642 research outputs found

    P(P bar)P elastic scattering and cosmic ray data

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    It is shown that the total cross section for pp elastic scattering at cosmic ray energies, as well as the total cross section, the slope parameter b(s,t) and the differential cross section for small momentum transfer at ISR and collider energies for p(p)p elastic scattering can be simultaneously fitted by using a simple Regge pole model. The results of this theory is discussed in detail

    Targeting cell cycle regulators in hematologic malignancies

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    © 2015 Aleem and Arceci. Hematologic malignancies represent the fourth most frequently diagnosed cancer in economically developed countries. In hematologic malignancies normal hematopoiesis is interrupted by uncontrolled growth of a genetically altered stem or progenitor cell (HSPC) that maintains its ability of self-renewal. Cyclin-dependent kinases (CDKs) not only regulate the mammalian cell cycle, but also influence other vital cellular processes, such as stem cell renewal, differentiation, transcription, epigenetic regulation, apoptosis, and DNA repair. Chromosomal translocations, amplification, overexpression and altered CDK activities have been described in different types of human cancer, which have made them attractive targets for pharmacological inhibition. Mouse models deficient for one or more CDKs have significantly contributed to our current understanding of the physiological functions of CDKs, as well as their roles in human cancer. The present review focuses on selected cell cycle kinases with recent emerging key functions in hematopoiesis and in hematopoietic malignancies, such as CDK6 and its role in MLL-rearranged leukemia and acute lymphocytic leukemia, CDK1 and its regulator WEE-1 in acute myeloid leukemia (AML), and cyclin C/CDK8/CDK19 complexes in T-cell acute lymphocytic leukemia. The knowledge gained from gene knockout experiments in mice of these kinases is also summarized. An overview of compounds targeting these kinases, which are currently in clinical development in various solid tumors and hematopoietic malignances, is presented. These include the CDK4/CDK6 inhibitors (palbociclib, LEE011, LY2835219), pan-CDK inhibitors that target CDK1 (dinaciclib, flavopiridol, AT7519, TG02, P276-00, terampeprocol and RGB 286638) as well as the WEE-1 kinase inhibitor, MK-1775. The advantage of combination therapy of cell cycle inhibitors with conventional chemotherapeutic agents used in the treatment of AML, such as cytarabine, is discussed

    Identifying lifestyle factors associated to co-morbidity of obesity and psychiatric disorders, a pilot study

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    Obesity and psychiatric disorders are linked through a bidirectional association. Obesity rates have tripled globally in the past decades, and it is predicted that by 2025, one billion people will be affected by obesity, often with a co-morbidity such as depression. While this co-morbidity seems to be a global health issue, lifestyle factors associated to it differ between countries and are often attributed to more than one factor. Prior obesity studies were performed in Western populations; this is the first study that investigates lifestyle factors relating to obesity and mental health of the diverse population in Qatar, a country that has witnessed tremendous lifestyle change in a short time. In this pilot study, we surveyed 379 respondents to assess and compare the lifestyles of Qatar residents to the global population. However due to the high proportion of responses from the United Kingdom (UK) residents, we have made comparisons between Qatar residents and UK residents. We used chi-square analysis, spearman rank correlation and logistic regression to compare the lifestyle factors of individuals suffering from both increased BMI and mental health conditions. The types of food consumed, stress, exercise frequency and duration, alcohol and tobacco consumption, and sleep duration, were explored and results argue that different lifestyle factors can contribute to the same health condition, suggesting different mechanisms involved. We found that both groups reported similar sleep durations (p = 0.800), but that perception of sleep (p = 0.011), consumption of alcohol (p = 0.001), consumption of takeaway food (p = 0.007), and physical activity significantly varied between the groups (p = 0.0001). The study examined the predictors of comorbidity in Qatar as well as UK populations using multivariate logistic regression analysis. The result of the study showed no statistical association between comorbidity and the predictors drinking habit, smoking, physical activity, vegetable consumption, eat outs, and sleep perception for the Qatar population, and for the combined population. This study, however showed a significant association (p = 0.033) between sleep perception and comorbidity for the UK population. We conclude that further analysis is needed to understand the relationship between specific lifestyle factors and multimorbidity in each country

    Total Cross Sections at current/Future Colliders, conventional models and QCD

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    Rise in total cross sections for elastic scattering generated immense interest both for experimental measurements and theoretical investigations. How will total cross section behave at LHC and Cosmic Ray energies is therefore in the limelight of our future measurements. Theoretical studies become even more interesting when we take into consideration the ratio of real and imaginary parts of the scattering amplitudes. We will briefly undertake the current results and future prospects in the light of conventional as well as QCD-based phenomenology

    Expression of recombinant Streptokinase from local Egyptian Streptococcus sp. SalMarEg

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    Streptokinase (SK) is a therapeutically important thrombolytic agent. Cardiovascular disease is the first cause of adult death worldwide. In Egypt about 13% of the population die every year due to ischemic heart disease. In spite of this fact, there is no local production of cardiovascular therapeutics. We reported for the first time the expression of a recombinant SK from a local Streptococcus strain. When produced on industrial scale this r-SK may substantially contribute to reducing the costs of thrombolytic therapy in developing countries. In this study, a highly purified r-SK from Streptococcus sp. isolated from Egyptian pharyngitis patients was obtained. The isolated strain was partially identified using 16S rDNA sequencing and named Streptococcus sp. SalMarEg. It was found to be phylogenetically related to Streptococcus pyogenes. Analysis of the obtained sequence showed high similarity with other SK genes. The protein expression in a prokaryotic system obtained a 47-kDa SK protein that could be purified using a single-step his-tagged affinity purification chromatography, with nearly 80% recovery. The clot lytic activities of both recombinant and commercial SK were similar, thus giving the basis to scale up this SK product in order to evaluate the possibilities of its commercialization in local and/or regional markets.Key words: Streptokinase, Streptococcus SalMarEg, thrombolytic agent, heterologous expression

    Picropodophyllin causes mitotic arrest and catastrophe by depolymerizing microtubules via Insulin-like growth factor-1 receptor-independent mechanism

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    Picropodophyllin (PPP) is an anticancer drug undergoing clinical development in NSCLC. PPP has been shown to suppress IGF-1R signaling and to induce a G2/M cell cycle phase arrest but the exact mechanisms remain to be elucidated. The present study identified an IGF-1-independent mechanism of PPP leading to pro-metaphase arrest. The mitotic block was induced in human cancer cell lines and in an A549 xenograft mouse but did not occur in normal hepatocytes/mouse tissues. Cell cycle arrest by PPP occurred in vitro and in vivo accompanied by prominent CDK1 activation, and was IGF-1R-independent since it occurred also in IGF-1R-depleted and null cells. The tumor cells were not arrested in G2/M but in mitosis. Centrosome separation was prevented during mitotic entry, resulting in a monopolar mitotic spindle with subsequent prometaphase-arrest, independent of Plk1/Aurora A or Eg5, and leading to cell features of mitotic catastrophe. PPP also increased soluble tubulin and decreased spindle-associated tubulin within minutes, indicating that it interfered with microtubule dynamics. These results provide a novel IGF-1R-independent mechanism of antitumor effects of PPP

    Nuclear insulin-like growth factor 1 receptor phosphorylates proliferating cell nuclear antigen and rescues stalled replication forks after DNA damage

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    We have previously shown that the insulin like growth factor 1 receptor (IGF1R) translocates to the cell nucleus, where it binds to enhancer like regions and increases gene transcription. Further studies have demonstrated that nuclear IGF1R (nIGF1R) physically and functionally interacts with some nuclear proteins, i.e. the lymphoid enhancer binding factor 1 (Lef1), histone H3, and Brahma related gene 1 proteins. In the present study, we identified the proliferating cell nuclear antigen (PCNA) as a nIGF1R binding partner. PCNA is a pivotal component of the replication fork machinery and a main regulator of the DNA damage tolerance (DDT) pathway. We found that IGF1R interacts with and phosphorylates PCNA in human embryonic stem cells and other cell lines. In vitro MS analysis of PCNA coincubated with the IGF1R kinase indicated tyrosine residues 60, 133, and 250 in PCNA as IGF1R targets, and PCNA phosphorylation was followed by mono and poly ubiquitination. Coimmunoprecipitation experiments suggested that these ubiquitination events may be mediated by DDT dependent E2/E3 ligases (e.g. RAD18 and SHPRH/HLTF). Absence of IGF1R or mutation of Tyr60, Tyr133, or Tyr250 in PCNA abrogated its ubiquitination. Unlike in cells expressing IGF1R, externally induced DNA damage in IGF1R negative cells caused G1 cell cycle arrest and S phase fork stalling. Taken together, our results suggest a role of IGF1R in DDT
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