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Biomedical subjects

J R Grace

Publications and source records attributed to J R Grace.

4 recordsLinked to original sources
PubMed1991

High density cultivation of BSK cells on sintered alumina ceramic foam support.

A perfusion system which utilizes a porous ceramic core has been tested for the cultivation of transformed BHK cells which produce human transferrin. A design is presented in which cells are immobilized within the porous ceramic particle and are fed by continuous perfusion of batch liquid medium. It was found that more than 5 x 10(9) BHK cells could be supported within the 40 mL ceramic matrix, a ten-fold increase in cell density per unit surface area over the standard roller bottle cultures or a five-fold increase in volumetric cell density over suspension cultures. The cell specific productivity of human transferrin was similar to that observed in suspension culture. The system offer the advantages of significant reduction in serum requirements and the potential for scale-up.

Aluminum Oxide↗
PubMed1991

A hierarchical coding system for occupational exposure.

A 10-digit hierarchical method for coding occupationally encountered chemicals offering significant advantages over existing chemical coding systems has been developed and tested. With this unique system, substances are categorized and coded according to their composition and physical natures. Consequently, compounds of similar structure may be distinguished, and classes of similar compounds (for example, all halogenated organic compounds, all inorganic sulfates) can be readily retrieved. This novel coding system was developed to assist primarily in the identification of potential carcinogens in occupational studies using job exposure matrices. However, the system has wider applications as it can be employed by industry to facilitate data management and monitoring programs in the workplace.

Carcinogens↗
PubMed1989

A generalized model for the prediction of lead body burdens.

A compartmental model of a typical 70-kg male for lead intake, distribution, and transport has been developed based on previous pharmacokinetic models and experimental results for lead in the human body. A set of first-order, linear ordinary differential equations with constant coefficients is solved to predict lead levels in blood, bone, and other compartments as a function of time resulting from inputs from air and/or ingestion. The model has been shown to be in excellent agreement with the measurements of blood lead for a controlled study by M. B. Rabinowitz et al. (1976, J. Clin. Invest., 58, 260-270). Favorable agreement was also found with blood and urine results reported by T. B. Griffin et al. (1975, "Lead," pp. 221-240) providing that an allowance was made for an unmeasured input of lead, originating from smoking, snacks, etc. The predictions of the newly formulated model are compared with those of the established Bernard model (S. F. Bernard, 1977, Health Phys., 32, 44-46). Predictions of blood lead concentration for short periods (on the order of months) are fitted better by the new model, while both models predict similar behavior over the longer term (on the order of 5 years and greater).

Adult↗