Asanguinous Del Nido Cardioplegia for an Aortic Valve Replacement Patient with Cold Agglutinins.

A patient with known cold agglutinins requiring an aortic valve replacement was referred for surgery. Asanguinous, Del Nido cardioplegia was used for myocardial protection. Warm induction followed by cold infusion prevented any agglutination and eliminated the need for subsequent cardioplegia doses. Following the cross-clamp period, the heart returned to normal sinus rhythm without need for defibrillation. Postoperative ejection fraction and systolic function were normal.

Study Design and Rationale for the Phase 3 Clinical Development Program of Enobosarm, a Selective Androgen Receptor Modulator, for the Prevention and Treatment of Muscle Wasting in Cancer Patients (POWER Trials).

Muscle wasting in cancer is a common and often occult condition that can occur prior to overt signs of weight loss and before a clinical diagnosis of cachexia can be made. Muscle wasting in cancer is an important and independent predictor of progressive functional impairment, decreased quality of life, and increased mortality. Although several therapeutic agents are currently in development for the treatment of muscle wasting or cachexia in cancer, the majority of these agents do not directly inhibit muscle loss. Selective androgen receptor modulators (SARMs) have the potential to increase lean body mass (LBM) and hence muscle mass, without the untoward side effects seen with traditional anabolic agents. Enobosarm, a nonsteroidal SARM, is an agent in clinical development for prevention and treatment of muscle wasting in patients with cancer (POWER 1 and 2 trials). The POWER trials are two identically designed randomized, double-blind, placebo-controlled, multicenter, and multinational phase 3 trials to assess the efficacy of enobosarm for the prevention and treatment of muscle wasting in subjects initiating first-line chemotherapy for non-small-cell lung cancer (NSCLC). To assess enobosarm's effect on both prevention and treatment of muscle wasting, no minimum weight loss is required. These pivotal trials have pioneered the methodological and regulatory fields exploring a therapeutic agent for cancer-associated muscle wasting, a process hereby described. In each POWER trial, subjects will receive placebo (n = 150) or enobosarm 3 mg (n = 150) orally once daily for 147 days. Physical function, assessed as stair climb power (SCP), and LBM, assessed by dual-energy X-ray absorptiometry (DXA), are the co-primary efficacy endpoints in both trials assessed at day 84. Based on extensive feedback from the US Food and Drug Administration (FDA), the co-primary endpoints will be analyzed as a responder analysis. To be considered a physical function responder, a subject must have ≥10 % improvement in physical function compared to baseline. To meet the definition of response on LBM, a subject must have demonstrated no loss of LBM compared with baseline. Secondary endpoints include durability of response assessed at day 147 in those responding at day 84. A combined overall survival analysis for both studies is considered a key secondary safety endpoint. The POWER trials design was established with extensive clinical input and collaboration with regulatory agencies. The efficacy endpoints are a result of this feedback and discussion of the threshold for clinical benefit in patients at risk for muscle wasting. Full results from these studies will soon be published and will further guide the development of future anabolic trials. Clinical Trial ID: NCT01355484. https://clinicaltrials.gov/ct2/show/NCT01355484 , NCT01355497. https://clinicaltrials.gov/ct2/show/NCT01355497?term=g300505&rank=1 .

Effects of enobosarm on muscle wasting and physical function in patients with cancer: a double-blind, randomised controlled phase 2 trial.

BACKGROUND: Cancer-induced muscle wasting begins early in the course of a patient's malignant disease, resulting in declining physical function and other detrimental clinical consequences. This randomised, double-blind, placebo-controlled phase 2 trial assessed the efficacy and safety of enobosarm, a selective androgen receptor modulator, in patients with cancer. METHODS: We enrolled male (>45 years) and female (postmenopausal) patients with cancer who were not obese and who had at least 2% weight loss in the previous 6 months. Participants were randomly assigned (1:1:1 ratio, by computer generated list, block size three, stratified by cancer type) to receive once-daily oral enobosarm 1 mg, 3 mg, or placebo for up to 113 days at US and Argentinian oncology clinics. The sponsor, study personnel, and participants were masked to assignment. The primary endpoint was change in total lean body mass from baseline, assessed by dual-energy x-ray absorptiometry. Efficacy analyses were done only in patients who had a baseline and an on-treatment assessment in the protocol-specified window of within 10 days before baseline or first study drug, and within 10 days of day 113 or end of study (evaluable efficacy population). Adverse events and other safety measurements were assessed in the intention-to-treat (safety) population. This trial is registered with ClinicalTrials.gov, number NCT00467844. FINDINGS: Enrolment started on July 3, 2007, and the last patient completed the trial on Aug 1, 2008. 159 patients were analysed for safety (placebo, n=52; enobosarm 1 mg, n=53; enobosarm 3 mg, n=54). The evaluable efficacy population included 100 participants (placebo, n=34; enobosarm 1 mg, n=32; enobosarm 3 mg, n=34). Compared with baseline, significant increases in total lean body mass by day 113 or end of study were noted in both enobosarm groups (enobosarm 1 mg median 1·5 kg, range -2·1 to 12·6, p=0·0012; enodosarm 3 mg 1·0 kg, -4·8 to 11·5, p=0·046). Change in total lean body mass within the placebo group (median 0·02 kg, range -5·8 to 6·7) was not significant (p=0·88). The most common serious adverse events were malignant neoplasm progression (eight of 52 [15%] with placebo vs five of 53 [9%] with enobosarm 1 mg vs seven of 54 [13%] with enobosarm 3 mg), pneumonia (two [4%] vs two [4%] vs three [6%]), and febrile neutropenia (three [6%vs one [2%] vs none). None of these events were deemed related to study drug. INTERPRETATION: Cancer cachexia is an unmet medical need and our data suggest that use of enobosarm might lead to improvements in lean body mass, without the toxic effects associated with androgens and progestational agents. FUNDING: GTx.

Toremifene to reduce fracture risk in men receiving androgen deprivation therapy for prostate cancer.

PURPOSE: Androgen deprivation therapy is associated with fracture risk in men with prostate cancer. We assessed the effects of toremifene, a selective estrogen receptor modulator, on fracture incidence in men receiving androgen deprivation therapy during a 2-year period. MATERIALS AND METHODS: In this double-blind, placebo controlled phase III study 646 men receiving androgen deprivation therapy for prostate cancer were assigned to toremifene (80 mg by mouth daily) and 638 were assigned to placebo. Subjects were followed for 2 years. The primary study end point was new vertebral fractures. Secondary end points included fragility fractures, bone mineral density and lipid changes. RESULTS: The 2-year incidence of new vertebral fractures was 4.9% in the placebo group vs 2.5% in the toremifene group, a significant relative risk reduction of 50% (95% CI -1.5 to 75.0, p = 0.05). Toremifene significantly increased bone mineral density at the lumbar spine, hip and femoral neck vs placebo (p <0.0001 for all comparisons). There was a concomitant decrease in markers of bone turnover (p <0.05 for all comparisons). Toremifene also significantly improved lipid profiles. Venous thromboembolic events occurred more frequently with toremifene than placebo with 7 subjects (1.1%) in the placebo group experiencing a venous thromboembolic event vs 17 (2.6%) in the toremifene group. Other adverse events were similar between the groups. CONCLUSIONS: Toremifene significantly decreased the incidence of new vertebral fractures in men receiving androgen deprivation therapy for prostate cancer. It also significantly improved bone mineral density, bone turnover markers and serum lipid profiles.

Low-carbohydrate diets in type 1 diabetes: balancing benefits and risks.

PURPOSE OF REVIEW: Interest in the use of calorie restriction with low-carbohydrate diets for patients with type 1 diabetes appears to be increasing despite physicians' discomfort about its longer term outcomes. A divergence in opinion regarding the balance of benefits and safety may lead to patient disengagement from conventional medical supervision. This review describes the current evidence regarding the benefits and risks of these diets and suggests a way forward to addressing this potential misalignment between the aims of patients and their physicians. RECENT FINDINGS: Benefits on glycaemia are observed in many studies, with improved HbA1c, time within target range and reduced glycaemic variability. A characteristic lipid profile with high LDL cholesterol is observed in many patients, but association with future cardiovascular events is undefined. A negative impact on growth has been identified in the paediatric population, and impact on mental health and disordered eating is of theoretical concern, without measurement in clinical studies. SUMMARY: Patients will continue to trial and, with immediate glycaemic benefits, potentially remain on lower carbohydrate diets irrespective of concern by treating physicians about potential longer term risks. A supportive multidisciplinary approach with greater nutritional supervision and more research is required, to allow these patients to achieve their desired glycaemic outcomes without compromising longer term safety.

Racial differences in bone mineral density and fractures in men receiving androgen deprivation therapy for prostate cancer.

PURPOSE: Whether race influences bone loss and fracture risk during androgen deprivation therapy for prostate cancer is unknown. Using data from a prospective clinical trial we compared bone mineral density and fracture between African-American and Caucasian men receiving androgen deprivation therapy. MATERIALS AND METHODS: A total of 516 subjects were in the placebo group of a 2-year randomized placebo controlled fracture prevention trial, and were African-American (68) or Caucasian (448). We compared baseline characteristics, changes in bone mineral density and rates of new fractures between races. RESULTS: Compared to Caucasian men, African-American men had higher baseline hip bone mineral density (mean ± SD 0.98 ± 0.15 vs 0.91 ± 0.15 gm/m(2), p = 0.001) and similar spine bone mineral density (1.09 ± 0.22 vs 1.11 ± 0.22, p = 0.51). There was no difference in prevalent vertebral fractures between African-American and Caucasian men (7.4% vs 15.0%, p = 0.13). The percentage change in hip bone mineral density at 2 years was similar between African-American and Caucasian men (mean ± SE -2.21% ± 0.59% vs -2.54% ± 0.26%, p = 0.65). Changes in bone mineral density of the lumbar spine were also similar between African-American and Caucasian men (-1.74% ± 0.69% vs -1.30% ± 0.33%, p = 0.64). No new vertebral fractures were reported in African-American men but 2 fractures were reported in Caucasian men. CONCLUSIONS: In a clinical trial African-American men receiving androgen deprivation therapy for prostate cancer have a greater hip bone mineral density and tended to have fewer prevalent vertebral fractures than Caucasian men. Despite a lower baseline risk of osteoporosis and fracture, African-American men experience a decrease in bone mineral density similar to that of Caucasian men.

Factors associated with vertebral fractures in men treated with androgen deprivation therapy for prostate cancer.

PURPOSE: Androgen deprivation therapy for prostate cancer causes accelerated loss of bone mineral density and is associated with increased fracture risk. We evaluated risk factors associated with vertebral fractures among men enrolled in a fracture prevention trial. MATERIALS AND METHODS: Analysis included men receiving androgen deprivation therapy for prostate cancer and enrolled in a phase III fracture prevention trial. All men were 70 years old or older or had a low bone mineral density (T-score less than -1.5 for the lumbar spine or total hip). We analyzed demographic and laboratory characteristics of men with and those without vertebral fractures at study entry. RESULTS: Of the 1,244 subjects 162 (13.0%) had a vertebral fracture at baseline. The 2 factors significantly associated with vertebral fractures were white race (p=0.028 compared with nonwhite race) and osteoporosis (p=0.002 for osteoporosis at any site, p=0.053 for osteoporosis at the spine, p=0.002 for osteoporosis at the hip). Lower bone mineral density was also significantly associated with vertebral fractures when analyzed as a continuous variable. Factors not associated with vertebral fractures included age, country of residence, androgen deprivation therapy duration at baseline, androgen deprivation therapy mode, body mass index, testosterone, estradiol, C-telopeptide, bone specific alkaline phosphatase and osteocalcin. Results were similar in analyses limited to men 70 years old or older. CONCLUSIONS: White race and low bone mineral density were significantly associated with vertebral fractures in this study of men treated with androgen deprivation for prostate cancer. These observations should inform the assessment and management of fracture risk among such men.

Toremifene decreases vertebral fractures in men younger than 80 years receiving androgen deprivation therapy for prostate cancer.

PURPOSE: Androgen deprivation therapy is associated with an increased fracture risk. In a recent phase III trial toremifene significantly decreased vertebral fractures in men on androgen deprivation therapy. Similar to other selective estrogen receptor modulators, toremifene was associated with an increase in venous thromboembolic events with the greatest risk in men 80 years old or older. In this post hoc analysis we evaluated the efficacy and safety of toremifene in men younger than 80 years. MATERIALS AND METHODS: This analysis included 847 men younger than 80 years, of whom 430 received toremifene 80 mg by mouth daily and 417 received placebo for up to 24 months. The primary end point was new vertebral fractures. Secondary end points included fragility fractures, bone mineral density and safety. RESULTS: Compared with placebo, toremifene decreased the relative risk of new vertebral fractures by 79.5% (95% CI 29.8-94.0, p <0.005). The new vertebral fracture incidence was 1.0% for toremifene and 4.8% for placebo (absolute risk reduction 3.8%). Compared with placebo, toremifene significantly decreased the incidence of nontraumatic fracture or greater than 7% bone loss by 24 months (p <0.0001). Toremifene also significantly increased bone mineral density at all measured sites (all comparisons p <0.001). The incidence of venous thromboembolic events was similar in the toremifene and placebo groups (2.1% and 1.0%, respectively, p = 0.26). The rates of other adverse events were also similar between the groups. CONCLUSIONS: Toremifene significantly decreased new vertebral fractures in men younger than 80 years receiving androgen deprivation therapy for prostate cancer. The risk of venous thromboembolic events was lower than in the overall study population, suggesting an improved risk-benefit profile in younger men.

Toremifene to reduce fracture risk in men receiving androgen deprivation therapy for prostate cancer.

PURPOSE: Androgen deprivation therapy is associated with fracture risk in men with prostate cancer. We assessed the effects of toremifene, a selective estrogen receptor modulator, on fracture incidence in men receiving androgen deprivation therapy during a 2-year period. MATERIALS AND METHODS: In this double-blind, placebo controlled phase III study 646 men receiving androgen deprivation therapy for prostate cancer were assigned to toremifene (80 mg by mouth daily) and 638 were assigned to placebo. Subjects were followed for 2 years. The primary study end point was new vertebral fractures. Secondary end points included fragility fractures, bone mineral density and lipid changes. RESULTS: The 2-year incidence of new vertebral fractures was 4.9% in the placebo group vs 2.5% in the toremifene group, a significant relative risk reduction of 50% (95% CI -1.5 to 75.0, p = 0.05). Toremifene significantly increased bone mineral density at the lumbar spine, hip and femoral neck vs placebo (p <0.0001 for all comparisons). There was a concomitant decrease in markers of bone turnover (p <0.05 for all comparisons). Toremifene also significantly improved lipid profiles. Venous thromboembolic events occurred more frequently with toremifene than placebo with 7 subjects (1.1%) in the placebo group experiencing a venous thromboembolic event vs 17 (2.6%) in the toremifene group. Other adverse events were similar between the groups. CONCLUSIONS: Toremifene significantly decreased the incidence of new vertebral fractures in men receiving androgen deprivation therapy for prostate cancer. It also significantly improved bone mineral density, bone turnover markers and serum lipid profiles.

Race, sex, and the regulation of urine osmolality: observations made during water deprivation.

A more concentrated urine is excreted by blacks than whites and by men than women. The purpose of this study was to explore the physiological bases for the race and sex effects during water deprivation when osmoregulation is challenged and differences are amplified. Drinking water was withheld from 17 blacks (10 men) and 19 whites (9 men) for 24 h. Vasopressin (VP) levels and osmolality in plasma (P(osmol)) and urine (U(osmol)) were measured basally and then every 4 h. U(osmol) was higher in blacks at baseline (P = 0.01) and during water deprivation (P = 0.046). Before and during water deprivation, no differences were seen in levels of VP, P(osmol), or the VP-U(osmol) relationship between blacks and whites. Although VP levels were initially higher in men (P < 0.02 for samples collected over the first 12 h), over the last 12 h of water deprivation, U(osmol) was higher (P = 0.027) and more responsive to the level of VP (in terms of slopes, P = 0.0001) in women than men. Our results suggest that, after a period of water deprivation, there develops a sensitivity of the collecting duct to VP that is greater in women. Although U(osmol) is higher in blacks, the race difference in water conservation did not appear to result from differences in the level of VP or the sensitivity of the collecting duct to VP. Upstream effects such as Na(+) uptake in the thick ascending limb, with its ensuing effects on water reabsorption, need to be considered in future studies of the relationship of race to water conservation.

Copper-on-copper homoepitaxy studied by infrared spectroscopy of adsorbed CO.

Infrared spectroscopy of adsorbed CO was used to characterize the dependence of surface structure on deposition temperature during homoepitaxial growth on Cu(100). Intensity borrowing due to dipole coupling greatly enhances the absorption signal due to defect-bonded CO, making it possible to detect and quantify defect concentrations at the level of a few percent. For deposition temperatures between 300 and 400 K, the defect density increases slightly with decreasing deposition temperature but remains below 2%. There is a sharp increase in defect density, up to 5%-6%, as the deposition temperature is decreased from 300 to 250 K. At lower deposition temperatures, there is some sign of a leveling off in defect density, but the IR absorption spectrum becomes so broad that meaningful analysis becomes impractical, while visible degradation of the low-energy electron diffraction pattern indicates worsening surface order. No indication of "re-entrant" ordering at low temperatures was observed for deposition temperatures down to 150 K.

Phase 2 Trial of GTx-758, an Estrogen Receptor Alpha Agonist, in Men With Castration-Resistant Prostate Cancer.

INTRODUCTION: Novel estrogen therapy has the potential to be efficacious, with a favorable adverse event profile, in castration-resistant prostate cancer (CRPC). We performed a phase 2 trial to assess the ability of GTx-758, an oral selective estrogen receptor alpha agonist, to result in a ≥ 50% PSA decline by day 90, modulate free testosterone and sex hormone-binding globulin (SHBG) levels, and affect estrogen deficiency adverse events. PATIENTS AND METHODS: CRPC patients received GTx-758 in two dose cohorts, 125 and 250 mg/d. The primary endpoint was the proportion of subjects who experienced a ≥ 50% PSA decline by day 90. Secondary endpoints included changes in testosterone, SHBG, bone turnover markers, and hot flashes, as well as safety. RESULTS: Four (10.5%) of 38 (95% CI, 2.9, 24.8; P = .120) and 10 (25.6%) of 39 patients (95% CI, 13.0, 42.1; P < .001) in the GTx-758 125 and 250 mg/d cohorts, respectively, experienced ≥ 50% PSA decline. SHBG was increased, providing a mechanism for notable decreases in free testosterone. In the 250 mg/d cohort, 9 men presented with moderate to severe hot flashes, and after 12 weeks, 4 (44%) of 9 reported either mild or no hot flashes (P = .001). The rate of venous thromboembolic events was 0% and 5.1% in the 125 and 250 mg/d arms, respectively. CONCLUSION: GTx-758 has clinical activity for CRPC in a dose-dependent fashion. GTx-758 resulted in a reduction in hot flashes. On the basis of these findings, further clinical investigation of novel estrogen therapies is warranted.

High-throughput screening compatible cell-based assay for interrogating activated notch signaling.

Aberrant Notch pathway function is associated with a wide array of developmental disorders, cancers, and neurodegenerative diseases. Thus, strategies to modulate Notch signaling may facilitate therapeutic intervention. Ligand binding to Notch receptors at the cell surface results in a series of cleavage events that release Notch intracellular domain (NICD) fragments that translocate to the nucleus where they function as transcriptional activators of downstream transcriptional programs. We have developed a cell-based assay that can be used to screen for modulators of NICD signaling by engineering HeLa cervical cancer cells with a Notch response element driving beta-lactamase (BLA) reporter gene expression along with a tetracycline-inducible NICD expression system. Induction of NICD expression leads to increased BLA reporter activity that can be knocked down using NICD-specific RNA interference as well as RNA interference against endogenous components of the NICD transactivation complex. Profiling of 19 known compounds in this assay identified several previously undescribed modulators of NICD signaling. The Wnt pathway inhibitor ICG-001 antagonized NICD signaling, whereas the histone deacetylase inhibitor suberoylanilide hydroxamic acid, the heat shock protein 90 inhibitor 17-(allylamino)-17-demethoxygeldanamycin, and the dual phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin inhibitor PI-103 each further activated the NICD-driven reporter activity. The AKT inhibitor triciribine and the PI3K inhibitor GDC-0941 also resulted in the enhanced reporter activity, strongly implicating a role for the PI3K/AKT pathway in regulating NICD signaling. Together this cell-based assay system provides a sensitive, quantitative readout for NICD signaling that is amenable to high-throughput screening for NICD pathway modulators.

Relationships among severity of osteonecrosis, pain, range of motion, and functional mobility in children, adolescents, and young adults with acute lymphoblastic leukemia.

BACKGROUND AND PURPOSE: Up to 38% of children receiving treatment for acute lymphoblastic leukemia (ALL) develop osteonecrosis, often without symptoms. Little is known about the association between the degree of osteonecrosis and functional mobility in this population. The purpose of this study was to examine relationships among the degree of osteonecrosis, pain, range of motion (ROM), and functional mobility in people with ALL. SUBJECTS: Thirty-three subjects aged 5 to 27 years with ALL and osteonecrosis participated. METHODS: The extent of osteonecrosis was determined by magnetic resonance imaging (MRI) of the hip and knee according to 2 classification systems, including the Association Research Circulation Osseous (ARCO) and a knee staging scale. Pain, hip and knee ROM, and the Timed Up and Down Stairs (TUDS) Test were used as measures. RESULTS: Correlations were observed between ARCO and hip pain (r=.34), between hip flexion ROM and hip pain (r=-.34), and between knee pain and time on the TUDS Test (r=-.35). DISCUSSION AND CONCLUSION: Physical therapists should consider that people with ALL may have hip or knee osteonecrosis without clinical symptoms. This notion supports the need for MRI in addition to a comprehensive examination of functional mobility.

Performance of Medtronic Hybrid Closed-Loop Iterations: Results from a Randomized Trial in Adolescents with Type 1 Diabetes.

This study investigates the performance of an iteration of the Medtronic hybrid closed-loop (HCL) algorithm, which utilizes sensor glucose values non-adjunctively for bolus advice, recognizes sustained hyperglycemia, suggests insulin bolus correction, and includes more accommodative SmartGuard™ automode parameters that aim to improve function and usability. Adolescents aged 13-17 years with type 1 diabetes >1 year, glycated hemoglobin (HbA1c) 7.0%-10%, currently using Continuous Subcutaneous Insulin Infusion were randomized to the control Medtronic standard HCL algorithm or to the intervention Medtronic HCL with enhancements. Participants attended a 7-day and 7-night nonstructured camp setting. Twelve participants (mean age 15 years, seven males, five females, mean HbA1c 8.55%) completed the study. For the control group, time in target glucose sensor range (3.9-10 mmol/L) was 63.68% ± 10.74% at baseline and changed to 75.85% ± 8.49% during the study (relative Δ19%). Time spent in <2.8 mmol/L was 0.61% ± 0.79% at baseline for the control group and changed to 0.32% ± 0.31% during the study for the control group (relative Δ48%). In the intervention group, time in target glucose sensor range (3.9-10 mmol/L) was 52.15% ± 9.55% at baseline and changed to 74.32% ± 8.41% during the study (relative Δ42%). Time spent in <2.8 mmol/L was 1.07% ± 1.77% at baseline for the intervention group and changed to 0.24% ± 0.14% during the study for the intervention group (relative Δ78%). Mean sensor glucose was 8.05 ± 0.73 mmol/L and 8.22 ± 0.56 mmol/L for the control and intervention participants. SmartGuard automode exit frequency was 0.54 exits per person per day for control and 0.12 exits per person per day for the intervention. Participants were in active SmartGuard automode 97.1% and 98.8% of the time for the control and intervention, respectively. Alarm frequency was 2.1 alarms per person per day for the control arm, and 0.26 alarms per person per day in the intervention arm. Feasibility of the enhanced HCL algorithm was demonstrated with a high proportion of time spent in SmartGuard automode and target glucose range. The iterative changes resulted in less SmartGuard automode exits without compromising glycemic control.

Phase I trial of imatinib in children with newly diagnosed brainstem and recurrent malignant gliomas: a Pediatric Brain Tumor Consortium report.

This study estimated the maximum tolerated dose (MTD) of imatinib with irradiation in children with newly diagnosed brainstem gliomas, and those with recurrent malignant intracranial gliomas, stratified according to use of enzyme-inducing anticonvulsant drugs (EIACDs). In the brainstem glioma stratum, imatinib was initially administered twice daily during irradiation, but because of possible association with intratumoral hemorrhage (ITH) was subsequently started two weeks after irradiation. The protocol was also amended to exclude children with prior hemorrhage. Twenty-four evaluable patients received therapy before the amendment, and three of six with a brainstem tumor experienced dose-limiting toxicity (DLT): one had asymptomatic ITH, one had grade 4 neutropenia and, one had renal insufficiency. None of 18 patients with recurrent glioma experienced DLT. After protocol amendment, 3 of 16 patients with brainstem glioma and 2 of 11 patients with recurrent glioma who were not receiving EIACDs experienced ITH DLTs, with three patients being symptomatic. In addition to the six patients with hemorrhages during the DLT monitoring period, 10 experienced ITH (eight patients were symptomatic) thereafter. The recommended phase II dose for brainstem gliomas was 265 mg/m(2). Three of 27 patients with brainstem gliomas with imaging before and after irradiation, prior to receiving imatinib, had new hemorrhage, excluding their receiving imatinib. The MTD for recurrent high-grade gliomas without EIACDs was 465 mg/m(2), but the MTD was not established with EIACDs, with no DLTs at 800 mg/m(2). In summary, recommended phase II imatinib doses were determined for children with newly diagnosed brainstem glioma and recurrent high-grade glioma who were not receiving EIACDs. Imatinib may increase the risk of ITH, although the incidence of spontaneous hemorrhages in brainstem glioma is sufficiently high that this should be considered in studies of agents in which hemorrhage is a concern.

Microplate orbital mixing improves high-throughput cell-based reporter assay readouts.

Reporter assays are commonly used for high-throughput cell-based screening of compounds, cDNAs, and siRNAs due to robust signal, ease of miniaturization, and simple detection and analysis. Among the most widely used reporter genes is the bioluminescent enzyme luciferase, which, when exposed to its substrate luciferin upon cell lysis, yields linear signal over a dynamic range of several orders of magnitude. Commercially available luciferase assay formulations have been developed permitting homogeneous, single-step cell lysis and reporter activity measurements. Assay conditions employed with these formulations are typically designed to minimize well-to-well luminescence variability due to variability in dispensing, evaporation, and incomplete sample mixing. The authors demonstrate that incorporating a microplate orbital mixing step into 96- and 384-well microplate cell-based luciferase reporter assays can greatly improve reporter readouts. They have found that orbital mixing using commercially available mixers facilitates maximal luciferase signal generation from high cell density-containing samples while minimizing variability due to partial cell lysis, thereby improving assay precision. The authors fully expect that widespread availability of mixers with sufficiently small orbits and higher speed settings will permit gains in signal and precision in the 1536-well format as well.

An improved beta-lactamase reporter assay: multiplexing with a cytotoxicity readout for enhanced accuracy of hit identification.

A problem inherent to the use of cellular assays for drug discovery is their sensitivity to cytotoxic compounds, which can result in false hits from certain compound screens. To alleviate the need to follow-up hits from a reporter assay with a separate cytotoxicity assay, the authors have developed a multiplexed assay that combines the readout of a beta-lactamase reporter with that of a homogeneous cytotoxicity indicator. Important aspects to the development of the multiplexed format are addressed, including results that demonstrate that the IC(50) values of 40 select compounds in a beta-lactamase reporter assay for nuclear factor kappa B and SIE pathway antagonists are not affected by the addition of the cytotoxicity indicator. To demonstrate the improvement in hit confirmation, the multiplexed assay was used to perform a small-library screen (7728 compounds) for serotonin 5HT1A receptor antagonists. Hits identified from analysis of the beta-lactamase reporter data alone were compared to those hits determined when the reporter and cytotoxicity data generated from the multiplexed assay were combined. Confirmation rates were determined from compound follow-up using dose-response analysis of the potential antagonist hits identified by the initial screen. In this representative screen, the multiplexed assay approach yielded a 19% reduction in the number of compounds flagged for follow-up, with a 37% decrease in the number of false hits, demonstrating that multiplexing a beta-lactamase reporter assay with a cytotoxicity readout is a highly effective strategy for reducing false hit rates in cell-based compound screening assays.

Phase I trial of intrathecal spartaject busulfan in children with neoplastic meningitis: a Pediatric Brain Tumor Consortium Study (PBTC-004).

PURPOSE: A phase I trial of intrathecal Spartaject Busulfan (SuperGen, Inc., San Ramon, CA) was conducted in children with neoplastic meningitis following recurrent primary brain tumors to describe toxicities, estimate the maximum tolerated dose (MTD), and document evidence of responses to this agent. EXPERIMENTAL DESIGN: The continuous reassessment method was used to assign cohorts of patients to doses of intrathecal Spartaject Busulfan via an Ommaya reservoir and/or lumbar puncture twice weekly for 2 weeks followed by an assessment of toxicity and response. Patients with stable disease or an objective response continued to receive intrathecal Spartaject Busulfan plus systemic chemotherapy at regular intervals. Cerebrospinal fluid and blood were obtained for pharmacokinetic studies in patients with Ommaya reservoirs after the first dose of intrathecal Spartaject Busulfan. Seven evaluable patients were assigned to the starting dose of 5 mg, two patients to 7.5 mg, three patients to 10 mg, seven patients to 13 mg, and four patients to 17 mg. RESULTS: Between September 2000 and May 2003, 28 patients were enrolled in this study. Twenty-three patients (median age, 8.8 years; range, 2.5-19.5 years) were evaluable for estimating the MTD, and dose-limiting toxicities were observed in three and included grade 3 vomiting (n = 1 at 5 mg), grade 3 headache (n = 1 at 17 mg), and grade 3 arachnoiditis (n = 1 at 17 mg). Pharmacokinetic data showed that post-infusion concentrations of busulfan ranged from 50 to 150 microg/mL and declined to <1 microg/mL within 5 hours. CONCLUSIONS: Intrathecal Spartaject Busulfan was well tolerated in children with neoplastic meningitis from brain tumors, and the recommended dose for future phase II studies is 13 mg.

Establishing the use of body mass index as an indicator of nutrition risk in children with cancer.

BACKGROUND: The negative health consequences of malnutrition in the pediatric oncology patient are well known. The purpose of this study was to determine the usefulness of body mass index (BMI) for age as a tool to prospectively identify pediatric cancer patients at risk for malnutrition and to determine the BMI percentile that would be required to identify at-risk patients. METHODS: This study was conducted by a retrospective chart review of 1839 newly diagnosed acute lymphoblastic leukemia patients at St. Jude Children's Research Hospital. Those falling below the 10(th) percentile on any one category of height for age (HFA), weight for age (WFA), or weight for height (WFH) were classified with regard to nutrition risk and compared with those identified as at risk by BMI for age (BFA). The BMI percentiles of the lower 9(th)-11(th) percentile patients on the HFA, WFA, and WFH growth charts were averaged in an attempt to determine a useful value to identify nutrition risk. RESULTS: Lack of agreement was found to exist between BFA and HFA in identifying patients at risk for malnutrition, and also between BFA and WFA. Significant agreement was found to exist between BFA and WFH. The BMI percentile required to identify those at risk for malnutrition by the other growth charts would classify too many patients as being at risk for malnutrition to be considered clinically useful. CONCLUSIONS: Although research has shown BMI is appropriate to use in the nutrition assessment of children, its usefulness has not been confirmed in the pediatric oncology patient; therefore, further study is warranted. BFA assessment should be included in the nutrition survey of new pediatric oncology patients, along with other parameters, but it cannot be recommended as the sole indicator of nutrition status at this time.