Management of idiopathic intracranial hypertension in pregnancy

Idiopathic intracranial hypertension is more common among women of reproductive age and is often encountered in pregnancy, either pre-existing and exacerbated by pregnancy-associated weight gain and hormonal changes or arising de novo. We report the case of a 33-year-old woman with progressive visual loss and intractable headache from 20 weeks' gestation requiring ventriculoperitoneal shunting during pregnancy. The risk of permanent maternal vision loss raises complex management dilemmas, when this must be balanced with the fetal and neonatal risks of treatment and possible premature delivery.

A flavin-dependent monooxgenase confers resistance to chlorantraniliprole in the diamondback moth, Plutella xylostella

The diamondback moth, Plutella xylostella, is a damaging pest of cruciferous crops, and has evolved resistance to many of the insecticides used for control, including members of the diamide class. Previous work on the molecular basis of resistance to diamides has documented mutations in the target-site, the ryanodine receptor, in resistant populations of P. xylostella worldwide. In contrast the role of metabolic resistance to this insecticide class is significantly less clear. Here we show that overexpression of a flavin-dependent monooxgenase (FMO) confers resistance to the diamide chlorantraniliprole in P. xylostella. Transcriptome profiling of diamide resistant strains, with and without target-site resistance, revealed constitutive over-expression of several transcripts encoding detoxification enzymes compared to susceptible strains. Two of these, CYP6BG1, and PxFMO2 were particularly highly overexpressed (33,000 and 14,700-fold, respectively) in a resistant strain (HAW) lacking target-site resistance. After 17 generations without diamide selection the resistance of the HAW strain fell by 52-fold and the expression of PxFMO2 by > 1300-fold, however, the expression of CYP6BG1 declined by only 3-fold. Generation of transgenic Drosophila melanogaster expressing these genes demonstrated that PxFMO2, but not CYP6BG1, confers resistance in vivo. Overexpression of PxFMO2 in the HAW strain is associated with mutations, including a putative transposable element insertion, in the promoter of this gene. These enhance the expression of a reporter gene when expressed in a lepidopteran cell line suggesting they are, at least in part, responsible for the overexpression of PxFMO2 in the resistant strain. Our results provide new evidence that insect FMOs can be recruited to provide resistance to synthetic insecticides.

Importance of Coping in the Relationship Between Executive Function and Quality of Life in People with Multiple Sclerosis

Background

Maximizing quality of life (QOL) for people with multiple sclerosis (MS) is a primary focus of health care management professionals. Research has shown a relationship between QOL and a person's coping style and that coping provides an indirect link between cognition and stress, depression, and anxiety in MS. This research assessed whether coping moderates or mediates the relationship between executive function and QOL in people with MS.

Methods

We assessed 107 people with relapsing-remitting (n = 83) or secondary progressive (n = 24) MS using executive function tasks and self-report coping and QOL inventories.

Results

Coping strategies that mediated the relationship between executive function and QOL in people with MS included behavioral disengagement, acceptance, growth, and religion, while moderating strategies were denial, active, religion, adaptive, and total coping indices. Less cognitively demanding coping strategies that were related to increased QOL in people with poorer executive function included acceptance, growth, and religion, and maladaptive strategies associated with poorer QOL were behavioral disengagement and denial.

Conclusions

These results suggest that lessening avoidant coping strategies and strengthening use of less cognitively demanding adaptive coping strategies may improve QOL in people with MS who experience deficits in executive function. Consideration should be given to the development of psychoeducation and interventions with this focus.

Target Coping Strategies for Interventions Aimed at Maximizing Psychosocial Adjustment in People with Multiple Sclerosis

Background

The experience of psychological distress is prevalent in people with multiple sclerosis (MS), including high levels of stress, anxiety, and depression. It has been shown that people with MS use less adaptive coping compared with healthy individuals. This study examined the ability of coping strategies to predict maladaptive and adaptive psychosocial outcomes across areas of stress, depression, anxiety, and quality of life (QOL) in people with MS.

Methods

107 people with MS completed measures of depression (Beck Depression Inventory-II), anxiety (State-Trait Anxiety Inventory), QOL (Multiple Sclerosis Quality of Life-54), stress (Daily Hassles Scale), and coping (COPE inventory).

Results

Consistent with expectations, depression, frequency of stress, trait anxiety, and mental health QOL were predicted by adaptive and maladaptive coping styles. Severity of stressful events was predicted by maladaptive, but not adaptive, coping styles. Depression and mental health QOL were most prominently connected to coping use. Emotional preoccupation and venting showed the strongest relationship with poorer psychosocial outcomes, whereas positive reinterpretation and growth seemed to be most beneficial.

Conclusions

The results of this study highlight the importance of intervention programs targeting specific coping strategies to enhance psychosocial adjustment for people with MS.

Executive function is an important consideration for coping strategy use in people with multiple sclerosis

INTRODUCTION

Executive function deficits are prevalent in people with multiple sclerosis (PwMS), and PwMS use less adaptive coping than healthy controls. This cross-sectional study assessed whether there is a relationship between executive function and coping in PwMS.

METHOD

One hundred and seven participants with relapsing remitting or secondary progressive MS (n = 83 and 24, respectively; age M = 48.8 ± 11.1 years) completed measures of coping and executive function.

RESULTS

A positive relationship was found between verbal fluency and use of active, emotional, and instrumental social support coping, and total executive function and substance abuse coping. There was a negative relationship between coping strategies and core (social support, acceptance, religion, restraint, and total coping), higher order (denial and humor), and total executive function indices (acceptance, religion, behavioral disengagement, denial, and total coping).

CONCLUSION

These directional differences provide support for the importance of specific executive functions in coping strategy utilization. Understanding these relationships will assist psychologists and neuropsychologists with patient psychoeducation, adaptive coping strategy intervention and management for PwMS with reduced executive function ability.

Understanding the transmission dynamics of Leishmania donovani to provide robust evidence for interventions to eliminate visceral leishmaniasis in Bihar, India

Visceral Leishmaniasis (VL) is a neglected vector-borne disease. In India, it is transmitted to humans by Leishmania donovani-infected Phlebotomus argentipes sand flies. In 2005, VL was targeted for elimination by the governments of India, Nepal and Bangladesh by 2015. The elimination strategy consists of rapid case detection, treatment of VL cases and vector control using indoor residual spraying (IRS). However, to achieve sustained elimination of VL, an appropriate post elimination surveillance programme should be designed, and crucial knowledge gaps in vector bionomics, human infection and transmission need to be addressed. This review examines the outstanding knowledge gaps, specifically in the context of Bihar State, India.The knowledge gaps in vector bionomics that will be of immediate benefit to current control operations include better estimates of human biting rates and natural infection rates of P. argentipes, with L. donovani, and how these vary spatially, temporally and in response to IRS. The relative importance of indoor and outdoor transmission, and how P. argentipes disperse, are also unknown. With respect to human transmission it is important to use a range of diagnostic tools to distinguish individuals in endemic communities into those who: 1) are to going to progress to clinical VL, 2) are immune/refractory to infection and 3) have had past exposure to sand flies.It is crucial to keep in mind that close to elimination, and post-elimination, VL cases will become infrequent, so it is vital to define what the surveillance programme should target and how it should be designed to prevent resurgence. Therefore, a better understanding of the transmission dynamics of VL, in particular of how rates of infection in humans and sand flies vary as functions of each other, is required to guide VL elimination efforts and ensure sustained elimination in the Indian subcontinent. By collecting contemporary entomological and human data in the same geographical locations, more precise epidemiological models can be produced. The suite of data collected can also be used to inform the national programme if supplementary vector control tools, in addition to IRS, are required to address the issues of people sleeping outside.

Coping mediates and moderates the relationship between executive functions and psychological adjustment in multiple sclerosis

OBJECTIVE

To identify the moderating and mediating relationship of different coping strategies between executive function and stress, depression and anxiety in people with multiple sclerosis (PwMS).

METHOD

Participants were 107 people with relapsing remitting or secondary progressive multiple sclerosis who were administered tasks of executive function and completed self-report measures of stress, depression, anxiety, and coping.

RESULTS

An indirect relationship was found between executive function and psychosocial adjustment through maladaptive coping strategies: behavioral and mental disengagement, and substance abuse; adaptive coping strategies: acceptance, active, positive reinterpretation, and growth, as well as for an index of adaptive coping. In general, a relationship was found between better performance on tasks of executive function and psychosocial adjustment when adaptive coping strategies were low, as opposed to high, or maladaptive coping strategies were high, as opposed to low. Some unexpected findings are also discussed.

CONCLUSION

Executive function and psychosocial adjustment is mediated and moderated by coping strategies used by PwMS. Well-preserved executive function provides relative protection from poorer adjustment in the presence of high maladaptive or low adaptive coping. PwMS who perform poorly on tasks of executive function benefit from using less cognitively demanding adaptive coping strategies to enhance adjustment outcomes and further research in this area would be advantageous to underpin effective intervention strategies.

Multiple sclerosis in Latin America: A different disease course severity? A collaborative study from the MSBase Registry

Limited data suggest that multiple sclerosis (MS) in Latin America (LA) could be less severe than in the rest of the world. The objective was to compare the course of MS between LA and other regions.

Up-regulation of silent information regulator 2 (Sir2) is associated with amphotericin B resistance in clinical isolates of Leishmania donovani

OBJECTIVE

Silent information regulator 2 (Sir2) is involved in parasite survival and apoptosis. Here, we aimed to explore the involvement of Sir2 in amphotericin B (AmB) resistance mechanism in Leishmania donovani.

METHODS

The expression levels of Sir2, MDR1 and NAD(+) biosynthetic pathway enzymes in AmB-resistant and -susceptible parasites were measured and total intracellular NAD(+)/NADH ratios were compared. Overexpression and knockout constructs of Sir2 were transfected in AmB-resistant and -susceptible parasites. Both resistant and susceptible parasites were inhibited with sirtinol for 4 h. The deacetylase activity of Sir2, the expression level of MDR1, the rate of AmB efflux, concentrations of reactive oxygen species (ROS) and levels of apoptosis were examined in WT, inhibited and transfected parasites, and the AmB susceptibility of the respective parasites was measured by determining the LD50 of AmB.

RESULTS

Levels of mRNA, protein and NAD(+)-dependent deacetylase activity of Sir2 were elevated in resistant versus susceptible parasites. Inhibition and/or deletion of Sir2 allele showed a decreased mRNA level of MDR1, lower drug efflux, increased ROS concentration, apoptosis-like phenomenon and decreased LD50 of AmB in resistant parasites. In contrast, Sir2 overexpression in susceptible parasites reversed drug susceptibility producing a resistant phenotype. This was associated with increased LD50 of AmB along with increased expression levels of MDR1, drug efflux and reduced concentrations of ROS, corresponding to decreased apoptosis of resistant to WT sensitive.

CONCLUSIONS

Sir2 plays a critical role in AmB resistance by regulating MDR1, ROS concentration and apoptosis-like phenomena and may be a new resistance marker for visceral leishmaniasis.

Comparative effectiveness of glatiramer acetate and interferon beta formulations in relapsing–remitting multiple sclerosis

Background:

The results of head-to-head comparisons of injectable immunomodulators (interferon β, glatiramer acetate) have been inconclusive and a comprehensive analysis of their effectiveness is needed.

Objective:

We aimed to compare, in a real-world setting, relapse and disability outcomes among patients with multiple sclerosis (MS) treated with injectable immunomodulators.

Methods:

Pairwise analysis of the international MSBase registry data was conducted using propensity-score matching. The four injectable immunomodulators were compared in six head-to-head analyses of relapse and disability outcomes using paired mixed models or frailty proportional hazards models adjusted for magnetic resonance imaging variables. Sensitivity and power analyses were conducted.

Results:

Of the 3326 included patients, 345–1199 patients per therapy were matched (median pairwise-censored follow-up was 3.7 years). Propensity matching eliminated >95% of the identified indication bias. Slightly lower relapse incidence was found among patients treated with glatiramer acetate or subcutaneous interferon β-1a relative to intramuscular interferon β-1a and interferon β-1b ( p≤0.001). No differences in 12-month confirmed progression of disability were observed.

Conclusion:

Small but statistically significant differences in relapse outcomes exist among the injectable immunomodulators. MSBase is sufficiently powered to identify these differences and reflects practice in tertiary MS centres. While the present study controlled indication, selection and attrition bias, centre-dependent variance in data quality was likely.

Risk of relapse phenotype recurrence in multiple sclerosis

OBJECTIVES

The aim was to analyse risk of relapse phenotype recurrence in multiple sclerosis and to characterise the effect of demographic and clinical features on this phenotype.

METHODS

Information about relapses was collected using MSBase, an international observational registry. Associations between relapse phenotypes and history of similar relapses or patient characteristics were tested with multivariable logistic regression models. Tendency of relapse phenotypes to recur sequentially was assessed with principal component analysis.

RESULTS

Among 14,969 eligible patients (89,949 patient-years), 49,279 phenotypically characterised relapses were recorded. Visual and brainstem relapses occurred more frequently in early disease and in younger patients. Sensory relapses were more frequent in early or non-progressive disease. Pyramidal, sphincter and cerebellar relapses were more common in older patients and in progressive disease. Women presented more often with sensory or visual symptoms. Men were more prone to pyramidal, brainstem and cerebellar relapses. Importantly, relapse phenotype was predicted by the phenotypes of previous relapses. (OR = 1.8-5, p = 10(-14)). Sensory, visual and brainstem relapses showed better recovery than other relapse phenotypes. Relapse severity increased and the ability to recover decreased with age or more advanced disease.

CONCLUSION

Relapse phenotype was associated with demographic and clinical characteristics, with phenotypic recurrence significantly more common than expected by chance.

Abamectin is metabolized by CYP392A16, a cytochrome P450 associated with high levels of acaricide resistance in Tetranychus urticae

Abamectin is one of the most important insecticides worldwide. It is used against major agricultural pests and insects of public health importance, as well as against endoparasites in animal health. Abamectin has been used successfully for the control of the spider mite Tetranychus urticae, a major agricultural pest with global distribution, an extremely diverse host range, and a remarkable ability to develop resistance against insecticides including abamectin. Target site resistance mutations may explain a large part of resistance, although genetic evidence and transcriptomic data indicated that additional mechanisms may also be implicated in the abamectin resistant phenotype. To investigate a functional link between cytochrome P450-mediated metabolism and abamectin resistance, we recombinantly expressed three cytochrome P450s (CYP392A16, CYP392D8 and CYP392D10) that have been associated with high levels of abamectin resistance in a resistant T. urticae strain isolated from Greece. CYP392A16 was expressed predominately in its P450 form however, both CYP392D8 and CYP392D10 were expressed predominately as P420, despite optimization efforts on expression conditions. CYP392A16 catalyses the hydroxylation of abamectin (Kcat=0.54 pmol/min/pmol P450; Km=45.9 μM), resulting in a substantially less toxic compound as confirmed by bioassays with the partially purified metabolite. However, CYP392A16 did not metabolize hexythiazox, clofentezine and bifenthrin, active ingredients that also showed reduced toxicity in the abamectin resistant strain. Among a number of fluorescent and luminescent substrates screened, Luciferin-ME EGE was preferentially metabolized by CYP392A16, and it may be a potential diagnostic probe for metabolic resistance detection and monitoring.

Optic nerve diffusion tensor imaging after acute optic neuritis predicts axonal and visual outcomes

Background

Early markers of axonal and clinical outcomes are required for early phase testing of putative neuroprotective therapies for multiple sclerosis (MS).

Objectives

To assess whether early measurement of diffusion tensor imaging (DTI) parameters (axial and radial diffusivity) within the optic nerve during and after acute demyelinating optic neuritis (ON) could predict axonal (retinal nerve fibre layer thinning and multi-focal visual evoked potential amplitude reduction) or clinical (visual acuity and visual field loss) outcomes at 6 or 12 months.

Methods

Thirty-seven patients presenting with acute, unilateral ON were studied at baseline, one, three, six and 12 months using optic nerve DTI, clinical and paraclinical markers of axonal injury and clinical visual dysfunction.

Results

Affected nerve axial diffusivity (AD) was reduced at baseline, 1 and 3 months. Reduced 1-month AD correlated with retinal nerve fibre layer (RNFL) thinning at 6 (R=0.38, p=0.04) and 12 months (R=0.437, p=0.008) and VEP amplitude loss at 6 (R=0.414, p=0.019) and 12 months (R=0.484, p=0.003). AD reduction at three months correlated with high contrast visual acuity at 6 (ρ = -0.519, p = 0.001) and 12 months (ρ = -0.414, p=0.011). The time-course for AD reduction for each patient was modelled using a quadratic regression. AD normalised after a median of 18 weeks and longer normalisation times were associated with more pronounced RNFL thinning and mfVEP amplitude loss at 12 months. Affected nerve radial diffusivity (RD) was unchanged until three months, after which time it remained elevated.

Conclusions

These results demonstrate that AD reduces during acute ON. One month AD reduction correlates with the extent of axonal loss and persistent AD reduction at 3 months predicts poorer visual outcomes. This suggests that acute ON therapies that normalise optic nerve AD by 3 months could also promote axon survival and improve visual outcomes.

Predictors and dynamics of postpartum relapses in women with multiple sclerosis

Background:

Several studies have shown that pregnancy reduces multiple sclerosis (MS) relapses, which increase in the early postpartum period. Postpartum relapse risk has been predicted by pre-pregnancy disease activity in some studies.

Objective:

To re-examine effect of pregnancy on relapses using the large international MSBase Registry, examining predictors of early postpartum relapse.

Methods:

An observational case–control study was performed including pregnancies post-MS onset. Annualised relapse rate (ARR) and median Expanded Disability Status Scale (EDSS) scores were compared for the 24 months pre-conception, pregnancy and 24 months postpartum periods. Clustered logistic regression was used to investigate predictors of early postpartum relapses.

Results:

The study included 893 pregnancies in 674 females with MS. ARR (standard error) pre-pregnancy was 0.32 (0.02), which fell to 0.13 (0.03) in the third trimester and rose to 0.61 (0.06) in the first three months postpartum. Median EDSS remained unchanged. Pre-conception ARR and disease-modifying treatment (DMT) predicted early postpartum relapse in a multivariable model.

Conclusion:

Results confirm a favourable effect on relapses as pregnancy proceeds, and an early postpartum peak. Pre-conception DMT exposure and low ARR were independently protective against postpartum relapse. This novel finding could provide clinicians with a strategy to minimise postpartum relapse risk in women with MS planning pregnancy.

Fluctuations of MS births and UV-light exposure

BACKGROUND

Patients with multiple sclerosis (MS) are more frequently born in spring when compared to autumn. Fluctuation of UV-light has been hypothesized to drive this phenomenon.

AIM

To assess the correlation between fluctuation of sunlight and birth season in persons with MS.

METHODS

For this record-linkage study, we collected from the international MSBase and the Italian MS iMed-web databases the dates of birth of 11,415 patients with MS from 36 centres from 15 countries worldwide and compared these to dates of live-births from national registries. From all participating sites, we collected data on UV-light fluctuation and assessed its correlation with seasonal fluctuation in MS births.

RESULTS

Compared with the reference cohort, an increased proportion of persons with MS were born in spring and a decreased proportion in autumn (odds ratio (OR) to be born in spring versus autumn = 1.158, χ² = 36.347, P < 0.001). There was no significantly increased fluctuation of MS births with increased quartile of ambient UV-light fluctuation (Ptrend = 0.086).

CONCLUSION

Seasonal fluctuation of MS births as found in this worldwide cohort of patients with MS did not correlate with variation in seasonal fluctuation of UV-light. Most likely, it results from a complex interplay between fluctuation of sunlight, behavioural factors, other environmental factors and (epi)genetic factors.

The evolving extension environment: implications for dairy scientists

This paper reviews current challenges in the Australian extension environment and provides a case for developing an adaptive extension platform for the dairy sector in Australia and New Zealand, to support evolving dairy farm systems. The variation in the public-sector engagement in extension, the diversity and number of extension providers and a relatively uncoordinated approach to define new extension roles, functions and professional requirements are current challenges for dairy extension across Australia. In the dairy sector, these challenges coincide with increasing demand for a responsive research, development, extension and education system in supporting the rapid evolution in dairy farming systems. Addressing these challenges is not an issue for extension alone; however, the required level of integration among research, development, extension and education in an environment where needs are changing and resources are scarce demands an engaged dairy-science profession. Drawing on international extension and agricultural innovation-system literature and earlier empirical research, the following three areas for development are proposed: (1) a professional development strategy that incorporates (i) an understanding of the new professional situations extension works within, (ii) leadership in cross-industry and cross-sector coordination concerning the nature of the changing client in research, development, extension and education system and (iii) clear priorities for extension; (2) a professional development plan that incorporates a workplace-learning approach; and (3) for extension specialists to be engaged in defining research priorities, the agenda for change and suitable pathways for change alongside other professional groups, including farming. This development agenda will, however, require an adaptive extension platform to advance these areas on behalf of farmers and public stakeholders.

Relationship between chronic demyelination of the optic nerve and short term axonal loss

BACKGROUND

Axonal loss is a major determinant of disability in multiple sclerosis (MS). While acute inflammatory demyelination is a principal cause of axonal transection and subsequent axonal degeneration in acute disease, the nature of chronic axonal loss is less well understood. In the current study, the relationship between degree of chronic demyelination and axonal degeneration was investigated using optic neuritis (ON) as a model.

METHOD

25 patients with a first episode of unilateral ON, good recovery of visual function and concurrent brain or spinal cord MRI lesions were enrolled. Axonal loss was assessed using change in retinal nerve fibre layer (RNFL) thickness between 1 and 3 years after ON. Optic nerve conduction was evaluated using latency of multifocal visual evoked potentials (mfVEP). The level of mfVEP latency delay at 12 and 36 months was considered indicative of the degree of permanent demyelination. Data from 25 age and gender matched normal controls were used for comparison.

RESULTS

RNFL thickness was significantly reduced in ON eyes at 12 months compared with controls but remained unchanged in fellow eyes. Average RNFL thickness demonstrated a small but significant reduction between 12 and 36 months for both ON and fellow eyes. Change in RNFL thickness between 12 and 36 months, however, did not correlate with the degree of mfVEP latency delay.

CONCLUSION

The results, therefore, show no association between the degree of permanent optic nerve demyelination (as measured by latency delay) and progressive axonal degeneration, at least in the early stages of the disease. The fact that fellow eyes demonstrated a similar degree of progressive axonal loss supports this suggestion.

Diffusion tensor imaging of the optic radiations after optic neuritis

Trans-synaptic degeneration could exacerbate neurodegeneration in multiple sclerosis (MS). We aimed to assess whether anterograde trans-synaptic degeneration could be identified in the primary visual pathway in vivo. Diffusion tensor imaging (DTI) was used to assess the optic radiations in 15 patients with previous optic nerve inflammation and 9 healthy volunteers. A probabilistic atlas of the optic radiations was created from healthy diffusion tractography data. Lengthwise profiles for DTI parameters (axial [λ(||) ], radial [λ(⟂) ] and mean diffusivity [MD], fractional anisotropy [FA] and the angle of deviation of the principal eigenvector [α]) were analyzed for patients and controls. Patients also underwent multifocal visual evoked potential (mfVEP) assessments to characterize the latency and amplitude of cortical potentials. Correlations were performed between mfVEP latency and amplitude in the left and right visual hemi-fields and DTI parameters in the contra-lateral optic radiations. Patients displayed a significant decrease in λ(||) within the body of both optic radiations, which significantly correlated with loss of mfVEP amplitude. Abnormal λ(⟂) and FA were detected bilaterally throughout the optic radiations in patients but the abnormality was not associated with amplitude reduction or latency prolongation of the mfVEP. An abnormal α value was observed in the left optic radiations of patients, and the α value in the body of the optic radiations also correlated with mfVEP amplitude loss. The assocation between bilateral DTI abnormalities within the optic radiations and loss of afferent electrical activity could indicate anterograde trans-synaptic degeneration occurs following optic neuritis.

Efficacy of intravenous tissue-type plasminogen activator in central retinal artery occlusion: report from a randomized, controlled trial

BACKGROUND AND PURPOSE

Central retinal artery occlusion is caused by a platelet-fibrin thrombus or embolic occlusion and is a stroke of the eye. Observational studies suggest that thrombolytics may restore ocular perfusion and visual function. We hypothesized that intravenous tissue-type plasminogen activator (tPA) administered within 24 hours of symptom onset might restore ocular perfusion and visual function.

METHODS

A placebo-controlled, randomized trial of intravenous tPA versus intravenous saline was performed in patients with clinically defined central retinal artery occlusion within 24 hours of symptom onset. tPA was administered at a total dose of 0.9 mg/kg, with 10% given as a 1-minute bolus and the remainder over 1 hour. An improvement of visual acuity of 3 lines or more was considered significant.

RESULTS

Twenty-five percent (2 of 8) of the tPA group experienced the primary outcome at 1 week after tPA versus none of the placebo group. One patient had an intracranial hemorrhage. The visual acuity improvement of these 2 patients was not sustained at 6 months. In both patients, tPA was administered within 6 hours of symptom onset.

CONCLUSIONS

Although essentially a negative study, it does add to the evidence base of reperfusion in central retinal artery occlusion by showing that the time window for intervention is likely to be <6 hours. Reocclusion is a potential problem and may require adjuvant anticoagulation. Future studies should concentrate on determining the efficacy of thrombolytics in the <6-hour time window. Clinical Trial Registration- URL: http://www.anzctr.org.au. Unique identifier: 83102.

Study of the Efficacy of Intravenous Tissue Plasminogen Activator in Central Retinal Artery Occlusion

Rationale

Central retinal artery occlusion is a stroke of the eye caused by a blockage of its main blood supply by platelet-fibrin clot. Systemic thrombolysis has been successful in restoring perfusion to ischaemic tissue by fibrin-platelet clot lysis in ischaemic stroke and myocardial infarction. Several open-label studies have demonstrated efficacy of thrombolysis in the treatment of central retinal artery occlusion, with up to 60–70% of treated subjects experiencing an improvement in visual acuity. Most of these are given intraarterially, which is an invasive procedure and not widely applicable to all treatment centres. An alternative is the intravenous infusion of tissue plasminogen activator using existing stroke thrombolysis protocols. A systematic review of all observational studies of intravenous tissue plasminogen activator in acute central retinal artery occlusion showed that 48·5% of subjects had a four line or more visual acuity improvement with an acceptable rate of haemorrhagic complications, creating the equipoise necessary to conduct a randomised controlled trial.

Aim

To determine the efficacy of intravenous thrombolysis in acute treatment of central retinal artery occlusion.

Design

A phase II, placebo-controlled, double-blind, randomised controlled trial comparing intravenous tissue plasminogen activator at 0·9 mg/kg to placebo (normal saline) 100 ml in a 1 : 1 block randomisation.

Study outcome

The primary outcome measure is an improvement of three lines or more on the Snellen visual acuity chart, which signifies a doubling of the visual angle.

A simple colorimetric assay for specific detection of glutathione-S transferase activity associated with DDT resistance in mosquitoes

Background

Insecticide-based methods represent the most effective means of blocking the transmission of vector borne diseases. However, insecticide resistance poses a serious threat and there is a need for tools, such as diagnostic tests for resistance detection, that will improve the sustainability of control interventions. The development of such tools for metabolism-based resistance in mosquito vectors lags behind those for target site resistance mutations.

Methodology/Principal Findings

We have developed and validated a simple colorimetric assay for the detection of Epsilon class Glutathione transferases (GST)-based DDT resistance in mosquito species, such as Aedes aegypti, the major vector of dengue and yellow fever worldwide. The colorimetric assay is based on the specific alkyl transferase activity of Epsilon GSTs for the haloalkene substrate iodoethane, which produces a dark blue colour highly correlated with AaGSTE2-2-overexpression in individual mosquitoes. The colour can be measured visually and spectrophotometrically.

Conclusions/Significance

The novel assay is substantially more sensitive compared to the gold standard CDNB assay and allows the discrimination of moderate resistance phenotypes. We anticipate that it will have direct application in routine vector monitoring as a resistance indicator and possibly an important impact on disease vector control.

Aedes mosquitoes transmit many human viral pathogens including dengue, yellow fever and chikungunya. Most of these pathogens have no specific treatment or vaccine and hence their control is reliant on controlling the mosquito vectors, which usually involves the use of insecticides. In order to prevent the alarming prospect of mosquito control failure due to the rapid selection and spread of insecticide resistance in several mosquito populations worldwide, it is essential that effective resistance management strategies are implemented and adhered to. The development of simple diagnostic tests for the early identification and monitoring of resistance is an important prerequisite for this task. Here, we describe the development of a simple colorimetric test for the detection of GSTE2-2/DDTase-based resistance in individual mosquitoes. The novel assay combines the most desirable features of specificity and sensitivity with the low cost and ease of use required for a routine test in endemic countries. It can have direct application in routine vector monitoring as a resistance indicator and help improve the sustainability of insecticide based control strategies.

Remyelination of optic nerve lesions: spatial and temporal factors

Optic neuritis provides an in vivo model to study demyelination. The effects of myelin loss and recovery can be measured by the latency of the multifocal visual evoked potentials. We investigated whether the extent of initial inflammatory demyelination in optic neuritis correlates with the remyelinating capacity of the optic nerve. Forty subjects with acute unilateral optic neuritis and good visual recovery underwent multifocal visual evoked potentials testing at 1, 3, 6 and 12 months. Average latency changes were analyzed. Extensive latency delay at baseline significantly improved over time with rate of recovery slowed down after 6 months. Magnitude of latency recovery was independent of initial latency delay. Latency recovery ranged from 7 to 17 ms across the whole patient cohort (average = 11.3 (3.1) ms) despite the fact that in a number of cases the baseline latency delay was more than 35—40 ms. Optic nerve lesions tend to remyelinate at a particular rate irrespective of the size of the initial demyelinated zone with smaller lesions accomplishing recovery more completely. The extent of the initial inflammatory demyelination is probably the single most important factor determining completeness of remyelination. The time period favorable to remyelination is likely to be within the first 6 months after the attack.

Aligning farm decision making and genetic information systems to improve animal production: methodology and findings from the Australian dairy industry

To date there has been little research into the way genetic improvement decisions are made in practice on Australian farms. This type of knowledge is important for guiding the design of programs to increase the use of genetic information and thereby the rate of genetic gain in animal production systems. This paper describes an approach to understanding farm decision making in order to improve the design of services to increase the use of genetic information in the Australian dairy industry. A mixed-method approach involving a national survey and regional focus groups was used to determine farmers’ perceptions of the genetic information system overall and the key features of bull selection decisions and information sources. The current genetic information system was found to have a strong reputation for ease of access, use and fit with the way farmers evaluated bulls. In the focus groups the farmers described their decision process as having an ‘ideal cow’ in mind that fitted their farming system (e.g. balancing survival, milk volume, milk components, mammary features, fertility, milking speed, etc.). Bull proofs were then screened to identify a batch of eligible bulls that were further screened for their specific situation. Focus groups of advisers generally concurred with the process described by farmers. Further, farmers tended to rely on one or two main information sources in making decisions. To address the issue of greater alignment between farmer decision making and use of genetic information through industry organisations requires a coordinated strategy and a comprehensive development program. Suggestions for activities to this end are outlined.

Fellow eye changes in optic neuritis correlate with the risk of multiple sclerosis

BACKGROUND

Recent studies demonstrate early diffuse central nervous system (CNS) inflammation in patients with multiple sclerosis (MS). The clinically unaffected (fellow) eye of patients with unilateral optic neuritis (ON) may reflect the status of normal-appearing white matter in the CNS, which can be assessed electrophysiologically.

OBJECTIVE

To study the relationship between electrophysiological parameters in the fellow eye of ON patients, and risk of conversion to MS.

METHODS

Forty-eight consecutive patients with acute unilateral ON were examined 12 months after ON of which 14 had MS, 19 remained high risk (HR) for MS, and 15 had low risk (LR) for MS according to McDonald's criteria. Twenty-five age-matched controls were also tested. Amplitude and latency of multifocal visual evoked potential (mfVEP) in the fellow eyes of patients at 12 months were analyzed and compared with controls.

RESULTS

Average mfVEP amplitude was 240 +/- 35, 232 +/- 36, 181 +/- 38, and 169 +/- 48 nV for controls, LR, HR, and MS groups respectively. Average mfVEP latency for controls, LR, HR, and MS patients was 139.7 +/- 5.5, 141.7 +/- 3.6, 145.9 +/- 8.9, and 152.0 +/- 9.9 ms respectively.

CONCLUSIONS

The magnitude of latency prolongation and amplitude decline 12 months after the initial episode was proportional to the risk of MS. The prognostic significance of these changes as predictors of subsequent MS should be investigated longitudinally.

Optic nerve diffusion changes and atrophy jointly predict visual dysfunction after optic neuritis

Recently, there has been strong interest in the development of imaging techniques to quantify axonal and myelin pathology in patients with multiple sclerosis (MS). Optic neuritis, a condition characterised by inflammatory demyelination of the optic nerve, is one of the commonest sites of MS relapse, and exhibits similar pathological alterations to MS lesions elsewhere in the central nervous system (CNS). Unlike other regions of the CNS, however, the function of the optic nerve can be accurately assessed using clinical measures, as well as electrophysiological techniques such as visual evoked potential recordings. Therefore, optic neuritis is useful for investigating the relationship between abnormalities in optic nerve structure, assessed using magnetic resonance imaging (MRI), and visual dysfunction, assessed clinically and electrophysiologically. The aims of the present study were to assess optic nerve structural abnormalities in patients with a history of unilateral optic neuritis using MRI, and then to identify correlations between abnormalities in optic nerve MRI and visual dysfunction. Ten controls and sixteen patients underwent high resolution optic nerve diffusion tensor imaging (DTI), T2- and T1-weighted MRI. In addition, Snellen visual acuity and the latency and amplitude of multifocal visual evoked potentials (mfVEP) were tested in all patients. Diffusion and volumetric MRI indices were correlated to mfVEP functional indices. Significant abnormalities were detected in MRI and mfVEP measures in patients' affected nerves compared to unaffected optic nerves or optic nerves from healthy controls. Reduced mfVEP amplitude in the affected side significantly correlated with both affected optic nerve atrophy (R=0.58, p=0.02) and reduced fractional anisotropy (FA) (R=0.52, p=0.04). However, atrophy and reduced FA did not correlate with each other. To further investigate this disassociation, we used linear regression analysis with optic nerve atrophy and optic nerve FA as independent variables and mfVEP amplitude as the dependent variable. The resulting linear regression model was highly significant (R=0.819, p=0.001). These results show that, 4 years after unilateral optic neuritis, MRI-based measures of optic nerve structural abnormalities (decreased anisotropy and volume) independently predict visual dysfunction.

Axonal loss and myelin in early ON loss in postacute optic neuritis

OBJECTIVE

To investigate the relation between retinal nerve fiber layer (RNFL) thickness and latency and amplitude of multifocal visual-evoked potentials (mfVEPs) in the postacute stage of optic neuritis in patients with early or possible multiple sclerosis.

METHOD

Thirty-two patients with clinical diagnosis of unilateral optic neuritis and magnetic resonance imaging lesions typical of demyelination and 25 control subjects underwent mfVEP and optical coherence tomography imaging.

RESULTS

Although there was significant reduction of RNFL thickness in the affected eyes (18.7%), a considerably larger decrease was observed for the amplitude of the mfVEPs (39.8%). Latency of the mfVEPs was also significantly delayed in optic neuritis eyes. In fellow eyes, the amplitude of mfVEPs was significantly reduced and the latency prolonged, but RNFL thickness remained unaltered. RNFL thickness correlated highly with the mfVEP amplitude (r = 0.90). There was also strong correlation between optical coherence tomography measure of axonal loss and mfVEP latency (r = -0.66).

INTERPRETATION

Although our findings demonstrate strong associations between structural and functional measures of optic nerve integrity, the functional loss was more marked. This fact, together with amplitude and latency changes of the mfVEPs observed in clinically normal fellow eyes, may indicate greater sensitivity of mfVEPs in detecting optic nerve abnormality or the presence of widespread inflammation in the central nervous system, or both. The significant correlation of the mfVEP latency with RNFL thickness suggests a role for demyelination in promoting axonal loss.

Multifocal VEP and OCT in optic neuritis: a topographical study of the structure-function relationship

PURPOSE

To investigate topographical relationship between amplitude of multifocal visual evoked potentials (mfVEP) and retinal nerve fibre layer (RNFL) thickness following acute optic neuritis (ON).

PATIENTS AND METHODS

Fifty patients with a clinical diagnosis of acute unilateral ON between 6 and 36 months prior to the study and 25 age-matched controls underwent mfVEP testing (Accumap V 2.1, ObjectiVision Pty Ltd, Sydney, Australia) and OCT imaging (fast RNFL protocol, Stratus, software version 3.0, Carl Zeiss Meditec, Inc., Dublin, CA). RNFL thickness and mfVEP amplitude were measured for upper, temporal and lower retinal sectors and corresponding areas of the visual field in affected eyes of ON patients and control eyes. Inter-eye asymmetry coefficients for both RNFL thickness and mfVEP amplitude were calculated for each zone, and corresponding coefficients were correlated between each other.

RESULTS

There was highly significant reduction of RNFL thickness and mean mfVEP amplitude in all three retinal sectors of the affected eye. Largest reduction of RNFL thickness was noticed in temporal sector and of mfVEP amplitude in corresponding central part of the visual field. RNFL thickness correlated highly with amplitude of the mfVEP derived from corresponding areas of the visual field in all three zones.

CONCLUSIONS

We demonstrated strong topographical associations between structural and functional measures of optic nerve integrity in patients with ON.

Vestibular Rehabilitation in Individuals with Inner-Ear Dysfunction: A Pilot Study

A randomised control prospective study was carried out examining patient outcomes after performing a 10-week vestibular home exercise programme. Thirty-two adults with vestibular dysfunction who reported vestibular symptoms negatively affecting daily life were enrolled. Test subjects were provided with an individualised vestibular rehabilitation programme designed by a physiotherapist. Control subjects received a set of strength and endurance exercises only. All subjects performed their exercises 3 times a day for 10 weeks. Subjective and objective patient measures were collected at 0, 6, 10 and 26 weeks. Results showed that both groups improved after beginning exercise, and that test subjects significantly benefited compared to the controls. These benefits were long term and measurable 6 months later. This study provides evidence that individualised vestibular exercises promote better outcomes for patients with vestibular dysfunction.

Uterine vein and maternal urinary levels of activin A and inhibin A in pre-eclampsia patients

OBJECTIVES

The aims of this study were to investigate if (i) urinary concentrations of activin A and inhibin A are altered in pre-eclampsia (PE) and (ii) to study the relationship between uterine vein and peripheral vein concentrations of these hormones in PE patients.

DESIGN AND METHOD

In a retrospective study, maternal peripheral vein and uterine vein serum and maternal urine samples collected at the time of delivery were analysed. There were three groups of patients; (i) group 1: term normal pregnancies (n = 19) (ii) group 2: patients who developed PE < or = 37 weeks (n = 17) and (iii) group 3: patients who developed PE 37-40 weeks (n = 8). Serum and urinary activin A, follistatin, inhibin A and pro alpha C and urinary creatinine levels were measured using enzyme immunoassays in the laboratory.

RESULTS

Normal pregnant urine samples had very low levels of activin A and inhibin A. Both groups 2 and 3 PE patients had significantly higher levels of inhibin A (P < 0.001) and activin A (P < 0.001) compared to the controls. Pro-alpha C was not altered and follistatin was below the detection limit of the assay in the urine. Maternal peripheral serum activin A and inhibin A were significantly higher in groups 2 (P < 0.001) and 3 (P < 0.05) patients compared to the controls. Pro-alpha C-containing inhibins were higher in group 2 patients (P < 0.05) compared to the controls in the peripheral circulation. Uterine vein serum activin A and inhibin A levels were also significantly higher in groups 2 (P < 0.001) and 3 (P < 0.05) patients compared to the controls. There was a highly significant positive correlation between peripheral and uterine vein serum concentrations of activin A, follistatin, inhibin A and pro alpha C, suggesting the same source for these proteins in PE.

CONCLUSION

Urinary activin A and inhibin A are raised in groups 2 and 3 PE patients. The magnitude of rise (> 25-fold) suggests these proteins may rise in patients before the onset of the clinical symptoms of PE. Uterine vein levels of these proteins are also raised in PE.

Predictors of Recurrent Ischemic Optic Neuropathy in Giant Cell Arteritis

BACKGROUND

The competing interests of preventing recurrent ischemic optic neuropathy (ION) and minimizing medication side effects make corticosteroid dose reduction in giant cell arteritis (GCA) a difficult problem. The authors sought to determine whether any factors were predictive of recurrent ION.

METHODS

Retrospective review of the records of 100 consecutive patients with biopsy-proven giant cell arteritis diagnosed in two Australian hospitals between 1988 and 1998. Among 67 patients who met inclusion criteria for ION in GCA, seven patients had recurrent ION. We compared the seven patients with recurrent ION to the 60 patients with nonrecurrent ION in terms of age, gender, mode of corticosteroid delivery, initial visual acuity in the affected eye, prevalence of bilateral ION, initial erythrocyte sedimentation rate (ESR) level, and rate of corticosteroid dose reduction. In the recurrent ION group, we documented the timing of the recurrence in relation to corticosteroid dose, elevation in acute phase reactants, and relapse of systemic symptoms.

RESULTS

We found recurrent ION in GCA in 10% of our cohort, higher than has been previously reported. Recurrences, all of which were ipsilateral, occurred from 3 to 36 months (median 8 months) after the initial ION. None of the clinical indicators the authors examined differed between the two groups. Six of seven patients with recurrent ION had elevations in ESR or C-reactive protein or a new headache at the time of ION recurrence, but in only one of these patients were these features recognized as preceding the recurrent ION. One patient had neither an elevation in acute phase reactants nor a relapse in systemic symptoms of GCA at the time of ION recurrence.

CONCLUSIONS

Recurrent ION in GCA is difficult to predict. Although elevated acute phase reactants or new systemic symptoms consistent with GCA were present in six (83%) of our patients with ION recurrence, in only one patient (17%) did these events occur with enough lead time to allow caregivers to act preemptively. Thus, even very close monitoring of GCA patients with ION may not predict ION recurrence.

Visual disturbances representing occipital lobe epilepsy in patients with cerebral calcifications and coeliac disease: a case series

Paroxysmal visual manifestations may represent epileptic seizures arising from the occipital lobe. In coeliac disease (CD) bilateral occipital calcifications and seizure semiology consistent with an occipital origin have been described, primarily in Mediterranean countries. By reporting three adult patients from an Australian outpatient clinic with visual disturbances, occipital cerebral calcifications, and CD, this study seeks to emphasise that CD should be considered even when patients of non-Mediterranean origin present with these symptoms. Seizure types included simple partial, complex-partial, and secondarily generalised seizures. The seizure semiology consisted of visual disturbances such as: blurred vision, loss of focus, seeing coloured dots, and brief stereotyped complex visual hallucinations like seeing unfamiliar faces or scenes. Symptoms of malabsorption were not always present. Neurological examination was unremarkable in two patients, impaired dexterity and mild hemiatrophy on the left was noted in one. Routine electroencephalography was unremarkable. In all cases, computed tomography demonstrated bilateral cortical calcification of the occipital-parietal regions. Magnetic resonance imaging showed no additional lesion. All patients had biopsy confirmed CD. Seizure control improved after treatment with gluten free diet and anticonvulsants. This report illustrates the association between seizures of occipital origin, cerebral calcifications, and CD even in patients not of Mediterranean origin.

Immunotherapy of ocular myasthenia gravis reduces conversion to generalized myasthenia gravis

BACKGROUND

Several retrospective studies have suggested that immunotherapy, including prednisolone, azathioprine and thymectomy, reduces progression of ocular myasthenia gravis to generalized myasthenia gravis. This study examines the effect of immunotherapy on generalization rates in ocular myasthenia patients who are acetylcholine receptor (AChR) antibody-positive.

METHODS

Retrospective record review of 34 patients from three university-based hospitals with neurology and neuro-ophthalmology services in Australia. In all patients, positive AChR antibodies were recorded, the initial symptoms were purely ocular, and all had at least 2 years of follow-up. The patients who developed generalized myasthenia gravis were compared with those who remained purely ocular.

RESULTS

There were 21 patients who developed generalized myasthenia gravis. Of these 21, only 2 (9.5%) had received prior immunotherapy. Among the 13 patients whose symptoms remained purely ocular, 10 (76.9%) had received prior immunotherapy.

CONCLUSIONS

In this study, most of the patients who progressed from ocular myasthenia to generalized myasthenia had not received prior immunotherapy. This study adds weight to the call for a prospective trial of early immunotherapy in patients with ocular myasthenia.