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Biomedical subjects

Caren Broadhead

Publications and source records attributed to Caren Broadhead.

6 recordsLinked to original sources

Identification of angiotensin I in a cyclostome, Lampetra fluviatilis.

Angiotensin I (ANG I) was isolated from incubates of plasma and kidney extracts of the river lamprey, Lampetra fluviatilis, using eel vasopressor activity as an assay during purification. Its sequence was Asn-Arg-Val-Tyr-Val-His-Pro-Phe-Thr-Leu as determined by the sequence analysis and mass spectrometry. The sequence was confirmed by identity of the elution profile with the synthetic peptide in two different reverse-phase columns of high-performance liquid chromatography. Lamprey ANG I produced dorsal-aortic pressor responses in L. fluviatilis but the rise was very small in comparison to that produced by angiotensin II. Angiotensin III produced an even bigger increase. It was not possible to demonstrate a difference in response to Asn(1) (lamprey) ANG I and Asp(1) (human) ANG I. The present study directly demonstrated the presence and biological activity of the renin-angiotensin system in the most primitive extant vertebrates, the cyclostomes. Thus the renin-angiotensin system is a phylogenetically old hormonal system that is present throughout the vertebrates.

Analysis of Variance↗

Preclinical safety evaluation using nonrodent species: an industry/welfare project to minimize dog use.

This review of the dog, the primary nonrodent species used in toxicology, and its use in the safety evaluation of pharmaceuticals, provides data on the number used in particular projects in an effort to establish a baseline from which some minimization can be measured. Opportunities for reduction and replacement, as identified by a European Industry/Welfare Steering Group, are discussed. The three distinct areas of potential approaches to minimize dog use are categorized as industrial cooperation/data sharing, achieving best practice in study design, and assessing the need for a particular study. The Steering Group prioritized the approaches based on the impact on the number of animals used, the impact on the welfare of the remaining animals, the potential for industry's acceptance of the scientific approach, the potential for regulators' acceptance of the validated approach, and the time/cost of evaluation or implementation. Examples of each category are presented, and the work needed to facilitate industry/regulatory change is discussed.

Animal Testing Alternatives↗

The implications of microarray technology for animal use in scientific research.

Microarray technology has the potential to affect the number of laboratory animals used, the severity of animal experiments, and the development of non-animal alternatives in several areas scientific research. Microarrays can contain hundreds or thousands of microscopic spots of DNA, immobilised on a solid support, and their use enables global patterns of gene expression to be determined in a single experiment. This technology is being used to improve our understanding of the operation of biological systems during health and disease, and their responses to chemical insults. Although it is impossible to predict with certainty any future trends regarding animal use, microarray technology might not initially reduce animal use, as is often claimed to be the case. The accelerated pace of research as a result of the use of microarrays could increase overall animal use in basic and applied biological research, by increasing the numbers of interesting genes identified for further analysis, and the number of potential targets for drug development. Each new lead will require further evaluation i n studies that could involve animals. In toxicity testing, microarray studies could lead to increases in animal studies, if further confirmatory and other studies are performed. However, before such technology can be used more extensively, several technical problems need to be overcome, and the relevance of the data to biological processes needs to be assessed. Were microarray technology to be used in the manner envisaged by its protagonists, there need to be efforts to increase the likelihood that its application will create new opportunities for reducing, refining and replacing animal use. This comment is a critical assessment of the possible implications of the application of microarray technology on animal experimentation in various research areas, and makes some recommendations for maximising the application of the Three Rs.

Animal Testing Alternatives↗