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P Aymard

Publications and source records attributed to P Aymard.

At least 37 records · Page 2Linked to original sources
PubMed1993

Impaired duodenal response to short-term dietary calcium restriction in adolescent spontaneously hypertensive rats.

The response pattern of plasma calcitriol level and related intestinal adaptation to short-term moderate calcium (Ca) restriction was examined in adolescent male, spontaneously hypertensive rats (SHR) and normotensive WKY control rats. Twelve-week-old SHR and WKY fed a low (0.1%) Ca diet for 3, 6, or 12 days were compared with rats of either strain fed a normal (1.0%) Ca diet. Plasma calcitriol response was measured and duodenal adaptation to Ca restriction was investigated by evaluating active Ca transport, calbindin-D9K (CaBP9K) protein, CaBP9K mRNA, and alkaline phosphatase activity (ALP). Under the normal Ca diet, no significant difference between strains was observed for all five parameters. In response to the low Ca diet, the SHR and WKY showed a similar increase (nearly 50%) in plasma calcitriol, starting at day 3 of this diet. However, only the WKY displayed the expected duodenal adaptation: active Ca transport increased at day 6 and CaBP9K as well as ALP increased at day 3 of the low Ca diet. The stimulation of the latter three parameters was maintained until day 12 of Ca restriction. Moreover, CaBP9K mRNA was increased in WKY after 3 days of Ca restriction. In contrast, the SHR had either no or only a minor increase of duodenal parameters in response to Ca restriction. Finally, a significant and positive correlation between Ca transport and plasma calcitriol and between Ca transport and CaBP9K was found in WKY but not in SHR.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1992

Different forms of alkaline phosphatase in adult rat femur. Effect of a vitamin D3-deficient diet and of a sorbitol-enriched diet.

In the femoral extremities of the adult rat containing the metaphysis, the epiphyseal cartilage, and the epiphysis, four alkaline phosphatase (AP) forms were distinguished on polyacrylamide gel electrophoresis. Two soluble forms were present in the 160,000 g supernatant: one of Mr 165 kDa and another of Mr 110-115 kDa, which exhibited a strong catalytical activity. Moreover, from the pellet, three membrane-bound forms of Mr 130, 110-115, and 100 kDa could be extacted with sodium deoxycholate. When denaturated AP was visualized by postelectrophoretic autoradiography of the phosphorylated intermediates, subunits always appeared as three monomers of Mr 75-80, 60-70, and 50-60 kDa. As four native forms but only three types of subunits were found to be present in the femur, it seems that, apart from homodimers, some heterodimers could also occur. Three types of diets were administered to three groups of rats for 5 weeks. Two are known to disturb bone mineralization: (1) a vitamin D3-deficient diet, and (2) the same as (1) but enriched with 12% sorbitol. The third was a normal diet containing vitamin D3. Concerning the effects on AP of dietary sorbitol and the vitamin D3-deficient diet, it was found that rats receiving the diet supplemented with sorbitol showed a substantial rise in the activity of the Mr 165 kDa form with the concomitant appearance of a new monomer of Mr 100 kDa. In contrast, rats fed the vitamin D3-deficient diet always displayed an increase in enzyme activity, principally of the Mr 100 and 110 kDa forms.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1992

In vitro inhibition of alkaline phosphatase activities from intestine, bone, liver, and kidney by phenobarbital.

A kinetic study of the inhibition of several alkaline phosphatase (AP isoenzyme activities by phenobarbital was carried out using p-nitrophenylphosphate (10 mM) as a substrate at pH 9.8 in a 300-mM Hepes buffer. AP from bovine kidney, calf intestine, bovine liver, and rat bone was used. Over a phenobarbital concentration range of 20-400 mM, all these isoenzymes were inhibited in an uncompetitive manner with a Ki of 200 mM for intestinal AP, and in a linear mixed-type manner for all the other isoenzymes tested. The Ki values were 10, 40 and 55 mM for kidney, bone and liver AP, respectively. The use of 15 mM carbonate-bicarbonate or 400 mM diethanolamine buffer did not modify the degree of inhibition of intestinal AP activity. Dixon plots of the reciprocal of reaction velocity versus inhibitor concentration either at different substrate concentration or at different DEA concentration indicate uncompetitive inhibition for the intestinal enzyme. This in vitro inhibitory effect of phenobarbital is in contrast to its in vivo stimulating action on AP. However, in the whole animal, the effects of phenobarbital administration probably represent the sum of multiple effects.

Alkaline Phosphatase↗
PubMed1991

Enzyme immunoassay of serum erythropoietin in healthy children: reference values.

A solid phase enzyme immunoassay for erythropoietin which required only a small specimen of blood was evaluated. It permitted measurement up to 150 IU/L. Recovery was between 86.2% and 110.0% and between-batch precision between 4.7% and 5.7%. We determined the levels of erythropoietin in infants aged 10 months (geometric mean 11.2 IU/L; 95% range 3.6-34.9) and in children aged 2 years (geometric mean 10.5 IU/L; 95% range 4.3-25.8). Both were significantly higher than the values found in children aged 4 years (geometric mean 7.2 IU/L; 95% range 2.4-21.8). There were no differences between the values in children at 4 years, those aged 4-15 years and adults.

Adolescent↗
PubMed1990

Usefulness of a prognostic inflammatory and nutritional index in pediatric clinical practice.

The clinical usefulness of a prognostic inflammatory and nutritional index (PINI) was evaluated in 47 hospitalized infants and 72 age-matched controls from 1 mth to 14 yr of age. The PINI formula is a combination of two markers each of infection (C-reactive protein and orosomucoid) and of malnutrition (albumin and transthyretin). Healthy children are identified by a PINI value less than 1 whereas sick patients are characterized by a progressive rise above 1 as the conditions worsens. The PINI scoring system provides the clinician with a sensitive and universal tool, allowing the correct follow-up of both inflammatory and nutritional poles of the disease spectrum. The formula is of particular help in pediatric practice in recognising early subclinical complications and efficacy of specific therapeutic strategies. The micromethod is simple, rapid and may be regularly repeated since it requires only 46 microliters of serum.

Adolescent↗
PubMed1989

Circadian variations and reference intervals for some enzymes in urine of healthy children.

Circadian variations of alanine aminopeptidase (EC 3.4.11.2), gamma-glutamyltransferase (EC 2.3.2.2), and N-acetyl-beta-glucosaminidase (EC 3.2.1.30) in urine were studied in 10 healthy children, ages six to 15 years. Urine specimens were collected during 24 h, grouped into four time intervals. Enzymes were measured spectrophotometrically, with automation. These enzymes all showed diurnal variation, with morning (8 a.m.-12 noon) excretion being highest. We also analyzed timed urinary specimens (8 a.m.-12 noon) from 136 healthy children, ages two to 11 years. Reference intervals are presented for these enzymes. High excretion of the three enzymes was observed in children two and three years old.

Acetylglucosaminidase↗
PubMed1989

[Optimization of the determination in urine of alanine aminopeptidase, gamma-glutamyltransferase and N acetyl-beta-D-glucosaminidase].

The authors describe the optimization of determination of alanine aminopeptidase (AAP), gamma-glutamyltransferase (GGT) and N-acetyl-beta-D-glucosaminidase (NAG) in urine by multivariate analysis. The optimal conditions found are: for AAP at 30 degrees C TRIS HCl buffer 300 mmol/l pH 7.9, L-alanine-4-nitroanilide 5.8 mmol/l, for GGT at 30 degrees C buffer glycylglycine 150 mmol/l pH 8.0, gamma-L-glutamyl-3-carboxy-4-nitroanilide 9.0 mmol/l, for NAG at 37 degrees C citrate buffer 50 mmol/l pH 5.8, m cresolsulfonphtaleinyl-N-acetyl-beta-D-glucosaminide 5.5 mmol/l. These methods are easy to perform, apply to urine without pretreatment through Sephadex: therefore complete automatization is possible. The stability of enzymatic activities in urine is of ten days at +4 degrees C in the presence of sodium azide at neutral pH. Freezing resulted in a considerable loss of activity for AAP and GGT.

Acetylglucosaminidase↗
PubMed1989

Determination of trans-phylloquinone in children's serum.

By optimizing the conditions for determining trans-phylloquinone and its metabolite, K-2,3-epoxide, in serum through a two-step HPLC process combined with fluorometric detection after coulometric reduction, we have been able to develop a method applicable to small volumes of serum (200 to 500 microL). The limit of detection (signal-to-noise ratio of 3) was 15 ng/L for trans-phylloquinone, 30 ng/L for K-2,3-epoxide. The trans-phylloquinone concentrations measured by this method in serum from 82 children, ages one to six years, whose results were normal for overall coagulation tests, ranged from 40 to 880 ng/L (median 175 ng/L). We discuss these findings and compare them with vitamin K1(20) values reported for adults.

Child↗
PubMed1989

Automated determination of urinary Na+, K+, chloride, inorganic phosphate, urea, and creatinine without sample dilution, with the "RA-XT".

We describe how concentrations of chloride, urea, inorganic phosphate, and creatinine in urine can be measured directly, without manual sample dilution, in a discrete analyzer (the Technicon "RA-XT"). These methods were accurate for concentrations of chloride up to 280 mmol/L, urea up to 500 mmol/L, inorganic phosphate up to 50 mmol/L, and creatinine up to 30 mmol/L. CVs are less than 3% nd results correlate well with those obtained by continuous-flow analysis (SMA-II). All these reagents are stable at room temperature for three weeks. Analyses are easy to perform and infrequent calibration is required.

Autoanalysis↗
PubMed1987

[Allergologic investigation of asthma in infants. Apropos of 153 cases of infants aged 5 to 36 months].

153 asthmatic children from 5 to 36 months (mean age: 26 months) were investigated. The aim of the study was twofold: 1) to determine the reliability and limits of an allergologic diagnosis before 36 months of age; 2) to compare the predictive value of skin-tests with other allergologic tests. Results were expressed according to a score involving 5 parameters derived from the allergologic investigation. Each parameter represented one point: atopic past history, increased level of total IgE antibodies related to the age, presence of blood specific IgE antibodies, blood hypereosinophilia. Infants were considered allergic if their score level was greater than or equal to 3. Concordance between this score level and each parameter was as follows: Positive skin-test 83%; Blood hypereosinophilia 82%; Presence of specific IgE antibodies 80%; Increased level of total IgE 78%; Familial history of atopy 54%. It is concluded that, in allergic infants, a significative link exists between positive skin-test plus the presence of specific IgE antibodies and an atopic disease. However, more children have to be enrolled in a multivariant analysis to assess definitively the predictive value to this score.

Asthma↗
PubMed1986

Concurrent immunoassay of C-reactive protein and orosomucoid by random-access analysis.

We describe turbidimetric methods for simultaneously determining C-reactive protein and orosomucoid in 33 microL of undiluted serum in the Technicon RA-1000, with multipoint calibration. Precision is good and results correlate favorably with those of nephelometry with the Beckman ICS (r = 0.98 for CRP, 0.99 for orosomucoid). Analyses are easy to perform, require infrequent calibration, and are suitable for routine and emergency analysis.

Autoanalysis↗
PubMed1986

[Experimental study in the rabbit of the effect of cholestyramine in the treatment of infectious diarrhea caused by cholera].

Cholestyramine is a non-absorbable anion exchange resin. Cholestyramine treatment of new born's infectious diarrhea has been shown to be effective. Cholera toxin induces, in the adult rabbit ileal loop, histological, water electrolytes and enzymatic modifications similar to that observed in patients with acute infectious diarrhea. Using this experimental model, we try to exhibit the reduction of the pathologic secretory action of the toxin on intestinal loop, after contact with the resin. A prolonged contact of the cholera toxin with the resin does not abolish completely the activation of adenyl-cyclase induced by the toxin alone. However significant reduction of goblet cell degranulation, and of the secretory effect allowed to reduce the loss of water and electrolytes.

Animals↗