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Biomedical subjects

C Jeandel

Publications and source records attributed to C Jeandel.

At least 19 recordsLinked to original sources

Age-related variations of enzymatic defenses against free radicals and peroxides.

Superoxide dismutase, glutathione peroxidase and catalase are the three main enzymatic systems of defense of the organism against free radicals and peroxides. A survey of the literature shows that no general tendency of evolution of these systems in aging emerges, even if some recent studies in humans demonstrate the existence of a concomitant decrease in most of the antioxidant enzymes in blood of the elderly. The study of the antioxidant systems and their interrelations in the elderly represents a large field of future investigations.

Adult

Effect of age on the disposition of sodium fluoride.

Sodium fluoride (NaF) is used in the treatment of axial osteoporosis and so is mostly given to old patients. Since its pharmacokinetics has not been studied in the elderly, the pharmacokinetics of an enteric-coated tablet containing 50 mg NaF has been investigated in 15 aged inpatients (aged 65 to 75 y) and 12 young healthy volunteers (aged 21 to 26 y). The serum AUC of fluoride was 1.7-time higher in older than in younger subjects. There was a strong inverse correlation between the AUC and either body surface area (BSA) or glomerular filtration rate (GFR), both of which were very much lower in the elderly. This concluded that if efficacy or safety are related to the bioavailability of fluoride, it may be valuable to adjust the dosage of fluoride accordingly to the GFR and BSA.

Adult

Assessment of the clinical value of urinary trypsin inhibitory activity in elderly people.

To assess the clinical value of urinary trypsin inhibitory activity (UTIA) in elderly people, a prospective study was carried out over 4 months in our internal medicine department. Two hundred and forty-three patients of more than 60 years of age were included. A positive correlation was observed between UTIA and serum creatinine (p < 10(-3)). In the population with serum creatinine of less than 133 mumol/l (200 patients), UTIA was independent of age, sex and serum creatinine. UTIA was compared with seven serum inflammatory proteins titrated on patient admission. The principal interest of UTIA determination appeared in bacterial infections. UTIA was significantly increased in this group (p < 10(-4)). However, a positive correlation was proved only with C-reactive protein (CRP) (p = 9 x 10(-4)). Nevertheless, CRP appeared to be the best marker of bacterial infectious diseases after receiver operating characteristic curves analysis.

Acute-Phase Proteins

[LH-RH agonist in subjects treated with growth hormone for somatotropin deficiency. Development of growth velocity and prediction of body height].

The final adult height in patients with growth deficiency treated with growth hormone has been shown to depend upon pubertal development. This is mainly related to the shortening of puberty duration and accelerated bone maturation. A long acting analogue of gonadoliberin, Trp-6-GnRH, has been given to 17 patients with isolated growth hormone deficiency in order to delay pubertal progression. In seven of these patients, GH treatment and the analogue of Gn-RH were initiated simultaneously. The other 10 patients had been treated for more than one year with hGH at the onset of the analogue. Mean duration of treatment was 17 months. Annual growth rate was low in all cases. Statural progression was parallel to the delayed bone maturation without change in the ratio of statural maturation to bone maturation. No significant change in height prediction was observed after the combined treatment. Combination of the long-acting analogue of gonadoliberin, Trp-6-Gn-RH, with growth hormone in GH-deficient patients does not seem to be an appropriate way to improve final height after the onset of spontaneous puberty.

Adolescent

Biological variability of superoxide dismutase, glutathione peroxidase, and catalase in blood.

We studied the biological variability of blood superoxide dismutase (SOD; EC 1.15.1.1), glutathione peroxidase (GPX; EC 1.11.1.9), and catalase (CAT; EC 1.11.1.6) in a sample of 1836 apparently health subjects, ages 4-97 years. SOD and GPX activities were assayed in plasma (P) and erythrocytes (E) by automated methods, and CAT was measured in erythrocytes by a manual technique. No statistically significant variation of these antioxidant enzyme activities according to gender was demonstrated, except for E-GPX, which was slightly but significantly higher in women than in men (P less than 0.001). Activities appear rather stable in adults less than 65 years old, but decrease for most enzymes in the elderly. There is no evidence that weight, blood pressure, or menopause influences the antioxidant enzymes' activities. In girls ages 10-14 years, E-SOD activity is reduced by 16% (P less than 0.05) after menarche. Variations related to smoking and alcohol consumption are slight and concern only P-SOD and P-GPX, respectively. Conversely, intake of some drugs (e.g., anti-inflammatory agents, antidepressants, and thyroid hormones) modifies activity of some of the three enzymes. E-SOD positively correlates with P-SOD (r = 0.216, P less than 0.001) and E-CAT (r = 0.123, P less than 0.001), and E-GPX with P-GPX (r = 0.218, P less than 0.001). Finally, we propose reference intervals for activities of the three antioxidant enzymes in blood in individuals less than 65 years old.

Adolescent

Blood activity of Cu/Zn superoxide dismutase, glutathione peroxidase and catalase in Alzheimer's disease: a case-control study.

Cu/Zn superoxide dismutase (Cu/Zn SOD), glutathione peroxidase (GPx) and catalase, which are the three main enzymes involved in cellular protection against damage due to oxygen-derived free radicals have been assayed in plasma and erythrocytes obtained from subjects with dementia of the Alzheimer type (DAT) and from controls. Blood samples were obtained from 25 patients with DAT and from age-matched subjects without diagnoses of neurological disease (non-DAT), as well as from younger individuals (reference group). Using appropriate statistical procedures, the three enzyme activities measured in blood of the elderly were decreased if compared to the younger reference group. Moreover, a significant increase in erythrocyte Cu/Zn SOD and catalase activities of DAT patients was observed compared to the non-DAT group. These results are discussed taking the free radical theory of aging into consideration.

Aged

[Cerebrospinal fluid amino acids in Alzheimer's disease].

Twenty-two amino acids are measured in cerebrospinal fluid of fourty patients with senile dementia of the Alzheimer type (SDAT) and of ten age matched healthy control subjects. There is no significant difference between these two groups.

Aged

Lipid peroxidation and free radical scavengers in Alzheimer's disease.

Lipid peroxidation products and defenses against free radical damage were determined in serum of 55 patients with senile dementia of the Alzheimer type (SDAT) and compared with values in 24 age-matched healthy control subjects. The following parameters were evaluated: lipid-conjugated dienes and trienes, malondialdehyde, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity in erythrocytes, vitamins E, C and A, zinc, selenium and copper, ceruloplasmin, transferrin and albumin. The results showed a statistically significant decrease in the levels of GSH-Px, vitamins E, C and A, zinc, transferrin and albumin in the SDAT group. On the other hand, most of the deficiencies concern the malnourished subgroup of the SDAT population (SOD, GSH-Px, vitamins E and C, selenium, zinc, transferrin and albumin). Such an alteration of free radical scavengers in the malnourished subgroup of the SDAT population could combine the radical and nutritional hypothesis advanced by some authors.

Aged

[Adynamia episodica hereditaria: Gamstorp's disease or Eulenburg's paramyotonia?].

Over seven generations owing 71 identified and studied persons, 18 (12 males and 6 females) suffered paroxystically adynamic paralysis or myotonic accesses. A such association is rare and according to the proeminent symptoms is denominated as hyperkaliemic periodic paralysis or as congenital paramyotonia. In the both forms of the diseases: cold injury, fasting, long time resting, or efforts are able to provoke crisis and so does an oral potassium loading. Studies on Ka+Na membrane permeability suggest the responsibility of Na+ K+ pump and may explain the physiopathology of the alternative manifestations at the muscle cellular level but may be are rather a marker than a cause of permeability disturbances. In the present family, some clinical, biological and electrophysiological arguments suggest the unicity of the disease. A better way to confirm that would be the localisation of a unique gene in the patient. DNA samples of several members are in study for molecular biology in the hope to precise a identical location. Some informations from molecular biologists suggest a probable location near the myotonic dystrophy (M.D.) in the 19 q12 but not identical with it.

Genes, Dominant