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  • Author or Editor: Nathaniel L. Whitney x
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Nathaniel L. Whitney and Nathan R. Selden

Object

The authors describe a method of securing an external ventricular drain (EVD) to prevent dislodgement and discourage CSF leakage and infection.

Methods

The EVD is secured using a single permanent suture, creating a box stitch around the exit site attached to a modified roman sandal. Multiple knots are tied after each loop to avoid “telescoping,” loosening, and pullout.

Results

In 12 years of high-volume pediatric practice by one of the authors, only one drain has broken, and none have pulled out.

Conclusions

The modified roman sandal technique tightly secures EVDs against pullout. Anecdotal evidence suggests that the strength of the suture construct securing the drain is greater than that of the drain tubing itself.

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Eric M. Thompson, Nathaniel L. Whitney, Y. Jeffrey Wu and Edward A. Neuwelt

Object

Hypoxia induces an aggressive phenotype in some brain tumors in part due to hypoxia-inducible factor–1α (HIF-1α) and integrin expression. The importance of hypoxia in medulloblastoma is unclear and the interaction of HIF-1α and c-Myc in medulloblastoma has not been explored. The objective of this study was to determine if hypoxia induces an aggressive phenotype in human medulloblastoma cells that constitutively express high (D283 Med) or low (DAOY) levels of c-Myc and to determine if blocking αv integrins with the monoclonal antibody intetumumab inhibits hypoxia-induced cellular stress responses.

Methods

Cells were grown at 21% and 1% O2 and in the presence or absence of intetumumab. Measures of malignancy evaluated included cell proliferation, cell migration, and expression of vascular endothelial growth factor (VEGF), αv integrins, HIF-1α, and c-Myc.

Results

Both cell lines robustly expressed αv integrins. Hypoxic DAOY cells showed significantly increased proliferation compared with normoxic controls (p < 0.05), whereas D283 Med cells did not. Both cell lines exhibited a dose-dependent decrease in proliferation when treated with intetumumab (p < 0.05). Hypoxia did not increase DAOY migration, but intetumumab significantly inhibited migration at both oxygen conditions (p < 0.05). Intetumumab significantly decreased VEGF levels in DAOY cells at both oxygen conditions (p < 0.05) and in normoxic D283 cells (p < 0.01). Neither cell line demonstrated increased HIF-1α expression in response to hypoxia. However, hypoxic D283 Med cells grown in the presence of intetumumab demonstrated significantly decreased c-Myc expression (p < 0.05).

Conclusions

Hypoxia did not clearly induce a more aggressive phenotype in medulloblastoma cells. Despite this result, intetumumab decreased medulloblastoma cell proliferation and migration and variably decreased VEGF and c-Myc expression in hypoxic conditions. Targeting αv integrins represents a promising potential adjuvant modality in the treatment of medulloblastoma, particularly subtypes that metastasize and overexpress VEGF and c-Myc.