Ferromagnetic material in the eastern red-spotted newt notophthalmus viridescens

Behavioral results obtained from the eastern red-spotted newt (Notophthalmus viridescens) led to the suggestion of a hybrid homing system involving inputs from both a light-dependent and a non-light-dependent mechanism. To evaluate the possible role of a receptor based on biogenic magnetite in this animal, we performed magnetometry experiments on a set of newts previously used in behavioral assays. The natural remanent magnetization (NRM) carried by these newts was strong enough to be measured easily using a direct-current-biased superconducting quantum interference device functioning as a moment magnetometer. Isothermal remanent magnetizations were two orders of magnitude higher than the NRM, suggesting that ferromagnetic material consistent with magnetite is present in the body of the newt. The NRM has no preferential orientation among the animals when analyzed relative to their body axis, and the demagnetization data show that, overall, the magnetic material grains are not aligned parallel to each other within each newt. Although the precise localization of the particles was not possible, the data indicate that magnetite is not clustered in a limited area. A quantity of single-domain magnetic material is present which would be adequate for use in either a magnetic intensity or direction receptor. Our data, when combined with the functional properties of homing, suggest a link between this behavioral response and the presence of ferromagnetic material, raising the possibility that magnetite is involved at least in the map component of homing of the eastern red-spotted newt

A 23 kDa membrane glycoprotein bearing NeuNAcα2-3Galβ1-3GalNAc O-linked carbohydrate chains acts as a receptor for Streptococcus sanguis OMZ 9 on human buccal epithelial cells

Streptococcus sanguis colonizes several human oral surfaces, including both hard and soft tissues. Large salivary mucin like glycoproteins bearing sialic acid residues are known to bind various S.sanguis strains. However, the molecular basis for the adhesion of S.sanguis to human buccal epithelial cells (HBEC) has not been established. The present study shows that S.sanguis OMZ 9 binds to exfoliated HBEC in a sialic acid-sensitive manner. The desialylation of such cells invariably abolhhes adhesion of S.sanguis OMZ 9 to the cell surface. A soluble glycopeptide bearing short sialylated O-linked carbohydrate chains behaves as a potent inhibitor of the attachment of S.sanguis OMZ 9 to exfoliated HBEC. The resialylation of desialylated HBEC with CMP-sialic acid and Galβ1,3GalNAc α2,3-sialyltransferase specific for O-glycans restores the receptor function for S.sanguis OMZ 9, whereas a similar cell resialylation with the Galβ1,4GlcNAc α2,6-sialyltmnsferase specific for N-glycans is without effect. Finally, ceinyl-sialic acid as a substrate yeilds exfoliated HBFC bearing flurescence as the catalyst. The latter finding demonstrates that this 23kDa cell surface glycoprotein bears NeuNAcα2-3Galβ1-3GalNAc O-linked sugar chains, a carbohydrate sequence which is recongnized by S.sanguis OMZ 9 on exfoliated HBEC. In similar experiments carried out with a buccal carcinoma cell line termed SqCC/Y1 S.sanguis OMZ 9 did not attach in great numbers to such cultured cells, and these cells were shown to not express membrane glycoprotien bearing α2,3-sialylated O-linked carbohydrate chain

Patient-centric structural determinants of adherence rates among asthma populations: Exploring the potential of patient activation and encouragement tool TRUSTR to improve adherence

Background: Lack of adherence with prescribed medications among the asthma populations exacerbates health outcomes and increases social and economic costs. Objectives: The proposed study aims to model patient-centric structural determinants of adherence rates among asthma patients and explore the potential of mobile health apps such as the TRUSTR platform to improve adherence using its power of monetary and non-monetary chatbotting and non-monetary nudges. Following specific hypotheses are tested: (1) Patient attributes, such as their age and medical condition, have significant effect on their adherence with the prescribed treatment plans. (2) Behavioral nudging with rewards and engagement via mobile health apps will increase adherence rates. Methods: The patient population (N = 37 359) consists of commercially insured patients with asthma who have been identified from administrative claims in the HealthCore Integrated Research Database (HIRD) between April 1, 2018 and March 31, 2019. Two Structural Equation Models (SEMs) are estimated to quantify direct, indirect, and total effect sizes of age and medical condition on proportion of days covered (PDC) and medical possession ratio (MPR), mediated by patient medical and pharmacy visits. Fourteen additional SEMs were estimated to lateralize TRUSTR findings and conduct sensitivity analysis. Results: HIRD data reveal mean adherence rate of 59% (standard deviation (SD) 29%) for PDC and 58% for MPR (SD 36%). Key structural findings from SEMs derived from the HIRD dataset indicate that each additional year in the age of the patient has a positive total effect on the adherence rate. Patients with poor medical condition are likely to have lower adherence rate, but this direct effect is countered by mediating variables. Further, each additional reward and higher engagement with a mobile app is likely to have a positive total effect on increasing the adherence rate. Conclusions: HIRD data reveal mean adherence rate of 59% (SD 29%), providing the evidence for the opportunity to increase adherence rate by around 40%. Statistical modeling results reveal structural determinants, such as the opportunity to nudge, are higher among younger patients, as they have higher probability of being non-adherent. Methodologically, lateralization approach demonstrates the potential to capture real-world evidence beyond clinical data and merge it with clinical data

In vitro irradiation of basement membrane enhances the invasiveness of breast cancer cells

Following removal of the primary breast tumour by conservative surgery, patients may still have additional malignant foci scattered throughout the breast. Radiation treatments are not designed to eliminate all these residual cancer cells. Rather, the radiation dose is calculated to optimise long-term results with minimal complications. In a tumour, cancer cells are surrounded by a basement membrane, which plays an important role in the regulation of gene expression. Using an invasion chamber, we have shown that irradiation before cell plating of a reconstituted basement membrane (Matrigel; Becton Dickinson, Bedford, MA, USA) increased the invasiveness of the breast cancer cells MDA-MB-231. This radiation enhancement of invasion was associated with the upregulation of the pro-invasive gene matrix metalloproteinase (MMP)-2. The expression of membrane type 1 matrix metalloproteinase (MT1-MMP) and tissue inhibitor of metalloproteinase-2 (TIMP), which are required to activate the MMP-2, were also increased. Confirming the role of MMP-2 and MT1-MMP, radiation enhancement of cancer cell invasion was prevented by an MMP-2 inhibitor and an anti-MT1-MMP antibody. This study also demonstrated that radiation can potentially enhance the invasion ability by inducing the release of pro-invasive factors stored in the Matrigel. Conversely, no enhancement of invasiveness was observed with the low metastatic cell line MCF-7. This lack of invasiveness correlated with the absence of the MMP-2 activator MT1-MMP in the MCF-7 cells. Radiotherapy is an efficient modality to treat breast cancer which could be further improved by inhibiting the pro-invasive gene upregulated by radiation

The G-Quadruplex Ligand Telomestatin Impairs Binding of Topoisomerase IIIα to G-Quadruplex-Forming Oligonucleotides and Uncaps Telomeres in ALT Cells

In Alternative Lengthening of Telomeres (ALT) cell lines, specific nuclear bodies called APBs (ALT-associated PML bodies) concentrate telomeric DNA, shelterin components and recombination factors associated with telomere recombination. Topoisomerase IIIα (Topo III) is an essential telomeric-associated factor in ALT cells. We show here that the binding of Topo III to telomeric G-overhang is modulated by G-quadruplex formation. Topo III binding to G-quadruplex-forming oligonucleotides was strongly inhibited by telomestatin, a potent and specific G-quadruplex ligand. In ALT cells, telomestatin treatment resulted in the depletion of the Topo III/BLM/TRF2 complex and the disruption of APBs and led to the segregation of PML, shelterin components and Topo III. Interestingly, a DNA damage response was observed at telomeres in telomestatin-treated cells. These data indicate the importance of G-quadruplex stabilization during telomere maintenance in ALT cells. The function of TRF2/Topo III/BLM in the resolution of replication intermediates at telomeres is discussed

Automatic detection of chemotaxis cells in angiogenesis process

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Algorithms of image processing for the automatic detection of blood cells in a matrigel (In-Vitro culture)

International audienceThe aim of the project is to develop a method, based on the process of cell division, able to quantify the vascularization area for the research on the angiogenesis phenomena. After having collected enough information to have a general view on the subject, a new method in terms of concept and philosophy will be developed

Processing with omnidirectional vision sensors (some examples)

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