Baseline characteristics and treatment preferences of oral surgery patients.

PURPOSE: Patient preferences for treatment choices may depend on patient characteristics. Using standard gamble (SG) and willingness to pay (WTP), this study compares preferences for treatment of mandibular fracture among patients in a low-income urban area. PATIENTS AND METHODS: Surveys of African-American and Hispanic adults receiving treatment at King/Drew Medical Center for either mandibular fracture (n = 98) or third molar removal (n = 105) were used to investigate differences in patient characteristics across treatment groups (third molar vs fracture) and treatment preference (wiring vs surgery). RESULTS: The fracture patients were willing to pay more to restore function without scarring or nerve damage than were the third molar patients. Patients who chose surgery were willing to accept a greater risk of possible nerve damage or scarring than those who chose wiring. Among 15 potential predictors of SG and WTP studied in 4 subgroups defined by actual treatment and treatment preference, significant predictors varied, with associations for education and clinical experience for SG and associations with income and psychosocial predictors for WTP. CONCLUSIONS: SG and WTP capture different domains of health values in patients. There is considerable heterogeneity in relationships among patient characteristics and patient preferences across subgroups defined by actual treatment and treatment preferences.     

Investigation of central visual fields in patients with age-related macular changes

The effect of early macular pigmentary and drusen changes on the central visual field was investigated in elderly patients with normal visual acuities. Visual field measurements were taken with the Humphrey Field Analyser using its 24-2 and 10-2 full threshold programs. No significant differences were found between two patients groups, one with and one without the macular changes. We conclude that fine pigmentary changes and hard drusen do not cause changes in visual functioning and can be accepted as normal age-related changes.     

Refractive errors induced by displacement of intraocular lenses within the pseudophakic eye

Simple methods were developed to estimate refractive errors when intraocular lenses are not fitted optimally within pseudophakic eyes. The accuracy of these methods was determined by comparing results obtained with them to results obtained by raytracing through a model eye. Accuracy was good for longitudinal displacement and tilting, and reasonable for transverse displacement. Refractive errors are related linearly to the magnitude of the longitudinal displacement, and are related to the square of the magnitude of tilt or transverse displacement. The refractive error upon transverse displacement is quadratically dependent upon lens shape.     

Transmitter, ion channel and receptor properties of pheochromocytoma (PC12) cells: a model for neurotoxicological studies.

The increased desire to use in vitro techniques in neurotoxicology has resulted in the search for clonal cell lines which may be useful for studying disruption by neurotoxicants of various aspects of neuronal physiology and biochemistry. One such cell line is the PC12 cell, a clonal cell line derived from a pheochromocytoma of the rat adrenal medulla. When cultured under normal conditions, PC12 cells resemble adrenal chromaffin cells in morphology, physiology and biochemistry. However, when cultured in the presence of nerve growth factor (NGF) or several other compounds, PC12 cells differentiate to resemble sympathetic neurons morphologically and functionally. Differentiation and the resultant physiological and biochemical changes are some of the most attractive and useful features of this cell line. PC12 cells release, depending on the conditions, dopamine, norepinephrine and acetylcholine and contain Na, K and Ca channels and other membrane receptors, including receptors coupled to G-proteins. Moreover, the relative proportion of various subtypes of Ca channels changes during differentiation. Thus, PC12 cells provide an excellent model for studying chemical disruption of processes associated with neuronal differentiation, synthesis, storage and release of neurotransmitters, function and regulation of ion channels and interactions of compounds with membrane bound receptors. The ability of PC12 cells to differentiate in response to NGF and other compounds allows for selective expression of certain channels and proteins and for comparisons of responses in undifferentiated and differentiated cells. The prominent neurotoxicant methylmercury causes potent reductions in uptake of 45Ca and binding of ligands associated with various subpopulations of Ca channels in the PC12 cells, as well as currents carried through putative Ca channels.