Enamel matrix derivative Emdogain® as an adjuvant for a laterally-positioned flap in the treatment of gingival recession: an electron microscopic appraisal

Enamel matrix derivative (EMD), such as Emdogain®, has been suggested for the improvement of wound healing in periodontal surgical therapy. The present qualitative study seeks to illustrate the ultrastructural changes associated with a human gingival wound at 10 days after the application of EMD as an adjunct to a laterally-positioned flap in a patient with gingival recession. An otherwise healthy patient, who had been suffering from bilateral gingival recession defects on teeth #23 and #26, was studied. One defect was treated with a laterally-positioned flap, while the other was treated with a combination of EMD and a laterally-positioned flap. Ten days after the operation gingival biopsy specimens were obtained from the dentogingival region and examined using a transmission electron microscope. A considerable difference was found in both the cellular and extracellular phases of EMD and non-EMD sites. The fibroblasts of EMD site were more rounded with plump cytoplasms and euchromatic nuclei. A well-developed rough endoplasmic reticulum and numerous mitochondria could be detected. In contrast, the fibroblasts of non-EMD site were of flattened spindle-like morphology. While the signs of apoptosis could rarely be detected at EMD site, apoptotic bodies and ultra-structural evidence of apoptosis (crescent-like heterochromatic nuclei and dilated nuclear envelopes) were consistent features at non-EMD site. The extracellular matrix at EMD site mainly consisted of well-organised collagen fibres, while non-EMD site contained sparse and incompletely-formed collagen fibres. Coccoid bacteria were noted within the extracellular matrix and neutrophils at non-EMD site. It seems that EMD may enhance certain features of gingival wound healing, which may be attributable to its anti-apoptotic, anti-bacterial or anti-inflammatory properties

Different characteristics of semiconducting glazed insulators at artificially polluted conditions

Semiconducting Glazed Insulators are one of the most efficiently used insulators in contaminant areas. Several electrical and mechan ical tests take place under electrical and mechanical rest s are carried out to foresee the operation of these insulators in regions with high pollution. In attention to plenty of such tests that each one is being tested with a special way and different electrical, mechanical and en vironmental specifications, adding the results up and analyzing them has a special importance. In this paper, comparing the operation of this kind of insulators with conventional porcelain insulators in different artificially polluted conditions and related indexes in determining the operation of these insulators in different conditions of pollution is achieved

Identifying Spatial Co-occurrence in Healthy and InflAmed tissues (ISCHIA)

Spatial transcriptomics techniques are able to chart the distribution and localization of cell types and RNA molecules across a tissue. Here, we generated matched sequencing-based (Visium) and hybridization-based (Molecular Cartography) spatial transcriptomics data of human IBD samples. We then developed ISCHIA (Identifying Spatial Co-occurrence in Healthy and InflAmed tissues), a computational framework to analyze the spatial co-occurrence of cell types and transcript species in the tissue environment. ISCHIA revealed tightly associated cellular networks, ligand-receptor interactions enriched in the inflamed human colon, and their associated gene signatures, highlighting the hypothesis-generating power of co-occurrence analysis on spatial transcriptomics data

In vivo screening of tumor-hepatocyte interactions identifies Plexin B2 as a gatekeeper of liver metastasis

It is estimated that only 0.02% of disseminated tumor cells are able to seed overt metastases1. While this indicates the presence of environmental constraints to metastatic seeding, the landscape of host factors controlling this process remains largely unknown. Combining transposon technology2 and fluorescent niche labeling3, we developed an in vivo CRISPR activation screen to systematically investigate the influence of hepatocytes on metastatic seeding in the liver. Our approach enabled the identification of Plexin B2 as a critical host-derived regulator of metastasis. Plexin B2 upregulation in hepatocytes dramatically enhances grafting in colorectal and pancreatic cancer syngeneic models, and promotes seeding and survival of patient-derived organoids. Notably, ablation of Plexin B2 in hepatocytes prevents mesenchymal-to-epithelial transition of extravasated tumor cells and thereby almost entirely suppresses liver metastasis. We dissect a mechanism by which Plexin B2 interacts with class 4 semaphorins on tumor cells, activating Rac1 signaling and actin cytoskeleton remodeling, thereby promoting the acquisition of epithelial traits. Our findings highlight the essential role of signals from the liver parenchyma for the survival of disseminated tumor cells, prior to the establishment of a growth promoting niche. They further suggest that acquisition of epithelial traits is required for the adaptation of extravasated cells to their new tissue environment. Targeting of Plexin B2 on hepatocytes shields the liver from colonizing cells and thus presents an innovative therapeutic strategy for preventing metastasis. Finally, our screening technology, which evaluates host-derived extrinsic signals rather than tumor-intrinsic factors for their ability to promote metastatic seeding, is broadly applicable and lays a framework for the screening of environmental constraints on metastasis in other organs and cancer types