Tomasz Urbanek

Rapamycin induces of protective autophagy in vascular endothelial cells exposed to oxygen-glucose deprivation.

The protective potential of rapamycin has been reported in a few experimental models of brain ischemia, both in vivo and in vitro. Although the precise cellular processes underlying the neuroprotective effects of rapamycin in experimental models of stroke remain unknown, the current experimental data suggest that the mechanism of action of the drug may result from the mTOR-mediated autophagy induction. However, it is unclear whether the activation of autophagy acts as a pro-death or pro-survival factor in vascular endothelial cells in ischemic brain damage. It seems to be very important, since stroke affects not only neurons and astrocytes but also microvessels. In the present study, we used human umbilical vein endothelial cells (HUVEC) subjected to ischemia-simulating conditions (combined oxygen and glucose deprivation, OGD) for 6h to determine potential effect of rapamycin-induced autophagy on HUVEC damage. The drug at concentrations of 100 and 1000nM increased the expression of Beclin 1 and LC3-II together with a significant increase in the p62 degradation in ischemic HUVEC. Treatment with rapamycin in OGD significantly increased the cell viability, indicating that the drug exerts cytoprotective effect. The inhibition of Beclin 1 by siRNAs significantly attenuated the expression of autophagy-related proteins and reduced HUVEC viability following OGD and rapamycin treatment. Our findings demonstrated that toxicity of simulated ischemia conditions were enhanced in HUVEC when autophagy was blocked, and that rapamycin effectively prevented OGD-evoked damage by induction of protective autophagy via inhibition of the mTOR pathway.

Neck duplex Doppler ultrasound evaluation for assessing chronic cerebrospinal venous insufficiency in multiple sclerosis patients

Introduction: Recent clinical studies have suggested a relationship between multiple sclerosis (MS) and the occurrence of pathological changes in the jugular, vertebral and azygous veins that result in abnormal blood outflow from the brain and the spinal cord. Together, these pathological changes have been designated chronic cerebrospinal venous insufficiency (CCSVI). The aim of the present study was to evaluate the usefulness of duplex Doppler ultrasound in the evaluation of central nervous system venous outflow disturbances in patients suffering from MS. Methods: We examined 181 patients with MS, diagnosed on the basis of the McDonald criteria, and 50 healthy volunteer controls. All patients underwent Doppler ultrasound examination of the internal jugular veins (IJV) and vertebral veins (VVs). The presence of outflow disturbances and morphological abnormalities were evaluated. Results: Pathological changes in the extracranial jugular veins were diagnosed in 148/181 MS patients (82%) and 7/50 control group volunteers (14%). The following abnormalities in the MS group were revealed: the presence of a reflux in the IJVs and/or VVs (54%), narrowing (54%), a complete block in the flow through the IJV (10%) and an abnormal postural control of the cerebral outflow route (25%). These particular pathologies were of statistical significance in the MS group compared with the control group. This study also revealed a correlation between the occurrence of inverted flow in patients in a sitting position and chronic progressive MS (P = 0.0033). Conclusions: The examinations undertaken indicate a possible connection between MS and CCSVI. The widely accessible and highly sensitive and specific Doppler ultrasound test may be useful for revealing, and preliminary analysis of, CCSVI pathologies.

Superoxide dismutase 1 and glutathione peroxidase 1 are involved in the protective effect of sulodexide on vascular endothelial cells exposed to oxygen-glucose deprivation.

Sulodexide (SDX) is widely used in the treatment of both arterial and venous thrombotic disorders. In addition to its recognized antithrombotic action, SDX has endothelial protective potential, which is independent of the coagulation/fibrinolysis system. However, the detailed molecular mechanisms of the endothelioprotective action of the drug are still unresolved. The aim of the present study was to determine whether treatment with SDX at concentrations of 0.125-0.5 lipase releasing unit (LRU)/ml have on the expression and activity of antioxidant enzymes in ischemic endothelial cells and how these effects might be related to the antiapoptotic properties of SDX. In the present study, human umbilical vein endothelial cells (HUVECs) were subjected to ischemia-simulating conditions (combined oxygen and glucose deprivation, OGD) for 6h to determine the protective effects of SDX. SDX (0.25 and 0.5LRU/ml) in OGD significantly increased the cell viability and prevented mitochondrial depolarization in the HUVECs. Moreover, SDX protected the HUVECs against OGD-induced apoptosis. At concentrations of 0.25 and 0.5LRU/ml, the drug increased both superoxide dismutase 1 (SOD1) and glutathione peroxidase 1 (GPx1) mRNA/protein expression together with a significant attenuation of oxidative stress in ischemic HUVECs. Our findings also demonstrate that an increase in both SOD and GPx activity is involved in the protective effect of SDX on ischemic endothelial cells. Altogether, these results suggest that SDX has a positive effect on ischemia-induced endothelial damage because of its antioxidant and antiapoptotic properties.

Astrocytes in ischemic stroke – a potential target for neuroprotective strategies

Ischemic stroke is one of the leading causes of adult death and disability worldwide. Present applied therapeutic strategies do not give satisfactory results. It is often emphasized that pharmacological actions aimed at reducing the area of ischemic brain injury should protect astrocytes forming together with neurons and the endothelium neurovascular unit. Astrocytes contribute importantly to proper neuronal function during both physiological and pathological conditions. In ischemic stroke, astrocytes are involved in regulation of water and ion homeostasis, cerebral blood flow, maintenance of the blood-brain barrier, and control of the extracellular level of glutamate, as well as being a source of neuroprotectants. On the other hand, astrocytes may also contribute to enlarged ischemic area due to their participation in inflammatory processes and production of potential neurotoxic substances. Herein we review experimental and clinical data concerning adaptive and pathological roles of astrocytes during both early and late phases of ischemia. Especially, we emphasize specific features of astrocytes that might become a potential target of therapeutic strategies for ischemic stroke.

Effects of Intermittent Pneumatic Compression on Reduction of Postoperative Lower Extremity Edema and Normalization of Foot Microcirculation Flow in Patients Undergoing Arterial Revascularization

Background In patients with chronic leg ischemia, the beneficial effect of arterial revascularization can be significantly decreased due to postoperative leg swelling. The aim of this study was to assess the effects of intermittent pneumatic compression (IPC) on skin flow normalization in patients undergoing revascularization procedures due to chronic leg ischemia. Material/Methods We evaluated 116 patients with chronic leg ischemia. The patients were divided into groups according to the performed treatment (endovascular or surgical) and implementation of IPC postoperatively. The leg edema assessment and microcirculation flow assessment were performed pre- and postoperatively, using percutaneous O2 pressure (TcpO2), cutaneous blood perfusion (CBP) measurements, and skin flow motion assessment. Results In patients who did not receive IPC, a decrease in CBP value was observed in the 1st postoperative assessment. Among patients receiving IPC, the CBD value increased at the 1st and 2nd postoperative measurements, especially in the surgical group. The lowest TcpO2 values were observed in by-pass surgery group without IPC postoperatively. Conclusions The benefits of the by-pass procedure in patients with leg ischemia can be significantly reduced by postoperative edema. Among patients with postoperative leg edema, local tissue blood perfusion can be improved by the use of IPC, which can result in decreased local leg swelling, as well as improved skin blood perfusion and TcpO2.

Tension-Free Vaginal Tape, Transobturator Tape, and Own Modification of Transobturator Tape in the Treatment of Female Stress Urinary Incontinence: Comparative Analysis

Introduction. This study is a comparative evaluation of the TVT, TOT, and our own modification of TOT (mTOT) in the treatment of female stress urinary incontinence from a single center experience. Material and Methods. The study was conducted on 527 patients with SUI diagnosed on the basis of urodynamic studies. They were divided into three groups—TVT: n = 142, (TOT): n = 129, and mTOT: n = 256. All of the patients underwent evaluation at 1, 3, and 6 months after surgery. Results were statistically analysed and compared. Results. Objective and subjective effectiveness after the surgery were not significantly different in the study groups and ranged from 90.1% to 96.4%. Mean surgery time was 32.3, 28.2, and 26.4 in the TVT, TOT, and mTOT, respectively. Mean hospitalization time was 2.51 days. Mean catheter maintenance time was significantly higher in the TVT than in other groups. In the TVT group total incidence of complications was 13.4%, and it was significantly higher than that in TOT and mTOT (9.3% and 8.6%, resp.). Conclusions. TVT, TOT, and mTOT are highly effective and safe methods in the treatment of SUI. There are no differences in the efficacy between the methods with a little higher percentage of complications in the TVT group.

Assessment of cerebral embolism and vascular reserve parameters in patients with carotid artery stenosis

AIM Carotid artery stenosis can result in the brain tissue injury related to the intracranial aterial flow disturbances as well as microembolic complications. The choice of the proper therapy in patients with carotid artery stenosis, especially asymptomatic, remains still a significant clinical problem. The study aim was an assessment of the cerebral embolism and brain vascular reserve parameters in patients with carotid artery stenosis regarding the occurrence of the clinical symptoms, the degree of stenosis as well as plaque morphology. METHODS The study included 60 patients, with internal carotid artery stenosis. The degree of stenosis, the atherosclerotic plaque surface and morphology were assessed by the means of Duplex Doppler ultrasound. Cerebrovascular reactivity (vasomotor reactivity reserve test and Breath Holding Index) and monitoring of the microembolic signals (MES) were assessed with transcranial Doppler ultrasound examination (TCD). RESULTS The vasoreactivity parameters were significantly lower in the group of patients with stenosis ≥70% and in patients with ulcerations on the plaque surface. Microembolic signals were recorded significantly more often in symptomatic patients; in patients with stenosis ≥70%; in patients with ulcerations on the plaque surface and those with hypoechogenic plaque structure. CONCLUSIONS Microembolic signals in patients with symptomatic carotid stenosis are one of the ultrasound features of unstable carotid stenosis. Worse reactivity parameters of the cerebral arteries are associated with the presence of a large degree of carotid artery stenosis.

Sapheno-femoral junction pathology: molecular mechanism of saphenous vein incompetence.

A molecular mechanism responsible for varicose vein occurrence was investigated. The role of potential cell cycle regulator p21 and programmed cell death in the pathology leading to the proximal long saphenous vein (LSV) incompetence was investigated. Proximal LSV specimens were obtained from 40 patients with primary varicose veins who had undergone crossectomy. The expression of the p21, p53, and fas encoding genes was investigated by the means of real-time RT-QPCR. Immunostaining for gene product presence, proliferating cell nuclear antigen (PCNA), and apoptotic cells (TUNEL assay) was carried out. The results were compared to the control healthy vein specimens and correlated with pathologic examination findings (of the valve and vein structure). A significant increase in p21, p53, and fas mRNA expression were reported in the proximal incompetent veins. The expression of p21 correlated with expression of p53 (r = 0.658; p<0.05) and negative correlation between media apoptotic index and p21 mRNA expression was found (r = -0.493; p<0.05). Decrease in the muscular component within the media and disturbances of the local structure in the incompetent LSVs were reported. Fas overexpression did not correlate with p53 expression level and did not correlate with apoptotic cell number in the respective vein layers. PCNA-positive cells were present more frequently in the media of the control veins, especially in young subjects. Apoptosis downregulation, cell cycle inhibition and smooth muscle cell hypertrophy are important factors influencing vein wall disturbances related to sapheno-femoral junction incompetence.

The Hemodynamics of Blood Flow through the Internal Jugular Veinsafter CCSVI Endovascular Treatment and its Impact on the Quality of Lifein Patients with Chronic Cerebrospinal Venous Insufficiency

Objectives: The aim of the study was to compare pre- and post-operative blood flow through the internal jugular veins (IJVs) in patients with multiple sclerosis and chronic cerebrospinal venous insufficiency, who were subjected to endovascular treatment. The results were correlated with respect to changes in the quality of life. Methods: 144 MS patients underwent endovascular treatment of the IJVs. The blood flow through the IJVs was assessed by the means of the Doppler ultrasonography. The clinical neurological evaluation was based on the various diagnostic tools (scales). The assessment of the blood flow through the IJVs and an evaluation of the quality of life changes were performed before surgery, and at 1, 3 and 6 months after surgery. Results: A statistically significant increase in the blood flow through the IJVs was identified on both sides during all three postoperative controls. The relationship between the IJV flow changes and the parameters related to the quality of life assessment, a statistically significant positive correlation between the flow improvement in the right IJV and Multiple Sclerosis Impact Scale, as well as Fatigue Severity Scale scores, were found. For the remaining evaluated scales (Expanded Disability Status Scale, Heat Intolerance Scale and Epworth Sleepiness Scale), as well for the flow in the left IJV, there were no statistically significant correlations confirmed. Conclusion: Despite a significant improvement in the blood flow through the IJVs after endovascular interventions on the IJVs in CCSVI patients, it has not demonstrated that hemodynamic changes improve the quality of life in MS patients.

The influence of atmospheric pressure on aortic aneurysm rupture — is the diameter of the aneurysm important?

BACKGROUND The rate of aortic aneurysm rupture correlates with the aneurysms diameter, and a higher rate of rupture is observed in patients with larger aneurysms. According to the literature, contradictory results concerning the relationship between atmospheric pressure and aneurysm size have been reported. AIM In this paper, we assessed the influence of changes in atmospheric pressure on abdominal aneurysm ruptures in relationship to the aneurysms size. METHODS The records of 223 patients with ruptured abdominal aneurysms were evaluated. All of the patients had been admitted to the department in the period 1997-2007 from the Silesia region. The atmospheric pressures on the day of the rupture and on the days both before the rupture and between the rupture events were compared. The size of the aneurysm was also considered in the analysis. RESULTS There were no statistically significant differences in pressure between the days of rupture and the remainder of the days within an analysed period. The highest frequency of the admission of patients with a ruptured aortic aneurysm was observed during periods of winter and spring, when the highest mean values of atmospheric pressure were observed; however, this observation was not statistically confirmed. A statistically non-significant trend towards the higher rupture of large aneurysms (> 7 cm) was observed in the cases where the pressure increased between the day before the rupture and the day of the rupture. This trend was particularly pronounced in patients suffering from hypertension (p = 0.1). CONCLUSIONS The results of this study do not support the hypothesis that there is a direct link between atmospheric pressure values and abdominal aortic aneurysm ruptures.