Cervicogenic headache (CGH) is known to be mainly related with upper cervical problems. In this study, the effect of radiofrequency neurotomy (RFN) for lower cervical (C4-7) medial branches on CGH was evaluated.
Eleven patients with neck pain and headache, who were treated with lower cervical RFN due to supposed lower cervical zygapophysial joint pain without symptomatic intervertebral disc problem or stenosis, were enrolled in this study. CGH was diagnosed according to the diagnostic criteria of the cervicogenic headache international study group. Visual analogue scale (VAS) score and degree of VAS improvement (VASi) (%) were checked for evaluation of the effect of lower cervical RFN on CGH.
The VAS score at 6 months after RFN was 2.7±1.3, which were significantly decreased comparing to the VAS score before RFN, 8.1±1.1 (p<0.001). The VASi at 6 months after RFN was 63.8±17.1%. There was no serious complication.
Our data suggest that lower cervical disorders can play a role in the genesis of headache in addition to the upper cervical disorders or independently.
Cervicogenic headache; Radiofrequency; Neurotomy; Medial branch
We investigated the neuroprotective effect of anthocyanin, oxygen radical scavenger extracted from raspberries, after traumatic spinal cord injury (SCI) in rats.
The animals were divided into two groups : the vehicle-treated group (control group, n=20) received an oral administration of normal saline via stomach intubation immediately after SCI, and the anthocyanin-treated group (AT group, n=20) received 400 mg/kg of cyanidin 3-O-β-glucoside (C3G) in the same way. We compared the neurological functions, superoxide expressions and lesion volumes in two groups.
At 14 days after SCI, the AT group showed significant improvement of the BBB score by 16.7±3.4%, platform hang by 40.0±9.1% and hind foot bar grab by 30.8±8.4% (p<0.05 in all outcomes). The degree of superoxide expression, represented by the ratio of red fluorescence intensity, was significantly lower in the AT group (0.98±0.38) than the control group (1.34±0.24) (p<0.05). The lesion volume in lesion periphery was 32.1±2.4 µL in the control and 24.5±2.3 µL in the AT group, respectively (p<0.05), and the motor neuron cell number of the anterior horn in lesion periphery was 8.3±5.1 cells/HPF in the control and 13.4±6.3 cells/HPF in the AT group, respectively (p<0.05).
Anthocyanin seemed to reduce lesion volume and neuronal loss by its antioxidant effect and these resulted in improved functional recovery.
Spinal cord trauma; Anthocyanin; Antioxidants
There were only a few reports of mercury on pulmonary artery. However, there is no data on surgery related mercury dissemination. The objective of the present article is to describe one case of postoperative injected mercury dissemination. A 19-year-old man presented severe neck pain including meningeal irritation sign and abdominal pain after injection of mercury for the purpose of suicide. Radiologic study showed injected mercury in the neck involving high cervical epidural space and subcutaneous layer of abdomen. Partial hemilaminectomy and open mercury evacuation of spinal canal was performed. For the removal of abdominal subcutaneous mercury, C-arm guided needle aspiration was done. After surgery, radiologic study showed disseminated mercury in the lung, heart, skull base and low spinal canal. Neck pain and abdominal pain were improved after surgery. During 1 month after surgery, there was no symptom of mercury intoxication except increased mercury concentration of urine, blood and hair. We assumed the bone work during surgery might have caused mercury dissemination. Therefore, we recommend minimal invasive surgical technique for removal of injected mercury. If open exposures are needed, cautious surgical technique to prohibit mercury dissemination is necessary and normal barrier should be protected to prevent the migration of mercury.
Bone work; Mercury poisoning; Postoperative complications; Transvascular dissemination
The objectives of this study were to determine the frequency of symptomatic postdiscectomy pseudocyst (PP) after endoscopic discectomy and to compare the results of surgical and conservative management of them.
Initial study participants were 1,503 cases (1,406 patients) receiving endoscopic lumbar discectomy by 23-member board of neurosurgeons from March 2003 to October 2008. All patients' postoperative magnetic resonance imaging (MRI) scans were evaluated. On the postoperative MRI, cystic lesion of T2W high and T1W low at discectomy site was regarded as PP. Reviews of medical records and radiological findings were done. The PP patients were divided into two groups, surgical and conservative management by treatment modality after PP detection. We compared the results of the two groups using the visual analogue scale (VAS) for low back pain (LBP), VAS for leg pain (LP) and the Oswestry disability index (ODI).
Among 1,503 cases of all male soldiers, the MRIs showed that pseudocysts formed in 15 patients, about 1.0% of the initial cases. The mean postoperative interval from surgery to PP detection was 53.7 days. Interlaminar approach was correlated with PP formation compared with transforaminal approach (p=0.001). The mean VAS for LBP and LP in the surgical group improved from 6.5 and 4.8 to 2.0 and 2.3, respectively. The mean VAS for LBP and LP in the conservative group improved from 4.4 and 4.4 to 3.9 and 2.3, respectively. There was no difference in treatment outcome between surgical and conservative management of symptomatic PP.
Although this study was done in limited environment, symptomatic PP was detected at two months' postoperative period in about 1% of cases. Interlaminar approach seems to be more related with PP compared with transforaminal approach.
Endoscopic discectomy; Herniated disc; Lumbar; Postoperative complication; Pseudocyst
We experienced a rare case of solitary syphilitic osteomyelitis of the skull without any other clinical signs or symptoms of syphilis. A 20-year-old man was referred due to intermittent headache and mild tenderness at the right parietal area of the skull with a palpable coin-sized lesion of softened cortical bone. On radiological studies, the lesion was a radiolucent well enhanced mass (17 mm in diameter). The erythrocyte sedimentation rate (52 mm/h) and C-reactive protein (2.24 mg/dL) were elevated on admission. Serum venereal disease research laboratory (VDRL) and Treponema pallidum haemagglutination assay (TPHA) tests were positive. There were no clinical signs or symptoms of syphilis. After treatment with benzathine penicillin, we removed the lesion and performed cranioplasty. The pathologic finding of the skull lesion was fibrous proliferation with lymphoplasmocytic infiltration forming an osteolytic lesion. In addition, a spirochete was identified using the Warthin-starry stain. The polymerase chain reaction study showed a positive band for Treponema pallidum. Solitary osteomyelitis of the skull can be the initial presenting pathological lesion of syphilis.
Infectious osteomyelitis; Syphilis; Skull; Treponema pallidum
Remote cerebellar hemorrhage (RCH) is rare but potentially lethal as a complication of spinal surgery. We recently experienced a case of RCH in a 61-year-old man who showed mental deterioration after lumbar spinal surgery. There was dural tearing with subsequent cerebrospinal fluid (CSF) loss during the surgery. Brain computed tomography scan revealed cerebellar hemorrhage, 3rd and 4th ventricular hemorrhage and pneumocephalus. He underwent suboccipital craniectomy and hematoma removal. The most important pathomechanism leading to RCH after spinal surgery has been known to be venous bleeding due to caudal sagging of cerebellum by rapid leak of large amount of CSF which seems to be related with this case. Dural repair and minimizing CSF loss after intraoperative dural tearing would be helpful to prevent postoperative RCH.
Remote cerebellar hemorrhage; Spinal surgery; Dural tear; Cerebrospinal fluid leakage
Susceptibility-weighted image (SWI) is a sensitive magnetic resonance image (MRI) technique to detect cerebral microbleeds (MBLs), which would not be detected by conventional MRI. We performed SWI to detect MBLs and investigated its usefulness in the evaluation of mild traumatic brain injury (MTBI) patients.
From December 2006 to June 2007, twenty-one MTBI patients without any parenchymal hemorrhage on conventional MRI were selected. Forty-two patients without trauma were selected for control group. According to the presence of MBLs, we divided the MTBI group into MBLs positive [SWI (+)] and negative [SWI (-)] group. Regional distribution of MBLs and clinical factors were compared between groups.
Fifty-one MBLs appeared in 16 patients of SWI (+) group and 16 MBLs in 10 patients of control group [control (+)], respectively. In SWI (+) group, MBLs were located more frequently in white matters than in deep nucleus different from the control (+) group (p < 0.05). Nine patients (56.3%) of SWI (+) group had various neurological deficits (disorientation in 4, visual field defect in 2, hearing difficulty in 2 and Parkinson syndrome in 1). Initial Glasgow Coma Scale (GCS)/mean Glasgow Outcome Scale (GOS) were 13.9 ± 1.5 / 4.7 ± 0.8 and 15.0 ± 0.0 / 5.0 ± 0.0 in SWI (+) and SWI (-) groups, respectively (p < 0.05).
Traumatic cerebral MBLs showed characteristic regional distribution, and seemed to have an importance on the initial neurological status and the prognosis. SWI is useful for detection of traumatic cerebral MBLs, and can provide etiologic evidences for some post-traumatic neurologic deficits which were unexplainable with conventional MRI.
Traumatic brain injury; Susceptibility-weighted image; Microbleeds
Vascular injury during lumbar disc surgery is a rare but potentially life-threatening complication. It has been managed by open vascular surgical repair. With recent technologic advance, endovascular treatment became one of effective treatment modalities. We present a case of a 32-year-old woman who suffered with common iliac artery injury during lumbar disc surgery that was treated successfully by endovascular repair with temporary balloon occlusion and subsequent insertion of a covered stent. Temporary balloon occlusion for 1.5 hours could stop bleeding, but growing pseudoaneurysm was identified at the injury site during the following 13 days. It seems that the temporary balloon occlusion can stall bleeding from arterial injury for considerable time duration, but cannot be a single treatment modality and requires subsequent insertion of a covered stent.
Endovascular repair; Covered stent; Balloon occlusion; Lumbar disc surgery; Common iliac artery; Pseudoaneurysm
Barbiturate coma therapy (BCT) has been known to be an useful method to control increased intracranial pressure (IICP) refractory to medical and surgical treatments. We have used BCT for patients with severe IICP during the past 10 years, and analyzed our results with review of literatures.
We analyzed 92 semicomatose or comatose patients with Glasgow coma scale (GCS) of 7 or less with severe IICP due to cerebral edema secondary to parenchymal damages irrespective of their causes. Forty patients who had received BCT with ICP monitoring from January 1997 to December 2006 were included in BCT group, and fifty-two patients who had been managed without BCT from January 1991 to December 1995 were divided into control group. We compared outcomes with Glasgow outcome scale (GOS) and survival rate between the two groups.
Good outcome (GOS=4 and 5) rates at 3-month after insult were 27.5% and 5.8% in BCT and control group, respectively (p<0.01). One-year survival rates were 35.9% and 12.5% in BCT and control group, respectively (p<0.01). In BCT group, the mean age of good outcome patients (37.1 ± 14.9) was significantly lower than that of poor outcome patients (48.1 ± 13.5) (p<0.05).
With our 10-year experience, we suggest that BCT is an effective treatment method for severe IICP patients for better survival and GOS, especially for younger patients.
Barbiturate coma; Increased intracranial pressure; Survival; Glasgow outcome scale
Chronic neck or back pain can be managed with various procedures. Although these procedures are usually well-tolerated, a variety of side effects have been reported. In this study we reviewed cases of unexpected temporary adverse events after blocks and suggest possible causes.
We reviewed the records of patients treated with spinal pain blocks between December 2009 and January 2011. The types of blocks performed were medial branch blocks, interlaminar epidural blocks and transforaminal epidural blocks. During the first eight months of the study period (Group A), 2% mepivacaine HCL and triamcinolone was used, and during the last six months of the study period (Group B), mepivacaine was diluted to 1% with normal saline.
There were 704 procedures in 613 patients. Ten patients had 12 transient neurologic events. Nine patients were in Group A and one was in Group B. Transient complications occurred in four patients after cervical block and in eight patients after lumbar block. Side effects of lumbar spine blocks were associated with the concentration of mepivacaine (p<0.05). The likely causes were a high concentration of mepivacaine in five patients, inadvertent vascular injection in three patients, intrathecal leak of local anesthetics in one, and underlying conversion disorder in one.
Spinal pain blocks are a good option for relieving pain, but clinicians should always keep in mind the potential for development of inevitable complications. Careful history-taking, appropriate selection of the anesthetics, and using real-time fluoroscopy could help reduce the occurrence of adverse events.
Adverse effect; Spinal pain; Conversion disorder; Medial branch blocks; Paralysis; C2 ganglion block
The blood blister-like aneurysm (BBA) of the internal carotid artery (ICA) is a rare but clinically important cause of subarachnoid hemorrhage (SAH), which accounts for 0.5% of incidences of ruptured intracranial aneurysms. BBA is a thin-walled, broad-based aneurysm that lacks an identifiable neck and is one of the most difficult lesions to treat. In this paper, a case is presented of a 57-year-old woman with SAH. Her cerebral angiography demonstrated a small BBA on the dorsal wall of her right ICA. Endovascular treatment that consisted of a stent-within-a-stent was attempted, but the replacement of the second stent failed, and the aneurysm became bigger. Surgery was performed by clipping the BBA with a Sundt slim-line encircling graft clip. The patient completely recovered with no complications. This treatment may be a salvageable option for BBA, especially when endovascular treatment has failed.
Blood-blister like aneurysm; Internal carotid artery; Subarachnoid hemorrhage; Encircling graft clip; Endovascular stent
Many studies have reported spontaneous spinal epidural hematoma (SSEH). Although most cases are idiopathic, several are associated with thrombolytic therapy or anticoagulants. We report a case of SSEH coincident with acute myocardial infarction (AMI), which caused serious neurological deficits. A 56 year old man presented with chest pain accompanied with back and neck pain, which was regarded as an atypical symptom of AMI. He was treated with nitroglycerin, aspirin, low molecular weight heparin, and clopidogrel. A spinal magnetic resonance image taken after paraplegia developed 3 days after the initial symptoms revealed an epidural hematoma at the cervical and thoracolumbar spine. Despite emergent decompressive surgery, paraplegia has not improved 7 months after surgery. A SSEH should be considered when patients complain of abrupt, strong, and non-traumatic back and neck pain, particularly if they have no spinal pain history.
Acute myocardial infarction; Hematoma, epidural, spinal; Paraplegia; Thrombolytic therapy; Anticoagulants
Spontaneous acute subdural hematomas (aSDH) secondary to ruptured intracranial aneurysms are rarely reported. This report reviews the clinical features, diagnostic modalities, treatments, and outcomes of this unusual and often fatal condition.
We performed a database search for all cases of intracranial aneurysms treated at our hospital between 2005 and 2010. Patients with ruptured intracranial aneurysms who presented with aSDH on initial computed tomography (CT) were selected for inclusion. The clinical conditions, radiologic findings, treatments, and outcomes were assessed.
A total of 551 patients were treated for ruptured intracranial aneurysms during the review period. We selected 23 patients (4.2%) who presented with spontaneous aSDH on initial CT. Ruptured aneurysms were detected on initial 3D-CT angiography in all cases. All ruptured aneurysms were located in the anterior portion of the circle of Willis. The World Federation of Neurosurgical Societies grade on admission was V in 17 cases (73.9%). Immediate decompressive craniotomy was performed 22 cases (95.7%). Obliteration of the ruptured aneurysm was achieved in all cases. The Glasgow outcome scales for the cases were good recovery in 5 cases (21.7%), moderate disability to vegetative in 7 cases (30.4%), and death in 11 cases (47.8%).
Spontaneous aSDH caused by a ruptured intracranial aneurysm is rare pattern of aneurysmal subarachnoid hemorrhage. For early detection of aneurysm, 3D-CT angiography is useful. Early decompression with obliteration of the aneurysm is recommended. Outcomes were correlated with the clinical grade and CT findings on admission.
Acute subdural hematoma; Subarachnoid hemorrhage; Intracranial aneurysm; CT angiography
Norovirus is one of the most common causes of nonbacterial gastroenteritis in humans. Rapid spread by contaminated food and person-to-person transmission through the fecal-oral route are characteristics of norovirus epidemiology and result in high morbidity in vulnerable patient populations. Therefore, detection of norovirus is a major public health concern. Currently, the most common method for detecting and differentiating among norovirus strains in clinical and environmental samples is reverse transcription PCR (RT-PCR). Standardized positive controls used in RT-PCR assays to detect norovirus are designed to overcome the problem of false-negative results due to PCR inhibitors and suboptimal reaction conditions.
In the current study, four types of RNA transcripts were produced from plasmids: norovirus GI-5 and GII-4 capsid regions with human rotavirus (VP7 gene derived) fragment insertions, and norovirus GI-6 and GII-4 capsid regions with hepatitis A virus (VP1/P2A gene derived) fragment insertions. These size-distinguishable products were used as positive controls under the RT-PCR assay conditions used to detect NoV in stool and groundwater samples. Their reliability and reproducibility was confirmed by multiple sets of experiments.
These standardized products may contribute to the reliable and accurate diagnosis by RT-PCR of norovirus outbreaks, when conducted by laboratories located in different regions.
Glossopharyngeal neuralgia is a relatively rare condition characterized by severe, paroxysmal episodes of lancinating pain in the tongue, throat, ear, and tonsil. This disorder is assumed to be due to compression of the glossopharyngeal nerve by vascular structures. A 47-year-old woman complaining of sharp and lancinating pain in the right periauricular and submandibular areas visited our hospital. Swallowing, chewing, and lying on her right side triggered the pain. Her neurologic examination revealed no specific abnormalities. The results of routine hematologic and blood chemistry studies were all within normal limits. Carbamazepine and gabapentin were given, but her symptoms persisted. Her pain was temporarily relieved only by narcotic pain medication. MRI showed an arachnoid cyst located in the right cerebellomedullary cistern extending to the cerebellopontine cistern. Cyst removal was performed via a right retrosigmoid approach. Lateral suboccipital craniotomy was performed using the right park-bench position. After opening the dura and cerebellopontine angle, the arachnoid cyst was exposed. The arachnoid cyst was compressing the flattened lower cranial nerves at the right jugular fossa. Her symptoms resolved postoperatively. Two months after the operation, she was completely free from her previous symptoms.
Arachnoid cyst; Cerebellopontine angle; Glossopharyngeal neuralgia
We report a case of pedicle screw loosening treated by modified transpedicular screw augmentation technique using polymethylmethacrylate (PMMA), which used the anchoring effect of hardened PMMA. A 56-year-old man who had an L3/4/5 fusion operation 3 years ago complained of continuous low back pain after this operation. The computerized tomography showed a radiolucent halo around the pedicle screw at L5. We augmented the L5 pedicle screw with modified pedicle screw augmentation technique using PMMA and performed an L3/4/5 pedicle screw fixation without hook or operation field extension. This modified technique is a kind of transpedicular stiffness augmentation using PMMA for the dead space around the loosed screw. After filling the dead space with 1-2 cc of PMMA, we inserted a small screw. Once the PMMA hardened, we removed the small screw and inserted a thicker screw along the existing screw threading to improve the pedicle screws' pullout strength. At 10 months' follow-up, x-ray showed strong fusion of L3/4/5. The visual analogue scale (VAS) of his back pain was improved from 9 to 5. This modified transpedicular screw augmentation with PMMA using anchoring effect is a simple and effective surgical technique for pedicle screw loosening. However, clinical analyses of long-term follow-up and biomechanical studies are needed.
Instrument failure; Osteoporosis; Pedicle screw loosening; PMMA; Pseudoarthrosis; Surgical technique
Capillary hemangiomas are common soft tissue tumors on the skin or mucosa of the head and neck in the early childhood, but very rare in the neuraxis. A 47-year-old man presented with one month history of back pain on the lower thoracic area, radiating pain to both legs, and hypesthesia below T7 dermatome. Thoracic spine MRI showed 1×1.3×1.5 cm, well-defined intradural mass at T6-7 disc space level, which showed isointensity to spinal cord on T1, heterogeneous isointensity on T2-weighted images, and homogeneous strong enhancement. The patient underwent T6-7 total laminotomy, complete tumor removal and laminoplasty. Histologically, the mass showed a capsulated nodular lesion composed of capillary-sized vascular channels, which were tightly packed into nodules separated by fibrous septa. These features were consistent with capillary hemangioma.
Capillary hemangioma; Spinal cord; Intradural extramedullary tumor
Peroxisome proliferator-activated receptor (PPAR)-γ is a ligand-activated transcription factor of nuclear hormone receptor superfamily. Thiazolidinedione rosiglitazone is a potent agonist of PPARγ which was shown to induce neuroprotection in animal models of focal ischemia and spinal cord injury. We currently evaluated the therapeutic potential of rosiglitazone (6 mg/kg at 5 min, 6 h and 24 h; i.p.) following controlled cortical impact (CCI)-induced traumatic brain injury (TBI) in adult mice. CCI injury increased the cortical PPARγ mRNA levels which were further elevated by rosiglitazone treatment. In addition, rosiglitazone treatment significantly decreased the cortical lesion volume measured at 7 days compared to vehicle treatment (by 56 ± 7%; p < 0.05; n = 6/group). Following TBI, the spared cortex of the rosiglitazone group showed significantly less numbers of GSI-B4+ activated microglia/macrophages and ICAM1+ capillaries, and curtailed induction of pro-inflammatory genes IL6, MCP1 and ICAM1 compared to vehicle group. Rosiglitazone-treated mice also showed significantly less number of TUNEL+ apoptotic neurons and curtailed induction of caspase-3 and Bax, compared to vehicle control. In addition, rosiglitazone significantly enhanced the post-TBI expression of the neuroprotective chaperones HSP27, HSP70 and HSP32/HO1, and the anti-oxidant enzymes catalase, Cu/Zn-SOD and Mn-SOD, compared to vehicle. Treatment with GW9662 (a specific PPARγ antagonist) prevented all the above PPARγ-mediated actions. Thus, PPARγ activation confers neuroprotection after TBI by anti-inflammatory, anti-apoptotic and anti-oxidative mechanisms.
Rosiglitazone; Brain trauma; Inflammation; Oxidative stress; Neuroprotection
We report the case of a 64-year-old man with dural arteriovenous fistula (DAVF) at right jugular foramen, presented as subarachnoid and intraventricular hemorrhage. The malformation was fed by only the neuromeningeal trunk of the right ascending pharyngeal artery and drained into the right lateral medullary veins craniopetally. Complete embolization was attained by selective transarterial glue injection, but patient showed lower cranial neuropathies. A 3-month follow-up angiogram still showed persistent fistula occlusion. Transarterial glue embolization is a feasible method, only if a transvenous access is not possible in case of single channel fistula.
Dural arteriovenous fistula; Glue; Intra arterial injection; Subarachnoid hemorrhage
Inflammatory pseudotumor is an uncommon lesion with unknown etiology characterized by sclerosing inflammation which clinically and radiographically mimics a neoplastic lesion. A 47-year-old man presented with sudden headache and dysarthria. Brain CT scan revealed a 2.6×2.2 cm sized, round, and hyperdense mass in the anterolateral wall of the left lateral ventricular trigone. On MR imaging studies, the mass showed low signal intensity in the wall of the trigone on T2-weighted image, central mixed (iso- and high-) signal intensity with peripheral low-signal intensity on T1-weighted image. Subtle staining of left choroid plexus with irregular shaped distal branch of anterior choroidal artery was found on the cerebral angiography. These findings suggested a small tumorous lesion originated from the left choroid plexus. During the hospital days, the mass manifested as repeated hemorrhages. The mass was successfully removed via left occipital transcortical approach. The histopathological report of the specimen was hemorrhage and fibrosis, with dense lymphoplasma cell infiltration, suggestive of an inflammatory pseudotumor.
Intraventricular tumor; Inflammatory pseudotumor; Hemorrhage
Despite differences in size and sequence, the two noncoding roX1 and roX2 RNAs are functionally redundant for dosage compensation of the Drosophila melanogaster male X chromosome. Consistent with functional conservation, we found that roX RNAs of distant Drosophila species could complement D. melanogaster roX mutants despite low homology. Deletion of a conserved predicted stem-loop structure in roX2, containing a short GUb (GUUNUACG box) in its 3′ stem, resulted in a defect in histone H4K16 acetylation on the X chromosome in spite of apparently normal localization of the MSL complex. Two copies of the GUb sequence, newly termed the “roX box,” were functionally redundant in roX2, as mutants in a single roX box had no phenotype, but double mutants showed reduced H4K16 acetylation. Interestingly, mutation of two of three roX boxes in the 3′ end of roX1 RNA also reduced H4K16 acetylation. Finally, fusion of roX1 sequences containing a roX box restored function to a roX2 deletion RNA lacking its cognate roX box. These results support a model in which the functional redundancy between roX1 and roX2 RNAs is based, at least in part, on short GUUNUACG sequences that regulate the activity of the MSL complex.
Sequencing of multiple related species followed by comparative genomics analysis constitutes a powerful approach for the systematic understanding of any genome. Here, we use the genomes of 12 Drosophila species for the de novo discovery of functional elements in the fly. Each type of functional element shows characteristic patterns of change, or ‘evolutionary signatures’, dictated by its precise selective constraints. Such signatures enable recognition of new protein-coding genes and exons, spurious and incorrect gene annotations, and numerous unusual gene structures, including abundant stop-codon readthrough. Similarly, we predict non-protein-coding RNA genes and structures, and new microRNA (miRNA) genes. We provide evidence of miRNA processing and functionality from both hairpin arms and both DNA strands. We identify several classes of pre- and post-transcriptional regulatory motifs, and predict individual motif instances with high confidence. We also study how discovery power scales with the divergence and number of species compared, and we provide general guidelines for comparative studies.
Topoisomerase IIα interacts with numerous nuclear factors, through which it is engaged in diverse nuclear events such as DNA replication, transcription and the formation or maintenance of heterochromatin. We previously reported that topoisomerase IIα interacts with RNA helicase A (RHA), consistent with a recent view that topoisomerases and helicases function together. Intrigued by our observation that the RHA–topoisomerase IIα interaction is sensitive to ribonuclease A, we explored whether the RHA–topoisomerase IIα interaction can be recapitulated in vitro using purified proteins and a synthetic RNA. This work led us to an unexpected finding that an RNA-binding activity is intrinsically associated with topoisomerase IIα. Topoisomerase IIα stably interacted with RNA harboring a 3′-hydroxyl group but not with RNA possessing a 3′-phosphate group. When measured in decatenation and relaxation assays, RNA binding influenced the catalytic function of topoisomerase IIα to regulate DNA topology. We discuss a possible interaction of topoisomerase IIα with the poly(A) tail and G/U-rich 3′-untranslated region (3′-UTR) of mRNA as a key step in transcription termination.
Inflammation is a known precipitator of neuronal death after cerebral ischemia. The mechanisms that promote or curtail the start and spread of inflammation in brain are still being debated. By virtue of their capability to modulate gene expression, several transcription factors induced in the ischemic brain can modulate the post-ischemic inflammation. While the induction of transcription factors such as IRF1, NF-κB, ATF-2, STAT3, Egr1 and C/EBPβ is thought to promote post-ischemic inflammation, activation of transcription factors such as HIF-1, CREB, c-fos, PPARα, PPARγ and p53 is thought to prevent post-ischemic inflammation and neuronal damage. Of these, PPARγ which is a ligand-activated transcription factor was recently shown to prevent inflammatory gene expression in several animal models CNS disorders. This review article discusses some of the molecular mechanisms of PPARγ induction by its agonists following focal cerebral ischemia.
transcription factors; PPAR gamma; cerebral ischemia; inflammation
In this study, we compared the paramedian interfascial approach (PIA) and the traditional midline approach (MA) for lumbar fusion to determine which approach resulted in the least amount of postoperative back muscle atrophy. We performed unilateral transforaminal posterior lumbar interbody fusion via MA on the symptomatic side and pedicle screw fixation via PIA on the other side in the same patient. We evaluated the damage to the paraspinal muscle after MA and PIA by measuring the preoperative and postoperative paraspinal muscle volume in 26 patients. The preoperative and postoperative cross-sectional area, thickness, and width of the multifidus muscle were measured by computed tomography. The degree of postoperative paraspinal muscle atrophy was significantly greater on the MA side than on the contralateral PIA side (-20.7% and -4.8%, respectively, p<0.01). In conclusion, the PIA for lumbar fusion yielded successful outcomes for the preservation of paraspinal muscle in these 26 patients. We suggest that the success of PIA is due to less manipulation and retraction of the paraspinal muscle and further studies on this technique may help confirm whether less muscle injury has positive effects on the long-term clinical outcome.
Paraspinal Muscle; Paramedian Approach; Muscle Atrophy; Lumbar Spine