Liver function and portal-systemic shunting quantified by the oral cholate challenge test and risk for large oesophageal varices

BACKGROUND

The quantitative HepQuant SHUNT test of liver function and physiology generates a disease severity index (DSI) that correlates with risk for clinical complications, such as large oesophageal varices (LEVs). A derivative test, HepQuant DuO, generates an equivalent DSI and simplifies testing by requiring only oral administration of the test solution and two blood samples at 20 and 60 min.

AIMS

Since the DSIs measured from DuO and SHUNT are equivalent, we compared the diagnostic performance for large oesophageal varices (LEVs) between the DSIs measured from DuO and SHUNT tests.

METHODS

This study combined the data from two prospectively conducted US studies: HALT-C and SHUNT-V. A total of 455 subjects underwent both the SHUNT test and esophagogastroduodenoscopy (EGD).

RESULTS

DSI scores correlated with the probability of LEVs (p < 0.001) and demonstrated a stepwise increase from healthy lean controls without liver disease to subjects with chronic liver disease and no, small or large varices. Furthermore, a cutoff of DSI ≤ 18.3 from DuO had a sensitivity of 0.98 (missing only one case) and, if applied to the endoscopy (EGD) decision, would have prevented 188 EGDs (41.3%). The AUROC for DSI from DuO did not differ from that of the reference SHUNT test method (0.82 versus 0.81, p = 0.3500).

CONCLUSIONS

DSI from HepQuant DuO links liver function and physiology to the risk of LEVs across a wide spectrum of patient characteristics, disease aetiologies and liver disease severity. DuO is minimally invasive, easy to administer, quantitative and may aid the decision to avoid or perform EGD for LEVs.

Within-individual reproducibility of a dual sample oral cholate challenge test (DuO) and simplified versions of the HepQuant SHUNT test

Current noninvasive liver tests measure fibrosis, inflammation, or steatosis and do not measure function. The HepQuant platform of noninvasive tests uniquely assesses both liver function and physiology through the hepatic uptake of stable isotopes of cholate. However, the prototypical HepQuant SHUNT test (SHUNT V1.0) is cumbersome to administer, requiring intravenous and oral administration of cholate and six peripheral venous blood samples over 90 min. To alleviate the burden of test administration, we explored whether an oral only (DuO) version, and other simplified versions, of the test could provide reproducible measurements of liver function. DuO requires only oral dosing and two blood samples over 60 min. The simplified SHUNT test versions were SHUNT V1.1 (oral and IV dosing but four blood samples) and SHUNT V2.0 (oral and IV dosing but only two blood samples over 60 min). In this paper, we describe the reproducibility of DuO and the simplified SHUNT tests relative to that of SHUNT V1.0; equivalency is described in a separate paper. Data from two studies comprising 236 SHUNT tests in 94 subjects were analyzed retrospectively by each method. All simplified methods were highly reproducible across test parameters with intraclass correlation coefficients >0.93 for test parameters Disease Severity Index (DSI) and Hepatic Reserve. DuO and SHUNT V2.0 improved reproducibility in measuring portal-systemic shunting (SHUNT%). These simplified tests, particularly DuO and SHUNT V2.0, are easier to administer and less invasive, thus, having the potential to be more widely accepted by care providers administering the test and by patients receiving the test.

Advances in noninvasive measurement of liver function and physiology: The HepQuant DuO test

Current noninvasive liver tests are surrogates for fibrosis and lack ability to directly measure liver function. HepQuant tests measure liver function and physiology through hepatic uptake of stable cholate isotopes. HepQuant SHUNT (V1.0) involves oral and intravenous dosing and six blood samples over 90 min. We developed simplified test versions: SHUNT V2.0 (oral and intravenous dosing, two blood samples over 60 min) and DuO (oral dosing only, two blood samples over 60 min). The aim of this study was to evaluate equivalency of the simplified tests to the original SHUNT test. Data from three studies comprising 930 SHUNT tests were retrospectively analysed by each method. Equivalence was evaluated in terms of proportion of tests in which the difference between methods was less than any clinically meaningful difference and additionally by two one-sided t-test and bioequivalence methods. DuO and SHUNT V2.0 were equivalent to the original SHUNT test for Disease Severity Index, with >99% and >96% of tests falling within equivalence bounds. DuO and SHUNT V2.0 met equivalency criteria by two one-sided t-tests and bioequivalence. DuO and SHUNT V2.0 are easier to administer, are less invasive than the original SHUNT test and have potential to be more accepted by patients and providers.

Repeat Ivermectin Mass Drug Administrations for Malaria Control II: Protocol for a Double-blind, Cluster-Randomized, Placebo-Controlled Trial for the Integrated Control of Malaria

BACKGROUND

The gains made against malaria have stagnated since 2015, threatened further by increasing resistance to insecticides and antimalarials. Improvement in malaria control necessitates a multipronged strategy, which includes the development of novel tools. One such tool is mass drug administration (MDA) with endectocides, primarily ivermectin, which has shown promise in reducing malaria transmission through lethal and sublethal impacts on the mosquito vector.

OBJECTIVE

The primary objective of the study is to assess the impact of repeated ivermectin MDA on malaria incidence in children aged ≤10 years.

METHODS

Repeat Ivermectin MDA for Malaria Control II is a double-blind, placebo-controlled, cluster-randomized, and parallel-group trial conducted in a setting with intense seasonal malaria transmission in Southwest Burkina Faso. The study included 14 discrete villages: 7 (50%) randomized to receive standard measures (seasonal malaria chemoprevention [SMC] and bed net use for children aged 3 to 59 months) and placebo, and 7 (50%) randomized to receive standard measures and monthly ivermectin MDA at 300 μg/kg for 3 consecutive days, provided under supervision to all eligible village inhabitants, over 2 successive rainy seasons. Nonpregnant individuals >90 cm in height were eligible for ivermectin MDA, and cotreatment with ivermectin and SMC was not permitted. The primary outcome is malaria incidence in children aged ≤10 years, as assessed by active case surveillance. The secondary safety outcome of repeated ivermectin MDA was assessed through active and passive adverse event monitoring.

RESULTS

The trial intervention was conducted from July to November in 2019 and 2020, with additional sampling of humans and mosquitoes occurring through February 2022 to assess postintervention changes in transmission patterns. Additional human and entomological assessments were performed over the 2 years in a subset of households from 6 cross-sectional villages. A subset of individuals underwent additional sampling in 2020 to characterize ivermectin pharmacokinetics and pharmacodynamics. Analysis and unblinding will commence once the database has been completed, cleaned, and locked.

CONCLUSIONS

Our trial represents the first study to directly assess the impact of a novel approach for malaria control, ivermectin MDA as a mosquitocidal agent, layered into existing standard-of-care interventions. The study was designed to leverage the current SMC deployment infrastructure and will provide evidence regarding the additional benefit of ivermectin MDA in reducing malaria incidence in children.

TRIAL REGISTRATIONS

ClinicalTrials.gov NCT03967054; https://clinicaltrials.gov/ct2/show/NCT03967054 and Pan African Clinical Trials Registry PACT201907479787308; https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=8219.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/41197.

Design and analysis of a 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria: Small sample considerations for cluster-randomized trials with count data

BACKGROUND

Cluster-randomized trials allow for the evaluation of a community-level or group-/cluster-level intervention. For studies that require a cluster-randomized trial design to evaluate cluster-level interventions aimed at controlling vector-borne diseases, it may be difficult to assess a large number of clusters while performing the additional work needed to monitor participants, vectors, and environmental factors associated with the disease. One such example of a cluster-randomized trial with few clusters was the "efficacy and risk of harms of repeated ivermectin mass drug administrations for control of malaria" trial. Although previous work has provided recommendations for analyzing trials like repeated ivermectin mass drug administrations for control of malaria, additional evaluation of the multiple approaches for analysis is needed for study designs with count outcomes.

METHODS

Using a simulation study, we applied three analysis frameworks to three cluster-randomized trial designs (single-year, 2-year parallel, and 2-year crossover) in the context of a 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria. Mixed-effects models, generalized estimating equations, and cluster-level analyses were evaluated. Additional 2-year parallel designs with different numbers of clusters and different cluster correlations were also explored.

RESULTS

Mixed-effects models with a small sample correction and unweighted cluster-level summaries yielded both high power and control of the Type I error rate. Generalized estimating equation approaches that utilized small sample corrections controlled the Type I error rate but did not confer greater power when compared to a mixed model approach with small sample correction. The crossover design generally yielded higher power relative to the parallel equivalent. Differences in power between analysis methods became less pronounced as the number of clusters increased. The strength of within-cluster correlation impacted the relative differences in power.

CONCLUSION

Regardless of study design, cluster-level analyses as well as individual-level analyses like mixed-effects models or generalized estimating equations with small sample size corrections can both provide reliable results in small cluster settings. For 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria, we recommend a mixed-effects model with a pseudo-likelihood approximation method and Kenward-Roger correction. Similarly designed studies with small sample sizes and count outcomes should consider adjustments for small sample sizes when using a mixed-effects model or generalized estimating equation for analysis. Although the 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria is already underway as a parallel trial, applying the simulation parameters to a crossover design yielded improved power, suggesting that crossover designs may be valuable in settings where the number of available clusters is limited. Finally, the sensitivity of the analysis approach to the strength of within-cluster correlation should be carefully considered when selecting the primary analysis for a cluster-randomized trial.

Ultrasonic Bone Scalpel (USBS) Does Not Reduce Blood Loss During Posterior Spinal Fusion (PSF) in Patients with Adolescent Idiopathic Scoliosis (AIS): Randomized Clinical Trial

STUDY DESIGN

Randomized Clinical Trial.

OBJECTIVE

The aim of this study was to compare the efficacy of USBS with standard-of-care surgical instruments during posterior spinal fusion (PSF) in patients with adolescent idiopathic scoliosis (AIS) by evaluating the difference in estimated blood loss per level fused (EBL/level).

SUMMARY OF BACKGROUND DATA

PSF surgery for AIS is often associated with high blood loss. Use of an ultrasonic bone scalpel (USBS) has been proposed to reduce blood loss during scoliosis surgery.

METHODS

This was a single-blinded (patient-blinded), randomized, controlled superiority trial. We randomized 66 patients with AIS undergoing PSF to the control group (osteotome) or the experimental group (USBS). The primary outcome was intraoperative EBL/level obtained from red blood cell salvage reports. One-year follow-up was available for 57 of 62 (92%) of patients.

RESULTS

EBL/level averaged 35 and 39 mL/level in the experimental and control groups, respectively [adjusted mean difference USBS - osteotome -8 mL/level, 95% CI: -16.4 to 0.3 mL/level, P = 0.0575]. There was no difference in curve correction [adjusted mean difference: -1.7%, 95% CI: -7.0 to 3.6%, P = 0.5321] or operative time [adjusted mean difference: -3.55 minutes, 95% CI: -22.45 to 15.46 min, P = 0.7089] between groups. Complications requiring change in routine postoperative care were noted in eight patients: two occurred in patients assigned to the experimental group and six occurred in patients assigned to the control group.

CONCLUSION

There was no clinically significant difference in total blood loss, EBL/level, or complications between the two groups. In contrast to reports from other centers, at our high-volume spine center, USBS did not lead to reduced blood loss during PSF for AIS. These results may not be generalizable to centers with longer baseline operative times or higher baseline average blood loss during PSF for AIS.Level of Evidence: 1.

The within-individual reproducibility of the disease severity index from the HepQuant SHUNT test of liver function and physiology

The HepQuant SHUNT test quantifies liver function and blood flow using systemic and portal clearances of cholate. The test can identify the risk of well-compensated patients to develop complications of cirrhosis. To confirm the reliability of a single HepQuant SHUNT test we defined its within-individual reproducibility. Healthy subjects (n = 16), 16 with nonalcoholic steatohepatitis (NASH), and 16 with chronic hepatitis C virus (HCV) underwent 3 HepQuant SHUNT tests on 3 separate days within 30 days. The test involves simultaneous administration of 20 mg 13C-cholate IV and 40 mg d4-cholate PO, and subsequent collection of 3 mL blood samples at 5, 20, 45, 60, and 90 minutes. Clearances are expressed as systemic and portal hepatic filtration rate. Portal-systemic shunting (SHUNT), a disease severity index (DSI), and an estimate of DSI (STAT) are calculated from the clearances. Reproducibility was determined by the intraclass correlation coefficient (ICC > 0.70) and Bland-Altman analysis. Equal numbers of NASH and HCV patients had either early (F0-F2) or advanced (F3/F4) stages of fibrosis. All F3/F4 subjects were clinically compensated. The intraclass correlation coefficient (ICC) for DSI was 0.94 (0.90-0.96 95% confidence interval) indicating excellent reproducibility. The other test parameters had ICCs ranging from 0.74 (SHUNT) to 0.90 (STAT). In Bland-Altman analysis, the mean of differences between measurements of DSI was 0.13 with standard deviation 2.12. The excellent reproducibility of the HepQuant SHUNT test, particularly DSI, supports the use this minimally invasive, blood-based test as a reliable test of liver function and physiology.

Dalcetrapib Reduces Risk of New-Onset Diabetes in Patients With Coronary Heart Disease

OBJECTIVE

Incident type 2 diabetes is common among patients with recent acute coronary syndrome and is associated with an adverse prognosis. Some data suggest that cholesteryl ester transfer protein (CETP) inhibitors reduce incident type 2 diabetes. We compared the effect of treatment with the CETP inhibitor dalcetrapib or placebo on incident diabetes in patients with recent acute coronary syndrome.

RESEARCH DESIGN AND METHODS

In the dal-OUTCOMES trial, 15,871 patients were randomly assigned to treatment with dalcetrapib 600 mg daily or placebo, beginning 4-12 weeks after an acute coronary syndrome. Absence of diabetes at baseline was based on medical history, no use of antihyperglycemic medication, and hemoglobin A_1c and serum glucose levels below diagnostic thresholds. Among these patients, incident diabetes after randomization was defined by any diabetes-related adverse event, new use of antihyperglycemic medication, hemoglobin A_1c ≥6.5%, or a combination of at least two measurements of serum glucose ≥7.0 mmol/L (fasting) or ≥11.1 mmol/L (random).

RESULTS

At baseline, 10,645 patients (67% of the trial cohort) did not have diabetes. During a median follow-up of 30 months, incident diabetes was identified in 403 of 5,326 patients (7.6%) assigned to dalcetrapib and in 516 of 5,319 (9.7%) assigned to placebo, corresponding to absolute risk reduction of 2.1%, hazard ratio of 0.77 (95% CI 0.68-0.88; P < 0.001), and a need to treat 40 patients for 3 years to prevent 1 incident case of diabetes. Considering only those with prediabetes at baseline, the number needed to treat for 3 years to prevent 1 incident case of diabetes was 25. Dalcetrapib also decreased the number of patients who progressed from normoglycemia to prediabetes and increased the number who regressed from diabetes to no diabetes.

CONCLUSIONS

In patients with a recent acute coronary syndrome, incident diabetes is common and is reduced substantially by treatment with dalcetrapib.

Does disability level impact the relationship of muscle strength to walking performance in people with multiple sclerosis? a cross-sectional analysis

BACKGROUND AND PURPOSE

Strength training can improve muscle weakness in people with multiple sclerosis (MS), but does not consistently improve walking. Disability level may impact the relationship of muscle weakness and walking performance in people with MS, but few studies have investigated the impact of disability on the relationship of strength and walking. The purpose of this study was to compare the relationships of strength in lower body and trunk muscles to walking performance between mild and moderate disability groups in people with MS.

METHODS

Data from 36 participants with MS who had mild disability (Expanded Disability Status Scale - EDSS 0 to 3.5) and 36 participants who had moderate disability (EDSS 4.0 to 5.5) were analyzed. Hand-held dynamometry measured strength in eight muscle groups from the ankle, knee, hip, and trunk. Timed 25-Foot Walk (T25FW) and 6-Minute Walk Test (6MWT) measured walking speed and endurance, respectively. Pearson correlations and beta coefficients (ß) were reported for each bivariate relationship of muscle strength to T25FW and 6MWT from both mild and moderate disability groups. Linear regression was then used to compare differences in beta coefficients (Δß) between disability groups for the relationship of each muscle variable to T25FW and 6MWT. A positive Δß indicated a stronger relationship of strength to walking performance in the mild disability group, while a negative Δß favored the moderate disability group.

RESULTS

Overall, there were stronger Pearson correlations between muscle strength variables to T25FW and 6MWT in the mild (r = 0.57 to 0.77) compared to moderate disability group (r = 0.10 to 0.54). The mild disability group had significantly greater beta coefficients for T25FW with ankle dorsiflexion (Δß = 0.67, 95%CI: 0.27-1.07), knee extension (Δß = 0.68, 95%CI: 0.28-1.08), and hip abduction (Δß = 0.77, 95%CI: 0.01-1.52); and for 6MWT with knee extension (Δß = 0.47, 95%CI: 0.06 to 0.88).

DISCUSSION AND CONCLUSION

For people with MS, muscle strength in the lower extremity and trunk may be a more important contributor to T25FW in mild versus moderate disability, but not for 6MWT. While more studies are needed, these results may help to inform rehabilitation intervention when prioritizing strength training to improve walking.

Association of high-density lipoprotein particle concentration with cardiovascular risk following acute coronary syndrome: A case-cohort analysis of the dal-Outcomes trial

BACKGROUND

High-density lipoprotein cholesterol (HDL-C) concentration is inversely related to risk of major adverse cardiovascular events (MACE) in epidemiologic studies but is a poorer predictor of MACE in patients with established coronary heart disease. HDL particle concentration (HDLP) has been proposed as a better predictor of risk. We investigated whether HDLP is associated with risk of MACE after acute coronary syndrome (ACS).

METHODS

The dal-Outcomes trial compared the CETP inhibitor dalcetrapib with placebo in patients with recent ACS. In a nested case-cohort analysis, total, large, medium, and small HDLPs were measured by nuclear magnetic resonance spectroscopy at baseline (4-12 weeks after ACS) in 476 cases with MACE and 902 controls. Hazard ratios (HRs; case-control) for 1-SD increment of HDLP or HDL-C at baseline were calculated with and without adjustment for demographic, clinical, laboratory, and treatment variables. Similarly, HRs for MACE were calculated for changes in HDLP or HDL-C from baseline to month 3 of assigned treatment.

RESULTS

Over median follow-up of 28 months, the risk of MACE was not associated with baseline HDLP (adjusted HR = 0.98, 95% CI = 0.84-1.15, P = .81), any HDLP subclass, or HDL-C. Dalcetrapib increased HDL-C and total, medium, and large HDLP and decreased small HDLP but had no effect on MACE compared with placebo. There were no association of risk of MACE with change in HDLP or HDL-C and no interaction with assigned study treatment.

CONCLUSIONS

Neither baseline HDLP nor the change in HDLP on treatment with dalcetrapib or placebo was associated with risk of MACE after ACS.

P6193Dalcetrapib reduces incident diabetes in patients with recent acute coronary syndrome

Background

Among patients with acute coronary syndrome (ACS) who do not have diabetes, incident diabetes is common and associated with an adverse prognosis. Some data suggest that high density lipoprotein (HDL) has favourable effects on beta cell function and that cholesteryl ester transfer protein (CETP) inhibitors reduce incident type 2 diabetes in conjunction with increased HDL cholesterol (HDL-C) concentration. Dalcetrapib is a CETP inhibitor under ongoing evaluation as a potential cardiovascular therapy.

Purpose

We compared the effect of treatment with dalcetrapib or placebo on incident diabetes in patients with recent acute coronary syndrome (ACS).

Methods

In the dal-OUTCOMES trial, 15,871 patients were randomly assigned to treatment with dalcetrapib 600 mg or placebo daily, beginning 4–12 weeks after ACS. Absence of diabetes at baseline was based upon medical history, no use of diabetes medication, haemoglobin A1c <6.5%, and plasma glucose level <7 mmol/L (if measured under fasting conditions) or <11.1 mmol/L (if measured under non-fasting conditions). Among these patients, incident diabetes after randomization was defined by any diabetes-related adverse event, use of a diabetes medication, HbA1c ≥6.5%, or two measurements of plasma glucose ≥7 mmol/L (fasting) or ≥11.1 mmol/L (non-fasting). The association of incident diabetes with baseline and on-treatment HDL-C was determined.

Results

At baseline, 10621 patients (67% of the trial cohort) did not have diabetes and formed the analysis cohort. Over median follow-up of 31 months, incident diabetes was identified in 392 of 5314 patients (7.4%) assigned to dalcetrapib and 505 of 5307 (9.5%) assigned to placebo (odds ratio [OR] 0.76; 95% confidence interval [CI] 0.66–0.87; P<0.001). This corresponds to an absolute reduction in incident diabetes of 2.1%, and a need to treat 47 patients (for 31 months) to prevent 1 case of diabetes. Kaplan-Meier estimates of the cumulative incidence of diabetes are shown in the Figure. Across both treatment groups, incident diabetes was inversely associated with baseline HDL-C (OR 0.98 for 1 mg/dL increase in baseline HDL-C; 95% CI 0.97–0.98, P<0.001). In the dalcetrapib group, there was a further inverse association of incident diabetes with the change in HDL-C on assigned treatment (OR 0.98 for 1 mg/dL increase in HDL-C from baseline; 95% CI 0.97–0.99, P=0.002). Dalcetrapib was safe and generally well-tolerated in the trial.

Conclusions

In patients with recent ACS who do not have diabetes at baseline, incident diabetes is common. Dalcetrapib treatment reduced the relative risk of incident diabetes by 24% and the absolute risk by 2.1% over a median of 31 months. The reduction in incident diabetes with dalcetrapib was associated with increased HDL-C on treatment.

Acknowledgement/Funding

The dal-OUTCOMES trial was funded by F. Hoffmann LaRoche

Association of Lipoprotein(a) With Risk of Recurrent Ischemic Events Following Acute Coronary Syndrome: Analysis of the dal-Outcomes Randomized Clinical Trial

Importance

It is uncertain whether lipoprotein(a) [Lp(a)], which is associated with incident cardiovascular disease, is an independent risk factor for recurrent cardiovascular events after acute coronary syndrome (ACS).

Objective

To determine the association of Lp(a) concentration measured after ACS with the subsequent risk of ischemic cardiovascular events.

Design, Setting, and Participants

This nested case-cohort analysis was performed as an ad hoc analysis of the dal-Outcomes randomized clinical trial. This trial compared dalcetrapib, the cholesteryl ester transfer protein inhibitor, with placebo in patients with recent ACS and was performed between April 2008 and September 2012 at 935 sites in 27 countries. There were 969 case patients who experienced a primary cardiovascular outcome, and there were 3170 control patients who were event free at the time of a case event and had the same type of index ACS (unstable angina or myocardial infarction) as that of the respective case patients. Concentration of Lp(a) was measured by immunoturbidimetric assay. Data analysis for this present study was conducted from June 8, 2016, to April 21, 2017.

Interventions

Patients were randomly assigned to receive treatment with dalcetrapib, 600 mg daily, or matching placebo, beginning 4 to 12 weeks after ACS.

Main Outcomes and Measures

Death due to coronary heart disease, a major nonfatal coronary event (myocardial infarction, hospitalization for unstable angina, or resuscitated cardiac arrest), or fatal or nonfatal ischemic stroke.

Results

The mean (SD) age was 63 (10) years for the 969 case patients and 60 (9) years for the 3170 control patients, and both cohorts were composed of predominantly male (770 case patients [79%] and 2558 control patients [81%]; P = .40) and white patients (858 case patients [89%] and 2825 control patients [89%]; P = .62). At baseline, the median (interquartile range) Lp(a) level was 12.3 (4.7-50.9) mg/dL. There was broad application of evidence-based secondary prevention strategies after ACS, including use of statins in 4030 patients (97%). The cumulative distribution of baseline Lp(a) levels did not differ between cases and controls at P = .16. Case-cohort regression analysis showed no association of baseline Lp(a) level with risk of cardiovascular events. For a doubling of Lp(a) concentration, the hazard ratio (case to control) was 1.01 (95% CI, 0.96-1.06; P = .66) after adjustment for 16 baseline variables, including assigned study treatment.

Conclusions and Relevance

For patients with recent ACS who are treated with statins, Lp(a) concentration was not associated with adverse cardiovascular outcomes. These findings call into question whether treatment specifically targeted to reduce Lp(a) levels would thereby lower the risk for ischemic cardiovascular events after ACS.

Trial Registration

clinicaltrials.gov Identifier: NCT00658515.

Effective B cell activation in vitro during viremic HIV-1 infection with surrogate T cell stimulation

Identifying HIV-1-associated B cell defects and responses to activation may direct interventions to circumvent their impaired antibody responses to infection and vaccines. Among 34 viremic HIV-1-infected and 20 seronegative control adults, we measured baseline frequencies and activation of B and T cell subsets, expression of activation-induced cytidine deaminase (AID), potential determinants of B cell activation in vivo and B and T cell responses in vitro. At baseline, HIV-1 infection was associated with increased IgM memory and decreased anergic cell frequencies, as well as increased activation in all 10 B cell subsets compared with controls. HIV-1 status, TFH activation, and BAFF were significant potential drivers of B cell activation. Despite high baseline activation among HIV-1-infected subjects, stimulation in vitro with combined surrogates for antigen (anti-IgM), cognate (CD40 ligand) and soluble T cell factors (IL-4) elicited comparable B cell activation, transitions from naïve to class-switched memory cells and AID expression in both groups. In summary, viremic HIV-1 infection perturbs circulating B cell subsets and activation at each stage of B cell maturation. However, that appropriate stimulation of B cells elicits effective activation and maturation provides impetus for advancing vaccine development to prevent secondary infections by circumventing early B cell defects.

Contributions of Ankle, Knee, Hip, and Trunk Muscle Function to Gait Performance in People With Multiple Sclerosis: A Cross-Sectional Analysis

BACKGROUND

The relative importance of lower extremity and trunk muscle function to gait in people with multiple sclerosis (MS) is unknown.

OBJECTIVE

This study aimed to investigate the association of lower extremity and trunk muscle function with gait performance in people who have MS and mild-to-moderate disability.

DESIGN

This was a cross-sectional, observational study.

METHODS

Participants were people who had an Expanded Disability Status Scale score of ≤ 5.5. Eleven lower extremity and trunk muscles were assessed using handheld dynamometry or endurance tests. Gait performance was assessed with the Timed 25-Foot (7.62 m) Walk (T25FW) and 6-Minute Walk Test (6MWT). Regression analysis was used to quantify the association between gait outcomes and muscle variables.

RESULTS

Seventy-two participants with MS and a mean Expanded Disability Status Scale score of 3.5 (SD = 1.14) were enrolled. Adjusted for age and sex, the multivariate model including hip abduction, ankle plantar flexion, trunk flexion, and knee flexion explained 57% of the adjusted variance in the T25FW; hip abduction, ankle plantar flexion, and trunk flexion explained 61% of the adjusted variance in the 6MWT. The strongest predictors were ankle plantar flexion endurance for the T25FW and hip abduction strength for the 6MWT: a 1-SD increase in ankle plantar flexion (15.2 heel-raise repetitions) was associated with a 0.33-second reduction in the T25WT (95% CI = - 0.71 to - 0.14 seconds); a 1-SD increase in normalized hip abduction strength (0.14 kg/body mass index) was associated with a 54.4-m increase in the 6MWT (28.99 to 79.81 m).

LIMITATIONS

Different measurement scales for independent variables were included because the muscle function assessment used either force or endurance.

CONCLUSIONS

For the major muscles in the lower extremity and trunk, hip abduction, ankle plantar flexion, trunk flexion, and knee flexion were the strongest predictors of gait performance.

Aldosterone Does Not Predict Cardiovascular Events Following Acute Coronary Syndrome in Patients Initially Without Heart Failure

Background

Aldosterone may have adverse effects in the myocardium and vasculature. Treatment with an aldosterone antagonist reduces cardiovascular risk in patients with acute myocardial infarction complicated by heart failure (HF) and left ventricular systolic dysfunction. However, most patients with acute coronary syndrome do not have advanced HF. Among such patients, it is unknown whether aldosterone predicts cardiovascular risk.

Methods and Results

To address this question, we examined data from the dal‐OUTCOMES trial that compared the cholesteryl ester transfer protein inhibitor dalcetrapib with placebo, beginning 4 to 12 weeks after an index acute coronary syndrome. Patients with New York Heart Association class II (with LVEF <40%), III, or IV HF were excluded. Aldosterone was measured at randomization in 4073 patients. The primary outcome was a composite of coronary heart disease death, nonfatal myocardial infarction, stroke, hospitalization for unstable angina, or resuscitated cardiac arrest. Hospitalization for HF was a secondary endpoint. Over a median follow‐up of 37 months, the primary outcome occurred in 366 patients (9.0%), and hospitalization for HF occurred in 72 patients (1.8%). There was no association between aldosterone and either the time to first occurrence of a primary outcome (hazard ratio for doubling of aldosterone 0.92, 95% confidence interval 0.78‐1.09, P=0.34) or hospitalization for HF (hazard ratio 1.38, 95% CI 0.96‐1.99, P=0.08) in Cox regression models adjusted for covariates.

Conclusions

In patients with recent acute coronary syndrome but without advanced HF, aldosterone does not predict major cardiovascular events.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00658515.

Effects of pioglitazone or exercise in older adults with mild cognitive impairment and insulin resistance: a pilot study

AIMS

To examine the effects of pioglitazone or endurance exercise training on cognitive function in older adults with mild cognitive impairment (MCI) and insulin resistance.

METHODS

Seventy-eight adults (mean age ± SD: 65 ± 7 years) with central obesity and MCI were randomized to 6 months of endurance exercise, pioglitazone or control.

RESULTS

Sixty-six participants completed the study. Exercise training did not significantly increase peak oxygen uptake compared to control (p = 0.12). Compared to control, insulin resistance improved in the pioglitazone group (p = 0.002) but not in the exercise group (p = 0.25). There was no measureable effect of pioglitazone or exercise on cognitive performance compared to control.

CONCLUSION

In this pilot study, pioglitazone improved insulin resistance but not cognitive performance in older adults with MCI and insulin resistance.

Timing of Ibuprofen Use and Musculoskeletal Adaptations to Exercise Training in Older Adults

Prostaglandins (PGs) increase in bone in response to mechanical loading and stimulate bone formation. Inhibition of cyclooxygenase (COX), the enzyme responsible for PG synthesis, by non-steroidal anti-inflammatory drugs (NSAIDs) impairs the bone formation response to loading in animals when administered before, but not after, loading. The aim was to determine whether the timing of ibuprofen use (400 mg before versus after exercise sessions) is a significant determinant of the adaptive response of BMD to exercise training in older adults. We hypothesized that taking ibuprofen before exercise would attenuate the improvements in total hip and lumbar spine BMD in response to 36 weeks of training when compared with placebo or with ibuprofen use after exercise. Untrained women and men (N = 189) aged 60 to 75 years were randomly assigned to 1 of 3 treatment arms: placebo before and after exercise (PP); ibuprofen before and placebo after exercise (IP); and placebo before and ibuprofen after exercise (PI).

The difference between groups in the change in BMD was not significant when IP was compared with either PP (hip, − 0.5% (− 1.4, 0.4); spine, 0.1% (− 0.9, 1.2)) or PI (hip, 0.3% (− 0.6, 1.2); spine, 0.5% (− 0.5, 1.5)). Ibuprofen use appeared to have more adverse effects on BMD in women than men. The study demonstrated that ibuprofen use did not significantly alter the BMD adaptations to exercise in older adults, but this finding should be interpreted cautiously. It had been expected that the inhibition of bone formation by ibuprofen would be more robust in men than in women, but this did not appear to be the case and may have limited the power to detect the effects of ibuprofen. Further research is needed to understand whether NSAID use counteracts, in part, the beneficial effects of exercise on bone.

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The purpose was to determine whether musculoskeletal adaptations to exercise training in older adults are influenced by NSAID use.

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Ibuprofen use did not significantly alter changes in BMD or fat-free mass, but the study may have been inadequately powered.

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Study attrition was significantly lower in the group that took NSAIDs before exercise suggesting improved tolerance of vigorous bone-loading exercise.

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This was the first randomized, double-blinded placebo- controlled study of ibuprofen effects on BMD from exercise in an older population.

Remote source document verification in two national clinical trials networks: a pilot study

OBJECTIVE

Barriers to executing large-scale randomized controlled trials include costs, complexity, and regulatory requirements. We hypothesized that source document verification (SDV) via remote electronic monitoring is feasible.

METHODS

Five hospitals from two NIH sponsored networks provided remote electronic access to study monitors. We evaluated pre-visit remote SDV compared to traditional on-site SDV using a randomized convenience sample of all study subjects due for a monitoring visit. The number of data values verified and the time to perform remote and on-site SDV was collected.

RESULTS

Thirty-two study subjects were randomized to either remote SDV (N=16) or traditional on-site SDV (N=16). Technical capabilities, remote access policies and regulatory requirements varied widely across sites. In the adult network, only 14 of 2965 data values (0.47%) could not be located remotely. In the traditional on-site SDV arm, 3 of 2608 data values (0.12%) required coordinator help. In the pediatric network, all 198 data values in the remote SDV arm and all 183 data values in the on-site SDV arm were located. Although not statistically significant there was a consistent trend for more time consumed per data value (minutes +/- SD): Adult 0.50 +/- 0.17 min vs. 0.39 +/- 0.10 min (two-tailed t-test p=0.11); Pediatric 0.99 +/- 1.07 min vs. 0.56 +/- 0.61 min (p=0.37) and time per case report form: Adult: 4.60 +/- 1.42 min vs. 3.60 +/- 0.96 min (p=0.10); Pediatric: 11.64 +/- 7.54 min vs. 6.07 +/- 3.18 min (p=0.10) using remote SDV.

CONCLUSIONS

Because each site had different policies, requirements, and technologies, a common approach to assimilating monitors into the access management system could not be implemented. Despite substantial technology differences, more than 99% of data values were successfully monitored remotely. This pilot study demonstrates the feasibility of remote monitoring and the need to develop consistent access policies for remote study monitoring.

Effects of testosterone and progressive resistance exercise in healthy, highly functioning older men with low-normal testosterone levels

CONTEXT

Aging in men is associated with reduced testosterone (T) levels and physiological changes leading to frailty, but the benefits of T supplementation are inconclusive.

OBJECTIVE

We studied the effects of T supplementation with and without progressive resistance training (PRT) on functional performance, strength, and body composition.

DESIGN, SETTING, AND PARTICIPANTS

We recruited 167 generally healthy community-dwelling older men (66 ± 5 years) with low-normal baseline total T levels (200-350 ng/dL).

INTERVENTION

Subjects were randomized to placebo or transdermal T gel [2 doses targeting either a lower (400-550 ng/dL) or higher (600-1000 ng/dL) T range] and to either PRT or no exercise for 12 months.

MAIN OUTCOME MEASURE

The primary outcome was functional performance, whereas secondary outcomes were strength and body composition.

RESULTS

A total of 143 men completed the study. At 12 months, total T was 528 ± 287 ng/dL in subjects receiving any T and 287 ± 65 ng/dL in the placebo group. In the PRT group, function and strength were not different between T- and placebo-treated subjects, despite greater improvements in fat mass (P = .04) and fat-free mass (P = .01) with T. In the non-PRT group, T did not improve function but improved fat mass (P = .005), fat-free mass (P = .03), and upper body strength (P = .03) compared with placebo. There were fewer cardiovascular events in the T-treated groups compared with placebo.

CONCLUSIONS

T supplementation was well tolerated and improved body composition but had no effect on functional performance. T supplementation improved upper body strength only in nonexercisers compared with placebo.

Oral iloprost improves endobronchial dysplasia in former smokers

There are no established chemopreventive agents for lung cancer, the leading cause of cancer death in the United States. Prostacyclin levels are low in lung cancer and supplementation prevents lung cancer in preclinical models. We carried out a multicenter double-blind, randomized, phase II placebo-controlled trial of oral iloprost in current or former smokers with sputum cytologic atypia or endobronchial dysplasia. Bronchoscopy was performed at study entry and after completion of six months of therapy. Within each subject, the results were calculated by using the average score of all biopsies (Avg), the worst biopsy score (Max), and the dysplasia index (DI). Change in Avg was the primary end point, evaluated in all subjects, as well as in current and former smokers. The accrual goal of 152 subjects was reached and 125 completed both bronchoscopies (60/75 iloprost, 65/77 placebo). Treatment groups were well matched for age, tobacco exposure, and baseline histology. Baseline histology was significantly worse for current smokers (Avg 3.0) than former smokers (Avg 2.1). When compared with placebo, former smokers receiving oral iloprost exhibited a significantly greater improvement in Avg (0.41 units better, P = 0.010), in Max (1.10 units better, P = 0.002), and in DI (12.45%, P = 0.006). No histologic improvement occurred in current smokers. Oral iloprost significantly improves endobronchial histology in former smokers and deserves further study to determine if it can prevent the development of lung cancer.

Differential expression of prognostic biomarkers between interval and screen-detected breast cancers: does age or family history matter?

The aim of this study was to compare tumor expression of prognostic biomarkers between interval breast cancers and screen-detected breast cancers overall, and according to age at diagnosis and familial risk. Tissue micro-arrays were constructed from 98 breast cancers (47 interval and 51 screen-detected) diagnosed in women in the Cancer Genetics Network. Arrays were immuno-stained to compare protein expression of six biomarkers including estrogen and progesterone receptor (ER/PR), Her2/neu, EGFR, cytokeratin 5/6, and Ki67. Fisher's Exact test was used to compare expression between interval and screen-detected cancers. Interval cancers were larger (P = 0.04), higher stage (P < 0.001), and more likely to have lobular histology (P = 0.01) than screen-detected cancers. Overall, interval cancers more often overexpressed EGFR (P = 0.01) and were somewhat more likely to be ER- (55% vs. 43%, P = 0.3), and triple negative (ER-/PR-/Her2-) (21 vs. 12%, P = 0.26). A greater difference in the proportion of interval versus screen-detected tumors that were ER- (53 vs. 35%; P = 0.29), PR- (35 vs. 21%; P = 0.25) and EGFR+ (17 vs. 0%; P = 0.02) was evident among women over 50. There was a trend toward differential expression among women with familial risk for PR- (P = 0.005) and triple negative status (P = 0.02). This study provides new data indicating that EGFR may be important in the etiology of interval cancer and be a possible therapeutic target. Our data also suggest that biological differences between interval and screen-detected cancers are more defined in older women. Future studies to confirm this finding and to elucidate novel markers for characterizing interval cancers may be more beneficial to this subgroup.

A randomized phase II chemoprevention trial of 13-CIS retinoic acid with or without alpha tocopherol or observation in subjects at high risk for lung cancer

No chemoprevention strategies have been proven effective for lung cancer. We evaluated the effect of 13-cis retinoic acid (13-cis RA), with or without alpha tocopherol, as a lung cancer chemoprevention agent in a phase II randomized controlled clinical trial of adult subjects at high risk for lung cancer as defined by the presence of sputum atypia, history of smoking, and airflow obstruction, or a prior surgically cured nonsmall cell lung cancer (disease free, >3 years). Subjects were randomly assigned to receive either 13-cis RA, 13-cis RA plus alpha tocopherol (13-cis RA/alpha toco) or observation for 12 months. Outcome measures are derived from histologic evaluation of bronchial biopsy specimens obtained by bronchoscopy at baseline and follow-up. The primary outcome measure is treatment "failure" defined as histologic progression (any increase in the maximum histologic score) or failure to return for follow-up bronchoscopy. Seventy-five subjects were randomized (27/22/26 to observations/13-cis RA/13-cis RA/alpha toco); 59 completed the trial; 55 had both baseline and follow-up bronchoscopy. The risk of treatment failure was 55.6% (15 of 27) and 50% (24 of 48) in the observation and combined (13 cis RA plus 13 cis RA/alpha toco) treatment arms, respectively (odds ratio adjusted for baseline histology, 0.97; 95% confidence interval, 0.36-2.66; P = 0.95). Among subjects with complete histology data, maximum histology score in the observation arm increased by 0.37 units and by 0.03 units in the treated arms (difference adjusted for baseline, -0.18; 95% confidence interval, -1.16 to 0.81; P = 0.72). Similar (nonsignificant) results were observed for treatment effects on endobronchial proliferation as assessed by Ki-67 immunolabeling. Twelve-month treatment with 13-cis RA produced nonsignificant changes in bronchial histology, consistent with results in other trials. Agents advancing to phase III randomized trials should produce greater histologic changes. The addition of alpha tocopherol did not affect toxicity.

Bronchial epithelial Ki-67 index is related to histology, smoking, and gender, but not lung cancer or chronic obstructive pulmonary disease

PURPOSE

To determine whether increased bronchial epithelial proliferation is associated with histology, smoking status, gender, age, chronic obstructive pulmonary disease (COPD), or lung cancer.

EXPERIMENTAL DESIGN

Cross-sectional study of 113 subjects undergoing white light and autofluorescence bronchoscopy: 27 never smokers; 27 current or ex-smokers with normal spirometry; 31 current or ex-smokers with COPD; and 28 current, ex-, or never smokers with lung cancer. Ki-67 expression was determined by immunohistochemistry on all evaluable biopsy sites without carcinoma. Relationships between Ki-67 index (percentage of epithelial cells expressing Ki-67), demographic variables, smoking, histology, and the presence of COPD and/or lung cancer were determined.

RESULTS

Results for both maximal and mean Ki-67 index are similar, so only the former are reported. Average maximal Ki-67 index was higher in current smokers than either ex-smokers or never smokers (48.0% versus 30.6% versus 22.6%; P<0.001). Males had higher Ki-67 index than females (39.9% versus 23.6%; P<0.001). Compared with subjects without disease (Ki-67 index=30.0%), maximal Ki-67 index was not significantly elevated (P=0.44) in subjects with either lung cancer (Ki-67=39.1%) or COPD (Ki-67=38.9%).

CONCLUSIONS

Smoking status, bronchial histology, and gender were significantly associated with Ki-67 index. No increase in Ki-67 index was found in the nonmalignant epithelium of patients with lung cancer or COPD. Although Ki-67 index may provide insight into the short-term effects of chemoprevention agents on cell proliferation, its lack of association with lung cancer or COPD raises question regarding its utility as a lung cancer risk biomarker.

Analysis of c-ErbB1/epidermal growth factor receptor and c-ErbB2/HER-2 expression in bronchial dysplasia: evaluation of potential targets for chemoprevention of lung cancer

PURPOSE

Lung cancer is preceded by a premalignant phase during which intervention could decrease associated morbidity and mortality. Molecular characterization of factors involved in controlling progression of bronchial dysplasias will provide markers of premalignant change and identify targets for chemoprevention.

EXPERIMENTAL DESIGN

Immunohistochemical analysis of epidermal growth factor receptor (EGFR; c-ErbB1/EGFR), HER-2/neu (c-ErbB2/HER-2), Ki-67, and minichromosome maintenance protein 2 (MCM2) expression in bronchial dysplasia was undertaken to characterize molecular alterations associated with the progression of these lesions in 268 bronchoscopically obtained biopsies from 134 subjects.

RESULTS

Analysis of biopsies with the most severe diagnosis from each subject showed a linear relationship between increasing marker expression and severity of dysplastic change for EGFR (P < 0.001), Ki-67 (P < 0.001), and MCM2 (P = 0.001) but not HER-2 (P = 0.102). Increased expression of either EGFR or HER-2 was associated with increased levels of Ki-67 and MCM2 expression, and combined overexpression of these receptors was associated with the highest levels of proliferation, suggesting a synergistic effect. Finally, the lack of an associated trend toward increased EGFR expression when comparing the worst and best biopsies within each subject indicated a potential field effect in the induction of EGFR expression.

CONCLUSIONS

The results suggest a prominent role for EGFR overexpression in the development and progression of bronchial dysplasia and provide rationale for exploring inhibition of EGFR signaling in lung cancer chemoprevention.

Improvement of Postherpetic Neuralgia After Treatment With Intravenous Acyclovir Followed by Oral Valacyclovir

BACKGROUND

Postherpetic neuralgia (PHN) is a complication of shingles (herpes zoster), a painful rash due to varicella-zoster virus reactivation. Studies of patients with PHN and zoster sine herpete (radicular pain without rash) support the notion that low-grade viral ganglionitis contributes to pain. If chronic pain reflects active infection, then antiviral therapy may help patients with PHN.

OBJECTIVE

To determine whether antiviral treatment helps reduce PHN-associated pain.

DESIGN

Prospective, open-label phase I/II clinical trial.

SETTING

Tertiary care university hospital.

PATIENTS

Fifteen patients with moderate to severe PHN.

INTERVENTIONS

Intravenous acyclovir at a dosage of 10 mg/kg every 8 hours for 14 days followed by oral valacyclovir at a dosage of 1000 mg 3 times per day for 1 month.

MAIN OUTCOME MEASURE

Numeric Rating Scale for Pain score.

RESULTS

As defined by a decrease of 2 or more points on the Numeric Rating Scale for Pain, 8 (53%) of 15 patients reported improvement.

CONCLUSION

Clinical improvement reported by most of our patients warrants further investigation in a larger, randomized, double-blind, placebo-controlled trial.

Analysis of c-erb-1 (EGFR) and c-erb-2 (HER2) expression in bronchial dysplasia: Evaluation of potential targets for chemoprevention of lung cancer

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Background: Lung cancer is preceded by a premalignant phase during which intervention could decrease associated morbidity and mortality. Molecular characterization of factors involved in controlling progression of bronchial dysplasia (BD) will provide markers of premalignant change and identify targets for chemoprevention. Methods: Immunohistochemical (IHC) analysis of EGFR, HER2, Ki67 and MCM2 expression in BD was undertaken in 268 bronchoscopically obtained biopsies from 134 consecutive subjects recruited to University of Colorado protocols as study subjects with prior sputum atypia and >20 pack years tobacco use or FEV1 < 75% predicted or as never- or healthy-smoker controls. IHC on the worst and best histologic biopsies from each subject were scored and linear regression tests were used to determine significance of correlation between marker expression and histology or proliferation. Results: Analysis of biopsies with the most severe diagnosis from each subject showed a linear relationship between increasing marker expression and severity of dysplastic change for EGFR (p < 0.001), Ki67 (p < 0.001) and MCM2 (p = 0.001) but not HER2 (p = 0.102). Increased expression of either EGFR or HER2 was associated with increased expression of proliferation markers Ki67and MCM2, and combined overexpression of these receptors was associated with the highest levels of proliferation. Finally, in a comparison of subjects that were grouped according to the degree of difference between their best and worst biopsy histology, the absence of an associated trend toward increased EGFR expression with increased difference in histology suggested a field effect in the induction of EGFR expression. Conclusions: Our results 1) demonstrate a direct correlation between levels of EGFR expression and degree of BD, 2) suggest a field effect in the induction of EGFR expression in the airways of subjects with BD and 3) indicate a potential synergistic effect on epithelial proliferation in lesions with increased expression of both EGFR and HER2. These findings suggest that EGFR plays a prominent role in the development and progression of BD and could provide a promising target for chemoprevention of lung cancer.

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Multi-target interphase fluorescence in situ hybridization assay increases sensitivity of sputum cytology as a predictor of lung cancer

Survival rates for lung cancer are low because patients have disseminated disease at diagnosis; therefore tests for early diagnosis are highly desirable. This pilot study investigated occurrence of chromosomal aneusomy in sputum from a 33 case-control cohort matched on age, gender, and date of sample collection. Subjects had chronic obstructive pulmonary disease and > or = 30 pack-years of tobacco use, and aneusomy was tested using a multi-target DNA FISH assay (LAVysion, Abbott/Vysis). In specimens collected within 12 months of lung cancer diagnosis, abnormality was more frequent among the 18 cases (41%) than the 17 controls (6%; P = 0.04). Aneusomy had no significant association with cytologic atypia, which might indicate that molecular and morphological changes could be independent markers of tumorigenesis. Combining both tests, abnormality was found in 83% of the cases and 20% of the controls (P = 0.0004) suggesting that FISH may improve the sensitivity of cytologic atypia as a predictor of lung cancer.

The predictive value of exhaled nitric oxide measurements in assessing changes in asthma control

Exhaled nitric oxide (eNO) levels are increased in untreated or unstable asthma and measurements can be made easily. Our aim was to assess the usefulness of eNO for diagnosing and predicting loss of control (LOC) in asthma following steroid withdrawal. Comparisons were made against sputum eosinophils and airway hyperresponsiveness (AHR) to hypertonic saline (4.5%). Seventy-eight patients with mild/moderate asthma had their inhaled steroid therapy withdrawn until LOC occurred or for a maximum of 6 wk. Sixty (77.9%) developed LOC. There were highly significant correlations between the changes in eNO and symptoms (p < 0.0001), FEV(1) (p < 0.002), sputum eosinophils (p < 0.0002), and saline PD(15) (p < 0.0002), and there were significant differences between LOC and no LOC groups. Both single measurements and changes of eNO (10 ppb, 15 ppb, or an increase of > 60% over baseline) had positive predictive values that ranged from 80 to 90% for predicting and diagnosing LOC. These values were similar to those obtained using sputum eosinophils and saline PD(15) measurements. We conclude that eNO measurements are as useful as induced sputum analysis and AHR in assessing airway inflammation, with the advantage that they are easy to perform.

Statistical methods to improve the precision of the treadmill exercise test

OBJECTIVES

The study systematically compared different measures of ST segment depression from the treadmill exercise test.

BACKGROUND

The value of the treadmill exercise test for objectively measuring treatment effects is limited by random error in the measurement of ST depression and may be biased by regression to the mean or by the decision to terminate the test.

METHODS

Treadmill exercise was performed in 21 subjects with ischemic heart disease 1 h after isosorbide dinitrate 10 mg or placebo in a double-blind randomized crossover study. A 12-lead electrocardiogram (ECG) was recorded every 30 s during and at peak exercise. The relative sample size needed to detect the nitrate effect was compared for different summary measures of ST depression.

RESULTS

The ST depression measured from a single unmatched lead at longest equivalent sub-maximal exercise needed the lowest sample size to detect the nitrate effect in paired comparisons (p = 0.000006). Averaging over multiple leads or times did not improve detection of the nitrate effect. The rate of increase in ST depression (in mm/min) calculated by linear regression needed a similar sample size (x1.32, 95% CI 0.62 to 2.58). A larger sample size was needed for ST depression at peak exercise (x2.9, CI 1.3, 11.1) and exercise duration (x4.5, CI 1.5, 38). Time to 1-mm ST depression was the least efficient measurement (relative sample size x15.5, CI 1.6, >1,000). Comparison of matched leads resulted in >2-fold differences in estimates of the nitrate effect because of bias from regression to the mean.

CONCLUSIONS

Maximal ST depression at longest equivalent sub-maximal exercise and the maximal rate of increase in ST depression had less bias and random variation than did other commonly used measures. The rate of increase in ST depression is preferred because it can be calculated in either paired or unpaired studies.

Collateral recruitment and "warm-up" after first exercise in ischemic heart disease

BACKGROUND

Proposed mechanisms for "warm-up" after angina on first exercise include ischemic preconditioning and collateral recruitment. The aim of this study was to determine whether patients with ischemic heart disease and well-developed coronary collateral vessels have a greater warm-up response than those with no visible collateral vessels.

METHODS AND RESULTS

Fifteen patients with a total coronary occlusion and collateral vessels and 18 patients with a single coronary artery stenosis and no angiographically visible collateral vessels were studied. Warm-up was measured as the difference in ST depression on the second compared with the first of 2 sequential treadmill exercise tests separated by 10 minutes of rest. There was a trend for the duration of second exercise to increase more in patients with occlusion than in those with stenosis (+1.3 vs +0.54 minutes, respectively, P =.087). In both groups, ST depression was less on second exercise than on first exercise. The size of this decrease was greater in the occlusion group than in the stenosis group. ST depression at equivalent submaximal exercise decreased by 0.52 vs 0.19 mm, respectively (P =.049). The rate of increase in ST depression during exercise decreased by 1.08 versus 0. 55 mm/min, respectively (P =.034). These differences were less after adjustment for ST depression on first exercise (P =.11 and P =.063, respectively).

CONCLUSIONS

The trend for a greater decrease in ST depression on second compared with first exercise in the patients with total coronary occlusion suggests that an increase in collateral flow is a mechanism for warm-up after first exercise in ischemic heart disease.

Relation between duration and intensity of first exercise and "warm up" in ischaemic heart disease

OBJECTIVE

To determine the importance of the duration and intensity of "warm up" exercise for reducing ischaemia during second exercise in patients with exertional angina.

DESIGN

Randomised crossover comparison of three warm up exercise protocols.

PATIENTS

18 subjects with stable ischaemic heart disease and > 0.1 mV ST segment depression on treadmill exercise testing.

INTERVENTIONS

The warm up protocols were 20 minutes of slow exercise at 2.7 km/h, symptom limited graded exercise for a mean of 7.4 (range 5.0 to 10.5) minutes, and three minutes of symptom limited fast exercise of similar maximum intensity.

MAIN OUTCOME MEASURES

ST segment depression during graded treadmill exercise undertaken 10 minutes after each warm up protocol or no warm up exercise.

RESULTS

Compared with exercise with no warm up, the duration of graded exercise after earlier slow warm up increased by 4.9% (95% confidence interval (CI), -3.3% to 13.7%), after graded warm up by 10.3% (95% CI, 5.6% to 15.2%), and after fast warm up by 16% (95% CI, 6.2% to 26.7%). ST segment depression at equivalent submaximal exercise decreased after slow warm up by 27% (95% CI, 5% to 44%), after graded warm up by 31% (95% CI, 17% to 44%), and after fast warm up by 47% (95% CI, 27% to 61%). Compared with slow warm up exercise, the more intense graded and fast warm up protocols significantly increased the duration of second exercise (p = 0.0072) and reduced both peak ST depression (p = 0.0026) and the rate of increase of ST depression (p = 0.0069).

CONCLUSIONS

In patients with exertional angina the size of the warm up response is related to the maximum intensity rather than the duration of first exercise.

Hemostatic markers in acute ischemic stroke. Association with stroke type, severity, and outcome

BACKGROUND AND PURPOSE

Hemostatic markers can identify activation of the coagulation system in stroke patients. We evaluated whether the levels of these markers at the time of stroke are correlated with stroke severity, type, or mortality.

METHODS

We measured fibrinopeptide A, cross-linked D-dimer, and beta-thromboglobulin in 70 patients within 1 week of stroke. We examined the association between the level of each of these markers and survival. We adjusted for the possible confounding effect of age, stroke type, or stroke severity using a multivariate Cox proportional hazards model.

RESULTS

The median follow-up was 1.22 years. Fourteen patients died during follow-up. Univariate survival analysis identified age (hazard ratio, 1.06; 95% confidence interval [CI], 1.00 to 1.12), stroke type (hazard ratio, 4.44; 95% CI, 1.29 to 15.23), initial Toronto Stroke Scale score (hazard ratio, 5.05; 95% CI, 2.08 to 12.27), cross-linked D-dimer (hazard ratio, 6.43; 95% CI, 2.83 to 14.62), fibrinopeptide A (hazard ratio, 2.14; 95% CI, 1.26 to 3.63), and beta-thromboglobulin (hazard ratio, 7.63; 95% CI, 2.22 to 26.28) as significantly associated with mortality. In a multivariate model, initial stroke severity and each of the hemostatic markers were independently associated with subsequent mortality.

CONCLUSIONS

Elevated hemostatic markers after acute ischemic stroke identify patients with increased risk for mortality. This association appears to be independent of stroke severity or stroke type.

Clinical hyperthermia with a new device: the current sheet applicator

PURPOSE

The current sheet applicator (CSA) is a newly developed microwave hyperthermia device. Advantages over commercial microwave applicators include its small size and high ratio of heating area to physical aperture area. These physical characteristics make the CSA excellent for heating constricted areas and allow the use of arrays of CSAs over large surfaces. This study examines the clinical efficacy of the CSA for heating superficial malignant tumors.

METHODS AND MATERIALS

From December 1989 through October 1991, 19 patients with recurrent or metastatic superficial malignant tumors were treated once or twice weekly to 30 hyperthermia fields using one to four CSAs. Each field received from one to four hyperthermia treatments for a total of 74 treatments. The treatment objective was to elevate the tumor temperature to a minimum of 42.5 degrees C for 30 min (2 patients) or 60 min (17 patients). Intratumor temperatures were measured with percutaneous fiberoptic thermometry probes. All patients received concurrent fractionated radiation therapy with total dose ranging from 20 to 65 Gy (median 46 Gy). Seventeen of the 30 fields had been previously irradiated to a median dose of 50 Gy.

RESULTS

Mean values for the maximum temperature, average temperature, and minimum temperature were 43.6 degrees C +/- 1.0, 42.2 degrees C +/- 1.4, and 41.0 degrees C +/- 1.5, respectively. Mean values for T50 and T90 were 42.2 degrees C +/- 1.1 and 41.0 degrees C +/- 1.3, respectively. The overall response rate for all assessable fields was 96%. Only Only three responding tumors have progressed with a median follow-up period of 6 months. Treatment related morbidity was generally mild and self-limited.

CONCLUSION

The CSA is a promising new microwave hyperthermia device capable of heating superficial tumors to therapeutic temperatures. When used in combination with radiotherapy, response rates are excellent without excessive toxicity.

Interstitial irradiation versus interstitial thermoradiotherapy for supratentorial malignant gliomas: a comparative survival analysis

PURPOSE

To compare the survival of two groups of patients with supratentorial malignant gliomas who were treated on two sequential protocols with either interstitial thermoradiotherapy or with interstitial irradiation without hyperthermia.

METHODS AND MATERIALS

Between 1988-1992, patients with anaplastic astrocytoma or glioblastoma multiforme were treated at the University of Arizona on a Phase I/II protocol of interstitial thermoradiotherapy with ferro-magnetic seeds. The treatment protocol consisted of debulking surgery, a course of external beam radiotherapy and hyperthermia given immediately before and after brachytherapy. The survival of patients so treated was compared with that of a similar group of patients treated with interstitial brachytherapy alone at the Barrows Neurological Institute between 1982-1990.

RESULTS

Twenty-five patients with primary tumors treated at the time of initial presentation with thermoradiotherapy were compared with a control group of 37 patients treated with interstitial brachytherapy alone. All primary patients were followed for a minimum of 34 months post implant. Multivariate analysis based on proportional hazards models showed that hyperthermia (p = 0.027), patient age (p < or = 0.00001) and histology (anaplastic astrocytoma vs. glioblastoma multiforme, p = 0.0017) were the only factors significantly associated with survival in this data set. From the fitted model, the hazard of dying when treated with hyperthermia was .53 times (95% confidence intervals 0.29-0.94) than that of the control group. In addition, we treated a small group of patients with recurrent tumors (13 with brachytherapy alone, and eight with thermoradiotherapy) and found no survival difference (p = 0.62).

CONCLUSION

Within the constraints of the selection factors and the different treatment parameters used in these studies, we conclude that an interstitial thermoradiotherapy boost confers a statistically significant survival benefit to patients with primary high grade gliomas when compared to interstitial brachytherapy alone.

v-jun oncogene suppresses both phorbol ester-induced cell invasion and stromelysin gene expression in a mouse papilloma cell line

The viral jun (v-jun) oncogene encodes a transcription factor that can participate in the transactivation of genes through the AP-1 complex. Evidence indicates that the ability of v-jun to transform cells and stimulate transcription depends on the cell type. We have asked whether expression of the v-jun gene in benign tumor forming mouse keratinocytes that already express an activated c-rasHa oncogene would cause malignant progression. Our results showed that the v-jun transfection did not result in malignant progression; instead, we made the unexpected observation that the ability of these cells to invade reconstituted basement membrane matrix (in vitro) in response to the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate, was suppressed. This phenomenon could, in part, be explained by the suppression of the induction by phorbol ester of expression of the metalloproteinase, stromelysin (transin). Of interest was the finding that 12-O-tetradecanoylphorbol-13-acetate induction of other cellular genes known to be regulated by AP-1 was not inhibited in the benign tumor cells expressing v-jun.

Prevention of photocarcinogenesis and UV‐induced immunosuppression in mice by topical tannic acid

Topical application of tannic acid, a phenolic antioxidant derived from plants, was found to inhibit the cutaneous carcinogenesis and the immunosuppression induced by ultraviolet B (UVB) irradiation with no visible toxicity. BALB/cAnNTacfBR mice were treated with 200 micrograms of tannic acid three times weekly for two weeks before UV treatments began and throughout the experiment. UVB irradiation consisted of five 30-minute exposures per week to banks of six FS40 Westinghouse sunlamps. In the photocarcinogenesis study, mice received a total dose of approximately 1.09 x 10(6) J/m2. Skin cancer incidence in UV-irradiated mice was 75% at 26 weeks after the first UV exposure; tannic acid reduced this to 42%. Immunosuppression induced by UVB irradiation normally prevents the host from rejecting antigenic syngeneic UV-induced tumors. Immunosuppression in these experiments was measured by a passive transfer assay. Tumor challenges grew to an average of 88 +/- 20, 36 +/- 11, and 20 +/- 8 mm2 in naive recipients of splenocytes from UVB-irradiated mice, nonirradiated control mice, and UVB-irradiated mice treated with tannic acid, respectively. Thus topical tannic acid treatment prevented the transfer of enhanced tumor susceptibility with splenocytes from UVB-irradiated mice.

A comparison of survival between radiosurgery and stereotactic implants for malignant astrocytomas

The purpose of this paper is to compare the survival of three groups of patients with high grade supratentorial gliomas who were treated on three sequential protocols with surgical resection, external beam fractionated radiotherapy and a boost to the residual contrasting enhancing mass by either interstitial brachytherapy (IB, n = 33), by interstitial thermoradiotherapy (IT, n = 25) or by stereotactic radiosurgery (SRS, n = 19). The primary aim of this study was to evaluate the role of different boosting techniques in the initial management of primary brain tumors. External beam radiotherapy doses were escalated from one study to the next so that the median doses given to the IB, the IT, and the SRS groups were 41.4 Gy, 48.4 Gy, and 59.4 Gy, respectively. The median dose of interstitial irradiation or stereotactic radiosurgery, were 40 Gy, 32.2 Gy and 10 Gy, respectively, for the same groups. Follow-up was such that all living patients had been followed for a minimum of 30, 27, 4 months in the IB, IT, and SRS groups, respectively; hence, twelve-month survival was 52% (95% CI: 34%-69%), 80% (95% CI: 64%-96%), and 51% (95% CI: 24%-78%) in the same respective groups. Using a multivariate Cox proportional hazards model, treatment with IT conferred a survival advantage over IB (p = 0.029). Furthermore, survival of patients treated with SRS did not significantly differ from that of patients treated with an implant with or without hyperthermia.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of the metalloproteinase matrilysin in DU-145 cells increases their invasive potential in severe combined immunodeficient mice

Human prostate cancer displays a high degree of variability in its rate of spread, which could be due largely to differences in the invasive potential of the tumor cells. The degradation of the basal lamina and stromal extracellular matrix is mediated in part by the secretion of matrix metalloproteinases (MMPs). Matrilysin (PUMP-1, MMP-7) and gelatinase A (M(r) 72,000 type IV collagenase, MMP-2) have been shown to be overexpressed in prostate carcinoma. We have expressed the single MMP matrilysin in the tumorigenic but nonmetastatic human prostate tumor cell line DU-145 to determine if matrilysin has a functional role in prostate tumor cell invasion. DU-145 cells expressing matrilysin were significantly more invasive than vector-only transfected cell lines as assayed by a severe combined immunodeficient mouse model of tumor cell invasion. Vector-only transfected DU-145 cells injected i.p. into severe combined immunodeficient mice invaded the diaphragm in only 1 of 9 mice (11%), whereas matrilysin-transfected DU-145 cells invaded the diaphragm in 12 of 18 mice (66%). The difference between the controls and matrilysin-transfected cells was statistically significant (P < 0.006). These results suggest a functional role for matrilysin in the initial invasion of prostate cancer through the epithelial basal lamina and into the surrounding stroma.

Treatment of malignant gliomas with interstitial irradiation and hyperthermia

A Phase I study of interstitial thermoradiotherapy for high-grade supratentorial gliomas has been completed. The objective of this trial was to test the feasibility and toxicity of hyperthermia induced by ferromagnetic implants in the treatment of intracranial tumors. The patient population consisted of 16 males and 12 females, with a median age of 44 years and a median Karnofsky score of 90. Nine patients had anaplastic astrocytoma while 19 had glioblastoma multiforme. Twenty two patients were treated at the time of their initial diagnosis with a course of external beam radiotherapy (median dose 48.4 Gy) followed by an interstitial implant with Ir-192 (median dose 32.7 Gy). Six patients with recurrent tumors received only an interstitial implant (median dose 40 Gy). Median implant volume for all patients was 55.8 cc and median number of treatment catheters implanted per tumor was eighteen. A 60-minute hyperthermia treatment was given through these catheters just before and right after completion of brachytherapy. Time-averaged temperatures of all treatments were computed for sensors located within the core of (> 5 mm from edge of implant), and at the periphery of the implant (outer 5 mm). The percentage of sensors achieving an average temperature > 42 degrees C was 61% and 35%, respectively. Hyperthermia was generally well tolerated; however, there have been 11 minor toxicities, which resolved with conservative management, and one episode of massive edema resulting in the death of a patient. In addition, there were three major complications associated with the surgical implantation of the catheters. Preliminary survival analysis shows that 16 of the 28 patients have died, with a median survival of 20.6 months from diagnosis. We conclude that interstitial hyperthermia of brain tumors with ferromagnetic implants is feasible and carries significant but acceptable morbidity given the extremely poor prognosis of this patient population.