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  • Author: Maurycy Jankowski x
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Factors involved in the development of pituitary and hypothalamus: a short review

Abstract

A large amount of complex hormone associated processes occurring continuously in the human organism is necessary to maintain homeostasis in response to various internal and external conditions. In the same time, as the hormones use the bloodstream as their transmission medium, it is essential that their expression is strictly controlled to maintain their activity only when it is required. Because of that, the endocrine system evolved complex, self-regulating machinery that allows for precise signalling to the glands to initiate hormone expression, as well as equally quick negative feedback in the moment of reaching the optimal blood hormone concentration. The pituitary gland serves as the true endocrine part of that system, expressing a range of hormones that mostly serve as regulators of sub-systems serving different functions, scattered around organisms. The hypothalamus is the neuroendocrine part of the hypothalamic-pituitary axis, meaning it integrates the neuronal and hormonal signals, effectively linking the nervous and endocrine systems. The processes of hypothalamus and pituitary development share some significant similarities, which is unsurprising considering their close association and anatomical proximity at the base of the brain. Arising in highly overlapping developmental timeframes, they are both initially patterned by the gradients of extrinsic signalling molecules. After the initial lineage commitment, in both of those structures, intrinsic factors expressed by the distinct cell populations sustain the morphogenesis to result in a final complexly patterned structure. In this short review, the processes of the pituitary and hypothalamus development are described, with the most important factors driving them discussed.

Open access
Drosophila melanogaster research: history, breakthrough and perspectives

Abstract

The common fruit fly, or Drosophila Melanogaster, has been used as an object of biomedicals studies for over a century. It has been mostly employed in genetic research, as it exhibits several advantages which make its use relatively easy and cheap, with the results widely translatable into further vertebrate studies. This model been the basis of the work of Christiane Nusslein-Volhard, who together with Eric Wieschaus unravelled much of the mystery surrounding early drosophila development in the 1970s-1980s, laying foundations for broader understanding of multicellular organism embryogenesis, which brought them a Nobel prize in Physiology and Medicine in 1995. The knowledge gained from drosophila studies improves the basic understanding of developmental processes, while the model itself is relatively easy to maintain, analyse and translate the results onto other species. While models such as Zebrafish present better with other vertebrates, drosophila remains a very important element of genetic research, finding even more applications with the development of current science and medicine. Hence, in this short review, the outline of the history, breakthroughs and perspectives of the drosophila research has been presented.

Open access
Splenic Leiomyoma in Dog

Abstract

Leiomyoma is a benign tumour, originating from smooth muscles cells. This tumor commonly involves the uterus, vagina, stomach, intestine, urinary bladder and other organs. Only a few cases of splenic leiomyoma in dogs have been reported in the available literature. Much more frequently malignant leiomyosarcoma was found. The aim of this study was to compile rare clinical case of splenic leiomyoma in dog, which developed with no clinical signs and no abnormalities in blood findings. A 14-year-old, spayed bitch was examined with ultrasonography, where lesions on the spleen were identified. Based on the clinical findings (blood test in norm, no metastases in X-ray examination) surgical removal of spleen was recommended. Two fragments of tumors were prepare for histopathological examination. The lesion was described as smooth muscle benign tumor, therefore a diagnosis of leiomyoma was made. About a year after splenectomy no signs of metastases were present in a ultrasound and X-ray examinations. This report indicates the necessity of taking the occurrence of benign lesions in the spleen into account. Splenectomy based on the presence of tumor lesion should be associated with histopathological examination to identify the nature of change. This clinical case, despite a marked morphological lesion shown during intraoperative examination, was benign with successful prognosis.

Open access
Stemness specificity of epithelial cells – application of cell and tissue technology in regenerative medicine

Abstract

Stem cells are cells that have the potential to replicate and/or differentiate, becoming any tissue. This process could be theoretically repeated indefinitely and can be used to create or fix damaged parts any organ. There are many in vivo factors that cause stem cells to replicate and differentiate. Many of these interactions and mechanisms are still unknown. In vitro models have been successful in inducing stem cells to differentiate into the desired lineage using controlled methods. Recently, epithelial tissue has been successfully created using scaffolds on which stem cells are grown in vitro and then transplanted into the host. This transition creates significant problems. This is because in vitro -grown stem cells or stem cell-derived tissues are created in an isolated environment where virtually every aspect can be monitored and controlled. In vivo monitoring and controlling is significantly more difficult for a plethora of reasons. Cells in the body are constantly exposed to many signals and molecules which affect them. Many of the mechanisms behind these interactions and reactions are known but many others are not. As the corpus of knowledge grows, stem cells become closer to being applied in a clinical setting. In this paper, we review the current evidence on stem cell therapy in regenerative medicine and some of the challenges this field faces.

Open access
Characteristic of factors influencing the proper course of folliculogenesis in mammals

Abstract

Folliculogenesis is the process of ovarian follicle formation,, taking presence during foetal period. During the follicular development, oogoniums undergo meiosis and oocytes are formed. In the ovaries of new born sows, primary and secondary follicles are present and, 90 days after birth, tertiary follicles appear. During development in the ovarian follicles growth of granulosa cells and differentiation of the thecal cells can be observed. A cavity filled with follicular fluid appears. Granulosa cells are divided into: mural cells and corona radiata, which together with the oocyte form the cumulus oophorus. Corona radiata cells, mural layers and oolemma contact each other by a network of gap junctions. Secreted from the pituitary gland, FSH and LH gonadotropin hormones act on receptors located in granular and follicular cells. In the postnatal life tertiary follicles and Graafian follicles are formed. When the follicle reaches a diameter of 1 mm, further growth depends on the secretion of gonadotropins. Mature ovarian follicles produce: progestins, androgens and oestrogens. The growth, differentiation and steroidogenic activity of ovarian follicles, in addition to FSH and LH, is also affected by prolactin, oxytocin, steroid and protein hormones, numerous proteins from the cytokine and interleukin family, metabolic hormones like insulin, glucocorticoids, leptin, thyroid hormones and growth hormones. Despite numerous studies, many processes related to folliculogenesis have not been discovered Learning the mechanisms regulating reproductive processes would allow to easily distinguish pathological processes and discover more and more genes and mechanisms of their expression in cells that build ovarian follicles.

Open access
Pathogenesis and pathophysiology of ovarian follicular cysts in mammals

Abstract

Ovarian cysts remain to be one of the most common and serious problems in reproduction of farm animals, as well as humans. Apart from causing the fall in reproductive potential of the ovaries, occupying the place in which folliculogenesis and oogenesis occur, they also cause hormone imbalances, by preventing corpus luteum formation, hence lowering the amount of steroid hormone production. While singular cysts rarely affect fertility, hormone fluctuations that are associated with their presence promotes their multiplication, which usually has more adverse effects. While the cysts are easily detectable in humans, possessing distinct echography while examined by ultrasound, multiple factors prevent widespread use of effective detection methods among large herds of farm animals. Because of lack of noticeable symptoms of early stages of such malignancies, they rarely get detected before the animal stops to exhibit symptoms of heat. That causes scientific research to be focused on not only methods of detection, but also the ways to negate the effects of ovarian cysts and bring the affected specimen back to reproductive potential. Despite that, high costs of diagnosis and treatment, cause them to be uncommon on commercial farms. As lack of fertility eliminates animals from breeding purposed herds, ovarian cysts persist as a cause of large losses of the animal husbandry business. Continuous research, focused on natural examples of ovarian cysts should be conducted, in order to improve methods of detection, prevention, treatment and recovery from the effects of ovarian cysts.

Open access
Transforming growth factor (TGF) – is it a key protein in mammalian reproductive biology?

Abstract

The superfamily of transforming growth factors β (TGF-β) consists of cytokines that are crucial in regulating the organism’s biological functions and includes three isoforms of TGF-β protein, Anti-Müllerian Hormone (AMH), inhibin A and B, activins, 20 bone morphogenetic proteins (BMP1-20) and 9 growth factors (GDF1-9). Their signal transduction pathway involves three types of membrane receptors that exhibit a serine/threonine kinase activity, as well as the Smad proteins. After ligand binding, the Smad proteins are phosphorylated and translocated to the nucleus, where they interact with transcription factors and affect gene expression. TGF-β family members are involved in cell growth and differentiation, as well as chemo-taxis and apoptosis, and play an important role during an inflammation. Defects in TGF-β proteins or in their signalling pathway underlie many severe diseases, such as systemic lupus, systemic scleroderma, bronchial asthma, atherosclerosis, hyperthyroidism or cancer. These factors are also crucial in mammal reproductive functions, as they are involved in folliculogenesis, steroidogenesis, ovulation, maternal-embryo interaction, embryo development and uterine decidualization. Their defects result in issues with fertility. This review focuses on the relevance of TGF-β family members in a mammal reproduction with an emphasis on three TGF-β isoforms, inhibins A and B, GDF-9 and their signal transduction pathway.

Open access
The use of mesenchymal stem cells in veterinary medicine

Abstract

Constant advances in medicine, both human and veterinary, lead to continuous discovery of new drugs and treatments. Recently, the aspect of stem cell use in regenerative medicine has been very popular. There are still too few clinical trials on animals that could precisely estimate the therapeutic efficacy of cell therapy. However, stem cells are a source of extraordinary potential for multiplication and differentiation which, if used properly, can prove to be an effective mean of treatment of numerous diseases that are currently considered untreatable. The purpose of review is the characterization and clinical use of stem cells in mostly occurring diseases. Particular attention has been given to the issue of mesenchymal stromal cells, which so far have been most widely used in clinical practice. Current research into stem cells has allowed scientists to discover many different types of these cells, describe their characteristics and divide them into groups, with the most important being embryonic stem cells and somatic (adult) stem cells. Adult stem cells, due to their availability and lack of ethical problems, are used in veterinary practice. Different types of mesenchymal stem cells are distinguished, based on their origin. Adipose tissue derived stem cells and stromal vascular fraction find the widest clinical application. In veterinary medicine, stem cells therapies are most commonly used in the case of horse orthopedic injuries and in diseases of various origin in dogs and cats. While further research is needed to confirm the effectiveness of cell therapies, they have much potential to find plenty of potential applications in future medicine.

Open access
Cytoplasmic and nuclear maturation of oocytes in mammals – living in the shadow of cells developmental capability

Abstract

The pig is a polyestrous animal in which the ovarian cycle lasts about 21 days and results in ovulation of 10-25 oocytes. Ovum reaches 120-150 μm in diameter, with the surrounding corona radiata providing communication with the environment. The zona pellucida is composed of glycoproteins: ZP1, ZP2, ZP3. In the course of oogenesis, RNA and protein accumulation for embryonic development occurs. Maternal mRNA is the template for protein production. Nuclear, cytoplasmic and genomic maturity condition the ability of the ovum to undergo fertilization. There are several differences in protein expression profiles observed between in vitro and in vivo conditions. Oogenesis is the process of differentiating female primary sex cells into gametes. During development gonocytes migrate from the yolk sac into the primary gonads with TGF-1, fibronectin, and laminin regulating this process. Cell cycle is blocked in dictyotene. Primary oocyte maturation is resumed before each ovulation and lasts until the next block in metaphase II. At the moment of penetration of the sperm into the ovum, the metaphase block is broken. The oocytes, surrounded by a single layer of granular cells, form the ovarian follicle. The exchange of signals between the oocyte and the cumulus cells done by gap-junctions, as well as various endo and paracrine signals. The contact between the corona radiata cells provides substances necessary for growth, through the same gap junctions. Studies on follicular cells can be used to amplify the knowledge of gene expression in these cells, in order to open way for potential clinical applications.

Open access
Ontology groups representing angiogenesis and blood vessels development are highly up-regulated during porcine oviductal epithelial cells long-term real-time proliferation – a primary cell culture approach

Abstract

The morphological and biochemical modification of oviductal epithelial cells (OECs) belongs to the group of compound processes responsible for proper oocyte transport and successful fertilization. The cellular interactions between cumulus-oocyte complexes (COCs) and oviductal epithelial cells (OECs) are crucial for this unique mechanism. In the present study we have analyzed angiogenesis and blood vessel development processes at transcript levels. By employing microarrays, four ontological groups associated with these mechanisms have been described. Differentially expressed genes belonging to the “angiogenesis”, “blood circulation”, “blood vessel development” and “blood vessel morphogenesis” GO BP terms were investigated as a potential markers for the creation of new blood vessels in cells under in vitro primary culture conditions.

Open access