Biomedical subjects

J M Gandon

Publications and source records attributed to J M Gandon.

25 records · Page 2Linked to original sources

PubMed1989

[Experimental verification of the favorable activity of synthetic corticostimulin on brain edema induced by ischemia in rats].

The anti-oedematous effect of tetracosactide (Synacthene Immediate) was studied on a rat brain transient global ischaemia model. Brain oedema was evaluated by proton nuclear magnetic resonance, with measurement of T1 and T2 relaxation times in the cortex and white matter. The effective kinetic dose of tetracosactide was 0.4 mg/kg, and a comparison of the results obtained with those observed after treatment with dexamethasone 13 mg/kg confirmed that both drugs may be regarded as potent anti-oedematous agents, but there was nothing in this study to suggest that the mechanism of action of tetracosactide was different from that of corticosteroids.

Animals↗

PubMedDate not supplied

Drugs used in Alzheimer's disease and neuroplasticity.

Drugs indicated for use in Alzheimer's disease (AD) must clinically improve the cognitive symptomatology of the disorder, although nonexclusively. From a neurochemical standpoint, these drugs must oppose the multiple processes recognized as stigmata of AD. In these two ways, so-called AD drugs may be considered substances modifying cerebral plasticity. Long-term evaluation of anticholinesterases and of tacrine, in particular, provides arguments in support of this initially purely biologic, theoretical approach. This concept of neuroplasticity applied to dementia may modify the traditional pharmaceutical drug development programs.

Alzheimer Disease↗

PubMedDate not supplied

Aminotransferase levels and silymarin in de novo tacrine-treated patients with Alzheimer's disease.

BACKGROUND: Silymarin is a well-known hepatoprotective agent. Tacrine, the first drug marketed for Alzheimer's disease (AD), induces an elevation of serum liver transaminase prohibiting an effective dosage in many patients. This 12-week randomised, double-blind, placebo-controlled study was undertaken to evaluate the ability of silymarin to antagonise or prevent the hepatotoxic effects of tacrine and to analyse its action on tacrine efficacy and tolerability. METHODS: Outpatients suffering from mild-to-moderate dementia of the Alzheimer type were randomly assigned to two treatment groups: tacrine + silymarin and tacrine + placebo. The study was double-blind for silymarin and open for tacrine and was conducted in 22 French neurology and geriatric centres. Silymarin (420 mg/day) was given first (1 week) and tacrine was added at 40 mg/day for 6 weeks, then increased to 80 mg/day (6 weeks). Serum ALAT was the main evaluation criterion (> upper limit of normal, ULN). Serum ASAT as well as adverse side effects and cognitive performance assessed by MMSE and the Syndrome Kurtz test (SKT) were secondary evaluation criteria. Null hypotheses were evaluated with Fisher's exact test. FINDINGS: 222 patients were recruited and received silymarin and tacrine (110 patients) or placebo and tacrine (112 patients). 28 patients dropped out; 217 were included in the intent-to-treat analysis. No statistical difference was observed between the two groups for serum ALAT (p = 0.39). Fewer patients had ALAT levels >5 ULN in the silymarin group (-33.3%). Side effects and notably gastrointestinal disorders were much less frequent in the silymarin group. Cognitive performance remained unchanged in both groups. INTERPRETATION: Silymarin does not prevent tacrine-induced ALAT elevation but does reduce the rate of gastrointestinal and cholinergic side effects without any impact on cognitive status. As a consequence, silymarin (420 mg/day) could be co-administered with tacrine to improve tolerability in the initial phases of AD treatment.

Aged↗

PubMedDate not supplied

Procedural memory and Parkinson's disease.

A detailed analysis of the mnestic deficits associated with Parkinson's disease (PD) contributes to explaining the cognitive disorders and their well documented consequences. This study was designed to show that, in PD declarative as well as procedural memory is severely impaired. Three tests designed to explore this aspect of mnestic functioning were proposed to a group of 16 parkinsonian patients whose motoricity was controlled: inverted reading, braille reading, sound form association. The results obtained, compared with those of young and aged controls, show that PD is associated with marked deficits in both declarative and procedural memory. Declarative memory impairment was similar to that observed in the control population (healthy elderly subjects, age-matched with the PD patients) but more marked in PD subjects. The procedural memory deficit was linked with age and pathology. Procedural memory involves a variety of processing modules dedicated to the type of information (visual, auditive, tactile codes). The deficits observed were more like a loss of automatism than procedural impairment stricto sensu ('knowing how'). It would be worth pursuing research by studying akinesia and motor disorders from the angle of automatic memory impairment.

Adult↗

PubMedDate not supplied

Effect of two doses of ginkgo biloba extract (EGb 761) on the dual-coding test in elderly subjects.

The subjects of this double-blind study were 18 elderly men and women (mean age, 69.3 years) with slight age-related memory impairment. In a crossover-study design, each subject received placebo or an extract of Ginkgo biloba (EGb 761) (320 mg or 600 mg) 1 hour before performing a dual-coding test that measures the speed of information processing; the test consists of several coding series of drawings and words presented at decreasing times of 1920, 960, 480, 240, and 120 ms. The dual-coding phenomenon (a break point between coding verbal material and images) was demonstrated in all the tests. After placebo, the break point was observed at 960 ms and dual coding beginning at 1920 ms. After each dose of the ginkgo extract, the break point (at 480 ms) and dual coding (at 960 ms) were significantly shifted toward a shorter presentation time, indicating an improvement in the speed of information processing.

Aged↗

PubMedDate not supplied

[Study of correlations between self-estimation of memory, psychometric test (SM9) and test of memory in daily life].

Assessment of memory performance is now well established. However, the normal form of assessment does not evaluate memory problems encountered during daily activities, a situation relevant to the evaluation of drug effects on memory components. The present study examines the ecological validity of psychometric tests. 49 individuals, from 20 to 89 years old without any identified pathology were included in the study, with the aim of establishing correlations between an autoquestionnaire of memory, a standard memory battery (SM9) and a daily memory video test (DMV). No correlation was found between self-estimation and objective tests or DMV. A strong correlation (r = 0.81) was found between SM9 and DMV. Imaged information and verbal coding appear to be essential parameters of objective tests. These results confirm the ecological validity of the objective psychometric tests and in particular of SM9.

Adult↗

PubMedDate not supplied

[Randomized double-blind comparative study of minaprine (200mg/j) and of placebo on memory loss].

Thirty five subjects (age: 45-69 years) with subjective memory loss, without any other neuropsychiatric or somatic disease, were recruited in a phase II study. This double blind randomized versus placebo controlled study compared the effects of minaprine (200 mg/d) with placebo, in two parallel groups, during 2 months, on memory, attention and vigilance. Three psychometric tests were the main criteria of assessment: a standardized battery of memory tests (SM 5), the dual-coding test, the analysis of choice reaction times (CRT) and the critical flicker fusion point (CFF). A positive effect of minaprine was detected on words delayed recall (p = 0.028) and immediate recognition of words (p = 0.049). The global clinical tests (CGI, MacNair scale) were not statistically modified. Tolerability of minaprine and placebo were comparable. A positive pharmacodynamic activity on mnemonic performance is thus demonstrated in favour of minaprine (200 mg/d) in this specific population characterized by a memory complaint. These results would lead to a phase III study in which the main criteria would be global scales in order to confirm the clinical reliability of the present results.

Aged↗