• 2010

Objective : Mismatch negativity (MMN) provides an electrophysiological index of an involuntary attention switching process. This study investigated MMN anomalies and their relationship to clinical variables in patients with obsessive-compulsive disorder (OCD). Methods : Study participants were 29 OCD patients and 24 normal controls. We used a 128-channel EEG to measure MMN during a passive oddball paradigm. Then we assessed the correlations between MMN amplitudes and clinical measures. Results : The OCD patients exhibited significantly greater MMN amplitude compared to the controls. Also, the right frontal lobe MMN amplitudes correlated significantly to the OCD patients' Yale-Brown Obsessive Compulsive Scale total scores (r=-0.520, p=0.005). Conclusion : These results suggest that MMN anomalies in OCD patients reflect a monitoring circuit dysfunction, raising the possibility that the OCD's pathophysiology includes glutamatergic dysfunction.

• Journal of Genetic Medicine
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• 제17권2호
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• pp.89-91
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• 2020

Charcot-Marie-Tooth (CMT) disease can be divided mainly into demyelination and axonopathy based on the results of the electrophysiological study. Mitofusin 2, encoded by MFN2 gene, has a crucial role in the fusion of mitochondria, which is known to associate with CMT type 2A as one of the axonal forms. We describe a 44-year-old man with progressive weakness on bilateral legs after noticing foot drop in his early teen. When we examined him at 45 years of age, he presented atrophy on entire legs and with distal muscle weakness on limbs. The nerve conduction study revealed severely decreased amplitude on motor nerve ranging from 0.2 to 4.5 mV, while conduction velocity remained more than 30.4 m/s. The whole-exome sequencing revealed a novel variant c.2228G>T in MFN2 by efficient genetic analysis tool, MutationDistiller. This report will not only expand the mutation spectrum of CMT2A but also introduce a time-saving genetic analysis tool.

• 한국임상수의학회지
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• 제40권4호
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• pp.260-267
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• 2023

Specialized hearing tests for pets are currently in demand. A brainstem auditory evoked response (BAER) test is an objective, non-invasive, and practical electrophysiological method that records electric signals from the peripheral auditory system to the brainstem when an auditory stimulation is provided. In veterinary medicine, sedation or anesthesia is essential for a successful examination. In human medicine, research has established the indications for various sedatives, anesthetics, and drugs according to the depth of anesthesia required. However, in veterinary medicine, there are very few comparative studies on propofol or isoflurane, which are the most common anesthetics used. Therefore, the present study aimed to analyze the difference in BAER test results between sedation with medetomidine, anesthesia using propofol, and inhalation anesthesia with isoflurane after propofol administration. The test was conducted on four healthy adult dogs. There was no statistically significant difference in latency, interpeak latency, or amplitude between the various drugs. The results suggest that a sedative or anesthetic for the administration of a BAER test can be selected according to the patient's needs.

• 생명과학회지
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• 제16권1호
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• pp.114-119
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• 2006

저출력 적외선 레이저가 손상된 말초신경의 재생에 미치는 영향을 알아보기 위하여 흰쥐의 양측 좌골신경에 압궤손상을 준 뒤, 레이저 조사 기간에 따라 1, 3, 5 및 7주군으로 나누어 손상된 좌골신경의 신경전도속도와 진폭을 측정하여 신경재생의 정도를 관찰한 결과는 다음과 같았다. 좌골신경전도속도 검사에서 압궤손상 유발후에 손상전보다 유의하게 전도속도가 지연되었으나, 레이저를 조사한 실험측은 치료후 3주에 현저하게 신경전도 속도가 증가하였다. 좌골신경 진폭 검사에서 압궤손상 유발후에 손상전보다 유의하게 진폭이 감소하였으나, 레이저를 조사한 실험측은 치료후 3주에 복합근 활동전위의 진폭이 유의하게 증가하였다. 이상의 결과로 보아, 저출력 레이저 조사는 손상된 좌골신경의 기능회복에 있어, 주로 손상 초기의 회복속도에 영향을 주는 것으로 생각되는 바, 향후 말초신경 손상의 재활치료에 고려해야 할 것으로 생각된다.

• The Korean Journal of Physiology and Pharmacology
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• 제5권1호
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• pp.71-78
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• 2001

Capsaicin, a pungent ingredient of hot pepper, elicits an intense burning pain when applied cutaneously and intradermally. Activation of capsaicin-gated channel in C-type dorsal root ganglion (DRG) neurons produces nonselective cationic currents. Although electrophysiological and biochemical properties of capsaicin-activated current $(I_{CAP})$ were studied, the regulatory mechanism and intracellular signaling pathway are still unclear. In the present study, we investigated the modulations of $I_{CAP}$ by DAMGO $({\mu}-opioid\;agonist)$ and cholecystokinin octapeptide (CCK-8). In 18 out of 86 cells, the amplitude of $I_{CAP}$ was significantly increased by DAMGO and completely reversed after washout, while $I_{CAP}$ was decreased by DAMGO in 25 cells. In 43 cells, DAMGO had no effect on $I_{CAP}$. Mean action potential duration was significantly different between 'increased-by-DAMGO' group and 'decreased-by-DAMGO' group. Mean amplitudes of $I_H$ were not significantly different between both groups. CCK-8 reversibly enhanced the amplitude of $I_{CAP}$ (5/13). DAMGO also increased $I_{CAP}$ amplitude significantly in the same cells. The amplitude of $I_{CAP}$ was increased in additive manner by combined applications of DAMGO and CCK-8 in these cells. These results suggest that DAMGO and CCK-8 can either increase or decrease $I_{CAP}$ presumably depending on the subtypes of DRG cells and classified by electrophysiological properties.

• 대한의용생체공학회:의공학회지
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• 제43권1호
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• pp.19-26
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• 2022

The Comprehensive in vitro Proarrhythmic Assay(CiPA) project was launched for solving the hERG assay problem of being classified as high-risk groups even though they are low-risk drugs due to their high sensitivity. CiPA presented a protocol to predict drug toxicity using physiological data calculated based on the in-silico model. in this study, features calculated through the in-silico model are analyzed for correlation of changing action potential in the near future, and features are verified through predictive performance according to drug datasets. Using the O'Hara Rudy model modified by Dutta et al., Pearson correlation analysis was performed between 13 features(dVm/dtmax, APpeak, APresting, APD90, APD50, APDtri, Ca_peak, Ca_resting, CaD90, CaD50, CaDtri, qNet, qInward) calculated at 100 pacing, and between dVm/d_{tmax_repol} calculated at 1,000 pacing, and linear regression analysis was performed on each of the 12 training drugs, 16 verification drugs, and 28 drugs. Indicators showing high coefficient of determination(R²) in the training drug dataset were qNet 0.93, AP resting 0.83, APDtri 0.78, Ca resting 0.76, dVm/dt_max 0.63, and APD90 0.61. The indicators showing high determinants in the validated drug dataset were APDtri 0.94, APD90 0.92, APD50 0.85, CaD50 0.84, qNet 0.76, and CaD90 0.64. Indicators with high coefficients of determination for all 28 drugs are qNet 0.78, APD90 0.74, and qInward 0.59. The indicators vary in predictive performance depending on the drug dataset, and qNet showed the same high performance of 0.7 or more on the training drug dataset, the verified drug dataset, and the entire drug dataset.