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Results for “The Right to Reproduce”

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PubMed2006

Development and reproducibility of the bone loading history questionnaire.

PURPOSE: To develop an historical bone loading questionnaire that assesses loads applied to the skeleton using bone loading units and to determine its reproducibility. Additional purposes were to correlate bone loading units with areal bone mineral density (aBMD) and to determine whether low levels of bone loading increase the odds for low aBMD in healthy premenopausal women. METHODS: Premenopausal women (N=80; age: 31+/-7.7 yr) completed the newly developed bone loading history questionnaire (BLHQ) twice within 4-6 wk to establish reproducibility. aBMD (g.cm) of the whole body, lumbar spine (L2-4), and right hip (proximal femur) were assessed with dual energy x-ray absorptiometry (DXA) in the women. RESULTS: The questionnaire demonstrated good test-retest reliability in premenopausal women using intraclass correlation coefficients (spine r=0.89, P<0.001; hip r=0.92, P<0.001). Total spine bone loading exposure (r=0.338; P=0.002) and hip bone loading exposure (r=0.317; P=0.004) were significantly and independently correlated with femoral neck aBMD, after adjusting for BMI. Logistic regression analyses revealed increased odds for low femoral neck aBMD among those in the lowest tertile for recent hip bone loading exposure after adjusting for older ages, oral contraceptive use, low calcium intake, and an overweight BMI (OR=3.62; CI=1.09-11.94; P=0.035). CONCLUSION: Historical bone loading activity can be reliably assessed and is moderately associated with femoral neck aBMD. This questionnaire could help to identify women with low femoral neck aBMD prior to menopause.

Absorptiometry, Photon↗

PubMed2001

The repeatability of echocardiographic determination of right ventricular output in the newborn.

BACKGROUND: Non-invasive measurement of left ventricular output has been shown to be a repeatable technique. Little is known about the repeatability using echocardiography in determining pulmonary arterial diameters or right ventricular output. AIMS: To find the most repeatable point at which to measure pulmonary arterial diameter, and to compare the repeatability of determining right ventricular output with left ventricular output. METHODS: We assessed the Intra-observer and inter-observer repeatability for measuring the diameter of the pulmonary trunk in 24 term and 26 preterm infants, respectively. Interobserver repeatability was assessed for the diameters of the pulmonary trunk and aorta, for stroke distance, and for left and right ventricular output. RESULTS: The coefficients of variation for intra-observer repeatability were 4%, 7.5% and 9% respectively for measurements of the pulmonary valve, the pulmonary trunk, and the right ventricular outflow tract. There were significant differences between observers for measurement of the pulmonary trunk (p<0.001) and right ventricular outflow tract (p=0.011) but not for the pulmonary valve measured in either its long (p=0.22) or short axis (p=0.22). Significant differences between observers were also found for the pulmonary stroke distance measured in the long axis (p=0.004) and aortic diameter at end-diastole (p<0.001). The other parameters did not differ significantly and were used to calculate right and left ventricular output, respectively. Mean left ventricular output was 241 mls/kg/min, with mean differences between observers of 0.6 mls/kg/min (95% confidence interval (CI): -39.2 to 40.3 mls/kg/min). Mean right ventricular output was 255 mls/kg/min, with mean differences of 0.3 mls/kg/min (95% CI: -24.1 to 23.4 mls/kg/min). CONCLUSION: Measuring the diameter of the pulmonary trunk at the base of the valvar hinge points was most repeatable. Repeatability of right ventricular output was similar to that of left, with absolute values similar to those published by other workers.

Analysis of Variance↗

PubMed1998

Optimization and mechanism of step-leap respiration exercise in treating of cor pulmonale.

The interaction between cardiovascular system and the respiratory system is complicated and may be used for the rehabilitation of the cor pulmonale disease. To study the effects of different breathing mode on the cardiac and pulmonary systems, a mathematical model is established based on the previous work. Using this model, computer simulation experiments are carried out for searching an optimal respiration mode in treating of cor pulmonale disease. Results indicate that the step-leap respiration mode could provide a better assistant to the rehabilitation of the cor pulmonale patients in the sense of increasing coronary flow, reducing pulmonary arterial pressure and reducing the working load for the right heart. This result is also proven by the clinical experiments. This work may suggest that a proper directed respiration exercise can be used in the treatment of cor pulmonale disease.

Algorithms↗

PubMed1998

ST-segment elevation in right precordial leads implies depressed right ventricular function after acute inferior myocardial infarction.

BACKGROUND: The prognosis of acute inferior myocardial infarction is worse when it is complicated by right ventricular infarction. ST elevation in the right precordial leads is one of the reliable methods for detecting acute right ventricular infarction. The purpose of the study was to examine the relation between ST elevation in the right precordial electrocardiographic leads during acute inferior infarction and the severity of right ventricular systolic dysfunction. METHODS: This study analyzed the relation between ST elevation > or = 0.1 mV in V4R and the severity of right ventricular systolic dysfunction in 43 consecutive patients (men/women: 35/8; average age 62+/-9 years) with acute inferior myocardial infarction with a rapid-response Swan-Ganz catheter to measure the right ventricular ejection fraction (RVEF). RESULTS: RVEF was significantly lower in patients with ST elevation (n = 18) than in those without (n = 25) (33%+/-6% vs 40%+/-9%, p = 0.010). If the infarct-related lesion was located in the proximal right coronary artery, RVEF tended to be lower than if the lesion was located in the distal right coronary artery or the left circumflex coronary artery (33%+/-10% vs 37%+/-9% vs 42%+/-9%, p = 0.101). Logistic regression analysis demonstrated that ST elevation in V4R was the only independent predictor of depressed RVEF (odds ratio = 5.31, 95% confidence interval = 1.28 to 22.1, p = 0.022). CONCLUSION: ST elevation in lead V4R during acute inferior myocardial infarction predicts right ventricular systolic dysfunction.

Adult↗

PubMed1994

Ultrasound assessment of normal hemidiaphragmatic movement: relation to inspiratory volume.

BACKGROUND: Traditionally the radiological assessment of diaphragmatic movement has relied on fluoroscopy. Ultrasound scanning has recently been shown to be a sensitive and reproducible method of assessing hemidiaphragmatic movement in normal subjects. A study was undertaken to examine how movement of the diaphragm measured by ultrasound scanning relates to inspired lung volumes measured by spirometric testing. METHODS: Ultrasound examinations were performed on 14 normal volunteers using a 3.5 MHz sector transducer (Acuson 128). A fixed skin position on each lateral chest wall between the anterior clavicular and midaxillary line was selected symmetrically to obtain a longitudinal plane of each hemidiaphragm including the maximal renal bipolar length, allowing identification of the adjacent posterior aspect of the diaphragm. Craniocaudal excursions of the posterior part of each hemidiaphragm on successive respiratory cycles were recorded on videotape and compared with spirometric measurements recorded simultaneously on a water bath spirometer. Measurements were made in the sitting and supine position and were repeated on a separate occasion (at least two weeks apart) in 10 subjects by the same operator to assess reproducibility. RESULTS: The relation between inspired volume and hemidiaphragmatic movement was found to be linear. The gradient of these observed linear relations (hemidiaphragmatic excursion (mm)/inspired volume (1)) was calculated and their distribution for each hemidiaphragm followed a normal distribution irrespective of position. The 95% confidence limits of the right to left ratio of these gradients in the supine position were 0.53 and 1.7. Change of posture from the supine to the sitting position reduced the gradient. The technique had acceptable reproducibility with coefficients of variation for the supine position of 7.5% and 11.7% for right and left hemidiaphragm respectively. CONCLUSION: Ultrasound scanning is a simple, non-invasive and reproducible means of assessing hemidiaphragmatic movement, yielding quantitative information which relates to inspired lung volumes.

Adult↗

PubMed1980

Flow cytometry of DNA content in human bone marrow: a critical reappraisal.

Because cytokinetic studies of the human bone marrow aspirate as a prognostic factor and as a monitor of drug perturbation are frequently inconsistent, we investigated reproducibility of DNA distribution measured by flow cytometry of DNA content in patients with morphologically normal bone marrow. In 15 patients, correlation was noted between DNA distributions simultaneously obtained on right and left iliac crest bone marrow aspirates (r = .588), although considerable variation in individuals was encountered. Much better reproducibility (r = .879) was achieved using bilateral core biopsy of bone marrow in these same patients. In 60 samples, comparison of DNA distribution between bone marrow aspirate and simultaneously obtained biopsy revealed higher relative proportions of S and G2 + M phase cells in biopsies (p less than 0.001), suggesting peripheral blood contamination of aspirate material. Brisk shaking of biopsy specimens in saline expelled a representative sample in the supernatant that could be subjected to simultaneous cytomorphological and cytokinetic analysis. To improve reproducibility of DNA content determinations in normal human bone marrow, bone marrow biopsy should be utilized.

Blood Cell Count↗

PubMed1997

A new method for reproducible coil positioning in transcranial magnetic stimulation mapping.

A new method is presented for mapping the motor cortex by transcranial magnetic stimulation in which the position of the stimulation coil on the scalp is measured using a 3D digitizer. The reproducibility of the method was tested by mapping 3 times the left abductor digiti minimi of 6 right-handed subjects and calculating the position of the centre of gravity (CoG), the area and volume of the individual maps. For individual maps, the coordinates of the CoG were found to be reproducible within +/-3 mm and the map areas and normalized volumes to within +/-20%, when the induced current flows anteriorly. Six more subjects were mapped to estimate interindividual variability of the position of the CoG. The method's ability to differentiate the cortical representation of two close muscles was successfully tested by mapping the flexor carpi radialis and the biceps brachii in another subject. Coordinates are given in a Cartesian frame of reference defined by the two tragi and the nasion. This feature will facilitate the comparison of results and their superposition on MR images.

Adult↗

PubMed1978

Handedness effects in kinesthetic spatial location judgements.

This experiment examines hemispheric assymetry in reproduction of spatial location in the kinesthetic modality. Using a dichotomous presentation technique, blindfolded, right-handed subjects moved both arms (arm positioning task) or the thumb (thumb positioning task) of each hand simultaneously to predetermined spatial locations and were subsequently asked to reproduce these locations. The results showed a marked left hand advantage only in the thumb positioning task suggesting that the right hemisphere was superior in performing this task. These data were discussed as they relate to other evidence pertaining to cerebral hemispheric specialization in motor activities.

Dominance, Cerebral↗

PubMed1987

Prospective comparison of right and left ventricular stimulation for induction of sustained ventricular tachycardia.

Thirty-eight patients who had sustained monomorphic ventricular tachycardia (VT) or sudden cardiac death underwent programmed ventricular stimulation. To assess the relative efficacy of right and left ventricular (RV and LV) stimulation, a tandem protocol with 1 to 4 extrastimuli and burst pacing was used. Each step of the protocol was performed in a rotating sequence at the RV apex, basal RV septum and LV apex. Sustained VT was induced from the RV apex in 26 patients, right ventricle (either site) in 27, and LV apex in 24, and spontaneous VT was reproduced from those sites in 11, 14 and 12 patients, respectively. In the 23 patients who had sustained VT induced from both ventricles, RV stimulation always required fewer or the same number of extrastimuli for induction. At every stage of the protocol, the cumulative yield of sustained VT was consistently greater from the right ventricle than from the left ventricle. After delivering 4 extrastimuli and burst pacing, LV stimulation only increased the yield of sustained VT by 1 patient, and spontaneous VT by 3 patients. Inducibility or noninducibility in the right ventricle generally predicted the same outcome in the left ventricle. Previously undocumented VT or ventricular fibrillation was induced from the right ventricle in 19 patients and from the left ventricle in 13. Thus, LV stimulation was less efficacious than RV stimulation. LV stimulation increased the yield over RV stimulation only minimally and did not reduce the number of extrastimuli required to induce sustained VT.

Cardiac Catheterization↗

PubMed2004

Functional MRI follow-up study of language processes in healthy subjects and during recovery in a case of aphasia.

BACKGROUND AND PURPOSE: The goal of this study was to develop a functional MRI (fMRI) paradigm robust and reproducible enough in healthy subjects to be adapted for a follow-up study aiming at evaluating the anatomical substratum of recovery in poststroke aphasia. METHODS: Ten right-handed subjects were studied longitudinally using fMRI (7 of them being scanned twice) and compared with a patient with conduction aphasia during the first year of stroke recovery. RESULTS: Controls exhibited reproducible activation patterns between subjects and between sessions during language tasks. In contrast, the patient exhibited dynamic changes in brain activation pattern, particularly in the phonological task, during the 2 fMRI sessions. At 1 month after stroke, language homotopic right areas were recruited, whereas large perilesional left involvement occurred later (12 months). CONCLUSIONS: We first demonstrate intersubject robustness and intrasubject reproducibility of our paradigm in 10 healthy subjects and thus its validity in a patient follow-up study over a stroke recovery time course. Indeed, results suggest a spatiotemporal poststroke brain reorganization involving both hemispheres during the recovery course, with an early implication of a new contralateral functional neural network and a later implication of an ipsilateral one.

Acoustic Stimulation↗

PubMed1983

Asymmetry in lateral directionality.

Effects of laterality and reading habits on directional preferences were investigated in two experiments. The subjects (N = 40 and 33 in Experiments I and II respectively) were right-and left-handed, male and female Israelis, whose native tongue was Hebrew. They identified and reproduced horizontal arrays of visual stimuli, which were presented either simultaneously (Experiment I), or sequentially (Experiment II). Directional preferences of the subjects' responses were recorded and analyzed. In Experiment I subjects of all groups showed similar, left-right directional preferences. In Experiment II right handers showed right-left preferences, whereas left handers showed inconsistent response patterns. Sex differences appeared among left handers only. The results were interpreted as showing the predominance of reading habit effects in Experiment I, and of laterality effects in Experiment II. It was therefore concluded that, depending on the experimental conditions, directional preferences may be a function of either reading habits, or laterality, or both.

Analysis of Variance↗

PubMed1998

Peripapillary nerve fiber layer thickness measurement reproducibility using scanning laser polarimetry.

PURPOSE: The authors assess the reproducibility of retinal nerve fiber layer (RNFL) thickness measurements using scanning laser polarimetry. METHODS: The right eyes of five healthy individuals were scanned by two trained operators (S.T.H., H.I.) using the Nerve Fiber Analyzer II (Laser Diagnostic Technologies, Inc., San Diego, CA, U.S.A.). Each participant was scanned six consecutive times per session for five sessions carried out over separate days within a two-week period. Intra- and interoperator measurement reproducibility was assessed. RESULTS: Intraoperator reproducibility was high. Mean coefficients of variation for total RNFL thickness measurements were 4.48 +/- 1.76% and 4.92 +/- 2.32% for operators 1 and 2, respectively. Interoperator reproducibility was high (p = 0.20-0.93) if a single ellipse was applied to the images of both examiners. However, measurement reproducibility worsened if each operator created his own measurement ellipse (p < or = 0.05 for 3 out of 5 participants). CONCLUSION: Interoperator error in image analysis can be minimized by using a single ellipse for the baseline and all subsequent scans even if subsequent scans are acquired by different operators.

Adult↗

PubMed2006

Evaluation of right ventricular Tei index (index of myocardial performance) in healthy dogs and dogs with tricuspid regurgitation.

Right ventricular (RV) Tei index (index of myocardial performance) has been demonstrated to be clinically useful in estimating RV function in various human cardiac diseases. The purposes of this study were to validate the correlation between RV Tei index and RV function obtained by cardiac catheterization in healthy dogs, and to evaluate the RV Tei index in dogs with tricuspid regurgitation (TR). In healthy dogs, the RV Tei index significantly correlated with the RV peak +dP/dt (r=-0.80, p<0.0001) and -dP/dt (r=0.69, p=0.0001). In normal dogs, the RV Tei index was not significantly correlated with heart rate, body weight, and age. The RV Tei index significantly increased in dogs with moderate to severe TR (0.39 +/- 0.35, p=0.0015), filariasis (0.46 +/- 0.16, p=0.0131), and trivial to mild TR and severe mitral regurgitation (MR; 0.61 +/- 0.14, p=0.0017) when compared with the normal dogs (0.17 +/- 0.10). In addition, the RV Tei index in dogs with TR significantly increased in association with pulmonary hypertension [PH(-), 0.19 +/- 0.09; PH(+), 0.65 +/- 0.14; respectively p<0.0001]. Our study has demonstrated that RV Tei index is a feasible approach to estimate RV function in dogs and is not influenced by heart rate, body weight, and aging. Further investigations are required to clarify the clinical significance of RV Tei index in dogs with right-sided cardiac diseases.

Aging↗

PubMed1998

How reproducible is bilateral forearm plethysmography?

AIMS: In studies using strain-gauge forearm plethysmography to measure changes in forearm blood flow (FBF) during intra-arterial infusions of vasoactive substances, measurements are often made in both arms simultaneously and the change in ratio of the infused and control arms used to express responses. However, the reproducibility of bilateral plethysmography in this setting has not been addressed in published studies. The unilateral technique remains in use, and forearm vascular resistance (FVR), an alternative method of expressing responses, is used by some investigators. We have assessed: (a) the intra-subject variability of bilateral FBF measurements (FBF ratios) at rest, after unilateral forearm exercise, and during intra-arterial infusions of vasoconstrictor substances; (b) whether bilateral plethysmography is more reproducible than unilateral plethysmography; and (c) the reproducibility of FVR (unilateral and bilateral). METHODS: Study 1 Nine healthy subjects attended 3 study days, 1 week apart. FBF was measured at rest and after 2 min of standardized unilateral forearm exercise; between-day intra-subject variability was expressed as coefficients of variation (CV) calculated using two-way analysis of variance (ANOVA). Study 2 Five healthy subjects attended 2 study days when FBF was measured during incremental infusions of noradrenaline (15, 30, 150, 300 pmol min[-1]) and angiotensin II (1, 5, 10, 50 pmol min[-1]); for each individual subject at each dose intra-subject variability was assessed using the difference between responses (percentage change from baseline) on days 1 and 2. RESULTS: Study 1 At rest, intra-subject variability (CV) of baseline FBF ratios was 19% compared with 31% (left) and 39% (right) for unilateral FBF measurements. After ipsilateral exercise, unilateral FBF measurements were more reproducible (32 vs 17%) than FBF ratios; by 20 min after exercise, the previous pattern had been re-established (19 vs 27%). Intra-subject variability (CV) of baseline FVR ratio and post-exercise FVR was 14%. Study 2 Inter-quartile ranges of the differences between responses on days 1 and 2 (FBF ratios vs FBF) were: angiotensin II 14 vs 18%; noradrenaline 16 vs 27%. CONCLUSIONS: FBF ratios are more reproducible than unilateral FBF measurements at rest (CV 19% vs 39%) and for measuring responses to intra-arterial infusions of vasoconstrictor substances. FVR may have a small reproducibility advantage. Non-experimental stimuli can cause significant and misleading changes in measured responses if unilateral measurements are used; it is therefore recommended that responses to intra-arterial infusions should be measured using bilateral forearm plethysmography with the results expressed as FBF ratios.

Angiotensin II↗

PubMed1987

Right ventricular endomyocardial biopsy: clinicopathologic correlates in 64 consecutive patients.

Endomyocardial biopsy is a safe, reliable, and reproducible technique to confirm or establish the diagnosis of the pathology that affects cardiac function in conditions previously classified as cardiomyopathies of unknown cause. The first 64 consecutive patients to undergo endomyocardial biopsy were reviewed to determine its utility in various clinical settings. Furthermore a review of literature relating to endomyocardial biopsy is presented. On the basis of these findings, we conclude that endomyocardial biopsy is indicated in the clinical setting of dilated cardiomyopathy, for evaluating underlying myocarditis. In patients with dysrhythmias or clinical myocarditis, endomyocardial biopsy may disclose myocarditis or changes consistent with congestive cardiomyopathy. In patients with systemic disease endomyocardial biopsy is instructive to prove or to exclude myocardial involvement. In patients with angina-like chest pain but with normal coronary angiograms or exercise tests, endomyocardial biopsy may prove underlying heart disease.

Biopsy↗

PubMed1977

Plain film identification of failure of interior vena caval-right atrial continuity.

The identification of absence of continuity of the inferior vena cava (IVC) with the right atrium assumes major importance at the time of right heart catheterization. The appearance of the IVC in the lateral chest radiogram is diagnostically different from the normal when discontinuity is present and 2 radiographic patterns have been recognized: 1) total absence of the IVC shadow; 2) straightened and posteriorly directed IVC shadow contrasting sharply with the anteriorly directed normally continuous IVC. This latter sign is considered reproducibly accurate in the identification of the IVC which fails to have continuity with the right atrium.

Adult↗

PubMed1998

Positioning device for optimal active kinematic real-time magnetic resonance imaging of the knee joint: a technical note.

OBJECTIVE: A prototype of a positioning device created especially for the diagnostic imaging of the patellofemoral joint was developed in order to achieve reproducible examination conditions. DESIGN: For this purpose a clinical trial on healthy test persons was carried out under real examination conditions. BACKGROUND: A special real-time MRI technique (Local-Look-technique) makes the analysis of active functional motion images possible. A prerequisite for this technique is accurate reproducible positioning of the knee joint in the MRI unit. METHODS: This positioning device was evaluated during a total of 50 examinations of the knee joints of five healthy test persons. The right patellofemoral joint of each test person was examined twice at different time points in order to check the reproducibility of all examination conditions. Comparing two examination series from the same individual, reproducibility of MRI slices was guaranteed by using identical anatomical landmarks. Image quality and test-retest reliability were analyzed on the computer screen. RESULTS: Optimal desired fixation of the leg in the MRI tube using the device was accomplished in all cases. The extent of motion of the knee joints ranged from 38 degrees (n = 2) to 40 degrees (n = 3) of flexion to full extension, which was satisfactory for the evaluation of the patellofemoral joint. Free movement of the patella and the lower leg was observed. The active functional MRI examination using this device was satisfactory and reproducible as assessed by test-retest reliability. CONCLUSIONS: The positioning device is a useful development in achieving active functional real-time MRI evaluation of the knee and patellofemoral joint. Using this diagnostic tool, reproducible quantitative examinations can now be easily performed. The reproducibility and high reliability as well as its simplicity of operation render this diagnostic tool suitable for use in orthopedics and traumatology.

Journal Article↗

PubMed1991

[Quantitative analysis of systolic function of the right ventricule by Doppler echocardiography].

The recording of the velocity of tricuspid valve regurgitation by continuous wave Doppler enables the calculation of the instantaneous systolic pressure gradient between the right ventricle and right atrium. As right atrial pressure is relatively constant, the rate of acceleration of the regurgitant jet reflects the quality of the rise in pressure in the right ventricle in early diastole, and therefore right ventricular contractility. The authors studied 3 Doppler parameters of the rate of velocity increase of the tricuspid regurgitation; the maximum rate of acceleration (dV/dt max), the maximum derivative of the pressure (dP/dt max) and the mean rate of increase in pressure (T). The interobserver variability of these indices is low (r greater than 0.96); reproducibility is good in patients with sinus rhythm but mediocre in atrial fibrillation. The comparison of the Doppler indices with the right ventricular isotopic fraction in 26 patients with tricuspid regurgitation showed a good correlation (dV/dt max, r = 0.79, p less than 0.0001; dP/dt max, r = 0.69, p less than 0.0001; T, r = 0.60, p = 0.0012). These results show that right ventricular systolic function can be evaluated by continuous wave cardiac Doppler by recording the spectral envelope of tricuspid regurgitation.

Aged↗