Đang chuẩn bị liên kết để tải về tài liệu:
Mims pathogenesis of infectious disease - part 8

Kể từ khi sốt là một phần tiếp theo liên tục của nhiễm trùng, nó là tự nhiên giả sử rằng nó có một số chức năng kháng khuẩn. Thomas Sydenham trong thế kỷ thứ mười bảy đã viết rằng 'Sốt là một công cụ hùng mạnh mà thiên nhiên mang vào thế giới để chinh phục kẻ thù của cô. | 9 Recovery from Infection 331 respiratory tract as a result of virus-phagocyte interaction. The haemagglutinin and or neuraminidase surface glycoproteins of the virion are responsible. Since fever is such a constant sequel of infection it is natural to suppose that it has some antimicrobial function. Thomas Sydenham in the seventeenth century wrote that Fever is a mighty engine which nature brings into the world for the conquest of her enemies . Bodily functions are profoundly disturbed by fever. Metabolic activity is increased in phagocytic cells and studies in vitro show that there are large increases in T-cell proliferation and in antibody production at febrile temperatures. The evidence however is disappointing. Temperature-sensitive mutants of certain viruses are often less virulent and experimental virus infections can sometimes be made more severe by preventing fever with antipyretic drugs. When fever is induced in infected animals by raising the environmental temperature there are also other complex physiological changes making it difficult to interpret such experiments. In two bacterial infections gonorrhoea and syphilis the microbes themselves are actually killed by febrile temperatures but in the natural disease these temperatures are rarely reached. Before the introduction of antibiotics patients with these two diseases were infected with malaria in order to induce body temperatures high enough to eradicate the infection following which the malaria was treated with quinine . If fever is of value to the host one might expect microbes to attempt to prevent it. Vaccinia virus which normally fails to cause fever in mice produces a soluble receptor for IL-lb the fever mediator and virus strains lacking the gene for this receptor do cause fever. We may ask whether T pallidum actively inhibits the fever response. Fever is costly in energy and is an ancient bodily response having evolved with the vertebrates over hundreds of millions of years. Perhaps one day .