Finite element analyses were performed to study effects on stress distribution generated in jaw bone for various shapes of dental implants: plateau type, plateau with small radius of curvature, triangular thread screw type in accordance with ISO regulations and square thread screw filleted with small radius partially. It was found that square thread screw filleted with small radius was more effective on stress distribution than other dental implants used in analyses. Additional analyses were performed on the implant with square thread screw filleted with small radius for verying design parameters, such as the width of thread end, the height of the thread of the implant and load direction, to determine the optimum dimensions of the implant. The highest stress concentration occurred at the region in jaw bone adjacent to the first thread of the implant. The maximum effective stress induced by a 15 degree oblique load of 100 N was twice as high as the maximum effective stress caused by an equal amount of vertical load. Stress distribution was more effective in the case when the width of thread end and the height of thread were p/2 and 0.46p, respectively, where p is the pitch of thread. At last, using tensile force calculated from the possible insert torque without breading bone thread, finite element analysis was performed on the implant to calculate pre-stress when the primary fixation of the implant was operated in jaw bone. The maximum effective stress was 136.8 MPa which proven to be safe.
Bread ; Dental Implants ; Finite Element Analysis ; Jaw ; Radius ; Social Control, Formal ; Torque

Posterior reversible encephalopathy syndrome (PRES) is a neurologic condition characterized by vasogenic edema on neuroimaging and is associated with the setting of severe hypertension, eclampsia, autoimmune disease, malignancy, and immunosuppressive drugs. We report on a 42 year-old female systemic lupus erythematous patient who presented altered consciousness, seizure, and visual disturbance after cyclophosphamide pulse therapy. Magnetic resonance imaging (MRI) showed multi-focal high signal intensity lesions in the parieto-occipital cortex bilaterally and in the subcortical white matter. Her condition was improved and her MRI lesions were resolved after aggressive blood pressure control and high-dose steroid treatment. It is possibly the first reported case of PRES in a patient with lupus, treated with cyclophosphamide pulse therapy during a nephritis flare in Korea.
Autoimmune Diseases ; Blood Pressure ; Consciousness ; Cyclophosphamide ; Eclampsia ; Edema ; Female ; Humans ; Hypertension ; Korea ; Lupus Erythematosus, Systemic ; Lupus Nephritis ; Magnetic Resonance Imaging ; Nephritis ; Neuroimaging ; Pregnancy ; Seizures

PURPOSE: It has been postulated that dopamine release in the striatum underlies the reinforcing properties of nicotine. Substantial evidence in the animal studies demonstrates that nicotine interacts with dopaminergic neuron and regulates the activation of the dopaminergic system. The aim of this study was to visualize the dopamine release by smoking in human brain using PET scan with [11C]raclopride. MATERIALS AND METHODS: Five male non-smokers or ex-smokers with an abstinence period longer than 1 year (mean age of 24.4+/-1.7 years) were enrolled in this study. [11C]raclopride, a dopamine D2 receptor radioligand, was administrated with bolus-plus- constant infusion. Dynamic PET was performed during 120 minutes (3x20s, 2x60s, 2x120s, 1x180s and 22x300s). Following the 50 minute-scanning, subjects smoked a cigarette containing 1 mg of nicotine while in the scanner. Blood samples for the measurement of plasma nicotine level were collected at 0, 5, 10, 15, 20, 25, 30, 45, 60, and 90 minute after smoking. Regions for striatal structures were drawn on the coronal summed PET images guided with co-registered MRI. Binding potential, calculated as (striatal-cerebellar) /cerebellar activity, was measured under equilibrium condition at baseline and smoking session. RESULTS: The mean decrease in binding potential of [11C]raclopride between the baseline and smoking in caudate head, anterior putamen and ventral striatum was 4.7 %, 4.0 % and 7.8 %, respectively. This indicated the striatal dopamine release by smoking. Of these, the reduction in binding potential in the ventral striatum was significantly correlated with the cumulated plasma level of the nicotine (Spearman's rho=0.9, p=0.04). CONCLUSION: These data demonstrate that in vivo imaging with [11C]raclopride PET could measure nicotine-induced dopamine release in the human brain, which has a significant positive correlation with the amount of nicotine administered by smoking.
Animals ; Basal Ganglia ; Brain ; Dopamine* ; Dopaminergic Neurons ; Head ; Humans ; Magnetic Resonance Imaging ; Male ; Nicotine ; Plasma ; Positron-Emission Tomography ; Putamen ; Receptors, Dopamine D2 ; Smoke ; Smoking ; Tobacco Products

PURPOSE: We conducted this study to assess the effect of oral application of bovine colostrum on the plasma endotoxin and TNF-alpha following the abdominal surgery. METHODS: 46 patients who underwent the abdominal surgery were evenly enrolled in a prospective, randomized, double blind and placebo-controlled study. The patients were preoperatively managed by oral application of 20 g of a bovine colostrums or placebo (nonfat dried milk) per a day for 3 days. In both groups, endotoxin was sequentially determined pre-, intra- and postoperatively by a modified limulus amebocyte lysate test. TNF-alpha and CRP were also measured. The clinical course was followed and compared in both groups. RESULTS: The colostrum group showed significantly lower level of endotoxin and TNF-alpha compared to the placebo group. CRP did not differ in both groups. Clinical event did not occur in both group until the discharge. Colostrum group tends to have a lower incidence of fever and leukocytosis without statistic significance. CONCLUSION: Prophylactic preoperative oral application of bovine colostrum lower the plasma level of perioperative endotoxin and TNF-alpha. Further studies were needed for the relation of clinical effect and preoperative oral application of bovine colostrum.
Colostrum* ; Endotoxemia* ; Fever ; Horseshoe Crabs ; Humans ; Incidence ; Leukocytosis ; Plasma ; Prospective Studies ; Tumor Necrosis Factor-alpha*

PURPOSE: Iron deficiency anemia (IDA) is one of the most common nutritional deficiencies in children on a weaning diet. We investigated weaning practices in infants and children, as well as their mothers' knowledge about weaning. METHODS: We investigated 129 children with IDA and 166 without IDA (aged 6-36 months) who had visited 10 university hospitals between March 2006 and July 2007. We investigated the hematologic values of both groups. A questionnaire on weaning was answered by the mothers of these children. RESULTS: The hematologic values in the IDA group showed a significant difference from those in the comparison group (P<0.05). Children who were solely breastfed until 6 months of age were 85%, 34% (P<0.05), and weaning was started by 6.3, 6.4 months, respectively (P>0.05). Rice gruel, boiled rice, and fruit juice accounted for approximately 8 0% of the starting foods in both groups (P>0.05). Only 40% of the children in the IDA group had a balanced diet within a month, versus 38% in the comparison group. In response to questions about the necessity of iron-fortified foods for breast-fed infants, less than 50% of mothers in both groups answered correctly. In the IDA group, 42% showed serum ferritin less than 10 ng/ mL, while 92% showed serum MCV less than 72 fL. CONCLUSION: In conclusion, collection of information on history should be thorough for feeding and selective examinations for IDA in high-risk groups. Considering the adaptation period, we suggest beginning children on a weaning diet at 45 months. In addition, we need to educate mothers on weaning practice, especially on the necessity of iron-fortified foods for breast-fed infants.
Anemia, Iron-Deficiency ; Child ; Diet ; Ferritins ; Fruit ; Hospitals, University ; Humans ; Infant ; Iron ; Malnutrition ; Mothers ; Surveys and Questionnaires ; Weaning

PURPOSE: We analyzed the histopathologic findings of the patients with ultrasongraphic Breast Imaging Reporting and Data System (BI-RADS) Category 4a breast lesions to determine which patient can be excluded from any invasive, diagnostic procedure in the future. METHODS: Of the 180 cases of BI-RADS Category 4a breast lesions that were diagnosed with ultrasonography during a 6 month-period, 132 cases were pathologically confirmed and these were analyzed retrospectively. Four benign cases that did not undergo any further procedure after fine needle biopsy and 6 malignant cases (4.5%) were excluded from this study. RESULTS: Of the 122 cases, 77 cases (63.1%) showed homogeneous benign finding, and 45 cases (36.9%) showed heterogeneous finding that was made up of two or more different pathologic lesions. Fibroadenoma (55.8%) was the most frequent pathologic finding in the cases with homogeneous finding, followed by fibrocystic change (14.3%), and fibrosis (7.8%). The cases with heterogeneous finding presented fibrocystic change (55.5%), microcalcification (48.8%), ductal hyperplasia (42.2%), and fibroadenoma (31.1%) in the order of frequency. CONCLUSION: Lesion with heterogeneous histopathologic nature was the most frequent finding defined as category 4a in breast ultrasonography, followed by fibrodenoma, fibrocystic change, microcalcification, and ductal hyperplasia. Refining more specific ultrasonographic findings of these lesions would guarantee that radiologists exclude more benign lesions from category 4a.
Biopsy, Fine-Needle ; Breast ; Fibroadenoma ; Fibrosis ; Humans ; Hyperplasia ; Information Systems ; Retrospective Studies ; Ultrasonography, Mammary