Machine learning to predict myocardial injury and death after non-cardiac surgery

Myocardial injury due to ischaemia within 30 days of non-cardiac surgery is prognostically relevant. We aimed to determine the discrimination, calibration, accuracy, sensitivity and specificity of single-layer and multiple-layer neural networks for myocardial injury and death within 30 postoperative days. We analysed data from 24,589 participants in the Vascular Events in Non-cardiac Surgery Patients Cohort Evaluation study. Validation was performed on a randomly selected subset of the study population. Discrimination for myocardial injury by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.70 (0.69-0.72) vs. 0.71 (0.70-0.73) with variables available before surgical referral, p < 0.001; 0.73 (0.72-0.75) vs. 0.75 (0.74-0.76) with additional variables available on admission, but before surgery, p < 0.001; and 0.76 (0.75-0.77) vs. 0.77 (0.76-0.78) with the addition of subsequent variables, p < 0.001. Discrimination for death by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.71 (0.66-0.76) vs. 0.74 (0.71-0.77) with variables available before surgical referral, p = 0.04; 0.78 (0.73-0.82) vs. 0.83 (0.79-0.86) with additional variables available on admission but before surgery, p = 0.01; and 0.87 (0.83-0.89) vs. 0.87 (0.85-0.90) with the addition of subsequent variables, p = 0.52. The accuracy of the multiple-layer model for myocardial injury and death with all variables was 70% and 89%, respectively.

P1082Validation of cardiologist-created, audiovisual education delivered via smart devices while awaiting outpatient consultation: optimising atrial fibrillation management through shared decision making

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and its management requires numerous complex decisions shared between patients and their treating cardiologist. However, apart from the restricted time within each consultation, there is limited opportunity to educate patients for optimising the shared decision making that can subsequently impact the effectiveness of their management. A relatively untested opportunity for education is while patients are awaiting cardiology outpatient consultation. This could be in part due to the lack of availability of educational material that is suitable for both patient management and satisfaction, or that the development process is often too time or resource-heavy for the respective cardiologist. Audiovisual educational material created by the cardiologist could potentially be better received by patients while awaiting outpatient consultation.

Purpose

To evaluate the effectiveness and efficiency of a cardiologist-created, audiovisual educational module in facilitating shared decision making for the management of AF. 

Methods

The cardiologist developed 4 educational videos on AF that aimed to enhance patient knowledge for the following topics: (1) What is AF?, (2) AF Management, (3) Stroke risk and anticoagulation, and (4) Lifestyle modification. The videos were then combined into a web-based audiovisual module where they were viewed sequentially and accompanied by questions gauging patient experience. The module was delivered using Quick Response (QR) code scanning on smart devices to 115 patients with AF in the waiting room prior to cardiologist consultation. Feedback was recorded on 5-point Likert Scales or Visual Analogue Scales (VAS).

Results

Each video took an average of 3 minutes and 42 seconds for the cardiologist to record using minimal resources comprising of a smart device and a desktop computer for the cardiologist-narrated audiovisual presentation.  On the Likert scales, 96.4% of responders were "very satisfied" with the individual videos, with only 0.8% of responses conveying dissatisfaction. The VAS ratings (0-100) were: Improving peri-consultation anxiety 89.93 +/- 9.62; Improving the patient’s decision making 85.86 +/- 16.71; Improving likelihood of long-term treatment adherence 87.30 +/- 12.27; Beneficial effect on patient experience from the cardiologist’s narration in the educational module 86.51 +/- 14.86.

Conclusions

The audiovisual educational module was created by the cardiologist in a time and resource-efficient manner. Patients responded positively to both the cardiologist’s narration and the content of the AF-specific videos. This approach was not only a beneficial utilisation of the patient’s waiting time prior to outpatient consultation, but also a simple, time and resource-efficient way that cardiologists themselves can provide patient education, and by extension optimise shared decision making in the management of AF.

P571Accuracy of a machine learning program to correctly triage incoming SMS text replies from a successful cardiovascular SMS-based secondary prevention program

Background

Cardiovascular SMS text programs are effective alternate secondary prevention programs for cardiac risk factor reduction and can be delivered as one-way or two-way communication. However, people text back regularly, leading to staffing costs to monitor replies. If you could reduce the need for staff review by 60–70%, costs and scalability of text programs would substantially improve.

Purpose

To develop and assess accuracy of a machine-learning (ML) program to “triage” and identify texts requiring review/action.

Methods

We manually reviewed and classified all replies received from two “TEXT ME” cardiovascular secondary prevention programs. Simultaneously a ML model was developed to classify texts and determine those needing a reply (figure). Comparison of ML models included “Naïve Bayes”, “random forest decision trees”, and “gradient boosted trees”, along with comparison to “convolutional neural network” and “recurrent neural network” classification approaches. “Natural language programming” was evaluated however this presented challenges in relation to text content due to non-standard English grammar, frequent use of non-standard abbreviations, and spelling errors. The ML program was trained with 70% of the data-set and accuracy was tested with 30%.

Results

Manual review of 3118 text replies revealed that only one text was considered urgent, and only 21% required review/action: categorisation was not straight forward due to complexity of texts often containing more than one sentiment (table). The ML program was able to correctly classify 84% of texts into the designated 12 categories. The sensitivity for correctly identifing the need for health professional review was 94% (6.4% false negatives; 3.6% false positives); but with addition of “heuristics” (e.g. searching for specified keywords, question marks etc) sensitivity increased to 97% (2.9% false negatives; 7.3% false positives). Therefore, health professionals would only have to review 27% (true + false positives) of all text replies.

Table 1. SMS manual categorisation (n=3118) REVIEW REQUIRED Health Question/concern Admin request Request to STOP Ceased smoking SMS not delivered Urgent/ distress (13%) (4.5%) (3%) (0.8%) (0.4%) (0.03%) NO REVIEW REQUIRED General statement Statement of thanks Reporting good health Blank message Unrelated/ accidental Emoticon only (33%) (23%) (11%) (6%) (4%) (2.4%)

Figure 1. Development process

Conclusions

The ML program has high sensitivity identifying text replies requiring health professional input and a low false negative rate indicating few messages needing response would be missed. Thus, introduction of the program could significantly reduce the workload of health professionals, leading to substantial improvements in scalability and capacity of text-based programs. The future implications for this technology are vast, including utilisation in other interactive mHealth interfaces and cardiovascular health “apps”.

Acknowledgement/Funding

National Heart Foundation Vanguard Grant; National Health and Medical Research Council Project Grant

A text message intervention to support women's physical and mental health after breast cancer treatments (EMPOWER-SMS): a randomised controlled trial protocol

Background

Breast cancer is the most common cancer diagnosed in women worldwide. In developed countries, 80–90% of women will survive five years after diagnosis but the transition from hospital-based care to health self-management and self-efficacy can be difficult. Text messaging programs offer a simple and proven way to provide support to people with chronic diseases. This study aims to test the effectiveness of a text message support program at improving women’s health self-efficacy, and physical and mental health outcomes after breast cancer treatments compared to usual care at 6-months and to understand the barriers and enablers to widespread implementation.

Methods

Single-blind randomised control trial (RCT; N = 160) comparing a text message support intervention to usual care in women with breast cancer (recruited from a large tertiary referral hospital in Sydney, Australia). The intervention group will receive a six-month text message support program, which consists of semi-personalised, supportive, lifestyle-focused text messages (4 messages/week) in addition to usual care. The control group will receive usual care without the text message program. Outcomes will be assessed at 6-months. The primary outcome is change in self-efficacy for managing chronic disease. Secondary outcomes include change in clinical outcomes (body mass index), lifestyle outcomes (physical activity levels, dietary behaviours), mood (depression and anxiety scales), quality of life, satisfaction with, and usefulness of the intervention. Analyses will be performed on the principle of intention-to-treat to examine differences between intervention and control groups.

Discussion

This study will test if a scalable and cost-effective text-messaging intervention is effective at improving women’s health self-efficacy, as well as physical and mental health outcomes. Moreover, this study will provide essential preliminary data to bolster a large multicentre RCT to helpsupport breast cancer survivors throughout recovery and beyond.

Trial registration

Australia New Zealand Clinical Trials Registry (ANZCTR) number ACTRN12618002020268, 17 December 2018

Effect of lifestyle focused text messaging on risk factor modification in patients with diabetes and coronary heart disease: A sub-analysis of the TEXT ME study

AIMS

There is potential to provide public health interventions through text messaging for patients with Type 2 diabetes mellitus (T2DM). Our objective was to ascertain if lifestyle focused text messaging addressing cardiovascular risk factors in patients with coronary heart disease (CHD) and T2DM, was more effective than usual care.

METHODS

This is a secondary analysis of the TEXT ME study, a randomised clinical trial of a 6-month text messaging intervention in patients with coronary heart disease. The measured outcomes include cholesterol, blood pressure (BP), body mass index (BMI), HbA1c, waist/hip circumference and smoking status. Our objective was to ascertain if lifestyle focused text messaging in patients with T2DM was more effective than usual care, and to determine if the intervention was more effective in patients with T2DM compared to those without.

RESULTS

229 participants in the TEXT ME study had T2DM (32%), 111 participants in the intervention group and 118 in the control group. At 6 months, the mean difference in systolic BP was -7.6 mmHg (95%CI -11.8, -3.37, p = 0.0003) and diastolic BP -3.7 mmHg (95%CI -6.12, -1.24, p = 0.0032). The mean difference in low density lipoprotein in the intervention arm, compared to the control arm, was -0.05 mmol/L (95%CI -0.27, 0.18, p = 0.813), and in triglycerides was -0.29 mmol/L (95%CI -0.59, 0.01, p = 0.035) respectively. The mean difference in BMI was -0.89 kg/m² (95%CI -2.74, 0.95, p < 0.0001) in the intervention group, waist circumference -3.98 cm (95%CI -8.57, 0.61, p < 0.0001) and hip circumference -3.26 cm (95%CI -7.67, 1.16, p = 0.0006). Intervention subjects with diabetes were less likely to be smokers at 6 months. The mean difference in HbA1c between the control and intervention group was not significant (p = 0.126). The intervention was as effective in patients with diabetes, compared to those without.

CONCLUSION

Among patients with coronary heart disease with T2DM, lifestyle-focused text messaging resulted in significant risk factor reduction.

Inaccurate risk perceptions contribute to treatment gaps in secondary prevention of cardiovascular disease

BACKGROUND

All patients with cardiovascular disease (CVD) are at high risk of recurrent events. Despite strong evidence, large treatment gaps exist in CVD secondary prevention. We hypothesise that patients' self-perception and general practitioner's (GP) assessment of future cardiovascular (CV) risk may influence secondary prevention behaviours.

AIM

To examine in patients with known CVD the perceived risk of future CV events and its relationship with use of secondary prevention medications and risk factor control.

METHODS

We examined patient and practitioner's perceived risk and its relationship with the uptake of secondary prevention recommendations in adults with CVD participating in the Australian Hypertension and Absolute Risk Study.

RESULTS

Among the 1453 participants, only 11% reported having a high absolute risk and 29% reported high relative risk of recurrent events. The GP categorised only 30% as having a 5-year risk ≥15%. After adjusting for covariates, hospitalisation within the preceding 12 months was the only significant predictor of patients' accurate risk perception. Conventional CV risk factors were predictive of the GP's risk estimates. Patients who accurately understood their risk reported higher smoking cessation rates (7 vs 3%, P = 0.003) and greater use of antiplatelet, blood pressure lowering therapy and statins (P ≤ 0.01). However, there was no relationship between GP's risk perception and secondary prevention treatments.

CONCLUSION

Both patients and GP have optimistic bias and underestimate the risk of future CV events. Patients' accurate self-perception, but not GP risk perception, was associated with improved secondary preventative behaviours. This suggests that helping patients to understand their risk may influence their motivation towards secondary prevention. Providing support to GP or programmes to help patients better understand their risks could have potential benefit on secondary prevention behaviours.

Cardiac assessment prior to non-cardiac surgery

BACKGROUND

Increasingly, patients undergoing non-cardiac surgery are older and have more comorbidities yet preoperative cardiac assessment appears haphazard and unsystematic. We hypothesised that patients at high cardiac risk were not receiving adequate cardiac assessment, and patients with low-cardiac risk were being over-investigated.

AIMS

To compare in a representative sample of patients undergoing non-cardiac surgery the use of cardiac investigations in patients at high and low preoperative cardiac risk.

METHODS

We examined cardiac assessment patterns prior to elective non-cardiac surgery in a representative sample of patients. Cardiac risk was calculated using the Revised Cardiac Risk Index.

RESULTS

Of 671 patients, 589 (88%) were low risk and 82 (12%) were high risk. We found that nearly 14% of low-risk and 45% of high-risk patients had investigations for coronary ischaemia prior to surgery. Vascular surgery had the highest rate of investigation (38%) and thoracic patients the lowest rate (14%). Whilst 78% of high-risk patients had coronary disease, only 46% were on beta-blockers, 49% on aspirin and 77% on statins. For current smokers (17.3% of cohort, n = 98), 60% were advised to quit pre-op.

CONCLUSIONS

Practice patterns varied across surgical sub-types with low-risk patients tending to be over-investigated and high-risk patients under-investigated. A more systemised approach to this large group of patients could improve clinical outcomes, and more judicious use of investigations could lower healthcare costs and increase efficiency in managing this cohort.

Clinical guidelines on hyperlipidaemia: recent developments, future challenges and the need for an Australian review

Large reductions in cardiovascular disease (CVD) mortality have been achieved over the last 50 years in developed countries. The health policies that have contributed so much to this success have largely been coordinated by means of expert guidelines for the management of the classic modifiable risk factors such as blood pressure, diabetes and blood lipids. National and international guidelines for lipid management have demonstrated a high degree of consistency between numerous sets of recommendations. It has been argued that some important components of the consensus that has been established over the past decade have been challenged by the latest guidelines of the American Heart Association - American College of Cardiologists (AHA-ACC). Clinicians can be reassured that continued reliance on extensive scientific evidence has reaffirmed the importance of lipid metabolism as a modifiable risk factor for atherosclerotic cardiovascular disease. On the other hand, the recent AHA-ACC guidelines suggest changes in the strategies by which metabolic risk factors may be modified. This small number of important changes should not be sensationalised because these differences usefully reflect the need for guidelines to evolve to accommodate different contexts and changing perspectives as well as emerging issues and new information for which clinical trial evidence is incomplete. This article will consider the recent policies and responses of national and supranational organisations on topics including components of CVD risk assessment, sources of CVD risk information and re-appraisal of lipid-lowering interventions. Timely review of Australian lipid management guidelines will require consideration of these issues because they are creating a new context within which new guidelines must evolve.

The influence of physical activity on vascular complications and mortality in patients with type 2 diabetes mellitus

AIMS

There is limited evidence regarding the association between physical activity and vascular complications, particularly microvascular disease, in patients with type 2 diabetes.

METHODS

From the 11 140 patients in the ADVANCE (Action in Diabetes and Vascular Disease: Preterax and Diamicron modified release Controlled Evaluation) trial, the effect of physical activity, categorized as none, mild, moderate or vigorous, and the number of sessions within a week, was examined in multivariable regression models adjusted for potential confounders. The study end-points were major cardiovascular events, microvascular complications and all-cause mortality.

RESULTS

Forty-six percent of participants reported undertaking moderate to vigorous physical activity for >15 min at least once in the previous week. During a median of 5 years of follow-up, 1031 patients died, 1147 experienced a major cardiovascular event and 1136 a microvascular event. Compared to patients who undertook no or mild physical activity, those reporting moderate to vigorous activity had a decreased risk of cardiovascular events (HR: 0.78, 95% CI: 0.69-0.88, p < 0.0001), microvascular events (HR: 0.85, 95% CI: 0.76-0.96, p = 0.010) and all-cause mortality (HR: 0.83, 95% CI: 0.73-0.94, p = 0.0044).

CONCLUSIONS

Moderate to vigorous, but not mild, physical activity is associated with a reduced incidence of cardiovascular events, microvascular complications and all-cause mortality in patients with type 2 diabetes.

Resting heart rate and the risk of death and cardiovascular complications in patients with type 2 diabetes mellitus

AIMS/HYPOTHESIS

An association between resting heart rate and mortality has been described in the general population and in patients with cardiovascular disease. There are, however, few data exploring this relationship in patients with type 2 diabetes mellitus. The current study addresses this issue.

METHODS

The relationship between baseline resting heart rate and all-cause mortality, cardiovascular death and major cardiovascular events (cardiovascular death, non-fatal myocardial infarction or non-fatal stroke) was examined in 11,140 patients who participated in the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) Study.

RESULTS

A higher resting heart rate was associated with a significantly increased risk of all-cause mortality (fully adjusted HR 1.15 per 10 bpm [95% CI 1.08, 1.21], p<0.001), cardiovascular death and major cardiovascular outcomes without adjustment and after adjusting for age and sex and multiple covariates. The increased risk associated with a higher baseline resting heart rate was most obvious in patients with previous macrovascular complications (fully adjusted HR for death 1.79 for upper [mean 91 bpm] vs lowest [mean 58 bpm] fifth of resting heart rate in this subgroup [95% CI 1.28, 2.50], p = .001).

CONCLUSIONS/INTERPRETATION

Among patients with type 2 diabetes, a higher resting heart rate is associated with an increased risk of death and cardiovascular complications. It remains unclear whether a higher heart rate directly mediates the increased risk or is a marker for other factors that determine a poor outcome.

Design and rationale of the tobacco, exercise and diet messages (TEXT ME) trial of a text message-based intervention for ongoing prevention of cardiovascular disease in people with coronary disease: a randomised controlled trial protocol

Background Although supporting lifestyle change is an effective way of preventing further events in people with cardiovascular disease, providing access to such interventions is a major challenge. This study aims to investigate whether simple reminders about behaviour change sent via mobile phone text message decrease cardiovascular risk. Methods and analysis Randomised controlled trial with 6 months of follow-up to evaluate the feasibility, acceptability and effect on cardiovascular risk of repeated lifestyle reminders sent via mobile phone text messages compared to usual care. A total of 720 patients with coronary artery disease will be randomised to either standard care or the TEXT ME intervention. The intervention group will receive multiple weekly text messages that provide information, motivation, support to quit smoking (if relevant) and recommendations for healthy diets and exercise. The primary end point is a change in plasma low-density lipoprotein cholesterol at 6 months. Secondary end points include a change in systolic blood pressure, smoking status, quality of life, medication adherence, waist circumference, physical activity levels, nutritional status and mood at 6 months. Process outcomes related to acceptability and feasibility of TEXT ME will also be collected. Ethics and dissemination Primary ethics approval was received from Western Sydney Local Health Network Human Research Ethics Committee-Westmead. Results will be disseminated via the usual scientific forums including peer-reviewed publications and presentations at international conferences. Clinical trials registration number ACTRN12611000161921.

The coronary CT angiography vision protocol: a prospective observational imaging cohort study in patients undergoing non-cardiac surgery

INTRODUCTION

At present, physicians have a limited ability to predict major cardiovascular complications after non-cardiac surgery and little is known about the anatomy of coronary arteries associated with perioperative myocardial infarction. We have initiated the Coronary CT Angiography (CTA) VISION Study to (1) establish the predictive value of coronary CTA for perioperative myocardial infarction and death and (2) describe the coronary anatomy of patients that have a perioperative myocardial infarction.

METHODS AND ANALYSIS

The Coronary CTA VISION Study is prospective observational study. Preoperative coronary CTA will be performed in 1000-1500 patients with a history of vascular disease or at least three cardiovascular risk factors who are undergoing major elective non-cardiac surgery. Serial troponin will be measured 6-12 h after surgery and daily for the first 3 days after surgery. Major vascular outcomes at 30 days and 1 year after surgery will be independently adjudicated.

ETHICS AND DISSEMINATION

Coronary CTA results in a measurable radiation exposure that is similar to a nuclear perfusion scan (10-12 mSV). Treating physicians will be blinded to the CTA results until 30 days after surgery in order to provide the most unbiased assessment of its prognostic capabilities. The only exception will be the presence of a left main stenosis >50%. This approach is supported by best available current evidence that, excluding left main disease, prophylatic revascularisation prior to non-cardiac surgery does not improve outcomes. An external safety and monitoring committee is overseeing the study and will review outcome data at regular intervals. Publications describing the results of the study will be submitted to major peer-reviewed journals and presented at international medical conferences.

Education and risk for acute myocardial infarction in 52 high, middle and low-income countries: INTERHEART case-control study

OBJECTIVE

To determine the effect of education and other measures of socioeconomic status (SES) on risk of acute myocardial infarction (AMI) in patients and controls from countries with diverse economic circumstances (high, middle, and low income countries).

DESIGN

Case-control study.

SETTING

52 countries from all inhabited regions of the world.

PARTICIPANTS

12242 cases and 14622 controls.

MAIN OUTCOME MEASURES

First non-fatal AMI.

RESULTS

SES was measured using education, family income, possessions in the household and occupation. Low levels of education (< or =8 years) were more common in cases compared to controls (45.0% and 38.1%; p<0.0001). The odds ratio (OR) for low education adjusted for age, sex and region was 1.56 (95% confidence interval 1.47 to 1.66). After further adjustment for psychosocial, lifestyle, other factors and mutually for other socioeconomic factors, the OR associated with education < or =8 years was 1.31 (1.20 to 1.44) (p<0.0001). Modifiable lifestyle factors (smoking, exercise, consumption of vegetables and fruits, alcohol and abdominal obesity) explained about half of the socioeconomic gradient. Family income, numbers of possessions and non-professional occupation were only weakly or not at all independently related to AMI. In high-income countries (World Bank Classification), the risk factor adjusted OR associated with low education was 1.61 (1.33 to 1.94), whereas it was substantially lower in low-income and middle-income countries: 1.25 (1.14 to 1.37) (p for interaction 0.045).

CONCLUSION

Of the SES measures we studied, low education was the marker most consistently associated with increased risk for AMI globally, most markedly in high-income countries.

Potentially modifiable risk factors associated with myocardial infarction in China: the INTERHEART China study

BACKGROUND

Lifestyle changes associated with the rapidly developing economy increase cardiovascular disease (CVD), myocardial infarction (MI) and cardiovascular risk factors (CVRFs) in China.

OBJECTIVE

To assess and compare regionally, and with other regions of the world, distribution of the nine INTERHEART CVRFs, their relationship to MI and the CVD epidemic in China in order to determine how this may influence the future of CVD in China.

METHODS

Patients with first acute MI (n = 3030) and age- and sex-matched controls (n = 3056) were enrolled from 26 centres in China.

RESULTS

Northern Chinese had higher rates of smoking and hypertension, whereas southern Chinese reported lower fruit and vegetable intake and higher rates of depression. Compared with other regions, participants from China were older, with lower body mass index and waist to hip ratios, lower total and low-density lipoprotein cholesterol levels, ApoB lipoprotein and ApoB to ApoA-1 ratios, but higher high-density lipoprotein cholesterol and ApoA-1. All nine INTERHEART CVRFs, education and income were significantly associated with MI in the Chinese cohort. There was significant heterogeneity in the strength of association between certain CVRFs and MI for China versus other regions, with stronger associations for the Chinese for diabetes (OR 5.10 vs 2.84), depression (2.27 vs 1.37) and permanent stress (2.67 vs 2.06); and lower for the Chinese for abdominal obesity (1.33 vs 2.62) (p for heterogeneity, all <0.001).

CONCLUSIONS

Diabetes and psychosocial factors have strong associations with risk of MI in China, indicating that future increases in these risk factors with societal change in China may hasten rapid increases in CVD.

Recalibration of a Framingham risk equation for a rural population in India

BACKGROUND

Coronary heart disease (CHD) risk estimation tools are a simple means of identifying those at high risk in a community and hence a potentially cost-effective strategy for CHD prevention in resource-poor countries. Since India has few local data upon which to develop such a tool de novo, in this study a Framingham risk equation has been recalibrated to estimate CHD risks in a population from rural India and the sensitivity of the method to information resources examined. Recent surveys of this population have found high levels of cardiovascular risk factors, particularly metabolic risk factors and a high proportion of mortality due to cardiovascular diseases.

METHODS

The proportion of a rural Indian population at high risk of CHD using three risk estimation equations was estimated. The first a published version of the Framingham risk equation, the second a recalibrated equation using local mortality surveillance data and local risk factor data, and the third a recalibrated equation using national mortality data and local risk factor data.

RESULTS

The mean 10-year probability of CHD for adults >30 years was 10.4% (9.6% to 11.1%) for men and 5.3% (4.9% to 5.7%) for women using the Framingham equation; 10.7% (9.9% to 11.5%) for men and 4.2% (3.9% to 4.5%) for women using the local recalibration; and 18.9% (17.7% to 20.1%) for men and 8.2% (7.6% to 8.8%) for women using the national recalibration.

CONCLUSION

These findings indicate that in India, equations recalibrated to summary national data are unlikely to be relevant to all regions of India and demonstrate the importance of local data collection to enable development of relevant CHD risk tools.

Mammographic density does not differ between unaffected BRCA1/2 mutation carriers and women at low-to-average risk of breast cancer

Abstract #5002

Background: Mammographic density (MD) is one of the strongest risk factors for sporadic breast cancer. Since MD is a non-invasive, reproducible and quantitative measure, it has been proposed as a compelling intermediate marker in studies aimed at understanding breast cancer etiology and prevention. The mechanism by which MD influences breast cancer risk is unknown. However, epidemiologic evidence suggests that dense breast tissue may be, in part, genetically regulated. Increased MD has been positively associated with family history of breast cancer. Family studies of sisters, including twins, provide further support for a genetic influence on MD. The relationship between MD and BRCA1/2 mutation status is equivocal.&#x2028; Methods: We examined whether MD differed between unaffected BRCA1/2 mutation carriers ages 22-55 enrolled in the Clinical Genetics Branch's Breast Imaging Study (n=143) and women at low-to-average risk of breast cancer ages 25-79 enrolled in the same study (n=29) or the National Naval Medical Center's Susceptibility to Breast Cancer Study (n=90). Low-to-average risk women were defined as being BRCA mutation-negative members of mutation-positive families; or women with no personal history of breast cancer, a Pedigree Assessment Tool score &lt;8 (i.e., low risk of a hereditary breast cancer syndrome) and a Gail score &lt;1.7. Participants from both studies had standardized, quantitative calculations of MD measured by the same experienced radiologist (CKC). Percent MD was calculated from digitized mammograms using a computerized method developed at NCI. Standard breast cancer risk factor information was collected from all subjects.&#x2028; Results: MD values were normally distributed. The intraclass correlation coefficient for MD assessed blindly in 100 paired sets was 0.889. The mean age of BRCA mutation carriers was 38.0 vs. 48.4 in low-to-average risk women. The unadjusted mean percent MD was higher in women with BRCA1/2 mutations compared with women at low-to-average breast cancer risk (37.3% vs. 33.4%; p=0.04). There was no difference in MD after adjusting for age and body mass index (35.1% vs. 36.3%; p=0.48). We explored age at menarche, nulliparity, age at first birth, menopausal status, number of breast biopsies, and exposure to exogenous hormonal agents as covariates of potential interest with regard to modulating MD. Taking these factors into account did not substantially alter the results of the age-/BMI-adjusted analysis.&#x2028; Conclusion: Our results do not provide support for an independent effect of BRCA1/2 mutation status on mammographic density. We are currently investigating whether novel quantitative characteristics imbedded within the breast parenchyma in mammographic images (e.g., texture and contrast) may have a stronger correlation with mutation status. Our goal is to identify imaging features which might more accurately classify women with regard to their breast cancer risk status.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5002.

The burden of fatal and non-fatal injury in rural India

BACKGROUND

Little is known about the burden or causes of injury in rural villages in India.

OBJECTIVE

To examine injury-related mortality and morbidity in villages in the state of Andhra Pradesh, India.

METHODS

A verbal-autopsy-based mortality surveillance study was used to collect mortality data on all ages from residents in 45 villages in 2003-2004. In early 2005, a morbidity survey in adults was carried out using stratified random sampling in 20 villages. Participants were asked about injuries sustained in the preceding 12 months. Both fatal and non-fatal injuries were coded using classification methods derived from ICD-10.

RESULTS

Response rates for the mortality surveillance and morbidity survey were 98% and 81%, respectively. Injury was the second leading cause of death for all ages, responsible for 13% (95% CI 11% to 15%) of all deaths. The leading causes of fatal injury were self-harm (36%), falls (20%), and road traffic crashes (13%). Non-fatal injury was reported by 6.7% of survey participants, with the leading causes of injury being falls (38%), road traffic crashes (25%), and mechanical forces (16.1%). Falls were more common in women, with most (72.3%) attributable to slipping and tripping. Road traffic injuries were sustained mainly by men and were primarily the result of motorcycle crashes (48.8%).

DISCUSSION

Injury is an important contributor to disease burden in rural India. The leading causes of injury-falls, road traffic crashes, and suicides-are all preventable. It is important that effective interventions are developed and implemented to minimize the impact of injury in this region.

Families of patients with premature coronary heart disease: an obvious but neglected target for primary prevention

Risk of premature coronary heart disease is increased in the families of affected patients. C K Chow and colleagues argue that targeting relatives for primary prevention would be an effective policy

A report of cardiac events in a phase II clinical study using trastuzumab combined with pertuzumab in HER2-positive metastatic breast cancer (MBC)

1028

Background: T and P are humanized recombinant monoclonal antibodies (MoAB) that target different epitopes of HER2 extracellular domain. P blocks HER2’s ability to heterodimerize with other HER/ErbB receptors. Methods: This Ph II trial evaluates the efficacy and safety of T with P in patients (pts) with HER2+ (FISH +) MBC who had progressive disease (PD) on T-based therapy. Eligible pts must have had = 3 T-based regimens, normal (nl) left ventricular ejection fraction (EF=55%) and without significant cardiac history. Pts received IV T (6mg/kg) and P (420 mg) every 3 weeks (wks). EKG plus echocardiogram (ECHO) or cardiac MRI and tumor response were assessed every 3 and 6 wks, respectively. Results: Eleven pts received 39 (1 to 13) cycles, 1 pt achieved a partial response (PR) and 3 pts had stable disease. A total of 68 ECHOs and 8 cardiac MRIs were performed. Left ventricular systolic dysfunction (LVSD) with nl EKG was seen in 5 pts; Grade (Gr) 1 (n = 2) (EF 50–55%), Gr 2 (n = 2) (EF 40–50%) and Gr 3 (n = 1) (EF20–40%). Gr 2–3 events were associated with global hypokinesis. Gr 3 event was associated with symptomatic CHF. All 5 pts had received 240mg/m2 cumulative dose of doxorubicin, 2 pts (Gr 2–3) received chest wall radiation, and 1 pt (Gr 1) had HTN. Two pts with Gr 1–2 LVSD had a history of reduced EF during prior T-based treatment, which reversed to nl upon stopping T. Reduced EF appeared within 1–2 cycles, which returned to nl in 3 pts within 1wk to 3 months (mo) post discontinuing T/P. One pt had persistent Gr 2 LVSD 3 mo after the initial event. The pt with Gr 3 LVSD had extensive chest wall disease and died of PD and possibly CHF 2 mo after treatment termination. Conclusions: We observed Gr 1–3 LVSD in patients with HER2+ MBC who received dual MoAB treatment directed at HER2, in which very strict cardiac surveillance guidelines were required. One of 11 pts achieved PR and 1 pt had symptomatic CHF thus far. It is unknown whether the other events would have become symptomatic if treatment had continued. Further evaluation of the efficacy of combination T with P is required to define the overall risk and benefit.

No significant financial relationships to disclose.

Cardiotoxicity after doxorubicin and AZD2171, an oral vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor, in patients (pts) with breast cancer

554

Background: AZD2171 selectively inhibits VEGFR 1,2,3. This trial examined the safety and efficacy of AZD2171 with anthracycline-containing therapy. Methods: Pts with previously untreated Stage IIB and III breast cancer received neoadjuvant AZD2171 (30mg) alone for one cycle (1 week) followed by daily AZD2171 and TAC chemotherapy with docetaxel (T), doxorubicin 50 mg/m2 (A) cyclophosphamide (C) for 6 cycles (Cy) every 3 weeks. Pts underwent breast surgery after completing neoadjuvant therapy. Eligible pts had left ventricular ejection fraction (EF) = 50%, and no uncontrolled HTN or cardiac history. Pts underwent electrocardiogram (EKG), and troponin first day (D) of every Cy and 24 hours after TAC as well as serial echocardiograms (echo). Cardiac stress MRI with dipyridamole was performed when pts had decreases in EF by echo. Results: Two pts received 2 Cy of AZD2171 alone, 9 Cy with TAC and AZD2171, and 1 Cy with TAC alone. Pt 1 and Pt 2 developed hypertension requiring medical therapy Cy4, D1 (148/97 mm Hg) and Cy2, D2 (169/93 mm Hg) respectively. Pt 1 had asymptomatic decrease in EF from 65% to 40% (grade 2) with global hypokinesis pre-Cy5 by echo. Troponin and EKG were negative for acute ischemia. Cardiac stress MRI was normal and EF returned to 60% within 48 hours. The pt continued therapy and pre-Cy7 EF was 51% by echo. Cumulative A dose received was 250mg/m2 pre-Cy7. AZD2171 was held while Cy7 TAC was continued. EF was 57% by echo 1 month after Cy7 TAC. Pt 2 had asymptomatic decrease in EF from 65% to 50% pre-Cy4 by echo with mild global hypokinesis. Troponin and EKG were negative for acute ischemia. Cardiac stress MRI showed EF of 56% with no ischemia. She continued AZD2171 and TAC. Pre-Cy5 EF was 35–40% (grade 3) with global hypokinesis. Troponin and EKG were negative. Cumulative dose of A received was 150mg/m2. AZD2171 and A were stopped; T and C were continued. EF normalized to 55% by cardiac stress MRI and echo within 21 days. Conclusion: Due to the systolic dysfunction that occurred with concurrent AZD2171 and doxorubicin administration, the study is closed. Future trials should administer AZD2171 and anthracyclines sequentially with stringent monitoring of blood pressure and ejection fraction.

No significant financial relationships to disclose.

The effect of raloxifene on breast MRI volume in premenopausal women at increased risk for invasive breast cancer

1518

Background: Breast MRI volume (MRIV) and mammographic density (MD) assess the amount of fibroglandular tissue in the breast. While increased MD is associated with a 4 to 6 fold increase in breast cancer risk, the association between MRIV and breast cancer is unknown. Previous studies have shown that MRIV and MD can be modulated with hormonal interventions. We evaluated the effect of raloxifene on MRIV in premenopausal women at increased risk for breast cancer. We have previously reported that raloxifene did not change MD in this cohort. Raloxifene is indicated for the prevention and treatment of osteoporosis but not for prevention of breast cancer or for use in premenopausal women. Methods: Premenopausal women at increased risk by virtue of: Gail model risk > 1.7% over 5 years; lobular neoplasia, ductal carcinoma in situ, BRCA1/2 mutation positive, or a very strong family history were eligible for this phase II chemoprevention study. MRIs obtained at baseline and after two years on raloxifene 60 mg daily, and one year after discontinuing the drug were evaluated.T1 weighted spoiled gradient-echo MRI with fat suppression was used to determine volume using a semiautomatic method, after visual verification. Median relative change in MRIV was assessed by the Wilcoxon signed rank test. Results: 19 of 30 subjects who started study drug had breast MRI at baseline and after 2 years on raloxifene; median relative change was -16% (range -57 to +25%) (p=0.0004). 17 subjects had MRI at year 2 and one year after stopping drug. No significant change in MRIV was observed after stopping raloxifene, median relative change -9% (p=0.64). Conclusions: MRIV significantly declined while on raloxifene. In contrast no significant change in percent mammographic density in this same cohort was seen. Our findings suggest that MRIV may be a better surrogate biomarker than MD in premenopausal women at risk for breast cancer because of less variation in its measurement. MRIV should be further evaluated as a potential surrogate biomarker in prevention studies.

No significant financial relationships to disclose.

Phase II clinical trial of ixabepilone in metastatic breast cancer (MBC) patients previously untreated with taxanes

651

Background: Ixabepilone, an epothilone B analog, stabilizes microtubules by binding to tubulin. The response rate (RR) in taxane-pretreated patients at our institution was 22%. Methods: Patients (pts) were eligible if they had MBC previously untreated with taxanes and measurable disease by RECIST criteria. Ixabepilone was given at 6mg/m2/d intravenously days 1–5 every 3 weeks until unacceptable toxicity or disease progression. Primary objectives included RR and toxicity. Pts underwent pre and/or post treatment tumor biopsies for correlative studies. Acetylated α-tubulin, Tau-1, and p53 were stained with anti-acetylated α-tubulin, anti-Tau-1, and anti-p53 antibodies in samples from 13 pts. Staining was scored quantitatively using the Automated Cellular Imaging System. Results: Twenty-three pts received 197 cycles (C). Median of 7C (range 2–22) per pt were administered. Median age was 55 (range 22–79). Seven pts received 1 prior metastatic chemotherapy regimen. Ten of 23 or 43% (exact 95% confidence interval: 23.2% to 65.5%) pts had partial responses (PR), 9 (39%) stable disease (SD) (2 unconfirmed PRs), and 4 (17%) progressive disease (PD). Median time to progression was 5.3 months; median duration of response was 5.4 months from date of best response. Four pts required dose reductions for neutropenia, neuropathy or fatigue. Grade 3/4 toxicities included neutropenia (22%), fatigue (13%), anorexia (9%), infection without neutropenia (9%), motor neuropathy (4%), and muscle weakness (4%). No grade 3/4 sensory neuropathy was seen, but 35% and 13% of pts had grades 1 and 2 neuropathy respectively. Median acetylated α-tubulin at baseline was 0.2 in responders and 17.6 in non-responders (p=0.069). There were no differences in response according to Tau-1 or p53 expression at baseline. Conclusion: Ixabepilone is an effective treatment for MBC with a 43% RR in 23 pts previously untreated with taxanes. There was minimal hematologic toxicity and no grade 3 sensory neuropathy. The use of baseline level of acetylated α-tubulin to predict response may warrant further study.

No significant financial relationships to disclose.

Unilateral epistaxis after swimming in a stream

A 55-year-old Chinese woman presented with a 3-week history of unilateral left-sided epistaxis and nasal obstruction. She had swam in a freshwater stream 1 month prior to the onset of symptoms. Endoscopic examination revealed a live leech at the left middle meatus with a large part of its body inside the left maxillary antrum. Local anaesthetic was applied to anaesthetise the leech and facilitate removal. Magnetic resonance imaging performed following removal confirmed that no other leeches were present in the sinonasal area. The endoparasitism might have persisted because of the inconspicuous site of infestation and the absence of pain. This form of leech infestation has not been previously reported.

Endotoxin increases hepatic susceptibility to lipid peroxidation: A possible role of iron

The purpose of this study was to investigate the possible mechanism by which endotoxin enhances peroxidative damage to membrane lipids. Male B6C3 mice were treated with endotoxin intraperitoneally 0 or 20 mg/kg body weight for 24 h. Freshly prepared liver homogenate was incubated with either 1-5 mM of reduced glutathione (GSH), glucose, H(2)O(2), ascorbic acid (AA), FeSO(4), FeCl(3), EDTA, FeCl(3) plus AA, AA plus EDTA or EDTA plus FeCl(3) in phosphate-buffered saline (PBS), pH 7.0, or PBS, at 37 degrees C for 60 min. The levels of lipid peroxidation products, thiobarbituric acid reactants (TBAR), were significantly higher in the liver of endotoxin-treated mice, and the values were markedly increased following incubation. Compared to PBS, incubation with H(2)O(2), FeCl(3), FeSO(4), and AA, but not glucose, significantly enhanced TBAR formation. The greatest increase of TBAR was found when AA and FeCl(3) were added together. On the other hand, EDTA and GSH inhibited the formation of TBAR during incubation. When added before AA, EDTA completely inhibited the peroxidative effect of AA or FeSO4, and when added subsequent to AA, EDTA partially prevented the adverse effect of AA. The results obtained suggest that ionic iron plays an important role in initiating endotoxin-induced peroxidative damage to membrane lipids, and that AA may be involved in releasing iron from its protein complex and/or maintaining ionic iron in a reduced or catalytic state.

Dietary vitamin E and selenium and toxicity of nitrite and nitrate

Nitrites and nitrates are important antimicrobial and flavoring/coloring agents in meat and fish products. However, nitrites and nitrates may cause methemoglobinemia and other illness, and may react with certain amines to form carcinogenic nitrosamines. The nutritional status of vitamin E and selenium has long been associated with nitrite and nitrate toxicity, although the mechanism involved is not yet clear. Information available recently shows that nitrites and nitrates are both oxidation products and ready sources of nitric oxide (NO*), that NO* reacts rapidly with superoxide to form highly reactive peroxynitrite (ONOO-), and that vitamin E may mediate the generation and availability of superoxide and NO*. Increased formation of ONOO- resulting from nitrite treatment and low intake of vitamin E and selenium may thus be the critical event leading to tissue damage and animal mortality observed previously. The protection against the adverse effects of nitrites/nitrates by vitamin E is attributed to its ability to reduce ONOO- formation, while selenium exerts its protective effects via seleno-enzymes/compounds, which reduce ONOO- formed.

Peroxisome proliferator perfluorodecanoic acid alters glutathione and related enzymes

Previously we have shown that treatment with the peroxisome proliferator perfluorodecanoic acid (PFDA) significantly increased hepatic reduced glutathione (GSH) content without altering the activity of selenium-glutathione peroxidase. In this study we examined some potential mechanisms by which PFDA treatment increases GSH levels. Male Sprague-Dawley rats were given a single injection of 0, 8.8, 17.5, and 35 mg PFDA in corn oil per kg body weight. Twelve days later the effects of PFDA on the activities of enzymes associated with GSH synthesis, utilization, and regeneration were assessed. The results showed that in a dose-dependent manner, PFDA treatment significantly decreased the activity of gamma-glutamylcysteine synthetase, while the activities of NADPH-generating enzymes, malic enzyme, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase were increased. PFDA treatment also dose dependently decreased cytosolic, but not microsomal, glutathione S-transferase activity, and the activity of glutathione reductase was decreased by the highest dose of PFDA. The data obtained suggest that increased hepatic GSH levels following PFDA treatment may result from increased regeneration and/or decreased utilization.

Effect of the neuroprotective agent riluzole on intracellular Ca2+ levels in IMR32 neuroblastoma cells

Riluzole is an effective neuroprotective drug. Its effect on intracellular free Ca2+ levels ([Ca2+]i) has not been explored. This study examined the effect of riluzole on [Ca2+]i in IMR32 neuroblastoma cells using fura-2 as a Ca2+ probe. Riluzole 0.1-1 mM increased [Ca2+]i in a concentration-dependent manner. Removal of extracellular Ca2+ inhibited the response by 52 +/- 5%. The [Ca2+]i increase induced by 0.2 mM riluzole was unaltered by 0.1 mM La3+ or 10 microM verapamil, but was inhibited by 51 +/- 4% by 10 microM nifedipine. In Ca2+-free medium, pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) reduced the 0.2 mM riluzole-induced Ca2+ release by 44 +/- 3%; this reduction was augmented to 66 +/- 5% by additionally depleting the Ca2+ stores in the Golgi complex with 50 microM brefeldin A. Inhibition of inositol 1,4,5-trisphosphate formation by 2 microM U73122, a phospholipase C inhibitor, did not affect Ca2+ release induced by 0.2 microM riluzole. It was concluded that the neuroprotective agent riluzole increased [Ca2+]i in IMR32 neuroblastoma cells concentration-dependently by releasing Ca2+ from multiple stores in an inositol 1,4,5-trisphosphate-independent manner and also by inducing nifedipine-sensitive Ca2+ influx.

High levels of dietary carnosine are associated with increased concentrations of carnosine and histidine in rat soleus muscle

The aims of this investigation were to: 1) determine the effect of a moderately high dose of carnosine on muscle concentrations of carnosine, histidine and vitamin E at deficient, minimally adequate and sufficient levels of dietary vitamin E and 2) compare the effects of moderately high and pharmacological doses of carnosine on muscle concentrations of carnosine, histidine and vitamin E when dietary vitamin E is minimally adequate. Muscle concentrations of carnosine, histidine and vitamin E were measured in the lateral gastrocnemius and red and white vastus lateralis; carnosine and histidine concentrations were also measured in soleus muscle. Male Sprague-Dawley rats (n = 12/group) were fed a basal vitamin E-deficient diet supplemented with either 0, 0.001 or 0.01% vitamin E and 0, 0.1 or 1.8% carnosine. After 8 wk, 1.8% carnosine resulted in significant fivefold increases in carnosine and twofold increases in histidine in the soleus muscle (P < or = 0.05). Muscle vitamin E concentrations were not significantly affected by dietary carnosine. Thus, very high levels of dietary carnosine are associated with increases in carnosine and histidine concentrations in rat soleus muscle.

Vitamin E regulation of mitochondrial superoxide generation

The mitochondrion is the greatest source, as well as the target, of reactive oxygen species (ROS). Increasing evidence indicates that vitamin E can act as a biological modifier independently of its antioxidant activity. Experimental evidence available shows that vitamin E is capable of dose-dependently regulating mitochondrial generation of superoxide and hydrogen peroxide. Vitamin E may modulate mitochondrial production and levels of superoxide by preventing electron leakage, by mediating the superoxide generation systems directly and/or by scavenging superoxide generated. By downregulating mitochondrial generation of superoxide and related ROS, vitamin E not only attenuates oxidative damage but also modulates the expression and activation of signal transduction pathways and other redox-sensitive biological modifiers.

Dietary coenzyme Q10 and vitamin E alter the status of these compounds in rat tissues and mitochondria

Vitamin E (VE) and coenzyme Q (CQ) are essential for maintaining functions and integrity of mitochondria, and high concentrations of these compounds are found in their inner membranes. This study was conducted to examine the interaction between exogenously administered CQ10 and VE in rats. Male Sprague-Dawley rats (12 mo old) were fed a basal diet (10 IU VE or 6.7 mg RRR-alpha-tocopherol equivalent) supplemented with either 0 or 500 mg CQ10, and 0, 100 or 1310 IU VE/kg diet for 14 or 28 d. Liver, spleen, heart, kidney, skeletal muscle, brain and serum were analyzed for the levels of CQ10, CQ9 and VE. CQ10 supplementation significantly (P: < 0.05) increased CQ10 concentration in the liver and spleen (total and mitochondria) and serum, but not in other organs. Interestingly, rats supplemented with CQ10 plus 100 IU VE/kg diet had significantly higher CQ10 levels in the liver and spleen, whereas those supplemented with CQ10 plus 1310 IU VE/kg diet had lower levels, compared with those supplemented with CQ10 alone. As expected, dietary VE increased VE content in all of the organs analyzed in a dose-dependent manner. However, rats fed the basal diet supplemented with CQ10 had significantly higher VE levels in liver (total and mitochondria) than those not receiving CQ10 supplementation. CQ9 levels were higher in the liver and spleen, lower in skeletal muscle and unaltered in brain, serum, heart and kidney of rats supplemented with CQ10 compared with the controls. These data provide direct evidence for an interactive effect between exogenously administered VE and CQ10 in terms of tissue uptake and retention, and for a sparing effect of CQ10 on VE. Data also suggest that dietary VE plays a key role in determining tissue retention of exogenous CQ10.

Effect of tamoxifen on mammographic density

There are strong data showing that increased breast cancer risk is associated with increased mammographic density. Tamoxifen has been shown to decrease the risk of invasive breast cancer and decrease breast density. We sought to demonstrate and calculate the extent of change in mammographic density in women who have taken tamoxifen for up to 2 years. We evaluated mammograms from 28 high-risk women who were taking tamoxifen. Four different methods of evaluation were used: (a) two qualitative methods (Wolfe criteria and the American College of Radiology Breast Imaging and Reporting Data System criteria); (b) one semiquantitative method (mammograms were assigned one of five semiquantitative scores by visual inspection); and (c) one quantitative method (computer-aided calculation of fibroglandular area from digitized mammograms). The Wolfe criteria showed a 0.03 category decrease per year (P = 0.50). The American College of Radiology Breast Imaging and Reporting Data System criteria showed a 0.1 category decrease per year (P = 0.12). Semiquantitative criteria showed a 0.2 category decrease per year (P = 0.039). Digitized scores showed a 4.3% decrease per year (P = 0.0007). In conclusion, tamoxifen causes a decrease in mammographic density with use, an effect that is better quantitated with semiquantitative criteria or digitized images. Density change might become useful as a surrogate end point for the effect of tamoxifen and other chemopreventive measures, although our data do not predict an individual's degree of risk reduction.

Symmetries of excited heavy baryons in the heavy-quark and large- N(c) limit

We demonstrate in a model independent way that, in the combined heavy-quark and large- N(c) limit, there exists a new contracted U(4) symmetry which connects orbitally excited heavy baryons to the ground states.

Antioxidant and oxidative status in tissues of manganese superoxide dismutase transgenic mice

Manganese superoxide dismutase (Mn-SOD) plays an important role in attenuating free radical-induced oxidative damage. The purpose of this research was to determine if increased expression of Mn-SOD gene alters intracellular redox status. Twelve week old male B6C3 mice, engineered to express human Mn-SOD in multiple organs, and their nontransgenic littermates were assessed for oxidative stress and antioxidant status in heart, brain, lung, skeletal muscle, liver, and kidney. Relative to their nontransgenic littermates, transgenic mice had significantly (p <.01) higher activity of Mn-SOD in heart, skeletal muscle, lung, and brain. Copper, zinc (Cu,Zn)-SOD activity was significantly higher in kidney, whereas catalase activity was lower in brain and liver. The activities of selenium (Se)-GSH peroxidase and non-Se-GSH peroxidase, and levels of vitamin E, ascorbic acid and GSH were not significantly different in any tissues measured between Mn-SOD transgenic mice and their nontransgenic controls. The levels of malondialdehyde were significantly lower in the muscle and heart of Mn-SOD mice, and conjugated dienes and protein carbonyls were not altered in any tissues measured. The results obtained showed that expression of human SOD gene did not systematical alter antioxidant systems or adversely affect the redox state of the transgenic mice. The results also suggest that expression of human SOD gene confers protection against peroxidative damage to membrane lipids.

Interaction of antioxidants and their implication in genetic anemia

The generation of reactive oxygen species (ROS) is a steady-state cellular event in respiring cells. Their production can be grossly amplified in response to a variety of pathophysiological conditions such as inflammation, immunologic disorders, hypoxia, hyperoxia, metabolism of drug or alcohol, exposure to UV or therapeutic radiation, and deficiency in antioxidant vitamins. Uncontrolled production of ROS often leads to damage of cellular macromolecules (DNA, protein, and lipids) and other small antioxidant molecules. A number of major cellular defense mechanisms exist to neutralize and combat the damaging effects of these reactive substances. The enzymic system functions by direct or sequential removal of ROS (superoxide dismutase, catalase, and glutathione peroxidase), thereby terminating their activities. Metal binding proteins, targeted to bind iron and copper ions, ensure that these Fenton metals are cryptic. Nonenzymic defense consists of scavenging molecules that are endogenously produced (GSH, ubiquinols, uric acid) or those derived from the diet (vitamins C and E, lipoic acid, selenium, riboflavin, zinc, and the carotenoids). These antioxidant nutrients occupy distinct cellular compartments and among them, there are active recycling. For example, oxidized vitamin E (tocopheroxy radical) has been shown to be regenerated by ascorbate, GSH, lipoic acid, or ubiquinols. GSH disulfides (GSSG) can be regenerated by GSSG reductase (a riboflavin-dependent protein), and enzymic pathways have been identified for the recycling of ascorbate radical and dehydroascorbate. The electrons that are used to fuel these recycling reactions (NADH and NADPH) are ultimately derived from the oxidation of foods. Sickle cell anemia, thalassemia, and glucose-6-phosphate-dehydrogenase deficiency are all hereditary disorders with higher potential for oxidative damage due to chronic redox imbalance in red cells that often results in clinical manifestation of mild to serve hemolysis in patients with these disorders. The release of hemoglobin during hemolysis and the subsequent therapeutic transfusion in some cases lead to systemic iron overloading that further potentiates the generation of ROS. Antioxidant status in anemia will be examined, and the potential application of antioxidant treatment as an adjunct therapy under these conditions will be discussed.

Interaction of antioxidants and their implication in genetic anemia

The generation of reactive oxygen species (ROS) is a steady-state cellular event in respiring cells. Their production can be grossly amplified in response to a variety of pathophysiological conditions such as inflammation, immunologic disorders, hypoxia, hyperoxia, metabolism of drug or alcohol, exposure to UV or therapeutic radiation, and deficiency in antioxidant vitamins. Uncontrolled production of ROS often leads to damage of cellular macromolecules (DNA, protein, and lipids) and other small antioxidant molecules. A number of major cellular defense mechanisms exist to neutralize and combat the damaging effects of these reactive substances. The enzymic system functions by direct or sequential removal of ROS (superoxide dismutase, catalase, and glutathione peroxidase), thereby terminating their activities. Metal binding proteins, targeted to bind iron and copper ions, ensure that these Fenton metals are cryptic. Nonenzymic defense consists of scavenging molecules that are endogenously produced (GSH, ubiquinols, uric acid) or those derived from the diet (vitamins C and E, lipoic acid, selenium, riboflavin, zinc, and the carotenoids). These antioxidant nutrients occupy distinct cellular compartments and among them, there are active recycling. For example, oxidized vitamin E (tocopheroxy radical) has been shown to be regenerated by ascorbate, GSH, lipoic acid, or ubiquinols. GSH disulfides (GSSG) can be regenerated by GSSG reductase (a riboflavin-dependent protein), and enzymic pathways have been identified for the recycling of ascorbate radical and dehydroascorbate. The electrons that are used to fuel these recycling reactions (NADH and NADPH) are ultimately derived from the oxidation of foods. Sickle cell anemia, thalassemia, and glucose-6-phosphate-dehydrogenase deficiency are all hereditary disorders with higher potential for oxidative damage due to chronic redox imbalance in red cells that often results in clinical manifestation of mild to serve hemolysis in patients with these disorders. The release of hemoglobin during hemolysis and the subsequent therapeutic transfusion in some cases lead to systemic iron overloading that further potentiates the generation of ROS. Antioxidant status in anemia will be examined, and the potential application of antioxidant treatment as an adjunct therapy under these conditions will be discussed.

Efficacy of antifungal agents in tissue conditioners in treating candidiasis

Chronic atrophic candidiasis is prevalent in up to 72% of institutionalized geriatric populations and is causally associated with Candida albicans. Topical antifungal treatments are difficult to implement in some geriatric patients due to cognitive impairment, reduced motor dexterity and memory loss.

OBJECTIVE

This in vitro study incorporated antifungal agents into tissue conditioners to investigate the effectiveness of this method of drug delivery.

DESIGN

Combinations of nystatin, fluconazole, itraconazole and Coe Soft, Viscogel, Fitt were tested at 1, 3, 5, 7, 9 and 11 wt/wt%, with and without sterilized saliva. 6 mm diameter cores were punched in Sabouraud plates pre-grown with standardized C. albicans. Antifungal agents plus tissue conditioner mixtures were injected into each core. Inhibition diameters were measured for 14 days.

RESULTS

Cores with only tissue conditioners acted as negative control and showed no significant inhibition activity (ANOVA, p > 0.05). Peak activity was between 65 to 89 hours; followed by a plateau. Itraconazole had greater fungicidal activity than fluconazole; while nystatin was found to have the least fungicidal activity (ANOVA, p < 0.05). The most effective concentration for nearly all combinations was 5% wt/wt (ANOVA, p < 0.05). Specimens with saliva showed greater antifungal activity than those without (t-test, p < 0.001). Itraconazole altered the physical properties of Viscogel hence this combination is not recommended for clinical use.

CONCLUSION

The treatment of chronic atrophic candidiasis by incorporation of antifungal drugs into tissue conditioners is efficacious. 5% wt/wt itraconazole mixed with Coe Soft or Fitt is recommended for clinical study where compliance of patient or care giver cannot be relied upon. Peak antifungal activity at 3 days suggests that mixtures prepared for clinical study may be replaced soon after this time for maximum effectiveness.

Oxidative stress and antioxidant status in mouse kidney: effects of dietary lipid and vitamin E plus iron

The purpose of this study was to determine the effects of dietary fat, vitamin E, and iron on oxidative damage and antioxidant status in kidneys of mice. Sixty 1-month-old male Swiss-Webster mice were fed a basal vitamin E-deficient diet that contained either 8% fish oil + 2% corn oil or 10% lard with or without 1 g all-rac-alpha-tocopherol acetate or 0.74 g ferric citrate per kilogram of diet for 4 weeks. Significantly (P < 0.05) higher levels of lipid peroxidation products, thiobarbituric acid reactants (TBAR), and conjugated dienes were found in the kidneys of mice fed with fish oil compared with mice fed lard irrespective of vitamin E status. Mice maintained on a vitamin E-deficient diet had significantly higher renal levels of TBAR, but not conjugated dienes, than the supplemented group. Fish oil fed mice receiving vitamin E supplementation had lower levels of alpha-tocopherol than did mice in the lard fed group. Significantly higher levels of ascorbic acid were also found in the kidneys of mice fed with fish oil than were found in mice fed lard. The levels of protein carbonyls and glutathione (GSH), and activities of catalase, superoxide dismutase, selenium (Se)-GSH peroxidase, and non-Se-GSH peroxidase were not significantly altered by dietary fat or vitamin E. Dietary iron had no significant effect on any of the oxidative stress and antioxidant indices measured. The results obtained provide experimental evidence for the pro-oxidant effect of high fish oil intake in mouse kidney and suggest that dietary lipids play a key role in determining cellular susceptibility to oxidative stress.

Antioxidant supplementation effects on low-density lipoprotein oxidation for individuals with type 2 diabetes mellitus

OBJECTIVE

This study compared susceptibility to oxidation of low-density lipoproteins (LDL) of non-diabetic and diabetic (Type 2) men and examined the response of diabetic men to antioxidant supplementation (alpha-tocopherol, beta-carotene and ascorbate).

RESEARCH DESIGN AND METHODS

Twenty adult non-diabetic and 20 diabetic men were recruited. Oxidation of LDL was assessed by four different assay systems, and the extent of oxidation was assessed by four different measurements. Diabetic men received eight weeks of placebo ("baseline"), twelve weeks of antioxidant supplements ("treated") and eight weeks of placebo ("post-treatment"). Supplements provided 24 mg of beta-carotene, 1000 mg of ascorbate and 800 IU of alpha-tocopherol daily.

RESULTS

With Cu oxidation at 37 degrees C, thiobarbituric reactive substances (TBARS) formation was significantly higher (p=0.032) and loss of free amine groups was significantly greater (p=0.013) in the LDL from diabetic subjects than controls. Antioxidant supplementation of diabetic subjects significantly decreased all parameters of LDL oxidation with Cu at 30 degrees C and 37 degrees C. At 30 degrees C the lag phase increased from 55 to 129 minutes (p<0.0001); conjugated diene formation decreased from 1.23 to 0.62 OD units (p<0.0001); TBARS formation decreased from 78 to 33 nmoles MDA/mg LDL protein (p<0.0001); and free amine loss decreased from 41 to 12% (p<0.0001). With Cu oxidation at 37 degrees C, similar changes occurred.

CONCLUSIONS

These studies indicate that the LDL from diabetic subjects are more susceptible to oxidation than LDL from non-diabetic subjects. Supplementation of diabetic subjects with antioxidant vitamins significantly decreases susceptibility of LDL to oxidation by Cu. These studies are consistent with epidemiological and intervention studies suggesting that antioxidant vitamin use significantly decreases risk for coronary heart disease.

Partial monosomy of distal 10q: three new cases and a review

We report on 3 patients with partial deletions of the long arm of chromosome 10-46,XY,del (10)(q26.2), 46,XX,del(10) (q25.3q26.3) or 46,XX,del(10)(q26.1), and 46,XX,del (10)(q26.1). They are compared with other known cases with interstitial or terminal deletions involving chromosome bands 10q25 or q26. Unique manifestations are identified, including scoliosis and a severe behavior disorder with attention deficit and hyperactivity in a 12-year-old boy as well as patchy alopecia in a 6-year-old patient.

Vitamin E regulates mitochondrial hydrogen peroxide generation

The mitochondrial electron transport system consumes more than 85% of all oxygen used by the cells, and up to 5% of the oxygen consumed by mitochondria is converted to superoxide, hydrogen peroxide, and other reactive oxygen species (ROS) under normal physiologic conditions. Disruption of mitochondrial ultrastructure is one of the earliest pathologic events during vitamin E depletion. The present studies were undertaken to test whether a direct link exists between vitamin E and the production of hydrogen peroxide in the mitochondria. In the first experiment, mice were fed a vitamin E-deficient or-sufficient diet for 15 weeks, after which the mitochondria from liver and skeletal muscle were isolated to determine the rates of hydrogen peroxide production. Deprivation of vitamin E resulted in an approximately 5-fold increase of mitochondrial hydrogen peroxide production in skeletal muscle and a 1-fold increase in liver when compared with the vitamin E-supplemented group. To determine whether vitamin E can dose-dependently influence the production of hydrogen peroxide, four groups of male and female rats were fed diets containing 0, 20, 200, or 2000 lU/kg vitamin E for 90 d. Results showed that dietary vitamin E dose-dependently attenuated hydrogen peroxide production in mitochondria isolated from liver and skeletal muscle of male and female rats. Female rats, however, were more profoundly affected by dietary vitamin E than male rats in the suppression of mitochondrial hydrogen peroxide production in both organs studied. These results showed that vitamin E can directly regulate hydrogen peroxide production in mitochondria and suggest that the overproduction of mitochondrial ROS is the first event leading to the tissue damage observed in vitamin E-deficiency syndromes. Data further suggested that by regulating mitochondrial production of ROS, vitamin E modulates the expression and activation of signal transduction pathways and other redox-sensitive biologic modifiers, and thereby delays or prevents degenerative tissue changes.

Impaired production of nitric oxide, superoxide, and hydrogen peroxide in glucose 6-phosphate-dehydrogenase-deficient granulocytes

Since the generation of superoxide and hydrogen peroxide by NADPH oxidase and nitric oxide (NO) by NO synthase (NOS) in granulocytes is NADPH-dependent, we investigated the production of NO, superoxide and H2O2 in glucose 6-phosphate dehydrogenase (G6PD)-deficient human granulocytes. Our results showed that upon stimulation with either 5 microg/ml of lipopolysaccharide (LPS) or 10 microM of phorbol 12-myristate 13-acetate (PMA), the production of nitrite in normal granulocytes was elevated, 252 +/- 135% and 239 +/- 72%, respectively, compared to the resting stage. In contrast, G6PD-deficient granulocytes did not produce more nitrite upon stimulation with either LPS or PMA compared to the resting stage. Western blot analysis indicated a normal expression pattern of inducible NOS in G6PD-deficient granulocytes. In addition, the production of H2O2 and superoxide was also significantly impaired in G6PD-deficient granulocytes compared to control cells. These data demonstrate that G6PD deficiency causes an impairment in the production of NO, superoxide and H2O2.

Juvenile idiopathic inflammatory myopathy: exercise-induced changes in muscle at short inversion time inversion-recovery MR imaging

PURPOSE

To study the effect of exercise on short inversion time inversion-recovery (STIR) magnetic resonance (MR) images of thigh muscles in children with juvenile idiopathic inflammatory myopathy.

MATERIALS AND METHODS

Thirty-two MR studies were performed in 19 patients with juvenile idiopathic inflammatory myopathy who performed stair-stepping exercise for up to 10 minutes (mean, 5.7 minutes). Baseline T1-weighted (n = 32) and STIR (n = 32) images and STIR images immediately (n = 32) and at 30 (n = 24) and 60 (n = 29) minutes after exercise were obtained at 0.5 T. Four radiologists graded STIR signal intensity changes, in observer performance experiments in which they were blinded to the order of image acquisition in relation to exercise.

RESULTS

Changes in muscle signal intensity were observed on STIR images obtained immediately after exercise in 20 of 32 (63%) studies. The mean signal intensity score immediately after exercise (1.7 +/- 1.0 [SD]) increased compared with the mean baseline score (1.4 +/- 1.1) (P = .0005) and resolved by 30 minutes after exercise. The magnitude of exercise-induced changes correlated with the amount of work performed (r = 0.51, P = .003) but not with disease activity or baseline signal intensity when the changes were corrected for work (r < 0.17, P > .35). Radiologists demonstrated moderate to substantial agreement in the grading of signal intensity changes after exercise (kappa = 0.60-0.84).

CONCLUSION

In patients with juvenile idiopathic inflammatory myopathy, stair-stepping exercise induces signal intensity changes on STIR MR studies of muscle for approximately 30 minutes after exercise, in a distribution that may mimic active muscle inflammation.

Syndrome of spotty skin pigmentation, myxomas, endocrine overactivity, and schwannomas (Carney complex): breast imaging findings

PURPOSE

To study the imaging appearances of breast lesions in female patients with Carney complex.

MATERIALS AND METHODS

Seven patients with Carney complex underwent mammography (n = 5), ultrasound (US) (n = 6), or magnetic resonance (MR) imaging (n = 6) in a prospective study. Previous breast images in three patients were reviewed. Mammograms in two additional patients were retrospectively reviewed. Thus, nine patients aged 16-61 were included in this study.

RESULTS

Mammograms showed well-defined, iso- or hypodense masses; most were not calcified. Two lesions contained calcifications; both were biopsy-proved ductal adenomas. US demonstrated solid, hypoechoic, well-circumscribed masses in six patients and complex cystic masses (myxoid fibroadenomas) in one patient. MR imaging with a fat-suppressed, fast spin-echo, T2-weighted sequence demonstrated high-signal-intensity lesions (n = 5). Fat-suppressed, spoiled gradient-recalled-echo MR images demonstrated hypointense lesions with variable contrast material enhancement (n = 5). Five of seven patients in the prospective review had multiple breast lesions on at least one study. Mammograms and US scans were negative in three patients each. Chest and breast MR images were negative in only one patient.

CONCLUSION

Female patients with Carney complex often have multiple breast masses with variable imaging appearances that probably represent myxoid fibroadenomas or ductal adenomas. MR imaging showed the most lesions. These lesions all demonstrate benign characteristics and should not prompt multiple biopsies.