Effect of a synbiotic yogurt on levels of fecal bifidobacteria, clostridia, and enterobacteria

While ingestion of synbiotic yogurts containing Bifidobacterium animalis subsp. lactis and inulin is increasing, their effect on certain microbial groups in the human intestine is unclear. To further investigate this, a large-scale, crossover-design, placebo-controlled study was utilized to evaluate the effect of a synbiotic yogurt containing B. animalis subsp. lactis Bb-12 and inulin on the human intestinal bifidobacteria, clostridia, and enterobacteria. Fecal samples were collected at 14 time points from 46 volunteers who completed the study, and changes in the intestinal bacterial levels were monitored using real-time PCR. Strain Bb-12 could not be detected in feces after 2 weeks of washout. A live/dead PCR procedure indicated that the Bb-12 strain detected in the fecal samples was alive. A significant increase (P < 0.001) in the total bifidobacterial numbers was seen in both groups of subjects during the final washout period compared to the prefeeding period. This increase in total bifidobacteria corresponded with a significant decrease (P < 0.05) in numbers of clostridia but not enterobacteria. No significant differences in numbers of bifidobacteria, clostridia, or enterobacteria were observed between the probiotic and placebo groups during any of the feeding periods. However, subgrouping subjects based on lower initial bifidobacterial numbers or higher initial clostridial numbers did show corresponding significant differences between the synbiotic yogurt and placebo groups. This was not observed for a subgroup with higher initial enterobacterial numbers. While this synbiotic yogurt can increase bifidobacterial numbers and decrease clostridial numbers (but not enterobacterial numbers) in some individuals, it cannot modulate these microbial groups in the majority of individuals.     

Citizen Science as a New Tool in Dog Cognition Research

Family dogs and dog owners offer a potentially powerful way to conduct citizen science to answer questions about animal behavior that are difficult to answer with more conventional approaches. Here we evaluate the quality of the first data on dog cognition collected by citizen scientists using the Dognition.com website. We conducted analyses to understand if data generated by over 500 citizen scientists replicates internally and in comparison to previously published findings. Half of participants participated for free while the other half paid for access. The website provided each participant a temperament questionnaire and instructions on how to conduct a series of ten cognitive tests. Participation required internet access, a dog and some common household items. Participants could record their responses on any PC, tablet or smartphone from anywhere in the world and data were retained on servers. Results from citizen scientists and their dogs replicated a number of previously described phenomena from conventional lab-based research. There was little evidence that citizen scientists manipulated their results. To illustrate the potential uses of relatively large samples of citizen science data, we then used factor analysis to examine individual differences across the cognitive tasks. The data were best explained by multiple factors in support of the hypothesis that nonhumans, including dogs, can evolve multiple cognitive domains that vary independently. This analysis suggests that in the future, citizen scientists will generate useful datasets that test hypotheses and answer questions as a complement to conventional laboratory techniques used to study dog psychology.     

Improved Inflammatory Balance of Human Skeletal Muscle during Exercise after Supplementations of the Ginseng-Based Steroid Rg1

The purpose of the study was to determine the effect of ginseng-based steroid Rg1 on TNF-alpha and IL-10 gene expression in human skeletal muscle against exercise challenge, as well as on its ergogenic outcomes. Randomized double-blind placebo-controlled crossover trials were performed, separated by a 4-week washout. Healthy young men were randomized into two groups and received capsule containing either 5 mg of Rg1 or Placebo one night and one hour before exercise. Muscle biopsies were conducted at baseline, immediately and 3 h after a standardized 60-min cycle ergometer exercise. While treatment differences in glycogen depletion rate of biopsied quadriceps muscle during exercise did not reach statistical significance, Rg1 supplementations enhanced post-exercise glycogen replenishment and increased citrate synthase activity in the skeletal muscle 3 h after exercise, concurrent with improved meal tolerance during recovery (P<0.05). Rg1 suppressed the exercise-induced increases in thiobarbituric acids reactive substance (TBARS) and reversed the increased TNF-alpha and decreased IL-10 mRNA of quadriceps muscle against the exercise challenge. PGC-1 alpha and GLUT4 mRNAs of exercised muscle were not affected by Rg1. Maximal aerobic capacity (VO_2max) was not changed by Rg1. However, cycling time to exhaustion at 80% VO_2max increased significantly by ~20% (P<0.05). Conclusion: Our result suggests that Rg1 is an ergogenic component of ginseng, which can minimize unwanted lipid peroxidation of exercised human skeletal muscle, and attenuate pro-inflammatory shift under exercise challenge.     

A photostable monomeric superfolder green fluorescent protein

The green fluorescent protein (GFP) from Aequorea victoria has been engineered extensively in the past to generate variants suitable for protein tagging. Early efforts produced the enhanced variant EGFP and its monomeric derivative mEGFP, which have useful photophysical properties, as well as superfolder GFP, which folds efficiently under adverse conditions. We previously generated msGFP, a monomeric superfolder derivative of EGFP. Unfortunately, compared to EGFP, msGFP and other superfolder GFP variants show faster photobleaching. We now describe msGFP2, which retains monomeric superfolder properties while being as photostable as EGFP. msGFP2 contains modified N‐ and C‐terminal peptides that are expected to reduce nonspecific interactions. Compared to EGFP and mEGFP, msGFP2 is less prone to disturbing the functions of certain partner proteins. For general‐purpose protein tagging, msGFP2 may be the best available derivative of A. victoria GFP.     

Myosin light-chain expression during avian muscle development

Monoclonal antibodies to adult chicken myosin light chains were generated and used to quantitate the types of myosin light-chain (MLC) isoforms expressed during development of the pectoralis major (PM), anterior latissimus dorsi (ALD), and medial adductor (MA) muscles of the chicken. These are muscles which, in the adult, are composed predominantly of fast, slow, and a mixture of fiber types, respectively. Three distinct phases of MLC expression characterized the development of the PM and MA muscles. The first identifiable pase occurred during the period of 5-7 d of incubation in ovo. Extracts of muscles from the pectoral region (which included the presumptive PM muscle) contained only fast MLC isoforms. This period of exclusive fast light-chain synthesis was followed by a phase (8- 12 d of incubation in ovo) in which coexpression of both fast and slow MLC isoforms was apparent in both PM and MA muscles. During the period, the composition of both fast and slow MLC isoforms in the PM and MA muscles was identical. Beginning at day 12 in ovo, the ALD was also subjected to immunochemical analyses. The proportion of fast and slow MLCs in this muscle at day 12 was similar to that present in the other muscles studied. The third development phase of MLC expression began at approximately 12 d of incubation in ovo and encompassed the transition in MLC composition to the isoform patterns incubation in ovo and encompassed the transition in MLC composition to the isoform patterns typical of adult muscle. During this period, the relative proportion of slow MLC rose in both the MA and ALD and fell in the PM. By day 16, the third fast light chain, LC(3f), was apparent in extracts of both the PM and MA. These results show that there is a developmental progression in the expression of MLC in the two avian muscles studied from day 5 in ovo; first, only fast MLCs are accumulated, then both fast and slow MLC isoforms are expressed. Only during the latter third of development in ovo is the final MLC isoform pattern characteristic of a particular muscle type expressed.     

Inactivation of Retinoblastoma Protein (Rb1) in the Oocyte: Evidence That Dysregulated Follicle Growth Drives Ovarian Teratoma Formation in Mice

The origin of most ovarian tumors is undefined. Here, we report development of a novel mouse model in which conditional inactivation of the tumor suppressor gene Rb1 in oocytes leads to the formation of ovarian teratomas (OTs). While parthenogenetically activated ooctyes are a known source of OT in some mutant mouse models, enhanced parthenogenetic propensity in vitro was not observed for Rb1-deficient oocytes. Further analyses revealed that follicle recruitment and growth is disrupted in ovaries of mice with conditional inactivation of Rb1, leading to abnormal accumulation of secondary/preantral follicles. These findings underpin the concept that miscues between the germ cell and somatic compartments cause premature oocyte activation and the formation of OTs. Furthermore, these results suggest that defects in folliculogenesis and a permissive genetic background are sufficient to drive OT development, even in the absence of enhanced parthenogenetic activation. Thus, we have discovered a novel role of Rb1 in regulating the entry of primordial oocytes into the pool of growing follicles and signaling between the oocyte and granulosa cells during the protracted process of oocyte growth. Our findings, coupled with data from studies of other OT models, suggest that defects in the coordinated regulation between growth of the oocyte and somatic components in follicles are an underlying cause of OT formation.     

An amino acid mixture is essential to optimize insulin-stimulated glucose uptake and GLUT4 translocation in perfused rodent hindlimb muscle

The purpose of this study was to investigate whether an amino acid mixture increases glucose uptake across perfused rodent hindlimb muscle in the presence and absence of a submaximal insulin concentration, and if the increase in glucose uptake is related to an increase in GLUT4 plasma membrane density. Sprague-Dawley rats were separated into one of four treatment groups: basal, amino acid mixture, submaximal insulin, or amino acid mixture with submaximal insulin. Glucose uptake was greater for both insulin-stimulated treatments compared with the non-insulin-stimulated treatment groups but amino acids only increased glucose uptake in the presence of insulin. Phosphatidylinositol 3-kinase (PI 3-kinase) activity was greater for both insulin-stimulated treatments with amino acids having no additional impact. Akt substrate of 160 kDa (AS160) phosphorylation, however, was increased by the amino acids in the presence of insulin, but not in the absence of insulin. AMPK was unaffected by insulin or amino acids. Plasma membrane GLUT4 protein concentration was greater in the rats treated with insulin compared with no insulin in the perfusate. In the presence of insulin, amino acids increased GLUT4 density in the plasma membrane but had no effect in the absence of insulin. AS160 phosphorylation and plasma membrane GLUT4 density accounted for 76% of the variability in muscle glucose uptake. Collectively, these findings suggest that the beneficial effects of an amino acid mixture on skeletal muscle glucose uptake, in the presence of a submaximal insulin concentration, are due to an increase in AS160 phosphorylation and plasma membrane-associated GLUT4, but independent of PI 3-kinase and AMPK activation.