Influence of rivaroxaban compared to vitamin K antagonist treatment upon development of cardiovascular calcification in patients with atrial fibrillation and/or pulmonary embolism

BACKGROUND

Vitamin K antagonists (VKA) such as warfarin or phenprocoumon have been the mainstay of therapy for long-term oral anticoagulant therapy (OAT) in patients with atrial fibrillation or with pulmonary embolism. Due to interferences with matrix Gla-protein, an important vitamin K-dependent local calcification inhibitor in cardiovascular structures, VKA antagonists stimulate cardiovascular calcification (CVC). In contrast, rivaroxaban, a nonvitamin K-dependent oral anticoagulant (NOAC), should be neutral in terms of CVC. We seek to investigate these potential differences in CVC development between VKA versus NOACs in a randomized controlled trial (RCT).

METHODS

The influence of rivaroxaban compared to vitamin K antagonist treatment upon development of cardiovascular calcification in patients with atrial fibrillation and/or pulmonary embolism trial (NCT02066662) is a multicenter, prospective RCT with a two-arm, open-label study design. The primary endpoint is the progression of coronary and aortic valve calcification (quantified as calcification volume score) as assessed by cardiac computed tomography (CT) at 24 months in patients either treated by rivaroxaban or VKA. A total of 192 patients were randomized in a 1:1 fashion. The main inclusion criteria were the presence of atrial fibrillation and/or pulmonary embolism with the indication for OAT and pre-existent coronary calcification. The development of CVC will be assessed by follow-up CT at 12 and 24 months.

RESULTS

In total 192 patients (median age 70, 72% male) were enrolled over a period of 5 years and followed up for 2 years.

[Perceptions on the use of opioids in COVID-19 : A survey of members of the German Association for Palliative Medicine]

BACKGROUND

Opioids efficiently alleviate pain and dyspnea. However, guidelines on symptom management with opioids differ, which may lead to an uncertainty concerning opioid indication and ethical implication among medical staff, especially when caring for COVID-19 patients.

AIMS

We aimed to examine the perception of members of the German Association for Palliative Medicine (DGP) concerning the administration of morphine as the gold standard opioid (subsequently termed M/O) for symptom control within and outside of a palliative care (PC) setting, including care for COVID-19 patients.

METHODS

DGP members received an anonymized online questionnaire (Survey Monkey®) containing questions regarding their perception of symptom management with M/O in general and in particular concerning COVID-19 patients. Participants were asked to rate their perception within and outside of a PC setting.

RESULTS

Of the 6129 DGP members, N = 506 participated. DGP physicians and nurses perceived handling of M/O as "certain and confident" (98%) and "clearly regulated" within PC (95%) but rated it significantly lower for outside PC (48%/38%). When caring for COVID-19 patients, handling of M/O was even less often rated "certain and confident" (26%) or "clearly regulated" (23%) for outside PC. Dyspnea (99%/52%), relief from the dying process (62%/37%), restlessness (30%/15%) and fear or panic (27%/13%) were more frequently rated as general indications for morphine within versus outside PC. Most participants (89%) wished to involve palliative care consultation teams.

CONCLUSIONS

DGP members perceived substantial uncertainty in the handling of M/O for medical fields outside PC. Uniform interdisciplinary guidelines for symptom control, more education, and involvement of a PC consultation team should be increasingly considered in the future.

Performance of automated single-lead ECG atrial fibrillation screening is associated with patient characteristics

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): The investigators received and unrestricted research grant by Pfizer/BMS. Pfizer/BMS was not involved in the planning, conduction, analysis, or interpretation of the data.

Introduction

Screening for atrial fibrillation (AF) with a single-lead electrocardiogram device is on the rise. However, little is known about influence of automated AF screening performance related to patient characteristics.

Aim

We tested the accuracy of automated AF detection of a single-lead ECG device and identified factors associated with diagnostic performance.

Methods

In 6482 subjects of community-pharmacies a single-time point AF screening was performed. All ECGs were analyzed by blinded human overread and compared to the automated results in context of patient characteristics.

Results

Automated screening showed good prediction of AF with an area under the receiver operating curve of 0.89; sensitivity 80%; specificity 98%; positive predictive value 71%; negative predictive value 99%. Good ECG signal quality was highly associated with correct measurement, while low signal quality leads to incorrect measurements. In a multivariate model we determined factors associated with excellent signal quality and as counterexample incorrect automatic AF identification. The Odds’ ratio (OR) for excellent signal quality was strongly associated with female sex, lower age, lower height, and higher body weight index (table).

Conclusion

The performance of automated AF screening is influenced by sex, age, height and body mass index. Potential target population groups, with high AF prevalence, have a higher chance of incorrect automatic measurement. We recommend an expert over-read, at least for all AF positive ECG recordings. Table 1 Excellent signal quality Incorrect measurement Univariate analysis Multivariate analysis Univariate analysis Multivariate analysis Parameter OR 95% CI P OR 95% CI P OR 95% CI P OR 95% CI P Sex [Female] 2.33 1.97-2.75 <0.001 1.92 1.53-2.41 <0.001 0.64 0.49-0.84 0.001 0.57 0.43-0.76 <0.001 Age [years] 0.97 0.96-0.98 <0.001 0.97 0.96-0.98 <0.001 1.07 1.04-1.09 <0.001 1.06 1.04-1.09 <0.001 Height [cm] 0.96 0.95-0.97 <0.001 0.98 0.97-0.99 0.003 1.01 0.99-1.03 0.068 Weight [kg] 0.99 0.99-1.00 0.418 0.99 0.98-0.99 0.003 BMI [kg/cm2] 1.04 1.03-1.06 <0.001 1.04 1.03-1.06 <0.001 0.91 0.88-0.95 <0.001 0.91 0.87-0.94 <0.001 CHADSVASC 1 0.95-1.06 0.912 1.06 0.97-1.17 0.205 Heart failure 0.62 0.41-0.93 0.022 1.86 1.13-3.05 0.015 Hypertension 0.96 0.83-1.11 0.58 1.06 0.80-1.39 0.689 Diabetes mellitus 0.85 0.68-1.07 0.159 0.82 0.54-1.25 0.359 Stroke / TIA 0.82 0.66-1.01 0.066 1.19 0.83-1.69 0.341 Vascular disease 0.89 0.75-1.07 0.213 1.31 0.98-1.77 0.70 OR – odd’s ratio, CI – confidence interval

57Accuracy of automated atrial fibrillation detection of a single-lead electrocardiogram device in a pharmacy-based mass screening

Funding Acknowledgements

The investigators received an unrestricted research grant by Pfizer/BMS. Pfizer/BMS was not involved in the planning, conduct, analysis, or interpreta

Background

Recently, various devices specifically designed to automatically detect atrial fibrillation, became available. Utility of automated atrial fibrillation detection in mass-screening remains unclear, because accuracy and validation of automated AF detection were mostly tested retrospectively in preselected cohorts with high atrial fibrillation prevalence.

Purpose

The aim of this analysis was to determine the accuracy of automated atrial fibrillation detection by a single-lead hand-held ECG device in a prospective population-based screening approach with several thousand subjects.

Methods

For automated atrial fibrillation detection, we investigated the MyDiagnostick a 30 cm long hand-held ECG-stick. All customers aged 65 years or older in the pharmacies were eligible to participate. After informed consent was obtained,  a one-minute single-lead ECG was recorded by trained staff.

Five levels of human ECG expert validation were performed to determine heart rhythm. All recorded unfiltered ECGs (Figure 1) were analyzed at least by two independent, blinded investigators, in case of an automated AF detection by at least 3 independent, blinded investigators. In case of contradiction in the first three levels of heart rhythm assessment, ECGs were analyzed in level 4 by two independent cardiologists. In level 5 all single-lead ECGs were unblinded and any single-lead ECG with a contradiction between the human ECG expert results and the automated ECG-Stick result were analyzed by a rhythm consortium consisting of 3 cardiologists. Final results for heart rhythm and ECG quality were stipulated by a hierarchical approach, whereas results in higher levels of analysis vote down results in earlier levels of analysis in case of a contradiction.

Results

In total, 7209 single-lead ECGs were available for analysis. The mean age was 74 ± 6 years, 42% (N = 3049) of participants were male, mean CHA2DS2-VASc score was 3.3 ± 1.4. We identified 5.3% (N = 383) patients with atrial fibrillation identified by human investigators. The ECG-Stick diagnosed 79% (N = 304) of the atrial fibrillation patients correctly. In 21% (N = 79/383) the result was false-negative, and in 1% (N = 72/7209) false-positive. In another 1% (N = 81/7209) single-lead ECG recordings were uninterpretable by expert investigators, although the automated analysis provided a result (SR: 27, atrial fibrillation: 54).

Using final level results by expert ECG reading as reference, automated ECG-Stick analysis showed good prediction in receiver operating calculation of atrial fibrillation with an area under the curve of 0.89, sensitivity: 80%, specificity: 98%, and a good interclass correlation coefficient of 0.75, 95%CI (0.74; 0.76)).

Conclusions

The results encourage the implementation of single-lead ECG devices for automated atrial fibrillation screening. A rhythm diagnosis by single-lead ECG seems possible for recordings with excellent ECG signal quality.

Abstract Figure. Single-lead ECG example (5 of 60 sec)

Distinct pressure half-time values by transthoracic echocardiography for grading of paravalvular regurgitation after transcatheter aortic valve replacement

Postprocedural aortic regurgitation (AR) has negative impact on patient outcome after transcatheter aortic valve replacement (TAVR). Standard assessment of AR severity by echocardiography is hampered after TAVR. Measurement of pressure half-time (PHT) by echocardiography is not limited in these patients but it may be affected by concomitant left ventricular hypertrophy (LVH). This study sought to evaluate distinct cut-off values of PHT differentiating between patients without and with more than mild LVH for grading of AR after TAVR with cardiac magnetic resonance (CMR) as the reference method for comparison. 71 patients (age 81 ± 6 years) with severe aortic stenosis undergoing TAVR were included into the study. Transthoracic echocardiography (TTE) and CMR were performed after TAVR. Left ventricular mass index was calculated by TTE. PHT was measured by continuous-wave Doppler echocardiography of aortic regurgitation jet. In 18 patients (25%) PHT could not be obtained due to no or very faint Doppler signal. Aortic regurgitant volume and regurgitant fraction were calculated by CMR by flow analysis of the ascending aorta. In 14 of 53 patients (26%) AR after TAVR was moderate or severe as categorized by CMR analysis. More than mild LVH was present in 27 of 53 patients (51%). PHT correlated inversely less to regurgitant fraction by CMR analysis in patients with LVH (r = −0.293; p = 0.138) than in patients without LVH (r = −0.455; p = 0.020). In patients without relevant LVH accuracy of PHT to predict moderate or severe paravalvular regurgitation AUC was 0.813 using a cut-off value of 347 ms and AUC was 0.729 in patients with more than mild LVH using a cut-off value of 420 ms. Analysis of PHT by TTE with distinct cut-off values for patients without and with more than mild LVH allows detection of moderate or severe AR after TAVR as defined by CMR. In none of the patients in which PHT could not be measured AR was categorized as more than trace by CMR analysis.

Substance use in kidney transplant candidates and its impact on access to kidney transplantation

BACKGROUND

Due to the increasing public acceptance of substance use, it is important to understand the association between substance use and access to kidney transplant and its outcomes. Here, we assess the sociodemographic predictors of substance use and the association between substance use and KT access.

METHODS

Predictors of substance use were examined using a multivariable-adjusted multinomial logistic regression. The association between current substance use (tobacco and drug) and time from referral to listing or receipt of a KT was examined using Cox proportional hazards models.

RESULTS

Of 2346 patients, the prevalence of current substance use was 17%. Predictors of current tobacco use were younger age, male sex, Caucasian ethnicity, being unemployed, and unmarried. Predictors of current drug use were younger age, male sex, Caucasian ethnicity, a history of non-adherence, and a history of mental health disorder. Patients with tobacco use had a decreased likelihood of being cleared for KT (hazard ratio [HR]:0.83[0.70, 0.99]) and receiving a KT (HR:0.80 [0.66, 0.96]). No association was seen in this sample for patients with drug use (HR:0.88 [0.69, 1.11] for being cleared for KT and 0.88 [0.69, 1.14] for KT, respectively).

CONCLUSIONS

Tobacco use was associated with a decreased likelihood of access to KT whereas there was no statistically significant difference in access to KT between patients with or without drug use.

Socio-economic inequalities in occurrence and health care costs in rheumatic and musculoskeletal diseases: results from a Spanish population-based study including 1.9 million persons

OBJECTIVES

To explore and compare the impact of socio-economic deprivation on the occurrence of the major rheumatic and musculoskeletal diseases (RMDs) and health care costs.

METHODS

Data on diagnoses, socio-demographics and health care costs of the entire adult population of the Basque Country (Spain) was used. Area deprivation index included five categories (1 to 5 (most deprived)). Cost categories included primary and specialist care, emergency room, hospitalisations, and drug prescriptions. Twenty-nine RMDs were grouped into seven groups: Rheumatoid Arthritis, Spondyloarthritis, Crystal Arthropathies, Osteoarthritis, Soft Tissue Diseases, Connective Tissue Diseases, and Vasculitis. The relations between the deprivation and the occurrence of RMD and costs were explored in regression models adjusted for relevant confounders.

RESULTS

Data from 1,923,156 adults were analysed. Mean age was 49.9 (SD18.4) years, 49% were males. Soft tissue diseases were the most prevalent RMD (5.5%, n=105,656), followed by osteoarthritis (2.2%, n=41,924). Socio-economic deprivation was associated with higher likelihood to have any of the 29 RMDs. The strongest socio-economic gradient was seen for the soft tissue diseases (OR 1.82 [95%CI 1.78;1.85], most vs. least deprived), followed by osteoarthritis (OR 1.59 [1.54;1.64]). Deprivation was also associated with higher costs across the majority of the conditions however patterns were more blurred, and inverse relationship was observed for connective tissue diseases, gout, hip osteoarthritis and undifferentiated (poly)arthritis.

CONCLUSIONS

Socio-economic deprivation is associated with increased occurrence of all RMDs, and in most cases more deprived patients incur higher health care costs.

Closed Incision Negative Pressure Therapy Reduces Surgical Site Infections in Vascular Surgery: A Prospective Randomised Trial (AIMS Trial)

BACKGROUND

Surgical site infections (SSIs) of the groin remain a crucial problem in vascular surgery, prompting great interest in preventative techniques, such as closed incision negative pressure therapy (ciNPT). This prospective randomised study aimed to assess the potential benefits of ciNPT application after groin incisions for vascular surgery.

METHOD

The study included 204 patients who underwent vascular surgery for peripheral artery disease (PAD) at two sites between July 2015 and May 2017. These patients received post-operative treatment with ciNPT (intervention group) or standard wound dressings (control group). After exclusion, 188 patients were assessed for SSIs using the Szilagyi classification.

RESULTS

The mean patient age was 66.6 ± 9.4 years (range 43-85 years), and 70% were male (n = 132). Regarding PAD stage, 52% were stage IIB, 28% stage III, and 19% stage IV. Among the patients, 45% (n = 85) had had a previous groin incision. Bacterial swabs were performed in each case of suspected SSI (22.8% [43/188]), while 76.7% (33/188) were negative, there were 5% [5/98] positive swabs in the intervention group and 5.5% [5/90] in the control group). Antibiotics were given to 13.2% of the intervention group, and 31.1% of the control group (p = .004). The control group experienced more frequent SSIs (33.3%; 30/90) than the intervention group (13.2%; 13/98; p = .0015; absolute risk difference -20.1 per 100; 95% CI -31.9 to 8.2). This difference was based on an increased rate of Szilagyi I SSI in the control group (24.6% vs. 8.1%, p = .0012).

CONCLUSION

The results confirmed a reduced superficial SSI rate after vascular surgical groin incision using ciNPT compared with standard wound dressings.

Use of two-dimensional speckle tracking echocardiography to predict cardiac events: Comparison of patients with acute myocardial infarction and chronic coronary artery disease

BACKGROUND

Two-dimensional speckle strain (2D STE) echocardiography can aid in the prognosis of acute myocardial infarction (AMI) and chronic coronary artery disease (CAD).

HYPOTHESIS

Differences occur in the prediction of cardiac events using 2D STE in AMI vs CAD patients.

METHODS

In this prospective study, 94 patients with a first AMI and successful revascularization, and 137 patients with stable CAD after complete revascularization were included. In all patients, we performed echocardiography and myocardial deformation analysis for layer-specific global circumferential strain (GCS) and longitudinal strain. Receiver operating characteristic (ROC) curve analysis was used to predict the presence of a cardiac event using strain values and baseline characteristics in different regression models.

RESULTS

Patients were followed for 3.6 ± 0.8 years. Strain parameters in AMI and CAD patients were significantly different with respect to the occurrence of a cardiac event. Frequency of diabetes and hypertension was associated with the presence of a cardiac event in CAD patients. Furthermore, in CAD patients, ROC analysis demonstrated that the addition of endocardial GCS to baseline characteristics and ejection fraction to a regression model significantly improved the prediction of cardiac events (area under curve = 0.86, cutoff value: 20%, sensitivity: 79%, specificity: 84%). In contrast, the addition of strain parameters in AMI patients did not increase the prediction power for cardiac events.

CONCLUSIONS

Global strain parameters by 2D STE may be useful for the prediction of cardiac events in patients with CAD but add no supplemental information to baseline characteristic and ejection fraction in patients with AMI.

Four terpene synthases contribute to the generation of chemotypes in tea tree (Melaleuca alternifolia)

BACKGROUND

Terpene rich leaves are a characteristic of Myrtaceae. There is significant qualitative variation in the terpene profile of plants within a single species, which is observable as "chemotypes". Understanding the molecular basis of chemotypic variation will help explain how such variation is maintained in natural populations as well as allowing focussed breeding for those terpenes sought by industry. The leaves of the medicinal tea tree, Melaleuca alternifolia, are used to produce terpinen-4-ol rich tea tree oil, but there are six naturally occurring chemotypes; three cardinal chemotypes (dominated by terpinen-4-ol, terpinolene and 1,8-cineole, respectively) and three intermediates. It has been predicted that three distinct terpene synthases could be responsible for the maintenance of chemotypic variation in this species.

RESULTS

We isolated and characterised the most abundant terpene synthases (TPSs) from the three cardinal chemotypes of M. alternifolia. Functional characterisation of these enzymes shows that they produce the dominant compounds in the foliar terpene profile of all six chemotypes. Using RNA-Seq, we investigated the expression of these and 24 additional putative terpene synthases in young leaves of all six chemotypes of M. alternifolia.

CONCLUSIONS

Despite contributing to the variation patterns observed, variation in gene expression of the three TPS genes is not enough to explain all variation for the maintenance of chemotypes. Other candidate terpene synthases as well as other levels of regulation must also be involved. The results of this study provide novel insights into the complexity of terpene biosynthesis in natural populations of a non-model organism.

Patency rate and quality of life after ultrasound-accelerated catheter-directed thrombolysis for deep vein thrombosis

Purpose

Studies on ultrasound-accelerated, catheter-directed thrombolysis of acute deep vein thrombosis emphasize good patency rates and low complication rates. Therefore, we analyzed quality of life besides technical success and patency in our patients after ultrasound-accelerated, catheter-directed thrombolysis.

Methods

Between 2009 and 2014, 42 patients suffering from iliofemoral deep vein thrombosis received ultrasound-accelerated, catheter-directed thrombolysis. Follow-up included clinical exanimation and ultrasound. Thirty patients (36 interventions), mean age 41.3 years (range 19–71 years), 56.6% women (17/30), completed the surveys. Five different scores were used to assess the quality of life and symptoms of postthrombotic syndrome: SF36, Euro-QOL 5D, PDI, VEINES-QOL/Sym, and the Villalta score.

Results

Mean therapy duration of ultrasound-accelerated, catheter-directed thrombolysis was 76.4 h and therapeutic success could be reported in 80.5% (29/36). Successful ultrasound-accelerated, catheter-directed thrombolysis was followed by stent angioplasty in 58.3% (21/36) procedures. Overall complication rate was 19.44%, mainly formed by minor bleedings. Mean follow-up was 38.5 months. The primary patency rate was 63.8%, the assisted-primary and the secondary patency rate were 80.5%. We observed an improved quality of life in our patients’ cohort compared to patients suffering from postthrombotic syndrome.

Conclusion

Although ultrasound-accelerated, catheter-directed thrombolysis is feasible with good patency rates, further prospective randomized trials are necessary to evaluate the value of thrombus removal in iliofemoral deep vein thrombosis in comparison to conservative treatment.

Work outcome in persons with musculoskeletal diseases: comparison with other chronic diseases & the role of musculoskeletal diseases in multimorbidity

Background

Chronic diseases and multimorbidity are increasingly common among persons in working age. This study explores the impact of type, number and combinations of chronic diseases with focus on the role of MSKD on (1) adverse work status (i.e. work disability (WD), economic unemployment (UE) or receiving a living allowance (LA)) and on (2) the occurrence of sick leave.

Methods

Subjects participating in a Dutch household survey, who were ≤65 years and could have paid work, provided data on socio-demographics and nine physician diagnosed chronic diseases. To explore the independent association of each chronic disease, of multimorbidity and of MSKD in context of multimorbidity with 1) work status (employed, WD, LA, UE) and 2) sick leave (SL) in those employed, multinomial logistic regressions and logistic regressions were used, respectively.

Results

Among 5396 subjects, MSKD was the most common morbidity (17%), multimorbidity occurred in 755/5396 (14%), 436/755 (61%) of subjects with multimorbidity had an MSKD. For MSKD the odds of WD, LA and UE were 2.06 [95% CI 1.56;2.71], 2.15[1.18;3.91] and 1.35[0.94;1.96], respectively, compared to being employed and the odds of SL in MSKD were 2.29[1.92;2.73]. Mental diseases had a stronger impact on all these outcomes. The odds for adverse work outcomes increased strongly with an increasing number of diseases. When an MSKD was part of multimorbidity, an additional impact on the association with WD and SL was observed.

Conclusions

Multimorbidity has a stronger impact on all work outcomes compared to single chronic diseases. The presence of the MSKD in the context of multimorbidity amplifies the chance of WD or SL.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1365-4) contains supplementary material, which is available to authorized users.

Myocardial deformation by strain echocardiography identifies patients with acute coronary syndrome and non-diagnostic ECG presenting in a chest pain unit: a prospective study of diagnostic accuracy

OBJECTIVE

Clinical assessment often cannot risk stratify patients hospitalized with chest pain and non-diagnostic electrocardiography (ECG) or myocardial enzymes. An inappropriate admission of patients with non-cardiac chest pain is an enormous cost factor.

METHODS

2315 patients who presented in the chest pain unit (CPU) with symptoms suggestive of acute coronary syndrome (ACS) were screened. All patients with relevant changes in ECG or myocardial enzymes were excluded. 268 consecutive patients (mean 58 ± 7 years, 88 men) were prospectively included and underwent echocardiography for left ventricular ejection fraction (LVEF), wall motion score index (WMSI) and strain parameter and a coronary angiography (CA) within 2 ± 1 days after admission.

RESULTS

Anatomically obstructive coronary artery disease (CAD) (≥70 % diameter stenosis) was present in 110 patients (41 %). The incremental value of LVEF, WMSI, and strain parameters to relevant clinical variables was determined in nested Cox models. Baseline clinical data associated with relevant CAD were age [hazard ratio (HR) 1.31, p = 0.03], arterial hypertension (HR 1.39, p = 0.03) and diabetes (HR 1.46, p = 0.001). The addition of endocardial global circumferential strain (GCS) (HR 1.57, p < 0.001) caused the greatest increment in model power (χ (2) = 43.4, p < 0.001). Optimal cut-off value was calculated as -21.7 % for GCS (sensitivity 87 %, specificity 76 %) to differentiate between these patients.

CONCLUSIONS

In patients with suspected ACS but without ECG changes or myocardial enzyme abnormalities, myocardial deformation imaging can identify patients at risk. This approach may be applied to improve decision guidance at the CPU for fast discharge of patients with non-cardiac chest pain or prompt cardiological allocation of patients with CAD.

CLINICAL TRIAL REGISTRATION

NCT 02357641.

Intensive sampling identifies previously unknown chemotypes, population divergence and biosynthetic connections among terpenoids in Eucalyptus tricarpa

Australian members of the Myrtaceae produce large quantities of ecologically and economically important terpenes and display abundant diversity in both yield and composition of their oils. In a survey of the concentrations of leaf terpenes in Eucalyptus tricarpa (L.A.S. Johnson) L.A.S. Johnson & K.D. Hill, which were previously known from few samples, exceptional variability was found in composition. The aim was to characterize the patterns of variation and covariation among terpene components in this species and to use this information to enhance our understanding of their biosynthesis. There were marked discontinuities in the distributions of numerous compounds, including the overall proportions of mono- and sesquiterpenes, leading us to delineate three distinct chemotypes. Overall, positive covariation predominated, but negative covariation suggested competitive interactions involved in monoterpene synthesis. Two groups of covarying monoterpenes were found, each of which was positively correlated with a group of sesquiterpenes and negatively correlated with the alternate sesquiterpene group. These results imply substantial cross-talk between mono- and sesquiterpene biosynthesis pathways. However, only those compounds hypothesized to share final carbocation intermediates or post-processing steps were strongly positively correlated within chemotypes. This suggests that the broader patterns of covariation among groups of compounds may result from co-regulation of multiple biosynthetic genes, controlling the complex terpene profiles of the chemotypes of Eucalyptus.

Differences in gene expression within a striking phenotypic mosaic Eucalyptus tree that varies in susceptibility to herbivory

BACKGROUND

Long-lived trees can accumulate mutations throughout their lifetimes that may influence biotic and abiotic interactions. For example, some Eucalyptus trees display marked variation in herbivore defence within a single canopy. These "mosaic" trees support foliage with distinct chemotypes which are differentially favoured by insect and vertebrate herbivores, resulting in susceptible and resistant branches within a single canopy. These mosaic trees provide a unique opportunity to explore the biosynthesis and genetic regulation of chemical defences in the foliage. The biosynthesis of the principal defence compounds, terpenoid-dominated essential oils, is well understood. However, the regulation of the genes involved and thus the control of phenotypic variation within a single tree canopy remains a mystery.

RESULTS

We sequenced the transcriptomes of the leaves of the two different chemotypes of a chemically mosaic Eucalyptus melliodora tree using 454 pyrosequencing technology. We used gene set enrichment analysis to identify differentially expressed transcripts and found the proportion of differentially expressed genes in the resistant and susceptible foliage similar to the transcript difference between functionally distinct tissues of the same organism, for example roots and leaves. We also investigated sequence differences in the form of single nucleotide polymorphisms and found 10 nucleotides that were different between the two branches. These are likely true SNPs and several occur in regulatory genes.

CONCLUSION

We found three lines of evidence that suggest changes to a 'master switch' can result in large scale phenotypic changes: 1. We found differential expression of terpene biosynthetic genes between the two chemotypes that could contribute to chemical variation within this plant. 2. We identified many genes that are differentially expressed between the two chemotypes, including some unique genes in each branch. These genes are involved in a variety of processes within the plant and many could contribute to the regulation of secondary metabolism, thus contributing to the chemical variation. 3. We identified 10 SNPs, some of which occur in regulatory genes that could influence secondary metabolism and thus contribute to chemical variation. Whilst this research is inherently limited by sample size, the patterns we describe could be indicative of other plant genetic mosaics.

Associations between serum leptin level and bone turnover in kidney transplant recipients

BACKGROUND AND OBJECTIVES

Obesity is associated with increased parathyroid hormone (PTH) in the general population and in patients with chronic kidney disease (CKD). A direct effect of adipose tissue on bone turnover through leptin production has been suggested, but such an association has not been explored in kidney transplant recipients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study examined associations of serum leptin with PTH and with biomarkers of bone turnover (serum beta crosslaps [CTX, a marker of bone resorption] and osteocalcin [OC, a marker of bone formation]) in 978 kidney transplant recipients. Associations were examined in multivariable regression models. Path analyses were used to determine if the association of leptin with bone turnover is independent of PTH.

RESULTS

Higher leptin levels were associated with higher PTH and lower vitamin D levels, and adjustment for vitamin D attenuated the association between leptin and PTH. However, higher leptin was also significantly associated with lower levels of the bone turnover markers: 1 SD higher leptin was associated with 0.13 lower log-OC (-0.17, -0.08, P < 0.001) and 0.030 lower log-CTX (-0.045, -0.016, P < 0.001) after multivariable adjustments. Path analysis indicated that the association of leptin with PTH was mostly mediated through vitamin D, and that the association between leptin and bone turnover was independent of PTH and vitamin D.

CONCLUSIONS

Elevated leptin level is associated with lower bone turnover independent of its effects on serum PTH in kidney transplant recipients.

The molecular basis of host plant selection in Melaleuca quinquenervia by a successful biological control agent

Melaleuca quinquenervia (Cav) S.T. Blake (broadleaf paperbark) is an Australian tree that has become a serious weed in many places around the world. Two insects Oxyops vitiosa (the melaleuca weevil), and Boreioglycaspis melaleucae (the melaleuca psyllid), which were introduced to Florida as part of a biological control programme, have been very effective in reducing survival and reproduction of this weed. There are two terpene chemotypes of M. quinquenervia; one rich in the sesquiterpene E-nerolidol whereas the other is rich in viridiflorol. Viridiflorol is a strong feeding deterrent for the melaleuca weevil and retards larval development. The larvae therefore avoid the viridiflorol-rich chemotype, in contrast, female melaleuca psyllids prefer to oviposit on these leaves. To identify the molecular basis of these preferences, we isolated and characterised two terpene synthases from the viridiflorol-rich chemotype, both of which utilise farnesyl pyrophosphate and have the same product profile. Chemotypic variation in terpenes in M. quinquenervia is under strong genetic control and the reproductive potential of each chemotype is limited by a different insect. These insects could, therefore, be selective agents for the maintenance of chemotypic variation in M. quinquenervia.

Functional and evolutionary relationships between terpene synthases from Australian Myrtaceae

Myrtaceae is one of the chemically most variable and most significant essential oil yielding plant families. Despite an abundance of chemical information, very little work has focussed on the biochemistry of terpene production in these plants. We describe 70 unique partial terpene synthase transcripts and eight full-length cDNA clones from 21 myrtaceous species, and compare phylogenetic relationships and leaf oil composition to reveal clades defined by common function. We provide further support for the correlation between function and phylogenetic relationships by the first functional characterisation of terpene synthases from Myrtaceae: a 1,8-cineole synthase from Eucalyptus sideroxylon and a caryophyllene synthase from Eucalyptusdives.

Prevalence of diabetes in a large, nationally representative population sample in Hungary

We examined the prevalence of diabetes in a large, Hungarian, nationally representative adult population sample. The overall prevalence of diabetes was 6.2% (95% CI: 5.7-6.6). Increasing age and body mass index (BMI), male gender, physical inactivity, lower self-reported financial status, hypertension and non-smoking were independently associated with diabetes.

A molecular perspective on terpene variation in Australian Myrtaceae

The terpenoid-dominated essential oils in Australian Myrtaceae mediate many ecological interactions and are important industrially. Of all the significant essential oil-producing families, Myrtaceae is the only one for which there is no molecular information on terpene biosynthesis. Here we summarise available knowledge on terpene biosynthesis and its relevance to the Myrtaceae to provide a foundation for ecological and genetic studies of chemical diversity. There are several steps in the terpene biosynthesis pathway that have potential for influencing the oil yield, profile and composition of leaf oils in Myrtaceae. The biochemical steps that influence oil yield in Myrtaceae probably occur in the steps of the pathway leading up to the synthesis of the terpene backbone. Qualitative differences in oil profiles are more likely to be due to variation in terpene synthases and terpene-modifying enzymes. Most of the information on molecular variation in terpene biosynthesis is based on the analysis of artificially derived mutants but Australian Myrtaceae can provide examples of the same mechanisms in an ecological context.

Restless legs syndrome, insomnia, and quality of life after renal transplantation

OBJECTIVE

Restless legs syndrome (RLS) is associated with insomnia and impaired quality of life (QoL) in patients on maintenance dialysis; however, no information has been published on the association of RLS and QoL in kidney-transplanted patients. In a cross-sectional study, we analyzed the complex relationship between RLS, insomnia, and health-related QoL in kidney-transplanted patients.

METHODS

In a cross-sectional survey at a single transplant center, 1067 patients were invited to participate. Complete data set was available from 785 kidney-transplanted patients. The RLS Questionnaire and the Athens Insomnia Scale were used to assess the prevalence of RLS and insomnia, respectively. QoL was measured using the Kidney Disease QoL-SF Questionnaire.

RESULTS

Patients with RLS were three times more likely to have insomnia than patients without RLS (29% vs. 9%, P=.001), and the presence of RLS was a significant and independent predictor of insomnia in multivariate analysis. The presence of RLS was independently associated with impaired health-related QoL along several QoL domains after statistical adjustment for clinical and sociodemographic covariables. Importantly, this association remained significant even after adjusting for insomnia for some QoL domains.

CONCLUSION

RLS is associated with poor sleep, increased odds for insomnia, and impaired QoL in kidney-transplanted patients. Our results suggest that both sleep-related and sleep-independent factors may contribute to the association of RLS and QoL.

Moderate exercise and bright light treatment in overweight and obese individuals

OBJECTIVE

Increased physical activity is important given the concern over the growing rates of obesity. The aim of this study is to conduct a controlled investigation of the effects of bright light therapy and exercise on weight loss and body composition in overweight and obese individuals.

RESEARCH METHODS AND PROCEDURES

Twenty-five overweight and obese subjects were assigned to 6 weeks of moderate exercise with or without bright light treatment. Outcome measure included changes in body mass and body composition and ratings of mood, seasonality, and sleep.

RESULTS

Body weight decreased significantly with exercise in subjects in the light and non-light treatment groups, but the change was not significantly different between the groups. Similar results were found for BMI. With exercise, body fat decreased significantly only in the light treatment group. There was a significant effect of the interaction of group by time on body fat composition, but the group by time interaction failed to reach statistical significance for body weight and BMI. Mood scores improved significantly with exercise in the light group, but no significant changes were noted regarding sleep.

DISCUSSION

This preliminary study is the first to show that addition of bright light treatment to a 6-week moderate exercise program can alter body composition by significantly reducing body fat. The reduction in body fat mass is of particular importance, because visceral fat has been particularly implicated as a major factor in the development of the metabolic syndrome. This study is an important step toward finding ways to maximize the effects of exercise.

Evaluation of Meditech ABPM-04 ambulatory blood pressure measuring device according to the British Hypertension Society protocol

BACKGROUND

The use of ambulatory blood pressure measuring devices has become widespread in the diagnosis of hypertension. The accuracy of the device is fundamental for the diagnosis and treatment of the disease.

OBJECTIVE

Internationally accepted validation of the newest ambulatory blood pressure measuring device, the ABPM-04 prototype, manufactured by Meditech Ltd.

PATIENTS AND METHODS

Validation was carried out by assessing 94 outpatients, according to the British Hypertension Society protocol.

RESULTS

The test device achieved grade B on the scale defined in the British Hypertension Society protocol, for both systolic and diastolic blood pressure. The mean and standard deviation of the difference between measurements of the test device and the mercury standard for both systolic and diastolic blood pressure were within the recommendations of the Association for the Advancement of Medical Instrumentation.

CONCLUSION

The present study demonstrates that the Meditech ABPM-04 ambulatory blood pressure measuring device complies with the above mentioned requirements, and thus can be recommended for clinical use.