a frog-based pregnancy test -- 3/07/18
Today's selection -- from Emergent Ecologies by Eben Kirksey. The use of frogs in a pregnancy test, known as the "Hogben test" after British originator Lancelot Hogben, represented a breakthrough in the management of pregnancies. Frog use in these tests became popular: The tests did not kill them and they could be reused since they could live up to 15 years in captivity:
"The frog Xenopus laevis captured the imagination of researcher Edward R. Elkan, and many other researchers [in the 1930s], shortly after scientists in South Africa discovered it can perform a surprising trick: this amphibian can be used to divine pregnancy in humans. The methods for conducting the Xenopus pregnancy test are simple. They were described in plain language by Elkan, who popularized the test with an article in the British Medical Journal in 1938: 'The test proper starts with the collection of the urine. It seems wise to limit the patient's intake of fluids so far as possible .... Some 6 ounces of morning urine are collected in a clean -- not necessarily sterile -- bottle and sent to the laboratory.' The article goes on to describe different parts of the frog's anatomy where a small amount of urine can be injected: one popular injection site was in the thigh of the hind leg (in the dorsal lymph node), while others preferred the frog's belly (peritoneal cavity). 'The frogs are slippery and difficult to hold,' notes Elkan. 'I find that the easiest way of dealing with them is to hold them in a coarse meshed net and to inject through the mesh.' The urine of pregnant women contains a hormone called human chorionic gonadotropin (HCG). When HCG is injected into a female Xenopus frog, she will release eggs within six to twenty-four hours. ...
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| Xenopus laevis |
"In the 1930s and 1940s, citizens worked with scientists to popularize the Xenopus pregnancy test. Reproductive rights activists with Planned Parenthood joined researchers to advocate for adopting the frog pregnancy test as a clinical standard. 'Some of the objections to this test raised by earlier observers seem to have become invalid,' Elkan writes. 'The early detection of pregnancy remains important from the psychological and the gynecological points of view. A method which allows the diagnosis to be made within a few hours should be welcome.'
"Scientific work in the realm of endocrinology took place alongside a popular mass movement aimed at 'challenging the traditional limits of people's control over their own lives.' As women were liberated, as they embraced emergent birth control technologies, diverse animals were kept in cages. Alongside frogs, mice and rabbits were also used for pregnancy testing. In the late 1920s, a German chemist, Selmar Aschheim, helped design the 'A-Z test,' which involved repeatedly injecting five female mice with a woman's urine over several days. The mice were killed, dissected, and then examined to see if their ovaries were enlarged. Swollen ovaries signaled a pregnancy. The Friedman test substituted rabbits for the mice in the late 1920s and led to the association in popular culture of rabbit killing with pregnancy testing. With the rabbit test, human urine was injected into an unmated female bunny and the animal's ovaries were later checked for morphological changes. The rabbit died no matter the result. The Xenopus pregnancy test became a more ethical and economical test when compared to the rabbit or mouse test. The frogs were not killed and, if treated well, lived up to fifteen years in labs. They could be reused for pregnancy testing every couple of months. But, since some lab technicians were uncomfortable handling frogs, many continued to use the rabbit test."
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