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Prospecção química e biológica do endófito Humicola fuscoatra associado a alga vermelha Asparagopsis taxiformis para obtenção de metabólitos secundários bioativos /Mendonça, Iatã do Carmo. January 2018 (has links)
Orientadora: Dulce Helena Siqueira Silva / Banca: Alberto José Cavalheiro / Banca: Taicia Pacheco Fill / Resumo: Considerando a variedade de compostos encontrados em produtos de origem natural, o estudo da biodiversidade de um país é de interesse tanto científico quanto econômico. Sendo possível destacar os ecossistemas marinhos que apresentam biodiversidade comparável às florestas tropicais. Devido ao ambiente diferenciado, muitas vezes inóspito, os habitantes do ambiente marinho exibem características bioquímicas diferenciadas, mostrando grande potencial para bioprospecção. A importância do estudo de organismos marinhos na busca por metabólitos secundários bioativos levou à proposta de aprofundar a prospecção química do fungo endofítico Humicola fuscoatra, isolado da alga vermelha Asparagopsis taxiformis. A partir de seu extrato foi possível purificar por técnicas cromatográficas, e identificar 7 substâncias com base nos dados de ressonância magnética nuclear uni e bidimensional (RMN de 1H, RMN de 13C, TOCSY-1D, COSY, HSQC, HMBC) e espectrometria de massas (EM). Dentre estes foram identificados um composto da classe das dicetopiperazinas (P01), duas isocumarinas (P02 e P05), além de 4 substâncias não relatadas na literatura, incluindo três valerolactamas (P03, P06 e P07) e uma cicloexadienona (P04). Além dos compostos purificados por CLAE, foi possível identificar duas substâncias por cromatografia a gás acoplada a espectrometria de massas (CG-EM) sendo elas uma dicetopiperazina e um ftalato. A variedade estrutural dos compostos isolados e a grande quimiodiversidade do extrato de Humi... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Seeing the variety of compounds obtained from natural products, study a country biodiversity have a scientific interest as well as economic. It is possible to highlight marine ecosystems that present biodiversity comparable to rainforests. Due to the unique environment, often inhospitable, the organisms of the marine environments display uncommon biochemical characteristics, showing great potential for bioprospecting. The importance of the study of marine organisms in the search for bioactive compounds led to the proposal to deepen the prospection of the endophytic fungus Humicola fuscoatra, isolated from the red alga Asparagopsis taxiformis. Its extract led to the purification by chromatographic methods, and identification of 7 compounds based on their NMR spectral data obtained by uni and bidimensional experiments (1H NMR, 13C NMR, TOCSY-1D, COSY, HSQC, HMBC) and mass spectrometry (MS). One diketopiperazine (P01), two isocoumarins (P02 and P05) in addition to four novel compounds, including three valerolactams (P03, P06 and P07) and one cyclehexadienone (P04) were isolated. Moreover another diketopiperazine and one phthalate derivative were identified by gas chromatography coupled to mass spectrometry (GC-MS). The structural variety of the identified compounds associated to the rich chemodiversity observed for the Humicola fuscoatra extract reinforces the need to develop additional chemical studies of endophytic fungal strains of marine origin, since they have been providin... (Complete abstract click electronic access below) / Mestre
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Uso de medicamentos em pacientes idosos portadores de doença de Alzheimer / Use of drugs in elderly patients with Alzheimer's diseaseDaltin, Jussemi Biazon [UNESP] 08 November 2016 (has links)
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Previous issue date: 2016-11-08 / Objetivos: Analisar o perfil da prescrição de inibidores da colinesterase e de outros medicamentos em pacientes idosos portadores de demência da doença de Alzheimer (ddA) atendidos em centro de atenção a idosos no município de Bauru/SP. Métodos: Estudo de delineamento transversal, descritivo e analítico, realizado com idosos portadores de demência da doença de Alzheimer (ddA), do Programa Municipal de Atenção ao Idoso (PROMAI), no período de abril de 2015 a agosto de 2015. Participantes: 81 idosos (66 mulheres e 15 homens) que faziam acompanhamento no Programa Municipal de Atenção ao Idoso (PROMAI). Resultados: Dos idosos, 81,5% pertencia ao sexo feminino, 92,6% tinham 75 anos ou mais de idade, 64,2% não eram casados, 58% tinham até 4 anos de escolaridade, 60,5% tinham renda de até um salário mínimo, 60,5% tinham como cuidador principal as filhas e 90,1% residiam com algum familiar. Dentre as comorbidades mais comuns associadas às demências encontramos hipertensão arterial (29,6%), diabetes melitus (13,4%), hipotireoidismo (8,4%) e dislipidemias (7,8%). A capacidade cognitiva expressa pelo MEEM foi em média 14,5 pontos. A polifarmácia esteve presente em 63% dos idosos e, dentre eles, 77,8% faziam uso de algum MPI. A frequência de prescrição dos ICH foi: 54,9% rivastigmina, 33,3% donepezila e 11,8% galantamina. A memantina teve uma prevalência de prescrição de 2,5%. Dos motivos do não uso de tratamento para a ddA, os efeitos colaterais indesejáveis representaram 28% dos casos. Dos idosos estudados, 91% tinha acesso ao tratamento com os ICH através do programa de medicamentos do CEAF. O CDR (Clinical Dementia Rating) não foi encontrado na totalidade dos prontuários analisados. Conclusão: A polifarmácia esteve presente em 63% dos idosos estudados e 77,8% faziam uso de algum MPI. A polifarmácia teve associação estatisticamente positiva com o número de comorbidades (p=0,0018), escolaridade (p=0,0017), hipertensão arterial (p=0,0013) e diabetes melittus (p<0,01) e o uso de MPI apresentou associação estatisticamente positiva com a polifarmácia (p<0,01). Dos medicamentos para tratar a ddA a rivastigmina aparece com a maior prevalência de uso, 34,6%, e 30,9% não faziam uso de nenhum tratamento para a ddA. Efeitos colaterais indesejáveis e doença em estado avançado, 28%, aparecem como os principais motivos de não uso de medicamentos. / Objectives: To analyze the profile of prescribing cholinesterase inhibitors and other medications in elderly patients with Dementia of Alzheimer's disease (DAD) met in Center of attention for the elderly in the city of Bauru/SP. Methods: Study of transverse, descriptive and analytical design, conducted with elderly patients with Dementia of Alzheimer's disease (DAD), in the Municipal Program of Attention to the older persons (PROMAI), from April to August 2015. Participants: 81 elderly (66 women and 15 men) who were monitoring the Municipal program of Attention to the Elderly (PROMAI). Results: Of the elderly 81.5% belonged to the female, 92.6% were 75 years or older, 64.2% were unmarried, 58% had up to 4 years of schooling, 60.5% had incomes up to 1 minimum salary, 60.5% had as main caregiver daughters and 90.1% lived with a family member. Among the most prevalent comorbid associated with dementias found Hypertension (29.6%), Diabetes mellitus (13.4%), Hypothyroidism (8.4%) and dyslipidemias (7.8%). Cognitive ability expressed by the MMSE was an average of 14.5 points. The polypharmacy was present in 63% of the elderly and among the elderly 77.8% made use of some MPI. The frequency of prescription of (the) ICH was: 54.9% rivastigmine, 33.3% Donepezil and 11.8% galantamina. Memantine had a prevalence of prescription of 2.5%. The reasons of the non-use of treatment for DAD, the undesirable side effects accounted for 28% of the cases. The elderly studied 91% had access to treatment with the ICH trough medication program CEAF. The CDR (Clinical Dementia Rating) was not found in all the analyzed records. Conclusion: Polypharmacy was present in 63% of the elderly studied and 77.8% made use of some MPI. The polypharmacy had statistically positive association with the number of comorbid (p<0.01), education (p < 0.01), hypertension (p<0.01) and melittus diabetes (p<0.01) and the use of MPI presented statistically positive association with polypharmacy (p < 0.01). Of the medications to treatment DAD the rivastigmine appears with the higher prevalence of use, 34.6% and 30.9% did not use any treatment for DAD. Undesirable side effects and advanced-stage disease, 28%, appear as the main reasons for non-use of medicines
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Synthèse multicomposants et évaluation pharmacologique de nouveaux adduits de Ugi et de Passerini pour le traitement de la maladie d'Alzheimer / Multicomponent synthesis and pharmacological assessment of new Ugi and Passerini adducts for the treatment of Alzheimer’s diseaseBenchekroun, Mohamed 19 December 2014 (has links)
La maladie d'Alzheimer est la pathologie neurodégénérative la plus courante affectant les personnes âgées. Cette neuropathologie se caractérise par une étiologie complexe dont le déficit en acétylcholine, les plaques amyloïdes, les dégénérescences neurofibrillaires ou le stress oxydant en sont les principaux acteurs.Au cours de cette thèse, nous nous sommes intéressés à l'application des réactions multicomposants de Ugi et de Passerini, pour la synthèse de nouveaux adduits multi-cibles basées sur différents motifs antioxydants et anticholinestérasiques. Ces réactions permettent d'accéder à une vaste diversité chimique en une étape, ce qui les rend adaptées pour la synthèse rapide de molécules ayant plusieurs pharmacophores d'intérêt et ciblant ainsi différentes cause étiologiques de la maladie d'Alzheimer.Au total, 56 composés finaux, répartis dans cinq séries, ont été synthétisés :les alpha-acylaminocarboxamides prototypes (série A)les hybrides tacrine-acide férulique (série B)les hétérotrimères tacrine-mélatonine-acides antioxydant (série C)> les hybrides donépézil-acide férulique (série D)^ les dérivés chromone (série E)Toutes les séries ont été évaluées pour leur capacité à inhiber les enzymes cholinestérases et leur pouvoir antioxydant. L'hépatotoxicité des séries B et C. portant un motif tacrine, a été évaluée sur les cellules HepG2. Par ailleurs, l'étude de la série B a été complétée par d'autres tests pharmacologiques, physico-chimiques et toxicologiques.Ces différents travaux démontrent et valident l'utilisation des réactions de Ugi et de Passerini dans le développement de molécules multi-cibles pour le traitement potentiel de la maladie d'Alzheimer. / Alzheimer's disease (AD) is thé most common type of dementia affecting elderly people. This neuropathology is characterized by a highiy complex and intricated etiology including cholinergic déficit, amyloid deposits, neurofibrillary tangles and oxidative stress.During this thesis, we sought to apply Ugi and Passerini multicomponent reactions for thé synthesis of new multi-target adducts based on différent antioxidant and anticholinergic scaffolds.Thèse réactions provides access to a broad range of chemical diversity in a one-pot fashion, which makes them suitable for thé expeditious synthesis of molécules having several pharmacophores of interest and hitting différent targets related to thé multifaceted etiology of Alzheimer's disease.A total of 56 final compounds, spread over 5 séries, hâve been synthesized:alpha-acylaminocarboxamides prototypes (A séries)tacrine-ferulic acid hybrids (B séries)tacrine-melatonin-antioxydant acids heterotrimers (C séries)donepezil-ferulic acid hybrids (D séries)Chromone derivatives (E séries)Ail thé séries were tested for their ability to inhibit thé cholinesterases enzymes and for their antioxidant power. Hepatotoxicity of thé B and C séries, bearing a tacrine fragment, was evaluated on HepG2 cells. Moreover, thé study of thé B séries was supplemented by further pharmacological, physicochemical and toxicological tests (NMR conformational study, neuroprotection on SH-SY5Y cells. self-induced Abetai.42 peptide aggregation inhibition, docking ADMET).Such work demonstrated and validated thé use of Ugi and Passerini reactions for thé development of new multi-target directed molécules for thé potential treatment of AD.
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Biomarcadores na doença de Alzheimer: GSK3B e PLA2 na resposta aos inibidores de colinesterase / Biomarkers in Alzheirmer\'s disease: GSK3B and PLA2 in response to cholinesterase inhibitorsTalib, Leda Leme 23 May 2014 (has links)
A Doença de Alzheimer (DA) é uma desordem neurodegenerativa progressiva que causa comprometimento cognitivo e demência. O diagnóstico é baseado em parâmetros clínicos, mas sua confirmação é post-mortem, após avaliação patológica durante a autópsia. Os tratamentos disponíveis para a DA são os inibidores da colinesterase (IChEs) e os antagonistas de receptores de N-metil-D-aspartato (NMDA), sendo que os IChEs compõe o principal grupo. Diversos estudos tem mostrado um efeito neuroprotetor dos IChEs, levando a alterações na patogênese da DA. Avaliar e mensurar essas alterações são papeis atribuídos aos biomarcadores. Neste sentido podemos destacar a fosfolipase A2 (PLA2), a principal responsável pelo metabolismo de fosfolípides de membrana, e que tem sido achada diminuída na DA, assim como a glicogênio sintase-quinase (GSK), responsável pela fosforilação da proteína Tau, que é um dos processos alterados na DA. O objetivo deste trabalho foi avaliar o efeito do tratamento com IChE sobre a atividade da PLA2 e expressão da GSK3B em plaquetas de 30 pacientes com DA após 3 e 6 meses de tratamento. Como grupo controle foram investigados 42 individuos idosos sem doença neurodegenerativa. Encontramos nos pacientes com DA antes do tratamento uma diminuição da atividade da iPLA2 quando comparada ao grupo controle. Após três e seis meses de tratamento a PLA2 aumentou, voltando ao nível dos controles. Os pacientes que apresentaram um aumento maior da iPLA2 apos 3 meses de tratamento apresentaram melhora cognitiva mais marcante após seis meses de tratamento, avaliado pelo CAMCOG. Apos 6 meses de tratamento encontramos um inativação da GSK3B, medida por um aumento em sua forma fosforilada. Nossos resultados sugerem que o donepezil apresenta propriedades modificadoras na doença de Alzheimer, e ainda que a medida da atividade da iPLA2 poderia ser usada como marcador de resposta terapêutica ao donepezil e, possivelmente, a outros IChEs, na doença de Alzheimer / Alzheimer\'s disease (AD) is a progressive neurodegenerative disorder that causes dementia and cognitive impairment. The Diagnosis is based on clinical parameters, but confirmation is post-mortem after pathologic evaluation during autopsy. The treatments available for AD are cholinesterase inhibitors (IChEs) and N-methyl-D-aspartate (NMDA) antagonists. The main group comprises the IChEs. Several studies have shown a neuroprotective effect of IChEs, leading to alterations in the pathogenesis of AD. Evaluate and measure these changes are assigned to biomarkers. In this regard we can highlight the phospholipase A2 (PLA2) the main enzyme in membrane phospholipids metabolism and that has been found decreased in AD as well as Glycogen Synthase kinase (GSK), a major responsible for tau phosphorylation which is one processes altered in AD. The objective of this study was to evaluate the effect of treatment with IChE on PLA2 activity and GSK3B expression in platelet of 30 AD patients after 3 and 6 months of treatment. The control group comprised 42 elderly individuals without neurodegenerative disease The results obtained were a decreased iPLA2 activity in patients with AD before treatment as compared to controls. After 3 and 6 months of treatment, we observed a significant increase in iPLA2 activity, restoring enzymatic activity similar to that observed among control. The patients who showed higher iPLA2 activity in the first three months were those showing cognitive improvement after six months of treatment, measured by CAMCOG. After 6 months of treatment a GSK3B inactivation were found, measured by an increase in its phosphorylated form. Our results suggest that donepezil present modifying properties in Alzheimer disease and that iPLA2 activity measurement could be used as a marker of therapeutic response to donepezil and possibly other IChEs in Alzheimer\'s disease
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Biomarcadores na doença de Alzheimer: GSK3B e PLA2 na resposta aos inibidores de colinesterase / Biomarkers in Alzheirmer\'s disease: GSK3B and PLA2 in response to cholinesterase inhibitorsLeda Leme Talib 23 May 2014 (has links)
A Doença de Alzheimer (DA) é uma desordem neurodegenerativa progressiva que causa comprometimento cognitivo e demência. O diagnóstico é baseado em parâmetros clínicos, mas sua confirmação é post-mortem, após avaliação patológica durante a autópsia. Os tratamentos disponíveis para a DA são os inibidores da colinesterase (IChEs) e os antagonistas de receptores de N-metil-D-aspartato (NMDA), sendo que os IChEs compõe o principal grupo. Diversos estudos tem mostrado um efeito neuroprotetor dos IChEs, levando a alterações na patogênese da DA. Avaliar e mensurar essas alterações são papeis atribuídos aos biomarcadores. Neste sentido podemos destacar a fosfolipase A2 (PLA2), a principal responsável pelo metabolismo de fosfolípides de membrana, e que tem sido achada diminuída na DA, assim como a glicogênio sintase-quinase (GSK), responsável pela fosforilação da proteína Tau, que é um dos processos alterados na DA. O objetivo deste trabalho foi avaliar o efeito do tratamento com IChE sobre a atividade da PLA2 e expressão da GSK3B em plaquetas de 30 pacientes com DA após 3 e 6 meses de tratamento. Como grupo controle foram investigados 42 individuos idosos sem doença neurodegenerativa. Encontramos nos pacientes com DA antes do tratamento uma diminuição da atividade da iPLA2 quando comparada ao grupo controle. Após três e seis meses de tratamento a PLA2 aumentou, voltando ao nível dos controles. Os pacientes que apresentaram um aumento maior da iPLA2 apos 3 meses de tratamento apresentaram melhora cognitiva mais marcante após seis meses de tratamento, avaliado pelo CAMCOG. Apos 6 meses de tratamento encontramos um inativação da GSK3B, medida por um aumento em sua forma fosforilada. Nossos resultados sugerem que o donepezil apresenta propriedades modificadoras na doença de Alzheimer, e ainda que a medida da atividade da iPLA2 poderia ser usada como marcador de resposta terapêutica ao donepezil e, possivelmente, a outros IChEs, na doença de Alzheimer / Alzheimer\'s disease (AD) is a progressive neurodegenerative disorder that causes dementia and cognitive impairment. The Diagnosis is based on clinical parameters, but confirmation is post-mortem after pathologic evaluation during autopsy. The treatments available for AD are cholinesterase inhibitors (IChEs) and N-methyl-D-aspartate (NMDA) antagonists. The main group comprises the IChEs. Several studies have shown a neuroprotective effect of IChEs, leading to alterations in the pathogenesis of AD. Evaluate and measure these changes are assigned to biomarkers. In this regard we can highlight the phospholipase A2 (PLA2) the main enzyme in membrane phospholipids metabolism and that has been found decreased in AD as well as Glycogen Synthase kinase (GSK), a major responsible for tau phosphorylation which is one processes altered in AD. The objective of this study was to evaluate the effect of treatment with IChE on PLA2 activity and GSK3B expression in platelet of 30 AD patients after 3 and 6 months of treatment. The control group comprised 42 elderly individuals without neurodegenerative disease The results obtained were a decreased iPLA2 activity in patients with AD before treatment as compared to controls. After 3 and 6 months of treatment, we observed a significant increase in iPLA2 activity, restoring enzymatic activity similar to that observed among control. The patients who showed higher iPLA2 activity in the first three months were those showing cognitive improvement after six months of treatment, measured by CAMCOG. After 6 months of treatment a GSK3B inactivation were found, measured by an increase in its phosphorylated form. Our results suggest that donepezil present modifying properties in Alzheimer disease and that iPLA2 activity measurement could be used as a marker of therapeutic response to donepezil and possibly other IChEs in Alzheimer\'s disease
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A retrospective study of cholinesterase inhibitors for Alzheimer's disease : the effect of cerebrovascular disease on patient outcomes and the impact of biases on the results.Charbonneau, Claudie 04 1900 (has links)
Introduction: La démence peut être causée par la maladie d’Alzheimer (MA), la
maladie cérébrovasculaire (MCEREV), ou une combinaison des deux. Lorsque la
maladie cérébrovasculaire est associée à la démence, les chances de survie sont
considérées réduites. Il reste à démontrer si le traitement avec des inhibiteurs de la
cholinestérase (ChEIs), qui améliore les symptômes cognitifs et la fonction
globale chez les patients atteints de la MA, agit aussi sur les formes vasculaires de
démence.
Objectifs: La présente étude a été conçue pour déterminer si la coexistence d’une
MCEREV était associée avec les chances de survie ou la durée de la période
jusqu’au placement en hebergement chez les patients atteints de la MA et traités
avec des ChEIs. Des études montrant de moins bons résultats chez les patients
souffrant de MCEREV que chez ceux n’en souffrant pas pourrait militer contre
l’utilisation des ChEIs chez les patients atteints à la fois de la MA et la MCEREV.
L'objectif d'une seconde analyse était d'évaluer pour la première fois chez les
patients atteints de la MA l'impact potentiel du biais de « temps-immortel » (et de
suivi) sur ces résultats (mort ou placement en hebergement).
Méthodes: Une étude de cohorte rétrospective a été conduite en utilisant les bases
de données de la Régie de l’Assurance Maladie du Québec (RAMQ) pour
examiner la durée de la période jusqu’au placement en hebergement ou jusqu’au
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décès des patients atteints de la MA, âgés de 66 ans et plus, avec ou sans
MCEREV, et traités avec des ChEIs entre le 1er Juillet 2000 et le 30 Juin 2003.
Puisque les ChEIs sont uniquement indiquées pour la MA au Canada, chaque
prescription de ChEIs a été considérée comme un diagnostic de la MA. La
MCEREV concomitante a été identifié sur la base d'un diagnostic à vie d’un
accident vasculaire cérébral (AVC) ou d’une endartériectomie, ou d’un diagnostic
d'un accident ischémique transitoire au cours des six mois précédant la date
d’entrée. Des analyses séparées ont été conduites pour les patients utilisant les
ChEIs de façon persistante et pour ceux ayant interrompu la thérapie. Sept
modèles de régression à risque proportionnel de Cox qui ont varié par rapport à la
définition de la date d’entrée (début du suivi) et à la durée du suivi ont été utilisés
pour évaluer l'impact du biais de temps-immortel.
Résultats: 4,428 patients ont répondu aux critères d’inclusion pour la MA avec
MCEREV; le groupe de patients souffrant seulement de la MA comptait 13,512
individus. Pour le critère d’évaluation composite considérant la durée de la
période jusqu’au placement en hebergement ou jusqu’au décès, les taux de survie
à 1,000 jours étaient plus faibles parmi les patients atteints de la MA avec
MCEREV que parmi ceux atteints seulement de la MA (p<0.01), mais les
différences absolues étaient très faibles (84% vs. 86% pour l’utilisation continue
de ChEIs ; 77% vs. 78% pour la thérapie avec ChEIs interrompue). Pour les
critères d’évaluation secondaires, la période jusqu’au décès était plus courte chez
les patients avec la MCEREV que sans la MCEREV, mais la période jusqu’au
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placement en hebergement n’était pas différente entre les deux groupes. Dans
l'analyse primaire (non-biaisée), aucune association a été trouvée entre le type de
ChEI et la mort ou le placement en maison d'hébergement. Cependant, après
l'introduction du biais de temps-immortel, on a observé un fort effet différentiel.
Limitations: Les résultats peuvent avoir été affectés par le biais de sélection
(classification impropre), par les différences entre les groupes en termes de
consommation de tabac et d’indice de masse corporelle (ces informations
n’étaient pas disponibles dans les bases de données de la RAMQ) et de durée de
la thérapie avec les ChEIs.
Conclusions: Les associations entre la coexistence d’une MCEREV et la durée de
la période jusqu’au placement en hebergement ou au décès apparaissent peu
pertinentes cliniquement parmi les patients atteints de la MA traités avec des
ChEIs. L’absence de différence entre les patients atteints de la MA souffrant ou
non de la MCEREV suggère que la coexistence d’une MCEREV ne devrait pas
être une raison de refuser aux patients atteints de la MA l’accès au traitement avec
des ChEIs. Le calcul des « personne-temps » non exposés dans l'analyse élimine
les estimations biaisées de l'efficacité des médicaments. / Introduction: Dementia may be caused by Alzheimer’s disease (AD),
cerebrovascular disease (CVD), or a combination of both. When CVD is
associated with dementia, survival is thought to be reduced. It is unclear whether
treatment with cholinesterase inhibitors (ChEIs), which has been found to
improve cognitive symptoms and global function in AD patients, has similar
benefits in vascular forms of dementia.
Objectives: The present study was designed to determine whether co-existing
CVD is associated with survival or time to nursing home placement (NHP) among
AD patients treated with ChEIs. Findings of poorer outcomes in patients with
versus without CVD might argue against the use of ChEIs for AD patients in
whom CVD co-exists. The objective of a second analysis was to assess for the
first time in patients with AD the potential impact of immortal time (and followup)
bias on risk for these outcomes.
Methods: A retrospective cohort study was undertaken using the Régie de
l’Assurance Maladie du Québec (RAMQ) databases to examine the time to NHP
or death for AD patients aged 66+, with or without CVD, treated with ChEIs
between July 1, 2000, and June 30, 2003. Because ChEIs are approved only for
AD in Canada, a ChEI prescription was used as a surrogate for an AD diagnosis.
Concomitant CVD was identified on the basis of a lifetime diagnosis of stroke or
ii
endarterectomy, or a diagnosis of transient ischemic attack within the six months
prior to the index date. Separate analyses were performed for patients with
persistent ChEI use and those who discontinued ChEI therapy. Seven Cox
proportional hazard regression models which varied in the definition of the index
date (start of follow-up) and the duration of follow-up were used to evaluate the
impact of immortal time bias.
Results: 4,428 patients met inclusion criteria for AD with CVD; 13,512 were
classified as having AD alone. For the composite endpoint of NHP or death,
1,000-day survival rates were lower among AD patients with versus without CVD
(p<0.01), but absolute differences were very small (84% vs. 86% with continuous
ChEI use; 77% vs. 78% with discontinuous ChEI therapy). Of the secondary
endpoints, time to death was shorter for patients with versus without CVD, but
time to NHP did not differ between groups. In the primary, unbiased analysis, no
association was found between ChEI treatment type and death or NHP. However,
after introduction of immortal time bias, a strong differential effect was observed.
Limitations: Results may have been affected by selection (misclassification) bias,
between-group differences in smoking and body mass index (information on
which was not available in the RAMQ databases), and duration of ChEI therapy.
Conclusions: Associations between co-existing CVD and time to NHP or death
appeared to be of little clinical relevance among AD patients treated with ChEIs.
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The lack of difference between AD patients with and without CVD suggests that
CVD should not be used as a reason to deny AD patients access to ChEI
treatment. Properly accounting for unexposed person-time in the analysis
eliminates biased estimates of drug efficacy.
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A retrospective study of cholinesterase inhibitors for Alzheimer's disease : the effect of cerebrovascular disease on patient outcomes and the impact of biases on the resultsCharbonneau, Claudie 04 1900 (has links)
No description available.
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Pathophysiology of Respiratory Failure Following Acute Organophosphate Poisoning : A DissertationGaspari, Romolo Joseph 01 December 2009 (has links)
Organophosphate (OP) poisoning is a health issue worldwide with over 200,000 deaths per year. Although not a problem in most developed countries, in some third world countries, one third of a hospital’s population could be patients with OP exposure. Even with the most aggressive therapy, 10-40% of patients admitted to an intensive care unit will die. Research into the best practice for treating OP poisoning is lacking, due somewhat to a lack of detailed understanding of the physiology of OP poisoning. Our research uses animal models of acute OP poisoning to explore the mechanism of OP-induced respiratory failure.
Our research shows that animals poisoned with dichlorvos demonstrated a uniformly fatal central apnea that, if prevented, was followed immediately by a variable pulmonary dysfunction. Potential mechanisms for dichlorvos-induced central apnea can be divided into direct effects on the central respiratory oscillator (CRO) and feedback inhibition of the CRO. Two afferent pathways that can induce apnea include vagal feedback pathways and feed-forward pathways from the cerebral hemispheres. In our studies we found that vagal feedback and feed forward inhibition from the cerebral hemispheres were not required for OP-induced central apnea. The pre-Botzinger complex in the brainstem is thought to be the kernel of the CRO, but exposure of the pre-Botzinger complex to dichlorvos was not sufficient for apnea. Although OP induced central apnea was uniformly fatal, partial recovery of the CRO occurred post apnea with mechanical ventilation.
Central apnea was ubiquitous in our rat poisoning model, but pulmonary dysfunction was extremely variable, with a range of pulmonary effects from fulminate pulmonary failure with prominent pulmonary secretions to no pulmonary dysfunction at all. Vagal efferent activity is involved in neural control of pulmonary tissue but the vagus was not involved in OP-induced pulmonary dysfunction. Anti-muscarinic medications are the mainstay of clinical therapy and are commonly dosed by their effects on pulmonary secretions. Our studies found that atropine (the most common therapeutic agent for OP poisoning) resulted in a ventilation-perfusion mismatch secondary to effects on the pulmonary vasculature.
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Age-Related Differences in In-vitro Sensitivity to Inhibition of Human Red Blood Cell Acetylcholinesterase and Plasma Butyrylcholinesterase by the Cholinesterase Inhibitors Physostigmine (PHYS), Pyridostigmine (PYR), Donepezil (DON) and Galantamine (GAL)Lee, David 31 July 2009 (has links)
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.
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"Reabilitação neuropsicológica dos processos de memória e das atividades da vida diária em pacientes com doença de Alzheimer leve e moderada" / Neuropsychological rehabilitation of memory processes and activities of daily living in mild and moderate Alzheimer's disease patientsÁvila, Renata 16 June 2004 (has links)
O efeito da reabilitação neuropsicológica foi verificado em uma amostra de 16 pacientes com diagnóstico de doença de Alzheimer leve e moderado. Após ensaio clínico aberto com rivastigmina por 4 meses, os pacientes foram divididos em três grupos: sessões em grupo, individual e em casa com o cuidador. Os três grupos realizaram o mesmo protocolo de reabilitação, e antes e depois das 22 semanas de tratamento foram avaliados pelos mesmos instrumentos. Os resultados indicaram que as sessões em grupo são mais eficientes para sintomas psiquiátricos; individual para atividades da vida diária; e em casa, dependendo do perfil do paciente e do cuidador, pode ser uma alternativa de tratamento / The effect of a neuropsychological rehabilitation was tested in a sample of 16 patients with mild and moderate Alzheimer disease. After an open trial with rivastigmine for 4 months, they were divided in 3 groups: group sessions, individualized and at home with a caregiver. All 3 groups fulfilled the same rehabilitation protocol, and just before and after the 22 week period of treatment, all patients were evaluated using the same instruments. The results of the study indicated that group session are more effective for psychiatric symptoms, individualized sessions for activities of daily living training and at home training, depending on the patient's and caregiver's profiles, can be an option for treatment of these patients
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