1.EFFECTS OF ELECTROLYTE CONCENTRATION AND ETCHING TIME ON SURFACE ROUGHNESS OF NI-CR-BE ALLOY.
Jae Woong HEO ; Young Chan JEON ; Chang Mo JEONG ; Chang Sub LIM
The Journal of Korean Academy of Prosthodontics 2000;38(2):178-190
The purpose of this study was to evaluate the surface roughness of Ni-Cr-Be alloy(Verabond ~, Aalba Dent Inc. USA) according to electrolyte concentration and etching time. Total of 150 metal specimens (12x 10 X 1.5mm) composed of 5 polisded specimens, 5 sandblasted specimens, 140 etched specimens were prepared. Etched groups were divided into 28 groups by the HC1O4 con= centrations(10, 30, 50, 70%) and etching times(15, 30, 60, 120, 180, 240, 300 seconds). The mean surface roughness(Ra) and the etching depth were measured with Optical 3-dimensional surface roughness measuring machine(Accura 1500M, Intek Engineering Co., Korea) and observed under SEM. The results obtaind were as follows 1. Surface roughness(Ra) and etching depth were affected by the order of etching time, electrolyte concentration, and their interaction (NO.05) . 2. Surface roughness(Ra) and etching depth were increased with etching time in 10%, 30% electrolyte concentrations, but they had no significant difference with etching time in 70%(P<0.05). 3. Surface roughness(Ra) and etching depth decreased in the order of 30, 10, 50, 70% electrolyte concentrations from 120 seconds etching time(p<0.05). 4. The remarkable morphologic changes in etched surface were observed along the grain boundaries in 15, 30 seconds of 10%, 30% concentrations and the morphologic changes could be denoted in the grains themselves as well as along the boundaries with the lapse of time. Even though the noticeable morphologic changes also took place in etched surface with 50% concentration, the degree of changes were less than that of changes with 10%, 30%. However, there were little morphologic changes with 70% concentration regardless of etching time. 5. Surface roughness(Ra) of sandblasting group with 50um A1203 had no significant difference with 30%-30 seconds etched group(p<0.05).
Alloys*
;
Edible Grain
2.Generalized Myasthenia Gravis with Spasmodic Dysphonia.
Woo Chan CHOI ; Sung Jae HEO ; Jin Sung PARK
Journal of the Korean Neurological Association 2016;34(2):138-141
Myasthenia gravis (MG) is an autoimmune disease that affects neuromuscular junctions and usually manifests with muscle weakness that exhibits diurnal variability. However, MG can present with atypical symptoms, including very rarely cases presenting with a flaccid type of dysphonia. We report the first case of spasmodic dysphonia with a final diagnosis of generalized MG, which occurred in a 32-year-old female.
Adult
;
Autoimmune Diseases
;
Diagnosis
;
Dysphonia*
;
Female
;
Humans
;
Muscle Weakness
;
Myasthenia Gravis*
;
Neuromuscular Junction
;
Voice Quality
3.A Morphometric Study of the Obturator Nerve around the Obturator Foramen.
Se Yeong JO ; Jae Chil CHANG ; Hack Gun BAE ; Jae Sang OH ; Juneyoung HEO ; Jae Chan HWANG
Journal of Korean Neurosurgical Society 2016;59(3):282-286
OBJECTIVE: Obturator neuropathy is a rare condition. Many neurosurgeons are unfamiliar with the obturator nerve anatomy. The purpose of this study was to define obturator nerve landmarks around the obturator foramen. METHODS: Fourteen cadavers were studied bilaterally to measure the distances from the nerve root to relevant anatomical landmarks near the obturator nerve, including the anterior superior iliac spine (ASIS), the pubic tubercle, the inguinal ligament, the femoral artery, and the adductor longus. RESULTS: The obturator nerve exits the obturator foramen and travels infero-medially between the adductors longus and brevis. The median distances from the obturator nerve exit zone (ONEZ) to the ASIS and pubic tubercle were 114 mm and 30 mm, respectively. The median horizontal and vertical distances between the pubic tubercle and the ONEZ were 17 mm and 27 mm, respectively. The shortest median distance from the ONEZ to the inguinal ligament was 19 mm. The median inguinal ligament lengths from the ASIS and the median pubic tubercle to the shortest point were 103 mm and 24 mm, respectively. The median obturator nerve lengths between the ONEZ and the adductor longus and femoral artery were 41 mm and 28 mm, respectively. CONCLUSION: The obturator nerve exits the foramen 17 mm and 27 mm on the horizontal and sagittal planes, respectively, from the pubic tubercle below the pectineus muscle. The shallowest area is approximately one-fifth medially from the inguinal ligament. This study will help improve the accuracy of obturator nerve surgeries to better establish therapeutic plans and decrease complications.
Cadaver
;
Femoral Artery
;
Ligaments
;
Obturator Nerve*
;
Spine
4.The Result of Mandible Fracture Fixations with Biodegradable Materials.
Jae Kwon WANG ; Seok Chan EUN ; Chan Yeong HEO ; Rong Min BAEK ; Kyung Won MINN
Journal of the Korean Cleft Palate-Craniofacial Association 2008;9(2):45-50
PURPOSE: Traditionally, titanium miniplate has been used for rigid fixation of mandible fractures. However, the limitations of metal plate have been reported such as hypersensitivity, interference with the cranio-facial growth of growing child, secondary bone resorption around the plate, foreign body reaction, declination of primary callus formation, and bone atrophy, and so forth. Recently, biodegradable miniplate has been introduced and used as an alternative to the metal plate despite of its lower strength. This study evaluated the usefulness and stability of biodegradable plate and screw for treatment of mandible fractures. METHODS: In this study, 61 patients(92 areas) diagnosed as mandible fracture in the last 2 years have been reviewed. We used titanium plate and screw in 32 patients, and biodegradable plate and screw(INION?) in 29 patients. Stability of plates and screws, bony healing process and its side effects were observed by clinical and radiographic assessment. RESULTS: In the titanium material group, one of malocclusion, two of mouth opening limitation, three of pain, three of palpation were shown. The plate of six patients involved in these complications were removed. In the biodegradable group, two of mouth opening limitation, two of pain, one of localized wound infection were shown and one plate was removed secondarily. CONCLUSION: There was no statistical difference between two groups in bony healing and complication rates. Biodegradable implants show efficient stability during initial bone healing and low side effects in long-term follow up periods.
Absorbable Implants
;
Atrophy
;
Bone Resorption
;
Bony Callus
;
Child
;
Follow-Up Studies
;
Foreign-Body Reaction
;
Fracture Fixation
;
Humans
;
Hypersensitivity
;
Malocclusion
;
Mandible
;
Mouth
;
Palpation
;
Titanium
;
Wound Infection
5.The Early Diagnosis of Herpetic Ke ratitis by Polymerase Chain Reaction.
Jae Yong HEO ; Su Jin KIM ; Jae Chan KIM ; Tae Won HAHN
Journal of the Korean Ophthalmological Society 2001;42(1):36-42
We evaluated the efficacy of polymerase chain reaction(PCR)in the early diagnosis of Herpes simplex virus keratitis(HSK). Among 47 patients(47 eyes), 25 patients were clinically herpetic keratitis and the others were other kinds of keratitis clinically. Tear film specimens were taken from 32 eyes and corneal scrapings from 21 eyes with suspicious herpetic keratitis and clinically incongrous with HSK. PCR for tear and corneal scraping was performed with using DNA primer. 67% of corneal scrapings and 19%tear samples of suspicious herpetic keratitis showed PCR positive. Tear samples from keratitis clinically incongruous with HSK were all PCR negative but 40%of corneal scrapings from these patients represented PCR positive. From these results, PCR is a rapid and effective tool for the early diagnosis of herpetic keratitis and especially useful in cases of nonspecific corneal lesion. However, for the accurate diagnosis of HSK, not only PCR results but also patient's history and corneal findings should be well evaluated.
Diagnosis
;
DNA
;
Early Diagnosis*
;
Humans
;
Keratitis
;
Keratitis, Herpetic
;
Polymerase Chain Reaction*
;
Simplexvirus
;
Tears
6.The Epidemiological and Clinical Characteristics of the Largest Outbreak of Enterohemorrhagic Escherichia coli in Korea
Namwoo HEO ; Jihee LEE ; Yeonkyung KIM ; Donghan LEE ; Seok-Jae HEO ; Yoon Soo PARK ; Jae-Won YUN ; Yong Chan KIM
Journal of Korean Medical Science 2023;38(15):e117-
Background:
The largest outbreak of enterohemorrhagic Escherichia coli (EHEC) O157:H7 occurred at a preschool in South Korea from June 12 to 29, 2020. This study aimed to analyze the epidemiological and clinical characteristics of EHEC infection in this outbreak.
Methods:
Epidemiological investigation was performed on all 184 children and 19 workers at the preschool using a standard questionnaire to assess symptoms, food intake, attendance, and special activity history. Pulsed-field gel electrophoresis analysis of confirmed cases was performed to determine genetic relevance.
Results:
During this outbreak, 103 children were affected, whereas only one infection was identified in adults. Of the 103 pediatric patients, 85 had symptoms (82.5%), including diarrhea, abdominal pain, bloody stool, fever, and vomiting. Thirty-two patients (31.1%) were hospitalized, 15 (14.6%) were diagnosed with hemolytic uremic syndrome, and 4 (3.9%) received dialysis treatment. Pulsed-field gel electrophoresis analysis identified 4 genotypes with high genetic relevance (92.3%). Epidemiological investigation revealed that this outbreak might have occurred from ingesting foods stored in a refrigerator with a constant temperature above 10°C, which was conducive to bacterial growth. Despite several measures after outbreak recognition, new infections continued to appear. Therefore, the preschool was forced to close on June 19 to prevent further person-to-person transmission.
Conclusion
Our findings from the response to the largest outbreak will help prepare countermeasures against future EHEC outbreak.
7.Effects of Polydeoxyribonucleotide in the Treatment of Pressure Ulcers.
Jung Yoon KIM ; Chang Sik PAK ; Ji Hoon PARK ; Jae Hoon JEONG ; Chan Yeong HEO
Journal of Korean Medical Science 2014;29(Suppl 3):S222-S227
This study aimed to examine the positive effects of polydeoxyribonucleotide (PDRN) on the wound-healing process in pressure ulcers. In this randomized controlled trial, the effects of PDRN were compared over time between an experimental group (n=11) and a control group (n=12). The former was administered the same dose of PDRN intramuscularly (1 ampule, 3 mL, 5.625 mg, for 5 days) for 2 weeks and perilesionally (1 ampule, 3 mL, 5.625 mg, twice a week) for 4 weeks. The primary endpoint for determining efficacy was wound healing in the pressure ulcers, which was reflected by the wound surface area determined using VISITRAK Digital (Smith & Nephew, Largo, FL). The secondary endpoint was the pressure ulcer scale for healing score, determined using pressure ulcer scale for healing (PUSH Tool 3.0 developed by the National Pressure Ulcer Advisory Panel). After the 4-week treatment period, PDRN therapy was found to significantly reduce the wound size and PUSH score, without adverse effect during the treatment. The findings indicate that PDRN can positively modify the wound healing process in pressure ulcers, and its use could improve the clinical outcomes of patients and lower the need for additional therapies or hospital stay.
Adolescent
;
Adult
;
Aged
;
Aged, 80 and over
;
Female
;
Humans
;
Injections, Intramuscular
;
Male
;
Middle Aged
;
Polydeoxyribonucleotides/*therapeutic use
;
Pressure Ulcer/*drug therapy
;
Treatment Outcome
;
Wound Healing/*drug effects
;
Young Adult
8.Pulsatile GnRH therapy in male patients with hypogonadotropic hypogonadism.
Ki Hyun PARK ; Yong Seok JEE ; Byung Seok LEE ; Dong Jae CHO ; Chan Ho SONG ; Moo Sang LEE ; Hyung Ki CHOI ; Hyun Chul LEE ; Kab Beom HEO
Korean Journal of Fertility and Sterility 1992;19(1):81-85
No abstract available.
Gonadotropin-Releasing Hormone*
;
Humans
;
Hypogonadism*
;
Male*
9.Two Cases of Spontaneous Cerebrospinal Fluid Rhinorrhea by Idiopathic Bony Defects.
Jun Young HEO ; Sung Jae YOUN ; Soo Chan PARK ; Jung Soo KIM
Korean Journal of Otolaryngology - Head and Neck Surgery 2009;52(1):93-97
Cerebrospinal fluid rhinorrhea can be caused by head trauma, brain or sinus surgery or neoplastic sinonasal disease. In addition, CSF rhinorrhea may develop spontaneously in some cases. We experienced two cases of spontaneous CSF rhinorrhea caused by idiopathic bony defect. The first case was a 47-year old female who complained of a persistent rhinorrhea for 2 months without surgical or traumatic history. The second case was a 40-year old female. Having no surgical or traumatic history, she also suffered from a persistent rhinorrhea for thirteen years. For diagnosis of CSF rhinorrhea, we carried out endoscopic examination, glucose test of rhinorrhea, computed tomograph, magnetic resonance imaging and (99m)Tc-DTPA cisternography. We found bony defect in the cribriform plate of the two cases. Patients were treated successfully with endoscopic approach. Leak sites were repaired with free graft materials. There has not been any recurrence or complications since the endoscopic closure.
Brain
;
Cerebrospinal Fluid Rhinorrhea
;
Craniocerebral Trauma
;
Ethmoid Bone
;
Female
;
Glucose
;
Humans
;
Magnetic Resonance Imaging
;
Recurrence
;
Transplants
10.Acellular dermal matrix and bone cement sandwich technique for chest wall reconstruction
Chan Yeong HEO ; Byungkwon KANG ; Jae Hoon JEONG ; Kwhanmien KIM ; Yujin MYUNG
Archives of Plastic Surgery 2022;49(1):25-28
The authors performed rigid reconstruction using the sandwich technique for full-thickness chest wall defects by using two layers of acellular dermal matrix and bone cement. We assessed six patients who underwent chest wall reconstruction. Reconstruction was performed by sandwiching bone cement between two layers of acellular dermal matrix. In all patients, there was no defect of the overlying soft tissue, and primary closure was performed for external wounds. The average follow-up period was 4 years (range, 2–8 years). No major complications were noted. The sandwich technique can serve as an efficient and safe option for chest wall reconstruction.