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Toxoplasma gondii & Human Phenotype

Compendium of Known Effects and Ongoing Research

growth

Risky business: linking Toxoplasma gondii infection and entrepreneurship behaviours across individuals and countries

August 31, 2018
Johnson, S. K., Fitza, M. A. , Lerner, D. A., Calhoun, D. M., Beldon, M. A. , Chan, E. T., Johnson, P. T. J.
Proceedings of the Royal Society B-Biological Sciences, 2018; 285
Click for abstract
Disciplines such as business and economics often rely on the assumption of rationality when explaining complex human behaviours. However, growing evidence suggests that behaviour may concurrently be influenced by infectious microorganisms. The protozoan Toxoplasma gondii infects an estimated 2 billion people worldwide and has been linked to behavioural alterations in humans and other vertebrates. Here we integrate primary data from college students and business professionals with national-level information on cultural attitudes towards business to test the hypothesis that T. gondii infection influences individual- as well as societal-scale entrepreneurship activities. Using a saliva-based assay, we found that students (n = 1495) who tested IgG positive for T. gondii exposure were 1.4 x more likely to major in business and 1.7x more likely to have an emphasis in 'management and entrepreneurship' over other business-related emphases. Among professionals attending entrepreneurship events, T. gondii-positive individuals were 1.8x more likely to have started their own business compared with other attendees (n = 197). Finally, after synthesizing and combining country-level databases on T. gondii infection from the past 25 years with the Global Entrepreneurship Monitor of entrepreneurial activity, we found that infection prevalence was a consistent, positive predictor of entrepreneurial activity and intentions at the national scale, regardless of whether previously identified economic covariati.ss were included. Nations with higher infection also had a lower fraction of respondents citing 'fear of failure' in inhibiting new business ventures. While correlational, these results highlight the linkage between parasitic infection and complex human behaviours, including those relevant to business, entrepreneurship and economic productivity.

Tagged: animal behavior, attraction, disease, ecology, emerging infectious disease, entrepreneurship, gondii infection, growth, human behaviour, humans, microbiome, parasite manipulation, Schizophrenia, society, strategic entrepreneurship, testosterone, Toxoplasma gondii

Behavior

Low titer of antibody against Toxoplasma gondii may be related to resistant to cancer

October 6, 2015
Seyedeh, M. S., Nahid, S., Nahid, M., Shima, D. P., Morteza, Y., Hossein, Y. D.
Journal of Cancer Research and Therapeutics 2015; 11: 305-307.
Click for abstract
Context: Toxoplasma gondii is a protozoan parasite with a world-wide distribution. However, the majority of infected cases remain symptomless. There are raising scientific evidences indicating that parasitic infections induce antitumor activity against certain types of cancers. The inhibitory effect of T. gondii on cancer growth has also been shown in cell culture and mouse model. Aims: Considering the anti-tumor effect of this parasite, in this study the relationship between low titer of antibodies against T. gondii and resistant to cancers has been investigated. Subjects and Methods: In two separate experiments, anti T. gondii antibody was estimated in 150 patients with cancer and 120 normal people. Statistical Analysis Used: Chi-square test was used for data analysis. Results: The frequency of low titer antibody against Toxoplasma gondii in cancer patients was significantly higher than the frequency of low-titer antibody against this parasite in normal people. Conclusions: Exposure to T. gondii may be related to resistance to cancer.

Tagged: antibody, cancer, cells, expression, growth, infected mice, injection, lewis lung-carcinoma, lysate antigen, organisms, parasites, Toxoplasma gondii, trypanosoma-cruzi

Physical health

The effect of artemether on psychotic symptoms and cognitive impairment in first-episode, antipsychotic drug-naive persons with schizophrenia seropositive to Toxoplasma gondii

October 10, 2014
Wang, H. L., Xiang, Y. T., Li, Q. Y., Wang, X. P., Liu, Z. C., Hao, S. S., Liu, X., Liu, L. L., Wang, G. H., Wang, D. G., Zhang, P. A., Bao, A. Y., Chiu, H. F. K., Ungvari, G. S., Lai, K. Y. C., Buchanan, R. W.
Journal of Psychiatric Research 2014; 53: 119-124
Click for abstract
The objective was to evaluate the efficacy and safety of add-on artemether in first-episode, untreated people with schizophrenia, who were Toxoplasma gondii seropositive, and explore the change in T gondii antibodies during treatment. In this eight-week, double-blind, randomized, placebo-controlled trial, 100 T. gondii seropositive participants with schizophrenia were randomized to either the artemether or placebo group. Participants in the artemether group received 80 mg artemether once per day during the second week (days 8-14) and the fourth week (days 22-28). Participants in the placebo group received identical looking placebo capsules. Psychopathology, adverse side effects and cognitive function were measured using standardized instruments. The group x time interaction effects for the scores of the Positive and Negative Syndrome Scale (PANSS) subscales and performances on all cognitive components were not significant, only the main effect of group was significant. Compared to the placebo group, artemether group participants showed significantly greater reduction in the PANSS negative symptom scale (F-(1,F-46) = 4.7, p = 0.03) and the Clinical Global Impressions Scale (F-(1,F-96) = 6.2, p = 0.01) scores, but there were no significant differences in the PANSS positive symptom and general psychopathology scales (p > 0.05). There were also no significant differences between the two groups in performance on any of the Brief Assessment of Cognition in Schizophrenia (BACS) cognitive domains. The artemether risperidone combination is safe and well tolerated, but artemether as an adjunct to risperidone does not appear to alleviate cognitive deficits of schizophrenia. Trial Registration Chinese Clinical Trial Register (ChiCTR) TRC-13003145 (C) 2014 Elsevier Ltd. All rights reserved.

Tagged: acetylcholine-receptors, antibodies, artemether, artemisinin, cognition, derivatives, exposure, growth, inhibition, metaanalysis, progressive brain changes, psychopathology, rodents, Schizophrenia, Toxoplasma gondii

Mental health

Autism spectrum disorders may be due to cerebral toxoplasmosis associated with chronic neuroinflammation causing persistent hypercytokinemia that resulted in an increased lipid peroxidation, oxidative stress, and depressed metabolism of endogenous and exogenous substances

October 19, 2010
Prandota J.
Research in Autism Spectrum Disorders 2010; 4: 119-155
Click for abstract
Worldwide, approximately 2 billion people are chronically infected with Toxoplasma gondii with largely yet unknown consequences. Patients with autism spectrum disorders (ASD) similarly as mice with chronic toxoplasmosis have persistent neuroinflammation, hypercytokinemia with hypermetabolism associated with enhanced lipid peroxidation, and extreme changes in the weight resulting in obesity or wasting. Data presented in this review suggest that environmental triggering factors such as pregnancy, viral/bacterial infections, vaccinations, medications, and other substances caused reactivation of latent cerebral toxoplasmosis because of changes in intensity of latent central nervous system T. gondii infection/inflammation and finally resulted in development of ASD. Examples of such environmental factors together with their respective biomarker abnormalities are: pregnancy (increased NO, IL-1 beta, TNF-alpha, IL-6, IL-10, prolactin: decreased IFN-gamma, IL-12), neuroborreliosis (increased IL-1 beta, sIL-1R2, TNF-alpha, IFN-gamma, IL-6, IL-10, IL-12, IL-18, transforming growth factor-beta 1 (TGF-beta 1)), vital infections (increased IL-1 beta, IL-6, IL-8, TNF-alpha, IFN-gamma/alpha/beta,TGF-beta 1), thimerosal (increased IL-5, IL-13; decreased IFN-gamma,TNF-alpha,IL-6, IL-12p70, NOS), and valproic acid (increased NO, reactive oxygen species; decreased TNF-alpha, IL-6, IFN-gamma). The imbalances in pro- and antiinflammatory processes could markedly hinder [lost defense mechanisms important for immune control of the parasite, such as the production of NO, cytokines, and reactive oxygen/nitrogen species, tryptophan degradation by indoleamine 2,3-dioxygenase and/or tryptophan 2,3-dioxygenase, limitation of the availability of intracellular iron to T gondii, and the mechanisms mediated by an IFN-gamma responsive gene family. These fluctuations could result in a recurrent profuse multiplication of T. gondii in the brain associated with persistent neuroinflammation, chronic overproduction of pro- and antiinflammatory cytokines, and NO causing increased oxidative stress, and significantly depressed activity of several enzymes including cytochrome P450 monooxygenase family responsible for metabolism of physiological substrates and xenobiotics, such as steroids, fatty acids, prostaglandins, drugs, pollutants, and carcinogens, finally leading to development of ASD. This reasoning may be supported by such abnormal metabolic events as: (1) patients with ASD have significantly decreased melatonin levels caused by marked deficit in acetylserotonin methyltransferase activity, possibly resulting from maternal and/or fetal/postnatal overproduction of NO, characteristic for this clinical entity; (2) thimerosal inhibited both insulin-like growth factor-1- and dopamine-stimulated methylation reactions, and depressed methionine synthase activity, the metabolic events important for promoting normal neurodevelopment; (3) valproic acid, a strong histone deacetylase inhibitor, have potent anti-T. gondii activity. Thus, patients with ASD should be tested for T. gondii infection. (C) 2009 Elsevier Ltd. All rights reserved

Tagged: abnormalities, abnormality, acid, acids, aktivity, autism, autistic spectrum disorders, availability, beta, biomarker, brain, cell-mediated-immunity, central-nervous-system, cerebral, Cerebral toxoplasmosis, change, changes, chronic, chronic neuroinflammation, chronic toxoplasmosis, clinical, congenital cytomegalovirus-infection, consequence, consequences, control, could, cytochrome, cytochrome p450, cytokine, cytokines, data, defense, defense-mechanisms, deficit, degradation, depressed enzyme activities, development, disorder, disorders, drug, drugs, environmental, environmental factors, enzyme, enzymes, event, events, example, families, family, fluctuation, fluctuations, gene, gene families, gene family, gondii, gondii infection, growth, growth-factor-beta, hepatic drug-metabolism, herpes-simplex-virus, histone, histone deacetylase, hypercytokinemia, hypermetabolic state, il-1, il-10, il-12, il-13, il-6, immune, immune irregularities, important, infection, infections, inhibitor, insulin-like, intensity, interferon-inducing agents, intracellular, iron, latent, level, limitation, lipid, lipid-peroxidation, maternal, mechanism, mechanisms, medication, melatonin, metabolism, methionine, methylation, methyltransferase, methyltransferase aktivity, mice, multiplication, nervous, nervous system, neurodevelopment, nf-kappa-b, nitric oxide, nitric-oxide synthase, obesity, or, overproduction, oxidative stress, oxygen, p-450-dependent monooxygenase systems, Parasite, patient, patients, people, persistent, pregnancies, pregnancy, proces, prolactin, prostaglandins, reaction, reactivation, review, species, spectrum, spectrum disorders, spektra, steroids, stress, substrate, systém, t, tgf-beta, tnf-alpha, Toxoplasma, Toxoplasma gondii, toxoplasmosis, tryptophan, tumor-necrosis-factor, vaccination, vital, weight, xenobiotics

Mental health

Topics

  • Behavior 105
  • Cognitive functions 64
  • Mental health 439
  • Morphology 6
  • Motor functions 10
  • Personality 36
  • Physical health 134
  • Reproduction 36
  • Reviews 40
  • Sensory functions 3
  • Uncategorized 2

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Recent articles

  • Mortality Patterns of Toxoplasmosis and Its Comorbidities in Tanzania: A 10-Year Retrospective Hospital-Based Survey February 6, 2020
  • The role of latent toxoplasmosis in the aetiopathogenesis of schizophrenia–the risk factor or an indication of a contact with cat? February 6, 2020
  • The Association between Toxoplasma gondii Infection and Risk of Parkinson’s Disease: A Systematic Review and Meta-Analysis February 6, 2020

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