Sensitive Test Research Articles

Some Pro-inflammatory Cytokines Levels in Staphylococcal infection

Staphylococci is gram-positive, spherical cells, they are commonly distributed in the environment often part of normal human flora. Staph. aureus, Staph. saprophyticus, and Staph. epidermidis are the three most significant clinically important pathogens. Cytokines are small secreted proteins (<40 kDa), which are produced by nearly every cell to regulate and affect immune response (96). Proinflammatory cytokines are proteins that have been associated with cell proliferation, differentiation, and changes in gene expression, and synthesis of matrix proteins important to cell growth and tissue repair, these proteins are often released in a cascade, where an initial release of TNF is followed first by IL-1 and then by IL-6. 110 clinical samples include 110 throat swap and 60 saliva samples were collected from tonsillitis patients in Kirkuk of both gender and different age groups. Sterile cotton swab were used for throat swab and sterile container for saliva collection. The results showed that Staphylococcus aureus scored highest percentage (59%), followed by Staph. hemolyticus (15%) compared to Staph. epidermidis that scored lowest percentage (2.4%). A sensitivity test was carried out for all bacterial isolates, Staphylococcus spp. showed high resistance to Cefotoxin (, Benzyle-pencillin (, Ampicillin-Sulbactam(, Oxacillin (, Ceftriaxone (, and Erythromycin(, while Staphylococcus spp. showed high sensitive to Linezolid (100%), Teicoplanin (100%), Vancomycin (100%), and Rifampicin (100%). Staph. aureus scored high mean levels at IL-6 (14.51±13.1 ng/L) compared with other Staphylococcus spp. (0.52±0.1 ng/L), while Staph. aureus scored (90.47±77.79 pg/ml) compared with other Staphylococcus spp. (113.0±79.9 pg/ml).

Performance Study of Eco‐Friendly and Safe Pyrotechnics for Fireworks

AbstractThe combustion of traditional pyrotechnics will pose great risks to the environment and human health. Although sulfur‐free pyrotechnics prepared from metals or expired military gunpowder have been used to solve this problem, the high sensitivity of them has resulted in insufficient safety. Therefore, new eco‐friendly and safe pyrotechnics are urgently needed. In this study, we prepared novel metal‐free pyrotechnic compositions for fireworks based on 5‐amino tetrazole. The optimized formulations are proposed by calculation. Particle size effects on thermal stability and kinetics are tested. Then, the sensitivity tests, moisture absorption, and burst temperature test were analyzed and compared. The combustion heat and specific volume were also measured. The Py‐GCMS and PM2.5 were used to clarify the composition of gas products and confirm their environmental‐friendly performance. The findings revealed that the novel pyrotechnics has a small amount of combustion residue, greater safety performance, and less PM2.5 concentration. The novel pyrotechnics could generate 564.9 mL/g clean and non‐toxic gas composed of 93.2% N2, H2O, and CO2 without any NOx or SO2 vapor. The test results suggest that the new pyrotechnics can effectively increase gas production and reduce the content of CO and PM2.5. So, it has great potential in application.

Optic Nerve Sheath Fenestration: A Retrospective Review of Its Safety, Efficacy, and Impact on Optical Coherence Tomography.

This study aimed to evaluate the safety and efficacy of optic nerve sheath fenestration using visual acuity, perimetry, and optical coherence tomography. A retrospective review of patients who underwent an optic nerve sheath fenestration at an academic center between 2016 and 2021 was performed with institutional review board approval. Outcome measures included visual acuity, perimetric mean deviation, optic disc edema grade, improvement in symptoms, and intraoperative and postoperative complications. Optical coherence tomography data collected included macular ganglion cell volume and thickness, as well as retinal nerve fiber layer thickness. Preoperative baseline data and 1-, 6-, and 12-month postoperative data were collected. Repeated measures with a mixed-effects model were used for continuous data, and linear regression analyses were performed. A total of 55 patients (86 eyes) underwent optic nerve sheath fenestration, via a medial transconjunctival approach by the same orbital surgeon. After 12-month follow-up, visual acuity (P < 0.05), perimetric mean deviation (P < 0.05), and optic disc edema (P < 0.001) improved in the operative eye. Retinal nerve fiber layer thickness decreased from a mean of 165 to 92 µm (P < 0.001). Macular ganglion cell volume was found to have a small decrease from baseline and correlated well with visual acuity, contrast sensitivity testing, and perimetric mean deviation (P < 0.001). Optic nerve sheath fenestration performed via a medial transconjunctival approach is a safe and effective method to preserve vision in patients with papilledema, particularly in cases of fulminant or progressive idiopathic intracranial hypertension. Quantitative measurements of the macular ganglion cell layer can serve as a useful adjunct to other diagnostic testing.

Systematic evaluation of the correlation between serum metabolites and tinnitus

Objective: We performed a Mendelian randomisation (MR) analysis to explore the relationship between serum metabolites and tinnitus. Methods: In this study, 486 serum metabolites were considered as exposure factors, and single nucleotide polymorphisms (SNP) significantly associated with them were used as instrumental variables (IV). The serum metabolite data were obtained from a public database (http://metabolomips.org/gwas/index.php), while the genome-wide association study (GWAS) summary association statistics for tinnitus were obtained from a Finnish database (https://r10.finngen.fi/pheno/H8_TINNITUS). The inverse variance weighting (IVW) method was employed as the primary determination method for MR analysis, with corrections for multiple comparisons made using the false discovery rate (FDR). Sensitivity tests were conducted using the MR-Egger regression, Mendelian random polymorphism residuals and outliers (MR-PRESSO) methods. The identified serum metabolites were subjected to chained disequilibrium regression analysis (LDSC) and metabolic pathway analysis. Reverse MR analysis was performed to investigate the possibility of reverse causality. Analyses were performed in R software (version 4.3.1). Results: A total of 17 serum metabolites (including 10 known and 7 unknown metabolites) associated with tinnitus were identified. The known metabolites included protective metabolites such as acetylcarnitine, hydroxyisovaleryl carnitine, glycine, monounsaturated glycerol ester, and glycine-L-valine, and hazardous metabolites such as allantoin, glycerylphosphorylcholine 1-eicosatrienoate, myo-inositol, 15-methylpalmitate, and pseudouridine; the strongest causally protective metabolites were acetylcarnitine, the followed by hydroxyisopentanoyl carnitine and glycine; the hazardous metabolite with the strongest causal effect was pseudouridine, followed by inositol and 15-methylpalmitate; and only hydroxyisopentanoyl carnitine (PFDR=0.04) and glycerol monooleate (PFDR=0.04) reached significance values after FDR correction. The findings were free of heterogeneity, pleiotropy and reverse causal associations. The metabolic pathways were mainly enriched in pathways such as ascorbic acid and aldolac metabolism. Conclusions: The study suggests a causal relationship between serum metabolites and tinnitus risk. Serum metabolite levels may influence tinnitus-related metabolic pathways.

Causality between diabetes and membranous nephropathy: Mendelian randomization.

Membranous nephropathy (MN) has not yet been fully elucidated regarding its relationship with Type I and II Diabetes. This study aims to evaluate the causal effect of multiple types of diabetes and MN by summarizing the evidence from the Mendelian randomization (MR) study. The statistical data for MN was obtained from a GWAS study encompassing 7979 individuals. Regarding diabetes, fasting glucose, fasting insulin, and HbA1C data, we accessed the UK-Biobank, within family GWAS consortium, MAGIC, FinnGen database, MRC-IEU, and Neale Lab, which provided sample sizes ranging from 17,724 to 298,957. As a primary method in this MR analysis, we employed the Inverse Variance Weighted (IVW), Weighted Median, Weighted mode, MR-Egger, Mendelian randomization pleiotropy residual sum, and outlier (MR-PRESSO) and Leave-one-out sensitivity test. Reverse MR analysis was utilized to investigate whether MN affects Diabetes. Meta-analysis was applied to combine study-specific estimates. It has been determined that type 2 diabetes, gestational diabetes, type 1 diabetes with or without complications, maternal diabetes, and insulin use pose a risk to MN. Based on the genetic prediction, fasting insulin, fasting blood glucose, and HbA1c levels were not associated with the risk of MN. No heterogeneity, horizontal pleiotropy, or reverse causal relationships were found. The meta-analysis results further validated the accuracy. The MR analysis revealed the association between MN and various subtypes of diabetes. This study has provided a deeper understanding of the pathogenic mechanisms connecting MN and diabetes.

Method for the design and evaluation of binary sensitivity tests

Abstract For many materials or specimen, their resistance to stress is an important (safety) characteristic. The target value is the event stress, i.e., the value of the stress at which the (adverse) event occurs. Depending on the test procedure and the test items, the event stress cannot always be measured directly but must be determined by binary sensitivity tests. A method for the evaluation of binary sensitivity tests based on the principle of Maximum Likelihood is presented and compared to other methods (traditionally) applied. Sensitivity testing of explosives and fatigue testing of metallic materials are used as real examples to illustrate application of the method and to compare actual results. The method presented delivers not only the estimate of the stress at any specified probability of the event but also the respective 95 % confidence interval. Application of the method is facilitated because it does not require the data to be obtained in a staircase procedure, can process any kind of input data (e.g., as measured or logarithmic), and does not require the stress levels to be equidistant. The method is easily applicable for any laboratory because it is implemented into an Excel file, which is made freely available at https://www.statistics-wilrich.info.

Analysis of the changes of bacterial spectrum and drug resistance in sputum culture of ICU children in a hospital of pediatric in Jiangsu Province from 2017 to 2022

Objective: To investigate the changes of the distribution and drug resistance profile of bacteria from ICU children with lower respiratory tract infection (LRTI) in Suzhou City, Jiangsu Province from 2017 to 2022. Methods: From January 2017 to December 2022, a cross-sectional observational study on the bacterial spectrum analysis among intensive care unit (ICU) children with LRTI was conducted in Children's Hospital of Soochow University. The bacteria was cultivated by culture methods from sputum samples, and identified by MALDI-TOF mass spectrometry. Drug sensitivity tests were performed by the VITEK2 Compact fully automated analysis system and the paper slide method. The χ2 test or Fisher's exact probability was used to analyze the changes of the distribution of sputum culture-positive bacteria and drug resistance in ICU children. Results: The overall detection rate of sputum culture was 42.06% (1 182/2 810). Staphylococcus aureus (25.63%,303/1 182), Acinetobacter baumannii (13.62%,161/1 182) and Haemaphilus influenzae (13.28%,157/1 182) were the top three. Proportions of Acinetobacter baumannii (17.90% vs. 11.02%,χ²=11.17, P=0.001), especially carbapenem-resistant Acinetobacter baumannii (43.70% vs. 23.50%, χ²=15.21, P<0.001) increased significantly from 2020 to 2022. However, the proportions of Haemophilus influenzae (8.50% vs. 16.19%, χ²=14.27, P<0.001), Streptococcus pneumoniae (8.50% vs. 15.92%, χ²=13.42, P<0.001) and extended-spectrum-lactamase producing Escherichia coli (8.89% vs. 18.00%, χ²=5.45, P=0.025) decreased. Drug resistant results showed that Acinetobacter baumannii was obviously more resistant to imipenem (χ²=4.43, P=0.035) and levofloxacin (χ²=12.53, P<0.001), while more sensitive to minocycline (χ²=8.34, P=0.004). Escherichia coli showed a significant increase in resistance to piperacillin tazobactam (χ²=8.29, P=0.008) and cefoperazone sulbactam (χ²=5.07, P=0.024) from 2020 to 2022; Klebsiella pneumoniae consistently maintained a resistance rate of more than 60% to first and second-generation cephalosporins, and remain susceptible to quinolones and carbapenems. Staphylococcus aureus remained highly susceptible to levofloxacin (drug resistance rate: 2.31%,7/303) and sulfamethoxazole/trimethoprim (drug resistance rate: 4.95%,15/303) from 2020 to 2022. Conclusion: Higher detection and resistance rates of Acinetobacter baumannii from sputum culture in ICU children from 2020 to 2022 were explored. Resistance of Escherichia coli to β-lactamase inhibitor combinations was more serious. Regular monitoring the changes of the etiology of respiratory tract infections in ICU Children is particularly important for the prevention and treatment of multidrug-resistant bacterial infections.

A highly sensitive Photothermal Immunochromatographic test strip for detection of aflatoxin B1 based on CoS@TA Nanospheres

A novel photothermal immunochromatographic test strip (PITS) with tannic acid (TA) modified cobalt sulfide (CoS) nanospheres (CoS@TA) as immuno-probe element was developed for the detection of aflatoxin B1 (AFB1). CoS nanospheres (CoS NPs) with excellent photothermal conversion efficiency (η = 47.5 %) was synthesized and skillfully chelated with TA to improve its dispersion, biocompatibility, and chromatographic properties. After modification, the CoS@TA coupled with monoclonal antibody (mAb) against AFB1 (CoS@TA-mAb) by simple physical adsorption. The CoS@TA based PITS achieved highly sensitive detection of AFB1 with the limit of detection in photothermal signal (photothermal-LOD) of 0.00503 μg/L, which was 19.88-fold higher than the LOD in visual signal (visual-LOD, 0.1 μg/L). The application of TA in the modification of CoS provided ideas to improve the properties of functional nanomaterials such as dispersion and biocompatibility, and the application of CoS@TA in PITS construction laid a methodological foundation for further improving the detection sensitivity of trace targets.

Development of a Triplex qPCR Assay Based on the TaqMan Probe for the Detection of Haemophilus parasuis, Streptococcus suis Serotype 2 and Pasteurella multocida

Porcine respiratory disease is a significant economic problem for the global swine industry. Haemophilus parasuis (H. parasuis), Streptococcus suis (S. suis), and Pasteurella multocida (P. multocida) are three important pathogenic bacteria of the swine respiratory tract. Notably, the three pathogens not only frequently manifest as mixed infections, but their striking clinical similarities also present difficulties for pig populations in terms of disease prevention and treatment. Thus, we developed a triplex real-time quantitative polymerase chain reaction (qPCR) assay based on a TaqMan probe for the detection of H. parasuis, S. suis serotype 2, and P. multocida. Primers and probes were designed to target the conserved regions of the H. parasuis OmpP2 gene, the S. suis serotype 2 gdh gene, and the P. multocida Kmt1 gene. By optimizing the reaction system and conditions, a triplex qPCR method for simultaneous detection of H. parasuis, S. suis serotype 2, and P. multocida was successfully established. The amplification efficiencies of the standard curves for all three pathogens were found to be highly similar, with values of 102.105% for H. parasuis, 105.297% for S. suis serotype 2, and 104.829% for P. multocida, and all R2 values achieving 0.999. The specificity analysis results showed that the triplex qPCR method had a strong specificity. The sensitivity test results indicated that the limit of detection can reach 50 copies/μL for all three pathogens. Both intra- and inter-assay coefficients of variation for repeatability were below 1%. This triplex qPCR method was shown to have good specificity, sensitivity, and reproducibility. Finally, the triplex qPCR method established in this study was compared with the nested PCR as recommended by the Chinese national standard (GB/T34750-2017) for H. parasuis, the PCR as recommended by the Chinese national standard (GB/T 19915.9-2005) for S. suis serotype 2, and the PCR as recommended by the Chinese agricultural industry standard (NY/T 564-2016) for P. multocida by detecting the same clinical samples. Both methods are reasonably consistent, while the triplex qPCR assay was more sensitive. In summary, triplex qPCR serves not only as a rapid and accurate detection and early prevention method for these pathogens but also constitutes a robust tool for microbial quality control in specific pathogen-free pigs.

Current regulatory requirements for stability studies of biological medicinal products: a review

INTRODUCTION. The stability assessment of biological medicinal products (BMPs) requires special approaches and regulatory requirements. Therefore, BMPs require relevant national guidelines, which are an important prerequisite for the assurance of the safe and effective use of BMPs.AIM. This study aimed to analyse national and international requirements for the stability assessment of BMPs in order to use the results to inform future development of a unified regulatory approach to estimating and confirming shelf-life periods for BMPs.DISCUSSION. Most biotechnological medicinal products (BTMPs) are proteins and are highly sensitive to environmental factors by nature. Therefore, the shelf life of a BTMP is established on the basis of real-time stability studies. Stability testing under accelerated and stress conditions is conducted to support shelf-life claims and to characterise the mechanism of protein structure degradation. The results of accelerated and stress studies can be used to select the most sensitive stability-indicating parameters and testing methods. National and international regulatory authorities have developed specialised guidelines for stability studies of BMPs of various origins, and the stability assessment approaches in the regulatory system of the Eurasian Economic Union (EAEU) are harmonised with international standards. Special considerations associated with the stability of vaccines imply that stability studies of vaccines should not only establish shelf life but also investigate stability after reconstitution and after short-term temperature excursions from the recommended cold-chain conditions.CONCLUSIONS. Special stability testing considerations for various groups of BMPs (including BTMPs and immunobiologicals) indicate the need to develop and improve the system of requirements for BMP stability assessment. This will facilitate the optimisation of the life cycle of BMPs in the Russian Federation and the other EAEU member states.

Development of biomarker signatures associated with anoikis to predict prognosis in patients with esophageal cancer: An observational study.

Anoikis, a form of programmed cell death linked to cancer, has garnered significant research attention. Esophageal cancer (ESCA) ranks among the most prevalent malignant tumors and represents a major global health concern. To ascertain whether anoikis-related genes (ARGs) can accurately predict ESCA prognosis, we evaluated the predictive value and molecular mechanisms of ARGs in ESCA and constructed an optimal model for prognostic prediction. Using the Cancer Genome Atlas (TCGA)-ESCA database, we identified ARGs with differences in ESCA. ARG signatures were generated using Cox regression. A predictive nomogram model was developed to forecast ARG signatures and patient outcomes in ESCA. Gene set enrichment analysis (GSEA) was employed to uncover potential biological pathways associated with ARG signatures. Estimation of stromal and immune cells in malignant tumor tissues using expression data (ESTIMATE) and cell-type identification by estimating relative subsets of RNA transcripts analyses were used to assess differences in the immune microenvironment of the ARG signature model. Based on ARGs, the patients with ESCA were divided into high and low groups, and the sensitivity of patients to drugs in the database of genomics of drug sensitivity in cancer was analyzed. Finally, the correlation between drug sensitivity and risk score was then evaluated based on the ARG signatures. Prognostic relevance was significantly linked to the ARG profiles of 5 genes: MYB binding protein 1a (MYBBP1A), plasminogen activator, urokinase (PLAU), budding uninhibited by benzimidazoles 3, HOX transcript antisense RNA, and euchromatic histone-lysine methyltransferase 2 (EHMT2). Using the risk score as an independent prognostic factor combined with clinicopathological features, the nomogram accurately predicted the overall survival (OS) of individual patients with ESCA. Gene ontology (GO) enrichment analysis indicated that the primary molecular roles included histone methyltransferase function, binding to C2H2 zinc finger domains, and histone-lysine N-methyltransferase activity. GSEA revealed that the high-risk cohort was connected to cytokine-cytokine receptor interaction, graft-versus-host disease, and hematopoietic cell lineage, whereas the low-risk cohort was related to arachidonic acid metabolism, drug metabolism via cytochrome P450 and fatty acid metabolism. Drug sensitivity tests showed that 16 drugs were positively correlated, and 3 drugs were negatively correlated with ARG characteristic scores. Our study developed 5 ARG signatures as biomarkers for patients with ESCA, providing an important reference for the individualized treatment of this disease.

Ex vivo venetoclax sensitivity predicts clinical response in acute myeloid leukemia in the prospective VenEx trial

AbstractThe BCL2 inhibitor venetoclax has shown promise for treating acute myeloid leukemia (AML). However, identifying patients likely to respond remains a challenge, especially for those with relapsed/refractory (R/R) disease. We evaluated the utility of ex vivo venetoclax sensitivity testing to predict treatment responses to venetoclax-azacitidine in a prospective, multicenter, phase 2 trial conducted by the Finnish AML Group (VenEx, NCT04267081). The trial recruited 104 participants with previously untreated (n = 48), R/R (n = 39), or previously treated secondary AML (sAML) (n = 17). The primary end point was complete remission or complete remission with incomplete hematologic recovery (CR/CRi) rate in ex vivo sensitive trial participants during the first 3 therapy cycles. The key secondary end points included the correlations between ex vivo drug sensitivity, responses, and survival. Venetoclax sensitivity was successfully assessed in 102 of 104 participants, with results available within a median of 3 days from sampling. In previously untreated AML, ex vivo sensitivity corresponded to an 85% (34/40) CR/CRi rate, with a median overall survival (OS) of 28.7 months, compared with 5.5 months for ex vivo resistant patients (P = .002). For R/R/sAML, ex vivo sensitivity resulted in a 62% CR/CRi rate (21/34) and median OS of 9.7 versus 3.3 months for ex vivo resistant patients (P < .001). In univariate and multivariate analysis, ex vivo venetoclax sensitivity was the strongest predictor for a favorable treatment response and survival. The VenEx trial demonstrates the feasibility of integrating ex vivo drug testing into clinical practice to identify patients with AML, particularly in the R/R setting, who benefit from venetoclax.

A Highly Sensitive Test System for Measuring the Phenolic Index of Wastewater Based on a Biocompatible Composite Material with Carbon Nanotubes

A Highly Sensitive Test System for Measuring the Phenolic Index of Wastewater Based on a Biocompatible Composite Material with Carbon Nanotubes

Causal Relationship Between Gastroesophageal Reflux Disease and the Risk of Chronic Rhinosinusitis: Insights from Multivariable and Mediation Mendelian Randomization Analysis.

Background: Previous studies have shown an association between chronic rhinosinusitis (CRS) and gastroesophageal reflux disease (GERD). However, the findings of these studies are controversial, and evaluating this association could help in the treatment of CRS. Thus, we aimed to clarify the relationship between GERD and CRS. Methods: We conducted a Mendelian randomization (MR) study. Pooled data on CRS, GERD, and their associated risk factors were extracted from large genome-wide association studies. Independent single-nucleotide polymorphisms were rigorously screened as instrumental variables. Causal associations between GERD and CRS were assessed, and mediation analyses were performed using multivariate and 2-step MR. Asthma served as a mediator because of its association with both CRS and GERD. Sensitivity tests were also performed. Results: MR analysis showed that genetically predicted GERD was associated with an increased risk of CRS (P < .001). Multivariate MR analysis showed that the effect of GERD on CRS was relatively independent. Mediation analysis showed that asthma mediated the association with a mediation effect of 21.07% (95% CI, 2.70%-40.18%). Sensitivity analyses did not reveal any significant effects of pleiotropy and heterogeneity. Conclusions: We found a causal relationship between genetically predicted GERD and an increase in the risk of CRS. As a mediator, asthma contributed to the effect of GERD on CRS. This study provides high-quality causal evidence for the prevention of CRS.

Discovery of clinical isolation of drug-resistant Klebsiella pneumoniae with overexpression of OqxB efflux pump as the decisive drug resistance factor.

Background emergence of multidrug-resistant (MDR) bacterial strains is a public health concern that threatens global and regional security. Efflux pump-overexpressing MDR strains from clinical isolates are the best subjects for studying the mechanisms of MDR caused by bacterial efflux pumps. A Klebsiella pneumoniae strain overexpressing the OqxB-only efflux pump was screened from a clinical strain library to explore reverse OqxB-mediated bacterial resistance strategies. We identified non-repetitive clinical isolated K. pneumoniae strains using a matrix-assisted laser desorption/ionization time-of-flight (TOF) mass spectrometry clinical TOF-II (Clin-TOF-II) and susceptibility test screening against levofloxacin and ciprofloxacin. And the polymorphism analysis was conducted using pulsed-field gel electrophoresis. Efflux pump function of resistant strains is obtained by combined drug sensitivity test of phenylalanine-arginine beta-naphthylamide (PaβN, an efflux pump inhibitor) and detection with ethidium bromide as an indicator. The quantitative reverse transcription PCR was performed to assess whether the oqxB gene was overexpressed in K. pneumoniae isolates. Additional analyses assessed whether the oqxB gene was overexpressed in K. pneumoniae isolates and gene knockout and complementation strains were constructed. The binding mode of PaβN with OqxB was determined using molecular docking modeling. Among the clinical quinolone-resistant K. pneumoniae strains, one mediates resistance almost exclusively through the overexpression of the resistance-nodulation-division efflux pump, OqxB. Crystal structure of OqxB has been reported recently by N. Bharatham, P. Bhowmik, M. Aoki, U. Okada et al. (Nat Commun 12:5400, 2021, https://doi.org/10.1038/s41467-021-25679-0). The discovery of this strain will contribute to a better understanding of the role of the OqxB transporter in K. pneumoniae and builds on the foundation for addressing the threat posed by quinolone resistance.IMPORTANCEThe emergence of antimicrobial resistance is a growing and significant health concern, particularly in the context of K. pneumoniae infections. The upregulation of efflux pump systems is a key factor that contributes to this resistance. Our results indicated that the K. pneumoniae strain GN 172867 exhibited a higher oqxB gene expression compared to the reference strain ATCC 43816. Deletion of oqxB led a decrease in the minimum inhibitory concentration of levofloxacin. Complementation with oqxB rescued antibiotic resistance in the oqxB mutant strain. We demonstrated that the overexpression of the OqxB efflux pump plays an important role in quinolone resistance. The discovery of strain GN 172867 will contribute to a better understanding of the role of the OqxB transporter in K. pneumoniae and promotes further study of antimicrobial resistance.

Screening of Sensorial and Inflammatory Changes in Patients Submitted to Orthognathic Surgery.

Despite the high levels of success after orthognathic surgery, the immediate postoperative pain and edema, besides the neurosensorial deficits, are common complications. This study aimed to evaluate the pattern of sensory and inflammatory responses in patients undergoing orthognathic surgery. This prospective observational study included 20 patients undergoing bimaxillary orthognathic surgery, who were evaluated in the preoperative period and on Days 1, 2, 3, 4, 5, 6, 7, and 30 after surgery, using a battery of tests to assess sensorial and inflammatory changes. Subjective and objective evaluations of edema indicated a trend toward edema resolution within 30 days, with a significant decrease in mouth opening on days 1, 7, and 30 after surgery. Regarding nasal obstruction, a significant increase in Nasal Obstruction Symptom Evaluation (NOSE) scores was demonstrated on the first, second, and third days, returning to preoperative levels after 30 days. There was a significant increase in visual analogic scale (VAS) scores from the first to the seventh day after surgery, with a reduction within 30 days. For mechanical and thermal sensitivity tests, the lower lip and chin regions had poorer results, without recovery after 30 days. Positive correlations were observed between painful and inflammatory parameters, as well as between subjective and objective evaluations. Analysis of saliva biomarkers did not show significant differences for pre- and postoperative CCL3 or CCL4 levels. Data provide new evidence about the early inflammatory and sensorial complications after orthognathic surgery.

A probabilistic framework for identifying anomalies in urban air quality data.

Just as the value of crude oil is unlocked through refining, the true potential of air quality data is realized through systematic processing, analysis, and application. This refined data is critical for making informed decisions that may protect health and the environment. Perhaps ground-based air quality monitoring data often face quality control issues, notably outliers. The outliers in air quality data are reported as error and event-based. The error-based outliers are due to instrument failure, self-calibration, sensor drift over time, and the event based focused on the sudden change in meteorological conditions. The event-based outliers are meaningful while error-based outliers are noise that needs to be eliminated and replaced post-detection. In this study, we address error-based outlier detection in air quality data, particularly targeting particulate pollutants (PM2.5 and PM10) across various monitoring sites in Delhi. Our research specifically examines data from sites with less than 5% missing values and identifies four distinct types of error-based outliers: extreme values due to measurement errors, consecutive constant readings and low variance due to instrument malfunction, periodic outliers from self-calibration exceptions, and anomalies in the PM2.5/PM10 ratio indicative of issues with the instruments' dryer unit. We developed a robust methodology for outlier detection by fitting a non-linear filter to the data, calculating residuals between observed and predicted values, and then assessing these residuals using a standardized Z-score to determine their probability. Outliers are flagged based on a probability threshold established through sensitivity testing. This approach helps distinguish normal data points from suspicious ones, ensuring the refined quality of data necessary for accurate air quality modeling. This method is essential for improving the reliability of statistical and machine learning models that depend on high-quality environmental data.

B-038 A Novel Ultrasensitive Single-Molecule Counting Technology for Quantitation of Low Abundance Biomarkers

Abstract Background There is a need for sensitive, robust, and scalable analytical methods for accurate, early detection of disease using less invasive sampling methods. Often, smaller volumes and low marker concentrations present challenges to achieving sufficient sensitivity and accuracy with traditional immunoassay methods. This is particularly the case for measuring markers for Alzheimer's and other neurological diseases in blood, where levels are typically at much lower concentrations than in CSF. Here we introduce a novel ultrasensitive technology for flow-based single molecule detection in an optofluidic chip. We have developed an Ultrasensitive Detection Module (UDM) device and optofluidic cartridge that enable easy integration of this technology into existing immunoassay systems. UDM sensitivity data is shown for three prototype biomarker assays in comparison to the Lumipulse G1200 (Fujirebio Inc., Japan). We also present analytical validation data for three Alzheimer’s Disease plasma biomarker assays developed on a fully automated benchtop analyzer with integrated UDM detector. Methods Ultrasensitive detection is achieved by integrated low-loss waveguide in an optofluidic chip that enables maximal excitation of fluorescent molecules traveling through a narrow fluidic channel. The resulting high-intensity emission is detected as a single digital event, enabling individual molecules to be counted without need for amplification. Fluorescence-based immunoassays were developed for detection with the UDM using high performance monoclonal antibodies and reagents (Fujirebio Inc., Japan). Capture antibodies were immobilized on magnetic particles and detection antibodies conjugated to a fluorescent reporter construct (“reporter-Ab”). Multiple incubation and wash steps were followed by dissociation of immune complexes and separation of reporter-Ab from magnetic particles. Released reporter-Ab molecules were injected into the UDM device for digital detection. Signal to noise performance was evaluated in the UDM using reporter construct alone (no assay), as well as for prototype PSA, IL-6, and TSH assays, to establish baseline performance for analytical sensitivity. Plasma assays for pTau181, Aβ1-40, and Aβ1-42 were developed and optimized for the automated benchtop analyzer and validated for analytical sensitivity (LOD/LOQ), linearity, parallelism, precision and repeatability using clinical samples. Results Detection signal-to-noise testing of the reporter construct alone (no immunoassay) demonstrated up to 1000-fold higher sensitivity than the Lumipulse G1200. Prototype assays for PSA, TSH, and IL-6 showed up to 118-fold, 36-fold, and 80-fold higher signal to noise ratio, respectively, when compared to the Lumipulse G1200. Plasma assays for pTau181, Aβ1-40, and Aβ1-42 showed preliminary LLOQs calculated at 0.03 pg/mL, 0.17 pg/mL and 0.37 pg/mL, respectively. Conclusions We have developed a new single molecule counting platform able to detect neurological biomarkers at sub-pg/ml levels in plasma, with the potential to provide sensitive and accurate diagnostic testing of low abundance biomarkers in blood. Such technologies can create new clinical value through higher detection sensitivity and accuracy in areas like Alzheimer’s and other neurological diseases, supporting clinical research and translation to clinical practice.

A-299 Assessment of a new miniaturized line blot system for fully automated serodiagnosis of Borrelia infections

Abstract Background Serodiagnosis of Lyme disease caused by Borrelia burgdorferi commonly affords the combination of a sensitive antibody screening test followed by confirmatory immunoblot analysis. We developed and evaluated a new immunoblot system enabling the multiparametric analysis of anti-Borrelia antibodies by means of miniaturized line blots in a fully automated microplate format. Methods The EUROMicroblots Anti-Borrelia (IgG and IgM, EUROIMMUN) are based on diagnostically relevant Borrelia-specific antigens. Diagnostic sensitivity was determined by analyzing 203 pre-characterized samples from patients with Lyme disease stratified by clinical picture and antibiotic treatment. Specificity was assessed using 168 sera from patients clinically diagnosed with rheumatic diseases. The reference range was analyzed using a control panel of 211 (IgG) and 210 (IgM) samples from healthy individuals, comprising 151 (IgG) and 150 (IgM) blood donors as well as 60 pregnant women (IgG, IgM). The Microwell Imager and EUROLineScan software (EUROIMMUN) were used for image acquisition and evaluation. Results Depending on the clinical category, the diagnostic sensitivity of the EUROMicroblots ranged from 68.0% in the early phase of infection to 100% (IgG/IgM combined) at a specificity of 86.9% (IgG) and 94.0% (IgM). The analysis of the panel of healthy control subjects revealed a prevalence of 10.9% (IgG) and 2.8% (IgM). Conclusions The new EUROMicroblot system enables high-throughput serodiagnosis of Borrelia infections due to the microplate format and automated processing and evaluation. Depending on clinical symptoms and treatment, the assays provide excellent diagnostic sensitivity and specificity for the detection of anti-Borrelia IgG and IgM.

B-227 Customized molecular tests for minimal residual disease: a tool for therapeutic decisions in follicular lymphoma patients

Abstract Background Monitoring of minimal residual disease (MRD) is based on accurate laboratory tests which can recognize a small fraction of malignant cells that survived the course of treatment. Several studies of the B-non-Hodgkin lymphoma group have been presented that MRD positivity at the end of treatment is a negative prognostic index. Follicular lymphoma (FL) is a chronic indolent malignancy, which response highly to immuno-chemotherapy followed by prolonged remissions but with inevitable relapse in most patients. The GALLIUM study showed that immuno-chemotherapy combinations, 6 cycles of bendamustine-obinutuzumab (BO), is the most efficacious treatment, but with severe side effects .In addition, 90% of patients achieved negative MRD from peripheral blood (PB) or bone marrow (BM) after only 3 BO cycles. These findings raise the possibility for MRD based treatment approach, where the duration of chemotherapy could be decided according to MRD status at mid-induction (MI). Identification of a marker in the PB and/or BM of each FL patient which will be use to the design of a sensitive RQ-PCR test for MRD detection for follow-up. Methods Qualitative PCR for translocation 14:18 and for the VDJ rearrangement sequence of the immunoglobulin heavy chain was used for marker identification. MRD monitoring was done by RQ-PCR. MRD monitoring for VDJ was designed specifically to each patients based on his VDJ sequence. MRD was assessed on PB and BM at MI. Results Marker for monitoring was identified at 11/21 patients in this study. After 3 combined therapy cycles, 7 patients were found to have MRD negativity by RQ-PCR therefore continue with immuno-therapy only. MRD positivity was assessed in BM of 3 patients (0.11%, 0.022%, and 0.133%). These 3 patients continued with the combined therapy. RQ-PCR sensitivity was 10-4-10-5. Conclusions This study will reveal the ability to use sensitive and specific MRD that has to be designed for each patient according to his marker and enable the establishment of a treatment with a high safety profile for FL patients. Correlation between MRD status and clinical and safety parameters will be assessed at the end of the study, 30 months after the first treatment, taking into account MRD status from different time point of the follow-up period.