Does breast cancer policy meet the needs of Aboriginal and Torres Strait Islander women in Australia? a review.

OBJECTIVE: To evaluate if existing Australian public policy related to screening, diagnosis, treatment and follow up care for breast cancer addresses the needs of and outcomes for Indigenous1 women? METHODS: This review of policy employed a modified Delphi method via an online panel of experts (n = 13), who were purposively recruited according to experience and expertise. A series of online meetings and online surveys were used for data collection. The aims of the study were to: Identify all existing and current breast cancer policy in Australia;  Analyse the extent to which consideration of Indigenous peoples is included in the development, design and implementation of the policy; and Identify policy gaps and make recommendations as to how they could be addressed. The policies were evaluated using 'A Guide to Evaluation under the Indigenous Evaluation Strategy, 2020'. RESULTS: A list of current breast cancer policies (n = 7) was agreed and analysed. Five draft recommendations to improve breast cancer outcomes for Indigenous women were developed and refined by the panel. CONCLUSIONS: Current breast cancer policy in Australia does not address the needs of Indigenous women and requires change to improve outcomes.

"Everyone needs a Deb": what Australian indigenous women say about breast cancer screening and treatment services.

BACKGROUND: Breast cancer continues to be the second most diagnosed cancer overall and the most diagnosed cancer for women in Australia. While mortality rates overall have declined in recent years, Indigenous women continue to be diagnosed at more marginal rates (0.9 times) and are more likely to die (1.2 times). The literature provides a myriad of reasons for this; however, the voices of Indigenous women are largely absent. This study sets out to understand what is happening from the perspectives of Australian Indigenous women with a view to charting culturally safer pathways that improve participation in screening and treatment by Indigenous women. METHODS: This co-design study was conducted using semi-structured, in-depth interviews and focus group discussions. Recruitment of study participants was via snowball sampling. Participants were subsequently consented into the study through the Aboriginal Health Service and the research team. Interviews were audio recorded and transcribed verbatim, and data coded in NVivo12 using inductive thematic analysis. RESULTS: A total of 21 Indigenous women and 14 health service providers were interviewed predominantly from the same regional/rural area in NSW, with a small proportion from other states in Australia. Six major themes were identified: Access, Awareness, Community and Family, Lack of control, Negative feelings and associations and Role of services. CONCLUSION: To improve access and participation of Indigenous women and ultimately improve mortality rates, breast cancer services must explicitly address cultural and community needs.

Laryngopharyngeal reflux induced sleep-related laryngospasm.

BACKGROUND: Sleep-related laryngospasm (SRL) has been defined as the sustained closure of the vocal cords during sleep. Studies have suggested that it is a rare manifestation of laryngopharyngeal reflux (LPR). Difficulties in diagnosing SRL and LPR have led to the condition being under-recognised in the clinical setting. AIMS: The aim of this study was to determine if LPR was the cause of the SRL symptoms seen in our patients. METHODS: A retrospective chart assessment of patients with SRL. Patients with risk factors for LPR were identified. These included smoking status, alcohol intake, a history of dyspepsia or history of gastroesophageal reflux disease, a history of late-night eating and a history of eating spicy or fatty foods before bed. A clinical diagnosis based on the history and response to management was made for the diagnosis of LPR. All were advised to refrain from late meals and those with signs of nasopharyngitis were commenced on proton pump inhibitor therapy. RESULTS: Nineteen patients (mean age ± SD: 57.21 ± 15.18) were included in the study. All had at least one risk factor for LPR. Ten (52.6%) had signs of nasopharyngitis on nasendoscopy. Following treatment, 17 (89.5%) reported no further SRL symptoms at 1-year follow-up. CONCLUSION: SRL is a largely unknown and under-diagnosed condition. We believe this study provides supportive evidence for the causal relationship between LPR and SRL.

Comparison of royal college of pathologists and college of american pathologists definition for positive margins in oral cavity squamous cell carcinoma.

BACKGROUND: Pathological margin assessment is an essential component of surgical management of oral cavity squamous cell carcinoma (OCSCC), however, in many studies, variable definitions of involved margins have been used. The purpose of the present study was to compare the prognostic ability of involved margins according to Royal College of Pathologists (RCPath) and College of American Pathologists (CAP) guidance. METHODS: Retrospective study of 300 patients with previously untreated OCSCC undergoing definitive surgical management. Main specimen margin status was defined according to RCPath guidance and CAP guidance. "Final margin status", incorporated the results of frozen sections and extra tumour bed resections. The prognostic impact of each margin definition was studied using univariate analysis, and in multivariate models including T-stage (AJCC 8th edition), nodal status (pN+), extranodal extension (ENE), and use of adjuvant radiotherapy. RESULTS: Both RCPath and CAP positive margins were associated with local recurrence (LR), disease-specific survival (DSS), and overall survival (OS) on univariate analysis, while final margin status was associated with LR and DSS, but not OS. On multivariate analysis, only CAP positive main specimen margin status was independently associated with LR (odds ratio 2.44, 95% CI 1.37, 4.34), DSS (odds ratio 2.28, 95% CI 1.31, 3.82), and OS (odds ratio 1.59, 95% CI 1.04, 2.42). CONCLUSIONS: Involved main specimen margin as defined by CAP guidance has the advantage of being an independent prognosticator of LR and survival in our cohort.

Astrocyte Control of Zika Infection Is Independent of Interferon Type I and Type III Expression.

Zika virus (ZIKV) is a pathogenic neurotropic virus that infects the central nervous system (CNS) and results in various neurological complications. Astrocytes are the dominant CNS cell producer of the antiviral cytokine IFN-ß, however little is known about the factors involved in their ability to mediate viral infection control. Recent studies have displayed differential responses in astrocytes to ZIKV infection, and this study sought to elucidate astrocyte cell-specific responses to ZIKV using a variety of cell models infected with either the African (MR766) or Asian (PRVABC59) ZIKV strains. Expression levels of pro-inflammatory (TNF-α and IL-1ß) and inflammatory (IL-8) cytokines following viral infection were low and mostly comparable within the ZIKV-resistant and ZIKV-susceptible astrocyte models, with better control of proinflammatory cytokines displayed in resistant astrocyte cells, synchronising with the viral infection level at specific timepoints. Astrocyte cell lines displaying ZIKV-resistance also demonstrated early upregulation of multiple antiviral genes compared with susceptible astrocytes. Interestingly, pre-stimulation of ZIKV-susceptible astrocytes with either poly(I:C) or poly(dA:dT) showed efficient protection against ZIKV compared with pre-stimulation with either recombinant IFN-ß or IFN-λ, perhaps indicating that a more diverse antiviral gene expression is necessary for astrocyte control of ZIKV, and this is driven in part through interferon-independent mechanisms.

Prognostic performance of TNM8 staging rules in oral cavity squamous cell carcinoma.

BACKGROUND: Two major changes to the staging of oral cavity squamous cell carcinoma (OCSCC) were adopted in TNM8: (1) depth of invasion is now used for T staging and (2) extranodal extension for N staging. The aim of this study was to evaluate if TNM8 stratifies OCSCC patients more accurately than TNM7 based on overall survival (OS) statistics and hazard discrimination. METHODS: Retrospective study of 297 patients with OCSCC who underwent surgery at our institution. Clinical and pathological data were previously populated from review of medical charts and histological reports. Slides were re-reviewed for depth of invasion measurements. Patients were staged using both TNM7 and TNM8 with overall survival statistics analysed. RESULTS: Overall 118 patients (39.7%) were upstaged using TNM8. Both TNM7 and TNM8 stage categories were highly significant for OS (all p values < 0.0001). Hazard discrimination analysis showed that TNM7 could only differentiate stage III from stage IV disease with significance (OS p = 0.01). In comparison TNM8 could distinguish between stage II and III disease (OS p = 0.047) and between stage III and IV disease (OS p = 0.004). Subsite analysis suggested that both editions of the staging system perform best for tongue primaries. CONCLUSIONS: Although TNM8 showed improved hazard discrimination in comparison to TNM7, problems with discriminative ability persisted with 8th edition staging criteria. Large scale validation studies will be required to direct future refinement of the staging rules and to establish if the continued use of a single staging system for all oral cavity subsites is appropriate.

Impact of 3 mm margin on risk of recurrence and survival in oral cancer.

INTRODUCTION: While positive surgical margins in oral squamous cell carcinoma (OSCC) is generally considered an adverse prognosticator, the significance of close (≤5 mm) margins is more debatable, and has not been widely adopted as an indicator for radiotherapy. MATERIALS AND METHODS: Retrospective study of 244 patients undergoing primary surgical resection of OSCC. The impact on local control (LC), disease-specific survival (DSS) and overall survival (OS) of margins at 1 mm intervals was studied. RESULTS: 65 patients had involved (<1 mm), 119 close (1-5 mm), and 60 clear (>5 mm) main specimen margins. Involved margins was predictive of DSS (p = 0.04), but not LC (p = 0.20) or OS (p = 0.09). Both the 2 mm and 3 mm margin cut-offs were significantly associated with LC (p = 0.02, and p = 0.01), DSS (p = 0.02, and p = 0.007), and OS (p = 0.03. and p = 0.005). In a 3-tier model, use of 3 mm for demarcation between close and clear yielded good separation between survival curves of clear (≥3 mm), and close (1-<3 mm) or involved (<1 mm). Final margins, determined after incorporation of frozen sections and extra margins taken separately, was significant for LC (p = 0.04), but not for DSS (p = 0.05) or OS (p = 0.17). On multivariate analysis, <3 mm margin, T-classification, nodal status, extranodal spread, and postoperative radiotherapy, were independent predictors of DSS and OS. For LC, only T-classification was significant. CONCLUSION: A 3 mm main specimen margin is significantly associated with survival in OSCC and may be useful for demarcation between close and clear. Further study is required to determine any impact on survival of radiotherapy for patients with <3 mm margins as sole indicator for radiotherapy.

Evolution of Cochlear implant mapping and vestibular function in a pediatric case of Labyrinthitis.

BACKGROUND: Vestibular symptoms such as vertigo and imbalance are known to occur in some cochlear implant patients during the immediate postoperative period; however, acute vertigo in implanted children occurring remotely from the postoperative period has not been previously well-described. CASE PRESENTATION: A three-year-old girl with a history of bilateral sequential cochlear implantation presented with acute labyrinthitis associated with sudden onset of vertigo, balance impairment, and decline in right cochlear implant function 2 years after her most recent implant surgery. We describe her audiological and vestibular testing results during both the acute phase and following medical management and recovery. CONCLUSION: Acute labyrinthitis should be considered when sudden onset vertigo and/or imbalance presents in children with cochlear implants outside of the perioperative period. Such symptoms should prompt early assessment of cochlear implant function, so that the device can be reprogrammed accordingly.

Mild Closed-Head Injury in Conscious Rats Causes Transient Neurobehavioral and Glial Disturbances: A Novel Experimental Model of Concussion.

Rodent models can provide insights into the most pertinent issues surrounding concussion. Nonetheless, the relevance of some existing models to clinical concussion can be questioned, particularly with regard to the use of surgery and anesthesia and the mechanism and severity of injury. Accordingly, we have co-developed an awake closed-head injury (ACHI) model in rats. Here, we aimed to create a temporal profile of the neurobehavioral and neuropathological effects of a single ACHI. Adolescent male rats were placed in a restraint bag and a steel helmet was positioned over the head such that the impact target was centered over the left parietal cortex. Once positioned on a foam platform, a cortical impactor was used to strike the helmet. Sham animals underwent the same procedure without impact. When compared with sham rats, those given a single ACHI displayed evidence of sensorimotor deficits and reduced exploratory behavior within the first 20 min post-injury; however, these effects were resolved after 24 h. A single ACHI impaired spatial memory on the Y-maze task at both 5 min and 24 h post-ACHI; however, no deficits were apparent at 48 h. Immunostaining revealed region-specific increases in ionized calcium-binding adaptor molecule 1 and glial fibrillary acidic protein expression at 3 days post-impact, with no differences found at either 1 or 14 days. Taken together, our findings indicate that a single ACHI results in transient neurobehavioral and glial disturbances and as such, this model may be a valuable tool for pre-clinical concussion research.

SOD1 Mutations Causing Familial Amyotrophic Lateral Sclerosis Induce Toxicity in Astrocytes: Evidence for Bystander Effects in a Continuum of Astrogliosis.

Astrocytes contribute to the death of motor neurons via non-cell autonomous mechanisms of injury in amyotrophic lateral sclerosis (ALS). Since mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1) underlie the neuropathology of some forms of familial ALS, we explored how expression of mutant SOD1 protein A4V SOD1-EGFP affected the biology of secondary murine astrocytes. A4V SOD1-EGFP expressing astrocytes (72 h after transfection) displayed decreased mitochondrial activity (~45%) and L-glutamate transport (~25%), relative to cells expressing wild-type SOD1-EGFP. A4V SOD1-EGFP altered F-actin and Hoechst staining, indicative of cytoskeletal and nuclear changes, and altered GM130 labelling suggesting fragmentation of Golgi apparatus. SOD1 inclusion formation shifted from discrete to "punctate" over 72 h with A4V SOD1-EGFP more rapidly producing inclusions than G85R SOD1-EGFP, and forming more punctate aggregates. A4V, not wild-type SOD1-EGFP, exerted a substantial, time-dependent effect on GFAP expression, and ~60% of astrocytes became stellate and hypertrophic at 72 h. Spreading toxicity was inferred since at 72 h ~80% of bystander cells exhibited hypertrophy and stellation. This evidence favours mutant SOD1-containing astrocytes releasing destructive species that alter the biology of adjacent astrocytes. This panoply of mutant SOD1-induced destructive events favours recruitment of astrocytes to non-cell autonomous injury in ALS.

Turbulent tackle: a novel surgical approach to a rugby-related jejunal perforation.

Viscus perforation in the context of blunt-force abdominal trauma is a rarity. Within a sporting context, it is especially rare. However, the increasing physicality observed in rugby union, both in the amateur and professional setting, has resulted in a higher rate of serious injury. We report a novel laparoscopic surgical approach to the management of a traumatic jejunal perforation sustained on the playing field in a previously fit and healthy 28-year-old.

Galactose-functionalised PCL nanofibre scaffolds to attenuate inflammatory action of astrocytes in vitro and in vivo.

Astrocytes represent an attractive therapeutic target for the treatment of traumatic brain injury in the glial scar, which inhibits functional repair and recovery if persistent. Many biomaterial systems have been investigated for neural tissue engineering applications, including electrospun nanofibres, which are a favourable biomaterial as they can mimic the fibrous architecture of the extracellular matrix, and are conveniently modified to present biologically relevant cues to aid in regeneration. Here, we synthesised a novel galactose-presenting polymer, poly(l-lysine)-lactobionic acid (PLL-LBA), for use in layer-by-layer (LbL) functionalisation of poly(ε-caprolactone) (PCL) nanofibres, to covalently attach galactose moieties to the nanofibre scaffold surface. We have assessed the use of this novel biomaterial system in vitro and in vivo, and have shown, for the first time, the ability of galactose to maintain an attenuated inflammatory profile of astrocytes in culture, and to increase the survival of neurons after traumatic injury, as compared to control PCL nanofibres. This study highlights the importance of galactose in controlling the astrocytic response, and provides a promising biomaterial system to deliver the essential morphological and biological cues to achieve functional repair after traumatic brain injury.

Impact of current smoking and alcohol consumption on gastrostomy duration in patients with head and neck cancer undergoing definitive chemoradiotherapy.

IMPORTANCE: Prophylactic gastrostomy tube (GT) insertion prior to chemoradiotherapy is a valuable nutritional adjunct in patients with head and neck cancer undergoing nonsurgical treatment. However, concerns have been expressed regarding high rates of GT dependence. There is little information in the literature regarding the impact of modifiable risk factors such as smoking and alcohol consumption on duration of GT use and dependence rates. OBJECTIVE: To study the duration of GT use in patients with head and neck cancer at our institution and to investigate risk factors for prolonged GT duration and dependence, including the impact of smoking and alcohol consumption. DESIGN, SETTING, AND PARTICIPANTS: This retrospective study at an academic teaching hospital included 104 patients with squamous cell carcinoma of the head and neck undergoing definitive treatment with either chemoradiotherapy (n = 84) or radiotherapy alone (n = 20). INTERVENTIONS: Prophylactic GT insertion prior to commencement of treatment. MAIN OUTCOMES AND MEASURES: Duration of GT use after completion of chemoradiotherapy or radiotherapy and the impact of risk factors on same. Duration of GT use was analyzed using Kaplan-Meier survival curves, with censoring of patients who developed cancer recurrence or died. RESULTS: The median duration of GT use was 9 months. The actuarial GT persistence rate at 1 year was 35%. Current smoking (hazard ratio [HR], 0.47; 95% CI, 0.27-0.81; P = .01) and current heavy alcohol consumption (HR, 0.55; 95% CI, 0.32-0.97; P = .04) were significant predictors of GT persistence. On multivariate analysis, only current smoking remained significant (HR, 0.53; 95% CI, 0.30-0.94; P = .03). Age 65 years or older, advanced T classification, larynx and/or hypopharynx primary site, and posttreatment neck dissection were not significant risk factors. CONCLUSIONS AND RELEVANCE: Current smoking and current heavy alcohol consumption are predictive of prolonged GT requirement in patients with head and neck cancer undergoing prophylactic GT insertion before definitive radiotherapy or chemoradiotherapy. Further study is required to investigate whether smoking or drinking cessation can reduce GT dependence rates in this population.

Transcriptomic analysis and 3D bioengineering of astrocytes indicate ROCK inhibition produces cytotrophic astrogliosis.

Astrocytes provide trophic, structural and metabolic support to neurons, and are considered genuine targets in regenerative neurobiology, as their phenotype arbitrates brain integrity during injury. Inhibitors of Rho kinase (ROCK) cause stellation of cultured 2D astrocytes, increased L-glutamate transport, augmented G-actin, and elevated expression of BDNF and anti-oxidant genes. Here we further explored the signposts of a cytotrophic, "healthy" phenotype by data-mining of our astrocytic transcriptome in the presence of Fasudil. Gene expression profiles of motor and autophagic cellular cascades and inflammatory/angiogenic responses were all inhibited, favoring adoption of an anti-migratory phenotype. Like ROCK inhibition, tissue engineered bioscaffolds can influence the extracellular matrix. We built upon our evidence that astrocytes maintained on 3D poly-ε-caprolactone (PCL) electrospun scaffolds adopt a cytotrophic phenotype similar to that produced by Fasudil. Using these procedures, employing mature 3D cultured astrocytes, Fasudil (100 µM) or Y27632 (30 µM) added for the last 72 h of culture altered arborization, which featured numerous additional minor processes as shown by GFAP and AHNAK immunolabelling. Both ROCK inhibitors decreased F-actin, but increased G-actin labeling, indicative of disassembly of actin stress fibers. ROCK inhibitors provide additional beneficial effects for bioengineered 3D astrocytes, including enlargement of the overall arbor. Potentially, the combined strategy of bio-compatible scaffolds with ROCK inhibition offers unique advantages for the management of glial scarring. Overall these data emphasize that manipulation of the astrocyte phenotype to achieve a "healthy biology" offers new hope for the management of inflammation in neuropathologies.

Combined excitotoxic-oxidative stress and the concept of non-cell autonomous pathology of ALS: insights into motoneuron axonopathy and astrogliosis.

Non-cell autonomous pathology is widely accepted to determine the demise of motoneurons (MNs) in amyotrophic lateral sclerosis (ALS) with astrocytes, GFAP and glutamate transport suggested to play roles in reactive astrogliosis. Previously we described actions of excitotoxicity and oxidative stress to produce differential injury of motoneurons and astrocytes, respectively, and our goal here was to define patterns of MN injury and astrogliosis during a combined excitotoxic-oxidative injury since such a paradigm more closely models disease pathology. Using an in vitro neuronal-glial culture of embryonic mouse spinal cord, we demonstrate that glutamate transport activity was maintained or increased initially, despite a loss of cellular viability, induced by exposure to combinations of excitotoxic [(S)-5-fluorowillardiine (FW)] and oxidative [3-morpholinosydnonimine (SIN-1)] insults over 48 h. Under these conditions, injury was slow in time course and apoptotic-like as shown by the patterns of annexin V and propidium iodide (PI) labelling. Immunocytochemistry for SMI-32 revealed that injury produced time- and insult-dependent reductions in the size of MN arbours, axonal dieback and appreciable neuritic blebbing. These changes were preceded by early hypertrophy of GFAP-positive astrocytes, and followed by more delayed stellation and eventual gliotoxicity. Alterations to EAAT2 immunolabelling were similar to those found for GFAP being initially maintained and then eventually reduced at 48 h. Image analysis of immunocytochemical data confirmed the differential time-dependent changes found with SMI-32, GFAP and EAAT2. Axonopathy and blebbing of MNs was frequently associated with areas of low GFAP immunoreactivity. The exact profile of changes to MNs and astrocytes was context-dependent and sensitive to subtle changes in the mix of excitotoxic-oxidative insults. Overall our findings are consistent with the concepts that the nature, extent and time-course of astrogliosis are insult-dependent, and that discrete pro-survival and destructive components of astrogliosis are likely to determine the precise profile of MN injury in non-cell autonomous pathology of ALS.

Transcriptomic profiling of astrocytes treated with the Rho kinase inhibitor fasudil reveals cytoskeletal and pro-survival responses.

Inhibitors of Rho kinase (ROCK) have potential for management of neurological disorders by inhibition of glial scarring. Since astrocytes play key roles in brain physiology and pathology, we determined changes in the astrocytic transcriptome produced by the ROCK inhibitor Fasudil to obtain mechanistic insights into its beneficial action during brain injury. Cultured murine astrocytes were treated with Fasudil (100 µM) and morphological analyses revealed rapid stellation by 1 h and time-dependent (2-24 h) dissipation of F-actin-labelled stress fibres. Microarray analyses were performed on RNA and the time-course of global gene profiling (2, 6, 12 and 24 h) provided a comprehensive description of transcriptomic changes. Hierarchical clustering of differentially expressed genes and analysis for over-represented gene ontology groups using the DAVID database focused attention on Fasudil-induced changes to major biological processes regulating cellular shape and motility (actin cytoskeleton, axon guidance, transforming growth factor-ß (TGFß) signalling and tight junctions). Bioinformatic analyses of transcriptomic changes revealed how these biological processes contributed to changes in astrocytic motility and cytoskeletal reorganisation. Here genes associated with extracellular matrix were also involved, but unexpected was a subset of alterations (EAAT2, BDNF, anti-oxidant species, metabolic and signalling genes) indicative of adoption by astrocytes of a pro-survival phenotype. Expression profiles of key changes with Fasudil and another ROCK inhibitor Y27632 were validated by real-time PCR. Although effects of ROCK inhibition have been considered to be primarily cytoskeletal via reduction of glial scarring, we demonstrate additional advantageous actions likely to contribute to their ameliorative actions in brain injury.

Transportable and non-transportable inhibitors of L-glutamate uptake produce astrocytic stellation and increase EAAT2 cell surface expression.

Astrocytic excitatory amino acid transporters (EAATs) regulate excitatory transmission and limit excitotoxicity. Evidence for a functional interface between EAATs and glial fibrillary acidic protein (GFAP) relevant to astrocytic morphology led to investigations of actions of transportable (D-Aspartate (D-Asp) and (2S,3S,4R)-2-(carboxycyclopropyl)glycine (L-CCG-III)) and non-transportable (DL-threo-beta-benzyloxyaspartate (DL-TBOA)) inhibitors of Glu uptake in murine astrocytes. D-Asp (1 mM), L-CCG-III (0.5 mM) and DL-TBOA (0.5 mM) produced time-dependent (24-72 h) reductions in (3)[H]D-Asp uptake (approximately 30-70%) with little or no gliotoxicity. All drugs induced a profound change in phenotype from cobblestone to stellate morphology and image analysis revealed increases in the intensity of GFAP immunolabelling for L-CCG-III and DL-TBOA. Cytochemistry indicated localized changes in F-actin distribution. Cell surface expression of EAAT2, but not EAAT1, was elevated at 72 h. Blockade of Glu uptake by both types of EAAT inhibitor exerts longer-term effects on astrocytic morphology and a compensatory homeostatic rise in EAAT2 abundance.

Evidence group I mGluR drugs modulate the activation profile of lipopolysaccharide-exposed microglia in culture.

Metabotropic glutamate receptors (mGluRs) may play a role in modulating microglial activation, but group I mGluRs have received little attention. This study aimed to investigate the effects of group I mGluR selective ligands, (S)-3,5-dihydroxyphenylglycine ((S)-3,5-DHPG) and (RS)-1-aminoindan-1,5-dicarboxylic acid (AIDA), in lipopolysaccharide (LPS; 50 ng/ml)-activated rat microglial cultures. (S)-3,5-DHPG (150 microM) significantly reduced (approximately 20-60%) the LPS-mediated production of nitrite (NO2(-)), tumour necrosis factor alpha (TNF-alpha), and L-glutamate (Glu) at 24 and 72 h. Image analysis revealed increases in both cell area and number, with larger amoeboid microglia (with retracted processes) formed following 2 h LPS exposure. This cellular population was absent after addition of (S)-3,5-DHPG, an effect antagonised by AIDA, and a concomitant reduction in cell area was also found. Taken together, these biochemical and morphological observations suggest that (S)-3,5-DHPG reduces microglial activation, indicating a role for group I mGluRs in modulating microglial function.

Oxidative and excitotoxic insults exert differential effects on spinal motoneurons and astrocytic glutamate transporters: Implications for the role of astrogliosis in amyotrophic lateral sclerosis.

In amyotrophic lateral sclerosis (ALS) non-neuronal cells play key roles in disease etiology and loss of motoneurons via noncell-autonomous mechanisms. Reactive astrogliosis and dysfunctional transporters for L-glutamate [excitatory amino acid transporters, (EAATs)] are hallmarks of ALS pathology. Here, we describe mechanistic insights into ALS pathology involving EAAT-associated homeostasis in response to a destructive milieu, in which oxidative stress and excitotoxicity induce respectively astrogliosis and motoneuron injury. Using an in vitro neuronal-glial culture of embryonic mouse spinal cord, we demonstrate that EAAT activity was maintained initially, despite a loss of cellular viability induced by exposure to oxidative [3-morpholinosydnonimine chloride (SIN-1)] and excitotoxic [(S)-5-fluorowillardiine (FW)] conditions. This homeostatic response of EAAT function involved no change in the cell surface expression of EAAT1/2 at 0.5-4 h, but rather alterations in kinetic properties. Over this time-frame, EAAT1/2 both became more widespread across astrocytic arbors in concert with increased expression of glial fibrillary acidic protein (GFAP), although at 8-24 h there was gliotoxicity, especially with SIN-1 rather than FW. An opposite picture was found for motoneurons where FW, not SIN-1, produced early and extensive neuritic shrinkage and blebbing (> or =0.5 h) with somata loss from 2 h. We postulate that EAATs play an early homeostatic and protective role in the pathologic milieu. Moreover, the differential profiles of injury produced by oxidative and excitotoxic insults identify two distinct phases of injury which parallel important aspects of the pathology of ALS.

The effects of estradiol on estrogen receptor and glutamate transporter expression in organotypic hippocampal cultures exposed to oxygen--glucose deprivation.

The molecular basis of estrogen-mediated neuroprotection against brain ischemia remains unclear. In the present study, we investigated changes in expression of estrogen receptors (ERs) alpha and beta and excitatory amino acid transporters (EAAT) 1 and 2 in rat organotypic hippocampal slice cultures treated with estradiol and subsequently exposed to oxygen--glucose deprivation (OGD). Pretreatment with 17beta-estradiol (10 nM) for 7 days protected the CA1 area of hippocampus against OGD (60 min), reducing cellular injury by 46% compared to the vehicle control group. Levels of ERalpha protein were significantly reduced by 20% after OGD in both vehicle- and estradiol-treated cultures, whereas ERbeta was significantly up-regulated by 25% in the estradiol-treated cultures. In contrast, EAAT1 and EAAT2 levels were unchanged in response to estradiol treatment in this model of OGD. These findings suggest that estrogen-induced neuroprotection against ischemia might involve regulation of ERbeta and, consequently, of the genes influenced by this receptor.