Enhancing tissue repair in annulus fibrosus defects of the intervertebral disc: analysis of a bio-integrative annulus implant in an in-vivo ovine model.

Annulus fibrosus repair techniques for the intervertebral disc (IVD) address the unsolved problem of reherniation after IVD herniation and might facilitate the development of nucleus pulposus replacement techniques for IVD diseases. This study investigates the suitability of a bio-integrative annulus implant.Standardized box defects were applied to the annulus L3/4 and L4/5 of 16 sheep, followed by randomized insertion of the textile polyglycolic acid/polyvinylidene fluoride annulus implant in one of the defects. Explantation was conducted after 2, 6 and 12 weeks, followed by provocative pressure testing and histological analysis. At 2 weeks' follow-up, all specimens of the control defect group demonstrated uncontained herniated nucleus pulposus tissue in the annulus defects. For the treated specimens, the annulus implant consistently provided an effective barrier for herniating nucleus pulposus tissue, with no implant dislocation at all time-points. After 2 weeks, a homogeneous cell infiltration of the annulus implant was observed, leading to a progressive directional matrix build-up. Repair tissue thickness was significantly stronger with the annulus implant at all follow-ups (p < 0.01). No pronounced foreign body reaction and no difference in the amount of supra-annular scar tissue over the defect sites were observed. The implantation procedure inflicted annulus damage adjacent to the defect. At later time-points, however, no difference in comparison with the control defect group was evident. The investigated biointegrative annulus implant showed promising results with regard to biointegration, enhancement of repair tissue and function as a mechanical barrier in an ovine model.

Spinal metastasis of gliosarcoma: array-based comparative genomic hybridization for confirmation of metastatic spread.

We report a 64-year-old woman who underwent craniotomy and gross total resection of a left frontal lobe tumor initially diagnosed as glioblastoma. Multiple wound revisions were necessary due to repeated wound healing disorders under concomitant radio-chemotherapy. After 9 months there was local cranial tumor recurrence, requiring re-operation. Thereafter, temozolomide monotherapy was implemented. Histologically, a shift from glial to mesenchymal differentiation was observed in the recurrent tumor, resulting in the diagnosis of gliosarcoma. A further 9 months later a thoracic spinal tumor occurred requiring emergency tumor resection. Analysis showed a mesenchymal tumor without definite glial component. Being resistant to local radiation therapy, symptomatic local spinal tumor progression was observed within 1 month requiring re-resection. There was no response to chemotherapy with bevacizumab and irinotecan. Considering the pronounced sarcoma-like differentiation, a sarcoma chemotherapy regime with doxorubicin was initiated. This was also to no avail; the disease progressed and recurred at both the spinal and cerebral locations, respectively. This ambiguous tumor characteristic and therapy resistance encouraged us to retrospectively perform molecular and array-based comparative genomic hybridization (aCGH) analysis on the extirpated cerebral and spinal tumors. Tumors from both locations showed a consistent cytogenetic signature of gain of chromosome 7, and losses of chromosomes 10 and 13. This novel report of aCGH analysis of spinal gliosarcoma metastasis and the correlation to the clinical disease course shows that genotypic profiling may serve as a supplementary diagnostic tool in improving our knowledge of the biologic behavior of rare tumor variants.

Mutant BRAF V600E protein in ganglioglioma is predominantly expressed by neuronal tumor cells.

Ganglioglioma is a rare CNS tumor with a benign biological behavior. Recently, the BRAF V600E mutation was identified in approximately 20 % of gangliogliomas. Here, we analyzed a total of 71 gangliogliomas for BRAF V600E mutational status by VE1 immunohistochemistry and direct DNA sequencing. The BRAF V600E mutation was detected in 41/71 (58 %) gangliogliomas by immunohistochemistry. DNA sequencing was concordant in 60 of 62 analyzed cases. BRAF status was compared with clinical, histological and immunohistochemical data. Presence of the BRAF V600E mutation was associated with expression of synaptophysin in the tumor (p = 0.0008), presence of dysplastic neurons (p = 0.011) and lymphocytic cuffs (p = 0.018), and with younger age (p = 0.0054). Extensive hemosiderin deposition within the tumor was significantly associated with BRAF wild-type status (p = 0.042). No significant association was found with proliferation (p = 0.053), presence of phospho ERK (p = 0.1) or senescence marker p16(INK4a) (p = 0.22). Using VE1, we localized the BRAF V600E-mutated protein predominantly to the neuronal compartment, indicating that BRAF mutations occur in cells that have the capacity to differentiate into ganglionic cells. In many cases mutant BRAF is additionally expressed by the glial compartment, indicating that in these cases the cell targeted by BRAF mutation was likely capable of differentiating along both the ganglionic and glial lineages. No cases with an exclusive expression of BRAF V600E in the glial compartment were observed. Thus, using VE1 we identified the neuronal compartment as an essential part of this mixed glioneuronal tumor.

Assessment of BRAF V600E mutation status by immunohistochemistry with a mutation-specific monoclonal antibody.

Activating mutations of the serine threonine kinase v-RAF murine sarcoma viral oncogene homolog B1 (BRAF) are frequent in benign and malignant human tumors and are emerging as an important biomarker. Over 95% of BRAF mutations are of the V600E type and specific small molecular inhibitors are currently under pre-clinical or clinical investigation. BRAF mutation status is determined by DNA-based methods, most commonly by sequencing. Here we describe the development of a monoclonal BRAF V600E mutation-specific antibody that can differentiate BRAF V600E and wild type protein in routinely processed formalin-fixed and paraffin-embedded tissue. A total of 47 intracerebral melanoma metastases and 21 primary papillary thyroid carcinomas were evaluated by direct sequencing of BRAF and by immunohistochemistry using the BRAF V600E mutation-specific antibody clone VE1. Correlation of VE1 immunohistochemistry and BRAF sequencing revealed a perfect match for both papillary thyroid carcinomas and melanoma metastases. The staining intensity in BRAF V600E mutated tumor samples ranged from weak to strong. The generally homogenous VE1 staining patterns argue against a clonal heterogeneity of the tumors investigated. Caution is essential when only poorly preserved tissue is available for VE1 immunohistochemical analysis or when tissues with only little total BRAF protein are analyzed. Immunohistochemistry using antibody VE1 may substantially facilitate molecular analysis of BRAF V600E status for diagnostic, prognostic, and predictive purposes.

Analysis of BRAF V600E mutation in 1,320 nervous system tumors reveals high mutation frequencies in pleomorphic xanthoastrocytoma, ganglioglioma and extra-cerebellar pilocytic astrocytoma.

Missense mutations of the V600E type constitute the vast majority of tumor-associated somatic alterations in the v-RAF murine sarcoma viral oncogene homolog B1 (BRAF) gene. Initially described in melanoma, colon and papillary thyroid carcinoma, these alterations have also been observed in primary nervous system tumors albeit at a low frequency. We analyzed exon 15 of BRAF spanning the V600 locus by direct sequencing in 1,320 adult and pediatric tumors of the nervous system including various types of glial, embryonal, neuronal and glioneuronal, meningeal, adenohypophyseal/sellar, and peripheral nervous system tumors. A total of 96 BRAF mutations were detected; 93 of the V600E type and 3 cases with a three base pair insertion between codons 599 and 600. The highest frequencies of BRAF (V600E) mutations were found in WHO grade II pleomorphic xanthoastrocytomas (42/64; 66%) and pleomorphic xanthoastrocytomas with anaplasia (15/23; 65%), as well as WHO grade I gangliogliomas (14/77; 18%), WHO grade III anaplastic gangliogliomas (3/6) and pilocytic astrocytomas (9/97; 9%). In pilocytic astrocytomas BRAF (V600E) mutation was strongly associated with extra-cerebellar location (p = 0.009) and was most frequent in diencephalic tumors (4/12; 33%). Glioblastomas and other gliomas were characterized by a low frequency or absence of mutations. No mutations were detected in non-glial tumors, including embryonal tumors, meningiomas, nerve sheath tumors and pituitary adenomas. The high mutation frequencies in pleomorphic xanthoastrocytomas, gangliogliomas and extra-cerebellar pilocytic astrocytomas implicate BRAF (V600E) mutation as a valuable diagnostic marker for these rare tumor entities. Future clinical trials should address whether BRAF (V600E) mutant brain tumor patients will benefit from BRAF (V600E)-directed targeted therapies.

Fundamental efforts toward the development of a therapeutic cocktail with a manifold ameliorative effect on hepatic ischemia/reperfusion injury.

OBJECTIVE: Ischemia/reperfusion injury is mediated by various mechanisms. The present study was designed to evaluate the effect of a multiple pharmacological approach toward ischemia/reperfusion injury reduction. METHODS: The left liver lobe of Sprague-Dawley rats underwent normothermic ischemia for 90 minutes after a cocktail (glycine, taurine, alanine, arginine, and prednisolon) intravenous administration. Controls received normal saline. Liver injury (transaminases, histology) and cellular activation [Kupffer cell phagocytosis, production of tumor necrosis factor-alpha (TNFalpha), and prostaglandin E-2 (PGE(2))], as well as microcirculation and leukocyte-endothelial interaction (in vivo microscopy), were assessed. RESULTS: Whereas in controls a substantial increase of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase to 2,341+/-477, 1,442+/-262, and 1,973+/-73 U/L, respectively, was measured eight hours after reperfusion, the cocktail significantly reduced the increase of enzymes by 33-80% (P<0.05). Further, necrosis, index of liver damage, and index of leukocyte infiltration significantly decreased after the cocktail (P<0.05). Moreover, the cocktail improved acinar and sinusoidal perfusion, while the sinusoidal diameters, leukocyte-endothelial interaction, Kupffer cell phagocytic activity, and TNFalpha/PGE(2) serum levels were significantly reduced, the latter by 86% and to 1.64-fold, respectively. CONCLUSIONS: This study depicts that multifaceted pharmacological tackling of ischemia/reperfusion injury is feasible and protects rat liver tissue from warm ischemia/reperfusion injury.