Author Correction: Condensin association with histone H2A shapes mitotic chromosomes.

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Condensin association with histone H2A shapes mitotic chromosomes.

Chromosome structure is dynamically regulated during cell division, and this regulation is dependent, in part, on condensin. The localization of condensin at chromosome arms is crucial for chromosome partitioning during anaphase. Condensin is also enriched at kinetochores but its precise role and loading machinery remain unclear. Here we show that fission yeast (Schizosaccharomyces pombe) kinetochore proteins Pcs1 and Mde4--homologues of budding yeast (Saccharomyces cerevisiae) monopolin subunits and known to prevent merotelic kinetochore orientation--act as a condensin 'recruiter' at kinetochores, and that condensin itself may act to clamp microtubule binding sites during metaphase. In addition to the regional recruitment factors, overall condensin association with chromatin is governed by the chromosomal passenger kinase Aurora B. Aurora-B-dependent phosphorylation of condensin promotes its association with histone H2A and H2A.Z, which we identify as conserved chromatin 'receptors' of condensin. Condensin phosphorylation and its deposition onto chromosome arms reach a peak during anaphase, when Aurora B kinase relocates from centromeres to the spindle midzone, where the separating chromosome arms are positioned. Our results elucidate the molecular basis for the spatiotemporal regulation of mitotic chromosome architecture, which is crucial for chromosome partitioning.

Kinetochore geometry defined by cohesion within the centromere.

During cell division microtubules capture chromosomes by binding to the kinetochore assembled in the centromeric region of chromosomes. In mitosis sister chromatids are captured by microtubules emanating from both spindle poles, a process called bipolar attachment, whereas in meiosis I sisters are attached to microtubules originating from one spindle pole, called monopolar attachment. For determining chromosome orientation, kinetochore geometry or structure might be an important target of regulation. However, the molecular basis of this regulation has remained elusive. Here we show the link between kinetochore orientation and cohesion within the centromere in fission yeast Schizosaccharomyces pombe by strategies developed to visualize the concealed cohesion within the centromere, and to introduce artificial tethers that can influence kinetochore geometry. Our data imply that cohesion at the core centromere induces the mono-orientation of kinetochores whereas cohesion at the peri-centromeric region promotes bi-orientation. Our study may reveal a general mechanism for the geometric regulation of kinetochores, which collaborates with previously defined tension-dependent reorientation machinery.

Targeted Temperature Management for Severe Subarachnoid Hemorrhage Using Endovascular and Surface Cooling Systems: A Nonrandomized Interventional Study Using Historical Control.

BACKGROUND: Although targeted temperature management (TTM) may mitigate brain injury for severe subarachnoid hemorrhage (SAH), rebound fever correlates with poor outcomes. OBJECTIVE: To study the effect of endovascular TTM after rewarming from initial surface cooling during a high-risk period for delayed cerebral ischemia. METHODS: We studied patients with World Federation of Neurological Surgeons grade V SAH before and after the introduction of endovascular TTM. Both groups (36 patients each) were treated with TTM at 34 °C with conventional surface cooling immediately after SAH diagnosis, together with emergency aneurysm repair. When rewarmed to 36 °C, around 7 days later, the study group underwent TTM at 36 to 38 °C for 7 days with an endovascular cooling system. The control group was treated with antipyretics. RESULTS: Sex, age, Glasgow Coma Scale score, modified Fisher computed tomography classification, aneurysm location, and treatment methods were not different between the study and control groups. Differences were detected in the incidence of fever >38 °C (13 vs 26 patients, P = .0021), duration of fever >38 °C (4.1 vs 18.8 hours, P = .0021), incidence of vasospasm-related cerebral infarction (17% vs 42%, P = .037), and the likelihood of excellent outcomes (0 and 1 on a modified Rankin Scale) at 6 months (42% vs 17%, P = .037). In endovascular TTM, shivering occurred more frequently in patients with better outcomes, requiring aggressive treatment to avoid fever. CONCLUSION: Endovascular TTM at 36 to 38 °C after surface cooling was feasible and safely performed in patients with severe SAH. Combined TTM for 2 weeks was associated with a lower incidence of vasospasm-related infarction and may improve outcomes.

[Repetition of Helicobacter cinaedi infections during chemotherapy for malignant lymphoma].

A 70-year-old male, who had undergone resection of gastric malignant lymphoma in 1992, presented with cervical lymph node swelling in January 2008. Pathological examination of the lymph node biopsy demonstrated recurrence of malignant lymphoma, and he was treated with the R-CHOP regimen. Although he did not develop fever during the first through third course of R-CHOP, from the fourth course, he repeatedly demonstrated fever over 38°C for about one week after each course of chemotherapy, despite the absence of neutropenia. Helicobacter cinaedi infection was confirmed by blood culture each time. Although it is difficult to diagnose Helicobacter cinaedi infection by the standard culture method, increased numbers of recent reports especially in immunocompromised patients have emphasized the importance of diagnosing Helicobacter cinaedi infection.

Occurrence of paralytic shellfish toxins in Cambodian Mekong pufferfish Tetraodon turgidus: selective toxin accumulation in the skin.

The toxicity of two species of wild Cambodian freshwater pufferfish of the genus Tetraodon, T. turgidus and Tetraodon sp., was investigated. Tetraodon sp. was non-toxic. The toxicity of T. turgidus was localized mainly in the skin and ovary. Paralytic shellfish toxins (PSTs), comprising saxitoxin (STX) and decarbamoylsaxitoxin (dcSTX), account for approximately 85% of the total toxicity. Artificially reared specimens of the same species were non-toxic. When PST (dcSTX, 50 MU/individual) was administered intramuscularly into cultured specimens, toxins were transferred via the blood from the muscle into other body tissues, especially the skin. The majority (92.8%) of the toxin remaining in the body accumulated in the skin within 48h. When the same dosage of tetrodotoxin (TTX) was similarly administered, all specimens died within 3-4h, suggesting that this species is not resistant to TTX. Toxin analysis in the dead specimens revealed that more than half of the administered TTX remained in the muscle and a small amount was transferred into the skin. The presence of both toxic and non-toxic wild specimens in the same species indicates that PSTs of T. turgidus are derived from an exogenous origin, and are selectively transferred via the blood into the skin, where the toxins accumulate.

Prognostic value of epidermal growth factor receptor in patients with glioblastoma multiforme.

Glioblastoma multiforme (GBM) frequently involves amplification and alteration of the epidermal growth factor receptor (EGFR) gene, resulting in overexpression of varied mutations, including the most common mutation, EGFRvIII, as well as wild-type EGFR (EGFRwt). To test the prognostic value of EGFR, we retrospectively analyzed the relationship between treatment outcomes and the EGFR gene in 87 newly diagnosed adult patients with supratentorial GBM enrolled in clinical trials. The EGFR gene status was assessed by Southern blots and EGFR expression by immunohistochemistry using three monoclonal antibodies (EGFR.25 for EGFR, EGFR.113 for EGFRwt, and DH8.3 for EGFRvIII). EGFR amplification was detected in 40 (46%) of the 87 GBM patients; in 39 (97.5%) of these, EGFR was overexpressed. On the other hand, in 46 of 47 patients without EGFR amplification (97.9%), no EGFR overexpression was present. There was a close correlation between EGFR amplification and EGFR overexpression (P < 0.0001). EGFRwt was overexpressed in 27 of the 40 (67.5%) patients with, and in none without, EGFR amplification (P < 0.0001). Similarly, EGFRvIII was overexpressed in 18 (45.0%) of 40 patients with and in 4 (8.5%) of 47 patients without EGFR amplification (P < 0.0001). The finding that 8 (20%) of the patients with EGFR amplification/EGFR overexpression manifested overexpression of neither EGFRwt nor EGFRvIII indicates that they overexpressed other types of EGFR. Multivariate analysis demonstrated that EGFR amplification was an independent, significant, unfavorable predictor for overall survival (OS) in all patients (P = 0.038, HR = 1.67). With respect to the relationship of age to EGFR prognostication, the EGFR gene status was a more significant prognosticator in younger patients, particularly in those <60 years (P = 0.0003, HR = 3.15), whereas not so in older patients. EGFRvIII overexpression, on the other hand, was not predictive for OS. However, in patients with EGFR amplification, multivariate analysis revealed that EGFRvIII overexpression was an independent, significant, poor prognostic factor for OS (P = 0.0044, HR = 2.71). This finding indicates that EGFRvIII overexpression in the presence of EGFR amplification is the strongest indicator of a poor survival prognosis. In GBM patients, EGFR is of significant prognostic value for predicting survival, and the overexpression of EGFRvIII with amplification plays an important role in enhanced tumorigenicity.

Preliminary observations on genetic alterations in pilocytic astrocytomas associated with neurofibromatosis 1.

Neurofibromatosis 1 (NF1) is an autosomal dominant disorder that predisposes sufferers to various forms of neoplasia. Among affected individuals, 15%-20% develop astrocytomas, especially pilocytic astrocytomas (PA), which are benign and classified as grade I by the World Health Organization. They are generally well circumscribed, and their progression is slow. NF1-associated PAs (NF1-PAs) occasionally behave as aggressive tumors. To elucidate underlying genetic events in clinically progressive NF1-PAs, we performed molecular genetic analysis on 12 PAs, including 3 NF1-PAs, for pS3, p16, and epidermal growth factor receptor genes, as well as loss of heterozygosity (LOH) on chromosome 1p, 10, 17, and 19q. None of the obvious genetic alterations typically seen in higher grade astrocytomas were found in 9 sporadic PAs. However, in 2 of 3 NF1-PAs, microsatellite analysis showed LOH10, including the PTEN (phosphatase and tensin homolog deleted on chromosome 10) gene locus, despite the diagnosis of pilocytic astrocytoma;one of these also manifested homozygous deletion of the p16 gene. The other NF1-PA harbored only LOH of the NF1 gene locus (17q). Our preliminary results support the hypothesis that some NF1-PAs differ genetically from sporadic PAs.

Correlation of molecular genetic analysis of p53, MDM2, p16, PTEN, and EGFR and survival of patients with anaplastic astrocytoma and glioblastoma.

This article reviews studies on the correlation between genetic abnormalities in malignant astrocytic tumors and patient survival. It is almost certain that alterations of PTEN on chromosome 10 represent a significant unfavorable prognostic factor in glioblastoma patients. The association of alterations in p53, MDM2, p16 or EGFR with the survival of patients with anaplastic astrocytoma or glioblastoma remains controversial. It is possible that the p16 alteration and EGFR amplification are associated with poor survival in certain groups of patients and that there might be a relationship with age. Malignant transformation of astrocytic cells are driven by the sequential acquisition of genetic alteration. Therefore, it is reasonable to subgroup gliomas by their patterns of genetic alterations. However the studies that correlated the multiple genetic alterations with survival are still limited. Further studies on large cohorts are necessary to elucidate the genetic factors that affect the prognosis and response to therapy of patients with malignant gliomas and to develop effective management strategies.

Correlation between promoter hypermethylation of the O6-methylguanine-deoxyribonucleic acid methyltransferase gene and prognosis in patients with high-grade astrocytic tumors treated with surgery, radiotherapy, and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea-based chemotherapy.

OBJECTIVE: O(6)-Methylguanine-deoxyribonucleic acid methyltransferase (MGMT) is a deoxyribonucleic acid repair protein associated with the chemoresistance of chloroethylnitrosoureas. We investigated whether MGMT promoter hypermethylation is associated with prognosis in patients with high-grade astrocytic tumors treated uniformly with surgery, radiotherapy, and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU)-based chemotherapy. METHODS: Using the methylation-specific polymerase chain reaction, we assayed promoter hypermethylation of the MGMT gene in tumor deoxyribonucleic acid from 116 adult patients with supratentorial high-grade astrocytic tumors (42 anaplastic astrocytomas [AAs] and 74 glioblastomas multiforme [GBMs]). The Cox proportional hazards model was used in forward stepwise regression to assess the relative role of prognostic factors (i.e., age at surgery, sex, Karnofsky Performance Scale score, extent of surgical resection, methylation status of the MGMT promoter, and association between MGMT promoter methylation and survival). RESULTS: MGMT promoter hypermethylation was confirmed in 19 (45.2%) of 42 AA patients and 33 (44.6%) of 74 GBM patients. It was significantly associated with both longer overall and progression-free survival time in AA but not GBM patients. CONCLUSION: Our results demonstrate that MGMT promoter hypermethylation is associated with longer survival time in patients with AA who were treated with surgery, radiotherapy, and ACNU-based chemotherapy but not in patients with GBM.

The influence of sex and the presence of giant cells on postoperative long-term survival in adult patients with supratentorial glioblastoma multiforme.

OBJECT: Glioblastoma multiforme (GBM) remains incurable by conventional treatments, although some patients experience long-term survival. A younger age, a higher Karnofsky Performance Scale (KPS) score, more aggressive treatment, and long progression-free intervals have been reported to be positively associated with long-term postoperative patient survival. The aim of this retrospective study was the identification of additional favorable prognostic factors affecting long-term survival in surgically treated adult patients with supratentorial GBM. METHODS: Of 113 adult patients newly diagnosed with histologically verified supratentorial GBM who were enrolled in Phase III trials during the period between 1987 and 1998, six (5.3%) who survived for longer than 5 years were defined as long-term survivors, whereas the remaining 107 patients served as controls. All six were women and were compared with the controls; they were younger (mean age 44.2 years, range 31-60 years), and their preoperative KPS scores were higher (mean 85, range 60-100). Four of the six patients underwent gross-total resection. In five patients (83.3%) the progression-free interval was longer than 5 years and in three a histopathological diagnosis of giant cell GBM was made. This diagnosis was not made in the other 107 patients. CONCLUSIONS: Among adult patients with supratentorial GBM, female sex and histopathological characteristics consistent with giant cell GBM may be predictive of a better survival rate, as may traditional factors (that is, younger age, good KPS score, more aggressive resection, and a long progression-free interval).

Analysis of homozygous deletion of the p16 gene and correlation with survival in patients with glioblastoma multiforme.

OBJECT: One of the most frequent genetic abnormalities found in patients with glioblastoma multiforme (GBM) is homozygous deletion of the p16 tumor suppressor gene. The authors investigated whether this deletion is associated with prognosis in patients with GBM. METHODS: In 46 adult patients with supratentorial GBM, homozygous deletion of the p16 gene in tumor DNA was examined using the multiplex polymerase chain reaction assay. The deletion was confirmed in 14 (30.4%) of 46 patients, eight (30.8%) of 26 men and six (30.0%) of 20 women. Cox proportional hazard regression analysis, adjusted for age at surgery, the Karnofsky Performance Scale score, extent of resection, and the MIB-1 labeling index. revealed that homozygous deletion of the p16 gene was significantly associated with overall survival and progression-free survival in men, but not in women. CONCLUSIONS: The results of this study suggest that p16 homozygous deletion is a significant unfavorable prognostic factor in male patients with GBM.

Influence of p53 mutations on prognosis of patients with glioblastoma.

BACKGROUND: The influence of p53 mutations on the biology of astrocytic tumors is controversial. p53 is thought to be inactivated in the early stage of gliomagenesis; however, what role its inactivation plays in the malignancy of gliomas remains unknown. To understand the significance of p53 inactivation, the authors identified the locus of p53 gene mutation in glioma samples at different stages of progression and studied the correlation between the mutation and clinical behavior. METHODS: Samples from newly diagnosed gliomas, including pure and mixed astrocytomas, were analyzed for p53 mutations using a yeast functional assay. To determine the locus of the gene mutations, DNA sequencing was performed. RESULTS: The incidence of p53 mutations was higher in anaplastic astrocytomas (AA, 48%) than glioblastomas (GBM, 31%). There was no significant difference in the average ages of GBM patients with and without p53 mutations (54.9 years +/- 2.3 and 53.2 years +/- 4.6, respectively). In GBM patients, the mutation did not affect progression free survival or overall survival. Astrocytomas and GBM differed in the distribution of p53 mutation loci. CONCLUSIONS: The p53 gene mutation does not markedly affect the survival of GBM patients. The difference in the location of p53 mutations between AA and GBM suggests that in gliomas, the p53 mutation may contribute not only to tumorigenesis (as an early event) but also to progression to malignancy (as a late event).

Expression of Hqk encoding a KH RNA binding protein is altered in human glioma.

The quaking gene family encodes single KH domain RNA-binding proteins that play vital roles in cell differentiation, proliferation, and apoptotic processes. The human quaking gene, Hqk, maps to 6q25-q26, where cytogenetic alterations associated with a variety of human malignancies, including gliomas have been reported. To assess possible relationships of Hqk with human diseases such as glial tumors, we first isolated the Hqk gene, characterized its structure and expression pattern, and carried out mutational analysis of Hqk in primary tumor samples. The Hqk gene contains 8 exons spanning a approximately 200 kb genomic region, and generating at least four alternatively spliced transcripts, Hqk-5, Hqk-6, Hqk-7 and Hqk-7B, of which Hqk-7 is abundantly expressed in brain. Analysis of primary tumors demonstrated a high incidence of expression alterations of Hqk in gliomas (30%; 6/20), but not in other tumors such as schwannomas (0/3), or meningiomas (0/8). Among the tumor samples showing expression alterations, two were devoid of all three major transcripts, one was missing only the Hqk-5 message, and only the Hqk-7 message was absent in two cases. Our results thus imply the involvement of Hqk in human glial tumor progression.