Commercial Kits Research Articles

ELISA genotyping of hepatitis B virus in China with antibodies specific for genotypes B and C

Hepatitis B virus (HBV) causes hepatitis B (HB) and distinct HBV genotypes can lead to different prognoses. However, HBV genotyping is rarely done in clinics, because the traditional method by PCR-based DNA sequencing is impractical for clinical diagnosis with tedious process and low success rate. Herein, we have established an ELISA-based genotyping method to quickly determine the HBV genotypes of HB patients in China. First, two commercial antibodies, 16D12 and 6H3 specific for HBV genotypes B and C respectively, are chosen as capture antibodies, since these two genotypes dominate in China. Then two home-made genotype-specific antibodies, B19 and C04, are used as the detection antibodies for genotypes B and C in sandwiched ELISA. The ELISA kit shows high sensitivity (> 95%) and specificity (> 95%) in detecting genotypes B and C of Chinese HB patients. Moreover, the ELISA kit has demonstrated higher success rate (98.7%) than PCR-based DNA sequencing (93.5%) and a commercial PCR-based genotyping kit (92.2%) for sera with HBV DNA ≥ 1000 IU/mL and HBsAg ≥ 250 IU/mL. Such an advantage is more obvious for the sera with HBV DNA < 1000 IU/mL. The kappa analysis between the ELISA and PCR-based DNA sequencing results exhibits a kappa of 0.836, indicating a good correlation.

Evaluation of Two Commercial ELISA Kits for Measuring Equine Serum Gastrin Compared to Radioimmunoassay.

Gastrin is an important hormone involved in gastric acid secretion. Despite its importance, validated methods other than radioimmunoassay (RIA) to assess serum gastrin concentrations in horses are lacking. This study aims to determine the agreement between ELISA and RIA in quantifying equine serum gastrin concentrations. Serum gastrin concentrations were quantified using two ELISA kits and RIA. Samples (196) from 14 horses at different time points were analyzed using one ELISA kit and RIA, selected samples (7) were analyzed using a second ELISA kit, and the correlation between methods was calculated. The level of agreement was analyzed by Bland-Altman analysis and differences between ELISA and RIA were plotted against averages for each sample. The Pearson correlation between gastrin concentrations measured by ELISA and the RIA was 0.27 and -0.32 for ELISA kit 1 and kit 2, respectively. Mean bias (ELISA-RIA) was 198.40 pg/mL (95% CI: -142.95-539.76) and -17.90 pg/mL (95% CI: -89.98-54.19) for ELISA kit 1 and kit 2, respectively. Measurements of horse gastrin by both ELISA methods were highly variable, with an unacceptable correlation to the reference method, RIA. Using non-validated ELISA methods to quantify horse gastrin cannot be recommended.

Potent α-glucosidase inhibitors with benzimidazole-propionitrile hybridization; synthesis, bioassay and docking study.

Background: Diabetes is characterized by a lack of insulin and insensitivity to insulin. In 2013, the global diabetes population was 382million, with 90% of them having type 2 diabetes (non-insulin-dependent). It is predicted that this number will increase to 592million by 2035.Aim: Here, we aimed to synthesize a series of benzimidazole-based derivatives B1-B32 with α-glucosidase inhibition potential as antidiabetic agents.Methods: Compounds B1-B32 were prepared in three three-step reactions, and the structures were elucidated using spectroscopic methods, namely 1H NMR, 13C NMR, MS and IR. Enzyme inhibition and kinetic study were done using commercial assay kits, and molecular docking study using autodock4.Results: Bioassay data showed that twenty-four out of the thirty-two tested compounds exhibited IC50 values ranging from 44 to 745μM, surpassing the standard molecule, acarbose (IC50: 750μM). it was determined that the best compound, B10, functions as a competitive inhibitor. Additionally, a molecular docking study provided insights into the interactions between the four most promising compounds (B5, B6, B10 and B28) and the active site residues within the enzyme.Conclusion: The tested compounds are interesting α-glucosidase inhibitors, which indicates the benefit of more bioassay studies, especially in vivo studies.

Synergistic ferroptosis in triple-negative breast cancer cells: Paclitaxel in combination with Erastin induced oxidative stress and Ferroportin-1 modulation in MDA-MB-231 cells.

Ferroptosis is an important regulated cell death mechanism characterized by iron-dependent lipid peroxidation and oxidative stress. In this study, we examined the ferroptosis-inducing effect of the combined use of Paclitaxel, a microtubule-stabilizing agent, and Erastin, a ferroptosis inducer, in breast cancer cells. In this context, the combination of the compounds in question was applied to the cells and the presence of a synergistic effect was determined by calculating the combination index. Glutathione (GSH) levels and glutathione peroxidase (GPX) activity were determined by commercial assay kits, and the effect of the compounds on lipid peroxidation was determined by measurement of malondialdehyde (MDA) levels. Additionally, the effect of combination treatment on ferroptotic protein expression was determined by western blot. Our findings revealed that the combination treatment caused a significant change in mitochondrial function by causing an increase in the depolarized/viable cell population. Additionally, there was a significant increase in intracellular reactive oxygen species (ROS) levels compared to single applications of the compounds. The significant increase observed in malondialdehyde (MDA) levels revealed that the combination treatment increased lipid peroxidation. Moreover, intracellular GSH levels and glutathione peroxidase (GPX) activity significantly decreased by Paclitaxel-Erastin combination. The expression of ferroptosis-regulating proteins was significantly downregulated. The findings showed that the Paclitaxel-Erastin combination synergistically contributed to the accumulation of lipid reactive oxygen species and induced the ferroptotic cell death pathway in breast cancer cells.

Prevalence of Toscana Virus Antibodies in Residents of Bulgaria: A Nationwide Study Following the Pandemic of COVID-19.

Introduction: Toscana virus (TOSV) is an arthropod-borne virus transmitted by sandflies and is mainly found in countries around the Mediterranean basin. In this article, we present the findings of a seroprevalence study on TOSV in Bulgaria. We aim to assess the current epidemiological situation regarding TOSV in the country and raise clinical awareness. Methods: Serum samples (n = 1892) were collected in December 2023. Serological tests were performed using a commercial anti-TOSV ELISA kit. Results: Specific immunoglobulin G (IgG) antibodies were detected in 6.4% (121/1892) of the participants. A significantly higher seropositivity rate was found in the age group over 65 years compared with the age groups 18-29 and 40-64 (11.8% vs. 3.9% vs. 3.4%), as well as in males compared with females (8.0% vs. 5.3%). The seroprevalence rates in districts ranged from 0% to 18.5%. Higher seropositivity was found in the southern and northern regions. Conclusions: The seroprevalence rate of TOSV in Bulgaria, found in this study, is a significant decrease compared with the seropositivity rate of 24.5% reported in the country in 2018. The reasons for this are unknown and could possibly be related to the COVID-19 pandemic and the constantly changing environmental conditions. There is also a possibility that the higher seropositivity detected in 2018 together with the rise in clinical cases reported from endemic countries around that time might have been due to an unrecognized TOSV outbreak taking place in this period. Continued clinical awareness and surveillance are necessary for recognition and management of potential cases of TOSV neuroinfection, especially during summer.

Tropisetron attenuates high glucose-induced oxidative stress and inflammation in ARPE-19 cells in vitro via regulating SIRT1/ROCK1 signaling.

Diabetic retinopathy (DR) is the leading cause of acquired blindness in diabetic patients. Tropisetron (TRO) exerts potent therapeutic effects against diabetic tissues. The present study aimed to investigate the effects of TRO on retinal injury under diabetic condition. Human retinal pigment epithelial cell line ARPE-19 was treated with high glucose (HG) for 48 h to mimic hyperglycemia-induced retinal damage and subsequently treated with multiple concentrations of TRO for therapeutic intervention. Cell viability and lactate dehydrogenase (LDH) release were detected to assess cell damage. The production of inflammatory cytokines and oxidative stress-related factors was evaluated by corresponding commercial kits. Cell apoptosis was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. The expression of inflammation-, apoptosis-, and SIRT1/ROCK1-related proteins was examined using western blot analysis. Additionally, ARPE-19 cells were transfected with over-express ROCK1 (Ov-ROCK1) or pretreatment with SIRT1 inhibitor EX527 to perform the rescue experiments. TRO alleviated cell damage in HG-induced ARPE-19 cells through elevating cell viability and reducing LDH release. HG-caused excessive production of TNF-α, IL-1β and IL-6, ROS, malondialdehyde and decreased superoxide dismutase activity were partly inhibited by TRO treatment. HG-induced cell apoptosis, accompanied with the upregulation of proapoptotic proteins and the downregulation of antiapoptotic proteins, was hindered by TRO treatment. HG led to the loss of SIRT1 and an elevation of ROCK1 in ARPE-19 cells, which was reversed following TRO treatment. Furthermore, pretreatment with EX527 or transfected with Ov-ROCK1 partially abolished the protective role of TRO against inflammation, oxidative stress and cell apoptosis in HG-challenged ARPE-19 cells. TRO exerted a protective role against HG-caused ARPE-19 cells inflammation, oxidative stress and cell apoptosis by regulating SIRT1/ROCK1 axis, suggesting that TRO might be therapeutic agent for alleviating retinal pigment epithelial cell damage in DR.

Bezafibrate mitigates cardiac injury against coronary microembolization by preventing activation of p38 MAPK/NF-κB signaling.

Coronary microembolization (CME)-induced inflammatory response and cardiomyocyte apoptosis are the main contributors to CME-associated myocardial dysfunction. Bezafibrate, a peroxisome proliferator-activated receptors (PPARs) agonist, has displayed various benefits in different types of diseases. However, it is unknown whether Bezafibrate possesses a protective effect in myocardial dysfunction against CME. In this study, we aimed to investigate the pharmacological function of Bezafibrate in CME-induced insults in myocardial injury and progressive cardiac dysfunction and explore the underlying mechanism. A CME model was established in rats, and cardiac function was detected. The levels of injury biomarkers in serum including CK-MB, AST, and LDH were determined using commercial kits, and pro-inflammatory mediators including TNF-α and IL-6 were detected using ELISA kits. Our results indicate that Bezafibrate improved cardiac function after CME induction. Bezafibrate reduced the release of myocardial injury indicators such as CK-MB, AST, and LDH in CME rats. We also found that Bezafibrate ameliorated oxidative stress by increasing the levels of the antioxidant GPx and the activity of SOD and reducing the levels of TBARS and the activity of NOX. Bezafibrate inhibited the expression of pro-inflammatory cytokines such as TNF-α and IL-6. Importantly, Bezafibrate was found to mitigate CME-induced myocardial apoptosis by increasing the expression of Bcl-2 and reducing the levels of Bax and cleaved caspase-3. Mechanistically, Bezafibrate could prevent the activation of p38 MAPK/NF-κB signaling. These findings suggest that Bezafibrate may be a candidate therapeutic agent for cardioprotection against CME in clinical applications.

The Development and Application of Lyophilized LAMP Detection Reagent for Listeria monocytogenes.

Listeria monocytogenes, a zoonotic foodborne pathogen, presents a significant threat to global public health. Therefore, rapid and sensitive detection methods are crucial in mitigating the spread of L. monocytogenes induced diseases. This study introduced a loop-mediated isothermal amplification (LAMP) lyophilized powder detection reagent specifically designed for identifying Listeria monocytogenes. The reagent is user-friendly, quick, and can be easily transported and stored at room temperature. It exhibits no cross-reactivity with eight other types of bacteria and boasts a sensitivity of 101CFU/mL. In a comparative study of 30 samples, the LAMP lyophilized powder detection reagent demonstrated higher sensitivity than the commercial Listeria monocytogenes qPCR detection kit. Additionally, the experimental time was reduced by approximately 30min, making it highly suitable for rapid diagnosis. Preparation of lyophilized LAMP reagents may facilitate large-scale deployment, particularly in endemic areas or regions facing rapid outbreaks. This could greatly aid in controlling the transmission of pathogens, especially those transmitted through food.

Quantifying allergenic proteins using antibody-based methods or liquid chromatography-mass spectrometry/mass spectrometry: A review about the influence of food matrix, extraction, and sample preparation.

Accurate quantification of allergens in food is crucial for ensuring consumer safety. Pretreatment steps directly affect accuracy and efficiency of allergen quantification. We systematically reviewed the latest advances in pretreatment steps for antibody-based methods and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) protein quantification methods in food. For antibody-based methods, the effects induced by food matrix like decreased allergen solubility, epitope masking, and nonspecific binding are of the upmost importance. To mitigate interference from the matrix, effective and proper extraction can be used to obtain the target allergens with a high protein concentration and necessary epitope exposure. Removal of interfering substances, extraction systems (buffers and additives), assistive technologies, and commercial kits were discussed. About LC-MS/MS quantification, the preparation of the target peptides is the crucial step that significantly affects the efficiency and results obtained from the MS detector. The advantages and limitations of each method for pre-purification, enzymatic digestion, and peptide desalting were compared. Additionally, the application characteristics of microfluidic-based pretreatment devices were illustrated to improve the convenience and efficiency of quantification. A promising research direction is the targeted development of pretreatment methods for complex food matrices, such as lipid-based and carbohydrate-based matrices.

The effect of Oleoylethanolamide supplementation on lipid profile, fasting blood sugar and dietary habits in obese people: a randomized double-blind placebo-control trial.

Abnormalities in biochemical parameters and changes in eating habits are considered complications of obesity. Oleoylethanolamide (OEA), an endocannabinoid-like compound, has been shown to have protective effects on many metabolic disorders. Given this evidence, the present study aimed to assess the effects of OEA on lipid profile parameters, fasting blood sugar (FBS), and dietary habits in healthy obese people. In this randomized, double-blind, placebo-controlled clinical trial, which was carried out in 2016 in Tabriz, Iran, 60 obese people were enrolled in the study based on inclusion criteria. The intervention group consumed 125mg of OEA capsules, and the placebo group received the same amount of starch twice for 8 weeks. Blood samples (5 mL) were taken at baseline and the end of the study in a fasting state. Serum concentrations of FBS, triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), and total cholesterol (TC) were measured by enzymatic methods using commercial kits. The low-density lipoprotein cholesterol (LDL-C) concentration was obtained using the Friede-Wald formula. To assess dietary habits, a food frequency questionnaire (147 items) was used at baseline and the end of the study. A value less than < 0.05 was considered to indicate statistical significance. The TG concentration decreased significantly in the intervention group (mean (SD): 166.29 (70.01) mg/dL to 142.22 (48.05) mg/dL, p = 0.047). Changes in the placebo group were not significant (p > 0.05). After adjusting for baseline values and demographic characteristics, the difference in TG between groups remained significant (p = 0.044). Changes in other biochemical parameters were not significant. There was no significant difference between or within groups in terms of food groups. OEA, as a complementary agent, plays a protective role in TG regulation. However, future studies with longer durations are needed to explore the impact of OEA on regulating dietary habits and to identify the mechanisms related to metabolic abnormalities in obese people. The study was registered in the Iranian Registry of Clinical Trials (IRCT) center as IRCT201607132017N30 with URL. www.IRCT.IR in date 03/10/2016.

Factors Associated with IgG/IgM Levels after SARS-CoV-2 Vaccination in Patients with Head and Neck Cancer.

This study evaluated the factors influencing IgG/IgM antibody levels in 120 patients with head and neck cancer (HNC) following vaccination with inactivated SARS-CoV-2 vaccines. Each patient's demographic and clinical data were documented, and serum IgG and IgM antibodies were detected using a commercial magnetic chemiluminescence enzyme immunoassay kit. The results indicated that while all patients had received at least one vaccine dose, 95 tested positive for IgG and 25 were negative. A higher proportion of IgG-positive patients had received three vaccine doses. Comparatively, gamma-glutamyl transferase levels were elevated in IgM-negative patients. The study further differentiated patients based on their treatment status: 46 were treatment-naive and 74 had received chemotherapy combined with immune checkpoint inhibitors (ICT) at enrollment. Despite similar baseline characteristics and time from vaccination to antibody detection, IgM positivity was significantly lower in the ICT group, with no significant difference in IgG positivity between the treatment-naive and ICT groups. A multivariable analysis identified the number of vaccine doses as an independent factor of IgG positivity, while ICT emerged as an independent risk factor for IgM positivity. Additionally, IgG titers generally declined over time, although patients with higher baseline IgG levels maintained higher titers longer. In conclusion, ICT in patients with HNC does not significantly affect IgG levels post-vaccination. However, booster vaccinations have been shown to be associated with higher IgG positivity, although these levels gradually decrease over time.

Silencing LncRNA SNHG14 alleviates renal tubular injury via the miR-483-5p/HDAC4 axis in diabetic kidney disease.

This study explored the clinical value of long non-coding RNA small nucleolar RNA host gene 14 (SNHG14) in diabetic kidney disease (DKD) and the mechanism of renal tubular injury. Patients with DKD, type 2 diabetes mellitus (T2DM) and healthy individuals (HVs) were included, as well as the human proximal tubular epithelial cell line (HK-2) induced by high glucose was also included. The mRNA levels of SNHG14 in the serum and cells were detected using RT-qPCR. Diagnostic significance was examined using receiver operating characteristic (ROC) analysis. A commercial test kit, flow cytometry, and enzyme-linked immunosorbent assays were employed to assess reactive oxygen species (ROS) production, apoptosis, inflammatory factor secretion, and extracellular matrix protein levels in HK-2 cells. The dual-luciferase reporter assay and RNA immunoprecipitation were used to validate miR-483-5p concerning SNHG14 or histone deacetylase 4 (HDAC4). SNHG14 and HDAC4 levels were elevated in the serum of DKD patients and HG-induced HK-2 cells, while miR-483-5p levels were decreased (P < 0.001). SNHG14 increased HDAC4 levels by sponging miR-483-5p. Elevated SNHG14 levels significantly differentiated DKD patients from HVs (AUC = 0.944) and T2DM (AUC = 0.867). Silencing of SNHG14 alleviated HG-induced ROS production and apoptosis as well as the over-secretion of inflammatory factors and extracellular matrix proteins; however, this alleviation was typically suppressed by low expression of miR-483-5p (P < 0.001). Elevated miR-483-5p alleviates HG-induced renal tubular injury, but this alleviation is suppressed by HDAC4 overexpression. In summary, suppression of SNHG14 has been shown in our study to mitigate renal tubular injury in DKD by regulating apoptosis, oxidative stress, inflammation, and fibrosis through the miR-483-5p/HDAC4 axis.

Lipocalin-2 as a marker of inflammation, bone density, and triglyceride-glucose index for new-onset arthritis patients in Mosul, Iraq.

Lipocalin-2 is an acute phase-associated adipokine that can serve as an inflammatory and biomarker indicator of cartilage deterioration in osteoarthritis. However, its role in the musculoskeletal system remains not fully understood. Hence, this study aimed to evaluate lipocalin-2 and its relationship with markers of inflammation (Interferon-gamma, ESR, and CRP), bone density (vitamin D3 and calcium), and the triglyceride-glucose index in new-onset arthritis patients in Mosul, Iraq. This study included 125 participants aged 20 to 65, divided into two groups. The Arthritis Patient Group comprised 70 participants (37 females and 33 males) attending the Bone Diseases Consultation Unit at the Ibn Sina Teaching Hospital in Mosul, Iraq. The Control Group comprised 31 females and 24 males. Ethical approval was obtained from the Iraqi Ministry of Health - Nineveh Health (No. 2022095). Commercial ELISA kits were used to measure serum lipocalin-2, Interferon-gamma, ESR, and CRP as inflammation markers, vitamin D3, and calcium as bone density markers. Moreover, the Triglyceride Glucose (TYG) Index was evaluated. The findings revealed a significant increase in lipocalin-2 levels in males compared to females, with LCN-2 increasing with age. Arthritis patients showed a significant increase (72%) in lipocalin-2 levels. Inflammatory indicators (erythrocyte sedimentation rate, C-reactive protein, interferon-gamma) displayed significant increases (46%, 1200%, and 581%, respectively). Glucose (23%), triglycerides (71%), and TYG index (21%) also exhibited significant increases. Meanwhile, bone density indicators (vitamin D3 and calcium) found a significant decrease (53% and 20%, respectively) in arthritis patients. Linear correlation coefficient (R) analysis revealed a significant positive relationship between lipocalin-2 and indicators of inflammation, glucose, TG, and TYG index. This study's findings suggest that LCN-2 serum levels were higher in patients with new-onset arthritis than in controls in Mosul, and LCN-2 serum increased in males compared with females and getting older serum LCN-2 increased for the patients and control groups. Furthermore, a significant correlation was found between the Triglyceride Glucose Index, which measures metabolic disorders, and serum LCN-2 levels and inflammatory indicators in new-onset arthritis patients in Mosul, Iraq.

Genomic Multicopy Loci Targeted by Current Forensic Quantitative PCR Assays

Modern forensic DNA quantitation assays provide information on the suitability of a DNA extract for a particular type of analysis, on the amount of sample to put into the analysis in order to yield an optimal (or best possible) result, and on the requirement for optional steps to improve the analysis. To achieve a high sensitivity and specificity, these assays are based on quantitative PCR (qPCR) and analyze target DNA loci that are present in multiple copies distributed across the genome. These target loci allow the determination of the amount of DNA, the degree of DNA degradation, and the proportion of DNA from male contributors. In addition, internal control DNA of a known amount is analyzed in order to inform about the presence of PCR inhibitors. These assays are nowadays provided as commercial kits that have been technically validated and are compatible with common qPCR instruments. In this review, the principles of forensic qPCR assays will be explained, followed by information on the nature of DNA loci targeted by modern forensic qPCR assays. Finally, we critically draw attention to the current trend of manufacturers not to disclose the exact nature of the target loci of their commercial kits.

12248 Leptin Signaling Deficiency At The Central Nervous System Reduces Hepatic Glucagon Sensibility Disturbing Liver Amino Acid Metabolism Leading To Hyperaminoacidemia And Hyperglucagonemia In Male Adult Rats

Abstract Disclosure: C. Pintado Losa: None. L. Mazuecos Fernández-Pacheco: None. Ó. Gómez Torres: None. S. Artigas Jerónimo: None. E. Burgos Ramos: None. I. Ramos: None. J. Poveda Colado: None. C. Arribas Mocoroa: None. A. Andres: None. N. Gallardo: None. Leptin regulates glucagon secretion, but the contribution of central leptin resistance to circulating glucagon levels and hepatic glucagon signaling is poorly studied. To analyze the effects of deficient hypothalamic leptin signaling on glucagon levels and hepatic glucagon signaling, we infused intracerebroventricularly a rat-specific leptin receptor antagonist SLA (0,2 µg/day) for 21 days to male 3-month-old Wistar rats (n=12) or PBS (n=12). At day 21 of treatment and 30 min before sacrifice, a glucagon challenge (100 µg/kg) was performed in 16h fasted rats. After sacrifice, blood and liver samples were collected for analysis. Serum hormones, urea, and total and branched-chain amino acids (BCAA) levels were determined using commercial kits and by RP-HPLC. Hepatic neutral lipid was extracted and quantified using an enzymatic kit and the hepatic content of mRNA and proteins involved in lipid and amino acid metabolism were measured by RT-PCR and Western-Blot. Additionally, the HOMA-IR and glucagon-alanine index were determined in all rats. Blocking central leptin signaling led to impaired fat oxidation and triglyceride export capacity in the liver, resulting in a 50% increase in hepatic triglyceride content in SLA-treated rats. Glucagonemia increased in SLA-treated rats, indicating impaired hepatic glucagon sensitivity. In fact, in response to exogenous glucagon, the hepatic phosphorylation of CREB was reduced by 55% in SLA-infused compared to control rats. Importantly, SLA treatment significantly decreases the expression and the activity of BCKDH (branched-chain alpha-keto acid dehydrogenase) in the liver, leading to a reduction in the BCAA degradation in SLA-treated rats, hyperaminoacidemia, and decreased serum urea levels. In conclusion, deficient hypothalamic leptin signaling alters glucose, lipid, and amino acid homeostasis, highlighting the relevance of central leptin action in the control of peripheral metabolism and glucagon sensitivity. Funding: Work supported by Ministerio de Ciencia, Innovación y Universidades under project grants RTI2018-098643-B-I00, PID2021-128243OB-I00, and from the University of Castilla-La Mancha and the European Regional Development Fund (FEDER) under project grant 2023- GRIN-34280. Presentation: 6/1/2024

Fluorescence Polarization Assay for Infection Diagnostics: A Review

Rapid and specific diagnosis is necessary for both the treatment and prevention of infectious diseases. Bacteria and viruses that enter the bloodstream can trigger a strong immune response in infected animals and humans. The fluorescence polarization assay (FPA) is a rapid and accurate method for detecting specific antibodies in the blood that are produced in response to infection. One of the first examples of FPA is the non-competitive test for detecting brucellosis in animals, which was followed by the development of other protocols for detecting various infections. Fluorescently labeled polysaccharides (in the case of brucellosis and salmonellosis) or specific peptides (in the case of tuberculosis and salmonellosis, etc.) can be used as biorecognition elements for detecting infections. The availability of new laboratory equipment and mobile devices for fluorescence polarization measurements outside the laboratory has stimulated the development of new fluorescence polarization assays (FPAs) and the emergence of commercial kits on the market for the detection of brucellosis, tuberculosis, and equine infectious anemia viruses. It has been shown that, in addition to antibodies, the FPA method can detect both viruses and nucleic acids. The development of more specific and sensitive biomarkers is essential for the diagnosis of infections and therapy monitoring. This review summarizes studies published between 2003 and 2023 that focus on the detection of infections using FPA. Furthermore, it demonstrates the potential for using new biorecognition elements (e.g., aptamers, proteins, peptides) and the combined use of FPA with new technologies, such as PCR and CRISPR/Cas12a systems, for detecting various infectious agents.

4D-printed shape-programmable [H+]-responsive needles for determination of urea

Four-dimensional printing (4DP) technologies are revolutionizing the fabrication, functionality, and applicability of stimuli-responsive analytical devices. More practically, 4DP technologies are effective in fabricating devices with complex geometric designs and functions, and the degree of shape programming of 4D-printed stimuli-responsive devices can be optimized to become a reliable analytical strategy. Although shape-programming modes play a critical role in determining the analytical characteristics of 4D-printed stimuli-responsive sensing devices, the effect of shape-programming modes on the analytical performance of 4D-printed stimuli-responsive devices remains an unexplored subject. We employed digital light processing three-dimensional printing (3DP) with acrylate-based photocurable resins and 2-carboxyethyl acrylate (CEA)-incorporated photocurable resins for 4DP of the bending, helixing, and twisting needles. Upon immersion in samples with pH values above the pKa of CEA, the electrostatic repulsion among the dissociated carboxyl groups of polyCEA caused swelling of the CEA-incorporated part and [H+]-dependent shape programming. When coupling with the derivatization reaction of the urease-mediated hydrolysis of urea, the decline in [H+] induced shape programming of the needles, offering reliable determination of urea based on the shape-programming angles. After optimizing the experimental conditions, the helixing needles provided the best analytical performance, with the method's detection limit of 0.9 μM. The reliability of this analytical method was validated by determining urea in samples of human urine and sweat, fetal bovine serum, and rat plasma with spike analyses and comparing these results with those obtained from a commercial assay kit. Our demonstration and analytical results suggest the importance of optimizing the shape-programming modes to improve the analytical performance of 4D-printed stimuli-responsive shape-programming sensing devices and emphasize the benefits and applicability of 4DP technologies in advancing the development and fabrication of stimuli-responsive sensing devices for chemical sensing and quantitative chemical analyses.

IgG reactivity to different desmoglein-3 ectodomains in pemphigus vulgaris: novel panels for assessing disease severity.

Pemphigus vulgaris (PV) is an autoimmune disease characterized by IgG autoantibodies targeting desmoglein-3 (Dsg3), leading to blistering of mucous membranes and skin. Although commercial ELISA kits effectively diagnose PV, correlation with clinical phenotype remains unclear. This study assesses multiple panels for monitoring disease severity and activity by profiling IgG autoantibodies against Dsg3's various extracellular ectodomains. We designed and expressed different extracellular domains of Dsg3 in HEK293T cell line and developed 15 different ELISA panels, each using a single or multi ectodomains encompassing the entire extracellular region of Dsg3 to detect specific autoantibodies against the particular part of Dsg3. To validate our approach, we compared our ELISA panel for the full Dsg3 (EC1-5) against a commercial kit using 154 random serum samples from PV patients, demonstrating a strong correlation. For evaluation of IgG autoantibody profiles in our panels, 59 PV patients were included, along with 11 bullous pemphigoid patients, and 49 healthy controls. For all the included subjects, 15 predefined ELISA panels were tested. The IgG autoantibodies against EC1 were detected in 86% of patients with a positive full Dsg3 ectodomain (EC1-5) ELISA, with 26% against EC2, 14% for EC3, 29% for EC4, and 23% for EC5. Among the panels with multiple Dsg3 ectodomains, EC1-3 and EC1-4 were representative of the entire Dsg3 ectodomain in terms of ELISA positivity across all included patients. A significant correlation (P<0.05) was observed between ELISA optical density (OD) and Pemphigus Disease Area Index (PDAI) scores in five panels, EC1, EC2-3, EC2-5, and EC3-4 in addition to the full ectodomain. It suggests an association with disease severity. Interestingly, while the ELISA panel for the entire Dsg3 extracellular ectodomains did not differentiate disease phases, in three of our panels, including EC1, EC3-5, and EC2-5, ANOVA analysis showed a statistically significant difference between the groups of patients in remission, partial remission or persistent lesions, and those with active disease (new cases or relapse). Among these three panels, EC1 was the only one that showed a significant difference in the multiple comparisons analysis; patients in the active phase had higher levels of autoantibodies than those in 'partial remission or persistent lesions' and 'complete remission' groups. The level of autoantibodies against EC1 was not only correlated with the full ectodomain but also associated with higher disease severity and active disease phase. This study indicates that a detailed autoantibody profile against Dsg3 ectodomains could serve as a marker for PV severity and activity which may potentially enhance early treatment initiation.

B-154 Development and Evaluation of an Automated High-Throughput Magnetic Bead-Based pre-treatment Platform for Lipid-Soluble Vitamins in Clinical Mass Spectrometry

Abstract Background Mass spectrometry has become a critical tool in clinical diagnostics due to its unparalleled sensitivity, specificity, and ability for multiplex analysis, redefining standards in small molecule detection. However, its efficacy is limited by complex sample preparation requirements, such as purification and enrichment. Traditional pre-treatment methods often involve labor-intensive, error-prone procedures that can dilute samples, thereby necessitating enhanced sensitivity in mass spectrometry. Addressing these challenges, we developed an automated, high-throughput pre-treatment platform using magnetic bead technology to streamline the preparation of small molecules for analysis via liquid chromatography-tandem mass spectrometry (LC-MS/MS). This study assesses the platform's effectiveness and reliability using lipid-soluble vitamins as a test case. Methods We developed a magnetic bead-based extraction process for lipid-soluble vitamins (Vitamins A, 25-hydroxyvitamin D2, 25-hydroxyvitamin D3, E, and K1) from clinical serum samples, utilizing Zybio's EXM3000 for automation. Protein-bound vitamins were dissociated using methanol and isopropanol, followed by magnetic bead extraction. The extracted vitamins underwent LC-MS/MS analysis. Comparative analysis with traditional liquid-liquid extraction methods, using 20 clinical samples and commercially available kits, evaluated this novel approach's analytical efficacy. Results The method showed excellent linearity (r &amp;gt; 0.99) for the target compounds. The imprecision ranged from 1.5% to 9.3%, and the accuracy (recovery rate) was between 91.5% and 113.4%. The limit of quantification, repeated six times, had a deviation of -8.5% to 13% and a CV of 1.5%-6.4%, meeting industry standards and EP document requirements. Comparisons with commercial kits in 20 clinical samples showed deviations within ±15%, and the 95% confidence interval for expected bias met the testing requirements. The method also demonstrated high correlation with the commercial kits, as evidenced by regression equations for Vitamin A: y = 0.9732x - 1.7985, 25-hydroxyvitamin D2: y = 1.0163x - 0.0055, 25-hydroxyvitamin D3: y = 1.0597x - 0.7968, Vitamin E: y = 1.0569x - 0.2917, and Vitamin K1: y = 1.0055x - 0.0039. Conclusions This study showed excellent performance of a novel automated high-throughput magnetic bead sample preparation platform for small molecules in clinical mass spectrometry. This technology overcomes the complexities associated with sample pre-treatment in clinical mass spectrometry and holds broad clinical application prospects in mass spectrometric analysis.

B-229 Extraction-free Nucleic Acid Sample Preparation from Inhibitor Rich Samples via Hyperbaric Heating

Abstract Background Extraction-based nucleic acid sample preparation for PCR is limited by long processing times, liquid transfers, cost, and storage requirements. Extraction-free approaches enable streamlined sample prep but are severely impacted by inhibitors present in biological sample matrices. We previously reported the use of Hyperbaric Heating (HBH) for effective organism lysis and demonstrate here its effectiveness to prepare nucleic acids for PCR from various inhibitor-rich sample matrix types. Methods HBH exposes the sample to high temperature/high pressure environment for a short duration. This process effectively lyses organisms and denatures inhibitors within seconds. Samples are sealed within a pressure-tight metallic vessel, then rapidly heated using magnetic induction. Within the sealed metallic vessel, vaporization of the aqueous sample raises the internal pressure, enabling an internal temperature higher than 100°C. Proprietary sample processing beads containing chelating agents and other proteins protect nucleic acids from fragmentation during heating. Results The efficacy of HBH for PCR amplification was tested against commercial kits and extraction-free methods. HBH treatment of nasal swab samples spiked with inactivated SARS-CoV-2 elicited detection down to 125 viral copies/mL. Viruses such as RSV and Influenza spiked in nasal swab samples demonstrated comparable PCR results as extraction prepped samples. HBH treatment of microbe samples, including Candida albicans spiked in urine and Bacillus subtilis spiked in serum, had comparable PCR threshold cycles as microbe specific DNA extraction methods (Table 1). Conclusions HBH is a generalizable extraction-free nucleic acid sample prep technology affording detection capabilities comparable to commercial sample prep methods. We demonstrated the use of HBH sample prep for detection of several infectious microorganisms in common biological matrices (nasal swab, serum, urine) without additional sample purification. With its ease of use, speed, and lower cost, HBH will be a key tool in applications where nucleic acid amplification is pivotal for diagnostic and research use.