Genome-wide Analysis of Chlamydophila pneumoniae Gene Expression at the Late Stage of Infection

Chlamydophila pneumoniae, an obligate intracellular eubacterium, changes its form from a vegetative reticulate body into an infectious elementary body during the late stage of its infection cycle. Comprehension of the molecular events in the morphological change is important to understand the switching mechanism between acute and chronic infection, which is deemed to relate to the pathogenesis of atherosclerosis. Herein, we have attempted to screen genes expressed in the late stage with a genome-wide DNA microarray, resulting in nomination of 17 genes as the late-stage genes. Fourteen of the 17 genes and six other genes predicted as late-stage genes were confirmed to be up-regulated in the late stage with a quantitative reverse transcriptase–polymerase chain reaction. These 20 late-stage genes were classified into two groups by clustering analysis: ‘drastically induced’ and ‘moderately induced’ genes. Out of eight drastically induced genes, four contain σ28 promoter-like sequences and the other four contain an upstream common sequence. It suggests that besides σ28, there are certain up-regulatory mechanisms at the late stage, which may be involved in the chlamydial morphological change and thus pathogenesis

Radiation-induced angiosarcoma of the brain

Primary angiosarcoma of the central nervous systemis unusual.We encountered a case of radiation-induced angiosarcoma of the brain. A 65-year-old male was referred to our hospital with drowsiness for the last 6 months. He had undergone radiation therapy for pituitary adenoma 43 years ago. An MRI revealed a right temporal lobe tumour that consisted of a well-demarcated haemorrhagic lesion and an avid contrast enhancement, with significant vasogenic oedema. Surgical resection was performed and a post-operative pathological diagnosis of an angiosarcoma was made. A Thorotrast-associated angiosarcoma has been, hitherto, the only reported case of radiation-induced angiosarcoma of the brain. We present an extremely rare case of primary angiosarcoma of the brain, occurring after external beam radiotherapy