Therapeutic TNF Inhibitors Exhibit Differential Levels of Efficacy in Accelerating Cutaneous Wound Healing

Adalimumab but neither etanercept nor certolizumab-pegol has been reported to induce a wound-healing profile in vitro by regulating macrophage differentiation and matrix metalloproteinase expression, which may underlie the differences in efficacy between various TNF-α inhibitors in impaired wound healing in patients with hidradenitis suppurativa, a chronic inflammatory skin disease. To examine and compare the efficacy of various TNF inhibitors in cutaneous wound healing in vivo, a human TNF knock-in Leprdb/db mouse model was established to model the impaired cutaneous wound healing as seen in hidradenitis suppurativa. The vehicle group exhibited severe impairments in cutaneous wound healing. In contrast, adalimumab significantly accelerated healing, confirmed by both histologic assessment and a unique healing transcriptional profile. Moreover, adalimumab and infliximab showed similar levels of efficacy, but golimumab was less effective, along with etanercept and certolizumab-pegol. In line with histologic assessments, proteomics analyses from healing wounds exposed to various TNF inhibitors revealed distinct and differential wound-healing signatures that may underlie the differential efficacy of these inhibitors in accelerating cutaneous wound healing. Taken together, these data revealed that TNF inhibitors exhibited differential levels of efficacy in accelerating cutaneous wound healing in the impaired wound-healing model in vivo.

eIF2B activator prevents neurological defects caused by a chronic integrated stress response

The integrated stress response (ISR) attenuates the rate of protein synthesis while inducing expression of stress proteins in cells. Various insults activate kinases that phosphorylate the GTPase eIF2 leading to inhibition of its exchange factor eIF2B. Vanishing White Matter (VWM) is a neurological disease caused by eIF2B mutations that, like phosphorylated eIF2, reduce its activity. We show that introduction of a human VWM mutation into mice leads to persistent ISR induction in the central nervous system. ISR activation precedes myelin loss and development of motor deficits. Remarkably, long-term treatment with a small molecule eIF2B activator, 2BAct, prevents all measures of pathology and normalizes the transcriptome and proteome of VWM mice. 2BAct stimulates the remaining activity of mutant eIF2B complex in vivo, abrogating the maladaptive stress response. Thus, 2BAct-like molecules may provide a promising therapeutic approach for VWM and provide relief from chronic ISR induction in a variety of disease contexts.

Effects of the novel α7 nicotinic acetylcholine receptor agonist ABT-107 on sensory gating in DBA/2 mice: pharmacodynamic characterization

Nicotinic acetylcholine receptor (nAChR) agonists improve sensory gating deficits in animal models and schizophrenic patients. The aim of this study was to determine whether the novel and selective α7 nAChR full agonist 5-(6-[(3R)-1-azabicyclo[2.2.2]oct-3-yloxy]pyridazin-3-yl)-1H-indole (ABT-107) improves sensory gating deficits in DBA/2 mice. Sensory gating was measured by recording hippocampal-evoked potential P20-N40 waves and determining gating test/conditioning (T/C) ratios in a paired auditory stimulus paradigm. ABT-107 at 0.1 μmol/kg (average plasma concentration of 1.1 ng/ml) significantly improved sensory gating by lowering T/C ratios during a 30-min period after administration in unanesthetized DBA/2 mice. ABT-107 at 1.0 μmol/kg was ineffective at 30 min after administration when average plasma levels were 13.5 ng/ml. However, the 1.0 μmol/kg dose was effective 180 min after administration when plasma concentration had fallen to 1.9 ng/ml. ABT-107 (0.1 μmol/kg) also improved sensory gating in anesthetized DBA/2 mice pretreated with α7 nAChR-desensitizing doses of nicotine (6.2 μmol/kg) or ABT-107 (0.1 μmol/kg) itself. Moreover, repeated b.i.d. dosing of ABT-107 (0.1 μmol/kg) was as efficacious as a single dose. The acute efficacy of ABT-107 (0.1 μmol/kg) was blocked by the nAChR antagonist methyllycaconitine, but not by the α4β2 nAChR antagonist dihydro-β-erythroidine. These studies demonstrate that ABT-107 improves sensory gating through the activation of nAChRs, and efficacy is sustained under conditions of repeated dosing or with prior nAChR activation with nicotine.

Pharmacological properties and procognitive effects of ABT-288, a potent and selective histamine H3 receptor antagonist

Blockade of the histamine H(3) receptor (H(3)R) enhances central neurotransmitter release, making it an attractive target for the treatment of cognitive disorders. Here, we present in vitro and in vivo pharmacological profiles for the H(3)R antagonist 2-[4'-((3aR,6aR)-5-methyl-hexahydro-pyrrolo[3,4-b]pyrrol-1-yl)-biphenyl-4-yl]-2H-pyridazin-3-one (ABT-288). ABT-288 is a competitive antagonist with high affinity and selectivity for human and rat H(3)Rs (K(i) = 1.9 and 8.2 nM, respectively) that enhances the release of acetylcholine and dopamine in rat prefrontal cortex. In rat behavioral tests, ABT-288 improved acquisition of a five-trial inhibitory avoidance test in rat pups (0.001-0.03 mg/kg), social recognition memory in adult rats (0.03-0.1 mg/kg), and spatial learning and reference memory in a rat water maze test (0.1-1.0 mg/kg). ABT-288 attenuated methamphetamine-induced hyperactivity in mice. In vivo rat brain H(3)R occupancy of ABT-288 was assessed in relation to rodent doses and exposure levels in behavioral tests. ABT-288 demonstrated a number of other favorable attributes, including good pharmacokinetics and oral bioavailability of 37 to 66%, with a wide central nervous system and cardiovascular safety margin. Thus, ABT-288 is a selective H(3)R antagonist with broad procognitive efficacy in rodents and excellent drug-like properties that support its advancement to the clinical area.

Discovery of 4-(5-(4-chlorophenyl)-2-methyl-3-propionyl-1H-pyrrol-1-yl)benzenesulfonamide (A-867744) as a novel positive allosteric modulator of the alpha7 nicotinic acetylcholine receptor

The discovery of a series of pyrrole-sulfonamides as positive allosteric modulators (PAM) of alpha7 nAChRs is described. Optimization of this series led to the identification of 19 (A-867744), a novel type II PAM with good potency and selectivity. Compound 19 showed acceptable pharmacokinetic profile across species and brain levels sufficient to modulate alpha7 nAChRs. In a rodent model of sensory gating, 19 normalized gating deficits. These results suggest that 19 represents a novel class of molecules capable of allosteric modulation of the alpha7 nAChRs.

Preclinical characterization of A-582941: a novel alpha7 neuronal nicotinic receptor agonist with broad spectrum cognition-enhancing properties

Among the diverse sets of nicotinic acetylcholine receptors (nAChRs), the alpha7 subtype is highly expressed in the hippocampus and cortex and is thought to play important roles in a variety of cognitive processes. In this review, we describe the properties of a novel biaryl diamine alpha7 nAChR agonist, A-582941. A-582941 was found to exhibit high-affinity binding and partial agonism at alpha7 nAChRs, with acceptable pharmacokinetic properties and excellent distribution to the central nervous system (CNS). In vitro and in vivo studies indicated that A-582941 activates signaling pathways known to be involved in cognitive function such as ERK1/2 and CREB phosphorylation. A-582941 enhanced cognitive performance in behavioral models that capture domains of working memory, short-term recognition memory, memory consolidation, and sensory gating deficit. A-582941 exhibited a benign secondary pharmacodynamic and tolerability profile as assessed in a battery of assays of cardiovascular, gastrointestinal, and CNS function. The studies summarized in this review collectively provide preclinical validation that alpha7 nAChR agonism offers a mechanism with potential to improve cognitive deficits associated with various neurodegenerative and psychiatric disorders.

Broad-spectrum efficacy across cognitive domains by alpha7 nicotinic acetylcholine receptor agonism correlates with activation of ERK1/2 and CREB phosphorylation pathways

The alpha7 nicotinic acetylcholine receptor (nAChR) plays an important role in cognitive processes and may represent a drug target for treating cognitive deficits in neurodegenerative and psychiatric disorders. In the present study, we used a novel alpha7 nAChR-selective agonist, 2-methyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole (A-582941) to interrogate cognitive efficacy, as well as examine potential cellular mechanisms of cognition. Exhibiting high affinity to native rat (Ki = 10.8 nM) and human (Ki = 16.7 nM) alpha7 nAChRs, A-582941 enhanced cognitive performance in behavioral assays including the monkey delayed matching-to-sample, rat social recognition, and mouse inhibitory avoidance models that capture domains of working memory, short-term recognition memory, and long-term memory consolidation, respectively. In addition, A-582941 normalized sensory gating deficits induced by the alpha7 nAChR antagonist methyllycaconitine in rats, and in DBA/2 mice that exhibit a natural sensory gating deficit. Examination of signaling pathways known to be involved in cognitive function revealed that alpha7 nAChR agonism increased extracellular-signal regulated kinase 1/2 (ERK1/2) phosphorylation in PC12 cells. Furthermore, increases in ERK1/2 and cAMP response element-binding protein (CREB) phosphorylation were observed in mouse cingulate cortex and/or hippocampus after acute A-582941 administration producing plasma concentrations in the range of alpha7 binding affinities and behavioral efficacious doses. The MEK inhibitor SL327 completely blocked alpha7 agonist-evoked ERK1/2 phosphorylation. Our results demonstrate that alpha7 nAChR agonism can lead to broad-spectrum efficacy in animal models at doses that enhance ERK1/2 and CREB phosphorylation/activation and may represent a mechanism that offers potential to improve cognitive deficits associated with neurodegenerative and psychiatric diseases, such as Alzheimer's disease and schizophrenia.

The influence of esmolol on the dose of propofol required for induction of anaesthesia

Cardiac output may be an important determinant of the induction dose of intravenous anaesthetic. Esmolol is known to reduce cardiac output, and we examined its effect on the propofol dose required for induction of anaesthesia. The size of the effect seen with esmolol was compared with midazolam co-induction. Sixty patients were randomly allocated to placebo (saline), esmolol (1mg x kg(-1) bolus, followed by an infusion at 250 microg x kg(-1)min(-1)) or midazolam (0.04 mg x kg(-1)) groups. Induction of anaesthesia commenced 3 min following the administration of the study drug, using a Diprifusor set to achieve plasma propofol concentrations of 10 microg x ml(-1) at 5 min. The primary end point used was the propofol dose per kg at loss of response to command. The mean (SD) propofol dose for each group was 2.38 (0.48) mg x kg(-1) for placebo, 1.79 (0.36) mg x kg(-1) for esmolol and 1.34 (0.35) mg x kg(-1) for midazolam (all means significantly different; p < 0.0005). We found that predosing with esmolol reduces the propofol requirements for induction of anaesthesia by 25%.

The use of tramadol following day--case oral surgery

This prospective, randomised double-blinded study was designed to assess the analgesic efficacy and occurrence of nausea when tramadol is added to a nonsteroidal anti-inflammatory drug to provide analgesia following day-case third molar teeth extraction. All patients received oral diclofenac pre-operatively and one of four treatments intra-operatively: fentanyl and metoclopramide, tramadol and metoclopramide, fentanyl and ondansetron, or tramadol and ondansetron. There were no significant differences between groups in scores for pain in the early postoperative period. However, there were significant differences in nausea scores at this time, with the fentanyl-ondansetron group having the lowest and the tramadol-ondansetron group having the highest scores. There were no significant differences in the incidence of pain or nausea in the following 24 h. We conclude that the addition of tramadol to diclofenac results in no useful improvement in analgesic effect, and that the use of ondansetron fails to reduce the nausea associated with tramadol.

Intravenous tenoxicam for analgesia following laparoscopic cholecystectomy

In a double-blind, placebo-controlled clinical trial (power of 80% to detect a 30% reduction in morphine consumption, P < 0.05) we have determined that intraoperative intravenous administration of tenoxicam 40 mg during laparoscopic cholecystectomy, when compared with placebo, was associated with a significant reduction in consumption of morphine at 6 hours and 12 hours (P < 0.05) but not at 24 hours, when assessed by patient-controlled analgesia. Furthermore there was a significantly greater requirement for "rescue" analgesia with intramuscular morphine in the placebo group during the period of the study. There was no difference between the groups in pain scores, either at rest or on movement, nor in the incidence of nausea and vomiting. No patient in either group suffered a respiratory rate less than 8/min or oversedation at any time, and there were no other adverse effects.

Effectiveness and sequelae of very low-dose suxamethonium for nasal intubation

We have studied the effectiveness and sequelae of low-dose suxamethonium in 60 day-case oral surgery patients requiring nasal intubation. Anaesthesia was induced with propofol and alfentanil; 60 patients were allocated randomly to three groups of 20 patients and received no suxamethonium, suxamethonium 0.25 mg kg-1 or 0.5 mg kg-1. All patients received i.v. fentanyl and diclofenac 100 mg rectally for analgesia. Good intubating conditions were produced in all 20 patients receiving suxamethonium 0.25 mg kg-1, in 19 patients receiving suxamethonium 0.5 mg kg-1 and in 11 patients not receiving a neuromuscular blocker. The incidence of postoperative myalgia after suxamethonium 0.25 mg kg-1 (20%) did not differ significantly from the incidence after propofol and alfentanil alone (28%).

Towards a standardized anaesthetic state using isoflurane and morphine

In 34 patients undergoing major surgery, the inspired isoflurane concentration was adjusted by a control system designed to maintain systolic arterial pressure at a predetermined value. An empirical rule allowed additional morphine administration if the demand of the system for isoflurane was excessive. Satisfactory control of systolic arterial pressure was achieved in 31 patients and the anaesthetic state was clinically acceptable to an independent observer; no awareness was reported and the mean recovery time was 9.6 min. In these patients, control of systolic arterial pressure produced a pattern of clinical signs recognizable as general anaesthesia.

Towards a standardized anaesthetic state using enflurane and morphine

General anaesthesia was maintained in 22 patients undergoing major surgery using a proportional-plus-integral control system. The system automatically adjusted the dose of enflurane according to the systolic arterial pressure (SAP). Additional morphine was administered if the system's demand for enflurane exceeded preset limits. In 21 patients, satisfactory control of SAP was achieved and anaesthesia was clinically adequate; no awareness was reported and the mean recovery time was 6.7 min (SD 3.5 min).