Abstract: Previously, we explored the epidemic pattern and molecular characterization of noroviruses (NoVs) isolated in Chungnam, Korea in 2008, and the present study extended these observations to 2009 and 2010. In Korea, NoVs showed the seasonal prevalence from late fall to spring, and widely detected in preschool children and peoples over 60 years of age. Epidemiological pattern of NoV was similar in 2008 and in 2010, but pattern in 2009 was affected by pandemic influenza A/H1N1 2009 virus. NoV-positive samples were subjected to sequence determination of the capsid gene region, which resolved the isolated NoVs into five GI (2, 6, 7, 9 and 10) and eleven GII genotypes (1, 2, 3, 4, 6, 7, 8, 12, 13, 16 and 17). The most prevalent genotype was GII.4 and occupied 130 out of 211 NoV isolates (61.6%). Comparison of NoV GII.4 of prevalent genotype in these periods with reference strains of the same genotype was conducted to genetic analysis by a phylogenetic tree. The NoV GII.4 strains were segregated into seven distinct genetic groups, which are supported by high bootstrap values and previously reported clusters. All Korean NoV GII.4 strains belonged to either VI cluster or VII cluster. The divergence of nucleotide sequences within VI and VII intra-clusters was > 3.9% and >3.5%, respectively. The "Chungnam(06-117)/2010" strain which was isolated in June 2010 was a variant that did not belong to cluster VI or VII and showed 5.8-8.2%, 6.2-8.1% nucleotide divergence with cluster VI and VII, respectively.
Abstract: Rapid and accurate detection of norovirus is essential for the prevention and control of
norovirus outbreaks. This study compared the effectiveness of a new immunochromatographic
assay kit (SD BIOLINE Norovirus; Standard Diagnostics, Korea) and real-time reverse
transcription-PCR (RT-PCR) for detecting norovirus in fecal specimens. Compared
with real-time RT-PCR, the new assay had sensitivity, specificity, positive predictive value,
and negative predictive value of 76.5% (52/68), 99.7% (342/343), 98.1% (52/53), and 95.5%
(342/358), respectively. The sensitivity of the assay was 81.8% (18/22) for GII.3 and 75.7%
(28/37) for GII.4. None of the 38 enteric virus-positive specimens (3 for astrovirus, 5 for enteric
adenovirus, and 30 for rotavirus) tested positive in the cross-reactivity test performed
by using this assay. The new immunochromatographic assay may be a useful screening
tool for the rapid detection of norovirus in sporadic and outbreak cases; however, negative
results may require confirmatory assays of greater sensitivity.
Abstract: Background
A peptide nucleic acid (PNA) probe-based real-time PCR (PNAqPCR⢠TB/NTM detection kit; PANAGENE, Korea) assay has been recently developed for the simultaneous detection of Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM) in clinical specimens. The study was aimed at evaluation of the performance of PNA probe-based real-time PCR in respiratory specimens.
Methods
To evaluate potential cross-reactivity, the extracted DNA specimens from Mycobacterium species and non-mycobacterial species were tested using PNA probe-based real-time PCR assay. A total of 531 respiratory specimens (482 sputum specimens and 49 bronchoalveolar washing fluid specimens) were collected from 230 patients in July and August, 2011. All specimens were analyzed for the detection of mycobacteria by direct smear examination, mycobacterial culture, and PNA probe-based real-time PCR assay.
Results
In cross-reactivity tests, no false-positive or false-negative results were evident. When the culture method was used as the gold standard test for comparison, PNA probe-based real-time PCR assay for detection of MTBC had a sensitivity and specificity of 96.7% (58/60) and 99.6% (469/471), respectively. Assuming the combination of culture and clinical diagnosis as the standard, the sensitivity and specificity of the new real-time PCR assay for detection of MTBC were 90.6% (58/64) and 99.6% (465/467), respectively. The new real-time PCR for the detection of NTM had a sensitivity and specificity of 69.0% (29/42) and 100% (489/489), respectively.
Conclusions
The new real-time PCR assay may be useful for the detection of MTBC in respiratory specimens and for discrimination of NTM from MTBC.
Abstract: Hand-foot-and-mouth disease (HFMD) and herpangina are commonly prevalent illness in young children. They are similarly characterized by lesions on the skin and oral mucosa. Both diseases are associated with various enterovirus serotypes. In this study, enteroviruses from patients with these diseases in Korea in 2009 were isolated and analyzed. Demographic data for patients with HFMD and herpangina were compared and all enterovirus isolates were amplified in the VP1 region by reverse transcription-polymerase chain reaction and sequenced. Among the enterovirus isolates, prevalent agents were coxsackievirus A16 in HFMD and coxsackievirus A5 in herpangina. More prevalent months for HFMD were June (69.2%) and May (11.5%), and June (40.0%) and July (24.0%) for herpangina. Age prevalence of HFMD patients with enterovirus infection was 1 year (23.1%), 4 years (19.2%), and over 5 years (19.2%). However, the dominant age group of herpangina patients with enterovirus infection was 1 year (48.0%) followed by 2 years (28.0%). Comparison of pairwise VP1 nucleotide sequence alignment of all isolates within the same serotypes revealed high intra-type variation of CVA2 isolates (84.6--99.3% nucleotide identity). HFMD and herpangina showed differences in demographic data and serotypes of isolated enteroviruses, but there was no notable difference in amino acid sequences by clinical syndromes in multiple comparison of the partial VP1 gene sequence.
Abstract: Dietary phytochemicals as adjuvants have been suggested to play important roles in enhancing chemotherapeutic potential owing to multitargeted chemopreventive properties and lack of substantial toxicity. Here, we investigated the efficacy of the combined treatment of various phytochemicals with the anticancer drug clofarabine in malignant mesothelioma MSTO-211H cells and normal mesothelial Met-5A cells. The combined treatment of resveratrol and clofarabine produced a synergistic antiproliferative effect in MSTO-211H cells, but not in Met-5A cells. In MSTO-211H cells, the nuclear accumulation of Sp1 and the levels of p-Akt, Sp1, c-Met, cyclin D1, and p21 were effectively decreased by the combined treatment of them. In combination with clofarabine, the ability of resveratrol to reduce the contents of Sp1 and its target gene products was also evident in a time- and dose-dependent experiment. The inhibition of phosphoinositide 3-kinase using Ly294002 augmented a decrease in the p21 level induced by their combination, but it showed no significant effects on expression of Sp1 and cyclin D1. Taken together, the data provide evidence that the synergistic antiproliferative effect of resveratrol and clofarabine is linked to the inhibition of Akt and Sp1 activities, and suggest that this combination may have therapeutic value in treatment of malignant mesothelioma.
Abstract: House dust mites produce potent allergens that exacerbate asthma in sensitized patients, whom are recommended to practice
allergen avoidance within their home environment. We tested the effect of activated charcoal impregnated fibers on house dust
mite survival. One hundred live adult house dust mites (Dermatophagoides pteronyssinus) were added to eight culture dishes
preequilibrated at room temperature (n = 4) and 70% humidity (n = 4) containing house dust mite food and active charcoal fibers. At 10 minute intervals, live and dead house dust mites were counted. All house dust mites instantly attached to the activated charcoal fibers and started to shrink almost immediately. There were no live house dust mites present as early as 40 minutes in some dishes while after 190 minutes all house dust mites were dead. In conclusion, activated charcoal fibers, if incorporated into bedding items, have the potential to control house dust mites in the indoor environment.
Abstract: Although most enterovirus infections are not serious enough to be life threatening, several enteroviruses such as enterovirus 71 are responsible for severe, potentially life-threatening disease. The epidemic patterns of enteroviruses occur regularly during the year, but they may change due to environmental shifts induced by climate change due to global warming. Therefore, enterovirus epidemiological studies should be performed continuously as a basis for anti-viral studies. A great number of synthesized antiviral compounds that work against enteroviruses have been developed but only a few have demonstrated effectiveness in vivo. No proven effective antiviral agents are available for enterovirus disease therapy. The development of a new antiviral drug is a difficult task due to poor selective toxicity and cost. To overcome these limitations, one approach is to accelerate the availability of other existing antiviral drugs approved for antiviral effect against enteroviruses, and the other way is to screen traditional medicinal plants.
Abstract: Genetic diversity and antiviral activity for five common antiviral drugs of echovirus (ECV) 5 isolated in Korea have been described. The present study extended these tests to a Korean ECV 18 isolate. An outbreak of aseptic meningitis caused by the ECV 18 isolate was reported in Korea in 2005, marking the first time this virus had been identified in the country since enterovirus surveillance began in 1993. Using a sample isolated from stool specimen of a 5-year-old male patient with aseptic meningitis, the complete genome sequence was obtained and was compared it with the Metcalf prototype strain. Unlike the ECV5 isolate, the 3â'untranslated region had the highest identity value (94.2%) at the nucleotide level, while, at the amino acid level, the P2 region displayed the highest identity value (96.9%). These two strains shared all cleavage sites, with the exception of the 2B/2C site, which was RQ/NN in the Metcalf strain but RQ/NS in the Korean ECV 18 isolate. In Vero cells infected with the Korean ECV 18 isolate, no cytotoxicity was observed in the presence of azidothymidine, acyclovir, amantadine, lamivudine, or ribavirin, when the drugs were administered at a CC50 value >100 μg/mL. Of the five drugs, only amantadine (IC50: 4.97 ± 0.77 μg/mL, TI: 20.12) and ribavirin (IC50: 7.63 ± 0.87 μg/mL, TI: 13.11) had any antiviral activity against the Korean ECV 18 isolate in the five antiviral drugs. These antiviral activity effects were similar with results of the Korean ECV5 isolate.
Abstract: Previously, we explored the epidemic pattern and molecular characterization of enteroviruses isolated in Chungnam, Korea from 2005 to 2006. The present study extended these observations to 2008 and 2009. In this study, enteroviruses showed similar seasonal
prevalent pattern from summer to fall and age distribution to previous investigation. The most prevalent month was July: 42.9% in 2008 and 31.9% in 2009. The highest rate of enterovirus38 positive samples occurred in children <1-year-old-age. Enterovirus-positive samples were subjected to sequence determination of the VP1 region, which resolved the isolated enteroviruses into 10 types in 2008 (coxsackievirus A4, A16, B1, B3, echovirus 6, 7, 9, 11, 16, and 30) and 8 types in 2009 (coxsackievirus A2, A4, A5, A16, B1, B5, echovirus 11, and enterovirus 71). The most prevalent enterovirus serotype in 2008 and 2009 was echovirus 30 and coxsackievirus B1, respectively, whereas echovirus 18 and echovirus 5 were the most prevalent types in 2005 and 2006, respectively. Comparison of coxsackievirus B1 and B5 of prevalent enterovirus type in Korea in 2009 with reference strains of each same serotype were conducted to genetic analysis by a phylogenetic tree. The sequences of coxsackievirus B1 strains segregated into four distinct clusters (A, B, C, and D) with some temporal and regional sub-clustering. Most of Korean coxsackievirus B1 strains in 2008 and 2009 were in cluster D, while only â"Kor08-CVB1-001CNâ" was cluster C. The coxsackievirus B5 strains segregated in five distinct genetic groups (clusters Aâ-E) were supported by high bootstrap values. The Korean strains isolated in 2001 belonged to cluster D, whereas Korean strains isolated in 2005 and 2009 belonged to cluster E. Comparison of the VP1 amino acid sequences of the Korean coxsackievirus B5 isolates with reference strains revealed amino acid sequence substitutions at nine amino acid sequences (532, 562, 570, 571, 576â-578, 582, 583, and 585).
Abstract: A major problem of long-term antiviral therapy in chronic hepatitis B patients is the emergence of hepatitis B virus (HBV) mutations associated with drug resistance. Recently, a new array using Peptide Nucleic Acids (PNAs), which are synthetic nucleic acid analogues, was developed for the detection of HBV mutations at six different codon positions associated with lamivudine (LAM) and adefovir (ADV) resistance. We compared the PNA array with direct sequencing and reverse hybridization (INNO-LiPA) in 73 samples obtained from chronic hepatitis B patients. The PNA array detected mutations associated with LAM and/or ADV resistance in 60 (82.2%) of the 73 samples. The overall concordance rate of PNA array and INNO-LiPA comparing direct sequencing was 99.5% and 98.2%, respectively. Complete concordance rate between PNA array and INNO-LiPA was 92.7%. The PNA array assay results were comparable with INNO-LiPA for detection of HBV mutations associated with antiviral resistance.
Abstract: An outbreak of echovirus 5 (ECV 5) occurred in Korea in 2006, marking the first time this virus had been identified in the country since enterovirus surveillance began in 1993. Using a sample isolated from a young male patient with sepsis-like symptoms, we performed sequencing of the Korean ECV 5 strain and compared it with a prototype strain (Noyce). At the nucleotide level, the P1 region (85.3%) had the highest identity value; at the amino acid level, the P3 region (98.0%) had the highest identity value. The two strains shared all cleavage sites, with the exception of the VP1/2A site, which was TY/GA in the Noyce strain but TR/GA in the Korean ECV 5 isolate. In Vero cells infected with the Korean ECV 5 isolate, no cytotoxicity was observed in the presence of azidothymidine, acyclovir, amantadine, lamivudine, or ribavirin, when the drugs were administered at a CC50 value >100 ug/mL. Of the five drugs, only amantadine (IC50: 1 +/- 0.42 ug/mL, TI: 100) and ribavirin (IC50: 22 +/- 1.36 ug/mL, TI: 4.55) had any antiviral activity against the Korean ECV 5 isolate.
Abstract: Noroviruses are the enteric pathogens most commonly responsible for infectious gastroenteritis and outbreaks of foodborne illness. The GII.4 norovirus, in particular, is responsible for the majority of epidemics. Here, we present data on the distribution of norovirus genotypes in Chungnam, Korea, in 2008, measure genetic variation among GII.4 strains, and compare Korean GII.4 variants with reference strains based on the 237-bp junction of ORF1 and ORF2. We detected 139 different strains, which formed two distinct genetic clusters with significant sequence diversity. One Korean cluster (2008-Korea_a) showed high similarity to the Sakai cluster that appeared in Japan and Europe in 2006. The other cluster (2008-Korea_b) was unique and unrelated to previously reported clusters. Genotype GII.4 was confirmed as the predominant cause of norovirus epidemics in Korea. Foodborne norovirus infections, on the other hand, were generally caused by emerging GII.4 genetic variants similar to those responsible for global epidemics.
Abstract: Evaluation of the primary etiologic agents that cause aseptic meningitis outbreaks may provide valuable information regarding the prevention and management of aseptic meningitis. In Korea, an outbreak of aseptic meningitis caused by echovirus type 30 (E30) occurred from May to October in 2008. In order to determine the etiologic agent, CSF and/or stool specimens from 140 children hospitalized for aseptic meningitis at Soonchunhyang University Cheonan Hospital between June and October of 2008 were tested for virus isolation and identification. E30 accounted for 61.7% (37 cases) and echovirus 6 accounted for 21.7% (13 cases) of all the human enteroviruses (HEVs) isolates (60 cases in total). For the molecular characterization of the isolates, the VP1 gene sequence of 18 Korean E30 isolates was compared pairwise using the MegAlign with 34 reference strains from the GenBank database. The pairwise comparison of the nucleotide sequences of the VP1 genes demonstrated that the sequences of the Korean strains differed from those of lineage groups A, B, C, D, E, F and G. Reconstruction of the phylogenetic tree based on the complete VP1 nucleotide sequences resulted in a monophyletic tree, with eight clustered lineage groups. All Korean isolates were segregated from other lineage groups, thus suggesting that the Korean strains were a distinct lineage of E30, and a probable cause of this outbreak. This manuscript is the first report, to the best of our knowledge, of the molecular characteristics of E30 strains associated with an aseptic meningitis outbreak in Korea, and their respective phylogenetic relationships.
Abstract: We evaluated the SD Bioline Influenza Ag A/B/A(H1N1) Pandemic test kit and compared it with real-time RT-PCR for its ability to detect H1N1 2009. The sensitivity and specificity of the test kit for H1N1 2009 were 77% and 100%, respectively.
Abstract: Accurate and rapid diagnosis of Pandemic Influenza A/H1N1 2009 virus (H1N1 2009) infection is important for the prevention and control of influenza epidemics and the timely initiation of antiviral treatment. This study was conducted to evaluate the performance of several diagnostic tools for the detection of H1N1 2009. Flocked nasopharyngeal swabs were collected from 254 outpatients of suspected H1N1 2009 during October 2009. This study analyzed the performances of RealTime ready Inf A/H1N1 Detection Set (Roche), Influenza A (H1N1) Real-Time Detection Kit (Bionote), Seeplex Influenza A/B OneStep Typing set (Seeplex reverse transcriptase PCR [RT-PCR]), BinaxNow Influenza A & B test kit (Binax rapid antigen test [RAT]) and SD BIOLINE Influenza Ag kit (SD RAT). Roche and Bionote real-time RT-PCR showed identical results for the H1N1 2009 hemagglutinin gene.
Compared with real-time RT-PCR, the sensitivities and specificities were 83.7% and 100% for Seeplex RT-PCR, 64.5% and 94.7% for Binax RAT, and 69.5% and 100% for SD RAT. The sensitivities of Seeplex RT-PCR, Binax RAT and SD RAT in patients aged over 21 years were 73.7%, 47.4% and 57.9%, respectively. The sensitivities of Seeplex RT-PCR, Binax RAT and SD RAT on the day of initial symptoms were mostly lower (68.8%, 56.3% and 31.3%, respectively). In conclusion, multiplex RT-PCR and RAT for the detection of H1N1 2009 were significantly less sensitive than real-time RT-PCR. Also, a negative RAT may require more sensitive confirmatory assays, because it cannot be ruled out from influenza infection.
Abstract: House dust mites produce inhalant allergens of importance to allergic patients. We measured the major group 1 allergens, Der p 1 and Der f 1, from the house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farina, respectively in 100 randomly selected domestic homes from Cheonan, Korea. Dust samples were collected by vacuuming from the living room floor and 1 mattress in each home. Der p 1 and Der f 1 were measured by double monoclonal ELISA. Der p 1 levels were very low, with geometric mean levels for floors and mattresses being 0.11 microgram/g (range: 0.01-4.05) and 0.14 microgram/g (range: 0.01-30.0), respectively. Corresponding levels of Der f 1 were higher, 7.46 microgram/g (range: 0.01-262.9) and 10.2 microgram/g (range: 0.01-230.9) for floors and mattresses, respectively. D. farinae appears to be the dominant house dust mite in Cheonan.
Abstract: OBJECTIVE: The serum S100 protein has been known to reflect the severity of neuronal damage. The purpose of this study was to assess the prognostic value of the serum S100 protein by Elecsys S100 immunoassay in patients with subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH) and to establish reference value for this new method. METHODS: Serum S100 protein value was measured at admission, day 3 and 7 after bleeding in 42 consecutive patients (SAH : 20, ICH : 22) and 74 healthy controls, prospectively. Admission Glasgow coma scale (GCS) score, Hunt & Hess grade and Fisher grade for SAH, presence of intraventricular hemorrhage, ICH volume, and outcome at discharge were evaluated. Degrees of serum S100 elevation and their effect on outcomes were compared between two groups. RESULTS: Median S100 levels in SAH and ICH groups were elevated at admission (0.092 versus 0.283 microg/L) and at day 3 (0.110 versus 0.099 microg/L) compared to healthy controls (0.05 microg/L; p<0001). At day 7, however, these levels were normalized in both groups. Time course of S100 level in SAH patient was relatively steady at least during the first 3 days, whereas in ICH patient it showed abrupt S100 surge on admission and then decreased rapidly during the next 7 days, suggesting severe brain damage at the time of bleeding. In ICH patient, S100 level on admission correlated well with GCS score (r=-0.859; p=0.0001) and ICH volume (r=0.663; p=0.001). A baseline S100 level more than 0.199 microg/L predicted poor outcome with 92% sensitivity and 90% specificity. Logistic regression analyses showed Ln (S100) on admission as the only independent predictor of poor outcome (odd ratio 36.1; 95% CI, 1.98 to 656.3). CONCLUSION: Brain damage in ICH patient seems to develop immediately after bleeding, whereas in SAH patients it seems to be sustained for few days. Degree of brain damage is more severe in ICH compared to SAH group based on the S100 level. S100 level is considered an independent predictor of poor outcome in patient with spontaneous ICH, but not in SAH. Further study with large population is required to confirm this result.
Abstract: BACKGROUND & AIMS: Although autoimmune pancreatitis (AIP) responds well to corticosteroid therapy, relapse during maintenance corticosteroid therapy or after the withdrawal of corticosteroid treatment is not uncommon. To date, the factors related to relapse of AIP have not been fully explored. METHODS: To determine the clinical and genetic predictors relating to the relapse of AIP, we evaluated clinical factors, HLA polymorphisms, and the amino acid sequences in 40 patients with AIP. RESULTS: At a median follow-up period of 40 months (range, 12-67 months), relapse developed in 13 of 40 patients with AIP (33%), in whom complete remission was achieved with oral corticosteroid therapy. Among demographics, clinical characteristics in the initial diagnosis of AIP, we could not find any clinical predictor for relapse of AIP; however, in amino acid sequence analysis for relapse of AIP, the substitution of aspartic acid to nonaspartic acid at residue 57 of DQbeta1 showed a significant association with relapse of AIP (nonrelapse group, 29.6%; relapse group, 100%; P = .00003; odds ratio, 3.38; 95% confidence interval, 1.9-6.0). There was a significant difference in the timing of relapse of AIP, according to density of the nonaspartic acid residue at DQbeta1 57 (nonaspartic acid homozygosity: mean +/- SD, 6.7 +/- 4.2 months; nonaspartic acid heterozygosity: mean +/- SD, 33 +/- 11 months; P < .001). CONCLUSIONS: Substitution of aspartic acid to nonaspartic acid at DQbeta1 57 appears to represent a key genetic factor for relapse of AIP (ClinicalTrials.gov number, NCT00444444).
Abstract: Many allergists are currently focusing on the development of new diagnostic tools, and are attempting to improve both the sensitivity and specificity. A multiple allergen simultaneous test-chemiluminescent assay (MASTCLA) is one of the most popular diagnostic tools used in the Republic of Korea. However, there remains controversy among allergists with regard to the cut-off point for a positive result. The present study was conducted in order to determine the validity of MAST-CLA as compared with that of the skin prick test, with particular emphasis on arthropod allergens, on the basis of percentage agreement rates and kappa-values, and also to suggest the optimal positive cutoff points using receiver operating characteristic (ROC) curves. The study was conducted with 97 subjects (54 men, 43 women). Optimal individual cut-off points were calculated as follows; class II for Dermatophagoides farinae, class I for Dermatophagoides pteronyssinus, and trace for a cockroach mix. These findings suggest that attempting to apply optimal individual cut-off points will be a good way of improving diagnostic tests, particularly MAST-CLA.
