364 research outputs found

    The mouse alpha-globin cluster: A paradigm for studying genome regulation and organization

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    The mammalian globin gene clusters provide a paradigm for studying the relationship between genome structure and function. As blood stem cells undergo lineage specification and differentiation to form red blood cells, the chromatin structure and expression of the α-globin cluster change. The gradual activation of the α-globin genes in well-defined cell populations has enabled investigation of the structural and functional roles of its enhancers, promoters and boundary elements. Recent studies of gene regulatory processes involving these elements at the mouse α-globin cluster have brought new insights into the general principles underlying the three-dimensional structure of the genome and its relationship to gene expression throughout time

    UVA-induced carbon-centered radicals in lightly pigmented cells detected using ESR spectroscopy

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    Ultraviolet-A and melanin are implicated in melanoma, but whether melanin in vivo screens or acts as a UVA photosensitiser is debated. Here, we investigate the effect of UVA-irradiation on non-pigmented, lightly and darkly pigmented melanocytes and melanoma cells using electron spin resonance (ESR) spectroscopy. Using the spin trap 5,5 Dimethyl-1-pyrroline N-oxide (DMPO), carbon adducts were detected in all cells. However, higher levels of carbon adducts were detected in lightly pigmented cells than in non-pigmented or darkly pigmented cells. Nevertheless, when melanin levels were artificially increased in lightly pigmented cells by incubation with L-Tyrosine, the levels of carbon adducts decreased significantly. Carbon adducts were also detected in UVA-irradiated melanin-free cell nuclei, DNA-melanin systems, and the nucleoside 2’-deoxyguanosine combined with melanin, whereas they were only weakly detected in irradiated synthetic melanin and not at all in irradiated 2’-deoxyguanosine. The similarity of these carbon adducts suggests they may be derived from nucleic acid– guanine – radicals. These observations suggest that melanin is not consistently a UVA screen against free-radical formation in pigmented cells, but may also act as a photosensitizer for the formation of nucleic acid radicals in addition to superoxide. The findings are important for our understanding of the mechanism of damage caused by the UVA component of sunlight in non-melanoma and melanoma cells, and hence the causes of skin cancer

    The role of plasma membrane STIM1 and Ca2+entry in platelet aggregation. STIM1 binds to novel proteins in human platelets

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    Ca(2+) elevation is essential to platelet activation. STIM1 senses Ca(2+) in the endoplasmic reticulum and activates Orai channels allowing store-operated Ca(2+) entry (SOCE). STIM1 has also been reported to be present in the plasma membrane (PM) with its N-terminal region exposed to the outside medium but its role is not fully understood. We have examined the effects of the antibody GOK/STIM1, which recognises the N-terminal region of STIM1, on SOCE, agonist-stimulated Ca(2+) entry, surface exposure, in vitro thrombus formation and aggregation in human platelets. We also determined novel binding partners of STIM1 using proteomics. The dialysed GOK/STIM1 antibody failed to reduced thapsigargin- and agonist-mediated Ca(2+) entry in Fura2-labelled cells. Using flow cytometry we detect a portion of STIM1 to be surface-exposed. The dialysed GOK/STIM1 antibody reduced thrombus formation by whole blood on collagen-coated capillaries under flow and platelet aggregation induced by collagen. In immunoprecipitation experiments followed by proteomic analysis, STIM1 was found to extract a number of proteins including myosin, DOCK10, thrombospondin-1 and actin. These studies suggest that PM STIM1 may facilitate platelet activation by collagen through novel interactions at the plasma membrane while the essential Ca(2+)-sensing role of STIM1 is served by the protein in the ER

    Retroperitoneal lymph node dissection for residual masses after chemotherapy in nonseminomatous germ cell testicular tumor

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    <p>Abstract</p> <p>Background</p> <p>Retroperitoneal lymph node dissection has been advocated for the management of post-chemotherapy (PC-RPLND) residual masses of non-seminomatous germ cell tumors of the testis (NSGCT). There remains some debate as to the clinical benefit and associated morbidity. Our objective was to report our experience with PC-RPLND in NSGCT.</p> <p>Methods</p> <p>We have reviewed the clinical, pathologic and surgical parameters associated with PC-RPLND in a single institution. Between 1994 and 2008, three surgeons operated 73 patients with residual masses after cisplatin-based chemotherapy for a metastatic testicular cancer. Patients needed to have normal postchemotherapy serum tumor markers, no prior surgical attempts to resect retroperitoneal masses and resectable retroperitoneal tumor mass at surgery to be included in this analysis</p> <p>Results</p> <p>Mean age was 30.4 years old. Fifty-three percent had mixed germ cell tumors. The mean size of retroperitoneal metastasis was 6.3 and 4.0 cm, before and post-chemotherapy, respectively. In 56% of patients, the surgeon was able to perform a nerve sparing procedure. The overall complication rate was 27.4% and no patient died due to surgical complications. The pathologic review showed presence of fibrosis/necrosis, teratoma and viable tumor (non-teratoma) in 27 (37.0%), 30 (41.1%) and 16 (21.9%) patients, respectively. The subgroups presenting fibrosis and large tumors were more likely to have a surgical complication and had less nerve sparing procedures.</p> <p>Conclusion</p> <p>PC-RPLND is a relatively safe procedure. The presence of fibrosis and large residual masses are associated with surgical complications and non-nerve-sparing procedure.</p

    Towards cyber-resilient telecontrol commands using software-defined networking

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    Cybersecurity enhancement of power systems has become one of the main objectives of utility managers and regulatory agencies because of the increasing number of cyberattacks against critical infrastructures. In this paper, we investigate the application of software-defined networking for improving the cyber-resilience of power systems in the presence of cyberattacks using false telecontrol commands. It is first demonstrated that cyberattackers can use false telecontrol commands to separate a power plant from a power grid or trip a major transmission line. Next, it is shown that software-defined networking can significantly enhance the cyber-resilience of power systems in the presence of cyberattacks using false telecontrol commands compared to legacy communication networks. This is because the source, destination and protocol of telecontrol commands can be examined and verified in software-defined networking before communication packet forwarding actions take place. Moreover, primary and back-up routes of telecontrol commands can be pre-engineered in software-defined networking to counteract potential cyberattacks

    Hybrid in vitro diffusion cell for simultaneous evaluation of hair and skin decontamination: temporal distribution of chemical contaminants

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    Most casualty or personnel decontamination studies have focused on removing contaminants from the skin. However, scalp hair and underlying skin are the most likely areas of contamination following airborne exposure to chemicals. The aim of this study was to investigate the interactions of contaminants with scalp hair and underlying skin using a hybrid in vitro diffusion cell model. The in vitro hybrid test system comprised “curtains” of human hair mounted onto sections of excised porcine skin within a modified diffusion cell. The results demonstrated that hair substantially reduced underlying scalp skin contamination and that hair may provide a limited decontamination effect by removing contaminants from the skin surface. This hybrid test system may have application in the development of improved chemical incident response processes through the evaluation of various hair and skin decontamination strategies.Peer reviewedFinal Published versio

    Concomitant CIS on TURBT does not impact oncological outcomes in patients treated with neoadjuvant or induction chemotherapy followed by radical cystectomy

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    © Springer-Verlag GmbH Germany, part of Springer Nature 2018Background: Cisplatin-based neoadjuvant chemotherapy (NAC) for muscle invasive bladder cancer improves all-cause and cancer specific survival. We aimed to evaluate whether the detection of carcinoma in situ (CIS) at the time of initial transurethral resection of bladder tumor (TURBT) has an oncological impact on the response to NAC prior to radical cystectomy. Patients and methods: Patients were identified retrospectively from 19 centers who received at least three cycles of NAC or induction chemotherapy for cT2-T4aN0-3M0 urothelial carcinoma of the bladder followed by radical cystectomy between 2000 and 2013. The primary and secondary outcomes were pathological response and overall survival, respectively. Multivariable analysis was performed to determine the independent predictive value of CIS on these outcomes. Results: Of 1213 patients included in the analysis, 21.8% had concomitant CIS. Baseline clinical and pathologic characteristics of the ‘CIS’ versus ‘no-CIS’ groups were similar. The pathological response did not differ between the two arms when response was defined as pT0N0 (17.9% with CIS vs 21.9% without CIS; p = 0.16) which may indicate that patients with CIS may be less sensitive to NAC or ≀ pT1N0 (42.8% with CIS vs 37.8% without CIS; p = 0.15). On Cox regression model for overall survival for the cN0 cohort, the presence of CIS was not associated with survival (HR 0.86 (95% CI 0.63–1.18; p = 0.35). The presence of LVI (HR 1.41, 95% CI 1.01–1.96; p = 0.04), hydronephrosis (HR 1.63, 95% CI 1.23–2.16; p = 0.001) and use of chemotherapy other than ddMVAC (HR 0.57, 95% CI 0.34–0.94; p = 0.03) were associated with shorter overall survival. For the whole cohort, the presence of CIS was also not associated with survival (HR 1.05 (95% CI 0.82–1.35; p = 0.70). Conclusion: In this multicenter, real-world cohort, CIS status at TURBT did not affect pathologic response to neoadjuvant or induction chemotherapy. This study is limited by its retrospective nature as well as variability in chemotherapy regimens and surveillance regimens.Peer reviewedFinal Accepted Versio

    Impacto do programa bolsa famĂ­lia sobre a frequĂȘncia escolar: o caso da agricultura familiar no Nordeste do Brasil.

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    O objetivo deste trabalho Ă© avaliar o impacto do programa de transferĂȘncia de renda condicionada Bolsa FamĂ­lia sobre a frequĂȘncia escolar de crianças e adolescentes de cinco a 14 anos na agricultura familiar dos estados de Pernambuco, CearĂĄ, Sergipe e ParaĂ­ba. Nessa investigação, o trabalho faz uso de dados primĂĄrios (pesquisa de campo) e dados secundĂĄrios (PNAD, 2005) para obter estimativas de propensity score. Os resultados indicam que, de forma geral, o programa eleva a frequĂȘncia escolar das referidas crianças no intervalo de 5,4 a 5,9 pontos percentuais. Contudo, hĂĄ importantes diferenças quando se considera meninas e meninos separadamente, sendo o programa eficaz no primeiro caso e ineficaz no segundo. Ou seja, apesar da avaliação positiva para as meninas, nĂŁo parece haver efeito do programa sobre a frequĂȘncia escolar dos meninos, o que pode estar associado a diferenças de gĂȘnero nos custos de oportunidades do investimento em capital humano no meio rural

    Enhanced recovery after surgery: are we ready, and can we afford not to implement these pathways for patients undergoing radical cystectomy?

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    Enhanced recovery after surgery (ERAS) for radical cystectomy seems logical, but our study has shown a paucity in the level of clinical evidence. As part of the ERAS Society, we welcome global collaboration to collect evidence that will improve patient outcomes
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