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Biomedical subjects

D W Anderson

Publications and source records attributed to D W Anderson.

At least 145 records · Page 8Linked to original sources
PubMed1978

A study of the dose to the thyroid and the eye in computed tomography of the brain.

Thermoluminescent dosimeters were used to estimate the dose to the thyroid and the eye for routine clinical computed tomography of the brain using an EMI CT5005 scanner (20-sec data acquisition mode, bolus covering the head). The data can be summarized by the linear relations Dt = (7.5 +/- 0.8)N millirads (8 less than or equal to N less than or equal to 18) and De = (39 +/- 5)N + (1400 +/- 200)n millirads (8 less than or equal to N less than or equal to 20, 0 less than or equal to n less than or equal to 6) where Dt is the dose to the tissue anterior to the thyroid, De is the dose to the anterior tissue of the eyelid, N is the total number of CT cuts, and n is the number of cuts in which the globe of the eye is imaged.

Eye↗
PubMed1977

Particle distribution of human serum high density lipoproteins.

Density gradient ultracentrifugation of human serum high density lipoproteins (HDL) from both normolipemic males and females results in a distribution of HDL concentration versus subfraction hydrated density which has three maxima. Gradient gel electrophoresis of total HDL is characterized by three banding maxima, the positions of which suggest the presence of three particle size ranges: I. 10.8-12.0 nm, II. 9.7-10.7 nm, and III. 8.5-9.6 nm. Gradient gel electrophoresis of density gradient subfractions established an inverse relationship between particle size and particle hydrated density which was corroborated by electron microscopy and analytic ultracentrifugation. Comparison of male HDL from size ranges I, II, and III with female HDL from the same size ranges showed only small differences in the mean value of the peak F degrees 1.20 rate, size, molecular weight, protein weight percent, and weight protein/weight phospholipid. Major differences between males and females were seen in the relative amounts of HDL in density gradient subfractions 1-3 (size range I material) and 11-12 (size range III material); the percent total HDL in the group of subfractions 1-3 was greatly increased in female HDL while that of the group of subfractions 11-12 was increased in the male HDL. These studies indicate the presence of at least three major components in HDL instead of two (HDL2 and HDL3) and that peak F degrees 1.20 rate differences in HDL schlieren patterns between males and females are a function of the relative levels of these three components.

Centrifugation, Density Gradient↗
PubMed1976

Effects of guanidine hydrochloride on human plasma high density lipoproteins.

Denaturation of human plasma high density lipoproteins during ultracentrifugation in guanidine-HCl is characterized by: dissociation of apoA-I, in the range of 2-3 M guanidine-HCl, and dissociation of apoA-I and apoA-II in 5-6 M guanidine-HCl. Denaturation of high density lipoprotein species, during a sequence of timed exposure to guanidine-HCl followed first by removal of the denaturant by dialysis and then by ultracentrifugation, is characterized by:dissociation of lipid-poor apoA-I, which follows a time course similar to denaturation-related changes in reported spectroscopic parameters; and apparent formation of lipoprotein aggregation products depleted in apoA-I and relatively enriched in apoA-II. These studies indicate differential properties of the major apoproteins in stabilizing high density lipoprotein structure and characterize a mode of lipoprotein transformation and degradation which apparently results from apoprotein dissociation coupled with aggregation of denatured lipoprote species.

Adult↗
PubMed1976

Conversion from exposure to dose for megavoltage beams under 3 MeV.

An exact expression was developed for conversion from exposure in air to dose in some medium at the depth where the kerma equals the dose. This depth was estimated for 60Co beams in water using published data, and found to be 0-4 +/- 0-05 cm. An example of the use of the conversion relationship for a 60Co beam is given.

Cobalt Radioisotopes↗
PubMed1976

Central axis depth dose for a 2.5 MV Van de Graaff generator.

Central axis percentage depth dose values and isodose curves for the bremsstrahlung beam from a 2.5 MV Van de Graaff generator were measured with a water phantom at 100 cm target-to-surface distance. Tissue-air ratios were calculated from the central axis depth dose data. Use of the 2.5 MV percentage depth dose values are necessary for treatment planning since they are substantially larger than the values given in compilations for 2.0 MV beams.

Humans↗
PubMed1976

Rapid radioimmunoassay of total urinary estriol.

We describe a radioimmunoassay for total urinary estriol in pregnancy. A 25-mul aliquot of the urine specimen is acid hydrolyzed, neutralized, and diluted before assay. We use rabbit antisera against estriol-6-(O-carboxymethyl)oxime/bovine serum albumin and ammonium sulfate precipitation at room temperature. Results are unaffected by glucose or methenamine mandelate, a urinary tract antiseptic. Using semi-automatic pipetting equipment, one laboratory technologist can complete 50 assays within 8 h. This technique is both reliable and convenient and should decrease the expense of routine estriol assays.

Colorimetry↗
PubMed1975

Brown pelicans: improved reproduction off the southern California coast.

Although still about 30 percent too low for population stability, productivity of California brown pelicans at their two northern colonies has improved significantly since 1971. Numbers of adults breeding probably reflect food supplies and recruitment from more successful colonies to the south, but improving fledging rates (up to 0.9 young per nest in 1974) reflect better egg survival and improving eggshell condition, with declining DDE contamination in anchovies, their major food source.

Animals↗