Effects of Berberine, Chelerythrine, and Sanguinarine on Proliferation in Four Human Immortalized Cell Lines

Bloodroot (Sanguinaria canadensis L., Papaveraceae) is a plant rich in benzophenanchridine (isoquinoline) alkaloids such as sanguinarine and chelerychrine. Both isolated alkaloids and whole-tissue rhizome extracts have demonstrated in vitro anticarcinogenic (antiproliferacive) activity in limited immortalized cell culture models, but the relative contribution of various alkaloid constituents to whole-tissue extract activity, and whether or not various alkaloids may act synergistically, has not been investigated. We challenged four immortalized cell lines (Jurkat, K562, Ramos, U937) with various doses of chelerythrine, sanguinarine, and berberine (a structurally and functionally similar alkaloid absent from bloodroot), alone and in all possible combinations, and measured proliferation rates 48 hours pose-treatment. K562 cells were unaffected by all doses of berberine and chelerychrine tested, but showed anti proliferative activity at 0.5 µg/mL sanguinarine. The doses of sanguinarine necessary to elicit anti-proliferative effects in these experiments matched well with chose seen in whole-tissue rhizome extracts demonstrating similar anti-proliferative effects. When a 2 µg/mL dose of sanguinarine was tested in all four cell lines, sanguinarine elicited even stronger antiproliferative effects in Jurkat, Ramos, and U937 cells compared to K562 cells; these three cell lines also demonstrated reduced proliferation in the presence of chelerythrine at a dose of 1 µg/mL whereas K562 did not. At the doses tested here, berberine had no direct effect on proliferation. These results suggest that sanguinarine may be responsible for the bulk of anticarcinogenic activity from bloodroot whole-tissue rhizome extracts, but that ocher alkaloids such as chelerythrine may also play important roles contingent on cell typ

Evaluating markers of epithelial-mesenchymal transition to identify cancer patients at risk for metastatic disease

Most cancer deaths are due to metastases. Markers of epithelial-mesenchymal transition (EMT) measured in primary tumor cancer cells could be helpful to assess patient risk of metastatic disease, even among those otherwise diagnosed with local disease. Previous studies of EMT markers and patient outcomes used inconsistent methods and did not compare the clinical impact of different expression cut points for the same marker. Using digital image analysis, we measured the EMT markers Snail and E-cadherin in primary tumor specimens from 190 subjects in tissue microarrays from a population-based prospective cohort of colorectal cancer patients and estimated their associations with time-to-death. After measuring continuous marker expression data, we performed a systematic search for the cut point for each marker with the best model fit between dichotomous marker expression and time-to-death. We also assessed the potential clinical impact of different cut points for the same marker. After dichotomizing expression status at the statistically-optimal cut point, we found that Snail expression was not associated with time-to-death. When measured as a weighted average of tumor cores, low E-cadherin expression was associated with a greater risk of dying within 5 years of surgery than high expression (risk difference = 33 %, 95 % confidence interval 3–62 %). Identifying a clinically-optimal cut point for an EMT marker requires trade-offs between strength and precision of the association with patient outcomes, as well as consideration of the number of patients whose treatments might change based on using the marker at a given cut point

A Stop Codon in Xeroderma Pigmentosum Group C Families in Turkey and Italy: Molecular Genetic Evidence for a Common Ancestor

Xeroderma pigmentosum family G from Van, Turkey had two severely affected children: a son with multiple skin cancers who died at age 10 (XP67TMA), and an 8 y old daughter who began developing skin cancer before 3 y of age (XP68TMA). XP67TMA and XP68TMA cells were hypersensitive to killing by ultraviolet and the post-ultraviolet DNA repair level was 12–16% of normal. Host cell reactivation of an ultraviolet-treated reporter plasmid cotransfected with a vector expressing wild-type XPC cDNA assigned XP67TMA to xeroderma pigmentosum complementation group C. The XPC mRNA level was markedly reduced. Sequencing of the 3.5 kb XPC cDNA from XP67TMA showed a C–T mutation in XPC exon 8 at base pair 1840. This mutation converts the CGA codon of arginine at amino acid 579 to a UGA stop codon resulting in marked truncation of the 940 amino acid xeroderma pigmentosum C protein. Restriction fragment length polymorphism analysis of XPC exon 8 DNA in XP67TMA and XP68TMA showed that both affected children had a homozygous mutation and that both parents had heterozygous normal and mutated sequences at the same position consistent with a history of consanguinity in the family. The mutated allele also contained two XPC single nucleotide polymorphisms. The same mutated XPC allele was reported in an Italian family. Studies of 19 microsatellite markers flanking the XPC gene on chromosome 3 suggest that the XPC allele passed between Italy and Turkey approximately 300–500 y ago. This XPC allele containing a nonsense mutation is associated with severe clinical disease with multiple skin cancers and early death

Toy Model for a Relational Formulation of Quantum Theory

In the absence of an external frame of reference physical degrees of freedom must describe relations between systems. Using a simple model, we investigate how such a relational quantum theory naturally arises by promoting reference systems to the status of dynamical entities. Our goal is to demonstrate using elementary quantum theory how any quantum mechanical experiment admits a purely relational description at a fundamental level, from which the original "non-relational" theory emerges in a semi-classical limit. According to this thesis, the non-relational theory is therefore an approximation of the fundamental relational theory. We propose four simple rules that can be used to translate an "orthodox" quantum mechanical description into a relational description, independent of an external spacial reference frame or clock. The techniques used to construct these relational theories are motivated by a Bayesian approach to quantum mechanics, and rely on the noiseless subsystem method of quantum information science used to protect quantum states against undesired noise. The relational theory naturally predicts a fundamental decoherence mechanism, so an arrow of time emerges from a time-symmetric theory. Moreover, there is no need for a "collapse of the wave packet" in our model: the probability interpretation is only applied to diagonal density operators. Finally, the physical states of the relational theory can be described in terms of "spin networks" introduced by Penrose as a combinatorial description of geometry, and widely studied in the loop formulation of quantum gravity. Thus, our simple bottom-up approach (starting from the semi-classical limit to derive the fully relational quantum theory) may offer interesting insights on the low energy limit of quantum gravity.Comment: References added, extended discussio

Invasive potential of cattle fever ticks in the southern United States

Background For >100 years cattle production in the southern United States has been threatened by cattle fever. It is caused by an invasive parasite-vector complex that includes the protozoan hemoparasites Babesia bovis and B. bigemina, which are transmitted among domestic cattle via Rhipicephalus tick vectors of the subgenus Boophilus. In 1906 an eradication effort was started and by 1943 Boophilus ticks had been confined to a narrow tick eradication quarantine area (TEQA) along the Texas-Mexico border. However, a dramatic increase in tick infestations in areas outside the TEQA over the last decade suggests these tick vectors may be poised to re-invade the southern United States. We investigated historical and potential future distributions of climatic habitats of cattle fever ticks to assess the potential for a range expansion. Methods We built robust spatial predictions of habitat suitability for the vector species Rhipicephalus (Boophilus) microplus and R. (B.) annulatus across the southern United States for three time periods: 1906, present day (2012), and 2050. We used analysis of molecular variance (AMOVA) to identify persistent tick occurrences and analysis of bias in the climate proximate to these occurrences to identify key environmental parameters associated with the ecology of both species. We then used ecological niche modeling algorithms GARP and Maxent to construct models that related known occurrences of ticks in the TEQA during 2001–2011 with geospatial data layers that summarized important climate parameters at all three time periods. Results We identified persistent tick infestations and specific climate parameters that appear to be drivers of ecological niches of the two tick species. Spatial models projected onto climate data representative of climate in 1906 reproduced historical pre-eradication tick distributions. Present-day predictions, although constrained to areas near the TEQA, extrapolated well onto climate projections for 2050. Conclusions Our models indicate the potential for range expansion of climate suitable for survival of R. microplus and R. annulatus in the southern United States by mid-century, which increases the risk of reintroduction of these ticks and cattle tick fever into major cattle producing areas.We thank USDA-APHIS mounted patrol inspectors for collecting field samples used in this study. This work was supported by USDA-NIFA Grant 2010-65104-20386. Use of trade, product, or firm names does not imply endorsement by the US Government. The USDA is an equal opportunity provider and employer

Overexpression of Rubisco subunits with RAF1 increases Rubisco content in maize.

Rubisco catalyses a rate-limiting step in photosynthesis and has long been a target for improvement due to its slow turnover rate. An alternative to modifying catalytic properties of Rubisco is to increase its abundance within C4 plant chloroplasts, which might increase activity and confer a higher carbon assimilation rate. Here, we overexpress the Rubisco large (LS) and small (SS) subunits with the Rubisco assembly chaperone RUBISCO ASSEMBLY FACTOR 1 (RAF1). While overexpression of LS and/or SS had no discernable impact on Rubisco content, addition of RAF1 overexpression resulted in a >30% increase in Rubisco content. Gas exchange showed a 15% increase in CO2 assimilation (ASAT) in UBI-LSSS-RAF1 transgenic plants, which correlated with increased fresh weight and in vitro Vcmax calculations. The divergence of Rubisco content and assimilation could be accounted for by the Rubisco activation state, which decreased up to 23%, suggesting that Rubisco activase may be limiting Vcmax, and impinging on the realization of photosynthetic potential from increased Rubisco content.This research was supported by the Agriculture and Food Research Initiative from the National Institute of Food and Agriculture, US Department of Agriculture, under award number 2016-67013-24464. Travel to the Australian National University was supported by the Mario Einaudi Center for International Studies, International Research Travel Grant at Cornell University

Flavor changing Z-decays from scalar interactions at a Giga-Z Linear Collider

The flavor changing decay Z -> d_I \bar{d}_J is investigated with special emphasis on the b \bar{s} final state. Various models for flavor violation are considered: two Higgs doublet models (2HDM's), supersymmetry (SUSY) with flavor violation in the up and down-type squark mass matrices and SUSY with flavor violation mediated by R-parity-violating interaction. We find that, within the SUSY scenarios for flavor violation, the branching ratio for the decay Z -> b \bar{s} can reach 10^{-6} for large \tan\beta values, while the typical size for this branching ratio in the 2HDM's considered is about two orders of magnitudes smaller at best. Thus, flavor changing SUSY signatures in radiative Z decays such as Z -> b \bar{s} may be accessible to future ``Z factories'' such as a Giga-Z version of the TESLA design.Comment: 27 pages, 15 figures, REVTeX4. A new section added and a few minor corrections were made in the tex

Noninvasive continuous optical monitoring of absolute cerebral blood flow in critically ill adults

We investigate a scheme for noninvasive continuous monitoring of absolute cerebral blood flow (CBF) in adult human patients based on a combination of time-resolved dynamic contrast-enhanced near-infrared spectroscopy (DCE-NIRS) and diffuse correlation spectroscopy (DCS) with semi-infinite head model of photon propogation. Continuous CBF is obtained via calibration of the DCS blood flow index (BFI) with absolute CBF obtained by intermittent intravenous injections of the optical contrast agent indocyanine green. A calibration coefficient (gamma) for the CBF is thus determined, permitting conversion of DCS BFI to absolute blood flow units at all other times. A study of patients with acute brain injury (N = 7) is carried out to ascertain the stability of gamma. The patient-averaged DCS calibration coefficient across multiple monitoring days and multiple patients was determined, and good agreement between the two calibration coefficients measured at different times during single monitoring days was found. The patient-averaged calibration coefficient of 1.24 x 10(9) (mL/100 g/min)/(cm(2)/s) was applied to previously measured DCS BFI from similar brain-injured patients||in this case, absolute CBF was underestimated compared with XeCT, an effect we show is primarily due to use of semi-infinite homogeneous models of the head.54115Agências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig

Time Pressure Modulates Electrophysiological Correlates of Early Visual Processing

BACKGROUND: Reactions to sensory events sometimes require quick responses whereas at other times they require a high degree of accuracy-usually resulting in slower responses. It is important to understand whether visual processing under different response speed requirements employs different neural mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: We asked participants to classify visual patterns with different levels of detail as real-world or non-sense objects. In one condition, participants were to respond immediately, whereas in the other they responded after a delay of 1 second. As expected, participants performed more accurately in delayed response trials. This effect was pronounced for stimuli with a high level of detail. These behavioral effects were accompanied by modulations of stimulus related EEG gamma oscillations which are an electrophysiological correlate of early visual processing. In trials requiring speeded responses, early stimulus-locked oscillations discriminated real-world and non-sense objects irrespective of the level of detail. For stimuli with a higher level of detail, oscillatory power in a later time window discriminated real-world and non-sense objects irrespective of response speed requirements. CONCLUSIONS/SIGNIFICANCE: Thus, it seems plausible to assume that different response speed requirements trigger different dynamics of processing