2.STRAIN AND TEMPERATURE CHANGES DURING THE POLYMERIZATION OF AUTOPOLYMERIZING ACRYLIC RESINS.
Hyung Jun AHN ; Chang Whe KIM ; Yung Soo KIM
The Journal of Korean Academy of Prosthodontics 2001;39(6):709-734
The aims of this experiment were to investigate the strain and temperature changes simultaneously within autopolymerizing acrylic resin specimens. A computerized data acquisition system with an electrical resistance strain gauge and a thermocouple was used over time periods up to 180 minutes. The overall strain kinetics, the effects of stress relaxation and additional heat supply during the polymerization were evaluated. Stone mold replicas with an inner butt-joint rectangular cavity (40.0x25.0mm, 5.0mm in depth) were duplicated from a brass master mold. A strain gauge (AE-11-S50N-120-EC, CAS Inc., Korea) and a thermocouple were installed within the cavity, which had been connected to a personal computer and a precision signal conditioning amplifier (DA 1600 Dynamic Strain Amplifier, CAS Inc., Korea) so that real-time recordings of both polymerization-induced strain and temperature changes were performed. After each of fresh resin mixture was poured into the mold replica, data recording was done up to 180 minutes with three-second interval. Each of two poly (methyl methacrylate) products (Duralay, Vertex) and a vinyl ethyl methacrylate product (Snap) was examined repeatedly ten times. Additionally, removal procedures were done after 15, 30 and 60 minutes from the start of mixing to evaluate the effect of stress relaxation after deflasking. Six specimens for each of nine conditions were examined. After removal from the mold, the specimen continued benchcuring up to 180 minutes. Using a waterbath (Hanau Junior Curing Unit, Model No.76-0, Teledyne Hanau, New York, U.S.A.) with its temperature control maintained at 50degrees C, heat-soaking procedures with two different durations (15 and 45 minutes) were done to evaluate the effect of additional heat supply on the strain and temperature changes within the specimen during the polymerization. Five specimens for each of six conditions were examined. Within the parameters of this study the following results were drawn : 1. The mean shrinkage strains reached -3095mu epsilon, -1796mu epsilon and -2959mu epsilon for Duralay, Snap and Vertex, respectively. The mean maximum temperature rise reached 56.7degrees C, 41.3degrees C and 56.1degrees C for Duralay, Snap, and Vertex, respectively. A vinyl ethyl methacrylate product (Snap) showed significantly less polymerization shrinkage strain (p<0.01) and significantly lower maximum temperature rise (p<0.01) than the other two poly (methyl methacrylate) products (Duralay, Vertex). 2. Mean maximum shrinkage rate for each resin was calculated to ?31.8mu epsilon/sec, -15.9mu epsilon/sec and ?31.8mu epsilon/sec for Duralay, Snap and Vertex, respectively. Snap showed significantly lower maximum shrinkage rate than Duralay and Vertex (p<0.01). 3. from the second experiment, some expansion was observed immediately after removal of specimen from the mold, and the amount of expansion increased as the removal time was delayed. For each removal time, Snap showed significantly less strain changes than the other two poly (methyl methacrylate) products (p<0.05). 4. During the external heat supply for the resins, higher maximum temperature rises were found. Meanwhile, the maximum shrinkage rates were not different from those of room temperature polymerizations. 5. From the third experiment, the external heat supply for the resins during polymerization could temporarily decrease or even reverse shrinkage strains of each material. But, shrinkage re-occurred in the linear nature after completion of heat supply. 6. Linear thermal expansion coefficients obtained from the end of heat supply continuing for an additional 5 minutes, showed that Snap exhibited significantly lower values than the other two poly (methyl methacrylate) products (p<0.01). Moreover, little difference was found between the mean linear thermal expansion coefficients obtained from two different heating durations (p>0.05).
Acrylic Resins*
;
Electric Impedance
;
Fungi
;
Heating
;
Hot Temperature
;
Kinetics
;
Microcomputers
;
Polymerization*
;
Polymers*
;
Relaxation
3.Diagnostic accuracy of stable microbubble rating test for the early detection of neonatal respiratory distress syndrome.
Jung Sam JUN ; Chy Hyung PARK ; Jong Woo BAE ; Chang Il AHN
Journal of the Korean Pediatric Society 1992;35(10):1361-1368
No abstract available.
Microbubbles*
;
Respiratory Distress Syndrome, Newborn*
4.Detection of BLV Proviral DNA in Korean Native Goats Experimentally Infected with Bovine Leukemia Virus by Polymerase Chain Reaction.
Moo Hyung JUN ; Kyung Soo CHANG ; Young Sung CHO ; Jong Hyeon PARK ; Soo Hwan AN
Journal of the Korean Society of Virology 1997;27(2):217-226
PCR implication using the primers for gag, pol and rev genes in BLV (bovine leukemia virus) proviral DNA and syncytium assay were carried out for the Korean native goats experimentally infected with bovine leukemia virus to investigate pathogenesis of BLV in the goats, and to establish a model animal for BLV infection. The oligonucleotide primers used in PCR revealed very high specificity, The minimal amount of FLK-BLV cellular chromosomal DNA to detect the integrated BLV proviral DNA was 10 ng. The peripheral blood lymphocytes from the goat infected with BLV were examined at regular intervals by PCR amplification and syncytium assay. Pol or gag genes were detected in none of three infected goats at the 1st week post-infection (p.i.). At the 4th week p.i., one of three goats showed the amplified gag gene. Thereafter detection rates for the genes were increased, indicating that the BLV proviral genes were integrated in all of the lymphocytes from three goats, at the 16th weeks p.i., when it was evident in syncytium assay that the lymphocytes from all of three goats were infested with infective BLV. Investigating the tissues from the necropsied goats at the 8th month p.i., the amplified BLV proviral genes and infective BLV were detected in all of the peripheral lymphocytes from three infected-goats. Among various tissues examined, the amplified BLV proviral genes were observed in spleen and superficial cervical, mandibular and retropharyngeal lymph nodes, and the infective BLV, in superficial cervical and mandibular lymph nodes. It was assumed that the Korean native goat was quite susceptible to BLV infection, indicating that the goat could be a good model animal for BLV.
Animals
;
Cattle
;
Deltaretrovirus Infections
;
DNA Primers
;
DNA*
;
Enzootic Bovine Leukosis*
;
Genes, gag
;
Genes, rev
;
Giant Cells
;
Goats*
;
Leukemia
;
Leukemia Virus, Bovine*
;
Lymph Nodes
;
Lymphocytes
;
Polymerase Chain Reaction*
;
Sensitivity and Specificity
;
Spleen
5.Molecular Cloning and Nucleotide Sequence of the Gene Encoding Fusion(F) Protein of the Thermostable Newcastle Disease Virus Isolated from a Diseased Pheasant.
Kyung Soo CHANG ; Kui Hyun KIM ; Moo Hyung JUN ; Hee Jong SONG ; Jong Hyeon PARK
Journal of the Korean Society of Virology 1998;28(3):233-244
The gene encoding F protein of CBP-1 strain, a heat-stable Newcastle disease virus (NDV) isolated from the diseased pheasants in Korea, was characterized by reverse transcription-polymerase chain reaction (RT-PCR), nucleotide and amino acid sequences. Virus RNA was prepared from the chorioallatoic fluid infected with NDV CBP-1 virus and cDNA was amplified by RT-PCR, cloned and sequenced to analyze. The PCR was sensitive as to detect the virus titer above 25 hemagglutination unit. 1.7kb (1,707bp) size of the cDNA was amplified and cloned into BamHI site of pVL1393 Baculo transfer vector. The nucleotide sequences for F protein were determined by dye terminator cyclic sequencing using four pairs of primers, and 553 amino acid sequences were predicted. In comparison of the nucleotide sequence of F gene of CBP-1 with those of other NDV strains, the homology revealed 88.8%, 98.5% and 98.7% with Kyojungwon (KJW), Texas GB and Beaudette C strains, respectively. As the deduced 553 amino acid sequences of F protein of CBP-1 were compared with those of other NDV strains, the homology appeared 89.9%, 98.7% and 98.9% with KJW, Texas GB and Beaudette C strains, respectively. The putative protease cleavage site (112-116) was R-R-Q-K-R, indicating that CBP-1 strain is velogenic type. The amino acid sequences include 6 sites of N-asparagine-linked glycosylation and 13 cysteine residues. These data indicate that the genotype of CBP-1 strain is more closely associated with the strains of Texas GB and Beaudette C than KJW strain.
Amino Acid Sequence
;
Animals
;
Base Sequence*
;
Clone Cells
;
Cloning, Molecular*
;
Cysteine
;
DNA, Complementary
;
Genotype
;
Glycosylation
;
Hemagglutination
;
Korea
;
Newcastle disease virus*
;
Newcastle Disease*
;
Polymerase Chain Reaction
;
RNA
;
Texas
;
Viral Load
6.A FLUOROSCOPIC STUDY ON THE STABILITY OF SKIN REFERENCE POINTS DURING JAW OPENING AND CLOSING MOVEMENT.
Hyung Jun AHN ; Chang Whe KIM ; Yung Soo KIM ; Yong Ho KIM
The Journal of Korean Academy of Prosthodontics 1999;37(4):516-530
The current clinical technique for occlusal vertical dimension recording is based on marking the skin reference points on the patient's face and measuring between these pints using caliper-like device. And it is difficult to achieve reliable measurements by this technique because of movable soft tissue. The purpose of this study is to reveal the stability of skin reference points by comparing the relative movement between extra-oral skin reference points and intra-oral reference points using X-ray fluoroscope. 10 test subjects were divided into 2 groups : Group I (natural dentition) and Group II (denture-wearer whose vertical dimension was lost) and Group III consists of identical test subjects to Group II with their upper denture removed and record base inserted. Attaching the 3mm diameter steel ball to nose tip, chin and to existing denture (or record base), fluoroscopic examination and recording were taken during 2 jaw opening and closing movements. After subsequent digitization using personal compute, 1219 still pictures with 0.1 second interval were made. Using the 2 dimensional graphic software, measurements between reference points were executed. Dividing the entire jaw movement into 3 ranges (total, 1st half opening, 2nd half opening), rate of movement and relative movement between extra-oral and intra-oral reference points were calculated and statistically analyzed. The results of this study are as follows. 1. Within the same experimental group, no statistical difference was found in the stability of skin reference between lower lip point and chin point during total range of jaw opening and closing movement (p>.05). 2. In the first half range of jaw opening, statistical difference was found between Group I (natural dentition) and Group II (denture wearer) (p<.05). Group I has greater skin reference stability than Group II. 3. In the first half range of jaw opening, statistical difference was found between Group I and Group III (record base wearer) (p<.05). Group I has greater skin reference stability than Group III. 4. In the first half range of jaw opening, no statistical difference was found in the stability of skin reference between Group II and Group III (p>.05). 5. In the second half range of jaw opening, no statistical difference was found in the stability of skin reference between any experimental groups (p>.05). 6. In patients with their occlusal vertical dimension lost, employing other measuring references rather than skin is recommended because of low stability.
Chin
;
Dentures
;
Humans
;
Jaw*
;
Lip
;
Nose
;
Skin*
;
Steel
;
Vertical Dimension
7.Sagittal mandibulectomy in tonsillar cancer.
Hyung Jun KIM ; In Ho CHA ; Eun Chang CHOI
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2000;26(4):396-398
Sagittal mandibulectomy provided safe oncologic margins and functional and esthetic advantages in the surgical treatment of tonsillar cancers that abut but do not infiltrate the mandible.
Mandible
;
Tonsillar Neoplasms*
8.Cloning and Expression of Hemagglutinin-Neuraminidase Gene of a Thermostable Isolate of Newcastle Disease Virus by Baculovirus Recombinants.
Kyung Soo CHANG ; Moo Hyung JUN
Journal of Bacteriology and Virology 2005;35(1):57-66
The hemagglutinin-neuraminidase (HN) gene of a thermostable Newcastle disease virus isolated from the diseased pheasants in Korea was cloned using Baculovirus transfer vector system, constructing pVL-NDHN inserted with HN gene (1.75 kbp). The HN recombinant baculovirus was generated in Sf-9 cells by co-transfection with pVL-NDHN and linearized baculovirus DNA. The Sf-9 cells infected with the recombinant baculovirus showed the hemagglutinating activity for chicken erythrocytes, and specific positive reactions in indirect immunofluorescence and indirect dot immunoassay. By SDS-PAGE and Western blot analysis, the expressed HN protein with the size of 74 kDa was detected in the cells infected with the recombinant baculovirus. To evaluate the immunogenicity of expressed HN protein, the chicken inoculated with the lysates of the Sf-9 cells were examined by hemagglutination inhibition and ELISA tests. The substantial levels of antibody responses were detected in both assays. The HN protein expressed in baculovirus recombinant system could be utilized for the development of diagnostic measures for Newcastle disease in poultry, and these results on HN recombinant baculovirus will expedite the development of recombinant ND vaccines.
Animals
;
Antibody Formation
;
Baculoviridae*
;
Blotting, Western
;
Chickens
;
Clone Cells*
;
Cloning, Organism*
;
DNA
;
Electrophoresis, Polyacrylamide Gel
;
Enzyme-Linked Immunosorbent Assay
;
Erythrocytes
;
Fluorescent Antibody Technique, Indirect
;
Hemagglutination
;
HN Protein
;
Immunoassay
;
Korea
;
Newcastle disease virus*
;
Newcastle Disease*
;
Poultry
;
Vaccines
9.Infectivity of bovine leukemia virus to Korean native goats I. antibody responses and syncytium assay for Korean native goats experimentally infected with bovine leukemia virus.
Young Sung CHO ; Moo Hyung JUN ; Kyung Soo CHANG ; Young Do CHOI
Journal of the Korean Society of Virology 1993;23(2):153-163
No abstract available.
Animals
;
Antibody Formation*
;
Cattle
;
Enzootic Bovine Leukosis*
;
Giant Cells*
;
Goats*
;
Leukemia Virus, Bovine*
10.A case of congenital goiter with congenital hypothyroidism due to organification defect.
Ik Hee LEE ; Sung Yong JUNG ; Thi Hyung PARK ; Sa Jun CHUNG ; Chang Il AHN
Journal of the Korean Pediatric Society 1993;36(7):1002-1008
We experienced a case of congenital goiter with congenital hypothyroidism in 45 day-old male, who complained of respiratory difficulty and anterior neck mass. After admission, he was diagnosed congenital hypothyroidism by the clinical manifestations and laboratory tests including biochemistry, radioimmunoassay, radioisotope study, perchlorate discharge test, and bone radiography. We obtained positive finding at the perchlorate discharge test and found that his congenital goiter with congenital hypothyroidism was manifested by organification defect. We started treatment with L-thyroxine orally at 6th hospital day. The case was presented with brief review of literatures.
Biochemistry
;
Congenital Hypothyroidism*
;
Goiter*
;
Humans
;
Male
;
Neck
;
Radiography
;
Radioimmunoassay
;
Thyroxine