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Ezio Giacobini

Publications and source records attributed to Ezio Giacobini.

8 recordsLinked to original sources
PubMed2005

[The economical impact of dementia].

An epidemiology closely linked with the increase in life span. In most countries, the prevalence of dementia varies between 6 and 8% for individuals aged 65 years or more. It then dramatically increases with each subsequent decade, reaching around 30% of the population aged over 85. The costs associated with dementia are correlated with the increase in age and are of increasing concern for politicians, healthcare professionals and family members of demented patients. Current estimations are approximate, but dementia appears to be the most costly disease for society after the age of 65 years in France, the Netherlands, Sweden, or the United States. Detailed cost analyses have distinguished the direct medical,direct non-medical and intangible costs. The most important contribution in costs for society is the long-term care by health care professionals (institutionalization corresponding to 2/3 of the total costs for society!), but the care provided by the helpers and the families is even greater, even though difficult to quantify. The current question is to know whether present and future medical treatments will be able to reduce the tremendous financial costs of this chronic disease.

Activities of Daily Living↗
PubMed2005

Reality orientation therapy combined with cholinesterase inhibitors in Alzheimer's disease: randomised controlled trial.

BACKGROUND: Reality orientation therapy combined with cholinesterase inhibitors has not been evaluated in patients with Alzheimer's disease. AIMS: To perform such an evaluation. METHOD: We randomly assigned 79 of 156 patients treated with donepezil to receive a reality orientation programme. Caregivers of the treatment group were trained to offer the programme at home 3 days a week, 30 min/day, for 25 consecutive weeks, and were invited to stimulate and involve patients in reality-based communication. RESULTS: The treatment group showed a slight improvement in Mini-Mental State Examination (MMSE) scores (mean change +0.2, s.e.=0.4) compared with a decline in the control group (mean change -1.1, s.e.=0.4; P=0.02). Similarly for the Alzheimer's Disease Assessment Scale--Cognition (treatment group mean change +0.4, s.e.=0.8; control group -2.5, s.e.=0.8; P=0.01). The intervention had an equal effect on cognition in those with mild (MMSE score > or = 20) and moderate (score <20) dementia. No significant effect was observed for behavioural and functional outcomes. CONCLUSIONS: Reality orientation enhances the effects of donepezil on cognition in Alzheimer's disease.

Adult↗
PubMed2004

Cholinesterase inhibitors: new roles and therapeutic alternatives.

An important aspect of brain cholinesterase function is related to enzymatic differences. The brain of mammals contains two major forms of cholinesterases: acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The two forms differ genetically, structurally and for their kinetics. Butyrylcholine is not a physiological substrate in mammalian brain which makes the function of BuChE of difficult interpretation. In human brain, BuChE is found in neurons and glial cells as well as in neuritic plaques and tangles in Alzheimer disease (AD) patients. While AChE activity decreases progressively in the brain of AD patients, BuChE activity shows some increase. In order to study the function of BuChE, we perfused intracortically the rat brain with a selective BuChE inhibitor and found that extracellular acetylcholine increased 15 fold from 5 to 75nM concentrations with little cholinergic side effects in the animal. Based on these data and on clinical data showing a relation between CSF BuChE inhibition and cognitive function in AD patients, we postulated that two pools of cholinesterases may be present in brain, the first mainly neuronal and AChE dependent and the second mainly glial and BuChE dependent. The two pools show different kinetic properties with regard to regulation of ACh concentration in brain and can be separated with selective inhibitors. Within particular conditions, such as in mice nullizygote for AChE or in AD patients at advanced stages of the disease, BuChE may replace AChE in hydrolyzing brain acetylcholine. Based on the changes of ChE activity in the brain of AD patients, a rational indication of selective BuChEI (or of mixed double function inhibitors) is the treatment of advanced cases. A second novel aspect of ChEI therapy is the emerging of new indications which include various forms of dementia such as dementia with Lewy Bodies, Down Syndrome, vascular dementia and Parkinson Dementia. Clinical results demonstrate examples of versatility of cholinergic enhancement.

Acetylcholinesterase↗
PubMed2003

Cholinergic function and Alzheimer's disease.

Deficits in cholinergic function contribute to the pathology of Alzheimer's disease (AD), affecting cognition, behaviour and activities of daily living. Pharmacological intervention directed towards these deficits is based on acetylcholinesterase (AChE) inhibition. Whether such drugs have reached their therapeutic 'ceiling' is an open question and it is possible that cholinergic intervention may be usefully combined with other therapeutic mechanisms. Data relating to such issues are still being collected. In severe AD, levels of AChE and choline acetyltransferase are decreased by as much as 90% compared with normal, whilst butyrylcholinesterase (BuChE) increases. In such instances, it is possible that BuChE may be a more appropriate therapeutic target. Both AChE and BuChE are aggregated in senile plaques along with beta-amyloid, and investigations are being undertaken to determine whether drugs can be developed that inhibit AChE whilst also acting on beta-amyloid. Deficits in nicotinic binding sites have led to hopes for new nicotinic drugs. Cholinergic therapies can potentially cause unwanted side effects and the search for the 'ideal' inhibitor continues. Combinations of drugs may ultimately prove to be the most productive means of treating patients with AD.

Aged↗
PubMed2003

Cholinesterases: new roles in brain function and in Alzheimer's disease.

The most important therapeutic effect of cholinesterase inhibitors (ChEI) on approximately 50% of Alzheimer's disease (AD) patients is to stabilize cognitive function at a steady level during a 1-year period of treatment as compared to placebo. Recent studies show that in a certain percentage (approximately 20%) of patients this cognitive stabilizing effect can be prolonged up to 24 months. This long-lasting effect suggests a mechanism of action other than symptomatic and cholinergic. In vitro and in vivo studies have consistently demonstrated a link between cholinergic activation and APP metabolism. Lesions of cholinergic nuclei cause a rapid increase in cortical APP and CSF. The effect of such lesions can be reversed by ChEI treatment. Reduction in cholinergic neurotransmission--experimental or pathological, such as in AD--leads to amyloidogenic metabolism and contributes to the neuropathology and cognitive dysfunction. To explain the long-term effect of ChEI, mechanisms based on beta-amyloid metabolism are postulated. Recent data show that this mechanism may not necessarily be related to cholinesterase inhibition. A second important aspect of brain cholinesterase function is related to enzymatic differences. The brain of mammals contains two major forms of cholinesterases: acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The two forms differ genetically, structurally, and for their kinetics. Butyrylcholine is not a physiological substrate in mammalian brain, which makes the function of BuChE of difficult interpretation. In human brain, BuChE is found in neurons and glial cells, as well as in neuritic plaques and tangles in AD patients. Whereas, AChE activity decreases progressively in the brain of AD patients, BuChE activity shows some increase. To study the function of BuChE, we perfused intracortically the rat brain with a selective BuChE inhibitor and found that extracellular acetylcholine increased 15-fold from 5 nM to 75 nM concentrations with little cholinergic side effect in the animal. Based on these data and on clinical data showing a relation between cerebrospinal fluid (CSF) BuChE inhibition and cognitive function in AD patients, we postulated that two pools of cholinesterases may be present in brain, the first mainly neuronal and AChE dependent and the second mainly glial and BuChE dependent. The two pools show different kinetic properties with regard to regulation of ACh concentration in brain and can be separated with selective inhibitors. Within particular conditions, such as in mice nullizygote for AChE or in AD patients at advanced stages of the disease, BuChE may replace AChE in hydrolizing brain acetylcholine.

Alzheimer Disease↗
PubMed2003

A critical analysis of new molecular targets and strategies for drug developments in Alzheimer's disease.

Alzheimer's disease (AD), a progressive, degenerative disorder of the brain, is believed to be the most common cause of dementia amongst the elderly. AD is characterized by the presence of amyloid deposits and neurofibrillary tangles in the brain of afflicted individuals. AD is associated with a loss of the presynaptic markers of the cholinergic system in the brain areas related to memory and learning. AD appears to have a heterogeneous etiology with a large percentage termed sporadic AD arising from unknown causes and a smaller fraction of early onset familial AD (FAD) caused by mutations in one of several genes, such as the beta-amyloid precursor protein (APP) and presenilins (PS1, PS2). These proteins along with tau, secretases, such as beta-amyloid cleaving enzyme (BACE), and apolipoprotein E play important roles in the pathology of AD. On therapeutic fronts, there is significant research underway in the development of new inhibitors for BACE, PS-1 and gamma-secretase as targets for treatment of AD. There is also a remarkable advancement in understanding the function of cholinesterase (ChE) in the brain and the use of ChE-inhibitors in AD. A new generation of acetyl- and butyryl cholinesterase inhibitors is being studied and tested in human clinical trials for AD. The development of vaccination strategies, anti-inflammatory agents, cholesterol-lowering agents, anti-oxidants and hormone therapy are examples of new approaches for treating or slowing the progression of AD. In addition, nutritional, genetic and environmental factors highlight more effective preventive strategies for AD. Developments of early diagnostic tools and of quantitative markers are critical to better follow the course of the disease and to evaluate different therapeutic strategies. In this review, we attempt to critically examine recent trends in AD research from molecular, genetic to clinical areas. We discuss various neurobiological mechanisms that provide the basis of new targets for AD drug development. All these current research efforts should lead to a deeper understanding of the pathobiochemical processes that occur in the AD brain in order to effectively diagnose and prevent their occurrence.

Alzheimer Disease↗
PubMed2002

Inhibition of acetyl- and butyryl-cholinesterase in the cerebrospinal fluid of patients with Alzheimer's disease by rivastigmine: correlation with cognitive benefit.

Cholinesterase (ChE) inhibition represents the most efficacious treatment approach for Alzheimer's disease (AD) to date. This multiple-dose study has examined the relationship between inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities in the cerebrospinal fluid (CSF) and cognitive change (measured by the Computerised Neuropsychological Test Battery [CNTB]) following administration of the ChE inhibitor, rivastigmine (Exelon). In 18 patients with mild to moderate AD, CNTB scores, activities of AChE and BuChE in the CSF, and plasma BuChE activity were determined prior to treatment with rivastigmine. Doses of rivastigmine were then titrated (1 mg b.i.d./week) to final doses of 1, 2, 3, 4, 5 or 6 mg b.i.d. (n = 3 per dose). Following treatment with the target dose of rivastigmine for at least 3 days, CNTB scores were re-determined. CSF samples were continuously collected together with plasma samples prior to and for 12 hours after the final dose of rivastigmine, and AChE and BuChE activities determined.AChE in CSF and BuChE in plasma were dose-dependently inhibited by rivastigmine treatment. The inhibition of BuChE in CSF was not clearly dose-dependent. A statistically significant correlation was observed between the change in CNTB summary score and inhibition of AChE activity (r = -0.56, p < 0.05) and BuChE activity (r = -0.65, p < 0.01) in CSF. Improvement in speed-, attention- and memory-related subtests of the CNTB correlated significantly with inhibition of BuChE but not AChE activity in CSF. Weak or absent correlation with change in cognitive performance was noted for inhibition of plasma BuChE. These results indicate that cognitive improvement with rivastigmine in AD is associated with central inhibition of ChEs and support a role for central BuChE in addition to AChE inhibition in modulating cholinergic function in AD.

Acetylcholinesterase↗