The stability and catalytic activity of W13@Pt42 core-shell structure.

This paper reports a study of the electronic properties, structural stability and catalytic activity of the W13@Pt42 core-shell structure using the First-principles calculations. The degree of corrosion of W13@Pt42 core-shell structure is simulated in acid solutions and through molecular absorption. The absorption energy of OH for this structure is lower than that for Pt55, which inhibits the poison effect of O containing intermediate. Furthermore we present the optimal path of oxygen reduction reaction catalyzed by W13@Pt42. Corresponding to the process of O molecular decomposition, the rate-limiting step of oxygen reduction reaction catalyzed by W13@Pt42 is 0.386 eV, which is lower than that for Pt55 of 0.5 eV. In addition by alloying with W, the core-shell structure reduces the consumption of Pt and enhances the catalytic efficiency, so W13@Pt42 has a promising perspective of industrial application.

A spinal tumor showing mixed features of ependymoma and hemangioblastoma: a case report and literature review.

We report an intramedullary spinal tumor consisting of an ependymoma and a hemangioblastoma (HB). A 37-year-old woman presented with progressive bilateral lower limb sensory and motor deficits. Magnetic resonance imaging showed a single intramedullary mass in the thoracic cord (T4-T6 level). Clinically, the patient had no von Hippel-Lindau disease and neurofibromatosis type 2. Metastatic carcinomas including renal cell carcinoma were altogether negative. Complete surgical resection was performed. Histologically, the tumor consisted of a mixed ependymoma and HB. Tumor cells of ependymoma displayed a rather uniform appearance with round to oval nuclei having salt-and-pepper-like chromatin, forming perivascular pseudorosette structures with radially arranged, tapering cell processes extending to intratumoral blood vessels. Stromal cells of HB had vacuolated or homogeneously eosinophilic cytoplasm and variable sized hyperchromatic nuclei within a background of capillaries. Immunohistochemically, tumor cells of ependymoma were strongly positive for glial fibrillary acidic protein (GFAP), focally positive for epithelial membrane antigen (EMA) and D2-40 in a dot-like or ring-like pattern. Stromal cells of HB showed immunoreactivity for S100, vimentin, inhibin-α, D2-40, EMA and cytokeratins (CK: AE1/AE3, CK19). A review of the literature, in conjunction with the present case, shows that ependymomas and HBs may have a close relationship with each other.

Papillary meningioma: clinical and histopathological observations.

Papillary meningioma is a rare subtype of malignant meningiomas, which is classified by the World Health Organization as Grade III. Because of lack of large sample size case studies, many of the specific characteristics of papillary meningioma are unclear. This study investigated by retrospective analysis the clinical, radiological and histopathological findings of 17 papillary meningioma patients who underwent surgical resection or biopsy, to assess the characteristics of papillary meningioma. Eight female and nine male patients were included, with a mean age of 40 (range: 6 to 55) years. Tumors were mostly located in the cerebral convexity and showed irregular margins, absence of a peritumoral rim, heterogeneous enhancement and severe peritumoral brain edema on preoperative images. Brain invasion was often confirmed during the operations, with abundant to exceedingly abundant blood supply. Intratumoral necrosis and mitosis was frequently observed on routinely stained sections. The average MIB-1 labeling index was 6.9%. Seven cases experienced tumor recurrence or progression, while seven patients died 6 to 29 months after operation. Radiation therapy was given in 52.9% of all cases. Univariate analysis showed that only the existence of intratumoral necrosis and incomplete resection correlated with tumor recurrence. The 3-year progression free survival was 66.7% after gross total resection and 63.6% for other cases. The 3-year mortality rate was 50% after gross total resection and 63.6% for other cases. Papillary meningioma has specific clinical and histopathological characteristics. Tumor recurrence (or progression) and mortality are common. Gross total tumor resection resulted in less recurrence and mortality.

Secretory meningiomas: clinical, radiological and pathological findings in 70 consecutive cases at one institution.

Secretory meningioma (SM) is a rare, benign subtype of meningioma. Between January 2005 and December 2010, 70 SMs were operated on at the Department of Neurosurgery, Huashan Hospital, Fudan University. We retrospectively analyzed the clinical data, radiological and immunohistochemical findings, and patient outcome to discuss the specific features of SMs. Cranial base preference, hyper-signal in T2 weighted MR image, "xenon light" gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) enhancement were frequently observed in the 70 cases. Non-skull base SMs, which received more complete resection (p<0.01) and had better short-term and long-term outcome, were observed with more severe peritumoral brain edema (PTBE) (p<0.001). In follow-up, only 1 cranial base SM case showed tumor progression. 3 cases died after operation, all with cranial base SMs. As for the 10 cases given Simpson grade 3 or 4 resection who were available at follow-up, 3 died, 5 received gamma-knife therapy, and the other 2 cases received no treatment at all. Only one of the 2 residual SMs without postoperative radiation presented minor progression at a median of 48 months follow-up. In conclusion, cranial base preference, hyper-signal T2 weighted MR image and "xenon light" GD-DTPA enhancement are specific for SMs. Prognosis of SMs is related with operation completeness and surgical risks, rather than the extent of PTBE. Residual SM grows slowly and reacts well to gamma-knife therapy.

Histopathological classification and location of consecutively operated meningiomas at a single institution in China from 2001 to 2010.

BACKGROUND: Meningioma is one of the most common primary tumors of the central nervous system, but there are not many detailed studies on the sex, age, subtypes and locations of large series. This study was a retrospective analysis of the characteristics of meningioma cases consecutively operated on at a single institution in China from 2001 to 2010. METHODS: This study investigated the demographic background of 7084 meningioma cases, and the subtypes and locations of the tumors. Sex and age distributions were analyzed, and the pathological subtypes were classified according to the World Health Organization (WHO) classification. The location of the meningiomas was also categorized. RESULTS: The female:male ratio of the 7084 cases was 2.34:1. The mean age was 51.4 years (range, 11 months-86 years). The mean age of cases of WHO grade I meningioma was significantly older than that of grade II or III meningiomas (P < 0.001, Fisher's Least Significant Digit test). There was a significantly higher female:male ratio in WHO grade I meningiomas than in grade II or grade III meningiomas (2.57, 1.03 and 0.76, respectively; P < 0.001, χ(2) test). Meningothelial (n = 2061) and fibrous meningiomas (n = 3556) were the most common subtypes, comprising 79.3% of all meningiomas. All meningioma cases were classified into 23 locations in this study, with the cerebral convexity the most common site (38.33%, n = 2722). Cases with uncommon locations such as extra-cranial and sylvian fissure meningiomas were also present in this series. CONCLUSIONS: Female predominance was found for benign meningiomas, while malignant subtypes showed male predominance. The mean age of patients with WHO grade I meningiomas was older than that of patients with higher-grade tumors. Meningothelial and fibrous meningiomas were the most common subtypes. The cerebral convexity was the most common meningioma location.

Embryonal tumor with abundant neuropil and true rosettes (ETANTR) with a focal amplification at chromosome 19q13.42 locus: further evidence of two new instances in China.

Recently, the term "embryonal tumor with multilayered rosettes" (ETMR), including embryonal tumor with abundant neuropil and true rosettes (ETANTR) and ependymoblastoma (EBL) as a distinct tumor entity, has become an important topic of discussion for neuropathologists since the discovery of a unique genomic alteration in 2009. Here, we contribute two new East Asian instances of ETANTR in a 29-month-old boy who underwent subtotal resection of a large tumor in the bilateral parieto-occipital lobes and a 4-year-old boy who underwent subtotal resection of the right midpontine neoplasm. Both tumors showed a typical histopathological pattern of hypercellular clusters of undifferentiated small cells and ependymoblastic rosettes admixed with paucicellular neuropil-like zones indicative for ETANTR. Rare Homer-Wright neuroblastic rosettes and papillary pseudorosettes, as well as enlarged lumina with mucinous material, were also observed. Immunohistological studies revealed that tumor cells in hypercellular and paucicellular zones were diffusely positive for microtubule-associated protein 2; ependymoblastic rosette cells stained with epithelial membrane antigen at the luminal membrane and exhibiting strong immunoreactivity with p53 protein. ß-Catenin and Nestin were frequently detected in the hypercellular zones as well as in the ependymoblastic rosettes. Fluorescence in situ hypribization analysis revealed that both cases contained a unique focal amplification at the 19q13.42 chromosome locus and chromosome 2 polysomy. A new WHO classification of tumors of the CNS should be considered for these neoplasms with unique focal amplification at the 19q13.42 chromosome locus, based on the clinicopathological and molecular features of ETANTR that are distinct and reproducibly recognizable.

Rosette-forming glioneuronal tumor: report of an unusual case with intraventricular dissemination.

A rosette-forming glioneuronal tumor (RGNT) was encountered in a 16-year-old Chinese girl. She experienced seizures with loss of consciousness for 1 month prior to diagnosis. A brain MRI revealed multifocal masses occupying all of the ventricular system associated with marked hydrocephalus. A biopsy was performed on the right lateral ventricle using a neuroendoscope and the patient was given postoperative radiotherapy. She was followed for 7 months, and there was no radiological or clinical evidence of tumor progression. Histological examination demonstrated two regions characterized by predominant neurocytic rosettes and scant low grade astrocytoma. No histological anaplasia was present. Immunohistological studies showed that the small round tumor cells forming rosettes were strongly positive for Olig2. A chromosome 1p/19q co-deletion was not detected by FISH analysis. While the pathological features of our case closely resembled those reported in the original description, the diffuse intraventricular growth pattern of the tumor was different from previous examples. Further long-term follow-up studies are required to assess the biological behavior and clinical outcome of the RGNT entity.

Messenger RNA expression of translationally controlled tumor protein (TCTP) in liver regeneration and cancer.

OBJECTIVE: Translationally controlled tumor protein (TCTP) was recently reported to be involved in tumor reversion. In order to understand TCTP mRNA transcript in proliferative tissue and malignant lesions, the mRNA expression of TCTP was determined in a rat model of liver regeneration and human liver cancer tissues. In addition, the potential role of TCTP on suppression of liver cancer was investigated. MATERIALS AND METHODS: Liver regeneration model was established by a two-thirds partial hepatectomy (PH) in adult, male Sprague-Dawley rat. TCTP mRNA expression was determined by semiquantitative RT-PCR analysis. Antisense mRNA of TCTP was transfected into the SMMC-7721 liver cancer cell line. Biological assay of proliferation and cell cycle were analysed by MTT and flow cytometry, respectively. RESULTS: After PH of rats, the level of TCTP mRNA transcript was upregulated slightly in liver tissue at 1 hour followed by a high expression from 3 to 12 hours, which then decreased dramatically at 24 hours before returning to original level during liver tissue proliferation. TCTP mRNA transcript increased significantly in liver cancer tissues when compared to non-cancerous adjacent tissues as control. The transfection with antisense oligodeoxynucleotides of TCTP led to decreased proliferation of SMMC-7721 cells resulting in cell cycle arrest and pro-apoptosis. CONCLUSION: The results suggested that TCTP mRNA expression might be stage-specific in the proliferation of liver tissue but alter abnormally in cancer lesions. TCTP could be used as a potential target for suppression of liver tumorigenicity.