Long-term high fat feeding of rats results in increased numbers of circulating microvesicles with pro-inflammatory effects on endothelial cells

Obesity and type 2 diabetes lead to dramatically increased risks of atherosclerosis and CHD. Multiple mechanisms converge to promote atherosclerosis by increasing endothelial oxidative stress and up-regulating expression of pro-inflammatory molecules. Microvesicles (MV) are small ( < 1 μm) circulating particles that transport proteins and genetic material, through which they are able to mediate cell–cell communication and influence gene expression. Since MV are increased in plasma of obese, insulin-resistant and diabetic individuals, who often exhibit chronic vascular inflammation, and long-term feeding of a high-fat diet (HFD) to rats is a well-described model of obesity and insulin resistance, we hypothesised that this may be a useful model to study the impact of MV on endothelial inflammation. The number and cellular origin of MV from HFD-fed obese rats were characterised by flow cytometry. Total MV were significantly increased after feeding HFD compared to feeding chow (P< 0·001), with significantly elevated numbers of MV derived from leucocyte, endothelial and platelet compartments (P< 0·01 for each cell type). MV were isolated from plasma and their ability to induce reactive oxygen species (ROS) formation and vascular cell adhesion molecule (VCAM)-1 expression was measured in primary rat cardiac endothelial cells in vitro. MV from HFD-fed rats induced significant ROS (P< 0·001) and VCAM-1 expression (P= 0·0275), indicative of a pro-inflammatory MV phenotype in this model of obesity. These findings confirm that this is a useful model to further study the mechanisms by which diet can influence MV release and subsequent effects on cardio-metabolic health

From Mothering Without a Net to Mothering on the Net: The Impact of an Online Social Networking Site on Experiences of Postpartum Depression

This research speaks to the desire expressed by women, health care professionals, and researchers alike, for an alternative, non-pharmacological or therapy-related intervention for postpartum depression (PPD). Interviews with twenty-two mothers and members of Momstown.ca—a social networking site focused on connecting mothers online and face-to-face—demonstrated new mothers are increasingly isolated and without community. However, mothers reported becoming members of Momstown allowed them to build a social network providing them company, camaraderie, and community, resulting in improved mental health. We conclude services like Momstown could be viable, alternative interventions for women with ppd, enabling mothers to survive and thrive postpartum

Associations of Maternal Carbohydrate Intake During Pregnancy and Adolescent Adiposity and Metabolic Health

Maternal diet during gestation is known to affect offspring phenotypes. The majority of dietary studies in pregnancy look at restriction of protein or exposure to high fat diet. Few concentrate on the critical macronutrient for fetal growth: carbohydrates (CHO). This study analyses both human and animal data for evidence of developmental programming of adiposity and dysmetabolism in adolescent offspring. In 237 mother-child birth pairs in the human ELEMENT birth cohort, mother’s dietary carbohydrate intakes were assessed for association with child adiposity and metabolic health outcomes in peripuberty. Mothers with greater intakes of total and net CHO during pregnancy gave birth to children who had lower adiposity and lower metabolic risk during the peripubertal period. After accounting for maternal age, child age, sex, and pubertal status, children of women in the 4th vs 1st quartile of total CHO intake in the first trimester had a 0.12-unit lower BMIz score (95% CI -0.55, 0.31, p=0.10). Children of mothers in the 4th quartile of total CHO intake also had a 0.07 unit (95% CI 0.28, 0.13, p=0.13) lower metabolic risk z score in peripuberty. Measures of c-peptide followed a similar trend, such that the 4th quartile of total CHO intake in the first trimester was associated with a 0.31-unit lower c-peptide score (95% CI -0.72, 0.11, p=0.05) compared to those whose mothers were in the 1st quartile. These associations were not attributed to delivery method, child’s diet in peripuberty, or nutrient substitution with protein or fat. This was further modeled in animals by exposing pregnant mice to 10% sucrose water or tap water during gestation. Sucrose exposed dams gave birth to offspring who had greater fat mass than dams exposed to water. Female pups of sucrose-exposed dams also had less fat free mass and better insulin tolerance in young adulthood. The mechanism for these effects is yet to be elucidated, but is not attributable to maternal weight during pregnancy, offspring food intakes, or offspring feeding efficiency. Further is necessary to highlight the mechanisms underlying these divergent results to two model systems.Master of SciencePublic HealthUniversity of Michiganhttps://deepblue.lib.umich.edu/bitstream/2027.42/149652/1/Thesis_Final_MCarter.pd

Operating Temperatures of a Sodium-Cooled Exhaust Valve as Measured by a Thermocouple

A thermocouple was installed in the crown of a sodium-cooled exhaust valve. The valve was then tested in an air-cooled engine cylinder and valve temperatures under various engine operating conditions were determined. A temperature of 1337 F was observed at a fuel-air ratio of 0.064, a brake mean effective pressure of 179 pounds per square inch, and an engine speed of 2000 rpm. Fuel-air ratio was found to have a large influence on valve temperature, but cooling-air pressure and variation in spark advance had little effect. An increase in engine power by change of speed or mean effective pressure increased the valve temperature. It was found that the temperature of the rear spark-plug bushing was not a satisfactory indication of the temperature of the exhaust valve