Zygmunt Zdrojewicz

Medical applications of nanotechnology.

Nanotechnologies are new areas of research focusing on affecting matter at the atomic and molecular levels. It is beyond doubt that modern medicine can benefit greatly from it; thus nanomedicine has become one of the main branches of nanotechnological research. Currently it focuses on developing new methods of preventing, diagnosing and treating various diseases. Nanomaterials show very high efficiency in destroying cancer cells and are already undergoing clinical trials. The results are so promising that nanomaterials might become an alternative to traditional cancer therapy, mostly due to the fact that they allow cancer cells to be targeted specifically and enable detailed imaging of tissues, making planning further therapy much easier. Nanoscience might also be a source of the needed breakthrough in the fight against atherosclerosis, since nanostructures may be used in both preventing and increasing the stability of atherosclerotic lesions. One area of interest is creating nanomaterials that are not only efficient, but also well tolerated by the human body. Other potential applications of nanotechnology in medicine include: nanoadjuvants with immunomodulatory properties used to deliver vaccine antigens; the nano-knife, an almost non-invasive method of destroying cancer cells with high voltage electricity; and carbon nanotubes, which are already a popular way of repairing damaged tissues and might be used to regenerate nerves in the future. The aim of this article is to outline the potential uses of nanotechnology in medicine. Original articles and reviews have been used to present the new developments and directions of studies.

The Thymus: A Forgotten, But Very Important Organ

Medical science seems to be on the threshold of a revolution: It seems possible that in twenty years, doctors will be able to replace organs in the human body like parts in a car. This is thanks to the recent achievement of a team from the Medical Research Council Center for Regenerative Medicine in Edinburgh, Scotland - the group of researchers tried to regenerate the thymus gland in mice. The thymus gland is an essential organ for the development of the immune system, but very few people have any idea that it exists. In the literature and also in peoples awareness, the fact is often that the thymus controls and harmonizes the entire immune system and the immune functioning of the organism. It is the primary donor of cells for the lymphatic system, much as bone marrow is the cell donor for the cardiovascular system. It is within the thymus that progenitor cells are created and then undergo maturation and differentiation into mature T cells. The thymus gland is located in the mediastinum, behind the sternum. It is composed of two identical lobes. Each lobe is divided into a central medulla and a peripheral cortex. The thymus is at its largest and most active during the neonatal and pre-adolescent periods. After this period the organ gradually disappears and is replaced by fat. In elderly individuals the thymus weighs 5 g. The aim of this work is to shed new light on this important immune defense organ, whose function is not confined to the destruction of nonfunctional T cells.

Brdt Bromodomains Inhibitors and Other Modern Means of Male Contraception

Compared to efficient and secure female contraception, a vasectomy and condoms are the only options for men. The choice of male contraceptive methods is limited, so contraception mainly rests on the shoulders of women. Several concepts are considered: testosterone administration--inhibiting pituitary secretion of lutropin (LH) and follicle stimulating hormone (FSH), progestogen--affecting the secretion of gonadotropin and gonadoliberin (GnRH) antagonists. New potential targets for non-hormonal male contraception were discovered: glyceraldehyde-3-phosphate-dehydrogenase (GAPDHS)--specific to male germ cells and voltage-gated cation channel (CatSper). Both are responsible for sperm motility. Drugs such as thioridazine used in schizophrenia treatment and phenoxybenzamine (antihypertensive activity) exhibit a contraceptive effect. Similar action exhibits an analogue of lonidamine--adjudin and an antagonist of retinoic acid receptors (BMS-189453). Researchers are working on a contraceptive vaccine, whose active ingredient is epididymal protease inhibitor (Eppin). Another promising method acts by blocking Bromodomain testis-specific proteins (Brdt) involved in the process of spermatogenesis. JQ1-the Brdt inhibitor causes reversible infertility without affecting the endocrine signaling pathways. A recent discovery of Juno as the binding partner for Izumo1 identifies these proteins as the cell-surface receptor pair, essential for gamete recognition and this interaction can be inhibited by an anti-Juno monoclonal antibody. Our review shows that the situation of men can change and investigators are close to the optimal solution. In the near future men will be able to choose the best contraceptive suited to their needs.

Hen's egg as a source of valuable biologically active substances.

The aim of this article is to show current knowledge concerning valuable substances biologically active present in hen eggs and underline important nutritive role of hen eggs. Hen egg is a good source of nutrients such as proteins, vitamins (A, B2, B6, B12, D, E, K), minerals and lipids. The significant part of lipids is a group of unsaturated phospholipids, which are components of cell membranes, act protectively on the cardiovascular system and contribute to a decrease of cholesterol level and blood pressure. Therefore, the consumption of unsaturated phospholipids is recommended especially in patients suffering from diseases of the cardiovascular system. Another important substance is egg cystatin, which has a wide spectrum of biological functions, for example the ability to stimulate cell growth, inhibit inflammatory processes and has antibacterial and antiviral properties. Other substance presented in the egg white which helps fight bacteria is lysozyme. It is used in medicine as an aid in antibiotic therapy and analgesic in the course of infection, as well as in tumor malignancies. Among the components contained in the egg yolk there is also immunoglobulin Y which due to its therapeutic importance deserves special attention. Its use offers the possibility of replacing chemotherapeutic agents in the treatment of bacterial infections of digestive system, as well as an opportunity for the development of medicine associated with passive immunization of patients. The egg is a rich source of retinol which gradual depletion in the organism causes many eye pathologies. A very important and useful part of the egg, used in medicine is a shell and its membranes, due to the high collagen content relevant in the treatment of connective tissue diseases.

Influence of ionizing radiation on human body

W niniejszej pracy przedstawiono zagadnienia dotyczące negatywnego i pozytywnego wpływu promieniowania jonizującego na organizm człowieka. Promieniowanie jonizujące we współczesnej medycynie wykorzystywane jest w leczeniu, diagnostyce i radiologii zabiegowej i z tego powodu stanowi ważny aspekt w praktyce klinicznej zarówno dla lekarza, jak i pacjenta. W związku z interdyscyplinarną i powszechną naturą zjawiska ważne wydaje się poznanie skutków promieniowania jonizującego. obowiązujące zasady i ograniczenia dotyczące stosowania promieniowania jonizującego w medycynie umożliwiają zoptymalizowanie dawki pochłanianej przez organizm i tym samym ograniczają nadmierną ekspozycję na promieniowanie, z jednoczesnym ograniczeniem negatywnych skutków. Wśród koncepcji dotyczących wpływu promieniowania jonizującego na organizm ludzki wyróżnia się powszechnie akceptowaną teorię liniową: progową i bezprogową, a także zupełnie jej przeciwstawną hormezę radiacyjną. Pomimo faktu, iż obowiązujące standardy ochrony radiologicznej oparte są na teorii liniowej, to hormeza radiacyjna wzbudza coraz większe zainteresowanie i podejmowane są liczne próby dowiedzenia jej prawdziwości. kolejne badania naukowe poszerzające wiedzę na temat hormezy radiacyjnej mogą zmienić oblicze przyszłości. Być może badania te otworzą nowe możliwości zastosowania promieniowania jonizującego, jak i umożliwią obliczenie optymalnej i spersonalizowanej dawki dla pacjenta, pozwalając nam na wyznaczenie nowego „złotego środka” dla promieniowania jonizującego. W związku z tym uważamy, że przed zastosowaniem tych metod jest duża przyszłość, niemniej powinno się mieć na uwadze głównie dobro pacjenta. Słowa kluczowe: promieniowanie jonizujące, radiologia zabiegowa, hormeza radiacyjna.