-medicine.org/inc/biomed/medicine-news.asp <a href="http://feeds.bio-medicine.org/latest-medical-newsDate:12/26/2007">http://feeds.bio-medicine.org/latest-medical-newsDate:12/26/2007</a> A mechanism which can lead to hay fever and other allergic reactions, by preventing the immune system from regulating itself properly, has been discovered by scientists.