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There is some (fairly weak) evidence linking toxo infection with psychological problems in humans. Indeed, the fact that in France 80% of the population test positive for toxo could explain a lot...
Toxoplasma research in patients affected by psychiatric disorders is going further and certainly we deserve an update around here. For the discussion, to keep this topic alive.
Hi Ikothe drugs work against replicating toxoplasma infection, but I don't think they are active against the latent tissue cysts - these are metabolically inert most of the time and therefore insensitive to drug action. A similar situation exists for the bacterium M. tuberculosis, although this can (thankfully) be eliminated. These cells enter a quiescent state during which they are invunerable to anti-tuberculous therapy. That's why a course of treatment needs to last 6 months in order for the majority of the bacteria to have re-awakened for long enough to respond to the drugs. This is part of the reason that this infection is so difficult to treat, that resistant forms (MDRTB) are becoming more common and that the global TB death toll is now 5000 people per day. A sobering thought. Chris
I read that for particular cases or Q-fever antibiotic treatment for life should be recommended.Talking about occult persisting infections!They should be investigated more extensively these days, don't you think?Now that we achieved wonderful diagnostic tools like PCR, we seem to have lost interest in underdiagnosed occult infections and their hypothetical consequences (autoimmunity, some lymphomas, etc).Is this happening for a mere lack of funds and investment money or what?iko
Quote from: iko on 08/05/2007 13:30:34Several cases of drug-induced disease have been reported. Dermatomyositislike skin changes have been reported with hydroxyurea in patients with chronic myelogenous leukemia or essential thrombocytosis. Other agents that may trigger the disease include penicillamine, statin drugs, quinidine, and phenylbutazone.more reading from: http://www.emedicine.com/MED/topic2608.htmToxoplasma may cause dermatomyositis.Dermatomyositis rarely goes together with CML:Could Toxoplasma cause some case of CML?I don't know if we can play this game.It is late in the evening, professors andreal scientists are probably all busywriting their papers and don't have timefor silly forums...There are no known causes for CML.The discussion is open: it's an experiment!Allowed search engines: Google - PubMed.EnjoyikoQuote from: iko on 11/05/2007 22:22:23I remember one case only of acute toxoplasmosis in a patient with newly diagnosed CML.Surely that's a coincidence, nevertheless you may start searching for other hints:Cutaneous toxoplasmosis.Leyva WH, Santa Cruz DJ. A case of epidermotropic cutaneous toxoplasmosis is reported. The patient, a 53-year-old man with chronic myelogenous leukemia in blast crisis, received a bone marrow allograft but continued to have severe pancytopenia. Numerous diffuse, palpable, purpuric nodules appeared 21 days after the transplant. Organisms were found within the epidermal keratinocytes--both singularly and in cysts. Dermal and neural infiltration was also present. Toxoplasma gondii was identified on the basis of the ultrastructural features of the parasite. Possible sources of infection include reactivation of a previous latent infection, transmission through a bone marrow allograft, or nosocomial acquisition.J Am Acad Dermatol. 1986 Apr;14(4):600-5. Here you have different hypotheses:- Reactivation of a latent infection helped by immune depression from leukemia and treatment.- Infection transmitted through the bone marrow graft (but 21 days is a bit too fast!). These two suggestions support the 'opportunistic theory': germs prevail BECAUSE of the leukemic process, are very dangerous, but totally unrelated to the real cause of that particular type of leukemia (Lymphoid or myeloid).In this context, infectious agents are frequently defined 'innocent by-standers' instead of 'implicit bastards' (more appropriate, in my personal opinion).- Occult persistent infection (infestation: they are protozoa) unmasked in terminal phase. Toxoplasma and consequent abnormal overridden immune reaction might have stimulated a previously inactive clone of CML precursors and started the leukemic process itself over weeks and months, replacing normal hemopoietic cells and invading liver, spleen and marrow.Little CML clones may harbour in normal people and represent the result of a somatic mutation.Percentage of 'positive' healthy carriers of tiny CML clones would obviously increase with age.So another factor is needed to justify the expansion of the mutated clone.Toxoplasma could be one of a restricted group of germs capable of jamming some crucial point of the complex immune reaction (involving T-cells, macrophages, complex cytokine interactions) evoked by protozoa and other 'fastidious' germs.Helicobacter pylori and mycoplasmas might be in the number.
Several cases of drug-induced disease have been reported. Dermatomyositislike skin changes have been reported with hydroxyurea in patients with chronic myelogenous leukemia or essential thrombocytosis. Other agents that may trigger the disease include penicillamine, statin drugs, quinidine, and phenylbutazone.more reading from: http://www.emedicine.com/MED/topic2608.htm
I remember one case only of acute toxoplasmosis in a patient with newly diagnosed CML.Surely that's a coincidence, nevertheless you may start searching for other hints:Cutaneous toxoplasmosis.Leyva WH, Santa Cruz DJ. A case of epidermotropic cutaneous toxoplasmosis is reported. The patient, a 53-year-old man with chronic myelogenous leukemia in blast crisis, received a bone marrow allograft but continued to have severe pancytopenia. Numerous diffuse, palpable, purpuric nodules appeared 21 days after the transplant. Organisms were found within the epidermal keratinocytes--both singularly and in cysts. Dermal and neural infiltration was also present. Toxoplasma gondii was identified on the basis of the ultrastructural features of the parasite. Possible sources of infection include reactivation of a previous latent infection, transmission through a bone marrow allograft, or nosocomial acquisition.J Am Acad Dermatol. 1986 Apr;14(4):600-5. Here you have different hypotheses:- Reactivation of a latent infection helped by immune depression from leukemia and treatment.- Infection transmitted through the bone marrow graft (but 21 days is a bit too fast!). These two suggestions support the 'opportunistic theory': germs prevail BECAUSE of the leukemic process, are very dangerous, but totally unrelated to the real cause of that particular type of leukemia (Lymphoid or myeloid).In this context, infectious agents are frequently defined 'innocent by-standers' instead of 'implicit bastards' (more appropriate, in my personal opinion).- Occult persistent infection (infestation: they are protozoa) unmasked in terminal phase. Toxoplasma and consequent abnormal overridden immune reaction might have stimulated a previously inactive clone of CML precursors and started the leukemic process itself over weeks and months, replacing normal hemopoietic cells and invading liver, spleen and marrow.Little CML clones may harbour in normal people and represent the result of a somatic mutation.Percentage of 'positive' healthy carriers of tiny CML clones would obviously increase with age.So another factor is needed to justify the expansion of the mutated clone.Toxoplasma could be one of a restricted group of germs capable of jamming some crucial point of the complex immune reaction (involving T-cells, macrophages, complex cytokine interactions) evoked by protozoa and other 'fastidious' germs.Helicobacter pylori and mycoplasmas might be in the number.
An autopsy case of toxoplasmosis associated with myelocytic leukemia.Kishida S, Yoshie Y, Hamamoto Y.Acta Pathol Jpn. 1974 Jul;24(4):541-50.
[Toxoplasmosis and generalized mycosis after treatment of chronic myelosis (author's transl)] [Article in German]Musil A, Friedrich E.Zentralbl Allg Pathol. 1973;117(2):110-7.
Facts do not cease to exist because they are ignoredAldous Huxley
Quotefrom: New Cancer Theory
from: New Cancer Theory
Toxoplasmosis Infection Trick Revealed By Scientists Scientists have provided new insight into how the parasite which causes toxoplasmosis invades human cells. Toxoplasmosis is a parasitic disease, primarily carried by cats. It is transmitted to humans by eating undercooked meat or through contact with cat faeces. ...It is particularly dangerous for pregnant women, whose foetuses can be infected via the placenta, and those with a weakened immune system, such as people infected with HIV. In severe cases, toxoplasmosis can cause damage to the brain and eyes, and even death. ...Now researchers from London and Geneva have determined, for the first time, the atomic structure of a key protein which is released onto the surface of the parasite just before it invades host cells in the human body. They found that the protein known as TgMIC1 binds to certain sugars on the surface of the host cell, assisting the parasite to stick to, and then enter the human cell. ...Using a novel carbohydrate microarray the team were able to identify the precise sugars to which the parasite protein binds. Following this the team used a combination of NMR spectroscopy and cellular studies to characterise the behaviour and interactions of the parasite protein and host cell sugars. This means that the team have a more detailed picture than ever before of exactly how the parasite recognises and attacks host cells in the body. Professor Steve Matthews from Imperial College London’s Division of Molecular Biosciences, one of the paper’s authors, explains the significance of the research, saying: “Understanding the fundamental, atomic-level detail of how diseases like toxoplasmosis pick out and invade host cells in the human body is vital if we want to fight these diseases effectively. “Now that we understand that it’s a key interaction between a protein on the parasite’s surface and sugars on the human cell which lead to the cell’s invasion, there is potential to develop therapeutics that are targeted at disrupting this mechanism, therefore thwarting infection.”Toxoplasma gondii, the parasite that causes toxoplasmosis, is one of the world’s most common parasites. Around a quarter to half of the world’s population is thought to be infected, and around 1% of people in the UK catch toxoplasmosis each year. In the majority of cases, those affected don’t have any symptoms. But for those with weakened immune systems, and unborn babies, toxoplasmosis can cause very serious health problems.Reference: ‘Atomic resolution insight into host cell recognition by Toxoplasma gondii’, The EMBO Journal, 10 May 2007. Note: This story has been adapted from a news release issued by Imperial College London.
So another factor is needed to justify the expansion of the mutated clone.Toxoplasma could be one of a restricted group of germs capable of jamming some crucial point of the complex immune reaction (involving T-cells, macrophages, complex cytokine interactions) evoked by protozoa and other 'fastidious' germs.Helicobacter pylori and mycoplasmas might be in the number.
Case ReportA 45-year-old man was referred to our hospital for evaluation of leukocytosis in January 1985. Three months previously, he had reported tarry stools.A peptic ulcer was diagnosed and treated with intravenous cimetidine. At that time, leukocytosis, thrombocytosis, and anemia were detected. A bone marrow aspirate showed marked myeloid hyperplasia. Cytogenetic analysis revealed Ph-positive cells in the bone marrow, and a diagnosis of CML was made. During the next month the leukocyte count decreased to 14,400 per cubic millimeter, but it subsequently gradually increased to 31,800 per cubic millimeter before admission to our hospital. Physical examination on admission revealed anemia and mild hepatosplenomegaly. A complete blood count again showed leukocytosis and thrombocytosis. The neutrophil alkaline phosphatase score was 94 (normal range, 170 to 335). Plasma histamine and prostaglandin E concentrations were within the normal range.An endoscopic examination revealed an ulcer scar in the duodenal bulb. Regular follow-up, without chemotherapy, was planned for the patient. In February 1985, the hepatosplenomegaly disappeared. The leukocyte count and platelet count returned to normal in April 1985. As of January 30, 1996, the patient had been well, without any signs of recurrence, for 11 years. Blood counts since June 30, 1994, have been normal....
CML TreatmentTreatment options and outcome from treatment have improved significantly over the years. Year Treatment Survival (months) 1920-1950 Splenic irradiation 28 1950-1960 Busulfan 35-45 1960-1970 Hydroxyurea 48-67 1970-1980 1st Allogeneic Stem Cell Transplant for CML 50-60% CURE 1980-1990 IFNa (Interferon alpha) 55-89 1990-2001 IFNa + Cytosine arabinoside (Ara-C) Recent studies showing significant improvement over IFNa alone 1995-2001 STI-571 >90% 5yrs survival (2007)Table 1. Treatment options and survival. (JAMA, August 22/29 p. 896)from: http://intmedweb.wfubmc.edu/grand_rounds/2001/myeloid.html