• About
  • Keywords

Toxoplasma gondii & Human Phenotype

Compendium of Known Effects and Ongoing Research

testosterone concentration

The relation of cortisol and sex hormone levels to results of psychological, performance, IQ and memory tests in military men and women

January 9, 2012
Flegr, J., Hampl, R., Černochová, D., Preiss, M., Bičíkova, M., Sieger, L., Příplatová, L., Kaňková, S., Klose, J.
Neuroendocrinology Letters 2012; 33: 224-235
Click for abstract
BACKGROUND: Cortisol, along with other hormones of hypothalamo-pituitary-adrenal axis, belongs to one of the main factors influencing psychological and pathognomic factors, intelligence, and memory. METHODS: The aim of our study was to review a large battery of psychological, performance, IQ and memory tests as to their relation with cortisol, testosterone and estrogen levels in groups of 100 men and 93 women who attended the Central Military Hospital in Prague for regular entrance psychological examinations for military personnel. RESULTS: In men, we detected positive correlations between cortisol and emotional lability, and negative correlations with impulsivity, while in women hypochondria and psychopathology were negatively correlated, and aggression measured with the Meili selective memory test had a positive relation to cortisol level. Testosterone correlated positively with emotional liability and negatively with impulsivity in men, and negatively with hypochondria and psychasteny, indirect aggression, irritability and paranoia in women. Estradiol correlated positively with psychopathology in men, and negatively with phobia. It was positively correlated with negativism in women. No clear correlation was observed between the concentration of steroid hormones and psychomotor performance or intelligence. CONCLUSIONS: Concentrations of steroid hormones correlate with results of several psychological tests, the sign and magnitude of these correlations, however, very often differ in military men and women.

Tagged: aggression, bdi, behavior, cortisol, dominance, estrogen, gender differences, hypothesis, intelligence, meili test, memory, miller 2009, n-70, od-1, otis test, personality, personality tests, psychology, questionnaire, responses, stress, supports, testosterone, testosterone concentration, topp, toxoplasmosis, wmt

Cognitive functionsPersonality

Potential immunomodulatory effects of latent toxoplasmosis in humans

January 9, 2011
Flegr, J., Striz, I.
Bmc Infectious Diseases 2011; 11: Artn 274 10.1186/1471-2334-11-274
Click for abstract
Background: About 30% of the population worldwide are infected with the protozoan parasite Toxoplasma gondii. Latent toxoplasmosis has many specific behavioral and physiological effects on the human organism. Modified reactivity of the immune system has been suggested to play a key role in many of these effects. For example, the immunosuppression hypothesis explains the higher probability of the birth of male offspring observed in Toxoplasma-positive humans and mice by the protection of the (more immunogenic) male embryos against abortion. Methods: Here we searched for indices of immunosuppression in Toxoplasma-positive subjects by comparing clinical records of immunology outpatients. Results: Our cohort study showed that the male patients with latent toxoplasmosis had decreased and the Toxoplasma-positive women had increased leukocyte, NK-cell and monocyte counts in comparison with controls. The B-cell counts were reduced in both Toxoplasma-positive men and women. The difference between Toxoplasma-positive and Toxoplasma-negative subjects diminished with the decline of the specific Toxoplasma antibody titre (a proxy for the length of infection), which is consistent with the observed decreasing strength of the effect of latent toxoplasmosis on human reproduction. The prevalence of toxoplasmosis in 128 male patients was unusually low (10.9%) which contrasted with normal prevalence in 312 female patients (23.7%) and in general population Prague (20-30%). Conclusions: Latent toxoplasmosis has immunomodulatory effects in human and probably protects men against some classes of immunopathological diseases. The main limitation of the present study was the absence of the data on the immunoreactivity of immune cells subpopulations. Therefore further studies are needed to search for indices of immunosuppression in human using more specific markers.

Tagged: antibodies, behavioral-changes, communication, gender differences, gondii, hypothesis, mice, sex ratio, testosterone concentration, traffic accidents

Physical health

Potential solutions to problems posed by the offspring sex ratios of people with parasitic and viral infections

January 8, 2010
James, W. H.
Folia Parasitologica 2010; 57:114-120
Click for abstract
I have hypothesized that mammalian offspring sex ratios (proportions male at birth) are partially controlled by the hormone levels of both parents around the time of conception. Recently data have been published (privately) which impugn suggestions of mine (based on that hypothesis) relating to the offspring sex ratios of people who are carriers of hepatitis B virus; and (publicly) to hormone profiles of women who are infected with the protozoan parasite Toxoplasma gondii. Here these data are reviewed in the light of data on offspring sex ratios of people infected with hepatitis C, and cytomegalovirus and T gondii; and of mice with T gondii and the trichostrongyline nematode Heligmosomoides polygyrus. Three proposals are made viz: I. Women infected with T gondii may have high oestrogen levels. This would potentially explain reports of their high offspring sex ratios, long gestations and (perhaps) behavioural traits. 2. Some of these infective organisms may 'prefer' a particular endocrine environment in their host (in the sense that it facilitates replication or transmission or both). 3. Some of these organisms apparently cause changes in that endocrine environment as a consequence of their presence. If both the latter two proposals were correct, it could explain recent puzzling data on the offspring sex ratios of hepatitis B carriers. And if this solution turns out to be correct, it would suggest new endocrine means of combating hepatitis B infection.

Tagged: 4th digit ratio, chronic murine toxoplasmosis, cytomegalovirus cmv, gene-expression, heligmosomoides polygyrus, hepatitis b virus hbv, hepatitis c virus hcv, hepatitis-b-virus, hepatocellular-carcinoma, latent asymptomatic toxoplasmosis, ovarian dysfunction, parental hormone-levels, serum testosterone, sex ratio at birth, testosterone concentration, Toxoplasma gondii

Reproduction

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

Archives

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

Recent Comments

    Meta

    • Log in
    • Entries feed
    • Comments feed
    • WordPress.org

    Copyright © 2023 Toxoplasma gondii & Human Phenotype.

    ToxoBehavior WordPress Theme by Jelena Braum