38 research outputs found
Xenoestrogens from Household Plastics Bind Estrogen Receptors and Affect Cell Proliferation
Xenoestrogens are “foreign” chemicals or compounds that interact with estrogen receptors as either agonists or antagonists to interfere with endocrine system function. Xenoestrogens include phytoestrogens, pesticides, industrial by- products and synthetic estrogens. In this study, consumer plasticware, including baby bottles and food storage containers, were found to release xenoestrogenic compounds that bound to ERα and ERβ and affected cell proliferation
Essential Oils from Apple mint (Mentha suaveolens) and Passionflower fruit (Passiflora incarnata): Studies on Cognition, Coordination, and Chemical Components.
Plant essential oils (EO) are used as perfumes, lotions and air fresheners because of their pleasant aromas, but EO also have the ability to elicit changes in mood and behavior. These activities are influenced by the mode of administration and by multiple signaling pathways. The EO aromas from organically grown apple mint (Mentha suaveolens) and passionflower fruit (Passiflora incarnata) were assessed for their effects on cognition and coordination. Participants completed two tasks designed to test working memory and bimanual task efficiency in rooms infused with apple mint, passionflower fruit or control EO. Bimanual coordination was assessed using the Intercept2 program and the Memory Span component of CogLab 2.0 was utilized as a test of working memory. Then, the EO were analyzed by GC-MS, resulting in the identification of several compounds with affinity towards olfactory receptors and neurotransmitter systems. For specific memory subtests within CogLab, EO from apple mint aided number recall, whereas passionflower fruit hindered recall of numbers and letters that sound similar. Passionflower fruit EO slightly enhanced bimanual task coordination. The results indicate that specific aromas may differentially affect task performance
A Synthesis of Tagging Studies Examining the Behaviour and Survival of Anadromous Salmonids in Marine Environments
This paper synthesizes tagging studies to highlight the current state of knowledge concerning the behaviour and survival of anadromous salmonids in the marine environment. Scientific literature was reviewed to quantify the number and type of studies that have investigated behaviour and survival of anadromous forms of Pacific salmon (Oncorhynchus spp.), Atlantic salmon (Salmo salar), brown trout (Salmo trutta), steelhead (Oncorhynchus mykiss), and cutthroat trout (Oncorhynchus clarkii). We examined three categories of tags including electronic (e.g. acoustic, radio, archival), passive (e.g. external marks, Carlin, coded wire, passive integrated transponder [PIT]), and biological (e.g. otolith, genetic, scale, parasites). Based on 207 papers, survival rates and behaviour in marine environments were found to be extremely variable spatially and temporally, with some of the most influential factors being temperature, population, physiological state, and fish size. Salmonids at all life stages were consistently found to swim at an average speed of approximately one body length per second, which likely corresponds with the speed at which transport costs are minimal. We found that there is relatively little research conducted on open-ocean migrating salmonids, and some species (e.g. masu [O. masou] and amago [O. rhodurus]) are underrepresented in the literature. The most common forms of tagging used across life stages were various forms of external tags, coded wire tags, and acoustic tags, however, the majority of studies did not measure tagging/handling effects on the fish, tag loss/failure, or tag detection probabilities when estimating survival. Through the interdisciplinary application of existing and novel technologies, future research examining the behaviour and survival of anadromous salmonids could incorporate important drivers such as oceanography, tagging/handling effects, predation, and physiology
Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures
Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo
Insulin-Like Growth Factors and Male Reproductive Physiology: Effects on Bovine Spermatozoa
Effects of Panax ginseng, zearalenol, and estradiol on sperm function
Background: Estrogen signaling pathways are modulated by exogenous factors. Panax ginseng exerts multiple activities in biological systems and is classified as an adaptogen. Zearalenol is a potent mycoestrogen that may be present in herbs and crops arising from contamination or endophytic association. The goal of this study was to investigate the impact of P. ginseng, zearalenol and estradiol in tests on spermatozoal function.
Methods: The affinity of these compounds for estrogen receptor (ER)—alpha and beta (ERα and ERβ)—was assessed in receptor binding assays. Functional tests on boar spermatozoa motility, movement and kinematic parameters were conducted using a computer-assisted sperm analyzer. Tests for capacitation, acrosome reaction (AR), and chromatin decondensation in spermatozoa were performed using microscopic analysis.
Results: Zearalenol—but not estradiol (E2)- or ginseng-treated spermatozoa—decreased the percentage of overall, progressive, and rapid motile cells. Zearalenol also decreased spontaneous AR and increased chromatin decondensation. Ginseng decreased chromatin decondensation in response to calcium ionophore and decreased AR in response to progesterone (P4) and ionophore.
Conclusion: Zearalenol has adverse effects on sperm motility and function by targeting multiple signaling cascades, including P4, E2, and calcium pathways. Ginseng protects against chromatin damage and thus may be beneficial to reproductive fitness
Identification of kinases, phosphatases, and phosphorylation sites in human and porcine spermatozoa
<div><p></p><p>Multiple inter-connected signaling pathways, involving kinases and phosphatases, form a framework that controls sperm motility, function, and fertilizing ability. Methods that give a broad view of the proteomic landscape may prove valuable in uncovering new crosstalk connections, as well as in discovering new proteins within this regulatory framework. A multi-immunoblotting strategy was utilized to evaluate this concept on human and porcine spermatozoa samples. In human and porcine spermatozoa, a diversity of kinases were identified including protein kinase A (PKA), protein kinase B (PKB), isoforms of protein kinase C (PKC), calmodulin-dependent kinases (CAMK), casein kinase (CK), and isoforms of glycogen synthase kinase (GSK3). Several phosphatases, such as protein phosphatase (PP)-1, PP2A, PP2C, and mitogen activated protein kinase (MAPK) phosphatase (MKP-1), were identified in human spermatozoa. The phosphorylation epitopes recognized belonged to members of the MAPK family, in addition to α and β isoforms of GSK3 and cAMP response element binding protein (CREB). Proteomic approaches that allow a broad view may aid in understanding the crosstalk between signaling systems in spermatozoal physiology.</p></div
Identification of kinases, phosphatases, and phosphorylation sites in human and porcine spermatozoa
Insulin resistance in polycystic ovary syndrome is associated with defective regulation of ERK1/2 by insulin in skeletal muscle in vivo
Insulin resistance is a recognized feature of PCOS (polycystic ovary syndrome). However, the molecular reason(s) underlying this reduced cellular insulin sensitivity is not clear. The present study compares the major insulin signalling pathways in skeletal muscle isolated from PCOS and controls. We measured whole-body insulin sensitivity and insulin signalling in skeletal muscle biopsies taken before and after acute exposure to hyper-insulinaemia in nine women diagnosed with PCOS and seven controls. We examined the expression, basal activity and response to in vivo insulin Stimulation of three signalling molecules within these human Muscle samples, namely IRS-1 (insulin receptor substrate-1), PKB (protein kinase B) and ERK (extracellular-signal-regulated kinase) 1/2. There was no significant difference in the expression, basal activity or activation of IRS-1 or PKB between PCOS and control subjects. However, there was it severe attenuation of insulin stimulation of the ERK pathway in muscle from all but two of the women with PCOS (the two most obese), and,in accompanying trend towards. higher basal phosphorylation of ERK 1/2 in PCOS. These results are striking in that the metabolic actions of insulin are widely believed to require the IRS-1/PKB pathway rather than ERK, and the former has been reported its defective in some previous PCOS Studies. Most importantly, the molecular defect identified was independent of adiposity. The altered response of ERK to insulin in PCOS was the most obvious signalling defect associated with insulin resistance in muscle from these patients