Kingella kingae RtxA toxin interacts with sialylated gangliosides.

The membrane-damaging RTX family cytotoxin RtxA is a key virulence factor of the emerging pediatric pathogen Kingella kingae, but little is known about the mechanism of RtxA binding to host cells. While we have previously shown that RtxA binds cell surface glycoproteins, here we demonstrate that the toxin also binds different types of gangliosides. The recognition of gangliosides by RtxA depended on sialic acid side groups of ganglioside glycans.

Filamentous Hemagglutinin of Does Not Interact with the β Integrin CD11b/CD18.

The pertussis agent produces a number of virulence factors, of which the filamentous hemagglutinin (FhaB) plays a role in adhesion to epithelial and phagocytic cells. Moreover, FhaB was recently found to play a crucial role in nasal cavity infection and transmission to new hosts. The 367 kDa FhaB protein translocates through an FhaC pore to the outer bacterial surface and is eventually processed to a ~220 kDa N-terminal FHA fragment by the SphB1 protease.

RtxA Cytotoxin in the Context of Other RTX Toxins.

The Gram-negative bacterium is part of the commensal oropharyngeal flora of young children. As detection methods have improved, has been increasingly recognized as an emerging invasive pathogen that frequently causes skeletal system infections, bacteremia, and severe forms of infective endocarditis. secretes an RtxA cytotoxin, which is involved in the development of clinical infection and belongs to an ever-growing family of cytolytic RTX (Repeats in ToXin) toxins secreted by Gram-negative pathogens.

Adenylate Cyclase Toxin Elicits Airway Mucin Secretion through Activation of the cAMP Response Element Binding Protein.

The mucus layer protects airway epithelia from damage by noxious agents. Intriguingly, bacteria provoke massive mucus production by nasopharyngeal epithelia during the initial coryza-like catarrhal stage of human pertussis and the pathogen transmits in mucus-containing aerosol droplets expelled by sneezing and post-nasal drip-triggered cough. We investigated the role of the cAMP-elevating adenylate cyclase (CyaA) and pertussis (PT) toxins in the upregulation of mucin production in infected airway epithelia.

Glottic Malignant Fibrous Histiocytoma: A Case Report and Literature Review.

Pleomorphic sarcoma of the larynx is a rare variant of laryngeal cancer. We present the case of a 59-year-old male patient who has been smoking for 40 years. He presented with signs and symptoms of an obstructive glottic mass.

An unusual presentation of pleomorphic adenoma in a patient with thalassemia: A case report.

We report the first case of spontaneous infarction occurring in pleomorphic adenoma located in infratemporal fossa mimicking parapharyngeal abscess, including clinical presentation, workups, and surgical approach. The final diagnosis was confirmed on a histological basis. The combination of CT scan and MRI might be helpful in distinguishing neoplasia from abscess collection in this area.

Binding of RtxA Toxin Depends on Cell Surface Oligosaccharides, but Not on β Integrins.

The Gram-negative coccobacillus is increasingly recognized as an important invasive pediatric pathogen that causes mostly bacteremia and skeletal system infections. secretes an RtxA toxin that belongs to a broad family of the RTX (Repeats in ToXin) cytotoxins produced by bacterial pathogens. Recently, we demonstrated that membrane cholesterol facilitates interaction of RtxA with target cells, but other cell surface structures potentially involved in toxin binding to cells remain unknown.

Distinct Spatiotemporal Distribution of Bacterial Toxin-Produced Cellular cAMP Differentially Inhibits Opsonophagocytic Signaling.

Myeloid phagocytes have evolved to rapidly recognize invading pathogens and clear them through opsonophagocytic killing. The adenylate cyclase toxin (CyaA) of and the edema toxin (ET) of are both calmodulin-activated toxins with adenylyl cyclase activity that invade host cells and massively increase the cellular concentrations of a key second messenger molecule, 3',5'-cyclic adenosine monophosphate (cAMP). However, the two toxins differ in the kinetics and mode of cell entry and generate different cAMP concentration gradients within the cell.

Ectopic Intratracheal Thyroid: A Rare Cause of Airway Obstruction.

Ectopic intratracheal thyroid tissue (EITT) is a rare abnormality with only limited cases reported so far. The presenting symptoms can be very similar to those of bronchial asthma. We discuss the case of a 29-year-old man with subglottic ectopic thyroid, with a history of thyroid surgery for goiter, which has been managed with laser-assisted endoscopic approach.

Undiagnosed Hepatocellular Carcinoma Presenting as Nasal Metastases.

Hepatocellular carcinoma (HCC) is a primary malignancy of the liver with up to half of cases suffering from extrahepatic metastasis in the later stages of the disease. Commonly reported and encountered metastatic sites include the lymph nodes, lung, bone, and adrenal glands. This is an effort to throw a spotlight on a rare case of metastatic HCC which presented to us as two distinct lesions in the nose.

Effects of Oxidized Tallow on the Rabbit Serum Lipids and Antioxidant Activity of the In-vitro Lipids.

This paper describes the effects of thermally oxidized tallow on the serum lipids profile and radical scavenging activity (RSA) of the lipids extracted from the different tissues of the rabbits. Tallow was thermally oxidized at 130℃ for 9, 18, 27, 36 and 45 h respectively. Thermally oxidized tallow was fed to the local strain of Himalayan rabbits for one week.