Delay in the diagnosis of Brucella abortus bacteremia in a nonendemic country: a case report.

BACKGROUND: It is challenging to diagnose brucellosis in nonendemic regions because it is a nonspecific febrile disease. The accurate identification of Brucella spp. in clinical microbiology laboratories (CMLs) continues to pose difficulties. Most reports of misidentification are for B. melitensis, and we report a rare case of misidentified B. abortus. CASE PRESENTATION: A 67-year-old man visited an outpatient clinic complaining of fatigue, fever, and weight loss. The patient had a history of slaughtering cows with brucellosis one year prior, and his Brucella antibody tests were negative twice. After blood culture, the administration of doxycycline and rifampin was initiated. The patient was hospitalized due to a positive blood culture. Gram-negative coccobacilli were detected in aerobic blood culture bottles, but the CML's lack of experience with Brucella prevented appropriate further testing. Inaccurate identification results were obtained for a GN ID card of VITEK 2 (bioMérieux, USA) and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) using a MALDI Biotyper (Bruker, Germany). The strain showed 100.0% identity with Brucella spp. according to 16S rRNA sequencing. MALDI-TOF MS peaks were reanalyzed using the CDC MicrobeNet database to determine Brucella spp. (score value: 2.023). The patient was discharged after nine days of hospitalization and improved after maintaining only doxycycline for six weeks. The isolate was also identified as Brucella abortus by genomic evidence. CONCLUSION: Automated identification instruments and MALDI-TOF MS are widely used to identify bacteria in CMLs, but there are limitations in accurately identifying Brucella spp. It is important for CMLs to be aware of the possibility of brucellosis through communication with clinicians. Performing an analysis with an additional well-curated MALDI-TOF MS database such as Bruker security-relevant (SR) database or CDC MicrobeNet database is helpful for quickly identifying the genus Brucella.

SARS-CoV-2 Infectivity and Antibody Titer Reduction for 6 Months After Second Dose of BNT162b2 mRNA Vaccine in Health Care Workers: A Prospective Cohort Study.

Several studies reported that severe acute respiratory syndrome coronavirus-2 antibody levels change over 6 months in participants receiving the vaccination. From the enrolled 272 health care workers (HCWs), blood samples were obtained at 2, 16, and 24 weeks after the second vaccination dose. In the 267 noninfected HCWs, the neutralizing antibodies decreased by 23.9%, and the anti-spike/receptor binding domain antibody decreased by 53.8% at 24 weeks. We observed no significant difference in antibody reduction between the sexes; however, in younger individuals, there was higher antibody formation and lower reduction rates of the neutralizing antibody. In 3 HCWs with breakthrough infections, the antibody levels were relatively low just before the coronavirus disease 2019 infection. In conclusion, as antibody titers decrease over time after the second vaccination dose and HCWs with low antibody titers tend to have a high probability of breakthrough infection, an additional dose should be considered after several months. Blood samples were obtained from health care workers at 2, 16, and 24 weeks after a second vaccination dose. Antibody titers decreased over time and the participants with low antibody titers tended to have a high probability of breakthrough infection.

Reactive Halogen Species-Mediated Electrocatalytic Oxidation of Arsenite(III).

Electrocatalytic advanced oxidation processes have long been considered among of the most viable ways to remediate aquatic contaminants, including As(III). Although direct electrochemical oxidation of As(III) is thermochemically facile, a high reaction rate is not easily achieved because of the competitive oxygen evolution reaction (OER), particularly at high potentials. This study examines the effect of three halides (Cl-, Br-, and I-) on the electrochemical oxidation of As(III) with nanoparticulate TiO2 electrodes in an aqueous bicarbonate solution at pH 8.7. The halides significantly enhance As(III) oxidation kinetics by >4, >8, and >20 times, respectively, under optimal conditions. Faradaic efficiencies of As(V) production (AsV-FEs) are also enhanced by a maximum of 10 times by the halides, even at high potentials at which the OER occurs. Pre-electrolysis of each halide solution produces reactive halogen species (ClO-, BrO-, and I3-). As(III)-spiking of the pre-electrolyzed halide solutions allows simultaneous concentration changes at near-stoichiometric ratios (R2 > 0.98) between each halogen species and As(V). Among the three halides, iodide imparts the strongest effect on As(III) oxidation owing to its lowest redox potential. Finally, technical considerations of reactive-halogen-species-mediated As(III) oxidation are discussed.

Lead, mercury, and cadmium exposures are associated with obesity but not with diabetes mellitus: Korean National Environmental Health Survey (KoNEHS) 2015-2017.

BACKGROUND: Associations of heavy metal exposures with obesity and obesity-related traits have been suggested, while those with nonalcoholic fatty liver disease (NAFLD) and diabetes mellitus (DM) are often inconsistent. METHODS: This study included 3787 adults aged ≥19 years who participated in the Korean National Environmental Health Survey 2015-2017, and investigated the association of toxic heavy metals with metabolic diseases. Lead (Pb), mercury (Hg), and cadmium (Cd) were measured either in urine (uHg, uCd) or total blood (bPb, bHg). Body mass index (BMI) was calculated, and DM cases were identified through a self-answered medication history. Hepatic Steatosis Index (HSI) as a surrogating index of NAFLD, was calculated using hepatic enzyme measurements, including aspartate aminotransferase (AST) and alanine aminotransferase (ALT). RESULTS: Adults in the highest quartile of bPb, bHg, and uHg showed significantly elevated odds of obesity (BMI ≥25 kg/m2), compared to the lowest quartile (OR 1.58 for bPb, 1.92 for bHg, and 1.81 for uHg). HSI was positively correlated with bHg, uHg, and uCd concentrations. The odds of NAFLD (HSI ≥36) were also increased with increasing quartile of bHg, uHg, and uCd concentrations. For DM, bPb showed a significant negative association, while bHg and uCd exhibited non-monotonic and inconclusive associations. CONCLUSIONS: Among the general adult population of Korea, both Pb and Hg exposures were associated with an increased risk of obesity. In addition, both Hg and Cd exposures were associated with increased odds of NAFLD. These metals, however, were not associated with an increased risk of DM.

Characteristics of Korean BCR-ABL1-Negative Myeloproliferative Neoplasms Related to the 2016 WHO Criteria Revision.

BACKGROUND: We aimed to identify changes in the diagnosis and subtype classification of Korean patients with BCR-ABL1-negative MPN related to the revision of the WHO classification in 2016. METHODS: We evaluated 76 Korean patients with BCR-ABL1-negative MPN who underwent diagnostic work-ups, including bone marrow (BM) examinations and JAK2 V617F mutation analysis, from January 2013 to June 2018. Additionally, we reclassified the subtype of 43 patients who were diagnosed based on the WHO 2008 classification. RESULTS: From January 2013 to April 2016, 43 patients were diagnosed with BCR-ABL1-negative MPN (12 PV, 17 ET, 14 PMF) according to the 2008 WHO classification, and from May 2016 to June 2018, 33 patients were diagnosed according to the 2016 classification (15 PV, 11 ET, 7 PMF). With the application of 2016 classification, 3 cases of ET were reclassified as pre-PMF, and the proportion of PV increased from 27.9% to 45.5%. There were significant differences in CBC between pre-PMF and overt PMF, between ET and overt-PMF, but no difference between ET and pre-PMF. CONCLUSIONS: The overall characteristics of BCR-ABL1-negative MPN patients were not significantly different from those of previous reports. 'Masked PV', which could not be diagnosed according to the WHO 2008 classification, may have been diagnosed as PV since 2016 due to the increase in the diagnostic value of the BM findings and the lowering of the hemoglobin (Hb) threshold.

Clinically refined epidemiology of nontuberculous mycobacterial pulmonary disease in South Korea: overestimation when relying only on diagnostic codes.

BACKGROUND: There have been reports of increases in the incidence and prevalence of nontuberculous mycobacterial pulmonary disease (NTM-PD) in several countries, but no studies have analyzed claims data using laboratory tests. This study aimed to estimate the nationwide epidemiology and medical treatments of NTM-PD according to laboratory tests run in Korea. METHODS: Using claims data from the Health Insurance Review and Assessment Service, we analyzed patients with nontuberculous mycobacterium (ICD-10: A31) who were diagnosed from Jan 2007 to Jun 2019. The incidence and prevalence of NTM-PD and whether related laboratory tests were performed were analyzed. Diagnostic code-based NTM-PD patients were defined as patients who had NTM as a diagnosis on at least 2 occasions within 180 days. Clinically refined NTM-PD patients were defined as those excluding hospital-diagnosed patients with acid-fast bacilli (AFB) culture rates less than 5%. Laboratory tests included AFB smears, AFB culture, NTM identification, and drug susceptibility tests (DSTs). RESULTS: A total of 60,071 diagnostic code-based NTM-PD patients were evaluated. Clinically refined NTM-PD included 45,321 patients, excluding 14,750 (24.6%) patients diagnosed in hospitals with low AFB culture rates. The annual incidence per 100,000 population increased from 2.9 cases in 2008 to 12.3 cases in 2018. The annual prevalence per 100,000 population increased from 5.3 cases in 2008 to 41.7 cases in 2018. After removing outliers according to the AFB culture rate, a significant decrease in incidence was observed in women younger than 50 years. Among patients with clinically refined NTM-PD, the test rates for AFB culture, NTM identification, and DST were 84.3%, 59.1%, and 40.4%, respectively. From the outpatient clinic, 17,977 (39.7%) patients were prescribed drugs related to NTM treatment, with a median number of prescriptions of 7 (interquartile range (IQR) 3-11) and a median duration from the diagnosis to end of treatment of 330 (IQR 118-578) days. CONCLUSIONS: Although the incidence and prevalence of NTM-PD are on the rise, the recent surge in women 50 years of age is overestimated in patients not adequately tested. In claim-based studies, there may be limitations in estimating the epidemiological data with only the diagnostic codes.

Strong SARS-CoV-2 Antibody Response After Booster Dose of BNT162b2 mRNA Vaccines in Uninfected Healthcare Workers.

Despite strict guidelines for coronavirus disease 2019 (COVID-19), South Korea is facing its fourth pandemic wave. In this study, by using an automated electrochemiluminescence immunoassay assay, we tracked anti-spike protein receptor-binding domain (anti-S-RBD) antibody titer from the second dose to 2 weeks after the booster dose vaccination. After the second dose, 234 participants had their anti-S-RBD antibody titers decrease over time. We also showed the booster dose (the third dose) increased antibody titer by average 14 (min-max, 2-255)-fold higher compared to the second dose among the 211-booster group participants, therefore, the booster dose could be recommended for low responders to the second dose. Our findings showed a distinct humoral response after booster doses of BNT162b2 mRNA vaccines and may provide further evidence of booster vaccination efficacy. These data will also be helpful in vaccination policy decisions that determine the need for the booster dose.

Evaluation of Five User-Friendly Whole Genome Sequencing Software for Mycobacterium tuberculosis in Clinical Application.

BACKGROUND: Whole genome sequencing (WGS) is an increasingly useful tool for tuberculosis (TB) diagnosis and disease management. In this study, we evaluated the utility of user-friendly WGS tools in reporting resistance profiles and identifying lineages of clinical TB isolates from South Korea. METHODS: Forty clinical samples from TB patients showing discrepancies between their rapid molecular and conventional drug susceptibility tests were used in this study. Among these clinical isolates, 37 strains were successfully evaluated via WGS software, using the GenTB, TB Profiler, PhyResSE, CASTB, and Mykrobe. RESULTS: More accurate and faster susceptibility results could be obtained with isoniazid than with rifampin. Using the phenotypic test as the gold standard, the isoniazid concordance rate between phenotypic drug susceptibility test (DST) and WGS (GenTB: 45.9%, TB profiler: 40.5%, PhyResSE: 40.5%, CASTB: 48.6%, and Mykrobe: 43.2%) was much higher than between phenotypic DST and rapid molecular genotypic DST (18.9%) among the 37 strains. In contrast, the rifampin concordance rate between phenotypic DST and WGS and that between phenotypic DST and rapid molecular genotypic DST was similar (81.1-89.2%). We also found novel mutations associated with INH in katG and ahpC gene region, not covered by the line probe assay. In addition, lineage analysis identified 81.1% of these samples as L2 East Asian lineage strains, and 18.9% as L4 Euro-American lineage strains. CONCLUSION: WGS may play a pivotal role in TB diagnosis and the detection of drug resistance, genetic diversity, and transmission dynamics in the near future because of its accuracy, speed, and extensibility.

Comparison of Factors Associated With Direct Versus Transferred-in Admission to Government-Designated Regional Centers Between Acute Ischemic Stroke and Myocardial Infarction in Korea.

BACKGROUND: There has been no comparison of the determinants of admission route between acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We examined whether factors associated with direct versus transferred-in admission to regional cardiocerebrovascular centers (RCVCs) differed between AIS and AMI. METHODS: Using a nationwide RCVC registry, we identified consecutive patients presenting with AMI and AIS between July 2016 and December 2018. We explored factors associated with direct admission to RCVCs in patients with AIS and AMI and examined whether those associations differed between AIS and AMI, including interaction terms between each factor and disease type in multivariable models. To explore the influence of emergency medical service (EMS) paramedics on hospital selection, stratified analyses according to use of EMS were also performed. RESULTS: Among the 17,897 and 8,927 AIS and AMI patients, 66.6% and 48.2% were directly admitted to RCVCs, respectively. Multivariable analysis showed that previous coronary heart disease, prehospital awareness, higher education level, and EMS use increased the odds of direct admission to RCVCs, but the odds ratio (OR) was different between AIS and AMI (for the first 3 factors, AMI > AIS; for EMS use, AMI < AIS). EMS use was the single most important factor for both AIS and AMI (OR, 4.72 vs. 3.90). Hypertension and hyperlipidemia increased, while living alone decreased the odds of direct admission only in AMI; additionally, age (65-74 years), previous stroke, and presentation during non-working hours increased the odds only in AIS. EMS use weakened the associations between direct admission and most factors in both AIS and AMI. CONCLUSIONS: Various patient factors were differentially associated with direct admission to RCVCs between AIS and AMI. Public education for symptom awareness and use of EMS is essential in optimizing the transportation and hospitalization of patients with AMI and AIS.

Dynamic and Static Switching in ITO/SnOx/ITO and Its Synaptic Application.

The attempts to devise networks that resemble human minds are steadily progressing through the development and diversification of neural networks (NN), such as artificial NN (ANN), convolution NN (CNN), and recurrent NN (RNN). Meanwhile, memory devices applied on the networks are also being studied together, and RRAM is the one of the most promising candidates. The fabricated ITO/SnOX/TaN device showed two forms of current-voltage (I-V) curves, classified as dynamic and static. It was triggered from the forming process, and the difference between the two curves resulted from the data retention measured at room temperature for 103 s. The dynamic curve shows a time-dependent change in the data, and the cause of the data preservation period was considered through X-ray photoelectron spectroscopy (XPS) and linear fitting in conduction mechanisms. To confirm whether the memory performance of the device may be implemented on the synapse, the change in the plasticity was confirmed using a rectangular-shaped pulse. Paired-pulse facilitation (PPF) was implemented, and the change from short-term potentiation (STP) to long-term potentiation (LTP) was achieved.

Variability of urinary creatinine, specific gravity, and osmolality over the course of pregnancy: Implications in exposure assessment among pregnant women.

Due to dilution status of the urine, chemical concentrations measured in spot urine are frequently adjusted using correction factors, such as creatinine, specific gravity (SG), or osmolarity of the urine. Urinary correction factors, however, can be influenced dramatically by physiological changes such as pregnancy. Details about the variation of urine dilution over the course of pregnancy are not well characterized. In the present study, we investigated the variation of urine correction factors over time among the pregnant women of Korea (n = 69) and Thailand (n = 102). Creatinine, SG, and osmolality were determined in the urine samples obtained in each trimester of the participating women, and were compared by sampling time and by nationality. Implication of the variation in these correction factors was studied using phthalate metabolites measured in the urine samples as model chemicals. Urinary correction factors significantly varied across the trimesters especially in Korean pregnant women: urinary creatinine and osmolality were significantly lower in the third trimester (T3) urine than the first trimester (T1) urine. Urinary creatinine and SG of the T3 urine of Korean pregnant women were also significantly lower than those reported from the non-pregnant women who participated in Korean National Environmental Health Survey (KoNEHS) 2015-2017. Among Thai women, however, these correction factors were rather stable across the pregnancy. Differences in ethnicity, or in behavior such as water consumption amount may partly explain the differences. Temporal changes in these urine correction factors influenced the urinary phthalate metabolite concentrations adjusted for dilution, in both Korean and Thai pregnant women. The present observations show that the variations of urinary correction factors should be considered in exposure assessment of urinary chemicals for pregnant women, in order to circumvent potential bias due to physiological changes occurring during pregnancy, and to reduce errors in exposure classification and association.

Positivity of SARS-CoV-2 Antibodies among Korean Healthy Healthcare Workers 1 and 2 Weeks after Second Dose of Pfizer-BioNTech Vaccination.

The antibody titer of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was observed in 289 healthy healthcare workers who had completed the second dose of the Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccine. Antibody tests were performed using both the automated electrochemiluminescence immunoassay (ECLIA) and the chromatographic lateral flow immunoassay (LFIA). All subjects had antibodies against the receptor binding domain of the spike protein of SARS-CoV-2 only one week after completing the vaccination, and the antibody titer became significantly higher after another week (P < 0.001). Since there was a large amount of antibody formation within two weeks after completion of vaccination, the less sensitive method, LFIA, also showed high sensitivity. There was no significant difference between whole blood and serum in detecting SARS-CoV-2 antibodies after vaccination. This is an early study of vaccinations among Koreans and is expected to contribute to the establishment of national guidelines on COVID-19 vaccination.

Evaluation of Three Multiplex Real-time Reverse Transcription PCR Assays for Simultaneous Detection of SARS-CoV-2, Influenza A/B, and Respiratory Syncytial Virus in Nasopharyngeal Swabs.

BACKGROUND: In the coronavirus disease 2019 (COVID-19) pandemic era, the simultaneous detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus (Flu), and respiratory syncytial virus (RSV) is important in the rapid differential diagnosis in patients with respiratory symptoms. Three multiplex real-time reverse transcription polymerase chain reaction (rRT-PCR) assays have been recently developed commercially in Korea: PowerChek™ SARS-CoV-2, Influenza A&B Multiplex Real-time PCR Kit (PowerChek; KogeneBiotech); STANDARD™ M Flu/SARS-CoV-2 Real-time Detection Kit (STANDARD M; SD BioSensor); and Allplex™ SARS-CoV-2/FluA/FluB/RSV Assay (Allplex; Seegene). We evaluated the analytical and clinical performances of these kits. METHODS: A limit of detection tests were performed and cross-reactivity analysis was executed using clinical respiratory samples. Ninety-seven SARS-CoV-2-positive, 201 SARS-CoV-2-negative, 71 influenza A-positive, 50 influenza B-positive, 78 RSV-positive, and 207 other respiratory virus-positive nasopharyngeal swabs were tested using the three assays. The AdvanSure™ respiratory viruses rRT-PCR assay (AdvanSure; LG Life Sciences) was used as a comparator assay for RSV. RESULTS: Except in influenza B, in SARS-CoV-2 and influenza A, there were no significant differences in detecting specific genes of the viruses among the three assays. All three kits did not cross-react with common respiratory viruses. All three kits had greater than 92% positive percent agreement and negative percent agreement and ≥ 0.95 kappa value in the detection of SARS-CoV-2 and flu A/B. Allplex detected RSV more sensitively than AdvanSure. CONCLUSION: The overall performance of three multiplex rRT-PCR assays for the concurrent detection of SARS-CoV-2, influenza A/B, and RSV was comparable. These kits will promote prompt differential diagnosis of COVID-19, influenza, and RSV infection in the COVID-19 pandemic era.

Viral RNA Load in Mildly Symptomatic and Asymptomatic Children with COVID-19, Seoul, South Korea.

Along with positive SARS-CoV-2 RNA in nasopharyngeal swabs, viral RNA was detectable at high concentration for >3 weeks in fecal samples from 12 mildly symptomatic and asymptomatic children with COVID-19 in Seoul, South Korea. Saliva also tested positive during the early phase of infection. If proven infectious, feces and saliva could serve as transmission sources.

Usefulness of the Hematopoietic Stem Cell Donor Pool as a Source of HLA-Homozygous Induced Pluripotent Stem Cells for Haplobanking: Combined Analysis of the Cord Blood Inventory and Bone Marrow Donor Registry.

Induced pluripotent stem cells (iPSCs) have opened up unprecedented opportunities for novel therapeutic options for precision medicine. Hematopoietic stem cell (HSC) donor pools with previously determined HLA types may be ideal sources for iPSC production. Based on the HLA distribution of cryopreserved cord blood units (CBUs) and registered bone marrow (BM) donors, we estimated how much of the Korean population could be covered by HLA-homozygous iPSCs. We analyzed a total of 143,866 Korean HSC donors (27,904 CBUs and 115,962 BM donors). Each donor sample was typed for the HLA-A, -B, and -DRB1 alleles at low to intermediate resolution by DNA-based molecular techniques: PCR sequence-specific oligonucleotide (PCR-SSOP), PCR with sequence-specific primers (PCR-SSP) and PCR with sequence-based typing (PCR-SBT). We also identified individuals possessing homozygous HLA haplotypes by direct counting. The matching probabilities for zero-mismatch transplantation were calculated for 143,866 Koreans and 50 million potential Korean patients. Among the HSC donor pool, 17 HLA-A alleles, 41 HLA-B alleles, and 13 HLA-DRB1 alleles, as well as 128 homozygous HLA-A-B-DRB1 haplotypes, were identified at serologic equivalents, and those haplotypes cumulatively matched 93.20% of the 143,866 Korean donors as zero HLA-mismatch iPSC sources. Among the combinations of 2,056 haplotypes with frequencies ≥ 0.001% in a population of 50 million, those 128 homozygous haplotypes can provide 93.65% coverage for potential Korean recipients. Haplobanking of a reasonable number of HLA-A, -B, and -DRB1 homozygous iPSC lines derived from CBUs and cells of registered BM donors may be an efficient option for allogenic iPSC therapy.

Fifteen new nucleotide substitutions in variants of human papillomavirus 18 in Korea : Korean HPV18 variants and clinical manifestation.

High-risk human papillomavirus (HPV) infection is an essential factor for the development of cervical cancer. HPV18 is the second most common carcinogenic HPV type following HPV16, but the lineages of HPV18 have been less well studied than those of HPV 16. The purpose of this study was to analyze the nucleotide variants in the E6, E7, and L1 genes of HPV18, to assess the prevalence of HPV18 variants in Korea and to explore the relationship between HPV18 genetic variants and the risk for cervical cancer.A total of 170 DNA samples from HPV18-positive cervical specimens were collected from women admitted to a secondary referral hospital located in Seoul. Among them, the lineages of the 97 samples could be successfully determined by historical nomenclature.All the studied HPV 18 variants were lineage A. Sublineages A1 and A4 comprised 91.7% (89/97) and 1.0% (1/97), respectively. Sublineages other than A1 or A4 comprised 7.2% (7/97). We identified 15 new nucleotide substitutions among 44 nucleotide substitutions: C158T, T317G, T443G, A560G, A5467G, A5560C, A5678C, A6155G, G6462A, T6650G, G6701A, T6809C, A6823G, T6941C and T6953C. Among them, 6 substitutions at positions 317, 443, 5467, 5560, 6462, and 6823 resulted in amino acid changes (E6: F71L and N113K; L1: H13R, H44P, A345T, and N465S, respectively). The pathologic results were classified as normal in 25.8% (25/97) of the women, atypical squamous cells of undermined significance (ASCUS) in 7.2% (7/97), cervical intraepithelial neoplasia (CIN) 1 in 36.1% (35/97), CIN2/3 in 19.6% (18/97), and carcinoma in 12.4% (12/97). There was no significant association between the HPV18 sublineages and the severity of pathologic lesion or the disease progression.This study is the first to analyze the distribution of HPV18 variants in Korean and to associate the results with pathologic findings. Although the HPV18 variants had no significant effect on the degree and progression of the disease, the newly discovered nonsynonymous mutation in L1 might serve as a database to determine vaccine efficacy in Korean women.

In Situ-Generated Reactive Oxygen Species in Precharged Titania and Tungsten Trioxide Composite Catalyst Membrane Filters: Application to As(III) Oxidation in the Absence of Irradiation.

This study demonstrates that in situ-generated reactive oxygen species (ROSs) in prephotocharged TiO2 and WO3 (TW) composite particle-embedded inorganic membrane filters oxidize arsenite (As(III)) into arsenate (As(V)) without any auxiliary chemical oxidants under ambient conditions in the dark. TW membrane filters have been charged with UV or simulated sunlight and subsequently transferred to a once-through flow-type system. The charged TW filters can transfer the stored electrons to dissolved O2, producing ROSs that mediate As(III) oxidation in the dark. Dramatic inhibition of As(V) production with O2 removal or addition of ROS quenchers indicates an ROS-mediated As(III) oxidation mechanism. Electron paramagnetic spectroscopic analysis has confirmed the formation of the HO2•/O2•- pair in the dark. The WO3 fraction in the TW filter significantly influences the performance of the As(III) oxidation, while As(V) production is enhanced with increasing charging time and solution pH. The As(III) oxidation is terminated when the singly charged TW filter is fully discharged; however, recharging of TW recovers the catalytic activity for As(III) oxidation. The proposed oxidation process using charged TW membrane filters is practical and environmentally benign for the continuous treatment of As(III)-contaminated water during periods of unavailability of sunlight.

Total nucleated cell counts are driving clinician's choice rather than cryopreservation period: Lesson for cord blood banks.

According to the increase in both the number of cryopreserved cord blood (CB) units and the cryopreservation period for each CB unit in the largest public CB bank in Korea, we are pursuing greater efficiency in CB bank management. Thus, we analyzed whether the cryopreservation period has a negative impact on the selection of CB units for CB transplantation (CBT). Until December 2019, 468 CB units were used for transplantation. The cryopreservation period, total nucleated cell (TNC), and CD34+ cell counts were analyzed among the CB units according to the CBT-year and the donation year. The results showed that the cryopreservation period was increased in recent CBT-year groups. The transplanted CB units showed similar TNC counts irrespective of the donation year, and the mean TNC count was 13.9 × 108/unit. CB units cryopreserved for a relatively long period were transplanted consistently. The mean TNC count of CB units cryopreserved for over 10 years was 16.4 × 108/unit. The mean CD34+ cell counts were not significantly different among the CB units transplanted after CBT-2013 and among the CB units donated after CBT-2011. Through an analysis of the CB units selected by clinicians for CBT, this study revealed that clinicians placed more weight on the TNC counts than on the cryopreservation period of cryopreserved CB units. Therefore, the minimum TNC count of CB units suitable for cryopreservation should be increased up to 13.0 × 108/unit to balance the satisfaction of clinicians' needs with the efficiency of the CB bank.

Performance of Norudia Glycated Albumin Assay on Multiple Analytical Platforms and Comparison to Lucica Assay.

BACKGROUND: The Norudia glycated albumin (GA) assay was evaluated for analytical performance and assay applicability on multiple analytical platforms. METHODS: The evaluation included precision, linearity, reference interval, and comparison with Lucica GA assay. A multicenter study was conducted to compare the results of Norudia GA assay on five kinds of widely used automated clinical chemistry analyzers. RESULTS: Within-laboratory imprecisions for GA% presented 1.3 - 3.3% and 0.8 - 2.6% for low- and high-level control materials, respectively, on different analyzers. GA assay was linear from 20.0 to 680.0 µmol/L of GA. The claimed reference range (12 - 16 GA%) was verified. Norudia GA showed a good GA% correlation with Lucica GA (correlation coefficient 0.999). GA% from each analyzer showed good correlation with the consensus mean of the results of five analyzers (correlation coefficient 0.997 - 0.999). CONCLUSIONS: The Norudia GA assay can successfully be implemented in all the tested platforms, with good GA% correlation.

A Hungatella effluvii isolate in blood culture of a patient with hematochezia.

Hungatella spp. are anaerobic bacteria, are known members of the gut microbiome and very rarely cause human infection. Hungatella effluvii was isolated from an effluent treatment plant in 2014. We report a case of bacteremia due to H. effluvii that occurred after hematochezia in a patient with prostate cancer. It was misidentified by the VITEK 2 system (bioMérieux, France) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and was correctly identified by 16S rRNA gene sequencing.