Nicholas M. Boulis

Use of factor IX complex in warfarin-related intracranial hemorrhage.

OBJECTIVE Anticoagulation-treated patients presenting with intracranial hemorrhage, including subdural hematoma, epidural hematoma, subarachnoid hemorrhage, and intracerebral hemorrhage, require urgent correction of their coagulopathy to prevent worsening hemorrhage and to facilitate surgical intervention when necessary. In this study, we compared the use of fresh frozen plasma (FFP) with that of Factor IX complex concentrate (FIXCC) to achieve rapid correction of warfarin anticoagulation. METHODS Patients admitted to a tertiary care center with computed tomography-proven intracranial hemorrhage and a prothrombin time of more than 17 seconds were considered for inclusion in the study protocol. Complete data sets were obtained for eight patients randomized to treatment with FFP and five patients randomized to treatment with FFP supplemented with FIXCC. The prothrombin time and International Normalized Ratio were measured every 2 hours for 14 hours. Correction of anticoagulation was defined as an International Normalized Ratio of < or =1.3. RESULTS A difference in repeated International Normalized Ratio measurements during the first 6 hours of correction was observed between the FIXCC and FFP groups (P < 0.03). The rate of correction was greater (P < 0.01) and the time to correction was shorter (P < 0.01) for the FIXCC-treated group. No difference in neurological outcomes was detected between groups, but a higher complication rate was observed for the FFP-treated group. CONCLUSION The use of FIXCC accelerated correction of warfarin-related anticoagulation in the presence of intracranial hemorrhage.

Intracerebral hemorrhage-induced neuronal death.

OBJECTIVEThe mechanisms underlying neural injury in intracerebral hemorrhage (ICH) remain uncertain. The present two-part study investigated cell death in the region of ICH and its association with caspase-3 activation. METHODSICH was produced in adult rats by injection of 100 &mgr;l of autologous blood or saline into the right basal ganglia. The animals’ brains were removed at 6 hours or at 1, 3, 7, or 14 days after hemorrhage. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin in situ nick end-labeling (TUNEL) was used to detect deoxyribonucleic acid (DNA) fragmentation. TUNEL-positive cells were quantified. Caspase-3 activation was measured by Western blotting and immunohistochemistry. Double labeling was used to compare TUNEL with caspase-3 distribution and to identify the cell types affected. TUNEL-positive cells were also quantified at 6 hours, 1 day, and 3 days after injection of 5 U of thrombin into the right basal ganglion. RESULTSAt 6 hours, TUNEL-positive cells appeared in the ICH model (but not in the saline control brains) and were present for more than 2 weeks after ICH, peaking at 3 days. Western blot analysis revealed that the increase in immunoreactivity for the activated caspase-3 precedes that of DNA fragmentation, peaking at 1 day after ICH and declining thereafter. Immunohistochemistry analysis showed nucleus translocation of caspase-3 after ICH. Double-labeling studies demonstrated that both neurons and astrocytes surrounding the clot were TUNEL-positive. In addition, TUNEL and caspase-3 were colocalized in the same cells. Intracerebral thrombin injection elicited DNA fragmentation similar to that observed after the injection of blood. CONCLUSIONDouble-strand breaks in genomic DNA and induction of caspase-3 were demonstrated adjacent to parenchymal hematoma in the animals’ brains. These results provide evidence that cell loss after ICH is associated with activation of caspase-3.

Characterization of adenoviral gene expression in spinal cord after remote vector delivery.

OBJECTIVES Recent work has established that the remote injection of attenuated adenoviral vectors may result in central nervous system (CNS) gene expression. These studies suggest that virus passes through peripheral nerves into the CNS. The present experiment attempts to characterize this phenomenon systematically. METHODS Spinal cord cells staining for the reporter gene beta-galactosidase were histologically quantified after microinjection of the viral vector Ad5RSVntLacZ into rat footpad, muscle, or sciatic nerve. The effects of injection location, titer, and time, as well as nerve crush and dexamethasone, were examined. RESULTS Sciatic nerve viral vector injection results in significantly higher CNS uptake than intramuscular and subcutaneous injections (P < 0.05). Nerve crush injury caused a time-dependent reduction in spinal cord gene uptake after sciatic nerve adenoviral injection (P < 0.05). Neuronal staining reaches its peak at 6 days after injection (P < 0.002). Peripheral nerve delivery to the CNS increases with augmented titers (P < 0.03). Finally, gene expression is augmented by administration of dexamethasone (P < 0.0001). CONCLUSION Remote adenoviral vector injection represents a potential method for spinal cord gene therapy that avoids any manipulation of CNS tissue.

Epidural abscess: a delayed complication of esophageal stenting for benign stricture

A case of anterior cervical epidural abscess associated with perforation of an endoscopically placed esophageal stent is presented. Although delayed esophageal perforation is a known complication of endoscopic stenting, no cases presenting with epidural abscess have yet been reported. The increasing application of endoscopic stenting for benign esophageal strictures provides greater opportunity for this type of delayed complication.

Delivery of an Adenoviral Vector to the Crushed Recurrent Laryngeal Nerve

Objectives Objectives were to create a model of recurrent laryngeal nerve injury for testing the efficacy of potential therapeutic viral gene therapy vectors and to demonstrate that remote injection of a viral vector does not cause significant additional neuronal injury.

Remote delivery of rAAV-GFP to the rat brainstem through the recurrent laryngeal nerve

Objective To demonstrate that a recombinant adeno‐associated viral vector (rAAV) carrying the gene for green fluorescent protein (GFP) could be delivered to the rat brainstem by remote injection into the recurrent laryngeal nerve.

Remote adenoviral gene delivery to the spinal cord: contralateral delivery and reinjection.

OBJECTIVEThis study characterizes the distribution of adenoviral genes in the spinal cord after viral vector injection into the sciatic nerve. It also evaluates the ability of repeated adenoviral sciatic nerve injections to prolong gene expression in the spinal cord. METHODSRat sciatic nerves were unilaterally coinjected with the retrograde tracer Fluoro-Gold (Fluorochrome, Inc., Denver, CO) and the adenoviral vector Ad5RSVntLacZ. The distribution of adenoviral gene expression in the spinal cord was compared with that of Fluoro-Gold. Next, levels of gene expression in the sciatic nerve and spinal cord were compared after single and repeated injections of Ad5RSVntLacZ. Finally, remote spinal cord gene expression in naive animals was compared with expression in animals that had been pretreated with subcutaneous Ad5RSVntLacZ inoculation. RESULTSViral gene expression was detected in all quadrants of the spinal cord gray matter, whereas Fluoro-Gold was detected only in the ipsilateral ventral horn (n = 5). This remote delivery was blocked by sciatic nerve transection (n = 10). Viral gene expression occurred in the sciatic nerve after both initial and repeated injections, whereas remote gene expression in the spinal cord was observed only after primary sciatic nerve injection (n = 24;P < 0.003). As with repeated sciatic nerve injections, subcutaneous inoculation with Ad5RSVntLacZ blocked subsequent remote spinal cord gene delivery (n = 8;P < 0.05). CONCLUSIONRemote viral gene delivery occurs in neurons without direct sciatic nerve projections but is dependent on intact peripheral nerves. Repeated injections fail to boost spinal cord gene expression, because of immune recognition of reinjected virus.

Somatotropinoma Infarction During Octreotide Therapy Leading to Bilateral Cavernous Sinus Syndrome

The cyclic somatostatin analog, octreotide, forms the mainstay of medical treatment for acromegaly. In addition to lowering circulating growth hormone levels and shrinking tumor size, octreotide may provide symptomatic relief of headaches associated with growth hormone secreting tumors. The majority of reported complications of octreotide therapy are gastrointestinal and metabolic. The present case illustrates the development of acute bilateral cavernous sinus syndrome with loss of eye movement bilaterally during octreotide therapy. Serial MRI examination suggest tumor infarction as the etiology. The symptoms resolved over 2 months as the tumor shrunk in size and growth hormone was dramatically reduced.