The Anti-Inflammatory Compound Curcumin Enhances Locomotor and Sensory Recovery after Spinal Cord Injury in Rats by Immunomodulation.

Well known for its anti-oxidative and anti-inflammation properties, curcumin is a polyphenol found in the rhizome of Curcuma longa. In this study, we evaluated the effects of curcumin on behavioral recovery, glial scar formation, tissue preservation, axonal sprouting, and inflammation after spinal cord injury (SCI) in male Wistar rats. The rats were randomized into two groups following a balloon compression injury at the level of T9-T10 of the spinal cord, namely vehicle- or curcumin-treated. Curcumin was applied locally on the surface of the injured spinal cord immediately following injury and then given intraperitoneally daily; the control rats were treated with vehicle in the same manner. Curcumin treatment improved behavioral recovery within the first week following SCI as evidenced by improved Basso, Beattie, and Bresnahan (BBB) test and plantar scores, representing locomotor and sensory performance, respectively. Furthermore, curcumin treatment decreased glial scar formation by decreasing the levels of MIP1α, IL-2, and RANTES production and by decreasing NF-κB activity. These results, therefore, demonstrate that curcumin has a profound anti-inflammatory therapeutic potential in the treatment of spinal cord injury, especially when given immediately after the injury.

The impact of arsenic trioxide and all-trans retinoic acid on p53 R273H-codon mutant glioblastoma.

Glioblastoma (GBM) is the most common primary brain tumor in adults and demonstrates a 1-year median survival time. Codon-specific hotspot mutations of p53 result in constitutively active mutant p53, which promotes aberrant proliferation, anti-apoptosis, and cell cycle checkpoint failure in GBM. Recently identified CD133(+) cancer stem cell populations (CSC) within GBM also confer therapeutic resistance. We studied targeted therapy in a codon-specific p53 mutant (R273H) created by site-directed mutagenesis in U87MG. The effects of arsenic trioxide (ATO, 1 µM) and all-trans retinoic acid (ATRA, 10 µM), possible targeted treatments of CSCs, were investigated in U87MG neurospheres. The results showed that U87-p53(R273H) cells generated more rapid neurosphere growth than U87-p53(wt) but inhibition of neurosphere proliferation was seen with both ATO and ATRA. U87-p53(R273H) neurospheres showed resistance to differentiation into glial cells and neuronal cells with ATO and ATRA exposure. ATO was able to generate apoptosis at high doses and proliferation of U87-p53(wt) and U87-p53(R273H) cells was reduced with ATO and ATRA in a dose-dependent manner. Elevated pERK1/2 and p53 expression was seen in U87-p53(R273H) neurospheres, which could be reduced with ATO and ATRA treatment. Additionally, differential responses in pERK1/2 were seen with ATO treatment in neurospheres and non-neurosphere cells. In conclusion, codon-specific mutant p53 conferred a more aggressive phenotype to our CSC model. However, ATO and ATRA could potently suppress CSC properties in vitro and may support further clinical investigation of these agents.

Human mesenchymal stem cells modulate inflammatory cytokines after spinal cord injury in rat.

Transplantation of mesenchymal stem cells (MSC) improves functional recovery in experimental models of spinal cord injury (SCI); however, the mechanisms underlying this effect are not completely understood. We investigated the effect of intrathecal implantation of human MSC on functional recovery, astrogliosis and levels of inflammatory cytokines in rats using balloon-induced spinal cord compression lesions. Transplanted cells did not survive at the lesion site of the spinal cord; however, functional recovery was enhanced in the MSC-treated group as was confirmed by the Basso, Beattie, and Bresnahan (BBB) and the flat beam test. Morphometric analysis showed a significantly higher amount of remaining white matter in the cranial part of the lesioned spinal cords. Immunohistochemical analysis of the lesions indicated the rearrangement of the glial scar in MSC-treated animals. Real-time PCR analysis revealed an increased expression of Irf5, Mrc1, Fgf2, Gap43 and Gfap. Transplantation of MSCs into a lesioned spinal cord reduced TNFα, IL-4, IL-1ß, IL-2, IL-6 and IL-12 and increased the levels of MIP-1α and RANTES when compared to saline-treated controls. Intrathecal implantation of MSCs reduces the inflammatory reaction and apoptosis, improves functional recovery and modulates glial scar formation after SCI, regardless of cell survival. Therefore, repeated applications may prolong the beneficial effects induced by MSC application.

Long-term outcomes of the Universal 2 total wrist replacement: revision and loosening at 10 years and beyond.

The aim of this study was to ascertain the long-term revision rates of the Universal 2 wrist prosthesis in a previously published cohort of patients with rheumatoid arthritis. The time to, and reasons for revision were determined. Radiographs were analysed to determine whether loosening had occurred in the long-term according to the Wrightington zonal classification of loosening. Seventy-eight wrists from the original cohort of 85 wrists could be identified for analysis. The longest follow-up was 16 years and 29 wrists had follow-up beyond 10 years. Seventeen wrists had been revised or were on the waiting list for revision, an overall revision rate of 22%. The 10-year survivorship was 78%. Long-term revision was commonly for periprosthetic loosening with pain and component subsidence. In those with more than 10-year follow-up, significant lucency was seen in 16 carpal components and 15 radial components. Explant analysis showed significant polyethylene wear and we postulate this is the principal reason for component loosening.Level of evidence: IV.

Targeting the mTOR pathway using novel ATP­competitive inhibitors, Torin1, Torin2 and XL388, in the treatment of glioblastoma.

Mechanistic target of rapamycin (mTOR), which functions via two multiprotein complexes termed mTORC1 and mTORC2, is positioned in the canonical phosphoinositide 3­kinase­related kinase (PI3K)/AKT (PI3K/AKT) pathways. These complexes exert their actions by regulating other important kinases, such as 40S ribosomal S6 kinases (S6K), eukaryotic translation initiation factor 4E (elF4E)­binding protein 1 (4E­BP1) and AKT, to control cell growth, proliferation, migration and survival in response to nutrients and growth factors. Glioblastoma (GB) is a devastating form of brain cancer, where the mTOR pathway is deregulated due to frequent upregulation of the Receptor Tyrosine Kinase/PI3K pathways and loss of the tumor suppressor phosphatase and tensin homologue (PTEN). Rapamycin and its analogs were less successful in clinical trials for patients with GB due to their incomplete inhibition of mTORC1 and the activation of mitogenic pathways via negative feedback loops. Here, the effects of selective ATP­competitive dual inhibitors of mTORC1 and mTORC2, Torin1, Torin2 and XL388, are reported. Torin2 exhibited concentration­dependent pharmacodynamic effects on inhibition of phosphorylation of the mTORC1 substrates S6KSer235/236 and 4E­BP1Thr37/46 as well as the mTORC2 substrate AKTSer473 resulting in suppression of tumor cell migration, proliferation and S­phase entry. Torin1 demonstrated similar effects, but only at higher doses. XL388 suppressed cell proliferation at a higher dose, but failed to inhibit cell migration. Treatment with Torin1 suppressed phosphorylation of proline rich AKT substrate of 40 kDa (PRAS40) at Threonine 246 (PRAS40Thr246) whereas Torin2 completely abolished it. XL388 treatment suppressed the phosphorylation of PRAS40Thr246 only at higher doses. Drug resistance analysis revealed that treatment of GB cells with XL388 rendered partial drug resistance, which was also seen to a lesser extent with rapamycin and Torin1 treatments. However, treatment with Torin2 completely eradicated the tumor cell population. These results strongly suggest that Torin2, compared to Torin1 or XL388, is more effective in suppressing mTORC1 and mTORC2, and therefore in the inhibition of the GB cell proliferation, dissemination and in overcoming resistance to therapy. These findings underscore the significance of Torin2 in the treatment of GB.

Prevention of cerebral vasospasm by local delivery of cromakalim with a biodegradable controlled-release system in a rat model of subarachnoid hemorrhage.

OBJECT: One mechanism that contributes to cerebral vasospasm is the impairment of potassium channels in vascular smooth muscles. Adenosine triphosphate-sensitive potassium channel openers (PCOs) appear to be particularly effective for dilating cerebral arteries in experimental models of subarachnoid hemorrhage (SAH). A mode of safe administration that provides timed release of PCO drugs is still a subject of investigation. The authors tested the efficacy of locally delivered intrathecal cromakalim, a PCO, incorporated into a controlled-release system to prevent cerebral vasospasm in a rat model of SAH. METHODS: Cromakalim was coupled to a viscous carrier, hyaluronan, 15% by weight. In vitro release kinetics studies showed a steady release of cromakalim over days. Fifty adult male Sprague-Dawley rats weighing 350-400 g each were divided into 10 groups and treated with various doses of cromakalim or cromakalim/hyaluronan in a rat double SAH model. Treatment was started 30 minutes after the second SAH induction. Animals were killed 3 days after treatment, and the basilar arteries were processed for morphometric measurements and histological analysis. RESULTS: Controlled release of cromakalim from the cromakalim/hyaluronan implant at a dose of 0.055 mg/kg significantly increased lumen patency in a dose-dependent manner up to 94 +/- 8% (mean +/- standard error of the mean) of the basilar arteries of the sham group compared with the empty polymer group (p = 0.006). Results in the empty polymer group were not different from those in the SAH-only group, with a lumen patency of 65 +/- 12%. Lumen patencies of the cromakalim-only groups did not differ in statistical significance at low (64 +/- 9%) or high (66 +/- 7%) doses compared to the SAH-only group. CONCLUSIONS: Treatment of SAH with a controlled-release cromakalim/hyaluronan implant prevented experimental cerebral vasospasm in this rat double hemorrhage model; this inhibition was dose-dependent. The authors' results confirm that sustained delivery of cromakalim perivascularly to cerebral vessels could be an effective therapeutic strategy in the treatment of cerebral vasospasm after SAH.

Rho/ROCK and MAPK signaling pathways are involved in glioblastoma cell migration and proliferation.

BACKGROUND: Glioblastoma multiforme (GBM) remains the most aggressive and frequently occurring brain neoplasm. Members of the Rho family of small GTP-binding proteins, including Rho, Rac, and Cdc42, have been shown to participate in cell growth differentiation and motility. The mitogen-activated protein kinase (MAPK) pathway, which includes extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), has been shown to regulate cell growth, differentiation and motility. Here, the involvement of the Rho and Rho-associated protein kinase (ROCK) pathway, along with MAPK, was investigated to determine their roles in GBM cell migration and proliferation. MATERIALS AND METHODS: In vitro studies utilized the human malignant glioblastoma cell line LN-18. The cells were treated with Y-27632, a ROCK inhibitor, and U0126, an upstream MAPK kinase inhibitor (MEK), alone or in combination with one another. Immunoblotting analysis established the levels of phosphorylated ERK1/2. Cell migration was determined by radial migration assay and cell proliferation by MTT. RESULTS: Y-27632 reduced phosphorylation of ERK1/2 at 0.5 and 2 h. U0126 in combination with Y-27632 led to a more pronounced repression of platelet-derived growth factor (PDGF)- or fibronectin (FN)-induced ERK1/2 activation than U0126 treatment alone. Y-27632 treatment for 24 h suppressed GBM cell migration and resulted in a reduction in LN-18 cell proliferation. Furthermore, PDGF and FN-induced cell proliferation was suppressed by pre-treatment with Y-27632 or U0126, with the greatest reduction achieved by a combination of the two inhibitors. CONCLUSION: Rho/ROCK signaling is involved in GBM cell migration and proliferation, and this pathway may be linked to ERK signaling.

Diverse signaling mechanisms of mTOR complexes: mTORC1 and mTORC2 in forming a formidable relationship.

Activation of Mechanistic target of rapamycin (mTOR) signaling plays a crucial role in tumorigenesis of numerous malignancies including glioblastoma (GB). The Canonical PI3K/Akt/mTOR signaling cascade is commonly upregulated due to loss of the tumor suppressorm PTEN, a phosphatase that acts antagonistically to the kinase (PI3K) in conversion of PIP2 to PIP3. mTOR forms two multiprotein complexes, mTORC1 and mTORC2 which are composed of discrete protein binding partners to regulate cell growth, motility, and metabolism. These complexes are sensitive to distinct stimuli, as mTORC1 is sensitive to nutrients while mTORC2 is regulated via PI3K and growth factor signaling. The main function of mTORC1 is to regulate protein synthesis and cell growth through downstream molecules: 4E-BP1 (also called EIF4E-BP1) and S6K. On the other hand, mTORC2 is responsive to growth factor signaling by phosphorylating the C-terminal hydrophobic motif of some AGC kinases like Akt and SGK and it also plays a crucial role in maintenance of normal and cancer cells through its association with ribosomes, and is involved in cellular metabolic regulation. mTORC1 and mTORC2 regulate each other, as shown by the fact that Akt regulates PRAS40 phosphorylation, which disinhibits mTORC1 activity, while S6K regulates Sin1 to modulate mTORC2 activity. Allosteric inhibitors of mTOR, rapamycin and rapalogs, remained ineffective in clinical trials of Glioblastoma (GB) patients, in part due to their incomplete inhibition of mTORC1 as well as unexpected activation of mTOR via the loss of negative feedback loops. In recent years, novel ATP binding inhibitors of mTORC1 and mTORC2 suppress mTORC1 activity completely by total dephosphorylation of its downstream substrate pS6KSer235/236, while effectively suppressing mTORC2 activity, as demonstrated by complete dephosphorylation of pAKTSer473. Furthermore by these novel combined mTORC1/mTORC2 inhibitors reduced the proliferation and self-renewal of GB cancer stem cells. However, a search of more effective way to target mTOR has generated a third generation inhibitor of mTOR, "Rapalink", that bivalently combines rapamycin with an ATP-binding inhibitor, which effectively abolishes the mTORC1 activity. All in all, the effectiveness of inhibitors of mTOR complexes can be judged by their ability to suppress both mTORC1/mTORC2 and their ability to impede both cell proliferation and migration along with aberrant metabolic pathways.

High-dose intraarterial verapamil in the treatment of cerebral vasospasm after aneurysmal subarachnoid hemorrhage.

OBJECT: Because oral calcium channel blockers appear to reduce the severity of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH), interest in their application intraarterially has emerged for cases in which noninvasive means of alleviating vasospasm are unsuccessful. Studies to date have been limited to the administration of low intraarterial doses because of concerns about hemodynamic stability and changes in intracranial pressure. These doses, although effective in cases of milder vasospasm, were inadequate in severe cases. The authors present a series of 10 patients with cerebral vasospasm who underwent 12 procedures in which they received > or = 20 mg of intraarterial verapamil per procedure. METHODS: A retrospective review was undertaken of all patients who underwent endovascular treatment for cerebral vasospasm due to aneurysmal SAH by the senior author between February 2005 and October 2006. Ten patients were identified who had undergone a total of 12 procedures during which > or =20 mg of intraarterial verapamil had been administered. From angiography reports, anesthesia records, and nursing records, we obtained pre- and postverapamil mean arterial blood pressures (MABPs), heart rates, intracranial pressures (ICPs) (when available), and visible changes in the degree of vasospasm. RESULTS: No statistically significant changes in MABP, heart rate, or ICP were observed after administration of > or = 20 mg of intraarterial verapamil, and the degree of improvement in vasospasm was statistically significant based on our grading system. No correlation was found between the change in hemodynamic parameters and the total dose of verapamil. CONCLUSIONS: This study indicates that high-dose intraarterial verapamil may be used to treat cerebral vasospasm without compromising hemodynamic stability or increasing ICP.

Percutaneous balloon compression for the treatment of recurrent trigeminal neuralgia: long-term outcome in 29 patients.

OBJECTIVE: To analyze the long-term clinical outcomes and complication rates associated with percutaneous balloon compression (PBC) of the trigeminal ganglion in patients with recurrent trigeminal neuralgia (TN) who were treated surgically with procedures other than PBC. METHODS: In this retrospective study, the authors reviewed the results of 29 patients who underwent 41 PBC procedures for recurrent TN between 1998 and 2006. RESULTS: The overall mean length of follow-up was 49 months (range 1-101). Pain relief was immediate in 24 (83%) patients. There was no pain relief in 5 patients (17%). 2 patients were lost to follow-up. 12 (54.5%) of 22 patients remained pain-free during a mean follow-up period of 65 months (range 40-101). The other 10 patients (45.5%) who had immediate pain relief experienced recurrent pain, with a mean time to recurrence of 7.3 months (17 days to 38 months). PBC was repeated in 11 patients, and was performed a third time in 2 patients. Morbidities included minor dysesthesia (2 patients), masseter weakness (2 patients), corneal anesthesia (1 patient), anesthesia dolorosa (1 patient), and subarachnoid hemorrhage (1 patient with history of multiple myeloma). CONCLUSION: PBC is a useful treatment for patients with recurrent TN who have already been treated surgically. Long-term relief of pain in this subset of TN patients is achieved nearly half of the time with side-effect profiles similar to those reported in published data.

Molecular Sequence of Events and Signaling Pathways in Cerebral Metastases.

Brain metastases are the leading cause of morbidity and mortality among cancer patients, and are reported to occur in about 40% of cancer patients with metastatic disease in the United States of America. Primary tumor cells appear to detach from the parent tumor site, migrate, survive and pass through the blood brain barrier in order to establish cerebral metastases. This complex process involves distinct molecular and genetic mechanisms that mediate metastasis from these primary organs to the brain. Furthermore, an interaction between the invading cells and cerebral milieu is shown to promote this process as well. Here, we review the mechanisms by which primary cancer cells metastasize to the brain via a mechanism called epithelial-to-mesenchymal transition, as well as the involvement of certain microRNA and genetic aberrations implicated in cerebral metastases from the lung, breast, skin, kidney and colon. While the mechanisms governing the development of brain metastases remain a major hindrance in treatment, understanding and identification of the aforementioned molecular pathways may allow for improved management and discovery of novel therapeutic targets.

Gene expression profiling of metastatic brain cancer.

Gene expression profiling of metastatic brain tumors from primary lung adenocarcinoma, using a 17k-expression array, revealed that 1561 genes were consistently altered. Further functional classification placed the genes into seven categories: cell cycle and DNA damage repair, apoptosis, signal transduction molecules, transcription factors, invasion and metastasis, adhesion, and angiogenesis. Genes involved in apoptosis, such as caspase 2 (CASP2), transforming growth factor-beta inducible early gene (TIEG), and neuroprotective heat shock protein 70 (Hsp70) were underexpressed in metastatic brain tumors. Alterations in Rho GTPases (ARHGAP26, ARHGAP1), as well as down-regulation of the metastasis suppressor gene KiSS-1 were noted, which may contribute to tumor aggression. Overexpression of the invasion-related gene neurofibromatosis 1 (NF1), and angiogenesis-related genes vascular endothelial growth factor-B (VEGF-B) and placental growth factor (PGF) was also evidenced. Brain-specific angiogenesis inhibitors 1 and 3 (BAI1 and BAI3) were underexpressed as well. Examination of cell-adhesion and migration-related genes revealed an increased expression of integrins and extracellular matrices collagen and laminin. The study also showed alterations in p53 protein-associated genes, among these increased gene expression of p53, up-regulation of Reprimo or candidate mediator of the p53-dependent G2-arrest, down-regulation of p53-regulated apoptosis-inducing protein 1 (p53AIP1), decreased expression of tumor protein inducible nuclear protein 1 (p53DINP1), and down-regulation of Mdm4 (MDMX). The results demonstrated that genes involved in adhesion, motility, and angiogenesis were consistently up-regulated in metastatic brain tumors, while genes involved in apoptosis, neuroprotection, and suppression of angiogenesis were markedly down-regulated, collectively making these cancer cells prone to metastasis.

Neurosurgical experience with malpractice litigation: an analysis of closed claims against neurosurgeons in New York State, 1999 through 2003.

OBJECT: Neurosurgeons are a high-risk group for allegations of malpractice. To determine the kinds of cases and the neurosurgical practice patterns associated with the highest proportion of litigation, the authors examined the experience over a 5-year period of a major physician-owned and -administered insurance company dealing with this issue, the Medical Liability Mutual Insurance Company (MLMIC) of New York. With the MLMIC cases as a basis, the authors also analyzed areas of physician vulnerability and determined the steps neurosurgeons can take to reduce potential litigation. METHODS: All cases closed against MLMIC-insured neurosurgeons from January 1, 1999, through December 30, 2003, were reviewed. Variables examined included allegation, anatomical site, and the ultimate resolution of the case. Of the 280 cases against neurosurgeons that were closed during the study period, 156 (56%) involved the spine, 109 (39%) involved the head and/or brain, and 15 (5%) reflected miscellaneous allegations. These proportions are relatively similar to the 1999 procedural statistics for neurosurgical practices. Of the cases examined, 98 were closed with a total loss indemnity of approximately $50 million, and 182 resulted in no indemnity payment. CONCLUSIONS: A neurosurgeon's chances of being sued for malpractice are not necessarily related to the medical complexity of a particular case but rather to the types of cases with which the physician is involved. Elective spinal surgery cases constitute the majority of litigation. Neurosurgeons can take steps to reduce their vulnerability to potential litigation and to increase the odds of a successful defense.

Inhibition of x-irradiation-enhanced locomotor recovery after spinal cord injury by hyperbaric oxygen or the antioxidant nitroxide tempol.

OBJECT: Hyperbaric oxygen (HBO), the nitroxide antioxidant tempol, and x-irradiation have been used to promote locomotor recovery in experimental models of spinal cord injury. The authors used x-irradiation of the injury site together with either HBO or tempol to determine whether combined therapy offers greater benefit to rats. METHODS: Contusion injury was produced with a weight-drop device in rats at the T-10 level, and recovery was determined using the 21-point Basso-Beattie-Bresnahan (BBB) locomotor scale. Locomotor function recovered progressively during the 6-week postinjury observation period and was significantly greater after x-irradiation (20 Gy) of the injury site or treatment with tempol (275 mg/kg intraperitoneally) than in untreated rats (final BBB Scores 10.6 [x-irradiation treated] and 9.1 [tempol treated] compared with 6.4 [untreated], p < 0.05). Recovery was not significantly improved by HBO (2 atm for 1 hour [BBB Score 8.2, p > 0.05]). Interestingly, the improved recovery of locomotor function after x-irradiation, in contrast with antiproliferative radiotherapy for neoplasia, was inhibited when used together with either HBO or tempol (BBB Scores 8.2 and 8.3, respectively). The ability of tempol to block enhanced locomotor recovery by x-irradiation was accompanied by prevention of alopecia at the irradiation site. The extent of locomotor recovery following treatment with tempol, HBO, and x-irradiation correlated with measurements of spared spinal cord tissue at the contusion epicenter. CONCLUSIONS: These results suggest that these treatments, when used alone, can activate neuroprotective mechanisms but, in combination, may result in neurotoxicity.

Discrete signaling mechanisms of mTORC1 and mTORC2: Connected yet apart in cellular and molecular aspects.

Activation of PI3K/Akt/mTOR (mechanistic target of rapamycin) signaling cascade has been shown in tumorigenesis of numerous malignancies including glioblastoma (GB). This signaling cascade is frequently upregulated due to loss of the tumor suppressor PTEN, a phosphatase that functions antagonistically to PI3K. mTOR regulates cell growth, motility, and metabolism by forming two multiprotein complexes, mTORC1 and mTORC2, which are composed of special binding partners. These complexes are sensitive to distinct stimuli. mTORC1 is sensitive to nutrients and mTORC2 is regulated via PI3K and growth factor signaling. mTORC1 regulates protein synthesis and cell growth through downstream molecules: 4E-BP1 (also called EIF4E-BP1) and S6K. Also, mTORC2 is responsive to growth factor signaling by phosphorylating the C-terminal hydrophobic motif of some AGC kinases like Akt and SGK. mTORC2 plays a crucial role in maintenance of normal and cancer cells through its association with ribosomes, and is involved in cellular metabolic regulation. Both complexes control each other as Akt regulates PRAS40 phosphorylation, which disinhibits mTORC1 activity, while S6K regulates Sin1 to modulate mTORC2 activity. Another significant component of mTORC2 is Sin1, which is crucial for mTORC2 complex formation and function. Allosteric inhibitors of mTOR, rapamycin and rapalogs, have essentially been ineffective in clinical trials of patients with GB due to their incomplete inhibition of mTORC1 or unexpected activation of mTOR via the loss of negative feedback loops. Novel ATP binding inhibitors of mTORC1 and mTORC2 suppress mTORC1 activity completely by total dephosphorylation of its downstream substrate pS6KSer235/236, while effectively suppressing mTORC2 activity, as demonstrated by complete dephosphorylation of pAKTSer473. Furthermore, proliferation and self-renewal of GB cancer stem cells are effectively targetable by these novel mTORC1 and mTORC2 inhibitors. Therefore, the effectiveness of inhibitors of mTOR complexes can be estimated by their ability to suppress both mTORC1 and 2 and their ability to impede both cell proliferation and migration.

A Comparative Study of Three Different Types of Stem Cells for Treatment of Rat Spinal Cord Injury.

Three different sources of human stem cells-bone marrow-derived mesenchymal stem cells (BM-MSCs), neural progenitors (NPs) derived from immortalized spinal fetal cell line (SPC-01), and induced pluripotent stem cells (iPSCs)-were compared in the treatment of a balloon-induced spinal cord compression lesion in rats. One week after lesioning, the rats received either BM-MSCs (intrathecally) or NPs (SPC-01 cells or iPSC-NPs, both intraspinally), or saline. The rats were assessed for their locomotor skills (BBB, flat beam test, and rotarod). Morphometric analyses of spared white and gray matter, axonal sprouting, and glial scar formation, as well as qPCR and Luminex assay, were conducted to detect endogenous gene expression, while inflammatory cytokine levels were performed to evaluate the host tissue response to stem cell therapy. The highest locomotor recovery was observed in iPSC-NP-grafted animals, which also displayed the highest amount of preserved white and gray matter. Grafted iPSC-NPs and SPC-01 cells significantly increased the number of growth-associated protein 43 (GAP43+) axons, reduced astrogliosis, downregulated Casp3 expression, and increased IL-6 and IL-12 levels. hMSCs transiently decreased levels of inflammatory IL-2 and TNF-α. These findings correlate with the short survival of hMSCs, while NPs survived for 2 months and matured slowly into glia- and tissue-specific neuronal precursors. SPC-01 cells differentiated more in astroglial phenotypes with a dense structure of the implant, whereas iPSC-NPs displayed a more neuronal phenotype with a loose structure of the graft. We concluded that the BBB scores of iPSC-NP- and hMSC-injected rats were superior to the SPC-01-treated group. The iPSC-NP treatment of spinal cord injury (SCI) provided the highest recovery of locomotor function due to robust graft survival and its effect on tissue sparing, reduction of glial scarring, and increased axonal sprouting.

The antiproliferative effect of Quercetin in cancer cells is mediated via inhibition of the PI3K-Akt/PKB pathway.

BACKGROUND: The tumor suppressor gene PTEN, mutated in 40-50% of patients with brain tumors, especially those with glioblastomas, maps to chromosome 10q23.3 and encodes a dual-specificity phosphatase. PTEN exerts its effects partly via inhibition of protein tyrosine kinase B (Akt/Protein Kinase B), which is involved in the phosphatidylinositol (PtdIns) 3-kinase (PI3K)-mediated cell-survival pathway. The naturally occurring bioflavonoid Quercetin (Qu) shares structural homology with the commercially available selective PI3K inhibitor, LY 294002 (LY). Here, the effects of Qu on the Akt/PKB pathway were evaluated. MATERIALS AND METHODS: The human breast carcinoma cell lines, HCC1937, with homozygous deletion of the PTEN gene, and T47D, with intact PTEN, were time-treated with Qu or LY and analyzed for activated levels of Akt by measuring phospho-Akt (p-Akt) levels using immunoblotting analysis. To detect p-Akt, the T47D cells were treated with EGF prior to treatment with or without Qu or LY Cell proliferation after 24-h treatment with Qu or LY was quantified by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. RESULTS: Treatment with Qu (25 microM) for 0.5, 1 and 3 h completely suppressed constitutively activated Akt/PKB phosphorylation at Ser-473 in HCC1937 cells. Pre-exposing T47D cells to Qu (25 microM) or LY (10 microM) abrogated EGF-induced Akt/PKB phosphorylation at Ser-473. Both Qu (100 microM) and LY (50 microM) treatments for 24 h significantly decreased cell proliferation, as shown by the MTT assay. CONCLUSION: Pharmacologically safe doses of the naturally occurring bioflavonoid Qu inhibit the PI3K-Akt/PKB pathway, in a manner similar to that of the commercially available LY. Overall, our results indicated that Qu inhibited the constitutively activated-Akt/PKB pathway in PTEN-null cancer cells, and suggest that this compound may have therapeutic benefit against tumorigenesis and cancer progression.

Revisiting the role of p53 in primary and secondary glioblastomas.

Glioblastoma multiforme (GBM) develops from astrocytes and is the most aggressive primary cancer in humans. Invading cells grow rapidly and form their own blood vessels making them difficult to surgically remove or treat. GBM may develop de novo (primary) or through progression from a low-grade or anaplastic astrocytoma (secondary). Mutational inactivation of the p53 gene and presence of aberrant p53 expression are reported in GBM, suggesting that p53 has a role in tumor progression. This study of seven de novo GBM and four secondary GBM patients, indicated that nine out of eleven (82%) had overexpression of p53. Our histopathological analysis showed that the expression of p53 in three out of four (75%) secondary GBM was confined to the nucleus and the p53 positive cells were randomly distributed throughout the tumor. The expression of p53 in four out of seven (57%) de novo GBM was cytoplasmic, diffusive, and confined to the perivascular region of the tumor. In two (29%) de novo samples both nuclear as well as cytoplasmic staining that was not confined to the perivascular area was observed. The results suggest that cytoplasmic p53 may contribute to the formation and maintenance of de novo GBM by virtue of its control of the vasculature of tumors. Furthermore, cytoplasmic p53 may reflect an association of p53 with Cullin 7, PARC, or with the sequestering partner of p53, mortalin. These results underscore the significance of p53 in the tumorigenesis of de novo GBM.

Meningioangiomatosis associated with neurofibromatosis: report of 2 cases in a single family and review of the literature.

BACKGROUND: Meningioangiomatosis (MA) is a rare benign disorder. It may occur sporadically or in association with neurofibromatosis (NF). The sporadic type typically presents with seizures, whereas that associated with NF is often asymptomatic. Of the 100 cases reported, only 14 are associated with NF. We now report 2 additional cases of MA associated with neurofibromatosis 2 (NF2) in a single family, with one occurring in the cerebellum. The etiology, pathology, and imaging features of MA are presented. CASE DESCRIPTION: A 38-year-old woman (patient 1) presented with a 4-month history of ataxia. She had been diagnosed previously with NF2. Magnetic resonance imaging (MRI) scans of the brain revealed bilateral acoustic neuromas and multiple calcified intracranial lesions. Her 13-year-old daughter (patient 2) presented with complex partial seizures. MRI scans of the brain revealed bilateral acoustic neuromas and a right parietal mass. Patient 1 underwent a suboccipital craniotomy to resect the right-sided acoustic neuroma. A small portion of normal-appearing cerebellar cortex was resected to avoid undue retraction. Histopathologic examination showed the presence of a lesion consistent with MA. Patient 2 underwent a right temporal-parietal craniotomy to remove the enhancing epileptogenic right posterior temporoparietal lesion. Histopathologic analysis showed a lesion consistent with meningioma and MA. CONCLUSIONS: MA has been reported infrequently in association with NF2. We now report 2 cases of MA associated with NF2 in one family, and we add the cerebellum to possible locations of occurrence. MA should be considered in the differential diagnosis of cortical lesions, particularly in patients with NF2.

Hyponatremia and cerebrovascular spasm in aneurysmal subarachnoid hemorrhage.

BACKGROUND: Hyponatremia develops in approximately a third of patients with aneurysmal subarachnoid hemorrhage (SAH). Studies have been conflicting about the association between hyponatremia and cerebrovascular spasm (CVS). AIMS: To investigate whether hyponatremia can signal the onset of CVS. SETTINGS AND DESIGN: Retrospective chart review of all patients with SAH treated at a tertiary-care university hospital from January to May 2002. MATERIALS AND METHODS: 106 patients were included in the study. Serum sodium levels were recorded from days 1 to 14 of hospitalization. Hyponatremia was defined as serum sodium level<135 meq/l and a fall in sodium level of >4 meq/l from the admission sodium level. The presence of CVS was determined by transcranial doppler sonography. Patients were assigned to one of four groups based on the presence or absence of CVS and hyponatremia. STATISTICAL ANALYSIS: Student's t-test was used for comparison of means. A logistical regression model was constructed and odds ratios (OR) were calculated. RESULTS: 41 patients developed hyponatremia and 44 developed CVS. Among the 41 with hyponatremia, 22 (54%) had evidence of CVS, whereas among the 65 patients without hyponatremia, 22 (34%) had evidence of CVS (P=0.023). Among those with hyponatremia, the mean sodium drop was 7.9 meq/L in those with CVS compared to 7.0 meq/L in those without CVS (P=0.068). More than half of those with hyponatremia and CVS (13/22) developed hyponatremia at least a day before CVS was diagnosed. CONCLUSION: In patients with SAH, hyponatremia is associated with a significantly greater risk of developing CVS and may precede CVS by at least one day.