Drug-induced trafficking of p-glycoprotein in human brain capillary endothelial cells as demonstrated by exposure to mitomycin C.

P-glycoprotein (Pgp; ABCB1/MDR1) is a major efflux transporter at the blood-brain barrier (BBB), restricting the penetration of various compounds. In other tissues, trafficking of Pgp from subcellular stores to the cell surface has been demonstrated and may constitute a rapid way of the cell to respond to toxic compounds by functional membrane insertion of the transporter. It is not known whether drug-induced Pgp trafficking also occurs in brain capillary endothelial cells that form the BBB. In this study, trafficking of Pgp was investigated in human brain capillary endothelial cells (hCMEC/D3) that were stably transfected with a doxycycline-inducible MDR1-EGFP fusion plasmid. In the presence of doxycycline, these cells exhibited a 15-fold increase in Pgp-EGFP fusion protein expression, which was associated with an increased efflux of the Pgp substrate rhodamine 123 (Rho123). The chemotherapeutic agent mitomycin C (MMC) was used to study drug-induced trafficking of Pgp. Confocal fluorescence microscopy of single hCMEC/D3-MDR1-EGFP cells revealed that Pgp redistribution from intracellular pools to the cell surface occurred within 2 h of MMC exposure. Pgp-EGFP exhibited a punctuate pattern at the cell surface compatible with concentrated regions of the fusion protein in membrane microdomains, i.e., lipid rafts, which was confirmed by Western blot analysis of biotinylated cell surface proteins in Lubrol-resistant membranes. MMC exposure also increased the functionality of Pgp as assessed in three functional assays with Pgp substrates (Rho123, eFluxx-ID Gold, calcein-AM). However, this increase occurred with some delay after the increased Pgp expression and coincided with the release of Pgp from the Lubrol-resistant membrane complexes. Disrupting rafts by depleting the membrane of cholesterol increased the functionality of Pgp. Our data present the first direct evidence of drug-induced Pgp trafficking at the human BBB and indicate that Pgp has to be released from lipid rafts to gain its full functionality

Aktywny układ cewka-rdzeń jako część podpory bryły sztywnej oraz jego wpływ na drgania

In the paper we took into account the influence of the actively controlled coil dampers introduced into vibrating body supports. The body was considered as moving mass centre of 3-degrees-of-freedom. Investigated object was located on four supports. Body dynamics was described by means of Newton and Euler equations. Body vibrations were caused by statically unbalanced rotor located inside the object. In the control system the coils with the movable cores were used as the executive elements (controllable stiffness). In the closed-loop system the PD regulators were introduced into each support. The coils current was controlled by means of pulse width modulated (PWM) generators. In the article we presented the time characteristics and the frequency responses of the investigated system. Differences between open (non-controlled) and closed-loop (actively controlled) system were shown. Responses to the rotor perturbations were also calculated. Finally, the main advantages and disadvantages of the proposed solution were discussed. The further work directions were also indicated.W niniejszej pracy rozpatrzono wpływ aktywnie kontrolowanych cewkowych tłumików drgań umieszczonych w podporach drgającej bryły. Badana bryła została opisana jako punkt materialny o trzech stopniach swobody. Badany obiekt umieszczono na czterech podporach. Dynamiką ciała opisano równaniem Newtona i Eulera. Drgania bryły były wywołane statycznie niewyważonym wirnikiem umieszczonym we wnętrzu bryły. W układzie sterowania, jako elementy wykonawcze wykorzystano cewki z ruchomymi rdzeniami. Do każdej z podpór wprowadzono zamkniętą pętlę sterowania z regulatorem proporcjonalno-różniczkującym (PD). Prąd w cewkach był regulowany za pomocą generatorów impulsowych o zmiennym wypełnieniu (PWM). W niniejszej pracy przedstawiono charakterystyki czasowe oraz odpowiedzi częstotliwościowe badanego układu. Pokazano różnice pomiędzy układem otwartym (bez sterowania) i zamkniętym (sterowanym aktywnie). Wyznaczono również odpowiedzi układu na zaburzenia wywoływane przez wirnik. W pracy omówiono główne zalety i wady proponowanych cewkowych tłumików drgań. Wskazano również kierunki przyszłych badań

A ground control station for the UAV flight simulator

In the paper implementation of a ground control station for UAV flight simulator is shown. The ground control station software is in cooperation with flight simulator, displaying various aircraft flight parameters. The software is programmed in C++ language and utilizes the windows forms for implementing graphical content. One of the main aims of the design of the application was to simplify the interface, simultaneously maintaining the functionality and the eligibility. A mission can be planned and monitored using the implemented map control supported by waypoint list

Computationaly simple obstacle avoidance control law for small unmanned aerial vehicles

The investigations of the system which allow to avoid obstacles by the unmanned aerial vehicles (UAV) are presented in the paper. The system is designed to enable the full autonomous UAV flight in an unknown environment. As an information source about obstacles digital camera was used. Developed algorithm uses the existing relations between the imaging system and the parameters read from the UAV autopilot. Synthesis of the proposed obstacle avoidance control law was oriented for computational simplicity. Presented algorithm was checked during simulation studies and in-flight tests

Microscopic Examination of Cold Spray Cermet Sn+In 2

Low-pressure cold spraying is a newly developed technology with high application potential. The aim of this study was to investigate potential application of this technique for producing a new type of transparent conductive oxide films target. Cold spraying technique allows the manufacture of target directly on the backing plate; therefore the proposed sputtering target has a form of Sn+In2O3 coating sprayed onto copper substrate. The microstructure and properties of the feedstock powder prepared using three various methods as well as the deposited ones by low-pressure cold spraying coatings were evaluated, compared, and analysed. Produced cermet Sn+In2O3 targets were employed in first magnetron sputtering process to deposit preliminary, thin, transparent conducting oxide films onto the glass substrates. The resistivity of obtained preliminary films was measured and allows believing that fabrication of TCO (transparent conducting oxide) films using targets produced by cold spraying is possible in the future, after optimization of the deposition conditions

A single-centre experience of the implementation of adrenal vein sampling procedure: the impact on the diagnostic work-up in primary aldosteronism

BACKGROUND: Primary aldosteronism is one of the most common causes of secondary hypertension. Adrenal vein sampling (AVS) remains a "gold standard" procedure in differentiation between unilateral (adenoma) and bilateral (hyperplasia) disease. AIM: The aim of this study was to present our single-centre experience in establishing and implementating the AVS procedure. METHODS: All patients had primary aldosteronism confirmed in a salt-infusion test. AVS was performed sequentially during a continuous intravenous infusion of cosyntropin and was preceded by multislice contrast-enhanced computed tomography (CT) examination of adrenal glands performed a few weeks before AVS in the majority of patients. AVS was regarded as successful if the ratio of each adrenal vein cortisol to inferior vena cava cortisol levels (selectivity index [SI]) was higher than 3.0. In the case of failure, a second attempt was considered in a few weeks. Patients were divided into four groups according to the order of the procedure by quartiles. RESULTS: Between 31 May, 2012 and 5 May, 2016, AVS was performed in 124 patients (69% males, aged 55.3 +/- 10.3 years) and was successful in 120 (96.8%) patients. All failed cases were due to the failure of cannulation of the right adrenal vein. The first-attempt success rate was 94.3% (117 of 124 patients) and increased from 83.9% in the first 31 patients to 100% in the last 31 patients. Similarly, the overall success rate increased from 93.5% to 100%. The right SI was significantly higher than the left one (26.4 vs. 11.0, p < 0.0001). Both indices did not differ across quartiles of patients. No complications occurred during the procedure. CONCLUSIONS: The AVS procedure, preceded by adrenal CT, may be implemented into daily diagnostic practice safely with an excellent success rate