898 research outputs found
The Fluctuating Workweek: How It Works, How It’s Treated, How It’s Perceived
[Excerpt] “This article argues that the fluctuating workweek method of overtime compensation is a viable alternative to the traditional method of overtime compensation. First, it will explain how the fluctuating workweek works and how state courts have treated it. Second, it will debunk several misconceptions about the fluctuating workweek. Finally, it will show that employers are working small numbers of employees for long hours because paying overtime is cheaper today than hiring new employees
Activation of AMP-activated protein kinase by metformin induces protein acetylation in prostate and ovarian cancer cells
AMP-activated protein kinase (AMPK) is an energy sensor and master regulator of metabolism. AMPK functions as a fuel gauge monitoring systemic and cellular energy status. Activation of AMPK occurs when the intracellular AMP/ATP ratio increases and leads to a metabolic switch from anabolism to catabolism. AMPK phosphorylates and inhibits acetyl-CoA carboxylase (ACC), which catalyzes carboxylation of acetyl-CoA to malonyl-CoA, the first and rate-limiting reaction in de novo synthesis of fatty acids. AMPK thus regulates homeostasis of acetyl-CoA, a key metabolite at the crossroads of metabolism, signaling, chromatin structure, and transcription. Nucleocytosolic concentration of acetyl-CoA affects histone acetylation and links metabolism and chromatin structure. Here we show that activation of AMPK with the widely used antidiabetic drug metformin or with the AMP mimetic 5-aminoimidazole-4-carboxamide ribonucleotide increases the inhibitory phosphorylation of ACC and decreases the conversion of acetyl-CoA to malonyl-CoA, leading to increased protein acetylation and altered gene expression in prostate and ovarian cancer cells. Direct inhibition of ACC with allosteric inhibitor 5-(tetradecyloxy)-2-furoic acid also increases acetylation of histones and non-histone proteins. Because AMPK activation requires liver kinase B1, metformin does not induce protein acetylation in liver kinase B1-deficient cells. Together, our data indicate that AMPK regulates the availability of nucleocytosolic acetyl-CoA for protein acetylation and that AMPK activators, such as metformin, have the capacity to increase protein acetylation and alter patterns of gene expression, further expanding the plethora of metformin's physiological effects
HGF modulates actin cytoskeleton remodeling and contraction in testicular myoid cells
The presence of the HGF/Met system in the testicular myoid cells was first discovered by our group. However, the physiological role of this pathway remains poorly understood. We previously reported that HGF increases uPA secretion and TGF-β activation in cultured tubular fragments and that HGF is maximally expressed at
Stages VII–VIII of the seminiferous epithelium cycle, when myoid cell contraction occurs. It is well known that the HGF/Met pathway is involved in cytoskeletal remodeling; moreover, the interaction of uPA with its receptor, uPAR, as well as the activation of
TGF-β have been reported to be related to the actin cytoskeleton contractility of smooth muscle cells. Herein, we report that HGF induces actin cytoskeleton remodeling in vitro in isolated myoid cells and myoid cell contraction in cultured seminiferous tubules. To better understand these phenomena, we evaluated: (1) the regulation of the uPA machinery in isolated myoid cells after HGF administration; and (2) the effect of uPA or Met inhibition on HGF-treated tubular fragments. Because uPA activates latent TGF-β, the secretion of this factor was also evaluated. We found that both uPA and TGF-β activation increase after HGF administration. In testicular tubular fragments, HGF-induced TGF-β activation and myoid cell contraction are abrogated by uPA or Met inhibitor administratio
Chlordiazepoxide Increases Risky Choice
Probability discounting is a measure of risky choice that is correlated with maladaptive behavior and psychological disorders. Benzodiazepines are a class of drug on which relatively little risky-choice research has been conducted, particularly under conditions of chronic drug exposure. Chlordiazepoxide, a standard benzodiazepine, was administered to rats that had been trained to respond on a risky-choice task in which a choice was available between a single food pellet with 100% certainty or three food pellets with probabilities of delivery that decreased across each experimental session. During baseline, responding was sensitive to the programmed contingencies and larger-reinforcer choice decreased as the probability of delivery decreased. Acute administration of chlordiazepoxide dose-dependently increased risky choice. Tolerance to chlordiazepoxide’s effects on larger-reinforcer-choice was observed after chronic drug exposure. The results of the present study indicate that acute chlordiazepoxide can increase risky choice in a probability-discounting task and that tolerance to this effect develops after chronic exposure to the drug. Limitations of the probability-discounting task and its relation to the hypothetical construct “risky choice” are discussed, as are suggestions for additional pharmacological targets and procedural variations for future studies on benzodiazepines, the GABA system, and risky choice
Delay Discounting and Cannabinoid Enzyme Inhibitors
Delay discounting is a measure of impulsive choice that is correlated with maladaptive behavior and psychological disorders. Disruptions to serotonin and dopamine pathways can cause changes in delay discounting, as can lesions to the prefrontal cortex and nucleus accumbens. The endocannabinoid system modulates other neurotransmitter systems, including dopamine and serotonin pathways. Cannabinoid receptors type 1 are found in relatively high concentrations in the nucleus accumbens and the prefrontal cortex. These receptors are activated by endogenous cannabinoids, which are synthesized on demand and broken down by catabolic enzymes. The action of these enzymes can be inhibited by a class of drugs known as cannabinoid enzyme inhibitors, which ultimately produce higher levels of endogenous cannabinoids by preventing their catabolic degradation. The present study examined effects of two cannabinoid enzyme inhibitors, URB597 and JZL195, on delay discounting in rats. Delay discounting was measured at baseline and after drug administration. Area under the curve and indifference points were not affected by any dose of either drug, but 7.5 mg/kg of JZL195 decreased percent larger-reinforcer choice at the lowest delay value and increased it at the highest delay value. URB597 increase percent larger-reinforcer choice only at one intermediate delay value. JZL195 increased response latencies at the 7.5 mg/kg dose. No systematic, dose-dependent effect of either drug on measures of delay discounting was observed
Homocysteine plasma levels as a marker of clinical severity in septic patients
OBJECTIVE: Homocysteine and sepsis are both associated with inflammation and endothelial activation. Therefore this study was aimed to evaluate if the plasma homocystein level is related with the septic patient clinical severity. METHODS: Severe sepsis or septic shock patients, with less than 48 hours from organ dysfunction start, were admitted to this prospective observational study. Homocysteine levels were determined by the time of study admission and then on the Days 3, 7 and 14. The homocysteine association with the Sequential Organ Failure Assessment (SOFA) score was evaluated using the Sperman test, and its association with mortality using the Mann-Whitney test. A p<0.05 value was considered statistically significant. RESULTS: Twenty one patients were enrolled, and 60 blood samples were collected to measure total homocysteine [median 6.92 (5.27 - 9.74 μmol/L)]. The Sperman correlation test showed no association between homocysteine and SOFA ( r=0.15 and p=0.26). Also no correlation was found for the homocysteine level by the study admission time and the difference between the Day 3 SOFA score versus by study admission (deltaSOFA) (r=0.04 and p=0.87). Homocysteine variation between the Day 3 and the study admission (deltaHmc) and SOFA score variation in the same period were not correlated (r=-0.11 and p=0.66). Homocysteine by the study admission was not correlated with death in intensive care unit rate (p= 0.46) or in-hospital death rate (p = 0.13). This was also true for deltaHmc (p=0.12 and p=0.99, respectively). CONCLUSION: Baseline homocysteine levels and its variations within the first dysfunction days were not related with septic patients' worsened organ function parameters or mortality.OBJETIVO: Homocisteína e a sepse estão ambos associados à inflamação e ativação endotelial. O objetivo desse estudo foi verificar se o nível plasmático de homocisteína está relacionado à gravidade do quadro séptico. MÉTODOS: Estudo clínico, prospectivo e observacional, incluindo pacientes com sepse grave ou choque séptico com menos de 48 horas de instalação da disfunção orgânica. Os níveis de homocisteína foram determinados no dia da inclusão no estudo e nos dias 3, 7, 14. A associação entre homocisteína com o escore Sequential Organ Failure Assessment (SOFA) foi avaliada pelo teste de Sperman e com mortalidade pelo teste de Mann-Whitney. Os resultados foram considerados significativos se p<0,05. RESULTADOS: Foram incluídos 21 pacientes e feitas 60 coletas para avaliação da homocisteina total (mediana de 6,92 (5,27 - 9,74 μmol/l). O teste de correlação Spearman não mostrou associação entre homocisteina e SOFA (r = -0,15 e p = 0,26). Também não foi encontrada correlação da medida de homocisteína na data de admissão do estudo e a diferença do SOFA obtido no 3º dia e o SOFA da admissão (deltaSOFA) (r = 0,04 e p = 0,87). A variação da homocisteína do 3º dia e a admissão no estudo (deltaHmc) e a variação do SOFA no mesmo período não estavam correlacionadas (r = -0,11 e p = 0,66). A homocisteina da admissão não se correlacionou com mortalidade na UTI (p=0,46) ou com a mortalidade hospitalar.(p=0,13). Mesmo quando foi utilizado o deltaHmc não houve correlação (p=012 e p=0,99, respectivamente). CONCLUSÃO: O nível basal de homocisteína ou sua variação nos primeiros dias da disfunção não estiveram relacionadas com a piora dos parâmetros funcionais dos sistemas orgânicos ou mortalidade nos pacientes sépticos.Universidade Federal de São Paulo (UNIFESP) Setor de Terapia Intensiva da Disciplina de Anestesiologia, Dor e Terapia IntensivaUniversidade Federal de São Paulo (UNIFESP)UNIFESP, Setor de Terapia Intensiva da Disciplina de Anestesiologia, Dor e Terapia IntensivaUNIFESPSciEL
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