A 14-year-old girl presented with seizures. Radiological examinations revealed an arachnoid cyst in left middle fossa and a cystic mass in the interpeduncular cistern. The cyst was opened and the wall of the cyst and a mass were biopsied. The histological findings were characteristic of an arachnoid cyst and hamartoma, respectively. A hypothalamic hamartoma associated with an arachnoid cyst is comparatively rare; however, such a case may help clarify the genesis of this malformation.
Cerebral cavernous malformations (CCMs) are congenital abnormalities of the cerebral vessels. The de novo development of new lesions in this disease has been reported. However, the underlying mechanism of progressive CCMs in such patients remains unclear. This report documents two cases of multiple probable CCMs that showed a progressive behaviour. The plasma levels of vascular endothelial growth factor (VEGF), and transforming growth factor-beta1 (TGF-beta1) were measured using an enzyme-linked immunosorbent assay (ELISA). The concentration of both VEGF and TGF-beta1 in plasma was increased in these patients. A relationship was observed between high concentrations of growth factors and progressive CCMs. Even though a causal linkage between these conditions cannot be confirmed, a continuous high VEGF level in plasma could be a possible clinical indicator for subsequent intracerebral haemorrhages in the CCM patients.
Our previous study demonstrated that mutant IkappaBalpha (IkappaBalphaM) could inhibit glioma angiogenesis and tumorigenesis through the downregulation of vascular endothelial growth factor (VEGF) and IL-8. However, the pathways involved in VEGF expression are not well understood. Growing evidence indicates that hypoxia-inducible factor-1alpha (HIF-1alpha) and cyclooxygenases-2 (COX-2) play important roles in this progression. In this study, we first examined the expressions of hypoxia-induced genes in human glioma cells transfected with IkappaBalphaM (IN500deltaM) or control plasmid (IN500delta) in vitro. We found that hypoxic stress induced the expressions of HIF-1alpha, COX-2, and VEGF, and that IkappaBalphaM completely suppressed these expressions in vitro. Next, we injected these glioma cells into nude mice. After 3 weeks, the mice were moved to a hypoxic chamber (10% oxygen) for 3, 12, 24, 48, 96, or 144 h. The expressions of HIF-1alpha, COX-2, and VEGF in vivo were then analyzed by Northern blot and immunohistochemistry. IkappaBalphaM suppressed the expression of hypoxia-induced HIF-1alpha gene in vivo, but hypoxic stress induced the expression of COX-2 after 72 h. VEGF induction followed after 96 h of hypoxia in IN500deltaM cells. These findings suggest that VEGF expression appears to be regulated through dual interdependent mechanisms involving HIF-1 and COX-2 genes, and IkappaBalphaM could inhibit VEGF expression through these two pathways. Thus, IkappaBalphaM is identified as a pivotal factor in angiogenesis and is a potential target for neoplasm therapy.
Abstract-The effects of bifemelane hydrochloride (BF) upon various cholinergic markers, muscarinic receptors, acetylcholinesterase (AChE) and choline acetyl transferase (CAT), in the aged rat brain were examined. Marked reduction of the density of muscarinic receptors (BmaX) as well as AChE and CAT activity con comitant with aging was observed. Administration of BF in daily doses of 10 mg/ kg for 4 weeks to aged rats significantly decreased the apparent dissociation constant (Ku) for QNB in muscarinic receptors in the forebrain, but did not affect the value of Bmax. CAT activity also increased significantly compared with that of control aged rats, but administration of BF did not alter AChE activity. These results indicate that long-term treatment with BF enhances the affinity of muscarinic receptors for QNB as well as CAT activity and that BF may have therapeutic application in the treatment of CNS cholinergic dysfunctions.
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