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J Alasdair MillarMedical Department, Albany Regional Hospital, Albany, Western Australia, AustraliaBackground: The aim of this study was to establish the meaning of "high-risk" when the subgroup so defined by risk factor analysis is a substantial proportion of the population. This is clinically important when patients, deemed to be at high risk as a result of risk factor analysis, become eligible for a clinical intervention to decrease the risk, especially if the intervention has adverse effects. One example in clinical practice is the assessment of eligibility for medical thromboprophylaxis.Methods: Equations were derived relating risk and the proportion of the population (F) deemed to be at high risk on risk factor analysis, based on the formula for weighted average. The equations were validated for the population of medical inpatients at high- or low-risk of thromobembolic events using a spreadsheet model of thrombosis risk containing known risk factors for venous thromboembolism in this population.Results: The validated equations define an upper limit of absolute and incremental risk (risk relative to the whole population) in the high-risk group that is a function of or equal to 1/F, respectively. The added risk in the high-risk group declines to zero as F tends to 1, because it must be balanced by the diminishing risk in the progressively smaller low-risk group while maintaining the population average.Conclusion: The results of this study have implications for the validity of the published eligibility criteria for medical thromboprophylaxis.Keywords: population risk, relative risk, risk factors, subgroups, thromboprophylaxis

There may be bugs, there may be viruses, but computers are here to stay. Access to computers may vary greatly from 'seen one once' to daily usage. However, with an increasing dependence on electronic records, even the most remote therapist will ultimately be faced with computerization. To make this process as painless as possible some commonality in approach is logical. A common vocabulary, for instance, would ensure that dysphasia in Cape Town is the same as dysphasia in Dundee. This is great in theory but is Clinical Terms Version 3 (Read Codes) (CTV3) sufficient to encode records in clinical practice? It is to this end that the Speech and Language Therapy Department at Burton Hospital took part in a multidisciplinary project with the NHS Centre for Coding and Classification (NHS CCC). (NHS CCC became the NHS Information Authority, Coding and Classification on 1 April 1999.) Their CTV3 offers a standardized clinical terminology. An audit of patient case-notes found that 78% of the terms used by therapists were available in CTV3. Although there are many issues raised concerning electronic patient records, CTV3 presented as a potential vocabulary for recording patient information in this acute setting. [ABSTRACT FROM AUTHOR]

Amiloride (75 mg daily) and spironolactone (300 mg daily) were given to five normal subjects for 7 days in order to compare metabolic effects at maximal doses. Blood pressure, body weight, Na+ and K+ balance, and plasma concentrations of Na+, K+, active and total renin, angiotensin II, aldosterone, 11-deoxycorticosterone (DOC), 18- hydroxydeoxycorticosterone (18-OH DOC), corticosterone (B), 18- hydroxycorticosterone (18-OH B) and cortisol were measured before and on each day of treatment. Natriuresis and K+ retention were significantly greater with amiloride. Plasma K+ increased from 4.1 +/- 0.2 to 4.9 +/- 0.2 mmol/l (mean +/- s.d.) on amiloride and from 4.0 +/- 0.2 to 4.4 +/- 0.2 mmol/l with spironolactone. Stimulation of renin, angiotensin II, aldosterone and 18-OH B occurred with both drugs but was greater with amiloride in each case. A transient decrease in systolic and diastolic blood pressure was observed after 2 days of spironolactone treatment but not with amiloride. The slope of the regression of aldosterone on angiotensin II during spironolactone treatment was less than that with amiloride, consistent with partial blockade of aldosterone synthesis by spironolactone. These data suggest that the maximum metabolic effects of amiloride exceed those of spironolactone. [ABSTRACT FROM AUTHOR]

The fall in blood pressure produced by captopril is not accompanied by a compensatory tachycardia. Angiotensin converting enzyme may participate in the metabolism of endogenous opioids and these substances can lower blood pressure without reflex tachycardia. It is therefore possible that the hypotensive effect of captopril involves an action on endogenous opioid metabolism. The influence of naloxone, an opiate receptor antagonist, on the cardiovascular effects of captopril has been studied in nine normal volunteers. Mean blood pressure following a 70 degrees head up tilt 1.5 h after captopril was significantly lower than following placebo, but the blood pressure following the combination of captopril and naloxone differed from neither the placebo nor the captopril values. Blood pressures (mm Hg) were: placebo 97.7 +/- 5.9; captopril 83.3 +/- 14.2; captopril + naloxone 89.6 +/- 11.8. Heart rate (beats/min) following a 70 degrees head up tilt at 1.5 h was the same on all three treatments: placebo 83.4 +/- 21.1; captopril 83.3 +/- 16.5; captopril + naloxone 83.6 +/- 11.8. Maximum systolic blood pressure achieved during isometric exercise following captopril + naloxone was intermediate between, and did not differ significantly from, pressures obtained on the other two treatment days. We conclude that co-administration of naloxone may attenuate the effect of captopril on blood pressure and that endogenous opioids could be involved in the actions of this drug. [ABSTRACT FROM AUTHOR]

1 The effects of labetalol, bethanidine and combined treatment with both drugs were compared in a within-patient randomized cross-over study in mild essential hypertension. Attention was directed to whether or not labetalol and bethanidine differed in their pattern of effect on arterial BP and whether evidence of synergism was apparent. 2 At the doses used labetalol significantly lowered systolic and diastolic BPs and heart rate lying, sitting, standing and after exercise. The dose of bethanidine used did not affect heart rate significantly while lowering systolic and diastolic BPs only after exercise and less clearly on standing. Combined treatment lowered BPs on standing and after exercise and heart rate after exercise. 3 The type and frequency of side-effects were similar with bethanidine and labetalol but were much less with combined treatment. 4 No evidence of synergism was observed. [ABSTRACT FROM AUTHOR]

1 Prolonged infusion (11 h) of both saralasin and angiotensin- converting enzyme inhibitor (SQ20881) gradually lowered BP in two- kidney hypertensive rats to levels similar to that in normotensive rats infused with dextrose. 2 Saralasin did not lower BP in DOCA-salt hypertensive rats. 3 These observations support the notion that in chronic renal hypertension, angiotensin II may maintain hypertension by a slowly developing action. 4 Plasma angiotensin II in rats infused with SQ20881 was suppressed relative to renin, but was not eliminated. 5 Chromatography of angiotensin II extracts from dogs infused with converting enzyme inhibitor (SQ14,225) showed that the very high levels of angiotensin I achieved after treatment with SQ14,225 can lead to falsely high estimated angiotensin II levels as a result of angiotensin I cross-reacting with the angiotensin II assay. [ABSTRACT FROM AUTHOR]

Background: Farmworkers in the United States, especially migrant workers, face unique barriers to healthcare and have documented disparities in health outcomes. Exposure to pesticides, especially those persistent in the environment, may contribute to these health disparities., Objective: Quantify differences in pesticide exposure bioactivity by farmworker category and US citizenship status., Methods: We queried the National Health and Nutrition Examination Study (NHANES) from 1999-2014 for pesticide exposure biomarker concentrations among farmworkers and non-farmworkers by citizenship status. We combined this with toxicity assay data from the US Environmental Protection Agency's (EPA's) Toxicity Forecaster (ToxCast). We estimated adverse biological effects that occur across a range of human population-relevant pesticide doses., Results: In total, there were 844 people with any farmwork history and 23,592 non-farmworkers. Of 12 commonly detectable pesticide biomarkers in NHANES, 2,4-dichlorophenoxyacetic acid (OR = 3.76, p = 1.33 × 10 -6 ) was significantly higher in farmworkers than non-farmworkers. Farmworkers were 1.15 times more likely to have a bioactive pesticide biomarker measurement in comparison to non-farmworkers (adjusted OR = 1.15, 95% CI: 0.87, 1.51). Non-U.S. citizens were 1.39 times more likely to have bioactive pesticide biomarker concentrations compared to people with U.S. citizenship (adjusted OR 1.39, 95% CI: 1.17, 1.64). Additionally, non-citizens were significantly more exposed to bioactive levels of β-hexachlorocyclohexane (BHC) (OR = 8.10, p = 1.33 × 10 -6 ), p,p-DDE (OR = 2.60, p = 0.02), and p,p'-DDT (OR = 7.75, p = 0.01)., Impact Statement: Farmworkers are a vulnerable population due to social determinants of health and occupational exposures. Here, we integrate US population chemical biomonitoring data and toxicity outcome data to assess pesticide exposure by farmwork history and citizenship. We find that farmworkers and those without US citizenship are significantly more likely to be exposed to concentrations of pesticides which are bioactive in toxicological assays. Thus, farmworkers employed in the US but who are not citizens could be at increased risk of harm to their health due to pesticides. These findings are important to shape evidence-based policies in regulatory science to promote worker safety., (© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.)

The ongoing COVID-19 pandemic is causing significant morbidity and mortality across the US. In this ecological study, we identified county-level variables associated with the COVID-19 case-fatality rate (CFR) using publicly available datasets and a negative binomial generalized linear model. Variables associated with decreased CFR included a greater number of hospitals per 10,000 people, banning religious gatherings, a higher percentage of people living in mobile homes, and a higher percentage of uninsured people. Variables associated with increased CFR included a higher percentage of the population over age 65, a higher percentage of Black or African Americans, a higher asthma prevalence, and a greater number of hospitals in a county. By identifying factors that are associated with COVID-19 CFR in US counties, we hope to help officials target public health interventions and healthcare resources to locations that are at increased risk of COVID-19 fatalities., Competing Interests: The authors have declared that no competing interests exist.

Computational and mathematical models in biology rely heavily on the parameters that characterize them. However, robust estimates for their values are typically elusive and thus a large parameter space becomes necessary for model study, particularly to make translationally impactful predictions. Sampling schemes exploring parameter spaces for models are used for a variety of purposes in systems biology, including model calibration and sensitivity analysis. Typically, random sampling is used; however, when models have a high number of unknown parameters or the models are highly complex, computational cost becomes an important factor. This issue can be reduced through the use of efficient sampling schemes such as Latin hypercube sampling (LHS) and Sobol sequences. In this work, we compare and contrast three sampling schemes - random sampling, LHS, and Sobol sequences - for the purposes of performing both parameter sensitivity analysis and model calibration. In addition, we apply these analyses to different types of computational and mathematical models of varying complexity: a simple ODE model, a complex ODE model, and an agent-based model. In general, the sampling scheme had little effect when used for calibration efforts, but when applied to sensitivity analyses, Sobol sequences exhibited faster convergence. While the observed benefit to convergence is relatively small, Sobol sequences are computationally less expensive to compute than LHS samples and also have the benefit of being deterministic, which allows for better reproducibility of results., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Abnormally increased angiotensin II activity related to maternal angiotensinogen (AGT) genetic variants, or aberrant receptor activation, is associated with small-for-gestational-age babies and abnormal uterine spiral artery remodeling in humans. Our group studies a murine AGT gene titration transgenic (TG; 3-copies of the AGT gene) model, which has a 20% increase in AGT expression mimicking a common human AGT genetic variant (A[-6]G) associated with intrauterine growth restriction (IUGR) and spiral artery pathology. We hypothesized that aberrant maternal AGT expression impacts pregnancy-induced uterine spiral artery angiogenesis in this mouse model leading to IUGR. We controlled for fetal sex and fetal genotype (e.g., only 2-copy wild-type [WT] progeny from WT and TG dams were included). Uteroplacental samples from WT and TG dams from early (days 6.5 and 8.5), mid (d12.5), and late (d16.5) gestation were studied to assess uterine natural killer (uNK) cell phenotypes, decidual metrial triangle angiogenic factors, placental growth and capillary density, placental transcriptomics, and placental nutrient transport. Spiral artery architecture was evaluated at day 16.5 by contrast-perfused three-dimensional microcomputed tomography (3D microCT). Our results suggest that uteroplacental angiogenesis is significantly reduced in TG dams at day 16.5. Males from TG dams are associated with significantly reduced uteroplacental angiogenesis from early to late gestation compared with their female littermates and WT controls. Angiogenesis was not different between fetal sexes from WT dams. We conclude that male fetal sex compounds the pathologic impact of maternal genotype in this mouse model of growth restriction., (© The Author(s) 2021. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Regulatory RNAs contribute to gene expression control in bacteria. Antisense RNAs (asRNA) are a class of regulatory RNAs that are transcribed from opposite strands of their target genes. Typically, these untranslated transcripts bind to cognate mRNAs and rapidly regulate gene expression at the post-transcriptional level. In this article, we review asRNAs that modulate bacterial fitness and increase virulence. We chose examples that underscore the variety observed in nature including, plasmid- and chromosome-encoded asRNAs, a riboswitch-regulated asRNA, and asRNAs that require other RNAs or RNA-binding proteins for stability and activity. We explore how asRNAs improve bacterial fitness and virulence by modulating plasmid acquisition and maintenance, regulating transposon mobility, increasing resistance against bacteriophages, controlling flagellar production, and regulating nutrient acquisition. We conclude with a brief discussion on how this knowledge is helping to inform current efforts to develop new therapeutics., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Millar and Raghavan.)

Tuberculosis (TB) is a worldwide health problem; successful interventions such as vaccines and treatment require a 2better understanding of the immune response to infection with Mycobacterium tuberculosis (Mtb). In many infectious diseases, pathogen-specific T cells that are recruited to infection sites are highly responsive and clear infection. Yet in the case of infection with Mtb, most individuals are unable to clear infection leading to either an asymptomatically controlled latent infection (the majority) or active disease (roughly 5%-10% of infections). The hallmark of Mtb infection is the recruitment of immune cells to lungs leading to development of multiple lung granulomas. Non-human primate models of TB indicate that on average <10% of T cells within granulomas are Mtb-responsive in terms of cytokine production. The reason for this reduced responsiveness is unknown and it may be at the core of why humans typically are unable to clear Mtb infection. There are a number of hypotheses as to why this reduced responsiveness may occur, including T cell exhaustion, direct downregulation of antigen presentation by Mtb within infected macrophages, the spatial organization of the granuloma itself, and/or recruitment of non-Mtb-specific T cells to lungs. We use a systems biology approach pairing data and modeling to dissect three of these hypotheses. We find that the structural organization of granulomas as well as recruitment of non-specific T cells likely contribute to reduced responsiveness., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Millar, Butler, Evans, Mattila, Linderman, Flynn and Kirschner.)

In the wake of COVID-19, there is an urgent need for a diverse public health work force to address problems presented or exacerbated by the global pandemic. Educational programs that create our work force both train and shape the makeup of access through graduate applications. The Graduate Record Exam has a number of standing issues, with additional barriers created by the pandemic. We trace the GRE waiver movement over several years, focusing on the gradual adoption in CEPH accredited programs and the rapid expansion of temporary waivers as a response to testing access. Going forward, we need to consider gaps in waivers during the pandemic and how this data can be used to shape our future use of the GRE., (Copyright © 2020 Millar.)

Background: Vancomycin-resistant Enterococcus (VRE) is a leading cause of healthcare-associated infections, and asymptomatic colonization precedes infection. VRE continues to spread despite widespread application of pathogen-specific control guidelines. A better understanding of the risk factors for transmission is needed., Methods: A retrospective matched case-control study was performed from June 2013 through December 2016 in a single institution. Patients in 6 intensive care units, 1 hematology and oncology unit, and 1 bone marrow transplant unit were screened by means of rectal swab sampling on admission and weekly thereafter. Case patients had a negative swab sample followed by a positive sample >3 days after admission. Controls were closely matched to case patients based on time from admission to the second swab sample, unit in which the second sample was obtained, and date of admission. Comorbidity data, procedures, healthcare settings and exposures, culture data, and duration of antibiotic and proton pump inhibitor (PPI) therapy were abstracted from the electronic medical record. A multivariable risk factor model for conversion was generated using purposeful selection., Results: A total of 551 case patients were matched with controls. The largest modifiable effects on VRE acquisition were ≥1 day of vancomycin therapy (odd ratio, 1.98; P < .001), ≥1 day of aerobic antibiotic therapy (1.90; P < .001), and a dose-dependent effect of PPI therapy (odds ratio per day of therapy, 1.09; P < .001). Colonization pressures from patients identified to be carriers and placed in contact precautions did not confer increased risk., Conclusions: Decreasing PPI use and preventing the inappropriate initiation of antibiotic therapy are modifiable targets to decrease VRE transmission in the hospital.

Aims: Teriflunomide, used globally to treat multiple sclerosis (MS) and widely subsidised for this indication including in Australia and New Zealand, is the main metabolite of leflunomide, an older immune-modulating drug. Leflunomide therefore represents a potential alternative therapy for MS. Teriflunomide is about 50-500 times more expensive than leflunomide, depending on prices in each jurisdiction. I wished to study how this situation arose., Methods: Web search to obtain the publicly available minutes of eight international regulatory bodies that have approved teriflunomide for the governments of the US, Canada, Europe, England, Scotland, Australia (TGA and PBS) and New Zealand, and examination of the processes and minuted discussions concerning the metabolic, efficacy, toxicity and cost relationship between teriflunomide and leflunomide., Results: The relationship between the two drugs and their relative efficacy or toxicity in MS was considered by three of eight agencies (Food and Drug Administration (FDA), European Medicines Agency (EMA) and the Canadian Agency for Drugs and Technology in Health (CADTH)). The remaining agencies accepted teriflunomide applications at face value, assessed cost-effectiveness against contemporaneous drugs used for treating MS, and did not discuss the potential role of leflunomide as a therapy for MS. No agency minuted the implications of the cost difference., Conclusions: Efficacy for leflunomide in MS is likely but unproven. The sponsor presented a case for teriflunomide that was within the established procedures for drug agencies in establishing cost-effectiveness, and agencies did not stray from their normal procedures. As a result, an opportunity to decrease the cost of treating MS has been missed. Though off-label use of leflunomide is possible, this is unlikely without a publicly-funded trial to demonstrate non-inferiority with regard to efficacy and safety., Competing Interests: Nil.

The most commonly studied prokaryotic sensory signal transduction systems include the one-component systems, phosphosignaling systems, extracytoplasmic function (ECF) sigma factor systems, and the various types of second messenger systems. Recently, we described the regulatory role of two separate sensory systems in Streptococcus mutans that jointly control bacteriocin gene expression, natural competence development, as well as a cell death pathway, yet they do not function via any of the currently recognized signal transduction paradigms. These systems, which we refer to as LytTR Regulatory Systems (LRS), minimally consist of two proteins, a transcription regulator from the LytTR Family and a transmembrane protein inhibitor of this transcription regulator. Here, we provide evidence suggesting that LRS are a unique uncharacterized class of prokaryotic sensory system. LRS exist in a basal inactive state. However, when LRS membrane inhibitor proteins are inactivated, an autoregulatory positive feedback loop is triggered due to LRS regulator protein interactions with direct repeat sequences located just upstream of the -35 sequences of LRS operon promoters. Uncharacterized LRS operons are widely encoded by a vast array of Gram positive and Gram negative bacteria as well as some archaea. These operons also contain unique direct repeat sequences immediately upstream of their operon promoters indicating that positive feedback autoregulation is a globally conserved feature of LRS. Despite the surprisingly widespread occurrence of LRS operons, the only characterized examples are those of S. mutans. Therefore, the current study provides a useful roadmap to investigate LRS function in the numerous other LRS-encoding organisms., Competing Interests: The authors have declared that no competing interests exist.

[This corrects the article DOI: 10.7717/peerj.3269.].

Immune responses to pathogens are complex and not well understood in many diseases, and this is especially true for infections by persistent pathogens. One mechanism that allows for long-term control of infection while also preventing an over-zealous inflammatory response from causing extensive tissue damage is for the immune system to balance pro- and anti-inflammatory cells and signals. This balance is dynamic and the immune system responds to cues from both host and pathogen, maintaining a steady state across multiple scales through continuous feedback. Identifying the signals, cells, cytokines, and other immune response factors that mediate this balance over time has been difficult using traditional research strategies. Computational modeling studies based on data from traditional systems can identify how this balance contributes to immunity. Here we provide evidence from both experimental and mathematical/computational studies to support the concept of a dynamic balance operating during persistent and other infection scenarios. We focus mainly on tuberculosis, currently the leading cause of death due to infectious disease in the world, and also provide evidence for other infections. A better understanding of the dynamically balanced immune response can help shape treatment strategies that utilize both drugs and host-directed therapies., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Herein, we report an efficient combinatorial therapy for metastatic ovarian cancer based on siRNA-mediated suppression of DJ-1 protein combined with a low dose of cisplatin. DJ-1 protein modulates, either directly or indirectly, different oncogenic pathways that support and promote survival, growth, and invasion of ovarian cancer cells. To evaluate the potential of this novel therapy, we have engineered a cancer-targeted nanoplatform and validated that DJ-1 siRNA delivered by this nanoplatform after intraperitoneal injection efficiently downregulates the DJ-1 protein in metastatic ovarian cancer tumors and ascites. In vivo experiments revealed that DJ-1 siRNA monotherapy outperformed cisplatin alone by inhibiting tumor growth and increasing survival of mice with metastatic ovarian cancer. Finally, three cycles of siRNA-mediated DJ-1 therapy in combination with a low dose of cisplatin completely eradicated ovarian cancer tumors from the mice, and there was no cancer recurrence detected for the duration of the study, which lasted 35 weeks., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Here, we report the whole-genome sequence of Coxiella burnetii Nine Mile RSA439 (phase II, clone 4), a laboratory strain used extensively to investigate the biology of this intracellular bacterial pathogen. The genome consists of a 1.97-Mb chromosome and a 37.32-kb plasmid., (Copyright © 2017 Millar et al.)

Coxiella burnetii , the etiologic agent of acute Q fever and chronic endocarditis, has a unique biphasic life cycle, which includes a metabolically active intracellular form that occupies a large lysosome-derived acidic vacuole. C. burnetii is the only bacterium known to thrive within such an hostile intracellular niche, and this ability is fundamental to its pathogenicity; however, very little is known about genes that facilitate Coxiella 's intracellular growth. Recent studies indicate that C. burnetii evolved from a tick-associated ancestor and that the metabolic capabilities of C. burnetii are different from that of Coxiella -like bacteria found in ticks. Horizontally acquired genes that allow C. burnetii to infect and grow within mammalian cells likely facilitated the host shift; however, because of its obligate intracellular replication, C. burnetii would have lost most genes that have been rendered redundant due to the availability of metabolites within the host cell. Based on these observations, we reasoned that horizontally derived biosynthetic genes that have been retained in the reduced genome of C. burnetii are ideal candidates to begin to uncover its intracellular metabolic requirements. Our analyses identified a large number of putative foreign-origin genes in C. burnetii , including tRNA Glu 2 that is potentially required for heme biosynthesis, and genes involved in the production of lipopolysaccharide-a virulence factor, and of critical metabolites such as fatty acids and biotin. In comparison to wild-type C. burnetii , a strain that lacks tRNA Glu 2 exhibited reduced growth, indicating its importance to Coxiella 's physiology. Additionally, by using chemical agents that block heme and biotin biosyntheses, we show that these pathways are promising targets for the development of new anti- Coxiella therapies.

We explored the bacterial diversity of untreated sewage influent samples of a wastewater treatment plant in Tucson, AZ and discovered that Arcobacter cryaerophilus , an emerging human pathogen of animal origin, was the most dominant bacterium. The other highly prevalent bacteria were members of the phyla Bacteroidetes and Firmicutes, which are major constituents of human gut microbiome, indicating that bacteria of human and animal origin intermingle in sewage. By assembling a near-complete genome of A. cryaerophilus , we show that the bacterium has accumulated a large number of antibiotic resistance genes (ARGs) probably enabling it to thrive in the wastewater. We also determined that a majority of ARGs was being expressed in sewage, suggestive of trace levels of antibiotics or other stresses that could act as a selective force that amplifies multidrug resistant bacteria in municipal sewage. Because all bacteria are not eliminated even after several rounds of wastewater treatment, ARGs in sewage could affect public health due to their potential to contaminate environmental water., Competing Interests: The authors declare there are no competing interests.

Non-coding small RNAs (sRNAs) are critical to post-transcriptional gene regulation in bacteria. However, unlike for protein-coding genes, the evolutionary forces that shape sRNAs are not understood. We investigated sRNAs in enteric bacteria and discovered that recently emerged sRNAs evolve at significantly faster rates than older sRNAs. Concomitantly, younger sRNAs are expressed at significantly lower levels than older sRNAs. This process could potentially facilitate the integration of newly emerged sRNAs into bacterial regulatory networks. Furthermore, it has previously been difficult to trace the evolutionary histories of sRNAs because rapid evolution obscures their original sources. We overcame this challenge by identifying a recently evolved sRNA in Escherichia coli, which allowed us to determine that novel sRNAs could emerge from vestigial bacteriophage genes, the first known source for sRNA origination.

Plant associations with root microbes represent some of the most important symbioses on earth. While often critically promoting plant fitness, nitrogen-fixing rhizobia and arbuscular mycorrhizal fungi (AMF) also demand significant carbohydrate allocation in exchange for key nutrients. Though plants may often compensate for carbon loss, constraints may arise under light limitation when plants cannot extensively increase photosynthesis. Under such conditions, costs for maintaining symbioses may outweigh benefits, turning mutualist microbes into parasites, resulting in reduced plant growth and reproduction. In natural systems plants commonly grow with different symbionts simultaneously which again may interact with each other. This might add complexity to the responses of such multipartite relationships. We experimented with lima bean (Phaseolus lunatus), which efficiently forms associations with both types of root symbionts. We applied full light and low-light to each of four treatments of microbial inoculation. After an incubation period of 14 weeks, we quantified vegetative aboveground and belowground biomass and number and viability of seeds to determine effects of combined inoculant and light treatment on plant fitness. Under light-limited conditions, vegetative and reproductive traits were inhibited in AMF and rhizobia inoculated lima bean plants relative to controls (un-colonized plants). Strikingly, reductions in seed production were most critical in combined treatments with rhizobia x AMF. Our findings suggest microbial root symbionts create additive costs resulting in decreased plant fitness under light-limited conditions.

Background: The clinical and economic effects of medical thromboprophylaxis (MT) using low molecular weight heparin in Australia are unknown., Aim: To estimate the effects of MT in Australia., Methods: A decision tree model of MT was populated with national data for medical admissions. The Prevention of Recurrent Venous Thromboembolism (PREVENT) trial was chosen as the primary data source because its design uniquely avoided bias caused by treatment of sub-clinical events. Clinical efficacy and costs were estimated compared with no prophylaxis, assuming full compliance and according to three definitions of eligibility. Effectiveness was estimated as thrombotic events saved, mortality from bleeding or pulmonary embolus (PE), cost and $/year of life saved. Model outputs were subjected to sensitivity analysis., Results: MT decreased thrombotic events, and the numbers avoided increased as eligibility broadened (deep vein thrombosis (DVT): 2597, 2771 and 3232 at restricted, intermediate and broad eligibility; PE: 454, 484 and 565 respectively). The annual cost of no prophylaxis was $88.7 m. Costs were reduced at most restricted eligibility (-$7.9 m), but increased by $3.0 and $32.1 m at broader eligibility. PE deaths declined, but this was offset by deaths from haemorrhage, causing a net increase (158, 299 and 672 respectively). Estimates were sensitive to the incidence of venous thromboembolic event (VTE), case-fatality rates for PE and bleeds and the relative risk reduction for PE with prophylaxis., Conclusions: Under PREVENT trial conditions, MT avoids up to 3200 DVT and 565 PE events annually, but may increase mortality., (© 2016 Royal Australasian College of Physicians.)

Coxiella burnetii is a bacterium that thrives in an acidic parasitophorous vacuole (PV) derived from lysosomes. Leishmania mexicana, a eukaryote, has also independently evolved to live in a morphologically similar PV. As Coxiella and Leishmania are highly divergent organisms that cause different diseases, we reasoned that their respective infections would likely elicit distinct host responses despite producing phenotypically similar parasite-containing vacuoles. The objective of this study was to investigate, at the molecular level, the macrophage response to each pathogen. Infection of THP-1 (human monocyte/macrophage) cells with Coxiella and Leishmania elicited disparate host responses. At 5 days post-infection, when compared to uninfected cells, 1057 genes were differentially expressed (746 genes up-regulated and 311 genes down-regulated) in C. burnetii infected cells, whereas 698 genes (534 genes up-regulated and 164 genes down-regulated) were differentially expressed in L. mexicana infected cells. Interestingly, of the 1755 differentially expressed genes identified in this study, only 126 genes (~7%) are common to both infections. We also discovered that 1090 genes produced mRNA isoforms at significantly different levels under the two infection conditions, suggesting that alternate proteins encoded by the same gene might have important roles in host response to each infection. Additionally, we detected 257 micro RNAs (miRNAs) that were expressed in THP-1 cells, and identified miRNAs that were specifically expressed during Coxiella or Leishmania infections. Collectively, this study identified host mRNAs and miRNAs that were influenced by Coxiella and/or Leishmania infections, and our data indicate that although their PVs are morphologically similar, Coxiella and Leishmania have evolved different strategies that perturb distinct host processes to create and thrive within their respective intracellular niches.

Small RNAs (sRNAs) are short, transcribed regulatory elements that are typically encoded in the intergenic regions (IGRs) of bacterial genomes. Several sRNAs, first recognized in Escherichia coli, are conserved among enteric bacteria, but because of the regulatory roles of sRNAs, differences in sRNA repertoires might be responsible for features that differentiate closely related species. We scanned the E. coli MG1655 and Salmonella enterica Typhimurium genomes for nonsyntenic IGRs as a potential source of uncharacterized, species-specific sRNAs and found that genome rearrangements have reconfigured several IGRs causing the disruption and formation of sRNAs. Within an IGR that is present in E. coli but was disrupted in Salmonella by a translocation event is an sRNA that is associated with the FNR/CRP global regulators and influences E. coli biofilm formation. A Salmonella-specific sRNA evolved de novo through point mutations that generated a σ(70) promoter sequence in an IGR that arose through genome rearrangement events. The differences in the sRNA pools among bacterial species have previously been ascribed to duplication, deletion, or horizontal acquisition. Here, we show that genomic rearrangements also contribute to this process by either disrupting sRNA-containing IGRs or creating IGRs in which novel sRNAs may evolve., (© The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.)

Background: The Australian federal government has proposed an AUD $7 patient co-payment for a general practitioner (GP) consultation. One effect of the co-payment may be that patients will seek assistance at public hospital emergency departments (EDs), where currently there is no user charge., Aims: We studied the possible financial impact of patient diversion on the Western Australia (WA) health budget., Method: We constructed a spreadsheet model of changes in annual cash flows including the co-payment, GP fees for service, and rates of diversion to emergency departments with additional marginal costs for ED attendance., Results: Changes in WA cash flows are the aggregate of marginal ED costs of treating diverted patients and added expenditure in fees paid to rural doctors who also man local emergency centres. The estimated costs to WA are AUD $6.3 million, $35.9 million and $87.4 million at 1, 5, and 10 per cent diversion, respectively. Commonwealth receipts increase and expenditure on Medicare benefits declines., Conclusion: A diversion of patients from GP surgeries to ED in WA caused by the co-payment will result in increased costs to the state, which may be substantial, and will reduce net costs to the Commonwealth.

Background: Australia has two published national guidelines for general medical thromboprophylaxis (MT), but the two differ in detail and the basis for patient selection remains uncertain. Several aspects of current guidelines are controversial, as is the proposed design of a dedicated prescribing box in the National Inpatient Medication Chart., Aim: To discuss and comment on the current standing of medical thromboprophylaxis in Australia., Method: We have marshalled literature known to us from our previous published research, and have applied this knowledge to discuss shortcomings, which, in our opinion, exist in current medical thromboprophylaxis practice, and to suggest solutions., Conclusion: Australian guidelines are flawed because they are based on unsuitable evidence (incidence of subclinical thrombotic disease) and define eligibility broadly, such that about 80 per cent of patients are considered eligible. They urge that prescribers should "consider" prophylaxis without supplying an adequate basis for doing so. They do not provide grounds for assessing the balance between hazard (in the form of major bleeds) and benefit (thrombotic events avoided). Other clinical factors promoting unnecessary use of medical thromboprophylaxis include the use of age as a risk factor and proposed inclusion of a new DVT prophylaxis section in the National Inpatient Medication Chart (NIMC), which implicitly discourages non-prescription of prophylaxis.

Objectives: To measure eligibility for medical thromboprophylaxis using two Australasian guidelines - the Australia and New Zealand Working Party Guidelines [WPG] and the National Health and Medical Research Council Guidelines [NHMRCG]) - and proposed new guidelines based on risk-factor weights; and to measure the incidence of clinical venous thromboembolism (VTE) events in medical patients ("ensuing VTE")., Design, Setting and Patients: Prospective case-note audit in an acute medical ward of Southland Hospital, a regional hospital in Invercargill, New Zealand, among all 595 patients who were discharged consecutively from 21 November 2010 to 7 March 2011. Of these, 245 were excluded on clinical grounds or because they were under the care of the authors., Main Outcome Measures: The primary outcome was eligibility for prophylaxis under each guideline. Secondary outcomes included incidence of ensuing VTEs, use of thromboprophylaxis, drug acquisition costs with each guideline, and bedside practicability of a guideline based on risk-factor weights., Results: Nineteen per cent of patients were eligible under the new guidelines, compared with 80%, 88% and 36% under the WPG and two interpetations of the NHMRCG, respectively. One patient had an ensuing VTE. The new guideline had lower drug acquisition costs and was suitable for bedside use., Conclusions: Clinical VTE events are rare in medical patients, and medical VTE thromboprophylaxis needs to be more focused. The new guideline has performance characteristics th@satisfy this need.

Objectives: Our goal was to determine the diversity and abundance of Staphylococcus bacteria on different components of a public transportation system in a mid-sized US city (Portland, Oregon) and to examine the level of drug resistance in these bacteria., Methods: We collected 70 samples from 2 cm × 4 cm sections from seven different areas on buses and trains in Portland, USA, taking 10 samples from each area. We isolated a subset of 14 suspected Staphylococcus spp. colonies based on phenotype, and constructed a phylogeny from16S rRNA sequences to assist in identification. We used the Kirbye-Bauer disk diffusion method to determine resistance levels to six common antibiotics., Results: We found a range of pathogenic Staphylococcus species. The mean bacterial colony counts were 97.1 on bus and train floors, 80.1 in cloth seats, 9.5 on handrails, 8.6 on seats and armrests at bus stops, 3.8 on the underside of seats, 2.2 on windows, and 1.8 on vinyl seats per 8 cm(2) sample area. These differences were significant (p < 0.001). Of the 14 isolates sequenced, 11 were staphylococci, and of these, five were resistant to penicillin and ampicillin, while only two displayed intermediate resistance to bacitracin. All 11 isolates were sensitive to trimethoprim-sulfamethoxazole, vancomycin, and tetracycline., Conclusions: We found six different strains of Staphylococcus, and while there were varying levels of drug resistance, we did not find extensive levels of multidrug-resistant bacteria, and no S. aureus was found. We found floors and cloth seats to be areas on buses and trains that showed particularly high levels of bacteria.

In the present paper, we report an extremely rare case of a 4-year-old girl who developed a frontal lobe intracerebral abscess following adenotonsillectomy. This was diagnosed by computerised tomography at scan 21 days post-tonsillectomy when she presented with bilateral sixth nerve palsies. We believe that intracranial complications should be considered in any patient who present with headache or vomiting following tonsil surgery, especially if the patient has a spiking pyrexia.