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Nalin Gupta

Publications and source records attributed to Nalin Gupta.

26 records · Page 2Linked to original sources
PubMed2003

Tumour-endothelium interactions in co-culture: coordinated changes of gene expression profiles and phenotypic properties of endothelial cells.

Tumour angiogenesis is a complex process based upon a sequence of interactions between tumour cells and endothelial cells. To model tumour/endothelial-cell interactions, we co-cultured U87 human glioma cells with human umbilical vein endothelial cells (HUVECs). U87 cells induced an 'activated' phenotype in HUVECs, including an increase in proliferation, migration and net-like formation. Activation was observed in co-cultures where cells were in direct contact and physically separated, suggesting an important role for soluble factor(s) in the phenotypic and genotypic changes observed. Expressional profiling of tumour-activated endothelial cells was evaluated using cDNA arrays and confirmed by quantitative PCR. Matching pairs of receptors/ligands were found to be coordinately expressed, including TGFbetaRII with TGFbeta3, FGFRII and cysteine-rich fibroblast growth factor receptor (CRF-1) with FGF7 and FGF12, CCR1, CCR3, CCR5 with RANTES and calcitronin receptor-like gene (CALCRL) with adrenomedullin. Consistent with cDNA array data, immunohistochemical staining of expressed proteins revealed the upregulation of Tie-2 receptor in vitro and in vivo. Our data suggest that tumour-induced activation of quiescent endothelial cells involves the expression of angiogenesis-related receptors and the induction of autocrine growth loops. We suggest that tumour cells release growth factors that induce endothelial cells to express specific ligands and their cognate receptors coordinately.

Angiogenesis Inhibitors↗
PubMed2003

In utero repair of myelomeningocele: experimental pathophysiology, initial clinical experience, and outcomes.

HYPOTHESIS: Experimental work raises the possibility that in utero repair of myelomeningocele (MMC) may improve lower extremity, bladder, and bowel function, ameliorate the Arnold-Chiari malformation, and decrease the need for postnatal shunting. DESIGN: We previously developed fetal lamb models to create and reverse lower extremity damage and the Arnold-Chiari malformation in utero. We then applied our extensive experience with fetal surgery, including fetal endoscopic (fetoscopic) surgical manipulation, to develop techniques for MMC repair. SETTING: A tertiary referral center. PATIENTS: All patients treated between 1998 and 2002 for a prenatally diagnosed MMC. INTERVENTIONS: Either fetoscopic MMC repair, fetoscopic patch repair, or limited maternal hysterotomy and microsurgical 3-layered fetal MMC repair was performed. MAIN OUTCOME MEASURES: Gestational age at delivery, survival, neurologic outcome, and need for ventricular shunting at 1 year. RESULTS: Complete fetoscopic repair was accomplished in 1 fetus. Two other fetuses underwent partial fetoscopic procedures. The remaining 10 patients underwent limited maternal hysterotomy and microsurgical 3-layered fetal MMC repair. Four of 13 patients died, and the mean gestational age at delivery of 11 fetuses born alive was 31 weeks. Five of 9 required ventricular shunting by age 1 year. In 2 patients, lower extremity function improved by more than 2 vertebral levels compared with prenatal ultrasonography. Five of 10 patients who lived longer than 3 weeks required postnatal wound revision within 7 days after birth. CONCLUSIONS: Fetoscopic repair, although feasible, does not yet yield optimal surgical results. Open surgical repair before 22 weeks' gestation is physiologically sound and technically feasible. One third of patients appear to be spared the need for a shunt at age 1 year, but improvement in distal neurologic function is less clear. Additionally, fetal mortality is associated with this procedure. Our results complement the data published by groups at Children's Hospital of Philadelphia, in Pennsylvania, and Vanderbilt University, Nashville, Tenn. A National Institutes of Health-sponsored prospective randomized trial is now underway at these 3 centers to compare fetal repair with postnatal repair.

Adult↗
PubMed2003

Choroid plexus tumors in children.

Choroid plexus tumors represent a well-defined subset of brain tumors that occur mainly in young children. Surgical resection for papilloma is usually curative, although careful surgical planning is required to minimize the potential risks. Although adjunctive therapy for carcinoma includes chemotherapy or radiation, the long-term survival for carcinoma remains poor.

Child↗
PubMed2003

Cystic schwannoma of the anterior tentorial hiatus. Case report and review of the literature.

Intracranial schwannomas not arising from the facial, trigeminal, or vestibular nerves in the absence of neurofibromatosis are extremely rare. We report a case of a schwannoma arising in the region of the anterior tentorial hiatus and posterior cavernous sinus. A 17-year old girl presented with headaches and intermittent diplopia. An MRI of the brain revealed a heterogeneously enhancing mass adjacent to the free edge of the tentorium, superior to the cerebellopontine angle. An orbitozygomatic pterional craniotomy was done with complete resection of the tumor. Postoperatively, the patient remained neurologically intact. The clinical presentation and treatment of schwannomas arising in this location are discussed.

Adolescent↗
PubMed2003

Brain mapping for hemispheric tumors in children.

Hemispheric tumors are common in children. Pathologically, they range from indolent low grade astrocytic tumors to high grade malignant neoplasms. In general, the extent of resection correlates favorably with survival. Advances in technology are permitting surgical resection to be extended to near eloquent and eloquent regions of the brain. These techniques include advanced neuronavigation, brain mapping, and intra-operative MRI scanners. Incorporation of functional information in surgical planning should lead to safer surgical procedures with improvements in patient outcome.

Brain Mapping↗
PubMed2003

Human neurobrucellosis with intracerebral granuloma caused by a marine mammal Brucella spp.

We present the first report of community-acquired human infections with marine mammal-associated Brucella spp. and describe the identification of these strains in two patients with neurobrucellosis and intracerebral granulomas. The identification of these isolates as marine mammal strains was based on omp2a sequence and amplification of the region flanking bp26.

Adolescent↗
PubMed2002

Spinal cord mapping as an adjunct for resection of intramedullary tumors: surgical technique with case illustrations.

OBJECTIVE: Resection of intramedullary spinal cord tumors may result in transient or permanent neurological deficits. Intraoperative somatosensory evoked potentials (SSEPs) and motor evoked potentials are commonly used to limit complications. We used both antidromically elicited SSEPs for planning the myelotomy site and direct mapping of spinal cord tracts during tumor resection to reduce the risk of neurological deficits and increase the extent of tumor resection. METHODS: In two patients, 3 and 12 years of age, with tumors of the thoracic and cervical spinal cord, respectively, antidromically elicited SSEPs were evoked by stimulation of the dorsal columns and were recorded with subdermal electrodes placed at the medial malleoli bilaterally. Intramedullary spinal cord mapping was performed by stimulating the resection cavity with a handheld Ojemann stimulator (Radionics, Burlington, MA). In addition to visual observation, subdermal needle electrodes inserted into the abductor pollicis brevis-flexor digiti minimi manus, tibialis anterior-gastrocnemius, and abductor halluces-abductor digiti minimi pedis muscles bilaterally recorded responses that identified motor pathways. RESULTS: The midline of the spinal cord was anatomically identified by visualizing branches of the dorsal medullary vein penetrating the median sulcus. Antidromic responses were obtained by stimulation at 1-mm intervals on either side of the midline, and the region where no response was elicited was selected for the myelotomy. The anatomic and electrical midlines did not precisely overlap. Stimulation of abnormal tissue within the tumor did not elicit electromyographic activity. Approaching the periphery of the tumor, stimulation at 1 mA elicited an electromyographic response before normal spinal cord was visualized. Restimulation at lower currents by use of 0.25-mA increments identified the descending motor tracts adjacent to the tumor. After tumor resection, the tracts were restimulated to confirm functional integrity. Both patients were discharged within 2 weeks of surgery with minimal neurological deficits. CONCLUSION: Antidromically elicited SSEPs were important in determining the midline of a distorted cord for placement of the myelotomy incision. Mapping spinal cord motor tracts with direct spinal cord stimulation and electromyographic recording facilitated the extent of surgical resection.

Child↗