Category: Publication Spotlight

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

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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.

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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

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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

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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.

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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

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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

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We’re excited to share that the Noradrenaline (Norepinephrine) Sensitive ELISA Assay Kit was featured in a recent publication! The study explored the link between Alzheimer’s Disease and osteoporosis using mouse models. Discover the abstract and access the full text below.

Abstract

Alzheimer’s disease (AD) and osteoporosis often coexist in the elderly. Although observational studies suggest an association between these two diseases, the pathophysiologic link between AD and skeletal health has been poorly defined. We examined the skeletal phenotype of 5xFAD mice, an AD model with accelerated neuron-specific amyloid-β accumulation causing full-blown AD phenotype by the age of 8 months. Micro-computed tomography indicated significantly lower trabecular and cortical bone parameters in 8-month-old male, but not female, 5xFAD mice than sex-matched wild-type littermates. Dynamic histomorphometry revealed reduced bone formation and increased bone resorption, and quantitative RT-PCR showed elevated skeletal RANKL gene expression in 5xFAD males. These mice also had diminished body fat percentage with unaltered lean mass, as determined by dual-energy X-ray absorptiometry (DXA), and elevated Ucp1 mRNA levels in brown adipose tissue, consistent with increased sympathetic tone, which may contribute to the osteopenia observed in 5xFAD males. Nevertheless, no significant changes could be detected between male 5xFAD and wild-type littermates regarding the serum and skeletal concentrations of norepinephrine. Thus, brain-specific amyloid-β pathology is associated with osteopenia and appears to affect both bone formation and bone resorption. Our findings shed new light on the pathophysiologic link between Alzheimer’s disease and osteoporosis.

Jung, Ay, Cyr et al. Amyloid-β neuropathology induces bone loss in male mice by suppressing bone formation and enhancing bone resoptioin. Bone Rep. 2024. 21:101771 DOI: 10.1016/j.bonr.2024.101771

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An innovative study leveraged multiple ELISA kits from our portfolio to investigate the impact of head-out cold water immersion on thyroid hormone concentrations. The researchers used a range of kits, such as the Free Triiodothyronine (fT3) ELISA, Triiodothyronine T3 ELISA Assay Kit, Free Thyroxine (fT4) ELISA Assay Kit, Thyroxine (T4) ELISA Assay Kit, and Thyroid Stimulating Hormone ELISA Assay Kit. Find the abstract and access to the full text below.

Abstract

This study tested the hypothesis that acute moderate normobaric hypoxia augments circulating thyroid hormone concentrations during and following 1 h of cold head-out water immersion (HOWI), compared with when cold HOWI is completed during normobaric normoxia. In a randomized crossover single-blind design, 12 healthy adults (27 ± 2 yr, 2 women) completed 1 h of cold (22.0 ± 0.1°C) HOWI breathing either normobaric normoxia (F⁢IO2 = 0.21) or normobaric hypoxia (F⁢IO2 = 0.14). Free and total thyroxine (T3) and triiodothyronine (T4), and thyroid-stimulating hormone (TSH) concentrations were measured in venous blood samples obtained before (baseline), during (15-, 30-, and 60 min), and 15 min following HOWI (post-), and were corrected for changes in plasma volume. Arterial oxyhemoglobin saturation and core (rectal) temperature were measured continuously. Arterial oxyhemoglobin saturation was lower during hypoxia (90 ± 3%) compared with normoxia (98 ± 1%, P < 0.001). Core temperature fell from baseline (normoxia: 37.2 ± 0.4°C, hypoxia: 37.2 ± 0.4°C) to post-cold HOWI (normoxia: 36.4 ± 0.5°C, hypoxia: 36.3 ± 0.5°C, P < 0.001) in both conditions but did not change differently between conditions (condition × time: P = 0.552). Circulating TSH, total T3, free T4, total T3, and free T4 concentrations demonstrated significant main effects of time (all P ≤ 0.024), but these changes did not differ between normoxic and hypoxic conditions (condition × time: all P ≥ 0.163). These data indicate that acute moderate normobaric hypoxia does not modify the circulating thyroid hormone response during 1 h of cold HOWI.

Keeler JM, et al. Acute moderate normobaric hypoxia does not modify circulating thyroid hormone concentrations induced by 1 h of head-out cold-water immersion. Journal of Applied Physiology. 2024 136(6):1400-1409. https://doi.org/10.1152/japplphysiol.00061.2024

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In their latest research, scientists utilized the Creatinine Microplate Assay Kit to shed light on why lung cancer is more prevalent among African Americans compared to Whites, even when both groups have similar smoking habits. See the abstract and full text below.

Abstract

Background: After accounting for smoking history, lung cancer incidence is greater in African Americans than Whites. In the multiethnic cohort, total nicotine equivalents (TNE) are higher in African Americans than Whites at similar reported cigarettes per day. Greater toxicant uptake per cigarette may contribute to the greater lung cancer risk of African Americans.

Methods: In a nested case–control lung cancer study within the Southern Community Cohort, smoking-related biomarkers were measured in 259 cases and 503 controls (40% White; 56% African American). TNE, the trans-3-hydroxycotinine/cotinine ratio, 4-(methylnitrosamino)-1–3-(pyridyl)-1-butanol (NNAL), mercapturic acid metabolites of volatile organic compounds, phenanthrene metabolites, cadmium (Cd), and (Z)-7-(1R,2R,3R,5S)-3,5-dihydroxy-2-[(E,3S)-3-hydroxyoct-1-enyl]cyclopenyl]hept-5-enoic acid were quantified in urine. Unconditional logistic regression was used to estimate the ORs and 95% confidence intervals (CI) for each biomarker and lung cancer risk.

Results: TNE, NNAL, and Cd were higher in cases than controls (adjusted for age, race, sex, body mass index, and cigarettes per day). Among cases, these levels were higher in African Americans compared with Whites. After accounting for age, sex, body mass index, and pack-years, a one-SD increase in log-TNE (OR = 1.30; 95% CI, 1.10–1.54) and log-NNAL (OR = 1.27; 95% CI, 1.03–1.58 with TNE adjustment) was associated with lung cancer risk. In this study, in which NNAL concentration is relatively high, the association for log-TNE was attenuated after adjustment for log-NNAL.

Conclusions: Smoking-related biomarkers provide additional information for lung cancer risk in smokers beyond smoking pack-years.

Murphy, Guillermo, Thomson et al. Association of urinary biomarkers of tobacco exposure with lung cancer risk in African American and White cigarette smokers in the Southern Community Cohort Study. Cancer Epidemiol Biomarkers Prev. (2024) https://doi.org/10.1158/1055-9965.EPI-23-1362

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