567 research outputs found
Linalool, a plant-derived monoterpene alcohol, reverses doxorubicin resistance in human breast adenocarcinoma cells
Essential oils from various aromatic plants have been reported to exert chemopreventive and/or antitumor effects. In addition, a number of studies have shown the ability of chemopreventive phytochemicals to increase the sensitivity of cancer cells to conventional anticancer drugs. The success of chemotherapeutic agents is often hindered by the development of drug resistance, with multidrug resistant (MDR) phenotypes reported in a number of tumors, generally involving reduced intracellular drug accumulation due to increased drug efflux by membrane transporters. In the present study, the effects of linalool (LIN), a monoterpene alcohol found in the essential oils from many aromatic plants, on the growth of two human breast adenocarcinoma cell lines, MCF7 WT and multidrug resistant MCF7 AdrR, were investigated, both as a single agent and in combination with doxorubicin (DOX). The results reported here show that LIN only moderately inhibits cell proliferation; interestingly, however, subtoxic concentrations of LIN potentiate DOX-induced cytotoxicity and pro-apoptotic effects in both cell lines. A significant synergism can be observed in MCF7 AdrR cells, which may be due, at least in part, to the ability of LIN to increase DOX accumulation and to induce a decrease in Bcl-xL levels. In summary, the results of the present study suggest that LIN may improve the therapeutic index of anthracyclines in the management of breast cancer, especially in MDR tumors
Control of the urban pigeon Columba livia population and the preservation of common swift Apus apus and bats Chiroptera during the restoration of the Ghirlandina tower in the city of Modena (Italy)
Ferri, M., Ferraresi, M., Gelati, A., Zannetti, G., Domenichini, A., Ravizza, L., Cadignani, R
Role of the p53/p21 system in the response of human colon carcinoma cells to Doxorubicin
BACKGROUND: Colon adenocarcinomas are refractory to a number of widely used anticancer agents. Multifactorial mechanisms have been implicated in this intrinsically resistant phenotype, including deregulation of cell death pathways. In this regard, the p53 protein has a well established role in the control of tumor cell response to DNA damaging agents; however, the relationship between p53-driven genes and drug sensitivity remains controversial. The present study investigates the role of the p53/p21 system in the response of human colon carcinoma cells to treatment with the cytotoxic agent doxorubicin (DOX) and the possibility to modify the therapeutic index of DOX by modulation of p53 and/or p21 protein levels. METHODS: The relationship between p53 and p21 protein levels and the cytotoxic effect of DOX was investigated, by MTT assay and western blot analysis, in HCT116 (p53-positive) and HT29 (p53-negative) colon cancer cells. We then assessed the effects of DOX in two isogenic cell lines derived from HCT116 by abrogating the expression and/or function of p53 and p21 (HCT116-E6 and HCT116 p21-/-, respectively). Finally, we evaluated the effect of pre-treatment with the piperidine nitroxide Tempol (TPL), an agent that was reported to induce p21 expression irrespective of p53 status, on the cytotoxicity of DOX in the four cell lines. Comparisons of IC50 values and apoptotic cell percentages were performed by ANOVA and Bonferroni's test for independent samples. C.I. calculations were performed by the combination Index method. RESULTS: Our results indicate that, in the colon carcinoma cell lines tested, sensitivity to DOX is associated with p21 upregulation upon drug exposure, and DOX cytotoxicity is potentiated by pre-treatment with TPL, but only in those cell lines in which p21 can be upregulated. CONCLUSIONS: p21 induction may significantly contribute to the response of colon adenocarcinomas cells to DOX treatment; and small molecules that can exploit p53-independent pathways for p21 induction, such as TPL, may find a place in chemotherapeutic protocols for the clinical management of colorectal cancer, where p53 function is often lost, due to genetic or epigenetic defects or to post-transcriptional inactivating mechanisms
Psychological models in sport psychology:A preliminary investigation
Applied psychology is characterised by a variety of theoretical models, informing distinct approaches to classification, explanation, and intervention in service-delivery. Such theoretical or psychological models include behavioural, biological, cognitive, humanistic, psychodynamic, and social paradigms, with exposure to these models and attitude formation occurring within the structured university-based stage of sport psychology development. It is, therefore, important for the sport psychological domain to investigate developing attitudes, given these models inform subsequent professional practice and decision making. Accordingly, the present study explored the attitudes of Stage-1 sport psychology students through a modified form of the Maudsley Attitude Questionnaire (34 males, Mage = 24.71 years, SD = 7.23 and 42 females, Mage = 24.76 years, SD = 6.20). The questionnaire was designed to assess attitudes across eight psychological models (e.g., biological, cognitive) and four sport psychology issues (pre-performance anxiety, a lack of confidence, depression, and eating disorders). Analyses of variance demonstrated significant main, model, and interaction effects. No one psychological model was endorsed by all respondents, with model endorsement varying signiļ¬cantly as a function of the issue presented. Principal Axis Factoring revealed a large contribution attributable to cognitive-behavioural and āeclecticā (mixed elements of social constructionism, biological, and psychodynamic) models. In contrast, the spiritual model represented low levels of participant endorsement and application. Investigation of Stage-1 students can promote an evidence-based understanding on currently developing attitudes and inform the development of sport psychology education, supervision of training routes, and subsequent professional delivery
An extraterrestrial trigger for the Early Cretaceous massive volcanism? Evidence from the paleo-Tethys Ocean
The Early Cretaceous Greater Ontong Java Event in the Pacific Ocean may have covered ca. 1% of the Earth's surface with volcanism. It has puzzled scientists trying to explain its origin by several mechanisms possible on Earth, leading others to propose an extraterrestrial trigger to explain this event. A large oceanic extraterrestrial impact causing such voluminous volcanism may have traces of its distal ejecta in sedimentary rocks around the basin, including the paleo-Tethys Ocean which was then contiguous with the Pacific Ocean. The contemporaneous marine sequence at central Italy, containing the sedimentary expression of a global oceanic anoxic event (OAE1a), may have recorded such ocurrence as indicated by two stratigraphic intervals with 187Os/188Os indicative of meteoritic influence. Here we show, for the first time, that platinum group element abundances and inter-element ratios in this paleo-Tethyan marine sequence provide no evidence for an extraterrestrial trigger for the Early Cretaceous massive volcanism
The trade-off between taxi time and fuel consumption in airport ground movement
Environmental impact is a very important agenda item in many sectors nowadays, which the air transportation sector is also trying to reduce
as much as possible. One area which has remained relatively unexplored in this context is the ground movement problem for aircraft on the airportās surface.
Aircraft have to be routed from a gate to a runway and vice versa and it is
still unknown whether fuel burn and environmental impact reductions will best result from purely minimising the taxi times or whether it is also important to avoid multiple acceleration phases. This paper presents a newly developed multi-objective approach for analysing the trade-off between taxi time and fuel consumption during taxiing. The approach consists of a combination of a graph-based routing algorithm and a population adaptive immune algorithm to discover different speed profiles of aircraft. Analysis with data from a European hub airport has highlighted the impressive performance of the new approach. Furthermore, it is shown that the trade-off between taxi time and fuel consumption is very sensitive to the fuel-related objective function which is used
Detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography (FDG-PET/CT)
The purpose of this study was to analyze the detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT).
Data for a total of 492 patients who had undergone both PET/CT and colonoscopy were analyzed. After the findings of PET/CT and colonoscopy were determined independently, the results were compared in each of the six colonic sites examined in all patients. The efficacy of PET/CT was determined using colonoscopic examination as the gold standard.
In all, 270 colorectal lesions 5 mm or more in size, including 70 pathologically confirmed malignant lesions, were found in 172 patients by colonoscopy. The sensitivity and specificity of PET/CT for detecting any of the colorectal lesions were 36 and 98%, respectively. For detecting lesions 11 mm or larger, the sensitivity was increased to 85%, with the specificity remaining consistent (97%). Moreover, the sensitivity for tumors 21 mm or larger was 96% (48/50). Tumors with malignant or high-grade pathology were likely to be positive with PET/CT. A size of 10 mm or smaller [odds ratio (OR) 44.14, 95% confidence interval (95% CI) 11.44-221.67] and flat morphology (OR 7.78, 95% CI 1.79-36.25) were significant factors that were associated with false-negative cases on PET/CT.
The sensitivity of PET/CT for detecting colorectal lesions is acceptable, showing size- and pathology-dependence, suggesting, for the most part, that clinically relevant lesions are detectable with PET/CT. However, when considering PET/CT for screening purposes caution must be exercised because there are cases of false-negative results
A fossil winonaite-like meteorite in Ordovician limestone: A piece of the impactor that broke up the L-chondrite parent body?
AbstractAbout a quarter of all meteorites falling on Earth today originate from the breakup of the L-chondrite parent body ā¼470Ā Ma ago, the largest documented breakup in the asteroid belt in the past ā¼3Ā Ga. A window into the flux of meteorites to Earth shortly after this event comes from the recovery of about 100 fossil L chondrites (1ā21 cm in diameter) in a quarry of mid-Ordovician limestone in southern Sweden. Here we report on the first non-L-chondritic meteorite from the quarry, an 8 cm large winonaite-related meteorite of a type not known among present-day meteorite falls and finds. The noble gas data for relict spinels recovered from the meteorite show that it may be a remnant of the body that hit and broke up the L-chondrite parent body, creating one of the major asteroid families in the asteroid belt. After two decades of systematic recovery of fossil meteorites and relict extraterrestrial spinel grains from marine limestone, it appears that the meteorite flux to Earth in the mid-Ordovician was very different from that of today
Task-Specific Effects of tDCS-Induced Cortical Excitability Changes on Cognitive and Motor Sequence Set Shifting Performance
In this study, we tested the effects of transcranial Direct Current Stimulation (tDCS) on two set shifting tasks. Set shifting ability is defined as the capacity to switch between mental sets or actions and requires the activation of a distributed neural network. Thirty healthy subjects (fifteen per site) received anodal, cathodal and sham stimulation of the dorsolateral prefrontal cortex (DLPFC) or the primary motor cortex (M1). We measured set shifting in both cognitive and motor tasks. The results show that both anodal and cathodal single session tDCS can modulate cognitive and motor tasks. However, an interaction was found between task and type of stimulation as anodal tDCS of DLPFC and M1 was found to increase performance in the cognitive task, while cathodal tDCS of DLPFC and M1 had the opposite effect on the motor task. Additionally, tDCS effects seem to be most evident on the speed of changing sets, rather than on reducing the number of errors or increasing the efficacy of irrelevant set filtering
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