• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.4
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• pp.213-220
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• 2023

Background: Third molar extraction is the most commonly performed minor oral surgical procedure in outpatient settings and requires regional anesthesia for pain control. Extraction of the maxillary molars commonly requires both posterior superior alveolar nerve block (PSANB) and greater palatine nerve block (GPNB), depending on the nerve innervations of the subject teeth. We aimed to study the effectiveness of PSANB alone in maxillary third molar (MTM) extraction. Methods: A sample size comprising 100 erupted and semi-erupted MTM was selected and subjected to study for extraction. Under strict aseptic conditions, the patients were subjected to the classical local anesthesia technique of PSANB alone with 2% lignocaine hydrochloride and adrenaline 1:80,000. After a latency period of 10 min, objective assessment of the buccal and palatal mucosa was performed. A numerical rating scale and visual analog scale were used. Results: In the post-latency period of 10 min, the depth of anesthesia obtained in our sample on the buccal side extended from the maxillary tuberosity posteriorly to the mesial of the first premolar (15%), second premolar (41%), and first molar (44%). This inferred that anesthesia was effectively high until the first molars and was less effective further anteriorly due to nerve innervation. The depth of anesthesia on the palatal aspect was up to the first molar (33%), second molar (67%), and lateromedially; 6% of the patients received anesthesia only to the alveolar region, whereas 66% received up to 1.5 cm to the mid-palatal raphe. In 5% of the cases, regional anesthesia was re-administered. An additional 1.8 ml PSANB was required in four patients, and another patient was administered a GPNB in addition to the PSANB during the time of extraction and elevation. Conclusion: The results of our study emphasize that PSANB alone is sufficient for the extraction of MTM in most cases, thereby obviating the need for poorly tolerated palatal injections.

• International Journal of Molecular Medicine
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• v.44 no.4
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• pp.1473-1483
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• 2019

One of the primary theories of the pathogenesis of tinnitus involves maladaptive auditory-somatosensory plasticity in the dorsal cochlear nucleus (DCN), which is assumed to be due to axonal sprouting. Although a disrupted balance between auditory and somatosensory inputs may occur following hearing damage and may induce tinnitus, examination of this phenomenon employed a model of hearing damage that does not account for the causal relationship between these changes and tinnitus. The present study aimed to investigate changes in auditory-somatosensory innervation and the role that axonal sprouting serves in this process by comparing results between animals with and without tinnitus. Rats were exposed to a noise-inducing temporary threshold shift and were subsequently divided into tinnitus and non-tinnitus groups based on the results of gap prepulse inhibition of the acoustic startle reflex. DCNs were collected from rats divided into three sub-groups according to the number of weeks (1, 2 or 3) following noise exposure, and the protein levels of vesicular glutamate transporter 1 (VGLUT1), which is associated with auditory input to the DCN, and VGLUT2, which is in turn primarily associated with somatosensory inputs, were assessed. In addition, factors related to axonal sprouting, including growth-associated protein 43 (GAP43), postsynaptic density protein 95, synaptophysin, α-thalassemia/mental retardation syndrome X-linked homolog (ATRX), growth differentiation factor 10 (GDF10), and leucine-rich repeat and immunoglobulin domain-containing 1, were measured by western blot analyses. Compared to the non-tinnitus group, the tinnitus group exhibited a significant decrease in VGLUT1 at 1 week and a significant increase in VGLUT2 at 3 weeks post-exposure. In addition, rats in the tinnitus group exhibited significant increases in GAP43 and GDF10 protein expression levels in their DCN at 3 weeks following noise exposure. Results from the present study provided further evidence that changes in the neural input distribution to the DCN may cause tinnitus and that axonal sprouting underlies these alterations.

• The Korean Journal of Pharmacology
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• v.9 no.1
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• pp.1-21
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• 1973

During the last decade extensive studios on catecholamines have evolved new knowledge in the physiology and biochemistry of adrenergic mechanism. Cardiac muscle, receiving adrenergic fibres from the stellate, cervical and thoracic ganglia, has been repeatedly shown to have a specific capacity to uptake and to store catecholamines. The catecholamine stores in cardiac muscle have also been shown to be important sites for the action of numerous drugs. Under normal condition, a certain level of catecholamines is maintained in the stores and serves as the basis for studying the changes in the catecholamine content of the heart. Because myocardial catecholamines play such important role in the patho-physiology of the heart, it would be interesting to compare the normal level of myocardial catecholamines among various species of animals. An occasional study has dealt with myocardial catecholamines of several species add ages of animals but these have been insufficiently comprehensive to afford a basis for an understanding of the importance of these amines as related to species and ages. The present investigation was undertaken to determine whether or not there is any significance of myocardial catecholamines in the course of the evolution and development of animals. Seasonal changes, sex difference and regional and subcellular distribution of myocardial catecholamines were also examined. The concentration of cardiac catecholamines was determined by the spectrophotofluorometric procedure described by Shore and Olin. The results obtained were summarized as follows: 1. As animals phylogenetically progressed larger amounts of catecholamines were resent in their hearts. A negligibly small amount of catecholamine was present in the hearts of the clam, a non-vertebrate. Among the vertebrates, cold-blooded animals (snake, turtle, frog, eel and fish) had less myocardial catecholamines than warm-blooded animals, of which aves (fowl and duck) had less than mammalia (cat, dog, rabbit, rat, cow and pig). The ratio of norepinephrine to epinephrine also was greater as the animals progress phylogenetically. 2. Examination of the regional distribution of cardiac catecholamines in warm-blooded animals showed that the content of the auricle was generally higher than that of the septum and considerably than that of the ventricle, but the differences of contents among these regions were not so marked. 3. In the embryonic chick, cardiac catecholamines were firstly detected on the 4th day of incubation, the time before the cardiac innervation of sympathetic nerves. The concentrations of these catecholamines increased but not markedly on the 6th day of incubation, soon after the innervation of sympathetic nerves to the heart. The level of the cardiac catecholamines fluctuated throughout the remainder of embryonic development. 4. In newborn rat hearts, a considerable amount of catecholamines was present. With the development of the rats, the concentrations of myocardial catecholamines increased. The ratio of epinephrine and norepinephrine fluctuated within the range of 40 to 60 pervent. However, as development progressed, the percentage of norepinephrine continued to rise, attaining the adult value of $80{\sim}90%$ after $45{\sim}60$ days. In contrast, the total amount of epinephrine remained fairly constant throughout the animal's development. 5. No significant sexual differences were observed in the concentration of myocardial catecholamines in the developing rat. 6. The catecholamines in the rabbit hearts increased during the summer season (from May to August) and maintained a fairly constant level in the other seasons of the year. 7. The subcellular distribution of cardiac catecholamines was examined by differential centrifugation of homogenates of cardiac muscles in rabbits, cats and rats. The catecholamines were found to be present approximately 20% in particles of mitochondrial fraction, 45% in particles of microsomal fraction and 35% in soluble supernatant fraction. The particle containing catecholamines in cardiac muscle appears to be two different sizes.

• Journal of Life Science
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• v.25 no.10
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• pp.1103-1109
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• 2015

Cholinergic innervation of the hippocampus is known to be correlated with learning and memory. The cholinergic agonist carbachol (CCh) modulate synaptic plasticity and produced long-term synaptic depression (LTD) in the hippocampus. However, the exact mechanisms by which the cholinergic system modifies synaptic functions in the hippocampus have yet to be determined. This study introduces an acetylcholine receptor-mediated LTD that requires internalization of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptors on the postsynaptic surface and their intracellular mechanism in the hippocampus. In the present study, we showed that the application of the cholinergic agonist CCh reduced the surface expression of GluA2 on synapses and that this reduction was prevented by the M1 muscarinic acetylcholine receptor antagonist pirenzepine in primary hippocampal neurons. The interaction between GluA2 and the glutamate receptor-interacting protein 1 (GRIP1) was disrupted in a hippocampal slice from a rat upon CCh simulation. Under the same conditions, the binding of GluA2 to adaptin-α, a protein involved in clathrin-mediated endocytosis, was enhanced. The current data suggest that the activation of LTD, mediated by the acetylcholine receptor, requires the internalization of the GluA2 subunits of AMPA receptors and that this may be controlled by the disruption of GRIP1 in the PDZ ligand domain of GluA2. Therefore, we can hypothesize that one mechanism underlying the LTD mediated by the M1 mAChR is the internalization of the GluA2 AMPAR subunits from the plasma membrane in the hippocampal cholinergic system.

• Archives of Reconstructive Microsurgery
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• v.8 no.1
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• pp.77-83
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• 1999

The skin on the dorsum of the foot is a source of the reliable thin and sensory cutaneous free tissue transplantation with or without tendon, bone and joint. A composite flap with attached vascularized tendon grafts for the combined loss of skin and tendon on the dorsum of the hand and foot offers an immediate one stage solution to this problem. The flap provides a very durable innervated tissue cover for the heel of the foot and the dorsum of the hand and an osteocutaneous transfer combined with the second metatarsal. The major dorsalis pedis artery is constant in size, but the first dorsal metatarsal artery is variable in size and location. The dorsal surface of the foot receives sensory innervation through the superficial peroneal nerve and the first web through the deep peroneal nerve. Authors had performed 5 dorsalis pedis free flap transplantation in the foot and hand at Department of Orthopedic Surgery, Chonbuk National University Hospital from August 1993 through August 1997 and followed up for the period of between 19 and 67 months until March 1999. The results were as follows 1. 5 cases dorsalis pedis free flap transfer to the foot(4 cases) and the hand(1 case) were performed and the recipient was foot dorsum and heel 2 cases each and hand dorsum 1 case. 2 All of 5 cases(100%) were survived from free flap transfer and recipient artery was dorsalis pedis artery(2 cases), anterior tibial artery(1 case), posterior tibial artery(1 case) and ulnar artery(1 case) and recipient veins were 2 in number except in the hand. 3. Long term follow up of the exterior and maceration was good and sensory recovery was poor 4. Donor site was covered with full thickness skin graft obtained from one or both inguinal areas at postoperative 3rd week and skin graft was taken good and no morbidity was showed.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.439-455
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• 1994

The purpose of this study was to investigate the distribution of nerves in the periodontal ligament of a dog's primary teeth by each developing stage. The distribution of nerves in the periodontal ligament were investigated by means of immunohistochemistry for detection of neurofilament protein (NFP). The results were as follows: The NFP-immunoreactive nerve fibers were found to be densely distributed in the apical third of the periodontal ligament, while they were sparse in the coronal two third, in both primary and permanent teeth. In generally the density of distribution and degree of arborization of nerve fibers in periodontal ligament of primary teeth revealed a poor appearance compared with that of permanent teeth. Periodontal ligament in anterior teeth showed more abundant nerve innervation than posterior teeth, and the periodontal ligament of the bifurcation area in posterior teeth roots were not observed to have nerve fiber. The density of nerve distribution in the periodontal ligament of primary teeth was reduced according to the physiological root resorption and nerve fibers were not observed in the surrounding area on the root of the exfoliation stage in primary teeth. The distribution of nerve fibers in mucogingival tissue, was poor innervated according to the aging of the dogs. A more abundant distribution of nerve fiber was represented in the lingual mucogingival tissue than in the labial side. Most of the nerve endings in the periodontal ligament of primary teeth showed a tree-like appearance. However, the typical Ruffini-like nerve endings were not observed.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.5
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• pp.369-378
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• 2000

This study was undertaken to investigate an involvement of nitroxergic innervation in gastric smooth muscle of rat. Isometric tension study, the measurement of single cell length, NADPH diaphorase stain of smooth muscle layers and neuronal nitric oxide synthase (nNOS) western blotting were performed. Sodium nitroprusside (SNP), a nitric oxide donor, relaxed the muscle strips precontracted by acetylcholine (ACh) in a concentration-dependent manner. Pretreatment of L-arginine decreased the contraction induced by electric field stimulation (EFS). Pretreatment of $N^G-nitro-L-arginine$ methyl ester (L-NAME), a NOS inhibitor, increased the EFS-induced contractions. LY 83583, a guanylate cyclase (GC) inhibitor, reversed the inhibitory actions of L-arginine on the muscle contractions. The effects of L-Arginine, L-NAME and LY 83583 on ACh-induced contractions were not significant. L-arginine reduced the EFS-induced contraction in circular muscle, whereas L-NAME enhanced the EFS-induced contraction in longitudinal strips. By EFS, the phasic contractions appeared approximately $20{\sim}25$ seconds later. L-NAME significantly shortened the delay time to about $2{\sim}3$ seconds. In single cell study, ACh contracted gastric smooth muscle cells, SNP relaxed the cells, and the latter also inhibited the ACh-induced contraction. LY 83583 enhanced the ACh-induced contraction and antagonized SNP-induced relaxation. NADPH diaphorase activity was assessed by a histochemistry, nitroblue tetrazolium (NTB) staining. Positive staining was observed in both circular and longitudinal muscle layers. L-arginine increased the staining, while L-NAME decreased the staining. Western blotting for nNOS proved the presence of nNOS in rat gastric smooth muscle. EFS and additional $Ca^{2+}$ increased nNOS protein expression. These results suggest that in rat stomach, both circular and longitudinal muscle layers are innervated with nitroxergic nerves which relax the gastric smooth muscle via NO-cGMP pathway.

• Archives of Reconstructive Microsurgery
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• v.4 no.1
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• pp.58-64
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• 1995

The radial forearm flap was first designed at the Ba-Ba Chung Hospital of People's Republic of China in 1978. The flap consists of the skin of the volar surface of the forearm, the subcutaneous fat, the underlying fascia, and the intramuscular fascia which includes the radial vessels. It is very useful flap in soft tissue coverage of skin defects of the upper and lower extremities. The authors have reported 13 cases of forearm free flap treated in the Korea University Hospital from January 1991 to Jun 1995 with a review of literature. The results were as follows. 1. We had good results in soft tissue coverage for all patients 2. The average size of flaps was $54cm^2$ and the average ischemic time of flaps was 74minutes. 3. The postoprative complication was occurred in three of 13 cases, two of three cases were arterial thrombosis treated with thrombectomy in postoperative 2 days, and one case was venous thrombosis resulted in superficial necrosis of the flap treated with STSG. 4. Forearm free flap with sensory innervation is a good donor site for reconstruction of weight-bearing areas of heel and sole. 5 The forearm free flap is suitable for soft tissue coverage of the upper and lower extremities, and can be used by skillful microsurgeon with high success rate.

• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.138-149
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• 1991

This study was aimed at investigation of the stimulatory innervations on the rat urinary bladder. Detrusor muscle strips of 15 mm long were suspended in isolated muscle chambers containing 1 ml of PSS maintained at $37^{\circ}C$ and aerated with 95% $O_2/5%CO_2$. Isometric myography was perfomed, and the results were as followings : Muscle strips showed "on-contraction" by electric field stimulation (EFS) frequency-dependently. The EFS-induced contraction was not affected by hexamethonium, a ganglion blocker, but abolished, by tetrodotoxin, a nerve conduction blocker. Physostigmine, a cholinesterase inhibitor enhanced the EFS-induced contraction which was inhibited by hemicholinium, an inhibitor of choline uptake at the cholinergic nerve ending. Such an EFS-induced contraction was antagonized by atropine only partially, and the atropine-resistant portion was completely abolished by the desensitization of purinergic receptors by prolonged incubatin of the strips in the presence of high concentratin of ATP. Bethanechol, a cholinergic agonist, elicited concentration-dependent contraction. Adenosine triphosphate (ATP), a purinergic agonist, induced a weak but concentration-dependent contraction of short duration. Bethanechol-induced contraction was not affected by ATP-desensitization, and ATP-induced contraction was not affected by tetrodotoxin. These results suggest that there are at least two main stimulatory components of innervations in the detrusor muscle, cholinergic muscarinic and purinergic ; and those receptors are independent each other.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.2
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• pp.291-305
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• 1996

The purpose of this study was to investigate the distribution of nerves in the dental pulp of early extracted primary teeth, normal exfoliated primary teeth, partially-erupted, nonfunctional, premolars, and erupted, functional, premolars. Numbers of sample were 10 teeth in each group. The distribution of nerves in the dental pulp were investigated by means of immunohisto chemistry for detection of neurofilament protein(NFP). The results were as follows: The early extracted primary teeth exhibited patterns of innervation similar to those observed for young permanent teeth. The plexiform arrangement of fibers was not evident in the primary teeth. Most nerves appear to terminate about the odontoblasts. As primary teeth began to undergo root resorption, degenerative changes such as vesicles and fragmentation appear in the nerves. The quantity of neural tissue also decreased. In teeth in which the roots were almost completely resorbed only a small number of nerves remain. There was a decrease in the number of terminal branches in the pulp of the partially erupted, nonfunctional, premolars and those present reached the pulpo-odontoblastic border. The nerve terminals in the pulp of the erupted, functional, premolars were traced to the dentinal tubule and a few nerve fibers formed loops in the predentin.