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PubMed2006

Non-invasive monitoring of renal oxygenation using BOLD-MRI: a reproducibility study.

Blood oxygenation level-dependent (BOLD) MRI was shown to allow non-invasive observation of renal oxygenation in humans. However, clinical applications of this type of functional MRI of the kidney are still limited, most likely because of difficulties in obtaining reproducible and reliable information. The aim of this study was to evaluate the reproducibility and robustness of a BOLD method applied to the kidneys and to identify systematic physiological changes potentially influencing the renal oxygenation of healthy volunteers. To measure the BOLD effect, a modified multi-echo data image combination (MEDIC) sequence was used to acquire 12 T2*-weighted images within a single breath-hold. Three identical measurements were performed on three axial and three coronal slices of right and left kidneys in 18 volunteers. The mean R2* (1/T2*) values determined in medulla and cortex showed no significant differences over three repetitions and low intra-subject coefficients of variation (CV) (3 and 4% in medulla and cortex, respectively). The average R2* values were higher in the medulla (16.15 +/- 0.11) than in the cortex (11.69 +/- 0.18) (P < 0.001). Only a minor influence of slice orientation was observed. Mean R2* values were slightly higher (3%) in the left than in the right kidney (P < 0.001). Differences between volunteers were identified (P < 0.001). Part of these differences was attributable to age-dependent R2* values, since these values increased with age when medulla (P < 0.001, r = 0.67) or cortex (P < 0.020, r = 0.42) were considered. Thus, BOLD measurements in the kidney are highly reproducible and robust. The results allow one to identify the known cortico-medullary gradient of oxygenation evidenced by the gradient of R2* values and suggest that medulla is more hypoxic in older than younger individuals. BOLD-MRI is therefore a useful tool to study sequentially and non-invasively regional oxygenation of human kidneys.

Adult↗

PubMed2006

In vivo 31P MR spectral patterns and reproducibility in cancer patients studied in a multi-institutional trial.

The standardization and reproducibility of techniques required to acquire anatomically localized 31P MR spectra non-invasively while studying tumors in cancer patients in a multi-institutional group at 1.5 T are reported. This initial group of patients was studied from 1995 to 2000 to test the feasibility of acquiring in vivo localized 31P MRS in clinical MR spectrometers. The cancers tested were non-Hodgkin's lymphomas, sarcomas of soft tissue and bone, breast carcinomas and head and neck carcinomas. The best accrual and spectral quality were achieved with the non-Hodgkin's lymphomas. The initial analysis of the spectral values of the sum of phosphoethanolamine plus phosphocholine normalized by the content of nucleotide triphosphates in a homogeneous sample of 32 NHL patients studied by in vivo (31)P MRS showed good reproducibility among different institutions. No statistical differences were found between the institution with the largest number of cases accrued and the rest of the multi-institutional NHL data (2.28 +/- 0.64, mean +/- standard error; n = 17, vs 2.08 +/- 0.14, n = 15). The preliminary data reported demonstrate that the institutions involved in this trial are obtaining reproducible 31P MR spectroscopic data non-invasively from human tumors. This is a fundamental prerequisite for the international cooperative group to be able to demonstrate the clinical value of the normalized determination of phosphoethanolamine plus phosphocholine by 31P MRS as predictor for treatment response in cancer patients.

Biomarkers, Tumor↗

PubMed2002

Reproducibility of quantitative dynamic MRI of normal human tissues.

The aim of the study was to establish the normal range and to evaluate the reproducibility of dynamic contrast enhanced MRI (DCE-MRI) parameter estimates in normal human pelvic tissues. Nineteen patients with prostate cancer, undergoing androgen deprivation treatment, had paired DCE-MRI examinations of the pelvis using spoiled gradient-echo sequences. Quantitative enhancement parameters were calculated for each examination: transfer constant (K(trans)), leakage space (v(e)) and maximum contrast medium accumulation (MCMA) of pelvic muscles, bone marrow and fat. Descriptive and reproducibility statistics were calculated: within-patient standard deviation (wSD), repeatability and within-patient coefficient of variation (wCV). The femoral head and ischiorectal fat showed large numbers of non-enhancing pixels (81 and 88%, respectively). The ischial bone marrow had the highest values of kinetic parameter estimates (K(trans) 0.554 min(-1), v(e) 18.5% and MCMA 0.164 mmol/kg). Muscle parameters values were lower (K(trans) 0.126-0.137 min(-1), v(e) 10.6-11.5% and MCMA 0.077-0.086 mmol/kg). The mean difference between paired examinations was not significantly different from zero for any parameter. v(e) and MCMA had the lowest wCV (between 19 and 29%). For individuals, a log(10) K(trans) change of approximately 0.90 in muscles and 0.52 in the ischium would be statistically significant. The corresponding absolute changes for v(e) are 6.7% in muscle and 13.6% in the ischium. For a group of 19 patients, small changes are statistically significant (muscle log(10) K(trans) 0.208 and v(e) 1.5% and ischium log(10) K(trans) 0.123 and v(e) 3.1%). Fat and the femoral head are unreliable tissues from which to obtain kinetic parameter estimates due to poor enhancement. v(e) and MCMA have smaller coefficient of variation than K(trans) in muscles and ischium. Reproducibility studies of normal and pathological tissues should be incorporated into clinical research protocols that measure treatment effects by DCE-MRI techniques.

Adipose Tissue↗

PubMed2005

Short TE single-voxel 1H-MR spectroscopy of hippocampal structures in healthy adults at 1.5 Tesla--how reproducible are the results?

The purpose of our study was to evaluate inter- and intra-subject variability and scan-rescan reproducibility of single-voxel 1H-MR spectroscopy (1H-MRS) in hippocampal structures at 1.5 T field strength. Thirty healthy adults were studied bilaterally by optimized, standardized short echo time single-voxel 1H-MRS (PRESS, TE=30 ms, TR=3000 ms, oblique voxel orientation, voxel size 2 cm3). Spectral analysis and absolute metabolite quantitation of N-acetylaspartate+N-acetylaspartyl-glutamate (tNAA), choline (Cho), creatine (Cr), total glutamate plus glutamine (Glu+Gln) and myo-inositol (Ins) were carried out by LCModel. Inter- and intra-individual reproducibility of these metabolite values were investigated by calculation of mean, standard deviation, coefficient of variation (CV), and by analysis of variance for repeated measurements. The smallest CV in intersubject variability was obtained for tNAA, followed by Cr, Cho, Ins and Glu+Gln. The results of the analysis of variance for repeated measures in inter-subject variability showed a marginal effect of scan repetition for Cr (p=0.063) and Glu+Gln (p=0.082); the rescan of both metabolites showed slightly higher concentrations. No statistical significant effect of scan repetition was seen for tNAA (p=0.913), Cho (p=0.857), and Ins (p=0.826). Rescan led to the same results and gave proof of good reproducibility. Scan-rescan testing in one subject showed comparable results: tNAA (CV=4.8%), followed by Cr, Ins, Glu+Gln and Cho (all CV above 10%).

Adult↗

PubMed2004

The reproducible acquisition of comparative liquid chromatography/tandem mass spectrometry data from complex biological samples.

An in-depth study of the reproducibility of data acquired for comparative proteomics analysis using a prototype two-stage heated laminar flow chamber fitted to a commercial high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) instrument was undertaken. The study is based on 24 replicate samples from four independent membrane preparations derived from two matched breast cancer cell lines. Variation and reproducibility in the data were evaluated at several levels highlighting the relative efficiency and variability of the acquisition routines used. Specifically, variation in the number and relative intensities of chromatographic peaks eluted from the LC column, precursor ion selection and sequence identification were evaluated. On average, approximately 6500 chromatographic peaks were generated for each acquisition with a corresponding coefficient of variance (CV) of less than 20%. Precursor ion selection and sequence identification averaged 1380 and 780 events per acquisition sample, respectively, with corresponding CVs of less than 10% for each. The reproducibility in the precursor ion selection was typically better than 60% between similar replicates. Using protein and peptide internal standards, it was found that the CV in retention time across the gradient between two acquisition pairs was typically less than 5%, whereas the average intensity ratio was 1.0 (expected) with a CV approaching 20%. An evaluation of the intensity ratios calculated from endogenous peptide sequences, identified across the acquisition set, indicated a CV of approximately 30%. Similarly, the CV associated with the top 1000 peptides indicated a mean and median of 28.4 and 26.95%. For a given acquisition pair it was also found that approximately 11% of the chromatographic peaks eluting from the column were linked to a sequence or identified. For these experiments, less than 10% of the peak pairs had absolute ratios greater than 2.0 and of those only approximately 10% had sequences linked to them. For each matched acquisition set on average 406 proteins were identified with a CV of less than 10%. Of the proteins that were identified approximately 30% had at least one predicted trans-membrane domain, indicating a four-fold increase over a crude homogenate sample with only minor enrichment. During these experiments it was found that the interface did not significantly alter the relative charge state distribution of ions, nor did it introduce significant interference from background ions. The interface was capable of 24-hour acquisition cycles.

Amino Acid Sequence↗

PubMed2002

Reproducibility probability in clinical trials.

For marketing approval of a new drug product, the United States Food and Drug Administration (FDA) requires that substantial evidence of the effectiveness of the drug product be provided through the conduct of at least two adequate and well-controlled clinical trials. The purpose of conducting the second clinical trial is to study whether the clinical result from the first trial is reproducible in the second trial with the same study protocol. Under certain circumstance, the FDA Modernization Act of 1997 includes a provision to allow data from one adequate and well-controlled clinical trial investigation and confirmatory evidence to establish effectiveness for risk/benefit assessment of drug and biological candidates for approval. In this paper, we introduce the concept of reproducibility probability for a given clinical trial, which is useful in providing important information for regulatory agencies in deciding whether a single clinical trial is sufficient and for pharmaceutical companies in adjusting the sample size in a future clinical trial. Three approaches, the estimated power approach, the method of confidence bounds and the Bayesian approach, are studied in evaluating reproducibility probabilities under several study designs commonly used in clinical trials.

Adult↗

PubMed1990

Effect of sample size on reproducibility of behavioral teratological study results: a computer simulation experiment using data from the Collaborative Behavioral Teratology Study of the National Center for Toxicological Research.

A computer simulation experiment which attempted to examine the effect of sample size on reproducibility of the effect of treatment was performed on the basis of actual data obtained from the Collaborative Behavioral Teratology Study of the National Center for Toxicological Research. The degree of the treatment effect was assessed in terms of the strength of the association (eta square). The results indicate that sample size has a large effect on the reproducibility of results which are assessed with the magnitude of SD for eta squares obtained from replication experiments. Suitable sample sizes to obtain relatively consistent results across studies were discussed, pointing out that not enough attention has been paid to the effect of sample size in the issue of reproducibility of results in some behavioral teratology studies.

Computer Simulation↗

PubMed2003

Reproducibility of three-dimensional ultrasound diagnosis of congenital uterine anomalies.

OBJECTIVE: To examine the reproducibility of the diagnosis of congenital uterine anomalies and the repeatability of measurements of uterine cavity dimensions using three-dimensional (3D) ultrasound. METHODS: The reproducibility of diagnosis of congenital uterine anomalies was examined by re-slicing stored 3D ultrasound volumes. Each data set was evaluated by two independent observers. Assessment of uterine morphology was performed in a standardized plane, with the interstitial portions of the Fallopian tubes used as reference points. Additionally, in 35 cases of congenital uterine anomalies the width of the uterine cavity (W), fundal distortion (F) and the length of unaffected uterine cavity (C) were measured. Intraobserver and interobserver variabilities were evaluated by each observer performing all three measurements twice. RESULTS: Eighty-three 3D ultrasound volumes were examined. Both operators classified 27 uteri as normal, 33 as arcuate, 19 as subseptate and three as unicornuate. A single case of uterine anomaly was described as arcuate uterus by one operator and subseptate by another (kappa 0.97). The intraobserver variability for each of the three measurements (W, F and C) was satisfactory with limits of agreement ranging from +/-1.43 to +/-2.51 mm. The examination of the interobserver variability showed no significant differences between the two observers (F = 0.484, P > 0.05). CONCLUSION: 3D ultrasound is a reproducible method for the diagnosis of congenital uterine anomalies and for the measurement of uterine cavity dimensions.

Female↗

PubMed2005

Measuring engagement of the fetal head: validity and reproducibility of a new ultrasound technique.

OBJECTIVE: Fetal head engagement can be assessed by translabial ultrasound and has been shown to be predictive of delivery mode. We attempted to validate the technique by comparing ultrasound with abdominal and vaginal palpation. Reproducibility was tested in a blinded test-retest series. METHODS: In a prospective clinical study, 139 nulliparous women between 35 + 3 and 40 + 4 weeks' gestation were assessed by translabial ultrasound, abdominal palpation of the fetal head (n = 139) and vaginal examination (n = 112). Ultrasound was performed using two methods, with the symphysis pubis as reference. A test-retest series was performed in 90 women. RESULTS: Ultrasound of head engagement correlated strongly with abdominal palpation, full Bishop scores and vaginal assessment (all P < 0.001 for Kendall's tau-b). Intraclass correlation coefficients (n = 90) for the two methods were 0.75 and 0.92, signifying excellent interobserver agreement. Reproducibility was higher for the method using the central symphyseal axis as reference. CONCLUSION: Quantitation of head engagement by translabial ultrasound is highly reproducible and correlates strongly with clinical measures of head engagement. We are now undertaking a prospective study to assess the predictive value of this new parameter for intrapartum events.

Female↗

PubMed1995

Optimization and reproducibility of random amplified polymorphic DNA in human.

In this work, we have optimized random amplified polymorphic DNA (RAPD) for the use of human DNA in altering the concentration of the reaction components and the steps of the thermal profile in the polymerase chain reaction. By using two primers in every reaction and 2.5 U Taq DNA polymerase, we found that DNA concentrations between 50 and 500 ng gave reproducible banding patterns. The tested DNA was extracted in seven different ways giving the same amplification results in six of them. We have also observed that reactions consisting of 35 cycles gave sufficient product yields. A slow heating/ramping from the annealing to the extension temperature increased the number of amplified bands and enhanced reproducibility. We conclude that RAPD is a robust and, under the mentioned conditions, reproducible method that could prove very useful for scientists and physicians.

Base Sequence↗

PubMed1996

The effect of saline iontophoresis on skin integrity in human volunteers. I. Methodology and reproducibility.

This study, conducted in 36 human volunteers, was an evaluation of the effects of saline iontophoresis on skin temperature, irritation, and barrier function. The major objectives were to assess the effects of low-level ionic currents, to validate the proposed methodology of assessment, and to establish reproducibility in repeated saline iontophoresis applications. This was the first of a multistage study designed to assess the safety of 24-hr saline iontophoresis episodes at selected currents and current densities. Since an iontophoresis patch challenges the skin barrier both by occluding the skin surface and by passing ionic current through the skin, the experimental protocol was designed to permit measurement of the contribution of each of these processes to the overall response. In this first stage we investigated the effect of 10 min of current delivery, at 0.1 mA/cm2 on a 1-cm2 area patch and 0.2 mA/cm2 on a 6.5-cm2 area patch compared to unpowered control patches. Twelve subjects were tested under each condition on two separate occasions to examine reproducibility of the response variable measurements. A further 12 subjects were tested once under the 0.2 mA/cm2, 6.5-cm2 condition. Skin irritation was evaluated via repeated measurements of transepidermal water loss, capacitance, skin temperature, skin color, and a visual scoring system, before the iontophoresis episode and after patch removal. No damage to skin barrier function in terms of skin-water loss or skin-water content was detected. Slight, subclinical, short-lasting erythema was observed for both conditions. Assessment of correlation coefficients showed highly statistically significant indications of reproducibility for all five response variables measured. The experimental design, in combination with a repeated measures analysis, provided clear separation of the occlusion and ionic current components of the iontophoretic patch challenge. Further, the repeated measures analysis gave a highly sensitive assessment of skin irritation and resolution after patch removal. We conclude that the experimental methodology is appropriate for assessing possible changes in skin integrity resulting from saline iontophoresis under similar operating conditions for longer durations and for other skin challenges from which a subclinical response is expected.

Body Temperature↗

PubMed1999

Reproducible flow cytometric methodology for measuring multidrug resistance in leukaemic blasts.

In order to bring MDR analysis into a clinical setting, reproducible assays with clear cut off points to define MDR positivity must be used. Sensitivity can also be increased by combining the results of more than one assay. We have used a combination of flow cytometric assays to define MDR positive and negative blasts in 47 AML patients entered into MRC trials. Our primary test is a standardised and reproducible assay for anthracycline accumulation in which we use carboxylate microspheres to bind the fluorescent drug daunorubicin (dnr). Cells and beads are incubated concurrently with dnr. Cellular dnr accumulation is quantified as a cell:bead fluorescence ratio. Confirmatory assays for MDR comprise the cyclosporin modulation assay for rhodamine 123 uptake and also measurement of lung resistance protein and multidrug resistance associated protein (with LRP-56 and MRPr1 respectively). 27/47 (57%) samples had both low and accumulation and at least one positive confirmatory test (a modulated functional assay and/or protein overexpression) and were categorised as "confirmed MDR". 15/47 patients (32%) were MDR negative in all 4 assays. 5/47 (11%) patients had unconfirmed low dnr accumulation. None of the patients in this cohort had high dnr accumulation alongside overexpressed LRP or MRP or functional P-glycoprotein. We believe that this approach to MDR analysis enhances the value of the highly reproducible functional assays. The use of a primary and confirmatory tests is also likely to improve specificity.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1995

Reproducibility of recall of adolescent diet: Nurses' Health Study (United States).

Although diet and alcohol consumption at a younger age have been hypothesized to play an etiologic role in adult malignancy, few studies have addressed these relations and few data exist on the ability to measure recalled diet during adolescence. We undertook a study to determine whether the recall of diet during high school 22 to 47 years later was reproducible within a prospective cohort of women. In 1986, participants in the Nurses' Health Study (United States), aged 40 to 65 years, reported their diet during high school using a 24-item food frequency questionnaire (FFQ). On the 1988 questionnaire, the participants recorded their alcohol consumption between the ages of 18 and 22. In 1994, a random sample of 275 women were asked to record again their high school diet and alcohol consumption. The average of Spearman correlations between the two recalls of high school diet was r = 0.57 (range = 0.38 to 0.74). For alcohol intake, the correlation for the time period queried was 0.66. The correlation between the two recalls of high school diet was higher than the correlation between the first recall and current diet in 1986 (average r = 0.25). There was no effect of age on reproducibility of recall. These data suggest that recall of diet from the very distant past, during a distinct time period such as high school, is reasonably reproducible. Although further studies of validity are needed, such information may be sufficiently precise to assess the influence of remote diet in epidemiologic studies.

Adolescent↗

PubMed1989

Intraobserver reproducibility in assigning brain tumors to classes in the World Health Organization diagnostic scheme. The Childhood Brain Tumor Consortium.

We studied how reproducibly neuropathologists assign childhood brain tumors to World Health Organization (WHO) diagnostic categories using a subsample from the Childhood Brain Tumor Consortium (CBTC) data. Among the 713 cases, 539 (76%) received the same diagnosis on two different readings by the same team of two neuropathologists. Among the 297 tumors in the supratentorial compartment, 201 (68%) received the same diagnosis on both reviews, whereas among the 392 tumors in the infratentorial compartment, 320 (82%) received the same diagnosis. The eight tumor diagnoses that were the most reliable were craniopharyngioma, germinoma, teratoma, medulloblastoma, pilocytic astrocytoma, ependymoma, subependymal giant cell astrocytoma, and choroid plexus papilloma, Px, the conditional probability of agreement given that one of the reviews resulted in specific diagnosis 'X', ranged from 0.97 to 0.75 for these diagnoses. In contrast, Px for 16 other childhood brain tumor diagnostic categories ranged from 0.60 to 0.00. Pilocytic astrocytoma, ependymoma, medulloblastoma, and astrocytoma not otherwise specified (nos) had significantly lower Px values (p less than 0.05) when these tumors were located in the supratentorial compartment than when below the tentorium. Px was not significantly lower for any category when tumors were located in the infratentorial compartment. The array of substituted diagnoses that lowered reproducibility was greater when tumors were located supratentorially. To improve the definitions, eliminate overlapping diagnostic categories, and sharpen the fuzzy boundaries that contribute substantially to limited reproducibility, we suggest: (1) the categories of astrocytoma nos, fibrillary astrocytoma, and protoplasmic astrocytoma be collapsed into a single category of astrocytoma; (2) the diagnostic category of desmoplastic medulloblastoma be combined with medulloblastoma; and (3) the criteria for anaplasia should be further refined to include quantification of critical histologic features, e.g., agreed upon operational definitions for amount of cell density, number of mitoses and pleomorphism for anaplastic astrocytoma and anaplastic ependymoma.

Brain Neoplasms↗

PubMed1993

Reproducible increases in blood pressure during intermittent noise exposure: underlying haemodynamic mechanisms specific to passive coping.

The purpose of the present study was to investigate the reproducibility of the increases in blood pressure found in our recent study on exposure to intermittent noise, to confirm the haemodynamic mechanism raising blood pressure (via an increase in peripheral vascular resistance expected to be specific to passive coping), and to assess baroreceptor cardiac reflex sensitivity in connection with the blood pressure elevation. A group of 16 young normotensive men participated in the experiment and underwent a 10-min intermittent exposure to pink noise at 100 dB (sound pressure level). The subjects also underwent three other stresses: a 1-min cold pressor test, a 3-min isometric handgrip and 3-min of mental arithmetic. The results indicated that blood pressure was elevated reproducibly for most of the noise exposure periods and that peripheral vascular resistance increased simultaneously, as expected. Baroreflex sensitivity was not suppressed. The results, as a whole, were in agreement with our recent findings for exposure to a similar type of noise and thus the reproducibility was corroborated. The mechanism raising blood pressure was similar in the cold pressor test. Conversely, during the isometric handgrip and mental arithmetic, blood pressure elevations were attributable mainly to increases in cardiac output. The implications of the opposing haemodynamic mechanisms raising blood pressure among the four stressful tasks have been discussed in relation to active versus passive coping required for each task. Differences in the magnitude of suppression observed in baroreflex sensitivity among the tasks have also been discussed in the context of defence reactions.

Acoustic Stimulation↗

PubMed1993

Are H and stretch reflexes in hemiparesis reproducible and correlated with spasticity?

The measurement of spasticity has always presented a problem to clinicians and researchers alike. As yet, there is no literature addressing the reproducibility of the existing barrage of clinical evaluations of spasticity and reflex measurement. Also not clear is whether or not a systematic relationship might exist between these multiple indices of spasticity. After delineating the differences in spasticity scores and reflex functions between spastic and normal states, the aims of this study were to examine the reliability of these measurements in hemiparetic subjects, and the correlation between altered reflex functions and clinically measured spasticity. An aggregate of lower limb reflexes was compared between ten spastic hemiparetic and seven age-matched normal subjects. Lower limb reflexes examined were: (1) the ratio of maximal H reflex to M response (H/M ratio), (2) the inhibition of the H reflex during vibration (Hvib/Hctl ratio), and (3) soleus stretch reflexes (SR/M ratio). H and stretch reflex latencies were shorter (P < 0.05), and reflex amplitudes were significantly greater (H/M ratios, P < 0.05; SR/M areas, P < 0.005) in spastic subjects. While H/M ratios, Hvib/Hctl ratios, SR/M areas and SR onset angles were highly reproducible, only some physiological measurements showed consistent but non-significant relationships with clinical spasticity. The decreased reflex latencies and increased reflex responses in the hemiparetic subjects suggested that spasticity may be related to reduced reflex thresholds. The physiological measurements and clinically assessed tone were both valid and reproducible, indicating that they can be used to evaluate the long-term effects of therapeutic intervention.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Reproducible lactulose hydrogen breath test as a measure of mouth-to-cecum transit time.

Breath hydrogen monitoring after oral lactulose syrup is a conventional measure of mouth-to-cecum transit time (MCTT), but its reproducibility has been questioned. We compared the reproducibility of five measurements of MCTT after a conventional breakfast (380 kcal) taken with tea containing 20 g lactulose to five measurements of MCTT after 20 g lactulose in water in eight normal volunteers. Individual mean breakfast transit time was not significantly different from lactulose transit time in each of the seven subjects, but one had a breakfast transit time of 151 +/- 15 min and a lactulose transit time of 86 +/- 22 minutes (X +/- SD, P less than 0.001). The coefficient of variation of breakfast transit time (11.6 +/- 5.3%, range: 6.9-24.2%) was less than that of lactulose transit time (30.7 +/- 7.8%, range: 22.1-50.0%, P less than 0.001). In a second set of experiments, the liquid phase marker (99mTechnetium-diethylene triamine pentaacetic acid) emptied from the stomach more rapidly after the lactulose solution (T1/2 16.3 +/- 5.4) than after the breakfast (33.9 +/- 10.9 min, P less than 0.01) and MCTT was shorter after lactulose (77 +/- 32 vs 104 +/- 40 min, respectively, P less than 0.05). There was no correlation between MCTT of lactulose and breakfast and between half-time gastric emptying and MCTT of either lactulose or breakfast. We conclude that the ingestion of inert lactulose induces an abnormally rapid MCTT and that breakfast MCTT is a much more reproducible investigation and should be employed in studies requiring serial measurements.

Adult↗

PubMed1996

Reproducibility of a new method to determine cough-induced leak-point pressure in women with stress urinary incontinence.

The aim of the study was to test the reproducibility of a new method of determining cough-induced leak-point pressure (CILPP). A cough-induced increased in intra-abdominal pressure was recorded vaginally in 26 women with stress incontinence and urinary leakage was detected electronically. CILPP determinations and short-term pad tests were carried out on two different occasions. Reproducibility is expressed by a coefficient of repeatability as limits of agreement. These indicate that, for 95% of the cases, a repeat measurement of CILPP will be between 0.72 and 1.28 times the first measurement. The coefficient of variation was 11.2%. There was a moderate inverse correlation between pad-test data and CILPP. It was concluded that the new method allows for an accurate determination of CILPP, which represents a quantitative and dynamic assessment of urethral function. The reproducibility of the method appears to be better than that of pad tests and standard urodynamic parameters. The correlation with pad-test data gives support to the validity of the method.

Adult↗