• Title/Summary/Keyword: Threshold animal model

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Glottic Closure Reflex in an Anesthetized and Awake Canine Model (개의 성문폐쇄반사에 미치는 중추조절의 영향에 관한 연구)

  • 강주완;김광문;김영호
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.14 no.2
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    • pp.83-87
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    • 2003
  • Background and Objectives : Sphincteric function of the larynx, essential to lower airway protection, is most efficiently achieved through strong reflex adduction by both vocal cords. We hypothesize that central facilitation is an essential component of a bilateral adductor reflex and that its disturbance could result in weakened sphincteric closure. Materials and Method : Seven adult 20kg dogs underwent evoked response laryngeal electromyoraphy under 0.5 to 1.0 MAC isoflurane anesthesia. The internal branch of superior laryngeal nerve was stimulated through bipolar platinum-iridium electrodes and recording electrodes were positioned in the ipsilateral and contralateral thyroaryteonoid muscles. Results : Consistent threshold responses were obtained ipsilaterally under all anesthetic levels. However, contralateral reflex responses disappeared as anesthetic levels approached 1.0 MAC. Additionally, at 0.5 MAC, late responses (R2) were detected in one animal. Conclusion : Alteration of central facilitation by deepening anesthesia abolishes the crossed adductor reflex, predisposing to a weakened glottic closure response. Precise understanding of this effect may improve the prevention of aspiration in patients emerging from prolonged sedation or under heavy psychotropic control.

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High Signal Intensities on T1-Weighted MRI as a Biomarker of Manganese

  • Kim, Yang-Ho
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2005.06a
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    • pp.105-139
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    • 2005
  • Increased signal in T1-weighted images was observed in the experimental manganese (Mn) poisoning of the non-human primate and a patient with Mn neurointoxication. However, our study showed that the increased signals in magnetic resonance images (MRI) were highly prevalent (41.6%) in Mn-exposed workers. Blood Mn concentration correlated with pallidal index. These changes in MRI tend to disappear following the withdrawal from the source of Mn accumulation, despite permanent neurological damage. Thus increased signal intensities on a T1-weighted image reflect exposure to Mn, but not necessarily manganism. Our study also showed that the concentration of Mn required to produce increased signal intensities on MRI is much lower than the threshold necessary to result in overt clinical signs of manganism. Increased signal intensities in the globus pallidus were determined by manganese accumulation in the animal experiment. Reanalysis of the previous data with the structural equation model revealed that pallidal index (Pl) on MRI reflects target organ dose of occupational Mn exposure

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The Effects of Dokhwalgisaeng-tang(Duhuoqisheng-tang ) and Jungsongouhyul Pharmacopuncture on Pain Control and Nerve Regeneration in the Crush-induced Sciatic Nerve Injury of the Rat Model (독활기생탕(獨活寄生湯) 및 중성어혈약침(中性瘀血藥鍼)이 좌골신경 압좌손상 백서의 통증과 신경 재생에 미치는 영향)

  • Lee, Sang-Gyu;Won, Jae-Kyun;Yeom, Seung-Ryong;Lee, Su-Kyung;Song, Yung-Sun;Kwon, Young-Dal
    • Journal of Korean Medicine Rehabilitation
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    • v.19 no.3
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    • pp.15-32
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    • 2009
  • Objectives : The purpose of this Study was to identify the effect of Dokhwalgisaeng-tang(Duhuoqisheng-tang) and Jungsongouhyul pharmacopuncture on pain control and nerve regeneration after crush injury in rat sciatic nerve. Methods : Neuropathic pain was induced by crush-induced model of right sciatic nerve. Animal groups were divided as follows; Group I: no treatment control group, Group II : experimental group treated with Dokhwalgisaeng-tang(Duhuoqisheng-tang), Group III : experimental group treated with Jungsongouhyul pharmacopuncture, and Group IV : experimental group treated with Dokhwalgisaeng-tang(Duhuoqisheng-tang) and Jungsongouhyul pharmacopuncture. To evaluate pain intensity, each group was observed paw withdrawal threshold and immunoreactivity on the c-fos before and after respective treatments in five hours, first, third, and fifth day. To evaluate nerve regeneration, those were observed SFI(Sciatic Functional Index) and GAP-43(Growth Associated Protein 43) after each treatment in seventh and thirteenth day. Results : 1. Paw withdrawal threshold to the mechanical stimuli made the significant difference between group IV and the control group after five days of the experiment. 2. Paw withdrawal threshold to the thermal stimuli made the significant difference between group I and III, I and IV, II and IV. 3. In immunohistochemical response of c-fos, as time passes, the immunoreactivity of all groups was decreased gradually. Especially, group IV was observed the lowest after three days. 4. The differences of sciatic function indexes in each group were significantly between group I and III, I and IV, II and IV after 14 days, and between group I and III, I and IV, II and IV, III and IV after 21 days. 5. In immunohistochemical response of GAP-43, all groups had higher GAP-43 immunoreactivity at the 14 days from post-injury and group IV showed highest immunoreactivity. Conclusions : Based on above the results, it is proposed that Dokhwalgisaeng-tang(Duhuoqisheng-tang) and Jungsongouhyul pharmacopuncture may be helpful as a treatment in neuropathic pain and nerve regeneration in rat model.

Preclinical study of a novel ingestible bleeding sensor for upper gastrointestinal bleeding

  • Kimberly F. Schuster;Christopher C. Thompson;Marvin Ryou
    • Clinical Endoscopy
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    • v.57 no.1
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    • pp.73-81
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    • 2024
  • Background/Aims: Upper gastrointestinal bleeding (UGIB) is a life-threatening condition that necessitates early identification and intervention and is associated with substantial morbidity, mortality, and socioeconomic burden. However, several diagnostic challenges remain regarding risk stratification and the optimal timing of endoscopy. The PillSense System is a noninvasive device developed to detect blood in patients with UGIB in real time. This study aimed to assess the safety and performance characteristics of PillSense using a simulated bleeding model. Methods: A preclinical study was performed using an in vivo porcine model (14 animals). Fourteen PillSense capsules were endoscopically placed in the stomach and blood was injected into the stomach to simulate bleeding. The safety and sensitivity of blood detection and pill excretion were also investigated. Results: All the sensors successfully detected the presence or absence of blood. The minimum threshold was 9% blood concentration, with additional detection of increasing concentrations of up to 22.5% blood. All the sensors passed naturally through the gastrointestinal tract. Conclusions: This study demonstrated the ability of the PillSense System sensor to detect UGIB across a wide range of blood concentrations. This ingestible device detects UGIB in real time and has the potential to be an effective tool to supplement the current standard of care. These favorable results will be further investigated in future clinical studies.

A Whole Genome Association Study to Detect Single Nucleotide Polymorphisms for Carcass Traits in Hanwoo Populations

  • Lee, Y.-M.;Han, C.-M.;Li, Yi;Lee, J.-J.;Kim, L.H.;Kim, J.-H.;Kim, D.-I.;Lee, S.-S.;Park, B.-L.;Shin, H.-D.;Kim, K.-S.;Kim, N.-S.;Kim, Jong-Joo
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.4
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    • pp.417-424
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    • 2010
  • The purpose of this study was to detect significant SNPs for carcass quality traits using DNA chips of high SNP density in Hanwoo populations. Carcass data of two hundred and eighty nine steers sired by 30 Korean proven sires were collected from two regions; the Hanwoo Improvement Center of National Agricultural Cooperative Federation in Seosan, Chungnam province and the commercial farms in Gyeongbuk province. The steers in Seosan were born between spring and fall of 2006 and those in Gyeonbuk between falls of 2004 and 2005. The former steers were slaughtered at approximately 24 months, while the latter steers were fed six months longer before slaughter. Among the 55,074 SNPs in the Illumina bovine 50K chip, a total of 32,756 available SNPs were selected for whole genome association study. After adjusting for the effects of sire, region and slaughter age, phenotypes were regressed on each SNP using a simple linear regression model. For the significance threshold, 0.1% point-wise p value from F distribution was used for each SNP test. Among the significant SNPs for a trait, the best set of SNP markers were selected using a stepwise regression procedure, and inclusion and exclusion of each SNP out of the model was determined at the p<0.001 level. A total of 118 SNPs were detected; 15, 20, 22, 28, 20, and 13 SNPs for final weight before slaughter, carcass weight, backfat thickness, weight index, longissimus dorsi muscle area, and marbling score, respectively. Among the significant SNPs, the best set of 44 SNPs was determined by stepwise regression procedures with 7, 9, 6, 9, 7, and 6 SNPs for the respective traits. Each set of SNPs per trait explained 20-40% of phenotypic variance. The number of detected SNPs per trait was not great in whole genome association tests, suggesting additional phenotype and genotype data are required to get more power to detect the trait-related SNPs with high accuracy for estimation of the SNP effect. These SNP markers could be applied to commercial Hanwoo populations via marker-assisted selection to verify the SNP effects and to improve genetic potentials in successive generations of the Hanwoo populations.

The Effects of Transcutaneous Electrical Nerve Stimulation (TENS) on the Neuropathic Pain in Peripheral Nerve Injury (말초신경 손상에 의한 신경병증성 통증에 TENS가 미치는 효과)

  • Lee, Soon-Hyun;Song, Chang-Ho
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.1
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    • pp.79-89
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    • 2013
  • PURPOSE: To identify the effects of single trial transcutaneous electrical nerve stimulation (TENS) application on chronic neuropathic pain and the repeated TENS application to development of neuropathic pain following peripheral nerve injury. METHODS: First, 20 rats were given the median nerve ligation to induce chronic neuropathic pain. After the ligation, neuropathic pain was assessed by measuring the forepaws withdrawal threshold to von Frey filaments for 3 weeks. Afterward, rats were randomly divided into TENS group and placebo-TENS group. TENS (frequency 100Hz, pulse width $200{\mu}s$) was applied to the forearm for 20 minutes. Second, 34 rats were randomly allocated into two group after median nerve ligation: TENS group and placebo-TENS group. Both interventions were applied to the forearm for 20 minutes from 1 day to 3 weeks after injury. Neuropathic pain to mechanical was measured on each rat for 3 weeks. RESULTS: Exeprimental rats showed a clear neuropathic pain-like behaviors, such as reduced forepaw withdrawal threshold to mechanical stimulation for 3 weeks, after median nerve ligation. And, TENS decreased effectively the chronic neuropathic pain originated from median nerve injury. TENS also diminished the development of neuropathic pain after nerve injury. CONCLUSION: Our animal model studying for neuropathic pain following median nerve injury may be useful to investigate peripheral neuropathic pain in human. Also, TENS may be used to mediate chronic neuropathic pain and to prevent the development of neuropathic pain following median nerve injury.

Intravenous Administration of Substance P Attenuates Mechanical Allodynia Following Nerve Injury by Regulating Neuropathic Pain-Related Factors

  • Chung, Eunkyung;Yoon, Tae Gyoon;Kim, Sumin;Kang, Moonkyu;Kim, Hyun Jeong;Son, Youngsook
    • Biomolecules & Therapeutics
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    • v.25 no.3
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    • pp.259-265
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    • 2017
  • This study aimed to investigate the analgesic effect of substance P (SP) in an animal model of neuropathic pain. An experimental model of neuropathic pain, the chronic constriction injury (CCI) model, was established using ICR mice. An intravenous (i.v.) injection of SP (1 nmole/kg) was administered to the mice to examine the analgesic effects of systemic SP on neuropathic pain. Behavioral testing and immunostaining was performed following treatment of the CCI model with SP. SP attenuated mechanical allodynia in a time-dependent manner, beginning at 1 h following administration, peaking at 1 day post-injection, and decaying by 3 days post-injection. The second injection of SP also increased the threshold of mechanical allodynia, with the effects peaking on day 1 and decaying by day 3. A reduction in phospho-ERK and glial fibrillary acidic protein (GFAP) accompanied the attenuation of mechanical allodynia. We have shown for the first time that i.v. administration of substance P attenuated mechanical allodynia in the maintenance phase of neuropathic pain using von Frey's test, and simultaneously reduced levels of phospho-ERK and GFAP, which are representative biochemical markers of neuropathic pain. Importantly, glial cells in the dorsal horn of the spinal cord (L4-L5) of SP-treated CCI mice, expressed the anti-inflammatory cytokine, IL-10, which was not seen in vehicle saline-treated mice. Thus, i.v. administration of substance P may be beneficial for improving the treatment of patients with neuropathic pain, since it decreases the activity of nociceptive factors and increases the expression of anti-nociceptive factors.

Genome-wide association study identifies 22 new loci for body dimension and body weight traits in a White Duroc×Erhualian F2 intercross population

  • Ji, Jiuxiu;Zhou, Lisheng;Guo, Yuanmei;Huang, Lusheng;Ma, Junwu
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.8
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    • pp.1066-1073
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    • 2017
  • Objective: Growth-related traits are important economic traits in the swine industry. However, the genetic mechanism of growth-related traits is little known. The aim of this study was to screen the candidate genes and molecular markers associated with body dimension and body weight traits in pigs. Methods: A genome-wide association study (GWAS) on body dimension and body weight traits was performed in a White $Duroc{\times}Erhualian$ $F_2$ intercross by the illumina PorcineSNP60K Beadchip. A mixed linear model was used to assess the association between single nucleotide polymorphisms (SNPs) and the phenotypes. Results: In total, 611 and 79 SNPs were identified significantly associated with body dimension traits and body weight respectively. All SNPs but 62 were located into 23 genomic regions (quantitative trait loci, QTLs) on 14 autosomal and X chromosomes in Sus scrofa Build 10.2 assembly. Out of the 23 QTLs with the suggestive significance level ($5{\times}10^{-4}$), three QTLs exceeded the genome-wide significance threshold ($1.15{\times}10^{-6}$). Except the one on Sus scrofa chromosome (SSC) 7 which was reported previously all the QTLs are novel. In addition, we identified 5 promising candidate genes, including cell division cycle 7 for abdominal circumference, pleiomorphic adenoma gene 1 and neuropeptides B/W receptor 1 for both body weight and cannon bone circumference on SSC4, phosphoenolpyruvate carboxykinase 1, and bone morphogenetic protein 7 for hip circumference on SSC17. Conclusion: The results have not only demonstrated a number of potential genes/loci associated with the growth-related traits in pigs, but also laid a foundation for studying the genes' role and further identifying causative variants underlying these loci.

The Effect of ATP-sensitive Potassium Channel on R-PIA Induced Mechanical Antiallodynia in a Peripheral Neuropathic Rat (신경병증 통증 모델의 백서에서 R-PIA의 기계적 항이질통 효과와 ATP-감수성 칼륨 통로와의 연관성에 대한 연구)

  • Min, Hong Gi;Seong, Seung Hye;Jung, Sung Mun;Shin, Jin Woo;Gwak, Mi Jung;Leem, Jeong Gill;Lee, Cheong
    • The Korean Journal of Pain
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    • v.18 no.2
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    • pp.107-112
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    • 2005
  • Background: Nerve ligation injury may produce mechanical allodynia, but this can be reversed after an intrathecal administration of adenosine analogues. In many animal and human studies, ATP-sensitive potassium channel blockers have been known to reverse the antinociceptive effect of various drugs. This study was performed to evaluate the mechanical antiallodynic effects of spinal R-PIA (Adenosine A1 receptor agonist) and the reversal of these effects due to pretreatment with glibenclamide (ATP-sensitive potassium channel blocker). Thus, the relationship between the antiallodynic effects of R-PIA and ATP-sensitive potassium channel were investigated in a neuropathic model. Methods: Male Sprague Dawley rats were prepared by tightly ligating the left lumbar 5th and 6th spinal nerves and implantation of a chronic lumbar intrathecal catheter for drug administration. The mechanical allodynia was measured by applying von Frey filaments ipsilateral to the lesioned hind paw. And the thresholds for paw withdrawal assessed. In study 1, either R-PIA (0.5, 1 and $2{\mu}g$) or saline were administered intrathecally for the examination of the antiallodynic effect of R-PIA. In study 2, glibenclamide (2, 5, 10 and 20 nM) was administered intrathecally 5 min prior to an R-PIA injection for investigation of the reversal of the antiallodynic effects of R-PIA. Results: The antiallodynic effect of R-PIA was produced in a dose dependent manner. In study 1, the paw withdrawal threshold was significantly increased with $2{\mu}g$ R-PIA (P < 0.05). In study 2, the paw withdrawal threshold with $2{\mu}g$ R-PIA was significantly decreased almost dose dependently by intrathecal pretreatment of 5, 10 and 20 nM glibenclamide (P < 0.05). Conclusions: These results demonstrated that an intrathecal injection of ATP-sensitive potassium channel blockers prior to an intrathecal injection of adenosine A1 receptors agonist had an antagonistic effect on R-PIA induced antiallodynia. The results suggest that the mechanism of mechanical antiallodynia, as induced by an intrathecal injection of R-PIA, may involve the ATP-sensitive potassium channel at both the spinal and supraspinal level in a rat nerve ligation injury model.

Contrast Media in Abdominal Computed Tomography: Optimization of Delivery Methods

  • Joon Koo Han;Byung Ihn Choi;Ah Young Kim;Soo Jung Kim
    • Korean Journal of Radiology
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    • v.2 no.1
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    • pp.28-36
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    • 2001
  • Objective: To provide a systematic overview of the effects of various parameters on contrast enhancement within the same population, an animal experiment as well as a computer-aided simulation study was performed. Materials and Methods: In an animal experiment, single-level dynamic CT through the liver was performed at 5-second intervals just after the injection of contrast medium for 3 minutes. Combinations of three different amounts (1, 2, 3 mL/kg), concentrations (150, 200, 300 mgI/mL), and injection rates (0.5, 1, 2 mL/sec) were used. The CT number of the aorta (A), portal vein (P) and liver (L) was measured in each image, and time-attenuation curves for A, P and L were thus obtained. The degree of maximum enhancement (Imax) and time to reach peak enhancement (Tmax) of A, P and L were determined, and times to equilibrium (Teq) were analyzed. In the computed-aided simulation model, a program based on the amount, flow, and diffusion coefficient of body fluid in various compartments of the human body was designed. The input variables were the concentrations, volumes and injection rates of the contrast media used. The program generated the time-attenuation curves of A, P and L, as well as liver-to-hepatocellular carcinoma (HCC) contrast curves. On each curve, we calculated and plotted the optimal temporal window (time period above the lower threshold, which in this experiment was 10 Hounsfield units), the total area under the curve above the lower threshold, and the area within the optimal range. Results: A. Animal Experiment: At a given concentration and injection rate, an increased volume of contrast medium led to increases in Imax A, P and L. In addition, Tmax A, P, L and Teq were prolonged in parallel with increases in injection time The time-attenuation curve shifted upward and to the right. For a given volume and injection rate, an increased concentration of contrast medium increased the degree of aortic, portal and hepatic enhancement, though Tmax A, P and L remained the same. The time-attenuation curve shifted upward. For a given volume and concentration of contrast medium, changes in the injection rate had a prominent effect on aortic enhancement, and that of the portal vein and hepatic parenchyma also showed some increase, though the effect was less prominent. A increased in the rate of contrast injection led to shifting of the time enhancement curve to the left and upward. B. Computer Simulation: At a faster injection rate, there was minimal change in the degree of hepatic attenuation, though the duration of the optimal temporal window decreased. The area between 10 and 30 HU was greatest when contrast media was delivered at a rate of 2 3 mL/sec. Although the total area under the curve increased in proportion to the injection rate, most of this increase was above the upper threshould and thus the temporal window was narrow and the optimal area decreased. Conclusion: Increases in volume, concentration and injection rate all resulted in improved arterial enhancement. If cost was disregarded, increasing the injection volume was the most reliable way of obtaining good quality enhancement. The optimal way of delivering a given amount of contrast medium can be calculated using a computer-based mathematical model.

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