A clinical pilot study of the time-dependent composition of tooth bleaching systems.

This pilot study was undertaken to determine the compositional changes in tooth bleaching materials as a function of time in vivo. Ten patients were recruited and two bleaching systems were used - one a paste and the other a gel. Each material was placed in a custom bleaching tray and worn by each patient for each of four times - 15, 30, 60 and 120 min. The material was collected and chemically analysed for water by Karl Fischer titration and titrated for carbamide peroxide by the US Pharmacopoeia method. The paste material contained 18.66% water as supplied, and after 2 h this rose to between 28.6 and 64.4%. The gel material contained 2.85% water as supplied, and after 2 h this was diluted to between 28.5 and 73.4%. There was considerable difference in saliva uptake by the custom tray between patients. Most water uptake usually occurred within the first 30 min. Peroxide concentrations decreased in an approximately linear manner with time. There was a significant difference between the materials from baseline to 30 min and thereafter (P < 0.0009). This pilot study is an effective technique for chemical evaluation of bleaching materials. The effect of saliva is an important factor to consider, and is one that has hitherto not always been appropriately emphasized.

Polarized Emissivity and Kirchhoff's law.

An expression for the polarized emissivity of a material is obtained with the Stokes vector-Mueller matrix polarization formalism. The result obtained is that thermally emitted radiance might have a circular polarization component. In addition, the emissivity depends only on the reflectance matrix.

Uveitis and central nervous system vasculitis.

Vasculitis confined to the central nervous system (CNS) is a rare disease usually characterized by headache and focal neurologic symptoms. Patients with primary vasculitis of the CNS may have symptoms and laboratory findings of systemic disease such as fatigue and elevated erythrocyte sedimentation rate, but by definition, focal inflammation should not be present outside the CNS. We describe 3 patients with uveitis in association with this diagnosis. The recognition of this association adds to the complex differential diagnosis of uveitis in association with CNS disease, and indicates that "isolated" angiitis of the CNS may display clinical features outside the brain and spinal cord.

Comparison of methods for immobilization to carboxymethyl dextran sensor surfaces by analysis of the specific activity of monoclonal antibodies.

The authors have recently described the development of a carboxymethyl dextran-based sensor surface for biospecific interaction analysis by surface plasmon resonance. Ligands are immobilized via primary amine groups after activation of the carboxymethyl groups on the sensor surface with a mixture of N-hydroxysuccinimide and N-ethyl-N'-(dimethylaminopropyl) carbodiimide. Methods have now been developed for efficient immobilization via thiol/disulfide exchange, aldehyde coupling and biotin-avidin coupling. The specific activity of monoclonal antibodies immobilized by the four different methods was investigated by altering the immobilization conditions, e.g., activation time, protein concentration, ionic strength and the degree of modification, etc. Investigations have also been made concerning possible differences in the specific activity for antibodies immobilized using optimized conditions with respect to the four different chemistries. These studies show that, with the flexible carboxymethyl dextran matrix used here, the immobilization methods give rise to only minor differences in specific activity. Thus, with this solid support, a 'site directed' immobilization strategy for monoclonal antibodies has no advantage. In general the specific activity for optimized systems was approximately 75% for the binding of beta 2 mu-globulin to an immobilized monoclonal antibody directed against beta 2 mu-globulin. Reduced specific activities of immobilized antibodies induced by variation of the coupling conditions could be attributed to the deterioration of the active site of the antibody.

Immobilization of proteins to a carboxymethyldextran-modified gold surface for biospecific interaction analysis in surface plasmon resonance sensors.

A method for fast and simple covalent immobilization of proteins to a carboxymethyldextran-modified gold surface intended for surface plasmon resonance sensors is described. The method utilizes the formation of N-hydroxysuccinimide esters from a fraction of the carboxyl groups of the carboxymethyldextran matrix via reaction with N-hydroxysuccinimide and N-ethyl-N'-(dimethylaminopropyl) carbodiimide hydrochloride in water. In a second step the protein is passed over the surface in a solution of low ionic strength with a pH value below the isoelectric point of the protein. The protein is thereby concentrated in the matrix by electrostatic attraction forces and a simultaneous reaction with the active esters takes place. In a final step, the remaining active esters are transformed into amides via reaction with ethanolamine. This sequence is performed automatically in a system comprising an integrated microfluidic cartridge and an autosampler. Typical reaction times of less than 30 min are required for the immobilization of proteins at surface concentrations in the region of 70 fmol mm-2. Parameters such as protein concentration, protein solution ionic strength, pH, reaction times, and reagent concentration can be varied in order to control the immobilized amount of ligand. The biospecific interaction of the immobilized ligand with its biological counterpart is illustrated by the effects on the interaction of immunoglobulins with immobilized Staphylococcus aureus protein A for various amounts of protein A.

Integration of international and transcultural content in nursing curricula: a process for change.

A brief review of education and nursing literature indicates that it is essential to help students develop a global perspective as they prepare to practice nursing in a world of increasingly interdependent nations and people. The process currently being implemented to integrate international and transcultural content in the undergraduate nursing curriculum at a Midwestern state university is described in this article. Assessment of the school indicated that the student population and faculty are characterized by a high degree of radical-ethnic homogeneity. Assessment also included the mapping of content in all required courses in the undergraduate curriculum in the following areas: cultural differences, health care delivery systems in other countries, nursing in other countries, and international health organizations and issues. Recommendations were then made regarding content in required courses, continuation of elective courses, and informal educational strategies. Examples of these are described, as well as the resultant changes. Some of the changes described include content added and educational strategies used to integrate transcultural and international health content in required courses. Elective courses, taught both on-campus and abroad, are briefly described. Evaluation is an ongoing part of overall program evaluation. Highest priority for future planning is currently being placed on development of a semester study-abroad program and increasing cultural diversity in all students' educational experiences.