1.MECHANICAL PROPERTIES OF TITANIUM CONNECTORS TREATED BY VARIOUS WELDING TECHNIQUES.
Soo Young LEE ; Ik Tae CHANG ; Seong Joo HEO ; Soon Ho YIM
The Journal of Korean Academy of Prosthodontics 1999;37(5):545-566
The use of pure titanium and titanium alloys have been increased recently in fixed, removable prosthodontics and implant fields as a framework. But when they were used for superstructures of implant of metal framework of removable prosthesis, welding is necessary to reconnect the fracture site to control the casting distortions. To overcome the difficulties in soldering the titanium due to high oxidation property, much effort have been devoted. In this study, some of mechanical properties were compared between pure titanium and Ti-6Al-4V alloy by usingl aser welding, electron beam welding technique and tungsten arc welding. Mechanical properties such as tensile strength, yield strength, elongation and microhardness were measured. And, in order to compare the effect of welding site and surrounding metal tissue according to the welding condition, SEM photographs were taken an element distribution was observed by Wave Dispersion Spectroscopy. Through analyses of the data, following results were obtained; 1. In items such as tensile strength, yield strength and elongation according to the welding techniques of pure titanium, only tungsten arc welded group showed significant lower value than other groups(P<0.05). 2. In items such as tensile strength and yield strength according to the welding techniques of Ti-6Al-4V alloy, control group and tungsten arc welded group showed significant difference among all the groups(P<0.05). 3. Ti-6Al-4V alloy exhibited significantly greater elongation than control group when the laser welding method and electron beam welding method were used, and elongation showed increasing tendency. 4. Pure titanium specimens exhibited increasing tendency of microhardness regardless of the welding technique applied, and especially tungsten arc welded group demonstrated a great increase of microhardness than parent metal. 5. There was no hardness change in laser welded group and electron bean welded group of Ti-6Al-4V ally, but in tungsten arc welded group, hardness changed greatly from parent metal to weld seam. 6. Through the metallographic examination and scanning electron microscopy, laser welding caused central fusion and recristallizations were formed and tungsten arc welding caused localized fusion to 0.3-0.7mm from the surface.
Alloys
;
Hardness
;
Humans
;
Microscopy, Electron, Scanning
;
Parents
;
Prostheses and Implants
;
Prosthodontics
;
Spectrum Analysis
;
Tensile Strength
;
Titanium*
;
Tungsten
;
Welding*
2.Effect of German chamomile oil application on alleviating atopic dermatitis-like immune alterations in mice.
Soon Hee LEE ; Yong HEO ; Young Chul KIM
Journal of Veterinary Science 2010;11(1):35-41
Historically, German chamomile (GC) oil has been used for treatment of skin disorders. BALB/c mice were sensitized twice a week with 100 microL of 1% 2,4-dinitrochlorobenzene (DNCB) and challenged twice the following week with 100 microliter of 0.2% DNCB for atopic dermatitis induction. Thereafter, 3% GC oil was applied daily (70 microliter, 6 times week) on the dorsal skin for 4 weeks. Saline or jojoba oil was used for the control mice. Blood was collected after second DNCB challenge, and at 2 and 4 weeks after initiating oil application. Serum IgE levels were significantly lowered in the GC oil application group at the end of the 4-week application period. The GC oil application for 4 weeks resulted in reduction in serum IgG1 level compared with that after 2-week application. The GC oil application group showed a significantly lower serum histamine level than the control group 2 weeks after oil application. Scratching frequency of the GC oil application group was significantly lower than either control groups. This study is to demonstrate GC oil's immunoregulatory potential for alleviating atopic dermatitis through influencing of Th2 cell activation.
Animals
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Behavior, Animal/drug effects
;
Chamomile/*immunology
;
Dermatitis, Atopic/drug therapy/*immunology
;
Disease Models, Animal
;
Histamine/blood
;
Immunoglobulin E/blood
;
Immunoglobulin G/blood
;
Interleukin-4/analysis
;
Male
;
Matricaria/*immunology
;
Mice
;
Mice, Inbred BALB C
;
Phytotherapy/*methods
;
Specific Pathogen-Free Organisms
;
Th2 Cells/*immunology
3.Relationship between Allergen Sensitization and Frequency of Asthma in Preschool Atopic Dermatitis Children.
Yoon Jeong SONG ; Soon Young HEO ; Im Ju KANG
Pediatric Allergy and Respiratory Disease 2006;16(3):216-224
PURPOSE: Atopic dermatitis is affected by genetic and environmental factors. Bronchial asthma often develops in atopic dermatitis children. Allergen sensitization may affect the frequency of asthma in preschool atopic dermatitis children. So, we performed this study to know the relationship between allergen sensitization and the frequency of asthma in preschool atopic dermatitis children. METHODS: Three-hundred twelve of the children with atopic dermatitis in preschool aged children were divided into 3 groups;
4.Successful Management with Vincristine after Failure of Prednisolone Therapy for Diffuse Neonatal Hemangiomatosis.
Hak Sung LEE ; Soon Young HEO ; Won Duck KIM
Korean Journal of Pediatrics 2005;48(9):1004-1008
Hemangiomas are the most common benign tumors of infancy. Fifteen to 30% of these patients have multiple hemangiomas. Diffuse neonatal hemangiomatosis (DNH) is a disease that often has a fatal outcome if left untreated, and is characterized by multiple cutaneous and visceral hemangiomas. Corticosteroids are the commonly accepted first line treatment, but if no effect is seen, further treatment is required such as interferon, surgical excision, embolization and radiotherapy. Interferon is effective, but the neurologic sequela including spastic diplegia can be a complication. We experienced a case of DHN in a neonate. In this case, the baby presented with multiple cutaneous and visceral hemangiomas with Kasabach-Merritt syndrome (KMS) that included thrombocytopenia and consumptive coagulophthy. The baby was successfully treated with vincristine after the failure of steroid therapy.
Adrenal Cortex Hormones
;
Cerebral Palsy
;
Fatal Outcome
;
Hemangioma
;
Humans
;
Infant, Newborn
;
Interferons
;
Kasabach-Merritt Syndrome
;
Prednisolone*
;
Radiotherapy
;
Thrombocytopenia
;
Vincristine*
6.A Case of Myotubular Myopathy.
Pil Soon YANG ; Jae Ho YOO ; Bong Keun CHOI ; Young Ah LEE ; Ki Young HEO ; Kyu Geun HWANG
Journal of the Korean Society of Neonatology 2002;9(2):226-230
The term myotubular myopathy (MTM) implies a maturational arrest of fetal muscle during the myotubular stage of development at 8-15 weeks of gestation. Characteristic muscle histopathology consists of small hypotrophic muscle fibers with centrally placed nuclei and a surrounding clear area devoid of myofibrils. X-linked recessive inheritance is the most common trait. Autosomal recessive and autosomal dominant forms are less frequently reported. The clinical diagnostic criterion for X-linked MTM has relied on a positive family history and the demonstration of the presence of characteristic biopsy findings from affected male subjects. Additional features may include perinatal onset, severe hypotonia, respiratory failure, dysphagia, thin ribs, contractures of the hips or knees, puffy eyelids and ophthalmoplegia. The prognosis is often fatal, and most patients die within the first year of life from respiratory failure. The authors report a case of presumed X-linked MTM with severe hypotonia, muscle weakness and respiratory failure at birth.
Biopsy
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Contracture
;
Deglutition Disorders
;
Eyelids
;
Hip
;
Humans
;
Knee
;
Male
;
Muscle Hypotonia
;
Myofibrils
;
Myopathies, Structural, Congenital*
;
Ophthalmoplegia
;
Parturition
;
Pregnancy
;
Prognosis
;
Respiratory Insufficiency
;
Ribs
;
Wills
7.Response of osteoblast-like cells on titanium surface treatment.
Hyun Ki ROH ; Seong Joo HEO ; Ik Tae CHANG ; Jai Young KOAK ; Jong Hyun HAN ; Yong Sik KIM ; Soon Ho YIM
The Journal of Korean Academy of Prosthodontics 2003;41(6):699-713
Statement of problem. Titanium is the most important material for biomedical and dental implants because of their high corrosion resistance and good biocompatibility. These beneficial properties are due to a protective passive oxide film that spontaneously forms on the surface. Purpose. The purpose of this study was to evaluate the responses of osteoblast-like cells on different surface treatments on Ti discs. Material and Methods. Group 1 represented the machined surface with no treatment. Group 2 surfaces were sandblasted with 50microm Al2O3 under 5 kgf/cm2 of pressure. Groups 3 and 4 were sandblasted under the same conditions. The samples were treated on a titanium oxide surface with reactive sputter depositioning and thermal oxidation at 600degree C (Group 3) and 800degree C (Group 4) for one hour in an oxygen environment. The chemical composition and microtopography were analyzed by XRD, XPS, SEM and optical interferometer. The stability of TiO2 layer was studied by potentiodynamic curve. To evaluate cell response, osteoblast extracted from femoral bone marrow of young adult rat were cultured for cell attachment, proliferation and morphology on each titanium discs. Results and Conclusion. The results were as follows : 1.Surface roughness values were, from the lowest to the highest, machined group, 800degree C thermal oxidation group, 600degree C thermal oxidation group and blasted group. The Ra value of blasted group was significantly higher than that of 800degree C thermal oxidation group (P=0.003), which was not different from that of 600degree C thermal oxidation group (P<0.05). 2. The degree of cell attachment was highest in the 600degree C thermal oxidation group after four and eight hours (P<0.05), but after 24 hours, there was no difference among the groups (P>0.05). 3. The level of cell proliferation showed no difference among the groups after one day, three days, and seven days (P>0.05). 4. The morphology and arrangement of the cells varied with surface roughness of the discs.
Animals
;
Bone Marrow
;
Cell Proliferation
;
Corrosion
;
Dental Implants
;
Humans
;
Osteoblasts
;
Oxygen
;
Rats
;
Titanium*
;
Young Adult
8.The study on the removal torque of the diamond like carbon coated titanium abutment screws.
Jai young KOAK ; Seong Joo HEO ; Ik Tae CHANG ; Soon Ho YIM ; Jong Yeop LEE ; Kwang Ryeol LEE
The Journal of Korean Academy of Prosthodontics 2003;41(2):128-135
STATEMENT OF PROBLEM: Implant screw loosening remains a problem in implant prosthodontics. Some abutment screws with treated surfaces were introduced to prevent screw loosening and to increase preload. DLC(Diamond Like Carbon) film has similar properties on hardness, wear resistance, chemical stability, biocompatibility as real diamond materials. PURPOSE: The purpose of this study was to investigate the effect of lubricant layer on abutment screw and to discriminate more effective method between soft lubricant and hard lubricant to prevent screw loosening. MATERIAL AND METHOD: In this study, 1mum thickness DLC was used as protective, lubricating layer of titanium screws and 3 times removal torque was measured on the abutment screws to investigate the difference in 10 coated and 10 non-coated abutment screws. RESULTS: The results indicated that the implants with DLC coating group were not more resistant to the applied force in screw loosening. At 32Ncm, the 3 times removal torque in DLC group were 27.7+/-2.89, 25.85+/-2.35 and 26.2+/-2.57. The removal torque in no-coated abutment screws were 27.85+/-4.23, 27.35+/-2.81 and 27.9+/-2.31, respectively. CONCLUSION: The lubricant layer used in this study was Diamond Like Carbon(DLC) and it have a properties of hard and stable layer. The DLC coating layer was hard enough to prevent distortion of screws in the repeated unscrewing procedure in clinical situation. The reduced friction coefficient in hard DLC layer was not effective to prevent screw loosening.
Carbon*
;
Diamond*
;
Friction
;
Hardness
;
Prosthodontics
;
Titanium*
;
Torque*
9.High-dose Intravenous Immune Globulin Retreatment in Kawasaki Disease.
So Yun SHIM ; Mi Young HEO ; Hae Soon KIM ; Se Jung SONH
Journal of the Korean Pediatric Society 2002;45(10):1273-1277
PURPOSE: To determine clinical features, laboratory findings and cardiac abnormalities of high- dose immune globulin(IVIG) retreatment in patients with Kawasaki disease, and to report effectiveness of retreatment. METHODS: Retrospective study of 174 children diagnosed with Kawasaki disease at Ewha Mokdong hospital from March, 1999 to July, 2001. RESULTS: Twenty(11.5%) of 174 patients were retreated with high-dose IVIG. After this, only two patients(1.1%) did not respond to IVIG retreatment. Patients with failure to respond to initial IVIG did not differ from the patients who responded to a single course of IVIG in sex, age, days of fever at initial IVIG and clinical characteristics. Compared with responders with single IVIG treatment, the patients who were retreated had significantly lower albumin(3.7 vs 3.4 g/dL, P< 0.05), higher ALT(118.2 vs 229.3 U/L, P<0.05) and CRP(8.9 vs 13.3 mg/dL, P<0.05). On echocardiography, patients who recieved IVIG retreatment were significantly more likely to have caronary abnormalities(45.0% vs 13.6%, P<0.05). CONCLUSION: Retratment with IVIG for persistent or recurrent fever was safe and effective.
Child
;
Echocardiography
;
Fever
;
Humans
;
Immunoglobulins, Intravenous*
;
Mucocutaneous Lymph Node Syndrome*
;
Retreatment*
;
Retrospective Studies
10.Treatment of advanced gastric cancer with 5-fluorouracil, etoposide and cisplatin(FEP).
Joung Soon JANG ; Young Hyuk IM ; Sung Soo YOON ; Jae Yong LEE ; Dae Seog HEO ; Yung Jue BANG ; Noe Kyeong KIM
Journal of the Korean Cancer Association 1992;24(5):702-707
No abstract available.
Etoposide*
;
Fluorouracil*
;
Stomach Neoplasms*