Chemiluminescence Method Research Articles

Establishment of a Chemiluminescent ELISA Method for Florfenicol in Eggs and Chicken Meat

Establishment of a Chemiluminescent ELISA Method for Florfenicol in Eggs and Chicken Meat

9303 Evaluation of The Consistency of Thyroid Indicators Tests in Minimally Invasive Peripheral Blood and Venous Blood

Abstract Disclosure: Z. Zhu: None. Y. Huang: None. Z. Cao: None. L. Zhang: None. D. Wang: None. S. Wang: None. J. Zhang: None. Y. Gao: None. Y. Zhang: None. Background The detection of thyroid indicators is of high demand in clinical and epidemiological screenings. Compared with existing venous blood tests, peripheral fingertip blood tests are less invasive and have a lower blood collection volume, which is the basis for point-of-care tests of thyroid indicators. Objective To explore the feasibility of minimally invasive and micro blood collection tests for thyroid disease (TD) patients by evaluating the consistency of thyroid indicators and TD diagnostic efficiency between fingertip blood tests and venous blood tests. Method 63 subjects with or without thyroid dysfunction were consecutively recruited. All subjects underwent serum, plasma and fingertip blood (same day collection) measurements for TSH and TT4 detection via the chemiluminescence method and for TPOAb detection via the electrochemiluminescence immunoassay method. The fingertip blood was centrifuged and diluted after EDTA anticoagulation. Bland–Altman plot, Passing–Bablok regression, and weighted kappa test were used for consistency test; AUC of ROC curve, sensitivity and specificity were used for authenticity evaluation among the three collection and testing methods. Results 43 subjects with euthyroidism and 20 subjects with thyroid dysfunction were included; including 29 (46.03%) females, the average age was 50.98±14.76 years. Bland-Altman plots showed more than 90% of the subjects had TSH and TT4 differences within the 95% limits of agreement between peripheral blood (PB) and venous blood (including serum and plasma). Passing–Bablok regression analyses revealed strong correlations between TSH levels in PB and serum (r=0.888) and plasma (r=0.894) (p<0.05); for TT4, there was a strong correlation between PB and serum (r=0.746), and there was also a moderate correlation between PB and plasma (r=0.664) (p<0.05 for both). Weighted kappa tests were performed for low, normal and high TSH values, indicating strong consistency between PB and serum and between PB and plasma, with coefficients of 0.901 and 0.881, respectively (P<0.001); for TT4, the coefficients between PB and serum, PB and plasma were 0.541 and 0.585 (P<0.001), indicating moderate consistency. Regardless of TPOAb positivity or negativity, the consistency among three blood sample sources was 100%. For euthyroidism (n=43), hyperthyroidism (n=6), subclinical hyperthyroidism (n=9), hypothyroidism (n=1), and subclinical hypothyroidism (n=4), the diagnostic sensitivities of PB were 97.06%, 83.33%, 87.50%, 100%, and 75.00%, respectively; the specificities were 94.74%, 97.87%, 95.74%, 98.11%, and 100.00%, respectively. The AUC of PB ROC curve for determining thyroid dysfunction was 0.944 (95% CI 0.867-1.000). Conclusion PB tests of thyroid indicators has high consistency with venous blood tests, offers sufficient diagnostic efficiency for TD, and is a feasible minimally invasive detection method. Presentation: 6/1/2024

7583 Evaluation of The Consistency of Thyroid Indicators Tests in Minimally Invasive Peripheral Blood and Venous Blood

Abstract Disclosure: Z. Zhu: None. Y. Huang: None. Z. Cao: None. L. Zhang: None. D. Wang: None. S. Wang: None. J. Zhang: None. Y. Gao: None. Y. Zhang: None. Background: The detection of thyroid indicators is of high demand in clinical and epidemiological screenings. Compared with existing venous blood tests, peripheral fingertip blood tests are less invasive and have a lower blood collection volume, which is the basis for point-of-care tests of thyroid indicators. Objective To explore the feasibility of minimally invasive and micro blood collection tests for thyroid disease (TD) patients by evaluating the consistency of thyroid indicators and TD diagnostic efficiency between fingertip blood tests and venous blood tests. Method 63 subjects with or without thyroid dysfunction were consecutively recruited. All subjects underwent serum, plasma and fingertip blood (same day collection) measurements for TSH and TT4 detection via the chemiluminescence method and for TPOAb detection via the electrochemiluminescence immunoassay method. The fingertip blood was centrifuged and diluted after EDTA anticoagulation. Bland–Altman plot, Passing–Bablok regression, and weighted kappa test were used for consistency test; AUC of ROC curve, sensitivity and specificity were used for authenticity evaluation among the three collection and testing methods. Results 43 subjects with euthyroidism and 20 subjects with thyroid dysfunction were included; including 29 (46.03%) females, the average age was 50.98±14.76 years. Bland-Altman plots showed more than 90% of the subjects had TSH and TT4 differences within the 95% limits of agreement between peripheral blood (PB) and venous blood (including serum and plasma). Passing–Bablok regression analyses revealed strong correlations between TSH levels in PB and serum (r=0.888) and plasma (r=0.894) (p<0.05); for TT4, there was a strong correlation between PB and serum (r=0.746), and there was also a moderate correlation between PB and plasma (r=0.664) (p<0.05 for both). Weighted kappa tests were performed for low, normal and high TSH values, indicating strong consistency between PB and serum and between PB and plasma, with coefficients of 0.901 and 0.881, respectively (P<0.001); for TT4, the coefficients between PB and serum, PB and plasma were 0.541 and 0.585 (P<0.001), indicating moderate consistency. Regardless of TPOAb positivity or negativity, the consistency among three blood sample sources was 100%. For euthyroidism (n=43), hyperthyroidism (n=6), subclinical hyperthyroidism (n=9), hypothyroidism (n=1), and subclinical hypothyroidism (n=4), the diagnostic sensitivities of PB were 97.06%, 83.33%, 87.50%, 100%, and 75.00%, respectively; the specificities were 94.74%, 97.87%, 95.74%, 98.11%, and 100.00%, respectively. The AUC of PB ROC curve for determining thyroid dysfunction was 0.944 (95% CI 0.867-1.000). Conclusion PB tests of thyroid indicators has high consistency with venous blood tests, offers sufficient diagnostic efficiency for TD, and is a feasible minimally invasive detection method. Presentation: 6/1/2024

Predictive Significance of Combined Plasmatic Detection of BRAF Mutations and S100B Tumor Marker in Early-Stage Malignant Melanoma.

Melanoma is the most aggressive skin cancer with ability to recur also after early-stage tumor surgery. The aim was to identify early-stage melanoma patients at high risk of recurrence using liquid biopsy, estimating of mutated BRAF ctDNA and the level of tumor marker S100B in plasma. Eighty patients were enrolled in the study. BRAF V600E mutation was determined in FFPE tissue and plasma samples using ultrasensitive ddPCR with pre-amplification. The level of S100B was determined in plasma by immunoassay chemiluminescent method. The best prediction of melanoma recurrence after surgery was observed in patients with combined high level of S100B (S100Bhigh) and ctDNA BRAFV600E (BRAFmut) in preoperative (57.1% vs. 12.5%, p = 0.025) as well as postoperative blood samples (83.3% vs. 14.3%, resp., p = 0.001) in comparison with low S100B and BRAF wild-type. Similarly, patients with preoperative and postoperative S100Bhigh and BRAFmut experienced worse prognosis (DFI p = 0.05, OS p = 0.131 and DFI p = 0.001, OS = 0.001, resp.). We observed the benefit of the estimation of combination of S100B and ctDNA BRAFmut in peripheral blood for identification of patients at high risk of recurrence and unfavorable prognosis. There is still no general consensus on molecular markers for deciding the appropriateness of adjuvant treatment of early-stage melanoma. We have shown for the first time that the combined determination of the ctDNA BRAFmut oncogene (liquid biopsy) and the high level of tumor marker S100B in pre- and postoperative plasma samples can identify patients with the worst prognosis and the highest risk of tumor recurrence. Therefore, modern adjuvant therapy would be appropriate for these patients with resectable melanoma, regardless of disease stage.

Clinical and pathogenetic significance of the phenomenon of functional heterogeneity of oxygen-dependent functions of neutrophils in ankylosing spondylitis

Neutrophils are able to exert a variety of effects on other cells of the immune system, which indicates their heterogeneity. In various rheumatic diseases, neutrophils are involved in the immunopathological process. The study of the phenomenon of functional heterogeneity of neutrophils associated with the pathogenesis of rheumatic diseases is a promising area of research in immunology and rheumatology. The purpose of the research: study of factors influencing oxygen-dependent neutrophil functions in ankylosing spondylitis (AS). A total of 82 patients with AS were examined. The functional activity of neutrophils was assessed according to the data of determining the indicators of oxygen-dependent functions by the chemiluminescence method. Functional neutrophil reserve (FNR) was assessed by activation coefficients (the ratio of chemiluminescence induced by suspension of heat-killed staphylococcus cells to spontaneous value). Statistical data processing was carried out using Statistica 10.0 program. An increase in oxygen-dependent neutrophil functions in AS was accompanied by an increase in disease activity. The greatest influence on the increase in the functional activity of cells was exerted by the age of patients, the stage of the disease and the level of circulating immune complexes. The process of stabilizing the metabolic activity of neutrophils was significantly influenced by the age of patients, ESR, ã-globulins, total cholesterol, and low-density lipoprotein cholesterol. Among the laboratory parameters, the majority of AS patients with moderate and high FNR had elevated levels of ESR, CRP, and IgM; there was a tendency to increase IgA in AS patients with high FNR. Statistical analyses showed an association between FNR and disease activity; there was no statistically significant dependence of FNR on the stage, course, and form of AS. The study of the metabolic activity of neutrophils during dynamic observation revealed a group of patients with stabilization of FNR parameters against the background of therapy with the achievement of a normal level of oxygen-dependent metabolism. Thus, in ankylosing spondylitis, the functional heterogeneity of neutrophils associated with disease activity was established according to the determination of oxygen-dependent metabolism.

Magnetic nanoparticle-decorated metal organic frameworks for chemiluminescence detection of glutathione.

A chemiluminescence (CL) method for determination of glutathione (GSH) was developed with magnetic nanoparticle-decorated metal organic frameworks (Fe3O4 NPs@Cu-TATB). The composite material was synthesized via a hydrothermal method and glutathione (GSH) can be detected by both visual and chemiluminescence (CL) methods. The synthesized Fe3O4 NPs@Cu-TATB exhibited excellent catalytic activity in the luminol-H2O2 CL system. The mechanism revealed that three types of oxygen-containing radicals (ROS) were generated in this system. As GSH can reduce the catalytic effect of generated ROS radicals, the inhibiting CL signal was produced in the Fe3O4 NPs@Cu-TATB-luminol-H2O2 system. Based on the established CL system, the detection limits for GSH using CL and visual methods were found to be 0.3 µM and 0.7 µM, respectively. This low-cost and convenient detection method can be applied to the determination of GSH content in human blood.

Seasonal variation of total and bioavailable 25-hydroxyvitamin D [25(OH)D] in the healthy adult Slovenian population.

Objective: The aim of our study was to compare the total 25(OH)D fraction, the bioavailable vitamin fraction, and the free vitamin D fraction in spring and fall in a group of healthy individuals. Methods: In our study, we collected blood samples from healthy participants at the end of both summer and winter, and measured serum levels of albumin, DBP, and 25(OH)D. Utilizing these data, we calculated the percentage of free and bioavailable vitamin D. Our cohort comprised 87 participants, with a male-to-female ratio of 14:73, aged 35.95 ± 12.55years, ranging from 19 to 70years. We employed the chemiluminescence method to determine the vitamin 25(OH)D levels, the ELISA method was utilized to determine DBP levels, the albumin BCP Assay was performed using the ADVIA biochemical analyzer (Siemens) and an online calculator was used to determine the free and bioavailable 25(OH)D levels. Results: Our findings indicate significantly lower 25(OH)D levels in winter (44.13 ± 17.82nmol/L) compared to summer (74.97 ± 22.75nmol/L; p < 0.001). For vitamin D binding protein there was no significant difference from summer (236.2 ± 164.39mg/L) to winter (239.86 ± 141.9mg/L; p = 0.77), albumin levels were significantly higher in summer (49.37 ± 4.15g/L vs. 47.97 ± 3.91g/L, p = 0.01), but the magnitude of the change may not be large enough to be solely responsible for the stability of vitamin D levels throughout the year. In the winter season a significantly lower calculated bioavailable 25(OH)D vitamin (7.45 ± 5.66nmol/L against 13.11 ± 8.27nmol/L; p < 0.001) was observed, and the free fraction also showed a significant decrease (17.3 ± 12.9pmol/L versus 29.7 ± 19.1pmol/L; p < 0.0001). We observed a moderately positive correlation between 25(OH)D and bioavailable percentage in winter (r = 0.680; p < 0.001), in contrast with a lower positive association in summer (r = 0.343; p < 0.001). Conclusion: Our data suggest a positive correlation between total and bioavailable 25(OH)D levels. In addition to the statistically significant variation in 25(OH)D between the two observation periods, there was an additional variation in the free vitamin D percentage. The summertime synthesis of vitamin D in the skin could contribute directly to the free fraction of vitamin D. Standardizing the measurement of free 25(OH)D and clinical studies is necessary to establish reference values before these methods can be implemented in clinical practice.

Combining High-Resolution Mass Spectrometry and Chemiluminescence Analysis to Characterize the Composition and Fate of Total N-Nitrosamines in Wastewater Treatment Plants.

Monitoring the prevalence and persistence of N-nitrosamines and their precursors in wastewater treatment plants (WWTPs) and effluent-receiving aquatic compartments is a priority for utilities practicing wastewater recycling or exploiting wastewater-impacted source waters. In this work, we developed an analytical framework that combines liquid chromatography-high-resolution mass spectrometry (LC-HRMS) with acidic triiodide-chemiluminescence analysis to characterize the composition and fate of total N-nitrosamines (TONO) and their precursors along the treatment trains of eight WWTPs in New York. Through the parallel application of LC-HRMS and chemiluminescence methods, the TONO scores for 41 N-nitrosamines containing structurally diverse substituents on their amine nitrogen were derived based on their solid-phase extraction recoveries and conversion efficiencies to nitric oxide. Correcting the compositional analysis of TONO using the TONO scores of target N-nitrosamines refined the assessment of the reduction or accumulation of TONO and their precursors across treatment steps in WWTPs. Nontargeted analysis prioritized seven additional N-nitrosamines for confirmation by reference standards, including three previously uncharacterized species: N-nitroso-tert-butylphenylamine, N-nitroso-2-pyrrolidinmethanol, and N-nitrosodesloratadine, although they only served as minor components of TONO. Overall, our study establishes an adaptable methodological framework for advancing the quantitative and qualitative analysis of specific and unknown components of TONO across water treatment and reuse scenarios.

Enhanced Differentiation of Amiodarone-Induced Thyrotoxicosis Types Using Semi-Quantitative 99mTc-MIBI Uptake Analysis: A Pilot Study.

BACKGROUND Technetium (99mTc)-labelled Methoxy-2-Isobutylisonitrile (MIBI) is a diagnostic lipophilic cationic radiotracer used to evaluate the cardiac, breast, thyroid, and parathyroid pathology. This study aimed to evaluate the role of MIBI combined with Tc-99m pertechnetate thyroid scintigraphy, thyroid ultrasonography, and measurement of thyrotropin, thyroid hormones, and autoantibodies to subtype amiodarone-induced thyrotoxicosis (AIT) and the contribution of semi-quantitative analysis of MIBI uptake. MATERIAL AND METHODS This cross-sectional study included 36 patients with AIT who underwent thyrotropin, thyroid hormone, and autoantibody analysis using chemiluminescent method, ultrasonography, pertechnetate, and MIBI thyroid scintigraphy with semi-quantitative uptake, including calculation of the target-to-background ratio (TBR) with 2 different background regions. The MIBI washout rate (WR) was analyzed in all groups. Statistical analysis was performed using descriptive statistics, correlations, and the receiver operating characteristic curve - area under the curve (ROC-AUC). The results were compared with the control group. RESULTS Based on visual and semi-quantitative analyses, patients were successfully categorized into AIT groups (AIT-1, AIT-2 and AIT-3) but the latter method enabled better differentiation of MIBI uptake between all groups. Additionally, ROC-AUC analysis determined cutoff values which enabled discerning between AIT-1 and AIT-2 groups, and AIT-1 and AIT-3 groups. WR showed no significant difference between all AIT groups and controls (P>0.05). CONCLUSIONS Visual MIBI analysis enabled differentiation between AIT-1 and 2 groups, but the method was substantially improved with semi-quantitative analysis, especially in defining AIT-3 group. However, multicenter collaboration with larger studies is needed to standardize the method and obtain more accurate and consistent results.

Iridium(III) solvent complex-based electrogenerated chemiluminescence method for the detection of 3-methylhistidine in urine.

3-Methylhistidine (3-MeHis) is increasingly used as an indicator of muscle protein breakdown. The development of asensitive, simple, and non-invasive method for 3-MeHis assay is important in clinical practice. Herein, a sensitive, simple, and non-invasive electrogenerated chemiluminescence (ECL) method was proposed for the quantitation of 3-MeHis in urine by using an iridium(III) solvent complex ([Ir(dfppy)2(DMSO)Cl], dfppy = 2-(2,4-difluorophenyl)pyridine, Ir-DMSO) as a signal reagent. The photoluminescence (PL) and ECL responses of Ir-DMSO to 3-MeHis were studied. The ECL intensity of Ir-DMSO was enhanced in the presence of 3-MeHis because of the coordination recognition between Ir-DMSO and the imidazole group of 3-MeHis. Based on the enhancement of ECL intensity, 3-MeHis can be sensitively detected in the range of 5 to 25μM. The detection limit was 0.4μM. This is the first report of an ECL method for the quantitation of 3-MeHis. Further, to investigate the feasibility of the Ir-DMSO-based ECL method in practical applications, the developed ECL method was applied for 3-MeHis assay in urine samples of 28 healthy volunteers and 2 patients. The urine samples from patients hospitalized with obesity and kidney disease and healthy individuals were distinguished by the ECL responses of Ir-DMSO. The proposed ECL method based on the coordination recognition between iridium(III) solvent complex and the imidazole group of 3-MeHis allows inexpensive, fast, non-invasive, and sensitive detection of 3-MeHis in urine, which is promising for assessing large volumes of patients for routine analysis in clinical practices.

Association of MTHFR C677T, MTHFRA1298C, and MTRRA66G Gene Polymorphisms with Hyperhomocysteinemia and Its Modulation by the Combined Effect of Vitamin B12 and Folate in Chinese Population with Hypertension

BackgroundIn China, the MTHFR 677T allele, unlike in most Western populations, is a rare genetic variant linked to various disorders. The contributing nutritional and genetic factors to this genetic risk remain unclear. ObjectiveThis study aimed to elucidate the interactions between genetic variations in total homocysteine (tHcy) pathway genes, serum tHcy concentrations, and nutritional factors in a Chinese population with hypertension. MethodsThis study analyzed 1304 Chinese adults with hypertension aged ≥18 y enrolled in the China Precision Nutrition and Health KAP Real World Study (CPNAS). Serum concentrations of vitamin B12 and folate were measured using the magnetic microparticle chemiluminescence method, and tHcy concentrations were measured using Hcy Assay kits. Identification of the MTHFR C677T, MTHFR A1298C, and MTRR A66G polymorphisms was performed via time-of-flight nucleic spectrometry. ResultsOur findings revealed significant sex differences in tHcy concentrations, with males exhibiting higher tHcy concentrations than females (13.95 μmol/L vs. 11.15 μmol/L, P < 0.001). Individuals deficient in both vitamin B12 and folate had an increased risk of hyperhomocysteinemia (H-Hcy) (57.4%). In contrast, the prevalence of H-Hcy was lower among those deficient in either vitamin B12 (31.1%) or folate (23.2%) alone. Significant associations were identified between the MTHFR C677T and A1298C polymorphisms and elevated serum tHcy concentrations, particularly in individuals homozygous for the T allele. Conversely, the MTRR A66G genotype did not show a significant correlation with tHcy concentrations. Optimal vitamin B12 concentrations significantly modulated the genotypic effect on tHcy concentrations, with individuals having adequate vitamin B12 and folate exhibiting low tHcy concentrations, even among high-risk genotypes (TT). ConclusionsAdequate concentrations of folate and vitamin B12 significantly reduce serum tHcy concentrations and mitigate the genotypic impact on tHcy concentrations, highlighting the potential for targeted nutritional interventions to manage cardiovascular risks associated with H-Hcy.This trial was registered at clinicaltrials.gov as ChiCTR2100051983.

The value of amide proton transfer imaging combined with serum CA125 levels in predicting lymph vascular invasion in cervical cancer before surgery.

Preoperative prediction of lymphovascular space invasion (LVSI) is crucial for improving the prognosis of patients with cervical cancer. To evaluate the value of preoperative amide proton transfer (APT) imaging combined with serum CA125 levels for predicting LVSI in cervical cancer. This retrospective study included 80 patients with cervical cancer who underwent preoperative magnetic resonance imaging, including APT imaging. Serum CA125 levels were measured using a fully automated immunoassay analyzer and chemiluminescence method. The presence of LVSI was determined based on the pathological results after surgery. Among the 40 patients who met the requirements, 29 had postoperative pathological confirmation of LVSI, while 11 did not. The areas under the receiver operating characteristic curves (AUC) of preoperative APT and CA125 levels predicting LVSI were 0.889 and 0.687, respectively. When the APT value was 2.9%, the corresponding Youden index was the highest (0.702), with a sensitivity of 79.3% and specificity of 90.9%. When the critical value of the preoperative serum CA15 level was 25.3 u/mL, the corresponding Youden index was the highest (0.508), with a sensitivity of 69.0% and a specificity of 81.8%. The sensitivity and specificity of preoperative APT imaging combined with serum CA125 in predicting LVSI were 82.7% and 100%, respectively, with a Youden's index of 0.828 and an AUC of 0.923. The combination of preoperative APT imaging and serum CA125 levels is valuable for predicting LVSI in cervical cancer. Diagnostic efficacy is highest when the APT value is >2.9% and the serum CA125 level is >25.3 u/mL.

Hua-Shi-Bai-Du decoction inactivates NLRP3 inflammasome through inhibiting PDE4B in macrophages and ameliorates mouse acute lung injury

BackgroundHua-Shi-Bai-Du decoction (HSBD) exerts significant effects on the prevention and treatment of COVID-19 in China. The activation of the NLRP3 inflammasome of macrophages plays a vital role in COVID-19 pathology. However, no previous studies have focused on this pathological process to explore the effect of HSBD. PurposeOur aim is to uncover the effect of HSBD on NLRP3 inflammasome activation and the underlying mechanisms. MethodsThe NLRP3-activated J774A.1 cells primed by LPS and activated by nigericin/ATP/MSU were used to evaluate NLRP3 activation in vitro. ASC oligomerization and speck formation were assessed by western blot and immunofluorescence imaging. Intracellular K+ levels were determined by the colorimetric assay. Mitochondrial ROS (mtROS) level was detected by the flow cytometry and the fluorescence spectrophotometry. The intracellular cAMP level was determined by chemiluminescence method and ELISA, while phosphodiesterase (PDE) activity was measured using the fluorescent substrate MANT-cAMP. siRNA was applied to knockdown PDE4B. Two in vivo mouse models, MSU-induced peritonitis and LPS-induced acute lung injury (ALI), were used to evaluate the effects of HSBD on IL-1β and other inflammatory cytokines. Pathological changes in lung tissue were observed by histopathological examination. ResultsHSBD not only decreased supernatant IL-1β, caspase-1 p20, and cleaved gasdermin D (GSDMD) in NLRP3-activated J774A.1 cells, but also reduced IL-1β in the peritoneal lavage fluid of mice with MSU-induced peritonitis, demonstrating the suppressive effect on NLRP3 inflammasome activation. The mechanism study showed that HSBD blocked ASC oligomerization and speck formation without affecting K+ efflux or mtROS production. Furthermore, it prevented the decrease of intracellular cAMP by inhibiting PDE4B activity. And in the PDE4B-deficient cells, its suppressive effect on IL-1β release was abolished. In LPS-induced ALI mice, oral administration of HSBD decreased several proinflammatory cytokines (IL-1β, IL-6, TNF-α, and CXCL-1) and attenuated the pathological damage to the lung. ConclusionHSBD suppresses the activation of NLRP3 inflammasome by inhibiting PDE4B activity to counteract the decrease of intracellular cAMP, thereby blocking ASC oligomerization in macrophages. Our findings may provide new insight into the clinical effets of HSBD for the treatment of COVID-19.

Investigation on special reactivity of sulfite as an electron acceptor for the attenuated Fenton reaction and the abatement mechanism

Sulfur(IV) as a ubiquitous substance in the atmosphere and water bodies can be deliberately involved in different redox reactions based on the known ability to donate electrons, but the inhibition effect on the advanced oxidation processes (AOPs) especially the Fenton reaction, which played a vital role in aerosol aging and pollution treatment, still stayed fuzzy. In this work, it was first found that sulfite had an unexpected reactivity to accept electrons from Fe(II) monitored by the chemiluminescence (CL) method to reduce Fe(II) seriously. Dynamics calculation, UV–vis absorption, HPLC, and CL analysis indicated that sulfite anions can be transferred into SO2·- or dimer S2O42- through reacting with Fe(II). The direct consumption of Fe(II) in Fenton reaction only happened by sulfite among other inorganic anions during degrading different organic pollution, and the produced S2O42- showed an overpowering inhibitory ability on hydroxyl radical especially at pH 5.3, both resulting in a strong inhibition effect on the Fenton reaction. In contrast at pH 3.1, the fast depletion of sulfite by H2O2 and decomposition of S2O42- fell off the inhibition effect. Furthermore, abatement experiments showed that the effect of sulfite could be circumvented by using a non-iron-based oxidation system with other metal ions, additionally clarifying the reaction of Fe(II)-sulfite played the primary role in the inhibition. Significantly, this inhibition effect of sulfite on the Fenton reaction was demonstrated to take place both in the natural wastewater and degrading two acids from biomass burning in the atmosphere, identifying the attenuated Fenton reaction in the presence of sulfur(IV) in the environment.

Mechanism of ligustilide in attenuating OGD/R-induced HT22 cell injury based on FtMt inhibition of ferroptosis

This study investigated the role and mechanism of ligustilide(LIG) in attenuating oxygen-glucose deprivation/reoxyge-nation(OGD/R)-induced damage to mouse hippocampal neuron cells(HT22) by inhibiting ferroptosis through mitochondrial ferritin(FtMt). An in vitro model of OGD/R-induced HT22 cell damage was established. HT22 cells were randomly divided into normal group, model group, LIG groups(5, 10, and 20 μmol·L~(-1)), and ferrostatin-1(Fer-1, 2 μmol·L~(-1)) group. Cell viability was mea-sured using the CCK-8 method, and lactate dehydrogenase(LDH) release was measured using an LDH assay kit. Cell morphology was observed under an inverted microscope, and mitochondrial ultrastructure was observed using transmission electron microscopy. Intracellular Fe~(2+) content was detected using a chemiluminescence method. To further investigate the mechanism of FtMt inhibition of ferroptosis, FtMt in HT22 cells was silenced and divided into normal group, model group, LIG group(20 μmol·L~(-1)), si-NC group, si-FtMt group, and si-FtMt+20 μmol·L~(-1) LIG group. Immunofluorescence and Western blot were used to detect FtMt expression. Chemiluminescence was used to measure the content of NADPH/NADP~+, GSH, MDA, and ATP in HT22 cells. The mtROS fluorescence intensity was observed by laser confocal microscopy, and intracellular Fe~(2+) content was measured by flow cytometry. The expression of ferroptosis-related proteins Ferrtin, GPX4, and ACSL4 was detected by Western blot. The results showed that compared with the model group, LIG significantly increased the survival rate of HT22 cells, improved the morphology of damaged HT22 cells and mitochondrial ultrastructure, decreased intracellular Fe~(2+) content, and reduced the expression of the pro-ferroptosis protein ACSL4 while increasing the expression of anti-ferroptosis proteins Ferrtin and GPX4. After silencing FtMt, LIG promoted FtMt expression. Compared with the si-FtMt group, LIG significantly increased the content of NADPH/NADP~+ and GSH, reduced mtROS fluorescence intensity and MDA content, increased ATP activity, decreased intracellular Fe~(2+) content, inhibited the expression of pro-ferroptosis protein ACSL4, and increased the expression of anti-ferroptosis proteins Ferrtin and GPX4. In summary, LIG improved mitochondrial function by upregula-ting FtMt expression to inhibit ferroptosis, thereby alleviating OGD/R-induced damage to HT22 cells.

Probing N-substituted 4-(5-mercapto-4-ethyl-4H-1,2,4-triazol-3-yl)-N-phenylpiperdine-1-carboxamides as potent 15-LOX inhibitors supported with ADME, DFT calculations and molecular docking studies

In our continuous efforts to find out leads against the enzyme 15-lipoxygenase (15-LOX), the current study deals with the synthesis of a series of new N-alkyl/aralkyl/aryl derivatives of 2-(4-ethyl-5-(1-phenylcarbamoyl)piperidine-4H-1,2,4-triazol-3-ylthio)methylacetamide (7a-n) with anti-LOX activities. The synthesis was started by reacting phenylisocyanate with isonipecotate that sequentially converted into N-substituted ester (1), hydrazide (2), semicarbazide (3) and N-ethylated 5-(1-phenylcarbamoyl)piperidine-1,2,4-triazole (4). The final compounds, 7a-n, were obtained by reacting 4 with various N-alkyl/aralkyl/aryl electrophiles. Both the intermediates and target compounds were characterized by FTIR, 1H, 13C NMR spectroscopy, EI-MS and HR-EI-MS spectrometry and screened against soybean 15-LOX by chemiluminescence method. The eight compounds 7e, 7j, 7h, 7a, 7g, 7b, 7n, 7c showed potent inhibitory activities against 15-LOX with values ranging from IC50 0.36 ± 0.15 μM (7e) to IC50 6.75 ± 0.17 μM (7c) compared with the reference quercetin (IC50 4.86 ± 0.14 μM) and baicalein (IC50 2.24 ± 0.13 μM). Two analogues (7l, 7f) had significantly outstanding inhibitory potential with IC50 values 12.15 ± 0.23 μM and 15.54 ± 0.26 μM, whereas, the derivatives 7i, and 7d displayed IC50 values of 21.56 ± 0.27 μM, 23.59 ± 0.24 μM and the compounds 7k, 7m were found inactive. All analogues exhibited blood mononuclear cells (MNCs) viability >75 % at 0.25 mM concentration as determined by MTT method. Calculated pharmacokinetic properties projected good lipophilicity, bioavailability and drug-likeness properties and did not violate Lipinski's/Veber rule. Molecular docking studies revealed lower binding free energies of all the derivatives than the reference compounds. The binding free energies were −9.8 kcal/mol, −9.70 k/mol and −9.20 kcal/mol for 7j, 7h and 7e, respectively, compared with the standard quercetin (−8.47 kcal/mol) and baicalein (−8.98 kcal/mol). The docked ligands formed hydrogen bonds with the amino acid residues Gln598 (7e), Arg260, Val 126 (7h), Gln762, Gln574, Thr443, Arg580 (7j) while other hydrophobic interactions observed therein further stabilized the complexes. The results of density functional theory (DFT) revealed that analogues with more stabilized lower unoccupied molecular orbital (LUMO) had significant enzyme inhibitory activity. The data collectively supports these molecules as leads against 15-LOX and demand further investigations as anti-inflammatory agents.

Chemiluminescence method for evaluating photooxidative degradation of dispensed drugs: a potential new drug information tool

BackgroundDispensed drugs stored by patients are often in single-dose packages (SDPs) or are crushed and mixed after being removed from a press-through package (PTP) sheet. Information on their stability is extremely limited. To address this, we explored using chemiluminescence (CL) measurements to detect oxidative degradation.MethodsEight amlodipine, 14 telmisartan, and two warfarin preparations were used as specimens. These preparations were stored at room temperature under various conditions, after which CL was measured. Cellopoly packaging paper was used for SDP. Three light conditions were used (Condition A: darkness, Condition B: indoor diffused light (approximately 400 lx), and Condition C: exposure to 4,000 lx). CL cumulative light output was measured every minute under nitrogen gas conduction and with a sample chamber temperature of 150 °C, for a maximum of 10 min. Luminescence images were obtained simultaneously with the CL measurements.ResultsCL was observed on light-exposed tablet surfaces. For each preparation, an increase in the CL value was observed with the duration of light exposure. In the same preparation with the same exposure time, CL tended to be higher in the order of Condition A < B < C. Moreover, CL increased even when no changes in color were observed by the naked eye. A comparison between preparations with the same main ingredients showed differences in the rate of increase in CL with exposure, and each was found to show a different reactivity to light.ConclusionsTo the best of our knowledge, this is the first study to visually capture the surface oxidation of tablets exposed to light using the CL method. The CL values, thought to be derived from photooxidation, increased with exposure of tablets and powders to light after SDP. This method can sensitively assess drug degradation due to photooxidation. Further research is needed to establish a CL method for assessing the stability of preparations in clinical settings.

COVID-19 Pandemic: Challenges, Controversies and What we have Learned

Introduction: The COVID-19 pandemic put us in a very difficult situation and created a lot of challenges for both diagnostics and follow-up of patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We also had difficult problems understanding the virus-host interactions and the progression of the immune response. Objectives: We aimed to point out our experience in the diagnostics of SARS-CoV-2 in patients admitted to Fundeni Clinical Institute. We have also investigated the healthcare personnel in order to have some epidemiologic data about the transmission of the new coronavirus in our institute. Methods: Three different real-time reverse transcription-polymerase chain reaction (RT-PCR) assays were used to screen for the new coronavirus infection. The immunization rate against SARS-CoV-2 was detected by assessing the IgG antibodies in both patients and clinical staff. We have used the chemiluminescence method to assess the anti-SARS-CoV-2 IgG antibodies. Results: Most of the diagnosed patients with SARS-CoV-2 infections were admitted to the surgery wards for hematology and gastroenterology. Our data showed that all the diagnosed patients developed IgG antibodies against SARS-CoV-2, but we have noticed that the immunization against SARS-CoV-2 did not last. Conclusions: Our experience with the SARS-CoV-2 pandemic emphasized that molecular diagnostics by RT-PCR was essential, together with the study of IgG antibodies against SARS-CoV-2, thus enabling us to better interpret PCR test results.

VS4 Nanodendrites with Narrow Bandgaps in Activating Dissolved Oxygen for Boosted Chemiluminescence and Hemin Detection by Unexpected Quenching.

Chemiluminescence (CL)-based analytical methods utilize luminophores that need to be activated with an oxidizing agent to trigger CL emission. Despite its susceptibility to decomposition when exposed to external light or trace metals, hydrogen peroxide (H2O2) has been widely used to develop chemiluminescent methods due to the limited number of suitable alternatives for activating chemiluminescent luminophores. Also, analytical methods based on the well-known luminol/H2O2 CL system have low sensitivity. Dissolved oxygen (DO) is a naturally abundant and environmentally benign alternative oxidant for luminol and other CL luminophores. However, DO alone is inactive and needs an efficient catalyst or a coreaction accelerator for its activation. Because of the narrow bandgap of VS4 (ca. 1.12 eV), it can facilitate fast electron-transfer kinetics with an acceptor molecule such as DO. Here, we introduce vanadium tetrasulfide (VS4) to boost CL for the first time. Under the optimized conditions, VS4 nanodendrite catalyzes the generation of reactive oxygen species by activating DO which subsequently reacts with luminol to generate intense CL. It enhances the CL intensity of luminol/DO by about 10,000 times. Surprisingly, hemin remarkably quenches the generated CL of luminol/DO/VS4 nanodendrites, which is completely opposite to its typical enhancement of luminol CL. Based on the remarkable concentration-dependent quenching of the luminol/DO/VS4 nanodendrite CL by hemin, we have developed a sensitive CL method that can selectively detect hemin in the linear concentration range of 1-250 nM and achieved a limit of detection of 0.11 nM. The practical utility of the developed method was demonstrated by the determination of hemin in a pharmaceutical drug for the treatment of acute intermittent porphyria and in human serum. This study demonstrates that VS4 holds great promise in analytical method development.

Integrated biomarker profiling for enhanced heart failure management: a comprehensive study on the application of chemiluminescence detection of GDF-15 and multi-index models.

Growth differentiation factor 15 (GDF-15) holds promise as a novel marker for heart failure. However, current detection methods fall short of meeting essential clinical requirements. The aim of this investigation was to assess the clinical significance of serum GDF-15 detection through the chemiluminescence method and to enhance its clinical application for predicting and evaluating heart failure in patients. A total of 122 patients were included in the study. Serum GDF-15 levels were assessed using the chemiluminescence method and compared with results for NT-proBNP, N-terminal pro-brain natriuretic peptide (NT-proBNP), growth stimulation expressed gene 2 (ST2), high-sensitivity C-reactive protein (hs-CRP), and left ventricular ejection fraction (LVEF). Additionally, we conducted an analysis to evaluate the correlation between these indicators and heart failure events. LVEF, ST2, NT-proBNP, and GDF-15 exhibited significant associations with heart failure. In the multivariate proportional hazard analysis, subsequent to adjusting for the effects of other markers, however, only LVEF and GDF-15 retained their associations with heart failure events. Notably, GDF-15 emerged as the exclusive marker suitable for diagnosing heart failure with preserved ejection fraction. The chemiluminescence method proved efficient in the rapid and sensitive detection of GDF-15 in patients with heart failure. Additionally, GDF-15 combined with other markers created a robust multi-index model. This model is valuable for heart failure diagnosis, treatment, and monitoring, with broad clinical applicability.