Commercial Enzyme-linked Immunosorbent Assay Research Articles

Next-Generation Electrochemical Biosensing Based on Ternary Nanocomposites of nMoS2@Rgo@MWCNT for Label-Free Cancer Biomarker Detection in Undiluted Human Serum

Sperm protein-17 (Sp17) is a cancer-testicular antigen that is expressed in various types of cancers and has been proposed as a potential biomarker for cancer. However, the detection of Sp17 in human serum is challenging due to its low concentration and the lack of specific and sensitive methods. Hence, there is an urgent need to develop fast, accurate, reliable, and cost-effective disposable biosensors for Sp17 detection. Herein, we report sensing of Sp17 with a disposable carbon cloth-based electrode (CC) modified with a ternary nanocomposite comprising molybdenum disulphide (MoS2), reduced graphene oxide (rGO), and multi-walled carbon nanotube (MWCNT). The nanocomposite was synthesized by a facile hydrothermal method and was well-characterized in terms of structural, morphological, and chemical attributes using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Raman spectroscopy spectral techniques, and electrochemical studies to prove the robust formation of the electroactive ternary nanocomposite and its suitability for Sp17 detection. The nanocomposite exhibited excellent electrocatalytic activity, biocompatibility, and stability. We immobilized a Sp17-specific antibody on the surface of the nanocomposite-modified electrode and used it as a biosensor for Sp17 detection. The biosensor showed a linear response range from 0.01 to 11 ng mL-1 and a limit of detection (LOD) and limit of quantification (LOQ) of 0.23 ng mL-1 and 0.79 ng mL-1, respectively having sensitivity of 9.97 mA ng mL-1 cm-2. The biosensor was successfully applied to detect Sp17 in human serum samples and showed good accuracy, reproducibility, and selectivity, making it helpful for use in translational medicine research and clinical applications. The biosensor also demonstrated a high correlation with a commercial enzyme-linked immunosorbent assay (ELISA) kit. Our results suggest that the proposed biosensor is a promising tool for Sp17 detection in human serum and could be useful for the diagnosis and prognosis of ovarian cancer and other Sp17-related cancers. Keywords: Carbon cloth; Biosensor; Electrochemistry; Sperm protein 17; Cancer biomarker; Nanocomposite

Estimating the Seroincidence of Scrub Typhus using Antibody Dynamics after Infection.

Scrub typhus, a vector-borne bacterial infection, is an important but neglected disease globally. Accurately characterizing the burden is challenging because of nonspecific symptoms and limited diagnostics. Prior seroepidemiology studies have struggled to find consensus cutoffs that permit comparisons of estimates across contexts and time. In this study, we present a novel approach that does not require a cutoff and instead uses information about antibody kinetics after infection to estimate seroincidence. We use data from three cohorts of scrub typhus patients in Chiang Rai, Thailand, and Vellore, India, to characterize antibody kinetics after infection and two population serosurveys in the Kathmandu Valley, Nepal, and Tamil Nadu, India, to estimate seroincidence. The samples were tested for IgM and IgG responses to Orientia tsutsugamushi-derived recombinant 56-kDa antigen using commercial enzyme-linked immunosorbent assay kits. We used Bayesian hierarchical models to characterize antibody responses after scrub typhus infection and used the joint distributions of the peak antibody titers and decay rates to estimate population-level incidence rates in the cross-sectional serosurveys. Median responses persisted above an optical density (OD) of 1.8 for 23.6 months for IgG and an OD of 1 for 4.5 months for IgM. Among 18- to 29-year-olds, the seroincidence was 10 per 1,000 person-years (95% CI, 5-19) in Tamil Nadu, India, and 14 per 1,000 person-years (95% CI: 10-20) in the Kathmandu Valley, Nepal. When seroincidence was calculated with antibody decay ignored, the disease burden was underestimated by more than 50%. The approach can be deployed prospectively, coupled with existing serosurveys, or leverage banked samples to efficiently generate scrub typhus seroincidence estimates.

Comparison of in-house enzyme-linked immunosorbent assay (ELISA) and six commercial ELISAs for Detection of antibodies to Bordetella pertussis

Enzyme-linked immunosorbent assays (ELISA) are currently the method of choice for the serodiagnosis of pertussis and play a key role in the diagnosis of pertussis in adolescents and adults, as well as in epidemiological studies. In the present study, the in-house developed indirect ELISA was comparatively evaluated with six commercial kits from various manufacturers. Antipertussis antibodies were measured in 40 serum samples from patients with clinical symptoms of respiratory tract infection, in two WHO standards, and in seven human ECDC control sera. IgA and IgG antibodies were detected at a diagnostically significant level by different ELISA kits of 5.0% to 27.0% and 12.0% to 70.0% of patients' sera, appropriately. The analysis of results carried out with six commercial kits showed only 17.5% consistent results in class IgG (either clearly positive or negative). The average percentage of errors in the level of antibodies determined in the control samples, reference serum samples, differed quite significantly and ranged from 9.5% to 35.4% depending on the kit. This poor correlation of the results obtained on various serological tests intended for the serodiagnosis of pertussis may cause very serious diagnostic problems, especially when examining a serum sample obtained once during the course of the disease.

Development of plate-type and tubular chemiluminescence immunoassay against African swine fever virus p72

African swine fever (ASF) is a highly contagious and fatal viral disease that has caused huge economic losses to the pig and related industries worldwide. At present, rapid, accurate, and sensitive laboratory detection technologies are important means of preventing and controlling ASF. However, because attenuated strains of African swine fever virus (ASFV) are constantly emerging, an ASFV antibody could be used more effectively to investigate the virus and control the disease on pig farms. The isolation of ASFV-specific antibodies is also essential for the diagnosis of ASF. Therefore, in this study, we developed two chemiluminescence immunoassays (CLIAs) to detect antibodies directed against ASFV p72: a traditional plate-type blocking CLIA (p72-CLIA) and an automatic tubular competitive CLIA based on magnetic particles (p72-MPCLIA). We compared the diagnostic performance of these two methods to provide a feasible new method for the effective prevention and control of ASF and the purification of ASFV. The cut-off value, diagnostic sensitivity (Dsn), and diagnostic specificity (Dsp) of p72-CLIA were 40%, 100%, and 99.6%, respectively, in known background serum, whereas those of p72-MPCLIA were 36%, 100%, and 99.6%, respectively. Thus, both methods show good Dsn, Dsp, and repeatability. However, when analytical sensitivity was evaluated, p72-MPCLIA was more sensitive than p72-CLIA or a commercial enzyme-linked immunosorbent assay. More importantly, p72-MPCLIA reduced the detection time to 15 min and allowed fully automated detection. In summary, p72-MPCLIA showed superior diagnostic performance and offered a new tool for detecting ASFV infections in the future.Key points• Two chemiluminescence immunoassay (plate-type CLIA and tubular CLIA) methods based on p72 monoclonal antibody (mAb) were developed to detect ASFV antibody.• Both methods show good diagnostic performance (Dsn (100%), Dsp (99.6%), and good repeatability), and p72-MPCLIA detects antibodies against ASFV p72 with high efficiency in just 15 min.

Seroprevalence of swine hepatitis E virus and the farmers' potential risk of infection in the Province of Bali, Indonesia.

Hepatitis E virus (HEV) infection formerly and predominantly occurred in rural areas. However, it has recently been spread to urban and peri-urban areas. This study aimed to estimate the seroprevalence of HEV in pigs collected from urban and rural areas in Bali. The potential of the pig farmers' risk level for being exposed to HEV and the virus transmitted to them in association with their pig-rearing practices was also assessed. A total of 183 pigs from 68 herds were sampled in this study, with 91 pigs collected from Denpasar as the representative samples of urban areas and 92 pigs from Karangasem Regency as the representative samples from rural areas. Sera from the sampled pigs were collected and immunoglobulin G antibodies against HEV were detected using a commercial enzyme-linked immunosorbent assay. A questionnaire was prepared for interviewing the farmers. Bivariable and multivariable logistic regression analyses were performed to identify the putative factors associated with seropositivity. Meanwhile, the potential risk-incurring practices of the farmers for HEV being transmitted to them from their pig-rearing practices were assessed by scoring their responses from the interview. Overall, 23.5% (43/183) (95% confidence interval [CI]: 17.6-30.3) pig sera tested were detected to have the antibodies against HEV. Among 68 pig herds, 36.8% (25) (95% CI: 25.4-49.3) of them had antibodies in at least one pig sampled from each herd. Pigs sampled from Karangasem were 5 times (Odds ratio [OR] 5.34, 95% CI: 2.27-13.54, p < 0.001) more likely to be seropositive than pigs collected from Denpasar. However, no difference was found in the seropositivity to HEV in pig herds between Denpasar and Karangasem (p = 0.05). In assessing the pig rearing management factors, pig farmers from Denpasar were 3 times (OR 3.0, 95% CI: 1.07-8.52, p = 0.05) more likely to rear pigs for economic investment compared to the farmers from Karangasem. Regarding anticipating pig diseases that can be transmitted to humans, farmers from Denpasar were 6 times (OR 5.72, 95% CI: 1.48-26.7, p = 0.0074) more likely to anticipate zoonotic diseases compared to the farmers from Karangasem. Similarly, pig farmers from Denpasar were 3 times (OR 3.29, 95% CI: 1.08-10.23, p = 0.035) more likely to anticipate pig diseases that could be transmitted to humans than the farmers from Karangasem. Pig farmers from Denpasar had 4 times the odds (OR 4.49, 95% CI: 1.11-18.19, p = 0.03) of washing their hands after going to the pigpens compared to the farmers from Karangasem. All the participants were categorized as being at high risk of HEV exposure and transmission. IgG antibodies against HEV were detected among pigs reared in rural areas of Karangasem and those reared in urban areas of Denpasar. This suggests that the risk of HEV exposure and transmission in these areas is not negligible. To minimize the risk, public education on zoonotic diseases, including HEV infection, transmission, and prevention, needs to be implemented and particularly targeted to local pig farmers.

Super-resolution Multispectral Imaging Nanoimmunosensor for Simultaneous Detection of Diverse Early Cancer Biomarkers.

In medical diagnosis, relying on only one type of biomarker is insufficient to accurately identify cancer. Blood-based multicancer early detection can help identify more than one type of cancer from a single blood sample. In this study, a super-resolution multispectral imaging nanoimmunosensor (srMINI) based on three quantum dots (QDs) of different color conjugated with streptavidin was developed for the simultaneous screening of various cancer biomarkers in blood at the single-molecule level. In the experiment, the srMINI chip was used to simultaneously detect three key cancer biomarkers: carcinoembryonic antigen (CEA), C-reactive protein (CRP), and alpha-fetoprotein (AFP). The srMINI chip exhibited 108 times higher detection sensitivity of 0.18-0.5 ag/mL (1.1-2.6 zM) for these cancer biomarkers than commercial enzyme-linked immunosorbent assay kits because of the absence of interfering signals from the substrate, establishing considerable potential for multiplex detection of cancer biomarkers in blood. Therefore, the simultaneous detection of various cancer biomarkers using the developed srMINI chip with high diagnostic precision and accuracy is expected to play a decisive role in early diagnosis or community screening as a single-molecule biosensor.

Untargeted blood serum proteomics identifies novel proteins related to neurological recovery after human spinal cord injury

BackgroundThe discovery of new prognostic biomarkers following spinal cord injury (SCI) is a rapidly growing field that could help uncover the underlying pathological mechanisms of SCI and aid in the development of new therapies. To date, this search has largely focused on the initial days after the lesion. However, during the subacute stage of SCI (weeks to months after the injury), there remains potential for sensorimotor recovery, and numerous secondary events develop in various organs. Additionally, the confounding effects of early interventions after the injury are less likely to interfere with the results.MethodsIn this study, we conducted an untargeted proteomics analysis to identify biomarkers of recovery in blood serum samples during the subacute phase of SCI patients, comparing those with strong recovery to those with no recovery between 30 and 120 days. We analyzed the fraction of serum that is depleted of the most abundant proteins to unmask proteins that would otherwise go undetected. Linear models were used to identify peptides and proteins related to neurological recovery and we validated changes in some of these proteins using Enzyme-linked Immunosorbent Assay (ELISA).ResultsOur findings reveal that differences in subacute recovery after SCI (from 30 to 120 days) are associated with an enrichment in proteins involved in inflammation, coagulation, and lipid metabolism. Technical validation using commercial ELISAs further confirms that high levels of SERPINE1 and ARHGAP35 are associated with strong neurological recovery, while high levels of CD300a and DEFA1 are associated with a lack of recovery.ConclusionsOur study identifies new candidates for biomarkers of neurological recovery and for novel therapeutic targets after SCI.

P-673 Tubulointerstitial nephritis antigen-like 1 (TINAGL1) expression is lower in the follicular fluid of patients with diminished ovarian reserve (DOR): A novel biomarker

Abstract Study question Are TINAGL1 levels in follicular fluid associated with ovarian reserve in patients undergoing ovarian stimulation for in-vitro fertilization (IVF)? Summary answer TINAGL1 concentration was lower in the follicular fluid (FF) of patients with DOR vs patients without infertility or polycystic ovarian syndrome (PCOS). What is known already TINAGL1 is an extracellular matrix protein involved in cell adhesion, proliferation, migration, and differentiation. TINAGL1 has previously been shown to be expressed in the mouse ovary and to be a serum biomarker that varies throughout the mouse estrous cycle, peaking in the estrous phase. Furthermore, TINAGL1 knockout mice have been shown to be infertile. TINAGL1 expression in the human ovary has not been previously evaluated. Study design, size, duration Between 2019 and 2023, a prospective study of 136 patients undergoing ovarian stimulation and oocyte retrieval (OR) was conducted at a single academic fertility center to assess TINAGL1 levels in luteinized FF and granulosa cells. Study groups were determined by infertility diagnosis: DOR n = 24, polycystic ovary syndrome (PCOS) n = 27, and control n = 85 (undergoing fertility preservation or had a partner with male factor only). Participants/materials, setting, methods TINAGL1 protein levels were quantified in the FF of patients that underwent OR via commercial enzyme-linked immunosorbent assay (ELISA). Granulosa cells were recovered from FF after OR, underwent lysis, RNA extraction, cDNA amplification and TINAGL1 mRNA expression was quantified via quantitative real-time polymerase chain reaction (qPCR). Demographics and infertility diagnoses were collected from the medical record. TINAGL1 levels were compared between the three groups. Statistical analysis was performed with parametric and non-parametric tests as appropriate. Main results and the role of chance Patients with DOR were younger when compared to the control and the PCOS group [Mean(SD) 32.7 (3.8) vs 34.45(3.9) vs 37.7 (3.0) years, p &amp;lt; 0.001] and had lower AMH levels [1.19 (0.8) vs 3.96 (3.03) vs 8.67 (4.56) ng/ml, p &amp;lt; 0.001]. TINAGL1 protein concentration in FF was measured by ELISA. Mean (SD) TINAGL1 levels were highest in PCOS, and lowest in the DOR group. Mean TINAGL1 levels were higher in the FF of the PCOS group when compared to the control group [4.73(7.15) vs 4.45 (4.57) ng/ml, p = 0.83] but this difference did not reach statistical significance. However, mean TINAGL1 FF levels were significantly lower in the DOR group when compared to the control group [2.54 (1.6) vs 4.48 (4.57) ng/ml, p = 0.04]. TINAGL1 was also found to be expressed in the granulosa cells with qPCR. TINAGL1 expression was upregulated by (+89%) in the PCOS group vs the control group (p = 0.0095). Importantly, there was a trend for decreased (-52%) TINAGL1 expression in DOR when compared to the control group (p = 0.67). The latter result should be interpreted with caution since only a subset of samples had sufficient granulosa cells for RNA extraction (DOR=4, control=18, PCOS=5). Limitations, reasons for caution This is a single institution study with a small number of patients in the DOR group (n = 24). Wider implications of the findings This is the first study to show that TINAGL1 is expressed in human granulosa cells. Decreased TINAGL1 may be a biomarker associated with DOR. Future studies should assess serum TINAGL1 levels at baseline and during ovarian stimulation and its contribution to the pathophysiology of DOR. Trial registration number Not applicable

Concave single-atom Co nanozymes with densely edge-hosted active sites for highly sensitive immunoassay

Regulating the geometric and electronic structures of single-atom catalysts could promote the potential to improve their enzyme-like catalytic performance. Herein, we demonstrate that concave single-atom Co catalysts with edge-hosted and dense active Co-N4 sites incorporated in nitrogen-doped hierarchical porous carbon (H-Co SACs) can act as highly efficient oxidase mimics. In particular, the engineered H-Co SACs with dense active Co-N4 moieties in the edge sites were found to display 3.1 times higher catalytic activity than that of traditional intact Co single-atom catalysts (L-Co SACs). Combined experimental and theoretical simulations reveal that the geometric structure and the interactions between adjacent edge-hosted CoN4 sites synergistically affect the electronic structure of the Co single-atom nanozymes, resulting in strong oxygen adsorption/activation and low energy barrier of the rate-determining step (RDS) in the reaction process, which are demonstrated be more beneficial for the oxidase-like catalytic performance. As a proof-of-concept application, the H-Co SACs were applied to the colorimetric enzyme-linked immunosorbent assay (ELISA) of neuron specific enolase (NSE) with a detection limit of 5.19 pg/ mL, outperforming both the intact Co single-atom catalysts and standard commercial ELISA kits. The present study could not only highlight the significance of geometric structure and active sites density effect on their enzyme-like catalytic efficiency, but also broaden their practical clinical application range of nanozymes at the atomic level.

Ultrasensitive detection of MMP-8 in saliva for monitoring periodontitis using an Immuno-CRISPR/Cas12a assay

Periodontitis is one of the most prevalent oral diseases, and the diagnosis and monitoring of periodontitis rely on clinical and imaging examinations. Matrix metalloproteinase-8 (MMP-8) in saliva is a reliable indicator of periodontitis. The traditional detection method is enzyme-linked immunosorbent assay (ELISA), which requires professional expertise and is not sensitive enough to low-abundance protein detection. In this study, we developed a nanoimmunoassay combined with clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR associated protein (Cas)12a for ultrasensitive detection of MMP-8 in saliva. Antibody-DNA-gold nanoparticles (AuNPs) and trans-cleavage activity of CRISPR/Cas12a were employed for signal amplification. With this protocol, the limit of detection (LoD) for MMP-8 was reduced to the fg/mL, indicating 100-fold higher sensitivity than that of the commercial ELISA kit and its amenability for ultrasensitive detection of trace proteins. The diagnostic sensitivity of the assay was 100 %, and the specificity was 83.3 % based on the testing of 23 clinical saliva samples. The sensitivity and specificity were considerably higher than those for ELISA. Thus, this immuno-CRISPR/Cas12a assay holds promise for both diagnosing and monitoring periodontitis in clinical settings.

Evaluation of longitudinal passive immunity transfer against lumpy skin disease virus in calves by different serological methods

To implement effective lumpy skin disease (LSD) control measures, such as timely vaccination, particularly in calves and serological monitoring, it is necessary to evaluate immune response after vaccination, both in adult cattle and in their calves. The aim of this study was to evaluate passive immunity transfer and duration of maternal antibodies against lumpy skin disease virus (LSDV) in calves born to vaccinated cows by two different serological methods. The longitudinal study was carried out on two farms in Serbia where no cases were reported during LSD outbreak in 2016. Fifteen cows on each farm were vaccinated and revaccinated with attenuated vaccine - Neethling strain. A total of 30 cows and 30 calves on both farms were included in the study. Serum samples from cows were collected on calving day and serum samples from their respective calves on days 10, 20, 30, 45, 60, 75, 90, 105 and 120 after birth. Colostrum samples were collected only from 15 cows on one farm. In order to determine the presence of antibodies against LSDV a total of 30 cow sera samples, 15 colostrum samples and 270 calf sera samples were examined by commercial enzyme-linked immunosorbent assay (ELISA) and modified virus neutralization test (VNT). Overall, the performance of both serological tests was very satisfactory. The results of this longitudinal study showed that persistence of passive immunity in calves is less than 4 months, and that most calves are not protected against LSDV at that age. Since the vaccination is the most important control measure against LSDV, the recommended age of six months for vaccination of calves born to vaccinated cows should be reassessed to achieve the most optimal protection against LSD.

Osteocalcin: A Potential Marker of Peripheral Arterial Stiffness in Hypertensive Patients.

Background and Objectives: Brachial-ankle pulse wave velocity (baPWV) is an established independent risk factor for cardiovascular events, cardiovascular mortality, and all-cause mortality. Osteocalcin (OC) is recognized to be associated with vascular function. The present study assessed the correlation between serum OC levels and peripheral arterial stiffness (PAS) measured through baPWV in hypertensive patients. Materials and Methods: Fasting blood samples were collected from 120 hypertensive participants. The serum total OC levels were measured using a commercial enzyme-linked immunosorbent assay kit, whereas the baPWV device was used to detect PAS. The PAS group had left or right baPWV > 18.0 m/s. Results: Among the hypertensive patients, 24 (20.0%) were classified into the PAS group. The PAS group exhibited a significantly older age (p = 0.011), higher prevalence of diabetes (p = 0.010), systolic blood pressure (p = 0.019), levels of serum fasting glucose (p = 0.003), blood urea nitrogen (p = 0.024), creatinine (p = 0.004), C-reactive protein (p = 0.007), OC (p = 0.002), and lower estimated glomerular filtration rate (p = 0.004) than the non-PAS group. Age (odds ratio [OR]: 1.076, 95% CI: 1.004-1.153, p = 0.037) and serum OC level (OR: 1.797, 95% confidence interval (CI): 1.077-3.000, p = 0.025) were independent factors linked to PAS in hypertensive patients in the multivariate logistic regression analysis. Conclusions: Serum OC levels and older age are positively associated with PAS in hypertensive patients.

Bone turnover markers and muscle decay indicator in patients with proximal femur fracture - a case-control study.

Fracture of the proximal femur is common in elderly patients, in fact threatening their lives. Age-related sarcopenia may be involved in the imbalance resulting in the injury. Handy and readily accessible biochemical tests would be useful to assess the musculoskeletal system condition in daily practice. The aim of the study was to determine whether there is any relation between muscle decay and fracture of the proximal femur and to assess bone quality in elderly patients. In the study 22 patients who represented the treatment group were hospitalized due to proximal femur fracture. Eighteen patients from the control group with no fracture in their history were admitted to the Internal Medicine Department. Anyone treated for osteoporosis, immune disease affecting protein balance, neoplasm, mental illness, heart failure, or myocardial infarction was excluded from the study. In every case a blood sample from an elbow vein was drawn, collected in EDTA-K2 tubes, and then centrifuged to separate plasma from the whole blood. Subsequently, the concentrations of C-terminal cross-linked telopeptide of type I collagen (CTX-I), sex hormone binding globulin (SHBG) and creatine kinase (CK) in plasma were determined using commercial enzyme-linked immunosorbent assays. The CK plasma concentration differed between the patient groups (p = 0.011). The SHBG plasma concentration was significantly higher in the treatment group (p = 0.006), whereas a slight difference in CTX-I plasma concentration between the groups was found (p = 0.038). No significant correlations between plasma CK, SHBG or CTX-I were found (p > 0.05). Creatine kinase is actually not an appropriate marker for the clinical assessment of muscle tissue quality in patients with or at risk of proximal femur fracture. Analyzing the quality of bone tissue, we can conclude it was poorer in patients with proximal femur fracture than in the control group.

Salivary Testosterone Levels and Pain Perception Exhibit Sex-Specific Association in Healthy Adults But Not in Patients With Migraine

This study investigated the sex-specific associations between pain perception and testosterone levels in healthy controls (HCs) and patients with migraine. Male and female HCs and migraine patients were recruited. A series of questionnaires were completed by the participants to evaluate their psychosocial profiles, which included data on mood, stress, and sleep quality. Heat pain thresholds and suprathreshold pain ratings at 45 °C (referred to as the pain perception score [PPS]) were assessed using the Thermode system. Salivary testosterone levels were analyzed using a commercial enzyme-linked immunosorbent assay kit. A total of 88 HCs (men/women: 41/47, age: 29.9 ± 7.7 years) and 75 migraine patients (men/women: 30/45, age: 31.1 ± 7.7 years) completed all assessments. No significant differences were observed in either the psychosocial profiles or heat pain thresholds and PPSs between the sexes in the control and migraine groups. A positive correlation between testosterone levels and PPSs was identified in the male controls (r = .341, P = .029), whereas a negative correlation was identified in the female controls (r = −.407, P = .005). No such correlations were identified in the migraine group. This study confirms that a negative association is present between PPSs and testosterone levels in female controls, which is in line with the findings that testosterone is associated with reduced pain perception. Our study is the first to demonstrate a sex-specific association between PPSs and testosterone levels in HCs. Moreover, this study also revealed that the presence of migraine appears to disrupt this association. PerspectiveThis study revealed that testosterone levels demonstrate opposite associations with pain perception in healthy men and women. However, the presence of migraine appears to disrupt this sex-specific association.

A universal three-dimensional hydrogel electrode for electrochemical detection of SARS-CoV-2 nucleocapsid protein and hydrogen peroxide

Coronavirus disease 2019 (COVID-19) is a highly contagious illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulting in a global health crisis. The primary diagnostic method for COVID-19 is quantitative reverse transcription PCR, which is time-consuming and requires expensive instrumentation. Here, we developed an electrochemical biosensor for detecting SARS-CoV-2 biomarkers using a 3D porous polyacrylamide/polyaniline hydrogel (PPG) electrode prepared by UV photopolymerization and in situ polymerization. The electrochemical immunosensor for detecting SARS-CoV-2 N protein via the immune sandwich principle demonstrated a lower detection limit of 42 pg/mL and comparable specificity to a commercial enzyme-linked immunosorbent assay, which was additionally validated in pseudoviruses. The electrochemical sensor for hydrogen peroxide showed a low detection limit of 0.5 μM and excellent selectivity, which was further confirmed in cancer cells under oxidative stress. The biomarkers of SARS-CoV-2 were successfully detected due to the signal amplification capability provided by 3D porous electrodes and the high sensitivity of the antigen-antibody specific binding. This study introduces a novel three-dimensional electrode with great potential for the early detection of SARS-CoV-2.

Clinical Usefulness of the serum-Soluble Transferrin Receptor in Iron Dysregulation Associated with long-Term Hemodialysis

Background: Soluble transferrin receptor (sTfR) was reported to be a valuable diagnostic marker for iron dysregulation (ID). Hepcidin, which is a key regulator of iron metabolism, has been shown to have increased values in patients undergoing hemodialysis (HD). Either treatment with erythropoietin stimulating agent（ESA） or iron repletion therapy（IRT）had been reported to induce controversial effect on serum levels between sTfR and hepcidin. Thus, we measured serum levels both of sTfR and hepcidin in 97 HD patients and investigated the clinical value of these measures. Methods: We used a commercial enzyme-linked immunosorbent assay kit to measure serum levels both of hepcidin and sTfR. Results: Although serum sTfR levels did not clearly increase, both sTfR levels and its index value correlated with the saturation of transferrin, erythropoietin-stimulating agent dosage, and erythropoietin resistance index (ERI). In addition, a strong negative correlation was found for sTfR and log serum hepcidin values. Conclusions: Serum sTfR levels and the sTfR index were acceptable markers for iron dysregulation (ID) and ERI even in patients undergoing HD whose serum levels of hepcidin increased.

Advancing cortisol measurements in zebrafish: Analytical validation of a commercial ELISA kit for skin mucus cortisol analysis

Cortisol is the main stress biomarker used for zebrafish. However, zebrafish small size made it challenging to extract cortisol without harming or killing the fish. Thus, researchers adopted a terminal method, the trunk cortisol, as standard practice. Here, we developed and validated an alternative and minimally invasive technique for measuring cortisol in the skin mucus of adult zebrafish, using a commercial enzyme-linked immunosorbent assay (ELISA). For this, AB zebrafish were randomly assigned to a precision, accuracy, and specificity test. Each sample contained the skin mucus of five to ten fish or one fish trunk. The cortisol was extracted using methanol as organic solvent. The results obtained showed an adequate precision (intra-assay coefficient of variation (CV) <15%; inter-assay CV = 26%), accuracy (CV <120%), and specificity (r2 =0.96–0.98) for skin mucus cortisol levels, as well as for trunk cortisol.•A commercial ELISA was analytically validated to measure cortisol in the skin mucus of zebrafish.•Skin mucus cortisol is a non-terminal method that reduce the number of animals used and allows longitudinal studies.

Crimean-Congo haemorrhagic fever outbreak in Northern Senegal in 2022: Prevalence of the virus in livestock and ticks, associated risk factors and epidemiological implications.

Crimean-Congo haemorrhagic fever (CCHF) is a severe zoonotic arboviral disease that occurs widely in Eastern and Western Europe, Asia and Africa. The disease is becoming of growing public health importance in Senegal. However, analysis of tick infestation, CCHF virus (CCHFV) circulation extent and risk factors during ongoing outbreak are scarce. A thorough outbreak investigation was carried out during a CCHF outbreak in Podor (Northern Senegal) in August 2022. Ticks and blood samples were collected from animals (cattle, goats and sheep) randomly selected from confirmed CCHF human cases houses, neighbourhoods and surrounding villages. Blood samples were tested for CCHFV antibodies using a commercial enzyme-linked immunosorbent assay (ELISA) test. Tick samples were screened for CCHFV RNA by RT-PCR. Overall, tick infestation rate (TIR) and CCHFV seroprevalence of livestock were 52.12% (95% confidence interval (CI): 45.54%-58.64%) and 43.28% (95% CI: 36.33%-50.44%), respectively. The TIRs were 87.7% in cattle, 57.6% in sheep and 20.0% in goats. These rates were significantly associated with location, host species and tick control (p < 0.001) but not with animal age and sex (p > 0.7). CCHFV seroprevalence was 80.4% (95% CI: 67.57%-89.77%) in cattle, 35.4% (95% CI: 25.00%-47.01%) in sheep and 21.2% (95% CI: 12.11%-33.02%) in goats. Age, sex, location, animal host and presence of ticks were significantly associated to the presence of antibodies. The 950 ticks collected included among other species, Hyalomma impeltatum (48.84%) and H. rufipes (10.21%). Five pools of Hyalomma ssp. were found CCHFV RT-PCR positive. These infected ticks included 0.86% (4/464) of H. impeltatum collected on cattle and sheep and 1.03% (1/97) of H. rufipes collected on a sheep. To our knowledge, this is the first report on the extend of tick infestation and CCHFV infection in livestock during an outbreak in Senegal. The results highlight the risk of human infections and the importance of strengthening vector, animal and human surveillance as well as tick control measures in this area to prevent CCHF infections in humans.

Development of a dual immunochromatographic test strip to detect E2 and Erns antibodies against classical swine fever.

It is essential to consider a practical antibody test to successfully implement marker vaccines and validate vaccination efficacy against classical swine fever virus (CSFV). The test should include a serological antibody assay, combined with a tool for differentiating infected from vaccinated animals (DIVA). The immunochromatographic test strip (ICS) has been exclusively designed for detecting CSFV E2 antibodies while lacking in detecting Erns antibodies, which can be employed and satisfy DIVA strategy. This study developed a novel ICS for detecting CSFV E2/Erns dual-antibody. The effectiveness of ICS in evaluating the DIVA capability of two novel chimeric pestivirus vaccine candidates was assessed. Recombinant E2 or Erns protein was transiently expressed in the plant benthamiana using Agrobacterium tumefaciens. ICS was subsequently assembled, and goat anti-rabbit IgG and recombinant CSFV E2 or Erns protein were plated onto the nitrocellulose membrane as control and test lines, respectively. The sensitivity and specificity of ICS were evaluated using sera with different neutralizing antibody titers or positive for antibodies against CSFV and other pestiviruses. The coincidence rates for detecting E2 and Erns antibodies between ICS and commercial enzyme-linked immunosorbent assay (ELISA) kits were also computed. ICS performance for DIVA capability was evaluated using sera from pigs vaccinated with conventional vaccine or chimeric vaccine candidates. E2 and Erns proteins were successfully expressed in N. benthamiana-produced recombinant proteins. ICS demonstrated high sensitivity in identifying CSFV E2 and Erns antibodies, even at the low neutralizing antibody titers. No cross-reactivity with antibodies from other pestiviruses was confirmed using ICS. There were high agreement rates of 93.0 and 96.5% between ICS and two commercial ELISA kits for E2 antibody testing. ICS also achieved strong coincidence rates of 92.9 and 89.3% with two ELISA kits for Erns antibody detection. ICS confirmed the absence of CSFV Erns-specific antibodies in sera from pigs vaccinated with chimeric vaccine candidates. E2 and Erns proteins derived from the plant showed great potential and can be used to engineer a CSFV E2/Erns dual-antibody ICS. The ICS was also highly sensitive and specific for detecting CSFV E2 and Erns antibodies. Significantly, ICS can fulfill the DIVA concept by incorporating chimeric vaccine candidates.

The incidence of coxiella infection in Iraqi women with early pregnancy loss

Query fever is a bacterial disease resulting from Coxiella burnetii (CB) infection in animals. It is well known that small ruminants who get Q fever lose their babies. People think pregnant women may also have lousy gestation results if they get the infection or the infection comes back to life during pregnancy. This study looks at how serologic results of Q fever and early pregnancy loss (EPL) are linked. In Baghdad, including Madinat Al-Imamain Al-Kadhmain Teaching Hospital and Abu Ghraib Hospital, multicenter case-control research was conducted from September to December 2022. A total of 90 women were enrolled in this investigation. Sixty clinically suffered from early pregnancy loss by having a nonviable intrauterine pregnancy. The other 30 women were subjects of comparable age, the week of pregnancy, and the healthy subjects as controls. Using a commercial enzyme-linked immunosorbent assay (ELISA), serum samples were screened for antibodies against CB. Three (5%) cases tested positive for CB by ELISA. The study reveals no association between adverse gestation outcomes and positive Q fever serology. Age and abortion history were not significantly correlated with C. burnetii seropositivity, according to the findings of CB cases that tested positive results.