172 research outputs found
Enhancing Thermal Tolerance By Eliminating The Pejus Range: A Comparative Study With Three Decapod Crustaceans
Marine invertebrates in the intertidal and subtidal zones are often exposed to highly variable environmental conditions, especially rapid changes in temperature. The ability to survive at different temperatures has previously been described using an extended version of Shelford’s law of tolerance, with optimum, pejus (Latin: ‘turning worse’), and pessimum ranges, and the respective thresholds, critical (Tc) and pejus (Tp) temperatures, that mark the transition from one range into the next. The width of the pejus range, in which the scope for activity gradually declines, varies among species. We tested the hypothesis that the width of the pejus range is correlated to the temperature stability of the species’ respective habitats. We used locomotor activity, heart rate, lactate accumulation, heat shock protein 70 (HSP70) levels, and the activation of AMP-activated protein kinase (AMPK) to identify Tc and Tp in 3 decapod crustaceans: green crab Carcinus maenas, rock crab Cancer irroratus, and lobster Homarus americanus. We found species specific patterns of temperature-induced changes in all parameters, especially in HSP70 protein and AMPK activity. The width of the pejus range (between Tp and Tc) was 8 to 12°C for rock crabs and 12 to 16°C for lobsters. Most importantly, green crab, the most temperature-tolerant of our 3 species and which lives in a highly variable habitat, switched directly from optimum to pessimum range, meaning that the pejus range was eliminated completely. Additionally, even lethal temperatures did not activate AMPK in green crabs, pointing to a different cellular tolerance strategy than in rock crabs and lobsters. This modified tolerance pattern might represent a broader strategy to enhance physiological tolerance in a highly variable habitat
Digit ratios by computer-assisted analysis confirm lack of anatomical evidence of prenatal androgen exposure in clinical phenotypes of polycystic ovary syndrome
<p>Abstract</p> <p>Background</p> <p>We recently showed that women with four clinical phenotypes of polycystic ovary syndrome (PCOS) do not demonstrate anatomical evidence of elevated prenatal androgen exposure as judged by a lower ratio of the index (2D) to ring (4D) finger. However, those findings conflicted with a previous study where women with PCOS had lower right hand 2D:4D compared to healthy female controls. Both these studies used Vernier calipers to measure finger lengths - a method recently shown to be less reliable at obtaining finger length measurements than computer-assisted analysis.</p> <p>Methods</p> <p>Ninety-six women diagnosed with PCOS according to the 2003 Rotterdam criteria had their finger lengths measured with computer-assisted analysis. Participants were categorized into four recognized phenotypes of PCOS and their 2D:4D compared to healthy female controls (n = 48) and men (n = 50).</p> <p>Results</p> <p>Digit ratios assessed by computer-assisted analysis in women with PCOS did not differ from female controls, but were significantly lower in men. When subjects were stratified by PCOS phenotype, 2D:4D did not differ among phenotypes or when compared to female controls.</p> <p>Conclusion</p> <p>Computer-assisted measurements validated that digit ratios of women with PCOS do not show anatomical evidence of increased prenatal androgen exposure.</p
Nano-Motion Analysis for Rapid and Label Free Assessing of Cancer Cell Sensitivity to Chemotherapeutics.
Background and Objectives: Optimization of chemotherapy is crucial for cancer patients. Timely and costly efficient treatments are emerging due to the increasing incidence of cancer worldwide. Here, we present a methodology of nano-motion analysis that could be developed to serve as a screening tool able to determine the best chemotherapy option for a particular patient within hours. Materials and Methods: Three different human cancer cell lines and their multidrug resistant (MDR) counterparts were analyzed with an atomic force microscope (AFM) using tipless cantilevers to adhere the cells and monitor their nano-motions. Results: The cells exposed to doxorubicin (DOX) differentially responded due to their sensitivity to this chemotherapeutic. The death of sensitive cells corresponding to the drop in signal variance occurred in less than 2 h after DOX application, while MDR cells continued to move, even showing an increase in signal variance. Conclusions: Nano-motion sensing can be developed as a screening tool that will allow simple, inexpensive and quick testing of different chemotherapeutics for each cancer patient. Further investigations on patient-derived tumor cells should confirm the method's applicability
Resistance to DNA Damaging agents produced invasive phenotype of rat glioma cells-characterization of a new in vivo model
Chemoresistance and invasion properties are severe limitations to efficient glioma therapy. Therefore, development of glioma in vivo models that more accurately resemble the situation observed in patients emerges. Previously, we established RC6 rat glioma cell line resistant to DNA damaging agents including antiglioma approved therapies such as 3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and temozolomide (TMZ). Herein, we evaluated the invasiveness of RC6 cells in vitro and in a new orthotopic animal model. For comparison, we used C6 cells from which RC6 cells originated. Differences in cell growth properties were assessed by real-time cell analyzer. Cells’ invasive potential in vitro was studied in fluorescently labeled gelatin and by formation of multicellular spheroids in hydrogel. For animal studies, fluorescently labeled cells were inoculated into adult male Wistar rat brains. Consecutive coronal and sagittal brain sections were analyzed 10 and 25 days post-inoculation, while rats’ behavior was recorded during three days in the open field test starting from 25th day post-inoculation. We demonstrated that development of chemoresistance induced invasive phenotype of RC6 cells with significant behavioral impediments implying usefulness of orthotopic RC6 glioma allograft in preclinical studies for the examination of new approaches to counteract both chemoresistance and invasion of glioma cells
Quasiparticle scattering and local density of states in the d-density wave phase
We study the effects of single-impurity scattering on the local density of
states in the high- cuprates. We compare the quasiparticle interference
patterns in three different ordered states: d-wave superconductor (DSC),
d-density wave (DDW), and coexisting DSC and DDW (DSC-DDW). In the coexisting
state, at energies below the DSC gap, the patterns are almost identical to
those in the pure DSC state with the same DSC gap. However, they are
significantly different for energies greater than or equal to the DSC gap. This
transition at an energy around the DSC gap can be used to test the nature of
the superconducting state of the underdoped cuprates by scanning tunneling
microscopy. Furthermore, we note that in the DDW state the effect of the
coherence factors is stronger than in the DSC state. The new features arising
due to DDW ordering are discussed.Comment: 6 page, 5 figures (Higher resolution figures are available by
request
PTPRF is disrupted in a patient with syndromic amastia
<p>Abstract</p> <p>Background</p> <p>The presence of mammary glands distinguishes mammals from other organisms. Despite significant advances in defining the signaling pathways responsible for mammary gland development in mice, our understanding of human mammary gland development remains rudimentary. Here, we identified a woman with bilateral amastia, ectodermal dysplasia and unilateral renal agenesis. She was found to have a chromosomal balanced translocation, 46,XX,t(1;20)(p34.1;q13.13). In addition to characterization of her clinical and cytogenetic features, we successfully identified the interrupted gene and studied its consequences.</p> <p>Methods</p> <p>Characterization of the breakpoints was performed by molecular cytogenetic techniques. The interrupted gene was further analyzed using quantitative real-time PCR and western blotting. Mutation analysis and high-density SNP array were carried out in order to find a pathogenic mutation. Allele segregations were obtained by haplotype analysis.</p> <p>Results</p> <p>We enabled to identify its breakpoint on chromosome 1 interrupting the <it>protein tyrosine receptor type F gene </it>(<it>PTPRF</it>). While the patient's mother and sisters also harbored the translocated chromosome, their non-translocated chromosomes 1 were different from that of the patient. Although a definite pathogenic mutation on the paternal allele could not be identified, <it>PTPRF</it>'s RNA and protein of the patient were significantly less than those of her unaffected family members.</p> <p>Conclusions</p> <p>Although <it>ptprf </it>has been shown to involve in murine mammary gland development, no evidence has incorporated <it>PTPRF </it>in human organ development. We, for the first time, demonstrated the possible association of <it>PTPRF </it>with syndromic amastia, making it a prime candidate to investigate for its spatial and temporal roles in human breast development.</p
Characterization of Engineered Actin Binding Proteins That Control Filament Assembly and Structure
Eukaryotic cells strictly regulate the structure and assembly of their actin filament networks in response to various stimuli. The actin binding proteins that control filament assembly are therefore attractive targets for those who wish to reorganize actin filaments and reengineer the cytoskeleton. Unfortunately, the naturally occurring actin binding proteins include only a limited set of pointed-end cappers, or proteins that will block polymerization from the slow-growing end of actin filaments. Of the few that are known, most are part of large multimeric complexes that are challenging to manipulate.We describe here the use of phage display mutagenesis to generate of a new class of binding protein that can be targeted to the pointed-end of actin. These proteins, called synthetic antigen binders (sABs), are based on an antibody-like scaffold where sequence diversity is introduced into the binding loops using a novel "reduced genetic code" phage display library. We describe effective strategies to select and screen for sABs that ensure the generated sABs bind to the pointed-end surface of actin exclusively.From our set of pointed-end binders, we identify three sABs with particularly useful properties to systematically probe actin dynamics: one protein that caps the pointed end, a second that crosslinks actin filaments, and a third that severs actin filaments and promotes disassembly
Chapter 9 Moral Responsibility and the Justification of Policies to Preserve Antimicrobial Effectiveness
Restrictive policies that limit antimicrobial consumption, including therapeutically
justified use, might be necessary to tackle the problem of antimicrobial
resistance. We argue that such policies would be ethically justified when forgoing
antimicrobials constitutes a form of easy rescue for an individual. These are cases
of mild and self-limiting infections in otherwise healthy patients whose overall
health is not significantly compromised by the infection. In such cases, restrictive
policies would be ethically justified because they would coerce individuals into fulfilling
a moral obligation they independently have. However, to ensure that such
justification is the strongest possible, states also have the responsibility to ensure
that forgoing antimicrobials is as easy as possible for patients by implementing
adequate compensation measures
A New Strategy for Glioblastoma Treatment: In Vitro and In Vivo Preclinical Characterization of Si306, a Pyrazolo[3,4-d]Pyrimidine Dual Src/P-Glycoprotein Inhibitor
20siopenOverexpression of P-glycoprotein (P-gp) and other ATP-binding cassette (ABC) transporters in multidrug resistant (MDR) cancer cells is responsible for the reduction of intracellular drug accumulation, thus decreasing the efficacy of chemotherapeutics. P-gp is also found at endothelial cells' membrane of the blood-brain barrier, where it limits drug delivery to central nervous system (CNS) tumors. We have previously developed a set of pyrazolo[3,4-d]pyrimidines and their prodrugs as novel Src tyrosine kinase inhibitors (TKIs), showing a significant activity against CNS tumors in in vivo. Here we investigated the interaction of the most promising pair of drug/prodrug with P-gp at the cellular level. The tested compounds were found to increase the intracellular accumulation of Rho 123, and to enhance the efficacy of paclitaxel in P-gp overexpressing cells. Encouraging pharmacokinetics properties and tolerability in vivo were also observed. Our findings revealed a novel role of pyrazolo[3,4-d]pyrimidines which may be useful for developing a new effective therapy in MDR cancer treatment, particularly against glioblastoma.openFallacara, Anna Lucia; Zamperini, Claudio; Podolski-Renić, Ana; Dinić, Jelena; Stanković, Tijana; Stepanović, Marija; Mancini, Arianna; Rango, Enrico; Iovenitti, Giulia; Molinari, Alessio; Bugli, Francesca; Sanguinetti, Maurizio; Torelli, Riccardo; Martini, Maurizio; Maccari, Laura; Valoti, Massimo; Dreassi, Elena; Botta, Maurizio; Pešić, Milica; Schenone, SilviaFallacara, Anna Lucia; Zamperini, Claudio; Podolski-Renić, Ana; Dinić, Jelena; Stanković, Tijana; Stepanović, Marija; Mancini, Arianna; Rango, Enrico; Iovenitti, Giulia; Molinari, Alessio; Bugli, Francesca; Sanguinetti, Maurizio; Torelli, Riccardo; Martini, Maurizio; Maccari, Laura; Valoti, Massimo; Dreassi, Elena; Botta, Maurizio; Pešić, Milica; Schenone, Silvi
- …