Review of the literature and suggestions for the design of rodent survival studies for the identification of compounds that increase health and life span

Much of the literature describing the search for agents that increase the life span of rodents was found to suffer from confounds. One-hundred-six studies, absent 20 contradictory melatonin studies, of compounds or combinations of compounds were reviewed. Only six studies reported both life span extension and food consumption data, thereby excluding the potential effects of caloric restriction. Six other studies reported life span extension without a change in body weight. However, weight can be an unreliable surrogate measure of caloric consumption. Twenty studies reported that food consumption or weight was unchanged, but it was unclear whether these data were anecdotal or systematic. Twenty-nine reported extended life span likely due to induced caloric restriction. Thirty-six studies reported no effect on life span, and three a decrease. The remaining studies suffer from more serious confounds. Though still widely cited, studies showing life span extension using short-lived or “enfeebled” rodents have not been shown to predict longevity effects in long-lived animals. We suggest improvements in experimental design that will enhance the reliability of the rodent life span literature. First, animals should receive measured quantities of food and its consumption monitored, preferably daily, and reported. Weights should be measured regularly and reported. Second, a genetically heterogeneous, long-lived rodent should be utilized. Third, chemically defined diets should be used. Fourth, a positive control (e.g., a calorically restricted group) is highly desirable. Fifth, drug dosages should be chosen based on surrogate endpoints or accepted cross-species scaling factors. These procedures should improve the reliability of the scientific literature and accelerate the identification of longevity and health span-enhancing agents

A prospective study of nutrition education and oral nutritional supplementation in patients with Alzheimer's disease

<p>Abstract</p> <p>Background</p> <p>Weight loss in patients with Alzheimer's disease (AD) is a common clinical manifestation that may have clinical significance.</p> <p>Objectives</p> <p>To evaluate if there is a difference between nutrition education and oral nutritional supplementation on nutritional status in patients with AD.</p> <p>Methods</p> <p>A randomized, prospective 6-month study which enrolled 90 subjects with probable AD aged 65 years or older divided into 3 groups: Control Group (CG) [n = 27], Education Group (EG) [n = 25], which participated in an education program and Supplementation Group (SG) [n = 26], which received two daily servings of oral nutritional supplementation. Subjects were assessed for anthropometric data (weight, height, BMI, TSF, AC and AMC), biochemical data (total protein, albumin, and total lymphocyte count), CDR (Clinical Dementia Rating), MMSE (Mini-mental state examination), as well as dependence during meals.</p> <p>Results</p> <p>The SG showed a significant improvement in the following anthropometric measurements: weight (H calc = 22.12, p =< 0.001), BMI (H calc = 22.12, p =< 0.001), AC (H calc = 12.99, p =< 0.002), and AMC (H calc = 8.67, p =< 0.013) compared to the CG and EG. BMI of the EG was significantly greater compared to the CG. There were significant changes in total protein (H calc = 6.17, p =< 0.046), and total lymphocyte count in the SG compared to the other groups (H cal = 7.94, p = 0.019).</p> <p>Conclusion</p> <p>Oral nutritional supplementation is more effective compared to nutrition education in improving nutritional status.</p

Type D personality is associated with increased metabolic syndrome prevalence and an unhealthy lifestyle in a cross-sectional Dutch community sample

<p>Abstract</p> <p>Background</p> <p>People with Type D-Distressed-personality have a general tendency towards increased negative affectivity (NA), while at the same time inhibiting these emotions in social situations (SI). Type D personality is associated with an increased risk of adverse outcomes in patients with cardiovascular disease. Whether Type D personality is a cardiovascular risk factor in healthy populations remains to be investigated. In the present study, the relations between Type D personality and classical cardiovascular risk factors, i.e. metabolic syndrome and lifestyle were investigated in a Dutch community sample.</p> <p>Methods</p> <p>In a cross-sectional study 1592 participants were included, aged 20-80 years. Metabolic syndrome was defined by self-report, following the International Diabetes Federation-IDF-guidelines including an increased waist circumference, dyslipidemia, hypertension, and diabetes. In addition lifestyle factors smoking, alcohol use, exercise and dietary habits were examined. Metabolic syndrome prevalence was stratified by Type D personality (a high score on both NA and SI), lifestyle and confounders age, gender, having a partner, higher education level, cardiac history, family history of cardiovascular disease.</p> <p>Results</p> <p>Metabolic syndrome was more prevalent in persons with a Type D personality (13% vs. 6%). Persons with Type D personality made poorer lifestyle choices, adhered less to the physical activity norm (OR = 1.5, 95%CI = 1.1-2.0, <it>p </it>= .02), had a less varied diet (OR = 0.50, 95%CI = 0.40-0.70, <it>p </it>< .0005), and were less likely to restrict their fat intake (OR = 0.70, 95%CI = 0.50-0.90, <it>p </it>= .01). Type D personality was related to a twofold increased risk of metabolic syndrome (OR = 2.2, 95%CI = 1.2-4.0, <it>p </it>= .011), independent of lifestyle factors and confounders.</p> <p>Conclusions</p> <p>Type D personality is related to an increased prevalence of metabolic syndrome and unhealthy lifestyle, which suggests both behavioral and biological vulnerability for development of cardiovascular disorders and diabetes.</p

Preliminary Evidence for the Cross-Cultural Utility of the Type D Personality Construct in the Ukraine

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Validity of Type D personality in Iceland: association with disease severity and risk markers in cardiac patients

Type D personality has been associated with poor prognosis in cardiac patients. This study investigated the validity of the Type D construct in Iceland and its association with disease severity and health-related risk markers in cardiac patients. A sample of 1,452 cardiac patients completed the Type D scale (DS14), and a subgroup of 161 patients completed measurements for the five-factor model of personality, emotional control, anxiety, depression, stress and lifestyle factors. The Icelandic DS14 had good psychometric properties and its construct validity was confirmed. Prevalence of Type D was 26–29%, and assessment of Type D personality was not confounded by severity of underlying coronary artery disease. Regarding risk markers, Type D patients reported more psychopharmacological medication use and smoking, but frequency of previous mental problems was similar across groups. Type D is a valid personality construct in Iceland, and is associated with health-related risk markers, but not cardiac disease severity

Myocardial energy depletion and dynamic systolic dysfunction in hypertrophic cardiomyopathy

Evidence indicates that anatomical and physiological phenotypes of hypertrophic cardiomyopathy (HCM) stem from genetically mediated, inefficient cardiomyocyte energy utilization, and subsequent cellular energy depletion. However, HCM often presents clinically with normal left ventricular (LV) systolic function or hyperkinesia. If energy inefficiency is a feature of HCM, why is it not manifest as resting LV systolic dysfunction? In this Perspectives article, we focus on an idiosyncratic form of reversible systolic dysfunction provoked by LV obstruction that we have previously termed the 'lobster claw abnormality' — a mid-systolic drop in LV Doppler ejection velocities. In obstructive HCM, this drop explains the mid-systolic closure of the aortic valve, the bifid aortic pressure trace, and why patients cannot increase stroke volume with exercise. This phenomenon is characteristic of a broader phenomenon in HCM that we have termed dynamic systolic dysfunction. It underlies the development of apical aneurysms, and rare occurrence of cardiogenic shock after obstruction. We posit that dynamic systolic dysfunction is a manifestation of inefficient cardiomyocyte energy utilization. Systolic dysfunction is clinically inapparent at rest; however, it becomes overt through the mechanism of afterload mismatch when LV outflow obstruction is imposed. Energetic insufficiency is also present in nonobstructive HCM. This paradigm might suggest novel therapies. Other pathways that might be central to HCM, such as myofilament Ca2+ hypersensitivity, and enhanced late Na+ current, are discussed

Evidence-based Kernels: Fundamental Units of Behavioral Influence

This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior

Liquid biopsies come of age: towards implementation of circulating tumour DNA

Improvements in genomic and molecular methods are expanding the range of potential applications for circulating tumour DNA (ctDNA), both in a research setting and as a ‘liquid biopsy’ for cancer management. Proof-of-principle studies have demonstrated the translational potential of ctDNA for prognostication, molecular profiling and monitoring. The field is now in an exciting transitional period in which ctDNA analysis is beginning to be applied clinically, although there is still much to learn about the biology of cell-free DNA. This is an opportune time to appraise potential approaches to ctDNA analysis, and to consider their applications in personalized oncology and in cancer research.We would like to acknowledge the support of The University of Cambridge, Cancer Research UK (grant numbers A11906, A20240, A15601) (to N.R., J.D.B.), the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement n. 337905 (to N.R.), the Cambridge Experimental Cancer Medicine Centre, and Hutchison Whampoa Limited (to N.R.), AstraZeneca (to R.B., S.P.), the Cambridge Experimental Cancer Medicine Centre (ECMC) (to R.B., S.P.), and NIHR Biomedical Research Centre (BRC) (to R.B., S.P.). J.G.C. acknowledges clinical fellowship support from SEOM