Characteristics of heart failure with a preserved ejection fraction in black South African patients

Background

Heart failure with a preserved ejection fraction (HFpEF) is common in the elderly (≥75 years) and associated with arterial stiffness. The mean age of HFpEF presentation is lower (40-55 years) in sub-Saharan Africa. No clinical study has been conducted on HFpEF in identifying and characterising this phenotype at a younger age, moreover in a South African black population where the risk of HFpEF is two times higher than in other ethnic groups. This study investigated the characteristics of HFpEF in a black South African population, the biochemical markers that predict HFpEF and cardiac structural changes in this HF phenotype.

Methods

Sixty-six participants with HFpEF and 213 controls were enrolled. All participants gave informed consent and completed a standardised questionnaire. Echocardiographic, anthropometric, central haemodynamic measurements, pulse wave velocity (PWV) and biomarker analysis were done.

Results

The mean age of HFpEF participants was 54.88 ± 13.51 years. Most of the participants (76 %) were between 20 and 64 years, while only 24 % were older. HFpEF participants were hypertensive, and more obese with increased incidence of alcohol consumption. PWV was increased in HFpEF (9.97 ± 2.78 m/s) when compared to participants without HFpEF (6.11 ± 2.18 m/s), p < 0.0001. There were no significant associations between central haemodynamic parameters, N-terminal pro B-type natriuretic peptide (NT-proBNP) (p = 0.9746), and galectin-3 (p = 0.2166). NT-proBNP, but not galectin-3, was associated with left ventricular hypertrophy (p = 0.0002) and left atrial diameter (p = 0.0005).

Conclusion

HFpEF in South Africa is predominant in obese young to middle-age individuals with arterial stiffness and who consume alcohol regularly. NT-proBNP could be used to diagnose HFpEF, however, should be interpreted with caution in populations with a high prevalence of obesity.

Decolonizing drug-resistant E. coli with phage and probiotics: breaking the frequency-dependent dominance of residents

Widespread antibiotic resistance in commensal bacteria creates a persistent challenge for human health. Resident drug-resistant microbes can prevent clinical interventions, colonize wounds post-surgery, pass resistance traits to pathogens or move to more harmful niches following routine interventions such as catheterization. Accelerating the removal of resistant bacteria or actively decolonizing particular lineages from hosts could therefore have a number of long-term benefits. However, removing resident bacteria via competition with probiotics, for example, poses a number of ecological challenges. Resident microbes are likely to have physiological and numerical advantages and competition based on bacteriocins or other secreted antagonists is expected to give advantages to the dominant partner, via positive frequency dependence. Since a narrow range of Escherichia coli genotypes (primarily those belonging to the clonal group ST131) cause a significant proportion of multidrug-resistant infections, this group presents a promising target for decolonization with bacteriophage, as narrow-host-range viral predation could lead to selective removal of particular genotypes. In this study we tested how a combination of an ST131-specific phage and competition from the well-known probiotic E. coli Nissle strain could displace E. coli ST131 under aerobic and anaerobic growth conditions in vitro. We showed that the addition of phage was able to break the frequency-dependent advantage of a numerically dominant ST131 isolate. Moreover, the addition of competing E. coli Nissle could improve the ability of phage to suppress ST131 by two orders of magnitude. Low-cost phage resistance evolved readily in these experiments and was not inhibited by the presence of a probiotic competitor. Nevertheless, combinations of phage and probiotic produced stable long-term suppression of ST131 over multiple transfers and under both aerobic and anaerobic growth conditions. Combinations of phage and probiotic therefore have real potential for accelerating the removal of drug-resistant commensal targets.

Evaluating an alcohol harm-reduction campaign advising drinkers of the alcohol-cancer link

INTRODUCTION

Public awareness of the alcohol-cancer link is low. Provision of this information could reduce alcohol consumption and related harms. The Spread campaign is a multi-media education campaign implemented in Western Australia to inform people about the carcinogenic properties of alcohol and associated harms. The aims of the present study were to (i) examine attitudinal and behavioural outcomes of the Spread campaign and (ii) identify demographic and drinking status factors associated with enactment of harm-reduction behaviours resulting from exposure.

METHOD

A cross sectional survey of Western Australian drinkers (consumed alcohol at least a few times in the previous 12 months, n = 760) examined campaign recognition, campaign perceptions, and behaviours resulting from campaign exposure. Chi-square analyses and a generalised linear model were used to identify demographic and alcohol-related factors associated with behavioural outcomes.

RESULTS

Around two-thirds of respondents recognised the campaign (65%), and of these, 22% reported successfully reducing how often or how much they drank due to seeing the campaign. Three quarters (73%) of all respondents considered the campaign message about the alcohol-cancer link to be believable. Respondents drinking at levels above the Australian guideline were less likely to have positive perceptions of the campaign than those complying with the guideline, but were more likely to report enacting the assessed harm-reduction behaviours as a result of campaign exposure.

DISCUSSION AND CONCLUSION

The results suggest that provision of information about the alcohol-cancer link has the potential to motivate reduced alcohol consumption. Implementing such campaigns could constitute an effective alcohol harm-reduction strategy.

The emergence of e-cigarette retail shops in a regulated tobacco control environment

ISSUE ADDRESSED

E-cigarettes are of growing concern. We aimed to determine the location and characteristics of retail shops selling e-cigarette products in Perth, Western Australia.

METHODS

Two phase study: (i) identifying all e-cigarette retailers in the Greater Capital City Statistical Area of Perth; (ii) audit at the point-of-sale to assess products, promotions and shop characteristics (n = 41).

RESULTS

Ninety-eight retailers selling e-cigarette products were identified: 43 tobacconists (44%), 21 vape shops (21% - up from one shop in 2017), 14 supermarkets (14%), 12 service stations (12%) and 8 smoke shops (8%). The most common e-cigarette product was non-nicotine e-liquid, available at 38 (93%) stores audited. Most stores sold parts of e-cigarette devices (n = 25, 61%). Front counter displays were the most frequent form of promotion (n = 40, 98%). Vape shops differed from other retailers, having bar-style layouts (n = 15, 71%), lounge areas (n = 7, 33%) and free e-liquid samples (n = 17, 89%).

CONCLUSION

The availability of e-cigarette products from retail shops and particularly vape shops is increasing. E-cigarette retailers are using traditional promotional techniques including point-of-sale displays to market their products, while vape shops are extending their appeal through bar style, lounge layouts and free trials.

IMPLICATIONS FOR PUBLIC HEALTH

Understanding the e-cigarette retail store environment is essential for identifying emergent trends, potential regulations and future research. SO WHAT?: The e-cigarette retail market in the Perth is growing, shops using traditional and new promotional techniques to market e-cigarette products. Our findings identify a need for public health surveillance, regulations and legislation.

"They're sleek, stylish and sexy:" selling e-cigarettes online

OBJECTIVE

We examined the product range, marketing strategies, access and marketing claims made by Australian and New Zealand (NZ) online e-cigarette retailers.

METHODS

Twenty Australian (n=10) and NZ (n=10) e-cigarette retail websites were identified via Google using a combination of keywords nominated by an expert panel and identified via a literature review: 'e-cigarette', 'e-cigs', 'vape', and 'vaping', combined with 'Australia', 'AU', 'New Zealand' and 'NZ' and then examined.

RESULTS

Products were extensive (disposable, pod-based, reusable, replacement parts), 95% (n=19) offered 'Starter Kits,' flavoured e-liquid (n=1,032), most containing nicotine (70%, n=14). Most retailers (85%, n=17) offered price discounts and free delivery. There were unsubstantiated health claims (80%, n=16), cessation claims (65%, n=13) and cost-benefit claims (50%, n=10) promoting e-cigarette use. Most (n=14) website age verification features simply required the purchaser to indicate they were aged 18 years.

CONCLUSIONS

Although e-cigarette regulations are different in Australia and NZ, the online product range, marketing strategies, access and marketing claims were similar and sold e-liquid containing nicotine. The health and cessation e-cigarette marketing claims were outlandish and unsubstantiated.

IMPLICATIONS FOR PUBLIC HEALTH

Most purchasing of e-cigarettes occurs online. Regulations and enforcement to limit access and stop unsubstantiated marketing claims must be a public health priority.

Rapid and specific degradation of endogenous proteins in mouse models using auxin-inducible degrons

Auxin-inducible degrons are a chemical genetic tool for targeted protein degradation and are widely used to study protein function in cultured mammalian cells. Here, we develop CRISPR-engineered mouse lines that enable rapid and highly specific degradation of tagged endogenous proteins in vivo. Most but not all cell types are competent for degradation. By combining ligand titrations with genetic crosses to generate animals with different allelic combinations, we show that degradation kinetics depend upon the dose of the tagged protein, ligand, and the E3 ligase substrate receptor TIR1. Rapid degradation of condensin I and II - two essential regulators of mitotic chromosome structure - revealed that both complexes are individually required for cell division in precursor lymphocytes, but not in their differentiated peripheral lymphocyte derivatives. This generalisable approach provides unprecedented temporal control over the dose of endogenous proteins in mouse models, with implications for studying essential biological pathways and modelling drug activity in mammalian tissues.

COVID-19 and the National Lockdown: How Food Choice and Dietary Habits Changed for Families in the United Kingdom

COVID-19 changed the way families in the UK live, with as yet uncertain impacts to food choice and dietary habits. This study sought to explore food-related experiences and changes to behavior of families with children, during the pandemic. Semi-structured one-to-one interviews with parents (n = 20) and, separately, their children (n = 22; aged 8-10 years) were conducted. An inductive thematic approach was adopted for the data analysis, and four main themes emerged: commensality; elevated place of food in the home; snacking; and food shopping. Study findings highlighted several changes: some related to increased snacking and more takeaway food; others were more favorable, including spending more time together, increased home cooking, more efficient shopping practices and reduced food waste. Overall, an elevation of the place of food within the home was apparent, alongside enhanced food literacy, and some evidence of the relocalisation of food. This study contributes to the international literature on the impact of COVID-19 and national lockdowns on family lifestyle behaviors, specifically food choice and dietary habits; further research into the longer-term effects of COVID-19 on family food practices is required.

Using the transtheoretical model of behaviour change to analyse the impact of stopping exercise: a reflection

This article is an analytical reflection of the personal health journey of a first-year nursing student that was undertaken as part of a first-year unit of study. Focusing on social, physical and psychological aspects of health, it explores the impact of the cessation of exercise on her emotional and physical health and wellbeing. This is relevant to current practice as a result of COVID-19, which reduced opportunities for exercise for many people, whether because of self-isolation and lockdown restrictions on leisure facilities or increased workload and caring responsibilities, all of which affect health and wellbeing. The article is presented in the first person, reflecting the personal analysis it captures.

Rifampicin-resistant TB: discordance between Xpert® MTB/RIF and MTBDRplus results

BACKGROUND: South Africa´s diagnostic algorithm for TB diagnosis from 2011 to 2017 employed the Xpert^® MTB/RIF assay as the initial screening test for TB diagnosis and rifampicin (RIF) susceptibility, followed by submission of a specimen for GenoType^® MTBDRplus. This study aimed to determine the concordance between the two assays in terms of RIF susceptibility and explore reasons for discordance.METHODS: This was a retrospective laboratory-based study that included all MTBDRplus results of tests performed at the Braamfontein Mycobacteriology Referral Laboratory between 1 September 2014 and 31 August 2015. The patient´s Xpert RIF result was linked with the MTBDRplus result.RESULTS: The overall concordance between RIF susceptibility results was 96.4%. There were 68 discordant RIF results. The most common reasons for discordance identified were possible false Xpert RIF-resistant results (22%), mixed infection/heteroresistance (16%), transcription errors (7%) and erroneous manual interpretation of the MTBDRplus strip (7%). Xpert RIF resistance detected using delayed hybridisation was associated with discordance.CONCLUSIONS: The overall concordance between the MTBDRplus and Xpert RIF results were very good. Management of discordance should include repeat specimens for Xpert and MTBDRplus and rpoB sequencing. All variables should then be considered before treatment regimens are altered.

Rotation of a strongly coupled dust cluster in plasma by the torque of an electron beam

A 1-mm-size cluster composed of 10 dust particles immersed in plasma is rotated by the torque of a pulsed electron beam with energy in the range 8-12 keV. The dust particles are electrically charged spheres with radius 5.9 μm and are levitated in the plasma sheath, forming a round, planar, Coulomb-coupled cluster. The electron beam irradiates the dust cluster passing slightly off its center, and sets the particles in motion by the action of the electron drag force. The total torque at 12 keV is 4.9±0.2×10^{-11} Nm at an angular speed 1.41±0.05 rad s^{-1}. The main dynamical features of the cluster such as intershell rotation and itinerancy of the dust particles inside the cluster are simulated by using a molecular dynamics code.

Management of rifampicin‐resistant TB: programme indicators and care cascade analysis in South Africa

BACKGROUND: Xpert® MTB/RIF was expected to revolutionise the management of rifampicin‐resistant TB (RR‐TB) by enabling rapid and decentralised diagnosis of rifampicin (RIF) resistance.METHODS: We performed a care cascade analysis for a cohort of RR‐TB patients managed under programmatic conditions. Cumulative incidences of time to completion of the RR‐TB care cascade steps were estimated, reasons for delay or attrition from the cascade investigated and WHO programme indicators for monitoring of RR‐TB programmes calculated.RESULTS: Of 502 patients diagnosed with RR‐TB using Xpert, 64% initiated multidrug‐resistant TB (MDR‐TB) treatment immediately, 20% after some first‐line treatment, 16% never initiated MDR‐TB treatment, mainly because of death (44%) or loss to follow‐up (26%) soon after diagnosis. A supplementary sputum sample was collected within 14 days of treatment in 58.8% of cases. Only 63% of RR‐TB cases were assessed for isoniazid resistance, and only 65% of MDR‐TB cases were evaluated for pre‐XDR‐TB (extensively drug‐resistant TB). Treatment was individualised in 57% of pre‐XDR and 68% of XDR‐TB patients. Only 8% completed the entire RR‐TB care cascade as intended.CONCLUSION: Fidelity to the RR‐TB algorithm was poor, with substantial losses at each step of the cascade, highlighting the fact that implementation of novel technologies needs to be accompanied by health system strengthening to maximise impact.

The characterization of cycad palm toxicosis and treatment effects in 130 dogs

The purpose of this retrospective study is to characterize the clinical signs, laboratory values, treatment modalities and mortality outcomes related to cycad palm toxicosis in dogs and to identify medical interventions that potentially correlate with mortality. Dogs with confirmed cycad palm ingestion were identified by reviewing medical records from two private veterinary referral centres for key terms and phrases indicative of cycad palm toxicosis. Of 130 dogs included, 107 (82.3%) presented with clinical signs. A total of 2 (1.5%) died and 14 (10.8%) were euthanized. Diarrhea, lethargy and mortality were all associated with an elevated initial alanine transaminase (ALT) concentration. Overall mortality was 12.3%, with a significantly higher proportion of dogs with an ALT concentration <125 U/L surviving compared to dogs with an elevated ALT concentration. Treatment with activated charcoal reduced the odds of death among all dogs by 82% and was even more protective among dogs with an elevated initial ALT concentration. Among dogs that had an initial platelet count performed, the presence of thrombocytopenia (<200,000/μL) was a negative prognostic indicator and was associated with a significant increase in mortality. Given the high mortality rates reported for cycad palm toxicosis, it is imperative to identify early clinical indicators of mortality as well as treatments that reduce mortality.

Interannual monsoon wind variability as a key driver of East African small pelagic fisheries

Small pelagic fisheries provide food security, livelihood support and economic stability for East African coastal communities—a region of least developed countries. Using remotely- sensed and field observations together with modelling, we address the biophysical drivers of this important resource. We show that annual variations of fisheries yield parallel those of chlorophyll-a (an index of phytoplankton biomass). While enhanced phytoplankton biomass during the Northeast monsoon is triggered by wind-driven upwelling, during the Southeast monsoon, it is driven by two current induced mechanisms: coastal “dynamic uplift” upwelling; and westward advection of nutrients. This biological response to the Southeast monsoon is greater than that to the Northeast monsoon. For years unaffected by strong El-Niño/La-Niña events, the Southeast monsoon wind strength over the south tropical Indian Ocean is the main driver of year-to-year variability. This has important implications for the predictability of fisheries yield, its response to climate change, policy and resource management.

The role of serological testing in the SARS-CoV-2 outbreak

Antibody tests for the novel coronavirus, SARS-CoV2, have been developed both as rapid diagnostic assays and for high-throughput formal serology platforms. Although these tests may be a useful adjunct to a diagnostic strategy, they have a number of limitations. Because of the antibody and viral dynamics of the coronavirus, their sensitivity can be variable, especially at early time points after symptom onset. Additional data are required on the performance of the tests in the South African population, especially with regard to development and persistence of antibody responses and whether antibodies are protective against reinfection. These tests may, however, be useful in guiding the public health response, providing data for research (including seroprevalence surveys and vaccine initiatives) and development of therapeutic strategies.

Investigation into thoracic asymmetry in ridden horses

Progressive training of horses focusses on the muscular development and flexibility to both the right and the left. However anecdotal evidence suggests that horses are not symmetrically structured through the thoracic region and this may have effects on saddle fitting and performance. The aim of this research was to determine if asymmetry exists in the thoracic musculoskeletal structure of ridden horses by analysing retrospective data of saddle fits (n=490) obtained from a saddle fitting company. A flexible wither tracer tool was used to obtain tracings of wither shape. Each tracing yielded four repeatable points (two on the left; two on the right) measured from the midline at the highest and lowest points of the withers. Descriptive assessments of shoulder, wither, and back shape, and demographic information on both horse and rider were recorded. A Wilcoxon signed-rank test compared the means of the wither shape measurements. A GLIMMIX procedure identified relationships between the wither measurements, descriptive assessments, and horse and rider demographics. The means of measurements from the wither tracer tool showed almost 60% of horses having larger measurements on the left side (P<0.0001). There was no effect of horse breed, age, sex, height or level of training on wither measurements (P>0.05). Rider age, gender, height, weight and level of training did not affect wither measurements (P>0.05). These results show that horses are asymmetric in their thoracic structure with a majority of horses larger on their left side than the right. This asymmetry may be due to genetics, environment or training and should be considered when fitting a saddle to the horse.

Kynurenine pathway metabolism and the neurobiology of treatment-resistant depression: Comparison of multiple ketamine infusions and electroconvulsive therapy

Current first-line antidepressants can take weeks or months to decrease depressive symptoms. Low dose ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, shows potential for a more rapid antidepressant effect, with efficacy also evident in previously treatment-resistant populations. However, a greater understanding of the physiological mechanisms underlying such effects is required. We assessed the potential impact of ketamine infusion on neurobiological drivers of kynurenine pathway metabolism in major depression (HPA axis hyperactivity, inflammation) in patients with treatment-resistant depression compared to gender-matched healthy controls. Furthermore, we assessed these biomarkers before and after electroconvulsive therapy (ECT), which is currently the gold standard for management of treatment-resistant depression. As previously demonstrated, treatment with ketamine and ECT was associated with improved depressive symptoms in patients. At baseline, waking cortisol output was greater in the ECT cohort, kynurenine was greater in the ketamine cohort, and kynurenic acid was lower in patients compared to healthy controls, although inflammatory markers (IL-6, IL-8, IL-10 or IFN-γ) were similar in patients and controls. Furthermore, in patients who responded to ECT, the cortisol awakening response was decreased following treatment. Despite a trend towards reduced kynurenine concentrations in those who responded to ketamine, ketamine was not associated with significant alterations in any of the biomarkers assessed.

Genome-wide association study of borderline personality disorder reveals genetic overlap with bipolar disorder, major depression and schizophrenia

Borderline personality disorder (BOR) is determined by environmental and genetic factors, and characterized by affective instability and impulsivity, diagnostic symptoms also observed in manic phases of bipolar disorder (BIP). Up to 20% of BIP patients show comorbidity with BOR. This report describes the first case-control genome-wide association study (GWAS) of BOR, performed in one of the largest BOR patient samples worldwide. The focus of our analysis was (i) to detect genes and gene sets involved in BOR and (ii) to investigate the genetic overlap with BIP. As there is considerable genetic overlap between BIP, major depression (MDD) and schizophrenia (SCZ) and a high comorbidity of BOR and MDD, we also analyzed the genetic overlap of BOR with SCZ and MDD. GWAS, gene-based tests and gene-set analyses were performed in 998 BOR patients and 1545 controls. Linkage disequilibrium score regression was used to detect the genetic overlap between BOR and these disorders. Single marker analysis revealed no significant association after correction for multiple testing. Gene-based analysis yielded two significant genes: DPYD (P=4.42 × 10-7) and PKP4 (P=8.67 × 10-7); and gene-set analysis yielded a significant finding for exocytosis (GO:0006887, PFDR=0.019; FDR, false discovery rate). Prior studies have implicated DPYD, PKP4 and exocytosis in BIP and SCZ. The most notable finding of the present study was the genetic overlap of BOR with BIP (rg=0.28 [P=2.99 × 10-3]), SCZ (rg=0.34 [P=4.37 × 10-5]) and MDD (rg=0.57 [P=1.04 × 10-3]). We believe our study is the first to demonstrate that BOR overlaps with BIP, MDD and SCZ on the genetic level. Whether this is confined to transdiagnostic clinical symptoms should be examined in future studies.

The Video Interaction Guidance approach applied to teaching communication skills in dentistry

PURPOSE

To examine dentists' views of a novel video review technique to improve communication skills in complex clinical situations.

MATERIALS AND METHODS

Dentists (n = 3) participated in a video review known as Video Interaction Guidance to encourage more attuned interactions with their patients (n = 4). Part of this process is to identify where dentists and patients reacted positively and effectively. Each dentist was presented with short segments of video footage taken during an appointment with a patient with intellectual disabilities and communication difficulties. Having observed their interactions with patients, dentists were asked to reflect on their communication strategies with the assistance of a trained VIG specialist.

RESULTS

Dentists reflected that their VIG session had been insightful and considered the review process as beneficial to communication skills training in dentistry. They believed that this technique could significantly improve the way dentists interact and communicate with patients. The VIG sessions increased their awareness of the communication strategies they use with their patients and were perceived as neither uncomfortable nor threatening.

DISCUSSION

The VIG session was beneficial in this exploratory investigation because the dentists could identify when their interactions were most effective. Awareness of their non-verbal communication strategies and the need to adopt these behaviours frequently were identified as key benefits of this training approach. One dentist suggested that the video review method was supportive because it was undertaken by a behavioural scientist rather than a professional counterpart.

CONCLUSION

Some evidence supports the VIG approach in this specialist area of communication skills and dental training.

The patient impact of point-of-care vs. laboratory placement of Xpert(®) MTB/RIF

BACKGROUND

The Xpert(®) MTB/RIF assay can diagnose tuberculosis (TB) rapidly and with great accuracy. The effect of Xpert placement at point of care (POC) vs. at an off-site laboratory on patient management remains unknown.

DESIGN

At a primary care clinic in Johannesburg, South Africa, we compared TB diagnosis and treatment initiation among 1861 individuals evaluated for pulmonary TB using Xpert performed either at POC or offsite.

RESULTS

When Xpert was performed at POC, a higher proportion of Xpert-positive individuals started treatment (95% vs. 87%, P = 0.047) and time to treatment initiation was shorter (median 0 vs. 5 days, P < 0.001). In contrast, among Xpert-negative TB cases, a higher proportion (87% vs. 72%, P = 0.001) started treatment when the sample was sent to the laboratory, with a shorter time to treatment (median 9 vs. 13 days, P = 0.056). While the overall proportion of presumed TB patients starting treatment was independent of Xpert placement, the proportion started based on a bacteriologically confirmed diagnosis was higher when Xpert was performed at POC (73% vs. 58%, P = 0.006).

CONCLUSIONS

Placement of Xpert at POC resulted in more Xpert-positive patients receiving treatment, but did not increase the total number of presumed TB patients starting treatment. When samples were sent to a laboratory for Xpert testing, empiric decision making increased.

Serum BDNF as a peripheral biomarker of treatment-resistant depression and the rapid antidepressant response: A comparison of ketamine and ECT

BACKGROUND

Ketamine is associated with rapid antidepressant efficacy but the biological mechanisms underpinning this effect are unclear. Serum brain-derived neurotrophic factor (sBDNF) is a potential circulating biomarker of treatment-resistant depression (TRD) and ketamine response but it is unclear if this is a common target of both ketamine and electroconvulsive therapy (ECT), the current gold standard for TRD. Moreover, the impact of multiple ketamine infusions on sBDNF has not yet been established.

METHODS

Thirty five TRD patients with a current DSM-IV diagnosis of recurrent depressive disorder received up to 12 ECT sessions (N=17) or up to three intravenous infusions of low-dose (0.5mg/kg) ketamine (N=18). Blood samples were taken over the course of the study for assessment of sBDNF. Symptom severity and response were monitored using the 17-item Hamilton Depression Rating Scale (HDRS). sBDNF was assessed in 20 healthy controls to allow comparison with TRD patients.

RESULTS

As expected, sBDNF was lower in TRD patients at baseline compared to healthy controls. Ketamine and ECT treatment were both associated with significant reductions in depressive symptoms. However, sBDNF was significantly elevated only at one week following the first ketamine infusion in those classified as responders one week later. sBDNF was not elevated following subsequent infusions. ECT reduced depressive symptoms, as expected, but was not associated with an enhancement in BDNF.

LIMITATIONS

Patients continued with their psychotropic medications throughout this trial.

CONCLUSIONS

SBDNF normalisation does not appear to be a prerequisite for symptomatic improvement in TRD following ketamine or ECT treatment.

Necrotizing Enteritis and Hyperammonemic Encephalopathy Associated With Equine Coronavirus Infection in Equids

Equine coronavirus (ECoV) is a Betacoronavirus recently associated clinically and epidemiologically with emerging outbreaks of pyrogenic, enteric, and/or neurologic disease in horses in the United States, Japan, and Europe. We describe the pathologic, immunohistochemical, ultrastructural, and molecular findings in 2 horses and 1 donkey that succumbed to natural infection with ECoV. One horse and the donkey (case Nos. 1, 3) had severe diffuse necrotizing enteritis with marked villous attenuation, epithelial cell necrosis at the tips of the villi, neutrophilic and fibrinous extravasation into the small intestinal lumen (pseudomembrane formation), as well as crypt necrosis, microthrombosis, and hemorrhage. The other horse (case No. 2) had hyperammonemic encephalopathy with Alzheimer type II astrocytosis throughout the cerebral cortex. ECoV was detected by quantitative polymerase chain reaction in small intestinal tissue, contents, and/or feces, and coronavirus antigen was detected by immunohistochemistry in the small intestine in all cases. Coronavirus-like particles characterized by spherical, moderately electron lucent, enveloped virions with distinct peplomer-like structures projecting from the surface were detected by negatively stained transmission electron microscopy in small intestine in case No. 1, and transmission electron microscopy of fixed small intestinal tissue from the same case revealed similar 85- to 100-nm intracytoplasmic particles located in vacuoles and free in the cytoplasm of unidentified (presumably epithelial) cells. Sequence comparison showed 97.9% to 99.0% sequence identity with the ECoV-NC99 and Tokachi09 strains. All together, these results indicate that ECoV is associated with necrotizing enteritis and hyperammonemic encephalopathy in equids.

Direct accessibility of mixed-metal (iii/ii) acid sites through the rational synthesis of porous metal carboxylates

The scalable and environmentally-friendly synthesis of mixed-metal MOFs is presented.

Successes, challenges and lessons from a novel deployment of Xpert(®) MTB/RIF at a major South African public event [Short Communication]

In a mobile deployment of Xpert(®) MTB/RIF (Xpert) at the public event for 2012 South African World TB Day, Xpert testing was offered to tuberculosis (TB) symptomatic clients from gold mining and surrounding communities. Considerations before implementation included effective TB symptom screening; safe, effective sputum collection; uninterrupted electricity supply; stringent instrument verification and provision of on-site results. Public event Xpert testing is feasible; however, the case-finding rate was very low (0.7%). We recommend exploring enhanced symptom screening algorithms to improve pre-test probability, cost-effectiveness analysis, exploring alternate electrical fail-safes and on-site data connectivity and improving management of client expectations.

Diffusive anisotropy in low-permeability Ordovician sedimentary rocks from the Michigan Basin in southwest Ontario

Diffusive anisotropy was investigated using samples from Upper Ordovician shale and argillaceous limestone from the Michigan Basin of southwest Ontario, Canada. Effective diffusion coefficients (De) were determined for iodide (I(-)) and tritiated water (HTO) tracers on paired cm-scale subsamples oriented normal (NB) and parallel to bedding (PB) prepared from preserved drill cores within one year from the date of drilling. For samples with porosity >3%, an X-ray radiography method was used with I(-) tracer for determination of De and porosity accessible to I(-) ions. A through-diffusion method with I(-) and HTO tracers was used for most siltstone and limestone samples with low-porosity (<3%). The De values range from 7.0×10(-13) to 7.7×10(-12) m(2)·s(-1) for shale, 2.1×10(-13) to 1.3×10(-12) m(2)·s(-1) for limestone, and 5.3×10(-14) to 5.6×10(-13) m(2)·s(-1) for siltstone and limestone interbeds within the Georgian Bay Formation shale. The sample-scale anisotropy ratios (De-PB:De-NB) for De values obtained using the I(-) tracer are 0.9 to 4.9, and the anisotropy ratios for the HTO tracer are in the range of 1.1 to 7.0. The influence of porosity distribution on diffusive anisotropy has been investigated using one-dimensional spatially-resolved profiles of I(-)-accessible porosity (shale only) and the use of AgNO3 for fixation of I(-) tracer in the pores, allowing for SEM visualization of I(-)-accessible pore networks. The porosity profiles at the sample scale display greatest variability in the direction normal to bedding which likely reflects sedimentary depositional processes. The SEM imaging suggests that diffusion pathways are preferentially oriented parallel to bedding in the shale and that diffusion occurs dominantly within the argillaceous component of the limestone. However, the fine clay-filled intergranular voids in the dolomitic domains of the limestone are also accessible for diffusive transport.

Point-of-care Xpert® MTB/RIF for smear-negative tuberculosis suspects at a primary care clinic in South Africa

OBJECTIVE

To assess the clinical utility and cost of point-of-care Xpert® MTB/RIF for the diagnosis of smear-negative tuberculosis (TB).

DESIGN

Cohort study of smear-negative TB suspects at a South African primary care clinic. Participants provided one sputum sample for fluorescent smear microscopy and culture and an additional sample for Xpert. Outcomes of interest were TB diagnosis, linkage to care, patient and provider costs.

RESULTS

Among 199 smear-negative TB suspects, 16 were positive by Xpert, 15 by culture and 7 by microscopy. All cases identified by Xpert began anti-tuberculosis treatment the same or next day; only one of five Xpert-negative culture-positive cases started treatment after 34 days. Xpert at point of care offered similar diagnostic yield but a faster turnaround time than smear and culture performed at a centralized laboratory. Compared to smear plus culture, Xpert (at US$9.98 per cartridge) was US$3 less expensive per valid result (US$21 vs. US$24) and only US$6 more costly per case identified (US$266 vs. US$260).

CONCLUSION

Xpert is an effective method of diagnosing smear-negative TB. It is cost saving for patients, especially if performed at point of care, but it is costly for health care providers. Data-driven studies are needed to determine its cost-effectiveness in resource-poor settings with diverse diagnostic practices.

Diagnostic accuracy and effectiveness of the Xpert MTB/RIF assay for the diagnosis of HIV-associated lymph node tuberculosis

Xpert MTB/RIF (Xpert) is recommended for human immunodeficiency virus (HIV)-associated pulmonary tuberculosis but not extrapulmonary tuberculosis. We assessed the performance of Xpert for HIV-associated lymph node tuberculosis (LNTB), the most common type of extrapulmonary tuberculosis. Among HIV-infected adults suspected of LNTB presenting for fine needle aspirate (FNA) at a South African hospital, we assessed the diagnostic accuracy of Xpert using either FNA culture or a composite of microscopy, culture, and cytology as the reference standard, and evaluated the impact of different diagnostics on patient management. Among 344 adults with valid FNA culture and Xpert results, 84 (24 %) were positive on microscopy, 149 (43 %) on culture, 152 (53 %) on Xpert, and 181 (57 %) had a cytology result suggestive of tuberculosis. Using liquid culture as the reference standard, the specificity of a single Xpert was suboptimal (88.2 %) but the sensitivity was high [93.3 %, 95 % confidence interval (CI) 87.6-96.6] and increased with decreasing CD4 count (from 87.0 % for CD4 >250 to 98.6 % for CD4 <100 cells/mm(3)). Using a composite reference standard reduced the sensitivity to 79.2 % but increased the specificity to 98.6 %. All Xpert-positive patients initiated treatment within one day, compared to 70 % of culture-positive but Xpert-negative and 13 % of culture- and Xpert-negative but cytology-positive patients. Xpert is accurate and effective and could be endorsed as the initial diagnostic for HIV-associated LNTB.

A phase II study of the potent PARP inhibitor, Rucaparib (PF-01367338, AG014699), with temozolomide in patients with metastatic melanoma demonstrating evidence of chemopotentiation

PURPOSE

poly(ADP ribose) polymerase inhibition has been shown to potentiate the cytotoxicity of DNA damaging agents. A phase I study of rucaparib and temozolomide showed that full-dose temozolomide could be given during PARP inhibition. We report the results of a phase II study of intravenous rucaparib 12 mg/m(2) and oral temozolomide 200 mg/m(2) on days 1-5 every 28 days in patients with advanced metastatic melanoma.

METHODS

Patients with chemotherapy naïve measurable metastatic melanoma, performance status ≤2 and good end-organ function were recruited. Treatment was given until progression. A two stage phase II design was used, with response rate the primary endpoint. Population pharmacokinetics and pharmacodynamics were also explored.

RESULTS

Forty-six patients were recruited with 37 patients receiving at least 2 cycles and 17 patients at least 6 cycles. Myelosuppression occurred with 25 patients (54 %) requiring a 25 % dose reduction in temozolomide. The response rate was 17.4 %, median time to progression 3.5 months, median overall survival 9.9 months, and 36 % of patients were progression-free at 6 months.

CONCLUSIONS

This study showed that temozolomide (150-200 mg/m(2)/day) can safely be given with a PARP inhibitory dose of rucaparib, increasing progression-free survival over historical controls in metastatic melanoma patients.

Raf kinase inhibitor protein expression combined with peritoneal involvement and lymphovascular invasion predicts prognosis in Dukes' B colorectal cancer patients

AIMS

There is controversy regarding the use of adjuvant therapy in patients with Dukes' B colorectal cancer (CRC). New markers, identifying high-risk Dukes' B patients, are needed. Here, we examine the utility of Raf kinase inhibitor protein (RKIP) as such a marker and promoter methylation as a mechanism of RKIP down-regulation.

METHODS AND RESULTS

We used a tissue microarray of 220 patients with Dukes' B CRC to examine the effect of RKIP expression on survival. Pyrosequencing was used to assess RKIP promoter methylation status.RKIP expression correlated inversely with disease-specific survival in this cohort. In multivariate analysis, RKIP was found to be an independent prognostic indicator, along with peritoneal invasion and lymphovascular invasion (LVI). RKIP promoter hypermethylation was seen in only one of 29 tumours analysed by pyrosequencing.

CONCLUSIONS

Raf kinase inhibitor protein, peritoneal invasion and LVI provide independent prognostic information in this cohort of Dukes' B CRC patients.This demonstrates the potential utility of RKIP in identifying 'high-risk' Dukes' B patients. It is this high-risk group which is most likely to benefit from close postoperative monitoring and may derive the most benefit from adjuvant therapy.