Posted on 01/22/2006 4:38:30 PM PST by Virginia-American
Researchers have found stronger evidence for a link between a parasite in cat faeces and undercooked meat and an increased risk of schizophrenia.
Research published today in Procedings of the Royal Society B, shows how the invasion or replication of the parasite Toxoplasma gondii in rats may be inhibited by using anti-psychotic or mood stabilising drugs.
The researchers tested anti-psychotic and mood stabilising medications used for the treatment of schizophrenia on rats infected with T. gondii and found they were as, or more, effective at preventing behaviourial alterations as anti-T. gondii drugs. This led them to believe that T. gondii may have a role in the development of some cases of schizophrenia.
Dr Joanne Webster from Imperial College London, and lead researcher said: "Although we are certainly not saying that exposure to this parasite does definitely lead to the development of schizophrenia, this and previous studies do show there may be a link in a few individuals, providing new clues for how we treat toxoplasmosis and schizophrenia."
Previous epidemiological and neuropathological studies have indicated some cases of schizophrenia may be associated with environmental factors, such as exposure to the parasite T. gondii. At the same time several of the medications used to treat schizophrenia have been shown to posess anti-parasitic and in particular anti-T.gondii properties. This led the authors to suspect that the anti-psychotic activity of these medications may be due to their inhibition of these parasites.
When the rats were given Haloperidol, an anti-psychotic, and Valporic acid, a mood stabiliser, the behavioural symptoms of T.gondii were reduced. They found the drugs were able to limit the suicidal feline attraction by which the rats became less aware of the dangers of cats.
Dr Joanne Webster added: "By showing that drugs used to treat schizophrenia affect the parasite T. gondii, this does provide further evidence for its role in the development of some cases schizophrenia. It may be that anti-psychotic drugs work partly by parasite inhibition, and this could lead to new medicine and treatment combinations."
The researchers have already begun human clinical trials using anti-T. gondii treatments as adjunct therapies for schizophrenia with researchers at Johns Hopkins University.
Notes to editors:
1. Parasites as causative agents of human affective disorders? The impact of anti-psychotic, mood stabiliser and anti-parasite medication on Toxoplasma gondiis ability to later host behaviour, Procedings of the Royal Society B.
2. Consistently rated in the top three UK university institutions, Imperial College London is a world leading science-based university whose reputation for excellence in teaching and research attracts students (11,000) and staff (6,000) of the highest international quality. Innovative research at the College explores the interface between science, medicine, engineering and management and delivers practical solutions that enhance the quality of life and the environment - underpinned by a dynamic enterprise culture.
In the US, it's about 15%. In France, it's over 40%. Discuss.
If a cat stays indoors, they do not come in contact with any parasites.
DNA Offers New Insight Concerning Cat Evolution
The New York Times | January 6, 2006 | By NICHOLAS WADE
Posted on 01/05/2006 8:39:51 PM PST by MRMEAN
http://www.freerepublic.com/focus/f-news/1552856/posts
Cleanliness and hygiene.
That was a very short discussion.
You forgot to work in the schizophrenia angle :)
That's what happens when you don't clean the litterbox.
The Masters take care of their property.
Those Who Must Be Fed.
I especially like the anosmia facts website.
it is a chemical in armpit sweat
Presumably not a pheromone!
Diabetics smelling "sweet", makes sense. I've smelled people with kidney failure, the skin secretes urea ("uremic frost")
... A signature cocktail of alkanes and benzene derivatives are exhaled by people with lung cancer.
I assume it's something along these lines that cancer-detecting dogs sniff
Are you sure you don't mean cowpox? That was a related disease to smallpox. Interestingly, Jennings (sp)? invented the smallpox vaccine by observing that milkmaids rarely contracted smallpox due to their exposure to cowpox.
Actually, I think the name was Jenner.
Cat poop bummer.
I believe it. We've had cats for 50+ years, and both my personalities believe it.
HOW?? Breathing the fumes? Eating it?? Who the h*ll touches cat feces..with open wounds???
Much better explained here by Cornell:
http://www.vet.cornell.edu/fhc/resources/brochure/toxo.html
"Toxoplasmosis in Cats
Toxoplasmosis, a disease of cats and other mammalian species, is caused by a parasitic protozoan, Toxoplasma gondii. Protozoa are single-celled organisms that are among the simplest creatures in the animal kingdom. Although infection with Toxoplasma is fairly common, actual disease caused by the parasite is relatively rare.
The Life Cycle of Toxoplasma
Cats, domestic and wild, are the definitive host (host in which the adult, or sexually mature stage, of the parasite is produced) and are the parasite's primary reservoir of infection. Domestic cats are important in transmission of Toxoplasma to other animals and human beings, which become involved only as intermediate hosts of the parasite. Consumption of raw meat tissues is another important means of transmission.
Cats acquire Toxoplasma infection by eating any of the three infective stages of the parasite: cyst, oocyst, or tachyzoite. Following ingestion of cysts in infected prey (rodents or birds), the intraintestinal infection cycle begins. This cycle occurs only in members of the cat family. The organisms multiply in the wall of the small intestine and produce oocysts, which are then excreted in great numbers in the feces for two to three weeks. Within five days the shed oocysts may sporulate, becoming infectious to other animals and to humans. Sporulated oocysts are highly resistant to environmental conditions and can survive in moist shaded soil or sand for many months.
During the intraintestinal infection cycle in the cat, some Toxoplasma organisms released from the ingested cysts penetrate more deeply into the wall of the intestine and multiply as tachyzoite forms. Very soon these forms spread out from the intestine to other body sites, starting the extraintestinal infection cycle. Eventually the cat's immune system restrains this stage of the organism, which then enters a dormant or "resting" stage by forming cysts in muscles and brain. Most cysts probably remain dormant for the life of the host. The extraintestinal infection cycle occurs not only in cats but also in the intermediate hosts (including humans).
Most healthy exposed cats shed oocysts during acute infection with Toxoplasma, but will not shed them after the acute infection. Even in those few cats that do re-excrete oocysts after another exposure to Toxoplasma, the number of oocysts shed is smaller and may even be insufficient to transmit the parasite effectively.
Ingestion of tissue cysts in infected prey or in other raw meat is probably the most common route by which cats are exposed to Toxoplasma. Congenital infection (transmission from mother to fetus) occurs in sheep, goats, and humans, but is much less common in cats."
"Pregnant women used to be warned to stay away from cat litter boxes, for fear of the toxoplasmosis."
They still are. Pregnant women with cats are tested for the anti-bodies. If PRESENT, they can keep the cat. (It's only NEW infections DURING pregnancy that cause problems, as the baby is invaded.)
"Could schizophrenia (in some cases) be a result of prenatal exposure?"
Maybe, but a pregnant woman who is NEWLY infected can end up with a BLIND and otherwise seriously-damaged baby.
"That was a related disease to smallpox. Interestingly, Jennings (sp)? invented the smallpox vaccine by observing that milkmaids rarely contracted smallpox due to their exposure to cowpox."
That is also the reason for the expression "milkmaiden skin" or similiar expressions --- cow pox did not scar the face.
As an aside, almost all adults (until recently) had small pox scars on their faces --- painters politely left them out as a matter of course.
Maybe.
But I recall an earlier study that showed increased reckless behavior in adults newly infected with the disease.
Men (tended to) become anti-social recluses
Women (tended to) become slutty.
It went away as the body defeated the organism -- which did infect nerves.
Most kids get this BTW (sand boxes), it's the rare adult who does not have anti-bodies.
The symptoms are flulike and go away.
Only infants/babies is it a real problem (blindness).
ya know I have felt a lot better since Motorola went to kitty Heaven.
Maybe that's my problem ... :-o
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