ABSTRACT
PURPOSE: This study investigated medical students' attitudes toward academic misconduct that occurs in the learning environment during the pre-clinical and clinical periods. METHODS: Third-year medical students from seven medical schools were invited to participate in this study. A total of 337 of the 557 (60.5%) students completed an inventory assessing their attitudes toward academic misconduct. The inventory covered seven factors: scientific misconduct (eight items), irresponsibility in class (six items), disrespectful behavior in patient care (five items), dishonesty in clerkship tasks (four items), free riding on group assignments (four items), irresponsibility during clerkship (two items), and cheating on examinations (one item). RESULTS: Medical students showed a strict attitude toward academic misconduct such as cheating on examinations and disrespectful behavior in patient care, but they showed a less rigorous attitude toward dishonesty in clerkship tasks and irresponsibility in class. There was no difference in students' attitudes toward unprofessional behaviors by gender. The graduate medical school students showed a stricter attitude toward some factors of academic misconduct than the medical college students. This difference was significant for irresponsibility in class, disrespectful behavior in patient care, and free riding on group assignments. CONCLUSION: This study indicates a critical vulnerability in medical students' professionalism toward academic integrity and responsibility. Further study evidence is needed to confirm whether this professionalism lapse is confined only to this population or is pervasive in other medical schools as well.
Subject(s)
Humans , Ethics , Learning , Patient Care , Professional Misconduct , Professionalism , Schools, Medical , Scientific Misconduct , Students, MedicalABSTRACT
PURPOSE@#This study investigated medical students' attitudes toward academic misconduct that occurs in the learning environment during the pre-clinical and clinical periods.@*METHODS@#Third-year medical students from seven medical schools were invited to participate in this study. A total of 337 of the 557 (60.5%) students completed an inventory assessing their attitudes toward academic misconduct. The inventory covered seven factors: scientific misconduct (eight items), irresponsibility in class (six items), disrespectful behavior in patient care (five items), dishonesty in clerkship tasks (four items), free riding on group assignments (four items), irresponsibility during clerkship (two items), and cheating on examinations (one item).@*RESULTS@#Medical students showed a strict attitude toward academic misconduct such as cheating on examinations and disrespectful behavior in patient care, but they showed a less rigorous attitude toward dishonesty in clerkship tasks and irresponsibility in class. There was no difference in students' attitudes toward unprofessional behaviors by gender. The graduate medical school students showed a stricter attitude toward some factors of academic misconduct than the medical college students. This difference was significant for irresponsibility in class, disrespectful behavior in patient care, and free riding on group assignments.@*CONCLUSION@#This study indicates a critical vulnerability in medical students' professionalism toward academic integrity and responsibility. Further study evidence is needed to confirm whether this professionalism lapse is confined only to this population or is pervasive in other medical schools as well.
ABSTRACT
OBJECTIVE: To figure out the more optimal method for freezing and thawing the sperm, we compared with the sperm motility after handling of the sperm based on the different types of freezing and thawing methods. METHODS:Twenty four adult males who visited our infertility clinic from Aug 2004 to Feb 2005 were enrolled. We applied two kinds of freezing method to normal sperm according to WHO standard criteria; automatic slow freezing method (Auto) and manual vapor freezing method (Manu). We also use two different methods of thawing; a 37 degreesC warm water bath (37 degreesC) and 22 degreesC room temperature thawing (22 degreesC). Mean motile percent (MMP) was compared by the freezing methods and thawing methods respectively. We also evaluated the motility in four different ways of freezing and thawing combination. A written informed consent was obtained from each client. This study was approved by IRB. RESULTS: MMP by the freezing method was 56% in Auto group and 52% in Manu group. It was significantly different (P=0.037). In thawing method, it was 59% in 37 degreesC group and 49% in 22 degreesC group (P=0.000). Each of freezing and thawing methods was joined to make four different types of freezing and thawing combinations. In MMP there were 63% in Auto/37 degreesC, 50% in Auto/22 degreesC, 56% in Manu/37 degreesC and 48% in Manu/22 degreesC (P>0.05). CONCLUSION: The automatic method in freezing and room temperature in thawing showed respectively the highest MMP. In four different types of freezing and thawing combinations, Auto/37 degreesC MMP was the highest. There was no statistical difference. This means that all four types of freezing and thawing methods might be used clinically. If further study of larger population or comparison of fertility is done, we would have a better result.
Subject(s)
Adult , Humans , Male , Baths , Ethics Committees, Research , Fertility , Freezing , Handling, Psychological , Infertility , Informed Consent , Sperm Motility , Spermatozoa , WaterABSTRACT
OBJECTIVE: To figure out the more optimal method for freezing and thawing the sperm, we compared with the sperm motility after handling of the sperm based on the different types of freezing and thawing methods. METHODS:Twenty four adult males who visited our infertility clinic from Aug 2004 to Feb 2005 were enrolled. We applied two kinds of freezing method to normal sperm according to WHO standard criteria; automatic slow freezing method (Auto) and manual vapor freezing method (Manu). We also use two different methods of thawing; a 37 degreesC warm water bath (37 degreesC) and 22 degreesC room temperature thawing (22 degreesC). Mean motile percent (MMP) was compared by the freezing methods and thawing methods respectively. We also evaluated the motility in four different ways of freezing and thawing combination. A written informed consent was obtained from each client. This study was approved by IRB. RESULTS: MMP by the freezing method was 56% in Auto group and 52% in Manu group. It was significantly different (P=0.037). In thawing method, it was 59% in 37 degreesC group and 49% in 22 degreesC group (P=0.000). Each of freezing and thawing methods was joined to make four different types of freezing and thawing combinations. In MMP there were 63% in Auto/37 degreesC, 50% in Auto/22 degreesC, 56% in Manu/37 degreesC and 48% in Manu/22 degreesC (P>0.05). CONCLUSION: The automatic method in freezing and room temperature in thawing showed respectively the highest MMP. In four different types of freezing and thawing combinations, Auto/37 degreesC MMP was the highest. There was no statistical difference. This means that all four types of freezing and thawing methods might be used clinically. If further study of larger population or comparison of fertility is done, we would have a better result.
Subject(s)
Adult , Humans , Male , Baths , Ethics Committees, Research , Fertility , Freezing , Handling, Psychological , Infertility , Informed Consent , Sperm Motility , Spermatozoa , WaterABSTRACT
To investigate the genetic characteristics of human influenza type B viruses circulating in Chungbuk province, Korea, we tested 510 clinical samples of nasopharyngeal suction from pediatric patients diagnosed with respiratory illness between June 2007 and June 2008. Twelve out of thirty-six isolates were identified as type B influenza virus by RT-PCR and sequencing analysis. Interestingly, genetic characterization of type B viruses isolated in this study revealed that all type B influenza viruses were the Yamagata lineages, a vaccine strains of southern hemisphere during 2007~2008, rather than the Victoria lineage of northern hemisphere during 2007~2008. Furthermore, there were a total of twelve unique mutations (HA: H40Y, D/G230S, V252M and K272R and NA: P3H, P/T/S42Q, N59S) occurred in our type B isolates. These results suggest that relative high prevalence of type B viruses in Korea during 2007~2008 season might be due to the wrong vaccine strains selection. Taken together, the results of this study demonstrate continuous evolutions of human type B viruses by antigenic drift and also highlight the need to closely monitoring of influenza viruses to aid the early detection of potentially pandemic strains as well as underscore the need for new therapeutics.
Subject(s)
Humans , Herpesvirus 1, Cercopithecine , Influenza B virus , Influenza, Human , Korea , Orthomyxoviridae , Pandemics , Prevalence , Seasons , Suction , VictoriaABSTRACT
PURPOSE: This study was performed to identify academic and nonacademic predictors of the success of entrants to Chungbuk National University Graduate Medical School (CNUMS) during the first 3 years of completion. METHODS: We analyzed the academic achievements in preclinical education in the first 2 years in students who were admitted in 2005 and 2006 and compared them with cognitive admission variables and demographic characteristics. RESULTS: There was no significant difference in academic achievement between students groups that were classified by gender, age, or academic degree type. Among Medical Education Eligibility Test (MEET) subscale scores, Verbal Reasoning was correlated with 'Medical humanities & social sciences' and 'Basic clinical procedures;' Nature Science Reasoning 1 with 'Basic medical sciences;' and Nature Science Reasoning 2 with 'Basic medical sciences' and 'Clinical medicine.' Undergraduate GPA correlated well with all academic achievements. English test scores did not correlate with academic performance. CONCLUSION: Among all of the variables that were examined, undergraduate GPA score was the most reliable variable in predicting academic achievement during the 2-year preclinical medical education, and MEET scores were a secondary indicator of academic achievement at CNUMS.
Subject(s)
Humans , Achievement , College Admission Test , Demography , Education, Medical , Educational Measurement , Educational Status , Humanities , Predictive Value of Tests , Schools, MedicalABSTRACT
Congenital thoracic malformations such as intra- and extra-pulmonary sequestration, cystic adenomatoid malformation, congenital pulmonary airway malformation, malinosculation, bronchogenic cyst, reduplication cyst, and foregut cyst are frequently detected on routine prenatal ultrasound. There are some controversies about treatment for postnatally persistent pulmonary sequestration. Some authors recommend expectant long term follow up but most authors advocate elective surgical excision because of complication such as respiratory distress, infection, intrathoracic bleeding, haemoptysis, cardiac failure, and potential risk of malignancy. We experienced 2 cases of prenatally diagnosed extrapulmonary sequestration which were located in the subdiaphragmatic retroperitoneum. Resections were performed at 2 months and 4 months of age using intraabdominal approach. There were no complications. In conclusion, if the prenatally diagnosed extrapulmonary sequestration remained postnatally, early operation might reduce morbidity related to extrapulmonary sequestration and parental anxiety without any postoperative complication.
Subject(s)
Humans , Anxiety , Bronchogenic Cyst , Bronchopulmonary Sequestration , Follow-Up Studies , Heart Failure , Hemorrhage , ParentsABSTRACT
Japanese encephalitis virus (JEV) is a member of Flaviviruses, transmitted by mosquitoes. The core of JEV is composed of the capsid (C) proteins. In order to produce the recombinant viral C protein and the antiserum specifically recognizing the JEV C protein, we have expressed and purified the JEV C protein as a Glutathion-S-Transferase (GST) fusion protein in E. coli. The JEV C protein-coding region was PCR-amplified using the infectious cDNA of a JEV Korean isolate, and the amplicons were cloned into the pGEX4T-1 E. coli expression vector. GST-C fusion proteins were purified using a glutathione sepharose column. Subsequently, the GST-C fusion proteins were used for immunization of rabbits, and the antisera were obtained from those immunized animals. Western blot analysis using the JEV-infected BHK21 cell lysates showed that these antisera specifically reacted with the JEV C proteins. This study will provide a useful reagent for the diagnosis and understanding of the viral morphogenesis in the JEV-infected cells.
Subject(s)
Animals , Humans , Rabbits , Asian People , Blotting, Western , Capsid Proteins , Capsid , Clone Cells , Culicidae , Diagnosis , DNA, Complementary , Encephalitis Virus, Japanese , Encephalitis, Japanese , Flavivirus , Glutathione , Immune Sera , Immunization , Morphogenesis , Sepharose , Staphylococcal Protein AABSTRACT
Cell motility is essential for a wide range of cellular activities including anigogenesis as well as metastasis of tumor cells. Ras has been implicated in cell migration and invasion, and functions at upstream of mitogen-activated protein kinase (MAPK) families, which include extracellular-signal regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 MAPK. In the present study, we examined the role of JNK in endothelial cell motility using stable transfectant (DAR-ECV) of ECV304 endothelial cells expressing previously established oncogenic H-Ras (leu 61). DAR-ECV cells showed an enhanced angiogenic potential and motility (approximately 2-fold) compared to ECV304 cells. Western blot analysis revealed constitutive activation of JNK in DAR-ECV cells. Pretreatment of JNK specific inhibitors, curcumin and all trans-retinoic acid, decreased the basal motility of DAR-ECV cells in a dose-dependent manner. These inhibitors also suppressed the motility stimulated by known JNK agonists such as TNFalpha and anisomycin. To further confirm the role of JNK, ECV304 cells expressing dominant active SEK1 (DAS-ECV) were generated. Basal non-stimulated levels of the cellular migration were greater in DAS-ECV clones than those in control ECV304 cells. These results suggest that Ras-SEK1-JNK pathway regulates motility of endothelial cells during angiogenesis.
Subject(s)
Humans , Anisomycin/pharmacology , Cell Line , Cell Movement , Curcumin/pharmacology , Endothelium, Vascular/cytology , Enzyme Activation , Enzyme Inhibitors/pharmacology , Extracellular Matrix/metabolism , Genes, ras/genetics , Matrix Metalloproteinases/physiology , Mitogen-Activated Protein Kinases/metabolism , Neovascularization, Physiologic , Tretinoin/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , Umbilical Veins/cytology , Urokinase-Type Plasminogen Activator/physiologyABSTRACT
Cell motility is essential for a wide range of cellular activities including anigogenesis as well as metastasis of tumor cells. Ras has been implicated in cell migration and invasion, and functions at upstream of mitogen-activated protein kinase (MAPK) families, which include extracellular-signal regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 MAPK. In the present study, we examined the role of JNK in endothelial cell motility using stable transfectant (DAR-ECV) of ECV304 endothelial cells expressing previously established oncogenic H-Ras (leu 61). DAR-ECV cells showed an enhanced angiogenic potential and motility (approximately 2-fold) compared to ECV304 cells. Western blot analysis revealed constitutive activation of JNK in DAR-ECV cells. Pretreatment of JNK specific inhibitors, curcumin and all trans-retinoic acid, decreased the basal motility of DAR-ECV cells in a dose-dependent manner. These inhibitors also suppressed the motility stimulated by known JNK agonists such as TNFalpha and anisomycin. To further confirm the role of JNK, ECV304 cells expressing dominant active SEK1 (DAS-ECV) were generated. Basal non-stimulated levels of the cellular migration were greater in DAS-ECV clones than those in control ECV304 cells. These results suggest that Ras-SEK1-JNK pathway regulates motility of endothelial cells during angiogenesis.
Subject(s)
Humans , Anisomycin/pharmacology , Cell Line , Cell Movement , Curcumin/pharmacology , Endothelium, Vascular/cytology , Enzyme Activation , Enzyme Inhibitors/pharmacology , Extracellular Matrix/metabolism , Genes, ras/genetics , Matrix Metalloproteinases/physiology , Mitogen-Activated Protein Kinases/metabolism , Neovascularization, Physiologic , Tretinoin/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , Umbilical Veins/cytology , Urokinase-Type Plasminogen Activator/physiologyABSTRACT
The genetic status of cagA, vacA subtype, iceA1, and babA, and the relationship to gastroduodenal diseases were assessed in Helicobacter pylori isolates in Korea. Seventy-six strains of H. pylori were isolated from the antrum and the corpus of 41 adult patients (22 with peptic ulcer and 19 with gastritis). The cagA, iceA1, and babA genes were assessed by polymerase chain reaction and the vacA subtypes were determined by reverse hybridization-line probe assay. The positive rates of 349-bp cagA, 208-bp cagA, iceA1, and babA genes were 97.4%, 96.1%, 84.2%, and 36.1%, respectively. The vacA s1a, s1b, s1c, and s2 variants were detected in 11.8%, 3.9%, 80.4%, and 1.3%, respectively. m1 (78.9%) is more prevalent than m2 (5.3%). The most common vacA genotype was s1c/m1 (61.9%), and 14 isolates (18.4%) contained mixed vacA genotypes from a single biopsy specimen. Twenty-one (60%) of 35 patients were infected with more than two strains of different cagA, iceA1, babA, and vacA genotypes. None of cagA, iceA1, babA, and vacA s1/m1 were associated with peptic ulcer. In conclusion, most H. pylori isolates in Korea carry cagA, iceA1, and vacA s1c/m1 genes, and reside with multiple strains. These genes do not correlate with the peptic ulcer in the Korean patients.
Subject(s)
Adult , Aged , Female , Humans , Male , Bacterial Proteins/genetics , Genotype , Helicobacter pylori/classification , Middle Aged , Peptic Ulcer/etiologyABSTRACT
Although most persons infected with Helicobacter pylori harbor a single strain of the organism, multiple strain colonization in the same patient is also occasionally reported in developed countries. The aims of this study were to determine the prevalence of multiple strain colonization in Korean patients and to detect the cagA, iceA1, and babA status of H. pylori isolated from the antrum and body of the stomach. H. pylori was obtained from 35 patients from the antrum and body of the stomach. The genomic diversity of H. pylori was determined by random amplified polymorphic DNA analysis. The status of cagA, iceA1, and babA genes of H. pylori was assessed by polymerase chain reaction with appropriate primers. Clearly different diversity patterns were identified among the isolates from 35 individual patients. Eighteen (51.4%) patients had a single strain of H. pylori. Eight (22.9%) and nine (25.7%) patients had subtypically (one or two bands difference) and typically (clearly different pattern) different strains of H. pylori in the antrum and body, respectively. Among the 70 isolates of H. pylori from 35 patients, the positive rates of 349-bp and 208-bp cagA gene fragments and the iceA1 gene were 68/70 (97.1%), 68/70 (97.1%), and 58/70 (82.9%), respectively. However, the babA gene was found in 22/66 cases (31.4%). In five out of 18 patients with a single strain, the genetic status of cagA, iceA1, and babA varied between the isolates from the antrum and the body. In 8/17 patients with subtypically or typically different strains, the gene status differed between antrum and body isolates. The prevalence of co-colonization with typically or subtypically different strains is high in Korea, and sub-clones with different pathogenic gene status exist within strains of identical RAPD patterns.
Subject(s)
Humans , Colon , Developed Countries , DNA , Helicobacter pylori , Helicobacter , Korea , Polymerase Chain Reaction , Prevalence , Pyloric Antrum , StomachABSTRACT
Angiogenesis is a fundamental biological process including endothelial cell adhesion, migration, invasion and tube formation. Integrin receptors of endothelial cells play important roles in angiogenesis. They mediate cell-cell contact and cell adhesion to extracellular matrix. Roles of integrins have been described for a number of cell types. ECV304 endothelial cells were known to overexpress alpha3beta1 integrin and to form tube like structure in 3-D Matrigel culture. However the function of alpha3beta1 integrin in endothelial cells remains to be determined. Therefore, we have investigated morphological characteristics of ECV304 cells and roles of alpha3beta1 integrin in angiogenesis. To elucidate several characteristics, ECV304 endothelial cells were compared with HUVEC in the aspect of morphology, localization of integrins, angiogenesis pattern. In addition, role of alpha3beta1 integrin were analyzed in the aspect of endothelial cell binding, migration, invasion and tube formation on Matrigel. The result showed that alpha3beta1 integrin overexpressed ECV304 endothelial cells showed strong adhesiveness to extracellular matrix proteins, and high migration and invasion activities. Furthermore, expression of alpha3beta1 integrin was increased according to time course during in vitro culture and was continuously strong in ECV304 cells on 3-D Matrigel culture. These results indicate that alpha3beta1 integrin is able to be a critical component in control of angiogenesis by regulation of cell adhesion, migration, invasion and tube formation of ECV304 endothelial cells.
Subject(s)
Adhesiveness , Biological Phenomena , Cell Adhesion , Endothelial Cells , Extracellular Matrix , Extracellular Matrix Proteins , Integrin alpha3beta1 , IntegrinsABSTRACT
Clostridium perfringens is an anaerobe responsible for a wide range of diseases in animals and humans. Symptoms associated with C. perfringens food poisoning are caused by enterotoxin expressed only during sporulation of C. perfringens. It has been known that only 6% of global C. perfringens isolates carry the enterotoxin gene. We found 2 strains of enterotoxigenic C. perfringens out of 33 strains isolated from various sources in Korea using PCR. It was also found that these two strains were both type A that were strongly associated with food poisoning by checking the presence of four major lethal toxins (a-, B-, e-, l-toxin) using PCR. These results suggest that foodborne illness caused by C. perfringens may be common in Korea and that public education is necessary to prevent contamination of foods by this organism.
Subject(s)
Animals , Humans , Clostridium perfringens , Clostridium , Education , Enterotoxins , Foodborne Diseases , Korea , Polymerase Chain ReactionABSTRACT
Hyperacute rejection (HAR) is the major obstacle to xenotransplantation. In HAR complement (C') cascade is activated following the binding of xenoreactive antibodies to the donor tissue. Complement receptor type 1 (CR1), the most efficient protein in inhibiting activated C's, was modified with membrane cofactor protein (MCP) to make a more efficient C'-inhibiting hybrid molecule. Modification was done by swapping the four active site short consensus repeats (SCRs) of MCP for the SCRs 8-11 of CR1. The hybrid molecule (CR1/MCP) was expressed on the surface of mouse L cells. When the complement inhibitory activity of the CR1/MCP protein was compared with that of the wild CR1 (wCR 1) protein, CR1/MCP's inhibitory activity was weaker than wCR1's. CR1/MCP protein's L cell protecting activity from complement's attack was more prominent in adherent state than in suspension state. From these results it was suggested that the conformational direction of MCP's inhibitory action on C' is different from that of CR1 and most of the MCP expression seems to be confined to the apical side but not to the basal side of the L cell in adherent state. The wCR1's expression seems to be present on all sides of the L cell. Finally, the inverted direction of SCRS-11 of CR1 or variable length of the serine-threoninrich structure of MCP could be tried to make other CR1/MCP variants with more powerful C' inhibitory activities.
Subject(s)
Animals , Humans , Mice , Antibodies , Membrane Cofactor Protein , Catalytic Domain , Complement System Proteins , Consensus , Receptors, Complement , Tissue Donors , Transplantation, HeterologousABSTRACT
29 isoniazid (INH) resistant isolated strains and INH sensitive reference strain (H37Rv) of Mycobacterium tuberculosis were analysed by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and NciI restriction mapping for the detection of mutations in katG gene and inhA gene. The katG gene was divided into 3 parts (Akat, Bkat, Ckat; each part is about 800 bp) and amplified, inhA gene was amplified as a whole. Each of the amplified 800 bp DNA was digested into small fragments of less than 400 bp with restriction enzymes for the direct PCR-SSCP analysis. Firstly, 10 strains were analysed. All the 10 isolates showed clearly distinct SSCP patterns in Bkat from that of the reference strain, but only two isolates showed distinct SSCP patterns in Akat, and no isolated strain showed any distinct SSCP patterns in Ckat. 10 isolates also showed distinct SSCP patterns in inhA. NciI restriction mapping of Bkat showed mutation in codon 463 in 7 strains among 10 isolated strains. With these results an early detection strategy for the INH resistant M. tuberculosis was applied to the rest of 19 isolated INH resistant strains. Firstly, isolates were screened by Ncsl mapping in Bkat, and 13 strains showed mutations in codon 463. Secondly, the rest of 6 INH resistant isolates were analysed by PCR-SSCP with restriction enzyme digestion (PCR-SSCP-RE) in Bkat, and all the strains showed distinct SSCP patterns from that of the INH sensitive reference strain. This proved our strategy as effective and economic and time saving method in early detection of INH resistant M. tuberculosis.
Subject(s)
Codon , Diagnosis , Digestion , DNA , Isoniazid , Korea , Mycobacterium tuberculosis , Mycobacterium , Polymorphism, Single-Stranded Conformational , Restriction Mapping , TuberculosisABSTRACT
This study was conducted to see the effect of TiN ion-plating on the bond strength of orthodontic bracket. Three stainlesssteel brackets with different base types were chosen; when TiNTion-plated brackets and non ion-plated brackets were bonded to the teeth, initial and long-term bond strength were measured The observations of bonding surface and failure sites through the scanning electron microscope were analysed and compared. The summary of this study was as follows: When TiN ion-plating was not applied, the Micro-Loc type was the highest in bond strength atter 24 hours as 5.89+/-1.77 MPa, followed by 4.27+/-1.12 MPa for Foil Mesh type and 2.64+/-0.58 MPa for Undercut type(P<0.05). Under TiN ion-plating, the bond strength after 24 hours showed: Micro-Loc type - 6.26+/-1.51 MPa, Foil Mesh type - 7.45+/- 2.01 MPa, Undercut type - 2.93+/-0.84 MPa Unlike in the case of non ion-plating, Foil Mesh type showed a higher strength than Micro-Loc type, with Undercut type still showing the lowest bond strength(P<0.05). The bond strength, after 24 hours, increased in case of ion-plated in all 3 types, but a significant increase was shown only in Foil Mesh type(P<0.001). Under a long-term immersion, regardless of ion or non ion-plating, bond strength in general increased over the initial bond strength(one day), with more stability. Through scanning electron microscopic observation of bonding surface, it was found that, regardless of the bracket base type or the application of ion-plating, the resin was thoroughly spreaded into bracket base to form a solid bonding surface between the bracket and the tooth.. This was also true in case of a long-term immersion. The scanning electron microscopic observation of failure sites revealed diverse failure patterns.