Posttraumatic Stress Disorder (PTSD) is a psychiatric condition that can develop following exposure to a traumatic event involving actual or threatened death or serious injury. Responses include intense fear, helplessness or horror. Symptoms are characterised into clusters, described as re-experiencing, avoidance, and arousal. These symptoms, which are also evident in other conditions, have been associated with dysfunctions in the central acetylcholinergic system. Benefits from administering acetylcholinesterase inhibitors (AChEI) to people suffering these symptoms have been demonstrated. Donepezil hydrochloride, a reversible inhibitor of the enzyme acetylcholinesterase, is used in the treatment of conditions with difficulties in cognitive function, but has not been used in PTSD. The aim of this thesis was to determine (1) whether there was a difference in the ACh system in people with PTSD and (2) whether administration of an AChEI would change the symtomatology. IDEX (I¹ ² ³ iododexetimide) has been useful in imaging muscarinic-ACh receptors using Single Photon Emission Computerised Tomography (SPECT) and was utilised to investigate whether cholinergic activity in PTSD is altered. One hundred and sixty eight potential subjects were screened and eleven PTSD subjects were enrolled in the IDEX SPECT study. Three healthy non-PTSD control subjects also completed the study. Due to technical complications only the data obtained from eight PTSD and two control subjects was available for analysis. Imaging data for 2 further healthy non-PTSD control subjects were obtained from another study. Sixteen subjects were enrolled in the donepezil open label study (assessed at baseline, Week 2, 6 and 10). Nine PTSD subjects completed the 10-week trial and seven withdrew prematurely (at or after Week 2) due to side effects or a worsening of PTSD symptoms. For the IDEX SPECT study, a voxel-by-voxel statistical analysis of the PTSD subject group versus the control group showed both areas of reduced and increased IDEX uptake. Significant clusters in the PTSD group with a reduced IDEX uptake centred around the bilateral hippocampus, left insula and right precuneus, while increased IDEX uptake appeared in the caudate head. For the donepezil study, in the per-protocol analysis (including only the 9 subjects that completed the protocol), all psychological assessments revealed a difference between the totals obtained at the Week 10 visit compared to those at the Baseline visit and the improvement was in the order of 51%. The intention-to-treat analysis (including all 16 subjects), a repeated measures Analysis of Variance (ANOVA) with a mixed models approach showed that all psychological measures demonstrated statistically significant benefits of the treatment. All subjects who completed the protocol recounted considerable improvement in their overall PTSD symptom profile, which covered symptoms in each of the three clusters. The results of the IDEX SPECT study suggest that alterations in ACh binding in PTSD are evident and may begin to explain a part of the altered cognitive symptomatology apparent in this condition. The pilot open label donepezil trial provided some preliminary evidence that treatment with an AChEI can lessen the intrusions and distress associated with traumatic memories in people with PTSD. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1374974 / Thesis (M.Med.Sc.) -- University of Adelaide, School of Medicine, 2009

Acetylcholinesterase (AChE) effectively hydrolyzes acetylcholine (ACh). The inhibition of AChE is generally lethal and mice without AChE in all tissues (AChE KO) have severe impairments. In the brain, AChE is anchored in the plasma membrane by proline-rich membrane anchor (PRiMA), while in the muscles, AChE is anchored by collagen Q (ColQ) in the basal lamina. We report here that the PRiMA KO mice, in which AChE is essentially eliminated in the brain, show very little changes in behavior despite an excess of ACh in the brain and adaptation of ACh receptors comparable to those seen in AChE KO mice. Moreover, when AChE cannot interact with ColQ and PRiMA, the phenotype resembles that of AChE KO mice, but the biochemical changes in the brain are similar to those in PRiMA KO mice. PRiMA KO mice also differ from other AChE-deficit mice strains in their responses to AChE inhibitor. Our results suggest that AChE in the peripheral tissues is the major target of AChE inhibitors and AChE absence in the peripheral tissues is the leading cause of the phenotype of AChE KO mice.

O uso de fungos na biotransformação estereosseletiva de fármacos pode constituirse em uma excelente alternativa à síntese assimétrica para obtenção de metabólitos, bem como aos estudos de biotransformação in vivo e in vitro convencionais. Neste trabalho foram empregados fungos isolados de órgãos internos de plantas, classificados como endofíticos, fungos fitopatógenos, bem como, fungos adquiridos de coleções de micro-organismos. Esses fungos foram empregados no estudo da biotransformação estereosseletiva dos fármacos midodrina, bufuralol e donepezila. Estes fármacos foram selecionados por produzirem metabólitos ativos nos processos de biotransformação em humanos. Para o monitoramento da formação dos metabólitos dos fármacos foi necessário desenvolver e validar métodos analíticos com características adequadas para essa aplicação. Para determinação enantiosseletiva da midodrina e seu metabólito empregou-se a eletroforese capilar, enquanto que para a determinação aquiral empregou-se a cromatografia líquida de alta eficiência. Para avaliar a biotransformação estereosseletiva do bufuralol e donepezila foram desenvolvidos métodos empregando a cromatografia líquida de alta eficiência. Os dados referentes ao estudo de cada fármaco são apresentados em quatro capítulos. O primeiro capítulo apresenta os resultados obtidos no desenvolvimento de um método empregando a eletroforese capilar para a determinação enantiosseletiva de midodrina e seu metabólito desglimidodrina (DMAE) em meio de cultura Czapek. As análises foram realizadas em capilar de sílica de 50 ?m de diâmetro interno e com comprimento efetivo de 40 cm, utilizando 30 mmol L-1 de trimetil- -ciclodextrina dissolvida em solução de acetato de sódio 70 mmol L-1, pH 5, como tampão de análise. A técnica de preparação das amostras empregada foi a extração líquidolíquido. O método foi validado, mostrando linearidade na faixa de concentração de 100 - 12000 ng mL-1, com coeficientes de correlação linear 0.9975. Os resultados de precisão e exatidão foram inferiores a 15% e a robustez do método foi avaliada através de um planejamento fatorial fracionário. O método foi aplicado em um estudo de biotransformação usando fungos endofíticos. Foram avaliados oito fungos com destaque para o fungo Papulaspora immersa Hotson (SS13) que biotransformou 21,3% da (+)-midodrina em (+)-DMAE e 2,4% da (-)-midodrina em (-)-DMAE, em 72 h de biotransformação, apresentando um excesso enantiomérico de 79,7%. O segundo capítulo apresenta os resultados obtidos no desenvolvimento de um método cromatográfico para a determinação de midodrina e DMAE em meio de cultura Czapek-Dox. As análises foram realizadas no modo reverso de eluição empregando uma coluna Lichrospher 100 RP 18 e fase móvel composta por acetonitrila:ácido fórmico 40 mmol L-1 (60:40, v/v), vazão de 1,4 mL min-1 e detecção em 290 nm. O preparo de amostras empregado foi a extração líquido-líquido, usando acetato de etila como solvente extrator. O método foi validado na faixa de concentração de 0,4 a 40 ?g mL-1, com coeficientes de correlação linear superiores ii a 0,9997. Este método foi aplicado em um estudo de biotransformação da midodrina empregando o fungo endofítico Papulaspora immersa e duas linhagens do fitopatógeno Botrytis cinerea (UCA 992 e 2100). Entre os fungos estudados, o Botrytis cinerea 2100, em condição de agitação, apresentou o maior percentual de biotransformação da midodrina em DMAE (42,2% em 48 h). Além disso, nos cromatogramas referentes a biotransformação em condição estática, pelos fungos Papulaspora immersa e Botrytis cinerea 2100, foi observada a presença de picos adicionais não observados nos controles realizados. Estes fungos foram submetidos à biotransformação em escala ampliada, em condição estática, a partir das quais foram isolados DMAE de ambos os fungos e um derivado desaminado da midodrina (Botrytis cinerea 2100). No terceiro capítulo são apresentados os resultados obtidos com o desenvolvimento de um método para a determinação estereosseletiva do bufuralol e seus metabólitos 1'-oxobufuralol e 1'-hidroxibufuralol em meio Czapek, usando a coluna Chiralcel OD-H no modo normal de eluição. As demais condições cromatográficas empregadas foram: fase móvel constituída por hexano:isopropanol:metanol (97,5:2,0:0,5; v/v/v) acrescidos de 0,5% de dietilamina, vazão 1,5 mL min-1 e detecção no UV em 248 e 273 nm. A microextração em fase líquida com membrana cilíndrica oca em três fases foi usada como procedimento de preparação das amostras. As condições empregadas na extração foram: fase doadora em pH 13 ajustado com NaOH 2 mol L-1, n-octanol como solvente orgânico, fase aceptora constituída por ácido acético 0,2 mol L-1, tempo de extração de 30 min e velocidade de agitação de 1750 rpm. Os valores de recuperação do método ficaram na faixa de 50 - 69%. O método foi aplicado em um estudo piloto de biotransformação com cinco espécies de fungos endofíticos. Nenhum dos fungos estudados biotransformou o bufuralol em 1'-oxobufuralol e/ou 1'-hidroxibufuralol e, devido a isso, o método desenvolvido não foi validado. O quarto capítulo mostra os resultados obtidos com o desenvolvimento de um método empregando a cromatografia líquida de alta eficiência na determinação enantiosseletiva da donepezila, 5-O-desmetil donepezila e 6-O-desmetil donepezila em meio de cultura Czapek. As análises foram realizadas na coluna Chiralpak AD-H no modo normal de eluição. As demais condições cromatográficas empregadas foram: fase móvel constituída por hexano:etanol:metanol (75:20:5, v/v/v) acrescido de 0,3% de trietilamina, vazão 1,5 mL min-1 e detecção no UV em 270 nm. A técnica de preparação das amostras foi a extração líquido-líquido e o solvente extrator foi o acetato de etila. O método descrito foi validado, mostrando linearidade na faixa de concentração de 100 - 10000 ng mL-1 para os enantiômeros da donepezila (r 0,9985) e 100 - 5000 ng mL-1 para os enantiômeros da 5-O-desmetil donepezila e 6- O-desmetil donepezila (r 0,9951). Os valores de recuperação foram superiores a 90% para todos os analitos. O método foi aplicado em um estudo de biotransformação usando fungos. Foram avaliados cinco fungos endofíticos e os fungos Cunninghamella elegans ATCC 10028B e Beauveria bassiana ATCC 7159. Os fungos endofíticos não desmetilaram a donepezila nas condições estudadas, entretanto, esta reação foi catalisada pelo fungo B. bassiana que biotransformou predominantemente 8,3% da donepezila em (-)-(R)-5-O-desmetil donepezila (ee, 60,6%), enquanto que o fungo C. elegans apresentou biotransformação enantiosseletiva da donepezila em (-)-(R)-6-O-desmetil donepezila (ee, 100%) com um rendimento de 15,1%. Os dados aqui apresentados demonstram que biotransformações com fungos são uma importante alternativa para mimetizar a biotransformação em mamíferos e para a obtenção de metabólitos de fármacos, especialmente na forma de enantiômeros puros. / Drug biotransformations using fungi are considered an alternative approach to the asymmetric synthesis and conventional in vivo and in vitro metabolism studies. In this work, endophytic fungi isolated from health internal plant organs, phythophatogenic fungi and fungi purchased from ATCC were used to study the stereoselective biotransformation of midodrine, bufuralol and donepezil drugs. These drugs were selected because the biotrasformation process in humans results in active metabolites. To evaluate the metabolite formation during the biotransformation study, suitable analytical methods were required. The midodrine biotransformation was evaluated under chiral and achiral conditions. For the enantiosselective determination of midodrine, a capillary electrophoresis method was used, whereas the achiral determination of this drug and its metabolite was carried out by liquid chromatography. The determination of the other drugs was performed by chiral liquid chromatography.The results of each studied drug are presented in four chapters. In the first chapter, a capillary electrophoresis method was described for the stereoselective determination of midodrine and desglymidodrine (DMAE) in Czapek culture medium to be applied to a stereoselective biotransformation study employing endophytic fungi. The electrophoretic analyses were performed using an uncoated fused-silica capillary and 70 mmol L-1 sodium acetate buffer solution (pH 5.0) containing 30 mmol L-1 heptakis (2, 3, 6-tri-O-methyl)--CD as running electrolyte. The applied voltage and temperature used were 15 kV and 15°C, respectively. The UV detector was set at 200 nm. The sample preparation was carried out by liquid- liquid extraction using ethyl acetate as extractor solvent. The method was linear over the concentration range of 100 -12000 ng mL-1 for each enantiomer of midodrine and DMAE (r 0.9975). Within-day and between-day precision and accuracy evaluated by RSDs and relative errors, respectively, were lower than 15% for all analytes. The method proved to be robust by a fractional factorial design evaluation. The validated method was used to assess the midodrine biotransformation to DMAE by eight endophytic fungi. The fungus Papulaspora immersa (SS13) showed the best biotransformation results. It biotransformed 21.3% of (+)-midodrine to (+)-DMAE and 2.4% of (-)-midodrine to (-)-DMAE, after 72 hours. The observed enantiomeric excess was 79.7%. The second chapter describes the optimization and validation of a method for the determination of midodrine and DMAE in Czapek-Dox culture medium. The analyses were carried out under reverse elution mode using a Lichrospher 100 RP 18 column and acetonitrile: formic acid solution 40 mmol L-1 (60:40, v/v), as mobile phase, at a flow rate of 1.4 mL min-1 and UV detection at 290 nm. The sample preparation was carried out by liquid-liquid extraction using ethyl acetate as extractor solvent. The method was linear over the concentration range of 0.4 - 40 ?g mL-1 for each analyte (r 0.9997). This method was applied to evaluate the biotransformation of midodrine by the endophyte Papulaspora immersa and two Botrytis cinerea strains (UCA 992 and 2100). Among the studied fungi, Botrytis v cinerea 2100, at shaken condition, showed the higher percentual of DMAE formation (42.2%, at 48 hours). Moreover, the chromatograms obtained for the biotransformation under static condition, showed additional peaks not detected at performed controls, for both Papulaspora immersa and Botrytis cinerea 2100. Further biotransformation experiments were carried out at large scale on static condition. In addition to DMAE, a deaminated midodrine derivative was isolated from Botrytis cinerea 2100. In the third chapter, a three-phase hollow-fiber liquid-phase microextraction (HF-LPME) method was used for the sample preparation of bufuralol and its metabolites 1'-oxobufuralol and 1'- hydroxybufuralol in Czapek culture medium. The analysis was carried out by chiral liquid chromatography using a Chiralcel OD-H column with hexane: isopropanol:methanol (97.5:2.0:0.5, v/v/v) plus 0.5% diethylamine as the mobile phase, and UV detection at 248 and 273 nm. The HF-LPME optimized conditions involved the use of n-octanol as the organic solvent, 0.2 mol L-1 acetic acid as the acceptor phase, donor phase pH adjusted to 13, sample agitation at 1750 rpm and extraction for 30 min. By using this extraction procedure, the recovery rates were in the range of 50-69%. The method was used to assess the biotransformation of bufuralol using five endophytic fungi strains. None of the studied fungi biotransformed bufuralol to 1'-oxobufuralol and / or 1'- hidroxybufuralol and because of this, the method developed was not validated. In the fourth chapter a chiral liquid chromatography method was described for the stereoselective determination of donepezil, 5-O-desmethyl donepezil, and 6-Odesmethyl donepezil in Czapek culture medium to be applied to a stereoselective biotransformation study employing fungi. The analysis was carried out using a Chiralpak AD-H column with hexane:ethanol:methanol (75:20:5, v/v/v) plus 0.3% triethylamine as the mobile phase at a flow rate of 1.5 mL min-1 and UV detection at 270 nm. The sample preparation was carried out by liquid-liquid extraction using ethyl acetate as extractor solvent. The method was linear over the concentration range of 100 -10000 ng mL-1 for each enantiomer of donepezil (r 0.9985) and of 100 - 5000 ng mL-1 for each enantiomer of 5-O-desmethyl donepezil and 6-Odesmethyl donepezil (r 0.9951). Within-day and between-day precision and accuracy evaluated by RSDs and relative errors, respectively, were lower than 15% for all analytes. The recoveries were higher that 90% for all analytes. The validated method was used to assess the donepezil biotransformation by five endophytes and by Cunninghamella elegans ATCC 10028B e Beauveria bassiana ATCC 7159 fungi. The endophytic fungi do not demethylate donepezil at the studied conditions. On the other hand, Beauveria bassiana ATCC 7159 biotransformed 8.3% of donepezil to (-)- (R)-5-O-desmethyl donepezil (ee, 60.6%), while Cunninghamella elegans ATCC 10028B biotransformed 15.1% of donepezil to (-)-(R)-6-O-desmethyl donepezil (ee, 100%). The data presented here show that the biotransformations with fungi are an important alternative to mimetize biotransformations in mammals and to obtain drug metabolites, especially as pure enantiomers.

Alzheimers sjukdom (AS) är den vanligaste demenssjukdomen som primärt drabbar äldre ³ 65 år. Sjukdomsmekanismerna är inte helt klarlagda dock finns det vetenskapligt bevis som visar att β-amyloid och tau-protein har en avgörande roll i uppkomsten av AS, vilket leder successivt till utveckling av nervcellsdegeneration i hjärnan. Vanliga symtom är minnesbesvär, försämrat språk och tidsuppfattning. Idag finns det ingen behandling som botar sjukdomen utan befintliga läkemedel, acetylkolinesterashämmare (indikation mild/måttlig demens) och memantin (indikation medelsvår/svår demens) används endast som symtomlindrande mediciner. Syfte: Avsikten med litteraturstudien var att undersöka effekten av kolinesterashämmare på patienter med indikation svår Alzheimers sjukdom. Olika databaser och artiklar har använts för att få information om AS och svar på min frågeställning. Resultat: Granskade artiklar visar att kolinesterashämmare kan användas med säkerhet och har god effekt på kognitiva förmågan, ADL-funktioner (”activities of daily living”) och globala funktioner för behandling av patienter med ett svårt stadium av Alzheimers sjukdom under minst 6 månader. Donepezil visar bättre effekt på kognitiva förmågan jämfört med galantamin och rivastigmin. Biverkningarnas svårighetsgrad var generellt mild eller måttlig i form av gastrotintinala besvär. Slutsats: Kolinesterashämmare gynnar patienter med en MMSE poäng 4-12 jämfört med placebobehandling. Fler studier krävs för att utvärdera effekten av galantamin och rivastigmin. / Alzheimer’s disease (AD) is the most common dementia disorder that primarily affects older people age ³ 65 years. The disease mechanisms are not entirely understood, but there is some scientific evidence that describes how Β-amyloid and tau protein play an important role in the pathogenesis of AD, which gradually leads to the development of neurodegeneration in the brain. The disease is characterized by cognitive dysfunction and typical symptoms include memory loss, problems with language and behavioral issues. Currently there is no cure for dementia but acetylcholinesterase inhibitors and memantine can temporarily slow down the decline of symptoms.      The purpose of this literature study was to investigate the effect of cholinesterase inhibitors on patients with severe Alzheimer's disease. Different databases and articles have been used to search information about AD and answer to my question. Results: Examined articles showed that cholinesterase inhibitors could be used safely and have some effect on cognitive ability in patients with a severe stage of Alzheimer's disease for at least 6 months. Donepezil gives rise to a better effect on cognitive ability compared to galantamine and rivastigmine. The most common adverse effects were mild or moderate in severity. Conclusion: Cholinesterase inhibitors provide important benefits in patients with an MMSE score of 4-12 compared with placebo treatment. More studies are required to evaluate the effect of galantamine and rivastigmine

No description available.

A doença de Alzheimer (DA) é uma doença neurodegenerativa e a principal causa de demência em idosos. Os mecanismos fisiopatológicos mais envolvidos na DA são: o acúmulo do peptídeo beta amiloide (A?) em agregados extracelulares, e a formação dos emaranhados neurofibrilares (ENF). A Proteína Precursora do Amiloide (APP) é clivada pelas secretases alfa (ADAM10), beta (BACE1) e y (Presenilina 1 [PSEN1]). As plaquetas contêm 95% da APP circulante e possuem toda a maquinaria necessária para estudar perifericamente a APP e suas secretases. A pesquisa de biomarcadores na DA tem como objetivo identificar, em vida, os indicadores do processo patogênico em fluídos corporais e/ou por métodos de imagem cerebral. O objetivo do presente estudo foi investigar proteínas envolvidas no metabolismo da APP em plaquetas de pacientes com DA e o potencial de modificação destas vias pela ação do tratamento com cloridrato de donepezila. Para tanto foram analisadas amostras de 23 pacientes com DA leve ou moderada, avaliados antes e depois de 6 meses de tratamento e 38 indivíduos idosos cognitivamente saudáveis (controles). As variáveis de desfecho estudadas foram: (1) expressão protéica de ADAM10, BACE1 e PSEN1; (2) expressão protéica dos metabólitos secretados da APP de 110 e 130kDa, possibilitando o cálculo da razão de APP (rAPP); e (3) atividade enzimática das APP-secretases ADAM10 e BACE1. Foram utilizados os métodos de western blotting e o fluorimétrico. Encontramos, nos pacientes com DA pré-tratamento, uma diminuição da rAPP em relação aos controles; porém, não identificamos diferenças após seis meses de tratamento. Os níveis de ADAM10 mostraram-se menores em pacientes com DA na avaliação basal quando comparados aos controles, mas também sem modificação com o tratamento, o tratamento mostrou-se associado a uma redução da expressão de BACE1 em pacientes com DA, embora não tenhamos encontrado diferenças entre pacientes e controles na avaliação basal. A expressão de PSEN1 mostrou-se menor nos pacientes com DA pré-tratamento quando comparada aos controles, sem contudo haver alteração em resposta ao tratamento. Quanto à atividade enzimática de ADAM10 e BACE1, não observamos diferenças nos valores pré e pós-tratamento. Nossos achados reforçam a utilidade da utilização de plaquetas como matriz biológica para o estudo do metabolismo da APP em tecidos periféricos e para a investigação de efeitos modificadores da patogenia da DA a partir do tratamento com drogas antidemência / Alzheimer\'s disease (AD) is a neurodegenerative disease and the major cause of dementia in the elderly. The main mechanisms in AD are: extracellular aggregates of beta amyloid peptide (Abeta) and neurofibrillary tangles formation (NFT). Amyloid Precursor Protein (APP) is cleaved by the secretases alfa (ADAM10), beta (BACE1) and ? (Presenilin 1 [PSEN1]). Platelets containing 95% of the circulating APP and possess all the machinery necessary to study peripherically APP and its secretases. The search for biomarkers in AD aims to identify, in life, the pathogenic process indicators in body fluids and/or brain image methods. The aim of this study was to investigate proteins involved in APP metabolism in platelets of AD patients, and the potential modification of these pathways by treatment with Donepezil hydrochloride. Therefore, 23 patients with mild to moderate AD evaluated before and after 6 months treatment and 38 healthy elderly subjects (controls) were analyzed. Outcome variables were: (1) ADAM10, BACE1 and PSEN1 expression; (2) APP secreted metabolites expression (110 and 130kDa), allowing the APP ratio (rAPP) estimate; (3) APP-secretase ADAM10 and BACE1 enzymatic activity. Western blotting and fluorimetric methods were used. We found in AD patients pre-treatment, a decrease of rAPP compared to controls; however, we did not identify differences of this parameter after six months of treatment. The ADAM10 levels were lower in AD patients at baseline when compared to controls, however no differences were observed after treatment. Treatment was associated with a reduction of BACE1 expression in AD patients, although we have not found differences between patients and controls at baseline. PSEN1 expression was lower in pre-treatment AD patients compared to controls. No differences were observed after treatment. Concerning to BACE1 and ADAM10 enzymatic activity, we did not observe differences in pre and post-treatment. Our findings strengthen the use of platelets as a biological matrix for the APP metabolism as well as the modifying effects on AD pathogenicity of antidementia drugs

A doença de Alzheimer (DA) é uma doença neurodegenerativa e a principal causa de demência em idosos. Os mecanismos fisiopatológicos mais envolvidos na DA são: o acúmulo do peptídeo beta amiloide (A?) em agregados extracelulares, e a formação dos emaranhados neurofibrilares (ENF). A Proteína Precursora do Amiloide (APP) é clivada pelas secretases alfa (ADAM10), beta (BACE1) e y (Presenilina 1 [PSEN1]). As plaquetas contêm 95% da APP circulante e possuem toda a maquinaria necessária para estudar perifericamente a APP e suas secretases. A pesquisa de biomarcadores na DA tem como objetivo identificar, em vida, os indicadores do processo patogênico em fluídos corporais e/ou por métodos de imagem cerebral. O objetivo do presente estudo foi investigar proteínas envolvidas no metabolismo da APP em plaquetas de pacientes com DA e o potencial de modificação destas vias pela ação do tratamento com cloridrato de donepezila. Para tanto foram analisadas amostras de 23 pacientes com DA leve ou moderada, avaliados antes e depois de 6 meses de tratamento e 38 indivíduos idosos cognitivamente saudáveis (controles). As variáveis de desfecho estudadas foram: (1) expressão protéica de ADAM10, BACE1 e PSEN1; (2) expressão protéica dos metabólitos secretados da APP de 110 e 130kDa, possibilitando o cálculo da razão de APP (rAPP); e (3) atividade enzimática das APP-secretases ADAM10 e BACE1. Foram utilizados os métodos de western blotting e o fluorimétrico. Encontramos, nos pacientes com DA pré-tratamento, uma diminuição da rAPP em relação aos controles; porém, não identificamos diferenças após seis meses de tratamento. Os níveis de ADAM10 mostraram-se menores em pacientes com DA na avaliação basal quando comparados aos controles, mas também sem modificação com o tratamento, o tratamento mostrou-se associado a uma redução da expressão de BACE1 em pacientes com DA, embora não tenhamos encontrado diferenças entre pacientes e controles na avaliação basal. A expressão de PSEN1 mostrou-se menor nos pacientes com DA pré-tratamento quando comparada aos controles, sem contudo haver alteração em resposta ao tratamento. Quanto à atividade enzimática de ADAM10 e BACE1, não observamos diferenças nos valores pré e pós-tratamento. Nossos achados reforçam a utilidade da utilização de plaquetas como matriz biológica para o estudo do metabolismo da APP em tecidos periféricos e para a investigação de efeitos modificadores da patogenia da DA a partir do tratamento com drogas antidemência / Alzheimer\'s disease (AD) is a neurodegenerative disease and the major cause of dementia in the elderly. The main mechanisms in AD are: extracellular aggregates of beta amyloid peptide (Abeta) and neurofibrillary tangles formation (NFT). Amyloid Precursor Protein (APP) is cleaved by the secretases alfa (ADAM10), beta (BACE1) and ? (Presenilin 1 [PSEN1]). Platelets containing 95% of the circulating APP and possess all the machinery necessary to study peripherically APP and its secretases. The search for biomarkers in AD aims to identify, in life, the pathogenic process indicators in body fluids and/or brain image methods. The aim of this study was to investigate proteins involved in APP metabolism in platelets of AD patients, and the potential modification of these pathways by treatment with Donepezil hydrochloride. Therefore, 23 patients with mild to moderate AD evaluated before and after 6 months treatment and 38 healthy elderly subjects (controls) were analyzed. Outcome variables were: (1) ADAM10, BACE1 and PSEN1 expression; (2) APP secreted metabolites expression (110 and 130kDa), allowing the APP ratio (rAPP) estimate; (3) APP-secretase ADAM10 and BACE1 enzymatic activity. Western blotting and fluorimetric methods were used. We found in AD patients pre-treatment, a decrease of rAPP compared to controls; however, we did not identify differences of this parameter after six months of treatment. The ADAM10 levels were lower in AD patients at baseline when compared to controls, however no differences were observed after treatment. Treatment was associated with a reduction of BACE1 expression in AD patients, although we have not found differences between patients and controls at baseline. PSEN1 expression was lower in pre-treatment AD patients compared to controls. No differences were observed after treatment. Concerning to BACE1 and ADAM10 enzymatic activity, we did not observe differences in pre and post-treatment. Our findings strengthen the use of platelets as a biological matrix for the APP metabolism as well as the modifying effects on AD pathogenicity of antidementia drugs

Les traitements pharmacologiques symptomatiques de la maladie d’Alzheimer (MA) actuellement commercialisés ont un effet modeste sur le fonctionnement cognitif. De plus, le développement clinique de nouveaux composés plus efficaces est freiné par l’absence de critères prédictifs pour juger précocement de leur efficacité clinique.Dans ce contexte, l’électroencéphalographie (EEG) pourrait constituer un bio-marqueur suffisamment sensible pour identifier précocement (Phase I) le potentiel thérapeutique d’une nouvelle molécule sur le fonctionnement cognitif. De plus, la difficulté pour détecter des améliorations subtiles dans les performances cognitives en Phase I (i.e. chez des sujets sains) pourrait être palliée par le développement de paradigmes expérimentaux, tels que la privation de sommeil (PS), visant à induire des déficits cognitifs réversibles chez le sujet sain.Ainsi, l’EEG et l’EEG couplée à la privation de sommeil (PS) seraient des stratégies innovantes et pertinentes pour juger et prédire l’efficacité clinique d’une molécule en Phase I.Dans ce travail, nous tentons de juger de la pertinence de telles stratégies en identifiant, chez des sujets sains, des marqueurs EEG du fonctionnement cognitif liés soit (1) à la prise d’un médicament ayant un effet sur la cognition, (2) soit à l’induction d’un déclin cognitif réversible, (3) soit à l’effet concomitant des deux paramètres. Pour y parvenir, deux études ont été réalisées.Dans une première étude, l’effet du donepezil sur l’activité électrique corticale a été étudié chez 30 volontaires adultes, jeunes et sains. Ces volontaires ont été traités par donepezil (5 mg/jour per os) (vs. placebo) pendant 15 jours suivant une procédure en double aveugle, randomisée et en cross-over. _x000D_A la fin de la période de traitement, un EEG (58 voies) a été réalisé au cours de deux tâches attentionnelles (auditive et visuelle). Les potentiels évoqués cognitifs (PEC), la cohérence de phase inter-essais (ITC) et la perturbation spectrale liée à l’événement (ERSP) ont ensuite été calculés.Dans une deuxième étude, l’effet d’une PS a été étudié chez 36 volontaires adultes, jeunes et sains. De plus, l’effet d’un médicament ayant un effet bien connu sur la cognition (en particulier sur la vigilance), le modafinil, a également été étudié sur cette PS.Suite à une PS de 24 h, les participants se sont vus administrés une dose de modafinil (200 mg en prise unique) (vs. placebo) suivant une procédure en double aveugle, randomisée et en cross-over. Un EEG (25 voies) a été réalisé au cours d’une tâche attentionnelle auditive (identique à celle de l’étude I) avant et après la PS. Les PEC, l’ITC et l’ERSP ont ensuite été calculés.Grâce à ces deux études, nous avons identifié, à l’échelle de groupe, des marqueurs EEG de la cognition liés soit à l’induction d’un déclin cognitif (induit par une PS), soit à l’intervention pharmacologique ciblant le système cholinergique (donepezil) ou différents neurotransmetteurs (modafinil). L’ensemble de ces marqueurs porterait sur la modulation de l’activité corticale au sein du réseau fronto-pariétal ventral, connu pour régir les processus attentionnels et exécutifs. Nous avons également confirmé que ce réseau serait sous-tendu par des activités oscillatoires δ/θ et α. L’efficience cognitive serait le reflet de l’intégrité de ce réseau.Nous avons conclu que l’EEG est un outil suffisamment sensible pour détecter des changements subtils dans les processus neurocognitifs de participants adultes, jeunes et sains suivant l’administration d’un traitement de la MA et de manière plus générale suivant l’administration d’un médicament ayant un effet sur la cognition lorsqu’un déclin cognitif est provoqué (PS).Sous réserve de réplication des résultats et d’analyses complémentaires, l’EEG ainsi que l’EEG couplée à la PS pourraient constituer des outils additionnels à l’évaluation cognitive pour prédire l’efficacité de nouveaux candidat médicaments de la MA. / Symptomatic pharmacological treatments currently marketed for Alzheimer’s disease (AD) have a modest effect on cognitive functioning. In addition, the clinical development of new and more effective compounds is hampered by the lack of predictive criteria to judge their early clinical efficacy.In this context, electroencephalography (EEG) could be a sufficiently sensitive biomarker to identify in an early stage (i.e. Phase I) the therapeutic potential of a new molecule on cognitive functioning. In addition, the difficulty to detect subtle improvements in cognitive performance in Phase I (i.e. in healthy subjects) could be overcome by the development of experimental paradigms such as sleep deprivation (SD), to induce cognitive deficits, still reversible in healthy subjects.EEG and EEG coupled with sleep deprivation (SD) would be innovative and relevant strategies to determine and predict the clinical effectiveness of a molecule in Phase I.In this work, we try to determine the relevance of such strategies by identifying, in healthy subjects, EEG markers of cognitive functioning related to (1) either the taking of a cognitive drug, (2) or the induction of a reversible cognitive decline, (3) or concomitant effects of the two parameters. In order to do that, two studies were performed.In a first study, the effect of donepezil on cortical electrical activity was studied in 30 young, healthy adult volunteers. These volunteers were treated with donepezil (5 mg/day orally) (vs. placebo) for 15 days following a double-blind, randomized, cross-over trial.At the end of the treatment period, an EEG (58 electrodes) was performed during two attentional tasks (auditory and visual). Event-related potentials (ERP), the inter-trial coherence (ITC) and the event-related spectral perturbation (ERSP) were then calculated.In a second study, the effect of SD was studied in 36 young, healthy adult volunteers. In addition, the effect of a cognitive drug (involving high alertness), the modafinil was also studied on this SD._x000D_Following a SD of 24 h, the participants were administered a dose of modafinil (200 mg in a single dose) (vs. placebo) in a double-blind, randomized, cross-over trial. An EEG (25 electrodes) was performed in a hearing attentional task (identical to that of Study 1) before and after the PS. The ERP, ITC and ERSP were then calculated.Through these two studies, we have found, at the group level, cognitive EEG markers related either to the induction of cognitive decline (SD) or pharmacological intervention targeting cholinergic system (donepezil) or several neurotransmitters (modafinil). All these markers would concern the modulation of cortical activity in the ventral frontoparietal network, known to regulate attentional and executive processes. We also confirmed that the network is underlying by δ/θ and α oscillatory activities. The cognitive efficiency would reflect the integrity of the network.We conclude that EEG is a sufficiently sensitive tool to detect subtle changes in neurocognitive processes of young, healthy adult volunteers, following the administration of a treatment of AD and more generally following the administration of a drug having an effect on cognition when cognitive decline is caused (SD).EEG and EEG coupled with SD could constitute additional tools to the current cognitive assessment for predicting the efficacy of new drug candidates for AD before initiation Phases II/III clinical trials. However, the present works needs to be replicated so that the EEG markers described here can be validated so as to be used in drug trials.

The Side Effects of Drugs Annuals forms a series of volumes in which the adverse effects of drugs and adverse reactions to them are surveyed. The series supplements the contents of Meyler's Side Effects of Drugs: The International Encyclopedia of Adverse Drug Reactions and Interactions. The purpose of this supplement is to provide a concise reference of the newly available literature to support the existing information regarding the known adverse effects of commonly prescribed medications or abused drugs. The information covers peer-reviewed publications from January 2016 to December 2016. This review focused on CNS stimulants and drugs that suppress appetite. It covers amphetamines (including lisdexamfetamine, methamphetamine and 3,4-methylenedioxymetamphetamine), methylphenidate, atomoxetine, modafinil and armodafinil, methylxanthines (caffeine), monotherapies and combinational therapies that suppress appetite (lorcaserin, phentermine, phentermine/topiramate) and medications used in Alzheimer's disease and cognitive decline (rivastigmine, donepezil and memantine).

Alzheimer’s disease (AD) is a chronic, progressive neurodegenerative disorder, characterized clinically by a progressive loss of memory, cognitive function, ability to care for oneself and psychiatric symptoms. First-line agents for the treatment of AD are ChE inhibitors (DON, GAL), whose modest clinical efficacy and the high incidence of dose-limiting toxicities limit their clinical utility. In addition to AD, ChE inhibitors (PYR) are used for other medical conditions, such as myasthenia gravis (MG). Furthermore, ChE inhibitors (PYR) are used by military personnel prophylactically if impending exposure to chemical warfare agents, e.g., soman, is suspected. The purpose of this research project was to understand the effect of age on the in-vitro sensitivity of ChE inhibitors in human RBCs and plasma. Understanding possible covariates, such as age and gender, may assist in optimizing dosing regimens of ChE inhibitors and/or developing newer ChE inhibitors with better adverse effect profiles. Plasma PHYS concentrations were measured by a validated HPLC-FD method. RBC AChE activity and plasma BuChE activity were measured by a modified Ellman’s colorimetric method using the model substrates, acetylthiocholine and butyrylthiocholine, respectively. The kinetics of RBC and plasma ChE activity followed Michaelis-Menten kinetics. Acetylthiocholine was found to be a nonselective substrate (RBC AChE Km = 73 μM; plasma BuChE Km = 117 μM); while butyrylthiocholine was a selective substrate for plasma BuChE (RBC AChE Km = 130,000 μM; plasma BuChE Km = 72 μM). For the following studies, RBC AChE activity was measured using acetylthiocholine as the substrate and plasma BuChE activity was measured using butyrylthiocholine as the substrate. This research project was performed in two parts: First, mechanistic studies of PHYS, PYR, DON and GAL, explored and determined the mechanism of in-vitro inhibition of RBC AChE and plasma BuChE inhibition, as well as the in-vitro degradation of PHYS in human whole blood, plasma and RBC. PHYS was rapidly degraded in human whole blood, RBC and plasma and followed Michaelis-Menten kinetics but its degradation clearance - scaled to whole blood clearance - was only predicted to account for 4-6% (i.e., 195-261 ml/min) of the reported total body clearance for PHYS (4500 ml/min). RBCs were responsible for 60% of the whole blood clearance while plasma accounted for 40% of the whole blood clearance. Inhibition results indicated that both PHYS and PYR were nonselective and rapid suicide ChE inactivators. PYR inactivated RBC AChE more rapidly at low concentrations and inactivated plasma BuChE more rapidly at high concentrations, but inactivated both more rapidly than PHYS. PHYS was a more potent inactivator than PYR with a Ki for RBC AChE of 0.011 μM and 0.063 μM, respectively, and 0.023 μM and 0.036 μM, respectively for plasma BuChE. DON was found to be a noncompetitive inhibitor for RBC AChE (Ki,noncomp = 114 μM), but a competitive inhibitor for plasma BuChE (Ki,comp = 213 μM). GAL was found to be a competitive inhibitor for both RBC AChE (Ki,comp = 66 μM) and plasma BuChE (Ki,comp = 358 μM). The second part involved a clinical study with ten young and nine elderly healthy subjects, balanced for gender, who donated blood for an in-vitro study in order to assess any age- and gender-related differences in in-vitro sensitivity to RBC AChE and plasma BuChE inhibition to all four ChE inhibitors. Elderly adults were found to be 2-3-fold less sensitive compared to the young adults for PHYS (BuChE Ki,pss; 0.010 and 0.015 μM, young and elderly, respectively) and PYR (AChE Ki,pss; 0.12 and 0.25 μM, young and elderly, respectively) only, while neither DON nor GAL showed any age-related differences in sensitivity. The observed differences for PHYS and PYR may be due to kinetic differences in ChE inactivation between young and aged adults, rather then a difference in binding affinities/potencies. These carbamate ChE inhibitors, presumably, have a slower decarbamoylation rate in younger adults than elderly adults, which leads to the observed difference in in-vitro sensitivity. The above in-vitro results were consistent with results of a meta-analysis: In a study by Knapp et al. (1991), young males (n=6), receiving 18 mg, 24 mg and 30 mg PHYS tablets, showed similar ex-vivo plasma BuChE sensitivity to (28 %/(ng/ml)) as the in-vitro sensitivity for young males in the current study (33 %/(ng/ml)). On the other hand, in the study by Men (2004), elderly males (n=8) and females (n=8), receiving 6.7 μg/kg PHYS as 30-minute infusion, showed similar ex-vivo RBC AChE sensitivity (12 %/(ng/ml)) as the in-vitro sensitivity for elderly subjects in the current study (9.7 %/(ng/ml)). This suggests that in-vitro measurement of ChE sensitivity is predictive of ex-vivo sensitivity in clinical studies. The study results suggest that elderly adults may require a 2-3-fold higher blood concentration than young adults to achieve the same ChE inhibition. This may explain why for epistigmine, an investigational carbamate ChE inhibitor for the treatment of AD, the maximum tolerated dose observed in young adults (40 mg single dose) was lower than for older adults (90 mg/day). Higher sensitivity in young adults prevented further dose escalation, while all elderly subjects tolerated higher doses. This research may have implications for other diseases and conditions, most notably MG and as a prophylaxis of nerve gases poisoning. As patients with MG age, they may become less sensitive to PYR, the most common symptomatic treatment for MG, and an increase in dose may be required. Further, older military personnel assigned to receive PYR, may require increased doses to achieve the targeted 10% RBC AChE inhibition, necessary to protect against nerve gas poisoning.