Dennis R. Groothuis

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Drug delivery to brain tumors has been a controversial subject. Some believe the blood-brain barrier is not important, while others believe it is the major obstacle in treatment and have devised innovative approaches to circumvent it. These approaches can be divided into two categories: those that attempt to increase drug delivery of intravascularly(More)
The ability of antiviral and antiretroviral drugs to enter the brain is a critical issue in the treatment of many viral brain diseases, including HIV-related neurologic disease. Much of the literature concerning nucleoside analog entry into the nervous system focuses on drug levels in the cerebrospinal fluid (CSF), equating these with drug levels in the(More)
We studied microvessel organization in five brain tumor models (ENU, MSV, RG-2, S635cl15, and D-54MG) and normal brain, including microvessel diameter (LMVD), intermicrovessel distance (IMVD), microvessel density (MVD), surface area (S(v)), and orientation. LMVD and IMVD were larger and MVD was lower in tumors than normal brain. S(v) in tumors overlapped(More)
We have previously demonstrated that receptors for hematopoietic growth factors, stem cell factor (SCF) and granulocyte-colony stimulating factor (G-CSF) are expressed in the neurons and the neural progenitor cells (NPCs) of the adult rat brain, and that systemic administration of SCF and G-CSF in the first week after induction of cortical brain ischemia (3(More)
A total of 72 RG-2 transplanted gliomas were studied in 58 rats at three time points (1, 30, 240 min) after intravenous injection of [125I]radioiodinated serum albumin ([125I]RISA). The animals were divided into two groups: a control group that received no treatment and a second group that was treated with five doses of 1.5 mg/kg of dexamethasone over 2.5(More)
Regional measurements of blood flow (F) were performed in transplanted intracerebral RG-2 rat gliomas using [14C]iodoantipyrine, Kety-Schmidt blood flow equations, and quantitative autoradiography. Twenty-nine intracranial tumors in ten rats were analyzed by location; 18 intraparenchymal, seven meningeal, two third-ventricular, and two fourth-ventricular(More)
Regional blood-to-tissue transport of 14C-alpha-aminoisobutyric acid (AIB) was measured in avian sarcoma virus (ASV)-induced rat brain tumors and expressed as a unidirectional transfer rate constant (K). The magnitude of K was variable and did not correlate with histologic classification or specific features of the tumors, with the possible exception of(More)
We evaluated the delivery of 14C-cytosine arabinoside (AraC) to rat brain by: 1) intravenous (IV) bolus, by 2) intrathecal (IT) and 3) intraventricular (IVT) infusion, and by 4) convection-enhanced delivery (CED) into the caudate nucleus. Plasma and brain AraC metabolites were measured with HPLC, and distribution and concentration of 14C-AraC in brain(More)
Regional measurements of blood-to-tissue transport were performed in transplanted RG-2 rat gliomas using [alpha- 14C]aminoisobutyric acid (AIB), quantitative autoradiography, and equations to express a unidirectional transfer constant. Thirty-eight intracranial tumors in ten rats were analyzed according to location; 23 intraparenchymal tumors, eight(More)
A cooperative study was conducted by the International Working Group on Mycobacterial Taxonomy to correlate the agglutination serovar designations of Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceum strains with the species ascriptions of these organisms according to molecular criteria and cultural properties and to assess(More)