A monoclonal antibody-based competitive antibody-coated enzyme-linked immunosorbent assay (ELISA) was developed and optimized for determining chlorpyrifos residue in agricultural products. The IC 50 and IC 10 of this ELISA were 3.3 ng/mL and 0.1 ng/mL respectively. The average recoveries in six agricultural products were between 79.5% and 118.0%, with the intra-assay coefficient of variation being less than 8 %. The limit of detection for all tested products was 30 ng/g. To the best of our knowledge, this assay has the best specificity among all the published research on ELISAs for chlorpyrifos.

The effectiveness of homologous and heterologous formats in a nanocolloidal gold-based immunoassay for pesticide residue determination was investigated. Parathion, one of the most toxic organophosphorus pesticides, was used as the target analyte. One-step homologous and heterologous test strips based on a nanocolloidal gold-labeled monoclonal antibody were developed for the rapid detection of parathion residues. The results showed that the heterologous format was more effective than the homologous format, being more sensitive, more specific to parathion and more tolerant of matrix interferences. The best competitive hapten was found to have a moderate heterology and the opposite electronic distribution to the immunizing hapten. The detection limits for parathion using the preferred heterologous strip were 1 μg/L in water samples and 5 μg/kg in soil and food samples.

Background Both multi‐morbidity (MM) and polypharmacy (PP) are common in the elderly and pose a challenge for health and social care systems. However, high‐quality patient‐centred care requires context‐bound understanding of the patterns and use of medications in those with MM. Therefore, the aim of this study was to investigate the prevalence of PP in community‐dwelling elderly, and the factors associated with MM, PP, excessive polypharmacy (EPP), and the types of drugs used. Methods We analysed data of 164 community‐dwelling subjects aged ≥60 years from January to December 2020 at a general hospital in a rural area of Taiwan. MM was defined as >4 diagnoses of chronic health conditions. Non‐polypharmacy (NP), PP, and EPP were defined as <5, 5–8, and >8 prescriptions, respectively. Other variables including basic activities of daily living (BADL), severity of frailty, depressive mood, screening for intellectual impairment, and nutritional status were also analysed. Results Of the 164 participants, 34.8% had >4 diagnoses, 66.5% had PP, and 26.2% had EPP. The patients with >4 diagnoses had worse performance in BADL, higher levels of frailty, and more prescriptions than those with fewer diagnoses. The EPP group had worse performance in BADL, a higher level of frailty, more comorbidities, and higher prevalences of diabetes mellitus and chronic kidney disease compared to the NP and PP groups. After adjusting for covariates, we further found a higher number of medications associated with having more comorbidities, and a higher level of frailty associated with having a greater number of medications. Conclusion We found relationships between frailty and PP, and between PP and MM, but frailty did not associate with MM. Since frailty, PP, and MM may be viewed as an inevitable trinity of ageing, reducing PP could be a method to both prevent frailty and disentangle this trinity in the elderly.

The mechanism of specific recognition in pesticide immunochemistry was investigated by computer-based strategy, and a rapid method for the identification of antibody specificity was developed. Based on the previously produced anti-parathion monoclonal antibody (mAb), the DNA sequence was analyzed by polymerase chain reaction (PCR). From the translated amino acid sequences, a three-dimensional structure of the antibody was constructed by homology modeling method, and then it was coordinated by 1 ns molecular dynamics under the explicit solvent condition. The stereochemical property and folding quality were further assessed by Procheck and Profile-3D. The self-compatibility score for the antibody model was 98.7, which was greater than the low score 46.2 and close to the top score 102.6. In addition, parathion and several structural analogues were docked to the constructed antibody structure. The docking results showed that the interaction energy (-40.54 kcal/mol) of antibody-parathion complex was the lowest among all the tested pesticides, which accounted for the high specificity of the antibody to parathion and perfectly matched with the experimental data. Moreover, three residues, Phe165, Asp107 and Thr100 were recognized as the most important residues for antibody reacting with parathion. The interaction energy negatively correlated with the antibody specificity.

A new method for specific antibody production was developed using antibody (Ab)-pesticide complex as a unique immunogen. Parathion (PA) was the targeted pesticide, and rabbit polyclonal antibody (Pab) and mouse monoclonal antibody (Mab) were used as carrier proteins. The Ab-PA complexes were generated by conjugating the two antibodies with an excessive dosage of PA. It was shown that the sensitivity of homologous enzyme-linked immunosorbent assay (ELISA) using the new antibodies was similar to that using original antibodies. However, the new mouse Pab had not only similar positive recognizing spectrum as the original Mab, but also a significantly improved sensitivity in heterologous ELISA when some recognizable competitors were applied. IC(50) value of ELISA based on a combination of the new mouse Pab and hapten 9 was 0.24 ng/mL, which was 445.54 times as that of the homologous ELISA. An Ab-pesticide complex may be a suitable alternative immunogen for producing highly specific antibody to improve the immunoassay sensitivity.