The impact of social determinants on health outcomes in a region in the North of England: a structural equation modelling analysis

OBJECTIVES

The aim of this study was to identify the impact of social determinants of health on physical and mental health outcomes in a UK population.

STUDY DESIGN

Structural equation modelling was used to hypothesise a model of relationships between health determinants and outcomes within a region in the North of England using large-scale population survey data (6208 responses).

METHODS

We analysed responses from a population survey to assess the influence of a deprivation-based index at the environmental level, education and income on a behaviour index (smoking, alcohol consumption, physical activity, and dietary habits) and the influence of all these factors on self-reported physical health and the influence of the behaviour index and income on mental wellbeing.

RESULTS

The proposed model was well supported by the data. Goodness-of-fit statistics, most notably a low value of the root mean square error of approximation (RMSEA), supported the validity of the proposed relationships (RMSEA = 0.054). The model revealed all examined paths to be statistically significant. Income and education were influential in determining an individual's behaviour index score, which, with income was the most important predictor of both the correlated outcomes of physical health and mental wellbeing (P < 0.001 in all cases).

CONCLUSIONS

Findings challenge the traditional view of singular causal pathways, emphasising that interventions should consider the underlying influencing socio-economic conditions, which would influence behaviour and therefore physical and mental wellbeing. The extent to which the model is supported by the data, and the statistical significance of individual relationships accentuates the imperative for comprehensive public health strategies that integrate multiple socio-economic factors.

Outcomes following interval delayed first rib resection for acute axillosubclavian deep venous thrombosis

BACKGROUND

Current management of axillosubclavian deep venous thrombosis (DVT) often uses thrombolysis for the DVT, prompt first rib removal, and occasional venoplasty or stenting. Our institution has increasingly used anticoagulation alone followed by interval first rib resection. We sought to analyze the effectiveness of this simplified technique.

METHODS

Between September 2012 and April 2021, 27 patients were identified within the institution's electronic medical record as having undergone first rib resection for upper extremity DVT. Seven of these patients had undergone preoperative thrombolysis before referral and were excluded. Among the remaining 20 patients, preoperative clinic charts were evaluated for age, venous segment involvement, contralateral limb involvement, presence of documented hypercoagulable state, duration of preoperative and postoperative anticoagulation, and postoperative outcomes.

RESULTS

Of the 20 patients (mean age, 26.2 years; 13 males) presenting with acute axillosubclavian DVT, all patients had right (n = 8) or left (n = 12) arm swelling. Five patients had extremity pain and four had extremity discoloration. Ten had axillosubclavian vein involvement, 9 had subclavian vein involvement, and 1 had axillary vein involvement. Two patients were on oral contraceptives and no patients had any other diagnosed hypercoagulable conditions. The mean duration of preoperative and postoperative anticoagulation was 3.2 ± 2.6 months and 2.1 ± 2.1 months, respectively. Nineteen patients underwent supraclavicular first rib resection and 1 patient underwent transaxillary resection. Twelve patients (60%) demonstrated complete DVT resolution by venous duplex examination during the postoperative period and 8 patients (40%) demonstrated partial recanalization/chronic DVT. Complications included one hemothorax and one thoracic duct injury. All 20 patients remain asymptomatic without arm swelling, with a mean follow-up of 55.1 ± 34.7 months.

CONCLUSIONS

Among patients presenting with acute axillosubclavian DVT, anticoagulation alone followed by interval first rib resection proved to be successful in providing symptomatic relief in the short to medium term. By eliminating the need for preoperative thrombolysis and postoperative venograms, this potentially cost-saving algorithm simplifies our management for acute venous thoracic outlet syndrome while maintaining good clinical outcomes. Because this study only analyzed our management algorithm's effectiveness in the short to medium term, the long-term effectiveness of this treatment will need to be demonstrated.

Duplex Scans Performed Immediately Following Lower Extremity Angioplasty and Stenting are of Limited Utility

BACKGROUND

Together with clinical examination, surveillance duplex examination represents the Society of Vascular Surgery recommendations for follow-up after endovascular intervention on the superficial femoral artery (SFA) and popliteal arterial segments. Compliance with postprocedural follow-up remains challenging. To establish a postangioplasty physiologic baseline, our institution began obtaining immediate postprocedural surveillance studies following lower extremity arterial interventions. We reviewed the utility of immediate postprocedural surveillance to determine if these studies enhanced postoperative care.

METHODS

Serial patients undergoing SFA and popliteal angioplasty and stenting from January 2014 to December 2020 were identified from our prospectively maintained Vascular Surgery database. Patient demographic information, procedural details, and procedural outcomes were subsequently analyzed from the electronic medical record.

RESULTS

Two hundred and sixty-three patients underwent 385 SFA and/or popliteal angioplasty/stenting interventions. Mean patient age was 64.8 ± 10 years. Among these 385 procedures, 350 (90.9%) were followed by immediate (<4 hours) postprocedural lower extremity arterial duplex scans. These 350 procedures included percutaneous transluminal angioplasty and/or stenting of the SFA (n = 236), popliteal artery (n = 34), or both (n = 80). Of these studies, 25 results (7.1%) were abnormal. One asymptomatic patient was admitted to hospital for immediate thrombolysis; however, the remaining 24 patients were followed clinically with no immediate intervention required. Abnormal results included 13 abnormalities appreciated on the final angiogram with 9 patients with known occlusions or stenoses, and 4 patients with mild to moderate CFA stenosis. Abnormal findings not detected on the final angiogram included 7 patients with mild to moderate stenosis and 5 patients with short occlusions (1.4%). All 5 patients with short segmental occlusions not detected on final arteriogram had preprocedural anatomy classified as either TASC C (TransAtlantic Inter-Society Consensus: SFA occlusions > 15 cm in length, n = 1) or TASC D (SFA occlusions > 20 cm in lenth, n = 4).

CONCLUSIONS

Immediate postprocedural duplex scans demonstrate significant vessel stenosis or occlusion in approximately 7% of cases but most stenoses and occlusions were noted on final arteriography. Duplex detected short segmental occlusions not noted on final arteriography were rare (1.4%), and occurred among patients with TASC C or TASC D occlusive disease. These duplex detected abnormalities rarely changed the patient's immediate plan of care. The performance of these immediate postprocedural duplex scans demonstrated limited clinical utility.

Safety of Utilizing Ultrasound as the Sole Modality of Follow-Up after Endovascular Aneurysm Repair

BACKGROUND

Post endovascular aneurysm repair (EVAR), surveillance with computed tomography-aortography (CTA) remains the most common practice, per Society for Vascular Surgery (SVS) guidelines. Chronic exposure to both radiation and intravenous (IV) contrast has raised concerns about long-term CTA follow-up (FU). As we have selectively used ultrasound (US) as a sole modality for post-EVAR surveillance, we sought to review our outcomes in this subset of patients.

METHODS

Retrospective review of our institution's vascular database identified 213 EVAR patients from 2013 to 2021. Fenestrated-EVAR and snorkel reconstructions were excluded. Patient demographics/outcomes, abdominal aortic aneurysm (AAA) characteristics, and FU modalities and outcomes were analyzed. Unpaired Student's t-test, ANOVA, and chi-squared test were used to assess group differences.

RESULTS

Eighty-five of the 213 EVAR patients (39.9%) were lost to FU within 3 months. Among the 128 remaining patients, 91 underwent FU using initial US, while 37 patients underwent post-EVAR FU initially using CTA. There were no significant differences (P > 0.05) between patient age (75.5 ± 9.4 vs. 75.3 ± 8.5), body mass index (BMI) (27.7 ± 5.4 vs. 28.9 ± 7.4), or mean AAA size (5.6 ± 1.1 vs. 5.9 ± 1.2) in US-surveilled and computed tomography (CT)-surveilled groups, respectively. Of the 91 patients, initially surveilled with US, 15 patients demonstrated endoleak and/or AAA growth (>5 mm). The 15 patients with US-demonstrated endoleak and/or growth underwent confirmatory CTA, with 3 patients eventually requiring EVAR revision. Among 37 patients initially surveilled with CT, 10 demonstrated significant growth and 2 patients eventually required EVAR revision. There were no patients with AAA rupture during post-EVAR surveillance. FU data were analyzed among a select lower-risk group of patients (preoperative AAA diameter ≤5.5 cm, BMI ≤30, and no endoleak at completion of EVAR). Among this group, there were no surveilled patients who required EVAR reintervention, regardless of surveillance modality (US n = 32; CT n = 4). The average FU was 29.5 ± 26.4 months in the US group and 26.4 ± 22.3 months in the CT group (P > 0.05).

CONCLUSIONS

Although initial CT surveillance following EVAR remains ideal, in select lower-risk patients, US is a viable alternative even for the initial post-procedure study. Advantages include decreased radiation exposure and cost. Our data suggest that US is a safe sole modality for surveillance following EVAR in selective patients.

Construction and characterization of a genome-scale ordered mutant collection of Bacteroides thetaiotaomicron

BACKGROUND

Ordered transposon-insertion collections, in which specific transposon-insertion mutants are stored as monocultures in a genome-scale collection, represent a promising tool for genetic dissection of human gut microbiota members. However, publicly available collections are scarce and the construction methodology remains in early stages of development.

RESULTS

Here, we describe the assembly of a genome-scale ordered collection of transposon-insertion mutants in the model gut anaerobe Bacteroides thetaiotaomicron VPI-5482 that we created as a resource for the research community. We used flow cytometry to sort single cells from a pooled library, located mutants within this initial progenitor collection by applying a pooling strategy with barcode sequencing, and re-arrayed specific mutants to create a condensed collection with single-insertion strains covering >2500 genes. To demonstrate the potential of the condensed collection for phenotypic screening, we analyzed growth dynamics and cell morphology. We identified both growth defects and altered cell shape in mutants disrupting sphingolipid synthesis and thiamine scavenging. Finally, we analyzed the process of assembling the B. theta condensed collection to identify inefficiencies that limited coverage. We demonstrate as part of this analysis that the process of assembling an ordered collection can be accurately modeled using barcode sequencing data.

CONCLUSION

We expect that utilization of this ordered collection will accelerate research into B. theta physiology and that lessons learned while assembling the collection will inform future efforts to assemble ordered mutant collections for an increasing number of gut microbiota members.

Tocilizumab for treatment of SARS-CoV-2 infection at home: A case report

SARS-CoV-2 virtual wards have successfully developed to monitor and escalate patients to hospital throughout the pandemic. Here we describe the case of an 84 year old man who received his complete care for severe SARS-CoV-2 pneumonitis at home, including the administration of oxygen, dexamethasone and tocilizumab.

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm

We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly a_{μ}≡(g_{μ}-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ω_{a} between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω[over ˜]_{p}^{'} in a spherical water sample at 34.7 °C. The ratio ω_{a}/ω[over ˜]_{p}^{'}, together with known fundamental constants, determines a_{μ}(FNAL)=116 592 040(54)×10^{-11} (0.46 ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both μ^{+} and μ^{-}, the new experimental average of a_{μ}(Exp)=116 592 061(41)×10^{-11} (0.35 ppm) increases the tension between experiment and theory to 4.2 standard deviations.

Environmental Distractions during Unsupervised Remote Digital Cognitive Assessment

The current demand for cognitive assessment cannot be met with traditional in-person methods, warranting the need for remote unsupervised options. However, lack of visibility into testing conditions and effort levels limit the utility of existing remote options. This retrospective study analyzed the frequency of and factors associated with environmental distractions during a brief digital assessment taken at home by 1,442 adults aged 23–84. Automated scoring algorithms flagged low data capture. Frequency of environmental distractions were manually counted on a per-frame and per-trial basis. A total of 7.4% of test administrations included distractions. Distractions were more frequent in men (41:350) than women (65:1,092) and the average age of distracted participants (51.7) was lower than undistracted participants (57.8). These results underscore the challenges associated with unsupervised cognitive assessment. Data collection methods that enable review of testing conditions are needed to confirm quality, usability, and actionability.

SAT0361 HEALTHY HUMAN SPINAL PROCESSES PERI-ENTHESEAL T-CELLS EXHIBIT A TR1 RATHER THAN A FOXP3 REGULATORY PHENOTYPE

Background:

We have previously reported that the normal spinal enthesis has populations of conventional T-cells including CD4+ & CD8+ T-cells that could be induced to produce IL-17A and TNF following anti-CD3/CD28 stimulation. The biology of such cells in health including their normal function and antigen reactivity is completely unknown. The purpose of this work was to define the phenotype, functionality and TCR reactivity of such T-cells in health.

Objectives:

To investigate whether the T-cells at the normal enthesis were regulatory in nature and to determine the type of regulatory T-cell as Tr1 or FOXP3 regulatory T-cell and to determine T-cell reactivity.

Methods:

Healthy interspinous ligament and spinous process with matched peripheral blood were harvested from patients undergoing elective spinal surgery (n=20). Entheseal soft tissue (EST) & peri-entheseal bone (PEB) was enzymatically digested and then sorted. Tr1 and Treg phenotypes were investigated using flow cytometry. Analysis of cytokines, growth factors and chemokines was performed by qRT-PCR, ELISA and flow cytometry. TCR sequencing was performed and a search for putative T-cell reactivity was done using TCR3 database.

Results:

Pro-inflammatory cytokine transcripts including IL-17A, IL-17F, IL-22, IL-23 (p19) & TNF were very low or undetectable in the Enthesis T-cells (Fig 1). Flow cytometry confirmed entheseal T-cells had a Tr1 phenotype (CD4+ LAG3+ CD49b+). Intracellular flow cytometry showed enthesis T-cells had very low FOXP3 expression, when compared to their blood counterparts. Intracellular flow cytometry and gene expression showed high basal expression of growth factors and regulatory proteins such as IL-10 & TGFβ, when compared to blood T-cells. RNA-Seq data, showed 13 potential TCR clonal sequences the most common of which are predicted to be reactive viral infection was CMV present in 8 sequences and Influenza A virus present in 2 sequences.

Conclusion:

The healthy human enthesis has regulatory T-cells of a Tr1 phenotype rather than a FOXP3 Treg phenotype. Many clones have antigen specificity indicating reactivity to prior infection. These findings suggest that conventional entheseal T-cells have a role in enthesis immune homeostasis.

Disclosure of Interests:

Hannah Rowe Grant/research support from: Novartis UK Investigator Initiated non-clinical research funding support, Abdulla Watad: None declared, Tobias Russell Grant/research support from: Novartis UK Investigator Initiated non-clinical research funding support, Kassem Sharif: None declared, Darren Newton: None declared, Miriam Wittmann: None declared, Qiao Zhou Grant/research support from: Funded by the PARTNER fellowship program, Almas Khan: None declared, Peter Loughenbury: None declared, Robert Dunsmuir: None declared, Abhay S Rao: None declared, Peter Millner: None declared, Tony Kenna: None declared, Matthew Brown: None declared, Charlie Bridgewood: None declared, Dennis McGonagle Grant/research support from: Janssen Research & Development, LLC

Intended and unintended consequences of abortion law reform: perspectives of abortion experts in Victoria, Australia

INTRODUCTION

In Victoria, Australia, abortion was decriminalised in October 2008, bringing the law in line with clinical practice and community attitudes. We describe how experts in abortion service provision perceived the intent and subsequent impact of the 2008 Victorian abortion law reform.

METHODS

Experts in abortion provision in Victoria were recruited for a qualitative semi-structured interview about the 2008 law reform and its perceived impact, until saturation was reached. Nineteen experts from a range of health care settings and geographic locations were interviewed in 2014/2015. Thematic analysis was conducted to summarise participants' views.

RESULTS

Abortion law reform, while a positive event, was perceived to have changed little about the provision of abortion. The views of participants can be categorised into: (1) goals that law reform was intended to address and that have been achieved; (2) intent or hopes of law reform that have not been achieved; (3) unintended consequences; (4) coincidences; and (5) unfinished business. All agreed that law reform had repositioned abortion as a health rather than legal issue, had shifted the power in decision making from doctors to women, and had increased clarity and safety for doctors. However, all described outstanding concerns; limited public provision of surgical abortion; reduced access to abortion after 20 weeks; ongoing stigma; lack of a state-wide strategy for equitable abortion provision; and an unsustainable workforce.

CONCLUSION

Law reform, while positive, has failed to address a number of significant issues in abortion service provision, and may have even resulted in a 'lull' in action.

Elevation of Lead in Human Blood from its Controlled Ingestion in Beer

1 Nine volunteers ingested high levels of lead in beer over a 28-d period. The increase in blood lead varied by a factor of about two. There was a similar two-fold variability in the whole-body uptake (mean 14%) of a single oral dose of the short-lived tracer 203Pb.

2 The average elevations led to estimates of the potential increment from consumption of alcoholic beverages which accord broadly with epidemiological observation and which, if relevant to intakes of lead in table wine, raise the possibility of considerably elevated levels in the blood of avid consumers.

3 Rate constants inferred for removal of stable lead from blood were lower than reported following intake of the tracer, reflecting feedback of lead from other compartments.

In-vitro antitumor-activity of the plant ribosome-inactivating proteins map-30 and gap-31

MAP 30 and GAP 31 are plant proteins isolated from Momordica charantia and Gelonium multiflorum, respectively. They have recently been shown to inhibit HIV-1 infection and replication. These proteins also possess a novel DNA topoisomerase-poison-like activity as well as ribosome inactivation. They were submitted to the Anti-Cancer Drug Screening Program of the National Cancer Institute and found to have potent anti-tumor activity against certain human tumor cell lines. The most sensitive cell lines responded to MAP 30 and GAP 31 with GI(50) that ranged from 0.01 to 10 mu g/ml and were unrelated to tumor type. These included cell lines from renal, non-small cell lung, and breast cancer. Targeted immunofusions made with MAP 30 or GAP 31 may be most effective toward these types of tumors.

Long-term retention of injected aluminium-26

Data previously reported on the whole-body retention of aluminium-26 (26Al) in a male volunteer are extended to 8 years after intravenous administration as citrate, when only ~2% of the injected tracer remained. The extended data, combined with a report elsewhere of the late urinary and faecal excretion of 26Al by this subject, reinforce indications that transdermal losses contribute to the clearance of systemic aluminium and mitigate its long-term accumulation from chronic exposure.

The case for early treatment of dislocations of the cervical spine with cord involvement sustained playing rugby

The most common injury in rugby resulting in spinal cord injury (SCI) is cervical facet dislocation. We report on the outcome of a series of 57 patients with acute SCI and facet dislocation sustained when playing rugby and treated by reduction between 1988 and 2000 in Conradie Hospital, Cape Town. A total of 32 patients were completely paralysed at the time of reduction. Of these 32, eight were reduced within four hours of injury and five of them made a full recovery. Of the remaining 24 who were reduced after four hours of injury, none made a full recovery and only one made a partial recovery that was useful. Our results suggest that low-velocity trauma causing SCI, such as might occur in a rugby accident, presents an opportunity for secondary prevention of permanent SCI. In these cases the permanent damage appears to result from secondary injury, rather than primary mechanical spinal cord damage. In common with other central nervous system injuries where ischaemia determines the outcome, the time from injury to reduction, and hence reperfusion, is probably important.

In order to prevent permanent neurological damage after rugby injuries, cervical facet dislocations should probably be reduced within four hours of injury.

Vasoactive properties of calcitonin gene-related peptide in human skin

AIM

Calcitonin gene-related peptide (CGRP) is a potential mediator of neurogenic inflammation in eczema, psoriasis and rosacea, and also contributes to vasodilatation and oedema in complex regional pain disorder. We investigated the feasibility of administering CGRP and its antagonist CGRP8-37 by iontophoresis in human skin to characterise their vasoactive profiles.

METHODS

Two doses of each peptide were administered by iontophoresis (5 and 10 min duration at 0.1 mA) to the forearm skin of 6 healthy young men. Skin blood flow responses over 25 min were assessed using laser Doppler imaging.

RESULTS

Iontophoresis of CGRP caused a gradual change in blood flow, with no significant difference in response between each dose. The peak change in flow had a coefficient of variation of 21% to 36%, while the variability of the total cumulative response was much greater. Iontophoresis of CGRP8-37 for 5 min caused only a small, transient increase in skin blood flow, while 10 min iontophoresis resulted in a significant increase in blood flow.

CONCLUSION

CGRP and CGRP8-37 can be administered by iontophoresis to human skin. Further experiments are needed to determine the optimum duration of iontophoresis and period of measurement.

How men with non-chlamydial, non-gonococcal urethritis are managed in Australasia

Summary:

The aim of this study was to ascertain how sexual health physicians in Australia and New Zealand manage men with chlamydia-negative non-gonococcal urethritis (NGU), particularly in relation to the notification of their female sexual partners. In July 2006, a cross-section survey was sent out to all the members of the Australasian Chapter of Sexual Health Medicine. Seventy-three percent of sexual health physicians believed that female partners of men who present with chlamydia-negative NGU were at risk of adverse reproductive health outcomes. At least 62% usually initiated some form of partner notification of female partners of men with chlamydia-negative NGU. However, only 19% (21/111) of sexual health physicians routinely tested for, and only 65% sometimes tested for, pathogens other than Neisseria gonorrhoeae and Chlamydia trachomatis in men presenting with NGU. These included Mycoplasma genitalium, herpes simplex virus, ureaplasma species, Trichomonas vaginalis and adenoviruses.

Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV

The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.

Low-dose cidofovir treatment of BK virus-associated hemorrhagic cystitis in recipients of hematopoietic stem cell transplant

In recipients of hematopoietic stem cell transplants (HSCTs), BK virus (BKV) has been associated with late-onset hemorrhagic cystitis (HC). In our institution, HSCT recipients with BKV-associated HC are treated with 1 mg/kg of cidofovir weekly. We identified HSCT recipients with BKV-associated HC, treated with weekly cidofovir. Microbiological response was defined as at least a one log reduction in urinary BKV viral load; clinical response was defined as improvement in symptoms and stability or reduction in the grade of cystitis. Nineteen allogeneic HSCT patients received a mean of 4.5 weekly doses of cidofovir. HC occurred at a mean of 68.7 days after transplant. A clinical response was detected in 16/19 (84%) patients, and 9/19 (47%) had a measurable microbiological response (8/10 nonresponders had a BKV viral load above the upper limit of the assay before treatment). Fourteen out of nineteen (74%) patients had no significant increase in serum creatinine. Five patients with renal dysfunction resolved after completion of the therapy and removal of other nephrotoxic agents. We conclude that weekly low-dose cidofovir appears to be a safe treatment option for BKV-associated HC. Although the efficacy of low-dose cidofovir is not proven, a prospective trial is warranted.

50. THE MANAGEMENT OF MEN WITH ACUTE CHLAMYDIA-NEGATIVE NON-GONOCOCCAL URETHRITIS: A LACK OF CONSENSUS AMONG AUSTRALIAN SEXUAL HEALTH PHYSICIANS

Objective: In clinical practice, chlamydia-negative non-gonococcal urethritis (NGU) is a common but poorly understood condition. The purpose of this study was to determine how Australian sexual health physicians manage men with this condition. Methods: In July 2006, a survey was mailed to all members of the Australasian Chapter of Sexual Health Medicine. Results: Of 166 surveys mailed out, 111 (67%) were returned completed. The majority of sexual health physicians (73%, n�=�81) indicated that they believed that female partners of men with acute chlamydia-negative NGU were at risk of adverse reproductive health outcomes. However, only 19% (n�=�21) routinely tested men with acute NGU for pathogens other than Neisseria gonorrhoeae and Chlamydia trachomatis. Most commonly, this was for M. genitalium (n�=�16). While 68% of respondents believed that M. genitalium was a cause of acute NGU, only 27% had access to testing for this organism. Other pathogens that were sometimes tested for included herpes simplex virus, Trichomonas vaginalis and adenovirus. Over half of sexual health physicians indicated that they would usually initiate notification of female sexual partners of men presenting with acute NGU, even before confirmatory test results were available. Conclusion: There are substantial differences in how acute, chlamydia-negative NGU is managed by Australian sexual health physicians. In part, these may relate to differences in beliefs around which pathogens are responsible for this condition and the availability of testing for particular pathogens. Notification of female partners is commonplace, even though the underlying cause of urethritis in affected men appears to be poorly defined.

Leptin deficiency produces contrasting phenotypes in bones of the limb and spine

Leptin is a hormone secreted by adipocytes that can regulate bone mass through a central, neuroendocrine signaling pathway. We tested the hypothesis that the response of bone tissue to altered leptin signaling is not uniform throughout the skeleton, but may vary between different skeletal regions and between cortical and trabecular moieties. We investigated the effects of leptin deficiency on muscle mass and bone architecture in obese, leptin-deficient (ob/ob) mice, and in lean controls. Results indicate that the obese mice weigh approximately twice as much as the lean mice, but the quadriceps muscles of the ob/ob mice are 40% smaller than those of controls. Leptin-deficient mice have significantly shorter femora, lower femoral bone mineral content (BMC), bone mineral density (BMD), cortical thickness, and trabecular bone volume compared to lean mice. Marrow tissue from the femora of ob/ob mice also shows a marked increase in adipocyte number compared to that of normal mice. In contrast to the pattern observed in the femur, ob/ob mice have significantly increased vertebral length, lumbar BMC, lumbar BMD, and trabecular bone volume compared to lean controls. Few adipocytes are observed in bone marrow from lumbar vertebrae of ob/ob mice, despite being numerous in marrow of the femur. However, like the femur, significant cortical thinning is also observed in the spine. These results indicate that the effects of altered leptin signaling on bone differ significantly between axial and appendicular regions, and may be mediated in part by muscle mass. The muscle hypoplasia, increased marrow adipogenesis, and decreased bone mass observed in the hindlimbs of ob/ob mice are also observed with aging in humans, suggesting that the ob/ob mouse may be a new and useful animal model for studying the relationship between bone marrow adipogenesis and osteopenia.

Radionuclide biokinetics database (RBDATA-EULEP): an update

The main activity of the RBDATA-EULEP project is the development of an electronic database of information on the biokinetics of radionuclides after intake by inhalation, ingestion or injection. It consists of linked tables of publications and experiments, with details and comments on the materials, procedures and results. By March 2004 it contained information on more than 1600 experiments from 600 publications. It will be extended and Internet access will also be provided.

Human biokinetics of inhaled terbium oxide

Four healthy men inhaled a monodisperse aerosol of 160Tb-labelled terbium oxide particles. The behaviour of the tracer was studied through measurements of body radioactivity and of its urinary and faecal excretion. Estimated early faecal losses in the four subjects ranged from 3% to 31% of the initial respiratory-tract deposit; most of the residue had become systemic within a year, with the principal deposit apparently in bone. Interference from this systemic deposit prevented accurate determination of the long-term pulmonary clearance kinetics, but the pattern was broadly what would be expected for Type M materials in the ICRP's Human Respiratory Tract Model. Averaged trends in the whole-body residue after approximately 1 year suggest a clearance half-life of approximately to 5 y.

RBDATA-EULEP: providing information to improve internal dosimetry

The overall aim of the concerted action RBDATA-EULEP is to provide information to improve the assessments of intakes of radionuclides and of the resulting doses. This involves a review of the behaviour of radionuclides following intake, and the transfer of expertise on methodology by organising small training workshops. The main activity is the development of an electronic database, effectively an annotated bibliography, but the electronic format used facilitates extension, updating and information retrieval. It consists of linked tables of references and experiments, with details and comments on the materials, procedures and results. By June 2002 it contained information on 524 inhalation, 282 ingestion and 164 injection experiments from 391 references. It will be extended, and Internet access provided. Prospective users include groups developing standards for internal dosimetry, scientists conducting research on radionuclide biokinetics and health physicists assessing the consequences of accidental intakes.

Human biokinetics of injected bismuth-207

A healthy male volunteer received an intravenous injection of 207Bi as citrate. Levels of the tracer in blood and in excretion samples, and its retention and distribution within the body, were investigated by appropriate radioactivity measurements. Levels in blood fell very rapidly, with only 1% of the injection remaining at 7 h and only ca. 0.1% at 18 days. There was rapid initial excretion, with 55% lost during the first 47 h, principally in urine; however, longer-term losses were much slower and 0.6% remained in the body at 924 days, when the contemporary rate of loss implied a half-life of 1.9 years. Integration of the retention pattern suggested that steady exposure to bismuth compounds could lead ultimately to a body content of approximately 24 times the daily systemic uptake. The largest organ deposit was in the liver, which after 3 days contained ca. 60% of the contemporary whole body content, consistent with reports of hepatotoxicity. These findings differ markedly from the metabolic model for bismuth proposed by the International Commission on Radiological Protection, which envisages a terminal half-life in the body of only 5 days and kidney as the site of highest deposition.

Long-term retention of injected barium-133 in man

Data are presented on the whole-body retention of 133Ba (half-life 10.74 y), over periods of up to 13 y after injection into six healthy male volunteers aged 25-81, and on their levels of biochemical markers for bone turnover. The results are relevant to propositions underlying the ICRP's current (Publication 67) and former (Publication 20) models of alkaline earth metabolism. The tracer was predominantly skeletal within weeks of the injection, as predicted in the current model. The mean retention accorded satisfactorily throughout with predictions based on the current model, but this accord does not necessarily validate the model, for two reasons. First, parameter values attributed to barium were influenced by data emerging during the early years of this study. Second, bone resorption rates in these subjects, as indicated by urinary markers, appear insufficient to explain the long-term reductions in skeletal retention which, in the present model, arise exclusively through this mechanism.

Middle latency auditory evoked responses and electroencephalographic derived variables do not predict movement to noxious stimulation during 1 minimum alveolar anesthetic concentration isoflurane/nitrous oxide anesthesia

The electroencephalogram (EEG) and middle latency auditory evoked responses (MLAER) have been proposed for assessment of the depth of anesthesia. However, a reliable monitor of the adequacy of anesthesia has not yet been defined. In a multicenter study, we tested whether changes in the EEG and MLAER after a tetanic stimulus applied to the wrist could be used to predict subsequent movement in response to skin incision in patients anesthetized with 1 minimum alveolar anesthetic concentration (MAC) isoflurane in N2O. We also investigated whether the absolute values of any of these variables before skin incision was able to predict subsequent movement. After the induction of anesthesia with propofol and facilitation of tracheal intubation with succinylcholine, 82 patients received 1 MAC isoflurane (0.6%) in N2O 50% without an opioid or muscle relaxant. Spontaneous EEG and MLAER to auditory click-stimulation were recorded from a single frontoparietal electrode pair. MLAER were severely depressed at 1 MAC isoflurane. At least 20 min before skin incision, a 5-s tetanic stimulus was applied at the wrist, and the changes in EEG and MLAER were recorded. EEG and MLAER values were evaluated before and after skin incision for patients who did not move in response to tetanic stimulation. Twenty patients (24%) moved after tetanic stimulation. The changes in the EEG or MLAER variables were unable to predict which patients would move in response to skin incision. Preincision values were not different between patients who did and did not move in response to skin incision for any of the variables. MLAER amplitude increased after skin incision. We conclude that it is unlikely that linear EEG measures or MLAER variables can be of practical use in titrating isoflurane anesthesia to prevent movement in response to noxious stimulation.

IMPLICATIONS

Reliable estimation of anesthetic adequacy remains a challenge. Changes in spontaneous or auditory evoked brain activity after a brief electrical stimulus at the wrist could not be used to predict whether anesthetized patients would subsequently move at the time of surgical incision.