Standardized Methods (standardized + methods)

Distribution by Scientific Domains


Selected Abstracts


Application of Histomorphometric Methods to the Study of Bone Repair,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2005
Louis C Gerstenfeld
Abstract ABSTRACT: Standardized methods for the histomorphometric assessment of bone are essential features of most studies of metabolic bone diseases and their treatments. These methodologies were developed to assess coupled remodeling, focusing primarily on osteoblasts and osteoclasts, the anabolic and catabolic rates of these cells, and structural features of mature bone. Research studies on bone healing and the development of new therapeutic approaches for the enhancement of bone repair also require a comprehensive understanding of the basic cellular and tissue level mechanisms that underlie these processes. However, the histological methods developed for metabolic bone disease studies are not completely suitable for studies of bone repair because they are based on assumptions that there is little variation in tissue composition within a sample of bone and not generally designed to quantify other types of tissues, such as cartilage, that contribute to bone healing. These techniques also do not provide tissue-based structural measurements that are relatable to the specific types of biomechanical and radiographic structural assessments that are used to determine rates of bone healing. These deficiencies in current histological approaches therefore point to the need to establish standardized criteria for the histomorphometric assessments that are specifically adapted for the study of bone repair in models of fracture healing and bone regeneration. In this Perspective, we outline what we believe to be the specific structural, tissue. and cellular aspects that need to be addressed to establish these standardized criteria for the histomorphometric assessment of bone repair. We present the specific technical considerations that need to be addressed to appropriately sample repair tissues to obtain statistically meaningful results and suggest specific procedures and definitions of nomenclatures for the application of this technology to bone repair. Finally, we present how aspects of histomorphometric measurements of bone repair can be related to biomechanical and radiographic imaging properties that functionally define rates of bone healing, and thus, how these tools can be used to provide corroborating data. [source]


Definition of restless legs syndrome, how to diagnose it, and how to differentiate it from RLS mimics

MOVEMENT DISORDERS, Issue S18 2007
Heike Benes MD
Abstract Restless legs syndrome (RLS) is a clinical diagnosis based primarily on self-reports of individuals. The International RLS Study Group has published diagnostic criteria that are essential for an operational diagnosis of RLS; further clinical features are considered by the group supportive for or associated with RLS. However, sensitivity and specificity are not perfect and "mimics" of RLS have been reported, i.e., other conditions like nocturnal cramps sometimes can appear to fulfill the essential diagnostic criteria indicating the need for more thorough understanding of the diagnostic criteria and better differential diagnoses. To contribute to the accuracy of diagnostic processes in RLS, we recapitulate the definition of RLS as an urge to move focused on the legs (and arms in some patients). This urge to move often but not always occurs together with dysesthesia, i.e. unpleasant abnormal sensations appearing without any apparent sensory stimulation. The urge to move and any accompanying dysesthesia must be engendered by rest, relieved by movement and worse in the evening or night. Succinctly, RLS can be summarized in medical terminology as a "movement-responsive quiescegenic nocturnal focal akathisia usually with dysesthesias." Empirical approaches to investigate the independence of the essential criteria "worsening at night" and "worsening at rest" are reported. Possible differential diagnoses of RLS are discussed under the perspective of the NIH diagnostic criteria of RLS. Standardized methods to assess a RLS diagnosis are presented which might improve differential diagnosis and in general the reliability and validity of RLS diagnosis. © 2007 Movement Disorder Society [source]


Protocol for clinical neurophysiologic examination of the pelvic floor

NEUROUROLOGY AND URODYNAMICS, Issue 6 2001
Simon Podnar
Abstract Clinical neurophysiologic examination of the pelvic floor is performed worldwide, but there is no consensus on the choice of tests, nor on technical details of individual methods. Standardized methods are, however, necessary to obtain their valid application in different laboratories for the purpose of collection of normative data, comparison of patient data and organization of multi-center studies. It is proposed that in patients with suspected "lower motor neuron" type lesions concentric needle electromyography (CNEMG) is the most informative test to detect pelvic floor denervation/reinnervation, and the external anal sphincter (EAS) muscle is the most appropriate muscle to be examined (either in isolation,when a selective lesion is suspected,or in addition to examination of other muscles). An algorithm consisting of standardized tests including a standardized approach to CNEMG examination of the EAS is presented. The proposed electrophysiologic assessment consists of a computer-assisted analysis of denervation and reinnervation features of the CNEMG signal, a qualitative assessment of reflex and voluntary activation of EAS motor units, and of electrical (or mechanical) elicitation of the bulbocavernosus reflex in those patients in whom manual anogenital stimulation failed to elicit a robust response in the EAS. The proposed protocol could serve as a basis for further studies on validity, sensitivity and specificity of electrophysiologic assessment in patients with different types of "lower motor neuron" involvement of pelvic floor muscles and sacral dysfunction. Neurourol. Urodynam. 20:669,682, 2001. © 2001 Wiley-Liss, Inc. [source]


Sampling and analysis of microcystins: Implications for the development of standardized methods

ENVIRONMENTAL TOXICOLOGY, Issue 2 2007
Angeline R. Tillmanns
Abstract Microcystins (MC), a group of cyanotoxins, have been found in lakes and rivers worldwide. One goal of MC research is to develop models which predict MC concentrations, but these efforts have been hampered by a lack of standardized methods necessary for comparing data across studies. Here, we investigate the effect of chemical analysis (HPLC-PDA and ELISA), sample collection (whole water, plankton tow and surface scum), and choice of normalizing parameter (volume, dry weight, and chlorophyll a) on reported MC concentrations. Samples were collected over three years from a temperate mesotrophic, shallow lake with episodic blooms of cyanobacteria. We found that microcystins were up to four times higher in lake samples when analyzed by ELISA relative to HPLC-PDA and that MC concentration measured by HPLC explained less than half of the variation in MC concentrations measured by ELISA. Also, samples collected by plankton tow gave consistently higher concentrations than whole water samples. An additional HPLC analysis of two chlorophyte cultures revealed the presence of compounds with a similar UV absorbance spectrum to MC-LR, suggesting that identifying MC based solely on UV absorbance is not valid. Our results document the discrepancy in MC concentrations that can arise by using different methods throughout all stages of sampling, analysis, and reporting of MC concentrations. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 132,143, 2007. [source]


Influence of Emergent and Submerged Macrophytes on the Structure of Planktonic Ciliate Communities in Shallow Freshwater Lakes (Eastern Poland)

INTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 3 2008
Tomasz Mieczan
Abstract Data from two shallow macrophyte-dominated lakes (Eastern Poland) sampled with standardized methods, were evaluated in order to examine the effects of various stands of macrophytes in predicting protozooplankton community structure. Differences in macrophyte structure led to two distinct groups of habitats having different patterns of ciliate distribution. The first group consists of two vegetated habitats of sparse stem density and of the open water zone, and the second of submerged macrophyte species, which were more dense and complex. The number of significant correlations was different in the studied habitats. In central zones of macrophyte habitats the number of ciliates had the strongest correlation with concentrations of total organic carbon and Ptot. On the other side in the border zone a significant correlation between the number of ciliates and the chlorophyll a concentration was found. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Detection, survival rates and dynamics of a cryptic plant, Asclepias meadii: applications of mark-recapture models to long-term monitoring studies

JOURNAL OF ECOLOGY, Issue 2 2009
Helen M. Alexander
Summary 1Analysis of population trajectories is central to assessing risk in populations of conservation concern. In animal studies, researchers realize that probabilities of detection of individuals are often less than one. Plants can also escape detection due to dormancy, herbivory, or observer error, but such information is rarely incorporated into population studies. 2We monitored a population of Asclepias meadii, a rare long-lived prairie perennial. Despite standardized methods, numbers of observed plants fluctuated greatly from 1992 to 2006. Individual plants often had periods of 1,5 years between initial and final sighting when no stems were found. To determine the actual population trajectories, we estimated rates of survival and population growth using mark-recapture models. We also estimated initial and resighting probabilities of detection. In 2007, we repeated surveys to identify reasons for low detection probabilities. 3We estimated 95% annual survival and a population growth rate of 1.023. Probabilities of initial detection were low (typically from 0.120 to 0.311 depending on prairie burn treatment), whereas average probability of detection for marked plants was 0.728. 4Comparisons of survival estimates from 15- and 8-year data sets revealed that survival estimates decline in the final years of a multi-year period, probably due to heterogeneity in encounter histories. 5By conducting three different surveys in 2007, we found that both herbivory over a multiple-week period and observer error contributed substantially to gaps in detection. 6Synthesis. Probabilities of detection that are less than one complicate interpretation of population dynamics, whether of mobile animals or inconspicuous plants. Our work illustrates three general points that could apply to many plant population studies: (i) mark-recapture models may provide insights on vital rates and population trajectories despite the extreme variability in count data that can arise because of low detectability, (ii) probabilities of initial detection can be quantified and can be considerably less than probabilities of resighting, and (iii) repeated surveys can help researchers determine the degree to which dormancy, herbivory, or observer error contribute to low probabilities of detection. Consideration of these points can improve the design and analysis of monitoring programs. [source]


Geographic patterns of diversity in streams are predicted by a multivariate model of disturbance and productivity

JOURNAL OF ECOLOGY, Issue 3 2006
BRADLEY J. CARDINALE
Summary 1Univariate explanations of biodiversity have often failed to account for broad-scale patterns in species richness. As a result, increased attention has been paid to the development and testing of more synthetic multivariate hypotheses. One class of multivariate hypotheses, founded in successional diversity theory, predict that species richness is jointly influenced by periodic disturbances that create new niche opportunities in space or time, and the production of community biomass that speeds displacement of inferior by superior competitors. 2While the joint response of diversity to disturbance and productivity has gained support from theoretical and small-scale experimental studies, evidence that corresponding patterns of biodiversity occur broadly across natural systems is scarce. 3Using a data set that employed standardized methods to sample 85 streams throughout the mid-Atlantic United States of America, we show that biogeographical patterns of primary producer diversity in stream ecosystems are consistent with the predictions of a multivariate model that incorporates disturbance frequency and community biomass production as independent variables. Periphyton species richness is a concave-down function of disturbance frequency (mean no. floods year,1) and of biomass production (µg of biomass accrual cm,2 day,1), and an increasing function of their interaction. 4Changes in richness across the disturbance × productivity response surface can be related to several predicted life-history traits of the dominant species. 5Our findings complement prior studies by showing that multivariate models which consider interactive effects of community production and ecosystem disturbance are, in fact, candidate explanations of much broader patterns of richness in natural systems. Because multivariate models predict synergistic effects of ecological variables on species diversity, human activities , which are simultaneously altering both the disturbance regime and productivity of streams , could be influencing biodiversity more than previously anticipated. [source]


The Intracoronary Electrocardiogram in Percutaneous Coronary Intervention

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 1 2009
ANDY SC YONG M.B.B.S.
The technique of obtaining an epicardial electrocardiogram trace by connecting the guidewire during coronary angioplasty to an electrocardiogram lead has been used since 1985. The intracoronary electrocardiogram appears to be more sensitive than the surface electrocardiogram in detecting transient ischemia, particularly in the territory of the left anterior descending and left circumflex coronary arteries. Importantly, recent studies have shown the intracoronary electrocardiogram to be particularly useful in demonstrating pre- and postconditioning during interventional procedures, predicting periprocedural myocardial damage, and in the determination of regional viability in the catheterization laboratory. Barriers to the use of the intracoronary electrocardiogram in the clinical setting include the lack of standardized methods for acquiring and analyzing the intracoronary electrocardiogram, and the lack of commercially available continuous intracoronary monitoring systems to permit analysis while performing coronary interventions. Facilitating these relatively simple technical developments may permit optimal integration of the intracoronary electrocardiogram into the catheterization laboratory. [source]


Elaboration and Validation of a Diagrammatic Scale for Epidemiological Studies of Cercospora Leaf Spot of Castor Bean

JOURNAL OF PHYTOPATHOLOGY, Issue 6 2010
Wellington Freire Dos Santos
Abstract The castor bean cercospora leaf spot (Cercospora ricinella Sacc. & Berl.) is a common disease in castor bean crop (Ricinus communis L.), causing defoliation and losses. In spite of this, the evaluation of disease severity is an important decision support for adoption of strategies and tactics for disease control. Therefore the objective of this work was to elaborate and to validate a diagrammatic to evaluate cercospora leaf spot severity in the castor bean. The scale was developed based on six treatments with different irrigation depths plus the control treatment without irrigation. Based on disease incidence analysis, it was possible to select different severity levels per treatment, which were used to define the percentage intervals of foliar diseased area of the diagrammatic scale. In view of the inexistence of standardized methods for the quantification of cercospora leaf spot in the field, the levels of 0%, 0.1 to 1%, 1.1 to 10%, 10.1 to 20% and 20.1 to 45% of lesioned foliar area were established, pointing out the observation that in the interval of 20 to 45% leaf fall started to occur. The scale was tested according its accuracy, precision and reproducibility. For that, 40 leaves with different disease severity levels were appraised by 10 users, without and with the scale, with an interval of seven days between evaluations of the same users. The appraisers obtained better results under utilization of the scale. The scale proposed in this work presented appropriate applicability for cercospora leaf spot evaluation in castor bean. Higher disease intensity was observed in the control and in treatments with higher irrigation depth and lower irrigation frequency. [source]


Comparison of Methods to Determine the Fracture Toughness of Three Glass-Ceramics at Elevated Temperatures

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2000
Janet B. Quinn
Two standardized methods for measuring kIc in ceramics are compared for use at high temperatures (precracked beam and surface crack in flexure). Results from a third technique involving the measurement of cracks around Vickers indentations are also presented. Three dental glass-ceramics, differing primarily in microstructure, were used as model materials in this study. They emphasized the importance of microstructure in determining high-temperature kIc values and the challenges in measuring them. The measured fracture toughnesses decreased with temperature and increased with imbedded grain size for all three methods. [source]


Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 24

JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2003
M Piatti
The present study was performed with the aim to compare different clinically-based neurotoxicity scales with a more extended composite scale (Total Neuropathy Scale) already validated in diabetic patients, in order to improve the grading of chemotherapy-induced peripheral neuropathy (CIPN) severity. The features of CIPN were evaluated in a series of women affected by locally advanced squamous cervical carcinoma treated with cisplatin and paclitaxel, based chemotherapy by clinical examination, neurophysiology and quantitative sensory testing of vibration threshold (VDT); the ECOG, Ajani and NCIC-CTC grades were assessed by a neurologist after clinical examination and the TNS was calculated after additional instrumental examination. At the same time, the treating oncologist, who was blinded as regards the results of the neurological examination, assessed the NCIC-CTC sensory neurotoxicity grade. The correlation existing between the different evaluations was evaluated with the Spearman test on a total of 97 visits. Our results indicate for all the neurotoxicity scales commonly used by oncologists and evaluated in this study a significant correlation with TNS; the interexaminer agreement comparison evaluation evidenced that in several cases the neurologist attributed a higher grade in the NCIC-CTC scale than the oncologist, and this discrepancy was mainly due to a different evaluation of the sensory impairment. In conclusion, the TNS can be used to assess effectively the severity of CIPN and the results of this evaluation can be reliably correlated with the oncological grading of sensory peripheral neurotoxicity; the wider range of TNS values, however, can allow a more accurate grading of the sensory impairment, a feature which can improve the estimate of CIPN changes, particularly in clinical trials; finally, the use of standardized methods of examination of the sensory function (e.g. the semiquantitative measure of vibration sensibility using the 128 Hz tuning fork) may reduce the interexaminer disagreement. [source]


Diagnostic utility of light transmission platelet aggregometry: results from a prospective study of individuals referred for bleeding disorder assessments

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2009
C. P. M. HAYWARD
Summary.,Background: Light transmission aggregometry (LTA) is commonly performed to assess individuals for bleeding disorders. Objectives: The goal was to evaluate the incidence and spectrum of platelet function abnormalities in a prospective cohort of individuals referred for bleeding disorder assessments after exclusion of thrombocytopenia and von Willebrand disease. Patients/methods: Subjects were healthy controls and patients from a prospective cohort of individuals referred for bleeding disorder assessments after exclusion of thrombocytopenia and von Willebrand disease. LTA was performed by standardized methods using platelet-rich plasma adjusted to 250 × 109 platelets L,1. Maximal aggregation data were analyzed to determine the likelihood of detecting a platelet function disorder by LTA, and the sensitivity and specificity of LTA for platelet disorders. Results: The incidence of false positive LTA among subjects excluded of having bleeding disorders was similar to healthy controls. Abnormal LTA was more common in subjects with bleeding disorders and the likelihood of a bleeding disorder was significantly increased (odds ratio 32) when maximal aggregation was reduced with two or more agonists. Receiver operator curve analyses indicated that LTA had high specificity and moderate sensitivity for detecting inherited defects in platelet function and that the LTA agonists 1.25 ,g mL,1 collagen, 6 ,M epinephrine, 1.6 mM arachidonic acid and 1.0 ,M thromboxane analogue U44619 detected most inherited disorders with abnormal LTA. Conclusions: LTA is valuable for detecting platelet function abnormalities among individuals referred for bleeding problems, particularly when the test indicates abnormal responses to multiple agonists. [source]


Platelet hyperreactivity generalizes to multiple forms of stimulation

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 9 2006
D. L. YEE
Summary.,Background:,Although platelet hyperreactivity constitutes an important cardiovascular risk factor, standardized methods for its measurement are lacking. We recently reported that aggregometry using a submaximal concentration of epinephrine identifies individuals with in vitro platelet hyperreactivity; this hyperreactivity was reproducible on multiple occasions over long periods of time. Objective and methods:,To better understand this aberrant reactivity, we studied in a large group of subjects (n = 386) the relationship between healthy individuals' platelet reactivity to epinephrine and their platelet phenotype as measured by other functional assays. Results:,Subjects with hyperreactivity to epinephrine were more likely to exhibit hyperfunction in each major aspect of platelet activity, including adhesion (response to low-dose ristocetin; P < 0.001), activation (surface P-selectin expression and PAC-1 binding after stimulation; P , 0.003) and aggregation to other agonists [no agonist, adenosine diphosphate (ADP), arachidonic acid, collagen, collagen-related peptide and ristocetin; P , 0.025] and to applied shear stress (PFA-100 and cone-and-plate viscometer; P < 0.05). These differences persisted after adjusting for demographic and hematologic differences between groups. We studied candidate genes relevant to epinephrine-mediated platelet activation and found that hyperreactivity to epinephrine was associated with a polymorphism on the gene (GNB3) encoding the beta-3 subunit of G proteins (P = 0.03). Conclusions:,Robust aggregation to a submaximal concentration of epinephrine establishes a true hyperreactive platelet phenotype that is ,global' as opposed to agonist specific; detection of this phenotype could be useful for studying patients at risk for arterial thrombosis. The mechanisms underlying hyperreactivity to different types of platelet stimulation may share common signaling pathways, some of which may involve specific G protein subunits. [source]


Stage Migration in Dogs with Lymphoma

JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2007
Andrea B. Flory
Background: Various diagnostic tests have been used to assign a clinical stage to dogs with lymphoma. As more sensitive staging methods are introduced, dogs are reclassified as having a higher disease stage, thereby affecting comparisons of dogs across differently staged clinical trials, and possibly, prognosis. Hypothesis: The addition of more sensitive staging tests causes stage migration in dogs with lymphoma. Animals: Fifty-nine client-owned dogs with previously untreated cytologically or histologically confirmed lymphoma Methods: For every dog, the World Health Organization stage classification (I-V) was based on 5 groupings of various diagnostic tests: A (physical examination [PE] and quantitative blood count [QBC]), B (PE, QBC, thoracic and abdominal radiographs), C (PE, complete blood count with blood-smear evaluation [CBC], thoracic and abdominal radiographs), D (PE, CBC, thoracic radiographs, abdominal ultrasound), and E (PE, CBC, thoracic radiographs, abdominal ultrasound, and bone-marrow cytology). Dogs were treated with doxorubicin-based protocols. Results: There was migration between all of the staging methods except D to E. However, the stage was not a predictor of remission rate, remission duration, or survival, regardless of staging method used. Conclusions and Clinical Importance: These data emphasized the need for standardized methods to determine the clinical stage in dogs with lymphoma. [source]


Deep brain stimulation for dystonia: Patient selection and evaluation

MOVEMENT DISORDERS, Issue S3 2002
Jens Volkmann MD
Abstract Deep brain stimulation (DBS) for dystonia still needs to be considered investigational, because there are no controlled studies for this indication, the optimal target point is uncertain, and long-term effects are unknown. The striking improvement of levodopa-induced dyskinesias in Parkinson's disease by deep brain stimulation of the internal pallidum has encouraged the use of this therapy for generalized and severe segmental dystonia in children and adults. Single case and small cohort studies have reported impressive efficacy of pallidal DBS in patients with primary dystonia, especially DYT1 mutation carriers, but results in secondary dystonia are less conclusive. This article discusses the different factors influencing patient selection for surgical treatment and describes standardized methods and the caveats for clinical documentation of treatment results in dystonia. © 2002 Movement Disorder Society [source]


Risk assessment of genetically modified crops for nutrition and health

NUTRITION REVIEWS, Issue 1 2009
Javier A Magaña-Gómez
The risk assessment of genetically modified (GM) crops for human nutrition and health has not been systematic. Evaluations for each GM crop or trait have been conducted using different feeding periods, animal models, and parameters. The most common result is that GM and conventional sources induce similar nutritional performance and growth in animals. However, adverse microscopic and molecular effects of some GM foods in different organs or tissues have been reported. Diversity among the methods and results of the risk assessments reflects the complexity of the subject. While there are currently no standardized methods to evaluate the safety of GM foods, attempts towards harmonization are on the way. More scientific effort is necessary in order to build confidence in the evaluation and acceptance of GM foods. [source]


Birth Defects Cluster Study: A national approach to birth defects cluster investigations,,

BIRTH DEFECTS RESEARCH, Issue 11 2008
James E. Kucik
Abstract BACKGROUND: Investigations of clusters of birth defects have been challenging endeavors that have had only modest success identifying causes or risk factors. Some of the challenges to individual cluster investigations have been small sample size and limited data collection. We describe a novel approach for investigating and analyzing pooled information from a series of birth defects cluster investigations. METHODS: The Birth Defects Cluster Study uses a case-control study design with standardized methods, including a case definition, control selection, data collection methods, and data collected (e.g., maternal interviews, blood samples, and environmental samples). Analyses of pooled data from several clusters of the same defect are conducted for specific hypotheses once a sufficient sample size has been achieved. The feasibility of conducting individual birth defect investigations was evaluated on a cluster of gastroschisis. RESULTS: The pilot investigation of a cluster of gastroschisis demonstrated success in recruiting participants and in collecting data and specimens for eventual inclusion in a pooled analysis. CONCLUSIONS: The Birth Defects Cluster Study offers a unique and effective approach to cluster investigations that improves the likelihood of identifying genetic and environmental causes of birth defects and provides a model for cluster investigations of other noninfectious health outcomes. Birth Defects Research (Part A), 2008. Published 2008 Wiley-Liss, Inc. [source]


The impact of targeted training, a dedicated protocol and on-site training material in reducing observer variability of prostate and transition zone dimensions measured by transrectal ultrasonography, in multicentre multinational clinical trials of men with symptomatic benign prostatic enlargement

BJU INTERNATIONAL, Issue 1 2007
Philip S. Murphy
OBJECTIVE To assess the variability of a standardized protocol of transrectal ultrasonography (TRUS), with targeted training, and compare it to the variability in other multicentre clinical trials, as TRUS-estimated total prostate volume (TPV) and transition zone volume (TZV) are considered important efficacy endpoints in assessing new drug therapies for benign prostatic enlargement (BPE), but standardizing TRUS remains a challenge in such studies. PATIENTS AND METHODS In all, 174 patients with BPE in the placebo arm of a 30-centre clinical trial were analysed at baseline, 13 and 26 weeks with TRUS, to extract TPV and TZV values. All TRUS operators received training in the standardized methods, which was supplemented at the outset by a compact disc-based video. RESULTS The mean (sd) changes from baseline in TPV at 13 and 26 weeks were ,,2.9 (8.9) and ,1.9 (8.5) mL, respectively; the respective mean changes from baseline in TZV were ,1.2 (6.4) and +,0.7 (7.8) mL. For TPV, 80% of the measurements had differences of +,5.2 to ,13.4 mL at 13 weeks, and +,8.0 to ,,10.9 mL at 26 weeks. For TZV, 80% of the differences were +,5.8 to ,,7.4 at 13 weeks, and +,9.3 to ,6.5 mL at 26 weeks. CONCLUSION The performance of TRUS compared favourably with similar published multicentre studies, which we suggest relates in part to the careful implementation of the protocol. We showed that diligent implementation of a detailed protocol, supplemented by targeted training of investigators and provision of on-site training material, promoted consistent acquisition and successful derivation of key clinical trial endpoints. Quantifying the variability of such endpoints will enable us to track deployment quality for future clinical trials, and will ensure that trials are sufficiently powered to define small changes in prostate size. [source]