Importance of public-private partnerships for nutrition support research: An ASPEN Position Paper

Parenteral and enteral nutrition support are key components of care for various medical and physiological conditions in infants, children, and adults. Nutrition support practices have advanced over time, driven by the goals of safe and sufficient delivery of needed nutrients and improved patient outcomes. These advances have been, and continue to be, dependent on research and development studies. Such studies address aspects of enteral and parenteral nutrition support: formulations, delivery devices, health outcomes, cost-effectiveness, and related metabolism. The studies are supported by public funding from the government and by private funding from foundations and from the nutrition support industry. To build public trust in nutrition support research findings, it is important to underscore ethical research conduct and reporting of results for all studies, including those with industry sponsors. In 2019, American Society for Parenteral and Enteral Nutrition's (ASPEN's) Board of Directors established a task force to ensure integrity in nutrition support research that is done as collaborative partnerships between the public (government and individuals) and private groups (foundations, academia, and industry). In this ASPEN Position Paper, the Task Force presents principles of ethical research to guide administrators, researchers, and funders. The Task Force identifies ways to curtail bias and to minimize actual or perceived conflict of interests, as related to funding sources and research conduct. Notably, this paper includes a Position Statement to describe the Task Force's guidance on Public-Private Partnerships for research and funding. This paper has been approved by the ASPEN Board of Directors.

Adherence to Dietary Guidelines in Adults by Diabetes Status: Results From the 2012 Mexican National Health and Nutrition Survey

The aims of the present study were to compare the adherence to dietary guidelines and evaluate potential differences in nutrient profiles among adults by diabetes status. We used the Mexican Alternate Healthy Eating Index (MxAHEI) to evaluate adherence to dietary guidelines. We calculated the MxAHEI scores (total and by dietary component) with scales from 0 (non-adherence) to 100 (perfect adherence) based on a food frequency questionnaire. Mean daily intakes of macronutrients and micronutrients (g, mg, mcg/1000 kcal per day) were also estimated by diabetes status. Sex-specific, multivariable linear regression models were estimated to test whether MxAHEI scores as well as nutrient intakes were different by diabetes status. Mexican adults had low adherence to the dietary guidelines irrespective of their diabetes status (score < 50 points). Among men, the MxAHEI score was 2.6 points higher among those with diabetes than those without diabetes (46.9; 95% confidence intervals (CI): 44.6, 49.2 vs. 44.3; 95% CI: 44.2, 45.6, respectively). Among women, the total MxAHEI score was similar in individuals with diabetes compared to those without diabetes. Lower intakes of carbohydrates and added sugars and higher intakes of protein, calcium, and zinc were observed in individuals with diabetes. Our findings support the development of strategies focused on promoting dietary patterns that can help to prevent and control the disease.

Would You Want to Be What You Eat? Food Behaviors Associate with Diabetes Status in U.S. Adults

Objectives

Diabetes and prediabetes are a major public health concern in the United States. It is unknown how food-related behaviors are influenced by diabetes status. Therefore this study assessed the association between diabetes status and food behaviors (meal preparation, food procurement, and food spending) among U.S. adults.

Methods

Data from 8799 adults from the 2005–2016 National Health and Nutrition Examination Survey were categorized by glycated hemoglobin levels (A1c%): nondiabetes (&lt;5.7%; n = 5455), prediabetes (5.7–6.4%; n = 2273), and diabetes (&gt;6.5%; n = 1071). A1c levels were compared with meal preparation, food procurement, and spending data. Age-adjusted analyses for total and by sex (n = 4481 females and n = 4318 males) were performed.

Results

All adults (P = 0.002) and males (P = 0.001) with diabetes and prediabetes spent less money dining out than those without diabetes. Those with diabetes had a significantly further distance to grocery stores among the adult (P = 0.018) and male samples (P = 0.032). Females with diabetes spent more on carryout/delivered foods (P = 0.025) and ate fewer meals per week with family (P = 0.039) than those without diabetes. Females with diabetes were less likely to serve as the main food shoppers (P = 0.012) and males with diabetes were less likely to share meal planning/preparation responsibilities (P = 0.034).

Conclusions

Diabetes status associates with meal preparation, food procurement, and spending behaviors, and differs for males and females. These findings support the importance of addressing the behavioral context of food choices to help support a healthier diet and lifestyle for all adults.

Funding Sources

Abbott Nutrition.

Macronutrient and Micronutrient Intakes, and Dietary Patterns in Adults by Diabetes Status: Results from the 2012 Mexican National Health and Nutrition Survey

Objectives

To compare the intake of macronutrients, micronutrients, and dietary patterns between Mexican adults with and without diabetes.

Methods

Design: We calculated the mean intakes and adequacies of energy, macronutrients and micronutrients, and factor analysis was used to identify dietary patterns. We computed sex-specific, age- and energy-adjusted and fully-adjusted linear regression models to test whether nutrient intakes and dietary patterns scores were different by diabetes status. Setting: Mexico Participants: Mexican men (n 1142) and women (n 1620) participating in the Mexican National Health and Nutrition Survey 2012.

Results

The energy intake from carbohydrates and added sugars was lower in men and women with diabetes than in men and women without diabetes, but slightly above the recommended among adults with diabetes. Men with diabetes consumed more protein, total, monounsaturated and saturated fatty acids, vitamin D, calcium, and potassium than men without diabetes. The score for the prudent pattern and basic dietary pattern was 0.49 higher and 0.35 lower, respectively, among men with diabetes versus men without diabetes (P &lt; 0.05). Among women, there was no difference in the three dietary patterns (prudent, basic, and industrialized) by diabetes status.

Conclusions

Mexican adults with diabetes, especially men, had better daily nutrient intake and dietary pattern profiles than adults without diabetes. However, intakes of several nutrients are still inadequate in a large proportion of individuals with diabetes. It is pivotal to assure the dietary recommendations are given considering the potential differences by gender to improve the prevention, management, and control of the diabetes.

Funding Sources

This secondary data analysis was funded through a research grant from Abbott Nutrition.

Skipping Breakfast Is Associated with Diet Quality and the Distribution of Food Intake Throughout the Day: NHANES 2005–20016

Objectives

Distribution of carbohydrate intakes (carb choices) throughout the day are an important aspect to diabetes management and reducing blood glucose spikes. Skipping breakfast represents a behavior of concern, providing an extension of the overnight fast and may result in elevated sugar levels later in the day. Therefore, the purpose of this study was to evaluate dietary intake differences, including carbohydrates, based on consuming breakfast or not, and by diabetes status.

Methods

Adults over 30 years from NHANES 2005–2016 were classified into nondiabetes (HbA1c &lt;5.7%, n = 14,701), prediabetes (HbA1c 5.7–6.4%, n = 5855) and diabetes (HbA1c (≥6.5%, n = 2881). Dietary intakes were assessed using a multiple pass 24-hour recall to estimate intakes from the foods and beverages reported as consumed on the day prior to the NHANES visit. Breakfast was self-defined by participants. Total population-based means (95% CI) of nutrient intakes, MyPlate equivalents, and Healthy Eating Index 2015 scores from the day of intake were calculated across levels of glycemic control and skipping breakfast status.

Results

Across all groups, adults who reported breakfast consumption had a significantly better overall diet quality, while total intakes of whole grains and fiber were significantly lower in those who skipped breakfast. Intakes of added sugars were not significantly different between those who skipped versus consumed breakfast.

Conclusions

The absence of breakfast on the day of intake was related to differential intakes of several nutrients related to healthy eating and glycemic management, resulting in a poorer overall diet quality. Healthcare professionals could evaluate meal skipping patterns and its impact on overall nutrient intakes, and the distribution of food intake throughout the day, in people with diabetes, to help improve disease management.

Funding Sources

Abbott Nutrition.

Body Weight, BMI, Percent Fat, Lean Mass and Their Long-Term Associations with Mortality and Incident Mobility Limitation

Objectives

Adiposity is often approximated by body mass index (BMI), weight, and % fat from dual energy x-ray absorptiometry (DXA). We aimed to describe how different measures of adiposity and body composition are similarly or differentially related to mobility limitation and mortality.

Methods

Older community-dwelling men aged ≥65 yrs were followed for 10 years for mortality (N = 5849) and at six study contacts over 14 year for self-reported mobility limitations (any difficulty walking 2–3 blocks or with climbing 10 steps, N = 5841). Baseline measures of adiposity included weight, BMI, % fat by DXA. Appendicular lean mass (ALM, by DXA) was analyzed as ALM/ht2. Proportional hazards models estimated the risk of mortality and repeated measures generalized estimating equations estimated the likelihood of mobility limitation. Adiposity and ALM/ht2 measures were analyzed as quintiles and with splines.

Results

Over 10 years, 27.9% of men died; over 14 years, 48.0% of men reported at least one mobility limitation. We observed U-shaped relationships between weight, BMI, % fat and ALM/ht2 with mortality. There was a log-linear relationship between weight, BMI and % fat with incident mobility limitation, with higher values associated with greater likelihood of mobility limitation: for those with the lowest values of each of these metrics (quintile 1), the likelihood of mobility limitation was 1.6 to 3.5 times greater than those with the highest values for these metrics (quintile 5, P &lt; .001 for all). In contrast, there was a U-shaped relationship between ALM/ht2 and incident mobility limitation.

Conclusions

These observational data suggest that there is not a single weight, BMI or % fat value that can represent both the lowest risk of mortality and also the lowest likelihood for developing mobility limitation over time in older men.

Funding Sources

National Institute on Aging and Abbott Nutrition.

Exploring the Association between Vascular Dysfunction and Skeletal Muscle Mass, Strength and Function in Healthy Adults: A Systematic Review

Background: The prevalence of vascular dysfunction increases with advancing age, as does the loss of muscle mass, strength and function. This systematic review explores the association between vascular dysfunction and skeletal muscle health in healthy adults. Methods: EMBASE and MEDLINE were searched for cross-sectional and randomized controlled studies between January 2009 and April 2019, with 33 out of 1246 studies included based on predefined criteria. Assessments of muscular health included muscle mass, strength and function. Macrovascular function assessment included arterial stiffness (pulse wave velocity or augmentation index), carotid intima-media thickness, and flow-mediated dilation. Microvascular health assessment included capillary density or microvascular flow (contrast enhanced ultrasound). Results: All 33 studies demonstrated a significant association between vascular function and skeletal muscle health. Significant negative associations were reported between vascular dysfunction and -muscle strength (10 studies); -mass (9 studies); and -function (5 studies). Nine studies reported positive correlations between muscle mass and microvascular health. Conclusions: Multiple studies have revealed an association between vascular status and skeletal muscle health in healthy adults. This review points to the importance of screening for muscle health in adults with vascular dysfunction with a view to initiating early nutrition and exercise interventions to ameliorate functional decline over time.

Low Protein Intake Irrespective of Source is Associated with Higher Mortality Among Older Community-dwelling Men

OBJECTIVES

Our aim was to determine the association between protein intake (overall and by source) and all-cause and cause-specific mortality among older men.

DESIGN

Prospective cohort study.

SETTING

5790 ambulatory community-dwelling older men from multicenter Osteoporotic Fractures in Men (MrOS) study.

MEASUREMENTS

Total energy and protein intake, and protein intake by source (dairy, non-dairy animal, plant) were assessed using a 69-item food frequency questionnaire. We included up to 10-year follow-up with adjudicated cardiovascular, cancer and other mortality outcomes. We used time-to-event analysis with protein exposures, mortality outcome, and adjusted for possible confounders including age, center, education, race, smoking, alcohol use, physical activity, weight, total energy intake (TEI), and comorbidities. Hazard ratios were expressed per each unit=2.9% TEI decrement for all protein intake variables.

RESULTS

The mean (SD) baseline age of 5790 men was 73.6 (5.8) y. There were 1611 deaths and 211 drop-outs prior to 10 years, and 3868 men who were alive at the 10-year follow-up. The mean (SD) total protein intake was 64.7 (25.8) g/d, while the mean (SD) intake expressed as percent of total energy intake (%TEI) was 16.1 (2.9) %TEI. Lower protein intake was associated with an increased risk of death, with unadjusted HR=1.11 (95% CI: 1.06, 1.17) and adjusted HR=1.09 (95% CI: 1.04, 1.14) and the associations for protein intake by source were similar. The adjusted HR for cancer mortality was HR=1.13 (95% CI: 1.03, 1.25) while the association for CVD mortality was HR=1.08 (95% CI: 0.99, 1.18).

CONCLUSIONS

Low protein intake, irrespective of source, was associated with a modest increase in risk of all-cause and cause-specific mortality among older men. Special consideration should be given to level of protein intake among older adults.

Substituting whole grains for refined grains in a 6-wk randomized trial has a modest effect on gut microbiota and immune and inflammatory markers of healthy adults

Background: Observational studies suggest an inverse association between whole-grain (WG) consumption and inflammation. However, evidence from interventional studies is limited, and few studies have included measurements of cell-mediated immunity.Objective: We assessed the effects of diets rich in WGs compared with refined grains (RGs) on immune and inflammatory responses, gut microbiota, and microbial products in healthy adults while maintaining subject body weights.Design: After a 2-wk provided-food run-in period of consuming a Western-style diet, 49 men and 32 postmenopausal women [age range: 40-65 y, body mass index (in kg/m2) <35] were assigned to consume 1 of 2 provided-food weight-maintenance diets for 6 wk.Results: Compared with the RG group, the WG group had increased plasma total alkyresorcinols (a measure of WG intake) (P < 0.0001), stool weight (P < 0.0001), stool frequency (P = 0.02), and short-chain fatty acid (SCFA) producer Lachnospira [false-discovery rate (FDR)-corrected P = 0.25] but decreased pro-inflammatory Enterobacteriaceae (FDR-corrected P = 0.25). Changes in stool acetate (P = 0.02) and total SCFAs (P = 0.05) were higher in the WG group than in the RG group. A positive association was shown between Lachnospira and acetate (FDR-corrected P = 0.002) or butyrate (FDR-corrected P = 0.005). We also showed that there was a higher percentage of terminal effector memory T cells (P = 0.03) and LPS-stimulated ex vivo production of tumor necrosis factor-α (P = 0.04) in the WG group than in the RG group, which were positively associated with plasma alkylresorcinol concentrations.Conclusion: The short-term consumption of WGs in a weight-maintenance diet increases stool weight and frequency and has modest positive effects on gut microbiota, SCFAs, effector memory T cells, and the acute innate immune response and no effect on other markers of cell-mediated immunity or systemic and gut inflammation. This trial was registered at clinicaltrials.gov as NCT01902394.

Incidence and correlates of tuberculosis IGRA conversion among HIV-infected postpartum women

SETTING

Prevention of maternal-to-child transmission program at a tertiary care hospital in Nairobi, Kenya. The risk of acquiring Mycobacterium tuberculosis infection among peripartum human immunodeficiency virus (HIV) infected women is poorly defined.

OBJECTIVE

To determine the incidence of and co-factors for interferon-gamma release assay (IGRA) conversion among postpartum HIV-infected women using T-SPOT.TB.

DESIGN

We used data and cryopreserved peripheral blood mononuclear cells from a historical cohort of HIV-infected women enrolled at 32 weeks' gestation and followed for 1 year postpartum between 1999 and 2005.

RESULTS

Of 89 women initially IGRA-negative during pregnancy, 11 (12.4%) became positive, 53 (59.5%) remained negative and 25 (28.1%) were indeterminate at 1 year postpartum. Mean interferon-gamma (IFN-γ) response among converters increased from ~1 to >50 spot-forming cells/well (P = 0.015). IGRA conversion was significantly associated with partner HIV infection, flush toilets, maternal illness and cough during follow-up, but not maternal CD4 count or HIV viral load.

CONCLUSION

The high rates of IGRA conversion seen among HIV-infected postpartum women in our study are similar to those of other groups at high risk for M. tuberculosis infection. This has important implications for M. tuberculosis infection screening strategies and provision of preventive therapy for the health of women and their infants.

Prognostic Performance of Current Stage III Oral Cancer Patients After Curative Intent Resection: Evidence to Support a Revision of the American Joint Committee on Cancer Staging System

BACKGROUND

The American Joint Committee on Cancer (AJCC) stage III classification of oral cavity squamous cell carcinoma (OCSCC) represents a heterogeneous group of patients with early local disease with regional metastases (T1N1 and T2N1) and advanced local disease with or without regional metastasis (T3N0 and T3N1).

OBJECTIVE

The aim of this study was to evaluate prognostic heterogeneity in the stage III category.

METHODS AND PATIENTS

An international retrospective multicenter study of 1815 patients who were treated for OCSCC from 2003 to 2011.

RESULTS

Kaplan-Meier survival analysis and multivariate models of stage III patients revealed better overall survival (OS; HR 2.12, 95 % CI 1.03-4.15; p = 0.01) and disease-specific survival (DSS; HR 1.7, 95 % CI 1.16-4.12; p = 0.04) rates for patients with T1-2N1/T3N0 disease than for patients with T3N1 disease. The outcomes of patients with T3N1 and stage IVa disease were similar (p = 0.89 and p = 0.78 for OS and DSS, respectively). Modifying stage classification by transferring the T3N1 category to the stage VIa group resulted in a better prognostic performance [Harrell's concordance index, C index 0.76; Akaike's Information Criterion (AIC) 4131.6] compared with the AJCC 7th edition staging system (C index 0.65; AIC 4144.9) for OS. When DSS was assessed, the suggested staging system remained the best performing model (C index 0.71; AIC 1061.3) compared with the current AJCC 7th edition staging (C index 0.64; AIC 1066.2).

CONCLUSIONS

The prognosis of T3N1 and stage IVa disease are similar in OCSCC, suggesting that these categories could be combined in future revisions of the nodal staging system to enhance prognostic accuracy.

Whole-grain wheat consumption reduces inflammation in a randomized controlled trial on overweight and obese subjects with unhealthy dietary and lifestyle behaviors: role of polyphenols bound to cereal dietary fiber

BACKGROUND

Epidemiology associates whole-grain (WG) consumption with several health benefits. Mounting evidence suggests that WG wheat polyphenols play a role in mechanisms underlying health benefits.

OBJECTIVE

The objective was to assess circulating concentration, excretion, and the physiologic role of WG wheat polyphenols in subjects with suboptimal dietary and lifestyle behaviors.

DESIGN

A placebo-controlled, parallel-group randomized trial with 80 healthy overweight/obese subjects with low intake of fruit and vegetables and sedentary lifestyle was performed. Participants replaced precise portions of refined wheat (RW) with a fixed amount of selected WG wheat or RW products for 8 wk. At baseline and every 4 wk, blood, urine, feces, and anthropometric and body composition measures were collected. Profiles of phenolic acids in biological samples, plasma markers of metabolic disease and inflammation, and fecal microbiota composition were assessed.

RESULTS

WG consumption for 4-8 wk determined a 4-fold increase in serum dihydroferulic acid (DHFA) and a 2-fold increase in fecal ferulic acid (FA) compared with RW consumption (no changes). Similarly, urinary FA at 8 wk doubled the baseline concentration only in WG subjects. Concomitant reduction in plasma tumor necrosis factor-α (TNF-α) after 8 wk and increased interleukin (IL)-10 only after 4 wk with WG compared with RW (P = 0.04) were observed. No significant change in plasma metabolic disease markers over the study period was observed, but a trend toward lower plasma plasminogen activator inhibitor 1 with higher excretion of FA and DHFA in the WG group was found. Fecal FA was associated with baseline low Bifidobacteriales and Bacteroidetes abundances, whereas after WG consumption, it correlated with increased Bacteroidetes and Firmicutes but reduced Clostridium. TNF-α reduction correlated with increased Bacteroides and Lactobacillus. No effect of dietary interventions on anthropometric measurements and body composition was found.

CONCLUSIONS

WG wheat consumption significantly increased excreted FA and circulating DHFA. Bacterial communities influenced fecal FA and were modified by WG wheat consumption. This trial was registered at clinicaltrials.gov as NCT01293175.

Total dietary fiber intakes in the US population are related to whole grain consumption: results from the National Health and Nutrition Examination Survey 2009 to 2010

Whole grain (WG) foods have been shown to reduce chronic disease risk and overweight. Total dietary fiber is associated with WG and its health benefits. The purpose was to determine whether associations exist between WG intake (no-WG intake, 0 ounce equivalent [oz eq]; low, >0-<3 oz eq; high, ≥3 oz eq) and total dietary fiber intake among Americans 2 years and older. One-day food intake data from the US National Health and Nutrition Examination Survey 2009 to 2010 (n = 9042) showed that only 2.9% and 7.7% of children/adolescents (2-18 years) and adults (≥19 years) consumed at least 3 WG oz eq/d, respectively. For children/adolescents and adults, individuals in the high WG intake group were 59 and 76 times more likely to fall in the third fiber tertile, respectively, compared with those with no-WG intake. Total dietary fiber intake from food sources varied by WG intake group for children/adolescents and adults with more total dietary fiber consumed from ready-to-eat (RTE) and hot cereals and yeast breads/rolls in the high WG intake group compared with the no-WG intake group. Major WG sources for children/adolescents and adults included yeast bread/rolls (24% and 27%, respectively), RTE cereals (25% and 20%, respectively), and oatmeal (12% and 21%, respectively). Among those with the highest WG intake, WG RTE cereal with no added bran was the greatest contributor to total dietary fiber compared with other RTE cereal types. Whole grain foods make a substantial contribution to total dietary fiber intake and should be promoted to meet recommendations.

The effect of coencapsulation of bovine insulin with cyclodextrins in ethylcellulose microcapsules

Polymeric microcapsules have been widely investigated for protein delivery. Common problems include: low stability, low encapsulation efficiency, lack of uniformity, and burst release. Cyclodextrins (CDs) are known to enhance stability and solubility of proteins in solution. This research examines the effect of alpha-, beta-, and gamma-CDs on: (1) stability, (2) encapsulation, and (3) release of insulin from ethylcellulose microcapsules. All CDs improved thermal stability of insulin by lowering the enthalpy of unfolding by 16-52%. alpha- and gamma-CDs also increased the encapsulation efficiency of insulin and improved uniformity of the microcapsule formulations. Two mathematical models were proposed to account for insulin release and consisted of multiple zero order and first order input processes, and a single first order output process. All CDs decreased the initial burst release of insulin by up to 30%. This research demonstrates the potential for CDs to improve stability, uniformity, and encapsulation of proteins in microcapsule formulations.

Comparison of white light and narrow band high definition images in predicting colon polyp histology, using standard colonoscopes without optical magnification

BACKGROUND AND STUDY AIMS

Narrow band imaging (NBI) with optical magnification is useful in predicting colon polyp histology. As magnifying endoscopes are not routinely available, we investigated the use of NBI and high definition white light imaging in determining polyp histology, using images obtained with colonoscopes without optical magnification.

PATIENTS AND METHODS

Images (white light and NBI) of colon polyps less than 10 mm in diameter were collected prospectively from patients undergoing screening colonoscopy and digitally stored. Two endoscopists later reviewed all images and predicted polyp histology as neoplastic or non-neoplastic using a modified Kudo classification. Comparison was made with histopathology.

RESULTS

Separate white light and NBI images of 80 polyps (49 neoplastic, 31 non-neoplastic) from 63 patients were recorded. Mean polyp size was 5.1 +/- 2.1 mm (5.4 +/- 2.2 neoplastic; 4.4 +/- 1.8 non-neoplastic; P = 0.02). In a pooled analysis, NBI correctly predicted neoplastic histology in 93 of 98 images (sensitivity 95 %, positive predictive value [PPV] 94 %) whereas white light did so in 58 of 98 images (sensitivity 59 %, PPV 79 %). NBI correctly predicted non-neoplastic histology in 56 of 62 images (specificity 90 %, negative predictive value [NPV] 92 %) whereas white light did so in 47 of 62 images (specificity 76 %, NPV 54 %).

CONCLUSIONS

NBI without optical magnification was more accurate in predicting colon polyp histology compared with white light imaging. Image quality and confidence in histology were significantly higher in the NBI group. NBI without optical magnification may be useful in predicting colon polyp histology.

The impact of endoscopic ultrasonography with fine needle aspiration (EUS-FNA) on esophageal cancer staging: a survey of thoracic surgeons and gastroenterologists

Accurate staging of esophageal cancer is critical to achieving optimal treatment outcomes. End-oscopic ultrasound with fine needle aspiration (EUS-FNA) has emerged as a valuable tool for locoregional staging. However, it is unclear how different physician specialties perceive the benefit of EUS-FNA for esophageal cancer staging, and thus utilize this modality in clinical practice. A survey regarding utilization of EUS-FNA in esophageal cancer was distributed to 211 thoracic surgeons and 251 EUS-capable gastroenterologists. Seventy-six thoracic surgeons (36%) and 78 gastroenterologists (31%) responded to the survey. Most surgeons (75%) use EUS to stage potentially resectable esophageal cancer 75% of the time. Surgeons using EUS less often are less likely to have access to high-quality EUS services than their peers. Fewer surgeons believe EUS is the most accurate test for T and N-staging (84% and 71%, respectively) as compared with gastroenterologists (97% and 96%, P < 0.01 for both). Most endosonographers (68%) decide whether to dilate a malignant esophageal stricture to complete the staging exam on a case-by-case basis. Surgeons disagree as to whether involvement of celiac lymph nodes should preclude esophagectomy in distal esophageal cancer. While most thoracic surgeons have embraced EUS-FNA as the most accurate locoregional staging modality in esophageal cancer, this attitude is not fully reflected in utilization patterns due to a lack of quality EUS services in some centers. Controversial areas that warrant further study include dilation of malignant strictures to facilitate EUS staging, and the implication of involved celiac lymph nodes on management.

Ornithine transcarbamylase deficiency unmasked because of gastrointestinal bleeding

Ornithine transcarbamylase (OTC) is a mitochondrial-matrix enzyme that catalyzes conversion of ornithine and carbamyl phosphate to citrulline, the second step in the urea cycle. The urea cycle is the most important pathway to detoxification of ammonia in human beings. Ornithine transcarbamylase deficiency (OTCD) is the most common urea cycle disorder, inherited as an X-linked disorder that can cause fatal hyperammonemia in male newborns. Women with OTCD have a variable expression of their disease, the variability being determined by lyonization (random inactivation) of the X chromosome. We report a case of a 28-year-old woman who presented with hyperammonemic encephalopathy that was precipitated by a gastrointestinal bleed unmasking OTCD.

Gallstones, from gallbladder to gut. Management options for diverse complications

Gallstones may be incidental and asymptomatic or painful and accompanied by life-threatening obstruction or infection. A thorough knowledge of potential complications is therefore critical, especially because some asymptomatic stones require prompt treatment. In this article, Drs Agrawal and Jonnalagadda provide valuable instructions for recognizing and treating the various manifestations of gallstone disease.

Lowering dietary saturated fat and total fat reduces the oxidative susceptibility of LDL in healthy men and women

The present study examined the effects of reducing dietary total fat and saturated fat (SFA) on LDL oxidative susceptibility in 27 healthy men and women (age 24-65 y). Each subject consumed each of three diets for 8 wk: an average American diet (AAD, 34% energy from fat, 15% from SFA), a Step-1 diet (29% fat, 9% SFA) and a very low SFA diet (Low-Sat, 25% fat, 6% SFA). In vitro LDL oxidation was assessed by copper-mediated oxidation, as measured by the kinetics of conjugated diene formation and lipid peroxide formation. Compared with the AAD, plasma LDL-cholesterol (LDL-C) and HDL cholesterol levels were 8% lower (P: = 0.16 and P: = 0.11, respectively), in subjects when they consumed the Step-1 diet and 11% (P: < 0.03) and 14% (P: < 0.057) lower, respectively, when they consumed the Low-Sat diet. Conjugated diene production and oxidation rate were 7% (P: < 0. 05) and 9% (P: < 0.05) lower, respectively. The reduction of lipid peroxide formation was 9% (P: < 0.05) in subjects when they consumed the Low-Sat diet vs. the AAD. In addition, lipid peroxide and conjugated diene formation were positively correlated with plasma total and LDL-C and apolipoprotein B (apo B) levels (r = 0.5-0.6, P: < 0.001), suggesting that quantity of LDL is an important determinant of oxidative modification. Furthermore, at the same level of apo B or LDL-C, LDL from subjects when they consumed either Step-1 or Low-Sat diets was less susceptible (P: < 0.05) to oxidation than those when they consumed the AAD, suggesting that qualitative changes also affect LDL oxidative susceptibility. Therefore, the benefits of lowering dietary SFA may extend beyond decreasing LDL-C levels and include favorable qualitative changes in LDL that further decrease risk of coronary heart disease.

Purification and characterization of flavokinase from Neurospora crassa

The ATP-dependent phosphorylation of riboflavin to FMN by flavokinase is the key step in flavin biosynthesis. Flavokinase has been purified from a fungal source for the first time. The enzyme purified from a cell wall lacking mutant of Neurospora crassa, slime, is a monomer of M(r) 35.5 kDa with maximal activity at alkaline pH and high temperature (55 degrees C). The K(m) for both substrates is the lowest reported for flavokinase from any source so far (120 nM for riboflavin and 210 nM for MgATP2-). The enzyme exhibits preference for Mg2+ over Zn2+ as the essential activator and is also significantly activated by several cations. Activation by orthophosphate may be physiologically relevant for the intracellular regulation of flavokinase.

Effects of the National Cholesterol Education Program's Step I and Step II dietary intervention programs on cardiovascular disease risk factors: a meta-analysis

BACKGROUND

Plasma lipid and lipoprotein responses have been variable in dietary intervention studies.

OBJECTIVE

The objective of this study was to evaluate the effects of the National Cholesterol Education Program's Step I and Step II dietary interventions on major cardiovascular disease risk factors using meta-analysis.

DESIGN

MEDLINE was used to select 37 dietary intervention studies in free-living subjects published from 1981 to 1997.

RESULTS

Step I and Step II dietary interventions significantly decreased plasma lipids and lipoproteins. Plasma total cholesterol (TC), LDL cholesterol, triacylglycerol, and TC:HDL cholesterol decreased by 0.63 mmol/L (10%), 0.49 mmol/L (12%), 0.17 mmol/L (8%), and 0.50 (10%), respectively, in Step I intervention studies, and by 0.81 mmol/L (13%), 0.65 mmol/L (16%), 0.19 mmol/L (8%), and 0.34 (7%), respectively, in Step II intervention studies (P < 0.01 for all). HDL cholesterol decreased by 7% (P = 0.05) in response to Step II but not to Step I dietary interventions. Positive correlations between changes in dietary total and saturated fatty acids and changes in TC and LDL and HDL cholesterol were observed (r = 0.59, 0.61, and 0.46, respectively; P < 0.001). Multiple regression analyses showed that for every 1% decrease in energy consumed as dietary saturated fatty acid, TC decreased by 0.056 mmol/L and LDL cholesterol by 0.05 mmol/L. Moreover, for every 1-kg decrease in body weight, triacylglycerol decreased by 0.011 mmol/L and HDL cholesterol increased by 0.011 mmol/L. Exercise resulted in greater decreases in TC, LDL cholesterol, and triacylglycerol and prevented the decrease in HDL cholesterol associated with low-fat diets.

CONCLUSION

Step I and Step II dietary interventions have multiple beneficial effects on important cardiovascular disease risk factors.

Orthophosphate is a non-essential activator of Vigna radiata flavokinase

The ATP-dependent phosphorylation of riboflavin to FMN by flavokinase from Vigna radiata was activated by orthophosphate (Pi) in a concentration dependent manner. Pi affected both the K(m) and Vmax, indicating that it is a non-essential, mixed type activator. The extent of activation by Pi was dependent on the cation (Mg2+ or Zn2+). Activation by other anions could be correlated to similarity to Pi in molecular size and structure. These observations suggest the presence of a binding site(s) for a phosphate-like anion on flavokinase.

Activation of enzymatic catalysis

Modulation of enzyme activity by inhibition and activation plays an important physiological role in regulation of cellular metabolism. Compared to the wealth of information available regarding inhibition of metabolic pathways, little is known about activation. Limited proteolysis of zymogens exemplifies irreversible activation. Reversible activation may involve post-translational modifications or dissociable binding of small molecules. Sometimes, chemical modification may also activate enzymes. The influence of small molecules on the reversible binding and activation of enzymes is summarized.

Combinatorial synthesis and screening of a chemical library of 1,4-dihydropyridine calcium channel blockers

Solid-phase synthesis of a 300-member pharmacophore library of 1,4-dihydropyridines from keto ester, diketone and aldehyde building blocks on a cleavable amine polymeric support is described. Screening and serial deconvolution of the combinatorial library has resulted in identification of known and new potent calcium channel blockers.

Perils of partitioning: A case study of flavins and flavokinase

Partitioning is a common procedure for the separation of two solutes from a solution based on their differential solubility in an immiscible solvent. This has been widely used to quantitate riboflavin, flavin mononucleotide (FMN), and flavin adenine dinucleotide in aqueous samples by extraction with water-saturated benzyl alcohol. Here we report that the partitioning of riboflavin and FMN is affected by the presence of each other in a concentration-dependent manner, thus rendering this procedure unsuitable for quantitation. Direct quantitation of FMN formed in assays for flavokinase from Vigna radiata shows that kinetic analyses using a partition-based assay lead to erroneous conclusions.

Candida albicans osteomyelitis in a liver transplant recipient: a case report and review of the literature

A 51-year-old man developed fever and back pain 2 months after orthotopic liver transplantation for end-stage liver disease secondary to chronic hepatitis C infection. CT scan demonstrated destructive lesions in T12 suggestive of osteomyelitis. Aspiration biopsy of the vertebra revealed granulomatous inflammation and yeast forms; culture yielded Candida albicans. The patient improved with intravenous amphotericin B and 5-fluorocytosine and did not require surgical intervention. Candida osteomyelitis is a rare condition and to our knowledge it has not been reported before in liver transplant recipients. Awareness of this potential complication may shorten the delay in making the definitive diagnosis, which in turn may increase the likelihood of a response without sequela.

Modulation of cholecystokinin activity by albumin

We found that a variety of cholecystokinin (CCK) receptor ligands bind to bovine serum albumin (BSA). This binding was rapid, fully reversible, temperature independent, of low affinity, and specific for BSA; it depended on the concentration of BSA, the chemical structure of the ligand, and the chemical composition of the incubation medium. BSA also decreased the binding of 125I-labeled CCK octapeptide (125I-CCK-8) to CCK receptors on pancreatic acini and membranes but increased the potency with which CCK-8 inhibited binding of 125I-CCK-8. These counterintuitive findings appeared to result from BSA altering the affinities of CCK-8 for different affinity states of the pancreatic CCK receptor. An alternate hypothesis is that BSA increased the efficacy of CCK-8 such that it bound to receptors and also caused biochemical changes in other receptors that reduced their ability to bind 125I-CCK-8. BSA enhanced the ability of CCK-8 to stimulate amylase secretion from pancreatic acini and to cause contraction of dispersed gastric smooth muscle cells. Thus, CCK can bind to BSA, and the BSA-CCK complex has substantially different activities from the free, uncomplexed hormone.

Multiple (alpha-NH-ubiquitin)protein endoproteases in cells

Ubiquitin is encoded as a variable, spacerless repeat of the gene terminating with an additional amino acid or as a gene coding for a single ubiquitin with a carboxyl-terminal extension of 52 to 80 amino acids. We report the identification and partial purification of enzymes that specifically hydrolyze the peptide bond between ubiquitin-ubiquitin conjugate (Ub-Ubase) or ubiquitin fusion proteins (Ub-Xase). The Ub-Ubase was separated from the Ub-Xase by dye-ligand-Sepharose chromatography. The Ub-Xase was purified further by affinity chromatography on ubiquitin-Sepharose. The fidelity of the endoprotease reaction was assessed by measuring the ability of the released ubiquitin to be activated by ubiquitin-activating enzyme (E1) which requires intact ubiquitin and by sequence analysis of the released carboxyl extension protein with 52 amino acids after endoproteolysis of human ubiquitin with 52-amino acid carboxyl extension. The failure of both Ub-Ubase and Ub-Xase to cleave a mutant ubiquitin-Gly-76----Ala-metallothionein showed that the endoproteases distinguish Gly-X from an Ala-X peptide bonds.