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Ann Biser-Rohrbaugh

Publications and source records attributed to Ann Biser-Rohrbaugh.

2 recordsLinked to original sources

Brainstem gliomas.

INTRODUCTION: Brainstem gliomas have historically been one of the most difficult pediatric cancers to treat. Tumors arising in the brainstem were once uniformly discounted as surgically unresectable lesions. Early neurosurgeons thought this location to be inoperable and fraught with disaster. The advent of computed tomography (CT), magnetic resonance imaging (MRI), and sophisticated neurophysiological monitoring techniques have significantly advanced the surgical treatment of these precarious lesions. REVIEW: Brainstem gliomas are now recognized as a heterogenous group of tumors. They have been broadly classified into several categories depending upon the classification scheme. All these classification systems provide a framework to predict growth patterns, surgical resectability, and overall prognosis of these tumors. These systems allow the surgeon to obtain a better understanding of the distinction between low-grade tumors and diffuse inoperable tumor types. The authors review the current literature and management of brainstem tumors.

Brain Stem↗

Toxicity of intracranial and intraperitoneal O6-benzyl guanine in combination with BCNU delivered locally in a mouse model.

PURPOSE: The DNA-repair protein, O6-alkylguanine-DNA alkyl transferase, may account for resistance of CNS tumors to DNA-alkylating drugs, such as bis-(2-chloroethyl)-1-nitrosourea (BCNU). The therapeutic effects of BCNU can be potentiated by inhibiting the repair protein with an alkylated guanine analog, O6-benzyl guanine (O6BG). To investigate potential toxicity of this inhibition, we examined the effects of O6BG in mice treated with intracranial (i.c.) BCNU given via a biodegradable polymer. METHODS: Mice were treated with escalating doses of BCNU chronically delivered i.c., and with chronically delivered O6BG. The O6BG was delivered via a 7-day intraperitoneal (i.p.) or i.c. osmotic minipump. Toxicity of the combination therapies was measured from survival data. Bone marrow response was estimated from white blood cell counts. RESULTS: Combining systemic (i.p.) O6BG with locally (i.c.) delivered BCNU resulted in a decrease in the maximum tolerated dose (MTD) of local BCNU. With local delivery of O6BG, the MTD of BCNU in combination with O6BG was increased. CONCLUSIONS: Based on the results of this study, a dose escalation study will be necessary when combining systemic O6BG with the higher doses of i.c. BCNU.

Animals↗