Thesis (Ph.D.)--Pacific Graduate School of Psychology, 1991. / Source: Dissertation Abstracts International, Volume: 52-06, Section: B, page: 3284. Chair: Amy Wisniewski.

Thesis (Ph.D.)--Pacific Graduate School of Psychology, 1993. / Source: Dissertation Abstracts International, Volume: 54-12, Section: B, page: 6464.

No / Background Hyperhomocysteinaemia is an independent risk factor in the development of cardiovascular disease. Although homocysteine has been shown to affect endothelial cell function, the mechanisms by which it induces disease states are still poorly understood. Here, we report the ability of homocysteine to influence inflammatory cytokine/chemokine production by human saphenous vein endothelial cells, peripheral blood monocytes and monocyte-derived macrophages. Methods Human saphenous vein endothelial cells, peripheral blood monocytes and monocyte-derived macrophages were treated with homocysteine (0.1-5 mmol/L) for 4 and/or 24 h. Tumour necrosis factor (TNF)-¿, interleukin (IL)-1ß, IL-6 and IL-8 production was measured in the cell culture media using commercially available enzyme-linked immunosorbent assays. Results Interleukin-6 production by human saphenous vein endothelial cells was significantly stimulated following a 24-h treatment with homocysteine, whilst IL-8 concentrations were inhibited after both 4- and 24-h treatments. Homocysteine was also found to stimulate IL-1ß production by human peripheral blood monocytes and TNF-¿ production by monocyte-derived macrophages. Conclusions Overall, results from this study suggest that homocysteine alters the profile of cytokine/chemokine production by endothelial cells and macrophages. This altered profile may be important in the inflammatory events that initiate or enhance the development of atherosclerotic lesions.

L’évaluation externe de la qualité (EEQ) est un outil indispensable qui permet au laboratoire d’analyse de biologie clinique de surveiller la qualité de ses analyses. Une analyse rétrospective sur 391 893 résultats appartenant à sept analytes fréquemment dosés (glucose, calcium, triglycérides, créatine kinase, hémoglobine, HbA1c et protéines urinaires) a été réalisée sur une période de douze ans, de 1996 à 2007. Pour trois analytes, les résultats accumulés par trois Centres européens suisse, français et belge organisant des EEQ ont été comparés. Une approche statistique simple non paramétrique a été utilisée afin de calculer les performances (CV % et pourcentages de résultats conformes interlaboratoires) en incluant tous les résultats des EEQ, y compris les valeurs aberrantes. Le travail a permis de calculer les performances des appareils en fonction des analytes, de comparer les performances entre les Centres et entre deux types d’utilisateurs – les laboratoires professionnels et les cabinets médicaux – et, enfin, de calculer l’évolution des performances dans le temps. Il en ressort que les performances entre les Centres sont comparables et les appareils des laboratoires professionnels obtiennent de meilleures performances par rapport aux petits analyseurs utilisés dans les cabinets médicaux.Concernant les POCT, les performances ne dépendent pas du type d’utilisateur mais du type de POCT : certains obtiennent des performances comparables aux appareils de laboratoire, d’autres inférieures. Globalement, une amélioration des performances est mesurée pour les deux types d’utilisateurs, pour la plupart des appareils et pour tous les analytes. / The external quality assessment (EQA) is an essential tool that allows medical laboratories to supervise the quality of their analyses. A retrospective analysis on 391.893 results originating from seven frequently measured analytes (glucose, calcium, triglycerides, creatine kinase, haemoglobin, HbA1c, and urinary proteins) was performed over a twelveyear period, from 1996 to 2007. For three analytes, the results accumulated by three European Centres – Swiss, French, and Belgian – organising EQA surveys were compared. A simple non-parametrical statistical approach was used to calculate the performances (inter-laboratory CV% and percentage of correct results) in order to include all EQA results, even aberrant values. The work allowed to calculate the performances of devices for the different analytes, to compare performances among the Centres and among two types of users – professional laboratories and medical offices – and, finally to calculate the evolution of performances over time. It turns out that performances among the Centres are comparable and that professional laboratory devices obtained better performances as compared with small laboratory devices used in medical offices. Concerning POCT devices, performances are not linked to the type of user but to the POCT type : certain types reach the same performances as laboratory devices, while others are below. A general improvement of performances is measured for both types of users, for most devices, and for all the analytes.