Time filter

Source Type

Wojcik S.,Medical University of Gdansk
Folia Histochemica et Cytobiologica | Year: 2013

The Ubiquitin-Proteasomes System (UPS) and autophagy, two main intracellular protein degradation pathways within the eukaryotic cells which were originally regarded as rather independent, seem to be very closely related. Proteasome inhibitors, including the multipathway inhibitor bortezomib, are drawing increased attention for their therapeutic potential in the treatment of chronic inflammation and cancer, especially tumours with a high degree of malignancy. The over-activation of autophagy induces cell death and may act as a powerful tumour-suppressing mechanism. However, autophagy, serving as an important mechanism to generate nutrients in time of cellular stresses, may directly contribute to the survival of cells treated with proteasome inhibitors, and in consequence, may decrease the effectiveness of therapy. Results of studies performed on several cancer cell lines demonstrated synergy between proteasome inhibitors and autophagy inhibitors. Those results became the base for ongoing clinical trials investigating autophagy inhibition in combination with anti-cancer therapies, including bortezomib. This review provides summary of the latest data on the functioning of the UPS and the mechanisms of autophagy. The new insights describing the main pathways of autophagy activation in response to UPS inhibition related to: (i) Unfolded Protein Response, (ii) PI3K/Akt/mTOR pathway, and (iii) formation of aggresomes, are discussed. It is concluded that concomitant inhibition of the two main cellular protein degradation systems may provide new therapeutic modalities for cancer treatment. © Polish Society for Histochemistry and Cytochemistry. Source

Dopamine is an inhibitory neurotransmitter involved in the pathology of schizophrenia. The revised dopamine hypothesis states that dopamine abnormalities in the mesolimbic and prefrontal brain regions exist in schizophrenia. However, recent research has indicated that glutamate, GABA, acetylcholine, and serotonin alterations are also involved in the pathology of schizophrenia. This review provides an in-depth analysis of dopamine in animal models of schizophrenia and also focuses on dopamine and cognition. Furthermore, this review provides not only an overview of dopamine receptors and the antipsychotic effects of treatments targeting them, but also an outline of dopamine and it's interaction with other neurochemical models of schizophrenia. The roles of dopamine in the evolution of the human brain and human mental abilities, which are affected in schizophrenia patients, are also discussed. © 2014 Brisch. Source

Jamrogiewicz M.,Medical University of Gdansk
Journal of Pharmaceutical and Biomedical Analysis | Year: 2012

Near-infrared (NIR) spectroscopy is currently the fastest-growing and the most versatile analytical method not only in the pharmaceutical sciences but also in the industry. This review focuses on recent NIR applications in the pharmaceutical technology. This article covers monitoring, by NIR, of many manufacturing processes, such as granulation, mixing or drying, in order to determine the end-point of these processes. In this paper, apart from basic theoretical information concerning the NIR spectra, there are included determinations of the quality and quantity of pharmaceutical compounds. Some examples of measurements and control of physicochemical parameters of the final medicinal products, such as hardness, porosity, thickness size, compression strength, disintegration time and potential counterfeit are included. Biotechnology and plant drug analysis using NIR is also described. Moreover, some disadvantages of this method are stressed and future perspectives are anticipated. © 2012 Elsevier B.V. Source

Dubaniewicz A.,Medical University of Gdansk
Autoimmunity Reviews | Year: 2010

Sarcoidosis (SA) is a granulomatous disorder of an unknown etiology. Infectious, genetic factors and autoimmunity have been explored as potential causes of SA. Pathologic similarities between SA and tuberculosis (TB) suggest Mycobacterium tuberculosis, especially mycobacterial antigen(s) e.g. heat shock proteins (Mtb-hsp) as causative factors. Mtb-hsp, especially Mtb-hsp65, may provide a link between infection and autoimmunity by cross-reactivity between the mycobacterial and human hsp. There is 100% homology between M. tuberculosis and Mycobacterium bovis BCG hsp. In light of evidences necessary to establish SA which is autoimmune in origin, my recently published findings prompted me to raise the hypothesis that, in genetically different individuals, the same antigens (Mtb-hsp) may induce different immune responses, leading to the development of SA or TB. The hypothesis seems to have been supported by an epidemiological analysis of the worldwide SA and TB prevalences that reveal that the TB distribution is approximately opposite to that of SA. Because one third of the Earth's population has been infected with M. tuberculosis, it is possible that the presence of mycobacterial infection or BCG vaccination (e.g., Mtb-hsp65) in genetically predisposed host may be involved in the development of autoimmunity. © 2009 Elsevier B.V. All rights reserved. Source

Staphylococcus aureus, a major human pathogen causes a wide range of disease syndromes. The most dangerous are methicillin-resistant S. aureus (MRSA) strains, resistant not only to all β-lactam antibiotics but also to other antimicrobials. An alarming increase in antibiotic resistance spreading among pathogenic bacteria inclines to search for alternative therapeutic options, for which resistance can not be developed easily. Among others, photodynamic inactivation (PDI) of S. aureus is a promising option. Photodynamic inactivation is based on a concept that a non toxic chemical, called a photosensitizer upon excitation with light of an appropriate wavelength is activated. As a consequence singlet oxygen and other reactive oxygen species (e.g. superoxide anion) are produced, which are responsible for the cytotoxic effect towards bacterial cells. As strain-dependence in photodynamic inactivation of S. aureus was observed, determination of the molecular marker(s) underlying the mechanism of the bacterial response to PDI treatment would be of great clinical importance. We examined the role of superoxide dismutases (Sod) in photodynamic inactivation of S. aureus as enzymes responsible for oxidative stress resistance. The effectiveness of photodynamic inactivation towards S. aureus and its Sod isogenic mutants deprived of either of the two superoxide dismutase activities, namely SodA or SodM or both of them showed similar results, regardless of the Sod status in TSB medium. On the contrary, in the CL medium (without Mn++ ions) the double SodAM mutant was highly susceptible to photodynamic inactivation. Among 8 clinical isolates of S. aureus analyzed (4 MRSA and 4 MSSA), strains highly resistant and strains highly vulnerable to photodynamic inactivation were noticed. We observed that Sod activity as well as sodA and sodM transcript level increases after protoporphyrin IX-based photodynamic treatment but only in PDI-sensitive strains. We confirmed that porphyrin-based photokilling efficacy is a strain-dependent phenomenon. We showed that oxidative stress sensitivity caused by the lack of both Sod enzymes can be relieved in the presence of Mn ions and partially in the presence of Fe ions. The fact that Sod activity increase is observed only in PDI-susceptible cells emphasizes that this is probably not a direct factor affecting S. aureus vulnerability to porphyrin-based PDI. Source

Discover hidden collaborations