Establishment of specific enzyme-linked immunosorbent assay (ELISA) for measuring Fsh and Lh levels in medaka (Oryzias latipes), using recombinant gonadotropins

The paucity of information on understanding the regulatory mechanisms that are involved in the control of piscine Fsh and Lh synthesis, secretion, and function, prompted the present work. Part of the problem is related to the molecular heterogeneity and the unavailability of Fsh and Lh assays for quantifying gonadotropins, in particular assays regarding the measurement of Fsh, and such assays are available today for only a few teleost species. The present study reports the development and validation of competitive ELISAs for quantitative determination of medaka Fsh and Lh by first producing medaka recombinant (md) gonadotropins mdFshβ, mdLhβ, mdFshβα, and mdLhβα by Pichia pastoris, generating specific antibodies against their respective β subunits, and their use within the development of ELISAs.

The advantages of this protocol include:

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The reproducibility of the ELISA demonstrated was relatively high, as shown by reasonably low intra- (Fsh 2.7%, Lh 3%) and interassay CVs (Fsh 5.3%, Lh 5.7%).

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The high degree of parallelism between serial dilutions of the recombinant and native pituitary-derived Fsh and Lh, may be a sign of similar structures and immunologically similarity.

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Two new competitive ELISAs for the quantification of medaka Fsh and Lh were established for the first time.

Seroprevalence and risk factors for peste des petits ruminants in sheep and goats in Djibouti

Despite the occurrence of peste des petits ruminants (PPR) in all other countries in the Horn of Africa, which engage in free animal movement, to date, PPR has not been reported in Djibouti. The objective of this study was to estimate the seroprevalence of PPR and its associated risk factors in sheep and goats in that country. A cross-sectional method was used with proportional sampling to allocate the number of small ruminants to be sampled from each of the country's regions (Ali Sabieh, Arta, Dikhil, Djibouti, Obock and Tadjourah). From a total of 1,516 serum samples tested, using a competitive enzyme-linked immunosorbent assay (cELISA), 91 were positive, with an overall 6% (95% confidence interval [CI] = 4.8-7.2) prevalence of antibodies to the PPR virus (PPRV). Antibodies to PPRV were detected in small ruminants from all the regions, excluding Obock. Seroprevalence was highest in the Tadjourah region (8.92%), whereas the lowest prevalence was observed in the Djibouti region (1.28%). The species, age and sex of the animals and the herd size were identified as risk factors for PPR seropositivity. The risk of goats testing positive for PPRV antibodies was2.95 (CI = 1.39-6.35) times that of sheep. Moreover, the risk of animals younger than two years testing positive for PPRV antibodies was 2.29 (CI = 1.47-3.56) times that of animals older than two years. Similarly, it was shown that female animals were more frequently infected (odds ratio [OR] = 3.82; CI = 1.51 to 9.67) than their male counterparts. In addition, small ruminants from small herds/flocks were more likely to be seropositive (OR = 2.06; CI = 1.10-3.83) than those from medium-sized herds/flocks. The present study revealed, for the first time, the widespread occurrence of PPRV antibodies in small ruminants in Djibouti with low prevalence.

Survey of contagious caprine pleuropneumonia in goat herds in the Thrace region of Turkey

Contagious caprine pleuropneumonia (CCPP) was detected for the first time on the European continent in the Thrace region of Turkey in 2002 following outbreaks of an unusually severe respiratory disease in goats. Mycoplasma capricolums ubspecies capripneumoniae (Mccp), the causative agent, was identified in many infected herds throughout the region by serological, bacteriological and molecular biological techniques. However, as no quantitative data on the prevalence and distribution of the disease have been gathered in the intervening years, the extent of infection is unknown. Consequently, in 2014, a random sample of 2,400 goats was drawn from a population of over 167,000 goats in the region by multistage sampling. Serum samples were collected and tested by a monoclonal antibodybased competitive enzyme-linked immunosorbent assay (cELISA). The overall prevalence of CCPP in Thrace was found to be just over 8%. The prevalence in the individual provinces was approximately 18%, 7%, 8% and 6% for Çanakkale, Edirne, K?rklareli and Tekirda?, respectively, while Istanbul province appeared to be CCPP-free. The results showed that CCPP has spread throughout the region and has become endemic, and may pose a potential risk to the neighbouring countries of Greece and Bulgaria. Mccp was regularly detected from lung samples of suspect goats until 2015 but since then there has been no further detection from clinical samples.

Development of a double-antibody sandwich ELISA for rapid detection to C-peptide in human urine

C-peptide level is recognized as an important indicator of diabetes diagnosis. A sensitive and specific double-antibody sandwich enzyme-linked immunosorbent assay for the detection of C-peptide based on double antibody sandwich method was studied in this paper. The rabbit and hen were innunized with PLL-C-peptide and BSA-C-peptide respectively to obtain specific Yolk antibody (IgY) and polyclonal antibody used to construct the sandwich ELISA for the measurement of C-peptide. The limit of detection was 0.51 μg/mL and the half maximal inhibitory concentration (IC50) was 3.26 μg/mL. The method developed in the study showed no evident cross-reactivity with other similar analogs. The detection standard curve of C-peptide exhibited a good linearity (R² = 0.9896, n = 15). 17 types of the urine of diabetes patients on c-peptide levels compared with the hospital type of diabetes information, with a conclusion of a high consistent rate. Therefore, the methods could be selectively used for rapid screening of C-peptide in human urine, and the type of diabetes has some referential significance.

An ultra-specific and sensitive sandwich ELISA for imatinib using two anti-imatinib antibodies

The development of an immunoassay for a low-molecular-weight drug first requires the identification of specific antibodies that do not cross-react with the drug's metabolites. If two antibodies can simultaneously recognize the entire structure of the drug, we can then utilize them to establish an ultra-specific sandwich ELISA, free from interference due to the metabolic products of the drug. This paper reports an ultra-specific and sensitive sandwich ELISA for determination of the tyrosine kinase inhibitor imatinib using two anti-imatinib antibodies. The anti-imatinib antibodies were obtained by two partial structures of imatinib as haptens (2-(5-amino-2-methylanilino)-4-(3-pyridyl)pyrimidine and 4-{(4-methyl-1-piperazinyl)-methyl}-benzoate). Under optimized conditions, this sandwich ELISA shows a linear detection range from 64 pg mL^-1 to 8 ng mL^-1, and a limit of detection of approximately 64 pg mL^-1 for 100-μL samples. The ELISA is specific to imatinib and while there was no cross-reactivity with the major metabolite N-desmethyl-imatinib, slight cross-reactivity was found with metabolite pyridine-N-oxide-imatinib. This assay demonstrated significantly lower cross-reactivity with metabolites than competitive ELISAs. Using this assay, drug levels were easily measured in rat blood after oral administration of imatinib via a single dose of 30 mg kg^-1 or 100 mg kg^-1. The levels in rat serum measured by this ELISA were comparable with those measured by HPLC, and there was a strong correlation between the values determined by the two methods (y = 0.983x + 0.081, R² = 0.948). Thus, we have successfully developed the first specific and sensitive sandwich ELISA for imatinib using two anti-imatinib antibodies. This sandwich ELISA will be a valuable tool for therapeutic drug monitoring and pharmacokinetic studies of imatinib.