Evaluation of a Novel Immunochromatographic Assay Using Monoclonal Antibodies against the Matrix Protein of Human Metapneumovirus.

BACKGROUND: The aim of this study was to determine the sensitivity and specificity of a novel immunochromatographic (IC) assay (APD1806) using monoclonal antibodies against the matrix (M) protein of human metapneumovirus (hMPV) for detection of hMPV from nasopharyngeal swab samples based on the results of real-time RT-PCR. METHODS: Nasopharyngeal swab samples taken from 189 patients aged 0 - 5 years who were suspected of having respiratory tract infections associated with hMPV were used in this study. The samples were tested both by the IC assay and by real-time RT-PCR for detection of hMPV. RESULTS: The sensitivity and specificity of the IC assay for detection of hMPV were 88.8% (95/107) and 92.7% (76/82), respectively. CONCLUSIONS: The IC assay using monoclonal antibodies against the M protein of hMPV is an accurate and fast assay that is suitable as a diagnostic tool for hMPV infection. The optimal timing of the IC assay is 12 hours or more after the onset of fever due to hMPV infection.

Measurement of plasma choline in acute coronary syndrome: importance of suitable sampling conditions for this assay.

Blood choline has been proposed as a predictor of acute coronary syndrome (ACS), however different testing procedures might affect the choline concentration because the lysophospholipase D activity of autotaxin (ATX) can convert lysophosphatidylcholine to lysophosphatidic acid (LPA) and choline in human blood. Although the influences of ATX on LPA levels are well known in vivo and in vitro, those on choline have not been elucidated. Therefore, we established suitable sampling conditions and evaluated the usefulness of plasma choline concentrations as a biomarker for ACS. Serum LPA and choline concentrations dramatically increased after incubation depending on the presence of ATX, while their concentrations in plasma under several conditions were differently modulated. Plasma choline levels in genetically modified mice and healthy human subjects, however, were not influenced by the ATX level in vivo, while the plasma LPA concentrations were associated with ATX. With strict sample preparation, the plasma choline levels did not increase, but actually decreased in ACS patients. Our study revealed that ATX increased the choline concentrations after blood sampling but was not correlated with the choline concentrations in vivo; therefore, strict sample preparation will be necessary to investigate the possible use of choline as a biomarker.

Two cases of dissecting aneurysm of the distal posterior inferior cerebellar artery: possible involvement of segmental mediolytic arteriopathy in the pathogenesis.

BACKGROUND: Dissecting aneurysm of the posterior inferior cerebellar artery (PICA) uninvolved with the vertebral artery is rare. The exact pathohistological diagnosis might result in 'unknown' because the underlying pathoanatomical features are, for a variety of reasons, not always identified. CASE DESCRIPTION: We report herein two cases of dissecting aneurysm harbored in different segments of the distal posterior inferior cerebellar artery. In our cases, after trapping the PICA at both just proximal and distal to the aneurysm, the abnormal portion was successfully resected with/without an end-to-end anastomosis. The first patient made a good recovery, while the other died 2 days after the surgery. Although its pathogenetic etiology was unidentified in the second case, the formation of dissecting aneurysm had resulted from a segmental mediolytic arteriopathy in the first case. CONCLUSION: This is the first report of a segmental mediolytic arteriopathy possibly being identified as causing an isolated dissecting aneurysm at this site.

Thrombosed unruptured cerebral aneurysm causing brain infarction followed by subarachnoid hemorrhage--case report--.

A 71-year-old man presented with right hemiparesis and aphasia due to cerebral infarction in the frontal lobe. Computed tomography (CT) revealed a high-density mass, 12 mm in diameter, in the stem of the left sylvian fissure. Carotid angiography demonstrated occlusion of the left ascending frontal artery complex and retention of contrast medium at the bifurcation of the left middle cerebral artery (MCA). The diagnosis was cerebral infarction caused by occlusion of the ascending frontal artery complex resulting from thrombosed left MCA aneurysm. The patient was managed conservatively and his neurological symptoms gradually improved. One month later, he lapsed into a coma. CT revealed subarachnoid hemorrhage. Carotid angiography showed a large left MCA aneurysm with branch occlusion of the left ascending frontal artery complex. A left frontotemporal craniotomy was performed. The MCA aneurysm was opened and the intramural thrombi removed, and finally neck clipping was performed. The patient made a good postoperative recovery.

B7.1 immunogene therapy effectively activates CD(4+) tumor-infiltrating lymphocytes in the central nervous system in comparison with B7.2 gene therapy.

The B7 gene utilizing immunogene therapy is one of the most common methods against tumor growth. However, there is no known study that investigated the difference between B7.1 and B7.2 with regard to B7 gene therapy in the central nervous system (CNS). Therefore, to clarify the difference, we established B7.1 or B7.2 gene transduced tumor cells originating from the murine T cell lymphoma cell line EL4 (EL4-B7.1 or EL4-B7.2). First, we observed the survival time after intracranial inoculation of parent (IC-wt) or genetically modified tumor cells. All mice in control groups (IC-wt or IC-mock) were dead within 16 days. While there was significant survival elongation in the B7.2 modified group (IC-B7.2, p=0.0002), all mice in this group were dead of tumor growth within 22 days. On the other hand, 60% of mice inoculated with EL4-B7.1 (IC-B7.1) survived more than 120 days (p<0.0001). Second, to shed light on the anti-tumor immune response in situ, we tried to analyze CD(4+) tumor-infiltrating T lymphocytes (CD(4+) TIL). To purify and analyze CD(4+) TIL, we had to deplete F4/80(+) microglia because of the CD4 expression. In terms of activation marker expression in CD(4+) TIL, a small population was activated (CD25, 9.8%; CD69, 15.8%) in the control group (IC-wt). In contrast, the activation marker positive CD4+ TIL percentage both in IC-B7.1 (CD25, 25.1%; CD69, 40.1%) and IC-B7.2 (CD25, 16.2%; CD69, 28.3%) appeared to reflect the survival curve in both groups. These findings strongly suggest that, in the CNS, B7.1 gene therapy could effectively introduce CD(4+) TIL activation compared with B7.2 gene therapy. This is the first study clearly describing the difference between B7.1 gene therapy and B7.2 gene therapy in the CNS in terms of the activation status of CD(4+) TIL in situ.

In situ detection of O6-methylguanine-DNA methyltransferase messenger RNA in paraffin-embedded human astrocytic tumor tissues by nested in situ RT-PCR is useful in predicting chemotherapy-resistance of tumors.

O6-methylguanine-DNA methyltransferase (MGMT) is an enzyme that interferes with chemotherapeutic effect of alkylating agents. We performed in situ detection of MGMT mRNA utilizing the nested RT-PCR method in tissue sections (nested in situ RT-PCR). We analyzed 34 samples of paraffin-embedded astrocytic tumor tissue sections with this method [3 astrocytomas, 14 anaplastic astrocytomas (AA), and 17 glioblastoma multiformes (GBM)]. Twenty-five cases (73.5% of all cases) were positive for MGMT either with our method or immunohistochemistry (IHC). Moreover, with our method >25% of the cells in the tumor tissue expressed MGMT in contrast to >4% with IHC among the population of MGMT positive cases. Our method was significantly more sensitive than IHC (p=0.0004). The present results suggest that potentially there is a greater population of MGMT positive cells in astrocytic tumor tissues than the one evaluated with IHC. These findings suggest that the >25% of the MGMT positive cells are involved in the interference with the chemotherapeutic effect of alkylating agents. The MGMT expressing cell population was markedly decreased in GBM compared with AA (26.1% vs 62.1%). The main reason for this marked decrease was that MGMT was expressed in only 9 of 17 cases of GBM in contrast to all AA cases that expressed MGMT. This result suggests that there are potentially two populations of GBM on the basis of MGMT expression, in which the negative population might be mainly composed of de novo GBM. Therefore, it is suggested that our method is practically useful to detect any drug resistance gene product with high sensitivity and would provide a chance to evaluate the chemotherapeutic effect of any agents in an individual patient based manner.

Increased expression and secretion of r-Gsp protein, rat counterpart of complement C1s precursor, during cyclic AMP-induced differentiation in rat C6 glioma cells.

The gene, termed r-gsp, was originally isolated during identification of differentiation-associated molecules in rat C6 glial cells. Its mRNA expression was markedly increased during cAMP-induced glial cell differentiation. The deduced amino acid sequence of r-gsp was homologous to those of complement C1s precursors of hamsters and humans. In the present study, we raised anti-peptide antibody against r-Gsp protein and analyzed its change during cAMP-induced differentiation. The 90-kDa r-Gsp protein increased time-dependently and reached the maximal level ( approximately 7.6-fold increase) at 24 h in response to dibutyryl cyclic AMP (dbcAMP) and theophylline. Moreover, it was secreted into the medium and then was cleaved to form disulfide-linked fragments, one of which was 30 kDa, similar to C1s, suggesting its processing in the extracellular space. In fact, the partially purified r-Gsp from culture medium was cleaved by active human C1r to form a 30-kDa polypeptide. Moreover, secreted r-Gsp protein cleaved human C4alpha to yield C4alpha' and associated with human serum C1-esterase inhibitor, strongly suggesting that r-Gsp protein is rat C1s. However, in C6 cells overexpressing r-Gsp, their morphology and proliferation rate were similar to those in parent C6 cells. These results suggest that r-Gsp protein could not induce glial differentiation alone, and suggest that r-Gsp protein was secreted as a proenzyme and processed in culture medium. Its possible role in glial cell differentiation will be discussed.

Nestin immunoreactivity in local neurons of the adult rat striatum after remote cortical injury.

Nestin is a marker for the neuronal and glial precursor cells and is expressed in reactive astrocytes after brain injury. Following restricted neocortical injury, we found that cells with neuronal morphology in the adult rat striatum became immunoreactive for both nestin and the neuronal marker, microtubule-associated protein 2 (MAP-2), but not for the astroglial marker, glial fibrillary acidic protein (GFAP). The number of nestin-positive cells transiently increased in the striatum. Continuous administration of 5-bromo-2'-deoxyuridine (BrdU) after cortical injury did not reveal any newly generated neurons in the striatum. Double-labeling fluorescent immunocytochemistry revealed that the nestin-positive striatal cells were also substance-P-positive. These findings suggest that some factors released from the injured cortex may induce nestin immunoreactivity in striatal neurons.

Hepatocyte growth factor promotes neuronal differentiation of neural stem cells derived from embryonic stem cells.

We previously reported that hepatocyte growth factor (HGF) promoted proliferation of neurospheres and neuronal differentiation of neural stem cells (NSCs) derived from mouse embryonic brain. In this study, spheres from mouse embryonic stem (ES) cells were generated by floating culture following co-culture on PA6 stromal cells. In contrast to the behavior of the neurospheres derived from embryonic brain, addition of HGF to the growth medium of the floating cultures decreased the number of spheres derived from ES cells. When spheres were stained using a MAP-2 antibody, more MAP-2-positive cells were observed in spheres cultured with HGF. When HGF was added to the growth and/or differentiation medium, more MAP-2-positive cells were also obtained. These results suggest that HGF promotes neuronal differentiation of NSCs derived from ES cells.

Neuronal protein NP25 interacts with F-actin.

Neuronal protein NP25 is a neuron-specific protein present in highly differentiated neural cells, but its functional properties have not been well characterized. NP25 shows high amino acid sequence homology with the smooth muscle cell cytoskeleton-associated proteins, SM22, mp20, and calponin. To gain an insight into the biological functions of NP25, we first examined its subcellular localization in the human neuroblastoma cell line, SK-N-SH. NP25 diffusely distributed in the cytoplasm and fiber-like staining was also observed. It showed that NP25 co-localized with F-actin on stress fibers. A co-sedimentation assay demonstrated that NP25 bound to filamentous actin. Further investigations using fluorescence resonance energy transfer (FRET) technique revealed intracellular binding of NP25 and actin. The significance of the interaction between NP25 and F-actin is discussed.

Cell permeable ROS scavengers, Tiron and Tempol, rescue PC12 cell death caused by pyrogallol or hypoxia/reoxygenation.

The role of superoxide anion (O(2)*-) in neuronal cell injury induced by reactive oxygen species (ROS) was examined in PC12 cells using pyrogallol (1,2,3-benzenetrior), a donor to release O(2)*-. Pyrogallol induced PC12 cell death at concentrations, which evidently increased intracellular O(2)*-, as assessed by O(2)(*-)-sensitive fluorescent precursor hydroethidine (HEt). Caspase inhibitors, Z-VAD-FMK and Z-Asp-CH(2)-DCB, failed to protect cells from injury caused by elevation of intracellular O(2)*-, although these inhibitors had effects on hypoxia- or hydrogen peroxide (H(2)O(2))-induced PC12 cell death. Two known O(2)*- scavengers, Tiron (4,5-dihydroxy-1,3-benzenedisulfonic acid) and Tempol (4-hydroxy-2,2,6,6-tetramethylpiperydine-1-oxyl) rescued PC12 cells from pyrogallol-induced cell death. Hypoxia/reoxygenation injury of PC12 cells was also blocked by Tiron and Tempol. Further understanding of the underlying mechanism of the protective effects of these radical scavengers reducing intracellular O(2)*- on neuronal cell death may lead to development of new therapeutic treatments for hypoxic/ischemic brain injury.

Preoperative construction of an extracranial arterial shunt for resection of an aortic arch aneurysm with occluded left carotid artery.

A 68-year-old man with aortic arch aneurysm was referred to our department. Preoperative carotid echography and magnetic resonance angiography revealed occlusion of the left internal carotid artery. Single-photon emission computed tomography scanning indicated that cerebral blood flow was decreased and reactivity to acetazolamide was reduced in the left temporal lobe. A successful superficial temporal artery-middle cerebral artery anastomosis was first made by neurosurgeons. A postoperative single-photon emission computed tomography scan showed that cerebral blood flow and reactivity to acetazolamide were remarkably improved. Two months after the anastomosis, the aortic arch aneurysm was successfully repaired.

Prediction of neurologic deterioration in patients with lacunar infarction in the territory of the lenticulostriate artery using perfusion CT.

BACKGROUND AND PURPOSE: A significant proportion of patients with lacunar infarctions experience neurologic deterioration after onset. However, no clinical examination has been established for prediction of the progress of symptoms. To determine the hemodynamic predictors of such progression, we performed perfusion CT to quantitatively assess cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) of patients with lacunar infarctions in the territory of the lenticulostriate artery. METHODS: We performed MR imaging and perfusion CT of 26 patients with lacunar infarction within 24 hr after onset. On the CBF map on perfusion CT scans, a round small region of interest was set at the region, with decreased CBF in the territory of the lenticulostriate artery (region of interest 1). Another region of interest was set in the mirror position to region of interest 1 in the contralateral hemisphere (region of interest 2). Using these two regions of interest, CBF, CBV, and MTT were measured. All patients underwent neurologic and MR imaging follow-up while receiving equivalent medical treatment. RESULTS: Neurologic deterioration after onset was shown in 13 patients (progress group), whereas no neurologic deterioration was shown in the other 13 patients (control group). In the progress group, lacunar infarctions were enlarged on follow-up MR images. The ratio of region of interest 1/region of interest 2 showed significantly lower CBF and higher MTT in the progress group than in the control group. CONCLUSIONS: These results suggest that progressive lacunar infarction in the territory of the lenticulostriate artery could be predicted with a higher MTT ratio (>1.26) and a lower CBF ratio (<0.76) on perfusion CT scans obtained within 24 hr after onset.

Emergency image transfer system through a mobile telephone in Japan: technical note.

OBJECTIVE: We report the first application and usefulness of image transfer through a mobile telephone, which can be used between the hospital and another location. METHODS: With this system, brain computed tomographic scans, magnetic resonance images, and angiograms obtained from more than 100 patients in the emergency department were transferred and diagnostically analyzed via a mobile phone. The mobile phone had a 110,000-pixel digital camera and a built-in thin-film transistor liquid crystal display. We reviewed the distribution of pathological characteristics on the transferred images and compared them with the diagnoses made using full-scale original film. RESULTS: This system of transferring images was useful in all cases for correct early diagnosis and early treatment. The quality of magnetic resonance images received was better than that of computed tomographic scans. Hemorrhage provided better contrast than infarction for allowing easy identification. Cerebral angiography revealed small aneurysms if the target area was focused properly. Image quality was sufficient for interpretation despite the small dimensions of the monitor. Ease of operation and portability were both satisfactory. The mean time from commencement of image uptake to complete reception was 2 to 3 minutes. CONCLUSION: The mobile phone system is adequately useful for early diagnosis and initiation of treatment in emergent cases. This is attributable to its low cost and ease of handling for sending images to remote areas and between hospitals, despite the small dimensions of the monitor. Better-quality image transfer will be realized through an advanced mobile phone system based on the new International Mobile Telecommunication 2000 standards, which also will be useful in the development of telemedicine and telecare.

The use of frozen autogenous bone flaps in delayed cranioplasty revisited.

OBJECTIVE: To reevaluate the use of frozen autogenous bone flaps for patients undergoing delayed cranioplasty. METHODS: In the past 12 years, 49 patients have undergone delayed cranioplasty using frozen autogenous bone flaps. Bone flaps removed during the initial operation were sealed in three sterilized vinyl bags and stored at -35 degrees C (n = 37) or -84 degrees C (n = 12) for 4 to 168 days (mean, 50.6 d). The bone flaps were thawed at room temperature and replaced in their original positions. After cranioplasty, we monitored resorption of the bone flaps with computed tomography and evaluated the clinical and aesthetic results. Follow-up periods ranged from 14 to 147 months (mean, 59.2 mo). RESULTS: For 47 patients (95.9%), there were no complications during the follow-up period; there was slight thinning of the bone flap in some cases, but clinical and aesthetic results were highly satisfactory. Resorption was observed for a 12-year-old boy who had undergone cranioplasty, using two pieces of bone flap, 66 days after the initial operation. A 14-year-old boy with a cerebral contusion experienced a bone flap infection. Both patients underwent a second cranioplasty procedure, with ceramic plates. CONCLUSION: The clinical and aesthetic results of delayed cranioplasty using frozen autogenous bone flaps were satisfactory. The most important factor for success was excellent contiguity between the flap and the bone edge.

Ceramide triggers caspase activation during gamma-radiation-induced apoptosis of human glioma cells lacking functional p53.

We have previously shown that treatment of human glioma U87-MG cells expressing wild-type p53 with a DNA topoisomerase II inhibitor, etoposide resulted in ceramide-dependent apoptotic cell death. However, U87-W E6 cells lacking functional p53 due to the expression of human papilloma virus type 16 (HPV-16) E6 oncoprotein were resistant to etoposide. In order to gain insight into the roles of p53 and ceramide in gamma-radiation-induced glioma cell death, we used U87-W E6 and vector-infected U87-LXSN cells. U87-LXSN glioma cells expressing wild-type p53 were relatively resistant to gamma-radiation. U87-W E6 cells, which lost functional p53, became susceptible to radiation-induced apoptosis. Activation of caspase-3, and formation of ceramide by acid sphingomyelinase, but not by neutral sphingomyelinase, were associated with p53-independent apoptosis. Radiation-induced caspase activation and apoptotic death in U87-W E6 cells were modified by the agents which affected ceramide metabolism. SR33557, an inhibitor of acid sphingomyelinase, suppressed radiation-induced caspase activation and then apoptotic cell death. In contrast, N-oleoylethanolamine (OE) and D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), which inhibit ceramidase and UDP-glucose:ceramide glucosyltransferase-1, respectively, and then augment ceramide formation, enhanced radiation-induced caspase activation. These results indicate that glioma cells with functional p53 were relatively resistant to gamma-radiation, and that ceramide may play an important role in caspase activation during gamma-radiation-induced apoptosis of glioma cells lacking functional p53.

Fluorescence-guided resection of glioblastoma multiforme by using high-dose fluorescein sodium. Technical note.

The authors have recently performed a fluorescence-guided tumor resection procedure by using high-dose fluorescein sodium without any special surgical microscopes for the intraoperative visualization of glioblastoma multiforme (GBM), and they report on the actual procedure and clinicopathological findings. Thirty-two patients with GBMs underwent tumor resection during which this fluorescence-guided procedure was used. Fluorescein sodium (20 mg/kg) was intravenously injected after dural opening at the craniotomy site. The tumor was stained almost homogeneously yellow and the color was intense enough to be readily perceived for resection. The center of the solid lesion was stained a deep yellow and surrounded by a transition zone that was faintly stained. The colored lesion was clearly distinguishable from the unstained zone outside the GBM, particularly in the white matter. Both the deeply and faintly stained regions included endothelial proliferation and dense tumor cells. In the unstained region, less dense tumor cells were consistently revealed; however, no endothelial proliferation could be seen. Gross-total resection (GTR) was successful in 84.4% of the patients who received an injection of fluorescein sodium, which accounted for 100% of those in whom all the visible yellow color (both the deeply and faintly stained regions) was judged to have been resected during operation. Gross-total resection was performed in 100% of the patients who underwent the fluorescence-guided procedure and assigned to Stage I, a GBM stage in which, as a therapeutic policy, the tumor should be resected as radically as possible. The GTR rates in patients who received fluorescein sodium were significantly higher than those in patients who did not (73 patients with GBMs who underwent tumor resection without the fluorescence-guided procedure). Although the extent of surgery was revealed to be one of the significant and independent prognostic factors for GBM, the fluorescein sodium-guided resection procedure was not a significant or independent prognostic factor in this series. This surgical procedure does not require any special surgical microscopic equipment and is simple, safe, useful, readily accomplished, and universally available for resection of GBMs. Its efficacy simplifies the surgical procedure of navigating the stained lesion from the unstained area to achieve GTR of GBMs, which can be demonstrated on magnetic resonance images.

Failure of B7.1-modified tumor to evoke full activation of CD8+ tumor-infiltrating lymphocytes in the central nervous system: prevention of parental tumor growth in the subcutaneous environment.

OBJECT: It is well known that the central nervous system (CNS) is an immunologically privileged site. To characterize CD8+ tumor-infiltrating lymphocytes (TILs) recovered from the CNS, the authors compared these cells with TILs recovered from subcutaneous tissue by using a B7.1 gene-modified tumor implantation model. METHODS: The authors established a B7.1 gene-modified EL4 murine lymphoma cell line (EL4-B7.1) and implanted the cells into the CNS to observe the duration of tumor-free survival. Although EL4-B7.1 cells were completely rejected in a subcutaneous implantation model, 40% of animals died after the CNS implantation (all animals in which the parent tumor was implanted died within 16 days). Therefore, the authors isolated TILs from each implantation site and analyzed the expressions of activation antigens CD25 and CD69 by performing the anti-CD8 magnetic beads separation method and flow cytometric analysis. After implantation of the parent tumor, there was no difference in the number of TILs from each site (CD25 1.7-3.2%, CD69 21.9-34.3%). After implantation of the B7.1-modified tumor, the CD25-expressing TIL population from the subcutaneous site was 4.68 times higher than that from the CNS site (17.8% compared with 3.8%). Based on these findings, the authors used a mitomycin C-treated EL4-B7.1 subcutaneous vaccination with various protocols. Vaccination before tumor challenge was sufficient to prevent the development of the tumor. For animals with established tumor, the vaccination protocol was able to prolong host survival (p = 0.0053). CONCLUSIONS: The data clearly demonstrate that the CNS environment fails to activate CD8+ TILs fully. These are the first data indicating in detail a difference between CD8+ TILs from the CNS and those from other sites based on a B7.1-modified tumor model.

Radiological response and histological changes in malignant astrocytic tumors after stereotactic radiosurgery.

Stereotactic radiosurgery is an encouraging approach to deliver higher doses of radiation boost for malignant gliomas safely and precisely. The purpose of this study was to investigate the radiation response and histological changes of malignant astrocytic tumors after stereotactic linac radiosurgery (SLRS). We studied an autopsy case of recurrent glioblastoma multiforme (GBM) and two surgical cases with gross total removal of recurrent GBM and anaplastic astrocytoma transformed from fibrillary astrocytoma treated with SLRS. Destructive changes, such as the disappearance of viable cells, coagulation necrosis, and fibrinoid degeneration of vascular walls, were observed in the center of the target of SLRS, which showed histologically similar radiobiological reactions to well-known delayed central nervous system radiation necrosis caused by conventional radiotherapy. The region showing such radiation necrosis was within the area irradiated with approximately 15-20Gy or more by SLRS; however, dense viable tumor cells remained in the periphery that was irradiated with less than 15Gy. In a comparative immunohistochemical study of the tumors before and after SLRS, neither MIB-1 and p53 labeling indices nor immunoreactivity for GFAP represented any persistent tendencies. There were very few TUNEL-positive cells in either tumor before and after SLRS. These results showed that radiosurgery for malignant gliomas leads to earlier radiation necrosis than conventional radiation and that it is useful in eradicating tumor cells in the center of the target. However, some viable tumor cells may remain in the periphery irradiated with an insufficient dose for cell death and may be partly transformed in character by DNA damage due to radiation. Proton magnetic resonance spectroscopy (MRS) was suggested to characterize the radiation response in radiosurgery tumor targets for correlation with histological findings.

Interleukin-2 activated microglia engulf tumor infiltrating T cells in the central nervous system.

Interleukin-2 (IL-2) has been utilized to treat cancer patient. However, recent studies disclosed that IL-2 induces T cell death. To clarify IL-2 induced T cell apoptosis at tumor sites in the central nervous system (CNS), we utilized an intracranial implantation of IL-2 cDNA transduced murine tumor cells and examined freshly recovered tumor infiltrating T lymphocytes (TIL) with a magnetic beads separation method. CD8(+) TIL recovered from the IL-2 therapy model had three times more apoptosis than a control group, tumor weights at day 12 decreased (0.016 versus 0.041 g/mouse) and the number of TIL per gram of tumor tissue increase more than six times by IL-2 therapy (5.69x10(6) versus 33.7x10(7) cells per mouse). In addition, both activation marker expressions (CD25 and CD69) and cytokine message levels (interferon gamma, and tumor necrosis factor alpha) on CD8(+) TIL decrease in the IL-2 therapy model. Moreover, we detected higher CD8beta message levels in purified tumors associated with F4/80(+) cells from the IL-2 model than the control by a one-step RT-PCR method. Finally, we observed many CD8beta(+) TIL surrounded by numerous infiltrating F4/80(+) cells in the tumor tissues of the IL-2 therapy model by immuno-fluorescence microscopic analysis. Our data show that IL-2 sensitization of apoptosis induction for CD8(+) TIL occurred and the apoptotic T cells were eliminated by F4/80(+) microglia in the CNS. Moreover, this is the first report describing in situ elimination of TIL by F4/80(+) phagocytic cells in the CNS.