Joon-Khim Loh

The conditional probabilities of survival in patients with anaplastic astrocytoma or glioblastoma multiforme

BACKGROUND By the use of conditional probabilities of survival, we studied the yearly survival rates for individual tumor survivors. METHODS Conditional survival rate was estimated in 114 consecutive patients with anaplastic astrocytoma or glioblastoma multiforme. Conditional probabilities of surviving some years given survival to a specific period of time after craniotomy and 95% confidence intervals were calculated in the individual tumor survivors. RESULTS The estimated median survival was 30 months for 45 patients with anaplastic astrocytoma and 12 months for 69 patients with glioblastoma multiforme. The conditional probabilities of surviving next one year given survival to 1 year, 2 years, 3 years, 4 years, or 5 years after craniotomy for anaplastic astrocytoma were 86.2%, 75.0%, 85.9%, 77.8%, or 85.7%, respectively; for glioblastoma multiforme 64.8%, 58.7%, 85.7%, 80.0%, or 75.0%, respectively. The conditional probability of surviving to 5 years given survival to 2 years after craniotomy for anaplastic astrocytoma, i.e., surviving an additional 3 years, was 50.1%, which was better than observed 5-year survival rate (28.6%); for glioblastoma multiforme it was 40.2%, which also was better than observed 5-year survival rate (12.4%). CONCLUSIONS The conditional probability of survival was a good method to clinically predict yearly survival rate for individual tumor survivors. In addition, the method can estimate the probabilities of surviving next some years given survival to a specific period of time after craniotomy. It also showed a more encouraging result than observed survival rate in patients with supratentorial malignant astrocytomas.

GSK3beta-Mediated Drp1 Phosphorylation Induced Elongated Mitochondrial Morphology against Oxidative Stress

Multiple phosphorylation sites of Drp1 have been characterized for their functional importance. However, the functional consequence of GSK3beta-mediated phosphorylation of Drp1 remains unclear. In this report, we pinpointed 11 Serine/Threonine sites spanning from residue 634∼736 of the GED domain and robustly confirmed Drp1 Ser693 as a novel GSK3beta phosphorylation site. Our results suggest that GSK3beta-mediated phosphorylation at Ser693 does cause a dramatic decrease of GTPase activity; in contrast, GSK3beta-mediated phosphorylation at Ser693 appears not to affect Drp1 inter-/intra-molecular interactions. After identifying Ser693 as a GSK3beta phosphorylation site, we also determined that K679 is crucial for GSK3beta-binding, which strongly suggests that Drp1 is a novel substrate for GSK3beta. Thereafter, we found that overexpressed S693D, but not S693A mutant, caused an elongated mitochondrial morphology which is similar to that of K38A, S637D and K679A mutants. Interestedly, using H89 and LiCl to inhibit PKA and GSK3beta signaling, respectively, it appears that a portion of the elongated mitochondria switched to a fragmented phenotype. In investigating the biofunctionality of phosphorylation sites within the GED domain, cells overexpressing Drp1 S693D and S637D, but not S693A, showed an acquired resistance to H2O2-induced mitochondrial fragmentation and ensuing apoptosis, which affected cytochrome c, capase-3, -7, and PARP, but not LC3B, Atg-5, Beclin-1 and Bcl2 expressions. These results also showed that the S693D group is more effective in protecting both non-neuronal and neuronal cells from apoptotic death than the S637D group. Altogether, our data suggest that GSK3beta-mediated phosphorylation at Ser693 of Drp1 may be associated with mitochondrial elongation via down-regulating apoptosis, but not autophagy upon H2O2 insult.

Acute subdural hematoma in infancy.

BACKGROUND Acute subdural hematoma in infants is distinct from that occurring in older children or adults because of differences in mechanism, injury thresholds, and the frequency with which the question of nonaccidental injury is encountered. The purpose of this study is to analyze the clinical characteristics of acute subdural hematoma in infancy, to discover the common patterns of this trauma, and to outline the management principles within this group. METHODS Medical records and films of 21 cases of infantile acute subdural hematoma were reviewed retrospectively. Diagnosis was made by computed tomography or magnetic resonance imaging. Medical records were reviewed for comparison of age, gender, cause of injury, clinical presentation, surgical management, and outcome. RESULTS Twenty-one infants (9 girls and 12 boys) were identified with acute subdural hematoma, with ages ranging from 6 days to 12 months. The most common cause of injury was shaken baby syndrome. The most common clinical presentations were seizure, retinal hemorrhage, and consciousness disturbance. Eight patients with large subdural hematomas underwent craniotomy and evacuation of the blood clot. None of these patients developed chronic subdural hematoma. Thirteen patients with smaller subdural hematomas were treated conservatively. Among these patients, 11 developed chronic subdural hematomas 15 to 80 days (mean = 28 days) after the acute subdural hematomas. All patients with chronic subdural hematomas underwent burr hole and external drainage of the subdural hematoma. At follow-up, 13 (62%) had good recovery, 4 (19%) had moderate disability, 3 (14%) had severe disability, and 1 (5%) died. Based on GCS on admission, one (5%) had mild (GCS 13-15), 12 (57%) had moderate (GCS 9-12), and 8 (38%) had severe (GCS 8 or under) head injury. Good recovery was found in 100% (1/1), 75% (8/12), and 50% (4/8) of the patients with mild, moderate, and severe head injury, respectively. Sixty-three percent (5/8) of those patients undergoing operation for acute subdural hematomas and 62% (8/13) of those patients treated conservatively had good outcomes. CONCLUSIONS Infantile acute subdural hematoma if treated conservatively or neglected, is an important cause of infantile chronic subdural hematoma. Early recognition and suitable treatment may improve the outcome of this injury. If treatment is delayed or the condition is undiagnosed, acute subdural hematoma may cause severe morbidity or even fatality.

Factors influencing seizures in adult patients with supratentorial astrocytic tumors

SummarySeizures and epilepsy in adults are important and increasingly common clinical problems. Despite this, the investigation of seizures in adults with astrocytic tumors remains a grey area. The incidence and influencing factors of preoperative and postoperative seizures were evaluated in 101 patients of 45 years or older with supratentorial astrocytic tumors. Preoperative seizures occurred in 14 (14%) patients. Seizures at presentation were significantly correlated with pathological grades of astrocytic tumors (p=0.0318). The risk of seizures at presentation was greatest in patients with well-differentiated astrocytomas as compared with anaplastic astrocytomas (Odds ratio=4.364, p=0.056) or glioblastomas multiforme (Odds ratio=5.673, p=0.007). There was no association of preoperative seizures with age, sex, location or site of the tumors. Postoperative seizures occurred in 18 (18%) patients, including 8 (8/14, 57%) recurrent seizures and 10 (10/87, 12%) late-onset seizures. Postoperative seizures were significantly correlated with the presence of preoperative seizures (p=0.0003). The presence of preoperative seizures was potentially predictive of postoperative seizures when evaluated by logistic regression model (Odds ratio=6.650). Thirteen (72%) of 18 patients with postoperative seizures were associated with tumor recurrence in 7 cases, hemorrhage in 3 cases and malignant progression in 3 cases. There was no association of postoperative seizures with age, sex, location or site of the tumors, grades of tumors, type of preoperative seizures, duration of preoperative seizures, serum level of anticonvulsant drug, extent of surgery, postoperative radiation or chemotherapy. The patients with preoperative seizures had a higher risk of postoperative seizures and should be carefully monitored. Imaging examination of brain to exclude the possibilities of tumor recurrence or hemorrhage is warrantable in supratentorial astrocytoma patients with postoperative seizures.

The alteration of prostaglandin E2 levels in patients with brain tumors before and after tumor removal.

AbstractBackground. Both experimental and human tumors often synthesize high levels of prostaglandins, most notably prostaglandin E2 (PGE2). This compound may play an important role in tumor growth and immunosuppression. Little is known of the production of PGE2 by brain tumors. The present study was designed to investigate the levels of PGE2 in the plasma of human brain tumors before and after tumor removal. Methods. The plasma PGE2 levels of brain tumors before and after tumor removal were measured by high-performance liquid chromatography (HPLC). Results. There is a significantly high concentration of PGE2 in malignant brain tumor before tumor removal. Significantly decrease of PGE2 concentration after total removal of the tumor was found both in the malignant and benign brain tumor groups (P=0.0001 and P=0.0039 respectively). However, compared to the control group, only malignant brain tumor showed a significant decrease of PGE2 concentration after tumor removal (P=0.0009). Conclusion. Our study demonstrates the malignant brain tumor synthesized higher relative proportions of PGE2 and surgical removal of the brain tumor can reduce the production of PGE2.

Differential expression of centrosomal proteins at different stages of human glioma

BackgroundHigh-grade gliomas have poor prognosis, requiring aggressive treatment. The aim of this study is to explore mitotic and centrosomal dysregulation in gliomas, which may provide novel targets for treatment.MethodsA case-control study was performed using 34 resected gliomas, which were separated into low- and high-grade groups. Normal human brain tissue was used as a control. Using immunohistochemical analysis, immunofluorescent microscopy, and RT-PCR, detection of centrins 1 and 2, γ-tubulin, hNinein, Aurora A, and Aurora B, expression was performed. Analysis of the GBM8401 glioma cell line was also undertaken to complement the in vivo studies.ResultsIn high-grade gliomas, the cells had greater than two very brightly staining centrioles within large, atypical nuclei, and moderate-to-strong Aurora A staining. Comparing with normal human brain tissue, most of the mRNAs expression in gliomas for centrosomal structural proteins, including centrin 3, γ-tubulin, and hNinein isoforms 1, 2, 5 and 6, Aurora A and Aurora B were elevated. The significant different expression was observed between high- and low-grade glioma in both γ-tubulin and Aurora A mRNA s. In the high-grade glioma group, 78.6% of the samples had higher than normal expression of γ-tubulin mRNA, which was significantly higher than in the low-grade glioma group (18.2%, p < 0.05).ConclusionsMarkers for mitotic dysregulation, such as supernumerary centrosomes and altered expression of centrosome-related mRNA and proteins were more frequently detected in higher grade gliomas. Therefore, these results are clinically useful for glioma staging as well as the development of novel treatments strategies.

Spontaneous Intracerebral Hemorrhage in Children

We reviewed our experience in 42 children younger than 16 years with spontaneous intracerebral hemorrhage (ICH) treated between January 1989 and December 1997. Glasgow coma scale (GCS) on admission was 15 in 21 (50%) patients. The most frequent presenting symptoms were headache in 28 (67%) patients, followed by loss of consciousness in 22 (52%) patients and vomiting in 21 (50%) patients. Three cases were diagnosed initially as meningitis and two cases as common cold. The locations of ICH were lobar (26 patients) and cerebellar (7). Cerebral angiographies were performed on 28 patients, and were diagnostic in 19 (68%). Magnetic resonance imaging (MRI) scans revealed two cases of cavernous angiomas, which were confirmed by the pathologic studies of surgical specimens. Laboratory examinations detected two cases of acute leukemia. Four categories of the causes of ICH were determined in 23 (55%) patients. The leading cause of bleeding was arteriovenous malformations (AVMs). The in-hospital survival rate of all patients in this study was 79%. Patients with GCS 3-5 on admission and ICH located at brain stem, cerebellum, and multiple subcortical areas had higher mortality rates. On the follow-up (mean 42 months), seventy percent of our cases had made a good recovery, 21% a fair recovery, 3% a poor recovery, and 6% had died. Children with ICH recover motor function more rapidly than adults. However, visual deficits always persist at our long-term follow-up examinations. A physician should keep in mind the diagnosis of ICH in children, even though the presenting symptoms may be non-specific and the incidence of ICH is very low in children.

GSK3β regulates Bcl2L12 and Bcl2L12A anti-apoptosis signaling in glioblastoma and is inhibited by LiCl

BCL2L12 has been reported to be involved in post-mitochondrial apoptotic events in glioblastoma, but the role of BCL2L12A, a splicing variant of BCL2L12, remains unknown. In this study, we showed that BCL2L12 and BCL2L12A were overexpressed in glioblastoma multiforme (GBM). Large-scale yeast two-hybrid screening showed that BCL2L12 was a GSK3b binding partner in a testis cDNA library. Our data demonstrated that GSK3b interacts with BCL2L12 but not BCL2L12A, whose C terminus lacks a binding region. We found that a BCL2L12153–191 fragment located outside of the C-terminal BH2 motif is responsible for GSK3b binding. In contrast, no interaction was detected between BCL2L12A and GSK3b. In vitro kinase and l-phosphatase assays showed that GSK3b phosphorylates BCL2L12 at S156, while this site is absent on BCL2L12A. Moreover, our data also showed that the BCL2L12153–191 fragment directly interrupted GSK3bmediated Tau phosphorylation in a dose-dependent manner. Ectopic expression of GFP-fused BCL2L12 or BCL2L12A in U87MG cells leads to repression of apoptotic markers and protects against staurosporine (STS) insults, indicating an antiapoptotic role for both BCL2L12 and BCL2L12A. In contrast, no anti-apoptotic ability was seen in BCL2L12(S156A). When BCL2L12-expressing U87MG cells were co-administrated with STS and LiCl, cells underwent apoptosis. This effect could be reversed by LiCl. In short, we established a model to demonstrate that GSK3b interacts with and phosphorylates BCL2L12 and might also affect BCL2L12A to modulate the apoptosis signaling pathway in glioblastoma. These findings suggest that LiCl may be a prospective therapeutic agent against GBM.

Primary spinal tumors in children

Nine patients, 16 years of age or younger with primary spinal cord tumors, diagnosed between 1991 and 2003 at The Kaohsiung University Hospital, were reviewed retrospectively. There were 2 female and 7 male patients. Two tumors were located primarily in the cervical cord (1 meningioma, 1 neurofibroma), five were predominantly thoracic (1 lymphoma, 1 meningioma, 1 astrocytoma, 1 fibrosarcoma and 1 osteoblastoma), one lumbar (ependymoma), and one sacral (Ewings sarcoma). The most common clinical presentation was limb weakness (100%) followed by back pain (44.4%). All the patients underwent laminectomy for removal of their tumors. Five children with benign tumors improved postoperatively. At discharge, these 5 children could walk without assistance and have remained stable with long-term of follow-up. Radical surgery should be considered in benign primary spinal cord tumors. As would be expected, patients diagnosed and treated early and in whom a total resection was achieved had a better prognosis.

Effect of Aspirin and Indomethacin on Prostaglandin E2 Synthesis in C6 Glioma Cells

Prostaglandin E2 (PGE2) plays an important role in immunosuppression and tumor growth. PGE2 inhibitors such as aspirin and indomethacin suppress experimental tumor growth. Little is known of the relationship between PGE2 synthesis in brain tumors and the dose of aspirin or indomethacin. The present study was undertaken to evaluate the effect of different doses of aspirin and indomethacin on PGE2 synthesis in C6 glioma cells. C6 glioma cells were incubated with different concentrations (2, 4, and 8 μM) of aspirin and indomethacin for 1, 2, 4, 6, 8, 12, and 24 hours. Intracellular PGE2 concentration was measured by enzyme immunoassay. Each concentration of aspirin and indomethacin effectively inhibited PGE2 synthesis. Concentrations of 2, 4, and 8 μM of aspirin significantly inhibited PGE2 production at 6, 4, and 1 hours, respectively, and the inhibition persisted for more than 24 hours (p < 0.05). Concentrations of 2 and 4 μM of indomethacin were effective at 4 and 2 hours (p < 0.05), respectively. However, inhibition was not observed beyond 12 hours (p > 0.05). Indomethacin 8 μM was effective at 1 hour and the inhibition persisted beyond 24 hours (p < 0.05). Our study demonstrates that aspirin and indomethacin inhibit PGE2 synthesis in C6 glioma cells and that low‐dose aspirin is as effective as high‐dose aspirin. This study may encourage future clinical use of low‐dose aspirin in the prevention or treatment of brain tumors.