Research on anthelmintics
digital file Colour Sound 1962 37:50
Video not currently available. Get in touch to discuss viewing this film
Summary: This is an archival scientific film describing in detail the life-cycles of intestinal worms and the procedures employed in the laboratories of the Wellcome Foundation Ltd. for evaluating the efficacy of anthelmintics, with particular reference to the treatment of hookworm in man and nematodiriasis in sheep. 8 segments.
Title number: 17844
LSA ID: LSA/21001
Description: Segment 1 Opening titles. A shot of hookworms attached to the intestinal mucosa is shown. The voice-over commentary explains that an infestation of hookworms causes aneamia, physical debility and mental depression in the host, and that research into more effective drugs to counter hook worms has been slow to come. The two most common species of hookworm are shown: ancylostoma duodenale and necator americanus giving rise to the disease ancylostomiasis. The regions of the world where hookworms are most common are given as well as their taxonomy. Nematodariasis parasitic infestation in lambs is shown and the economic effects explained. Time start: 00:00:00:00 Time end: 00:04:54:08 Length: 00:04:54:08 Segment 2 Microscopic shots of nippostorngylus muris and nematospiroides dubius are seen. A nippostorngylus muris female lays her eggs and the development of the egg into a third stage larvae is shown microscopically. The commentary explains that this is the infective stage. Nematodirus fillicollis third stage larvae are shown and the worms are ready to enter the body of the host. Time start: 00:04:54:08 Time end: 00:10:00:12 Length: 00:05:06:03 Segment 3 Nematode eggs hibernate in herbage through the winter and hatch in spring, when young lambs are grazing and susceptible to infestation. Microscopic footage of them clinging to an intestine is shown. The nematodespiroides dubius life cycle is explained. It is shown alive (microscopically) in a mouse, with infected larvae forming nodules during the final stage of development - they then rupture. The infected larvae of nippostrogylus muris (alive in a rat) and hookworm penetrate the host via the skin. There is a shot of an African man dressed only in shorts, his bare feet putting him at risk of infection. Active third stage nippostrogylus muris are placed near the skin of a rat and the larvae are seen crawling down the hairs and entering the skin, into the circulatory system to the lung and then to the intestinal tract via the trachea. These parasites can only reproduce outside the host so re-infection in humans can be prevented by proper hygiene and footwear. Time start: 00:10:00:12 Time end: 00:13:30:05 Length: 00:03:29:22 Segment 4 The commentary describes how it is more difficult to eliminate a disease like nematodoriasis in lambs than it is in humans. If prevention is impossible, drug therapy must be used. Until 1958 there was no treatment for lambs whereas humans were prescribed Tetrachloroethylene - there is a shot of a man being given a dose - however the drugs have nasty side effects. Laboratory shots show researchers looking for newer more efficient cures. We see them carrying out experiments on small animals as part of their research into a treatment for nippostronylus muris in rats, including harvesting the stools of white rats and examining them under a microscope. The microscopic images are shown, then the stools are treated with charcoal and incubated. Time start: 00:13:30:05 Time end: 00:20:06:12 Length: 00:06:36:07 Segment 6 Practical tests are carried out on lambs. The results detailing the effectiveness of Bephenium as a treatment for worms in lambs are shown using diagrams and graphs. Time start: 00:24:09:00 Time end: 00:28:24:11 Length: 00:04:15:11. Segment 7 Before Bephenium can be tested on humans, intermediary trials have to take place. We see shots of dogs and cats with hookworms receiving worming tablets. Microscopic shots of the human hookworm are shown. Acute and chrinoc toxicity testing on mice, rats and dogs samples of their blood and urine are shown as markers of the success of the drug. Pharmacologists also carry out testing of the drug on the heart and major bodily functions. Time start: 00:28:24:11 Time end: 00:32:56:03 Length: 00:04:31:21. Segment 8 Numerous shots of histological examinations of the organs of animals used in acute and chronic toxicity tests are shown, in this instance a dog's brain. Human trials of Bephenium can now be carried out Ceylon was the country of choice as there are so many cases of hookworm infestation each year. We see a shot of a man in hospital being administered the drug which appears to produce much milder side effects than the older drug, Tetrachloroethylene. A graph illustrates the efficacy of the drug and shots of Bephenium being produced in the laboratory are shown while the commentary expounds the achievement of finding this new anthelmintic. Time start: 00:32:56:03 Time end: 00:37:50:19 Length: 00:04:54:16
Credits: Produced by Dr. Denis Ward photographed by Denis Ward and Charles French.
Keywords: Tetrachloroethylene; Nematoda -- parasitology; Ancylostomatoidea; Antinematodal Agents; Ancylostoma -- drug therapy; Anthelmintics -- therapeutic use; Helminths -- drug therapy
Locations: United Kingdom; England; Kent; Beckenham; Wellcome Chemical Research Laboratories
Related
Comments