The Ca2(+)-dependent neutral proteases calpain I and II as well as their specific inhibitor, calpastatin, were isolated from normal and Alzheimer-degenerated frozen human brain tissue. In the Alzheimer group calpain I activity was higher in cortex than in mesencephalon. The calpastatin activity was lower in cortex in both groups. This may implicate a higher Ca2(+)-dependent proteolysis in cortex compared to mesencephalon. In the Alzheimer group the cortical calpain II level decreased with an increasing degree of neuropathological changes. In the control group, the level of calpastatin decreased as the number of plaques and tangles increased. Evidence was obtained for a correlation of net calpain activity and the extent of neuropathological changes in cortex.

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Significance of decreased lumbar CSF levels of HVA and 5-HIAA in Alzheimer's disease.

The monoamine metabolites homovanillic acid (HVA), 5-hydroxy-indoleacetic acid (5-HIAA) and 4-hydroxy-3-methoxy-phenylglycol (HMPG) were determined in lumbar cerebrospinal fluid (CSF) of 123 patients with Alzheimer's disease (AD) and 57 healthy controls. Despite CSF sampling under strictly standardized conditions, a wide variability in values among both patients and controls was found, as well as fluctuations in repeated samples from individual patients. This suggests that several unknown factors influence the lumbar CSF levels of monoamine metabolites. The AD group showed significantly lower mean levels of HVA (p less than 0.0001) and 5-HIAA (p less than 0.0001) than the control group. A relation between severity of disease and HVA was also found. The widespread neurotransmitter disturbance in AD, together with the nonspecificity of reduced lumbar HVA and 5-HIAA levels, suggests that the changes are nonspecific, secondary to the cerebral degeneration in AD.

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Increased proteolytic activity in lymphocytes from patients with early onset Alzheimer's disease.

The levels of calpains (m-calpain and mu-calpain) in peripheral blood lymphocytes from patients with Alzheimer's disease were determined via Western blotting. The Ca-dependent proteolytic activity and the calpastatin activity were estimated using incubation with exogenous substrate. Evidence was obtained for an increased Ca-dependent proteolytic activity in lymphocytes from patients with early onset Alzheimer's disease. There was also an increased level of membrane-bound mu-calpain in this group of patients. The observed changes may be caused by a general dysregulation of Ca homeostasis in peripheral cells of early onset Alzheimer victims.

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Drugs that induce delirium.

Drug-induced delirium is often seen in clinical practice. Most knowledge about delirium-inducing drugs comes from reports on side effects, and few systematic studies have been done in the field. Delirium is strongly associated with anticholinergic activity; drugs of different classes, including tricyclic antidepressants and traditional high-dose neuroleptics, constitute a high-risk group. A large number of drugs, including benzodiazepines, sedatives, dopamine-activating drugs, antiepileptics, histamine H2 receptor blockers, digitalis and analgesics, are less frequently associated with delirious reactions and constitute a medium-high-risk group. Some of these drugs do not have anticholinergic effects but in vitro have shown to bind to muscarine receptors. The risk of inducing delirium in frail elderly and demented persons clearly suggests that drugs which might induced delirium should be avoided.

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Treatment of Alzheimer's disease with clioquinol.

As heavy metal ions may be implicated in the formation of senile plaques in Alzheimer-afflicted brains, treatment with clioquinol was tested in 20 patients with Alzheimer's disease. Clioquinol is a chelator that crosses the blood-brain barrier and has greater affinity for zinc and copper ions than for calcium and magnesium ions. Treatment was given for 21 days at doses of 20 mg/day to 10 patients and 80 mg/day to another 10 patients. The study was blind to the dosages but included no controls. Cerebrospinal fluid (CSF) investigations revealed a significant increase at day 7 and a decrease at day 21 in Tau protein and growth-associated protein (GAP43). These proteins are increased in Alzheimer's disease and considered as rather stable markers. The initial increase may indicate a temporary cytotoxicity to the brain and/or an increased release into the CSF from stores in the tissue, possibly from senile plaques where the proteins are accumulated. The levels of CSF-Tau protein correlated positively and significantly with the serum levels of copper and also with the serum copper/zinc ratio. Clinical ratings showed slight improvement after 3 weeks treatment with clioquinol in this open study.

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Intracerebroventricular administration of GM1 ganglioside to presenile Alzheimer patients.

We have conducted a preliminary study of the optimum conditions for a therapeutic effect of ganglioside GM1 in Alzheimer's disease. Five patients with the early onset form of Alzheimer's disease (AD type I) received the ganglioside by intracerebroventricular administration for 12 months. Bilateral stereotactic punction of the frontal horns of the ventricular system was performed, and shunt catheters were implanted and connected to a programmable pump. The optimum GM1 dose varied between 20 and 30 mg/24 h. Neurological neuropsychological, psychiatric and neurochemical examinations were performed 7 days before surgery and on days 30, 90, 180 and 360. No patient found the surgery difficult and no patient or relative regretted that they participated in the study. The patients became more active and safer in relation to others and to performance of various activities from day 90. The cerebrospinal fluid level of the monoamine metabolites homovanillic acid and 5-hydroxyindoleacetic acid and the neuropeptide somatostatin increased.

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The neurochemistry of vascular dementia.

Vascular dementia (VAD) is cognitive impairment caused by changes in the blood circulation of the brain. It is not synonymous with multi-infarct dementia. The latter is a subgroup of VAD. Neurochemical investigations of noninfarcted brain tissue from patients with VAD show general changes in VAD brains. The serotonin metabolism is severely reduced and so is the activity of choline acetyltransferase. Monamine oxidase B is significantly increased in the white matter. A severe decrease in myelin components indicates white matter disturbances of such a degree that they must be considered to be of pathogenetic importance. The levels of some neuropeptides in the hypothalamus are increased. This is a finding which is in agreement with clinical findings of a high activity in the hypothalamic-pituitary-adrenal axis in patients with VAD. This high activity is possibly due to a loss of serotonergic inhibitory tone on the hypothalamus in VAD brains.

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Relationship between mental impairment and HPA axis activity in dementia disorders.

In 40 patients with Alzheimer's disease (AD, < 65 years), 56 patients with senile dementia of the Alzheimer type (SDAT, > or = 65 years) and 45 patients with vascular dementia (VAD), basal cortisol levels were estimated and the dexamethasone test (DST) was performed. The degree of dementia was assessed according to DSM-III-R and the GBS scale was used for quantitative measures of functional impairment. There were no significant differences in basal cortisol levels. Especially in the VAD group, scores on functional impairment correlated significantly with post-DST cortisol levels. The results indicate hypothalamic overactivity in demented patients which can be correlated to the degree of dementia. In VAD, and to a certain extent also in SDAT, there appears to be a disconnection between cortical areas, including the hippocampus and the hypothalamus.

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