Effect of quaternary ammonium compounds on microbial contamination levels in dental clinics

The aim of this study was to investigate the change of microbial contamination levels in the different areas and at the different time points after application of a quaternary ammonium compound (QAC) that has mechanical antimicrobial effect. The microbial contamination levels were measured in three different areas; unit chair handle, spit sink area and hand piece holder at different time points using adenosine triphosphate (ATP) monitoring system and ATP surface test kit. Hand piece holder showed the highest level of microbial contamination. In most of the clinics, QAC significantly reduced the levels of microbial contamination, and maintained antimicrobial activity for 4 to 6 months. QAC may be used effectively in dental clinics due to the duration of antimicrobial effect and the minimal exposure of chemicals and further studies are needed with large sample size.

Effect of quaternary ammonium compounds on microbial contamination levels in dental clinics

The aim of this study was to investigate the change of microbial contamination levels in the different areas and at the different time points after application of a quaternary ammonium compound (QAC) that has mechanical antimicrobial effect. The microbial contamination levels were measured in three different areas; unit chair handle, spit sink area and hand piece holder at different time points using adenosine triphosphate (ATP) monitoring system and ATP surface test kit. Hand piece holder showed the highest level of microbial contamination. In most of the clinics, QAC significantly reduced the levels of microbial contamination, and maintained antimicrobial activity for 4 to 6 months. QAC may be used effectively in dental clinics due to the duration of antimicrobial effect and the minimal exposure of chemicals and further studies are needed with large sample size.

Seropositive rate of the anti-hepatitis A immunoglobulin G antibody in maintenance hemodialysis subjects from two hospitals in Korea

BACKGROUND/AIMS@#Hepatitis A virus (HAV) is a self-limiting infectious disease, but 1% of subjects develop fulminant hepatitis. The prevalence of the anti-HAV immunoglobulin G (IgG) antibody in hemodialysis subjects in Korea remains unknown. The purpose of this study was to describe and compare the seropositive rate of anti-HAV antibody among hemodialysis subjects in two hospitals according to age group.@*METHODS@#A total of 170 hemodialysis subjects were evaluated for the seropositive rate of the anti-HAV IgG antibody and its titer.@*RESULTS@#Of the 170 maintenance hemodialysis subjects in two hospitals (Kangnam 92 vs. Chuncheon 78), 79 (46.5%) were male. The mean age was 53.2 years old, and 94.1% of the subjects were over 40 years old. The median vintage of hemodialysis was 29.0 months. Anti-HAV antibody was found in 163 subjects (95.9%), with no significant difference between the two areas (Kangnam 97.8% [n = 90] vs. Chuncheon 93.6% [n = 73]). Subjects younger than 40 years old showed a seropositive rate of 50%, while the seropositive rate increased with age for subjects aged 40 or older (p for trend < 0.001). Seropositive subjects from Kangnam showed a higher anti-HAV antibody titer than those from Chuncheon (median: Kangnam 14.2 vs. Chuncheon 11.7). Only age influenced seropositivity. The only factor that influenced the antibody level was the location of hospital (p < 0.001).@*CONCLUSIONS@#The seropositive rate of the anti-HAV antibody in hemodialysis subjects was 95%, which is similar to findings in the general population. Active immunization against hepatitis A is strongly recommended for hemodialysis subjects under 40 years of age after anti-HAV testing.

Anti-Rods and Rings Autoantibodies in a Patient With Hepatitis C Virus Infection

No abstract available.

Effects of Platelet Lysate Preparations on the Proliferation of HaCaT Cells

BACKGROUND: Standard protocols are lacking for the preparation of platelet lysates (PL) as an alternative to using fetal bovine serum as a cell culture supplement. This study aimed to establish optimum conditions for preparing PL for use in cell cultures. METHODS: Cell density in three pooled platelet concentrates (PC) were adjusted to 1x10(12)/L and 2x10(12)/L. PL was prepared from PC by 1 to 3 freeze-thaw (FT) cycles. HaCaT cells were cultured in media supplemented with 5% or 10% PL. Cell numbers were estimated using a Cell Counting Kit-8 (CCK-8; Dojindo Laboratories, Japan). Growth factors were quantified by using the Luminex 200 system (Luminex Corporation, USA). RESULTS: Cell proliferation rates in the presence of PLs were similar when prepared from PCs of both cell densities. The rates were higher in media containing 5% PL than 10% PL when prepared by two FT cycles. Concentrations of vascular endothelial growth factor (VEGF), platelet-derived growth factor-AB/BB (PDGF-AB/BB), PDGF-AA, and epidermal growth factor (EGF) were significantly higher in PL prepared from PC with a cell density of 2x10(12)/L than 1x10(12)/L PC. However, only VEGF and PDGF-AA concentrations in PLs were correlated with HaCaT cell counts. CONCLUSIONS: The 5% PL from PC with a cell density of 1x10(12)/L prepared by two FT cycles treatment was the most effective condition that supported steady HaCaT cell proliferation. Our finding may be useful for preparing PL-supplemented cell culture media.

Progress of in vitro factor VIII coagulant activity from 0 to 8 hours after reconstitution

BACKGROUND: Continuous infusion of factor VIII (FVIII) is a more cost-effective method for treating hemophilia A than intermittent bolus injection. However, there is currently no specific data in Korea about the progress of in vitro FVIII coagulant activity (FVIII:C) after reconstitution from its lyophilized form. METHODS: Three commercial FVIII concentrate products (two recombinant FVIII and one plasma-derived) were used. In vitro FVIII:C was measured at 0, 2, 4, 6, and 8 hours following reconstitution in both the indoor light-exposed and light-shielded groups. RESULTS: For the three drugs, in vitro FVIII:C decreased over the 8 hours following reconstitution (P<0.001). The decline of FVIII:C was linear (P<0.001). In vitro FVIII:C for the indoor light-exposed groups was 95.3+/-1.9% and 90.6+/-2.5% after 4 and 8 hours following reconstitution, respectively, compared to baseline activity. In the light-shielded group, FVIII:C was 95.4+/-1.1% and 90.9+/-1.7% of the baseline activity after 4 and 8 hours, respectively. There was no statistical difference between FVIII:C in the indoor light-exposed and light-shielded groups (P=0.849). CONCLUSION: In vitro FVIII:C decreased after reconstitution, but activity was maintained at over 90% of the baseline value during 8 hours. Exposure to indoor light did not accelerate the loss of FVIII:C over the experimental time. This result indicates that CI with FVIII is available in 8-hour intervals, with no indoor light-exposure precautions needed.

Comparison of ABO Antibody Titers on the Basis of the Antibody Detection Method Used

BACKGROUND: Detection methods for ABO antibody (Ab) titers vary across laboratories, and the results are different depending on the method used. We aimed to compare titer values using different detection methods for the measurement of ABO Ab titers. METHODS: For ABO Ab detection, pooled group A or B red blood cells (RBCs) were reacted with each of 20 sera from blood groups A, B, or O without dithiothreitol treatment. The room-temperature (RT) incubation technique and the indirect antiglobulin test (IAT) were used in the tube test and gel card test. Flow cytometry (FCM) was performed by using anti-IgM and anti-IgG Abs. RESULTS: Regardless of the blood groups tested, the FCM assay with anti-IgM showed the highest titer compared to the tube test and gel card test with RT incubation in both. The tube test with IAT showed a higher titer than the gel card test with IAT (Gel-IAT) or FCM with anti-IgG in blood group A and B, while Gel-IAT showed the highest titer relative to the other tests, only for the anti-A Ab in blood group O. CONCLUSIONS: There were significant differences in the titers depending on the detection method used, and each method showed a different detection capacity for each ABO Ab depending on the ABO blood group tested. Therefore, caution should be exercised in interpreting ABO Ab titer results, taking into consideration the detection method used and the blood group.

Basic Data for Reference Intervals in Koreans for Parameters Produced by Multiplate Platelet Function Analyzer

BACKGROUND: The Multiplate analyzer (Dynabyte GmbH) has been recently introduced as a platelet function test for patients taking antiplatelet drugs. The study aimed at providing basic data for determining the reference interval of parameters produced by Multiplate in Koreans and to study the factors that influence those parameters. METHODS: Blood was collected from 35 healthy volunteers (female 18, male 17) into tubes containing hirudin or 3.2% sodium citrate. Whole blood platelet aggregations triggered by adenosine-5'-diphosphate (ADP), ADP-high sensitive (ADP+PGE1 only in hirudin samples), arachidonic acid (AA), collagen or thrombin receptor activator peptide (TRAP) were investigated using Multiplate according to the manufacturer's instructions. Data from healthy volunteers for the area under the curve (AUC) were determined from the central 95th percentile of the results. RESULTS: The values of AUC in hirudin samples for all agonists were significantly higher than those in sodium citrate samples. The AUC values in hirudin (sodium citrate) samples were as follows: ADP 38-107 (18-119) U; ADP+PGE1 16-91 U; AA 64-156 (32-117) U; collagen 53-112 (26-108) U; and TRAP 81-163 (49-149) U. The parameters from Multiplate were significantly correlated with leukocyte counts, but not with hematocrit levels. CONCLUSIONS: Although our data were derived from only 35 subjects, the results are expected to be helpful in determining the reference interval at a single institute and may serve as basic data for future cumulative data of reference intervals from multiple institutes in Korea.

A Comparative Study of Biological and Analytical Variabilities in Automated Blood Cell Analysis / 대한임상병리학회지

BACKGROUND: The National Committee for Clinical Laboratory Standards (NCCLS) recommends that the analytical variability must not exceed 25% of the biological variability in automated blood cell analysis. This study was conducted to determine whether routine automated blood cell analysis by Coulter STKS (Coulter Corp., Miami, FL, U.S.A) comforms with the NCCLS's recommendations. METHODS: Routine CBC analysis with STKS was performed on 22 healthy volunteers. The tests included calculating WBC, RBC, hemoglobin, MCV, platelet, MPV, and percentages of the granulocytes, lymphocytes, and monocytes. Blood samples were collected twice in one week interval to study the total variability. For the analytical variability, blood samples from 12 subjects were tested twice immediately after venipuncture for within-run variability, and samples from 10 subjects were tested immediately and 6 hours after venipuncture for within-day variability. The analytical variability was calculated as the sum of within-run and within-day variabilities. The biological variability was calculated by subtracting the analytical variability from total variability. The ratios of analytical and biological variabilities were calculated by dividing the analytical variability by the biological variability. RESULTS: Ratios of analytical and biological variabilities were as follows: 0.22 for WBC, 0.20 for RBC, 0.21 for hemoglobin, 0.39 for platelet, 1.98 for MPV, 0.07 for %granulocyte, 0.11 for %lymphocyte, and 1.81 for %monocyte. The ratio for MCV was not obtained because the analytical variability exceeded total variability. CONCLUSIONS: The analytical variability did not exceed 25% of the biological variability in all test categories except platelet, MPV and the percentage of monocyte. Thus, it is recommended that the analytic variability of all test categories be reduced so as to be in conformity with the NCCLS' recommendations.