Biomedical subjects
Publications and source records attributed to J A Townsend.
An experimental data checker has been developed that reads, analyses, and cross-correlates experimental information copied and pasted from authors' manuscripts, which will be useful for authors, referees, editors and readers of papers reporting new molecular information, and which makes possible a quantification of the accuracy of journals' data.
Phase-feeding (PF; Treatment 2) was tested relative to an NRC regimen (Treatment 1) to evaluate the impact of PF on broilers during the finisher period (42 to 63 d). Two modified PF treatments were also tested during this experiment: Treatment 3 involved lowering the amino acid requirements predicted with PF linear regression equations by 10% (PF10), Treatment 4 involved increasing the slope of the linear regression equations by 15% (PF15). Broilers fed Treatment 1 consumed a single diet throughout the experiment, whereas PF treatments were fed in a series of 11 diets in which feed was switched every other day, resulting in steadily decreasing lysine, SAA, and threonine levels. On Day 63, weight gain, feed intake, feed efficiency, and crude protein intake did not differ (P > 0.05) among birds fed PF treatments and Treatment 1. Digestible lysine and threonine intakes were increased (P < 0.05) for Treatment 1 relative to the PF treatments, and digestible SAA intake for the NRC treatment was increased (P < 0.05) relative to the PF10 and PF15 treatments. Compared to Treatment 1, no differences (P > 0.05) in percentage breast, wing, leg, or abdominal fat were observed when birds were fed PF, PF10, or PF15 diets. These results indicate that PF supports maximum growth performance during an extended finisher period, even when lysine, SAA, and threonine levels are reduced every other day. Economic analysis indicated that PF regimens may lead to savings ($ per kg weight gain or breast meat).
BACKGROUND: The nutritional quality of soybeans (Glycine max) is compromised by a relative deficiency of methionine in the protein fraction of the seeds. To improve the nutritional quality, methionine-rich 2S albumin from the Brazil nut (Betholletia excelsa) has been introduced into transgenic soybeans. Since the Brazil nut is a known allergenic food, we assessed the allergenicity of the 2S albumin. METHODS: The ability of proteins in transgenic and non-transgenic soybeans, Brazil nuts, and purified 2S albumin to bind to IgE in serum from subjects allergic to Brazil nuts was determined by radioallergosorbent tests (4 subjects) and sodium dodecyl sulfate-polyacrylamide-gel electrophoresis (9 subjects) with immunoblotting and autoradiography. Three subjects also underwent skin-prick testing with extracts of soybean, transgenic soybean, and Brazil nut. RESULTS: On radioallergosorbent testing of pooled serum from four subjects allergic to Brazil nuts, protein extracts of transgenic soybean inhibited binding of IgE to Brazil-nut proteins. On immunoblotting, serum IgE from eight of nine subjects bound to purified 2S albumin from the Brazil nut and the transgenic soybean. On skin-prick testing, three subjects had positive reactions to extracts of Brazil nut and transgenic soybean and negative reactions to soybean extract. CONCLUSIONS: The 2S albumin is probably a major Brazil-nut allergen, and the transgenic soybeans analyzed in this study contain this protein. Our study show that an allergen from a food known to be allergenic can be transferred into another food by genetic engineering.
The 35S promoter of cauliflower mosaic virus and promoters from the nopaline synthase, 1' and 2' genes of Agrobacterium tumefaciens T-DNA were fused to the bacterial octopine synthase and chitinase gene coding regions. These chimaeric gene constructions were introduced into tobacco, sugarbeet and oilseed rape cells and their relative levels of expression measured by primer extension analysis of RNA isolated from pooled populations of stably transformed calli. In tobacco callus, the 35S promoter provided the highest levels of gene expression, followed by the 2', 1' and nopaline synthase promoters. While the ranking of these promoters is conserved in sugarbeet and oilseed rape callus, there is between-species variation in the relative strength of these promoters. In all three species, transcription initiation is conserved for each of the chimaeric gene constructions. Additional constructions in which the 5' untranslated leader of a petunia chlorophyll a/b binding protein gene is substituted for DNA downstream of the 35S transcription start site demonstrates that heterologous 5' leader sequences can be utilized to augment steady-state levels of reporter gene expression.
Cerebrotendinous xanthomatosis is a familial recessive disorder. Patients with the disorder present with tendon xanthomas, juvenile cataracts, dementia, and pyramidal and cerebellar abnormalities but have normal plasma cholesterol. High plasma cholestanol concentrations and abnormal bile acid metabolism are specific for this disease. The authors describe four patients with cerebrotendinous xanthomatosis and prominent psychiatric symptoms. In three of these patients appropriate diagnosis and treatment were delayed for years because the presence of cerebrotendinous xanthomatosis was not recognized. Early recognition of this potentially lethal disease is important because both the psychiatric and neurological symptoms respond to treatment with chenodeoxycholic acid.
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