Arterial stiffness for the early prediction of pre-eclampsia compared with blood pressure, uterine artery Doppler and angiogenic biomarkers: a prospective cohort study

OBJECTIVE

Our aim was to evaluate the ability of arterial stiffness parameters to predict pre-eclampsia early compared with peripheral blood pressure, uterine artery Doppler and established angiogenic biomarkers.

DESIGN

Prospective cohort study.

SETTING

Tertiary care antenatal clinics in Montreal, Canada.

POPULATION

Women with singleton high-risk pregnancies.

METHODS

In the first trimester, arterial stiffness was measured by applanation tonometry, along with peripheral blood pressure and serum/plasma angiogenic biomarkers; uterine artery Doppler was measured in the second trimester. The predictive ability of different metrics was assessed through multivariate logistic regression.

MAIN OUTCOME MEASURES

Arterial stiffness (carotid-femoral pulse wave velocity, carotid-radial pulse wave velocity) and wave reflection (augmentation index, reflected wave start time), peripheral blood pressure, ultrasound indices of velocimetry and circulating angiogenic biomarker concentrations.

RESULTS

In this prospective study, among 191 high-risk pregnant women, 14 (7.3%) developed pre-eclampsia. A first-trimester 1 m/s increase in carotid-femoral pulse wave velocity was associated with 64% increased odds (P < 0.05), and a 1-millisecond increase in time to wave reflection with 11% decreased odds for pre-eclampsia (P < 0.01). The area under the curve of arterial stiffness, blood pressure, ultrasound indices and angiogenic biomarkers was 0.83 (95% confidence interval [CI] 0.74-0.92), 0.71 (95% CI 0.57-0.86), 0.58 (95% CI 0.39-0.77), and 0.64 (95% CI 0.44-0.83), respectively. With a 5% false-positive rate, blood pressure had a sensitivity of 14% for pre-eclampsia and arterial stiffness a sensitivity of 36%.

CONCLUSIONS

Arterial stiffness predicted pre-eclampsia earlier and with greater ability than blood pressure, ultrasound indices or angiogenic biomarkers.

Advanced practice physiotherapy care in emergency departments for patients with musculoskeletal disorders: a pragmatic cluster randomized controlled trial and cost analysis

BACKGROUND

Advanced practice physiotherapy (APP) models of care where physiotherapists are primary contact emergency department (ED) providers are promising models of care to improve access, alleviate physicians' burden, and offer efficient centered patient care for patients with minor musculoskeletal disorders (MSKD).

OBJECTIVES

To compare the effectiveness of an advanced practice physiotherapist (APPT)-led model of care with usual ED physician care for persons presenting with a minor MSKD, in terms of patient-related outcomes, health care resources utilization, and health care costs.

METHODS

This trial is a multicenter stepped-wedge cluster randomized controlled trial (RCT) with a cost analysis. Six Canadian EDs (clusters) will be randomized to a treatment sequence where patients will either be managed by an ED APPT or receive usual ED physician care. Seven hundred forty-four adults with a minor MSKD will be recruited. The main outcome measure will be the Brief Pain Inventory Questionnaire. Secondary measures will include validated self-reported disability questionnaires, the EQ-5D-5L, and other health care utilization outcomes such as prescription of imaging tests and medication. Adverse events and re-visits to the ED for the same complaint will also be monitored. Health care costs will be measured from the perspective of the public health care system using time-driven activity-based costing. Outcomes will be collected at inclusion, at ED discharge, and at 4, 12, and 26 weeks following the initial ED visit. Per-protocol and intention-to-treat analyses will be performed using linear mixed models with a random effect for cluster and fixed effect for time.

DISCUSSION

MSKD have a significant impact on health care systems. By providing innovative efficient pathways to access care, APP models of care could help relieve pressure in EDs while providing efficient care for adults with MSKD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05545917 . Registered on September 19, 2022.

Pulse-shape discrimination against low-energy Ar-39 beta decays in liquid argon with 4.5 tonne-years of DEAP-3600 data

The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.

0682 Evaluation Of An Incentive-based Intervention To Improve 90-day Adherence In Pap-naive Patients

Introduction

Although PAP therapy is the gold standard treatment for obstructive sleep apnea, adherence to treatment is suboptimal. Without sustained therapy adherence, patients are at risk of serious negative health outcomes. The objective of this study was to test whether a digitally delivered monetary and social reward program helped patients new to PAP therapy. Financial incentive schemes are effective in helping patients adhere to difficult medication or therapy plans. Additionally, there is an abundance of evidence that social support is a critical component to long-term health behavior change.

Methods

This prospective, randomized, single site pilot is evaluating the effectiveness of an app-based intervention in helping patients adhere to PAP therapy. The financial incentive design leverages loss aversion, and the social incentive design leverages the strength of close ties and variable reinforcement. The primary endpoint is mean PAP usage at 3 months. Secondary endpoints include Medicare compliance, change in functional status, and baseline scores of perceived disease severity, claustrophobia, coping skills, and health literacy as moderators of the intervention’s effectiveness. Study recruitment is ongoing, with an expected sample size of 150 subjects.

Results

Of the 132 subjects enrolled, 56% are male, 61% are Caucasian, and 65% are married. The mean age is 49.6 ± 12.0 years and mean BMI is 32.4 ± 8.4 kg/m2. Additional demographics such as income level, education level, and number of children along with the primary and secondary endpoints will be presented. A subgroup analysis of the primary endpoint will be generated for subjects identified as strugglers within the first 3 days of usage.

Conclusion

The results of this study will provide insight into methods such as financial and social incentives delivered via a smartphone on initial compliance with PAP therapy, as well as provide more information on the behavioral change associated with beginning PAP therapy.

Support

ResMed

First Results from the DEAP-3600 Dark Matter Search with Argon at SNOLAB

This Letter reports the first results of a direct dark matter search with the DEAP-3600 single-phase liquid argon (LAr) detector. The experiment was performed 2 km underground at SNOLAB (Sudbury, Canada) utilizing a large target mass, with the LAr target contained in a spherical acrylic vessel of 3600 kg capacity. The LAr is viewed by an array of PMTs, which would register scintillation light produced by rare nuclear recoil signals induced by dark matter particle scattering. An analysis of 4.44 live days (fiducial exposure of 9.87 ton day) of data taken during the initial filling phase demonstrates the best electronic recoil rejection using pulse-shape discrimination in argon, with leakage <1.2×10^{-7} (90% C.L.) between 15 and 31  keV_{ee}. No candidate signal events are observed, which results in the leading limit on weakly interacting massive particle (WIMP)-nucleon spin-independent cross section on argon, <1.2×10^{-44}  cm^{2} for a 100  GeV/c^{2} WIMP mass (90% C.L.).

Abstract P3-07-08: Quantitative HER family proteins assessment as prognostic and predictive biomarkers in the EGF30008 clinical trial

Background

Combined targeted strategy with letrozole (Le) and lapatinib (La) improves progression-free survival (PFS) in patients with metastatic breast cancer (MBC) co-expressing hormone receptor-positive (HR+) and HER2+ but not in HR+/HER2-negative (HER-) disease (Johnston J Clin Oncol 2009). However, among HER2+ tumors, quantitative levels of HER2 are heterogeneous with a broad dynamic range corresponding to approximately 163.7 to 17446.7 amol/µg as previously reported (Nuciforo SABCS 2014). In addition, within HER2- tumors, quantitative measurement of HER family proteins may identify those patients most likely to benefit from the addition of La to Le. In this retrospective study, we tested the prognostic and predictive ability of HER proteins quantification in clinically HER2+ tumor samples from the EGF30008 study.

Methods

Formalin-fixed paraffin-embedded primary tumor tissues sections from HER2+ MBC population were used. After laser microdissection, tissue lysates were prepared for selected reaction monitoring mass spectrometry (SRM-MS) analysis. Absolute quantitation was accomplished through simultaneous detection of endogenous target and synthetic labeled heavy peptide identical to analytical targets (EGFR, HER2, HER3). HER2 protein levels were correlated with PAM50 molecular subtypes, ERBB2 and ESR1 genes by nCounter. PFS and overall survival (OS) were analyzed by Kaplan–Meier and log-rank test. To determine whether HER2 protein levels were predictive of La benefit, we tested the interaction term of HER2 protein as a continuous variable by treatment arm in a Cox model.

Results

Within the HER2+ study cohort (n=219), 107 had an available tumor block; 84 cases had sufficient material for HER expression measurement by SRM-MS. Average HER2 levels were

2321.1 amol/ug (median, 817.6). HER2 levels were lower in Le+La (n=43; mean, 1761 amol/ug) compared to Le (n=41; mean, 2908 amol/ug) arms, although the difference was non-significant (p=0.108). No expression of EGFR and HER3 was observed. HER2 protein levels were significantly different among PAM50 subtypes with HER2-enriched (HER2E) tumors showing the highest expression followed by Basal-like, Luminal A, Luminal B, and Normal-like (p&lt;0.001). A correlation between HER2 protein, ERBB2 (r=0.5, p&lt;0.001) and ESR1 (r=-0.5, p=0.001) gene expression was found. In patients with disease that expresses HER2 protein levels above the median a trend towards worse PFS (2.9 vs 7.7 months, p=0.092) and OS (21 vs 39 months, p=0.071) were observed. A statistically significant interaction was observed between HER2 protein levels and La treatment for both PFS (p=0.049) and OS (p&lt;0.001). HER2+ tumors with lower expression of HER2 benefited more from La than those with higher expression.

Conclusions

Levels of HER2 protein in HER2+ MBC are extremely heterogeneous. An association between HER2 protein and gene expression by nCounter was observed. HER2E tumors by PAM50 showed the highest levels of HER2 protein. Within the group of HER2+ MBC by standard IHC/FISH, tumors with high HER2 protein had a statistically non-significant worse outcome and do not seem to benefit from La. Further validation of these findings is warranted.

Citation Format: Nuciforo P, Thyparambil S, Galván P, Vilaro M, Jimenez J, Liao W-L, Cecchi F, Blackler A, Press MF, Gagnon R, Ellis C, Hembrough T, Johnston S, Prat A. Quantitative HER family proteins assessment as prognostic and predictive biomarkers in the EGF30008 clinical trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-08.

Abstract P2-08-16: Prognostic and predictive abilities of intrinsic subtype in hormone receptor-positive metastatic breast cancer from the EGF30008 phase III clinical trial

Background

Combination of letrozole and lapatinib improved progression-free survival (PFS) compared with letrozole and placebo in patients with hormone receptor-positive (HR+)/HER2+ metastatic breast cancer (MBC), but not HR+/HER2-negative (HER2-) disease (JCO 2009). However, HR+ disease is clinically and biologically heterogeneous with all intrinsic molecular subtypes (Luminal A, Luminal B, HER2-enriched [HER2E] and Basal-like) identified. Here, we tested retrospectively the prognostic and predictive ability of intrinsic subtype in tumor samples of the EGF30008 trial.

Methods

Expression profiling from FFPE tumor tissues was performed on the nCounter platform. Tumors were classified into each intrinsic subtype using the research-based PAM50 classifier (JCO 2009). Cox proportional hazard models for PFS and overall survival (OS) were used to generate point estimates of hazard ratios (HR) and corresponding 95% confidence intervals (CIs). Changes in likelihood ratio χ2 values were used to measure and compare the relative amount of information of each variable. Variables evaluated were: age, prior endocrine therapy, presence of visceral disease, number of metastatic sites, performance status, clinical HER2 status, and treatment. To determine whether the intrinsic subtypes were predictive of lapatinib benefit, we tested the interaction term of subtype by treatment arm in a Cox model that also included the main effects. Kaplan-Meier plots were used to depict the proportion of patients free from progression as a function of time.

Results

Tumor samples from 821 patients (63.8%) were profiled (85.7% primary and 14.3% metastatic tumor samples). Clinical-pathological features of this patient subset were well balanced compared with the original set. Within the entire cohort, all subtypes were identified: Luminal A (46.5%); Luminal B (29.7%); HER2E (7.4%); Basal-like (3.4%) and normal-like (12.9%). Within HER2+ disease, 28.6% of samples were HER2E. Intrinsic subtype was found the strongest prognostic factor independently associated with PFS and OS in all patients, and in patientswith HER2-negative or HER2+ disease (P&lt;0.0001). Median PFS and OS for each subtype within clinically HER2-negative disease were: Luminal A (16.85 and 45.0 months), Luminal B (10.97 and 37.0 months), HER2E (4.67 and 16.0 months) and Basal-like (4.14 and 23.0 months). Within clinically HER2-negative disease (n=644), 16 patients (2.5%) had HER2E disease. Patients with HER2-/HER2E disease benefited from lapatinib (6.5 vs 2.6 months; PFS HR =0.24, 95% CI: 0.07-0.86; P=0.019; HER2E vs not treatment interaction P=0.016). Finally, intrinsic subtype was not predictive of benefit from lapatinib within HER2+ disease.

Conclusions

HR-positive disease is biologically heterogeneous and intrinsic subtypes are strongly prognostic in a first-line MBC setting. HR+/HER2- disease with a HER2E profile may benefit from lapatinib. The clinical value of intrinsic subtyping in HR+ MBC warrants further investigation, but patients with Luminal A/HER2-negative MBC disease might be good candidates for letrozole monotherapy in the first-line setting regardless of visceral disease and number of metastases.

Citation Format: Prat A, Cheang MCU, Galván P, Nuciforo P, Paré L, Adamo B, Viladot M, Press MF, Gagnon R, Ellis C, Johnston S. Prognostic and predictive abilities of intrinsic subtype in hormone receptor-positive metastatic breast cancer from the EGF30008 phase III clinical trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-16.

Assessment of urinary metabolite excretion after rat acute exposure to perfluorooctanoic acid and other peroxisomal proliferators

Perfluorooctanoic acid (PFOA) is a persistent environmental contaminant. Activation of the peroxisome proliferator activated receptor alpha (PPARα) resulting from exposure to PFOA has been extensively studied in rodents. However, marked differences in response to peroxisome proliferators prevent extrapolation of rodent PPARα activation to human health risks and additional molecular mechanisms may also be involved in the biological response to PFOA exposure. To further explore the potential involvement of such additional pathways, the effects of PFOA exposure on urinary metabolites were directly compared with those of other well-known PPARα agonists. Male rats were administered PFOA (10, 33, or 100 mg/kg/d), fenofibrate (100 mg/kg/d), or di(2-ethylhexyl) phthalate (100 mg/kg/d) by gavage for 3 consecutive days and allowed to recover for 4 days, and overnight urine was collected. Greater urinary output was observed exclusively in PFOA-treated rats as the total fraction of PFOA excreted in urine increased with the dose administered. Assessment of urinary metabolites (ascorbic acid, quinolinic acid, 8-hydroxy-2'-deoxyguanosine, and malondialdehyde) provided additional information on PFOA's effects on hepatic glucuronic acid and tryptophan-nicotinamide adenine dinucleotide (NAD) pathways and on oxidative stress, whereas increased liver weight and palmitoyl-CoA oxidase activity indicative of PPARα activation and peroxisomal proliferation persisted up to day five after the last exposure.

Identification of the Hydroxamate Siderophore Ferricrocin in Cladosporium cladosporioides

The hydroxamate siderophore ferricrocin was identified in Cladosporium cladosporioides growth medium by solid phase extraction and ultra high pressure liquid chromatography coupled to a time of flight mass spectrometer (UHPLC/QTOF-MS). Both desferricrocin and ferricrocin were detected in the extracellular medium assisted by high resolution mass spectrometry. This is the first identification of a hydroxamate siderophore in Cladosporium cladosporioides. This finding emphasizes the common meaning of ferricrocin in fungi.

Identification of the hydroxamate siderophore ferricrocin in Cladosporium cladosporioides

The hydroxamate siderophore ferricrocin was identified in Cladosporium cladosporioides growth medium by solid phase extraction and ultra high pressure liquid chromatography coupled to a time of flight mass spectrometer (UHPLC/QTOF-MS). Both desferricrocin and ferricrocin were detected in the extracellular medium assisted by high resolution mass spectrometry. This is the first identification of a hydroxamate siderophore in Cladosporium cladosporioides. This finding emphasizes the common meaning of ferricrocin in fungi.

A metabolomic study reveals novel plasma lyso-Gb3 analogs as Fabry disease biomarkers

Fabry disease is an X-linked, multisystemic lysosomal storage disorder due to alpha-galactosidase A deficiency. It is characterized by the accumulation of glycosphingolipids, mainly globotriaosylceramide (Gb(3)), in biological fluids, vascular endothelium, heart, and kidneys. Treatment by enzyme replacement therapy has been shown to be beneficial in both males and females affected with the disease. In addition to Gb(3), increased concentrations of globotriaosylsphingosine (lyso-Gb(3)) have recently been reported in urine and plasma of Fabry patients. The overall objective of this metabolomic study was to identify and characterize new potential plasma biomarkers in treated and untreated males and females affected with Fabry disease which might better reflect disease severity and progression. We employed a time-of-flight mass spectrometry metabolomic approach using plasma samples of Fabry patients compared to age-matched controls. We found three new lyso-Gb(3) analogs in Fabry patients presenting m/z ratios at 802, 804, and 820. As previously detected by our group, we also found a m/z ratio of 784 corresponding to the lyso-Gb(3) molecule minus two hydrogen atoms. Using exact mass measurements and tandem mass spectrometry, we confirmed that these analogs result from modifications of the lyso-Gb(3) sphingosine moiety. We evaluated the relative plasma concentration by measuring area counts for each lyso-Gb(3) analog. None of these analogs was detected in the majority of healthy controls. The relative concentration of each analog was higher in males compared to female Fabry patients. We demonstrated that mass spectrometry combined to a metabolomic approach is a powerful tool to detect and identify new potential biomarkers.

Effect of alipogene tiparvovec (AAV1-LPL(S447X)) on postprandial chylomicron metabolism in lipoprotein lipase-deficient patients

BACKGROUND

Lipoprotein lipase-deficient (LPLD) individuals display marked chylomicronemia and hypertriglyceridemia associated with increased pancreatitis risk. The aim of this study was to determine the effect of i.m. administration of an adeno-associated viral vector (AAV1) for expression of LPL(S447X) in muscle (alipogene tiparvovec, AAV1-LPL(S447X)) on postprandial chylomicron metabolism and on nonesterified fatty acid (NEFA) and glycerol metabolism in LPLD individuals.

METHODOLOGY

In an open-label clinical trial (CT-AMT-011-02), LPLD subjects were administered alipogene tiparvovec at a dose of 1 × 10(12) genome copies per kilogram. Two weeks before and 14 wk after administration, chylomicron metabolism and plasma palmitate and glycerol appearance rates were determined after ingestion of a low-fat meal containing (3)H-palmitate, combined with (continuous) iv infusion of [U-(13)C]palmitate and [1,1,2,3,3-(2)H]glycerol.

PRINCIPAL FINDINGS

After administration of alipogene tiparvovec, the triglyceride (TG) content of the chylomicron fraction and the chylomicron-TG/total plasma TG ratio were reduced throughout the postprandial period. The postprandial peak chylomicron (3)H level and chylomicron (3)H area under the curve were greatly reduced (by 79 and 93%, 6 and 24 h after the test meal, respectively). There were no significant changes in plasma NEFA and glycerol appearance rates. Plasma glucose, insulin, and C-peptide also did not change.

CONCLUSIONS/SIGNIFICANCE

Intramuscular administration of alipogene tiparvovec resulted in a significant improvement of postprandial chylomicron metabolism in LPLD patients, without inducing large postprandial NEFA spillover.

Urinary globotriaosylsphingosine-related biomarkers for Fabry disease targeted by metabolomics

Fabry disease is a lysosomal storage disorder caused by deficiency of α-galactosidase A, resulting in glycosphingolipid accumulation in organs and tissues, including plasma and urine. Two disease-specific Fabry biomarkers have been identified and quantified in plasma and urine: globotriaosylceramide (Gb(3)) and globotriaosylsphingosine (lyso-Gb(3)). The search continues for biomarkers that might be reliable indicators of disease severity and response to treatment. The main objective of this study was to target other urinary biomarkers using a time-of-flight mass spectrometry metabolomic approach. Urinary metabolites of 63 untreated Fabry patients and 59 controls were analyzed. A multivariate statistical analysis performed on a subset of male samples revealed seven novel Fabry biomarkers in urine, all lyso-Gb(3) analogues having modified sphingosine moieties. The empirical formulas of the sphingosine modifications were determined by exact mass measurements (- C(2)H(4), - C(2)H(4) + O, - H(2), - H(2) + O, + O, + H(2)O(2), + H(2)O(3)). We evaluated the relative concentration of lyso-Gb(3) and its seven analogues by measuring area counts for each analogue in all Fabry patients. All samples were normalized to creatinine. We found higher concentrations for males with Fabry disease compared to females. None of these biomarkers were detected in controls. To our knowledge, this is the first time that lyso-Gb(3)-related Fabry disease biomarkers are detected in urine.

A deficit in peripheral serotonin levels in major depressive disorder but not in chronic widespread pain

OBJECTIVES

It has been proposed that serotonin dysfunctions underlie the pathophysiology of various mood disorders (including major depressive disorder, MDD) and chronic pain conditions characterized by deficient pain inhibition, such as fibromyalgia (FM). There is reliable data showing that serotonin disturbances are involved in the pathophysiology of MDD. However, in the case of FM, results published so far are less consistent. Therefore, the current cross-sectional study sought to measure plasma serotonin levels in FM patients, MDD patients, and healthy controls (HC).

METHODS

Twenty-nine FM patients, 17 MDD patients, and 57 HC were recruited who did not differ in terms of age, sex, and the presence or absence of a regular menstrual cycle. Plasma samples were analysed with mass spectrometry.

RESULTS

Serotonin levels were decreased in MDD patients, relative to FM patients and HC. Post hoc analyses showed that serotonin levels were decreased in FM patients taking antidepressants, relative to HC, but not in drug-free FM patients. Moreover, serotonin levels were negatively correlated with mood symptoms across groups.

DISCUSSION

Our results further confirm that MDD is associated with decreased serotonin levels, but that serotonin levels are not altered in FM per se, and suggest that 5-Hydroxytryptamine is related to mood symptoms in these patient groups. Our results also suggest that the taking of antidepressant is a major confound to consider when studying serotonin functioning in FM. The long-term use of antidepressants in FM may lead to serotonin depletion. Conversely, serotonin depletion may be before the taking of antidepressants in FM.

Feasibility of vesicoamniotic shunt insertion in an inanimate model: comparison of fetoscopic and ultrasound-guided techniques

OBJECTIVES

To determine the feasibility of fetoscopic vesicoamniotic shunt insertion (F-VASI) in an inanimate model and to compare F-VASI to ultrasound (US)-guided VASI (US-VASI) with respect to accuracy of shunt placement and overall success rate.

METHODS

An inanimate second-trimester fetus with a replaceable bladder balloon was suspended in a pressurized water tank and localized with US. Fetal position was randomized, the operator was blinded and a 5-Fr Harrison Shunt® decompressed the bladder in both groups. Thirty shunt insertions were performed per group.

RESULTS

Procedure time was longer for F-VASI (15.0 vs. 2.8 min, p < 0.05), although it decreased with practice. F-VASI and US-VASI were similar for adequate depth of insertion (27/30 vs. 27/30, p = 1.0), placement within 1 cm of midline (27/30 vs. 25/30, p = 0.42), bladder puncture (28/30 vs. 28/30, p = 1.0), and overall success rate (27/30 vs. 23/30, p = 0.3).

CONCLUSIONS

F-VASI is feasible in an inanimate model. Overall success rate was similar between the groups, although procedure time was longer for F-VASI. Further study is required to determine whether shunt migration is decreased with F-VASI.

Efficient analysis of urinary glycosaminoglycans by LC-MS/MS in mucopolysaccharidoses type I, II and VI

Mucopolysaccharidoses (MPSs) are complex storage disorders caused by specific lysosomal enzyme deficiencies, resulting in the accumulation of glycosaminoglycans (GAGs) in urine, plasma, as well as in various tissues. We devised and validated a straightforward, but accurate and precise tandem mass spectrometry methodology coupled to high performance liquid chromatography (LC-MS/MS) for the quantification of GAGs in urine. The method is applicable to the investigation of patients with MPS I, II, and VI, by quantifying dermatan sulfate (DS) and heparan sulfate (HS) in urine. We analyzed urine samples from 28 MPS patients, aged 1 to 42 years, and 55 control subjects (41 days to 18 years old). Levels of DS and HS in urine from healthy controls of all ages were below the limit of quantification. The levels of DS and HS in urine from 6 treated patients with MPS I were lower than in 6 untreated patients in DS (0.7-45 vs 9.3-177 mg/mmol creat) and HS (0-123 mg/mmol creatinine vs 38-418 mg/mmol creatinine); similar results were obtained for 9 patients with MPS II and 7 patients with MPS VI. Analyses were performed on as little as 250 μL of urine. Methanolysis took 75 min per sample; the total analysis run time for each LC-MS/MS injection was 8 min. Results indicate that the method is applicable to a wide variety of situations in which high accuracy and precision are required, including the evaluation of the effectiveness of existing and emerging treatments.

How well does urinary lyso-Gb3 function as a biomarker in Fabry disease?

BACKGROUND

Fabry disease is characterized by accumulation of glycosphingolipids, such as globotriaosylceramide (Gb(3)), in many tissues and body fluids. A novel plasma biomarker, globotriaosylsphingosine (lyso-Gb(3)), is increased in patients with the disease. Until now, lyso-Gb(3) was not detectable in urine, possibly because of the presence of interfering compounds.

METHODS

We undertook to: 1) characterize lyso-Gb(3) in urine; 2) develop a method to quantitate urinary lyso-Gb(3) by mass spectrometry; 3) evaluate urinary lyso-Gb(3) as a potential biomarker for Fabry disease; and 4) determine whether lyso-Gb(3) is an inhibitor of α-galactosidase A activity. We analyzed urinary lyso-Gb(3) from 83 Fabry patients and 77 healthy age-matched controls.

RESULTS

The intraday and interday bias and precision of the method were <15%. Increases in lyso-Gb(3)/creatinine correlated with the concentrations of Gb(3) (r(2)=0.43), type of mutations (p=0.0006), gender (p<0.0001) and enzyme replacement therapy status (p=0.0012). Urine from healthy controls contained no detectable lyso-Gb(3). Lyso-Gb(3) did not inhibit GLA activity in dried blood spots. Increased urinary excretion of lyso-Gb(3) of Fabry patients correlated well with a number of indicators of disease severity.

CONCLUSION

Lyso-Gb(3) is a reliable independent biomarker for clinically important characteristics of Fabry disease.

Increased postprandial nonesterified fatty acid appearance and oxidation in type 2 diabetes is not fully established in offspring of diabetic subjects

Background

It has been proposed that abnormal postprandial plasma nonesterified fatty acid (NEFA) metabolism may participate in the development of tissue lipotoxicity and type 2 diabetes (T2D). We previously found that non-diabetic offspring of two parents with T2D display increased plasma NEFA appearance and oxidation rates during intravenous administration of a fat emulsion. However, it is currently unknown whether plasma NEFA appearance and oxidation are abnormal during the postprandial state in these subjects at high-risk of developing T2D.

Methodology

Palmitate appearance and oxidation rates and glycerol appearance rate were determined in eleven healthy offspring of two parents with T2D (positive family history, FH+), 13 healthy subjects without first-degree relatives with T2D (FH-) and 12 subjects with T2D at fasting, during normoglycemic hyperinsulinemic clamp and during continuous oral intake of a standard liquid meal to achieve steady postprandial NEFA and triacylglycerols (TG) without and with insulin infusion to maintain similar glycemia in all three groups.

Principal Findings

Plasma palmitate appearance and oxidation were higher at fasting and during the clamp conditions in the T2D group (all P<0.05). In the postprandial state, palmitate appearance, oxidative and non oxidative rates were all elevated in T2D (all P<0.05) but not in FH+. Both T2D and FH+ displayed elevated postprandial TG vs. FH- (P<0.001). Acute correction of hyperglycemia during the postprandial state did not affect these group differences. Increased waist circumference and BMI were positively associated with elevated postprandial plasma palmitate appearance and oxidation.

Conclusions/Significance

Postprandial plasma NEFA intolerance observed in subjects with T2D is not fully established in non-diabetic offspring of both parents with T2D, despite the presence of increased postprandial plasma TG in the later. Elevated postprandial plasma NEFA appearance and oxidation in T2D is observed despite acute correction of the exaggerated glycemic excursion in this group.

Frequency of PIK 3CA Mutations in Chinese HER2+ Metastatic Breast Cancer Patients and Association with Clinical Benefit to Lapatinib and Capecitabine Treatment

Background: Activating mutations in PIK3CA are frequent in breast cancer (Campbell et al. Cancer Res 2004;64:7678-7681). Previous analyses suggest that the presence of PIK3CA activating mutations were associated with poor clinical outcome (Li et al. Breast Can Res Treat 2006;96:91-95) and could confer resistance to treatment with trastuzumab (T) (Berns et al. Cancer Cell 2007;12:395-402). Lapatinib (L) is an oral tyrosine kinase inhibitor targeting EGFR and HER2 pathways. L plus capecitabine (C) has demonstrated efficacy in women with HER2+ metastatic breast cancer (MBC) previously treated with T (Geyer et al. N Engl J Med 2006;355(26):2733-2743). EGF109491 evaluated the efficacy of L+C in 52 Chinese HER2+ MBC patients. The clinical benefit rate (CBR) was 57.7% (PR 44% and SD 44%) and median progression free survival (PFS) was 6.3 months. The purpose of this analysis was to establish the frequency of PIK3CA mutations in this small cohort of Chinese patients and to determine if the presence of a PIK3CA mutation has any impact on clinical benefit to L+C.Methods: 38/52 patients provided tumor samples for biomarker analysis. Briefly, DNA was extracted from these tumor samples, amplified by PCR and sequenced by Pyrosequencing methods to identify the presence of frequent activating mutations in exons 9 and 20 in PIK3CA. Mutation status was tested for association with CBR and PFS using contingency table analysis and proportional hazards analysis respectively.Results:11/38 (29%) patients harbored a mutation in the PIK3CA gene, consistent with published frequencies. 9/11 mutations reside in the catalytic domain and 2/11 mutations reside in the accessory domain of the gene. There was no statistical association with CBR (p=0.639) or PFS (HR=1.01, p=0.989) in PIK3CA wildtype patients vs. PIK3CA mutant patients. PIK3CA wildtype n=27 (%)PIK3CA Mutation n=11 (%)CR0 (0)0 (0)PR12 (44%)4 (36%)SD13 (48%)5 (45%)PD1 (4%)1 (9%)Unknown1 (4%)1 (9%)HR1.01 (p=0.989) Conclusion: The frequency of PIK3CA mutations in this small cohort of Chinese HER2+ MBC patients is consistent with published frequencies. There was no statistically significant association between the presence of a PIK3CA mutation and clinical benefit to L+C in these patients. These results are in agreement with previous reports that mutations in PIK3CA do not seem to impact clinical outcome following L-containing treatment regimens.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1140.

Biomarker Profiles in Trastuzumab (T) Refractory HER2+ Inflammatory Breast Cancer (IBC) That Predict for Survival Benefit from Lapatinib (L) Monotherapy

Background:L is a reversible, oral small molecule inhibitor of EGFR and HER2. L demonstrated an objective response rate (ORR) of 39%, a median progression free survival (PFS) of 14.6 weeks and a median overall survival (OS) of 11.2 months in a monotherapy Phase II study of 126 patients (pts) with HER2+ IBC (Kaufman et al. Lancet Oncology, 2009). In the initial cohort of pts we reported an association between response to L and coexpression of pHER3 with pHER2 (Johnston et al, J Clin Oncol, 2008 26; 1066-72). In this study we measured a series of biomarkers in tumor biopsies obtained before the start of treatment and evaluated their association with parameters of clinical benefit to L in relation to prior T.Methods:Core needle biopsies were obtained pretreatment, preserved in phosphatase inhibitor buffer, fixed in formalin and embedded in paraffin. Baseline expression of total and activated EGFR, HER2, HER3 and downstream markers, as well as markers specific to IBC were determined by standard IHC techniques yielding manual and optical density (OD) scores. 94/126 pts received prior T treatment before beginning L treatment, while 32 patients were T naive. The baseline expression of each marker was tested for association with ORR, PFS and OS using proportional hazards and logistic regression models.Results:OD IHC data indicated pEGFR and TGFα had statistically significant association with OS and PFS in pts treated with prior T. pHER3 also appeared to be associated with OS, although was not statistically significant. Higher levels of these biomarkers were associated with decreased hazard of progression or death. Correlation between OD and manual scores (0,1,2,3) were highly significant for these markers (R=0.80, p&lt;0.0001). These markers were not significant when tested against ORR.[table 1] OSPFSORRpEGFR (N=56)P&lt;0.0001, HR=0.45P=0.0192,HR=0.66P=0.2721,OR=1.44pHER3 (N=71)P=0.0634, HR=0.74P=0.1256, HR=0.78P=0.0920, OR=1.72TGFα (N=57)P=0.0019, HR=0.95P=0.0386, HR=0.97P=0.8211, OR=1.05HR; Hazard Ratio, OR; Odds Ratio (odds of response)When we evaluated the same panel of biomarkers in T naïve pts, higher levels of HER2 expression were significantly associated with improved ORR (p=0.0186) and a trend towards significance with OS (p=0.0674). Furthermore, higher levels of pAKT (p=0.0068) and pERK (p=0.006) were significantly associated with improved OS.Discussion:L monotherapy is clinically active in the treatment of relapsed/refractory HER2+ IBC. Higher levels of pEGFR and TGFa by IHC are significantly associated with improved OS and PFS but not ORR in patients with prior T therapy. In contrast, T naïve pts, higher levels of pAKT and pERK showed a significant association with OS. Thus, different biomarker profiles may predict benefit in T naïve vs T-refractory pts benefiting from L monotherapy in HER2+ IBC.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 706.

Clinical benefit of lapatinib-based therapy in patients with HER2-positive breast tumors expressing p95HER2

1048

Background: Approximately 25% of HER2 overexpressing breast tumors express a truncated form of the receptor (p95HER2) that lacks the extracellular domain but retains kinase activity. p95HER2-positive tumors are associated with a worse prognosis and resistant to trastuzumab therapy. In preclinical models, lapatinib (L), a tyrosine kinase inhibitor of EGFR and HER2, is active in p95HER2 expressing tumors. The aim of this analysis was to test the hypothesis that benefit from L-based therapy is independent of p95HER2 expression in 2 clinical trials in patients (pts) with HER2-positive tumors treated with either L monotherapy (Study EGF20009 ) or L in combination with capecitabine (Study EGF100151). Methods: Pre-treatment tumor tissue from both trials (N=201) was analyzed for p95HER2 expression by immunofluorescence as previously described (Scaltriti M. et al, JNCI 2007). Expression of p95HER2 was correlated with clinical benefit rate (CBR: complete response [CR] + partial response [PR] + stable disease [SD] ≥ 24 weeks) and progression-free survival (PFS) using logistic regression and Cox-proportional hazard models. Results: 68/105 and an initial 72/96 tissue samples were evaluable for p95HER2 expression from studies EGF20009 and EGF100151, respectively. The Table summarizes the results from the L treated pts. The CBR and PFS in L treated pts were not significantly different between the p95HER2 subgroups. Expanded data for p95HER2 expression in additional EGF100151 tumor samples will be presented. Conclusions: L as a monotherapy or in combination with capecitabine has similar response activity in pts with p95HER2-positive and p95HER2-negative HER2-positive breast tumors.

[Table: see text]

[Table: see text]

Relevance of serum HER2 extracellular domain (sECD) in EGF30008, a study of letrozole ± lapatinib in patients (pts) with hormone-receptor positive (HR+) metastatic breast cancer (MBC)

1019

Background: Elevated baseline sECD (BsECD) correlates weakly with HER2 overexpression (HER2+). HR+ MBC. Lapatinib benefit was reported in pts with HER2+ tumors irrespective of BsECD status; BsECD status did not predict benefit for HER2- negative (HER2-ve) tumors. sECD levels and their predictive and prognostic value for progression-free survival (PFS) were further examined in a randomized, phase III trial of letrozole ± lapatinib. Methods: Pts (n=1286) with HR+ MBC were randomized to letrozole with placebo (P) or lapatinib (L). HER2 status was evaluated by FISH or IHC in archived tissue. sECD was measured by ELISA at baseline (n=1102 available samples), and every 4 wk. Pts were considered sECD+ if serum sECD was >15 ng/ml. Results: BsECD was positive in 14% (125/894) and 42% (87/208) of pts with HER2-ve and HER2+ tumors, respectively. Correlation between BsECD and FISH was weak but significant in HER2+ pts (R=0.35, p<0.0001) but not in HER2-ve pts (R=0.03, p=0.362). Unlike for HER2+ tumors, BsECD+ did not predict benefit in PFS from L in pts with HER2-ve tumors. HR: Hazard Ratio In pts with HER2- ve tumors, median ECD levels were stable in the P arm but increased slightly (4 ng/mL) in the L arm. In the HER2+ group, median levels in the P arm declined (3.5 ng/mL) but increased at 4 wk in L arm (3.4 ng/mL) and were stable thereafter. Conversion from sECD-ve to sECD+ was observed in both arms but did not correlate with outcome or provide predictive value. Data related to ECD status conversion will be reported. Conclusions: BsECD+ status correlates with HER2+ tumor status and may predict L benefit but BsECD+ status did not predict benefit in pts with HER2-ve tumors. On therapy changes in median sECD were small. Conversion from BsECD-ve to sECD+ did not predict L benefit and we could not confirm that evaluation of on treatment ECD status may help treatment decision.

[Table: see text]

[Table: see text]

Relationship between total and high molecular weight adiponectin levels and plasma nonesterified fatty acid tolerance during enhanced intravascular triacylglycerol lipolysis in men

CONTEXT

Increased plasma nonesterified fatty acid (NEFA) appearance during enhanced intravascular triacylglycerol (TG) lipolysis is a marker of metabolic adipose tissue dysfunction and may lead to the development of insulin resistance. The relationship between total and high molecular weight (HMW) adiponectin levels, NEFA appearance, and total TG lipolytic capacity has not been previously studied in humans.

OBJECTIVES

Our objective was to determine whether total and HMW adiponectin plasma levels are associated with plasma NEFA level and appearance, and with total TG lipolytic rate during enhanced intravascular TG lipolysis in men.

DESIGN

This was a cross-sectional metabolic study.

SETTING

The study was performed at an academic clinical research center.

PARTICIPANTS

There were 15 healthy men (mean +/- sd body mass index 25.5 +/- 4.7 kg/m(2)) aged 21-50 yr (mean +/- sd 31.1 +/- 10.2) without first-degree relatives with type 2 diabetes included in the study.

INTERVENTIONS

Pancreatic clamps and iv infusion of stable isotopic tracers ([1,1,2,3,3-(2)H(5)]glycerol and [U-(13)C]palmitate) were performed, whereas intravascular TG lipolysis was clamped by iv infusion of heparin plus Intralipid at low (fasting) and high insulin levels. Total and HMW adiponectin levels were measured using an ELISA.

MAIN OUTCOME MEASURES

Levels of total and HMW adiponectin, palmitate appearance (plasma palmitate appearance rate), and glycerol appearance (plasma glycerol appearance rate) were calculated.

RESULTS

During heparin plus Intralipid infusion, total and HMW adiponectin was inversely correlated with plasma palmitate appearance rate (r = -0.65; P = 0.01), but this association was lost when expressed per nonlean weight. Adiponectin levels were positively associated with plasma glycerol appearance rate per nonlean weight (r = 0.71 and r = 0.66, respectively; P < or = 0.01).

CONCLUSIONS

Increased adipose tissue mass likely explains the association between low adiponectin and reduced NEFA tolerance. Adiponectin level is a marker of total TG lipolytic rate per adipose tissue mass in men.

A 6 gene molecular predictor of lapatinib related benefit: from cell line models to clinical trials

Abstract #58

Background: Identification of molecular predictors of response is an important aspect of individualized cancer treatment. Responses to lapatinib (L), an oral inhibitor of HER2 and EGFR, approved in combination with capecitabine for HER2+ metastatic breast cancer (MBC), were evaluated in a panel of BC cell lines. Computational approaches were used to identify transcripts that quantitatively associate with response to L in the cell line panel that were then tested in 2 clinical trials.&#x2028; Methods: The clinical utility of a 6-gene predictor was tested retrospectively using a branched-chain DNA assay in paraffin-embedded archival tumor tissue from patients (pts) with HER2 negative or untested MBC tumors enrolled in a phase III trial of paclitaxel (P) vs. P+L, and from pts with HER2 positive MBC enrolled in a L monotherapy trial. Expression of HER2 transcript using the branched-chain assay was compared with HER2 fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) status; discordant cases were analyzed. Response patterns for pts with HER2+ tumors and a computational model that predicts L sensitivity or resistance is described.&#x2028; Results: Ingenuity analysis of the mRNA predictors of response to L identified in the BC cell line panel revealed saturated gene networks with HER2 as a major node. The 6-gene predictor of response was comprised of 2 genes associated with sensitivity to L: HER2 and GRB7; 4 genes associated with resistance to L: CRK, ACOT9, FLJ31079, and DDX5. Expression results for the 6 genes and progression-free survival (PFS) data were available for 159 pts on L+P. Median PFS in the branched-chain HER2+ group was 32.9 wks vs. 22.4 wks in the HER2-negative group. The 6-gene predictor was used to predict response to L in the HER2+ pts. Comparison of PFS in the 24 “L sensitive” tumors vs. 25 “L resistant” tumors indicated that the predictor, derived from cell-line analyses, had the potential to predict clinical response to L in pts treated with L+P (HR=0.58; 95% CI=0.30-1.11; p=0.07). The 6-gene predictor was further tested in an independent L monotherapy study in pts with HER2 FISH+ MBC. Comparison of PFS in the 24 “L sensitive” tumors vs. 28 “ L resistant” tumors reconfirmed the potential of the 6-gene predictor to enrich for HER2+ pts most likely to experience clinical benefit from L (HR=0.40; 95% CI=0.19-0.84; p=0.015). Further testing is ongoing.&#x2028; Conclusions: This study suggests that molecular predictors of clinical response can be developed through an analysis of response from a collection of 50 BC cell lines. The identification of a L specific 6-gene assay is promising as a clinical predictor of benefit from L in pts with HER2+ BC.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 58.

Efficient parallel synthesis of macrocyclic peptidomimetics

A new method for solid phase parallel synthesis of chemically and conformationally diverse macrocyclic peptidomimetics is reported. A key feature of the method is access to broad chemical and conformational diversity. Synthesis and mechanistic studies on the macrocyclization step are reported.

Province-wide population survey of acute appendicitis in Canada. New twists to an old disease

BACKGROUND

This study, sponsored and conducted by Le Collège des Médecins du Québec, audited the management of acute appendicitis in the Province of Québec (Population 7.6 million), Canada, over a period of 1 year (April 2002-March 2003).

METHODS

A questionnaire was sent to the Health Records Department of all hospitals surgically treating appendicitis in the province. Data from 85 (100%) hospitals were received and reviewed.

RESULTS

During the study period, 7,599 appendectomies were performed, and 5,707 (75%) were selected for study (55% men). The rate of normal and perforated appendix was 5.4% and 15.9% respectively. Median hospital stay for simple and perforated appendicitis was 2.6 and 5.8 days, respectively. At least one imaging procedure was done in 86% of cases (23% computed tomography [CT], 55% ultrasound). Antibiotics were not given in 7% of cases and in 8% of patients with a perforation. Seventeen percent of patients did not receive preoperative or intraoperative doses, and postoperatively, 69% of patients received unnecessary doses. Laparoscopy was used in 35% of cases and was associated with a reduction in postoperative stay for simple (2.6 versus 2.9 days, p < 0.001) and perforated appendicitis (4.6 versus 5.9 days, p = 0.004). A low rate of laparoscopy (<25%) was found in 53% of teaching (University and Affiliated) and 45% of nonteaching institutions. Conversion to open surgery was necessary in 9.7% of simple appendicitis and 29.3% of perforated ones (p < 0.001).

CONCLUSIONS

Although results of this survey are comparable to those of similar published series, a few concerns emerge. Many have to do with patient noncompliance with recommended antibiotic usage for acute appendicitis. Further, although laparoscopy seems to be slowly making its way into the surgical armamentarium, the low rate of laparoscopic appendectomies in teaching hospitals raises the issue of appropriate resident training.

Initial development of an integrated optoelectronic probe for biomedical imaging

There has recently been increased interest and progress in the development of medical diagnostic techniques based on the optical properties of tissues (e.g. optical absorption and scattering at different wavelengths) and various substances of interest (e.g. fluorescence of intra-cellular structures, drugs, or dyes). Many applications could be envisaged for an optical probe or imaging system that is both inexpensive and small enough to be portable or even implantable. However, current systems do not meet these two criteria, as they are generally constructed using discrete components. We present an integrated circuit implementation of an optical probe, where a detector and receiver circuit are fabricated together on a single chip in a standard analog CMOS process. The advantages of an integrated probe, as opposed to a more conventional optical fiber-based approach, include improvements in light collection efficiency, signal to noise ratio, size, and cost.

Assessment in the context of uncertainty: how many members are needed on the panel of reference of a script concordance test?

PURPOSE

The script concordance test (SCT) assesses clinical reasoning in the context of uncertainty. Because there is no single correct answer, scoring is based on a comparison of answers provided by examinees with those provided by members of a panel of reference made up of experienced practitioners. This study aims to determine how many members are needed on the panel to obtain reliable scores to compare against the scores of examinees.

METHODS

A group of 80 residents were tested on 73 items (Cronbach's alpha: 0.76). A total of 38 family doctors made up the pool of experienced practitioners, from which 1000 random panels of reference of increasing sizes (5, 10, 15, 20, 25 and 30) were generated with a resampling procedure. Residents' scores were computed for each panel sample. Units of analysis were means of residents' score, test reliability coefficient and correlation coefficient between scores obtained with a given panel of reference versus the scores obtained with the full panel of 38. Statistics were averaged across the 1000 samples for each panel size for the mean and test reliability computations, and across 100 samples for the correlation computation.

RESULTS

For sample variability, there was a 3-fold increase in standard deviation of means between a sample panel size of 5 (SD=1.57) and a panel size of 30 (SD=0.50). For reliability, there was a large difference in precision between a panel size of 5 (0.62) and a panel size of 10 (0.70). When the panel size was over 20, the gain became negligible (0.74 for 20 and 0.76 for 38). For correlation, the mean correlation coefficient values were 0.90 with 5 panel members, 0.95 with 10 members and 0.98 with 20 members.

CONCLUSION

Any number over 10 is associated with acceptable reliability and good correlation between the samples versus the full panel of 38. For high stake examinations, using a panel of 20 members is recommended. Recruiting more than 20 panel members shows only a marginal benefit in terms of psychometric properties.