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3346. BSE: a decade on--Part I.
Bovine spongiform encephalopathy (BSE), popularly known as "mad cow disease", was discovered in 1986 and has accounted for the deaths of over 165,000 cattle in the UK (by the end of January, 1997) with about 34,000 (mainly dairy) herds involved. The syndrome in the cow includes changes in posture and temperament, apprehension, and loss of coordination. There are many parallels with scraple in sheep, with similar neuropathological changes in the hindbrain that give it a spongiform appearance under the microscope. The facts have been broadly reviewed in The Lancet in 1990 and 1993, and in much more detail elsewhere. In a two-part article, the first of which appears here, we now summarise recent developments.
3348. Three new human herpesviruses (HHV6, 7, and 8).
Three new human herpesviruses have been recognised in the past decade, and add further to our knowledge of human diseases with potential viral aetiologies. These viruses can be included with the other known human herpesviruses found in normal body secretions, particularly saliva. HHV6 and HHV7 have been associated with febrile illnesses and the childhood disease, exanthem subitum. HHV8 seems to resemble Epstein-Barr virus in its possible transforming properties and poses challenging questions for researchers directed at determining its potential role in lymphomas and Kaposi's sarcoma. Research on these herpesviruses can provide valuable new insights into virus/host relationships and mechanisms involved in replicative and latent stages of virus infection.
3351. Peptide antibiotics.
The era of the "classical antibiotic" may be over. The emergence of resistance has seen to that. Yet no truly novel class of antibacterial agent has come on the market in the past 30 years. Currently there is great interest in peptide antibiotics, especially the cationic peptides. Thousands of such molecules have been synthesised and just a few are entering clinical trials. Because they kill bacteria quickly by the physical disruption of cell membranes, peptide antibiotics may not face the rapid emergence of resistance.
3353. Aetiology of acute leukaemia.
Ionising radiation, in high dose and with acute exposure, is a factor that has been implicated in leukaemogenesis, but what is the evidence for leukaemogenesis and exposure to diagnostic X-rays, to natural terrestrial or cosmic ionising radiation, to electromagnetic fields, or to nuclear energy? Why is population mixing and infection a possible explanation for the clusters of childhood acute leukaemias around the nuclear processing plants of Sellafield and Dounreay? These questions, as well as how chemical agents, including therapeutic substances, might contribute to leukaemogenesis, are discussed in this last article in the leukaemia series.
3356. The treatment of acute leukaemia.
Developments in supportive care, new regimens for induction of remission and consolidation therapy, and bone-marrow transplantation have improved the outlook for patients with acute leukaemia. The outlook, though, is influenced by age and factors related to the biology of the disease. In acute myeloid leukaemia age is such an important factor that it determines approach to therapy. Overcoming resistance to chemotherapy is an area that needs much attention.
3358. Molecular genetics of acute leukaemia.
The outlook for patients with acute promyelocytic leukaemia has improved vastly with the use of all-trans retinoic acid. The development of this therapeutic agent stemmed from the finding that an abnormality of the retinoic acid receptor is involved in this disease. In the search for other molecular abnormalities in the acute leukaemias that might serve as therapeutic targets, the chromosomal translocations associated with this group of disorders have been helpful in indicating where to look for potential cancer genes. Some common signal-transduction pathways through which different such genes act have been identified, and compounds that interfere with these pathways are already being screened for.
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