Wood Species for the Biedermeier Furniture - A Microscopic Characterisation for Scientific Conservation

Wood species identification is an important, compulsory step in the scientific conservation of the historic furniture as a significant part of the cultural heritage. It is known that a visual examination of an investigated sample does not always bring enough information about the original species and that a microscopic approach is more reliable. Species identification can be performed if the microscopic images are interpreted for common, but also for specific features and characteristics, by means of identification keys and in comparison with reference images. This paper provides the microscopic characterization with identification keys for six hardwood species, some of the most common in Biedermeier furniture (elm - Ulmus glabra Huds., cherry - Prunus avium L., walnut - Juglans regia L.,pear - Pyrus communis L., aspen - Populus tremula L., African mahogany - Khaya ivorensis A. Chev.). The characterization can be used for wood identification purposes by laboratories working in the field of cultural heritage wood conservation. This work is part of a recent research project that aims to develop and implement a scientific investigation for furniture conservation

Image processing method as a supporting tool for wood species identification

Examination of wood sections using microscopy is often not very satisfactory for species identifcation, and this may be the case for samples taken from objects needing restoration. This could be caused by various parameters, namely the small size of the section, condition of the section related to its age or degradation, finishes penetrating the wood material as well as sections not covering a representative area to have an objective and accurate wood identification. An image analysis method based on ImageJ, an image processing program intended for medical micrscopy, was used in this work. The method is useful for wood because it offers an objective quantitative way to separate and measure anatomical structures of the section allowing statistical analysis of the data to be carried out. This is a case study related to identifying samples from three furniture pieces needing restoration. Microslides were prepared from small samples of each furniture unit. These were observed with transmitted light microscopy. Each sample was identified by examining the microscopic images, which were interpreted for their common but also specific features and characteristics by means of ImageJ analysis and compared with reference microscopic images of known species and their characteristics provided by the literature. The species identified in this study were found to have diffuse pores. Further work should address more wood species, including softwoods, to check the usefulness of the image processing method on various situations and to understand its limitations

In situ demonstration of CD40- and CD154-positive cells in psoriatic lesions and keratinocyte production of chemokines by CD40 ligation in vitro.

Item does not contain fulltextIn psoriatic lesions, T cells and keratinocytes are in an activated state. Ligation of CD40 expressed on activated keratinocytes with CD154 expressed on activated T cells is thought to be involved in the pathogenesis of psoriasis. However, the presence of CD40(+) and CD154(+) cells in psoriatic skin has not been thoroughly studied. The present study has therefore examined their presence by immunohistochemistry in the lesional and non-lesional skin of ten patients. The influence of CD154-CD40 ligation on the release of chemokines (IL-8, RANTES, and MCP-1) and complement components (C3 and factor B) from keratinocytes was also investigated in vitro. Studies using single and double staining showed that clusters of CD40(+) keratinocytes were present in both lesional and non-lesional skin; CD40(+)CD1a(+) Langerhans cells in lesional, non-lesional, and normal skin; and numerous CD40(+)CD83(+) cells in lesional skin. CD1a(+) and CD83(+) cells always expressed CD40 strongly. Numerous T cells were seen in lesional skin. A small number of T cells expressed CD154. CD154(+) T cells were seen in the lesional epidermis of seven of ten patients-in six, in juxtaposition to CD40(+) cells including keratinocytes. In non-lesional epidermis, CD154(+) T cells were seen in two patients-in one, in juxtaposition to CD40(+) keratinocytes. In vitro studies showed that IFN-gamma-treated keratinocytes released small amounts of IL-8, RANTES, and MCP-1; ligation of these cells with CD154-transfected J558 cells or soluble CD154 greatly enhanced the release. This ligation did not enhance the release of C3 and factor B. These results warrant further studies on the role of CD40 ligation in the pathogenesis of psoriasis

Human keratinocytes produce the complement inhibitor factor H: synthesis is regulated by interferon-gamma.

Contains fulltext : 49860.pdf (publisher's version ) (Closed access)Locally synthesized complement is believed to play an important role in host defense and inflammation at organ level. In the epidermis, keratinocytes have so far been shown to synthesize two complement components, C3 and factor B. Here, we studied the synthesis of factor H by human keratinocytes. We also studied the regulation of factor H synthesis in keratinocytes by several cytokines, namely IL-1alpha, IL-2, IL-6, TGF-beta1, TNF-alpha and IFN-gamma. Human keratinocytes expressed factor H mRNA and constitutively released small amounts of factor H protein into the culture medium. This release was strongly upregulated by IFN-gamma but not by other cytokines tested. Western blot analysis revealed that IFN-gamma augments the synthesis of both molecular species, factor H (FH; 155kDa) and factor H-like protein-1 (FHL-1; 45kDa), of factor H. Factor H released in response to IFN-gamma was functionally active. In conclusion, we demonstrate that keratinocytes are capable of synthesizing factor H and that this synthesis is regulated by IFN-gamma