1,241 research outputs found
Rhabdomyolysis and Acute Renal Failure After Fire Ant Bites
We describe a 59-year-old patient who developed acute renal failure because of rhabdomyolysis after extensive red fire ant bites. This case illustrates a serious systemic reaction that may occur from fire ant bites. Consistent with the clinical presentation in rhabdomyolysis associated with non-traumatic causes, hyperkalemia, hypophosphatemia, hypocalcemia, and high anion gap acidosis were not observed in this patient. While local allergic reactions to fire ant bites are described in the literature, serious systemic complications with rhabdomyolysis and renal failure have not been previously reported. It is our effort to alert the medical community of the possibility of such a complication that can occur in the victims of fire ant bites
Drugs Associated with More Suicidal Ideations Are also Associated with More Suicide Attempts
In randomized controlled trials (RCTs), some drugs, including CB1 antagonists for obesity treatment, have been shown to cause increased suicidal ideation. A key question is whether drugs that increase or are associated with increased suicidal ideations are also associated with suicidal behavior, or whether drug-induced suicidal ideations are unlinked epiphenomena that do not presage the more troubling and potentially irrevocable outcome of suicidal behavior. This is difficult to determine in RCTs because of the rarity of suicidal attempts and completions.To determine whether drugs associated with more suicidal ideations are also associated with more suicide attempts in large spontaneous adverse event (AE) report databases.Generalized linear models with negative binomial distribution were fitted to Food and Drug Administration (FDA) Adverse Event (AE) Reporting System (AERS) data from 2004 to 2008. A total of 1,404,470 AEs from 832 drugs were analyzed as a function of reports of suicidal ideations; other non-suicidal adverse reactions; drug class; proportion of reports from males; and average age of subject for which AE was filed. Drug was treated as the unit of analysis, thus the statistical models effectively had 832 observations.Reported suicide attempts and completed suicides per drug.832 drugs, ranging from abacavir to zopiclone, were evaluated. The 832 drugs, as primary suspect drugs in a given adverse event, accounted for over 99.9% of recorded AERS. Suicidal ideations had a significant positive association with suicide attempts (p<.0001) and had an approximately 131-fold stronger magnitude of association than non-suicidal AERs, after adjusting for drug class, gender, and age.In AE reports, drugs that are associated with increased suicidal ideations are also associated with increased suicidal attempts or completions. This association suggests that drug-induced suicidal ideations observed in RCTs plausibly represent harbingers that presage the more serious suicide attempts and completions and should be a cause for concern
Why I tense up when you watch me: inferior parietal cortex mediates an audienceβs influence on motor performance
The presence of an evaluative audience can alter skilled motor performance through changes in force output. To investigate how this is mediated within the brain, we emulated real-time social monitoring of participantsβ performance of a fine grip task during functional magnetic resonance neuroimaging. We observed an increase in force output during social evaluation that was accompanied by focal reductions in activity within bilateral inferior parietal cortex. Moreover, deactivation of the left inferior parietal cortex predicted both inter- and intra-individual differences in socially-induced change in grip force. Social evaluation also enhanced activation within the posterior superior temporal sulcus, which conveys visual information about othersβ actions to the inferior parietal cortex. Interestingly, functional connectivity between these two regions was attenuated by social evaluation. Our data suggest that social evaluation can vary force output through the altered engagement of inferior parietal cortex; a region implicated in sensorimotor integration necessary for object manipulation, and a component of the action-observation network which integrates and facilitates performance of observed actions. Social-evaluative situations may induce high-level representational incoherence between oneβs own intentioned action and the perceived intention of others which, by uncoupling the dynamics of sensorimotor facilitation, could ultimately perturbe motor output
Higgs-mediated FCNCs: Natural Flavour Conservation vs. Minimal Flavour Violation
We compare the effectiveness of two hypotheses, Natural Flavour Conservation
(NFC) and Minimal Flavour Violation (MFV), in suppressing the strength of
flavour-changing neutral-currents (FCNCs) in models with more than one Higgs
doublet. We show that the MFV hypothesis, in its general formulation, is more
stable in suppressing FCNCs than the hypothesis of NFC alone when quantum
corrections are taken into account. The phenomenological implications of the
two scenarios are discussed analysing meson-antimeson mixing observables and
the rare decays B -> mu+ mu-. We demonstrate that, introducing flavour-blind CP
phases, two-Higgs doublet models respecting the MFV hypothesis can accommodate
a large CP-violating phase in Bs mixing, as hinted by CDF and D0 data and,
without extra free parameters, soften significantly in a correlated manner the
observed anomaly in the relation between epsilon_K and S_psi_K.Comment: 27 pages, 4 figures. v3: minor modifications (typos corrected and few
refs. added), conclusions unchanged; journal versio
Measurement of the charm structure function F_{2,c)^{Ξ³} of the photon at LEP
The production of charm quarks is studied in deep-inelastic electronβphoton scattering using data recorded by the OPAL detector at LEP at nominal eβΊeβ» centre-of-mass energies from 183 to 209 GeV. The charm quarks have been identified by full reconstruction of charged D* mesons using their decays into Dβ°Ο with the Dβ° observed in two decay modes with charged particle final states, KΟ and KΟΟΟ. The cross-section Ο^{D*} for production of charged D* in the reaction eβΊeβ»βeβΊeβ»D*Ξ§ is measured in a restricted kinematical region using two bins in Bjorken x, 0.00140.1 the perturbative QCD calculation at next-to-leading order agrees perfectly with the measured cross-section. For x<0.1 the measured cross-section is 43.8Β±14.3Β±6.3Β±2.8 pb with a next-to-leading order prediction of 17.0βΊΒ²Β·βΉ_β.β pb
The Non-Canonical CTD of RNAP-II Is Essential for Productive RNA Synthesis in Trypanosoma brucei
The carboxy-terminal domain (CTD) of the largest subunit (RPB1) of RNA polymerase II (RNAP-II) is essential for gene expression in metazoa and yeast. The canonical CTD is characterized by heptapeptide repeats. Differential phosphorylation of canonical CTD orchestrates transcriptional and co-transcriptional maturation of mRNA and snRNA. Many organisms, including trypanosomes, lack a canonical CTD. In these organisms, the CTD is called a non-canonical CTD or pseudo-CTD (Ξ¨CTD. In the African trypanosome, Trypanosoma brucei, the Ξ¨CTD is βΌ285 amino acids long, rich in serines and prolines, and phosphorylated. We report that T. brucei RNAP-II lacking the entire Ξ¨CTD or containing only a 95-amino-acid-long Ξ¨CTD failed to support cell viability. In contrast, RNAP-II with a 186-amino-acid-long Ξ¨CTD maintained cellular growth. RNAP-II with Ξ¨CTD truncations resulted in abortive initiation of transcription. These data establish that non-canonical CTDs play an important role in gene expression
Exceptionally Preserved Jellyfishes from the Middle Cambrian
Cnidarians represent an early diverging animal group and thus insight into their origin and diversification is key to understanding metazoan evolution. Further, cnidarian jellyfish comprise an important component of modern marine planktonic ecosystems. Here we report on exceptionally preserved cnidarian jellyfish fossils from the Middle Cambrian (βΌ505 million years old) Marjum Formation of Utah. These are the first described Cambrian jellyfish fossils to display exquisite preservation of soft part anatomy including detailed features of structures interpreted as trailing tentacles and subumbrellar and exumbrellar surfaces. If the interpretation of these preserved characters is correct, their presence is diagnostic of modern jellyfish taxa. These new discoveries may provide insight into the scope of cnidarian diversity shortly after the Cambrian radiation, and would reinforce the notion that important taxonomic components of the modern planktonic realm were in place by the Cambrian period
An Integrated Approach for the Analysis of Biological Pathways using Mixed Models
Gene class, ontology, or pathway testing analysis has become increasingly popular in microarray data analysis. Such approaches allow the integration of gene annotation databases, such as Gene Ontology and KEGG Pathway, to formally test for subtle but coordinated changes at a system level. Higher power in gene class testing is gained by combining weak signals from a number of individual genes in each pathway. We propose an alternative approach for gene-class testing based on mixed models, a class of statistical models that
Chemoattractant Signaling between Tumor Cells and Macrophages Regulates Cancer Cell Migration, Metastasis and Neovascularization
Tumor-associated macrophages are known to influence cancer progression by modulation of immune function, angiogenesis, and cell metastasis, however, little is known about the chemokine signaling networks that regulate this process. Utilizing CT26 colon cancer cells and RAW 264.7 macrophages as a model cellular system, we demonstrate that treatment of CT26 cells with RAW 264.7 conditioned medium induces cell migration, invasion and metastasis. Inflammatory gene microarray analysis indicated CT26-stimulated RAW 264.7 macrophages upregulate SDF-1Ξ± and VEGF, and that these cytokines contribute to CT26 migration in vitro. RAW 264.7 macrophages also showed a robust chemotactic response towards CT26-derived chemokines. In particular, microarray analysis and functional testing revealed CSF-1 as the major chemoattractant for RAW 264.7 macrophages. Interestingly, in the chick CAM model of cancer progression, RAW 264.7 macrophages localized specifically to the tumor periphery where they were found to increase CT26 tumor growth, microvascular density, vascular disruption, and lung metastasis, suggesting these cells home to actively invading areas of the tumor, but not the hypoxic core of the tumor mass. In support of these findings, hypoxic conditions down regulated CSF-1 production in several tumor cell lines and decreased RAW 264.7 macrophage migration in vitro. Together our findings suggest a model where normoxic tumor cells release CSF-1 to recruit macrophages to the tumor periphery where they secrete motility and angiogenic factors that facilitate tumor cell invasion and metastasis
Aptamer-based multiplexed proteomic technology for biomarker discovery
Interrogation of the human proteome in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology. We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 [mu]L of serum or plasma). Our current assay allows us to measure ~800 proteins with very low limits of detection (1 pM average), 7 logs of overall dynamic range, and 5% average coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding DNA aptamer concentration signature, which is then quantified with a DNA microarray. In essence, our assay takes advantage of the dual nature of aptamers as both folded binding entities with defined shapes and unique sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to discover unique protein signatures characteristic of various disease states. More generally, we describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine
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