Piceatannol attenuates homocysteine-induced endoplasmic reticulum stress and endothelial cell damage via heme oxygenase-1 expression.

A growing body of evidence implicates endoplasmic reticulum (ER)-induced cellular dysfunction and apoptosis as important factors to a variety of diseases. In endothelial cells (ECs), the sulfur-containing amino acid homocysteine (Hcy) causes EC apoptosis and reactive oxygen species (ROS) generation through induction of ER stress. Here, we have investigated whether piceatannol (Pic), a resveratrol analog, could protect ECs against Hcy-induced apoptosis, oxidative stress and ER stress, with specific emphasis on heme oxygenase-1 (HO-1). In human ECs, we determined the effects of Hcy and Pic on annexin V positivity, glucose-regulated protein 78 kDa (GRP78) and C/EBP homologous protein (CHOP) expression, X-box binding protein 1 (Xbp-1) mRNA slicing, and ROS-sensitive dihydroethidium (DHE) oxidation. Hcy increased annexin V-positive cells, DHE oxidation, GRP78 and CHOP expression and Xbp-1 mRNA splicing, indicating that Hcy induces apoptosis, oxidative stress and ER stress. Pretreatment of ECs with Pic significantly inhibited Hcy-induced apoptosis, ROS generation and ER stress. Pic also increased HO-1 expression via activation of nuclear factor-E2-related factor 2 (Nrf2). Interestingly, the inhibitory effects of Pic on Hcy-induced apoptosis, ROS generation and ER stress were abolished by down-regulation of HO-1 expression, while mimicked by treatment of ECs with the HO-1 inducer hemin. Overall, these results suggest that Pic may protect ECs against Hcy-induced apoptosis, oxidative stress and ER stress via Nrf2-dependent HO-1 expression.

Simple New Screw Insertion Technique without Extraction for Broken Pedicle Screws.

OBJECTIVE: Spinal transpedicular screw fixation is widely performed. Broken pedicle screw rates range from 3%-7.1%. Several techniques have been described for extraction of broken pedicle screws. However, most of these techniques require special instruments. We describe a simple, modified technique for management of broken pedicle screws without extraction. No special instruments or drilling in an adjacent pedicle are required. METHODS: We used a high-speed air drill with a round burr. With C-arm fluoroscopy guidance, the distal fragment of a broken pedicle screw was palpated using free-hand technique through the screw entry hole. A high-speed air drill with a round burr (not a diamond burr) was inserted through the hole. Drilling began slowly and continued until enough space was obtained for new screw insertion. Using this space, we performed new pedicle screw fixation medially alongside the distal fragment of the broken pedicle screw. We performed the insertion with a previously used entry hole and pathway in the pedicle. The same size pedicle screw was used. RESULTS: Three patients were treated with this modified technique. New screw insertion was successful in all cases after partial drilling of the distal broken pedicle screw fragment. There were no complications, such as screw loosening, dural tears, or root injury. CONCLUSION: We describe a simple, modified technique for management of broken pedicle screws without extraction. This technique is recommended in patients who require insertion of a new screw.

Common Carotid Artery Dissection in Multiple Extracranial Injury: A Case Report.

Traumatic common carotid artery dissection (CCAD) is rare. To our knowledge, only 14 case reports have described traumatic CCAD previously. Here, we report a case of CCAD in a patient with severe trauma. A 50-year-old man was lying on the road after drinking alcohol when a car drove over him. Computed tomography (CT) revealed multiple rib fractures with hemopneumothorax, lung contusion, flail chest, large amount of hematoma with bladder rupture, and fractures on the C6 spinous process, sacral ala, iliac bone, and pubic ramus. Repair of the bladder rupture, exploratory thoracotomy, and open reduction of multiple rib fractures were performed. Right side hemiparesis was observed on hospital day 4. Brain CT showed a large acute left middle cerebral artery infarction. CT angiography showed focal carotid dissection at the left common carotid artery with intimal flap. The CCAD was located at the C6 level. Clexane (enoxaparin sodium) treatment was initiated. An abdominal CT scan revealed a huge retroperitoneal hematoma and increased amount of hematoma in the prevesical and perivesical space, 10 days later. The patient died two days later. Although traumatic CCAD is rare, this case report provides useful information for trauma surgeons regarding the treatment and diagnosis of similar cases.

Intermediate Pilomyxoid Astrocytoma in the Cerebellum of a 5-Year-Old Boy.

Intermediate pilomyxoid tumors (IPTs) were defined by the presence of some features typical of pilomyxoid astrocytoma (PMA) in combination with features that could be considered more consistent with pilocytic astrocytoma (PA). PMA is rare in the cerebellum. And, IPT in the cerebellum is rarer than PMA. To our knowledge, only 2 reports have described IPT in the cerebellum. A 5-year-old boy had nausea and vomiting. Computed tomography revealed a large, round, low-density tumor in the cerebellar vermis area. On enhanced magnetic resonance imaging (MRI), the tumor showed inhomogeneous diffuse enhancement; the central portion showed homogenous enhancement, while the peripheral portion showed inhomogeneous enhancement. The patient underwent a midline suboccipital craniotomy, and gross total resection was performed. The tumor was gray-colored, rubbery hard, and severely hemorrhagic with a clear boundary. On pathologic examination, the combined features of both PA and PMA were retrospectively indicative of an IPT. The patient was symptom-free for 18 months, with no evidence of tumor recurrence on MRI. More observation and further studies on PMA and IPT are required to determine the most appropriate treatment for these tumors.

Posterior Epidural Herniation of a Lumbar Disk Fragment at L2-3 That Mimicked an Epidural Hematoma.

Lumbar disk herniation is common. Because of the posterior longitudinal ligament, migration usually occurs into the ventral epidural space. Rarely, fragments migrate into the dorsal epidural space. A 57-year-old man presented with lower back pain and weakness on right hip flexion and right knee flexion. He had lower back pain 1 day previously and received a transforaminal epidural block at a local hospital. The next day, he reported weakness of the right lower extremity. Lumbar spine magnetic resonance imaging revealed a dorsal epidural lesion with compression of the thecal sac at L2-3. Initial differential diagnoses included epidural hematoma after the block, neoplasm, and a sequestrated disk. Posterior lumbar decompression was performed. The lesion was identified intraoperatively as a large herniated disk fragment. Posterior epidural herniation of a lumbar disk fragment is rare and may be difficult to diagnose preoperatively. It may present as a variety of clinical scenarios and, as in this case, may mimic epidural hematoma.

Okanin, a chalcone found in the genus Bidens, and 3-penten-2-one inhibit inducible nitric oxide synthase expression via heme oxygenase-1 induction in RAW264.7 macrophages activated with lipopolysaccharide.

Excess production of nitric oxide by activated macrophages via inducible nitric oxide synthase leads to the development of various inflammatory diseases. Heme oxygenase-1 expression via activation of nuclear factor-erythroid 2-related factor 2 inhibits nitric oxide production and inducible nitric oxide synthase expression in activated macrophages. Okanin is one of the most abundant chalcones found in the genus Bidens (Asteraceae) that is used as various folk medications in Korea and China for treating inflammation. Here, we found that okanin (possessing the α-ß unsaturated carbonyl group) induced heme oxygenase-1 expression via nuclear factor-erythroid 2-related factor 2 activation in RAW264.7 macrophages. 3-Penten-2-one, of which structure, as in okanin, possesses the α-ß unsaturated carbonyl group, also induced nuclear factor-erythroid 2-related factor 2-dependent heme oxygenase-1 expression, while both 2-pentanone (lacking a double bond) and 2-pentene (lacking a carbonyl group) were virtually inactive. In lipopolysaccharide-activated RAW264.7 macrophages, both okanin and 3-penten-2-one inhibited nitric oxide production and inducible nitric oxide synthase expression via heme oxygenase-1 expression. Collectively, our findings suggest that by virtue of its α-ß unsaturated carbonyl functional group, okanin can inhibit nitric oxide production and inducible nitric oxide synthase expression via nuclear factor-erythroid 2-related factor 2-dependent heme oxygenase-1 expression in lipopolysaccharide-activated macrophages.