bluuebunny/crossref_metadata_2025 huggingface dataset:
The ‘iris effect’: how two‐dimensional and three‐dimensional ultrasound can help us understand anti‐incontinence procedures
Authors: Dietz H. P. , Wilson P. D.
Published: March 2004

Objective

The objective of this prospective, observational study in patients after tension‐free vaginal tape (TVT™) implantation was to describe the spatial relationship between suburethral sling implants, urethra and bony pelvis with the help of translabial two‐dimensional and three‐dimensional (3D) ultrasound.

Methods

A total of 141 women were examined by translabial ultrasound, supine and after voiding. The TVT sling is highly echogenic and easily identified posterior to the urethra. Tape location was described in the mid‐sagittal plane relative to bladder neck and inferoposterior symphyseal margin, at rest and on Valsalva maneuver. In a subset of 83 women, 3D volume ultrasound was performed.

Results

The cranial tape margin was situated on average 9.3 mm above and 16.5 mm posterior to the symphyseal margin (Valsalva: 3.9 mm below and 9.6 mm behind the symphysis); the average tape movement on Valsalva was 16 (range, 2–34.2) mm. The distance between tape and inferoposterior symphyseal margin narrowed highly significantly from 20.4 ± 4.3 mm at rest to 12.9 ± 3.9 mm on Valsalva (P < 0.001). When a fitted line plot was placed through tape coordinates on an x–y coordinate system, it became evident that tape movement occurs in an arc around the fulcrum of the posterior symphysis pubis. The result is an increasing reduction in the gap between tape and symphysis pubis (termed the ‘iris effect’), implying mechanical compression of the urethra.

Conclusions

The curative effect of the TVT on stress incontinence is likely to be due to mechanical compression of the urethra between implant and symphysis pubis. A large variation in tape location and movement explains its wide margin of clinical safety and efficacy. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Transvaginal sonographic appearance of peritoneal pseudocysts
Authors: Savelli L. , De Iaco P. , Ghi T. , Bovicelli L. , Rosati F. , Cacciatore B.
Published: March 2004

Objective

To describe the sonographic features of peritoneal pseudocysts (PPCs) in order to determine the particular aspects that distinguish them from true ovarian cysts.

Methods

Thirty‐one women with PPCs were investigated using transvaginal sonography immediately before surgery. The diameters of the cysts were measured, and the shape, margins, content, location, presence of septa and echogenic portions were analyzed.

Results

The PPCs were monolateral in 20 (65%) and bilateral in 11 (35%) women. A well‐defined cystic structure was found in only six (19%) women, while in the other 25 (81%) women the PPCs showed blurred, undefined margins and a bizarre morphology, giving them a star‐like tubular or lumpy shape. The ipsilateral ovary was identified in 26 (84%) cases either external to the cyst or entrapped within it like a ‘spider in a web’. Septa were present in 25 (81%) cases and were often mobile, resembling a ‘flapping sail’ when touched by the endovaginal probe.

Conclusion

Despite having a gross morphology resembling that of a true ovarian cyst, PPCs present some characteristic sonographic findings that allow a correct differential diagnosis in the vast majority of cases. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Correlating structure and function: three‐dimensional ultrasound of the urethral sphincter
Authors: Robinson D. , Toozs‐Hobson P. , Cardozo L. , Digesu A.
Published: March 2004

Objective

Three‐dimensional (3D) ultrasound facilitates assessment of the anatomy of the urethral sphincter, a decrease in sphincter volume being associated with stress incontinence. Urethral pressure profilometry (UPP) is used to assess urethral sphincter function although it is not diagnostic of stress incontinence. The aim of this pilot study was to determine whether 3D sphincter volume can be correlated with the area under the UPP curve.

Methods

Primigravid women were recruited antenatally between 32 and 42 weeks' gestation. 3D transvaginal ultrasound scans of the urethra were performed in modified lithotomy position with a comfortably full bladder. Length and cross‐sectional area were measured allowing the sphincter volume to be calculated. UPP measurements were performed with a Gaeltec solid‐state pressure transducer and the area under the curve mapped out and calculated. All scans and measurements were repeated between 3 and 6 months postpartum.

Results

Nineteen women participated in the study. Antenatal and postnatal data were available in all cases. There was a statistically significant correlation between antenatal sphincter volumes and area under the UPP curve although this relationship was lost following delivery.

Conclusions

There appears to be a correlation between structural anatomy and functional anatomy in the antenatal period although following delivery this is lost. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Likelihood ratio for trisomy 21 in fetuses with absent nasal bone at the 11–14‐week scan
Authors: Cicero S. , Rembouskos G. , Vandecruys H. , Hogg M. , Nicolaides K. H.
Published: March 2004

Objective

To update the likelihood ratio for trisomy 21 in fetuses with absent nasal bone at the 11–14‐week scan.

Methods

Ultrasound examination of the fetal profile was carried out and the presence or absence of the nasal bone was noted immediately before karyotyping in 5918 fetuses at 11 to 13+6 weeks. Logistic regression analysis was used to examine the effect of maternal ethnic origin and fetal crown–rump length (CRL) and nuchal translucency (NT) on the incidence of absent nasal bone in the chromosomally normal and trisomy 21 fetuses.

Results

The fetal profile was successfully examined in 5851 (98.9%) cases. In 5223/5851 cases the fetal karyotype was normal and in 628 cases it was abnormal. In the chromosomally normal group the incidence of absent nasal bone was related first to the ethnic origin of the mother, being 2.2% for Caucasians, 9.0% for Afro‐Caribbeans and 5.0% for Asians; second to fetal CRL, being 4.7% for CRL of 45–54 mm, 3.4% for CRL of 55–64 mm, 1.4% for CRL of 65–74 mm and 1% for CRL of 75–84 mm; and third to NT, being 1.6% for NT ≤ 95th centile, 2.7% for NT > 95th centile–3.4 mm, 5.4% for NT 3.5–4.4 mm, 6% for NT 4.5–5.4 mm and 15% for NT ≥ 5.5 mm. In the chromosomally abnormal group there was absent nasal bone in 229/333 (68.8%) cases with trisomy 21 and in 95/295 (32.2%) cases with other chromosomal defects. Logistic regression analysis demonstrated that in the chromosomally normal fetuses significant independent prediction of the likelihood of absent nasal bone was provided by CRL, NT and Afro‐Caribbean ethnic group, and in the trisomy 21 fetuses by CRL and NT. The likelihood ratio for trisomy 21 for absent nasal bone was derived by dividing the likelihood in trisomy 21 by that in normal fetuses.

Conclusion

At the 11–14‐week scan the incidence of absent nasal bone is related to the presence or absence of chromosomal defects, CRL, NT and ethnic origin. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Enlarged adrenal glands as a prenatal marker of congenital adrenal hyperplasia: a report of two cases
Authors: Esser T. , Chaoui R.
Published: March 2004

We report the prenatal findings of congenital adrenal hyperplasia (CAH) in two consecutive fetuses of one family. The first pregnancy was terminated at 23 weeks' gestation due to the presence of a complex heart anomaly. The adrenal glands appeared enlarged on prenatal ultrasound examination and autopsy confirmed CAH. The parents were subsequently examined and were found to be heterozygous for nucleotide 656 of the CYP21B gene. In a subsequent pregnancy, chorionic villus sampling at 11 weeks confirmed CAH in the male fetus. At this gestational age, mild body edema was present and the nuchal translucency measured 2.1 mm. From 14 weeks onwards, enlargement of the adrenal glands was the only sign of CAH. These findings suggest that enlarged adrenal glands may be a prenatal sign for CAH. In fetal medicine, when a pregnancy is terminated due to fetal malformations, autopsy should be performed because it can provide additional information that is helpful in counseling women with regard to subsequent pregnancies. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Sonographic findings in a case of voiding dysfunction secondary to the tension‐free vaginal tape (TVT) procedure
Authors: Yang J.‐M. , Huang W.‐C.
Published: March 2004

The tension‐free vaginal tape (TVT) procedure was introduced as a minimally invasive surgical technique for treating female stress urinary incontinence. This procedure is supposed to be associated with less postoperative voiding dysfunction because the vaginal tape, theoretically, remains tension‐free. Nevertheless, significant voiding dysfunction or complete urinary retention has been reported to complicate 2.8% to 7.6% of TVT procedures. We report a case of voiding dysfunction following a TVT procedure. Two‐dimensional sonography revealed the tape situated beneath the mid‐urethra. The spatial orientation between the vaginal tape and the urethral structure was clearly demonstrated on three‐dimensional scanning. The urethra was indented from the posterior by the vaginal tape, resulting in acute constriction of the hypoechogenic region of the urethra. Urethral dilation was performed using Hegar dilators. Thereafter, the patient's voiding difficulty improved dramatically and the residual urine volume decreased. One week later, repeat sonography showed the hypoechogenic region of the urethra to have a normal configuration with a lesser degree of urethral indentation. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Ultrasound diagnosis of intra‐urethral tension‐free vaginal tape (TVT) position as a cause of postoperative voiding dysfunction and retropubic pain
Authors: Tunn R. , Gauruder‐Burmester A. , Kölle D.
Published: March 2004

Intra‐urethral Prolene® tape erosion is a rare postoperative complication of tension‐free vaginal tape (TVT) plasty. In cases reported in the literature, intra‐urethral tape positioning has been diagnosed by urethroscopy as late as 3–12 months after the procedure. Introital ultrasound using a vaginal sector scanner allows for the non‐invasive assessment of the position of the Prolene tape in relation to the urethra. Postoperative introital ultrasound might shorten the interval between surgery and the time of diagnosis of an intra‐urethrally placed tape and thus significantly shorten the duration of symptoms. We present a patient with urethral pain syndrome and dysuria following TVT plasty. In this case, introital ultrasound was not performed until 8 months after surgery, when it demonstrated intra‐urethral Prolene tape positioning as the cause of the patient's complaints. All symptoms disappeared after surgical removal of the intra‐urethrally placed parts of the tape. The patient is continent, suggesting that the remaining para‐urethral portions of the Prolene tape depicted sonographically ensured adequate stabilization of the mid‐urethra in this case. The case report emphasizes the role of introital ultrasound in assessing Prolene tape position relative to the urethra on sagittal and transverse angulated views in the postoperative diagnostic evaluation of functional disturbances occurring after TVT plasty. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Time domain measurement of blood flow in the human fetal aorta during normal pregnancy
Authors: Thompson O. , Gunnarson G. , Vines K. , Fayyad A. , Wathen N. , Harrington K.
Published: March 2004

Objective

To evaluate blood‐volume flow‐rate measurement in the fetal descending thoracic aorta using a non‐invasive, non‐Doppler, ultrasound technique.

Methods

This was a cross‐sectional, observational study. Volume flow measurements were obtained from the descending thoracic aorta in 59 human fetuses between 20 and 40 weeks' gestation. These were uncomplicated pregnancies that resulted in the live births of appropriately grown infants. The measurements were obtained using a time domain processing technique: color velocity imaging quantification (CVI‐Q).

Results

The blood‐volume flow rate increased consistently from the second trimester until term. The mean values ranged between 100 mL/min at 20 weeks' gestation and approximately 350 mL/min at term. The normalized (weight‐adjusted) volume flow rates decreased with increasing gestation, from a maximum of 626 mL/min/kg at 23 weeks to a minimum of 45.6 mL/min/kg at 37 weeks.

Conclusions

The regular measurement of blood‐volume flow in the descending fetal thoracic aorta is feasible using CVI‐Q. Although there is a considerable learning curve, with adequate training there are potential clinical applications for this non‐Doppler technique. However, limitations exist with the currently available technology for clinical use in fetal vascular studies. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Cesarean section scar evaluation by saline contrast sonohysterography
Authors: Regnard C. , Nosbusch M. , Fellemans C. , Benali N. , van Rysselberghe M. , Barlow P. , Rozenberg S.
Published: March 2004

Objective

To investigate the frequency of images suggesting the existence of a dehiscence at the site of the uterine scar after Cesarean section.

Methods

Thirty‐three women with a past history of Cesarean section who were planning a further pregnancy were involved in the study. Saline contrast sonohysterography (SCSH) was performed a minimum of 3 months following Cesarean section. The thickness of the residual myometrium, the thickness of the myometrium bordering the scar and the depth of the filling defect in the scar (i.e. the ‘niche’, defined as a triangular, anechoic area at the presumed site of incision) were recorded in each case. A ‘dehiscence’ was defined as a niche whose depth was at least 80% of the anterior myometrium.

Results

In 19/33 (57.5%) patients a niche with a depth of 4.2 ± 2.5 (range, 1.2–11.7) mm was identified. In these patients the residual myometrium measured 6.5 ± 2.7 (range, 0–10.9) mm vs. 8.9 ± 2.0 (range, 6.9–13.9) mm in the remaining 14 patients without a niche. Within the 19 niches, two dehiscences were identified.

Conclusion

Niches can be identified by SCSH following a Cesarean section in about 60% of patients. The prevalence of scar dehiscence (in the present series 2/33 or 6%) is much higher than the reported risk of uterine rupture (0.4%). Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Geometrical efficiency, solid angle contribution and gradient for a triaxial system equipped with a fluorescent source and x‐ray tube: an analysis to enhance the Compton scattered photons
Authors: Rao D. V. , Cesareo R. , Brunetti A. , Gigante G. E. , Akatsuka T. , Takeda T. , Itai Y.
Published: March 2004

The total geometrical efficiency, solid angle contribution and gradient were estimated theoretically for a sample placed in a triaxial system equipped with a fluorescent source and x‐ray tube. The contribution of all of the above parameters were assessed at two different secondary target angles with distance. These values are useful for the triaxial system to measure the basic interaction cross‐sections excited by keV photons, to enhance the Compton scattered photons, estimation of monochromacy, solid angle correction and geometrical efficiency. Initially, the secondary target and sample are located at an angle of 45° and detected the scattered radiation from the sample to enhance the Compton scattered photons. By placing the sample at 90° in a triaxial system, the contribution of background is estimated. Comparing the data obtained in the two modes, the Compton photons are enhanced. An analysis of the above parameters and their importance for various potential applications are thoroughly discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Calculation of M x‐ray production cross sections from 1–1500 keV in the atomic region 70 ⩽ Z ⩽ 92
Authors: Ertuǧrul Mehmet , Sade Keziban , Erdoǧan Hasan
Published: March 2004

M x‐ray production cross sections from 1 to 1500 keV were obtained for elements with 70 ⩽ Z ⩽ 92. Obtained values were tabulated and plotted against the atomic number and energy. In the calculation process, published sources were used. The radiative transition rates and photoionization cross sections of the elements were taken from the relativistic Hartree‐Slater model of Scofield (At. Data Nucl. Data Tab. 14, 121 (1974), UCRL‐51376 (1973)), the nonradiative transition rates were taken from the Dirac‐Hartree‐Slater model of Chen et al. (At. Data. Nucl. Data Tab. 24, 14(1979)) and average M shell fluorescence yield values were obtained from Hubbell et al. (J. Phys. Chem. Ref. Data 23, 339 (1994)). Copyright © 2004 John Wiley & Sons, Ltd.
A gas proportional‐scintillation counter for x‐ray spectrometry in the 0.1–3 keV range
Authors: Borges F. I. G. M. , dos Santos J. M. F. , Dias T. H. V. T. , Santos F. P. , Conde C. A. N.
Published: March 2004

Results for the energy resolution of a uniform‐field gas proportional‐scintillation counter are presented for the range 0.1–3 keV. A comparison with results from the literature shows that the detector is most suitable for this energy range. Examples of x‐ray fluorescence pulse‐height distributions from geological and industrial samples are presented. Copyright © 2004 John Wiley & Sons, Ltd.
Analysis of silicates using wavelength‐dispersive x‐ray fluorescence spectrometry for major elements: effects of loss elimination and catch‐weights
Authors: Hettipathirana T. D. , Grey N. A. , Naidu R.
Published: March 2004

Analysis of silicates using wavelength‐dispersive x‐ray fluorescence spectrometry was evaluated for the determination of the 10 most common major elements, Fe, Mn, Ti, P, Ca, K, Si, Al, Mg and Na and also Zr, Sr, S and Cl. The calibration was based on de Jongh alpha coefficients for loss‐eliminated matrix correction, a flux containing Li2B4O7 and LiBO2 and two‐level synthetic standards prepared in SiO2 matrices (except for S and Cl). Sulphur and Cl standards were prepared in Al2O3 matrices because of poor reproducibility of duplicates prepared in an SiO2 matrix. Backgrounds for major elements (high peak‐to‐background ratio) were not measured. Trace elements (low peak‐to‐background ratio) were not determined and their matrix effects were not considered. The method was validated for the 10 most common major elements using 23 Certified Reference Materials covering a wide range of concentrations. The absolute error was <±0.2% for most determinations and within experimental error. Sulphur and Cl in high silicate concentrations were not accurately quantifiable owing to variable retention during the vigorous fusion of the SiO2 matrix. For samples with high loss‐on‐fusion (LOF), catch‐weights caused a significant and systematic error for the major element with highest concentration. The presence of undetermined trace elements showed no significant effect except slightly overestimated LOF. For an accurate analysis, it is therefore necessary that nominal weights be used when LOF is high and all major elements are determined. The method is suitable for the ‘as received’ analysis of a wide variety of silicates for major elements. Copyright © 2004 John Wiley & Sons, Ltd.
Nanodroplets: a new method for dried spot preparation and analysis
Authors: Miller Thomasin C. , Havrilla George J.
Published: March 2004

The dried spot technique is an effective method for elemental analysis. However, the current technology, using microliter volume spots, suffers from lack of repeatability and long sample preparation times. In this study, a new nanoliter dried spot sample preparation method was developed and tested. Drying time, drying pattern and detection limits were compared between spots formed from microliter‐ and nanoliter‐sized droplets. This new nanoliter deposition method reproducibly produced uniform spots. The sample throughput was increased significantly with nanoliter droplet drying times ranging from only seconds to minutes. The minimum detectable concentrations for the nanoliter spots were in the ppb range with the ability to detect picogram‐level masses. This new sample preparation method has the potential for use in situations where sample availability is limited. Furthermore, nanoliter dried spots are smaller in diameter than the exciting x‐ray beam in micro‐XRF and conventional XRF instrumentation. This allows faster drying nanoliter droplet microarrays to be used in situations where microliter droplets are primarily used. Published in 2004 John Wiley & Sons, Ltd.
The capabilities of an electrically cooled energy‐dispersive x‐ray detector for quantitative x‐ray fluorescence analysis
Authors: Kump P. , Nečemer M. , Drinovec J.
Published: March 2004

The capabilities of the Si PIN diode x‐ray detector were determined and compared with those of a standard Si(Li) detector. The x‐ray fluorescence (XRF) analysis systems assembled with these two detectors included annular radioisotope excitation sources of Cd‐109 and Fe‐55. The systems were calibrated for sensitivity and quantification was performed with fundamental parameters software. Based on the analysis of the standard reference material NIST 2710 (Montana soil), the elemental sensitivities and the limits of detection of both systems were obtained. The elemental sensitivities of the Si PIN detector for fluorescence x‐rays in the energy range up to 10 keV were comparable to those of the Si(Li) detector. At higher fluorescence x‐ray energies the sensitivity of the Si PIN detector gradually decreased and was smaller by a factor of ∼4 at 20 keV. The reason was mainly the small thickness of the sensitive volume of the Si PIN diode (0.2 mm) and therefore the smaller relative efficiency of this detector. The assessed limits of detection (LODs) were comparable for the two detectors, which was mainly due to the lower spectral background of the Si PIN detector in excitation with the Cd‐109 source as a result of its smaller sensitive thickness. The accuracy of elemental determinations for the two detectors was comparable and within the limits of the assessed uncertainties, which were calculated considering all the steps of the analysis, i.e. spectrum measurement and analysis, sensitivity calibration and quantification. Copyright © 2004 John Wiley & Sons, Ltd.
Elemental analysis by high‐energy electron excitation
Authors: Mainardi Raul T. , Chesta Miguel A. , Caffaro Mariana
Published: March 2004

The possibility of using high‐energy β‐particles (102–103 keV) to induce the emission of characteristic x‐rays from pure chemical elements, with important improvements with respect to conventional excitation methods, has been recently reviewed. An excitation procedure named BIXE (β‐induced x‐ray emission) is used for implementing a spectrometric technique along the lines developed for EPMA (electron probe microanalysis). We have found that by using BIXE it is possible to determine binary sample compositions of elements present at concentrations higher than 1%, by comparisons with reference samples to obtain calibration curves. Experience with EPMA shows that when ternary and higher order samples are analyzed, the use of reference samples is not enough and it is necessary to perform theoretical corrections to the relationship between the line intensity and the corresponding concentrations, as a suitable complement to the analytical procedure. Semi‐quantitative results are thus obtained with corrections applied through the ZAF method usually used in EPMA. In this work we concentrated in finding whether calibration curves as used in EPMA (where the electron beam is monochromatic) can be used in BIXE, where the electron beam is polychromatic (the β spectrum).

We expect that BIXE can be developed as a spectrometric technique whose main advantages are that it is a low‐cost technique suitable for in situ studies and that the experimental arrangement and data acquisition and its evaluation are comparatively simple. Copyright © 2004 John Wiley & Sons, Ltd.
Wavelength‐dispersive x‐ray fluorescence measurements on organic matrices: application to milk‐based products
Authors: Perring Loïc , Andrey Daniel
Published: March 2004

A simple and fast method for the determination of a series of analytes (sodium, magnesium, phosphorus, sulfur, chlorine, potassium, calcium, iron, zinc) in milk‐based products by wavelength‐dispersive x‐ray fluorescence spectrometry was developed and validated. Reference values were obtained by inductively coupled plasma optical emission spectroscopy and by potentiometry for chloride. The investigated samples were commercial products obtained from various parts of the world. Pellets of 4 g were prepared under 2 t pressure. For each sample, three pellets were prepared and analysed. Limits of quantification and repeatabilities were evaluated for the described analytes. Calibrations were established with 29 samples and validation of the method was made using a second set of 29 samples. An evaluation of this alternative method was done by comparison with data from the reference methods, using robust statistics. Copyright © 2004 John Wiley & Sons, Ltd.
Corrections to the conventional approach to Si(Li) detector efficiency
Authors: O'Meara Joanne M. , Campbell John L.
Published: March 2004

The contribution to full‐energy peak intensity from coherent or Compton scatter interactions followed by photoelectric absorption was calculated by the Monte Carlo method and found to be significant for photon energies above 30 keV. A multiple‐event term was therefore incorporated in the conventional physical model of detector efficiency. Also, a widely used approximation in the model was made rigorous, thereby removing a source of error. Efficiency measurements with and without an external collimator suggested the need for a further additional term, this one describing incomplete collimation by the internal aperture structure. Measured efficiency curves were least‐squares fitted using the conventional model with and without these corrections and new terms. The deduced detector thickness agreed with the manufacturer's value only when the new terms were used. Copyright © 2004 John Wiley & Sons, Ltd.
Clinical and attentional effects of acute nicotine treatment in Tourette’s syndrome
Authors: Howson Anne L. , Batth Sue , Ilivitsky Vadim , Boisjoli Armand , Jaworski Martine , Mahoney Colleen , Knott Verner J.
Published: March 2004

Evidence from pre-clinical infrahuman investigations, open-label clinical trials, and a single controlled trial found acute nicotine treatment potentiated up to 4 weeks neuroleptic-induced reductions of dyskinetic symptoms characterizing Tourette’s syndrome (TS). Given the attentional disturbances associated with this syndrome, and the improvements in attentional processes reported with nicotine, this randomized, double-blind, placebo-controlled trial examined the acute (4 h) and sustained (2 weeks) effects of a single dose of transdermal nicotine on clinical (i.e., tics), attentional (continuous performance task, event-related potentials, patient and parental reports) and behavioral symptoms in 23 children and adolescents with TS receiving neuroleptic treatment. In the 14 evaluable patients with complete primary efficacy data, nicotine (compared to placebo) failed to alter symptoms at 4 h but counteracted ERP-P300 signs of diminished attention seen 2 weeks following placebo treatment. Secondary efficacy measures, including patient self-reports and parental ratings, found nicotine to reduce complex tics and improve behaviors related to inattention. Additional work with intermittent dosing schedules is required to characterize optimal clinical and cognitive effects with nicotine treatment.
Volatility-based Effects on Shareholder Value: Alliance Activity in the Computing Industry
Authors: Arend Richard J.
Published: March 2004

We use an event-study analysis to understand how alliance activity affects firm risk. The risk measure is the implied volatility of a firm’s stock price and the events are alliance announcements to the market. We build on the previous event-studies in the alliance literature that focus on the change in shareholder value by taking the first step in delineating what part of that value arises from the changes in the firm’s risk. The analysis reveals that a number of factors within a firm’s control can be used to manipulate risk exposure in an alliance, including the similarity of the firm’s and the alliance’s core activities, the governance form of the alliance, and the function of the alliance.
A Little Creativity Goes a Long Way: An Examination of Teams’ Engagement in Creative Processes
Authors: Gilson Lucy L. , Shalley Christina E.
Published: March 2004

Using surveys and interview data this research examines teams’ engagement in creative processes. Results of cluster analysis indicated that the more creative teams were those that perceived that their tasks required high levels of creativity, were working on jobs with high task interdependence, were high on shared goals, valued participative problem-solving, and had a climate supportive of creativity. In addition, members of the more creative teams spent more time socializing with each other and had moderate amounts of organizational tenure. Implications for management are discussed.
Examination of Structured Interview Ratings Across Time: The Effects of Applicant Race, Rater Race, and Panel Composition
Authors: McFarland Lynn A. , Ryan Ann Marie , Sacco Joshua M. , Kriska S. David
Published: March 2004

This study examined the relationship between race and interview ratings in a structured selection panel interview. Data from 1,334 police officer applicants who were interviewed by three-person panels were examined to explore how applicant race, rater race, and panel racial composition related to interview ratings and change from initial to final ratings. Results revealed the largest effect was for panel racial composition, such that predominately White panels provided significantly more favorable ratings to applicants of all races compared to panels composed of predominately Black raters. However, a significant three-way interaction between rater race, applicant race, and panel composition was also found. Specifically, Black raters evaluated Black applicants more favorably than White applicants only when they were on a predominately Black panel. These results may help explain past inconsistencies in the literature regarding the effects of rater race and applicant race on ratings.
The Effects of Top Management Team Pay and Firm Internationalization on MNC Performance
Authors: Carpenter Mason A. , Sanders Wm. Gerard
Published: March 2004

We examine relationships among top management team (TMT) compensation, a firm’s degree of internationalization (DOI), and its subsequent levels of market and accounting performance. Consistent with our contingency view of information-processing theory, we find that non-CEO total pay and the use of long-term incentive pay are positively associated with subsequent performance, whereas the CEO–TMT total pay gap has negative effects on firm performance. CEO pay has no relationship with performance and TMT pay effects are much stronger in MNCs with high DOI.
The Role of Trust and Contractual Safeguards on Cooperation in Non-equity Alliances
Authors: Lui Steven S. , Ngo Hang-Yue
Published: March 2004

Because partners may behave opportunistically in alliances, contractual safeguards or trust between partners are necessary for successful outcomes. However, it remains controversial whether safeguards and trust substitute or complement each other. Drawing on transaction cost theory, this study conceptualizes both contractual safeguards and trust as important control mechanisms in non-equity alliances, and develops a model that relates contractual safeguards and trust to cooperative outcomes. We test our hypotheses with data collected from 233 architect–contractor partnerships in Hong Kong. The results show that the relationship between contractual safeguards and cooperative outcomes depends on both the level and type of trust.
Can a Previous Alliance Between an Acquirer and a Target Affect Acquisition Performance?
Authors: Porrini Patrizia
Published: March 2004

Throughout the 1990s, organizations have been combining resources through acquisitions and alliances in record numbers. An acquirer’s previous alliance with a target may give an acquirer target-specific information and experience that may be an advantage-producing resource in selection, valuation and integration of the target. This study investigates whether a previous alliance between an acquirer and a target affects post-acquisition performance and finds that a previous alliance between an acquirer and a target correlates positively with acquisition performance. Acquirers’ previous R&D, technology transfer, manufacturing and marketing alliances with targets benefit acquisition performance more than their previous licensing alliances with targets. Furthermore, target-specific learning effects are strongest and most beneficial to acquisition performance in acquirers’ previous technology transfer and manufacturing alliances with targets.
Antiresorptive therapy conserves some periarticular bone and ligament mechanical properties after anterior cruciate ligament disruption in the rabbit knee
Authors: Doschak M. R. , Wohl G. R. , Hanley D. A. , Bray R. C. , Zernicke R. F.
Published: March 2004

The purpose of this study was to assess, in an osteoarthritic (OA) model, whether bisphosphonate (BP) antiresorptive therapy altered periarticular bone and bone–ligament biomechanics and OA progression. We surgically transected the anterior cruciate ligament (ACLX) in two groups of rabbits; the first group was dosed with BP (risedronate, 0.01 mg/kg s.c. daily for 6 wk), the second group remained untreated, and a third group of normal (unoperated) control rabbits was also evaluated. We measured distal femoral bone mineral density (BMD, Dual Energy X‐ray Absorptiometry [DEXA]), medial collateral ligament (MCL) laxity, and bone mechanical function (bone cores mechanically tested in compression). These measures were related to cartilage/joint gross morphology, histology, and measures of vascular volume (gelatin–dye perfusion) for evidence of inflammatory angiogenesis and early OA. BMD by DEXA in 6 wk ACLX animals was 18% less than normal controls (p < 0.05). In contrast, BP dosing conserved periarticular BMD; risedronate‐treated rabbits had distal femoral BMD only 5% less and not significantly different than normal controls. When the same bone cores were compressed to failure, both ACLX and BP‐dosed animals were significantly weaker than normal controls (p < 0.05). However, the bone energy to failure and elastic modulus of BP‐dosed animals was conserved and not significantly different from normal controls 6 wk after ACLX. Blocking bone resorption with BP also resulted in a significantly improved bone–ligament structural complex. MCL‐complex laxity was significantly less in BP‐dosed animals (1.2 times that of normal controls) compared to untreated ACLX animals (1.7 times that of normal controls; p < 0.05). Blocking bone resorption with risedronate did not suppress osteophytosis and inflammatory angiogenesis, which were significantly increased in the periarticular bone of both untreated and BP treated ACLX animals. Thus, administering BP immediately after ACL loss conserved some periarticular bone and MCL‐complex properties in an early OA model. © 2004 Published by Elsevier Ltd. on behalf of Orthopaedic Research Society.
Tendon injury response: Assessment of biomechanical properties, tissue morphology and viability following flexor digitorum profundus tendon transection
Authors: Silva Matthew J. , Ritty Timothy M. , Ditsios Konstantinos , Burns Meghan E. , Boyer Martin I. , Gelberman Richard H.
Published: March 2004

Insertion site injuries of the flexor digitorum profundus (FDP) tendon often present for delayed treatment. Apart from gross observations made at the time of surgery, the changes that occur in the flexor tendon stump during the interval from injury to repair are unknown. These changes may include tendon softening and loss of viability, which may contribute to the poor outcomes observed clinically and experimentally. Thirty‐eight FDP tendons from 23 adult dogs were transected sharply from their insertions on the distal phalanges and were not repaired. Dogs were allowed full weight bearing and were euthanized 7 or 21 days after injury. Biomechanical testing indicated that the resistance of injured tendons to pullout of a Kessler‐type suture was not different from control tendons at 7 days and was increased at 21 days by 25% (p < 0.05). Morphologically, at 7 and 21 days the cut surface had a smooth appearance and the end of the injured tendon was increased in thickness by 30% and 50%, respectively (p < 0.05). Histologically, we observed increased cellularity and dramatic fibroblast proliferation within the injured tendon stump; there was no evidence of decreased cell viability. We conclude that during the interval from 0 to 21 days after FDP insertion‐site injury, tendons cells are viable, proliferative and synthesizing new matrix. This leads to increased tendon size and enhanced resistance to suture pullout. These findings offer a scientific rationale supporting the clinical practice of surgical re‐attachment within the first 3 weeks after injury. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Hsp90 isoforms: functions, expression and clinical importance
Authors: Subbarao Sreedhar Amere , Kalmár Éva , Csermely Péter , Shen Yu-Fei
Published: March 2004

The 90 kDa heat shock protein, Hsp90, is a main functional component of an important cytoplasmic chaperone complex, and it is involved in various cellular processes, such as cell proliferation, differentiation and apoptosis. Identification of Hsp90 as a molecular target of various anticancer drugs highlighted its importance from the clinical point of view. Here we summarize the current knowledge on various Hsp90 isoforms regarding their genomic location, molecular evolution, functional differences, differential induction after various environmental stresses and in pathological conditions as well as the growing importance of discriminating between Hsp90 isoforms in clinical practice.
Susceptibility to transglutaminase of gliadin peptides predicted by a mass spectrometry‐based assay
Authors: Mamone Gianfranco , Ferranti Pasquale , Melck Dominique , Tafuro Filomena , Longobardo Luigi , Chianese Lina , Addeo Francesco
Published: March 2004

A peptidomics approach was developed to identify transglutaminase‐susceptible Q residues within a pepsin–trypsin gliadin digest. Based on tagging with a monodansylcadaverine fluorescent probe, six α/β‐, γ‐gliadin, and low molecular weight glutenin peptides were identified by nanospray tandem mass spectrometry. In functioning as an acyl acceptor, tissue transglutaminase was able to form complexes with the glutamine‐rich gliadin peptides, whereas by lowering pH, the peptides were deamidated by transglutaminase at the same Q residues, which were previously transamidated. The main common feature shared by the peptides was the consensus sequence Q‐X‐P. Our findings offer relevant information for the understanding of how dietary peptides interact with the host organism in celiac disease.
Coronalon: a powerful tool in plant stress physiology
Authors: Schüler Göde , Mithöfer Axel , Baldwin Ian T , Berger Susanne , Ebel Jürgen , Santos Jonathan G , Herrmann Gabriele , Hölscher Dirk , Kramell Robert , Kutchan Toni M , Maucher Helmut , Schneider Bernd , Stenzel Irene , Wasternack Claus , Boland Wilhelm
Published: March 2004

Coronalon, a synthetic 6‐ethyl indanoyl isoleucine conjugate, has been designed as a highly active mimic of octadecanoid phytohormones that are involved in insect and disease resistance. The spectrum of biological activities that is affected by coronalon was investigated in nine different plant systems specifically responding to jasmonates and/or 12‐oxo‐phytodienoic acid. In all bioassays analyzed, coronalon demonstrated a general strong activity at low micromolar concentrations. The results obtained showed the induction of (i) defense‐related secondary metabolite accumulation in both cell cultures and plant tissues, (ii) specific abiotic and biotic stress‐related gene expression, and (iii) root growth retardation. The general activity of coronalon in the induction of plant stress responses together with its simple and efficient synthesis suggests that this compound might serve as a valuable tool in the examination of various aspects in plant stress physiology. Moreover, coronalon might become employed in agriculture to elicit plant resistance against various aggressors.
Identification of macrophage/microglia activation factor (MAF) associated with late endosomes/lysosomes in microglial cells
Authors: Bräuer Anja U , Nitsch Robert , Savaskan Nicolai E
Published: March 2004

Damage to the central nervous system triggers rapid activation and specific migration of glial cells towards the lesion site. There, glial cells contribute heavily to secondary neuronal changes that take place after lesion. In an attempt to identify the molecular cues of glial activation following brain trauma we performed differential display reverse transcription‐polymerase chain reaction screenings from lesioned and control hippocampus. Here we report on the identification of the macrophage/microglia activation factor (MAF), a new membrane protein with seven putative transmembrane domains. Expression analysis revealed that MAF is predominantly expressed in microglial cells in the brain, and is upregulated following brain lesion. Overexpression of MAF in non‐glial cells shows an intracellular codistribution with the lysosomal marker endosome/lysosome‐associated membrane protein‐1 (lamp‐1). Furthermore, MAF‐transfected cells show that MAF is primarily associated with late endosomes/lysosomes, and that this association can be disrupted by activation of protein kinase C‐dependent pathways. In conclusion, these results imply that MAF is involved in the dynamics of lysosomal membranes associated with microglial activation following brain lesion.
Fluorescent analogues of plasma membrane sphingolipids are sorted to different intracellular compartments in astrocytes
Authors: Tomás Mónica , Durán Juan M , Lázaro-Diéguez Francisco , Babià Teresa , Renau-Piqueras Jaime , Egea Gustavo
Published: March 2004

Sphingolipids are basic constituents of cellular membranes and are essential for numerous functions such as intracellular signalling. They are transported along the exocytic and endocytic pathways in eukaryotic cells. After endocytosis, fluorescent‐labelled sphingolipids are sorted to distinct intracellular organelles prior to recycling (via early/recycling endosomes) or degradation (late endosomes/lysosomes). Here we examine, in primary cultures of rat astrocytes, the internalisation routes followed by C6‐NBD‐glucosylceramide (NBD‐GlcCer) and C6‐NBD‐sphingomyelin (NBD‐SM) and the effects of ethanol on their endocytic trafficking. Endocytosed plasma membrane NBD‐GlcCer and NBD‐SM are diverted to the Golgi apparatus and lysosomes, respectively. These different internalisation pathways are maintained regardless of the differentiation stage of astrocytes. Chronic ethanol exposure did not alter this endocytic sorting, but delayed the internalisation of both NBD‐sphingolipids. Moreover, ethanol also stimulated the in situ metabolism of NBD‐ceramide to NBD‐GlcCer and NBD‐SM. We conclude that in rat astrocytes internalised plasma membrane NBD‐sphingolipids are sorted to different subcellular compartments. The exposure to chronic ethanol perturbed the lipid endocytic process and stimulated the de novo synthesis of NBD‐sphingolipids, shifting the balance of sphingolipid metabolism in favour of the sphingomyelin pathway.
Prostaglandins are powerful inducers of NGF and BDNF production in mouse astrocyte cultures
Authors: Toyomoto Misao , Ohta Mitsuhiro , Okumura Kohji , Yano Hiroe , Matsumoto Kaori , Inoue Seiji , Hayashi Kyozo , Ikeda Kiyoshi
Published: March 2004

We found that prostaglandin (PG) D2 and PGE2, which are major PGs in the brain of mammals, powerfully induced the secretion of nerve growth factor (NGF) from cultured mouse astrocytes; PGE2 or PGD2 induced an approximately 12‐ or 19‐fold increase in NGF secretion after a 24‐h incubation, respectively. Moreover, it was found that the sequential metabolites of PGD2, PGJ2, Δ12‐PGJ2, and 15‐deoxy‐Δ12,14‐PGJ2, induced the NGF secretion to the culture medium strikingly (60–98‐fold of the control after a 24‐h incubation). NGF secretion induced by the J2 series of PGs was accompanied by the increased expression of NGF mRNA. These PGs also stimulated the secretion/synthesis of brain‐derived neurotrophic factor (BDNF). Our findings suggest that PGs play a neuroprotective role by inducing NGF and BDNF production in the central nervous system.
An alternate conformation of the hyperthermostable HU protein from Thermotoga maritima has unexpectedly high flexibility
Authors: Durney Michael A , Wechselberger Rainer W , Kalodimos Charalampos G , Kaptein Robert , Vorgias Constantinos E , Boelens Rolf
Published: March 2004

The homodimeric HU protein from the hyperthermophile Thermotoga maritima (HUTmar) is a model system which can yield insights into the molecular determinants of thermostability in proteins. Unusually for a thermostable protein, HUTmar exists in a structurally heterogeneous state as evidenced by the assignment of two distinct and approximately equally populated forms in solution. Relaxation measurements combined with chemical shift, hydrogen exchange, and nuclear Overhauser enhancement data confirm the main structural features of both forms. In addition, these data support a two‐state model for HUTmar in which the major form closely resembles the X‐ray structure while the very flexible minor form is less structured. HUTmar may therefore be a new example of the small class of hyperthermostable proteins with unexpected flexibility.
Ecology – the science of agriculture in the 21st century
Authors: WEINER J.
Published: March 2004

Most current biological problems in agriculture occur at the higher levels of organization: populations, communities and ecosystems. These are the levels addressed by the science of ecology rather than other biological sciences. Therefore ecology will by necessity become the central science of agriculture. Agricultural production will be seen as a form of applied ecology or ecological engineering. This change in perspective has major implications for agricultural research. It brings the discussion of the assumptions of a research programme into the open and forces researchers to prioritize among potentially conflicting objectives. It sees agricultural strategies in terms of trade-offs, rather than improvements, and it suggests that agricultural research needs to be more bold and ambitious if it is to solve the most important problems facing us in the new century.