Figure 3. is expressed in the pulps of mice 19, 20 and human teeth 21. Interestingly, when stimulated Fmoc-Lys(Me3)-OH chloride with LTA Fmoc-Lys(Me3)-OH chloride All H & E and IHC stained sections were viewed under a light microscope (Leica DM5000B, Leica Microsystems, Wetzlar, Germany) under magnifications up to x100 objective. A cell was determined as immuno-positive when it demonstrated distinctive brown stain on the cell membrane and/or cytoplasm around a nucleus. Images were taken using a CCD camera (Leica DC500, Leica Microsystems, Wetzlar, Germany), mounted on the microscope, controlled by computer software ( Leica FireCam Version 1.5, Leica Microsystem, Heerbrugg, Switzerland). All IF stained sections were viewed under a fluorescence microscope (Olympus AX70, Olympus Corporation, Center Valley, PA, USA) under magnifications up to x100 objectives. Fmoc-Lys(Me3)-OH chloride Images were taken using the CMOS camera (Go-3, QImaging, Surrey, BC, Canada) mounted on the microscope and controlled by computer software ( Macintosh QCapture Suite, 2.98.2 QImaging, Surrey, BC, Canada). A cell was counted as positive when it demonstrated distinctive fluorescence on the cell membrane and/or Fmoc-Lys(Me3)-OH chloride cytoplasm surrounding the nucleus. Since the fluorescence microscope only observes one wavelength at a time, the separately labeled protein target and the nucleus cannot be observed simultaneously. To overcome this problem Photoshop (CS5 C 12.0 C White Rabbit – Adobe Systems Incorporated, San Jose, CA, USA) software was employed for qualitative analysis. An area of interest was photographed under different wavelength with the slide remaining stationary. Images were superimposed and screened using the Photoshop software to disclose positive cells. Qualitative analysis of the DIF followed the same principles as IF. A cell was identified to co-express two targeted proteins when the superimposed and screened images showed both green and red fluorescence on the cell membrane and/or cytoplasm. The objective of the DIF qualitative analysis was to identify TLR2 expressing cells as lymphocytes/plasma cells (CD38), Macrophages/monocytes (CD68) and/or mature dendritic cells (CD83). Results Histological examination The routine diagnostic H & E stained sections of the selected periapical granuloma lesions were retrieved from the histopathology-archived records. All tissue sections showed characteristics of granulation tissue ( Figure 1a, b, c), typically mature fibrous connective tissue with a moderately intense infiltrate of chronic inflammatory cells dominated by lymphocytes. Occasionally, strands of stratified squamous epithelium of odontogenic origin (epithelial rests of Malassez) were found interspersed in the granulation tissue of some lesions. In the periapical scar (negative tissue control) inflammatory cells were absent and the lesion was characteristically acellular, with the exception of fibroblasts associated with collagen, with a dense avascular collagen structure ( Figure 1d). Figure 1. Open in a separate window ( a) A histopathology section of a selected refractory periapical granuloma showing areas of fibrous connective tissue (F), blood vessels, inflammatory cells (I) and interspersed odontogenic epithelium (Haematoxylin & Eosin staining x50), ( b) Proliferating epithelial cells (E) surrounded by chronic inflammatory cells (I) (Haematoxylin & Eosin staining x200), ( c) Fibrous connective cells (F) with moderate chronic inflammatory cell infiltrate (I) (Haematoxylin & Eosin staining x200), ( d) Histopathology section of a periapical scar showing the un-inflamed, relatively acellular and avascular dense collagen cells (Haematoxylin & Eosin staining x200). Immunohistochemistry In the lingual tonsil section (positive control), clusters of lymphocytes within the germinal centres DLEU7 were positively stained and appeared as small circular or oval brownish cells that were closely packed collectively ( Number 2a). All the periapical granuloma samples showed CD38 + cells and experienced the same staining pattern as the CD38 + cells in the Fmoc-Lys(Me3)-OH chloride lingual tonsil. These CD38 + cells dominated the inflammatory cell infiltrate and were mostly found in large clusters equally distributed in the granulation cells with some individual positive cells spread in between ( Number 2a, b). A closer look of the CD38+ cells under high power magnification (x1000) exposed that the brownish stains were.