Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.574251
Title: Two North American arthropods of clinical significance : their venoms and the development of specific antivenoms
Author: Jones, Russell Guy Ashley
Awarding Body: Queen Mary, University of London
Current Institution: Queen Mary, University of London
Date of Award: 2001
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Abstract:
Large volumes of antisera were generated against Apis mellifera venom with which to develop a novel, platform technology for the inexpensive production of antivenoms. The ovine sera contained high levels of specific antibodies which neutralised the myotoxic, phospholipase A2 and in vivo activities of the venom. Methods of processing the antisera to provide Fab or F(ab')2 were investigated. F(ab')2 was thought to be clinically advantageous and, by determining the conditions necessary for the preferential breakdown of Fc and serum components other than F(ab')2' it was possible to avoid salt precipitation. Diafiltration was then used to remove most of the unwanted small fragments and anion-exchange chromatography to remove any remaining acidic impurities such as pepsin and large aggregates. The F(ab')2 was -97% pure and the yield - 199 per L of serum. This is the first specific therapy for mass envenoming by European or Africanised bees. Spiders of the genus Latrodectus (black widows) are distributed widely and about 2,500 bites are reported annually in the USA. The neurotoxic effects of the venom were studied on the isolated phrenic nerve diaphragm preparation. Low venom concentrations (1mg/L) were stimulatory while high concentrations (10mg/L) caused nerve blockade which was potentiated by increased calcium levels. Although effective, the Merck antivenom, which is unprocessed horse serum, causes unacceptable risks. The second purpose of this project was to prepare an improved Latrodectus spider antivenom using the new platform technology. Different immunisation schedules were studied to optimise the humoral immune response. Sheep immunised with 2mg La. hesperus venom produced the highest levels of specific antibodies as assessed by ELISA, using the isolated nerve diaphragm preparation or in vivo in mice. The new process provided a pure F(ab')2 antivenom retaining 78% of the original antisera ED so neutralising power and was - twice as effective as the Merck antivenom.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.574251  DOI: Not available
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