223 research outputs found
Role of Transferrin Receptor and the ABC Transporters ABCB6 and ABCB7 for Resistance and Differentiation of Tumor Cells towards Artesunate
The anti-malarial artesunate also exerts profound anti-cancer activity. The susceptibility of tumor cells to artesunate can be enhanced by ferrous iron. The transferrin receptor (TfR) is involved in iron uptake by internalization of transferrin and is over-expressed in rapidly growing tumors. The ATP-binding cassette (ABC) transporters ABCB6 and ABCB7 are also involved in iron homeostasis. To investigate whether these proteins play a role for sensitivity towards artesunate, Oncotest's 36 cell line panel was treated with artesunate or artesunate plus iron(II) glycine sulfate (Ferrosanol®). The majority of cell lines showed increased inhibition rates, for the combination of artesunate plus iron(II) glycine sulfate compared to artesunate alone. However, in 11 out of the 36 cell lines the combination treatment was not superior. Cell lines with high TfR expression significantly correlated with high degrees of modulation indicating that high TfR expressing tumor cells would be more efficiently inhibited by this combination treatment than low TfR expressing ones. Furthermore, we found a significant relationship between cellular response to artesunate and TfR expression in 55 cell lines of the National Cancer Institute (NCI), USA. A significant correlation was also found for ABCB6, but not for ABCB7 in the NCI panel. Artesunate treatment of human CCRF-CEM leukemia and MCF7 breast cancer cells induced ABCB6 expression but repressed ABCB7 expression. Finally, artesunate inhibited proliferation and differentiation of mouse erythroleukemia (MEL) cells. Down-regulation of ABCB6 by antisense oligonucleotides inhibited differentiation of MEL cells indicating that artesunate and ABCB6 may cooperate. In conclusion, our results indicate that ferrous iron improves the activity of artesunate in some but not all tumor cell lines. Several factors involved in iron homeostasis such as TfR and ABCB6 may contribute to this effect
Desire and Dread from the Nucleus Accumbens: Cortical Glutamate and Subcortical GABA Differentially Generate Motivation and Hedonic Impact in the Rat
Background: GABAergic signals to the nucleus accumbens (NAc) shell arise from predominantly subcortical sources whereas glutamatergic signals arise mainly from cortical-related sources. Here we contrasted GABAergic and glutamatergic generation of hedonics versus motivation processes, as a proxy for comparing subcortical and cortical controls of emotion. Local disruptions of either signals in medial shell of NAc generate intense motivated behaviors corresponding to desire and/or dread, along a rostrocaudal gradient. GABA or glutamate disruptions in rostral shell generate appetitive motivation whereas disruptions in caudal shell elicit fearful motivation. However, GABA and glutamate signals in NAc differ in important ways, despite the similarity of their rostrocaudal motivation gradients. Methodology/Principal Findings: Microinjections of a GABAA agonist (muscimol), or of a glutamate AMPA antagonist (DNQX) in medial shell of rats were assessed for generation of hedonic ‘‘liking’ ’ or ‘‘disliking’ ’ by measuring orofacial affective reactions to sucrose-quinine taste. Motivation generation was independently assessed measuring effects on eating versus natural defensive behaviors. For GABAergic microinjections, we found that the desire-dread motivation gradient was mirrored by an equivalent hedonic gradient that amplified affective taste ‘‘liking’ ’ (at rostral sites) versus ‘‘disliking’ ’ (at caudal sites). However, manipulation of glutamatergic signals completely failed to alter pleasure-displeasure reactions to sensory hedonic impact, despite producing a strong rostrocaudal gradient of motivation
Preferential binding to dopamine D3 over D2 receptors by cariprazine in patients with schizophrenia using PET with the D3/D2 receptor ligand [11C]-(+)-PHNO
Structural Characteristics and Stellar Composition of Low Surface Brightness Disk Galaxies
We present UBVI surface photometry of a sample of low surface brightness
(LSB) disk galaxies. LSB disk galaxies are fairly well described as exponential
disks with no preferred value for either scale length, central surface
brightness, or rotational velocity. Indeed, the distribution of scale lengths
is indistinguishable from that of high surface brightness spirals, indicating
that dynamically similar galaxies (e.g., those with comparable Rv^2) exist over
a large range in surface density.
These LSB galaxies are strikingly blue. The complete lack of correlation
between central surface brightness and color rules out any fading scenario.
Similarly, the oxygen abundances inferred from HII region spectra are
uncorrelated with color so the low metallicities are not the primary cause of
the blue colors. While these are difficult to interpret in the absence of
significant star formation, the most plausible scenario is a stellar population
with a young mean age stemming from late formation and subsequent slow
evolution.
These properties suggest that LSB disks formed from low initial overdensities
with correspondingly late collapse times.Comment: Astronomical Journal, in press 45 pages uuencoded postscript (368K)
including 9 multipart figures also available by anonymous ftp @
ftp.ast.cam.ac.uk /pub/ssm/phot.uu CAP-30-210442962983742937
Technology-Enhanced Formative Assessment: A Research-Based Pedagogy for Teaching Science with Classroom Response Technology
Mild-to-moderate kidney dysfunction and cardiovascular disease: observational and mendelian randomization analyses.
BACKGROUND: End-stage renal disease is associated with a high risk of cardiovascular events. It is unknown, however, whether mild-to-moderate kidney dysfunction is causally related to coronary heart disease (CHD) and stroke. METHODS: Observational analyses were conducted using individual-level data from 4 population data sources (Emerging Risk Factors Collaboration, EPIC-CVD [European Prospective Investigation into Cancer and Nutrition-Cardiovascular Disease Study], Million Veteran Program, and UK Biobank), comprising 648 135 participants with no history of cardiovascular disease or diabetes at baseline, yielding 42 858 and 15 693 incident CHD and stroke events, respectively, during 6.8 million person-years of follow-up. Using a genetic risk score of 218 variants for estimated glomerular filtration rate (eGFR), we conducted Mendelian randomization analyses involving 413 718 participants (25 917 CHD and 8622 strokes) in EPIC-CVD, Million Veteran Program, and UK Biobank. RESULTS: There were U-shaped observational associations of creatinine-based eGFR with CHD and stroke, with higher risk in participants with eGFR values 105 mL·min-1·1.73 m-2, compared with those with eGFR between 60 and 105 mL·min-1·1.73 m-2. Mendelian randomization analyses for CHD showed an association among participants with eGFR 105 mL·min-1·1.73 m-2. Results were not materially different after adjustment for factors associated with the eGFR genetic risk score, such as lipoprotein(a), triglycerides, hemoglobin A1c, and blood pressure. Mendelian randomization results for stroke were nonsignificant but broadly similar to those for CHD. CONCLUSIONS: In people without manifest cardiovascular disease or diabetes, mild-to-moderate kidney dysfunction is causally related to risk of CHD, highlighting the potential value of preventive approaches that preserve and modulate kidney function
The Neural Basis of Cognitive Efficiency in Motor Skill Performance from Early Learning to Automatic Stages
Accordance and conflict between religious and scientific precautions against COVID-19 in 27 societies
Meaning-making systems underlie perceptions of the efficacy of threat-mitigating behaviors. Religion and science both offer threat mitigation, yet these meaning-making systems are often considered incompatible. Do such epistemological conflicts swamp the desire to employ diverse precautions against threats? Or do individuals—particularly individuals who are highly reactive to threats—hedge their bets by using multiple threat-mitigating practices despite their potential epistemological incompatibility? Complicating this question, perceptions of conflict between religion and science likely vary across cultures; likewise, pragmatic features of precautions prescribed by some religions make them incompatible with some scientifically-based precautions. The COVID-19 pandemic elicited diverse precautions thus providing an opportunity to investigate these questions. Across 27 societies from five continents (N = 7,844), in the majority of countries, individuals’ practice of religious precautions such as prayer correlates positively with their use of scientifically-based precautions. Prior work indicates that greater adherence to tradition likely reflects greater reactivity to threats. Unsurprisingly given associations between many traditions and religion, valuing tradition is predictive of employing religious precautions. However, consonant with its association with threat reactivity, we also find that traditionalism predicts adherence to public health precautions—a pattern that underscores threat-avoidant individuals’ apparent tolerance for epistemological conflict in pursuit of safety
Intra-subject repeatability of in vivo intervertebral motion parameters using quantitative fluoroscopy.
Purpose: In vivo quantification of intervertebral motion through imaging has progressed to a point where biomarkers for low back pain are emerging. This makes possible deeper study of the condition’s biometrics. However, the measurement of change over time involves error. The purpose of this prospective investigation is to determine the intra-subject repeatability of six in vivo intervertebral motion parameters using quantitative fluoroscopy. Methods: Intra-subject reliability (ICC) and minimal detectable change (MDC) of baseline to 6-week follow-up measurements were calculated for 6 lumbar spine intervertebral motion parameters in 109 healthy volunteers. A standardised quantitative fluoroscopy (QF) protocol was used to provide measurements in the coronal and sagittal planes using both passive recumbent and active weight bearing motion. Parameters were: intervertebral range of motion (IV-RoM), laxity, motion sharing inequality (MSI), motion sharing variability (MSV), flexion translation, and anterior disc height change during flexion. Results: The best overall intra subject reliability (ICC) and agreement (MDT) were for disc height (ICC 0.89, MDC 43%) and IV-RoM (ICC 0.96, MDC 60%) and the worst for MSV (ICC 0.04, MCD 408%). Laxity, MSI and translation had acceptable reliability (most ICCs >0.60), but not agreement (MDC >85%). Conclusion: Disc height and IV-RoM measurement using QF could be considered for randomised trials while laxity, MSI and translation could be considered for moderators, correlates or mediators of patient reported outcomes. MSV had both poor reliability and agreement over 6 weeks
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