Search results for "DECLINE"

Microvascular brain damage with aging and hypertension

2011

Loss of cognitive function and hypertension are two common conditions in the elderly and both significantly contribute to loss of personal independency. Microvascular brain damage - the result of age-associated alteration in large arteries and the progressive mismatch of their cross-talk with small cerebral arteries - represents a potent risk factor for cognitive decline and for the onset of dementia in older individuals. The present review discusses the complexity of factors linking large artery to microvascular brain disease and to cognitive decline and the evidence for possible clinical markers useful for prevention of this phenomenon. The possibility of dementia prevention by cardiovasc…

2021

Introduction: Functional imaging studies have demonstrated the recruitment of additional neural resources as a possible mechanism to compensate for age and Alzheimer’s disease (AD)-related cerebral pathology, the efficacy of which is potentially modulated by underlying structural network connectivity. Additionally, structural network efficiency (SNE) is associated with intelligence across the lifespan, which is a known factor for resilience to cognitive decline. We hypothesized that SNE may be a surrogate of the physiological basis of resilience to cognitive decline in elderly persons without dementia and with age- and AD-related cerebral pathology.Methods: We included 85 cognitively normal…

Postprandial Hyperglycemia Is Associated With White Matter Hyperintensity and Brain Atrophy in Older Patients With Type 2 Diabetes Mellitus

2018

Type 2 diabetes mellitus is associated with neurodegeneration and cerebrovascular disease. However, the precise mechanism underlying the effects of glucose management on brain abnormalities is not fully understood. The differential impacts of glucose alteration on brain changes in patients with and without cognitive impairment are also unclear. This cross-sectional study included 57 older type 2 diabetes patients with a diagnosis of Alzheimer's disease (AD) or normal cognition (NC). We examined the effects of hypoglycemia, postprandial hyperglycemia and glucose fluctuations on regional white matter hyperintensity (WMH) and brain atrophy among these patients. In a multiple regression analysi…

Allosteric modulation of nicotinic receptors as a treatment strategy for Alzheimer's disease.

2000

Impairment of the central cholinergic system has a pivotal role in the cognitive decline observed in patients with Alzheimer’s disease (AD). One of the most prominent cholinergic deficits is the reduced number of nicotinic acetylcholine receptors (nAChR) in the brain. Since these receptors are important for memory and learning, enhancing nicotinic neurotransmission is a promising treatment strategy for AD. The two most common approaches to correcting these cholinergic deficits are to increase the synaptic availability of acetylcholine (ACh) by inhibiting acetylcholinesterase (AChE), or to mimic the effects of ACh (nicotinic agonists) by acting directly on nicotinic receptors. Clinical studi…

Computational Analysis of the Active Control of Incompressible Airfoil Flutter Vibration Using a Piezoelectric V-Stack Actuator

2021

The flutter phenomenon is a potentially destructive aeroelastic vibration studied for the design of aircraft structures as it limits the flight envelope of the aircraft. The aim of this work is to propose a heuristic design of a piezoelectric actuator-based controller for flutter vibration suppression in order to extend the allowable speed range of the structure. Based on the numerical model of a three degrees of freedom (3DOF) airfoil and taking into account the FEM model of a V-stack piezoelectric actuator, a filtered PID controller is tuned using the population decline swarm optimizer PDSO algorithm, and gain scheduling (GS) of the controller parameters is used to make the control adapti…

Is the painted frog Discoglossus pictus a declining species in Italy? On the reliability of a distributional atlas approach

2013

The conservation status of amphibians is often assessed using public databases because of a lack of up-to-date field data. However, it is crucial that this kind of data is used carefully, evaluating the reliability and the consistency of the information. In Italy, the conservation status of the painted frog, Discoglossus pictus, was recently assessed using public databases, and the outcome highlighted a worrying situation for the species. We analyzed the reliability of these conclusions and reassessed the status of the painted frog, taking into account its insular distribution and new data of species occurrence. Our results contrast with the previous analysis and show how an incautious use …

Counter-Clock World: How Planning Backwards Helps in Moving Forward in Collapsing Environments

2021

Research on corporate decline and turnarounds as well as the strategic use of history have so far remained two separate research fields. We integrate these two fields with a thought experiment, proposing ways in which strategists can work with, and through time in managing and turning around declines. Our thought experiment involves two very different types of analogies: a textual one from Philip K. Dick’s science fiction novels, on the one hand, and a visual one from Einsteinian relativity science, on the other hand. Inspired and informed by these different conceptualizations of the past and time, we develop four forms of backward strategizing to successfully manage a struggling corporatio…

Gender-related effect of clinical and genetic variables on the cognitive impairment in multiple sclerosis

2004

BACKGROUND: Cognitive impairment may occur at any time during the course of multiple sclerosis (MS), and it is often a major cause of disability in patients with the disease. The APOE-epsilon4 allele is the major known genetic risk factor for late onset familial and sporadic Alzheimer's Disease (AD), and it seems to be implicated in cognitive decline in normal elderly persons. OBJECTIVE: To investigate the clinical and genetic variables that can be associated with the cognitive decline in patients with MS. METHODS: Five-hundred and three patients with clinically definite MS underwent a battery of neuropsychological tests and, according to the number of failed tests, were divided into cognit…

Apolipoprotein E polymorphism is associated with both senile plaque load and Alzheimer-type neurofibrillary tangle formation.

1996

Recent work provided evidence that the apolipoprotein (apo) E polymorphism is associated with late-onset sporadic Alzheimer's disease. The major histological hallmarks of Alzheimer's disease are the extraneuronal deposition of A4/beta-amyloid and the intraneuronal formation of neurofibrillary tangles, the latter correlating strongly with the psychometric status. We examined the relationship between the apo E polymorphism and Alzheimer's disease-related histological changes using a staging system which accounts for the progression of the disease over time and correlates well with the cognitive decline ante mortem. We observed a significant positive correlation between both neurofibrillary ch…

Apolipoprotein E polymorphism influences not only cerebral senile plaque load but also Alzheimer-type neurofibrillary tangle formation.

1995

Only recently, evidence was provided that apolipoprotein E allele epsilon 4 located on Chromosome 19 is associated with late onset (i.e. senile) sporadic Alzheimer's disease. Histologically, Alzheimer's disease is associated with intraneuronal neurofibrillary changes and extraneuronal A4/beta-amyloid deposition. We set out with a histological staging system which considers the gradual development of Alzheimer's disease-related histological changes over time and correlates highly with the cognitive decline ante mortem. Our analysis revealed that both the mean stage for A4/beta-amyloid deposits and the mean stage for neurofibrillary tangles get significantly shifted upwards in epsilon 4-carri…