Intravitreal delivery of AAV-NDI1 provides functional benefit in a murine model of Leber hereditary optic neuropathy

Leber hereditary optic neuropathy (LHON) is a mitochondrially inherited form of visual dysfunction caused by mutations in several genes encoding subunits of the mitochondrial respiratory NADH-ubiquinone oxidoreductase complex (complex I). Development of gene therapies for LHON has been impeded by genetic heterogeneity and the need to deliver therapies to the mitochondria of retinal ganglion cells (RGCs), the cells primarily affected in LHON. The therapy under development entails intraocular injection of a nuclear yeast gene NADH-quinone oxidoreductase (NDI1) that encodes a single subunit complex I equivalent and as such is mutation independent. NDI1 is imported into mitochondria due to an endogenous mitochondrial localisation signal. Intravitreal injection represents a clinically relevant route of delivery to RGCs not previously used for NDI1. In this study, recombinant adenoassociated virus (AAV) serotype 2 expressing NDI1 (AAV-NDI1) was shown to protect RGCs in a rotenone-induced murine model of LHON. AAV-NDI1 significantly reduced RGC death by 1.5-fold and optic nerve atrophy by 1.4-fold. This led to a significant preservation of retinal function as assessed by manganese enhanced magnetic resonance imaging and optokinetic responses. Intraocular injection of AAV-NDI1 overcomes many barriers previously associated with developing therapies for LHON and holds great therapeutic promise for a mitochondrial disorder for which there are no effective therapies.

Breast-feeding is associated with reduced postpartum maternal glucose intolerance after gestational diabetes

Gestational diabetes mellitus (GDM) is associated with adverse foetal and maternal outcomes, and identifies women at risk of future Type 2 Diabetes Mellitus (T2DM). Breast-feeding may improve postpartum maternal glucose tolerance. We prospectively examined the prevalence of postpartum dysglycaemia after GDM and examined the effect of lactation on postpartum glucose tolerance. We compared postpartum 75g oral glucose tolerance test (OGTT) results from 300 women with GDM and 220 controls with normal gestational glucose tolerance (NGT). Breast-feeding data was collected at time of OGTT. Postpartum OGTT results were classified as normal [fasting plasma glucose (FPG) < 5.6mmol/l, 2-h < 7.8 mmol/l] and abnormal [impaired fasting glucose (IFG), FPG 5.6-6.9 mmol/l; impaired glucose tolerance (IGT), 2-h glucose 7.8-11 mmol/l; IFG+IGT; T2DM, FPG > or = 7 mmol/l +/- 2h glucose > or = 11.1 mmol/l]. 6 (2.7%) with NGT in pregnancy had postpartum dysglycaemia compared to 57 (19%) with GDM in index pregnancy (p < 0.001). Non-European ethnicity (OR 3.40, 95% CI 1.45-8.02, p = 0.005), family history of T2DM (OR 2.14, 95% CI 1.06-4.32, p = 0.034) and gestational insulin use (OR 2.62, 95% CI 1.17-5.87 p = 0.019) were associated with persistent dysglycaemia. The prevalence of persistent hyperglycaemia was significantly lower in women who breast-fed versus bottle-fed postpartum (8.2% v 18.4%, p < 0.001). Breast-feeding may confer beneficial metabolic effects after GDM and should be encouraged.

Atlantic DIP: the prevalence and consequences of gestational diabetes in Ireland

ATLANTIC DIP carried out a universal screening programme for gestational diabetes mellitus (GDM) along the Irish Atlantic seaboard. Using a 75g OGTT and new International Association of Diabetes in Pregnancy Study Groups (IADPSG) cut off points for diagnosis we found the prevalence of GDM to be 12.4%. Pregnancies complicated by GDM displayed increased morbidities for mother and infant when compared to women who had normal glucose tolerance. With rising obesity levels and older age of mothers, both risk factors for GDM, these results would support a national universal screening programme.

A cost analysis of febrile neutropenia management in Australia: ambulatory v. in-hospital treatment

BACKGROUND

Adult febrile neutropenic oncology patients, at low risk of developing medical complications, may be effectively and safely managed in an ambulatory setting, provided they are appropriately selected and adequate supportive facilities and clinical services are available to monitor these patients and respond to any clinical deterioration.

METHODS

A cost analysis was modelled using decision tree analysis, published cost and effectiveness parameters for ambulatory care strategies and data from the State of Victoria's hospital morbidity dataset. Two-way sensitivity analyses and Monte Carlo simulation were performed to evaluate the uncertainty of costs and outcomes associated with ambulatory care.

RESULTS

The modelled cost analysis showed that cost savings for two ambulatory care strategies were ~30% compared to standard hospital care. The weighted average cost saving per episode of 'low-risk' febrile neutropenia using Strategy 1 (outpatient follow-up only) was 35% (range: 7-55%) and that for Strategy 2 (early discharge and outpatient follow-up) was 30% (range: 7-39%). Strategy 2 was more cost-effective than Strategy 1 and was deemed the more clinically favoured approach.

CONCLUSION

This study outlines a cost structure for a safe and comprehensive ambulatory care program comprised of an early discharge pathway with outpatient follow-up, and promotes this as a cost effective approach to managing 'low-risk' febrile neutropenic patients.

Platelet reactivity in type 2 diabetes mellitus: a comparative analysis with survivors of myocardial infarction and the role of glycaemic control

Patients with type 2 diabetes mellitus exhibit considerable platelet dysfunction, though this is poorly characterized in patients with diabetes taking aspirin for the primary prevention of cardiovascular events. We sought to compare platelet function in this patient population with that of a high-risk group of non-diabetic subjects with a history of previous myocardial infarction (MI), and to assess whether glycaemic control impacts on platelet function.

METHODS

Platelet aggregation was measured in response to incremental concentrations of five platelet agonists using light transmission aggregometry. All patients were taking aspirin, and aspirin insensitivity was defined as ≥ 20% arachidonic acid (AA) mediated aggregation. Patients with diabetes were divided according to glycaemic control (HbA(1c)): optimal ≤ 6.5, good 6.6-7.4 and suboptimal ≥ 7.5%.

RESULTS

In total, 85 patients with type 2 diabetes and 35 non-diabetic patients with previous MI were recruited. Compared to MI patients, diabetes patients had increased aggregation in response to multiple concentrations of epinephrine, collagen, adenosine diphosphate and AA. Aspirin insensitivity was more common in type 2 diabetes (15% vs. 0%, p=0.037). Platelet aggregation was increased in response to several agonists patients with suboptimal glycaemic control compared to patients with optimal control. Aspirin insensitivity was also more common in patients with suboptimal glycaemic control compared to those with good or optimal control (26.0% vs. 8.3% vs. 4%, p=0.04).

CONCLUSION

Patients with type 2 diabetes mellitus, without proven vascular disease, exhibit platelet dysfunction and have increased platelet aggregation and aspirin insensitivity compared to non-diabetic patients with previous MI. Platelet dysfunction in diabetes is more severe in patients with suboptimal glycaemic control.

The cost of universal screening for gestational diabetes mellitus in Ireland

AIMS

To estimate the costs associated with universal screening for gestational diabetes mellitus in Ireland.

METHODS

Bottom-up, prevalence-based cost analysis. Healthcare activity identified using the Atlantic Diabetes in Pregnancy (ATLANTIC DIP) database was grouped into five categories: screening and testing, gestational diabetes treatment, prenatal care, delivery care and neonatal care. A vector of unit cost data (euros in 2008 prices) was applied to specified resource use and the total healthcare cost calculated. A series of one-way and probabilistic sensitivity analyses were undertaken to explore the uncertainty in the analysis.

RESULTS

When individual resource components were valued and aggregated, the total healthcare cost of gestational diabetes in Ireland was estimated at €12 433 320 (95% CI €9 298 228-16 778 193). The average cost per case detected was €1621 (95% CI €524-2603) and the average total cost per case detected and treated was €11 903 (95% CI €7645-16 121).

CONCLUSIONS

This research provides the first estimates of the healthcare costs associated with gestational diabetes mellitus in Ireland. Further research is required to determine the cost-effectiveness of gestational diabetes screening in the region with a view to improving resource allocation in this area in the future.

Atlantic Diabetes in Pregnancy (DIP): the prevalence and outcomes of gestational diabetes mellitus using new diagnostic criteria

AIMS/HYPOTHESIS

New diagnostic criteria for gestational diabetes mellitus (GDM) have recently been published. We wished to evaluate what impact these new criteria would have on GDM prevalence and outcomes in a predominantly European population.

METHODS

The Atlantic Diabetes In Pregnancy (DIP) programme performed screening for GDM in 5,500 women with an oral glucose tolerance test at 24-28 weeks. GDM was defined according to the new International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria and compared with previous WHO criteria; maternal and neonatal adverse outcomes were prospectively recorded.

RESULTS

Of the participants, 12.4% and 9.4% were diagnosed with GDM using IADPSG and WHO criteria, respectively. IADPSG GDM pregnancies were associated with a statistically significant increased incidence of adverse maternal outcomes (gestational hypertension, polyhydramnios and Caesarean section) and neonatal outcomes (prematurity, large for gestational age, neonatal unit admission, neonatal hypoglycaemia and respiratory distress). The odds ratio for the development of these adverse outcomes remained significant after adjustment for maternal age, body mass index and non-European ethnicity. Those women who were classified as having normal glucose tolerance by WHO criteria but as having GDM by IADPSG criteria also had significant adverse pregnancy outcomes.

CONCLUSIONS/INTERPRETATION

GDM prevalence is higher when using newer IADPSG, compared with WHO, criteria, and these women and their offspring experience significant adverse pregnancy outcomes. Higher rates of GDM pose a challenge to healthcare systems, but improved screening provides an opportunity to attempt to reduce the associated morbidity for mother and child.

Use of empiric antimicrobial therapy in neutropenic fever. Australian Consensus Guidelines 2011 Steering Committee

Administration of empiric antimicrobial therapy is standard practice in the management of neutropenic fever, but there remains considerable debate about the selection of an optimal regimen. In view of emerging evidence regarding efficacy and toxicity differences between empiric treatment regimens, and strong evidence of heterogeneity in clinical practice, the current guidelines were developed to provide Australian clinicians with comprehensive guidance for selecting an appropriate empiric strategy in the setting of neutropenic fever. Beta-lactam monotherapy is presented as the treatment of choice for all clinically stable patients while early treatment with combination antibiotic therapy is considered for patients at higher risk. Due consideration is given to the appropriate use of glycopeptides in this setting. Several clinical caveats, accounting for institution- and patient-specific risk factors, are provided to help guide the judicious use of the agents described. Detailed recommendations are also provided regarding time to first dose, timing of blood cultures, selection of a first-line antibiotic regimen, subsequent modification of antibiotic choice and cessation of therapy.

Gene therapeutic approaches for dominant retinopathies

Over the past two decades, significant progress has been made in defining the molecular pathogenesis of hereditary retinal degenerations. Many of these are characterised by immense genetic heterogeneity. For example, in retinitis pigmentosa (RP), the most common form of this group of disorders, over 50 disease causing genes have been implicated, 20 of which are inherited in an autosomal dominant manner. Knowledge of the underlying genetic pathogenesis together with the availability of animal models and vectors for delivery has enabled exploration of gene-based therapies for inherited retinopathies. Notably, many studies have focused on treatment of recessive forms of these disorders and significant progress including ongoing clinical trials have been achieved. Progress in developing gene therapies for dominant retinopathies has been slower. One reason for this is that gene therapies for many dominant diseases, which are targeted to correcting the primary genetic defect, are likely to require suppression of the mutant gene. Alternative therapeutic approaches, which involve modulating secondary features associated with the disease pathology (such as ER stress or apoptosis) are also being explored. This review is focused on the development of gene-based therapies for dominantly inherited retinopathies. The main topics discussed are suppression technologies, preclinical animal models, retinal gene delivery and therapeutic strategies.

Characterisation of the Oxidation Kinetics of Thin, Low Temperature, Electroless Plated Copper Films

The morphology, chemical state and oxidation behaviour of electroless copper films deposited from two different baths were characterised using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS) and spectroscopic ellipsometry (SE). The electroless solutions used were a commercial electroless formaldehyde (HCHO)-based solution (Cupro-Thick 84, Alfachimici) and an electroless solution developed within the NMRC which was based on dimethylamine borane (DMAB). Both methods produced as-deposited copper films with different morphologies. SE analysis of the as-deposited films and those oxidised in a dry synthetic air environment between 75°C–150°C indicated that the freshly deposited films had inherent oxide layers of between 45Å–92Å and that significant growth of these only occurred at temperatures above 100°C within 180 minutes isothermal oxidation periods. XRD analysis confirmed that the oxidation products formed were a mixture of cuprous oxide (Cu2O) and cupric oxide (CuO). Multiple linear regression analysis of the rates of change in oxide layer thicknesses as a function of both time and temperature indicated that mixed rate laws dominated. The application of an oxidation inhibitor was shown to prevent oxidation of the asdeposited commercial copper films when heat treated at 125°C.

Adeno-associated virus-mediated rhodopsin replacement provides therapeutic benefit in mice with a targeted disruption of the rhodopsin gene

The rhodopsin gene (RHO) encodes a highly expressed G protein-coupled receptor that is central to visual transduction in rod photoreceptors. A suite of recombinant 2/5 adeno-associated viral (AAV) RHO replacement vectors has been generated in an attempt to recapitulate endogenous rhodopsin levels from exogenously delivered AAV vectors in the retina of mice with a targeted disruption in the rhodopsin gene (Rho(-/-) mice). Approximately 40% of wild-type mouse rhodopsin mRNA levels (RNA taken from whole retinas) was achieved in vivo in AAV-RHO-injected eyes, representing approximately 50-fold increases in expression compared with the initial vector. The main focus of this study was to test whether expression of AAV-RHO replacement in Rho(-/-) mice provided therapeutic benefit, which to date had not been achieved. Rho(-/-) mice neither elaborate rod outer segments nor have rod-derived electroretinograms (ERGs). Our results indicate for the first time in this model that subretinal AAV-RHO delivery leads not only to RHO immunolabeling but the generation of rod outer segments as evaluated by light and transmission electron microscopy. Improved histology was accompanied by rod photoreceptor activity as assessed by ERG for at least 12 weeks postinjection. The most efficient AAV-RHO constructs presented in this study provide sufficient levels of RHO to be of therapeutic benefit in Rho(-/-) mice and therefore represent important steps toward generating potent AAV-RHO replacement genes for gene therapy in RHO-linked human retinopathies.

'Speaking valve' aspiration in a laryngectomy patient

Tracheo-oesophageal speech using a one-way speaking valve is a common mode of speech rehabilitation for laryngectomy patients. Aspiration of this device can cause significant airway obstruction and pose anaesthetic and surgical challenges during its retrieval. In this case report, we describe our management of a patient who had had a laryngectomy who aspirated his speaking valve through his stoma. Emergency retrieval of the valve was performed, during which difficulties were encountered, first in obtaining an adequate seal for pre-oxygenation, and second in maintaining adequate oxygen saturation. We discuss some innovative techniques that could be used to address these issues.

2009 H1N1 influenza A and pregnancy outcomes in Victoria, Australia

BACKGROUND

Pregnant women have been identified as a group at risk of increased morbidity and mortality associated with the pandemic H1N1 influenza A 2009 (H1N1/09) outbreak.

METHODS

Six hospitals in the state of Victoria, Australia, contributed retrospective and prospective demographic and clinical data, reason for admission data, and maternal and fetal outcome data for women with laboratory-confirmed H1N1/09 admitted to the hospital from 20 May 2009 through 31 July 2009.

RESULTS

Forty-three cases were reported during the study period, including 8 intensive care unit admissions, 1 maternal death, 2 fetal deaths, and 1 neonatal death. The most common reason for admission was uncomplicated influenza-like illness. Patients hospitalized for uncomplicated influenza-like illness had a length of stay significantly less than those with confirmed pneumonia. Thirty-six percent of women delivered during the hospitalization. Of the women delivering before 37 weeks' gestation, almost all had pneumonia. Almost half of our case series had no other comorbidity, a large proportion (77%) of women received antivirals, and 56% received antibiotics. The incidence of hospitalization was estimated at 0.46% (95% confidence interval, 0.31%-0.66%) of all 6094 pregnant women in the third trimester during the 3-month study period. The incidence of hospitalization in the second trimester was estimated at 0.21% (95% confidence interval, 0.11%-0.36%).

CONCLUSIONS

This case series confirms a high number of complications in pregnant women due to pandemic H1N1/09. Many of these women had comorbidities, although almost 50% of the women in this case series who required hospitalization did not have an additional risk factor other than being pregnant.

Impact of cardiac rehabilitation on health related quality of life

Cardiac rehabilitation (CR) programs are recognized as integral part of the comprehensive care of patients with cardiovascular disease and are recommended as useful and effective (Class I) by the American Heart Association (AHA). In this study we used serial administration of the short form 36 (SF36) to evaluate patient's response to CR in terms of improvement in Health related Quality of Life. A total of 49 patients were included in the analysis. There was a significant improvement observed after CR in the Physical Capacity Score (42.3 vs 49.9 p = 0.0005). There was no significant improvement in the Mental Capacity Score (54.8 vs 54.9 p = 0.96). We conclude that Cardiac Rehabilitation Program causes a significant improvement in the health related quality of life of patients by improving their physical health and well being but does not improve the mental capacity which is already at a healthy level before CR.

Pseudo ventricular tachycardia: a case report

BACKGROUND

Dramatic artifacts of pseudo flutter have been reported in the past secondary to various factors including tremor (Handwerker and Raptopoulos in N Engl J Med 356:503, 2007) and dialysis machines (Kostis et al. in J Electrocardiol 40(4):316-318, 2007).

METHODS

We present this unusual case where the artifact, produced by tremor, was so pronounced to be misdiagnosed and treated as ventricular tachycardia.

CONCLUSION

This case highlights the importance of correlating ECG findings with history and clinical examination and of using 12 lead ECGs for rhythm interpretation especially to confirm consistence of arrhythmias in all leads.