Based on the multitarget strategy, a series of novel clioquinol-1-benzyl-1,2,3,6-tetrahydropyridine hybrids were identified for the potential treatment of Alzheimer's disease (AD). Biological evaluation in vitro revealed that these hybrids exhibited significant inhibitory activities toward acetylcholinesterase (AChE). The optimal compound, 19n, exhibited excellent AChE inhibitory potency (IC(50) = 0.11 microM), appropriate metal chelating functions, modulation of AChE- and metal-induced Abeta aggregation, neuroprotection against okadaic acid-induced mitochondrial dysfunction and ROS damage, and interesting properties that reduced p-Tau levels in addition to no toxicity on SH-SY5Y cells observed at a concentration up to 50 microM. Most importantly, compound 19n was more well tolerated (>1200 mg/kg) than donepezil (LD(50) = 28.124 mg/kg) in vivo. Moreover, compound 19n demonstrated marked improvements in cognitive and spatial memory in two AD mice models (scopolamine-induced and Abeta(1-42)-induced) and suppressed inflammation induced by Abeta(1-42) in the cortex. The multifunctional profiles of compound 19n demonstrate that it deserves further investigation as a promising lead in the development of innovatively multifunctional drugs for Alzheimer's disease.
Based on a multitarget strategy, a series of novel chromanone-1-benzyl-1,2,3,6-tetrahydropyridin hybrids were identified for the potential treatment of Alzheimer's disease (AD). Biological evaluation demonstrated that these hybrids exhibited significant inhibitory activities toward acetylcholinesterase (AChE) and monoamine oxidase B (MAO-B). The optimal compound C10 possessed excellent dual AChE/MAO-B inhibition both in terms of potency and equilibrium (AChE: IC(50) = 0.58 0.05 M; MAO-B: IC(50) = 0.41 0.04 M). Further molecular modeling and kinetic investigations revealed that compound C10 was a dual-binding inhibitor bound to both the catalytic anionic site and peripheral anionic site of AChE. In addition, compound C10 exhibited low neurotoxicity and potently inhibited AChE enzymatic activity. Furthermore, compound C10 more effectively protected against mitochondrial dysfunction and oxidation than donepezil, strongly inhibited AChE-induced amyloid aggregation, and moderately reduced glutaraldehyde-induced phosphorylation of tau protein in SH-SY5Y cells. Moreover, compound C10 displayed largely enhanced improvements in cognitive behaviors and spatial memory in a scopolamine-induced AD mice model with better efficacy than donepezil. Overall, the multifunctional profiles of compound C10 suggest that it deserves further investigation as a promising lead for the prospective treatment of AD.
A series of sulfone analogs of donepezil were designed and synthesized as novel acetylcholinesterase (AChE) inhibitors with the potent inhibiting Abeta aggregation and providing neuroprotective effects as potential modalities for Alzheimer's disease (AD). Most of the target compounds displayed effective inhibition of AChE, especially compound 24r which displayed powerful inhibitory activity (IC(50) = 2.4 nM). Kinetic and docking studies indicated that compound 24r was a mixed-type inhibitor. Furthermore, in glyceraldehyde (GA)-exposed SH-SY5Y differentiated neuronal cells, compound 24r could potently inhibit AChE, reduce tau phosphorylation at S396 residue, provide neuroprotection by rescuing neuronal morphology and increasing cell viability. It was also found to reduce amyloid aggregation in the presence of AChE. In addition, compound 24r showed evident protections from mitochondrial membrane dysfunction and oxidative stress in okadaic acid-induced pharmacological models. Moreover, compound 24r exhibited more effective treatment prospects in vivo than donepezil, including a moderate blood-brain barrier permeability, a more potent AChE inhibitory activity and behavioral improvement in scopolamine-induced cognition-impaired mice model at a much lower dose. Collectively, compound 24r is a promising lead compound for further investigation to discovery and development of new anti-AD agents.
BACKGROUND: Prescribing medications for nursing home residents with advanced dementia should focus on optimizing function and comfort, reducing unnecessary harms and aligning care goals with a palliative approach. OBJECTIVE: The aim of the study was to estimate the proportion of Australian nursing home residents with advanced dementia receiving potentially inappropriate medications, and identify those most commonly prescribed and factors associated with their use. DESIGN: Data were collected through retrospective audit of medication charts. SETTING/SUBJECTS: Two hundred eighteen nursing home residents with advanced dementia from 20 nursing homes participated in a cluster-randomized controlled trial of case conferencing (the IDEAL Study) from June 2013 to December 2014. MEASUREMENTS: Inappropriate drug use was defined as medications classified as "never appropriate" by the Palliative Excellence in Alzheimer Care Efforts (PEACE) program criteria. Generalized linear mixed models were used to identify variables predicting use of "never" appropriate medications. RESULTS: Over a quarter (n = 65, 30%) of residents received at least one medication classed as "never" appropriate, the most common being lipid-lowering agents (n = 38, 17.4%), antiplatelet agents (n = 18, 8.3%), and acetylcholinesterase inhibitors (n = 16, 7.3%). Residents who had been at the nursing home for <=10 months (odds ratio [OR] 5.60, 95% confidence interval [CI] 1.74-18.06) and 11-21 months (OR 5.41, 95% CI 1.67-17.75) had significantly greater odds of receiving a never appropriate medication compared with residents who had been at the nursing home for >5 years. CONCLUSIONS: Use of potentially inappropriate medications in Australian nursing home residents with advanced dementia is common. A greater understanding of the rationale that underpins prescribing of medications is required.
The draft genome of the moss model, Physcomitrella patens, comprised approximately 2000 unordered scaffolds. In order to enable analyses of genome structure and evolution we generated a chromosome-scale genome assembly using genetic linkage as well as (end) sequencing of long DNA fragments. We find that 57% of the genome comprises transposable elements (TEs), some of which may be actively transposing during the life cycle. Unlike in flowering plant genomes, gene- and TE-rich regions show an overall even distribution along the chromosomes. However, the chromosomes are mono-centric with peaks of a class of Copia elements potentially coinciding with centromeres. Gene body methylation is evident in 5.7% of the protein-coding genes, typically coinciding with low GC and low expression. Some giant virus insertions are transcriptionally active and might protect gametes from viral infection via siRNA mediated silencing. Structure-based detection methods show that the genome evolved via two rounds of whole genome duplications (WGDs), apparently common in mosses but not in liverworts and hornworts. Several hundred genes are present in colinear regions conserved since the last common ancestor of plants. These syntenic regions are enriched for functions related to plant-specific cell growth and tissue organization. The P. patens genome lacks the TE-rich pericentromeric and gene-rich distal regions typical for most flowering plant genomes. More non-seed plant genomes are needed to unravel how plant genomes evolve, and to understand whether the P. patens genome structure is typical for mosses or bryophytes.
Title: Investigating nicotinic acetylcholine receptor expression in neonicotinoid resistant Myzus persicae FRC Beckingham C, Phillips J, Gill M, Crossthwaite AJ Ref: Pesticide Biochemistry and Physiology, 107:293, 2013 : PubMed
The peach-potato aphid Myzus persicae is a pest of many commercial crops due to its polyphagous nature of feeding and has a well-documented history of acquiring resistance to insecticides. In 2009 a strain (M. persicae FRC) emerged in southern France with a point mutation (R81T) at the nicotinic acetylcholine receptor (nAChR), the target site for neonicotinoids such as imidacloprid. This point mutation was associated with the loss of the high affinity imidacloprid binding site (pM Kd), with the single remaining binding site (low nM Kd) highly overexpressed compared to laboratory controls (Bass et al., 2011 [1]). Here we report that after 2years of continuous selection in the glass house environment with neonicotinoids, the total level of IMD-sensitive nAChRs (low nM Kd) in M. persicae FRC is now comparable to laboratory controls (pM and low nM Kd). Interestingly, despite this large reduction in IMD-sensitive nAChRs, this was not associated with any significant alteration in NNIC-lethality. Additionally, sustained absence of neonicotinoid-selection did not alter nAChR protein levels. We suggest that alterations in nAChR protein expression level described in the original characterisation of the field-isolated M. persicae FRC is unlikely to have been a direct consequence of the R81T mutation. Rather, we speculate that nAChR expression in aphids is likely influenced by as yet unknown conditions in the natural field environment that are absent in the laboratory setting.
Title: The effect of combined therapy with ranitidine and pirenzepine in the treatment of reflux oesophagitis Londong W, Phillips J, Johnson NJ, Wood JR Ref: Aliment Pharmacol Ther, 6:609, 1992 : PubMed
The combination of a histamine H2-receptor antagonist and a muscarinic receptor antagonist has been reported to result in greater suppression of intragastric acidity than either agent alone. The present randomized, double-blind, multicentre trial compared the effects of the oral combination of 150 mg ranitidine b.d. plus 50 mg pirenzepine b.d. with 150 mg ranitidine b.d. plus placebo pirenzepine b.d. in the treatment of patients with reflux oesophagitis. All 157 patients had symptoms of gastro-oesophageal reflux with endoscopically confirmed oesophageal erosions (Savary and Miller grades I-III). After four weeks of treatment, healing rates were 32/75 (43%) in the combined treatment group and 34/76 (45%) in the group receiving ranitidine alone. After eight weeks, the cumulative healing rates had increased to 48/72 (67%) and 51/75 (68%), respectively. More patients receiving ranitidine plus pirenzepine had complete relief of day- and night-time heartburn after four weeks compared with those receiving ranitidine alone (day: 59% vs. 38%, P = 0.02; night: 69% vs. 52%, P = 0.04). After eight weeks, symptom relief was comparable in both groups. Clinical adverse effects were reported by nine patients receiving ranitidine and by 19 patients receiving the combination. It is concluded that combining ranitidine with pirenzepine does not aid the healing of reflux oesophagitis but does improve symptom relief at four weeks.
