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Background@#Clinical management of patients infected with hepatitis B virus (HBV) or hepatitis C virus (HCV) relies on the viral load (VL). The Cobas 5800 system (Roche Diagnostics) can determine VLs in 200 and 500 µL samples, but the performance of each protocol has not been compared. We evaluated the performance of both protocols for the HBV and HCV tests. @*Methods@#Precision and linearity were verified using commercial panels. Probit analyses were used to determine limits of detection (LoDs). The results obtained with 336 samples were compared using the 200 and 500 µL protocols. Data from 6,737 retrospective HBV and 768 HCV samples were compared to estimate the effects of the different LoDs on the diagnostic results of the protocols. Correlations between protocols were tested with Spearman’s rank correlation coefficients (rho). @*Results@#The precision and linearity of both protocols were verified. The LoDs for the 200and 500 μL protocols were 6.5 and 2.7 IU/mL for HBV and 29.7 and 8.2 IU/mL for HCV,respectively. The agreement between the protocols ranged from 0.8 to 1.0. The results obtained with the HBV and HCV tests showed a strong correlation (rho = 0.994). Only 0.4% ofHBV and 0.4% of HCV test results were affected by the LoDs of the 200 μL protocol. @*Conclusions@#The Cobas 5800 200 and 500 µL protocols for the HBV DNA and HCV RNA tests demonstrated excellent performance. These findings establish the 200 µL protocol as a new option for low-volume samples, especially for pediatric and difficult-to-bleed patients.
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Background@#Reference materials are essential for the quality assurance of molecular detection methods. We developed and characterized synthetic norovirus GI and GII RNA reference materials. @*Methods@#Norovirus GI and GII RNA sequences including the ORF1–ORF2 junction region were designed based on 1,495 reported norovirus sequences and synthesized via plasmid preparation and in vitro transcription. The synthetic norovirus GI and GII RNAs were evaluated using six commercial norovirus detection kits used in Korea and subjected to homogeneity and stability analyses. A multicenter study involving five laboratories and using four commercial real-time PCR norovirus detection assays was conducted for synthetic norovirus RNA characterization and uncertainty measurements. @*Results@#The synthetic norovirus GI and GII RNAs were positively detected using the six commercial norovirus detection kits and were homogeneous and stable for one year when stored at –20°C or –70°C. All data from the five laboratories were within a range of 1.0 log copies/μL difference for each RNA, and the overall mean concentrations for norovirus GI and GII RNAs were 7.90 log copies/μL and 6.96 log copies/μL, respectively. @*Conclusions@#The synthetic norovirus GI and GII RNAs are adequate for quality control based on commercial molecular detection reagents for noroviruses with high sequence variability. The synthetic RNAs can be used as reference materials in norovirus molecular detection methods.
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Background@#To ensure valid results of big data research in the medical field, the input laboratory results need to be of high quality. We aimed to establish a strategy for evaluating the quality of laboratory results suitable for big data research. @*Methods@#We used Korean Association of External Quality Assessment Service (KEQAS) data to retrospectively review multicenter data. Seven measurands were analyzed using commutable materials: HbA1c, creatinine (Cr), total cholesterol (TC), triglyceride (TG), alpha-fetoprotein (AFP), prostate-specific antigen (PSA), and cardiac troponin I (cTnI). These were classified into three groups based on their standardization or harmonization status. HbA1c, Cr, TC, TG, and AFP were analyzed with respect to peer group values. PSA and cTnI were analyzed in separate peer groups according to the calibrator type and manufacturer, respectively. The acceptance rate and absolute percentage bias at the medical decision level were calculated based on biological variation criteria. @*Results@#The acceptance rate (22.5%–100%) varied greatly among the test items, and the mean percentage biases were 0.6%–5.6%, 1.0%–9.6%, and 1.6%–11.3% for all items that satisfied optimum, desirable, and minimum criteria, respectively. @*Conclusions@#The acceptance rate of participants and their external quality assessment (EQA) results exhibited statistically significant differences according to the quality grade for each criterion. Even when they passed the EQA standards, the test results did not guarantee the quality requirements for big data. We suggest that the KEQAS classification can serve as a guide for building big data.
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Background@#Nasal swabs and saliva samples are being considered alternatives to nasopharyngeal swabs (NPSs) for detecting severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2); however, few studies have compared the usefulness of nasal swabs, NPSs, and saliva samples for detecting SARS-CoV-2 and other respiratory virus infections. We compared the positivity rates and concentrations of viruses detected in nasal swabs, NPSs, and saliva samples using cycle threshold (Ct) values from real-time PCR tests for respiratory viruses. @*Methods@#In total, 236 samples (48 five-rub and 10 10-rub nasal swabs, 96 NPSs collected using two different products, 48 saliva swabs, and 34 undiluted saliva samples) from 48 patients (34 patients with SARS-CoV-2 and 14 with other respiratory virus infections) and 40 samples from eight healthy controls were obtained. The PCR positivity and Ct values were compared using Allplex Respiratory Panels 1/2/3 and Allplex SARS-CoV-2 real-time PCR. @*Results@#NPSs showed the lowest Ct values (indicating the highest virus concentrations); however, nasal and saliva samples yielded positive results for SARS-CoV-2 and other respiratory viruses. The median Ct value for SARS-CoV-2 E gene PCR using nasal swab samples collected with 10 rubs was significantly different from that obtained using nasal swabs collected with five rubs (Ct=24.3 vs. 28.9; P=0.002), but not from that obtained using NPSs. @*Conclusions@#Our results confirm that the NPS is the best sample type for detecting respiratory viruses, but nasal swabs and saliva samples can be alternatives to NPSs. Vigorously and sufficiently rubbed nasal swabs can provide SARS-CoV-2 concentrations similar to those obtained with NPSs.
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Purpose@#The purpose of this study was to explore professional self-concept, work environment, resilience and intention to stay for nurses in university hospitals, and to identify the relationship between these variables and factors that influence intention to stay. We aimed to provide basic data to develop measures for increasing intention to stay. @*Methods@#This study used a descriptive design, the subjects were nurses who worked for more than 1 year at a university hospital with 744 beds, located in city C. Data were collected using a structured questionnaire from 120 nurses. The data collection period were from September 15 to 30, 2020. The data were analysed using the SPSS/WIN 25.0 program. @*Results@#There was a positive correlation between the subject's intention to stay and the professional self-concept (r=.57, p<.001), the nursing working environment (r=.29, p=.002), and resilience (r=.50, p<.001). Significant factors influencing the subject's intention to stay was the sense of satisfaction (β=.40, p<.001), a sub-factor of professional self-concept, indicating the higher the satisfaction level, the higher the intention to stay. The regression model explained 45.0% of the variance of the outcome variable (F=9.64, p<.001). @*Conclusion@#Sense of satisfaction was identified as a factor impacting the intention to stay. Therefore, it is necessary to develop and to apply intervention programs to improve the satisfaction of the professional self-concept in order to increase the nurses’ intention to stay.
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Background@#Accurate serum creatinine (Cr) concentration measurement is essential for evaluating kidney function. In 2011, the Korean Association of External Quality Assessment Service (KEQAS) launched an accuracy-based Cr proficiency testing (ABCr PT) survey. We analyzed long-term data of the KEQAS ABCr PT survey collected between 2011 and 2019 to assess recent trends in Cr assays in Korea. @*Methods@#The ABCr PT survey including three commutable fresh-frozen serum samples was performed twice a year. The target Cr concentration was assigned using isotope-dilution mass spectrometry. We analyzed data obtained from the participating laboratories, calculated the yearly bias, and evaluated bias trends for the major reagents and instruments. Outliers were excluded from all analysis. @*Results@#The mean percentage bias based on the total data of all participating laboratories was 10.8% in the 2011-A survey and 0.2% in 2019-B survey. Bias for the major reagents and instruments differed depending on the manufacturer. Enzymatic assays generally showed desirable bias ranging from –3.9% to 3.2% at all Cr concentrations and lower interlaboratory variability than non-enzymatic assays (enzymatic vs. non-enzymatic, 3.3%– 7.2% vs. 6.3%–9.1%). @*Conclusions@#Although the mean percentage bias of Cr assays tends to decrease over time, it is necessary to continuously strive to improve Cr assay accuracy, especially at low concentrations.
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Background@#Rotaviruses are a major cause of pediatric gastroenteritis. The rotavirus P[6] genotype is the most prevalent genotype isolated from Korean neonates but has rarely been reported in other countries. Histo-blood group antigen (HBGA) is known to play an important role in rotavirus infection. We investigated the relationship between rotavirus genotype and HBGA-Lewis blood type in Korean children and explored the reasons for the predominance of rotavirus P[6] strain in Korean neonates. @*Methods@#Blood and stool samples were collected from 16 rotavirus-infected patients. Rotavirus G (VP7) and P (VP4) genotyping was performed using reverse transcription-PCR and sequencing. Lewis antigen phenotypes (Lea /Leb ) were tested, and HBGA-Lewis genotype was determined by sequencing the secretor (FUT2) and Lewis (FUT3) genes. Deduced amino acid sequences and three-dimensional structures of the VP8* portion of the rotavirus VP4 protein were analyzed. @*Results@#All P[6] rotaviruses were isolated from neonates under one month of age, who were negative or weakly positive for the Leb antigen. However, 10 of the 11 non-P[6] rotaviruses were isolated from older children who were Leb antigen-positive. The VP8* amino acid sequences differed among P[6], P[4], and P[8] genotypes. Korean P[6] strains showed a unique VP8* sequence with amino acid substitutions, including Y169 > L169, which differed from the sequences of P[6] strains from other countries. @*Conclusions@#The predominance of the rotavirus P[6] genotype in Korean neonates may be related to the interaction between HBGA-Lewis antigen and the VP8* portion of the VP4 protein, and this information will be helpful in future neonatal vaccine development.
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Red blood cell (RBC) alloimmunization varies across human populations and ethnic groups. We evaluated the characteristics of RBC alloimmunization and compared the risk of alloimmunization in Korean patients with myelodysplastic syndrome (MDS) and liver cirrhosis (LC), two representative diseases in which chronic transfusion is required. In total, 115 MDS patients and 202 LC patients transfused with RBCs between 2013 and 2015 were retrospectively included. Twenty patients (6.3%) were newly alloimmunized (five MDS patients, 4.3%; 15 LC patients, 7.4%). The median number of RBC units transfused in alloimmunized patients was nine (interquartile range, 4–15 units). As the number of transfused RBC units increased, the cumulative risk of alloimmunization was higher in LC than in MDS patients (P=0.001). The most common alloantibody detected in patients was anti-E (45%), followed by anti-c (17%), anti-e (10%), anti-C (7%), anti-Fyb (7%), and anti-Jka (7%). The present data indicate the need for matching of extended RBC antigens (Rh, Duffy, and Kidd systems) for chronically transfused patients with MDS and LC in Korea.
Subject(s)
Humans , Erythrocytes , Ethnicity , Korea , Liver Cirrhosis , Liver , Myelodysplastic Syndromes , Retrospective StudiesABSTRACT
PURPOSE: Although laparoscopic adjustable gastric bands are considered a standard treatment for severe obesity, their use remains controversial. We evaluated rates of band explantation and the incidences of complications leading to and following band explantation. MATERIALS AND METHODS: This retrospective review was performed on patients that underwent adjustable gastric band explantation. For each of the three groups of patients that underwent explantation, we compared demographic and anthropometric data, band duration in situ, operative approach, and morbidities. RESULTS: Between January 2009 and October 2018, a total of 267 patients underwent primary laparoscopic adjustable gastric band surgery. Of these 267 patients, 99 (37.1%) underwent band explantation. Numbers (%) of patients in the slippage (SL), band erosion (BE), and intolerance (IT) groups were 13 (13.1%), 39 (39.4), and 47 (47.5%), respectively. Mean %EBMIL values at explantation in these groups were 74.6±45.5, 79.7±40.3, and 36.1±46.0, respectively (p<0.001), and mean times for maintaining bands in situ were 45.1±28.0, 39.4±24.3, and 51.2±22.7 months, respectively. Isolated band removal was performed for slippage (SLi, n=12), band erosion (BEi, n=39), and intolerance (ITi, n=31). The numbers (%) of patients in the SLi, BEi, and ITi groups that experienced a surgical complication (Clavien-Dindo class ≥1) were 0 (0.0%), 24 (61.5%), and 3 (9.7%), respectively (p<0.001). In the BEi group, four patients (4/39, 10.3%) underwent reoperation after AGB removal. CONCLUSION: During our 10 years of experience, 37.1% of adjustable gastric band had to be removed. Intra-abdominal abscess and intragastric bleeding were rare but serious complications after explantation. Potential candidates for adjustable gastric band should be informed of the high long-term risk of band explantation and its associated morbidities.
Subject(s)
Humans , Abdominal Abscess , Hemorrhage , Incidence , Obesity, Morbid , Reoperation , Retrospective StudiesABSTRACT
PURPOSE: Few studies investigated roles of body mass index (BMI) on gastric cancer (GC) risk according to Helicobacter pylori infection status. This study was conducted to evaluate associations between BMI and GC risk with consideration of H. pylori infection information. MATERIALS AND METHODS: We performed a case-cohort study (n=2,458) that consists of a subcohort, (n=2,193 including 67 GC incident cases) randomly selected from the Korean Multicenter Cancer Cohort (KMCC) and 265 incident GC cases outside of the subcohort. H. pylori infection was assessed using an immunoblot assay. GC risk according to BMI was evaluated by calculating hazard ratios (HRs) and their 95% confidence intervals (95% CIs) using weighted Cox hazard regression model. RESULTS: Increased GC risk in lower BMI group (< 23 kg/m²) with marginal significance, (HR, 1.32; 95% CI, 0.98 to 1.77) compared to the reference group (BMI of 23-24.9 kg/m²) was observed. In the H. pylori non-infection, both lower (< 23 kg/m²) and higher BMI (≥ 25 kg/m²) showed non-significantly increased GC risk (HR, 10.82; 95% CI, 1.25 to 93.60 and HR, 11.33; 95% CI, 1.13 to 113.66, respectively). However, these U-shaped associations between BMI and GC risk were not observed in the group who had ever been infected by H. pylori. CONCLUSION: This study suggests the U-shaped associations between BMI and GC risk, especially in subjects who had never been infected by H. pylori.
Subject(s)
Body Mass Index , Cohort Studies , Helicobacter pylori , Helicobacter , Stomach NeoplasmsABSTRACT
Diffuse alveolar hemorrhage (DAH) is a rare manifestation of trauma or long bone fracture. A relationship between fat embolism and DAH has been reported. A 73-year-old female developed sudden cardiac arrest during a femur fracture operation. Cardiopulmonary resuscitation (CPR) was repeated for about 130 minutes. During CPR, blood was detected in the endotracheal tube. Diffuse patch ground glass opacity appearance and increased pulmonary artery with bulging of interventricular septum toward the left ventricle were detected on a chest computed tomography scan. After full supportive care including ventilator therapy, the patient's condition became stabilized and she was extubated after 7 days. We report a case of DAH in the course of a suspected fat embolism during femur fracture operation. Although DAH is a rare manifestation of fat embolism, early diagnosis and aggressive treatment likely can decrease morbidity and mortality.
Subject(s)
Aged , Female , Humans , Cardiopulmonary Resuscitation , Death, Sudden, Cardiac , Early Diagnosis , Embolism , Embolism, Fat , Femur , Fractures, Bone , Glass , Heart Ventricles , Hemorrhage , Mortality , Pulmonary Artery , Thorax , Ventilators, MechanicalABSTRACT
BACKGROUND: The aim of this study was to comparatively evaluate the bactericidal effects of copper, brass (copper 78%, tin 22%), and stainless steel against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VREFM), and multidrug-resistant Pseudomonas aeruginosa (MRPA). METHODS: The isolates (MRSA, VREFM, MRPA) used in this study were mixed wild type 3 strains isolated from patients treated at Uijeongbu St. Mary's Hospital in 2017. These strains showed patterns of multidrug resistance. The lyophilized strains were inoculated into and incubated for 24 hr in tryptic soy broth at 35℃. The initial bacterial inoculum concentration was adjusted to 105 CFU/mL. A 100-mL bacterial suspension was incubated in containers made of brass (copper 78%, tin 22%), copper (above 99% purity), and stainless steel at 35℃. Viable counts of bacteria strains were measured for 9 days. RESULTS: In this study, the bactericidal effects of copper and brass on MRSA, VREFM, and MRPA were verified. The bactericidal effect of stainless steel was much weaker than those of copper and brass. The bactericidal effect was stronger on MRPA than on MRSA or VREFM. CONCLUSION: To prevent cross infection of multidrug resistant bacteria in hospitals, further studies of longer duration are needed for testing of copper materials on objects such as door knobs, faucets, and bed rails.
Subject(s)
Humans , Bacteria , Copper , Cross Infection , Drug Resistance, Multiple , Enterococcus faecium , Methicillin-Resistant Staphylococcus aureus , Pseudomonas aeruginosa , Stainless Steel , TinABSTRACT
BACKGROUND: The returning time of inpatient specimen analysis is usually slow because phlebotomists deliver all the collected specimens at the end of their work cycle. In addition, manual specimen reception further delays the reporting time and imposes a heavy workload on the technical staff, thus compromising effectiveness. Therefore, we have created an automated specimen reception system to tackle testing delays and enhance the efficiency and quality of specimen collection and handling. METHODS: In May 2015, the pre-analytical processing of inpatient samples was renovated. We automated the specimen reception in parallel with barcode printing and introduced pneumatic tubes to deliver samples for routine chemistry tests. We compared the reporting time of the automated system with that of the manual system and analyzed the distribution pattern of the specimens according to handling time. RESULTS: The median reporting time was advanced by 41 minutes, from 09:33 AM to 08:52 AM for the manual and automated reception, respectively. Moreover, with the reduction in hands-on time, the blood specimens reached the laboratory immediately after phlebotomy, thereby improving the processing efficiency by spreading out the interval during which the specimens arrived in the laboratory. Additionally, the new system allowed the identification of the phlebotomist who collected the specimens and tracking the specimens from collection to test result. CONCLUSIONS: With the introduction of our automatic reception system, the reporting time was considerably reduced. Therefore, the satisfaction of the clinician and the technical staff was improved.
Subject(s)
Humans , Chemistry , Inpatients , Phlebotomy , Specimen HandlingABSTRACT
As part of the immunoserology program of the Korean Association of External Quality Assessment Service, we organized two trials on the external quality assessment of hepatitis viral markers in 2016 and 2017. The hepatitis viral antigens and antibodies program consisted of 10 test items. We delivered two and three types of pooled sera specimens to 965 and 965 institutions for the first and second trials of external proficiency testing in 2016, respectively. The number of participating laboratories was 915 (94.8%) and 913 (95.0%) in the first and second trials in 2016, respectively. We also delivered three kinds of pooled sera specimens to 936 and 1,015 institutions for the first and second trials of external proficiency testing in 2017, respectively. The number of participating laboratories was 920 (98.3%) and 996 (98.1%) in the first and second trials in 2017, respectively. The most commonly tested items were hepatitis B surface antigen, followed by the antibodies to hepatitis B surface antigen, anti-hepatitis C virus, hepatitis B envelope antigen, antibodies to hepatitis B envelope antigen, anti-hepatitis A virus and antibodies to hepatitis B core antigen. The most frequently used methods for detecting viral markers were the chemiluminescence immunoassay and the electrochemiluminescence immunoassay, but they yielded a few-false positive results due to the matrix effect. The immunochromatographic assay yielded false-negative results for anti-hepatitis A virus due to low sensitivity. Continuous improvement in the quality of viral hepatitis testing through participation in the survey seems necessary.
Subject(s)
Antibodies , Antigens, Viral , Biomarkers , Hepatitis A , Hepatitis B , Hepatitis B Core Antigens , Hepatitis B Surface Antigens , Hepatitis B virus , Hepatitis C , Hepatitis , Immunoassay , Chromatography, Affinity , Korea , Laboratory Proficiency Testing , LuminescenceABSTRACT
We evaluated the performance of a recently developed immunoassay, Elecsys vitamin D total II assay (Roche Diagnostics GmbH, Germany). Precision, linearity, and comparison studies were performed according to the Clinical and Laboratory Standards Institute guidelines. Control materials, linearity materials, and patient samples were used for the evaluation. For the correlation study, liquid chromatography-tandem mass spectrometry was used as the comparative method. Total coefficients of variations of the analyte were between 5.1% and 9.6%. The results of linearity evaluation were also acceptable for the range tested. Correlations with comparative methods were good; however, the mean values of the Elecsys vitamin D assay were higher than those of liquid chromatography-tandem mass spectrometry. The overall analytical performance of the Elecsys vitamin D total II assay is acceptable for the immunology analyzer. Therefore, the Elecsys vitamin D total II assay is expected to be widely used.
Subject(s)
Humans , Allergy and Immunology , Immunoassay , Mass Spectrometry , Methods , Statistics as Topic , Vitamin D , VitaminsABSTRACT
We have evaluated the performance of a recently developed immunoassay analyzer, ADVIA Centaur XPT (Siemens, Germany). Precision, linearity, and comparison studies were performed according to the CLSI guidelines. The test items evaluated were ferritin, folate, human epidermal growth factor receptor 2/neu, homocysteine, vitamin B₁₂, B-type natriuretic peptide, creatine kinase–myocardial band, myoglobin, procalcitonin, troponin I. Bio-Rad control materials, linearity materials, and patients' samples were used for the evaluation. For the correlation study, ADVIA Centaur XP (Siemens) were used as comparative methods. The total coefficients of variations (CVs) of the analytes were between 2.5% and 7.0%. The results of linearity evaluation were also acceptable for the range tested. Correlations with comparative methods were good. The overall analytical performance of ADVIA Centaur XPT is acceptable for the immunology analyzer. Therefore, ADVIA Centaur XPT is expected to be widely used.
Subject(s)
Humans , Allergy and Immunology , Creatine , Ferritins , Folic Acid , Homocysteine , Immunoassay , Myoglobin , Natriuretic Peptide, Brain , ErbB Receptors , Statistics as Topic , Troponin I , VitaminsABSTRACT
BACKGROUND: We aimed to assess the performance of the five creatinine-based equations commonly used for estimates of the glomerular filtration rate (eGFR), namely, the creatinine-based Chronic Kidney Disease Epidemiology Collaboration (CKD-EPIcr), Asian CKD-EPI, revised Lund–Malmö (revised LM), full age spectrum (FAS), and Korean FAS equations, in the Korean population. METHODS: A total of 1,312 patients, aged 20 yr and above who underwent ⁵¹Cr-EDTA GFR measurements (mGFR), were enrolled. The bias (eGFR–mGFR) and precision (root mean square error [RMSE]) were calculated. The accuracy (P30) of four eGFR equations was compared to that of the CKD-EPIcr equation. P30 was defined as the percentage of patients whose eGFR was within±30% of the mGFR. RESULTS: The mean bias (mL·min⁻¹·1.73 m⁻²) of the five eGFR equation was as follows: CKD-EPIcr, -0.6; Asian CKD-EPI, 2.7; revised LM, -6.5; FAS, -2.5; and Korean FAS, -0.2. The bias of the Asian CKD-EPI, revised LM, and FAS equations showed a significant difference from zero (P<0.001). The RMSE values were as follows: CKD-EPIcr, 15.6; Asian CKD-EPI, 15.6; revised LM, 17.9; FAS, 16.3; and Korean FAS, 15.8. There were no significant differences in the P30 except for the Asian CKD-EPI equation: CKD-EPIcr, 76.6%; Asian CKD-EPI, 74.7%; revised LM, 75.8%; FAS, 76.0%; and Korean FAS, 75.8%. CONCLUSIONS: The CKD-EPIcr and Korean FAS equations showed equivalent analytical and clinical performances in the Korean adult population.
Subject(s)
Adult , Humans , Asian People , Bias , Cooperative Behavior , Creatinine , Epidemiology , Glomerular Filtration Rate , Renal Insufficiency, ChronicABSTRACT
The canonical Wnt pathway is critical for embryonic stem cell (ESC) pluripotency and aberrant control of β-catenin leads to failure of exit from pluripotency and lineage commitments. Hence, maintaining the appropriate level of β-catenin is important for the decision to commit to the appropriate lineage. However, how β-catenin links to core transcription factors in ESCs remains elusive. C-terminal-binding protein (CtBP) in Drosophila is essential for Wnt-mediated target gene expression. In addition, Ctbp acts as an antagonist of β-catenin/TCF activation in mammals. Recently, Ctbp2, a core Oct4-binding protein in ESCs, has been reported to play a key role in ESC pluripotency. However, the significance of the connection between Ctbp2 and β-catenin with regard to ESC pluripotency remains elusive. Here, we demonstrate that C-terminal-binding protein 2 (Ctbp2) associates with major components of the β-catenin destruction complex and limits the accessibility of β-catenin to core transcription factors in undifferentiated ESCs. Ctbp2 knockdown leads to stabilization of β-catenin, which then interacts with core pluripotency-maintaining factors that are occupied by Ctbp2, leading to incomplete exit from pluripotency. These findings suggest a suppressive function for Ctbp2 in reducing the protein level of β-catenin, along with priming its position on core pluripotency genes to hinder β-catenin deposition, which is central to commitment to the appropriate lineage.
Subject(s)
Drosophila , Embryonic Stem Cells , Gene Expression , Mammals , Transcription Factors , Wnt Signaling PathwayABSTRACT
TonEBP belongs to the Rel family of transcription factors and plays important roles in inflammation as well as kidney homeostasis. Recent studies suggest that TonEBP expression is also involved in differentiation of several cell types such as myocytes, chondrocytes, and osteocytes. In this study, we investigated the roles of TonEBP during adipocyte differentiation in 3T3-L1 cells. TonEBP mRNA and protein expression was dramatically reduced during adipocyte differentiation. Sustained expression of TonEBP using an adenovirus suppressed the formation of lipid droplets as well as the expression of FABP4, a marker of differentiated adipocytes. TonEBP also inhibited the expression of PPARγ, a known master regulator of adipocytes. RNAi-mediated knock down of TonEBP promoted adipocyte differentiation. However, overexpression of TonEBP did not affect adipogenesis after the initiation of differentiation. Furthermore, TonEBP expression suppressed mitotic clonal expansion and insulin signaling, which are required early for adipocyte differentiation of 3T3-L1 cells. These results suggest that TonEBP may be an important regulatory factor in the early phase of adipocyte differentiation.
Subject(s)
Humans , 3T3-L1 Cells , Adenoviridae , Adipocytes , Adipogenesis , Chondrocytes , Homeostasis , Inflammation , Insulin , Kidney , Lipid Droplets , Muscle Cells , Osteocytes , RNA, Messenger , Transcription FactorsABSTRACT
BACKGROUND: Second-generation thyroglobulin immunometric assays (Tg-IMAs) have been developed with improved sensitivity. Our aim was to compare the diagnostic value of Tg-IMA measurements using a Kryptor (BRAHMS AG) kit (Tg-K) and an ACCESS (Beckman Coulter) kit (Tg-A) with that of the first-generation Tg measurement using a Tg-plus (BRAHMS AG) kit (Tg+). METHODS: We enrolled 82 differentiated thyroid cancer patients who underwent total thyroidectomy with radioactive iodine remnant ablation and who underwent diagnostic whole body scan using recombinant human thyroid stimulating hormone (rhTSH). The Tg+, Tg-K, and Tg-A were measured before rhTSH administration during levothyroxine treatment (suppressed Tg) from the same sample. Serum Tg+ was measured after rhTSH stimulation (stimulated Tg). RESULTS: Suppressed Tg+ was more significantly correlated with suppressed Tg-K (R²=0.919, P<0.001) than with suppressed Tg-A (R²=0.536, P<0.001). The optimal cut-off values of suppressed Tg+, Tg-K, and Tg-A for predicting stimulated Tg+ of 1 ng/mL were 0.3, 0.2, and 0.2 ng/mL, respectively. The sensitivity, specificity, and accuracy of suppressed Tg+ were 67%, 100%, and 90%, respectively; those of suppressed Tg-K were 83%, 90%, and 88%; those of suppressed Tg-A were 96%, 82%, and 87%, respectively. The positive predictive and negative predictive values of Tg+ were 100% and 87%, respectively; those of Tg-K were 79% and 92%; and those of Tg-A were 73% and 98%. CONCLUSION: We could not clearly demonstrate which kit had better diagnostic performance after comparison of first-generation Tg measurements with Tg-IMA measurements. Also, there were kit-to-kit variations between Tg-IMA kits. Suppressed Tg measured by Tg-IMA was insufficient to completely substitute for a stimulated Tg measurement.