• 한국운동역학회지
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• 제17권2호
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• pp.145-156
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• 2007

The purposes of this study were to investigate kinematic parameters of racket head and upper extremities during squash back hand stroke and to provide quantitative data to the players. Five Korean elite male players were used as subjects in this study. To find out the swing motion of the players, the land-markers were attached to the segments of upper limb and 3-D motion analysis was performed. Orientation angles were also computed for angular movement of each segment. The results were as follows. 1) the average time of the back hand swing (downswing + follow-through) was 0.39s (0.24 s + 0.15 s). 2) for each event, the average racket velocity at impact was 11.17m/s and the velocity at the end of swing was 8.03m/s, which was the fastest swing speed after impact. Also, for each phase, 5.10m/s was found in down swing but 7.68m/s was found in follow-through. Racket swing speed was fastest after the impact but the swing speed was reduced in the follow-through phase. 3) in records of average of joints angle, shoulder angle was defined as the relative angle to the body. 1.04rad was found at end of back swing, 1.75rad at impact and it changes to 2.35 rad at the end of swing. Elbow angle was defined as the relative angle of forearm to upper arm. 1.73rad was found at top of backswing, 2.79rad at impact, and the angle was changed to 2.55rad at end of swing. Wrist angle was defined as the relative angle of hand to forearm. 2.48rad was found at top of backswing, 2.86rad at impact, and the angle changes to 1.96rad at end of swing. As a result, if the ball is to fly in the fastest speed, the body has to move in the order of trunk, shoulder, elbow and wrist (from proximal segment to distal segment). Thus, the flexibility of the wrist can be very important factor to increase ball speed as the last action of strong impact. In conclusion, the movement in order of the shoulder, elbow and the wrist decided the racket head speed and the standard deviations were increased as the motion was transferred from proximal to the distal segment due to the personal difference of swing arc. In particular, the use of wrist (snap) may change the output dramatically. Therefore, it was concluded that the flexible wrist movement in squash was very important factor to determine the direction and spin of the ball.

• Clinical and Experimental Pediatrics
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• 제46권12호
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• pp.1242-1247
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• 2003

목 적 : 다른 특별한 병력이 없는 영아들에서 흡인으로 인한 만성 기침이 의심되는 경우, 상부 식도 24시간 pH 검사를 시행하여, 그 결과를 일반적으로 위식도 역류를 진단하기 위해 시행하는 하부 식도 24시간 pH 검사의 결과치와 비교하여 상부 식도 24시간 pH 검사에 대한 유용성을 평가하고자 하였다. 방 법 : 3주 이상의 만성 기침을 주소로 인하대병원 소아과에 입원한 1세 이하 영아들 중, 흉부 단순 촬영상 특이소견이 없고 그 원인이 뚜렷하지 않은 환아들을 상대로 흉부 전산화 단층 촬영을 시행한 결과, 의존성 위치에서 폐 경화를 보여 역류로 인한 흡인의 가능성이 높은 17명의 환아들을 본 연구의 대상으로 하여 상부와 하부 식도 24시간 pH 검사를 시행하였다. 결 과 : 1) 대상 환아는 17명(남아 12명, 여아 5명)으로 평균 연령은 4.3개월($4.3{\pm}1.8$개월)이었다. 2) 총 17명의 환아들 중, 상부 식도에서 병적인 위산 역류를 보인 환아는 15명(88.2%)이었고, 하부 식도에서는 4명(23.5%)으로, 상부 식도에서 이상 소견을 보인 환아들이 더 많았다(P<0.01). 하부 식도에서 정상 범위의 역류를 보이더라도 상부 식도에서 병적인 역류를 보이는 경우는 13명 중 12명(92.3%)이었다. 3) 상부 식도 24시간 pH 검사에서 역류지표와 역류빈도가 하부 식도 24시간 pH 검사에서보다 통계적으로 의미 있게 낮았다(P<0.05). 4) 하부 식도 24시간 pH 검사 결과와 상부 식도 24시간 pH 검사 결과들 사이에는 상관관계가 없었다. 5) 하부 식도 24시간 pH 검사에 있어서, 위식도 역류로 진단을 받은 군(group 1)과 정상으로 진단을 받은 군(group 2)의 상부 식도 24시간 pH 검사 결과와의 차이를 비교했을 때, group 2에서 상부 식도에서도 역류빈도가 통계적으로 의미 있게 낮았다(P<0.05). 결 론 : 만성 기침을 보이는 영아들에 있어서 뚜렷한 위식도 역류 증상은 없지만 위식도 역류에 의한 흡인이 의심되는 경우에 상부 식도 24시간 pH 검사가 필수적인 진단 방법으로 제시하는 것에 본 연구의 의의가 있다.

• The Korean Journal of Physiology
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• 제25권2호
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• pp.189-200
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• 1991

During the past few years it has been proposed that lithium clearance can be used as a reliable measure for the outflow of tubular fluid from the proximal tubule. This study was aimed to characterize the inflow dependent reabsorption of Na in renal tubule beyond the proximal tubule. For this purpose, lithium clearance was used as a measure for the inflow from the proximal tubule and the changes in reabsorption fraction of Na and water were determined in rabbits. Rabbits were pretreated with hypotonic saline solutions for an hour (50 mM/L NaCl, 20 ml/hr/kg). And then a hypertonic solution of 500 mM/L NaCl (20 ml/kg) was administered intraperitoneally in conjunction with a bolus of LiCl solution (2 mM/kg, i.v.) for conditioning the $C_{Li}$ and urine flow rate. To rule out the effect of $Li^+$ on tubular functions, a bolus of NaCl solution (2 mM/kg, i.v.) was administered. Fifteen, thirty, and sixty minutes after injection of hypertonic saline arterial blood and urine samples were taken. Urinary and plasma concentrations as well as urinary output of $Li^+,\;Na^+\;and\;K^+$ were measured. From these $C_{Li},\;C_{Na}$ and the reabsorption fraction of Na and water $(Fr_{Na}\;&\;FrH_2O)$ were calculated. These results were compared with those from control groups in which the same amount of isotonic saline (145 mM/L NaCl) and of 15% dextran solution were administered in the same way as that in experimental group. Followings are the results obtained. 1) The plasma concentration of $Na^+$ in rabbits injected with hypertonic saline reached the peak value after 15 min and thereafter no significant change was observed. Hematocrit values did not show any change, while urinary excretion of $Na^+$ increased markedly during the first 15 min and decreased thereafter. These results were not affected by an injection of a small amount of LiCl. 2) The clearances of $Li^+,\;Na^+\;and\;K^+$ in rabbits injected with hypertonic saline and LiCl solution decreased. 3) In spite of the variation in $C_{Li},\;Fr_{Na}$ did not show any significant change while $FrH_2O$ increased gradually. 4) $C_{Li}$ decreased also in rabbits received isotonic saline. $Fr_{Na}$ tended to be higher than that in hypertonic saline group, while $FrH_2O\;and\;Fr_{Na}$ did not associated with the decrease in $C_{Li}$. 5) $C_{Li}$ of the rabbits received dextran solution fluctuated persistently and $Fr_{Na}\;and\;FrH_2O$ did not change in along with $C_{Li}$ although $Fr_{Na}$ had a tendency to be higher than that in hypertonic saline group. 6) From the above results it was concluded that: (a) In rabbits with normal body store of $Na^+$, the $Fr_{Na}$ of renal tubule beyond proximal tubule. calculated from $C_{Li}$ as a measure of inflow from proximal tubule is constant in spite of variations in $C_{Li}$. (b) The $FrH_2O$ calculated from $C_{Li}$ is dependent largely upon ADH rather than inflow from proximal tubule. (c) When there is a decrease in plasma $Na^+$ concentration or ineffective body fluid. $Li^+$ reabsorption may occur in the thick segnent of Henle's loop and hence the determination of $Fr_{Na}$ and $FrH_2O$ will not be easy one, but $Fr_{Na}$ is constant under the same experimental conditions.

• Advances in pediatric surgery
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• 제1권1호
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• pp.68-72
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• 1995

Segmental dilatation of the colon is a very rare disease entity of unknown etiology and may mimic Hirschsprung's disease. It is characterized by dilatation of a segment of the colon of variable length with obstruction due to lack of peristalsis in a normally innervated intestine. Recently authors experienced a case of segmental dilatation of the sigmoid colon in a 6 month-old male, who presented with severe constipation, abdominal distention, and abdominal mass since 2 months of age. Down's syndrome and congenital nystagmus were associated. Barium enema demonstrated focal dilatation of the sigmoid colon, but the rectum and descending colon proximal t o the affected colon were of normal caliber. Rectal suction biopsy with acetylcholinesterase staining was normal and anorectal manometry showed normal rectosphincteric reflex. At operation, there was a massively dilated and hypertrophied sigmoid colon with increased tortuous serosal vessels, measuring 15 cm in length and 10 cm in width. Teniae coli were identifiable in the affected segment. Frozen section biopsies at the proximal, affected, and distal colon showed ganglion cells. Descending loop colostomy was constructed initially and segmental resection and end to end colocolostomy were carried out 3 months later. Final histologic examination showed 1) normal colonic mucosa with ganglion cells, 2) prominent submucosal fibrosis and marked muscular hypertrophy, 3) unremarkable acetylcholinesterase activity and immunohistochemical findings against S-100 protein. On 8 months follow-up, he has been doing well and moves bowels 1-2 times daily.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권5호
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• pp.217-223
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• 2013

Objectives: Buccal fracture of the mandibular proximal bone segment during bilateral sagittal split ramus osteotomy (SSRO) reduces the postoperative stability. The primary aim of this study is to evaluate the effect of this type of fracture on bone healing and postoperative stability after mandibular setback surgery. Materials and Methods: Ten patients who experienced buccal fracture during SSRO for mandibular setback movement were evaluated. We measured the amount of bone generation on a computed tomography scan, using an image analysis program, and compared the buccal fracture side to the opposite side in each patient. To investigate the effect on postoperative stability, we measured the postoperative relapse in lateral cephalograms, immediately following and six months after the surgery. The control group consisted of ten randomly-selected patients having a similar amount of set-back without buccal fracture. Results: Less bone generation was observed on the buccal fracture side compared with the opposite side (P<0.05). However, there was no significant difference in anterior-posterior postoperative relapse between the group with buccal fracture and the control group. The increased mandibular plane angle and anterior facial height after the surgery in the group with buccal fracture manifested as a postoperative clockwise rotation of the mandible. Conclusion: Bone generation was delayed compared to the opposite side. However, postoperative stability in the anterior-posterior direction could be maintained with rigid fixation.

• Journal of Korean Neurosurgical Society
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• 제54권2호
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• pp.75-80
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• 2013

Objective : Aneurysms arising from the proximal segment of the anterior cerebral artery (A1) are rare and challenging to treat. The aim of this study was to report our experience with endovascular treatment of A1 Aneurysms. Methods : From August 2007 through May 2012, eleven A1 aneurysms in eleven patients were treated endovascularly. Six aneurysms were unruptured and 5 were ruptured. One patient with an unruptured A1 aneurysm presented with subarachnoid hemorrhage due to rupture of an anterior communicating artery aneurysm. Procedural data, clinical and angiographic results were reviewed retrospectively. Results : All of the aneurysms were successfully treated with coil embolization. Six were treated with a simple technique while the remaining 5 required adjunctive technique : double catheters (n=2), balloon-assisted (n=2), and stent-assisted (n=1). The immediate angiographic control showed a complete occlusion in all cases. Procedure-related complication occurred in only one patient : parent artery occlusion, which was not clinically significant. All patients had excellent clinical outcomes but one patient was discharged with a slight disability. No neurologic deterioration or bleeding was seen during the follow-up period in this cohort of patients. Follow-up angiography (mean, 20 months) was available in ten patients and revealed stable occlusion in all cases. Conclusion : Endovascular treatment is a feasible and effective therapeutic modality for A1 aneurysms. Tailored microcatheter shaping and/or adjunctive techniques are necessary for successful aneurysm embolization because of the projection and location of A1 aneurysms.

• 대한족부족관절학회지
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• 제18권4호
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• pp.178-182
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• 2014

Purpose: The purpose of this study was to evaluate the frequency of troughing and stress fracture, which are the major complications of scarf osteotomy, and to suggest methods to prevent these complications. Materials and Methods: We reviewed 243 cases of 137 patients treated with the scarf osteotomy for hallux valgus from January 2005 to December 2012. The mean follow-up period was 2.8 years. During the scarf osteotomy, a long oblique longitudinal osteotomy was performed in order to decrease the possibility of troughing and stress fracture. Radiographs of lateral view of the foot were obtained and the thicknesses of the first metatarsal base at the sagittal plane were measured and compared. Results: There was no troughing during fragment translation and screw fixation intraoperatively. Radiographs of lateral view of the foot taken preoperatively and at the last follow-up showed that the mean thickness of the first metatarsal was 22.4 mm preoperatively and 21.6 mm at the last follow-up, with a mean difference of 0.8 mm. And no stress fracture was observed. Conclusion: To prevent troughing and stress fracture, a long oblique longitudinal cut, parallel to the first metatarsal plantar surface, was performed, making both ends of the proximal segment truncated cone-shape, and securing the strong bony strut of the proximal segment. No troughing or stress fracture was experienced with scarf osteotomy.

• Applied Microscopy
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• 제14권2호
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• pp.81-93
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• 1984

Structural differences in various divisions of the rabbit colon were investigated using light and scanning electron microscopy. For light microscopic study, various Portions of the colon from seven rabbits (2.5 kg body weight) were fixed in 10% neutral buffered formalin, and paraffin sections were stained with hematoxylin-eosin. Tissues for scanning electron microscopy were fixed in 1% glutaraldehyde-1.5% paraformaldehyde and postfixed in 1% $OsO_4$, dehydrated to 100% alcohol, transfered to isoamilacetate and dried by the critical point method. Subsequently, specimens were coated with gold and viewed with a JSM-35C scanning electron microscope. The colon displays a morphological diversity along its proximo-distal axis. Five regions can be discerned based on the macroscopic and microscopic characteristics. 1) The first segment immediately distal to the cecocolical junction possessing three teniae is approximately 5 cm ($4{\sim}6cm$) in length, and displays irregular folds of the mucosa oriented transversely similar to those of the cecum. 2) The second segment possessing three teniae is about 7 cm ($5{\sim}8cm$) in length, and is characterized by the papilla-like protrusions on the mucosal surface. 3) The third segment, possessing a single tenia is about 16 cm ($12{\sim}20cm$) in length, and also displays the papilla-like protrusions similar to the aforegoing segment. 4) Fusus coli, approximately 4 cm ($3{\sim}5cm$) in length, is free of teniae and exhibits longitudinal folds on the mucosal surface. These four portions together constitute the proximal colon. 5) The distal colon reaches a length of about 58 cm ($53{\sim}55cm$) and shows a pattern of surface irregularities with minor ridges on the mucosal folds.

• Archives of Reconstructive Microsurgery
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• 제10권1호
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• pp.12-17
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• 2001

Recovery of nerve injury is conditioned by various factors including physical state, injured site, cause of injury, and neurorrhaphy Many researchers have reported on regeneration of nerve using end to side neurorrhaphy. The purpose of this study was to examine regeneration of nerve in various conditioned side to side neurorrhaphy. Total of 25 male Sprague-Dawley rats weighing 220 to 250 gm were divided into five groups of five rats each. The group 1, sham group, composed of dissection only without nerve transaction. The group 2, control group, composed of nerve division only without neurorrhaphy or sural nerve graft. The group 3 composed of one segmental sural nerve graft between the tibial and peroneal nerve after division. Group 4 had two segment graft, and the group 5 with three segment graft, each segment being 6mm long and 5 mm apart. The side to side neurorrhaphy was performed between peroneal nerve and tibial nerve using segmental sural nerve graft in rats. We exposed the sciatic nerve, tibial nerve, peroneal nerve, and sural nerve on left side with prone position. The peroneal nerve was cut on the bifurcation site from tibial nerve and the side to side epineurial neurorrhaphy was performed between peroneal nerve and tibial nerve through 6 mm sural nerve segment graft with 11-0 nylon under operating microscope. The electromyography and the weight from ipsilateral tibialis anterior muscle was performed at one month after neurorrhaphy Peroneal and tibial nerve was examined at distal and proximal to the neurorrhaphy site by methylene blue stain under light microscope for histologic appearance. The number of nerve fibers were counted using the image analyzer. Statistically, both in electromyography and number of nerve fibers, the differences in values between the groups were significant.

• 대한치과보철학회지
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• 제21권1호
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• pp.67-72
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• 1983

Path of insertion(1) can be defined that the direction of movement of an appliance from the point of initial contact of its rigid parts with the supporting teeth to the place of final rest. Krol(2) described that in the conventional path of insertion, all the rests are seated more or less simultaneously but in the use of the rotational path one segment of the partial denture is seated first then the remainder of the prosthesis is rotated into position. The rotational path of insertion is limited primarily to the tooth borne prosthesis. Its great advantages are the elimination of anterior clasps to improve ethetic and reduction of tooth coverage to minimize plaque accumulation. Either a rigid minor connector or proximal plate provides retention through its intimate contact with a proximal tooth surface below the height of contour as indicated at a o-degree tilt. A specially designed rest in conjunction with this retentive component satisfies the basic requirements of clasp design. The purpose of this study was a clinical evaluation of rotational path removable partial dentures. Author delivered rotational path removable partial dentures to three different cases of patients and evaluated function of the dentures, difficulties of removal and insertion of the dentures and supporting structures of the abutment teeth by means of clinical and X-ray examinations for eighteen months. According to the examination data author came to the conclusion that the prognosis of the rotational path removable partial dentures was excellent.