Rationale and study design of a trial to assess rTMS add-on value for the amelioration of negative symptoms of schizophrenia (RADOVAN)

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Pseudo-aneurysms after iatrogenic affection of artery--experiences and recommendations for procedures to prevent their incidence and potential treatment

In the present modern times we see that the population is gradually ageing and along with it also the incidence of civilisation diseases, including those of the cardiovascular system, is increasing. As the care of these patients develops, so does the number of surgeries of invasive cardiology. Even though the development in this area is still dynamic, the techniques are improving and new technologies are appearing. However, these invasive methods are still associated with certain risks for the patient. In terms of vascular surgery, the most frequent complications are iatrogenic pseudo-aneurysms and large haematomas. The objective of the present study was to evaluate the development in the incidence of pseudo-aneurysms (PSA) appearing after punctures of femoral artery due to coronarography or PTCA, to verify the hypothesis that the ratio of the number of PSA to the total number of invasive-cardiologic diagnostic and therapeutic surgeries is decreasing and to indicate possible solutions of complications associated with catheterisation. The study presents a retrospective account of the number of invasive surgeries conducted at the 1st Department of Medicin - Cardioangiology of the St. Anne's University Hospital Brno (UH) from 1996 to 2004. Summarised are numbers of PSA's conducted in this period by surgeons of the 2nd Department of Surgery of the St. Anne's University Hospital Brno (Tab. 1, Fig. 5, Ref. 17).

Cell cycle arrest induced in human breast cancer cells by cyclin-dependent kinase inhibitors: a comparison of the effects exerted by roscovitine and olomoucine

Cyclin-dependent kinases (CDKs) are serine/threonine kinases that play a key role in the regulation of the cell cycle progression. In proliferating cells, distinct CDKs activated upon complexing with specific cyclins and upon site-specific phosphorylation coordinate in an orchestrated way the appropriate transition between consecutive phases of the cell cycle. Aberrant expression or altered activity of distinct CDK complexes results in escape of cells from the cell cycle control and leads to malignant transformation. Therefore, the inhibition of CDKs in malignant cells provides a new strategy in the fight against cancer. Recently, selective CDK inhibitors targeting distinct CDKs were developed. They represent promising anti-cancer drugs due to their strong anti-proliferative efficacy combined with a relative low direct cytotoxicity. The aim of this study was to compare the effect of two related CDK inhibitors: roscovitine (ROSC) and olomoucine (OLO) on the cell cycle progression in human breast cancer MCF-7 cells. Both examined CDK inhibitors differentially affected the cell cycle progression in MCF-7 cels. Whereas ROSC arrested cells in G(2)/M, OLO inhibited cells at S to G(2) transition and increased the number of cells residing in the S-phase. Moreover, both CDK inhibitors modulated the cell cycle progression with distinct kinetics. Accumulation of G(2)/M-arrested cells beginning 6 h after exposure of cells to ROSC coincided with a strong up-regulation of the p53. Interestingly, ROSC triggered apoptosis in MCF-7 cells by activation of mitochondrial pathway. Loss of the integrity of mitochondrial membrane observed after exposure of cells to ROSC for 6 h led to release of distinct mitochondrial proteins, e.g. apoptosis inducing factor (AIF). In contrast to ROSC, OLO-induced cell cycle changes could be detected after 12 h of the treatment. OLO did not up-regulate p53 protein. It indicates that both examined CDK inhibitors are selective and block the cell cycle progression of human breast carcinoma cells at different phases.

Melatonin protects against ischemia-reperfusion injury and inhibits apoptosis in isolated working rat heart

INTRODUCTION: Melatonin (MEL), a pineal hormone, is well known as a potent antioxidant in a variety of ischemia-reperfusion models. Recent studies have assumed a pivotal role of reactive oxygen species (ROS) in the development of apoptosis. There are few pieces of information concerning a possible protective role of MEL against apoptosis in ischemia-reperfusion injury of myocardium. METHODS: We conducted an in vitro experiment: (1) to study the effect of MEL in the model of isolated and perfused working rat heart; (2) to evaluate the antioxidant capacity of MEL by a simple fluorescence test; and (3) to analyze the extent of apoptosis inhibition by MEL. Four groups of male Wistar rat were used: (a) group 'MEL 50 muM' (n=8); (b) group 'ischemia 30 min' (n=8); (c) group 'controls' (n=8); and (d) group 'controls+MEL 50 muM' (n=8). The perfusion medium was an oxygenated Krebs-Henseleit buffer (KHB). Hearts in groups (a) and (b) underwent 30 min of global normothermic ischemia and 45 min of reperfusion; 3 min before ischemia the hearts of group (a) received KHB with MEL 50 muM (and MEL 50 muM was also present in KHB solution during reperfusion). Hearts of group (c) were only perfused by KHB, and hearts of group (d) perfused by KHB+MEL 50 muM throughout the experiment. Registered were basic hemodynamic parameters: coronary, aortic, cardiac output and heart rate. At the end of each experiment, a left ventricle samples were taken for in situ detection of apoptosis using a TUNEL in-situ detection kit (POD) and quantitative analysis was performed. Malonedialdehyde concentrations were evaluated from heart homogenate to determine the severity of oxidative damage. To study the antioxidant capacity of MEL, a fluorescence test with allophycocyanin as an indicator was performed. A peroxyl radical generator, 2,2'-azobis(2-amidinopropan)-4-hydrochloride (AAPH) was used, and the antioxidant effect of MEL was expressed in oxygen-radical absorbing capacity (ORAC) units. RESULTS: Treatment by MEL resulted in a significant improvement of hemodynamic parameters and reduction of postischemic arrhythmias during reperfusion. All hearts in group 'ischemia 30 min' developed fatal ventricular fibrillations. MEL significantly reduced the incidence of apoptotic cells (14+/-4.3%; **P<0.01) vs. group 'ischemia 30 min' (58+/-2.1%). No apoptotic cells were detected in both control groups (c) and (d). In the fluorescence test, MEL exhibited a significant dose-dependent protective effect against peroxyl radical; MEL also reduced significantly the level of lipoperoxidation (MDA; *P<0.05). Analysis of hemodynamic parameters in both control groups (c) and (d) did not show any significant differences; the presence of MEL 50 muM in KHB solution did not have any important influence on cardiac performance in this type of experiment. CONCLUSION: We confirmed the previously reported beneficial effects of MEL against ischemia-reperfusion injury, presumably via its antioxidant properties. A significant suppression of apoptosis and the peroxyl radical scavenging properties of MEL in our study could contribute to the hypothesis of a close link between oxidative stress and apoptosis promotion.

Prevention of apoptosis by deferoxamine during 4 hours of cold cardioplegia and reperfusion: in vitro study of isolated working rat heart model

INTRODUCTION: Heart transplantation is often accompanied by multiple functional alterations, especially in reperfusion period. These are probably related to the reactive oxygen species (ROS) formation catalyzed by transition metals such as iron and copper, and thus the preservation time of the donor hearts is limited. Metabolic protection of the heart grafts is a permanent objective of numerous experiments. Recently, an iron chelator deferoxamine (DFX) was proposed as antioxidant agent for storage solutions in heart grafts. Oxidative stress is also known to mediate the apoptotic cell death in different tissues during ischemia-reperfusion. METHODS: The aim of this study was to evaluate a possible role of DFX in prevention of apoptosis using in vitro model of isolated working rat heart and cold cardioplegia. Two groups of rats were evaluated: (a) group 'DFX 50 &mgr;M' (n=8) and (b) group 'controls' (n=8). Isolated rat hearts were perfused by Krebs-Henseleit buffer (KHB) for 30 min, arrested by cardioplegic solution and stored for 4 h in B21 solution at 4 degrees C. Then, the hearts were reperfused by KHB for 45 min. DFX was added to the cardioplegic and storage solutions and in KHB in reperfusion. Basic functional parameters were evaluated: coronary, aortic, cardiac outputs and heart rate. At the end of reperfusion period a tissue samples were taken from left ventricle and in situ detection of apoptotic cells was performed using an ApopTag kit. RESULTS: DFX significantly reduced the occurrence of apoptotic cells in myocardium (*P<0.05). Hearts treated by 50 &mgr;M of DFX showed also a better recovery of the cardiac output (***P<0.001). The presence of DFX in KHB, cardioplegic and storage solution reduced also the incidence of postischemic arrhythmias and fibrillation's but without statistical significance. CONCLUSIONS: Our results give evidence of the protective potential of DFX during cold ischemia and reperfusion, presumably due to its antioxidant properties. The significant decrease of apoptosis in hearts treated by DFX could be considered as an existence of close link between oxidative stress and apoptotic death promotion in ischemia-reperfusion injury.

Potent induction of wild-type p53-dependent transcription in tumour cells by a synthetic inhibitor of cyclin-dependent kinases

Activation of the p53 tumour suppressor protein by distinct forms of stress leads to inhibition of cellular proliferation by inducing cell cycle arrest or apoptosis. The cyclin-dependent kinase inhibitor roscovitine has been shown to induce nuclear accumulation of wild-type p53 in human untransformed and tumour-derived cells. We analyzed the response of different human tumour cell lines to roscovitine treatment with respect to their p53 status. Striking induction of wild-type p53 protein and dramatic enhancement of p53-dependent transcription, coinciding with p21WAF1 induction, was observed in wildtype, but not mutant, p53-bearing tumour cells after treatment with roscovitine. The transcriptional activity of p53 was substantially higher in roscovitine-treated cells than in cells irradiated with ultraviolet C or ionizing radiation, even though all these agents induced a similar amount of p53 accumulation. These results highlight the therapeutic potential of roscovitine as an anticancer drug, especially in tumours retaining a functional wild-type p53 pathway.

Segregation of nucleolar components coincides with caspase-3 activation in cisplatin-treated HeLa cells

We studied morphological changes of the nucleoli in HeLa cells treated with cisplatin and compared them with induction of markers of programmed cell death and TUNEL staining. We used different light microscopic nucleolar staining methods allowing us to visualize not only nucleolar proteins but also nucleolar RNA. Our results show predominantly compact, centrally localized nucleoli in intact control HeLa cells. In cisplatin-treated HeLa cells, we found an early onset of nucleolar segregation of proteins detected by argyrophilic nucleolar organizer regions and anti-nucleolar monoclonal antibody as well as an increased immunoreactivity for activated caspase-3 after 6 hours. Staining with Toluidine Blue and Methyl-green Pyronine revealed segregated nucleoli 12 hours after the treatment with cisplatin. TUNEL positivity in cisplatin-treated HeLa cells was accompanied by the aggregation of the argyrophilic proteins in the central portion of nucleus, disappearance of nucleolar RNA and shrinkage of the nucleus after 24 hours. Monitoring of the biochemical changes by immunoblotting revealed that activation of distinct caspases and degradation of their downstream protein substrates is executed in two phases. During an early apoptotic stage beginning 4.5 hours post treatment an activation of caspase-9 and caspase-3 was observed. This was accompanied by proteolytic cleavage of poly(ADP-ribose) polymerase-1 (PARP-1). The caspase-9 activation seems to be mediated by recruitment by the activating factor Apaf-1 because the increased accumulation of Apaf-1 and cytochrome C in cytosol preceded the generation of mature caspase-9 form. A second phase of apoptosis occurring between 10 and 15 hours post treatment was characterized by degradation of other nucleolar and nuclear proteins such as nuclear lamins, topoisomerase I and B23. In conclusion, remarkable segregation of nucleolar argyrophilic proteins, nucleolar RNA and a simultaneous activation of the cascade of caspases markedly preceded the TUNEL positivity in cisplatin-treated HeLa cells thereby substantiating the hypothesis that the nucleolus is a preferred target for caspase-3-dependent proteolysis in cisplatin-treated HeLa cells.