• BMB Reports
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• 제30권6호
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• pp.415-420
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• 1997

Although $CD4^+$ T cell responses to protein-derived antigen have well been understood, the epitopes recognized by hapten-specific $CD4^+$ T cells have not been fully defined. In this study, we characterized the response of a T cell hybridoma (5Di0.1B8) which is specific for a hapten. N-hydroxysuccinimidyl-4-azidobenzoate (HSAB) restricted by MHC class II $I-A^d$. Using three different antigen presenting cells (APCs) expressing $I-A^d$, the role of class II MHC proteins in haptenic antigen presentation and subsequent activation of 5D10.1B8 has been examined. Activation of 5D10.1B8 T cells by HSAB analogs was also performed. Our results show that each APC activated T cells differentially and that interleukin-2 (IL-2) augmented antigen-presenting ability of all the APCs, suggesting that increased expression of class II MHC protein by IL-2 played an important role in HSAB presentation and T cell activation. Finally, early T cell receptor-dependent signals induced by HSAB or its analogs were examined by phosphotyrosine immunoblot analysis, and showed that tyrosine phosphorylation level of a 18-20 kD protein increased upon stimulation.

• 대한치과교정학회지
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• 제16권1호
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• pp.167-177
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• 1986

This study was undertaken to compare the main differences and its effects of the 4 first bicuspid extraction on the face and dental arch of the class II div 1 malocclusion. The subjects consisted of twenty two class II div 1 malocclusion, four males, eighteen females, were 14 Years 2 Months old at the stan of the treatment 16 Year 3 Months old at the end of the treatment. (mean age) Twenty one variables were observed by comparing the statistical data of the pretreatment records with postteratment records, which were consited of eight varibles on the study model digitation, thirteen variables on the tracing of the lateral cephalogram. The following results were obtained. 1. No significant change was observed in the intercanine width. 2. Intercuspal widths of the 1st. premolar and 2nd. premolar were decreased. 3. Change of the overjet was dependant upon upper anterior rather than lower anterior. 4. No significant changes were observed in facial plane angle and ANB angle. 5. Uprighting of the lower 1st. molar had an effect on the increase of the facial height.

• Restorative Dentistry and Endodontics
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• 제26권6호
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• pp.492-498
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• 2001

The purpose of this study was to evaluate four different composite resins in vitro for microleakage in Class II box type restorations that have gingival margins apical to the cementoenamel junction. Forty caries free extracted human molars were used in this study. The Class II cavities were prepared 1.0mm below cementoenamel junction with a #701 carbide bur. The teeth were randomly divided into four groups, each group comprising 20 treated cavities according to adhesives and filling materials ; Group 1: Scotchbond Multipurpose/Z 100. Group 2: Ariston Liner/Ariston pHc, Group 3: One Step/Pyramid, Group 4: Prime & Bond NT/SureFil. To simulate the clinical situation during restoration placement, a restoration template was fabricated and composite resin was filled using a three sited light-curing incremental technique. The specimens were stored in the 100% humidity for 7 days prior to thermocycling. The specimens were immersed in 2% methylene blue dye solution for 24 hours and then embeded in transparent acrylic resin and sectioned mesiodistally with a diamond wheel saw. The degree of marginal leakage was scored under the stereomicroscope($\times$20) and the data were analyzed by Kruskal Wallis test and Mann Whitney test. (omitted)

• Journal of Chest Surgery
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• 제22권1호
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• pp.116-122
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• 1989

During 22-year period ending in June 1988, operation was performed on 22 patients with primary heart tumor at Yonsei University College of Medicine. Mean age was 38.8*3.03[mean \ulcornerEM] ranging from 14 to 63 years old. Twenty cases were myxomas. Others were fibromyxoma and rhabdomyosarcoma. All patients complained of dyspnea on exertion. Nine cases had palpitation. Other constitutional symptoms were weight loss [7 cases], headache [4 cases], generalized edema [3 cases] and cough [3 cases]. Five cases had neurological symptoms and signs preoperatively. Preoperative NYHA Class was poor [Class II; 8 cases, III; 9 cases and IV; 5 cases]. The most common site of tumor origin was fossa ovalis limbus [16 cases; 72.8%]. Because of severe mitral regurgitation and of recurrent myxoma, 2 cases were reoperated for mitral valve replacement. Postoperative complications were postoperative mitral regurgitation [5 cases; 22.8%] and arrhythmia [4 cases; 18.2%], one of which was supra-His bundle block. All patient survived operation. Follow-up of 15 patients [mean 28.95*8.3 months] was good as functional class 1[8 cases] or II [7 cases]. More effective adjuvant therapy will be necessary to improve long-term prognosis for malignant primary heart tumor.

• Mycobiology
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• 제29권4호
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• pp.179-182
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• 2001

Chitin synthases(UDP-N-acetyl-D-glucosamine: chitin 4-$\beta$-N-acetyl-D-glucosaminyl transferase, EC 2.4.1.16) catalyze the synthesis of chitin from UDP-N-acetyl-D-glucosamine. Two zymogenic type of chitin synthase gene(TmCHS1 and TmCHS2) were amplified and its nucleotide sequences were determined. By the amino acid comparison and UPGMA tree grouping, TmChs1 and TmChs2 were classified as class II and class IV chitin synthases respectively. The class II type TmChs1 was grouped with others of Agaricales ectomycorrhizal mushroom. Additionally the phylogenetic tree was well adapted to Hymenomycete previously classified by morphological and physiological characteristics.

• Archives of Pharmacal Research
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• 제15권2호
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• pp.146-151
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• 1992

The aim of this study was to evaluate capability of pertussis toxin (PT) to active mouse macrophages. The investigations were undertaken to determine whether the role played by this toxin required the A-protomer of the toxin to ADP-ribosylate a guanine nucleotide binding protein (a class I activity) or was dependent on the binding of B-oligomer of the toxin to the surface of target cells (a Class II activity). The results of these experiments have established that the mechanism of macrophage activation with PT seems to be dependent upon a Class II activity of the toxin.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.314.1-314.1
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• 2002

Bacterial ${\beta}$-lactamases provide resistance to ${\beta}$-lactams by hydrolyzing the ${\beta}$-lactam bond, On the basis of their catalytic mechanisms. ${\beta}$-lactamases are divided into two major groups. Class A. C and D which belong to the first group require serine in the active site and class B which is the second group require Zn(II) for their activity. Among class B enzymes, Bacteroides fragilis ${\beta}$-lactamase (CcrA enzyme) require two Zn(II) ions per monomer for maximal enzymatic activities. (omitted)

• Restorative Dentistry and Endodontics
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• 제23권1호
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• pp.288-295
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• 1998

The microleakage of direct-access Class 2 restorations was evaluated. Cavities were prepared at mesial and distal proximal enamel surfaces of 20 extracted human molars through buccal window. Prepared cavities were filled with Ketac-Fil, Ketac-Silver, and Fuji II LC, following manufacturer's instructions. 4 specimens of each restorations were made through sectioning 1/4 of bucco-lingual length mesio-distally after thermocycling between $5^{\circ}C$ and $60^{\circ}C$ and imerging 0.5% basic-fuchsin dye solution. Leakage at both occlusal and gingival margin of each specimen was scored 0 to 3 with stereomicroscope. The results were as follows: 1. At occlusal margin, leakage in Ketac-Fil group was more than Ketac-Silver and Fuji II LC group (ANOVA p<0.05) and there was no significant difference between Ketac-Silver and Fuji II LC group(p>0.05), and at gingival margin, there was no significant difference amang materials (p>0.05). 2. Occlusal margin leaked more than gingival margin in Ketac-Silver and Fuji II LC group (t-test p<0.05). 3. Leakage was different according to bucco-lingual location in Ketac-Fil and Fuji II LC group, and lingaul specimen exhibited more leakage(ANOVA p<0.05).

• Journal of Periodontal and Implant Science
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• 제30권2호
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• pp.229-242
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• 2000

The purpose of this study was to evaluate the effect of fibrin tissue adhesive and porous resorbable calcium carbonate on the periodontal regeneration of the class II furcation defect in dogs. Class II furcation defect was surgically created on the second, third, and fourth premolars bilaterally in the mandibles of six mongrel dogs. The experimental sites were divided into four groups according to the treatment modalities: Control-surgical debridement only; Group I-calcium carbonate grafting; Group II-application of fibrin adhesive only; Group III-application of fibrin adhesive after calcium carbonate grafting. The animals were sacrificed at the 2, 4, and 12 weeks after periodontal surgery and the decalcified specimens were prepared for histological and histometrical examination. The results are as follows : Clinically, there were no inflammatory response in all groups after 2, 4, 12 weeks. In the Control group, junctional epithelium was grown downward to the reference notch. In Group I, graft materials were exfoliated from the defect throughout the experimenta periods andnew bone was seen in the notch area at 4 and 12 week specimens. In Group II, fibrin adhesive was absorbed at 2 week specimens, and connective tissue attachment increased than that of control group. New cementum and new bone were seen above the notch area. In Group III, the graft material was maintained in the defect throughout the experimental period and inducing the amount of periodontal tissue regeneration was higher than other groups. These results suggest that the use of fibrin tissue adhesive in conjunction with porous resorbable calcium carbonate would improves the stability of graft material and inhibit the epithelial down growth and make it be a feasible method for periodontal regeneration.

• 대한치과교정학회지
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• 제23권4호
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• pp.447-454
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• 1993

Patient with skeletal class II relationship was treated with L-ARS. L-ARS is fixed functional appliance that could be effective in children and adolescent patient who don't wear activator. The following results were obtained ; 1) Growth of Mandible was stimulated and overjet was decreased, therefore coupling of anterior teeth was established with L-ARS which is fixed functional appliance. 2) These changes were accomplished with Mandibular skeletal growth with no effect on the Maxilla. 3) L-ARS was especially effective on patient who deny to wear the removable functional appliance.