Temporal Changes in Innate and Adaptive Immunity During Sepsis as Determined by ELISpot

Background

The inability to evaluate host immunity in a rapid quantitative manner in patients with sepsis has severely hampered development of novel immune therapies. The ELISpot assay is a functional bioassay that measures the number of cytokine-secreting cells and the relative amount of cytokine produced at the single-cell level. A key advantage of ELISpot is its excellent dynamic range enabling a more precise quantifiable assessment of host immunity. Herein, we tested the hypothesis on whether the ELISpot assay can detect dynamic changes in both innate and adaptive immunity as they often occur during sepsis. We also tested whether ELISpot could detect the effect of immune drug therapies to modulate innate and adaptive immunity.

Methods

Mice were made septic using sublethal cecal ligation and puncture (CLP). Blood and spleens were harvested serially and ex vivo IFN-γ and TNF-α production were compared by ELISpot and ELISA. The capability of ELISpot to detect changes in innate and adaptive immunity due to in vivo immune therapy with dexamethasone, IL-7, and arginine was also evaluated.

Results

ELISpot confirmed a decreased innate and adaptive immunity responsiveness during sepsis progression. More importantly, ELISpot was also able to detect changes in adaptive and innate immunity in response to immune-modulatory reagents, for example dexamethasone, arginine, and IL-7 in a readily quantifiable manner, as predicted by the reagents known mechanisms of action. ELISpot and ELISA results tended to parallel one another although some differences were noted.

Conclusion

ELISpot offers a unique capability to assess the functional status of both adaptive and innate immunity over time. The results presented herein demonstrate that ELISpot can also be used to detect and follow the in vivo effects of drugs to ameliorate sepsis-induced immune dysfunction. This capability would be a major advance in guiding new immune therapies in sepsis.

Bisphenol A detection based on nano gold-doped molecular imprinting electrochemical sensor with enhanced sensitivity

A facile electrochemical sensor based on nano gold-doped molecularly imprinted polymer (MIP) was proposed to realize the selective detection of bisphenol A (BPA) with enhanced sensitivity. Initially, gold-doped MIP (Au@MIP) film was constructed by electropolymerizing p-aminobenzoic acid (PABA) and BPA with in situ gold reduction to distribute gold nanoparticles nearby the imprinted cavities. Subsequently, the template molecules were further extracted from the polymer film, then the MIP could rebind with the template molecules to achieve specific detection of BPA. The nano gold-doped MIP increased the effective surface area and promoted conductivity when BPA was oxidized in the imprinted cavities, which improved the determination sensitivity. Under optimal conditions, the prepared sensor displayed a linear range from 0.5 to 100 μM for BPA detection with a detection limit of 52 nM. The designed sensor was further used to detect BPA in food samples, obtaining satisfactory recoveries from 96.7% to 107.6%.

Impacts on the short-term outcome of patients with Tako-Tsubo syndrome

Background

Tako-Tsubo syndrome (TTS) is a form of acute heart failure which mostly affects postmenopausal women, often following an emotional or physical trigger factor. There are many hypotheses for the development of TTS but the complete pathophysiology still remains unclear. Although most patients recover after a few days, some have to be treated at the intensive care unit (ICU) and may even die from the condition.

Purpose

The aim of this study was to find out if pre-existing diseases, cardiovascular risk factors (CVRF), comorbidities and trigger factors have any impact on the short-term outcome of TTS patients.

Methods

Data of all patients who presented to our centre with TTS from 2009–2017 were gathered retrospectively. Baseline characteristics, including somatic and psychiatric pre-existing diseases, CVRF (smoking, hypertension, diabetes, dyslipidaemia) as well as physical and emotional trigger factors were collected. Somatic diseases were additionally categorised into cardiac, autoimmune, malignant and other diseases. Admission to intensive care unit post TTS and/or in-hospital death were defined as poor short-term outcome. Outcome predictors were analysed with binary logistic regression model using the combined variable admission to an ICU and/or death.

Results

Out of 102 patients, 84 (82.4%) were females and 18 (17.6%) males with a median age of 65±15 years. 30 (29.4%) patients had an emotional and 23 (22.5%) a physical trigger factor. 27 (26.5%) had a psychiatric and 88 (86.3%) a somatic pre-existing disease. 33 (32.4%) patients were smokers, 58 (56.3%) had hypertension and 18 (17.5%) were diabetics. 19 patients (18.6%) had to be admitted to ICU and 8 patients (7.8%) died.

No pre-existing diseases, baseline characteristics, CVRF or comorbidities behaved as significant independent predictor for bad outcome in TTS patients. Physical trigger was the only significant predictor for ICU admission and/or death (p=0.012).

Conclusion

Our study showed that patients with physical trigger factors have a higher risk of ICU admission and/or death than patients with emotional or no stressful trigger factors before TTS and should therefore be monitored closely. Interestingly, contrary to many other acute cardiac diseases, pre-existing diseases, cardiovascular risk factors and comorbidities do not seem to have any impact on the short-term outcome of patients with TTS.

Funding Acknowledgement

Type of funding sources: None.

Elevated high-sensitivity C-reactive protein and the risk for cardiovascular events in chronic cardiac disease

Background

High sensitivity C-reactive protein (hs-CRP) is a biomarker used for risk prediction for cardiovascular disease by assessing low concentration of inflammation. This study aims to assess the event-free time for the composite outcome between patients of different hs-CRP risk groups and the possible predictive value of hs-CRP for event occurrence in patients with chronic cardiac disease.

Methods

Data from 607 consecutive patients referred for cardiovascular risk assessment with hs-CRP from November 2017 to October 2018 were reviewed retrospectively. Routine peripheral venous blood samples were taken on the day of study inclusion and sent to the local laboratory, where laboratory parameters were analyzed and processed in accordance with local laboratory standards. 570 patients who had hs-CRP measurement by immunoturbidimetric assay were included in the analysis and classified into three (low-, medium- and high-risk) groups (hs-CRP cut-off: <1, 1–3, >3 mg/L). Association between hs-CRP and occurrence of the composite outcome (acute myocardial infarction, stroke, coronary intervention (percutaneous coronary intervention or bypass surgery) or death) was determined with Cox regression analysis and visualized with Kaplan Meier curves.

Results

In total, 570 patients from our cardiology outpatient clinic were included in this study. Cohorts were formed according to hs-CRP risk groups, 209 (36.7%), 226 (39.6%) and 135 (23.7%) patients were classified as low-, medium- and high-risk, respectively. The composite endpoint occurred in 93 (19.1%) of the 486 patients with available follow-up. Events occurred in 29 (16.3%), 30 (15.7%), 34 (29.1%) patients of the low-, medium- and high-risk group, respectively (p=0.016). There was a significant difference in the event-free survival time patients of the low- and medium-risk groups compared with patients in the high-risk group (p=0.015). The difference between groups is shown by the Kaplan-Meier plot (log rank test, p=0.01) (Figure 1). Univariate Cox proportional-hazard analysis identified age, hs-CRP risk group, hypertension, diabetes, hyperlipidemia, coronary artery disease, peripheral artery disease, cerebrovascular disease log(NT-proBNP) and creatinine as significant predictors for the primary study outcome. In multivariable analysis coronary artery disease and age were found to be highly significant predictors for the occurrence of an composite event during follow-up, while patients categorized in the low- and medium-risk groups appeared to predict a lower likelihood for events (Table 1).

Conclusions

Cardiovascular events were more likely to occur in patients who were older, with hs-CRP >3 mg/L and a history of coronary artery disease. However, assessment of inflammation markers alone may play a secondary role compared to other established cardiovascular risk factors, elevated CRP appears helpful to detect higher risk and in prediction of further cardiovascular events and mortality.

Funding Acknowledgement

Type of funding sources: None.

Temporal evolution of the key neurohumoral regulator renin in chronic stable HFrEF

Background

Renin is the enzyme catalyzing the rate-limiting step of the Renin-Angiotensin-System (RAS) generating Angiotensin II (AngII). RAS inhibitors are a main pillar of current heart failure with reduced ejection fraction (HFrEF). Although used since over 30 years in clinical routine, the studied effects of RAS-inhibitors on renin level changes during the course of HFrEF and its impact on patient outcomes, especially under current guideline directed medical therapy (GDMT), are lacking.

Methods

Consecutive patients with stable chronic HFrEF and GDMT were enrolled prospectively from the our outpatient unit of heart failure between 06/2013 and 08/2021. Active plasma renin concentration (ARC) was documented for all patients consecutively at first measurement, i.e. baseline (BL), and at follow-up (FUP) visits at 12, 24, 36, 48 and 60 months, respectively. BL renin was correlated with N-terminal pro B-type natriuretic peptide (NT-proBNP) and compared between NYHA class, HF medication use and renin levels between baseline and FUP timepoints. To assess the effect of changes in renin levels, patients were categorized into three groups based on the change of renin from baseline within the first year of observation: decrease = change >−50%, undulating=change between −50 to 50%, increase=change>50% and survival curves were displayed as Kaplan-Meier plots and compared for different ARC categories by the log-rank test.

Results

A total of 491 patients were included in the study. BL characteristics are shown in Table1. Renin levels showed no relationship with HF severity reflected by a lack of correlation with NT-proBNP [rs=−0.05, p=0.273] and comparable levels between NYHA groups [p=0.753] (Figure 1A). Renin levels were further comparable for different RAS inhibitors and patients with and without beta blockers, however higher in patients with mineralocorticoid receptor antagonists (MRA) [189 μIE/ml vs. 59 μIE/ml, p=0.0001] and SGLT2-inhibitors [280 μIE/ml vs. 100 μIE/ml, p=0.004] (Figure 1B). Renin levels at different yearly FUP timepoints are displayed in Figure 1C. There was no significant difference in renin levels between BL and 1-year FUP, while renin concentration was increased at 2-year FUP [126 μIE/ml vs. 243 μIE/ml, p=0.002]. Baseline renin levels were not associated with survival [crude HR for an increase of 100μiE/ml 1.014 (95% CI: 0.997–1.032), p=0.102]. Within one year following BL, renin decreased in 77 (27.6%), was undulating in 74 (26.5%) and increased in 128 (45.9%) patients. Kaplan-Meier suggests worse survival for patients with increasing renin though the difference was statistically not significant [p=0.2573] (Figure 1D).

Conclusion

Renin was elevated in patients with MRA and/or SGLT2-inhibitors. Renin tends to increase over time in stable HFrEF. Although RAS is the main target of HFrEF therapy, surprisingly there seems to be no strong association between RAS activation and thereby potential effectivity of achieved RAS-blockade and outcome.

Funding Acknowledgement

Type of funding sources: None.

Electrochemical Self-Assembled Gold Nanoparticle SERS Substrate Coupled with Diazotization for Sensitive Detection of Nitrite

The accurate determination of nitrite in food samples is of great significance for ensuring people's health and safety. Herein, a rapid and low-cost detection method was developed for highly sensitive and selective detection of nitrite based on a surface-enhanced Raman scattering (SERS) sensor combined with electrochemical technology and diazo reaction. In this work, a gold nanoparticle (AuNP)/indium tin oxide (ITO) chip as a superior SERS substrate was obtained by electrochemical self-assembled AuNPs on ITO with the advantages of good uniformity, high reproducibility, and long-time stability. The azo compounds generated from the diazotization-coupling reaction between nitrite, 4-aminothiophenol (4-ATP), and N-(1-naphthyl) ethylenediamine dihydrochloride (NED) in acid condition were further assembled on the surface of AuNP/ITO. The detection of nitrite was realized using a portable Raman spectrometer based on the significant SERS enhancement of azo compounds assembled on the AuNP/ITO chip. Many experimental conditions were optimized such as the time of electrochemical self-assembly and the concentration of HAuCl₄. Under the optimal conditions, the designed SERS sensor could detect nitride in a large linear range from 1.0 × 10^-6 to 1.0 × 10^-3 mol L^-1 with a low limit of detection of 0.33 μmol L^-1. Additionally, nitrite in real samples was further analyzed with a recovery of 95.1-109.7%. Therefore, the proposed SERS method has shown potential application in the detection of nitrite in complex food samples.

Agreement between high-sensitivity C-reactive protein and C-reactive protein assays

Background

High sensitivity C-reactive protein (hs-CRP) is a biomarker used for risk prediction for cardiovascular disease (CVD) by assessing low concentrations of inflammatory markers. Measurements of regular CRP assays have become very sensitive too with a detection limit of 0.03mg/dL, while also being more available and cheaper. The aim of this study is to compare the association between CRP and hs-CRP.

Methods

This study compared CRP and hs-CRP serum concentrations and data acquired by medical chart review of 590 patients from 11/2017 to 10/2018 of our cardiology outpatient clinic who were divided into hs-CRP and CRP risk groups for CVD events: low<0.1 mg/dL, average 0.1–0.3mg/dL, high>0.3mg/dL. The agreement of classification in hs-CRP and CRP risk groups was assessed by kappa statistic, with Kappa coefficient of <0.20, 0.21–0.40, 0.41–0.60, 0.61–0.80, 0.81–0.99 interpreted as slight, fair, moderate, substantial and almost perfect agreement, respectively. Bland-Altman (BA) analysis was used to assess agreement between hs-CRP and CRP by plotting the mean of the two measurements on the x-axis against the mean difference of CRP - hs-CRP on the y-axis.

Results

Out of all 590 patients, 37.7% were in low risk, 33.9% in average risk and 28.5% in high risk hs-CRP group. Some group changes occurred after reclassification of the patients according to CRP measurements. Eight percent of patients reclassified into a higher risk group, 0.7% into a lower risk group, while 91.4% remained in the same risk group as determined by hs-CRP (kappa: 0.87; p<0.001) (Tab. 1). Important to note, there was a 100% agreement between the high-risk CRP and hs-CRP group patient classification. BA-plot displayed a fixed bias with an average difference between the two laboratory tests for CRP and hs-CRP of 0.02 mg/dL±0.09SD with only sporadic outliers (Fig. 1). The upper limit of agreement was 0.12 and lower limit of agreement was −0.07. In the lower range of CRP values, measurements were tightly clustered around the average difference. Greater variability could be observed at higher serum level of the inflammatory biomarker in the BA-plot with a bias to higher CRP concentrations than hs-CRP concentrations at values greater than 0.5mg/dL. This proportional bias, which was further demonstrated by linear regression analysis, does not affect the risk predicting qualities of hs-CRP or CRP for CVD because the cut-off values for risk groups (0.1mg/dL for low risk, 0.3mg/dL for high risk) are all below this threshold.

Conclusion

A close agreement between measurements of hs-CRP and CRP assays was identified, therefore regular CRP assays could replace hs-CRP for cardiac risk assessment. Benefits for clinical implementation are: First, CRP assessment is routinely available in most laboratories compared to hs-CRP. Second, CRP is less costly than hs-CRP, since no further laboratory acquisitions are necessary, which is especially relevant in regions where cost efficiency is of importance.

Funding Acknowledgement

Type of funding sources: None. Table 1. Kappa statisticFigure 1. Bland-Altman plot

Development of Highly Sensitive Immunosensor for Detection of Staphylococcus aureus Based on AuPdPt Trimetallic Nanoparticles Functionalized Nanocomposite

The rapid and sensitive detection of Staphylococcus aureus (S. aureus) is essential to ensure food safety and protect humans from foodborne diseases. In this study, a sensitive and facile electrochemical immunosensor using AuPdPt trimetallic nanoparticles functionalized multi-walled carbon nanotubes (MWCNTs-AuPdPt) as the signal amplification platform was designed for the label-free detection of S. aureus. The nanocomposite of MWCNTs-AuPdPt was prepared by an in situ growth method of loading AuPdPt trimetallic nanoparticles on the surface of MWCNTs. The synthesized MWCNTs-AuPdPt featured good conductivity and superior catalytic performance for hydrogen peroxide. The nanocomposite of MWCNTs-AuPdPt with good biocompatibility and high specific surface area was further functionalized by anti-S. aureus antibodies. The immobilized antibodies could efficiently capture S. aureus to the modified electrode by an immune reaction, which resulted in the change of catalytic current intensity to realize the sensitive detection of S. aureus. The designed immunosensor could detect S. aureus in a linear range from 1.1 × 102 to 1.1 × 107 CFU mL-1 with a low detection limit of 39 CFU mL-1. Additionally, the proposed immunosensor was successfully applied to determine S. aureus in actual samples with acceptable results. This strategy provided a promising platform for highly sensitive determination of S. aureus and other pathogens in food products.

Quantitative analysis of colony number in mouldy wheat based on near infrared spectroscopy combined with colorimetric sensor

Current work presented a novel method based on colorimetric sensor (CS) combined with visible/near-infrared spectroscopy (VNIRs) for the detection of volatile markers in wheat infected by Aspergillus glaucus. Wheat samples with different mouldy degree was cultivated for backup under temperature of 25-28 °C in incubator. The total colony number was determined by flat colony counting method. Through employing chemo-responsive dyes including 8-(4-nitrophenyl)-4, 4-difluoro-BODIPY (NO₂BDP), 8-(4-bromophenyl)-4,4-difluoro-BODIPY(BrBDP) and 8-phenyl-4,4-difluoro- BODIPY(HBDP) as capture probes of colorimetric sensor for volatile organic compounds (VOCs). The spectral data of CS-VNIRs were scanned and used to build synergic interval partial least squares (Si-PLS) models. The optimized Si-PLS model based on HBDP sensor gave a better detection performance, and the correlation coefficient of the prediction set Rp = 0.9387. The achieved high correlation rates imply that the technique may be deployed as a panacea to identify and quantify the colony number of different mouldy wheat.

Simple electrochemical sensing for mercury ions in dairy product using optimal Cu2+-based metal-organic frameworks as signal reporting

A convenient sensor is developed for electrochemical assay of Hg²⁺ in dairy product using the optimal Cu²⁺-based metal-organic frameworks (Cu-MOFs) as signal reporting. Benefiting from specific recognition between Hg²⁺ and thymine (T)-rich DNA strands, the interferences of milk matrices are effectively eliminated, thereby greatly improving the accuracy of test results. Moreover, the suitable Cu-MOFs offer an efficient carrier for probe design, and the contained Cu²⁺ ions could be directly detected to output electrochemical signal of Hg²⁺ presence without labor- or time-intensive operations. Compared with previous methods, this sensor substantially simplifies the process of electrochemical measurement and facilitates highly sensitive, selective and rapid analysis of Hg²⁺ with detection limit of 4.8 fM, offering a valuable means for monitoring dairy product contamination with Hg²⁺.

Impact of overweight or obesity trajectory on health expenditure in Korea

BACKGROUND

This study aimed to identify the effect of the overweight or obesity (OWOB) trajectory on current health care expenditure in South Korea.

METHODS

Ten years of publicly released data (2002-12) were obtained in 2016 from a retrospective cohort of National Health Insurance System claims. This study included 51,844 adults (aged 30-59 years in 2002) and 21,196 elderly adults (aged ≥ 60 years in 2002).

RESULTS

Compared with adults who maintained normal weight (NW), higher yearly total health expenditures were estimated for adults who lost weight over the 10-year period: by 11.5% (95% confidence interval (CI): 0.18-22.96%) when changing from NW to underweight (UW) and 6.2% (95% CI: 0.47-12.01%) from OWOB to UW/NW. Elderly adults had higher health expenditures when they lost weight by 14.0% (95% CI: 0.37-27.70%) from NW to UW and 6.8% (95% CI: 0.13-13.51%) from OWOB to UW/NW compared with when they maintained NW.

CONCLUSIONS

These findings indicate the importance of early intervention to control OWOB, particularly because people in late adulthood have greater health care needs for reasons other than OWOB.

The incidence and seasonal variation of necrotizing fasciitis in Korea: a nationwide cross-sectional study

INTRODUCTION

Necrotizing fasciitis (NF) is a rare but fatal disease, and there is no known annual incidence of NF in Korea. The aim of this study was to investigate the incidence and seasonal variation of NF in Korea.

METHODS

We analysed claims from the nationwide Korean Health Insurance Review and Assessment Service database. Patients who were hospitalized with an NF diagnosis code and received surgical intervention were classified as NF cases. Poisson regression models were used to assess the relationships of incidence rates with year, age and sex. A multivariate Poisson regression model was used to investigate variations in monthly NF incidence trends.

RESULTS

From 2012 to 2017, the overall average annual NF incidence rate was found to be 0.86 per 100 000 population. NF incidence increased with age and was 2.5 times higher among males across all age groups. Two-thirds of cases occurred among patients with diabetes. The peak NF incidence occurred during the summer. Multivariate Poisson regression modelling using national meteorological variables suggested that mean temperatures and number of NF cases in the previous month were associated with the number of NF cases in the current month.

DISCUSSION

Clinicians should consider NF when encountering an elderly man with diabetes during the summer.

P869 Effect of transcatheter MitraClip implantation on exercise performance evaluated by CPET

Methods

Total body bone scintigraphy, 714 MBq 99m-Tc DPD, was performed to confirm the diagnosis of cardiac transthyretin (ATTR) amyloidosis. The extent of mitral regurgitation was assessed using TTE and TEE before and after MC implantation. Coronary angiography and right heart catheterization were performed prior to MC implantation. CPET by a cycle ergometer was used to measure the dynamic response of the heart before and after the procedure. A ramp protocol, adapted to reach maximal capacity after 8-10 min was chosen for the test. The parameter of main interest was maximal oxygen uptake (VO2 max, ml/min), the major factor known to limit exercise capacity.

Results

Bone scan showed tracer accumulation in myocardial tissue, genetic testing was negative which confirmed wild type cardiac transthyretin (ATTR) amyloidosis. Significant coronary artery disease was excluded by coronary angiography. Right heart catheterization disclosed post capillary pulmonary hypertension: mean pulmonary artery pressure of 42 mmHg and mean pulmonary capillary wedge pressure of 25 mmHg and end-diastolic pressure of left ventricle of 118 mmHg. A high grade left ventricular concentric hypertrophy (IVS = 26mm) with slightly reduced left systolic function, a severe MR (EROA = 35 mm2) and enlargement of left and right atria (LA = 68mm, RA = 68mm) were demonstrated by TTE. In TEE left atrium including left atrial appendage were free from thrombi; high grade left ventricular hypertrophy, restriction of posterior leaflet and severe MR with eccentric jet with dilated annulus were demonstrated. CPET before MC implantation: VO2 max 1299 ml/min (83% of predicted peak oxygen uptake value). MC implantation was performed with no post-procedural complications. Follow-up CPET showed higher VO2 max 1373 ml/min compared to the data before MC implantation (88% predicted peak oxygen uptake value).

Conclusions

TTE and TEE are the most common and accurate imaging modalities to evaluate MR regarding MitraClip evaluation. After the MC procedure the dynamic response of the heart can be observed by CPET with VO2 as a surrogate marker for heart function.

Abstract P869 Figure. a.b. TEE prior to MC, c.d. TEE after MC

P974 Sacubitril/valsartan is well tolerated in patients with heart failure and a history of cancer

Introduction

Sacubitril/valsartan has been shown to significantly reduce cardiovascular mortality and hospitalisations due to heart failure in patients with reduced ejection fraction when compared to enalapril. Until now, sacubitril/valsartan has not been evaluated in patients with a history of cancer, as these patients were excluded from the pivotal trial, PARADIGM-HF. The aim of the current study was to assess tolerability of sacubitril/valsartan in patients with a history of cancer.

Methods

We retrospectively enrolled all patients at our heart failure out-patient unit who fulfilled the indication criteria to receive sacubitril/valsartan and had a history of cancer. Fifteen patients receiving sacubitril/valsartan had a diagnosis of histologically confirmed cancer: 26.7% breast cancer (n = 4), 13.3% osteosarcoma (n = 2), 13.3% colorectal cancer (n = 2), 13.3% renal cell carcinoma (n = 2), 6.7% non-Hodgkin lymphoma (n = 1), 6.7% lung cancer (n = 1), 6.7% prostate cancer (n = 1), 6.7% bladder carcinoma and 6.7% myeoloproliferative syndrome (n = 1). Surgery due to cancer was performed in 80% of patients (n = 12), 26.7% previously received chemotherapy (n = 6) and 40% radiation therapy (n = 4).

Results

Sacubitril/valsartan was withdrawn in 2 patients (13.3%) because of dizziness and pruritus respectively. After a mean follow-up of 13 ±8 months, NYHA functional class improved significantly (mean -0.5, p = 0.001), ejection fraction as assassed by echocardiography increased (mean +6.8%, p = 0.018) and NT-proBNP was significantly decreased (mean -1552pg/ml, p = 0.026). There was no significant change in creatinine levels (+0.046 mg/dl, p = 0.564 ).

Conclusions

In this pilot study we were able to show that sacubitril/valsartan is generally well tolerated in patients with a history of cancer. Patients with cardiotoxicity induced heart failure can be treated and uptitrated with sacubitril/valsartan to usual dosages similarly as in other causes of heart failure. Larger studies are needed to confirm these findings in cancer patients with cardiotoxicity.

Abstract P6-02-01: Not presented

This abstract was not presented at the conference.

Citation Format: Luo J, Chen Q, Tang L, Yang L, Han E, Chen Y, Yuan L. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-02-01.

Structure-Switching Electrochemical Aptasensor for Single-Step and Specific Detection of Trace Mercury in Dairy Products

A reagentless and single-step electrochemical aptasensor with separation-free fashion and rapid response is developed for the Hg²⁺ assay in dairy products. Herein, the sensing strategy is established on Hg²⁺-induced structural transition of the methylene-blue-tagged single-stranded DNA (ssDNA) from a flexible manner to rigid hairpin-shaped double-stranded DNA (dsDNA), generating an improved peak current for the Hg²⁺ assay with a detection limit of 0.62 fM. Importantly, the best signal-to-noise ratio value can be obtained by exploiting Au flowers as sensing material and the optimal ssDNA concentration. The proposed sensor also exhibits high selectivity as a result of the specific thymine-Hg²⁺-thymine (T-Hg²⁺-T) coordination chemistry and can be applied to detect Hg²⁺ in dairy products. With the use of the electric "signal-on" switch, the electrochemical aptasensor has the advantages of simplicity, ease of operation, and high sensitivity and specificity, offering a promising method to assess the safety of dairy products polluted with Hg²⁺.

Effects of fumonisin B1 and mycotoxin binders on growth performance, tibia characteristics, gut physiology, and stress indicators in broiler chickens raised in different stocking densities

The present study was carried out to investigate the effects of stocking density, fumonisin B1 (FB), and mycotoxin binder (TB) on growth performance, bone quality, physiological stress indicators, and gut health in broiler chickens. Day-old Ross 308 male broiler chicks (n = 1,440/experiment) were randomly allocated to 72 floor pens in a 3 × 2 × 2 factorial arrangement, using 3 stocking densities (12.5 birds/m2 [HSD], 10 birds/m2 [MSD], or 7.5 birds/m2 [LSD]), 2 levels of purified FB (0 or 10 ppm), and 2 levels of TB (0 or 0.2%). Each treatment had 6 replicates (n = 6/treatment) and experiments lasted 34 days. All data were analyzed using 3-way ANOVA with stocking density level, FB, and TB as main factors. Body weight gain and feed intake were lower (P < 0.05) in broilers kept at HSD and MSD compared to LSD-housed counterparts. Birds fed an FB-contaminated diet exhibited a higher feed-to-gain ratio compared with those fed an FB-free diet (P < 0.05). None of the treatments affected intestinal morphology or ileal secretory immunoglobulin A levels. Stocking density affected tibia breaking strength (P < 0.05), which was lower in chickens housed at HSD compared with LSD-housed chickens. The heterophil/lymphocyte ratio (H/L ratio) was elevated (P < 0.05) in HSD and MSD groups compared with the LSD group. Serum nitric oxide (NO) levels were elevated (P < 0.05) in chickens fed the FB-contaminated diet compared with the control diet-fed counterparts. Significant interaction (P < 0.05) between FB and TB on serum NO levels was noted. In summary, increasing stocking density lowered growth performance and bone quality, but increased the H/L ratio. Dietary TB did not affect FB-induced increases in the feed-to-gain ratio. No interaction was observed between stocking density and FB for the measured variables.

Sarcopenia is associated with the risk of significant liver fibrosis in metabolically unhealthy subjects with chronic hepatitis B

BACKGROUND

Sarcopenia is significantly associated with the degree of liver fibrosis. This study investigated the influence of sarcopenia on liver fibrosis in individuals with chronic hepatitis B.

METHODS

Data from the Korean National Health and Nutrition Examination Surveys 2008-2011 were analysed. The sarcopenia index (total appendicular skeletal muscle mass [kg]/body mass index [kg/m² ]) was calculated using dual-energy X-ray absorptiometry. Sarcopenia was defined as the lowest quintile sarcopenia index value (cut-offs: 0.89 for men and 0.58 for women). The fibrotic burden was assessed using the nonalcoholic fatty liver disease fibrosis score and fibrosis-4 index. Significant fibrosis was defined as the highest nonalcoholic fatty liver disease fibrosis score quartile and a fibrosis-4 index ≥2.67.

RESULTS

Among the 506 respondents with chronic hepatitis B (258 men and 248 women), the nonalcoholic fatty liver disease fibrosis score and fibrosis-4 index identified sarcopenia and significant fibrosis in 126 (24.9%) and 217 (42.9%), respectively. Sarcopenia was significantly associated with significant fibrosis, regardless of the fibrosis prediction model used (all P < 0.05). When the study population was stratified according to metabolic factors, sarcopenia was specifically associated with an increased risk of significant fibrosis among subgroups with obesity, insulin resistance, metabolic syndrome and liver steatosis (odds ratio 2.37-3.57; all P < 0.05). An independent association between sarcopenia and significant fibrosis was identified after adjusting for other confounders (odds ratio 2.67-3.62 by the nonalcoholic fatty liver disease fibrosis score and 2.04-2.62 by the fibrosis-4 index; all P < 0.05).

CONCLUSIONS

Sarcopenia is associated with significant fibrosis in subjects with chronic hepatitis B, specifically those with obesity, insulin resistance, metabolic syndrome and liver steatosis.

A homogeneous assay for highly sensitive detection of CaMV35S promoter in transgenic soybean by förster resonance energy transfer between nitrogen-doped graphene quantum dots and Ag nanoparticles

In this work, a novel homogeneous assay for DNA quantitative analysis based on förster resonance energy transfer (FRET) was developed for cauliflwer mosaic virus 35s (CaMV35S) promoter of transgenic soybean detection. The homogenous FRET of fluorescence signal was fabricated by DNA hybridization with probe modified nitrogen-doped graphene quantum dots (NGQDs) and silver nanoparticles (AgNPs), which acted the donor-acceptor pairs for the first time. The highly efficient FRET and unique properties of the NGQDs made the proposed FRET system as a functionalized detection platform for labelling of DNA. Upon the recognition of specific target DNA (tDNA), the FRET between NGQDs and AgNPs was triggered to produce fluorescence quenching, which could be used for tDNA detection. The fabricated homogeneous FRET assay displayed a wide linear range of 0.1-500.0 nM and a low limit of detection 0.03 nM for the detection of CaMV35S (S/N = 3). This proposed biosensor revealed high specificity to detect tDNA, with acceptable intra-assay precision and excellent stability. This method was successfully applied to identify the real sample of 0.5% containing transgenic soybean, which achieved the most of national law regulations. This assay was further validated by polymerase chain reaction as the genetically modified organisms, suggesting that the proposed FRET system is a feasible tool for the further daily genetically modified organism detection.

Low-income African-American adults share weight status, food-related psychosocial factors and behaviours with their children

Objective

This study aims to examine the extent to which low‐income African‐American children's weight status, psychosocial characteristics and food‐related behaviours are associated with that of their adult caregivers.

Methods

Cross‐sectional data from baseline evaluation of B'More Healthy Communities for Kids obesity prevention trial were used. Outcomes of interest were children's overweight and/or obesity status, food‐related self‐efficacy, knowledge, intentions and healthier/less healthy food acquisition scores. The primary exposures were adult caregiver's overweight and/or obesity status, their psychosocial factors and food acquisition scores. Multiple logistic regression analyses were used to assess associations.

Results

Children had higher odds of overweight or obesity if they had an overweight/obese caregiver (odds ratio [OR] 4.04, 95% confidence interval [95%CI] 1.59–10.28) or an obese caregiver (OR 2.50, 95%CI 1.39–4.51). Having a caregiver in the highest quartile of self‐efficacy, food intentions and healthy food acquisition patterns was associated with higher odds of their child also having a higher score on these factors (self‐efficacy: OR 3.77 [95%CI 1.76–8.04]; food intentions: OR 1.13 [95%CI 1.01–1.27]; and healthy food acquisition: OR 2.19 [95%CI 1.05–4.54]).

Conclusions

Child and adult caregiver weight status and psychosocial characteristics were positively associated in this low‐income, urban population. These findings may help inform obesity treatment or prevention programmes and interventions aimed at parents and families.

Photoelectrochemical CaMV35S biosensor for discriminating transgenic from non-transgenic soybean based on SiO2@CdTe quantum dots core-shell nanoparticles as signal indicators

A methodology for detection of the Cauliflower Mosaic Virus 35S(CaMV35S) promoter was developed to distinguish transgenic from non-transgenic soybean samples by using photoelectrochemical (PEC) biosensor. In this PEC biosensing system, the as-prepared gold nanoparticles-reduced graphene oxide acted as a nanocarrier to immobilize the thiol-functional probe (probe1), and the SiO₂@CdTe quantum dots (QDs) core-shell nanoparticles tagged with the amino-functional probe (probe2) acted as signal indicators, respectively. In the presence of target DNA (tDNA) of CaMV35S, the binding of tDNA with probe1 and probe2 through the high specific DNA hybridization led to the fabrication of sandwich structure, and thus the high loading of the signal indicators SiO₂@CdTe QDs at the electrode surface, which increased the PEC signal. The increased PEC signal depended on the concentration of tDNA, and a wide linear range from 0.1pM to 0.5nM with low detection limit of 0.05pM was obtained. In addition, the PEC biosensor has been successfully used for discriminating transgenic soybean from non-transgenic samples, which was consistent with the polymerase chain reaction (PCR) results, suggesting the proposed PEC biosensor is a feasible tool for the further daily genetically modified organism detection.

Optimized dendrimer-encapsulated gold nanoparticles and enhanced carbon nanotube nanoprobes for amplified electrochemical immunoassay of E. coli in dairy product based on enzymatically induced deposition of polyaniline

A highly sensitive immunosensor was reported for Escherichia coli assay in dairy product based on electrochemical measurement of polyaniline (PAn) that was catalytically deposited by horseradish peroxidase (HRP) labels. Herein, the immunosensor was developed by using poly(amidoamine) dendrimer-encapsulated gold nanoparticles (PAMAM(Au)) as sensing platform. Importantly, the optimal HAuCl4/PAMAM ratio was investigated to design the efficient PAMAM(Au) nanocomposites. The nanocomposites were proven to not only increase the amount of immobilized capture antibody (cAb), but also accelerate the electron transfer process. Moreover, the {dAb-CNT-HRP} nanoprobes were prepared by exploiting the amplification effect of multiwalled carbon nanotubes (CNTs) for loading detection antibody (dAb) and enormous HRP labels. After a sandwich immunoreaction, the quantitatively captured nanoprobes could catalyze oxidation aniline to produce electroactive PAn for electrochemical measurement. On the basis of signal amplification of the PAMAM(Au)-based immunosensor and the {dAb-CNT-HRP} nanoprobes, the proposed strategy exhibited a linear relationship between the peak current of PAn and the logarithmic value of E. coli concentration ranging from 1.0 × 10(2) to 1.0 × 10(6) cfu mL(-1) with a detection limit of 50 cfu mL(-1) (S/N=3), and the electrochemical detection of E. coli could be achieved in 3h. The electrochemical immunosensor was also used to determine E. coli in dairy product (pure fresh milk, infant milk powder, yogurt in shelf-life and expired yogurt), and the recoveries of standard additions were in the range of 96.8-108.7%. Overall, this method gave a useful protocol for E. coli assay with high sensitivity, acceptable accuracy and satisfying stability, and thus provided a powerful tool to estimate the quality of dairy product.

POST-HARVEST EMBRYO DEVELOPMENT IN GINSENG SEEDS INCREASES DESICCATION SENSITIVITY AND NARROWS THE HYDRATION WINDOW FOR CRYOPRESERVATION

BACKGROUND

Despite its self-pollinating characteristics, Korean ginseng germplasm is mainly maintained in clonal gene banks as there is no defined approach to the long-term conservation of its seed, including the most appropriate stage of embryo development for storage.

OBJECTIVE

The aim of this study was to reveal the effect of embryo development on desiccation tolerance and cryopreservation success in ginseng seeds.

MATERIALS AND METHODS

Seeds of Korean ginseng (Panax ginseng C.A. Meyer) at three post-harvest stages (immediately after harvesting and following treatments to enable internal growth of the embryo) were desiccated and cryopreserved.

RESULTS

The hydration window for the >80% dehiscence and germination of cryopreserved ginseng seeds varied with embryo developmental stage: 3-9% moisture content (MC) for both unpulped and undehisced seeds when the embryo was 0.1 the length of the endosperm, 7-10% MC for dehisced seeds (0.5 embryo:endosperm) and 9-11% MC for seeds with fully developed embryos (0.9 embryo:endosperm). Whilst dried (4-8% moisture content) and undehisced seeds within fruits (unpulped seeds) lost more than half their viability during 1 year's storage at room temperature, cryopreservation enabled germination levels of c. 90%. Overall, 432 accessions of Korean ginseng landraces have been cryopreserved using undehisced seeds with or without fruits.

CONCLUSION

Post-harvest treatment of Korean ginseng seeds to enable embryo development decreases tolerance of very low MCs, and thus narrows the hydration window for cryopreservation. Fresh-harvested and unpulped seeds that have been dried to c. 5% MC are recommended for long-term cryogenic storage.

Carbohydrate derivative-functionalized biosensing toward highly sensitive electrochemical detection of cell surface glycan expression as cancer biomarker

Accurate and highly sensitive detection of glycan expression on cell surface is extremely important for cancer diagnosis and therapy. Herein, a carbohydrate derivative-functionalized biosensor was developed for electrochemical detection of the expression level of cell surface glycan (mannose used as model). Thiomannosyl dimer was synthesized to design the thiomannosyl-functionalized biosensor by direct and rapid one-step protocols. The biosensing surface-confined mannose could effectively mimic the presentation of cell surface mannose and was responsible for competing with mannose on cancer cells in incubation solution. Greatly enhanced sensitivity was achieved by exploiting the excellent conductivity of multiwalled carbon nanotube/Au nanoparticle (MWNT/AuNP), the amplification effect of MWNTs, and the favorable catalytic ability of horseradish peroxidase (HRP). Using competitive strategy, the developed biosensor exhibits attractive performances for the analysis of mannose expression with rapid response, high sensitivity and accuracy, and possesses great promise for evaluation of cell surface glycan expression by using a greater variety of lectins.

A sensitive amperometric acetylcholine biosensor based on carbon nanosphere and acetylcholinesterase modified electrode for detection of pesticide residues

A sensitive biosensor based on acetylcholinesterase (AChE) and carbon nanosphere (CNS) immobilized on a glassy carbon electrode was developed for the detection of pesticides by the inhibition of AChE activity. The inhibition effect of the pesticides resulted in a decrease of current response of the acetylthiocholine chloride that was used as a substrate to obtain an electrochemical signal. When applied to the pesticides carbofuran and fenitrothion, the designed biosensor exhibited high sensitivity and low detection limits. The inhibition ratio of carbofuran and fenitrothion were linearly proportional to their concentrations ranging from 0.40 to 4.79 and 6.26 to 125.31 μg/L, respectively. The theoretical detection limits were found to be 0.082 μg/L for carbofuran and 2.61 μg/L for fenitrothion. Furthermore, as the biosensor offers good reproducibility and stability, it could be used for trace detection of pesticides in real samples. Compared with other AChE biosensors, the proposed biosensor was convenient and it exhibited extreme sensitivity to pesticides.