• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.586-590
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• 2009

Horsehair worms (Chordodes koreensis) develop as parasites in the bodies of grasshoppers, crickets, cockroaches, and some beetles. Chordodes koreensis is an accidental parasite of humans, livestock, or pets and poses no public health threat. The male of Chordodes koreensis in the later larval stage from canine vomitus was investigated by the scanning and transmission electron microscopy. In cross sections, the body wall is composed of four components namely epicuticle, cuticle, epidermis, and muscle layers. The parenchymal tissue fills the rest of the body and surrounds the visceral organs such as intestine, and ventral nerve cord but testes were not found. The epicuticle is a thin superficial layer whose surface shows rows of polygonal elevations called areoles. The cuticle has 17 layers of collagenous fibers spirally wound about the long axis of the worm. The section through the cuticle reveals the layers of large fibers cut obliquely lengthwise, alternating with layers of fibers sectioned obliquely crosswise. The layers of large fiber formed a double helix about longitudinal axis of the worm. The epidermis is a single layer. The muscles were interrupted by the nervous lamella in the only midventral portion. The medulla of muscle plate is composed of lightly stained cytoplasm, mitochondria, weakly developed endoplasmic reticulum, and glycogen granules. Between the medulla of a cell and the plasmalemma lies a broad cortical zone of myofilaments. The circular muscles are absent. The characteristic feature of the cytoplasm is that there was no content in peripheral mesenchyme, but was an abundance of large clear vacuoles which give the cytosome a foamy appearance. The nucleus of mesenchyme is not easily identified in our specimens.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.3
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• pp.97-106
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• 2007

The present study was attempted to investigate the effect of nicorandil, which is an ATP-sensitive potassium ($K_{ATP}$) channel opener, on secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane depolarization from the isolated perfused rat adrenal glands. The perfusion of nicorandil ($0.3{\sim}3.0mM$) into an adrenal vein for 90 min produced relatively dose-and time-dependent inhibition in CA secretion evoked by ACh (5.32 mM), high $k^+$ (a direct membrane depolarizer, 56 mM), DMPP (a selective neuronal nicotinic receptor agonist, $100{\mu}M$ for 2 min), McN-A-343 (a selective muscarinic $M_1$ receptor agonist, $100{\mu}M$ for 4 min), Bay-K-8644 (an activator of L-type dihydropyridine $Ca^{2+}$ channels, $10{\mu}M$ for 4 min) and cyclopiazonic acid (an activator of cytoplasmic $Ca^{2+}$-ATPase, $10{\mu}M$ for 4 min). In adrenal glands simultaneously preloaded with nicorandil (1.0 mM) and glibenclamide (a nonspecific $K_{ATP}$-channel blocker, 1.0 mM), the CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were recovered to the considerable extent of the control release in comparison with that of nicorandil-treatment only. Taken together, the present study demonstrates that nicorandil inhibits the adrenal CA secretion in response to stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization from the isolated perfused rat adrenal glands. It seems that this inhibitory effect of nicorandil may be mediated by inhibiting both $Ca^{2+}$ influx and the $Ca^{2+}$ release from intracellular store through activation of $K_{ATP}$ channels in the rat adrenomedullary chromaffin cells. These results suggest that nicorandil-sensitive $K_{ATP}$ channels may play an inhibitory role in the regulation of the rat adrenomedullary CA secretion.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.1
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• pp.13-23
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• 2008

The aim of the present study was designed to establish comparatively the inhibitory effects of $D_1$-like and $D_2$-like dopaminergic receptor agonists, SKF81297 and R(-)-TNPA on the release of catecholamines (CA) evoked by cholinergic stimulation and membrane depolarization from the isolated perfused model of the rat adrenal medulla. SKF81297 $(30{\mu}M)$ and R-(-)-TNPA $(30{\mu}M)$ perfused into an adrenal vein for 60 min, produced great inhibition in the CA secretory responses evoked by ACh $(5.32{\times}10^{-3}\;M)$, DMPP $(10^{-4}\;M)$, McN-A-343 $(10^{-4}\;M)$, high $K^+$ $(5.6{\times}10^{-2}\;M)$, Bay-K-8644 $(10{\mu}M)$, and cyclopiazonic acid $(10{\mu}M)$, respectively. For the release of CA evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid, the following rank order of inhibitory potency was obtained: SKF81297>R-(-)-TNPA. However, R(+)-SCH23390, a selectve $D_1$-like dopaminergic receptor antagonist, and S(-)-raclopride, a selectve $D_2$-like dopaminergic receptor antagonist, enhanced the CA secretory responses evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid only for $0{\sim}4$ min. The rank order for the enhancement of CA release evoked by high $K^+$, McN-A-343 and cyclopiazonic acid was R(+)-SCH23390>S(-)-raclopride. Also, the rank order for ACh, DMPP and Bay-K-8644 was S(-)-raclopride > R(+)-SCH23390. Taken together, these results demonstrate that both SKF81297 and R-(-)-TNPA inhibit the CA release evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors and the membrane depolarization from the isolated perfused rat adrenal gland without affecting the basal release, respectively, but both R(+)-SCH23390 and S(-)-raclopride facilitate the CA release evoked by them. It seems likely that the inhibitory effects of SKF81297 and R-(-)-TNPA are mediated by the activation of $D_1$-like and $D_2$-like dopaminergic receptors located on the rat adrenomedullary chromaffin cells, respectively, whereas the facilitatory effects of R(+)-SCH23390 and S(-)-raclopride are mediated by the blockade of $D_1$-like and $D_2$-like dopaminergic receptors, respectively: this action is possibly associated with extra- and intracellular calcium mobilization. Based on these results, it is thought that the presence of dopaminergic $D_1$ receptors may play an important role in regulation of the rat adrenomedullary CA secretion, in addition to well-known dopaminergic $D_2$ receptors.

• The Korean Journal of Pain
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• v.34 no.1
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• pp.58-65
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• 2021

Background: Supraspinal delivery of neurotensin (NTS), which may contribute to the effect of a systemically administered agonist, has been reported to be either pronociceptive or antinociceptive. Here, we evaluated the effects of systemically administered NTSR1 agonist in a rat model of neuropathic pain and elucidated the underlying supraspinal mechanism. Methods: Neuropathic pain was induced by L5 and L6 spinal nerve ligation in male Sprague-Dawley rats. The effects of intraperitoneally administered NTSR1 agonist PD 149163 was assessed using von Frey filaments. To examine the role of 5-HT neurotransmission, a serotonin (5-HT) receptor antagonist dihydroergocristine was pretreated intrathecally, and spinal microdialysis studies were performed to measure the change in extracellular level of 5-HT in response to PD 149163 administration. To investigate the supraspinal mechanism, NTSR1 antagonist 48692 was microinjected into the rostral ventromedial medulla (RVM) prior to systemic PD 149163. Additionally, the effect of intrathecal DHE on intra-RVM PD 149163 was assessed. Results: Intraperitoneally administered PD 149163 exhibited a dose-dependent attenuation of mechanical allodynia. This effect was partially reversed by intrathecal pretreatment with dihydroergocristine and was accompanied by an increased extracellular level of 5-HT in the spinal cord. The PD 149163-produced antinociception was also blocked by intra-RVM SB 48692. Direct injection of PD 149163 into the RVM mimicked the maximum effect of the same drug delivered intraperitoneally, which was reversed by intrathecal dihydroergocristine. Conclusions: These observations indicate that systemically administered NTSR1 agonist produces antinociception through the NTSR1 in the RVM, activating descending serotonergic projection to release 5-HT into the spinal dorsal horn.

• Fisheries and Aquatic Sciences
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• v.8 no.2
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• pp.97-108
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• 2005

Five species of red algae were recorded for the first time in Korea: Acrochaetium plumosum (Drew) Smith, Gelidium australe J. Agardh, Gelidium galapagense Taylor, Cryptonemia lactuca (c. Agardh) J. Agardh, and Kallymenia harveyana J. Agardh. Their habitats and morphological characters were described with illustrative figures. Acrochaetium plumosum is characterized by obovoid to clavate cells with thick walls, stellate chloroplasts with a central pyrenoid, mono sporangia that are produced singly or in a: concatenate form of two, and branching secundly and distichously. Gelidium australe is characterized by terete and slightly compressed axes and branches, terete and slightly contorted branchlets, and spatulate to lanceolate forms of tetrasporangial stichidia. Gelidium galapagense is characterized by a thallus composed of stolons and erect foliaceous branches with short digitate branchlets, and palmate forms of tetrasporangial stichidia. Cryptonemia lactuca is characterized by flabellate, subcartilagineous, strongly undulate, di-polychotomously laciniate thalli, with a midrib in the lower portion of the thallus, and tetrasporangia in the cortical layer of the small segments formed on the apical margin of the blade. Kallymenia harveyana is characterized by the gelatinoid and laminate thallus with a very short stipe, with the cortical cells compacted with small granules, and stellate cells in the medulla.

• Korean Journal of Veterinary Research
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• v.49 no.3
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• pp.215-220
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• 2009

The prevalence of potentially xenozoonotic viruses in the reproductive tract of female pigs in Korea was investigated by polymerase chain reaction (PCR). These viruses include porcine endogenous retrovirus (PERV), porcine reproductive and respiratory syndrome virus (PRRSV), swine hepatitis E virus (SHEV), porcine lymphotropic herpesvirus (PLHV), and porcine circovirus type 2 (PCV-2). Histopathological examination and PCR analysis were conducted using the ovaries of 70 slaughtered pigs that were collected from 14 farms in Jeju. Histopathologically, infiltrations of mononuclear inflammatory cells around the thick-walled coiled vessels in the ovarian medulla were observed in 15 cases. Based on the PCR method, PERV, PLHV, PRRSV, SHEV, and PCV-2 were detected in 69 (98.6%), 35 (50%), 5 (7.1%), 4 (5.7%), and 1 sample (1.4%), respectively. These results suggest that PERV and PLHV are the major xenozoonotic viruses in the porcine ovary. This study should aid in the development of a monitoring protocol for potential xenozoonotic agents and in the production of germ-free pigs for xenotransplantation.

• Korean Journal of Veterinary Research
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• v.15 no.1
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• pp.39-45
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• 1975

The authors believe that farm livestok will be greatly affected by the marked increasing use of organic phosphate. This study was carried out to observe the clinical signs and histopathological changes of mouse, guinea pig, hamster and rabbit that were orally administered with diazinon used usually as agricultural insecticide, and cholinesterase (ChE) activity was histochemically examined in the liver, heart, kidney, adrenal gland, duodenum and salivary gland of these experimental animals administered with diazinon. The results obtained were as follows: 1. Clinical signs such as dullness, severe salivation, ataxia, dyspnea, irregular slight convulsion and inappetance and as the histopathological changes cloudy swelling, congestion and hemorrhage of parenchymal organs, catarrh or local necrsois of the gastrointestinal tract, congestion or hemorrhage of the other organs were observed. Especially, hemorrhage of adrenal glands (rabbit, guinea pig) and pulmonary congestion and hemorrhage were necessarily constant. 2. In the histochemical study, ChE activity appeared intensely in the liver, heart, medulla of adrenal glands and salivary glands (submaxillary and parotid) of control animals, but ChE activity was negative or markedly decreased in experimental animals administered with diazinon. There was no marked difference between the control and experimental animals in ChE activity of the kidney. 3. Histochemical observation of ChE activity was helpful to explain the clinical signs and histopathological changes and was regarded as a diagnostic method for organic phosphate poisoning.

• Journal of Korean Neurosurgical Society
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• v.30 no.6
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• pp.781-785
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• 2001

Cervicomedullary junction arteriovenous malformation(AVM) is extremely rare. The authors present a case of a cervicomedullary junction AVM in a 31-year-old woman presenting with recurrent intraventricular hemorrhage (IVH). Magnetic resonance imaging revealed the AVM(of a size of approximately $2{\times}2.5{\times}4cm$) extending from a lower medulla to C2-3 level. Vertebral angiography demonstrated a tightly coiled vascular mass with multiple feeders (radiculomedullary arteries) and irregular-shaped aneurysm at distal part of feeder originating at right C-1 level. The patient underwent superselective embolization of upper nidus and the aneurysm. The pertinent literature is reviewed, and diagnostic and therapeutic implications are discussed.

• Journal of Veterinary Clinics
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• v.18 no.1
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• pp.70-73
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• 2001

Five-month-old a female mongrel puppy weighing 3.5 kg showed no systemic disorder and particular discomfort except abdominal distension at the first visit. On physical examination an irregular abdominal mass was palpated. One month later she was clumsy and uncoordinated. In addition, lethargy and anorexia were appeared. Then she became comatose and died in spite of initial therapy. In radiographic examination enlargement of both sides of kidney was observed. The hematological examination the dog had WBC of 16,250/$\mu$l, RBC of $7.2{\times}10^6$ $\mu$l, PCV of 32%, total protein of 8.0 g/dl, and fibrinogen of 900 mg/dl. In serum chemistry BUN was 87.4 mg/dl and creatinine was 5.1 mg/dl. Urinalysis revealed pH of 5.6, SG of 1.009 and protein of 500 mg/dl. In urine sediment test many RBCs, leukocytes, inflammatory cells and a few epithelial cells were observed. On histopathologic examination the size of right and left kidney were 15 cm, 16 cm in length, 6 cm, 6 cm in widths, respectively. Both sides of kidney were filled with brown-orange fluid and had irregular capsular surface. The cysts of various sizes were located throughout the cortex and medulla. No abnormality was found in any other organs. Histologically, cyst was lined by cuboidal to slightly flattened tubular epithelium and surrounded by mature fibrous connective tissue. Glomeruli, tubule and renal pelvis remained normal between cysts and exfoliated epithelial cells.

• Annals of Clinical Neurophysiology
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• v.2 no.2
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• pp.114-118
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• 2000

Purpose : The pathophysiology of essential tremor(ET) remains unknown. PET studies of ET showed some conflicting data. One study reported significant glucose hypermetabolism of the medulla and thalami, but other studies reported abnormal bilateral overactivity of cerebellar and red nuclear connections. The previous experimental studies suggested that each PET finding reflects a part of neural circuit which is responsible for ET. So it can be imagined that olivocerebellar oscillation may be transmitted by the way of cerebellar projections to the thalamus in ET. It has been reported that the cerebellar dentate nucleus neurons are involved in the generation and/or guidance of movement based on visual cues. The purpose of this study is to clarify the role of dentato-thalamic tract in ET. Methods : Tremor amplitudes were recorded as each patient perform two kinds of task, one involving sensory-guided movement and the other involving memory-guided movement. Each patient was asked to move his/her index finger following a smoothly moving target. He/She also was asked to perform the same movements with his/her eyes closed ET. Results : The results showed that average amplitudes of tremor were significantly higer during visually guided task than during memory guided task in ET patients. Conclusions : Our results led us to conclude that dentato-thalamic tract might be related to the control of tremor in ET.