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Biomedical subjects

P G Rasmussen

Publications and source records attributed to P G Rasmussen.

13 recordsLinked to original sources
PubMed1979

Aeromedical implications of the X-Chrom lens for improving color vision deficiencies.

A red contact lens (X-Chrom lens) worn on the nondominant eye by 12 color-defective subjects caused significant improvements on the Dvorine, Ishihara, and Hardy-Rand-Rittler pseudo-isochromatic color plate tests. Color vision scores on the Farnsworth Lantern, Color Threshold Tester, and Aviation Signal Light Gun were not improved. Minimal changes were found on the Farnsworth D-15 test, aeronautical chart color identification task, visual acuity, phoria, and stereoscopic depth perception. Control and color-defective subjects perceived a change in the path of a pendulum (Pulfrich test) when viewing through the X-Chrom lens or a monocular red filter. The X-Chrom lens may require extended wearing before its optimum effect becomes apparent.

Adult↗
PubMed1977

[Not Available].

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Denmark↗
PubMed1976

Congenital osteogenesis imperfecta in Charollais cattle.

An outbreak of an apparently new hereditary bone disease--congenital osteogenesis imperfecta--in six newborn half-sib Charollais calves is described. In many respects the clinical, pathological, radiological and genetical findings resemble the congenital osteogenesis imperfecta seen in man and sheep.

Animals↗
PubMed1976

Readability of approach charts as a function of visual acuity, luminance, and printing format.

This study determined the ability of 12 presbyopic subjects to read numerals from aeronautical approach procedure charts. The readability of chart numerals was determined for 15 size and contrast combinations as a function of near visual acuity (equivalent 20/20, 20/40, and 20/60) and chart brightness (100 and 1.0 ft L). Test subjects were evaluated at the normal near-visual-acuity level (20/20) and the minal near-visual-acuity levels (20/40) for Classes I and II and 20/60 for Class III) as specified in the FAA's Guide for Aviation Medical Examiners. The results indicated that subjects with 20/20 near visual acuity could read all chart numerals under bright and dim luminance conditions. Subjects with 20/40 and 20/60 levels of near visual acuity experienced reading difficulty under bright conditions and increased difficulty under dim luminance.

Aerospace Medicine↗
PubMed1975

Multiple epiphyseal dysplasia. 2. Morphological and histochemical investigation of cartilage matrix, particularly in the pre-calcification stage.

The cartilage of epiphysis and cuboid bones from three Beagle puppies bred from parents with a constant heredity of multiple epiphyseal dysplasia, was examined macroscopically, histomorphologically and histochemically. The puppies were euthanized at the age of one week, three weeks and five weeks, respectively. The investigation showed the foci of the disease develop in a broad subarticular zone where normally strong three-dimensional growth of the cartilage takes place. The first signs of the disease appeared about the time of birth and new foci reached a climax when the puppies were about three weeks old. Histomorphological and histochemical examination of the cartilage showed that the disease developed in a sequence of confluent stages. In the initial stage, there was an accumulation of abnormal cartilage matrix in the chondrocyte and/or chondrocyte lacunae. The abnormal substance consisted apparently of concentrated or free chondroitin sulphates not bound to protein. Then followed a second stage of liquefaction and coalescence of the abnormal cartilage matrix which formed cysts of different sizes, some of them visible macroscopically. In the third stage of calcification of the cyst content and surrounding abnormal cartilage, it was found that the calcium was deposited in grains bound to chondroitin sulphates. The results of the present study of the pre-calcification stage of the disease in Beagle dogs seem to be comparable with or equivalent to the results of the study of the post-natal stage of the disease in children and may explain something of the prenatal pathogenesis in children.

Age Factors↗