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Biomedical subjects

T L Lewis

Publications and source records attributed to T L Lewis.

14 recordsLinked to original sources
PubMed1992

The development of the temporal and nasal visual fields during infancy.

We used static perimetry to measure the development of the monocular visual field during infancy. Infants from birth to 6 months of age, and adults, were shown a 3 or 6 degrees flashing light at various locations between 15 and 120 degrees in the temporal and nasal visual fields. We assumed that subjects could see a light if they moved their eyes toward it more often than they looked in the same direction on blank control trials. For both the 3 and 6 degrees lights, the visual field expanded with age from the center out, and development in the nasal visual field lagged behind development in the temporal visual field. Possible reasons for these findings are discussed.

Adult↗
PubMed1992

Vision in the "good" eye of children treated for unilateral congenital cataract.

PURPOSE: The authors examined linear acuity and contrast sensitivity in the "good" (fellow) eye of children treated for unilateral congenital cataract to determine (1) whether there were subtle deficits like those described for the good eye of patients with strabismic amblyopia and (2) whether any deficits were related to the degree to which the good eye had been patched. METHODS: The authors tested patients treated for unilateral congenital cataract who had a well-documented history of patching. The good eye was physically normal with minimal refractive error. The measures were linear acuity at far (n = 15) and contrast sensitivity (n = 9). RESULTS: Compared with age-matched control subjects, the good eyes of patients had subtle deficits in linear acuity and in contrast sensitivity at high spatial frequencies. These deficits occurred even in eyes that had received minimal patching, and their severity was not related systematically to the duration of patching, which varied widely across the group. CONCLUSION: The visual sensitivity of the good eye of children treated for unilateral congenital cataract is, on average, slightly reduced, even in cases of minimal patching. Consequently, any deficits discovered after aggressive patching may not have been caused by occlusion amblyopia.

Adolescent↗
PubMed1979

Microbiology subsystem of a total, dedicated laboratory computer system.

The computer system used by the Microbiology Service of the Clinical Pathology Department, Clinical Center, National Institutes of Health is discussed. This microbiology subsystem is a part of a dedicated on-line laboratory computer system used by the entire department. The laboratory computer is connected on-line to a hospital computer which provides patient admission, transfer, and discharge data. Mark sense worksheets and cathode ray tube terminals are used for result entry and correction. Cumulative patient reports are printed. Results for both active and completed accessions can be easily retrieved on cathode ray terminals in the laboratory. All laboratory data are archived on magnetic tape from which a research data base and microfiched laboratory records are generated. The manner in which the system is integrated in the routine operation of the microbiology laboratory is emphasized. In addition, some of the costs, benefits, liabilities, and pitfalls associated with the introduction of the computer in the laboratory are reviewed. Finally, we have presented our concept of some of the future enhancements to our present system and some of the directions in which any future microbiology system might develop.

Computers↗
PubMed1979

Peripheral discrimination by three-month-old infants.

3-month-old infants made 2 types of discrimination with their peripheral vision. They discriminated between grossly different figures placed as far out as 30 degrees toward the periphery, and they discriminated between more subtly different figures, which differed only in the shape of their internal elements, out to 10 degrees. The results imply that infants can readily process stimuli with peripheral vision.

Discrimination Learning↗
PubMed1977

Pancreatectomy in a teleost fish, Anguilla rostrata (American eel).

A technique for pancreatectomy was described for the American eel. In this fish, the operation was not followed by the typical signs of diabetes mellitus. Histodensitometric determination of liver glycogen showed no major differences between operated controls and pancreatectomized eels. The absence of a specific hyperglycemia, previously reported with the hexokinase method, was confirmed with the glucose oxidase technique; however, the more specific hexokinase method gave consistently lower values. Breakdown of adipose tissue and hyperlipemia were absent.

Animals↗
PubMed1975

Ascorbic acid for the common cold. A prophylactic and therapeutic trial.

Three hundred eleven employees of the National Institutes of Health volunteered to take 1 gm of ascorbic acid or lactose placebo in capsules three times a day for nine months. At the onset of a cold, the volunteers were given an additional 3 gm daily of either a placebo or ascorbic acid. One hundred ninety volunteers completed the study. Dropouts were defined as those who missed at least one month of drug ingestion. They represented 44% of the placebo group and 34% of those taking ascorbic acid. Analysis of these data showed that ascorbic acid had at best only a minor influence on the duration and severity of colds, and that the effects demonstrated might be explained equally well by a break in the double blind.

Adult↗
PubMed1975

Health-care workers positive for hepatitis B surface antigen. Are their contacts at risk?

To assess the hepatitis risk to patients exposed to HBs AG-positive health-care workers, 228 contacts were followed prospectively for six to nine months. Health workers included two physicians with chronic hepatitis, a chronic asymptomatic carrier nurse, a food handler with acute HBs Ag-positive hepatitis and a physician who was HBs Ag-positive for 25 days before the onset of acute hepatitis. Controls (167) consisted of identically followed patients who had not been exposed to an HBs Ag-positive health worker. No exposed or control patient acquired clinical hepatitis or HBs Ag. Isolated elevations in serum glutamic pyruvic transaminase occurred equally in both groups and did not correlate with serologic evidence for hepatitis B infection. One exposed patient demonstrated antibody seroconversion (anti-HBs), as did two of the controls. These data do not demonstrate hepatitis B transmission from HBs Ag-positive health workers to their patients. Restriction of such carriers is not warranted at present.

Acute Disease↗