Validation of actigraphy sleep metrics in children aged 8 to 16 years: considerations for device type, placement and algorithms

BACKGROUND

Actigraphy is often used to measure sleep in pediatric populations, despite little confirmatory evidence of the accuracy of existing sleep/wake algorithms. The aim of this study was to determine the performance of 11 sleep algorithms in relation to overnight polysomnography in children and adolescents.

METHODS

One hundred thirty-seven participants aged 8-16 years wore two Actigraph wGT3X-BT (wrist, waist) and three Axivity AX3 (wrist, back, thigh) accelerometers over 24-h. Gold standard measures of sleep were obtained using polysomnography (PSG; Embletta MPRPG, ST + Proxy and TX Proxy) in the home environment, overnight. Epoch by epoch comparisons of the Sadeh (two algorithms), Cole-Kripke (three algorithms), Tudor-Locke (four algorithms), Count-Scaled (CS), and HDCZA algorithms were undertaken. Mean differences from PSG values were calculated for various sleep outcomes.

RESULTS

Overall, sensitivities were high (mean ± SD: 91.8%, ± 5.6%) and specificities moderate (63.8% ± 13.8%), with the HDCZA algorithm performing the best overall in terms of specificity (87.5% ± 1.3%) and accuracy (86.4% ± 0.9%). Sleep outcome measures were more accurately measured by devices worn at the wrist than the hip, thigh or lower back, with the exception of sleep efficiency where the reverse was true. The CS algorithm provided consistently accurate measures of sleep onset: the mean (95%CI) difference at the wrist with Axivity was 2 min (-6; -14,) and the offset was 10 min (5, -19). Several algorithms provided accurate measures of sleep quantity at the wrist, showing differences with PSG of just 1-18 min a night for sleep period time and 5-22 min for total sleep time. Accuracy was generally higher for sleep efficiency than for frequency of night wakings or wake after sleep onset. The CS algorithm was more accurate at assessing sleep period time, with narrower 95% limits of agreement compared to the HDCZA (CS:-165 to 172 min; HDCZA: -212 to 250 min).

CONCLUSION

Although the performance of existing count-based sleep algorithms varies markedly, wrist-worn devices provide more accurate measures of most sleep measures compared to other sites. Overall, the HDZCA algorithm showed the greatest accuracy, although the most appropriate algorithm depends on the sleep measure of focus.

Angiogenic markers and maternal echocardiographic indices in women with hypertensive disorders of pregnancy

OBJECTIVE

The maternal cardiovascular system of women with hypertensive disorders of pregnancy (HDP) can be impaired, with higher rates of left ventricular (LV) remodeling and diastolic dysfunction compared to those with normotensive pregnancy. The primary objective of this prospective study was to correlate cardiac indices obtained by transthoracic echocardiography (TTE) and circulating angiogenic markers, such as soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF).

METHODS

In this study, 95 women with a pregnancy complicated by HDP and a group of 25 with an uncomplicated pregnancy at term underwent TTE and blood tests to measure sFlt-1 and PlGF during the peripartum period (before delivery or within a week of giving birth). Spearman's rank correlation was used to derive correlation coefficients between biomarkers and cardiac indices in the HDP and control populations.

RESULTS

The HDP group included 61 (64.2%) pre-eclamptic patients and, among them, 42 (68.9%) delivered before 37 weeks' gestation. Twelve women with HDP (12.6%) underwent blood sampling and TTE after delivery, and, as they showed significantly lower levels of angiogenic markers, they were excluded from the analysis. There was a correlation between sFlt-1 and LV mass index (LVMI) (r = 0.246; P = 0.026) and early diastolic mitral inflow velocity (E) and early diastolic mitral annular velocity (e') ratio (r = 0.272; P = 0.014) in the HDP group (n = 83), while in the controls, sFlt-1 showed a correlation with relative wall thickness (r = 0.409; P = 0.043), lateral e' (r = -0.562; P = 0.004) and E/e' ratio (r = 0.417; P = 0.042). PlGF correlated with LVMI (r = -0.238; P = 0.031) in HDP patients and with lateral e' (r = 0.466; P = 0.022) in controls. sFlt-1/PlGF ratio correlated with lateral e' (r = -0.568; P = 0.004) and E/e' ratio (r = 0.428; P = 0.037) in controls and with LVMI (r = 0.252; P = 0.022) and E/e' ratio (r = 0.269; P = 0.014) in HDP.

CONCLUSIONS

Although the current data are not able to infer causality, they confirm the intimate relationship between the maternal cardiovascular system and angiogenic markers that are used both to diagnose and indicate the severity of HDP. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Catheter-associated bloodstream infection in patients with cancer: comparison of left- and right-sided insertions

BACKGROUND

There is limited research on the relationship between side of insertion of central venous catheter (CVAD) and bloodstream infection risk in patients with cancer.

AIM

To conduct an exploratory analysis of data from a randomized control trial (RCT) and data from a prospective cohort study to compare infection rates for right- and left-sided insertions.

METHODS

The study populations were patients aged >14 years with cancer from two tertiary hospitals in Brisbane, Australia. The primary endpoint was catheter-associated bloodstream infection (CABSI) adjudicated by blinded assessors. For the RCT, randomized intention-to-treat comparisons were conducted between left- and right-side allocated insertion for early (≤14 days) and late (>14 days) infection using Cox proportional hazards regression. The RCT data were also combined with cohort study data collected from one of the hospitals prior to the RCT and non-randomized comparisons conducted between left- and right-sided insertions.

FINDINGS

In 634 randomly allocated CVADs there were 141 CABSIs. Analysis showed strong evidence of right-side allocated insertions having an increased risk of early infection by 2.5 times (95% confidence interval (CI): 1.3-4.7); however, there was no evidence of increased risk for late infection (hazard ratio: 1.06; 95% CI: 0.71-1.59). Results from analysis of the RCT and cohort study data combined (2786 CVADs and 385 CABSIs) were similar.

CONCLUSION

There appears to be an increased risk of CABSI in patients with cancer for CVAD inserted into the right-side for around two weeks after line insertion. The mechanism underpinning the increased risk is unknown.

104 Oral Sodium Bicarbonate Therapy for Older Patients with Chronic Kidney Disease and Low-Grade Acidosis: The BiCARB Randomised Controlled Trial

Background

Oral sodium bicarbonate is often used to treat metabolic acidosis in older people with advanced chronic kidney disease, but evidence is lacking on whether this provides a net gain in health or quality of life.

Methods

We conducted a multicentre, parallel group, double-blind, placebo-controlled randomised trial. Adults aged 60 years and over with category 4 or 5 chronic kidney disease, not on dialysis, with serum bicarbonate concentrations <22 mmol/L were recruited from 27 UK centres. Participants were randomised 1:1 to oral sodium bicarbonate or matching placebo. The primary outcome was the between-group difference in the Short Physical Performance Battery at 12 months, adjusted for baseline. Other key outcome measures included generic and disease-specific health-related quality of life, anthropometry, physical performance, renal function, adverse events including commencement of renal replacement therapy, and health economic analysis.

Results

We randomised 300 participants, mean age 74 years; 86 (29%) were female. Mean baseline estimated GFR was 19 ml/min/1.73m2. Study medication adherence was 73% in both groups. No significant treatment effect was evident for the primary outcome of the between-group difference in the Short Physical Performance Battery at 12 months (-0.4 points; 95% CI -0.9 to 0.1, p=0.15). No significant treatment benefit was seen for any of the secondary outcomes. Adverse events were more frequent in the bicarbonate arm (457 versus 400). Time to commencing renal replacement therapy was similar in both groups (HR 1.22, 95% CI 0.74 to 2.02, p=0.43). Health economic analysis showed lower quality of life and higher costs in the bicarbonate arm at one year (£1234 vs £807); placebo dominated bicarbonate under all sensitivity analyses for incremental cost-effectiveness.

Conclusions

Oral sodium bicarbonate did not improve a wide range of health measures in this trial, and is unlikely to be cost-effective for use in the UK NHS in this patient group.

Determination of Semicarbazide in Fresh Egg and Whole Egg Powder by Liquid Chromatography/Tandem Mass Spectrometry: Interlaboratory Validation Study

An interlaboratory validation study was conducted according to harmonized protocols to evaluate the effectiveness of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the determination of semicarbazide (SEM) in fresh whole egg and in an industrially processed whole egg powder. The sample was extracted with hydrochloric acid and derivatized with 2-nitrobenzaldehyde, with 1,2-[15N213C]SEM as the internal standard. The extract was neutralized and purified on a solid-phase extraction cartridge. SEM was determined by reversed-phase LC with detection by MS/MS. Five fresh egg samples, of which 3 were obtained from hens fed nitrofurazone (NFZ), one was spiked with SEM at 50 μg/kg and one was a blank sample, and 5 industrial whole egg powder samples, of which 3 were spiked with fresh whole egg from hens fed NFZ, one was spiked with SEM at 350 μg/kg, and one was a blank sample, were sent to 15 laboratories in 10 different European countries. Results were obtained from 12 participants. Average recoveries of SEM from the fresh egg and the egg powder samples were 105.3 and 121.3%, respectively. The relative standard deviation for repeatability (RSDr) ranged from 2.9 to 9.3%, and the relative standard deviation for reproducibility (RSDR) ranged from 22.5 to 38.1%. The method showed acceptable within- and between-laboratory precision for both matrixes, as evidenced by the HorRat values, at the target levels for the determination of SEM.

Determination of Semicarbazide in Baby Food by Liquid Chromatography/Tandem Mass Spectrometry: Interlaboratory Validation Study

An interlaboratory validation study funded by the European Commission, Directorate General for Health and Consumer Protection (DG SANCO), was conducted to evaluate the effectiveness of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the determination of semicarbazide (SEM) in different types of baby food at a possible future European regulatory limit (10 ng/g). The test portion of the sample was extracted with hydrochloric acid, and the analyte was derivatized with 2-nitrobenzaldehyde, with 1,2-[15N2, 13C] SEM as an internal standard. The extract was neutralized and then purified on a solid-phase extraction cartridge. The SEM was determined by reversed-phase LC with detection by MS/MS. Apple puree, rice pudding, and meat/vegetable meal baby food materials, spiked with SEM at levels of about 3, 10, and 30 ng/g, respectively, were sent to 20 laboratories in 12 different European countries, which submitted results from 17 participants. Recoveries ranged from 88.8 to 106.1%. Based on results for spiked samples (blind pairs at 3 levels), the relative standard deviations for repeatability (RSDr) ranged from 4.2 to 6.9% and the relative standard deviations for reproducibility (RSDR) ranged from 16.6 to 24.3%. The method showed acceptable within- and between-laboratory precision for all 3 matrixes, as evidenced by HorRat values, at the target levels for the determination of SEM.

Determination of Clopidol Residues in Chicken Tissues by Liquid Chromatography: Collaborative Study

Eighteen laboratories participated in a collaborative study on the determination of clopidol residues in chicken muscle tissues by liquid chromatography. Of these, results from 16 laboratories which rigorously followed the method were subjected to statistical analysis. The method performance was assessed by all participants using 14 samples of chicken muscle fortified at concentrations ranging from 0.1 to 5.0 mg/kg. In addition, 9 participants each reported results for 6 clopidol-incurred samples in chicken muscle. Test portions were extracted with acetonitrile, and the extracts were purified with alumina and anion exchange resin solid-phase extraction cartridges in sequence. Clopidol was separated by reversed-phase liquid chromatography and quantified at 270 nm. Average recoveries ranged from 81.8 to 85.4%, reproducibility relative standard deviation (RSDR) ranged from 11.9 to 22.6%, and repeatability relative standard deviation (RSDr) ranged from 9.9 to 15.1%. For clopidol-incurred samples at concentrations of 0.100–0.687 mg/kg, the mean determination value range was 0.099–0.659 mg/kg; RSDR was 12.6–19.8%, RSDr was 3.1–8.5%; and HORRAT values were 0.7–1.1. The accuracy and precision of the method are in conformity with the requirements specified by AOAC INTERNATIONAL. The method was adopted Official First Action in April 2003.

Consecutive aquatic jump-gliding with water-reactive fuel

Robotic vehicles that are capable of autonomously transitioning between various terrains and fluids have received notable attention in the past decade due to their potential to navigate previously unexplored and/or unpredictable environments. Specifically, aerial-aquatic mobility will enable robots to operate in cluttered aquatic environments and carry out a variety of sensing tasks. One of the principal challenges in the development of such vehicles is that the transition from water to flight is a power-intensive process. At a small scale, this is made more difficult by the limitations of electromechanical actuation and the unfavorable scaling of the physics involved. This paper investigates the use of solid reactants as a combustion gas source for consecutive aquatic jump-gliding sequences. We present an untethered robot that is capable of multiple launches from the water surface and of transitioning from jetting to a glide. The power required for aquatic jump-gliding is obtained by reacting calcium carbide powder with the available environmental water to produce combustible acetylene gas, allowing the robot to rapidly reach flight speed from water. The 160-gram robot could achieve a flight distance of 26 meters using 0.2 gram of calcium carbide. Here, the combustion process, jetting phase, and glide were modeled numerically and compared with experimental results. Combustion pressure and inertial measurements were collected on board during flight, and the vehicle trajectory and speed were analyzed using external tracking data. The proposed propulsion approach offers a promising solution for future high-power density aerial-aquatic propulsion in robotics.

Post-transplant lymphoproliferative disorder in paediatric patients: the Irish perspective-a single centre experience

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD) is a serious complication of both solid organ and haematopoietic stem cell transplantation in children. Its incidence has increased over the last decade as a result of more potent immunosuppressive regimens. Many treatments have been explored however optimal therapy remains controversial.

AIMS

We report on the diagnosis, treatment and outcome of ten patients who were diagnosed with PTLD in Our Lady's Hospital for Sick Children in Dublin between 2004 and 2015 inclusive.

METHODS

Data were collected by retrospective review of patient medical records.

RESULTS

9 out of ten of our patients are alive and disease free following treatment for PTLD with rituximab alone or in combination with chemotherapy.

CONCLUSION

The outcome of paediatric patients treated for PTLD at our institution is at least comparable to published international series and supports the use of rituximab ± low dose chemotherapy in the treatment of this malignancy.

Effect of intermittent vitamin D3 on vascular function and symptoms in chronic fatigue syndrome--a randomised controlled trial

BACKGROUND AND AIMS

Low 25-hydroxyvitamin D levels are common in patients with chronic fatigue syndrome; such patients also manifest impaired vascular health. We tested whether high-dose intermittent oral vitamin D therapy improved markers of vascular health and fatigue in patients with chronic fatigue syndrome.

METHODS AND RESULTS

Parallel-group, double-blind, randomised placebo-controlled trial. Patients with chronic fatigue syndrome according to the Fukuda (1994) and Canadian (2003) criteria were randomised to receive 100,000 units oral vitamin D3 or matching placebo every 2 months for 6 months. The primary outcome was arterial stiffness measured using carotid-femoral pulse wave velocity at 6 months. Secondary outcomes included flow-mediated dilatation of the brachial artery, blood pressure, cholesterol, insulin resistance, markers of inflammation and oxidative stress, and the Piper Fatigue scale. As many as 50 participants were randomised; mean age 49 (SD 13) years, mean baseline pulse wave velocity 7.8 m/s (SD 2.3), mean baseline office blood pressure 128/78 (18/12) mmHg and mean baseline 25-hydroxyvitamin D level 46 (18) nmol/L. 25-hydroxyvitamin D levels increased by 22 nmol/L at 6 months in the treatment group relative to placebo. There was no effect of treatment on pulse wave velocity at 6 months (adjusted treatment effect 0.0 m/s; 95% CI -0.6 to 0.6; p = 0.93). No improvement was seen in other vascular and metabolic outcomes, or in the Piper Fatigue scale at 6 months (adjusted treatment effect 0.2 points; 95% CI -0.8 to 1.2; p = 0.73).

CONCLUSION

High-dose oral vitamin D3 did not improve markers of vascular health or fatigue in patients with chronic fatigue syndrome.

TRIAL REGISTRATION

www.controlled-trials.com, ISRCTN59927814.

Exclusive breastfeeding and its effect on growth of Malawian infants: results from a cross-sectional study

BACKGROUND

For the optimal nutrition of children under 2 years of age, it is considered important that they be exclusively breastfed for the first 6 months before being given complementary food.

AIMS AND OBJECTIVES

A cross-sectional nutritional baseline survey was undertaken in 2011 in the Kasungu and Mzimba Districts of Malawi to assess the nutritional status of children under 2 years of age and its determinants in order to prepare a nutrition education intervention programme. The intention of this study was to assess the nutritional status of infants aged 0-<6 months with regard to food intake.

METHODS

Interviews were conducted on randomly selected families with children under 2 years; anthropometric measurements were obtained from mothers and their children. Only infants between 0 and <6 months were selected for analysis (n  =  196). An ANCOVA test was performed on age of the infant with mothers' height and weight as covariates.

RESULTS

Prevalence of stunting (infants' length-for-age Z-score (LAZ) <-2SD) was 39%, wasting (WLZ <-2SD) 2%, and underweight (WAZ <-2SD) 13%. Of the infants under 6 months, 43% were exclusively breastfed. Predominant breastfeeding and mixed breastfeeding were less common (21% and 36%, respectively). The ANCOVA confirmed the association between exclusive breastfeeding and LAZ and WAZ: exclusively breastfed infants had a higher mean (SE) LAZ (-1.13, 0.12) and WAZ (-0.41, 0.13) than infants not being exclusively breastfed (-1.59, 0.11, and -0.97, 0.11, respectively). There was no overall significant association between breastfeeding practice and WLZ.

CONCLUSION

Exclusive breastfeeding of infants under 6 months is associated with higher mean LAZ and WAZ. Promotion of exclusive breastfeeding in low-income countries is important in preventing growth retardation.

Application of the k0 method in neutron activation analysis and in prompt gamma activation analysis

The k0 method is a highly successful standardization method developed for Neutron Activation Analysis (NAA), later also introduced in Prompt Gamma Activation Analysis (PGAA). After the careful calibration of the irradiation and counting facilities, the k0 method makes the use of elemental standards unnecessary. Masses of the components are determined relative to the flux monitor, or, in the case of PGAA, to other known components of the sample. The development of the method is summarized in this review together with the description of methods implemented at different laboratories. The activities carried out in the laboratories of the authors are described as examples for the successful implementation of the k0 approach to activation analysis.

Intensive care unit experience of haemopoietic stem cell transplant patients

BACKGROUND

Previous research at our institution (1988-1998) established an intensive care unit (ICU) and hospital mortality between 70% and 80% in haemopoietic stem cell transplant (HSCT) patients requiring ICU admission.

AIMS

This study explored mortality in a more contemporary cohort while comparing outcomes to published literature and our previous experience.

METHODS

Retrospective chart review of HSCT patients admitted to ICU between December 1998 and June 2008.

RESULTS

Of 146 admissions, 53% were male, with a mean age of 44 years, an Acute Physiologic and Chronic Health Evaluation II score of 28 and Sepsis Organ Failure Assessment score of 11. Fifty-six per cent had graft versus host disease (GVHD), with respiratory failure (67%) being the most common admission diagnosis. All but one received mechanical ventilation. The ICU and hospital mortality were 42% (72% 1988-1998 cohort) and 64% (82% 1998-1998 cohort) respectively. The 6- and 12-month survivals were 29% and 24% respectively for the 1998-2008 cohort. Dying in ICU was independently predicted by fungal infection (P= 0.02) and early onset of organ failure (P < 0.001), while GVHD (P= 0.04) predicted survival. Mortality at 12 months was independently predicted by the acute physiology score (P= 0.002), increasing number of organ failures (P= 0.001), and cytomegalovirus positive serology (P= 0.005), while blood stream infection (P= 0.003), an antibiotic change on admission to the ICU (P= 0.007) and a diagnosis of non-Hodgkin lymphoma (P= 0.02) predicted survival.

CONCLUSION

Our study found that acute admission of HSCT patients to the ICU is associated with improved survival compared to our previous experience, with organ failure progression a strong predictor of ICU outcome, and specific disease characteristics contributing to long-term survival.

Rosuvastatin might have an effect on C-reactive protein but not on rheumatoid disease activity: Tayside randomized controlled study

The aim of this study was to study the effects of rosuvastatin in patients with rheumatoid arthritis (RA) looking at the C-reactive protein (CRP), interleukin-6 (IL-6) and joint disease activity. Fifty RA patients were randomized in a double-blind placebo-controlled trial to receive either 10 mg of rosuvastatin or placebo as an adjunct to existing disease-modifying antirheumatic therapy. Patients were followed up for a six-month period. Measurements were done at baseline and six months. CRP and IL-6 were measured in the blood. RA disease activity was measured using disease activity score based on 28 joint counts (DAS 28). When analysing from baseline to six months there was no difference between the rosuvastatin and placebo groups in rheumatoid disease activity (–0.01; standard deviation [SD], 1.08; and +0.18; SD, 0.95; respectively; P value 0.509). There was a trend towards improvement in CRP in the rosuvastatin group (–3.23; SD, 18.18) compared with the placebo group (+17.43; SD, 38.03); P value, 0.161. IL-6 showed a trend towards worsening in the rosuvastatin group (+0.15; SD, 1.09) compared with placebo (–0.73; SD, 1.4); P value, 0.054. These data show that rosuvastatin with might decrease the CRP independent to IL-6 in patients with RA but does not improve the overall rheumatoid disease activity.

Surveillance study of a number of synthetic and natural growth promoters in bovine muscle samples using liquid chromatography-tandem mass spectrometry

A simple, new method permitting the simultaneous determination and confirmation of trace residues of 24 different growth promoters and metabolites using liquid chromatography-mass spectrometry was developed and validated. The compounds were extracted from bovine tissue using acetonitrile; sodium sulphate was also added at this stage to aid with purification. The resulting mixture was then evaporated to approximately 1 ml and subsequently centrifuged at high speed and an aliquot injected onto the LC-MS/MS system. The calculated CCα values ranged between 0.11 and 0.46 µg kg(-1); calculated CCβ were in the range 0.19-0.79 µg kg(-1). Accuracy, measurement of uncertainty, repeatability and linearity were also determined for each analyte. The analytical method was applied to a number of bovine tissue samples imported into Ireland from third countries. Levels of progesterone were found in a number of samples at concentrations ranging between 0.28 and 30.30 µg kg(-1). Levels of alpha- and beta-testosterone were also found in a number of samples at concentrations ranging between 0.22 and 8.63 µg kg(-1) and between 0.16 and 2.08 µg kg(-1) respectively.

Juvenile pancreatic atrophy in Greyhounds: 12 cases (1995-2000)

BACKGROUND

This study describes compound failure of the endocrine and exocrine pancreas in Greyhounds, a condition that has not been reported in the veterinary literature.

OBJECTIVE

To describe the clinical and pathologic findings in 12 Greyhounds with juvenile pancreatic atrophy.

ANIMALS

Ten Greyhounds presented for necropsy examination and 2 sibling Greyhounds presented for clinical evaluation before necropsy, all with a history of small-bowel diarrhea.

PROCEDURES

Retrospective study of laboratory and pathologic findings in 12 Greyhounds, including serum trypsin-like immunoreactivity assays, oral glucose tolerance testing, and serum anti-insulin antibody concentrations.

RESULTS

Gross pancreatic atrophy was found in all 12 dogs. Histopathologic lesions were found in both the endocrine and exocrine pancreas and included acinar cell apoptosis, zymogen granule loss, cytoplasmic clearing or vacuolar change, lobular atrophy, islet loss, and lymphocytic or lymphoplasmacytic pancreatitis. Antemortem test results on the 2 Greyhound puppies indicated concurrent exocrine pancreatic insufficiency (EPI) and insulin-dependent diabetes mellitus (IDDM).

CONCLUSIONS AND CLINICAL IMPORTANCE

Compound failure of the exocrine and endocrine pancreas is rarely reported in dogs and neither disease is well recognized in the Greyhound. This condition is of potential economic importance to the Greyhound racing industry.

Plasma IL-6, its soluble receptors and F2-isoprostanes at rest and during exercise in chronic fatigue syndrome

The aim of the current study was to investigate the levels of interleukin-6 (IL-6), its soluble receptors (sIL-6R and sgp130) and F(2)-isoprostanes, at rest and during exercise, in patients with chronic fatigue syndrome (CFS). Six male CFS patients and six healthy controls performed an incremental exercise test to exhaustion and a submaximal exercise bout to exhaustion. Blood samples taken in the submaximal test at rest, immediately post-exercise and 24 h post-exercise were analyzed for IL-6, sIL-6R, sgp130 and F(2)-isoprostanes. A further 33 CFS and 33 healthy control participants gave a resting blood sample for IL-6 and sIL-6R measurement. During the incremental exercise test only power output at the lactate threshold was lower (P<0.05) in the CFS group. F(2)-isoprostanes were higher (P<0.05) in CFS patients at rest and this difference persisted immediately and 24 h post-exercise. The exercise study found no differences in IL-6, sIL-6R or sgp130 at any time point between groups. In the larger resting group, there were no differences in IL-6 and sIL-6R between CFS and control groups. This investigation has demonstrated that patients with CFS do not have altered plasma levels of IL-6, sIL-6R or sgp130 either at rest or following exercise. F(2)-isoprostanes, however, were consistently higher in CFS patients.

Improvement in systemic endothelial condition following amputation in patients with critical limb ischemia

AIM

Most patients with critical limb ischemia (CLI) have co-existing coronary heart disease, which is the main cause of their increased mortality. Peripheral ischemic tissue produces circulating toxic molecules, which may worsen endothelial function systemically and contribute to the general atherosclerotic process within the body. We looked at whether markers of endothelial function improve after amputation of the ischemic limb, when this potential source of toxins has been removed.

METHODS

We measured blood levels of vascular endothelial growth factor (VEGF), homocysteine, endothelin-1, vascular cell adhesion molecule-1, E-selectin, thrombomodulin and von Willebrand factor (vWF) in 40 patients with CLI. We also assessed peripheral microvascular function in forearm skin by measuring responses to iontophoresis of acetylcholine and sodium nitroprusside. The measurements were repeated 6 months after amputation.

RESULTS

We found abnormally high levels of endothelial products in the patients, and 6 months later VEGF and vWF had both reduced significantly from previous values (by 70% and 40%, respectively; P<0.01 in both cases).

CONCLUSION

Improvements in these two markers after amputation are consistent with the hypothesis that peripheral ischemic tissue has a systemic effect on the vascular endothelium and may contribute to the progression of coronary heart disease in patients with CLI.

Intensive insulin therapy improves endothelial function and microvascular reactivity in young people with type 1 diabetes

AIMS/HYPOTHESIS

Macrovascular disease is an important cause of the increased morbidity and mortality rates associated with type 1 diabetes, and this vascular impairment begins in childhood. The aim of this study was to determine whether introducing intensive diabetes management [intensive insulin therapy (IIT) and 'Sweet Talk' text-messaging support] produces measurable improvements in endothelial function.

METHODS

One hundred and twenty-six patients fulfilled the eligibility criteria (type 1 diabetes for >1 year; on conventional insulin therapy (CIT); aged between 8 and 18 years), of whom 92 enrolled. Patients were randomised to group 1, CIT only (n=28); group 2, CIT and Sweet Talk (n=33); or group 3, IIT and Sweet Talk (n=31). Vascular assessments (including measures of endothelial damage, activation, dysfunction and oxidative stress) and HbA1c were performed at baseline and repeated after 12 months of the study.

RESULTS

Glycaemic control deteriorated in patients on CIT, but improved significantly in patients allocated to IIT (p=0.007). IIT was associated with significantly greater improvements in E-selectin (p<0.0001) than CIT (group 1, p=0.026 and group 2, p=0.053). Vascular responses to acetylcholine improved in patients on IIT (p=0.017), but not in patients receiving CIT. These changes were all independent of HbA1c level.

CONCLUSIONS/INTERPRETATION

IIT appears to be associated with improvements in vascular markers, independently of changes in HbA1c, suggesting that IIT may confer vascular protection in addition to improving glycaemic control.

Diagnostic and prognostic utility of the serum free light chain assay in patients with AL amyloidosis

BACKGROUND

Organ dysfunction in AL amyloidosis is related to the production and deposition of amyloidogenic monoclonal light chains. These pathological light chains can now be quantified using the recently developed serum free light chain assay.

METHODS

We retrospectively reviewed 31 patients with AL amyloidosis to determine the frequency of abnormal free light chain assay results at diagnosis and whether changes in the serum free light chain assay predict outcome after therapy.

RESULTS

An abnormal free light chain assay was found in 30 of 31 patients (97%) at the time of diagnosis. In the subset of our patients who received treatment for AL amyloidosis, a >50% reduction of the pathological free light chain following treatment was shown to predict improved overall survival. In our series of analyses, achievement of greater magnitudes of reduction of the free light chain result did not appear to provide additional prognostic information, nor did the baseline free light chain result predict outcome.

CONCLUSION

Our findings support the use of the free light chain assay in the diagnostic work-up of patients with suspected AL amyloidosis, and also as a sensitive biomarker of response to therapy.

A prospective multicenter trial of peripheral blood stem cell sibling allografts for acute myeloid leukemia in first complete remission using fludarabine-cyclophosphamide reduced intensity conditioning

The role of allogeneic transplantation in patients with de novo acute myeloid leukemia in first complete remission (AML-CR1) is controversial. Aiming to preserve a graft-versus-leukemia effect, but minimize morbidity and mortality from conditioning-related toxicity and graft-versus-host disease (GVHD), we conducted a prospective multicenter study of reduced-intensity conditioning (RIC) as preparation for peripheral blood stem cell sibling allografts in patients with intermediate or poor risk AML-CR1. Conditioning consisted of fludarabine 125 mg/m(2) and cyclophosphamide 120 mg/kg. Thirty-four patients were transplanted with a median age of 45 years; 85% had intermediate risk cytogenetics. Early toxicity was minimal. The overall incidence of grade II-IV acute GVHD was low (21%), but the 3 patients (9%) who developed grade IV GVHD died. Donor T cell chimerism was rapid and generally complete, but complete myeloid chimerism was delayed. Thirteen patients (38%) relapsed, 12 within a year of transplant. The estimated disease-free survival (DFS) and overall survival at 2 years was 56% (95% confidence interval [CI] 39%-71%) and 68% (95% CI 50%-81%), respectively. The incidence of extensive chronic GVHD (cGVHD) was low (24% of surviving patients at 12 months) and most survivors had an excellent performance status. These observations justify a prospective comparison of RIC versus myeloablative conditioning allografts for AML-CR1.

Food variety and dietary diversity scores in children: are they good indicators of dietary adequacy?

Objective

To assess whether a food variety score (FVS) and/or a dietary diversity score (DDS) are good indicators of nutrient adequacy of the diet of South African children.

Methods

Secondary data analyses were undertaken with nationally representative data of 1–8-year-old children (n = 2200) studied in the National Food Consumption Study in 1999. An average FVS (mean number of different food items consumed from all possible items eaten) and DDS (mean number of food groups out of nine possible groups) were calculated. A nutrient adequacy ratio (NAR) is the ratio of a subject's nutrient intake to the estimated average requirement calculated using the Food and Agriculture Organization/World Health Organization (2002) recommended nutrient intakes for children. The mean adequacy ratio (MAR) was calculated as the sum of NARs for all evaluated nutrients divided by the number of nutrients evaluated, expressed as a percentage. MAR was used as a composite indicator for micronutrient adequacy. Pearson correlation coefficients between FVS, DDS and MAR were calculated and also evaluated for sensitivity and specificity, with MAR taken as the ideal standard of adequate intake. The relationships between MAR and DDS and between anthropometric Z-scores and DDS were also evaluated.

Results

The children had a mean FVS of 5.5 (standard deviation (SD) 2.5) and a mean DDS of 3.6 (SD 1.4). The mean MAR (ideal = 100%) was 50%, and was lowest (45%) in the 7–8-year-old group. The items with the highest frequency of consumption were from the cereal, roots and tuber group (99.6%), followed by the ‘other group’ (87.6%) comprising items such as tea, sugar, jam and sweets. The dairy group was consumed by 55.8%, meat group by 54.1%, fats by 38.9%, other vegetables by 30.8%, vitamin-A-rich by 23.8%, other fruit by 22%, legumes and nuts by 19.7% and eggs by 13.3%. There was a high correlation between MAR and both FVS (r = 0.726; P < 0.0001) and DDS (r = 0.657; P < 0.0001), indicating that either FVS or DDS can be used as an indicator of the micronutrient adequacy of the diet. Furthermore, MAR, DDS and FVS showed significant correlations with height-for-age and weight-for-age Z-scores, indicating a strong relationship between dietary diversity and indicators of child growth. A DDS of 4 and an FVS of 6 were shown to be the best indicators of MAR less than 50%, since they provided the best sensitivity and specificity.

Conclusion

Either FVS or DDS can be used as a simple and quick indicator of the micronutrient adequacy of the diet.

Endothelin-1 levels predict 3-year survival in patients who have amputation for critical leg ischaemia

BACKGROUND

Most patients with critical leg ischaemia (CLI) have co-existing coronary heart disease, which is the main cause of their increased mortality rate. The aim of this study was to investigate whether any markers of endothelial function could predict death in these patients.

METHODS

In a cohort of 39 patients with CLI who were scheduled for lower-limb amputation, blood levels of vascular endothelial growth factor, homocysteine, endothelin (ET) 1, von Willebrand factor and vascular cell adhesion molecule 1 were measured, as well as forearm vascular responses to the endothelium-dependent vasodilator acetylcholine.

RESULTS

Levels of ET-1 were significantly higher in patients who subsequently died within 3 years than in those who were still alive (P = 0.002) and Cox proportional hazards regression analysis demonstrated that ET-1 was an independent predictor of all-cause mortality:hazard ratio 3.53 (95 per cent confidence interval (c.i.) 1.29 to 9.70; P = 0.007) and cardiovascular mortality:hazard ratio 4.15 (95 per cent c.i. 1.30 to 13.23); P = 0.014.

CONCLUSION

ET-1 was an independent predictor of death in these patients with CLI.

Lack of apoptosis of Sezary cells in the circulation following oral bexarotene therapy

BACKGROUND

Apoptosis of malignant cells has been suggested as an important mechanism of the action of bexarotene in the treatment of cutaneous T-cell lymphoma (CTCL).

OBJECTIVES

Our purpose was to examine the in vivo and in vitro responses of patients with Sézary syndrome treated with oral bexarotene and assess them for apoptosis of the Sézary cells.

METHODS

Six patients with CTCL with circulating Sézary cells, participating in a clinical trial of oral bexarotene (300 mg m(-2) daily) were included in the study. Peripheral blood from the patients was analysed for in vivo and in vitro apoptosis.

RESULTS

None of the six patients demonstrated in vivo apoptosis. In vitro apoptosis of Sézary cells was demonstrated in one patient following exogenous bexarotene.

CONCLUSIONS

Apoptosis is not detectable in the circulation of patients with Sézary syndrome treated with bexarotene.