Glial Fibrillary Acidic Protein Staining Research Articles

Expression of peptidylarginine deiminase 4 in an alkali injury model of retinal gliosis

Citrullination is an important posttranslational modification that occurs during retinal gliosis. We examined the expression of peptidyl arginine deiminases (PADs) to identify the PADs that mediate citrullination in a model of alkali-induced retinal gliosis. Mouse corneas were exposed to 1.0 N NaOH and posterior eye tissue from injured and control uninjured eyes was evaluated for transcript levels of various PADs by reverse-transcription polymerase chain reaction (RT-PCR), and quantitative RT-PCR (qPCR). Retinas were also subjected to immunohistochemistry (IHC) for glial fibrillary acidic protein (GFAP), citrullinated species, PAD2, and PAD4 and tissue levels of GFAP, citrullinated species, and PAD4 were measured by western blots. In other experiments, the PAD4 inhibitor streptonigrin was injected intravitreally into injured eyes ex vivo to test inhibitory activity in an organ culture system. We found that uninjured retina and choroid expressed Pad2 and Pad4 transcripts. Pad4 transcript levels increased by day 7 post-injury (p < 0.05), whereas Pad2 levels did not change significantly (p > 0.05) by qPCR. By IHC, PAD2 was expressed in uninjured eyes along ganglion cell astrocytes, but in injured retina PAD2 was downregulated at 7 days. On the other hand, PAD4 showed increased staining in the retina upon injury revealing a pattern that overlapped with filamentous GFAP staining in Müller glial processes by 7 days. Injury-induced citrullination and soluble GFAP protein levels were reduced by PAD4 inhibition in western blot experiments of organ cultures. Together, our findings for the first time identify PAD4 as a novel injury-inducible druggable target for retinal gliosis.

Effects of quercetin on glial scar formation and axonal regeneration after acute spinal cord injury in rats and its association with p38 mitogen activated protein kinase signal pathway

Objective To investigate the effects of quercetin on glial scar formation and axonal regeneration after spinal cord injury (SCI) and its association with the p38 mitogen activated protein kinase (MAPK) signal pathway. Methods 128 female Sprague-Dawley (SD) rats were randomly divided into a control group (SCI + saline), an intervention group (SCI + quercetin + anisomycin), a treatment group (SCI + quercetin) and a sham-operation group (n=32). Basso Beattie Bresnahan (BBB) assessment and footprint analysis of the hind limb were performed on days 1, 3, 7, 14, 21 and 28 postoperation in each group. The expression levels of p38MAPK, phosphorylation p38MAPK, glial fibrillary acidic protein (GFAP) and neurofilament protein-200 (NF-200) were detected by Western blot. The numbers of GFAP and NF-200 positive staining cells in the injured spinal cord in each group were detected by immunohisto-chemistry. Results The BBB scores in the treatment group were significantly higher than in the inter-vention and control groups at each time point after SCI except on day 3 postoperation (P 0.05). The numbers of NF-200 and GFAP positive staining cells were significantly greater than in the sham-operation group at each time point postoperation (P< 0.05); the NF-200 positive staining cells in the treatment group were significantly increased in comparison with the control and intervention groups (P< 0.05); the GFAP positive staining cells in the treatment group were significantly fewer than in the control and intervention groups on days 7, 14 and 28 postoperation (P< 0.05). Conclusions Quercetin may have protective effects against acute SCI by decreasing glial scar formation, increasing axonal regeneration and promoting recovery of locomotor and nerve function in rats. The effects may be correlated with inhibition of the p38MAPK signal pathway. Key words: Spinal cord injury; Quercetin; Glial fibrillary acidic protein; neurofilament protein-200; p38 mitogen activated protein kinase

Gestational diabetes influences retinal Muller cells in rat's offspring.

Objective(s):The Muller cell is the principal glial cell of the vertebrate retina. The expression of Glial fibrillary acidic protein (GFAP) in the Muller cells was used as a cellular marker for retinal damage. This study was done to evaluate the effect of gestational diabetes on retinal Muller cells in rat’s offspring.Materials and Methods:In this experimental study, 12 Wistar rat dams were randomly allocated in control and diabetic groups. Gestational diabetes was induced by 40 mg/kg/body weight of streptozotocin at the first day of gestation, intraperitoneally. Dams in control group received an equivalent volume normal saline. Eye of six offspring of each group were removed at postnatal day 28 (P28). The histopathological changes in retina were examined through H&E staining and ultrastructure transmission electron microscopy (TEM). The expression of GFAP was examined using Immunohisto-chemical staining of GFAP in Muller cells. Photographs of retina were taken using Olympus BX51 microscope and a digital camera DP12 and EM LEO906; Zeiss, Germany.Results:In the control rat’s offspring, GFAP expression was not significant in Muller cells. According to the optical microscope images, GFAP expression was observed in the processes of the Muller cell in the inner plexiform layer of retina in offspring of diabetic mothers. In TEM technique, nuclear fragmentation and apoptotic bodies were observed in Muller cell of diabetic offspring.Conclusion:This study showed that the uncontrolled gestational diabetes can increase GFAP expression in Muller cells and retinal thickness of retinal layer in rat offspring’s, therefore uncontrolled gestational can damage the Muller cells.

Glycine Administration Alters MAPK Signaling Pathways and Causes Neuronal Damage in Rat Brain: Putative Mechanisms Involved in the Neurological Dysfunction in Nonketotic Hyperglycinemia.

High glycine (GLY) levels have been suggested to induce neurotoxic effects in the central nervous system of patients with nonketotic hyperglycinemia (NKH). Since the mechanisms involved in the neuropathophysiology of NKH are not totally established, we evaluated the effect of a single intracerebroventricular administration of GLY on the content of proteins involved in neuronal damage and inflammatory response, as well as on the phosphorylation of the MAPK p38, ERK1/2, and JNK in rat striatum and cerebral cortex. We also examined glial fibrillary acidic protein (GFAP) staining, a marker of glial reactivity. The parameters were analyzed 30min or 24h after GLY administration. GLY decreased Tau phosphorylation in striatum and cerebral cortex 30min and 24h after its administration. On the other hand, synaptophysin levels were decreased in striatum at 30min and in cerebral cortex at 24h after GLY injection. GLY also decreased the phosphorylation of p38, ERK1/2, and JNK 30min after its administration in both brain structures. Moreover, GLY-induced decrease of p38 phosphorylation in striatum was attenuated by N-methyl-D-aspartate receptor antagonist MK-801. In contrast, synuclein, NF-κB, iκB, inducible nitric oxide synthase and nitrotyrosine content, and GFAP immunostaining were not altered by GLY infusion. It may be presumed that the decreased phosphorylation of MAPK associated with alterations of markers of neuronal injury induced by GLY may contribute to the neurological dysfunction observed in NKH.

In Vitro Biocompatibility of Silicone Oil Siluron Xtra® on Porcine Retina in a Perfusion Culture System

Purpose: To examine the biocompatibility of Siluron Xtra® (Fluoron, Ulm, Germany), a silicone oil used as a vitreous substitute in vitreo-retinal surgery on porcine retinal tissue in vitro. Methods: Retinal tissue of 37 porcine eyes was immediately prepared post mortem and placed into Minucell perfusion systems (Minucell, Bad Abbach, Germany) to be perfused with liquid culture medium over a period of 4-8 days. 23 retinal tissue samples including retinal pigment epithelium (RPE) were covered by silicone oil (group 1) during the perfusion and compared to a control group of 7 samples (group 2) without silicone oil. Group 3 included 7 single RPE tissues without retinal tissue layer in direct contact with silicone oil, thus imitating a retinal tear, during the perfusion. The morphology of the retina and RPE was examined by light microscopy and stained with immunohistochemical markers to determine Muller cell damage in the retina with Glial fibrillary acidic protein (GFAP) and proliferation in the RPE with Ki67. Results: Ki67 staining showed significantly less proliferation in the tissue covered by silicone oil (group 1) compared to the control samples in group 2 (p=0.001). Direct contact of silicone oil and RPE (group 3) showed no significant increase in proliferation compared to the controls (p=1). GFAP staining also did not show any significant Muller cell damage related to Siluron Xtra® (p=0.9). No structural changes in the retinal tissue were observed related to silicone oil by HE staining. Conclusion: The results of our in vitro examination verified good structural biocompatibility of silicone oil (Siluron Xtra®) on porcine retina and RPE in vitro. Furthermore, silicone oil may exert a protective layer preventing proliferation on retinal tissue. Further examination of other silicone oils and alternative vitreous substitutes, such as gas and water are necessary to determine the protective advantage of Siluron Xtra® on retinal tissue proliferation.

Brain Diffusivity and Structural Changes in the R6/2 Mouse Model of Huntington Disease.

Diffusion-weighted magnetic resonance (DW-MR) is an important diagnostic tool in Huntington disease (HD), a fatal hereditary neurodegenerative disorder. To clarify the nature of diffusivity changes in HD, we compared the apparent diffusion coefficient of water (ADCW ) acquired by DW-MR with extracellular space volume fraction α and tortuosity λ, measured by the iontophoretic method in the R6/2 mouse model of HD and in wild-type controls (WT). In anisotropic globus pallidus (GP), diffusion measurements were performed in the mediolateral (x), rostrocaudal (y), and ventrodorsal (z) axes. In HD animals, we detected an increase in ADCW in all axes and larger α than in WT mice. No significant difference between WT and HD mice was found in the values of tortuosity (λx , λy , λz ). Despite structural changes in GP, diffusion anisotropy was unaffected in HD mice. Immunohistochemical analysis revealed in HD mice weaker expression of extracellular matrix and a decrease in neuron numbers compared with WT mice. Glial fibrillary acidic protein staining detected astrogliosis-like changes in the morphology of astrocytic processes in HD GP. In the somatosensory cortex, no significant differences in the studied parameters were found. We conclude that in the R6/2 model of HD, a decrease in the number of neurons in the GP results in increased ADCW and α values. Values of λ were not significantly changed as the increase of diffusion obstacles formed by reactive astrocytes was compensated for by the extracellular matrix reduction. © 2016 Wiley Periodicals, Inc.

Effects of renal sympathetic denervation on the stellate ganglion and brain stem in dogs

Renal sympathetic denervation (RD) is a promising method of neuromodulation for the management of cardiac arrhythmia. We tested the hypothesis that RD is antiarrhythmic in ambulatory dogs because it reduces the stellate ganglion nerve activity (SGNA) by remodeling the stellate ganglion (SG) and brain stem. We implanted a radiotransmitter to record SGNA and electrocardiogram in 9 ambulatory dogs for 2 weeks, followed by a second surgery for RD and 2 months SGNA recording. Cell death was probed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Integrated SGNA at baseline and 1 and 2 months after RD were 14.0 ± 4.0, 9.3 ± 2.8, and 9.6 ± 2.0 μV, respectively (P = .042). The SG from RD but not normal control dogs (n = 5) showed confluent damage. An average of 41% ± 10% and 40% ± 16% of ganglion cells in the left and right SG, respectively, were TUNEL positive in RD dogs compared with 0% in controls dogs (P = .005 for both). The left and right SG from RD dogs had more tyrosine hydroxylase-negative ganglion cells than did the left SG of control dogs (P = .028 and P = .047, respectively). Extensive TUNEL-positive neurons and glial cells were also noted in the medulla, associated with strongly positive glial fibrillary acidic protein staining. The distribution was heterogeneous, with more cell death in the medial than lateral aspects of the medulla. Bilateral RD caused significant central and peripheral sympathetic nerve remodeling and reduced SGNA in ambulatory dogs. These findings may in part explain the antiarrhythmic effects of RD.

Hollow manganese oxide nanoparticle-enhanced MRI of hypoxic-ischaemic brain injury in the neonatal rat.

To determine the utility of hollow manganese oxide nanoparticle (HMON)-enhanced MRI in depicting and monitoring apoptotic area following hypoxic-ischaemic injury in a neonatal rat brain and to evaluate the longitudinal evolution of hypoxic-ischaemic brain injury (HII) up to 21 days. The institutional animal care and use committee approval was obtained. The Rice-Vannucci model of HII was used in 7-day-old rat pups (n = 17). MRI was performed 1, 3, 7, 14 and 21 days after HII with intraperitoneal injection of HMON. Relative contrast values in the injured hemisphere and mean apparent diffusion coefficient values were calculated at each time point. Apoptosis and reactive astrogliosis were detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labelling (TUNEL) and glial fibrillary acidic protein staining, and the distribution and intensity of immunohistochemical staining were directly compared with those of HMON enhancement on MRI. The dorsolateral thalamus, hippocampus and remaining cortex of the injured hemisphere showed HMON enhancement from 3 to 21 days after HII. The mean relative contrast values in the dorsolateral thalamus showed an increase from a negative value at 1 day to 16.5 ± 4.8% at 21 days. The apoptotic cells and reactive astrocytes were observed on immunohistochemical staining from 1 to 21 days after HII. The accumulation of apoptotic cells regionally matched with the areas of HMON enhancement, while that of reactive astrocytes did not. The areas of HMON enhancement showed best spatial agreement with those of apoptosis on TUNEL staining. Both HMON enhancement and TUNEL-positive cells were observed up to 21 days after HII. Advances in knowledge: The strength of our study is the visualization of apoptotic area in vivo using HMON-enhanced MRI, and we also showed that HII has a prolonged evolution lasting for several weeks.

Early and Persistent Dendritic Hypertrophy in the Basolateral Amygdala following Experimental Diffuse Traumatic Brain Injury.

In the pathophysiology of traumatic brain injury (TBI), the amygdala remains understudied, despite involvement in processing emotional and stressful stimuli associated with anxiety disorders, such as post-traumatic stress disorder (PTSD). Because the basolateral amygdala (BLA) integrates inputs from sensory and other limbic structures coordinating emotional learning and memory, injury-induced changes in circuitry may contribute to psychiatric sequelae of TBI. This study quantified temporal changes in dendritic complexity of BLA neurons after experimental diffuse TBI, modeled by midline fluid percussion injury. At post-injury days (PIDs) 1, 7, and 28, brain tissue from sham and brain-injured adult, male rats was processed for Golgi, glial fibrillary acidic protein (GFAP), or silver stain and analyzed to quantify BLA dendritic branch intersections, activated astrocytes, and regional neuropathology, respectively. Compared to sham, brain-injured rats at all PIDs showed enhanced dendritic branch intersections in both pyramidal and stellate BLA neuronal types, as evidenced by Sholl analysis. GFAP staining in the BLA was significantly increased at PID1 and 7 in comparison to sham. However, the BLA was relatively spared from neuropathology, demonstrated by an absence of argyrophilic accumulation over time, in contrast to other brain regions. These data suggest an early and persistent enhancement of dendritic complexity within the BLA after a single diffuse TBI. Increased dendritic complexity would alter information processing into and through the amygdala, contributing to emotional symptoms post-TBI, including PTSD.

Clinical characters and treatments of retinal vasoproliferative tumors

Retinal vasoproliferative tumors (VPT) are uncommon benign vascular tumors. They mostly occur in healthy patients, but may be associated with other chorioretinal diseases. Here we report four patients with VPT at a referral center from 2006 to 2015. Three patients denied any past history and one had a history of retinal detachment surgery. VPT-related complications included epiretinal membrane (ERM) (n=2), cystoids macular edema (n=1), and lamellar hole combined with dense cataract, rigid anterior capsule and vitreous opacity (n=1). Treatments for VPT and comorbidities included vitrectomy (VT) and membrane peeling with tumor resection (n=2), a combined treatment of photodynamic therapy (PDT) and intravitreal injection (IVI) of anti-vascular endothelial growth factor (anti-VEGF) (n=2). Tumor shrinkage was achieved in both patients treated with PDT and IVI of anti-VEGF injection. The other two patients with ERM were successfully treated with VT and tumor resection. Visual acuity improved at least two lines in three patients, and one patient had decreased vision due to cataract formation after VT. Pathology of the resected tumor in one case revealed massive gliosis with positive stain of vascular endothelial cells and glial fibrillary acidic protein stain. Yet the peeled membrane was acellular. Possible beneficial treatments for VPT and comorbidities include PDT combined with IVI of anti-VEGF, or VT and membrane peeling with tumor resection.

Identification and localization of lamina cribrosa cells in the human optic nerve head

One of the central features of glaucoma is progressive cupping and excavation of the optic nerve head (ONH). Unmyelinated retinal ganglion cell (RGC) axons exit the eye through the ONH, which is supported by the lamina cribrosa (LC) consisting of plates of connective tissue with channels for bundles of RGC axons. The LC progressively remodels during glaucoma, but the cellular and molecular mechanisms responsible for this remodeling are poorly understood. Two major cell types have been isolated and cultured from the human ONH, which differ in their characteristics. Glial fibrillary acidic protein (GFAP) positive ONH astrocytes are the major cell type and are reactive in glaucoma. GFAP negative LC cells are the second major cell type isolated from the human ONH, and in contrast to ONH astrocytes, are α-smooth muscle actin (α-SMA) positive. Although a number of in vitro studies have been conducted with LC cells, to date there has been no direct evidence for these cells in situ in the human ONH. We used GFAP and α-SMA immunofluorescent staining of human eyes to clearly demonstrate the presence of not only ONH astrocytes within the human ONH, but also LC cells within the cribriform (e.g. laminar) plates/beams of the LC region. Both of these cell types likely play important roles in the homeostatic maintenance of the ONH and pathogenic changes that occur in primary open angle glaucoma (POAG).

Reduction of Astrocyte and Microglial Activation in Insulin/Saline‐treated Diabetic Ketoacidosis by the KCa3.1 Blocker TRAM‐34

Previous studies have provided evidence that diabetic ketoacidosis (DKA) and/or its treatment with insulin and saline (I/S) causes brain injury in children. However, mechanisms underlying DKA‐related brain injury have been poorly understood. In recent studies using immunohistochemistry (IHC) in a streptozotocin (STZ)‐induced DKA juvenile rat model, we examined expression of glial fibrillary acidic protein (GFAP) and CD‐11b protein (OX42) in hippocampus, cortex and striatum at 4, 24 and 72 hr after I/S treatment. We found increased GFAP in hippocampus as well as increased OX42 in both hippocampus and cortex, suggesting that reactive gliosis and microglial activation occur during DKA‐related brain injury. Other studies have shown that TRAM‐34, a KCa3.1 channel blocker, reduces microglial activation in the rat middle cerebral artery occlusion model of cerebral ischemia. The present study was conducted to determine whether TRAM‐34 could also reduce DKA‐related inflammatory changes in the brain. We used IHC to investigate the effects of TRAM‐34 on GFAP and OX‐42 expression in brain sections from juvenile rats with STZ‐induced DKA before, during and after treatment with insulin and saline. As in previous studies, OX42 staining intensity was increased in the hippocampus and cortex during DKA and increased further 4 hours after I/S treatment in a manner sustained through 24 and 72 hours after recovery from DKA. GFAP staining intensity was also increased over the same time course in hippocampus but not cortex. However, in rats administered TRAM‐34 (IP, 40 mg/kg) at the start of I/S treatment, staining intensities of both OX42 and GFAP were significantly reduced at all time points after DKA. OX42 staining intensity was also decreased during DKA prior to I/S treatment in TRAM‐34 treated rats. We conclude that DKA causes inflammatory changes in the brain including reactive gliosis and activation of microglia. Treatment with TRAM‐34 not only decreases microglial activation but also reduces reactive gliosis, suggesting an overall decrease in the brain's inflammatory response to DKA.Support or Funding InformationSupported by ADA

Expression and effect of proline hydroxylase domain 2 in retina of diabetic rats.

To observe the expression of proline hydroxylase domain 2 (PHD2) in the retina of diabetic rats and investigate the relationship between PHD2 and relevant intraocular vascular proliferation factors. Sixty male specific pathogen free (SPF) Sprague-Dawley (SD) rats were randomly divided into two groups: the diabetic group and the control group. The rats in the diabetic group were intraperitoneally injected with 60 mg/kg (0.60 mL/100g) of streptozotocin to induce a diabetic rat model. The rats in the control group were injected with an equal volume of sodium citrate buffer solution by the same method. Hematoxylin-eosin (HE) staining and immumofluorescence (IF) method were adopted to observe the pathological changes of retinal tissues and the expression of PHD2, glial fibrillary acidic protein (GFAP), vascular endothelial growth factor (VEGF) by 8wk. RT-PCR method was applied to detect the expressions of mRNA of PHD2, VEGF and GFAP. The relationship between PHD2 and other vascular proliferation factors was analyzed. HE staining showed that there was the retinal tissue edema in the diabetic group, and the arrangement was in disorder, and proliferation could be seen. IF staining: in the retina of normal rats, PHD2 was not expressed, GFAP and VEGF were mainly expressed in astrocytes; while in the diabetic rats, PHD2, GFAP and VEGF staining showed strong positivity in all retinal layers, mainly in neurogliocytes. PHD2 was co-expressed with VEGF and GFAP. The mRNA expression levels of PHD2, GFAP and VEGF in the diabetic group were obviously higher than that in the control group,respectively 1.83 times, 1.75 times and 2.08 times. The difference had statistical significance (P<0.01). The high expression of PHD2 in the retina of early-stage diabetic rats might result from secretion of neurogliocytes induced by local high-concentration blood glucose, thus promoting the expression of VEGF and GFAP. PHD2 plays an important role during the occurrence of diabetic retinopathy.

Hyaluronic acid scaffold has a neuroprotective effect in hemisection spinal cord injury.

OBJECTIVE Spinal cord injury occurs in 2 phases. The initial trauma is followed by inflammation that leads to fibrous scar tissue, glial scarring, and cavity formation. Scarring causes further axon death around and above the injury. A reduction in secondary injury could lead to functional improvement. In this study, hyaluronic acid (HA) hydrogels were implanted into the gap formed in the hemisected spinal cord of Sprague-Dawley rats in an attempt to attenuate damage and regenerate tissue. METHODS A T-10 hemisection spinal cord injury was created in adult male Sprague-Dawley rats; the rats were assigned to a sham, control (phosphate-buffered saline), or HA hydrogel-treated group. One cohort of 23 animals was followed for 12 weeks and underwent weekly behavioral assessments. At 12 weeks, retrograde tracing was performed by injecting Fluoro-Gold in the left L-2 gray matter. At 14 weeks, the animals were killed. The volume of the lesion and the number of cells labeled from retrograde tracing were calculated. Animals in a separate cohort were killed at 8 or 16 weeks and perfused for immunohistochemical analysis and transmission electron microscopy. Samples were stained using H & E, neurofilament stain (neurons and axons), silver stain (disrupted axons), glial fibrillary acidic protein stain (astrocytes), and Iba1 stain (mononuclear cells). RESULTS The lesions were significantly smaller in size and there were more retrograde-labeled cells in the red nuclei of the HA hydrogel-treated rats than in those of the controls; however, the behavioral assessments revealed no differences between the groups. The immunohistochemical analyses revealed decreased fibrous scarring and increased retention of organized intact axonal tissue in the HA hydrogel-treated group. There was a decreased presence of inflammatory cells in the HA hydrogel-treated group. No axonal or neuronal regeneration was observed. CONCLUSIONS The results of these experiments show that HA hydrogel had a neuroprotective effect on the spinal cord by decreasing the magnitude of secondary injury after a lacerating spinal cord injury. Although regeneration and behavioral improvement were not observed, the reduction in disorganized scar tissue and the retention of neurons near and above the lesion are important for future regenerative efforts. In addition, this gel would be useful as the base substrate in the development of a more complex scaffold.

The possible protective effect of curcumin on monosodium glutamate-induced retinal changes in adult male albino rats

Introduction Monosodium glutamate (MSG) is widely used as a flavor-enhancing food additive for its unique taste. It is added to fast foods, children’s foods, snacks, soups, and many other canned foods all over the world. Recently, it has been proved that MSG has neurotoxic effects, including retinal degeneration. Curcumin is a naturally occurring compound with known antioxidative activity. Experimentally, it has been observed that curcumin has a significant retinal neuroprotective effect. Aim The present study was carried out to investigate the possible protective effect of curcumin against the retinal toxicity of MSG. Materials and methods Thirty adult male albino rats were used. The animals were divided as follows: group I was the control group; group II received curcumin at a dose of 150 mg/kg body weight; group III received MSG at a dose of 1 g/kg body weight; and group IV received MSG concomitantly with curcumin at the same previous doses. Both curcumin and MSG were given orally once daily for 4 weeks. Retinal sections were stained with H&E and immunohistochemically stained to detect glial fibrillary acidic protein (GFAP) and caspase-3 antibodies. Retinal thickness and area% of GFAP staining were measured. Results MSG caused several histological retinal changes, including separation of pigment epithelium, distortion and disorganization of photoreceptors, pyknosis in many nuclei of the outer nuclear layer, degeneration in the cells of the inner nuclear layer and the ganglion cell layer, dilatation and congestion of some blood vessels, and interruption of the internal limiting membrane. A statistically significant decrease in the retinal thickness and increase in area% reaction with GFAP antibodies were also detected. Such abnormalities were, to a large extent, prevented with the use of curcumin. Conclusion Several histological alterations were observed in the retinas of rats treated with MSG, and coadministration of curcumin with MSG improved these alterations to a large extent.

Schwannoma microquístico reticular: reporte de 2 casos

Reticular microcystic schwannoma (RMS) is a rare variant of schwannoma found most frequently in the gastrointestinal tract; it is a benign neural neoplasm with a low rate of recurrence. Microscopically, it shows a striking microcystic and reticular lesional growth pattern with anastomosing and interlacing strands of spindle cells around islands of myxoid or collagenous/hyalinized stroma. Mitotic activity is low and both atypia and necrosis are absent.Immunohistochemically, there is a strong nuclear and cytoplasmic positivity for S-100 and a variably strong glial fibrillary acidic protein staining (GFAP).Differential diagnoses include gastrointestinal stromal tumour, perineurioma and, in cases with epithelioid morphology, epithelial neoplasms should be considered.There are few reported cases to date. We present 2 cases, one in small bowel and the other in mesoappendix.

Characterization of the blood brain barrier in pediatric central nervous system neoplasms.

ObjectiveThe normal blood–brain barrier (BBB) is composed of tight junctions between endothelial cells and surrounding astrocyte foot processes. Breakdown of the physiological astrocyte-endothelial cell relationship occurs in adult metastatic and primary brain tumors. However, the astrocyte-endothelial cell relationship has not been studied in pediatric tumors.Materials and MethodsUtilizing specimens from cases of pilocytic astrocytoma (n = 5), medulloblastoma (n = 5), and low-grade diffuse astrocytoma (n = 1), immunofluorescence were performed using primary antibodies against CD31, glial fibrillary acidic protein (GFAP), and aquaporin 4 (AQ4). Clinical, magnetic resonance imaging, operative, and histopathological findings were analyzed.ResultsStrongly-enhancing areas of medulloblastoma exhibited complete BBB breakdown with sparse GFAP and AQ4 staining around CD31-positive vessels. Moderately enhancing regions of pilocytic astrocytomas exhibited regions of intact BBB and vasculature surrounded by dense GFAP staining but reduced and disorganized AQ4 staining, suggesting tumor cells could not fulfill physiological BBB support. Non-enhancing low-grade diffuse astrocytoma demonstrated intact BBB with intense peri-microvasculature GFAP and AQ4 staining. AQ4 stained so strongly that AQ4 visualization alone delineated CD31-positive vessels.ConclusionTaken together, BBB breakdown in pediatric tumors corresponds to a loss of normal endothelial cell-astrocyte foot process relationships. Further development of pharmaceutical agents capitalizing on this disrupted BBB is warranted in medulloblastoma and pilocytic astrocytoma. However, BBB integrity remains a challenge in treating low-grade diffuse astrocytoma before progression toward secondary glioblastoma.

Evaluation of the Combination of Methylprednisolone and Tranilast after Spinal Cord Injury in Rat Models.

ObjectiveThe aim of our study was to evaluate the neuroprotective functions of the combination therapy using methylprednisolone (MP) and tranilast (TR) after spinal cord injury (SCI) in adult rats.MethodsSpinal cord compression injury model was achieved using Yasargil aneurysm clip. Rats were divided into control group, MP group, TR group, and combination therapy group using TR and MP. Rat models were assessed for locomotor functional recovery using Basso, Beattie, and Bresnahan (BBB) score, spinal cord water content and myeloperoxidase (MPO) activity 24 hours post SCI, haematoxylin and eosin staining and glial fibrillary acid protein (GFAP) staining at 7 and 14 days post SCI.ResultsThe spinal cord water content and MPO activity in the combination therapy group was significantly lower than the control group and the individual therapy groups p<0.05. The combination therapy group had significantly higher BBB scores than control group and individual therapy groups (p<0.05). At one week after SCI, GFAP expression in the combination group was significantly lower than the control group (p<0.05) but there was no significant difference compared to the individual therapy groups (p>0.05). At 2 weeks after SCI there was a slight decrease in GFAP expression compared to the first week but the difference was not statistically significant (p>0.05), GFAP expression between the groups was not statistically significant p>0.05.ConclusionCombining MP and TR is therapeutically more effective in improving functional recovery, inhibiting inflammation and glial scar formation after acute SCI.

Yokukansan, a Kampo medicine, prevents the development of morphine tolerance through the inhibition of spinal glial cell activation in rats

BackgroundAnimal models have shown that glial cells (microglia and astrocytes) in the spinal cord undergo activation following peripheral injury associated with chronic pain, suggesting the involvement of these cells in pain diseases. We have previously reported that Yokukansan (YKS), a Japanese traditional herbal (Kampo) medicine, is effective against chronic pain through the suppression of spinal glial cell activation. Morphine is a widely-used opioid analgesic for relieving severe pain, but its repeated administration leads to the development of antinociceptive tolerance. The development of morphine tolerance is also reported to be caused by spinal glial cells activation. In the present study, we investigated the inhibitory effects of YKS on the development of morphine tolerance and the activation of the spinal microglia and astrocytes using a rat model. MethodsMale Wistar rats received a subcutaneous injection of morphine hydrochloride (10mg/kg/d) for 7 days, and the withdrawal latency to thermal stimulation was measured daily using a hot plate test. Thereafter, the appearance of activated microglia and astrocyte in the spinal cord (L5) was examined by immunofluorescence staining. Ionized calcium binding adapter molecule-1 (Iba-1) staining was used to label microglia and glial fibrillary acidic protein (GFAP) staining was performed to label astrocytes. YKS was administered mixed with powdered rodent chow at a concentration of 3%. ResultsThe preadministration of YKS (started 3 d before the morphine injection) prevented the development of morphine tolerance. The repeated administration of morphine increased Iba-1 and GFAP immune reactivities in the spinal cord; however, these activations were inhibited by the preadministration of YKS. ConclusionThese results suggest that the preadministration of YKS attenuates the development of antinociceptive morphine tolerance, and the suppression of spinal glial cell activation may be one mechanism underlying this phenomenon.

Radiologic evidence that hypothalamic gliosis is associated with obesity and insulin resistance in humans.

To use quantitative magnetic resonance imaging (MRI) to test whether mediobasal hypothalamic (MBH) gliosis is associated with obesity and insulin resistance in humans. Sixty-seven participants underwent a fasting blood draw and MRI. Cases with radiologic evidence of MBH gliosis (N = 22) were identified as the upper tertile of left MBH T2 relaxation time and were compared to controls (N = 23) from the lowest tertile. In a separate postmortem study, brain slices (N = 10) through the MBH were imaged by MRI and stained for glial fibrillary acidic protein (GFAP). In all participants, longer T2 relaxation time in the left MBH was associated with higher BMI (P = 0.01). Compared with controls, cases had longer T2 relaxation times in the right MBH (P < 0.05), as well as higher BMI (P < 0.05), fasting insulin concentrations (P < 0.01), and HOMA-IR values (P < 0.01), adjusted for sex and age. Elevations in insulin and HOMA-IR were also independent of BMI. In the postmortem study, GFAP staining intensity was positively associated with MBH T2 relaxation time (P < 0.05), validating an MRI-based method for the detection of MBH gliosis in humans. These findings link hypothalamic gliosis to insulin resistance in humans and suggest that the link is independent of the level of adiposity.