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Sustaining of RHD polymorphism in human population by selectin in favour of heterozygotes
Pokorný, Daniel ; Flegr, Jaroslav (advisor) ; Kaňková, Šárka (referee)
RhD polymorphism is an evolutionary enigma since the very discovery. Theoretically, the RhD- allele carriers should be eliminated through the negative selection against RhD positive children born to RhD negative mothers. The aim of this diploma thesis was to find out whether RhD positive heterozygous genotype is associated with the reduction of latent toxoplasmosis negative effects or even associated with improved psychomotor performances, memory or higher self-confidence, intuition and cognitive performances scores. Second of all, the aim of this thesis was to find out if RhD negative homozygotes exhibit worsened performances in the abovementioned characteristics and, consequently, see whether RhD polymorphism origin and maintenance could be achieved through the heterozygote advantage. General linear models that included listed variables, RhD genotypes and phenotypes, information about toxoplasma-infection status and age as a covariate were performed. Heterozygote Advantage hypothesis was supported in operational memory models and in case of women also in psychomotor performances models. On the other hand, models of short-term memory, self-confidence, intuition and cognitive performances scores did not support the formulated hypothesis. Keywords RhD polymorphism, selection favouring heterozygotes,...
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Influence of latent toxoplasmosis on human fertility
Hlaváčová, Jana ; Kaňková, Šárka (advisor) ; Calda, Pavel (referee)
Toxoplasma gondii is one of the most widespread parasitic protozoa in humans in developed countries. It has a wide range of hosts including various warm-blooded animals and humans. Recent studies suggest that it could influence the fertility of humans. The aim of this work was to find out, what is the prevalence of toxoplasmosis in groups of women and men with fertility problems and whether Toxoplasma gondii has an effect on specific fertility parameters. In women, Significant positive correlation between toxoplasmosis and the percentage of oocytes in the follicles was found among women. Group of men with semen pathology diagnosis revealed a statistically significant negative association between toxoplasmosis and the percentage of morphologically normal sperm. It seems that latent toxoplasmosis in men can also worsen the negative effect of tobacco smoking on fertility. The impairment of fertility in men could be the result of the manipulation activity of Toxoplasma gondii, which leads to more frequent sexual intercourse due to decreased ability to conceive. This could increase the likelihood of sexual transmission, which is currently suggested as one of the possible ways of transmission of toxoplasmosis.
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The effect of parental age on the offspring's life
Poneszová, Viktorie ; Kuba, Radim (advisor) ; Kaňková, Šárka (referee)
This bachelor thesis concentrates on parenthood at a suboptimal age and the impact it may have on the life of the offspring. The study was written with a focus on the Europoid ethnicity. Nowadays there has been a significant increase in the age of parents at the birth of the first child, but early motherhood and fatherhood are both numerous too. Parenting at a non-optimal age can significantly affect the child's life, for example, its health or cognitive functions. At first, the literature of relevant topics was gathered, studied in detail, and the results of individual studies were summed up in the form of objective literary research. This study summarize the positives and negatives associated with the non- optimal age for establishing a family and the effect of parental age on the offspring. This research will be appreciated mainly by those who are interested in the subject for personal or study reasons, it can also form the theoretical basis for following research. Finally, this study expands awareness of how strong is the influence of parental age on the offspring, even with a brief reflection on the ideal age of family establishing.
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Options of the sexual transmission of toxoplasmosis
Forejtková, Zita ; Kaňková, Šárka (advisor) ; Kodym, Petr (referee)
Toxoplasmosis is a disease caused by coccidia Toxoplasma gondii. This disease occurs in humans and warm-blooded animals throughout the world and is matter of great economic and medical importance. This bachelor thesis contains a summary of current information on the possibility of sexual transmission of T. gondii. Sexual transmission was confirmed in warm- blooded animals. A higher prevalence of toxoplasmosis was found in people who are infected with some venereal diseases. There is another indirect evidence supporting the hypothesis of sexual transmission of T. gondii. This route of transmission could play an important role, especially during pregnancy and to people with impaired immune responses.
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Factors influencing weight gain in pregnncy
Vodrážková, Nicole ; Kaňková, Šárka (advisor) ; Horníková, Daniela (referee)
In this bachelor thesis I described different factors influencing weight gain in each trimester of pregnancy. There are factors influenced by a lifestyle, such as diet, physical activity, smoking, and BMI before pregnancy. There are also factors which are given individual dispositions, changes in metabolism and hormonal status of the organism. On this basis, this thesis deals with the consequences, that has excessive or insufficient weight gain in pregnancy for the mother and her fetus.
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The Influence of Parasites on the Sex Ratio
Benešová, Jana ; Kaňková, Šárka (advisor) ; Votýpka, Jan (referee)
Changes of the sex ratio in favour of one sex or the other may be caused by various factors. These changes have proximate causes, while some may even have ultimate causes. One of the factors affecting the sex ratio is parasitisation. The parasite manipulates the sex of the offspring of their hosts intentionally, or as a so-called side effect of its actions. The major role in deviated formation of the sex ratio is often endocrine and immune systems. Many studies are also concur with the Trivers-Willard hypothesis on a lower sexual index in the poor condition of females. Key words: sex ratio, parasite, Trivers-Willard hypothesis, manipulation hypothesis, sex hormones, immunity
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Factors influencing weight gain in pregnancy
Vodrážková, Nicole ; Kaňková, Šárka (advisor) ; Flegr, Jaroslav (referee)
In this bachelor thesis I described different factors influencing weight gain in each trimester of pregnancy. There are factors influenced by a lifestyle, such as diet, physical activity, smoking, and BMI before pregnancy. There are also factors which are given individual dispositions, changes in metabolism and hormonal status of the organism. On this basis, this thesis deals with the consequences, that has excessive or insufficient weight gain in pregnancy for the mother and her fetus.
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Toxoplasma and Host's Reproductive Function
Hlaváčová, Jana ; Kaňková, Šárka (advisor) ; Kodym, Petr (referee)
Toxoplasma gondii (Apicomplexa) is probably one of the most common human parasite in developed countries. It has a wide range of hosts including a variety of warm-blooded animals as well as humans. In this bachelor thesis you can find review of literature focusing on an influence of T. gondii on host's reproductive functions. Toxoplasmosis is accompanied by hormonal changes which may be one reason for the negative effect on host's fertility. Throughout the thesis are mentioned immunosuppression and reduced quality control of embryos associated with T. gondii. Both of these phenomena probably affect pregnancy, prenatal and postnatal development of the offsprings of mothers with latent toxoplasmosis. And these also play a role in shifting of sex ratio in infected hosts.
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Effect of latent toxoplasmosis on the thyroid function during pregnancy
Procházková, Lucie ; Kaňková, Šárka (advisor) ; Springer, Drahomíra (referee)
While several past studies dealt with the effects of latent toxoplasmosis on the function of the thyroid gland and on the pregnancy separately, the former one with varied results, this work combines the two areas together with goals to determine whether the latent toxoplasmosis affects levels of antibodies against thyroid peroxidase (TPO) in the 1st trimester of pregnancy, to analyze the effect of toxoplasmosis on the levels of the thyrotrophic hormone and to learn whether the interactions between latent toxoplasmosis and autoimmune thyropathies affect conception, foetal development, length of pregnancy and mode of delivery in childbirth. The work follows on the recent years' discoveries of our laboratory that showed the latent toxoplasmosis to affect both the course of pregnancy and the prenatal development of a child. It also takes up directly on a screening of autoimmune thyropathies in pregnant women conducted in years 2006 to 2009 in General University Hospital. The retrospective study comprised of 1434 pregnant women who underwent serological examination as a part of the 1st trimester screening and whose serum was subsequently examined for toxoplasmosis. The data set obtained from medical databases contained results of serological screening of the mothers, ultrasound examination of the...
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Influence of latent toxoplasmosis on sex ratio and pregnancy progression - search for proximate cause
Kaňková, Šárka ; Flegr, Jaroslav (advisor) ; Votýpka, Jan (referee) ; Calda, Pavel (referee)
The boy-to-girl ratio at birth (secondary sex ratio) is around 1.06 in most populations. The sex ratio may be influenced by many factors, such as stress and immunosuppression, age of parents, parity and sex of preceding siblings. The most common human protozoan parasite in developed countries, Toxoplasma gondii (prevalence 20% - 80%), is known to change the behaviour of its intermediate hosts, thereby increasing the probability of transmission to its definitive host (the cat) by predation. The results of our retrospective cohort study suggest that the presence of Toxoplasma gondii, can influence the secondary sex ratio in humans. Depending on the antibody concentration, the probability of the birth of a boy can increase up to a value of 0.72, which means that for every 260 boys born, 100 girls are born to women with the highest concentration of anti-Toxoplasma antibodies. In accordance with results on human subjects, laboratory mice with toxoplasmosis produced a higher sex ratio than controls, in the early phase of latent infection. Our further results showed that mice in the early phase of latent infection exhibited temporarily increased production of interleukin (IL)-12 and decreased production of IL-10. The mice showed decreased production of IL-2 and nitric oxide and decreased proliferation...
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