Spirometra
The Growth Hormone-like Factor Produced by the Tapeworm Spirometra mansonoides Specifically Binds
Receptors on Cultured Human Lymphocytes, by C. K. Phares and D. J. Watts © 1988 The American Society of
Parasitologists.
Abstract
Plerocercoid larvae of the tapeworm Spirometra mansonoides produce a factor with activities similar to those of
growth hormone (GH). Highly selective receptors for GH have been described on cultured human lymphocytes (IM-9
cells) and these cells have been used as a model of binding essentially restricted to human GH (hGH). We compared
the displacement of [sup125/supI]hGH by hGH and partially purified plerocercoid growth factor (PGF) in assays using
rabbit hepatic membranes and IM-9 cells. PGF displaced [sup125/supI]hGH from both rabbit hepatic membranes and
IM-9 cells in a dose-dependent manner (r 0.98). These results show that PGF specifically binds to hGH receptors on
human IM-9 cells and suggest the possibility that PGF will have somatotropic activity in humans.
http://www.jstor.org/pss/3282278
somatotropic hormone - a hormone produced by the anterior pituitary gland; promotes growth in humans
http://www.thefreedictionary.com/somatotropic+hormone
Am. J. Trop. Med., s1-21(3), 1941, pp. 399-425
Copyright © 1941 by American Journal of Tropical Medicine
http://www.ajtmh.org/cgi/content/abstract/s1-21/3/399
Experimental Human Infection with the Sparganum Larva of Spirometra Mansonoides (Mueller, 1935)1
Justus F. Mueller AND Frederick Coulston
Syracuse University College of Medicine and New York State College of Forestry
1. The authors experimentally infected themselves with the sparganum larva of Spirometra mansonoides on November
26, 1938, by introducing the heads of three larvae beneath the skin of the left arm over the biceps muscle, two into
Mueller, one into Coulston. These heads measured at most 2 mm. in length.
2. On February 2, 1939 a sparganum 50 mm. in length, representing a growth of 48 mm., was removed from
Coulston's arm after it had migrated from the site of injection to the region of the axilla, a distance of about 12 cm.,
where it was found under the deep fascia.
3. On February 3, 1939 a sparganum 60 mm. long, representing a growth of about 58 mm., was removed from the
biceps muscle of Mueller under local anesthetic. Only a fragment of the tail end of the other worm, about 10 mm. long,
could be found at this time.
4. On March 4, 1939, a second sparganum about 60 mm. long was removed from Mueller.
5. This last sparganum was fed to an ova-free, known unin-fected cat, and produced a normal adult worm 50 inches in
length. Ova of this worm were cultured and the procercoids found infective for rhesus monkeys demonstrating that the
worm had not suffered any loss of vigor by human passage.
6. Symptoms associated with infection were local induration at the site of the worm, periodic giant urticaria, edema, and
erythema. These periodic symptoms appeared to coincide with movements of the worm which from time to time broke
out of the surrounding reaction zone, presumably liberating into the circulation walled off toxins. These periodic local
reactions were attended by chills and fever and feelings of profound depression and malaise.
7. Eosinophilia appeared, rising to 10 per cent in Mueller on the 32nd day, and to 9 per cent in Coulston on the 23rd to
the 27th day.
8. A positive skin reaction was elicited to scratch tests or intradermal tests with antigens prepared from Spirometra
mansonoides adult and sparganum, T. crassicollis adult and cysticercus, T. pisiformis adult and cysticercus, and T.
serrata. Also with the substance of a plerocercoid found in Great Lakes ciscoes. Antigens for intradermal use were
prepared by Dr. J. T. Culbertson of Columbia University. They were not lipid free.
9. While the subjects were still infected skin testing did not elicit any immediate reaction, only delayed reaction after
about 10 or 12 hours.
10. After removal of the worms the subjects developed an immediate reaction to skin tests, while retaining the delayed
reaction. The delayed reaction in the case of the scratch tests is recurrent several times at 10 to 12 hour intervals.
11. In over 60 control skin tests on volunteers only one "false positive" was obtained, and that in the case of a student
who gave a history suggesting that he may at one time have been infected with a sparganum.
12. The two authors still show strongly positive reactions to skin tests at the present writing (January 8, 1941), almost
20 months after removal of the worms.
13. Complement fixation tests were unsatisfactory on the two experimentally infected humans, possibly because of the
employment of too weak an antigen, or more probably because the serum was kept for too long a time before
performing the tests.
14. Pathological changes were extensive and in the nature of chronic inflammatory reaction, with local necrotic areas
surrounding the worm.
15. In both subjects the spargana exhibited migration, in one case penetrating and forming a gallery in the biceps
muscle, in the other passing to the region of the axilla. Encapsulation though extensive was not sufficient to wall off the
spargana.
16. With the establishment of Spirometra mansonoides as a potential human parasite physicians throughout the
geographic range of the worm should be informed of its nature and educated to watch out for it. The use of antigens of
tapeworm substance for diagnosis is recommended.
17. It further appears that this parasite may constitute another potential waterborn disease throughout its range in the
eastern United States, and render swimming in certain natural bodies of water carrying the copepod intermediate host,
or the use of shallow well or spring water, etc., dangerous.
18. Such antigens as we used are not specific, since they retain the lipid fraction. Spirometra antigens elicited positive
reactions in hydatid disease patients. It is probable that a more specific antigen can be prepared by preliminary
removal of the lipids before extraction.
Received February 2, 1941.
1 This research and its publication were aided by several grants from the Hendricks Research Fund of the Syracuse
University College of Medicine.