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Biomedical subjects

F Percheron

Publications and source records attributed to F Percheron.

At least 19 recordsLinked to original sources

Patterns of alpha-L-fucosidase in acute myeloid leukemia cells. Comparison with promyelocytic HL-60 cell line.

Changes were observed in alpha-L-fucosidase forms in cells from acute myelocytic leukemias (AML). Total alpha-L-fucosidase activity was not significantly different for normal granulocytes and leukemic cells, but enzymic profiles obtained by chromatofocusing are quite different. In granulocyte profile, two main peaks are present (B and more acidic A) which were eluted at pH 5.2 with a shoulder at pH 4.6. In AMLs the B form is present but weakly expressed, whereas the more acidic forms are the major ones. This pattern may be related either to the malignancy character or to the stage at which the differentiation is stopped. Experiments on an HL-60 cell line (promyelocytic cells corresponding to the AML 3 type) showed that differentiation induced by dimethyl sulfoxide leads to the appearance of the B form present in normal mature cells. Thus the repartition of the enzyme forms seems to be related to the stage of differentiation of the myelocytic cells.

Acute Disease

Mammalian beta-D-mannosidase and beta-mannosidosis.

Lysosomal beta-D-mannosidase is the last exoglycosidase involved in the sequential degradation of the N-glycosylproteins glycans. Research on this enzyme was restricted before the discovery of its hereditary deficiency, first in goat (1981) and later in man (1986). We describe the biochemical aspects of these beta-mannosidosis and the properties of the beta-mannosidases of mammalian origin. Our own results concerning human enzyme (from kidney and urine, seminal plasma and blood cells) suggest that, apart from the case of the inherited disease, beta-mannosidase may become a useful tool in other pathologies.

Animals

Relationship between smoking status and serum lipids in a hyperlipidemic population and analysis of possible confounding factors.

The aim of our study was to estimate the potential relationship between smoking behavior and other coronary heart disease risk factors in 250 hyperlipidemic patients. We present data obtained through self-reporting of the number of cigarettes smoked per day, measurements of three tobacco markers, and data on dietary habits and lipid variables. We measured cotinine (by HPLC) and thiocyanate and used a recent colorimetric assay for the indirect evaluation of the nicotine metabolites in a single urine specimen. Mean values of nicotine metabolites, expressed as cotinine equivalents, were 6.7, 39.9, and 79.4 mumol/L, respectively, for nonsmokers, light smokers (7.7 cigarettes per day), and heavy smokers (25.8 cigarettes per day). We found that light smokers have higher concentrations of cotinine and nicotine metabolites in proportion to the number of cigarettes smoked per day than do heavy smokers. Thus, the simple colorimetric assay can accurately evaluate smoking status. Hyperlipidemia and smoking are linked by an intricate network of multiple relations. The concentration of high-density lipoprotein (HDL) cholesterol is lower in heavy smokers, and the concentrations of triglycerides and cholesterol are higher. The 0.11 mmol/L difference in HDL cholesterol between light and heavy smokers is close to the results of previous papers; however, when gender, dietary habits (including alcohol intake), and data on body mass index are included in a multiple regression analysis, there is no longer an association between HDL cholesterol concentrations and smoking status. Therefore, these different dietary habits may be confounding factors that partly explain the pattern of lipid variables.

Chromatography, High Pressure Liquid

[Alpha-L-fucosidase of normal and pathological blood cells].

The glycosidases, enzymes which participate in the degradation of glycoproteins and glycolipids inside the lysosomes are themselves glycoproteins and, for one enzyme, several forms may be isolated in tissues and in biological fluids, corresponding to variations in the composition or the structure of their glycanic moiety. We have previously studied the different forms of alpha-L-fucosidase in human serum, kidney and urine. Some modifications of the glycanic fraction of glycoproteins have been described in various forms of tumoral cells; therefore, we have attempted to verify if the alpha-L-fucosidase of blood cells might be a useful marker in the diagnosis of leukemias, using the enzymic pattern obtained by chromatographic or electrofocusing methods. Detergent extracts from normal lymphocytes, submitted to ion-exchange chromatography as well as to chromatofocusing, revealed the presence of two forms of alpha-L-fucosidase, A and B, with respective pIs of 5.7 and 6.2. After treatment by neuraminidase, these two forms remain distinct, showing that the degrees of sialylation is not the only difference. Moreover, after desialylation, the two forms have not the same affinity for concanavalin A, an argument for the heterogeneity of the glycanic structures. The determination of the total activity, and of enzymic patterns of alpha-L-fucosidase from leukemic cells led to the observation of three types of modifications, in comparison with normal lymphocytes: quantitative variations in the total activity; variations in the proportions of the two forms; variations due to the modification of pIs. We have studied the lymphocytes from four patients with a hairy-cell leukemia (HCL), four patients with chronic lymphoid leukemia (CLL) and the MO cell-line, proceeding from a HCL. In all cases, the total fucosidase activity is strongly decreased in comparison with normal lymphocytes activity. The chromatofocusing pattern for CLL cells reveals the presence of the A and B forms, without modification of their eluting pH. A characteristic pattern is obtained with hairy cells, presenting only the B form, eluted in more acidic conditions. The normal lymphocytes in peripheral blood are for 80 per cent of the T phenotype, and the CLL lymphocytes exhibit the phenotypic markers B, as well as the hairy cells, but the MO cell-line acquires in culture the T markers. As these last cells express both the A and B forms of enzyme, the absence of the A form of alpha-L-fucosidase seems to be a marker of the HCL.(ABSTRACT TRUNCATED AT 400 WORDS)

Biomarkers

Microheterogeneity of alpha 1-acid glycoprotein: variation during the menstrual cycle in healthy women, and profile in women receiving estrogen-progestogen treatment.

The concentration of alpha 1-acid glycoprotein (AGP) was measured in sera from 23 women, 14 pregnant women, 10 women receiving estrogen-progestogen treatment and 12 men. All sera were further subjected to crossed affino-immunoelectrophoresis with addition of conA in the first dimension and alpha-methylglucopyranoside in the second dimension. The distribution of AGP into three microheterogeneity forms, which were the result of this analysis, was estimated by measuring the area under the precipitation curve. The microheterogeneity patterns of AGP in the five groups were analysed from each other. An augmentation of the non reactive form is seen in women in the first part of the cycle and in women receiving estrogen-progestogen treatment compared with the three others groups. The pattern obtained in this latter group is similar to that observed in pregnant women (34 weeks) by several authors.

Estrogens

Human urinary and renal alpha-L-fucosidases. A comparative study.

1. Enzymatic forms of alpha-L-fucosidase from human renal tissue and urine were investigated. 2. In renal tissue two different isoenzymatic patterns were obtained by chromatofocusing of either directly soluble or detergent solubilized extracts. 3. On the other hand the urinary isoenzymatic pattern is similar to that obtained for the renal soluble extract.

Adult

Alpha-L-fucosidase isoenzyme pattern in hairy cell leukaemia.

alpha-L-Fucosidase isoenzymes pattern in hairy cell leukaemia (HCL) is characterized by the disappearance of the more acidic form when compared to normal lymphocytes. Our data seem to indicate that this profile could not be related to the T or B phenotype because in normal lymphocytes (mainly T), MO cells possessing T markers, as well as lymphocytes from chronic lymphoid leukaemia (CLL) known to exhibit normal-like B phenotypes two alpha-L-fucosidase forms are identified and especially the more acidic one.

Adult

Alpha-L-fucosidase activity in normal human lymphocytes.

After DEAE-Trisacryl chromatography two forms of alpha-L-fucosidase have been characterized in normal human lymphocytes. These enzymatic forms were different with respect to their optimum pH, kinetic properties and isoelectric behaviour. After neuraminidase treatment two forms are still observed with a neutral shift in pI values. These results suggest that at least two structurally different alpha-L-fucosidase units exist.

Adult

Sodium butyrate-induced structural and functional modifications in proteins of cultured rabbit articular chondrocytes.

The effects of sodium butyrate (NaB), a potent growth inhibitory agent, on actin distribution, alkaline phosphatase (AP) activity and protein content were studied in rabbit articular chondrocytes in monolayer culture. When growth of randomly proliferating cells was arrested with NaB, actin stress fibers appeared; at the same time, vimentin-containing intermediate filaments and tubulin-containing microtubules were dispersed. Concomitantly, membrane AP activity and protein content were increased. Such effects support the hypothesis that NaB affects the expression of many proteins by modification of gene expression, probably at the transcriptional level.

Alkaline Phosphatase

[Urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) and its isoenzyme B as a marker of the nephrotoxicity of gentamicin: re-test from an animal model].

A high level of NAG urinary excretion with marked isoenzyme B excretion are commonly considered as an indicator of aminoglycoside nephrotoxicity. The urinary excretion of NAG following gentamicin treatment was studied in rabbit. The rabbits received gentamicin at equivalent therapeutic (5 and 20 mg/kg/j) or toxic (50 mg/kg/j) doses during four days. Activities were measured daily and isoenzyme patterns were determined on the day of maximal urinary enzyme excretion. Isoenzyme patterns of kidney cortex, urinary control, and urinary gentamicin treated rabbits were compared. As compared with control rabbit, no changes in isoenzyme profiles appeared following the administration of gentamicin at 5-20 mg/kg/j. Thus, NAG enzymuria is constituted almost exclusively by isoenzyme A. Surprisingly, the high level of NAG excretion following the administration of gentamicin at 50 mg/kg/j is not accompanied by a marked excretion of isoenzyme B. The present results confirm controversy still exists regarding the clinical significance of urinary NAG excretion. These data indicate that increases in urinary NAG and isoenzyme B excretion following gentamicin treatment in Human are not always reliable indicators of renal tubular cell lysis.

Acetylglucosaminidase

[Quantification of proteinuria by measurement of the protein/creatinine ratio].

Accurate quantification of urinary protein excretion is difficult due to problems in 24-hour urine collection. We have evaluated the value of the protein/creatinine ratio in one single urine sample. There was an excellent correlation between this ratio and the protein content of a 24-hour urine collection [Pu (g/24 h) = 11.7 Pu (g/l) Cr (mmol/l); r = 0.96; P less than 0.001]. The best correlation was found with the sample collected after the first voided morning specimen. In our experience the ratio is more accurate for the quantification of urinary protein excretion than measurement of protein excretion in the same urine sample and also determination of protein excretion in 24-hour urine collected under the usual ambulatory conditions. We suggest that the protein/creatinine ratio should be used in ambulatory and hospitalized patients, especially for multicentric clinical trials in nephrology.

Ambulatory Care

beta-D-mannosidase in human polymorphonuclear leukocytes and lymphocytes: a comparative study.

All lymphocytes and polymorphonuclear leukocytes (PMNL) beta-D-mannosidase activities are adsorbed on DEAE-Trisacryl column at pH 7.0. Only one form is eluted with a 0.15 M linear gradient. The two enzymes isolated from either type of cells exhibit similar properties. The chromatographic profiles of beta-D-mannosidase from leukemic lymphocytes (chronic lymphoïd leukemia and hairy cells leukemia) differ from the normal ones by the presence of a more acidic minor form.

Humans

Partial characterization of intracellular and secreted glycosidases from rabbit articular chondrocytes in culture.

N-Acetyl-beta-hexosaminidase, beta-galactosidase and beta-glucuronidase activities were shown to be present in cultured rabbit articular chondrocytes. Secretion of enzyme activity seems to preferentially result in the accumulation of N-acetyl-beta-hexosaminidase. Three days after seeding, the amount of N-acetyl-beta-hexosaminidase activity found in the medium accounts for about 140% of the total N-acetyl-beta-hexosaminidase activity after complete disruption of the cell pellet. Optimal conditions of incubation time, cell numbers, substrate concentration, and pH for glycosidase activities were determined in 0.1% Triton X-100. Intracellular and secreted glycosidases have shown similar elution profiles by chromatofocusing. N-acetyl-beta-hexosaminidase exhibits two major forms which may play a role in the catabolism of glycosaminoglycans.

Acid Phosphatase

beta-Mannosidase in human serum and urine. A comparative study.

All serum and urine beta-mannosidase activities are adsorbed on a DEAE-Trisacryl column at pH 6. Only one form is eluted with a NaCl linear gradient. The two enzymes, isolated from either serum or urine exhibit similar properties. Slight differences are only observed in thermostability and molecular weight.

Adult

Decreased serum beta-D-mannosidase activity in diabetic patients, in comparison with other glycosidases.

A study of four lysosomal glycosidases' activities was carried out on sera from 64 diabetic patients, which revealed important variations in comparison with the activities observed in sera of control subjects. Depending on the type of diabetes mellitus (I, insulin-dependent, or II, non-insulin-dependent), three activities were more or less increased: alpha-L-fucosidase, alpha-D-mannosidase, and N-acetyl-beta-D-glucosaminidase, in agreement with previously published results. Against that, the beta-D-mannosidase activity shows a highly significant decrease in sera from either diabetic type. Up to now, no suitable explanation has been found for these variations occurring in an unusual direction.

Acetylglucosaminidase