DNA methyltransferase-mediated transcriptional silencing in malignant glioma: a combined whole-genome microarray and promoter array analysis.

Epigenetic inactivation of tumor suppressor genes is a common feature in human cancer. Promoter hypermethylation and histone deacetylation are reversible epigenetic mechanisms associated with transcriptional regulation. DNA methyltransferases (DNMT1 and DNMT3b) regulate and maintain promoter methylation and are overexpressed in human cancer. We performed whole-genome microarray analysis to identify genes with altered expression after RNAi-induced suppression of DNMT in a glioblastoma multiforme (GBM) cell line. We then identified genes with both decreased expression and evidence of promoter CpG island hypermethylation in GBM tissue samples using a combined whole-genome microarray transcriptome analysis in conjunction with a promoter array analysis after DNA immunoprecipitation with anti-5-methylcytidine. DNMT1 and 3b knockdown resulted in the restored expression of 308 genes that also contained promoter region hypermethylation. Of these, 43 were also found to be downregulated in GBM tissue samples. Three downregulated genes with hypermethylated promoters and restored expression in response to acute DNMT suppression were assayed for methylation changes using bisulfite sequence analysis of the promoter region after chronic DNMT suppression. Restoration of gene expression was not associated with changes in promoter region methylation, but rather with changes in histone methylation and chromatin conformation. Two of the identified genes exhibited growth suppressive activity in in vitro assays. Combining targeted genetic manipulations with comprehensive genomic and expression analyses provides a potentially powerful new approach for identifying epigenetically regulated genes in GBM.

Isolated fractures of the atlas in adults.

STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: Treatment options in the management of isolated fractures of the atlas are based on the specific atlas fracture type. It is recommended that isolated fractures of the atlas with an intact transverse atlantal ligament be treated with cervical immobilization alone. It is recommended that isolated fractures of the atlas with disruption of the transverse atlantal ligament be treated with either cervical immobilization alone or surgical fixation and fusion.

Isolated fractures of the axis in adults.

UNLABELLED: FRACTURES OF THE ODONTOID: STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: Type II odontoid fractures in patients 50 years and older should be considered for surgical stabilization and fusion. OPTIONS: Type I, Type II, and Type III fractures may be managed initially with external cervical immobilization. Type II and Type III odontoid fractures should be considered for surgical fixation in cases of dens displacement of 5 mm or more, comminution of the odontoid fracture (Type IIA), and/or inability to achieve or maintain fracture alignment with external immobilization. TRAUMATIC SPONDYLOLISTHESIS OF THE AXIS (HANGMAN'S FRACTURE): STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: Traumatic spondylolisthesis of the axis may be managed initially with external immobilization in most cases. Surgical stabilization should be considered in cases of severe angulation of C2 on C3 (Francis Grade II and IV, Effendi Type II), disruption of the C2--C3 disc space (Francis Grade V, Effendi Type III), or inability to establish or maintain alignment with external immobilization. FRACTURES OF THE AXIS BODY (MISCELLANEOUS FRACTURES): STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: External immobilization is recommended for treatment of isolated fractures of the axis body.

Management of combination fractures of the atlas and axis in adults.

STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: Treatment of atlas-axis combination fractures based primarily on the specific characteristics of the axis fracture is recommended. External immobilization of most C1--C2 combination fractures is recommended. C1--Type II odontoid combination fractures with an atlantodens interval of 5 mm or more and C1--hangman's combination fractures with C2--C3 angulation of 11 degrees or more should be considered for surgical stabilization and fusion. In some cases, the surgical technique must be modified as a result of loss of the integrity of the ring of the atlas.

Os odontoideum.

STANDARDS: There is insufficient evidence to support diagnostic standards. GUIDELINES: There is insufficient evidence to support diagnostic guidelines. OPTIONS: Plain x-rays of the cervical spine (anteroposterior, open-mouth odontoid, and lateral) and plain dynamic lateral x-rays performed in flexion and extension are recommended. Tomography (computed or plain) and/or magnetic resonance imaging of the craniocervical junction may be considered. STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: Patients with os odontoideum, either with or without C1--C2 instability, who have neither symptoms nor neurological signs may be managed with clinical and radiographic surveillance. Patients with os odontoideum, particularly with neurological symptoms and/or signs, and C1--C2 instability may be managed with posterior C1--C2 internal fixation and fusion. Postoperative halo immobilization as an adjunct to posterior internal fixation and fusion is recommended unless successful C1--C2 transarticular screw fixation and fusion can be accomplished. Occipitocervical fusion with or without C1 laminectomy may be considered in patients with os odontoideum who have irreducible cervicomedullary compression and/or evidence of associated occipitoatlantal instability. Transoral decompression may be considered in patients with os odontoideum who have irreducible ventral cervicomedullary compression.

Treatment of subaxial cervical spinal injuries.

UNLABELLED: SUBAXIAL CERVICAL FACET DISLOCATION INJURIES: STANDARDS: There is insufficient evidence to recommend treatment standards. GUIDELINES: There is insufficient evidence to recommend treatment guidelines. OPTIONS: Closed or open reduction of subaxial cervical facet dislocation injuries is recommended. Treatment of subaxial cervical facet dislocation injuries with rigid external immobilization, anterior arthrodesis with plate fixation, or posterior arthrodesis with plate or rod or interlaminar clamp fixation is recommended. Treatment of subaxial cervical facet dislocation injuries with prolonged bedrest in traction is recommended if more contemporary treatment options are not available. SUBAXIAL CERVICAL INJURIES EXCLUDING FACET DISLOCATION INJURIES: STANDARDS: There is insufficient evidence to recommend treatment standards. GUIDELINES: There is insufficient evidence to recommend treatment guidelines. OPTIONS: Closed or open reduction of subluxations or displaced subaxial cervical spinal fractures is recommended. Treatment of subaxial cervical spinal injuries with external immobilization, anterior arthrodesis with plate fixation, or posterior arthrodesis with plate or rod fixation is recommended.

Management of acute central cervical spinal cord injuries.

STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: Intensive care unit (or other monitored setting) management of patients with acute central cervical spinal cord injuries, particularly patients with severe neurological deficits, is recommended. Medical management, including cardiac, hemodynamic, and respiratory monitoring, and maintenance of mean arterial blood pressure at 85 to 90 mmHg for the first week after injury to improve spinal cord perfusion is recommended. Early reduction of fracture-dislocation injuries is recommended. Surgical decompression of the compressed spinal cord, particularly if the compression is focal and anterior, is recommended.

Management of vertebral artery injuries after nonpenetrating cervical trauma.

STANDARDS: There is insufficient evidence to support diagnostic standards. GUIDELINES: There is insufficient evidence to support diagnostic guidelines. OPTIONS: Conventional angiography or magnetic resonance angiography is recommended for the diagnosis of vertebral artery injury after nonpenetrating cervical trauma in patients who have complete cervical spinal cord injuries, fracture through the foramen transversarium, facet dislocation, and/or vertebral subluxation. STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: Anticoagulation with intravenous heparin is recommended for patients with vertebral artery injury who have evidence of posterior circulation stroke. Either observation or treatment with anticoagulation in patients with vertebral artery injuries and evidence of posterior circulation ischemia is recommended. Observation in patients with vertebral artery injuries and no evidence of posterior circulation ischemia is recommended.

Cervical spine immobilization before admission to the hospital.

STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: All trauma patients with a cervical spinal column injury or with a mechanism of injury having the potential to cause cervical spine injury should be immobilized at the scene and during transport by using one of several available methods. A combination of a rigid cervical collar and supportive blocks on a backboard with straps is effective in limiting motion of the cervical spine and is recommended. The long-standing practice of attempted cervical spine immobilization using sandbags and tape alone is not recommended.

Transportation of patients with acute traumatic cervical spine injuries.

STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: Expeditious and careful transport of patients with acute cervical spine or spinal cord injuries is recommended, from the site of injury by the most appropriate mode of transportation available to the nearest capable definitive care medical facility.

Clinical assessment after acute cervical spinal cord injury.

UNLABELLED: NEUROLOGICAL EXAMINATION: STANDARDS: There is insufficient evidence to support neurological examination standards. GUIDELINES: There is insufficient evidence to support neurological examination guidelines. OPTIONS: The American Spinal Injury Association international standards for neurological and functional classification of spinal cord injury are recommended as the preferred neurological examination tool for clinicians involved in the assessment and care of patients with acute spinal cord injuries. FUNCTIONAL OUTCOME ASSESSMENT: STANDARDS: There is insufficient evidence to support functional outcome assessment standards. GUIDELINES: The Functional Independence Measure is recommended as the functional outcome assessment tool for clinicians involved in the assessment and care of patients with acute spinal cord injuries. OPTIONS: The modified Barthel index is recommended as a functional outcome assessment tool for clinicians involved in the assessment and care of patients with acute spinal cord injuries.

Radiographic assessment of the cervical spine in asymptomatic trauma patients.

STANDARDS: Radiographic assessment of the cervical spine is not recommended in trauma patients who are awake, alert, and not intoxicated, who are without neck pain or tenderness, and who do not have significant associated injuries that detract from their general evaluation.

Radiographic assessment of the cervical spine in symptomatic trauma patients.

STANDARDS: A three-view cervical spine series (anteroposterior, lateral, and odontoid views) is recommended for radiographic evaluation of the cervical spine in patients who are symptomatic after traumatic injury. This should be supplemented with computed tomography (CT) to further define areas that are suspicious or not well visualized on the plain cervical x-rays. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: It is recommended that cervical spine immobilization in awake patients with neck pain or tenderness and normal cervical spine x-rays (including supplemental CT as necessary) be discontinued after either a) normal and adequate dynamic flexion/extension radiographs, or b) a normal magnetic resonance imaging study is obtained within 48 hours of injury. Cervical spine immobilization in obtunded patients with normal cervical spine x-rays (including supplemental CT as necessary) may be discontinued a) after dynamic flexion/extension studies performed under fluoroscopic guidance, or b) after a normal magnetic resonance imaging study is obtained within 48 hours of injury, or c) at the discretion of the treating physician.

Initial closed reduction of cervical spine fracture-dislocation injuries.

STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. Early closed reduction of cervical spine fracture-dislocation injuries with craniocervical traction is recommended to restore anatomic alignment of the cervical spine in awake patients. Closed reduction in patients with an additional rostral injury is not recommended. Patients with cervical spine fracture-dislocation injuries who cannot be examined during attempted closed reduction, or before open posterior reduction, should undergo magnetic resonance imaging (MRI) before attempted reduction. The presence of a significant disc herniation in this setting is a relative indication for a ventral decompression before reduction. MRI study of patients who fail attempts at closed reduction is recommended. Prereduction MRI performed in patients with cervical fracture dislocation injury will demonstrate disrupted or herniated intervertebral discs in one-third to one-half of patients with facet subluxation. These findings do not seem to significantly influence outcome after closed reduction in awake patients; therefore, the usefulness of prereduction MRI in this circumstance is uncertain.

Pharmacological therapy after acute cervical spinal cord injury.

STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: Treatment with methylprednisolone for either 24 or 48 hours is recommended as an option in the treatment of patients with acute spinal cord injuries that should be undertaken only with the knowledge that the evidence suggesting harmful side effects is more consistent than any suggestion of clinical benefit. GM-1 GANGLIOSIDE: STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: Treatment of patients with acute spinal cord injuries with GM-1 ganglioside is recommended as an option without demonstrated clinical benefit.

Blood pressure management after acute spinal cord injury.

STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: Hypotension (systolic blood pressure <90 mmHg) should be avoided if possible or corrected as soon as possible after acute spinal cord injury. Maintenance of mean arterial blood pressure at 85 to 90 mmHg for the first 7 days after acute spinal cord injury to improve spinal cord perfusion is recommended.

Deep venous thrombosis and thromboembolism in patients with cervical spinal cord injuries.

STANDARDS: Prophylactic treatment of thromboembolism in patients with severe motor deficits due to spinal cord injury is recommended. The use of low-molecular-weight heparins, rotating beds, adjusted dose heparin, or a combination of modalities is recommended as a prophylactic treatment strategy. Low-dose heparin in combination with pneumatic compression stockings or electrical stimulation is recommended as a prophylactic treatment strategy. GUIDELINES: Low-dose heparin therapy alone is not recommended as a prophylactic treatment strategy. Oral anticoagulation alone is not recommended as a prophylactic treatment strategy. OPTIONS: Duplex Doppler ultrasound, impedance plethysmography, and venography are recommended for use as diagnostic tests for deep venous thrombosis in the spinal cord-injured patient population. A 3-month duration of prophylactic treatment for deep venous thrombosis and pulmonary embolism is recommended. Vena cava filters are recommended for patients who do not respond to anticoagulation or who are not candidates for anticoagulation therapy and/or mechanical devices.

Nutritional support after spinal cord injury.

STANDARDS: There is insufficient evidence to support treatment standards. GUIDELINES: There is insufficient evidence to support treatment guidelines. OPTIONS: Nutritional support of patients with spinal cord injuries is recommended. Energy expenditure is best determined by indirect calorimetry in these patients because equation estimates of energy expenditure and subsequent caloric need tend to be inaccurate.