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Biomedical subjects

J P Miles

Publications and source records attributed to J P Miles.

4 recordsLinked to original sources
PubMed1990

Adult expression of the Drosophila Lsp-2 gene.

Previous work has demonstrated expression of the larval serum protein-2 gene, Lsp-2, uniquely during the late larval and pupal stages of development in Drosophila melanogaster. Here we report that the LSP-2 polypeptide accumulates in the hemolymph throughout adult life as well. Western blot analysis using an LSP-2 antiserum reveals notable differences in the molecular weight of the larval and adult polypeptides. Lsp-2 transcription results in a unique mRNA of 2.3 kb, exhibiting the same 5' end in both larvae and adults. However, adult Lsp-2 mRNa is only expressed at 1% of the high level detectable in late third-instar larvae. Whereas Lsp-2 mRNA accumulates uniformly in all fat body cells of third-instar larvae, over 80% of the adult Lsp-2 transcript is expressed in the adipose tissue of the head. These results suggest a differential regulation for expression of the Drosophila Lsp-2 gene in adults and larvae.

Animals↗
PubMed1982

Analytical methods used by industry for lead in infant formula.

The lead content of liquid infant products has been a prime focus of regulatory, industrial, and private analysts for some time. The principal source of Pb in these products is the solder used in 3-piece can manufacture. Voluntary surveys by the Infant Formula Council member companies from 1978 to present show that even low 1978 levels have been significantly reduced. Two procedures, anodic stripping voltammetry and electrothermal atomization (graphite furnace and carbon rod) atomic absorption spectrophotometry, are currently used by industry analysts. The results of 2 comparison studies provide a means of estimating the reliability of the procedures. Results of thousands of trace Pb determinations have demonstrated that steps to ensure the validity of results must be integrated into the entire analytical scheme. Quality control practices are described. Control of the laboratory environment is essential for ultimate sensitivity, and the design and performance of a trace metals analysis facility are discussed.

Electrochemistry↗
PubMed1982

Infant formula physical stability.

The physical nature of liquid infant formula products is characterized in terms of emulsion, suspension, and solution processes. Such mixtures inevitably undergo phase separation. A variety of physical and chemical phenomena govern the gradual changes in the appearance of these products. The consequent loss of physical elegance is primarily a question of consumer acceptance. Only in the most extreme cases do the physical characteristics deteriorate to the point that swallowing and digestion are affected. Recently, both public and regulatory attention has been focused on the physical characteristics of liquid infant formula products. Formula appearance is the product aspect most readily evaluated by the consumer. The design and manufacture of products that will have consistent appearance over extended periods is a difficult technical problem. This presentation summarizes the phenomena responsible for changes in the physical characteristics of liquid infant formula products. Product defects are discussed and methods for product evaluation are described. Representative data on the effect of storage on product physical elegance also are presented.

Dietary Carbohydrates↗