Reinterpretation of mouse thyroid changes under space conditions: the contribution of confinement to damage

Long-term space missions' effects on the human organism: what we do know and what requires further research

Space has always fascinated people. Many years have passed since the first spaceflight, and in addition to the enormous technological progress, the level of understanding of human physiology in space is also increasing. The presented paper aims to summarize the recent research findings on the influence of the space environment (microgravity, pressure differences, cosmic radiation, etc.) on the human body systems during short-term and long-term space missions. The review also presents the biggest challenges and problems that must be solved in order to extend safely the time of human stay in space. In the era of increasing engineering capabilities, plans to colonize other planets, and the growing interest in commercial space flights, the most topical issues of modern medicine seems to be understanding the effects of long-term stay in space, and finding solutions to minimize the harmful effects of the space environment on the human body.

Possible Stress-Neuroendocrine System-Psychological Symptoms Relationship in Pregnant Women during the COVID-19 Pandemic

The COVID-19 pandemic induced long-term damages that weigh on the national health systems of various countries in terms of support and care. This review aimed to highlight the mental health impact of the COVID-19 pandemic in pregnant women. We first report data on the immune system physiopathology and the main viral infections in pregnancy, including COVID-19. Then, the attention is focused on the main factors that affect the mental health of pregnant women during the COVID-19 pandemic, such as (1) the fear of being infected and transmitting the infection to the fetus, (2) the cancellation of checkups and pre-child courses, and (3) confinement and the inability to have close friends or a partner at the time of delivery or in the first days after delivery, as well as family tensions. Because of all this, pregnant women find themselves in a stressful condition independent of the pregnancy, and thus experience anxiety, depression, insomnia, hostility, delirium, and an alteration of the mother-baby relationship. Several studies have shown an involvement of the hypothalamic-pituitary-adrenal axis and the hypothalamic-pituitary-thyroid axis in response to the pandemic. We propose a possible involvement of the neuroendocrine system as a mediator of the psychological symptoms of pregnant women induced by COVID-19-related stress.

Impact of Gravity on Thyroid Cells

Physical and mental health requires a correct functioning of the thyroid gland, which controls cardiovascular, musculoskeletal, nervous, and immune systems, and affects behavior and cognitive functions. Microgravity, as occurs during space missions, induces morphological and functional changes within the thyroid gland. Here, we review relevant experiments exposing cell cultures (normal and cancer thyroid cells) to simulated and real microgravity, as well as wild-type and transgenic mice to hypergravity and spaceflight conditions. Well-known mechanisms of damage are presented and new ones, such as changes of gene expression for extracellular matrix and cytoskeleton proteins, thyrocyte phenotype, sensitivity of thyrocytes to thyrotropin due to thyrotropin receptor modification, parafollicular cells and calcitonin production, sphingomyelin metabolism, and the expression and movement of cancer molecules from thyrocytes to colloids are highlighted. The identification of new mechanisms of thyroid injury is essential for the development of countermeasures, both on the ground and in space, against thyroid cancer. We also address the question whether normal and cancer cells show a different sensitivity concerning changes of environmental conditions.