Regulation of protein synthesis and autophagy in activated dendritic cells: implications for antigen processing and presentation

Antigenic peptides presented in the context of major histocompatibility complex (MHC) molecules originate from the degradation of both self and non-self proteins. T cells can therefore recognize at the surface of surveyed cells, the self-peptidome produced by the cell itself (mostly inducing tolerance) or immunogenic peptides derived from exogenous origins. The initiation of adaptive immune responses by dendritic cells (DCs), through the antigenic priming of naïve T cells, is associated to microbial pattern recognition receptors engagement. Activation of DCs by microbial product or inflammatory cytokines initiates multiple processes that maximize DC capacity to present exogenous antigens and stimulate T cells by affecting major metabolic and membrane traffic pathways. These include the modulation of protein synthesis, the regulation of MHC and co-stimulatory molecules transport, as well as the regulation of autophagy, that, all together promote exogenous antigen presentation while limiting the display of self-antigens by MHC molecules.     

The thymus and skin wound healing in Xenopus laevis adults

The capacity to heal wounds without scars is generally lost during the development in vertebrates. To explore the involvement of cells of the adaptive immune system in a scar-like tissue based repair, we studied the thymus in 15-month-old Xenopus after skin incisional wounding. After injury, the organ size significantly increased and marked changes in structure and TNF-α immunoreactivity were detected in the medullary microenvironment when the granulation tissue was present in the repair area. Most of the lymphocytes present in this wound connective tissue were found to be immunoreactive to specific T cell markers. Thymic mucocyte-like cells and epithelial cysts increased in number, the myoid cells acquired a faster turnover and associated in large clusters, blood vessels were dilated and corpuscles similar to mammalian Hassall's bodies were formed in medulla. A higher number of stronger medullary TNF-α immunoreactive cells, i.e., dendritic, epithelial, granular basophilic and myoid cells were also induced after wounding. With progression of healing the thymus gradually returned to histochemical patterns of controls. Our results suggest that during the scar-based skin repair of Xenopus adults the activity of the thymus may be stimulated and associated with the T lymphocyte infiltration observed into injured granulation tissue.     

KISS1 metastasis suppression and emergent pathways

Metastatic disease is the most critical impediment to cancer patient survival. However, comparatively little is known concerning the intricate pathways which govern the complex phenotypes associated with metastasis. The KISS1 metastasis suppressor gene inhibits metastasis in both in vivo melanoma and breast carcinoma models. Despite its clear physiological activity, the mechanism of KISS1 remains unclear. Recent identification of a 54 amino acid peptide of KISS1, termed metastin or kisspeptin-54, and its cognate G-protein coupled receptor (hOT7T175, AXOR12, GPR54) have provided additional clues and avenues of research. While studies have attributed KISS1 with modulation of NFκB regulation, experiments with metastin and its receptor implicate MAP kinase pathways and also suggest the potential of autocrine, paracrine and endocrine roles. Impacts on motility, chemotaxis, adhesion and invasion have each been documented in disparate cell lines and conflicting observations require resolution. Nevertheless, mounting clinical evidence, particularly the loss of KISS1 in metastases, correlates KISS1 and metastin receptor expression with human tumor progression. Together, the data substantiate roles for these molecules in metastasis regulation.     

Blue rubber bleb nevus: an uncommon cause of intestinal intussusception

The blue rubber bleb nevus syndrome or Bean syndrome is a rare disorder characterized by cutaneous and gastrointestinal vascular malformations. A 5-year-old girl with Bean syndrome hospitalized in a pediatric unit came under our observation with abdominal pain and vomiting. An X-ray of the abdomen showed an intestinal occlusion and an ultrasonography showed a suspected intestinal invagination. She underwent emergency laparoscopic surgery using three trocars. Laparoscopy revealed a huge ascitis and multiple vascular lesions located on the loops and on the parietal peritoneum, and we identified also an ileo-ileal invagination. We performed a laparoscopic disinvagination that showed one huge vascular lesion producing the invagination and causing a stenosis of intestinal lumen. We performed an intestinal resection after exteriorizing the loops through the umbilicus as well as a termino-terminal ileal anastomosis. Conclusions: Our case shows that an intestinal invagination due to Bean syndrome is extremely rare in pediatric patients but possible. In the emergency, laparoscopy seems to be a safe and effective procedure to confirm the diagnosis and to perform the disinvagination mini-invasivally. In addition, laparoscopy permits to have a clear picture of other intra-abdominal lesions linked to Bean syndrome.     

Validity of SF-12 summary scores in a Greek general population

Background  

The 12-item Health Survey (SF-12) was developed as a shorter alternative to the SF-36 for use in large-scale studies, particularly when overall physical and mental health are the outcomes of interest instead of the typical eight-scale profile. The main purpose of this study was to assess the validity of the Greek version of the SF-12.     

Case report: Rectal adminstration of ivermectin to a patient with Strongyloides hyperinfection syndrome

Strongyloides hyperinfection syndrome may be complicated by paralytic ileus that interferes with the absorption of oral anti-helminthics. We report on the administration of ivermectin as a rectal enema preparation to a renal transplant recipient with Strongyloides hyperinfection syndrome and progressive ileus. Attempts at treatment using nasogastric albendazole and ivermectin were unsuccessful despite clamping the nasogastric tube after drug administration. Ivermectin tablets were ground to a powder, resuspended in a commercially available suspending agent, and administered per rectum. The suspending agent was chosen for its near-physiologic osmolality to allow longer retention, in contrast to many enema preparations that have a laxative effect. The patient improved markedly within 72 hours of initiation of the therapy per rectum and recovered fully. Ivermectin administered as an enema may be beneficial in patients with severe strongyloidiasis who are unable to absorb or tolerate oral therapy.     

Transendothelial function of human metastatic melanoma cells: role of the microenvironment in cell-fate determination

On the basis of the ability of aggressive melanoma cells to participate in vasculogenic mimicry, particularly their expression of endothelial-associated genes, we examined the plasticity of human metastatic cutaneous melanoma cells with respect to vascular function. Fluorescently labeled metastatic melanoma cells were challenged to an ischemic microenvironment surgically induced in the hind limbs of nude mice. The data reveal the capability of these melanoma cells to express cell-fate determination molecules, normally expressed during embryonic vasculogenesis, and to participate in the neovascularization of circulation-deficient muscle. These results demonstrate the powerful influence of the microenvironment on the transendothelial differentiation of aggressive melanoma cells, and may provide new perspectives on tumor cell plasticity that could be exploited for novel therapeutic strategies.