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Experimental and human brain neoplasms: detection with in vivo sodium MR imaging.

Elevations of intracellular sodium concentration have been observed in rapidly proliferating cells and malignant neoplasms. Sodium magnetic resonance (MR) imaging (with repetition times of 133 msec and echo times of 13, 26, 39, and 42 msec) was performed in ten patients and three dogs with central nervous system neoplasms. In all instances the neoplasms were associated with an increased sodium signal compared with that of normal brain. Unfortunately, the available echo times did not enable discrimination of intracellular sodium from extracellular sodium, which was present in high concentrations in adjacent vasogenic edema fluid. Further study is necessary to establish the utility of sodium MR imaging for the investigation of malignant neoplasms.

Animals↗

Cysticercosis mimicking brain neoplasm: MR and CT appearance.

The clinical and radiologic manifestation of neurocysticercosis are varied. Since the introduction of anticysticercal drugs, surgery is only rarely needed in treatment. During the last 2 years, we have encountered two patients with minimal symptomatology whose cerebral CT and magnetic resonance studies demonstrated single lesions consisting of an enhancing nodule surrounded by edema. There was ring enhancement of the nodule in one case and homogeneous enhancement in the other. Surgery was performed in both cases, because the primary consideration was brain tumor.

Adult↗

Papillary glioneuronal tumor--a new variant of benign mixed brain neoplasm.

We report a case of a 14-year-old girl with papillary glioneuronal tumor (PGNT) in right parietal lobe. On MRI the tumor presented as a contrast enhancing mass with small central hypodense area and consisted of areas similar to central neurocytoma intermixed with vessels surrounded with glial cells. There were also small loose areas superficially reminding DNT. Neurocytic component presented strong synaptophysin immunostaining, while intermixed glial element presented GFAP-immunopositivity. Our case is similar to previously reported PGNT, but an important difference lies in not distinct cystic formation and a presence of loose, edematous tissue. PGNT may be regarded as a variant of ganglioglioma or as a complex variant of extraventricular neurocytoma and belongs to a wide group of benign, dysembryoplastic or even hamartomatous neuroepithelial tumors, which may differentiate into both, glial or neuronal direction: pleomorphic astrocytoma may posses neurocytic differentiation, desmoplastic infantile ganglioglioma may be regarded as complex superficial dural astrocytoma and DNT may present gliomatous areas (complex DNT). Also other rare tumors reminding DNT have been reported: DNT-like neoplasm of septum pellucidum and rosetted glioneuronal tumor. From this point of view it is important to remember that such a wide spectrum may be difficult to discriminate into very narrow clinico-pathological entities.

Adolescent↗

[Usefulness of melatonin in the diagnostics and therapy of pineal gland and brain neoplasms].

Melatonin or N-acetyl-5-methoxytryptamine is mainly produced by pineal gland and exhibits characteristic diurnal rhythm of synthesis and secretion with the highest levels at night and low levels during a day. For several years the knowledge of pineal gland and its hormone was rather poor. It was last years when knowledge of the role of melatonin in health and different diseases was developed. Nowadays we are aware that melatonin plays important role in diagnosis and therapy of several diseases, and may be helpful factor also in neurosurgery. Author presents the review of the present knowledge on the role of melatonin in diagnosis of pineal region pathology and treatment of brain tumors.

Brain Neoplasms↗

Antitumor activity and reporter gene transfer into rat brain neoplasms inoculated with herpes simplex virus vectors defective in thymidine kinase or ribonucleotide reductase.

Herpes simplex virus (HSV) mutants or recombinant vectors might be useful oncolytic agents. Three general types of HSV vectors can be potentially used for this purpose: (1) mutants in viral transcription factors, such as ICP0 and ICP4; (2) mutants in enzymes involved in nucleic acid metabolism, such as thymidine kinase (TK) and ribonucleotide reductase (RR); and (3) mutants in neurovirulence factors, such as gamma 34.5. We tested the destructive ability of each type against rat 9L gliosarcoma cells in culture. We found that the HSV vectors defective in TK or RR were more efficient at tumor cell lysis in culture than the other types of HSV vectors. This increased efficiency provided the rationale for evaluating the TK and RR mutants in vivo following their stereotactic inoculation into 9L gliosarcomas implanted in rat brains. We employed the X-gal enzymatic histochemical assay to show that HSV-mediated lacZ gene expression was present in cells within the tumor mass in a relatively selective fashion. Immunoreactive HSV capsid and core antigens were present both in cells within the tumor, as well as in cells such as neurons and astrocytes, directly adjacent to the tumor mass. Long-term survival studies revealed that rats treated with either the TK or RR mutant lived significantly longer than control rats (p = 0.014, Kruskal-Wallis one-way analysis of variance). These results indicate that HSV vectors, defective in enzymes needed in nucleic acid metabolism, can preferentially mediate lacZ gene expression in cells within the tumor. (ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Problems in anesthesia and resuscitation in the surgical treatment of brain neoplasms].

The Authors analyse and discuss some particular problems related to anaesthesia in neurosurgery according to the patient's clinical and neurological status and to the surgical treatment. The evaluation of systemic and neurological physiopathology during pre-, per- and post-operative periods are important for this analysis. Therefore anaesthesia and intensive care methods are attentively discussed. Intracranial pressure, cerebral blood flow, metabolism, intracranial space-occupying lesions and surgical techniques are the main factors interfering with anaesthesia in neurological surgery.

Anesthesia, General↗

Cellular components of microvascular proliferation in human glial and metastatic brain neoplasms. A light microscopic and immunohistochemical study of formalin-fixed, routinely processed material.

Since the origin of cells contributing to microvascular proliferation (MVP) in glial neoplasms is unsettled, a light microscopic and immunohistochemical study for vascular smooth muscle cells and endothelial cells was performed in formalin-fixed, routinely processed brain tumor biopsy material. MVP in glial neoplasms was compared with that in intracerebral metastatic carcinomas and in intracranial granulation tissue. On the basis of the degree of hyperplasia of hypertrophic cells in the microvascular wall, MVP was subjectively divided into mild, moderate, and glomeruloid (marked) proliferation. The relative contribution of vascular smooth muscle cells and endothelial cells to different degrees of MVP was estimated immunohistochemically using antibodies against alpha-smooth muscle actin and von Willebrand factor, respectively. Glomeruloid MVP occurred in 50% of the malignant glial neoplasms. Moderate MVP was found in most malignant gliomas and in some pilocytic astrocytomas. Glomeruloid MVP was present in peritumoral glial tissue in 4 out of 15 intracerebral metastatic carcinomas, while only mild to moderate MVP was found within these tumors. In granulation tissue MVP was mild. In glomeruloid and moderate MVP vascular smooth muscle cells were more hypertrophic and more numerous than endothelial cells. The contribution of hypertrophic vascular smooth muscle cells to mild MVP was variable. MVP in glial neoplasms was generally not accompanied by a matrix of fibrous stroma but was directly embedded in glial tissue. The architecture of this MVP suggested "in situ" proliferation of microvascular cells without migration of these cells into the surrounding tissue.

Actins↗

Genetics of brain neoplasms.

Transformation of a normal cell into a malignant cell involves a series of events that damage the genome. Gliomas are the most common adult neoplasm of the central nervous system. To develop new therapeutic strategies requires an understanding of the specific lesions that occur and contribute to this malignant process. Initially, data reported from the analyses of human gliomas were quite variable. This has recently changed as more data have become available and the selection of tissue analyzed is coupled with clinical criteria. Specific genetic lesions are now defining different glioma pathways, and some aberrations may be indicative of therapeutic response. This review focuses on the specific genetic aberrations associated with astrocytic and oligodenroglial tumors.

Adolescent↗

Long-term survival of rats harboring brain neoplasms treated with ganciclovir and a herpes simplex virus vector that retains an intact thymidine kinase gene.

Survival of rats harboring cerebral 9L gliosarcomas can be significantly extended by an intratumoral inoculation with a herpes simplex virus vector, designated as hrR3. This vector, which bears the lacZ reporter gene, is defective in the gene encoding ribonucleotide reductase, allowing for replication in dividing tumor cells but not in postmitotic neural cells. It also possesses an intact viral thymidine kinase (TK) gene, which confers chemosensitivity to ganciclovir. In this study, the ability of ganciclovir to potentiate the antitumor effect of hrR3 was evaluated. In culture, there was a 23% decrease in the growth of 9L cells treated with hrR3 plus ganciclovir compared to hrR3 alone (P < 0.01). The combination of hrR3 plus ganciclovir led to the long-term survival of 48% of rats harboring intracerebral 9L gliosarcomas compared to 20% survival in the hrR3 group (P < 0.05). Ganciclovir treatment had no effect on the growth of tumor cells in vitro or in vivo when a herpes simplex virus vector with a defective TK gene was used. Immunocytochemistry confirmed selective expression of the TK gene in cells within the tumor. These findings indicate that the TK gene can potentiate the antitumor effect of the hrR3 herpes simplex virus vector and provide the basis for placing additional therapeutic genes in the genome of hrR3.

Animals↗

Computer-assisted stereotaxic laser resection of intra-axial brain neoplasms.

Computer interpolation of stereotaxic computerized tomography (CT) scanning data allows the transposition of a tumor volume in stereotaxic space. A stereotaxically directed and computer-monitored CO2 laser is then utilized to vaporize that volume as the surgeon monitors the position of a cursor representing the laser beam against planar contours of the tumor displayed on an operating room computer monitor. Computer-assisted stereotaxic laser microsurgery provides precise three-dimensional control for aggressive resection of deep-seated tumors from neurologically important areas with acceptable postoperative results. Thus, a significant cytoreduction can be achieved in addition to providing a tissue diagnosis and internal decompression. The authors report 83 computer-assisted stereotaxic laser procedures for tumor excision in 78 patients. The tumors were located in the thalamus/basal ganglia in 15 patients, ventricular system in five, corpus callosum in four, brain stem in three, and deep and centrally in the hemispheres in 51. Histologically, there were 26 glioblastomas, seven grade III astrocytomas, 14 grade II astrocytomas, 14 metastatic tumors, nine vascular lesions, and eight miscellaneous lesions. Resection of these subcortical lesions was confirmed by postoperative contrast-enhanced CT scanning. Neurological examinations performed 1 week after the 83 procedures revealed that 48 patients had improved from their preoperative level and 23 were unchanged (12 were neurologically normal preoperatively). Twelve patients had an increase in a preoperative neurological deficit, three of whom died in the postoperative period: one from infection, one from pulmonary emboli, and one from brain-stem edema. The average survival period (37.6 weeks) of patients having glioblastomas treated by this technique and irradiation was no different from that of patients having glioblastomas in more favorable locations treated by conventional surgery and irradiation. Patients with circumscribed lower-grade astrocytomas did better in terms of morbidity and completeness of resection than those with infiltrative neoplasms. Other circumscribed lesions, such as metastatic tumors, vascular lesions, and intraventricular tumors, were easily resected by the technique described.

Adolescent↗

Radiation therapy for neoplasms of the brain.

The effectiveness and complications of radiation therapy for brain neoplasms are reviewed. While the available data suggest a favorable influence and outcome, randomized studies are needed to further optimize radiation therapy techniques and to integrate new therapeutic modalities.

Astrocytoma↗

[Intrathecal synthesis of immunoglobulins G in patients with nervous system neoplasms].

Brain tumor development and their recurrence are accompanied by an increase in IgG levels in liquor as well as in the number of circulating immunocomplexes and by the presence of blockage factors in liquor. The data presented in the paper, on the whole, illustrate the development of autoimmune reactions, which happen to be mechanisms involved in the pathogenesis of brain tumor growth and recurrence. Surgical removal of tumor is followed by a reduction in the rates of IgG synthesis.

Brain Neoplasms↗

[Clinical aspects of glial and metastatic neoplasms of brain].

Results of surgical treatment of 253 patients with glial tumors and 47 patients with metastatic tumors of the brain are analyzed. An analysis with CT and MRT was used in the preoperative diagnosis for the calculation of the tumor volume and the dislocation degree. Microsurgical technologies used in the treatment allowed to shorten the period of postoperative rehabilitation, to reduce the development of neurological deficit that created conditions for early postoperative X-ray and chemotherapy.

Adolescent↗