• Journal of Biomedical Engineering Research
• /
• v.28 no.4
• /
• pp.449-454
• /
• 2007

An electrohydraulic (EH) pump-driven closed-loop blood pressure regulatory system was developed based on flow-mediated vascular occlusion using the vascular occlusive cuff technique. It is very useful for investigating blood pressure-dependant physiological variability, in particular, that could identify the principal mediators of renal autoregulation, such as tubuloglomerular feedback (TGF) and myogenic (MYO), during blood pressure regulation. To address this issue, renal perfusion pressure (RPP) should be well regulated under various experimental conditions. In this paper, we designed a new EH pump-driven RPP regulatory system capable of implementing precise and rapid RPP regulation. A closed-loop servo-controlwas developed with an optimal proportional plus integral (PI) compensation using the dynamic feedback RPP signal from animals. An in vivo performance was evaluated in terms of flow-mediated RPP occlusion, maintenance, and release responses. Step change to 80 mmHg reference from normal RPP revealed steady state error of ${\pm}3%$ during the RPP regulatory period after PI action. We obtained rapid RPP release time of approximately 300 ms. It is concluded that the proposed EH RPP regulatory system could be utilized in in vivo performance to study various pressure-flow relationships in diverse fields of physiology, and in particular, in renal autoregulation mechanisms.

• Korean Journal of Bronchoesophagology
• /
• v.9 no.1
• /
• pp.87-91
• /
• 2003

Currently gastrointestinal mesenchymal tumors are divided into three major categories: myogenic tumors(leiomyoma, leiomyosarcoma), neurogenic tumors (schwannomas) and neoplasms that belong to neither group, which are known by GIST(gastrointestinal stromal tumors). The stromal tumors are hetrogenous, so that they may show myogenic or neurogenic differentiation or both, or no differentiation at all in some patients. The best defining feature for GIST is their expression of KIT-protein(CD117). Leiomyomas are the most common mesenchymal tumor in esophagus. Esophageal GISTS are very rare in comparision to those of the stomach and intestine. Recently we experieneced one case of the esophageal GIST, so that we describe an esophageal GIST on immunohistochemical analysis. A 70 years old woman complained of dysphagia and nausea for 3 days. FGS showed a huge elevated lesion in lower esophagus 33cm distal to incisor, which was covered with normal mucosa. CT and UGI showed the intramural tumor of lower third of the esophagus. The distal esophagectomy and esophago-gastrostomy were performed. The tumor was located in lower third of esophagus and measured as $6{\times}3.7$cm in size. Immunohistochemically, it showed weakly positive CD117 and diffusely positive S-100. SMA, desmin, NES and chromogranin showed negative immune-reaction. The patient was followed for 15 month after operation. There was no recurrence.

• The Journal of Korea CHUNA Manual Medicine
• /
• v.2 no.1
• /
• pp.43-50
• /
• 2001

Objectives : Scalenus anticus syndrome and Piriformis syndrome is representative of myogenic Nerve entrapment syndrome, and their clinical symptoms are similar to HIVD(herniated Intervertebral disc) of cervical or lumbar spine. But, distinguished by muscle test, these syndrome apply to Meridian-muscle therapy. Methods : Meridian-muscle therapy consists of Ashi(阿是)-point therapy, taping therapy, myofascial release technique, manipulation, their based on the traditional meridian-muscle theory. This theory is similar to myofascial pain syndrome in western medicine. The study population consisted of 9 patients who were already diagnosed as Nerve entrapment syndrome with radiological examination & physical examination and muscle test. The evaluation of clinical outcome was done by Visual Analogue Scale (VAS) and Pain Assesment Questionnaire(PAQ). Results and Conclusions : After treatment, All patient's VAS is decreased as $2.11{\pm}1.59$ and the evaluation of clinical effect was excellent(6 cases) or good(3 cases) according to PAQ. Conclusively, Meridian muscle therapy is efficacious against Nerve entrapment syndrome.

• Biomaterials and Biomechanics in Bioengineering
• /
• v.2 no.1
• /
• pp.33-45
• /
• 2015

To engineer tissue-like structures, cells are required to organize themselves into three-dimensional networks that mimic the native tissue micro-architecture. Here, we present agarose-based multi-well platform incorporated with electrical stimulation to build skeletal muscle-like tissues in a facile and highly reproducible fashion. Electrical stimulation of C2C12 cells encapsulated in collagen/matrigel hydrogels facilitated the formation 3D muscle tissues. Consequently, we confirmed the transcriptional upregulations of myogenic related genes in the electrical stimulation group compared to non-stimulated control group in our multi-well 3D culture platform. Given the robust fabrication, engineered muscle tissues in multi-well platform may find their use in high-throughput biological studies drug screenings.

• Annals of Clinical Neurophysiology
• /
• v.7 no.2
• /
• pp.80-82
• /
• 2005

Background: Idiopathic Parkinson's disease (IPD) is closely related to Lewy body pathology. Pathological changes in medullar oblongata and pontine tegmentum have been reported in patients with subclinical motor symptom. Vestibular evoked myogenic potential (VEMP) is mediated by vestibular nuclei in lower brainstem and reflects the function of lower brainstem. The purpose of our study is to estimate the lower brainstem function in IPD patients. Methods: Ten patients with idiopathic Parkinson's disease underwent VEMP test. The patients were divided into Hohn-Yahr (H-Y) stage I (unilateral motor involvement) group and H-Y stage II or more severe (bilateral motor involvement) group. VEMP results were compared between groups using Mann-Whitney U test. Results: Among patients, 6 patients showed abnormal VEMP (unilateral abnormality 2, bilateral abnormalities 4). Between H-Y stage I group and H-Y II,III group, there was no statistical difference in the results of VEMP. Conclusions: We concluded that the lower brainstem dysfunction reflected in VEMP could occur in IPD regardless of the progression of the disease.

• Annals of Clinical Neurophysiology
• /
• v.7 no.2
• /
• pp.75-79
• /
• 2005

Vestibular evoked myogenic potentials (VEMP) have been known to useful in documenting abnormality in patients with various vestibular disorders but the studies of VEMP in stroke patients are rare. We recorded VEMP in 17 consecutive patients with acute ischemic stroke in the brainstem lesions. All patients underwent magnetic resonance imaging and we compare VEMP results with the lesion documented by brain imaging. VEMP were defined to be abnormal when they were very asymmetrical (one is 2 times of more as large as the other), or absent in one side. VEMP abnormalities were found in 71%(12/17) of acute infarction patients with brainstem lesions. Most abnormalities found in the ipsilateral side of the lesion(9/12) but abnormalities in contralateral side of lesion were found in 25%(3/12) of patients.VEMP would be considered a useful complementary neurophysiological tool for the evaluation of brainstem dysfunction in acute stroke patients.

• Journal of Audiology & Otology
• /
• v.23 no.1
• /
• pp.49-52
• /
• 2019

Background and Objectives: Considering important role of vitamin D in many physiological processes including vestibular system in the ear, aim of present study is to evaluate saccule function via cervical vestibular evoked myogenic potential (cVEMP), in patients with vitamin D deficiency. Subjects and Methods: After routine audiological tests, cVEMP were recorded in 15 patients with vitamin D deficiency and 16 normal subjects. The short tone burst (95 dB nHL, 500 Hz) was presented to ears. cVEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid muscle. Results: Mean of p13, n13, interpeak latencies and amplitude ratios were measured in both groups. Statistical analysis did not show differences between two groups. Conclusions: Maybe serum 25-hydroxyvitamin D concentration was not low enough to have effect on saccule in the patients in present study or saccule have had low susceptibility to effects of vitamin D deficiency. For better judgment about effect of vitamin D deficiency on saccular function planning studies with high sample size is recommended.

• Korean Journal of Audiology
• /
• v.23 no.1
• /
• pp.49-52
• /
• 2019

Background and Objectives: Considering important role of vitamin D in many physiological processes including vestibular system in the ear, aim of present study is to evaluate saccule function via cervical vestibular evoked myogenic potential (cVEMP), in patients with vitamin D deficiency. Subjects and Methods: After routine audiological tests, cVEMP were recorded in 15 patients with vitamin D deficiency and 16 normal subjects. The short tone burst (95 dB nHL, 500 Hz) was presented to ears. cVEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid muscle. Results: Mean of p13, n13, interpeak latencies and amplitude ratios were measured in both groups. Statistical analysis did not show differences between two groups. Conclusions: Maybe serum 25-hydroxyvitamin D concentration was not low enough to have effect on saccule in the patients in present study or saccule have had low susceptibility to effects of vitamin D deficiency. For better judgment about effect of vitamin D deficiency on saccular function planning studies with high sample size is recommended.

• Journal of Sericultural and Entomological Science
• /
• v.51 no.2
• /
• pp.99-106
• /
• 2013

The purpose of this study is to investigate the effects of supplementation of mulberry powder, mulberry extract and silkworm powder during the 8 weeks of resistance exercise on Androgen receptor(AR) mRNA and Myogenic regulatory factors(MRFs) expression of rats muscle. Fifty males, Sprague-Dawley rat, were randomly divided into 5 groups: CON(control group, n = 10), REG(resistance exercise group, n = 10), MP REG(mulberry powder intake and resistance exercise group, n = 10), ME REG(mulberry extract intake and resistance exercise group, n = 10) and SP REG(silkworm powder intake and resistance exercise group, n = 10). After climbing the ladder without weights during the 1 week of adaptation period, the rats in the resistance exercise group were trained to climb a 0.98-m vertical(80 degree incline) ladder with weights in their tail during 7 weeks(10 times each day, 2 days per week). After exercise, the skeletal muscle was extracted from the flexor hallucis longus. After separating the total ribonucleic acid (RNA) of each group, quantitative polymerase chain reaction was used to analyze RNA quantitatively. AR mRNA and MRFs expression revealed that all of the treated groups had significantly difference. AR mRNA expression increased in ME REG $6.24{\pm}1.85$ and SP REG $9.68{\pm}0.28$ fold compared to CON. Myod mRNA expression increased in MP REG $6.04{\pm}0.47$, ME REG $4.31{\pm}1.58$ and SP REG $8.11{\pm}0.57$ fold compared to CON. And myogenin mRNA expression increased in MP REG $4.11{\pm}0.42$, ME REG $4.12{\pm}0.45$ and SP REG $6.50{\pm}0.61$ fold compared to CON. In conclusion, during the resistance exercise, providing mulberry and silkworm gives positive effect on AR mRNA and MRFs expression increase.

• Journal of Ginseng Research
• /
• v.44 no.3
• /
• pp.435-441
• /
• 2020

Background: As a process of aging, skeletal muscle mass and function gradually decrease. It is reported that ginsenoside Rb1 and Rb2 play a role as AMP-activated protein kinase activator, resulting in regulating glucose homeostasis, and Rb1 reduces oxidative stress in aged skeletal muscles through activating the phosphatidylinositol 3-kinase/Akt/Nrf2 pathway. We examined the effects of Rb1 and Rb2 on differentiation of the muscle stem cells and myotube formation. Methods: C2C12 myoblasts treated with Rb1 and/or Rb2 were differentiated and induced to myotube formation, followed by immunoblotting for myogenic marker proteins, such as myosin heavy chain, MyoD, and myogenin, or immunostaining for myosin heavy chain or immunoprecipitation analysis for heterodimerization of MyoD/E-proteins. Results: Rb1 and Rb2 enhanced myoblast differentiation through accelerating MyoD/E-protein heterodimerization and increased myotube hypertrophy, accompanied by activation of Akt/mammalian target of rapamycin signaling. In addition, Rb1 and Rb2 induced the MyoD-mediated transdifferentiation of the rhabdomyosarcoma cells into myoblasts. Furthermore, co-treatment with Rb1 and Rb2 had synergistically enhanced myoblast differentiation through Akt activation. Conclusion: Rb1 and Rb2 upregulate myotube growth and myogenic differentiation through activating Akt/mammalian target of rapamycin signaling and inducing myogenic conversion of fibroblasts. Thus, our first finding indicates that Rb1 and Rb2 have strong potential as a helpful remedy to prevent and treat muscle atrophy, such as age-related muscular dystrophy.