Ba Chandramouli

Novel Glioblastoma Markers with Diagnostic and Prognostic Value Identified through Transcriptome Analysis

Purpose: Current methods of classification of astrocytoma based on histopathologic methods are often subjective and less accurate. Although patients with glioblastoma have grave prognosis, significant variability in patient outcome is observed. Therefore, the aim of this study was to identify glioblastoma diagnostic and prognostic markers through microarray analysis. Experimental Design: We carried out transcriptome analysis of 25 diffusely infiltrating astrocytoma samples [WHO grade II—diffuse astrocytoma, grade III—anaplastic astrocytoma, and grade IV—glioblastoma (GBM)] using cDNA microarrays containing 18,981 genes. Several of the markers identified were also validated by real-time reverse transcription quantitative PCR and immunohistochemical analysis on an independent set of tumor samples (n = 100). Survival analysis was carried out for two markers on another independent set of retrospective cases (n = 51). Results: We identified several differentially regulated grade-specific genes. Independent validation by real-time reverse transcription quantitative PCR analysis found growth arrest and DNA-damage–inducible α (GADD45α) and follistatin-like 1 (FSTL1) to be up-regulated in most GBMs (both primary and secondary), whereas superoxide dismutase 2 and adipocyte enhancer binding protein 1 were up-regulated in the majority of primary GBM. Further, identification of the grade-specific expression of GADD45α and FSTL1 by immunohistochemical staining reinforced our findings. Analysis of retrospective GBM cases with known survival data revealed that cytoplasmic overexpression of GADD45α conferred better survival while the coexpression of FSTL1 with p53 was associated with poor survival. Conclusions: Our study reveals that GADD45α and FSTLI are GBM-specific whereas superoxide dismutase 2 and adipocyte enhancer binding protein 1 are primary GBM-specific diagnostic markers. Whereas GADD45α overexpression confers a favorable prognosis, FSTL1 overexpression is a hallmark of poor prognosis in GBM patients.

PBEF1/NAmPRTase/Visfatin: A potential malignant astrocytoma/glioblastoma serum marker with prognostic value

Malignant astrocytomas comprise anaplastic astrocytoma (AA; grade III) and Glioblastoma (GBM; grade IV). GBM is the most malignant with a median survival of 10-12 months in patients. Using cDNA microarray based expression profiling of different grades of astrocytomas, we identified several fold increased levels of PBEF1 transcripts in GBM samples. Pre-B-cell colony enhancing factor 1 gene (PBEF1) encodes Nicotinamide phosphoribosyltransferase (NAmPRTase), which catalyses the rate limiting step in the salvage pathway of NAD metabolism in mammalian cells. Further validation using real time RT-qPCR on an independent set of tumor samples (n=91) and normal brain samples (n=9), GBM specific higher expression of PBEF1 was confirmed. Immunohistochemical staining for PBEF1 on a subset of the above samples largely reinforced our finding. We carried out ELISA analysis on serum samples of astrocytoma patients to determine whether this protein levels would correlate with the presence of tumor and tumor grade. PBEF1 serum levels were substantially elevated in many of the AA and GBM patients. Statistical analysis of these data indicates that in patients with astrocytoma, serum PBEF1 levels correlate with tumor grade and is highest in GBM. Immunohistochemical analysis of an independent set of 51 retrospective GBM cases with known survival data revealed that PBEF1 expression in the tumor tissue along with its co-expression with p53 was associated with poor survival. Thus, we have identified PBEF1 as a potential malignant astrocytoma serum marker and prognostic indicator among GBMs.

Proteomic identification of Haptoglobin α2 as a glioblastoma serum biomarker: implications in cancer cell migration and tumor growth

Glioblastoma (GBM; grade IV astrocytoma) is the most malignant and common primary brain tumor in adults. Using combination of 2-DE and MALDI-TOF MS, we analyzed 14 GBM and 6 normal control sera and identified haptoglobin α2 chain as an up-regulated serum protein in GBM patients. GBM-specific up-regulation was confirmed by ELISA based quantitation of haptoglobin (Hp) in the serum of 99 GBM patients as against lower grades (49 grade III/AA; 26 grade II/DA) and 26 normal individuals (p = 0.0001). Further validation using RT-qPCR on an independent set (n = 78) of tumor and normal brain (n = 4) samples and immunohistochemcial staining on a subset (n = 42) of above samples showed increasing levels of transcript and protein with tumor grade and were highest in GBM (p = <0.0001 and <0.0001, respectively). Overexpression of Hp either by stable integration of Hp cDNA or exogenous addition of purified Hp to immortalized astrocytes resulted in increased cell migration. RNAi-mediated silencing of Hp in glioma cells decreased cell migration. Further, we demonstrate that both human glioma and mouse melanoma cells overexpressing Hp showed increased tumor growth. Thus, we have identified haptoglobin as a GBM-specific serum marker with a role on glioma tumor growth and migration.

Pediatric Intracranial Meningiomas – Do They Differ from Their Counterparts in Adults?

Aim: Meningiomas are very rare in children comprising only 0.44.1% of pediatric age tumors and only 1.5–1.8% of all intracranial neoplasms. We analyzed the clinical, pathological and management profile of these rare tumors and elucidated their differences from meningiomas in adults. Methods: From 1990 to 2005, 33 patients belonging to the pediatric age group with intracranial meningiomas were treated in NIMHANS. Results: There were 19 male and 14 female children. The duration of symptoms ranged from 1 to 60 months. The study had a mean follow-up of 23.4 months. The commonest presenting symptoms were headache (90.9%) and visual disturbances (51.5%). Three patients had associated neurofibromatosis. Calcification was noticed in 22% of the tumors. Intraventricular meningiomas were the commonest (24.2%). Gross total or near total resection was possible in 22 out of 33 patients. Nine patients had reversible postoperative motor deficits. Fibrous meningioma was the commonest histological subtype (24.2%). Five patients had atypical or anaplastic subtypes. Adjuvant radiotherapy was administered in 4 patients. Six patients had recurrences and underwent surgery. Ten patients required either staged procedures or multiple surgeries for the recurrence/residual tumors. Conclusion: Pediatric meningiomas are rare tumors and differ from those in adults by their male predominance, atypical locations, higher rates of malignant subtypes, recurrence and association with neurofibromatosis. Surgical management is challenging because of atypical location.

Pediatric Supratentorial Subdural Empyemas: A Retrospective Analysis of 65 Cases

Aim: Intracranial subdural empyemas (SDEs), the majority of which are supratentorial in location, are common neurosurgical emergencies in developing countries, especially in the pediatric age group. They result in significant morbidity and mortality despite improvements in neuroimaging, surgical techniques and antibiotic therapy. In the present study, we retrospectively analyze our experience with operated cases of intracranial supratentorial SDEs in the pediatric age group. Patients and Methods: 65 pediatric patients (age ≤18 years) with supratentorial SDEs were treated in our institute between January 1988 and May 2006, and the case records analyzed with respect to clinical, radiological, bacteriological and surgical complications and outcome data. Results: There was a slight male preponderance (55%), with mean age being 9.54 ± 6.43 years (range 3 months to 18 years). Otogenic source was the most common identifiable etiology, followed by postmeningitic and rhinogenic sources. The initial surgical intervention, burr holes (44 patients; 67.7%) and craniotomy (21 patients; 32.3%), varied with individual cases and surgeon preference. Initial craniotomy was associated with lesser repeat procedures, and slightly better clinical outcome. The majority (83.3%) of patients with significant residual requiring repeat surgery were found to have undergone burr hole evacuation initially. The mortality rate in the present series was 10.8%. Follow-up was available for 41 patients (70.7%) with an average follow-up of 10.4 months. 88% of patients showed good outcomes (Glasgow Outcome Scores of 4 or 5) at the latest follow-up. Conclusion: Pediatric supratentorial SDEs, although rapidly fatal if not identified promptly, can be effectively managed with early surgical drainage (preferably craniotomy), eradication of the source, and sensitive broad-spectrum antibiotics (i.v.) with good outcomes.

Is total excision of spinal neurenteric cysts possible

Spinal neurenteric cysts are intradural cystic lesions. These represent a part of the spectrum of developmental anomalies. These are rare lesions. Most of the data in literature is review of case reports. This made us evaluate our results of 23 cases and review the literature. This is a retrospective study of 23 patients managed at our institute over 20 years. The slides were retrieved and histopathological features studied. Twenty patients were less than 30 years old and 21 were males. Follow-up was available for 21 patients with mean duration of 71 months (range 2 months to 23 years). The typical presentation was backache with progressive neurological deficits pertaining to the level. Atypical presentations as acute onset, recurrent episodic events and aseptic meningitis were also noted. The cervicothoracic region was the most common site. 16 patients had cyst in intradural extramedullary plane and seven had intramedullary location. Associated vertebral anomalies as hemivertebrae, Klippel – Feil and spina bifida were noted in seven patients. There were two histological types of cysts with no correlation between the type of cysts and associated vertebral anomalies and extent of outcome. Partial excision though had higher risk of recurrence, was not associated with poorer outcome. Dorsal approach is an acceptable route with reasonably good results for this lesion. Spinal neurenteric cysts present at younger age with varied clinical presentations. These are commonly located intradurally ventral to the cord. Histological types have no effect on the outcome. Total excision is the choice of treatment. However, partial excision is a feasible option in intramedullary lesions and when significant adhesions occur. Although associated with higher risk of recurrence, the outcome is still good in these patients on re-excision.

Apolipoprotein E polymorphism and outcome after mild to moderate traumatic brain injury: A study of patient population in India

BACKGROUND The nature and extent of recovery after traumatic brain injury (TBI) is heterogeneous. Apolipoprotein E (APOE) plays a major role in repair of cell membrane and growth of neurites following injury to cells. Studies done on the western population have shown that the APOE e4 genotype is associated with poor survival following neurotrauma. AIM To explore the association of APOE polymorphism and outcome following TBI in a patient population from a tertiary care hospital exclusive for neurological diseases in south India. PATIENTS AND METHODS Ninety eight patients who sustained mild to moderate TBI (computed tomography (CT) scan brain showing traumatic parenchymal contusions) were the subjects of the study and the study period was from November 2003 to December 2008. APOE polymorphism status was determined by PCR technique using venous blood. Patients were assessed on follow-up with a battery of four neuropsychological tests as well as Glasgow outcome scale. RESULTS Of the 98 patients, 20 (20%) patients had at least one APOE e4 allele. A follow-up of minimum six months was available for 73 patients. None of the 12 patients who had at least one APOE e4 allele had a poor outcome at six-month follow-up whereas 11(18%) patients without an APOE e4 allele had a poor outcome (Fishers Exact test, P=0.192). On the neuropsychological tests, performance of patients with APOE e4 allele did not differ significantly from those without these alleles. CONCLUSION This study does not support the current contention that the presence of APOE e4 allele should have a significant negative effect on the outcome after TBI.

Central nervous system cladosporiosis: An account of ten culture-proven cases

BACKGROUND Central nervous system (CNS) cladosporiosis is a rare infection caused by Cladophialophora bantiana. It has varied presentation and poor outcome. Most of the available data in the literature are reviews of individual case reports. OBJECTIVE To describe the clinical, radiological and mycological features of 10 cases of C. bantiana managed at a single tertiary center. To analyze the various treatment options, factors associated with outcome and to review the relevant literature. MATERIALS AND METHODS This is a retrospective study of 10 patients with CNS cladosporiosis managed at National Institute of Mental Health and Neurosciences from 1979 to 2006. It is a descriptive study. The case records were reviewed for clinical presentation, radiological features, management and outcome. Only those patients in whom the fungus could be isolated on culture were included in the study. RESULTS The age of the patients ranged from three to 42 years. Nine patients presented with features of space-occupying lesion and one patient with chronic meningitis. There were no specific clinical or radiological features. None of patients had impaired immune status. This infection presented as two pathomorphological forms - diffuse meningoencephalitis and focal abscesses. Burr hole tapping and excision are the surgical options. Both patients with burr hole tapping required excision of abscess subsequently. Two out of seven patients with abscess expired compared to all three patients with diffuse meningoencephalitis who expired. Recurrences occurred in four of the five patients following excision of the abscess. Combination antifungal treatment had better result than monotherapy. The outcome was poor with survival of only 50%. CONCLUSIONS Thorough microbiological examination is required to diagnose CNS infection caused by C. bantiana. The outcome is better in patients with abscess. Excision of the abscess followed by combination antifungal therapy results in better outcome. Close follow-up is required due to high risk of recurrence.

Spinal osteochondroma: spectrum of a rare disease

Osteochondromas are the most common benign bone tumor. Although the metaphysial region of long bones is the usual site of these tumors, the vertebrae may be infrequently affected. The presentation may vary from typical compressive myelopathy to radiculopathy or radiculomyelopathy, depending on the site of involvement. The authors present 3 consecutive cases of cervical spine osteochondromas encountered over 3 years at their institution, each different in its site of involvement, presentation, and chosen treatment. The patient in Case 1 had the typical presentation and lesion site, and was treated with a conventional laminectomy. The patient in Case 2 presented with an extensive disease that required complex, staged surgery with spinal fusion and instrumentation. The patient in Case 3 presented with monoradiculopathy and had a facet joint osteochondroma that was successfully treated with a simple partial facetectomy, without laminectomy.

Papillary glioneuronal tumor—evidence of stem cell origin with biphenotypic differentiation

Papillary glioneuronal tumors are newly recognized seizure producing tumors. We report two such cases with immunohistochemical characterization of glial and neuronal components and briefly review literature. Co-localization of glial and neuronal markers was demonstrable on confocal microscopy with expression of stem cell markers (Nestin and CD133) suggesting possible origin from neuroepithelial stem cell with biphenotypic differentiation.