Iteron control of oriV function in IncP-1 plasmid RK2.

Replication control of many plasmids is mediated by the balance between the positive and negative effects of Rep protein binding repeated sequences (iterons) associated with the replication origin, oriV. Negative control is thought to be mediated by dimeric Rep protein linking iterons in a process termed "handcuffing". The well-studied oriV region of RK2 contains 9 iterons arranged as a singleton (iteron 1), a group of 3 (iterons 2-4) and a group of 5 (iterons 5-9), but only iterons 5 to 9 are essential for replication. An additional iteron (iteron 10), oriented in the opposite direction, is also involved and reduces copy-number nearly two-fold. Since iterons 1 and 10 share an identical upstream hexamer (5' TTTCAT 3') it has been hypothesised that they form a TrfA-mediated loop facilitated by their inverted orientation. Here we report that contrary to the hypothesis, flipping one or other so they are in direct orientation results in marginally lower rather than higher copy-number. In addition, following mutagenesis of the hexamer upstream of iteron 10, we report that the Logo for the hexamer "upstream" of the regulatory iterons (1 to 4 and 10) differs from that of the essential iterons, suggesting functional differences in their interaction with TrfA.

Discharge destination and patient-reported outcomes after inpatient treatment for isolated lower limb fractures.

OBJECTIVES: To examine the association between discharge destination (home or inpatient rehabilitation) for adult patients treated in hospital for isolated lower limb fractures and patient-reported outcomes. DESIGN: Review of prospectively collected Victorian Orthopaedic Trauma Outcomes Registry (VOTOR) data. SETTING, PARTICIPANTS: Adults (18-64 years old) treated for isolated lower limb fractures at four Melbourne trauma hospitals that contribute data to the VOTOR, 1 March 2007 - 31 March 2016. MAIN OUTCOME MEASURES: Return to work and functional recovery (assessed with the extended Glasgow Outcomes Scale, GOS-E); propensity score analysis of association between discharge destination and outcome. RESULTS: Of 7961 eligible patients, 1432 (18%) were discharged to inpatient rehabilitation, and 6775 (85%) were followed up 12 months after their injuries. After propensity score adjustment, the odds of better functional recovery were 56% lower for patients discharged to inpatient rehabilitation than for those discharged directly home (odds ratio, 0.44; 95% CI, 0.37-0.51); for the 5057 people working before their accident, the odds of return to work were reduced by 66% (odds ratio, 0.34; 95% CI, 0.26-0.46). Propensity score analysis improved matching of the discharge destination groups, but imbalances in funding source remained for both outcome analyses, and for also for site and cause of injury in the GOS-E analysis (standardised differences, 10-16%). CONCLUSIONS: Discharge to inpatient rehabilitation after treatment for isolated lower limb fractures was associated with poorer outcomes than discharge home. Factors that remained unbalanced after propensity score analysis could be assessed in controlled trials.

Clinicians' perceptions of decision making regarding discharge from public hospitals to in-patient rehabilitation following trauma.

Objective The aim of the present study was to investigate the perceptions of consultant surgeons, allied health clinicians and rehabilitation consultants regarding discharge destination decision making from the acute hospital following trauma. Methods A qualitative study was performed using individual in-depth interviews of clinicians in Victoria (Australia) between April 2013 and September 2014. Thematic analysis was used to derive important themes. Case studies provided quantitative information to enhance the information gained via interviews. Results Thirteen rehabilitation consultants, eight consultant surgeons and 13 allied health clinicians were interviewed. Key themes that emerged included the importance of financial considerations as drivers of decision making and the perceived lack of involvement of medical staff in decisions regarding discharge destination following trauma. Other themes included the lack of consistency of factors thought to be important drivers of discharge and the difficulty in acting on trauma patients' requests in terms of discharge destination. Importantly, as the complexity of the patient increases in terms of acquired brain injury, the options for rehabilitation become scarcer. Conclusions The information gained in the present study highlights the large variation in discharge practises between and within clinical groups. Further consultation with stakeholders involved in the care of trauma patients, as well as government bodies involved in hospital funding, is needed to derive a more consistent approach to discharge destination decision making. What is known about the topic? Little is known about the drivers for referral to, or acceptance at, in-patient rehabilitation following acute hospital care for traumatic injury in Victoria, Australia, including who makes these decisions of behalf of patients and how these decisions are made. What does this paper add? This paper provides information regarding the perceptions of acute hospital consultant surgeons and allied health, as well as rehabilitation clinicians, in terms of discharge destination decision making from the acute hospital following trauma. The use of case studies further highlights differences between, and within, these specialities with regard to this decision making. This research also highlights the importance of financial considerations as drivers of decision making, and the lack of consistency of the factors thought to be important drivers of discharge between these different clinical groupings. What are the implications for practitioners? This research shows that financial factors are significant drivers of discharge destination decision making for trauma patients. The present study highlights opportunities to engage with stakeholders (acute care, rehabilitation, administration, government and patients) to develop more consistent discharge processes that optimise the use of rehabilitation resources for those patients who could benefit from in-patient rehabilitation.

Selected Mutations Reveal New Intermediates in the Biosynthesis of Mupirocin and the Thiomarinol Antibiotics.

Thiomarinol and mupirocin are assembled on similar polyketide/fatty acid backbones and exhibit potent antibiotic activity against methicillin-resistant Staphylococcus aureus (MRSA). They both contain a tetrasubstituted tetrahydropyran (THP) ring that is essential for biological activity. Mupirocin is a mixture of pseudomonic acids (PAs). Isolation of the novel compound mupirocin P, which contains a 7-hydroxy-6-keto-substituted THP, from a ΔmupP strain and chemical complementation experiments confirm that the first step in the conversion of PA-B into the major product PA-A is oxidation at the C6 position. In addition, nine novel thiomarinol (TM) derivatives with different oxidation patterns decorating the central THP core were isolated after gene deletion (tmlF). These metabolites are in accord with the THP ring formation and elaboration in thiomarinol following a similar order to that found in mupirocin biosynthesis, despite the lack of some of the equivalent genes. Novel mupirocin-thiomarinol hybrids were also synthesized by mutasynthesis.

Discharge from the acute hospital: trauma patients' perceptions of care.

Objective The involvement of orthopaedic trauma patients in the decision-making regarding discharge destination from the acute hospital and their perceptions of the care following discharge are poorly understood. The aim of the present study was to investigate orthopaedic trauma patient experiences of discharge from the acute hospital and transition back into the community. Methods The present qualitative study performed in-depth interviews, between October 2012 and November 2013, with patients aged 18-64 years with lower limb trauma. Thematic analysis was used to derive important themes. Results Ninety-four patients were interviewed, including 35 discharged to in-patient rehabilitation. Key themes that emerged include variable involvement in decision-making regarding discharge, lack of information and follow-up care on discharge and varying opinions regarding in-patient rehabilitation. Readiness for discharge from in-patient rehabilitation also differed widely among patients, with patients often reporting being ready for discharge before the planned discharge date and feeling frustration at the need to stay in in-patient care. There was also a difference in patients' perception of the factors leading to recovery, with patients discharged to rehabilitation more commonly reporting external factors, such as rehabilitation providers and physiotherapy. Conclusion The insights provided by the participants in the present study will help us improve our discharge practice, especially the need to address the concerns of inadequate information provision regarding discharge and the role of in-patient rehabilitation. What is known about the topic? There is no current literature describing trauma patient involvement in decision-making regarding discharge from the acute hospital and the perception of how this decision (and destination choice; e.g. home or in-patient rehabilitation) affects their outcome. What does this paper add? The present large qualitative study provides information on patients' opinion of discharge from the acute hospital following trauma and how this could be improved from their perception. Patients are especially concerned with the lack of information provided to them on discharge, their lack of involvement and understanding of the choices made with regard to their discharge and describe concerns regarding their follow-up care. There is also a feeling from the patients that they are ready to leave rehabilitation before their actual planned discharge date, a concept that needs further investigation. What are the implications for practitioners? The patient insights gained by the present study will lead to a change in discharge practice, including increased involvement of the patient in the decision-making in terms of discharge from both the acute and rehabilitation hospitals and a raised awareness of the need to provide written information and follow-up telephone calls to patients following discharge. Further research into many aspects of patient discharge from the acute hospital should be considered, including the use of rehabilitation prediction tools to ensure patient involvement in decision-making and a discharge and/or follow-up coordinator to ensure patients are aware of how to access information after discharge.

A conserved motif flags acyl carrier proteins for ß-branching in polyketide synthesis.

Type I polyketide synthases often use programmed ß-branching, via enzymes of a 'hydroxymethylglutaryl-CoA synthase (HCS) cassette', to incorporate various side chains at the second carbon from the terminal carboxylic acid of growing polyketide backbones. We identified a strong sequence motif in acyl carrier proteins (ACPs) where ß-branching is known to occur. Substituting ACPs confirmed a correlation of ACP type with ß-branching specificity. Although these ACPs often occur in tandem, NMR analysis of tandem ß-branching ACPs indicated no ACP-ACP synergistic effects and revealed that the conserved sequence motif forms an internal core rather than an exposed patch. Modeling and mutagenesis identified ACP helix III as a probable anchor point of the ACP-HCS complex whose position is determined by the core. Mutating the core affects ACP functionality, whereas ACP-HCS interface substitutions modulate system specificity. Our method for predicting ß-carbon branching expands the potential for engineering new polyketides and lays a basis for determining specificity rules.

Pharmacological interactions between rifampicin and antiretroviral drugs: challenges and research priorities for resource-limited settings.

Coadministration of antituberculosis and antiretroviral therapy is often inevitable in high-burden countries where tuberculosis (TB) is the most common opportunistic infection associated with HIV/AIDS. Concurrent use of rifampicin and many antiretroviral drugs is complicated by pharmacokinetic drug-drug interactions. Rifampicin is a very potent enzyme inducer, which can result in subtherapeutic antiretroviral drug concentrations. In addition, TB drugs and antiretroviral drugs have additive (pharmacodynamic) interactions as reflected in overlapping adverse effect profiles. This review provides an overview of the pharmacological interactions between rifampicin-based TB treatment and antiretroviral drugs in adults living in resource-limited settings. Major progress has been made to evaluate the interactions between TB drugs and antiretroviral therapy; however, burning questions remain concerning nevirapine and efavirenz effectiveness during rifampicin-based TB treatment, treatment options for TB-HIV-coinfected patients with nonnucleoside reverse transcriptase inhibitor resistance or intolerance, and exact treatment or dosing schedules for vulnerable patients including children and pregnant women. The current research priorities can be addressed by maximizing the use of already existing data, creating new data by conducting clinical trials and prospective observational studies and to engage a lobby to make currently unavailable drugs available to those most in need.

Biosynthesis of mupirocin by Pseudomonas fluorescens NCIMB 10586 involves parallel pathways.

Mupirocin, a clinically important antibiotic produced via a trans-AT Type I polyketide synthase (PKS) in Pseudomonas fluorescens, consists of a mixture of mainly pseudomonic acids A, B, and C. Detailed metabolic profiling of mutant strains produced by systematic inactivation of PKS and tailoring genes, along with re-feeding of isolated metabolites to mutant stains, has allowed the isolation of a large number of novel metabolites, identification of the 10,11-epoxidase, and full characterization of the mupirocin biosynthetic pathway, which proceeds via major (10,11-epoxide) and minor (10,11-alkene) parallel pathways.

Consuming a buttermilk drink containing lutein-enriched egg yolk daily for 1 year increased plasma lutein but did not affect serum lipid or lipoprotein concentrations in adults with early signs of age-related macular degeneration.

Dietary lutein intake is postulated to interfere with the development of age-related macular degeneration (AMD). Because egg yolk-derived lutein has a high bioavailability, long-term consumption of lutein-enriched eggs might be effective in preventing AMD development, but alternatively might increase cardiovascular disease risk. Here, we report the effect of 1-y daily consumption of a buttermilk drink containing 1.5 lutein-rich egg yolks on serum lipid and lipoprotein and plasma lutein concentrations. Additionally, subgroups that could potentially benefit the most from the intervention were identified. Men and women who had early signs of AMD in at least 1 eye, but were otherwise healthy, participated in a 1-y randomized, placebo-controlled parallel intervention trial. At the start of the study, 101 participants were included: 52 in the experimental (Egg) group and 49 in the control (Con) group. Final analyses were performed with 45 participants in the Egg group and 43 participants in the Con group. As expected, the increase in plasma lutein concentrations in the Egg group was 83% higher than that in the Con group (P < 0.001). Changes in serum total, HDL, and LDL cholesterol, as well as the ratio of total cholesterol to HDL cholesterol, were not different between the 2 groups. Interestingly, participants classified as cholesterol absorbers had higher serum HDL cholesterol concentrations than participants classified as cholesterol synthesizers or participants with average campesterol-to-lathosterol ratios (P < 0.05) at baseline. In addition, cholesterol absorbers had a 229% higher increase in plasma lutein concentrations than participants who were classified as having an average campesterol-to-lathosterol ratio upon consumption of the lutein-enriched egg yolk drink (P < 0.05). Moreover, the change in serum HDL cholesterol upon consumption was significantly different between these 3 groups (P < 0.05). We suggest that cholesterol absorbers particularly might benefit from the lutein-enriched buttermilk drink. This study was registered at clinicaltrials.gov as NCT00902408.

Nevirapine concentrations in saliva measured by thin layer chromatography and self-reported adherence in patients on antiretroviral therapy at Kilimanjaro Christian Medical Centre, Tanzania.

BACKGROUND: Thin layer chromatography (TLC) can be used to perform therapeutic drug monitoring in resource-limited settings, where more expensive analytical methods, such as high-performance liquid chromatography or liquid chromatography-mass spectrometry, are not feasible. OBJECTIVES: The aim of this cross-sectional study was to compare saliva concentrations of nevirapine (NVP) with self-reported adherence in patients on NVP-containing antiretroviral treatment at Kilimanjaro Christian Medical Centre, Moshi, Tanzania. METHODS: HIV-infected patients using a combination of zidovudine + lamivudine + NVP, or stavudine + lamivudine + NVP, for more than 4 weeks were included. Saliva samples were collected using dental cotton rolls impregnated with citric acid (20 mg). Saliva NVP concentrations were analyzed using TLC. Adherence to ARV medication was assessed by self-reporting using the Morisky scale. RESULTS: Of the 91 study participants, 79 (86.8%) had therapeutic saliva NVP concentrations (ie, >1.75 mg/L) and 12 (13.2%) had subtherapeutic concentrations. Self-reported adherence among the study participants was high in 62 participants (68.1%), moderate in 24 (26.4%), and low in 5 (5.5%). Fifty-seven (91.9%) of the study participants with high self-reported adherence had therapeutic saliva NVP concentrations. Of the 5 participants with low self-reported adherence, 3 had therapeutic NVP concentrations. CONCLUSIONS: A high proportion of patients had therapeutic NVP saliva concentrations as measured by TLC, which showed a good agreement with self-reported adherence.

Effect of 7 days of phenytoin on the pharmacokinetics of and the development of resistance to single-dose nevirapine for perinatal HIV prevention: a randomized pilot trial.

OBJECTIVES: To confirm whether 7 days of phenytoin, an enzyme inducer, would decrease the elimination half-life of single-dose nevirapine and to investigate its effect on the development of nevirapine resistance in pregnant, HIV-infected women. METHODS: In a pharmacokinetic pilot trial (NCT01187719), HIV-infected, antiretroviral (ARV)-naive pregnant women ≥18 years old from Zambia and Tanzania and with CD4 cell counts >350 cells/mm(3) were randomized 1 : 1 to a control (zidovudine pre-delivery, single-dose nevirapine/zidovudine/lamivudine at delivery and zidovudine/lamivudine for 7 days post-delivery) or an intervention (control plus 184 mg of phenytoin once daily for 7 days post-delivery) group. Primary endpoints were the pharmacokinetics of and resistance to nevirapine. RESULTS: Thirty-five and 37 women were allocated to the control and intervention groups, with median (IQR) ages of 27 (23-31) and 27 (23-33) years, respectively. Twenty-three and 23 women had detectable nevirapine levels at delivery and subsequent samples in the control and the intervention groups, respectively. Geometric mean (GM) (95% CI) plasma levels of nevirapine at delivery were 1.02 (0.58-1.78) mg/L and 1.14 (0.70-1.86) mg/L in the control and intervention groups, respectively (P = 0.76). One week after delivery, 0/23 (0%) and 15/22 (68%) control and intervention mothers, respectively, had undetectable levels of nevirapine (<0.05 mg/L; P<0.001). One week later, the figures were 10/21 (48%) and 18/19 (95%) mothers, respectively (P = 0.002). The GM (95% CI) half-life of nevirapine was 63.2 (52.8-75.7) versus 25.5 (21.6-30.1) h in the control group versus the intervention group (P < 0.001). New nevirapine mutations were found in 0/20 (0%) intervention-group mothers versus 1/21 (5%) control-group mothers. Overall, there was no difference in adverse events reported between the control and intervention arms (P > 0.28). CONCLUSIONS: Adding 7 days of an enzyme inducer to single-dose nevirapine to prevent mother-to-child transmission of HIV significantly reduced subtherapeutic nevirapine levels by shortening the half-life of nevirapine. As prolonged subtherapeutic nevirapine dosage leads to the emergence of resistance, single-dose nevirapine could be used with phenytoin as an alternative if other ARVs were unavailable.

Comparison of measures of comorbidity for predicting disability 12-months post-injury.

BACKGROUND: Understanding the factors that impact on disability is necessary to inform trauma care and enable adequate risk adjustment for benchmarking and monitoring. A key consideration is how to adjust for pre-existing conditions when assessing injury outcomes, and whether the inclusion of comorbidity is needed in addition to adjustment for age. This study compared different approaches to modelling the impact of comorbidity, collected as part of the routine hospital episode data, on disability outcomes following orthopaedic injury. METHODS: 12-month Glasgow Outcome Scale - Extended (GOS-E) outcomes for 13,519 survivors to discharge were drawn from the Victorian Orthopaedic Trauma Outcomes Registry, a prospective cohort study of admitted orthopaedic injury patients. ICD-10-AM comorbidity codes were mapped to four comorbidity indices. Cases with a GOS-E score of 7-8 were considered "recovered". A split dataset approach was used with cases randomly assigned to development or test datasets. Logistic regression models were fitted with "recovery" as the outcome and the performance of the models based on each comorbidity index (adjusted for injury and age) measured using calibration (Hosmer-Lemshow (H-L) statistics and calibration curves) and discrimination (Area under the Receiver Operating Characteristic (AUC)) statistics. RESULTS: All comorbidity indices improved model fit over models with age and injuries sustained alone. None of the models demonstrated acceptable model calibration (H-L statistic p < 0.05 for all models). There was little difference between the discrimination of the indices for predicting recovery: Charlson Comorbidity Index (AUC 0.70, 95% CI: 0.68, 0.71); number of ICD-10 chapters represented (AUC 0.70, 95% CI: 0.69, 0.72); number of six frequent chronic conditions represented (AUC 0.70, 95% CI: 0.69, 0.71); and the Functional Comorbidity Index (AUC 0.69, 95% CI: 0.68, 0.71). CONCLUSIONS: The presence of ICD-10 recorded comorbid conditions is an important predictor of long term functional outcome following orthopaedic injury and adjustment for comorbidity is indicated when assessing risk-adjusted functional outcomes over time or across jurisdictions.

Orthopaedic injuries due to electric scooter trauma presenting to a level 1 trauma centre before and after introduction of a scooter-sharing scheme.

Background: Epidemiological data from various jurisdictions has shown that electric scooters are associated with significant trauma. The Victorian state government introduced a trial scooter sharing scheme on February 1, 2022 in inner city Melbourne. This is a descriptive study from the largest trauma centre in Victoria, geographically at the heart of the government sharing scheme, investigating the "scope of the problem" before and after introduction of the ride sharing scheme. Methods: Retrospective case series. Insitutional orthopaedic department database was searched from 1 Jan 2021 to 30 June 2022 to identify all admissions, requiring orthopaedic management, associated with e-scooter trauma. Data collected included, alcohol/drug involvement, hospital LOS, injury severity score, ICU admission, injuries sustained, surgical procedures, discharge destination, and death. Results: In the 12 months prior to, and five months since introduction of the ride share scheme, 43 patients sustaining e-scooter related injuries were identified. Eighteen patients (42%) presented in the five months since ride sharing was introduced and 25 patients in the preceding 12 months. 58% of patients were found to be intoxicated. Fourteen percent required an ICU admission. Forty-four percent of patients were polytrauma admissions. The median length of stay was two days, longest individual hospital stay was 69 days. There were 49 surgical procedures in 35 patients including neurosurgical, plastics and maxillofacial operations. The mean Injury Severity Score was 17.28. Conclusion: Electric scooters are associated with a significant trauma burden. This data may be combined with other clinical services and could be used to inform policy makers.

High quality genome annotation and expression visualisation of a mupirocin-producing bacterium.

Pseudomonas strain NCIMB10586, in the P. fluorescens subgroup, produces the polyketide antibiotic mupirocin, and has potential as a host for industrial production of a range of valuable products. To underpin further studies on its genetics and physiology, we have used a combination of standard and atypical approaches to achieve a quality of the genome sequence and annotation, above current standards for automated pathways. Assembly of Illumina reads to a PacBio genome sequence created a retrospectively hybrid assembly, identifying and fixing 415 sequencing errors which would otherwise affect almost 5% of annotated coding regions. Our annotation pipeline combined automation based on related well-annotated genomes and stringent, partially manual, tests for functional features. The strain was close to P. synxantha and P. libaniensis and was found to be highly similar to a strain being developed as a weed-pest control agent in Canada. Since mupirocin is a secondary metabolite whose production is switched on late in exponential phase, we carried out RNAseq analysis over an 18 h growth period and have developed a method to normalise RNAseq samples as a group, rather than pair-wise. To review such data we have developed an easily interpreted way to present the expression profiles across a region, or the whole genome at a glance. At the 2-hour granularity of our time-course, the mupirocin cluster increases in expression as an essentially uniform bloc, although the mupirocin resistance gene stands out as being expressed at all the time points.

Manipulation of quorum sensing regulation in Pseudomonas fluorescens NCIMB 10586 to increase mupirocin production.

Transcription of the 74 kb Pseudomonas fluorescens mupirocin [pseudomonic acid (PA)] biosynthesis cluster depends on quorum sensing-dependent regulation via the LuxI/LuxR homologues MupI/MupR. To facilitate analysis of novel PAs from pathway mutants, we investigated factors that affect mup gene expression. First, the signal produced by MupI was identified as N-(3-oxodecanoyl)homoserine lactone, but exogenous addition of this molecule did not activate mupirocin production prematurely nor did expression of mupI in trans increase metabolite production. Second, we confirmed that mupX, encoding an amidase/hydrolase that can degrade N-acylhomoserine lactones, is also required for efficient expression, consistent with its occurrence in a regulatory module linked to unrelated genes in P. fluorescens. Third, and most significantly, mupR expression in trans to wild type and mutants can increase production of antibiotic and novel intermediates up to 17-fold.

Outcomes of severe lower limb injury with Mangled Extremity Severity Score ≥ 7.

AIMS: Complex fractures of the femur and tibia with associated severe soft tissue injury are often devastating for the individual. The aim of this study was to describe the two-year patient-reported outcomes of patients in a civilian population who sustained a complex fracture of the femur or tibia with a Mangled Extremity Severity Score (MESS) of ≥ 7, whereby the score ranges from 2 (lowest severity) to 11 (highest severity). METHODS: Patients aged ≥ 16 years with a fractured femur or tibia and a MESS of ≥ 7 were extracted from the Victorian Orthopaedic Trauma Outcomes Registry (January 2007 to December 2018). Cases were grouped into surgical amputation or limb salvage. Descriptive analysis were used to examine return to work rates, three-level EuroQol five-dimension questionnaire (EQ-5D-3L), and Glasgow Outcome Scale-Extended (GOS-E) outcomes at 12 and 24 months post-injury. RESULTS: In all, 111 patients were included: 90 (81%) patients who underwent salvage and 21 (19%) patients with surgical amputation. The mean age of patients was 45.8 years (SD 15.8), 93 (84%) were male, 37 (33%) were involved in motor vehicle collisions, and the mean MESS score was 8.2 (SD 1.4). Two-year outcomes in the cohort were poor: six (7%) patients achieved a GOS-E good recovery, the mean EQ-5D-3L summary score was 0.52 (SD 0.27), and 17 (20%) patients had returned to work. CONCLUSION: A small proportion of patients with severe lower limb injury (MESS ≥ 7) achieved a good level of function 24 months post-injury. Further follow-up is needed to better understand the long-term trajectory of these patients, including delayed amputation, hospital readmissions, and healthcare utilization. Cite this article: Bone Joint J 2021;103-B(4):769-774.

Does deprivation index modify the acute effect of black smoke on cardiorespiratory mortality?

OBJECTIVES: To investigate whether deprivation index modifies the acute effect of black smoke on cardiorespiratory mortality. METHODS: Generalised linear Poisson regression models were used to investigate whether deprivation index (as measured by the Carstairs deprivation index) modified the acute effect of black smoke on mortality in two largest Scottish cities (Glasgow and Edinburgh) between January 1981 and December 2001. Lag periods of up to 1 month were assumed for the effects of black smoke. RESULTS: Deprivation index significantly modified the effect of black smoke on mortality, with black smoke effects generally increasing as level of deprivation increased. The interaction coefficient from a parametric model assuming a linear interaction between black smoke (microg/m(-3)) and deprivation in their effect on mortality--equivalent to a test of 'linear trend' across Carstairs categories--was significant for all mortality outcomes. In a model where black smoke effects were estimated independently for each deprivation category, the estimated increase in respiratory mortality over the ensuing 1-month period associated with a 10 microg/m(3) increase in the mean black smoke concentration was 8.0% (95% CI 5.1 to 10.9) for subjects residing in the 'most' deprived category (Carstairs category 7) compared to 3.7% (95% CI -0.7 to 8.4) for subjects residing in the 'least' deprived category (Carstairs category 1). CONCLUSIONS: The results suggest a stronger effect of black smoke on mortality among people living in more deprived areas. The effect was greatest for respiratory mortality, although significant trends were also seen for other groups. If corroborated, these findings could have important public health implications.

Na(+)-K (+)-2Cl (-) cotransport inhibitor attenuates cerebral edema following experimental stroke via the perivascular pool of aquaporin-4.

INTRODUCTION: The Na(+)-K(+)-2Cl(-) cotransporter localized in the brain vascular endothelium has been shown to be important in the evolution of cerebral edema following experimental stroke. Previous in vivo studies have demonstrated that bumetanide, a selective Na(+)-K(+)-2Cl(-) cotransport inhibitor, attenuates ischemia-evoked cerebral edema. Recently, bumetanide has been shown to also inhibit water permeability via aquaporin-4 (AQP4) expressed in Xenopus laevis oocytes. We tested the hypothesis that the perivascular pool of AQP4 plays a significant role in the anti-edema effect of bumetanide by utilizing wild-type (WT) mice as well as mice with targeted disruption of alpha-syntrophin (alpha-Syn(-/-)) that lack the perivascular pool of AQP4. METHODS: Isoflurane-anesthetized adult male WT C57Bl6 and alpha-Syn(-/-) mice were subjected to 90 min middle cerebral artery occlusion (MCAO) followed by 24 or 48 h of reperfusion. Adequacy of MCAO and reperfusion was monitored with laser-Doppler flowmetry over the ipsilateral parietal cortex. Infarct volume (tetrazolium staining), cerebral edema (wet-to-dry ratios), and AQP4 protein expression (immunoblotting) were determined in different treatment groups in separate sets of experiments. RESULTS: Bumetanide significantly attenuated infarct volume and decreased ipsilateral hemispheric water content in WT mice compared to vehicle treatment. In alpha-Syn(-/-) mice, bumetanide treatment had no effect on infarct volume or ischemia-evoked cerebral edema. Bumetanide-treated WT mice had a significant attenuation of AQP4 protein expression at 48 h post-MCAO compared to vehicle-treated WT mice. CONCLUSIONS: These data suggest that bumetanide exerts its neuroprotective and anti-edema effects partly via blockade of the perivascular pool of AQP4 and may have therapeutic potential for ischemic stroke in the clinical setting.

Potentiation of curing by a broad-host-range self-transmissible vector for displacing resistance plasmids to tackle AMR.

Plasmids are potent vehicles for spread of antibiotic resistance genes in bacterial populations and often persist in the absence of selection due to efficient maintenance mechanisms. We previously constructed non-conjugative high copy number plasmid vectors that efficiently displace stable plasmids from enteric bacteria in a laboratory context by blocking their replication and neutralising their addiction systems. Here we assess a low copy number broad-host-range self-transmissible IncP-1 plasmid as a vector for such curing cassettes to displace IncF and IncK plasmids. The wild type plasmid carrying the curing cassette displaces target plasmids poorly but derivatives with deletions near the IncP-1 replication origin that elevate copy number about two-fold are efficient. Verification of this in mini IncP-1 plasmids showed that elevated copy number was not sufficient and that the parB gene, korB, that is central to its partitioning and gene control system, also needs to be included. The resulting vector can displace target plasmids from a laboratory population without selection and demonstrated activity in a mouse model although spread is less efficient and requires additional selection pressure.

Novel interventions to reduce re-infection in women with chlamydia: a randomized controlled trial.

BACKGROUND: The aim of this study was to determine whether postal testing kits (PTKs) or patient-delivered partner therapy (PDPT) for partners of women with Chlamydia trachomatis reduce re-infection rates in women, compared with partner notification by patient referral. METHODS: Three hundred and thirty women testing positive for chlamydia, at clinics for genitourinary medicine, family planning and termination of pregnancy in Edinburgh, were randomized to one of three partner interventions: patient referral, PTK (partners post urine for testing) or PDPT (1 g azithromycin for partners). Women submitted urine for chlamydia testing every 3 months. The primary outcome was re-infection assessed as time to first positive result by the Cox proportional hazard regression. The proportion of partners tested or treated with each intervention was determined. RESULTS: Out of 330 women, 215 (65%) were retested over 12 months. There were 32 of 215 women (15%) who retested positive (7, 15 and 10 women from the patient referral, PTK and PDPT groups, respectively). There was no significant difference in re-infection between PDPT versus patient referral (HR 1.32, 95% CI 0.50-3.56), PTK versus patient referral (HR 2.35, 95% CI 0.94-5.88) or PDPT versus PTK (HR 0.55, 95% CI 0.24-1.24). There was no significant difference in the proportion of partners confirmed tested/treated between the patient referral (34%) and PTK (41%, P = 0.32) or PDPT (42%, P = 0.28) groups. CONCLUSIONS: PTK and PDPT do not reduce re-infection rates in women with chlamydia compared with patient referral. However, PDPT may offer other advantages such as simplicity and cost compared with patient referral.