bluuebunny/crossref_metadata_2025 huggingface dataset:
Transforming growth factor-beta (TGF-β) in acute injuries of the spinal cord
Authors: Quinlan J. F. , Watson R. W. G. , Kelly G. , Kelly P. M. , O’Byrne J. M. , Fitzpatrick J. M.
Published: February 2006

Injuries to the spinal cord may be associated with increased healing of fractures. This can be of benefit, but excessive bone growth can also cause considerable adverse effects.

We evaluated two groups of patients with fractures of the spinal column, those with neurological compromise (n = 10) and those without (n = 15), and also a control group with an isolated fracture of a long bone (n = 12). The level of transforming growth factor-beta (TGF-β), was measured at five time points after injury (days 1, 5, 10, 42 and 84).

The peak level of 142.79 ng/ml was found at day 84 in the neurology group (p < 0.001 vs other time points). The other groups peaked at day 42 and had a decrease at day 84 after injury (p ≤ 0.001).

Our findings suggest that TGF-β may have a role in the increased bone turnover and attendant complications seen in patients with acute injuries to the spinal cord.
Does obesity influence the clinical outcome at five years following total knee replacement for osteoarthritis?
Authors: Amin A. K. , Patton J. T. , Cook R. E. , Brenkel I. J.
Published: February 2006

A total of 370 consecutive primary total knee replacements performed for osteoarthritis were followed up prospectively at 6, 18, 36 and 60 months. The Knee Society score and complications (perioperative mortality, superficial and deep wound infection, deep-vein thrombosis and revision rate) were recorded. By dividing the study sample into subgroups based on the body mass index overall, the body mass index in female patients and the absolute body-weight. The outcome in obese and non-obese patients was compared. A repeated measures analysis of variance showed no difference in the Knee Society score between the subgroups. There was no statistically-significant difference in the complication rates for the subgroups studied. Obesity did not influence the clinical outcome five years after total knee replacement.
Club foot
Authors: Engell V. , Damborg F. , Andersen M. , Kyvik K. O. , Thomsen K.
Published: February 2006

The aetiology of congenital club foot is unclear. Although studies on populations, families and twins suggest a genetic component, the mode of inheritance does not comply with distinctive patterns.

The Odense-based Danish Twin Registry contains data on all 73 000 twin pairs born in Denmark over the last 130 years. In 2002 all 46 418 twins born between 1931 and 1982 received a 17-page questionnaire, one question of which was ‘Were you born with club foot?’ A total of 94 twins answered ‘Yes’, giving an overall self-reported prevalence of congenital club foot of 0.0027 (95% confidence interval (CI) 0.0022 to 0.0034). We identified 55 complete twin pairs, representing 12 monozygotic, 22 dizygotic same sex (DZss), 18 dizygotic other sex (DZos) and three unclassified. Two monozygotic and 2 DZss pairs were concordant. The pairwise concordance was 0.17 (95% CI 0.02 to 0.48) for monozygotic, 0.09 (95% CI 0.01 to 0.32) for DZss and 0.05 (95% CI 0.006 to 0.18) for all dizygotic (DZtot) twins.

We have found evidence of a genetic component in congenital club foot, although non-genetic factors must play a predominant role.
A benign psoas mass following metal-on-metal resurfacing of the hip
Authors: Boardman D. R. , Middleton F. R. , Kavanagh T. G.
Published: February 2006

As metal-on-metal arthroplasty becomes more widespread, concerns are being raised about the potential dangers of metal particulate debris. We present the case of a benign psoas mass secondary to the presence of such particles. The mass was excised and the hip resurfacing subsequently revised to a total hip replacement.
Does anterior cruciate ligament reconstruction restore normal knee kinematics?
Authors: Scarvell J. M. , Smith P. N. , Refshauge K. M. , Galloway H. R. , Woods K. R.
Published: February 2006

This prospective study used magnetic resonance imaging to record sagittal plane tibiofemoral kinematics before and after anterior cruciate ligament reconstruction using autologous hamstring graft. Twenty patients with anterior cruciate ligament injuries, performed a closed-chain leg-press while relaxed and against a 150 N load. The tibiofemoral contact patterns between 0° to 90° of knee flexion were recorded by magnetic resonance scans. All measurements were performed pre-operatively and repeated at 12 weeks and two years.

Following reconstruction there was a mean passive anterior laxity of 2.1 mm (sd 2.3), as measured using a KT 1000 arthrometer, and the mean Cincinnati score was 90 (sd 11) of 100. Pre-operatively, the medial and lateral contact patterns of the injured knees were located posteriorly on the tibial plateau compared with the healthy contralateral knees (p = 0.014), but were no longer different at 12 weeks (p = 0.117) or two years postoperatively (p = 0.909). However, both reconstructed and healthy contralateral knees showed altered kinematics over time. At two years, the contact pattern showed less posterior translation of the lateral femoral condyle during flexion (p < 0.01).
Cyclic pneumatic soft-tissue compression accelerates the union of distal radial osteotomies in an ovine model
Authors: Challis M. J. , Gaston P. , Wilson K. , Jull G. A. , Crawford R.
Published: February 2006

The aim of this randomised, controlled in vivo study in an ovine model was to investigate the effect of cylic pneumatic pressure on fracture healing. We performed a transverse osteotomy of the right radius in 37 sheep. They were randomised to a control group or a treatment group where they received cyclic loading of the osteotomy by the application of a pressure cuff around the muscles of the proximal forelimb. Sheep from both groups were killed at four or six weeks. Radiography, ultrasonography, biomechanical testing and histomorphometry were used to assess the differences between the groups. The area of periosteal callus, peak torsional strength, fracture stiffness, energy absorbed over the first 10° of torsion and histomorphometric analysis all showed that the osteotomies treated with the cyclic pneumatic pressure at four weeks were not significantly different from the control osteotomies at six weeks.
Influence of the design of the prosthesis on the outcome after hemiarthroplasty of the shoulder in displaced fractures of the head of the humerus
Authors: Loew M. , Heitkemper S. , Parsch D. , Schneider S. , Rickert M.
Published: February 2006

We reviewed 39 patients with displaced three- and four-part fractures of the humerus. In 21 patients (group A) we had used an anatomical prosthesis for the humeral head and in 18 (group B) an implant designed for fractures.

When followed up at a mean of 29.3 months after surgery the overall Constant score was 51.9 points; in group A it was 51.5 and in group B 52.4 points. The subjective satisfaction of the patients was assessed using a numerical rating scale and was similar in both groups. In group A complete healing of the tuberosities was found in 29% and 50% in group B. Partial integration was seen in 29% of group A and in only one patient in group B, while resorption was noted in 43% of group A and 44% of group B. The functional outcome was significantly better in patients with complete or partial healing of the tuberosities (p = 0.022). The specific trauma prosthesis did not lead to better healing of the tuberosities. The difference in clinical outcome obtained by the two designs did not reach statistical significance.
Compartment syndrome following total knee arthroplasty
Authors: Haggis P. , Yates P. , Blakeway C. , Fick D. , Morgan D. A. F. , Holt M. , Wood D.
Published: February 2006

Compartment syndrome is a rare complication of total knee arthroplasty that requires early recognition and prompt decompression in order to prevent long-term disability. We have found only one previous case report in the literature. We present a series of seven cases from four hospitals and five surgeons. Six of the cases resulted in the loss of at least one compartment, and one resulted in amputation. Four of the cases resulted in legal action.

We suggest that important risk factors contributing to the development of this condition include complex surgery, soft-tissue compromise, previous surgery, and possibly vascular disease. Delay in the diagnosis and hence delay in decompression was common in our series, and in five cases appeared to be related to the use of a postoperative epidural infusion for pain relief. The presence of associated neurological compromise may have also been a significant factor in the delay to diagnosis in two cases.
Radiological evaluation of the metal-bone interface of a porous tantalum monoblock acetabular component
Authors: Macheras G. A. , Papagelopoulos P. J. , Kateros K. , Kostakos A. T. , Baltas D. , Karachalios T. S.
Published: February 2006

Between January 1998 and December 1998, 82 consecutive patients (86 hips) underwent total hip arthroplasty using a trabecular metal monoblock acetabular component. All patients had a clinical and radiological follow-up evaluation at six, 12 and 24 weeks, 12 months, and then annually thereafter. On the initial post-operative radiograph 25 hips had a gap between the outer surface of the component and the acetabular host bed which ranged from 1 to 5 mm. All patients were followed up clinically and radiologically for a mean of 7.3 years (7 to 7.5). The 25 hips with the 1 to 5 mm gaps were studied for component migration at two years using the Einzel-Bild-Roentgen-Analyse (EBRA) digital measurement method. At 24 weeks all the post-operative gaps were filled with bone and no acetabular component had migrated. The radiographic outcome of all 86 components showed no radiolucent lines and no evidence of lysis. No acetabular implant was revised. There were no dislocations or other complications. The bridging of the interface gaps (up to 5 mm) by the trabecular metal monoblock acetabular component indicates the strong osteoconductive, and possibly osteoinductive, properties of trabecular metal.
Peri-prosthetic tuberculous infection of the hip in a patient with no previous history of tuberculosis
Authors: Kaya M. , Nagoya S. , Yamashita T. , Niiro N. , Fujita M.
Published: February 2006

We report a case of peri-prosthetic tuberculous infection nine years after total hip arthroplasty in a patient with no history of tuberculosis before the procedure. Further investigation revealed active pulmonary tuberculosis which was thought to have spread haematogeneously to the arthroplasty. The infection did not respond to standard antituberculous drugs. Removal of the prosthesis and insertion of an antibiotic spacer were required.
Comparison of two types of ulnar component in type-5 Kudo total elbow arthroplasty in patients with rheumatoid arthritis
Authors: Tanaka N. , Sakahashi H. , Ishii S. , Kudo H.
Published: February 2006

The purpose of this study was to assess the long-term results (more than ten years) of two types of cemented ulnar component with type-5 Kudo total elbow arthroplasty in a consecutive series of 56 patients (60 elbows) with rheumatoid arthritis, and to compare the results in elbows above and below a Larsen grade IV.

There was no radiolucency around the humeral component. Patients in whom a metal-backed ulnar component and a porous-coated stem were used had better clinical results and significantly less progression of radiolucent line formation around the ulnar component. They also had a significantly better long-term survival than patients with an all-polyethylene ulnar component. The clinical results of arthroplasty using all-polyethylene ulnar components were inferior, regardless of the degree of joint destruction.

We conclude that the type-5 Kudo total elbow arthroplasty with cementless fixation of the porous-coated humeral component and cemented fixation of a metal-backed ulnar component is acceptable and well-tolerated by rheumatoid patients.
Do clinical presentation and pre-operative quality of life predict satisfaction with care after total hip or knee replacement?
Authors: Baumann C. , Rat A. C. , Osnowycz G. , Mainard D. , Delagoutte J. P. , Cuny C. , Guillemin F.
Published: February 2006

We conducted a multicentre cohort study of 228 patients with osteoarthritis followed up after total hip or knee replacement. Quality of life and patient satisfaction were assessed by self-administered questionnaires. Patient satisfaction was the dependent variable in a multivariate linear regression model. Independent variables included sociodemographic factors, pre- and post-operative clinical characteristics and the pre-operative and post-discharge health-related quality of life.

The mean age of the patients was 69 years (sd 9), and 43.8% were male. Pre- and postoperative clinical characteristics were not associated with satisfaction with health care. Only pre-operative bodily pain (p < 0.01) and pre-operative social functioning (p < 0.05) influenced patient satisfaction with care.

The pre-operative health-related quality of life and patient characteristics have little effect on inpatient satisfaction with care. This suggests that the impact of the care process on satisfaction may be independent of observed and perceived initial patient-related characteristics.
Fatal pulmonary embolism following ankle fracture in a 17-year-old girl
Authors: Chen L. , Soares D.
Published: February 2006

We report a case of fatal pulmonary embolism following a simple ankle fracture in a 17-year-old girl. The diagnosis was confirmed at post-mortem. The risk factors for deep venous thrombosis and pulmonary embolism and their significance in orthopaedic fracture management are discussed.
Should we use a separate knife for the skin?
Authors: Schindler O. S. , Spencer R. F. , Smith M. D.
Published: February 2006

The aim of this study was to re-assess whether the use of a ‘one-knife technique’ can be considered as safe as the alternative practice of using separate skin and inside knives for elective orthopaedic surgery. A total of 609 knife blades from 203 elective orthopaedic operations, with equal numbers of skin, inside and control blades, were cultured using direct and enrichment media. We found 31 skin blades (15.3%), 22 inside blades (10.8%), and 13 control blades (6.4%) gave bacterial growth.

Of the 31 contaminated skin blades only three (9.7%) had growth of the same organism as found on the corresponding inside blade. It is not known whether contamination of deeper layers in the remaining 90% was prevented by changing the knife after the skin incision. The organisms cultured were predominantly coagulase-negative staphylococci and proprionibacterium species; both are known to be the major culprits in peri-prosthetic infection. Our study suggests that the use of separate skin and inside knives should be maintained as good medical practice, since the cost of a single deep infection in human and financial terms can be considerable.
Frequency and timing of clinical venous thromboembolism after major joint surgery
Authors: Bjørnar̊ B. T. , Gudmundsen T. E. , Dahl O. E.
Published: February 2006

Over a 13-year period we studied all patients who underwent major hip and knee surgery and were diagnosed with objectively confirmed symptomatic venous thromboembolism, either deep venous thrombosis or non-fatal pulmonary embolism, within six months after surgery. Low-molecular-weight heparin had been given while the patients were in hospital.

There were 5607 patients. The cumulative incidence of symptomatic venous thromboembolism was 2.7% (150 of 5607), of which 1.1% had developed pulmonary embolism, 1.5% had deep venous thrombosis and 0.6% had both. Patients presented with deep venous thrombosis at a median of 24 days and pulmonary embolism at 17 days after surgery for hip fracture. After total hip replacement, deep venous thrombosis and pulmonary embolism occurred at a median of 21 and 34 days respectively. After total knee replacement, the median time to the presentation of deep venous thrombosis and pulmonary embolism was 20 and 12 days respectively. The cumulative risk of venous thromboembolism lasted for up to three months after hip surgery and for one month after total knee replacement. Venous thromboembolism was diagnosed after discharge from hospital in 70% of patients who developed this complication.

Despite hospital-based thromboprophylaxis, most cases of clinical venous thromboembolism occur after discharge and at different times according to the operation performed.
Five-year prospective clinical and radiological results of a new cannulated cemented polished Tri-Taper femoral stem
Authors: Field R. E. , Singh P. J. , Latif A. M. H. , Cronin M. D. , Matthews D. J.
Published: February 2006

We describe the results at five years of a prospective study of a new tri-tapered polished, cannulated, cemented femoral stem implanted in 51 patients (54 hips) with osteoarthritis. The mean age and body mass index of the patients was 74 years and 27.9, respectively. Using the anterolateral approach, half of the stems were implanted by a consultant orthopaedic surgeon and half by six different registrars. There were three withdrawals from the study because of psychiatric illness, a deep infection and a recurrent dislocation. Five deaths occurred prior to five-year follow-up and one patient withdrew from clinical review.

In the remaining 51 hips the mean pre-operative Oxford hip score was 47 points which decreased to 19 points at five years (45 hips). Of the stems 49 (98%) were implanted within 1° of neutral in the femoral canal. The mean migration of the stem at five years was 1.9 mm and the survivorship for aseptic loosening was 100%. There was no significant difference in outcome between the consultant and registrar groups. At five years, the results were comparable with those of other polished, tapered, cemented stems. Long-term surveillance continues.
Haymaker Gene Expression in Malignant and Normal Gynecologic Tissues
Authors: Borowsky Mark E. , Das Ballabh , Axiotis Constantine A. , Malka Edmond S. , Abulafia Ovadia , Norin Allen J.
Published: February 2006

We previously reported that cell lines established from human carcinomas and leukemias/lymphomas expressed high levels of an intracellular membrane-bound protein, Haymaker, whereas cell lines derived from non-malignant connective tissue cells and lymphoid cells expressed low levels of this gene product. To determine whether these findings reflect neoplastic transformation or, alternatively, tissue specificity, we examined by immunohistochemical and molecular methods the expression of Haymaker in gynecologic organs with and without tumor. A highly specific, affinity-purified rabbit polyclonal antibody against a 25-mer Haymaker peptide was used for immunohistochemical staining and morphometric analysis of 85 tissue specimens. Immunohistochemical studies demonstrate, for the first time, that Haymaker protein is highly expressed in epithelial cells of the endometrium of the normal uterus and to a somewhat lesser extent in the mucosa of the normal vagina and cervix, but is poorly expressed or absent in cells of the connective tissue and smooth muscle strata of these organs ( p < 0.005). Significant differences in Haymaker expression, as assessed by immunohistochemistry, between malignant and normal gynecologic tissues were not observed ( p = 0.27). The expression of Haymaker protein does not appear, therefore, to be a marker of malignant transformation of the epithelium of gynecologic organs but rather distinguishes both normal and malignant epithelial cells from normal connective tissue and smooth muscle cells
Identification of Antibodies against HAI-1 and Integrin α6β4 as Immunohistochemical Markers of Human Villous Cytotrophoblast
Authors: Hallikas Outi K. , Aaltonen Johanna M. , Koskull Harriet von , Lindberg Lars-Axel , Valmu Leena , Kalkkinen Nisse , Wahlström Torsten , Kataoka Hiroaki , Andersson Leif , Lindholm Dan , Schroder Jim
Published: February 2006

Syncytiotrophoblast and invasive extravillous trophoblast arise from a common stem cell, namely villous cytotrophoblast, but have very different characteristics. The study of the differentiation process relies on the availability of suitable markers for these different cell types of developing placenta. In this work, we have produced monoclonal antibodies that are specific to human villous cytotrophoblast. Monoclonal antibody (MAb) MG2 was specific to villous cytotrophoblast across gestation, and recognizes hepatocyte growth factor activator inhibitor type 1. MAb MD10 stained villous cytotrophoblast across gestation and also some endothelial cells, particularly in the second or third trimester. MAb MD10 recognizes human integrin α6β4. As a test for specificity, the novel MAbs were also used for staining of frozen tissue from human colon carcinoma. The results show that the two antibodies can be used as tools to study human villous cytotrophoblasts and also human tumors. The MG2 antibody seems most specific and promising for the study of various aspects of human villous cytotrophoblast.
Unexpected Serum Parathyroid Hormone Profiles in Some Patients with Primary Hyperparathyroidism
Authors: Boudou Philippe , Ibrahim Fidaa , Cormier Catherine , Sarfati Emile , Souberbielle Jean-Claude
Published: February 2006

Background: Third-generation parathyroid hormone (PTH) assays have been reported to measure only intact PTH(1–84), in contrast to second-generation assays, which also detect PTH(7–84) fragments. Higher PTH measurements were observed with third- than with second-generation PTH assays in a few patients with either severe primary hyperparathyroidism or parathyroid carcinoma.

Methods: We analyzed biological data [second- and third-generation PTH assays, 25-hydroxyvitamin D (25-OHD), calcium, and phosphate concentrations] obtained before and after surgery for 2 groups of patients selected from a large series of consecutive patients with primary hyperparathyroidism (PHPT): 7 female patients with surgically and histologically confirmed PHPT (group 1) and a matched group (group 2).

Results: For group 1 but not group 2, PTH concentrations measured by third-generation PTH assays before surgery were higher than those measured by the second-generation assays. Circulating 25-OHD, calcium, and phosphate concentrations were similar in both groups. In addition, PTH values measured with the third-generation PTH assays in group 1 decreased after surgery.

Conclusions: Our results confirm that third-generation PTH assays do not measure only PTH(1–84). The frequency of this unexpected finding of markedly lower PTH concentrations than previously reported was ∼5% in patients with PHPT without malignancy. We do not know whether the presence of this unexpected profile is predictive of malignancy.
Analytical Performance and Diagnostic Accuracy of Immunometric Assays for the Measurement of Circulating Oxidized LDL
Authors: Holvoet Paul , Macy Elizabeth , Landeloos Michele , Jones Dan , Nancy Jenny S , Van de Werf Frans , Tracy Russell P
Published: February 2006

Background: Oxidized LDL (ox-LDL) plays an important role in the pathogenesis of coronary heart disease (CHD). Several tests for circulating ox-LDL have been published. We believe it is critical to carefully evaluate these assays because small differences in performance may have profound effects when results are compared; we therefore compared the analytical and clinical performances of 2 assays: one developed in our laboratory and a commercial assay (Mercodia) that uses the same monoclonal antibody (4E6).

Methods: We determined the variance of ox-LDL in both tests, including its longitudinal stability (n = 225; 3 time points per person) and its diagnostic accuracy, by ROC analysis of 95 consecutive CHD patients and 20 controls.

Results: The between-person variability was 77% for the in-house assay (with the remaining 23% being within-person and analytical variance) and 74% for the commercial assay. For comparison, previously reported values were 66% for high-sensitivity C-reactive protein and 82% for total cholesterol. The areas under the curves for CHD in the 2 assays were identical (0.85). The odds ratios (logistic regression) for CHD among persons with high ox-LDL (≥15 mg/L) compared with persons with low ox-LDL were not different: 4.3 (95% confidence interval, 1.4–12) for the in-house assay and 3.3 (1.1–10) for the commercial assay.

Conclusions: The longitudinal stability of ox-LDL, as assessed by multiple measures in people over time, is similar to that of total cholesterol and high-sensitivity C-reactive protein. Both assays tested similarly distinguish between healthy controls and CHD patients.
Fast In Vivo Microextraction: A New Tool for Clinical Analysis
Authors: Musteata Florin Marcel , Musteata Mihaela L , Pawliszyn Janusz
Published: February 2006

Background: We sought to develop a technique with the potential to partly replace current methods of analysis based on blood draws. To achieve this goal, we developed an in vivo microextraction technique that is faster than conventional methods, interferes minimally with the investigated system, minimizes errors associated with sample preparation, and limits exposure to hazardous biological samples.

Methods: Solid-phase microextraction devices based on hydrophilic polypyrrole and polyethylene glycol coatings were used for direct extraction of drugs from the flowing blood of beagle dogs, over a period of 8 h. The drugs extracted on the probes were subsequently quantified by liquid chromatography coupled to tandem mass spectrometry. Two calibration strategies—external and standard on the fiber—were used to correlate the amount extracted with the in vivo concentration.

Results: Diazepam and its metabolites were successfully monitored over the course of a pharmacokinetic study, repeated 3 times on 3 beagles. The fast microextraction technique was validated by comparison with conventional plasma analysis, and a correlation factor of 0.99 was obtained. In addition to total concentrations, the method was useful for determining free drug concentrations.

Conclusions: The proposed technique has several advantages and is suitable for fast clinical analyses. This approach could be used not only for drugs, but for any other endogenous or exogenous compounds.
Auditory Distraction and Short-Term Memory: Phenomena and Practical Implications
Authors: Banbury Simon P. , Macken William J. , Tremblay Sébastien , Jones Dylan M.
Published: February 2006

Irrelevant sound tends to break through selective attention and impair cognitive performance. This observation has been brought under systematic scrutiny by laboratory studies measuring interference with memory performance during exposure to irrelevant sound. These studies established that the degree of interference depends on the properties of the irrelevant sound as well as those of the cognitive task. The way in which this interference increases or diminishes as characteristics of the sound and of the cognitive task are changed reveals key functional characteristics of auditory distraction. A number of important practical implications that arise from these studies are discussed, including the finding that relatively quiet background sound will have a marked effect on efficiency in performing cognitive tasks.
Effects of Computer Monitor Viewing Angle and Related Factors on Strain, Performance, and Preference Outcomes
Authors: Sommerich Carolyn M. , Joines Sharon M. B. , Psihogios Jennie P.
Published: February 2006

A model of visual and musculoskeletal strain associated with computer monitor placement was developed. The main premise of which is that monitor placement decisions must take into consideration development of both visual and musculoskeletal strains. Certain factors in the model that were thought to affect one or both types of strain, or that were considered important to rule out for effect, were tested in a lab setting. These factors were viewing angle (eye level, midlevel, low level), monitor size (14 in., 19 in.), keyboard familiarity (touch typist, nontouch typist), and task (reading, mousing, typing). Outcomes included indicators of visual and musculoskeletal strain, preference, and performance. Muscle activity was generally greater for the low viewing angle, for the standard monitor (14 in.), and for non-touch typists. Participants preferred the midlevel placement. Task performance was slightly diminished with eye-level placement. Results are interpreted in relation to the model and to several hypotheses that were formed to focus the inquiry. Actual or potential applications of this research include monitor placement decisions in the design or modification of computer workstations
Effects of Hearing Protectors on Auditory Localization in Azimuth and Elevation
Authors: Bolia Robert S. , D'Angelo William R. , Mishler Pamela J. , Morris Linda J.
Published: February 2006

An experiment was conducted to determine the effects of two types of hearing protectors on auditory localization performance. Six listeners localized a 750--ms broadband noise from loudspeakers ranging in azimuth from -180° to +180° and in elevation from -75° to +90°. Independent variables included the type of hearing protector and the elevation of the source. Dependent measures included azimuth error, elevation error, and the percentage of trials resulting in a frontback confusion. Performance on each of the dependent measures was found to be mediated by one or more of the independent variables. Actual or potential applications include the generation of improved design guidelines for hearing protectors and workplace alarms.
Motor Vehicle Crash Involvement and Moving Violations: Convergence of Self-Report and Archival Data
Authors: Arthur Winfred , Tubre Travis , Day Eric Anthony , Sheehan M. Kathleen , Sanchez-Ku Maria L. , Paul Don , Paulus Leigh , Archuleta Kathryn
Published: February 2006

In the crash involvement literature, it is generally assumed that archival and other "objective" criterion data are superior to self-reports of crash involvement. Using 394 participants (mean age = 36.23 years), the present study assessed the convergence of archival and self-report measures of motor vehicle crash involvement and moving violations. We also sought to determine whether predictor/criterion relationships would vary as a function of criterion type (i.e., archival vs. self-report), and if a combination of both criteria would result in better prediction than would either by itself. The degree of agreement between the two criterion sources was low, with participants self-reporting more crashes and tickets than were found in their state records. Different predictor/criterion relationships were also found for the two criterion types; stronger effects were obtained for self-report data. Combining the two criteria did not result in relationships stronger than those obtained for self-reports alone. Our findings suggest that self-report data are not inherently inferior to archival data and, furthermore, that the two sources of data cannot be used interchangeably. Actual or potential applications include choosing the appropriate criterion to use, which, as the finding of this study reveals, may depend on the purpose of the investigation.
Visual Context and the Control of Movements through Video Display
Authors: Ferrel Carole , Orliaguet Jean-Pierre , Leifflen Daniel , Bard Chantal , Fleury Michelle
Published: February 2006

The aim of this experiment was to test the influence of target context on adaptation to scale perturbations introduced by a video display. Participants performed pointing movements without direct vision of their moving hand, although they could see their movements on a video display. Their perceived movements could be reduced, enlarged, or displayed at their actual size. Three target contexts were compared: dark surround, illuminated frame, and familiar object. Movements were executed with or without vision of hand displacement. Results showed that target context enhanced an allocentric coding of the movement, which improved movement execution. However, the effect of target context changed whether or not the displacement of the hand was available. Overall, the results suggest that target context allowed the extraction of dynamic information about movements, which is used to program and control movements. This suggests that target context could be used efficiently to improve spatial accuracy and speed in teleoperation learning. Potential applications include the reduction of difficulties encountered during teleoperation learning through the introduction of visual context.
Minimum and Comfortable Driving Headways: Reality versus Perception
Authors: Taieb-Maimon Meirav , Shinar David
Published: February 2006

A field study was conducted to evaluate drivers' actual headways in car-following situations, their relationship to the drivers' brake reaction times, and their relationship to the drivers' ability to estimate those headways using different metrics. Drivers were asked to maintain "minimum safe distance" and "comfortable, normal distance with no intention to pass" behind the car ahead. The lead car speeds varied from 50 to 100 km/hr. The results showed that under both sets of instructions, drivers adjusted their distance headways in relation to speed, maintaining constant time headways. A significant portion of the drivers maintained time headways that are considered unsafe in relation to drivers' reaction times. There was no significant relationship between the minimal headways maintained by the drivers and their brake reaction times under conditions of maximum attention and preparedness to apply brakes. Accuracy of spoken estimates of headways varied widely among the three measures used to report perceived headway; meters and car lengths yielded much lower estimates (and ones closer to the actual headways) than did seconds. The results have implications for headway perception, driving safety, driver education, and smart cruise-control design.
Effects of Image Scale and System Time Delay on Simulator Sickness within Head-Coupled Virtual Environments
Authors: Draper Mark H. , Viirre Erik S. , Furness Thomas A. , Gawron Valerie J.
Published: February 2006

Novel patterns of visual-vestibular intersensory stimulation often result in symptoms of simulator sickness, raising health and safety concerns regarding virtual environment exposure. Two experiments investigated the effect of conflicting visual-vestibular cues on subjective reports of simulator sickness during and after a 30-min exposure to a head-coupled virtual interface. Virtual image scale factors (0.5, 1.0, 2.0 magnification, generated by varying geometric field of view angle) were investigated in Experiment 1, and additional system time delays (125, 250 ms) were investigated in Experiment 2. Simulator sickness metrics included spoken self-reports during exposure and simulator sickness questionnaires (pre-exposure, immediate postexposure, and 20 min postexposure). Head yaw angular position data were also recorded. Reports of simulator sickness symptoms were significantly greater in the minification (0.5) and magnification (2.0) image scale factor conditions than in the neutral condition (1.0). Simulator sickness did not vary with changes in time delay, however. Furthermore, a comparison across experiments suggests no appreciable increase in simulator sickness with increasing time delays above the nominal value (48 ms). Head angular position data exhibited certain systematic variations across conditions. Actual or potential applications of this research include virtual environment training, simulation, and entertainment systems.
Spatial Representations of Virtual Mazes: The Role of Visual Fidelity and Individual Differences
Authors: Waller David , Knapp David , Hunt Earl
Published: February 2006

Twenty-four people learned three versions of a room-sized maze: a wire-frame desktop virtual environment (VE), a normal surface-rendered desktop VE, and a real-world maze. Differences among the mental representations formed from each environment were measured with pointing and distance estimation tasks in a real-world version of each maze. People were more accurate at pointing after having learned the real and wire-frame VE maze than the surface-rendered VE maze; however, this effect was small compared with the effect of individual differences. Differences in gender, spatial ability, and prior computer experience were significantly related to the ability to acquire spatial information from the desktop VE. There was a high correlation between spatial knowledge when it was measured in the VE and spatial knowledge measured in the real world. Actual or potential applications include the design of effective VE training systems
Eye Activity Correlates of Workload during a Visuospatial Memory Task
Authors: Van Orden Karl F. , Limbert Wendy , Makeig Scott , Jung Tzyy-Ping
Published: February 2006

Changes in six measures of eye activity were assessed as a function of task workload in a target identification memory task. Eleven participants completed four 2hr blocks of a mock anti-air-warfare task, in which they were required to examine and remember target classifications (friend/enemy) for subsequent prosecution (fire upon/allow to pass), while targets moved steadily toward two centrally located ship icons. Target density served as the task workload variable; between one and nine targets were simultaneously present on the display. For each participant, moving estimates of blink frequency and duration, fixation frequency and dwell time, saccadic extent, and mean pupil diameter, integrated over periods of 10 to 20 s, demonstrated systematic changes as a function of target density. Nonlinear regression analyses found blink frequency, fixation frequency, and pupil diameter to be the most predictive variables relating eye activity to target density Participant-specific artificial neural network models, developed through training on two or three sessions and subsequently tested on a different session from the same participant, correlated well with actual target density levels (mean R = 0.66). Results indicate that moving mean estimation and artificial neural network techniques enable information from multiple eye measures to be combined to produce reliable near-real-time indicators of workload in some visuospatial tasks. Potential applications include the monitoring of visual activity of system operators for indications of visual workload and scanning efficiency.
Testing of Rock Climbing Anchors
Authors: Pircher M
Published: February 2006

The testing procedures for small rock anchors for various recreational activities including rock climbing are regulated in the European Standard EN959. This paper reports on the use of this testing method in a recent study on the strength of rock climbing anchors in sandstone with a relatively low compressive strength. Some limitations of this method were identified and modifications were implemented in order to overcome these limitations. The modified testing procedure and some representative test results are summarized.
Adaptiver Gleitschutz für Schienenfahrzeuge (Adaptive Wheelslide Protection System for Railway Vehicles)
Authors: Stützle Thorsten , Viereck Uwe , Enning Manfred , Stribersky Anton , Rulka Wolfgang
Published: February 2006

Dieser Beitrag beschäftigt sich mit der Auslegung und dem Test einer Gleitschutzregelung für Schienenfahrzeuge. Als Grundlage für die Reglerentwicklung werden zunächst einfache Modelle des Schienenfahrzeugs, der Kraftschlussbeanspruchung und des Bremssystems vorgestellt. An Hand einer Analyse des Gesamtmodells kann der Wertebereich eines bestimmten Modellparameters berechnet werden, der bei der Auslegung des linearen, robusten Schlupfreglers berücksichtigt werden muss. Daneben wird die Adaption der Reglerverstärkung an einen leicht zu identifizierenden Fahrzeugparameter (Bremszustandsfaktor) beschrieben. Schließlich werden Versuchsergebnisse von Testfahrten mit einer Regelung im Mikroschlupfbereich vorgestellt und diskutiert.
Outcome of bilateral adrenalectomy in congenital adrenal hyperplasia: one unit’s experience
Authors: Ogilvie Cara Megan , Rumsby Gill , Kurzawinski Tom , Conway Gerard S
Published: February 2006

Objective: The use of bilateral adrenalectomy in the management of congenital adrenal hyperplasia (CAH) is controversial. We set out to review the outcome of 5 cases of CAH who have undergone adrenalectomy in our unit.

Design: A retrospective case note review and subject interview of the experience of adrenalectomy in the setting of a tertiary adult CAH clinic.

Methods: Subjects who had undergone adrenalectomy were reviewed at a routine clinic visit with particular reference to clinical and biochemical outcomes after adrenalectomy.

Results: Two subjects underwent surgery for the sole indication of desire for fertility with successful outcome and without subsequent adrenal crises. Three women suffered from the common clinical management problem of unsuppressible hyperandrogenism and worsening obesity. Whilst the outcome of improved appearance and weight loss was achieved in these subjects, all three experienced significant complications including pigmentation and acute episodes of adrenal insufficiency.

Conclusion: We present a mean follow-up of 4.2 patient years and conclude that this procedure may be suitable for selected women with CAH. Outcomes for those pursuing fertility were positive; however, complications were noted in those women for whom the procedure was performed for symptom control. Accepting that the number of subjects is small, it is clear that more data are required before widely recommending this procedure.
Increased serum osteoprotegerin values in long-lived subjects: different effects of inflammation and bone metabolism
Authors: Mazziotti Gherardo , Amato Giovanni , Sorvillo Francesca , Piscopo Marco , Rizzo Maria Rosaria , Lalli Eleonora , Iride Lorenza , Cioffi Michele , Molinari Anna Maria , Paolisso Giuseppe , Carella Carlo
Published: February 2006

Aim: To evaluate serum osteoprotegerin (OPG) concentrations in relation to age-dependent changes in serum markers of bone metabolism and systemic inflammation.

Methods: Two-hundred and eighty-three healthy subjects were evaluated for plasma estimated crea-tinine clearance (Cr-clearance), C-reactive protein (CRP), bone alkaline phosphatase, C-telopeptides of type-1 collagen (CrossLaps), nuclear factor-kappaB ligand (RANKL) and OPG concentrations.

Results: In adult subjects (82 cases aged between 27 and 64 years) serum OPG concentrations were significantly and independently correlated with RANKL and Cr-clearance (R2: 0.29), but not with CRP and biochemical markers of bone metabolism. In old subjects who were between 65 and 84 years of age (52 cases) serum OPG concentrations were significantly higher as compared with the adult subjects and correlated independently and significantly with serum RANKL, Cr-clearance and CrossLaps values (R2: 0.63). The highest OPG values were found in the long-lived subjects (149 cases with ages between 85 and 110 years) who also showed increased serum CrossLaps and CRP concentrations as compared with the younger subjects. However, in the long-lived subjects serum OPG concentrations were significantly and independently correlated with Cr-clearance and CRP (R2: 0.45) but not with CrossLaps values.

Conclusions: These data would suggest that different factors might be responsible for the age-dependent enhancement of OPG production. Bone metabolism would seem to be the most important factor influencing serum OPG concentrations in old subjects under 85 years of age, whereas in long-lived subjects the circulating values of this cytokine seem to be mainly correlated with serum CRP which could be a marker of inflammation and cardiovascular risk.
Association between an IGF-I gene polymorphism and body fatness: differences between generations
Authors: Voorhoeve Paul G , van Rossum Elisabeth F C , te Velde Saskia J , Koper Jan W , Kemper Han C G , Lamberts Steven W J , de Waal Henriette A Delemarre-van
Published: February 2006

Objective: A polymorphism near the promoter region of the IGF-I gene has been associated with serum IGF-I levels, body height and birth weight. In this study, we investigated whether this polymorphism is associated with body composition in young healthy subjects in two cohorts of different generations.

Design: Observational study with repeated measurements.

Methods: The study group consisted of two comparable young Dutch cohorts with a generational difference of around 20 years. The older cohort consisted of 359 subjects born between 1961 and 1965. Measurements were performed from 13 until 36 years of age. The younger cohort consisted of 258 subjects born between 1981 and 1989. Measurements were performed from 8 until 14 years of age. Height, body mass index (BMI), fat mass, fat-free mass, waist and hip circumference were compared between wild-type carriers and variant type carriers of the IGF-I polymorphism.

Results: In the younger cohort, body weight, BMI, fat mass and waist circumference were significantly higher in female variant carriers of the IGF-I polymorphism. A similar trend was observed in male variant carriers. In contrast, these differences were not observed in the older cohort. Irrespective of genotype, the younger cohort showed a significantly higher total fat mass, body weight and BMI compared with the older cohort.

Conclusions: Because the differences between both genotypes were small, it seems likely that the genetic variability due to this IGF-I polymorphism impacts only slightly on body composition. Importantly, our study suggested that associations between this IGF-I promoter polymorphism and body composition possibly reflect a gene–environmental interaction of this polymorphism and that an environment that promotes obesity leads to a slightly more pronounced fat accumulation in variant carriers of this IGF-I polymorphism.
Aromatase is differentially expressed in peripheral blood leukocytes from children, and adult female and male subjects
Authors: Vottero A , Rochira V , Capelletti M , Viani I , Zirilli L , Neri T M , Carani C , Bernasconi S , Ghizzoni L
Published: February 2006

Objective: Aromatase, the key enzyme involved in estrogen synthesis, is expressed in a variety of cells and tissues including human peripheral blood leukocytes (PBLs). The present study was designed to evaluate PBL aromatase gene expression in male and female subjects of different age groups. In addition, differences in gene expression during the follicular and luteal phase of the menstrual cycle in women, and before and after testosterone administration in men, were estimated.

Design: Aromatase mRNA and protein were measured in PBLs obtained from young (n= 10) and postmenopausal women (n= 10), men (n= 15), and prepubertal children (n= 10). Aromatase mRNA and protein were also measured during the follicular and luteal phases of the menstrual cycle in women, and before and after the intramuscular administration of 250 mg testosterone enanthate in men.

Methods and Results: Aromatase mRNA measured by real-time PCR in PBLs from women during the follicular phase was significantly higher than during the luteal phase of the menstrual cycle (P< 0.05). In men, PBL aromatase mRNA values increased significantly following testosterone administration (P< 0.05). PBL mRNA aromatase levels in women during the follicular phase and men after testosterone administration were significantly higher (one-way ANOVA;P< 0.05) than in any other group. Children, postmenopausal women, and women during the luteal phase showed the lowest aromatase mRNA expression. The results of the immunoblot analysis confirmed the data obtained by real-time PCR. A positive correlation between PBL aromatase mRNA values and plasma estradiol and estrone levels during the follicular phase of the menstrual cycle was observed in the group of adult women. No other correlations were found.

Conclusions: The aromatase gene is differentially expressed in PBLs from women, men, and prepubertal children, indicating a sexual dimorphism in the enzyme expression and an important role of sex steroids in the modulation of aromatase gene expression.