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Biomedical subjects

J Hope

Publications and source records attributed to J Hope.

118 records · Page 7Linked to original sources

Absence of Chromosome Damage in the bone marrow of rats fed detergent actives for 90 days.

Four detergent actives, sodium lauryl sulphate, DOBS 055, Dobanol 25 sulphate LCU and Dobanol 25 sulphate HCB, were fed to rats in the diet for 90 days at the maximum tolerated dose, 1.13 percent active ingredient in each case. Sodium lauryl sulphate and DOBS 055 were also fed at half this concentration. Chromosome preparations were made from the bone marrow and scored for the presence of rearrangements, chromatid gaps and breaks and isochromatid gaps and breaks. The four detergent actives were found to have no effect on the chromosomes of rat bone marrow cells.

Bone Marrow↗

129/Ola mice carrying a null mutation in PrP that abolishes mRNA production are developmentally normal.

The neural membrane glycoprotein PrP is implicated in the pathogenesis of the transmissible spongiform encephalopathies; however, the normal function of PrP and its precise role in disease are not understood. Recently, gene targeting has been used to produce mice with neo/PrP fusion transcripts, but no detectable PrP protein in the brain (1). Here we report the use of a different targeting strategy, to produce inbred mice with a complete absence of both PrP protein and mRNA sequences. At 7 mo of age, these mice show no overt phenotypic abnormalities despite the normal high levels of expression of PrP during mouse development. The mice are being used in experiments designed to address the role of PrP in the pathogenesis of scrapie and the replication of infectivity.

Aging↗

An investigation of N-terminal pro-opiocortin peptides in the rat pituitary.

Extracts of neurointermediate lobe (NIL) and anterior lobe (AL) of the rat pituitary, and material released from perfused rat pars distalis (PD) and pars intermedia (PI) cells were gel chromatographed and monitored using three antisera, each recognizing different regions of the non-corticotropin (ACTH)-lipotropin (LPH) portion of pro-opiocortin (POC). Two peaks (termed N-POC I) which emerged close to the elution position of rat beta-LPH were detected. The first peak was reduced significantly in the PI. Two smaller N-POC fragments which eluted near beta-endorphin were detected only in extracts and secretions of intermediate lobe tissue. One peak cross-reacted in the gamma 3-melanotropin (MSH) assay (N-POC III) whereas the other peak possessed amino (N)-terminal N-POC immunoreactivity (N-POC II). The results demonstrated differences in the distribution and nature of N-POC peptides released and extracted from the PD and PI of the rat pituitary, and suggest that the enzymic processing of N-POC is different in the two pituitary lobes.

Animals↗

Mice and beef and brain diseases.

Can people contract neurodegenerative disease by eating beef products contaminated with bovine spongiform encephalopathy? Experiments with transgenic mice give cause to think that the answer may be 'no'.

Animals↗