bluuebunny/crossref_metadata_2025 huggingface dataset:
B-143 Distribution of Uricemia Levels in the Population of a Third-level Hospital. Study of the Prevalence of Hypouricemia
Authors: Corominas A I , Casal G H , Vommaro F M , Riquelme G B , Balconi S M , Damiano A E
Published: September 2023

Hypouricemia is a serum uric acid concentration ≤2.0 mg/dL. The causes may be congenital or acquired. Despite not being recognized as a relevant biomarker, the knowledge of the importance of uric acid in redox homeostasis and the hierarchization of hyperuricemia as an independent risk factor in metabolic diseases justifies a reassessment of the significance of the state of acquired hypouricemia. We aimed to study the prevalence of hypouricemia and its relationship with the referred patients’ ages, genders, and morbidities. A descriptive, quantitative study was carried out, through the survey and analysis of biochemical records and clinical records. We worked with the database of the laboratory’s system between January and October 2019, with the data groups of adult patients (≥16 years) that included serum uric acid dosage. The concomitant biochemical parameters (Urea, creatinine, white blood cell count, glucose) were evaluated, and the diagnoses and treatments were collected in the electronic medical record. To define the prevalence, we worked with the first analysis group of each patient. All statistical analyzes were carried out with the Statistix™ software version 7. The criteria for statistical significance were P < 0.05. We found that of the total 159 971 data groups from January to October 2019, 17 983 were selected. There were 234 patients with hypouricemia analyzed. The prevalence of patients with hypouricemia was 2.22%. In our population, postmenopausal women did not match the distribution of uricemia levels to that of men, nor did the mean values of each distribution. Men had higher levels of uric acid than women in any age situation. The prevalence of hypouricemia agrees with what is described in the literature. Of women with hypouricemia, 39% were in the process of pregnancy. Besides that, most patients had a pathology, less than 10% were present for health control, or did not have data in the clinical record. The prevalence of oncological pathology (46%) as a comorbidity in patients with hypouricemia (oncohaematological tumors more frequent than solid ones) and diabetes (22%) was striking. Hypouricemia values were more frequent in outpatients (70%) than in hospitalized patients, however, the last ones showed lower values (1.46 ± 0.4 mg/dL vs 1.52 ± 0.35 mg/dL). The white blood cell count values (0.1–26 * 103 cells/µL) and glucose (0.3–3.76 g/L) that accompany the hypouricemia situation behold pathological values, and the urea and creatinine values were normal. Because this is a retrospective work, we do not have studies of fractional excretion of uric acid, which could delve into the causal research of hypouricemia. Further studies are needed to elucidate the causes of hypouricemia and to clarify its value in diagnosing and treating diseases.
B-155 Sigma Metric Equation Proposed by James O. Westgard is Wrong
Authors: Brooks Z C
Published: September 2023

Background

2022 AACC Poster #132 of the same title described how the Westgard sigma metric equation of [A] SM = (TEa - Bias)/SD proposed by James O. Westgard is NOT wrong when compared to the industrial practice of calculating sigma as [B] the difference between the mean and nearest upper or lower tolerance limit divided by the SD. Formulae [A] and [C] produce the same results. The often-recommended practice of calculating sigma as [C] Sigma = (%TE -|%Bias|)/CV%, however, produces results that differ from either formulae described above whenever bias is not zero. This formula [C] using percentages is therefore wrong.

Methods

Sigma values were calculated as [A] (TEa - |Bias)|/SD and as [C] (%TE -|%Bias|)/CV% on fourteen routine chemistry analytes and four cardiac markers tested on two Ortho Vitros 5600 analyzers from September to December 2022. CLIA TEa limits were selected as TEa limits for each analyte; bias was calculated as Current Mean - Peer Mean. Sigma tables were used to convert sigma to defects per million results. Eight-six of 320 data sets with sigma metrics from 2.25 to 5.25 were graphed to compare calculated sigma values and #failures/year.

Results

Comparison of sigma metrics calculated from formula [A] and [C] revealed 1. An R² = 1.00 if all 320 values with sigma metrics from 0.71 to 30.8; 2. An R² = 0.92 when the range was truncated to the 86 samples with sigma from 2.25 to 5.25; and 3. An R² value of only 0.75 when the same sigma values are converted to the number of results failing TEa limits per one million patent samples.

Conclusion

Calculations of sigma metrics based on %Bias and %CV are incorrect. This is exacerbated when sigma is converted to the number of patient failures per million results.
B-181 Multi-centre Analytical Performance Evaluation of the EXENTâ Solution for Identification and Quantitation of Monoclonal Immunoglobulins
Authors: Stanton R , McEntee D , Matters D , Ijaz S , Khalid A , Barnidge D , Ouverson L , Sakrikar D , Ashby J , Marrott N , Ghobrial I M , El-Khoury H , Bertamini L , Fleming G , Horowitz E , Neish A S , Solis Z M , McLendon K B , North S
Published: September 2023

Background

Current routine methodologies for monoclonal immunoglobulin measurements may not be sufficiently sensitive to reflect the depth of response seen in patients since the introduction of novel therapies; mass spectrometry may offer a valuable, sensitive alternative approach. Here we describe the preliminary analytical performance characteristics of the EXENT® solution (in development by The Binding Site, part of Thermo Fisher scientific) that combines specific immunoprecipitation steps and mass spectrometry for the identification and quantification of IgG, IgA and IgM intact monoclonal immunoglobulins. Each intact monoclonal immunoglobulin clone can be tracked using its unique m/z value.

Methods

The Lower Limit of Measuring Interval (LLMI) was established for each immunoglobulin type following EP17-A2:2012. Linearity studies were performed according to CLSI EP06-A2:2020 using high and low pools of IgG, IgA, and IgM monoclonal samples and with additional linearity testing below 1 g/L for each specificity to more effectively demonstrate low-end linearity. Within run, between run, between analyzer, between lot and total precision for M protein concentrations and for molecular mass (m/z) of the monoclonal peaks were assessed according to CLSI EP5-A3-2014. Interference was tested following ED3:2018 using 20 potential interferents against 7 samples including high and low IgG, IgA and IgM monoclonal samples.

Results

The initial indication of the EXENT solution performance, in development, are set out below. Results suggest an analytical sensitivity of the assays around 15 mg/L at the LLMI for all specificities. Linearity over a range of 0.014–88.9 g/L for IgG, 0.011–68.4 g/L for IgA, and 0.11–74.2 g/L for IgM. Coefficients of variation (CVs) for M protein concentrations in precision studies were <15% for all specificities and samples. Mass/charge values were within ±1.1 to ±1.5 m/z in total precision studies, and within ±2.7 to ±3.9 m/z in between lot precision studies, respectively, for M proteins with an m/z value ranging from 11 360.6 to 11 698.5 m/z. No significant interference effects were observed when testing the 20 interferents including intralipid (20 g/L), triglyceride (15 g/L), bilirubin (400 mg/L), rheumatoid factor (200 IU/mL) and haemoglobin (10 g/L).

Conclusion

The new EXENT solution demonstrates the potential for a wide measuring interval and the ability to detect M proteins with very low concentration. Also, it could provide stable and reproducible performance for the detection and typing of monoclonal immunoglobulins.
B-208 Correlation Studies of Human Papillomavirus DNA on Roche Cobas vs Human Papillomavirus mRNA on Hologic Panther
Authors: Teng J
Published: September 2023

Background

Molecular testing, specifically HPV DNA has revolutionised the screening and management of cervical cancer. WHO in 2021 has recommended HPV DNA as the primary screening test and also the newer technology HPV mRNA as alternative assay. This evaluation aims to study the result concordance between HPV DNA and mRNA assay.

Methods

The evaluation was conducted on Roche Cobas 4800 (HPV DNA) and Hologic Panther (HPV mRNA) at NHGD IMH lab in 2021. Both instruments underwent precision studies and carryover test to ascertain its performance prior to the concordance study. 64 samples were used in the correlation against the reference method- HPV DNA testing on Roche Cobas 6800.

Results

Both Cobas 4800 and Hologic Panther demonstrated acceptable performance in precision, carryover and LoD (for Hologic only). However closer result agreement is observed in Roche 4800 results to the testing laboratory, Quest which is using Roche 6800.

Conclusion

The disconcordance between cobas 6800 vs cobas 4800 came from the negative samples in cobas 4800 in which their Ct value were found to be near to the detection limit. Similar to Cobas 4800, the discordance observed in Hologic came from the negative samples. However, HPV mRNA screening has been recognized for its higher specificity at baseline in the recent studies which improve clinical outcomes and reduce colposcopy referrals by 14%. Unfortunately, this could not be verified in our evaluation as colposcopy results for those HPV DNA positive sample were not available.
B-215 Use of Whole Exome Sequencing and T Cell Receptor β Repertoires Analysis for Identifying Potential Genetic Variants in Rheumatoid Arthritis
Authors: Cho J , Lee H , Ahn S , Song J , Kim J , Lee J
Published: September 2023

Background

Rheumatoid arthritis (RA) is one of the most prevalent autoimmune diseases, which is reported to affect about approximately 1% of the adult population worldwide. And, it is associated with progressive disease courses, systemic complications, early mortality, and a high socioeconomic burden. The pathogenesis of RA is too complex to be fully understood yet, but abnormal and pathogenic T-cell responses that evade normal immune functions could be considered one of the mechanisms of RA development. Herein, we used whole exome sequencing (WES) and T cell receptor/T cell receptor β repertoires analysis (TCR/TRB) to identify the potential genetic variants in RA.

Methods

Peripheral blood samples from 18 RA patients and 5 healthy controls were analyzed. For RA patients, the baseline naïve samples were collected before disease-modifying anti-rheumatic drugs treatment was started, and both WES and TRB were tested. After 6 months and 12 months of treatment initiation, additional samples were collected and TRB was tested. A total of 18 WES and 27 TRB tests were conducted. WES was done on the MGI-G400 platform (MGI Tech Co., Ltd., Shenzhen, China) and TCR/TRB was done using the LymphoTrack TCR/TRB assay (Invivoscribe Technologies, San Diego, CA, USA) on the MiSeq system (Illumina Inc, San Diego, CA, USA).

Results

In RA patients, deleterious variants that have been reported to be relevant in various diseases were identified in a total of 217 genes. Among 18 RA patients, 5 (27.8%) patients had variants that were suspected to be associated with the pathogenesis of RA, including JAK3, PADI4, TNFSF18, TRAF1, NFKB, etc. Of the 27 TCR/TRB tests, 10 TCR (37.0%) and 14 TRB (51.9%) results had significant changes in RA patients.

Conclusion

The aim of this study is to provide clinical evidence for developing diagnostic and/or prognostic markers for RA. Further analysis whether these variants found in this study are clinically significant and valuable as markers in RA. In addition, it is expected that the results of our study will be used as basic data applied to other rheumatoid diseases such as systemic lupus erythematosus and Bechet’s disease.
B-222 Validation of a qPCR Method for Qualitative Detection of Monkeypox Virus
Authors: Chan A , Amaro K , Bui C , Camarena O , Dang A , Herron D , Lara J , Lim L , Lopez P , Mayoralgo M , Nguyen A , Nguyen J , Ortega B , Pham A , Tran K , Bach D
Published: September 2023

Background

The 2022 Monkeypox virus (MPXV) outbreak became a global concern, prompting a multidisciplinary response to increase surveillance and isolate suspected and confirmed cases to reduce disease spread. Quantitative PCR (qPCR) is capable of detecting small amounts of DNA or RNA, and can be used to quickly and accurately confirm MPXV cases, even at early stages of infection, which is crucial for outbreak control and management.

Methods

qPCR was performed on a 384-well plate with a total reaction volume of 20 μl consisting of 9 μL Acrometrix Monkeypox DNA Positive Control at serial dilutions, 10 μL BactoPure Master Mix, and 1 μL TaqMan Monkeypox Virus Microbe Detection Assay. Positive control dilutions 103, 102, 101, and 100 were diluted with TE Buffer. qPCR was performed on two different Quantstudio 12K Flex instruments.

Results

The qPCR method validation was performed by calculating precision, accuracy, and linearity on serial dilutions of Acrometrix Monkeypox Virus DNA Positive Control. Precision testing was performed on 2 levels of control: low (101) and high (103) over 5 days with 4 repeats per day. Accuracy and linearity testing were performed on 4 levels with 3 repeats. Coefficient of variation (CV) was less than 5%, specifically 0.9% for the low control and 4.3% for the high control, indicating an acceptable level of precision. Percent recovery fell close to 100%, specifically within 101%-103% for all controls, indicating the results fell close to the expected value. Linearity R2 was close to 1, specifically 0.984, demonstrating the results are proportional to the concentration analyzed.

Conclusion

Validation of MPXV detection through qPCR was successful. Development and validation of qPCR assays for the detection of positive MPXV cases is essential for managing future outbreaks and combatting future pathogenic strains.
B-274 One-step Detection of Candida Albicans, Trichomonas Vaginalis and Gardnerella Vaginalis
Authors: Peris M , Milagro A , Gilaberte B , Gamadiel N , López M , Dehesa-García B , García-Manrique B , Mendoza C , Aabad P , Rezusta A
Published: September 2023

Background

Trichomonas vaginalis and Candida albicans infections and bacterial vaginosis (BV) are among the three main causes of vaginitis.The most widespread method for diagnosis is still Gram staining and culture. The disadvantages are the microscopy time required, as cultures are examined after 24–48 h. Different commercial molecular biology kits are currently available on the market to detect these pathogens in a sensitive, specific and rapid way.In vitro diagnostic products must be marketed with CE and IVD certification for marketing in the European Union and must be externally validated with clinical samples. For this reason, the company Certest Biotec proposes a collaborative study to evaluate the product VIASURE C. albicans, G. vaginalis & T. vaginalis Real Time PCR Detection Kit, in the Microbiology Laboratory of the Miguel Servet University Hospital (HUMS) in Zaragoza (Spain) using samples characterised by Gram and culture as positive or negative for C. albicans, G. vaginalis and T. vaginalis.

Methods

240 DNA extracts of clinical samples from vaginal swabs of patients with suspected vaginitis were analysed. For the validation of the kit under study, the Segene® AllplexTM Vaginitis Screening Assay was used as a reference. Discordant results will be resolved by Sanger sequencing. Preliminary results are therefore expressed as true positives, true negatives, false positives and false negatives. The use of clinical samples was approved by CEIC Aragón (CEICA): PI20/426.

Results

In the absence of resolution of the discordances by sequencing, the results were as indicated in Table 1.

Conclusion

The main advantage of using these techniques is speed, as they can provide results on the same day and reduce the time spent on microscopy and culture reading. VIASURE products are in a stabilised, ready-to-use format, which facilitates handling, avoids possible contamination, allows storage at room temperature and transport.
B-304 Performance of Alternative Proficiency Testing Program for Bayesian Forecasting Tool of Infliximab Exposure in Clinical Pharmacokinetic Laboratory
Authors: Caonguyen S , McLachlan O , Pham D , Hughes P , Dervieux T
Published: September 2023

Background

We have developed a Bayesian (PK) forecasting and dosing tool for Infliximab (IFX), a monoclonal antibody targeting Tumor necrosis factor α. This novel dosing tool employs machine learning and proficiency of the algorithm must be established. Our objective was to implement an alternative proficiency testing program (APT) in the routine clinical (PK) laboratory.

Methods

The test (PredictrPK® IFX) is validated and measures serum IFX and antibodies to IFX (ATI) concentrations using a homogenous mobility shift assay by size exclusion HPLC and albumin (ALB) by nephelometry. Determinations are inputted with weight, dose, and interdose interval provided on test requisition in the Bayesian forecasting PK tool which uses non-linear mixed effect to calculate the individual parameter estimates, Clearance and predicted trough concentrations. APT is conducted using five previously tested patient samples, blinded to testing personnel and retested in the same manner as the routine method of analysis every six months. APT consists of two components, a component evaluating standalone IFX, ATI, and ALB analytes, and a second component evaluating the Bayesian forecasting PK tool in estimating Clearance and trough concentrations. Criteria for acceptable performance is set at target value ± 20% for standalone analytes and forecasted PK estimates. Acceptable ATP score corresponds to 4/5 samples with passing grade.

Results

The results from two consecutive APT results with six months intervals is presented in Fig. 1. Comparing the results to the original assayed data at the time of collection, the APT results showed IFX concentration, ATI and ALB within 20% of target value. Clearance and estimated trough concentrations calculated using the Bayesian forecasting tool also met acceptability criteria (100% passing grade).

Conclusion

We have implemented an APT for Bayesian forecasting tool in the clinical PK laboratory.
B-309 Development and Validation of a LC-MS/MS Method for Highly Concentrated Tacrolimus and Cyclosporine Specimens Prepared from Clinical Pharmaceutical Products to Assess Adsorption By Feeding Tubes
Authors: Xiao Y , Leung E
Published: September 2023

Background

Tacrolimus and cyclosporine are common immunosuppressive drugs used in the prevention and treatment of solid-organ transplant rejection (e.g., kidney, liver, heart). Other indications include several autoimmune diseases such as Crohn’s disease, autoimmune hepatitis, and rheumatoid arthritis. To prevent toxicity while achieving therapeutic efficacy, tacrolimus and cyclosporine in whole blood specimens are commonly measured in medical centers so that their dosages can be precisely adjusted. Different from adult patients, pediatric patients often require smaller doses and the use of feeding tubes for drug administration. In order to assess nonspecific adsorption by feeding tubes, we modified our in-house clinical method to measure highly concentrated tacrolimus and cyclosporine specimens prepared from clinical pharmaceutical products.

Methods

Highly concentrated tacrolimus and cyclosporine specimens were serially diluted with dimethyl sulfoxide (2000 times for tacrolimus and 20 000 times for cyclosporine) before measurements by our clinical method using liquid chromatography mass spectrometry. The method for highly concentrated tacrolimus and cyclosporine was validated, with analytical measurement range determined with in-house prepared concentrated specimens at varying concentrations, precision (repeatability and reproducibility) assessed by multiple measurements of concentrated specimens at three different concentrations, accuracy assessed by recovery studies, and matrix effect assessed by post-column infusion and by matrix dilution with dimethyl sulfoxide.

Results

The method was linear from 10 ug/mL to 80 ug/mL for tacrolimus, and 1 mg/mL to 8 mg/mL for cyclosporine with r2 > 0.99. Repeatability and reproducibility were <10% CV. Minimal matrix effect was observed. Recovery studies using commercial calibrators to measure specimens prepared from reference materials and dimethyl sulfoxide identified no significant bias for tacrolimus but an average positive bias of 20% for cyclosporine, and a correction factor was used to finalize cyclosporine results for specimens prepared from clinical pharmaceutical products. The positive bias was eliminated when calibrators were prepared in dimethyl sulfoxide.

Conclusion

We have developed and validated a LC-MS/MS method for the measurement of highly concentrated tacrolimus and cyclosporine in specimens prepared from clinical pharmaceutical products. We hypothesize that one or more components in the commercial calibrators have contributed to the positive bias of cyclosporine in those specimens. Our method can be used to support studies that assess nonspecific adsorption by feeding tubes.
B-318 Development of Non-competitive Immunoassay System for Cyclosporine a Using Alpaca Naïve Library-derived VHH
Authors: Fukuya S , Tanaka M , Hotta Y , Kitamori Y , Kiyose N , Miyazaki N , Ise N , Aoyagi K
Published: September 2023

Background

Cyclosporine A is a potent immunosuppressive drug. It has a narrow therapeutic index, and therefore the measurement of cyclosporine’s blood concentration is essential to obtain optimal therapy. Cyclosporine A, a small cyclic polypeptide, is generally measured by competitive immunoassay, which is theoretically inferior to noncompetitive sandwich immunoassay in terms of sensitivity and specificity. In this study, we report a novel sandwich immunoassay for cyclosporine A using an alpaca naïve library-derived variable domain of heavy chain of heavy chain antibody (VHH) developed against an immunocomplex of cyclosporine A and anti-cyclosporine A mouse monoclonal antibody.

Methods

We generated a VHH against an anti-cyclosporine A mouse monoclonal antibody complexed with cyclosporine A by alpaca naïve VHH phage display library. A bivalent tandem VHH was generated using the established VHH, and a new sandwich immunoassay for measuring cyclosporine A was constructed using the tandem VHH conjugated with alkaline phosphatase. A prototype fully automated sandwich immunoassay was developed on a fully automated chemiluminescence analyzer using magnetic particles immobilized with the mouse monoclonal antibody and the tandem VHH conjugated with alkaline phosphatase. The prototype assay was further developed by implementing an automated whole blood pretreatment process with strong denaturing agents. The performances of the prototype immunoassays were investigated.

Results

The established VHH showed a highly specific reaction to the complex of cyclosporine A and the anti-cyclosporine A mouse monoclonal antibody, and a sandwich immunoassay for cyclosporine A was successfully developed using the VHH and the mouse monoclonal antibody. The tandem bivalent VHH exhibited higher reactivity to the complex than the monomeric VHH. The fully automated reagent prototype achieved a measurement range of 30 to 1500 ng/mL. Measurement of cyclosporine A in whole blood samples by the prototype reagent showed a correlation coefficient of 0.96 with mass spectrometry, and a correlation coefficient of 0.95 with a commercial IVD reagent.

Conclusion

We successfully developed a sandwich reagent prototype for cyclosporine A using VHH established by alpaca naïve VHH phage display library. This is the first report of a fully automated reagent for cyclosporine A measurement including an automated whole blood pretreatment process.
B-324 Comparison of Two Urine Fentanyl Assays on the Abbott Alinity c Analyzer
Authors: Laryea E T , Manning S , Nichols J H
Published: September 2023

Background

Mass spectrometry (MS) remains the gold standard, however immunoassays can provide a preliminary test result while the patient is still in the emergency room or clinic.

Methods

The ARK Fentanyl II assay (ARK Diagnostics Inc, Fremont, CA) was compared to the Immunalysis SEFRIA Fentanyl (Immunalysis Corporation, Pomona, CA) assay on the Abbott Alinity c analyzer (Abbott Park, IL) using leftover deidentified urine samples. MS analysis was performed at ARUP Laboratories (Salt Lake City, UT) to quantitate the amount of fentanyl or norfentanyl metabolite in each sample. Medications prescribed at the time of sampling were reviewed to assess for possible cross reactivity with the assays.

Results

A total of 142 urine samples were analyzed with 70 MS positive and 72 MS negative samples. Positive and negative assay specific quality control precision (N = 10) was 3.0% and 9.6% CV for the ARK Fentanyl II assay and 10.2% and 15.9% CV for the Immunalysis SEFRIA assays respectively. ARK Fentanyl II Sensitivity = 95.7%, Specificity = 94.4%, PPV = 94.4%, NPV = 95.8% and Efficiency = 95.1% compared to the Immunalysis SEFRIA Fentanyl Sensitivity = 95.7%, Specificity = 81.9%, PPV = 83.8%, NPV = 95.2% and Efficiency = 88.7%. Upon repeat analysis, 4 of 4 ARK and 6 of 13 Immunalysis false positives reported as negative, indicating some variability around the cutoff concentration. Possible carryover from high samples has also been reported (ARK Technical Note 20-001-August 2020) and high samples were analyzed prior to some of the false positive samples. Six MS positive samples were reported as negative (false negatives), 3 samples by each of the assays. However, 4/6 of those samples had combined fentanyl and norfentanyl concentrations <3 ng/mL by MS.

Conclusion

The ARK Fentanyl II and Immunalysis SEFRIA assays demonstrated acceptable performance in the detection of fentanyl in our patient population.
B-328 Analytical Performance of a Screening Test for Lead Using Dried Blood Spots and ICP-MS
Authors: Orahoske C M , Cieslak W , Payto D M , Chegwidden E , Colón-Franco J
Published: September 2023

Introduction

There is no safe blood lead levels (BLL) in children and exposure can cause irreversible neurological harm. In 2021, the CDC decreased the blood lead reference value (BLRV) to 3.5 ug/dL from 5.0 ug/dL, based on the 97.5th percentile of BLL among US children under 5 years of age. Despite this, lead poisoning disproportionately affects Black children, those below poverty levels, and living in houses built before 1978. The American Academy of Pediatrics recommends targeted screening for BLL in children aged 12–24 months living in high prevalence areas. Children enrolled in Medicaid also require screening by 24 months of age. Only one-third of children who require screening receive it and lead screening declined by >50% during the COVD-19 pandemic. Quality improvement strategies have included electronic health record alerts and point of care testing. To improve screening rates in our pediatric population, we developed a screening method utilizing dried blood spot (DBS) cards. This study aimed to validate the accuracy and precision of this screening method with emphasis on the performance around the BLRV cut-offs, which would be used to determine the need to follow up with a confirmatory venous lead test.

Methods

The method was calibrated using certified reference material traceable to NIST SRM 3128 (VHG labs, Manchester, NH, USA) in whole blood. The calibrators, controls and patient samples were spotted onto Whatman 903 cards. A 6 mm filter paper disc in extraction buffer was vortexed, allowed to sit at room temperature for 30 min and centrifuged. The samples were analyzed on the Thermo Fisher iCAP RQ and TQ (Whaltman, MA) in kinetic energy discrimination mode. The assay has a linear range of 1–100 µg/dL, and the recovery ranged from 92%–102%. We evaluated this method for reproducibility, and accuracy across the measurement range. In this study, we focused on the reproducibility and accuracy of DBS at lead concentrations around the BLRV cut-offs. We used in 2 samples spiked with NIST CRM 3128 (Inorganic Ventures, Christiansburg, VA, USA) analyzed 10 times over 3 days and 13 leftover patient samples run over at least 5 days. The total allowable error was 2 µg/dL or 10%.

Results

In two samples spiked to BLL of 3.5 and 3.9 µg/dL, interday precision (n = 10) ranged from 3.4% to 17.4% (SD 0.1–0.7) in samples run for 3 days. Removal of an apparent outlier decreased the %CV ranged observed to <8.5%. The average bias for each day ranged from 0.1 to 0.6 µg/dL. In 13 patient samples with concentrations around the BLRV ranging from 1.4 to 5.8 µg/dL, the coefficient of variation (CV) ranged from 0.2% to 32% with the largest SD at 0.8 µg/dL. The average bias for this sample set was -0.3 (11.7%).

Conclusion

The assay’s analytical performance is sufficient for screening purposes, but the clinical performance and the impact of introducing this test to enhance screening rates during 1 and 2 years well visits need to be evaluated further.
B-381 A Multiplex Blood-based Assay Targeting DNA methylation in Peripheral Blood Mononuclear Cells Enables Early Detection of Breast Cancer
Authors: Wang C , Li J , Wang T
Published: September 2023

Background

The immune system can monitor the development of tumors, and the DNA methylation is involved in the body immune response to tumors. Therefore, the DNA from peripheral blood mononuclear cell (PBMC) that carries cancer-specific epigenetic aberrations may serve as a non-invasive marker for early detection of breast cancer (BC).

Methods

Genome-wide DNA methylation profiling on PBMC DNA from BC patients and healthy controls (Cohort I, n = 80) was performed in the discovery phase by Infinium 850K BeadChips. The candidate CpG sites were selected and validated in a multistep validation phase (Cohort II, n = 200) via pyrosequencing and targeted bisulfite sequencing. After that, the multiplex quantitative methylation-specific PCR assay (mBC-MSP) was established to detect BC, and the performance of this diagnostic method was analyzed in a multicenter cohort (Cohort III, n = 501).

Results

A total of 289 differentially methylated CpG positions (DMPs) between BC patients and healthy controls were identified. Among them, eight significant DMPs markers were selected and further validated using pyrosequencing and targeted bisulfite sequencing, and four hyper-methylated DMPs (cg18637238, cg16652347, cg13828440, cg11754974) passed the final validation. Then, we developed a mBC-MSP assay based on the four methylated markers. This assay exhibited excellent performance in distinguishing BC patients, with an AUC of 0.925, sensitivity of 83.1%, and specificity of 90.4%. More importantly, compared with CA153, CA125 and CEA, the mBC-MSP assay had higher sensitivity for early-stage BC (stage 0, 88.2% vs 0%, 0%, 5.9%) and minimal tumor with diameter ≤1.5 cm (91.7% vs 0%, 2.1%, 0%).

Conclusions

The mBC-MSP assay based on the four identified DNA methylation markers from PBMC can serve as a noninvasive, accurate, rapid, and high-throughput method for early diagnosis of BC, and it is more sensitive than traditional tumor markers for detecting early-stage BC and minimal tumor.
Cancer and the risk of perioperative arterial ischaemic events
Authors: Navi Babak B , Zhang Cenai , Kaiser Jed H , Liao Vanessa , Cushman Mary , Kasner Scott E , Elkind Mitchell S V , Tagawa Scott T , Guntupalli Saketh R , Gaudino Mario F L , Lee Agnes Y Y , Khorana Alok A , Kamel Hooman
Published: September 2023

Background and aims

Most cancer patients require surgery for diagnosis and treatment. This study evaluated whether cancer is a risk factor for perioperative arterial ischaemic events.

Methods

The primary cohort included patients registered in the National Surgical Quality Improvement Program (NSQIP) between 2006 and 2016. The secondary cohort included Healthcare Cost and Utilization Project (HCUP) claims data from 11 US states between 2016 and 2018. Study populations comprised patients who underwent inpatient (NSQIP, HCUP) or outpatient (NSQIP) surgery. Study exposures were disseminated cancer (NSQIP) and all cancers (HCUP). The primary outcome was a perioperative arterial ischaemic event, defined as myocardial infarction or stroke diagnosed within 30 days after surgery.

Results

Among 5 609 675 NSQIP surgeries, 2.2% involved patients with disseminated cancer. The perioperative arterial ischaemic event rate was 0.96% among patients with disseminated cancer vs. 0.48% among patients without (hazard ratio [HR], 2.01; 95% confidence interval [CI], 1.90–2.13). In Cox analyses adjusting for demographics, functional status, comorbidities, surgical specialty, anesthesia type, and clinical factors, disseminated cancer remained associated with higher risk of perioperative arterial ischaemic events (HR, 1.37; 95% CI, 1.28–1.46). Among 1 341 658 surgical patients in the HCUP cohort, 11.8% had a diagnosis of cancer. A perioperative arterial ischaemic event was diagnosed in 0.74% of patients with cancer vs. 0.54% of patients without cancer (HR, 1.35; 95% CI, 1.27–1.43). In Cox analyses adjusted for demographics, insurance, comorbidities, and surgery type, cancer remained associated with higher risk of perioperative arterial ischaemic events (HR, 1.31; 95% CI, 1.21–1.42).

Conclusion

Cancer is an independent risk factor for perioperative arterial ischaemic events.
Marine CSEM synthetic study to assess the detection of CO2 escape and saturation changes within a submarine chimney connected to a CO2 storage site
Authors: Yilo Naima K , Weitemeyer Karen , Minshull Timothy A , Attias Eric , Marin-Moreno Hector , Falcon-Suarez Ismael H , Gehrmann Romina , Bull Jonathan
Published: September 2023

Carbon capture and storage (CCS) within sealed geological formations is an essential strategy to reduce global greenhouse gas emissions, the primary goal of the 2015 United Nations Paris Agreement. Large-scale commercial development of geological CO2 storage requires high-resolution remote sensing methods to monitor CO2 migration during/after injection. A geological formation containing a CO2 phase in its pore space commonly exhibits higher electrical resistivity than brine-saturated (background) sediments. Here, we explore the added value of the marine controlled-source electromagnetic (CSEM) method as an additional and relevant geophysical tool to monitor moderate to significant changes in CO2 saturation within a fluid conduit breaking through the seal of a CCS injection reservoir, using a suite of synthetic studies. Our 2-D CSEM synthetic models simulate various geological scenarios incorporating the main structural features and stratigraphy of two North Sea sites, the Scanner Pockmark and the Sleipner CCS site. Our results show significant differentiation of leakage through the seal with CO2 saturation ($S_{{\rm CO}_2}$) ranging between 20 and 50 per cent, while our rock physics model predicts that detection below 20 per cent would be challenging for CSEM alone. However, we are able to detect with our 2-D inversion models the effects of saturation with 10 and 20 per cent CO2 within a chimney with 10 per cent porosity. We demonstrate that simultaneous inversion of Ey and Ez synthetic electric field data facilitates a sharper delineation of a CO2 saturated chimney structure within the seal, whereas Ez synthetic data present higher sensitivity than Ey to $S_{{\rm CO}_2}$ variation, demonstrating the importance of acquiring the full 3-D electric field. This study illustrates the value of incorporating CSEM into measurement, monitoring and verification strategies for optimal operation of marine CCS sites.
Cryo-EM and biochemical analyses of the nucleosome containing the human histone H3 variant H3.8
Authors: Hirai Seiya , Kujirai Tomoya , Akatsu Munetaka , Ogasawara Mitsuo , Ehara Haruhiko , Sekine Shun-ichi , Ohkawa Yasuyuki , Takizawa Yoshimasa , Kurumizaka Hitoshi
Published: September 2023

Histone H3.8 is a non-allelic human histone H3 variant derived from H3.3. H3.8 reportedly forms an unstable nucleosome, but its structure and biochemical characteristics have not been revealed yet. In the present study, we reconstituted the nucleosome containing H3.8. Consistent with previous results, the H3.8 nucleosome is thermally unstable as compared to the H3.3 nucleosome. The entry/exit DNA regions of the H3.8 nucleosome are more accessible to micrococcal nuclease than those of the H3.3 nucleosome. Nucleosome transcription assays revealed that the RNA polymerase II (RNAPII) pausing around the superhelical location (SHL) −1 position, which is about 60 base pairs from the nucleosomal DNA entry site, is drastically alleviated. On the other hand, the RNAPII pausing around the SHL(−5) position, which is about 20 base pairs from the nucleosomal DNA entry site, is substantially increased. The cryo-electron microscopy structure of the H3.8 nucleosome explains the mechanisms of the enhanced accessibility of the entry/exit DNA regions, reduced thermal stability and altered RNAPII transcription profile.
Galaxy spectral classification and feature analysis based on convolutional neural network
Authors: Wu Ying , Tao Yihan , Fan Dongwei , Cui Chenzhou , Zhang Yanxia
Published: September 2023

Emission-line galaxy classification plays an important role in comprehending the formation and evolution of galaxies. The widely used optical spectral classification method for galaxies is the BPT diagram, which classifies emission-line galaxies on the basis of precise spectral line measurements. Various classical machine learning methods have been utilized to classify galaxy spectra. Deep learning (DL) is more feasible for a huge amount of data, as it can learn patterns autonomously from the original data. This study aims to explore the possibility of applying DL to classify galaxy spectra and improve classification efficiency. A one-dimensional convolutional neural network model called GalSpecNet was constructed to classify emission-line galaxy spectra, which recognizes star-forming, composite, active galactic nucleus (AGN), and normal galaxies with an accuracy of over 93 per cent. This study employs the Gradient-weighted Class Activation Mapping to elucidate the decision-making process of the model by inspecting spectral features that the model prioritizes for each type of galaxy. The findings suggest that the model considers features highly consistent with the conventional BPT method. Subsequently, we applied the model to the cross-matched galaxies of Sloan Digital Sky Survey Data Release 16 (DR16) and Large Sky Area Multi-Object Fiber Spectroscopic Telescope DR8 and present a catalogue comprising of 41 699 star-forming candidates and 55 103 AGN candidates. The catalogue is publicly available.
The impact of stochastic modelling on the predictive power of galaxy formation simulations
Authors: Borrow Josh , Schaller Matthieu , Bahé Yannick M , Schaye Joop , Ludlow Aaron D , Ploeckinger Sylvia , Nobels Folkert S J , Altamura Edoardo
Published: September 2023

All modern galaxy formation models employ stochastic elements in their sub-grid prescriptions to discretize continuous equations across the time domain. In this paper, we investigate how the stochastic nature of these models, notably star formation, black hole accretion, and their associated feedback, that act on small (< kpc) scales, can back-react on macroscopic galaxy properties (e.g. stellar mass and size) across long (> Gyr) time-scales. We find that the scatter in scaling relations predicted by the EAGLE model implemented in the swift code can be significantly impacted by random variability between re-simulations of the same object, even when galaxies are resolved by tens of thousands of particles. We then illustrate how re-simulations of the same object can be used to better understand the underlying model, by showing how correlations between galaxy stellar mass and black hole mass disappear at the highest black hole masses (MBH > 108 M⊙), indicating that the feedback cycle may be interrupted by external processes. We find that although properties that are collected cumulatively over many objects are relatively robust against random variability (e.g. the median of a scaling relation), the properties of individual galaxies (such as galaxy stellar mass) can vary by up to 25 per cent, even far into the well-resolved regime, driven by bursty physics (black hole feedback), and mergers between galaxies. We suggest that studies of individual objects within cosmological simulations be treated with caution, and that any studies aiming to closely investigate such objects must account for random variability within their results.
When Intra- and Interthematic Functions Collide: Conflation in Robert Schumann’s Orchestral Sonata Forms
Authors: Poon Matthew
Published: September 2023

This article analyzes formal fusion in the first movements of Schumann’s Symphonies Nos. 1 and 2 and the finale of his Overture, Scherzo, and Finale. Within these pieces, fusion results from what Julian Horton (2015) calls “conflation”—that is, a process in which previously distinct formal levels collapse into each other—resulting in two new categories of sonata expositions I term bipartite and undivided. These categories help explain some of the unique features of Schumann’s orchestral music and provide new tools toward understanding nineteenth-century form.
Prescribing the dialysis dose and treatment frequency in home haemodialysis
Authors: Casino Francesco Gaetano , Roblero Maria Fernanda Slon , González-Sanchidrian Silvia , Dominguez Sandra Gallego , Ferris Ignacio Lorenzo , Luyckx Valerie A , Liakopoulos Vassilios , Mitra Sandip , Lorenzo Javier Deira , Basile Carlo
Published: September 2023

Background

There is growing interest in home haemodialysis (HHD) performed with low-flow dialysate devices and variable treatment schedules. The target standard Kt/V (stdKt/V) should be 2.3 volumes/week, according to KDOQI guidelines (2015). The current formula for stdKt/V does not help prescribe the dialysis dose (eKt/V) and treatment frequency (TF). The aim of this study was to obtain a formula for stdKt/V that is able to define the minimum required values of eKt/V and TF to achieve the targeted stdKtV.

Methods

Thirty-eight prevalent patients on HHD were enrolled. A total of 231 clinical datasets were available for urea modelling using the Solute-Solver software (SS), recommended by KDOQI guidelines. A new formula (stdKt/V = a + b × Kru + c × eKt/V) was obtained from multivariable regression analysis of stdKt/V vs eKt/V and residual kidney urea clearance (Kru). The values of coefficients a, b and c depend on the treatment schedules and the day of the week of blood sampling for the kinetic study (labdayofwk) and then vary for each of their foreseen 62 combinations. For practical purposes, we used only seven combinations, assuming Monday as a labdayofwk for each of the most common schedules of the 7 days of the week.

Results

The stdKt/V values obtained with SS were compared with the paired ones obtained with the formula. The mean ± standard deviation stdKt/V values obtained with SS and the formula were 3.043 ± 0.530 and 2.990 ± 0.553, respectively, with 95% confidence interval +0.15 to –0.26. A ‘prescription graph’ was built using the formula to draw lines expressing the relationship between Kru and required eKt/V for each TF. Using this graph, TF could have been reduced from the delivered 5.8 ± 0.8 to 4.8 ± 0.8 weekly sessions.

Conclusions

The new formula for stdKtV is reliable and can support clinicians to prescribe the dialysis dose and TF in patients undergoing HHD.
A strict vegetarian diet may be harmful: bilateral macular bleeding in vitamin B12 deficiency
Authors: Singh Jitendra , Dinkar Anju
Published: September 2023

A 35-year-old Indian male office worker presented with complaints of progressive weakness, fatigability, and diminished vision. The patient followed a strict vegetarian diet. Clinical examination revealed pallor. Fundoscopy revealed a bilateral macularbleed. Vitamin B12 deficiency was determined to be the cause based on the clinical and laboratory results. Three months later, he reported a near-normal vision in both eyes and a normal complete hemogram. The present clinical picture demonstrates an unusual facet of clinical feature in vitamin B12 deficiency, an event rarely encountered.
Polyarteritis nodosa in a patient with chronic hepatitis B following COVID-19 vaccination: a case report
Authors: Abuhammad Aseel , Dukmak Osama N , Asad Diya , Bakri Izzeddin A , Attawna Saed I Y
Published: September 2023

Different types of vasculitis have been reported after various vaccine administrations. Recently, the coronavirus disease 2019 (COVID-19) vaccine was one of the most common vaccine-induced vasculitis. Herein, we describe a 56-year-old male patient with chronic hepatitis B who presented with abdominal pain for 2 days, which was associated with vomiting and bloody diarrhea. He had a history of petechial rash for 25 days, multiple joint pain and lower limb weakness after the second dose of the COVID-19 vaccine. A skin biopsy showed medium-sized vessel vasculitis. Polyarteritis nodosa (PAN) was diagnosed depending on the American College of Rheumatology criteria. He was treated with steroids, plasmapheresis and antiviral medication with a good prognosis. In patients with a past medical history of chronic hepatitis B, the covid vaccine may be associated with an increased risk of developing a PAN, so clinicians should suspect the occurrence of this disease after COVID-19 vaccination.
A case of anti-HMGCR myopathy in a patient with breast cancer and anti-Th/To antibodies
Authors: Chérif Mohammad Yassine , Raftakis Ioannis , Weynand Marjolaine , Dragan Elena , Nagant Carole , Lecomte Sophie , Badot Valérie
Published: September 2023

Statins competitively inhibit the activity of HMGCR (3-hydroxy-3-methylglutaryl coenzyme A reductase), which is a key enzyme in cholesterol synthesis. These are effective drugs for the management of cardiovascular disease and are generally well tolerated but several side effects have been reported. Muscular adverse symptoms are various and, rarely, statin exposure may lead to authentic immune-mediated necrotizing myopathy (IMNM), namely anti-HMGCR myopathy. However, cases of IMNM associated with cancer have been described. We discuss herein a case of IMNM in a patient with breast cancer previously exposed to statins and with the presence of anti-Th/To antibodies without clinical correlation.
Plant Organellar MSH1 Is a Displacement Loop–Specific Endonuclease
Authors: Peñafiel-Ayala Alejandro , Peralta-Castro Antolin , Mora-Garduño Josue , García-Medel Paola , Zambrano-Pereira Angie G , Díaz-Quezada Corina , Abraham-Juárez María Jazmín , Benítez-Cardoza Claudia G , Sloan Daniel B , Brieba Luis G
Published: September 2023

MutS HOMOLOG 1 (MSH1) is an organellar-targeted protein that obstructs ectopic recombination and the accumulation of mutations in plant organellar genomes. MSH1 also modulates the epigenetic status of nuclear DNA, and its absence induces a variety of phenotypic responses. MSH1 is a member of the MutS family of DNA mismatch repair proteins but harbors an additional GIY-YIG nuclease domain that distinguishes it from the rest of this family. How MSH1 hampers recombination and promotes fidelity in organellar DNA inheritance is unknown. Here, we elucidate its enzymatic activities by recombinantly expressing and purifying full-length MSH1 from Arabidopsis thaliana (AtMSH1). AtMSH1 is a metalloenzyme that shows a strong binding affinity for displacement loops (D-loops). The DNA-binding abilities of AtMSH1 reside in its MutS domain and not in its GIY-YIG domain, which is the ancillary nickase of AtMSH1. In the presence of divalent metal ions, AtMSH1 selectively executes multiple incisions at D-loops, but not other DNA structures including Holliday junctions or dsDNA, regardless of the presence or absence of mismatches. The selectivity of AtMSH1 to dismantle D-loops supports the role of this enzyme in preventing recombination between short repeats. Our results suggest that plant organelles have evolved novel DNA repair routes centered around the anti-recombinogenic activity of MSH1.