640 research outputs found
Evaluation of Three Rapid Tests for Diagnosis of P. Falciparum and P. Vivax Malaria in Colombia.
The diagnostic capacity of three malaria rapid diagnostic tests (RDTs), NOW-Malaria-ICT, OptiMAL-IT, and Paracheck-Pf, was evaluated against expert microscopy in Colombia. We tested 896 patients, of whom microscopy confirmed 139 P. falciparum, 279 P. vivax, and 13 mixed P.f/P.v infections and 465 negatives. Paracheck-Pf and NOW-malaria-ICT were more accurate in detecting P. falciparum (sensitivities 90.8% and 90.1%, respectively) in comparison with Optimal-IT (83.6%). NOW showed an acceptable Pf detection rate at low densities (< 500/microL), but resulted in a higher proportion of false positives. For P. vivax diagnosis, Optimal-IT had a higher sensitivity than NOW (91.0% and 81.4%, respectively). The choice between the two Pf/Pv detecting RDTs balances P. falciparum and P. vivax detection rates. Considering some degree of P. falciparum overtreatment and failure to detect all P. vivax cases as more acceptable than missing some cases of P. falciparum, we recommend careful implementation of NOW-malaria-ICT in areas where microscopy is lacking. The price is however still a constraint
Autophagy-mediated degradation of nuclear envelope proteins during oncogene-induced senescence.
Cellular senescence is a largely irreversible form of cell cycle arrest triggered by various types of damage and stress, including oncogene expression (termed oncogene-induced senescence or OIS). We and others have previously demonstrated that OIS occurs in human benign lesions, acting as a potent tumor suppressor mechanism. Numerous phenotypic changes occur during OIS, both in the cytoplasm and in the nucleus. These include the activation of autophagy, a catabolic process operating in the cytoplasm and downregulation of lamin B1, a component of the nuclear lamina. However, it is unknown whether these changes relate to each other. We discovered that cells entering BRAF(V600E)- or H-RAS(G12V)-induced senescence downregulate not only lamin B1 but also lamin A, as well as several other nuclear envelope (NE) proteins, resulting in an altered NE morphology. Depletion of LMNB1 or LMNA/C was sufficient to recapitulate some OIS features, including cell cycle exit and downregulation of NE proteins. We further found that the global loss of NE proteins is a consequence of their degradation by the autophagy machinery, which occurs concomitantly with autophagy induction and increased lysosomal content and activity. Our study therefore reveals a previously unknown connection between autophagy and the disruption of NE integrity during OIS
Doxorubicin-induced DNA Damage Causes Extensive Ubiquitination of Ribosomal Proteins Associated with a Decrease in Protein Translation
Protein posttranslational modifications (PTMs) play a central role in the DNA damage response. In particular, protein phosphorylation and ubiquitination have been shown to be essential in the signaling cascade that coordinates break repair with cell cycle progression. Here, we performed whole-cell quantitative proteomics to identify global changes in protein ubiquitination that are induced by DNA double-strand breaks. In total, we quantified more than 9,400 ubiquitin sites and found that the relative abundance of similar to 10% of these sites was altered in response to DNA double-strand breaks. Interestingly, a large proportion of ribosomal proteins, including those from the 40S as well as the 60S subunit, were ubiquitinated in response to DNA damage. In parallel, we discovered that DNA damage leads to the inhibition of ribosome function. Taken together, these data uncover the ribosome as a major target of the DNA damage response.This work is funded by a TOP-GO grant from the Netherlands Organization for Scientific Research (NWO ZonMW 912100651 to R.H.M., S.M., and V.A.H.). I.G.S. was supported with a postdoctoral fellowship from the Basque Country Government (Spain). We thank Christian Frese and Teck Yew Low for fruitful discussions. We also thank Teck Yew Low for submitting the raw files and annotated spectra to PRIDE. We thank Fabricio Loayza-Puch for his technical help with the sucrose gradients
Massive IIA flux compactifications and U-dualities
We attempt to find a rigorous formulation for the massive type IIA
orientifold compactifications of string theory introduced in hep-th/0505160. An
approximate double T-duality converts this background into IIA string theory on
a twisted torus, but various arguments indicate that the back reaction of the
orientifold on this geometry is large. In particular, an AdS calculation of the
entropy suggests a scaling appropriate for N M2-branes, in a certain limit of
the compactification, though not the one studied in hep-th/0505160. The
M-theory lift of this specific regime is not 4 dimensional. We suggest that the
generic limit of the background corresponds to a situation analogous to
F-theory, where the string coupling is small in some regions of a compact
geometry, and large in others, so that neither a long wavelength 11D SUGRA
expansion, nor a world sheet expansion exists for these compactifications. We
end with a speculation on the nature of the generic compactification.Comment: JHEP3 LaTeX - 34 pages - 3 figures; v2: Added references; v3: mistake
in entropy scaling corrected, major changes in conclusions; v4: changed
claims about original DeWolfe et al. setup, JHEP versio
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