Loss of Dopamine D2 Receptors in Alzheimer's Disease with Parkinsonism But Not Parkinson's or Alzheimer's Disease

Cholinergic Drugs for Alzheimer's Disease Enhance in Vitro Dopamine Release

“…A range of neuropsychiatric symptoms, including anxiety, depression, apathy, and psychosis, are influenced by dopaminergic systems (Assal and Cummings, 2002;Erkinjuntti, 2002). Furthermore, parkinsonian symptoms commonly accompany AD (Tyrrell et al, 1990;Joyce et al, 1998;Werber and Rabey, 2001), and Parkinson's disease is often linked with depression or dementia. There also is profound loss of DA neurons in dementia with Lewy bodies (Walker et al, 2002;Galvin et al, 2001).…”

“…The noncognitive aspects of dementia usually arise from the dysfunction of the serotonergic and dopaminergic systems rather than the cholinergic systems (Assal and Cummings, 2002;Erkinjuntti, 2002). The dopaminergic systems are further implicated because parkinsonian indications are present in more than 30% of patients with AD (Tyrrell et al, 1990;Joyce et al, 1998); in dementia with Lewy bodies, dopaminergic neurons are lost, leading to a 40 to 70% decline in striatal dopamine (DA) (Walker et al, 2002).…”

Limited Additive Value of Pleural Fluid Carcinoembryonic Antigen Level in Malignant Pleural Effusion

“…In a recent report from Foresti et al [16], CEA.PF yielded a sensitivity of 0.70 in 70 patients with adenocarcinomas although the overall sensitivity was 0.62 in their series. Additionally, Salama et al [17]found a CEA.PF sensitivity of 0.72 in 76 patients with carcinomatous pleural effusions. Considering this wide variation in sensitivity, there is a scope for each laboratory to evaluate the use of CEA.PF among the population of interest.…”

“…Recent reports [17, 18]have shown CEA.PF to be useful in distinguishing adenocarcinomas from mesotheliomas, being significantly lower in the latter.…”

Functional Pharmacology in Human Brain

“…In contrast to the cerebral cortex, reduced concentrations of homovanillic acid were observed in postmortem neostriatal tissue of patients with a clinical diagnosis of Alzheimer's disease (Palmer et al, 1984), suggesting a dysfunction in striatal DA transmission. Accordingly, parkinsonian symptoms commonly accompany Alzheimer's disease (Tyrrell et al, 1990;Joyce et al, 1998;Werber and Rabey, 2001). In a recent report (Zhang et al, 2004), it was observed that the use of cholinergic drugs for Alzheimer's disease, in particular the acetylcholinesterase inhibitors donepezil and galantamine, can enhance DA release by indirectly acting at, or allosterically modulating (Svensson and Nordberg, 1996), nicotinic AChRs present on DA terminals, which may underlie the influence of these drugs over some noncognitive symptoms of Alzheimer's disease, including motor dysfunctions.…”