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J Arnaud

Publications and source records attributed to J Arnaud.

At least 91 records · Page 5Linked to original sources
PubMed1993

Affinity differences for vitamin D metabolites associated with the genetic isoforms of the human serum carrier protein (DBP).

Human vitamin D binding protein (DBP) displays considerable polymorphism with 120 described alleles. Among these, three alleles are frequently observed, Gc 1F (pI 4.94-4.84), Gc 1S (pI 4.95-4.85) and Gc 2 (pI 5.1). Differences between these genetic forms of the protein in affinity for vitamin D metabolites have been detected by electrophoretic methods. The constant affinity (Ka) values determined in this study confirm these differences. The affinities of six rare variants were also examine. Those of the DBP genetic forms to the vitamin D derivatives 25-OH-D3 and 1,25-(OH)2-D3 seem to be related to the isoelectric point of the proteins: a high affinity corresponding to a low isoelectric point. The Gc 1A9 and 1A11 mutants were associated with higher affinity for the vitamin D derivatives and the Gc 1C1 and 1C21 mutants were deficient.

Calcifediol↗
PubMed1993

Lipid peroxides and antioxidant defenses in accelerated transplantation-associated coronary arteriosclerosis.

Accelerated coronary artery disease develops in most if not all heart transplant recipients within the first year after transplantation. Increased lipid peroxidation seems to be involved in atherogenesis. In these patients we have investigated whether there is an association between lipid peroxidation, reduced antioxidant defenses, and some conventional coronary risk factors. Lipid peroxides, lipids, uric acid, albumin, antioxidant enzymes and their cofactors (the trace elements selenium, iron, copper, and zinc) have been determined in heart transplant recipients compared with nonrecipients with coronary artery disease. Lipid peroxides (p = 0.002) and uric acid (p = 0.01) were higher and zinc (p = 0.001) was lower in heart transplant recipients. Thirteen of 30 transplant recipients compared with one of 30 nonrecipients (p < 0.001) had very low (less than 10 mumol/L) zinc levels. Antioxidant enzymes and other trace elements were not significantly different. In univariate regression analysis, zinc correlated positively with albumin (p = 0.02) and negatively with lipid peroxides (p < 0.05). Uricemia had a strongly positive correlation with hydroperoxides (r = 0.45; p = 0.0001). In stepwise multivariate regression analysis, lipids, uricemia, creatinine, and zinc were significant (p < or = 0.004) predictors of the lipid peroxide level. Cyclosporine and corticosteroid dosages were significant (p = 0.01) determinants of zinc concentration in the transplant recipients. Although a causal relationship between increased lipid peroxidation and accelerated arteriosclerosis is not definitely demonstrated, the results of this analysis suggest new insights into conventional coronary disease risk factors and possible therapeutic interventions; further controlled trials are needed.

Adult↗
PubMed1993

Comparison of serum copper determination by colorimetric and atomic absorption spectrometric methods in seven different laboratories. The S.F.B.C. (Société Française de Biologie Clinique) Trace Element Group.

An interlaboratory collaborative trial was conducted on the determination of serum copper using two different methods, based on colorimetry (test combination Copper, Boehringer Mannheim, Mannheim, Germany) and flame atomic absorption spectrometry (FAAS). The general performance of the colorimetric method was below that of FAAS, except for sensitivity and linear range, as assessed by detection limit (0.44 versus 1.32 mumol/L) and upper limit of linearity (150 versus 50 mumol/L). The range of the between-run CVs and the recovery of standard additions were, respectively, 2.3-11.9% and 92-127% for the colorimetric method and 1.1-6.0% and 93-101% for the FAAS method. Interferences were minimal with both methods. The two techniques correlated satisfactorily (the correlation coefficients ranged from 0.945-0.970 among laboratories) but the colorimetric assay exhibited slightly higher results than the FAAS method. Each method was transferable among laboratories.

Analysis of Variance↗
PubMed1993

Serum beta-carotene and antioxidant micronutrients in children with cancer. The 'Cancer in Children and Antioxidant Micronutrients' French Study Group.

Serum antioxidant vitamins A (retinol) and E (alpha-tocopherol), beta-carotene, zinc and selenium for 418 children with newly diagnosed malignancy were compared with those of 632 cancer-free controls. Incident cancer cases and controls were 1-16 years old and recruited in 1986-1989. Age- and sex-adjusted serum concentrations of retinol, beta-carotene and alpha-tocopherol were significantly inversely associated with cancer. In similar models, the odds ratio (OR) comparing the highest with the lowest quintile was 2.06 (95% confidence interval [CI] 1.40-3.02) for retinol, 3.87 (95% CI: 2.54-5.90) for beta-carotene, 2.15 (95% CI: 1.48-3.10) for alpha-tocopherol, 1.29 (95% CI: 0.75-2.23) for selenium, and 1.94 (95% CI: 1.17-2.23) for zinc. The cancer sites that were associated with serum beta-carotene were, in general, leukaemia, lymphoma, central nervous system, bone and renal tumours. Moreover, leukaemia was associated with low mean serum levels of retinol, selenium and zinc. Subjects with lymphoma, bone and renal tumours also had lower mean retinol and alpha-tocopherol levels than controls. Brain tumour patients had low vitamin E levels. Low serum values of antioxidant vitamins were associated with childhood neoplasm occurrence. Some site-specific effect was reported. Low peripheral nutrient levels are not considered as cancer promoters but rather as an impairment of the body's defence mechanism occurring during the cancer-related metabolic and nutritional disturbances and inflammation processes.

Adjuvants, Immunologic↗
PubMed1993

Effect of iron supplementation during pregnancy on trace element (Cu, Se, Zn) concentrations in serum and breast milk from Nigerian women.

Trace element concentrations in serum and breast milk were studied longitudinally in 197 Nigerian women from 6 months of gestation to 6 months postpartum; 99 of them received a daily iron supplement of 100 mg from 6 months of gestation to delivery. During the last 3 months of pregnancy, serum selenium declined, whereas serum zinc remained unchanged and serum copper increased. After delivery, copper concentration in maternal serum decreased, whereas serum zinc increased from delivery to 3 months postpartum and then reached a plateau. Serum selenium increased from delivery to 6 months postpartum. In breast milk, selenium and zinc decreased from 5 days to 6 months postpartum. Copper in breast milk also declined during the course of lactation but reached a plateau by 3 months postpartum. Iron concentration in breast milk remained unchanged during the study. Iron supplementation had no significant effect upon the concentrations of copper, selenium and zinc in mother serum and breast milk. In umbilical serum, iron status, copper and zinc levels were similar in the two groups, whereas, unexpectedly, selenium concentration was significantly decreased (p < 0.03) in the iron-supplemented group. Taken together, our results suggest that the beneficial effect of iron supplementation on iron deficiency was not associated with an adverse effect on copper and zinc status. On the other hand, our results suggest that Nigerian women had a marginal zinc status but an adequate selenium status.

Adolescent↗
PubMed1993

Sampling conditions for biological fluids for trace elements monitoring in hospital patients: a critical approach.

Lack of coherence in the results of trace element (TE) analyses produced by various laboratories has been such as to necessitate much needed technical improvements and more detailed control over sample preparations. For too long, except for a few praiseworthy researchers, the importance of sampling conditions has been underestimated as a source of erroneous TE results. Many of the precautionary procedures for previously studied TE collection materials have proven to be so cumbersome that they cannot be applied in a hospital setting. This report deals with sampling material and conditions from a workday standpoint; a rigorous description of the contaminating roles of ambient air and routine handling of specimens places emphasis on the practical. While some metals, including cobalt, copper, iron, and selenium, present no significant risk of contamination, others, such as aluminum, cadmium, chromium, manganese, and nickel, pose quite a significant risk. They warrant attention with respect not only to the sampling itself but also the selection of the material to be used. Drawing on our hospital experience, we propose a critical approach toward the collection of samples of biological fluids (blood, urine, dialysis fluids). Needles, catheters, tubes (open and evacuated systems), and anticoagulants on the market are likewise assessed in terms of their contaminative roles. For each one elementary rules as well as realistic choices of materials and methods for a hospital environment are proposed.

Body Fluids↗
PubMed1993

[Trace elements balance in treated phenylketonuria children. Consequences of selenium deficiency on lipid peroxidation].

We studied Ca and Mg and trace elements (Zn, Cu, Fe, Mn, Se) in 15 P.K.U. children treated with strict Phe-reduced diet and in a control group. P.K.U. children are significantly lower (p < 0.01) plasma and erythrocyte Se as well as significantly lower (p < 0.01) activities of Glutathione-Peroxidase (GSH-Px), a seleno-dependent enzyme in erythrocytes and in plasma. Concomitantly with defective GSH-Px activities we observe significantly (p < 0.01) increased levels of lipid peroxidation products: malonaldialdehyde (MDA) and organic hydroperoxides (O.H.P.). So, Se supplementation appears to be necessary in low phenylalanine products used in P.K.U. treatment.

Child↗
PubMed1993

Selenium determination in human milk in Niger: influence of maternal status.

Selenium (Se) was determined in human milk from women residing in Niamey (Niger) at different periods of lactation. To this purpose, a rapid electrothermal atomic absorption spectrometric (EAAS) method using Zeeman background correction and palladium matrix modifier was developed. Linear range (10 nmol/L-6.25 mumol/L, 0.8-494 micrograms/L), within-run (7.6%), between-run (10.4%), precision and recovery of standard addition (101 +/- 7%) were sufficient to allow routine determination of Se in breast milk. Values of breast milk Se decreased from 5 days to 6 months postpartum. No significant correlation was found between the milk Se and any of the following parameters: mother serum Se, parity, age of the mother, age of the previous child. In mother serum, Se concentration increased from delivery to 3 months postpartum and remained stable afterwards. The Se concentrations found in breast milk and in mother serum suggest that Se status is adequate in Niger.

Adolescent↗
PubMed1993

Copper.

Static and functional indices used for the assessment of copper status in humans are discussed in this review. Variations, advantages and disadvantages of the different indices are reported. Good indices of copper status remain to be found.

Ceruloplasmin↗
PubMed1993

Biosynthesis of Tcr-alpha, beta and Tcr-gamma, delta/CD3 complexes.

Jurkat J76 clone, LYON L12.37 clone and L12.37 cells transfected with J76-alpha cDNA or J76 Tcr-alpha mutated cDNA (J79) were analysed for membrane expression of Tcr/CD3 complex using WT31 mAb (Tcr-alpha, beta) or Tcr-delta 1 mAb (Tcr-gamma, delta): LYON cells express V beta 9 bearing Tcr-beta chains. J76 Tcr-alpha cDNA transfected LYON cells have intracellular Tcr-gamma, delta chains and J79 Tcr-alpha cDNA transfected LYON cells have intracellular Tcr-alpha (M), beta chains.

Amino Acid Sequence↗
PubMed1993

[Nutritional biological markers of deficiencies of zinc, copper and selenium].

Direct and indirect indices used for the assessment of copper, zinc or selenium status in humans are reviewed. Variations, advantages and disadvantages are discussed. Despite the numerous indices, none of them provide a satisfactory assessment of the nutritional status for these trace elements. The best indices are probably serum zinc and alkaline phosphatase for the assessment of zinc status, serum selenium for the assessment of selenium status and possibly erythrocyte Cu-Zn superoxide dismutase for the assessment of copper status.

Adolescent↗
PubMed1993

Assessment of the methods for the detection of Epstein-Barr virus nucleic acids and related gene products in Hodgkin's disease.

BACKGROUND: Epstein-Barr virus (EBV) is present in the pathogenic cells of a significant number of cases of Hodgkin's disease, particularly of the mixed cellularity subtype. EBV remains latent and the incidence of detection rate of the genomes and gene products varies greatly with the methods employed. EXPERIMENTAL DESIGN: From a pool of 137 cases of Hodgkin's disease previously studied by cold in situ hybridization (ISH) for the presence or absence of EBV DNA and the immunohistochemical reactivity with anti-latent membrane protein 1 antibody, we selected 24 cases (12 EBV DNA-positive, 12 EBV DNA-negative) for Southern blotting, as well as for study with nonisotopic EBER and BHLF1 oligonucleotide probes and amplification of DNA by polymerase chain reaction. EBV positive cases were further tested with anti-ZEBRA (BZLF1) antibody. RESULTS: The EBV DNA detection rate was found to be lower with Southern blotting compared to ISH and IHC methods because 8 of the 12 EBV positive cases were positive with BamHI W probe and only 7 (of the 8) with XhoI 1.9 kb probe. These 7 cases contained monoclonal episomal circular EBV genomes. All EBV DNA-positive cases showed EBER gene transcription by ISH. EBER probes also reacted with small lymphocytes in all EBV DNA+ and 9 EBV DNA- cases. These EBER-positive small lymphocytes were detected neither by BamHI W DNA probe nor by immunohistochemical methods with anti-latent membrane protein 1 and anti-EBNA2 antibodies. Polymerase chain reaction produced a positive result in all EBV DNA+ cases and 2 (of the 9) EBV DNA- cases containing EBER+ small lymphocytes. This discrepancy was attributed to amplification of EBV in reactive lymphocytes. Anti-ZEBRA antibody was positive in 2 cases (one BHLF1+) suggesting infrequent viral replication and probable abortive lytic cycle. CONCLUSIONS: ISH and immunohistochemical methods are more sensitive than Southern blot for detecting EBV in Hodgkin and Reed-Sternberg cells of Hodgkin's disease. Polymerase chain reaction appears to be very sensitive but is less sensitive and specific (amplification of EBV DNA of non-neoplastic lymphocytes) than ISH with non-isotopic EBER oligoprobes, which often detects and localizes EBV in pathogenic cells even when they are in small numbers and also in a few small lymphocytes. In addition, this method offers the advantage of being applied to routinely processed tissue sections.

Antigens, Viral↗
PubMed1993

Lipid peroxidation and trace element status in diabetic ketotic patients: influence of insulin therapy.

Lipid peroxidation is known to accelerate aging and microvascular lesions in diabetic patients. We studied the acute influence of improved glycemic control on the concentrations of plasma lipid peroxidation intermediates [malondialdehydes (MDA), organic hydroperoxides (OHP)] in ketotic insulin-dependent diabetic patients, as well as the interplay of enzymes such as glutathione peroxidase (GPX) and CuZn superoxide dismutase (CuZn-SOD), and trace elements (Zn, Se, Cu) postulated to be involved in free radical protection. These plasma components were measured on the first day of hospitalization (T0) and when the patient had attained a stable glycemic state after continuous insulin treatment (T1). Plasma MDA and OHP concentrations were high at the beginning of the study but approached reference values after glycemic equilibration. Plasma zinc concentrations were significantly (P < 0.05) decreased during the ketotic state, but also approached reference values with glycemic equilibration. Plasma selenium concentrations and GPX activity were relatively unchanged between T0 and T1. Erythrocyte GPX activity measured at T1 in six patients was below the reference values, whereas CuZn-SOD activity was not affected. Our results show that enhanced lipid peroxidation is associated with decreased zinc plasma concentrations in ketotic patients and underline the beneficial effects of continuous insulin infusion. The mechanisms involved are still unclear but may indicate the importance of extracellular zinc transfer secondary to glycemic disorders.

Adult↗
PubMed1992

Selenium, glutathione peroxidase (GSH-Px) and lipid peroxidation products before and after selenium supplementation.

Treated phenylketonuric (PKU) children are at risk of selenium deficiency. We have studied 15 treated PKU children and 30 control children. We observed significantly lower (P less than 0.0005) plasma and erythrocyte selenium, as well as significantly lower (P less than 0.0005) plasma and erythrocyte glutathione peroxidase activities (GSH-Px) in PKU children than in controls. The lipid peroxidation products, evaluated as plasma malondialdehyde (MDA), was higher (P less than 0.0005) in PKU children than in controls. Specific oral sodium selenite supplementation (Selenium: 0.13 mumol/kg/day) resulted in a rapid increase of plasma selenium and GSH-Px activity, and after 10 days and 1 month respectively significant difference is no longer observed between PKU children and controls values. Statistically significant differences in erythrocyte selenium, erythrocyte GSH-Px activity and plasma MDA between PKU and control children disappear after respectively 2 months, 4 months and 6 months of selenium supplementation.

Child↗
PubMed1992

Determination of ultrafiltrable zinc in human milk by electrothermal atomic absorption spectrometry.

Percentages of non-protein-bound zinc in human milk have been reported by different workers, but ultrafiltration and zinc determination in human milk have not been comprehensively examined. However, zinc contamination and zinc membrane binding have been described for the determination of non-protein-bound zinc in serum. In this work, ultrafiltration was studied in terms of zinc contamination and zinc membrane binding. An MPS-1 micropartition system fitted with a YMT membrane was used. Zinc contamination was found to be less than 276 nmol dm-3 and the zinc recovery was 85 +/- 4%. The conditions for electrothermal atomic absorption spectrometry were also studied. The detection limit was found to be 26.4 nmol dm-3 and the upper linear range was 4 mumol dm-3. The precision varied from 3% (within-run) to 17% (between-run). The recovery of standard additions was 95 +/- 7% (n = 30, different human milk ultrafiltrate samples). Physiological values varied from 0.46 to 84 mumol dm-3 (4-56% of zinc in whole human milk). Expressed in mumol dm-3, zinc in human milk ultrafiltrate decreased slightly through the lactation period, whereas expressed as a percentage of the total zinc in milk, zinc in human milk ultrafiltrate remained constant from day 2 to day 69 post partum.

Adult↗