Effects of Short-Term Fasting on mRNA Expression of Ghrelin and the Peptide Transporters PepT1 and 2 in Atlantic Salmon (Salmo salar)

Food intake is a vital process that supplies necessary energy and essential nutrients to the body. Information regarding luminal composition in the gastrointestinal tract (GIT) collected through mechanical and nutrient sensing mechanisms are generally conveyed, in both mammals and fish, to the hypothalamic neurocircuits. In this context, ghrelin, the only known hormone with an orexigenic action, and the intestinal peptide transporters 1 and 2, involved in absorption of dietary di- and tripeptides, exert important and also integrated roles for the nutrient uptake. Together, both are potentially involved in signaling pathways that control food intake originating from different segments of the GIT. However, little is known about the role of different paralogs and their response to fasting. Therefore, after 3 weeks of acclimatization, 12 Atlantic salmon (Salmo salar) post-smolt were fasted for 4 days to explore the gastrointestinal response in comparison with fed control (n = 12). The analysis covered morphometric (weight, length, condition factor, and wet content/weight fish %), molecular (gene expression variations), and correlation analyses. Such short-term fasting is a common and recommended practice used prior to any handling in commercial culture of the species. There were no statistical differences in length and weight but a significant lower condition factor in the fasted group. Transcriptional analysis along the gastrointestinal segments revealed a tendency of downregulation for both paralogous genes slc15a1a and slc15a1b and with significant lowered levels in the pyloric ceca for slc15a1a and in the pyloric ceca and midgut for slc15a1b. No differences were found for slc15a2a and slc15a2b (except a higher expression of the fasted group in the anterior midgut), supporting different roles for slc15 paralogs. This represents the first report on the effects of fasting on slc15a2 expressed in GIT in teleosts. Transcriptional analysis of ghrelin splicing variants (ghrl-1 and ghrl-2) showed no difference between treatments. However, correlation analysis showed that the mRNA expression for all genes (restricted to segment with the highest levels) were affected by the residual luminal content. Overall, the results show minimal effects of 4 days of induced fasting in Atlantic salmon, suggesting that more time is needed to initiate a large GIT response

Intestinal microbiota development and gestational age in preterm neonates

The intestinal microbiota is an important contributor to the health of preterm infants, and may be destabilized by a number of environmental factors and treatment modalities. How to promote the development of a healthy microbiota in preterm infants is largely unknown. We collected fecal samples from 45 breastfed preterm very low birth weight (birth weight <1500 g) infants from birth until 60 days postnatal age to characterize the intestinal microbiota development during the first weeks of life in preterm infants. Fecal microbiota composition was determined by 16S rRNA amplicon sequencing. The main driver of microbiota development was gestational age; antibiotic use had strong but temporary effects and birth mode had little influence. Microbiota development proceeded in four phases indicated by the dominance of Staphylococcus, Enterococcus, Enterobacter, and finally Bifidobacterium. The Enterococcus phase was only observed among the extremely premature infants and appeared to delay the microbiota succession. The results indicate that hospitalized preterm infants receiving breast milk may develop a normal microbiota resembling that of term infants.Peer reviewe

Enhanced nutrient supply and intestinal microbiota development in very low birth weight infants

BACKGROUND: Promoting a healthy intestinal microbiota may have positive effects on short- and long-term outcomes in very low birth weight (VLBW; BW = 28 weeks) infants and a steeper decrease in relative Staphylococcus abundance in extremely preterm (EP, gestational age <28 weeks) infants as compared to controls. Relative Bifidobacterium abundance tended to increase more in MVP controls compared to the intervention group. Abundance of pathogens was not increased in the intervention group. Higher relative Bifidobacterium abundance was associated with improved weight gain. CONCLUSION: Nutrition may affect richness, diversity, and microbiota composition. There was no increase in relative abundance of pathogens among infants receiving enhanced nutrient supply. Favorable microbiota development was associated with improved weight gain.Peer reviewe

LKR/SDH Plays Important Roles throughout the Tick Life Cycle Including a Long Starvation Period

BACKGROUND:Lysine-ketoglutarate reductase/saccharopine dehydrogenase (LKR/SDH) is a bifunctional enzyme catalyzing the first two steps of lysine catabolism in plants and mammals. However, to date, the properties of the lysine degradation pathway and biological functions of LKR/SDH have been very little described in arthropods such as ticks. METHODOLOGY/PRINCIPAL FINDINGS:We isolated and characterized the gene encoding lysine-ketoglutarate reductase (LKR, EC 1.5.1.8) and saccharopine dehydrogenase (SDH, EC 1.5.1.9) from a tick, Haemaphysalis longicornis, cDNA library that encodes a bifunctional polypeptide bearing domains similar to the plant and mammalian LKR/SDH enzymes. Expression of LKR/SDH was detected in all developmental stages, indicating an important role throughout the tick life cycle, including a long period of starvation after detachment from the host. The LKR/SDH mRNA transcripts were more abundant in unfed and starved ticks than in fed and engorged ticks, suggesting that tick LKR/SDH are important for the starved tick. Gene silencing of LKR/SDH by RNAi indicated that the tick LKR/SDH plays an integral role in the osmotic regulation of water balance and development of eggs in ovary of engorged females. CONCLUSIONS/SIGNIFICANCE:Transcription analysis and gene silencing of LKR/SDH indicated that tick LKR/SDH enzyme plays not only important roles in egg production, reproduction and development of the tick, but also in carbon, nitrogen and water balance, crucial physiological processes for the survival of ticks. This is the first report on the role of LKR/SDH in osmotic regulation in animals including vertebrate and arthropods

The effect of whole-body vibration on jump height and active range of movement in female dancers.

This is an accepted manuscript of an article published by National Strength and Conditioning Association in Journal of strength and conditioning research on 03/2012, available online: https://journals.lww.com/nsca-jscr/Fulltext/2012/03000/The_Effect_of_Whole_Body_Vibration_on_Jump_Height.27.aspx The accepted version of the publication may differ from the final published version.Whole-body vibration (WBV) has been shown to have beneficial effects on strength and power indices in sedentary and moderately trained individuals. The aim of this study was to investigate the effect of 4 weeks of WBV on jump height, active range of motion (AROM), and leg anthropometry in conservatoire dance students. Seventeen female dancers were randomly assigned to a control or intervention group. The intervention group trained for 30 seconds per position at a 35-Hz frequency, 8-mm displacement in the first 2 weeks, and 40 seconds at 40 Hz for the final 2 weeks, whereas the control group carried out the same exercises but without vibration stimulation. A significant (p < 0.01) difference in the intervention group was noted over time for vertical jump and active ROM. No significant changes over time were noted in the anthropometric data. In conclusion, WBV can be used as a beneficial supplemental training intervention to increase jump and active flexibility in highly trained dancers without corresponding increases in relative anthropometric data