147 ESTABLISHING A PERI-OPERATIVE MEDICAL SERVICE (POMS) FOR OLDER PEOPLE IN UROLOGY

Background

Older adults account for approximately 65% of patients undergoing urological procedures therefore as the population ages the demand is anticipated to rise. The benefits of Comprehensive Geriatric Assessment (CGA) have been proven in ortho-geriatrics and a number of surgical specialties but evidence in urology is lacking. The aim of this study was to assess the impact of a Peri-Operative Medical Service for older people (POMS) on patient outcomes in a urology inpatient population.

Methods

This was a single-centre retrospective study of patients ≥50 years with length of stay (LOS) >1 day admitted over two four month periods in 2018 (Pre-intervention) and 2019 (Intervention). Group differences in LOS and complications were examined using univariate regressions and then adjusted for sex, emergency admission, severity of procedure and Charlson Co-morbidity Index which also accounts for age. Secondary outcomes were to record undiagnosed medical conditions identified and the interventions made by the POMS.

Results

There were a total of 218 admissions from 211 patients with equal numbers of admissions in both the pre-intervention and intervention groups. No significant differences were detected for LOS (median 3 vs 4 days, p=0.11) or complications (32(29%) vs 40(37%), p=0.23) between pre-intervention and intervention groups. A new medical diagnosis was made in 13 (12%) of the pre-intervention v 43(39%) of the intervention group (p<0.001). The POMS recommended a change to management in 102 admissions (94%). The most common intervention was medication review: 64(59%) v 19(17%) (p<0.001).

Conclusion

The Peri-Operative Medical Service for older people can improve patient management by identifying and managing medical issues, complications and geriatric syndromes that may otherwise have been missed.

Cardiopulmonary Exercise Testing in Oesophagogastric Surgery: a Systematic Review

BACKGROUND

Cardiopulmonary exercise testing (CPX) can objectively measure fitness and oxygen uptake at anaerobic threshold. The relationship between fitness and postoperative outcomes after upper gastro-intestinal surgery is unclear. The aim of the present review is to assess the prognostic ability of CPX in predicting postoperative outcome associated with oesophagogastric surgery.

METHODS

Relevant studies were identified through a systematic search of EMBASE, Medline, CINAHL, Cochrane Library, and Web of Science to July 2019. The eligibility criteria for studies included prognostic studies of upper gastro-intestinal surgery among adult populations using a preoperative CPX and measurement of postoperative outcome (mortality or morbidity or length of stay). Risk of bias was assessed using the QUIPS Quality in Prognostic Studies validated tool.

RESULTS

Thirteen papers with a total of 1735 participants were included in data extraction. A total of 7 studies examined the association between CPX variables and postoperative mortality. Patients undergoing gastro-intestinal surgery with lower anaerobic threshold values were found to have an increased risk of postoperative mortality. Similarly, a lower rate of oxygen consumption was found to be associated with higher mortality. There was conflicting evidence regarding the association between CPX variables and postoperative morbidity. The evidence did not demonstrate any association between preoperative CPX variables and hospital length of stay.

CONCLUSION

Studies report an association between CPX variables and postoperative mortality; however, there is conflicting evidence regarding the association between CPX variables and postoperative morbidity.

Probing human sperm metabolism using 13C-magnetic resonance spectroscopy

STUDY QUESTION

Can 13C-Magnetic Resonance Spectroscopy (MRS) of selected metabolites provide useful information about human sperm metabolism and how glycolysis or oxidative phosphorylation are used by different sperm populations?

SUMMARY ANSWER

Sperm populations, prepared by density gradient centrifugation (DGC) and incubated with either 13Cu-glucose, 13Cu-fructose or 13C1-pyruvate, showed consistent evidence of metabolism generating principally lactate and more intermittently bicarbonate, and significantly more lactate was produced from 13Cu-glucose by vital or motile sperm recovered from the 40/80% interface compared to those from the pellet, which could not be accounted for by differences in the non-sperm cells present.

WHAT IS KNOWN ALREADY

Previous studies have focused on CO2 or other specific metabolite production by human sperm and there remains considerable debate about whether glycolysis and/or oxidative phosphorylation is the more important pathway for ATP production in sperm.

STUDY DESIGN, SIZE, DURATION

Sperm populations were prepared by DGC and subjected to 13C-MRS to answer the following questions. (i) Is it possible to detect human sperm metabolism of 13C substrates implicated in energy generation? (ii) What are the kinetics of such reactions? (iii) Do different sperm populations (e.g. '80%' pellet sperm and '40%' interface sperm) utilise substrates in the same way? Semen samples from 97 men were used in these experiments; 52 were used in parallel for aims (i) and (ii) and 45 were used for aim (iii).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Sperm populations were prepared from ejaculates of healthy men using a Percoll/Phosphate Buffered Saline (PBS) DGC and then incubated with a range of 13C-labelled substrates (13Cu-glucose, 13Cu-fructose, 13C1-pyruvate, 13C1-butyrate, 13C3-lactate, 13C2,4-D-3-hydroxybutyrate, 13C5-l-glutamate, 13C1,2-glycine or 13Cu-galactose) along with penicillin/streptomycin antibiotic at 37°C for 4 h, 24 h or over 48 h for an estimated rate constant. Sperm concentration, vitality and motility were measured and, for a subset of experiments, non-sperm cell concentration was determined. A 9.4 T magnetic resonance spectrometer was used to acquire 1D 13C, inverse gated 1H decoupled, MRS spectra. Spectrum processing was carried out using spectrometer software and Matlab scripts to determine peak integrals for each spectrum.

MAIN RESULTS AND THE ROLE OF CHANCE

13Cu-glucose, 13Cu-fructose and 13C1-pyruvate were consistently converted into lactate and, to a lesser extent, bicarbonate. There was a significant correlation between sperm concentration and lactate peak size for 13Cu-glucose and 13Cu-fructose, which was not observed for 13C1-pyruvate. The lactate peak did not correlate with the non-sperm cell concentration up to 6.9 × 106/ml. The concentration of 13Cu-glucose, 13Cu-fructose or 13C1-pyruvate (1.8, 3.6, 7.2 or 14.4 mM) had no influence on the size of the observed lactate peak over a 4 h incubation. The rate of conversion of 13C1-pyruvate to lactate was approximately three times faster than for 13Cu-glucose or 13Cu-fructose which were not significantly different from each other. After incubating for 4 h, the utilisation of 13Cu-glucose, 13Cu-fructose or 13C1-pyruvate by sperm from the '40%' interface of the DGC was no different from those from the pellet when normalised to total sperm concentration. However, after normalising by either the vital or motile sperm concentration, there was a significant increase in conversion of 13Cu-glucose to lactate by '40%' interface sperm compared to pellet sperm (Vital = 3.3 ± 0.30 × 106 vs 2.0 ± 0.21 × 106; P = 0.0049; Motile = 7.0 ± 0.75 × 106 vs 4.8 ± 0.13 × 106; P = 0.0032. Mann-Whitney test P < 0.0055 taken as statistically significant). No significant differences were observed for 13Cu-fructose or 13C1-pyruvate.

LARGE SCALE DATA

Not applicable.

LIMITATIONS, REASONS FOR CAUTION

Only 13C labelled metabolites that accumulate to a sufficiently high concentration can be observed by 13C MRS. For this reason, intermediary molecules in the metabolic chain are difficult to observe without trapping the molecule at a particular step using inhibitors. Non-sperm cell concentration was typical of the general population and no link was found between these cells and the magnitude of the 13C-lactate peak. However, it is possible that higher concentrations than the maximum observed (6.9 × 106/ml) may contribute to exogenous substrate metabolism in other experiments.

WIDER IMPLICATIONS OF THE FINDINGS

13C-MRS can provide information on the underlying metabolism of multiple pathways in live sperm. Dysfunction in sperm metabolism, as a result of either impaired enzymes of lack of metabolisable substrate, could be detected in sperm by a non-destructive assay, potentially offering new treatment options to improve overall sperm quality and outcomes for reproduction.

STUDY FUNDING AND COMPETING INTERESTS

This work was supported by the Medical Research Council Grant MR/M010473/1. The authors declare no conflicts of interest.

Convection Oven Determination of Loss of Mass on Drying of Quick Frozen French Fried Potatoes: Collaborative Study

A collaborative study was carried out on one of the methods submitted to the Joint Economic Commission for Europe (ECE)/Codex Alimentarius Commission Group of Experts on the Standardization of Quick Frozen Foods for the determination of moisture in quick frozen french (fried potatoes. The method was based on the determination of loss of mass of the sample on drying in a convection oven 16 h at 103±2°C. Two samples of uncooked quick frozen french fried potatoes and 2 samples of oven quick frozen french fried potatoes were analyzed by 14 and 13 laboratories, respectively. The method is simple and was found to be analytically satisfactory with repeatability and reproducibility values of 0.21 and 2.00 g/100 g french fried potatoes, and 0.29 and 3.00 g/100 g oven french fried potatoes, respectively. The method was adopted by the Group of Experts in preference to other proposed procedures for this determination. The method has been adopted official first action by AOAC.

Migrant status and identification as ultra-high risk for psychosis and transitioning to a psychotic disorder

BACKGROUND

Certain migrant groups are more likely to develop a psychotic disorder compared to the native-born populations, and a younger age at migration is associated with greater risk. However, it is not known at which stage migration has an effect on the development of psychotic disorders. We examined whether migrants were more likely to be identified as ultra-high risk for psychosis (UHR) compared to native-born young people and whether migrant status was associated with the risk of transition to a full-threshold psychotic disorder.

METHODS

The cohort included all young people aged 15-24 who were identified as UHR at a specialist clinic over a five-year period (2012-16). Australian census data were used to obtain the at-risk population. Poisson regression was used to calculate rate ratios and Cox regression analysis determined hazard ratios.

RESULTS

467 young people were identified as UHR, of which 13.5% (n = 63) were born overseas. First-generation migrants were 2.6-fold less likely to be identified as UHR compared to Australian-born young people (IRR = 0.39, 95% CI [0.30, 0.51], P < 0.001). There was no difference between migrant and native-born young people in their risk of transitioning to a psychotic disorder (HR = 0.90, 95% CI [0.39, 2.08], P = 0.81).

CONCLUSIONS

UHR first-generation migrants may be under-accessing mental health services.

1H Magnetic Resonance Spectroscopy of live human sperm

STUDY QUESTION

Can ¹H Magnetic Resonance Spectroscopy (MRS) be used to obtain information about the molecules and metabolites in live human spermatozoa?

SUMMARY ANSWER

Percoll-based density gradient centrifugation (DGC) followed by a further two washing steps, yielded enough sperm with minimal contamination (<0.01%) from seminal fluid to permit effective MRS which detected significant differences (P < 0.05) in the choline/glycerophosphocholine (GPC), lipid and lactate regions of the ¹H MRS spectrum between sperm in the pellet and those from the 40%/80% interface.

WHAT IS KNOWN ALREADY

Current methods to examine sperm are either limited in their value (e.g. semen analysis) or are destructive (e.g. immunohistochemistry, sperm DNA testing). A few studies have previously used MRS to examine sperm, but these have either looked at seminal plasma from men with different ejaculate qualities or at the molecules present in pooled samples of lyophilized sperm.

STUDY DESIGN, SAMPLES/MATERIALS, METHODS

Sperm suspended in phosphate buffered saline (PBS) at 37°C were examined by ¹H MRS scanning using a ¹H excitation-sculpting solvent suppression sequence after recovery from fresh ejaculates by one of three different methods: (i) simple centrifugation; (ii) DGC with one wash; or (iii) DGC with two washes. In the case of DGC, sperm were collected both from the pellet (‘80%’ sperm) and the 40/80 interface (‘40%’ sperm). Spectrum processing was carried out using custom Matlab scripts to determine; the degree of seminal plasma/Percoll contamination, the minimum sperm concentration for ¹H MRS detection and differences between the ¹H MRS spectra of ‘40%’ and ‘80%’ sperm.

MAIN RESULTS AND THE ROLE OF CHANCE

DGC with two washes minimized the ¹H MRS peak intensity for both seminal plasma and Percoll/PBS solution contamination while retaining sperm specific peaks. For the MRS scanner used in this study, the minimum sperm concentration required to produce a choline/GPC ¹H MRS peak greater than 3:1 signal to noise ratio (SNR) was estimated at ~3 × 10⁶/ml. The choline/GPC and lactate/lipid regions of the ¹H spectrum were significantly different by two-way ANOVA analysis (P < 0.0001; n = 20). ROC curve analysis of these region showed significant ability to distinguish between the two sperm populations: choline/GPC ROC AUC = 0.65–0.67, lactate/lipid ROC AUC = 0.86–0.87.

LIMITATIONS, REASONS FOR CAUTION

Only 3–4 semen samples were used to assess the efficacy of each sperm washing protocol that were examined. The estimated minimum sperm concentration required for MRS is specific to the hardware used in our study and may be different in other spectrometers. Spectrum binning is a low resolution analysis method that sums MRS peaks within a chemical shift range. This can obscure the identity of which metabolite(s) are responsible for differences between sperm populations. Further work is required to determine the relative contribution of somatic cells to the MRS spectrum from the ‘40%’ and ‘80%’ sperm.

WIDER IMPLICATIONS OF THE FINDINGS

¹H MRS can provide information about the molecules present in live human sperm and may therefore permit the study of the underlying functional biology or metabolomics of live sperm. Given the relatively low concentration of sperm required to obtain a suitable MRS signal (~3 × 10⁶/ml), this could be carried out on sperm from men with oligo-, astheno- or teratozoospermia. This may lead to the development of new diagnostic tests or ultimately novel treatments for male factor infertility.

STUDY FUNDING AND COMPETING INTEREST(S)

This work was supported by the Medical Research Council Grant MR/M010473/1. The authors declare no conflicts of interest.

An approach for the identification of exemplar sites for scaling up targeted field observations of benthic biogeochemistry in heterogeneous environments

Continental shelf sediments are globally important for biogeochemical activity. Quantification of shelf-scale stocks and fluxes of carbon and nutrients requires the extrapolation of observations made at limited points in space and time. The procedure for selecting exemplar sites to form the basis of this up-scaling is discussed in relation to a UK-funded research programme investigating biogeochemistry in shelf seas. A three-step selection process is proposed in which (1) a target area representative of UK shelf sediment heterogeneity is selected, (2) the target area is assessed for spatial heterogeneity in sediment and habitat type, bed and water column structure and hydrodynamic forcing, and (3) study sites are selected within this target area encompassing the range of spatial heterogeneity required to address key scientific questions regarding shelf scale biogeochemistry, and minimise confounding variables. This led to the selection of four sites within the Celtic Sea that are significantly different in terms of their sediment, bed structure, and macrofaunal, meiofaunal and microbial community structures and diversity, but have minimal variations in water depth, tidal and wave magnitudes and directions, temperature and salinity. They form the basis of a research cruise programme of observation, sampling and experimentation encompassing the spring bloom cycle. Typical variation in key biogeochemical, sediment, biological and hydrodynamic parameters over a pre to post bloom period are presented, with a discussion of anthropogenic influences in the region. This methodology ensures the best likelihood of site-specific work being useful for up-scaling activities, increasing our understanding of benthic biogeochemistry at the UK-shelf scale.

Effect of ageing on neurocognitive function by stage of HIV infection: evidence from the Multicenter AIDS Cohort Study

BACKGROUND

The demographics of the HIV epidemic in the USA have shifted towards older age. We aimed to establish the relationship between the processes of ageing and HIV infection in neurocognitive impairment.

METHODS

With longitudinal data from the Multicenter AIDS Cohort Study, a long-term prospective cohort study of the natural and treated history of HIV infection among men who have sex with men in the USA, we examined the effect of ageing, HIV infection (by disease stage), and their interaction on five neurocognitive domains: information processing speed, executive function, episodic memory, working memory, and motor function. We controlled for duration of serostatus in a subanalysis, as well as comorbidities and other factors that affect cognition. Analyses were by linear mixed models for longitudinal data.

FINDINGS

5086 participants (47 886 visits) were included in the analytic sample (2278 HIV-seropositive participants contributed 20 477 visits and 2808 HIV-seronegative control participants contributed 27 409 visits). In an a-priori multivariate analysis with control variables including comorbidities and time since seroconversion, significant, direct negative effects of ageing were noted on all neurocognitive domains (p<0·0001 for all). Similar effects were noted for late-stage HIV disease progression on information processing speed (p=0·002), executive function (p<0·0001), motor function (p<0·0001), and working memory (p=0·001). Deleterious interaction effects were also noted in the domains of episodic memory (p=0·03) and motor function (p=0·02).

INTERPRETATION

A greater than expected effect of ageing on episodic memory and motor function with advanced stages of HIV infection suggests that these two domains are most susceptible to the progression of neurocognitive impairment caused by ageing in individuals with HIV. This deficit pattern suggests differential damage to the hippocampus and basal ganglia (specifically nigrostriatal pathways). Older individuals with HIV infection should be targeted for regular screening for HIV-associate neurocognitive disorder, particularly with tests referable to the episodic memory and motor domains.

FUNDING

National Institute of Mental Health.

Mixed membership trajectory models of cognitive impairment in the multicenter AIDS cohort study

OBJECTIVE

The longitudinal trajectories that individuals may take from a state of normal cognition to HIV-associated dementia are unknown. We applied a novel statistical methodology to identify trajectories to cognitive impairment, and factors that affected the 'closeness' of an individual to one of the canonical trajectories.

DESIGN

The Multicenter AIDS Cohort Study (MACS) is a four-site longitudinal study of the natural and treated history of HIV disease among gay and bisexual men.

METHODS

Using data from 3892 men (both HIV-infected and HIV-uninfected) enrolled in the neuropsychology substudy of the MACS, a Mixed Membership Trajectory Model (MMTM) was applied to capture the pathways from normal cognitive function to mild impairment to severe impairment. MMTMs allow the data to identify canonical pathways and to model the effects of risk factors on an individual's 'closeness' to these trajectories.

RESULTS

First, we identified three distinct trajectories to cognitive impairment: 'normal aging' (low probability of mild impairment until age 60); 'premature aging' (mild impairment starting at age 45-50); and 'unhealthy' (mild impairment in 20s and 30s) profiles. Second, clinically defined AIDS, and not simply HIV disease, was associated with closeness to the premature aging trajectory, and, third, hepatitis-C infection, depression, race, recruitment cohort and confounding conditions all affected individual's closeness to these trajectories.

CONCLUSION

These results provide new insight into the natural history of cognitive dysfunction in HIV disease and provide evidence for a potential difference in the pathophysiology of the development of cognitive impairment based on trajectories to impairment.

Thiopurine withdrawal during sustained clinical remission in inflammatory bowel disease: relapse and recapture rates, with predictive factors in 237 patients

BACKGROUND

Thiopurines (azathioprine and mercaptopurine) remain integral to most medical strategies for maintaining remission in Crohn's disease (CD) and ulcerative colitis (UC). Indefinite use of these drugs is tempered by long-term risks. While clinical relapse is noted frequently following drug withdrawal, there are few published data on predictive factors.

AIM

To investigate the success of planned thiopurine withdrawal in patients in sustained clinical remission to identify rates and predictors of relapse.

METHODS

This was a multicentre retrospective cohort study from 11 centres across the UK. Patients included had a definitive diagnosis of IBD, continuous thiopurine use ≥3 years and withdrawal when in sustained clinical remission. All patients had a minimum of 12 months follow-up post drug withdrawal. Primary and secondary end points were relapse at 12 and 24 months respectively.

RESULTS

237 patients were included in the study (129 CD; 108 UC). Median duration of thiopurine use prior to withdrawal was 6.0 years (interquartile range 4.4-8.4). At follow-up, moderate/severe relapse was observed in 23% CD and 12% UC patients at 12 months, 39% CD and 26% UC at 24 months. Relapse rate at 12 months was significantly higher in CD than UC (P = 0.035). Elevated CRP at withdrawal was associated with higher relapse rates at 12 months for CD (P = 0.005), while an elevated white cell count was predictive at 12 months for UC (P = 0.007).

CONCLUSION

Thiopurine withdrawal in the context of sustained remission is associated with a 1-year moderate-to-severe relapse rate of 23% in Crohn's disease and 12% in ulcerative colitis.

No association between Apoε4 alleles, HIV infection, age, neuropsychological outcome, or death

The ε4 allele of the apolipoprotein E (ApoE) gene may have important interactions with physical health and cognitive function among individuals with HIV disease. The purpose of this study is to examine the relationships between ε4, HIV disease, age, neuropsychological impairment, and death in a large, well-characterized study sample. A total of 2846 men participating in the Multicenter AIDS Cohort Study had ApoE genotyping and neuropsychological test data available for analysis. We found a significant association between HIV infection and time to death (from any cause), as well as older age, race, and education. But, ApoE status was not significantly associated with time to death. Similarly, we found a significant association between HIV infection and time to incident cognitive impairment, as well as age, education, and HIV serostatus; Apoε4 status was not related to incident cognitive impairment. There were no significant interactions between ApoE, HIV infection, and age on cognitive impairment. These data replicate and strengthen prior findings of the lack of association between ApoE ε4 and cognitive outcomes in HIV disease. We conclude that within the specific constraints of an exclusively male study in which the majority of participants were less than 65 years of age (range 22-87 years), it appears reasonable to conclude that the ε4 allele is not significantly interacting with HIV serostatus.

Sleep disordered breathing, fatigue, and sleepiness in HIV-infected and -uninfected men

Study Objectives

We investigated the association of HIV infection and highly active antiretroviral therapy (HAART) with sleep disordered breathing (SDB), fatigue, and sleepiness.

Methods

HIV-uninfected men (HIV−; n = 60), HIV-infected men using HAART (HIV+/HAART+; n = 58), and HIV-infected men not using HAART (HIV+/HAART−; n = 41) recruited from two sites of the Multicenter AIDS cohort study (MACS) underwent a nocturnal sleep study, anthropometric assessment, and questionnaires for fatigue and the Epworth Sleepiness Scale. The prevalence of SDB in HIV- men was compared to that in men matched from the Sleep Heart Health Study (SHHS).

Results

The prevalence of SDB was unexpectedly high in all groups: 86.7% for HIV−, 70.7% for HIV+/HAART+, and 73.2% for HIV+/HAART−, despite lower body-mass indices (BMI) in HIV+ groups. The higher prevalence in the HIV− men was significant in univariate analyses but not after adjustment for BMI and other variables. SDB was significantly more common in HIV− men in this study than those in SHHS, and was common in participants with BMIs <25 kg/m². HIV+ men reported fatigue more frequently than HIV− men (25.5% vs. 6.7%; p = 0.003), but self-reported sleepiness did not differ among the three groups. Sleepiness, but not fatigue, was significantly associated with SDB.

Conclusions

SDB was highly prevalent in HIV− and HIV+ men, despite a normal or slightly elevated BMI. The high rate of SDB in men who have sex with men deserves further investigation. Sleepiness, but not fatigue, was related to the presence of SDB. Clinicians caring for HIV-infected patients should distinguish between fatigue and sleepiness when considering those at risk for SDB, especially in non-obese men.

Cohort Profile: Recruitment cohorts in the neuropsychological substudy of the Multicenter AIDS Cohort Study

The Multicenter AIDS Cohort Study (MACS) is one of the largest and longest running studies of the natural and treated history of HIV disease. The Neuropsychological (NP) substudy was begun in 1988 following reports of significant adverse neurological consequences of HIV disease, including dementia. The goal was to characterize the neuropsychological deficits among individuals with HIV disease, and track the natural history of the neurological complications over time. There were three distinct MACS recruitment stages that focused on different groups of HIV-infected men, or men at risk for infection. Initially, a subcohort was evaluated semi-annually with NP tests but, beginning in 2005, the entire group of MACS participants have had NP examinations biannually, unless closer follow-up was warranted. The participants complete a battery of NP tests, and are classified as either normal, mildly or severely impaired using the Antinori criteria for HIV-Associated Neurocognitive Disorder (HAND). Additional behavioural data, including mood state and psychoactive substance use, are recorded as part of the main MACS data collection. The MACS public data set (PDS) has been available since 1994 and includes baseline and 6-monthly follow-up data. Beginning in October 1995, the PDS has been released annually with new releases superseding previous versions.

Association between systemic inflammation and obstructive sleep apnea in men with or at risk for HIV infection

BACKGROUND

We sought to determine whether markers of systemic inflammation are associated with the presence of moderate/severe obstructive sleep apnea (OSA) and whether this association differs based on HIV and HIV treatment status.

METHODS

HIV-uninfected men (HIV-; n=60), HIV-infected men receiving HAART (HIV+/HAART; n=58) and HIV-infected men not receiving HAART (HIV+/no HAART; n=41) underwent polysomnograpy and measurement of plasma levels of tumour necrosis factor (TNF)-α, soluble TNF-α receptors I and II (sTNFRI and sTNFRII) and interleukin (IL)-6. The relationship between moderate/severe OSA (respiratory disturbance index ≥15 apnea/hypopnea events/h) and inflammatory markers was assessed with multivariable regression models.

RESULTS

Compared with the HIV- men, HIV+/HAART men and HIV+/no HAART men had higher levels of TNF-α, sTNFRI and sTNFRII, independent of age, race, smoking status, obstructive lung disease (OLD) and body mass index (BMI). Moderate/severe OSA was present in 48% of the sample (HIV- 57%; HIV+/HAART 41%; HIV+/no HAART 44%). Among the HIV+/no HAART men, but not in the other groups, TNF-α, sTNFRII and IL-6 levels were higher in those with moderate/severe OSA compared to men with no/mild OSA after adjustment for age, race, smoking status, OLD and BMI. Within this group, the association of high TNF-α concentrations with moderate/severe OSA was also independent of CD4(+) T-cell count and plasma HIV RNA concentration.

CONCLUSIONS

Compared with HIV+/HAART men and HIV- men, markers of systemic inflammation were higher in HIV+/no HAART men. In these men, TNF-α was significantly related to OSA, independent of HIV-related covariates.

Kinetic modeling of hyperpolarized (13)C pyruvate metabolism in tumors using a measured arterial input function

Mathematical models are required to estimate kinetic parameters of [1-(13)C] pyruvate-lactate interconversion from magnetic resonance spectroscopy data. One- or two-way exchange models utilizing a hypothetical approximation to the true arterial input function (AIF), (e.g. an ideal 'box-car' function) have been used previously. We present a method for direct measurement of the AIF in the rat. The hyperpolarized [1-(13)C] pyruvate signal was measured in arterial blood as it was continuously withdrawn through a small chamber. The measured signal was corrected for T1 relaxation of pyruvate, RF pulses and dispersion of blood in the chamber to allow for the estimation of the direct AIF. Using direct AIF, rather than the commonly used box-car AIF, provided realistic estimates of the rate constant of conversion of pyruvate to lactate, kpl, the rate constant of conversion of lactate to pyruvate klp, the clearance rate constant of pyruvate from blood to tissue, Kip, and the relaxation rate of lactate T1la. Since no lactate signal was present in blood, it was possible to use a simple precursor-product relationship, with the tumor tissue pyruvate time-course as the input for the lactate time-course. This provided a robust estimate of kpl, similar to that obtained using a directly measured AIF.

Addressing the well-being of Aboriginal children in out-of-home care: are we there yet?

AIM

Children in out-of-home care (OOHC) have well-documented health and developmental needs. In Australia, Aboriginal children have significantly worse health outcomes than non-Aboriginal children. We wanted to identify the health and well-being of Aboriginal children entering OOHC, placed with an Aboriginal organisation, who accessed a specialised multidisciplinary clinic in south-western Sydney. We wanted to identify children entering care who were doing well and who improved in care. We also wanted to identify enablers and barriers to care.

METHODS

We analysed records of the first 100 children attending the OOHC clinic in south-western Sydney. Measures included clinical outcomes and recommendations at first and subsequent visits. Descriptive statistics were calculated using SPSS 16.0 for Windows (SPSS Inc., Chicago, IL, USA). Key stakeholders from the relevant agencies were interviewed about enablers and barriers to care by independent evaluators.

RESULTS

A significant proportion of children had health needs identified including speech delay (54%), under-immunisation (50%), behaviour problems (45%), hearing problems (44%), visual problems (35%) and dental problems (36%). Sixteen per cent of the children were doing well at first visit; a third improved in care, and a third remained stable. Significant differences were identified in health and educational needs between the under-5 year olds and the 5-13 year olds. Key barriers identified were systemic issues and lack of resources for intervention.

CONCLUSIONS

Children attending this clinic had similar rates of problems identified as other studies. School-age children appear to have significant additional health needs. Targeted developmentally and culturally appropriate interventions need to be provided to address the identified barriers to care.

Predicting Outcome after Traumatic Brain Injury

The purpose of this review is to look at the most recent work carried out on predicting outcome after traumatic brain injury (TBI). TBI is a leading cause of death and disability but prediction of long-term outcome for individual patients is difficult. In particular, predicting outcome in the first few hours or days after injury is limited by the paucity of scoring systems or clinical models available. Many clinical variables have been studied to determine if they may play a role in outcome prediction, including age, admission Glasgow Coma Score and pupillary reactivity. Newer variables being studied include serum biomarkers, abnormalities seen on magnetic resonance imaging and data obtained from evoked potentials and electroencephalography studies. There are many factors that impact on outcome and a perfect model is yet to be developed. Models must take into account the economic status of the country in which the trauma occurs. It is important that less affluent nations are not left behind in the search for accurate prognostic modelling.

Performance of Luminex and MSD high-sensitivity multiplex cytokine assays across multiple lots and laboratories (65.6)

Circulating cytokine levels can provide valuable information about immune status, but often require high-sensitivity assays. Multiplex assays hold great promise, especially when limited sample volumes are available. Four high-sensitivity cytokine multiplex assays (BioRad, BioSource/Invitrogen, Linco/Millipore, Meso Scale Discovery [MSD]) were evaluated for ability to detect circulating levels of cytokines, and for lot and laboratory variability. Assays were performed in six different laboratories utilizing archived serum from HIV-uninfected and -infected subjects from the Multicenter AIDS Cohort Study (MACS) and the Women’s Interagency HIV Study (WIHS), and commercial plasma samples spanning initial HIV viremia. In a majority of serum samples IL6, IL8, IL10, and TNFα were detectable with at least three kits, while IL1β was clearly detected with only one kit. No single multiplex panel detected all cytokines, and there were highly significant differences (p&lt;0.001) between laboratories and/or lots with all kits. The kits generally detected similar cytokine patterns over the onset of HIV viremia. This multi-site comparison suggests that current multiplex assays vary in their ability to measure serum and/or plasma levels of cytokines, and may not be sufficiently reproducible for repeated determinations over a long-term study or in multiple laboratories, but may be useful for longitudinal studies in which relative, rather than absolute, changes in cytokines are important.

Setting up a store‐and‐forward telemedicine service for acute trauma in a hospital trust

Telemedicine is a valuable, but as yet underused, resource for the delivery of health-care to patients. This paper describes the development of a new store-and-forward telemedicine service at the Queen Victoria Hospital, which is a tertiary referral centre for plastic surgery in the United Kingdom. The practical requirements of such a system, and the technical and legal difficulties experienced during the initial stages, are also discussed.