Biomedical subjects

Yvon Lessard

Publications and source records attributed to Yvon Lessard.

3 recordsLinked to original sources

PubMed2006

Multimedia and physiology: a new way to ensure the quality of medical education and medical knowledge.

BACKGROUND: since the eighties and the existence of virtual campuses, the value of computers in distance education has been acknowledged. The development of information and communication technologies is driving at discriminating distance education and on-line education. PURPOSE: the aim of the "Campus Numérique de Physiologie" is not to reproduce an on-line copy of classical textbooks but to put at students' and physicians' disposal the huge possibilities of multimedia resources for an active and easier understanding of complex physiopathological phenomena. METHODS: the on-line course materials were created using both original IBC-made and registered trade-mark software tools. Multiscale modelling and corresponding knowledge bases were implemented by mathematicians, biologists and software engineers from Rennes. The website, which is accessible through a server of the French Virtual Medical University, was developed in the language HTML/PHP connected to a MySQL database. RESULTS: the content managing system is consistent with classical home page facilities and multicriteria browser. Interactive resources are freely available for the site's users. Two- and three-dimensional simulations born out of mathematical qualitative and quantitative models at the molecular, cellular or organic level keep students active with regards to fundamental mechanisms by interactively manipulating the simulation environment. CONCLUSION: authors comment the already available course materials which should stimulate the creation of new documents following a validation by a qualified commission of the "Société de Physiologie". Providing evaluation tests, teachers anticipate that the increasing content of this virtual campus will allow users to gain a complete understanding and an integrative view of many physiopathological mechanisms.

Education, Distance↗

PubMed2002

Effects of epinephrine compared with the combination of dobutamine and norepinephrine on gastric perfusion in septic shock.

OBJECTIVE: In septic shock, the alteration of the gut barrier contributes to the development of multiple organ failure. The aim of the study was to compare epinephrine with the combination of dobutamine and norepinephrine on gastric perfusion in patients with septic shock. METHODS: In a prospective randomized study on 2 parallel groups, systemic and pulmonary hemodynamics (arterial and Swan-Ganz catheters), gastric mucosal blood flow (laser Doppler flowmetry technique), hepatic function (indocyanine green clearance), and blood gases were evaluated just before catecholamine infusion and when mean arterial pressure reached 70 to 80 mm Hg. Epinephrine or norepinephrine were titrated (from 0.1 microg/kg per minute, with 0.2 microg/kg per minute increases every 5 minutes). Dobutamine was continuously infused at 5 microg/kg per minute. RESULTS: Twenty-two patients were included (11 in each group). At randomization there was no significant difference between groups. At the time of evaluation, mean arterial pressure was 78 +/- 3 and 77 +/- 5 mm Hg in the epinephrine and dobutamine-norepinephrine groups, respectively. There was no significant difference between groups regardless of the systemic and pulmonary hemodynamic or blood gas variable considered. Nevertheless, compared with dobutamine-norepinephrine, epinephrine tended to induce greater values for cardiac index (5.0 +/- 1.6 versus 4.2 +/- 1.5 L/min per square meter; P =.078) and oxygen transport (617 +/- 166 versus 481 +/- 229 mL/min per square meter; P =.068). Epinephrine also induced significantly greater values of gastric mucosal blood flow (662 +/- 210 versus 546 +/- 200 units; P =.011) but did not modify indocyanine green clearance. CONCLUSIONS: In patients with septic shock, at doses that induced the same mean arterial pressure, epinephrine enhanced more gastric mucosal blood flow than the combination of dobutamine at 5 microg/kg per minute and norepinephrine. This effect was probably a result of higher cardiac index.

Adrenergic alpha-Agonists↗

PubMed2002

Pharmacogenomics.

Pharmacogenomics, a revolutionary chapter in the history of pharmacology, has received new impetus from the development and accessibility of molecular biotechnologies, notably DNA chips. The longstanding notion of responders/non-responders has given way to a more organic approach, where idiosyncrasy becomes an obsolete concept. This is a major step towards predictive, individualized medicine. In this review, several applications of pharmacogenomics are considered. Genetic polymorphisms of metabolization reactions, mainly with cytochrome P450, explain most of the cases described today. More fundamental and innovative studies have tried to link the structure of receptors or transporters and drug response. A leading topic in neuropsychopharmacology is the relation between the polymorphism of dopaminergic receptors and the efficacy of, or adverse reaction to, neuroleptics. In asthma, the structure of the beta2-adrenergic receptor has been associated with response to treatment. Intrinsic genetic predisposition also plays an important role in cardiovascular diseases, and the role of ion channel mutations will be discussed. Research in oncological molecular epidemiology has explored the connection between the predisposition to certain cancers and specific enzymatic equipment hindering the detoxification of potentially carcinogenic exogenous compounds, or, on the contrary, promoting metabolic activation implicated in the formation of reactive compounds. The search for determinants of addictive behavior is another vast field of pharmacogenomics. Finally, we consider the impact of pharmacogenomics on the methodology of drug development in preclinical and clinical trials. Progress in methods of phenotyping/genotyping should promote diagnosis, guide the choice of drug for an individual (benefit/risk ratio), and determine dosage and regimen.

Cardiovascular Physiological Phenomena↗