A family-based approach to preventing excessive weight gain

Objective: Preventing weight gain in adults and excessive weight gain in children is a high priority. We evaluated the ability of a family‐based program aimed at increasing steps and cereal consumption (for breakfast and snacks) to reduce weight gain in children and adults. Research Methods and Procedures: Families (n = 105) with at least one 8‐ to 12‐year‐old child who was at‐risk‐for‐overweight or overweight (designated as the target child) were recruited for the study. Eighty‐two families were randomly assigned to receive the family‐based intervention and 23 families to the control condition. The 13‐week intervention consisted of specific increases in daily steps (an additional 2000 steps/d) and consumption of 2 servings/d of ready‐to‐eat cereal. Results: The intervention was successful in increasing walking (steps) and cereal consumption. The intervention had positive, significant effects on percentage BMI‐for‐age and percentage body fat for target children and weight, BMI, and percentage body fat for parents. On further analysis, the positive effects of the intervention were seen largely in target girls and moms, rather than in target boys and dads. Discussion: This family‐based weight gain prevention program based on small changes holds promise for reducing excessive weight gain in families and especially in growing overweight children.     

Relative Ability of Orally Administered Lactobacillus murinus To Predominate and Persist in the Porcine Gastrointestinal Tract

Five porcine-derived Lactobacillus or Pediococcus isolates administered to pigs (n = 4), either singly or as a combination at ~10¹⁰ CFU per day varied with respect to intestinal survival and persistence. Two Lactobacillus murinus strains survived best and were excreted at ~10⁷ to 10⁸ CFU/g of feces. In contrast, Pediococcus pentosaceus DPC6006 had the lowest fecal count at ~10⁵ CFU/g and was excreted at a significantly lower level than both L. murinus strains. Fecal L. murinus DPC6003 counts were also significantly higher than both Lactobacillus salivarius DPC6005 and Lactobacillus pentosus DPC6004 (~10⁶ CFU/g). The L. murinus strains persisted for at least 9 days postadministration in both the feces and the cecum. Animals fed a combination of all five strains excreted ~10⁷ CFU of the administered strains/g, with L. murinus predominating, as determined by randomly amplified polymorphic DNA PCR. Postadministration, variation was observed between animals fed the strain combination, but in general, L. murinus DPC6002 and DPC6003 and L. pentosus DPC6004 predominated in the feces and the cecum while P. pentosaceus DPC6006 was detected only in the cecum. Fifteen days after the start of culture administration, mean fecal Enterobacteriaceae counts were significantly lower in some of the treatment groups. In addition, when mean preadministration counts were compared with those obtained after 21 days of culture administration, Enterobacteriaceae counts were reduced by ~87 to 98% in pigs fed L. salivarius DPC6005, P. pentosaceus DPC6006, L. pentosus DPC6004, and the culture mix. In conclusion, the porcine intestinal isolates have potential as probiotic feed additives for pigs, with differences in strain performance highlighting the advantages of using culture combinations.     

The magnesium inhibition and arrested phagosome hypotheses: new perspectives on the evolution and ecology of Symbiodinium symbioses

Zooxanthella symbioses are arguably the most important ecological interaction on coral reefs because they energetically subsidize the entire community, and enhance the calcification process that provides structure for all other organisms. While we have developed a detailed understanding of the diversity among and within the Symbiodinium clades, we currently lack a mechanistic explanation for which factors favoured zooxanthella invasion of the intracellular habitat in heterotrophic hosts, and for what molecular mechanisms permit residence within the cell. We propose two hypotheses that explain important evolutionary and ecological features of zooxanthella symbioses. The magnesium inhibition hypothesis (MIH) states that increases in the Mg/Ca ratio in sea water that occurred over the last 100 million years created a situation where Mg(2+) inhibited Ca(2+) transport to zooxanthellae. The MIH predicts, among other things, that the intracellular niche was invaded as a response to this abiotic stressor. The arrested phagosome hypothesis (APH) states that Symbiodinium spp. mimic host cell endosomal digestive machinery via the symbiosome to appear like digesting prey through perpetual release of zooxanthella-derived compounds. The APH represents a subtle but important distinction from previous hypotheses regarding interactions between symbiont and host at the cellular level. The APH predicts that symbionts tune rates of material release to match expectations of host cellular machinery. An outcome of the APH is that intra-host residence time becomes a vital parameter to consider. Both hypotheses shift control of the symbiosis away from the host, and instead focus attention on the niche requirements of Symbiodinium spp.     

Solution structure of mu-conotoxin PIIIA,a preferential inhibitor of persistent tetrodotoxin-sensitive sodium channels

Mu-conotoxins are peptide inhibitors of voltage-sensitive sodium channels (VSSCs). Synthetic forms of mu-conotoxins PIIIA and PIIIA-(2-22) were found to inhibit tetrodotoxin (TTX)-sensitive VSSC current but had little effect on TTX-resistant VSSC current in sensory ganglion neurons. In rat brain neurons, these peptides preferentially inhibited the persistent over the transient VSSC current. Radioligand binding assays revealed that PIIIA, PIIIA-(2-22), and mu-conotoxins GIIIB discriminated among TTX-sensitive VSSCs in rat brain, that these and GIIIC discriminated among the corresponding VSSCs in human brain, and GIIIA had low affinity for neuronal VSSCs. (1)H NMR studies found that PIIIA adopts two conformations in solution due to cis/trans isomerization at hydroxyproline 8. The major trans conformation results in a three-dimensional structure that is significantly different from the previously identified conformation of mu-conotoxins GIIIA and GIIIB that selectively target TTX-sensitive muscle VSSCs. Comparison of the structures and activity of PIIIA to muscle-selective mu-conotoxins provides an insight into the structural requirements for inhibition of different TTX-sensitive sodium channels by mu-conotoxins.     

Effect of Mating Structure on Variation in Linkage Disequilibrium

Measurement of linkage disequilibrium involves two sampling processes. First, there is the sampling of gametes in the population to form successive generations, and this generates disequilibrium dependent on the effective population size (N_e) and the mating structure. Second, there is sampling of a finite number (n) of individuals to estimate the population disequilibrium.——Two-locus descent measures are used to describe the mating system and are transformed to disequilibrium moments at the final sampling. Approximate eigenvectors for the transition matrix of descent measures are used to obtain formulae for the variance of the observed disequilibria as a function of N_e, mating structure, n, and linkage or recombination parameter.——The variance of disequilibrium is the same for monoecious populations with or without random selfing and for dioecious populations with random pairing for each progeny. With monogamy, the variance is slightly higher, the proportional difference being greater for unlinked loci.     

The content of four immunomodulatory steroids and major androgens in human semen

Seminal fluid fulfils a dual role: it provides optimal conditions for fertilization and protects male germ cells from infections. Besides both major sexual hormones and cortisol it contains a considerable amounts of dehydroepiandrosterone (DHEA), known to counteract the excessive actions of glucocorticoids. From this point of view of importance may be our recent finding of both 7-hydroxy-dehydroepiandrosterone epimers (7-OH-DHEA) in semen, believed to be in some instances the locally active immunoprotective agents. The concentrations of these steroids were of the same range or even higher than in blood. Here further data on 7-OH-DHEA in semen, along with other relevant steroid hormones, are given in 79 samples, either from healthy males or from patients with various sexual disorders. A method has been developed enabling us a simultaneous determination of DHEA, 7-OH-DHEA epimers, testosterone, dihydrotestosterone and cortisol in seminal fluid. It was based on ether extraction, solvent partition and HPLC separation, followed by specific radioimmunoassays in the respective fractions. In addition, the steroids were measured in serum and the concentrations in both fluids were compared. The concentrations of 7-OH-DHEA in seminal fluid varied from 1.8 to 15.7 nmol/l, while those of DHEA were about five times higher.     

Immunomodulatory cytokines in human seminal plasma correlate with immunomodulatory steroids

7alpha-Hydroxy-dehydroepiandrosterone and its 7beta-hydroxyepimer, which act as local immunomodulatory agents, dehydroepiandrosterone, cortisol, and major androgens, together with four cytokines-interleukins 2, 4, 10, and IFN-gamma, reflecting the activity of TH1 or TH2 cells present in semen, were measured in seminal plasma from 35 male donors. Cortisol, dehydroepiandrosterone, its sulfate, 7-hydroxy-dehydroepiandrosterone epimers, testosterone, and estradiol were also measured in their blood serum. Steroids and interleukins in semen as well as serum steroids and seminal interleukins were mutually correlated to find out whether a relationship between immunomodulatory steroids and cytokines influencing the immune environment does exist. A highly significant (P<0.001) positive correlation was found between seminal 7beta-hydroxy-dehydroepiandrosterone and IFN-gamma, while a negative correlation was found between cortisol and IL-10. Highly significant positive correlations were also found between serum 7alpha-hydroxy-dehydroepiandrosterone and seminal IFN-gamma and between serum 7beta-hydroxy-dehydroepiandrosterone and seminal IL-2, while a negative correlation was found between serum dehydroepiandrosterone and seminal IL-10. Different and in some instances, even contradictory findings concerning the influence of dehydroepiandrosterone and cortisol on TH1 and TH2 cytokines were observed in seminal plasma as compared to those found by others in serum. The differences can be ascribed to the different environments of mucosal and systemic immunity. Correlations between the levels of steroids and cytokines in seminal plasma did not always correspond to the correlations between given cytokines and hormones in sera. The results, however, are in agreement with our recent finding of an autonomous production of these steroids in the male reproductive tract.