agar and Brain-Neoplasms

Topics: Agar; Amino Acids; Brain Neoplasms; Carbohydrates; Central Nervous System Diseases; Cerebrospinal Fluid; Cerebrospinal Fluid Proteins; Cytodiagnosis; Electrophoresis; Humans; Immunoelectrophoresis; Inflammation; Lipids; Methods; Microscopy, Electron; Multiple Sclerosis; Syphilis

In phase II and III trials of gadoteridol (Gd-HP-D03A), a new nonionic, low-osmolar contrast agent, 40 patients with intracranial neoplasms underwent magnetic resonance (MR) imaging with experimental doses of 0.05-0.3 mmol/kg. Fifteen patients also underwent contrast studies with the standard dose (0.1 mmol/kg) of gadopentetate dimeglumine. Both gadopentetate dimeglumine and gadoteridol appear to have a similar effect when given in equal doses (0.1 mmol/kg, n = 5). Lesion enhancement and delineation were better at higher experimental doses (0.2 or 0.3 mmol/kg, n = 7) and worse at a lower experimental dose (0.05 mmol/kg, n = 3). Quantitative analysis of 10 lesions examined with identical imaging protocols revealed a directly proportional relationship (r = .975) between lesion contrast ratio and dose over a range of 0.05-0.3 mmol/kg. Phantom experiments support the clinical results. Improved enhancement, detection, and delineation of central nervous system (CNS) neoplasms resulting from increased injected doses of gadoteridol have the potential to be clinically significant and may justify the possibly higher cost of increased contrast material dosage. Lower doses may not be adequate for the evaluation of most CNS tumors.

Topics: Adult; Agar; Aged; Brain Neoplasms; Contrast Media; Drug Combinations; Drug Evaluation; Female; Gadolinium; Gadolinium DTPA; Heterocyclic Compounds; Humans; Image Enhancement; Magnetic Resonance Imaging; Male; Meglumine; Middle Aged; Models, Structural; Organometallic Compounds; Pentetic Acid; Single-Blind Method

Glioblastoma multiforme (GBM) is a common and fatal disease of the central nervous system. GBM cell lines are fundamental tools used in GBM research. The establishment of novel continuous GBM cell lines with clear genetic backgrounds could facilitate the exploration of molecular mechanisms and the screening and evaluation of antitumor drugs in GBM studies. In the present study, a novel primary glioblastoma cell line was established, named GWH04, from a patient with GBM, and its STR genotype and various tumor parameters were examined. The STR information of GWH04 was identical to that of the original primary tumor tissue. Compared with existing cell lines, GWH04 had a similar

Topics: Agar; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Glioblastoma; Humans; Telomerase; Temozolomide; Xenograft Model Antitumor Assays

Mechanical properties of biological tissues and, above all, their solid or fluid behavior influence the spread of malignant tumors. While it is known that solid tumors tend to have higher mechanical rigidity, allowing them to aggressively invade and spread in solid surrounding healthy tissue, it is unknown how softer tumors can grow within a more rigid environment such as the brain. Here, we use in vivo magnetic resonance elastography (MRE) to elucidate the role of anomalous fluidity for the invasive growth of soft brain tumors, showing that aggressive glioblastomas (GBMs) have higher water content while behaving like solids. Conversely, our data show that benign meningiomas (MENs), which contain less water than brain tissue, are characterized by fluid-like behavior. The fact that the 2 tumor entities do not differ in their soft properties suggests that fluidity plays an important role for a tumor's aggressiveness and infiltrative potential. Using tissue-mimicking phantoms, we show that the anomalous fluidity of neurotumors physically enables GBMs to penetrate surrounding tissue, a phenomenon similar to Saffman-Taylor viscous-fingering instabilities, which occur at moving interfaces between fluids of different viscosity. Thus, targeting tissue fluidity of malignant tumors might open horizons for the diagnosis and treatment of cancer.

Topics: Agar; Aged; Brain; Brain Neoplasms; Disease Progression; Elasticity Imaging Techniques; Extracellular Fluid; Glioblastoma; Heparin; Humans; Magnetic Resonance Imaging; Male; Meningioma; Phantoms, Imaging; Soy Foods; Viscosity; Water

Self-made devices composed of agar and gelatin gel were used for resident training in intra-axial brain tumor resection. The mixture gel of agar and gelatin is retractable and can be suctioned. Hardness of the gel depends on the concentration of the solution. Therefore, by changing the concentration, it is easy to make gels of various hardness.. In this study, a mass of gel that looked like a tumor was placed into another gel that looked like the brain. A part of the "brain" was regarded as the eloquent area. Three types of "tumor" were prepared: hard, moderately hard, and soft tumors. Residents tried to remove the tumor entirely with minimal brain invasion. The training was repeated with 3 types of gel. After resection, the weight of the residual tumor, resected normal brain, and resected eloquent area were measured, and the time taken for removal was recorded.. These data were compared between residents and neurosurgeons. We also analyzed how these data improved with repeated practice. In most cases, residual tumor, resected normal brain, resected eloquent area, and time taken for removal were less in neurosurgeons than in residents. Repeated training made residents more skillful. The responses of the trainees were almost all favorable.. Our devices with "tumors" of various hardness appear to be suitable for resident training in each surgical skill. For the next step of this study, we will attempt to fabricate more practical 3-dimensional gel models for presurgical simulation.

Topics: Agar; Brain Neoplasms; Clinical Competence; Curriculum; Gelatin; Humans; Internship and Residency; Models, Anatomic; Neoplasm, Residual; Neurosurgery; Operative Time; Programmed Instructions as Topic

An approach that facilitates rapid isolation and characterization of tumor cells with enhanced metastatic potential is highly desirable. Here, we demonstrate that plating GI-101A human breast cancer cells on hard (0.9%) agar selects for the subpopulation of metastasis-initiating cells. The agar-selected cells, designated GI-AGR, were homogeneous for CD44(+) and CD133(+) and five times more invasive than the parental GI-101A cells. Moreover, mice injected with GI-AGR cells had significantly more experimental brain metastases and shorter overall survival than did mice injected with GI-101A cells. Comparative gene expression analysis revealed that GI-AGR cells were markedly distinct from the parental cells but shared an overlapping pattern of gene expression with the GI-101A subline GI-BRN, which was generated by repeated in vivo recycling of GI-101A cells in an experimental brain metastasis model. Data mining on 216 genes shared between GI-AGR and GI-BRN breast cancer cells suggested that the molecular phenotype of these cells is consistent with that of cancer stem cells and the aggressive basal subtype of breast cancer. Collectively, these results demonstrate that analysis of cell growth in a hard agar assay is a powerful tool for selecting metastasis-initiating cells in a heterogeneous population of breast cancer cells, and that such selected cells have properties similar to those of tumor cells that are selected based on their potential to form metastases in mice.

Topics: Agar; Animals; Blotting, Western; Brain Neoplasms; Breast Neoplasms; Cell Culture Techniques; Cell Proliferation; Female; Gene Expression; Gene Expression Profiling; Humans; Mice; Mice, Nude; Neoplasm Metastasis; Neoplastic Stem Cells; Reverse Transcriptase Polymerase Chain Reaction; Tumor Cells, Cultured

We have proposed the re-entrant resonant cavity applicator system for non-invasive brain tumor hyperthermia treatment. In this method, a human head is placed in the gap of the inner electrodes. A brain tumor is heated with the electromagnetic field stimulated in the cavity without contact between the human head and the applicator. We have already presented the effectiveness of the heating properties of this system with cylinder-type agar phantoms and by computer simulations. This paper discusses the heating properties of the developed system with the human head-type agar phantom for brain tumor hyperthermia treatment. First, in order to heat deep brain tumors, we tried to heat the human head-type agar phantom by using several electromagnetic field patterns of the resonant frequency. We found that the temperature distributions can be controlled inside the agar phantom by changing the resonant frequencies. Second, to heat local and deep areas of the agar phantom, we tried to achieve heating using the two different resonant frequencies. We found distinct heating properties by changing the electromagnetic field patterns of resonant frequencies. From these results, it was found that our developed heating system can be applied to hyperthermia treatments of deep-seated brain tumors. Further, by changing resonant frequency, treatment can very correspond to the size and the position of a tumor.

Topics: Agar; Amplifiers, Electronic; Brain Neoplasms; Electric Impedance; Electromagnetic Fields; Equipment Design; Heating; Hot Temperature; Humans; Hyperthermia, Induced; Phantoms, Imaging; Temperature; Transducers

In this paper, we discuss the improvement of the speed of AIMS (Automatic Impedance Matching System) to automatically make impedance matching for a re-entrant resonant cavity applicator for non-invasive deep brain tumors hyperthermia treatments. We have already discussed the effectiveness of the heating method using the AIMS, with experiments of heating agar phantoms. However, the operating time of AIMS was about 30 minutes. To develop the ATT System (Automatic Totally Tuning System) including the automatic frequency tuning system, we must improve this problem. Because, when using the ATTS, the AIMS is used repeatedly to find the resonant frequency. In order to improve the speed of impedance matching, we developed the new automatic impedance matching system program (AIMS2). In AIMS, the stepping motors were connected to the impedance matching unit's dials. These dials were turned to reduce the reflected power. AIMS consists of two phases: all range searching and detailed searching. We focused on the three factors affecting the operating speed and improved them. The first factor is the interval put between the turning of the motors and AD converter. The second factor is how the steps of the motor when operating all range searching. The third factor is the starting position of the motor when detail searching. We developed the simple ATT System (ATT-beta) based on the AIMS2. To evaluate the developed AIMS2 and ATT- beta, experiments with an agar phantom were performed. From these results, we found that the operating time of the AIMS2 is about 4 minutes, which was approximately 12% of AIMS. From ATT-beta results, it was shown that it is possible to tune frequency and automatically match impedance with the program based on the AIMS2.

Topics: Agar; Automation; Brain Neoplasms; Computer Simulation; Computers; Electric Impedance; Equipment Design; Humans; Hyperthermia, Induced; Phantoms, Imaging; Signal Processing, Computer-Assisted; Software; Temperature; Time Factors; Transducers

In this paper, we discuss a new system to make impedance matching automatically for a re-entrant resonant cavity applicator for brain tumor hyperthermia treatment non-invasively. We have already discussed about the effectiveness of the heating method using manual type impedance matching controller, with experiments of heating an agar phantom and computer simulations. However, it becomes difficult to perform an accurate impedance matching as resonant frequency becomes high. Here, in order to make a more accurate impedance matching, we developed the automatic impedance matching system (AIMS). We noticed that the reflected power was generated when the impedance matching was not complete. In this system, therefore, to reduce the reflected power fed back, the stepping motor to turn the dial of variable capacitors is controlled by developed software. To evaluate the developed AIMS, the experiments of heating the agar phantom were performed. From these results, we found that the temperature rise of the agar phantom by using AIMS was about 180% of using manual type controller under the same heating condition. It was found that the proposed system was very effective for hyperthermia treatment using resonant cavity applicator even when the resonant frequency was high.

Topics: Agar; Algorithms; Automation; Brain Neoplasms; Computer Systems; Computers; Equipment Design; Humans; Hyperthermia, Induced; Internet; Phantoms, Imaging; Signal Processing, Computer-Assisted; Software; Temperature; Thermodynamics

Breast cancer has a predilection for spreading to bone. The mechanism of preferential metastasis of breast cancer to bone is unknown. We hypothesize that breast cancer cells that develop bone metastases have the capacity to facilitate their colonization in bone. To examine this hypothesis, we established bone-seeking (MDA-231BO) and brain-seeking (MDA-231BR) clones of the human breast cancer cell line MDA-MB-231 by repeated sequential passages in nude mice and in vitro of metastatic cells obtained from bone and brain metastases, respectively. These clones were examined for distinguishing biological characteristics and compared with the MDA-231 parental cells (MDA-231P) in vivo and in vitro. Both the MDA-231BR and the MDA-231BO showed identical tumorigenicity to MDA-231P at the orthotopic site. MDA-231P that was inoculated into the heart developed metastases in bone, brain, ovary, and adrenal glands. On the other hand, MDA-231BO exclusively metastasized to bone with larger osteolytic lesions than MDA-231P. MDA-231BR exclusively disseminated to brain and failed to develop bone metastases. In culture, MDA-231BO produced greater amounts of parathyroid hormone-related protein (PTH-rP) than MDA-231BR and MDA-231P in the absence or presence of transforming growth factor beta (TGF-beta). Furthermore, the anchorage-independent growth of MDA- 231BO in soft agar was not inhibited by TGF-beta, whereas TGF-beta profoundly inhibited the growth of MDA-231P and MDA-231BR. Insulin-like growth factor I (IGF-I) markedly promoted the anchorage-independent growth of MDA-231BO, whereas marginal or no stimulation was observed in MDA-231BR or MDA-231P, respectively. Our data suggest that these phenotypic changes allow breast cancer cells to promote osteoclastic bone resorption, survive, and proliferate in bone, which consequently leads to the establishment of bone metastases.

Topics: Agar; Animals; Bone and Bones; Bone Neoplasms; Brain; Brain Neoplasms; Breast Neoplasms; Cell Adhesion; Cell Culture Techniques; Cell Division; Chemotaxis; Clone Cells; Female; Gene Expression; Humans; Insulin-Like Growth Factor I; Insulin-Like Growth Factor II; Mammary Neoplasms, Experimental; Mice; Mice, Nude; Neoplasms, Experimental; Parathyroid Hormone-Related Protein; Plasminogen Activator Inhibitor 1; Promoter Regions, Genetic; Protein Biosynthesis; Signal Transduction; Transcriptional Activation; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Cells, Cultured

Human glioblastomas (gliomas) are characterized as highly invasive and rapidly growing brain tumors. In this study, we present data on in vitro effect of ascorbyl stearate (Asc-S), a liphophilic derivative of ascorbic acid on cell proliferation, transformation, apoptosis and modulation of expression of insulin-like growth factor-I receptor (IGF-IR) in human glioblastoma multiforme (T98G) cells. Asc-S showed significant inhibition of fetal bovine serum and human recombinant insulin-like growth factor-I (IGF-I) dependent cell proliferation in a dose dependent manner. Treatment of T98G cells with 0, 50, 100 and 150 microM Asc-S for 24h slowed down the cell multiplication cycle with significant accumulation of cells at late S/G2-M phase of cycle. Asc-S treatment (100 microM) reversed the transformed phenotype as determined by clonogenecity in soft agar and also induced apoptosis of T98G. These changes were found to be associated with significant decrease in IGF-IR expression in dose and time dependent manner compared to untreated controls. The data clearly demonstrate that Asc-S has antiproliferative and apoptotic effect on T98G cells probably through modulation of IGF-IR expression and consequent facilitation of programmed cell death.

Topics: Agar; Antineoplastic Agents; Apoptosis; Ascorbic Acid; Blotting, Western; Brain Neoplasms; Cell Cycle; Cell Survival; Clone Cells; Culture Media; Flow Cytometry; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; Immunohistochemistry; In Situ Hybridization; Receptor, IGF Type 1

Strategies that antagonize growth factor signaling are attractive candidates for the biological therapy of brain tumors. HGF/NK2 is a secreted truncated splicing variant and potential antagonist of scatter factor/hepatocyte growth factor (SF/HGF), a multifunctional cytokine involved in the malignant progression of solid tumors including glioblastoma. U87 human malignant glioma cells that express an autocrine SF/HGF stimulatory loop were transfected with the human HGF/NK2 cDNA and clonal cell lines that secrete high levels of HGF/NK2 protein (U87-NK2) were isolated. The effects of HGF/NK2 gene transfer on the U87 malignant phenotype were examined. HGF/NK2 gene transfer had no effect on 2-dimensional anchorage-dependent cell growth. In contrast, U87-NK2 cell lines were approximately 20-fold less clonogenic in soft agar and approximately 4-fold less migratory than control-transfected cell lines. Intracranial tumor xenografts derived from U87-NK2 cells grew much slower than controls. U87-NK2 tumors were approximately 50-fold smaller than controls at 21 days post-implantation and HGF/NK2 gene transfer resulted in a trend toward diminished tumorigenicity. This report shows that the predominant effect of transgenic HGF/NK2 overexpression by glioma cells that are autocrine for SF/HGF stimulation is to inhibit their malignant phenotype.

Topics: Agar; Alternative Splicing; Animals; Autocrine Communication; Brain Neoplasms; Cell Adhesion; Cell Division; Cell Movement; Cell Transformation, Neoplastic; Gene Transfer Techniques; Glioma; Hepatocyte Growth Factor; Humans; Mice; Mice, SCID; Molecular Weight; Neoplasm Transplantation; Phenotype; Transfection; Transplantation, Heterologous; Tumor Cells, Cultured

p125 focal adhesion kinase (p125FAK) is a cytoplasmic tyrosine kinase that is activated upon engagement of integrin cell adhesion receptors, and initiates several signaling events that modulate cell function in vitro. To determine the biologic role of p125FAK in malignant astrocytic tumor cells, U-251MG human malignant astrocytoma cells were stably transfected with p125FAK cDNA using the TET-ON system, and stable clones isolated that exhibited an estimated 5- or 20-fold increase in p125FAK expression on administration of 0.1 or 2.0 microg/ml doxycycline, respectively. In vitro studies demonstrated that induction of p125FAK resulted in a 2- to 3-fold increase in cell migration, increased p130CAS phosphorylation, localization of exogenous p125FAK to focal adhesions, and a 2-fold increase in soft agar growth. To determine the role of p125FAK in vivo, clones were injected stereotactically into the brains of scid mice. A 4.5-fold estimated increase in p125FAK expression was induced by administration of doxycycline in the drinking water. Analysis of xenograft brains demonstrated that, upon induction of p125FAK, there was a 1.6- to 2.8-fold increase in tumor cell number, and an increase in mAb PCNA-labeling of tumor cells in the absence of a change in the apoptotic index. Compared to normal brain, the expression of p125FAK was elevated in malignant astrocytic tumor biopsies from patient samples. These data demonstrate for the first time that p125FAK promotes tumor cell proliferation in vivo, and that the underlying mechanism is not associated with a reduction in apoptosis.

Topics: Agar; Animals; Anti-Bacterial Agents; Astrocytoma; Biopsy; Brain Neoplasms; Cell Division; Cell Movement; Crk-Associated Substrate Protein; Doxycycline; Enzyme Activation; Focal Adhesion Kinase 1; Focal Adhesion Protein-Tyrosine Kinases; Focal Adhesions; Gene Expression Regulation, Neoplastic; Humans; Mice; Mice, SCID; Neoplasm Transplantation; Phenotype; Phosphoproteins; Phosphorylation; Protein-Tyrosine Kinases; Proteins; Retinoblastoma-Like Protein p130; Transplantation, Heterologous; Tumor Cells, Cultured; Vitronectin

To characterize near-resonance saturation pulse MR imaging on a 1.5-T scanner in order to gain insight into underlying mechanisms that alter tissue contrast and to optimize the technique for neuroimaging.. Off-resonance saturation pulses were applied to T1-weighted, spin-density-weighted, and T2-weighted sequences at frequency offsets ranging from 50 Hz to 20,000 Hz down field from water resonance. Suppression ratios were determined at each offset for phantom materials (MnCl2 solution, gadopentetate dimeglumine, corn oil, water, and agar), normal brain structures, and a variety of brain lesions.. Signal suppression of MnCl2 on T1-weighted images occurred at offsets of less than 2000 Hz even though no macromolecules were present in the solution. Only those phantom materials and tissues with short or intermediate T1 relaxation times and relatively large T1/T2 ratios were sensitive to changing frequency offsets. Suppression of brain increased from approximately 20% at 2000 Hz offset to approximately 45% when the offset was reduced to 300 Hz. In human subjects, the net effect of reducing the frequency offset was to increase T2 contrast on T1-weighted, spin-density-weighted, and T2-weighted images. Distilled water and contrast material did not suppress except at very low offsets ( < 300 Hz). A frequency offset of 300 Hz was optimal for maximizing conspicuity between most contrast-enhancing lesions and adjacent brain while preserving anatomic detail.. Suppression of MnCl2 indicates that magnetization transfer is not the sole mechanism of contrast in near-resonance saturation MR imaging. Spin-lock excitation can reasonably explain the behavior of the phantom solutions and the increase in T2 contrast of tissues achieved as the frequency offset is decreased from 2000 Hz to 300 Hz. Below 300 Hz, saturation is presumably caused by spin-tip effects. With our pulse design, an offset of 300 Hz is optimal for many routine clinical imaging examinations.

Topics: Adult; Agar; Brain; Brain Diseases; Brain Neoplasms; Cerebrovascular Disorders; Chlorides; Contrast Media; Corn Oil; Drug Combinations; Electron Spin Resonance Spectroscopy; Female; Gadolinium; Gadolinium DTPA; Humans; Image Enhancement; Macromolecular Substances; Magnetic Resonance Imaging; Male; Manganese Compounds; Meglumine; Middle Aged; Organometallic Compounds; Pentetic Acid; Phantoms, Imaging; Water

Old hemorrhagic lesions in the brain are characteristically surrounded by a band of hemosiderin-containing tissue. This region is typically of low signal intensity on long-echo-time (TE) radio-frequency (RF) spin-echo magnetic resonance (MR) images and on gradient-echo MR images. To determine the cause of signal loss in this band, the authors measured the signal that arises from imaging such a region with use of an RF spin-echo technique with a 180 degrees pulse incrementally displaced from TE/2. The incremental loss of signal was small. Using an agar phantom containing iron particles, the authors also showed that signal loss results primarily from diffusion in magnetic gradients. They conclude that most signal loss in the dark band surrounding areas of late-stage hemorrhage arises from diffusion in areas of magnetic inhomogeneity.

Topics: Adult; Agar; Brain Neoplasms; Cerebral Hemorrhage; Child; Female; Ferrosoferric Oxide; Hemangioma, Cavernous; Humans; Image Enhancement; Iron; Magnetic Resonance Imaging; Male; Mineral Oil; Models, Structural; Oxides; Plant Oils; Propylene Glycols; Water

The soft agar technique for culturing human clonogenic tumor cells has been usefully applied for predicting individual clinical responses to chemotherapy, for screening of new antineoplastic drugs, and in basic biological research. The counting of colonies formed by clonogenic cells is, however, a rather time consuming and inaccurate procedure. We here report a method to combine the easy and precise registration of DNA-synthesis by 3H-thymidine incorporation with the ability of soft agar to permit proliferation of clonogenic cells and inhibit proliferation of non-neoplastic cells. The glioma cell lines U 251 MG and T-MG 1, the benignant glia cells T-BG 1, T-BG 2, T-BG 3 and fibroblasts were cultured in Furcellaran gel. Twenty hours before harvesting 3H-thymidine was added. The Furcellaran gel was resolved by 50 mM LiI. The cells were trapped on glass fiber filters and incorporated radioactivity was measured. 3H-thymidine incorporation in malignant cells increased exponentially with time, while 3H-thymidine incorporation in the benignant glia cells and fibroblasts was inhibited. The correlation between number of colonies counted after 16 days and 3H-thymidine incorporation registered after different culture times was very good. The correlation was best when the cultures were harvested after 8 days (r = 0.95), indicating that it is possible to reduce the assay time. The five glioma biopsies tested grew well with a mean plating efficiency of 0.4% (range 0.02-1.8%). The most intense proliferation seemed to take place during the first week in culture. The good correlation between 3H-thymidine incorporation on day 7 and colony number on day 14 (r = 0.93), indicate that reduction of assay time is possible also for the glioma biopsies.

Topics: Agar; Brain Neoplasms; Cell Division; Cell Line; Cells, Cultured; Clone Cells; Culture Techniques; DNA Replication; Glioma; Humans; Kinetics; Tritium

Topics: Adult; Agar; Amyotrophic Lateral Sclerosis; Brain Neoplasms; Cellulose; Cerebrospinal Fluid Proteins; Electrophoresis; Electrophoresis, Starch Gel; Encephalitis; Female; Friedreich Ataxia; gamma-Globulins; Humans; Huntington Disease; Male; Methods; Multiple Sclerosis; Nervous System Diseases; Osteochondritis; Parkinson Disease; Spinal Neoplasms; Subacute Sclerosing Panencephalitis