• Title/Summary/Keyword: injury threshold

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Increased calcium-mediated cerebral processes after peripheral injury: possible role of the brain in complex regional pain syndrome

  • Nahm, Francis Sahngun;Lee, Jae-Sung;Lee, Pyung-Bok;Choi, Eunjoo;Han, Woong Ki;Nahm, Sang-Soep
    • The Korean Journal of Pain
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    • v.33 no.2
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    • pp.131-137
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    • 2020
  • Background: Among various diseases that accompany pain, complex regional pain syndrome (CRPS) is one of the most frustrating for patients and physicians. Recently, many studies have shown functional and anatomical abnormalities in the brains of patients with CRPS. The calcium-related signaling pathway is important in various physiologic processes via calmodulin (CaM) and calcium-calmodulin kinase 2 (CaMK2). To investigate the cerebral mechanism of CRPS, we measured changes in CaM and CaMK2 expression in the cerebrum in CRPS animal models. Methods: The chronic post-ischemia pain model was employed for CRPS model generation. After generation of the animal models, the animals were categorized into three groups based on changes in the withdrawal threshold for the affected limb: CRPS-positive (P), CRPS-negative (N), and control (C) groups. Western blot analysis was performed to measure CaM and CaMK2 expression in the rat cerebrum. Results: Animals with a decreased withdrawal threshold (group P) showed a significant increment in cerebral CaM and CaMK2 expression (P = 0.013 and P = 0.021, respectively). However, groups N and C showed no difference in CaM and CaMK2 expression. Conclusions: The calcium-mediated cerebral process occurs after peripheral injury in CRPS, and there can be a relationship between the cerebrum and the pathogenesis of CRPS.

Effect of Dehydroepiandrosterone on Affected and Unaffected Hindlimb Muscles in Rats with Neuropathic Pain Induced by Unilateral Peripheral Nerve Injury (DHEA 투여가 일측성 말초신경 손상에 의해 유발된 신경병증성 통증 쥐의 환측과 정상측 뒷다리근에 미치는 영향)

  • Choe, Myoung-Ae;An, Gyeong-Ju
    • Journal of Korean Academy of Nursing
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    • v.39 no.5
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    • pp.632-640
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    • 2009
  • Purpose: The purpose of this study was to examine the effect of DHEA (Dehydroepiandrosterone) on muscle weight and Type I and II fiber cross-sectional area of affected and unaffected hindlimb muscles in rats with neuropathic pain induced by unilateral peripheral nerve injury. Methods: Neuropathic pain was induced by ligation and cutting of the left L5 spinal nerve. Adult male Sprague-Dawley rats were randomly assigned to one of two groups: The DHEA group (n=10) had DHEA injections daily for 14 days, and the Vehicle group (n=10) had vehicle injections daily for 14 days. Withdrawal threshold, body weight, food intake and activity were measured every day. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected from the both hindlimbs. Body weight, food intake, activity, muscle weight and Type I, II fiber cross-sectional area of the dissected muscles were measured. Results: The DHEA group showed significant increases (p<.05), as compared to the vehicle group for muscle weight of the unaffected plantaris, and in Type II fiber cross-sectional area of the gastrocnemius muscle. The DHEA group demonstrated a higher pain threshold than the vehicle group whereas total diet intake and activity score were not significantly different between the two groups. Conclusion: DHEA administration for 14 days attenuates unaffected plantaris and gastrocnemius muscle atrophy.

The Effect of Urinary Trypsin Inhibitor Against Neuropathic Pain in Rat Models

  • Jung, Ki Tae;Lee, Hyun Young;Yoon, Myung Ha;Lim, Kyung Joon
    • The Korean Journal of Pain
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    • v.26 no.4
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    • pp.356-360
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    • 2013
  • Background: Nerve injury sometimes leads to chronic neuropathic pain associated with neuroinflammation in the nervous system. In the case of chronic neuropathic pain, the inflammatory and algesic mediators become predominant and result in pain hypersensitivity following nervous system damage. It is well known that urinary trypsin inhibitor (ulinastatin, UTI) has an anti-inflammatory activity. Recently, the neuroprotective action of UTI on the nervous system after ischemic injury has been reported. Thus, we evaluated the neuroprotective effect of ulinastatin in a rat model of neuropathic pain. Methods: Neuropathic pain was induced with L5 spinal nerve ligation (SNL) in male Sprague-Dawley rats weighing 100-120 g. The rats were divided into 3 groups, with n = 8 in each group. The rats in the control group (group 1) were administered normal saline and those in group 2 were administered UTI (50,000 U/kg) intravenously through the tail vein for 3 days from the day of SNL. Rats in group 3 were administered UTI (50,000 U/kg) intravenously from the $5^{th}$ day after SNL. The paw withdrawal threshold was measured using the von Frey test for 3 days starting from the $5^{th}$ day after SNL. Results: The paw withdrawal thresholds were significantly increased in the rats of group 2 compared to the other groups (P < 0.05). Conclusions: Ulinastatin, which was administered for 3 days after SNL, increased the paw withdrawal threshold and it could have a neuroprotective effect in the rat model of neuropathic pain.

Evaluation of Sensory Nerve Function Before and after Intraoral Vertico-Sagittal Ramus Osteotomy Using Current Perception Threshold(CPT) Test (구강내하악지수직시상골절단수술 전후 전류역치검사(CPT)를 이용한 지각신경의 변화에 대한 연구)

  • Choung Pill-Hoon;Kim Sao-Geol;Seo Byoung-Moo
    • Korean Journal of Cleft Lip And Palate
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    • v.4 no.1
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    • pp.39-43
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    • 2001
  • The design of osteotomy plane in orthognathic surgery has been developed to diminish the nerve injury. Intraoral Vertico-Sagittal Ramus Osteotomy (IVSRO) is the one of the best way to minimize untoward results, which is designed not to expose the lingula. We evaluated the nerve damage before and after with current perception threshold (CPT) test which is modem and numerically expressible way of nerve damages. Sixty patients underwent IVSRO since 1998 were evaluated. They were divided into 2 groups; one group underwent IVSRO only, and the other underwent IVSRO plus genioplasty. The both groups were evaluated with CPT test 1 week before surgery, and 1, 3 and 6 months after surgery. The CPT test was performed on A-beta, A-delta and C fiber respectively. 111e result showed that the recovery of sensory function of damaged nerve fibers was observed at the period of three to six months after surgery. There was no impairment of nerve function after only the IVSRO . But there were sensory disturbances in cases of additional genioplasty group. We thought that one of major factors on nerve damages were exposure of nerve and traction injury during genioplasty.

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A Comparison of The Effect of Stretching Technique on Hamstring Muscle for Flexibility, Strength, Pressure Pain Threshold Value and Muscle Tone (스트레칭 기법에 따른 뒤넙다리근의 유연성, 근력, 압통 역치, 근 긴장도에 미치는 효과 비교)

  • Park, Hoon-Young;Lee, Myung-Mo
    • Journal of the Korean Society of Physical Medicine
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    • v.12 no.4
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    • pp.39-46
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    • 2017
  • PURPOSE: The effectiveness of the stretching to increase the range of motion of the joint, reduce the risk of injury, enhance athletic performance or decrease post exercise muscle soreness. This study was to compare the effect of the stretching method applied on the shortened hamstring muscle for flexibility, strength, pressure pain threshold value and muscle tone. METHODS: This study is a two-group pretest- posttest design. Fifty-four healthy young adults were randomly assigned to a vibration-assisted stretching group (VASG, n=27) or a static stretching group (SSG, n=27). Participants performed each stretch in 4 sets of 30 seconds each. A 30-second break time was provided between the sets. The range of motion, strength, pressure pain threshold values and muscle tone of the hamstring muscle were measured to compare the effects of the stretching methods. RESULTS: Both the VASG and the SSG participants showed significant improvement in the range of motion and strength (p<.05); however, the increase in the VASG was significantly higher than that in the SSG (p<.05). The pressure pain threshold values and muscle tone were significantly decreased only in the VASG (p<.05). CONCLUSION: These findings indicate that vibration-supported stretching is an effective intervention for people with hamstring shortening, with high pain level and muscle tone decrease.

Establishment of Economic Threshold by Evaluation of Yield Component and Yield Damages Caused by Leaf Spot Disease of Soybean (콩 점무늬병(Cercospora sojina Hara) 피해해석에 의한 경제적 방제수준 설정)

  • Shim, Hongsik;Lee, Jong-Hyeong;Lee, Yong-Hwan;Myung, Inn-Shik;Choi, Hyo-Won
    • Research in Plant Disease
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    • v.19 no.3
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    • pp.196-200
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    • 2013
  • This study was carried out to investigate yield loss due to soybean leaf spot disease caused by Cercospora sojina Hara and to determine the economic threshold level. The investigations revealed highly significant correlations between disease severity (diseased leaf area) and yield components (pod number per plant, total grain number per plant, total grain weight per plant, percent of ripened grain, weight of hundred seed, and yield). The correlation coefficients between leaf spot severity and each component were -0.90, -0.90, -0.92, -0.99, -0.90 and -0.94, respectively. The yield was inversely proportional to the diseased leaf area increased. The regression equation, yield prediction model, between disease severity (x) and yield (y) was obtained as y = -3.7213x + 354.99 ($R^2$ = 0.9047). Based on the yield prediction model, economic injury level and economic threshold level could be set as 3.3% and 2.6% of diseased leaf area of soybean.

Determination of Economic Injury Levels (EILs) and Control Thresholds (CTs) of Aphis egomae (Hom.: Aphididae) in Green Perilla (들깨진딧물의 경제적 피해수준과 요방제수준 설정에 관한 연구)

  • Choi, Yong-Seok;Park, Deok-Gi;Han, Ik-Soo;Choe, Kwang-Ryul
    • Korean journal of applied entomology
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    • v.45 no.3 s.144
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    • pp.317-325
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    • 2006
  • According to the preceding survey on insect pests of the green perilla, Perilla frutescens var. japonica HARA, The major pests were Aphis egomae Shinji, Pyrausta panopealis (Walker), Tetranychus urticae Koch, Polyphagotarsonemus lotus Banks, Tetranychus kanzawai Kishida at Guemsan, Chungnam, 2004. Aphis egomae causes nearly 100% injury of the green perilla in uncontrolled green houses. A field study was conducted to estimate economic injury levels (EILs) and control thresholds (CTs) for A. egomae injuring green perilla in green houses. Different densities of A. egomae ranged from 1 to 80 aphids per 100 plants in early inoculation. The mean injurying rate of plant was 2.4% to 40.5% at the end of June at differently inoculated levels. The economic loss time calculated by the ratio of cost managing aphid to market price (C/V) (C: cost managing aphid, V: Market price) in early season (from May to 13. June) was 5.8% and in peak season (from 13. June to 30. June) was 9.3%. Economic injury level in early and peak season was 5.3 aphids per plant and economic injury levels in peak season were 0.6 aphids per plant and 7.6% injured rate of plant. The control thresholds calculated by 80% level of economic injury level in peak season were 0.5aphids per plant and 6.1% injury rate of plant, respectively.

Effect of Perioperative Perineural Injection of Dexamethasone and Bupivacaine on a Rat Spared Nerve Injury Model

  • Lee, Jeong-Beom;Choi, Seong-Soo;Ahn, Eun-Hye;Hahm, Kyung-Don;Suh, Jeong-Hun;Leem, Jung-Gil;Shin, Jin-Woo
    • The Korean Journal of Pain
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    • v.23 no.3
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    • pp.166-171
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    • 2010
  • Background: Neuropathic pain resulting from diverse causes is a chronic condition for which effective treatment is lacking. The goal of this study was to test whether dexamethasone exerts a preemptive analgesic effect with bupivacaine when injected perineurally in the spared nerve injury model. Methods: Fifty rats were randomly divided into five groups. Group 1 (control) was ligated but received no drugs. Group 2 was perineurally infiltrated (tibial and common peroneal nerves) with 0.4% bupivacaine (0.2 ml) and dexamethasone (0.8 mg) 10 minutes before surgery. Group 3 was infiltrated with 0.4% bupivacaine (0.2 ml) and dexamethasone (0.8 mg) after surgery. Group 4 was infiltrated with normal saline (0.2 ml) and dexamethasone (0.8 mg) 10 minutes before surgery. Group 5 was infiltrated with only 0.4% bupivacaine (0.2 ml) before surgery. Rat paw withdrawal thresholds were measured using the von Frey hair test before surgery as a baseline measurement and on postoperative days 3, 6, 9, 12, 15, 18 and 21. Results: In the group injected preoperatively with dexamethasone and bupivacaine, mechanical allodynia did not develop and mechanical threshold forces were significantly different compared with other groups, especially between postoperative days 3 and 9 (P < 0.05). Conclusions: In conclusion, preoperative infiltration of both dexamethasone and bupivacaine showed a significantly better analgesic effect than did infiltration of bupivacaine or dexamethasone alone in the spared nerve injury model, especially early on after surgery.

Economic Injury Level of Mamestra brassicae L. (Lepidoptera: Noctuidae) on Early Stage of Cabbage (Brassica oleracea L. var capitata L.) (양배추에서 생육초기 도둑나방의 경제적피해수준 설정)

  • Kang, Taek-Jun;Jeon, Heung-Yong;Kim, Hyeong-Hwan;Yang, Chang-Yeol;Kim, Dong-Soon
    • Korean journal of applied entomology
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    • v.48 no.2
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    • pp.237-243
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    • 2009
  • This study was conducted to develop economic injury level (ElL) and economic threshold (ET) of Cabbage armyworm, Mamestra brassicae L. on cabbage (Brassica oleracea L. var). The changes of cabbage biomass and M. brassicae density were investigated after introduction of larval M. brassicae (2nd instar) at different densities: 0, 1, 2, 4, 8, and 16 larvae per plant at 40 d after planting for an open field experiment, and 0, 2, 5, 8 and 12 larvae per plant at 25 d after planting for a glass house experiment. In the field experiment, the yield loss of cabbage was not significantly different among treated-plots at 30 d after the larval introduction, showing an over-compensatory response of cabbage plants to M. brassicae attack. In the glasshouse experiment, however, the biomass of cabbage at 15 d after the larval introduction significantly decreased with increasing the initial introduced number of M. brassicae, resulting in 38.3, 36.7, 21.7, 23.3 and 16.7g in above treated-plots, respectively. The relationship between cumulative insect days (CID) and yield loss (%) of cabbage was well described by a nonlinear logistic equation. Using the estimated equation, ElL of M. brassicae on cabbage was estimated at 44 CID per plant based on the yield loss 14%, which take into account of an empirical gain threshold 5% and marketable rate 91% of cabbage. Also, ET was calculated at 80% of the EIL: 35 CID per plant. Until a more elaborate EIL-model is developed, the present result may be useful for M. brassicae management at early growth stage of cabbage.

A Study on Characteristics of Passenger Injury for Effective Impact Speed in Vehicles Frontal Collision and Rear-ender (차량 정면충돌 및 추돌시 유효충돌속도에 따른 탑승자 상해특성에 관한 연구)

  • Cho, Joeng-Kwon;Yoon, Jun-Kyu;Lim, Jong-Han
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.4
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    • pp.239-247
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    • 2015
  • Recently, various research studies on frontal collision and rear-ender which occur more frequently compared to others are underway as the public interest on them is growing. This study analyzes scientifically the relationship between effective impact speed and injury incidence for vehicle crash accident reconstruction and presents a relevant model formula. Because real vehicle experiments have certain limitations such as possible injuries, this study efforts to collect and analyze as many materials as possible to substitute real vehicle experiments, including data from various collision tests and human experiments. As a result, this study present a threshold in which head-on collisions and rear impacts do not cause injuries under 7 km/h of effective impact speed, and suggests a model formula showing that injury extent is linearly proportional to effective impact speed through collision speed and amount of plastic deformation. In conclusion, a model formula for estimating effective impact speed and injury incidence newly proposed in this study is expected to be used as a minimum standard of judgment in disputes on the injury extent of passenger in head-on collisions and rear impacts. Furthermore its availability in terms of technological analysis in legal arguments is expected to be very high if this study will be enhanced by referring to scientific analyses of various real accidents so as to apply it in various types of collision accidents.