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D Thayer

Publications and source records attributed to D Thayer.

5 recordsLinked to original sources
PubMed2001

Indocyanine green angiography of the anterior segment in patients undergoing strabismus surgery.

BACKGROUND: Anterior segment imaging using fluorescein angiography is only suitable in lightly pigmented irides as the brown pigmentation of the iris masks fluorescein transmission. Indocyanine green (ICG) angiography has excellent penetration of pigment epithelium and, therefore, has potential application in detecting perfusion changes of dark irides after strabismus surgery. METHODS: A prospective study was conducted on patients older than 15 years undergoing strabismus surgery. A fundus camera was focused on the arteriolar tufts of the pupillary margin and 50 mg of ICG (concentration of 12.5 mg/ml) was given intravenously. Images were then obtained at 1 minute intervals of 5 minutes' duration. RESULTS: 45 patients with a mean age of 54.6 years and a mean follow up period of 8.6 weeks were studied. There were 23 patients in the primary surgery group, 11 in the secondary surgery group, and 11 in the staged group. Iris ICG angiograms were successfully performed in all patients. No persistent filling defect was detected in the primary and secondary horizontal recti surgery groups or in the secondary or staged vertical and combined vertical rectus groups 6-8 weeks postoperatively. 57% of both primary vertical and combined vertical and horizontal groups showed defects in the early postoperative phase. Only three cases demonstrated late perfusion defects in this series. CONCLUSION: ICG can detect iris perfusion changes in dark irides after strabismus surgery. Iris reperfusion was achieved in the majority of the cases.

Adolescent↗
PubMed1996

Occupational health data as a basis for process engineering changes: development of a safe work environment in the sodium azide industry.

The development of an occupational health system for a plant manufacturing sodium azide has had to confront biological and hygienic difficulties related to the nature of sodium azide. Sodium azide in pellet form is used as the nitrogen generant for automobile air bags; however, it is manufactured as a very fine powder making exposure control more difficult. Sodium azide is a rapidly active, vasodilatory hypotensive agent that causes headaches and drops in blood pressure. Occupational health assessment of the plant and its employees demonstrated the need for exposure control, based on inspection, interviews, health data, process and site review. Targeted studies demonstrated the nature and magnitude of health effect problems at this plant and the relationship to azide exposure. Engineering and hygiene changes were developed in response to the evidence of worker exposure demonstrated by the targeted studies. The occupational health surveillance system provided a monitor for temporal changes. Results appear to demonstrate over the period of the development of the program, the following changes: (1) reductions in evidence of subjective symptoms from azide exposure (health incident reports of headaches and other symptoms), (2) reductions in objective signs of effects from azide exposure (drops in cross-shift mean arterial blood pressures), and (3) reductions in measured levels of azide exposure. Future studies need to validate the evidence of exposure changes and to further identify additional sources of exposure. Interventions designed to reduce exposures need to be demonstrated to be effective and need to be monitored to demonstrate continuing effectiveness.

Azides↗
PubMed1977

A study of X chromosome linkage with field dependence and spatial visualization.

The purposes of this report are to describe a design for the study of X linkage, to illustrate its application using cognitive test scores, and to offer a linkage hypothesis suggested by these data. Sixty-seven three-son families were examined for two X chromosome marker variables--red-green color vision and Xg(a) blood groups--and given a battery of cognitive tests of field dependence and spatial visualization abilities. Evidence was found to suggest that brothers who are identical in Xg(a) phenotype are more similar to each other in extent of field dependence than brothers who are different in Xg(a) phenotype. This result is tentative because of the small number of informative cases and the many linkage associations examined. If cross-validated, such a finding would be consistent with the proposition that an X chromosome gene contributes to the field dependence cognitive style.

Blood Group Antigens↗