A Case of Leptomeningeal Dissemination of Pilocytic Astrocytoma in a Child.

We present the case of a 2-year-old boy with progressive left-sided weakness and a cranial magnetic resonance imaging (MRI) scan showing a lesion with a cystic component in the right thalamus and basal ganglia. The lesion was subtotally resected and diagnosed as a pilocytic astrocytoma by histopathology. Tumor seeding along the surgical tract was seen on MRI 16 days and 10 weeks after surgery. The patient received vincristine and carboplatin, and MRI performed 4 months after chemotherapy revealed no additional or residual lesions. This case illustrated that a World Health Organization grade I astrocytoma could disseminate along the surgical tract.

Binding of HIV-1 gp120 to DC-SIGN promotes ASK-1-dependent activation-induced apoptosis of human dendritic cells.

During disease progression to AIDS, HIV-1 infected individuals become increasingly immunosuppressed and susceptible to opportunistic infections. It has also been demonstrated that multiple subsets of dendritic cells (DC), including DC-SIGN⁺ cells, become significantly depleted in the blood and lymphoid tissues of AIDS patients, which may contribute to the failure in initiating effective host immune responses. The mechanism for DC depletion, however, is unclear. It is also known that vast quantities of viral envelope protein gp120 are shed from maturing HIV-1 virions and form circulating immune complexes in the serum of HIV-1-infected individuals, but the pathological role of gp120 in HIV-1 pathogenesis remains elusive. Here we describe a previously unrecognized mechanism of DC death in chronic HIV-1 infection, in which ligation of DC-SIGN by gp120 sensitizes DC to undergo accelerated apoptosis in response to a variety of activation stimuli. The cultured monocyte-derived DC and also freshly-isolated DC-SIGN⁺ blood DC that were exposed to either cross-linked recombinant gp120 or immune-complex gp120 in HIV⁺ serum underwent considerable apoptosis after CD40 ligation or exposure to bacterial lipopolysaccharide (LPS) or pro-inflammatory cytokines such as TNFα and IL-1ß. Furthermore, circulating DC-SIGN⁺ DC that were isolated directly from HIV-1⁺ individuals had actually been pre-sensitized by serum gp120 for activation-induced exorbitant apoptosis. In all cases the DC apoptosis was substantially inhibited by DC-SIGN blockade. Finally, we showed that accelerated DC apoptosis was a direct consequence of excessive activation of the pro-apoptotic molecule ASK-1 and transfection of siRNA against ASK-1 significantly prevented the activation-induced excessive DC death. Our study discloses a previously unknown mechanism of immune modulation by envelope protein gp120, provides new insights into HIV immunopathogenesis, and suggests potential therapeutic approaches to prevent DC depletion in chronic HIV infection.

Toona sinensis leaf extract has antinociceptive effect comparable with non-steroidal anti-inflammatory agents in mouse writhing test.

BACKGROUND: The antinociceptive effect of an aqueous extract from the leaves of Toona sinensis (TS, [A. Juss., M. Roem.]) was studied using the writhing test in mice. METHODS: Different extraction fractions from TS leaf extracts (TSL1 to TSL5) were administered orally 1 h before intraperitoneal injection of acetic acid. RESULTS: After treatment with TSL1, TSL2, TSL3, TSL4, and TSL5 at a dose of 1 g/kg, the respective writhing responses were 39.9% (P < 0.001), 19.9% (P < 0.05), 11.7% (P = 0.052), 8.1% (P = 0.188), and 11.4% (P = 0.057) lower than the control group. Mice treated with TSL1 at 1 g/kg (39.9%, P < 0.001), 0.3 g/kg (38.0%, P < 0.001), 0.1 g/kg (46.9%, P < 0.001), and 0.03 g/kg (31.1%, P < 0.001) had significantly lower writhing responses compared with control mice. A time-course experiment was performed, which involved oral administration of TSL1 (0.1 g/kg) at 0, 0.5, 1, 2, and 6 h before acetic acid intraperitoneal injection. The most effective dose of TSL1 was 0.1 g/kg orally, with the effect beginning 30 min before treatment and persisting until 6 h. CONCLUSIONS: This study showed that TS has anti-visceral pain properties comparable with those of rofecoxib (a cyclooxygenase-2 inhibitor) and diclofenac, which suggests promise for the treatment of intractable visceral pain in humans.

Plasma levels of transforming growth factor-beta 1 before and after removal of low- and high-grade astrocytomas.

Transforming growth factor-beta 1 (TGF-ß1) has been reported to be a possible marker for a number of tumors, including brain tumors. The aim of this study was to measure the plasma levels of TGF-ß1 in patients with low- and high-grade astrocytomas before and after surgery. This prospective study included 14 patients with low-grade astrocytomas and 25 with high-grade astrocytomas who underwent tumor removal and 13 controls (patients who underwent cranioplasty for skull bone defects). Plasma levels of TGF-ß1 were measured in all subjects using enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) curve analysis showed that when the level of TGF-ß1 before tumor removal was ≥ 2.52 ng/ml, astrocytoma was predicted with a sensitivity of 94.9% and specificity of 100%. The mean plasma level of TGF-ß1 in both the low-grade and high-grade astrocytoma groups significantly decreased after tumor removal (p<0.05); there was no significant change in TGF-ß1 plasma level of the controls following surgery. Patients with high-grade astrocytomas had a significantly higher mortality rate than patients with low-grade astrocytomas (p=0.019) and significantly shorter survival (p=0.008). A positive correlation between TGF-ß1 level after tumor removal and tumor volume was only found in the high-grade astrocytoma group (γ=0.597, p=0.002). The findings show that plasma TGF-ß1 level was increased in patients with low-grade and high-grade astrocytoma, and that the levels significantly decreased after tumor removal in both groups. The results provide additional evidence that TGF-ß1 might be useful as a tumor marker for astrocytomas.

17ß-Estradiol attenuates secondary injury through activation of Akt signaling via estrogen receptor alpha in rat brain following subarachnoid hemorrhage.

BACKGROUND: Apoptosis is implicated in vasospasm and the long-term sequelae of subarachnoid hemorrhage (SAH). This study tested the hypothesis that attenuation of SAH-induced apoptosis after 17ß-estradiol (E2) treatment is associated with an increase in phosphorylation of Akt via estrogen receptor-α (ER-α) in rats. MATERIALS AND METHODS: We examined the expression of phospho-Akt, ERα and ERß, and apoptosis in cerebral cortex, hippocampus, and dentate gyrus in a two-hemorrhage SAH model in rats. We subcutaneously implanted other rats with a silicone rubber tube containing E2; they received daily injections of nonselective estrogen receptor antagonist (ICI 182,780), selective ERα-selective antagonist (methyl-piperidino-pyrazole), or ERß-selective antagonist (R,R-tetrahydrochrysene) after the first hemorrhage. RESULTS: At 7 d after the first SAH, protein levels of phospho-Akt and ERα were significantly decreased and caspase-3 was significantly increased in the dentate gyrus. The cell death assay revealed that DNA fragmentation was significantly increased in the dentate gyrus. Those actions were reversed by E2 and blocked by ICI 182,780 and methyl-piperidino-pyrazole, but not R,R-tetrahydrochrysene. However, there were no significant changes in the expression of the protein levels of phospho-Akt, ERα, ERß, and caspase-3, and DNA fragmentation after SAH. CONCLUSIONS: The present study shows that a beneficial effect of E2 in attenuating SAH-induced apoptosis is associated with activation of the expression of phospho-Akt and ERα, and alteration in caspase-3 protein expression via an ERα-dependent mechanism in the dentate gyrus. These data support further the investigation of E2 in the treatment of SAH in humans.

Measurement precision of the disability for back pain scale-by applying Rasch analysis.

BACKGROUND: The Oswestry Disability Index (ODI) is widely used for patients with back pain. However, few studies have examined its psychometric properties using modern measurement theory. The purpose of this study was to investigate the psychometric properties of the ODI in patients with back pain using Rasch analysis. METHODS: A total of 408 patients with back pain participated in this cross-sectional study. Patients were recruited from the orthopedic, neurosurgery, rehabilitation departments and pain clinic of two hospitals. Rasch analysis was used to examine the Chinese version of ODI 2.1 for unidimensionality, item difficulty, category function, differential item functioning, and test information. RESULTS: The fit statistics showed 10 items of the ODI fitted the model's expectation as a unidimensional scale. The ODI measured the different levels of functional limitation without skewing toward the lower or higher levels of disability. No significant ceiling and floor effects and gaps among the items were found. The reliability was high and the test information curve demonstrated precise dysfunction estimation. CONCLUSIONS: Our results showed that the ODI is a unidimensional questionnaire with high reliability. The ODI can precisely estimate the level of dysfunction, and the item difficulty of the ODI matches the person ability. For clinical application, using logits scores could precisely represent the disability level, and using the item difficulty could help clinicians design progressive programs for patients with back pain.

Arrested growth and spontaneous tumor regression of partially resected low-grade cerebellar astrocytomas in children.

PURPOSE: The prognosis of children with low-grade cerebellar astrocytoma who have partial resection of tumor is largely unpredictable. The purpose of this study was to review the long-term outcome of such patients. METHODS: The medical charts, imaging findings, operative notes, histopathological reports, and survival times of 12 patients with cerebellar astrocytoma were reviewed. RESULTS: Five patients had total resection and seven had partial resection. Nine patients had grade I histology and three patients had grade II. Follow-up duration ranged from 3 to 25 years. Among the seven patients with residual tumor, five had tumor progression, one had arrested tumor growth, and one had spontaneous tumor regression. Five patients with partial resection received radiotherapy and three had malignant transformation of tumor during follow-up. Six patients, including five who had partial resection, underwent a second operation. One patient with partial resection died of pneumonia 23 years after surgery. CONCLUSIONS: Patients with complete tumor resection had a better prognosis than patients with partial resection. For patients with partial resection, we recommend a "wait and see" policy with surveillance using MRI. The phenomenon of arrested tumor growth and spontaneous tumor regression in patients with cerebellar astrocytoma who have subtotal resection warrants further study.

Purine anti-metabolite attenuates nuclear factor κB and related pro-inflammatory cytokines in experimental vasospasm.

BACKGROUND: Increased nuclear factor κB (NF-κB) bioexpression, as well as TNF-α, IL-1ß and IL-6 levels, were observed after aneurysmal subarachnoid hemorrhage (SAH). It is of interest to investigate the effect of 6-mercaptopurine (6-mp) on cytokines/NF-κB in this SAH model. MATERIALS AND METHODS: A rodent double-hemorrhage SAH model was employed. Serum and cerebrospinal fluid (CSF) samples were collected to examine IL-1, IL-6 and TNF-α levels. NF-κB subunit p65 and its inhibitor of nuclear factor κB (IκB) were examined (by Western blot). TNF-α was used to induce the phosphorylation of IκB in the presence or absence of 6-mp. RESULTS: Nuclear NF-κB subunit p65/IκB kinase in the basilar artery was over-expressed, and cytokines was notably increased in the SAH groups, compared with the controls (P < 0.01). In the 6-mp SAH group, obvious reduction was observed in NF-κB subunit p65 (nuclei) (P < 0.01). Treatment with 6-mp significantly reduced IL-1ß and TNF-α levels to those of the healthy control. 6-Mercaptopurine also significantly increased the level of IκB in the TNF-α-stimulated SAH rats. CONCLUSIONS: Through inhibiting IκB bioexpression, 6-mp decreases NF-κB-related IL-1ß, IL-6, and TNF-α in the presence of SAH. The study suggests 6-mp exerts vascular anti-inflammatory properties through inhibiting IκB kinase and subsequently blocks bio-activation of NF-κB and related cytokines, which may contribute to its antivasospastic effect in animals subjected to SAH.

Potential Roles of Teamwork and Unmet Needs on Surgical Learning Curves of Spinal Robotic Screw Placement.

Background: The aim of this study was to investigate the learning curve of robotic spine surgery quantitatively with the well-described power law of practice. Methods: Kaohsiung Medical University Hospital set up a robotic spine surgery team by the neurosurgery department in 2013 and the orthopedic department joined the well-established team in 2014. A total of consecutive 150 cases received robotic assisted spinal surgery. The 150 cases, with 841 transpedicular screws were enrolled into 3 groups: the first 50 cases performed by neurosurgeons, the first 50 cases by orthopedic surgeons, and 50 cases by neurosurgeons after the orthopedic surgeons joined the team. The time per screw and accuracy by each group and individual surgeon were analyzed. Results: The time per screw for each group was 9.56 ± 4.19, 7.29 ± 3.64, and 8.74 ± 5.77 minutes, respectively, with p-value 0.0017. The accuracy was 99.6% (253/254), 99.5% (361/363), and 99.1% (222/224), respectively, with p-value 0.77. Though the first group took time significantly more on per screw placement but without significance on the nonlinear parallelism F-test. Analysis of 5 surgeons and their first 10 cases of short segment surgery showed the time per screw by each surgeon was 12.28 ± 5.21, 6.38 ± 1.54, 8.68 ± 3.10, 6.33 ± 1.90, and 6.73 ± 1.81 minutes. The first surgeon who initiated the robotic spine surgery took significantly more time per screw, and the nonlinear parallelism test also revealed only the first surgeon had a steeper learning curve. Conclusion: This is the first study to demonstrate that differences of learning curves between individual surgeons and teams. The roles of teamwork and the unmet needs due to lack of active perception are discussed.

6-Mercaptopurine reverses experimental vasospasm and alleviates the production of endothelins in NO-independent mechanism-a laboratory study.

INTRODUCTION: Increased endothelin-1 (ET-1) production and diminished nitric oxide synthase (NOS) bioavailability has been observed in aneurysmal subarachnoid hemorrhage (SAH). The authors previously found that 6-mercaptopurine (6-mp) is effective in preventing and reversing arterial narrowing in a rodent SAH model. This present study is of interest to examine the effect of 6-mp on ET-1/endothelial nitric oxide synthase (eNOS) in this animal model. METHODS: A rodent double hemorrhage SAH model was employed. Animals were randomly assigned to six groups (sham, SAH only, vehicle, 0.5, 1.0 and 2 mg kg(-1) day(-1) 6-mp treatment). Monoclonal CD45 immunostaining was utilized to evaluate monocytes and microglia. The level of pro-inflammatory cytokines, such as IL-1, IL-6 and TNF-α(RT-PCR), and ET-1 (ELISA) was measured. The basilar arteries (BAs) were harvested and sliced, and their cross-sectional areas were determined. Radiolabeled NOS assay kit was applied to detect eNOS. RESULTS: Morphologically, convolution of internal elastic lamina, endothelial cells distortion, and necrotic smooth muscle were prevalently present in the basilar artery of SAH groups, which was absent in the 1 and 2 mg kg(-1) day(-1) 6-mp plus SAH group or the healthy controls. Significant vasospasm was noted in the vehicle group (lumen patency, 54.6%, p ≤ 0.01 compared with the sham group), but it was less prominent in the 2 mg kg(-1) day(-1) 6-mp treatment group (lumen patency, 87.6%, p < 0.05). In addition, administration with 2 mg kg(-1) day(-1) 6-mp reduced cytokine levels by 11%, 47%, and 34% for IL-1, IL-6, and TNF-α, respectively, and increased ET-1 levels were found in all the animals subject to SAH (SAH only, SAH plus vehicle, SAH plus 0.5 and 1.0 mg kg(-1) day(-1) 6-mp) except in the 2 mg kg(-1) day(-1) 6-mp SAH group, when compared with the healthy controls (no SAH). Meanwhile, treatment with 6-mp did not induce the levels of expressed eNOS in BAs in the 6-mp groups (0.5, 1.0, and 2 mg kg(-1) day(-1) 6-mp plus SAH) when compared with that in the SAH groups (p > 0.1). CONCLUSION: In summary, treatment with 6-mp decreased the release of pro-inflammatory cytokines and diminished experimental vasospasm. This study offered first evidence that 6-mp dose-dependently reduces the level of ET-1 in a NO-independent mechanism, which corresponds to its antivasospastic effect in the condition of chronic vasospasm.

Functional outcome analysis: instrumented posterior lumbar interbody fusion for degenerative lumbar scoliosis.

PURPOSE: Although instrumented posterior lumbar interbody fusion (PLIF) has been becoming a popular and effective method for treating degenerative lumbar scoliosis, the clinical outcome is rarely reported. We retrospectively evaluated the clinical and radiographic outcomes in patients with degenerative lumbar scoliosis after instrumented PLIF. MATERIALS AND METHODS: A total of 58 patient's clinical characteristics had been reviewed retrospectively including clinical presentations, preoperative medical comorbidities, intraoperative status, and postoperative status. Oswestry disability index (ODI), visual analog scale (VAS), and patient satisfaction were evaluated before surgery and last follow-up period. The relationship between the difference of radiographic parameter and functional outcome was evaluated. RESULTS: Functional outcomes including ODI scores and VAS were significantly improved at the last visit. The ODI was 28.1 ± 8.0 before surgery and 12.2 ± 8.8 at the last visit. VAS was 7.4 ± 2.0 before surgery and 2.4 ± 2.0 at the last visit. Patient satisfaction was 72% at the last visit. ODI was significantly related to postoperative radiographic parameters including Cobb's angle (p < 0.001), L4 inclination (p = 0.011), coronal balance (p = 0.007), lateral vertebral translation (p < 0.001), Nash-Moe grade (p = 0.033), Nash-Moe degree (p = 0.025), and sagittal balance (p = 0.041) Using multiple regression analysis, ODI was significantly related to female gender, number of levels fixed, coronal balance, lateral vertebral translation, and Nash-Moe degree. The was no significant correlation between postoperative radiographic parameters and pain (VAS). Only lateral vertebral translation demonstrated a significant correlation in multiple regression analysis. CONCLUSIONS: Based on the VAS and ODI instrument, our studies demonstrated that instrumented PLIF for adult degenerative lumbar scoliosis can achieve a high rate of patient satisfaction and improvement in radiographic and clinical outcomes at a minimum of 2 years of follow-up.

A comparative study of the patients with bilateral or unilateral chronic subdural hematoma: precipitating factors and postoperative outcomes.

BACKGROUND: : Chronic subdural hematoma (CSDH) is a relatively frequent problem in neurologic or neurosurgical practice. Although CSDH is a well-known disease, data on bilateral CSDH are scarce compared with data on unilateral CSDH. The purpose of this study was to compare the clinical presentations, precipitating factors, computed tomography (CT) scan findings, postoperative complications, and outcomes between patients with bilateral and unilateral CSDH. METHODS: : A retrospective study was performed on 129 surgical patients with CSDH from January 2002 to January 2005. These patients were divided into two groups: bilateral CSDH (45 cases) and unilateral CSDH (84 cases). Clinical presentations, precipitating factors, CT scan findings, postoperative complications, and outcomes of patients were analyzed. RESULTS: : The mean age was 75 years for patients with bilateral CSDH and was 68 years for patients with unilateral CSDH (p = 0.696). Males predominated in each group (p = 0.696). The frequency of presenting symptoms of nausea and vomiting, headache, or unsteady gait was significantly greater in bilateral CSDH than in unilateral CSDH (p < 0.05). The incidence of usage of anticoagulant and antiplatelet therapy was significantly higher in bilateral CSDH group than in unilateral CSDH group (p < 0.05). The frequency of marked midline shift on CT scans was significantly greater in unilateral CSDH than in bilateral CSDH (p < 0.05). Coexisting systemic diseases, postoperative complications, and outcomes had no significant differences between both groups. CONCLUSIONS: : Bilateral CSDH tended to occur more in patients with anticoagulant or antiplatelet therapy. Compared with patients with unilateral CSDH, patients with bilateral CSDH had more symptoms of increased intracranial pressure and lower incidences of midline shift on CT scans. Most patients with either bilateral or unilateral CSDH had a good postoperative outcome.

Atorvastatin preconditioning attenuates the production of endothelin-1 and prevents experimental vasospasm in rats.

OBJECTIVE: Induced endothelin-1 (ET-1) production and decreased nitric oxide synthase (NOS) bioavailability have been found in aneurysmal subarachnoid hemorrhage (SAH). Atorvastatin is recognized to have pleiotropic effects including increasing NOS bioavailability as well as reducing inflammation and oxidative damage other than reducing dyslipidemia. This study is of interest to examine the effect of atorvastatin on ET-1/endothelial nitric oxide synthase (eNOS) in experimental SAH. METHODS: A rodent double-hemorrhage SAH model was employed. Animals were randomly assigned as sham-operated, SAH, vehicle plus SAH, 5 mg/day atorvastatin treatment plus SAH and 5 mg/day atorvastatin precondition plus SAH groups. Administration with atorvastatin (5 mg/day) was initiated 1 week before (precondition) and 24 hr later (treatment). Cerebrospinal fluid samples were collected at 72 hr after second SAH. ET-1 (ELISA) was measured. The basilar arteries (BAs) were harvested and sliced, and their cross-sectional areas were measured. Radiolabeled NOS assay kit was used to detect eNOS. RESULTS: Morphologically, convoluted internal elastic lamina, distorted endothelial cells and myonecrosis of the smooth muscle were predominantly observed in the BA of SAH and vehicle-treated SAH groups, which was not detected in the atorvastatin-preconditioned SAH group or the healthy controls. Significant vasospasm was noted in the vehicle group (lumen potency 64.5%, compared with the sham group, p

Active extracts of wild fruiting bodies of Antrodia camphorata (EEAC) induce leukemia HL 60 cells apoptosis partially through histone hypoacetylation and synergistically promote anticancer effect of trichostatin A.

The endemic species of Antrodia camphorate (AC) is a promising chemotherapeutic drug for cancer. We found that the ethanol extract from wild fruiting bodies of Antrodia camphorata (EEAC) could induce HL 60 cells apoptosis via histone hypoacetylation, up-regulation of histone deacetyltransferase 1 (HDAC 1), and down-regulation of histone acetyltransferase activities including GCN 5, CBP and PCAF in dose-dependent manner. In combination with histone deacetylase inhibitor, trichostatin A (TSA), did not block EEAC-induced apoptosis. Interestingly, combined treatment (100 nM of TSA and 100 microg/ml EEAC) caused synergistic inhibition of cell growth and increase of apoptotic induction. EEAC could effectively increase the cytotoxic sensitivity of TSA through the up-regulation of DR5 and NFkappaB activation. In this present study, bioassay-guided fractionation of EEAC led to a major active compound, zhankuic acid A, as the bioactive marker. Moreover, our findings may represent an experimental basis for developing EEAC as a potential chemotherapeutic adjuvant.

The outcome of percutaneous computed tomography-guided chemical lumbar sympathectomy for patients with causalgia after lumbar discectomy.

BACKGROUND: Coldness, numbness, or causalgia usually affects the lower limbs in patients after back surgeries. The treatment of causalgia is still the source of continuing debate. We treated patients presenting with causalgia secondary to LD with CT-guided CLS and determined the therapeutic outcome at long-term follow-up. METHODS: From January 2002 to December 2002, a total of 15 patients (16 limbs) with causalgia after LD underwent the percutaneous CT-guided CLS. There were 7 male patients and 8 female patients, with an average age of 49.1 years. A total of 14 patients underwent unilateral procedures, and 1 patient underwent staged bilateral procedures. We followed up our patients for at least 24 months (24-36 months). RESULTS: There were 13 patients (14 limbs) diagnosed as Drucker stage I and 2 patients as stage II. There were 88% (14 limbs) that had an early satisfactory outcome after CLS and 75% (12 limbs) that had a late satisfactory outcome (more than 24 months after CLS). Stage I patients had more satisfying early and late outcome than stage II patients (P= .014 and P= .039, respectively). Female patients were more likely to have satisfactory late outcome than male patients (P= .034). There was no operative mortality. A patient had a complication of genitofemoral neuralgia, which had recovered in a month. CONCLUSIONS: We concluded that the percutaneous CT-guided CLS is an easy, safe, and reproducible technique, and it carries long-term benefit to patients with pain after LD presenting with causalgia, especially for patients with Drucker stage I and female patients.

The expression of thyroid hormone receptor isoforms in human astrocytomas.

BACKGROUND: Thyroid hormone plays a major role in normal mammalian brain maturation and affects the development of astrocytes. The expression of TR isoforms has been studied in different neoplasias. Increasing evidence has suggested that aberrant expression of TR isoforms could be associated with tumorigenesis. However, little was studied about the expression of TR isoforms in human astrocytomas. METHODS: In this study, RT-PCR was used to examine the expression of human TR isoforms in 34 human astrocytoma samples. RESULTS: We compared the TR expression between low grade (WHO grade II) and high grade (WHO grade III and IV). The frequency of TRalpha1 or TRalpha2 expression significantly decreased with the grade of malignancy (P=.005 and P=.043, respectively). However, the frequency of TRbeta1 expression significantly increased with the grades of malignancy astrocytomas (P=.017). CONCLUSIONS: Our study demonstrated for the first time that TR isoforms are indeed expressed in human astrocytomas. The expression of TR isoforms is correlated to the malignancy grading of astrocytomas. Our result provides insight into the potential use of hormonal therapy for brain tumors that overexpress or underexpress TRs.

Giant invasive schwannoma of cauda equina with minimal neurologic deficit: a case report and literature review.

A 53-year-old man presented with a history of slight weakness in the right lower limb. Giant invasive cauda equina schwannoma was diagnosed according to the criteria of Sridhar et al. Schwannomas are usually benign and common tumors arising from nerve sheath cells, particularly from sensory nerves. Giant invasive schwannomas, however, are rare, and most of patients with them present with severe neurologic deficits independent of daily activity, although in the case presented here, in spite of the large size of the tumor causing pedicle erosion, expansive destruction of the vertebral body and widening of the neural foramina, there were only minimal neurologic deficits. We have therefore decided to report this case, with a review of the relevant English literature emphasizing clinical presentations, plain film images and magnetic resonance image findings of giant invasive cauda equina schwannoma for early diagnosis and differential diagnosis.

Low-grade astrocytoma associated with abscess formation: case report and literature review.

A rare case of low-grade astrocytoma associated with abscess formation occurred in a 52-year-old man presenting with Broca's aphasia. He underwent craniotomy and tumor removal under the impression of brain tumor with necrotic cystic change. Abscess accumulation within the intra-axial tumor was found intraoperatively. Literature related to brain abscess with brain tumor is reviewed, with an emphasis on abscesses with astrocytoma. We discuss the common brain tumors that are associated with abscess, pathogens that coexist with brain tumor, and the pathogeneses of coexisting brain abscess and tumor. It is very important to know how to differentiate between and diagnose a brain abscess and tumor, or brain abscess with tumor, preoperatively from clinical presentation and through the use of computed tomography, conventional magnetic resonance imaging, diffusion-weighted imaging or magnetic resonance spectroscopy.