Swelling of biocompatible polymer films.

The incorporation of drugs into phosphorylcholine (PC) polymers coated onto coronary stent surfaces is one potential method of treatment for reducing restenosis, the reclosure of the artery after angioplasty treatment. This work on the characterisation of the swelling performance of thin PC polymer films represents a further extension of the study on biocompatible polymers. The broad aim of this work is to relate the PC polymer structure and film processing conditions to their swelling, drug loading and release kinetics. As the two highly sensitive and powerful techniques in film structure determination, both ellipsometry and neutron reflection have proved to be useful in characterising PC polymer films and drug release processes. Following an established ellipsometry measurement method, a two stage process consisting of diffusion and relaxation has been observed during the PC film swelling: this suggests an anomalous mechanism, and this performance is well described by the coupled diffusion and relaxation model developed by Berens and Hopfenberg. Furthermore, the swelling of PC polymer films was investigated as a function of cross-linking, annealing temperature, chemical composition, hydrophilic/hydrophobic ratios, film thickness and environmental conditions by ellipsometry measurements, and their effects on swelling kinetics well quantified. The structures of the PC polymer films (PC100B) with cross-linking groups have been further characterised by neutron reflection. The segregation of hydrophobic and hydrophilic domains was found in the PC films with different dimensions. The PC100B with deuterated dodecyl chains was used to highlight the interfacial structures of the PC films. The hydrophilic segments, including phosphorylcholine groups and hydroxypropyl groups, are preferentially adsorbed at the polymer/substrate interface. The hydrophobic dodecyl chains are expelled away from the silicon oxide surface. The main part of PC100B films is the middle uniform region with 40% of water in the sample annealed at 150°C, and 55% of water in the sample annealed at 50°C. The combination of the ellipsometry results and the drug release profiles from UV measurements indicates that the drug release pattern is strongly affected by the film swelling kinetics when the drug molecules and polymer matrix interact weakly. Otherwise, a strong interaction between the drug and the polymer will dominate the drug release behaviour from the PC polymer films

Mechanical thrombectomy in acute stroke – Five years of experience in Poland

Objectives Mechanical thrombectomy (MT) is not reimbursed by the Polish public health system. We present a description of 5 years of experience with MT in acute stroke in Comprehensive Stroke Centers (CSCs) in Poland. Methods and results We retrospectively analyzed the results of a structured questionnaire from 23 out of 25 identified CSCs and 22 data sets that include 61 clinical, radiological and outcome measures. Results Most of the CSCs (74%) were founded at University Hospitals and most (65.2%) work round the clock. In 78.3% of them, the working teams are composed of neurologists and neuro-radiologists. All CSCs perform CT and angio-CT before MT. In total 586 patients were subjected to MT and data from 531 of them were analyzed. Mean time laps from stroke onset to groin puncture was 250±99min. 90.3% of the studied patients had MT within 6h from stroke onset; 59.3% of them were treated with IV rt-PA prior to MT; 15.1% had IA rt-PA during MT and 4.7% – emergent stenting of a large vessel. M1 of MCA was occluded in 47.8% of cases. The Solitaire device was used in 53% of cases. Successful recanalization (TICI2b–TICI3) was achieved in 64.6% of cases and 53.4% of patients did not experience hemorrhagic transformation. Clinical improvement on discharge was noticed in 53.7% of cases, futile recanalization – in 30.7%, mRS of 0–2 – in 31.4% and mRS of 6 in 22% of cases. Conclusion Our results can help harmonize standards for MT in Poland according to international guidelines

Methodology for design of active dampers of beams

M.S.Stephen L. Dickerso

Stezenie wybranych interleukin grupy Th1 i Th2 w surowicy krwi matek w porodzie przedwczesnym i porodzie o czasie.

The immune system is responsible for the development of a typical pregnancy, including the induction of labor. Objectives: The aim of our study was to determine the concentration of maternal serum Th1 and Th2 cytokines, which have opposite biological effects, in preterm and term labor. Material and methods: 88 patients were divided into four groups: normal pregnancy (n=20), threatened preterm labor (n=22), preterm delivery (n=24) and term delivery (n=22). Maternal serum interleukins 1,6,8 and 10 were measured with ELISA R&D Systems kits (USA). In all patients CRP was estimated and the blood specimen were analyzed using an automated hematology cell analyzer. Results: Women in term and preterm delivery group had significantly higher mean IL-β, IL-6 and IL-8 concentrations than patients in normal pregnancy and these with threatened preterm labor. In addition, the highest WBC and CRP concentration were found in women in preterm delivery compared with other groups. Conclusions: Maternal serum Th1 cytokines concentrations increase in preterm and term delivery. Determination of maternal serum IL-6, IL-8 and IL-10 may play an essential role in estimations of the preterm labor risk.Układ immunologiczny jest odpowiedzialny za rozwój fizjologicznej ciąży, włączając w to rozpoczęcie porodu. Cel pracy: Za cel pracy przyjęto ocenę stężeń cytokin, o teoretycznie przeciwstawnych efektach działania biologicznego grup Th1 i Th2, w surowicy krwi rodzących przedwcześnie i rodzących o czasie. Materiał i metody: Badaniami objęto 88 pacjentek, które podzielono na 4 grupy: 20 w ciąży fizjologicznej, 22 z zagrażającym porodem przedwczesnym, 24 które urodziły przedwcześnie oraz 22 które urodziły o czasie. W każdym przypadku pobrano krew do badania i oznaczano stężenia interleukin 1, 6, 8 i 10 w surowicy krwi metoda ELISA „R&D Systems” (USA). Ponadto wykonywano morfologię oraz stężenie białka CRP. Wyniki: Stężenia IL-1β, IL-6 oraz IL-8 byΠy istotnie wyszce w grupach kobiet rodzących przedwcześnie i rodzących o czasie, w porównaniu do grup ciąż o przebiegu fizjologicznym i z zagrażającym porodem przedwczesnym. Stężenie IL-10 było najwyższe w surowicy kobiet z zagrażającym porodem przedwczesnym. Stwierdzono również wyższą liczbę leukocytów oraz wyższe stężenie białka CRP w grupie rodzących przedwcześnie w porównaniu do pozostałych badanych grup. Wnioski: Dokonany poród wiązał się z wyższymi stężeniami cytokin grupy Th2. łączne oznaczanie w surowicy krwi matki IL-6, IL-8 oraz IL-10 może być czynnikiem wspomagającym prognozowanie ryzyka wystąpienia porodu przedwczesnego

Mechanical thrombectomy in acute stroke : five years of experience in Poland

Objectives: Mechanical thrombectomy (MT) is not reimbursed by the Polish public health system. We present a description of 5 years of experience with MT in acute stroke in Comprehensive Stroke Centers (CSCs) in Poland. Methods and results: We retrospectively analyzed the results of a structured questionnaire from 23 out of 25 identified CSCs and 22 data sets that include 61 clinical, radiological and outcome measures. Results: Most of the CSCs (74%) were founded at University Hospitals and most (65.2%) work round the clock. In 78.3% of them, the working teams are composed of neurologists and neuro-radiologists. All CSCs perform CT and angio-CT before MT. In total 586 patients were subjected to MT and data from 531 of them were analyzed. Mean time laps from stroke onset to groin puncture was 250 99 min. 90.3% of the studied patients had MT within 6 h from stroke onset; 59.3% of them were treated with IV rt-PA prior to MT; 15.1% had IA rt-PA during MT and 4.7% - emergent stenting of a large vessel. M1 of MCA was occluded in 47.8% of cases. The Solitaire device was used in 53% of cases. Successful recanalization (TICI2b–TICI3) was achieved in 64.6% of cases and 53.4% of patients did not experience hemorrhagic transformation. Clinical improvement on discharge was noticed in 53.7% of cases, futile recanalization - in 30.7%, mRS of 0–2 - in 31.4% and mRS of 6 in 22% of cases. Conclusion: Our results can help harmonize standards for MT in Poland according to international guideline