25 research outputs found

    Single beam grating coupled interferometry: high resolution miniaturized label-free sensor for plate based parallel screening

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    Grating Coupled Interferometry (GCI) using high quality waveguides with two incoupling and one outcoupling grating areas is introduced to increase and precisely control the sensing length of the device; and to make the sensor design suitable for plate-based multiplexing. In contrast to other interferometric arrangements, the sensor chips are interrogated with a single expanded laser beam illuminating both incoupling gratings simultaneously. In order to obtain the interference signal, only half of the beam is phase modulated using a laterally divided two-cell liquid crystal modulator. The developed highly symmetrical arrangement of the interferometric arms increases the stability and at the same time offers straightforward integration of parallel sensing channels. The device characteristics are demonstrated for both TE and TM polarized modes. (C)2012 Optical Society of Americ

    Beiträge zur Pathogenese der diffusen Glomerulonephritis : (Blutdruck- und Permeabilität Untersuchungen bei der Masuginephritis)

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    Die Ergebnisse unserer Untersuchungen zeigen also, da ß vor dem Ausbruch der experimentellen Glomerulonephritis zweifellos die Symptome eines allgemeinen Gefäßspasmus wahrzunehmen sind. Eine Schädigung der Capillaren, eine Zunahme der Permeabilität konnte nur in den Nieren nachgewiesen werden. Diese Ergebnisse unterstützten keineswegs die extrarenale Theorie der Nephritis, und wir können folglich das Nephrotoxin nicht als allgemeines Gefäßgift betrachten, wie es von A. Weiß auf Grund histologischer Untersuchungen zur Erklärung der präalbuminären Blutdruckerhöhung angenommen wird. Vom praktischen Standpunk t aus heben wir die Bedeutung der frühzeitigen Wasserretention hervor, welche zu den Symptomen zu rechnen ist, die den Ausbruch einer diffusen Glomerulonephritis anzeigen

    Establishment and Characterization of a Brca1-/-, p53-/- Mouse Mammary Tumor Cell Line.

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    Breast cancer is the most commonly occurring cancer in women and the second most common cancer overall. By the age of 80, the estimated risk for breast cancer for women with germline BRCA1 or BRCA2 mutations is around 80%. Genetically engineered BRCA1-deficient mouse models offer a unique opportunity to study the pathogenesis and therapy of triple negative breast cancer. Here we present a newly established Brca1-/-, p53-/- mouse mammary tumor cell line, designated as CST. CST shows prominent features of BRCA1-mutated triple-negative breast cancers including increased motility, high proliferation rate, genome instability and sensitivity to platinum chemotherapy and PARP inhibitors (olaparib, veliparib, rucaparib and talazoparib). Genomic instability of CST cells was confirmed by whole genome sequencing, which also revealed the presence of COSMIC (Catalogue of Somatic Mutations in Cancer) mutation signatures 3 and 8 associated with homologous recombination (HR) deficiency. In vitro sensitivity of CST cells was tested against 11 chemotherapy agents. Tumors derived from orthotopically injected CST-mCherry cells in FVB-GFP mice showed sensitivity to cisplatin, providing a new model to study the cooperation of BRCA1-KO, mCherry-positive tumor cells and the GFP-expressing stromal compartment in therapy resistance and metastasis formation. In summary, we have established CST cells as a new model recapitulating major characteristics of BRCA1-negative breast cancers

    Pegylated liposomal formulation of doxorubicin overcomes drug resistance in a genetically engineered mouse model of breast cancer.

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    Success of cancer treatment is often hampered by the emergence of multidrug resistance (MDR) mediated by P-glycoprotein (ABCB1/Pgp). Doxorubicin (DOX) is recognized by Pgp and therefore it can induce therapy resistance in breast cancer patients. In this study our aim was to evaluate the susceptibility of the pegylated liposomal formulation of doxorubicin (PLD/Doxil(R)/Caelyx(R)) to MDR. We show that cells selected to be resistant to DOX are cross-resistant to PLD and PLD is also ineffective in an allograft model of doxorubicin-resistant mouse B-cell leukemia. In contrast, PLD was far more efficient than DOX as reflected by a significant increase of both relapse-free and overall survival of Brca1-/-;p53-/- mammary tumor bearing mice. Increased survival could be explained by the delayed onset of drug resistance. Consistent with the higher Pgp levels needed to confer resistance, PLD administration was able to overcome doxorubicin insensitivity of the mouse mammary tumors. Our results indicate that the favorable pharmacokinetics achieved with PLD can effectively overcome Pgp-mediated resistance, suggesting that PLD therapy could be a promising strategy for the treatment of therapy-resistant breast cancer patients
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