Epithelial and melanoma antigens in gliosarcoma. An immunohistochemical study.

Gliosarcomas are mixed tumors with malignant glial and mesenchymal elements. The number of GFAP-positive tumor cells decreases with the increase of sarcomatous components, until whole areas may be GFAP negative. These distinct differentiations may, however, lead to false interpretations in small tissue samples. In this connection, it is of interest that, according to other reports, glial tumors may be positive for different anti-keratin antibodies and this prompted us to undertake a systematic investigation of the immunoreactivity of gliosarcomas using a panel of well-characterized monoclonal antibodies against cytokeratins (KL1, AE 1/3, Lu-5, CK-19, CK MNF 116 and Ma-903). These cases were further studied with the anti-epithelial non-cytokeratin antibodies EMA, HEA 125, Ber-EP4, CEA as well as the melanoma-antibody HMB-45, Leu-M1, GFAP and vimentin. As screening study we examined 20 cerebral metastatic carcinomas, 21 malignant gliomas (including 6 gliosarcomas) and 3 metastatic melanomas with the monoclonal antibodies KL1 and HMB-45. All cerebral metastatic carcinomas and 4/6 gliosarcomas were positive for KL1, whereas all melanomas, 2 metastatic carcinomas and 3 gliosarcomas showed an immunostaining with HMB-45. All gliosarcomas were positive with at least one of the tested anti-cytokeratin antibodies. The gliosarcomas did not show an immunoreaction in any of the cases when CEA, HEA 125, Ber-EP4, EMA or Leu M1 were applied. In our opinion, the monoclonal antibodies HEA 125 and Ber-EP4 could obviously be helpful in differentiating gliosarcomas from metastatic carcinomas.     

Transcriptional factors for epithelial-mesenchymal transition are associated with mesenchymal differentiation in gliosarcoma

Gliosarcoma is a rare variant of glioblastoma characterized by a biphasic pattern of glial and mesenchymal differentiation. It is unclear whether mesenchymal differentiation in gliosarcomas is because of extensive genomic instability and/or to a mechanism similar to epithelial-mesenchymal transition (EMT). In the present study, we assessed 40 gliosarcomas for immunoreactivity of Slug, Twist, matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9), which are involved in EMT in epithelial tumors. Nuclear Slug expression was observed in >50% of neoplastic cells in mesenchymal tumor areas of 33 (83%) gliosarcomas, but not in glial areas (P < 0.0001). Nuclear Twist expression was observed in >50% of neoplastic cells in mesenchymal tumor areas of 35 (88%) gliosarcomas, but glial tumor areas were largely negative except in four cases (P < 0.0001). Expression of MMP-2 and MMP-9 was also significantly more extensive in mesenchymal than in glial tumor areas. None of 20 ordinary glioblastomas showed Slug or Twist expression in >10% neoplastic cells. Thus, expression of Slug, Twist, MMP-2 and MMP-9 was characteristic of mesenchymal tumor areas of gliosarcomas, suggesting that mechanisms involved in the EMT in epithelial neoplasms may play roles in mesenchymal differentiation in gliosarcomas.     

Genetic Alterations in Gliosarcoma and Giant Cell Glioblastoma

The majority of glioblastomas develop rapidly with a short clinical history (primary glioblastoma IDH wild‐type), whereas secondary glioblastomas progress from diffuse astrocytoma or anaplastic astrocytoma. IDH mutations are the genetic hallmark of secondary glioblastomas. Gliosarcomas and giant cell glioblastomas are rare histological glioblastoma variants, which usually develop rapidly. We determined the genetic patterns of 36 gliosarcomas and 19 giant cell glioblastomas. IDH1 and IDH2 mutations were absent in all 36 gliosarcomas and in 18 of 19 giant cell glioblastomas analyzed, indicating that they are histological variants of primary glioblastoma. Furthermore, LOH 10q (88%) and TERT promoter mutations (83%) were frequent in gliosarcomas. Copy number profiling using the 450k methylome array in 5 gliosarcomas revealed CDKN2A homozygous deletion (3 cases), trisomy chromosome 7 (2 cases), and monosomy chromosome 10 (2 cases). Giant cell glioblastomas had LOH 10q in 50% and LOH 19q in 42% of cases. ATRX loss was detected immunohistochemically in 19% of giant cell glioblastomas, but absent in 17 gliosarcomas. These and previous results suggest that gliosarcomas are a variant of, and genetically similar to, primary glioblastomas, except for a lack of EGFR amplification, while giant cell glioblastoma occupies a hybrid position between primary and secondary glioblastomas.     

Genetic profile of gliosarcomas

There are distinct genetic pathways leading to the glioblastoma, the most malignant astrocytic brain tumor. Primary (de novo) glioblastomas develop in older patients and are characterized by epidermal growth factor (EGF) receptor amplification/overexpression, p16 deletion, and PTEN mutations, whereas secondary glioblastomas that progressed from low-grade or anaplastic astrocytoma develop in younger patients and frequently contain p53 mutations. In this study, we assessed the genetic profile of gliosarcoma, a rare glioblastoma variant characterized by a biphasic tissue pattern with alternating areas displaying glial and mesenchymal differentiation. Single-strand conformation polymorphism followed by direct DNA sequencing revealed p53 mutations in five of 19 gliosarcomas (26%) and PTEN mutations in seven cases (37%). Homozygous p16 deletion was detected by differential polymerase chain reaction in seven (37%) gliosarcomas. The overall incidence of alterations in the Rb pathway (p16 deletion, CDK4 amplification, or loss of pRb immunoreactivity) was 53%, and these changes were mutually exclusive. Coamplification of CDK4 and MDM2 was detected in one gliosarcoma. None of the gliosarcomas showed amplification or overexpression of the EGF receptor. Thus gliosarcomas exhibit a genetic profile similar to that of primary (de novo) glioblastomas, except for the absence of EGFR amplification/overexpression. Identical PTEN mutations in the gliomatous and sarcomatous tumor components were found in two cases. Other biopsies contained p16 deletions, an identical p53 mutation, or coamplification of MDM2 and CDK4 in both tumor areas. This strongly supports the concept of a monoclonal origin of gliosarcomas and an evolution of the sarcomatous component due to aberrant mesenchymal differentiation in a highly malignant astrocytic neoplasm.     

Comprehensive analysis of genomic alterations in gliosarcoma and its two tissue components

Gliosarcoma is a variant of glioblastoma multiforme characterized by two components displaying gliomatous or sarcomatous differentiation. We investigated 38 gliosarcomas for aberrations of tumor-suppressor genes and proto-oncogenes that are commonly altered in glioblastomas. Amplification of CDK4, MDM2, EGFR, and PDGFRA were found in 11% (4/35), 8% (3/38), 8% (3/38), and 3% (1/35) of the tumors, respectively. Nine of 38 gliosarcomas (24%) carried TP53 mutations. PTEN mutations were identified in 45% (9/20) of the investigated tumors. Twenty gliosarcomas were analyzed by comparative genomic hybridization (CGH). Chromosomal imbalances commonly detected were gains on chromosomes 7 (15/20; 75%), X (4/20; 20%), 9q, and 20q (3/20, 15% each); and losses on chromosomes 10 and 9p (7/20, 35% each), and 13q (3/20, 15%). Five different high-level amplifications were mapped to 4q12-q21 (1 case), 6p21 (1 case), 7p12 (2 cases), proximal 12q (4 cases), and 14q32 (1 case) by CGH. Southern blot and/or differential PCR analyses identified amplification of PDGFRA (4q12), CCND3 (6p21), EGFR (7p12), CDK4 (12q14) and/or MDM2 (12q14.3-q15), and AKT1 (14q32.3) in the respective tumors. Separate analysis of the gliomatous and sarcomatous components of eight gliosarcomas by CGH after microdissection and universal DNA amplification revealed that both components shared 57% of the chromosomal imbalances detected. Taken together, our data indicate that the genomic changes in gliosarcomas closely resemble those found in glioblastomas. However, the number of chromosomes involved in imbalances in gliosarcomas was significantly lower than that in glioblastomas, indicating a higher genomic stability in gliosarcomas. In addition, we provide further support for the hypothesis that the gliomatous and sarcomatous components are derived from a single precursor cell clone, which progressed into subclones with distinct morphological features during tumor evolution. According to our data, gain/amplification of genes on proximal 12q may facilitate the development of a sarcomatous phenotype.     

Amplification of the STOML3, FREM2, and LHFP genes is associated with mesenchymal differentiation in gliosarcoma

Gliosarcoma is a rare glioblastoma variant characterized by a biphasic tissue pattern with alternating areas that display either glial (glial fibrillary acidic protein-positive) or mesenchymal (reticulin-positive) differentiation. Previous analyses have shown identical genetic alterations in glial and mesenchymal tumor areas, suggesting that gliosarcomas are genetically monoclonal, and mesenchymal differentiation was considered to reflect the elevated genomic instability of glioblastomas. In the present study, we compared genome-wide chromosomal imbalances using array comparative genomic hybridization in glial and mesenchymal tumor areas of 13 gliosarcomas. The patterns of gain and loss were similar, except that the gain at 13q13.3-q14.1 (log(2) ratio >3.0), containing the STOML3, FREM2, and LHFP genes, which was restricted to the mesenchymal tumor area of a gliosarcoma. Further analyses of 64 cases of gliosarcoma using quantitative PCR showed amplification of the STOML3, FREM2, and LHFP genes in 14 (22%), 10 (16%), and 7 (11%) mesenchymal tumor areas, respectively, but not in glial tumor areas. Results of IHC analysis confirmed that overexpression of STOML3 and FREM2 was more extensive in mesenchymal than in glial tumor areas. These results suggest that the mesenchymal components in a small fraction of gliosarcomas may be derived from glial cells with additional genetic alterations.     

Melanoma-associated antigens in tumours of the nervous system: an immunohistochemical study with the monoclonal antibody HMB-45

Summary The aim of this study was to determine the specificity and sensitivity of the commercially available, monoclonal anti-melanoma antibody HMB-45 in brain tumours and peripheral nerve sheath tumours. Hence, a series of 155 different non-melanotic tumours of the central and peripheral nervous system were examined immunohistochemically. The brain lesions consisted of primary tumours and metastases from various carcinomas. Twenty melanotic tumours (cerebral metastases of malignant melanomas, meningeal melanomatosis, meningeal melanocytomas) and dermal blue cell naevi served as controls. All melanotic tumours stained positive. Furthermore, a positive immunohistochemical reaction was observed in the following non-melanotic tumours: gliosarcomas, primitive neuroectodermal tumours, ependymoma, malignant schwannomas and different intracranial hamartomas. Two plasmocytomas and 4 metastatic carcinomas also revealed positive staining for HMB-45. Our results confirm the necessity for cautious interpretation of HMB-45 immunoreactivity as a tool in the immunohistochemical characterization of nervous system tumours.     

Irradiation of intracerebral 9L gliosarcoma by a single array of microplanar x-ray beams from a synchrotron: balance between curing and sparing

The purpose of this work was the understanding of microbeam radiation therapy at the ESRF in order to find the best compromise between curing of tumors and sparing of normal tissues, to obtain a better understanding of survival curves and to report its efficiency. This method uses synchrotron-generated x-ray microbeams. Rats were implanted with 9L gliosarcomas and the tumors were diagnosed by MRI. They were irradiated 14 days after implantation by arrays of 25 microm wide microbeams in unidirectional mode, with a skin entrance dose of 625 Gy. The effect of using 200 or 100 microm center-to-center spacing between the microbeams was compared. The median survival time (post-implantation) was 40 and 67 days at 200 and 100 microm spacing, respectively. However, 72% of rats irradiated at 100 microm spacing showed abnormal clinical signs and weight patterns, whereas only 12% of rats were affected at 200 microm spacing. In parallel, histological lesions of the normal brain were found in the 100 microm series only. Although the increase in lifespan was equal to 273% and 102% for the 100 and 200 microm series, respectively, the 200 microm spacing protocol provides a better sparing of healthy tissue and may prove useful in combination with other radiation modalities or additional drugs.     

Iron oxide nanoparticles as a drug delivery vehicle for MRI monitored magnetic targeting of brain tumors

This study explored the possibility of utilizing iron oxide nanoparticles as a drug delivery vehicle for minimally invasive, MRI-monitored magnetic targeting of brain tumors. In vitro determined hydrodynamic diameter of approximately 100 nm, saturation magnetization of 94 emicro/g Fe and T2 relaxivity of 43 s(-1)mm(-)(1) of the nanoparticles suggested their applicability for this purpose. In vivo effect of magnetic targeting on the extent and selectivity of nanoparticle accumulation in tumors of rats harboring orthotopic 9L-gliosarcomas was quantified with MRI. Animals were intravenously injected with nanoparticles (12 mg Fe/kg) under a magnetic field density of 0 T (control) or 0.4 T (experimental) applied for 30 min. MR images were acquired prior to administration of nanoparticles and immediately after magnetic targeting at 1h intervals for 4h. Image analysis revealed that magnetic targeting induced a 5-fold increase in the total glioma exposure to magnetic nanoparticles over non-targeted tumors (p=0.005) and a 3.6-fold enhancement in the target selectivity index of nanoparticle accumulation in glioma over the normal brain (p=0.025). In conclusion, accumulation of iron oxide nanoparticles in gliosarcomas can be significantly enhanced by magnetic targeting and successfully quantified by MR imaging. Hence, these nanoparticles appear to be a promising vehicle for glioma-targeted drug delivery.     

Dural lesions mimicking meningiomas

Recently, a number of neoplastic and nonneoplastic entities have been reported that radiographically and clinically mimic meningiomas. Because these lesions occur infrequently and may resemble a meningioma during intraoperative analysis, they may not be considered in the differential diagnosis. This review (and case illustrations) considers some of the newly recognized and notable lesions that can mimic meningiomas, including solitary fibrous tumors, gliosarcomas, leiomyosarcomas, hemangiopericytomas, melanocytomas, Hodgkin's disease, plasmacytomas, inflammatory pseudotumors, neurosarcoidosis, plasma cell granulomas, Rosai-Dorfman disease, Castleman's disease, xanthomas, rheumatoid nodules, and tuberculomas. Awareness that these lesions involve the dura may facilitate intraoperative recognition and, in some cases, preclude unnecessary additional surgery.     

Gastrin significantly modifies the migratory abilities of experimental glioma cells

Malignant astrocytic tumors are characterized by the pronounced and diffuse migration of tumor astrocytes into the brain parenchyma. The present study shows that gastrin is a brain neuropeptide that is able to significantly modulate astrocytic tumor migration at both invasion and motility levels. In the matter of invasion, gastrin severely reduces the in vitro invasive abilities of C6 rat glioma, 9L rat gliosarcoma, and U373 human glioma cells in a collagen matrix. In vitro, gastrin also markedly modifies the motility features in both C6 and U373 cells, at least partly through a decrease in the expression of the RhoA small GTPase, and so brings about some dramatic modifications to the organization in the actin cytoskeleton. The in vitro preincubation of C6 tumor cells with gastrin significantly increases the life spans of rats stereotactically implanted with these cells as compared with the survival periods of rats implanted with gastrin-untreated C6 cells. As suggested by our in vitro experiments, these effects, observed in vivo cannot relate to only the gastrin-induced decrease in tumor astrocyte migratory abilities. Indeed, gastrin also induces immunomodulatory effects, because we observed a marked gastrin-induced recruitment of lymphocytes into C6 gliomas and 9L gliosarcomas. These data all suggest that gastrin can act as an endogenous modulator of glioma progression.     

A cytogenetic study of 53 human gliomas

Cytogenetic studies were performed on human glioma samples obtained by stereotactic biopsy, stereotactic craniotomy, or routine craniotomy. Using in situ culture and robotic harvesting techniques, we obtained suitable metaphases in 50 (94%) of 53 tumors, including 28 diffuse astrocytomas, four juvenile pilocytic astrocytomas, two gliosarcomas, three other miscellaneous astrocytomas, eight oligodendrogliomas, four mixed oligodendroglioma-astrocytomas, and four ependymomas. Cytogenetic studies were performed only on primary cultures; the mean culture time was 9.6 days (range 1-31 days). One or more chromosomally abnormal clones were observed in 35 (66%) tumors. Eleven (21%) other specimens had random nonclonal chromosome abnormalities. In four (8%) specimens, no chromosome abnormalities were noted. The results of this study suggest that grade 3 and 4 tumors are more likely to contain an abnormal clone than tumors of grade 1 or 2 (p less than 0.01). The most common numeric chromosome abnormalities were -6, +7, -10, -13, -14, -15, -18, and -Y. The most common structural abnormalities involved 1p, 6q, 7q, 8p, 9p, 11p, 11q, 13q, and 19q. Four tumors had two or more independent clones and ten contained subclones demonstrating karyotype evolution. With in situ culture and robotic harvesting techniques, cytogenetic studies can be successful on nearly all human gliomas, including those derived from small stereotactic biopsies.     

Multiparametric MRI as an early biomarker of individual therapy effects during concomitant treatment of brain tumours

The aim of this study was to determine the ability of multiparametric MRI to identify the early effects of individual treatment, during combined chemo‐radiotherapy on brain tumours. Eighty male rats bearing 9L gliosarcomas were randomized into four groups: untreated, anti‐angiogenic therapy (SORA group), microbeam radiation therapy (MRT group) and both treatments (MRT+SORA group). Multiparametric MRI (tumour volume, diffusion‐weighted MR imaging (ADC), blood volume fraction (BVf), microvessel index (VSI), vessel wall integrity (AUC_P846) and tissue oxygen saturation (StO₂)) was performed 1 day before and 2, 5 and 8 days after treatment initiation. Unpaired t‐tests and one‐way ANOVA were used for statistical analyses. Each MR parameter measured in our protocol was revealed to be sensitive to tumour changes induced by any of the therapies used (individually or combined). When compared with untreated tumours, SORA induced a decrease in BVf, VSI, StO₂ and AUC_P846, MRT generated an increase in ADC and AUC_P846 and combined therapies yielded mixed effects: an increase in ADC and AUC_P846 and a decrease in BVf, StO₂ and AUC_P846. MRT and MRT+SORA significantly slowed tumour growth. Despite these two groups presenting with similar tumour sizes, the information yielded from MR multiparameter assessment indicated that, when used concomitantly, each therapy induced distinguishable and appreciable physiological changes in the tumour. Our results suggest that multiparametric MRI can monitor the effects of individual treatments, used concomitantly, on brain tumours. Such monitoring would be useful for the detection of tumour resistance to drug/radiotherapy in patients undergoing concomitant therapies. Copyright © 2015 John Wiley & Sons, Ltd.     

Polypyrimidine tract binding protein and Notch1 are independently re-expressed in glioma.

Polypyrimidine tract binding protein (PTB) is expressed in developing mammalian astrocytes, absent in mature adult astrocytes, and aberrantly elevated in gliomas. It is unclear whether PTB is a coincidental marker of tumor progression or a significant mediator of tumorigenesis. In developing Drosophila, the absence of the PTB homolog, hephaestus, results in increased Notch activity. Since Notch is a well-known inducer of glial cell fate, we determined whether overexpression of PTB in glial cell tumors provides a selective growth advantage by inhibiting activated Notch (Notch1IC)-mediated differentiation. To do this, we performed an immunohistochemical analysis for expression of PTB, activated Notch1 (Notch1IC), Hes1 (a Notch target), and GFAP on an extensive human tissue microarray that included 246 gliomas, 10 gliosarcomas, and 10 normal brains. Statistically significant PTB overexpression was seen in all glioma grades, with the highest increase in grade IV tumors. Notch1IC was also abnormally expressed in gliomas except in a subset of grade IV tumors in which it was absent. This decrease in Notch1IC was not associated with increased PTB expression. We conclude that PTB, and Notch1 serve as independent and functionally unlinked markers of glioma progression.     

Phenotype vs genotype in the evolution of astrocytic brain tumors

Astrocytic brain tumors are the most frequent human gliomas and they include a wide range of neoplasms with distinct clinical, histopathologic, and genetic features. Diffuse astrocytomas are predominantly located in the cerebral hemispheres of adults and have an inherent tendency to progress to anaplastic astrocytoma and (secondary) glioblastoma. The majority of glioblastomas develop de novo (primary glioblastomas), without an identifiable less-malignant precursor lesion. These subtypes of glioblastoma evolve through different genetic pathways, affect patients at different ages, and are likely to differ in their responses to therapy. Primary glioblastomas occur in older patients and typically show epidermal growth factor receptor (EGFR) overexpression, PTEN mutations, p16 deletions, and, less frequently, MDM2 amplification. Secondary glioblastomas develop in younger patients and often contain TP53 mutations as their earliest detectable alteration. Morphologic variants of glioblastoma were shown to have intermediate clinical and genetic profiles. The giant cell glioblastoma clinically and genetically occupies a hybrid position between primary (de novo) and secondary glioblastomas. Gliosarcomas show identical gene mutations in the gliomatous and sarcomatous tumor components, which strongly supports the concept that there is a monoclonal origin for gliosarcomas and an evolution of the sarcomatous component due to aberrant mesenchymal differentiation in a highly malignant astrocytic neoplasm.     

Identification in Human Brain Tumors of DNA Sequences Specific for SV40 Large T Antigen

Simian virus 40 (SV40) sequences have recently been identified in a variety of human neoplasms, including mesothelioma, osteosarcoma, and brain tumors, but significant discrepancies exist regarding the frequency at which this occurs. The SV40 genome is 70% homologous to JC and BK, two related polyomaviruses that are highly prevalent in humans and which may cause in immune-compromised patients progressive multifocal leukoencephalopathy (PML) and cystitis, respectively. We have established a specific and sensitive method to identify SV40 sequence in DNA extracted from histological sections, using PCR followed by Southern hybridization to probes specific to the large T region. We found SV40 largeT antigen sequences in all brain tumor types investigated. High frequencies were found in low-grade astrocytomas, anaplastic astro-cytomas and secondary glioblastomas derived thereof (13/22, 59%) while somewhat lower frequencies were found in gemistocytic astrocytomas (9/28, 32%) and oligodendrogliomas (3/12, 25%). Primary glioblastomas, giant cell glioblastomas, and gliosarcomas, which clinically develop de novo, contained SV40 sequences in 11–25% of cases. Presence of viral DNA was also observed in pediatric brain tumors, including ependymomas (9/16, 56%), choroid plexus papillomas (6/16, 38%), and medulloblastomas (5/17, 29%). In 8 tumor biopsies with SV40 sequences, the adjacent normal brain tissue was also analyzed but was devoid of viral DNA in all but one case. BK and JC virus sequences were rarely detected, the overall frequencies being 3% and 2%, respectively. It remains to be shown whether the presence of SV40 contributes significantly to malignant transformation or whether certain human neoplasms provide a microenvironment that favors viral replication in humans with latent SV40 infection.     

DCE and DW-MRI monitoring of vascular disruption following VEGF-Trap treatment of a rat glioma model

Vascular‐targeted therapies have shown promise as adjuvant cancer treatment. As these agents undergo clinical evaluation, sensitive imaging biomarkers are needed to assess drug target interaction and treatment response. In this study, dynamic contrast enhanced MRI (DCE‐MRI) and diffusion‐weighted MRI (DW‐MRI) were evaluated for detecting response of intracerebral 9 L gliosarcomas to the antivascular agent VEGF‐Trap, a fusion protein designed to bind all forms of Vascular Endothelial Growth Factor‐A (VEGF‐A) and Placental Growth Factor (PGF). Rats with 9 L tumors were treated twice weekly for two weeks with vehicle or VEGF‐Trap. DCE‐ and DW‐MRI were performed one day prior to treatment initiation and one day following each administered dose. Kinetic parameters (K^trans, volume transfer constant; k_ep, efflux rate constant from extravascular/extracellular space to plasma; and v_p, blood plasma volume fraction) and the apparent diffusion coefficient (ADC) over the tumor volumes were compared between groups. A significant decrease in kinetic parameters was observed 24 hours following the first dose of VEGF‐Trap in treated versus control animals (p < 0.05) and was accompanied by a decline in ADC values. In addition to the significant hemodynamic effect, VEGF‐Trap treated animals exhibited significantly longer tumor doubling times (p < 0.05) compared to the controls. Histological findings were found to support imaging response metrics. In conclusion, kinetic MRI parameters and change in ADC have been found to serve as sensitive and early biomarkers of VEGF‐Trap anti‐vascular targeted therapy. Copyright © 2011 John Wiley & Sons, Ltd.     

Molecular and Morphologic Correlates of the Alternative Lengthening of Telomeres Phenotype in High‐Grade Astrocytomas

Recent studies suggest that the telomere maintenance mechanism known as alternative lengthening of telomeres (ALT) is relatively more common in specific glioma subsets and strongly associated with ATRX mutations. We retrospectively examined 116 high‐grade astrocytomas (32 pediatric glioblastomas, 65 adult glioblastomas, 19 anaplastic astrocytomas) with known ALT status using tissue microarrays to identify associations with molecular and phenotypic features. Immunohistochemistry was performed using antibodies against ATRX, DAXX, p53 and IDH1^R132H mutant protein. EGFR amplification was evaluated by fluorescence in situ hybridization (FISH). Almost half of fibrillary and gemistocytic astrocytomas (44%) demonstrated ALT. Conversely all gliosarcomas (n = 4), epithelioid (n = 2), giant cell (n = 2) and adult small cell astrocytomas (n = 7) were ALT negative. The ALT phenotype was positively correlated with the presence of round cells (P = 0.002), microcysts (P < 0.0002), IDH1 mutant protein (P < 0.0001), ATRX protein loss (P < 0.0001), strong P53 immunostaining (P < 0.0001) and absence of EGFR amplification (P = 0.004). There was no significant correlation with DAXX expression. We conclude that ALT represents a specific phenotype in high‐grade astrocytomas with distinctive pathologic and molecular features. Future studies are required to clarify the clinical and biological significance of ALT in high‐grade astrocytomas.     

大鼠失血性休克和回输血后重要器官组织脂质过氧化及腺苷酸代谢变化

作者观察到大鼠失血性休克早期各脏器（小肠、肺、肝）ＭＤＡ含量变化不显著，甚或有减少（心、肾）；回输血后除肺外，其它脏器ＭＤＡ含量均显著增加。心、肝、肾组织ＡＴＰ及能荷回输血后仍低于对照组；ＳＯＤ、ＣＡＴ预处理后各脏器ＭＤＡ含量均显著减少，心、肝、行组织ＡＴＰ、能荷显著升高。结果提示：失血性休克回输血后多个器官组织氧自由基产生增加，能量代谢恢复亦发生障碍。ＳＯＤ、ＣＡＴ治疗可降低组织脂质过氧化反应，促进能量代谢的恢复。