"Genetic approaches to sexual orientation"

Abstract

Sexual Orientation is defined as the choice of sex of the sexual partner. 5-10% of people are classified as homosexual or better not heterosexual. The sex of an organism ♀ XX or ♂ XY is determined at birth by the presence of the Y chromosome which determines the sex of the individual and refers to its biological characteristics, dividing individuals into male or female according to the primary characteristics of sex, such as the sex chromosomes, the existence of hormones and the external and internal anatomical features of a person. Gender is defined as a person's social role, with the behaviors, activities, and traits that society deems appropriate for boys-girls or men-women, and affects how individuals within a social group interact, feel, and experience themselves in relation to the rest of the group and while the definition of the sex is the same in all societies, the definition of gender differs significantly depending on the country, society, and religion.

Hormonal factors influence sexual orientation due to the early onset of the action of testosterone, which at the same time organizes sex differences in the brain and is thus also responsible for a person's behavior, thus explaining only part of the diversity presented by sexual orientation and only part of homosexual cases both in humans but also in fish, birds, amphibians, and other mammals such as sheep where 8% of male sheep are born homosexual.

There are indications that there is a clear heredity for the same-sex sexual preference, with more than one hereditary factor being responsible and while no single gene has yet been identified, multiple markers in regions of chromosomes X (Xq28), 7 (7q36), 8 (8p12) and 10 (10q26), as well as epigenetic factors such as the asymmetric inactivation of the X chromosome have been supposed, each being able to explain only part of the diversity. The older brother effect or fraternal birth order (FBO)effect, explains at most 30% of gay men's cases.

Current data indicate that there are biological mechanisms such as hormonal, genetic, and immunological but they explain only a part of the cases and it seems clear that sexual orientation and homosexuality is a complex phenomenon where additional studies and further research will be needed to define a unified theory of its exact causes, while there are no indications that sexual orientation is affected or due to social or environmental factors.

Due to the widespread integration of gays, lesbians, etc. into society, the ever-increasing acceptance of same-sex relationships seems likely to lead to the existence of a "post-gay" culture in the future. As LGBTQ (Lesbian Gay Bisexual Transgender Queer) people gradually gain full legal and social approval and equality, the levels of acceptance of their sexual orientation will in the future not be separated as a different identity, different social status, or something different at all.

EFTAXIA Sofia

"Stem cells and their role in the treatment of psychiatric diseases"

Abstract

Psychiatric illnesses burden the health system significantly, accounting for 7.1% of the total burden of illnesses worldwide. Despite the great advances that have been made in recent decades, our knowledge of the pathophysiology of many common psychiatric disorders remains limited. Firstly, because they represent a malfunction in the less understood organ of the human body: the brain, and secondly, because of the great complexity suggested by our limited understanding of the genetic basis of mental illness. This dissertation gathers the latest data on the application of stem cells in the treatment of psychiatric disorders.

In recent years, many studies have focused on immune abnormalities and the reduction of neurotrophic factors that characterize the pathophysiology of psychiatric disorders. It is known that MSCs have the ability to promote neurogenesis and the survival and differentiation of nerve cells through the expression of neurotrophic factors, e.g. of BDNF, NGF, and IGF. In particular, intra-hippocampal implantation of MSCs enhances hippocampal neurogenesis and does not affect the behavioral function of rats. In addition, ever-increasing evidence suggests that the management of NSCs has a significant impact on most psychiatric disorders. Current data suggest that both neurogenesis and oligodendrogenesis may be regulated in psychiatric illnesses, possibly playing an essential role in their pathogenesis. Finally, phenotypes of various psychiatric disorders can be detected in hiPSC-derived neurons and the first models of hiPSC-based psychiatric illnesses are already reported.

LAMPROPOULOU Xristina

"Combination of metronomic chemotherapy and immunotherapy - Theoretical and experimental approach"

Abstract

Oncology has benefited from an increasingly growing number of groundbreaking innovations over the last decade. Immune checkpoint inhibitors, anti-angiogenics and targeted therapies have already entered the clinic with various level of success. On the other hand, conventional cytotoxic chemotherapy appears to have reached a plateau in efficacy for most major solid cancers. Alternative dosing schedules such as metronomic regimens, based upon the repeated and regular administration of low doses of chemotherapeutic drugs, have emerged as possible strategies to improve response rates while reducing toxicities. The recent changes in paradigm in the way we theorize cancer biology and evolution, metastatic spreading and tumor ecology, alongside the recent advances in the field of immunotherapy, have considerably strengthened the interest for these alternative approaches. The evidence of the multi-targeted nature of Metronomic chemotherapy and the possible combination with repositioned drugs, targeted therapies and immunotherapy have paved the way for the expansion of personalized precision chemotherapy. Furthermore, cancer immunotherapies are rapidly changing traditional treatment paradigms and expanding the therapeutic landscape for cancer patients. However, despite the current success of these therapies, not all patients respond to immunotherapy and even those that do, often experience toxicities.

A promising approach is to block the immunosuppressive mechanisms, such as CTLA-4 and the PD-1/PD-L1 axis, to augment the function of endogenous antitumor T cells, which can deliver a robust and effective clinical response. One of the main objectives of Metronomic chemotherapy is to tilt the immunological balance from immunosuppression to immunostimulation and so Metronomic chemotherapy has already been combined with several types of immunotherapy, with variant responses. Nevertheless, the position of Metronomic therapy alone or combined with immunotherapy in cancer fight, should to be further explored.

ILIA Helen