64 HIGH-DOSE STEROIDS IN HAEMATOLOGICAL MALIGNANCY: A RED FLAG FOR BONE HEALTH

Background

Bone-protective treatment should always be considered when commencing glucocorticoid therapy in individuals at high risk of fracture, as outlined in recent guidelines (National Osteoporosis Guideline Group, July 2018). Despite this, many patients receive high dose glucocorticoids (>7.5mg/kg/day or equivalent for >3 months) during treatment of haematological malignancy without formal assessment of bone health.

Methods

Twenty-five patients with Non-Hodgkin’s Lymphoma (NHL) on high dose steroid chemotherapy protocols were retrospectively assessed. The inclusion criterion was defined as any patient commenced on a cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP) containing protocol from 1/8/2020 to 1/8/21. Data was collected from electronic and written patient records. Information regarding patient age, diagnosis, steroid preparation and dose, presence of risk factors for osteoporosis and calcium and vitamin D prescriptions were collected. Radiological imaging was reviewed to assess for the occurrence of fragility fractures. Each patient had a FRAX® score calculated to assess fracture risk.

Results

The mean age of patients studied was 67 years and equally distributed between males and females. All patients had NHL. 32% (n=25) of patients were identified to be at high risk for fracture (FRAX® score >20% ten-year probability of major osteoporotic fracture). 16% had already established fragility fractures prior to commencing steroid treatment. 28% of patients were females over the age of 70 years. Only 12% of patients received vitamin D and calcium supplementation. No patient commenced bone protection therapy.

Conclusion

Omission of bone health assessment prior to high dose glucocorticoid treatment is prevalent in haematological malignancy and places patients at risk of significant morbidity. Patients are not routinely considered for protective measures including calcium and vitamin D supplementation and bone protection therapy. A simple risk-assessment tool and education to staff and patients prior to glucocorticoid therapy could significantly improve practice in this area. It is now planned to introduce routine risk assessment for this cohort of patients, with re-audit following implementation.

Vaccine-induced thrombosis and thrombocytopenia (VITT) in Ireland: A review of cases and current practices

Since the beginning of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) virus pandemic, several highly effective and safe vaccines have been produced at remarkable speed. Following global implementation of vaccination programmes, cases of thrombosis with thrombocytopenia following administration of adenoviral vector-based vaccines started being reported. In this review we discuss the known pathogenesis and epidemiology of so-called vaccine induced thrombocytopenia and thrombosis (VITT). We consider the available guidelines, diagnostic laboratory tests and management options for these patients. Finally, we discuss important unanswered questions and areas for future research in this novel pathoclinical entity.

Physical Activity Maintenance Following Home-Based, Individually Tailored Print Interventions for African American Women

African American women report low participation in physical activity and are disproportionately burdened by related conditions (obesity, breast, and colon cancer). Physical activity interventions have shown promising results among African American women, but most studies in this area have focused on short-term increases. More enduring changes in health behavior will be needed to eliminate existing health disparities. Thus, the current study examined 12-month physical activity and psychosocial outcomes from a pilot randomized controlled trial (N = 84) of a Home-based Individually tailored Physical activity Print (HIPP) intervention for African American women in the Deep South. Retention was 77.4% at 12 months. HIPP participants increased self-reported moderate-to-vigorous physical activity from 35.1 minutes/week (standard deviation [SD] = 47.8) at baseline to 124 minutes/week (SD = 95.5) at 12 months, compared with the wellness contact control participants who reported increases from 48.2 minutes/week (SD = 51.3) to 102.5 minutes/week (SD = 94.5) over 12 months (between-group p > .05). Results indicate that modest improvements in moderate-to-vigorous physical activity and related psychosocial variables occurred during the active intervention phase (months 0-6) and were sustained during the tapered maintenance period (months 6-12). Low-cost, high-reach, home-based strategies have great potential for supporting sustained participation in physical activity and achieving long-term health benefits among African American women in the Deep South.

Physical Activity and Related Psychosocial Outcomes From a Pilot Randomized Trial of an Interactive Voice Response System-Supported Intervention in the Deep South

BACKGROUND

Physical activity exerts cancer-protective effects, yet most Americans are inactive, especially in the South, where cancer incidence rates are generally higher. Telephone-based approaches can help overcome physical activity intervention barriers in this region (literacy, costs, lack of transportation/technology, distance from facilities) and can be automated via interactive voice response (IVR) systems for improved reach and cost-effectiveness.

AIMS

To evaluate the Deep South IVR-supported Active Lifestyle (DIAL) intervention.

METHOD

A pilot randomized controlled trial was conducted among 63 underactive adults in Birmingham, Alabama, from 2015 to 2017.

RESULTS

Retention was 88.9% at 12 weeks, and ≥75% adherence (IVR contact on at least 63 out of 84 days) was noted among 62.5% of intervention participants. Intervention participants reported larger increases in self-reported minutes of moderate-to-vigorous intensity physical activity from baseline to 12 weeks than the wait-list control arm (median change = 47.5 vs. 5.0 minutes, respectively, p = .09). Moreover, the intervention produced significantly greater increases in physical activity self-regulation ( p < .001) and social support from family ( p = .001) and friends ( p = .009) from baseline to 12 weeks, compared with the wait-list control. Significant decreases in self-reported sleep disturbance also were found in the intervention arm but not among the controls, p < .05. Overall, intervention participants reported being satisfied with the DIAL program (71.4%) and would recommend it to friends (92.9%).

DISCUSSION

Findings support the feasibility, acceptability, and preliminary efficacy of the DIAL intervention.

CONCLUSION

Next steps include intervention refinement in preparation for a fully powered efficacy trial and eventual dissemination to rural counties.

Pilot Trial of a Home-based Physical Activity Program for African American Women

PURPOSE

This study aimed to assess the feasibility of a Home-based, Individually-tailored Physical activity Print (HIPP) intervention for African American women in the Deep South.

METHODS

A pilot randomized trial of the HIPP intervention (N = 43) versus wellness contact control (N = 41) was conducted. Recruitment, retention, and adherence were examined, along with physical activity (7-d physical activity recalls, accelerometers) and related psychosocial variables at baseline and 6 months.

RESULTS

The sample included 84 overweight/obese African American women 50-69 yr old in Birmingham, AL. Retention was high at 6 months (90%). Most participants reported being satisfied with the HIPP program and finding it helpful (91.67%). There were no significant between-group differences in physical activity (P = 0.22); however, HIPP participants reported larger increases (mean of +73.9 min·wk (SD 90.9)) in moderate-intensity or greater physical activity from baseline to 6 months compared with the control group (+41.5 min·wk (64.4)). The HIPP group also reported significantly greater improvements in physical activity goal setting (P = 0.02) and enjoyment (P = 0.04) from baseline to 6 months compared with the control group. There were no other significant between-group differences (6-min walk test, weight, physical activity planning, behavioral processes, stage of change); however, trends in the data for cognitive processes, self-efficacy, outcome expectations, and family support for physical activity indicated small improvements for HIPP participants (P > 0.05) and declines for control participants. Significant decreases in decisional balance (P = 0.01) and friend support (P = 0.03) from baseline to 6 months were observed in the control arm and not the intervention arm.

CONCLUSIONS

The HIPP intervention has great potential as a low-cost, high-reach method for reducing physical activity-related health disparities. The lack of improvement in some domains may indicate that additional resources are needed to help this target population reach national guidelines.

Lower frequency of TLR9 variant associated with protection from breast cancer among African Americans

Introduction

Toll-like receptor 9 (TLR9) is an innate immune system DNA-receptor that regulates tumor invasion and immunity in vitro. Low tumor TLR9 expression has been associated with poor survival in Caucasian patients with triple negative breast cancer (TNBC). African American (AA) patients with TNBC have worse prognosis than Caucasians but whether this is due to differences in tumor biology remains controversial. We studied the prognostic significance of tumor Toll like receptor-9 (TLR9) protein expression among African American (AA) triple negative breast cancer (TNBC) patients. Germline TLR9 variants in European Americans (EAs) and AAs were investigated, to determine their contribution to AA breast cancer risk.

Methods

TLR9 expression was studied with immunohistochemistry in archival tumors. Exome Variant Server and The Cancer Genome Atlas were used to determine the genetic variation in the general EA and AA populations, and AA breast cancer cases. Minor allele frequencies (MAFs) were compared between EAs (n = 4300), AAs (n = 2203), and/or AA breast cancer cases (n = 131).

Results

Thirty-two TLR9 variants had a statistically significant MAF difference between general EAs and AAs. Twenty-one of them affect a CpG site. Rs352140, a variant previously associated with protection from breast cancer, is more common in EAs than AAs (p = 2.20E-16). EAs had more synonymous alleles, while AAs had more rare coding alleles. Similar analyses comparing AA breast cancer cases with AA controls did not reveal any variant class differences; however, three previously unreported TLR9 variants were associated with late onset breast cancer. Although not statistically significant, rs352140 was observed less frequently in AA cases compared to controls. Tumor TLR9 protein expression was not associated with prognosis.

Conclusions

Tumor TLR9 expression is not associated with prognosis in AA TNBC. Significant differences were detected in TLR9 variant MAFs between EAs and AAs. They may affect TLR9 expression and function. Rs352140, which may protect from breast cancer, is 1.6 X more common among EAs. These findings call for a detailed analysis of the contribution of TLR9 to breast cancer pathophysiology and health disparities.

Clinical features predict responsiveness to imatinib in platelet-derived growth factor receptor-alpha-negative hypereosinophilic syndrome

BACKGROUND

With the exception of the presence of the FIP1L1-PDGFRA fusion gene, little is known about predictors of imatinib response in clinically-defined hypereosinophilic syndrome (HES).

METHODS

Subjects with FIP1L1-PDGFRA-myeloid neoplasm (FP; n =12), PDGFRA-negative HES with ≥4 criteria suggestive of a myeloid neoplasm (MHES; n =10), or steroid-refractory PDGFRA-negative HES with <4 myeloid criteria (SR; n = 5) were enrolled in a prospective study of imatinib therapy (NCT00044304: registered at clinicaltrials.gov). The primary outcome was an eosinophil count <1.5 × 109/L at one month and improvement of clinical symptoms. Clinical, molecular, and bone marrow responses to imatinib were assessed. A retrospective cohort of 18 subjects with clinically-defined HES who received imatinib (300-400 mg daily ≥ 1 month) were classified according to the criteria used in the prospective study.

RESULTS

Overall, imatinib response rates were 100% in the FP group (n = 16), 54% in the MHES group (n = 13) and 0% in the SR group (n = 16). The presence of ≥ 4 myeloid features was the sole predictor of response. After ≥ 18 months in complete remission, imatinib was tapered and discontinued in 8 FP and 1 MHES subjects. Seven subjects (6 FP, 1 MHES) remain in remission off therapy for a median of 29 months (range 14-36).

CONCLUSIONS

Clinical features of MHES predict imatinib response in PDGFRA-negative HES.

Rationale, design, and baseline findings from HIPP: A randomized controlled trial testing a home-based, individually-tailored physical activity print intervention for African American women in the Deep South

African American women report high rates of physical inactivity and related health disparities. In our previous formative research, we conducted a series of qualitative assessments to examine physical activity barriers and intervention preferences among African American women in the Deep South. These data were used to inform a 12-month Home-based, Individually-tailored Physical activity Print (HIPP) intervention, which is currently being evaluated against a wellness contact control condition among 84 post-menopausal African American women residing in the metropolitan area of Birmingham, Alabama. This paper reports the rationale, design and baseline findings of the HIPP trial. The accrued participants had an average age of 57 (SD=4.7), a BMI of 32.1 kg/m(2) (SD=5.16) with more than half (55%) having a college education and an annual household income under $50,000 (53.6%). At baseline, participants reported an average of 41.5 min/week (SD=49.7) of moderate intensity physical activity, and 94.1% were in the contemplation or preparation stages of readiness for physical activity. While social support for exercise from friends and family was low, baseline levels of self-efficacy, cognitive and behavioral processes of change, decisional balance, outcome expectations, and enjoyment appeared promising. Baseline data indicated high rates of obesity and low levels of physical activity, providing strong evidence of need for intervention. Moreover, scores on psychosocial measures suggested that such efforts may be well received. This line of research in technology-based approaches for promoting physical activity in African American women in the Deep South has great potential to address health disparities and impact public health.

Utilization of 2013 BRFSS Physical Activity Data for State Cancer Control Plan Objectives: Alabama Data

OBJECTIVES

All comprehensive US cancer control plans mention physical activity and implement physical activity promotion objectives as part of these cancer plans. The purpose of this investigation was to describe the physical activities reported by Alabama adults in the 2013 Behavioral Risk Factor Surveillance System (BFRSS) and to compare these activities by age group and relative exercise intensity.

METHODS

This investigation used data on 6503 respondents from the 2013 BRFSS sample of respondents from Alabama with landline and cellular telephones. Respondents were asked whether they engaged in any physical activities or aerobic exercises such as running, calisthenics, golf, gardening, or walking. Information was collected on strengthening activities such as yoga, sit-ups, push-ups, and using weight machines, free weights, and elastic bands. Relative exercise intensity was estimated for each aerobic activity by comparing the 60% maximal oxygen uptake with metabolic equivalent values.

RESULTS

Approximately two-thirds (63.7%) of respondents reported that they engaged in exercise in the past 30 days; 45.4% participated in enough aerobic activity per week to meet guidelines, and 25.9% met the muscle-strengthening guidelines. Only 10.1% of respondents 65 years old and older met both aerobic and muscle-strengthening guidelines, compared with 15.2% of those 18 to 64 years old (P < 0.05). The most common activity reported for ages 18 to 64 years was walking (53.3%), followed by running (12.7%), and gardening (4.7%). Among adults aged 65 and older, the top three activities were walking (63.2%), gardening (13.3%), and use of a bicycle machine (2.9%). The activity intensity was significantly greater for walking, gardening, and household activities among older adults compared with those younger than age 65.

CONCLUSIONS

Because the recommended levels of physical activity are not met by a majority of Alabama residents, it is important to incorporate this information into state cancer objectives. Older adults may have higher relative energy costs compared with younger adults. Future studies should discern whether activities previously classified as low intensity have adequate health benefits, especially for cancer survivors and older adults with comorbidities.

Baseline participant characteristics and risk for dropout from ten obesity randomized controlled trials: a pooled analysis of individual level data

INTRODUCTION

Understanding participant demographic characteristics that inform the optimal design of obesity RCTs have been examined in few studies. The objective of this study was to investigate the association of individual participant characteristics and dropout rates (DORs) in obesity randomized controlled trials (RCT) by pooling data from several publicly available datasets for analyses. We comprehensively characterize DORs and patterns in obesity RCTs at the individual study level, and describe how such rates and patterns vary as a function of individual-level characteristics.

METHODS

We obtained and analyzed nine publicly-available, obesity RCT datasets that examined weight loss or weight gain prevention as a primary or secondary endpoint. Four risk factors for dropout were examined by Cox proportional hazards including sex, age, baseline BMI, and race/ethnicity. The individual study data were pooled in the final analyses with a random effect for study, and HR and 95% CIs were computed.

RESULTS

Results of the multivariate analysis indicated that the risk of dropout was significantly higher for females compared to males (HR= 1.24, 95% CI = 1.05, 1.46). Hispanics and Non-Hispanic blacks had a significantly higher dropout rate compared to non-Hispanic whites (HR= 1.62, 95% CI = 1.37, 1.91; HR= 1.22, 95% CI = 1.11, 1.35, respectively). There was a significantly increased risk of dropout associated with advancing age (HR= 1.02, 95% CI = 1.01, 1.02) and increasing BMI (HR= 1.03, 95% CI = 1.03, 1.04).

CONCLUSION/SIGNIFICANCE

As more studies may focus on special populations, researchers designing obesity RCTs may wish to oversample in certain demographic groups if attempting to match comparison groups based on generalized estimates of expected dropout rates, or otherwise adjust a priori power estimates. Understanding true reasons for dropout may require additional methods of data gathering not generally employed in obesity RCTs, e.g. time on treatment.

A study of the relationship between food group recommendations and perceived stress: findings from black women in the Deep South

Black women in the Deep South experience excess morbidity/mortality from obesity-related diseases, which may be partially attributable to poor diet. One reason for poor dietary intake may be high stress, which has been associated with unhealthy diets in other groups. Limited data are available regarding dietary patterns of black women in the Deep South and to our knowledge no studies have been published exploring relationships between stress and dietary patterns among this group. This cross-sectional study explored the relationship between stress and adherence to food group recommendations among black women in the Deep South. Participants (n = 355) provided demographic, anthropometric, stress (PSS-10), and dietary (NCI ASA-24 hour recall) data. Participants were obese (BMI = 36.5 kg/m(2)) and reported moderate stress (PSS-10 score = 16) and minimal adherence to Dietary Guidelines for Americans food group recommendations (1/3 did not meet recommendations for any food group). Participants reporting higher stress had higher BMIs than those reporting lower stress. There was no observed relationship between stress and dietary intake in this sample. Based on these study findings, which are limited by potential misreporting of dietary intake and limited variability in stress measure outcomes, there is insufficient evidence to support a relationship between stress and dietary intake.

Wnt5a suppresses tumor formation and redirects tumor phenotype in MMTV-Wnt1 tumors

Wnt5a is a non-canonical signaling Wnt that has been implicated in tumor suppression. We previously showed that loss of Wnt5a in MMTV-PyVmT tumors resulted in a switch in tumor phenotype resulting in tumors with increased basal phenotype and high Wnt/β-catenin signaling. The object of this study was to test the hypothesis that Wnt5a can act to inhibit tumors formed by activation of Wnt/β-catenin signaling. To this end, we characterized tumor and non-tumor mammary tissue from MMTV-Wnt1 and double transgenic MMTV-Wnt1;MMTV-Wnt5a mice. Wnt5a containing mice demonstrated fewer tumors with increased latency when compared to MMTV-Wnt1 controls. Expression of markers for basal-like tumors was down-regulated in the tumors that formed in the presence of Wnt5a indicating a phenotypic switch. Reduced canonical Wnt signaling was detected in double transgenic tumors as a decrease in active β-catenin protein and a decrease in Axin2 mRNA transcript levels. In non-tumor tissues, over-expression of Wnt5a in MMTV-Wnt1 mammary glands resulted in attenuation of phenotypes normally observed in MMTV-Wnt1 glands including hyperbranching and increased progenitor and basal cell populations. Even though Wnt5a could antagonize Wnt/β-catenin signaling in primary mammary epithelial cells in culture, reduced Wnt/β-catenin signaling was not detected in non-tumor MMTV-Wnt1;Wnt5a tissue in vivo. The data demonstrate that Wnt5a suppresses tumor formation and promotes a phenotypic shift in MMTV-Wnt1 tumors.

Dietary stearic acid leads to a reduction of visceral adipose tissue in athymic nude mice

Stearic acid (C18:0) is a long chain dietary saturated fatty acid that has been shown to reduce metastatic tumor burden. Based on preliminary observations and the growing evidence that visceral fat is related to metastasis and decreased survival, we hypothesized that dietary stearic acid may reduce visceral fat. Athymic nude mice, which are used in models of human breast cancer metastasis, were fed a stearic acid, linoleic acid (safflower oil), or oleic acid (corn oil) enriched diet or a low fat diet ad libitum. Total body weight did not differ significantly between dietary groups over the course of the experiment. However visceral fat was reduced by ∼70% in the stearic acid fed group compared to other diets. In contrast total body fat was only slightly reduced in the stearic acid diet fed mice when measured by dual-energy x-ray absorptiometry and quantitative magnetic resonance. Lean body mass was increased in the stearic acid fed group compared to all other groups by dual-energy x-ray absorptiometry. Dietary stearic acid significantly reduced serum glucose compared to all other diets and increased monocyte chemotactic protein-1 (MCP-1) compared to the low fat control. The low fat control diet had increased serum leptin compared to all other diets. To investigate possible mechanisms whereby stearic acid reduced visceral fat we used 3T3L1 fibroblasts/preadipocytes. Stearic acid had no direct effects on the process of differentiation or on the viability of mature adipocytes. However, unlike oleic acid and linoleic acid, stearic acid caused increased apoptosis (programmed cell death) and cytotoxicity in preadipocytes. The apoptosis was, at least in part, due to increased caspase-3 activity and was associated with decreased cellular inhibitor of apoptosis protein-2 (cIAP2) and increased Bax gene expression. In conclusion, dietary stearic acid leads to dramatically reduced visceral fat likely by causing the apoptosis of preadipocytes.

Assessment of erlotinib as adjuvant chemoprevention in high-risk head and neck cancer patients

PURPOSE

To determine the tolerability and efficacy of long-term treatment with erlotinib for head and neck squamous cell carcinoma after salvage surgery.

METHODS

An open-label study was conducted of 150 mg of daily erlotinib for 12 months in patients who completed definitive surgical therapy for recurrent head and neck squamous cell carcinoma. The primary outcome measures were tolerability of prolonged erlotinib therapy and disease-free survival and overall survival at 1 and 2 years.

RESULTS

Thirty-one patients were enrolled onto this study. Mean duration of erlotinib therapy was 5 months (range 2-374 days), with 8 patients completing the full 12-month course of erlotinib. Of the remaining patients, 8 discontinued therapy as a result of recurrence, 10 for medical or surgical complications deemed unrelated to the study medication, and 3 for drug-related toxicities. There were 25 grade 3 adverse events; 4 were classified as possibly related to study medication. The most common adverse events included acneiform rash (n = 26 patients), fatigue (n = 22), and diarrhea (n = 22). Overall survival was 61 % at 1 year and 56 % at 2 years. Disease-free survival was 54 % at 1 year and 45 % at 2 years. Mean time to recurrence (n = 16) was 8.7 months.

CONCLUSIONS

Long-term erlotinib is safe and demonstrates some potential survival benefit compared to historical controls. However, despite the absence of grade 3/4 adverse events attributable to the drug, tolerance of long-term erlotinib was a significant barrier to completion of a 12-month course of therapy.

Return of hunger following a relatively high carbohydrate breakfast is associated with earlier recorded glucose peak and nadir

The aim of this study is to test the hypothesis that a breakfast meal with high carbohydrate/low fat results in an earlier increase in postprandial glucose and insulin, a greater decrease below baseline in postprandial glucose, and an earlier return of appetite, compared with a low carbohydrate/high fat meal. Overweight but otherwise healthy adults (n = 64) were maintained on one of two eucaloric diets: high carbohydrate/low fat (HC/LF; 55:27:18% kcals from carbohydrate:fat:protein) versus low carbohydrate/high fat (LC/HF; 43:39:18% kcals from carbohydrate:fat:protein). After 4 weeks of acclimation to the diets, participants underwent a meal test during which circulating glucose and insulin and self-reported hunger and fullness, were measured before and after consumption of breakfast from their assigned diets. The LC/HF meal resulted in a later time at the highest and lowest recorded glucose, higher glucose concentrations at 3 and 4 hours post meal, and lower insulin incremental area under the curve. Participants consuming the LC/HF meal reported lower appetite 3 and 4 hours following the meal, a response that was associated with the timing of the highest and lowest recorded glucose. Modest increases in meal carbohydrate content at the expense of fat content may facilitate weight gain over the long-term by contributing to an earlier rise and fall of postprandial glucose concentrations and an earlier return of appetite.

Hardware removal after osseous free flap reconstruction

OBJECTIVE

Identifying risk factors for hardware removal in patients undergoing mandibular reconstruction with vascularized osseous free flaps remains a challenge. The purpose of this study is to identify potential risk factors, including osteocutaneous radial forearm versus fibular flap, for need for removal and to describe the fate of implanted hardware.

STUDY DESIGN

Case series with chart review Setting Academic tertiary care medical center.

SUBJECTS AND METHODS

Two hundred thirteen patients undergoing 227 vascularized osseous mandibular reconstructions between the years 2004 and 2012. Data were compiled through a manual chart review, and patients incurring hardware removals were identified.

RESULTS

Thirty-four of 213 evaluable vascularized osseous free flaps (16%) underwent surgical removal of hardware. The average length of time to removal was 16.2 months (median 10 months), with the majority of removals occurring within the first year. Osteocutaneous radial forearm free flaps (OCRFFF) incurred a slightly higher percentage of hardware removals (9.9%) compared to fibula flaps (6.1%). Partial removal was performed in 8 of 34 cases, and approximately 38% of these required additional surgery for removal.

CONCLUSION

Hardware removal was associated with continued tobacco use after mandibular reconstruction (P = .03). Removal of the supporting hardware most commonly occurs from infection or exposure in the first year. In the majority of cases the bone is well healed and the problem resolves with removal.

Apolipoprotein E gene polymorphism influences aggressive behavior in prostate cancer cells by deregulating cholesterol homeostasis

High circulating cholesterol and its deregulated homeostasis may facilitate prostate cancer progression. Genetic polymorphism in Apolipoprotein (Apo) E, a key cholesterol regulatory protein may effect changes in systemic cholesterol levels. In this investigation, we determined whether variants of the Apo E gene can trigger defective intracellular cholesterol efflux, which could promote aggressive prostate cancer. ApoE genotypes of weakly (non-aggressive), moderate and highly tumorigenic (aggressive) prostate cancer cell lines were characterized, and we explored whether the ApoE variants were associated with tumor aggressiveness generated by intra cellular cholesterol imbalance, using the expression of caveolin-1 (cav-1), a pro-malignancy surrogate of cholesterol overload. Restriction isotyping of ApoE isoforms revealed that the non-aggressive cell lines carried ApoE ε3/ε3 or ε3/ε4 alleles, while the aggressive cell lines carried the Apoε2/ε4 alleles. Our data suggest a contrast between the non-aggressive and the aggressive prostate cancer cell lines in the pattern of cholesterol efflux and cav-1 expression. Our exploratory results suggest a relationship between prostate aggressiveness, ApoE isoforms and cholesterol imbalance. Further investigation of this relationship may elucidate the molecular basis for considering cholesterol as a risk factor of aggressive prostate tumors, and underscore the potential of the dysfunctional ApoE2/E4 isoform as a biomarker of aggressive disease.

Abstract 5299: Evaluation of apolipoprotein E polymorphism on the aggressive potential of prostate cancer cell lines

Introduction: Defective cholesterol-modulating apolipoprotein E (ApoE) isoforms could exacerbate prostatic neoplasia. Recent evidence strongly suggests that specific genetic variants of ApoE control peripheral tissue cholesterol efflux. Defects in ApoE may result in reduced prostate cancer cell cholesterol efflux and enriched concentrations of cholesterol in membranes by reducing clearance. Membrane-rich cholesterol could potentially activate cancer-driven signaling processes.

Objective: To determine the relevance of specific ApoE phenotypes as risk factors of aggressive prostate cancer based on their influence on reverse cholesterol transport.

Methods: We evaluated ApoE genotypes of the weakly tumorigenic or nonaggressive prostate cancer cell lines (LNCaP and MDA PCA 2b), and the moderate and highly tumorigenic or aggressive prostate cancer cell lines (PC-3 and DU-145). We examined whether ApoE2/E4 variants were associated with tumor aggressiveness via the expression of caveolin-1(cav-1), a cholesterol-regulated pro-carcinogenic gene.

Results: We observed that the nonaggressive prostate cancer cell lines carried either the Apo ε3/ε3 or ε3/ε4 alleles, while the aggressive prostate cancer cell lines carried the Apo ε2/ε4 alleles. Our results showed a two-fold increase in the expression of cav-1 in the aggressive cell lines, as opposed to the nonaggressive ones. There was a significantly (p&lt;0.01) greater cholesterol efflux from the nonaggressive cells lines compared to the aggressive cells. Also, the aggressive cell lines retained and localized more cholesterol in their membranes as opposed to the less aggressive cell lines.

Conclusions: These results suggest an association between cholesterol status and the aggressive potential of prostate cancer cells. It also highlights the need for further investigation into whether ApoE2/E4 is the dysfunctional phenotype, and whether it has the potential as a biomarker of aggressive prostate cancer.

GRANT SUPPORT: NIH R25CA047888

Citation Format: Godwin O. Ifere, Wendy Demark-Wahnefried, Renee Desmond, Tim R. Nagy. Evaluation of apolipoprotein E polymorphism on the aggressive potential of prostate cancer cell lines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5299. doi:10.1158/1538-7445.AM2013-5299

Phase 1 study of erlotinib plus radiation therapy in patients with advanced cutaneous squamous cell carcinoma

PURPOSE

To assess the toxicity profile of erlotinib therapy combined with postoperative adjuvant radiation therapy in patients with advanced cutaneous squamous cell carcinoma.

METHODS AND MATERIALS

This was a single-arm, prospective, phase 1 open-label study of erlotinib with radiation therapy to treat 15 patients with advanced cutaneous head-and-neck squamous cell carcinoma. Toxicity data were summarized, and survival was analyzed with the Kaplan-Meier method.

RESULTS

The majority of patients were male (87%) and presented with T4 disease (93%). The most common toxicity attributed to erlotinib was a grade 2-3 dermatologic reaction occurring in 100% of the patients, followed by mucositis (87%). Diarrhea occurred in 20% of the patients. The 2-year recurrence rate was 26.7%, and mean time to cancer recurrence was 10.5 months. Two-year overall survival was 65%, and disease-free survival was 60%.

CONCLUSIONS

Erlotinib and radiation therapy had an acceptable toxicity profile in patients with advanced cutaneous squamous cell carcinoma. The disease-free survival in this cohort was comparable to that in historical controls.

Chronic oral exposure to bisphenol A results in a nonmonotonic dose response in mammary carcinogenesis and metastasis in MMTV-erbB2 mice

BACKGROUND

Bisphenol A (BPA) is a synthetic compound used to produce plastics and epoxy resins. BPA can leach from these products in appreciable amounts, resulting in nearly ubiquitous daily exposure to humans. Whether BPA is harmful to humans, especially when administered orally in concentrations relevant to humans, is a topic of debate.

OBJECTIVES

In this study, we investigated the role of chronic oral exposure to BPA during adulthood on mammary carcinogenesis by using a transgenic mouse model that spontaneously develops tumors through overexpression of wild-type erbB2 [mouse mammary tumor virus (MMTV)-erbB2].

METHODS

MMTV-erbB2 mice were exposed to 0, 2.5, 25, 250, or 2,500 µg BPA/L drinking water from 56 until 112 days of age (for mechanism of action) or 252 days of age (for tumorigenesis). Cellular and molecular mechanisms of BPA action in the mammary gland were investigated via immunohistochemistry and immunoblotting.

RESULTS

Only low doses of BPA significantly decreased tumor latency and increased tumor multiplicity, tumor burden, and the incidence of metastasis. All BPA doses significantly increased the cell proliferation index, but only the higher doses also increased the apoptotic index in the mammary gland. At the molecular level, 25 µg BPA/L, but not 2,500 µg BPA/L, increased phosphorylation of erbB2, erbB3, insulin-like growth factor 1 receptor, and Akt in the mammary gland.

DISCUSSION

Low, but not high, BPA doses significantly accelerated mammary tumorigenesis and metastasis in MMTV-erbB2 mice. The combined ratio of cell proliferation and apoptosis indices and alterations in protein expression best predicted the ability of each dose of BPA to alter tumorigenesis in this model.

Meta-analysis of studies of a specific delivery mode for a modified-carbohydrate diet

BACKGROUND

Obesity is highly prevalent throughout the world. Although modified-carbohydrate diets (MCDs) comprise one popular approach, questions remain about their utility for weight loss. The objective of the present study was to conduct a meta-analysis of randomised controlled trials (RCTs) of a specific MCD compared with various control diets on weight loss.

METHODS

Data from four RCTs (three obtained from the sponsor and one indentified through literature searches) were included. Intent-to-treat analyses were conducted using multiple imputation to handle missing data, where possible. Because inter-study heterogeneity was demonstrated with fixed-effects meta-analysis, a random-effects meta-analysis also was conducted.

RESULTS

When considered separately, all four studies showed greater reduction in body weight with the MCD compared to control diets at 12-week follow-up; the results at 24 weeks (available for three of the studies) were not as consistent. Results for body mass index (BMI) were similar. Greater reductions in waist circumference with the MCD were seen at either time point in only one study. When fixed-effects meta-analysis was applied, significantly greater reductions in weight, BMI and waist circumference with the MCD at both 12 weeks (1.66 kg, 0.53 kg m(-2) and 1.02 cm, respectively) and 24 weeks (1.20 kg, 0.43 kg m(-2) and 0.69 cm, respectively) were evident. Random-effects meta-analysis revealed similar results; however, the 24-week difference for a reduction in waist circumference was no longer statistically significant.

CONCLUSIONS

Meta-analysis of individual RCT results demonstrated consistent benefits of this MCD compared to control diets on weight loss up to 24 weeks and waist circumference up to 12 weeks.

Behavioral transitions and weight change patterns within the PREMIER trial

Little is known about the transition in behaviors from short-term weight loss to maintenance of weight loss. We wanted to determine how short-term and long-term weight loss and patterns of weight change were associated with intervention behavioral targets. This analysis includes overweight/obese participants in active treatment (n = 507) from the previously published PREMIER trial, an 18-month, multicomponent lifestyle intervention for blood pressure reduction, including 33 intervention sessions and recommendations to self-monitor food intake and physical activity daily. Associations between behaviors (attendance, recorded days/week of physical activity, food records/week) and weight loss of ≥5% at 6 and 18 months were examined using logistic regression. We characterized the sample using 5 weight change categories (weight gained, weight stable, weight loss then relapse, late weight loss, and weight loss then maintenance) and analyzed adherence to the behaviors for each category, comparing means with ANOVA. Participants lost an average of 5.3 ± 5.6 kg at 6 months and 4.0 ± 6.7 kg (4.96% of body weight) by 18 months. Higher levels of attendance, food record completion, and recorded days/week of physical activity were associated with increasing odds of achieving 5% weight loss. All weight change groups had declines in the behaviors over time; however, compared to the other four groups, the weight loss/maintenance group (n = 154) had statistically less significant decline in number of food records/week (48%), recorded days/week of physical activity (41.7%), and intervention sessions attended (12.8%) through 18 months. Behaviors associated with short-term weight loss continue to be associated with long-term weight loss, albeit at lower frequencies. Minimizing the decline in these behaviors may be important in achieving long-term weight loss.

Outcomes for Total Glossectomy vs Laryngoglossectomy

Objective: Compare functional and survival outcomes for patients undergoing total glossectomy (TG) or total glossectomy plus laryngopharyngectomy (TGLP) for advanced squamous cell carcinoma (SCC) of the tongue.

Method: A retrospective review was undertaken of all patients undergoing TG or TGLP at an academic tertiary referral center between 2002 and 2010. There were 30 included patients (20 TG, 10 TGLP). Outcomes included tumor recurrence, disease-free survival and functional data (swallowing, gastrostomy tube dependence, speech, airway).

Results: Mean patient age was 56 years with a male predominance (90%). Compared with TG, TGLP was more commonly performed for recurrent tumors ( P = .06). Perineural invasion and extracapsular extension occurred more commonly for TGLP patients (80% vs 50%, P = .12). There was a trend toward increased tumor recurrence in the TG group (61% vs 40%, P = .43). Twelve month disease free survival was 40% (TG) vs 50% (TGLP). Functionally, more TG patients were totally gastrostomy tube dependent (70% vs 30%, P = .04), and 50% of TG patients were also tracheostomy dependent. Intelligible speech was achieved by 30% TG and 10% TGLP patients ( P = .68).

Conclusion: Patients undergoing TGLP had similar functional and survival outcomes to patients undergoing TG despite more locally advanced disease with greater adverse pathological features. Positive or close margins for TG occurred most commonly at the inferior resection margin which could explain why TGLP for advanced tongue SCC may improve local disease control.

Fruit and vegetable pricing by demographic factors in the Birmingham, Alabama, metropolitan area, 2004-2005

INTRODUCTION

Fruit and vegetable cost may influence consumption. Because the contextual environment influences food outlet type and availability, we wanted to determine whether neighborhood demographics were associated with prices of fruits and vegetables.

METHODS

We surveyed 44 grocery stores in the Birmingham, Alabama, metropolitan area to determine prices of 20 fruits and vegetables. Stores were geocoded and linked to the corresponding Census 2000 block group to obtain data for the independent variables - percentage African American, percentage with at least a high school diploma, and percentage of households below the poverty level. We conducted multiple linear regressions to estimate these predictors for each fruit and vegetable's mean price per serving during 2 seasons (fall/winter 2004, spring/summer 2005).

RESULTS

In the fall, we found no significant relationships between the predictors and prices of any fruits and vegetables in the survey. In the spring, the percentage who had at least a high school diploma was a predictor of price per serving for potatoes (beta = 0.001, P = .046).

CONCLUSION

Neighborhood demographics have little consistent influence on fruit and vegetable prices in Birmingham, Alabama, which may be a function of grocery store density, transportation patterns, and shopping patterns. The regional setting of the food environment has implications for food availability, variety, and price.

Expression of toll-like receptor-9 is increased in poorly differentiated prostate tumors

BACKGROUND

Toll-like receptor-9 (TLR9) is a cellular receptor for bacterial and vertebrate DNA. In addition to cells of the immune system, it is also expressed in various human cancer cell lines, including prostate cancer. We demonstrated previously that synthetic TLR9 ligands induce matrix metalloproteinase-13-mediated invasion in TLR9-expressing prostate cancer cells in vitro. Other studies have suggested possible sex steroid regulation of the function of the various TLRs. The role of TLR9 in the pathophysiology of prostate or any cancer is, however, unknown.

METHODS

Expression of TLR9, androgen receptor (AR), or the estrogen receptors alpha (ERalpha) and beta (ERbeta) were studied with immunohistochemistry in prostate cancer (n = 62) and benign prostatic hyperplasia (n = 45) specimens. TLR9 staining scores were compared with tumor stage, Gleason score, prostate-specific antigen (PSA) concentrations before tissue sampling and with the staining scores of AR, ERalpha, and ERbeta.

RESULTS

TLR9 expression was statistically significantly increased in prostate cancer epithelium and stroma, as compared with the same cellular compartments in benign hyperplasia. Significantly increased (P = 0.04) TLR9 expression was detected in cancers with high Gleason score (>7, n = 23), as compared with lower Gleason scores (< or =7, n = 39). No statistically significant associations were detected between TLR9 expression scores and PSA concentrations or tumor staging. Prostate adenocarcinoma cells were all positive for TLR9, AR, and ERbeta but negative for ERalpha expression. In cancer stroma cells, increased TLR9 expression was associated with increased ERalpha expression.

CONCLUSIONS

Expression of TLR9 is increased in prostate cancer specimens, especially in the most poorly differentiated forms.

Parametric modeling of localized melanoma prognosis and outcome

This investigation explored the most suitable parametric model for melanoma prognosis and compared it with the Cox model. Cox-Snell residuals and survival function plots were applied to assess whether the generalized gamma (GG) model was the best-fit parametric model for the data. The GG model is a powerful alternative to the Cox model in prognostic modeling. The GG model offers an advantage of explicit and flexible individualized hazard functions over the Cox model and provides a clinically useful risk assessment over time to aid clinicians in formulating patient treatment, follow-up plans, and clinical trial design and analysis.

Abstract 2878: Dietary stearate inhibits tumor development and tumor burden in the N-nitroso-N-methylurea (NMU) rat breast cancer carcinogen model

The goal of the present study was to test the effectiveness of dietary stearate at inhibiting breast cancer development in a carcinogen induced breast cancer model. Three diets were used; a 17% stearate diet, the key being that highly purified stearate was added directly to the diet, a linoleate diet (SF) containing 17% safflower oil as the source of linoleate and a low fat control diet (LF) with a reduced amount of fat (5%) from corn oil. All three diets had adequate essential fatty acids. These 3 diets were initiated 1 week prior to the rats receiving NMU and followed out 100 days. There was no difference in the weight of the rats among groups throughout the study. Approximately 40% fewer animals on the stearate and safflower diets developed palpable tumors compared to the LF (n=30-35 animals/diet; p&lt;0.05). No difference was observed among the three diets as to the time for first tumor appearance. Stearate decreased the average number of tumors per rat compared to the LF (n=30-35 animals per diet; p&lt;0.05) and had less tumors per rat than the SF although this was not statistically significant. Stearate also significantly reduced tumor burden as defined by tumor weight by ∼50% compared to LF and SF (p&lt;0.001) and large tumors compared to the LF (∼47% reduction in tumors over 0.25 g, p= 0.02). In those rats that did develop tumors, the stearate diet group had a similar number of adenocarcinomas compared to other diets; however the stearate and SF groups had lower numbers of DCIS/microinvasive disease as compared to the LF. The dietary groups tended to have similar numbers of the other precursor lesions classified although the dietary stearate group had the least number of “tubular adenomas”. Dietary stearate may be useful as an alternative/complementary therapy or preventative agent against breast cancer.

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 2878.

The safety of flavocoxid, a medical food, in the dietary management of knee osteoarthritis

This study was designed to determine the safety of a medical food, flavocoxid, a proprietary blend of free-B ring flavonoids and flavans from the root of Scutellaria baicalensis (Chinese skullcap) and the bark of Acacia catechu in the dietary management of knee osteoarthritis. The 12-week, randomized, double-blind, placebo-controlled trial in an academic medical center enrolled 59 patients with moderate osteoarthritis of at least one knee who were recruited who were classified as having "below average" to "a moderately above average cardiovascular risk" with a Framingham-based scoring tool. Subjects were randomized to flavocoxid 250 mg twice a day versus identical placebo. Safety measures, including recording of adverse events, incidence of serious adverse events, and results of routine laboratory values, were compared between the two groups. There were no major differences in the baseline demographic characteristics of the placebo and flavocoxid groups. With one exception no significant differences were found between the two groups with respect to adverse events by body system, blood pressure, or laboratory values. There was a significantly higher incidence of upper respiratory adverse events in the placebo group (35.4% vs. 5.8%, P = .0003). There were no intra- or inter-group differences in any of the laboratory parameters from study baseline to completion. Thus, flavocoxid is safe when used in a population with "below average" to "moderately above average cardiovascular risk" compared to placebo.

Gender Differences in the Association between Sleep Duration and Body Composition: The Cardia Study

Sleep duration has been inversely associated with body mass index (BMI). We examined the relationship between self-reported sleep duration and BMI, waist circumference, and percent body fat in Black and White individuals from the CARDIA study. Box-Tidwell regression models were adjusted for age and race (Model 1), additional lifestyle and demographic variables (Model 2), and physical activity (Model 3). There were significant interactions between sleep and gender for the main outcome variables. In men, there was a trend for an inverse relationship between reported sleep duration and BMI in Model 2 (beta = -0.20, P = .053) but not model 3 (beta = -0.139, P = .191). In women, inverse relationships were observed between sleep duration and BMI (beta = -0.294, P = .005) and waist circumference (beta = -0.442, P = .059), in Model 2. These associations became nonsignificant in model 3 (BMI: beta = -0.172, P = .084; waist circumference: beta = -0.161, P = .474). Our results are consistent with previous findings that sleep is associated with BMI and other body composition variables. However, the relationship between self-reported sleep duration and body composition may be stronger in women than in men.

Cognitive performance and plasma levels of homocysteine, vitamin B12, folate and lipids in patients with Alzheimer disease

BACKGROUND

Conflicting results have been reported on the association of plasma total homocysteine (tHcy) and cholesterol levels in Alzheimer disease (AD). The objective of this study was to determine the relationship between cognitive performance and plasma levels of tHcy and its biological determinants folate and vitamin B(12), and lipids in clinically diagnosed AD patients.

METHODS

A cross-sectional database review was performed on two separate groups of patients (n = 191). Mini-Mental State Exam (MMSE) scores, plasma levels of tHcy, vitamin B(12), folate, cholesterol, and triglycerides were analyzed.

RESULTS

The MMSE scores were inversely correlated with age, plasma levels of tHcy and LDL cholesterol. However, only the inverse relationship between MMSE scores and LDL cholesterol levels persisted after adjustment for age, sex, and status of statin treatment. Plasma tHcy levels increased significantly with age and were inversely related to vitamin B(12) and folate levels, which modified the relationship between MMSE scores and plasma tHcy levels.

CONCLUSIONS

The plasma tHcy levels appeared to relate more to aging than to cognition. Cognitive performance was inversely associated with plasma LDL cholesterol levels in AD patients. Our findings provide further evidence that high LDL cholesterol levels may play a role in the pathogenesis of AD.

Toll-like receptor-9 expression is inversely correlated with estrogen receptor status in breast cancer

Toll-like receptor 9 (TLR9) recognizes microbial and vertebrate DNA. We previously demonstrated TLR9 expression in human breast cancer cell lines and showed that TLR9 ligands stimulate their in vitro invasion. The aim of this study was to characterize TLR9 expression in clinical breast cancer specimens. Immunohistochemical staining intensity was compared with known baseline prognostic factors and distant metastasis-free survival. TLR9 expression was detected in 98% of the tumors studied (n = 141). The mean TLR9 staining intensity was higher in ER- than in the highly ER+ breast cancers (p = 0.039). High-grade tumors had significantly increased TLR9 expression (p = 0.027) compared with lower-grade tumors. The highest TLR9 expression was detected in the mucinous and the lowest in the tubular breast cancers (p = 0.034). Distant metastasis-free survival was higher in the lower TLR9-expressing half of the cohort than in the higher TLR9-expressing group (p = 0.118). TLR9 expression did not correlate with menopausal, PgR or Her2 status, patient age, tumor proliferative or invasive characteristics.

Baseline inflammatory markers do not modulate the lipid response to weight loss

Recent studies have found that baseline inflammatory status affected the response of the lipid profile to diet intervention. The goal of this study was to determine whether baseline inflammatory status, as reflected in C-reactive protein, interleukin 6, and tumor necrosis factor alpha, affected the lipid and insulin response to a weight loss intervention. A second goal was to determine whether inflammatory markers were related to traditional metabolic risk factors, such as lipids and insulin, in our sample of 190 overweight (body mass index, 27-30 kg/m2) premenopausal women. Body composition, fat distribution, serum lipids, insulin sensitivity (Si), and markers of inflammation were assessed at baseline and after weight loss to body mass index<25 kg/m2. All measurements were taken after a 4-week period of weight maintenance. Mixed-model, repeated-measures analysis was used to determine whether the interaction of baseline inflammatory status and time was significant in determining the changes in metabolic risk factors (Si and lipids) with weight loss. Weight loss was associated with significant reductions in total cholesterol, low-density lipoprotein cholesterol, triglycerides, and insulin, and increases in high-density lipoprotein cholesterol and Si. Triglycerides were higher (P=.054) and Si lower (P=.057) with increasing C-reactive protein tertile. The interaction of baseline inflammatory status and time was not significant for any outcome variable of interest. These results do not support the hypothesis that baseline inflammatory status affects the lipid and insulin response to a weight loss intervention. However, in these young, healthy women, weight loss had a beneficial impact on both inflammatory status and risk factors for chronic metabolic disease.

Health-seeking behaviors and sexually transmitted diseases among adolescents attending an urban pediatric emergency department

INTRODUCTION

Adolescents are often seen in Emergency departments (ED) for urgent care. Rates of treatable sexually transmitted diseases (Neisseria gonorrhoeae and Chlamydia trachomatis) are highest in this age group. This study examines the prevalence of these sexually transmitted diseases (STDs) and the health seeking characteristics of adolescents presenting to an urban pediatric ED.

METHODS

Participants were enrolled between January 2000 and July 2004. Urine specimens (tested for the STDs) and a questionnaire data form (demographics and health seeking behaviors) were collected and scanned into a computer database, and results were merged for analysis. Prevalence rates were calculated for gonorrheal and chlamydial infections.

RESULTS

A total of 1,621 participants were enrolled. Prevalence rates for C. trachomatis and N. gonorrhoeae were 9.8% (95% CI 8.6, 11.1) and 3.4% (95% CI 2.6,4.2), respectively. Test results did not differ significantly by race (p= 0.29). Reporting of a regular health care provider vs no regular provider did not significantly impact the likelihood of having a positive test result, 10.7% (95% CI 9.1, 12.4) vs 12.1% (95% CI 5.4, 18.8) (p=0.69). The prevalence of STDs was higher among uninsured (16.3, 95% CI 12.3, 20.3) and those participants covered by Medicaid (13.3, 95% CI 10.6, 16.1) compared to those reporting private insurance (6.0, 95% CI 4.2, 7.7).

CONCLUSION

This study confirms a high prevalence of treatable STDs among adolescents in an urban ED setting and provides information on frequency of ED usage and health-seeking behaviors among adolescents.

Variable selection in logistic regression for detecting SNP-SNP interactions: the rheumatoid arthritis example

Many complex disease traits are observed to be associated with single nucleotide polymorphism (SNP) interactions. In testing small-scale SNP-SNP interactions, variable selection procedures in logistic regressions are commonly used. The empirical evidence of variable selection for testing interactions in logistic regressions is limited. This simulation study was designed to compare nine variable selection procedures in logistic regressions for testing SNP-SNP interactions. Data on 10 SNPs were simulated for 400 and 1000 subjects (case/control ratio=1). The simulated model included one main effect and two 2-way interactions. The variable selection procedures included automatic selection (stepwise, forward and backward), common 2-step selection, AIC- and SC-based selection. The hierarchical rule effect, in which all main effects and lower order terms of the highest-order interaction term are included in the model regardless of their statistical significance, was also examined. We found that the stepwise variable selection without the hierarchical rule, which had reasonably high authentic (true positive) proportion and low noise (false positive) proportion, is a better method compared to other variable selection procedures. For testing interactions, the hierarchical rule effect was obvious. The procedure without the hierarchical rule requires fewer terms in testing interactions, so it can accommodate more SNPs than the procedure with the hierarchical rule. For testing interactions, the procedures without the hierarchical rule had higher authentic proportion and lower noise proportion compared with ones with the hierarchical rule. These variable selection procedures were also applied and compared in a rheumatoid arthritis study.

Relationship between metabolic function and skeletal muscle fatigue during a 90 s maximal isometric contraction

Little is known concerning the contributions of oxidative phosphorylation (OxPhos), anaerobic glycolytic rate (AnGly), maximum creatine kinase (CK) activity, and metabolic economy (ME) on fatigue resistance. The purpose of this study was to model fatigue using muscle tissue metabolic measures during a maximal short-duration isometric contraction. Muscle metabolic function was measured with [31P]-magnetic resonance spectroscopy (MRS) in 54 premenopausal women (age: 33.8+/-6.3 y) while they performed 100% isometric plantar flexions. Multiple regression analysis revealed that all metabolic variables were independent predictors of fatigue resistance after adjusting for maximum isometric force generated (R2=0.56). ME accounted for the largest portion (36%) of overall shared variance. OxPhos accounted for the most shared variance of the three energy systems. These results support previous findings that OxPhos, AnGly, CK, and ME all contribute to fatigue resistance over a short duration. Additionally, the continued activity of CK at the end of 90 s of maximal exercise lends support to the concept of a CK shuttle facilitating energy transfer within the mitochondria.

A randomized trial of metronidazole in asymptomatic bacterial vaginosis to prevent the acquisition of sexually transmitted diseases

OBJECTIVE

The purpose of this study was to determine whether treatment of bacterial vaginosis (BV) decreases the incidence of sexually transmitted diseases (STDs).

STUDY DESIGN

Women with asymptomatic BV were studied prospectively to determine the effect of treatment of BV for the prevention of STD. Women were assigned randomly to observation or treatment and prophylaxis with intravaginal metronidazole gel. Women were screened monthly for STDs.

RESULTS

Women who were assigned randomly to receive metronidazole gel had a significantly longer time to the development of STDs compared with women in the observation group (P = .02). The 6-month STD rate was 1.58 per person-year (95% CI, 1.29, 1.87) for women in the metronidazole gel group vs 2.29 per person-year (95% CI, 1.95, 2.63) for women in the observational group. The difference in STD rates was driven by a significant difference in the number of chlamydial infections (P = .013).

CONCLUSION

Treatment and twice-weekly prophylactic use of intravaginal metronidazole gel resulted in significantly fewer cases of chlamydia.

Serum macrophage inhibitory cytokine-1 concentrations correlate with the presence of prostate cancer bone metastases

Macrophage-inhibitory cytokine-1 (MIC-1) is a divergent member of the transforming growth factor beta superfamily. It is up-regulated by nonsteroidal anti-inflammatory drugs and is highly expressed in human prostate cancer leading to high serum MIC-1 concentrations with advanced disease. A role for MIC-1 has been implicated in the process of early bone formation, suggesting that it may also mediate sclerosis at the site of prostate cancer bone metastases. Consequently, the aim of this study was to retrospectively determine the relationship of serum MIC-1 concentration and other markers related to current and future prostate cancer bone metastasis in a cohort of 159 patients with prostate cancer. Serum markers included cross-linked carboxy-terminal telopeptide of type I collagen, prostate-specific antigen, and amino-terminal propeptide of type I procollagen (PINP). The mean values of all the biomarkers studied were significantly higher in patients with baseline bone metastases (BM+, n = 35), when compared with those without bone metastases (BM-, n = 124). In a multivariate logistic model, both MIC-1 and PINP independently predicted the presence of baseline bone metastasis. Based on receiver operator curve analysis, the best predictor for the presence of baseline bone metastasis was MIC-1, which was significantly better than carboxy-terminal telopeptide of type I collagen, prostate-specific antigen, and PINP. Patients who experienced bone relapse had significantly higher levels of baseline MIC-1 compared with patients who did not (1476.7 versus 988.4; P = 0.03). Current use of acetylsalicylic acid did not influence serum MIC-1 levels in this cohort. Although requiring validation prospectively, these results suggest that serum MIC-1 determination may be a valuable tool for the diagnosis of current and future bone metastases in patients with prostate cancer.

A three-dimensional assay for measurement of viral-induced oncolysis

Oncolytic viruses represent a novel cancer treatment strategy. Despite their promising preclinical data, however, corresponding clinical trials have disappointed. To aid preclinical analyses, we hypothesized that three-dimensional tumor cell clusters or spheroids might provide an assay system superior to conventional monolayer cell cultures. Spheroids show viral infection, replication and oncolytic patterns distinct from conventional monolayer assays. Therefore, viral tumor penetration and oncolysis measurements may be improved with such three-dimensional models. Also, preclinical analyses of oncolytic viruses frequently measure mitochondrial activity, but more accurate measures of oncolysis might involve quantitation of intracellular protein release. Therefore, we measured luciferase released from luciferase-expressing spheroids and found unique patterns that maintained consistency with various viruses and doses. The relative variations between viruses and doses may represent temporal differences in oncolysis dynamics. Analysis of five recombinant replicative adenoviruses with promise for clinical application showed that Ad5/3-Delta24 produced the most luciferase release 1 week after infection and achieved the earliest and highest peak luciferase release level. Ad5/3-Delta24 also effected the earliest subtotal spheroid cell death. These findings closely parallel monolayer oncolysis assays with these agents. Therefore, the luciferase-expressing tumor spheroid assay represents a promising three-dimensional model for preclinical analysis of replicative oncolytic agents.

Diet variety based on macronutrient intake and its relationship with body mass index

CONTEXT

Increased dietary variety has been associated with increased body weight; however, diet variety is not measured using a standardized methodology.

OBJECTIVE

We developed a new dietary variety score (DVS) based on food macronutrient content, and determined the relationship between DVS and measures of adiposity.

DESIGN

Cross-sectional, observation study.

SETTING

University of Alabama at Birmingham (UAB), EatRight Weight Management Program.

PATIENTS

Study subjects (n = 74) were former participants of UAB's EatRight Weight Management Program who completed the program at least 1 year ago.

MAIN OUTCOME MEASURES

Unique items from 4-day food records were converted to macronutrient categories using the diabetic exchange. Foods were categorized as a source of carbohydrate if containing > or = 5 g carbohydrate and > or = 20 calories; fat if containing > or = 5 g fat; protein if containing > or = 7 g protein. Height and weight were measured; BMI (kg/m2) was calculated. Dual energy X-ray absorptiometry measured body fat. Generalized linear modeling in SAS (Ver.9) determined relationships between adiposity and DVS.

RESULTS

On average, participants weighed 92.7 -/+ 30.9 kg (BMI = 32.5 kg/m2). Men and women's body fat were 37.4 -/+ 6.4% and 47.3 -/+ 6.4%, respectively. Separate linear regression models containing terms for sex and DVS showed significant relationships between macronutrient DVS and BMI. In a multivariate model controlling for each of the macronutrient DVS, BMI was not related to fat DVS, but was found to be positively related to protein DVS (beta = 0.87, P = .04). Sex modified the relationship between carbohydrate DVS and BMI, with an inverse relationship between BMI and carbohydrate DVS among women, and a positive relationship among men. Percent body and trunk fat were not related to DVS for either gender.

CONCLUSIONS

The new DVS, based on macronutrient content of foods, had significant associations with BMI. These dietary variety scores may provide another way to evaluate the impact of consuming a variety of food types on energy intake and BMI.