Plastic pollution in paradise: Daily accumulation rates of marine litter on Cousine Island, Seychelles.

The daily accumulation rates, composition, sizes and potential sources of marine litter collected on a remote island within the Western Indian Ocean were investigated. In total, 9119 items of marine litter were collected during 40 surveys, which equated to 0.0082 items·m-1·d-1. Between 2003 and 2019 there was a significant increase in the amount of litter deposited, with the highest daily accumulation rate recorded in 2019 (0.0255 items·m-1·year-1). All specific litter types increased over time and also differed significantly in their accumulation rates, with polystyrene fragments/pieces (0.00249 items·m-1·d-1), plastic items (0.00135 items·m-1·d-1) and plastic bottles (0.0011 items·m-1·d-1) being the most commonly encountered during this study. The majority of the litter found was ≤5 cm in size. Nearly all (>80%) litter collected was made of or contained some form of plastic. Recommendations for improved management of litter and the importance of establishing regular beach clean-ups within the Seychelles are briefly discussed.

An atmospheric pressure chemical ionisation liquid chromatographic-tandem mass spectrometry method for the analysis of benzodiazepines in urine.

The objective of this work was to establish an analytical method for the analysis of 7 Benzodiazepines (diazepam, oxazepam, temazepam, nordiazepam, desalkylflurazepam, alprazolam and α-hydroxyalprazolam) in urine specimens taken from drivers suspected of driving under the influence of drugs. The specimen, calibrator and control preparation involved hydrolysis of conjugated benzodiazepines using ß-glucuronidase in sodium acetate buffer, with incubation at 60°C for 2h. Specimens were then centrifuged, before being diluted 1 in 5 (total dilution 1 in 10), with 10% acetonitrile in water. Specimens were analysed using a Shimadzu Prominence UPLC coupled to an AB Sciex 4000 QTrap LC-MS-MS. The chromatographic column was a Shim-pack XR ODS 2.2µm. 3.0×50mm column and the mobile phase was a binary gradient system comprising of mobile phase A which was an ammonium formate/formic acid buffer dissolved in water and mobile phase B which was an ammonium formate/formic acid buffer dissolved in Acetonitrile. APCI was selected as the ionisation technique and the MS was operated in MRM mode, monitoring 2 transitions per analyte. The validation of the method is described. The method was found to be linear, accurate and precise (within day and between day) for diazepam, oxazepam, temazepam, nordiazepam, desalkylflurazepam, alprazolam and α-hydroxyalprazolam. The results of 480 cases are reviewed and show that alprazolam use was found in 35% of cases. Use of benzodiazepines resulting in oxazepam, nordiazepam or temazepam were found ca. 70% of cases analysed.

Achieving assessor accuracy on the International Standards for Neurological Classification of Spinal Cord Injury.

STUDY DESIGN: A retrospective audit of assessor accuracy using the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) in three multicentre randomised controlled trials (SCIPA: Spinal Cord Injury and Physical Activity) spanning 2010-2014 with standards revised in 2011. OBJECTIVES: To investigate assessor accuracy of neurological classification after spinal cord injury. SETTING: Australia and New Zealand. METHODS: ISNCSCI examinations were undertaken by trained clinicians prior to randomisation. Data were recorded manually and ISNCSCI worksheets circulated to panels, consensus reached and worksheets corrected. An audit team used a 2014 computerised ISNCSCI algorithm to check manual worksheets. A second audit team assessed whether the 2014 computerised algorithm accurately reflected pre- and post-2011 ISNCSCI standards. RESULTS: Of the 208 ISNCSCI worksheets, 24 were excluded. Of the remaining 184 worksheets, 47 (25.5%) were consistent with the 2014 computerised algorithm and 137 (74.5%) contained one or more errors. Errors were in motor (30.1%) or sensory (12.4%) levels, zone of partial preservation (24.0%), motor/sensory scoring (21.5%), ASIA Impairment Scale (AIS, 8.3%) and complete/incomplete classification (0.8%). Other difficulties included classification when anal contraction/sensation was omitted, incorrect neurological levels and violation of the 'motor follows sensory rule in non-testable myotomes' (7.4%). Panel errors comprised corrections that were incorrect or missed or incorrect changes to correct worksheets. CONCLUSION: Given inaccuracies in the manual ISNCSCI worksheets in this long-term clinical trial setting, continued training and a computerised algorithm are essential to ensure accurate scoring, scaling and classification of the ISNCSCI and confidence in clinical trials.

Quantifying the accretion of hyperphosphorylated tau in the locus coeruleus and dorsal raphe nucleus: the pathological building blocks of early Alzheimer's disease.

AIMS: Hyperphosphorylated tau neuronal cytoplasmic inclusions (ht-NCI) are the best protein correlate of clinical decline in Alzheimer's disease (AD). Qualitative evidence identifies ht-NCI accumulating in the isodendritic core before the entorhinal cortex. Here, we used unbiased stereology to quantify ht-NCI burden in the locus coeruleus (LC) and dorsal raphe nucleus (DRN), aiming to characterize the impact of AD pathology in these nuclei with a focus on early stages. METHODS: We utilized unbiased stereology in a sample of 48 well-characterized subjects enriched for controls and early AD stages. ht-NCI counts were estimated in 60-µm-thick sections immunostained for p-tau throughout LC and DRN. Data were integrated with unbiased estimates of LC and DRN neuronal population for a subset of cases. RESULTS: In Braak stage 0, 7.9% and 2.6% of neurons in LC and DRN, respectively, harbour ht-NCIs. Although the number of ht-NCI+ neurons significantly increased by about 1.9× between Braak stages 0 to I in LC (P = 0.02), we failed to detect any significant difference between Braak stage I and II. Also, the number of ht-NCI+ neurons remained stable in DRN between all stages 0 and II. Finally, the differential susceptibility to tau inclusions among nuclear subdivisions was more notable in LC than in DRN. CONCLUSIONS: LC and DRN neurons exhibited ht-NCI during AD precortical stages. The ht-NCI increases along AD progression on both nuclei, but quantitative changes in LC precede DRN changes.

SCIPA Com: outcomes from the spinal cord injury and physical activity in the community intervention.

STUDY DESIGN: Quasi-experimental translational study with pre- and post-measures. OBJECTIVES: To determine the effects of the Spinal Cord Injury and Physical Activity in the Community (SCIPA Com) intervention on leisure-time physical activity (LTPA) and associated outcomes among participants with spinal cord injury (SCI). SETTING: Young Men's Christian Associations and community fitness centers, Australia and New Zealand. METHODS: SCIPA Com consisted of three stages: (i) training exercise professionals via the Train the Trainers Spinal Cord Injury course; (ii) implementation of supervised physical activity programs twice a week for 30 to 60 min for 8 to 12 weeks; and (iii) follow-up assessments on health outcomes over 9 months. Participants with SCI were classified as active or inactive by baseline LTPA levels and linear mixed methods compared LTPA between groups over time. RESULTS: Sixty-four community-dwelling participants with SCI completed customized physical activity programs. Compared with baseline, there were significant improvements in LTPA (26 min per day, 95% confidence interval (CI): 16.6-35.4; P<0.001), functional goals (2, 95% CI: 1.72-2.37; P<0.001), self-esteem (1.5, 95% CI: 0.72-2.27; P<0.001) and overall quality of life (P<0.05). Over time, LTPA participation was greater among the active compared with the inactive group, although LTPA levels among the inactive improved compared with baseline. CONCLUSIONS: Significant improvements in LTPA participation and health outcomes were observed, especially among inactive individuals with SCI. SCIPA Com is an ecologically valid intervention based on training and support provided to community exercise professionals who, although new to adapted training, delivered effective physical activity programs for those at risk of inactivity. SPONSORSHIP: Transport Accident Commission (Project Number DP172) and the International Postgraduate Research Scholarship (IPRS), Curtin University.

Enabling dual cellular destinations of polymeric nanoparticles for treatment following partial injury to the central nervous system.

Following neurotrauma, oxidative stress is spread via the astrocytic syncytium and is associated with increased aquaporin 4 (AQP4), inflammatory cell infiltration, loss of neurons and glia and functional deficits. Herein we evaluate multimodal polymeric nanoparticles functionalized with an antibody to an extracellular epitope of AQP4, for targeted delivery of an anti-oxidant as a therapeutic strategy following partial optic nerve transection. Using fluorescence microscopy, spectrophotometry, correlative nanoscale secondary ion mass spectrometry (NanoSIMS) and transmission electron microscopy, in vitro and in vivo, we demonstrate that functionalized nanoparticles are coated with serum proteins such as albumin and enter both macrophages and astrocytes when administered to the site of a partial optic nerve transection in rat. Antibody functionalized nanoparticles synthesized to deliver the antioxidant resveratrol are effective in reducing oxidative damage to DNA, AQP4 immunoreactivity and preserving visual function. Non-functionalized nanoparticles evade macrophages more effectively and are found more diffusely, including in astrocytes, however they do not preserve the optic nerve from oxidative damage or functional loss following injury. Our study highlights the need to comprehensively investigate nanoparticle location, interactions and effects, both in vitro and in vivo, in order to fully understand functional outcomes.

Developing a spinal cord injury research strategy using a structured process of evidence review and stakeholder dialogue. Part II: Background to a research strategy.

STUDY DESIGN: Literature review/semi-structured interviews. OBJECTIVE: To develop a spinal cord injury (SCI) research strategy for Australia and New Zealand. SETTING: Australia. METHODS: The National Trauma Research Institute Forum approach of structured evidence review and stakeholder consultation was employed. This involved gathering from published literature and stakeholder consultation the information necessary to properly consider the challenge, and synthesising this into a briefing document. RESULTS: A research strategy 'roadmap' was developed to define the major steps and key planning questions to consider; next, evidence from published SCI research strategy initiatives was synthesised with information from four one-on-one semi-structured interviews with key SCI research stakeholders to create a research strategy framework, articulating six key themes and associated activities for consideration. These resources, combined with a review of SCI prioritisation literature, were used to generate a list of draft principles for discussion in a structured stakeholder dialogue meeting. CONCLUSION: The research strategy roadmap and framework informed discussion at a structured stakeholder dialogue meeting of 23 participants representing key SCI research constituencies, results of which are published in a companion paper. These resources could also be of value in other research strategy or planning exercises. SPONSORSHIP: This project was funded by the Victorian Transport Accident Commission and the Australian and New Zealand Spinal Cord Injury Network.

Developing a spinal cord injury research strategy using a structured process of evidence review and stakeholder dialogue. Part III: outcomes.

STUDY DESIGN: Focus Group. OBJECTIVES: To develop a unified, regional spinal cord injury (SCI) research strategy for Australia and New Zealand. SETTING: Australia. METHODS: A 1-day structured stakeholder dialogue was convened in 2013 in Melbourne, Australia, by the National Trauma Research Institute in collaboration with the SCI Network of Australia and New Zealand. Twenty-three experts participated, representing local and international research, clinical, consumer, advocacy, government policy and funding perspectives. Preparatory work synthesised evidence and articulated draft principles and options as a starting point for discussion. RESULTS: A regional SCI research strategy was proposed, whose objectives can be summarised under four themes. (1) Collaborative networks and strategic partnerships to increase efficiency, reduce duplication, build capacity and optimise research funding. (2) Research priority setting and coordination to manage competing studies. (3) Mechanisms for greater consumer engagement in research. (4) Resources and infrastructure to further develop SCI data registries, evaluate research translation and assess alignment of research strategy with stakeholder interests. These are consistent with contemporary international SCI research strategy development activities. CONCLUSION: This first step in a regional SCI research strategy has articulated objectives for further development by the wider SCI research community. The initiative has also reinforced the importance of coordinated, collective action in optimising outcomes following SCI.

Developing a spinal cord injury research strategy using a structured process of evidence review and stakeholder dialogue. Part I: rapid review of SCI prioritisation literature.

STUDY DESIGN: This is a rapid evidence review. OBJECTIVES: The objective of this study was to gain an overview of the volume, nature and findings of studies regarding priorities for spinal cord injury (SCI) research. SETTING: A worldwide literature search was conducted. METHODS: Six medical literature databases and Google Scholar were searched for reviews in which the primary aim was to identify SCI research priorities. RESULTS: Two systematic reviews were identified-one of quantitative and one of qualitative studies. The quality of the reviews was variable. Collectively, the reviews identified 31 primary studies; 24 quantitative studies totalling 5262 participants and 7 qualitative studies totalling 120 participants. Despite the difference in research paradigms, there was convergence in review findings in the areas of body impairments and relationships. The vast majority of literature within the reviews focused on the SCI patient perspective. CONCLUSION: The reviews inform specific research topics and highlight other important research considerations, most notably those pertaining to SCI patients' perspectives on quality of life, which may be of use in determining meaningful research outcome measures. The views of other SCI research stakeholders such as researchers, clinicians, policymakers, funders and carers would help shape a bigger picture of SCI research priorities, ultimately optimising research outputs and translation into clinical practice and health policy change. Review findings informed subsequent activities in developing a regional SCI research strategy, as described in two companion papers. SPONSORSHIP: This project was funded by the Victorian Transport Accident Commission and the Australian and New Zealand SCI Network.

Reactions of the rat musculoskeletal system to compressive spinal cord injury (SCI) and whole body vibration (WBV) therapy.

Traumatic spinal cord injury (SCI) causes a loss of locomotor function with associated compromise of the musculo-skeletal system. Whole body vibration (WBV) is a potential therapy following SCI, but little is known about its effects on the musculo-skeletal system. Here, we examined locomotor recovery and the musculo-skeletal system after thoracic (T7-9) compression SCI in adult rats. Daily WBV was started at 1, 7, 14 and 28 days after injury (WBV1-WBV28 respectively) and continued over a 12-week post-injury period. Intact rats, rats with SCI but no WBV (sham-treated) and a group that received passive flexion and extension (PFE) of their hind limbs served as controls. Compared to sham-treated rats, neither WBV nor PFE improved motor function. Only WBV14 and PFE improved body support. In line with earlier studies we failed to detect signs of soleus muscle atrophy (weight, cross sectional diameter, total amount of fibers, mean fiber diameter) or bone loss in the femur (length, weight, bone mineral density). One possible explanation is that, despite of injury extent, the preservation of some axons in the white matter, in combination with quadripedal locomotion, may provide sufficient trophic and neuronal support for the musculoskeletal system.

Functional deficits and morphological changes in the neurogenic bladder match the severity of spinal cord compression.

UNLABELLED: Following spinal cord injury (SCI), loss of spinal and supraspinal control results in desynchronisation of detrusor vesicae (parasympathicus) and external urethral sphincter (sympathicus) activity. Despite recovery of lower urinary tract function being a high priority in patients with SCI, effective treatment options are unavailable largely because mechanisms are poorly understood. PURPOSE AND METHODS: We used a clinically relevant model of thoracic SCI compression injury in adult female Wistar rats and confirmed that lesion volumes following severe injuries were significantly greater compared to moderate injuries (p < 0.05). Between 1-9 weeks, we assessed recovery of bladder function as well as return of locomotor function using the Basso, Beattie and Bresnahan (BBB) score. Bladder morphometrics and overall intramural innervation patterns, as assessed with ß-III tubulin immunohistochemistry, were also examined. RESULTS: Despite variability, bladder function was significantly worse following severe compared to moderate compression injury (p < 0.05); furthermore, the degree of bladder and locomotor dysfunction were significantly correlated (r = 0.59; p < 0.05). In addition, at 9 weeks after SCI we saw significantly greater increases in bladder dry weight (p < 0.05) and wall thickness following severe compared to moderate injury as well as increases in intramural axon density (moderate: 3× normal values; severe 5×; both p < 0.05) that also correlated with injury severity (r = 0.89). CONCLUSION: The moderate and severe compression models show consistent and correlated deficits in bladder and locomotor function, as well as in gross anatomical and histopathological changes. Increased intramural innervation may contribute to neurogenic detrusor overactivity and suggests the use of therapeutic agents which block visceromotoric efferents.

Non-invasive stimulation of the vibrissal pad improves recovery of whisking function after simultaneous lesion of the facial and infraorbital nerves in rats.

We have recently shown that manual stimulation of target muscles promotes functional recovery after transection and surgical repair to pure motor nerves (facial: whisking and blink reflex; hypoglossal: tongue position). However, following facial nerve repair, manual stimulation is detrimental if sensory afferent input is eliminated by, e.g., infraorbital nerve extirpation. To further understand the interplay between sensory input and motor recovery, we performed simultaneous cut-and-suture lesions on both the facial and the infraorbital nerves and examined whether stimulation of the sensory afferents from the vibrissae by a forced use would improve motor recovery. The efficacy of 3 treatment paradigms was assessed: removal of the contralateral vibrissae to ensure a maximal use of the ipsilateral ones (vibrissal stimulation; Group 2), manual stimulation of the ipsilateral vibrissal muscles (Group 3), and vibrissal stimulation followed by manual stimulation (Group 4). Data were compared to controls which underwent surgery but did not receive any treatment (Group 1). Four months after surgery, all three treatments significantly improved the amplitude of vibrissal whisking to 30° versus 11° in the controls of Group 1. The three treatments also reduced the degree of polyneuronal innervation of target muscle fibers to 37% versus 58% in Group 1. These findings indicate that forced vibrissal use and manual stimulation, either alone or sequentially, reduce target muscle polyinnervation and improve recovery of whisking function when both the sensory and the motor components of the trigemino-facial system regenerate.

Poor functional recovery and muscle polyinnervation after facial nerve injury in fibroblast growth factor-2-/- mice can be improved by manual stimulation of denervated vibrissal muscles.

Functional recovery following facial nerve injury is poor. Adjacent neuromuscular junctions (NMJs) are "bridged" by terminal Schwann cells and numerous regenerating axonal sprouts. We have recently shown that manual stimulation (MS) restores whisking function and reduces polyinnervation of NMJs. Furthermore, MS requires both insulin-like growth factor-1 (IGF-1) and brain-derived neurotrophic factor (BDNF). Here, we investigated whether fibroblast growth factor-2 (FGF-2) was also required for the beneficial effects of MS. Following transection and suture of the facial nerve (facial-facial anastomisis, FFA) in homozygous mice lacking FGF-2 (FGF-2(-/-)), vibrissal motor performance and the percentage of poly-innervated NMJ were quantified. In intact FGF-2(-/-) mice and their wildtype (WT) counterparts, there were no differences in amplitude of vibrissal whisking (about 50°) or in the percentage of polyinnervated NMJ (0%). After 2 months FFA and handling alone (i.e. no MS), the amplitude of vibrissal whisking in WT-mice decreased to 22±3°. In the FGF-2(-/-) mice, the amplitude was reduced further to 15±4°, that is, function was significantly poorer. Functional deficits were mirrored by increased polyinnervation of NMJ in WT mice (40.33±2.16%) with polyinnervation being increased further in FGF-2(-/-) mice (50.33±4.33%). However, regardless of the genotype, MS increased vibrissal whisking amplitude (WT: 33.9°±7.7; FGF-2(-/-): 33.4°±8.1) and concomitantly reduced polyinnervation (WT: 33.9%±7.7; FGF-2(-/-): 33.4%±8.1) to a similar extent. We conclude that, whereas lack of FGF-2 leads to poor functional recovery and target reinnervation, MS can nevertheless confer some functional benefit in its absence.

The AuSpinal: a test of hand function for people with tetraplegia.

STUDY DESIGN: Five-phased reliability and validity study. OBJECTIVES: To develop and test an assessment tool designed to quantify unilateral hand function in people with tetraplegia. SETTING: Seven spinal injury units in Australia. METHODS: The AuSpinal is a new assessment tool comprising seven tasks designed to quantify unilateral hand function in people with tetraplegia. There were five phases in this study: (1) development of the AuSpinal; (2) testing the test-retest and intrarater reliability of repeat ratings of 84 videos as determined by 13 therapists; (3) testing the interrater reliability and internal consistency of simultaneous real-life ratings of eight hands as determined by six therapists; (4) testing the range of scores from cross-sectional data obtained from 50 hands; and (5) quantifying sensitivity to change from longitudinal data collected over the course of rehabilitation from 16 hands. RESULTS: The test-retest, intrarater and interrater reliabilities were high (intraclass correlation coefficients ranged from 0.79 to 0.98, 95% CI ranged from 0.72 to 1.0) with a Cronbach α-value of 0.93. There was a reasonable range in the scores obtained from the cross-sectional data of the 50 hands (interquartile range extended from 6 to 14). There was an obvious and marked change in AuSpinal scores over the course of patients' rehabilitation in 8 of the 16 hands. CONCLUSION: The AuSpinal provides a quick and reliable instrument to test hand function in people with tetraplegia. It is useful for people with poor hand function but requires the addition of more complex tasks for those with good hand function.

Recovery of whisking function after manual stimulation of denervated vibrissal muscles requires brain-derived neurotrophic factor and its receptor tyrosine kinase B.

Functional recovery following facial nerve injury is poor. Neuromuscular junctions (NMJs) are "bridged" by terminal Schwann cells and numerous regenerating axonal sprouts. We have shown that this poly-innervation of NMJs can be reduced by manual stimulation (MS) with restoration of whisking function. In addition, we have recently reported that insulin-like growth factor-1 (IGF-1) is required to mediate the beneficial effects of MS. Here we extend our findings to brain derived neurotrophic factor (BDNF). We then examined the effect of MS after facial-facial anastomosis (FFA) in heterozygous mice deficient in BDNF (BDNF(+/-)) or in its receptor TrkB (TrkB(+/-)). We quantified vibrissal motor performance and the percentage of NMJ bridged by S100-positive terminal Schwann cells. In intact BDNF(+/-) or TrkB(+/-) mice and their wild type (WT) littermates, there were no differences in vibrissal whisking nor in the percentage of bridged NMJ (0% in each genotype). After FFA and handling alone (i.e. no MS) in WT animals, vibrissal whisking amplitude was reduced (60% lower than intact) and the percentage of bridged NMJ increased (27% more than intact). MS improved both the amplitude of vibrissal whisking (not significantly different from intact) and the percentage of bridged NMJ (11% more than intact). After FFA and handling in BDNF(+/-) or TrkB(+/-) mice, whisking amplitude was again reduced (53% and 60% lower than intact) and proportion of bridged NMJ increased (24% and 29% more than intact). However, MS failed to improve outcome in both heterozygous strains (whisking amplitude 55% and 58% lower than intact; proportion of bridged NMJ 27% and 18% more than intact). We conclude that BDNF and TRkB are required to mediate the effects of MS on target muscle reinnervation and recovery of whisking function.

An assessment of oxygen transfer efficiency in a gas permeable hollow fibre membrane biological reactor.

The clean water oxygen transfer efficiency (OTE) of a full scale non-porous hollow fibre gas permeable (GP) membrane (surface area of 500 m(2)) was evaluated at inlet air pressures of 1.2, 1.4, and 1.8 atm using two established testing methods. To form a basis of comparison with traditional aeration technologies, additional testing was done with conventional aerators (fine bubble and coarse bubble diffusers) replacing the GP membrane. OTE can be established based on the re-aeration of deoxygenated water or by monitoring the catalytic oxidation of a sodium sulphite (Na(2)SO(3)) solution. In this study, OTE values determined by sulphite oxidation (SOTE(S)) were consistently higher than those established during re-aeration (SOTE(R)) suggesting that the chemical reaction was enhancing the mass transfer. The chemical reaction was sufficiently fast in the case of the GP membrane, that the gas phase limited the mass transfer. The GP membrane operating at 1.2 atm had a SOTE(S) of 70.6% and a SOTER of 52.2%. SOTE(R) for the coarse bubble and fine bubble diffusers were 3.8% and 23.6%, respectively. This is comparable to the manufacturer's values, corrected for depth of 3.4% and 18.3%, respectively. Particularly, the derived OTE values were used to evaluate differences in energy consumption for a conventional treatment plant achieving carbon removal and nitrification. This analysis highlights the potential energy efficiency of GP membranes, which could be considered for the design of the membrane modules.

Recovery of whisking function promoted by manual stimulation of the vibrissal muscles after facial nerve injury requires insulin-like growth factor 1 (IGF-1).

Recently, we showed that manual stimulation (MS) of denervated vibrissal muscles enhanced functional recovery following facial nerve cut and suture (FFA) by reducing poly-innervation at the neuro-muscular junctions (NMJ). Although the cellular correlates of poly-innervation are established, with terminal Schwann cells (TSC) processes attracting axon sprouts to "bridge" adjacent NMJ, molecular correlates are poorly understood. Since quantitative RT-PCR revealed a rapid increase of IGF-1 mRNA in denervated muscles, we examined the effect of daily MS for 2 months after FFA in IGF-1(+/-) heterozygous mice; controls were wild-type (WT) littermates including intact animals. We quantified vibrissal motor performance and the percentage of NMJ bridged by S100-positive TSC. There were no differences between intact WT and IGF-1(+/-) mice for vibrissal whisking amplitude (48 degrees and 49 degrees ) or the percentage of bridged NMJ (0%). After FFA and handling alone (i.e. no MS) in WT animals, vibrissal whisking amplitude was reduced (60% lower than intact) and the percentage of bridged NMJ increased (42% more than intact). MS improved both the amplitude of vibrissal whisking (not significantly different from intact) and the percentage of bridged NMJ (12% more than intact). After FFA and handling in IGF-1(+/-) mice, the pattern was similar (whisking amplitude 57% lower than intact; proportion of bridged NMJ 42% more than intact). However, MS did not improve outcome (whisking amplitude 47% lower than intact; proportion of bridged NMJ 40% more than intact). We conclude that IGF-I is required to mediate the effects of MS on target muscle reinnervation and recovery of whisking function.

Metallothionein induces a regenerative reactive astrocyte phenotype via JAK/STAT and RhoA signalling pathways.

Following central nervous system injury, astrocytes rapidly respond by undergoing a stereotypical pattern of molecular and morphological alterations termed "reactive" astrogliosis. We have reported previously that metallothioneins (MTs) are rapidly expressed by reactive astrocytes and that their secretion and subsequent interaction with injured neurons leads to improved neuroregeneration. We now demonstrate that exogenous MT induces a reactive morphology and elevated GFAP expression in cultured astrocytes. Furthermore, these astrogliotic hallmarks were mediated via JAK/STAT and RhoA signalling pathways. However, rather than being inhibitory, MT induced a form of astrogliosis that was permissive to neurite outgrowth and which was associated with decreased chondroitin sulphate proteoglycan (CSPG) expression. The results suggest that MT has an important role in mediating permissive astrocytic responses to traumatic brain injury.

Minor pathological changes are induced by naltrexone-poly(DL-lactide) implants in pregnant rats.

Oral naltrexone is used to treat alcohol and heroin dependence but is associated with poor patient compliance. Sustained-release preparations have been developed to overcome noncompliance. Many sustained-release preparations are composed of polymers combined with naltrexone. Limited data indicate that polymers induce variable levels of tissue reactivity and that naltrexone may increase this effect. A slow-release subcutaneous naltrexone-poly (DL-lactide) implant is currently being trialed to treat heroin dependence in Western Australia. A minority of women fall pregnant and, although tissue reactivity in nonpregnant humans is relatively minor, detailed chronological data during pregnancy are lacking. Histological changes in pregnant rats were assessed; a single active tablet containing poly[trans-3,6-dimethyl-1,4-dioxyane-2,5-dione] (DL-lactide) loaded with 25 mg of naltrexone was implanted subcutaneously, and tissue response was compared with inactive polymer implantation. Rats were timed mated at 13-26 days postimplant. Tissue assessment up to 75 days by a pathologist showed that naltrexone induced chronic inflammatory response in a dose-dependent manner, although still at a low level. Furthermore, for inactive implants, minimal foreign body reaction and fibrosis, together with low-level inflammation, suggested good long-term biocompatibility. We conclude that the Australian naltrexone-poly(DL-lactide) implant is tolerated in pregnant rats, reinforcing its potential role for managing alcohol and heroin dependence in pregnant humans.

VEGF-induced choroidal damage in a murine model of retinal neovascularisation.

BACKGROUND/AIMS: Photoreceptor-specific upregulation of vascular endothelial growth factor (VEGF) in a transgenic mouse model (Kimba) of retinal neovascularisation induces retinal vascular damage which appears similar to that in diabetic retinopathy. Here we have determined whether the choroidal vasculature is also affected in Kimba. METHODS: Kimba mice were assessed with fundus fluorescein angiography for mild, moderate or severe retinal vascular leakage prior to preparation of choroidal corrosion casts for quantitative analysis using scanning electron microscopy. VEGF was located immunohistochemically. RESULTS: Choroidal abnormalities included microaneurysms, constriction, shrinkage and dropout in the capillaries and tortuosity and loops in the arteries and veins which were similar to those observed in corrosion casts of the human choroid in diabetes. Similar to human diabetes, choroidal neovascularisation was not observed. The severity of choroidal damage correlated with the extent of retinal vascular leakage. In addition to the expected presence of VEGF in photoreceptors, VEGF was also detected in the pigment epithelium and choroid in the transgenic mice. CONCLUSION: We show that elevated retinal VEGF levels trigger pathophysiological changes in the choroid. We suggest that therapies to prevent vascular damage in diabetes must target both the retinal and choroidal vasculatures.