HLA-DRB1 is associated with cefaclor-induced immediate hypersensitivity.

Background: Drug-induced hypersensitivity such as anaphylaxis is an important cause of drug-related morbidity and mortality. Cefaclor is a leading cause of drug induced type I hypersensitivity in Korea, but little is yet known about genetic biomarkers to predict this hypersensitivity reaction. We aimed to evaluate the possible involvement of genes in cefaclor induced type I hypersensitivity. Methods: Whole exome sequencing (WES) and HLA genotyping were performed in 43 patients with cefaclor induced type I hypersensitivity. In addition, homology modeling was performed to identify the binding forms of cefaclor to HLA site. Results: Anaphylaxis was the most common phenotype of cefaclor hypersensitivity (90.69%). WES results show that rs62242177 and rs62242178 located in LIMD1 region were genome-wide significant at the 5 × 10-8 significance level. Cefaclor induced type I hypersensitivity was significantly associated with HLA-DRB1∗04:03 (OR 4.61 [95% CI 1.51-14.09], P < 0.002) and HLA-DRB1∗14:54 (OR 3.86 [95% CI 1.09-13.67], P < 0.002). Conclusion: LIMD1, HLA-DRB1∗04:03 and HLA-DRB1∗14:54 may affect susceptibility to cefaclor induced type I hypersensitivity. Further confirmative studies with a larger patient population should be performed to ascertain the role of HLA-DRB1 and LIMD1 in the development of cefaclor induced hypersensitivity.

A comprehensive analysis integrating phenotypic assessment uncovering thornless cultivar lineages in Aralia elata.

Aralia elata is an Araliaceae woody plant species found in Northeastern Asia. To understand how genetic pools are distributed for A.elata clones, we were to analyze the population structure of A.elata cultivars and identify how these are correlated with thorn-related phenotype which determines the utility of A.elata. We found that the de novo assembled genome of 'Yeongchun' shared major genomic compartments with the public A.elata genome assembled from the wild-type from China. To identify the population structure of the 32 Korean and Japanese cultivars, we identified 44 SSR markers and revealed three main sub-clusters using ΔK analysis with one isolated cultivar. Machine-learning based clustering with thorn-related phenotype correlated moderately with population structure based on SSR analysis suggested multi-layered genetic regulation of thorn-related phenotypes. Thus, we revealed genetic lineage of A.elata and uncovered isolated cultivar which can provide new genetic material for further breeding.

Simple and robust LC-MS/MS method for quantification of colistin methanesulfonate and colistin in human plasma for therapeutic drug monitoring.

A rapid, simple, and robust LC-MS/MS method was developed and validated for the quantitation of colistin and colistin methanesulfonate (CMS) in human plasma. The method also prevented overestimation of colistin concentration by establishing the stability of CMS under sample preparation conditions, including blood and plasma storage conditions. Polymyxin B1 was used as an internal standard, and positive-ion electrospray ionization in multiple reaction monitoring mode was used for quantification. Chromatographic separation was achieved using a Zorbax eclipse C18 column (3.5 µm, 2.1 mm i.d. × 100 mm), with a flow rate of 0.5 mL/min, 5 µL injection volume, and gradient elution with a mixture of acetonitrile-water (containing 0.1 % trifluoroacetic acid). The method had a quantifiable range of 0.043-8.61 and 0.057-11.39 µg/mL for colistin A and B in human plasma, respectively, under a total runtime of 6.0 min. Further, it demonstrated appropriate extraction efficiency, no significant interference from co-eluting endogenous compounds, and satisfactory intraday and interday precision and accuracy. The proposed procedure for sample preparation successfully addressed the issue of CMS instability, consequently diminishing the probability of overestimating the concentration of colistin. Therefore, this simple and robust LC-MS/MS method for CMS and colistin quantification in human plasma is a valuable tool for clinicians to accurately monitor colistin treatment in patients with infections caused by multidrug-resistant (MDR) Gram-negative bacteria.

Clinical aspects of severe cutaneous adverse reactions caused by beta-lactam antibiotics: A study from the Korea SCAR registry.

Background: Although beta-lactams are 1 of the major causative agents of severe cutaneous adverse reactions (SCAR), their epidemiology and clinical aspects have been poorly studied. This study aimed to investigate the characteristics of SCAR caused by beta-lactams in the Korean SCAR registry. Methods: We retrospectively analyzed beta-lactam-induced SCAR cases collected from 28 tertiary university hospitals in Korea between 2010 and 2015. The SCAR phenotypes included Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), SJS-TEN overlap, and drug reaction with eosinophilia and systemic symptoms (DRESS). Beta-lactams were classified according to their chemical structures: penicillins, cephalosporins, and carbapenems. The causative beta-lactams, clinical and laboratory features, treatments, and outcomes were evaluated. Results: Among the 275 antibiotic-induced SCAR cases, 170 patients developed SCAR induced by beta-lactams. Beta-lactam antibiotic-induced SCAR showed more frequent SJS/TEN compared to SCAR induced by non-beta-lactam antibiotics (SJS/TEN/SJS-TEN overlap/DRESS: 36.5/11.2/5.9/46.5% vs. 23.8/10.5/2.9/62.9%, P = 0.049). Cephalosporin was the most common culprit drug. Particularly, 91 and 79 patients presented with SJS/TEN and DRESS, respectively. The odds ratio (OR) for poor prognosis, such as sequelae and death, was significantly increased in subjects with SJS-TEN overlap and TEN and carbapenem as culprit drug in the multivariate analysis (OR, 35.61; P = 0.016, OR, 28.07; P = 0.006, OR 30.46; P = 0.027). Conclusion: Among antibiotic-induced SCAR, clinical features were different depending on whether the culprit drug was a beta-lactam antibiotic or SCAR type. The poor prognosis was related to SJS-TEN overlap, TEN type, and carbapenem as the culprit drug.

Successful mRNA COVID-19 Vaccination and Colonoscopy After Oral Desensitization in a Patient With Polyethylene Glycol Allergy.

Anaphylaxis to polyethylene glycol (PEG) is rare and mainly occurs with the use of laxatives containing PEG. Recently, an increasing number of PEG allergies have been reported, particularly those related to coronavirus disease 2019 (COVID-19) vaccines. mRNA COVID-19 vaccines, such as the BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines, contain PEG2000 as an excipient and are contraindicated when allergy to a vaccine component exist. We report a 55-year-old woman's history as a case of successful mRNA COVID-19 vaccination and colonoscopy after oral desensitization to PEG in a patient with PEG allergy who required both COVID-19 vaccination and colon evaluation. Allergy to PEG was diagnosed based on clinical history, skin test results, and basophil histamine release testing. Oral desensitization effectively suppressed histamine release from basophils in response to PEG stimulation, suggesting that oral desensitization using PEG-based laxatives may be an effective treatment option for patients with allergy to the substance.

Identification of a candidate gene responsible for the G locus determining chartreuse bulb color in onion (Allium cepa L.) using bulked segregant RNA-Seq.

KEY MESSAGE: A gene encoding a laccase responsible for chartreuse onion bulb color was identified. Markers tagging this gene showed perfect linkage with bulb colors among diverse germplasm. To identify a casual gene for the G locus determining chartreuse bulb color in onion (Allium cepa L.), bulked segregant RNA-Seq (BSR-Seq) was performed using yellow and chartreuse individuals of a segregating population. Through single nucleotide polymorphism (SNP) and differentially expressed gene (DEG) screening processes, 163 and 143 transcripts were selected, respectively. One transcript encoding a laccase-like protein was commonly identified from SNP and DEG screening. This transcript contained four highly conserved copper-binding domains known to be signature sequences of laccases. This gene was designated AcLAC12 since it showed high homology with Arabidopsis AtLAC12. A 4-bp deletion creating a premature stop codon was identified in exon 5 of the chartreuse allele. Another mutant allele in which an intact LTR-retrotransposon was transposed in exon 5 was identified from other chartreuse breeding lines. Genotypes of molecular markers tagging AcLAC12 were perfectly matched with bulb color phenotypes in segregating populations and diverse breeding lines. All chartreuse breeding lines contained inactive alleles of DFR-A gene determining red bulb color, indicating that chartreuse color appeared when both DFR-A and AcLAC12 genes were inactivated. Linkage maps showed that AcLAC12 was positioned at the end of chromosome 7. Transcription levels of structural genes encoding enzymes in anthocyanin biosynthesis pathway were generally reduced in chartreuse bulk compared with yellow bulk. Concentrations of total quercetins were also reduced in chartreuse onion. However, significant amounts of quercetins were detected in chartreuse onion, implying that AcLAC12 might be involved in modification of quercetin derivatives in onion.

The Effect of Fe Addition on Microstructure, Mechanical Properties and Electric Conductivity of the As-Cast Al-Mg-Si Alloys.

Fe is considered as one of the most harmful trace elements among impurities in aluminum and its alloys due to its influence of the mechanical properties especially in elongation. It is therefore essential that the Fe content is controlled to improve quality and the toughness of aluminum alloy castings. Since demand for high strength aluminum alloy casting was significantly increased in electro materials and devices, automotive and airplane industries, it is necessary to characterize the effect of Fe and set the tolerable amount of Fe content in aluminum alloys. Al6061 alloys were prepared with compositions of 0.36, 0.45, 0.58, 0.65, 0.75, 0.81 and 0.91 wt.% Fe. Solidification characteristics were analyzed by CALPHAD (Pandat software) method. Mechanical properties such as hardness, tensile strength, elongation and fatigue strength were evaluated and compared with different Fe contents. Al13Fe4 phase increased with increasing as Fe content, however, other phases, α-AlFeSi and Mg2Si, showder a slight decrease. The higher the Fe content, the lower the electrical conductivity of the alloy due to the severe distortion of the Al matrix. As Fe content was more than specification of Al6061 alloy, 0.7 wt.%, the mechanical properties, especially, hardness and elongation were greatly influenced. The hardness is attributed to the poor densification and angular-shaped Al13Fe4 phases unevenly distributed in the α-Al matrix.

A Nationwide Study of Severe Cutaneous Adverse Reactions Based on the Multicenter Registry in Korea.

BACKGROUND: Because severe cutaneous adverse reactions (SCARs), such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS) rarely occur, clinical data based on large-scale studies are still lacking. OBJECTIVE: To provide information on culprit drugs and clinical characteristics, including morbidity and mortality of SCARs based on a nationwide registry. METHODS: SCAR cases that occurred from 2010 to 2015 were recruited to the Korean SCAR registry from 34 tertiary referral hospitals. Demographics, causative drugs, causality, and clinical outcomes were collected by reviewing the medical record. RESULTS: A total of 745 SCAR cases (384 SJS/TEN cases and 361 DRESS cases) due to 149 drugs were registered. The main causative drugs were allopurinol (14.0%), carbamazepine (9.5%), vancomycin (4.7%), and antituberculous agents (6.3%). A strong preference for SJS/TEN was observed in carbonic anhydrase inhibitors (100%), nonsteroidal anti-inflammatory drugs (84%), and acetaminophen (83%), whereas dapsone (100%), antituberculous agents (81%), and glycopeptide antibacterials (78%) were more likely to cause DRESS. The mortality rate was 6.6% (SJS/TEN 8.9% and DRESS 4.2%). The median time to death was 19 days and 29 days in SJS/TEN and DRESS respectively, and 89.8% of deaths occurred within 60 days after the onset of the skin symptoms. CONCLUSION: Allopurinol, carbamazepine, vancomycin, and antituberculous agents were the leading causes of SCARs in Korea. Some drugs preferentially caused a specific phenotype. The mortality rate of SCARs was 6.6%, and most of the deaths occurred within 2 months.

High-Quality Genome Assembly of Peronospora destructor, the Causal Agent of Onion Downy Mildew.

Peronospora destructor is an obligate biotrophic oomycete that causes downy mildew on onion (Allium cepa). Onion is an important crop worldwide, but its production is affected by this pathogen. We sequenced the genome of P. destructor using the PacBio sequencing platform, and de novo assembly resulted in 74 contigs with a total contig size of 29.3 Mb and 48.48% GC content. Here, we report the first high-quality genome sequence of P. destructor and its comparison with the genome assemblies of other oomycetes. The genome is a very useful resource to serve as a reference for analysis of P. destructor isolates and for comparative genomic studies of the biotrophic oomycetes.

Reliability of Processing Map and Influence of Sigma Phase Precipitation on Hot Workability of Duplex Stainless Steel.

The hot deformation characteristics of an UNS No. S32205 grade duplex stainless steel with nitrogen content of 0.17 ms% was studied over the ranges of temperature from 800 to 1200 °C and strain rates from 0.001 to 1.0 s-1 at the total strain of 0.5 by the hot compression test to draw the processing map. The obtained map was discussed in combinations of microstructural observations and TEM analysis. The optimum hot working region is the temperatures from 950 to 1200 °C regardless of the strain rates without cracks and sigma precipitates.

Unique Clinical Characteristics and Prognosis of Allopurinol-Induced Severe Cutaneous Adverse Reactions.

BACKGROUND: Allopurinol is the most common cause of severe cutaneous adverse reactions (SCARs) in Korea due to the relatively high prevalence of the HLA-B*58:01 genotype (8%-13%). OBJECTIVE: We aimed to reveal the clinical characteristics and risk factors for death in allopurinol-induced SCARs in Korea. METHODS: We retrospectively reviewed the medical records of 106 subjects with allopurinol-induced SCARs and 639 subjects with other drug-induced SCARs who were enrolled in the Korean SCARs Registry (collected from 34 nationwide medical institutions) from January 2010 to December 2015. RESULTS: Subjects with allopurinol-induced Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) were older and had more comorbidities, longer latent periods, longer disease durations, more deranged laboratory findings, and increased disease severity resulting in a higher mortality rate (17.6% vs 7.6%; P = .020) compared with the subjects with other drug-induced SCARs. There was no significant difference in age or mortality in drug reaction with eosinophilia and systemic symptoms (DRESS). Subjects with allopurinol-induced SJS/TEN were older and had shorter latent periods and a higher mortality rate (17.6% vs 3.7%; P = .044) than those with allopurinol-induced DRESS. In allopurinol-induced SJS/TEN, significant risk factors for death included chronic renal insufficiency, intensive care unit (ICU) admission, increased blood urea nitrogen levels on admission day, serum peak eosinophil counts, baseline and peak creatinine levels, baseline and peak alanine aminotransferase levels, and decreased lowest platelet counts. In allopurinol-induced DRESS, significant risk factors for death included ICU admission and increased glucose levels on admission day. CONCLUSIONS: Allopurinol-induced SCARs have unique characteristics and poor prognoses with important predictive factors of death.

Development and validation of a highly sensitive LC-MS/MS method for in vitro measurement of histamine concentration.

The basophil histamine release test (HRT) is an important in vitro diagnostic assay to evaluate immunoglobin E (IgE)-mediated allergic responses. In this study, a bioanalytical LC-MS/MS method was developed and validated to quantify histamine in the leukocyte suspension from human peripheral blood. The method used pre-column derivatization with phenylisothiocyanate (PITC) and the resulting phenylthiocarbamyl (PTC) histamine was analyzed by positive-ion electrospray ionization using the multiple reaction monitoring mode. Chromatographic separation was achieved using an Imtakt-HT C18 column (2.1 mm × 50 mm, 3.0 µm), with a flow rate of 0.35 mL/min, 2 µL injection, and gradient elution with a mixture of acetonitrile-2 mM ammonium acetate buffer (both containing 0.1% formic acid). The total runtime of the method was 3.0 min including equilibration time. The method had a lower limit of detection of 0.1 ng/mL, and the quantifiable range was 0.1-100 ng/mL in the leukocyte suspension. The intra-day and inter-day precision and accuracy results were within the acceptable limits. It was established that histamine quantification should be performed within 2 h of preparing the leukocyte suspension, and freezing and thawing should be avoided. This method was successfully applied to the diagnosis and evaluation of the pathophysiologic mechanism of respiratory or cutaneous allergic diseases.

Whole-Genome Sequence of Erwinia persicina B64, Which Causes Pink Soft Rot in Onions.

Erwinia persicina B64 was isolated from rotten onions in cold-storage facilities. Here, we report the complete genome sequence of E. persicina B64, which contains 5,070,450 bp with 55.17% GC content. The genome of this isolate is composed of one chromosome and two plasmids.

Bullous pemphigoid associated with chronic hepatitis C virus infection in a hepatitis B virus endemic area: A case report.

INTRODUCTION: Bullous pemphigoid is a type of acute or chronic autoimmune disease that involves subepidermal skin lesions with bulla formation. Although viral infections, such as, human herpes virus (HHV), human immunodeficiency virus, cytomegalovirus, Epstein-Barr virus, HHV-6, hepatitis B virus (HBV), and hepatitis C virus (HCV), are known factors of bullous pemphigoid, HCV infection has only been rarely associated factor, especially in HBV endemic area. A 78-year-old man was admitted to our hospital due to erythematous bulla of onset 3 months before presentation affecting his entire body. Pathologic findings, that is, subepidermal bullae containing eosinophils and neutrophils with superficial perivascular lymphocytic and eosinophilic infiltration, were consistent with bullous pemphigoid. Anti-HCV was positive and HCV quantitative real-time polymerase chain reaction (PCR) was 1.25 x 10 IU/mL. HCV genotype was 2a. After a diagnosis of bullous pemphigoid associated with chronic HCV infection was reached, he was treated with oral methylprednisolone for bullous pemphigoid, and his skin lesions improved. Oral direct-acting antiviral agents (sofosbuvir plus ribavirin) were prescribed for chronic hepatitis C, and sustained viral response was achieved. CONCLUSION: The authors report a rare case of bullous pemphigoid associated with chronic HCV infection in a HBV endemic area and advise that HCV should be considered in the differential diagnosis of factors precipitating bullous pemphigoid, even in HBV endemic areas.

Transcriptional profiling of PBMCs unravels B cell mediated immunopathogenic imprints of HCV vasculitis.

B cell depletion therapy using rituximab has been shown to be effective in achieving remission in patients with HCV-mixed cryoglobulinemic (MC) vasculitis. Previously, we have demonstrated abnormalities in peripheral immune cells involving neutrophils, chemotaxis, and innate immune activation among patients with HCV-MC vasculitis when compared to HCV patients without vasculitis. In this study, we evaluated the effect of B cell depletion therapy on transcriptional profiles of peripheral blood mononuclear cells before and after riruximab therapy, in order to unravel the pathogenic mechanism involved in HCV-MC vasculitis induced by abnormal B cell proliferation. DNA microarray analysis was performed using RNA from PBMCs from seven patients with HCV-MC vasculitis and seven normal volunteers. DNA was hybridized to Affymetrix U133A chips. After normalization, differentially expressed gene list with treatment was generated using partitional clustering. RT-PCR, flow cytometry, and enzyme immunoassay (EIA) was used to validate DNA microarray findings. Differentially expressed genes included B cells and non-B cell genes. Validation of genes using purified cell subsets demonstrated distinct effect of B cell depletion therapy on non-B cells, such as monocytes, T cells, and NK cells. Notably, B lymphocyte stimulator (BLyS) levels were persistently elevated in patients who subsequently relapsed. In conclusion, pathogenesis of HCV-MC vasculitis is mediated by abnormal proliferation of B cells, driven by BLyS, leading to significant effects on non-B cells in mediating symptomatology. Future therapeutics using a combination approach of B cell depletion and proliferation may be desired to achieve long-term remission.

Ionic-surfactant-coated subtilisin: activity, enantioselectivity, and application to dynamic kinetic resolution of secondary alcohols.

In this work, we explored the utility of ionic-surfactant-coated Bacillus licheniformis subtilisin (ISCBLS) as the catalyst for the dynamic kinetic resolution of secondary alcohols. ISCBLS was prepared by freeze-drying Bacillus licheniformis subtilisin with both ionic surfactant 1 and dextrin. ISCBCL displayed 9300-fold enhanced activity relative to its native counterpart in the transesterificaion of N-acetyl phenylalanine ethyl ester with 1-propanol in hexane and 12 800-fold enhanced activity in the transesterification of trifluoroethyl butyrate with 1-phenylethanol in THF. The enantioselectivity of ISCBLS was examined with 50 secondary alcohols as the substrates for kinetic resolution in the presence of trifluoroethyl butyrate. ISCBLS displayed synthetically useful enantioselectivity for most of the secondary alcohols tested. The enantioselectivity of ISCBLS was in particular good to high for m- or p-substituted 1-phenylethanols. The DKRs of these secondary alcohols by the combination of ISCBLS and a ruthenium-based racemization catalyst provided the products of (S)-configuration with good results (80-94% yield, 90-99% ee). It is concluded that ISCBLS is of great use as the enantiocomplementary counterpart of (R)-selective lipase for the dynamic kinetic resolution of secondary alcohols.

Korean version of the Cough Symptom Score: clinical utility and validity for chronic cough.

BACKGROUND/AIMS: The Cough Symptom Score (CSS) is a simple, useful tool for measuring cough severity. However, there is no standard Korean version of the CSS. We developed a Korean version of the CSS and evaluated its clinical utility and validity for assessing chronic cough severity. METHODS: The CSS was adapted for Korean use following a forward-backward translation procedure. Patients with chronic cough enrolled from five university hospitals were graded using the CSS and a 100-mm linear visual analog scale (VAS) of cough severity at each visit. Patients completed the Leicester Cough Questionnaire (LCQ) upon presentation and completed the LCQ and Global Rating of Change at follow-up visits after 2 to 4 weeks. The concurrent validity, repeatability, and responsiveness of the Korean version of the CSS were determined. RESULTS: Correlation coefficients between the CSS and LCQ, and between the CSS and VAS, were -0.66 and 0.52, respectively. There was a weak correlation between the scores for night and day symptoms (r = 0.24, p = 0.0006). The repeatability of the CSS in patients with no change in cough (n = 23) was high (intra-class correlation coefficient, 0.75; 95% confidence interval [CI], 0.51 to 0.88). Patients who reported an improvement in cough (n = 30) at follow-up visits had a significant improvement in the CSS (median, -2; 95% CI, -3 to -1; p = 0.0003). CONCLUSIONS: The Korean version of the CSS correlated well with other tools for accessing cough severity in chronic cough patients. Therefore, it could be a reliable method for measuring chronic cough severity.

Validated UPLC-MS/MS method for the determination of tadalafil in human plasma and its application to a pharmacokinetic study.

A simple, rapid, and reliable UPLC-MS/MS method was developed and validated for the determination of tadalafil in human plasma. The plasma samples were deproteinized with acetonitrile. Chromatographic separation was performed on a Shiseido C18 (100 × 2.1 mm, 2.7 µm) column with isocratic elution using 2.0 mM ammonium acetate and acetonitrile (55:45, v/v) with 0.1% formic acid at a flow rate of 0.7 mL/min. The total run time was 1 min per sample. The quantitative analysis was performed using multiple reaction monitoring at transition of m/z 390.4 → 268.3 for tadalafil and m/z 475.3 → 283.3 for sildenafil as an internal standard. The method was fully validated over a concentration range of 5-1,000 ng/mL with a lower quantification limit of 5 ng/mL. Intra- and inter-day precision (relative standard deviation, %RSD) were within 8.4% and accuracy (relative error, %RE) was lower than -3.2%. The developed and validated method was successfully applied to a pharmacokinetic study of tadalafil (20 mg) in Korean healthy male subjects (n = 12).

Hepatic hydrothorax without ascites as the first sign of liver cirrhosis.

A 60-year-old woman without a history of liver diseases, but with a history of regular alcohol consumption, presented with a right-sided transudative pleural effusion. Neither parenchymal lung lesion nor pleural thickening was seen on a chest computed tomography. On abdominal ultrasonography, the liver size and contour were normal, and ascites was not noted. Despite performing imaging and laboratory studies, we could not find a cause of the pleural effusion. Thus, due to her history of regular alcohol consumption, we decided to measure liver stiffness using a transient elastography (Fibroscan(®), Echosens(TM), Paris, France), which showed a value of 35.3 kPa suggestive of liver cirrhosis. An intraperitoneal injection of a radioisotope demonstrated the transdiaphragmatic flow of fluid from peritoneal cavity to pleural cavity. The diagnosis was confirmed as hepatic hydrothorax. Management consisting of restricted salt and water intake with diuretics resulted in resolution of the hepatic hydrothorax.