Thrombin Induced Apoptosis through Calcium-Mediated Activation of Cytosolic Phospholipase A2 in Intestinal Myofibroblasts.

Thrombin is a serine protease that participates in a variety of biological signaling through protease-activated receptors. Intestinal myofibroblasts play central roles in maintaining intestinal homeostasis. In this study, we found that thrombin-induced apoptosis is mediated by the calcium-mediated activation of cytosolic phospholipase A2 in the CCD-18Co cell. Thrombin reduced cell viability by inducing apoptosis and proteinase-activated receptor-1 antagonist attenuated thrombin-induced cell death. Endogenous ceramide did not affect the cell viability itself, but a ceramide-mediated pathway was involved in thrombin-induced cell death. Thrombin increased intracellular calcium levels and cytosolic phospholipase A2 activity. The ceramide synthase inhibitor Fumonisin B1, intracellular calcium chelator BAPTA-AM, and cytosolic phospholipase A2 inhibitor AACOCF3 inhibited thrombin-induced cell death. Thrombin stimulated arachidonic acid release and reactive oxygen species generation, which was blocked by AACOCF3, BAPTA-AM, and the antioxidant reagent Trolox. Taken together, thrombin triggered apoptosis through calcium-mediated activation of cytosolic phospholipase A2 in intestinal myofibroblasts.

Collision tumor with inflammatory breast carcinoma and malignant phyllodes tumor: a case report and literature review.

There have been some reports of coincidental presentation of breast carcinoma and phyllodes tumor in the same breast. Most of the cases were carcinoma that arose from a phyllodes tumor with a histologically identified transitional area, and they behaved less aggressively than the usually encountered carcinoma. Collision tumors are rare clinical entities in which two histologically distinct tumor types show involvement at the same site. The occurrence of these tumors in the breast is extremely rare. Here, we report a case of 45-year-old woman who had both invasive ductal carcinoma as the finding of inflammatory carcinoma and a malignant phyllodes tumor in the same breast. There was no evidence of a transitional area between the phyllodes tumor and the invasive ductal carcinoma. To our knowledge, this is the first report of a collision tumor of inflammatory breast carcinoma coincident with a malignant phyllodes tumor in same breast.

Preparation and diagnostic utility of a hemagglutination inhibition test antigen derived from the baculovirus-expressed hemagglutinin-neuraminidase protein gene of Newcastle disease virus.

A recombinant hemagglutinin-neuraminidase (rHN) protein from Newcastle disease virus (NDV) with hemagglutination (HA) activity was expressed in Spodoptera frugiperda cells using a baculovirus expression system. The rHN protein extracted from infected cells was used as an antigen in a hemagglutination inhibition (HI) test for the detection and titration of NDV-specific antibodies present in chicken sera. The rHN antigen produced high HA titers of 2(13) per 25 µL, which were similar to those of the NDV antigen produced using chicken eggs, and it remained stable without significant loss of the HA activity for at least 12 weeks at 4°C. The rHN-based HI assay specifically detected NDV antibodies, but not the sera of other avian pathogens, with a specificity and sensitivity of 100% and 98.0%, respectively, in known positive and negative chicken sera (n = 430). Compared with an NDV-based HI assay, the rHN-based HI assay had a relative sensitivity and specificity of 96.1% and 95.5%, respectively, when applied to field chicken sera. The HI titers of the rHN-based HI assay were highly correlated with those in an NDV-based HI assay (r = 0.927). Overall, these results indicate that rHN protein provides a useful alternative to NDV antigen in HI assays.

Diagnostic utility of egg yolk for the detection of avian metapneumovirus antibodies in laying hens.

Surveillance and diagnosis of avian metapneumovirus (AMPV) infection typically involve measurement of serum antibodies. In the current study, eggs instead of serum samples were used for the detection of AMPV antibodies in egg-laying chicken hens by enzyme-linked immunosorbent assay (ELISA). AMPV-free commercial layer hens were experimentally challenged with AMPV strain SC1509 through intravenous or oculonasal administration. Antibody levels were determined by ELISA. AMPV antibodies were detected in egg yolks from challenged hens by 7 days postinoculation (dpi), with the peak titer at 16 dpi. Antibody levels in eggs laid at 28 dpi correlated well (r = 0.93) with sera taken 28 dpi from the same hens. In a field trial of the yolk ELISA, six broiler breeder farms were surveyed, and all tested positive for AMPV antibodies in hen eggs, although positivity varied from farm to farm. Abnormal discolored eggs collected from outbreak farms had significantly higher titers of AMPV yolk antibodies than normal eggs from the same farm, unlike clinically healthy farms, where normal and abnormal eggs had similar antibody titers. These results indicate that diagnosis of AMPV infection by yolk ELISA to detect anti-AMPV antibodies may be a suitable alternative to serologic testing.

Pathogenicity and antigenicity of a new variant of Korean nephropathogenic infectious bronchitis virus.

Despite the existence of an active vaccination program, recently emerged strains of nephropathogenic infectious bronchitis virus (IBV) in Korea have caused significant economic losses in the poultry industry. In this study, we assessed the pathogenic and antigenic characteristics of a K-IIb type field strain of IBV that emerged in Korea since 2003, such as Kr/Q43/06. Specific pathogen free 1-week-old chickens exhibited severe respiratory symptoms (dyspnea) and nephropathogenic lesions (swollen kidneys with nephritis and urate deposits) following challenge with the recent IBV field strain. The antigenic relatedness (R value), based on a calculated virus neutralization index, of the K-IIb type field strain and K-IIa type strain KM91 (isolated in 1991) was 30%, which indicated that the recent strain, Kr/Q43/06, is a new variant that is antigenically distinct from strain KM91. This report is the first to document the emergence of a new antigenic variant of nephropathogenic IBV in chicken from Korea.