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Biomedical subjects

E Delacoux

Publications and source records attributed to E Delacoux.

At least 19 recordsLinked to original sources
PubMed1996

Determination of tryptophan and its kynurenine pathway metabolites in human serum by high-performance liquid chromatography with simultaneous ultraviolet and fluorimetric detection.

An isocratic reversed-phase high-performance liquid chromatographic method for the simultaneous determination of tryptophan and four metabolites of the kynurenine pathway (kynurenine, 3-hydroxykynurenine, kynurenic acid and 3-hydroxyanthranilic acid) in human serum is described. This new method, which uses both isocratic elution and two on-line connected programmable ultraviolet and spectrofluorimetric detectors, allows the determination of these metabolites, in the physiological ranges, with satisfying specificity and sensitivity within 30 min.

Chromatography, High Pressure Liquid↗
PubMed1995

[Beta-2 microglobulin in cerebrospinal fluid in neurology].

OBJECTIVES: beta 2-microglobulin (beta 2-m) is a small molecular weight protein (11 800 Daltons) which can transudate into the cerebrospinal fluid (CSF) in the same manner than albumin. Intrathecal synthesis is a sign of local immuno-stimulation and is correlated with immunoglobulin G. The aim of this study was to ascertain the relationship between beta 2-microglobulin levels in the CSF and neurological diseases. METHODS: beta 2-microglobulin was assayed in the CSF and blood using an immunoenzyme method in 64 patients with multiple sclerosis (n = 14), human immunodeficiency virus (HIV) infection (n = 5), meningitis (n = 12) or a peripheral neurological disease (n = 10) and in 7 control subjects. RESULTS: There was no overall correlation between beta 2-m in the CSF and blood levels (r = 0.35). In controls, beta 2-m CSF and blood levels were respectively 0.94 +/- 0.22 and 1.46 +/- 0.83 mg/l. beta 2-m was significantly higher in the CSF of patients with meningitis and in the HIV positive patients (4 +/- 3.5 and 3.69 +/- 2.06 mg/l respectively) (p < 0.05). Type of meningitis (bacterial or non-bacterial) had no effect on the CSF level. For the HIV patients, the CSF/blood ratio for beta 2-m was similar to that in controls due to a rise in both blood and CSF. Finally, in patients with multiple sclerosis, there was no significant change in CSF level of beta 2-m. CONCLUSION: beta 2-microglobulin in cerebrospinal fluid was not found to be correlated with the neurological diseases studied and cannot be used as a diagnostic test.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Simultaneous determination of retinyl esters and retinol in human livers by reversed-phase high-performance liquid chromatography.

A high-performance liquid chromatographic method for the simultaneous determination of retinol and retinyl esters in human liver samples is presented. The free retinol and the prevalent retinyl esters (retinyl palmitate, oleate and stearate) are resolved within less than 30 min, using an octasilyl (C8)-substituted column and an isocratic elution with methanol-water as mobile phase. This method allows to determine in duplicate all retinyl ester concentrations in small liver samples (3-10 mg of fresh tissue). The results obtained from thirteen patients without liver disease are described.

Adult↗
PubMed1995

Comparison of erythrocyte transketolase activity with thiamine and thiamine phosphate ester levels in chronic alcoholic patients.

The effect of chronic alcoholism on biochemical evaluation of thiamine status was studied by the concomitant determination of erythrocyte transketolase (ETK) activity, its relative increase by in vitro addition of thiamine diphosphate (TDP effect) and the direct measurement of thiamine and its phosphate esters by high performance liquid chromatography. Thirty-eight percent of alcoholic subjects showed a thiamine deficiency with decreased thiamine diphosphate concentrations compared with healthy subjects (90.8 +/- 25.7 nmol/l vs. 176 +/- 28.0 nmol/l, respectively, mean +/- S.D., P < 0.001). Thiamine diphosphate concentrations were highly correlated with total thiamine concentrations and TDP effect (respectively r = 0.99 and 0.79, n = 85, P < 0.001). No abnormality in thiamine phosphorylation related to chronic alcoholism was noted. Finally, 47% of these deficient alcoholic patients had normal ETK activity. We concluded that, if indirect evaluation of thiamine status is to be chosen, the determination of ETK activity should be associated with TDP effect since the latter has been shown to be highly linked to total thiamine and thiamine diphosphate in erythrocytes. Furthermore, the direct measurement of thiamine and its phosphate esters was a more sensitive and specific index of thiamine nutrition.

Adult↗
PubMed1994

Determination of thiamine and its phosphate esters in human erythrocytes by high-performance liquid chromatography with isocratic elution.

A high-performance liquid chromatographic method for the simultaneous determination of thiamine and its phosphate esters in human erythrocytes, using postcolumn derivatization, is presented. The sample preparation and the choice of the analytical column avoid the use of an elution gradient. The four thiamine compounds (thiamine and thiamine monophosphate, diphosphate and triphosphate) are eluted within less than 15 min with a detection limit of ca. 20 fmol. The reproducibility and accuracy of the assay are satisfactory. Normal physiological red blood cell concentrations of the four thiamine compounds are included.

Adult↗
PubMed1986

Reference intervals for vitamins B1, B2, E, D, retinol, beta-carotene, and folate in blood: usefulness of dietary selection criteria.

Reference intervals for normal concentrations in blood of vitamins B1, B2, E, D, retinol, beta-carotene, and folic acid were determined from a selected sample of people attending a Health Examination Center or being examined in occupational health services in France. This reference sample consisted of 362 men and women, ages 18 to 44 years, selected according to the main variation factors known for the vitamins studied: consumption of tobacco and alcohol, ponderal index (relating height and weight), use of drugs and oral contraceptives, and past history of surgical or medical treatment. Reference intervals were determined for each sex. Vitamin B1 (erythrocyte transketolase activity), plasma retinol, and folic acid values in whole blood are significantly higher in men than in women (p less than 0.001), but vitamin B2 (activation of erythrocyte glutathione reductase) and plasma beta-carotene values are significantly higher in women (p less than 0.001 and less than 0.01 respectively). Dietary intake of vitamins produced no significant displacement of the reference values. For each vitamin we discuss the other major sources of variation factors and the usual values reported in the literature.

Adolescent↗
PubMed1985

"ESVITAF". Survey on the vitamin status of the French: relationships between nutrient intake and biochemical indicators.

The relationships between dietary data and biochemical nutritional status for vitamins B1, B2, A, E, beta-carotene, folic acid and iron have been studied using data from a survey conducted on 710 adults. Significant correlations were found between riboflavin intake and biochemical values for males only (r = -0.105, p less than or equal to 0.05), between beta-carotene intake and plasma beta-carotene (r = 0.232, for males and r = 0.292 for females, p less than or equal to 0.001), and between iron intake and plasma iron for males only (r = 0.115, p less than or equal to 0.05). Concerning nutrient densities, correlations were significant between dietary riboflavin and biochemical measure (r = 0.163, p less than or equal to 0.01 for males, r = -0.135, p less than or equal to 0.05 for females), between vitamin A intake (expressed in retinol equivalent) and beta-carotene (r = 0.212, p less than or equal to 0.001 for males, r = 0.157, p less than or equal to 0.01 for females) and for males only, between dietary iron and hemoglobin (r = 0.144, p less than or equal to 0.01). The dietary data for each nutrient were examined for their sensitivity, specificity and predictive values in identifying subjects with substandard or overstandard biochemical values. For all nutrients the positive predictive value percentage was always below 25%, the negative predictive value percentage always under 75%.

Adolescent↗
PubMed1984

Skin disorders and vitamin A metabolism disturbances in chronic dialysis patients: the role of zinc, retinol-binding protein, retinol and retinoic acid.

The authors have studied--in the plasma--the changes of zinc, retinol binding protein (RBP), retinol and retinoic acid with reference to the dermatological status of fifty chronically haemodialysed renal insufficiency patients divided into four subgroups (normal skin, dry skin, dry skin with keratosis, and only keratosis). The results of these groups were compared to those of thirty healthy subjects. The values of these variables do not show any significant difference in function of the dermatological subgroups; but, despite the considerable rise in the retinol binding protein and retinol levels in comparison with the controls (haemodialysis patients: RBP = 11.77 +/- 2.83 mumol X l(-1), retinol = 7 +/- 2.57 mumol X l(-1); controls; RBP = 2.76 +/- 0.62 mumol X l(-1), retinol = 2.16 +/- 0.53 mumol X l(-1] the electromicroscopic examination of skin biopsy samples from some of the patients did not reveal any sign of hypervitaminosis A in the lesions.

Humans↗
PubMed1982

[Biological criteria of denutrition. Search of significant parameters for diagnosis and management in surgical departments].

Assessment of the nutritional status of surgical patients with a mean weight loss of 11.5 kg included determination of the following biochemical parameters: prealbumin, retinol-binding protein (RBP), serum vitamin A and serum zinc. Patients' immunological status was investigated by delayed hypersensitivity skin tests. Prealbumin and RBP are decreased in patients. RBP levels are significantly lower than in controls: RBP therefore seems to be a better criterion of denutrition than prealbumin. Serum RBP and vitamin A concentrations are not always correlated in patients; for instance, in malabsorptions, the sharp fall in serum vitamin A is isolated. The decrease in mean serum zinc concentrations is minor. Three patients have positive skin tests with severe biochemical disturbances; only serum zinc concentrations are normal and correlated with the results of skin tests. Interpretation of investigations in surgical patients is dependent on the cause of weight loss. However, biochemical and immunological assessment of the nutritional status can demonstrate specific deficits and improve preoperative nutrition.

Aged↗
PubMed1981

[The PABA test in chronic pancreatitis: value of plasma para-amino benzoic acid determinations (author's transl)].

Plasma concentrations and urinary excretion of para-aminobenzoic acid (PABA) were measured over a 6-hour period after administration of N-benzoil L-tyrosyl aminobenzoic acid (NBT-PABA) to 15 patients with chronic pancreatitis and 15 controls. The sum of plasma PABA concentrations at 1 hour and 2 hours was calculated for each subject. The resulting value proved to have a specificity of 100% and a sensitivity of 80%, as opposed to 86% and 67% respectively for urinary concentrations.

4-Aminobenzoic Acid↗
PubMed1978

[Prevention of ocular toxicity of ethambutol: study of zincaemia and chromatic analysis (author's transl)].

In order to define the means of prevention of the ocular toxicity of ethambutol (EMB), 72 patients under treatment with EMB-INH-Rifampicin combination were subjected to systematic analysis of plasma, blood and urinary zinc levels together with a full ophthalmic examination. Comparison of the results from 12 patients sustaining ocular damage at the time of treatment with the results of 60 others: 1) demonstrates the existence of a correlation between plasma zinc levels before treatment and the probability of ocular damage from EMB (high risk for zinc is less than 0.70 mg/l - almost no risk for zinc greater than 1 mg/l); 2) confirms that dyschromatopsia is one of the first signs of ocular damage through EMB and thus constitutes an alarm signal; 3) suggests that the ocular toxicity of EMB might appear in the retina before the optic nerve.

Adult↗