Analysis of DNA damage induced by nitrosourea derivatives in rat brain tumor cells using a sequencing procedure

DNA damages caused by various anticancer nitrosourea compounds such as ACNU and MCNU were studied. Reiterated fragments of 167 and 203 base pairs (bp) were obtained after Hind III and Hae III restriction endonuclease digestion of 9L rat brain tumor DNA. The end-labeled reiterated fragments were reacted with ACNU and MCNU, which resulted in the scission breaks corresponding to the locations of guanine on an extended Maxam-Gilbert sequencing gel. Subsequent piperidine hydrolysis yielded scission products more frequently. These results indicate that nitrosoureas such as ACNU and MCNU generate DNA scission breaks and/or alkali-labile sites preferentially at the position of guanine moieties in rat brain tumor DNA.     

In vitro damage of isolated DNA from two brain tumor cell lines induced by a water-soluble antitumor nitrosourea

We report the DNA sites damaged by the antitumor drug, nimustine hydrochloride (ACNU), in highly reiterated DNA sequences of rat glioma cells. A reiterated fragment of 370 base pairs (bp), obtained after Hind III restriction endonuclease digestion of rat glioma C6 or 9L cells DNA, was divided into 167 and 203 bp by subsequent Hae III enzyme reaction. The reaction of end-labelled 167 and 203 bp fragments with ACNU resulted in scission breaks corresponding to the locations of guanine. Moreover, ACNU and subsequent piperidine hydrolysis produced more frequent breaks of the phosphodiester bonds at the guanine positions, thus forming alkali-labile sites. These results indicate that the preferred site of DNA strand scission induced by ACNU is at guanine positions.     

Intracranial invasion of scalp carcinoma

Summary Among 10 patients with squamous cell carcinoma admitted to our hospital, 5 showed intracranial invasion and 4 died with regrowth of intracranial tumour 9 to 24 months after incomplete extirpation of tumour. We reviewed our experience in the management of advaned scalp carcinoma, from neurosurgical and neuroradiological points of view. Durai invasion failed to be removed completely because of involvement of the middle part of the superior sagittal sinus. Therefore, total resection, facilitated by early detection prior to intracranial invasion, is mandatory for successful treatment of these scalp carcinomas.     

Multiple fungal aneurysms: report of a rare case implicating steroid as predisposing factor

A 61-year-old man with a ruptured aneurysm of the anterior communicating artery developed hemorrhagic cerebral infarction 22 days after an operation associated with occlusion of the right angular artery. Angiograms further revealed sequential changes of intracranial vessels including progressive obstructions of the right anterior and middle cerebral arteries and four aneurysms on the left pericallosal artery. Subsequently, the patient became comatose and died. At autopsy the newly formed aneurysms originating from the left pericallosal artery were of fungal (Phycomycetes) origin and numerous nonseptate, branching hyphae were also seen in the obstructed cerebral arteries. Intracranial fungal aneurysms are reviewed in the literature and the pathogenesis in the present case is discussed.