The Pathophysiological Link between Right Atrial Remodeling and Functional Tricuspid Regurgitation in Patients with Atrial Fibrillation: A Three-Dimensional Echocardiography Study

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Recombinant human ADAMTS13 treatment and anti‐NET strategies enhance skin allograft survival in mice

Enhancing skin allograft longevity lessens the need for new allografts before optimal intervention is available. Reduced activity of ADAMTS13 (an enzyme that cleaves the pro‐thrombotic and proinflammatory von Willebrand factor) and presence of neutrophil extracellular traps (NETs) have been implicated in liver and lung allograft failures. The effect of ADAMTS13 treatment and the impact of NETs on skin allografts, however, remain unexplored. Here, we adopted a murine model of complete mismatch full‐thickness skin transplant by grafting dorsal skin from BALB/c mice to C57BL/6J background mice. Recombinant human ADAMTS13 (rhADAMTS13) treatment of graft recipients increased allograft survival. Western blot and immunofluorescence microscopy revealed the presence of NETs in allografts of vehicle, but surprisingly, not in rhADAMTS13‐treated mice, 3 days after surgery. Recapitulating the observations in mice, NETs were also observed in all the examined allografts from burn patients. Intriguingly, knocking out peptidylarginine deiminase 4 (PAD4, a key enzyme for NET formation) or DNase 1 treatment (which cleaves NETs) also prolonged allograft survival. In summary, rhADAMTS13 lessens inflammation in allografts by reducing NET burden, resulting in enhanced allograft survival. RhADAMTS13 and anti‐NET treatments could be new therapeutic strategies to promote skin allograft longevity and, hence, the survival of patients with severe burns.     

Paratesticular cystadenomas with ovarian stroma,metaplastic serous müllerian epithelium,and male adnexal tumor of probable wolffian origin: A series of 5 hitherto poorly recognized testicular tumors

We present 5 paratesticular tumors, which manifested ovarian-type stroma and various serous müllerian epithelial structures including serous fallopian-like epithelium and proliferations closely mimicking cystic serous borderline tumors of the ovary. In addition, 3 of the tumors in our series revealed a solid epithelial component, which was morphologically and immunohistochemically similar to so called “female adnexal tumor of probable wolffian origin,” which is a rare neoplasm described so far only in the female genital tract, retroperitoneum, and the pelvic cavity. In analogy with mixed epithelial and stromal tumors of the kidney, which are renal neoplasms producing ovarian-type stroma, we suggest to designate the above paratesticular tumors containing ovarian-type stroma as “mixed epithelial and stromal tumors of the paratestis with features of cystic serous borderline tumor” (cases 1 and 2) and “mixed epithelial and stromal tumors of the paratestis with male adnexal tumor of probable wolffian origin” (cases 3-5).     

Desmoplastic melanoma: an updated immunohistochemical analysis of 40 cases with a proposal for an additional panel of stains for diagnosis

Desmoplastic melanoma (DM) is histologically characterized by a proliferation of spindle melanocytes dispersed in a collagenous stroma that can be mistaken for a variety of neoplasms. The purpose of this study was to analyze 40 cases of DM with a comprehensive panel of immunohistochemical markers (KBA.62, p16, Ezrin, WT‐1, MITF‐1, SOX‐10, CD117, SOX‐2, nestin, PNL2, p75, MART‐1, gp100 and S100p) to obtain a more complete understanding of the potential use of these antibodies in the diagnosis of DM. We found that all cases of DM expressed p16, WT‐1, SOX‐10, nestin and S100p and 95% of cases expressed p75. There was variable expression with Ezrin, SOX‐2, KBA.62, MART‐1 and HMB‐45. Most DMs did not express MITF‐1, PNL2 and CD117. Conditions that may enter in the histologic differential diagnosis of DM, including dermal scars, fibromatosis and dermatofibromas were also studied. Nearly all control cases also stained positive for p16 but were negative for WT1, SOX10, nestin, p75 and S‐100p, as well as for most of the other markers tested. We conclude that a panel of S‐100p, WT1, SOX10, p75 and nestin may constitute the optimal panel with the most sensitive and specific combination of immunostain available for the diagnosis of DM.     

Autologous mesenchymal stem cells applied on the pressure ulcers had produced a surprising outcome in a severe case of neuromyelitis optica

Recent studies provided evidence that mesenchymal stem cells (MSCs) have regenerative potential in cutaneous repair and profound immunomodulatory properties making them a candidate for therapy of neuroimmunologic diseases. Neuromyelitis optica (NMO) is an autoimmune, demyelinating central nervous system disorder characterized by a longitudinally extensive spinal cord lesion. A 46-year-old male diagnosed with NMO had relapses with paraplegia despite treatment and developed two stage IV pressure ulcers (PUs) on his legs. The patient consented for local application of autologous MSCs on PUs. MSCs isolated from the patient''s bone marrow aspirate were multiplied in vitro during three passages and embedded in a tridimensional collagen-rich matrix which was applied on the PUs. Eight days after MSCs application the patient showed a progressive healing of PUs and improvement of disability. Two months later the patient was able to walk 20 m with bilateral assistance and one year later he started to walk without assistance. For 76 months the patient had no relapse and no adverse event was reported. The original method of local application of autologous BM-MSCs contributed to healing of PUs. For 6 years the patient was free of relapses and showed an improvement of disability. The association of cutaneous repair, sustained remission of NMO and improvement of disability might be explained by a promotion/optimization of recovery mechanisms in the central nervous system even if alternative hypothesis should be considered. Further studies are needed to assess the safety and efficacy of mesenchymal stem cells in NMO treatment.     

In vitro function and phagocytosis of galactosylated platelet concentrates after long-term refrigeration

BACKGROUND: Short-term refrigeration of platelets (PLTs) in the absence of plasma results in their rapid clearance after transfusion. Blocking beta-N-acetylglucosamine (beta-GlcNAc) residues of glycoprotein Ibalpha (GPIbalpha) with galactose prevents binding of refrigerated human and mouse PLTs to macrophages and prolongs the circulation times of refrigerated mouse PLTs. PLT-associated galactosyltransferase efficiently galactosylates chilled PLTs in the presence of its substrate UDP-galactose is added to PLT-rich plasma. STUDY DESIGN AND METHODS: To characterize the hemostatic function of refrigerated and galactosylated human PLTs processed in the blood bank, PLT aggregation was studied in vitro under static and flow conditions and expression of integrin beta3 (CD61), CD62P (P-selectin), GPIbalpha (CD42b), annexin V binding, and integrin alphaIIbeta3 activation with flow cytometry. Affinity of macrophages for galactosylated refrigerated PLTs was evaluated with THP-1 cells, which recognize and phagocytize refrigerated PLTs. RESULTS: PLTs refrigerated and galactosylated for 14 days 1) maintained their ability to aggregate when exposed to agonists in a standard aggregometry assay, 2) showed less pronounced changes in surface expression of GPIbalpha compared with room temperature (RT)-stored PLTs, 3) increased P-selectin expression, and 4) were poorly phagocytized by differentiated THP-1 cells in vitro. In addition, it is shown that refrigeration of PLTs does not affect their adhesive properties under in vitro flow conditions. CONCLUSION: It is shown that refrigerated human PLTs retain in vitro function better than RT PLTs during storage and demonstrate that galactosylation prevents recognition of stored refrigerated PLTs by macrophages in vitro.