Steroid Conjugates and Their Physiological Role.

While there are hundreds of synthetic steroids conjugates with acids, sugars, proteins and other molecules, only two types of conjugates occur in living organisms, namely sulfates and glucuronides. Steroid glucuronidation in the human liver is the main mechanism controlling the levels and biological activity of unconjugated hormones, and glucuronides are their main excretion products. This process is generally irreversible.

Endocrine risk factors for COVID-19 in context of aging.

Aged people are the most susceptible group to COVID-19 infection. Immunosenescence characterized by impairment of immune function with inflamm-aging contributes to pathophysiological alterations, among which endocrine and metabolic diseases are not exception. Diabetes, obesity along with impairment of disorders of thyroid functions are the most frequent ones, the common feature of which is failure of immune system including autoimmune processes.

Vitamin D and new insights into pathophysiology of type 2 diabetes.

Deficiency in vitamin D plays a role in the onset and development of insulin resistance (IR) and type 2 diabetes (T2DM). A normal level of vitamin D is able to reduce low grade inflammation, which is a major process in inducing insulin resistance. It is also engaged in maintaining low resting levels of reactive species and radicals, normal Ca signaling, a low expression of pro-inflammatory cytokines but increased formation of anti-inflammatory cytokines.

Determination of Intraprostatic and Intratesticular Androgens.

Androgens represent the main hormones responsible for maintaining hormonal balance and function in the prostate and testis. As they are involved in prostate and testicular carcinogenesis, more detailed information of their active concentration at the site of action is required. Since the introduction of the term intracrinology as the local formation of active steroid hormones from inactive precursors of the adrenal gland, mainly dehydroepiandrosterone (DHEA) and DHEA-S, it is evident that blood circulating levels of sex steroid hormones need not reflect their actual concentrations in the tissue.

Endocrine disruptors and gut microbiome interactions.

Anthropogenic environmental pollutants affect many physiological, biochemical, and endocrine actions as reproduction, metabolism, immunity, behavior and as such can interfere with any aspect of hormone action. Microbiota and their genes, microbiome, a large body of microorganisms, first of all bacteria and co-existing in the host´s gut, are now believed to be autonomous endocrine organ, participating at overall endocrine, neuroendocrine and immunoendocrine regulations. While an extensive literature is available on the physiological and pathological aspects of both players, information about their mutual relationships is scarce.

Glucocorticoids affect male testicular steroidogenesis.

Through their receptors at each level of hypothalamo-pituitary-gonadal axis glucocorticoid excess, either endogenous or administered or stress-induced, could affect steroid production in the testis and thus male fertility. The main ways by which glucocorticoids act are as follows: 1) Affecting gonadoliberin and LH synthesis and release through glucocorticoid receptors in hypothalamic neurons and pituitary gonadotropes. 2) By so far not clearly evidenced reduction of the number of LH receptors on the membrane of Leydig cells.

Serum and intratesticular sex steroids in azoospermic men: how do they correlate?

Five intratesticular sex steroids (testosterone, dihydrotestosterone, androstenedione, estradiol and epitestosterone) along with six serum hormones (LH, FSH, prolactin, SHBG, testosterone and estradiol) were determined in 84 non-obstructive azoospermic men, in order to evaluate to what extent serum and testicular tissue as well as individual hormones in the same material mutually correlate. With exception of androstenedione, tight correlations were found among tissue content of sex steroids, while only weak correlation was recorded between serum and testicular concentrations of major sex steroids testosterone and estradiol. It points to importance of measurement of intratesticular steroids in combination with examination of sperm parameters for assessment of testicular function and spermatogenesis.

Phthalate metabolites in maternal and cord plasma and their relations to other selected endocrine disruptors and steroids.

Endocrine disruptors (EDs) are known to have harmful effects on the human endocrine system; special effort is actually given to the exposure during pregnancy. Humans are usually exposed to a mixture of EDs, which may potentiate or antagonize each other, and the combined effect may be difficult to estimate. The main phthalate monoesters monoethyl-, mono-n-butyl-, monoisobutyl-, monobenzyl-, mono-(2-ethylhexyl)-, mono-(2-ethyl-5-hydroxyhexyl)- and mono-(2-ethyl-5-oxohexyl) phthalate were determined in 18 maternal (37th week of pregnancy) and cord plasma samples using liquid chromatography-tandem mass spectrometry.

Impaired vitamin D sensitivity.

Resistance to vitamin D has been known for decades as vitamin D resistant rickets, caused by mutations of the gene encoding for vitamin D receptor (VDR). Findings of extra-skeletal effects of vitamin D and learning of the molecular mechanisms used by its biologically active metabolite calcitriol revealed other ways leading to its impaired sensitivity. Calcitriol takes advantage of both genomic and non-genomic mechanisms through its binding to vitamin D receptor, located not only in the cell nuclei but also in a perinuclear space.

Exposure to bisphenols and parabens during pregnancy and relations to steroid changes.

Background: The harmful effects of endocrine disrupting compounds (EDCs) on human health are generally well-known, and exposure during fetal development may have lasting effects. Fetal exposure to bisphenol A (BPA) has been recently relatively well-studied; however, less is known about alternatives such as bisphenol S (BPS), bisphenol F (BPF) and bisphenol AF (BPAF), which have started to appear in consumer products. Parabens are another widespread group of EDCs, with confirmed transplacental passage.

Occurrence and reproductive roles of hormones in seminal plasma.

Only 2-5% of seminal fluid is composed of spermatozoa, while the rest is seminal plasma. The seminal plasma is a rich cocktail of organic and inorganic compounds including hormones, serving as a source of nutrients for sperm development and maturation, protecting them from infection and enabling them to overcome the immunological and chemical environment of the female reproductive tract. In this review, a survey of the hormones found in human seminal plasma, with particular emphasis on reproductive hormones is provided.

Vitamin D supplementation changed relationships, not levels of metabolic-hormonal parameters in autoimmune thyroiditis.

In women with chronic autoimmune thyroiditis and vitamin D deficiency we have found reference levels of relevant metabolic-hormonal parameters except for parathormone and total calcium. Three months supplementation with vitamin D (4300 IU/day, cholekalciferol) did not lead to significant changes of investigated hormonal parameters, while the levels of parathormone and calcium reached normal levels. However, a correlation analysis revealed marked changes in mutual relations.

Peripheral sensitivity to steroids revisited.

Resistance to steroid hormones presents a serious problem with respect to their mass use in therapy. It may be caused genetically by mutation of genes involved in hormonal signaling, not only steroid receptors, but also other players in the signaling cascade as co-regulators and other nuclear factors, mediating the hormone-born signal. Another possibility is acquired resistance which may develop under long-term steroid treatment, of which a particular case is down regulation of the receptors.

Determination of selected bisphenols, parabens and estrogens in human plasma using LC-MS/MS.

In this study, a novel liquid chromatography - tandem mass spectrometry method for the simultaneous determination of bisphenols (BPA, BPS, BPF, BPAF), parabens (methyl-, ethyl-, propyl-, butyl-, benzyl-paraben) and estrogens (estrone, estradiol, estriol) in human plasma is presented. Since all analytes possess the phenolic group, dansyl chloride derivatization was applied in order to gain high sensitivity. The method was validated according to FDA guidelines, and all validation requirements were satisfactory.

Prevalence of Mycoplasma hominis and Ureaplasma urealyticum in women undergoing an initial infertility evaluation.

Aims: Mycoplasma hominis and Ureaplasma urealyticum are potentially pathogenic bacterial species that are frequently isolated from the urogenital tract of women. These pathogens could be responsible for various genitourinary diseases and have been associated with adverse pregnancy outcomes and female fertility problems. The aim of this study was to analyse the presence of M.

Amino acid metabolism in human embryos.

The aim of this study was to find some relationship between amino acid metabolism and the embryo morphokinetic parameters studied via time-lapse analysis. Study included 48 human embryo samples and their culture media. Two groups of embryos were identified: embryos reached the 8-cell stage on day 3 (n=34) and embryos failed to develop at any point during the incubation (n=14).

Associations of bisphenol A and polychlorinated biphenyls with spermatogenesis and steroidogenesis in two biological fluids from men attending an infertility clinic.

Background: In the testis, steroid hormones play an important role in spermatogenesis, the production of semen, and the maintenance of secondary sex characteristics and libido. They may also play a role as a target for substances called endocrine disruptors (EDs). As yet, however, no complex study has been conducted evaluating the relationships between EDs and the steroid spectrum in the plasma and seminal plasma.

Vitamin D and thyroid diseases.

In this review we summarize recent opinions on the possible role of vitamin D in the risk of thyroid diseases development. It may be concluded from the available data that vitamin D deficiency, particularly levels below 12.5 ng/ml should be considered as an additional, but important risk factor for development of thyroid autoimmunity, both chronic autoimmune thyroiditis and Graves' disease.

Differences in bisphenol A and estrogen levels in the plasma and seminal plasma of men with different degrees of infertility.

The general population is potentially exposed to many chemicals that can affect the endocrine system. These substances are called endocrine disruptors (EDs), and among them bisphenol A (BPA) is one of the most widely used and well studied. Nonetheless, there are still no data on simultaneous measurements of various EDs along with steroids directly in the seminal fluid, where deleterious effects of EDs on spermatogenesis and steroidogenesis are assumed.

The impact of selected cytokines in the follow-up of normal pressure hydrocephalus.

Cytokines are widely known mediators of inflammation accompanying many neurodegenerative disorders including normal pressure hydrocephalus (NPH). NPH is caused by impaired cerebrospinal fluid (CSF) reabsorption and treated by surgical shunt insertion. The diagnostics is still complicated and the shunt effect is not durable; after several years, dementia may develop.

How hormones influence composition and physiological function of the brain-blood barrier.

Hormones exert many actions in the brain. Their access and effects in the brain are regulated by the blood-brain barrier (BBB). Hormones as other substances may enter the brain and vice versa either by paracellular way requiring breaching tight junctions stitching the endothelial cells composing the BBB, or by passage through the cells (transcellular way).

DHEA, DHEAS and prolactin correlate with glucose control parameters in women of fertile age with type-1 diabetes mellitus.

The aim of our work was to provide data from women of fertile age with type 1 diabetes mellitus about the endogenous androgens and on their relations to the parameters of diabetes control. Forty-two women were examined, they did not use contraceptives for at least three months prior to the examination. A multivariate regression analysis showed that the daily insulin dose, the fasting glycemia and the HbA1c values and patient's age correlated negatively with dehydroepiandrosterone sulfate, dehydroepiandrosterone and prolactin levels.

Steroid hormones and homocysteine in the outcome of patients with normal pressure hydrocephalus.

Normal pressure hydrocephalus (NPH) is one of a few treatable conditions of cognitive decline affecting predominately elderly people. Treatment, commonly based on the ventriculoperitoneal shunt insertion, leads to a partial or complete correction of patient's state, although its effect does not unfortunately always last. The aim of our study was to observe the changes of homocysteine and selected steroids and neurosteroids and follow-up the patients with respect to the duration of the NPH-related dementia improvement.

Development and validation of LC-MS/MS method for quantification of bisphenol A and estrogens in human plasma and seminal fluid.

Bisphenol A (BPA) is a widely known endocrine disruptor with estrogenic, antiestrogenic or antiandrogenic properties. BPA could interfere with estrogen metabolism as well with receptor-mediated estrogen actions. Both environmental BPA and estrogens may be traced in body fluids, of which, besides the blood plasma, the seminal fluid is of particular interest regarding their possible interactions in the testis.