Characterization of mouse macrophage differentiation antigens by monoclonal antibodies

Monoclonal rat antibodies to mouse macrophage antigens were prepared. For immunization phagocytic cells in the spleens of mice recovering from sublethal irradiation were used. Specificities of the monoclonal antibodies obtained were determined on cells of normal mouse cell populations as well as on cells of a panel of mouse cell lines. In an attempt to monitor expression of differentiation-related antigens two models of in vitro-induced macrophage differentiation were used: differentiation of cells of the myeloblast line M1; CSF-1 -induced differentiation of bone marrow cells. The results obtained clearly show that during maturation from undifferentiated to highly differentiated cells of the macrophage lineage expression of antigens recognized by the MIV 38, MIV 55, MV 87, and MV 114 monoclonal antibodies is enhanced. At the same time, expression of antigens recognized by the MIV 52, MIV 113, and MIV 116 monoclonal antibodies diminishes at a similar rate. The suitability of these monoclonal antibodies for the characterization of differentiation states of mouse macrophages is discussed

The 180 splice variant of NCAM-containing exon 18-is specifically expressed in small cell lung cancer cells

Background: The Neural Cell Adhesion Molecule (NCAM) is a glycoprotein expressed as 120, 140 and/or 180 kDa isoforms, all derived through alternative splicing of a single gene. NCAM 120 contains no intracellular domain, whereas NCAM 140 and 180 have different intracellular domains determined by alternative splicing of exon 18. NCAM has been described as a biomarker to discriminate small cell lung cancer (SCLC) from non-SCLC (NSCLC). However, peripheral blood mononuclear cells (PBMC) also express NCAM. We studied the expression of NCAM splice variants in cell lines, tumor tissues and control cells. Methods: Using reverse transcriptase-PCR we evaluated the expression of NCAM exon 18 splice variants in lung cancers cell lines, control cell lines, PBMC of healthy controls and SCLC tissue. In addition we studied the expression of the NCAM exon 18 encoded protein (E18) in SCLC by immunocytochemistry and flow cytometry using an E18-specific monoclonal antibody obtained by hybridoma fusion of E18-immunized mouse spleen cells. Finally we looked at immune responses to E18 in mice. Results: We found expression of RNA encoding the NCAM 180 variant in all SCLC cell lines. NCAM exon 18 was not expressed in 23/28 (82%) of the other tumor and leukemia cell lines tested and PBMC. Next, we also evaluated the expression of NCAM exon 18 in human SCLC tissue. Expression of NCAM exon 18 in 8 of the 10 (80%) SCLC biopsy samples was found. The newly raised E18-specific antibodies stained NCAM at the adherent junctions between adjacent cells in SCLC cell lines. The data demonstrate the intracellular location of E18 in SCLC. Furthermore, a specific cytotoxic T cell (CTL) response and significant antibody titers were found in mice upon immunization with recombinant E18 and its encoding DNA. Conclusions: The results of this study can be applied in the diagnosis and immunotherapy of SCLC. A larger study investigating E18 as a marker for SCLC is indicated

Hard x-ray nanofocusing by refractive lenses of constant thickness

In order to focus light or x rays, the thickness of a refractive lens is typically varied over its aperture. Here, we present a refractive x-ray lens made of lamellae of constant thickness, the refractive lamellar lens. Refractive power is created by a specific bending of the lamellae rather than by a concave lens profile. This very special design has the technological advantage that materials like sapphire or diamond can be used to make lenses by coating techniques. A first lens prototype focused x rays with a photon energy E = 15.25 keV to a lateral beam size of 164 nm x 296 nm full width at half maximum

Focusing hard x rays beyond the critical angle of total reflection by adiabatically focusing lenses

In response to the conjecture that the numerical aperture of x-ray optics is fundamentally limited by the critical angle of total reflection [Bergemann et al., Phys. Rev. Lett. 91, 204801 (2003)], the concept of adiabatically focusing refractive lenses was proposed to overcome this limit [Schroer and Lengeler, Phys. Rev. Lett. 94, 054802 (2005)]. We present an experimental realization of these optics made of silicon and demonstrate that they indeed focus 20 keV x rays to a 18.4 nm focus with a numerical aperture of 1.73(9) × 10$^{−3}$ that clearly exceeds the critical angle of total reflection of 1.55 mrad

3D and Multimodal X-Ray Microscopy Reveals the Impact of Voids in CIGS Solar Cells

Small voids in the absorber layer of thin-film solar cells are generally suspected to impair photovoltaic performance. They have been studied on Cu(In,Ga)Se2 cells with conventional laboratory techniques, albeit limited to surface characterization and often affected by sample-preparation artifacts. Here, synchrotron imaging is performed on a fully operational as-deposited solar cell containing a few tens of voids. By measuring operando current and X-ray excited optical luminescence, the local electrical and optical performance in the proximity of the voids are estimated, and via ptychographic tomography, the depth in the absorber of the voids is quantified. Besides, the complex network of material-deficit structures between the absorber and the top electrode is highlighted. Despite certain local impairments, the massive presence of voids in the absorber suggests they only have a limited detrimental impact on performance