References of "Gérard, Paul"
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See detailComparison between Three- and Four-Element Windkessel Models to Characterize Vascular Properties of Pulmonary Circulation
Lambermont, Bernard ULg; Gérard, Paul ULg; Detry, Olivier ULg et al

in Archives of Physiology & Biochemistry (1997), 105(7), 625-32

In 11 anaesthetised pigs the accuracy of the three-element (WK3) and the four-element (WK4) Windkessel models to describe hemodynamic properties of the pulmonary circulation was compared during six ... [more ▼]

In 11 anaesthetised pigs the accuracy of the three-element (WK3) and the four-element (WK4) Windkessel models to describe hemodynamic properties of the pulmonary circulation was compared during six different experimental conditions increasing pulmonary arterial pressure: increase in left atrial pressure, increase in alveolar pressure, increase in pulmonary blood flow, endotoxin shock, mechanical obstruction of left pulmonary artery or histamine infusion. Our results showed that WK4 fitted better the data than did WK3 because values of 1-R2 decreased from 6 percent (WK3) to 1.4 percent (WK4) when WK4 was used (P < 0.0005). 1-R2 was an adequate marker of the accuracy of the linear regression used to solve equations of both models. Compliance values estimated by WK4 were decreased by 5% comparatively to WK3 (P = 0.008). However, this difference can be considered as not physiologically relevant. Values of characteristic resistance corresponding to R1 + (L/R2C) in WK4 and to R1 in WK3 were not different (P = 0.22). The relative changes in R1, R2, and C observed due to the different experimental conditions were comparable regardless of the model. In conclusion, the conversion of WK3 in WK4 by adding an inductance, whose physiological meaning is not clear, resulted in an increased statistical accuracy of the model, but did not seem to have relevant influence on parameters or their evolution during experimental conditions. [less ▲]

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See detailHigh-rate of multiple genital HPV infections detected by DNA hybridization
Lauricella-Lefèbvre, M. A.; Piette, Jacques ULg; Lifrange, Eric ULg et al

in Journal of Medical Virology (1992), 36(4), 265-270

Cervical smears collected from 450 patients involved in a clinical follow-up of cervical human papillomaviruses (HPV) infections were screened for the presence of HPV 6b, 11, 16, and 18 DNA by both dot ... [more ▼]

Cervical smears collected from 450 patients involved in a clinical follow-up of cervical human papillomaviruses (HPV) infections were screened for the presence of HPV 6b, 11, 16, and 18 DNA by both dot blot and southern blot hybridization methods. Using very high stringency hybridization assays, the four HPV types could be easily distinguished by dot blotting. After a preliminary clinical sorting, 42.9% of the samples were found to be HPV-positive. Among the samples infected by a single HPV, type 16 was the most frequent (25.4% of the positive samples) followed by 6b (19.7%), 11 (8.3%), and 18 (7.2%). Double or even multiple infections by the different HPV types were detected at a very high rate (39.4% of the positive samples). [less ▲]

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See detailIdentification of Three-Element Windkessel Model: Comparison of Time and Frequency Domain Techniques
Pochet, T.; Gérard, Paul ULg; Marnette, J. M. et al

in Archives Internationales de Physiologie, de Biochimie et de Biophysique (1992), 100(3, May-Jun), 295-301

The problem of the parameter identification of the three-element windkessel model is studied. Minimization by least-square technique--LSQ--in time domain and frequential techniques--FFT--are compared ... [more ▼]

The problem of the parameter identification of the three-element windkessel model is studied. Minimization by least-square technique--LSQ--in time domain and frequential techniques--FFT--are compared. Continuous pressure and flow curves were recorded in the proximal aorta of an open chest dog. Comparison shows very high correlations between the parameter estimations obtained by LSQ and FFT methods. However, systematic differences appear between the calculated values, but do not seem to endanger physiological interpretation of the results. [less ▲]

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See detailElucidation of non-parallel EIA curves
François-Gérard, C.; Gérard, Paul ULg; Rentier, Bernard ULg

in Journal of Immunological Methods (1988), 111(1), 59-65

Quantitative determinations by EIA can be only obtained by reverse regression when linear portions of sample and standard curves are parallel. However, analysis of complex biological fluids often yields ... [more ▼]

Quantitative determinations by EIA can be only obtained by reverse regression when linear portions of sample and standard curves are parallel. However, analysis of complex biological fluids often yields sigmoid curves displaying lower slopes, thus invalidating any quantitative interpretation. We hypothesized that this phenomenon was due to a competition effect between the target (for example an antigen) and related molecules for the binding sites (for example a capture antibody) immobilized onto the solid phase. This has been confirmed experimentally using various target-to-competitor ratios and formulated as a mathematical model. The slope decrease in target detection was related to the proportion of competitor, not in a linear, but in an exponential manner. This mathematical model has been computerized and can be used to correct aberrant sample curves provided the relevant parameters have been previously determined in the same systems. A competition effect should be suspected whenever non-parallel EIA sigmoid slopes are obtained. [less ▲]

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See detailProblems in quantitation of anti-viral IgG isotypes: a computerized mathematical model
Rentier, Bernard ULg; Francois-Gerard, C.; Gérard, Paul ULg

in Charbonneau, K. (Ed.) Abstracts : sixth international congress of immunology, July 6-11,1986, Toronto, Canada (1986)

Detailed reference viewed: 2 (0 ULg)