Search PubMed⌕ Search

Biomedical subjects

C Jeandel

Publications and source records attributed to C Jeandel.

At least 19 recordsLinked to original sources
PubMed1999

Effects of physical and sporting activities on balance control in elderly people.

OBJECTIVE: Balance disorders increase with aging and raise the risk of accidental falls in the elderly. It has been suggested that the practice of physical and sporting activities (PSA) efficiently counteracts these age related disorders, reducing the risk of falling significantly. METHODS: This study, principally based on a period during which the subjects were engaged in PSA, included 65 healthy subjects, aged over 60, who were living at home. Three series of posturographic tests (static, dynamic with a single and fast upward tilt, and dynamic with slow sinusoidal oscillations) analysing the centre of foot pressure displacements or electromyographic responses were conducted to determine the effects of PSA practice on balance control. RESULTS: The major variables of postural control were best in subjects who had always practised PSA (AA group). Those who did not take part in PSA at all (II group) had the worst postural performances, whatever the test. Subjects having lately begun PSA practice (IA group) had good postural performances, close to those of the AA group, whereas the subjects who had stopped the practice of PSA at an early age (AI group) did not perform as well. Overall, the postural control in the group studied decreased in the order AA > IA > AI > II. CONCLUSIONS: The period during which PSA are practised seems to be of major importance, having a positive bearing on postural control. It seems that recent periods of practice have greater beneficial effects on the subject's postural stability than PSA practice only at an early age. These data are compatible with the fact that PSA are extremely useful for elderly people even if it has not been a lifelong habit.

Accidental Falls↗
PubMed1998

[Alzheimer disease. Epidemiology, genetics and physiopathological hypotheses].

RISK FACTORS: Aging is the chief risk factor for Alzheimer's disease (AD). Other risk factors are aluminum in drinking water, diabetes mellitus, head trauma. Protective factors are: higher education, cigarette smoking, nonsteroidal anti-inflammatory drugs and estrogen use. GENETIC FACTORS: Mutations of presenilins 1 and 2 and of the APP gene in families with early-onset AD. Apolipoprotein E polymorphism in late-onset familial and sporadic AD. PATHOGENIC HYPOTHESES: Amyloid deposits in senile plaques and therefore dementia could be due to an overproduction of Abeta (Down's syndrome) or due to the primary (APP mutation) or secondary (role of diabetes, mellitus, apoE polymorphism: protective effect of estrogen) abnormal neurotoxic feature of Abeta. The hyperphosphorylation of tau (a protein which plays a pivotal role in the axonal transport), perhaps regulated by the apoE polymorphism could lead to neurofibrillar degeneration. Neurotoxic mediators produced by the activated microglia (perhaps activated by neuronal damage) and oxidative stress could also be involved in the neurodegeneration.

Age Factors↗
PubMed1998

[Alzheimer disease, markers in the cerebrospinal fluid. Support of physiopathologic hypotheses].

CERTAIN DIAGNOSIS: Because the certainty diagnosis of Alzheimer's disease is defined after autopsy or brain biopsy by the presence of neurofibrillar degeneration (NFD), extracellular senile plaques and vascular deposits of amyloid in the hippocampus amygdalus and the cerebral cortex, some authors have searched for biological ante-mortem markers of AD, particularly in the cerebrospinal fluid (CSF) which is essentially derived from brain tissue. SEARCH FOR MARKERS: Studies have investigated the CSF level of neurotransmitters, neuropeptides, amino acids, trace elements, constituents of NFD and senile plaques in a diagnostic and pathogenic perspective. HOPE FOR DIAGNOSIS: Even though ethical, technical and methodological difficulties met by authors are important and even though many clinical and biological parameters must be taken into account, these studies bring important pathogenic evidence and allow hope that markers of AD which are so necessary for early diagnosis and objective study of therapies will be found.

Alzheimer Disease↗
PubMed1998

Abnormal substrate levels that depend upon mitochondrial function in cerebrospinal fluid from Alzheimer patients.

BACKGROUND: Impaired oxidative and energy metabolism are important features in Alzheimer's disease. These metabolic abnormalities may induce functional disturbances and are associated with significant cognitive impairment. OBJECTIVE: To determine whether mitochondrial function is altered by Alzheimer's disease, a quantitative analysis of substrates that enter the tricarboxylic acid cycle was carried out in cerebrospinal fluid (CSF) from Alzheimer patients. METHODS: Organic acid levels related to carbohydrate oxidation were measured in CSF from patients affected by dementia of Alzheimer type (n = 17) and from nondemented elderly controls (n = 17) using a gas chromatography/mass spectrometry system. CSF glucose and glutamine concentrations were determined by a quantitative enzymatic method and by ion exchange chromatography, respectively. RESULTS: Compared to age-matched controls, patients had a higher CSF level of lactate (p = 0.002) and a lower mean level of succinate (p = 0.002), fumarate (p = 0.003) and glutamine (p = 0.0005). The CSF glucose level was not modified. CONCLUSION: Our results suggest an impairment of mitochondrial oxidative metabolism in brain cells of patients with Alzheimer's disease.

Aged↗
PubMed1998

Measurement of the amounts of elastic fibers in the skin and temporal arteries of healthy aged individuals by automated image analysis.

BACKGROUND: A quantitative study of dermal and arterial elastic fibers as a function of age was carried out by computerized image analysis. OBJECTIVE: We investigated whether any parallelism can be established between the morphometric parameters of elastic fibers from the skin and the temporal artery in elderly subjects. METHODS: we quantitated the skin elastic fibers of the reticular dermis and the elastic fibers of the temporal artery using a specific staining procedure followed by automated image analysis in 16 subjects of age range 63-87 years. RESULTS: There was a good correlation between the area fraction occupied by the elastic fibers in the unexposed skin (inner part of the upper arm) and aging (r = 0.669, p < 0.01). The area fraction occupied by elastic fibers in unexposed skin was correlated with the area fraction occupied by elastic fibers in the deep part of the temporal artery (r = 0.498, p < 0.05). Actinic elastosis affected both tissues, but there was no correlation between the amount of elastotic material in the exposed skin and the area fraction of elastic fibers in the superficial part of the temporal artery. CONCLUSION: We provided evidence that in sun-protected tissues the area fraction occupied by elastic fibers in dermis and deep part of the temporal artery showed a significant correlation. We proposed that skin biopsies were a valuable diagnostic tool for predicting arterial wall abnormalities of elastic fibers.

Aged↗
PubMed1998

[A review of evaluation questionnaires for physical activity].

The need to evaluate or quantify an individual's physical activity often raises the problems of choosing the instrument which most adequately meets the requirements of the study. This article offers a presentation of various questionnaires available in the literature. It proposes a table intended to characterize these questionnaires as well as a summary of validation steps. These tools allow rapid comparisons between questionnaires and are helpful in guiding the user's choice of a well adapted questionnaire.

Exercise↗
PubMed1997

Cerebrospinal fluid apolipoprotein E level is increased in late-onset Alzheimer's disease.

Worldwide evidence has recently shown that the allele epsilon4 of apolipoprotein E (ApoE) is a genetic risk factor for Alzheimer's disease (AD) underlining the possible role of apoE in the physiopathology of AD. To evaluate the usefulness of apoE concentration in pathogenesis of AD, we measured the cerebrospinal fluid (CSF) levels of apoE. CSF apoE level was significantly higher in 38 patients with late-onset AD than in 31 control patients and 47 patients suffering from other neurological and related diseases. Higher levels of CSF apoE were also present in a subset of patients with meningoencephalitis, motor neuron disease, and low back pain. The increase of CSF-apoE in AD is in agreement with results from studies that find an increase of mRNA apoE in the brains of AD patients. Compared to other works, these results underline the importance and the difficulties of the selection of the controls. The CSF apoE level seems to be a reflection of neuronal damage and/or an inflammatory reaction that may be common to AD and other neurological and related diseases.

Age of Onset↗
PubMed1997

Prospective evaluation of protein bound vitamin B12 (cobalamin) malabsorption in the elderly using trout flesh labelled in vivo with 57Co-cobalamin.

BACKGROUND: The frequency of dietary protein bound vitamin B12 malabsorption in elderly patients remains controversial. AIMS: To evaluate this malabsorption in elderly hospitalised patients using a modified Schilling test. PATIENTS: Fourteen elderly patients with low B12 blood levels were prospectively selected from 394 hospitalised patients. METHODS: The modified Schilling test was performed with trout labelled in vivo. RESULTS: The test was normal in five healthy elderly subjects, in 7/8 patients with pancreatic insufficiency, and in nine non-elderly patients with antral gastritis. The low decision limit was established at 3.3% (median 4.8%). From the 14 elderly patients with low B12 prospectively selected from 394 hospitalised patients, seven had a real deficiency with anaemia and an increased homocysteine and/or methylmalonate serum level. The modified Schilling test showed malabsorption in five of these patients, including two in which the standard Schilling test was normal, and three in which the standard Schilling test was partially corrected by an intrinsic factor. CONCLUSIONS: Protein bound vitamin B12 malabsorption was detected in at least 0.5% of elderly hospitalised patients, using the labelled trout flesh absorption test.

Adult↗
PubMed1997

Effects of malnutrition and atherosclerosis on the fatty acid composition of plasma phospholipids in the elderly.

The fatty acid profiles of plasma phospholipids have been compared in 53 elderly subjects suffering from malnutrition (group U, 17 subjects) or from atherosclerosis (group A, 15 subjects). A control group was also included in the study (group C, 21 subjects). Main differences were observed in phosphatidylcholine (PC). In group U, the proportion of monounsaturated fatty acids increased in PC, which was reflected by an increase in unsaturated fatty acids without significant modification of essential fatty acids. In group A, no major modification has been observed statistically, although the proportion of saturated fatty acids tended to increase.

Aged↗