Lucia Balos

Correlation of Endothelin-1 and Transforming Growth Factor β1 with Malignancy and Vascularity in Human Gliomas

Because the prominent neovascularization characteristic of high grade primary brain tumors is composed mostly of vascular smooth muscle cells (VSMC), we studied the expression of the potent smooth muscle mitogen endothelin-1 (ET-1) and one of its secretagogues, transforming growth factor β1 (TGF-β1) in a series of astrocytic tumors. TGF-β1 is also of interest due to its known activity as an angiogenic factor. Using immunohistochemical methods, we examined 30 surgical cases: 10 glioblastoma multiforme, 10 anaplastic astrocytomas, and 10 low-grade astrocytomas. Using a monoclonal antibody to TGF-β1 and a polyclonal antibody to ET-1, we detected both growth factors in all cases of glioblastoma examined. In cases of anaplastic astrocytoma, 4 tumors were positive for both factors; 2 contained only ET-1; 2 contained only TGF-β1; and 2 exhibited no tumor cell immunoreactivity for either factor. In low-grade astrocytoma, 4 of 10 tumors showed weak ET-1 immunoreactivity; 2 of those contained TGF-β1 immunopositive tumor astrocytes; 6 tumors were negative for both factors. In all tumors that expressed both factors, serial sections showed that regions of ET-1 immunopositivity also tended to be positive for TGF-β1. Endothelial cells within all tumors were positive for ET-1. ET-1 and TGF-β1 are present in human astrocytomas and their expression correlates with tumor vascularity and malignancy. These results suggest roles for both ET-1 and TGF-β1 in the growth and progressive angiogenesis of the human glioma.

Toluene optic neurotoxicity: magnetic resonance imaging and pathologic features.

Toluene, a colorless liquid found in glues, paints, and industrial products, is lipid soluble and rapidly absorbed by the lipid-rich central nervous system. Prolonged exposure through occupation or purposeful inhalation may lead to neurologic abnormalities. Two men presented with multifocal central nervous system defects and bilateral optic neuropathy of unclear etiology. After numerous diagnostic tests, including brain magnetic resonance imaging, lumbar puncture, hematologic studies, and in one patient a brain biopsy, chronic inhalation of toluene was found to be the cause. Timely diagnosis is important because patients may experience improvement in neurologic and ocular manifestations with cessation of exposure, whereas continued inhalant abuse or exposure can result in permanent loss of neurologic function.

Combing the globe for terrorism.

A n 83-year-old man with Type 2 diabetes mellitus, systemic hypertension, atrial fibrillation, and successfully treated prostate carcinoma (6 years prior to presentation) complained of progressive painful loss of vision in his left eye for 2 weeks. Examination revealed visual acuity of 20/20 in the right eye and no light perception in the left eye. The left pupil was amaurotic, and there was mild left conjunctival injection and chemosis (Fig. 1), 1 mm of left proptosis, full extraocular movements, and no evidence of anterior or posterior uveitis. The right fundus was normal and left was consistent with combined central retinal artery occlusion (CRAO) and central retinal vein occlusion (CRVO) with optic nerve swelling (Fig. 2). The patient denied temple, jaw, and ear pain, scalp tenderness, migratory arthralgias, and fever. The superficial temporal arteries were palpable and nontender. MRI of the brain and orbits was performed.

Immunohistochemical Studies of Cell Cycle-associated Proteins in a Case of Giant Cell Granuloma of Mandible

Central Giant Cell Granuloma (CGCG) is a localized benign osteolytic lesion with variably aggressive nature. Due to the rarity of this disease, only a few studies with a limited number of cases have been reported, the results of which are controversial. Hence, there is not much data on the possible mechanisms underlying its aggressive biological behavior. In our study, immunohistochemistry was performed on a 50-year old female diagnosed with a giant cell granuloma of the mandible. We attempted to examine the expression profile and cellular distribution of cell cycle-associated proteins: cyclin D1, p53, PCNA, MIB-1 and facor XIIIa. Our results demonstrated that high-level expression of cyclin D1 was predominant in the nuclei of 85% of giant cells whereas cyclin D1 staining was noticed in only 20% of mononuclear cells. Expression of PCNA and MIB-1, on the other hand, was observed in 70% and 40% of mononuclear cells respectively, with less than 10% positive staining present in the giant cells. P53 protein did not appear to be overexpressed in either mononuclear or giant cells, and factor XIIIa was detected only in isolated stromal fibroblasts. These results support the hypothesis that over-expression of cyclin D1 in giant cells may play a role in the pathogenesis of CGCG, and the differential expression pattern of cyclin D1 and PCNA may be involved in the formation of multinucleated giant cells. [N A J Med Sci. 2009;2(2):48-50.]