Author: Eagle Biosciences

The Niacin Microtiter Plate Assay Kit was utilized in a recent study! Researchers developed a novel approach to study microglia, key immune cells in the CNS, under different conditions. Read on for a summary of this groundbreaking research!

Summary

Microglia are the resident macrophages of the central nervous system (CNS). Their phagocytic activity is central during brain development and homeostasis—and in a plethora of brain pathologies. However, little is known about the composition, dynamics, and function of human microglial phagosomes under homeostatic and pathological conditions. Here, we developed a method for rapid isolation of pure and intact phagosomes from human pluripotent stem cell-derived microglia under various in vitro conditions, and from human brain biopsies, for unbiased multiomic analysis. Phagosome profiling revealed that microglial phagosomes were equipped to sense minute changes in their environment and were highly dynamic. We detected proteins involved in synapse homeostasis, or implicated in brain pathologies, and identified the phagosome as the site where quinolinic acid was stored and metabolized for de novo nicotinamide adenine dinucleotide (NAD+) generation in the cytoplasm. Our findings highlight the central role of phagosomes in microglial functioning in the healthy and diseased brain.

Wogram, E et al. Rapid phagosome isolation enables unbiased multiomic analysis of human microglial phagosomes. Immunity. 57(9)p:2216-2231.e11 doi:10.1016/j.immuni.2024.07.019

If you have any questions about the Niacin Microtiter Plate Assay Kit or any of our other offerings, contact us here.

The Aldosterone ELISA Assay Kit was utilized in a recent study! The study looked at how blood flow in the kidneys and biomarker levels relate to kidney and heart problems in children experiencing shock. Access the abstract and full text below.

Abstract

Importance: Pediatric acute kidney injury (AKI) is a prevalent and morbid complication of shock. Its pathogenesis and early identification remain elusive.

Objectives: We aim to determine whether renal blood flow (RBF) measurements by point-of-care ultrasound (POCUS) and renin-angiotensin-aldosterone system (RAAS) hormones in pediatric shock associate with vasoactive requirements and AKI.

Design, Setting, and Participants: This is a single-center prospective, noninterventional observational cohort study in one tertiary PICU in North American from 2020 to 2022 that enrolled children younger than 18 years with shock without preexisting end-stage renal disease.

Main Outcomes and Measures: RBF was measured by POCUS on hospital days 1 and 3 and plasma RAAS hormone levels were measured on day 1. The primary outcome was the presence of AKI by Kidney Disease Improving Global Outcomes criteria at first ultrasound with key secondary outcomes of creatinine, blood urea nitrogen (BUN), Vasoactive-Inotrope Score (VIS), and norepinephrine equivalent dosing (NED) 48 hours after first ultrasound.

Results: Fifty patients were recruited (20 with AKI, mean age 10.5 yr, 48% female). POCUS RBF showed lower qualitative blood flow (power Doppler ultrasound [PDU] score) and higher regional vascular resistance (renal resistive index [RRI]) in children with AKI (p = 0.017 and p = 0.0007). Renin and aldosterone levels were higher in the AKI cohort (p = 0.003 and p = 0.007). Admission RRI and PDU associated with higher day 3 VIS and NED after adjusting for age, day 1 VIS, and RAAS hormones. Admission renin associated with higher day 3 creatinine and BUN after adjusting for age, day 1 VIS, and the ultrasound parameters.

Conclusions and Relevance: In pediatric shock, kidney blood flow was abnormal and renin and aldosterone were elevated in those with AKI. Kidney blood flow abnormalities are independently associated with future cardiovascular dysfunction; renin elevations are independently associated with future kidney dysfunction. Kidney blood flow by POCUS may identify children who will have persistent as opposed to resolving AKI. RAAS perturbations may drive AKI in pediatric shock.

Fisler, Grace et al. Kidney Blood Flow and Renin-Angiotensin-Aldosterone System Measurements Associated With Kidney and Cardiovascular Dysfunction in Pediatric Shock. Critical Care Explorations 6(8):p e1134, August 2024. DOI: 10.1097

If you have any questions about this product or any of our other offerings, contact us here.

In a recent study, researchers employed the FGF23 C-Terminal ELISA Kit from Biomedica Immunoassays to explore the link between dietary phosphorus and key health markers among Puerto Rican adults. Dive into the findings to learn how phosphorus intake from various foods might impact health!

Abstract

Phosphorus (P) additives may be deleterious for health. We measured the P content of key foods, and associations of P intake with biomarkers in the Boston Puerto Rican Health Study (BPRHS). Direct chemical analysis of 92 foods was done with the molybdenum blue spectrophotometric method and inductively coupled plasma mass spectrometry (ICP-MS). A novel algorithm was used to determine bioavailable, natural, and added P. We estimated P intakes from foods in 1323 participants, aged 45–75 y, and associations of these with serum P, fibroblast growth factor 23 (FGF23), parathyroid hormone (PTH), and Klotho. Relationships between intakes and status markers were assessed with Pearson’s correlations and t-tests. Our food analyses generally support P values in the USDA nutrient database, with the exceptions of American and cheddar cheese, which had more P than in the database. Women had higher added P intake than men, and younger participants had higher added P than those older. Total P intake tended to be positively associated with serum P and klotho, and inversely associated with PTH, but relationships were not strong. Puerto Rican adults have high intake of additive P. Culturally sensitive interventions that highlight dietary quality are needed.

O.J. Akinlawon, et al. Phosphorous intake in foods and phosphorus status markers in circulation in the Boston Puerto Rican Health Study, Journal of Food Composition and Analysis, Volume 136, 2024, 106681, ISSN 0889-1575, https://doi.org/10.1016/j.jfca.2024.106681.

If you have any questions about this product or any of our other offerings, contact us here.

Researchers recently utilized our Calprotectin ELISA Assay Kit in an innovative study examining a new treatment for cystic fibrosis (CF)! The study focused on how this treatment influenced both the intestinal microbiome and inflammation, alongside important clinical markers in children with CF. Check out the abstract and access the full text of the study below.

Abstract

The intestinal microbiome influences growth and disease progression in children with cystic fibrosis (CF). Elexacaftor-tezacaftor-ivacaftor (ELX/TEZ/IVA), the newest pharmaceutical modulator for CF, restores the function of the pathogenic mutated CF transmembrane conductance regulator (CFTR) channel. We performed a single-center longitudinal analysis of the effect of ELX/TEZ/IVA on the intestinal microbiome, intestinal inflammation, and clinical parameters in children with CF. Following ELX/TEZ/IVA, children with CF had significant improvements in body mass index and percent predicted forced expiratory volume in one second, and required fewer antibiotics for respiratory infections. Intestinal microbiome diversity increased following ELX/TEZ/IVA coupled with a decrease in the intestinal carriage of Staphylococcus aureus, the predominant respiratory pathogen in children with CF. There was a reduced abundance of microbiome-encoded antibiotic resistance genes. Microbial pathways for aerobic respiration were reduced after ELX/TEZ/IVA. The abundance of microbial acid tolerance genes was reduced, indicating microbial adaptation to increased CFTR function. In all, this study represents the first comprehensive analysis of the intestinal microbiome in children with CF receiving ELX/TEZ/IVA.

Reasoner SA, et al. 2024. Longitudinal profiling of the intestinal microbiome in children with cystic fibrosis treated with elexacaftor-tezacaftor-ivacaftor. mBio 15:e01935-23.https://doi.org/10.1128/mbio.01935-23

If you have any questions about the Calprotectin ELISA or any of our other offerings, contact us here.

Researchers employed the Infliximab ELISA Assay Kit in a new study aimed at uncovering the connection between infliximab concentrations in tissue and plasma and their impact on ulcerative colitis (UC) disease activity. Explore the full abstract and access the detailed research below.

Abstract

Background: We aimed to determine the correlation between tissue and plasma infliximab concentrations in an outpatient ulcerative colitis (UC) cohort based on histologic disease activity in addition to their relationship with long-term clinical outcomes. We assessed intraparticipant variability in infliximab concentrations between adjacent intestinal samples and the correlation between disease activity and tumor necrosis factor-α (TNF-α).

Methods: A prospective cohort study was conducted in participants with UC receiving infliximab. Blood and 2 sigmoid colon biopsies were obtained at the index colonoscopy for infliximab and TNF-α quantification. Histological disease activity was assessed. Participants were followed for 2 years for the occurrence of hospitalization, surgery, disease relapse, and infliximab discontinuation.

Results: A positive correlation was observed between mean plasma and uninflamed tissue infliximab concentrations only (Rs = 0.75, P = .0071). Lower mean tissue infliximab concentrations correlated with a shorter time to disease relapse vs those with higher mean tissue concentrations (Rs = 0.77, P = .032). This was not seen when using plasma infliximab concentrations. Additionally, no significant intraparticipant variability of infliximab concentrations was observed for all participants independent of disease activity. Neither plasma nor tissue TNF-α correlated with disease activity.

Conclusions: These findings support data generated in patients with Crohn’s disease: plasma infliximab concentrations are reflective of infliximab exposure in tissue in the UC patient in remission, but not for those with active disease. Increasing tissue concentrations in the noninflamed tissues may improve durability of infliximab. Neither plasma nor tissue TNF-α appear to correlate with UC disease activity. Larger follow-up studies would be of benefit.

John Choi, Qian Wang, Melanie Beaton, Richard B Kim, Reena Khanna, Aze Wilson, Infliximab Tissue Concentrations in Patients With Stable Ulcerative Colitis Are Correlated With More Durable Infliximab-associated Disease Remission, Inflammatory Bowel Diseases, 2024;, izae097, https://doi.org/10.1093/ibd/izae097

If you have any questions about this product or any of our other offerings, contact us here.

A new study has featured the Noradrenaline (Norepinephrine) HS ELISA from DLD Diagnostika! Researchers provide mechanistic insights into C. difficile-associated pathogenesis and help illuminate a target for intervention to limit recurrent disease. Check out the summary and full text below.

Summary

Recurrent Clostridioides difficile infection (CDI) results in significant morbidity and mortality. We previously established that CDI in mice does not protect against reinfection and is associated with poor pathogen-specific B cell memory (Bmem), recapitulating our observations with human Bmem. Here, we demonstrate that the secreted toxin TcdB2 is responsible for subversion of Bmem responses. TcdB2 from an endemic C. difficile strain delayed immunoglobulin G (IgG) class switch following vaccination, attenuated IgG recall to a vaccine booster, and prevented germinal center formation. The mechanism of TcdB2 action included increased B cell CXCR4 expression and responsiveness to its ligand CXCL12, accounting for altered cell migration and a failure of germinal center-dependent Bmem. These results were reproduced in a C. difficile infection model, and a US Food and Drug Administration (FDA)-approved CXCR4-blocking drug rescued germinal center formation. We therefore provide mechanistic insights into C. difficile-associated pathogenesis and illuminate a target for clinical intervention to limit recurrent disease.

Norman KM, et al. Clostridioides difficile toxin B subverts germinal center and antibody recall responses by stimulating a drug-treatable CXCR4-dependent mechanism. Cell Reports. 2024. https://doi.org/10.1016/j.celrep.2024.114245.

If you have any questions about the Noradrenaline (Norepinephrine) HS ELISA or any of our other offerings, contact us here.

Our Mouse/Rat 25-OH Vitamin D ELISA Assay Kit was featured in a recent study! Researchers used our kit to explore the impact of standard chow diets on animal model experiments and how diet-related variability can influence experimental outcomes. Check out the abstract and access to the full text below.

Abstract

Standard chow diet contributes to reproducibility in animal model experiments since chows differ in nutrient composition, which can independently influence phenotypes. However, there is little evidence of the role of timing in the extent of variability caused by chow exposure. Here, we measured the impact of diet (5V5M, 5V0G, 2920X, and 5058) and timing of exposure (adult exposure (AE), lifetime exposure (LE), and developmental exposure (DE)) on growth & development, metabolic health indicators, and gut bacterial microbiota profiles across genetically identical C57BL6/J mice. Diet drove differences in macro- and micronutrient intake for all exposure models. AE had no effect on measured outcomes. However, LE mice exhibited significant sex-dependent diet effects on growth, body weight, and body composition. LE effects were mostly absent in the DE model, where mice were exposed to chow differences from conception to weaning. Both AE and LE models exhibited similar diet-driven beta diversity profiles for the gut bacterial microbiota, with 5058 diet driving the most distinct profile. Diet-induced beta diversity profiles were sex-dependent for LE mice. Compared to AE, LE drove 9X more diet-driven differentially abundant genera, majority of which were the result of inverse effects of 2920X and 5058. Our findings demonstrate that lifetime exposure to different chow diets has the greatest impact on reproducibility of experimental measures that are common components of preclinical mouse model studies. Importantly, weaning DE mice onto a uniform diet is likely an effective way to reduce unwanted phenotypic variability among experimental models.

Knuth M.M. et al. Timing of standard chow exposure determines the variability of mouse phenotypic outcomes and gut microbiota profile. bioRxiv. 2024. doi: 10.1101/2024.03.28.587032

If you have any questions about the Mouse/Rat 25-OH Vitamin D ELISA or any of our other offerings, contact us here.

Exciting news! Three of our gastrointestinal biomarker ELISA kits were integral to a recently published study. Using our Insulin ELISA Assay Kit, Calprotectin ELISA Assay Kit, High Sensitive CRP ELISA Assay Kit, researchers analyzed blood and stool samples from endurance runners. The study aimed to evaluate the effectiveness of probiotics in treating gastrointestinal injury and permeability. Check out the abstract and access to the full text below.

Abstract

Probiotics are increasingly used to treat conditions associated with gastrointestinal injury and permeability, including exercise-induced gastrointestinal discomfort. This study assessed safety and efficacy of a probiotic in altering the intestinal milieu and mitigating gastrointestinal symptoms (GIS) in endurance runners. In a double blind, crossover study, 16 runners were randomized to 4 weeks of daily supplementation with a probiotic cocktail containing Pediococcus acidilactici bacteria and Lactobacillus plantarum or placebo. Fasting blood and stool samples were collected for measurement of gut permeability markers, immune parameters, and microbiome analyses. Treadmill run tests were performed before and after treatment; participants ran at 65%–70% of VO2max at 27 °C for a maximum of 90 min or until fatigue/GIS developed. A blood sample was collected after the treadmill run test. In healthy individuals, 4 weeks of probiotic supplementation did not alter health parameters, although a marginal reduction in aspartate aminotransferase levels was observed with probiotic treatment only (p = 0.05). GIS, gut permeability-associated parameters (intestinal fatty acid binding protein, lipopolysaccharide binding protein, zonulin, and cytokines), and intestinal microbial content were not altered by the probiotic supplementation. Post-run measurements of GIS and gut-associated parameters did not differ between groups; however, the observed lack of differences is confounded by an absence of measurable functional outcome as GIS was not sufficiently induced during the run. Under the current study conditions, the probiotic was safe to use, and did not affect gut- or immune-associated parameters, or intestinal symptoms in a healthy population. The probiotic might reduce tissue damage, but more studies are warranted.

Lennon S., Lackie T., Miltko A., et al. Safety and efficacy of a probiotic cocktail containing P. acidilactici and L. plantarum for gastrointestinal discomfort in endurance runners: randomized double-blinded crossover clinical trial. Appl Physiol Nutr Metab. 2024. 49(7):890-903. DOI: 10.1139/apnm-2023-0449

If you have any questions about these three gastrointestinal biomarker ELISAs or any of our other offerings, contact us here.