How Asian flu went global
The World Health Organization has shown how the influenza virus A/Asia/57 spread from China to every continent in six months. A number of significant features have been found which have led to a better understanding of the epidemiology of influenza.
It seems that people over the age of 70 in the Netherlands, Australia and the US have proved to have antibodies against the virus, so it may be related to the virus which caused the 1889 pandemic. It also seems that shiploads of infected people have played a bigger part in transmitting the disease than isolated cases carried by air. The summer weather in Europe and North America has put some restraint on the virus, yet it spread rapidly in the tropics.
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Of even greater interest is work determining whether animals play a part in transmitting influenza to humans. In particular, it is well known that pigs suffer from influenza and that earthworms, which the pigs eat, can transmit the disease from one pig to another. It may turn out that pigs are the real reservoirs of the virus.
Free radicals in tobacco smoke
Dr Hilda Johnston writes in Nature that cigarette smoke may give rise to cancer because it contains 鈥渇ree radicals鈥� 鈥� incomplete chemical molecules, electrically uncharged but very reactive. These may have escaped detection until now if samples of cigarette smoke used for analysis have been exposed to light.
Two years ago research showed that cigarette smoke dissolved in benzene is fluorescent, but that the fluorescence is diminished by exposure to light, and even more by UV light. This suggested there were at least two compounds which might escape analysis but would reach smokers鈥� lungs. If the fluorescence is due to the presence of free radicals it may be possible to detect them by exploiting their characteristic response to a magnetic field.
From The New 杏吧原创, 26 December 1957