Magnesium supplementation and muscle function in patients with alcoholic liver disease: a randomized, placebo-controlled trial

OBJECTIVE: The study was undertaken in order to evaluate the effect of magnesium (Mg) supplementation on muscle contents of Mg, muscle strength, muscle mass and sodium, potassium pumps (Na,K-pumps) in patients with alcoholic liver disease. Retrospectively, patients were also stratified according to spironolactone treatment. MATERIAL AND METHODS: The study comprised a placebo-controlled, randomized trial in which 59 consecutive patients with alcoholic liver disease were treated with Mg intravenously and orally (12.5 mmol daily) or placebo for 6 weeks. Muscle content of Mg, maximum isokinetic muscle strength, skeletal muscle mass and muscle content of Na,K-pumps were measured before and after Mg supplementation. RESULTS: Muscle Mg did not increase during the trial (paired t-test), but Mg supplementation and the duration of pre-study spironolactone treatment were independent predictors of muscle Mg (multiple regression). Muscle strength increased by 14% during the trial (p<0.001) and muscle mass increased by 11% (p=0.05), but with no difference between placebo and Mg treatment. Spironolactone treatment was associated with a 33% increase in the content of Na,K-pumps (p<0.001). CONCLUSIONS: Six weeks of Mg supplementation did not increase muscle Mg, although Mg supplementation and spironolactone treatment were independent predictors of muscle Mg. The intervention had no effect on muscle strength and mass, but both increased during the study, probably owing to the general care and attendance to the patients.     

Are communication activities shaped by environmental constraints in reverberating and absorbing forest habitats?

In the dense vegetation of temperate or tropical forests, communication processes are constrained by propagation-induced modifications of the transmitted sounds. The presence of leaves, trunks and branches induces important sound reverberation and absorption leading to diminution of the signal energy as well as qualitative modifications. The aim of this paper is to briefly review the different strategies used by birds to manage with these constraints. At the emitter's level, an adapted emission behavior which takes into account both the physical heterogeneities of the forest environment and the temporal variations of the acoustic constraints, is especially useful to control the active space of signaling. The coding of information into acoustic parameters that have different susceptibility to propagation constraints is also of great interest. At the receiver's level, an adaptive reception behavior (listening post) and a great tolerance to sound degradation during the decoding process are the keys to an optimal communication process.     

Strategies that facilitate or counter eavesdropping on vocal interactions in songbirds

Most territorial songbirds live in communication networks where eavesdropping on vocal interactions may constitute an important option for gathering information regarding the relative dominance, condition and quality of individuals being eavesdropped upon. The relatively low costs and risks of eavesdropping, together with the obvious advantages of gaining such comparative information about other individuals, predict eavesdropping to be a widespread phenomenon even though it is not necessarily advantageous for the participants to be eavesdropped upon. Special eavesdropper strategies that facilitate eavesdropping (how best to eavesdrop) may therefore have evolved together with strategies for interacting that either co-facilitate (public signaling) or counter eavesdropping directly (private signaling) or indirectly by preventing any subsequent negative consequences of being eavesdropped upon (anonymity). This paper reviews the predictions for the strategies and also gives examples supporting their use by territorial songbirds in connection with vocal interactions.     

Variation in NCB5OR: studies of relationships to type 2 diabetes, maturity-onset diabetes of the young, and gestational diabetes mellitus

Recent data show that homozygous Ncb5or(-/-) knock-out mice present with an early-onset nonautoimmune diabetes phenotype. Furthermore, genome-wide scans have reported linkage to the chromosome 6q14.2 region close to the human NCB5OR. We therefore considered NCB5OR to be a biological and positional candidate gene and examined the coding region of NCB5OR in 120 type 2 diabetic patients and 63 patients with maturity-onset diabetes of the young using denaturing high-performance liquid chromatography. We identified a total of 22 novel nucleotide variants. Three variants [IVS5+7del(CT), Gln187Arg, and His223Arg] were genotyped in a case-control design comprising 1,246 subjects (717 type 2 diabetic patients and 529 subjects with normal glucose tolerance). In addition, four rare variants were investigated for cosegregation with diabetes in multiplex type 2 diabetic families. The IVS5+7del(CT) variant was associated with common late-onset type 2 diabetes; however, we failed to relate this variant to any diabetes-related quantitative traits among the 529 control subjects. Thus, variation in the coding region of NCB5OR is not a major contributor in the pathogenesis of nonautoimmune diabetes.     

A Danish diabetes risk score for targeted screening: the Inter99 study

OBJECTIVE: To develop a simple self-administered questionnaire identifying individuals with undiagnosed diabetes with a sensitivity of 75% and minimizing the high-risk group needing subsequent testing. RESEARCH DESIGN AND METHODS: A population-based sample (Inter99 study) of 6,784 individuals aged 30-60 years completed a questionnaire on diabetes-related symptoms and risk factors. The participants underwent an oral glucose tolerance test. The risk score was derived from the first half and validated on the second half of the study population. External validation was performed based on the Danish Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care (ADDITION) pilot study. The risk score was developed by stepwise backward multiple logistic regression. RESULTS: The final risk score included age, sex, BMI, known hypertension, physical activity at leisure time, and family history of diabetes, items independently and significantly (P<0.05) associated with the presence of previously undiagnosed diabetes. The area under the receiver operating curve was 0.804 (95% CI 0.765-0.838) for the first half of the Inter99 population, 0.761 (0.720-0.803) for the second half of the Inter99 population, and 0.803 (0.721-0.876) for the ADDITION pilot study. The sensitivity, specificity, and percentage that needed subsequent testing were 76, 72, and 29%, respectively. The false-negative individuals in the risk score had a lower absolute risk of ischemic heart disease compared with the true-positive individuals (11.3 vs. 20.4%; P<0.0001). CONCLUSIONS: We developed a questionnaire to be used in a stepwise screening strategy for type 2 diabetes, decreasing the numbers of subsequent tests and thereby possibly minimizing the economical and personal costs of the screening strategy.