Incorporating longitudinal history of risk factors into atherosclerotic cardiovascular disease risk prediction using deep learning

It is increasingly clear that longitudinal risk factor levels and trajectories are related to risk for atherosclerotic cardiovascular disease (ASCVD) above and beyond single measures. Currently used in clinical care, the Pooled Cohort Equations (PCE) are based on regression methods that predict ASCVD risk based on cross-sectional risk factor levels. Deep learning (DL) models have been developed to incorporate longitudinal data for risk prediction but its benefit for ASCVD risk prediction relative to the traditional Pooled Cohort Equations (PCE) remain unknown. Our study included 15,565 participants from four cardiovascular disease cohorts free of baseline ASCVD who were followed for adjudicated ASCVD. Ten-year ASCVD risk was calculated in the training set using our benchmark, the PCE, and a longitudinal DL model, Dynamic-DeepHit. Predictors included those incorporated in the PCE: sex, race, age, total cholesterol, high density lipid cholesterol, systolic and diastolic blood pressure, diabetes, hypertension treatment and smoking. The discrimination and calibration performance of the two models were evaluated in an overall hold-out testing dataset. Of the 15,565 participants in our dataset, 2170 (13.9%) developed ASCVD. The performance of the longitudinal DL model that incorporated 8 years of longitudinal risk factor data improved upon that of the PCE [AUROC: 0.815 (CI 0.782-0.844) vs 0.792 (CI 0.760-0.825)] and the net reclassification index was 0.385. The brier score for the DL model was 0.0514 compared with 0.0542 in the PCE. Incorporating longitudinal risk factors in ASCVD risk prediction using DL can improve model discrimination and calibration.

Incorporating longitudinal history of risk factors into atherosclerotic cardiovascular disease risk prediction using deep learning

Background

It is increasingly clear that longitudinal risk factor levels and trajectories are related to risk for atherosclerotic cardiovascular disease (ASCVD) above and beyond single measures. Currently used in clinical care, the Pooled Cohort Equations (PCE) are based on regression methods that predict ASCVD risk based on cross-sectional risk factor levels. Deep learning (DL) models have been developed to incorporate longitudinal data for risk prediction but its benefit for ASCVD risk prediction relative to the traditional Pooled Cohort Equations (PCE) remain unknown.

Objective

To develop a ASCVD risk prediction model that incorporates longitudinal risk factors using deep learning.

Methods

Our study included 15,565 participants from four cardiovascular disease cohorts free of baseline ASCVD who were followed for adjudicated ASCVD. Ten-year ASCVD risk was calculated in the training set using our benchmark, the PCE, and a longitudinal DL model, Dynamic-DeepHit. Predictors included those incorporated in the PCE: sex, race, age, total cholesterol, high density lipid cholesterol, systolic and diastolic blood pressure, diabetes, hypertension treatment and smoking. The discrimination and calibration performance of the two models were evaluated in an overall hold-out testing dataset.

Results

Of the 15,565 participants in our dataset, 2,170 (13.9%) developed ASCVD. The performance of the longitudinal DL model that incorporated 8 years of longitudinal risk factor data improved upon that of the PCE [AUROC: 0.815 (CI: 0.782-0.844) vs 0.792 (CI: 0.760-0.825)] and the net reclassification index was 0.385. The brier score for the DL model was 0.0514 compared with 0.0542 in the PCE.

Conclusion

Incorporating longitudinal risk factors in ASCVD risk prediction using DL can improve model discrimination and calibration.

Metabolomic Profiling of Cholesterol Efflux Capacity in a Multiethnic Population: Insights From MESA

BACKGROUND

Impaired cholesterol efflux capacity (CEC) is a novel lipid metabolism trait associated with atherosclerotic cardiovascular disease. Mechanisms underlying CEC variation are unknown. We evaluated associations of circulating metabolites with CEC to advance understanding of metabolic pathways involved in cholesterol efflux regulation.

METHODS

Participants enrolled in the MESA (Multi-Ethnic Study of Atherosclerosis) who underwent nuclear magnetic resonance metabolome profiling and CEC measurement (N=3543) at baseline were included. Metabolite associations with CEC were evaluated using standard linear regression analyses. Repeated ElasticNet and multilayer perceptron regression were used to assess metabolite profile predictive performance for CEC. Features important for CEC prediction were identified using Shapley Additive Explanations values.

RESULTS

Greater CEC was significantly associated with metabolite clusters composed of the largest-sized particle subclasses of VLDL (very-low-density lipoprotein) and HDL (high-density lipoprotein), as well as their constituent apo A1, apo A2, phospholipid, and cholesterol components (β=0.072-0.081; P<0.001). Metabolite profiles had poor accuracy for predicting in vitro CEC in linear and nonlinear analyses (R2<0.02; Spearman ρ<0.18). The most important feature for CEC prediction was race, with Black participants having significantly lower CEC compared with other races.

CONCLUSIONS

We identified independent associations among CEC, the largest-sized particle subclasses of VLDL and HDL, and their constituent apolipoproteins and lipids. A large proportion of variation in CEC remained unexplained by metabolites and traditional clinical risk factors, supporting further investigation into genomic, proteomic, and phospholipidomic determinants of CEC.

Cigarette Smoking and Competing Risks for Fatal and Nonfatal Cardiovascular Disease Subtypes Across the Life Course

Background

Cigarette smoking is significantly associated with premature death related and not related to cardiovascular disease (CVD). Whether risk associated with smoking is similar across CVD subtypes and how this translates into years of life lost is not known.

Methods and Results

We pooled and harmonized individual‐level data from 9 population‐based cohorts in the United States. All participants were free of clinical CVD at baseline with available data on current smoking status, covariates, and CVD outcomes. We examined the association between smoking status and total CVD and CVD subtypes, including fatal and nonfatal coronary heart disease, stroke, congestive heart failure, and other CVD deaths. We performed (1) modified Kaplan–Meier analysis to estimate long‐term risks, (2) adjusted competing Cox models to estimate joint cumulative risks for CVD or noncardiovascular death, and (3) Irwin’s restricted mean to estimate years lived free from and with CVD. Of 106 165 adults, 50.4% were women. Overall long‐term risks for CVD events were 46.0% (95% CI, 44.7–47.3) and 34.7% (95% CI, 33.3–36.0) in middle‐aged men and women, respectively. In middle‐aged men who reported smoking compared with those who did not smoke, competing hazard ratios (HRs) were higher for the first presentation being a fatal CVD event (HR, 1.79 [95% CI, 1.68–1.92]), with a similar pattern among women (HR,1.82 [95% CI, 1.68–1.98]). Smoking was associated with earlier CVD onset by 5.1 and 3.8 years in men and women. Similar patterns were observed in younger and older adults.

Conclusions

Current smoking was associated with a fatal event as the first manifestation of clinical CVD.

Remnant cholesterol predicts cardiovascular disease beyond LDL and ApoB: a primary prevention study

AIMS

Emerging evidence suggests that remnant cholesterol (RC) promotes atherosclerotic cardiovascular disease (ASCVD). We aimed to estimate RC-related risk beyond low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B (apoB) in patients without known ASCVD.

METHODS AND RESULTS

We pooled data from 17 532 ASCVD-free individuals from the Atherosclerosis Risk in Communities study (n = 9748), the Multi-Ethnic Study of Atherosclerosis (n = 3049), and the Coronary Artery Risk Development in Young Adults (n = 4735). RC was calculated as non-high-density lipoprotein cholesterol (non-HDL-C) minus calculated LDL-C. Adjusted Cox models were used to estimate the risk for incident ASCVD associated with log RC levels. We also performed discordance analyses examining relative ASCVD risk in RC vs. LDL-C discordant/concordant groups using difference in percentile units (>10 units) and clinically relevant LDL-C targets. The mean age of participants was 52.3 ± 17.9 years, 56.7% were women and 34% black. There were 2143 ASCVD events over the median follow-up of 18.7 years. After multivariable adjustment including LDL-C and apoB, log RC was associated with higher ASCVD risk [hazard ratio (HR) 1.65, 95% confidence interval (CI) 1.45-1.89]. Moreover, the discordant high RC/low LDL-C group, but not the low RC/high LDL-C group, was associated with increased ASCVD risk compared to the concordant group (HR 1.21, 95% CI 1.08-1.34). Similar results were shown when examining discordance across clinical cutpoints.

CONCLUSIONS

In ASCVD-free individuals, elevated RC levels were associated with ASCVD independent of traditional risk factors, LDL-C, and apoB levels. The mechanisms of RC association with ASCVD, surprisingly beyond apoB, and the potential value of targeted RC-lowering in primary prevention need to be further investigated.

IgG Seroconversion and Pathophysiology in Severe Acute Respiratory Syndrome Coronavirus 2 Infection

We investigated the dynamics of seroconversion in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. During March 29-May 22, 2020, we collected serum samples and associated clinical data from 177 persons in London, UK, who had SARS-CoV-2 infection. We measured IgG against SARS-CoV-2 and compared antibody levels with patient outcomes, demographic information, and laboratory characteristics. We found that 2.0%-8.5% of persons did not seroconvert 3-6 weeks after infection. Persons who seroconverted were older, were more likely to have concurrent conditions, and had higher levels of inflammatory markers. Non-White persons had higher antibody concentrations than those who identified as White; these concentrations did not decline during follow-up. Serologic assay results correlated with disease outcome, race, and other risk factors for severe SARS-CoV-2 infection. Serologic assays can be used in surveillance to clarify the duration and protective nature of humoral responses to SARS-CoV-2 infection.

Association of a Serum Protein Signature With Rheumatoid Arthritis Development

OBJECTIVE

The pathophysiologic events that precede the onset of rheumatoid arthritis (RA) remain incompletely understood. This study was undertaken to identify changes in the serum proteome that precede the onset of RA, with the aim of providing new insights into the pathogenic mechanisms that lead to its development.

METHODS

In a cohort of first-degree relatives of Indigenous North American RA patients, the SomaScan proteomics platform was used to determine the levels of 1,307 proteins in multiple longitudinal serum samples from 17 individuals who were followed up prospectively to the time of disease onset. Proteomic signatures from this group of individuals (designated the progressor group) were compared to those in a group of individuals who were considered at risk of developing RA, stratified as either positive (n = 63) or negative (n = 47) for anti-citrullinated protein antibodies (ACPAs) (designated the at-risk group). Machine learning was used to identify a protein signature that could accurately classify those individuals at highest risk of future RA development.

RESULTS

A preclinical proteomic signature that differentiated RA progressors from at-risk individuals, irrespective of ACPA status, was identified (area under the curve 0.913, accuracy 91.2%). Importantly, the predictive preclinical proteomic signature was present not only in serum samples obtained close to the onset of RA, but also in serum samples obtained a median of 30.9 months prior to onset. Network analysis implicated the activation of Toll-like receptor 2 and production of tumor necrosis factor and interleukin-1 as key events that precede RA progression.

CONCLUSION

Alterations in the serum proteome in the preclinical phase of RA can emerge years prior to the onset of disease. Our findings suggest that the serum proteome provides a rich source of proteins serving both to classify at-risk individuals and to identify molecular pathways involved in the development of clinically detectable RA.

Epitope mapping and characterization of 4-hydroxy-2-nonenal modified-human serum albumin using two different polyclonal antibodies

Lipids are susceptible to damage by reactive oxygen species, and from lipid oxidation reactions many short chain lipid peroxidation products can be formed. 4-Hydroxy-2-nonenal (HNE) is one of the most abundant and cytotoxic lipid oxidation products and is known to form covalent adducts with nucleophilic amino acids of proteins. HNE-modified proteins have value as biomarkers and can be detected by antibody-based techniques, but most commercially available antibodies were raised against HNE-keyhole limpet hemocyanin. We used HNE-treated human serum albumin (HSA) to raise sheep antiserum and report for the first time the use of covalently modified peptide arrays to assess epitope binding of antibodies (Abs). Peptide arrays covering the sequence of HSA and treated post peptide synthesis with HNE were used to compare the different binding patterns of a commercial polyclonal antibody (pAb) raised against HNE-treated KLH and an in-house anti-HNE enriched pAb. The results were correlated with analysis of HNE-modified HSA by high-resolution tandem mass spectrometry. Both anti-HNE pAbs were found to bind strongly to eight common peptides on the HNE-treated HSA membranes, suggesting that HNE adducts per se induced an immune response in both cases even though different immunogens were used. Both antibodies bound with the highest affinity to the peptide ³⁶⁵DPHECYAKVFDEFKPLV³⁸¹, which contains K378 and was also shown to be modified by the mass spectrometry analysis. Overall, the commercial anti-HNE pAb showed better specificity, recognizing nine out of the eleven adducts found by MS/MS, while the in-house enriched pAb only recognizes six. Nevertheless, the in-house pAb recognized specific peptides that were not recognized by the commercial pAb, which suggests the presence of clones uniquely specific to HNE adducts on HSA.

Use of Long-term Cumulative Blood Pressure in Cardiovascular Risk Prediction Models

Importance

Long-term cumulative systolic blood pressure (SBP) is significantly associated with increased rates of atherosclerotic cardiovascular disease (ASCVD) development independent of single SBP levels. However, published ASCVD risk prediction algorithms only include currently measured SBP.

Objective

To determine whether including long-term (5- and 10-year) cumulative SBP in risk equations improves the predictive ability compared with single SBP measurements.

Design, Setting, and Participants

Adults aged 45 to 65 years at the time of risk estimation with at least 20 years of follow-up (5 and 10 years prior to risk estimation and 10 years of event follow-up). The Lifetime Risk Pooling Project included data from the following cohorts: Coronary Artery Risk Development in Young Adults Study, Atherosclerosis Risk in Communities Study, and Framingham Heart Study (both the original and offspring).

Exposures

Ten-year ASCVD risk, calculated using the approach of the 2013 American College of Cardiology/American Heart Association 10-year ASCVD risk equations, first with current SBP and then substituting 5- and 10-year cumulative SBP levels.

Main Outcomes and Measures

Incident ASCVD events that occurred over 10 years of follow-up, compared with the predicted risks, using the C statistic, net reclassification index at event rate, and the integrated discrimination index.

Results

This study included 11 767 participants with a mean (SD) age of 59.1 (4.7) years at risk estimation. A total of 6873 participants (58%) were women, and 1499 (13%) were African American. In the 10 years of follow-up from risk estimation, 1887 participants (16%) had an ASCVD event. There were no significant improvements in the C statistic when including 5- or 10-year cumulative SBP. However, the addition of cumulative SBP resulted in significant improvements in the net reclassification index at event rate (10-year net reclassification index for men, 0.04 [95% CI, 0.02-0.06]; 10-year net reclassification index for women, 0.03 [95% CI, 0.01-0.06]) and the relative integrated discrimination index (10-year relative integrated discrimination index for men, 0.12; 10-year relative integrated discrimination index for women, 0.10).

Conclusions and Relevance

Using long-term measures of cumulative blood pressure, instead of single measurements, can modestly improve the ability of cardiovascular disease risk prediction models to correctly classify individuals in terms of their risk for cardiovascular disease.

Using Machine Learning to Integrate Socio-Behavioral Factors in Predicting Cardiovascular-Related Mortality Risk

Cardiovascular disease is prevalent and associated with significant mortality rate. Robust lifetime risk stratification for cardiovascular disease is important for effective prevention, early diagnoses, targeted intervention, and improved prognosis. Health disparities, manifested as socio-behavioral factors, are believed to have multiple effects throughout life with great complexity. Multiple studies investigated lifetime cardiovascular-related mortality risk prediction focusing on subjects' pathophysiology and intervention profiles. In this study, we applied machine learning algorithms and focused on integrating socio-behavioral factors to pathophysiology and intervention profiles to predict cardiovascular-related mortality risk. Our results showed that multiple machine learning algorithms can predict risk with reasonable accuracy, using mixed types of features. Particularly, socio-behavioral factors contributed significantly to the improved accuracy of mortality risk prediction. Feature analysis identified the odds ratio of socio-behavioral factors for cardiovascular-related mortality and offered potential insights on how they impact subjects' long-term outcomes. Our results call for further investigation of this important topic.

Novel Use of Telemedicine for Corneal Tissue Evaluation in Eye Banking: Establishing a Standardized Approach for the Remote Evaluation of Donor Corneas for Transplantation

PURPOSE

To determine the feasibility of using telemedicine consultations in the evaluation of recovered donor corneas for transplant suitability.

METHODS

This study aims to establish and test the minimum imaging requirements for telemedical consultations of corneal tissue by remote eye bank medical directors. Digital images from the slit lamp, optical coherence tomography, and/or specular microscope were assembled into telemedical consults and emailed to 4 eye bank medical directors (M.A.T., J.W., C.S.S., N.K.R.). Feedback on the minimum image requirements for each corneal finding was collected. After establishing a standardized imaging and presentation protocol, test cases were presented to the medical directors to examine the validity of these remote consults. To establish a benchmark for the study's parameters, one medical director (J.W.) examined each case in person after his initial remote review. Examiners were masked to each other's responses.

RESULTS

Minimum image requirements for determination of corneal findings were defined and were specific to each anatomic layer of the cornea (epithelial, stromal, or endothelial). Using a defined set of digital images for a set of common corneal findings, the rate of agreement between remote evaluators, eye bank staff, and the in-person evaluator was 100% (11 of 11 examples). For ambiguous test cases, remote evaluators agreed on 80% of the cases (4 of 5).

CONCLUSIONS

Results from this pilot study suggest that telemedical review of corneal tissue using high-quality digital images may be adequate for accurate identification of specific corneal findings commonly encountered by eye banks.

High-Density Lipoprotein Subfractions and Cholesterol Efflux Capacity Are Not Affected by Supervised Exercise but Are Associated with Baseline Interleukin-6 in Patients with Peripheral Artery Disease

OBJECTIVE

To quantify the association between high-density lipoprotein (HDL) subfractions, efflux capacity, and inflammatory markers at baseline and the effect of supervised exercise on these HDL parameters in patients with peripheral artery disease (PAD).

METHODS

The study to improve leg circulation (SILC) was a randomized trial of supervised treadmill exercise, leg resistance training, or control in individuals with PAD. In a post hoc cross-sectional analysis, we quantified the associations between baseline HDL subfraction concentrations (HDL2 and HDL3), HDL-C efflux capacity, and inflammatory markers [C-reactive protein (CRP) and interleukin-6 (IL-6)]. We then examined the effect of supervised exercise on changes in these lipoprotein parameters and inflammatory markers in 88 patients from SILC.

RESULTS

Baseline HDL-C efflux capacity was associated with baseline concentrations of HDL2 (β = 0.008, p = 0.0106), HDL3 (β = 0.013, p < 0.0001), and IL-6 (β = -0.019, p = 0.03). Baseline HDL3 concentration was inversely associated with IL-6 concentration (β = -0.99, p = 0.008). Compared to control, changes in HDL2, HDL3, normalized HDL-C efflux capacity, CRP, or IL-6 were not significantly different at 6 months following the structured exercise intervention.

CONCLUSION

HDL efflux and HDL3 were inversely associated with IL-6 in PAD patients. Structured exercise was not associated with changes in HDL subfractions, HDL-C efflux capacity, CRP, and IL-6 in PAD patients. Our preliminary findings support the theory that inflammation may adversely affect HDL structure and function; however, further studies are needed to evaluate these findings.

Plaque Composition in the Proximal Superficial Femoral Artery and Peripheral Artery Disease Events

OBJECTIVES

The aim of this study was to describe associations of the presence of lipid-rich necrotic core (LRNC) in the proximal superficial femoral artery (SFA) with lower extremity peripheral artery disease (PAD) event rates and systemic cardiovascular event rates.

BACKGROUND

LRNC in the coronary and carotid arteries is associated with adverse outcomes but has not been studied previously in lower extremity arteries.

METHODS

Participants with ankle-brachial index (ABI) values <1.00 were identified from Chicago medical centers and followed annually. Magnetic resonance imaging was used to characterize SFA atherosclerotic plaque at baseline. Medical records for hospitalizations and procedures after baseline were adjudicated for lower extremity revascularization, amputation, and critical limb ischemia and also for new coronary events, ischemic stroke, and mortality.

RESULTS

Of 254 participants with PAD, 62 (24%) had LRNC and 149 (59%) had calcium in the SFA at baseline. Cox regression analyses were adjusted for age, sex, race, comorbidities, baseline ABI, and other confounders. SFA LRNC was associated with an increased incidence of the combined outcome of lower extremity amputation, critical limb ischemia, ABI decline >0.15, and revascularization at 47-month follow-up (hazard ratio: 2.18; 95% confidence interval: 1.27 to 3.75; p = 0.005). The association of SFA LRNC with PAD events was maintained even when this combined outcome excluded lower extremity revascularization (hazard ratio: 2.58; 95% confidence interval: 1.25 to 5.33; p = 0.01). LRNC in the SFA was not associated with all-cause mortality, acute coronary events, or stroke.

CONCLUSIONS

Among patients with PAD, LRNC in the SFA was associated with higher rates of clinical PAD events, and this association was independent of ABI. Further study is needed to determine whether interventions that reduce SFA LRNC prevent PAD events.

Population Pharmacokinetics and Pharmacodynamics of the Calcimimetic Etelcalcetide in Chronic Kidney Disease and Secondary Hyperparathyroidism Receiving Hemodialysis

Etelcalcetide is a novel calcimimetic in development for the treatment of secondary hyperparathyroidism (SHPT). A population pharmacokinetic/pharmacodynamic (PK/PD) model was developed relating etelcalcetide exposures to markers of efficacy (parathyroid hormone [PTH]) and safety (calcium) using data from three clinical studies. The semimechanistic model was developed that included allosteric activation pharmacology and understanding of calcium homeostasis. The temporal profiles for all biomarkers were well described by the model. The cooperativity constant was 4.94, confirming allosteric activation mechanism. Subjects with more severe disease (higher PTH baseline) were predicted to experience less pronounced reduction in PTH (percentage change from baseline), but more reduction in calcium (Ca; percentage change from baseline). There was no evidence that dose adjustment by any covariate was needed. Model‐based simulations provided quantitative support to several elements of dosing, such as starting dose, monitoring, and titration timing for registration trials.

Viral Load and Neuropsychological Functioning in HIV Seropositive Individuals:A Preliminary Descriptive Study

We have theorized a direct relationship between viral burden and deleterious effects on the central nervous systems. It was hypothesized that HIV+ individuals would manifest poorer neuropsychological functioning after increased viral load. To address this, we compared viral burden to neuropsychological performance in subjects who participated in ACTG 116-118. Plasma samples and neuropsychological assessments completed at the same time were available for 64 observations on 21 subjects. Subjects who had a viral peak of over 1000 TCID per ml were classified as high viral load, those who did not as low viral load. Mean performances of the high viral load subjects were poorer, even though baseline performances were slightly poorer in the low viral load group. Mean post-viral peak performances were poorer than pre-viral peak performances. Declines in neuropsychological performance were found significantly more often in the high viral load group. These findings support the viral load hypothesis.

Good food and bad: Nutritional and pleasurable eating in ancient Greece

ETHNOPHARMACOLOGICAL RELEVANCE

This paper speaks to the theme of the boundaries of food and medicine as constructed in the Greek and Roman worlds. It examines how physicians developed innovative ways of thinking about the body that did not attribute health and sickness to the intervention of gods. Ancient physicians and natural historians conceived of new potencies for substances and described their impact on the body׳s physiology between the late fifth century BC and the early third century AD. The legacy of these ideas and practices had great traction in the Mediterranean world and survived into Early Modern Times, and until the rise of new forms of science.

MATERIALS AND METHODS

This article analyses texts transmitted from the ancient world and considers how substances were attributed nutritional and medical potency. The texts relevant to this analysis include medical and philosophical treatises as well as cookery books. The article highlights discussions about the nature of food and drugs and the herbs thought to cross the boundaries between them. It interrogates different contexts within which foods were thought good or bad for the body, and the social and moral connotations attached to those perceptions.

CONCLUSION

Much of the analysis is devoted to understanding the flavours that were a key marker in the nutritional potencies attributed to foodstuffs. However there are clear and influential moral boundaries set by Plato in the discourse around food and pleasure. While every physician should be a chef, and many wrote cookery books that have been lost, a chef׳s talent was located in increasing pleasure, and therefore a less valuable skill. However the different literary genres show overlapping terminology and concerns, particularly with the quality of ingredients. Poor taste was not only a culinary concern. With regard to the setting of boundaries between foods and medicines, the transition between one category and another is frequently determined by the preparation and strengthening of a food׳s potency.

Abstract 2488: Analysis of the salivary proteome of the prolactin-inducible-protein knockout mouse

The human Prolactin-Inducible-Protein (PIP)/Gross Cystic Disease Fluid Protein 15 (GCDFP-15) gene is abnormally expressed in human invasive breast cancer and gross cystic disease of the breast. In healthy individuals PIP is highly expressed in salivary, sweat and lacrimal glands, and the secreted protein abundantly found in saliva as well as other bodily fluids which bathe various ports of entry. PIP has been shown to bind numerous bacterial strains as well as a number of immunoregulatory molecules including the CD4-T cell receptor and IgG and is therefore implicated to play an immune role in host defense. In the present study we interrogated the salivary proteome of the PIP knockout (Pip KO) mouse by mass spectrometry to determine protein changes that occur in saliva in the absence of PIP. Proteomic analysis identified 165 proteins in the mouse saliva which had a minimum of 2 unique peptides at the 99% confidence level. Nineteen proteins, including 2 proposed markers of disease, S100A9 and adenosine deaminase, were significantly differentially expressed in the saliva of the Pip KO mouse, compared to the saliva of the wild type counterparts. Functional and biological determinations revealed that the differentially expressed proteins were associated with processes that include inflammatory responses, immunity and cell death. This study provides evidence that a number of proteins associated with host defense are affected by the loss of PIP, and lends support for an immunomodulatory role for PIP.

Citation Format: Anne Blanchard, Peyman Ezzati, Xiuli Ma, John Wilkins, Yvonne Myal. Analysis of the salivary proteome of the prolactin-inducible-protein knockout mouse. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2488. doi:10.1158/1538-7445.AM2014-2488

Associations between nonalcoholic fatty liver disease and subclinical atherosclerosis in middle-aged adults: the Coronary Artery Risk Development in Young Adults Study

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is an obesity-related condition associated with cardiovascular mortality. Yet, whether or not NAFLD is independently related to atherosclerosis is unclear. In a population-based cross-sectional sample of middle-aged adults free from liver or heart disease, we tested the hypothesis that NAFLD is associated with subclinical atherosclerosis (coronary artery (CAC) and abdominal aortic calcification (AAC)) independent of obesity.

METHODS

Participants from the Coronary Artery Risk Development in Young Adults study with CT quantification of liver fat, CAC and AAC were included (n = 2424). NAFLD was defined as liver attenuation ≤40 Hounsfield Units after exclusion of other causes of liver fat. CAC and AAC presence was defined as Agatston score >0.

RESULTS

Mean participant age was 50.1 ± 3.6 years, (42.7% men, 50.0% black) and BMI was 30.6 ± 7.2 kg/m(2). The prevalence of NAFLD, CAC, and AAC was 9.6%, 27.1%, and 51.4%. NAFLD participants had increased prevalence of CAC (37.9% vs. 26.0%, p < 0.001) and AAC (65.1% vs. 49.9%, p < 0.001). NAFLD remained associated with CAC (OR, 1.33; 95% CI, 1.001-1.82) and AAC (OR, 1.74; 95% CI, 1.29-2.35) after adjustment for demographics and health behaviors. However, these associations were attenuated after additional adjustment for visceral adipose tissue (CAC OR, 1.05; 95% CI, 0.74-1.48, AAC OR = 1.20; 95% CI, 0.86-1.67). There was no interaction by race or sex.

CONCLUSION

In contrast to prior research, these findings suggest that obesity attenuates the relationship between NAFLD and subclinical atherosclerosis. Further studies evaluating the role of NAFLD duration on atherosclerotic progression and cardiovascular events are needed.

Galen and Wellbeing: Whole Person Care

n/a - commentary

Identification of the Transmembrane Glucose Regulated Protein 78 as a Biomarker for the Brain Cancer Glioblastoma Multiforme by Gene Expression and Proteomic Studies

The prognosis of patients with Glioblastoma Multiforme (GBM), the most malignant adult glial brain tumor, remains poor in spite of advances in treatment procedures, including surgical resection, irradiation and chemotherapy. Genetic heterogeneity of GBM warrants extensive studies to gain a thorough understanding of the biology of this tumor. While there have been several studies of global transcript profiling of glioma with the identification of gene signatures for diagnosis and disease management, translation into clinics is yet to happen. In the present study, we report a novel proteomic approach by using two-dimensional difference gel electrophoresis (2D-DIGE) followed by spot picking and analysis of proteins/peptides by Mass Spectrometry. We report Glucose Regulated Protein 78 (GRP78) as a differentially expressed protein in the GBM cell line compared to human normal Astrocyte cells.

In addition to proteomic studies, we performed microarray analysis which further confirmed up regulation of GRP78 in GBM cells compared to human normal Astrocyte cells.

GRP78 has long been recognized as a molecular chaperone in the endoplasmic reticulum (ER) and can be induced by the ER stress response. Besides its location in the ER, GRP78 has been found in cell plasma membrane, cytoplasm, mitochondria, nucleus and other cellular secretions. GRP78 is implicated in tumor cell proliferation, apoptosis resistance, immune escape, metastasis and angiogenesis, and its elevated expression usually correlates with a variety of tumor micro environmental stresses, including hypoxia, glucose deprivation, lactic acidosis and inflammatory response. GRP78 protein acts as a centrally located sensor of stress, which senses and facilitates the adaptation to the tumor microenvironment.

Our findings showed differential expression of this gene in brain cancer GBM and thus confirm similarities in findings in existing transcriptional and translational studies. Thus, these findings could be of further importance for diagnostic, therapeutic and prognostic approaches for dealing with this highly malignant cancer.

Granzyme B inhibits translation of viral proteins and viral replication through proteolytic cleavage of the eukaryotic initiation factor 4 gamma 3 (154.35)

Cytotoxic T lymphocytes (CTL) are the major killer of virus-infected cells. Granzyme B (GrB) from CTL induces apoptosis in target cells by cleavage and activation of substrates such as caspase-3. However, while undergoing apoptosis, cells can still produce infectious viruses unless a mechanism exists to specifically inhibit viral production. Using proteomic approaches, we found a novel GrB target that plays a major role in protein synthesis: eukaryotic initiation factor 4 Gamma 3 (eIF4G3). We hypothesized a novel role for GrB to arrest translation of viral proteins by targeting eIF4G3, which contains the GrB recognition sequence IESD1408S. We showed that GrB specifically cleaves eIF4G3 since the mutant eIF4G-Δ, with Ala substituted for D1408, was resistant to GrB degradation. Translational inhibition by GrB was reversed by the inclusion of eIF4G-Δ, showing that eIF4G3 is the critical GrB substrate involved in translation. In Jurkat cells, GrB or CTL treatment resulted in reduced rate of translation. We infected Jurkat cells with vaccinia virus (VV) and showed that viral protein synthesis and viral replication was inhibited in response to GrB or CTL. Transfection of eIF4G-Δ reversed the halt in protein synthesis induced by GrB. This demonstrated for the first time that GrB could prevent the production of VV by targeting the translational machinery of the host. These results represent a major new insight into what constitutes an effective CTL response to a virus-infected cell.

Clinical experience with an antimicrobial hydrogel dressing on recalcitrant wounds

OBJECTIVE

To assess the performance of a newly-introduced, iodine-based antimicrobial wound dressing (Iodozyme) within normal clinical practice.

METHOD

51 case records were collected from 30 wound care locations in England. Reporting clinicians used Iodozyme on one or more difficult wounds of their own choice (of various aetiologies) from their current case loads. Basic patient-specific data were collected, relating to both their own and their patients' experience with the product over a 6-week period of treatment (or less, if healing was achieved earlier). In every case, the wound continued to be treated in accordance with local 'best practice', in accordance with the manufacturer's instructions and by the same clinician. Each wound was assessed in terms of size, condition (margins and wound bed), exudate (type and amount), comfort/pain, overall satisfaction (by patient and clinician) and healing status (in terms of healed, improved, static or deteriorated). In addition, clinicians were asked to use their own local criteria and parameters where possible, with general guidance as and when it was needed.

RESULTS

The mean duration of all wounds was 25.8 months (median 13 and range 1-312). Nine patients had a wound of less than six months' duration, and 17 had one of two years' or more duration. Within the 6-week study period, 6 wounds healed fully, 37 were judged to have improved, 7 remained static and 1 deteriorated. Overall, the majority of clinicians and patients were 'satisfied' or 'very satisfied' with product performance and 77% of clinicians concluded that the dressing was 'better' or 'much better' than other dressings they had previously used on similar wounds.

CONCLUSION

While we cannot generalise from this study, the encouraging clinical results and positive patient and clinician feedback lead us to believe that Iodozyme is a dressing worthy of consideration when treating chronic wounds. These encouraging preliminary findings are now to be followed up with a randomised control trial.

Phylogeny and growth strategy as predictors of differences in cobalt concentrations between plant species

Analyses reported here quantify the contribution of plant phylogeny and plant growth strategy to soil-to-plant transfer of Co. Estimated relative mean (ERM) Co concentrations in shoots of 241 species of flowering plant were derived using a residual maximum likelihood (REML) analysis. There were significant differences in, and a loge-normal frequency distribution of, ERM Co concentrations between species. A significant percentage of interspecies variance could be assigned to taxonomic categories above the species, (Family and above 21.5%; Order and above 12.22%). Time-series analysis of ERM Co concentrations ordered in the species-sequence of the Angiosperm Phylogeny Group (APG II (2003)) revealed significant autocorrelation with an increase from Commelinid Monocot to Asterid Eudicot and a pronounced peak in the Core Eudicots. ERM Co concentrations categorized by plant growth strategy sensu Grime (2001) showed an increase toward stress-tolerant strategies. Plant species are not, therefore, independent units of Co concentration--factors derived from higher levels of biological organization exert significant effects. These effects can provide the basis of new techniques for selecting plant species for biotechnologies and for predicting the exposure of organisms to Co. They show that plant phylogeny and growth strategy might help refine predictions of soil-to-plant transfer of a variety of pollutants, and suggest research that might link molecular and higher level processes in contaminated soil-plant systems.

275. The endocrine disruptor, bisphenol A, alters gene expression in the hypothalamus of the ram lamb but does not alter LH secretion

Bisphenol A (BPA) is an endocrine disruptor, which has both oestrogenic and anti-oestrogenic actions. It has profound effects on development, especially of sex organs but also on the brain. The actions on the brain are poorly understood and little is known about males. Most work has been conducted in fish & rodents, but the lifespan of domestic ruminants means that BPA may accumulate in tissues over many years. This study tested the hypothesis that treatment of ram lambs with BPA would alter LH secretion as well as gene activity in various hypothalamic regions. Ram lambs were treated from 1 month old with thrice weekly injections (im) of BPA (3.5 mg/kg) or vehicle (n = 10/group) for 80days. Weekly bodyweights and jugular blood samples were collected and on day 79, blood samples were taken every 15 min for 8 h for LH RIA. The sheep were killed, body & testicular weights collected and the hypothalamus dissected into anterior, dorsal and ventral blocks, then frozen in liquid nitrogen. Bodyweight (Cont. 26.0 ± 0.5 kg v. BPA 25.2 ± 0.7 kg) and paired testicular weight (Cont. 31.6 ± 1.2 g v. BPA 29.3 ± 1.4 g) did not significantly differ (P > 0.05). LH secretion also did not differ, in either mean LH concentrations (Cont 0.31 ± 0.14 v. BPA 0.29 ± 0.12ng/mL) or pulses/8 h (Cont 1.8 ± 0.4 v. BPA 2.0 ± 0.4). Total RNA was extracted from the basal hypothalamus (ventral block) and RNA from 2 treated and 2 control animals was hybridised on 44K Agilent bovine microarrays. Preliminary analysis suggests 118 probes were differentially expressed. Gene ontology analysis of these differentially expressed probes revealed involvement in a broad range of biological processes and cellular components. This study suggests that gene array analysis is a suitable tool with which to study BPA actions in the sheep hypothalamus. Future work will expand this pilot microarray study to include all animals and all hypothalamic regions.

A-272651, a nonpeptidic blocker of large-conductance Ca2+-activated K+ channels, modulates bladder smooth muscle contractility and neuronal action potentials

BACKGROUND AND PURPOSE

The large-conductance Ca(2+)-activated K(+) channel (BK(Ca), K(Ca)1.1) links membrane excitability with intracellular Ca(2+) signaling and plays important roles in smooth muscle contraction, neuronal firing, and neuroendocrine secretion. This study reports the characterization of a novel BK(Ca) channel blocker, 2,4-dimethoxy-N-naphthalen-2-yl-benzamide (A-272651).

EXPERIMENTAL APPROACH

(86)Rb(+) efflux in HEK-293 cells expressing BK(Ca) was measured. Effects of A-272651 on BK(Ca) alpha- and BK(Ca) alphabeta1-mediated currents were evaluated by patch-clamp. Effects on contractility were assessed using low-frequency electrical field stimulated pig detrusor and spontaneously contracting guinea pig detrusor. Effects of A-272651 on neuronal activity were determined in rat small diameter dorsal root ganglia (DRG).

KEY RESULTS

A-272651 (10 microM) inhibited (86)Rb(+) efflux evoked by NS-1608 in HEK-293 cells expressing BK(Ca) currents. A-272651 concentration-dependently inhibited BK(Ca) currents with IC(50) values of 4.59 microM (Hill coefficient 1.04, measured at +40 mV), and 2.82 microM (Hill coefficient 0.89), respectively, for BK(Ca) alpha and BK(Ca) alphabeta1-mediated currents. Like iberiotoxin, A-272651 enhanced field stimulated twitch responses in pig detrusor and spontaneous contractions in guinea pig detrusor with EC(50) values of 4.05+/-0.05 and 37.95+/-0.12 microM, respectively. In capsaicin-sensitive DRG neurons, application of A-272651 increased action potential firing and prolonged action potential duration.

CONCLUSIONS AND IMPLICATIONS

These data demonstrate that A-272651 modulates smooth muscle contractility and neuronal firing properties. Unlike previously reported peptide BK(Ca) blockers, A-272651 represents one of the first small molecule BK(Ca) channel blockers that could serve as a useful tool for further characterization of BK(Ca) channels in physiological and pathological states.

The use of a systemic prime/mucosal boost strategy with an equine influenza ISCOM vaccine to induce protective immunity in horses

In horses, natural infection confers long lasting protective immunity characterised by mucosal IgA and humoral IgGa and IgGb responses. In order to investigate the potential of locally administered vaccine to induce a protective IgA response, responses generated by vaccination with an immunostimulating complex (ISCOM)-based vaccine for equine influenza (EQUIP F) containing A/eq/Newmarket/77 (H7N7), A/eq/Borlänge/91 (H3N8) and A/eq/Kentucky/98 (H3N8) using a systemic prime/mucosal boost strategy were studied. Seven ponies in the vaccine group received EQUIP F vaccine intranasally 6 weeks after an initial intramuscular immunisation. Following intranasal boosting a transient increase in virus-specific IgA was detected in nasal wash secretions. Aerosol challenge with the A/eq/Newmarket/1/93 reference strain 4 weeks after the intranasal booster resulted in clinical signs of infection and viral shedding in seven of seven influenza-naive control animals whereas the seven vaccinated ponies had statistically significantly reduced clinical signs and duration of virus excretion. Furthermore, following this challenge, significantly enhanced levels of virus-specific IgA were detected in the nasal washes from vaccinated ponies compared with the unvaccinated control animals. These data indicate that the intranasal administration of EQUIP F vaccine primes the mucosal system for an enhanced IgA response following exposure to live influenza virus.

Immune responses and protective efficacy in ponies immunised with an equine influenza ISCOM vaccine containing an 'American lineage' H3N8 virus

Protective responses generated by vaccination with an immuno-stimulating complex (ISCOM)-based vaccine for equine influenza (EQUIP F), containing a new 'American lineage' H3N8 virus, were studied. Seven ponies in the vaccine group received two intramuscular injections of EQUIP F given 6 weeks apart. Aerosol challenge with an A/eq/Newmarket/1/93 reference strain 4 weeks after booster vaccination resulted in clinical signs of infection and viral shedding in 7 influenza-naive control animals whereas the vaccinated ponies were significantly protected from both clinical signs and virus excretion. Influenza virus-specific IgG responses in serum following immunisation with the ISCOM vaccine were predominantly of the IgGa and IgGb sub-isotypes, a pattern similar to that generated by equine influenza virus infection. However, in contrast to the response following infection, virus-specific antibody responses in nasal washes following immunisation were characterised by the presence of IgG but not IgA.These results demonstrated that an ISCOM-based vaccine containing A/eq/Kentucky/98 provides strong protective immunity against challenge with an 'American lineage' H3N8 reference virus.

The social and intellectual context of Regimen II

This paper addresses two questions, what is the social/historical context of Regimen II and how has the author organised his data? It establishes a framework for interrogating the Hippocratic text that is based on Galen's use of case studies across a wide social range, on his commentary on Hippocrates, Diodes, Mnesitheus and Praxagoras, and on his approach to terminology, definition and classification. The conclusion is that the Hippocratic text established its data successfully (to judge by Galen's criteria) before Aristotle and Theophrastus, but that the text was too laconic to be widely used. Hence Galen's new treatise rather than commentary on his Hippocratic predecessor.

Urine protein profiling with surface-enhanced laser-desorption/ionization time-of-flight mass spectrometry

BACKGROUND

In the last few years there has been an increasing interest in exploring the human proteome. In particular, efforts have focused on developing strategies to generate reproducible protein maps of normal cells, tissues, and biologic fluids, from which studies can then compare protein expression between different groups (e.g., healthy individuals vs. those with a specific pathologic state).

METHODS

Various extrinsic factors (instrument settings, matrix composition, urine storage post void, freeze-thaw cycles) and intrinsic factors (blood in urine, urine dilution, first-void vs. midstream urine) were analyzed with respect to their impact on urine protein profiling using surface-enhanced laser-desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS).

RESULTS

Extrinsic factors that critically influenced reproducibility and peak detection of urine protein profiling were matrix composition and instrument settings, while freeze-thaw cycles had minimal impact. Midstream urines samples did not undergo changes in their protein profile when stored for three days at 4 degrees C. Intrinsic factors that influenced normal urine protein profiling were blood in the urine and urine dilution. Female first-void urine had a significantly different ratio of proteins present compared to a midstream urine sample. Limitations of the SELDI-TOF-MS technique included ion suppression and quantification of individual proteins when protein composition was complex.

CONCLUSION

SELDI-TOF-MS offers a unique platform for high throughput urine protein profiling; however, standardization of analysis conditions is critical, and both extrinsic and intrinsic factors must be taken into account for accurate data interpretation.

Proteomic-based detection of urine proteins associated with acute renal allograft rejection

At present, the diagnosis of renal allograft rejection requires a renal biopsy. Clinical management of renal transplant patients would be improved by the development of non-invasive markers of rejection that can be measured frequently. This study sought to determine whether such candidate proteins can be detected in urine using mass spectrometry. Four patient groups were rigidly defined on the basis of allograft function, clinical course, and allograft biopsy result: acute clinical rejection group (n = 18), stable transplant group (n = 22), acute tubular necrosis group (n = 5), and recurrent (or de novo) glomerulopathy group (n = 5). Urines collected the day of the allograft biopsy were analyzed by mass spectrometry. As a normal control group, 28 urines from healthy individuals were analyzed the identical manner, as well as 5 urines from non-transplanted patients with lower urinary tract infection. Furthermore, sequential urine analysis was performed in patients in the acute clinical rejection and the stable transplant group. Three prominent peak clusters were found in 17 of 18 patients (94%) with acute rejection episodes, but only in 4 of 22 patients (18%) without clinical and histologic evidence for rejection and in 0 of 28 normal controls (P < 0.001). In addition, the presence or absence of these peak clusters correlated with the clinicopathologic course in most patients. Acute tubular necrosis, glomerulopathies, lower urinary tract infection, and cytomegalovirus viremia were not confounding variables. In conclusion, proteomic technology together with stringent definition of patient groups can detect urine proteins associated with acute renal allograft rejection. Identification of these proteins may prove useful as non-invasive diagnostic markers for rejection and the development of novel therapeutic agents.