Rilpivirine analogs potently inhibit drug-resistant HIV-1 mutants

Background

Nonnucleoside reverse transcriptase inhibitors (NNRTIs) are a class of antiretroviral compounds that bind in an allosteric binding pocket in HIV-1 RT, located about 10 Å from the polymerase active site. Binding of an NNRTI causes structural changes that perturb the alignment of the primer terminus and polymerase active site, preventing viral DNA synthesis. Rilpivirine (RPV) is the most recent NNRTI approved by the FDA, but like all other HIV-1 drugs, suboptimal treatment can lead to the development of resistance. To generate better compounds that could be added to the current HIV-1 drug armamentarium, we have developed several RPV analogs to combat viral variants that are resistant to the available NNRTIs.

Results

Using a single-round infection assay, we identified several RPV analogs that potently inhibited a broad panel of NNRTI resistant mutants. Additionally, we determined that several resistant mutants selected by either RPV or Doravirine (DOR) caused only a small increase in susceptibility to the most promising RPV analogs.

Conclusions

The antiviral data suggested that there are RPV analogs that could be candidates for further development as NNRTIs, and one of the most promising compounds was modeled in the NNRTI binding pocket. This model can be used to explain why this compound is broadly effective against the panel of NNRTI resistance mutants.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-016-0244-2) contains supplementary material, which is available to authorized users.

Emission Projections for Long-Haul Freight Trucks and Rail in the United States through 2050

This work develops an integrated model approach for estimating emissions from long-haul freight truck and rail transport in the United States between 2010 and 2050. We connect models of macroeconomic activity, freight demand by commodity, transportation networks, and emission technology to represent different pathways of future freight emissions. Emissions of particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), and total hydrocarbon (THC) decrease by 60%-70% from 2010 to 2030, as older vehicles built to less-stringent emission standards retire. Climate policy, in the form of carbon tax that increases apparent fuel prices, causes a shift from truck to rail, resulting in a 30% reduction in fuel consumption and a 10%-28% reduction in pollutant emissions by 2050, if rail capacity is sufficient. Eliminating high-emitting conditions in the truck fleet affects air pollutants by 20% to 65%; although these estimates are highly uncertain, they indicate the importance of durability in vehicle engines and emission control systems. Future infrastructure investment will be required both to meet transport demand and to enable actions that reduce emissions of air and climate pollutants. By driving the integrated model framework with two macroeconomic scenarios, we show that the effect of carbon tax on air pollution is robust regardless of growth levels.

Impact of a person-centred dementia care training programme on hospital staff attitudes, role efficacy and perceptions of caring for people with dementia: A repeated measures study

BACKGROUND

People with dementia occupy up to one quarter of acute hospital beds. However, the quality of care delivered to this patient group is of national concern. Staff working in acute hospitals report lack of knowledge, skills and confidence in caring for people with dementia. There is limited evidence about the most effective approaches to supporting acute hospital staff to deliver more person-centred care.

OBJECTIVES

This study aimed to evaluate the efficacy of a specialist training programme for acute hospital staff regarding improving attitudes, satisfaction and feelings of caring efficacy, in provision of care to people with dementia.

DESIGN

A repeated measures design, with measures completed immediately prior to commencing training (T1), after completion of Foundation level training (T2: 4-6 weeks post-baseline), and following Intermediate level training (T3: 3-4 months post-baseline).

SETTING

One NHS Trust in the North of England, UK.

PARTICIPANTS

40 acute hospital staff working in clinical roles, the majority of whom (90%) were nurses.

METHODS

All participants received the 3.5 day Person-centred Care Training for Acute Hospitals (PCTAH) programme, comprised of two levels, Foundation (0.5 day) and Intermediate (3 days), delivered over a 3-4 months period. Staff demographics and previous exposure to dementia training were collected via a questionnaire. Staff attitudes were measured using the Approaches to Dementia Questionnaire (ADQ), satisfaction in caring for people with dementia was captured using the Staff Experiences of Working with Demented Residents questionnaire (SEWDR) and perceived caring efficacy was measured using the Caring Efficacy Scale (CES).

RESULTS

The training programme was effective in producing a significant positive change on all three outcome measures following intermediate training compared to baseline. A significant positive effect was found on the ADQ between baseline and after completion of Foundation level training, but not for either of the other measures.

CONCLUSIONS

Training acute hospital staff in Intermediate level person-centred dementia care is effective in producing significant improvements in attitudes towards and satisfaction in caring for people with dementia and feelings of caring efficacy. Foundation level training is effective in changing attitudes but does not seem to be sufficient to bring about change in satisfaction or caring efficacy.

120 Years of U.S. Residential Housing Stock and Floor Space

Residential buildings are a key driver of energy consumption and also impact transportation and land-use. Energy consumption in the residential sector accounts for one-fifth of total U.S. energy consumption and energy-related CO₂ emissions, with floor space a major driver of building energy demands. In this work a consistent, vintage-disaggregated, annual long-term series of U.S. housing stock and residential floor space for 1891–2010 is presented. An attempt was made to minimize the effects of the incompleteness and inconsistencies present in the national housing survey data. Over the 1891–2010 period, floor space increased almost tenfold, from approximately 24,700 to 235,150 million square feet, corresponding to a doubling of floor space per capita from approximately 400 to 800 square feet. While population increased five times over the period, a 50% decrease in household size contributed towards a tenfold increase in the number of housing units and floor space, while average floor space per unit remains surprisingly constant, as a result of housing retirement dynamics. In the last 30 years, however, these trends appear to be changing, as household size shows signs of leveling off, or even increasing again, while average floor space per unit has been increasing. GDP and total floor space show a remarkably constant growth trend over the period and total residential sector primary energy consumption and floor space show a similar growth trend over the last 60 years, decoupling only within the last decade.

Increased cortical synaptic activation of TrkB and downstream signaling markers in a mouse model of Down Syndrome

Down Syndrome (DS), trisomy 21, is characterized by synaptic abnormalities and cognitive deficits throughout the lifespan and with development of Alzheimer's disease (AD) neuropathology and progressive cognitive decline in adults. Synaptic abnormalities are also present in the Ts65Dn mouse model of DS, but which synapses are affected and the mechanisms underlying synaptic dysfunction are unknown. Here we show marked increases in the levels and activation status of TrkB and associated signaling proteins in cortical synapses in Ts65Dn mice. Proteomic analysis at the single synapse level of resolution using array tomography (AT) uncovered increased colocalization of activated TrkB with signaling endosome related proteins, and demonstrated increased TrkB signaling. The extent of increases in TrkB signaling differed in each of the cortical layers examined and with respect to the type of synapse, with the most marked increases seen in inhibitory synapses. These findings are evidence of markedly abnormal TrkB-mediated signaling in synapses. They raise the possibility that dysregulated TrkB signaling contributes to synaptic dysfunction and cognitive deficits in DS.

Surgical delivery of drug releasing poly(lactic-co-glycolic acid)/poly(ethylene glycol) paste with in vivo effects against glioblastoma

INTRODUCTION

The median survival of patients with glioblastoma multiforme (astrocytoma grade 4) remains less than 18 months despite radical surgery, radiotherapy and systemic chemotherapy. Surgical implantation of chemotherapy eluting wafers into the resection cavity has been shown to improve length of survival but the current licensed therapy has several drawbacks. This paper investigates in vivo efficacy of a novel drug eluting paste in glioblastoma.

METHODS

Poly(lactic-co-glycolic acid)/poly(ethylene glycol) (PLGA/PEG) self-sintering paste was loaded with the chemotherapeutic agent etoposide and delivered surgically into partially resected tumours in a flank murine glioblastoma xenograft model.

RESULTS

Surgical delivery of the paste was successful and practical, with no toxicity or surgical morbidity to the animals. The paste was retained in the tumour cavity, and preliminary results suggest a useful antitumour and antiangiogenic effect, particularly at higher doses. Bioluminescent imaging was not affected significantly by the presence of the paste in the tumour.

CONCLUSIONS

Chemotherapy loaded PLGA/PEG paste seems to be a promising technology capable of delivering active drugs into partially resected tumours. The preliminary results of this study suggest efficacy with no toxicity and will lead to larger scale efficacy studies in orthotopic glioblastoma models.

4-amino-1-hydroxy-2-oxo-1,8-naphthyridine-containing compounds having high potency against raltegravir-resistant integrase mutants of HIV-1

There are currently three HIV-1 integrase (IN) strand transfer inhibitors (INSTIs) approved by the FDA for the treatment of AIDS. However, the emergence of drug-resistant mutants emphasizes the need to develop additional agents that have improved efficacies against the existent resistant mutants. As reported herein, we modified our recently disclosed 1-hydroxy-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamides IN inhibitors to develop compounds that have improved efficacies against recombinant IN in biochemical assays. These new compounds show single-digit nanomolar antiviral potencies against HIV vectors that carry wild-type (WT) IN in a single round replication assay and have improved potency against vectors harboring the major forms of drug resistant IN mutants. These compounds also have low toxicity for cultured cells, which in several cases, results in selectivity indices (CC₅₀/EC₅₀) of greater than 10000. The compounds have the potential, with additional structural modifications, to yield clinical agents that are effective against the known strains of resistant viruses.

Case of the month: April 1998--30 year old male with perineal numbness

A 30-year-old male presented with a 2 year progressive course of bowel and bladder dysfunction, mild leg weakness and sensory abnormalities in sacral dermatomes. MRI showed an intra-axial conus medullaris lesion which was excised and identified as a ganglioglioma. The case presents the typical clinical course and histopathology of this unusual lesion which carries a favorable prognosis after gross total removal. Preoperative neurological function in such patients is highly predictive of post-operative outcome.

Rapid screening of HIV reverse transcriptase and integrase inhibitors

Although a number of anti HIV drugs have been approved, there are still problems with toxicity and drug resistance. This demonstrates a need to identify new compounds that can inhibit infection by the common drug resistant HIV-1 strains with minimal toxicity. Here we describe an efficient assay that can be used to rapidly determine the cellular cytotoxicity and efficacy of a compound against WT and mutant viral strains. The desired target cell line is seeded in a 96-well plate and, after a 24 hr incubation, serially dilutions of the compounds to be tested are added. No further manipulations are necessary for cellular cytotoxicity assays; for anti HIV assays a predetermined amount of either a WT or drug resistant HIV-1 vector that expresses luciferase is added to the cells. Cytotoxicity is measured by using an ATP dependent luminescence assay and the impact of the compounds on infectivity is measured by determining the amount of luciferase in the presence or the absence of the putative inhibitors. This screening assay takes 4 days to complete and multiple compounds can be screened in parallel. Compounds are screened in triplicate and the data are normalized to the infectivity/ATP levels in absence of target compounds. This technique provides a quick and accurate measurement of the efficacy and toxicity of potential anti HIV compounds.

Bicyclic 1-hydroxy-2-oxo-1,2-dihydropyridine-3-carboxamide-containing HIV-1 integrase inhibitors having high antiviral potency against cells harboring raltegravir-resistant integrase mutants

Integrase (IN) inhibitors are the newest class of antiretroviral agents developed for the treatment of HIV-1 infections. Merck’s Raltegravir (RAL) (October 2007) and Gilead’s Elvitegravir (EVG) (August 2012), which act as IN strand transfer inhibitors (INSTIs), were the first anti-IN drugs to be approved by the FDA. However, the virus develops resistance to both RAL and EVG, and there is extensive cross-resistance to these two drugs. New “2nd-generation” INSTIs are needed that will have greater efficacy against RAL- and EVG-resistant strains of IN. The FDA has recently approved the first second generation INSTI, GSK’s Dolutegravir (DTG) (August 2013). Our current article describes the design, synthesis, and evaluation of a series of 1,8-dihydroxy-2-oxo-1,2-dihydroquinoline-3-carboxamides, 1,4-dihydroxy-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamides, and 1-hydroxy-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamides. This resulted in the identification of noncytotoxic inhibitors that exhibited single digit nanomolar EC₅₀ values against HIV-1 vectors harboring wild-type IN in cell-based assays. Importantly, some of these new inhibitors retain greater antiviral efficacy compared to that of RAL when tested against a panel of IN mutants that included Y143R, N155H, G140S/Q148H, G118R, and E138K/Q148K.

Co-benefits of Global Greenhouse Gas Mitigation for Future Air Quality and Human Health

Actions to reduce greenhouse gas (GHG) emissions often reduce co-emitted air pollutants, bringing co-benefits for air quality and human health. Past studies^1-6 typically evaluated near-term and local co-benefits, neglecting the long-range transport of air pollutants^7-9, long-term demographic changes, and the influence of climate change on air quality^10-12. Here we simulate the co-benefits of global GHG reductions on air quality and human health using a global atmospheric model and consistent future scenarios, via two mechanisms: a) reducing co-emitted air pollutants, and b) slowing climate change and its effect on air quality. We use new relationships between chronic mortality and exposure to fine particulate matter¹³ and ozone¹⁴, global modeling methods¹⁵, and new future scenarios¹⁶. Relative to a reference scenario, global GHG mitigation avoids 0.5±0.2, 1.3±0.5, and 2.2±0.8 million premature deaths in 2030, 2050, and 2100. Global average marginal co-benefits of avoided mortality are $50-380 (ton CO₂)^-1, which exceed previous estimates, exceed marginal abatement costs in 2030 and 2050, and are within the low range of costs in 2100. East Asian co-benefits are 10-70 times the marginal cost in 2030. Air quality and health co-benefits, especially as they are mainly local and near-term, provide strong additional motivation for transitioning to a low-carbon future.

Activities, crystal structures, and molecular dynamics of dihydro-1H-isoindole derivatives, inhibitors of HIV-1 integrase

On the basis of a series of lactam and phthalimide derivatives that inhibit HIV-1 integrase, we developed a new molecule, XZ-259, with biochemical and antiviral activities comparable to raltegravir. We determined the crystal structures of XZ-259 and four other derivatives in complex with the prototype foamy virus intasome. The compounds bind at the integrase-Mg(2+)-DNA interface of the integrase active site. In biochemical and antiviral assays, XZ-259 inhibits raltegravir-resistant HIV-1 integrases harboring the Y143R mutation. Molecular modeling is also presented suggesting that XZ-259 can bind in the HIV-1 intasome with its dimethyl sulfonamide group adopting two opposite orientations. Molecular dynamics analyses of the HIV-1 intasome highlight the importance of the viral DNA in drug potency.

6,7-Dihydroxy-1-oxoisoindoline-4-sulfonamide-containing HIV-1 integrase inhibitors

Although an extensive body of scientific and patent literature exists describing the development of HIV-1 integrase (IN) inhibitors, Merck's raltegravir and Gilead's elvitegravir remain the only IN inhibitors FDA-approved for the treatment of AIDS. The emergence of raltegravir-resistant strains of HIV-1 containing mutated forms of IN underlies the need for continued efforts to enhance the efficacy of IN inhibitors against resistant mutants. We have previously described bicyclic 6,7-dihydroxyoxoisoindolin-1-ones that show good IN inhibitory potency. This report describes the effects of introducing substituents into the 4- and 5-positions of the parent 6,7-dihydroxyoxoisoindolin-1-one platform. We have developed several sulfonamide-containing analogs that enhance potency in cell-based HIV assays by more than two orders-of-magnitude and we describe several compounds that are more potent than raltegravir against the clinically relevant Y143R IN mutant.

HRP2 determines the efficiency and specificity of HIV-1 integration in LEDGF/p75 knockout cells but does not contribute to the antiviral activity of a potent LEDGF/p75-binding site integrase inhibitor

The binding of integrase (IN) to lens epithelium-derived growth factor (LEDGF)/p75 in large part determines the efficiency and specificity of HIV-1 integration. However, a significant residual preference for integration into active genes persists in Psip1 (the gene that encodes for LEDGF/p75) knockout (KO) cells. One other cellular protein, HRP2, harbors both the PWWP and IN-binding domains that are important for LEDGF/p75 co-factor function. To assess the role of HRP2 in HIV-1 integration, cells generated from Hdgfrp2 (the gene that encodes for HRP2) and Psip1/Hdgfrp2 KO mice were infected alongside matched control cells. HRP2 depleted cells supported normal infection, while disruption of Hdgfrp2 in Psip1 KO cells yielded additional defects in the efficiency and specificity of integration. These deficits were largely restored by ectopic expression of either LEDGF/p75 or HRP2. The double-KO cells nevertheless supported residual integration into genes, indicating that IN and/or other host factors contribute to integration specificity in the absence of LEDGF/p75 and HRP2. Psip1 KO significantly increased the potency of an allosteric inhibitor that binds the LEDGF/p75 binding site on IN, a result that was not significantly altered by Hdgfrp2 disruption. These findings help to rule out the host factor-IN interactions as the primary antiviral targets of LEDGF/p75-binding site IN inhibitors.

Evaluation of global onshore wind energy potential and generation costs

In this study, we develop an updated global estimate of onshore wind energy potential using reanalysis wind speed data, along with updated wind turbine technology performance, land suitability factors, cost assumptions, and explicit consideration of transmission distance in the calculation of transmission costs. We find that wind has the potential to supply a significant portion of the world energy needs, although this potential varies substantially by region and with assumptions such as on what types of land can be used to site wind farms. Total global economic wind potential under central assumptions, that is, intermediate between optimistic and pessimistic, is estimated to be approximately 119.5 petawatt hours per year (13.6 TW) at less than 9 cents/kWh. A sensitivity analysis of eight key parameters is presented. Wind potential is sensitive to a number of input parameters, particularly wind speed (varying by -70% to +450% at less than 9 cents/kWh), land suitability (by -55% to +25%), turbine density (by -60% to +80%), and cost and financing options (by -20% to +200%), many of which have important policy implications. As a result of sensitivities studied here we suggest that further research intended to inform wind supply curve development focus not purely on physical science, such as better resolved wind maps, but also on these less well-defined factors, such as land-suitability, that will also have an impact on the long-term role of wind power.

Where do hands go? An audit of sequential hand-touch events on a hospital ward

BACKGROUND

Reservoirs of pathogens could establish themselves at forgotten sites on a ward, posing a continued risk for transmission to patients via unwashed hands.

AIM

To track potential spread of organisms between surfaces and patients, and to gain a greater understanding into transmission pathways of pathogens during patient care.

METHODS

Hand-touch activities were audited covertly for 40 × 30 min sessions during summer and winter, and included hand hygiene on entry; contact with near-patient sites; patient contact; contact with clinical equipment; hand hygiene on exit; and contact with sites outside the room.

FINDINGS

There were 104 entries overall: 77 clinical staff (59 nurses; 18 doctors), 21 domestic staff, one pharmacist and five relatives. Hand-hygiene compliance among clinical staff before and after entry was 25% (38/154), with higher compliance during 20 summer periods [47%; 95% confidence interval (CI): 35.6-58.8] than during 20 winter periods (7%; 95% CI: 3.2-14.4; P < 0.0001). More than half of the staff (58%; 45/77) touched the patient. Staff were more likely to clean their hands prior to contact with a patient [odds ratio (OR): 3.44; 95% CI: 0.94-16.0); P = 0.059] and sites beside the patient (OR: 6.76; 95% CI: 1.40-65.77; P = 0.0067). Nearly half (48%; 37/77) handled patient notes and 25% touched the bed. Most frequently handled equipment inside the room were intravenous drip (30%) and blood pressure stand (13%), and computer (26%), notes trolley (23%) and telephone (21%) outside the room.

CONCLUSION

Hand-hygiene compliance remains poor during covert observation; understanding the most frequent interactions between hands and surfaces could target sites for cleaning.

Bicyclic hydroxy-1H-pyrrolopyridine-trione containing HIV-1 integrase inhibitors

HIV-1 integrase (IN) is a validated therapeutic target for the treatment of AIDS. However, the emergence of resistance to raltegravir, the sole marketed FDA-approved IN inhibitor, emphasizes the need to develop second-generation inhibitors that retain efficacy against clinically relevant IN mutants. We report herein bicyclic hydroxy-1H-pyrrolopyridine-triones as a new family of HIV-1 integrase inhibitors that were efficiently prepared using a key 'Pummerer cyclization deprotonation cycloaddition' cascade of imidosulfoxides. In in vitro HIV-1 integrase assays, the analogs showed low micromolar inhibitory potencies with selectivity for strand transfer reactions as compared with 3'-processing inhibition. A representative inhibitor (5e) retained most of its inhibitory potency against the three major raltegravir-resistant IN mutant enzymes, G140S/Q148H, Y143R, and N155H. In antiviral assays employing viral vectors coding these IN mutants, compound 5e was approximately 200- and 20-fold less affected than raltegravir against the G140S/Q148H and Y143R mutations, respectively. Against the N155H mutation, 5e was approximately 10-fold less affected than raltegravir. Thus, our new compounds represent a novel structural class that may be further developed to overcome resistance to raltegravir, particularly in the case of the G140S/Q148H mutations.

Structural and functional analyses of the second-generation integrase strand transfer inhibitor dolutegravir (S/GSK1349572)

Raltegravir (RAL) and related HIV-1 integrase (IN) strand transfer inhibitors (INSTIs) efficiently block viral replication in vitro and suppress viremia in patients. These small molecules bind to the IN active site, causing it to disengage from the deoxyadenosine at the 3' end of viral DNA. The emergence of viral strains that are highly resistant to RAL underscores the pressing need to develop INSTIs with improved resistance profiles. Herein, we show that the candidate second-generation drug dolutegravir (DTG, S/GSK1349572) effectively inhibits a panel of HIV-1 IN variants resistant to first-generation INSTIs. To elucidate the structural basis for the increased potency of DTG against RAL-resistant INs, we determined crystal structures of wild-type and mutant prototype foamy virus intasomes bound to this compound. The overall IN binding mode of DTG is strikingly similar to that of the tricyclic hydroxypyrrole MK-2048. Both second-generation INSTIs occupy almost the same physical space within the IN active site and make contacts with the β4-α2 loop of the catalytic core domain. The extended linker region connecting the metal chelating core and the halobenzyl group of DTG allows it to enter farther into the pocket vacated by the displaced viral DNA base and to make more intimate contacts with viral DNA, compared with those made by RAL and other INSTIs. In addition, our structures suggest that DTG has the ability to subtly readjust its position and conformation in response to structural changes in the active sites of RAL-resistant INs.

Determination of the magnetic contribution to the heat capacity of cobalt oxide nanoparticles and the thermodynamic properties of the hydration layers

We present low temperature (11 K) inelastic neutron scattering (INS) data on four hydrated nanoparticle systems: 10 nm CoO·0.10H(2)O (1), 16 nm Co(3)O(4)·0.40H(2)O (2), 25 nm Co(3)O(4)·0.30H(2)O (3) and 40 nm Co(3)O(4)·0.026H(2)O (4). The vibrational densities of states were obtained for all samples and from these the isochoric heat capacity and vibrational energy for the hydration layers confined to the surfaces of these nanoparticle systems have been elucidated. The results show that water on the surface of CoO nanoparticles is more tightly bound than water confined to the surface of Co(3)O(4), and this is reflected in the reduced heat capacity and vibrational entropy for water on CoO relative to water on Co(3)O(4) nanoparticles. This supports the trend, seen previously, for water to be more tightly bound in materials with higher surface energies. The INS spectra for the antiferromagnetic Co(3)O(4) particles (2-4) also show sharp and intense magnetic excitation peaks at 5 meV, and from this the magnetic contribution to the heat capacity of Co(3)O(4) nanoparticles has been calculated; this represents the first example of use of INS data for determining the magnetic contribution to the heat capacity of any magnetic nanoparticle system.

A survey of nematode control measures used by sheep farmers and of anthelmintic resistance on their farms Part 2: South Island excluding the Nelson region

Forty-three randomly selected farms located throughout South Island, excluding the Nelson region, were surveyed for anthelmintic usage and for sheep nematodes resistant to anthelmintics. Most farmers had used both benzimidazole and non-benzimidazole broad-spectrum drenches on their properties in previous years. Sheep were being drenched, on average, 5.6 times within their first year of life but much less frequently thereafter. Commercial interests played the dominant role in helping farmers formulate their drenching policies. On each farm 24 numbered ewe replacement lambs, born during the spring of 1980, were sampled for faeces at the beginning of the trial to provide material for egg counts and larval cultures. The lambs were weighed and divided into three groups of eight. One group received thiabendazole (TBZ) at 66 mg/kg, the second levamisole (LEV) at 8 mg/kg while the third remained untreated as controls. All were resampled 4 to 10 days later. On 32 (88%) of the 40 farms where drenching trials were successfully carried out during autumn 1981, the faecal egg count depression (FECD) following treatment with either drench was 100%. On one farm TBZ was less than 100% effective as gauged by FECD. LEV proved to be less than 100% effective on 7 farms. On one farm the FECD was less than 80%, on 2 between 90% and 95% and on 4 between 95% and 99%.

Pre-oxygenation in healthy volunteers: a comparison of the supine and 45° seated positions*

Pre-oxygenation in the seated (sitting) position has been associated with better oxygenation. This randomised, cross over study compared oxygenation in the supine position with that in the 45° seated position in 40 young, healthy volunteers. Oxygen was administered through a circle system and tight fitting facemask. Transcutaneous P(O)₂ levels were recorded at 10-s intervals from two measurement points during 4 min of oxygenation in the two positions. The mean (SD) values of 12 measurements taken between the third and fourth minute were recorded. There was no difference in the increase in tissue oxygenation when comparing the supine and seated positions (32.7 (7.3) vs 32.6 (6.7) kPa, respectively). We conclude that there is no evidence that pre-oxygenation in the 45° seated position improves tissue oxygenation in young healthy volunteers compared with the supine position.

Urine catecholamine levels as diagnostic markers for neuroblastoma in a defined population: implications for ophthalmic practice

PURPOSE

although elevated urinary catecholamine levels have been reported in 90-95% of patients with neuroblastoma, more recent studies of pediatric Horner syndrome caused by an underling neuroblastoma have reported normal values at presentation. The purpose of this population-based study is to report the percentage of cases of neuroblastoma with elevated urinary catecholamine levels at presentation and to suggest a recommended work-up for cases of idiopathic pediatric Horner syndrome.

METHODS

the medical records of all pediatric (<19 years) residents of Olmsted County, Minnesota diagnosed with neuroblastoma from 1 January 1969 through 31 December 2008 were retrospectively reviewed.

RESULTS

a total of 14 patients <19 years of age were diagnosed with neuroblastoma as residents of Olmsted County, Minnesota, during the 40-year study period. A total of 10 (71%) of the 14 cases manifested elevated urinary catecholamine metabolites at the initial presentation. Urinary vanillylmandelic acid (VMA) levels were greater than twice the upper limit of normal in eight (57%) of 14 cases, whereas homovanillic acid (HVA) levels were greater than two times the upper limit of normal in 10 (71%) of the 14 cases. Three (75%) of the four cases without significantly elevated urinary VMA or HVA levels were diagnosed with stage IV disease, whereas one (25%) had stage II neuroblastoma.

CONCLUSION

urinary catecholamine levels were significantly elevated at presentation in 10 (71%) of the 14 neuroblastoma cases during the 40-year study period, suggesting that greater emphasis be placed on performing a thorough physical examination and obtaining warranted imaging studies in cases of idiopathic pediatric Horner syndrome.

Premature mortality in refractory partial epilepsy: does surgical treatment make a difference?

BACKGROUND

Epilepsy carries an increased risk of premature death. For some people with intractable focal epilepsy, surgery offers hope for a seizure-free life. The authors aimed to see whether epilepsy surgery influenced mortality in people with intractable epilepsy.

METHODS

The authors audited survival status in two cohorts (those who had surgery and those who had presurgical assessment but did not have surgery).

RESULTS

There were 40 known deaths in the non-surgical group (3365 person years of follow-up) and 19 in the surgical group (3905 person-years of follow-up). Non-operated patients were 2.4 times (95% CI 1.4 to 4.2) as likely to die as those who had surgery. They were 4.5 times (95% CI 1.9 to 10.9) as likely to die a probable epilepsy-related death. In the surgical group, those with ongoing seizures 1 year after surgery were 4.0 (95% CI 1.2 to 13.7) times as likely to die as those who were seizure-free or who had only simple partial seizures. Time-dependent Cox analysis showed that the yearly outcome group did not significantly affect mortality (HR 1.3, 95% CI 0.9 to 1.8).

CONCLUSION

Successful epilepsy surgery was associated with a reduced risk of premature mortality, compared with those with refractory focal epilepsy who did not have surgical treatment. To some extent, the reduced mortality is likely to be conferred by inducing freedom from seizures. It is not certain whether better survival is attributable only to surgery, as treatment decisions were not randomised, and there may be inherent differences between the groups.