STATEMENT OF PROBLEM: Resonance frequency analysis has been increasingly served as a noninvasive and objective method for clinical monitoring of implant stability. Many clinical studies must be required for standardized data using RFA. PURPOSE: This study was performed to evaluate RFA value changes in two anodized implant groups. MATERIAL AND METHOD: Among a total of 24 implants, twelve screw shaped implants as a test group (H2-R8.5) were manufactured, which had a pitch-height of 0.4 mm, an outer diameter of 4.3 mm, a length of 8.5 mm, and external hexa-headed, were turned from 5 mm rods of commercially pure titanium (ASTM Grade IV, Warantec Co., Seoul, Korea), and another twelve implants as a control group were Branemark Ti-Unite MK4 (diameter 4.0 mm, length 8.5 mm). Each group was installed in tibia of rabbit. Two implants were placed in each tibia (four implants per rabbit). Test two implants were inserted in right side and control two in left side. ISQ values were measured using Osstell(TM) (Integration Diagnostics Ltd. Sweden) during fixture installation, and 12 weeks later and evaluated the RFA changes. RESULTS: Mean and SD of baseline ISQ values of test group were 75.0 +/- 3.4 and 68.7 +/- 8.1 for control group. Mean and SD of ISQ values 12 weeks after implant insertion were 73.2 +/- 4.7 for test group and 72.6 +/- 3.9 for control group. There were no statistically significant differences between groups in ISQ values after 3months (P>0.05). From the data, RFA gains after 3 months were calculated, and there was statistically significant difference between groups (P<0.05). CONCLUSION: Although there were RFA changes between groups, implant stability after experimental period shows alike tendency and good bone responses.
Seoul ; Tibia ; Titanium

BACKGROUND: It is not yet clear whether the abnormal cytokine production in relation to serum IgE levels in atopic dermatitis (AD) is associated with the amount of mRNA of cytokine gene. OBJECTIVE: Our purpose was to delineate the effect of reciprocal correlation in the level of mRNA between interleukin-4 (I") and interferon-gamma (IFN-γ) in severe AD. METHODS: We examined 15 cases including 5 AD patients with high serum IgE (>2,000 kU/liter), 5 AD patients with low serum IgE (<100 kU/liter), and 5 healthy controls. Using semi quantitative reverse transcription-polymerase chain reaction, IL-4 and IFN-γ gene expressions in peripheral mononuclear cells (PBMC) were examined. RESULTS: 1) IL-4 gene expression in spontaneous PBMC was higher in AD patient groups than in control group, significantly higher only in AD patient group with high serum IgE level (p < 0.05). 2) IFN-γ gene expression in spontaneous PBMC showed increased tendency in AD patient groups than in control group without statistical significance. 3) IL-4 and IFN-γ gene expressions in stimulated PBMC were not different among all three groups. CONCLUSION: In light of our results, high and low IgE subgroups in AD can exist and AD may not be R characterized by the shift in the reciprocal relationship between IL-4 and IFN-γ when T cells are stimulated under antigen presenting cell-independent conditions.
Dermatitis, Atopic ; Gene Expression ; Humans ; Immunoglobulin E* ; Interferon-gamma* ; Interleukin-4* ; RNA, Messenger ; T-Lymphocytes

The posterior cruciate ligament is an anatomically and biomechanically complex structure. PCL injuries are reported to occur in 1-40% of acute knee injuries, with isolated PCL tear, less common than PCL tears combined with other Iigament injuries. Controversy exists concerning the geatment of the PCL injures. Recently, arthroscopic techniques of PCL reconstruction are becoming nore refined and reproducible. Between July 1993 and May 1995, 25 operations for PCL rupture were performed in our hospital. At the follow-up examinations we noted mild to moderate posterior instablilty which was not noted at the time of operation and during the immediate postoperative period. We reviewed type (if injuries, amplitude of initial posterior tibia1 translation, surgical techniques, which seemcd to be in relation ivith the postoperative instabilities. At final follow-up, the mean Lysholm knee score was 86 points, and the posterior tibial translation 6.5mm on posterior stress radiographs. The ligament augmentation device provided no benefit. The ideal positioning and fixation of the graft and protection of the graft from abrasion seemed to be important to get a good results.
Follow-Up Studies ; Knee ; Knee Injuries ; Ligaments ; Patellar Ligament* ; Posterior Cruciate Ligament ; Postoperative Period ; Rupture ; Transplants*

Different kinds of forces can be applied to the biological tissue. The analysis of the applied force is highly important to explain the mechanism of cellular response. In this study, the applied force to the collagen gel was analyzed by the finite elements analysis. The model received two different kinds of static force (compression and tension). The force range was 50g to 400g. In results, von Mises stress was concentrated in the peripheral region in the compression model. It was concentrated in the central area in the tension model. However, the compressive force was high in the peripheral area of the compression model and the tensional force was also high in the same area of the tension model. In conclusion, the applied force could be different to the region and it should be considered in the experiment to analyze the effects of the mechanical force on the cells.
Cell Culture Techniques ; Collagen ; Finite Element Analysis

Different kinds of forces can be applied to the biological tissue. The analysis of the applied force is highly important to explain the mechanism of cellular response. In this study, the applied force to the collagen gel was analyzed by the finite elements analysis. The model received two different kinds of static force (compression and tension). The force range was 50g to 400g. In results, von Mises stress was concentrated in the peripheral region in the compression model. It was concentrated in the central area in the tension model. However, the compressive force was high in the peripheral area of the compression model and the tensional force was also high in the same area of the tension model. In conclusion, the applied force could be different to the region and it should be considered in the experiment to analyze the effects of the mechanical force on the cells.
Cell Culture Techniques ; Collagen ; Finite Element Analysis

No abstract available.

PURPOSE: Fibronectin (FN) has been shown to stimulate bone regeneration in animal models. The aim of this study was to evaluate the capacity of bovine bone mineral coated with synthetic oligopeptides to enhance bone regeneration in rabbit calvarial defects. METHODS: Oligopeptides including fibrin-binding sequences of FN repeats were synthesized on the basis of primary and tertiary human plasma FN structures. Peptide coated and uncoated bone minerals were implanted into 10 mm calvarial defects in New Zealand white rabbits, and the animals were sacrificed at 4 or 8 weeks after surgery. After specimens were prepared, histologic examination and histomorphometric analysis were performed. RESULTS: At 4 weeks after surgery, the uncoated groups showed a limited amount of osteoid formation at the periphery of the defect and the oligopeptide coated groups showed more osteoid formation and new bone formation in the center of the defect as well as at the periphery. At 8 weeks, both sites showed increased new bone formation. However, the difference between the two sites had reduced. CONCLUSIONS: Fibrin-binding synthetic oligopeptide derived from FN on deproteinized bovine bone enhanced new bone formation in rabbit calvarial defects at the early healing stage. This result suggests that these oligopeptides can be beneficial in reconstructing oral and maxillofacial deformities or in regenerating osseous bone defects.
Animals ; Bone Regeneration ; Congenital Abnormalities ; Fibrin ; Fibronectins ; Humans ; Minerals ; Models, Animal ; Oligopeptides ; Osteogenesis ; Plasma ; Rabbits

Accidental intrathecal vincristine instillation is extremely toxic to the central nervous system. If given intrathecally, it produces a rapidly ascending, usually fatal, neuromyeloencephalopathy. This is a case where a 10-year-old girl received an inadvertent intrathecal administration of vincristine. The clinical course was rapidly progressive and resulted in comatose and vegetative state. Magnetic resornance image at post-injection 11 day showed high signal intensity lesion in cerebellar hemisphere and vermis adjacent to CSF passage third and fourth ventricle on T2 weighted images.
Central Nervous System ; Child ; Coma ; Female ; Fourth Ventricle ; Humans ; Persistent Vegetative State ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Vincristine*

The importance of soft tissue response to implant abutments has become one of the major issues in current implant dentistry. To date, numerous studies have emphasized on maintaining connective tissue barriers in quantity, as well as in quality for the long term success of dental implants. The cells mainly consisting the soft tissue around dental implants are fibroblasts and epithelial cells. The mechanism of the fibroblasts'adhesions to certain substrata can be explained by the 'focal adhesion'theory. On the other hand, epithelial cells adhere to the substratum via hemidesmosomes. The typical integrin-mediated adhesions of cells to certain matrix are called 'cell-matrix adhsions'. The focal adhesion complex of fibroblasts, in relation to the cell-matrix adhsions, consists of the extracellular matrix(ECM) such as fibronectin, the transmembrane proteins such as integrins, the intracellular cytoplasmic proteins such as vinculin, talin, and more, and the cytoskeletal structures such as filamentous actin and microtubules. The mechanosensory function of integrins and focal adhesion complexes are considered to play a major role in the cells'adhesion, migration, proliferation, differentiation, division, and even apoptosis. The '3-D matrix adhesions'defined by Cukierman et al. makes a promising future for the verification of the actual process of the cell-matrix adhesions in vivo and can be applied to the field of implant dentistry in relation to obtaining strong soft tissue attachment to the implant abutments.
Actins ; Apoptosis ; Cell-Matrix Junctions* ; Connective Tissue ; Cytoplasm ; Dental Implants* ; Dentistry ; Epithelial Cells ; Fibroblasts ; Fibronectins ; Focal Adhesions ; Hand ; Hemidesmosomes ; Integrins ; Microtubules ; Talin ; Vinculin

The importance of soft tissue response to implant abutments has become one of the major issues in current implant dentistry. To date, numerous studies have emphasized on maintaining connective tissue barriers in quantity, as well as in quality for the long term success of dental implants. The cells mainly consisting the soft tissue around dental implants are fibroblasts and epithelial cells. The mechanism of the fibroblasts'adhesions to certain substrata can be explained by the 'focal adhesion'theory. On the other hand, epithelial cells adhere to the substratum via hemidesmosomes. The typical integrin-mediated adhesions of cells to certain matrix are called 'cell-matrix adhsions'. The focal adhesion complex of fibroblasts, in relation to the cell-matrix adhsions, consists of the extracellular matrix(ECM) such as fibronectin, the transmembrane proteins such as integrins, the intracellular cytoplasmic proteins such as vinculin, talin, and more, and the cytoskeletal structures such as filamentous actin and microtubules. The mechanosensory function of integrins and focal adhesion complexes are considered to play a major role in the cells'adhesion, migration, proliferation, differentiation, division, and even apoptosis. The '3-D matrix adhesions'defined by Cukierman et al. makes a promising future for the verification of the actual process of the cell-matrix adhesions in vivo and can be applied to the field of implant dentistry in relation to obtaining strong soft tissue attachment to the implant abutments.
Actins ; Apoptosis ; Cell-Matrix Junctions* ; Connective Tissue ; Cytoplasm ; Dental Implants* ; Dentistry ; Epithelial Cells ; Fibroblasts ; Fibronectins ; Focal Adhesions ; Hand ; Hemidesmosomes ; Integrins ; Microtubules ; Talin ; Vinculin