Chemically tailored block copolymers for highly reliable sub-10-nm patterns by directed self-assembly.

While block copolymer (BCP) lithography is theoretically capable of printing features smaller than 10 nm, developing practical BCPs for this purpose remains challenging. Herein, we report the creation of a chemically tailored, highly reliable, and practically applicable block copolymer and sub-10-nm line patterns by directed self-assembly. Polystyrene-block-[poly(glycidyl methacrylate)-random-poly(methyl methacrylate)] (PS-b-(PGMA-r-PMMA) or PS-b-PGM), which is based on PS-b-PMMA with an appropriate amount of introduced PGMA (10-33 mol%) is quantitatively post-functionalized with thiols. The use of 2,2,2-trifluoroethanethiol leads to polymers (PS-b-PGFMs) with Flory-Huggins interaction parameters (χ) that are 3.5-4.6-times higher than that of PS-b-PMMA and well-defined higher-order structures with domain spacings of less than 20 nm. This study leads to the smallest perpendicular lamellar domain size of 12.3 nm. Furthermore, thin-film lamellar domain alignment and vertical orientation are highly reliably and reproducibly obtained by directed self-assembly to yield line patterns that correspond to a 7.6 nm half-pitch size.

Effect of the presence of trophectoderm vesicles on blastocyst in relation to in vitro hatching, clinical pregnancy, and miscarriage rates.

Trophectoderm vesicles (TVs) are observed in some blastocysts that penetrate cells from the zona pellucida to the outer margin. Therefore, we compared this incidence in relation to hatching, pregnancy, and miscarriage rates between conventional in vitro fertilization (c-IVF) and intracytoplasmic sperm injection (ICSI). Vitrified/warmed blastocysts (n = 112) were derived from surplus embryos. The blastocysts were then observed using time-lapse cinematography to resolve the relationship between hatching and implantation. Another study was conducted that comprised 681 embryo transfer cycles in 533 patients who received a single vitrified/warmed blastocyst from our clinic. The incidence of TV was significantly higher in embryos inseminated by ICSI compared with c-IVF [ICSI: 51/56 (91 %); c-IVF: 25/56 (45 %); P < 0.01]. The successful hatching rate was significantly lower in ICSI than in c-IVF [ICSI: 11/56 (20 %); c-IVF: 29/56 (52 %); P < 0.01]. In addition, the hatching rate was significantly lower when TVs were present (14/76; 18 %) than in non-TV embryos (26/36; 72 %) (P < 0.01). In regard to the clinical study results, no significant differences were found between the groups in the pregnancy rate (TV present group: 107/183, 58.5 %; TV absent group: 273/498, 54.8 %) and miscarriage rate (TV present group: 21/107, 19.6 %; TV absent group: 53/273, 19.4 %). In vivo, we hypothesized that hatching and hatched would occur naturally by assisting protease action in the uterus; therefore, these results suggest that the presence of TV has no effect on pregnancy rates in the clinical setting.

Measurement and cellular sources of the soluble interleukin-2 receptor in primary central nervous system lymphoma.

The aims of this study were to determine the diagnostic utility of the serum levels of the soluble interleukin 2 receptor (sIL-2R) as a tumor marker of primary central nervous system lymphoma (PCNSL) and to investigate the cellular source of sIL-2R using immunohistochemical staining. The serum sIL-2R levels of 37 samples from suspected PCNSL patients were measured. There were 13 patients with PCNSL and 24 patients with other diseases such as glioma, metastatic tumor, inflammation, or cerebrovascular disease. The serum sIL-2R levels of the PCNSL cases and other brain diseases were 629.5 ± 586.0 U/ml (mean ± SD; range 189-2220 U/ml) and 408.5 ± 250.7 U/ml (160-837 U/ml), respectively. The serum sIL-2R levels of the two groups overlapped, and hence the difference between them was not significant. sIL-2R is the α subunit of IL-2R. It is also known as CD25, and is cleaved from its position in the cell membrane and released into the blood. CD25 expression was immunohistochemically detected in 7 of 11 PCNSL samples. Confocal laser microscopy revealed that CD25 signals were present in atypical cells and mononuclear cells. We concluded that both lymphoma cells and infiltrating T cells express CD25, which is one of the cellular sources of sIL-2R.

Coincident choroid plexus carcinoma and adrenocortical tumor in an infant.

We report a case of a 20-month-old girl with a large choroid plexus carcinoma arising in the left lateral ventricle and an adrenocortical tumor. Following brain tumor resection, the patient was treated with radiation and chemotherapy. The adrenocortical tumor was found with the manifestation of precocious puberty. TP53 gene mutation (exons 4-10) was not detected in either specimen. The patient had leptomeningeal dissemination and died 26 months later.

Clinicopathological features in the recurrence of oligodendroglioma and diffuse astrocytoma.

To investigate whether grade II oligodendroglioma was transformed to glioblastoma or not, histopathological evaluation of recurrent oligodendrogliomal tumors (OG) and diffuse astrocytomas (DA) was performed. The OG group was composed of ten patients with OG, including seven oligodendrogliomas and three oligoastrocytomas. The DA group was composed of ten patients with DA, including eight fibrillary astrocytomas and two gemistocytic astrocytomas. The histopathological parameters of glioblastoma including nuclear atypia, multinucleated giant cells, glomeruloid tufts (GT) as a marker of microvascular proliferation, necrosis, and the Ki-67 staining index were investigated. Evaluation of these parameters was scored as follows: 0, none; 1, sporadic; 2, partial; 3, extensive. There were no cases of transformation to glioblastoma in the OG group. There were five cases of transformation to secondary glioblastoma in the DA group. In recurrent tumors, scores of GT and necrosis in the OG group were significantly lower than those in the DA group (p < 0.005). Nuclear atypia and high proliferative activity (Ki-67 index) were identified in recurrent tumors of the OG group. Our study suggested that the extent of GT and necrosis in recurrent OG was less than that in recurrent DA, and transformation to glioblastoma from oligodendroglial tumor was exceptional.

Glioblastoma with oligodendroglial components: glioblastoma or anaplastic oligodendroglial tumors.

There have been some recent reports about glioblastoma with oligodendroglial (OG) components and malignant glioma with primitive neuroectodermal tumor (PNET)-like components. We investigated whether the presence and extent of OG components and PNET-like components influenced the prognosis in patients with glioblastoma. Eighty-six patients with glioblastoma were divided into an OG group (28 %), which revealed areas with a honeycomb appearance, and a non-OG group (72 %) without a honeycomb appearance. Patients with glioblastoma were also divided into a PNET group (27 %), which revealed areas with PNET-like features defined as neoplastic cells with high N/C ratios and hyperchromatic oval-carrot-shaped nuclei, and lacked the typical honeycomb appearance, and a non-PNET group (73 %) without PNET features. There were no significant differences in overall survival among the OG, the non-OG, the PNET, and the non-PNET groups. Two patients who survived longer than 36 months had both OG and PNET components with 1p or 19q loss of heterozygosity. Perinuclear halo, which is a characteristic feature of oligodendrogliomas, is an artifact of tissue fixation. Therefore, we should not readily use the term glioblastoma with OG components. PNET-like components, which are considered rare in malignant gliomas, may be frequently identified in glioblastomas.

Atypical and ischemic features of embolized meningiomas.

Preoperative embolization (POE) of meningiomas is widely used to facilitate surgical removal and to reduce intraoperative blood loss. The resulting necrosis and enhanced proliferation have been reported to affect subsequent histologic grading. However, there was little concern about ischemic features, for example small cells resembling atypical meningiomas, cytoplasmic vacuoles resembling clear cell meningioma, intercellular discohesion resembling rhabdoid meningioma, and perivascular cuffs resembling papillary meningioma. Therefore, the extent of these ischemic features was scored and Ki-67 staining indices were investigated in a POE group composed of 29 specimens of meningiomas treated with POE and compared with equivalent results for a non-POE group composed of 29 meningiomas that were not treated with POE. Small cells with high N/C ratios, cytoplasmic vacuoles, intercellular discohesion, and perivascular cuffs were significantly increased in the POE group (versus the non-POE group, p < 0.05). There were no significant differences of the Ki-67 index between the POE group (2.2%) and the non-POE group (1.9%) (p = 0.49). Our results suggest that small cell change resulting in necrosis may be followed by POE, and that clear cell-like, rhabdoid cell-like, or pseudopapillary pattern identified in meningiomas may also be induced by POE. Therefore, histological findings and determination of grading should be evaluated cautiously in cases of embolized meningiomas.

Lymphomatosis cerebri: clinical characteristics, neuroimaging, and pathological findings.

Lymphomatosis cerebri is a rare variant of primary central nervous system lymphoma. We present a case involving a 56-year-old immunocompetent woman who complained of rapid deterioration of her higher brain function over a 4-month period. Magnetic resonance imaging showed extensive white-matter lesions. During brain biopsy, a diffusely infiltrating lymphoma with distinctive immunohistochemical features was detected. Awareness of this unique presentation and early tissue diagnosis provide the best hope for instituting appropriate treatments.

Usefulness of intraoperative computed tomography in surgery for low-grade gliomas: a comparative study between two series without and with intraoperative computed tomography.

We have routinely used an intraoperative CT (i-CT) system in over 800 neurosurgical procedures since 1997. To investigate the utility of i-CT in low-grade glioma (LGG) surgery, we investigated whether i-CT improved the extent of tumor resection and prognosis in 46 patients with histologically confirmed LGG consisting of 27 patients with World Health Organization grade II astrocytoma, 12 with oligodendroglioma, and 7 with oligoastrocytoma. The patients were divided into two groups, 23 who underwent tumor resection without i-CT (non i-CT group) and 23 who underwent surgery using i-CT (i-CT group). We investigated the extent of tumor resection, pre- and postoperative Karnofsky performance status scores, and overall survival in each group. The extent of tumor resection was biopsy 26.1%, partial resection 60.9%, subtotal resection 13.0%, and gross total resection 0% in the non i-CT group, and 4.4%, 21.7%, 34.8%, and 39.1%, respectively, in the i-CT group. The i-CT group showed significantly longer overall survival than the non i-CT group among patients with astrocytoma (p < 0.05) and oligodendroglioma or oligoastrocytoma (p < 0.005). Prolonged survival was related to the extent of resection. There were no significant differences between pre- and postoperative Karnofsky performance status scores between the groups. Surgical resection using i-CT may improve the outcomes of patients with LGG. Additional resection or emergency treatment can be quickly performed as the surgical results are confirmed intraoperatively or immediately after the operation using i-CT.

Nestin expression in astrocytic tumors delineates tumor infiltration.

Nestin is an intermediate filament protein expressed in undifferentiated cells during central nervous system development, and glioma is known to be a highly infiltrative tumor. We determined whether nestin was expressed in astrocytic tumors and could identify infiltrating tumor cells. We screened 65 archival, paraffin-embedded adult astrocytic tumors using immunohistochemical staining and computerized overlaid photographs. Normal biopsied brains and metastatic brain tumors were also examined. The intensity of nestin expression corresponded to the tumor grade. All 33 glioblastoma cases showed positive and extensive staining, which was less positive in diffuse astrocytoma. Overlaid images showed that nestin immunostaining delineated tumor invasion into adjacent gray and white matter. Nestin is a useful marker for examining the infiltration of malignant cells into surrounding tissue.

Epstein-Barr virus-associated primary central nervous system lymphoma in the Japanese population.

The incidence of Epstein-Barr virus (EBV)-associated primary central nervous system (CNS) lymphoma in Japan was assessed using in situ hybridization of EBV-encoded small ribonucleic acid-1 (EBER-1) to identify the presence of EBV in 22 cases of formalin-fixed and paraffin-embedded primary CNS lymphoma. All cases were B-cell lymphoma. EBER-1 expression was observed in the nuclei of 3 of 22 primary CNS lymphoma cases (13.6%). The incidence of EBV-positive lymphoma in Japanese cases is higher than previously reported from Western countries. Patients with EBV-positive primary CNS lymphoma showed shorter survival than those with negative tumors (median 4 months vs. 26 months). EBER-1 in situ hybridization for the detection of EBV infection is rapid and reliable. Infrequent association suggests a different pathogenetic mechanism in the evolution of these tumors. Geographical differences in the incidence of EBV-associated primary CNS lymphoma may reflect epidemiological factors.

Thymic mucosa-associated lymphoid tissue lymphoma associated with bilateral orbital pseudotumor.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the thymus is a rare condition, often characterized by its occurrence in a context of autoimmunity. We reported a first case of thymic MALT lymphoma following bilateral orbital pseudotumor. A 48-year-old man presented with bilateral exophthalmos diagnosed as orbital pseudotumor. His symptoms were relieved by an oral corticosteroid. Eleven years later, a mediastinal tumor was incidentally discovered. A thymectomy was performed, and histological examination revealed that the mass was a MALT lymphoma. There was no recurrence with no further treatment.

Pathology of pineal parenchymal tumors.

Pinea l parenchymal tumors (PPTs) are neuroepithelial tumors that arise from pineocytes or their precursors. According to the currently revised WHO classification of tumors of the central nervous system, PPTs are subdivided into well-differentiated pineocytoma, poorly differentiated pineoblastoma, and PPT with intermediate differentiation (PPTID). Pineocytomas are slow-growing neoplasms composed of small mature cells resembling pineocytes. Large pineocytomatous rosettes are the most characteristic appearance. Pineoblastomas are the most primitive form and have a highly malignant biological behavior. PPTIDs show an intermediate histological grade of malignancy between pineocytomas and pineoblastomas. Immunohistochemically, PPTs are positive for several neuronal markers, including synaptophysin, neurofilaments, class III beta-tubulin, and chromogranin A. Photosensory differentiation is associated with immunoreactivity for retinal S-antigen and rhodopsin. Ultrastructurally, dense core vesicles and clear vesicles are present in both cytoplasm and cellular processes, the latter showing occasional synapse-like junctions. In some cases, ultrastructural evidence of photoreceptor differentiation, such as synaptic ribbons, microtubular sheaves, and cilia, is observed. Little is known about the genetics responsible for the development of PPTs. Several chromosomal abnormalities have been identified frequently in pineoblastomas and PPTIDs but less commonly in pineocytomas. Pineoblastomas are known to occur in patients with RB1 gene abnormalities, and these tumors also develop in patients with familial bilateral retinoblastomas (trilateral retinoblastoma syndrome). However, specific gene abnormalities involved in the tumorigenesis of PPTs have not been identified.

Pathology of intracranial germ cell tumors.

Intra cranial germ cell tumors (GCTs) usually arise in midline structures, including the pineal or suprasellar regions of children and young adults. The classification of GCTs includes germinoma, teratoma, yolk sac tumor, embryonal carcinoma, and choriocarcinoma. However, intracranial GCTs are often of mixed histologic composition (mixed GCTs), and only germinoma and teratoma are likely to be encountered as pure tumor types. Although GCTs are usually identified using conventional histological techniques, immunohistochemical studies are very useful for delineating these entities, using special markers such as human chorionic gonadotropin, alpha-fetoprotein, human placental alkaline phosphatase, cytokeratin, as well as c-kit and OCT4. Ultrastructural examination is also useful in confirming the identity of these tumors. Genetic alterations specifically encountered in central nervous system GCTs are largely unknown. Patients with Klinefelter syndrome or Down syndrome appear to be predisposed to the development of gonadal as well as intracranial germinomas. Frequent imbalances of chromosomes have been described in intracranial GCTs, including chromosomes 1, 8, 12, 13, 18 and X. Recently, p14 and c-kit gene alterations have been reported, particularly in some intracranial germinomas; however, their importance remains unclear.

Chromosome 1p and 19q deletions in malignant glioneuronal tumors with oligodendroglioma-like component.

Malignant glioneuronal tumors (MGNT) are suggested to be a new entity of glioma defined morphologically as any malignant glioma showing immunohistoichemical evidence of neuronal differentiation. We encountered seven cases of MGNT with oligodendroglioma-like component and investigated alternations of chromosome 1p and 19q in these tumors. Seven patients ranged from 33 to 62 years of age, four females and three males. Immunohistochemical study of these tumors was performed using neuronal markers (synaptophysin, neurofilament, beta-tubulin, chromogranin A and NeuN), astrocytic marker (GFAP) and Ki-67. We undertook a molecular cytogenetic study of tumor specimens obtained from seven patients using fluorescence in situ hybridization (FISH) with DNA probes mapping to chromosome 1p36, 1q25, 19p13 and 19q13. Histologically, these tumors resembled anaplastic oligodendroglioma. Immunohistochemically, tumor cells were immunoreactive for synaptophysin (7/7), neurofilament (6/7), beta-tubulin (5/7), chromogranin A (4/7), NeuN (2/7) and GFAP (7/7). The Ki-67 labeling index ranged from 4.5% to 20.7%. FISH analysis demonstrated either 1p or 19q deletion in all seven cases (100%) and both 1p and 19q deletions in five cases (71%). The 1p deletion was detected in six of seven cases (86%) and 19q deletion was also detected in six (86%). 1p and 19q deletions were present in MGNT, especially those with oligodendroglial components. We suggest that the oligodendroglial-like feature was associated with not only 1p or 19q loss but also differentiation along neuronal cell lines as a factor of favorable prognosis in glial tumors. It is inappropriate to make a diagnosis of oligodendroglioma based only on morphological resemblance to oligodendroglia.

Prognostic significance of the immunohistochemical expression of O6-methylguanine-DNA methyltransferase, P-glycoprotein, and multidrug resistance protein-1 in glioblastomas.

We studied the expression of O(6)-methylguanine-DNA methyltransferase (O(6)-MGMT), P-glycoprotein (Pgp), and multidrug resistance protein-1 (MRP-1) in 23 glioblastomas using RT-PCR, methylation-specific PCR, and immunohistochemistry, and analyzed their association with overall patient survival. Univariate analysis of collected data demonstrated that the expressions of O(6)-MGMT and MRP-1 detected by immunohistochemistry, in addition to the consistent factors, including preoperative Karnofsky performance scale (KPS), radical surgery, and tumor location and extension, were significant prognostic factors for the overall survival (OS) of patients with glioblastoma, who received nimustine (ACNU)-based chemotherapy in association with surgery and radiotherapy. Among them, following multivariate analysis, preoperative KPS, radical surgery, tumor location, and the expression of O(6)-MGMT remained as significant prognostic factors. These findings suggest that immunohistochemical analysis of O(6)-MGMT in patients with glioblastoma can be a useful method to predict the effects of chemotherapy and identify alternative chemotherapeutic regimens for O(6)-MGMT-positive patients.

Melanocytoma in the orbital apex.

We report a case of a 49-year-old man presenting with a melanocytoma located in the orbital apex. The tumor was subtotally removed and adjuvant chemotherapy was given. The patient has remained under follow-up for the past 12 years without any evidence of recurrence. Although the characteristic neuroradiological images of the lesion prove the presence of melanin, histological examination is crucial to establish the diagnosis of melanocytoma. Besides the clinical and neuroradiological presentation, the histological, immunohistochemical, and ultrastructural findings are described. To our knowledge, this is the second published case of intraorbital melanocytoma initially confined to the orbital apex. Melanocytoma should be included in the differential diagnosis of intraorbital tumors in such a location.

Expression of vascular endothelial growth factor-A and mRNA stability factor HuR in human astrocytic tumors.

High-grade astrocytic tumors, such as glioblastoma, possess rich vascular components, which are necessary for their growth. VEGF-A is considered to be the major mediator of angiogenesis in malignant neoplasms including high-grade astrocytic tumors. The upregulation of VEGF-A expression in tumor cells is induced by two mechanisms: the transcriptional activation and the post-transcriptional stabilization of VEGF-A mRNA. While the former mechanism mediated by hypoxia inducible factor-1 alpha (HIF-1alpha) has been revealed, the latter mediated by mRNA stability factor HuR remains unclear in astrocytic tumors. In the present study, we investigated the expression of VEGF-A and mRNA stability factor HuR in supratentorial astrocytic tumors of 27 adults using RT-PCR, ELISA, and immunohistochemistry. Furthermore, we studied the involvement of HuR in the upregulation of VEGF-A expression using malignant astrocytoma cell lines. In higher-grade astrocytic tumors, the level of VEGF-A and microvascular density were elevated, cytoplasmic expression of HuR, which potentially means the protection of VEGF-A mRNA from degradation by ribonucleases, appeared, and they were correlated positively. In in vitro experiments, the inhibition of the cytoplasmic translocation of HuR protein by leptomycin B (LMB) reduced the upregulation of VEGF-A expression in malignant astrocytic tumor cells under hypoxic conditions. These findings suggest that the expression of VEGF-A and cytoplasmic translocation of HuR relates to the histological grade, and that HuR is involved in the upregulation of VEGF-A expression, in human astrocytic tumors.

Expression of vascular endothelial growth factor-A and mRNA stability factor HuR in human meningiomas.

We studied the expression of vascular endothelial growth factor-A (VEGF-A) and mRNA stability factor HuR in 40 supratentorial meningiomas using RT-PCR, ELISA and immunohistochemistry, and analyzed their associations with the clinicopathological characteristics, including microvascular density (MVD), peritumoral brain edema (PTBE), histological subtypes and grades, and the performance of preoperative arterial embolization. Furthermore, we investigated the involvement of HuR in the upregulation of VEGF-A expression using primary meningioma cell cultures. The level of VEGF-A is elevated in meningiomas with PTBE and in higher grade meningiomas. Preoperative arterial embolization did not significantly increase the level of VEGF-A, but it did increase the expression of HuR in tumor tissues. HuR expression was correlated positively with VEGF-A expression in meningioma tissues. In in vitro experiments, hypoxia induced the upregulation of VEGF-A expression and the cytoplasmic translocation of HuR protein in meningioma cells, and inhibition of the cytoplasmic translocation of HuR reduced the upregulation of VEGF-A expression in meningioma cells. These findings suggest that the expression of VEGF-A relates to the development of PTBE with meningiomas and the histological grade, and that HuR is involved in the upregulation of VEGF-A expression in human meningiomas.