Functional characterization of Cytoplasmic Polyadenylation Element Binding proteins in the developing and diseased brain

Gliomas are the most common primary brain tumors with aggressive progression and devastating prognosis. Therefore identification of new therapeutic and diagnostic factors is necessary to improve the dramatic situation of glioma patients. Thus far, cancer-related genes were thoroughly analyzed by transcript-based microarrays (van den Boom et al., 2003; Phillips et al., 2006; Rickman et al., 2001). However, recent research shed light on the importance of post-transcriptional modifications of mRNAs that alter gene expression under physiological conditions, but also gives rise to the pathology of gliomas. The main goal of the present study was to investigate CPEB expression in human glioma specimens. CPEBs are auxiliary regulators associating with consensus sequences present in 3’UTRs of mRNAs, which activate or repress their translation. Via this mechanism CPEBs regulate essential cellular processes, such as development (Groisman et al., 2002; Novoa et al., 2010), memories formation (Theis et al., 2003) and progression of cancer (Ortiz-Zapater et al., 2012). In the current work aberrant CPEB expression was found to be a frequent phenomenon in both, low- and high-grade gliomas. Decreased CPEB1 expression was associated with the rising grade of tumor malignancy, suggesting it being a putative tumor suppressor. One of the mechanisms potentially underlying transcriptional silencing of cancer-related genes might be DNA methylation. However, despite hypermethylation of the CPEB1 gene, DNA methylation proved not to be directly responsible for its downregulation in gliomas. Thus, the underlying mechanism remains elusive. Abundant expression of CPEB 2-4 was detected in numerous human glioma specimens. CPEB2 expression in endothelial tumor cells suggested that CPEB2-mediated protein synthesis takes place in the close proximity of blood vessels within tumor tissue. On the other hand, CPEB4 expression appeared to support tumorigenic properties by its putative entanglement into local protein synthesis in transformed cells. Intriguingly, only CPEB3 expression was correlated positively with tumor progression. Phosphorylation of CPEB3 within the alternatively spliced region was negatively correlated with tumor malignancy. The loss of CPEB3 activity in high-grade gliomas is likely caused by the expression of alternatively spliced variants. This suggests that a substantial part of the CPEB3 in GBM specimens does not undergo phosphorylation and indicates phosphorylation to be a biologically important mechanism regulating CPEB3 activity. Furthermore, a significant correlation between CPEB3 activity and survival was observed in less aggressive low-grade astrocytomas considered to be sGBM precursors. Consequently, CPEB3 may be considered as an attractive therapeutic target in gliomas. To further investigate the relationship between CPEB activity, growth properties and cancer-relevant parameters an in vitro overexpression study was performed. This revealed a striking link between CPEB1, enhanced apoptotic activity and enhanced migration. One explanation could be that through rapid changes in the cytoskeleton of migrating cell the chance of mistakes rises, turning GBM cells towards an apoptotic pathway. On the other hand, CPEB2 overexpression decreased apoptotic activity, enhanced migration and by this additionally strengthened the cancerous properties of the cells. Importantly, CPEBs were also found to regulate various cancer pathways, including the TGF-β signaling cascade. However, further studies are needed to fully understand the interaction between CPEBs translational control and the pathophysiology of cultured GMB cells and human gliomas. Finally, the study revealed that CPEB2 is expressed in different cellular populations, brain regions, and stages of development, which indicates that this protein plays an important role in regulation of local protein synthesis, synaptic plasticity, and neuronal morphogenesis. The present study does not only increase our understanding of the function of CPEBs but also shows the importance of post-transcriptional modifications of mRNAs as a pathophysiological mechanism in gliomas and potentially other cancers. Therefore, these results may serve as a valuable basis for the identification of new therapeutic and diagnostic factors in cancer treatment

Time-averaged electronic speckle pattern interferometry in the presence of ambient motion. Part I: Theory and experiments

An electronic speckle pattern interferometer is introduced that can produce time-averaged interferograms of harmonically vibrating objects in instances where it is impractical to isolate the object from ambient vibrations. By subtracting two images of the oscillating object, rather than the more common technique of subtracting an image of the oscillating object from one of the static objects, interferograms are produced with excellent visibility even when the object is moving relative to the interferometer. This interferometer is analyzed theoretically and the theory is validated experimentally

Microfabricated Formaldehyde Gas Sensors

Formaldehyde is a volatile organic compound that is widely used in textiles, paper, wood composites, and household materials. Formaldehyde will continuously outgas from manufactured wood products such as furniture, with adverse health effects resulting from prolonged low-level exposure. New, microfabricated sensors for formaldehyde have been developed to meet the need for portable, low-power gas detection. This paper reviews recent work including silicon microhotplates for metal oxide-based detection, enzyme-based electrochemical sensors, and nanowire-based sensors. This paper also investigates the promise of polymer-based sensors for low-temperature, low-power operation

Natural and enhanced bioattenuation potential of an aquifer contaminated by mixed wastes.

Intrinsic bioremediation is scientifically valid for controlling fuel-contaminated aquifers, but its potential to remediate chlorinated solvents is less understood. This study used field and laboratory methods to assess bioattenuation potential in a shallow unconfined aquifer contaminated by mixed wastes from fire training activities at Wurtsmith Air Force Base in Michigan. Biogeochemical characterization of a cross-sectional plume transect revealed spatial and temporal heterogeneities in contaminant composition, microbial community structure, and terminal electron accepting processes (TEAPs). Over one year, TEAPs evolved from methanogenesis to sulfate reduction, with corresponding shifts in microbial phylogeny. Chlorinated solvent and fuel biodegradation evidence included methane, carbon dioxide, aromatic acids, cis-dichloroethylene, and vinyl chloride accumulation in groundwater. However, cell numbers were low outside the highly-contaminated capillary fringe, and cells were small and appeared nutritionally stressed. Furthermore, concentrations of alkylbenzenes (570 mg/kg), chloroalkenes, and chlorobenzenes (3000 m g/kg) have remained essentially constant during the past ten years, despite dynamic redox zonation throughout the plume. Laboratory biodegradation assays for sediments from discrete redox zones supported field observations. Toluene and trichloroethylene mineralization did not exceed 5%, regardless of sediment origin. Dechlorination intermediates accumulated only in methanogenic-zone soil. Methane and carbon dioxide were produced from mineralization of contaminants other than toluene and trichloroethylene in all anaerobic microcosms after 200 days. Neither purged nor contaminated groundwater was toxic to pure toluene-oxidizing or methanotrophic cultures, nor was xylene at field concentrations. Nitrogen and phosphorus amendments had little effect on microbial activity, but inoculum density influenced toluene degradation by Pseudomonas putida. At low initial densities (103--107 CFU/mL), groundwater impeded toluene degradation compared to media, but this behavior was reversed above 108 CFU/mL, possibly from culture history or nutrient depletion during growth, rather than from variable enzyme induction. This study demonstrated that chlorinated solvent bioattenuation in mixed waste environments may be overestimated without laboratory-measured biodegradation kinetics. Adequate biomass and catabolic capacity may be absent even when electron donors and acceptors are plentiful, and in such cases bioaugmentation or other engineered strategies should be considered for subsurface remediation.Ph.D.Applied SciencesBiogeochemistryBiological SciencesEarth SciencesEnvironmental engineeringMicrobiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/132004/2/9938538.pd

Effect of epigallocatechin gallate on DNA damage induced by etoposide in human leukemic K562 cells.

Public interest in green tea has grown recently due to the potential health benefits from its consumption. Epigallocatechin gallate (EGCG), a principal polyphenolic component of green tea, is considered key to these healthful qualities. In recent years, many studies have shown strong chemopreventive and possibly cancer chemotherapeutic effects of EGCG against cancers of the blood, skin, lung, breast, colon, liver, stomach and prostate. In vivo and in vitro experiments have shown that high concentrations of EGCG are cytotoxic and trigger genotoxic events in human cells. Although this catechin affects a number of cellular systems, the genotoxic effects are believed to be mediated by their actions on topoisomerase II.Of the many commercially available anticancer drug etoposide was selected for testing, which, although discovered more than forty years ago, is still one of the most common chemotherapeutic drugs for the treatment of a wide spectrum of cancers.The present investigation was carried out to examine the effects of EGCG on the cytogenetic change and DNA damage induced by etoposide in human K562 cells.Incubation of cells K562 with epigallocatechin gallate (concentration range of 0-100 µM) caused an increase in DNA damage depending on the dosage used. The EGCG, especially in concentration 50 M increased levels of DNA strand breaks. Percentage of cells with the single apoptosis was also dependent on the concentration and incubation time of cells K562 with etoposide (concentration range of 0–1,5µM) and/or EGCG. Exposure of K562 cells by 24 and 48 h of action of EGCG and then apply the 1h etoposide dose of 0,5 M increased the percentage of apoptotic cells observed immediately after removal of the compounds. Number of micronuclei formed, reflecting damage to genetic material of chromosomes was dependent on dose and duration of EGCG. The obtained results demonstrate that EGCG stimulates DNA cleavage and induction of apoptosis in K562 cells.Galusan epigallokatechiny (EGCG) jest głównym związkiem polifenolowym wchodzącym w skład zielonej herbaty. Obecność EGCG stanowi czynnik kluczowy dla zdrowotnych właściwości tej odmiany herbaty oraz determinuje jej zdolności chemoprewencyjne oraz chemoterapeutyczne wykorzystywane w leczeniu białaczek, nowotworów skóry, płuc, piersi, prostaty, okrężnicy i wątroby. W badaniach in virto oraz in vivo wykazano, że wysokie stężenia EGCG są cytotoksyczne oraz indukują wiele procesów genotoksycznych w ludzkich komórkach. Pomimo iż katechiny oddziałują na wiele struktur komórkowych, uważa się że genotoksyczny efekt jest związany z ich oddziaływaniem na topoizomerazę II. Z pośród wielu dostępnych leków przeciwnowotworowych do badań wybrano etopozyd, który mimo iż został odkryty ponad czterdzieści lat temu nadal jest jednym z najczęściej stosowanych leków w terapii szerokiego spektrum nowotworów.Celem niniejszej pracy było określenie, czy EGCG wywiera wpływ na zmiany cytogenetyczne oraz uszkodzenia DNA indukowane etopozydem w komórkach linii K562.Przeprowadzone badania wykazują, że inkubacja komórek K652 z galusanem epigalloktechiny w zakresie stężeń 1-100 µM powoduje wzrost uszkodzeń DNA w stopniu zależnym od zastosowanej dawki. Galusan epigallokatechiny, szczególnie w wysokim stężeniu 50 µM zwiększa poziom uszkodzeń nici kwasu deoksyrybonukleinowego. Odsetek komórek wchodzących na drogę apoptozy również zależy od zastosowanej dawki EGCG oraz czasu inkubacji komórek z EGCG i/lub etopozydem. Ekspozycja komórek K562 przez 24 oraz 48 godzin na działanie EGCG w stężeniach 1-100 µM i 1 godzinne działanie 0,5 µM etopozydu zwiększa odsetek obserwowanych komórek apoptotycznych. Liczba powstałych mikrojąder, odzwierciedlających uszkodzenia materiału genetycznego i chromosomów jest także zależna od zastosowanej dawki i czasu inkubacji komórek K562 z EGCG. Uzyskane wyniki potwierdzają, że EGCG wpływa na uszkodzenia materiału genetycznego i indukcję procesu apoptozy w komórkach linii K562

Can epigallocatechin gallate be an effective polyphenol in combination therapy with etoposide for the treatment of chronic myelogenous leukemia?

Publikacja recenzowana / Peer-reviewed publicationWprowadzenie: Składnik zielonej herbaty – galusan epigallokatechiny (EGCG) – znany jest ze swoich właściwości chemoprewencyjnych i chemoterapeutycznych. Wykazuje silne właściwości antyoksydacyjne i przeciwzapalne, a w stosunku do komórek nowotworowych – działanie antyproliferacyjne lub proapoptotyczne. Etopozyd jest jednym z najczęściej stosowanych leków przeciwnowotworowych, wywołującym jednak wiele skutków ubocznych. Materiały i metody: W eksperymentach in vitro badano potencjalną rolę EGCG w terapii skojarzonej z etopozydem w leczeniu przewlekłej białaczki szpikowej. Komórki ustalonej linii białaczkowej K562 poddano działaniu etopozydu i/lub EGCG w celu określenia wpływu EGCG na przeżywalność komórek, poziom uszkodzeń DNA oraz częstość procesu apoptozy. Poziom uszkodzeń DNA mierzono przy pomocy elektroforezy pojedynczych komórek w żelu agarozowym (test kometowy), natomiast apoptozę oceniano pod mikroskopem fluorescencyjnym z użyciem barwnika Hoechst 33342. Wyniki: Uzyskane wyniki badań wskazują, że EGCG w stężeniu 50 i 100 μM uwrażliwia komórki białaczkowe na cytotoksyczne działanie etopozydu, zwiększając poziom uszkodzeń DNA i częstość apoptozy. Wnioski: Dane wskazują, że galusan epigallokatechiny może się okazać skutecznym polifenolem w terapii skojarzonej z etopozydem w leczeniu przewlekłej białaczki szpikowej.Introduction: Green tea ingredient – epigallocatechin gallate (EGCG) – is known for its chemopreventive and chemotherapeutic properties. It has strong antioxidant and anti-inflammatory properties, and antiproliferative or proapoptotic activity against cancer cells. Etoposide is one of the most commonly used anti-cancer drugs causing many side effects. Materials and methods: This study investigated the role of EGCG in combination therapy with etoposide in the treatment of chronic myeloid leukemia. K562 cells were treated with EGCG and / or etoposide to determine the effect of this polyphenol on cell survival, DNA damage or apoptosis. DNA damages were measured with single cell gel electrophoresis (comet assay) and the apoptosis were analyzed in fluorescence microscope with Hoechst 33342 staining. Results: Preliminary results suggest that EGCG at 50 and 100 μM sensitizes leukemic cells to the cytotoxic effect of etoposide, increases DNA damage that promotes removal cell and directs them to apoptosis. Conclusions: The data show that epigallocatechin gallate may prove to be an eff ective polyphenol in combination therapy with etoposide in the treatment of chronic myeloid leukemia. However, further research is needed to explain the EGCG interaction with chemotherapeutics

The most common fractures in children practicing skiing for pleasure

Wstęp. Narciarstwo zjazdowe jest sportem cieszącym się coraz większą popularnością zarówno u osób młodych, dorosłych, jak i osób w podeszłym wieku. Każdej dyscyplinie sportowej towarzyszy ryzyko wystąpienia kontuzji lub bardziej złożonego urazu. W narciarstwie ważne jest zapewnienie bezpieczeństwa narciarzy poprzez sprawny sprzęt narciarski, odpowiedni ubiór, prawidłowo przygotowana trasa zjazdowa oraz przygotowanie funkcjonalne i motoryczne sportowca. Celem badań było stwierdzenie czy płeć oraz wiek wpływają na rodzaj złamania, sposób leczenia, czas pobytu w szpitalu, okres unieruchomienia kończyny, dodatkowo badano zależność między metodą leczenia kończyny a rodzajem złamania, czasem unieruchomienia oraz okresem hospitalizacji. Materiał i metody. Do badania zakwalifikowano 45 dzieci (41 chłopców, 4 dziewczyny) w wieku od 5 do 16 lat. Zebrane dane pochodziły z historii pacjentów leczonych w Klinicznym Szpitalu Wojewódzkim nr 2 im. Świętej Jadwigi Królowej w Rzeszowie. Wyniki. Płeć i wiek nie mają wpływu na rodzaj złamania, sposób leczenia, czas pobytu w szpitalu oraz okres unieruchomienia kończyny. Z badań własnych wynika, że rodzaj złamania ma istotny statystycznie wpływ na sposób leczenia, czas hospitalizacji oraz okres unieruchomienia kończyny (p<0.05). Dodatkowo wykazano, że zastosowana metoda leczenia ma istotny wpływ na długość hospitalizacji pacjenta. Wnioski. Wykazano, że rodzaj złamania miał wpływ na okres hospitalizacji. Mali pacjenci ze złamaniami wieloodłamowymi oraz spiralnymi kości podudzia wymagają dłuższego czasu obserwacji w warunkach szpitalnych. Stwierdzono, że czas unieruchomienia kończyny był konsekwencją rodzaju doznanego złamania oraz sposobu zastosowanego leczenia.Background. Alpine skiing is becoming more and more popular sport among young people, adults and the elderly. Each sport discipline is accompanied by the risk of injury or more complex trauma. During skiing, it is important to ensure the safety of skiers through efficient skiing equipment, appropriate clothing, properly prepared slope as well as functional and motor preparation of the athlete. The aim of the study was to determine whether sex and age affect the type of fracture, treatment management, length of hospitalization, limb immobilization period. Additionally, the relationship between the limb healing method and the type of fracture, time of immobilization and period of hospitalization were studied. Material and methods: 45 children (41 boys, 4 girls) aged from 5 to 16 years were enrolled in the study. The collected data were acquired from medical history files of the patients treated in the Saint Hedwig Provincial Clinical Hospital No 2 in Rzeszów. Results: Sex and age do not affect the type of fracture, treatment method, duration of hospitalization and limb immobilization period. Our research shows that the type of fracture has a statistically significant effect on the treatment, the time of hospitalization and limb immobilization period (p <0.05). In addition, it has been shown that the treatment method used has a significant impact on the length of the patient’s hospitalization. Conclusions: It was shown that the type of fracture had an effect on the period of hospitalization. Small patients with multiple and spiral fractures of the lower leg required longer observation in hospital setting. The limb immobilization time was a consequence of the type of fracture experienced and the method of treatment used