Extended total arch replacement for type B aortic dissection with ascending aneurysm following healed aortic dissection

We describe a case of type B aortic dissection with large ascending aortic aneurysm occurring 12.8 years after aortic root replacement (Cabrol procedure) in a non-Marfan patient with cystic medial necrosis of the aorta. We have successfully performed an extended total aortic arch replacement using a four-branched graft through the “L-indsion” approach (a combination of a left anterior thoracotomy and upper half median sternotomy). Of note, a histological specimen from the aneurysmal ascending aortic wall revealed “healed aortic dissection” with fibrous tissue replacing the media and intima in addition to multiple foci of cystic medial necrosis.     

Effective in vitro clearance of Porphyromonas gingivalis by Fc alpha receptor I (CD89) on gingival crevicular neutrophils

Porphyromonas gingivalis has been implicated as a causative pathogen in periodontitis. Immunotherapeutic approaches have recently been suggested to aid in the clearance of P. gingivalis from disease sites. Because antibody-Fc receptor (FcR) interactions play a role in the effector functions of polymorphonuclear neutrophils (PMN), we evaluated which FcR on PMN from gingival crevicular fluid (GCF) serves as an optimal target molecule for FcR-directed immunotherapy. GCF PMN and peripheral blood (PB) PMN from adult periodontitis patients were analyzed for their immunoglobulin G (IgG) and IgA FcR (Fc gamma R and Fc alpha R, respectively) expression and function by studying IgG- and IgA-mediated elimination of P. gingivalis. GCF PMN exhibited higher Fc alpha RI and Fc gamma RI levels and lower Fc gamma RIIa and Fc gamma RIIIb levels than PB PMN. Functional studies revealed that GCF PMN exhibited less of a capacity to phagocytose and kill IgG1-opsonized P. gingivalis than PB PMN. IgA1-mediated phagocytosis and killing capacity was, however, comparable between GCF PMN and PB PMN. In summary, these in vitro results document that Fc alpha RI represents a candidate target for FcR-directed immunotherapy for the clearance of P. gingivalis.     

Comparison of human, simian, and bovine rotaviruses for requirement of sialic acid in hemagglutination and cell adsorption

Human rotaviruses (Wa, KUN, MO) showed hemagglutination (HA) only with fixed 1-day-old chicken erythrocytes, and their HA activities were completely destroyed by trypsin activation of virions. Simian SA-11 and bovine NCDV had HA activities not only against fixed erythrocytes but also against fresh erythrocytes from various species. Their HA activities against fixed erythrocytes were also inhibited by trypsin activation, but those against fresh erythrocytes were not. Neuraminidase treatment of fixed erythrocytes did not inhibit HA by trypsin-untreated rotaviruses. In contrast, HA of fresh human erythrocytes by SA-11 and NCDV was completely inhibited by neuraminidase treatment of erythrocytes or glycophorin A, the major erythrocyte sialoglycoprotein. Adsorption and infection of SA-11 and NCDV to monkey kidney MA104 cells were also inhibited by neuraminidase treatment of cells. Adsorption and infection of human rotaviruses were not, however, affected by treatment of cells with neuraminidase from Vibrio cholerae or Arthrobacter ureafaciens or with potassium periodate. Therefore, HA of fixed chicken erythrocytes by trypsin-untreated human and animal rotaviruses may be independent of sialic acids, whereas that of fresh erythrocytes by SA-11 and NCDV is sialic acid dependent and probably mediated by glycophorin A. Sialic acids also constitute an essential part of the cellular receptors for SA-11 and NCDV, whereas those for human rotaviruses were quite resistant to treatments known to destroy major types of sialic acids.     

Histological evidence of the altered distribution of osteocytes and bone matrix synthesis in klotho-deficient mice

Mice homozygous for klotho gene deletion are well established aging models as they mimic certain aspects of human senescence e.g. osteoporosis. Induced senescence may affect cellular functions and alter the histological properties of the extracellular matrices. The present study examined the histological and ultrastructural features of osteocytes and the surrounding bone matrix in klotho-deficient mice. As expected, osteoblasts showed a flattened shape with a weak immunoreactivity for alkaline phosphatase, and the bone matrix contained many empty osteocytic lacunae. The walls of both normal and empty lacunae were intensely immunopositive for osteopontin and dentin matrix protein-1, but featured an inconsistent immunoreactivity for osteocalcin and type I collagen. Not surprisingly, TUNEL-positivity, indicative of apoptosis, was found in many osteoblasts, osteocytes, and bone marrow cells of the klotho-deficient mice. In transmission electron microscopy, an amorphous matrix containing non-collagenous organic materials was recognizable around osteoblasts and in the osteocytic lacunae. Some osteoblasts on the bone surface featured these amorphous materials in vacuoles associated with their trans-Golgi network, indicating that, under klotho-deficient conditions, they synthesize and secrete the non-collagenous structures. Some osteocytes displayed pyknosis or degenerative traits. Thus, our findings provide histological evidence that klotho gene deletion influences the spatial distribution of osteocytes and the synthesis of bone matrix proteins in addition to the accelerated aging of bone cells.