Expression of hypoxia-related tissue factors in astrocytic gliomas. A multivariate survival study with emphasis upon carbonic anhydrase IX.

Carbonic anhydrase IX (CAIX) is a transmembrane enzyme involved in the reversible metabolism of carbon dioxide to carbonic acid and, hence, in physiological pH regulation. It also participates in cellular differentiation and proliferation, its expression being absent in most normal tissues. It has been recently postulated that the hypoxia-inducible factor (HIF-1) pathway up-regulated by hypoxia accounts for CAIX overexpression in most human tumors. In the present study, we examined the expression of this enzyme in diffuse gliomas of astrocytic origin in relation to vascular endothelial growth factor (VEGF) and HIF-1alpha expression, proliferation rate (as assessed with Ki-67 antigen), microvessel morphology, and survival. Of 84 cases analyzed, 61 cases (72.6%) displayed strong membrane and/or cytoplasmic expression of CAIX and were grouped as positive. Immunoreactivity tended to have a perinecrotic distribution and increased in parallel with the extent of necrosis (P < .001) and histologic grade (P < .001). A positive correlation was also noted with HIF-1alpha and VEGF expression (P < .001), proliferation rate (P = .010), microvessel density (P = .004), and microvessel caliber parameters (P = .014-.038). In univariate survival analysis, increased CAIX expression was associated with shortened survival in the entire cohort (P < .0001), along with VEGF (P = .0205) and HIF-1alpha levels (P = .0190). Multivariate analysis selected the interaction model of CAIX, with grade and age as the only parameters independently affecting survival. CAIX expression was also the only significant parameter for the survival of patients with grades II/III. We conclude that CAIX may be used as a prognostic indicator in diffuse astrocytomas to refine the information provided by grade. Given the role of CAIX in the acidification of tumor environment and its up-regulation by hypoxia, it is thought that CAIX expression may be linked to resistance of tumor cells to radiotherapy by allowing them to acclimatize to a hypoxic and acidic microenvironment.

Cerebral abscess of odontogenic origin.

INTRODUCTION: Cerebral abscess is a rare but serious and life-threatening infection. Dental infections have occasionally been reported as the source of bacteria for such an abcess. PATIENT AND METHODS: A 54-year-old man was admitted with a right hemiparesis and epileptic fits. After clinical, laboratory and imaging examination, the diagnosis of a cerebral abscess of the left parietal lobe was made. The intraoral clinical examination as well as a panoramic radiograph confirmed the presence of generalized periodontal disease, multiple dental caries, and periapical pathology. The treatment included: (i) Immediate administration of high-dose intravenous antibiotics and (ii) surgical procedures consisting of craniotomy and resection of the abscess cavity first, and secondly removal of the periodontal, decayed and periapically involved teeth of the patient, in an effort to eradicate all the possible septic foci, presuming the cerebral abscess to be of odontogenic infection. RESULTS: The patient made an uneventful recovery, and 29 months postoperatively he had completely recovered from the hemiparesis.