Trust and Its Role in the Medical Encounter.

This paper addresses two research questions. The first is theoretical: What is trust? In the first half of this paper we present a distinctive tripartite analysis. We describe three attitudes, here called reliance, specific trust and general trust, each of which is characterised and illustrated. We argue that these attitudes are related, but not reducible, to one another. We suggest that the current impasse in the analysis of trust is in part due to the fact that some writers allude to these distinctions, but unclearly so, whilst others elide them altogether. The second research question focuses on doctor-patient interaction. Trust is often said to be central in medical encounters but this strikes us as too vague. The success of doctor-patient relations in part depends on adopting the most appropriate of the three attitudes we delineate. We argue that reliance is the appropriate attitude for most medical encounters. When circumstances do require trust, the distinction between specific trust and general trust is crucial. We describe medical encounters requiring specific trust. General trust is less often required in medicine; but it is appropriate in some cases and, when called for, it is called for strongly.

Rheological evaluation of the physical properties of hyaluronic acid dermal fillers.

BACKGROUND: Hyaluronic acid (HA) gels are commonly injected into the skin to lift rhytides and to improve facial appearance. The different processes used in their manufacture and formulation yield products with unique physical characteristics that play an important role in predicting their clinical performance. OBJECTIVE: The following rheologic evaluation was performed to objectively measure the physical characteristics of HA dermal filler products derived from similar bacterial sources and containing the same butanediol diglycidyl ether cross-linker, but formulated using different manufacturing techniques. The objective of this study was to evaluate the physical characteristics of two distinct families of HA products, thereby providing clinicians with a greater understanding of these products' attributes and the ability to optimize their use in the treatment of patients seeking facial rejuvenation. MATERIALS AND METHODS: The physical properties of commercially-available dermal fillers containing HA were evaluated using rheologic testing methods under clinically-relevant conditions. Additionally, light microscopy was used to assess the particulate nature of each product. RESULTS: The gels tested demonstrated a broad range of elasticity, firmness and viscosity. Light microscopy confirmed the particulate nature of each product and revealed HA particles of varying size and distribution. CONCLUSION: This rheologic evaluation demonstrates that differences exist among the HA products tested including gel elasticity, viscosity, and the range and distribution of gel particle sizes. Understanding the distinct physical characteristics of different HA dermal fillers and how these characteristics may predict their clinical behavior can assist clinicians in achieving the desired results in patients seeking facial rejuvenation.