[Show abstract][Hide abstract] ABSTRACT: Quantitation of cytomegalovirus (CMV) DNA using real-time PCR has been utilized for monitoring CMV infection. However, the CMV antigenemia assay is still the 'gold standard' assay. There are only a few studies in Korea that compared the efficacy of use of real-time PCR for quantitation of CMV DNA in whole blood with the antigenemia assay, and most of these studies have been limited to transplant recipients.
479 whole blood samples from 79 patients, falling under different disease groups, were tested by real-time CMV DNA PCR using the Q-CMV real-time complete kit (Nanogen Advanced Diagnostic S.r.L., Italy) and CMV antigenemia assay (CINA Kit, ArgeneBiosoft, France), and the results were compared. Repeatedly tested patients were selected and their charts were reviewed for ganciclovir therapy.
The concordance rate of the two assays was 86.4% (Cohen's kappa coefficient value=0.659). Quantitative correlation between the two assays was a moderate (r=0.5504, P<0.0001). Among 20 patients tested repeatedly with the two assays, 13 patients were transplant recipients and treated with ganciclovir. Before treatment, CMV was detected earlier by real-time CMV DNA PCR than the antigenemia assay, with a median difference of 8 days. After treatment, the antigenemia assay achieved negative results earlier than real-time CMV DNA PCR with a median difference of 10.5 days.
Q-CMV real-time complete kit is a useful tool for early detection of CMV infection in whole blood samples in transplant recipients.
Annals of Laboratory Medicine 01/2015; 35(1):99-104. · 1.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Recently, AdvanSureTM kit based on multiplex real-time PCR was developed for simultaneous detection of 14 respiratory viruses. We compared the performance of AdvanSure with those of Seeplex® RV 15 ACE and culture by determining their sensitivity and specificity against a composite reference standard. Four hundred and thirty seven respiratory samples were tested by modified shell vial culture method, RV 15 ACE and AdvanSure. One hundred and fourteen samples (26.2%) out of 437 samples were positive by culture, while additional 91 (20.8%) were positive by AdvanSure or RV15. One hundred twelve of 114 culture positive samples were positive by AdvanSure except 2 samples (1 adenovirus, 1 RSV). Overall, the sensitivities of culture, RV15 and AdvanSure were 74.5%, 89.8%, and 95.1%, respectively. Sensitivities of culture, RV15 and AdvanSure for each virus tested were as follows; 91/100/96% for influenza A, 60/0/100% for influenza B, 63/95/97% for RSV, 69/81/89% for adenovirus, and 87/93/93% for PIV. For viruses not covered by culture, sensitivities of RV15 and AdvanSure were as follows; 77/88% for rhinovirus, 100/100% for coronavirus OC43, 40/100% for coronavirus 229E/NL63, 13/100% for metapneumovirus, and 44/100% for bocavirus. The overall specificities of culture, RV15 and AdvanSure were 100/98.9/99.5%, respectively. Of 45 co-infected specimens, AdvanSure detected 41 specimens (91.1%) as co-infected, while RV15 detected 27 specimens (60.0%) as co-infected. AdvanSure assay demonstrated exquisite performance for the detection of respiratory viruses and will be a valuable tool for the management of respiratory virus infection.
Diagnostic microbiology and infectious disease 05/2014; · 2.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Over the past three decades, a total of USD $121 million in economic losses (fish/shellfish kills) has occurred in the Korean aquaculture industry due to harmful algal blooms (HABs). Paralytic shellfish poisoning (PSP) has also been noted almost every year, closing shellfish farms, and 46 people were poisoned including five people killed by consuming wild mussels. Since 1980, PSP has been officially monitored and managed, and the nationwide control of fish/shellfish kills by HAB species began in 1995. Management and control strategies include both precautionary and emergency measures. Precautionary management includes establishing an observation network and prediction system, an early warning system, and mitigating damage to aquafarms. Along with regular HAB monitoring including species, chlorophyll a, and associated water quality and meteorological parameters, automatic HAB alarm systems equipped with chlorophyll a and turbidity sensors are used in aquafarms as early HAB warnings. Emergency management is essential after a HAB outbreak to prevent fisheries damage. This method includes supplying oxygen to fish, stopping feeding, transferring fish to a safe area, and clay dispersal. Clay dispersion is the prime mitigation technique for HABs in Korea, because clay is natural, nontoxic, inexpensive, and easy to use in field operations. Clay is dispersed over the sea surface using a clay dispensing device to efficiently remove HABs. A third generation (3G) clay dispenser has been developed recently, combining an electrolytic water generator and a clay dispenser, significantly reducing the amount of clay used, resulting in high removal efficiencies. Since using this device, the economic losses from HAB fish kills have dropped >80% in Korea, although the frequency of HABs has increased since 1980. Clay is a natural component, but using too much clay may cause negative impacts on marine organisms and environments. In addition, clay dispersal is not an effective method to control poisoning of fish/shellfish from algal toxins that accumulate in fish and shellfish at low density toxic blooms. Future studies of HAB control should include control of HABs using minimum amounts of clay and practical use of biological control agents.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Various kinds of commercial molecular systems have been developed for fast and more accurate detection of respiratory viruses. Anyplex™ II RV16 [RV16] was designed for simultaneous detection of 16 respiratory viruses using multiplex PCR coupled with TOCE™ technology. OBJECTIVES: To compare the performance of RV16 with those of culture and Seeplex(®) RV15 ACE [RV15] by determining their sensitivity and specificity. STUDY DESIGN: Seven hundred and thirty respiratory samples were tested by modified shell vial culture method, RV16, and RV15. For molecular tests, automated nucleic acid extraction and liquid handling system using MICROLAB Nimbus IVD (Hamilton, USA) was adopted to maximize the workflow and accuracy. Performance of each assay was determined against a composite reference standard. RESULTS: Two hundred and one samples (28%) out of 730 samples were positive by culture, while additional 281 (39%) were positive by RV16 or RV15. Sensitivities of RV16, RV15, and culture for virus tested were as follows: 100/93/63% for influenza A, 90/80/69% for influenza B, 98/94/63% for RSV, 98/52/23% for adenovirus, and 100/75/46% for PIV. For viruses not covered by culture, sensitivities of RV16 and RV15 were as follows: 99/81% for rhinovirus, 92/100% for coronavirus OC43, 100/56% for coronavirus 229E/NL63, 92/88% for metapneumovirus, 100/62% for bocavirus, and 91/91% for enterovirus. Overall, the specificities of culture, RV16, and RV15 (Seegene) were 100/99.9/99.9%. CONCLUSIONS: RV16 assay was superior to culture method and RV15 and will be a promising tool for patient management and public health epidemiology.
Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 06/2013; · 3.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective of this work is to demonstrate the feasibility of inkjet-printed passive components. All passive components such as resistor, capacitor and inductor were inkjet printed on a polyimide (PI) substrate with various functional inks. For the insulator layer, poly-4-vinylphenol (PVP) and cross linking agent (poly(melamine-co-formaldehyde)) were dissolved in an ethanol. A mixture of poly(3,4-ethylene dioxythiophene) doped with polystyrene sulfonated acid (PEDOT:PSS) and ethylene glycol was used to print a resistor. Barium titanate (BaTiO3) and soft ferrite (Ni–Zn) powders were added to the synthesized insulator solution to improve its dielectric and magnetic characteristics, respectively. An RC circuit was also fabricated based on the results of the printed passive components. The printed electric components and circuit were characterized using LCR meter, function generator and digital oscilloscope. The measured responses of the printed RC circuit were in good agreement with estimated results.
[Show abstract][Hide abstract] ABSTRACT: The influenza virus causes seasonal epidemics which are associated with high morbidity and mortality. Rapid diagnostics tests (RDT) are frequently used to make a quick influenza diagnosis to confirm the clinical suspicion, despite their low sensitivity.
Assess the performance of the Sofia Influenza A+B Fluorescence Immunoassay (Quidel, San Diego, CA).
Nasopharyngeal swabs, taken from 241 patients (influenza A (n=73)/B (n=72), negative samples (n=96)) were analyzed using the Sofia Influenza A+B Fluorescence Immunoassay, BinaxNOW Influenza A/B antigen kit (Alere Inc., USA), Directigen EZ Flu A and B (Becton Dickinson, USA), real-time RT-PCR and an influenza virus culture.
There was a significant difference between the performance of rapid antigen tests and the Sofia FIA, when compared to the RT-PCR, in the detection of influenza strain A and B. Indeed, the Sofia FIA displayed sensitivities of 82.2% and 77.8% for strains A and B respectively, whereas sensitivities of BinaxNOW Influenza A/B antigen kit, and Directigen Flu A and B were 54.8%, and 68.5% for influenza A, and 62.5%, and 52.8% for influenza B respectively. The average RT-PCR threshold cycle (C(t)) (±SD) for the Sofia Influenza A+B Fluorescence Immunoassay-positive specimens was higher than those of the BinaxNOW Influenza A/B antigen and the Directigen EZ Flu A and B kit positive specimens.
Compared to other RDTs, the Sofia Influenza A+B Fluorescence Immunoassay is a sensitive, and rapid method for the detection and discrimination between influenza A and B.
Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 08/2012; 55(3):239-43. · 3.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Blood culture is the most valuable laboratory test for the diagnosis of bacteremia and sepsis. The BACTEC FX and BacT/Alert 3D automated blood culture systems are commonly used in Korean health care facilities. A controlled clinical evaluation of the resin-containing BACTEC Plus aerobic (BA) and anaerobic (BN), and the charcoal-containing FAN aerobic (FA) and anaerobic (FN) bottles using blood from intensive care unit (ICU) patients was designed. The performances of these 2 systems with media containing particle absorbing antimicrobial agents were evaluated using the culture positivity rate and time to detection (TTD). TTD was collected using data management systems, either the Epicenter (BD Diagnostic Systems) or the hospital laboratory information system. A total of 1539 four-bottle sets were collected from 270 patients in medical and surgical ICUs. Blood culture samples included 1539 bottles each of BA, BN, FA, and FN, and yielded 113 (7.3%), 90 (5.8%), 104 (6.8%), and 80 (5.2%) positive bacterial or fungal isolates, respectively. There were significant differences between the resin-containing BA and BN samples in culture positivity and also between the charcoal-containing FA and FN samples, especially for Escherichia coli (25/27 versus 17/27, P < 0.05) and Acinetobacter baumannii (14/15 versus 7/15, P < 0.05). Significantly shorter recovery time was observed in BACTEC Plus aerobic bottles than in FAN aerobic bottles (17.2 and 24.7 h, respectively) (P < 0.001).
[Show abstract][Hide abstract] ABSTRACT: Reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) is achieved by viral-mediated transduction of defined transcription factors. Generation of iPSCs is of great medical interest as they have the potential to be a source of patient-specific cells. For the eventual goal of clinical application, it is necessary to overcome the limitations of low reprogramming efficiency and chromosomal abnormalities due to viral DNA integration. In this paper, we summarize the current state of reprogramming technology for generation of iPSCs and also discuss potential approaches to the development of safe iPSCs for personalized cell-based replacement therapy.
The Scientific World Journal 01/2012; 2012:417809. · 1.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Carbapenem-resistant Klebsiella pneumoniae isolates producing K. pneumoniae carbapenemases (KPC) were first reported in the USA in 2001, and since then, this infection has been reported in Europe, Israel, South America, and China. In Korea, the first KPC-2-producing K. pneumoniae sequence type (ST) 11 strain was detected in 2010. We report the case of a patient with a urinary tract infection caused by KPC-2-producing K. pneumoniae. This is the second report of a KPC-2-producing K. pneumoniae infection in Korea, but the multilocus sequence type was ST258. The KPC-2-producing isolate was resistant to all tested β-lactams (including imipenem and meropenem), amikacin, tobramycin, ciprofloxacin, levofloxacin, and trimethoprim-sulfamethoxazole, but was susceptible to gentamicin, colistin, polymyxin B, and tigecycline. The KPC-2-producing isolate was negative to phenotypic extended-spectrum β-lactamase (ESBL) and AmpC detection tests and positive to modified Hodge test and carbapenemase inhibition test with aminophenylboronic acid.
The Korean Journal of Laboratory Medicine 10/2011; 31(4):298-301. · 1.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Some human embryonic stem cell lines have shown genomic instabilities over long-term culture. To study the controversial origin of the SCNT-hES-1 line, which was derived from autologous somatic cell nuclear transfer (SCNT), we compared the expression and methylation patterns of imprinted genes in the SCNT-hES-1 cells with the donor's somatic cells by semi-quantitative RT-PCR, real-time PCR and bisulfite sequencing. Examined imprinted genes were H19, GNAS, SLC22A18, UBE3A and ZNF264 for maternally expressed genes, and IGF2, SNRPN, PEG3, PEG10, MEST, MAGEL2 and ARHI for paternally expressed genes, respectively. We found that the expression of imprinted genes in the SCNT-hES-1 cell line is comparable to that in the donor's somatic cells, and that its methylation patterns are similar to those of other SCNT-products. Therefore, the present study indicates that the SCNT-hES-1 line was derived from SCNT.
International Journal of Molecular Medicine 08/2011; 28(5):697-704. · 1.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: GATA binding protein 3 (GATA3) is a key molecule regulating the balance in the ratio of type 1 helper T (Th1) cells to type 2 helper T (Th2) cells, which is thought to be indicative of the pathogenesis of allergic diseases such as asthma and atopic dermatitis. The aim of this study was to investigate the role of GATA3 in allergic skin inflammation. Transgenic (Tg) mice overexpressing human GATA3 (hGATA3) were produced by the microinjection of pCMV/hGATA3 constructs into fertilized mouse eggs. The hGATA3 gene was successfully expressed at the protein level in the lymph node and thymus of CMV/hGATA3 transfected cells and Tg mice. CMV/hGATA3 Tg mice showed a significant increase in the allergic skin inflammation response such as ear thickness, draining auricular lymph node (aLN) weight, epidermal thickness, inflammatory cell number and Th2 immunoglobulin (Ig) concentration compared to wild-type (WT) mice after phthalic anhydride (PA) treatment. Furthermore, the secretion of Th2 type cytokines was increased by PA treatment in CMV/hGATA3 Tg mice, while the secretion of Th1 type cytokine was suppressed under the same conditions. However, the increased levels of Th2 type cytokines in CMV/hGATA3 Tg mice were almost recovered by the down-regulation of GATA3 expression with D-pinitol treatment. Therefore, these findings suggest that GATA3 could be considered as a potential target regulating the mechanism responsible for the differences in allergic skin inflammation.
International Journal of Molecular Medicine 08/2011; 28(2):171-9. · 1.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Human bocavirus (HBoV) is a newly identified viral pathogen, and its clinical epidemiology and significance in respiratory infections have not yet been completely elucidated. We investigated the prevalence of HBoV infection and the association between viral (HBoV) load and clinical features of the infection in patients of all age-groups.
Nasopharyngeal aspirates from patients with symptoms of respiratory infection were tested for presence of HBoV by using real-time polymerase chain reaction. HBoV-positive patients were categorized into low- and high-viral-load groups using 1.0×10(6) copies/mL as the threshold value of viral load.
Detection rate of HBoV was 4.8% (N=93) in a total of 1,926 samples with peak incidence of infection being observed in patients aged 6-12 months. HBoV infection was more frequently observed in young children, especially, in children aged less than 5 yr, and the HBoV load decreased with increase in age. HBoV was codetected with other respiratory viruses in 17 (18.3%) of the 93 HBoV-positive patients and 15 patients (88.2%) belonged to the low-viral-load group. Patients infected with HBoV alone showed a higher viral load than those patients in whom HBoV was codetected with other respiratory viruses (median load, 3.78×10(5) copies/mL vs. 1.94×10(4) copies/mL, P=0.014). Higher pulse rate (P=0.007) and respiratory rate (P=0.021) were observed in patients with a high-viral-load.
Our results suggest that HBoV may be the causative agent of respiratory infection in the high-viral-load group.
The Korean Journal of Laboratory Medicine 07/2011; 31(3):179-84. · 1.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The incidence of nocardiosis is increasing with the expansion of immunosuppressive therapy and improvement of laboratory diagnostic
methods. Nocardiosis could be fatal in the compromised host. Some Nocardia species are known to be multi-drug resistant. Thus, early recognition and identification of Nocardia species are important for patient treatment and outcome. Recently, we treated a patient with pulmonary and psoas muscle nocardiosis
in a woman taking prednisolone for lupus nephritis; the isolated organism was Nocardia farcinica identified by polymerase chain reaction-restriction fragment length polymorphism testing.
KeywordsNocardiosis–Pulmonary–Psoas muscle–Lupus nephritis–Prednisolone
Rheumatology International 07/2011; 31(7):929-936. · 1.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study was conducted to investigate the immune responses of children with moderate and severe novel influenza A virus (H1N1) pneumonia, and to compare their clinical and immunological findings with those of control subjects.
Thirty-two admitted patients with H1N1 pneumonia were enrolled in the study. The clinical profiles, humoral and cell-mediated immune responses of the 16 H1N1 pneumonia patients who were admitted to the pediatric intensive care unit (severe pneumonia group), 16 H1N1 pneumonia patients admitted to the pediatric general ward (moderate pneumonia group) and 13 control subjects (control group) were measured.
Total lymphocyte counts were significantly lower in patients with H1N1 pneumonia than in the control group (P=0.02). The number of CD4+ T lymphocytes was significantly lower in the severe pneumonia group (411.5±253.5/µL) than in the moderate pneumonia (644.9±291.1/µL, P=0.04) and control (902.5±461.2/µL, P=0.01) groups. However, the number of CD8+ T lymphocytes was significantly higher in the severe pneumonia group (684.2±420.8/µL) than in the moderate pneumonia (319.7±176.6/µL, P=0.02) and control (407.2±309.3/µL, P=0.03) groups. The CD4+/CD8+ T lymphocytes ratio was significantly lower in the severe pneumonia group (0.86±0.24) than in the moderate pneumonia (1.57±0.41, P=0.01) and control (1.61±0.49, P=0.01) groups. The serum levels of IgG, IgM and IgE were significantly higher in the severe pneumonia group than in the 2 other groups.
The results of this study suggest that increased humoral immune responses and the differences in the CD4+ and CD8+ T lymphocyte profiles, and imbalance of their ratios may be related to the severity of H1N1 pneumonia in children.
Korean Journal of Pediatrics 05/2011; 54(5):207-11.
[Show abstract][Hide abstract] ABSTRACT: The interleukin-4 (IL-4) signaling cascade has been identified as a potentially important pathway in the development of allergies. The principal objective of this study was to produce novel transgenic (Tg) mice harboring the luciferase gene under the control of the human IL-4 promoter and the enhancer of IL-4 (CNS-1), in an effort to evaluate three types of allergens including a respiratory sensitizer, vaccine additives, and crude extracts of natural allergens in vivo. A new lineage of Tg mice was generated by the microinjection of pIL-4/Luc/CNS-1 constructs into a fertilized mice egg. The luciferase activity was successfully regulated by the IL-4 promoter in splenocytes cultured from IL-4/Luc/CNS-1 Tg mice. From the first five founder lines, one (#57) evidencing a profound response to ovalbumin was selected for use in evaluating the allergens. Additionally, the lungs, thymus, and lymph nodes of IL-4/Luc/CNS-1 Tg mice evidenced high luciferase activity in response to allergens such as phthalic anhydride (PA), trimellitic anhydride, ovalbumin, gelatin, Dermatophagoides pteronyssinus extracts, and Japanese cedar pollen, whereas key allergy-related indicators including ear thickness, Immunoglobulin E concentration, and the infiltration of inflammatory leukocytes in response to PA were unaltered in the Tg mice relative to the non-Tg mice. Furthermore, the expression levels of endogenous type 2 helper T cells cytokines and proinflammatory cytokines were similarly increased in these organs of IL-4/Luc/CNS-1 Tg mice in response to allergens. These results indicate that IL-4/Luc/CNS-1 Tg mice may be used as an animal model for the evaluation and prediction of the human body response to a variety of allergens originating from the environment and from certain industrial products.