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Biomedical subjects

B Bousquet

Publications and source records attributed to B Bousquet.

At least 37 records · Page 2Linked to original sources
PubMed1997

Determination of the L-DOPA/L-tyrosine ratio in human plasma by high-performance liquid chromatography. Usefulness as a marker in metastatic malignant melanoma.

A first procedure was devised for determining 3,4-dihydroxyphenylalanine (L-DOPA) in human plasma by isocratic RP-HPLC coupled with electrochemical detection. A second procedure was devised for determining 3-hydroxyphenylalanine (L-tyrosine) in human plasma by isocratic RP-HPLC coupled with fluorescence detection. These methods were used to ascertain the L-DOPA/L-tyrosine ratio in plasma of patients with melanoma. Reference values were established by analysis of the L-DOPA/L-tyrosine ratio in the plasma of 35 normal healthy subjects. For 29 patients diagnosed as having melanoma without metastasis, the L-DOPA/L-tyrosine (11.96 x 10(-5) +/- 2.69 x 10(-5)) level was not significantly different from that of 35 normal controls (11.20 x 10(-5) +/- 2.92 x 10(-5)). However, this level was significantly increased (p < 0.05) in the plasma of 17 patients with developing metastasis (21.02 x 10(-5) +/- 4.68 x 10(-5)).

Biomarkers, Tumor↗
PubMed1992

Magnesium, total calcium, phosphorus, copper, and zinc in plasma and erythrocytes of venous cord blood from infants of diabetic mothers: comparison with a reference group by logistic discriminant analysis.

Concentrations of magnesium (Mg), total calcium (Ca), phosphorus (P), copper (Cu), and zinc (Zn) were investigated in plasma (Pl) and erythrocytes (Erc) of venous cord blood of 44 infants of diabetic mothers (IDMs). These same concentrations plus total glycohemoglobin and fructosamine were determined at delivery in a subset of 15 mothers of these infants. Mineral results for IDMs were compared with those for 66 apparently healthy newborns. The duration of gestation in the two groups was significantly different (P < 0.001). After adjustment for gestational age, the mean (+/- SD) differences between groups were significant for birth weight, head circumference, Erc-Mg (1.71 +/- 0.17 for IDMs vs 1.76 +/- 0.15 mmol/L for control subjects), Pl-Ca (1.96 +/- 0.32 vs 2.48 +/- 0.22 mmol/L), Pl-P (1.99 +/- 0.40 vs 1.57 +/- 0.25 mmol/L), and Erc-Cu (10.9 +/- 2.41 vs 12.9 +/- 3.00 mumol/L), but not for Erc-Zn (33.0 +/- 18.3 vs 40.4 +/- 13.6 mumol/L). The variable that best discriminated between the two infant groups after adjustment for gestational age was Pl-Ca. In the 15 mothers, Pl-Mg (0.67 +/- 0.07 mmol/L) and Pl-Ca (1.66 +/- 0.21 mmol/L) concentrations were low, Pl-Zn (9.81 +/- 3.40 mumol/L) was normal, and Pl-Cu (33.5 +/- 10.7 mumol/L) was above normal. Correlations between total glycohemoglobin and mineral values of the mothers or paired IDM mineral values were not significant. The concentration of Pl-Ca was positively correlated with Erc-Cu (P < 0.001) and Pl-Cu (P < 0.05) in the comparison group newborns but not in the IDMs.

Calcium↗
PubMed1992

Association between magnesium, calcium, phosphorus, copper, and zinc in umbilical cord plasma and erythrocytes, and the gestational age and growth variables of full-term newborns.

We determined reference values in umbilical cord plasma and erythrocytes for magnesium, total calcium, phosphorus, copper, and zinc, and then calculated correlations and stepwise-regression equations in 66 white full-term newborn infants (35 boys, 31 girls). Only infants meeting certain optimal criteria and benefiting from excellent maternal conditions and uncomplicated pregnancies were included. There were no significant sex-related differences at birth among the variables studied. Gestational age was positively correlated with erythrocyte zinc (P less than 0.001), and plasma calcium was positively correlated with erythrocyte copper (P less than 0.001). Plasma copper proved to be the most significant variable in the stepwise-regression equation for birth height as the dependent variable. The most significant regressors accounting for birth weight were erythrocyte zinc followed by plasma zinc.

Birth Weight↗
PubMed1988

Photoprotective effect of vitamins A and E on polyamine and oxygenated free radical metabolism in hairless mouse epidermis.

The purpose of this study was to confirm the photoprotective effect on skin of vitamins A and E, due to inhibition of polyamine synthesis and production of free radicals. These variables were measured in the lumbar epidermis of the female hairless mouse subjected to UVA + B irradiation. Polyamines were assayed in epidermal homogenate by HPLC, and production of oxygenated free radicals was determined by spectrofluorometric assay of malonyl dialdehyde. It was determined that butyl-hydroxy-toluene and vitamin E inhibited production of free radicals (56% and 60%, respectively) and caused a significant reduction in polyamine biosynthesis (P less than 0.01), whereas the inhibitory effect of malonyl dialdehyde induced by vitamin A (30%) had no associated effect on polyamine metabolism.

Animals↗
PubMed1988

[Determination of 3-methoxy-4-hydroxyphenyethylene-glycol and its urinary conjugates. Value in the diagnosis and therapeutic follow-up of depression].

In psychiatric illness like depression, difference is essential between noradrenergic and serotoninergic sources. Therefore the measurement of urinary excretion of MHPG (3-methoxy-4-hydroxy-phenylethylene-glycol) is interesting, because MHPG seems to be the best reflect of central noradrenergic activity. Analytical assay of MHPG includes an enzymatic hydrolysis and an extraction by ethyl acetate. Separation is conducted by HPLC with fluorometric detection for MHPG and VMA, and electrochemical detection for 5-HIAA, which measurement is simultaneous. Quality control is evaluated (detection limit, linearity, precision, reproducibility, hydrolysis and extraction efficiency). Control values of 15 healthy subjects are 18.9 +/- 8.0 mumol/24 h of total MHPG, 1.5 +/- 1.0 of free MHPG, 8.5 +/- 2.0 of sulfate, and 10.7 +/- 4.4 of glucuronide MHPG (m +/- 2 sigma). In our study on depression, the best biological witness seems to be the sulfate-MHPG: in 16 depressed patients without treatment, its rate is very lowered (1.2 +/- 1.2 mumol/24 h). Total and glucuronide MHPG decrease weaker than sulfate (respectively -51% and -65%), while free MHPG increases (+ 193%) versus controls. Urinary VMA and 5-HIAA, peripheric catabolites of respectively adrenalin and serotonin are not significantly altered. There is no correlation neither between urinary sulfate-MHPG and scale evaluation before treatment, nor between urinary sulfate-MHPG and clinic improvement after antidepressive treatment. At last, the association clomipramine + mianserine shows a clinic improvement faster than clomipramine only, although no significative difference appears in biological markers.

Clomipramine↗
PubMed1983

Low lead doses and atherogenic diet in rabbits: biochemical results in blood.

Changes in concentrations of blood lead, cholesterol, triacylglycerols, GOT and GPT enzymes, phosphorus, proteins, plasma calcium and magnesium, and erythrocyte magnesium were studied for 25 weeks in 4 groups of 6 rabbits each receiving different diets: I (controls), II (water with 9.66 mumol/l of lead), III (atherogenic) and IV (atherogenic + 9.66 mumol/l of lead). Differences observed, with respect to the diets, for lead, cholesterol, enzymes, proteins and erythrocyte magnesium were evident from the 42nd day on. Low lead doses raised the levels of cholesterol and triacylglycerols in group II, whereas triacylglycerols were lower in the plasma of group IV in comparison with group III and were accumulated in the aorta. The elevation of enzymes in groups III and IV indicated heart and liver dysfunctions. There was a significant drop in erythrocyte magnesium in groups III and IV, which was especially marked in the latter group, with an interaction between the two diets.

Alanine Transaminase↗
PubMed1981

Determination of 5-hydroxyindoleacetic acid in urine by high-performance liquid chromatography: a fully automated method.

High-performance liquid anion-exchange chromatography is combined with continuous flow spectrofluorometry at an optimized pH for the determination of 5-hydroxyindoleacetic acid (5-HIAA) in urine. Its chief advantages are speed (7 min per determination), enabling measurement of large series of samples, precision (coefficient of variation = 0.72%), sensitivity (detection limit: 1 pmol) and specificity (no interference with 5-HIAA precursors or with the drugs tested). Reference values (n = 112) are 25 +/- 25 mumol per 24 h. Comparison with a reference spectrofluorometric technique shows a correlation coefficient of 0.96.

Automation↗
PubMed1981

Reference values for ionized, complexed, and protein-bound plasma magnesium in men and women.

Of the three magnesium fractions in plasma, free ionized magnesium (Mg2+) has the greatest biological activity. Accordingly, information concerning this form in plasma is of cardinal importance to investigations in biometry and human pathology. For this reason, we developed an indirect assay for ionized magnesium in which Mg2+ is determined as the difference between ultrafiltrable magnesium, as measured in plasma water after ultracentrifugation, and complexed magnesium, as obtained after fixation of the ionized and protein-bound magnesium on Amberlite IR-120(H) cation-exchange resin. All magnesium assays were performed by atomic absorption spectrometry. We used this methodology to compare ionized, complexed, and protein-bound plasma magnesium in 34 normal men and 12 normal women. Sex-related differences between the values for these fractions were not significant. Interesting preliminary results for cases of myocardial infarction prompt us to continue our investigations concerning these three states of plasma magnesium in cardiac pathology.

Adult↗
PubMed1980

Concentrations of magnesium, calcium, potassium, and sodium in human heart muscle after acute myocardial infarction.

Atomic absorption spectrometry was used to measure magnesium, calcium, and sodium, and emission spectrometry to measure potassium, in myocardium (left and right ventricles) of 26 control subjects who died of acute trauma. Results were expressed in mumol/g of proteins. Mg/Ca and K/Na ratios were also determined. The same measurements were made in 24 patients who died from acute myocardial infarction. Samples were also taken from the necrotic area. Mg/Ca and K/Na ratios were significantly higher in the left ventricle of both populations, thus providing evidence of anatomical and physiological differences between the two ventricles. As a result of cytolysis and anoxia, the Mg/Ca ratio was very significantly inverted, and the K/Na ratio very significantly smaller, for samples from the necrotic area. In these clinical conditions arrhythmias could certainly be considered likely, and there is reason to believe that magnesium depletion may be a cause of arrhythmias.

Adolescent↗
PubMed1979

[Photosensitivity and disturbances of tryptophan metabolism (kynurenin pathway) (author's transl)].

We studied a bullous photodermatosis recurring for two years in a old woman. The eruption was diagnosed as a pellagra-like syndrome on tryptophan loading test disorders without any other cause of sun sensitivity. The static and dynamic metabolic investigation was centered on tryptophan and vitaminic coenzymes which mediate catabolic reactions. The defect are located on the kinurenin pathway. The discussion analyses the possible relations between the dermatosis and the biological disturbances observed.

Aged↗
PubMed1978

[Mechanism of induction of tyrosine in rat liver by phenothiazine derivatives and related chemical compounds].

Increase of hepatic tyrosine-alpha-ketoglutarate transaminase is observed in Rats (Wistar strain) after intraperitoneal administration of tricyclic compounds (phenothiazin and related structure derivatives). This is an induction process: actinomycine D inhibits this effect. This action is not mediated by glucocorticoids: induction persists in adrenalectomized Rats. The mechanism of action is different too: additive effects are found after simultaneous injection of glucocorticoid and tricyclic drug.

Adrenal Glands↗
PubMed1978

[Induction of hepatic tyrosine transaminase in rats by phenothiazine derivatives and analogs].

We have showed induction of tyrosine-alpha-ketoglutarate transaminase in hepatic cytosol of Rats (Wistar strain) five hours after intraperitoneal administration of tricyclic compounds (phenothiazine, iminodibenzyl, thioxanthene, thiophenylpyridylamin, dibenzocycloheptadiene, dibenzoxepin derivatives). Chemical structure of these molecules is very important: sulfur atom (phenothiazine, thioxanthene), some substituants like chlorine (chlorpromazine, chlorprothixene) and 2'-dimethylaminopropyl chain (promethazine) increase this inductive effect.

Animals↗
PubMed1978

[Spectrofluorimetric automatised assay of free and total tryptophan in plasma (author's transl)].

An automated fluorometric method, including norharmane transformation of tryptophan (TRP) by formaldehyde and perhydrol, is applied to free and total TRP determination in human plasma. Separation of free TRP determination in human plasma. Separation of free TRP is achieved by ultrafiltration at pH 7,25 under an air/CO2 flow. The procedure here described is easy, rapid and very sensitive, allowing to work on microsamples if free TRP separation could be realized with them. A correct precision is obtained (CV : 2,8% for plasma repetability) and the specificity is quite good in plasma according to the negligible effect of tryptamine. Frequent values, calculated from 19 healthy subjects are [mean +/- tSE (risk 5%)]:--free TRP : 11,8 +/- 1,5 mumol/l;--total TRP : 52,2 +/- 19,7 mumol/l.

Autoanalysis↗