201 research outputs found

    Influence of 6 MV and 20 MV X-radiation dose rate on in vitro survive of the K-562 cell line

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    AbstractBackgroundAnalysis of the survival rate of cells after irradiation with a specified dose of X-radiation might be one of the basic foundations for assessment of biological implications of ionizing radiation. Investigation of the influence of X-radiation dose rate on cells was carried out in vitro using the SF2 test.AimThe aim of this study was to investigate the influence of X-radiation dose rate on the surviving fraction of the K-562 cell line for two photon energies of 6 MV and 20 MV.Materials/MethodsTo measure the cells' reaction to X-radiation of variable dose rate human leukaemic K-562 cells were used. In order to fulfil the main aim of the study, the cell line was subjected to irradiation at two different dose rates. Total dose applied at once was 2 Gy. A quantitative evaluation of cell survival rate was carried out at every step of the experiment using a clonogenic assay.ResultsHigh dose rate at the energy of 6 MV decreased the percentage of surviving cells to 23%, while lower dose rate decreased it only to 36%. A similar effect is observed at the energy of 20MV-namely at the higher dose rate the percentage of surviving cells is 18%, whereas at the lower one it is only 34%.ConclusionsThe experiment has shown that when using a lower dose rate, the biological effect of ionizing radiation is less pronounced. However, at a higher dose rate higher radiosensitivity of cells is observed

    Influence of 6 MV and 20 MV X-radiation dose rate on in vitro survive of the K-562 cell line

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    BackgroundAnalysis of the survival rate of cells after irradiation with a specified dose of X-radiation might be one of the basic foundations for assessment of biological implications of ionizing radiation. Investigation of the influence of X-radiation dose rate on cells was carried out in vitro using the SF2 test.AimThe aim of this study was to investigate the influence of X-radiation dose rate on the surviving fraction of the K-562 cell line for two photon energies of 6 MV and 20 MV.Materials/MethodsTo measure the cells' reaction to X-radiation of variable dose rate human leukaemic K-562 cells were used. In order to fulfil the main aim of the study, the cell line was subjected to irradiation at two different dose rates. Total dose applied at once was 2 Gy. A quantitative evaluation of cell survival rate was carried out at every step of the experiment using a clonogenic assay.ResultsHigh dose rate at the energy of 6 MV decreased the percentage of surviving cells to 23%, while lower dose rate decreased it only to 36%. A similar effect is observed at the energy of 20MV-namely at the higher dose rate the percentage of surviving cells is 18%, whereas at the lower one it is only 34%.ConclusionsThe experiment has shown that when using a lower dose rate, the biological effect of ionizing radiation is less pronounced. However, at a higher dose rate higher radiosensitivity of cells is observed

    Isolation and Structural Determination of Triterpenoid Glycosides from the Aerial Parts of Alsike Clover (Trifolium hybridum L.)

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    Five azukisapogenol glycosides (1−5) have been isolated from the aerial parts of alsike clover (Trifolium hybridum L.), and their structures were elucidated by combined spectroscopic, spectrometric (1D and 2D NMR; HRESIMS, ESI−MS/MS), and chemical methods. Three of them are new compounds and were identified as 3-O-[-α-L-arabinopyranosyl(1→2)]-β-Dglucuronopyranosyl azukisapogenol (1), 3-O-[-β-D-glucuronopyranosyl(1→2)-β-D-glucuronopyranosyl]-29-O-β-D-glucopyranosyl azukisapogenol (2), and 3-O-[-α-L-arabinopyranosyl(1→2)-β-D-glucuronopyranosyl]-29-O-β-D-glucopyranosyl azukisapogenol (3). The remaining two (4, 5) are known compounds but have not been previously described as saponins constituents of the genus Trifolium. Also, azukisapogenol is reported here as a triterpenoid aglycone for the first time in this genus. Finally, the main chemotaxonomic features that may be recognized as specific of Trifolium species were discussed

    Triterpenoid saponins from the aerial parts of Trifolium argutum Sol. and their phytotoxic evaluation

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    Four triterpenoid saponins (1–4) were isolated from the aerial parts of Trifolium argutum Sol. (sharptooth clover) and their structures were elucidated by comprehensive spectroscopic analysis, including 1D and 2D NMR techniques, mass spectrometry and chemical methods. Two of them are new compounds, characterized as 3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-galactopyranosyl-(1→2)-β-D-glucuronopyra- nosyl]-3β,24-dihydroxyolean-12-ene-22-oxo-29-oic acid (1) and 3-O-[β-D-galactopyranosyl-(1→2)- β-D-glucuronopyranosyl]-3β,24-dihydroxyolean-12-ene-22-oxo-29-oic acid (2). The occurrence of 3β,24-dihydroxyolean-12-ene-22-oxo-29-oic acid (melilotigenin) in its natural form is reported for the first time as a triterpenoid aglycone within Trifolium species. The phytotoxicity of compounds was evaluated on four STS at concentration 1 μM to 333 mM. Compound 1 was the most active, showing more than 60% inhibition on the root growth of L. sativa at the higher dose, with IC50 (254.1 μM) lower than that of Logran1 (492.6 μM), a commercial herbicide used as positive control. The structure–activity relationships indicated that both aglycones and glycosidic parts may influence the phytotoxicity of saponins

    Comparison of the Physicochemical Properties of Carboxylic and Phosphonic Acid Self-Assembled Monolayers Created on a Ti-6Al-4V Substrate

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    This study compared the tribological properties in nano- and millinewton load ranges of Ti-6Al-4V surfaces that were modified using self-assembled monolayers (SAMs) of carboxylic and phosphonic acids. The effectiveness of the creation of SAMs with the use of the liquid phase deposition (LPD) technique was monitored by the contact angle measurement, the surface free energy (SFE) calculation, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) measurements. The obtained results indicated that more stable and well-ordered layers, which were characterized by the lowest values of the coefficient of friction, adhesion, and wear rate, were obtained using phosphonic acid as a surface modifier. Based on the obtained results, it was found that the Ti-6Al-4V alloy modified by phosphonic acid would be the most advantageous for practical applications, especially in micro- and nanoelectromechanical systems (MEMS/NEMS)

    Cross-resistance to five glucocorticoids in childhood acute lymphoblastic and non-lymphoblastic leukemia samples tested by the MTT assay : preliminary report

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    In vitro antileukemic activity of five glucocorticoids and their cross-resistance pattern in childhood acute lymphoblastic and non-lymphoblastic leukemia were determined by means of the MTT assay in 25 leukemia cell samples of childhood acute leukemias. The equivalent antileukemic concentrations of the drugs tested were: 34 μM hydrocortisone (HC), 8 μM prednisolone (PRE), 1.5 μM methylprednisolone (MPR), 0.44 μM dexamethasone (DX) and 0.22 μM betamethasone (BET). In comparison with initial ALL cell samples, the relapsed ALL group was more resistant to PRE (38-fold, p = 0.044), DX (> 34-fold, p = 0.04), MPR (38-fold), BET (45-fold) and HC (33-fold). The AML cell samples were even more resistant to: PRE (>85-fold, p=0.001), DX (> 34-fold, p = 0.004), MPR (> 69-fold, p = 0.036), BET (> 69-fold, p = 0.038) and HC (54-fold, p = 0.059) when compared with ALL on initial diagnosis. A significant cross-resistance among all the glucocorticoids used was found. Only in some individual cases the cross-resistance was less pronounced

    In vitro activity of oxazaphosphorines in childhood acute leukemia : preliminary report

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    Glufosfamide (β-D-glucosyl-ifosfamide mustard) is a new agent for cancer chemotherapy. Its pharmacology is similar to commonly used oxazaphosphorines, but it does not require activation by hepatic cytochrome P-450 and preclinically demonstrates lower nephrotoxicity and myelosuppression than ifosfamide. The aim of the study was a comparison of the drug resistance profiles of glufosfamide and other oxazaphosphorines in childhood acute leukemias. Leukemic cells, taken from children with ALL on diagnosis (n = 41), ALL on relapse (n = 12) and AML on diagnosis (n= 13) were analyzed by means of the MTT assay. The following drugs were tested: glufosfamide (GLU), 4-HOO-ifosfamide (IFO), 4-HOO-cyclophosphamide (CYC) and mafosfamide cyclohexylamine salt (MAF). In the group of initial ALL samples median cytotoxicity values for GLU, IFO, CYC and MAF were 15.5, 33.8, 15.7 and 7.8 μM, respectively. In comparison with initial ALL samples, the relative resistance for GLU and IFO in relapsed ALL samples was 1.9 (p = 0.049) and 1.3 (ns), and in initial AML samples 31 (p < 0.001) and 5 (p = 0.001), respectively. All oxazaphosphorines presented highly significant cross-resistance. Glufosfamide presented high activity against lymphoblasts both on diagnosis and on relapse

    Jakość życia pacjentów z cukrzycą typu 2 po wdrożeniu insulinoterapii — badanie prospektywne

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    Introduction. In case of many patients with type 2 diabetes, despite deterioration of glycaemic control the moment of intensification of treatment is delayed because of barriers to initiating insulin therapy. The aim of the study was an evaluation of changes on health related quality of life (HRQoL) after intensification of the treatment among group of type 2 diabetes patients. Methods. The study involved 52 patients, treated so far by oral anti-diabetic drugs (OAD), for whom insulin was introduced. This group was exposed to 8 (± 1.5) months long observation. HRQoL was measured with questionnaires: EQ-5D, DQL-BCI and DSC-R. Results. After prospective observation, patients described significant improvement in QoL (EQ-VAS, DSC-R). DQL-BCI score remained unchanged, although detailed analysis showed improvement in treatment satisfaction, improvement in the level of knowledge about diabetes and increase in diabetes-related pain. Conclusions. Our study confirms the improvement in HRQoL after insulin therapy introduction. The results should encourage to early implementation of intensification of treatment.  Wstęp. W przypadku wielu pacjentów z cukrzycą typu 2, pomimo obserwowanego pogorszenia kontroli glikemii, dochodzi do opóźnienia intensyfikacji leczenia ze względu na bariery przed wdrożeniem insulinoterapii. Celem badania była ocena zmian w zakresie zależnej od zdrowia jakości życia wśród pacjentów z cukrzycą typu 2 po wdrożeniu insulinoterapii. Metody. Badaniem objęto 52 chorych z cukrzycą typu 2, dotychczas leczonych doustnymi lekami przeciwcukrzycowymi, u których zintensyfikowano leczenie poprzez dołączenie insuliny do dotychczas podawanych leków doustnych lub zastosowano monoterapię insuliną. Chorych poddano 8 (± 1,5)-miesięcznej obserwacji. Do pomiaru jakości życia zastosowano kwestionariusze: EQ-5D, DQL-BCI oraz DSC-R. Wyniki. Po okresie prospektywnej obserwacji stwierdzono istotną poprawę w zakresie jakości życia (EQ- -VAS, DSC-R). Wynik oceniany za pomocą kwestionariusza DQL-BCI nie uległ zmianie, jednakże szczegółowa analiza wykazała poprawę w zakresie satysfakcji z leczenia, wzrost poziomu wiedzy na temat cukrzycy, a także wzrost częstości odczuwania bólu związanego z leczeniem cukrzycy. Wnioski. Niniejsze badanie potwierdziło poprawę w zakresie zależnej od zdrowia jakości życia po wdrożeniu insulinoterapii, co powinno stanowić zachętę do podejmowania wczesnej intensyfikacji leczenia u pacjentów z pogorszeniem kontroli glikemii
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