摘要:

African trypanosomes are protozoan parasites that cause a number of diseases of man and domesticated animals in large regions of sub-Saharan Africa. The diseases have proven to be particularly difficult to prevent or to effectively treat due to features of both the trypanosome and the insect vector, the tsetse fly. The habitat of the tsetse and its resistance to insecticides have rendered vector control efforts ineffective. Attempts to develop a vaccine against the African trypanosomes has been dwarfed by the parasite's ability to change the composition of its exposed surface antigens. This process of antigenic variation allows the parasite to avoid the host's immune response and presents the host with a seemingly endless antigenic repertoire. Since conventional approaches to the control of African trypanosomiasis have largely met with failure, there has been a renewed interest in identifying novel aspects of the biology, biochemistry, and molecular biology of trypanosomes that might be exploited to develop new targets for vaccines or chemotherapy. Importantly, this research has opened a virtual Pandora's box of exciting biochemical and molecular surprises, which makes the African trypanosomes not only important medical pathogens but also an exciting experimental system for the basic scientist. In this review, the authors will describe some of the most recent and intriguing developments in the field of molecular parasitology.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The sympathetic nervous system may play a pivotal role in the development of primary (essential) hypertension, and is almost always involved in the increasingly common occurrence of postural hypotension. This report reviews the recent evidence for and against stress-induced activation of sympathetic activity leading to a hyperkinetic circulation as an initiating mechanism for most hypertension. Then, attention is directed to the role of altered sympathetic nervous system responsiveness in the development of postural hypotension. Finally, therapy for this syndrome is reviewed.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID