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Biomedical subjects

P Chappuis

Publications and source records attributed to P Chappuis.

At least 55 records · Page 3Linked to original sources
PubMed1988

Analytical problems encountered in determining aluminum status from hair in controls and hemodialyzed patients.

The problems involved in evaluating aluminum concentrations in hair are reviewed, especially those concerning removal of contaminating metals, a critical factor. In the few published studies of Al concentrations in hair, acetone was usually used for its removal. Here, its use in the washing sequence was found to give less precise results and higher Al values than the use of isopropanol. With isopropanol, the whole analysis can be done in a single tube. We compared results with those in the literature. We found that the Al concentration in the hair of control subjects was not related to sex or hair color and that there was a highly significant (P less than 0.001) difference between values for control subjects and hemodialyzed patients: 126 (SD 58) nmol/g, n = 49, vs 226 (SD 104) nmol/g, n = 39, respectively.

1-Propanol↗
PubMed1987

Se, Zn, Mg, Ca, K, cholesterol, and creatine kinase concentrations in men during the 12 days after an acute myocardial infarction.

We determined concentrations of selenium, zinc, magnesium, calcium, potassium, total and high-density lipoprotein cholesterol, and total creatine kinase (EC 2.7.3.2) in plasma (P) and (or) erythrocytes (E) of 32 men at the time of hospital admission for acute myocardial infarction and then on subsequent days 2, 3, 6, 10, and 12. During these 12 days, only P-selenium and high-density lipoprotein cholesterol concentrations remained unchanged. For the other variables, individual comparison of means indicated the dates of significant changes in concentration (p less than 0.05).

Adult↗
PubMed1986

[Methods of determination of selenium in biological matter].

Main techniques used: graphite furnace atomic absorption direct or after preliminary treatment of the sample, graphite furnace atomic absorption by generation of hydrides, fluorometry, gaz chromatography, differential pulse voltammetry. The various quality criteria of these methods are compared as well as the usual values in the different biological fluids (whole blood, plasma, serum, erythrocytes, urine).

Chromatography, Gas↗
PubMed1983

[Evaluation of the treatment of symptomatic urinary tract infection with a single dose of antibiotics or bicarbonate].

68 women with acute, uncomplicated urinary tract infection confirmed bacteriologically were randomized to receive either a single oral dose of cotrimoxazole, a single oral dose of amoxycillin, or an oral dose of Na-bicarbonate. Results comparable to previous reports were obtained with the cotrimoxazole regimen. On the other hand, the efficacy of single-dose amoxycillin appeared to be inferior. It is possible that pharmacocinetic differences influence the efficacy of these drugs.

Adult↗
PubMed1983

[Assay of serum selenium by atomic absorption spectrophotometry. Value in the biological diagnosis of nonobstructive cardiomyopathies].

The authors present a technique of direct assay of serum selenium by atomic absorption spectrophotometry, using electrothermal atomization in a graphite oven. The initial results of the assays performed in patients with non-obstructive cardiomyopathies (NOCM) reveal a decrease in the serum selenium level. This element could therefore represent a laboratory marker for these diseases.

Cardiomyopathies↗
PubMed1981

[Determination of the serum concentration of lipoproptein x (author's transl)].

Lipoprotein X (LPX) is a cholestase marker. The authors wish to set forth a simple and quick method for the quantity determination of this abnormal--a method which could be combined with other biochemical tests permitting the demonstration and monitoring of a cholestatic syndrome. The phospholipid composition of lipoprotein X is thought to be constant; therefore, the proposed method of quantity determination consists in an enzymatic quantity determination of phospholipids, performed on the lipoprotein, isolated from the normal serum lipoproteins by means of a simple operative protocol: elimination of the LDL and VLDL by means of immuno-precipitation, followed by separation of the HDL by means of the action of phosphotungstate. In addition to its quantitative characteristic, the proposed method has been shown to be more selective than the traditional demonstration which uses electrophoresis on agar. This electrophoretic research can in effect, show itself to be negative if practised on biological samples which are rich in biliary acids or free fatty acids; conversely, the operative protocol described permits the demonstration of the quantification of lipoprotein X.

Biliary Tract Diseases↗
PubMed1976

Thermic effect of glucose in obese subjects studied by direct and indirect calorimetry.

1. The thermic effect of a glucose load (50 g) was studied in ten control and eleven obese female subjects, using both direct and indirect calorimetry simultaneously. Experiments were done under conditions of thermal equilbrium (28 degrees and 30% relative humidity). 2. Thermal balance (heat production measured by indirect calorimetry minus heat losses measured directly) was negative in the control group during the fasting period (heat deficit -14-2 +/- 5-0 kJ/m2 per h), whereas that of the obese group was in equilibrium (+ 1-4 +/- 4-8 kJ/m2 per h). 3. After the glucose load, metabolic rate increased 13-0 +/- 1-5 and 1-3% in the control and obese groups respectively. 4. In contrast to the metabolic rate, total heat losses were not significantly altered in either group after the glucose load. Total heat losses of the obese group were significantly lower than those of the control group throughout the experimental period. 5. During the experiments the amount of heat stored was increased in both groups. Thermal balance in the control group became positive while that of the obese group remained positive. 6. During the fasting period, the control subjects oxidized more carbohydrates (90-4 mg/min) than lipids (68-8 mg/min), whereas obese subjects oxidized more lipids (103-7 mg/min) than carbohydrates (50.2 mg/min). After the glucose load, the oxidation rate of carbohydrates was increased in both groups to 158-1 mg/min in control subjects and 95-6 mg/min in obese subjects. 7. The mean skin temperature of the control subjects was significantly higher than that of the obese subjects and remained higher throughout the postprandial period. 8. These results indicate that: (a) during the fasting period, the energy sources utilized and the thermal balance of the two groups were different; (b) the thermic effect of glucose was less in the obese subjects and, therefore, might be a factor contributing to their low energy expenditure.

Adult↗
PubMed1976

Heat storage regulation in exercise during thermal transients.

Rate of heat storage (S) was measured by using direct and indirect calorimetry simultaneously in 11 subjects during rest and exercise at three ambient temperatures (Ta of 20, 25, and 30 degrees C), and at two work intensities (40 and 90 W). At rest, the mean value of S was -64.9 W at 20 degrees C, -26.1 W at 25 degrees C, and +9.9 W at 30 degrees C. After 50 min of exercise at 40 or 90 W, S tended toward zero at the three ambient temperatures. This indicates that thermal equilibrium was reached. In addition, at the end of the exercise periods total heat losses (R + C + E) measured at a Ta of 20, 25, and 30 degrees C were similar, i.e., independent of Ta. During the thermal transients and the steady state of exercise, the calorimetric method allows immediate measurement of S to be made, since all the physical terms of the body heat balance equation are determined. The changes in mean body temperature (delta Tb) measured by thermometry showed a delay of 5-10 min when compared with delta Tb measured by calorimetry. Thus, determination of delta Tb by thermometry is not directly applicable during thermal transients, unless the observed delay is taken into account. Our results also support the concept that Tb may be the regulated variable of the thermoregulatory system, since we obtained a very significant and uniform correlation between Esk and delta Tb at the three Ta and the two work intensities which were studied.

Adult↗
PubMed1975

Interactions of insulin and epinephrine in human metabolism: their influence on carbohydrate and lipid oxidation rate.

Two groups of normal male subjects were given an infusion of insulin and an infusion of epinephrine + insulin respectively. Blood glucose, plasma free fatty acids (FFA), insulin, growth hormone, cortisol, and urinary catecholamines were determined. Continuous indirect calorimetry was used to measure metabolic rate and oxidation rates of carbohydrate and lipids. The first group (n equals 7) received a 30-minute insulin infusion (0.1 IU/kg). While blood glucose and plasma FFA decreased, carbohydrate oxidation and metabolic rate significantly increased after some delay, whereas lipid oxidation decreased. The increase in carbohydrate oxidation amounted to 5 g/120 min. The decrease in blood glucose during insulin administration did not correlate with the increase in carbohydrate oxidation. In the second group (n equals 7), a 150-minute epinephrine infusion (900 mug in 500 ml saline) was administered, and superimposed upon it, a similar insulin infusion initiated after 60 min. Epinephrine alone increased blood glucose and plasma FFA levels, and decreased insulinemia. The rise in the metabolic rate was sharp and significant. After a short but significant increase the oxidation rate of carbohydrate decreased, whereas that of lipids markedly rose. This increase significantly correlated with that in FFA. Addition of insulin markedly decreased the elevated FFA levels and lowered blood glucose. After some delay this was followed by a marked increase in carbohydrate oxidation and a decrease in lipid oxidation. In this test the total increase in carbohydrate oxidation was 11 g/120 min. In comparison with the insulin test, this double amount seems to correlate well with the higher blood glucose levels measured before insulin administration. The results suggest that insulin indirectly stimulates carbohydrate oxidation by facilitating glucose transport into the cells and lowering FFA levels, and that epinephrine favours lipid oxidation through its lipolytic effects and its suppression of insulin release.

Adult↗
PubMedDate not supplied

Physiological chromium determination in serum by Zeeman graphite furnace atomic absorption spectrometry. A serious challenge.

Several authors have already underlined chromium implication in glucose and lipids metabolism of humans. In this field, physiological chromium determination in serum could be helpful, but the discrepancies reported in numerous papers are confusing. Here we report some results obtained by Zeeman correction Graphite Furnace Atomic Absorption Spectrometry. This technique includes a dilution of serum with 12.5 mM ultrapure nitric acid and 0.25% Triton X-100 (final concentrations). Some main features can be outlined: (1) the contamination constitutes a serious drawback and (2) the sensitivity of the technique is critical (characteristic mass found: 1.76 pg/0.0044 A.s). Our results obtained from 27 healthy subjects (2.01 +/- 0.77 nmol/L) agree with most recent studies and indicate that serum chromium level does not seem to be sex-related.

Chromium↗