CCL14 Predicts Oliguria and Dialysis Requirement in Patients with Moderate to Severe Acute Kidney Injury.

INTRODUCTION: AKI is a frequent complication of critical illness and portends poor outcome. CCL14 is a validated predictor of persistent severe AKI in critically ill patients. We examined the association of CCL14 with urine output within 48 h. METHODS: In pooled data from 2 studies of critically ill patients with KDIGO stage 2-3 AKI, CCL14 was measured by NEPHROCLEAR™ CCL14 Test on the Astute 140® Meter (low, intermediate, and high categories [1.3 and 13 ng/mL]). Average hourly urine output over 48 h, stage 3 AKI per urine output criterion on day 2, and composite of dialysis or death within 7 days were examined using multivariable mixed and logistic regression models. RESULTS: Of the 497 subjects with median age of 65 (56-74) years, 49% (242/497) were on diuretics. CCL14 concentration was low in 219 (44%), intermediate in 217 (44%), and high in 61 (12%) patients. In mixed regression analysis, hourly urine output over time was different within each CCL14 risk category based on diuretic use due to significant three-way interaction (p < 0.001). In logistic regression analysis, CCL14 risk category was independently associated with low urine output on day 2 per KDIGO stage 3 (adjusted for diuretic use and baseline clinical variables), and composite of dialysis or death within 7 days (adjusted for urine output within 48 h of CCL14 measurement). CONCLUSIONS: CCL14 measured in patients with moderate to severe AKI is associated with urine output trajectory within 48 h, oliguria on day 2, and dialysis within 7 days.

Age Specificity of Effects of Health Problems on Drinking Reduction: A Lifespan Developmental Analysis.

Older adult drinking poses a growing public health concern, especially given the ongoing aging of the United States population. As part of a larger lifespan developmental project contrasting predictors of drinking reductions across different periods of adulthood, we tested age differences in effects of health problems on drinking declines across young adulthood, midlife, and older adulthood. We predicted these effects to be developmentally specific to midlife and older adulthood. We also tested moderation by alcohol use disorder (AUD) symptomatology and by indices of sociodemographic disadvantage (sex and race/ethnicity). Analyses used data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), leveraging NESARC's vast age range (18-90 + ; N = 43,093) and two waves of longitudinal data. Multiple-group cross-lag models tested differences across age groups in cross-lag paths between health problems and alcohol consumption. As hypothesized, health problem effects on drinking reductions were developmentally specific to midlife and older adulthood. However, models testing moderation by AUD symptomatology showed that these adaptive effects of health problems on drinking reductions did not extend to those with one or more AUD symptoms. Little evidence was found for moderation by sex or race/ethnicity. Findings support the notion of health concerns as a pathway to drinking reduction that increases in importance across the adult lifespan. However, given the moderation by AUD symptoms, findings also highlight a need to understand barriers to health-related pathways to drinking reduction among relatively severe midlife and older adult drinkers. These findings hold implications for lifespan developmental tailoring of clinical, public health, and policy interventions.

A life span developmental investigation of marriage and problem-drinking reduction.

While prior literature has largely focused on marriage effects during young adulthood, it is less clear whether these effects are as strong in middle adulthood. Thus, we investigated age differences in marriage effects on problem-drinking reduction. We employed parallel analyses with two independent samples (analytic-sample Ns of 577 and 441, respectively). Both are high-risk samples by design, with about 50% of participants having a parent with lifetime alcohol use disorder. Both samples have been assessed longitudinally from early young adulthood to the mid-to-late 30s. Separate parallel analyses with these two samples allowed evaluation of the reproducibility of results. Growth models of problem drinking tested marriage as a time-varying predictor and thereby assessed age differences in marriage effects. For both samples, results consistently showed marriage effects to be strongest in early young adulthood and to decrease somewhat monotonically thereafter with age, reaching very small (and nonsignificant) magnitudes by the 30s. Results may reflect that role transitions like marriage have more impact on problem drinking in earlier versus later adulthood, thereby highlighting the importance of life span developmental research for understanding problem-drinking desistance. Our findings can inform intervention strategies aimed at reducing problem drinking by jumpstarting or amplifying natural processes of adult role adaptation.

Limiting Acute Kidney Injury Progression In Sepsis: Study Protocol and Trial Simulation.

OBJECTIVES: To describe study design considerations and to simulate a trial of biomarker-guided sepsis management aimed to reduce acute kidney injury (acute kidney injury). Tissue inhibitor of metalloproteinases-2 and insulin-like growth factor-binding protein 7, urinary biomarkers of cell-cycle arrest, and indicators of kidney stress can detect acute kidney injury before clinical manifestations. We sought to determine the event rates for acute kidney injury as a function of serial measurements of urinary (tissue inhibitor of metalloproteinases-2)•(insulin-like growth factor-binding protein 7) in patients at risk of sepsis-associated acute kidney injury, so that an escalating series of kidney-sparing sepsis bundles based on international guidelines could be applied. DESIGN: We described the study protocol of "Limiting acute kidney injury Progression In Sepsis," a phase 4, multicenter, adaptive, randomized controlled trial. We performed simulations to estimate the rates for the trial's primary endpoint using patient-level data from two previous studies (Sapphire and Protocolized Care for Early Septic Shock). SETTING: Academic and community ICUs. PATIENTS: Critically ill patients with sepsis or septic shock, without evidence of stage 2/3 acute kidney injury at enrollment. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Our primary endpoint is progression of two or more stages of acute kidney injury, death, or dialysis within 72 hours after enrollment. In the Sapphire simulation, 45 of 203 patients (22%) with sepsis met the endpoint. In Protocolized Care for Early Septic Shock, 144 of 607 patients (24%) with septic shock met the endpoint. In both simulations, (tissue inhibitor of metalloproteinases-2)•(insulin-like growth factor-binding protein 7) patterns, suggested by Limiting acute kidney injury Progression In Sepsis protocol, stratified the risk for the endpoint from 6% (three negative tests) to 41% (for patients eligible for the highest level of kidney-sparing sepsis bundle) in Sapphire, and 14% (two negative tests) to 46% (for the highest level of kidney-sparing sepsis bundle) in Protocolized Care for Early Septic Shock. CONCLUSIONS: Findings of our Limiting acute kidney injury Progression In Sepsis trial simulation confirmed that (tissue inhibitor of metalloproteinases-2)•(insulin-like growth factor-binding protein 7) could identify patients with different rates of progression to moderate/severe acute kidney injury, death, or dialysis in 72 hours. The Limiting acute kidney injury Progression In Sepsis protocol algorithm is therefore feasible in terms of identifying suitably high-risk individuals for kidney-sparing sepsis bundle.

Use of Biomarkers to Identify Acute Kidney Injury to Help Detect Sepsis in Patients With Infection.

OBJECTIVES: Although early recognition of sepsis is vital to improving outcomes, the diagnosis may be missed or delayed in many patients. Acute kidney injury is one of the most common organ failures in patients with sepsis but may not be apparent on presentation. Novel biomarkers for acute kidney injury might improve organ failure recognition and facilitate earlier sepsis care. DESIGN: Retrospective, international, Sapphire study. SETTING: Academic Medical Center. PATIENTS: Adults admitted to the ICU without evidence of acute kidney injury at time of enrollment. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We stratified patients enrolled in the Sapphire study into three groups-those with a clinical diagnosis of sepsis (n = 216), those with infection without sepsis (n = 120), and those without infection (n = 387) at enrollment. We then examined 30-day mortality stratified by acute kidney injury within each group. Finally, we determined the operating characteristics for kidney stress markers (tissue inhibitor of metalloproteinases-2) × (insulin-like growth factor binding protein 7) for prediction of acute kidney injury as a sepsis-defining organ failure in patients with infection without a clinical diagnosis of sepsis at enrollment. Combining all groups, 30-day mortality was 23% for patients who developed stage 2-3 acute kidney injury within the first 3 days compared with 14% without stage 2-3 acute kidney injury. However, this difference was greatest in the infection without sepsis group (34% vs 11%; odds ratio, 4.09; 95% CI, 1.53-11.12; p = 0.005). Using a (tissue inhibitor of metalloproteinases-2) × (insulin-like growth factor binding protein 7) cutoff of 2.0 units, 14 patients (11.7%), in the infection/no sepsis group, tested positive of which 10 (71.4%) developed stage 2-3 acute kidney injury. The positive test result occurred a median of 19 hours (interquartile range, 0.8-34.0 hr) before acute kidney injury manifested by serum creatinine or urine output. Similar results were obtained using a cutoff of 1.0 for any stage of acute kidney injury. CONCLUSIONS: Use of the urinary (tissue inhibitor of metalloproteinases-2) × (insulin-like growth factor binding protein 7) test could identify acute kidney injury in patients with infection, possibly helping to detect sepsis, nearly a day before acute kidney injury is apparent by clinical criteria.

External validation of urinary C-C motif chemokine ligand 14 (CCL14) for prediction of persistent acute kidney injury.

BACKGROUND: Persistent acute kidney injury (AKI) portends worse clinical outcomes and remains a therapeutic challenge for clinicians. A recent study found that urinary C-C motif chemokine ligand 14 (CCL14) can predict the development of persistent AKI. We aimed to externally validate urinary CCL14 for the prediction of persistent AKI in critically ill patients. METHODS: This was a secondary analysis of the prospective multi-center SAPPHIRE study. We evaluated critically ill patients with cardiac and/or respiratory dysfunction who developed Kidney Disease: Improving Global Outcomes (KDIGO) stage 2-3 AKI within one week of enrollment. The main exposure was the urinary concentration of CCL14 measured at the onset of AKI stage 2-3. The primary endpoint was the development of persistent severe AKI, defined as ≥ 72 h of KDIGO stage 3 AKI or death or renal-replacement therapy (RRT) prior to 72 h. The secondary endpoint was a composite of RRT and/or death by 90 days. We used receiver operating characteristic (ROC) curve analysis to assess discriminative ability of urinary CCL14 for the development of persistent severe AKI and multivariate analysis to compare tertiles of urinary CCL14 and outcomes. RESULTS: We included 195 patients who developed KDIGO stage 2-3 AKI. Of these, 28 (14%) developed persistent severe AKI, of whom 15 had AKI ≥ 72 h, 12 received RRT and 1 died prior to ≥ 72 h of KDIGO stage 3 AKI. Persistent severe AKI was associated with chronic kidney disease, diabetes mellitus, higher non-renal APACHE III score, greater fluid balance, vasopressor use, and greater change in baseline serum creatinine. The AUC for urinary CCL14 to predict persistent severe AKI was 0.81 (95% CI, 0.72-0.89). The risk of persistent severe AKI increased with higher values of urinary CCL14. RRT and/or death at 90 days increased within tertiles of urinary CCL14 concentration. CONCLUSIONS: This secondary analysis externally validates urinary CCL14 to predict persistent severe AKI in critically ill patients.

CCL14 testing to guide clinical practice in patients with AKI: Results from an international expert panel.

PURPOSE: Urinary C-C motif chemokine ligand 14 (CCL14) is a strong predictor of persistent stage 3 acute kidney injury (AKI). Multiple clinical actions are recommended for AKI but how these are applied in individual patients and how the CCL14 test results may impact their application is unknown. METHODS: We assembled an international panel of 12 experts and conducted a modified Delphi process to evaluate patients at risk for persistent stage 3 AKI (lasting 72 hours or longer). Using a Likert scale, we rated 11 clinical actions based on international guidelines applied to each case before and after CCL14 testing and analyzed the association between the strength and direction of recommendations and CCL14 results. RESULTS: The strength and direction of clinical recommendations were strongly influenced by CCL14 results (P < 0.001 for the interaction). Nine (82%) recommendations for clinical actions were significantly impacted by CCL14 results (P < 0.001 comparing low to highest CCL14 risk category). CONCLUSIONS: Most recommendations for care of patients with stage 2-3 by an international panel of experts were strongly modified by CCL14 test results. This work should set the stage for clinical practice protocols and studies to determine the effects of recommended actions informed by CCL14.

Serial Urinary C-C Motif Chemokine Ligand 14 and Risk of Persistent Severe Acute Kidney Injury.

To assess the added prognostic value of serial monitoring of urinary C-C motif chemokine ligand 14 (uCCL14) over that of single measurements, which have been shown to be prognostic for development of persistent severe acute kidney injury (AKI) in critically ill patients. DESIGN: Retrospective observational study. SETTING: Data derived from two multinational ICU studies (Ruby and Sapphire). PATIENTS: Critically ill patients with early stage 2-3 AKI. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We analyzed three consecutive uCCL14 measurements at 12-hour intervals after diagnosis of stage 2-3 AKI by Kidney Disease Improving Global Outcomes criteria. Primary outcome was persistent severe AKI, defined as 72 consecutive hours of stage 3 AKI, death, or receipt of dialysis prior to 72 hours. uCCL14 was measured using the NEPHROCLEAR uCCL14 Test on the Astute 140 Meter (Astute Medical, San Diego, CA). Based on predefined, validated cutoffs, we categorized uCCL14 as: low (≤ 1.3 ng/mL), medium (> 1.3 to ≤ 13 ng/mL), or high (> 13 ng/mL). Seventy-five of 417 patients with three consecutive uCCL14 measurements developed persistent severe AKI. Initial uCCL14 category strongly correlated with primary endpoint and, in most cases (66%), uCCL14 category was unchanged over the first 24 hours. Compared with no change and accounting for baseline category, decrease in category was associated with decreased odds of persistent severe AKI (odds ratio [OR], 0.20; 95% CI, 0.08-0.45; p < 0.001) and an increase in category with increased odds (OR, 4.04; 95% CI, 1.75-9.46; p = 0.001). CONCLUSIONS: In one-third of patients with moderate to severe AKI uCCL14 risk category altered over three serial measurements and such changes were associated with altered risk for persistent severe AKI. Serial CCL-14 measurement may detect progression or resolution of underlying kidney pathology and help refine AKI prognosis.

Fluorescence sensor for the quantification of unbound bilirubin concentrations.

BACKGROUND: Hyperbilirubinemia in jaundiced neonates is routinely assessed by use of total serum bilirubin. However, the unbound or free form (B(f)), not total bilirubin, crosses the blood-brain barrier and can be neurotoxic. Although the peroxidase-mediated oxidation of bilirubin can be used to measure plasma concentrations of B(f), this measurement is relatively complex and the assay is not routinely used. We describe a fluorescence sensor for quantifying B(f) in plasma. METHODS: Our method uses a mutated fatty acid binding protein labeled with the fluorescent molecule acrylodan (BL22P1B11), whose fluorescence is quenched upon binding bilirubin. Another configuration (BL22P1B11-Rh) was developed that uses BL22P1B11 together with the fluorophore rhodamine B, which responds by a change in the ratio of its fluorescence. RESULTS: The "B(f) probes" were calibrated with aqueous solutions of bilirubin and yielded similar bilirubin dissociation constants [K(d) = 16 (1.5) nmol/L]. We used the probes to determine B(f) concentrations in equilibrium with human serum albumin (HSA) and in human plasma samples supplemented with bilirubin. We obtained equivalent B(f) values in both systems, and the B(f) probe results were in agreement with the peroxidase assay. B(f) measurements revealed that bilirubin-HSA binding was well described by 2 sites with K(d) values of 15.4 (1) nmol/L and 748 (14) nmol/L. We measured B(f) concentrations in the range expected in jaundiced neonates with a mean CV of approximately 3%. CONCLUSIONS: The BL22P1B11-Rh probe provides accurate plasma sample B(f) concentrations with a single measurement, in 1 min with either a handheld B(f) meter or a laboratory fluorometer.

Performance of a Standardized Clinical Assay for Urinary C-C Motif Chemokine Ligand 14 (CCL14) for Persistent Severe Acute Kidney Injury.

Background: Clinical use of biomarkers requires the development of standardized assays and establishment of cutoffs. Urinary C-C motif chemokine ligand 14 (CCL14) has been validated to predict persistent severe AKI in critically ill patients with established AKI. We now report on the performance of standardized cutoffs using a clinical assay. Methods: A second aim of the multicenter RUBY Study was to establish two cutoffs for the prediction of persistent severe AKI (defined as KDIGO stage 3 AKI for at least 72 consecutive hours). Patients who received renal replacement therapy (RRT) or died before achieving 72 hours in stage 3 AKI were also considered to have reached the end point. Results: A cutoff value for urinary CCL14 of 1.3 ng/ml was determined to achieve high sensitivity (91%; 95% CI, 84% to 96%), and 13 ng/ml achieved high specificity (93%; 95% CI, 89% to 96%). The cutoff of 1.3 ng/ml identifies the majority (91%) of patients who developed persistent severe AKI with a negative predictive value of 92%. The cutoff at 13 ng/ml had a positive predictive value of 72% (with a negative predictive value of 75%). In multivariable adjusted analyses, a CCL14 concentration between 1.3 and 13 ng/ml had an adjusted odds ratio (aOR) of 3.82 (95% CI, 1.73 to 9.12; P=0.001) for the development of persistent severe AKI compared with those with a CCL14 ≤1.3 ng/ml, whereas a CCL14 >13 ng/ml had an aOR of 10.4 (95% CI, 3.89 to 29.9; P<0.001). Conclusions: Using a clinical assay, these standardized cutoffs (1.3 and 13 ng/ml) allow for the identification of patients at high risk for the development of persistent severe AKI. These results have immediate utility in helping to guide AKI patient care and may facilitate future clinical trials.Clinical Trial registry name and registration number: Identification and Validation of Biomarkers of Acute Kidney Injury Recovery, NCT01868724.

Selectively biorefining astaxanthin and triacylglycerol co-products from microalgae with supercritical carbon dioxide extraction.

Clustering behavior of supercritical carbon dioxide, triacylglycerides, and astaxanthin solutes were analyzed using Kamlet-Taft solvatochromic properties of dipolarity/polarizability, π∗, and hydrogen-bond acceptance, ß. Both parameters were decreased for supercritical carbon dioxide with TAG at low densities and with astaxanthin at high densities. These results indicated supercritical carbon dioxide could selectively extract triacylglycerides at low densities followed by astaxanthin at higher densities from microalgae. Accordingly, Haematococcus pluvialis microalgae were subject to a two-stage continuous extraction scheme where a density of 642 mg/ml was employed to extract triacylglycerides followed by a density of 971 mg/ml, by an increase in pressure, to extract astaxanthin. The first, lower density extract yielded over 78% of the total triacylglycerides and was composed of less than 1% astaxanthin. The sequential, higher density extract yielded less than 5% of the total microalgae triacylglycerides, over 70% of the total astaxanthin, and was composed of 60-76% astaxanthin by mass.

Temporal and spatial distribution of macrophage phenotype markers in the foreign body response to glutaraldehyde-crosslinked gelatin hydrogels.

Currently, it is not well understood how changes in biomaterial properties affect the foreign body response (FBR) or macrophage behavior. Because failed attempts at biomaterial degradation by macrophages have been linked to frustrated phagocytosis, a defining feature of the FBR, we hypothesized that increased hydrogel crosslinking density (and decreased degradability) would exacerbate the FBR. Gelatin hydrogels were crosslinked with glutaraldehyde (0.05, 0.1, and 0.3%) and implanted subcutaneously in C57BL/6 mice over the course of 3 weeks. Interestingly, changes in hydrogel crosslinking did not affect the thickness of the fibrous capsule surrounding the hydrogels, expression of the pan-macrophage marker F480, expression of three macrophage phenotype markers (iNOS, Arg1, CD163), or expression of the myofibroblast marker aSMA, determined using semi-quantitative immunohistochemical analysis. With respect to temporal changes, the level of expression of the M1 marker (iNOS) remained relatively constant throughout the study, while the M2 markers Arg1 and CD163 increased over time. Expression of these M2 markers was highly correlated with fibrous capsule thickness. Differences in spatial distribution of staining also were noted, with the strongest staining for iNOS at the hydrogel surface and increasing expression of the myofibroblast marker aSMA toward the outer edge of the fibrous capsule. These results confirm previous reports that macrophages in the FBR exhibit characteristics of both M1 and M2 phenotypes. Understanding the effects (or lack of effects) of biomaterial properties on the FBR and macrophage phenotype may aid in the rational design of biomaterials to integrate with surrounding tissue.

Usefulness of serum unbound free fatty acid levels to predict death early in patients with ST-segment elevation myocardial infarction (from the Thrombolysis In Myocardial Infarction [TIMI] II trial).

Circulating total free fatty acid (FFA) levels are elevated early in myocardial infarction (MI) and have been associated with an increase in mortality. We investigated the association of serum unbound FFA (FFAu) levels with mortality in patients presenting with ST-segment elevation MI in the Thrombolysis In Myocardial Infarction II trial. The Thrombolysis In Myocardial Infarction II trial enrolled patients within 4 hours of chest pain onset. The patients were treated with a recombinant tissue plasminogen activator within 1 hour of enrollment. The FFAu concentration was evaluated in serum samples from 1,834 patients obtained at baseline, before therapy. The FFAu level was an independent risk factor for death as early as at 1 day of hospitalization and continued to be an independent risk factor for the >3.8 years of follow-up. When adjusted for other cardiovascular risk factors, the FFAu levels in the fourth versus the first quartile remained an independent risk factor for death from MI (hazard ratio 5.0, 95% confidence interval 1.9 to 13.0), all cardiac death (hazard ratio 2.4, 95% confidence interval 1.3 to 4.4), and all-cause death (hazard ratio 1.9, 95% confidence interval 1.2 to 3.1). Women were twice as likely to be in the upper 2 FFAu quartiles and had approximately twice the rate of death as men. In conclusion, FFAu elevation is 1 of the earliest molecular biomarkers of mortality in patients with ST-segment elevation MI and was independent of other risk factors known to affect the outcomes after ST-segment elevation MI.

Scaling laws for ignition at the National Ignition Facility from first principles.

We have developed an analytical physics model from fundamental physics principles and used the reduced one-dimensional model to derive a thermonuclear ignition criterion and implosion energy scaling laws applicable to inertial confinement fusion capsules. The scaling laws relate the fuel pressure and the minimum implosion energy required for ignition to the peak implosion velocity and the equation of state of the pusher and the hot fuel. When a specific low-entropy adiabat path is used for the cold fuel, our scaling laws recover the ignition threshold factor dependence on the implosion velocity, but when a high-entropy adiabat path is chosen, the model agrees with recent measurements.

The development of enabling technologies for producing active interrogation beams.

A U.S./Russian collaboration of accelerator scientists was directed to the development of high averaged-current (∼1 mA) and high-quality (emittance ∼15 πmm mrad; energy spread ∼0.1%) 1.75 MeV proton beams to produce active interrogation beams that could be applied to counterterrorism. Several accelerator technologies were investigated. These included an electrostatic tandem accelerator of novel design, a compact cyclotron, and a storage ring with energy compensation and electron cooling. Production targets capable of withstanding the beam power levels were designed, fabricated, and tested. The cyclotron/storage-ring system was theoretically studied and computationally designed, and the electrostatic vacuum tandem accelerator at BINP was demonstrated for its potential in active interrogation of explosives and special nuclear materials.

Fatty acid-specific fluorescent probes and their use in resolving mixtures of unbound free fatty acids in equilibrium with albumin.

We report the first measurements for profiling mixtures of unbound free fatty acids. Measurements utilized fluorescent probes with distinctly different response profiles for different free fatty acids (FFA). These probes were constructed by labeling site-specific mutants of the rat intestinal fatty acid binding protein (rI-FABP) with acrylodan. The probes were produced and screened by high-throughput methods, and from more than 30 000 such probes we selected six that together have sufficient specificity and sensitivity for resolving the profile of unbound FFA (FFAu) in mixtures of different FFAu. We developed analytical methods to determine the FFAu profile from the fluorescence (ratio) response of the different probes and used these methods to determine FFAu profiles for mixtures of arachidonate, linoleate, oleate, palmitate, and stearate in equilibrium with bovine serum albumin (BSA). Measurements were performed using mixtures with a range of total FFAu concentrations, including 0.9 nM, which is similar to normal plasma levels. We also measured single FFA binding isotherms for BSA and found that binding was described well by six to seven sites with the same binding constants (Kd). The Kd values for the FFA (4-38 nM) were inversely related to the aqueous solubility of the FFA. We constructed a model with these parameters to predict the FFAu profile in equilibrium with BSA and found excellent agreement between the profiles measured using the FFA probes and those calculated with this model. These results should lead to a better understanding of albumin's role in buffering FFAu and to profiling FFAu in intra- and extracellular biological fluids.