Effects of short-term chemical ablation of the GIP receptor on insulin secretion, islet morphology and glucose homeostasis in mice

Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone secreted by endocrine K-cells in response to nutrient absorption. In this study we have utilized a specific and enzymatically stable GIP receptor antagonist, (Pro3)GIP, to evaluate the contribution of endogenous GIP to insulin secretion and glucose homeostasis in mice. Daily injection of (Pro3)GIP (25 nmol/kg body weight) for 11 days had no effect on food intake or body weight. Non-fasting plasma glucose concentrations were significantly raised (p<0.05) by day 11, while plasma insulin concentrations were not significantly different from saline treated controls. After 11 days, intraperitoneal glucose tolerance was significantly impaired in the (Pro3)GIP treated mice compared to control (p<0.01). Glucose-mediated insulin secretion was not significantly different between the two groups. Insulin sensitivity of 11-day (Pro3)GIP treated mice was slightly impaired 60 min post injection compared with controls. Following a 15 min refeeding period in 18 h fasted mice, food intake was not significantly different in (Pro3)GIP treated mice and controls. However, (Pro3)GIP treated mice displayed significantly elevated plasma glucose levels 30 and 60 min post feeding (p<0.05, in both cases). Postprandial insulin secretion was not significantly different and no changes in pancreatic insulin content or islet morphology were observed in (Pro3)GIP treated mice. The observed biological effects of (Pro3)GIP were reversed following cessation of treatment for 9 days. These data indicate that ablation of GIP signaling causes a readily reversible glucose intolerance without appreciable change of insulin secretion.     

Characterization of the maize xylem sap proteome

The xylem in plants has mainly been described as a conduit for water and minerals, but emerging evidence also indicates that the xylem contains protein. To study the proteins in xylem sap, we characterized the identity and composition of the maize xylem sap proteome. The composition of the xylem sap proteome in maize revealed proteins related to different phases of xylem differentiation including cell wall metabolism, secondary cell wall synthesis, and programmed cell death. Many proteins were found to be present as multiple isoforms and some of these isoforms are glycosylated. Proteins involved in defense mechanisms were also present in xylem sap and the sap proteins were shown to have antifungal activity in bioassays.     

The Biphasic Effects of Moderate Alcohol Consumption with a Meal on Ambiance-Induced Mood and Autonomic Nervous System Balance: A Randomized Crossover Trial

Background

The pre-drinking mood state has been indicated to be an important factor in the mood effects of alcohol. However, for moderate alcohol consumption there are no controlled studies showing this association. Also, the mood effects of consuming alcohol combined with food are largely unknown. The aim of this study was to investigate the effects of moderate alcohol combined with a meal on ambiance-induced mood states. Furthermore effects on autonomic nervous system activity were measured to explore physiological mechanisms that may be involved in changes of mood state.

Methods

In a crossover design 28 women (age 18–45 y, BMI 18.5–27 kg/m²) were randomly allocated to 4 conditions in which they received 3 glasses of sparkling white wine (30 g alcohol) or alcohol-free sparkling white wine while having dinner in a room with either a pleasant or unpleasant created ambiance. Subjects filled out questionnaires (B-BAES, POMS and postprandial wellness questionnaire) at different times. Skin conductance and heart rate variability were measured continuously.

Results

Moderate alcohol consumption increased happiness scores in the unpleasant, but not in the pleasant ambiance. Alcohol consumption increased happiness and stimulation feelings within 1 hour and increased sedative feelings and sleepiness for 2.5 hour. Skin conductance was increased after alcohol within 1 hour and was related to happiness and stimulation scores. Heart rate variability was decreased after alcohol for 2 hours and was related to mental alertness.

Conclusion

Mood inductions and autonomic nervous system parameters may be useful to evaluate mood changes by nutritional interventions. Moderate alcohol consumption elevates happiness scores in an unpleasant ambiance. However, drinking alcohol during a pleasant mood results in an equally positive mood state.

Trial Registration

Clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01426022","term_id":"NCT01426022"}}NCT01426022.     

Free radicals in alcoholic myopathy: indices of damage and preventive studies

Chronic alcoholic myopathy affects up to two-thirds of all alcohol misusers and is characterized by selective atrophy of Type II (glycolytic, fast-twitch, anaerobic) fibers. In contrast, the Type I fibers (oxidative, slow-twitch, aerobic) are relatively protected. Alcohol increases the concentration of cholesterol hydroperoxides and malondialdehyde-protein adducts, though protein-carbonyl concentration levels do not appear to be overtly increased and may actually decrease in some studies. In alcoholics, plasma concentrations of alpha-tocopherol may be reduced in myopathic patients. However, alpha-tocopherol supplementation has failed to prevent either the loss of skeletal muscle protein or the reductions in protein synthesis in alcohol-dosed animals. The evidence for increased oxidative stress in alcohol-exposed skeletal muscle is thus inconsistent. Further work into the role of ROS in alcoholic myopathy is clearly warranted.     

Multiple nucleosome positioning sites regulate the CTCF-mediated insulator function of the H19 imprinting control region

The 5' region of the H19 gene harbors a methylation-sensitive chromatin insulator within an imprinting control region (ICR). Insertional mutagenesis in combination with episomal assays identified nucleosome positioning sequences (NPSs) that set the stage for the remarkably precise distribution of the four target sites for the chromatin insulator protein CTCF to nucleosome linker sequences in the H19 ICR. Changing positions of the NPSs resulted in loss of both CTCF target site occupancy and insulator function, suggesting that the NPSs optimize the fidelity of the insulator function. We propose that the NPSs ensure the fidelity of the repressed status of the maternal Igf2 allele during development by constitutively maintaining availability of the CTCF target sites.     

A new insertion sequence element,ISLdl1, in Lactobacillus delbrueckii subsp. lactis ATCC 15808

A new insertion sequence element designated ISLdl1 has been isolated and characterized from Lactobacillus delbrueckii subsp. lactis ATCC 15808. It is the first IS element of L. delbrueckii subsp. lactis described. ISLdl1 is a 1508 bp element flanked by 26 bp imperfect inverted repeats, and generates an 8 bp AT-rich target duplication upon insertion. It contains one ORF encoding a protein of 455 amino acids. This protein shows significant homology to the transposases of the ISL3 family and to other bacterial transposases and putative transposases, and no homology to other proteins. Based on these structural features, ISLdl1 belongs to the ISL3 family. ISLdl1 is present in about 10-12 copies in the genome of ATCC 15808 based on Southern hybridization analysis. Location sites of eight ISLdl1 copies have been determined in more detail by cloning and sequencing one or both of the flanking regions of each ISLdl1 copy. ISLdl1 or ISLdl1-like IS elements were found exclusively in Lactobacillus delbrueckii species and in all strains of subsp. lactis tested. The nucleotide sequence of ISLdl1 is deposited under the accession number AJ302652.     

A visual display board used for efficient breeding and utilization of an athymic (nude) mouse colony.

A visual display board was designed to aid in the management of a barrier sustained athymic (nude) mouse colony. The board displayed pertinent information for breeding and weaning, including phenotype and age for each animal in the colony. In addition, the board showed the availability and current status of experimental groups. This system provided an efficient means of organizing production and planning utilization of animals in the colony.     

Comparison of donor-site healing under Xeroform and Jelonet dressings: unexpected findings

Split-thickness skin grafts remain central to the strategy of burn wound treatment. The dressing used to cover the donor wound site has a significant effect on healing parameters. The purpose of this study was to compare split-thickness skin graft donor site reepithelialization under Xeroform and Jelonet dressings. A dermatome was used to cut two consecutive strips of skin from 25 paired donor sites on the thigh, calf, or back of 19 participants. Standardization of the harvest method was achieved by using the same surgeon to harvest the compared skin graft strips, with attention to consistency of dermatome skin-thickness setting, downward pressure, and angle of dermatome approach. A strip of Xeroform or Jelonet was applied to one of each pair of wounds. Epidermal and dermal thickness was measured from biopsy specimens cut at the midpoint of each split-thickness graft strip. The day of final dressing separation was declared the day of complete donor reepithelialization (healing). The mean healing time for Xeroform and Jelonet was 10.4 +/- 2.6 days (n = 25) and 10.6 +/- 2.8 days (n = 25) (p = 0.76) at sites cut to a mean depth of 0.23 +/- 0.08 mm and 0.23 +/- 0.09 mm (p = 0.89), respectively. There was no correlation between graft thickness and healing time for sites dressed with Xeroform (r = 0.17) or Jelonet (r = 0.02). Donors sites reharvested 10 to 21 days after a prior harvest healed an average of 3.1 days earlier than virgin sites (8.4 +/- 1.6 versus 11.5 +/- 2.6 days, p < 0.001), although reharvested grafts were on average 0.05 mm thicker (p = 0.10). The mean thickness of reepithelialized donor-site epidermis (0.13 +/- 0.04 mm, n = 30) was found to be twice the thickness of virgin epidermis from the same sites (0.06 +/- 0.02 mm, n = 38, p < 0.001). Thirty-six grafts harvested with dermatomes set to cut 8/1000 inch (0.20 mm) deep ranged from 0.12 to 0.42 mm thick, with only eight of these grafts measuring within +/-10 percent of the desired thickness setting. Before donor dressing separation, Xeroform and Jelonet dressings were judged to be more comfortable by nine patients and one patient, respectively, whereas no difference was detected by six patients. The authors now use Xeroform as the preferred donor dressing.     

Glycerol binding at the narrow channel of photosystem II stabilizes the low-spin S2 state of the oxygen-evolving complex

Photosynthesis Research - The oxygen-evolving complex (OEC) of photosystem II (PSII) cycles through redox intermediate states Si (i?=?0–4) during the photochemical oxidation of...