Vaccine therapy with dendritic cells transfected with Il13ra2 mRNA for glioma in mice

OBJECT

The Il13ra2 gene is often overexpressed in brain tumors, making Il13ra2 one of the vaccine targets for immunotherapy of glioma. In this study, using a mouse glioma model, the authors tested the hypothesis that vaccination using dendritic cells transfected with Il13ra2 mRNA induces strong immunological antitumor effects.

METHODS

A plasmid was constructed for transduction of the mRNAs transcribed in vitro into dendritic cells. This was done to transport the intracellular protein efficiently into major histocompatibility complex class II compartments by adding a late endosomal/lysosomal sorting signal to the Il13ra2 gene. The dendritic cells transfected with this Il13ra2 mRNA were injected intraperitoneally into the mouse glioma model at 3 and 10 days after tumor cell implantation. The antitumor effects were estimated based on the survival rate, results of histological analysis, and immunohistochemical findings for immune cells.

RESULTS

The group treated by vaccination therapy with dendritic cells transfected with Il13ra2 mRNA survived significantly longer than did the control groups. Immunohistochemical analysis revealed that greater numbers of T lymphocytes containing CD4+ and CD8+ T cells were found in the group vaccinated with dendritic cells transfected with Il13ra2 mRNA.

CONCLUSIONS

These results demonstrate the therapeutic potential of vaccination with dendritic cells transfected with Il13ra2 mRNA for the treatment of malignant glioma.

Continuous hypertension and tachycardia after resection of a hemangioblastoma behind the dorsal medulla oblongata: relationship to sympathetic overactivity at the neurogenic vasomotor center

A very rare case of continuous hypertension and tachycardia after excision of a cerebellar hemangioblastoma at the dorsal medulla oblongata is presented. This 21-year-old man was admitted to the authors' hospital with a headache and dizziness. Radiological examination revealed a tumor located behind the dorsal medulla oblongata and compressing it substantially. The tumor was completely resected, but after the surgery the patient experienced prolonged hypertension and tachycardia. Postoperative MR imaging showed a small injury at the dorsocaudal medulla that was located at the caudal site of the nucleus of the tractus solitarius (NTS). Because the NTS has been reported to play a central role in cardiovascular regulation along with the rostral ventrolateral medulla, the authors considered it possible that the NTS injury was the cause of the prolonged elevation of sympathetic tone.

Navigation-guided fence-post tube technique for resection of a brain tumor: technical note

INTRODUCTION

A new technique using a navigation system to minimize the influence of brain shift and to perform precise resection of brain tumors is demonstrated. To determine the resection plane, one to six tubes were inserted around the tumor under the guidance of a navigation system before dural incision.

RESULTS

This technique termed the "navigation-guided fence-post tube" (NGFP) procedure was used to treat 34 patients with intraaxial brain tumors including gliomas (23 cases), malignant lymphomas (4 cases) and metastatic tumors (7 cases). Tumors were removed totally in 23 cases (67.6%), subtotally (95% or more removal) in 6 cases (17.6%) and partially (less than 95% removal) in 5 cases (14.7%). The cases with subtotal or partial resection contained tumors that were close to or involved the eloquent area, or disseminated lesions. No complications due to tube insertion occurred.

CONCLUSION

NGFP is a useful and safe technique for brain tumor surgery with no influence of brain shift during tumor resection.

Benign fibrous histiocytoma of the skull with increased intracranial pressure caused by cerebral venous sinus occlusion

The authors present a very rare case of benign fibrous histiocytoma of the skull with increased intracranial pressure caused by sinus occlusion. A 33-year-old woman was referred for investigation of a right occipital protrusion with tenderness and double vision. She had only mild divergence insufficiency and bilateral papilledema neurologically. Imaging findings showed that the skull tumor was located at the right occipital bone with bone disruption and a compressed right sigmoid sinus. When planning the resection, caution was required to spare the collateral flow so as to manage the intracranial pressure. Immunohistochemical analysis showed that the tumor was positive for CD68, α1-antichymotrypsin, and α1-antitrypsin. From these findings, the tumor was diagnosed as a primary benign fibrous histiocytoma of the skull.

Immune or inflammatory response by the host brain suppresses neuronal differentiation of transplanted ES cell-derived neural precursor cells

Embryonic stem (ES) cells are a promising donor source for transplantation therapy, but several problems must be solved before they can be clinically useful. One of these is the host immune reaction to allogeneic grafts. In this article, we examine the effect of the host immune reaction on survival and differentiation of grafted ES cell-derived neural precursor cells (NPCs). We induced NPCs from mouse ES cells by stromal cell-derived inducing activity and then transplanted them into mouse brains with or without administering the immunosuppressant cyclosporine A (CsA). Two and 8 weeks following transplantation, the accumulation of host-derived microglia/macrophages and lymphocytes was observed around the graft. This effect was reduced by CsA treatment, although no significant difference in graft volume was observed. These data suggest that an immune response occurs in allografts of ES cell-derived NPCs. Intriguingly, however, the ratio of neurons to astrocytes in the graft was higher in immunosuppressed mice. Because inflammatory or immune cells produce various cytokines, we examined the effect of IL-1beta, IL-6, IFN-gamma, and TNF-alpha on the differentiation of NPCs in vitro. Only IL-6 promoted glial cell fate, and this effect could be reversed by the addition of an IL-6 neutralizing antibody. These results suggest that allogeneic ES cell-derived NPCs can cause an immune response by the host brain, but it is not strong enough to reject the graft. More important, activated microglia and lymphocytes can suppress neuronal differentiation of grafted NPCs in vivo by producing cytokines such as IL-6.

Association of intra- and extradural developmental venous anomalies, so-called venous angioma and sinus pericranii

INTRODUCTION

We report a case of cerebellar venous angioma and parietal sinus pericranii.

DISCUSSION

Venous angioma is classified as a developmental venous anomaly (DVA) because it is not a neoplasm but a variant that develops during embryogenesis. Sinus pericranii should be classified as extradural-type DVA. Although there have been few reports of association between these conditions, both are suspected to have the same pathogenesis, i.e., transient venous hypertension in the late embryonic period influencing venous development.

Generation of graftable dopaminergic neuron progenitors from mouse ES cells by a combination of coculture and neurosphere methods

Parkinson's disease is characterized by a loss of midbrain dopamine (DA) neurons and is generally viewed as a potential target for stem cell therapy. Although several studies have reported the generation of postmitotic DA neurons from embryonic stem (ES) cells, it is unknown whether the proliferative progenitors of DA neurons can be isolated in vitro. To investigate this possibility, we have developed a combined approach in which ES cells are cocultured with PA6 stromal cells to expose them to stromal cell-derived inducing activity (SDIA) and are then cultured as neurospheres. Mouse ES cell colonies were detached from PA6 feeder cells after 8 days of SDIA treatment and then expanded as spheres for another 4 days in serum-free medium supplemented with fibroblast growth factor-2. The spheres exhibited neural stem cell characteristics and contained few DA neurons at this stage of culture. After being induced to differentiate on polyornithine/laminin-coated dishes for 7 days, these spheres generated DA neurons in vitro at a relatively low frequency. Intriguingly, addition of PA6 cell conditioned medium to the sphere culture medium significantly increased the percentage of DA neurons to 25-30% of the total number of neurons. Transplantation of conditioned medium-treated day 4 spheres, which contained DA neuron progenitors, into the mouse striatum resulted in the generation of a significant number of graft-derived DA neurons. These findings suggest that progenitors of DA neurons are generated and can proliferate in ES cell-derived neurospheres induced by serial SDIA and PA6 conditioned medium treatment.

Dopaminergic neurons generated from monkey embryonic stem cells function in a Parkinson primate model

Parkinson disease (PD) is a neurodegenerative disorder characterized by loss of midbrain dopaminergic (DA) neurons. ES cells are currently the most promising donor cell source for cell-replacement therapy in PD. We previously described a strong neuralizing activity present on the surface of stromal cells, named stromal cell-derived inducing activity (SDIA). In this study, we generated neurospheres composed of neural progenitors from monkey ES cells, which are capable of producing large numbers of DA neurons. We demonstrated that FGF20, preferentially expressed in the substantia nigra, acts synergistically with FGF2 to increase the number of DA neurons in ES cell-derived neurospheres. We also analyzed the effect of transplantation of DA neurons generated from monkey ES cells into 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated (MPTP-treated) monkeys, a primate model for PD. Behavioral studies and functional imaging revealed that the transplanted cells functioned as DA neurons and attenuated MPTP-induced neurological symptoms.

Vaccine Therapy for Murine Glioma Using Tumor Cells Genetically Modified to Express B7.1

OBJECTIVE

In a syngeneic mouse brain tumor model, we tested the hypothesis that vaccination with tumor cells genetically modified to express B7.1 molecules induces tumor-specific T cells and immunological antitumor effects.

METHODS

Malignant glioma cells (RSV-MG) derived from a C3H/He mouse induced by Schmidt-Ruppin Rous sarcoma virus (RSV) were infected with an adenovirus encoding the B7.1 gene (AdB7). To investigate the effects of B7.1 expression on the tumorigenicity of RSV-MG cells, infected cells were implanted subcutaneously into C3H/He mice. The C3H/He mice were vaccinated with AdB7 transfectants injected subcutaneously and 2 weeks later were challenged intracerebrally with wild-type RSV-MG cells to determine whether or not the expression of B7.1 would enhance the immunogenicity of RSV-MG cells.

RESULTS

Immunocytochemistry confirmed the expression of B7.1 and major histocompatibility complex Class I antigen on the infected cells. The growth of subcutaneous tumors was markedly retarded in the AdB7 group, whereas tumors had formed and progressively increased in size in the other control groups. In the vaccine experiments, the mice immunized with AdB7 transfectants survived longer than did the mice of the other groups, and a significant difference in survival times was noted. Immunocytochemistry revealed that brain tumors in mice previously vaccinated with AdB7 infectants had been infiltrated by a larger number of CD3(+) lymphocytes and that these CD3(+) lymphocytes contained not only CD4(+) and CD8(+) T cells but also CD25(+)-activated T cells. In addition, a cytotoxicity assay confirmed that vaccination with the AdB7 transfectants induced tumor-specific cytotoxicity.

CONCLUSION

These results demonstrate the therapeutic potential of vaccination with tumor cells expressing B7.1 for the treatment of malignant glioma.

Ictal Onset and Spreading of Seizures of Parietal Lobe Origin

The characteristics of seizures associated with parietal lobe epilepsy were investigated in six consecutive patients with medically intractable epilepsy due to parietal lobe lesions. Intracranial electrode recordings were retrospectively reviewed to investigate the seizure onset symptoms and spreading patterns associated with the disorder. All six patients underwent implantation of subdural or depth electrodes and subsequent video/electroencephalography monitoring. Common symptoms included motionless stare, contralateral eye deviation, and head turn. Tonic posturing, contralateral sensory disturbance, and motor weakness were also seen. Asymmetrical generalized tonic and clonic seizures were seen in all six patients. All seizure activities began in the parietal lobe harboring the lesions, and then spread immediately to the adjacent lobes in most seizures, where the clinical symptoms were produced. The parietal lobe is a pure generator of seizures, whereas most clinical symptoms originate from adjacent lobes following seizure onset. No apparent specific symptoms other than sensory disturbance arising from the parietal lobe proper were recognized. Regardless of clinical symptoms, the seizure onset occurred in the parietal lobe harboring the lesion.

[A case of a ruptured dermoid cyst in the sylvian fissure]

A 22-year-old woman was admitted to our department after developing a headache. The neurological findings were unremarkable on her first visit, but CT demonstrated a lot of low-density masses in the subarachnoid space. The largest mass was in the right sylvian fissure. These lesions appeared hyper-intense in T1, T2 and diffusion-weighted MR images. A right frontotemporal craniotomy was performed to remove the main mass lesion in the right sylvian fissure. During surgery, thickening of the arachnoid membrane and floating oily globules were seen in the subarachnoid space. The histopathological examination revealed that the tumor was a dermoid cyst. Follow-up MRI revealed that some of the small lesions had moved since the operation. These findings suggested that the tumor was a ruptured dermoid cyst. The patient's postoperative course was uneventful and her headache disappeared completely.

Adenovirus-mediated gene transfer of B7.1 induces immunological anti-tumor effects in a murine brain tumor

The purpose of the present study was to determine if adenovirus-mediated transfection of a syngeneic mouse brain tumor with the gene encoding B7.1 enhances immunogenicity against tumor. Malignant astrocytoma cells were transfected with adenoviral vectors carrying the B7.1 gene (AdB7). Immunocytochemical analysis confirmed the expression of B7.1 in vitro and in vivo. To investigate the effects of B7.1 expression on tumorigenicity of the malignant astrocytoma, mice were implanted intracerebrally with B7.1-transfected glioma cells. There was no significant difference in proliferation between B7.1-transfected cells and controls in vitro. Nevertheless, mice implanted with B7. 1-transfected cells survived significantly longer than those in the control groups. Immunocytochemical analysis of the tumors showed that there was infiltration of a number of CD8+ T-cells and CD25+ activated T-cells in the brain implanted with B7.1-transfected glioma cells. The results showed the possibility that adenovirus-mediated B7.1 gene transfection to a brain tumor induced activation of CD8+ cytotoxic T-lymphocytes.

Surgical strategy for cavernous angioma in hypothalamus

A very rare case of cavernous angioma in the hypothalamus is presented. The patient was successfully treated by total excision of the haematoma and angioma, and there was no regrowth of the lesion on follow-up MRI. Complete excision of the angioma is the recommended surgical strategy even for patients with deep-seated lesions.

Co-administration of adenovirus vector expressing CTLA4-Ig prolongs transgene expression in the brain of mice sensitized with adenovirus

The duration of transgene expression in the brain is known to be shortened by previous sensitization to adenovirus. In order to prolong transgene expression, adenovirus vectors expressing CTLA4-Ig (AdCTLA), which blocks the B7-CD28 co-stimulatory signals required for T-cell activation, were used. Local administration of AdCTLA into the brain suppressed both the cellular and humoral immune responses to adenovirus vectors, and prolonged the duration of transgene expression. AdCTLA may be an effective tool for repeated gene transfer.

Microvascular decompression for cochlear symptoms

OBJECT

The object of this study was to evaluate the efficacy of a new neurovascular decompression technique in relieving symptoms of cochlear nerve dysfunction.

METHODS

Nineteen patients with slowly progressive hearing loss, low-frequency fluctuating hearing loss, and high-pitched tinnitus due to neurovascular compression (NVC) of the eighth cranial nerve in a triangular space between the seventh and eighth cranial nerves (the VII-VIII triangle) of the cerebellopontine angle (CPA) were treated using a new technique for microvascular decompression that was developed by anatomical study in 24 cadaver specimens of the CPA. In 12 of 19 patients the anterior inferior cerebellar artery (AICA) was observed to cause compression in the VII-VIII triangle and this vessel was easily mobilized medially for placement of a silicone sponge or Teflon cushion between the compressing artery and nerve. Postoperatively, hearing loss of 20 dB or more that was present in 11 of the 19 patients with NVC improved by more than 5 dB in seven (64%), including the patient with the most severe hearing loss. Of 18 patients presenting with tinnitus preoperatively, eight (44%) had no tinnitus and an additional nine (for a total of 94%) had good improvement in tinnitus after surgery and at long-term follow up.

CONCLUSIONS

The microvascular decompression technique described is highly successful in treating symptoms due to direct or indirect compression of the cochlear nerve, with minimal risk of complications. Recordings of auditory brainstem responses confirmed the clinical diagnosis of NVC of the eighth cranial nerve and correlated with clinical results after microvascular decompression of the cochlear nerve.

Immune gene therapy of experimental mouse brain tumor with adenovirus-mediated gene transfer of murine interleukin-4

We examined the antitumor activity of replication-deficient adenoviral vectors carrying the murine interleukin-4 (IL-4) gene (AdCIL4) using a syngeneic brain tumor model in mice. Mice implanted with malignant astrocytoma cells infected with AdCIL4 survived significantly longer than those in the control groups. Immunocytochemical analysis of the tumors showed that AdCIL4 caused the strong up-regulation of MHC class II antigen expression by the tumor cells and macrophages, and consequent infiltration by CD8+ T lymphocytes. This study demonstrates the efficacy of IL-4 gene transfection mediated by adenoviral vectors for intracerebral tumor and characterizes the immunoreaction caused by AdCIL4.

Local adenovirus-mediated CTLA4-immunoglobulin expression suppresses the immune responses to adenovirus vectors in the brain

The effect of local administration of two adenovirus vectors, one of which expressed CTLA4-immunoglobulin (AdCTLA), which blocks the B7-CD28 co-stimulatory pathway of T cell activation in the inflammatory response to adenovirus vectors was investigated. Mice injected with AdCTLA and an E1-deleted adenovirus vector that encodes the lacZ gene (AdRL) into the brain showed inflammatory cell infiltration from the early phase until day 6 after injection that was not different from that seen in control mice injected with an E1-deleted adenovirus vector containing no transgene (Ad0) and AdRL. After day 6 the inflammation in the control mice increased, peaked by day 15 and then decreased gradually but persisted until day 60. By contrast, in mice treated with AdCTLA and AdRL the inflammation, especially T cell infiltration, was suppressed after day 15. The anti-adenovirus antibody titer increased gradually until day 60 in the Ad0-AdRL control group, and whereas the mice injected with AdCTLA and AdRL showed lower anti-adenovirus antibody titers than the control group mice after day 15. Neutralizing antibody was not detected in either group. Expression of beta-galactosidase, the gene product of AdRL, at the injection site in the striatum and corpus callosum peaked on day 6 and remained until day 60 although it was very low in both groups; beta-galactosidase expression was similar in the two groups in spite of the difference in the degree and extent of the local immune response in the brain. This study demonstrated that the injection of an adenovirus vector expressing CTLA4-immunoglobulin into the brain suppressed not only local cell infiltration in the brain but also reduced the humoral immune response to adenovirus vectors.

[Diagnosis and treatment of nontraumatic dissecting aneurysm in the middle cerebral artery]

Two cases of nontraumatic dissecting aneurysm of the middle cerebral artery (MCA) are reported. A 59-year-old woman presented with subarachnoid hemorrhage, mainly in the right sylvian fissure. On admission, the right carotid angiogram revealed a dissecting aneurysm with a double lumen extending from segment M1 to M2 of the right MCA, and an unruptured saccular aneurysm in the right internal carotid artery. Emergency surgery revealed a discolored protrusion of the arterial wall in the right MCA, which was thought to be the cause of her subarachnoid hemorrhage. The protrusion of the arterial wall was clipped and coated with Bemsheet soaked in Biobond. However, disturbance of consciousness persisted and she died of paralytic ileus two months after the operation. The other patient was a hypertensive 33-year-old woman with right hemiparesis and motor dysphasia. CT scans obtained on the day of admission showed no abnormalities. She was treated conservatively with clinical improvement, but CT scans obtained 3 days after the ictus revealed an infarction deep in the left frontal lobe. A left carotid angiogram was made 4 days after ictus and demonstrated severe stenosis of the proximal segment of the left MCA with poor filling of its superior trunk. Despite improvement of her hemiparesis, CT scans obtained 3 weeks after the ictus showed hemorrhagic infarction in the left frontal lobe. Repeat left carotid angiogram revealed a double lumen in the C1 and M1 portions with improvement of the previous severe stenosis of the M1. The 23 reported cases of DA in the MCA with our cases are reviewed and their neuroradiological and clinical features are discussed.

Pilocytic astrocytoma of the velum interpositum

A 72-year-old male presented with a pilocytic astrocytoma in the velum interpositum manifesting as a 5-day history of dizziness attacks and unstable gait. Computed tomography and T1-weighted magnetic resonance imaging with gadolinium enhancement demonstrated a small, homogeneously enhanced mass in the velum interpositum. The tumor was removed subtotally, and the structure of the splenium was intact. The histological diagnosis was pilocytic astrocytoma. The MIB-1 growth fraction was 5%. The tumor may have originated from the splenium or the thalamus. The aggressive histology indicates the need for close neuroimaging follow-up.

A case of acute renal failure due to ethylene glycol intoxication

We describe an 18-year-old man with acute renal failure due to inadvertent ingestion of antifreeze that contained ethylene glycol (EG). A relatively small amount of EG was ingested, but nausea and vomiting were observed soon after ingestion. During admission to a local hospital, consciousness became impaired and generalized convulsion was noted. He was transferred to our hospital because of rapid deterioration of renal function. Emergency hemodialysis was begun. The patient underwent one treatment session of hemodialysis each day, for a total of 8 hemodialytic sessions before his renal function recovered. Examination of the renal biopsy specimen revealed degeneration of the renal tubular epithelium and presence of intratubular calcium oxalate crystals. The clinical features of the patient were mild except for acute renal failure. These findings suggest that even a small amount of EG will have toxic effects on the kidney.