Quasicrystal as a Catalyst for the Synthesis of Carbon Nanotubes

The present report describes the catalytic activity of mechanically activated nano quasicrystalline Al65Cu20Fe15 and related nano crystalline Al50Cu28Fe22 for the synthesis of carbon nanotubes (CNTs). CNTs are synthesized by catalytic decomposition of ethanol through nano quasicrystalline Al65Cu20Fe15 and related crystalline Al50Cu28Fe22 alloys as a catalyst. The synthesized multi-walled CNTs exhibits tube diameter ranging from 5 to 25 nm. The synthesized CNTs are characterized by scanning and transmission electron microscopy. It is found that Al65Cu20Fe15 nanoquasicystal shows better catalytic behaviour as compared to nano-crystalline Al50Cu28Fe22 alloys for decomposition of ethanol during the synthesis of multi-walled CNTs.

Characteristics of intraoperative abnormal hemodynamics during resection of an intra-fourth ventricular tumor located on the dorsal medulla oblongata

Abnormal hemodynamics during extirpation of a para-medulla oblongata (MO) tumor is common and may be associated with direct vagal stimulation of the medullary circuit. However, resection of tumors on the dorsal MO may also induce hemodynamic instability without direct vagal stimulus. The objective of this study was to examine the characteristics of hemodynamic instability unrelated to vagal stimulus during dissection of an intra-fourth ventricular tumor with attachment to the dorsal MO. A retrospective analysis was performed in 13 patients. Abnormal hemodynamics were defined as a > 20% change from the means of the intraoperative mean arterial pressure (MAP) and heart rate (HR). Relationships of intraoperative hemodynamics were evaluated with various parameters, including the volume of the MO. Six patients (46.2%) had intraoperative hypertension during separation of the tumor bulk from the dorsal MO. The maximum MAP and HR in these patients were significantly greater than those in patients with normal hemodynamics (116.0 ± 18.0 mmHg versus 85.6 ± 6.5 mmHg; 124.3 ± 22.8 bpm versus 90.5 ± 14.7 bpm). All six cases with abnormal hemodynamics showed hemodynamic fluctuation during separation of the tumor bulk from the dorsal MO. The preoperative volume of the MO in these patients was 1.11 cc less than that in patients with normal hemodynamics, but the volume after tumor resection was similar in the two groups (5.23 cc and 5.12 cc). This suggests that the MO was compressed by the conglutinate tumor bulk, with resultant fluctuation of hemodynamics. Recognition of and preparation for this phenomenon are important for surgery on a tumor located on the dorsal MO.

Cortical region-specific engraftment of embryonic stem cell-derived neural progenitor cells restores axonal sprouting to a subcortical target and achieves motor functional recovery in a mouse model of neonatal hypoxic-ischemic brain injury

Hypoxic-ischemic encephalopathy (HIE) at birth could cause cerebral palsy (CP), mental retardation, and epilepsy, which last throughout the individual's lifetime. However, few restorative treatments for ischemic tissue are currently available. Cell replacement therapy offers the potential to rescue brain damage caused by HI and to restore motor function. In the present study, we evaluated the ability of embryonic stem cell-derived neural progenitor cells (ES-NPCs) to become cortical deep layer neurons, to restore the neural network, and to repair brain damage in an HIE mouse model. ES cells stably expressing the reporter gene GFP are induced to a neural precursor state by stromal cell co-culture. Forty-hours after the induction of HIE, animals were grafted with ES-NPCs targeting the deep layer of the motor cortex in the ischemic brain. Motor function was evaluated 3 weeks after transplantation. Immunohistochemistry and neuroanatomical tracing with GFP were used to analyze neuronal differentiation and axonal sprouting. ES-NPCs could differentiate to cortical neurons with pyramidal morphology and expressed the deep layer-specific marker, Ctip2. The graft showed good survival and an appropriate innervation pattern via axonal sprouting from engrafted cells in the ischemic brain. The motor functions of the transplanted HIE mice also improved significantly compared to the sham-transplanted group. These findings suggest that cortical region specific engraftment of preconditioned cortical precursor cells could support motor functional recovery in the HIE model. It is not clear whether this is a direct effect of the engrafted cells or due to neurotrophic factors produced by these cells. These results suggest that cortical region-specific NPC engraftment is a promising therapeutic approach for brain repair.

Stereotactic radiosurgery/radiotherapy for pituitary adenomas: a review of recent literature

The recent clinical results are reviewed of stereotactic radiosurgery/radiotherapy for the treatment of pituitary adenomas. The outcomes of pituitary adenomas treated by stereotactic radiosurgery/radiotherapy with gamma knife, CyberKnife, or linear accelerator (LINAC) radiosurgery were evaluated from articles published after 2004. Each study was evaluated for the number of patients, radiosurgical parameter (marginal dose), length of follow up, tumor growth control, rate of hormonal normalization in secretary adenomas, and adverse events. After gamma knife radiosurgery, the tumor reduction rates varied from 42.3% to 89% in non-secreting adenomas. However, the tumor control rates in non-secreting adenomas were more than 90% in most studies. In growth hormone-secreting adenomas, the rates of insulin-like growth factor-1 normalization ranged from 36.9% to 82%. In adrenocorticotropin-secreting adenomas, the rates for 24-hour urine free cortisol normalization ranged from 27.9% to 54%. In prolactin-secreting adenomas, the prolactin normalization ranged from 17.4% to 50%. New hormonal deficits ranged from 0% to 34%. New visual deficits were relatively low. The number of patients treated with CyberKnife and LINAC radiosurgery/radiotherapy was small and follow-up periods were relatively short compared to those with gamma knife treatment, but the clinical outcomes after these therapies were similar to those after gamma knife therapy. Image-guided stereotactic radiosurgery/radiotherapy with the gamma knife, CyberKnife, or LINAC system is effective and safe against pituitary adenomas. Careful long-term follow up of the patients is necessary because of long-term anti-tumor effects and delayed adverse events.

Progression of stenosis into occlusion of the distal posterior cerebral artery supplying an occipital arteriovenous malformation manifesting as multiple ischemic attacks: case report

A 31-year-old healthy male presented with a rare case of cerebral arteriovenous malformation (AVM) manifesting as repeated ischemic attacks and cerebral infarction causing left sensori-motor disturbance. Neuroimaging revealed cerebral infarction in the right thalamus as well as right occipital AVM without bleeding. The AVM was mainly fed by the right angular artery, and the right posterior cerebral artery (PCA) showed mild stenosis and segmental dilation at the P(2)-P(3) portion. After referral to our hospital, transient ischemic attacks causing left homonymous hemianopsia, and left arm and leg numbness were frequently recognized. Additional imaging revealed a new ischemic lesion in the occipital lobe, and repeated cerebral angiography showed right PCA occlusion at the P(2)-P(3) segment. Cerebral AVM presenting with cerebral infarction due to occlusion of feeding arteries is rare. In our case, intimal injury due to increased blood flow or spontaneous dissection of the artery were possible causes. We should monitor any changes in the architecture and rheology of the feeding vessels during the clinical course to prevent ischemic complications.

Gene expression signature-based prognostic risk score in patients with primary central nervous system lymphoma

PURPOSE

Better understanding of the underlying biology of primary central nervous system lymphomas (PCNSL) is critical for the development of early detection strategies, molecular markers, and new therapeutics. This study aimed to define genes associated with survival of patients with PCNSL.

EXPERIMENTAL DESIGN

Expression profiling was conducted on 32 PCNSLs. A gene classifier was developed using the random survival forests model. On the basis of this, prognosis prediction score (PPS) using immunohistochemical analysis is also developed and validated in another data set with 43 PCNSLs.

RESULTS

We identified 23 genes in which expressions were strongly and consistently related to patient survival. A PPS was developed for overall survival (OS) using a univariate Cox model. Survival analyses using the selected 23-gene classifiers revealed a prognostic value for high-dose methotrexate (HD-MTX) and HD-MTX-containing polychemotherapy regimen-treated patients. Patients predicted to have good outcomes by the PPS showed significantly longer survival than those with poor predicted outcomes (P < 0.0001). PPS using immunohistochemical analysis is also significant in test (P = 0.0004) and validation data set (P = 0.0281). The gene-based predictor was an independent prognostic factor in a multivariate model that included clinical risk stratification (P < 0.0001). Among the genes, BRCA1 protein expressions were most strongly associated with patient survival.

CONCLUSION

We have identified gene expression signatures that can accurately predict survival in patients with PCNSL. These predictive genes should be useful as molecular biomarkers and they could provide novel targets for therapeutic interventions.

Case of anti-glomerular basement membrane antibody-induced glomerulonephritis with cytomegalovirus-induced thrombotic microangiopathy

Although the involvement of cytomegalovirus (CMV) infections in the development of thrombotic microangiopathy (TMA) in HIV patients and transplant recipients has been reported, it is still controversial whether CMV itself can cause TMA. We report herein a rare case with rapid improvement of TMA by ganciclovir treatment in a patient who is neither HIV-positive nor a transplant recipient, suggesting a pathogenic role for CMV in TMA.

M2 macrophage/microglial cells induce activation of Stat3 in primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is one of the most aggressive malignant lymphomas with a median survival of less than 20~40 months. Interest in signal transducer and activator of transcription 3 (Stat3) has increased during the past decade because Stat3 activation was found to contribute to tumor progression by inducing angiogenesis, immunosuppression, and metastasis. We previously demonstrated a significant correlation between Stat3 activation in tumor cells and infiltrating anti-inflammatory (M2) macrophages. Here, we focused on the phenotypes of infiltrating macrophages/microglial cells and Stat3 activation in PCNSL cells. The correlation of Stat3 activation or density of M2 macrophage infiltration with patient prognosis was also evaluated. We performed immunostaining for CD68, CD163, CD204, and pStat3 using paraffin-embedded PCNSL specimens obtained from 43 patients. CD163 and CD204 served as markers of the M2 phenotype. Dense infiltration of CD68(+) macrophages was found in all samples. High numbers of CD163(+) and CD204(+) M2 macrophages/microglial cells were observed in 29 and 25 cases, respectively. Stat3 activation in lymphoma cells was enhanced in the patients who showed denser infiltration of CD163(+) macrophages/microglial cells in tumor tissues. In vitro co-culture experiment to investigate cell-cell interactions between macrophages and lymphoma cells found that Stat3 in lymphoma cells was strongly activated by co-culture with macrophages. Numbers of CD68(+), CD163(+), and CD204(+) tumor-associated macrophages/microglial cells (TAMs) and Stat3 activation in lymphoma cells were not correlated with prognosis. However, because Stat3 involvement in tumor development was demonstrated in several malignant tumors, our present finding that cell-cell interactions of M2 macrophage/microglial cells with lymphoma cells induced Stat3 activation may provide novel insights into PCNSL pathogenesis.

Supercooling and vitrification of aqueous glycerol solutions at normal and high pressures

The supercooling and vitrification of aqueous glycerol solutions was studied at high pressures. Homogeneous ice nucleation temperatures (T(H)) were obtained for aqueous glycerol solutions of R=50, 30, 20, 12, and 10 (R: moles of water/moles of glycerol) up to 300MPa. The R=20 glycerol solution formed a glass above 200MPa at a cooling rate of 200°C/min, indicating that pressure enhances glass-formation of aqueous glycerol solutions. The (dT(g)/dP) values were obtained for vitrified aqueous glycerol solutions of R=3, 5, 10, and 20. These data can be used for the development of cryo-preservation liquids for living cells at high pressures.