[Clinicopathological characteristics and prognosis of diffuse midline gliomas with histone H3K27M mutation: an analysis of 30 cases].

Objective: To analyze the clinicopathological characteristics and prognosis of diffuse midline glioma (DMG) with H3K27M mutation. Methods: Thirty cases of DMG were collected in Guangdong Sanjiu Brain Hospital from October 2016 to May 2018. The patients' clinicopathological data including age, tumor site and histological grade, treatment and follow-up data were collected and analyzed. Results: There were 21 males and 9 females, with a mean age of 26 years (range 5-53 years). Fourteen tumors were located in thalamus, 12 in brainstem (one involved both thalamus and brainstem), and one each in hypothalamus, fourth ventricle, and sellar region, respectively. Two cases presented as diffuse intracranial lesions. Three cases (10.0%) were of WHO grade Ⅰ, 10 cases (33.3%) were grade Ⅱ, eight cases (26.7%) were grade Ⅲ, and nine cases (30.0%) were grade Ⅳ.All patients with gradeⅠ tumors were older than 20 years. Histologically, all were pilocytic astrocytoma-like. Immunohistochemical staining demonstrated that all tumors were IDH1 negative. Twenty-eight tumors showed diffuse expression of H3K27M, and two showed focal expression. Twenty-one tumors(100.0%, 21/21) showed absent expression of H3K27me3. Sixteen tumors (57.1%, 16/28) showed strongly positive expression of p53, and ATRX was negative in eight tumors (38.1%, 8/21). The Ki-67 proliferation index ranged from 5% to 40%. Eight cases (including two cases of H3K27M expression of individual cells) showed K27M mutation in H3F3A gene. Intracranial and spinal cord dissemination occurred in six cases (20.0%, 6/30). Median progression-free survival (PFS) was 9.5 months and median overall survival (OS) was 34 months. Mean PFS was 11.2 months and mean OS was 24.3 months. Compared with adults (>20 years old), children/adolescents (no more than 20 years old) had significantly shorter median OS (8 months vs. 34 months, P=0.013). There was no significant difference in PFS and OS between DMGs located in the brain stem/thalamus and other sites within midline (P>0.05). There was no significant difference in PFS and OS between WHO grade ⅠDMGs and WHO grade Ⅱ-Ⅳ DMGs (P>0.05). Conclusions: DMGs occur more commonly in children and adolescents with male predominance. DMGs present with WHO Ⅰ-Ⅳ tumors morphologically, and pilocytic astrocytoma-like lesions with WHO Ⅰ are more common in adults. Expression of H3K27M but not H3K27me3 is helpful for diagnosis of DMG. The prognosis of children/adolescents is significantly worse than that of adults, whereas histological grade and tumor location do not affect prognosis.

Targeted Therapy as an Alternative to Whole-Brain Radiotherapy in EGFR-Mutant or ALK-Positive Non-Small-Cell Lung Cancer With Brain Metastases.

CLINICAL QUESTION: Is up-front whole-brain radiotherapy required to treat multiple brain metastases from non-small-cell lung cancer when highly active targeted therapies are available? CLINICAL APPLICATION: Patients with EGFR-mutant or ALK-positive non-small-cell lung cancer with brain metastases now have the potential to achieve a prolonged survival. Through use of highly active targeted therapies, whole-brain radiotherapy can be safely postponed, diminishing toxic effects that could impair quality of life.

Intracellular pH measured by 31 P-MR-spectroscopy might predict site of progression in recurrent glioblastoma under antiangiogenic therapy.

PURPOSE: In solid tumors, changes in the expression/activity of plasma membrane ion transporters facilitate proton efflux and enable tumor cells to maintain a higher intracellular pH (pHi ), while the microenvironment (pHe ) is commonly more acidic. This supports various tumor-promoting mechanisms. We propose that these changes in pH take place before a magnetic resonance imaging (MRI)-detectable brain tumor recurrence occurs. MATERIALS AND METHODS: We enrolled 66 patients with recurrent glioblastoma, treated with bevacizumab. Patients received a baseline and 8-week follow-up MRI including 1 H/31 P MRSI (spectroscopy) on a 3T clinical scanner, until progressive disease according to Response Assessment in Neuro-Oncology (RANO) criteria occurred. Fourteen patients showed a distant or diffuse tumor recurrence (subsequent tumor) during treatment and were therefore selected for further evaluation. At the site of the subsequent tumor, an area of interest for MRSI voxel selection was retrospectively defined on radiographically unaffected baseline MRI sequences. RESULTS: Before treatment, pHi in the area of interest (subsequent tumor) was significantly higher than pHi of the contralateral normal-appearing tissue (control; P < 0.001). It decreased at the time of best response (P = 0.06), followed by a significant increase at progression (P = 0.03; baseline mean: 7.06, median: 7.068, SD: 0.032; best response mean: 7.044, median: 7.036, SD: 0.025; progression mean: 7.08, median: 7.095, SD 0.035). Until progression, the subsequent tumor was not detectable on standard MRI sequences. The area of existing tumor responded similar, but changes were not significant (decrease P = 0.22; increase P = 0.28). CONCLUSION: Elevated pHi in radiographically unaffected tissue at baseline might precede MRI-detectable progression in patients with recurrent glioblastoma treated with bevacizumab. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1200-1208.

MRS water resonance frequency in childhood brain tumours: a novel potential biomarker of temperature and tumour environment.

(1)H MRS thermometry has been investigated for brain trauma and hypothermia monitoring applications but has not been explored in brain tumours. The proton resonance frequency (PRF) of water is dependent on temperature but is also influenced by microenvironment factors, such as fast proton exchange with macromolecules, ionic concentration and magnetic susceptibility. (1)H MRS has been utilized for brain tumour diagnostic and prognostic purposes in children; however, the water PRF measure may provide complementary information to further improve characterization. Water PRF values were investigated from a repository of MRS data acquired from childhood brain tumours and children with apparently normal brains. The cohort consisted of histologically proven glioma (22), medulloblastoma (19) and control groups (28, MRS in both the basal ganglia and parietal white matter regions). All data were acquired at 1.5 T using a short TE (30 ms) single voxel spectroscopy (PRESS) protocol. Water PRF values were calculated using methyl creatine and total choline. Spectral peak amplitude weighted averaging was used to improve the accuracy of the measurements. Mean PRF values were significantly larger for medulloblastoma compared with glioma, with a difference in the means of 0.0147 ppm (p < 0.05), while the mean PRF for glioma was significantly lower than for the healthy cohort, with a difference in the means of 0.0061 ppm (p < 0.05). This would suggest the apparent temperature of the glioma group was ~1.5 °C higher than the medulloblastomas and ~0.7 °C higher than a healthy brain. However, the PRF shift may not reflect a change in temperature, given that alterations in protein content, microstructure and ionic concentration contribute to PRF shifts. Measurement of these effects could also be used as a supplementary biomarker, and further investigation is required. This study has shown that the water PRF value has the potential to be used for characterizing childhood brain tumours, which has not been reported previously.

The alternative lengthening of telomere phenotype is significantly associated with loss of ATRX expression in high-grade pediatric and adult astrocytomas: a multi-institutional study of 214 astrocytomas.

Loss-of-function of alpha thalassemia/mental retardation syndrome X-linked (ATRX) protein leads to a phenotype called alternative lengthening of telomeres (ALT) in some tumors. High-grade astrocytomas comprise a heterogeneous group of central nervous system tumors. We examined a large cohort of adult (91) and pediatric (n=88) high-grade astrocytomas as well as lower grade forms (n=35) for immunohistochemical loss of ATRX protein expression and the presence of ALT using telomere-specific fluorescence in situ hybridization, with further correlation to other known genetic alterations. We found that in pediatric high-grade astrocytomas, 29.6% of tumors were positive for ALT and 24.5% were immunonegative for the ATRX protein, these two alterations being highly associated with one another (P<0.0001). In adult high-grade astrocytomas, 26.4% of tumors were similarly positive for ALT, including 80% of ATRX protein immunonegative cases (P<0.0001). Similar frequencies were found in 11 adult low-grade astrocytomas, whereas all 24 pilocytic astrocytomas were negative for ALT. We did not find any significant correlations between isocitrate dehydrogenase status and either ALT positivity or ATRX protein expression in our adult high-grade astrocytomas. In both cohorts, however, the ALT positive high-grade astrocytomas showed more frequent amplification of the platelet-derived growth factor receptor alpha gene (PDGFRA; 45% and 50%, respectively) than the ALT negative counterparts (18% and 26%; P=0.03 for each). In summary, our data show that the ALT and ATRX protein alterations are common in both pediatric and adult high-grade astrocytomas, often with associated PDGFRA gene amplification.

[Changes of electrical property of the twelve source-points in encephaloma patients before and after surgery].

OBJECTIVE: To observe the changes of electrical property of the 12 Source-points in encephaloma patients undergoing surgery. METHODS: A total of 116 encephaloma patients and 60 healthy people who signed the informed consent were enlisted in the present study. The regional cutaneous electric resistance (CER) of the bilateral 12 Yuan (Source)-points was measured in the afternoon (14:00-16:00) before and one week after surgery under room temperature [(22 +/- 3) degrees C, (55 +/- 10)% in humidity] by using "Meridian Energy Analysis Device". RESULTS: In comparison with normal subjects, CER values of the 12 Source-points on both sides of the body in encephaloma patients were significantly lower (P < 0.01). Before surgery, CER values of Wangu (SI 4), Taibai (SP 3), Taichong (LR 3) and Chongyang (ST 42) on the left side were significantly higher than those of the isonym points on the right side (P < 0.01, P < 0.05), suggesting an imbalance of the bilateral Small Intestine, Spleen, Liver and Stomach Meridians. After surgery, CER values of Shenmen (HT 7), Wangu (SI 4), Yangchi (SJ 4) and Taibai (SP 3) on the left side were markedly higher than those of the isonym points on the right side (P < 0.05, P < 0.01), suggesting an imbalance of the bilateral Heart, Small Intestine, Trienergizer and Spleen Meridians. Comparison between pre- and post-surgery showed that CER values of Taiyuan (LU 9), Daling (PC 7), Taibai (SP 3), Taichong (LR 3), Taixi (KI 3), Jinggu (BL 64), Qiuxu (GB 40) and Chongyang (ST 42) on both sides, and Wangu (SI 4) on the right side lessened obviously post-surgery (P < 0.01, P < 0.05), suggesting an imbalance of the bilateral meridians found in more meridians, including yang meridians entering the brain as the Bladder, Gallbladder, Stomach Meridians. CONCLUSION: In encephaloma patients, the CER values of some Source-points on the left side are significantly higher than those on the right side, suggesting an imbalance of the bilateral meridians in functional activities.

Element distribution is altered in a zone surrounding human glioblastoma multiforme.

Recent data indicate that A(1) adenosine receptor (A(1)AR) density is increased in a zone surrounding human and experimental gliomas. On the contrary, tumor tissue and adjacent brain tissue show low to intermediate A(1)AR densities. In order to assess whether changes in A(1)AR expression are indicating further processes of a chemical reorganization of the peritumoral zone, we investigated element concentrations and distribution patterns of copper and zinc in six human glioblastoma multiforme (GBM) specimens by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Uranium and lead were used as external standards. Copper and zinc levels were increased in a peritumoral zone corresponding to the region of elevated A(1)AR density. They showed a lower density in the solid tumor in comparison to surrounding brain tissue, although the cellular density was higher within GBM. Our findings suggest that the immediate vicinity of GBM is characterized by increased levels of copper and zinc supporting the view that higher A(1)AR density surrounding GBM is not an isolated alteration of peritumoral tissue but an indicator of complex changes in the vicinity of infiltrative tumors. Further research is needed to explore the pathophysiological consequences of altered peritumoral element distribution.

Glioneuronal phenotype in a diencephalic pilomyxoid astrocytoma.

We report the presence of divergent populations of cells in a hypothalamic/chiasmatic pilomyxoid astrocytoma of an 11-month-old male, exhibiting differential immunohistochemical localizations for glial fibrillary acidic protein (GFAP) and synaptophysin. The tumor cells were negative for Neu-N and neurofilament protein. Ultrastructurally, the tumor comprised 2 cell types, one with features attributable to a neuronal phenotype alongside cells exhibiting an overt astroglial phenotype. This composite organization was confirmed by confocal microscopy, which revealed 2 distinct, albeit tightly interwoven, populations of GFAP and synaptophysin-labeled tumor cells. Our results indicate that a subset of the so-called pilomyxoid astrocytomas of the hypothalamic/chiasmatic region may represent phenotypically mixed glioneuronal neoplasms distinct from the pilocytic astrocytomas.

STI571 (Gleevec) improves tumor growth delay and survival in irradiated mouse models of glioblastoma.

PURPOSE: Glioblastoma multiforme (GBM) is a devastating brain neoplasm that is essentially incurable. Although radiation therapy prolongs survival, GBMs progress within areas of irradiation. Recent studies in invertebrates have shown that STI571 (Gleevec; Novartis, East Hanover, NJ) enhances the cytotoxicity of ionizing radiation. In the present study, the effectiveness of STI571 in combination with radiation was studied in mouse models of GBM. METHODS AND MATERIALS: Murine GL261 and human D54 GBM cell lines formed tumors in brains and hind limbs of C57BL6 and nude mice, respectively. GL261 and D54 cells were treated with 5 micromol/L of STI571 for 1 h and/or irradiated with 3 Gy. Protein was analyzed by Western immunoblots probed with antibodies to caspase 3, cleaved caspase 3, phospho-Akt, Akt, and platelet-derived growth factor receptor (PDGFR) alpha and beta. Tumor volumes were assessed in mice bearing GL261 or D54 tumors treated with 21 Gy administered in seven fractionated doses. Histologic sections from STI571-treated mice were stained with phospho-Akt and phospho-PDGFR beta antibodies. Kaplan-Meier survival curves were used to study the response of mice bearing intracranial implants of GL261. RESULTS: STI571 penetrated the blood-brain barrier, which resulted in a reduction in phospho-PDGFR in GBM. STI571-induced apoptosis in GBM was significantly enhanced by irradiation. STI571 combined with irradiation induced caspase 3 cleavage in GBM cells. Glioblastoma multiforme response to therapy correlated with an increase in tumor growth delay and survival when STI571 was administered in conjunction with daily irradiation. CONCLUSION: These findings suggest that STI571 has the potential to augment radiotherapy and thereby improve median survival.

In vivo evaluation of the boronated porphyrin TABP-1 in U-87 MG intracerebral human glioblastoma xenografts.

Boron neutron capture therapy (BNCT) is an adjuvant therapy that has the potential to control local tumor growth. A selective delivery of sufficient amounts of boron to individual tumor cells, compared to surrounding normal tissues, is the key for successful BNCT. We have designed and synthesized a new highly water-soluble boronated porphyrin, TABP-1, as a possible BNCT agent. When we injected the maximum tolerated dose (MTD: 15 mg/kg) of TABP-1 systemically into the tail vein of athymic rats bearing intracerebral (i.c.) human glioblastoma U-87 MG xenografts, the compound accumulated preferentially in brain tumors compared to normal brain; however, the level of boron in the tumors was less than the 30 microg/g of tissue that is generally considered necessary for BNCT. We next investigated whether convection-enhanced delivery (CED) could improve the boron distribution. The compound was administered directly into i.c. tumors using an osmotic minipump attached to a brain-infusion cannula. TABP-1 doses from 0.25 to 1.0 mg infused locally over 24 h produced tumor boron concentrations greater than those obtained by systemic administration at the MTD. For example, CED administration of 0.5 mg of TABP-1 produced a tumor boron level of 65.4 microg/g of tumor, whereas the serum level was only 0.41 microg/g (tumor to serum ratio of approximately 160:1). CED also produced relatively high tumor to normal brain ratios of approximately 5:1 for ipsilateral brain and approximately 26:1 for contralateral brain tissues at the 0.5 mg dose. Thus, we may be able to achieve therapeutic BNCT efficacy with minimal systemic toxicity or radiation-induced damage to normal tissue by administering TABP-1 using CED.

Cerebral primitive neuroectodermal tumour in a heifer.

A primitive neuroectodermal tumour (PNET) replacing the thalamus was discovered in an 18-month-old Prim'Holstein heifer. Microscopical examination of the tumour showed large sheets of densely packed cells with occasional Homer-Wright and perivascular rosettes. Neoplastic cells were small with ill-defined borders, scant cytoplasm and ovoid, irregularly shaped nuclei. Immunolabelling was positive for vimentin and neuron-specific enolase, in agreement with previous reports of PNETs in human beings and animals. This appears to be the first report of cerebral PNET in cattle.

Evaluation of TNF-alpha/Bax gene therapy and radiation against C6 glioma xenografts.

Successful therapy of high-grade tumors of the brain is likely to require a combination of new therapeutic approaches. The major goal of the present study was to construct a plasmid-based bax gene vector (pGL1-Bax) and evaluate its expression in vitro and in vivo using athymic mice with subcutaneously growing C6 glioma. Preliminary experiments of efficacy and safety were also performed using pGL1-Bax alone and in combination with previously constructed pGL1-TNF-alpha, as well as with radiation. pGL1-Bax was expressed by C6 cells and was correlated with apoptosis, indicating that the construct and the bax protein were functional. Although intratumoral injections of pGL1-Bax alone, up to total doses of 450 micro g, did not significantly affect tumor growth, consistently smaller tumors were obtained when pGL1-TNF-alpha plus pGL1-Bax were injected 16-18 hr prior to tumor irradiation. Furthermore, in mice with two tumors, one treated and one untreated, progression of the untreated tumor was delayed in the animals receiving all three modalities. No prohibitive toxicities were noted, based on mouse body weights and in vitro assays of blood and spleen. Significant increases in spleen mass, total leukocyte counts, percentage of granulocytes, spontaneous blastogenesis, and CD71-expressing B cells were primarily associated with tumor presence and not treatment type. Overall, the results are promising and suggest that TNF-alpha/Bax gene therapy may be beneficial against highly malignant tumors of the brain. To our knowledge, this is the first report of bax gene therapy used together with radiation in an in vivo glioma model.

[Thalamic intracerebral schwannoma: case report]. / Schwanoma intracerebral talâmico: relato de caso.

The intracranial schwannomas cover about 8% of all the brain tumors, although, those localized inside the encephalic parenchyma are rare only 55 cases being reported in the literature. The histopathologic diagnosis is based on the cellular type and arrangement common to the nervous sheath tumors, the immunohistochemical findings (GFAP, S-100 protein, EMA) and electronmicroscopic findings as well. The clinical presentation related to the intraparenchimatous schwannoma is variable, depending on its localization, the image diagnosis does not show any typical aspect. The surgical treatment is curative once a complete extirpation is obtained. These tumors are benign but one case reported presented malignant signs. We present a patient that had a thalamic schwannoma with histological confirmation. We found no case with this localization in the literature.

Importance of hypoxia in the biology and treatment of brain tumors.

The resistance of gliomas to treatment with radiation and antineoplastic drugs may result in part from the effects of the extensive, severe hypoxia that is present in these tumors. It is clear that brain tumors contain extensive regions in which the tumor cells are subjected to unphysiological levels of hypoxia. Hypoxic cells are resistant to radiation. Hypoxia and the perfusion deficits and metabolic changes that accompany hypoxia in vivo also produce resistance to many commonly used anticancer drugs. The resistance of cells that are hypoxic at the time of therapy may influence the efficacy of the treatment of these tumors with radiation, chemotherapy, and combined modality regimens. Moreover, it is becoming increasingly evident from laboratory studies that exposure of cells to adverse microenvironments produces transient changes in gene expression, induces mutations, and selects for cells with altered genotypes, thus driving the evolution of the cell population toward increasing malignancy and increasingly aggressive phenotypes. Hypoxia may therefore be involved in the evolution of cells in low-grade malignancies to the resistant, aggressive phenotype characteristic of glioblastomas. During the past 50 years, many attempts have been made to circumvent the therapeutic resistance induced by hypoxia, by improving tumor oxygenation, by using oxygen-mimetic radiosensitizers, by adjuvant therapy with drugs that are preferentially toxic to hypoxic cells, by using hyperthermia, or by devising radiation sources and regimens that are less affected by hypoxia. Past clinical trials have provided tantalizing suggestions that the outcome of therapy can be improved by many of these approaches, but none has yet produced a significant, reproducible improvement in the therapeutic ratio, which would be needed for any of these approaches to become the standard therapy for these diseases. Several ongoing clinical trials are addressing other, hopefully better regimens; it will be interesting to see the results of these studies.

Pediatric chordoid glioma with chondroid metaplasia.

Chordoid gliomas are uncommon primary brain tumors that arise in the region of the third ventricle. Reports of this entity to date have been limited to adults. We present a case of a chordoid glioma arising in the hypothalamic/third ventricle region of a 12-year-old male who presented with visual symptoms. The neoplasm consisted of cords and clusters of well-differentiated, spindled-to-rounded cells containing abundant eosinophilic cytoplasm within a prominent mucinous matrix. Unlike other chordoid gliomas, this lesion contained islands and sheets showing cartilaginous differentiation intermixed with the glial component. A graded transition between neoplastic glial and chondroid regions was evident, and cells in both regions were strongly immunoreactive for GFAP and S-100. Cartilaginous metaplasia is infrequent in gliomas, but occurs most often in pediatric neoplasms of the midline such as this chordoid glioma. Thus, chondroid metaplasia represents an unusual histopathologic feature of chordoid glioma-in this case, presenting in a child.

Characterization of lipids from human brain tissues by multinuclear magnetic resonance spectroscopy.

Multinuclear ((1)H, (13)C, and (31)P) magnetic resonance spectroscopy are applied to the biochemical characterization of the total lipid fraction of healthy and neoplastic human brain tissues. Lipid extracts from normal brains, glioblastomas, anaplastic oligodendrogliomas, oligodendrogliomas, and meningiomas are examined. Moreover, the unknown liquid content of a cyst adjacent to a meningioma is analyzed. Two biopsies from glioblastomas are directly studied by (1)H-NMR without any treatment (ex vivo NMR). The (1)H- and (13)C-NMR analysis allows full characterization of the lipid component of the cerebral tissues. In particular, the presence of cholesteryl esters and triglycerides in the extracts of high grade tumors is correlated to the vascular proliferation degree, which is different from normal brain tissue and low grade neoplasms. The (31)P spectra show that phosphatidylcholine is the prominent phospholipid and its relative amount, which is higher in gliomas, is correlated to the low grade of differentiation of tumor cells and an altered membrane turnover. The ex vivo (1)H-NMR data on the glioblastoma samples show the presence of mobile lipids that are correlated to cell necrotic phenomena. Our data allow a direct correlation between biochemical results obtained by NMR and the histopathological factors (vascular and cell proliferations, differentiation, and necrosis) that are prominent in determining brain tumor grading.

Isolation and identification of cDNA fragments and full-length cDNA differentially expressed in human glioblastoma cell line BT-325 versus all-trans retinoic acid induction .

OBJECTIVE: To investigate the differentiation process of the human glioblastoma cells. METHODS: Differential display reverse transcribed-PCR (DDRT-PCR) was used to isolate the genes differentially expressed in control and all-trans retinoic acid treated human glioblastoma cell line BT-325. Routine method of cDNA library screening was performed to clone full-length cDNA. RESULTS: Thirty-six RT-PCR reactions were performed and 64 differentially expressed fragments were recovered, amplified and cloned. Of them, 46 ESTs were sequenced and delivered into the GenBank. The homology comparison using BLAST algorithm revealed that 22ESTs are highly homologous with the known genes and many of them play important roles in the cell differentiation progress. A dot-blot hybridization was conducted to certify the differentiation expression. The result showed that 27 EST clones are expressed at different level in control and all-trans retinoic acid treated BT-325 cells. A full-length cDNA was cloned using the EST-HGBB098. CONCLUSION: DDRT-PCR was a simple and effective method to serially analyze the differentially expressed genes.

Detection of brain tumor invasion and micrometastasis in vivo by expression of enhanced green fluorescent protein.

OBJECTIVE: To determine whether fluorescence from human brain tumor cells transfected with the enhanced green fluorescent protein (EGFP) gene in vitro and xenotransplanted into the brain of nude mice would permit the detection of brain tumor invasion and metastasis in vivo. METHODS: Daoy medulloblastoma cells were transfected with a long terminal repeat-based retroviral vector containing the EGFP gene. Stable EGFP-expressing clones were isolated and stereotactically injected into the frontal cortex of nude mice. Four weeks later, whole brain sections were examined using fluorescence microscopy, immunohistochemistry, and routine hematoxylin and eosin staining for the visualization and detection of tumor cell invasion and metastasis. RESULTS: We demonstrate that EGFP-transduced Daoy cells maintain stable high-level EGFP expression in the central nervous system during their growth in vivo. EGFP fluorescence clearly demarcated the primary tumor margins and readily allowed for the visualization of distant micrometastases and local invasion on the single-cell level. Small metastatic and locally invasive foci, including those immediately adjacent to the tumor's leading invasive edge, were virtually undetectable by routine hematoxylin and eosin staining and immunohistochemistry. EGFP expression also persisted in vitro after cell reculture from brain tissue extracts. CONCLUSION: We show, for the first time, that EGFP-transduced human brain tumor cells can be visualized by fluorescence microscopy after intracerebral implantation. This method is superior to routine hematoxylin and eosin staining and immunohistochemistry for the detection and study of physiologically relevant patterns of brain tumor invasion and metastasis in vivo.

Intravenous infusion of glucose and the vasodilator sodium nitroprusside in combination with local hyperthermia: effects on tumour pH and tumour response in the BT4An rat tumour model.

The influence of sodium nitroprusside (SNP) induced hypotension on the extra-cellular tumour pH during local hyperthermia (HT), and on the cytotoxic effect of HT, was studied in the BT4An tumour transplanted to the hind limb of BD IX rats. Experiments with intravenous infusion of glucose before the HT/SNP combination were also performed. Local waterbath HT was given at 44 degrees C. Sodium nitroprusside was administered as a continuous i.v. infusion to lower the mean arterial blood pressure to 60 mmHg. Glucose was given as an i.v. infusion at a dosage of 4.8 g/kg body weight in 60 min before HT. Extracellular tumour pH was measured by a needle type glass electrode. The tumour pH fell from 7.19 to 6.81, on average, after 60 min HT. Sodium nitroprusside induced hypotension during HT did not increase the pH fall after 1 h HT, but the pH 60 min after discontinuation of HT was lower in this group than in the HT alone group. Pretreatment with glucose before HT gave similar results as the HT/SNP combination. When glucose was given before HT/SNP a highly relevant decline in tumour pH during HT from 7.22 to 5.95 was observed. In a separate tumour response experiment adding SNP to HT was found to prolong the tumour growth time. Pre-treatment with glucose before the HT/SNP combination prolonged the tumour growth time slightly. The applicability of this treatment protocol in the clinical treatment of patients is discussed.

The fatty acid composition of human gliomas differs from that found in nonmalignant brain tissue.

To compare the fatty acid composition of tumor tissue from glioma patients with that of normal brain tissue, tissue samples were obtained from 13 glioma patients and from 3 nonmalignant patients. Following lipid extraction, total fatty acid composition was measured using gas-liquid chromatography. samples were further separated into phospholipids and neutral lipids. Representative samples were then separated into phospholipid classes by thin-layer chromatography and the fatty acid composition assayed. Levels of the polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA), were significantly reduced (P = 0.029) in the glioma samples compared with normal brain samples; mean values were 4.8 +/- 2.9% and 9.2 +/- 1.0%, respectively. This reduction in glioma DHA content was also observed in terms of phospholipids (4.6 +/- 2.1% vs. 9.6 +/- 0.8%, P = 0.002). The phosphatidylserine and phosphatidylethanolamine phospholipid classes were reduced in the glioma samples. Differences were also noted in the n-6 PUFA content between glioma and normal brain samples. The glioma content of the n-6 PUFA linoleic acid was significantly greater (P < 0.05) than that observed in the control samples in terms of total lipids. Thus, the fatty acid composition of human gliomas differs from that found in nonmalignant brain tissue.