Liposarcoma of the tongue: case report and literature update

Liposarcoma is an exceedingly rare tumor in the oral cavity. We report a case of a 70-year-old man with liposarcoma that presented as a lump on the tongue. The excised tumor was diagnosed as a well-differentiated lipoma-like liposarcoma. The majority of cases of well-differentiated liposarcoma follow a relatively benign course, but the disease has a high recurrence rate. It appears that accurate clinical and histopathologic diagnosis of this lesion is difficult. The prognosis seems to depend on the histologic type, size, and location of the lesion. Wide surgical excision is important for successful management of these liposarcomas.

Necrosis of the tongue after transient ischemic attack

We report an unusual case of necrosis of the tongue after transient ischemic attack in a 67-year-old man. Angiography revealed occlusion of the right external carotid artery at the bifurcation of the common carotid artery. Debridement of the wound and removal of the necrotic tissue resulted in good healing.

The alteration of penicillin-binding proteins (PBPs) in drug-resistant Streptococcus pneumoniae isolated from acute otitis media

Streptococcus pneumoniae is the micro-organism most frequently isolated from acute otitis media (AOM). Recently, drug-resistant or insensitive strains have been prevalent among pneumococcal AOM cases and were reportedly associated with persistent or recurrent otitis media. The purpose of this study was to examine the alterations of penicillin-binding proteins (PBPs) in Streptococcus pneumoniae isolated from AOM. The PBP samples from 21 clinically isolated strains were examined by 14C-penicillin binding assay and also by adding CCL and CDTR as competitors of 14C-penicillin. Reduced signals in PBP1A and PBP2X/2A were typically observed with the penicillin-resistant Streptococcus pneumoniae samples, while widely different PBP profiles were obtained in each strain of penicillin-insensitive Streptococcus pneumoniae. The competitive binding assay with penicillin-insensitive strains revealed the reduced affinity of CCL to PBPs in comparison with that of CDTR. The results of the penicillin-binding assay were consistent with the results from minimal inhibitory concentration analysis, and its potential usefulness for the prediction of drug resistance was demonstrated.

Immunohistochemical localization of manganese superoxide dismutase in rat vestibular dark cell regions

A modified immunoglobulin peroxidase bridge sequence method was used to detect the localization of manganese superoxide dismutase (MnSOD), a superoxide radical (O2-) scavenging enzyme locating in mitochondrial matrix, in the vestibular labyrinth of pigmented rats. Strong positive MnSOD immunostaining was demonstrated in the dark cell regions of the ampullae, utricle, and common crus. The result provides for the first time direct evidence demonstrating the existence of mitochondrial O2- scavengers in the vestibular labyrinth and illustrates that the specific sites for vestibular MnSOD immunolocalization are the dark cell regions. This site specificity of MnSOD immunolocalization suggests that dark cell regions may possess high metabolic activity and may encounter constant threat from O2-. We assume MnSOD is needed in protecting some physiologic functions of the dark cell regions. Cell types showing negative MnSOD immunostaining may conceivably be relatively vulnerable to acute O2- damage.

Superficial siderosis of the central nervous system: a case with an unruptured intracranial aneurysm

We present a case of superficial siderosis (SS) of the central nervous system (CNS) with an unruptured intracranial aneurysm to illustrate that the commonly encountered unexplainable progressive sensorineural hearing loss (SNHL) can be an important sign for the early awareness of this rare disorder. The literature on SS is reviewed and the pathogenesis of SS is discussed.