Identification of the novel HLA-B*13:191 allele by next-generation sequencing.

The novel HLA-B*13:191 allele was detected during the HLA typing for kidney transplantation.

Identification of the novel HLA-C*14:159 allele by next-generation sequencing.

The novel HLA-C*14:159 allele was detected during the routine HLA typing for kidney transplantation.

Enhancing the Reliability of PMP22 Copy Number Variation Detection with an Inherited Peripheral Neuropathy Panel.

The utility of the next-generation sequencing (NGS) panel could be increased in hereditary peripheral neuropathies, given that the duplication of PMP22 is a major abnormality. In the present study, the analytical performance of an algorithm for detecting PMP22 copy number variation (CNV) from the NGS panel data was evaluated. The NGS panel covers 141 genes, including PMP22 and five genes within 1.5-megabase duplicated region at 17p11.2. CNV calling was performed using a laboratory-developed algorithm. Among the 92 cases subjected to targeted NGS panel from March 2018 to January 2021, 26 were suggestive of PMP22 CNV. Multiplex ligation-dependent probe amplification analysis was performed in 58 cases, and the results were 100% concordant with the NGS data (23 duplications, 2 deletions, and 33 negatives). Analytical performance of the pipeline was further validated by another blind data set, including 14 positive and 20 negative samples. Reliable detection of PMP22 CNV was possible by analyzing not only PMP22 but also the adjacent genes within the 1.5-megabase region of 17p11.2. On the basis of the high accuracy of CNV calling for PMP22, the testing strategy for diagnosis of peripheral polyneuropathies could be simplified by reducing the need for multiplex ligation-dependent probe amplification.

Quarter-Annulus Si-Photodetector with Equal Inner and Outer Radii of Curvature for Reflective Photoplethysmography Sensors.

Reflection-type photoplethysmography (PPG) pulse sensors used in wearable smart watches, true wireless stereo, etc., have been recently considered a key component for monitoring biological signals such as heart rate, SPO3, and blood pressure. Typically, the optical front end (OFE) of these PPG sensors is heterogeneously configured and packaged with light sources and receiver chips. In this paper, a novel quarter-annulus photodetector (NQAPD) with identical inner and outer radii of curvature has been developed using a plasma dicing process to realize a ring-type OFE receiver, which maximizes manufacturing efficiency and increases the detector collection area by 36.7% compared to the rectangular PD. The fabricated NQAPD exhibits a high quantum efficiency of over 90% in the wavelength of 500 nm to 740 nm and the highest quantum efficiency of 95% with a responsivity of 0.41 A/W at the wavelength of 530 nm. Also, the NQAPD is shown to increase the SNR of the PPG signal by 5 to 7.6 dB compared to the eight rectangular PDs. Thus, reflective PPG sensors constructed with NQAPD can be applied to various wearable devices requiring low power consumption, high performance, and cost-effectiveness.

Characterization of novel HLA-A*24:608N allele discovered in Koreans.

A novel null HLA-A*24 allele, HLA-A*24:608N, was identified in five Korean subjects including three from a family and two separate individuals. This study was performed to discern its immunological function in transplantation settings. Because this null variant had deletions of approximately 12 k base pairs from intron 3 to 3' end of the HLA-A gene, low resolution HLA typing and amplicon-based next generation sequencing (NGS) typing methods had failed to assign it. Hybrid capture-based NGS method confirmed that this novel variant had a large deletion. T-lymphocyte crossmatching by complement-dependent lymphocytotoxicity and flow cytometry with a serum consisting anti-HLA-A24 antibody revealed negative results, implying that an individual with this allele would not carry a functioning A24 antigen. These findings highlight the importance of identifying a null HLA allele by employing appropriate molecular method and providing expected crossmatching outcomes in a real-world transplantation setting.

Identification of the novel HLA-DQA1*01:138 allele by next-generation sequencing.

HLA-DQA1*01:138 is identical to HLA-DQA1*01:03 except for a single nucleotide substitution in exon 3.

Experience of reassessing FBN1 variants of uncertain significance by gene-specific guidelines.

BACKGROUND: Despite the 2015 American College of Medical Genetics and Genomics (ACMG) and Association of Molecular Pathology (AMP) guideline, many variants of FBN1 gene remain inconclusive. In line with publication of the FBN1-specific variant interpretation guideline by ClinGen in 2022, we reassessed variants of uncertain significance (VUS) in FBN1 gene found in our institution. METHODS: VUS found in the course of FBN1 sequencing between December 2015 and April 2022 were reassessed based on FBN1-specific variant interpretation guideline, review of updated literatures and additional genetic tests including family study and/or RNA study if available. RESULTS: Out of 695 patients who underwent FBN1 sequencing, 61 VUS were found in 69 patients. Among them, 38 VUS in 43 patients (62.3%) were reclassified as pathogenic and likely pathogenic variant ((L)PV), including 20 novel (L)PV. Major causes of reclassification were: (1) gene-specific modification of ACMG/AMP criteria, (2) updated literatures and (3) additional genetic tests. The most important evidence for reclassification was clarification of critical amino acid residues. CONCLUSIONS: After reassessing FBN1 variants according to FBN1-specific guideline and up-to-date database, a significant number of VUS was reclassified. Clinical laboratories are encouraged to perform variant reassessment at regular intervals or when there is a major change in the principle of variant interpretation.

Flake formation and composition in soda-lime-silica and borosilicate glasses.

Glass is a food contact material that has been used for a long time in food packaging because it is chemically durable and stable. However, when used for a long time in an aqueous solution or under certain conditions in which alteration may occur, solid flakes may be formed. The phenomenon could be observed when the process of boiling water in a glass kettle is repeated. Transparent and shiny needle-shaped glass fragments appear floating in the water, which may cause complaints from consumers. The purpose of this study is to investigate the conditions leading to the formation of flakes and to identify the components of the suspended flakes in glass container. In this study we investigated the formation of flakes at different temperatures (70-100 °C), initial pH values (3-11) and varying the solution composition (with Na+, K+, Ca2+, Mg2+ concentrations from 0.2 to 40 mg/L). Two types of glass materials, soda-lime-silica glass and borosilicate glass (heat-resistance glass) were examined. Results show that flakes were observed under the following conditions: 24 h at more than 90 °C, pH 8, and 20 mg/L Ca2+ for soda-lime-silica glass and more than 100 °C, pH 11 for borosilicate glass. The component of flakes was identified as a mixture of hydrates of magnesium, calcium, and aluminum silicate analyzed by X-ray fluorescence spectroscopy, inductively coupled plasma-optical emission spectroscopy, and X-ray diffraction.

Simultaneous determination of dehydroacetic acid, benzoic acid, sorbic acid, methylparaben and ethylparaben in foods by high-performance liquid chromatography.

In this study, an analytical method was established and validated to determine the preservatives such as dehydroacetic acid, benzoic acid, sorbic acid, methylparaben and ethylparaben. The level of preservatives was measured by solvent extraction method adding purification process with carrez reagent and by high-performance liquid chromatography (HPLC). The developed analytical method was successfully applied to determine the concentration of preservatives in various food samples including jam, cheese and soy sauce, displaying high accuracy (recoveries between 87.8% and 110%) and precision (%RSD less than 5.92% and 7.72% for intra-day and inter-day, respectively). To verify the applicability of the improved test method, selected 13 food items and collected 521 samples were monitored. As a result, all the cases met the Korea standard guidelines. Consequently, this study is expected to contribute to the safety management of preservatives for domestic distribution and imported food.

Enhanced Photoresponse of High Crystalline Bi2Se3 Thin-Films Using Patterned Substrates.

High-quality Bi2Se3 thin films with topological insulating properties at room temperature have recently attracted much attention as one of the promising materials for realizing innovative electronic and optoelectronic devices. Here, we report the high crystallinity growth of Bi2Se3 thin films on a patterned sapphire substrate (PSS) by using a vapor-phase transport deposition with minimizing thermal dissociation of Se atoms vaporized in Bi2Se3 powder. This PSS not only reduces the large dislocation of heterogeneously grown Bi2Se3 on a sapphire substrate but also induces enhanced light absorption in the visible to near-infrared (IR) ranges compared to Bi2Se3 on planar sapphire substrates. Thus, the Bi2Se3 thin film laterally grown on the PSS reveals uniform surface properties and high crystallinity in the rhombohedral lattice phase with a full width at half maximum of 0.06° for the XRD (003) peak. Also, the photoresponse of the fabricated IR conversion device using Bi2Se3/PSS heterostructure exhibits excellent performance and high reliability with no degradation after continuous switching. As a result, the device constructed with the Bi2Se3/PSS exhibits one order of magnitude higher NIR induced-photocurrent and 1-2 orders of magnitude faster photo-switching than that with Bi2Se3/Al2O3. Such an enhancement in the device performance of Bi2Se3/PSS is confirmed by the increased absorption spectra in visible and NIR ranges and the improved light absorption distribution.

Reducing Microbial Contamination in Hematopoietic Stem Cell Products and Quality Improvement Strategy: Retrospective Analysis of 1996-2021 Data.

Background: Sterility and safety assurance of hematopoietic stem cell (HSC) products is critical in transplantation. Microbial contamination can lead to product disposal and increases the risk of unsuccessful clinical outcomes. Therefore, it is important to implement and maintain good practice guidelines and regulations for the HSC collection and processing unit in each hospital. We aimed to share our experiences and suggest strategies to improve the quality assurance of HSC processing. Methods: We retrospectively analyzed microbial culture results of 11,743 HSC products processed over a 25-year period (January 1996 to May 2021). Because of reorganization of the HSC management system in 2008, the 25-year period was divided into periods 1 (January 1996 to December 2007) and 2 (January 2008 to May 2021). We reviewed all culture results of the HSC products and stored aliquot samples and collected culture results for peripheral blood and catheter samples. Results: Of the 11,743 products in total, 35 (0.3%) were contaminated by microorganisms, including 19 (0.5%) of 3,861 products during period 1 and 16 (0.2%) of 7,882 products during period 2. Penicillium was the most commonly identified microorganism (15.8%) during period 1 and coagulase-negative Staphylococcus was the most commonly identified (31.3%) during period 2. HSC product contamination occurred most often during HSC collection and processing. Conclusions: The contamination rate decreased significantly during period 2, when the HSC management system was reorganized. Our results imply that handling HSC products by trained personnel and adopting established protocols, including quality assurance programs, aid in decreasing the contamination risk.

Development and validation of an ionic chromatography method for nitrite determination in processed foods and estimation of daily nitrite intake in Korea.

A simple ionic chromatography method for nitrite analysis in processed food products was developed and validated. Nitrite in the sample was extracted using 80 °C distilled deionized water and centrifuged. Purification of nitrite from sample solution was performed using OnGuard II Ag, OnGuard II RP and OnGuard II Na cartridge connected in order. Determination of nitrite was carried out using IonPac AG9-HC (4 × 50 mm) and IonPac AS9-HC (4 × 250 mm) columns and a 9 mM sodium carbonate mobile phase. The validated results showed good linearity (r2 > 0.999), recoveries (83.7-107.6%) and precision (1.3-5.1%). The levels of nitrite in processed food products were between n.d. to 33.5 mg/kg, and nitrite was detected in ham, sausage and bacon products. The mean nitrite intake was 2.7% of the Acceptable Daily Intake (ADI, 0.07 mg/kg bw/day) for the Korean population. The method was suitable for the analysis of nitrite in processed foods.

Necessity of multiplex ligation probe amplification in genetic tests: Germline variant analysis of the APC gene in familial adenomatous polyposis patients.

BACKGROUND: Familial adenomatous polyposis (FAP) is an autosomal dominant hereditary cancer syndrome characterized by hundreds to thousands of colorectal adenomatous polyps. Without treatment, progression to colorectal cancer is inevitable. Most pathogenic mutations in the APC gene were nonsense or frameshift mutations; however, some previous studies reported large deletions or duplications. METHOD: We reviewed the results of APC gene analyses from January 2010 to December 2020. We analyzed the entire coding sequence of the APC gene by Sanger sequencing to detect genetic abnormalities. Moreover, multiplex ligation-dependent probe amplification (MLPA) testing was performed starting in September 2017, and a multigene panel study that includes the APC gene was begun in July 2019. RESULTS: In the 266 collected cases, pathogenic variants/likely pathogenic variants (PV/LPVs) in the APC gene were detected in 73 patients, and variants of uncertain significance were found in 13 patients. Among those variants, 14 variants were novel. We performed MLPA for 29 patients, and 7 of them (24.1%) were positive for a large duplication/deletion. Among the 73 cases in the multigene panel study, 17 cases (23.3%) of APC gene variation were detected. CONCLUSION: We retrospectively analyzed the APC gene in Korean patients suspected to have FAP. Variants truncated by nonsense and frame shift mutations were common PV/LPVs. However, the detection rate in the MLPA study was higher than in previous studies of Caucasian populations. We suggest that MLPA should be performed for patients likely to have FAP but in whom no variant is detected by sequencing methods.

Improved spectrophotometric method for nitrite determination in processed foods and dietary exposure assessment for Korean children and adolescents.

A spectrophotometric method based on diazo-coupling reaction for nitrite analysis was established and validated, including inter-laboratory validation, linearity, accuracy, precision, the limit of detection (LOD) and limit of quantification (LOQ). The time-saving and high-recovery method was established by examining the filtration step, colorimetric process and concentration range of the calibration curve. This method showed good linearity (r2 > 0.999) in the range of 0.025-1.0 µg/mL. The three-level recoveries were between 86.7% and 108.6%, with the coefficient of variation (CV) below 5.8%. Mean nitrite concentration ranges in processed foods were ND-33.47 mg/kg. The mean nitrite intake was 0.8% of the Acceptable Daily Intake (ADI, 0.07 mg/kg bw/day) for all children and adolescents and 2.8% for the consumer group. The major contributors for all subjects and consumers were ham, sausage and bacon. These results indicated that the improved method was suitable for analyzing nitrite in processed foods and the nitrite exposure levels were safe.

Effect of Pulmonary Inflammation by Surface Functionalization of Zinc Oxide Nanoparticles.

Zinc oxide nanoparticles (ZnO NPs) are used in various industries such as food additives, cosmetics, and biomedical applications. In this study, we evaluated lung damage over time by three types of ZnO NPs (L-serine, citrate, and pristine) following the regulation of functional groups after a single intratracheal instillation to rats. The three types of ZnO NPs showed an acute inflammatory reaction with increased LDH and inflammatory cell infiltration in the alveoli 24 h after administration. Especially in treatment with L-serine, citrate ZnO NPs showed higher acute granulocytic inflammation and total protein induction than the pristine ZnO NPs at 24 h. The acute inflammatory reaction of the lungs recovered on day 30 with bronchoalveolar fibrosis. The concentrations of IL-4, 6, TNF-α, and eotaxin in the bronchoalveolar lavage fluid (BALF) decreased over time, and the levels of these inflammation indicators are consistent with the following inflammatory cell data and acute lung inflammation by ZnO NP. This study suggests that single inhalation exposure to functionalized ZnO NPs may cause acute lung injury with granulocytic inflammation. Although it can recover 30 days after exposure, acute pulmonary inflammation in surface functionalization means that additional studies of exposure limits are needed to protect the workers that produce it.

Evaluation of the skin phototoxicity of systemically administered pharmaceuticals in Sprague-Dawley rats.

In vivo phototoxicity testing is important for predicting drug-induced phototoxicity in humans. Currently, there is no internationally validated in vivo test method for the photosafety evaluation of pharmaceuticals. In this study, we evaluated the phototoxicity of systemically administered drugs using SD rats. We first determined the appropriate ultraviolet A (UVA) dose using 8-methoxypsoralen, a well-known phototoxic drug. Compared to lower and higher UVA doses, we found that a UVA dose of 10 J/cm2 allowed for the detection of phototoxic responses in both a dose- and time-dependent manner. We next performed a phototoxicity study using seven pharmaceutical drugs which included known phototoxic and non-phototoxic drugs using a UVA dose of 10 J/cm2. In order to improve the accuracy of our assessment, we evaluated both gross skin findings as well as histopathological findings. Using gross skin findings alone resulted in an accuracy of 85.7% which could be increased to 100% accuracy when the gross skin findings were combined with histopathological findings. This study suggests that the inclusion of histopathological findings increases the accuracy of the phototoxicity evaluation of systemically administered drugs in SD rats. In conclusion, we found that for studying drug-induced phytotoxicity, a 10 J/cm2 UVA dose serves as the optimal radiation dose, and that the inclusion of histopathological findings increases the accuracy of the phototoxicity evaluation of the drugs.

Noise Improvement of a-Si Microbolometers by the Post-Metal Annealing Process.

To realize high-resolution thermal images with high quality, it is essential to improve the noise characteristics of the widely adopted uncooled microbolometers. In this work, we applied the post-metal annealing (PMA) process under the condition of deuterium forming gas, at 10 atm and 300 °C for 30 min, to reduce the noise level of amorphous-Si microbolometers. Here, the DC and temperature coefficient of resistance (TCR) measurements of the devices as well as 1/f noise analysis were performed before and after the PMA treatment, while changing the width of the resistance layer of the microbolometers with 35 µm or 12 µm pixel. As a result, the microbolometers treated by the PMA process show the decrease in resistance by about 60% and the increase in TCR value up to 48.2% at 10 Hz, as compared to the reference device. Moreover, it is observed that the noise characteristics are improved in inverse proportion to the width of the resistance layer. This improvement is attributed to the cured poly-silicon grain boundary through the hydrogen passivation by heat and deuterium atoms applied during the PMA, which leads to the uniform current path inside the pixel.

Broadband responsivity enhancement of Si photodiodes by a plasmonic antireflection bilayer.

Randomly distributed plasmonic Ag nanoparticles (NPs) with various sizes were fabricated by a reflow process to an island-shaped Ag thin-film deposited on a Si photodiode. These NPs conformally enclosed by an antireflective (AR)-type SiNx/SiO2 bilayer reveal significantly diminished reflectance in a broad wavelength (500 nm - 1100 nm) as compared to the cases of Ag NPs or SiO2 layer enclosing Ag NPs on the Si substrate. Accordingly, the forward scattering and the total reflection along with wide-angle interference in between the dielectric bilayer incorporating the Ag NPs induce highly increased light absorption in the Si substrate. The fabricated Si photodiode adopting the plasmonic AR bilayer shows the responsivity peak value of 0.72 A/W at 835 nm wavelength and significant responsivity enhancement up to 40% relative to a bare Si photodiode in a wavelength range of 500 nm to 1000 nm.

Flow cytometric evaluation of the potential of metal oxide nanoparticles for skin sensitization using 5-Bromo-2-deoxyuridine.

Although skin sensitization potential of various chemicals has been extensively studied, there are only a few reports on nanoparticles induced skin sensitization. Aiming to fill this lacuna, in this study we evaluated the potential of metal oxide nanoparticles (NPs) to induce skin sensitization with flow cytometry. Seven different metal oxide NPs, including copper oxide, cobalt oxide, nickel oxide, titanium oxide, cerium oxide, iron oxide, and zinc oxide were applied to Balb/c mice. After selecting the proper vehicle, the NPs were applied, and the skin sensitization potential were assessed using 5-bromo-2-deoxyuridine with flow cytometry. Physiochemical properties such as hydrodynamic size, polydispersity, and zeta potential were measured for the NPs prior to the tests. All the seven metal oxide NPs studied showed negative responses for skin sensitization potential. These results suggest that the OECD TG 442B using 5-bromo-2-deoxyuridine with flow cytometry can be applied to evaluate the potential of NPs for skin sensitization.

Corrigendum: Copper and Cobalt Ions Released From Metal Oxide Nanoparticles Trigger Skin Sensitization.

[This corrects the article DOI: 10.3389/fphar.2021.627781.].