Diagnostic quality of low resolution images for tele-woundcare

The use of digital wound images would allow remote consultation between patients, physicians, or other caregivers over the Internet. To evaluate the efficacy and validity of digital images for assessment of wounds, we compared the ability and reliability of surgeons to diagnose and make treatment suggestions using either digital or slide images of several types of wounds. Twenty-four wound images on 35-mm slides were selected for use in this study. Each slide image was digitized at 24-bit color with a resolution of 640 pixels horizontal by 425 pixels vertical, and stored as a JPEG file. Six physicians, of varying experience, examined the images, first in digital format and then later in the original slide form. Each observer assessed each wound for condition and possible treatment options by filling out a questionnaire using a series of yes/no questions. For all observers, there was an 87% agreement of answers between digital and slide images (p = 0.004). The agreement between the digital and slide images was also measured for each individual observer using a kappa coefficient. The agreement kappa correlated with the experience of the observer, with the kappa values ranging from greater than 0.8 (almost perfect agreement) for an experienced woundcare professional to just greater than 0.5 (moderate agreement) for a surgical intern. With this study, we have demonstrated the feasibility of distance wound consultation using digital images of a quality consistent with consumer-grade digital photography.

Active site of dopamine beta-hydroxylase. Comparison of enzyme derivatives containing four and eight copper atoms per tetramer using potentiometry and EPR spectroscopy

Potentiometric titrations, continuous wave EPR, and microwave power saturation measurements have been used to examine 8-Cu and 4-Cu forms of native dopamine beta-hydroxylase and its azide derivative. The formation curve for the binding of Cu2+ to the apoenzyme is best fit by assuming two independent binding sites per subunit, with pK' values of 8.90 and 7.35 at pH 5.0. On the other hand, only minor differences are observed in either continuous wave EPR spectra or power saturation behavior of the 8- and 4-Cu forms of the native enzyme or of its azide derivative. The intensity of the EPR spectra of all derivatives integrates to greater than 95% of the total copper, and the temperature dependence of P1/2 shows no evidence for any S = 1 state of the copper ions in the enzyme. These results suggest a lower limit of ca. 7 A for the separation between the two copper ions per subunit and thus rule out a type 3 site in the oxidized enzyme. The data are most consistent with Cu(II) sites consisting of two or three N (imidazole) and one or two O donor ligands in the coordination sphere. The similarity in EPR spectra and power saturation of 8- and 4-Cu derivatives suggests that the difference in Cu-binding constants may be due either to differences in the identity of an axial ligand or to solvation effects in the active site.

Bilateral electrodermal activity as a function of hemisphere-specific stimulation, hand preference, sex and familial handedness

The effects of unilateral stimulation on bilaterally recorded electrodermal activity are not well understood. Factors that may contribute to bilateral response differentiation under conditions of unilateral stimulation include preferred hand, sex and familial handedness. To assess the effects of these factors, 64 subjects were each assigned to one of four cells defined by sex and preferred hand. Each subject received a counterbalanced series of 31 slides depicting objects spatially and intended to activate the right hemisphere and 31 slides depicting objects spatially and intended to activate the left hemisphere. Each condition was followed by a blank slide. Results showed smaller mean nonspecific responses on the hand contralateral to the hemisphere for which stimulation was intended. This supports the hypothesis that a contralateral inhibitory process underlies electrodermal responsiveness. Further results showed that the effects of unilateral stimulation on bilaterally differentiated electrodermal activity are mediated by familial handedness and sex.

DESCRIPTORS

hemispheric processes, bilateral EDA, sex, familial handedness, preferred hand.