Large Iodine Variability in Retail Cows' Milk in the U.S.: A Follow-Up Study among Different Retail Outlets

In a previous study, large variability in iodine content was found among samples of store brand retail milk at a single time point in a sampling taken from 24 nationwide U.S. locations for the USDA FoodData Central database, but the sampling plan was not designed to detect differences among locations. This follow-up study was carried out to evaluate iodine levels in retail milk across the U.S. over time. Milk samples (2% fat) were collected bimonthly in fourteen locations for one year and analyzed in duplicate. Control materials were used to support accuracy of results and ensure precision across analytical batches. The overall mean and standard error (SE) for iodine concentration were 82.5 (7.0) µg/240 mL serving, which was comparable to the previous national mean [85.0 (5.5) µg/240 mL]. A similar wide range among individual samples was detected (27.9-282 µg/240 mL). For some locations, the mean iodine concentration differed significantly from others, and differed from the national average by amounts ranging from -47 µg to +37 µg per serving. The between-sample range within location was large for some (up to 229 µg/serving) and minimal for others (as little as 13.2 µg/serving). These findings suggest iodine intake from some retail milk supplies could be over- or underestimated relative to the national average, even if the national average is suitable for population-wide intake estimates.

The Type and Amount of Dietary Fat Affect Plasma Factor VIIc, Fibrinogen, and PAI-1 in Healthy Individuals and Individuals at High Cardiovascular Disease Risk: 2 Randomized Controlled Trials

BACKGROUND

Factor VIIc, fibrinogen, and plasminogen activator inhibitor 1 (PAI-1) are cardiovascular disease (CVD) risk factors and are modulated, in part, by fat type and amount.

OBJECTIVE

We evaluated fat type and amount on the primary outcomes: factor VIIc, fibrinogen, and PAI-1.

METHODS

In the Dietary Effects on Lipoproteins and Thrombogenic Activity (DELTA) Trial, 2 controlled crossover feeding studies evaluated substituting carbohydrate or MUFAs for SFAs. Study 1: healthy participants (n = 103) were provided with (8 wk) an average American diet [AAD; designed to provide 37% of energy (%E) as fat, 16% SFA], a Step 1 diet (30%E fat, 9% SFA), and a diet low in SFA (Low-Sat; 26%E fat, 5% SFA). Study 2: participants (n = 85) at risk for CVD and metabolic syndrome (MetSyn) were provided with (7 wk) an AAD, a step 1 diet, and a high-MUFA diet (designed to provide 37%E fat, 8% SFA, 22% MUFA).

RESULTS

Study 1: compared with AAD, the Step 1 and Low-Sat diets decreased mean factor VIIc by 1.8% and 2.6% (overall P = 0.0001), increased mean fibrinogen by 1.2% and 2.8% (P = 0.0141), and increased mean square root PAI-1 by 0.0% and 6.0% (P = 0.0037), respectively. Study 2: compared with AAD, the Step 1 and high-MUFA diets decreased mean factor VIIc by 4.1% and 3.2% (overall P < 0.0001), increased mean fibrinogen by 3.9% and 1.5% (P = 0.0083), and increased mean square-root PAI-1 by 2.0% and 5.8% (P = 0.1319), respectively.

CONCLUSIONS

Replacing SFA with carbohydrate decreased factor VIIc and increased fibrinogen in healthy and metabolically unhealthy individuals and also increased PAI-1 in healthy subjects. Replacing SFA with MUFA decreased factor VIIc and increased fibrinogen but less than carbohydrate. Our results indicate an uncertain effect of replacing SFA with carbohydrate or MUFA on cardiometabolic risk because of small changes in hemostatic factors and directionally different responses to decreasing SFA. This trial was registered at https://clinicaltrials.gov/ct2/show/NCT00000538?term=NCT00000538&rank=1 as NCT00000538.

The Dietary Supplement Label Database: Recent Developments and Applications

Objective

To describe the history, key features, recent enhancements, and common applications of the Dietary Supplement Label Database (DSLD).

Background and History

Although many Americans use dietary supplements, databases of dietary supplements sold in the United States have not been widely available. The DSLD, an easily accessible public-use database was created in 2008 to provide information on dietary supplement composition for use by researchers and consumers.

Rationale

Accessing current information easily and quickly is crucial for documenting exposures to dietary supplements because they contain nutrients and other bioactive ingredients that may have beneficial or adverse effects on human health. This manuscript details recent developments with the DSLD to achieve this goal and provides examples of how the DSLD has been used.

Recent Developments

With periodic updates to track changes in product composition and capture new products entering the market, the DSLD currently contains more than 71,000 dietary supplement labels. Following usability testing with consumer and researcher user groups completed in 2016, improvements to the DSLD interface were made. As of 2017, both a desktop and mobile device version are now available. Since its inception in 2008, the use of the DSLD has included research, exposure monitoring, and other purposes by users in the public and private sectors.

Future Directions

Further refinement of the user interface and search features to facilitate ease of use for stakeholders is planned.

Conclusions

The DSLD can be used to track changes in product composition and capture new products entering the market. With over 71,000 DS labels it is a unique resource that policymakers, researchers, clinicians, and consumers may find valuable for multiple applications.

Characteristics and Challenges of Dietary Supplement Databases Derived from Label Information

Launched in 2008, the Dietary Supplement Label Database (DSLD) permits the search of any term that appears anywhere on product labels. Since then, the database's search and download features have been periodically improved to enhance use for researchers and consumers. In this review, we describe how to customize searches and identify products and ingredients of interest to users in the DSLD, and provide the limitations of working with information derived from dietary supplement product labels. This article describes how data derived from information printed on product labels are entered and organized in the DSLD. Among the challenges are determining the chemical forms, types of extract, and amounts of dietary ingredients, especially when these are components of proprietary blends. The FDA announced new dietary supplement labeling regulations in May 2016. The 2017 DSLD has been updated to reflect them. These new regulations and examples cited in this article refer to this redesigned version of the DSLD. Search selection characteristics such as for product type and intended user group are as described in FDA guidance and regulations for dietary supplements. For this reason, some age groups (such as teens and seniors) and marketing recommendations for use (e.g., weight loss, performance, and other disease- or condition-specific claims) are not included in the search selections. The DSLD user interface features will be revised periodically to reflect regulatory and technologic developments to enhance user experience. A comprehensive database derived from analytically verified data on composition would be preferable to label data, but is not feasible for technical, logistic, and financial reasons. Therefore, a database derived from information printed on product labels is the only practical option at present for researchers, clinicians, and consumers interested in the composition of these products.

Federal Monitoring of Dietary Supplement Use in the Resident, Civilian, Noninstitutionalized US Population, National Health and Nutrition Examination Survey.. J Nutr 2018;148:1436S-1444S. [PMID: 31105335 PMCID: PMC6516064 DOI: 10.1093/jn/nxy093]

Objective

This review summarizes the current and previous data on dietary supplement (DS) use collected from participants in the National Health and Nutrition Examination Survey (NHANES), describes the NHANES dietary supplement database used to compute nutrient intakes from DSs, discussed recent developments and future direction, and describes many examples to demonstrate the utility of these data in informing nutrition research and policy.

Background and History

Since 1971, NHANES, has been collecting information on the use of DSs from participants. These data are critical to national nutrition surveillance and have been used to characterize usage patterns, examine trends over time, assess the percentage of the population meeting or exceeding nutrient recommendations, and to help elucidate the sources contributing nutrients to the diet of the US population.

Rationale

Over half of adults and about one-third of children in the United States use at least one dietary supplement in the past 30 days. Dietary supplements contribute to the dietary intake of nutrients and bioactive compounds in the US and therefore need to be assessed when monitoring nutritional status of the population and when studying diet-health associations.

Recent Developments

With the recent development and availability of the Dietary Supplement Label Database (DSLD), a comprehensive DS database that will eventually contain labels for all products marketed in the US, NHANES DS data will be more easily linked to product information to estimate nutrient intake from DS.

Future Directions

Over time, NHANES has both expanded and improved collection methods. The continued understanding of sources of error in collection methods will continue to be explored and is critical to improved accuracy.

Conclusions

NHANES provides a rich source of nationally representative data on the usage of dietary supplements in the US.

Is Nutrient Content and Other Label Information for Prescription Prenatal Supplements Different from Nonprescription Products?

BACKGROUND

Prenatal supplements are often recommended to pregnant women to help meet their nutrient needs. Many products are available, making it difficult to choose a suitable supplement because little is known about their labeling and contents to evaluate their appropriateness.

OBJECTIVE

To determine differences between prescription and nonprescription prenatal supplements available in the United States regarding declared nutrient and nonnutrient ingredients and the presence of dosing and safety-related information.

DESIGN

Using two publicly available databases with information about prenatal supplement products, information from prescription and nonprescription product labels were extracted and evaluated. For the 82 prescription and 132 nonprescription products, declared label amounts of seven vitamins and minerals, docosahexaenoic acid (DHA), the presence of other nonnutrient components, and the presence of key safety and informational elements as identified in two Department of Health and Human Services Office of Inspector General (OIG)'s 2003 reports were compiled and compared.

RESULTS

Compared with nonprescription products, prescription products contained significantly fewer vitamins (9±0.2 vs 11±0.3; P≤0.05) and minerals (4±0.1 vs 8±0.3; P≤0.05). Declared amounts of folic acid were higher in prescription products, whereas vitamin A, vitamin D, iodine, and calcium were higher in the nonprescription products. Amounts of iron, zinc, and DHA were similar. Virtually all products contained levels of one or more nutrients that exceeded the Recommended Dietary Allowances for pregnant and/or lactating women. Product type also influenced ingredients added. Fewer prescription products contained botanical ingredients (6% prescription vs 33% nonprescription) and probiotics (2% prescription vs 8% nonprescription). Only prescription products contained the stool softener docusate sodium.

CONCLUSIONS

Our analysis of prenatal supplements indicates that prescription and nonprescription supplements differ in terms of declared composition and nutrient strength, but have labels that are similarly sparse regarding aspects of use such as dosing information.

National Institutes of Health Research Plan on Rehabilitation: NIH Medical Rehabilitation Coordinating Committee

One in five Americans experiences disability that affects their daily function because of impairments in mobility, cognitive function, sensory impairment, or communication impairment. The need for rehabilitation strategies to optimize function and reduce disability is a clear priority for research to address this public health challenge. The National Institutes of Health (NIH) recently published a Research Plan on Rehabilitation that provides a set of priorities to guide the field over the next 5 years. The plan was developed with input from multiple Institutes and Centers within the NIH, the National Advisory Board for Medical Rehabilitation Research, and the public. This article provides an overview of the need for this research plan, an outline of its development, and a listing of six priority areas for research. The NIH is committed to working with all stakeholder communities engaged in rehabilitation research to track progress made on these priorities and to work to advance the science of medical rehabilitation.This article is being published almost simultaneously in the following six journals: American Journal of Occupational Therapy, American Journal of Physical Medicine and Rehabilitation, Archives of Physical Medicine and Rehabilitation, Neurorehabilitation and Neural Repair, Physical Therapy, and Rehabilitation Psychology. Citation information is as follows: NIH Medical Rehabilitation Coordinating Committee. Am J Phys Med Rehabil. 2017;97(4):404-407.

Research needs for assessing iodine intake, iodine status, and the effects of maternal iodine supplementation

The Office of Dietary Supplements of the NIH convened 3 workshops on iodine nutrition in Rockville, Maryland, in 2014. The purpose of the current article is to summarize and briefly discuss a list of research and resource needs developed with the input of workshop participants. This list is composed of the basic, clinical, translational, and population studies required for characterizing the benefits and risks of iodine supplementation, along with related data, analyses, evaluations, methods development, and supporting activities. Ancillary studies designed to use the participant, biological sample, and data resources of ongoing and completed studies (including those not originally concerned with iodine) may provide an efficient, cost-effective means to address some of these research and resource needs. In the United States, the foremost question is whether neurobehavioral development in the offspring of mildly to moderately iodine-deficient women is improved by maternal iodine supplementation during pregnancy. It is important to identify the benefits and risks of iodine supplementation in all population subgroups so that supplementation can be targeted, if necessary, to avoid increasing the risk of thyroid dysfunction and related adverse health effects in those with high iodine intakes. Ultimately, there will be a need for well-designed trials and other studies to assess the impact of maternal supplementation on neurodevelopmental outcomes in the offspring. However, 2 basic information gaps loom ahead of such a study: the development of robust, valid, and convenient biomarkers of individual iodine status and the identification of infant and toddler neurobehavioral development endpoints that are sensitive to mild maternal iodine deficiency during pregnancy and its reversal by supplementation.

Assessing iodine intake, iodine status, and the effects of maternal iodine supplementation: introduction to articles arising from 3 workshops held by the NIH Office of Dietary Supplements

The NIH Office of Dietary Supplements (ODS) convened 3 workshops on iodine nutrition in 2014, each held in Rockville, Maryland. These workshops were part of the ongoing ODS Iodine Initiative, begun in 2011 in response to concerns that US pregnant women may be at risk of iodine deficiency and that a high fraction of prenatal dietary supplements do not contain the recommended amounts of iodine. The primary purpose of the workshops was to consider the data and resources necessary to evaluate the clinical and public health benefits and risks of maternal iodine supplementation in the United States. The first workshop focused on the assessment of iodine intake, the second focused on the assessment of iodine status, and the third focused on the design and interpretation of clinical trials of maternal iodine supplementation. Here we provide the background of the ODS Iodine Initiative, summarize the 3 workshops held in 2014, and introduce the articles that arose from the workshops and are published in this supplement issue.

The effect of gender on outcomes of aortoiliac artery interventions for claudication

OBJECTIVE

To explore the relationship between gender, native artery diameters, and outcomes of stent revascularization (ST) in the "Claudication: Exercise versus Endoluminal Revascularization" trial.

METHODS

A comparative analysis was performed of the impact of gender, age, weight, height, body mass index, and body surface area on revascularization outcomes at baseline and 6months in 55 arterial segments of aorta, common iliac artery, and external iliac artery (EIA).

RESULTS

Women demonstrated smaller diameter of the EIA. However, the clinical outcomes of revascularization were not negatively affected by the gender-based differences.

CONCLUSION

Gender-based differences are unlikely to significantly impact outcome of ST.

Update on Prevention of Cardiovascular Disease in Adults With Type 2 Diabetes Mellitus in Light of Recent Evidence: A Scientific Statement From the American Heart Association and the American Diabetes Association

Cardiovascular disease risk factor control as primary prevention in patients with type 2 diabetes mellitus has changed substantially in the past few years. The purpose of this scientific statement is to review the current literature and key clinical trials pertaining to blood pressure and blood glucose control, cholesterol management, aspirin therapy, and lifestyle modification. We present a synthesis of the recent literature, new guidelines, and clinical targets, including screening for kidney and subclinical cardiovascular disease for the contemporary management of patients with type 2 diabetes mellitus.

Update on Prevention of Cardiovascular Disease in Adults With Type 2 Diabetes Mellitus in Light of Recent Evidence: A Scientific Statement From the American Heart Association and the American Diabetes Association

Cardiovascular disease risk factor control as primary prevention in patients with type 2 diabetes mellitus has changed substantially in the past few years. The purpose of this scientific statement is to review the current literature and key clinical trials pertaining to blood pressure and blood glucose control, cholesterol management, aspirin therapy, and lifestyle modification. We present a synthesis of the recent literature, new guidelines, and clinical targets, including screening for kidney and subclinical cardiovascular disease for the contemporary management of patients with type 2 diabetes mellitus.

Monthly haemostatic factor variability in women and men

BACKGROUND

Hormonal status influences haemostatic factors including fibrinogen, factor VII and plasminogen activator inhibitor (PAI-1), and concentrations differ among men, premenopausal and postmenopausal women. This study examines how phases of the menstrual cycle influence variability of fibrinogen, factor VII and PAI-1.

DESIGN

We studied 103 subjects (39 premenopausal women, 18 postmenopausal women and 46 men) during three, randomized, 8-week energy- and nutrient-controlled experimental diets in the Dietary Effects on Lipids and Thrombogenic Activity (DELTA) Study. Fasting blood samples were collected weekly during the last 4 weeks of each diet period, and haemostatic factors were quantified. Two linear mixed-effects models were used for fibrinogen, factor VII and PAI-1: one to estimate and compare group-specific components of variance, and the other to estimate additional fixed effects representing cyclical functions of day of menstrual cycle in premenopausal women.

RESULTS

Systematic cyclical variation with day of menstrual cycle was observed for fibrinogen (P < 0.0001), factor VII (P = 0.0012) and PAI-1 (P = 0.0024) in premenopausal women. However, the amplitude of cycling was small relative to the total magnitude of intra-individual variability. In addition, the intra-individual variance and corresponding coefficient of variation observed in premenopausal women did not differ from postmenopausal women and men.

CONCLUSIONS

The variability in haemostatic factors in premenopausal women is no greater than for postmenopausal women or men. Consequently, premenopausal women can be included in studies investigating haemostatic factor responses without controlling for stage of menstrual cycle.

Obesity and hypertension interact to increase risk of renal cell carcinoma in Iowa, USA

SUMMARY

Renal cell carcinoma (RCC) rates in the US have risen, along with those of obesity and hypertension. We investigated the interactive relationship with obesity and hypertension (HT) through a population-based case-control study of RCC in Iowa consisting of 406 cases and 2434 controls. Data on height and weight at various ages and history of HT were collected and interaction tested by log-likelihood ratio tests. After adjustment, both obesity and HT were independently and interactively associated with increased RCC risk. Hypertensive subjects, obese (BMI ≥ 30) at age 40 were 4.2 (CI: 2.38-6.53) times more likely to develop RCC as normotensive individuals of normal weight (BMI < 25). A similar interactive pattern was observed for obesity at age 60 (p = 0.02). Interaction with obesity was more evident in women (pinteraction = 0.04 age 40, pinteraction = 0.01 age 60). Our findings suggest that maintaining body weight and/or controlling HT are strategies for preventing RCC.:

Expanding research to provide an evidence base for nutritional interventions for the management of inborn errors of metabolism

A trans-National Institutes of Health initiative, Nutrition and Dietary Supplement Interventions for Inborn Errors of Metabolism (NDSI-IEM), was launched in 2010 to identify gaps in knowledge regarding the safety and utility of nutritional interventions for the management of inborn errors of metabolism (IEM) that need to be filled with evidence-based research. IEM include inherited biochemical disorders in which specific enzyme defects interfere with the normal metabolism of exogenous (dietary) or endogenous protein, carbohydrate, or fat. For some of these IEM, effective management depends primarily on nutritional interventions. Further research is needed to demonstrate the impact of nutritional interventions on individual health outcomes and on the psychosocial issues identified by patients and their families. A series of meetings and discussions were convened to explore the current United States' funding and regulatory infrastructure and the challenges to the conduct of research for nutritional interventions for the management of IEM. Although the research and regulatory infrastructure are well-established, a collaborative pathway that includes the professional and advocacy rare disease community and federal regulatory and research agencies will be needed to overcome current barriers.

Virtual reality technologies for research and education in obesity and diabetes: research needs and opportunities

The rising rates, high prevalence, and adverse consequences of obesity and diabetes call for new approaches to the complex behaviors needed to prevent and manage these conditions. Virtual reality (VR) technologies, which provide controllable, multisensory, interactive three-dimensional (3D) stimulus environments, are a potentially valuable means of engaging patients in interventions that foster more healthful eating and physical activity patterns. Furthermore, the capacity of VR technologies to motivate, record, and measure human performance represents a novel and useful modality for conducting research. This article summarizes background information and discussions for a joint July 2010 National Institutes of Health - Department of Defense workshop entitled Virtual Reality Technologies for Research and Education in Obesity and Diabetes. The workshop explored the research potential of VR technologies as tools for behavioral and neuroscience studies in diabetes and obesity, and the practical potential of VR in fostering more effective utilization of diabetes- and obesity-related nutrition and lifestyle information. Virtual reality technologies were considered especially relevant for fostering desirable health-related behaviors through motivational reinforcement, personalized teaching approaches, and social networking. Virtual reality might also be a means of extending the availability and capacity of health care providers. Progress in the field will be enhanced by further developing available platforms and taking advantage of VR's capabilities as a research tool for well-designed hypothesis-testing behavioral science. Multidisciplinary collaborations are needed between the technology industry and academia, and among researchers in biomedical, behavioral, pedagogical, and computer science disciplines. Research priorities and funding opportunities for use of VR to improve prevention and management of obesity and diabetes can be found at agency websites (National Institutes of Health: http://grants.nih.gov/grants/guide/index.html; Department of Defense: www.tatrc.org).

Design of the multicenter standardized supervised exercise training intervention for the ‘CLaudication: Exercise Vs Endoluminal Revascularization (CLEVER) study’

Abstract

The CLaudication: Exercise Vs Endoluminal Revascularization (CLEVER) study is the first randomized, controlled, clinical, multicenter trial that is evaluating a supervised exercise program compared with revascularization procedures to treat claudication. In this report, the methods and dissemination techniques of the supervised exercise training intervention are described. A total of 217 participants are being recruited and randomized to one of three arms: (1) optimal medical care; (2) aortoiliac revascularization with stent; or (3) supervised exercise training. Of the enrolled patients, 84 will receive supervised exercise therapy. Supervised exercise will be administered according to a protocol designed by a central CLEVER exercise training committee based on validated methods previously used in single center randomized control trials. The protocol will be implemented at each site by an exercise committee member using training methods developed and standardized by the exercise training committee. The exercise training committee reviews progress and compliance with the protocol of each participant weekly. In conclusion, a multicenter approach to disseminate the supervised exercise training technique and to evaluate its efficacy, safety and cost-effectiveness for patients with claudication due to peripheral arterial disease (PAD) is being evaluated for the first time in CLEVER. The CLEVER study will further establish the role of supervised exercise training in the treatment of claudication resulting from PAD and provide standardized methods for use of supervised exercise training in future PAD clinical trials as well as in clinical practice.

Environmental influences on development of type 2 diabetes and obesity: challenges in personalizing prevention and management

Recent epidemic increases in the U.S. prevalence of obesity and diabetes are a consequence of widespread environmental changes affecting energy balance and its regulation. These environmental changes range from exposure to endocrine disrupting pollutants to shortened sleep duration to physical inactivity to excess caloric intake. Overall, we need a better understanding of the factors affecting individual susceptibility and resistance to adverse exposures and behaviors and of determinants of individual response to treatment. Obesity and diabetes prevention will require responding to two primary behavioral risk factors: excess energy intake and insufficient energy expenditure. Adverse food environments (external, nonphysiological influences on eating behaviors) contribute to excess caloric intake but can be countered through behavioral and economic approaches. Adverse built environments, which can be modified to foster more physical activity, are promising venues for community-level intervention. Techniques to help people to modulate energy intake and increase energy expenditure must address their personal situations: health literacy, psychological factors, and social relationships. Behaviorally oriented translational research can help in developing useful interventions and environmental modifications that are tailored to individual needs.

Novel engineering approaches to obesity, overweight, and energy balance: public health needs and research opportunities

The obesity epidemic is one of the most rapidly evolving public health problems of our day. At present, 2/3 of American adults and 1/6 of American children and adolescents are considered either overweight or obese. Public health concern about obesity is high and reflects documented increased risk of cardiovascular disease, type 2 diabetes, many forms of cancer, gallbladder disease, and osteoarthritis, and increased mortality from these ailments, especially among the most obese. Innovative engineering technologies are needed to address a large range of problems in energy balance, intake, and expenditure that are associated with the obesity epidemic. Excess adipose tissue, representing fat storage, ultimately derives from an imbalance between energy intake and energy expenditure. Novel sensors, devices, imaging technologies, nanotechnology, biomaterials, and other approaches need to be developed and evaluated through multidisciplinary collaborations between engineers, physical scientists, and scientists with expertise in obesity and nutrition. The goal is to encourage research to develop useful technologies and tools to facilitate research and eventually to support therapeutic advances and behavioral change. Furthermore, the possibility of re-engineering the "built environment" to encourage higher levels of physical activity has been suggested as another promising and important approach to which engineers can contribute (see http://www.obesityresearch.nih.gov).

Engineering approaches to energy balance and obesity: opportunities for novel collaborations and research: report of a joint national science foundation and national institutes of health workshop

Energy balance disorders account for a large public health burden. The obesity epidemic in particular is one of the most rapidly evolving public health problems of our day. At present, two-thirds of American adults and one-sixth of American children and adolescents are considered either overweight or obese. Public health concern about obesity is high because of the increased risk and increased mortality of cardiovascular disease, Type 2 diabetes, many forms of cancer, gallbladder disease, and osteoarthritis. These risks increase with the severity of the obesity. Excess adipose tissue, representing fat storage, ultimately derives from an imbalance between energy intake and energy expenditure. Conversely, undesirable and inadvertent loss of body weight and muscle mass, as seen in aging and cachectic states of chronic diseases such as heart failure and cancer, have serious clinical and functional consequences without satisfactory clinical or behavioral solutions. Innovative engineering technologies could help to address unresolved problems in energy balance, intake, and expenditure. Novel sensors, devices, imaging technologies, nanotechnologies, biomaterials, technologies to detect biochemical markers of energy balance, mathematical modeling, systems biology, and other approaches could be developed, evaluated, and leveraged through multidisciplinary collaborations. Engineers, physical scientists, and mathematicians can work with scientists from other relevant disciplines who possess expertise in obesity and nutrition. Furthermore, the possibility of re-engineering the "built environment" to encourage higher levels of physical activity has been suggested as another promising and important approach to which engineers can contribute (see http://www.obesityresearch.nih.gov). Ultimately, systematic application of the "Engineering Approach" can help in developing the needed technologies and tools to facilitate research and eventually support therapeutic advances and behavioral change. This article summarizes important public health concerns related to disordered energy balance and describes research priorities identified at a recent National Science Foundation-National Institutes of Health workshop. Research funding opportunities are described as posted on the NIH Guide to Grants and Contracts (see http://www.nih.gov/grants/guide).

Dietary guidance in heart failure: a perspective on needs for prevention and management

The role that dietary factors play in preventing heart failure (HF) and in improving prognosis is increasingly recognized, indicating a need for well-grounded guidelines that can provide recommendations for daily nutrient intakes. At present, however, the state of dietary guidance is more satisfactory for persons at risk of HF (Stages A and B) than for those with a diagnosis of HF (Stages C and D). For individuals at risk of HF, a good starting point is provided by governmental and professional society guidance directed at dietary management of cardiovascular risk factors such as hypertension, hyperlipidemia, and obesity. These dietary recommendations are consonant with epidemiologic research suggesting that improving risk factor profiles likely will lower the risk of developing HF. For patients with diagnosed HF, however, little information is available to define optimal nutrient intakes and optimal food patterns. Dietary services have been shown useful in improving clinical outcomes, but nutritional management must be individualized to the patient's needs and must accommodate pharmacologic therapy, multiple co-morbidities, the possible need for nutritional supplements, repeated hospitalizations, salt and fluid retention, voluntary vs. involuntary weight loss, and other nutritional issues relevant to the aged population who comprise the majority of HF patients. Progress in the field will require well-designed clinical investigations addressing nutrient intake, nutrient metabolism, and nutritional status while mindful of the complex pathophysiology of HF.

An overview of methodologies, proficiencies, and training resources for controlled feeding studies

Dietary intervention studies of human beings produce valuable information regarding dietary effects on biological processes and risk factors for chronic diseases. Using the well-controlled feeding approach, participants consume only foods that have been precisely prepared in a research kitchen, whereas in behavioral counseling studies, participants self-select their foods within guidelines. Because controlled feeding studies meticulously control experimental diets, they are intellectually and logistically challenging to conduct. They afford exciting opportunities for dietetic professionals in designing protocols, developing budgets, and collaborating in multidisciplinary research teams. Research dietitians use food composition data and chemical analysis of menus to prepare research diets with precision. They determine the energy requirements of subjects and adjust diets as required, most often for weight maintenance, throughout the study. All people involved in research must be attentive to the ethical treatment of the study participants while motivating them to adhere to the protocol requirements. Dietitians possess many of these skills, but may require training specific to well-controlled feeding studies. Information related to the conduct of controlled feeding studies has recently become more accessible. We provide an overview of well-controlled feeding study methodologies, proficiencies for planning and implementing these studies, and training resources.

Gender, alcohol consumption, and renal cell carcinoma

The nature of the association between alcohol consumption and renal cell carcinoma (RCC) is not well understood, but there are indications of effect modification by gender. The authors report data from a population-based case-control study conducted in Iowa from 1986 to 1989. RCC cases (261 men and 145 women) were identified through the Iowa Cancer Registry, while controls (1,598 men and 831 women) were randomly selected from the general population, frequency matched on age and gender. Subjects provided detailed information on a mailed questionnaire regarding demographic, anthropometric, lifestyle, dietary, and medical history risk factors. In age-adjusted analysis, there was a decrease in risk for women who reported consuming more than three servings (median among drinkers) of alcohol per week (odds ratio = 0.5, 95% confidence interval: 0.2, 0.9) compared with never drinkers. No evidence of an association among men was noted (odds ratio = 1.1, 95% confidence interval: 0.8, 1.5). Multivariate adjustment for anthropometric, lifestyle, smoking, and dietary factors did not alter the findings. Analysis by type of alcohol suggested that the inverse association was strongest for beer consumption, but estimates were imprecise. These findings suggest an inverse association of alcohol consumption and RCC development among women but not among men.

Accuracy of energy intake data estimated by a multiple-pass, 24-hour dietary recall technique

OBJECTIVE

This study examined the accuracy of a multiple-pass, 24-hour dietary recall method for estimating energy intakes of men and women by comparing it with energy intake required for weight maintenance.

DESIGN

Three-day, multiple-pass, 24-hour recalls were obtained on randomly selected days during a self-selected diet period when subjects were preparing their own meals and during a controlled diet period when all meals were provided by the study. During the dietary intervention, weight was maintained; body weight and dietary intake were monitored closely, thereby allowing estimation of the energy intake required for weight maintenance.

SUBJECTS/SETTING

Seventy-eight men and women (22 to 67 years old) from the Dietary Effects on Lipoprotein and Thrombogenic Activity (DELTA) study participated in this study. All 24-hour recalls were collected using a computer-assisted, interactive, multiple-pass telephone interview technique. Energy requirements for each individual were determined by the energy content of the DELTA study foods provided to maintain weight.

STATISTICAL ANALYSIS

Paired and independent t tests were conducted to examine differences among study variables. Agreement between recalled energy intake and weight maintenance energy intake was analyzed using the Bland-Altman technique.

RESULTS

Compared with weight maintenance energy intake, during the self-selected diet period men and women underestimated energy intake by 11% and 13%, respectively. During the controlled diet period, men underestimated energy intake by 13%, whereas women overestimated energy by 1.3%.

APPLICATIONS/CONCLUSIONS

Men had a tendency to under-estimate energy intake irrespective of the recording period. The accuracy of the recalled energy intake of women may be influenced by recording circumstances. Researchers should examine the factors influencing underreporting and overreporting by individuals and their impact on macronutrient and micronutrient intakes. Also, strategies need to be developed to minimize underreporting and overreporting.

Linxian nutrition intervention trials. Design, methods, participant characteristics, and compliance

Two nutrition intervention trials were conducted in Linxian, China, where the esophageal/gastric cardia cancer mortality rates are among the highest in the world and there is suspicion that the population's chronic deficiencies of multiple nutrients are etiologically involved. Both trials were randomized, double-blind, and placebo-controlled, and tested the effect of multiple-vitamin and multiple-mineral supplements in lowering the rates of cancer. In the first trial, the Dysplasia Trial, 3318 individuals with a cytologic diagnosis of esophageal dysplasia received daily vitamin and mineral supplements or placebos for 6 years. The second trial, the General Population Trial, involved 29,584 individuals and used a one-half replicate of a 2(4) fractional factorial design, which enabled the testing of daily supplementation of four different vitamin and mineral combinations and placebo for a period 5 1/4 years. This article describes the design and methods of these studies as well as the baseline characteristics and compliance behavior of the participants in these two trials, the largest cancer chemoprevention studies reported to date.

Nutrition intervention trials in Linxian, China: multiple vitamin/mineral supplementation, cancer incidence, and disease-specific mortality among adults with esophageal dysplasia

BACKGROUND

A number of vitamins and minerals have been shown to influence carcinogenesis in experimental animals. In humans, epidemiologic evidence suggests that intake of fruits and vegetables may reduce risk of esophageal and other cancers. Vitamins and minerals in these foods may contribute to the reduced cancer risk. The people of Linxian, China, have persistently low intake of multiple nutrients and exhibit one of the world's highest rates of esophageal/gastric cardia cancer, with an exceptionally high risk of esophageal dysplasia.

PURPOSE

To determine whether supplementation with multiple vitamins and minerals may reduce esophageal/gastric cardia cancer among persons with esophageal dysplasia, we conducted a 6-year prospective intervention trial in Linxian.

METHODS

Mortality and cancer incidence were ascertained from May 1985 through May 1991 for 3318 persons with cytologic evidence of esophageal dysplasia who were randomly assigned to receive, throughout that period, daily supplementation with 14 vitamins and 12 minerals or placebo. Doses were typically two to three times U.S. Recommended Daily Allowances. Compliance was assessed by counting unused pills monthly for all trial participants and by assaying nutrient levels in blood collected from samples of individuals randomly selected without replacement every 3 months throughout the trial. Cancers were identified through routine surveillance and by special cytology and endoscopy screenings after 2 1/2 years and 6 years.

RESULTS

A total of 324 deaths occurred during the 6-year intervention period; 167 occurred in the control (placebo) group and 157 occurred in the supplement group. Cancer was the leading cause of death (54% of all deaths); 18% were due to cerebrovascular diseases and 29% to other causes. Cumulative esophageal/gastric cardia death rates were 8% lower (relative risk [RR] = 0.92; 95% confidence interval [CI] = 0.67-1.28) among individuals receiving supplements rather than placebo, a nonsignificant (P > .10) difference. Risk of total mortality was 7% lower (RR = 0.93; 95% CI = 0.75-1.16; P > .10), total cancer 4% lower (RR = 0.96; 95% CI = 0.71-1.29; P > .10), cerebrovascular disease 38% lower (RR = 0.62; 95% CI = 0.37-1.06; P = .08), and other diseases 12% higher (RR = 1.12; 95% CI = 0.74-1.69; P > .10) among the treated group. Cumulative cancer incidence rates were nearly the same in the two groups.

CONCLUSIONS

No substantial short-term beneficial effect on incidence or mortality for this type of cancer occurred following daily supplementation with multiple vitamins and minerals among adults with precancerous lesions of the esophagus.

IMPLICATIONS

Although no statistically significant short-term benefits were observed, longer follow-up should be more informative about the effectiveness of this 6-year supplementation on cancer and other diseases among individuals with esophageal dysplasia.

Intake of tapwater and total water by pregnant and lactating women

BACKGROUND

Despite theoretically higher requirements for water due to physiologic demands of pregnancy and lactation, little is known of actual ranges of intake in pregnant and lactating women.

METHODS

Population-based estimates of total water and tapwater intake in women of reproductive age were derived using data from the 1977-78 USDA Nationwide Food Consumption Survey. Three-day average intakes were calculated for 188 pregnant women, 77 lactating women, and 6,201 non-pregnant, non-lactating control women.

RESULTS

Total water intake (mean +/- SD) was 1,940 +/- 686 g/day (median 1,835) for control women, 2,076 +/- 743 g/day (median 1,928) for pregnant women and 2,242 +/- 658 g/day (median 2,164) for lactating women. Tapwater intake was 1,157 +/- 635 g/day (median 1,065) for control women, 1,189 +/- 699 g/day (median 1,063) for pregnant women, and 1,310 +/- 591 g/day (median 1,330) for lactating women. Total water intake was equal to or greater than 3,000 g/day among 7 percent of control women, 11 percent of pregnant women, and 13 percent of lactating women. Tapwater intake was equal to or greater than 2,000 g/day among 10 percent of control women, 15 percent of pregnant women, and 8 percent of lactating women.

CONCLUSIONS

These results should be useful in estimating amounts of nutrients and toxic substances that women of reproductive age obtain through the water supply.

Lung cancer among women in north-east China

A case-control study of lung cancer involving interviews with 965 female patients and 959 controls in Shenyang and Harbin, two industrial cities which have among the highest rates of lung cancer in China, revealed that cigarette smoking is the main causal factor and accounted for about 35% of the tumours among women. Although the amount smoked was low (the cases averaged eight cigarettes per day), the percentage of smokers among women over age 50 in these cities was nearly double the national average. Air pollution from coal burning stoves was implicated, as risks of lung cancer increased in proportion to years of exposure to 'Kang' and other heating devices indigenous to the region. In addition, the number of meals cooked by deep frying and the frequency of smokiness during cooking were associated with risk of lung cancer. More cases than controls reported workplace exposures to coal dust and to smoke from burning fuel. Elevated risks were observed for smelter workers and decreased risks for textile workers. Prior chronic bronchitis/emphysema, pneumonia, and recent tuberculosis contributed significantly to lung cancer risk, as did a history of tuberculosis and lung cancer in family members. Higher intake of carotene-rich vegetables was not protective against lung cancer in this population. The findings were qualitatively similar across the major cell types of lung cancer, except that the associations with smoking and previous lung diseases were stronger for squamous/oat cell cancers than for adenocarcinoma of the lung.

Smoking, air pollution, and the high rates of lung cancer in Shenyang, China

A case-control study involving interviews with 1,249 patients with lung cancer and 1,345 population-based controls was conducted in Shenyang, an industrial city in northeastern China, where mortality rates are high among men and women. Cigarette smoking was found to be the principal cause of lung cancer in this population, accounting for 55% of the lung cancers in males and 37% in females. The attributable risk percentage among females is high compared to elsewhere in China, largely because of a higher prevalence of smoking among women. After adjustment for smoking, there were also significant increases in lung cancer risk associated with several measures of exposure to air pollutants. Risks were twice as high among those who reported smoky outdoor environments, and increased in proportion to years of sleeping on beds heated by coal-burning stoves (kang), and to an overall index of indoor air pollution. Threefold increases in lung cancer risk were found among men who worked in the nonferrous smelting industry, where heavy exposures to inorganic arsenic have been reported. The associations with both smoking and indoor air pollution were stronger for squamous cell and small cell carcinomas than for adenocarcinoma of the lung. Risks due to smoking or air pollution were not greatly altered by adjustment for consumption of fresh vegetables or sources of beta carotene or retinol, prior chronic lung diseases, or education level. The findings suggest that smoking and environmental pollution combine to account for the elevated rates of lung cancer mortality in Shenyang.

Gestational trophoblastic disease: a case-control study from the People's Republic of China

A case-control study involving 331 patients with complete hydatidiform mole and 662 community controls matched to the cases on age and timing of pregnancy was conducted in Beijing, China. A history of a term birth was associated with reduced risk (odds ratio = 0.6, 95% confidence interval 0.4 to 0.9), with some evidence of further decrease with multiple births. Previous spontaneous abortions were not related to risk, although those with a prior induced abortion were at elevated risk, particularly if two or more abortions were involved (odds ratio = 2.8, 95% confidence interval 1.4 to 5.7). A history of having sought medical advice for infertility was associated with reduced risk (odds ratio = 0.5, 95% confidence interval 0.2 to 0.8), but those who reported use of herbal medicines during a first trimester of a previous pregnancy were at excess risk (odds ratio = 2.2, 95% confidence interval 1.3 to 3.6). In addition, a statistically significant trend in risk was observed with years of oral contraceptive use (odds ratio = 2.6, 95% confidence interval 0.9 to 6.9 for greater than or equal to 4 years of use). Dietary habits and family histories of cancer or trophoblastic disease were not related to risk in this study.

A case-control study of cancer of the esophagus and gastric cardia in Linxian

A case-control study involving interviews with 1,244 patients (758 males and 486 females) with cancer of the esophagus or gastric cardia and 1,314 population-based controls (789 males, 525 females) was carried out in Linxian, a rural county in North Central China with one of the world's highest mortality rates for these tumors. Cancer risks tended to rise with increasing intake of wheat and corn, but no association was found with adult intake of pickled vegetables, the leading a priori suspect, and risks were not elevated among those consuming low quantities of fresh vegetables or fruits. Few differences in preparation or storage of food or water were detected, although cancer patients reported less fluid intake than controls. Few persons reported drinking alcoholic beverages. Smoking was reported by 61% of the male cases and was a mild risk factor, related more to cancer of the cardia than of the esophagus. The risk was increased by 70% among those whose parents had esophageal or stomach cancer, but only slightly among those whose spouses had such cancers, suggesting that exposure early in life and/or genetic effects may be involved.

Depressed PMNC blastogenic response in patients with cancer of the head and neck: a study of IL-2 production, IL-2 consumption, and IL-2 receptor expression

Approximately two thirds of patients with head and neck cancer have been shown to have peripheral mononuclear cells that exhibit a lowered blastogenic response to the T-cell mitogens, concanavalin A and phytohemagglutinin. To investigate the possible mechanisms of this phenomenon, we measured the amount of activated T-cell lymphokine interleukin-2 present in the supernatant of concanavalin A- or phytohemagglutinin-stimulated peripheral mononuclear cells taken from patients with squamous cell carcinoma of the upper aerodigestive tract. Concentrations were found that were similar to those of healthy subjects. The rate of interleukin-2 consumption and the degree of interleukin-2 receptor expression also were similar for patients and controls. In the course of these experiments, it was noted that differences in blastogenic response between patients and controls were abolished when, 24 hours after the beginning of either concanavalin A or phytohemagglutinin stimulation, the culture supernatant was removed and replaced by fresh medium, containing recombinant interleukin-2 to further sustain cell growth. This suggests that the lower blastogenic response found in patients with head and neck cancer is not due to global immune unresponsiveness, but instead, is caused by selective cell dysfunction(s), which may include the production of a suppressor factor following concanavalin A or phytohemagglutinin stimulation.

Environmental factors and high risk of esophageal cancer among men in coastal South Carolina

A case-control study involving interviews of 207 men with esophageal cancer and 422 control subjects or their next of kin was conducted to identify reasons for the unusually high rates of esophageal cancer among men in coastal South Carolina. Tobacco and alcohol, including moonshine, were identified as the major determinants of esophageal cancer risk. Increased risk was also associated with low intake of fresh fruits but not with drinking of local herbal teas. The findings suggest that efforts aimed at reducing tobacco and alcohol use will help to lower the elevated rates of esophageal cancer in coastal South Carolina.

Dietary factors in oral and pharyngeal cancer

A population-based case-control study of oral and pharyngeal cancer conducted in four areas of the United States provided information on a number of risk factors, including diet. Interviews were obtained from 871 oral cancer patients and 979 controls among whites, frequency matched for age and sex. Consumption frequency of 61 food items was assessed in the questionnaire; attention was given to foods that are sources of vitamins A and C and carotene. The major finding was an inverse relationship between fruit intake and risk of oral and pharyngeal cancer; individuals in the highest quartile of intake had about half the risk of those in the lowest quartile. Vitamin C, carotene, or fiber in fruit did not appear to account completely for this relationship, since these nutrients in vegetables did not provide similar protection. This finding suggests the influence of other constituents in fruits, although it is possible that cooking vegetables may have a nutrient-diminishing effect. Dietary intake of other nutrients, such as the B vitamins, vitamin E, folate, and iron, showed no consistent relationship to risk of oral and pharyngeal cancer. Coffee or other hot beverage consumption did not increase risk; intake of nitrite-containing meats or cooking practices, such as smoking, pickling, or charcoal grilling, also did not increase risk. All analyses were adjusted for the effects of tobacco and alcohol, strong risk factors for oral and pharyngeal cancer. Dietary findings among the few subjects who did not use tobacco or alcohol were similar to those for all subjects.

Diet and high risk of stomach cancer in Shandong, China

A case-control investigation involving interviews with 564 stomach cancer patients and 1131 population-based controls was conducted to evaluate reasons for the exceptionally high rates of stomach cancer in Linqu, a rural county in Shandong Province in northeast China. Daily consumption of sour pancakes, a fermented indigenous staple, was associated with a 30% increase in risk. Risks of stomach cancer were also increased by 2- to 3-fold among persons with prior chronic gastritis or gastric ulcer, by 80% among those with stomach cancer in a family member, by 50% among men who smoked one or more packs of cigarettes/day, by 40% among those who preferred salty foods, and by 50% among families with moldy grain supplies. In contrast, risks tended to decrease in proportion to increasing consumption of fresh vegetables and fruits. This protective effect was more pronounced for vegetables, with those in the highest quartile of intake at less than one-half the risk of those in the lowest. Stomach cancer risks also declined with increasing dietary intake of carotene, vitamin C, and calcium, but not retinol. These findings provide leads to dietary factors that contribute to the high rates in Linqu, where stomach cancer is the leading cause of cancer and has not yet begun to decline as in other parts of the world.

Effects of heparin on in vitro immune parameters

The effects of heparin on several in vitro immune functions [blastogenesis, interleukin-2(IL-2) production] were investigated. The addition of heparin to human peripheral mononuclear cells stimulated with phytohemagglutinin or pokeweed mitogen significantly increased the blastogenic response of these cells. Peak IL-2 concentrations in the supernatant of heparin-containing cultures were two- to fourfold higher than in heparin-free cultures. Flow cytometry experiments revealed that Leu-M3-positive cells were the only subset to be significantly affected by heparin, which induced an increase both in number and in fluorescence intensity of Leu-M3-positive cells. In contrast, the expression of DR molecules on monocytes was slightly decreased. It is speculated that the observed antimetastatic effects of heparin may be exerted through local immunomodulation in macrophage-rich tissues.

Sample size and power for case-control studies when exposures are continuous

In estimating the sample size for a case-control study, epidemiologic texts present formulae that require a binary exposure of interest. Frequently, however, important exposures are continuous and dichotomization may result in a 'not exposed' category that has little practical meaning. In addition, if risks vary monotonically with exposure, then dichotomization will obscure risk effects and require a greater number of subjects to detect differences in the exposure distributions among cases and controls. Starting from the usual score statistic to detect differences in exposure, this paper develops sample size formulae for case-control studies with arbitrary exposure distributions; this includes both continuous and dichotomous exposure measurements as special cases. The score statistic is appropriate for general differentiable models for the relative odds, and, in particular, for the two forms commonly used in prospective disease occurrence models: (1) the odds of disease increase linearly with exposure; or (2) the odds increase exponentially with exposure. Under these two models we illustrate calculation of sample sizes for a hypothetical case-control study of lung cancer among non-smokers who are exposed to radon decay products at home.

Lung cancer among Chinese women

A case-control study involving interviews with 672 female lung cancer patients and 735 population-based controls was conducted to investigate the high rates of lung cancer, notably adenocarcinoma, among women in Shanghai. Cigarette smoking was a strong risk factor, but accounted for only about one-fourth of all newly diagnosed cases of lung cancer. Most patients, particularly with adenocarcinoma, were life-long non-smokers. The risks of lung cancer were higher among women reporting tuberculosis and other pre-existing lung diseases. Hormonal factors were suggested by an increased risk associated with late menopause and by a gradient in the risk of adenocarcinoma with decreasing menstrual cycle length, with a 3-fold excess among women who had shorter cycles. Perhaps most intriguing were associations found between lung cancer and measures of exposure to cooking oil vapors. Risks increased with the numbers of meals cooked by either stir frying, deep frying or boiling; with the frequency of smokiness during cooking; and with the frequency of eye irritation during cooking. Use of rapeseed oil, whose volatiles following high-temperature cooking may be mutagenic, was also reported more often by the cancer patients. The findings thus confirm that factors other than smoking are responsible for the high risk of lung cancer among Chinese women and provide clues for further research, including the assessment of cooking practices.

Growth in black and white children with Down syndrome

Growth in 28 black and 30 white children with Down syndrome was compared at birth, 4 months, 1 year, and 7 years. Weight, length, and head circumference measurements were taken from case records of the U.S. Collaborative Perinatal Project. A multivariate regression model was used to examine simultaneously the effects on these measurements of sex, race, presence of congenital heart disease, maternal smoking during pregnancy, and maternal weight at delivery. Results showed that black and white children with Down syndrome have essentially identical growth rates and that long-term growth of these children may be responsive to external influences, such as maternal smoking and maternal weight at delivery.

A case-control study of esophageal cancer in Linxian, People's Republic of China

A case-control study involving interviews with 1,200 patients with esophageal cancer and 1,200 population-based controls has been initiated in Linxian, a county in North Central China with perhaps the world's highest mortality rates for this tumor. Here we describe the rationale, study methods, and results of a pilot study that established the feasibility of the investigation.

Nutritional status of the high esophageal cancer risk population in Linxian, People's Republic of China: effects of vitamin supplementation

Plasma levels of nutrients in 196 individuals were assayed as part of a study of the feasibility of a nutrition intervention trial in Linxian, a county in North Central China with exceptionally high rates of esophageal cancer. High-performance liquid chromatography analyses of samples collected in April 1983 showed low (relative to United States standards) base-line levels for retinol, alpha-tocopherol, and beta- and alpha-carotene. Repeat sampling in August 1983 revealed significantly increased plasma levels of retinol and alpha-tocopherol among those who had in the interim received daily supplementation with multivitamin pills containing the Recommended Dietary Allowance levels of those nutrients but not among those without supplementation. Levels of carotenes, which were not included in the pills, tended to increase regardless of supplementation, consistent with seasonal variations in availability of carotenoid-containing foods. Atomic absorption spectrophotometry analyses showed essentially normal levels of copper and zinc in plasma. Neither was affected by vitamin supplementation (the pills did not contain minerals) nor seasonal variation. The data are generally consistent with prior biochemical surveys in indicating marginal or low status of several nutrients in Linxian and in showing that supplementation with vitamins can effectively raise blood nutrient levels.

A case-control study of trophoblastic diseases in the People's Republic of China

A case-control study is currently under way in Beijing, People's Republic of China, involving approximately 165 patients with invasive moles or choriocarcinoma, 165 with hydatidiform moles, and 330 population controls, who were matched to the patients with invasive moles or choriocarcinoma on age and interval since last pregnancy. The interviews are focused on a number of suspected risk factors, including previous pregnancy outcomes, history of hydatidiform mole, medical factors, drug usage, family history, and diet. A brief background of the study and methods as established through a previous pilot study are given.

A pilot vitamin intervention trial in Linxian, People's Republic of China

A 24-week pilot study of daily or weekly multiple vitamin supplementation among 852 adults in Linxian, where the rate of esophageal cancer is exceptionally high, demonstrated the feasibility of an intervention trial in this population. Compliance, when judged by pill count, was high for both frequencies of pill use. Only 2% of the subjects refused to take any pills, and, among pill takers, over 95% were reported to be taking most of their pills at the end of the study. Biochemical confirmation of high compliance was demonstrated in urine and blood tests, which showed markedly improved vitamin levels after supplementation. Results of the pilot study indicated that a system in which barefoot doctors were used in pill distribution was effective and that established field operating procedures for a full-scale intervention trial in this area were acceptable.

Nonspecific immunity and head and neck cancer: blastogenesis reviewed and revisited

The present study suggests a correlation between concanavalin A-driven blastogenesis and the clinical course of head and neck cancer. Blastogenesis assays were conducted on peripheral blood lymphocytes from controls and from patients with squamous cell carcinoma (SCC) of the head and neck. Our results indicated that 3H-thymidine incorporation in response to concanavalin A and phytohemagglutinin stimulation were significantly lower for patients' than for controls' lymphocytes, whereas PWM stimulation was not statistically different in these two groups. Differences between patients and controls were most notable with concanavalin A stimulation. Five of seventeen patients had a response to concanavalin A stimulation that was in the normal range when expressed as relative to control values. The clinical course of these five patients seems to point to a better prognosis than that of the remaining patients who had below-normal mitogenic responses.