The purpose of this study was to evaluate and compare the shear bond strengths and failure sites of metal brackets bonded with chemically cured adhesive and light-cured adhesive. 10 brackets were bonded on prepared enamel surfaces with Transbond(R) (Unitek/3M; U.S.A.) light-cured orthodontic adhesive and another 10 brackets were bonded with Ortho-one(R) (Bisco: U.S.A.) chemically cured orthodontic adhesive. 24 hours after bonding, the Instron universal testing machine was used to measure the shear bond strengths. The failure sites were examined under streoscopic microscope. The results were as follows: 1. The mean shear bond strength of metal brackets bonded with light-cured adhesive was lower than that of metal brackets bonded with chemically cured adhesive, but the difference was not statistically significant (p<0.05). 2. Regardless of the type of adhesives, the brackets were failed primarily at the bracket baseadhesive interface. 3. Bonding of metal brackets with light-cured adhesive is considered to be clinically acceptable.
Adhesives* ; Dental Cements ; Dental Enamel

The purpose of this study was to evaluate the in vitro shear bond strengths to enamel and the failure sites of three ceramic brackets and one metal bracket in combination with light cured orthodontic adhesive. The brackets were divided into four groups. Each ceramic bracket group had different bonding mechanisms with adhesive. Group A; metal bracket with foil-mesh base (control group) Group B; ceramic bracket with micromechanical retention Group C; ceramic bracket with chemical bonding Group D; ceramic bracket with mechanical retention and chemical bonding. Forty extracted human lower first premolars were prepared for bonding and 10 brackets for each group were bonded to prepared enamel surfaces with Transbond(R) light cured orthodontic adhesive. Twenty four hours after bonding, the Instron universal testing machine was used to test the shear bond strength of brackets to enamel. After debonding, brackets and enamel surfaces were examined under stereoscopic microscope to determine the failure sites. Statistical analysis of the data was carried out with ANOVA test and Scheffe test using SPSS PC+. The results were as follows: 1. There were statistically significant differences in mean shear bond strengths of three ceramic bracket groups (p<0.05). Shear bond strengths of group C and D were significantly higher than that of group B and shear bond strength of group C was significantly higher than that of group D. 2. Group C and D both had significantly higher shear bond strengths than metal bracket (group A), but there were no significant differences in shear bond strengths between group A and B (p<0.05). 3. The failure sites of four bracket groups were also different. Group C and D failed primarily at enamel-adhesive interface, but group A and B failed primarily at bracket base-adhesive interface. 4. Among all ceramic bracket groups, group B was very similar to metal bracket in the aspect of shear bond strength and failure site.
Adhesives ; Bicuspid ; Ceramics* ; Dental Cements ; Dental Enamel ; Humans

No abstract available.
Cause of Death* ; Fever* ; Humans

No abstract available.
Infarction* ; Retrospective Studies*

Hemorrhagic fever with renal syndrome(HFRS) is an infectious disease showing diverse clinical manifestations according to different serotypes of hantavirus. Korean hemorrhagic fever(KHF), HFRS caused by Hantaan or Seoul virus in Korea, shows diverse clinical manifestations even in the same serotype of hantavirus. On the assumption that the antigenicity, nucleotide and amino acid sequence diversity of hantaviruses, as well as immune response diversity of individual KHF patient may be present, this study was performed to analyse the genetic diversity of hantaviruses isolated from patients with KHF. In the 13 samples(9 strains of hantavirus isolated from bloods, urines or autopsy tissue of KHF patients and 4 serums of KHF patients), hantaviral RNAs were extracted, cDNAs of partial M segment were amplified by RT-PCR using genus-reactive primer, amplified cDNAs were analysed by direct sequencing method, and then the nucleotide and deduced amino acid sequences were compared with previously known sequences of four serotypes of hantavirus isolated from rodent hosts and each other by the computer assistance. The results were as follows. The nucleotide and amino acid sequences of 11 samples among the 13 human isolates showed 90.3-95.5%, 86.7-97.9%, the other 1 sample 82.7%, 71.9% homology respectively to those of Hantaan virus 76-118 strain, and another 1 sample showed 83.7%, 75.3% homology respectively to those of Seoul virus B1 strain isolated from rodent host. The nucleotide and amino acid sequences of 7 among 12 Hantaan samples showed differences within 5%, 10% respectively each other and high genetic similarities, but those of the other 5 among 12 Hantaan samples showed low genetic similarities each other. In conclusion, hantaviruses isolated from KHF patients showed genetic diversity compared with previously known hantaviruses isolated from rodent hosts.
Amino Acid Sequence ; Autopsy ; Communicable Diseases ; DNA, Complementary ; Fever ; Genetic Variation ; Hantaan virus ; Hantavirus ; Hemorrhagic Fever with Renal Syndrome* ; Humans ; Korea ; RNA ; Rodentia ; Seoul virus

Between January, 1990, and December, 1994, 105 elderly patients(over the age of sixty) were referred to the Division of Nephrology at the Seoul National University Hospital as acute renal failure(ARF) (serum creatinine >1.7mg/dL, patients who had been diagnosed to have acute on chronic renal failure were excluded). To find out the characteristics of ARF in the elderly, we made a retrospective study of our data. Sufficient data for analysis were available in 101 of these. Among these patients, prerenal failure occured in 5% of the cases, ischemic ATN 34%, toxic ATN 11%, renovascular obstruction 5%, glomerular disease 5%, postrenal failure 15%. Dialysis was required in 31 patients(31%). Twenty four patients were treated by hemodialysis, it was carried out in 1 patient by the peritoneal route, and the other 6 patients were treated by CAVH. The most common indication was hypervolemia(77%). Twenty seven patients died during the period of acute renal failure. The most common cause of death was infection(15 patients), and the others were underlying diseases, pulmonary complications and cardiovascular complications. Oliguria, and chronic underlying disease were poor prognostic factors. There were significant differences between living and died group in APACHE II score(P<0.05). We conclude that ischemic ATN is a more common cause of ARF in the elderly than in the younger, and presence of oliguria and chronic underlying disease are poor prognostic factors.
Acute Kidney Injury* ; Aged* ; APACHE ; Cause of Death ; Creatinine ; Dialysis ; Hemofiltration ; Humans ; Kidney Failure, Chronic ; Lung Diseases ; Mortality ; Nephrology ; Oliguria ; Renal Dialysis ; Retrospective Studies ; Seoul

Recently, it becomes conspicuous that the network should have enough communication bandwidth and be organized with steadiness to operate and support hospital information system successfully. Seoul National University Hospital completed to reconstruct legacy network which had been used since 1995. We had a consultation to diagnose the current problems and reconstructed the network according to the consultation. The design of network architecture was mainly focused on the circuit route in case of error condition and the suitable bandwidth for the easy communication. We also regulated the use of unsuitable protocols which might broadcast inappropriate data packets over the whole network. After 6 months of operation we evaluated the performance of newly constructed network. The average traffic rate from the input port of main servers was 0.5% and that from the output port was 6% separately. The average traffic rate on the overall ATM backbone showed around 1 %.From the result, we concluded that the newly constructed network had such an enough capability supporting hospital information system without any interruption. Furthermore, we expect that it will be sufficient to support the additional traffic increment by PACS and group ware applications.
Hospital Information Systems ; Hospitals, General* ; Information Services* ; Information Systems* ; Seoul*

Eleven hantavirus isolates were obtained by innoculation of viremic blood, urine, or autopsy tissue specimens from ten HFRS patients, and sera were obtained from five patients with HFRS. The disease was diagnosed by clinical manifestations and indirect immunofluorescent antibody technique. We obtained 6 hantaviruses from gene bank. So, we analyzed 22 hantavirus samples to elucidate the genetic diversity. The hantaviral RNAs were extracted and 365 base-pair complementary DNAs of M segment were obtained by reverse transcriptase polymerase chain reaction (RT-PCR) and 326 base-pair by nested PCR. The nucleotide sequences of amplified cDNA fragments were determined by the direct sequencing method using automatic DNA sequence analyzer. We got full M segment sequences of 28 reported hantaviruses with medline searching, and aligned them with our 22 samples, and the phylogenetic analysis for nucleotide and amino acid sequences were done by the Clustal method. The nucleotide and amino acid sequences of Hantaan virus 17 samples showed high (above 90%) homology with 76-118 strain, but 2 samples showed significant differences with 76-118 strain and with other 17 samples. The 3 Seoul virus samples showed high intraspecies differences in 1 sample, and showed singnificant differences with SR-11 strain. In phyogenetic tree analysis, Puumala virus and Hantavirus pulmonary syndrome viruses showed high homology, but Hantaan and Seoul viruses showed significant genetic diversity among strains. In conclusion, hantaviruses isolated from HFRS patients showed genetic diversity compared with those isolated from rodent hosts.
Amino Acid Sequence ; Autopsy ; Base Sequence* ; DNA, Complementary ; Genetic Variation ; Hantaan virus ; Hantavirus Pulmonary Syndrome ; Hantavirus* ; Hemorrhagic Fever with Renal Syndrome* ; Humans ; Korea* ; Polymerase Chain Reaction ; Puumala virus ; Reverse Transcriptase Polymerase Chain Reaction ; RNA ; Rodentia ; Seoul virus

No abstract available.
Acid-Base Equilibrium* ; Acidosis*

Hemolytic uremic syndrome (HUS) occurs rarely in adults and its clinical manifestations are not well studied in Korea. We analyzed data from 14 adult patients admitted from 1987 to 1996 who fulfilled three criteria (Coombs negative microangiopathic hemolytic anemia, no artificial heart valve, and creatinine level>1.4mg/dL). No patient died, 3 patients needed dialysis for ESRD at first episode, 2 patients developed CRF, 1 patient had recurrence and progressed to ESRD at the second episode. 7 patients completely recovered their renal function without proteinuria nor hypertension. HUS secondary to other disease had the worst renal survival and patients with colitis had better renal survival. Patient age, sex, platelet counts, white blood cell counts, hemoglobin level, treatment modalities were not significantly associated with renal survival.
Adult* ; Anemia, Hemolytic ; Colitis ; Creatinine ; Dialysis ; Heart, Artificial ; Hemolytic-Uremic Syndrome* ; Humans ; Hypertension ; Kidney Failure, Chronic ; Korea ; Leukocyte Count ; Platelet Count ; Proteinuria ; Recurrence