Inhibition Mechanism of Cholinesterases by Carbamate: A Theoretical Study

The density functional theory at the B3LYP/6-311G（d, p） level was applied to exploring the inhibition mechanism of cholinesterases by carbamate. The results indicate that the inhibition reactions with or without the catalytic effect of the catalytic triad in eholinesterases underwent a two-step addition-elimination mechanism, which is in good agreement with the proposed mechanism. The solvent has a strong effect on the inhibition reactions and the reaction with the catalytic triad in the solvent phase is close to the real reaction under biological condition.

Purification and studies on characteristics of cholinesterases from Daphnia magna

Due to their significant value in both economy and ecology,Daphnia had long been employed to investigate in vivo response of cholinesterase(ChE) in anticholinesterase exposures,whereas the type constitution and property of the enzyme remained unclear.A type of ChE was purified from Daphnia magna using a three-step procedure,i.e.,Triton X-100 extraction,ammonium sulfate precipitation,and diethylaminoethyl(DEAE)-Sepharose Fast-Flow chromatography.According to sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE),molecular mass of the purified ChE was estimated to be 84 kDa.Based on substrate studies,the purified enzyme preferred butyrylthiocholine iodide(BTCh) [with maximum velocity(Vmax)/Michaelis constant(Km)=8.428 L/(min·mg protein)] to acetylthiocholine iodide(ATCh) [with V max /Km =5.346 L/(min·mg protein)] as its substrate.Activity of the purified enzyme was suppressed by high concentrations of either ATCh or BTCh.Inhibitor studies showed that the purified enzyme was more sensitive towards inhibition by tetraisopropylpyrophosphoramide(iso-OMPA) than by 1,5-bis(4-allyldimethylammoniumphenyl) pentan-3-one dibromide(BW284C51).Result of the study suggested that the purified ChE was more like a type of pseudocholinesterase,and it also suggested that Daphnia magna contained multiple types of ChE in their bodies.

Ameliorating Effects of Thyroxine and Atropine in Phosphamidon Intoxicated Chick Embryos

The effects of thyroxine and atropine in ameliorating phosphamidon intoxication in chick embryos was studied. Treatment of phosphamidon significantly enhanced the moriality and abnormalityrates, decreased the average body weights, and cholinesterase activity in chick embryos. When thyroxine was administered to the phosphamidon intoxicated embryos, the above parameters changedsignificantly, indicating an ameliorating effect of thyroxine against phosphamidon intoxication in chick embryos. The combined thyroxine and atropine therapy did not further improve the ameliorating effect. Since in many respects chick embryo development parallels that of mammalian embryos,a short-term use of thyroxine as a protective agent against organophosphate toxicity might be useful

Acetylcholinesterase,butyrylcholinesterase and paraoxonase 1 activities in rats treated with cannabis,tramadol or both

Objective:To investigate the effect of Cannabis sativa resin and/or tramadol,two commonly drugs of abuse on acetylcholinesterase and butyrylcholinesterase activities as a possible cholinergic biomarkers of neurotoxicity induced by these agents.Methods:rats were treated with cannabis resin(5,10 or 20 mg/kg)(equivalent to the active constituent A'-tetrahydrocannabinol),tramadol(5,10 and 20 mg/kg) or tramadol(10 mg/kg)combined with cannabis resin(5,10 and 20 mg/kg) subcutaneously daily for 6 weeks.Acetylcholinesterase(AChE) and butyrylcholinesterase(BChE) activities were measured in brain and serum.We also measured the activity of paraoxonase-1(PONl) in serum of rats treated with these agents.Results:(i) AChE activity in brain increased after 10-20 mg/kg cannabis resin(by 16.3%-36.5%).AChE activity in brain did not change after treatment with 5-20 mg/kg tramadol.The administration of both cannabis resin(5,10 or 20 mg/kg) and tramadol(10 mg/kg) resulted in decreased brain AChE activity by 14.1%,12.9%and 13.6%,respectively;(ii) BChE activity in serum was markedly and dose-dependenlly inhibited by cannabis resin(by 60.9%-76.9%).BChE activity also decreased by 17.6%-36.5%by 10-20mg/kg tramadol and by 57.2%-63.9%by the cannabis resin/tramadol combined treatment;(iii)Cannabis resin at dose of 20 mg/kg increased serum PONl activity by 25.7%.In contrast,tramadol given at 5,10 and 20 mg/kg resulted in a dose-dependent decrease in serum PON1 activity by 19%,36.7%,and 46.1%,respectively.Meanwhile,treatment with cannabis resin plus tramadol resulted in 40.2%,35.8%,30.7%inhibition of PONl activity compared to the saline group.Conclusions:these data suggest that cannabis resin exerts different effects on AChE and BChE activities which could contribute to the memory problems and the decline in cognitive function in chronic users.

Comparative efficacy and safety of cognitive enhancers for treating vascular cognitive impairment: systematic review and Bayesian network meta-analysis

Objective: To assess and compare the clinical efficacy and safety of cognitive enhancers(donepezil, galantamine, rivastigmine, and memantine) on cognition, behavior, function, and global status in patients with vascular cognitive impairment.Data sources: The initial literature search was performed with PubMed, EMBASE, the Cochrane Methodology Register, the Cochrane Central Register of Controlled Trials, and Cumulative Index to Nursing & Allied Health(CINAHL) from inception to January 2018 for studies regarding donepezil, galantamine, rivastigmine, and memantine for treatment of vascular cognitive impairment.Data selection: Randomized controlled trials on donepezil, galantamine, rivastigmine, and memantine as monotherapy in the treatment of vascular cognitive impairment were included. A Bayesian network meta-analysis was conducted. Outcome measures: Efficacy was assessed by changes in scores of the Alzheimer's Disease Assessment Scale, cognitive subscale, Mini-Mental State Examination, Neuropsychiatric Inventory scores and Clinician's Interview-Based Impression of Change Scale Plus Caregiver's Input, Activities of Daily Living, the Clinical Dementia Rating scale. Safety was evaluated by mortality, total adverse events(TAEs), serious adverse events(SAEs), nausea, vomiting. diarrhea, or cerebrovascular accidents(CVAs). Results: After screening 1717 citations, 12 randomized controlled trials were included. Donepezil and rivastigmine(mean difference(e) = –0.77, 95% confidence interval(CI): 0.25–1.32; MD = 1.05, 95% CI: 0.18–1.79) were significantly more effective than placebo in reducing Mini-Mental State Examination scores. Donepezil, galantamine, and memantine(MD = –1.30, 95% CI: –2.27 to –0.42; MD = –1.67, 95% CI: –3.36 to –0.06; MD = –2.27, 95% CI: –3.91 to –0.53) showed superior benefits on the Alzheimer's Disease Assessment Scale–cognitive scores compared with placebo. Memantine(MD = 2.71, 95% CI: 1.05–7.29) improved global status(Clinician's Interview-Based Impression of Change Scale Plus Caregiver's Input) more than the placebo. Safety results revealed that donepezil 10 mg(odds ratio(OR) = 3.04, 95% CI: 1.86–5.41) contributed to higer risk of adverse events than placebo. Galantamine(OR = 5.64, 95% CI: 1.31–26.71) increased the risk of nausea. Rivastigmine(OR = 16.80, 95% CI: 1.78–319.26) increased the risk of vomiting. No agents displayed a significant risk of serious adverse events, mortality, cerebrovascular accidents, or diarrhea.Conclusion: We found significant efficacy of donepezil, galantamine, and memantine on cognition. Memantine can provide significant efficacy in global status. They are all safe and well tolerated.

Serum cholinesterase: A predictive biomarker of hepatic reserves in chronic hepatitis D

To determine the predictive performance of cholinesterase compared to existing prognostic models in evaluating liver function in patients with chronic hepatitis D. METHODSIn an observational, cross-sectional and retrospective study, consecutive patients with hepatitis D cirrhosis were evaluated. Demographic, clinical and laboratory parameters were recorded. Serum cholinesterase levels were correlated with existing scoring models for chronic liver disease and Liver function tests. Receiver operating characteristic (ROC) curves were constructed to find an optimal cholinesterase level predicting ascites, Child Turcotte Pugh (CTP) score ≥ 10, model for end stage liver disease (MELD) score ≥ 15, baseline-event-anticipation (BEA) score for hepatitis D ≥ 5 and the aspartate transaminase to Platelet Ratio Index (APRI) ≥ 1.5. RESULTSThis study investigated 233 patients with chronic liver disease due to hepatitis D; 192 were male, median age 42 (16-69 years). Fifty patients had ascites and 15 had encephalopathy. One hundred and sixty-seven (71.7%) were in Child class A, 52 (22.3%) in Child class B and 14 (5.0%) in class C. A MELD score of 15 or more was seen in 24 patients. Cholinesterase levels correlated well with the INR, albumin, CTP score, MELD, MELD sodium, BEA and APRI scores (P < 0.001 each). Area under the ROC curve for ascites, CTP ≥ 10, MELD ≥ 15, BEA ≥ 5, APRI ≥ 1.5 was 0.836, 0.966, 0.913, 0.871 and 0.825 respectively (P < 0.001 each). Cut off values of cholinesterase (IU/L) for predicting ascites, CTP ≥ 10, MELD ≥ 15, BEA ≥ 5 and APRI ≥ 1.5 were < 3812, < 2853, < 2829, < 4719 and < 3954 with a sensitivity of 80%, 100%, 91.67%, 82.50%, 58.0% and specificity of 81.97%, 84.79%, 87.56%, 77.06% and 55.64% respectively. CONCLUSIONSerum cholinesterase demonstrates promising correlations with serum albumin, INR and CTP, MELD, BEA and APRI scores and is predictive of liver reserves in hepatitis D cirrhosis.

Eleutheroside B or E enhances learning and memory in experimentally aged rats

Eleutheroside B or E, the main component of Acanthopanax, can relieve fatigue, enhance memory, and improve human cognition. Numerous studies have confirmed that high doses of acetylcholine significantly attenuate clinical symptoms and delay the progression of Alzheimer＇s disease. The present study replicated a rat model of aging induced by injecting quinolinic acid into the hippocampal CA1 region. These rats were intraperitoneally injected with low, medium and high doses of eleutheroside B or E （50, 100, 200 mg/kg）, and rats injected with Huperzine A or PBS were used as controls. At 4 weeks after administration, behavioral tests showed that the escape latencies and errors in searching for the platform in a Morris water maze were dose-dependently reduced in rats treated with medium and high-dose eleutheroside B or E. Hematoxylin-eosin staining showed that the number of surviving hippocampal neurons was greater and pathological injury was milder in three eleutheroside B or E groups compared with model group. Hippocampal homogenates showed enhanced cholinesterase activity, and dose-dependent increases in acetylcholine content and decreases in choline content following eleutheroside B or E treatment, similar to those seen in the Huperzine A group. These findings indicate that eleutheroside B or E improves learning and memory in aged rats. These effects of eleutheroside B or E may be mediated by activation of cholinesterase or enhanced reuse of choline to accelerate the synthesis of acetylcholine in hippocampal neurons.

Monitoring the level of serum paraoxonase 1 activity in liver transplantation patients

BACKGROUND: Paraoxonase 1(PON1) is an ester hydro- lase in serum and in the liver. Studies have suggested that PON1 measurement to the current battery of tests may im- prove the evaluation of chronic liver diseases. The aim of this study was to investigate the clinical significance of mo- nitoring the level of serum PON1 activity in liver transplan- tation patients. METHODS: A series of biochemical indexes were moni- tored in preoperative, operative and postoperative serum samples of 17 liver-transplanted patients. The change of se- rum PON1 level and its relations with other biochemical in- dexes were analyzed. RESULTS: PON1 was distributed normally in the healthy population and its reference value ranged from 45.5 to 265.8 U/mL. The PON1 level of all patients was lower than that of control group significantly (P<0.001); the level be- gan to elevate continuously 5 minutes after opening of the portal vein and was higher than that 90 minutes after open- ing of the portal vein ( P <0.05). Two days after operation it was still higher than the normal. The levels of serum ALT and AST elevated more significantly after opening of the portal vein than before operation and they were higher than the normal values till 2 days after the operation. CONCLUSIONS: The level of PON1 in serum may be taken as one of the effective indexes to assess whether the implant is alive and to monitor liver function of the patient together with other tests.

Clinical correlates of hypotension in patients with acute organophosphorus poisoning

BACKGROUND:The aim of the present study is to describe the clinical correlates of hypotension and its associated outcomes in patients with acute organophosphorus poisoning(AOPP).METHODS:In this retrospective cohort study,we analyzed data pertaining to 871 patients with AOPP who were treated at two hospitals.Data from hypotensive and non-hypotensive patients were compared to identify clinical correlates of hypotension.We also evaluated the association between clinical parameters(including hypotension)and in-hospital mortality.RESULTS:The incidence of hypotension in AOPP patients was 16.4%.Hypotensive patients showed signifi cantly higher in-hospital mortality(1.1%vs.39.9%,P<0.001).Advanced age(odds ratio[OR]1.25,95%confi dence interval[CI]1.08–1.44),history of diabetes(OR 2.65,95%CI 1.14–5.96),and increased white blood cell count(OR 1.06,95%CI 1.03–1.09),plasma cholinesterase(OR 0.91,95%CI 0.84–0.94),plasma albumin(OR 0.88,95%CI 0.85–0.92),serum amylase(OR 1.01,95%CI 1.01–1.02),and blood pH(OR 0.64,95%CI 0.54–0.75)were signifi cantly associated with hypotension.After adjusting for potential confounders,hypotension was associated with increased in-hospital mortality(hazard ratio 8.77–37.06,depending on the controlled variables).CONCLUSIONS:Hypotension is a common complication of AOPP and is associated with increased in-hospital mortality.Advanced age,history of diabetes,and changes in laboratory parameters were associated with hypotension in AOPP patients.

Alterations of serum cholinesterase in patients with gastric cancer

AIM: To understand the correlation of serum cholinesterase (CHE) activity with gastric cancer and to assess their clinical significance.METHODS: The velocity method was adopted to detect the activity of serum CHE in patients with gastric cancer and in patients with non-malignant tumor as controls.RESULTS: The serum CHE activity in the treatment group was significantly lower than that in the control group with a very significant difference between the two groups (83.3:113.1,P = 0.0003). Age was significantly associated with the incidence of gastric caner.CONCLUSION: Serum CHE activity has a close relation with the incidence of gastric cancer.

Anti-Alzheimer's disease potential of coumarins from Angelica decursiva and Artemisia capillaris and structure-activity analysis

Objective: To use structure-activity analysis to study the anti-Alzheimer's disease(anti-AD) activity of natural coumarins isolated from Angelica decursiva and Artemisia capillaries, along with one purchased coumarin(daphnetin). Methods: Umbelliferone, umbelliferone 6-carboxylic acid, scopoletin, isoscopoletin, 7-methoxy coumarin, scoparone, scopolin, and esculetin have been previously isolated; however 2'-isopropyl psoralene was isolated from Angelica decursiva for the first time to evaluate their inhibitory effects against acetylcholinesterase(ACh E), butyrylcholinesterase(BCh E), and β-site amyloid precursor protein cleaving enzyme 1(BACE1) enzyme activity. We scrutinized the potentials of coumarins as cholinesterase and BACE1 inhibitors via enzyme kinetics and molecular docking simulation. Results: Among the test compounds, umbelliferone 6-carboxylic acid, esculetin and daphnetin exhibited potent inhibitory activity against ACh E, BCh E and BACE1. Both esculetin and daphnetin have a catechol group and exhibit significant anti-AD activity against ACh E and BCh E. In contrast, presence of a sugar moiety and methoxylation markedly reduced the anti-AD activity of the coumarins investigated in this study. With respect to BACE1 inhibition, umbelliferone 6-carboxylic acid, esculetin and daphnetin contained carboxyl or catechol groups, which significantly contributed to their antiAD activities. To further investigate these results, we generated a 3D structure of BACE1 using Autodock 4.2 and simulated binding of umbelliferone 6-carboxylic acid, esculetin and daphnetin. Docking simulations showed that different residues of BACE1 interacted with hydroxyl and carboxylic groups, and the binding energies of umbelliferone 6-carboxylic acid, esculetin and daphnetin were negative(-4.58,-6.25 and-6.37 kcal/mol respectively). Conclusions: Taken together, our results suggest that umbelliferone 6-carboxylic acid, esculetin and daphnetin have anti-AD effects by inhibiting ACh E, BCh E and BACE1, which might be useful against AD.

Effects of Diazepam on Rat Cholinesterase andMembrane Stability of Red Cell in vitro

The results confirmed that diazepam inhibits the cholinesterase in rat serum,red cell,corpus striatum and diaphragm in vitro,that the higher the diazepam concentration,the stronger the cholinesterase inhibition,and that diazepam is a reversible inhibitor to acetylcholinesterase and diazepam has a stabilizing action on red cell membranes.The role of these effects of diazepam in the treatment of organic phosphate poisoning is discussed

A comparative study on antioxidant potentials,inhibitory activities against key enzymes related to metabolic syndrome,and anti-inflammatory activity of leaf extract from different Momordica species

Momordica species are vegetable crops widely distributed in warmer regions of the world.In this work,we describe the antioxidant,enzyme inhibitory and anti-inflammatory effects of the leaves from three different species of Momordica.The present investigation was initially carried out to explore the possible link between antioxidant,enzyme inhibitory property of Momordica leaf extract and their total phenolic and flavonoid contents.The anti-inflammatory activity was tested by using carrageenan-induced paw edema.Our results illustrated an enhanced antioxidant power of wild species comparable with a commercial variety.In addition,the leaf extract of M.dioica(200 mg/kg)presented a significant anti-inflammatory activity toward carrageenan-induced paw edema in Wistar rats in comparison to indomethacin(10 mg/kg).The contents of flavonoids and total phenolic compounds could be correlated with the antioxidant and enzymes inhibition activities.The major bioactive compounds of phenolic acids and flavonoids such as gallic acid,chlorogenic acid,caffeic acid,ferulic acid,ellagic acid,catechin,rutin,and quercetin were identified.Our findings suggest that wild Momordica species contains higher potential antioxidant and anti-inflammatory activities than a commercial variety does,which could be tested as drug candidates against oxidative and inflammation-related pathological processes.©2014 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Novel neuroprotective and hepatoprorective effects of citric acid in acute malathion intoxication

Objective: To study the effect of citric acid given alone or combined with atropine on brain oxidative stress, neuronal injury, liver damage, and DNA damage of peripheral blood lymphocytes induced in the rat by acute malathion exposure. Methods: Rats were received intraperitoneal(i.p.) injection of malathion 150 mg/kg along with citric acid(200 or 400 mg/kg, orally), atropine(1 mg/kg, i.p.) or citric acid 200 mg/kg+atropine 1 mg/kg and euthanized 4 h later. Results: Malathion resulted in increased lipid peroxidation(malondialdehyde) and nitric oxide concentrations accompanied with a decrease in brain reduced glutathione, glutathione peroxidase(GPx) activity, total antioxidant capacity(TAC) and glucose concentrations. Paraoxonase-1, acetylcholinesterase(ACh E) and butyrylcholinesterase activities decreased in brain as well. Liver aspartate aminotransferase and alanine aminotransferase activities were raised. The Comet assay showed increased DNA damage of peripheral blood lymphocytes. Histological damage and increased expression of inducible nitric oxide synthase(i NOS) were observed in brain and liver. Citric acid resulted in decreased brain lipid peroxidation and nitric oxide. Meanwhile, glutathione, GPx activity, TAC capacity and brain glucose level increased. Brain ACh E increased but PON1 and butyrylcholinesterase activities decreased by citric acid. Liver enzymes, the percentage of damaged blood lymphocytes, histopathological alterations and i NOS expression in brain and liver was decreased by citric acid. Meanwhile, rats treated with atropine showed decreased brain MDA, nitrite but increased GPx activity, TAC, ACh E and glucose. The drug also decreased DNA damage of peripheral blood lymphocytes, histopathological alterations and i NOS expression in brain and liver. Conclusions: The study demonstrates a beneficial effect for citric acid upon brain oxidative stress, neuronal injury, liver and DNA damage due to acute malathion exposure.

Effect of lead acetate toxicity on experimental male albino rat

Objective:To evaluate the effect of different doses of lead acetate(1/20,1/40 and 1/60 of LD_(50))on body weight gain,blood picture,plasma prolein profile and the function of liver,kidney and thyroid gland.Methods:Male albino rats were divided into four groups,the first group represented the health control animals,while the second,third and fourth groups were ingested orally with sub lethal doses of load acetate(1/20,1/40 and 1/60)of the oral LD_(50),respectively.One dose was ingested every two days during the experimental period(14 weeks)including the adaptation time.Blood was collected and used for all analysis.Results:The results showed that,the ingestion of Pb^(2+)induced significant stimulation in glutamic-pyruvic transaminase(ALT)and glutamic-oxalacetic transaminease(AST)activity.Also,total soluble protein and albumin contents of plasma were significantly decreased,while the content of globulin was changed by the Pb^(2+)treatments.The cholinesteiase activity was inhibited,but the activities of alkaline and acid phosphates and lactate dehydrogenase were stimulated,while plasma glucose level was elevated as a result of lead acetate intoxication.In case of blood picture,Pb^(2+)ingestion reduced the contents of hemoglobin and RBCs count of intoxicated rat's blood and the plasma levels of T3,T4 and blood WBCs count were decreased.Conclusions:It can be concluded that lead acetate has harmful effect on experimental male albino rats.Therefore,the present work advises people to prevent exposure to the lead compound to avoid injurious hazard risk.

Novel Quartz Crystal Microbalance Biosensor for Determination of Organophosphorous Dichlorvos

A novel quartz crystal microbalance (QCM) biosensor for the determination of organophosphorus pesticide,such as dichlorvos (DDVP),has been fabricated with poly (3,4-ethylenedioxythiophene)/Poly (4-styrenesulfonate) (PEDOT/PSS) and cholinesterase butyl (BuChE).It is found that PEDOT/PSS coated sensor exhibits the highest sensitivity for DDVP among PEDOT,polyvinyl pyrrolidone,polyvinyl alcohol and polyacrylic acid sensor series.The conditions to prepare PEDOT/PSS coated sensor are optimized.The sensitivity of the PEDOT/PSS hiosensor with BuChE is higher than the others without BuChE The determination of dichlorvos in the range from 400μg/g to 2400μg/g used PEDOT/PSS with BuChE coated hiosensor was obtained.

Stimulation by nizatidine,a histamine H_2-receptor antagonist,of duodenal HCO_3^-secretion in rats:relation to anti-cholinesterase activity

AIM To examine whether nizatidine stimulates duodenal HCO_3^- secretion in rats by inhibiting AChE activity. METHODS Under pentobarbital anesthesia,a proximal duodenal loop was perfused with saline,and the HCO_3 secretion was measured at pH 7.0 using a pH-stat method and by adding 10mM HCI.Nizatidine,neostigmine,carbachol or famotidine was administered i.v.as a single injection. RESULTS Intravenous administration of nizatidine(3-30 mg/kg)dose-dependently increased duodenal HCO_3^- secretion,and the effect at 10mg/kg was equivalent to that obtained by carbachol at 0.01 mg/kg.This nizatidine action was observed at the same dose range that inhibited acid secretion and enhanced gastric motility,mimicked by i.v.injection of neostigmine(0.03 mg/kg),and significantly attenuated by bilateral vagotomy and prior s.c. administration of atropine but not by indomethacin,a cyclooxygenase inhibitor,or N^G-nitro-L-arginine methyl ester,a NO synthase inhibitor.The HCO_3^- secretory response to acetylcholine(0.001 mg/kg)was significantly potentiated by the concurrent administration of nizatidine(3mg/kg,i.v.).The IC_(50)of nizatidine for AChE of rat erythrocytes was 1.4×10^(-6)M,about 12 times higher than that of neostigmine.Neither famotidine(>10^(-3)M, 30mg/kg,i.v.)nor cisapride(> 10^(-3)M, 3mg/kg,i.v.)had any influence on AChE activity or duodenal HCO_3^- secretion.Duodenal damage induced by acid perfusion(100 mM HCI for 4 h)in the presence of indomethacin was significantly prevented by nizatidine and neostigmine,at the doses that increased the HCO_3^- secretion. CONCLUSION Nizatidine stimulates duodenal HCO_3^- secretion,in both vagal-dependent and atropine-sensitive manners,and the action is associated with the anti-AChE activity of this agent.

A Case of Alzheimer’s Disease Was Kept Relative Stable with Sequential Therapy for Eight Years

Background: Although Alzheimer’s disease (AD) has been intensively investigated for many years, the effective treatments are largely missing. Commonly used conventional therapy, such as cholinesterase inhibitors (ChEI) and N-methyl D-asparate receptor antagonist, have been generally considered as having symptom-relieving rather than disease-modifying effects. Thus, how to improve cognitive function beyond such effect & time limitations has become a serious challenge. Aim: In order to solve this challenge, a sequential therapy with the integration of conventional therapy and herbal therapy was applied to AD patients. Careful clinical observation was conducted in our outpatient setting. Case Presentation: A case of probable AD received the sequential therapy has achieved relative stable cognition and overall status in eight years. Conclusion: During the treatment of this AD case in eight years, sequential therapy showed great potential in stabilizing and improving cognition and overall status. Well designed preclinical and clinical studies are needed to investigate the efficacy of sequential therapy for AD and other type of dementia.

Bis(7)-Tacrine, a Promising Anti-Alzheimer's Agent,Attenuates Glutamate-Induced Cell Injury in Primary Cultured Cerebrocortical Neurons of Rats

The effects of bis(7) tacrine, a novel dimeric acetylcholinesterase (AChE) inhibitor, on glutamate induced cell injury were investigated in primary cerebral cortical neurons of rats. Exposure of cultured neurons (12 days after plating) to 0.5 mmol/L glutamate for 30 min resulted in significant cell damage. Pretreatment with bis(7) tacrine (0.03 1.0 μmol/L) reduced the glutamate induced neurotoxicity in a concentration dependent manner and the maximal response was seen at 1 μmol/L with approximately 30% protection. A receptor binding assay showed that bis(7) tacrine can completely displace MK 801 binding to rat cortical membrane with an IC 50 of 0.57 μmol/L. These findings suggest that bis(7) tacrine can directly interact with N methyl D aspartate receptor channel complex, which may contribute to the inhibitor's protective effects against glutamate induced excitotoxicity. Thus, it is possible that anti glutamate/anti AChE synergism is responsible for potentially better Alzheimer's therapy of bis(7) tacrine relative to tacrine.

Morbidity and Mortality Indicators in Acute Organophosphate Poisoning in Zagazig University Hospital, Egypt: Retrospective Study

Introduction: Organ phosphorus (OP) toxicity has been studied extensively because of its world wide use. Toxicity of organophosphates is the result of inhibition of acetyl cholinesterase resulting in cholinergic signs. Aim of the Work: To evaluate initial indicators that can indicate prognosis of patients in OP poisoning. Materials and Methods: A retrospective study conducted in Zagazig university hospital over a year. OP poisoning was clinically diagnosed with history of OP compound exposure and confirmed by low pseudo cholinesterase levels. Results: In the present study, 76 patients were enrolled. Major cases were male. High mortality rates were in the youth and in prolonged ventilated patients. The mortality rate was proportionally related to lag time after exposure and plasma pseudo cholinesterase levels. Electrolyte disturbance did not affect clinical outcome. Conclusion: From this study, it could be concluded that mortality is directly proportionate to the lag time, amount of OP consumed, clinical severity, pseudo cholinesterase levels and duration of ventilator support. This study helps in rapid diagnosis, and rapid early and effective treatment, which may result in decreasing the morbidity and mortality rates. Recommendation: It is recommended to increase awareness regarding the rapid diagnosis, and rapid effective treatment of organ phosphorous.