• 제목/요약/키워드: LTP

검색결과 125건 처리시간 0.036초

No-Touch vs. Conventional Radiofrequency Ablation Using Twin Internally Cooled Wet Electrodes for Small Hepatocellular Carcinomas: A Randomized Prospective Comparative Study

  • Yun Seok Suh;Jae Won Choi;Jeong Hee Yoon;Dong Ho Lee;Yoon Jun Kim;Jeong Hoon Lee;Su Jong Yu;Eun Ju Cho;Jung Hwan Yoon;Jeong Min Lee
    • Korean Journal of Radiology
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    • 제22권12호
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    • pp.1974-1984
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    • 2021
  • Objective: This study aimed to compare the efficacy between no-touch (NT) radiofrequency ablation (RFA) and conventional RFA using twin internally cooled wet (TICW) electrodes in the bipolar mode for the treatment of small hepatocellular carcinomas (HCC). Materials and Methods: In this single-center, two-arm, parallel-group, prospective randomized controlled study, we performed a 1:1 random allocation of eligible patients with HCCs to receive NT-RFA or conventional RFA between October 2016 and September 2018. The primary endpoint was the cumulative local tumor progression (LTP) rate after RFA. Secondary endpoints included technical conversion rates of NT-RFA, intrahepatic distance recurrence, extrahepatic metastasis, technical parameters, technical efficacy, and rates of complications. Cumulative LTP rates were analyzed using Kaplan-Meier analysis and the Cox proportional hazard regression model. Considering conversion cases from NT-RFA to conventional RFA, intention-to-treat and as-treated analyses were performed. Results: Enrolled patients were randomly assigned to the NT-RFA group (37 patients with 38 HCCs) or the conventional RFA group (36 patients with 38 HCCs). Among the NT-RFA group patients, conversion to conventional RFA occurred in four patients (10.8%, 4/37). According to intention-to-treat analysis, both 1- and 3-year cumulative LTP rates were 5.6%, in the NT-RFA group, and they were 11.8% and 21.3%, respectively, in the conventional RFA group (p = 0.073, log-rank). In the as-treated analysis, LTP rates at 1 year and 3 years were 0% and 0%, respectively, in the NT-RFA group sand 15.6% and 24.5%, respectively, in the conventional RFA group (p = 0.004, log-rank). In as-treated analysis using multivariable Cox regression analysis, RFA type was the only significant predictive factor for LTP (hazard ratio = 0.061 with conventional RFA as the reference, 95% confidence interval = 0.000-0.497; p = 0.004). There were no significant differences in the procedure characteristics between the two groups. No procedure-related deaths or major complications were observed. Conclusion: NT-RFA using TICW electrodes in bipolar mode demonstrated significantly lower cumulative LTP rates than conventional RFA for small HCCs, which warrants a larger study for further confirmation.

Immediate Effects of Upper Trapezius Stretching in More and Less Tensed Positions on the Range of Neck Rotation in Patients With Unilateral Neck Pain

  • Park, Kyue-Nam;Ha, Sung-Min;Kim, Si-Hyun;Kwon, Oh-Yun
    • 한국전문물리치료학회지
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    • 제20권1호
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    • pp.47-54
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    • 2013
  • The purpose of this study was to compare the immediate effects of upper trapezius muscle stretching in more tensed position (MTP) and less tensed position (LTP) on the change of range of motion (ROM) for neck rotation, and the ROM for conjunct neck motions at end-range of neck rotation toward the painful side in patients with unilateral neck pain. Eighteen patients with unilateral neck pain were recruited for the study's MTP group, and 18 age-, weight- and gender-matched patients with unilateral neck pain were recruited for LTP group. The ROM changes in active neck primary and conjunct motions were measured using a cervical ROM inclinometer in the sitting position. Our results showed that both upper trapezius stretching method in MTP and LTP were significantly effective in increasing the ROM of neck rotation toward painful side in patients with unilateral neck pain. However, a significantly greater increase in the ROM for neck rotation and a further decrease in conjunct neck extension during neck rotation toward the painful side were shown in MTP group, compared to LTP group. The upper trapezius stretching in MTP is useful in increasing the ROM of neck rotation and decreasing the range of conjunct neck extension during neck rotation toward the painful side in patients with unilateral neck pain.

Enhancement of GluN2B Subunit-Containing NMDA Receptor Underlies Serotonergic Regulation of Long-Term Potentiation after Critical Period in the Rat Visual Cortex

  • Joo, Kayoung;Rhie, Duck-Joo;Jang, Hyun-Jong
    • The Korean Journal of Physiology and Pharmacology
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    • 제19권6호
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    • pp.523-531
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    • 2015
  • Serotonin [5-hydroxytryptamine (5-HT)] regulates synaptic plasticity in the visual cortex. Although the effects of 5-HT on plasticity showed huge diversity depending on the ages of animals and species, it has been unclear how 5-HT can show such diverse effects. In the rat visual cortex, 5-HT suppressed long-term potentiation (LTP) at 5 weeks but enhanced LTP at 8 weeks. We speculated that this difference may originate from differential regulation of neurotransmission by 5-HT between the age groups. Thus, we investigated the effects of 5-HT on apha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-, ${\gamma}$-aminobutyric acid receptor type A (GABAAR)-, and N-methyl-D-aspartic acid receptor (NMDAR)-mediated neurotransmissions and their involvement in the differential regulation of plasticity between 5 and 8 weeks. AMPAR-mediated currents were not affected by 5-HT at both 5 and 8 weeks. GABAAR-mediated currents were enhanced by 5-HT at both age groups. However, 5-HT enhanced NMDAR-mediated currents only at 8 weeks. The enhancement of NMDAR-mediated currents appeared to be mediated by the enhanced function of GluN2B subunit-containing NMDAR. The enhanced GABAAR- and NMDAR-mediated neurotransmissions were responsible for the suppression of LTP at 5 weeks and the facilitation of LTP at 8 weeks, respectively. These results indicate that the effects of 5-HT on neurotransmission change with development, and the changes may underlie the differential regulation of synaptic plasticity between different age groups. Thus, the developmental changes in 5-HT function should be carefully considered while investigating the 5-HT-mediated metaplastic control of the cortical network.

Comparison of Combined Therapy Using Conventional Chemoembolization and Radiofrequency Ablation Versus Conventional Chemoembolization for Ultrasound-Invisible Early-Stage Hepatocellular Carcinoma (Barcelona Clinic Liver Cancer Stage 0 or A)

  • Lee, Hyukjoon;Yoon, Chang Jin;Seong, Nak Jong;Jeong, Sook-Hyang;Kim, Jin-Wook
    • Korean Journal of Radiology
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    • 제19권6호
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    • pp.1130-1139
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    • 2018
  • Objective: To compare the therapeutic efficacy between conventional transarterial chemoembolization (cTACE) and combined therapy using cTACE and radiofrequency ablation (RFA) in ultrasound (US)-invisible early stage hepatocellular carcinoma (HCC). Materials and Methods: From January 2008 to June 2016, 167 patients with US-invisible early stage HCCs were treated with cTACE alone (cTACE group; n = 85) or cTACE followed by immediate fluoroscopy-guided RFA targeting intratumoral iodized oil retention (combined group; n = 82). Procedure-related complications, local tumor progression (LTP), time to progression (TTP), and overall survival (OS) were compared between the two groups. Multivariate analyses were performed to identify prognostic factors. Results: There was no major complication in either group. The cTACE group showed higher 1-, 3-, and 5-year LTP rates than the combined group; i.e., 12.5%, 31.7%, and 37.0%, respectively, in the cTACE group; compared to 7.3%, 16.5%, and 16.5%, respectively, in the combined group; p = 0.013. The median TTP was 18 months in the cTACE group and 24 months in the combined group (p = 0.037). Cumulative 1-, 3-, and 5-year OS rates were 100%, 93.2%, and 87.7%, respectively, in the cTACE group and 100%, 96.6%, and 87.4%, respectively, in the combined group (p = 0.686). Tumor diameter > 20 mm and cTACE monotherapy were independent risk factors for LTP and TTP. Conclusion: Combined therapy using cTACE followed by fluoroscopy-guided RFA is a safe and effective treatment in US-invisible early stage HCCs. It provides less LTP and longer TTP than cTACE alone.

Prediction of Local Tumor Progression after Radiofrequency Ablation (RFA) of Hepatocellular Carcinoma by Assessment of Ablative Margin Using Pre-RFA MRI and Post-RFA CT Registration

  • Yoon, Jeong Hee;Lee, Jeong Min;Klotz, Ernst;Woo, Hyunsik;Yu, Mi Hye;Joo, Ijin;Lee, Eun Sun;Han, Joon Koo
    • Korean Journal of Radiology
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    • 제19권6호
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    • pp.1053-1065
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    • 2018
  • Objective: To evaluate the clinical impact of using registration software for ablative margin assessment on pre-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) and post-RFA computed tomography (CT) compared with the conventional side-by-side MR-CT visual comparison. Materials and Methods: In this Institutional Review Board-approved prospective study, 68 patients with 88 hepatocellulcar carcinomas (HCCs) who had undergone pre-RFA MRI were enrolled. Informed consent was obtained from all patients. Pre-RFA MRI and post-RFA CT images were analyzed to evaluate the presence of a sufficient safety margin (${\geq}3mm$) in two separate sessions using either side-by-side visual comparison or non-rigid registration software. Patients with an insufficient ablative margin on either one or both methods underwent additional treatment depending on the technical feasibility and patient's condition. Then, ablative margins were re-assessed using both methods. Local tumor progression (LTP) rates were compared between the sufficient and insufficient margin groups in each method. Results: The two methods showed 14.8% (13/88) discordance in estimating sufficient ablative margins. On registration software-assisted inspection, patients with insufficient ablative margins showed a significantly higher 5-year LTP rate than those with sufficient ablative margins (66.7% vs. 27.0%, p = 0.004). However, classification by visual inspection alone did not reveal a significant difference in 5-year LTP between the two groups (28.6% vs. 30.5%, p = 0.79). Conclusion: Registration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-RFA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA.

Spinosin Attenuates Alzheimer's Disease-Associated Synaptic Dysfunction via Regulation of Plasmin Activity

  • Cai, Mudan;Jung, Inho;Kwon, Huiyoung;Cho, Eunbi;Jeon, Jieun;Yun, Jeanho;Lee, Young Choon;Kim, Dong Hyun;Ryu, Jong Hoon
    • Biomolecules & Therapeutics
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    • 제28권2호
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    • pp.131-136
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    • 2020
  • Hippocampal synaptic dysfunction is a hallmark of Alzheimer's disease (AD). Many agents regulating hippocampal synaptic plasticity show an ameliorative effect on AD pathology, making them potential candidates for AD therapy. In the present study, we investigated spinosin as a regulating agent of synaptic plasticity in AD. Spinosin attenuated amyloid β (Aβ)-induced long-term potentiation (LTP) impairment, and improved plasmin activity and protein level in the hippocampi of 5XFAD mice, a transgenic AD mouse model. Moreover, the effect of spinosin on hippocampal LTP in 5XFAD mice was prevented by 6-aminocaproic acid, a plasmin inhibitor. These results suggest that spinosin improves synaptic function in the AD hippocampus by regulating plasmin activity.

디지털 이동통신을 위한 음성 부호기의 성능 분석 (A Performance Analysis of the Speech Coders for Digital Mobile Radio)

  • 정영모;이상욱
    • 대한전자공학회논문지
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    • 제27권4호
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    • pp.491-501
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    • 1990
  • Recently, four speech coding techniques, namely, SBC-APCM(sub-band coding adaptive PCM), RPE-LPC(regualr pulse excitation linear predictive codec), MPE-LTP(multi-pulse excited long-term prediction) and CELP (code-excited linear prediction) are proposed for digital mobile radio applications. However, a performance comparison of these coders in the Rayleigh fading environment has not been made yet. In this paper, the performances of the four spech coders in the random bit error and burst error environment are investigated. For the channel coding of SBC-APCM, RPE-LPC and MPE-LTP, the sensitivity of output bit stream is measured and a bit selective forward error correction is provided acording to the measured bit sensitivity. And for an attempt to improve the performance of CELP, an optimum quantizer is applied for transmitting scalar quantities in CELP. However, an improvement over the conventional approach is found to be negligible. For the channel coding of CELP, Reed-Solomon code, Golay code, convolutional code of rate 1/2 shows the best performance. Finally, from the simulation results, it is concluded that CELP is the best candidate for digital mobile radio and is followed by MPE-LTP, SBC-APCM and RPE-LPC.

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흰쥐 해마 CA1 영역에서 H2O2에 의한 장기강화 억제에 대한 발효황금 추출물의 효과 (Effects of Fermented Scutellaria Baicalensis Extract on H2O2 - Induced Impairment of Long-term Potentiation in Hippocampal CA1 Area of Rats)

  • 허준호;;김민선
    • 동의생리병리학회지
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    • 제33권6호
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    • pp.356-362
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    • 2019
  • Scutellaria baicalensis (SB) has widely used in the treatment for various brain diseases in the field of Oriental medicine. Biofermantation of SB can make major chemical constituents of SB to pass blood-brain barrier easily and to have more potent anti-oxidant ability. There is a little information about the contribution of fermented SB (FSB) to the formation or maintenance of the neural plasticity in the hippocampus. The purpose of this study was to evaluate effects of FSB extract on hydrogen peroxide (H2O2) - induced impairments of the induction and maintenance of long-term potentiation (LTP), an electrophysiological marker for the neural plasticity in the hippocampus. From hippocampal slices of rats, the field excitatory postsynaptic potentials (fEPSPs) were evoked by the electrical stimulation to the Schaffer collaterals - commissural fibers in the CA1 areas and LTP by theta-burst stimulation by using 64 - channels in vitro multi-extracellular recording system. In order to induce oxidative stress to hippocampal slices two different concentrations (200, 400 μM) of H2O2 were given to the perfused aCSF before and after the LTP induction, respectively. The ethanol extract of FBS with concentration of 25 ㎍/ml, 50 ㎍/ml was diluted in perfused aCSF that had 200 μM H2O2, respectively. Oxidative stress by the treatment of H2O2 resulted in decrease of the induction rate of LTP in the CA1 area with a dose - dependent manner. However, the ethanol extract of FSB prevented the reduction of the induction rate of LTP caused by H2O2 - induced oxidative stress with a dose - dependent manner. These results may support a potential application of FSB to ameliorate impairments of hippocampal dependent neural plasticity or memory caused by oxidative stress.

대장균 배양 중 phe W$^+$-pheS-$^{-ts}$ System에 의한 재조합 trp$^+$ 플라스미드의 안정적 유지 (Stable Maintenance of Recombinant Plasmid Containing trp $^+$ Operon in E. coli Cultures by the phe W$^+$ -pheS$^{t8}$ System)

  • 강충민;최장원;이세영
    • 한국미생물·생명공학회지
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    • 제18권1호
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    • pp.89-93
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    • 1990
  • 재조합 pBR322-trp$^+$ 플라스미드의 숙주내 안정적 유지를 목적으로 tRNA phe 의 구조유전자인 pheW$^+$ 유전자를 pBR322-trp$^+$의 플라스미드에 도입시키고, 숙주세포로는 트립토판 생산을 위한 정상숙주 LC901의 phenylalanyl tRNA synthetase 온도감수성 변이체인 LC901-pheS-ts를 구성하여 이 온도감수성 숙주의 제한온도 (restrictive temperature)에서 재조합 trp$^+$ 플라스미드의 안정적 유지와 trp$^+$ 유전자가 미치는 효과를 조사하였다.

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결명자 에탄올 추출물이 알코올로 유도로 유도한 기억 장애에 미치는 영향 (Effect of an Ethanol Extract of Cassia obtusifolia Seeds on Alcohol-induced Memory Impairment)

  • 권희영;조은비;전지은;이영춘;김동현
    • 생명과학회지
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    • 제29권5호
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    • pp.564-569
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    • 2019
  • 최근 알코올 소비량이 증가함에 따라 과량의 에탄올을 섭취하는 경우 또한 늘어나고 있다. 이런 과도한 에탄올 섭취는 ${\gamma}$-aminobutyric acid (GABA) 수용체의 활성화와 glutamate 수용체의 활성 억제를 통해 신경계를 교란시켜 단기 기억 형성을 방해 한다. 알코올에 의한 인지기능의 저하는 알코올성 black out을 유도할 수 있으며, 반복될 경우 알코올성 치매로 이어질 수 있기 때문에 black out을 예방하는 치료제의 개발이 필요하다. 따라서 본 연구자는 해당 연구를 통하여 Cassia obtusifolia seeds 에탄올 추출물(COE)이 가진 black out 예방제로써의 가능성을 평가하였다. 본 연구에서는 에탄올에 의해 유도된 기억 장애에 대한 COE의 효과를 확인하였다. 실험 동물의 기억력을 측정하기 위하여 수동 회피 실험과 Y자 미로 실험을 수행하였고, 마우스 해마 절편을 사용하여 에탄올이 기억의 형성과 관련하여 장기 강화(long term potentiation; LTP)에 어떠한 영향을 끼치는지 전기생리학을 통해 확인하였다. 또한 ${\alpha}$-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid 수용체 길항제인 NBQX ($50{\mu}M$)를 사용하여 에탄올에 의한 인지기능 장애와 관련이 있다고 알려진 N-Methyl-D-aspartate (NMDA) 매개 field 흥분성 시냅스 후 전위를 측정하였다. 결과적으로, COE는 에탄올에 의한 기억력의 손상을 방지하였고, 해마 절편에서 에탄올에 의해 감소된 LTP와 NMDA 매개 흥분성 시냅스 후 전위를 대조군과 비슷한 수준까지 회복시켰다.