Purification and amino acid analysis of two human glioma-derived monocyte chemoattractants.

Two chemoattractants for human monocytes were purified to apparent homogeneity from the culture supernatant of a glioma cell line (U-105MG) by sequential chromatography on Orange A-Sepharose, an HPLC cation exchanger, and a reverse phase HPLC column. On SDS-PAGE gels under reducing or nonreducing conditions, the molecular masses of the two peptides glioma-derived chemotactic factor 1 and 2 were 15 and 13 kD, respectively. Amino acid composition of these molecules was almost identical, and differed from other cytokines that have been reported. The NH2 terminus of each peptide was apparently blocked. When tested for chemotactic efficacy, the peptides attracted approximately 30% of the monocytes added to chemotaxis chambers, at the optimal concentration of 10(-9) M. Potency and efficacy were comparable with that of FMLP, which is often used as a reference attractant. The activity was chemotactic rather than chemokinetic. In contrast to their interaction with human monocytes, the pure peptides did not attract neutrophils. These pure tumor-derived chemoattractants can now be compared with attractants produced by normal cells and evaluated for their biological significance in human neoplastic disease.

Magnetic resonance imaging of pilocytic astrocytomas: usefulness of the minimum apparent diffusion coefficient (ADC) value for differentiation from high-grade gliomas.

BACKGROUND: On contrast-enhanced magnetic resonance (MR) images, pilocytic astrocytomas (PAs) are usually well-enhanced tumors that may mimic high-grade gliomas (HGGs). On the other hand, it has been suggested that areas exhibiting minimum apparent diffusion coefficient (ADC) values reflect the sites of highest cellularity within heterogeneous tumors. PURPOSE: To test the hypothesis that the cellularity of PAs is significantly different to the cellularity of HGGs, which should result in significant differences in minimum ADC values. MATERIAL AND METHODS: Between 1999 and 2005, 15 patients (nine males, six females) with histopathologically confirmed PAs underwent pretreatment MR examination including diffusion-weighted (DW) imaging. We reviewed their MR findings with respect to the size, location, morphology, contrast enhancement, and minimum ADC value of the tumors. The minimum ADC values of the 15 PAs were compared with those of 104 HGGs diagnosed during the same period. RESULTS: The diameter of the 15 PAs ranged from 11 to 60 mm (mean 36 mm); all were located around the ventricles, and all contained enhancing components. All except two small (11 and 14 mm) PAs contained cystic components. The minimum ADC values were significantly higher in PAs (median 1.688, range 1.375-1.897 x 10(-3) mm(2)/s) than HGGs (0.997, 0.543-2.024 x 10(-3) mm(2)/s) (P < 0.0001), although there was substantial overlap. Among the tumors with enhancing components, all but one PA were differentiated from the 76 HGGs with enhancing components (0.922, 0.543-1.462 x 10(-3) mm(2)/s) when the minimum ADC cutoff value was set at 1.5 x 10(-3) mm(2)/s. CONCLUSION: The minimum ADC value may be helpful for the differentiation between PAs and HGGs. A tumor with enhancing components should be PA instead of HGG when the minimum ADC value is higher than 1.5 x 10(-3) mm(2)/s.

Effect of bilateral subthalamic nucleus stimulation on levodopa-unresponsive axial symptoms in Parkinson's disease.

BACKGROUND: The levodopa responsiveness of motor, particularly axial symptoms is a good predictor of the effectiveness of subthalamic nucleus (STN) stimulation in patients with Parkinson's disease (PD). However, many Japanese PD patients are intolerant of higher doses of antiparkinsonian drugs and some aspects of their axial symptoms may remain unresponsive to treatment. We retrospectively investigated the effects of bilateral STN stimulation on the axial signs unresponsive to levodopa in Japanese patients with PD. METHODS: We enrolled 29 consecutive patients into this study. Six independent axial symptoms, i.e. falling, freezing, gait, standing, posture, and postural instability, were scored on the Unified Parkinson's Disease Rating Scale (UPDRS), before and 3 months after bilateral STN stimulation and differences were statistically analysed. FINDINGS: Postoperatively, the mean levodopa dosage was decreased by 27%. The preoperative responsiveness to antiparkinsonian drugs with respect to freezing, gait, posture, and postural instability were positively correlated with postoperative off-medication improvement (p < 0.05). For each individual axial symptom, some patients showed an excellent response to STN stimulation, despite preoperative unresponsiveness to levodopa. These selected patients were not always treated with lower doses of antiparkinsonian drugs preoperatively, but they had milder preoperative scores on the UPDRS with respect to daily activities and overall axial function. CONCLUSIONS: The axial symptoms of PD unresponsive to levodopa were ameliorated by bilateral STN stimulation in patients manifesting a milder degree of preoperative axial signs. Our findings suggest that STN stimulation exerted a definite but limited effect on levodopa-unresponsive axial features, pointing to the need to identify different target structures that control axial functions via non-dopaminergic systems.

Spontaneous resolution of isolated dissecting aneurysm on the posterior inferior cerebellar artery.

The authors report a rare example of an isolated dissecting posterior inferior cerebellar artery (PICA) aneurysm with spontaneous resolution. A 41 year-old male suffered sudden dizziness, nausea and vomiting. An angiogram and magnetic resonance imaging (MRI) detected an isolated PICA dissection. The patient was treated conservatively and recovered without any apparent neurological deficit. MRI detected the self-resolution of the dissecting aneurysm. Dissecting PICA aneurysms, especially non-haemorrhagic lesions, have the possibility of spontaneous resolution resulting in a favorable outcome. The treatment strategy for this vascular lesion may be decided based upon neuroradiological changes on careful follow-up.

Multiple prominent dilated perivascular spaces do not induce Wallerian degeneration as evaluated by diffusion tensor imaging.

It is unknown whether dilated perivascular spaces can affect the adjacent neuronal fibers. We describe conventional MR and diffusion tensor imaging findings of a case with multiple, prominent dilated perivascular spaces in the left cerebral hemisphere. Diffusion tensor imaging showed no alterations in the fractional anisotropy and apparent diffusion coefficient values for the corona radiata, posterior rim of the internal capsule, and the cerebral peduncle, indicating no wallerian degeneration associated with dilated perivascular spaces.

Predictive assessment of shunt effectiveness in patients with idiopathic normal pressure hydrocephalus by determining regional cerebral blood flow on 3D stereotactic surface projections.

BACKGROUND: The regional cerebral blood flow (rCBF) and cerebral metabolism in patients with idiopathic normal pressure hydrocephalus (iNPH) remain to be studied in detail. PURPOSE: Using single-photon emission computed tomography (SPECT), we compared the characteristic rCBF patterns in iNPH patients who did, or did not, respond to shunt operations. MATERIALS AND METHODS: We studied 24 consecutive iNPH patients: 14 men and 10 women aged 68 to 88 years (mean 77.5 years). Using the Japanese normal pressure hydrocephalus grading scale, they were divided into responders and non-responders to shunt operations. Follow-up ranged from 10 to 36 months (mean 25 months). We obtained baseline single-photon emission computed tomography (SPECT) data on three-dimensional stereotactic surface projections (3D-SSP) before and after shunt operations, and compared rCBF in responders and non-responders. RESULTS: On statistical maps, responders manifested significantly lower rCBF in the basal frontal lobes and cingulate gyrus (anterior-dominant). CONCLUSIONS: The preoperative measurement of rCBF by 3D-SSP SPECT may help to identify iNHP patients expected to exhibit a good response to shunt operations.

Pediatric primary CNS lymphoma: longterm survival after treatment with radiation monotherapy.

Primary central nervous system lymphoma (PCNSL) in childhood is very rare. We report a 5-year-old boy who presented with headache and nausea. Magnetic resonance imaging (MRI) showed a faintly enhanced lesion in the left cerebellar hemisphere. MRI-guided biopsy was returned with a histopathological diagnosis of lymphoma. Cranial radiotherapy alone with whole-brain irradiation (30 Gy) followed by a 20-Gy booster to the tumor bed was successful and the patient is alive, well, and in persistent complete remission 14 years post-treatment. This is the only pediatric PCNSL encountered at our institution between 1989 and 2004.

Multiple peripheral middle cerebral artery aneurysms associated with Behcet's disease.

We report a 19-year-old woman with Behcet's disease who suffered a subarachnoid hemorrhage and had bilateral peripheral middle cerebral artery aneurysms. After steroid therapy for 3 days, the smaller aneurysm disappeared. The larger aneurysm was excised and the artery reconstructed using a superficial temporary artery graft. Histological examination showed vasculitis restricted to the wall of the aneurysm. This is the first report of arterial reconstruction for an aneurysm associated with Behcet's disease. Steroid therapy before the operation may facilitate repair of the arterial wall.

Diffusion-weighted imaging of metastatic brain tumors: comparison with histologic type and tumor cellularity.

BACKGROUND AND PURPOSE: On diffusion-weighted imaging (DWI), metastatic tumors of the brain may exhibit different signal intensities (SI) depending on their histology and cellularity. The purpose of our study was to verify the hypotheses (1) that SI on DWI predict the histology of metastases and (2) that apparent diffusion coefficient (ADC) values reflect tumor cellularity. MATERIALS AND METHODS: We assessed conventional MR images, DWI, and ADC maps of 26 metastatic brain lesions from 26 patients, 13 of whom underwent surgery after the MR examination. Two radiologists performed qualitative assessment by consensus of the SI on DWI in areas corresponding to their enhancing portions. We measured the contrast-to-noise ratio (CNR) on T2-weighted images and normalized ADC (nADC) values, and compared them with tumor cellularity. RESULTS: The mean SI on DWI and the CNR on T2-weighted images were significantly lower in well differentiated than in poorly differentiated adenocarcinomas and lesions other than adenocarcinoma. The mean nADC value was significantly higher in well differentiated than poorly differentiated adenocarcinomas and lesions other than adenocarcinoma. All 3 small-cell carcinomas and 1 large-cell neuroendocrine carcinoma exhibited high SI on DWI. The nADC value showed a significant inverse correlation with tumor cellularity. There was no significant correlation between the CNR and tumor cellularity. CONCLUSION: The SI on DWI may predict the histology of metastases; well differentiated adenocarcinomas tended to be hypointense, and small- and large-cell neuroendocrine carcinomas showed hyperintensity. Their ADC values reflect tumor cellularity.

Clinical evaluation of cellulose porous beads for the therapeutic embolization of meningiomas.

BACKGROUND AND PURPOSE: Cellulose porous beads (CPBs) are a new, exceptionally uniformly sized, nonabsorbable embolic agent. We evaluated their efficacy in the preoperative embolization of meningiomas. METHODS: In 141 consecutive patients, we used CPBs (200-microm diameter) for the preoperative embolization of meningiomas. We selected patients whose tumors were > or =4 cm with 50% of blood to the tumor supplied by the external carotid artery (ECA). All patients underwent a provocation test before embolization. The percentage of blood supplied to the tumor by the internal carotid artery and ECA was determined angiographically. Nonenhanced areas on postembolization MR imaging were calculated. Intraoperative blood loss, units of blood transfusion, and hemostasis at the time of surgery were recorded for each patient. The interval between embolization and surgery was intentionally longer than 7 days. RESULTS: Of the 141 patients, 128 underwent CBP embolization. Eleven patients had positive provocation test results, and 2 had vasospasm; they were not CBP embolized. In 72% of the patients CBP embolization achieved reduction in the flow of the feeding artery by more than 50%. The nonenhanced area on MR imaging was not significantly correlated with the degree of ECA supply or devascularization. The interval between embolization and surgery was 8-26 days (mean, 9.9 days). The longer this interval, the greater was the tumor-softening effect and the rate of tumor removal. CONCLUSIONS: CPBs may be useful for the preoperative embolization of meningiomas. To increase the efficacy of CPB embolization, the interval to surgery should be at least 7 days.

Production and characterization of human glioma cell-derived monocyte chemotactic factor.

Since infiltration of monocytes into tumors may be mediated by tumor-derived chemoattractants, we characterized the monocyte-chemotactic activity (MCA) produced by glioma cell lines. The amount of MCA in the culture fluid of five lines tested differed by a factor of 25. U-105MG, the best producer, was selected for further study. After cells reached confluence and the medium was changed, MCA was detected by day 3 and remained at comparable levels on days 4 and 5. The molecular mass of MCA was approximately 17 kilodaltons, and the estimated isoelectric point ranged between pI 7 and pI 9. Because of the high constitutive production of MCA by U-105MG, sufficient material can be obtained for complete chemical characterization of this mediator of inflammation.

Quantitative study of monocyte chemoattractant protein-1 (MCP-1) in cerebrospinal fluid and cyst fluid from patients with malignant glioma.

BACKGROUND: Monocyte chemoattractant protein-1 (MCP-1) is a 76-amino acid protein that attracts monocytes. In vitro studies have reported high levels of MCP-1 messenger RNA expression, as well as the presence of MCP-1, in malignant glioma cells. PURPOSE: Our purpose was to determine whether an MCP-1 assay could be used in a clinical setting 1) to differentiate malignant from benign gliomas and from nontumor disorders of the central nervous system and 2) to detect subarachnoid dissemination of glioma cells. METHODS: MCP-1 levels in cerebrospinal fluid (CSF) and cyst fluid were measured with a sandwich enzyme-linked immunosorbent assay (ELISA) that we had previously developed. We measured MCP-1 levels in CSF samples from 19 patients with malignant glioma (glioblastoma, 10; anaplastic astrocytoma, six; anaplastic oligodendroglioma, two; and ependymoblastoma, one), nine patients with benign glioma, and seven patients with nontumor disorders of the central nervous system. Cyst fluids from four patients with malignant glioma (anaplastic astrocytoma) were also tested. The correlation between MCP-1 concentration in the CSF and subarachnoid dissemination of malignant glioma cells was also studied. RESULTS: The MCP-1 concentration (mean +/- SE) in CSF samples from patients with malignant glioma (2.3 +/- 0.4 ng/mL) was significantly higher than that from patients with benign glioma (0.6 +/- 0.1 ng/mL) (P < .01) or from patients with no tumor (0.5 +/- 0.1 ng/mL) (P < .01). Furthermore, CSF samples from patients with subarachnoid dissemination of malignant glioma contained significantly higher amounts of MCP-1 than those from patients without dissemination (P < .05). Cyst fluids from four of the patients with malignant glioma contained high concentrations of MCP-1. CONCLUSIONS: These results indicate that MCP-1 is produced by malignant glioma in vivo as well as in vitro and suggest that testing for MCP-1 in CSF may be useful in the clinic to differentiate malignant glioma from benign glioma and to detect subarachnoid dissemination of the tumor cells. IMPLICATIONS: The MCP-1 ELISA in CSF may lead to more accurate diagnosis of malignant glioma and detection of subarachnoid dissemination of tumor cells, facilitating selection of patients with these conditions for appropriate therapy.

Intrathecal chemotherapy with 1,3-bis(2-chloroethyl)-1-nitrosourea encapsulated into hybrid liposomes for meningeal gliomatosis: an experimental study.

1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), one of the chloroethyl nitrosoureas, is effective against malignant glioma. To develop its use in intrathecal chemotherapy, we encapsulated BCNU in hybrid liposomes composed of dimyristoylphosphatidylcholine and micellar surfactants (Tween 20) and dissolved it in artificial cerebrospinal fluid (lipo-BCNU). We then studied the toxicity of hybrid liposomes and cellular proliferation inhibition of lipo-BCNU in vitro. We found that 3 mM hybrid liposomes did not affect the viability of human endothelial cells and that lipo-BCNU inhibited the proliferation of human glioma cell lines U-105MG, U-251MG, and U-373MG, and rat glioma cell lines C6 and 9L in a concentration-dependent fashion. Wistar rats that were administered lipo-BCNU intracisternally showed no weight loss, neurological symptoms, or histological changes of the brain and spinal cord. A Wistar rat model of meningeal gliomatosis was established by intracisternal inoculation of 0.1 ml cell suspension containing 1 x 10(6) or 5 x 10(6) viable C6 glioma cells. Two days after inoculation, lipo-BCNU (BCNU, 2.5 mg/kg) was administered intracisternally. When 1 x 10(6) glioma cells were inoculated (experiments 1 and 2), the median survival times were 24.5 and 26 days in the control groups and 32 and 45 days in the lipo-BCNU-treated groups. respectively. When 5 x 10(6) glioma cells were inoculated (experiments 3-6), the median survival times were 17-29.5 days in the control groups and 23-44 days in the treated groups, respectively. Significantly prolonged survival was obtained in three of six experimental groups. After the administration of 1 ml lipo-BCNU (BCNU, 4.67 mM) or 1 ml BCNU solubilized with 5% dextrose/water (BCNU, 4.67 mM) into the cisterna magna of dogs, the cisterna magna cerebrospinal fluid was sampled, and the BCNU concentrations were assayed by high-performance liquid chromatography. The half-life of the lipo-BCNU was longer than that of BCNU solubilized with 5% dextrose/water. These results suggest that the intrathecal administration of lipo-BCNU may be possible for the treatment of meningeal gliomatosis.

Neurotoxicity and pharmacokinetics of intrathecal perfusion of ACNU in dogs.

To test the feasibility of intrathecal perfusion of ACNU (3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-1-(2-chloroethyl)-1-nitro sou rea hydrochloride) in the treatment of subarachnoid dissemination of malignant glioma, the neurotoxicity and pharmacokinetics of ACNU were studied in dogs. ACNU [1-2 mg dissolved in 10-20 ml of lactated Ringer's solution or artificial cerebrospinal fluid (CSF)] was administered via the right lateral ventricle by constant drip infusion and CSF was drained by lumbar puncture. The infusion time was from 15 to 71 min. For the control, a bolus injection was given. No neurological and systemic symptoms were noted after perfusion. Histological examination of the brain and spinal cord revealed only mild denudation of ependyma in the wall of the ventricles in a dog treated three times with 2 mg ACNU (perfusion twice, bolus injection once) and in 2 dogs perfused with 1 mg ACNU once a week for 10 weeks. ACNU was not detected in lumbar CSF after bolus injection into the lateral ventricle. When 1 mg of ACNU, dissolved in 10 ml of artificial CSF, was perfused for a duration of 22 to 31 min, it started to appear in the lumbar CSF 10 to 15 min after the start of perfusion, reaching a maximum concentration of 13.88 to 22.31 micrograms/ml. The area under the drug concentration-time curve was 344 to 706 micrograms x min/ml; the half-time was 15.5 to 19.5 min. The distribution volume was 30.6 to 54.1 ml. These findings suggest the feasibility of intrathecal perfusion of ACNU in the treatment of patients with subarachnoid dissemination of glioma.

High-efficiency in vivo gene transfer using intraarterial plasmid DNA injection following in vivo electroporation.

A novel method for high-efficiency and region- controlled in vivo gene transfer was developed by combining in vivo electroporation and intraarterial plasmid DNA injection. A mammalian expression plasmid for the Escherichia coli lacZ gene (driven with a SV40 early promoter) was injected into the internal carotid artery of rats whose brain tumors (from prior inoculation) had been electroporated between two electrodes. The lacZ gene was efficiently transferred and expressed in the tumor cell 3 days after plasmid injection. However, neither any gene transfers nor any elevated lacZ activity was detected in tissues outside the electrodes. The plasmid was not transferred without electroporation. Human monocyte chemoattractant protein-1 cDNA was also transferred by this method, and its long-lasting (3 weeks) expression was confirmed by using the Epstein-Barr virus episomal replicon system. The expressed monocyte chemoattractant protein-1 protein was functional, as evident by the presence of a large number of monocytes in tumor tissue. This method, electrogene therapy, which does not require viral genes or particles, allows genes to be transferred and expressed in desired organs or tissues, and it may lead to the development of a new type of highly effective gene therapy.

Identification of a human homolog of the Drosophila neuralized gene within the 10q25.1 malignant astrocytoma deletion region.

The loss of chromosome 10 is the most frequent genetic alteration found in malignant astrocytomas. In particular, the long arm of chromosome 10 was previously reported to have two or more common deletion regions where tumor suppressor genes may be located. In this study, we performed deletion mapping of 44 malignant astrocytomas using 12 microsatellite markers on chromosome 10q and demonstrated that the minimal common region of loss of heterozygosity (LOH) was present between D10S192 and D10S566 localized at 10q25.1. Subsequently, we have identified a novel gene, termed h-neu, within the region frequently deleted and found that h-neu encodes a protein with strong homology to the Drosophila neuralized (D-neu) protein. Northern blot and RT-PCR analyses revealed that h-neu mRNA was expressed at very low levels in human malignant astrocytoma tissues and the majority of glioma cell lines examined, while normal brains expressed h-neu transcript. Furthermore, DNA sequencing analysis of the h-neu transcript revealed one of the glioma cell lines, U251MG, had a single nucleotide substitution which resulted in an amino acid change from glycine (GGC) to serine (AGC) at codon 253. The D-neu gene is known to serve a critical function in neurogenesis in Drosophila, and loss-of-function mutations produce hyperplasia of primitive neuronal cells. These observations led us to hypothesize that h-neu gene plays a role in determination of cell fate in the human central nervous system and may act as a tumor suppressor whose inactivation could be associated with malignant progression of astrocytic tumors.

Serial changes in the regional cerebral blood flow of patients with hypertensive intracerebral hemorrhage -- long-term follow-up SPECT study.

We analyzed serial changes in the regional cerebral blood flow (rCBF) of 13 patients with intracerebral hemorrhage by single photon emission computed tomography (SPECT) during the acute- to chronic stage (2 hr to 55 weeks). The (99m)Tc-ethyl cysteinate dimmer ((99m)Tc-ECD) was used as the nuclear mediator. The SPECT timing within 48 hours after the onset was considered to be acute stage, from 48 hours to 4 weeks to be subacute stage, and after 4 weeks to be chronic stage. The region of interest was each hemisphere in the whole brain without ventricles at the thalamic level. For semi-quantitative analysis of rCBF, we used the Brain Uptake Ratio method. Of the 13 patients (mean age 65.5 years), 3 had thalamic-, 4 putaminal-, 5 subcortical-, and one a cerebellar hemorrhage; the hematoma volume varied from 4-50 ml (<20 ml, n=9; 20-30 ml, n=1; >30 ml, n=3; mean 17 ml). The rCBF changes during the long-term follow-up were classified as increase-, decrease-, and unchanged type. Of 5 patients with increased rCBF, 4 made a good recovery and one was severely disabled; of 5 patients with decreased rCBF, 1 made a good recovery, 3 were moderately-, and one was severely disabled. All 3 patients with unchanged rCBF were moderately disabled. Our findings suggest that among patients with hypertensive intracerebral hemorrhage, those with increased rCBF over time may have a favorable outcome. We further need more cases with intracerebral hemorrhage to clarify this trend.

Inhibitory effect of epigallocatechin-gallate on brain tumor cell lines in vitro.

We investigated the effect of epigallocatechin-gallate (EGCG), the main constituent of green tea polyphenols, on human glioblastoma cell lines U-373 MG and U-87 MG, rat glioma cell line C6, and rat nonfunctioning pituitary adenoma cell line MtT/E. Cell viability was determined by assay with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), and the extent of apoptosis was studied by flow cytometric analysis. Apoptosis was also characterized by morphology using fluorescent microscopy. The role of insulin-like growth factor-I (IGF-I) was studied by assay with MTT, immunohistochemistry, and immunoradiometric assay. After 72-h exposure, a statistically significant loss of viability (P = < 0.0001) was observed at concentrations of 12.5, 25, 50, and 100 microg/ml in U-373 MG cells and U-87 MG cells. EGCG at concentrations of 50 microg/ml and higher significantly reduced the viability of C6 cells. EGCG inhibited viability of MtT/E cells only at a concentration of 100 microg/ml. Quantitative study by flow cytometry demonstrated that lower doses of EGCG (12.5, 25, 50 microg/ml) induced apoptosis in U-373 MG, U-87 MG, and C6 cells; however, only the highest dose (100 microg/ml) induced apoptosis in MtT/E cells. Compared with other cell lines, MtT/E cells showed stronger IGF-I immunoreactivity. Neutralization of IGF-I with an antihuman IGF-I antibody reduced viability of the cell lines. It can be concluded that EGCG has an inhibitory effect on malignant brain tumors, and IGF-I may be involved in the effects of EGCG.

Differentiation of glioma-cells by a pdgf-antagonist.

We previously reported that trapidil, a Platelet-derived Growth Factor (PDGF) antagonist, can inhibit the proliferation of PDGF-dependent glioma cells. In the current study, we explored the effect of trapidil on the differentiation of glioma cells by observing the morphological changes in glioma cells in control and trapidil-treated cultures under a phase contrast microscope. Most cells in the control cultures were flat, large, and irregularly shaped. On the other hand, most cells treated with trapidil formed several long cytoplasmic processes and exhibited fibrous morphology. Western blots and immunocytochemical analysis of glial fibrillary acidic protein (GFAP)-stained, trapidil-treated cultures revealed an increase in GFAP content over the control cultures. From these results we propose that trapidil induces the differentiation of glioma cells.

Increased monocyte chemoattractant protein-1 expression by tumor necrosis factor-alpha can mediate macrophage infiltration in gliomas.

We compared the in vitro effects of various cytokines on the expression of monocyte chemoattractant protein-1 (MCP-1) in glioma cell lines and found that MCP-1 expression was highly induced by tumor necrosis factor-alpha (TNF alpha) and interleukin-1 beta. The intra-tumoral injection of TNF alpha in rat glioma model increased the in vivo expression of MCP-1 at 1 to 12 h after the injection and induced macrophage infiltration into tumor tissue. The injection of TNF alpha into post-operative tumor cavity of human malignant glioma also increased the concentration of MCP-1 in the cavity fluid at 24 to 38 h after injection. These data, together with the previous finding that the growth of transplanted MCP-1-transfected cells was significantly inhibited by infiltrated macrophages, suggest that injection of TNF alpha inhibits turner growth via the induction of MCP-1 expression.