Adherence and long-term outcomes of therapy in paediatric patients in Greece using the easypod™ electromechanical device for growth hormone treatment: The phase IV multicentre easypod™ connect observational study (ECOS)

BACKGROUND

The easypod™ injection device allows automatic recording and transmission of adherence data from patients receiving recombinant human growth hormone (rhGH [Saizen®]) to treat growth disorders. This analysis aimed to evaluate the adherence of Saizen® administered via easypod™ in a cohort of Greek patients from the easypod™ connect observational study (ECOS).

METHODS

The phase IV, open-label, multicentre, observational, and longitudinal ECOS study (EMR200104-520, NCT01363674) enrolled patients treated for a minimum of 6 months and up to 3 years. The primary endpoint was to assess the mean rate of adherence to treatment at different time points, where good adherence was defined as ≥85%. Change in height, height standard deviation score (SDS), height velocity and height velocity SDS were evaluated after 1 year of treatment as secondary endpoints, together with the impact of adherence on growth outcomes using the Spearman's product moment.

RESULTS

Of the 180 patients enrolled, 86 were included in the analysis. The mean adherence to Saizen®, as recorded via easypod™, was high at each individual time point, and was maintained at 95.5% after 1 year of treatment. Clinically meaningful positive changes were also noted for all of the secondary endpoints (median increase in height = 7.25 cm, height SDS = 0.32, median height velocity = 7.62 cm/year and height velocity SDS = 1.65). However, no significant correlation was noted between adherence and growth outcomes.

CONCLUSIONS

rhGH replacement therapy using Saizen® with easypod™ led to full compliance to the treatment in a representative Greek population from ECOS, and provided additional insights on how the easypod™ device can assist physicians in monitoring adherence and help to optimise linear growth in paediatric patients with growth disorders.

Wide dynamic range magnetic field cycler: Harnessing quantum control at low and high fields

We describe the construction of a fast field cycling device capable of sweeping a 4-order-of-magnitude range of magnetic fields, from ∼1 mT to 7 T, in under 700 ms, and which is further extendable to a 1 nT-7 T range. Central to this system is a high-speed sample shuttling mechanism between a superconducting magnet and a magnetic shield, with the capability to access arbitrary fields in between with high resolution. Our instrument serves as a versatile platform to harness the inherent dichotomy of spin dynamics on offer at low and high fields-in particular, the low anisotropy, fast spin manipulation, and rapid entanglement growth at low field as well as the long spin lifetimes, spin specific control, and efficient inductive measurement possible at high fields. Exploiting these complementary capabilities in a single device opens up applications in a host of problems in quantum control, sensing, and information storage, besides in nuclear hyperpolarization, relaxometry, and imaging. In particular, in this paper, we focus on the ability of the device to enable low-field hyperpolarization of ¹³C nuclei in diamond via optically pumped electronic spins associated with nitrogen vacancy defect centers.

Monolithic MACS micro resonators

Magic Angle Coil Spinning (MACS) aids improving the intrinsically low NMR sensitivity of heterogeneous microscopic samples. We report on the design and testing of a new type of monolithic 2D MACS resonators to overcome known limitations of conventional micro coils. The resonators' conductors were printed on dielectric substrate and tuned without utilizing lumped element capacitors. Self-resonance conditions have been computed by a hybrid FEM-MoM technique. Preliminary results reported here indicate robust mechanical stability, reduced eddy currents heating and negligible susceptibility effects. The gain in B1/P is in agreement with the NMR sensitivity enhancement according to the principle of reciprocity. A sensitivity enhancement larger than 3 has been achieved in a monolithic micro resonator inside a standard 4mm rotor at 500MHz. These 2D resonators could offer higher performance micro-detection and ease of use of heterogeneous microscopic substances such as biomedical samples, microscopic specimens and thin film materials.

Double helix dipole design applied to magnetic resonance: a novel NMR coil

A new radio frequency coil design for NMR experiments is presented. The coil generates a magnetic field purely perpendicular to the longitudinal axis of the main magnet, and its sensitivity is higher than the traditional transversal resonators. This is achieved by adding the contribution of two tilted solenoid coils fed with opposite currents. The work presents the mathematical model for the new coil, numerical simulations performed to validate that model and a comparison with an equivalent saddle coil. The new design is tested experimentally in low- and high-field NMR experiments and compared with results obtained with equivalent saddle coils. The results lead to conclude that the new design provides better sensitivity than the transverse resonators commonly used in NMR.

Should we measure routinely oxidised and atherogenic dense low-density lipoproteins in subjects with type 2 diabetes?

Beyond low-density lipoprotein (LDL)-cholesterol concentrations, in recent years, several clinical studies have shown that both oxidised and small, dense LDL have a strong predictive role for the presence of vascular atherosclerosis. These two lipid parameters seem to have a synergistic impact on cardiovascular risk, with a greater importance in patients at higher-risk, such as those with type-2 diabetes. Increased levels of oxidised and small, dense LDL levels are a feature of diabetic dyslipidaemia, and small, dense LDL have been shown to be a good predictor of future cardiovascular events, at both univariate and multivariate analyses. On the other hand, although the association of oxidised LDL with surrogate markers of atherosclerosis is consistent, the correlation with hard clinical end points seems to be smaller. Yet, measurement of these two lipid parameters has not been widely used in daily practice because of the limited availability of clinical data and methodological problems: lack of availability of easy, cheap and reproducible essays for measurement of oxidised and, particularly, small, dense LDL has reduced their assessment in large clinical end-points trials. However, on the basis of available data, the therapeutic modulation of small, dense LDL is significantly associated with reduced cardiovascular risk, even after adjustment for confounding factors. In conclusion, the routine measurement of oxidised and small, dense LDL in patients with type-2 diabetes cannot be recommended in daily clinical practice so far; yet, their measurement is strongly encouraged to better understand their role on the cardiovascular risk of patients with type-2 diabetes.

New insights into the exercise intolerance of beta-thalassemia major patients

The purpose of our study was assessment of the relative contribution of the systems involved in blood gas exchange to the limited exercise capacity in patients with beta-thalassemia major (TM) using integrative cardiopulmonary exercise testing (CPET) with estimation of oxygen kinetics. The study consisted of 15 consecutive TM patients and 15 matched controls who performed spirometric evaluation, measurement of maximum inspiratory pressure (Pimax) and an incremental symptom-limited CPET on a cycle ergometer. Exercise capacity was markedly reduced in TM patients as assessed by peak oxygen uptake (pVO(2), mL/kg/min: 22.1+/-6.6 vs 33.8+/-8.3; P<0.001) and anaerobic threshold (mL/kg/min: 13.0+/-3.0 vs 18.7+/-4.6; P<0.001) compared with controls. No ventilatory limitation to exercise was noted in TM patients (VE/VCO(2) slope: 23.4+/-3.2 vs 27.8+/-2.6; P<0.001 and breathing reserve, %: 42.9+/-17.0 vs 29.5+/-12.0; P<0.005) and no difference in oxygen cost of work (peak VO(2)/WR, mL/min W: 12.2+/-1.7 vs 12.2+/-1.5; P=NS). Delayed recovery oxygen kinetics after exercise was observed in TM patients (VO(2)/t slope, mL/kg/min(2): 0.67+/-0.27 vs 0.93+/-0.23; P<0.05) that was significantly correlated with Pimax at rest (r: 0.81; P<0.001). The latter was also significantly correlated to pVO(2) (r: 0.84; P<0.001) and inversely correlated to ferritin levels (r: -0.6; P<0.02). Exercise capacity is markedly reduced in TM patients and this reduction is highly associated with the limited functional status of peripheral muscles.

High-resolution, high-sensitivity NMR of nanolitre anisotropic samples by coil spinning

Nuclear magnetic resonance (NMR) can probe the local structure and dynamic properties of liquids and solids, making it one of the most powerful and versatile analytical methods available today. However, its intrinsically low sensitivity precludes NMR analysis of very small samples-as frequently used when studying isotopically labelled biological molecules or advanced materials, or as preferred when conducting high-throughput screening of biological samples or 'lab-on-a-chip' studies. The sensitivity of NMR has been improved by using static micro-coils, alternative detection schemes and pre-polarization approaches. But these strategies cannot be easily used in NMR experiments involving the fast sample spinning essential for obtaining well-resolved spectra from non-liquid samples. Here we demonstrate that inductive coupling allows wireless transmission of radio-frequency pulses and the reception of NMR signals under fast spinning of both detector coil and sample. This enables NMR measurements characterized by an optimal filling factor, very high radio-frequency field amplitudes and enhanced sensitivity that increases with decreasing sample volume. Signals obtained for nanolitre-sized samples of organic powders and biological tissue increase by almost one order of magnitude (or, equivalently, are acquired two orders of magnitude faster), compared to standard NMR measurements. Our approach also offers optimal sensitivity when studying samples that need to be confined inside multiple safety barriers, such as radioactive materials. In principle, the co-rotation of a micrometre-sized detector coil with the sample and the use of inductive coupling (techniques that are at the heart of our method) should enable highly sensitive NMR measurements on any mass-limited sample that requires fast mechanical rotation to obtain well-resolved spectra. The method is easy to implement on a commercial NMR set-up and exhibits improved performance with miniaturization, and we accordingly expect that it will facilitate the development of novel solid-state NMR methodologies and find wide use in high-throughput chemical and biomedical analysis.

Multipole shimming of permanent magnets using harmonic corrector rings

Shimming systems are required to provide sufficient field homogeneity for high resolution nuclear magnetic resonance (NMR). In certain specialized applications, such as rotating-field NMR and mobile ex situ NMR, permanent magnet-based shimming systems can provide considerable advantages. We present a simple two-dimensional shimming method based on harmonic corrector rings which can provide arbitrary multipole order shimming corrections. Results demonstrate, for example, that quadrupolar order shimming improves the linewidth by up to an order of magnitude. An additional order of magnitude reduction is in principle achievable by utilizing this shimming method for z-gradient correction and higher order xy gradients.

Theory of MRI in the presence of zero to low magnetic fields and tensor imaging field gradients

Today, all commonly practiced magnetic resonance imaging (MRI) reconstruction methods assume that the magnetic field created by the gradient coils is everywhere truncated by a dominant static uniform magnetic field. However, with the advent of SQUID detected MRI at microtesla fields, the opposite limit attracts attention, i.e., image formation in the unperturbed tensor field of the gradient coils. Here, we show by numerical simulations that, in principle, it is possible to reconstruct the image of an object in the absence of a uniform static field, working with the same gradient field setup as used in conventional MRI. Our calculations show that this approach could increase the image resolution limit attainable at low fields with a minimal incorporation of additional hardware and pulse sequences.

Early recovery of oxygen kinetics after submaximal exercise test predicts functional capacity in patients with chronic heart failure

BACKGROUND

Oxygen (O2) uptake at peak exercise (VO2 peak) is an objective measurement of functional capacity in patients with chronic heart failure (CHF). The significance of recovery O2 kinetics parameters in predicting exercise capacity, and the parameters of submaximal exercise testing have not been thoroughly examined.

METHODS AND RESULTS

Thirty-six patients (mean age = 48+/-14 years) with CHF and New York Heart Association functional class I, II, or III, and eight healthy volunteers (mean age = 39+/-13 years) were studied with maximal and submaximal cardiopulmonary exercise testing (CPET). The first degree slope of O2 uptake decay during early recovery from maximal (VO2/t-slope), and submaximal exercise (VO2/t-slope)(sub), were calculated, along with VO2 half-time (T(1/2)VO2). Patients with CHF had a longer recovery of O2 uptake after exercise than healthy volunteers, expressed by a lower VO2/t-slope (0.616+/-0.317 vs. 0.956+/-0.347 l min(-1) min(-1), P=0.029) and greater T(1/2)VO2 (1.28+/-0.30 vs. 1.05+/-0.15 min, P = 0.005). VO2/t-slope correlated with the VO2 peak (r = 0.84, P<0.001), anaerobic threshold (r = 0.79, P<0.001), and T(1/2)VO2, a previously established estimate of recovery O2 kinetics (r = -0.59, P<0.001). (VO2/t-slope)(sub) was highly correlated with VO2/t-slope after maximal exercise (r=0.87, P<0.001), with the VO2 peak (r=0.87, P<0.001) and with T(1/2)VO2 after maximal exercise (r=-0.62, P<0.001). VO2/t-slope after maximal and submaximal exercise was reduced in patients with severe exercise intolerance (F=9.3, P<0.001 and F=12.8, P<0.001, respectively).

CONCLUSIONS

Early recovery O2 kinetics parameters after maximal and submaximal exercise correlate closely with established indices of exercise capacity in patients with CHF and in healthy volunteers. These findings support the use of early recovery O2 kinetics after submaximal exercise testing as an index of functional capacity in patients with CHF.

Approach to high-resolution ex situ NMR spectroscopy

Nuclear magnetic resonance (NMR) experiments are typically performed with samples immersed in a magnet shimmed to high homogeneity. However, there are many circumstances in which it is impractical or undesirable to insert objects or subjects into the bore of a high-field magnet. Here we present a methodology based on an adaptation of nutation echoes that provides resolved spectra in the presence of matched inhomogeneous static and radiofrequency fields, thereby opening the way to high-resolution ex situ NMR. The observation of chemical shifts is regained through the use of multiple-pulse sequences of correlated, composite z-rotation pulses, producing resolved NMR spectra of liquid samples.

Spectral editing in solid-state NMR using scalar multiple quantum filters

In this paper we describe the use of heteronuclear scalar couplings in solid-state NMR in order to generate multiple-quantum filtering (MQF) pulse sequences. These sequences can be used to edit CP/MAS spectra according to carbon multiplicity. Analytic expressions for the intensity of the MQF signals are obtained using the standard product operator formalism. Experiments that demonstrate the technique are shown in powder samples of camphor and a tripeptide.

Improved resolution in proton NMR spectroscopy of powdered solids

We present a new solid-state nuclear magnetic resonance experiment that yields, under CRAMPS decoupling conditions, a significant reduction in proton line widths for powdered organic solids. This experiment which relies on a constant-time acquisition of the proton transverse magnetization, removes the contribution of nonrefocusable broadening from the proton line widths. Although this new technique suffers from relatively low sensitivity, we demonstrate in this paper its feasibility on two model samples, L-alanine and the dipeptide Ala-Asp. In both cases a factor of between 2 and 3 in line width reduction is obtained for most of the proton resonances.

Flow-cytometric analysis of peripheral blood lymphocytes in patients with chronic idiopathic neutropenia of adults

Flow-cytometric analysis of peripheral blood lymphocytes was performed in 96 patients with chronic idiopathic neutropenia of adults (CINA) and in 36 age- and sex-matched healthy volunteers (controls) using a panel of monoclonal antibodies. Patients were classified arbitrarily into group A (68 patients with 2500-1500 neutrophils/microliter) and group B (28 patients with neutrophil counts below 1500/microliter). We found that CINA patients displayed low numbers of peripheral blood lymphocytes compared with the controls, which correlated with the numbers of circulating neutrophils. This decrease was due mainly to the reduction of T lymphocytes and, to lesser degree, to the decline of NK cells. Both CD4+ and CD8+ T cells decreased, so that the CD4+/CD8+ cell ratio remained within normal range. Moreover, decrease of T lymphocytes was due essentially to the diminution of CD45RO+ T-cell subsets (CD4+/CD45RO+ and CD8+/CD45RO+), while CD45RA+ T cells did not change. A highly significant positive correlation was found between the numbers of CD45RO+ T cells and the numbers of circulating neutrophils. All these alterations were more pronounced in the patients of group B than in those of group A. NK cells were found to be significantly reduced in the patients of group B, but not in those of group A. The numbers of both CD16+ and CD56+ cells correlated with the numbers of circulating neutrophils. Patients of group B had also low numbers of CD57+ cells, probably due to the reduction of T cells and NK cells. B cells did not change significantly. No significant changes were found also in the numbers of lymphocytes carrying activation-related cell surface markers. We concluded that lymphocyte reduction in CINA patients is due mainly to the diminution of CD45RO+ cells, and we postulated that the most probable explanation for this abnormality is an increased extravasation of these cells, which pass into the tissues following an accelerated adhesion to endothelial cells. This hypothesis and its relationship with the underlying neutropenia in CINA patients remain to be clarified.

Primary thyroid non-Hodgkin's lymphomas: clinicopathological observations on patients living in the island of Crete

Fifteen patients with primary thyroid non-Hodgkin's lymphomas (PT-NHLs) living in the island of Crete were studied. Patients' median age was 69 years, male/female ratio 1.5/1 and stage I/stage II ratio 2/1 (stages III and IV were excluded). According to the Working Formulation Classification, 2 cases were with low, 10 with intermediate and 3 with high grade of malignancy. Remission rate was 80%, median overall survival 61 months and median disease free survival 59 months. No significant difference in survival were found between stage I and II, as well as between males and females. Conclusing, PT-NHLs in the island of Crete are more frequent in males than in females, and are predominantly (67%) of the intermediate grade of malignancy.

Evidence for involvement of activated CD8+/HLA-DR+ cells in the pathogenesis of neutropenia in patients with B-cell chronic lymphocytic leukaemia

B-cell chronic lymphocytic leukaemia (B-CLL) is often associated with peripheral blood cytopenias resulting, in most cases, from bone marrow infiltration, hypersplenism, or circulating autoantibodies. The present study was undertaken to investigate the possible involvement of a cell-mediated suppression of granulopoiesis in these patients. We studied two groups of patients, 8 neutropenic and 26 non-neutropenic, defined by the arbitrarily taken cutoff count of 2000 neutrophils/microliters. We found that neutropenic patients had higher numbers of peripheral blood CD3+, CD8+ and CD57+ cells, and higher numbers of activated CD8+/HLA-DR+ cells than the non-neutropenic ones. A negative correlation between CD8+ cells and circulating neutrophils, and a suggested negative correlation between CD8+/HLA-DR+ cells and circulating neutrophils were noted in the patients studied. Furthermore, we investigated the capacity of immunomagnetically isolated CD8+ cells to inhibit in vitro colony formation by normal granulocyte/macrophage colony-forming units (CFU-GM) and we found that inhibition was more pronounced when CD8+ cells, added in the culture, were derived from neutropenic than from non-neutropenic patients. The degree of colony inhibition correlated with the number of circulating neutrophils and the numbers of CD8+ and CD8+/HLA-DR+ cells in the patients studied. Since tumour necrosis factor-alpha (TNF-alpha) has been reported to be involved in myelosuppression, we also investigated the capacity of isolated CD8+ cells to release this cytokine into the culture supernatant fluids, and we found that comparable amounts of TNF-alpha were produced after stimulation in both neutropenic and non-neutropenic patients. Elevated serum TNF-alpha concentrations were noted only in a number of neutropenic and non-neutropenic patients. All these data taken together provide strong evidence that a T-cell subpopulation of activated CD8+/HLA-DR+ cells may be involved in the pathogenesis of neutropenia, at least in a subset of B-CLL patients, suppressing myelopoiesis by a TNF-alpha-unrelated mechanism. Efforts to isolate this cell subpopulation by flow cytometry for further analysis and a better understanding of its effect on myelopoiesis in patients with B-CLL are in progress in our laboratory.