Ultrasonic-induced synthesis of novel diverse arylidenes via Knoevenagel condensation reaction. Antitumor, QSAR, docking and DFT assessment.

A series of arylidenes derivatives was synthesized under ultrasonic methodology via Knoevenagel condensation reaction of cyanoacetohydrazide derivative with the appropriate aldehydes and/or ketone. The anticancer properties of the newly synthesized compounds were tested against four different human cancer cell lines (HEPG-2, MCF-7, HCT-116, and PC-3); compounds 5d and 6 demonstrated the greatest anticancer activity against all cancer cell lines. The MLR technique was used to create the QSAR model using five molecular descriptors (AATS6p, AATS7p, AATS8p, AATS0i, and SpMax4_Bhv). The examination of the constructed QSAR model equations revealed that the selected descriptors influence the tested compound's anti-proliferative activity. The descriptors identified in this work by QSAR models can be utilized to predict the anticancer activity levels of novel arylidenes derivatives. This will allow for significant cost savings in the drug development process and synthesis at pharmaceutical chemistry laboratories. According to the physicochemical properties, the results revealed that all of these compounds comply with Lipinski's Rule of Five, indicating that they may have high permeability across biological membranes and reveal drug-relevant properties. The Swiss Target Prediction webtool was used to assess the probable cellular mechanism for the promising candidate compounds (5d and 6), and the results revealed that adenosine A1 receptor (ADORA1) was a common target for both compounds. ADORA1 is involved in the regulation of cell metabolism and gene transcription. ADORA1 overexpression has been linked to a variety of cancers, including colon cancer, breast cancer, leukemia, and melanoma. The docking study of tested compounds 5d and 6 revealed that their binding scores to ADORA1 are more favorable than those of its co-crystalized ligand (DU172, selective ADORA1 antagonist) and adenosine (ADORA1 endogenous agonist), implying that they may hold great promise as an anti-cancer therapy. Density functional theory (DFT) with a (B3LYP)/6-31G (d,p) basis set was used to calculate the physicochemical parameters of these compounds. The theoretical data from the DFT computation was found to be in good agreement with the experimental values.

Blockade of Type 2A Protein Phosphatase Signaling Attenuates Complement C1q-Mediated Microglial Phagocytosis of Glutamatergic Synapses Induced by Amyloid Fibrils.

We previously reported the critical involvement of metabotropic GluR1 (mGluR1) signaling in complement C1q-dependent microglial phagocytosis of glutamatergic synapses in a rat model of Alzheimer's disease (AD) injected with amyloid fibrils. Here, we explored the role of type 2A protein phosphatase (type 2A PPase), a key enzyme downstream of mGluR1 signaling, in the pathogenesis of AD in rats. Significant local upregulation of PP2A expression was observed in the hippocampal CA1 after bilateral microinjection of amyloid-beta (Aß1-40) fibrils. Amyloid fibrils induced remarkable dephosphorylation of pFMRP (fragile X mental retardation protein) and C1q upregulation in hippocampal glutamatergic synapses, which was ameliorated by microinjection of type 2A PPase inhibitor okadaic acid (OA). Microinjection of OA further attenuated the microglial phagocytosis of glutamatergic synapses, recovered the hippocampal glutamatergic transmission, and improved the performance in Morris water maze test. These findings demonstrated that dysfunction of type 2A PPase signaling contributed to complement C1q-dependent microglial phagocytosis of glutamatergic synapses and the cognitive impairments in the rat model of AD.

Suppression of hippocampal GABAergic transmission impairs memory in rodent models of Alzheimer's disease.

Emerging evidence demonstrates the potential involvement of hippocampal GABAergic transmission in the process of memory acquisition and consolidation, while no consistent report is available to address the adaptation of hippocampal GABAergic transmission and its contribution to memory deficiency in the setting of Alzheimer's disease (AD). Brain-derived neurotrophic factor (BDNF) is a key molecule that regulates GABAergic transmission. In the brain, mature BDNF is generated from the proteolytic cleavage of proBDNF, while BDNF and proBDNF have differential effects on central GABAergic transmission. First, the present study reports a remarkable increase of proBDNF/BNDF ratio in the hippocampal CA1 area in rodent models of AD, indicating a potential impaired process of BDNF maturation from proBDNF cleavage. We report a suppressed hippocampal GABAergic strength, potentially resulting from the reduced expression of anion chloride co-transporter KCC2 and subsequent positive shift of GABAergic Cl-equilibrium potential (ECl-), which is attenuated by microinjection of BDNF with proBDNF inhibitor TAT-Pep5. We also show that normalization of proBDNF/BDNF signaling or GABAergic ECl-by intracerebroventricular (i.c.v.) administration of bumetanide remarkably improves the cognitive performance in Morris water maze test and fear conditioning test in rodent models of AD. These results demonstrate a critical role of hippocampal proBDNF/BDNF in regulating GABAergic transmission and contributing to memory dysfunction in rodent models of AD.

Amyloid Fibril-Induced Astrocytic Glutamate Transporter Disruption Contributes to Complement C1q-Mediated Microglial Pruning of Glutamatergic Synapses.

The complement C1q plays a critical role in microglial phagocytosis of glutamatergic synapses and in the pathogenesis of neuroinflammation in Alzheimer's disease (AD). We recently reported that upregulation of metabotropic glutamate receptor signaling is associated with increased synaptic C1q production and subsequent microglial phagocytosis of synapses in the rodent models of AD. Here, we explored the role of astrocytic glutamate transporter in the synaptic C1q production and microglial phagocytosis of hippocampal glutamatergic synapses in a rat model of AD. Activation of astrocyte and reduction glutamate transporter 1 (GLT1) were noted after bilateral microinjection of amyloid-beta (Aß1-40) fibrils into the hippocampal CA1 area of rats. Ceftriaxone is a ß-lactam antibiotic that upregulates GLT1 expression. Bilateral microinjection of ceftriaxone recovered GLT1 expression, decreased synaptic C1q production, suppressed microglial phagocytosis of glutamatergic synapses in the hippocampal CA1, and attenuated synaptic and cognitive deficits in rats microinjected with Aß1-40. In contrast, artificial suppression of GLT1 activity by DL-threo-beta-benzyloxyaspartate (DL-TBOA) in naïve rats induced synaptic C1q expression and microglial phagocytosis of glutamatergic synapses in the hippocampal CA1 area, resulting in synaptic and cognitive dysfunction. These findings demonstrated that impairment of astrocytic glutamate transporter plays a role in the pathogenesis of AD.

Assessment of The Role of Serum Neutrophil Gelatinase-Associated Lipocalin in Egyptian Childhood Bronchial Asthma: One Centre Study.

Neutrophil gelatinase-associated lipocalin (NGAL) is emerging as a potential biomarker in many medical conditions including asthma. The aim of this study was to assess the role of serum NGAL in Egyptian childhood bronchial asthma. The study included 156 patients and 39 apparently healthy control children. Full clinical examination, pulmonary function tests; CBC, CRP, IgE, liver function tests, and renal function tests, and serum NGAL level were performed. The difference between the studied groups was statistically significant regarding IgE, eosinophils and NGAL (P= 0.001 for each). In addition, the difference between the subgroup with severe persistent asthma and the subgroup with mild intermittent asthma was significant (P=0.001). ROC curve analysis showed that at a cut-off value of 0.884 the sensitivity and specificity of differentiating severe bronchial asthma patients from controls was 82 % and 76 %, respectively. In conclusion, NGAL may represent a potential marker of bronchial asthma in children with severe disease.

Development of an efficient in vivo cell-based assay system for monitoring hepatitis C virus genotype 4a NS3/4A protease activity.

BACKGROUND: Hepatitis C virus (HCV) represents a serious worldwide healthcare problem. No protective vaccines against HCV have been developed yet due to the fact that HCV is rapidly mutable, allowing the virus to escape from the neutralizing antibodies. Understanding of HCV was initially hampered by the inability to achieve viral replication in cell culture. Given its essential roles in viral polyprotein processing and immune evasion, HCV NS3/4A protease is a prime target for antiviral chemotherapy. We aimed to establish in vivo cell-based assay system for monitoring the activity of NS3/4A protease from HCV genotype 4a, the predominant genotype in Egypt, and the Middle East. Furthermore, the developed system was used to evaluate the inhibitory potency of a series of computer-designed chemically-synthesized compounds against NS3/4A protease from HCV genotype 4a. MATERIALS AND METHODS: Native as well as mutant cleavage sites to NS3/4A protease were cloned in frame into ß-galactosidase gene of TA cloning vector. The target specificity of HCV NS3/4A was evaluated by coexpression of ß-galactosidase containing the protease cleavage site with NS3/4A protease construct in bacterial cells. The activity of ß-galactosidase was colorimetrically estimated in the cell lysate using orthonitro phenyl ß-D-galactopyanoside (ONPG) as a substrate. RESULTS AND CONCLUSIONS: We successfully developed an efficient cell-based system based on the blue/white selection of bacterial cells that are able to express functional/nonfunctional ß-galactosidase enzyme.

Anesthesiologists' Overconfidence in Their Perceived Knowledge of Neuromuscular Monitoring and Its Relevance to All Aspects of Medical Practice: An International Survey.

BACKGROUND: In patients who receive a nondepolarizing neuromuscular blocking drug (NMBD) during anesthesia, undetected postoperative residual neuromuscular block is a common occurrence that carries a risk of potentially serious adverse events, particularly postoperative pulmonary complications. There is abundant evidence that residual block can be prevented when real-time (quantitative) neuromuscular monitoring with measurement of the train-of-four ratio is used to guide NMBD administration and reversal. Nevertheless, a significant percentage of anesthesiologists fail to use quantitative devices or even conventional peripheral nerve stimulators routinely. Our hypothesis was that a contributing factor to the nonutilization of neuromuscular monitoring was anesthesiologists' overconfidence in their knowledge and ability to manage the use of NMBDs without such guidance. METHODS: We conducted an Internet-based multilingual survey among anesthesiologists worldwide. We asked respondents to answer 9 true/false questions related to the use of neuromuscular blocking drugs. Participants were also asked to rate their confidence in the accuracy of each of their answers on a scale of 50% (pure guess) to 100% (certain of answer). RESULTS: Two thousand five hundred sixty persons accessed the website; of these, 1629 anesthesiologists from 80 countries completed the 9-question survey. The respondents correctly answered only 57% of the questions. In contrast, the mean confidence exhibited by the respondents was 84%, which was significantly greater than their accuracy. Of the 1629 respondents, 1496 (92%) were overconfident. CONCLUSIONS: The anesthesiologists surveyed expressed overconfidence in their knowledge and ability to manage the use of NMBDs. This overconfidence may be partially responsible for the failure to adopt routine perioperative neuromuscular monitoring. When clinicians are highly confident in their knowledge about a procedure, they are less likely to modify their clinical practice or seek further guidance on its use.

Antimicrobial and anticancer activities of Scenedesmus obliquus metabolites.

This study was conducted to evaluate the antimicrobial activities and cytotoxicity of both crude extracts of Scenedesmus obliquus and their fractions. In vitro cytotoxicity assay against human hepatocellular carcinoma (HepG2), colon cancer (HCT116) and breast cancer (MCF7) cell line was monitored. The highest inhibition was observed using diethyl ether crude extract (DEE) recording between 12.5 and 19.5 mm inhibition zone against all tested bacteria and between 8.7 and 18.3 mm against tested fungi. The highest anticancer effect of DEE was observed at IC50 against HCT116 and HepG2 cell lines using just 24.6 and 42.8 µg ml-1, respectively. While, high concentration, 93.8 µg ml-1, was required to exhibit its effect against MCF7. Column chromatography technique was used to separate DEE crude extract to its main components using 7 different mobile phases. Fractions F1 and F7 were the highest fractions that had antimicrobial activity against tested bacteria and fungi. High IC50 > 80 µg ml-1 were required to exhibit anticancer activity at IC50 against the tested cancer cell lines. The main compounds responsible for the bioactivity were identified using GC-MS, nonadecane and butylated hydroxytoluene in F1 and 9-octadecadienoic acid and quercetin 7,3',4'-trimethoxy in F7 were identified. The current study highlights the potential use of S. Obliquus extract and their fractions as a source of antimicrobial and anticancer compounds.

Activation of mGluR1 Mediates C1q-Dependent Microglial Phagocytosis of Glutamatergic Synapses in Alzheimer's Rodent Models.

Microglia and complements appear to be involved in the synaptic and cognitive deficits in Alzheimer's disease (AD), though the mechanisms remain elusive. In this study, utilizing two types of rodent model of AD, we reported increased complement C1q-mediated microglial phagocytosis of hippocampal glutamatergic synapses, which led to synaptic and cognitive deficits. We also found increased activity of the metabotropic glutamate receptor 1 (mGluR1) in hippocampal CA1 in the modeled rodents. Artificial activation of mGluR1 signaling promoted dephosphorylation of fragile X mental retardation protein (FMRP) and facilitated the local translation machinery of synaptic C1q mRNA, thus mimicking the C1q-mediated microglial phagocytosis of hippocampal glutamatergic synapses and synaptic and cognitive deficiency in the modeled rodents. However, suppression of mGluR1 signaling inhibited the dephosphorylation of FMRP and repressed the local translation of synaptic C1q mRNA, which consequently alleviated microglial phagocytosis of synapses and restored the synaptic and cognitive function in the rodent models. These findings illustrate a novel molecular mechanism underlying C1q-mediated microglial phagocytosis of hippocampal glutamatergic synapses in AD.

Cannabinoid Type 2 Receptor System Modulates Paclitaxel-Induced Microglial Dysregulation and Central Sensitization in Rats.

Paclitaxel induces microglial activation and production of proinflammatory mediators in the dorsal horn, which contribute to the development and maintenance of central sensitization and pain behavior. MDA7, 1-([3-benzyl-3-methyl-2,3-dihydro-1-benzofuran-6-yl]carbonyl) piperidine, is a novel highly selective cannabinoid type 2 (CB2) agonist. We tested the hypothesis that activation of CB2 receptor by MDA7 modulates microglial dysregulation, suppresses the overexpression of brain-derived neurotrophic factor (BDNF) in microglia in the dorsal horn, and attenuates the central sensitization and pain behavior induced by paclitaxel. For 4 consecutice days, groups of rats randomly received saline or 1.0 mg/kg of paclitaxel daily intraperitoneally for a total cumulative dose of 4 mg/kg. MDA7 15 mg/kg intraperitoneally or vehicle were administered 15 min before administering paclitaxel for 4 days and then continued for another 10 days. Behavioral and molecular studies were performed. Paclitaxel induced the expression of CB2 receptors and production of interleukin (IL)-6 in microglia in the dorsal horn. MDA7 attenuated the expression of IL-6 and promoted the expression of IL-10. Paclitaxel induced epigenetic upregulation of IRF8 and P2X purinoceptor 4 (P2X4) in microglia and subsequently increased the expression of alpha isoform of calcium/calmodulin-dependent protein kinase II (CaMKIIα), transcriptional factors p-CREB and ΔFosB, leading to the overproduction of BDNF in microglia. Paclitaxel also upregulated the expression of glutamate receptor subunits GluR1 and NR2B, decreased the expression of K+-Cl- cotransporter, and induced mechanical allodynia in rats. All of the aforementioned molecular changes were attenuated by MDA7. Our data show that MDA7 attenuated paclitaxel-induced molecular and behavioral changes in rats. Perspective: This study provides evidence that paclitaxel induced microglia dysregulation and epigenetically upregulated the microglial expression of BDNF, which led to sensitization of dorsal horn neurons and mechanical allodynia in rats. The CB2 agonist MDA7 alleviated these pathological processes. MDA7 represents an innovative therapeutic approach for treatment of chemotherapy-induced neuropathy.

An overview of the cannabinoid type 2 receptor system and its therapeutic potential.

PURPOSE OF REVIEW: This narrative review summarizes recent insights into the role of the cannabinoid type 2 (CB2) receptor as potential therapeutic target in neuropathic pain and neurodegenerative conditions. RECENT FINDINGS: The cannabinoid system continues to receive attention as a therapeutic target. The CB2 receptor is primarily expressed on glial cells only when there is active inflammation and appears to be devoid of undesired psychotropic effects or addiction liability. The CB2 receptor has been shown to have potential as a therapeutic target in models of diseases with limited or no currently approved therapies, such as neuropathic pain and neurodegenerative conditions such as Alzheimer's disease. SUMMARY: The functional involvement of CB2 receptor in neuropathic pain and other neuroinflammatory diseases highlights the potential therapeutic role of drugs acting at the CB2 receptor.

Amyloid fibrils induce dysfunction of hippocampal glutamatergic silent synapses.

Silent glutamatergic synapses lacking functional AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionate) receptors exist in several brain regions including the hippocampus. Their involvement in the dysfunction of hippocampal glutamatergic transmission in the setting of Alzheimer's disease (AD) is unknown. This study demonstrated a decrease in the percentage of silent synapses in rats microinjected with amyloid fibrils (Aß1-40 ) into the hippocampal CA1. Also, pairing low-frequency electric stimuli failed to induce activation of the hippocampal silent synapses in the modeled rats. Immunoblotting studies revealed a decreased expression of GluR1 subunits in the hippocampal CA1 synaptosomal preparation, indicating a potential reduction in the GluR1 subunits anchoring in postsynaptic density in the modeled rats. We also noted a decreased expression of phosphorylated cofilin, which regulates the function of actin cytoskeleton and receptor trafficking, and reduced expression of the scaffolding protein PSD95 in the hippocampal CA1 synaptosome in rats injected with Aß1-40 . Taken together, this study illustrates dysfunction of hippocampal silent synapse in the rodent model of AD, which might result from the impairments of actin cytoskeleton and postsynaptic scaffolding proteins induced by amyloid fibrils.

Rapid, Regioselective Living Ring-Opening Metathesis Polymerization of Bio-Derivable Asymmetric Tricyclic Oxanorbornenes.

The synthesis of a range of alkyl esters (methyl, n-butyl, and n-decyl) prepared via Steglich esterification of the thermodynamically controlled exo, exo Diels-Alder adduct of furfuryl alcohol and maleic anhydride is reported. Subsequent ring-opening metathesis polymerization of these bio-derivable tricyclic oxanorbornene analogs delivers polymers with targeted molar mass and low molar mass dispersity. The polymerizations are rapid with complete monomer conversion achieved within 15 min. Significantly, the presence of the cyclic lactone at the bridgehead of these monomers leads to polymers with high regioregularity (>85% head-to-tail) and high stereoregularity (>75% trans). The resultant polymers display both high thermal stability and high glass transition temperatures. This new class of oxanorbornene monomer, accessed from bio-derivable furfuryl alcohol and maleic anhydride, may be further tailored to incorporate a range of functional moieties. Furthermore, the exceptional properties of the derived polymers indicate potential in a range of applications.

Consensus Statement on Perioperative Use of Neuromuscular Monitoring.

A panel of clinician scientists with expertise in neuromuscular blockade (NMB) monitoring was convened with a charge to prepare a consensus statement on indications for and proper use of such monitors. The aims of this article are to: (a) provide the rationale and scientific basis for the use of quantitative NMB monitoring; (b) offer a set of recommendations for quantitative NMB monitoring standards; (c) specify educational goals; and (d) propose training recommendations to ensure proper neuromuscular monitoring and management. The panel believes that whenever a neuromuscular blocker is administered, neuromuscular function must be monitored by observing the evoked muscular response to peripheral nerve stimulation. Ideally, this should be done at the hand muscles (not the facial muscles) with a quantitative (objective) monitor. Objective monitoring (documentation of train-of-four ratio ≥0.90) is the only method of assuring that satisfactory recovery of neuromuscular function has taken place. The panel also recommends that subjective evaluation of the responses to train-of-four stimulation (when using a peripheral nerve stimulator) or clinical tests of recovery from NMB (such as the 5-second head lift) should be abandoned in favor of objective monitoring. During an interim period for establishing these recommendations, if only a peripheral nerve stimulator is available, its use should be mandatory in any patient receiving a neuromuscular blocking drug. The panel acknowledges that publishing this statement per se will not result in its spontaneous acceptance, adherence to its recommendations, or change in routine practice. Implementation of objective monitoring will likely require professional societies and anesthesia department leadership to champion its use to change anesthesia practitioner behavior.