Measurements In Subjects Research Articles

Limitations of Muscle Ultrasound Shear Wave Elastography for Clinical Routine-Positioning and Muscle Selection.

Shear wave elastography (SWE) is a clinical ultrasound imaging modality that enables non-invasive estimation of tissue elasticity. However, various methodological factors—such as vendor-specific implementations of SWE, mechanical anisotropy of tissue, varying anatomical position of muscle and changes in elasticity due to passive muscle stretch—can confound muscle SWE measurements and increase their variability. A measurement protocol with a low variability of reference measurements in healthy subjects is desirable to facilitate diagnostic conclusions on an individual-patient level. Here, we present data from 52 healthy volunteers in the areas of: (1) Characterizing different limb and truncal muscles in terms of inter-subject variability of SWE measurements. Superficial muscles with little pennation, such as biceps brachii, exhibit the lowest variability whereas paravertebral muscles show the highest. (2) Comparing two protocols with different limb positioning in a trade-off between examination convenience and SWE measurement variability. Repositioning to achieve low passive extension of each muscle results in the lowest SWE variability. (3) Providing SWE shear wave velocity (SWV) reference values for a specific ultrasound machine/transducer setup (Canon Aplio i800, 18 MHz probe) for a number of muscles and two positioning protocols. We argue that methodological issues limit the current clinical applicability of muscle SWE.

Measuring subcutaneous fat thickness using skinfold calipers vs. high-resolution B-scan ultrasonography in healthy volunteers: A pilot study

Background & AimsMeasuring the thickness of skinfolds using calipers is a frequently used method for determining body fat in clinical practice. It is inexpensive and time saving compared to other methods and can be learned quickly. The aim of this study is to compare skinfold measurements made using calipers against measurements obtained using high-resolution ultrasonography (USG).MethodsA monocentric cross-sectional observational pilot study with 69 normal-weight volunteer participants aged between 18 and 80 years (women: n = 36, men: n = 33). Subcutaneous fat thickness was measured at five different sites (chest, abdomen, thighs, triceps, and back) using calipers and via USG.The mean values from the calipers and the USG measurements were examined for statistical significance using the paired t-test, and the Bland–Altman plot was used to compare the two methods. We then performed an agreement analysis by calculating the percentage of the differences less than or equal to 1 mm between the measurements made using calipers and those obtained via USG.ResultsFrom the Bland–Altman analysis, the best matches among measurements for the female subjects were the skinfolds on the triceps (ULoA: 4.6 mm, mean: −0.1 mm, LLoA: −4.8 mm), the back (ULoA: 3.9 mm, mean: −0.2 mm, LLoA: −4.4 mm), and on the chest (ULoA: 5.9 mm, mean: 0.6 mm, LLoA: −4.6 mm). In contrast, for the male subjects, the best matches were the skinfolds on the triceps (ULoA: 3.3 mm, mean: −0.3 mm, LLoA −4.0 mm), the back (ULoA 3.5 mm, mean −0.3 mm, LLoA −4.0 mm), and the thigh (ULoA 2.2 mm, mean −0.5 mm, LLoA −3.2 mm).The best agreement for women was obtained with the measurements of the chest fold (47.2%), followed by the measurements of the back fold (38.9%). For men, it was the measurements of the thigh fold (63.6%), followed by the measurements of the triceps (51.5%) and back fold (51.5%).ConclusionThe agreement between skinfold measurements made using calipers and ultrasonography depends on the skinfold thickness and the localization of the measurement, with gender-based differences. Measuring the thickness of skinfolds using calipers is a frequently used method for determining body fat in clinical practice. It is inexpensive and time saving compared to other methods and can be learned quickly. The aim of this study is to compare skinfold measurements made using calipers against measurements obtained using high-resolution ultrasonography (USG). A monocentric cross-sectional observational pilot study with 69 normal-weight volunteer participants aged between 18 and 80 years (women: n = 36, men: n = 33). Subcutaneous fat thickness was measured at five different sites (chest, abdomen, thighs, triceps, and back) using calipers and via USG. The mean values from the calipers and the USG measurements were examined for statistical significance using the paired t-test, and the Bland–Altman plot was used to compare the two methods. We then performed an agreement analysis by calculating the percentage of the differences less than or equal to 1 mm between the measurements made using calipers and those obtained via USG. From the Bland–Altman analysis, the best matches among measurements for the female subjects were the skinfolds on the triceps (ULoA: 4.6 mm, mean: −0.1 mm, LLoA: −4.8 mm), the back (ULoA: 3.9 mm, mean: −0.2 mm, LLoA: −4.4 mm), and on the chest (ULoA: 5.9 mm, mean: 0.6 mm, LLoA: −4.6 mm). In contrast, for the male subjects, the best matches were the skinfolds on the triceps (ULoA: 3.3 mm, mean: −0.3 mm, LLoA −4.0 mm), the back (ULoA 3.5 mm, mean −0.3 mm, LLoA −4.0 mm), and the thigh (ULoA 2.2 mm, mean −0.5 mm, LLoA −3.2 mm). The best agreement for women was obtained with the measurements of the chest fold (47.2%), followed by the measurements of the back fold (38.9%). For men, it was the measurements of the thigh fold (63.6%), followed by the measurements of the triceps (51.5%) and back fold (51.5%). The agreement between skinfold measurements made using calipers and ultrasonography depends on the skinfold thickness and the localization of the measurement, with gender-based differences.

Optical and electrophysiological techniques for functional assessment of vision system neuronal networks

We studied the two major channels of the vision system, which differ not only in their spatial-frequency characteristics but also in the sizes of the cellular structures that support the corresponding neuronal networks. We used a combination of optical and electrophysiological techniques to measure the properties of these channels in normal test subjects and in patients with various types of cognitive impairment. For electrophysiological measurements, a digital filter was used to generate stimuli with spatial-frequency responses for selective activation of each channel. Optical coherence tomography (OCT) and electrophysiological measurements in test subjects with various types of cognitive impairment were used to determine the relationship between morphological and functional changes in the vision system channel, which is primarily formed by the small-cell neuronal network and supports processing of high spatial frequencies.

Reliability of Isokinetic Hip Flexor and Extensor Strength Measurements in Healthy Subjects and Athletes: A Systematic Review and Meta-Analysis.

Background: The objective of this systematic review and meta-analysis was to examine the reliability of isokinetic measurements of hip strength in flexion and extension in healthy subjects and athletes. Methods: The databases used were Web of Science, SCOPUS, Medline and PubMed. R was used for all statistical analyses. Results: Hip flexion shows moderate reliability in the supine position (ICC = 0.72; 95% CI: 0.46–0.99) and good reliability in the standing position (ICC = 0.79; 95% CI: 0.54–1.04). Hip extension shows excellent reliability in the supine position (ICC = 0.90; 95% CI: 0.85–0.96) and moderate reliability in the standing position (ICC = 0.72; 95% CI: 0.48–0.96). Flexion of 120°/s and 180°/s showed excellent reliability (ICC = 0.93; 95% CI: 0.85–1.00), (ICC = 0.96; 95% CI: 0.92–1.01). The 60°/s and 120°/s extension showed good reliability (ICC = 0.90; 95% CI: 0.82–0.98), (ICC = 0.87; 95% CI: 0.75–0.99). The 180°/s extension presented excellent reliability (ICC = 0.93; 95% CI: 0.82–1.03). Conclusions: The standing position shows good reliability for hip flexion and the supine position shows excellent reliability for hip extension, both movements have excellent reliability at velocities between 120°/s to 180°/s.

Serum osteoprotegerin levels, endothelial function and carotid intima-media thickness in type 2 diabetic patients

ObjectivesOsteoprotegerin (OPG), a well-known protein that inhibits osteoclast formation and activity, might also be a potential marker for identifying patients with high cardiovascular risk. This study aimed to compare OPG levels, FMD, and CIMT measurements in subjects with vs. without diabetes and investigate the association of serum osteoprotegerin level with the early atherosclerotic markers, endothelial function, and carotid intima-media thickness (CIMT) in patients with type 2 diabetes mellitus (DM2). MethodsForty-nine patients with DM2 (F/M: 26/23, 49.3 ± 10.0 years) and 45 healthy volunteers (F/M: 26/19, 48.3 ± 7.5 years) were included in this cross-sectional study. Serum OPG levels were measured by solid-phase enzyme-linked immunosorbent assay (ELISA). Fasting plasma glucose (FPG) and HbA1c levels were measured. CIMT was measured by B-mode ultrasound, and endothelial function was evaluated via flow-mediated dilation (FMD) of the brachial artery with Doppler ultrasonography. ResultsSerum OPG levels were significantly higher in patients with DM2 (617.0 ± 111.0 pg/mL) compared to controls (481.0 ± 96.0 pg/mL, p < 0.001). While CIMT in diabetic patients (0.65 + 0.13 mm) was higher than controls (0.54 ± 0.10 mm, p = 0.009), FMD measurement was lower in DM2 group (4.2% ± 3.1 mm vs. 7.6% ± 4.1 mm, p = 0.01). Univariate analysis showed that OPG was associated with the presence of diabetes (OR: 6.999, p = 0.001, R2: 15.1%) and hypertension (OR = 6.925, p = 0.001, R2: 13.2%). There was no relationship between OPG levels and CIMT or FMD. ConclusionOsteoprotegerin and CIMT levels were increased, and FMD measurements were decreased in patients with DM2. No association between CIMT, FMD, and OPG measurements was observed. The presence of DM and hypertension were associated with circulating OPG levels.

A Robust Multi-Channel EMG System for Lower Back and Abdominal Muscles Training

Abstract EMG is an established method to acquire the action potentials of contracted muscles. Although commercial EMG systems are available and it is one of the most researched biosignals, it has never become widely used in rehabilitation or fitness training monitoring. The reasons are technical challenges of wearable EMG systems regarding electrode placement, motion artefacts and the complex connectivity of multi-channel EMG measurements. We address this problem for the lower back and abdominal musculature, through a novel dry electrodes belt, multi-channel high density EMG circuitry and problem-specific signal processing. The subject can easily strap the dry electrodes belt around himself which provides 16 EMG channels. Interferences from the ECG and motion artefacts are reduced by a stationary wavelet decomposition. Afterwards, an inter-channel filter is applied to increase the robustness of the signals. Subject measurements during different kinds of typical abdominal and lower back training exercises were performed wearing the novel dry electrodes belt. The results show the possibility of robust EMG measurements from the lower back and abdominal muscles by utilizing the gathered redundancy, appropriately. The additional information obtained via the multi-channel EMG circuitry and spatial oversampling can be used to address current problems of EMG applications. It combines the advantages of robustness and the capability of using comfortable dry electrodes. Therefore, the proposed measurement method for acquiring spatial information about the muscle contractions from the lower trunk can be used for rehabilitation or fitness training monitoring.

Binding the Acoustic Features of an Auditory Source through Temporal Coherence.

Numerous studies have suggested that the perception of a target sound stream (or source) can only be segregated from a complex acoustic background mixture if the acoustic features underlying its perceptual attributes (e.g., pitch, location, and timbre) induce temporally modulated responses that are mutually correlated (or coherent), and that are uncorrelated (incoherent) from those of other sources in the mixture. This “temporal coherence” hypothesis asserts that attentive listening to one acoustic feature of a target enhances brain responses to that feature but would also concomitantly (1) induce mutually excitatory influences with other coherently responding neurons, thus enhancing (or binding) them all as they respond to the attended source; by contrast, (2) suppressive interactions are hypothesized to build up among neurons driven by temporally incoherent sound features, thus relatively reducing their activity. In this study, we report on EEG measurements in human subjects engaged in various sound segregation tasks that demonstrate rapid binding among the temporally coherent features of the attended source regardless of their identity (pure tone components, tone complexes, or noise), harmonic relationship, or frequency separation, thus confirming the key role temporal coherence plays in the analysis and organization of auditory scenes.

Influence of repeated contacts on the transfer of elemental metallic lead between compartments in an integrated conceptual model for dermal exposure assessment

ABSTRACT Transfer of contaminants to and from the skin surface has been postulated to occur through a number of different pathways and compartments including: object(s)-to-skin, skin-to-skin, skin-to-clothing, skin-to-gloves, air-to-skin, skin-to-lips, and skin-to-saliva. However, many identified transfer pathways have been only minimally examined to determine the potential for measurable transfer. The purpose of this study was to quantitatively evaluate repeated transfer between different compartments using elemental metallic lead (Pb) in the solid form using a series of systematic measurements in human subjects. The results demonstrated that some transfer pathways and compartments are significantly more important than others. Transfer of Pb could not be measured from skin to cotton clothing or skin to laminate countertop surfaces. However, transfer was consistently measured for skin-to-skin and between the skin and the surface of nitrile gloves, suggesting the potential for significant transfer to or from these compartments in real-world exposure scenarios, and the importance of these pathways. With repeated contacts, transfer increased non-linearly between 1 and 5 contacts, but appeared to approach a steady state distribution among the compartments within 10 contacts. Consistent with other studies, relative to 100% transfer for a single contact, the quantitative transfer efficiency decreased with repeated contacts to 29% after 5 contacts and 11–12% after 10 contacts; for skin-to-skin transfer measurements, transfer efficiency after either 5 or 10 contacts was approximately 50% of the single contact transfer. These data are likely to be useful for refining current approaches to modeling of repeated contacts for dermal exposure and risk assessment.

Reliability of the weight-bearing ankle dorsiflexion range of motion measurement using a smartphone goniometer application.

BackgroundWeight-bearing ankle dorsiflexion range of motion measurement (weight-bearing lunge test) is gaining in popularity because it mimics lower extremity function in daily physical activities. The purpose of the study is to assess the intra-rater and the inter-rater reliability of the weight-bearing ankle dorsiflexion range of motion measurement with a flexed knee using a smartphone application Spirit Level Plus installed on an Android smartphone.MethodsThirty-two young, healthy subjects participated in the study and were measured in four sessions by two examiners. One measurement was taken on each ankle in every session. Eight measurements were taken from each participant. A total of 256 were taken from all the participants. The measurements for the individual subject were repeated no sooner than 24 hours after the first session. In order to assess the reliability, intraclass correlation coefficients (ICC), standard error measurements (SEM) and minimal detectable change (MDC) at the 95% confidence interval were calculated.ResultsStatistical data analysis revealed moderate intra-rater reliability for the right ankle (ICC = 0.72, 95% CI [0.49–0.85]) and good intra-rater reliability for the left ankle (ICC = 0.82, 95% CI [0.66–0.91]). Inter-rater reliability is moderate for the right (ICC = 0.73, 95% CI [0.52–0.86]) and the left ankle (ICC = 0.65, 95% CI [0.39–0.81]).ConclusionThe observed method is moderately reliable and appropriate when the main objective is to assess ankle dorsiflexion mobility in weight-bearing when weight-bearing is not contraindicated. The concurrent validity of the Spirit Level Plus application is excellent.

Management of primary hypothyroidism in adults: An analysis of the results of a survey in 546 primary care physicians

ObjectiveTo document current practices in the management of adult patients with hypothyroidism in the setting of primary healthcare. MethodsWe designed a web-based survey to inquire information on real-life practices regarding management of hypothyroidism by primary care physicians in the region of Madrid (Spain). ResultsIn total, 546 out of 3897 (14%) physicians (aged 50.9±8.5 yr, 404 females) completed the survey. More than 90% of respondents requested serum thyrotropin measurement in subjects with symptoms of thyroid hypofunction, family history of thyroid disease and history of autoimmune disease. A thyroid ultrasound was requested to evaluate subclinical and overt hypothyroidism by 27.1% and 69.6% of respondents, respectively. Only 22.1% of respondents stated that they do not treat subclinical hypothyroidism with thyrotropin values less than 10mU/l. Most physicians use brand-name formulations of levothyroxine and advise patients on how to take the tablets. To start treatment, the gradual replacement rate was the option chosen by most of the respondents, even in young patients. The thyrotropin target preferred by most respondents was 0.5–5.0mU/l, especially in older patients. In patients with persistent symptoms, 61.4% search for the causes through complementary investigations. A longer professional practice time was not always accompanied by better adherence to guidelines and expert recommendations. ConclusionOur results reveal a proactive attitude in the diagnosis and of therapy by most of the respondents. However, we observed a tendency to perform unnecessary diagnostic tests and an excessive propensity to treat mild subclinical hypothyroidism.

Flexible Segmented Surface Coil Resonator for In Vivo EPR Measurements in Human Subjects

Flexible Segmented Surface Coil Resonator for In Vivo EPR Measurements in Human Subjects

Duration and temporal dispersion measurements in CIDP subjects from the Polyneuropathy And Treatment with Hizentra (PATH) study

Abstract:&#x0D; Introduction: Distal compound muscle action potential (dCMAP) duration and temporal dispersion (TD) are electrophysiological hallmarks of demyelination and important for the diagnosis of CIDP. While the impact of CIDP treatment on other nerve conduction parameters has been examined, the effects on dCMAP and TD remain unexplored. The aim of the study was to examine the impact of withdrawal of immunoglobulin treatment on dCMAP duration and TD, and also the influence of the measurement technique on dCMAP duration and TD.&#x0D; Methods: Nerve conduction studies were analyzed from the PATH (Polyneuropathy And Treatment with Hizentra) study which randomized patients with CIDP to two doses of IgPro 20 and placebo. Distal CMAP duration and TD were obtained by two methods of measurements (D1 and D2, TD1 and TD2) from the median and peroneal nerves. &#x0D; Results: The dCMAP and TD were obtained from 389 tracings. While the two methods of measurement showed differences in D1 and D2 with D2 longer than D1 in all the three groups, there was no difference between the TD1 and TD2. There was no difference at baseline in dCMAP duration or TD among the three groups. At the end of treatment, patients in the placebo arm had no worsening of dCMAP and TD compared to baseline or the treated groups.&#x0D; Conclusion: dCMAP duration and TD did not show a difference between treated and placebo groups, and may be less sensitive measures than other nerve conduction parameters when evaluating changes in treatment. The method of dCMAP duration measurement does not affect TD as long as a consistent method is followed.&#x0D;

Empirical Capacity Measurements of Electric Vehicles Subject to Battery Degradation From V2G Services

Accelerated battery degradation, resulting in a reduced capacity, is the main concern when discussing vehicle-to-grid (V2G) services. This paper gives a unique empirical insight into the long-term effects on batteries performing an energy demanding V2G service. To this end, an extensive method for measuring the battery capacity of series produced electric vehicles (EVs) via the DC charge port was developed. The reproducibility of the method is demonstrated with repeated tests on new and aged vehicles and the results are compared with the EVs internal estimates, read via the on-board diagnostics port. The method is also validated with a state-of-the-art battery degradation model. The capacity test method is used to evaluate the battery degradation of a fleet of commercially owned EVs which, as a part of the world's first commercial operation, have been used for V2G services for five years. The EVs have, together with ±10 kW V2G chargers, been delivering primary frequency regulation for 15 hours per day with a daily energy throughput of 50.6 kWh. The usable battery capacity, initially found to be 23 kWh, after two years is reduced on average to 20.7 kWh and after five years is reduced to 18.9 kWh.

Pituitary Volume in Patients with Primary Empty Sella and Clinical Relevance to Pituitary Hormone Secretion: A Retrospective Single Center Study.

Background According to neuroradiological findings, empty sella seems to be deprived of pituitary tissue in sella turcica. Changing size of the pituitary volume is closely related to the occurrence of primary empty sella. The aim of the study is to determine pituitary dysfunction in patients with partial or total primary empty sella and the significance of pituitary volume measurements in these patients.Methods This study was designed retrospectively. 67 patients (55 females, 12 males) diagnosed with primary empty sella syndrome between the years of 2015-2019 were included in the study. Patients were divided into two groups: partial (PES) and total (TES) empty sella by magnetic resonance imaging (MRI). Basal anterior pituitary and its hormones were assessed. We also included 26 healthy control subjects (19 females, 7 males) to compare the differences in pituitary volumes. Volumes were measured by using Osirix Dicom Viewer (Pixmeo SARL, Geneve, Swiss) in 3.0 Tesla scanner MRI.Results82.1% (n=55) of all patients were PES and the others were (n=12) TES. Hypopituitarism, known as one or more pituitary hormones deficiency, was found in 12 patients (17.9%). While 9 of them had total PES, the others had partial PES. Secondary adrenal insufficiency and gonadotropin deficiency were more prevalent in patients with TES. Mean volume measurements of patients with TES, PES and healthy subjects were 0.23±0.17, 0.35±0.15, 0.54±0.17 cm3, respectively. Except for IGF1 values (p=0.026), there was not any significant correlation found between the anterior pituitary hormones and volume measurements.ConclusionAlthough volume measurement has helped in the diagnosis of pituitary empty sella (partial or total), it does not seem to have any significant correlation with pituitary secretory function.

Associations of hair cortisol concentrations with paediatric appendicitis

The pathogenesis of paediatric appendicitis is still an enigma. In recent years, it has become more evident that our inherent immunological responses affect the trajectory of the disease course. Long-term stress has an impact on our immune system; however, it is practically and ethically challenging to prospectively track blood measurements of cortisol-levels in asymptomatic children should an acute appendicitis episode develop. The aim of this case–control study was therefore to evaluate the effect of increased stress measured as historical imprints in hair (hair cortisol concentrations [HCC]), on the risk of developing appendicitis and complicated appendicitis. 51 children (aged < 15 years) with appendicitis (34 with complicated appendicitis), were compared to 86 healthy controls. HCC reflecting the activity of the HPA-axis 0–3 and 4–6 months prior to sampling was evaluated and compared between groups as well as between the two measurements of each study subject. In the univariate analysis with both cases and controls, an increase in HCC between the measurement timepoints was associated with a substantial increase in risk of appendicitis (OR 7.52 [95% CI 2.49–22.67], p = 0.001). This increased risk remained in the multivariate analysis after adjustment for age, sex and season (aOR OR 10.76 [95%CI 2.50–46.28], p = 0.001). When comparing the cases of uncomplicated and complicated appendicitis through a multivariate analysis, adjusted for age and sex, the children with an increased HCC prior to appendicitis had a substantial and statistically significant increase in risk of complicated appendicitis (aOR 7.86 [95% CI 1.20–51.63], p = 0.03). Biological stress, measured as an increase in HCC, seems to be associated with an increased risk of paediatric appendicitis and a more complicated disease course.

Growth Assessment of Tree Species Growing in the Amhara Region in Ethiopia

ABSTRACT Ethiopian mixed forests have multipurpose benefits and services. However, there is a gap of information in the entire Ethiopian highlands on forest growth needed for implementation of sustainable forest management and provision of ecosystem services. Therefore, main aim of this study was to identify main factors deriving tree growth in forest and woodland in Amhara Regional State of Ethiopia and to provide an individual tree basal area increment (BAI) model based on increment cores. The data came from 170 sampling plots in study area and cover 51 tree species. For each tree species, diameter at breast height (DBH), height, increment core measurement, tree location, and distance from subject tree measurements were recorded. Because of large number of trees species, it is difficult to develop growth functions for each individual tree species. Thus, classification of species groups provided a framework to organize information that differs between vegetation types. Our classification resulted in three groups. For each tree species group, an individual tree BAI model was calibrated. The tree species group of BAI differs by DBH class. The response to BAI depends on competitive condition of a tree. This growth model can be used to predict tree growth for Ethiopian mixed-species forests.

The Effect of Ceiling Heating and Mechanical Ventilation on Thermal Comfort

In the case of public buildings with ceiling heating and mechanical ventilation, radiant temperature asymmetry caused by the warm ceiling and draught occur simultaneously. The currently available literature does not offer an exhaustive description of the comfort conditions resulting from such a thermal environment. This research focuses on complementing the available knowledge, using instrumental measurements, as well as subject measurements carried out on 20 individuals. Relying on these measurements, the purpose of the research is to support the understanding of the combined mechanisms of action of the two local discomfort parameters. The main result of this research is that, if the predicted percentage dissatified is less than 6%, the radiant temperature asymmetry is in an interval of 5–15 °C, and the draught rate is 15% or 25%, the actual mean vote and the predicted mean vote values differ significantly, and the actual mean vote is always lower, with a few exceptions. In addition, the research highlights the changes of the actual mean vote caused by raising the draught rate from 15% to 25%, in the presence of radiant temperature asymmetry caused by warm ceilings.

Comparison of novel DXA system, Shimazu SONIALVISION G4, with GE-Lunar PRODIGY.

SONIALVISION G4 (Shimadzu, Kyoto, Japan) is a fluoroscopic imaging system capable of dual-energy X-ray absorptiometry (DXA) using the additional application. However, bone mineral density (BMD) with this system is calibrated only by a phantom, and the necessity to confirm the reliability of BMD measurement in human subjects has been pointed out. This study aimed to evaluate the clinical reliability of BMD measurement using SONIALVISION G4 by comparing it with PRODIGY (GE Healthcare, Madison, WI, USA), a reference system in developing the DXA application. BMD measurements using these two DXA systems were performed on the same day at the lumbar spine and bilateral proximal femur of 130 subjects aged 22-86years. The agreement and correlation between the measurements were determined. Thirty out of the 130 subjects were scanned twice to determine the precision of the SONIALVISION G4 system. BMD was highly correlated between the two DXA systems both at the lumbar spine and proximal femur, with correlation coefficients ranging from 0.963 (left total hip) to 0.989 (left femoral neck). Differences in BMD measured by the two systems were less than 3.0%, but a small proportional bias was observed in the Bland-Altman analysis. Coefficients of variation in BMD measurement were 1.77% in the lumbar spine and 1.41-2.76% in the proximal femur. Although BMD values by SONIALVISION G4 were close to those by PRODIGY, follow-up studies should be performed using the same device because of the small difference between devices.

Serial measurements of fractional exhaled nitric oxide at home and at work: A useful tool for monitoring workers with platinum salt allergy after exposure reduction.

Serial measurements of fractional exhaled nitric oxide at home and at work: A useful tool for monitoring workers with platinum salt allergy after exposure reduction.

Effect of ECG-gating Retinal Photographs on Retinal Vessel Caliber Measurements in Subjects with and without Type 2 Diabetes

ABSTRACT Purpose/Aim of this study: Retinal vessel caliber is an independent risk marker of cardiovascular disease risk. However, variable mechanical delays in capturing retinal photographs and cardiac cycle-induced retinal vascular changes have been shown to reduce the accuracy of retinal vessel caliber measurements, but this has only ever been investigated in healthy subjects. This cross-sectional study is the first study to investigate this issue in type 2 diabetes. The aim of this study was to determine whether ECG-gating retinal photographs reduce the variability in retinal arteriolar and venular caliber measurements in controls and type 2 diabetes. Materials and Methods: Fifteen controls and 15 patients with type 2 diabetes were arbitrarily recruited from Westmead Hospital, Sydney, Australia. A mydriatic fundoscope connected to our novel ECG synchronization unit captured 10 ECG-gated (at the QRS) and 10 ungated digital retinal photographs of the left eye in a randomized fashion, blinded to study participants. Two independent reviewers used an in-house semi-automated software to grade single cross-sectional vessel diameters across photographs, between 900 and 1800 microns from the optic disc edge. The coefficient of variation compared caliber variability between retinal arterioles and venules. Results: Our ECG synchronization unit reported the smallest time delay (33.1 ± 48.4 ms) in image capture known in the literature. All 30 participants demonstrated a higher reduction in retinal arteriolar (ungated: 1.02, 95%CI 0.88–1.17% vs ECG-gated: 0.39, 95%CI 0.29–0.49%, p < .0001) than venular (ungated 0.62, 95%CI 0.53–0.73% vs ECG-gated: 0.26, 95%CI 0.19–0.35%, p < .0001) coefficient of variation by ECG-gating photographs. Intra-observer repeatability and inter-observer reproducibility analysis reported high interclass correlation coefficients ranging from 0.80 to 0.86 and 0.80 to 0.93 respectively. Conclusion: ECG-gating photographs at the QRS are recommended for retinal vessel caliber analysis in controls and patients with type 2 diabetes as they refine measurements.