Treatment resistance, a major contributing factor to the dismal prognosis for patients with HGGs, is the result of multiple mechanisms that include, among others, inactivation of drugs, molecular mechanisms of resistance to DNA damage and apoptosis, and attenuation of cytotoxicity imposed by the microenvironment (e.g. hypoxia). Add to these mechanisms the limitations to delivery of therapy imposed by the diffusely invasive growth pattern of HGG tumor cells into brain regions with an intact BBB, and one can begin to understand the daunting problem of designing effective therapies. Through aggressive cytoreduction, the neurosurgeon helps to eliminate a large portion of hypoxic tissue, but the precise impact of cytore-duction on reducing resistance and improving efficacy in adjuvant treatment of residual disease is not known. Targeting one specific mechanism of resistance is unlikely to confer an appreciable improvement in tumor response and the neurosurgeon is likely to be called upon in the future to assist in delivering novel therapies aimed at overcoming multiple mechanisms of treatment resistance.
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The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.