Woodchucks used in Taiwan's research into Hepatitis B

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Woodchucks used in Taiwan's research into Hepatitis B

The course of Hepatitis B in woodchucks is remarkably similar to what is seen in human patients, and National Taiwan University's Liver Research Center has been using nearly 100 of the little critters for eight years now in hopes of developing a cure for chronic Hepatitis B, as well as medications against liver cancer. NTU had never raised woodchucks, so the school sent researchers to the U.S. to learn about them. Because the animals are sensitive to heat and hibernate in winter, they must be kept at temperatures between 16 and 18 degrees Celsius. The light cycle is adjusted to mimic the seasons in the United States, and stainless steel cages are used to house them, as nothing less can withstand the animals' super-sharp incisors. "But woodchucks are so mischievous, even the bolts of the cage doors and the feeding tubes protruding into the cage get destroyed!" NTU veterinary technologist Lin Xiuling says that when handling the animals, researchers must don two layers of protective gloves, and must watch their fingers carefully to avoid bites. The animals are really not well suited to life as pets, and Lin feels badly about the ones that are sold to pet shops. Lin says that woodchucks like to hide out in burrows. A small cage shaped like a mailbox, with a hinged lid, can be put near the burrow, and the curious animals will climb inside of their own accord. Because the chucks have to be held down in order to be anesthetized, smart individuals have learned to roll over and lie on their backs to keep researchers at bay, and techs are hard-pressed to get them into another position. An even more troublesome characteristic of the woodchucks is hibernation. Each year, they are active only from April through October. "After October, the animals get fatter and fatter, and their movements get slower and slower. Their serum chemistry also changes and becomes thicker, so that it is difficult to anesthetize them." Lin says that from November through January, the woodchucks are allowed to snooze dead to the world, and the lab likewise does not disturb them during their mating season, which occurs in February and March. Because of the popularity of hepatitis B carrier woodchucks, NTU was unable to purchase any more for two years after bringing the initial group in from the US. The only way forward was to learn to raise them. In cooperation with the Taipei Zoo, the Center's vice director, Wu Huilin, says that the researchers raised non-carrier woodchucks in an environment like that of the wild, and waited until the young were weaned before taking some of them back to the lab to be infected with the virus. Wu says that imported laboratory bred carrier animals can go for US$2,000 each, three times the price of non-carrier woodchucks, and setting up an animal model of a disease requires many individuals. As a result, it's best to be able to breed them locally. NTU has already completed genetic sequencing of woodchuck hepatitis B virus, and has selected genes 2 and 30 as being related to the immune response. But much work is still required before this progress will translate into the goal of a treatment for hepatitis B.

Source:Liberty Times(2006/08/28 13:50:26)

http://english.www.gov.tw/TaiwanHeadlines/index.jsp?categid=198 & recordid=98727