Bacterial AB5 toxins are proteins, produced by pathogenic bacteria including Vibrio cholerae, Shigella dysenteriae, and enterohaemorrhagic Escherichia coli, which are usually released into the extracellular medium and cause disease by killing or altering the metabolism of target eukaryotic cells. The toxins are usually composed of one A subunit (a toxic domain) and five B subunits (a receptor-binding domain). This article overviews the characteristics and mode of actions of AB5 toxins including cholera toxin, Shiga-like toxin, and subtilase cytotoxin, and highlights current topics related to the roles of the effectors in promoting bacterial infection.
This is a retrospective study of 187 cases which visited our hospital from 2005 to 2014 and were clinically diagnosed as oral lichen planus. The subjects consisted of 61 males and 126 females (M:F sex ratio, 1:2), with a mean age of 66.7 years. As gross types, there were 66 lesions of atrophy predominance, 61 lesions of reticular form predominance and 60 lesions of erosion predominance. In total, incisional biopsies were performed in 67 of the 187 cases (35.8%). There were 42 cases (62.7%) which were pathologically diagnosed to be oral lichen planus, while 25 cases (37.3%) were diagnosed as other lesions including squamous cell carcinoma (4 cases), oral epithelial dysplasia (2 cases), pemphigus vulgaris (1 case) and pemphigoid (1 case). These clinically distinctive eight cases were wholly shown to be the gross type of erosion predominance. It is noteworthy that an early pathological examination is important for clinically diagnosing cases as oral lichen planus, especially in the gross type of erosion predominance.
It is common that patients after surgery for oral cancer have the loss of the tissue in the oral cavity and develop swallowing and articulation disorders. There have been many reports of treatment using a palatal augmentation prosthesis (PAP); however, there are only a few reports on the use of an artificial tongue in addition to a PAP. We reported our experience of two cases who used an artificial tongue in addition to a PAP. The swallowing function was tested using 10 ml of yogurt-like material. The swallowing time and intraoral residual quantity after swallowing were measured under four conditions: with/without PAP and artificial tongue. The speech function was tested with the Japanese syllable intelligibility test. Case 1: A 72-year-old man diagnosed as tongue cancer, treated with partial glossectomy and resection of the floor of the mouth with radial forearm flap reconstruction. Case 2: A 76-year-old man diagnosed as floor of the mouth cancer, treated with partial glossectomy and resection of the floor of the mouth with radial forearm flap reconstruction. In both cases, when wearing the PAP and artificial tongue, the swallowing time was shortened, the amount of oral residue decreased, and the total correct answer rate of the Japanese syllable intelligibility test was improved. It is suggested that wearing the artificial tongue is effective for cases with obvious recess of the floor of the mouth.