AZD-3043

A review of the use of fentanyl analgesia in the management of acute pain in adults.

Neuroprotective proteins expressed in the fetus play a critical role during early embryonic neurodevelopment, especially during maternal exposure to alcohol and drugs that cause stress, glutamate neuroexcitotoxicity, and damage to the fetal brain, if prolonged. We have identified a novel protein, carboxypeptidase E-ΔN (CPE-ΔN), which is a splice variant of CPE that has neuroprotective effects on embryonic neurons. CPE-ΔN is transiently expressed in mouse embryos from embryonic day 5.5 to postnatal day 1. It is expressed in embryonic neurons, but not in 3 week or older mouse brains, suggesting a function primarily in utero. CPE-ΔN expression was up-regulated in embryonic hippocampal neurons in response to dexamethasone treatment. CPE-ΔN transduced into rat embryonic cortical and hippocampal neurons protected them from glutamate- and H2O2-induced cell death. When transduced into embryonic cortical neurons, CPE-ΔN was found in the nucleus and enhanced the transcription of FGF2 mRNA. Embryonic cortical neurons challenged with glutamate resulted in attenuated FGF2 levels and cell death, but CPE-ΔN transduced neurons treated in the same manner showed increased FGF2 expression and normal viability. This neuroprotective effect of CPE-ΔN was mediated by secreted FGF2. Through receptor signaling, FGF2 activated the AKT and ERK signaling pathways, which in turn increased BCL-2 expression. This led to inhibition of caspase-3 activity and cell survival.

Previous work demonstrated that a brief, sublethal excitotoxic insult strikingly increased the sensitivity of cortical neurons to the cytotoxic effects of the terminal pathway of complement, a process termed "excitotoxic sensitization." Here, we sought to elucidate the cellular mechanism of excitotoxic sensitization in embryonic rat cortical neurons in vitro. Excitotoxic sensitization did not increase membrane attack complex deposition on cortical neurons and produced only a small reduction of membrane attack complex removal, because of a selective decrease of endocytic elimination. Membrane attack complexes and other osmotic stressors, namely hypotonic stress and glutamate, induced transient swelling of cortical neurons, followed by return to normal volume despite persistence of the stressor, a homeostatic response termed regulatory volume decrease (RVD). A minimal excitotoxic insult impaired this homeostatic response and sensitized neurons to cytotoxic effects of diverse osmotic stressors. Structurally distinct membrane-impermeable osmolytes, dextran and polyethylene glycol, prevented excitotoxic sensitization to diverse osmotic stressors including membrane attack complexes. Paraquat, a reactive oxygen species generator, alone was sufficient to impair RVD, and MnTBAP [Mn(III)tetrakis(4-benzoic acid)porphyrin chloride], a reactive oxygen species scavenger, prevented excitotoxin-mediated impairment of RVD. Together, these findings demonstrate that impairment of RVD is the mechanism of excitotoxic sensitization, that reactive oxygen species alone are sufficient to impair RVD, and that reactive oxygen species are necessary for excitotoxic sensitization-mediated impairment of RVD.

Cultured astrocytes deposit an extracellular matrix which has been shown by immunocytochemistry to react with antibodies to tenascin, laminin, and fibronectin. Neuronal-glial interaction down-regulates these components of the matrix, causing a reduction in extracellular matrix localized to areas of contact with axons. Axons used for these experiments were from embryonic rat retinal explants. In some experiments explants were removed from the co-cultures and their axons allowed to degenerate. Degeneration of axons did not reverse the local reduction of extracellular matrix brought about by axon outgrowth. The period of axon outgrowth studied was 4-5 days; the period of degeneration was 2-3 days. Astrocytes alone, astrocytes with intact retinal explants, and astrocytes with 2-day degenerated retinal axons were tested for their ability to support neurite outgrowth from embryonic rat cortical neurons. Neurite outgrowth occurred on all astrocyte cultures. Cortical neurite lengths, measured 2 days after plating, were not significantly different between astrocytes alone and astrocytes with degenerated retinal axons. However, there was a tendency for neurites to be shorter on astrocytes with intact retinal axons present. Two conclusions may be drawn from these results. First, the state of differentiation of astrocytes, as marked by their assembly of extracellular matrix, is altered by contact with axons. Second, degeneration of axons alone, in the absence of other cell types, is not a sufficient signal to reestablish assembly of extracellular matrix. However, neither is it a sufficient signal to render astrocytes inhospitable to further axonal outgrowth or regeneration.

The pharmacology, pharmacokinetics, efficacy, safety, dosage and administration, and place in therapy of clevidipine are reviewed. Clevidipine is a new lipophilic, short-acting, third-generation dihydropyridine calcium channel blocker (CCB) approved for use in the management of acute hypertension when oral agents are not feasible. It exerts its hemodynamic effects through selective arterial vasodilation without effects on the venous circulation. Clevidipine has a half-life of approximately two minutes after i.v. administration, resulting in very rapid onset and offset of antihypertensive action. Unlike many current i.v. antihypertensive agents that are metabolized by the kidneys or liver, clevidipine is metabolized in the blood and tissues and does not accumulate in the body. Clevidipine does not appear to inhibit or induce cytochrome P-450 isoenzymes. Several Phase III clinical trials have reported the clinical efficacy and safety of clevidipine in patients with severe hypertension and in cardiac surgical patients with perioperative hypertension. The most frequent adverse events reported in clinical trials of clevidipine were headache, nausea, and vomiting. Risk of rebound hypertension, especially in patients not transitioned from clevidipine to oral antihypertensive therapy after prolonged infusions, should be monitored for at least eight hours after the drug is discontinued. Clevidipine, a novel third-generation dihydropyridine CCB, has demonstrated efficacy and safety in patients with acute hypertension and preoperative, perioperative, and postoperative hypertension. While its short duration of action and short half-life are appropriate for use in acute settings, more information on its safety is needed to assess its appropriate use in therapy.

Neuronal network properties of human teratocarcinoma cell line-derived neurons

Background: Propofol is a widely-used intravenous anesthetic with a rapid onset, short duration of action and rapid elimination but the molecular mechanisms of action are not completely understood. Not only neurons but astrocytes are potential substrates for anesthetics, specifically for propofol. Intracellular calcium ion ([Ca2+]) is known to play a key role in the transduction and propagation of various chemical signals in astrocytes. Methods: In the present study, the effects of propofol on the intracellular calcium concentration of astrocytoma cells by using a fura-2 fluorescence spectroscopy was investigated. Results: In an isotonic standard solution, propofol (50 and 500 μM) produced a transient increase in [Ca2+]; while the intralipid did not change [Ca2+];. In several cells (20%), a transient increase in [Ca2+]; was followed by sustained elevation which was sensitive to depletion of external calcium. A propofol-induced increase in [Ca2+]; was not altered by an L-type calcium channel blocker (nifedipine 2μM). In cells bathed in a Ca2+ree external solution, a transient increase in [Ca2+ was observed. After the pretreatment of cyclopiazonic acid (CPA), an endoplasmic reticulum Ca2+-ATPase blocker, propofol 500 μM did not produce any significant increase in [Ca2+];. Carbachol, which is known to release calcium from the inositol 1,4,5-triphosphate (IP3)-induced calcium release (IICR) stores, prevented the [Ca2+]; increase by propofol and vice versa. High concentrations of caffeine (10 mM), which release calcium from the calcium-induced calcium release (CICR) stores, had no effect on [Ca2+]. Conclusions: From the above results, it is suggested that an increase in [Ca2+]; by propofol in astrocytoma cells is mainly due to calcium release from the IICR stores. (Korean J Anesthesiol 2001; 41: 337-346)

Comparative in vitro metabolism of phospho-tyrosol-indomethacin by mice, rats and humans

Neurotrophin-4/5 protects hippocampal and cortical neurons against energy deprivation- and excitatory amino acid-induced injury

Survival and neurite outgrowth of rat cortical neurons in three-dimensional agarose and collagen gel matrices

Retrograde axonal transport of BDNF and proNGF diminishes with age in basal forebrain cholinergic neurons

Acupuncture has obvious therapeutic effect on intracerebral hemorrhage (ICH). miR-34a-5p regulated by acupuncture was found to attenuate neurological deficits in ICH. However, the underlying mechanisms are unclear. Ubiquitin-like 4A (UBL4A) has not been studied in ICH. SD rats were injected with autologous blood to induce ICH and treated with Baihui-penetrating-Qubin acupuncture. Acupuncture resulted in an increase in forelimb placing test scores, and a decrease in corner test scores and brain water content of ICH rats. Histopathological examination showed that acupuncture inhibited ICH-induced inflammation, decreased damaged neurons and increased UBL4A expression. UBL4A overexpression increased cell viability, inhibited apoptosis, reduced reactive oxygen species (ROS) level and increased manganese superoxide dismutase (MnSOD) activity, mitochondrial membrane potential and mtDNA level in rat embryonic primary cortical neurons. miR-34a-5p knockdown increased UBL4A expression, apoptosis rate and ROS level in hemin-treated neurons. Dual luciferase assays showed that miR-34a-5p bound to UBL4A. Apoptotic cells and ROS level were increased in hemin-treated neurons with UBL4A and miR-34a-5p knockdown. We firstly demonstrate the inhibitory effect of UBL4A on neuronal apoptosis, and the regulation relationship between UBL4A and miR-34a-5p. This study provides a new candidate target for ICH treatment and more basis for elucidating the molecular mechanism of acupuncture. In the future, we will conduct a deeper exploration of the effects of UBL4A on ICH.

Intracerebral hemorrhage (ICH) is a primary non-traumatic parenchymal hemorrhage of the brain with a high mortality and disability rate. Acupuncture has been proved to alleviate neurological deficits after ICH. Our previous study found that UBL4A is up-regulated in the ICH rat treated with acupuncture, and may be a potential molecular target for acupuncture treatment of ICH. However, the molecular mechanism behind UBL4A is unclear. UBL4A knockdown was conducted in ICH rats with acupuncture treatment to explore its role in the therapeutic effects of acupuncture on ICH. In vitro, the effects of UBL4A on heme-induced neuronal injury were evaluated using E18 rat embryonic primary cortical neurons. Proteomic experiments were used to verify the regulatory relationship between UBL4A and MAPK14. UBL4A knockdown has opposite effects to the therapeutic effects of acupuncture on ICH, including increasing corner turn score, brain water content and the number of degenerated and apoptotic neuron in ICH rats. UBL4A knockdown increased the level of ROS, OPA1-S/L, p-MAPK14 and mitochondrial Drp1, and decreased mitochondrial membrane potential, ATP level and MFN2 level in rat brain tissue. In vitro, UBL4A overexpression reduced ROS level and mitochondrial membrane potential and inhibited the activation of the MAPK14/Drp1 signaling pathway. Co-IP verified the binding of UBL4A and MAPK14, and MAPK14 overexpression reversed the effect of UBL4A on hemin-induced neuronal apoptosis and ROS level. Our study confirms that UBL4A is involved in the therapeutic effect of acupuncture on ICH, and affects mitochondrial damage and oxidative stress through MAPK14 ubiquitination.

1. Chemical inhibition is the widely used method in reaction phenotyping assays for estimation of specific enzyme contribution to a given metabolic pathway. The results from phenotyping assays depend on the selectivity of chemical inhibitor and the concentration of inhibitor used in the incubation.2. The higher protein concentrations used in the in vitro phenotyping assays will impact the inhibitory potency of chemical inhibitors. The objective of the study is to evaluate comprehensively the selectivity of chemical inhibitors and to guide in selecting appropriate concentration of the chemical inhibitors to be used in the phenotyping assays based on unbound fractions.3. Selectivity of chemical inhibitors against nine major CYP450 isoforms was determined in liver microsomes using standard probe substrates. The unbound fractions of the selective inhibitors were determined in human liver microsomes using high-throughput equilibrium dialysis. Combining unbound inhibitor concentrations that are required to inhibit the CYP450 activities by 90% and unbound fractions of the chemical inhibitors in liver microsomes appropriate total concentrations of the inhibitors to be used in the phenotyping assays were reported.4. The findings suggest that non-specific binding of the chemical inhibitors need to be taken into account while selecting concentrations for phenotyping assays.

Effectiveness of remifentanil & propofol infusion for procedural sedation in patients undergoing gastrointestinal endoscopic procedures: a systematic review protocol