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Biomedical subjects

Ashok K Mahapatra

Publications and source records attributed to Ashok K Mahapatra.

16 recordsLinked to original sources
PubMed2006

Frequent loss of heterozygosity encompassing the hMLH1 locus in low grade astrocytic tumors.

The mismatch repair genes, hMLH1 (3p22) and hMSH2 (2p21), are commonly associated with accumulation of mutations and microsatellite instability. However, the status of their gene loci itself is often not addressed. In astrocytic tumors, the heterozygosity status of these genes with reference to tumor grade has not yet been determined. We have analyzed the heterozygosity status and locus specific instability in 43 glial tumors comprising 22 low grades diffuses astrocytoma (WHO Grade II, DA) and 21 glioblastoma multiforme (Grade IV GBM) using 10 microsatellite markers at 2p and 3p to elucidate the involvement of these loci in astrocytic tumorigenesis. We observed a significantly higher loss of heterozygosity (LOH) in 3p markers encompassing the hMLH1 gene locus in DA when compared to GBM (P = 0.008). In DA, while the frequency of LOH was observed to be higher in markers close to the hMLH1 gene ( approximately 40%), locus specific microsatellite instability (LSI) was higher ( approximately 30%) in markers localizing further to the gene. The frequency of LOH at markers on 2p, near the hMSH2 gene was, however, similar in DA and GBM (P = 0.451). Our results suggest that in the astrocytic tumorigenesis, LOH at the hMLH1 gene locus is an early event in tumorigenesis. However, the mismatch repair protein expression may be regulated by other cellular factors.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Traumatic middle meningeal artery aneurysm causing intracerebral hematoma: a case report and review of literature.

BACKGROUND: Traumatic aneurysms of middle meningeal artery (MMA) are rare. Traumatic MMA aneurysms usually present with extradural hematomas, whereas intradural intraparenchymal hematomas are exceedingly rare. CASE DISCUSSION: We report a 30-year-old man who presented 1 year after head injury with spontaneous right frontal intraparenchymal hematoma. Investigations revealed a MMA pseudoaneurysm, which was successfully treated surgically. CONCLUSION: Traumatic MMA pseudoaneurysm producing intracerebral hematoma (ICH) is rare and can be listed as a cause of spontaneous acute ICH.

Adult↗
PubMed2005

Terminal myelocystoceles: a series of 17 cases.

OBJECT: A terminal myelocystocele is a rare form of spinal dysraphism in which the hydromyelic caudal spinal cord and the subarachnoid space are herniated through a posterior spina bifida. In their study of 17 cases, the authors attempt to develop treatment guidelines for patients suffering from this condition. METHODS: Seventeen patients (age range 2 months-5 years) underwent surgery during a 7-year period. Surprisingly, nine of 17 patients had no neurological deficits. Among these nine asymptomatic cases, three patients had a dermal sinus and two had a skin dimple, whereas one had congenital talipes equinovarus deformity (CTEV). Among the eight patients with neurological deficits, seven had lower-limb weakness (two had complete paraplegia), and one patient had urinary incontinence and constipation. Four patients each had a dermal sinus and CTEV; interestingly, one infant had an accessory phallus. Radiologically, eight patients had pure myelocystoceles, and a diagnosis of lipomyelocystocele was made in nine instances on the basis of magnetic resonance images. All patients underwent surgery. The meningocele sacs were excised, and the bands tethering the myelocystocele sac to the meningocele sacs were incised, with as little damage to the roots as possible. Two patients experienced postoperative CSF leakage (one required reexploration), and two others had subcutaneous CSF collection. No patient had deterioration of the neurological condition after surgery. CONCLUSIONS: The authors present the largest study of patients with terminal myelocystocele to date and emphasize that the possibility of this condition must be kept in mind when addressing all congenital lumbosacral masses. The authors assert that myelocystoceles and lipomyelocystoceles should be kept in the same category and recommend early surgery in all cases.

Child, Preschool↗
PubMed2005

Split cord malformations: a clinical study of 254 patients and a proposal for a new clinical-imaging classification.

OBJECT: Split cord malformations (SCMs) are rare anomalies of the spinal cord. A total of 254 cases of SCM were treated surgically at the authors' center during a period of 16 years. METHODS: Patients' demographic profiles, imaging studies, operative details, complications, and surgical outcomes were evaluated retrospectively. A new classification based on intraoperative findings is proposed. The mean age of the patients was 7.3 years (female/male 1.5:1). Type I SCM was seen in 156 patients (61.4%) and 98 patients (38.6%) had Type II SCM. Skin stigmata were present in 153 cases (60%); hypertrichosis, being the most common, was seen in 82 cases (32.3%). Asymmetrical lower-limb weakness and sphincter disturbances were present in 173 (68.1%) and 73 (33%) cases, respectively. Of the symptomatic cases, 39% (68 of 173) showed improvement in motor power, 57.9% (33 of 57) experienced sensory improvement, and 27.3% (20 of 73) regained continence. None of the 38 patients in the asymptomatic group had postoperative neurological deterioration. The neurological status was unchanged in 63% of the cases. A new subclassification of Type I SCM is proposed, based on intraoperative location of a bone spur causing the split, which may have a bearing on surgical dissection and outcome. Based on the authors' experience with 25 cases of Type I SCM, they have classified the disorder into four subtypes: Type Ia, bone spur located in the center with duplicated cord above and below the spur (12 cases); Type Ib, bone spur at the superior pole with no space above it (four cases); Type Ic, bone spur at the lower pole with large duplicated cord above (three cases); and Type Id, bone spur straddling the bifurcation with no space above or below the spur (six cases). The risk of injury to the hemicords is highest in the Id subtype (four of six patients in this group deteriorated neurologically in the present series, whereas none with subtypes Ia-c worsened). CONCLUSIONS: The authors present the largest series on SCMs so far reported in the world literature The risk of neurological deficits developing increases with age; hence, all patients with SCM should be surgically treated prophylactically even if they are asymptomatic. This new classification is easy to use and remember and takes into account the use of intraoperative findings that may have a bearing on surgical outcome.

Adolescent↗
PubMed2005

Post operative 'pituitary apoplexy' in giant pituitary adenomas: a series of cases.

This is report on four cases of giant pituitary tumors that developed postoperative pituitary apoplexy after they had undergone a partial tumor resection. Three patients had undergone surgery by a transsphenoid route and one patient underwent surgery by transcranial route. Postoperative CT scan showed hemorrhagic expansion of residual tumor mass. All the four patients were re-explored transcranially and hemorrhagic swelling of the tumor was observed. In three cases, the tumor had swollen to a size greater than twice the original tumor. All the four patients had a fatal outcome.

Adenoma↗
PubMed2003

Loss of heterozygosity of a locus in the chromosomal region 17p13.3 is associated with increased cell proliferation in astrocytic tumors.

We had previously reported that loss of heterozygosity (LOH) of the D17S379 locus on 17p13.3 was significantly more frequent in high-grade gliomas (anaplastic astrocytoma, AA; glioblastoma multiforme, GBM) than in those of a low-grade diffuse astrocytoma (DA); however, this was independent of alterations at the TP53 locus, We also showed that LOH of D17S379 was associated with positive staining for p53 protein on immunohistochemistry, but LOH of the TP53 gene had no such association. In this work we show that cell proliferation as determined by MIB-1 labeling index (LI) was significantly higher in tumors with LOH of D17S379 than those with no LOH (NLOH). In accord with our previous results, p53 protein immunopositivity was also associated with increased MIB-1 LI; however, we observed no such association of LI with TP53 LOH. The results further confirm that alteration of one or more putative tumor suppressor loci at 17p13.3 is associated with increased proliferation in astrocytic tumors.

Adult↗
PubMed2003

Expression of the neurotrophin receptors Trk A and Trk B in adult human astrocytoma and glioblastoma.

Neurotrophins and their receptors of the Trk family play a critical role in proliferation, differentiation and survival of the developing neurons. There are reports on their expression in neoplasms too, namely, the primitive neuroectodermal tumours of childhood, and in adult astrocytic gliomas. The involvement of Trk receptors in tumour pathogenesis, if any, is not known. With this end in view, the present study has examined 10 tumour biopsy samples (identified as astrocytoma, pilocytic astrocytoma and glioblastoma) and peritumoral brain tissue of adult patients, for the presence of Trk A and Trk B receptors, by immunohistochemistry. The nature of the tumour samples was also confirmed by their immunoreactivity (IR) to glial fibrillary acidic protein. In the peritumoral brain tissue, only neurons showed IR for Trk A and Trk B. On the contrary, in the tumour sections, the IR to both receptors was localized in the vast majority of glia and capillary endothelium. There was an obvious pattern of IR in these gliomas: high levels of IR were present in the low-grade (type I and II) astrocytoma; whereas in the advanced malignant forms (WHO grade IV giant cell glioblastoma and glioblastoma multiforme) the IR was very weak. These findings suggest that Trk A and Trk B are involved in tumour pathogenesis, especially in the early stage, and may respond to signals that elicit glial proliferation, and thus contribute to progression towards malignancy.

Adolescent↗
PubMed2002

Trans-sellar trans-sphenoidal encephaloceles: report of two cases.

Trans-sphenoidal encephaloceles are rare entities. Only about 20 such cases have been reported in the world literature to date. Among these, the trans-sellar variety is rarest (five cases). We present two cases of trans-sellar trans-sphenoidal encephaloceles seen over the last 12 years. The first case was a 5 month old male infant presenting with nasal obstruction and a mass in the mouth. The second case was a 14 year old boy presenting with chronic nasal obstruction since early childhood. In the first case, the mass was coming to the mouth through the split palate. In the second case, the mass could be seen in the posterior half of the nose by rhinoscopy. The computed tomography scans including coronal and sagittal reconstructions had revealed trans-sellar trans-sphenoid encephaloceles in both the patients. The magnetic resonance imaging in the second case showed the cavity and the structures of the floor of the third ventricle forming the main fundal contents. The magnetic resonance angiography revealed dipping of the ectatic anterior cerebral arteries in the neck of the encephalocele sac in this case. Extracranial trans-palatal approach and the repair of encephalocele was done in the first case with the palatal reconstruction at the same sitting. In the second patient, a trans-nasal approach with bilateral maxillotomies was performed to repair the encephalocele, and the skull base defect was repaired by a split rib graft, which was fixed with mini-plate and screws posteriorly at the clivus and anteriorly at the anterior edge of the bony defect. The cleft lip and hypertelorism also were corrected at the same sitting. Our first case had CSF leak on the 10th postoperative day and developed fulminant meningitis, despite appropriate antibiotics, and succumbed. The second patient had a good postoperative recovery and a satisfactory follow up for 2 years.

Adolescent↗
PubMed2002

An unusual posterior mediastinal lipoblastoma with spinal epidural extension presenting as a painful suprascapular swelling: case report and a brief review of the literature.

Lipoblastoma is a rare benign pediatric neoplasm of fetal-embryonal fat with little risk of recurrence following total microsurgical excision, but it may progress to local invasion or infiltration if not treated surgically. No adjuvant therapies are usually necessary once the tumor is excised. It is best diagnosed on histopathological studies following excision. An unusual posterior mediastinal lipoblastoma in a 2-year-old Omani girl with spinal epidural extension clinically manifested as a progressive painful suprascapular swelling is reported. It was initially construed to be a benign lipoma, but progressively increasing pain and mild imbalance whilst walking with a tendency to fall on the right side prompted neurosurgical referral and eventual total excision without any added morbidity. Interesting clinical and neuroimaging (CT & MRI) findings are presented and discussed, with a brief review of the literature.

Child, Preschool↗
PubMed2002

Craniospinal giant cell tumors: clinicoradiological analysis in a series of 11 cases.

Primary craniospinal giant cell tumors are rare (5-15% of all giant cell tumors), locally destructive bone lesions which are generally not associated with Paget's disease. Clinical behavior of the craniospinal giant cell tumor (GCT) is unpredictable but often very aggressive and therefore optimal management of the lesions remains controversial. Wide resection of the involved bone is required, preferably with a wide margin of normal tissue, which may be difficult to achieve in the craniospinal region. The authors analysed a series of 11 patients, which included five cases of cranial and six cases of spinal GCTs. Their ages ranged from 12 to 46 years with a male preponderance. In the five cranial cases, all the tumors involved the skull base, three involved the spheno - ethmoidal region and in two cases the petroclival region was involved. Common presenting symptoms were frontotemporal swelling, epistaxis, local pain and neurological deficits attributable to the neurovascular compression. Proptosis, visual loss, nasal mass and cranial nerve involvement were the common findings. In the six patients with spinal lesions (one cervical, four thoracic and one thoracolumbar), local pain, progressive sensory motor deficits and bladder involvement were common presentations. Neuroimaging studies were performed in various combinations for preoperative evaluation and surgical planning. In cranial cases, multidisciplinary approaches were used to perform a near total or a total excision. In the spinal GCTs, only a partial excision was possible. Postoperative radiotherapy was delivered in ten patients. Histopathological studies were diagnostic. All patients were followed up for periods ranging from one to 10 years, with a mean of 2 years and 3 months. No significant increase in the residual tumor or recurrences, as seen on periodic neuroimaging studies, were noted during their follow-up period.

Adolescent↗
PubMed2002

Symptomatic cranial fibrous dysplasias: clinico-radiological analysis in a series of eight operative cases with follow-up results.

Cranial fibrous dysplasias are rare and comprise less than one percent of all primary bone lesions. These painless progressively expanding destructive bone swellings produce cosmetic deformities (commonest), sino-orbital and auditive complications (less common), peripheral compressive cranial neuropathies (uncommon) and compressive central neurological manifestations (rarest). Until recently some of the primary dysplastic skull base lesions were either treated expectantly or excised incompletely. In a significant percentage of cases, these lesions were considered inaccessible. However, with the development of modern neuro-imaging (CT and MRI) and the applications of current skull base approaches, the more aggressive and radical surgical procedures are being undertaken, with a significant improvement in overall outcome. We present a series of 8 cases of fibrous dysplasia in the age group of 10-33 years with a mean age of 19.75 years. Four cases each had monostotic type and polyostotic type. All patients presented with mild to moderate headaches, and seven cases with some form of cosmetic deformity. In 4 patients there was a unilateral proptosis, while only two had visual deterioration. One patient had anosmia and one hearing impairment. In one case fibrous dysplasia was hemicranial, and in another case the disease was pancranial. Neuro-imaging studies have well delineated the extent of the lesions. In two patients with unilateral fronto-orbital fibrous dysplasia, the removal of dysplastic bone, autoclaving and remodeling and replacement were performed. In two patients of sphenoidal wing fibrous dysplasia a total excision was possible. In the remaining four patients, a partial excision was performed. Overall outcome was good. There was no mortality. One patient had recurrent post-operative extradural haematomas. The authors present the results of an analysis of eight surgically treated cases of symptomatic cranial fibrous dysplasias along with their long-term outcome and the lessons learnt from this series.

Adolescent↗
PubMed2002

Orbital tuberculosis with abscess.

The authors present a case of progressive unilateral proptosis caused by tuberculous osteoperiostitis of the orbital walls and sphenoid bone with extraconal orbital and extradural intracranial cold abscess formation. The patient responded well to surgical evacuation and antituberculous medical therapy.

Abscess↗
PubMed2002

Intracranial Salmonella infections: meningitis, subdural collections and brain abscess. A series of six surgically managed cases with follow-up results.

Focal intracranial infections due to Salmonella are rare. So far, around 80 cases have been reported in the world literature. The authors present their experience of 6 cases of intracranial Salmonella infections, mainly subdural empyema in 5 and effusion in 1. In 1 case, subdural empyema was bilateral, and in another case, there was an associated brain abscess. Positive blood cultures and positive Widal tests were noticed in 2 patients each. Early diagnosis and prompt evacuation of subdural collections and brain abscess and antibiotic therapy lead to satisfactory results. This study suggests that a high index of suspicion, early diagnosis and quick evacuation lead to success; this point is highlighted with the help of a review of the literature.

Adult↗