Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002395 (Alzheimer's disease)
 110,584 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ten patients with severe dementia due to Alzheimer's disease (AD) or multi-infarct dementia (MID) or both, were treated with the precursor amino acids of the neurotransmitters serotonin and dopamine. The precursor amino acids (PAA) were given orally in a preparation that included tyrosine (4 gm daily) and 5-hydroxy-tryptophan (5-HTP) (800 mg daily), plus carbidopa (100 mg daily) as an aromatic amino-acid decarboxylase inhibitor. Diagnosis was established by an electroencephalogram, brain scan, computerized axial tomographic scan, and in one case by necropsy findings. Serial clinical evaluations and measurements of neuropsychologic function were performed. Levels of homovanillic acid (HVA) and 5-hydroxyindole-acetic acid (5-HIAA) were determined before and after administration of probenecid. Side effects of the PAA therapy were diarrhea, drowsiness, nausea, vomiting and agitation, all of which were controlled by reducing the dosage. One patient with MID and one with AD+MID showed clinical and psychologic improvement, but the others did not improve. Analysis of the cerebrospinal fluid for HVA and 5-HIAA before and after the probenecid test indicated some improvement in the metabolic turnover of these acid metabolites of serotonin and dopamine after administration of their precursor amino acids.
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PMID:Neurotransmitter precursor amino acids in the treatment of multi-infarct dementia and Alzheimer's disease. 30 Nov 48

The availability of radiolabelled ligands selective for various putative neurotransmitter receptor sites and the development of quantitative autoradiography has led to a greater understanding of the neuronal pathway and receptor subtypes involved in the vomiting reflex induced by various mechanisms both within the central nervous system and the periphery. Receptors for acetylcholine, dopamine, histamine and serotonin have been detected in a number of brain regions associated with the vomiting reflex, and provide a rational basis for the antiemetic action of drugs that inhibit receptor subtypes for these neurotransmitters. The basis of the antiemetic action of other drugs such as dexamethasone and the cannabinoids is still obscure. Some drugs act on more than 1 receptor subtype. Metoclopramide may inhibit both dopamine D2- and 5-HT3 receptors in producing its antiemetic effect. Both metoclopramide and domperidone appear to have additional peripheral actions that contribute to their effectiveness. The cannabinoids are effective in cytotoxic-induced vomiting, perhaps acting via endorphin receptors or by inhibiting prostaglandin synthesis. The effectiveness of 5-HT3 receptor antagonists may depend on the block of both central and peripheral neuronal 5-HT3 receptors. Vomiting constitutes a major disadvantage to the use of many drugs; vomiting induced by aminoglycoside antibiotics appears to be due to ototoxicity and is relieved by histamine H1-receptor antagonists. The protracted vomiting associated with the use of some cytotoxics in cancer chemotherapy may involve psychic components, the chemoreceptor trigger zone and peripheral sensory neurons. Both 5-HT3 and dopamine D2-receptor antagonists exert some control, the former being more effective with cytotoxics of high emetogenic potential, such as cisplatin. Serotonin 5-HT3 receptor antagonists or high doses of metoclopramide in combination with anxiolytics and steroids as well as greater attention to pharmacokinetic profiles of the drugs involved would appear to offer improved control. The use of dopamine receptor antagonists in controlling emesis induced by dopamine agonists used in Parkinson's disease poses theoretical problems which can be overcome by using drugs with selectivity for the chemoreceptor trigger zone, such as domperidone or metoclopramide. However, higher doses of these drugs may produce some impairment of therapeutic responses to the agonists. Muscarinic and nicotinic agonists currently under investigation in Alzheimer's disease pose another therapeutic dilemma as emesis is due to a central action of these compounds. Several sites may be involved including the chemoreceptor trigger zone and frontal lobes. Opiates may act through dopamine receptors or mu-receptors on dopaminergic nerves, but serotonergic mechanisms may also be involved in the action of some opiates.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Pharmacological agents affecting emesis. A review (Part I). 137 16

The serotonin 5-HT3 receptor antagonist effects of DAT-582, the (R) enantiomer of AS-5370 ((+/-)-N-[1-methyl-4-(3-methyl-benzyl)hexahydro-1H-1,4-diazepin-6- yl]-1H- indazole-3-carboxamide dihydrochloride), and its antipode were compared with those of AS-5370 and existing 5-HT3 receptor antagonists. In anesthetized rats, DAT-582 antagonized 2-methyl-5-HT-induced bradycardia with an ED50 value of 0.25 microgram/kg i.v., whereas the (S) enantiomer was without effect even at 1000 micrograms/kg i.v. In antagonizing the bradycardia, DAT-582 was as potent as granisetron, slightly more potent than AS-5370, and 2, 5 and 18 times more potent than ondansetron, ICS 205-903 and renzapride, respectively, although it was less potent than zacopride. DAT-582 inhibited cisplatin (10 mg/kg i.v.)-induced emesis in ferrets with an ED50 value of 3.2 micrograms/kg i.v. twice. The antiemetic activity of DAT-582 was more potent than that of the existing 5-HT3 receptor antagonists examined, except zacopride. In contrast, the (S) enantiomer had little effect at 1000 micrograms/kg i.v. twice. In isolated guinea-pig ileum, DAT-582 inhibited 5-HT-induced contractions with an IC50 value of 91 nM, whereas the (S) enantiomer hardly inhibited them even at 1000 nM. These results suggest that DAT-582, the (R) enantiomer of AS-5370, potently and selectively blocks 5-HT3 receptors.
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PMID:5-HT3 receptor antagonist effects of DAT-582, (R) enantiomer of AS-5370. 142 31

The antiemetic effects of a novel serotonin3 receptor antagonist, DAT-582 [(6R)-(-)-N-[1-methyl-4-(3-methylbenzyl)hexahydro-1H-1,4- diazepin-6-yl]-1H-indazole-3-carboxamide dihydrochloride] were compared with those of the existing serotonin3 receptor antagonists, ondansetron and granisetron, in experimental animals. In ferrets, DAT-582 (0.003-0.1 mg/kg i.v. twice) dose-relatedly prolonged the latency to the first emetic episode and decreased the number of emetic episodes induced by cisplatin (10 mg/kg i.v.). DAT-582 was more potent than ondansetron or granisetron in inhibiting the emesis. The emesis induced by cyclophosphamide (150 mg/kg i.v.), doxorubicin (15 mg/kg i.v.) or combination of cisplatin (3.3 mg/kg i.v.), cyclophosphamide (50 mg/kg i.v.) and doxorubicin (5 mg/kg i.v.) was also inhibited by DAT-582 (0.1 mg/kg i.v., twice). When administered 2 hr before cisplatin in ferrets, DAT-582 decreased markedly the number of emetic episodes induced by cisplatin at 0.1 mg/kg i.v., whereas ondansetron and granisetron were without effect even at 0.3 mg/kg i.v. DAT-582 (0.1 mg/kg i.v.), when administered in the ferrets which were vomiting after cisplatin, immediately and almost completely blocked the subsequent emesis. Furthermore, DAT-582 (0.1 mg/kg i.v.) completely inhibited the cisplatin (3 mg/kg i.v.)-induced emesis for 24 hr after cisplatin in three of five dogs. In addition, DAT-582, at 0.3 and 1 mg/kg, p.o., inhibited the cisplatin-induced emesis in dogs. However, DAT-582, even at 3 mg/kg s.c., did not inhibit the apomorphine (0.3 mg/kg,, s.c.)-induced emesis in dogs, or the nicotine-, copper sulfate- or motion stimulus-induced emesis in the house musk shrew, Suncus Murinus.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:DAT-582, a novel serotonin3 receptor antagonist, is a potent and long-lasting antiemetic agent in the ferret and dog. 153 32

A randomized, double-blind, placebo-controlled, parallel-group clinical trial was carried out to compare 24-week periods of treatment with 1 g acetyl-l-carnitine twice daily and placebo in the treatment of patients with dementia of the Alzheimer type. A total of 36 patients entered the trial, of whom 20 patients (7 active, 13 placebo) completed the full 24 weeks. Whilst several of the efficacy indices showed little change in either group during the trial, there was an apparent trend for more improvement in the acetyl-l-carnitine group in relation to the Names Learning Test and a computerized Digit Recall Test, both related to aspects of short-term memory. Similarly, there was a trend for reaction time in the computerized classification test to show less deterioration in the active treatment group. Changes within groups, and changes between groups, failed to reach statistical significance, at least partially because of the small number of patients available for analysis. Two indices of overall therapeutic benefit showed a trend for less deterioration in the active-treatment group than in the placebo group. Nausea and/or vomiting occurred in 5 patients in the acetyl-l-carnitine group. Laboratory tests revealed no signs of drug toxicity. The results suggest that acetyl-l-carnitine may have a beneficial effect on some clinical features of Alzheimer-type dementia, particularly those related to short-term memory.
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PMID:Double-blind, placebo controlled study of acetyl-l-carnitine in patients with Alzheimer's dementia. 217 69

HP 029 (1,2,3,4-tetrahydro-9-aminoacridin-1-oL-maleate), an oral anticholinesterase, enhances memory in rodents and may be useful in treating Alzheimer's disease (AD). To assess adverse events in relation to dosage and plasma drug levels, 24 hospitalized AD subjects were randomly assigned to receive placebo or HP 029 for 10 days in a double-blind, sequential escalation study. Maximum daily dosages were 450 mg (group 1), 300 mg (group 2), and 225 mg (group 3), divided into three doses per day. The group 1 trial was discontinued on day 5 because one subject, 6 hours following the second of three scheduled 150-mg doses, had a tonic seizure after protracted vomiting and hyperventilation; adverse events in other patients included nausea, vomiting, abdominal cramps, diarrhea, dizziness, and syncope. Adverse events were generally less severe in group 2, but only two of six HP 029 subjects could complete the trial at 300 mg/day. All group 3 subjects completed the trial at 225 mg/day with drug related, mild adverse events (nausea, vomiting, lacrimation, rhinorrhea) in only two subjects. Although mean plasma drug levels were related to adverse events across dosage groups, they did not adequately predict the occurrence or severity of adverse events in individual subjects. The 225 mg/day dose appears to be safe for use in multicenter outpatient trials of HP 029 efficacy in AD. Further patient studies are ongoing to determine the relation of specific subject characteristics to the metabolic profile of HP 029 and biological response.
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PMID:Clinical safety, tolerance, and plasma levels of the oral anticholinesterase 1,2,3,4-tetrahydro-9-aminoacridin-1-oL-maleate (HP 029) in Alzheimer's disease: preliminary findings. 235 6

Alzheimer's disease is a degenerative brain disorder with a progressive dementia which develops in middle or late life. The pathological findings of this disease are characterized by neurofibrillary tangles, senile plaques and cerebrovascular amyloidosis. However, cerebral hemorrhage caused by amyloid angiopathy rarely occurs. A 71-year-old woman, who had been suffering from an impairment of her cognitive ability for the past several months, suddenly developed a severe headache with vomiting and gait disturbance. Brain CT disclosed a hemorrhagic lesion in the right parieto-occipital region. In the following two years she had experienced two episodes of the similar subcortical hemorrhage which occurred in the right parietal lobe and bilateral parieto-occipital regions. She died at the age of 73. Histopathological examinations of the brain revealed a decreased number of neurons with diffuse distribution of senile plaques and neurofibrillary tangles in the neocortex and hippocampus. Severe cerebrovascular amyloid deposits were also seen. Immunostaining for amyloid was carried out using a monoclonal antibody to amyloid beta protein. The senile plaque and cerebrovascular amyloid was strongly immunoreactive to anti-beta protein antibody. Cerebral amyloid angiopathy is commonly seen in the brains with Alzheimer's disease and severe cerebrovascular degeneration secondary to heavy amyloid deposits may cause recurrent subcortical hemorrhages in the patients with this disorder.
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PMID:[An Alzheimer's disease case showing recurrent subcortical hemorrhage: an autopsy findings with immunohistochemical studies of cerebral amyloid deposits]. 280 20

We studied six cases of spongy degeneration of the CNS in infancy among Chinese. The main clinical features were cyclical vomiting and wailing, blindness, megalocephaly, convulsions, lethargy, and coma. Chief findings from light microscopic studies were spongiform change, moderate outfall of neurons, and marked astrocytosis, with formation of Alzheimer's cells type 2. Demyelination was only slight, if present. Electron microscopic studies revealed membrane-bound vacuoles, often containing membranous fragments or blisters and electron-dense granules.
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PMID:Spongy degeneration of the CNS in infancy. 636 28

We have reported that arecoline, a muscarinic receptor agonist replicably enhanced verbal memory in five of nine subjects with Alzheimer's disease (AD). To investigate the mechanism of cognitive improvement, circulating hormone measurements were made during high-dose acute and low-dose chronic intravenous (i.v.) arecoline administration to AD patients. Acute hormone responses were measured during, and for 6 h after, infusion of arecoline 5 mg i.v. over 30 min. Chronic responses were measured in cognitive responders during continuous i.v. infusion of arecoline escalating over 2 weeks (0.5-40 mg/day) and then during a 1 week infusion of the dose optimizing cognition (4-16 mg/day). Acute arecoline administered to 14 subjects produced unpleasant side-effects (e.g. nausea, vomiting), mean adrenocorticotrophic hormone (p = .0006), cortisol (p = .0001) and beta-endorphin (p = .0001) levels were elevated. During chronic arecoline treatment, no side-effects occurred and plasma cortisol, adrenocorticotrophic hormone and beta-endorphin levels were unchanged in nine subjects overall and in five cognitive responders. Thus, high-dose arecoline activates the hypothalamic-pituitary-adrenal (HPA) axis and may increase other anterior pituitary hormone levels, likely representing a 'stress response', but cognition-enhancing, low doses of arecoline do not produce a glucocorticoid response. Hence, arecoline-induced memory improvement is not due to the induction of 'stress' nor to the elevation of peripheral corticosteroid levels.
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PMID:Neuroendocrine responses to intravenous infusion of arecoline in patients with Alzheimer's disease. 858 3

The present study assessed the safety and efficacy of the cholinesterase inhibitor, velnacrine, for treating the cognitive symptoms of Alzheimer's disease. Patients (N = 236) meeting NINCDS-ADRDA criteria for Alzheimer's disease entered a double-blind, placebo-controlled dose-ranging protocol (30, 75, 150, 225 mg/day each for one week) to identify velnacrine responders (> or = four point improvement on the cognitive subscale of the Alzheimer's Disease Assessment Scale [ADAScog]). After a two week drug washout, velnacrine responders were randomly assigned to their best velnacrine dose or placebo in a six week dose-replication protocol employing the ADAScog and the Clinical Global Improvement scale as primary outcome measures. During dose-replication, intent-to-treat analysis revealed that velnacrine patients scored significantly better than placebo patients on the ADAScog after two (p < 0.004), four (p < 0.025) and six (p < 0.001) weeks of treatment. No significant treatment effect on Clinical Global Improvement scores was observed. The primary adverse event was an asymptomatic elevation of liver transaminases found among 28% of the 236 treated patients. Cholinergic side effects including diarrhea (14%), nausea (11%) and vomiting (5%) were observed and 8% of patients experienced skin rash. The present study identified a subgroup of Alzheimer's patients who demonstrated a significant, but modest, improvement during velnacrine treatment on structured cognitive testing.
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PMID:Double-blind placebo-controlled study of velnacrine in Alzheimer's disease. 863 8


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