Storage and purification adaptations for the isolation of total RNA from the dura mater.

BACKGROUND: RNA extraction is a step that precedes several molecular techniques. The fibrous tissue, more specifically the dura mater, has several limitations in routine protocols, and lacks optimization protocols to overcome these problems. OBJECTIVE: To test stock reagents and purification kits, optimizing commercial kit protocols for RNA extraction from the dura mater. METHODS: Dura mater samples were obtained from eight Wistar rats and maintained in two different stabilizers. The samples were purified using four different protocols, and the RNA was evaluated for the yield and purity in NanoDrop 2000 (Thermo Scientific, Wilmington, DE, United States). Beta-actin gene was used for analyzing gene expression, since is one of the most used reference genes. RESULTS: The RNA preservation was similar in both stabilizers. The addition of an incubation step prior the purification protocols allowed better tissue digestion and RNA recovery. The RNA purified using the protocols membrane-based showed higher quality than liquid-liquid purification. This impact was observed in the 3-week evaluation using RT-qPCR. CONCLUSION: Stabilizers are efficient for RNA preservation and membrane-based purification protocols are more suitable for RNA recovery from dura mater tissue, allowing the evaluation of gene expression in this type of tissue. Adaptations in the dura mater RNA extraction protocol differ from the pre-established protocols because it takes into account the peculiarity of fibrous tissue and low cellularity. In addition to providing a low-cost mechanism, based on techniques that are part of the laboratory routine, it is possible to improve the quality of the extracted material, ensuring greater efficiency in the use of subsequent techniques.

ANTECEDENTES: A extração de RNA é uma etapa que antecede várias técnicas moleculares. O tecido fibroso, mais especificamente a dura-máter, apresenta várias limitações nos protocolos de rotina e carece de protocolos de otimização para superar estes problemas. OBJETIVO: Testar reagentes de estoque e kits de purificação, otimizando protocolos de kits comerciais para extração de RNA da dura-máter. MéTODOS: Amostras de dura-máter foram obtidas de oito ratos Wistar e mantidas em dois estabilizadores diferentes. As amostras foram purificadas em quatro protocolos diferentes e o RNA foi avaliado quanto ao rendimento e pureza no NanoDrop 2000 (Thermo Scientific, Wilmington, DE, United States). O gene da beta-actina foi utilizado para analisar a expressão gênica, uma vez que é um dos genes de referência mais utilizados. RESULTADOS: A preservação do RNA foi semelhante em ambos os estabilizadores. A adição de uma etapa de incubação antes dos protocolos de purificação permitiu uma melhor digestão do tecido e recuperação de RNA. O RNA purificado pelos protocolos baseados em membrana apresentou qualidade superior ao da purificação líquido-líquido. Este impacto foi observado na avaliação de três semanas usando RT-qPCR. CONCLUSãO: Os estabilizadores são eficientes para preservação do RNA e os protocolos de purificação baseados em membrana são mais adequados para recuperação de RNA do tecido da dura-máter, permitindo a avaliação da expressão gênica neste tipo de tecido. As adaptações no protocolo de extração de RNA da dura-máter diferem dos protocolos preestabelecidos porque leva em consideração a peculiaridade do tecido fibroso e com baixa celularidade. Além de fornecer um mecanismo de baixo custo, baseado em técnicas que fazem parte da rotina laboratorial, é possível melhorar a qualidade do material extraído, garantindo maior eficácia no uso de técnicas subsequentes.

Novel histopathological classification of meningiomas based on dural invasion.

AIMS: Histological invasion into the adjacent brain parenchyma is frequently investigated in meningioma because it is an important morphological criterion for grade II meningioma according to the 2016 WHO classification. However, few studies have focused on dural invasion of meningiomas. Herein, we propose a novel histopathological classification based on dural invasion of meningiomas. METHODS: Forty-nine cases with WHO grade I meningiomas who underwent Simpson grade I removal were collected. After the meningeal layer (ML) and periosteal layer (PL) of dura mater were visualised by Masson's trichrome stain, we evaluated the depth (to the ML and PL) and the patterns (1, expanding; 2, infiltrating) of dural invasion of meningiomas using serial paraffin sections. Invasion-associated markers, including Ki-67, matrix metalloproteinase (MMP)-1, MMP-9 and MMP-13, aquaporin 1 and Na-K-2Cl cotransporter, were quantitatively analysed by immunohistochemistry. RESULTS: Thirty-five cases (71.4%) showed the dural invasion. In 27 of these 35 cases (77.1%), dural invasion was localised in ML. Type 1 (expanding type) and type 2 (infiltrating type) invasions were observed in 23 and 12 cases, respectively. The recurrence rate in cases with type 2 invasion was significantly higher than that in cases with type 1 invasion. The percentage of MMP-1-positive tumour cells was also significantly higher in cases with dural invasion than those without, suggesting involvement of MMP-1 in dural invasion. CONCLUSIONS: We quantitatively evaluated the depth and patterns of dural invasion in meningiomas. The patterns of dural invasion were associated with meningioma recurrence.

Radiological evaluation of Hyperostosis frontalis interna: is it of clinical importance?

Hyperostosis frontalis interna (HFI) presents irregular thickening of the frontal bone. Even though HFI is frequently seen during routine radiological imaging, it usually remains unrecorded owing to a common belief that it just represents an incidental finding or anatomical variant. Recent studies implied that HFI may be clinically relevant. Etiology of HFI is still debated, while presumptions are mainly based on altered sex steroids impact on skull bone growth. Some authors implied that frontal bone might be particularly affected by this condition due to specificity of its underlying dura. In this paper we present a 27-years old female patient with a treatment resistant headache. Head CT showed massive, irregular bony mass, with lobulated contours arising from the right frontal bone, but did not cross the fronto-parietal suture, spearing the superior sagittal sinus and skull midline. After surgery, histopathological analysis of the frontal bone sample in our patient showed thickening pattern similar to those described in micro-CT studies of HFI. Furthermore, in an attempt to test speculation of the possible role of estrogen in pathogenesis of HFI, we investigated the expression of α-estrogen receptors on dura of the frontal region. These analyses confirmed nuclear expression of estrogen on frontal region dural tissue, supporting previous speculation of the development mechanisms of HFI and contributing to a better understanding of this common condition of the frontal bone. Additionally, the presence of HFI may result in severe symptomatology, which could be misinterpreted and related to other disorders if HFI is not radiologicaly recognized and reported.

Less Use of the Bipolar Cautery can Prevent Postlaminectomy Epidural Fibrosis: An Experimental Study in Rats.

AIM: To investigate the role of bipolar electrocautery in the occurrence of epidural fibrosis following lumbar spine laminectomy in a rat model. MATERIAL AND METHODS: Fourteen male Sprague-Dawley rats (age: 4-6 months, weight: 250-300 g) were randomly divided into two groups, a bipolar group (Group I) and a control group (Group II). Laminectomy was performed between the L1 and L3 levels. In Group I (n=7), a laminectomy was carried out and soft tissue around the spinal cord was coagulated by using a bipolar electrocautery. In the control group (n=7), only laminectomy was performed. The animals were sacrificed 4 weeks after surgery, and post-laminectomy epidural fibrosis (PLEF) was evaluated. Macropathological, qualitative and quantitative histological evaluations as well as immunohistochemical staining including transforming growth factor-ß (TGF-ß), collagen I and collagen III were performed. RESULTS: The numbers of TGF-ß positive cells staining (PCS) were 3.00 ± 0.46 for Group I and 1.00 ± 0.52 for Group II. The numbers of collagen I PCS were 2.00 ± 0.93 for Group I and 1.25 ± 0.46 for Group II. The numbers of collagen III PCS were 2.25 ± 0.76 for Group I, 1.25 ± 0.46 for Group II, and TGF-ß PCS than Group II (p≤0.05). Compared with the control group, Group I's formation of epidural fibrosis was significantly increased. CONCLUSION: Our study clearly demonstrated that the use of bipolar cauterisation is associated with increased PLEF in the experimental animal model. Thus, limiting the use of bipolar cauterisation may be effective in reducing this complication.

Fluorescently-labeled fremanezumab is distributed to sensory and autonomic ganglia and the dura but not to the brain of rats with uncompromised blood brain barrier.

BACKGROUND: The presence of calcitonin gene-related peptide and its receptors in multiple brain areas and peripheral tissues previously implicated in migraine initiation and its many associated symptoms raises the possibility that humanized monoclonal anti-calcitonin gene-related peptide antibodies (CGRP-mAbs) can prevent migraine by modulating neuronal behavior inside and outside the brain. Critical to our ability to conduct a fair discussion over the mechanisms of action of CGRP-mAbs in migraine prevention is data generation that determines which of the many possible peripheral and central sites are accessible to these antibodies - a question raised frequently due to their large size. MATERIAL AND METHODS: Rats with uncompromised and compromised blood-brain barrier (BBB) were injected with Alexa Fluor 594-conjugated fremanezumab (Frema594), sacrificed 4 h or 7 d later, and relevant tissues were examined for the presence of Frema594. RESULTS: In rats with uncompromised BBB, Frema594 was similarly observed at 4 h and 7 d in the dura, dural blood vessels, trigeminal ganglion, C2 dorsal root ganglion, the parasympathetic sphenopalatine ganglion and the sympathetic superior cervical ganglion but not in the spinal trigeminal nucleus, thalamus, hypothalamus or cortex. In rats with compromised BBB, Frema594 was detected in the cortex (100 µm surrounding the compromised BBB site) 4 h but not 7 d after injections. DISCUSSION: Our inability to detect fluorescent (CGRP-mAbs) in the brain supports the conclusion that CGRP-mAbs prevent the headache phase of migraine by acting mostly, if not exclusively, outside the brain as the amount of CGRP-mAbs that enters the brain (if any) is too small to be physiologically meaningful.

Activation of pial and dural macrophages and dendritic cells by cortical spreading depression.

OBJECTIVE: Cortical spreading depression (CSD) has long been implicated in migraine attacks with aura. The process by which CSD, a cortical event that occurs within the blood-brain barrier (BBB), results in nociceptor activation outside the BBB is likely mediated by multiple molecules and cells. The objective of this study was to determine whether CSD activates immune cells inside the BBB (pia), outside the BBB (dura), or in both, and if so, when. METHODS: Investigating cellular events in the meninges shortly after CSD, we used in vivo two-photon imaging to identify changes in macrophages and dendritic cells (DCs) that reside in the pia, arachnoid, and dura and their anatomical relationship to TRPV1 axons. RESULTS: We found that activated meningeal macrophages retract their processes and become circular, and that activated meningeal DCs stop migrating. We found that CSD activates pial macrophages instantaneously, pial, subarachnoid, and dural DCs 6-12 minutes later, and dural macrophages 20 minutes later. Dural macrophages and DCs can appear in close proximity to TRPV1-positive axons. INTERPRETATION: The findings suggest that activation of pial macrophages may be more relevant to cases where aura and migraine begin simultaneously, that activation of dural macrophages may be more relevant to cases where headache begins 20 to 30 minutes after aura, and that activation of dural macrophages may be mediated by activation of migratory DCs in the subarachnoid space and dura. The anatomical relationship between TRPV1-positive meningeal nociceptors, and dural macrophages and DCs supports a role for these immune cells in the modulation of head pain. Ann Neurol 2018;83:508-521.

Primary dura-based synovial sarcoma of the parafalcine region of brain.

Dura-based intracranial neoplasms include a wide range of primary and metastatic tumors, varying in their clinical, radiologic, morphologic, and immunophenotypic characteristics. At this anatomic location, sarcomas are rare, however, they exhibit close morphologic resemblances to meningioma. Herein we describe the third case of primary synovial sarcoma of the parafalcine region in a50-years-old female, who presented with left-sided hemiplegia. The radiologic survey revealed a 5.5cm×5.8cm contrast enhancing dura-based mass at the right parafalcine region with meningeal enhancement and edema in the surrounding areas. Morphologic evaluation exhibited a high-grade spindle cell neoplasm, with focal hemangiopericytomatous pattern. The tumor cells were diffusely immunoreactive for CD99, Bcl2, TLE-1, and vimentin. The Ki-67 proliferation index was 40%. Pancytokeratin was focally positive. Epithelial membrane antigen, progesterone receptor, CD34, S-100, and glial fibrillary acidic protein were negative. Fluorescence in situ hybridization confirmed tumor specific translocation t(X;18)(p11.2;q11.2). Hence, final diagnosis of synovial sarcoma was rendered. Primary meningeal synovial sarcoma should be considered in the differential of aggressive and high-grade dura-based tumors in view of their relative chemosensitivity and future prospect of a molecular target-based therapy. The index case highlights the importance of an extensive pathologic analysis of high-grade mesenchymal lesions of the meninges to arrive at a definitive diagnosis and differentiate such tumors from other usual dura-based tumors, which has important therapeutic and prognostic implications.

Anatomy and immunochemical characterization of the non-arterial peptidergic diffuse dural innervation of the rat and Rhesus monkey: Implications for functional regulation and treatment in migraine.

Objective The interplay between neuronal innervation and other cell types underlies the physiological functions of the dura mater and contributes to pathophysiological conditions such as migraine. We characterized the extensive, but understudied, non-arterial diffuse dural innervation (DDI) of the rat and Rhesus monkey. Methods We used a comprehensive integrated multi-molecular immunofluorescence labeling strategy to extensively profile the rat DDI and to a lesser extent that of the Rhesus monkey. Results The DDI was distributed across a dense, pervasive capillary network and included free nerve endings of peptidergic CGRP-expressing C fibers that were closely intertwined with noradrenergic (NA) sympathetic fibers and thin-caliber nonpeptidergic "C/Aδ" fibers. These newly identified C/Aδ fibers were unmyelinated, like C fibers, but expressed NF200, usually indicative of Aδ fibers, and uniquely co-labeled for the CGRP co-receptor, RAMP1. Slightly-larger caliber NF200-positive fibers co-labeled for myelin basic protein (MBP) and terminated as unbranched corpuscular endings. The DDI peptidergic fibers co-labeled for the lectin IB4 and expressed presumably excitatory α1-adrenergic receptors, as well as inhibitory 5HT1D receptors and the delta opioid receptor (δOR), but rarely the mu opioid receptor (µOR). Labeling for P2X3, TRPV1, TRPA1, and parasympathetic markers was not observed in the DDI. Interpretation These results suggest potential functional interactions, wherein peptidergic DDI fibers may be activated by stress-related sympathetic activity, resulting in CGRP release that could be detected in the circulation. CGRP may also activate nonpeptidergic C/Aδ fibers that are likely mechanosensitive or polymodal, leading to activation of post-synaptic pain transmission circuits. The distribution of α1-adrenergic receptors, RAMP1, and the unique expression of the δOR on CGRP-expressing DDI fibers suggest strategies for functional modulation and application to therapy.

Type I Cutaneous Meningioma (Rudimentary Meningocele) With Intradural Attachment to the Phylum Terminale.

Cutaneous meningiomas (CM) are a small subset of meningiomas, further classified into three subtypes. The authors present a 15-year-old male with a symptomatic congenital type I CM and describe the histopathological and immunohistochemical findings. To the authors' knowledge, this is the first report of an extraspinal lumbar type I CM with intradural attachment to the phylum terminale.

The Impact of Age Upon Healing: Absolute Quantification of Osteogenic Genes in Calvarial Critical-Sized Defects.

BACKGROUND: The current study was performed to elucidate changes in growth factor expression over time in critical-sized calvarial defects in rats from infancy to skeletal maturity. MATERIALS AND METHODS: Critical-sized parietal defects of 5, 6, and 8 mm were created in postnatal day 6 (P6), postnatal day (P20), and postnatal day (P84) adult rats, respectively. Dura was harvested at 3, 7, or 14 days after surgery, and serial micro-computed tomography imaging was performed through 12 weeks postoperatively. Absolute quantitative polymerase chain reaction was performed for Bone Morphogenic Protein-2 (BMP-2), Fibroblast Growth Factor-2 (FGF-2), Insulin-like Growth Factor-1 (IGF-1), and Transforming Growth Factor-ß1 (TGF-ß). RESULTS: The P6 (6-d-old) rats showed the greatest difference in gene expression between the dura derived from the defect side and the dura derived from the control side, demonstrating significant differences in TGF-ß1, BMP-2, IGF-1, and FGF-2 at various time intervals. Absolute gene expression in the defect dura was highest in the P6 rats and declined with age. Significant differences were noted at limited time points in the P20 rats for TGF-ß1 and BMP-2 as well as in the P84 rats for TGF-ß1. TGF-ß1 was the only gene studied that showed significant differences at postoperative days 3, 7, and 14 in varying age groups. CONCLUSIONS: The P6 rats have a higher osteogenic potential accompanied by a more vigorous alteration in growth factor expression compared with the P20 or P84 rats. Decrease in BMP-2 and FGF-2 as well as relative increase in TGFß-1 messenger RNA were observed in healing defects. These data provide valuable insight into the mechanism of healing of critical-sized defects and may be of use to engineer factor-releasing implants to correct skull defects.

Detectability and medico-legal value of the gunshot residues in the intracorporeal channel.

The application of the histochemical stain of sodium rhodizonate to the entrance wound for the detection of the lead (Pb) residues coming from the gunshot may be affected by false positive cases due to the contamination of the environmental Pb. The aim of the Authors is to histochemically search the Pb of GSR in a region which should be more protected by the contamination: the intracorporeal channel. Two hundreds and eighteen serial histological specimens of the intracorporeal channels coming from 25 subjects (dead due to gunshots and being autopsied at the Section of Legal Medicine of the Milan University, in the years 2013-2014) were stained with the sodium rhodizonate and sodium rhodizonate in acid environment (HCl 5%), and then observed by the microscope. The sodium rhodizonate showed a positivity for the Pb residues in the intracorporeal channel, with the detection of the particles within the first 2 cm beyond the entrance wound in 6 cases over the total number of 25 (24%). Victims were characterized by common features: short-barreled weapon; contact shots or short-distance shots; involvement of regions that were not covered by clothing; preservation of the microscopic structure of organs interested by the intracorporeal channel. The searching of GSR in the intracorporeal channel, even in conditions securing a high sensitivity, could represent an important test for the discrimination between an environmental contamination of Pb and the presence of Pb residues by GSR: once confirmed the presence of GSR in the intracorporeal channel by the histochemical analysis, the diagnostic process should require the application of the SEM-EDX for the confirmation of the results. Although not yet studied, this combination could be applied to cadavers exposed to the environment, with advanced post-mortal phenomena permitting at least the suspects of the existence of gunshot wounds at the macroscopic autopsy evaluation. Indeed, in some cases, the putrefaction is so advanced that no suspect of gunshot injuries could be derived from the soft tissue.

Squash Cytology of a Dural-Based High-Grade Chondrosarcoma May Mimic That of Glioblastoma in the Central Nervous System.

BACKGROUND: Intracranial chondrosarcoma is rare, and most cases occur in the skull base. Intradural chondrosarcoma is even rarer. CASE: Here, we describe a case of dural chondrosarcoma with a radiation history for nasopharyngeal carcinoma and a radical prostatectomy for prostatic cancer 15 and 8 years earlier, respectively. A 67-year-old man presented with a 3-week memory disturbance and dysarthria. Computed tomography and magnetic resonance images of the brain revealed a dural-based mass in the left temporal area. Under the impression of a glioblastoma, a resection and an intraoperative squash cytology were done. A necrotic dirty background as well as bluish-to-pinkish myxoid stroma were characteristic; the nuclei of highly pleomorphic tumor cells were hyperchromatic to vesicular with an occasional ground-glass appearance. The cytoplasm was of an eosinophilic hyalinized condensed morphology with an occasional granular appearance. Histologically, the lobulated mass was composed of hypercellular lobules of well-differentiated chondrocytes intermixed with anaplastic pleomorphic cells and diagnosed as a conventional grade III chondrosarcoma. These cells were immunoreactive for D2-40, S-100 protein and vimentin. Brain invasion was also found. CONCLUSION: Albeit rare, dural-based chondrosarcomas should be considered in the differential diagnosis for meningeal tumors, especially in the case of previous radiation therapy.

Unusual clear cell, lymphoplasmacyte-rich, dural-based tumor with divergent differentiation: a tricky case mimicking a meningioma.

We describe an unusual case of a recurrent dural neoplasm, previously diagnosed as meningioma. Histopathologically, the tumor is characterized by aggregates of divergently differentiated clear cells embedded in an abundant lymphoplasmacyte-rich stroma, mimicking a lymphoplasmacyte-rich meningioma. This study focuses on the histologic and immunohistochemical characterization of a unique dural-based tumor and provides useful guidelines for differentiating meningioma from other uncommon dural-based neoplasms. We propose that this recurrent dural neoplasm is a distinctive entity and, therefore, enlarges the spectrum of dural-based neoplasms that enter the differential diagnosis with meningiomas. Awareness of this tumor entity could prove useful for appropriate patient management.

Esophageal squamous cell carcinoma with dural and bone marrow metastases.

Patients with esophageal squamous cell carcinoma generally present at an advanced stage at the time of diagnosis. The most common sites of visceral metastasis are the lung, liver and bone, but brain and bone marrow involvement is exceedingly rare. Herein, we report a 62-year-old man with a 4-wk history of progressive low back pain with radiation to bilateral lower legs, dysphagia and body weight loss. Esophageal squamous cell carcinoma with regional lymph node, liver and bone metastases was diagnosed. He underwent concurrent chemoradiotherapy and got a partial response. Four months later, he complained of headache, diplopia and severe hearing impairment in the left ear. There was no evidence for bacterial, fungal, tuberculous infection or neoplastic infiltration. Magnetic resonance imaging of the brain demonstrated thickening and enhancement of bilateral pachymeninges and multiple enhancing masses in bilateral skull. Dural metastasis was diagnosed and he received whole brain irradiation. In addition, laboratory examination revealed severe thrombocytopenia and leucopenia, and bone marrow study confirmed the diagnosis of metastatic squamous cell carcinoma. This is the first described case of esophageal squamous cell carcinoma with dural and bone marrow metastases. We also discuss the pathogenesis of unusual metastatic diseases and differential diagnosis of pachymeningeal thickening.

Preliminary exploration of the development of a collagenous artificial dura mater for sustained antibiotic release.

BACKGROUND: Intracranial infection is one of the most common complications of open craniocerebral injury and of conventional craniotomy in neurosurgery. The presence of blood-brain barrier leads to lower drug concentrations in the cerebrospinal fluid than in the venous blood. Increasing the intravenous dosage or frequency carries the risk of systemic adverse reactions or infections in other parts of the body. Developing an artificial dura mater (ADM) for sustained antibiotic release for use during neurosurgery can solve the problems perfectly. METHODS: Three types of drug-loaded ADMs made of collagen and containing cefuroxime sodium, ceftriaxone sodium, or norvancomycin were prepared. The antibacterial activity and sustained release characteristics of the ADMs were examined using bacteriostatic and release tests. RESULTS: Single-layered collagen based ADMs (40 mm×50 mm×5 mm) containing 18 mg cefuroxime sodium or ceftriaxone sodium were not suitable for continued development because of drug preservation and stability issues. Using smaller ADMs (20 mm×30 mm×7 mm), containing 4.86 mg of norvancomycin, with increased collagen density and a three-layered film with two outer drug-free films above and below the antibiotic layer resulted in sustained cumulative release of 2.91 mg (59.9%) of norvancomycin over 72 hours. The similar factor (f2) comparison method proved that products from a same batch were statistically significant similar (f2 > 50). CONCLUSIONS: Artificial ADMs made of collagen can be processed to provide a mature dural repair material for the sustained release of norvancomycin. This system may provide a basis for developing sustained release materials for other drugs.

Role of dopaminergic receptors in the human dura mater in the pathogenesis of headache.

AIMS: We hypothesize that dopaminergic receptors of dura mater may play a possible role in headache. MATERIALS AND METHODS: The dopaminergic receptors of cranial dura mater in man were studied by examining several dural zones (vascular, peri-vascular, inter-vascular) in different brain regions (basal, calvarial, tentorial, occipital, frontal, parietal, temporal). RESULTS: Our results demonstrate that dopaminergic receptors are present in human cranial dura mater and that these receptors show a specific morphological location. There are more dural dopaminergic receptors in the basal region than in the calvarial one. Moreover, these receptors are more abundant in the vascular and perivascular dural zone than in the intervascular one. CONCLUSIONS: The location of dopaminergic receptors in the dura mater may represent an important factor in the pathogenesis of headache. Further studies will be necessary in order to determine the role of dopaminergic system in this disease.

A rare case of malignant pediatric ectomesenchymoma arising from the falx cerebri.

Malignant ectomesenchymoma is a rare tumor arising from mature ganglion cells with immature myogenous elements, with only 4 pediatric intracranial cases having been previously reported. The authors report a rare case of intracranial malignant ectomesenchymoma originating from the falx cerebri in a 10-year-old boy. The patient presented with a 2-week history of headache, nausea, and blurry vision, with mild lateral gaze diplopia. A CT scan revealed a solitary 7.2 × 3.8-cm dural-based mass that extended along the falx. No metastatic disease was identified, and the lesion was grossly resected without complication. Pathological investigation identified single and small groups of cells in a myxoid background, with polygonal or spindle-shaped cells containing eccentric nuclei and prominent nucleoli. Immunohistochemical staining of some cells was positive for smooth-muscle actin, CD99, and vimentin, whereas other cells (often process forming) were positive for S100 protein, synaptophysin, and neurofilament protein. Staining was negative for CD138, CD45, α-fetoprotein, CK AE1/3, glial fibrillary acidic protein, CK7, CK20, CD31, CD34, myoD, and desmin. Normal immunopositivity was seen for INI-1. The Ki 67 immunostaining had < 25% reactivity. The patient was treated with a sarcoma-based chemotherapy regimen and radiation to the craniospinal axis, and was found to be without recurrence or metastatic disease at 20 months.

Use of a collagen biomatrix (TissuDura) for dura repair: a long-term neuroradiological and neuropathological evaluation.

PURPOSE: The aim of this study was to evaluate the clinical, neuroradiological, and neuropathological outcomes of patients treated with equine collagen foil (TissuDura) as a dura mater substitute during cranial and spinal neurosurgical procedures. MATERIALS AND METHODS: All patients treated at the Department of Neurosurgery of the Second University of Naples with TissuDura between 2005 and 2009 were included. Dural reconstruction was performed using TissuDura, overlaid 1 cm over the dural defect with additional fixation using fibrin glue. No surgical sutures were used. Patients underwent postoperative contrast-enhanced magnetic resonance scans at 1 week, 1 month, and 1 year after surgery to detect any cerebrospinal fluid (CSF) leaks, infections, inflammations, or CSF circulation in the surgical region. RESULTS: Dural reconstruction was performed in 74 patients, including 50 patients with tumors, two with C2 neurinoma, two with acoustic neurinoma, six with Chiari I malformation, two with severe head injury, and 12 requiring spinal surgery. Clinical and neuroradiological findings were normal and no signs of graft rejection or CSF leaks at postoperative follow-up were observed. In two cases of atypical meningioma, re-operation of the dural reconstruction was performed after 1 year. No adherences between brain and neodura were detected, and histopathological investigations demonstrated dural regeneration. CONCLUSIONS: Following dural reconstructions with TissuDura without surgical sutures, no local toxicity or complications were observed for up to 1 year. TissuDura demonstrated elasticity, non-reactivity, and good adaptability. The overlay technique using fibrin glue was simple and fast. Future studies and longer follow-up are needed to confirm the efficacy of TissuDura.

Immunohistochemical profile of neurotrophins in human cranial dura mater and meningiomas.

The immunohistochemical profile of neurotrophins and their receptors in the human cranial dura mater was studied by examining certain dural zones in specimens harvested from different regions (frontal, temporal, parietal and occipital). Dural specimens were obtained during neurosurgical operations performed in ten patients for surgical treatment of intracranial lesions (meningiomas, traumas, gliomas, vascular malformations). The dural fragments were taken from the area of the craniotomy at least 8 cm from the lesion as well as from the area in which the meningioma had its dural attachment. Immunohistochemical characterization and distribution of neurotrophins, with their receptors, were analyzed. The concrete role played by these neurotrophic factors in general regulation, vascular permeability, algic responsivity and release of locally active substances in the human dura mater is still controversial. Our study revealed a general structural alteration of dural tissue due to the invasivity of meningiomatous lesions, together with an improved expression of brain derived neurotrophic factor (BDNF) in highly proliferating neoplastic cells and an evident production of nerve growth factor (NGF) in inflammatory cells, suggesting that BDNF has a role in supporting the proliferation rate of neoplastic cells, while NGF is involved in the activation of a chronic inflammatory response in neoplastic areas.