Comparison of Fecal Calprotectin and Myeloperoxidase in Predicting Outcomes in Inflammatory Bowel Disease

BACKGROUND

Biomarkers have been proposed as surrogate treatment targets for the management of inflammatory bowel disease (IBD); however, their relationship with IBD-related complications remains unclear. This study investigated the utility of neutrophil biomarkers fecal calprotectin (fCal) and fecal myeloperoxidase (fMPO) in predicting a complicated IBD course.

METHODS

Participants with IBD were followed for 24 months to assess for a complicated IBD course (incident corticosteroid use, medication escalation for clinical disease relapse, IBD-related hospitalizations/surgeries). Clinically active IBD was defined as Harvey-Bradshaw index >4 for Crohn's disease (CD) and simple clinical colitis activity index >5 for ulcerative colitis (UC). Area under the receiver-operating-characteristics curves (AUROC) and multivariable logistic regression assessed the performance of baseline symptom indices, fCal, and fMPO in predicting a complicated disease IBD course at 24 months.

RESULTS

One hundred and seventy-one participants were included (CD, n = 99; female, n = 90; median disease duration 13 years [interquartile range, 5-22]). Baseline fCal (250 μg/g; AUROC = 0.77; 95% confidence interval [CI], 0.69-0.84) and fMPO (12 μg/g; AUROC = 0.77; 95% CI, 0.70-0.84) predicted a complicated IBD course. Fecal calprotectin (adjusted OR = 7.85; 95% CI, 3.38-18.26) and fMPO (adjusted OR = 4.43; 95% CI, 2.03-9.64) were associated with this end point after adjustment for other baseline variables including clinical disease activity. C-reactive protein (CRP) was inferior to fecal biomarkers and clinical symptoms (pdifference < .05) at predicting a complicated IBD course. A combination of baseline CRP, fCal/fMPO, and clinical symptoms provided the greatest precision at identifying a complicated IBD course.

CONCLUSIONS

Fecal biomarkers are independent predictors of IBD-related outcomes and are useful adjuncts to routine clinical care.

Tōku Oranga: the subjective wellbeing and psychological functioning of postgraduate and medical students in Ōtautahi Christchurch

AIMS

Postgraduate and medical students are at risk of psychological distress and burnout, which can cause significant functional and occupational impairment. We aimed to report subjective wellbeing, psychological distress and burnout in postgraduate and medical students in Ōtautahi Christchurch, Aotearoa (New Zealand), and identify any associations between participant and course information and outcome measures including exposure to major earthquakes in 2010/2011 and the 2019 terrorist attack.

METHODS

A self-report online survey was completed by 140 students between November 2019 and March 2020. Life satisfaction, psychological distress and burnout were primary outcomes. Data were analysed using univariate and multivariable analysis.

RESULTS

High levels of psychological distress were present in both student groups. Burnout was reported by 78% of respondents. There were no significant associations found between exposure to the Christchurch earthquakes or terrorist attack with primary outcomes. Personality factors, resilience and perceived support and success were weakly associated with wellbeing, distress and burnout.

CONCLUSIONS

Postgraduates and medical students reported high levels of psychological distress and burnout. The earthquakes and terrorist attack do not appear to be associated with negative effects in these cohorts. Personality and resilience characteristics may assist in predicting students at risk of morbidity and evaluating potentially relevant interventions.

Adjuvant nodal field radiation in resected Stage III melanoma: A single-centre retrospective study in Christchurch, New Zealand

INTRODUCTION

Stage III melanoma is associated with poor outcomes. We studied the characteristics and outcomes of patients with resected Stage III melanoma before the routine use of adjuvant immunotherapy. Some of these patients received adjuvant nodal radiation with modern radiation techniques.

METHODS

We retrieved data of patients with resected Stage III melanoma treated in Christchurch over 10 years. Overall survival (OS), melanoma-specific survival (MSS), recurrence-free survival (RFS) and nodal recurrence-free rate (NRFR) were determined, and the association of these outcomes with tumour and treatment factors was investigated.

RESULTS

We identified 178 patients (110 male and 68 female), of whom 61 received adjuvant radiation. The median age was 66.6 years, and the median follow-up was 2.7 years. First recurrences occurred in 108 (61%) patients. There were 42 (24%) nodal field relapses and 103 (58%) distant relapses. One-half of nodal relapses in patients treated with adjuvant radiation were infield. The 5-year OS, RFS, MSS and NRFR were 46.4%, 26.8%, 53.7% and 69.6%, respectively. Adjuvant radiation was associated with improved RFS and no OS benefit. T4 disease and extranodal spread were associated with poorer OS, while extranodal spread and >3 involved nodes were associated with worse RFS.

CONCLUSION

Patients treated with adjuvant radiation remain at moderate risk of regional and high risk of distant relapse, despite the use of modern radiation techniques. Adjuvant radiation was associated with improved local control but infield recurrence rates remained a problem. The role of combined adjuvant radiation and immunotherapy in improving these outcomes requires further investigation.

Meta-analysis of the efficacy of taurolidine in reducing catheter-related bloodstream infections for patients receiving parenteral nutrition

BACKGROUND

Parenteral nutrition administered via central venous catheter is an established treatment option for people with intestinal failure. A serious complication of central venous catheters is the high risk of catheter-related blood stream infections (CRBSI). Catheter locking solutions are one strategy for CRBSI prevention, with the solution taurolidine showing beneficial effects. The aim of this meta-analysis was to identify and synthesize evidence to assess taurolidine efficacy against comparators for the prevention of CRBSI for people with intestinal failure on parenteral nutrition.

METHODS

Six health literature databases were searched for efficacy data of rate of CRBSI for taurolidine versus control among our study population, no study design limits were applied. Individual study data were presented for the number of CRBSI and catheter days, and rate ratio. Overall data were synthesized as a pooled risk ratio, with sub-group analysis by study design, control type, and taurolidine solution.

RESULTS

Thirty-four studies were included in the final analysis. At the individual level all studies showed superior efficacy of taurolidine versus control for prevention of CRBSI. When the data were synthesized, the pooled risk ratio was 0.49 (95% CI 0.46 to 0.53, p=<0.0001), indicating a 51% decreased risk of CRBSI through the use of taurolidine. Sub-group analysis showed no difference depending on study design (p=0.23), or control type (p=0.37), and a significant difference for taurolidine type (p=0.0005).

CONCLUSION

Taurolidine showed superior efficacy over controls regardless of study design or comparator group. The results show that taurolidine provides effective CRBSI reduction for people with intestinal failure on parenteral nutrition. This article is protected by copyright. All rights reserved.

Long-term efficacy of metacognitive therapy and cognitive behaviour therapy for depression

OBJECTIVE

To examine the two-year outcomes for depression, anxiety, cognitive and global social functioning after cognitive behavioural therapy (CBT) and metacognitive therapy (MCT) for depression.

METHOD

Participants were 31 adults with a diagnosis of major depressive disorder in a randomised pilot study comparing MCT and CBT. Therapy modality differences in change in depression and anxiety symptoms, dysfunctional attitudes, metacognitions, rumination, worry and global social functioning were examined at the two-year follow-up for those who completed therapy.

RESULTS

Significant improvements, with large effect sizes, were evident for all outcome variables. There were no significant differences in outcome between CBT and MCT. The greatest change over time occurred for depression and anxiety. Large changes were evident for metacognitions, rumination, dysfunctional attitudes, worry and global social functioning. Sixty-seven percent had not experienced a major depression and had been well during all of the past year, prior to the follow-up assessment.

CONCLUSION

The finding at end treatment, of no modality specific differences, was also evident at two-year follow-up. Although CBT and MCT targeted depression, improvements were much wider, and although CBT and MCT take different approaches, both therapies produced positive change over time across all cognitive variables. CBT and MCT provide treatment options, that not only improve the longer-term outcome of depression, but also result in improvements in anxiety, global social functioning and cognitive status.

Improvement in cognitive function in young people with bipolar disorder: Results from participants in an 18-month randomised controlled trial of adjunctive psychotherapy

OBJECTIVE

To examine the effects of 18 months of intensive stabilisation with medication management and Interpersonal and Social Rhythm Therapy or Non-specific Supportive Clinical Management on cognitive function in young people with bipolar disorder. Determinants of change in cognitive function over the 18 months of the trial were also examined.

METHOD

Patients aged 15-36 years with Bipolar I Disorder, Bipolar II Disorder and Bipolar Not Otherwise Specified were recruited. From a battery of cognitive tests, change scores for pre-defined domains of cognitive function were created based on performance at baseline and follow-up. Change was compared between the two therapy groups. Regression analysis was used to determine the impact of a range of clinical variables on change in cognitive performance between baseline and follow-up.

RESULTS

One hundred participants were randomised to Interpersonal and Social Rhythm Therapy (n = 49) or Non-specific Supportive Clinical Management (n = 51). Seventy-eight patients underwent cognitive testing at baseline and 18 months. Across both groups, there were significant improvements in a Global Cognitive Composite score, Executive Function and Psychomotor Speed domains from baseline to 18 months. Lower scores at baseline on all domains were associated with greater improvement over 18 months. Overall, there was no difference between therapies in change in cognitive function, either in a global composite score or change in domains.

CONCLUSION

While there was no difference between therapy groups, intensive stabilisation with psychological therapy was associated with improved cognitive function, particularly in those patients with poorer cognitive function at baseline. However, this was not compared with treatment as usual so cannot be attributed necessarily to the therapies.

150 ProBNP glycosylation of threonine 71 is increased with obesity in patients with heart failure

Funding Acknowledgements

The National Heart Foundation of New Zealand

Background

Heart failure (HF) is a leading cause of morbidity and mortality worldwide. Plasma levels of B-type natriuretic peptide (BNP) or its amino terminal congener (NT-proBNP) are used for HF diagnosis and risk stratification.  Circulating levels of both BNP and NT-proBNP are reduced by obesity and this phenomenon is one of the key weaknesses of the diagnostic performance of the natriuretic peptides in HF.  Formation of BNP from enzymatic cleavage of proBNP1-108 between residues 76 and 77 by corin and/or furin is influenced by the degree of proBNP glycosylation, therefore we investigated the relationship between proBNP glycosylation, plasma NT-proBNP and body mass index (BMI) in HF patients.

Methods

Three assays were developed to distinguish between total proBNP (glycosylated plus non-glycosylated proBNP), proBNP not glycosylated at threonine 71 (NG-T71) and proBNP not glycosylated in the central region (NG-C). Intra and inter-assay CVs were &lt;15%, limits of detection were &lt;2 pmol/L and samples diluted in parallel.

Results

Applying these assays and an NT-proBNP assay to plasma samples from 106 healthy volunteers and 238 patients with HF determined that concentrations (median(IQR)) of proBNP, NG-T71 and NT-proBNP were greater in HF patients compared to controls (24.9 (3.6-55), 9.4 (1.5-21) and 212 (104-409) pmol/L vs 3.0 (1.5-19), 3.0 (1.5-14.5) and 4.7 (2-8) pmol/L respectively, all p &lt; 0.012).  NG-C was undetectable in most samples. ProBNP levels in HF patients with BMI above and below 30 kg/m2 were not different (21.9 (2.6-70) pmol/L and 25.7 (3.9-53) pmol/L respectively, p = 0.85), whereas HF patients with BMI &gt; 30 had lower NT-proBNP and NG-T71 levels (121 (64-248) and 3 (1.5-16) pmol/L verse 271 (178-486) and 13.5 (1.5-24.2) pmol/L respectively, p &lt; 0.003) and higher proBNP:NT-proBNP and proBNP:NG-T71 ratios  (p = 0.001 and p = 0.02 respectively) than those with BMI &lt; 30.

Discussion and Conclusion

Using three new assays specific for different glycosylated forms of proBNP we have shown that the processing of proBNP is dysregulated in heart failure compared to controls due to increased glycosylation at threonine 71 of proBNP.  Obese patients with HF have even greater dysregulation, demonstrated by decreased concentrations of proBNP that is not glycosylated at T71 (NG-T71), and concomitant decreases in NT-proBNP.  Thus, we have shown for the first time that increased BMI is associated with increased proBNP glycosylation at T71 in patients with heart failure.  Glycosylation-induced impairment of proBNP processing explains, at least in part, the reduction in plasma concentrations of B-type cardiac natriuretic peptides observed in obesity. Using these assays to evaluate the proBNP profile of larger patient cohorts will further develop understanding of the relationships between BNP production, BMI and heart failure pathogenesis, which would be expected to lead to increased diagnostic performance.

P1756The protein APRIL predicts adverse outcomes in DAPT patients better than NT-proBNP and troponin

Aim

Dual antiplatelet therapy (DAPT) is a mainstay of post-ACS treatment. However, prediction of adverse events in these patients needs improving. We show here that the TNFα-related protein APRIL (which is produced in platelets and atherosclerotic plaque) is a superior predictor of MACE and new MI in DAPT recipients post-ACS.

Methods

We prospectively recruited 518 patients presenting with the primary complaint of acute chest pain to our hospital ED. Patients were adjudicated to have ACS by 2 independent cardiologists in accordance with ESC guidelines with hsTnI as biomarker. Plasma EDTA samples taken at presentation and 2 hours after were interrogated for APRIL measurements using a two site ELISA. Clinical data/variables, standard biochemistry analytes, hsTnT and NT-proBNP were also measured. Statistical assessments were made using SPSS v23 (IBM). Data for all biomarkers were treated as continuous variables and are presented as median (interquartile range, (IQR)). Statistical assessment of the comparative diagnostic abilities of APRIL, hsTnT, NT-proBNP and hsTnI were assessed using receiver operator curve (ROC) area under the curve (AUC) analysis. The comparative power of each biomarker (log values) to predict new MACE, MI, bleeding and mortality in 1) the whole group and in 2) DAPT recipients alone, within 2 yrs of index presentation was undertaken using a logistic regression base model (95% CI) that included all clinical variables and hsTnI and hsTnT, with APRIL and NT-proBNP each included in additional multivariate analyses.

Results

Of the 518 recruited patients (median age 63 (IQR: 54–73, 35% female), 152 were adjudicated to have ACS (29%, 115 MI, 37 UAP). Presentation APRIL levels were higher in those with a cardiac versus non-cardiac cause for presentation (3.0, (2.0–4.7) vs. 2.4, (1.6–3.8) ng/mL, P=0.001) and positively correlated with hsTnT and NT-proBNP (all P<0.001), but it did not add to the hsTnI (ROC = 0.96) or hsTnT (ROC =0.92) assisted diagnosis of ACS. In all 518 patients, in the multivariate regression model, APRIL was a significant independent predictor of mortality (n=54, P=0.032), new MI (n=43, P=0.006), new ADHF (n=24, P=0.016) and MACE (n=71, P=0.005) that was additive to NT-proBNP and troponin. In DAPT recipients alone (n=156), APRIL was the only biomarker to independently predict new MI (n=27, 95% CI: 1.125–3.982, P=0.020) and MACE (n=37, 95% CI: 1.058–3.389, P=0.031). None of the markers, only age, predicted bleeding episodes.

Conclusion

APRIL is an platelet/plaque derived marker that provides independent risk assessment in ACS patients. In DAPT recipients, the ability of APRIL to predict new MI and MACE is superior to that of cardiac troponins and NT-proBNP and could be used to identify high risk individuals.

Acknowledgement/Funding

Health Research Council of New Zealand; Heart Foundation of New Zealand

Prevalence of cognitive impairment in major depression and bipolar disorder

OBJECTIVES

The current study examines prevalence of cognitive impairment in four mood disorder samples, using four definitions of impairment. The impact of premorbid IQ on prevalence was examined, and the influence of treatment response.

METHODS

Samples were: (i) 58 inpatients in a current severe depressive episode (unipolar or bipolar), (ii) 69 unmedicated outpatients in a mild to moderate depressive episode (unipolar or bipolar), (iii) 56 outpatients with bipolar disorder, in a depressive episode, and (iv) 63 outpatients with bipolar disorder, currently euthymic. Cognitive assessment was conducted after treatment in Studies 1 (6 weeks of antidepressant treatment commenced on admission) and 2 (16-week course of cognitive behaviour therapy or schema therapy), allowing the impact of treatment response to be assessed. All mood disorder samples were compared with healthy control groups.

RESULTS

The prevalence of cognitive impairment was highest for the inpatient depression sample (Study 1), and lowest for the outpatient depression sample (Study 2). Substantial variability in rates was observed depending on the definition of impairment used. Correcting cognitive performance for premorbid IQ had a significant impact on the prevalence of cognitive impairment in the inpatient depression sample. There was minimal evidence that treatment response impacted on prevalence of cognitive impairment, except in the domain of psychomotor speed in inpatients.

CONCLUSIONS

As interventions aiming to improve cognitive outcomes in mood disorders receive increasing research focus, the issue of setting a cut-off level of cognitive impairment for screening purposes becomes a priority. This analysis demonstrates important differences in samples likely to be recruited depending on the definition of cognitive impairment and begins to examine the importance of premorbid IQ in determining who is impaired.

MR Imaging Characteristics Associate with Tumor-Associated Macrophages in Glioblastoma and Provide an Improved Signature for Survival Prognostication

BACKGROUND AND PURPOSE

In glioblastoma, tumor-associated macrophages have tumor-promoting properties. This study determined whether routine MR imaging features could predict molecular subtypes of glioblastoma that differ in the content of tumor-associated macrophages.

MATERIALS AND METHODS

Seven internally derived MR imaging features were assessed in 180 patients, and 25 features from the Visually AcceSAble Rembrandt Images feature set were assessed in 164 patients. Glioblastomas were divided into subtypes based on the telomere maintenance mechanism: alternative lengthening of telomeres positive (ALT+) and negative (ALT-) and the content of tumor-associated macrophages (with [M+] or without [M-] a high content of macrophages). The 3 most frequent subtypes (ALT+/M-, ALT-/M+, and ALT-/M-) were correlated with MR imaging features and clinical parameters. The fourth group (ALT+/M+) did not have enough cases for correlation with MR imaging features.

RESULTS

Tumors with a regular margin and those lacking a fungating margin, an expansive T1/FLAIR ratio, and reduced ependymal extension were more frequent in the subgroup of ALT+/M- (P < .05). Radiologic necrosis, lack of cystic component (by both criteria), and extensive peritumoral edema were more frequent in ALT-/M+ tumors (P < .05). Multivariate testing with a Cox regression analysis found the cystic imaging feature was additive to tumor subtype, and O6-methylguanine methyltransferase (MGMT) status to predict improved patient survival (P < .05).

CONCLUSIONS

Glioblastomas with tumor-associated macrophages are associated with routine MR imaging features consistent with these tumors being more aggressive. Inclusion of cystic change with molecular subtypes and MGMT status provided a better estimate of survival.

Five-year follow-up of a prospective randomised trial comparing ceramic-on-metal and metal-on-metal bearing surfaces in total hip arthroplasty

AIMS

The primary aim of this independent prospective randomised trial was to compare serum metal ion levels for ceramic-on-metal (CoM) and metal-on-metal (MoM) bearing surfaces in total hip arthroplasty (THA). Our one-year results demonstrated elevation in metal ion levels above baseline with no significant difference between the CoM and MoM groups. This paper reviews the five-year data.

PATIENTS AND METHODS

The implants used in each patient differed only in respect to the type of femoral head (ceramic or metal). At five-year follow-up of the 83 enrolled patients, data from 67 (36 CoM, 31 MoM) was available for comparison.

RESULTS

The mean serum cobalt (Co) and chromium (Cr) ion levels remained above baseline in both groups (CoM: Co 1.16 μg/l (0.41 to 14.67), Cr 1.05 μg/l (0.16 to 12.58); MoM: Co 2.93 μg/l (0.35 to 30.29), Cr 1.85 μg/l (0.36 to 17.00)) but the increase was significantly less in the CoM cohort (Co difference p = 0.001, Cr difference p = 0.002). These medium-term results, coupled with lower revision rates from national joint registries, suggest that the performance of CoM THA may be superior to that of MoM.

CONCLUSION

While both bearing combinations have since been withdrawn these results provide useful information for planning clinical surveillance of CoM THAs and warrants continued monitoring. Cite this article: Bone Joint J 2017;99-B:1298-1303.

Sexual minority youth and depressive symptoms or depressive disorder: A systematic review and meta-analysis of population-based studies

OBJECTIVE

Research has suggested that sexual minority young people are more likely to have depressive symptoms or depressive disorder, but to date most studies in the field have relied on convenience-based samples. This study overcomes this limitation by systematically reviewing the literature from population-based studies and conducting a meta-analysis to identify whether depressive disorder and depressive symptoms are elevated in sexual minority youth.

METHOD

A systematic review and meta-analysis were conducted and informed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement to determine if rates of depressive symptoms or depressive disorder differ for sexual minority youth, relative to heterosexual adolescents. MEDLINE, PsycINFO, EMBASE and ERIC databases were searched. Studies reporting depressive symptom data or the prevalence of depressive disorder in population-based samples of adolescents, which included sexual minority youth and heterosexual young people, were included in the review. A meta-analysis was conducted to examine differences between groups.

RESULTS

Twenty-three articles met the inclusion criteria. The proportion of sexual minority youth in the studies ranged from 2.3% to 12%. Sexual minority youth reported higher rates of depressive symptoms and depressive disorder (odds ratio = 2.94, p < 0.001 and standardized mean difference, d = 0.39, p < 0.001) in comparison to heterosexual young people. Female sexual minority youth were more likely to report depressive symptoms when compared to male sexual minority youth (standardized mean difference, d = 0.34, p < 0.001). Limitations included variations in how sexuality was operationalized and how depressive symptoms or depressive disorder was measured.

CONCLUSIONS

There is robust evidence that rates of depressive disorder and depressive symptoms are elevated in sexual minority youth in comparison to heterosexual young people. Despite the elevated risk of depressive symptoms or depressive disorder for sexual minority youth, the treatment for this group of young people has received little attention.

The scratch test for identifying the lower liver edge is at least as accurate as percussion and is significantly more effective for young trainees-a randomised comparative trial

BACKGROUND

Clinical examination of the liver requires experience to achieve accuracy. The scratch test is a simple technique to identify the lower liver edge and enhance liver palpation, and may be easier for trainees.

AIM

We aimed to evaluate the accuracy of the scratch test compared to percussion at different levels of medical training.

METHOD

Eight examiners, from trainee intern to consultant level, were randomised to scratch or percussion testing, followed by liver palpation, on 50 subjects. Later, each examiner performed the alternative test on each subject. Confidence with each test was rated 0-3 (unsuccessful-very confident). Ultrasound scan (US) was performed as a reference for liver location.

RESULTS

Ultrasound revealed 33/50 (66%) of livers extended below the right costal margin in the midclavicular line during quiet respiration (range 0.5-16cm). Of these, 33, 87% and 76% were identified within 2cm of the US location using scratch and percussion tests, respectively (p>0.05) for all examiners, but with significantly greater accuracy for the scratch test in young trainees (91% v 75%; p=0.016). Ability to palpate the liver was not different following either test. The training effect was assessed by comparing the accuracy results of the first 25 with the last 25 examined subjects, revealing a significant increase in accuracy with percussion from 71% to 85% (p=0.038) compared to no change with the scratch test (88% and 86%). Examiner confidence in the test result was significantly higher using the scratch test versus percussion, average confidence scores being 2.2 versus 1.8 (p<0.001), with a greater difference in the young trainee group at 2.4 versus 1.7 (p<0.001).

CONCLUSION

The scratch test was at least as accurate as percussion overall in identifying the lower liver edge and significantly more accurate for the young trainees. The scratch test requires less training and in addition, all examiners and especially the young trainees were significantly more confident in their findings using the scratch test.

The use of a lipped acetabular liner decreases the rate of revision for instability after total hip replacement: a study using data from the New Zealand Joint Registry

We compared the rate of revision for instability after total hip replacement (THR) when lipped and non-lipped acetabular liners were used. We hypothesised that the use of a lipped liner in a modular uncemented acetabular component reduces the risk of revision for instability after primary THR. Using data from the New Zealand Joint Registry, we found that the use of a lipped liner was associated with a significantly decreased rate of revision for instability and for all other indications. Adjusting for the size of the femoral head, the surgical approach and the age and gender of the patient, this difference remained strongly significant (p < 0.001). We conclude that evidence from the New Zealand registry suggests that the use of lipped liners with modular uncemented acetabular components is associated with a decreased rate of revision for instability after primary THR.

A prospective, randomised controlled trial comparing ceramic-on-metal and metal-on-metal bearing surfaces in total hip replacement

In a double-blinded randomised controlled trial, 83 patients with primary osteoarthritis of the hip received either a ceramic-on-metal (CoM) or metal-on-metal (MoM) total hip replacement (THR). The implants differed only in the bearing surfaces used. The serum levels of cobalt and chromium and functional outcome scores were compared pre-operatively and at six and 12 months post-operatively. Data were available for 41 CoM and 36 MoM THRs (four patients were lost to follow-up, two received incorrect implants). The baseline characteristics of both cohorts were similar. Femoral head size measured 36 mm in all but two patients who had 28 mm heads. The mean serum cobalt and chromium levels increased in both groups, with no difference noted between groups at six months (cobalt p = 0.67, chromium p = 0.87) and 12 months (cobalt p = 0.76, chromium p = 0.76) post-operatively. Similarly, the mean Oxford hip scores, Western Ontario and McMaster Universities Osteoarthritis index and University of California, Los Angeles activity scores showed comparable improvement at 12 months. Our findings indicate that CoM and MoM couplings are associated with an equivalent increase in serum cobalt and chromium levels, and comparable functional outcome scores at six and 12-months follow-up.

Polypharmacy--we make it worse! A cross-sectional study from an acute admissions unit

Although polypharmacy is a major problem in the elderly, very few data have been published from Australasia. We retrospectively audited 68% of elderly patients admitted acutely to our medical unit (n= 424, mean age 80.3 ± 8 years) during a 30-day period (September, 2008). We found that long-term medications increased during hospital stay from 6.6 ± 4 to 7.7 ± 4 (P < 0.001). Adverse drug reactions were responsible for 24 admissions (5.7%). Polypharmacy is made worse by acute admission to hospital.

An association between lifespan and variation in insulin-like growth factor I receptor in sheep

Longevity in livestock is a valuable trait. When productive animals live longer, fewer replacement animals need to be raised. However, selection for longevity is not commonly the focus of breeding programs as direct selection for long-lived breeding stock is virtually impossible until late in the reproductive life of the animal. Additionally the underlying genetic factors or genes associated with longevity are either not known, or not well understood. In humans, there is evidence that IGF 1 receptor (IGF1R) is involved in longevity. Polymorphism in the IGF1R gene has been associated with longevity in a number of species. Recently, 3 alleles of ovine IGF1R were identified, but no analysis of the effect of IGF1R variation on sheep longevity has been reported. In this study, associations between ovine IGF1R variation, longevity and fertility were investigated. Polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) was used to type IGF1R variation in 1,716 New Zealand sheep belonging to 6 breeds and 36 flocks. Ovine IGF1R C was associated with age when adjusting for flock (present 5.5 ± 0.2 yr, absent 5.0 ± 0.1 yr, P = 0.02). A general linear mixed effects model suggested an association (P = 0.06) between age and genotype, when correcting for flock. Pairwise comparison (least significant difference) of specific genotypes revealed the difference to be between AA (5.0 ± 0.1 yr) and AC (5.6 ± 0.2 yr, P = 0.02). A weak negative Pearson correlation between fertility and longevity traits was observed (r = -0.25, P < 0.01). The finding of an association between variation in IGF1R and lifespan in sheep may be useful in prolonging the lifespan of sheep.

Genetic variation in the renin-angiotensin-aldosterone system is associated with cardiovascular risk factors and early mortality in established coronary heart disease

This study examined renin-angiotensin-aldosterone (RAAS) system gene variants for associations with cardiovascular risk factors and outcomes in coronary heart disease. Coronary disease patients (n=1186) were genotyped for 21 single-nucleotide polymorphisms (SNPs) within angiotensinogen (AGT), angiotensin-converting enzyme (ACE), angiotensin-II type-1 receptor (AGTR1) and aldosterone synthase (CYP11B2). Associations with all-cause mortality and cardiovascular readmissions were assessed over a median of 3.0 years. The AGT M235T 'T' allele was associated with a younger age of clinical coronary disease onset (P=0.006), and the AGT rs2478545 minor allele was associated with lower circulating natriuretic peptides (P=0.0001-P=0.001) and E/E(1) (P=0.018). Minor alleles of AGT SNPs rs1926723 and rs11122576 were associated with more frequent history of renal disease (P0.04) and type-2 diabetes (P0.02), higher body mass index (P0.02) and greater mortality (P0.007). AGT rs11568054 minor allele carriers had more frequent history of renal disease (P=0.04) and higher plasma creatinine (P=0.033). AGT rs6687360 minor allele carriers exhibited worse survival (P=0.02). ACE rs4267385 was associated with older clinical coronary disease onset (P=0.008) and hypertension (P=0.013) onset, increased plasma creatinine (P=0.01), yet greater mortality (P=0.044). Less history of hypertension was observed with the AGTR1 rs12685977 minor allele (P=0.039). Genetic variation within the RAAS was associated with cardiovascular risk factors and accordingly poorer survival.

KCNE5 polymorphism rs697829 is associated with QT interval and survival in acute coronary syndromes patients

INTRODUCTION

The KCNE family is a group of small transmembrane channel proteins involved in potassium ion (K(+)) conductance. The X-linked KCNE5 gene encodes a regulator of the K(+) current mediated by the potassium channel KCNQ1. Polymorphisms in KCNE5 have been associated with altered cardiac electrophysiological properties in human studies. We investigated associations of the common rs697829 polymorphism from KCNE5 with baseline characteristics, baseline electrocardiographic (ECG) measurements, and patient survival in a cohort of post-acute coronary syndromes (ACS) patients (the Coronary Disease Cohort Study cohort).

METHODS AND RESULTS

DNA samples (n = 1,740) were genotyped for rs697829 using a TaqMan assay. Baseline ECG data revealed corrected QT (QTc) interval was associated with rs697829 in male, but not female, patients, being extended in the G genotype group (A 416 ± 1.71; G 431 ± 4.25 ms, P = 0.002). Covariate-adjusted survival was poorest in G genotype patients in Cox proportional hazard modeling of mortality data of males (P(overall) = 0.020). Male patients with G genotype had a hazard ratio of 1.44 (1.11-2.33) for death when compared to the A genotype male patients (P = 0.048) after adjustment for age, baseline log-transformed N-terminal pro-B-type natriuretic peptide (NTproBNP), β-blocker and insulin treatment, QTc interval, history of myocardial infarction, and physical activity score.

CONCLUSION

This study suggests an association between rs697829, a common single nucleotide polymorphism (SNP) from KCNE5, and ECG measurements and survival in postacute ACS patients. Prolonged subclinical QT interval may be a marker of adverse outcome in this group of patients. 

No evidence for a universal association between variation in faecal egg count for a mixed field-challenge of gastrointestinal parasites and the presence of the Ovar-DQA1 null haplotype in sheep

We tested the association of the Ovar-DQA1 null haplotype with faecal egg count (FEC) in 4676 male lambs sourced from 185 different sire-lines and four breeds. For each lamb a faecal sample was collected at weaning (approx. 4 months of age) and mid-autumn (approx. 9 months of age) and each was typed for the presence of Ovar-DQA1 null. General Linear Mixed Models (GLMMs) were used to analyse the relationship between FEC and Ovar-DQA1 null, both across and within breeds. Two models were used, the first testing the effect of the presence/absence of Ovar-DQA1 null and the second testing the effect of the number of copies of Ovar-DQA1 null present in an animal's genotype (i.e. dominant/recessive or additive effects). Across the breeds, no significant effect of the presence of Ovar-DQA1 null on FEC for Nematodirus sp., Strongyle genera, or total FEC was detected at either 4 or 9 months of age using either of the models. Within breeds, significant associations were detected at 4 months in South African Meat Merinos, with the presence of Ovar-DQA1 null in an animal's genotype being associated with a lower strongyle (absent: n=23, geometric mean=135epg; present: n=10, geometric mean=67epg; P=0.025) and total FEC (absent: n=23, geometric mean=220epg; present: n=10, geometric mean=121epg; P=0.017). These associations were not detected at 9 months of age.

Clinical assessment of a new anaesthetic drug administration system: a prospective, controlled, longitudinal incident monitoring study

A safety-orientated system of delivering parenteral anaesthetic drugs was assessed in a prospective incident monitoring study at two hospitals. Anaesthetists completed an incident form for every anaesthetic, indicating if an incident occurred. Case mix data were collected and the number of drug administrations made during procedures estimated. From February 1998 at Hospital A and from June 1999 at Hospital B, until November 2003, 74,478 anaesthetics were included, for which 59,273 incident forms were returned (a 79.6% response rate). Fewer parenteral drug errors occurred with the new system than with conventional methods (58 errors in an estimated 183,852 drug administrations (0.032%, 95% CI 0.024-0.041%) vs 268 in 550,105 (0.049%, 95% CI 0.043-0.055%) respectively, p = 0.002), a relative reduction of 35% (difference 0.017%, 95% CI 0.006-0.028%). No major adverse outcomes from these errors were reported with the new system while 11 (0.002%) were reported with conventional methods (p = 0.055). We conclude that targeted system re-design can reduce medical error.

Australasian Laparoscopic Colon Cancer Study shows that elderly patients may benefit from lower postoperative complication rates following laparoscopic versus open resection

BACKGROUND

A retrospective analysis of age-related postoperative morbidity in the Australia and New Zealand prospective randomized controlled trial comparing laparoscopic and open resection for right- and left-sided colonic cancer is presented.

METHODS

A total of 592 eligible patients were entered and studied from 1998 to 2005.

RESULTS

Data from 294 patients who underwent laparoscopic and 298 who had open colonic resection were analysed; 266 patients were aged less than 70 years and 326 were 70 years or older (mean(s.d.) 70.3(11.0) years). Forty-three laparoscopic operations (14.6 per cent) were converted to an open procedure. Fewer complications were reported for intention-to-treat laparoscopic resections compared with open procedures (P = 0.002), owing primarily to a lower rate in patients aged 70 years or more (P = 0.002). Fewer patients in the laparoscopic group experienced any complication (P = 0.035), especially patients aged 70 years or above (P = 0.019).

CONCLUSION

Treatment choices for colonic cancer depend principally upon disease-free survival; however, patients aged 70 years or over should have rigorous preoperative investigation to avoid conversion and should be considered for laparoscopic colonic resection.

REGISTRATION NUMBER

NCT00202111 (http://www.clinicaltrials.gov).

Polymorphisms in the ovine myostatin gene (MSTN) and their association with growth and carcass traits in New Zealand Romney sheep

Myostatin is a regulator of myogenesis and has been implicated in the regulation of adiposity and in controlling the structure and function of tendons. Polymerase Chain Reaction Single-Stranded Conformational Polymorphism (PCR-SSCP) analysis of intron-1 was used to identify five variants (designated A-E) of the myostatin gene (MSTN). The effect of this genetic variation on growth and carcass traits was investigated in 517 Romney male lambs from 17 sire-lines, born on a South Island New Zealand farm. General linear mixed effect models revealed that the presence of allele A in a lamb's genotype was associated with decreased leg, loin and total yield of lean meat, whereas the presence of allele B was associated with increased loin yield and proportion loin yield (loin yield divided by total yield expressed as percentage). The effect of the number of allele copies present was investigated, and it was found that the absence of A, or the presence of two copies of B, was associated with increased mean leg yield, loin yield and total yield. Two copies of B were also associated with a decrease in proportion of shoulder yield, whereas two copies of A were associated with a decrease in proportion of loin yield. Associations with allele C were not detected. No associations of MSTN variation with birth weight, weaning weight, pre-weaning growth rate, draft age and hot carcass weight (H-W) were detected. These results suggest that variation in ovine MSTN is associated with meat production, but not birth weight or growth rate in New Zealand Romney sheep.

Polymorphism of the ovine beta3-adrenergic receptor gene (ADRB3) and its association with wool mean staple strength and yield

We investigated the possibility that variation in ovine ADRB3 is associated with various wool traits, in particular mean staple strength (MSS). Polymerase chain reaction-single strand conformational polymorphism analysis of part of the ADRB3 intron was used to genotype 695 Merino lambs born on three farms in the South Island of New Zealand and which were shorn as 2-tooths. For each fleece, MSS, mean fibre diameter, mean staple length and yield were measured. The results from mixed-effects models and half-sib analyses suggest that ADRB3 alleles A and D have a negative impact on some wool traits, whereas ADRB3 alleles C and E appear to have a positive impact, with allele C potentially having a greater impact than allele E on MSS. This variation in the ADRB3 may assist in the genetic selection for increased MSS and yield in Merino sheep.

A copper(II)-selective chelator ameliorates left-ventricular hypertrophy in type 2 diabetic patients: a randomised placebo-controlled study

AIMS/HYPOTHESIS

Cu(II)-selective chelation with trientine ameliorates cardiovascular and renal disease in a model of diabetes in rats. Here, we tested the hypothesis that Cu(II)-selective chelation might improve left ventricular hypertrophy (LVH) in type 2 diabetic patients.

METHODS

We performed a 12 month randomised placebo-controlled study of the effects of treatment with the Cu(II)-selective chelator trientine (triethylenetetramine dihydrochloride, 600 mg given orally twice daily) on LVH in diabetic patients (n = 15/group at baseline) in an outpatient setting wherein participants, caregivers and those assessing outcomes were blinded to group assignment. Using MRI, we measured left ventricular variables at baseline, and at months 6 and 12. The change from baseline in left ventricular mass indexed to body surface area (LVM(bsa)) was the primary endpoint variable.

RESULTS

Diabetic patients had LVH with preserved ejection fraction at baseline. Trientine treatment decreased LVM(bsa) by 5.0 +/- 7.2 g/m(2) (mean +/- SD) at month 6 (when 14 trientine-treated and 14 placebo-treated participants were analysed; p = 0.0056 compared with placebo) and by 10.6 +/- 7.6 g/m(2) at month 12 (when nine trientine-treated and 13 placebo-treated participants were analysed; p = 0.0088), whereas LVM(bsa) was unchanged by placebo treatment. In a multiple-regression model that explained ~75% of variation (R (2) = 0.748, p = 0.001), cumulative urinary Cu excretion over 12 months was positively associated with trientine-evoked decreases in LVM(bsa).

CONCLUSIONS/INTERPRETATION

Cu(II)-selective chelation merits further exploration as a potential pharmacotherapy for diabetic heart disease.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN 12609000053224 FUNDING: The Endocore Research Trust; Lottery Health New Zealand; the Maurice and Phyllis Paykel Trust; the Foundation of Research, Science and Technology (New Zealand); the Health Research Council of New Zealand; the Ministry of Education (New Zealand) through the Maurice Wilkins Centre for Molecular Biodiscovery; and the Protemix Corporation.

Plasma levels of sex hormone-binding globulin, corticosteroid-binding globulin and cortisol in overweight subjects who develop impaired fasting glucose: a 3-year prospective study

Circulating sex hormone-binding globulin (SHBG), corticosteroid-binding globulin (CBG), and total and calculated free cortisol were measured in 206 overweight subjects to investigate whether or not they were markers of insulin resistance. Measurements were carried out on two occasions 36 months apart and subjects were grouped according to fasting plasma glucose. Fifty-one subjects, with a normal basal fasting glucose (<5.6 mmol/l) developed impaired fasting glucose 3 years later (> or = 5.6 mmol/l). Analysis either in toto or based on gender showed a highly significant increase in fasting insulin and insulin resistance, a modest increase in body mass index (BMI), but importantly no change in plasma SHBG, CBG, or cortisol concentrations. Subjects (n=101) with a normal fasting glucose both at baseline (<5.6 mmol/l) and at 36 months showed no significant change in fasting insulin, insulin resistance, SHBG, CBG, cortisol, or BMI. Cross-sectional analysis of the study population showed that plasma SHBG correlated negatively with insulin resistance both in men and women. Overall SHBG at baseline was not predictive of changes in fasting glucose. In females, plasma CBG correlated negatively with BMI. The major finding is that overweight subjects who developed impaired fasting glucose showed no significant change in plasma SHBG, CBG or cortisol, and therefore these indices are probably not early markers of insulin resistance in overweight subjects.

Harris-Galante II acetabular cup: a survival analysis

PURPOSE

To determine the survival rate of the Harris-Galante (HG) II cup and identify factors contributing to failure.

METHODS

271 primary total hip arthroplasties (THAs) performed between 1992 and 1999 in our hospitals using the HG II acetabular cup were retrospectively reviewed due to a high incidence of liner dissociation.

RESULTS

48 THAs were revised, 32 (67%) of which were due to liner dissociation. The Kaplan-Meier 10-year survival rate was 73%. Dislocation (p<0.001) and acetabular size (p=0.042) were independent predictors of acetabular component failure in the Cox's regression model.

CONCLUSION

The long-term outcome of the HG II cup is unsatisfactory. Although the HG II cup is no longer produced, numerous patients have this prosthesis in situ and should be reviewed regularly, as liner dissociation and retroacetabular osteolysis may occur.

Polymorphism at the ovine β3-adrenergic receptor locus (ADRB3) and its association with lamb mortality1

The beta3-adrenergic receptors (ADRB3) are guanine nucleotide-binding protein (G-protein)-coupled receptors predominantly found on the surface of adipocytes. They are major mediators of the lipolytic and thermogenic effects of high catecholamine concentrations, in particular norepinephrine. Recently, variation in the ovine beta3-adrenergic receptor gene (ADRB3) has been associated with lamb survival in Merino sheep. In this study, PCR-single strand conformational polymorphism analysis of part of the ADRB3 intron was used to genotype 13,420 lambs (Borderdale, n = 351; Corriedale, n = 4,260; Coopworth, n = 1,225; Dorset Down, n = 663; Dorset Down x Coopworth, n = 264; Hampshire, n = 230; Merino, n = 4,488; Merino x Coopworth, n = 329; Merino x Polwarth, n = 226; Polwarth, n = 928; Poll Dorset, n = 241; and Suffolk, n = 215) born on 22 farms throughout the South Island of New Zealand. Univariate and multivariate odds ratios calculated for each of the 8 alleles revealed weak to moderate associations of the A and E alleles with cold survival and alleles C and F with cold-related mortality, and a strong association of the D allele with cold-related mortality and total mortality. This variation at the ADRB3 locus can possibly be exploited as a gene marker to increase selection accuracy when breeding for more cold-tolerant lambs.

B-type natriuretic peptide infusions in acute myocardial infarction

BACKGROUND

Natriuretic peptides have actions likely to ameliorate cardiac dysfunction. B-type natriuretic peptide (BNP) is indicated as treatment for decompensated cardiac failure.

OBJECTIVE

To determine the utility of BNP in acute myocardial infarction (MI).

DESIGN

Double-blind randomised placebo-controlled trial.

SETTING

Tertiary hospital coronary care unit.

PATIENTS

28 patients with acute MI with delayed or failed reperfusion and moderate left ventricular dysfunction.

INTERVENTIONS

Infusion of BNP or placebo for 60 hours after MI.

MAIN OUTCOME MEASURES

Neurohormonal activation and renal function in response to BNP infusion, secondary end points of echocardiographic measures of left ventricular function and dimension.

RESULTS

BNP infusion resulted in a significant rise in BNP (276 pg/l vs 86 pg/l, p = 0.001). NT-proBNP levels were suppressed by BNP infusion (p = 0.002). Atrial natriuretic peptide (ANP) and NT-proANP levels fell with a significant difference in the pattern between BNP infusion and placebo during the first 5 days (p<0.005). C-type natriuretic peptide (CNP) and NT-proCNP levels rose during the infusion with higher levels than placebo at all measurements during the first 3 days (p<0.01). Cyclic guanosine monophosphate (cGMP) was raised during the infusion period showing a peak of 23 pmol/l on day 2 (placebo 8.9 pmol/l, p = 0.002), with a correlation between BNP and cGMP levels (p<0.001). Glomerular filtration rate (GFR) fell with BNP infusion but was not significantly lower than with placebo (71.0 (5.6) vs 75.8 (5.4) ml/min/1.73 m2, p = 0.62). Patients receiving nesiritide exhibited favourable trends in left ventricular remodelling.

CONCLUSIONS

Nesiritide, given soon after MI, induced increments in plasma cGMP and CNP and decrements in other endogenous cardiac peptides with a neutral effect on renal function and a trend towards favourable ventricular remodelling.

Cardiac sympathetic nerve activity and ventricular fibrillation during acute myocardial infarction in a conscious sheep model

The association between cardiac sympathetic nerve activity (CSNA) and ventricular fibrillation (VF) during acute myocardial infarction (MI) has not been assessed in conscious animal models. During the first 60 min post-MI, mean blood pressure (MBP), heart rate (HR), and CSNA were recorded continuously in 20 conscious sheep. Resistant sheep ( group A, n = 10) were compared with susceptible sheep ( group B, n = 10) who developed fatal VF ( n = 7) or sustained ventricular tachycardia (VT, n = 3). The mean time to VF/VT was 28.1 ± 3.3 min. In group B, MBP, HR, and CSNA were averaged at each consecutive minute from baseline at 14 min before the onset of VF/VT and compared with time-matched values in group A. When compared with those of group A, indexes of CSNA burst size increased before the onset of VF/VT: burst area/minute (F13,208 = 2.17, P = 0.01) and burst area/100 beats (F13,208 = 1.86, P = 0.04). By contrast, burst frequency indexes were not significantly different: burst frequency (F13,208 = 1.6, P = 0.09) and burst incidence (F13,208 = 1.48, P = 0.13). In group A, CSNA burst area/min and burst area/100 beats did not change across this time period (F13,117 = 0.97, P = 0.5, F13,117 = 0.96, P = 0.7) but increased with time in group B (F13,91 = 2.3, P = 0.01; and F13,91 = 2.25, P = 0.01). Between-group comparisons demonstrated no differences in time of onset of ventricular ectopic beats: 18.5 (range 12–24) in group A versus 15.0 min (range 7–22) in group B (Mann-Whitney U-test, P = 0.09). Pre-MI baroreflex slopes were similar: R-R slopes were 11.8 ± 2 and 15.6 ± 1.1 ms/mmHg ( t18 = −1.6, P = 0.14). CSNA slopes were −1.8 ± 0.3 and −2.3 ± 0.2%/mmHg ( t18 = −1.4, P = 0.2). An early increase in CSNA burst size indexes (before 60 min post-MI), mediated by an excitatory sympathetic reflex, is important in the genesis of VF/VT.

Alendronate prevents bone loss in patients with acute spinal cord injury: a randomized, double-blind, placebo-controlled study

CONTEXT

Patients who sustain an acute spinal cord injury (SCI) experience rapid dramatic reductions in bone mineral density (BMD), especially marked in sublesional areas and sometimes leading to hypercalcemia and hypercalciuria, as well as increased fracture risk.

OBJECTIVE

In this prospective, double-blind, randomized, placebo-controlled study, we evaluated the hypothesis that oral alendronate administration would preserve BMD when administered soon after acute SCI.

PATIENTS AND INTERVENTION

Thirty-one patients with acute SCI were randomly allocated to receive oral alendronate 70 mg/wk or placebo, within 10 d of acute SCI, for 12 months.

MAIN OUTCOME MEASUREMENTS

At entry and at 3, 6, 12, and 18 months, total body bone density, lumbar and hip BMD, ultrasound of the calcaneus, 24-h urinary calcium, and serum C-telopeptide (betaCTX) were measured.

RESULTS

At study entry, patients in the two groups were well matched for age, gender, severity of neurological deficit, BMD, urinary calcium, and betaCTX. BMD indices declined steadily in the placebo group, and this effect was attenuated significantly by alendronate. After 12 months, there was a 5.3% difference (P<0.001) in total body BMD and a 17.6% difference (P<0.001) in the total hip BMD between the two groups. Alendronate compared with placebo induced significant (P<0.001) reductions in urinary calcium excretion and serum betaCTX. No treatment-related side effects were noted.

CONCLUSIONS

We conclude that alendronate therapy, 70 mg/wk, initiated soon after acute SCI, prevents bone loss and is not associated with side effects.

The effect of streptozotocin-induced diabetes on the rat seminal vesicle: A possible pathophysiological basis for disorders of ejaculation

In the streptozotocin (STZ)-diabetic rat major increases in noradrenaline concentration and content of the seminal vesicles were evident as early as 7 weeks following induction of hyperglycemia and returned toward normal after 34 weeks of hyperglycemia. There were significant reductions in the concentration and content of dopamine at 19-42 weeks of diabetes, and small occasionally significant reductions in the content of serotonin and adrenaline, particularly around 19-26 weeks after STZ treatment. The uptake of tritiated noradrenaline in the diabetics was increased at 12 weeks compared to the controls, and decreased to control levels with increasing age. Release of tritiated noradrenline was increased in response to electrical field stimulation and high potassium solutions, and raising calcium concentration caused increased release at rest and during electrical stimulation. Immunohistochemical demonstration of tyrosine hydroxylase was increased during the period when the noradrenaline concentration and content were elevated. It is concluded that there are significant changes in the sympathetic innervation of the seminal vesicle during the course of STZ diabetes, and that alterations in the reuptake, release, and synthesis of the neurotransmitter noradrenaline may contribute to changes in the concentration of the amine in the tissue. It is possible that the changes observed are related to the remodeling and regrowth of sympathetic nerve endings damaged in the early stages of hyperglycemia. These changes may also contribute to disorders of ejaculation in diabetes.

Short-term statin treatment improves endothelial function and neurohormonal imbalance in normocholesterolaemic patients with non-ischaemic heart failure

OBJECTIVES

To investigate the effect of short-term statin treatment on impaired endothelium-dependent vasodilatation and haemodynamic abnormalities typically occurring in chronic heart failure (CHF).

METHODS

In a double-blind, crossover study endothelium-dependent vasodilatation was measured in conduit and resistance vessels of 23 patients with non-ischaemic CHF after 6 weeks of placebo and 40 mg atorvastatin. The haemodynamic impact was assessed by cardioendocrine hormones, echocardiography and clinical indicators of CHF.

RESULTS

Cholesterol concentrations were population average (low density lipoprotein 3.56 (SEM 0.16) mmol/l, triglycerides 1.70 (0.20) mmol/l and high density lipoprotein 1.17 (0.07) mmol/l). In resistance vessels, the area under the curve ratio during acetylcholine infusion increased from 9.2 (1.9) with placebo to 12.2 (2.1) with statin (p < 0.01). This improvement was reversed during co-infusion with the nitric oxide antagonist N(G)-monomethyl-L-arginine. In conduit arteries, flow-mediated dilatation increased from 5.64 (SEM 0.88)% with placebo to 6.83 (0.97)% with statin (p < 0.05). Endothelium-independent vasodilatation did not change (p = 0.68 for conduit and p = 0.45 for resistance vessels). Endothelin 1 and atrial natriuretic peptide (ANP) decreased from 1.57 (0.08) and 51.3 (1.0) with placebo to 1.42 (0.09) pg/ml (p < 0.05) and 42.1 (7.5) pmol/l (p < 0.05), respectively, with statin.

CONCLUSIONS

In patients with non-ischaemic CHF and population-average cholesterol concentrations, short-term statin treatment improves endothelial function in conduit and resistance vessels and lowers plasma endothelin 1 and ANP concentrations.

Plasma variation of corticosteroid-binding globulin and sex hormone-binding globulin

Sex hormone-binding globulin (SHBG) and corticosteroid-binding globulin (CBG) circulate in plasma and bind their cognate ligands with high affinity, offering a steroid delivery system to target tissues by a variety of mechanisms. Analysis of these steroid-binding proteins is gaining importance in the clinical setting, although more information is warranted on their diurnal and biological variation. This study shows that plasma SHBG (in normal subjects) exhibits little diurnal or biological variation over the 30 day period studied, in contrast to CBG, where plasma levels peak in the early afternoon. This leads to attenuation of the diurnal free cortisol level rhythm compared to total cortisol. We also show that plasma CBG is significantly lower in male subjects with the metabolic syndrome compared to age-matched lean counterparts, and may therefore act as a surrogate marker of insulin resistance. The consequence of lower levels of CBG in these obese male subjects is reflected by higher levels of circulating free cortisol, potentially offering a more favourable environment for adipogenesis.

Natriuretic peptide and adrenomedullin levels in chronic renal failure and effects of peritoneal dialysis

Plasma levels of B-type natriuretic peptide (BNP) and its N-terminal propeptide (NT-BNP) are elevated in renal impairment and provide a robust prognostic index. The effect of peritoneal dialysis on plasma NT-BNP, however, is unknown. Furthermore, no information exists regarding levels of the N-terminal propeptide for C-type natriuretic peptide (NT-CNP) in renal failure and the effects of peritoneal dialysis. Accordingly, we documented venous levels of these peptides, and adrenomedullin, across peritoneal dialysis. We measured venous BNP, NT-BNP, NT-CNP, adrenomedullin, blood urea nitrogen (BUN) and creatinine before, during and after completion of overnight peritoneal dialysis in 11 patients, and identical sampling was carried out in eight patients (controls) but between peritoneal dialysis treatments. Peptide levels were measured using well-validated, published methods. Baseline levels of NT-CNP (212, 150-303 pmol/l, median and 25th and 75th percentiles) were much higher than recorded previously in healthy volunteers or in heart failure, and correlated with plasma creatinine (rs=0.53, P<0.05). Peritoneal dialysis had no effect on plasma NT-CNP, nor on NT-BNP, BNP or adrenomedullin (all elevated above normal), whereas both BUN and creatinine levels, as expected, declined (P<0.001). We conclude that plasma levels of NT-CNP are grossly elevated in chronic renal failure and correlated with plasma creatinine, but are not altered by peritoneal dialysis. Likewise, BNP, NT-BNP and adrenomedullin are elevated but are not altered by peritoneal dialysis. This information is needed if levels of these hormones are to be used as prognostic indicators or as a guide to the management of patients with chronic renal failure.

Increased cardiac sympathetic nerve activity following acute myocardial infarction in a sheep model

The time course of cardiac sympathetic nerve activity (CSNA) following acute myocardial infarction (MI) is unknown. We therefore undertook serial direct recordings of CSNA, arterial blood pressure (MAP) and heart rate (HR) in 11 conscious sheep before and after MI, and compared them with 10 controls. Conscious CSNA recordings were taken daily from electrodes glued into the thoracic cardiac nerves. Infarction was induced under pethidine and diazepam analgesia by applying tension to a coronary suture. MI size was assessed by left ventricular planimetry (%) at postmortem, peak troponin T and brain natriuretic peptide levels (BNP). Baroreflex slopes were assessed daily using phenylephrine-nitroprusside ramps. The mean infarcted area was 14.4 +/- 2.9%, troponin T 1.88 +/- 0.39 microg l(-1) and BNP 8.4 +/- 1.3 pmol l(-1). There were no differences in haemodynamic parameters or CSNA between groups at baseline. MAP and HR remained constant following MI. CSNA burst frequency increased from baseline levels of 55.8 +/- 7.1 bursts min(-1) to levels of 77.5 +/- 8.7 bursts min(-1) at 2 h post-MI, and remained elevated for 2 days (P < 0.001). CSNA burst area also increased and was sustained for 7 days following MI (P= 0.016). Baroreflex slopes for pulse interval and CSNA did not change. CSNA increases within 1 h of the onset of MI and is sustained for at least 7 days. The duration of this response may be longer because the recording fields decrease with time. This result is consistent with a sustained cardiac excitatory sympathetic reflex.

The effect of Helicobacter pylori infection and dietary iron deficiency on host iron homeostasis: a study in mice

BACKGROUND

Helicobacter pylori, which requires iron to survive, may cause host iron deficiency by directly competing with the host for available iron or by impairing iron uptake as a consequence of atrophy-associated gastric hypochlorhydria. The aim of this study was to examine the effect of H. pylori infection and dietary iron deficiency on host iron homeostasis in a mouse model.

MATERIALS AND METHODS

H. pylori SS1-infected and uninfected C57BL/6 mice, fed either a normal diet or an iron-deficient diet, were assessed for iron status and infection-associated gastritis over a 30-week period.

RESULTS

After 10 weeks, serum ferritin values were higher in H. pylori-infected mice than in uninfected controls, irrespective of dietary iron intake (p = .04). The infection-related increase in body iron stores persisted in the iron-replete mice but diminished over time in mice with restricted dietary iron intake (p < .0001). At 30 weeks serum ferritin levels were lower in these animals (p = .063). No significant difference in bacterial numbers was detected at the 30-week time point (p > .05) and the histological changes observed were consistently associated with infection (p < .01) and not with the iron status of the mice (p = .771).

CONCLUSIONS

Infection with H. pylori did not cause iron deficiency in iron-replete mice. However, diminished iron stores in mice as a result of limited dietary iron intake were further lowered by concurrent infection, thus indicating that H. pylori competes successfully with the host for available iron.

Prospective audit of conversion from regular to lispro insulin during routine clinical care

BACKGROUND

Randomized controlled trials show that lispro insulin has the potential to improve glycaemic control. Observational, practice-based studies provide information that is complementary to that obtained from randomized controlled trials and results of both types of studies are of relevance when advising patients of likely outcomes during routine clinical care.

AIMS

This prospective audit aimed to determine whether conversion from regular (short-acting, soluble) preprandial insulin to lispro during routine clinical care improved glycated haemoglobin.

METHODS

Eligible patients were those using regular insulin before main meals and a basal neutral protamine Hagedorn (NPH) insulin. Study group patients were those who chose to convert to lispro insulin. Patients who elected not to change their regimen were used as a comparison group. Follow up was for a minimum of 1 year.

RESULTS

Glycated haemoglobin (HbA(1c)) and body mass index showed no change in either the study or comparison groups. Post-hoc analysis revealed that the patients most likely to improve their HbA(1c) on lispro were those with a higher baseline HbA(1c). Patients using lispro reported a decreased frequency of hypoglycaemia and improved convenience of use.

CONCLUSIONS

Administration of lispro insulin was perceived by patients as convenient to use and was also associated with less hypoglycaemia when compared with the use of regular insulin. There was, however, no improvement in HbA(1c). This finding may be informative when advising patients during routine clinical care of the likely metabolic outcome of changing their insulin regimen.

Effect of changes in body posture on vasoactive hormones in pre-eclamptic women

The aim of this study was to determine the normality or otherwise of neurohormone indices, particularly the sympathetic nervous system, in pre-eclamptic patients and document whether changes in body posture magnify any differences between pre-eclamptic and normal women. We studied 11 women with pre-eclampsia and compared them with 17 matched normotensive pregnant women and eight nonpregnant women. Measurements of arterial pressure, heart rate and neurohormones were carried out with subjects in the left lateral position, then supine, left lateral, with upright posture and finally with assumption of the left lateral position again. Main outcome measures were arterial pressure, heart rate and hormones (plasma norepinephrine, renin activity, natriuretic peptides and endothelin-1). We observed that plasma norepinephrine levels were higher in pre-eclamptic than normotensive pregnant women and this was most obvious in the upright position. Plasma renin activity was likewise higher in pre-eclamptic than normotensive pregnant women, again most obvious with upright posture. Plasma natriuretic peptides and endothelin-1 levels were similar in pre-eclamptics and normotensive pregnant women. These data strengthen the premise that pre-eclampsia is associated with sympathetic overactivity as reflected by plasma norepinephrine levels, most obviously observed in the upright position.

Decrease in cardiac output and muscle sympathetic activity during vasovagal syncope

The importance of cardiac output (CO) to blood pressure level during vasovagal syncope is unknown. We measured thermodilution CO, mean blood pressure (MBP), and leg muscle mean sympathetic nerve activity (MSNA) each minute during 60 degrees head-up tilt in 26 patients with recurrent syncope. Eight patients tolerated tilt (TT) for 45 min (mean age 60 +/- 5 yr) and 15 patients developed syncope during tilt (TS) (mean age 58 +/- 4 yr, mean tilt time 15.4 +/- 2 min). In TT patients, CO decreased during the first minute of tilt (from 3.2 +/- 0.2 to 2.5 +/- 0.3 l x min(-1) x m(-2), P = 0.001) and thereafter remained stable between 2.5 +/- 0.3 (P = 0.001) and 2.4 +/- 0.2 l x min(-1) x m(-2) (P = 0.004) at 5 and 45 min, respectively. In TS patients, CO decreased during the first minute (from 3.3 +/- 0.2 to 2.7 +/- 0.1 l x min(-1) x m(-2), P = 0.02) and was stable until 7 min before syncope, falling to 2.0 +/- 0.2 at syncope (P = 0.001). Regression slopes for CO versus time during tilt were -0.01 min(-1) in TT versus -0.1 l x min(-1) x m(-2) x min(-1) in TS (P = 0.001). However, MBP was more closely correlated to total peripheral resistance (R = 0.56, P = 0.001) and MSNA (R = 0.58, P = 0.001) than CO (R = 0.32, P = 0.001). In vasovagal reactions, a progressive decline in CO may contribute to hypotension some minutes before syncope occurs.

A fast method for monitoring foliage density in single lower-canopy trees

A subjective visual assessment of foliage density is the most widely used rapid method of determining forest health. For these assessments to be ecologically meaningful they must be reliable (have low inter- and intra-observer variability) and readily relate to a measure of physiological or physical stress. A simple rapid method for assessing percent foliage density in lower stature trees is described. This method has low inter-observer variability (standard deviation between observers=8.6%) and therefore, minimizes the risk of confounding the effects of different observers with genuine changes in density. The percentage changes in this measure of foliage density correlate well with percentage changes in biomass, allowing a ready interpretation of observed changes. The technique does not specifically identify the cause of the measured changes, however, with appropriate additional measures this problem may be overcome.

Standard setting in an objective structured clinical examination: use of global ratings of borderline performance to determine the passing score

BACKGROUND

Objective structured clinical examination (OSCE) standard-setting procedures are not well developed and are often time-consuming and complex. We report an evaluation of a simple 'contrasting groups' method, applied to an OSCE conducted simultaneously in three separate schools.

SUBJECTS

Medical students undertaking an end-of-fifth year multidisciplinary OSCE.

METHODS

Using structured marking sheets, pairs of examiners independently scored student performance at each OSCE station. Examiners also provided a global rating of overall performance. The actual scores of any borderline candidates at each station were averaged to provide a passing score for each station. The passing scores for all stations were combined to become the passing score for the whole exam. Validity was determined by making comparisons with performance on other fifth-year assessments. Reliability measures comprised interschool agreement, interexaminer agreement and interstation variability.

RESULTS

The approach was simple and had face validity. There was a stronger association between the performance of borderline candidates on the OSCE and their in-course assessments than with their performance on the written exam, giving a weak measure of construct validity in the absence of a better 'gold standard'. There was good agreement between examiners in identifying borderline candidates. There were significant differences between schools in the borderline score for some stations, which disappeared when more than three stations were aggregated.

CONCLUSION

This practical method provided a valid and reliable competence-based pass mark. Combining marks from all stations before determining the pass mark was more reliable than making decisions based on individual stations.

Differing thresholds for modulatory effects of adrenomedullin infusion on haemodynamic and hormone responses to angiotensin II and adrenocorticotrophic hormone in healthy volunteers

Experimental data indicate that adrenomedullin (AM) interacts at various levels with the renin-angiotensin-aldosterone system and the hypothalamic-pituitary-adrenal axis, but data from humans are scant. We examined the effects of intermediate-dose, short-term AM infusion on angiotensin II- and adrenocorticotrophic hormone (ACTH)-mediated hormone and haemodynamic responses in healthy subjects. Seven normal volunteers (age 18-25 years) completed a placebo-controlled crossover study. Each subject was studied on day 4 of two periods of a low-salt diet (40 mmol of sodium and 80 mmol of potassium daily), receiving incremental infusions of angiotensin II in the morning and ACTH in the afternoon of each study day, on a background infusion of AM (4 pmol.min(-1).kg(-1)) or vehicle (hemaccel). Achieved plasma AM levels (23+/-6 pmol/l) and peak angiotensin II levels (160 pmol/l) were similar on the two experimental days. While the pressor action of angiotensin II was attenuated by AM (P<0.01) and noradrenaline levels rose (P<0.05), the aldosterone response was unaltered. During ACTH infusion, AM increased heart rate (P<0.01), plasma adrenaline (P<0.01) and plasma noradrenaline (P<0.05), and augmented the cortisol response (P<0.01), but was without effect on aldosterone levels and blood pressure. We conclude that the threshold for the effects of AM on aldosterone secretion in humans is set higher than for other biological responses to this hormone, namely blood pressure, heart rate, sympathetic activity and cortisol secretion, under these experimental conditions.