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Biomedical subjects

A R Simons

Publications and source records attributed to A R Simons.

4 recordsLinked to original sources
PubMed1986

Epidemiologic programs for computers and calculators. Simple algorithms for the representation of deterministic and stochastic versions of the Reed-Frost epidemic model using a programmable calculator.

Two programs are described for the emulation of the dynamics of Reed-Frost progressive epidemics in a handheld programmable calculator (HP-41C series). The programs provide a complete record of cases, susceptibles, and immunes at each epidemic period using either the deterministic formulation or the trough analogue of the mechanical model for the stochastic version. Both programs can compute epidemics that include a constant rate of influx or outflux of susceptibles and single or double infectivity time periods.

Computers↗
PubMed1984

Calibration of prestained protein molecular weight standards for use in the "Western" or enzyme-linked immunoelectrotransfer blot techniques.

Prestained protein molecular weight standards allow easy, direct visual location of electrophoretically transblotted lanes on nitrocellulose. They also provide a simple and accurate means for calibrating the molecular weights of resolved bands. Commercial prestained protein molecular weight standards, however, appear to have significantly different molecular weights from the original unstained proteins. We describe a calibration of these prestained molecular weight standards.

Collodion↗
PubMed1984

Immunofluorescent staining of Treponema in tissues fixed with formalin.

Immunofluorescent examination of formalin-fixed tissue for Treponema pallidum has generally been unsatisfactory because of nonspecific background fluorescence and poor contrast. We examined the process of treating deparaffinized formalin-fixed tissue sections with 1% ammonium hydroxide (NH4OH) to improve fluorescent staining. Treponema pallidum- and Treponema pertenue-infected rabbit testes or human tissue biopsy specimens fixed in 10% buffered formalin and embedded in paraffin were examined. Sections were cut one week to five years after embedment. Tissues were then stained with fluorescein- or rhodamine-labeled human anti- T pallidum globulin for 30 minutes at 37 degrees C. Treponemes were consistently stained and background staining was generally reduced after NH4OH treatment in both fresh and stored tissue. Cutting sections at a thickness of approximately 2 micron was critical to achieve optimal fluorescence.

Ammonium Hydroxide↗