The deposition of Hg203-chlormerodrin in experimental brain tumors

1971 ◽  
Vol 35 (3) ◽  
pp. 303-308 ◽  
Author(s):  
Tatsuya Kobayashi ◽  
Louis Bakay ◽  
Joseph C. Lee
Keyword(s):  
Brain Tumors ◽  
Tumor Cells ◽  
Normal Brain ◽  
Intracranial Tumors ◽  
Electron Microscopic ◽  
Electron Microscopic Autoradiography ◽  
Content Type ◽  
Meningeal Tumors ◽  
Vacuolar System ◽  
Fine Print

✓ The deposition of Hg203-chlormerodrin was studied in intracranial tumors in mice induced by implantation of 20-methyl cholanthrene by tissue assay, as well as light microscopic and electron microscopic autoradiography. The investigations were carried out in astrocytomas, glioblastomas, and meningeal tumors. The chlormerodrin content of the tumors exceeded that of normal brain with a significant tumor/brain ratio ranging from 5.8 to 22.5. It was found that the chlormerodrin molecule becomes rapidly incorporated in the tumor cells, with a preference for that portion of the cytoplasm associated with the vacuolar system.

Thymidine kinase-mediated killing of rat brain tumors

1993 ◽  
Vol 79 (5) ◽  
pp. 729-735 ◽  
Author(s):  
David Barba ◽  
Joseph Hardin ◽  
Jasodhara Ray ◽  
Fred H. Gage
Keyword(s):  
Gene Therapy ◽  
Brain Tumors ◽  
Tumor Cells ◽  
Wild Type ◽  
Cns Disorders ◽  
Content Type ◽  
Potential Applications ◽  
Ganciclovir Treatment ◽  
The Brain ◽  
Fine Print

✓ Gene therapy has many potential applications in central nervous system (CNS) disorders, including the selective killing of tumor cells in the brain. A rat brain tumor model was used to test the herpes simplex virus (HSV)-thymidine kinase (TK) gene for its ability to selectively kill C6 and 9L tumor cells in the brain following systemic administration of the nucleoside analog ganciclovir. The HSV-TK gene was introduced in vitro into tumor cells (C6-TK and 9L-TK), then these modified tumor cells were evaluated for their sensitivity to cell killing by ganciclovir. In a dose-response assay, both C6-TK and 9L-TK cells were 100 times more sensitive to killing by ganciclovir (median lethal dose: C6-TK, 0.1 µg ganciclovir/ml; C6, 5.0 µg ganciclovir/ml) than unmodified wild-type tumor cells or cultured fibroblasts. In vivo studies confirmed the ability of intraperitoneal ganciclovir administration to kill established brain tumors in rats as quantified by both stereological assessment of brain tumor volumes and studies of animal survival over 90 days. Rats with brain tumors established by intracerebral injection of wild-type or HSV-TK modified tumor cells or by a combination of wild-type and HSV-TK-modified cells were studied with and without ganciclovir treatments. Stereological methods determined that ganciclovir treatment eliminated tumors composed of HSV-TK-modified cells while control tumors grew as expected (p < 0.001). In survival studies, all 10 rats with 9L-TK tumors treated with ganciclovir survived 90 days while all untreated rats died within 25 days. Curiously, tumors composed of combinations of 9L and 9L-TK cells could be eliminated by ganciclovir treatments even when only one-half of the tumor cells carried the HSV-TK gene. While not completely understood, this additional tumor cell killing appears to be both tumor selective and local in nature. It is concluded that HSV-TK gene therapy with ganciclovir treatment does selectively kill tumor cells in the brain and has many potential applications in CNS disorders, including the treatment of cancer.

Quantification and pharmacokinetics of blood-brain barrier disruption in humans

1996 ◽  
Vol 85 (6) ◽  
pp. 1056-1065 ◽  
Author(s):  
Bernhard Zünkeler ◽  
Richard E. Carson ◽  
Jeff Olson ◽  
Ronald G. Blasberg ◽  
Hetty Devroom ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Normal Brain ◽  
Content Type ◽  
Barrier Disruption ◽  
Blood Brain Barrier Disruption ◽  
Blood Brain ◽  
Brain Barrier Disruption ◽  
Fine Print

✓ Hyperosmolar blood-brain barrier disruption (HBBBD), produced by infusion of mannitol into the cerebral arteries, has been used in the treatment of brain tumors to increase drug delivery to tumor and adjacent brain. However, the efficacy of HBBBD in brain tumor therapy has been controversial. The goal of this study was to measure changes in vascular permeability after HBBBD in patients with malignant brain tumors. The permeability (K1) of tumor and normal brain blood vessels was measured using rubidium-82 and positron emission tomography before and repeatedly at 8- to 15-minute intervals after HBBBD. Eighteen studies were performed in 13 patients, eight with glioblastoma multiforme and five with anaplastic astrocytoma. The HBBBD increased K1 in all patients. Baseline K1 values were 2.1 ± 1.4 and 34.1 ± 22.1 µl/minute/ml (± standard deviation) for brain and tumor, respectively. The peak absolute increases in K1 following HBBBD were 20.8 ± 11.7 and 19.7 ± 10.7 µl/minute/ml for brain and tumor, corresponding to percentage increases of approximately 1000% in brain and approximately 60% in tumor. The halftimes for return of K1 to near baseline for brain and tumor were 8.1 ± 3.8 and 4.2 ± 1.2 minutes, respectively. Simulations of the effects of HBBBD made using a very simple model with intraarterial methotrexate, which is exemplary of drugs with low permeability, indicate that 1) total exposure of the brain and tumor to methotrexate, as measured by the methotrexate concentration-time integral (or area under the curve), would increase with decreasing infusion duration and would be enhanced by 130% to 200% and by 7% to 16%, respectively, compared to intraarterial infusion of methotrexate alone; and 2) exposure time at concentrations above 1 µM, the minimal concentration required for the effects of methotrexate, would not be enhanced in tumor and would be enhanced by only 10% in brain. Hyperosmolar blood-brain barrier disruption transiently increases delivery of water-soluble compounds to normal brain and brain tumors. Most of the enhancement of exposure results from trapping the drug within the blood-brain barrier, an effect of the very transient alteration of the blood-brain barrier by HBBBD. Delivery is most effective when a drug is administered within 5 to 10 minutes after disruption. However, the increased exposure and exposure time that occur with methotrexate, the permeability of which is among the lowest of the agents currently used clinically, are limited and the disproportionate increase in brain exposure, compared to tumor exposure, may alter the therapeutic index of many drugs.

Immunobiology of primary intracranial tumors

1981 ◽  
Vol 54 (3) ◽  
pp. 331-337 ◽  
Author(s):  
William H. Brooks ◽  
Robert B. Latta ◽  
M. Stephen Mahaley ◽  
Thomas L. Roszman ◽  
Lynn Dudka ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Linear Combination ◽  
Tumor Recurrence ◽  
Intracranial Tumors ◽  
Content Type ◽  
Sequential Analyses ◽  
Fine Print ◽  
Host Immunocompetence

✓ Long-term assessment of general host immunocompetence of patients with primary malignant brain tumors indicates that although isolated determinations of nonspecific responsiveness are not clinically useful, sequential analyses utilizing a linear combination of in vitro lymphocyte probes are capable of predicting tumor recurrence prior to clinical deterioration.

The long-term side effects of radiation therapy for benign brain tumors in adults

1990 ◽  
Vol 73 (4) ◽  
pp. 502-512 ◽  
Author(s):  
Ossama Al-Mefty ◽  
Jane E. Kersh ◽  
Anupam Routh ◽  
Robert R. Smith
Keyword(s):  
Radiation Therapy ◽  
Side Effects ◽  
Brain Tumors ◽  
Adult Patients ◽  
Intracranial Tumors ◽  
Content Type ◽  
Pituitary Dysfunction ◽  
Fine Print

✓ Radiation therapy plays an integral part in managing intracranial tumors. While the risk:benefit ratio is considered acceptable for treating malignant tumors, risks of long-term complications of radiotherapy need thorough assessment in adults treated for benign tumors. Many previously reported delayed complications of radiotherapy can be attributed to inappropriate treatment or to the sensitivity of a developing child's brain to radiation. Medical records, radiological studies, autopsy findings, and follow-up information were reviewed for 58 adult patients (31 men and 27 women) treated between 1958 and 1987 with radiotherapy for benign intracranial tumors. Patient ages at the time of irradiation ranged from 21 to 87 years (mean 47.7 years). The pathology included 46 pituitary adenomas, five meningiomas, four glomus jugulare tumors, two pineal area tumors, and one craniopharyngioma. Average radiation dosage was 4984 cGy (range 3100 to 7012 cGy), given in an average of 27.2 fractions (range 15 to 45 fractions), over a period averaging 46.6 days. The follow-up period ranged from 3 to 31 years (mean 8.1 years). Findings related to tumor recurrence or surgery were excluded. Twenty-two patients had complications considered to be delayed side effects of radiotherapy. Two patients had visual deterioration developing 3 and 6 years after treatment; six had pituitary dysfunction; and 17 had varying degrees of parenchymal changes of the brain, occurring mostly in the temporal lobes and relating to the frequent presentation of pituitary tumors (two of these also had pituitary dysfunction). One clival tumor, with the radiographic appearance of a meningioma, developed 30 years post-irradiation for acromegaly. This study unveils considerable delayed sequelae of radiotherapy in a series of adult patients receiving what is considered “safe” treatment for benign brain tumors.

Biological significance of tissue plasminogen activator content in brain tumors

1991 ◽  
Vol 74 (3) ◽  
pp. 480-486 ◽  
Author(s):  
Raymond Sawaya ◽  
O. Juhani Rämö ◽  
Mei Lin Shi ◽  
George Mandybur
Keyword(s):  
Brain Tumors ◽  
Plasminogen Activator ◽  
Tumor Necrosis ◽  
Tumor Tissue ◽  
Biological Significance ◽  
Low Grade ◽  
Normal Brain ◽  
Content Type ◽  
Low Grade Gliomas ◽  
Fine Print

✓ Fresh brain-tumor samples were obtained at operation and analyzed for their content of tissue type plasminogen activator (tPA) using an activity assay (gel chromatography zymogram) and an enzyme-linked immunospecific assay. The specimens were taken from 23 glioblastomas, 35 metastatic tumors, 42 meningiomas, 16 low-grade gliomas, and seven acoustic neurinomas; seven specimens were from normal brain. A strong correlation was found between the results of the two assays (r = 0.77, p < 0.0001). There was a threefold difference in the tPA content of the benign tumors as compared to malignant tumors (p = 0.0006), the latter having less tPA. Histologically benign meningiomas contained higher tPA than malignant meningiomas (p = 0.01); however, the difference between low-grade gliomas and high-grade gliomas was less evident. Overall regression analysis data have shown an inverse relationship between the tissue content in tPA and the presence and degree of tumor necrosis and peritumoral brain edema (p = 0.004 and p = 0.0004, respectively). This finding was most consistent in the glioblastoma group where the correlation coefficient values were r = 0.53 and r = −0.55, respectively. There was no significant correlation between the tissue tPA content and the age and sex, steroid use, or plasma tPA of the patients or the duration of symptoms. In summary, this is the first demonstration of tPA in a large series of human brain tumors and in normal brain. The differences observed have clear biological significance and, although the source of tPA in tumor tissue is still unknown, a relative reduction in tPA in tumor tissue may play an integral role in the development of tissue necrosis and tissue edema. The lack of tPA in tumor necrosis was not due to tissue destruction and cell death since urokinase was readily detectable in that tissue.

Potent and specific killing of human malignant brain tumor cells by an anti-transferrin receptor antibody-ricin immunotoxin

1987 ◽  
Vol 66 (6) ◽  
pp. 850-861 ◽  
Author(s):  
John Zovickian ◽  
Virginia Gray Johnson ◽  
Richard J. Youle
Keyword(s):  
Tumor Cells ◽  
Transferrin Receptor ◽  
Solid Phase ◽  
Target Cells ◽  
Neoplastic Disease ◽  
Normal Brain ◽  
Plant Toxin ◽  
Content Type ◽  
Hybrid Molecules ◽  
Fine Print

✓ Immunotoxins are hybrid molecules which combine the exquisite selectivity of monoclonal antibodies with the potent toxicity of protein toxins. An immunotoxin was constructed by linking a murine monoclonal antibody against the human transferrin receptor (TR) to the plant toxin, ricin. The cytotoxic activity of the anti-TR-ricin immunotoxin was tested in vitro and demonstrated highly potent and cell type-specific killing of cells derived from human glioblastoma, medulloblastoma, and leukemia. The anti-TR-ricin immunotoxin killed more than 50% of “target” cells at a concentration of 5.6 × 10−13 M after an 18-hour incubation with the ionophore, monensin. This potency exceeds that of any other anti-TR immunotoxin reported in the literature. When the activity of the anti-TR-ricin immunotoxin against “target” tumor-derived cells was compared with the immunotoxin's activity against “non-target” cells, it could be predicted that a selective toxicity of anti-TR-ricin immunotoxin between tumor cells and normal brain was more than 150- to 1380-fold. Solid-phase indirect radioimmunoassay techniques were used to demonstrate significantly higher levels of TR in the glioblastoma- and medulloblastoma-derived cell lines, as well as in surgical tissue samples of medulloblastoma and glioblastoma, as compared to normal brain. Immunotoxins targeted to the TR may possess sufficient specificity to be of therapeutic importance, particularly to treat neoplastic disease of the central nervous system involving compartments (such as intrathecal, intraventricular, or cystic) where delivery of immunotoxins to tumor would not require transvascular transport.

Alpha-1-antitrypsin in human brain tumors

1987 ◽  
Vol 67 (2) ◽  
pp. 258-262 ◽  
Author(s):  
Raymond Sawaya ◽  
Mario Zuccarello ◽  
Robert Highsmith
Keyword(s):  
Brain Tumors ◽  
Human Brain ◽  
Tumor Cells ◽  
Fibrinogen Level ◽  
Sodium Dodecyl ◽  
Content Type ◽  
Human Brain Tumors ◽  
Preoperative Serum ◽  
Alpha 1 Antitrypsin ◽  
Fine Print

✓ This study was undertaken to confirm the presence of alpha-1-antitrypsin (α1-AT) in human brain tumors and to attempt to elucidate its significance. Seventy-seven consecutive unselected patients with various brain tumors were entered in this study. The α1-AT and α2-macroglobulin contents of the tumor extracts were qualitatively assessed by Ouchterlony immunodiffusion techniques. Plasminogen activator (PA) activity was assayed electrophoretically on sodium dodecyl sulfate gels. The patients were divided into two groups according to the positivity of their tumors to α1-AT. Sixty-eight percent of the tumors were positive for α1-AT, and all specimens were negative for α2-macroglobulin. Clinical and biological parameters obtained in all study patients failed to show statistically significant differences between the two groups with the exception of PA activity (p = 0.001), the peritumoral edema as seen on computerized tomography, and the preoperative serum fibrinogen level. These three parameters were higher in the group with specimens positive to α1-AT. This study supports the hypothesis that α1-AT is produced primarily by tumor cells in proportion to the regional proteolytic and inflammatory activity, and may protect the tumor cells.

Expression of vascular permeability factor in craniopharyngioma

1999 ◽  
Vol 91 (5) ◽  
pp. 831-834 ◽  
Author(s):  
Jesús Vaquero ◽  
Mercedes Zurita ◽  
Santiago de Oya ◽  
Santiago Coca ◽  
Carmen Morales ◽  
...  
Keyword(s):  
Vascular Permeability ◽  
Tumor Cells ◽  
Vascular Endothelial ◽  
Intracranial Tumors ◽  
Vascular Permeability Factor ◽  
Macroscopic Appearance ◽  
Content Type ◽  
Permeability Factor ◽  
High Degree ◽  
Fine Print

Object. The expression of vascular endothelial growth/permeability factor (VEG/PF) has recently been correlated with the presence of tumor-associated cysts in some intracranial tumors. The purpose of this study was to evaluate a possible relationship between the presence of VEG/PF and the formation of cysts in craniopharyngiomas.Methods. The expression of VEG/PF was studied in histological specimens from a series of 12 craniopharyngiomas. In this series, the tumors were classified as presenting a mainly solid pattern with small macroscopic cysts (four patients) or a mainly cystic pattern (eight patients). The mainly solid tumors containing small macroscopic cysts showed little or no VEG/PF positivity, which was mainly present in tumor cells surrounding cysts. Nevertheless, mainly cystic craniopharyngiomas showed a moderate or high degree of VEG/PF positivity in tumor cells.Conclusions. These findings indicate that the predominance of a cystic or solid macroscopic appearance of craniopharyngiomas may be influenced by the degree of VEG/PF expression within the tumor cells.

Levels of astroprotein (an astrocyte-specific cerebroprotein) in cerebrospinal fluid of patients with brain tumors

1980 ◽  
Vol 52 (2) ◽  
pp. 229-233 ◽  
Author(s):  
Toru Hayakawa ◽  
Kazuyoshi Morimoto ◽  
Yukitaka Ushio ◽  
Takesada Mori ◽  
Toshiki Yoshimine ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Brain Tumors ◽  
Specific Protein ◽  
Intracranial Tumors ◽  
Glial Tumors ◽  
Content Type ◽  
Control Subjects ◽  
Remarkable Degree ◽  
Fine Print

✓ Levels of astroprotein (an astrocyte-specific protein found in the cerebrum) were measured by radioimmunoassay in the cerebrospinal fluid (CSF) of 120 patients with intracranial diseases and eight control subjects. The astroprotein level was elevated (above 25 ng/ml) in 13 of 30 cases (43.3%) of glial tumors, nine of 57 cases (15.8%) of nongliomatous intracranial tumors, seven of 33 cases (21.2%) of non-neoplastic intracranial diseases, but in none of the eight control cases. In glioblastoma patients, CSF astroprotein was elevated in eight of 12 cases (66.7%), in three of them to a remarkable degree (above 500 ng/ml). The possible role of this test is briefly discussed, and the mechanism of increase of the astroprotein levels in the CSF considered.

A comparative study on the pharmacokinetics and biodistribution of boronated porphyrin (BOPP) and sulfhydryl boron hydride (BSH) in the RG2 rat glioma model

1995 ◽  
Vol 83 (1) ◽  
pp. 86-92 ◽  
Author(s):  
Crister P. Ceberg ◽  
Arne Brun ◽  
Stephen B. Kahl ◽  
Myoung Seo Koo ◽  
Bertil R. R. Persson ◽  
...  
Keyword(s):  
Body Weight ◽  
Tumor Cells ◽  
Brain Tissue ◽  
Malignant Gliomas ◽  
Normal Brain ◽  
Boron Hydride ◽  
Content Type ◽  
Rat Glioma ◽  
Glioma Model ◽  
Fine Print

✓ Boron neutron capture therapy is a treatment modality for cancer that depends on the specific uptake of boron by the tumor cells. The infiltrative growth of malignant gliomas requires that boron reach and accumulate in migrating cells outside the margin of the tumor; thus, it is important that the biodistribution of new boron compounds is also studied in the surrounding healthy brain tissue. This study is undertaken in the present work, in which the biodistribution and pharmacokinetics of sulfhydryl boron hydride (BSH) and boronated porphyrin (BOPP) in the RG2 rat glioma model are investigated. This model mimics the characteristics of human glioma with cells migrating into the surrounding brain. The animals were infused intravenously with either BSH (25 µg or 175 µg of boron per gram of body weight) or BOPP (12 µg of boron per gram body weight). For the low dose of BSH, the maximum tumor—boron content was 8 ppm at approximately 9 hours after the infusion with a tumor-to-blood ratio of 0.6. At the higher dose, the corresponding figures were 15 ppm after 12 hours with a tumor-to-blood ratio of 0.5. For BOPP, a tumor—boron concentration of 81 ppm was achieved 24 hours after the infusion and sustained in that range for at least 72 hours. The tumor-to-blood ratio at 24 hours was slightly above 6, but continued to increase as the blood was cleared. These results indicate that both compounds are spread into the normal brain tissue following the same pathways as the migrating tumor cells and in this way can be taken up even in distant tumor cell foci.

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