1.Three-dimensional stress analysis of implant systems in the mandibular bone with various abutment types and loading conditions.
Ha Shik SHIN ; Heoung Jae CHUN ; Chong Hyun HAN ; Soo Hong LEE
The Journal of Korean Academy of Prosthodontics 2003;41(5):617-625
STATEMENT OF PROBLEM: There are many studies focused on the effect of shape of fixtures on stress distribution in the mandibular bone. However, there are no studies focused on the effect of the abutment types on stress distribution in mandibular bone. PURPOSE: The purpose of this study is to investigate the effect of three different abutment types on the stress distributions in the mandibular bone due to various loads by performing finite element analysis. Material and method : Three different implant systems produced by Warantec (Seoul, Korea) were modeled to study the effect of abutment types on the stress distribution in the mandibular bone. The three implant systems are classified into oneplant (Oneplant, OP-TH-S11.5), internal implant (Inplant, IO-S11.5) and external implant (Hexplant, EH-S11.5). All abutments were made of titanium grade ELI, and all fixtures were made of titanium grade IV. The mandibular bone used in this study is constituted of compact and spongeous bone assumed to be homogeneous, isotropic and linearly elastic. A comparative study of stress distributions in the mandibular bone with three different types of abutment was conducted. RESULTS: It was found that the types of abutments have significant influence on the stress distribution in the mandibular bone. It was due to difference in the load transfer mechanism and the size of contact area between abutment and fixture. Also the maximum effective stress in the mandibular bone was increased with the increase of inclination angle of load. CONCLUSION: It was concluded that the maximum effective stress in the bone by the internal implant was the lowest among the maximum effective stresses by other two types.
Finite Element Analysis
;
Titanium
2.Clinical observation of acute drug intoxications.
Jun Ha CHUN ; Kyung Chul SHIN ; Jin Hong CHUNG ; Chong Ki LEE ; Bong Sup SHIM ; Hyun Woo LEE
Yeungnam University Journal of Medicine 1991;8(2):164-173
Clinical observations were made on 349 cases of acute drug intoxication who were visited to emergency room of Yeungnam University Hospital during recent 7 years from January 1984 to December 1990. The following results were obtained. 1) Total number of cases of acute drug intoxication was 349 which was 0.39% of the total patients of the emergency room during the same period. 2) The ratio of male to female was 1.1:1. The age incidence was highest in the third decade (26.7%). The monthly incidence was highest in May. Higher frequency was observed in summer season. 3) The most common drug of the intoxication was pesticides and herbicides (71.9%), the remainders were miscellaneous drugs (11.2%), sedatives (7.7%), rodenticides (6.3%) and unknown drug (3.2%) in orders. 4) The most common cause of drug intoxication was suicide (69.1%) and the others were accident, unknown cause, intention in orders. 5) Main clinical manifestations were the impairment of consciousness, nausea, vomiting and convulsion. Physical examination revealed increased pulses, increased blood pressure, miosis of the pupil and sweating. Above symptoms and signs were more prominent in pesticide intoxication. Leukocytosis, glycosuria and abnormal LFT were common findings in acute intoxications. 6) The complications were developed in 18.3% among 349 cases and the most common complication was respiratory failure, pneumonia, cardiovascular collapse and pulmonary edema in orders. 7) Overall mortality rate was 8.3% of total cases and mortality rate was highest in herbicide intoxication (22.2%).
Blood Pressure
;
Consciousness
;
Emergency Service, Hospital
;
Female
;
Glycosuria
;
Herbicides
;
Humans
;
Hypnotics and Sedatives
;
Incidence
;
Intention
;
Leukocytosis
;
Male
;
Miosis
;
Mortality
;
Nausea
;
Pesticides
;
Physical Examination
;
Pneumonia
;
Pulmonary Edema
;
Pupil
;
Respiratory Insufficiency
;
Rodenticides
;
Seasons
;
Seizures
;
Suicide
;
Sweat
;
Sweating
;
Vomiting
3.The Effect of 5-FU and Radiation on A549 Cells In Vitro.
Myung Za LEE ; Ha Chong CHUN ; Won Young LEE
Journal of the Korean Society for Therapeutic Radiology 1989;7(1):1-14
Effects of ionizing radiation alone and combined with chemotherapy on tumor growth and it's clonal specificity Monitored by changes in distribution of chromosome number were studies in A549 cell line originated from human adenocarcinoma of the lung. Radiation (300 rad, 600 rad and 900 rad) were delivered with or without 5-FU. Forty eight hours later, 57.5% of growth inhibition of cell was Seen in cells treated with 5-FU concentration of 0.47g/ml for 24 hr exposure. Cell survival carves after radiation with and without 5-FU were made. Chromosomal analysis of cells in metaphase in control, and in cells treated with 300 rad of radiation, or 0.47g/ml of 5-FU treatment, and combined treatment of cloth were 77ne to examine the changes in ploidy and number of chromosome. Radiation combined with 5-FU enhanced growth inhibition of A549 cells. However, no evidence of synergegic effects in growth inhibition was observed in the cells treated with the combination therapy. Pattern of chromosomal distribution of survived cells were shifted from hyperploidy to hypoploidy by single dose of radiation(300 rad). As radiation dose increased a large number of hypoploidy cells were observed. Following treatment of cells with 5-FU, chomosomal distribution of survived cells were also shifted to hypodiploidy, which were seen in cells treated with radiation. The cell treated with 5-FU and followed by radiation within 24 hrs had cell with increased number of hypodiploidy cells. Almost same type of chromosomal changes were reproduced in cells treated with combined treatment with radiation and 5-FU. Minor differences were that cells with fewer number of chromosome were more frequent in cells treated with combined therapy. Further increase in cells of hypoploidy(93%) having 1~10 chromosome were induced by additional radiation. Therefore, the enhanced therapeutic effect of 5-FU combined with radiation of A549 cells appeared to be additive rather than synergistic.
Adenocarcinoma
;
Cell Line
;
Cell Survival
;
Drug Therapy
;
Fluorouracil*
;
Humans
;
Lung
;
Metaphase
;
Ploidies
;
Population Characteristics
;
Radiation, Ionizing
;
Sensitivity and Specificity
4.Analysis of Factors Related to Neurological Deficit in Thoracolumbar Fractures.
Joonho CHUNG ; Seung Hwan YOON ; Hyung Chun PARK ; Chong Oon PARK ; Eun Young KIM ; Yoon HA
Journal of Korean Neurosurgical Society 2007;41(1):1-6
OBJECTIVE: The purpose of this study is to determine the factors that have effects on the neurological deficit in the patients with thoracolumbar fracture. METHODS: Forty-eight patients were included. Cause of injury, type of injury, time interval, combined injury, kyphotic angle, spinal canal compromise, sagittal diameter, the most narrow sagittal diameter, transverse diameter, the most narrow transverse diameter, and remained height of vertebra body were concerned as the factors. The patients with American Spinal Injury Association(ASIA) impairment scale grade A to D were considered as having neurology while others with ASIA grade E were considered to be without neurology. The patients with ASIA grade A were classified to paraplegia group and the patients with ASIA grade B to E were not thought to be paraplegia. Statistical analysis for these groups were performed. RESULTS: Spinal canal compromise (P<0.001) have correlation with neurological deficit. The most narrow sagittal diameter was smaller in the group with deficit than that in the group without deficit (P=0.004). Also, combined injury have correlation with neurology (P=0.028). Spinal canal compromise (P<0.001), sagittal diameter (P=0.032), the most narrow sagittal diameter (P=0.025), and Denis type (P<0.001) also have correlation with paraplegia. CONCLUSION: The factors of percentage of spinal canal compromise, the most narrow sagittal diameter, and combined injury are predictive of neurological deficit. The patients with paraplegia may be predicted by the factors such as type of injury, spinal canal compromise, sagittal diameter, the most narrow sagittal diameter, and Denis type.
Asia
;
Humans
;
Neurologic Manifestations
;
Neurology
;
Paraplegia
;
Spinal Canal
;
Spinal Fractures
;
Spinal Injuries
;
Spine
5.Clinical Investigation of Seizure Disorder Associated with Temporal Lobe Lesions.
Young KIM ; Jae Joong KIM ; Ho Kyu CHUN ; Sang Don LEE ; Kweon Beong CHAE ; Chong Oon PARK ; Young Soo HA
Journal of Korean Neurosurgical Society 1992;21(9):1102-1109
We evaluated the temporal lobe lesions in 24 patients who had various types of seizure as initial neurologic symptoms between 1987 and 1992. All patients were studied with radiologic and pathologic procedures. The types of seizure were classified with the International League Against Epilepsy classification. The results were as follows:The age of distribution of patients were 3 to 72 years old. The most common seizure type was generalized tonic-clonic and then complex partial, unclassified type, generalized absence and simple partial motor in order. The usual associated diseases were arachnoid cyst, abscess, blioblastoma multiforme, meningioma and temporal sclerosis. The most common location of the lesions was the inferomedial area in the temporal lobe. The maximal diameters of lesions were ranged from 7 to 78 mm(mean 36 mm) .
Abscess
;
Aged
;
Arachnoid
;
Classification
;
Epilepsy*
;
Humans
;
Meningioma
;
Neurologic Manifestations
;
Sclerosis
;
Seizures*
;
Temporal Lobe*
6.Expression of Jun and p53 Genes from the Brain of Rats Irradiated with 60Co gamma-ray.
Yong Sung LEE ; Myung Za LEE ; Ha Chung CHUN ; Chong Kyu WOO ; Jai Kyung KOH ; Yong Seok KIM
Journal of the Korean Society for Therapeutic Radiology 1996;14(4):265-280
Damage produced by radiation elicits a complex response in mammalian cells. Including growth rate changes and the induction of a variety of genes associated with growth control and apoptosis.At doses of 10,000 cGy or greater, the exposed indivisual was killed in a matter of minutes to a couple of days. With symptoms consistent with pathology of the central nervous system(CNS) including degenerative changes. The nature of the damege in irradiated cells underlies the unique hazads of ionizing radiation. Radiation injury CNS is a rare event in clinical medicine, but it is catastrophic for the patient in whom it occurs. The incidience of cerebral necrosis has been reportes as high as 16% for doses greater than 6,000 cGy.In this study, the effect of radiation on brain tissues was studied in vivo. Jun and p53 genes in the rat brain were induced by whole body irradiation of rat with 60Co in doses between 1 Gy and analyzed for expression analyses were done using 1.8 Kb & 0.8 Kb-pGEM-2-JUN/Eco RI/Pst I fragments, 2.0 Kb-php53B/Bam HI fragment and 1.1 Kb-pBluescript SK-ACTIN/Eco RI fragment as the digoxigenin or [alpha32P]dCTPlabeled probes for Jun, p53 and beta-actin genes, respectively.Jun gene seemed to be expressed near the threshold levels in 1 hour after irradiation of 60Co in dose less than 1 Gy and was expressed in maximum at 1 hour after irradiation of 60Co in dose of 30 Gy. Jun was expressed increasingly with time until 5 or 6 hours after irradiation of 60Co in dose of 1 Gy and 10 Gy . After irradition of 60Co in dose between 20 Gy and 100Gy, the expression of Jun was however increased to peak in 2 hours and decreased thereafter.P53 gene in this study also seemed to be expressed near the threshold levels in 1 hours after irradiation of 60Co in less than 1 Gy and was expressed in maximum and 6 hours after irradiation of 60Co in dose of 1 Gy. P53 was expressed increasingly with time until 5 or 6 hours after irradition of 60Co in dose between 1 Gy and 40 Gy. After irradition of 60Co in dose of 50 Gy and 100Gy. The expression of p53 was however increased in peak in 2 hours and decreased thereafter. The expression of Jun and p53 genes was not correlative in the brain tissue from rats.It seemed to be very important for the establishment of the optimum conditions for the animal studies relevant to the response of genes inducible on DNA damage to ionizing radiation in mammalian cells. But there are many limitations to the animal studies such as the ununiform patterns of gene expression from the tissue because of its complex compositions. It is necessary to overcome the limitations for development of in situ Northern analysis.
Actins
;
Animals
;
Brain*
;
Clinical Medicine
;
Digoxigenin
;
DNA Damage
;
Gamma Rays
;
Gene Expression
;
Genes, p53*
;
Humans
;
Necrosis
;
Pathology
;
Radiation Injuries
;
Radiation, Ionizing
;
Rats*
;
Whole-Body Irradiation
7.The Effects of Different Substrates on the Growth, Yield, and Nutritional Composition of Two Oyster Mushrooms (Pleurotus ostreatus and Pleurotus cystidiosus).
Ha Thi HOA ; Chun Li WANG ; Chong Ho WANG
Mycobiology 2015;43(4):423-434
The study was conducted to compare the effects of different agro-wastes on the growth, yield, and nutritional composition of oyster mushrooms Pleurotus ostreatus (PO) and Pleurotus cystidiosus (PC). Seven substrate formulas including sawdust (SD), corncob (CC), sugarcane bagasse (SB) alone and in combination of 80 : 20, 50 : 50 ratio between SD and CC, SD and SB were investigated. The results indicated that different substrate formulas gave a significant difference in total colonization period, characteristics of fruiting bodies, yield, biological efficiency (BE), nutritional composition and mineral contents of two oyster mushrooms PO and PC. The results showed that increasing CC and SB reduced C/N ratio, and enhanced some mineral contents (Ca, P, and Mg) of substrate formulas. The increased amount of CC and SB of substrate formulas enhanced protein, ash, mineral contents (Ca, K, Mg, Mn, and Zn) of fruiting bodies of both mushrooms. Substrates with 100% CC and 100% SB were the most suitable substrate formulas for cultivation of oyster mushrooms PO and PC in which they gave the highest values of cap diameter, stipe thickness, mushroom weight, yield, BE, protein, fiber, ash, mineral content (Ca, K, and Mg) and short stipe length. However, substrate formula 100% CC gave the slowest time for the first harvest of both mushrooms PO and PC (46.02 days and 64.24 days, respectively). It is also found that the C/N ratio of substrate formulas has close correlation with total colonization period, mushroom weight, yield, BE and protein content of mushroom PO and PC.
Agaricales
;
Colon
;
Fruit
;
Ostreidae*
;
Pleurotus*
;
Saccharum
8.Clinical Usefulness of 18F-FDG PET/CT in the Detection of Early Recurrence in Treated Cervical Cancer Patients with Unexplained Elevation of Serum Tumor Markers
Ari CHONG ; Jung Min HA ; Shin Young JEONG ; Ho Chun SONG ; Jung Joon MIN ; Hee Seung BOM ; Ho Sun CHOI
Chonnam Medical Journal 2013;49(1):20-26
We investigated the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for restaging of treated uterine cervix squamous cell cancer with tumor maker elevation that was not explained by other conventional evaluation. We enrolled 32 cases who underwent PET/CT for the restaging of treated cervical cancer with tumor marker elevation that was not explained by recent conventional evaluation. All enrolled cases had squamous cell carcinoma. Increased tumor markers included squamous cell carcinoma antigen (SCC Ag) and carcinoembryonic antigen (CEA). PET/CT findings were determined by pathologic confirmation or clinical follow-up. We compared PET/CT accuracy and clinical parameters including normalization of tumor markers in both the SCC Ag elevation group and the CEA elevation group. The sensitivity, specificity, positive predictive value, and negative predictive value of PET/CT in detecting recurrence were 100%, 83.3%, 82.4%, and 100%, respectively. Accuracy was significantly different between the SCC Ag elevation group and the CEA elevation group (p=0.0169). PET/CT with SCC Ag elevation was more accurate (100%) than PET/CT with CEA elevation (66.7%). Normalization of tumor markers was observed more often in the SCC Ag elevation group than in the CEA elevation group (p=0.0429). PET/CT showed high negative predictive value and sensitivity in the restaging of cervical cancer with unexplained tumor marker elevation. PET/CT was more accurate in patients with SCC Ag elevation than in those with CEA elevation.
Antigens, Neoplasm
;
Carcinoembryonic Antigen
;
Carcinoma, Squamous Cell
;
Cervix Uteri
;
Electrons
;
Female
;
Fluorodeoxyglucose F18
;
Follow-Up Studies
;
Humans
;
Neoplasms, Squamous Cell
;
Positron-Emission Tomography and Computed Tomography
;
Recurrence
;
Sensitivity and Specificity
;
Serpins
;
Biomarkers, Tumor
;
Uterine Cervical Neoplasms
9.Radiological Considerations of Posterior Cervical Lateral Mass Fixation Using Plate and Screw.
Seung Hwan YOON ; Hyoung Chun PARK ; Heon Seon PARK ; Eun Young KIM ; Yoon HA ; Chong Kweon CHONG ; Seung Min KIM ; Dae Cheol RIM
Yonsei Medical Journal 2004;45(3):406-412
The aim of this study is to determine whether the posterior cervical fusion methods with the plate-screw system applied to the lateral mass of cervical spine are radiologically safe to patients. The lateral cervical X-rays and CT scans were done on 40 normal adults without cervical problem. Based on Roy-Camille and Magerl's method, the theological trajectory of screw was shown on films and the parameters were measured. The study based on Roy-Camille's method showed less than one percent chance of injury on the facet joint and the mean depth of the screw to be 10.5+/-1.4mm. On the other hand, Magerl's method showed the mean depth of screw to be 11.9+/-1.5mm which is slightly larger than that of Roy-Camille's method and no chance of facet injury occurred. A reduced lateral angle of screw (19.6+/-3.5 degrees) performed with the concept based on Magerl's method resulted a longer depth of screw (13.5+/-2.1mm). Both Roy-Camille and Magerl's methods seemed to be radiologically safe to normal persons. However, the authors recommend the reduced lateral angle (19.6+/-3.5 degrees) of screw based on the Magerl's method more than an original Magerl's methods.
Adult
;
Bone Plates
;
Bone Screws
;
Cervical Vertebrae/*radiography/*surgery
;
Female
;
Human
;
Male
;
*Spinal Fusion
;
Support, Non-U.S. Gov't
;
Tomography, X-Ray Computed/*methods
10.Dysphagia due to Cervical Osteophytes: Case Report.
Ki Chan KIM ; Seung Hwan YOUN ; Hyung Chun PARK ; Hyun Sun PARK ; Eun Young KIM ; Byung Yoon CHUN ; Chong Oon PARK ; Young Soo HA
Journal of Korean Neurosurgical Society 1998;27(1):109-113
Forestier's disease, also known as diffuse idiopathic skeletal hyperostosis(DISH), is a rare condition. It frequently occurs in elderly men, and is mostly asymptomatic. Patients with severe involvement of the cervical spine may, however, develop dysphagia, dysphonia, dyspnea, and foreign body sensation. We decribe that one case of Forestier's disease with dysphagia, successfully treated by surgery, and also present a review the literature.
Aged
;
Deglutition Disorders*
;
Dysphonia
;
Dyspnea
;
Foreign Bodies
;
Humans
;
Hyperostosis, Diffuse Idiopathic Skeletal
;
Male
;
Osteophyte*
;
Sensation
;
Spine