Biomedical subjects

B Fortune

Publications and source records attributed to B Fortune.

6 recordsLinked to original sources

PubMed1999

Multifocal electroretinogram delays reveal local retinal dysfunction in early diabetic retinopathy.

PURPOSE: To identify local retinal abnormalities in diabetic patients with and without retinopathy, by using the multifocal electroretinogram (M-ERG). METHODS: Electroretinograms were recorded at 103 discrete retinal locations in each eye of eight persons with nonproliferative diabetic retinopathy (NPDR) and eight diabetic persons without retinopathy, using VERIS (EDI, San Mateo, CA). The amplitude and implicit time of each local (first-order) retinal response were derived and compared with normal values obtained from 16 age-matched, nondiabetic subjects. Maps of local response amplitude and implicit time were compared with fundus photographs taken at the time of testing. RESULTS: In eyes with NPDR, the implicit times of responses from retinal sites manifesting clinical pathologic fundus lesions (e.g., microaneurysms and focal edema), were markedly delayed (e.g., up to 7 msec from normal). Responses from adjacent retinal sites that were more normal in clinical appearance were also delayed, but to a lesser extent (e.g., 2-5 msec). Smaller, yet significant local response delays were also found in eyes without retinopathy. By contrast, local response amplitudes bore no consistent relationship to fundus abnormalities in eyes with retinopathy, and amplitudes were typically normal in eyes without retinopathy. CONCLUSIONS: The M-ERG reveals local retinal dysfunction in diabetic eyes even before retinopathy. The magnitude of delay of local ERG implicit time reflects the degree of local clinical abnormality in eyes with retinopathy. Local response delays found in some eyes without retinopathy suggest that the M-ERG detects subclinical local retinal dysfunction in diabetes. Analysis of M-ERG implicit time, independent of amplitude, improves the sensitivity of detection of local retinal dysfunction in diabetes.

Adult↗

PubMed1997

Acute effects of blood glucose on chromatic visually evoked potentials in persons with diabetes and in normal persons.

PURPOSE: To determine whether specific chromatic pathways are selectively affected by short-term variations in blood glucose levels in observers with and without diabetes. METHODS: Ten subjects with diabetes, all with type 1 diabetes and no retinopathy, and eight age-similar normal subjects were tested. Cortical visually evoked potentials (VEPs) in response to stimuli designed to selectively activate the short-wavelength-sensitive (S) or long- and middle-wavelength-sensitive (LM) chromatic (isoluminant) pathways or the achromatic pathway were recorded over a period of several hours. Capillary blood glucose also was measured repeatedly over the same period. The relation between VEP latency and blood glucose was determined. RESULTS: The S-pathway VEP latency was correlated significantly with blood glucose in a slight majority (6/10) of persons with diabetes; S-pathway latency was longer at higher blood glucose levels. This association between S-pathway latency and blood glucose was not dependent on the pattern of blood glucose variation over time (i.e., significant correlations between blood glucose and latency were observed in persons for whom blood glucose increased, decreased, or rose and then fell over time). No dependence on blood glucose was observed for LM- or achromatic-pathway VEP latency in subjects with diabetes. CONCLUSIONS: Acute variations in blood glucose of subjects with diabetes over hours selectively affect the function of the short-wavelength-sensitive chromatic pathway. The findings are discussed within the context of known mechanisms by which elevated glucose affects cellular metabolism with a time course consistent with the transient nature of the effect observed.

Adult↗

PubMed1994

Smooth pursuit eye movements with imaginary targets defined by extrafoveal cues.

Initiation of smooth pursuit eye movements was studied using imaginary targets defined by pairs of small spots ("cues") moving together in step-ramp motion. The arrangement of cues and imaginary target were either "two-sided"--cues far apart and imaginary target midway between, or "one-sided"--cues 4 deg apart and imaginary target to one side of the cue pair. (1) Pursuit of two-sided stimuli was much better than pursuit of one-sided stimuli and was often as good as pursuit of a real foveal target. (2) Experiments with various cue configurations suggest an attribute required for vigorous pursuit: "foveal enclosure". Configuration information is available to the pursuit system immediately after the onset of motion. (3) Pursuit of imaginary targets is markedly degraded by a background; the effect is strongest for a background at the fovea and weaker for an eccentric background, including one at the cue location.

Cues↗

PubMedDate not supplied

Hitting the moving target of program choice.

The changes in what 2,927 people wanted and got for programs in 1988 were compared with what 3,934 people wanted and received in 1996 in Wyoming and South Dakota. As recommendations change, they present a "moving target" for these service-delivery systems. In 1988, 51% of those served in Wyoming and 62% of those served in South Dakota were in their preferred setting. By 1996, the Wyoming percentage rose to 84%, whereas South Dakota's percentage moved up to 72%. These increases enhanced other "quality of life" measures. Comparing 1996 with 1988, for example, fewer individuals in both states reported no social or leisure activities. Fewer reported the lack of transportation as a barrier and fewer reported having no one to accompany them to activities. More individuals reported family contact, family visits, and identified a hobby or personal leisure activity. The 8-year expansion of services and supports had increased positive social activities.

Adult↗

PubMedDate not supplied

Advisory committees for agencies that provide services for children with special health-care needs.

The Children's Special Health Care Services Advisory Committee is an advisory group that includes stakeholders in the delivery of care for children with special health-care needs. An emphasis has purposely been placed on consumer participation to ensure adequate voice and balance with other provider, legislative, and bureaucratic interests. The Advisory Committee has assumed an aggressive and complete role in reviewing and recommending every aspect of the program. As a result of this active co-ownership, the program has repeatedly survived threats of serious budget cuts and reductions to its base. Agreement between providers and consumers on values, structure, and operational needs has been reached. A win-win approach has been possible, not only in the planning and growth of the program but also in the policy arena, legislatively, and with the administration.

Child↗

PubMedDate not supplied

Ethics case study.

Explore the source record for details and available documents.

Confidentiality↗