Ninety-day outcome rates of a prospective cohort of consecutive patients with mild ischemic stroke

BACKGROUND AND PURPOSE

Prior studies have shown that patients with mild ischemic stroke have substantial disability rates at hospital discharge. We sought to determine disability rates at 90 days among patients not treated with thrombolytic therapy and explore the role of early neurological worsening.

METHODS

We reviewed a prospective cohort of 136 consecutive patients with mild deficits (National Institutes of Health Stroke Scale score ≤ 5) presenting within 24 hours of onset and no baseline disability. Baseline MRIs were performed on all subjects. Five-day MRIs were performed on a prespecified subcohort.

RESULTS

Among 136 patients, 40 (29%; 95% CI, 22%-38%) had poor outcomes (modified Rankin Scale score 2-6) at 90 days. Early worsening (4-point National Institutes of Health Stroke Scale increase; 25% versus 1%, P<0.001) and acute infarct growth (>10% on MRI-diffusion-weighted imaging; 79% versus 53%, P=0.02) from baseline to 5 days were more common among those with poor outcome.

CONCLUSIONS

Patients with mild ischemic stroke have substantial rates (29%) of disability at 90 days.

Dose-finding design for multi-drug combinations

BACKGROUND

Most of the current designs used for Phase I dose finding trials in oncology will either involve only a single cytotoxic agent or will impose some implicit ordering among the doses. The goal of the studies is to estimate the maximum tolerated dose (MTD), the highest dose that can be administered with an acceptable level of toxicity. A key working assumption of these methods is the monotonicity of the dose-toxicity curve.

PURPOSE

Here we consider situations in which the monotonicity assumption may fail. These studies are becoming increasingly common in practice, most notably, in phase I trials that involve combinations of agents. Our focus is on studies where there exist pairs of treatment combinations for which the ordering of the probabilities of a dose-limiting toxicity cannot be known a priori.

METHODS

We describe a new dose-finding design which can be used for multiple-drug trials and can be applied to this kind of problem. Our methods proceed by laying out all possible orderings of toxicity probabilities that are consistent with the known orderings among treatment combinations and allowing the continual reassessment method (CRM) to provide efficient estimates of the MTD within these orders. The design can be seen to simplify to the CRM when the full ordering is known.

RESULTS

We study the properties of the design via simulations that provide comparisons to the Bayesian approach to partial orders (POCRM) of Wages, Conaway, and O'Quigley. The POCRM was shown to perform well when compared to other suggested methods for partial orders. Therefore, we comapre our approach to it in order to assess the performance of the new design.

LIMITATIONS

A limitation concerns the number of possible orders. There are dose-finding studies with combinations of agents that can lead to a large number of possible orders. In this case, it may not be feasible to work with all possible orders.

CONCLUSIONS

The proposed design demonstrates the ability to effectively estimate MTD combinations in partially ordered dosefinding studies. Because it relaxes the monotonicity assumption, it can be considered a multivariate generalization of the CRM. Hence, it can serve as a link between single and multiple-agent dosefinding trials.

Maintaining patency with packed red blood cell infusions: comparison of IV normal saline infusion vs. normal saline syringe method

As blood products are being used more judiciously, registered nurses need to develop practices to facilitate the effective administration of these products. The study results suggest both the syringe push method and the continuous infusion method of normal saline provide adequate line patency during packed red blood cell infusions through peripheral catheters.

Continual reassessment method for partial ordering

Much of the statistical methodology underlying the experimental design of phase 1 trials in oncology is intended for studies involving a single cytotoxic agent. The goal of these studies is to estimate the maximally tolerated dose, the highest dose that can be administered with an acceptable level of toxicity. A fundamental assumption of these methods is monotonicity of the dose-toxicity curve. This is a reasonable assumption for single-agent trials in which the administration of greater doses of the agent can be expected to produce dose-limiting toxicities in increasing proportions of patients. When studying multiple agents, the assumption may not hold because the ordering of the toxicity probabilities could possibly be unknown for several of the available drug combinations. At the same time, some of the orderings are known and so we describe the whole situation as that of a partial ordering. In this article, we propose a new two-dimensional dose-finding method for multiple-agent trials that simplifies to the continual reassessment method (CRM), introduced by O'Quigley, Pepe, and Fisher (1990, Biometrics 46, 33-48), when the ordering is fully known. This design enables us to relax the assumption of a monotonic dose-toxicity curve. We compare our approach and some simulation results to a CRM design in which the ordering is known as well as to other suggestions for partial orders.

The MG-QOL15 for following the health-related quality of life of patients with myasthenia gravis

The MG-QOL15 is helpful in informing the clinician about the patient's perception of the extent of and dissatisfaction with myasthenia gravis (MG)-related dysfunction. The aims of this study were to determine the usefulness of the MG-QOL15 for following individuals with MG and to guide clinical researchers who plan to use the MG-QOL15. We assessed sensitivity and specificity for detecting clinical change and evaluated test-retest reliability. Sensitivities and specificities of various cut-points of change in scores are presented. Also presented are means and standard deviations of MG-QOL15 scores for all patients and for subgroups of patients. The test-retest reliability coefficient was 98.6%. The MG-QOL15 has an acceptable longitudinal construct validity. We consider this instrument to be most useful for informing the clinician about the patient's perception and tolerance of MG-related dysfunction. More objective measures, such as the MG Composite, should also be used to follow disease severity.

Educational needs: what female patients want from their cardiovascular health care providers

This descriptive convenience study used a card sort technique to determine the self-identified cardiovascular health care needs of 81 female patients as compared to those identified as most important by their health care providers.

Phosphorylation of RalB is important for bladder cancer cell growth and metastasis

RalA and RalB are monomeric G proteins that are 83% identical in amino acid sequence but have paralogue-specific effects on cell proliferation, metastasis, and apoptosis. Using in vitro kinase assays and phosphosite-specific antibodies, here we show phosphorylation of RalB by protein kinase C (PKC) and RalA by protein kinase A. We used mass spectrometry and site-directed mutagenesis to identify S198 as the primary PKC phosphorylation site in RalB. Phorbol ester [phorbol 12-myristate 13-acetate (PMA)] treatment of human bladder carcinoma cells induced S198 phosphorylation of stably expressed FLAG-RalB as well as endogenous RalB. PMA treatment caused RalB translocation from the plasma membrane to perinuclear regions in a S198 phosphorylation-dependent manner. Using RNA interference depletion of RalB followed by rescue with wild-type RalB or RalB(S198A) as well as overexpression of wild-type RalB or RalB(S198A) with and without PMA stimulation, we show that phosphorylation of RalB at S198 is necessary for actin cytoskeletal organization, anchorage-independent growth, cell migration, and experimental lung metastasis of T24 or UMUC3 human bladder cancer cells. In addition, UMUC3 cells transfected with a constitutively active RalB(G23V) exhibited enhanced subcutaneous tumor growth, whereas those transfected with phospho-deficient RalB(G23V-S198A) were indistinguishable from control cells. Our data show that RalA and RalB are phosphorylated by different kinases, and RalB phosphorylation is necessary for in vitro cellular functions and in vivo tumor growth and metastasis.

Multifactor clinical score and outcome of mechanical ventilation weaning trials: Burns Wean Assessment Program

BACKGROUND

The Burns Wean Assessment Program is a 26-factor weaning assessment worksheet and scoring instrument used to reduce practice variability in the clinical management of patients receiving mechanical ventilation. The instrument has been tested in patients in a medical-surgical intensive care unit, but further testing in different populations of adult patients is needed.

OBJECTIVES

To determine the relationship between Burns Wean Assessment Program scores and outcomes of weaning trials in patients treated with mechanical ventilation for 3 or more days.

METHODS

For 5 years in 5 adult critical care units (surgical, medical, neurological, thoracic-cardiovascular, and coronary care), advanced practice nurses collected scores within 24 hours of a weaning attempt. All patients were managed similarly by using a multidisciplinary pathway, the Burns Wean Assessment Program checklist, protocols for weaning trials, and sedation guidelines.

RESULTS

Of 1889 weaning attempts, 1669 (88%) were successful, and 220 (12%) were unsuccessful. Weaning outcomes did not differ according to sex, but significantly more trials were successful in younger patients than in older patients (P = .002) and in patients in different units (P = .01). Regardless of unit, patients with Burns Wean Assessment Program scores greater than 50 were significantly more likely to be weaned successfully (P = .001) than were patients with lower scores.

CONCLUSIONS

Systematic tracking of the factors and scores on the Burns Wean Assessment Program may be helpful in care planning and management and in determining weaning potential.

Abstract 311: Phosphorylation of RalB by PKC regulates its intracellular distribution and promotion of bladder tumor growth

RalA and RalB are members of the Ras family of monomeric G proteins that are 83% identical in amino acid sequence, but have paralog-specific effects on cancer cell proliferation, metastasis and apoptosis. Using in vitro kinase assays and phosphosite specific antibodies, here we show paralog-specific phosphorylation of RalA by PKA and RalB by PKC. Mutagenesis identified Ser194 as the single PKA phosphorylation site in RalA and S198 as the primary PKC phosphorylation site in RalB. Phorbol ester treatment of human bladder carcinoma cells induced phosphorylation of S198 in both stably expressed FLAG-RalB and endogenous RalB. Compared to activated RalB(G23V) that localized at plasma membrane, phosphosite mutant RalB(G23V-S198A) colocalized with GFP-Rab11, a recycling endosome marker. Phorbol ester treatment enhanced anchorage independent growth of UMUC3 human bladder carcinoma cells stably transfected with wild type RalB or activated RalB(G23V), but not with phosphosite mutants RalB(S198A) or RalB(G23V-S198A). Furthermore, UMUC3 cells transfected with RalB(G23V) exhibited enhanced subcutaneous tumor growth compared to vector transfected cells, but cells expressing RalB(G23V-S198A) had growth indistinguishable from the controls. Our data demonstrate that RalA and RalB are specifically phosphorylated by different kinases, and RalB phosphorylation regulates its intracellular localization and in vivo tumor growth promotion. Phosphorylation of RalA and RalB by different kinases may contribute to the biological specificity of these closely related proteins.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 311.

Construct and concurrent validation of the MG-QOL15 in the practice setting

Health-related quality of life (HRQOL) estimates can play an important role in patient care by providing information about the patient's perception of impairment and disability and the degree to which the patient tolerates disease manifestations. The 15-item myasthenia gravis quality of life scale (MG-QOL15) is an HRQOL evaluative instrument specific to patients with myasthenia gravis (MG) that was designed to be easy to administer and interpret. In this multicenter study we demonstrate the construct validity of the MG-QOL15 in the practice setting. To assess the construct validity, score distributions were examined for test items in different MG patient groups that represent the clinical spectrum of the disease. For example, patients in remission more frequently scored test items as normal than did patients in other groups. Patients with lower (better) MG composite scores also more frequently scored items as normal than did patients with higher (worse) scores. There was also appropriate correlation between the MG-QOL15 and the other MG-specific scales studied. The study findings shed light on what troubles MG patients. The MG-QOL15 has construct validity in the clinical practice setting and represents an efficient and valuable tool for assessing HRQOL for patients with MG.

Glucose Regulation in Acute Stroke Patients (GRASP) trial: a randomized pilot trial

BACKGROUND AND PURPOSE

Hyperglycemia is associated with worse outcome in patients with acute stroke.

METHODS

We conducted a prospective, randomized, multicenter, 3-arm trial (tight control [target 70 to 110 mg/dL], loose control [target 70 to 200 mg/dL], and control usual care [70 to 300 mg/dL]) to assess the feasibility and safety of 2 insulin infusion protocol targets in patients with acute ischemic stroke. The planned sample was 72 subjects.

RESULTS

A total of 74 subjects were enrolled. Seventy-two (97%) had data available for the primary analyses and 73 (99%) had 3-month clinical outcome data. Median age was 67 years, median National Institutes of Health Stroke Scale score was 8, median glucose was 163 mg/dL, and median time to randomization was 10.7 hours. Fifty-nine percent of patients were diabetic, 35% received thrombolysis, and 14% of subjects died within 3 months. The loose control and usual care groups had median glucose concentrations of 151 mg/dL. The tight control group had a median glucose concentration of 111 mg/dL. The loose control group spent 90% of the first 24 hours in target and the tight group 44% of time in target. There was only one symptomatic patient with hypoglycemia in the loose control group (4%) and zero in the tight control group. The overall rates of hypoglycemia (<55 mg/dL) were 4% in control, 4% in loose, and 30% in tight. Exploratory efficacy analysis was conducted.

CONCLUSIONS

Insulin infusion for patients with acute ischemic stroke is feasible and safe using the insulin infusion protocol in the Glucose Regulation in Acute Stroke Patients (GRASP) trial. Exploratory efficacy analysis supports further comparative study.

Prediction of muscle-invasive bladder cancer using urinary proteomics

PURPOSE

Minimally invasive methods of predicting the risk of muscle-invasive urothelial bladder carcinoma may expedite appropriate therapy and reduce morbidity and cost.

EXPERIMENTAL DESIGN

Here, capillary electrophoresis coupled mass spectrometry was used to identify urinary polypeptide bladder cancer biomarkers in 127 patients. These markers were used to construct a panel discriminating muscle-invasive from noninvasive disease, which was refined in 297 additional samples from healthy volunteers, patients with malignant and nonmalignant genitourinary conditions. Sequencing of panel polypeptides was then done. Finally, the ability of the panel to predict muscle-invasive disease was evaluated prospectively in 130 bladder carcinoma patients. Four sequenced polypeptides formed a panel predictive of muscle-invasive disease.

RESULTS

Prospective evaluation of this panel revealed a sensitivity of 81% [95% confidence interval (CI), 69-90] and specificity of 57% (95% CI, 45-69) for muscle-invasive disease. Multivariate analysis revealed the panel (P < 0.0001) and tumor grade (P = 0.0001), but not urine cytology, predict muscle invasion. A model including grade and panel polypeptide levels improved sensitivity [92% (95% CI, 82-97)] and specificity [68% (95% CI, 55-79)] for muscle-invasive disease. A model score of >0.88 provided a negative predictive value of 77% and positive predictive value of 90% for muscle invasion.

CONCLUSIONS

Use of urinary peptides seems promising in estimating the probability a patient harbors muscle-invasive urothelial bladder cancer. These peptides may also shed novel insights into the biology of bladder tumor progression not obtainable by other methods. Clinical trials seem warranted to evaluate the effect of this approach on practice.

A comparison of developmental versus functional assessment in the rehabilitation of young children

BACKGROUND

The purpose of this study was to explore the differences in and potential uses of information derived from developmental vs. functional assessment during the acute rehabilitation of very young children with acquired brain injury. Both methods of assessment are typically used during hospitalization in order to assist in developing individualized goals and outcome measures. With the trend of shortened hospital stays, effective assessment for determining optimal treatment goals and outcomes becomes increasingly important. The results from a developmental and a functional assessment obtained on 23 inpatient children below 6 years of age who had experienced either an acquired brain injury or encephalitis were compared. The data was collected through a retrospective chart review spanning 4 years.

METHODS AND OUTCOME MEASURES

Each child received a cognitive and a language test using either the Early Learning Accomplishment Profile (E-LAP) or the Learning Accomplishment Profile Diagnostic (LAP-D) for the developmental assessment measure. The Functional Independence Measure for Children (WeeFIM) was used as a functional assessment. Summary statistics and frequencies were calculated for variables including age and diagnosis. Partial Pearson correlations and 95% confidence intervals were calculated between the functional and developmental assessments, adjusting for the amount of time between administrations of the two exams. Pearson correlations were computed between length of hospital stay and performance on the developmental and functional quotients.

RESULTS

Moderate, statistically significant Pearson partial correlations were found between the E-LAP/LAP-D cognitive quotient and the WeeFIM cognitive quotient (r = 0.42, 95% CI (0, 0.72)), the E-LAP/LAP-D language quotient and the WeeFIM cognitive quotient (r = 0.55, 95% CI (0.17, 0.79)) and the E-LAP/LAP-D cognitive quotient and the WeeFIM total quotient (r = 0.50, 95% CI (0.10, 0.76)). An inverse correlation was found between the length of stay and the E-LAP/ LAP-D cognitive quotient (r = -0.68, 95% CI (-0.86, -0.34)) as well as the E-LAP/LAP-D language quotient (r = -0.61, 95% CI (-0.83, -0.23)).

CONCLUSIONS

The moderate but limited correlations between developmental and functional assessments may be attributed to differences in the two forms of assessment including the test items, their administration and scoring. While both forms of assessment were thought to be useful for developing individualized treatment goals and measuring outcomes, there were advantages and disadvantages to each.

Integrin agonists as adjuvants in chemotherapy for melanoma

PURPOSE

Metastatic melanomas are generally resistant to chemotherapy and radiation, even when wild-type for p53. These tumors often grow in small nests where many of the cells have little contact with extracellular matrix (ECM). Previous work showed that M21 melanomas undergo apoptosis in response to chemotherapy when cells are adherent to ECM but not in suspension. Thus, reduced integrin-dependent adhesion to ECM could mediate therapy resistance. The goal of this study was to test whether stimulation of integrin signaling could increase chemotherapeutic efficacy.

EXPERIMENTAL DESIGN

Colony forming assays and survival assays were used to test the responses of melanoma lines in vitro. Severe combined immunodeficient mice with subcutaneous human melanomas received chemotherapy with or without reagents that stimulate integrin signaling; tumor volume was then monitored over time.

RESULTS

Clonal growth assays confirmed that M21 cells showed reduced sensitivity to the chemotherapeutic drug 1-beta-D-arabinofuranosylcytosine (araC). When five additional primary melanoma lines were screened, 80% showed higher sensitivity when adherent compared with suspended. Subcutaneous M21 tumors in vivo showed minimal ECM between tumor cells. To evaluate the importance of integrin signaling in chemoresistance in this model, mice were treated with araC, with or without the multivalent snake venom disintegrin contortrostatin or the activating anti-beta1 integrin antibody TS2/16. Although araC, TS2/16, or contortrostatin alone had little effect on M21 tumor growth, combining araC with either integrin signaling reagents strongly reduced growth (P = 0001).

CONCLUSIONS

Loss of integrin-mediated adhesion is rate limiting for therapeutic response in this model. Combining chemotherapy with reagents that stimulate integrin signaling may therefore provide a new approach to therapy.

Clinical and consumer trial performance of a sensitive immunodiagnostic home test that qualitatively detects low concentrations of sperm following vasectomy

PURPOSE

Compliance with post-vasectomy semen analysis could be improved with the availability of a simple, rapid and accurate home test. SpermCheck Vasectomy, a highly sensitive lateral flow immunochromatographic diagnostic device, was designed to detect extreme oligospermia or azoospermia in men after vasectomy. We report the results of clinical and consumer testing of SpermCheck.

MATERIALS AND METHODS

A prospective, noncomparative observational study assessed the ability of SpermCheck Vasectomy to predict post-vasectomy sperm counts obtained using a hemacytometer procedure based on standard World Health Organization methodology. Consumer studies evaluated ease of use.

RESULTS

A cohort of 144 post-vasectomy semen samples was tested in the clinical trial. SpermCheck was 96% accurate in predicting whether sperm counts were greater or less than a threshold of 250,000 sperm per ml, a level associated with little or no risk of pregnancy. Sensitivity was 93% (95% CI 79% to 98%) and specificity was 97% (91% to 99%). The positive predictive value of the test was 93% (79% to 98%), and most importantly the negative predictive value was 97% (91% to 99%). The test gave a positive result 100% of the time at sperm concentrations of 385,000/ml or greater. Consumer studies with 109 lay volunteers showed that SpermCheck was easy to use. Volunteers obtained the correct or expected test result in every case and the correct response rate on a 20 question survey about the test was 97%.

CONCLUSIONS

SpermCheck Vasectomy, a simple and reliable immunodiagnostic test that can provide evidence of vasectomy success or failure, offers a useful alternative to improve compliance with post-vasectomy sperm monitoring. It is currently the only Food and Drug Administration approved test for this purpose.

Less is more, or almost as much: a 15-item quality-of-life instrument for myasthenia gravis

We describe the process whereby a recently developed myasthenia gravis (MG)-specific quality-of-life (QOL) instrument was reduced from 60 items to 15 items while maintaining potential usefulness in the clinic and in prospective treatment trials. In data from a recently completed prospective trial of mycophenolate mofetil (MMF) in MG, the MG-QOL15 correlated as highly as the 60-item MG-QOL for physical and social domains of the 36-item health survey of the Medical Outcomes Study Short Form (SF-36). Correlation coefficients for the MG-QOL15 were similar to the 60-item MG-QOL for the Quantitative Myasthenia Gravis (QMG), MG-specific Manual Muscle Testing (MG-MMT), and the MG-specific Activities of Daily Living (MG-ADL) scores at week 0 and for change in scores from week 0 to week 12 in the MMF trial. Using the physician global impression at week 12 of the trial as the "gold standard," the MG-QOL15 demonstrated high sensitivity. Because the MG-QOL15 instrument can be quickly and easily administered and interpreted, it is a potential QOL measure for treatment trials and the clinical evaluation of patients with MG.

Statin therapy improves outcomes after valvular heart surgery

BACKGROUND

The beneficial effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG Co-A) reductase inhibitors (statins) in patients undergoing coronary artery bypass grafting have been recognized. Reduced mortality rates and clinical events have been demonstrated. These outcomes were examined in patients taking statins who underwent cardiac valve operations.

METHODS

This retrospective study included 447 consecutive patients undergoing valve operations between July 2004 and February 2006; 203 patients (45.6%) received statins preoperatively and postoperatively vs 244 who did not. Preoperative risk factors and outcome data for both cohorts were compared. Primary outcomes included 30-day mortality, renal failure, and postoperative stroke.

RESULTS

The statin group had more comorbidities. Although they had increased risk factors, including previous stroke (30 of 203 vs 16 of 244, p = 0.004), diabetes (66 of 203 vs 32 of 244, p < 0.0001), cerebrovascular disease (45 of 203 vs 24 of 244, p = 0.003), and dyslipidemia (191 of 203 vs 63 of 244, p < 0.0001), they had better outcomes. The unadjusted odds ratio (OR) for the composite end point of death/stroke/renal failure was 1.90 (95% confidence interval [CI], 0.95 to 3.76; p = 0.068) favoring the statin group. By univariate analysis, the adjusted OR for the composite end point demonstrated a benefit with statin therapy: diabetes, 2.29 (95% CI, 1.16 to 4.71; p = 0.024); stroke, 2.15 (95% CI, 1.06 to 4.35; p = 0.034); and renal dysfunction, 2.05 (95% CI, 1.02 to 4.13; p = 0.045).

CONCLUSIONS

Statin therapy in this population undergoing cardiac valve procedures was associated with decreased postoperative morbidity and death. The mechanism may be independent of statins' lipid-lowering effects. A prospective, randomized-control trial of statin therapy in this population is warranted.

When should students learn essential physical examination skills? Views of internal medicine clerkship directors in North America

PURPOSE

To determine whether any consensus exists among internal medicine clerkship directors regarding when students should acquire proficiency in selected physical examination (PE) skills.

METHOD

In 2004, the annual survey of Clerkship Directors in Internal Medicine (CDIM) included a question about the timing of PE-skills proficiency. (CDIM members are from 123 U.S. and Canadian medical schools.) A total of 259 members (123 institutional and 136 individual members) were asked the following question about 39 common physical examination skills, selected using a consensus process among the authors and members of the CDIM Council: "When in the medical school curriculum should medical students acquire proficiency for the following skills?"

RESULTS

There were 157 respondents, an overall response rate of 60%. There were 89 (72%) responding institutional members and 68 (50%) responding individual members. Respondents agreed that 31 (80%) of the skills should be learned by the end of the clerkship year. However, considerable variability existed regarding when in the curriculum those skills should be learned: for only 18 of 39 skills was there 80% agreement on skills-learning timing. CDIM members were divided on whether normal examination findings should be learned before or during the clerkships.

CONCLUSIONS

Variability existed among CDIM members regarding their expectations for the timing of student physical examination learning in the undergraduate medical curriculum. Creating a common vision among clerkship directors and faculty regarding what neophyte clinicians must learn to do and when they are expected to be able to do it will help to address the issue of physical examination proficiency standards of medical students.

Radiosensitization and modulation of p44/42 mitogen-activated protein kinase by 2-Methoxyestradiol in prostate cancer models

2-Methoxyestradiol (2ME2) is an endogenous estradiol metabolite that inhibits microtubule polymerization, tumor growth, and angiogenesis. Because prostate cancer is often treated with radiotherapy, and 2ME2 has shown efficacy as a single agent against human prostate carcinoma, we evaluated 2ME2 as a potential radiosensitizer in prostate cancer models. A dose-dependent decrease in mitogen-activated protein kinase phosphorylation was observed in human PC3 prostate cancer cells treated with 2ME2 for 18 h. This decrease correlated with in vitro radiosensitization measured by clonogenic assays, and these effects were blocked by the expression of constitutively active MEK. Male nude mice with subcutaneous PC3 xenografts in the hind leg were treated with 2ME2 (75 mg/kg) p.o. for 5 days, and 2 Gy radiation fractions were delivered each day at 4 h after drug treatment. A statistically significant super-additive effect between radiation and 2ME2 was observed in this subcutaneous model, using analysis of within-animal slopes. A PC-3M orthotopic model was also used, with bioluminescence imaging as an end point. PC-3M cells stably expressing the luciferase gene were surgically implanted into the prostates of male nude mice. Mice were given oral doses of 2ME2 (75 mg/kg), with radiation fractions (3 Gy) delivered 4 h later. Mice were then imaged weekly for 4 to 5 weeks with a Xenogen system. A significant super-additive effect was also observed in the orthotopic model. These data show that 2ME2 is an effective radiosensitizing agent against human prostate cancer xenografts, and that the mechanism may involve a decrease in mitogen-activated protein kinase phosphorylation by 2ME2.

Rap2 regulates androgen sensitivity in human prostate cancer cells

BACKGROUND

Progression of prostate cancer to a fatal androgen-independent disease is associated with activation of MAP kinase, consistent with chronic stimulation of the Ras-signaling pathway. We have previously shown that Ras activation is sufficient to induce androgen-independent growth of prostate cancer cells. One mechanism of MAP kinase regulation is modulation of Ras signaling by other Ras family members, the Rap gene paralogs Rap1a/b and Rap2a/b. Here we ask if Rap proteins play a role in determining androgen sensitivity of human prostate cancer cells either alone or in the context of an activated Ras.

METHODS

To evaluate the role of Rap proteins in androgen responsiveness we use Rap over-expression with or without mutated Ras co-transfection and Rap siRNA knockdown to evaluate androgen-dependent prostate-specific antigen (PSA) promoter reporter expression and cell growth in androgen-dependent LNCaP and independent C4-2 human prostate cancer cells.

RESULTS

Rap1 is equally expressed between LNCaP and C4-2 cells and thus we focused on Rap2 which is minimally expressed in C4-2. Rap2a affects androgen-dependent PSA reporter expression in a dose-dependent manner in LNCaP and C4-2 cells. Low levels of Rap2a enhance PSA reporter expression, whereas higher concentrations inhibit expression. We show that Rap2a antagonizes the enhanced PSA reporter expression conferred by an active RasV12 gene in prostate cancer cells. siRNA knockdown data indicate that Rap2 has a greater effect on androgen-stimulated growth in LNCaP than in C4-2 cells.

CONCLUSIONS

We show that Rap2 is involved in androgen-mediated transcriptional and growth responses of human prostate cancer cells.

Effects of lifestyle intervention on health care costs: Improving Control with Activity and Nutrition (ICAN)

OBJECTIVE

To evaluate program and health care costs of a lifestyle intervention in a high-risk obese population.

DESIGN

Twelve-month randomized controlled trial comparing lifestyle case management to usual care.

SUBJECTS/SETTING

Health plan members (n=147) with obesity (body mass index >/=27) and type 2 diabetes.

INTERVENTION

Lifestyle case management entailed individual and group education, support, and referrals by registered dietitians. Those in the usual-care group received educational material.

MAIN OUTCOME MEASURES

Medical and pharmaceutical health care costs reimbursed by the participant's primary insurance company.

STATISTICAL ANALYSIS

Total costs were modeled using the four-equation model using previous year cost as a predictor.

RESULTS

Net cost of the intervention was $328 per person per year. After incorporating program costs, mean health plan costs were $3,586 (95% confidence interval [CI]: -$8,036, -$25, P<0.05) lower in case management compared to usual care. The difference was driven by group differences in medical (-$3,316, 95% CI: -$7,829 to -$320, P<0.05) but not pharmaceutical costs (-$239, 95% CI: -$870 to $280, not statistically significant), with fewer inpatient admissions and costs among case management compared with usual care (admission prevalence: 2.8% vs 22.5% respectively, P<0.001).

CONCLUSION

Addition of a modest-cost, registered dietitian-led lifestyle case-management intervention to usual medical care did not increase health care costs and suggested modest cost savings among obese patients with type 2 diabetes. Larger trials are needed to determine whether these results can be replicated in a broader population. The findings can be judiciously applied to support that the addition of a registered dietitian-led lifestyle case-management program to medical care does not increase health care costs.

Subcellular Localization Modulates Activation Function 1 Domain Phosphorylation in the Androgen Receptor

Although the steady-state distribution of the androgen receptor (AR) is predominantly nuclear in androgen-treated cells, androgen-bound AR shuttles between the nucleus and the cytoplasm. In the present study we have addressed how nucleocytoplasmic shuttling contributes to the regulation of AR. Nuclear transport signal fusions were used to force AR localization to the nucleus or cytoplasm of prostate cancer cells, and the effect of localization on shuttling, transcription, androgen binding, and phosphorylation was determined. Fusing the simian virus 40 nuclear localization signal or c-Abl nuclear export signal to AR resulted in androgen-independent localization to the nucleus or cytoplasm, respectively. AR forced to the nucleus was transcriptionally active on prostate-specific antigen and mouse mammary tumor virus promoters driving reporter genes. AR forced to the cytoplasm was largely inactive on the prostate-specific antigen promoter, but, surprisingly, AR was active on the mouse mammary tumor virus promoter and on two endogenous genes examined. Thus, highly transient nuclear localization of AR is sufficient to activate transcription. Androgen dissociation rates and the dissociation constant (KD) of AR for androgen were similar whether AR was localized to the cytoplasm or the nucleus, suggesting the ligand-binding cycle of AR is not strictly linked to its compartmentalization. Using phosphosite antibodies, we found that compartmentalization influences the phosphorylation state of AR. We show there is a bias for androgen-dependent phosphorylation of Ser81, Ser256, and Ser308 in the nucleus and androgen-independent phosphorylation of Ser94 in the cytoplasm. We propose that one function of nucleocytoplasmic shuttling is to integrate the signaling environment in the cytoplasm with AR activity in the nucleus.