Utilization of Biopolymer-Based Lutein Emulsion as an Effective Delivery System to Improve Lutein Bioavailability in Neonatal Rats

Newborns' eyes and brains are prone to oxidative stress. Lutein has antioxidant properties and is the main component of macular pigment essential for protecting the retina, but has low bioavailability, thereby limiting its potential as a nutritional supplement. Oil-in-water emulsions have been used as lutein delivery systems. In particular, octenylsuccinated (OS) starch is a biopolymer-derived emulsifier safe to use in infant foods, while exhibiting superior emulsifying capacity. This study determined the effects of an OS starch-stabilized lutein emulsion on lutein bioavailability in Sprague-Dawley neonatal rats. In an acute study, 10-day-old pups received a single oral dose of free lutein or lutein emulsion, with subsequent blood sampling over 24 h to analyze pharmacokinetics. The lutein emulsion group had a 2.12- and 1.91-fold higher maximum serum lutein concentration and area under the curve, respectively, compared to the free lutein group. In two daily dosing studies, oral lutein was given from postnatal day 5 to 18. Blood and tissue lutein concentrations were measured. The results indicated that the daily intake of lutein emulsion led to a higher lutein concentration in circulation and key tissues compared to free lutein. The OS starch-stabilized emulsion could be an effective and safe lutein delivery system for newborns.

Feeding Stressors and Resources Used by Caregivers of Children With Down Syndrome: A Qualitative Analysis

BACKGROUND

Challenging eating behaviors or feeding difficulties, commonly displayed in children with Down syndrome (DS), may amplify perceived stress in caregivers. If caregivers lack resources on how to accommodate the needs of the child with DS, they may find feeding the child stressful and resort to negative coping strategies.

OBJECTIVE

The aim of this study was to understand the feeding stressors, resources, and coping strategies used by caregivers of children with DS.

DESIGN

A qualitative analysis of interview transcripts was undertaken, framed around the Transactional Model of Stress and Coping.

PARTICIPANTS/SETTING

Between September to November 2021, 15 caregivers of children (aged 2 through 6 years) with DS, were recruited from 5 states located in the Southeast, Southwest, and West regions of the United States.

ANALYSIS

Interviews were audio-recorded, transcribed verbatim, and analyzed using deductive thematic analysis and content analysis approaches.

RESULTS

Thirteen caregivers reported increased stress around feeding the child with DS. Stressors identified included concern about adequacy of intake and challenges associated with feeding difficulties. Stress related to feeding was higher among caregivers whose child was learning a new feeding skill or in a transitional phase of feeding. Caregivers used both professional and interpersonal resources in addition to problem- and emotion-based coping strategies.

CONCLUSIONS

Caregivers identified feeding as a stressful event with higher stress reported during transitional phases of feeding. Caregivers reported that speech, occupational, and physical therapists were beneficial resources to provide support for optimizing nutrition and skill development. These findings suggest that caregiver access to therapists and registered dietitian nutritionists is warranted.

A Qualitative Analysis of Experiences With Food-Related Activities Among People Living With Parkinson Disease and Their Care-Partners

Objectives: The purpose of this qualitative study was to explore factors associated with the ability of people with PD to perform food-related activities (FRAs). Methods: Eleven dyads, older adults with Parkinson disease (PD) and their care-partners (n = 22), completed virtual semi-structured interviews guided by the Social Cognitive Theory (SCT) that were independently analyzed by two coders via directed content analysis. Results: The following themes were identified-(1) Personal: perception of a healthy diet, perception of how nutrition influences PD, confidence in following a healthy diet, and barriers to performing FRA; (2) Environmental: previous sources of nutrition information and willingness to changing their diet with a registered dietitian; and (3) Behavioral: modifications to FRA due to food-medication interactions, and skills necessary to maintain a healthy diet. Discussion: Findings from this study highlight the need for nutrition intervention research to inform evidence-based guidelines in order to provide tailored education for people with PD and care-partners.

A Mixed Methods Exploration of the Impact of the COVID-19 Pandemic on Food-Related Activities and Diet Quality in People with Parkinson Disease

OBJECTIVE

The purpose of this mixed methods study was to explore the impact of COVID-19 on the ability of people with Parkinson disease (PwPs) and their care-partners to perform food-related activities (FRA) and PwPs' overall diet quality.

METHODS

Using a convergent parallel mixed methods design, PwPs and their care-partners completed virtual dyadic semi-structured interviews about their FRA during the COVID-19 pandemic. PwPs completed Food Frequency Questionnaires (FFQ) to quantify their dietary intake in the previous 12 months. Qualitative data were analyzed by two coders using thematic analysis, and quantitative data from FFQs were descriptively analyzed to calculate diet quality scores.

RESULTS

Eleven dyadic interviews revealed the following key themes: cooking more at home; changes with grocery shopping; less meals with non-household members. These changes were described to increase the care-partners' responsibilities and overall burden. Diet scores among PwPs were 73.0 ± 6.3 for the Healthy Eating Index 2015 (scale of 0-100), 29.2 ± 6.6 for the Mediterranean diet (scale of 0-55), and 10.4 ± 1.8 for the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet (scale 0-15).

CONCLUSIONS

Diet scores revealed that PwPs consumed a high-quality diet during the pandemic. Findings from this study highlight the need for tailored nutrition education to support PwPs' care-partners.

An Update to Scientific Decision Making: The Academy of Nutrition and Dietetics' Scientific Integrity Principles

In 2015, the Council on Research published their vision for scientific decision making which provided nutrition and dietetics practitioners and practitioners-in-training key information on the Academy's newly developed scientific integrity principles (SIP). Given that it has been 7 years since the original publication, it was felt the original 6 principles should be revisited and updated. From the subcommittee on Scientific Integrity Principles under the Council on Research, the 2015 principles were evaluated and updated with new literature and best practices for maintaining SIP. After this review process, four new/updated principles were approved by the Council on Research. These include 1) the ethical conduct of research and protection of human subjects, 2) funder's influence on the research question/methodology/education content and conflicts of interest, 3) review of research-related materials, and 4) maintain and promote a culture of scientific integrity. Moreover, it became clear that newer topics including diversity, equity, and inclusion should be woven throughout the principles. This article presents the newly updated principles and resources related to SIP. We envision that this document can be used by the Academy to educate members and serve as a guide to incorporate these principles into all research practices and at all levels of dietetics practice.

Eat Like a Chef: A Mindful Eating Intervention for Health Care Providers

OBJECTIVE

To compare changes in mindful eating habits between students receiving a mindful eating intervention (MEI) vs those who were engaged in usual course work.

METHODS

From 2017 to 2019, 109 nutrition and medical students completed a quasi-experimental study, including usual course work either with or without the addition of a 5-week MEI. The Mindful Eating Questionnaire (MEQ) was completed before and after the MEI. Repeated measures MANOVA was used to detect differences in changes in the overall MEQ score and its 5 subscales between groups.

RESULTS

Within the MEI group (n = 64), overall MEQ, disinhibition, and eating with awareness scores increased significantly (P < .001, P < .001, and P = .004, respectively). No significant changes were noted within the comparison group (n = 45). Significant between-group differences were noted for the changes in the overall MEQ (P = .03) and disinhibition scores (P = .01).

CONCLUSIONS AND IMPLICATIONS

MEI participation may improve students' overall mindful eating scores. Future research could assess a larger cohort of participants, including health care professionals from other disciplines, assess additional mindfulness measures, and follow students for a longer period to determine the long-term effects on participants' mindful eating.

Nutrition Provider Isolation Is Related to Increased Preference for Enteral Nutrition-Support in Patients With Advanced Dementia

BACKGROUND

Current guidelines advise against using enteral nutrition (EN) support for patients with advanced dementia (AD) because of negative outcomes. However, research suggests that some registered dietitian nutritionists (RDNs) in acute-care settings still recommend EN for this patient population. The purpose of this study was to identify workplace characteristics that influence the EN recommendations of acute-care RDNs who care for patients with AD.

METHODS

A random sample of 5000 RDNs in the United States were invited to participate in a web-based survey in which RDNs self-reported the likelihood that they would recommend EN for a patient with AD. Inclusion criteria specified that participants were at least 18 years of age, were an RDN in the United States, and currently provide nutrition care to older adults with dementia. χ² tests compared RDN recommendations by workplace characteristics. Logistic regression was used to determine factors associated with recommending EN for patients with AD.

RESULTS

Respondents included 204 acute-care RDNs. RDNs in rural or suburban locations were 2.4 times more likely to recommend EN compared with those in urban facilities (95% CI, 1.1-5.1). RDNs who were the only nutrition provider at their facility were 3.3 times more likely to recommend EN than those in facilities with multiple RDNs (95% CI, 1.4-7.9).

CONCLUSION

Acute-care RDNs who are isolated either in rural facilities or because they lack other RDN colleagues at their facility may benefit from targeted interventions to increase knowledge and promote adherence to evidence-based guidelines.

Practitioner Knowledge, Personal Values, and Work Setting Influence Registered Dietitians' Feeding Tube Recommendations for Patients With Advanced Dementia

BACKGROUND

Current guidelines discourage tube-feeding older adults with advanced dementia (AD), as this practice does not improve nutrition status or survival and decreases quality of life in these patients. Because registered dietitians (RDs) often provide feeding recommendations for patients with AD, this study aimed to identify factors that influenced RDs' feeding tube recommendations for older adults with AD.

METHODS

A random sample of RDs who work with older adults in the United States completed a validated, electronic survey. Logistic regression analysis was used to identify factors related to the likelihood of RDs recommending a feeding tube for patients with AD. Independent variables included participant demographics and the 6 subscales of the Attitudes Toward Tube-Feeding in Advanced Dementia Questionnaire, which measured individual and environmental influences on RDs' recommendations.

RESULTS

Among the 662 RDs who responded, 72.2% were unlikely to recommend a feeding tube in patients with AD, and 15.4% were likely to do so (with the remaining being "neutral"). Factors associated with avoiding recommending a feeding tube include significantly higher total knowledge [odds ratio (OR) = 1.47, 95% CI (1.30, 1.66)] and personal values scores [OR = 7.51, 95% CI (3.96, 14.24)] and employment in long-term care settings [OR 3.29, 95% CI (1.38, 7.80)].

CONCLUSION

In this survey, most RDs were likely to make recommendations that are consistent with current guidelines for tube feeding patients with AD. RDs who work outside the long-term care setting may benefit from additional training. Future research is needed to understand how personal values may influence recommendations.

The Attitudes Toward Tube-Feeding in Advanced Dementia (ATT-FAD) Questionnaire: A Valid and Reliable Tool

Registered Dietitians (RDs) should participate in interdisciplinary feeding discussions for patients with advanced dementia, but research on how RDs make such feeding recommendations is scarce. This study developed and validated a theory-based questionnaire to assess the knowledge, beliefs, and attitudes of RDs regarding feeding tube use among older adults with advanced dementia. The instrument was drafted based on the Social Ecological Model, and face and content validity were established through an expert panel review. Pilot testing with 70 RDs provided an initial measure of internal consistency reliability and reduced the number of items in the survey. Efficacy testing with 662 RDs allowed for a second analysis of internal consistency reliability and eliminated additional items. Construct validity was then established using validation by extreme groups and exploratory factor analysis, yielding six subscales, each with adequate internal consistency and test-retest correlation coefficients: (I) Total Knowledge, (II) Knowledge Self-Efficacy, (III) Religion/Spirituality/Culture, (IV) Personal Values, (V) Perceived Organization and Training, and (VI) Perceived Policy. The survey, based on the Social Ecological Model, was deemed a valid and reliable tool to assess RDs' knowledge and attitudes regarding feeding tube use among older adults with advanced dementia.

Enteral Nutrition via Nasogastric Tube for Refeeding Patients With Anorexia Nervosa: A Systematic Review

Weight restoration is an important first step in treating patients with anorexia nervosa (AN), because it is essential for medical stabilization and reversal of long-term complications. Tube feeding may help facilitate weight restoration, but its role in treatment remains unclear. This study aimed to review the literature describing the efficacy, safety, tolerance, and long-term effects of nasogastric (NG) refeeding for patients with AN. Four electronic databases were systematically searched through May 2018. Boolean search terms included "anorexia nervosa," "refeeding," and "nasogastric tube feeding." Ten studies were eligible for inclusion: 8 retrospective chart reviews, 1 prospective cohort, and 1 randomized controlled trial. Nine of the studies were performed in-hospital. In 8 studies, NG nutrition resulted in an average rate of weight gain exceeding 1 kg/wk. In 4 of 5 studies including an oral-only control group, mean weekly weight gain and caloric intake were significantly higher in tube-fed patients. Six studies provided prophylactic phosphate supplementation, all with <1% occurrence rate of refeeding hypophosphatemia. Seven studies reported on other physiological disturbances, 6 evaluated medical and gastrointestinal side effects, 3 considered psychological outcomes, and 4 assessed patients postdischarge. Results indicated that NG feeding was not associated with an increased risk for adverse outcomes. Overall, in these studies, NG nutrition was considered safe and well tolerated, and effectively increased caloric intake and rate of weight gain in patients with AN. However, results are limited by weaknesses in study designs, and more rigorous methods are needed for development of evidence-based, standardized refeeding protocols.

Short communication: Relationship between methods for measurement of serum electrolytes and the relationship between ionized and total calcium and neutrophil oxidative burst activity in early postpartum dairy cows

The objectives of this study were to (1) compare a test for serum measurement of total Ca (tCa), Mg, and P (VetTest Chemistry Analyzer, IDEXX Laboratories Inc., Westbrook, ME) to reference methods (spectrophotometric assays on a Beckman Coulter 640e automated clinical chemistry analyzer; Beckman Coulter, Brea, CA), (2) determine the relationship between ionized Ca (iCa) and reference method tCa in the immediate postpartum period, and (3) assess the relative value of these blood Ca indices as predictors of neutrophil oxidative burst activity. Samples were collected from multiparous Holstein cows (n = 33) over the first 5 d in milk. A total of 183 samples for objective 1 and 181 samples for objective 2 were available. Neutrophil oxidative burst activity was assessed once between 2 and 5 d in milk (n = 29). Linear regression demonstrated strong relationships between serum tCa, Mg, and P concentrations measured by the VetTest compared with the reference method. Bland Altman analysis indicated that the VetTest values were higher than the reference method by 0.22 mmol/L for tCa, 0.12 mmol/L for Mg, and 0.16 mmol/L for P. Compared with hypocalcemia categorized at ≤2.0 or ≤2.125 mmol/L with the reference method tCa, thresholds for the VetTest measured tCa of ≤2.23 mmol/L (sensitivity = 87%, specificity = 89%) or ≤2.30 mmol/L (sensitivity = 86%, specificity = 96%) could be used. The relationship between whole-blood iCa and reference method serum tCa differed by sampling time point after calving. Compared with identification of hypocalcemia with serum tCa measurements from the reference method (thresholds of ≤2.0 and 2.125 mmol/L), a whole-blood iCa threshold of ≤1.17 mmol/L resulted in the highest combined sensitivities (94 and 82%) and specificities (80 and 94%) at either threshold. Ionized Ca measurements were more consistently related to outcomes of neutrophil oxidative burst activity measured in vitro. The VetTest measurements of serum tCa reliably identified hypocalcemia when thresholds were adjusted to account for the bias of the test. The variation in the relationship between iCa and reference method tCa in the days following parturition suggest that these measures cannot be used interchangeably as indicators of Ca status. The more consistent associations between iCa and in vitro measures of neutrophil function, compared with tCa, indicated that this may be a more sensitive predictor of functional outcomes associated with postpartum Ca status.

The use of fortified foods to treat malnutrition among older adults: a systematic review

Purpose

Food fortification with common kitchen ingredients has been suggested to improve nutritional intake. The purpose of this paper was to systematically review the efficacy of food fortification on calorie and protein intake among older adults.

Design/methodology/approach

A systematic search was conducted using Boolean search logic and seven research databases to identify interventions using fortified foods to increase calorie and protein intake among older adults. Ten studies published in English since 1996 were eligible for inclusion. Study quality was evaluated using an adapted Modified Jadad Questionnaire.

Findings

Food fortification was associated with increased calorie intake in eight studies, increased protein intake in five studies, and increased body weight in three studies. However, studies were limited by lack of rigor in methodology and small sample sizes.

Originality/value

Food fortification may improve calorie and protein intake, but results are limited by study weaknesses. Additionally, it is unclear whether improved intake results in improved clinical outcomes.

Social Ecological Perspectives of Tube-Feeding Older Adults with Advanced Dementia: A Systematic Literature Review

Dementia is a progressive, debilitating disease that often results in weight loss, malnutrition, and dehydration. Feeding tubes are often prescribed; however, this practice can lead to complications. The purpose of this systematic review was to examine the use of feeding tubes in elderly demented patients from a social ecological perspective. Results indicated that family members often receive inadequate decision-making education. Many health care professionals lack knowledge of evidence-based guidelines pertaining to feeding tube use. Organizational and financial reimbursement structures influence feeding tube use. Feeding practices for patients with advanced dementia is a complex issue, warranting approaches that target each level of the Social Ecological Model.

College Students Must Overcome Barriers to Use Calorie Labels in Fast-Food Restaurants

OBJECTIVE

To explore predictors of intention of college students to use calorie labels on fast-food menus and differences in calories ordered after viewing calorie information.

DESIGN

Quasi-experimental design. Participants selected a meal from a menu without calorie labels, selected a meal from the same menu with calorie labels, and completed a survey that assessed demographics, dietary habits, Theory of Planned Behavior constructs, and potential barriers to use of calorie labeling.

SETTING

A southern university.

PARTICIPANTS

Undergraduate university students (n = 97).

MAIN OUTCOME MEASURES

Predictors of intention to use calorie labels and whether calories selected from the nonlabeled menu differed from the labeled menu.

ANALYSIS

Confirmatory factor analysis, exploratory factor analysis, multiple regression, and paired t tests.

RESULTS

Participants ordered significantly fewer calories (P = .02) when selecting from the labeled menu vs the menu without labels. Attitudes (P = .006), subjective norms (P < .001), and perceived behavioral control (P = .01) predicted intention to use calorie information but did not predict a difference in the calories ordered. Hunger (P = .03) and cost (P = .04) were barriers to using the calorie information.

CONCLUSIONS AND IMPLICATIONS

If students can overcome barriers, calorie labeling could provide information that college students need to select lower-calorie items at fast-food restaurants.

Circulating concentrations of bovine pregnancy-associated glycoproteins and late embryonic mortality in lactating dairy herds

The objectives of these experiments were as follows: (1) to determine the association between circulating concentrations of pregnancy-associated glycoproteins (PAG) and late embryonic mortality (EM) in lactating dairy cattle following fixed-time artificial insemination (TAI) on d 0 or timed embryo transfer (TET) on d 7, (2) to identify a circulating concentration of PAG on d 31 below which late EM would be likely to occur, and (3) to identify when during gestation (d 31-59) late EM is occurring. Cows were diagnosed pregnant on d 31 of gestation based on presence of a fetal heartbeat and reconfirmed to be pregnant on d 59 of gestation. Late EM occurred when a cow had a viable embryo on d 31 of gestation but not on d 59 following TAI or TET. Only pregnant cows on d 31 were included in the analysis (TAI-maintained, n=413; TAI-EM, n=77; TET-maintained, n=238; TET-EM, n=47). Cows that were pregnant at d 31 of gestation and maintained the pregnancy until d 59 had significantly higher circulating concentrations of PAG at d 31 of gestation compared with cows that experienced late EM between d 31 and 59 of gestation in both TAI and TET. To conduct a more stringent test of the effectiveness of a single circulating PAG concentration (d 31) to predict EM, a receiver-operating characteristic curve was generated to identify a PAG concentration on d 31 that would predict EM with ≥95% accuracy in cows that received TAI or TET. Based on positive and negative predicative value analysis, a circulating concentration of PAG below 1.4 ng/mL (TAI; minimal detectable level 0.28 ng/mL) and 1.85 ng/mL (TET) was 95% accurate in predicting EM (between d 31 and 59) at d 31 of gestation, respectively. Following TET, embryonic loss was tracked by Doppler ultrasound, progesterone, and PAG from d 24 to 59 of gestation, with more than 50% of the loss occurring between d 31 and 38 of gestation. In summary, circulating concentrations of PAG on d 31 of gestation may provide a good marker for predicting EM between d 31 and 59 of gestation, and the data suggest that this model could help predict which cows will undergo late EM.

Environmental Considerations for Improving Nutritional Status in Older Adults with Dementia: A Narrative Review

As the number of older adults in the United States continues to grow, the American health care system will face the unique challenge of providing care for these individuals, including many who will be diagnosed with some form of dementia. As dementia progresses, patients require increasing amounts of care and nutrient intake usually declines. This tends to result in weight loss, malnutrition, and increased morbidity and mortality. Various interventions have been developed with the goal of improving meal intake and reducing unintentional weight loss in patients with dementia. Several studies have shown that meal intake improves with the provision of adequate assistance, either from staff members or from volunteer feeding assistants. Some studies have focused on the method of meal service and its influence on meal intake and nutrition status. Both buffet-style and family-style dining have shown promising results in terms of improving meal intake and quality of life among older adults in long-term-care settings. Other environment-related interventions include improving lighting and visual contrast, altering the dining room to more closely resemble a home-style setting, using the aroma of food to stimulate appetite, using routine seating arrangements, and using relaxing or familiar music in the dining room to provide a calmer environment. The purpose of this review is to evaluate the research on environment-based interventions to improve nutritional status among older adults with dementia, to describe potential for practical applications, and to identify gaps in the existing literature whereon further research is warranted.

What proportion of preschool-aged children consume sweetened beverages?

BACKGROUND

Obesity affects nearly 17% of US children and youth 2-19 years old and 10% of infants and toddlers under the age of 2 years. One strategy for addressing obesity is to discourage sugar-sweetened beverage (SSB) consumption. Compared with their older school-aged counterparts, children ≤ 5 years depend largely on parents for the purchase and serving of SSBs. Therefore, recognizing parental factors associated with children's intake of SSBs is important.

METHODS

This study used cross-sectional data from parents of children ≤ 5 years old to examine SSB consumption and associated factors. Elements of the Health Belief Model and Theory of Reasoned Action facilitated data analysis and interpretation.

RESULTS

The most consistent predictor of SSB intake was child age. Nearly 94% of children aged 3-5 years consumed sweetened milk products, 88% consumed fruity drinks, 63% consumed sodas, and 56% consumed sports drinks and sweet tea. Adjusting for all other factors, the only parental psychosocial factor associated with SSB intake was self-efficacy (predicting fruity drinks consumption).

CONCLUSIONS

More children drink SSBs as they get older. Interventions designed to prevent SSB consumption should occur early, before children reach preschool age. Additional study of parental factors influencing SSB intake in early childhood is recommended.

A randomized controlled trial of a theoretically-based behavioral nutrition intervention for community elders: lessons learned from the Behavioral Nutrition Intervention for Community Elders Study

Older adults with multiple comorbidities are often undernourished or at high risk for becoming so, especially after a recent hospitalization. Randomized controlled trials of effective, innovative interventions are needed to support evidence-based approaches for solving nutritional problems in this population. Self-management approaches where participants select their own behavioral goals can enhance success of interventions. The purpose of this study was to evaluate the feasibility and efficacy of a multilevel self-management intervention to improve nutritional status in a group of high-risk older adults. The Behavioral Nutrition Intervention for Community Elders (B-NICE) trial used a prospective randomized controlled design to determine whether the intervention, compared to standard care, maintained or increased caloric intake (depending on baseline body mass index) and, consequently, stabilized or increased body weight. Participants were 34 Medicare-eligible, age 65 years old or older, homebound adults who were consuming insufficient calories and/or had a history of weight loss ≥2.5% over 6 months. The intervention took place within participants' homes. Outcome measures, including energy intake (based on collection of three 24-hour dietary recalls) and body weights were assessed at baseline and at 60 days post randomization. The primary analyses included analyses of covariance and Pearson's χ(2). We hypothesized that the intervention would result in increased caloric intake and weight gain in underweight older adults and increased or stabilized caloric intake and weight for everyone else. The intervention was feasible; however, it did not result in differences between groups for desired outcomes of either caloric intake or body weight. Future interventions might either deliberately involve caregivers or reduce burden for both patients and caregivers.

A theoretically based Behavioral Nutrition Intervention for Community Elders at high risk: the B-NICE randomized controlled clinical trial

We conducted a study designed to evaluate the efficacy and feasibility of a multilevel self-management intervention to improve nutritional intake in a group of older adults receiving Medicare home health services who were at especially high risk for experiencing undernutrition. The Behavioral Nutrition Intervention for Community Elders (B-NICE) trial used a prospective randomized controlled design to determine whether individually tailored counseling focused on social and behavioral aspects of eating resulted in increased caloric intake and improved nutrition-related health outcomes in a high-risk population of older adults. The study was guided by the theoretical approaches of the Ecological Model and Social Cognitive Theory. The development and implementation of the B-NICE protocol, including the theoretical framework, methodology, specific elements of the behavioral intervention, and assurances of the treatment fidelity, as well as the health policy implications of the trial results, are presented in this article.

Intramyocellular lipid and insulin resistance: differential relationships in European and African Americans

Insulin resistance has been associated with the accumulation of fat within skeletal muscle fibers as intramyocellular lipid (IMCL). Here, we have examined in a cross-sectional study the interrelationships among IMCL, insulin sensitivity, and adiposity in European Americans (EAs) and African Americans (AAs). In 43 EA and 43 AA subjects, we measured soleus IMCL content with proton-magnetic resonance spectroscopy, insulin sensitivity with hyperinsulinemic-euglycemic clamp, and body composition with dual-energy X-ray absorptiometry. The AA and EA subgroups had similar IMCL content, insulin sensitivity, and percent fat, but only in EA was IMCL correlated with insulin sensitivity (r = -0.47, P < 0.01), BMI (r = 0.56, P < 0.01), percent fat (r = 0.35, P < 0.05), trunk fat (r = 0.47, P < 0.01), leg fat (r = 0.40, P < 0.05), and waist and hip circumferences (r = 0.54 and 0.55, respectively, P < 0.01). In a multiple regression model including IMCL, race, and a race by IMCL interaction, the interaction was found to be a significant predictor (t = 1.69, DF = 1, P = 0.0422). IMCL is related to insulin sensitivity and adiposity in EA but not in AA, suggesting that IMCL may not function as a pathophysiological factor in individuals of African descent. These results highlight ethnic differences in the determinants of insulin sensitivity and in the pathogenesis of the metabolic syndrome trait cluster.

Relationship of intramyocellular lipid to insulin sensitivity may differ with ethnicity in healthy girls and women

The prevalence of type 2 diabetes is greater among African Americans (AA) vs. European Americans (EA), independent of obesity and lifestyle. We tested the hypothesis that intramyocellular lipid (IMCL) or extramycellular lipid (EMCL) would be associated with insulin sensitivity among healthy young women, and that the associations would differ with ethnic background. We also explored the hypothesis that adipokines and estradiol would be associated with muscle lipid content. Participants were 57 healthy, normoglycemic, women and girls mean age 26 (±10) years; mean BMI 27.3 (±4.8) kg/m²; 32 AA, 25 EA. Soleus IMCL and EMCL were assessed with ¹H magnetic resonance spectroscopy (MRS); insulin sensitivity with an insulin-modified frequently sampled intravenous glucose tolerance test and minimal modeling; body composition with dual-energy X-ray absorptiometry; and intra-abdominal adipose tissue (IAAT) with computed tomography. Adiponectin, leptin, and estradiol were assessed in fasting sera. Analyses indicated that EMCL, but not IMCL, was greater in AA vs. EA (2.55 ± 0.16 vs. 1.98 ± 0.18 arbitrary units, respectively, P < 0.05; adjusted for total body fat). IMCL was associated with insulin sensitivity in EA (r = -0.54, P < 0.05, adjusted for total fat, IAAT, and age), but not AA (r = 0.16, P = 0.424). IMCL was inversely associated with adiponectin (r = -0.31, P < 0.05, adjusted for ethnicity, age, total fat, and IAAT). In conclusion, IMCL was a significant determinant of insulin sensitivity among healthy, young, EA but not AA women. Further research is needed to determine whether the component lipids of IMCL (e.g., diacylglycerol (DAG) or ceramide) are associated with insulin sensitivity in an ethnicity specific manner.

Relationship between Insulin Sensitivity and Muscle Lipids may Differ with Muscle Group and Ethnicity

Intramyocellular lipid (IMCL) has been inversely associated with insulin sensitivity in some, but not all, studies. This study utilized fast, high-resolution, magnetic resonance spectroscopic imaging (MRSI) to: investigate relationships between muscle lipids (IMCL and extramyocellular lipid (EMCL)) and insulin sensitivity in muscles of varying oxidative capacity, explore ethnic differences in these relationships, and determine whether a eucaloric, low-fat dietary intervention would reduce IMCL and increase insulin sensitivity. Subjects were 30 healthy, African-American (AA; n=14) and European-American (EA; n=16) males, BMI 26.49 (±5.57) kg/m(2), age 21.80 (±7.84) yrs. Soleus and tibialis anterior muscle lipids were quantified using MRSI. Insulin sensitivity was assessed via intravenous glucose tolerance test. A 2-week, eucaloric, low-fat diet intervention was conducted in a sub-group (n=12) subjects with assessments at baseline and post-intervention. Neither IMCL nor EMCL levels differed between ethnicities. In the total group, and within EA (but not AA), both tibialis anterior IMCL and EMCL were inversely associated with insulin sensitivity (P<0.05 for both); soleus muscle lipids were not associated with insulin sensitivity. Soleus, but not tibialis anterior, IMCL declined in both ethnic groups (average 25.3%; p<0.01) following dietary intervention; insulin sensitivity was unchanged. Results suggest that an association of muscle lipids with insulin sensitivity may be influenced by the oxidative capacity of the muscle group studied and may vary with ethnicity.

Effects of short-term very low-calorie diet on intramyocellular lipid and insulin sensitivity in nondiabetic and type 2 diabetic subjects

The study aimed to analyze the effects of a short-term very low-calorie diet (VLCD) on intramyocellular lipid (IMCL), total body fat, and insulin sensitivity in a group of obese nondiabetic and type 2 diabetic subjects. Seven untreated type 2 diabetic and 5 obese nondiabetic individuals were studied before and after a 6-day VLCD using proton magnetic resonance spectroscopy to quantify IMCL, dual-energy x-ray absorptiometry to assess body fat, and hyperinsulinemic-euglycemic clamps to measure peripheral insulin sensitivity. In both groups, decrements in total body fat mass and body mass index were small but statistically significant. In contrast, the diet resulted in a pronounced reduction in IMCL compared with baseline values in nondiabetic subjects (56% decrease) and type 2 diabetic subjects (40% decrease) (P < .05), and this was accompanied by an overall 9.3% increase in maximally stimulated glucose disposal rate (P < .01). Intramyocellular lipid was significantly correlated with insulin sensitivity (r = -0.69, P < .01) and waist circumference (r = 0.72 and 0.83, baseline and postdiet, respectively; both P < .01), but neither IMCL nor insulin sensitivity was related to measures of general adiposity such as body mass index, percentage of body fat, or total body fat (P = not significant). In conclusion, short-term VLCD is accompanied by small decrements in general adiposity, marked decrease in IMCL, and an increase in insulin sensitivity in nondiabetic and type 2 diabetic subjects. Therefore, rapid amelioration of insulin resistance by VLCD can be partially explained by loss of IMCL both in nondiabetic and type 2 diabetic subjects in the absence of substantial changes in total body fat. These observations are consistent with the idea that insulin resistance is more directly related to IMCL rather than to body fat per se.

High-resolution chemical shift imaging for the assessment of intramuscular lipids

A new high-resolution MRSI technique was used to measure extracellular lipids (EMCL), intracellular lipids (IMCL), and total muscle lipids (TML). The purpose of this study was to assess the feasibility and reproducibility of this new technique. This study also compared results obtained from small regions of interest (ROIs) vs. a summation of a large ROI of voxels representing the total soleus or anterior tibialis (TA) muscles. Eight volunteers were studied with the use of a conventional single-slice MR spectroscopic imaging (MRSI) sequence run with the following parameters: TR = 145.9 ms, FOV = 16 cm, slice thickness = 1 cm, and 64 x 64 phase encodes. EMCL, IMCL, and TML values from the small ROIs proved to be reproducible (coefficient of variation (CV) = 7.8-13.8% for soleus, and 8.2-18% for TA). EMCL, IMCL, and TML values from the larger soleus ROI proved to be reproducible (CV = 7.3-16.1%), whereas the larger TA ROIs were less reproducible. The small and larger soleus ROIs produced statistically equivalent measures of EMCL and TML per unit area. However, the small soleus and TA ROIs showed a trend toward yielding different IMCL contents as compared to the larger ROIs. This study demonstrates that high-resolution 1H MRSI of the calf muscle is feasible and can reproducibly measure EMCL, IMCL, and TML.

Ability of the Harris Benedict formula to predict energy requirements differs with weight history and ethnicity

The objective of this study was to assess the effects of weight history status and ethnicity on the ability of the Harris Benedict (HB) formula to: 1) predict measured resting energy expenditure (REE), and, 2) accurately estimate energy needs over a 2-week test period. Subjects were never-overweight (BMI </= 25 kg/m(2), n=47), overweight (BMI 27-30 kg/m(2), n=170), and weight-reduced (BMI </= 25 kg/m(2), n=51) healthy, adult African-American (AA) and Caucasian (C) women. Food was provided for 2 weeks at an energy level calculated using the HB formula multiplied by a 1.35 activity factor. After 2 weeks, weight, REE (by indirect calorimetry), and body composition (by dual-energy X-ray absorptiometry) were assessed. Data were analyzed using 2-way ANOVA at p<0.05 significance. The HB formula overestimated REE 1) in each weight history group (by 160 +/-125 kcals among never-overweight, 295 +/-189 kcal among overweight, and 105 +/-135 among weight-reduced) such that there was a group effect on overestimation (P<0.001) and 2) between ethnicities, with a greater overestimation in AA vs. C (P<0.001). There was a significant effect of weight history group on weight change (P<0.001) over 2-weeks, such that weight-reduced women gained more weight than the other two groups (P<0.05). In conclusion, the ability of the HB formula to estimate REE differed with weight history status and ethnicity. The accuracy of the HB formula to predict dietary energy needs was affected by weight history status. These results suggest that formulas used to calculate energy needs should take into account weight history and ethnicity.

Syntaxin is efficiently excluded from sphingomyelin-enriched domains in supported lipid bilayers containing cholesterol

Formation of a trans-complex between the three SNARE proteins syntaxin, synaptobrevin and SNAP-25 drives membrane fusion. The structure of the core SNARE complex has been studied extensively. Here we have used atomic force microscopy to study the behavior of recombinant syntaxin 1A both in detergent extracts and in a lipid environment. Full-length syntaxin in detergent extracts had a marked tendency to aggregate, which was countered by addition of munc-18. In contrast, syntaxin lacking its transmembrane region was predominantly monomeric. Syntaxin could be integrated into liposomes, which formed lipid bilayers when deposited on a mica support. Supported bilayers were decorated with lipid vesicles in the presence, but not the absence, of full-length syntaxin, indicating that formation of syntaxin complexes in trans could mediate vesicle docking. Syntaxin complexes remained at the sites of docking following detergent solubilization of the lipids. Raised lipid domains could be seen in bilayers containing sphingomyelin, and these domains were devoid of syntaxin and docked vesicles in the presence, but not the absence, of cholesterol. Our results demonstrate that syntaxin is excluded from sphingomyelin-enriched domains in a cholesterol-dependent manner.

Modulation of the Protein Kinase Activity of mTOR

mTOR is a founding member of a family of protein kinases having catalytic domains homologous to those in phosphatidylinositol 3-OH kinase. mTOR participates in the control by insulin of the phosphorylation of lipin, which is required for adipocyte differentiation, and the two translational regulators, p70S6K and PHAS-I. The phosphorylation of mTOR, itself, is stimulated by insulin in Ser2448, a site that is also phosphorylated by protein kinase B (PKB) in vitro and in response to activation of PKB activity in vivo. Ser2448 is located in a short stretch of amino acids not found in the two TOR proteins in yeast. A mutant mTOR lacking this stretch exhibited increased activity, and binding of the antibody, mTAb-1, to this region markedly increased mTOR activity. In contrast, rapamycin-FKBP12 inhibited mTOR activity towards both PHAS-I and p70S6K, although this complex inhibited the phosphorylation of some sites more than that of others. Mutating Ser2035 to Ile in the FKBP12-rapamycin binding domain rendered mTOR resistant to inhibition by rapamycin. Unexpectedly, this mutation markedly decreased the ability of mTOR to phosphorylate certain sites in both PHAS-I and p70S6K. The results support the hypotheses that rapamycin disrupts substrate recognition instead of directly inhibiting phosphotransferase activity and that mTOR activity in cells is controlled by the phosphorylation of an inhibitory regulatory domain containing the mTAb-1 epitope.

mTOR-dependent control of skeletal muscle protein synthesis

Muscle mass is influenced by many factors including genetically programmed changes, hormonal state, level of activity, and disease processes. Ultimately, whether or not a muscle hypertrophies or atrophies is determined by a simple relationship between the rates of protein synthesis and degradation. When synthesis exceeds degradation, the muscle hypertrophies, and vice versa. In contrast to this simple relationship, the processes that control muscle protein synthesis and degradation are complex. Recently, significant progress has been made in understanding the biochemical mechanisms that control the rate of translation initiation, which is generally the limiting phase in protein synthesis.

Akt/mTOR pathway is a crucial regulator of skeletal muscle hypertrophy and can prevent muscle atrophy in vivo

Skeletal muscles adapt to changes in their workload by regulating fibre size by unknown mechanisms. The roles of two signalling pathways implicated in muscle hypertrophy on the basis of findings in vitro, Akt/mTOR (mammalian target of rapamycin) and calcineurin/NFAT (nuclear factor of activated T cells), were investigated in several models of skeletal muscle hypertrophy and atrophy in vivo. The Akt/mTOR pathway was upregulated during hypertrophy and downregulated during muscle atrophy. Furthermore, rapamycin, a selective blocker of mTOR, blocked hypertrophy in all models tested, without causing atrophy in control muscles. In contrast, the calcineurin pathway was not activated during hypertrophy in vivo, and inhibitors of calcineurin, cyclosporin A and FK506 did not blunt hypertrophy. Finally, genetic activation of the Akt/mTOR pathway was sufficient to cause hypertrophy and prevent atrophy in vivo, whereas genetic blockade of this pathway blocked hypertrophy in vivo. We conclude that the activation of the Akt/mTOR pathway and its downstream targets, p70S6K and PHAS-1/4E-BP1, is requisitely involved in regulating skeletal muscle fibre size, and that activation of the Akt/mTOR pathway can oppose muscle atrophy induced by disuse.

Insulin control of glycogen metabolism in knockout mice lacking the muscle-specific protein phosphatase PP1G/RGL

The regulatory-targeting subunit (RGL), also called GM) of the muscle-specific glycogen-associated protein phosphatase PP1G targets the enzyme to glycogen where it modulates the activity of glycogen-metabolizing enzymes. PP1G/RGL has been postulated to play a central role in epinephrine and insulin control of glycogen metabolism via phosphorylation of RGL. To investigate the function of the phosphatase, RGL knockout mice were generated. Animals lacking RGL show no obvious defects. The RGL protein is absent from the skeletal and cardiac muscle of null mutants and present at approximately 50% of the wild-type level in heterozygotes. Both the level and activity of C1 protein are also decreased by approximately 50% in the RGL-deficient mice. In skeletal muscle, the glycogen synthase (GS) activity ratio in the absence and presence of glucose-6-phosphate is reduced from 0.3 in the wild type to 0.1 in the null mutant RGL mice, whereas the phosphorylase activity ratio in the absence and presence of AMP is increased from 0.4 to 0.7. Glycogen accumulation is decreased by approximately 90%. Despite impaired glycogen accumulation in muscle, the animals remain normoglycemic. Glucose tolerance and insulin responsiveness are identical in wild-type and knockout mice, as are basal and insulin-stimulated glucose uptakes in skeletal muscle. Most importantly, insulin activated GS in both wild-type and RGL null mutant mice and stimulated a GS-specific protein phosphatase in both groups. These results demonstrate that RGL is genetically linked to glycogen metabolism, since its loss decreases PP1 and basal GS activities and glycogen accumulation. However, PP1G/RGL is not required for insulin activation of GS in skeletal muscle, and rather another GS-specific phosphatase appears to be involved.

PHAS proteins as mediators of the actions of insulin, growth factors and cAMP on protein synthesis and cell proliferation

PHAS-I and PHAS-II are members of a newly discovered family of proteins that regulate translation initiation. PHAS-I is expressed in a wide variety of cell types, but it is highest in adipocytes, where protein synthesis is markedly increased by insulin. PHAS-II is highest in liver and kidney, where very little PHAS-I is found. PHAS proteins bind to eIF-4E, the mRNA cap-binding protein, and inhibit translation of capped mRNA in vitro and in cells. In rat adipocytes PHAS-I is phosphorylated in at least five sites, all of which conform to the consensus, (Ser/Thr)-Pro. Both PHAS proteins are phosphorylated in response to insulin or growth factors, such as EGF, PDGF and IGF-1. Phosphorylation in the appropriate site(s) promotes dissociation of PHAS/eIF-4E complexes. This allows eIF-4E to bind to eIF-4G (p220), thereby increasing the amount of the eIF-4F complex and the rate of translation initiation. Increasing cAMP promotes PHAS-I dephosphorylation and increases binding to eIF-4E. Unlike PHAS-I, PHAS-II is readily phosphorylated by PKA in vitro, suggesting that regulation of the two proteins differs. However, increasing cAMP in cells also promotes dephosphorylation of PHAS-II. Thus, PHAS proteins appear to be key mediators not only of the stimulatory effects of insulin and growth factors on protein synthesis, but also of the inhibitory effects of cAMP. Moreover, by controlling eIF-4E PHAS proteins may be involved in the control of cell proliferation, as increasing eIF-4E is mitogenic and can even cause malignant transformation of cells. MAP kinase readily phosphorylates both PHAS-I and PHAS-II in vitro, but inhibiting activation of MAP kinase does not attenuate the effects of insulin on increasing phosphorylation of the PHAS proteins in adipocytes or skeletal muscle. MAP kinase phosphorylates neither PHAS-I nor PHAS-II at a significant rate when the proteins are bound to eIF-4E. Therefore, the role of MAP kinase in promoting the dissociation of PHAS/eIF-4E complexes is not clear. Of several protein kinases tested, only casein kinase-II phosphorylated PHAS-I when it was bound eIF-4E. Indeed, the bound form of PHAS-I was phosphorylated more rapidly than the free form. However, it is unlikely that casein kinase II regulates either PHAS protein, as the major site (Ser111) in PHAS-I phosphorylated by casein kinase II in vitro is not phosphorylated in adipocytes, and PHAS-II is not a substrate for casein kinase-II. Pharmacological and genetic evidence indicates that the mTOR/p70S6K pathway is involved in the control of PHAS-I and -II. Thus, PHAS proteins may be mediators of the effects of this pathway on protein synthesis and cell proliferation.

In defence of in-vitro tests

The Editor welcomes letters relating to published work or other subjects relevant to wound care. These may be edited. Please send your letters to the Editor, Journal of Wound Care, Greater London House, Hampstead Road, London NW1 7EJ, or via email jwc@emap.com

Protection against oxidative stress-induced insulin resistance in rat L6 muscle cells by mircomolar concentrations of alpha-lipoic acid

In diabetic patients, alpha-lipoic acid (LA) improves skeletal muscle glucose transport, resulting in increased glucose disposal; however, the molecular mechanism of action of LA is presently unknown. We studied the effects of LA on basal and insulin-stimulated glucose transport in cultured rat L6 muscle cells that overexpress GLUT4. When 2-deoxy-D-glucose uptake was measured in these cells, they were more sensitive and responsive to insulin than wild-type L6 cells. LA, at concentrations < or = 1 mmol/l, had only small effects on glucose transport in cells not exposed to oxidative stress. When cells were exposed to glucose oxidase and glucose to generate H2O2 and cause oxidative stress, there was a marked decrease in insulin-stimulated glucose transport. Pretreatment with LA over the concentration range of 10-1,000 pmol/l protected the insulin effect from inhibition by H2O2. Both the R and S isomers of LA were equally effective. In addition, oxidative stress caused a significant decrease (approximately 50%) in reduced glutathione concentration, along with the rapid activation of the stress-sensitive p38 mitogen-activated protein kinase. Pretreatment with LA prevented both of these events, coincident with protecting insulin action. These studies indicate that in muscle, the major site of insulin-stimulated glucose disposal, one important effect of LA on the insulin-signaling cascade is to protect cells from oxidative stress-induced insulin resistance.

Partial isolation and characterization of a cysteine proteinase inhibitor from Lima bean (Phaseolus lunatus)

Lima beans (Phaseolus lunatus) have been shown to contain cysteine proteinase inhibitor (CPI) activity, but the CPI has not been isolated or characterized. Accordingly, our objective was to isolate and partially characterize a CPI from lima bean. The isolation scheme included water extraction of lima bean flour followed by a chromatography series using DEAE Sepharose, Phenyl Sepharose, hydroxyapatite, and reversed-phase high performance liquid chromatography. This scheme resulted in the partial purification of a approximately 20 000-dalton protein with high inhibitory activity against papain. This isolated lima bean CPI had an N-terminal sequence homologous with other members of the cystatin class of CPIs. The protein was relatively heat labile; suggesting it could be inactivated with normal cooking, which is favorable for its use in transforming plants to create insect resistance.

Mammalian target of rapamycin-dependent phosphorylation of PHAS-I in four (S/T)P sites detected by phospho-specific antibodies

The role and control of the four rapamycin-sensitive phosphorylation sites that govern the association of PHAS-I with the mRNA cap-binding protein, eukaryotic initiation factor 4E (eIF4E), were investigated by using newly developed phospho-specific antibodies. Thr(P)-36/45 antibodies reacted with all three forms of PHAS-I that were resolved when cell extracts were subjected to SDS-polyacrylamide gel electrophoresis. Thr(P)-69 antibodies bound the forms of intermediate and lowest mobility, and Ser(P)-64 antibodies reacted only with the lowest mobility form. A portion of PHAS-I that copurified with eIF4E reacted with Thr(P)-36/45 and Thr(P)-69 antibodies but not with Ser(P)-64 antibodies. Insulin and/or amino acids increased, and rapamycin decreased, the reactivity of all three antibodies with PHAS-I in both HEK293 cells and 3T3-L1 adipocytes. Immunoprecipitated epitope-tagged mammalian target of rapamycin (mTOR) phosphorylated Thr-36/45. mTOR also phosphorylated Thr-69 and Ser-64 but only when purified immune complexes were incubated with the activating antibody, mTAb1. Interestingly, the phosphorylation of Thr-69 and Ser-64 was much more sensitive to inhibition by rapamycin-FKBP12 than the phosphorylation of Thr-36/45, and the phosphorylation of Ser-64 by mTOR was facilitated by phosphorylation of Thr-36, Thr-45, and Thr-69. In these respects the phosphorylation of PHAS-I by mTOR in vitro resembles the ordered phosphorylation of PHAS-I in cells.

Investigating the bacterial barrier properties of four contemporary wound dressings

The ability of four wound dressings (CombiDERM, Allevyn Hydrocellular, Tegaderm and Tielle) to resist penetration of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecalis and Pseudomonas aeruginosa was investigated in vitro using a dedicated test apparatus. With the exception of Tielle, each dressing prevented bacterial transmission over an 11-day challenge period. When both the wound contact surface and the external surface of Tielle were directly challenged with a bacterial suspension, penetration of the dressing was observed within three to five days. The breakdown of its outer membrane could explain the inability of Tielle to maintain a barrier to the passage of the test bacteria used in this wound model. On the basis of these data, CombiDERM, Allevyn Hydrocellular and Tegaderm dressings may facilitate infection control by acting as a physical barrier to the transmission of potentially pathogenic and antibiotic-resistant wound bacteria. However, further research is urgently required to determine whether or not the same results are observed in clinical practice.

Multiple mechanisms control phosphorylation of PHAS-I in five (S/T)P sites that govern translational repression

Control of the translational repressor, PHAS-I, was investigated by expressing proteins with Ser/Thr --> Ala mutations in the five (S/T)P phosphorylation sites. Results of experiments with HEK293 cells reveal at least three levels of control. At one extreme is nonregulated phosphorylation, exemplified by constitutive phosphorylation of Ser82. At an intermediate level, amino acids and insulin stimulate the phosphorylation of Thr36, Thr45, and Thr69 via mTOR-dependent processes that function independently of other sites in PHAS-I. At the third level, the extent of phosphorylation of one site modulates the phosphorylation of another. This control is represented by Ser64 phosphorylation, which depends on the phosphorylation of all three TP sites. The five sites have different influences on the electrophoretic properties of PHAS-I and on the affinity of PHAS-I for eukaryotic initiation factor 4E (eIF4E). Phosphorylation of Thr45 or Ser64 results in the most dramatic decreases in eIF4E binding in vitro. However, each of the sites influences mRNA translation, either directly by modulating the binding affinity of PHAS-I and eIF4E or indirectly by affecting the phosphorylation of other sites.

Factors associated with length of stay in a mid-sized, urban hospice

A recent study by Frantz et al. investigated the relationship between length of stay (LOS) and several factors in a small, rural hospice and found significant differences in LOS by primary physician specialty, referral source, and diagnosis (American Journal of Hospice & Palliative Care, March/April 1999). The purpose of the present study was to replicate and extend the Frantz et al. study in a midsized, urban hospice setting and to examine the relationship of LOS with additional variables, such as living status, discharge status, race, and religion. Significant differences in LOS by gender, diagnosis, physician specialty, referral source, type of insurance, living status, and discharge status were found. No significant differences in LOS were found by race, religion, and place of death. Results are interpreted in the light of previous research findings regarding LOS and in the context of the sample size. Strategies are suggested for increasing patients' LOS.

Control of glycogen synthesis is shared between glucose transport and glycogen synthase in skeletal muscle fibers

The effects of transgenic overexpression of glycogen synthase in different types of fast-twitch muscle fibers were investigated in individual fibers from the anterior tibialis muscle. Glycogen synthase was severalfold higher in all transgenic fibers, although the extent of overexpression was twofold greater in type IIB fibers. Effects of the transgene on increasing glycogen and phosphorylase and on decreasing UDP-glucose were also more pronounced in type IIB fibers. However, in any grouping of fibers having equivalent malate dehydrogenase activity (an index of oxidative potential), glycogen was higher in the transgenic fibers. Thus increasing synthase is sufficient to enhance glycogen accumulation in all types of fast-twitch fibers. Effects on glucose transport and glycogen synthesis were investigated in experiments in which diaphragm, extensor digitorum longus (EDL), and soleus muscles were incubated in vitro. Transport was not increased by the transgene in any of the muscles. The transgene increased basal [(14)C]glucose into glycogen by 2.5-fold in the EDL, which is composed primarily of IIB fibers. The transgene also enhanced insulin-stimulated glycogen synthesis in the diaphragm and soleus muscles, which are composed of oxidative fiber types. We conclude that increasing glycogen synthase activity increases the rate of glycogen synthesis in both oxidative and glycolytic fibers, implying that the control of glycogen accumulation by insulin in skeletal muscle is distributed between the glucose transport and glycogen synthase steps.

Inhibitor-1 is not required for the activation of glycogen synthase by insulin in skeletal muscle

Glycogen synthase is an excellent in vitro substrate for protein phosphatase-1 (PP1), which is potently inhibited by the phosphorylated forms of DARPP-32 (dopamine- and cAMP-regulated phosphoprotein, M(r) = 32,000) and Inhibitor-1. To test the hypothesis that the activation of glycogen synthase by insulin is due to a decrease in the inhibition of PP1 by the phosphatase inhibitors, we have investigated the effects of insulin on glycogen synthesis in skeletal muscles from wild-type mice and mice lacking Inhibitor-1 and DARPP-32 as a result of targeted disruption of the genes encoding the two proteins. Insulin increased glycogen synthase activity and the synthesis of glycogen to the same extent in wild-type and knockout mice, indicating that neither Inhibitor-1 nor DARPP-32 is required for the full stimulatory effects of insulin on glycogen synthase and glycogen synthesis in skeletal muscle.

Mutational analysis of sites in the translational regulator, PHAS-I, that are selectively phosphorylated by mTOR

Results obtained with PHAS-I proteins having Ser to Ala mutations in the five known phosphorylation sites indicate that mTOR preferentially phosphorylates Thr36 and Thr45. The effects of phosphorylating these sites on eIF4E binding were assessed in a far-Western analysis with a labeled eIF4E probe. Phosphorylation of Thr36 only slightly attenuated binding of PHAS-I to eIF4E, while phosphorylation of Thr45 markedly inhibited binding. Phosphorylation of neither site affected the electrophoretic mobility of the protein, indicating that results of studies that rely solely on a gel-shift assay to assess changes in PHAS-I phosphorylation must be interpreted with caution.

Swab taking

Experienced clinicians offer top tips to guide practice on specific wound-care issues.

Honey and wound bacteria

Chronic wounds pose a microbiological dilemma. Bacterial acquisition by acute skin wounds can be significantly minimised by prophylaxis with topical antiseptics such as chlorhexidine, povidone- iodine or silver compounds. However, such prophylaxis is probably impractical for chronic wounds which, by nature, have a protracted duration, and frequently develop insidiously. Consequently such wounds are colonised with a wide variety of bacterial species, many of which are potentially pathogenic. It is often unclear whether wounds so colonised are infected since often there is little obvious evidence of sepsis. However, it may be pertinent to note that tissues are normally bacteria free; moreover, in the absence of a microbiological flora, sepsis cannot develop nor can cross-infection occur.

Factors in hospice patients' length of stay

Many hospice patients are referred comparatively late in the course of their disease progression, therefore minimizing the time of services to the patient, caregivers, and families. Untimely referrals can create organizational, clinical, and emotional problems for all involved; a better understanding of the factors related to length of stay (LOS) in hospice is necessary. This study investigated the relationship between LOS and selected variables. There were significant differences in LOS by diagnosis, physician type, and referral source. No significant differences were found in LOS by gender or insurance type. Factors related to LOS can assist hospices in identifying those particular patients more likely to have longer stays. Additionally, administrators may tailor their programs to meet the needs of the individual hospice.

Attenuation of mammalian target of rapamycin activity by increased cAMP in 3T3-L1 adipocytes

Incubating 3T3-L1 adipocytes with forskolin, which increases intracellular cAMP by activating adenylate cyclase, mimicked rapamycin by attenuating the effect of insulin on stimulating the phosphorylation of four (S/T)P sites in PHAS-I, a downstream target of the mammalian target of rapamycin (mTOR) signaling pathway. To investigate the hypothesis that increasing cAMP inhibits mTOR, the protein kinase activity of mTOR was measured in an immune complex assay with recombinant PHAS-I as substrate. Both forskolin and 8-(4-chlorophenylthio)adenosine 3'-5'-monophosphate (CPT-cAMP) prevented the activation of mTOR by insulin in adipocytes, but neither agent affected mTOR activity when added directly to the immunopurified protein. In contrast, the cAMP phosphodiesterase inhibitor, theophylline, inhibited mTOR activity not only when added to intact adipocytes but also when added to immunopurified mTOR in vitro, demonstrating that certain methylxanthines are able to inhibit mTOR independently of increasing cAMP. Forskolin and CPT-cAMP blocked the effect of insulin on increasing mTOR phosphorylation, which was assessed using mTAb1, an antibody whose binding is inhibited by phosphorylation of mTOR. Although the mTAb1 epitope contains a consensus site for protein kinase B, neither agent inhibited the activation of protein kinase B produced by insulin. These findings support the interpretation that increasing cAMP attenuates the effects of insulin on PHAS-I, p70(S6K), and other downstream targets of the mTOR signaling pathway by inhibiting the phosphorylation and activation of mTOR.