Additional Testing Procedures Research Articles

Gaps in predicting water quality impacts of unbound air-cooled blast furnace slag utilized for roadway construction

Air-cooled blast furnace slag (ACBFS) is often used as road construction aggregate. Several incidences of adverse environmental effects have been reported in Indiana where unbound slag has been used. The aggregates that caused issues in the field had been previously approved for use by passing State of Indiana standard slag leaching procedures. The study goal was to test several hypotheses posed to the Indiana Department of Transportation and authors by the industry about slag leaching, and to better understand water quality impacts. Ten slags from two suppliers underwent leaching procedures adopted by two U.S. states, but additional test procedures and material and leachate chemical characterization were also conducted to better interpret results. Aggregates varied in size and age (24 h to 2 years old). Like prior literature reports, the chemical composition among the slag samples was similar. However, water quality impacts observed at the bench-scale in this study differed substantially across the slags. Results were consistent with those previously reported at Indiana field sites, but not with literature reported results from standardized leaching tests (i.e., TCLP, percolation, etc.). In the present study, no relationship was found between slag age and leachate composition. Leachate pH, conductivity, and color levels exceeded thresholds of regulatory and aquatic toxicity significance. For one slag, leachate pH reached 12.9, but the effluent was colorless. During both stagnation and rinsing tests, aqueous chloride, sulfate, and zinc concentrations sometimes exceeded regulatory water quality and aquatic toxicity levels. Repeated rinsing of the slag resulted in water conductivity and sulfate concentration differences. To better understand and predict the impacts of unbound ACBFS, additional fundamental studies and field investigations are recommended. Unbound ACBFS is not recommended for use near environmentally sensitive areas, drinking water sources, habituated areas, and where it may have water contact (i.e., waterways, wetlands, reservoirs, and groundwater).

Hirayama Disease: the importance of the differential diagnosis in suspected neural leprosy

Pure neural leprosy, leprosy without skin manifestations, is common in leprosy. Patients with muscle weakness or paralysis without the classical leprosy cardinal signs, such as the typical skin lesions and skin smear positivity, are sometimes erroneously diagnosed as having neural leprosy. Sound knowledge of the innervation pattern of nerves that can become involved in leprosy can help differentiate pure neural leprosy from other neuromuscular conditions. Simple clinical testing procedures can aid in the differential diagnosis. When in doubt of a diagnosis, additional testing procedures can confirm or reject a diagnosis of neural leprosy. Hirayama Disease is a relatively rare disease of the lower cervical spine which presents mainly as paralysis of the forearm and hand muscles. We report four patients with Hirayama Disease referred to and diagnosed at one leprosy referral center. One patient was treated for leprosy before the diagnosis of Hirayama Disease. Clinical differentiation between the two neural diseases is relatively easy.

The Role of Anti-HBc Testing on Donor Selection and Its Contribution to Current Alghorithms; Can the Gülhane Experience Be a Model for Turkey?

Additional or different test procedures can be applied to maximize transfusion safety by reducing the risk of transfusion-transmitted infections. Antibodies to hepatitis B core antigen (anti-HBc) is one of the most commonly used serologic marker in this context. The aim of the study was to analyse anti-Hbc test results performed within the scope of routine screening tests in our center and to examine the effect of the donor re-entry protocol established. A total of 57191 people who applied to Gülhane Regional Blood Center to donate blood between 2014-2019 were included in the study. All blood donations were screened for anti-HBc by chemiluminescense immunoassay (Architect i2000 SR, AXSYM, Abbott, IL, USA). Hepatitis B surface antibody (anti-HBs) and hepatitis B virus (HBV) deoxyribonucleic acid (DNA) (ABI Prism 7500 Real time PCR system, Applied Biosystems, USA) tests were performed in accordance with the donor recovery protocol for those who could be reached among those with positive for anti-HBc test results. Samples with > 100 IU/ml of anti-HBs levels and negative for HBV DNA test were included in the donor pool. Of the 57 191 blood donors involved in the study, 5125 (8.5%) were found as positive for anti-HBc. Of the donors, 54 035 (94.4%) were male and 3156 (5.5%) were female. The difference was found to be statistically significant in terms of gender distribution between the years of the study (p<0.001). The highest anti-HBc positivity rate (35.7%) was in the age group of 60 years and over while the lowest positivity rate (3.8%) was in the age group of 18-30 years (r= 0.549, p= 0.0001). The year with the highest anti-HBc seroprevalance (10.1%) was 2017, while the year with the lowest (7.9%) was 2014. The distribution of seropositivity over the years was statistically significant (p<0.001). In the study, anti-HBs and HBV-DNA test results of 439 donors were accessible and of which 301 (68.5%) were considered eligible to donate again according to the re-entry protocol. The isolated anti-HBc positivity and HBV-DNA positivity rates were 7.5% (33/430) and 0.2% (1/439) respectively,in blood donors to whom re-entry protocol was performed. The seroprevalance of anti-HBc below 10% during the six-year period in which the study was conducted is a critical data for the evaluation of this test within the scope of routine microbiological screening tests. Moreover, we have observed that donor losses due to the antiHBc testing can be significantly reduced with the implementation of donor re-entry protocols. Anti-HBc screening strategy should be decided by considering of HBV epidemiology, cost-effectivity and possible blood donor losses.

Additional randomization test procedures for the changing criterion design

AbstractThe single‐point and range‐bound changing criterion design have been proposed as single‐case experimental designs. The only form of randomization currently available for these designs is phase change moment randomization. The present article describes two novel randomization procedures for changing criterion designs, the blocked alternating criterion randomization and randomized alternating criterion randomization, and illustrates their use. Appropriate randomization procedures are introduced for situations in which it is desirable to maintain the stepwise nature of the changing criterion design and situations in which the change in the dependent variable can be assumed not to follow the stepwise pattern. The article further discusses contexts in which each of the randomization procedures for the changing criterion design may be useful, and explains how the procedures maintain the researcher's flexibility.

Instantaneous Cardiac Baroreflex Sensitivity: xBRS Method Quantifies Heart Rate Blood Pressure Variability Ratio at Rest and During Slow Breathing.

Spontaneous baroreflex sensitivity (BRS) is a widely used tool for the quantification of the cardiovascular regulation. Numerous groups use the xBRS method, which calculates the cross-correlation between the systolic beat-to-beat blood pressure and the R-R interval (resampled at 1 Hz) in a 10 s sliding window, with 0–5 s delays for the interval. The delay with the highest correlation is selected and, if significant, the quotient of the standard deviations of the R-R intervals and the systolic blood pressures is recorded as the corresponding xBRS value. In this paper we test the hypothesis that the xBRS method quantifies the causal interactions of spontaneous BRS from non-invasive measurements at rest. We use the term spontaneous BRS in the sense of the sensitivity curve is calculated from non-interventional, i.e., spontaneous, baroreceptor activity. This study includes retrospective analysis of 1828 measurements containing ECG as well as continues blood pressure under resting conditions. Our results show a high correlation between the heart rate – systolic blood pressure variability (HRV/BPV) quotient and the xBRS (r = 0.94, p < 0.001). For a deeper understanding we conducted two surrogate analyses by substituting the systolic blood pressure by its reversed time series. These showed that the xBRS method was not able to quantify causal relationships between the two signals. It was not possible to distinguish between random and baroreflex controlled sequences. It appears xBRS rather determines the HRV/BPV quotient. We conclude that the xBRS method has a potentially large bias in characterizing the capacity of the arterial baroreflex under resting conditions. During slow breathing, estimates for xBRS are significantly increased, which clearly shows that measurements at rest only involve limited baroreflex activity, but does neither challenge, nor show the full range of the arterial baroreflex regulatory capacity. We show that xBRS is exclusively dominated by the heart rate to systolic blood pressure ratio (r = 0.965, p < 0.001). Further investigations should focus on additional autonomous testing procedures such as slow breathing or orthostatic testing to provide a basis for a non-invasive evaluation of baroreflex sensitivity.

Water retention curve of GCLs using a modified sample holder in a chilled-mirror dew-point device

The aim of this study is to assess the feasibility of using a modified chilled-mirror dew-point apparatus to quantify the water retention curve of GCLs. The conventional configuration of the chilled-mirror dew-point device allows the measurements of water potentials under zero confinement pressure condition only. A simple approach is proposed in this study to enable the chilled-mirror dew-point device to measure GCLs water retention curves on the wetting path in terms of the upper and the lower boundaries of the confining conditions (i.e., free swelling and constant volume condition, respectively). The proposed method needs neither additional equipment nor special test procedures. The test results obtained from this study are discussed in the light of the results reported in the literature where emphasis was on the effect of confinement condition on the water retention curves of GCLs and a satisfactory agreement is observed.

Evaluating aging in cats: How to determine what is healthy and what is disease.

Many of the changes that occur with aging are not considered pathologic and do not negatively affect overall wellness or quality of life. Ruling out disease is essential, however, when attempting to determine whether an aged cat can be considered 'healthy'. A clear understanding of the normal and abnormal changes that are associated with aging in cats can help practitioners make decisions regarding medical management, feeding interventions and additional testing procedures for their aged patients. It can be difficult to determine if a cat is displaying changes that are appropriate for age. For example, healthy aged cats may have hematologic or serum biochemistry changes that differ from those of the general feline population. Assessment of behavioral health and cognitive changes, as well as auditory, olfactory and visual changes, can also be challenging in the aged patient. This is the second of two review articles in a Special Issue devoted to feline healthy aging. The goals of the project culminating in these publications included developing a working definition for healthy aging in feline patients and identifying clinical methods that can be used to accurately classify healthy aged cats. This second review proposes criteria for assessing 'healthy aged cats'. There is a paucity of research in feline aging. The authors draw on expert opinion and available data in both the cat and other species.

On-Road and Chassis Dynamometer Evaluations of Emissions from Two Euro 6 Diesel Vehicles

The exhaust emissions of two Euro 6 diesel cars with different emissions control systems have been evaluated both on the road and over various chassis dynamometer test cycles. European emissions limits are currently set using the New European Driving Cycle (NEDC), but the European Commission is preparing additional test procedures to ensure that emissions are well controlled both in real-world use and over the legislative test cycle. The main focus of this work on ‘Real Driving Emissions’ (RDE) is on measurements using Portable Emissions Measurement Systems (PEMS) in truly representative, on-road, driving. A key focus of the test programme, undertaken as a collaboration between AECC (the Association for Emissions Control by Catalyst) and Ricardo UK, was therefore the use of PEMS systems to measure on-road emissions of both gaseous pollutants and particulate matter. This included measurement of particle number emissions with a new candidate system for this type of measurement. The results from this testing are compared with emissions measured over four different chassis dynamometer test cycles the current legislative cycle (New European Driving Cycle, NEDC); the Common Artemis suite of test cycles (CADC) that is widely used in emissions modelling; the new Worldwide Light-duty Test Cycle (WLTC) defined by the UN Working Party on Pollution and Energy (GRPE) as part of the development of the Worldwide harmonised Light vehicles Test Procedure (WLTP); and a set of cycles produced by a Random Cycle Generator based on ‘short trip’ segments from the EU database used to construct WLTC. This Random Cycle (RC) approach was originally considered by the European Commission and Member States as an alternative to PEMS measurements, but remains an option for particle number measurement should PEMS instrumentation not be fully available by the time such measurements are required by legislation. The aim of this test programme was to evaluate the emissions performance of two different vehicles when using PEMS systems in real-life driving, and to identify and help understand the differences in emissions that may arise between the various test procedures. The test results show the differing vehicle emissions performances that may be encountered in real-driving for two vehicles that both meet the Euro 6 limits in Type-Approval laboratory testing. The results show that in some cases the on-road PEMS-measured emissions for complete test routes can exceed Type-Approval limits, and indicate that real-world conditions require more robust control strategies over those needed to satisfy existing legislation. CITATION: Andersson, J., May, J., Favre, C., Bosteels, D. et al., On-Road and Chassis Dynamometer Evaluations of Emissions from Two Euro 6 Diesel Vehicles, SAE Int. J. Fuels Lubr. 7(3):2014, doi:10.4271/2014-01-2826. 2014-01-2826 Published 10/13/2014 Copyright © 2014 SAE International doi:10.4271/2014-01-2826 saefuel.saejournals.org Downloaded from SAE International by Cecile Favre, Monday, October 13, 2014

Cost benefit analysis of mesh reinforcement of stapled left pancreatectomy

ObjectivesPancreatic leak is a morbid complication following left pancreatectomy, which results in prolonged hospitalization, additional diagnostic testing and invasive procedures. The present authors have previously demonstrated that mesh reinforcement of stapled left pancreatectomy results in fewer pancreatic leaks. This study was conducted to investigate whether mesh reinforcement also results in cost benefits for the health care system. MethodsA cost benefit model was developed to estimate net cost savings from the payer's perspective. The model is based on the results of a randomized, single-blinded trial of mesh versus no mesh reinforcement of the pancreatic remnant after left pancreatectomy. A two-way sensitivity analysis was conducted to determine the model's sensitivity to fluctuations in the cost of mesh and the effectiveness of the mesh in reducing clinically significant leaks. ResultsAverage total costs for an episode of care were US$13337 and US$15505 for patients who did and did not receive mesh, respectively, which indicates savings of US$2168. Two-way sensitivity analysis showed that, given a probability of 1.9% for developing a clinically significant leak in patients in whom mesh reinforcement was used, the strategy would continue to save costs if mesh were priced at ≤US$1804. ConclusionsMesh reinforcement decreases clinically significant pancreatic leaks. Despite the additional cost of mesh reinforcement, the use of mesh reinforcement results in overall cost savings for the health care system because of the resultant decrease in the occurrence of clinically significant leaks.

1360 COMPARATIVE EFFECTIVENESS OF SLING SURGERY IN MEDICARE BENEFICIARIES

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Incontinence, Evaluation & Therapy (III)1 Apr 20131360 COMPARATIVE EFFECTIVENESS OF SLING SURGERY IN MEDICARE BENEFICIARIES Anne M. Suskind, J. Quentin Clemens, Rodney L. Dunn, John M. Hollingsworth, Zhang Yun, Bruce L. Jacobs, Florian R. Schroeck, and Brent K. Hollenbeck Anne M. SuskindAnne M. Suskind Ann Arbor, MI More articles by this author , J. Quentin ClemensJ. Quentin Clemens Ann Arbor, MI More articles by this author , Rodney L. DunnRodney L. Dunn Ann Arbor, MI More articles by this author , John M. HollingsworthJohn M. Hollingsworth Ann Arbor, MI More articles by this author , Zhang YunZhang Yun Ann Arbor, MI More articles by this author , Bruce L. JacobsBruce L. Jacobs Ann Arbor, MI More articles by this author , Florian R. SchroeckFlorian R. Schroeck Ann Arbor, MI More articles by this author , and Brent K. HollenbeckBrent K. Hollenbeck Ann Arbor, MI More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.2714AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Regulatory agencies have expressed concerns about the use of vaginally placed mesh for stress urinary incontinence. In order to address these concerns, we compared outcomes of mesh versus non–mesh slings in Medicare beneficiaries. METHODS We performed a retrospective cohort study of Medicare beneficiaries undergoing sling surgery from 2006 to 2008 in hospital outpatient departments and in hospital based ambulatory surgery centers using a 20% national sample of claims. An algorithm was developed using “C” HCPCS (Healthcare Common Procedure Coding System) codes to categorize slings as using either mesh or non–mesh materials. Each subject was followed for 1 year after their procedure for the following outcomes: complications, diagnosis and management of outlet obstruction, additional testing, and additional incontinence procedures. Logistic regression was used to determine the odds of each complication based on whether slings were placed with mesh versus non–mesh materials and whether differences reflected the place of service. RESULTS There were 6,698 mesh and 445 non–mesh sling procedures performed in Medicare beneficiaries between 2006–2008. Demographic characteristics were comparable between groups. There were no statistically significant differences between groups for post–operative urologic complications, infectious complications, new diagnoses of urgency, pelvic pain, or bladder outlet obstruction, or for repeat incontinence procedures (see Table). Procedures associated with the management of bladder outlet obstruction; however, were significantly higher among beneficiaries who received non–mesh compared to mesh slings, at 19.3% versus 13.9% (p<0.01), with an odds ratio of 1.5 (95% CI 1.18–1.92, p<0.01). Place of service was not a predictor of the type of material used, with a 1.20 odds (95% CI 0.66, 2.17, p=0.55) of having a mesh sling performed in a hospital based ambulatory surgery center compared to a hospital outpatient department. CONCLUSIONS Complications after sling surgery were uncommon regardless of whether mesh was used and were not affected by the setting of the surgery. Our findings suggest that mesh used for SUI is not associated with increased complications within 1 year of surgery. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e556 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Anne M. Suskind Ann Arbor, MI More articles by this author J. Quentin Clemens Ann Arbor, MI More articles by this author Rodney L. Dunn Ann Arbor, MI More articles by this author John M. Hollingsworth Ann Arbor, MI More articles by this author Zhang Yun Ann Arbor, MI More articles by this author Bruce L. Jacobs Ann Arbor, MI More articles by this author Florian R. Schroeck Ann Arbor, MI More articles by this author Brent K. Hollenbeck Ann Arbor, MI More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Ultra-trace analysis of hormones, pharmaceutical substances, alkylphenols and phthalates in two French natural mineral waters

The aim of this work was to investigate the potential presence of a broad range of organic compounds, such as hormones, alkylphenols, bisphenol A and phthalates, as well as pharmaceutical substances in two brands of bottled natural mineral waters (Evian and Volvic, Danone). The phthalates were determined by solid-phase microextraction coupled to gas chromatography–mass spectrometry (SPME-GC–MS) and the other compounds by liquid chromatography–tandem mass spectrometry (LC–MS/MS) or gas chromatography–mass spectrometry (GC–MS) after solid-phase extraction. The potential migration of alkylphenols, bisphenol A and phthalates from polyethylene terephthalate (PET) bottles was also investigated under standardized test conditions. Evian and Volvic natural mineral waters contain none of the around 120 targeted organic compounds. Traces of 3 pharmaceuticals (ketoprofen, salicylic acid, and caffeine), 3 alkylphenols (4-nonylphenol, 4-t-octylphenol, and 4-nonylphenol diethoxylate), and some phthalates including di(2-ethylhexyl)phthalate (DEHP) were detected in the samples, but they were also present in the procedural blanks at similar levels. The additional test procedures demonstrated that the few detected compounds originated from the background laboratory contamination. Analytical procedures have been designed both in the bottling factory and in the laboratory in order to investigate the sources of DEHP and to minimize to the maximum this unavoidable laboratory contamination. It was evidenced that no migration of the targeted compounds from bottles occurred under the test conditions. The results obtained in this study underline the complexity of reaching a reliable measure to qualify the contamination of a sample at ultra-trace level, in the field of very pure matrices. The analytical procedures involving glassware, equipment, hoods, and rooms specifically dedicated to trace analysis allowed us to reach reliable procedural limits of quantification at the ng/L level, by lowering the background laboratory contamination.

New evidence for underwriting cycles in US property‐liability insurance

Purpose – The purpose of this paper is to highlight some testing procedures, both in time/frequency framework, useful to test for significant cycles in insurance data. The US underwriting cycle is measured using the growth rates of real premiums. Design/methodology/approach – In addition to the traditional AR(2) model, two new approaches are suggested: testing for a significant peak in the periodogram using Fisher g test and a nonparametric version of it, and testing for unit root cycles in insurance data. Findings – All approaches find empirical evidence for a cyclical behaviour of the growth rates of property-liability real premiums. Results on the length of dominant cycle still diverge, according to the approach (time/frequency domain). Originality/value – Compared to the existing literature, the present study innovates in that it highlights additional testing procedures, helpful to detect significant cycles in insurance time series. The underwriting cycle is analysed through the growth rates of real premiums.

Simple method for correcting dynamic cone penetration test results for rod friction

This letter presents a simple method for evaluating the effect of rod skin friction on dynamic cone penetration test results in cohesive soils. The proposed method is simple and requires neither additional equipment nor special test procedures, and thus represents an improvement on existing dynamic probing practice. In a field trial, the proposed approach was shown to work well when compared with the results of a special dynamic cone test where a casing was used to reduce the effect of rod skin friction. However, more field tests at different ground conditions are required to fully confirm the validity of the proposed approach.

MULTIDISCIPLINARY PAIN ABSTRACTS: 31 . Neurology (31)

Complex regional pain syndrome (CRPS) is clinically characterized by sensory, autonomic and motor disturbances. Pathophysiologically there is evidence for functional changes within the central nervous system and for involvement of peripheral inflammatory processes. The sympathetic nervous system plays a key role in maintaining pain and autonomic dysfunction in the affected extremity. After a primary central lesion, secondary peripheral changes in the paretic extremity are suggested to be important in initiating a CRPS. Though there is no diagnostic gold standard, careful clinical evaluation and additional test procedures should lead to an adequate diagnosis. An early diagnosis and an interdisciplinary approach are important for optimal and successful treatment.

Recent trends in understanding and therapy of complex regional pain syndromes

Since the term "complex regional pain syndromes" (CRPS) was introduced based on a revised taxonomy for disorders previously called reflex sympathetic dystrophy and causalgia in 1995, much knowledge grew up on the understanding and therapy of the disease. This review gives an overview on the clinical characteristics, pathophysiology, diagnostic tools and therapeutic options in CRPS. It will especially focus on recent findings on the role of the sympathetic nervous system, the central nervous system and peripheral inflammatory processes as underlying mechanisms. Although there is no diagnostic gold standard, careful clinical evaluation and additional apparative test procedures are very helpful for the diagnosis. An early and interdisciplinary approach is the basis for an optimal and successful treatment.

Bioeffects of ultrasound with contrast agents: in vitro

Historical data are briefly reviewed to demonstrate the very large variability inherent in inter-trial replications of ultrasound (US)-induced hemolysis in vitro with or without the presence of echo contrast agents. Statistical analyses of such widespread data for specific comparative tests are undertaken and compared with those of “clinical titration procedures” in which “dose” is administered to achieve a specific effect from which additional testing procedures can then be undertaken for comparative assays. Use of this “titration procedure” is then applied to the testing of four hypotheses related to environmental and biological factors associated with US-induced hemolysis in vitro. For each hypothesis, anticoagulated whole human blood in vitro in the presence of a clinical concentration of an echo contrast agent (Albunex®) was used. The four hypotheses are that: 1) cell size is an important factor in US-induced hemolysis, the larger the cell the greater the hemolytic yield; 2) the antioxidant Trolox®, an analogue for Vitamin E, causes a “kink” in the bilipid membrane layer with resulting physical instability and hence increased potential for US-induced hemolysis; 3) the extent of gas content as reflected by the partial pressure of oxygen in the blood determines the extent of US-induced hemolysis, the higher the gas content the greater the US-induced hemolytic yield; and 4) temperature can affect the fragility of the cell membrane and lead to increased US-induced hemolysis. The results are related to the occurrence of US-induced inertial cavitation.

Complex regional pain syndrome--diagnostic, mechanisms, CNS involvement and therapy.

Complex regional pain syndromes (CRPS, formerly reflex sympathetic dystrophy and causalgia) are neuropathic pain conditions of one extremity developing inadequately after a trauma. The initiating trauma affects primarily the extremity, but can also be a central lesion (e.g., spinal cord injury, stroke). CRPS is clinically characterized by sensory, autonomic and motor disturbances. Pathophysiologically there is evidence for functional changes within the central nervous system and for involvement of peripheral inflammatory processes. The sympathetic nervous system plays a key role in maintaining pain and autonomic dysfunction in the affected extremity. After a primary central lesion, secondary peripheral changes in the paretic extremity are suggested to be important in initiating a CRPS. Though there is no diagnostic gold standard, careful clinical evaluation and additional test procedures should lead to an adequate diagnosis. An early diagnosis and an interdisciplinary approach are important for optimal and successful treatment.

Rate-drop response programming.

Effective programming of the rate-drop response algorithm requires careful attention to the heart rate and blood pressure responses seen during diagnostic tilt testing. In order to undertake effective programming, additional tilt testing procedures may be necessary, and it is vital that the protocol should be identical on each occasion and very careful note taken of exact times of onset of symptoms and relative timing of onset of changes in heart rate and blood pressure. The algorithm settings in the Thera DR generator as delivered (factory or "shelf" parameter settings) must be considered nontherapeutic (an unusual situation for a pacemaker algorithm) and will require adjustment for each individual patient. Effective therapeutic settings are likely to result in an excess of pacing interventions; these, however, tend to be less symptomatic than the syncope or presyncope suffered by the patient and are generally well tolerated or not noticed.

Failed back surgery syndrome. Part I: Analysis of the clinical presentation and results of testing procedures for instability of the lumbar spine in 171 patients.

The clinical presentation and diagnostic approach in 171 patients with a failed back surgery syndrome is presented and analyzed with respect to the mode of the primary discectomy-approach and type of resulting instability as well as results of internal fixation. The clinical picture and physical signs are quite distinct but the indication for internal fixation is only obvious in the presence of positive results of additional testing procedures such as the anaesthesia of articular nerves and trial immobilisation in a plaster jacket. Different types of instability of the lumbar spine occur in relation to the mode of the primary and/or secondary discectomy-approach(es). By application of this diagnostic protocol excellent, good, satisfactory, moderate and poor results were obtained in 87 (53%), 42 (26%), 23 (14%), 9 (6%), and 2 (1%) patients, respectively (final evaluation was possible in 163 patients).

Errors and testing of computerised measuring instruments

Computerised measuring instruments require additional definitions, theories and testing procedures for the errors caused by computer and associated software. An overview will be given and explained by means of a few examples. Some conclusions are drawn for accuracy testing of computerised measuring instruments.