Minimally invasive wireless motility capsule to study canine gastrointestinal motility and pH.

The aim of this study was to describe the feasibility of using a gastrointestinal tract wireless motility capsule (WMC) that measured intraluminal pressure, pH and transit time through the gastrointestinal tract, in dogs in their home environment. Forty-four adult healthy dogs, eating a standard diet, were prospectively enrolled. The WMC was well tolerated by all dogs and provided data from the different sections of the gastrointestinal tract. Median gastric emptying time was 20h (range, 6.3-119h), demonstrating a large range. The gastric pressure pattern and pH depended on the phase of food consumption. The small bowel transit time was 3.1h (range, 1.6-5.4h) with average contraction pressures of 6.5mmHg (range, 1.1-21.4mmHg) and pH 7.8 (range, 7-8.9). The large bowel transit time was 21h (range, 1-69h) with average contractions pressures of 0.9mmHg (range, 0.3-2.7mmHg) and pH 6.4 (range, 5.3-8.2). There was considerable individual variation in motility patterns and transit times between dogs. No difference was observed between the sexes. No relationships between any transit time, bowel pH or pressure pattern and bodyweights were identified. The WMC likely represents movement of a large non-digestible particle rather than normal ingesta. Due to its large size, the WMC should not be use in smaller dogs. The WMC is a promising minimally invasive tool to assess GIT solid phase transit times, pressures and pH. However, further studies are necessary due to the current limitations observed.

Myeloid translocation genes differentially regulate colorectal cancer programs.

Myeloid translocation genes (MTGs), originally identified as chromosomal translocations in acute myelogenous leukemia, are transcriptional corepressors that regulate hematopoietic stem cell programs. Analysis of The Cancer Genome Atlas (TCGA) database revealed that MTGs were mutated in epithelial malignancy and suggested that loss of function might promote tumorigenesis. Genetic deletion of MTGR1 and MTG16 in the mouse has revealed unexpected and unique roles within the intestinal epithelium. Mtgr1-/- mice have progressive depletion of all intestinal secretory cells, and Mtg16-/- mice have a decrease in goblet cells. Furthermore, both Mtgr1-/- and Mtg16-/- mice have increased intestinal epithelial cell proliferation. We thus hypothesized that loss of MTGR1 or MTG16 would modify Apc1638/+-dependent intestinal tumorigenesis. Mtgr1-/- mice, but not Mtg16-/- mice, had a 10-fold increase in tumor multiplicity. This was associated with more advanced dysplasia, including progression to invasive adenocarcinoma, and augmented intratumoral proliferation. Analysis of chromatin immunoprecipitation sequencing data sets for MTGR1 and MTG16 targets indicated that MTGR1 can regulate Wnt and Notch signaling. In support of this, immunohistochemistry and gene expression analysis revealed that both Wnt and Notch signaling pathways were hyperactive in Mtgr1-/- tumors. Furthermore, in human colorectal cancer (CRC) samples MTGR1 was downregulated at both the transcript and protein level. Overall our data indicates that MTGR1 has a context-dependent effect on intestinal tumorigenesis.

Ajuga turkestanica increases Notch and Wnt signaling in aged skeletal muscle.

BACKGROUND: The declining myogenic potential of aged skeletal muscle is multifactorial. Insufficient satellite cell activity is one factor in this process. Notch and Wnt signaling are involved in various biological processes including orchestrating satellite cell activity within skeletal muscle. These pathways become dysfunctional during the aging process and may contribute to the poor skeletal muscle competency. Phytoecdysteroids are natural adaptogenic compounds with demonstrated benefit on skeletal muscle. AIM: To determine the extent to which a phytoecdysteroid enriched extract from Ajuga turkestanica (ATE) affects Notch and Wnt signaling in aged skeletal muscle. MATERIALS AND METHODS: Male C57BL/6 mice (20 months) were randomly assigned to Control (CT) or ATE treatment groups. Chow was supplemented with either vehicle (CT) or ATE (50 mg/kg/day) for 28 days. Following supplementation, the triceps brachii muscles were harvested and immunohistochemical analyses performed. Components of Notch or Wnt signaling were co-labelled with Pax7, a quiescent satellite cell marker. RESULTS: ATE supplementation significantly increased the percent of active Notch/Pax7+ nuclei (p = 0.005), Hes1/Pax7+ nuclei (p = 0.038), active B-catenin/Pax7+ nuclei (p = 0.011), and Lef1/Pax7+ nuclei (p = 0.022), compared to CT. ATE supplementation did not change the resting satellite cell number. CONCLUSIONS: ATE supplementation in aged mice increases Notch and Wnt signaling in triceps brachii muscle. If Notch and Wnt benefit skeletal muscle, then phytoecdysteroids may provide a protective effect and maintain the integrity of aged skeletal muscle.

North Atlantic Subtropical Gyre: SOFAR Floats Tracked by Moored Listening Stations.

In 1980, SOFAR (sound fixing and ranging) floats were tracked acoustically in the western North Atlantic entirely by means of moored autonomous listening stations. During a 5-month period 17 float trajectories were obtained in the eastern (45 degrees to 65 degrees W) Gulf Stream and subtropical gyre interior at depths of 700 and 2000 meters. These mid-depth trajectories suggest a time-varying Gulf Stream with instances of both a narrow, swift, westward recirculation south of the stream and a northeastward penetration into the Newfoundland Basin. A hundredfold increase of eddy kinetic energy was observed at 2000 meters from the gyre interior (south of 30 degrees N) to the Gulf Stream.