7,966 research outputs found
The influence of shc proteins on the whole body energetic response to calorie restriction initiated in 3-month-old mice.
There is increasing evidence that Shc proteins play a role in energy metabolism, and we have previously reported that knockdown of Shc proteins influences the energetic response to acute (3 days) calorie restriction (CR) in 18-month-old mice. Whether Shc proteins play a role in the metabolic response to CR in younger mice has yet to be elucidated. Hence, we sought to determine the impact of 3 days and longer term (2 months) CR on energy expenditure (EE) and respiratory quotient (RQ) in 3 month-old Shc knockout (ShcKO) and wild-type (WT) mice. ShcKO mice decreased (P < 0.001) EE normalized for body weight (EEBW) by 3 days of CR, while no such change was observed in WT animals. However, both ShcKO and WT mice decreased (P < 0.001) EEBW at 2 months of CR and there were no differences in body weight between the ShcKO and WT mice at either 3 days or 2 months of CR. Consistent with increased fatty acid oxidation, only ShcKO mice maintained decreased (P < 0.001) 24 h RQ through 2 months of CR, suggesting that they were able to maintain increased fatty acid oxidation for a longer period of time than WT mice. These results indicate that Shc proteins may contribute to some of the acute energetic responses to CR
The influence of shc proteins and aging on whole body energy expenditure and substrate utilization in mice.
While it has been proposed that Shc family of adaptor proteins may influence aging by regulating insulin signaling and energy metabolism, the overall impact of Shc proteins on whole body energy metabolism has yet to be elucidated. Thus, the purpose of this study was to determine the influence of Shc proteins and aging on whole body energy metabolism in a mouse model under ambient conditions (22°C) and acute cold exposure (12°C for 24 hours). Using indirect respiration calorimetry, we investigated the impact of Shc proteins and aging on EE and substrate utilization (RQ) in p66 Shc-/- (ShcKO) and wild-type (WT) mice. Calorimetry measurements were completed in 3, 15, and 27 mo mice at 22°C and 12°C. At both temperatures and when analyzed across all age groups, ShcKO mice demonstrated lower 24 h total EE values than that of WT mice when EE data was expressed as either kJ per mouse, or adjusted by body weight or crude organ mass (ORGAN) (P≤0.01 for all). The ShcKO mice also had higher (P<0.05) fed state RQ values than WT animals at 22°C, consistent with an increase in glucose utilization. However, Shc proteins did not influence age-related changes in energy expenditure or RQ. Age had a significant impact on EE at 22°C, regardless of how EE data was expressed (P<0.05), demonstrating a pattern of increase in EE from age 3 to 15 mo, followed by a decrease in EE at 27 mo. These results indicate a decline in whole body EE with advanced age in mice, independent of changes in body weight (BW) or fat free mass (FFM). The results of this study indicate that both Shc proteins and aging should be considered as factors that influence energy expenditure in mice
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Propionibacterium acnes Induces an IL-17 Response in Acne Vulgaris that Is Regulated by Vitamin A and Vitamin D.
Acne vulgaris is the most common skin disorder affecting millions of people worldwide and inflammation resulting from the immune response targeting Propionibacterium acnes has a significant role in its pathogenesis. In this study, we have demonstrated that P. acnes is a potent inducer of T helper 17 (Th17) and Th1, but not Th2 responses in human peripheral blood mononuclear cells (PBMCs). P. acnes stimulated expression of key Th17-related genes, including IL-17A, RORα, RORc, IL-17RA, and IL-17RC, and triggered IL-17 secretion from CD4(+), but not from CD8(+) T cells. Supernatants from P. acnes-stimulated PBMCs were sufficient to promote the differentiation of naive CD4(+)CD45RA T cells into Th17 cells. Furthermore, we found that the combination of IL-1β, IL-6, and transforming growth factor-β-neutralizing antibodies completely inhibited P. acnes-induced IL-17 production. Importantly, we showed that IL-17-expressing cells were present in skin biopsies from acne patients but not from normal donors. Finally, vitamin A (all-trans retinoic acid) and vitamin D (1,25-dihydroxyvitamin D3) inhibited P. acnes-induced Th17 differentiation. Together, our data demonstrate that IL-17 is induced by P. acnes and expressed in acne lesions and that both vitamin A and D could be effective tools to modulate Th17-mediated diseases such as acne
Premature Ovarian Insufficiency: Procreative Management and Preventive Strategies
Premature ovarian insufficiency (POI) is the loss of normal hormonal and reproductive function of ovaries in women before age 40 as the result of premature depletion of oocytes. The incidence of POI increases with age in reproductive-aged women, and it is highest in women by the age of 40 years. Reproductive function and the ability to have children is a defining factor in quality of life for many women. There are several methods of fertility preservation available to women with POI. Procreative management and preventive strategies for women with or at risk for POI are reviewed
Wallpaper Fermions and the Nonsymmorphic Dirac Insulator
Recent developments in the relationship between bulk topology and surface
crystal symmetry have led to the discovery of materials whose gapless surface
states are protected by crystal symmetries. In fact, there exists only a very
limited set of possible surface crystal symmetries, captured by the 17
"wallpaper groups." We show that a consideration of symmetry-allowed band
degeneracies in the wallpaper groups can be used to understand previous
topological crystalline insulators, as well as to predict new examples. In
particular, the two wallpaper groups with multiple glide lines, and
, allow for a new topological insulating phase, whose surface spectrum
consists of only a single, fourfold-degenerate, true Dirac fermion. Like the
surface state of a conventional topological insulator, the surface Dirac
fermion in this "nonsymmorphic Dirac insulator" provides a theoretical
exception to a fermion doubling theorem. Unlike the surface state of a
conventional topological insulator, it can be gapped into topologically
distinct surface regions while keeping time-reversal symmetry, allowing for
networks of topological surface quantum spin Hall domain walls. We report the
theoretical discovery of new topological crystalline phases in the AB
family of materials in SG 127, finding that SrPb hosts this new
topological surface Dirac fermion. Furthermore, (100)-strained AuY and
HgSr host related topological surface hourglass fermions. We also
report the presence of this new topological hourglass phase in
BaInSb in SG 55. For orthorhombic space groups with two glides, we
catalog all possible bulk topological phases by a consideration of the allowed
non-abelian Wilson loop connectivities, and we develop topological invariants
for these systems. Finally, we show how in a particular limit, these
crystalline phases reduce to copies of the SSH model.Comment: Final version, 6 pg main text + 29 pg supplement, 6 + 13 figure
An Exploratory Survey of Incivility Experienced by Novice Occupational Therapists Educated Using a Servant Leadership Model
The purpose of this study was to identify the incidence of incivility experienced by a purposive sample of novice occupational therapists who graduated from a master’s level program that focused on developing servant leaders as part of its mission. Data from this group was then compared to outcomes from a previous national survey of novice occupational therapists. Incivility in both studies was measured using the Negative Acts Questionnaire-Revised (NAQ-R). An independent samples t-test showed that NAQ-R total scores and person-related incivility subscores were significantly (
Metformin as a Therapeutic Target in Endometrial Cancers.
Endometrial cancer is the most common gynecologic malignancy in developed countries. Its increasing incidence is thought to be related in part to the rise of metabolic syndrome, which has been shown to be a risk factor for the development of hyperestrogenic and hyperinsulinemic states. This has consequently lead to an increase in other hormone-responsive cancers as well e.g., breast and ovarian cancer. The correlation between obesity, hyperglycemia, and endometrial cancer has highlighted the important role of metabolism in cancer establishment and persistence. Tumor-mediated reprogramming of the microenvironment and macroenvironment can range from induction of cytokines and growth factors to stimulation of surrounding stromal cells to produce energy-rich catabolites, fueling the growth, and survival of cancer cells. Such mechanisms raise the prospect of the metabolic microenvironment itself as a viable target for treatment of malignancies. Metformin is a biguanide drug that is a first-line treatment for type 2 diabetes that has beneficial effects on various markers of the metabolic syndrome. Many studies suggest that metformin shows potential as an adjuvant treatment for uterine and other cancers. Here, we review the evidence for metformin as a treatment for cancers of the endometrium. We discuss the available clinical data and the molecular mechanisms by which it may exert its effects, with a focus on how it may alter the tumor microenvironment. The pleiotropic effects of metformin on cellular energy production and usage as well as intercellular and hormone-based interactions make it a promising candidate for reprogramming of the cancer ecosystem. This, along with other treatments aimed at targeting tumor metabolic pathways, may lead to novel treatment strategies for endometrial cancer
Amyloid positron emission tomography candidates may focus more on benefits than risks of results disclosure
IntroductionGiven mounting calls to disclose biomarker test results to research participants, we explored factors underlying decisions by patients with mild cognitive impairment to receive amyloid imaging results.MethodsProspective, qualitative interviews were conducted with 59 participants (30 = mild cognitive impairment patients, 29 = care partners) from the scan arm of a randomized controlled trial on the effects of amyloid PET results disclosure in an Alzheimer Disease Research Center setting.ResultsSixty‐three percent of the participants were female, with an average age of 72.9 years, and most had greater than a high school level of education (80%). Primary motivations included: (1) better understanding one’s mild cognitive impairment etiology and prognosis to plan ahead, and (2) learning one’s brain amyloid status for knowledge’s sake, regardless of whether the information is actionable. Most participants demonstrated an adequate understanding of the scan’s limitations, yet instances of characterizing amyloid PET as a definitive test for Alzheimer’s disease occurred. Mention of potential drawbacks, such as negative psychological outcomes, was minimal, even among care partners.DiscussionFindings demonstrate a risk of disproportionate focus on possible benefits of testing among amyloid scan candidates and suggest a need to clearly emphasize the limitations of amyloid PET when counseling cognitively impaired patients and their families before testing. Future research should examine whether minimizing drawbacks at the pre‐imaging stage has adverse consequences on results disclosure.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152635/1/dad2jdadm201805003.pd
Visitor satisfaction with a key wildlife tourism destination within the context of a damaged landscape
Wildlife tourism is a growing industry globally and visitor satisfaction is vital to ensure its long-term sustainability. The Lower Kinabatangan River is a premier wildlife tourism destination that is affected by surrounding land uses and needs careful management to ensure it continues to provide positive wildlife tourism experiences. As little is known about the motivations and satisfaction of tourists with this experience, a visitor survey was conducted along the Lower Kinabatangan River with 346 surveys completed. The attribute ‘Interest in viewing wildlife’ had the highest mean level of importance and satisfaction (mean = 4.54 and 4.1, respectively, on a 5-point scale). Respondents were very satisfied with their wildlife tour experience (85%) and would recommend the experience to their friends (87%). However, almost half of respondents (47%) felt more needed to be done to protect the Kinabatangan River and wildlife. Although respondents were satisfied overall with their experience, they also expressed concerns over the number of boats and the protection of the River. Comments focused on the presence of rubbish in the River, intrusion of oil palm and the loss of forest. Many issues are beyond the management realms of tour operators but will impact on the future of the industry
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