Effects of eugenol on resting tension of rat atria

In cardiac and skeletal muscle, eugenol (μM range) blocks excitation-contraction coupling. In skeletal muscle, however, larger doses of eugenol (mM range) induce calcium release from the sarcoplasmic reticulum. The effects of eugenol are therefore dependent on its concentration. In this study, we evaluated the effects of eugenol on the contractility of isolated, quiescent atrial trabeculae from male Wistar rats (250-300 g; n=131) and measured atrial ATP content. Eugenol (1, 3, 5, 7, and 10 mM) increased resting tension in a dose-dependent manner. Ryanodine [100 µM; a specific ryanodine receptor (RyR) blocker] and procaine (30 mM; a nonspecific RyR blocker) did not block the increased resting tension induced by eugenol regardless of whether extracellular calcium was present. The myosin-specific inhibitor 2,3-butanedione monoxime (BDM), however, reversed the increase in resting tension induced by eugenol. In Triton-skinned atrial trabeculae, in which all membranes were solubilized, eugenol did not change resting tension, maximum force produced, or the force vs pCa relationship (pCa=-log [Ca2+]). Given that eugenol reduced ATP concentration, the increase in resting tension observed in this study may have resulted from cooperative activation of cardiac thin filaments by strongly attached cross-bridges (rigor state).

Effects of bromopride on expression of metalloproteinases and interleukins in left colonic anastomoses: an experimental study

Anastomotic dehiscence is the most severe complication of colorectal surgery. Metalloproteinases (MMPs) and interleukins (ILs) can be used to analyze the healing process of anastomosis. To evaluate the effects of bromopride on MMP and cytokine gene expression in left colonic anastomoses in rats with or without induced abdominal sepsis, 80 rats were divided into two groups for euthanasia on the third or seventh postoperative day (POD). They were then divided into subgroups of 20 rats for sepsis induction or not, and then into subgroups of 10 rats for administration of bromopride or saline. Left colonic anastomosis was performed and abdominal sepsis was induced by cecal ligation and puncture. A colonic segment containing the anastomosis was removed for analysis of gene expression of MMP-1α, MMP-8, MMP-13, IL-β, IL-6, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). On the third POD, bromopride was associated with increased MMP-1α, MMP-13, IL-6, IFN-γ, and IL-10 gene expression. On the seventh POD, all MMP transcripts became negatively modulated and all IL transcripts became positively modulated. In the presence of sepsis, bromopride administration increased MMP-8 and IFN-γ gene expression and decreased MMP-1, TNF-α, IL-6, and IL-10 gene expression on the third POD. On the seventh POD, we observed increased expression of MMP-13 and all cytokines, except for TNF-α. In conclusion, bromopride interferes with MMP and IL gene expression during anastomotic healing. Further studies are needed to correlate these changes with the healing process.

Modulatory effects of taurine on jejunal contractility

Taurine (2-aminoethanesulfonic acid) is widely distributed in animal tissues and has diverse pharmacological effects. However, the role of taurine in modulating smooth muscle contractility is still controversial. We propose that taurine (5-80 mM) can exert bidirectional modulation on the contractility of isolated rat jejunal segments. Different low and high contractile states were induced in isolated jejunal segments of rats to observe the effects of taurine and the associated mechanisms. Taurine induced stimulatory effects on the contractility of isolated rat jejunal segments at 3 different low contractile states, and inhibitory effects at 3 different high contractile states. Bidirectional modulation was not observed in the presence of verapamil or tetrodotoxin, suggesting that taurine-induced bidirectional modulation is Ca2+dependent and requires the presence of the enteric nervous system. The stimulatory effects of taurine on the contractility of isolated jejunal segments was blocked by atropine but not by diphenhydramine or by cimetidine, suggesting that muscarinic-linked activation was involved in the stimulatory effects when isolated jejunal segments were in a low contractile state. The inhibitory effects of taurine on the contractility of isolated jejunal segments were blocked by propranolol and L-NG-nitroarginine but not by phentolamine, suggesting that adrenergic β receptors and a nitric oxide relaxing mechanism were involved when isolated jejunal segments were in high contractile states. No bidirectional effects of taurine on myosin phosphorylation were observed. The contractile states of jejunal segments determine taurine-induced stimulatory or inhibitory effects, which are associated with muscarinic receptors and adrenergic β receptors, and a nitric oxide associated relaxing mechanism.

Effects of propofol on lipopolysaccharide-induced expression and release of HMGB1 in macrophages

This study aimed to determine the effects of different concentrations of propofol (2,6-diisopropylphenol) on lipopolysaccharide (LPS)-induced expression and release of high-mobility group box 1 protein (HMGB1) in mouse macrophages. Mouse macrophage cell line RAW264.7 cells were randomly divided into 5 treatment groups. Expression levels of HMGB1 mRNA were detected using RT-PCR, and cell culture supernatant HMGB1 protein levels were detected using enzyme-linked immunosorbent assay (ELISA). Translocation of HMGB1 from the nucleus to the cytoplasm in macrophages was observed by Western blotting and activity of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in the nucleus was detected using ELISA. HMGB1 mRNA expression levels increased significantly in the cell culture supernatant and in cells after 24 h of stimulating RAW264.7 cells with LPS (500 ng/mL). However, HMGB1 mRNA expression levels in the P2 and P3 groups, which received 500 ng/mL LPS with 25 or 50 μmol/mL propofol, respectively, were significantly lower than those in the group receiving LPS stimulation (P<0.05). After stimulation by LPS, HMGB1 protein levels were reduced significantly in the nucleus but were increased in the cytoplasm (P<0.05). Simultaneously, the activity of NF-κB was enhanced significantly (P<0.05). After propofol intervention, HMGB1 translocation from the nucleus to the cytoplasm and NF-κB activity were inhibited significantly (each P<0.05). Thus, propofol can inhibit the LPS-induced expression and release of HMGB1 by inhibiting HMGB1 translocation and NF-κB activity in RAW264.7 cells, suggesting propofol may be protective in patients with sepsis.

Effects of internationalization on packaging decisions of manufacturing companies

The world has witnessed a great deal of globalization and a rise in international activities in recent years compared to decades ago. This has contributed to an upsurge in competition among manufacturing firms resulting in the use of different marketing strategies to survive. Packaging is one of the tools that has been used by marketers to make products different and appealing to both local and international customers. The purpose of this research work was to investigate more on packaging as a marketing tool and how internationalization affects the decisions management makes in relation to it. To this effect, a qualitative research was conducted using five manufacturing companies as case studies and data collected through semi-structured interviews and also personal observation. Secondary sources were also used in order to get deeper insight into the case companies under study. The study revealed that there are many advantages that internationalization provides firms. The general revelations made by the firms that were researched did not point to a negative impact of internationalization on their packaging decisions. Internationalization has provided positive improvements on their packaging and made them more competitive. This proves that for packaging decisions to improve better, one key enabler will be exposure to the international environment since it provides a wider array of options for package improvements for firms.

Effects of nickel on the mineral composition of Fleischmann’s yeast (Saccharomyces cerevisiae)

Sugar cane juice containing 12% (w.w -1) of total reducing sugars and 0.0 to 5.0 mmol of nickel L-1, with pH ranging from 3.5 to 6.5, was inoculated with Fleischmann’s yeast (Saccharomyces cerevisiae) (10% w.w -1). Six hours after fermentation, the yeast’s cellular viability and trehalose content were evaluated. The resulting must was centrifuged and the raw yeast was analyzed by atomic absorption spectroscopy to evaluate the intracellular levels of calcium, copper, iron, magnesium, manganese, nickel, phosphorus, potassium, sulfur and zinc. The intracellular levels of iron, magnesium and calcium were affected and the yeast’s susceptibility to nickel was enhanced by the decrease in pH. The yeast’s growth was not affected by nickel at high pH, but the toxic effects of nickel were potentiated at low pH.

Effects of processing on physical properties of extruded snacks with blends of sour cassava starch and flaxseed flour

The opportunity to supplement common cassava biscuits with a product of higher nutritional value meets consumer expectations. In this work it was studied the effects of process parameters and flaxseed addition on physical properties of expanded snacks. Extrusion process was carried out using a single screw extruder in a factorial central composite rotatable design with four factors: flaxseed flour percentage (0-20%), moisture (12-20%), extrusion temperature (90-130 °C) and screw speed (190-270). The effect of extrusion variables was investigated in terms of expansion index, specific volume, water absorption index, water solubility index, color parameters (L*, a* ,b*) and hardness. The data analysis showed that variable parameters of the extrusion process and flaxseed flour affected physical properties of puffed snacks. Among the experimental conditions used in the present study, expanded snack products with good physical properties can be obtained under the conditions of 10% flaxseed flour, 230 rpm screw speed, temperature of 90 °C and moisture of 12%.

Moderating effects of gender on the relationships among substance use and school outcomes /

The following study was a secondary analysis of data drawn from adolescents in South Western Ontario. The purpose of the study was to: examine the relationships among substance use and school outcomes, explore the relationships between gender and school outcomes, examine the moderating potential of gender on the substance useschool outcomes relationship, and to provide researchers and educators further knowledge of adolescent substance use behaviours. Many previous studies have failed to include the three most common substances used by adolescents (i.e., alcohol, tobacco, and marijuana). Furthermore, many studies have included only one school outcome instead of comparing several outcome variables. Moderated hierarchical regression was used to determine if gender moderated the substance use-school outcomes relationships. The dependent variables consisted of alcohol use, binge drinking, tobacco use, and marijuana use. Five measure of school outcomes were used as independent variables, including Grade Point Average, Positive School-role Behaviour, Negative School Behaviour, School Withdrawal, and School Misbehaviour. The results for this study indicated that substance use and gender were both predictors of all school outcome variables. Furthermore, gender was found to moderate 5 of the 25 substance use-school outcome relationships.

An investigation into differences between indoleacetic acid and fusicoccin in their influence on RNA synthesis, protein synthesis and growth in Avena coleoptile tissue

Growth stimulation of Avena coleoptile tissue by indoleacetic acid (IAA) and fusicoccin (FC) was compared by measuring both their influence on RNA and protein synthesis during IAA or FC stimulated growth. FC stimulated growth more than IAA during the initial four hour exposure, after which the growth rate gradually declined to the control rate. FC, but not IAA, increased the uptake of 3H-Ieucine into tissue and the specific radioactivity of extracted protein. Cycloheximide inhibited the incorporation of 3H-Ieucine into protein by approximately 60% to 70% in all cases. In the presence of cycloheximide 3H-radioactivity accumulated in FC-treated tissue, whereas IAA did not seem to influence 3H-accumulation. These results suggest that FC stimulated leucine uptake into the tissue and that increased specific activity of coleoptile protein is due to increased leucine uptake, not an increased rate of protein synthesis. There was no measurable influence of IAA and/or FC on RNA and protein synthesis during the initial hours of a growth stimulation. Inhibitors of RNA and protein synthesis, actinomycin D and cycloheximide, respectively, severely inhibited IAA enhanced growth but only partially inhibited FC stimulated growth. The data are consistent with suggestions that a rapidly turning over protein participates in IAA stimulated growth, and that a continual synthesis of RNA and proteins is an absolute requirement for a long term growth response to IAA. On the contrary, FC-stimulated growth exhibited less dependency on the transcription and translation processes. The data are consistent with proposals suggesting different sites of action for FC and IAA stimulated growth. l?hen compared to CO2-free air, CO2 at 300 ppm had no significant influence on coleoptile growth and protein synthesis in the presence or absence of lAA or FC. Also, I mM malate, pH 6.0 did not influence growth of coleoptiles in the presence or absence of lAA. This result was obtained despite reports indicating that 300 ppm CO2 or I mM malate stimulates growth and protein synthesis. This lack of difference between CO2-treated and untreated tissue could indicate either that the interstitial space CO2 concentration is not actually different in the two treatments due to significant endogenous respiratory CO2 or else the data would suggest a very loose coupling between dark CO2 fixation and growth. IAA stimulated the in vivo fixation of 14c-bicarbonate (NaHI4c03) by about 25% and the addition of cycloheximide caused an inhibition of bicarbonate fixation within 30 min. Cycloheximide has also been reported to inhibit IAA-stimulated H+ excretion. These data are consistent with the acid growth theory and suggest that lAA stimulated growth involves dark CO2 fixation. The roles of dark CO2 fixation in lAA-stimulated growth are discussed.

Exploring the effects of change on nursing practice in acute ambulatory care settings : a qualitative study

As a result of the current changes taking place in the delivery of acute care services, the emergence of acute ambulatory care (AAC) settings is expanding. According to a literature review, the volume, acuity, and complexity of patient care in these settings is increasing while the time the patients spend under the care of nurses is decreasing. Two forces, hospital downsizing and advancing technology, are identified as the major contributors to the shift in acute care delivery. The effects that these changes are having on the clinical nursing practice of registered nurses working in AAC settings are not known. Given that AAC settings are rapidly expanding, it can be anticipated that the delivery of nursing care will continue to be compressed into a shorter time frame. Therefore, the following qualitative research question was formulated: What are the problems and issues related to clinical nursing practice in acute ambulatory settings? The purpose of this study was to explore the problems and issues associated with change and clinical nursing practice including the educational needs of nurses working in MC settings. Specific objectives of the study included the following: (a) to explore the problems and issues related to nursing practice in select AAC settings; (b) to explore the similarities and differences in perspectives related to role expectation between nurse managers, nurse educators, and staff nurses; and (c) to develop a conceptual framework that will guide the construction of an instrument needed for further research. This study used semistructured individual interviews and focus group sessions to collect data from the three categories of registered nurses. More specifically, data were collected from one nurse manager, two charge nurses, two nurse educators and fifteen staff nurses, working in three different MC settings of a major teaching hospital. Collected data were separately analyzed by the researcher and an external rater following grounded theory methodology. By using open and axial coding, the problems and issues identified by nurses were grouped into several major and minor themes. In final analysis, by using selective coding, the four core themes (intensification, moderation, frustration, and adaptation) were extracted. Each core theme was presented and discussed in relation to hospital downsizing and advancing technology. The relationships among the four core themes were discussed and depicted in a model termed the "Impact and Consequence Model on Nursing Practice in MC Settings." Implications for further research are discussed and research hypotheses, based on the research findings, are presented.

The effects of temperature on nickel tocicity in goldfish (carassius auratus L.)

Although it is widely assumed that temperature affects pollutant toxicity, few studies have actually investigated this relationship. Moreover, such research as has been done has involved constant temperatures; circumstances which are rarely, if ever, actually experienced by north temperate, littoral zone cyprinid species. To investigate the effects of temperature regime on nickel toxicity in goldfish (Carassius auratus L.), 96- and 240-h LCSO values for the heavy metal pollutant, nickel (NiCI2.6H20), were initially determined at 2DoC (22.8 mg/L and 14.7 mg/L in artificially softened water). Constant temperature bioassays at 10°C, 20°C and 30°C were conducted at each of 0, 240-h and 96-h LCSO nickel concentrations for 240 hours. In order to determine the effects of temperature variation during nickel exposure it was imperative that the effects of a single temperature change be investigated before addressing more complex regimes. Single temperature changes of + 10°C or -10°C were imposed at rates of 2°C/h following exposures of between 24 hand 216 h. The effects of a single temperature change on mortality, and duration of toxicant exposure at high and low temperatures were evaluated. The effects of fluctuating temperatures during exposure were investigated through two regimes. The first set of bioassays imposed a sinewave diurnal cycle temperature (20.±.1DOC) throughout the 10 day exposure to 240-h LeSO Ni. The second set of investigations approximated cyprinid movement through the littoral zone by imposing directionally random temperature changes (±2°C at 2-h intervals), between extremes of 10° and 30°C, at 240-h LC50 Ni. Body size (i.e., total length, fork length, and weight) and exposure time were recorded for all fish mortalities. Cumulative mortality curves under constant temperature regimes indicated significantly higher mortality as temperature and nickel concentration were increased. At 1DOC no significant differences in mortality curves were evident in relation to low and high nickel test concentrations (Le., 16 mg/L and 20 mg/L). However at 20°C and 30°C significantly higher mortality was experienced in animals exposed to 20 mg/L Ni. Mortality at constant 10°C was significantly lower than at 30°C with 16 mg/L and was significantly loWer than each of 2DoC and 39°C tanks at 20 mg/L Ni exposure. A single temperature shift from 20°C to 1DoC resulted in a significant decrease in mortality rate and conversely, a single temperature shift from 20°C to 30°C resulted in a significant increase in mortality rate. Rates of mortality recorded during these single temperature shift assays were significantly different from mortality rates obtained under constant temperature assay conditions. Increased Ni exposure duration at higher temperatures resulted in highest mortality. Diurnally cycling temperature bioassays produced cumulative mortality curves approximating constant 20°C curves, with increased mortality evident after peaks in the temperature cycle. Randomly fluctuating temperature regime mortality curves also resembled constant 20°C tanks with mortalities after high temperature exposures (25°C - 30°C). Some test animals survived in all assays with the exception of the 30°C assays, with highest survival associated with low temperature and low Ni concentration. Post-exposure mortality occurred most frequently in individuals which had experienced high Ni concentrations and high temperatures during assays. Additional temperature stress imposed 2 - 12 weeks post exposure resulted in a single death out of 116 individuals suggesting that survivors are capable of surviving subsequent temperature stresses. These investigations suggest that temperature significantly and markedly affects acute nickel toxicity under both constant and fluctuating temperature regimes and plays a role in post exposure mortality and subsequent stress response.

The effects of gramicidin on the structure of phospholipid assemblies /

Gramicidin is an antibiotic peptide that can be incorporated into the monolayers of cell membranes. Dimerization through hydrogen bonding between gramicidin monomers in opposing leaflets of the membrane results in the formation of an iontophoretic channel. Surrounding phospholipids, with various associated mechanical properties, have been shown to influence the gating properties of this channel. Conversely, gramicidin incorporation has been shown to affect the structure of spontaneously formed lipid assemblies. Using small-angle x-ray diffraction and model systems composed of phospholipids and gramicidin, the physical effects incurred by gramicidin incorporation were measured. The reverse hexagonal (H^) phase composed of dioleoylphosphatidylethanolamine (DOPE) monolayers decreased in lattice dimension with increasing incorporation of gramicidin. This indicated that gramicidin was adding negative curvature to the monolayers. In this system, gramicidin was measured to have an apparent intrinsic radius of curvature (Rop*™") of -7. 1 A. The addition of up to 4 mol% gramicidin in mixtures with DOPE did not result in the monolayers becoming stiffer, as indicated by unaltered bending moduli for each composition. Dioleoylphosphatidylcholine (DOPC) alone forms the lamellar (LJ phase when hydrated, but undergoes a transition into the H^ phase when mixed with gramicidin. The lattice repeat dimension decreases systematically with increased gramicidin content. Again, this indicated that gramicidin was adding negative curvature to the monolayers. At 12 mol% gramicidin in mixtures with DOPC, the apparent radius of intrinsic curvature of gramicidin (Rop*"^) was measured to be -7.4 A. This mixture formed monolayers that were very resistant to bending under osmotic pressure, with a measured bending modulus of 1 15 kT. The measurements made in this study demonstrate that peptides are able to modulate the spontaneous curvature and other mechanical properties of phospholipid assemblies.

Biological effects of resveratrol on skeletal muscle cells

Resveratrol, a polyphenol found in red wine, has been reported to have antithrombotic, antiatherogenic, and anticancer properties both in vitro and III VIVO. However, possible antidiabetic properties of resveratrol have not been examined. The objective of this study was to investigate the direct effects of resveratrol on basal and insulin-stimulated glucose uptake and to elucidate its mechanism of action in skeletal muscle cells. In addition, the effects of resveratrol on basal and insulin- stimulated amino acid transport and mitogenesis were also examined. Fully differentiated L6 rat skeletal muscle cells were incubated with resveratrol concentrations ranging from 1 to 250 IlM for 15 to 120 min. Maximum stimulation, 201 ± 8.90% of untreated control, (p<0.001), of2eH] deoxy- D- glucose (2DG) uptake was seen with 100 IlM resveratrol after 120 min. Acute, 30 min, exposure of the cells to 100 nM insulin stimulated 2DG uptake to 226 ± 12.52% of untreated control (p<0.001). This appears to be a specific property of resveratrol that is not shared by structurally similar antioxidants such as quercetin and rutin, both of which did not have any stimulatory effect. Resveratrol increased the response of the cells to submaximal insulin concentrations but did not alter the maximum insulin response. Resveratrol action did not require insulin and was not blocked by the protein synthesis inhibitor cycloheximide. L Y294002 and wortmannin, inhibitors of PI3K, abolished both insulin and resveratrolstimulated glucose uptake while phosphorylation of AktlPKB, ERK1I2, JNK1I2, and p38 MAPK were not increased by resveratrol. Resveratrol did not stimulate GLUT4 transporter translocation in GLUT4cmyc overexpressing cells, in contrast to the significant translocation observed with insulin. Furthermore, resveratrol- stimulated glucose transport was not blocked by the presence of the protein kinase C (PKC) inhibitors BIMI and G06983. Despite that, resveratrol- induced glucose transport required an intact actin network, similar to insulin. In contrast to the stimulatory effect seen with resveratrol for glucose transport, e4C]methylaminoisobutyric acid (MeAIB) transport was inhibited. Significant reduction of MeAIB uptake was seen only with 100uM resveratrol (74.2 ± 6.55% of untreated control, p<0.05), which appeared to be maximum. In parallel experiments, insulin (100 nM, 30 min) increased MeAIB transport by 147 ± 5.77% (p<0.00l) compared to untreated control. In addition, resveratrol (100 JlM, 120 min) completely abolished insulin- stimulated amino acid transport (103 ± 7.35% of untreated control,p>0.05). Resveratrol also inhibited cell proliferation in L6 myoblasts with maximal inhibition of eH]thymidine incorporation observed with resveratrol at 50 J.LM after 24 hours (8 ± 1.59% of untreated control, pon (280 ± 9.92% of untreated control, pontaining 10% FBS resulted in stimulation of thymidine incorporation to 691 ± 36.92% of untreated control, pof untreated control,pof untreated control, p<0.05) cell proliferation. These results suggest that resveratrol increases glucose transport in L6 skeletal muscle cells by a mechanism that is in4ependent of insulin and protein synthesis. Resveratrol- stimulated glucose uptake may be PI3K and actin cytoskeleton- dependent and independent of AktIPKB, PKC, ERK1I2, JNK1I2, p38 MAPK, and GLUT4 translocation. However, unlike glucose transport, resveratrol inhibits both basal and insulin- stimulated amino acid transport and mitogenesis.

Effects of naringenin on glucose uptake in L6 skeletal muscle cells

Diabetes mellitus is a disorder of inadequate insulin action and consequent high blood glucose levels. Type 2 diabetes accounts for the majority of cases of the disease and is characterized by insulin resistance and relative insulin deficiency resulting in metabolic deregulation. It is a complex disorder to treat as its pathogenesis is not fully understood and involves a variety of defects including ~-cell failure, insulin resistance in the classic target tissues (adipose, muscle, liver), as well as defects in a-cells and kidney, brain, and gastrointestinal tissue. Present oral treatments, which aim at mimicking the effects of insulin, remain limited in their efficacy and therefore the study of the effects of novel compounds on insulin target tissues is an important area of research both for potentially finding more treatment options as well as for increasing our knowledge of metabolic regulation in health and disease. In recent years the extensively studied polyphenol, resveratrol, has been reported to have antidiabetic effects showing that it increases glucose uptake by skeletal muscle cells and prevents fatty acid-induced insulin resistance in vitro and in vivo. Naringenin, a citrus flavonoid with structural similarities to resveratrol, is reported to have antioxidan.t, antiproliferative, anticancer, and anti-inflammatory properties. Effects on glucose and lipid metabolism have also been reported including blood glucose and lipid lowering effects. However, whether naringenin has insulinlike effects is not clear. In the present study the effects of naringenin on glucose uptake in skeletal muscle cells are examined and compared with those of insulin. Naringenin treatment of L6 myotubes increased glucose uptake in a dose- and time dependent manner and independent of insulin. The effects of naringenin on glucose uptake achieved similar levels as seen with maximum insulin stimulation and its effect was additive with sub-maximal insulin treatment. Like insulin naringenin treatment did not increase glucose uptake in myoblasts. To elucidate the mechanism involved in naringenin action we looked at its effect on phosphatidylinositol 3-kinase (PI3K) and Akt, two signalling molecules that are involved in the insulin signalling cascade leading to glucose uptake. Naringenin did not stimulate basal or insulinstimulated Akt phosphorylation but inhibition of PI3K by wortmannin partially repressed the naringenin-induced glucose uptake. We also examined naringenin's effect on AMP-activated protein kinase (AMPK), a molecule that is involved in mediating glucose uptake by a variety of stimuli. Naringenin stimulated AMPK phosphorylation and this effect was not inhibited by wortmannin. To deduce the nature of the naringenin-stimulated AMPK phosphorylation and its impact on glucose uptake we examined the role of several molecules implicated in mod.ulating AMPK activity including SIRTl, LKB 1, and ca2+ Icalmodulin-dependent protein kinase kinase (CaMKK). Our results indicate that inhibition of SIRTI did not prevent the naringeninstimulated glucose uptake Of. AMPK phosphorylation; naringenin did not stimulate LKB 1 phosphorylation; and inhibition of CaMKK did not prevent naringeninstimulated glucose uptake. Inhibition of AMPK by compound C also did not prevent naringenin-stimulated glucose uptake but effectively inhibited the phosphorylation of AMPK suggesting that AMPK may not be required for the naringenin-stimulated glucose uptake.

Effects of age on learning a spatial motor task in younger and older adults individualizing their knowledge of results schedule

Self-controlled KR practice has revealed that providing participants the opportunity to control their KR is superior for motor learning compared to participants replicating the KR schedule of a self-control participant, without the choice (e.g., yoked). The purpose of the present experiment was two-fold. First, to examine the utility of a self-controlled KR schedule for learning a spatial motor task in younger and older adults and second, to determine whether a self-controlled KR schedule facilitates an increased ability to estimate one’s performance in retention and transfer. Twenty younger adults and 20 older adults practiced in either the self-control or yoked condition and were required to push and release a slide along a confined pathway using their non-dominant hand to a target distance. The retention data revealed that as a function of age, a self-controlled KR schedule facilitated superior retention performance and performance estimations in younger adults compared to their yoked counterparts.