bluuebunny/crossref_metadata_2025 huggingface dataset:
Time Sequence of Sensory Changes after Upper Extremity Block
Authors: Paqueron Xavier , Gentili Marc E. , Willer Jean Claude , Coriat Pierre , Riou Bruno
Published: June 2004

Background

Sensory assessment to estimate spread and effectiveness of a peripheral nerve block is difficult because no clinical test is specific for small sensory fibers. Occurrence of a swelling illusion (SI) during a peripheral nerve block corresponds to the impairment of small sensory fibers. The authors investigated the usefulness of SI in predicting successful peripheral nerve block by assessing the temporospatial correlation between progression of sensory impairment in cutaneous distributions anesthetized and localization of SI during peripheral nerve block installation.

Methods

Interscalene, infracoracoid, or sciatic nerve blocks were performed using a nerve stimulator and 1.5% mepivacaine in 53 patients, with a total of 201 nerves to be anesthetized. Pinprick, cold, warm, touch, and proprioception were assessed every 3 min, while patients were asked to describe their perception of size and shape of their anesthetized limb and localization of these illusions. Data are presented as mean +/- SD and percentage (95% confidence interval).

Results

Failure occurred in 12 cutaneous distributions out of a total of 201 theoretically blocked nerves. SI appeared earlier than warmth impairment (4.3 +/- 2.7 vs. 6.2 +/- 2.0 min; P < 0.05), always corresponding to successfully anesthetized cutaneous distributions, with the exception of 1 patient, who developed SI in 2 cutaneous distributions while sensory testing indicated failure in 1 distribution. SI successfully predicted the blockade of a cutaneous distribution with a sensitivity of 1.00 (0.98-1.00), a specificity of 0.92 (0.65-0.99), and an accuracy of 0.99 (0.97-1.00).

Conclusions

Swelling illusion may provide an early assessment of the success of a peripheral nerve block in unsedated patients.
Endoscopic Management of Limited Attic Cholesteatoma
Authors: Tarabichi Muaaz
Published: June 2004

Objectives: Microscopic postauricular tympanomastoidectomy provides a limited exposure to the attic, especially anteriorly. In contrast, the endoscope offers wide transcanal access to the attic, allowing for complete removal of limited attic disease, possibly without interrupting the ossicular chain. This report evaluates 8 years of experience with transcanal endoscopic management of limited attic cholesteatoma.

Study Design: Case series.

Methods: Seventy‐three ears with limited attic cholesteatoma underwent endoscopic transcanal tympanotomy and extended atticotomy to access and completely remove the sac. Disease was dissected off the tegmen, the medial and lateral attic walls, and the ossicles. Appropriate ossicular reconstruction was performed. The defect was reconstructed with a composite tragal graft.

Results: A transcanal endoscopic approach was adequate for removal of disease in all cases. There were no iatrogenic facial nerve injuries. Bone thresholds were stable. Disease was dissected off the head of the malleus and the body of incus with preservation of both in 24 ears. Mean follow‐up was 43 months. Five ears required revision for recurrent disease, and eight were revised for failed ossicular reconstruction or persistent perforation. Moderate to severe retraction in other areas of the tympanic membrane was evident in 28 cases; none of these required further intervention.

Conclusion: An endoscopic technique allows transca‐nal, minimally invasive, eradication of limited attic cholesteatoma. Preservation of the ossicles coupled with complete removal of disease is more likely with the endoscope.
Microsurgical Free Flap Reconstruction Outcomes in Head and Neck Cancer Patients after Surgical Extirpation and Intraoperative Brachytherapy
Authors: Ross Douglas A. , Hundal Jagdeep S. , Son Yung H. , Ariyan Stephan , Shin Joseph , Lowlicht Roger , Sasaki Clarence T.
Published: June 2004

Objectives: The management of recurrent or persistent head and neck cancer poses a challenging problem. Salvage surgery for these individuals consists of ablative surgery, interstitial brachytherapy, and microsurgical free flap reconstruction. This study reviews complications after such reconstruction.

Methods: We reviewed 139 consecutive head and neck cancer patients undergoing free flap reconstruction from January 1994 to May 2002. These included 66 patients with recurrent head and neck cancer undergoing intraoperative brachytherapy (IOBT) and free flap reconstruction and 73 undergoing free flap reconstructions only. A total of 142 reconstructions were performed, with three patients in IOBT group receiving two free flap reconstructions per patient, giving us a total of 69 reconstructions in the IOBT group versus 73 in the non‐IOBT group. Nine patients were excluded from the IOBT group because of nonsynchronous use of brachytherapy and reconstruction, and 10 patients were excluded from the other group because they had prior radiotherapy or surgical treatment, leaving us with a total of 123 reconstructions, 60 in the IOBT group and 63 in the non‐IOBT group. The IOBT group patients received 125iodine Vicryl seed implants, 103palladium seed implants, or both, to deliver an average dose of 79.3 ± 31.8 Gy (mean ± 1SD) to the surgical bed.

Results: All patients were followed for evidence of local wound complications. The IOBT group showed multiple complications in 23 (38.33%) of 60 reconstructions, the most common being wound dehiscence in 11. This, when compared with the non‐IOBT group complications (15.87%), was found to be statistically significant (χ2 test, P < .01).

Conclusion: IOBT increases the rate of complications in patients undergoing microvascular free tissue transfer. This, however, should not deter or alter the aggressiveness of cancer therapy used for managing recurrent head and neck cancer.
Effectiveness of Intratympanic Dexamethasone Injection in Sudden‐Deafness Patients as Salvage Treatment
Authors: Guan‐Min Ho , Hung‐Ching Lin , Min‐Tsan Shu , Cheng‐Chien Yang , Hsun‐Tien Tsai
Published: June 2004

Objective: To study the effectiveness of intratym‐panic dexamethasone (IT‐DEX) in patients with severe or profound sudden sensorineural hearing loss (SSNHL) after treatment failure with conventional therapy.

Study Design: Randomized, controlled study.

Methods: Patients who met the criteria for SSNHL, with a severity of severe to profound, underwent 10 days of standard treatment with oral steroid and other facilitating agents. Patients showing poor response to standard treatment were assigned randomly to a control group or to a group receiving IT‐DEX. IT‐DEX injections were performed once a week for 3 consecutive weeks. Pure‐tone audiometry was obtained before each injection. Minimum follow‐up time was 1 month. Successful treatment was defined as a hearing improvement of greater than 30 dB.

Results: Thirty‐nine patients meeting the inclusion criteria were studied. After treatment with oral steroid, 10 of 39 (26%) patients demonstrated hearing improvement, whereas the remaining 29 (74%) patients showed a hearing improvement of less than 30 dB. For those without hearing improvement, 15 received IT‐DEX, and 14 received further standard treatment (except oral steroid and carbogen inhalation). Hearing improved in 8 of 15 (53.3%) compared with 1 of 14 (7.1%), with an average decrease in threshold of 28.4 dB and 13.2 dB for the IT‐DEX group and the control group, respectively (P < .05). Prognostic factors such as age, treatment delay time, and sex did not significantly affect the response to therapy.

Conclusions: IT‐DEX injection effectively improves hearing in patients with severe or profound SSNHL after treatment failure with standard therapy and is not associated with major side effects. It is therefore a reasonable alternative as salvage treatment.
Characterization of the Vestibulo‐Ocular Reflex Evoked by High‐Velocity Movements
Authors: Roy François D. , Tomlinson R. D.
Published: June 2004

Objectives/Hypothesis: The horizontal angular vestibulo‐ocular reflex (VOR) plays an important role in stabilizing images on the retina throughout head rotations. Current evidence suggests that the VOR behaves linearly at low velocities and nonlinearly at high velocities. The aim of the research was to evaluate and characterize the normal behavior of the reflex evoked by high‐velocity head rotations.

Study Design: Case control study.

Methods: Manually applied head‐thrust movements with peak velocities in the range of 100° to 500°/s and peak accelerations up to 7,000°/s 2 were performed on normal volunteers. These head thrusts were comparable with those described in detail by Halmagi and coworkers. Eye and head movements were recorded using the magnetic search coil method.

Results: The gain of the VOR is linear at low velocities and saturates at head velocities greater than 350°/s. The values for the normal gain of the reflex were approximated by means of the area between two nonlinear functions. The directional difference parameter, exploring the symmetry of the reflex, indicated that the VOR in normal subjects is symmetric.

Conclusion: The gain of the VOR in individuals with intact vestibular function is nonlinear at high angular head velocities. We propose a quantitative means using two nonlinear functions to characterize the normal range of values for the gain of the VOR in individuals with normal vestibular function. A directional difference parameter used in conjunction with the normal range of gains can detect small differences in the symmetry of the VOR and, consequently, reveal unilateral vestibular loss.
Fabrication of Tissue Engineered Tympanic Membrane Patches Using Computer‐Aided Design and Injection Molding
Authors: Hott Morgan E. , Megerian Cliff A. , Beane Rich , Bonassar Lawrence J.
Published: June 2004

Objectives/Hypothesis: The goal of the current study was to use computer‐aided design and injection molding technologies to tissue engineer precisely shaped cartilage in the shape of butterfly tympanic membrane patches out of chondrocyte‐seeded calcium alginate gels.

Methods: Molds were designed on SolidWorks 2000 and built out of acrylonitrile butadiene styrene (ABS) using fused deposition modeling (FDM). Tympanic membrane patches were fabricated using bovine articular chondrocytes seeded at 50 × 106 cells/mL in 2% calcium alginate gels. Molded patches were cultured in vitro for up to 10 weeks and assessed biochemically, morphologically, and histologically.

Results: Unmolded patches demonstrated outstanding dimensional fidelity, with a volumetric precision of at least 3 μL, and maintained their shape well for up to 10 weeks of in vitro culture. Glycosaminoglycan and collagen content increased steadily over 10 weeks in culture, demonstrating continual deposition of new extracellular matrix consistent with new tissue development.

Conclusions: The use of computer‐aided design and injection molding technologies allows for the fabrication of very small, precisely shaped chondrocyte‐seeded calcium alginate structures that faithfully maintain their shape during in vitro culture. In vitro fabrication of tympanic membrane patches with a precisely controlled geometry may have the potential to provide a minimally invasive alternative to traditional methods for the repair of chronic tympanic membrane perforations.
Quantitative RT-PCR Analysis of Uncoupling Protein Isoforms in Mouse Brain Cortex: Methodological Optimization and Comparison of Expression with Brown Adipose Tissue and Skeletal Muscle
Authors: Lengacher Sylvain , Magistretti Pierre J. , Pellerin Luc
Published: June 2004

Uncoupling proteins (UCPs) present in the inner mitochondrial membrane are involved in uncoupling respiration from ATP synthesis. Five UCP isoforms have been identified but information about their presence and level of expression in the central nervous system remains incomplete. To determine the nature and proportion of UCP isoform mRNAs present in brain cortex, we developed and optimized a specific quantitative reverse-transcription polymerase chain reaction procedure. Optimal range of RNA concentrations to be used in the reverse-transcriptase reaction was determined. Primer design and concentration were optimized for each target gene while polymerase chain reaction efficiency was assessed for a range of reverse-transcriptase dilutions. Genomic contribution to the quantitative signal was evaluated for each isoform and minimized. Three reference genes were tested for normalization, and β-actin was found to be the most stable among tissues. Results indicate that brain cortex contains significant amounts of all UCP mRNAs, with UCP5 and UCP4 being the most abundant, as opposed to brown adipose tissue and skeletal muscle, which predominantly express UCP1 and UCP3, respectively. These data provide a first quantitative assessment of UCP mRNA expression in mouse brain, showing the presence of all five isoforms with distinct proportions, thus suggesting specific roles in the central nervous system.
Sustained Poststimulus Elevation in Cerebral Oxygen Utilization after Vascular Recovery
Authors: Lu Hanzhang , Golay Xavier , Pekar James J. , van Zijl Peter C. M.
Published: June 2004

The brain's response to functional activation is characterized by focal increases in cerebral blood flow. It is generally assumed that this hyperemia is a direct response to the energy demands of activation, the so-called flow-metabolism coupling. Here we report experimental evidence that increases in oxygen metabolism can occur after activation without increases in flow. When using multimodality functional MRI (fMRI) to study visual activation in human brain, we observed a postactivation period of about 30 seconds during which oxygen consumption remained elevated, while blood flow and volume had already returned to baseline levels. The finding of such a prolonged and complete dissociation of vascular response and energy metabolism during the poststimulus period indicates that increased metabolic demand needs not per se cause a concomitant increase in blood flow. The results also show that the postactivation undershoot after the positive blood-oxygen-level-dependent hemodynamic response in fMRI should be reinterpreted as a continued elevation of oxygen metabolism, rather than a delayed blood volume compliance.
Removal of N‐terminal methionine from recombinant proteins by engineered E. coli methionine aminopeptidase
Authors: Liao You‐Di , Jeng Jen‐Chong , Wang Chiu‐Feng , Wang Sui‐Chi , Chang Shu‐Ting
Published: June 2004

The removal of N‐terminal translation initiator Met by methionine aminopeptidase (MetAP) is often crucial for the function and stability of proteins. On the basis of crystal structure and sequence alignment of MetAPs, we have engineered Escherichia coli MetAP by the mutation of three residues, Y168G, M206T, Q233G, in the substrate‐binding pocket. Our engineered MetAPs are able to remove the Met from bulky or acidic penultimate residues, such as Met, His, Asp, Asn, Glu, Gln, Leu, Ile, Tyr, and Trp, as well as from small residues. The penultimate residue, the second residue after Met, was further removed if the antepenultimate residue, the third residue after Met, was small. By the coexpression of engineered MetAP in E. coli through the same or a separate vector, we have successfully produced recombinant proteins possessing an innate N terminus, such as onconase, an antitumor ribonuclease from the frog Rana pipiens. The N‐terminal pyroglutamate of recombinant onconase is critical for its structural integrity, catalytic activity, and cyto‐toxicity. On the basis of N‐terminal sequence information in the protein database, 85%–90% of recombinant proteins should be produced in authentic form by our engineered MetAPs.
Monoclonal antibodies assisting refolding of firefly luciferase
Authors: Xu Qin , Xie Zhiqun , Ding Jianfang , Lin Sheng‐Xiang , Xu Genjun
Published: June 2004

The reactivation efficiency in the refolding of denatured luciferase in the presence and the absence of monoclonal antibodies (mAbs) has been studied. Luciferase could be partially reactivated when the protein was denatured in high concentrations of guanidium chloride (GdmCl; >4.5 M) and the refolding was carried out in very low protein concentrations. The refolding yield was, however, significantly lower when it was performed on luciferase that had been denatured with lower concentrations of GdmCl. The efficiency of refolding decreases when the formation of aggregates increases. Three of the five luciferase mAbs tested (4G3, N2E3, S2G10) dramatically increased the yield of reactivation and simultaneously eliminated the formation of aggregates. It is proposed that these mAbs assisted the refolding of luciferase by binding to the exposed hydrophobic surface of the refolding intermediate, thus preventing it from aggregating. The epitopes interacting with these refolding‐assisting mAbs are all located in the A‐subdomain of the N‐terminal region of luciferase. These results have also shed light on the structural features of the intermediate and its interface involved in protein aggregate formation, contributing to the understanding of the protein folding mechanism.
The human serpin proteinase inhibitor‐9 self‐associates at physiological temperatures
Authors: Benning Lauren N. , Whisstock James C. , Sun Jiuru , Bird Phillip I. , Bottomley Stephen P.
Published: June 2004

The metastable serpin architecture is perturbed by extremes of temperature, pH, or changes in primary sequence resulting in the formation of inactive, polymeric conformations. Polymerization of a number of human serpins in vivo leads to diseases such as emphysema, thrombosis, and dementia, and in these cases mutations are present within the gene encoding the aggregating protein. Here we show that aggregation of the human serpin, proteinase inhibitor‐9 (PI‐9), occurs under physiological conditions, and forms aggregates that are morphologically distinct from previously characterized serpin polymers. Incubation of monomeric PI‐9 at 37°C leads to the rapid formation of aggregated PI‐9. Using a variety of spectroscopic methods we analyzed the nature of the structures formed after incubation at 37°C. Electron microscopy showed that PI‐9 forms ordered circular and elongated‐type aggregates, which also bind the fluorescent dye Thioflavin T. Our data show that in vitro wild‐type PI‐9 forms aggregates at physiological temperatures. The biological implications of PI‐9 aggregates at physiological temperatures are discussed.
Biophysical characterization of the free IκBα ankyrin repeat domain in solution
Authors: Croy Carrie Hughes , Bergqvist Simon , Huxford Tom , Ghosh Gourisankar , Komives Elizabeth A.
Published: June 2004

The crystal structure of IκBα in complex with the transcription factor, nuclear factor κ‐B (NF‐κB) shows six ankyrin repeats, which are all ordered. Electron density was not observed for most of the residues within the PEST sequence, although it is required for high‐affinity binding. To characterize the folded state of IκBα (67–317) when it is not in complex with NF‐κB, we have carried out circular dichroism (CD) spectroscopy, 8‐anilino‐1‐napthalenesulphonic acid (ANS) binding, differential scanning calorimetry, and amide hydrogen/deuterium exchange experiments. The CD spectrum shows the presence of helical structure, consistent with other ankyrin repeat proteins. The large amount of ANS‐binding and amide exchange suggest that the protein may have molten globule character. The amide exchange experiments show that the third ankyrin repeat is the most compact, the second and fourth repeats are somewhat less compact, and the first and sixth repeats are solvent exposed. The PEST extension is also highly solvent accessible. Iκ Bα unfolds with a Tm of 42°C, and forms a soluble aggregate that sequesters helical and variable loop parts of the first, fourth, and sixth repeats and the PEST extension. The second and third repeats, which conform most closely to a consensus for stable ankyrin repeats, appear to remain outside of the aggregate. The ramifications of these observations for the biological function of IκBα are discussed.
Does Regime Type Really Matter for Economic Growth?
Authors: DITTMER TIMOTHY , NICKS PAUL
Published: June 2004

ABSTRACT  This article reports on an attempt to duplicate the results of “Regime, Polity, and Economic Growth: The Latin American Experience,” published in the Winter 1995 issue of Growth and Change. The original article used the Parks method to analyze cross section time series data, and concluded that after controlling for other relevant variables military governments have lower rates of economic growth than their civilian counterparts. Using data provided by the original researcher, and using various regression techniques including the Parks method, we were not able to reproduce the original results. We attribute this to problems in both the original data and regression techniques.
Taiwanese Immigrant Entrepreneurs in Canada and Transnational Social Space
Authors: Wong Lloyd L.
Published: June 2004

This article explores the migration of Taiwanese immigrant entrepreneurs to Canada and their transnationalism. Their presence in Canada is documented and described with statistical data on their demographic characteristics, human capital, and economic capital. An assessment of their transnationalism is provided by primary qualitative data gathered through in‐depth interviews. Overall, the review of the literature on Taiwanese migration to various countries, and their transnationalism, indicates that research has primarily been conducted in Australia and the United States, while it remained understudied in Canada. The article makes a case for contextualizing Taiwanese entrepreneurial migration in terms of a global immigration marketplace and the specific business migration programmes in Australia, United States, and Canada. Further, the article argues for the appropriateness of conceptualizing these Taiwanese entrepreneurs as operating within the theoretical framework of transnational social space. The findings on transnational social space include the importance of transnational familial networks, transnational business circuits, and transmigration. Transnational familial networks constitute a form of “capital” as the dispersal is a “resource”. The transnational business circuits include three types: (1) Asian production‐North American distribution; (2) retail chains; and (3) import‐export, all spatially distributed with their multiple national sites. In selected areas of the presentation and discussion of the data the policy implications of the findings are explored. These include discussion of the implications of this transnationalism on Canadian policies such as immigration, multiculturalism, business development, international trade, economic development, and citizenship. There is clearly a lack of harmonization among migration policy and other social and economic policies in Canada. While Canadian multiculturalism policy facilitates transnationalism, Canadian citizenship policy is shown to conflict with and discourage transnational practices.
A convenient and versatile hydroponic cultivation system for Arabidopsis thaliana
Authors: Norén Hanna , Svensson Per , Andersson Bertil
Published: June 2004

A versatile two‐step cultivation procedure for Arabidopsis thaliana is described for the production of large quantities of leaf material suitable for biochemical and biophysical analysis. The first step comprises a miniature greenhouse made out of a plastic pipette box to grow the seedlings to the six‐leaf stage. For continued growth, the seedlings are transferred to hydroponic cultivation using an opaque container covered by a styrofoam lid. Transfer of the small seedlings to hydroponic culture is facilitated by growth in separate pipette tips, which protects vulnerable roots from damage. The hydroponic cultivation system is easy to scale‐up and produces large amounts of relatively large leaves and roots. This hydroponic system produces enough plant material to make Arabidopsis a feasible model for biochemical and biophysical experiments, which can be combined with the available genetic information to address various aspects of plant functional genomics.
Starch metabolism in developing strawberry (Fragaria × ananassa) fruits
Authors: Souleyre Edwige J. F. , Iannetta Pietro P. M. , Ross Heather A. , Hancock Robert D. , Shepherd Louise V. T. , Viola Roberto , Taylor Mark A. , Davies Howard V.
Published: June 2004

Fruit starch reserves can be an important contributor to the sugar content of some ripe fruit, and despite the relatively high financial premiums (compared to other fruit) commanded by ripe strawberries, neither their starch or sugar biochemistry has been examined in detail. This study assessed the rate of starch biosynthesis and breakdown in developing strawberry and sought to determine the temporal changes in the activities of selected enzymes known to be involved in sucrose‐starch interconversions. Scanning electron microscopy revealed that starch levels appeared greatest in immature strawberry (Fragaria×ananassa, cv. Elsanta) at 7 days postanthesis, as evidenced by a decrease in the number of cells containing starch granules as ripening progressed. Levels of key enzymes of starch and sugar metabolism estimated using Western blotting and enzyme activity analysis showed that activities did not correlate with antigen levels. In particular, enzyme activity recovery experiments indicated that losses were due to non‐proteinaceous inhibitors, and in particular protein binding: highlighting the potential for misinterpretation of enzyme activity data gathered from ripening (strawberry) fruit tissue extracts. Consequently, in vitro experiments using [U‐14C] glucose revealed that incorporation to starch is low (11%) at the earliest developmental stages when starch content is greatest. Starch synthesis rate then declines to non‐detectable levels as fruit expand and ripen. These results show that starch accumulates extremely early in the fruit formation process and that starch degradation predominates during fruit growth and development. We estimate that breakdown of transient starch can contribute up to 3% of the sugar accumulated in ripe fruit.
Using Risk Assessment, Benefit‐Cost Analysis, and Real Options to Implement a Precautionary Principle
Authors: Farrow Scott
Published: June 2004

Risk assessment is an established methodology for environmental and public health issues. However, economists' core approach to both risk assessment and risk management, benefit‐cost analysis, often fails to transparently evaluate variability in a way that is a trademark of quantitative risk assessment. Concurrently, environmental advocates are proposing new management criteria based on a vaguely framed “Precautionary Principle.” This manuscript demonstrates how risk assessment techniques for characterizing variability, benefit‐cost analysis, and decision‐making criteria under uncertainty and irreversibility can be combined. The result is a quantifiable, case‐specific, and risk‐dependent “precautionary” threshold for action compared to standard benefit‐cost approaches. The Clean Air Act and the regulation of genetically modified corn provide applications.
Changes in appearance and schizotypy in normal subjects
Authors: à Campo Joost , Nijman Henk , Merckelbach Harald
Published: June 2004

Background:

Anecdotal reports suggest that drastic changes in physical appearance may signal psychotic decompensation in schizophrenic patients.

Objective:

The current study sought to explore the association between changes in appearance and psychotic vulnerability in a more systematic fashion.

Methods:

A sample of undergraduates (n = 171) completed the Changes in Appearance Scale (CAS), which assesses frequency and nature of changes in outlook, along with a Schizotypy Scale (STA), the Maudsley Obsessive Compulsive Inventory (MOCI), the Fear Questionnaire (FQ) and the Beck Depression Inventory (BDI).

Results:

A modest but significant correlation was found between the CAS and STA scores. For the other symptom measures (MOCI, FQ, and BDI), no association with self-reported changes in physical appearance emerged.

Conclusions:

Changes in physical appearance are found to be significantly associated to mild (pre)psychotic symptoms.
An Exegesis on Currency and Banking Crises
Authors: Breuer Janice Boucher
Published: June 2004

Abstract.  This paper reviews the literature on currency and banking crises. Currency and banking crises are characterized according to some standards in the literature and their historical record summarized. The development of the literature from first through fourth‐generation, or so‐called ‘institutional’ models is reviewed. A digression on institutions is provided along with some sidebars on the development of the literature on institutions as it relates to economic growth. The empirical research on third‐generation (or twin crises) models and on institutional models of currency and banking crises, which are so far scarce, is covered too. A summary of the main policy issues for dealing with financial crises is presented. The paper closes with an emphasis on institutions and a call for more research directed at institutions and their role in the financial system.
Xeno‐implantation of pig chondrocytes into rabbit to treat localized articular cartilage defects: an animal model
Authors: Ramallal Manuel , Maneiro Emilia , López Eduardo , Fuentes‐Boquete Isaac , López‐Armada María J. , Fernández‐Sueiro José L. , Galdo Fausto , De Toro Francisco J. , Blanco Francisco J.
Published: June 2004

Articular cartilage has only a limited ability to regenerate. The transplantation of autologous chondrocytes is currently used to treat focal defects in human articular cartilage, although use of organs, tissues, or cells from different species is being investigated as an alternative treatment. The object of this study was to use xeno‐transplantation of cultured pig chondrocytes for the repair of rabbit chondral defects, and to analyze the significance of tissue rejection in this animal model. Partial chondral defects, including removal of cartilage tissue and a part of the subchondral bone, were created in the lateral femoral condyles of 30 adult New Zealand White rabbits. A periosteal flap was sutured to the native cartilage with the cambium layer facing the defect. As a control, culture medium was injected into the defect void of one group of rabbits while in a treatment group, chondrocytes, isolated from normal femoral pig cartilage, were injected into the defect void. All rabbits were killed by 24 weeks. Macroscopic changes of the cartilage were analyzed using Mankin's score. The distal femoral portion was studied histologically using hematoxylin and eosin, alcian blue, toluidine blue, and Mason's trichrome. Pig cells and pig genetic material were detected in the neo‐synthesized tissue by immunohistochemical detection of SLA‐II‐DQ and polymerase chain reaction analysis of the gene SLA‐II‐DQB. The synovial membrane was studied histologically by hematoxylin and eosin staining. In the control group, on average, less than 25 percent of the chondral defect was filled. The repair tissue had an irregular surface with few cells similar to chondrocytes or fibroblasts and a minimal formation of extracellular matrix. In the treatment group, the chondral defect was approximately 90 percent filled with good integration between the neo‐synthesized cartilage and the native cartilage. The repair tissue had a smooth surface with cells similar to chondrocytes and a hyaline‐like extracellular matrix. The neo‐synthesized cartilage was morphologically similar to hyaline cartilage. Importantly, there were no signs of graft‐vs.‐host rejections or infiltration by immune cells. In the neo‐synthesized tissue, pig genetic material was detected in 27 ± 5 percent of all cells. These cells containing pig genetic material were distributed throughout the neo‐synthesized cartilage. We conclude that the xeno‐transplantation of chondrocytes could be an alternative method for the repair of articular cartilage defects.
Molecular, histologic, and gross phenotype of skin wound healing in red Duroc pigs reveals an abnormal healing phenotype of hypercontracted, hyperpigmented scarring
Authors: Gallant Corrie L. , Olson Merle E. , Hart David A.
Published: June 2004

This study examined dermal wound healing in juvenile red Duroc pigs and determined that these animals exhibit a unique healing phenotype at multiple levels. Gross and histologic analysis revealed that full‐thickness and deep dermal (1.8 mm deep) wounds both heal via formation of hypercontracted, hyperpigmented scars. Molecular analysis using reverse‐transcriptase polymerase chain reaction and porcine‐specific primer sets revealed that types I and III collagen, heat shock protein 47, bone morphogenetic protein‐1, several proteoglycans, and tissue inhibitor of metalloproteinases 1–3 all showed a unique biphasic pattern of mRNA expression compared to previous results with Yorkshire pigs. This pattern was characterized by an initial peak of expression early after wounding, followed by a return to near‐normal levels by days 28–42, and then a second increase in mRNA levels at days 56–70. The second phase of increased gene expression correlated with an increased collagen deposition as observed by picrosirius red staining and polarizing light microscopy. Reverse‐transcriptase polymerase chain reaction analysis also revealed a prolonged expression of matrix metalloproteinase‐2 compared to previous findings in the Yorkshire strain. Further characterization of the genetics and molecular biology associated with the red Duroc phenotype may provide insight into aberrant human wound healing.
Full‐thickness wounding of the mouse tail as a model for delayed wound healing: accelerated wound closure in Smad3 knock‐out mice
Authors: Falanga Vincent , Schrayer David , Cha Jisun , Butmarc Janet , Carson Polly , Roberts Anita B. , Kim Seong‐Jin
Published: June 2004

Experimentally induced wounds in animal models are useful in gaining a better understanding of the cellular and molecular processes of wound healing, and in the initial evaluation of the safety and effectiveness of potential therapeutic agents. However, studying delayed healing has proved difficult in animals, whose wounds heal within a few days. In this report, we describe a novel method for establishing mouse wounds that require up to 3 weeks or more for complete closure, and we show the validity of this model in Smad3 null mice, which are known to display accelerated healing. Full‐thickness wounds, measuring 0.3 by 1.0 cm, were made down to fascia on the dorsal aspect of the mouse tail in Smad3 knock‐out mice and control littermates, approximately 1 cm distal to the body of the animal. The wounds were left to heal by secondary intention and were assessed histologically by computerized planimetry for wound closure at various times after wounding. The wounds in wild‐type mice displayed delayed healing, with full closure occurring between 14 and 25 days after wounding. Complete closure of similar wounds in Smad3 null mice healed 30 percent faster (p < 0.01). By immunostaining for ki67, a marker for proliferation, Smad3 null animals also showed increased proliferation of dermal wound cells by day 4 after wounding. Cultured dermal fibroblasts from Smad3 null mice had increased baseline DNA synthesis and, interestingly, an enhanced response to transforming growth factor‐β1. By Western blot analysis, Smad3 null mice fibroblasts showed a compensatory increase in mitogen‐activated protein kinase phosphorylation in response to transforming growth factor‐β1, suggesting that mitogen‐activated protein kinase overcompensation together with loss of Smad3 may be involved in the modulation of faster healing. We conclude that this novel tail‐wounding model may be useful for studying delayed wound closure.
Cord plasma concentrations of adiponectin and leptin in healthy term neonates: positive correlation with birthweight and neonatal adiposity
Authors: Tsai Po‐Jung , Yu Chun‐Hsien , Hsu Shih‐Penn , Lee Yu‐Hsiang , Chiou Chuen‐Hua , Hsu Yu‐Wen , Ho Su‐Chen , Chu Chun‐Hong
Published: June 2004

objective  Adiponectin is negatively associated with leptin, insulin and obesity in children and adults. Whereas increases in fetal insulin and leptin are associated with increased weight and adiposity at birth, the role of adiponectin in fetal growth has not yet been determined. The aims of this study were to examine the relationships between adiponectin and insulin, leptin, weight and adiposity at birth in healthy term infants.

design and methods  Anthropometric parameters including weight, length, circumferences and skinfold thickness were measured, and plasma lipid profiles, insulin, leptin and adiponectin concentrations in cord blood samples from 226 singleton infants born at term after uncomplicated pregnancies were assayed.

results  Cord plasma adiponectin, leptin and insulin levels correlated significantly and positively with birthweight (P = 0·001, P < 0·001, P < 0·001, respectively) and the sum of skinfold thicknesses (P < 0·001, P < 0·001, P < 0·001, respectively). Mean cord plasma adiponectin and leptin levels, but not insulin level, were significantly higher in large‐for‐gestational‐age (LGA) infants compared with appropriate‐for‐gestational‐age (AGA) infants. Cord plasma leptin concentration, but not adiponectin concentration, was significantly higher in female infants than in male infants (P = 0·003 and P = 0·94, respectively). Cord plasma adiponectin concentration correlated positively with leptin level (P = 0·007) but not with insulin level (P = 0·78).

conclusions  High adiponectin levels are present in the cord blood. Cord plasma adiponectin and leptin levels are positively correlated with birthweight and adiposity. This suggests that adiponectin may be involved in regulating fetal growth.
Completion thyroidectomy in patients with thyroid cancer who initially underwent unilateral operation
Authors: Kim Eun Sook , Kim Tae Yong , Koh Jung Min , Kim Young Il , Hong Suck Joon , Kim Won Bae , Shong Young Kee
Published: June 2004

background  In some instances, thyroid cancer may be diagnosed with histological examination after resection of putative or suspected benign nodule. In these cases, completion thyroidectomy followed by radioiodine ablation is usually recommended to prevent recurrence. If small intrathyroidal cancer is found, completion thyroidectomy may not be performed. Many patients have separate cancers in the contralateral lobe and in these cases completion thyroidectomy is essential even though primary tumour is small and limited within thyroid.

objective  We analysed the frequency of malignant lesions in the contralateral lobe after completion thyroidectomy and assessed the predictive factors that may anticipate the presence of malignant lesion that may necessitate completion thyroidectomy.

patients  Between 1995 and 2001, 243 patients were operated under the cytological diagnosis of follicular neoplasm. A total of 214 of them underwent lobectomy and isthmectomy and 81 turned out to have malignant disease in the resected lobe and they underwent completion thyroidectomy within a week to 6 months after the permanent section diagnosis of cancer. Their mean age was 40·7 ± 12·1 years (range 14–71 years).

results  After initial surgery, 53 patients had follicular carcinoma, 24 papillary carcinoma, one Hürthle cell carcinoma, one medullary, one insular and one anaplastic carcinoma. Mean tumour size was 4·1 ± 2·6 cm (range 0·9–11 cm). After completion thyroidectomy, factors predicting the presence of cancer in the contralateral lobe were assessed according to clinical parameters and pathologic findings in ipsilateral lobe. First surgery revealed cancer multifocality in 34 cases, perithyroidal tumour extension in six and regional lymph node metastases in three. After completion thyroidectomy, 29 of the 81 patients revealed additional cancer in the contralateral lobe. Age, sex, size or pathologic type of the primary tumour was not associated with the presence of additional tumour in the contralateral lobe. Cancer multifocality in the ipsilateral lobe was the only significant variable to predict the presence of additional cancer in the contralateral lobe (relative risk = 6·03, confidence interval 2·23–16·35). Coexistence of benign nodule in ipsilateral lobe was not associated with increased cancer risk in the contralateral lobe.

conclusions  When diagnosed as thyroid cancer after unilateral surgery, the only predictive factor for the presence of additional contralateral cancer was multifocality of cancer in the ipsilateral lobe. We suggest that completion thyroidectomy is mandatory if multifocal cancers are found in the resected lobe, even though the cancers are very small and limited within the thyroid.
Does iodine‐131 meta‐iodobenzylguanidine (MIBG) scintigraphy have an impact on the management of sporadic and familial phaeochromocytoma?
Authors: Taïeb D. , Sebag F. , Hubbard J. G. , Mundler O. , Henry J. F. , Conte‐Devolx B.
Published: June 2004

objectives  To assess the impact of [131I]meta‐iodobenzylguanidine (131MIBG) scintigraphy on the management of phaeochromocytoma.

design and patients  Between 1982 and 2002, 83 patients with histologically proven phaeochromocytoma or paraganglioma were investigated using 131MIBG scintigraphy. Seventeen of these patients, with a hereditary form of the disease, presented with 23 phaeochromocytomas [three neurofibromatosis type 1 (NF1), five von Hippel–Lindau disease (VHL), eight multiple endocrine neoplasia type 2A (MEN2A) and one type 2B (MEN2B)].

results  MIBG uptake was observed in 44/54 sporadic phaeochromocytomas (sensitivity 81·5%), 14/23 familial phaeochromocytomas (60·9%), 3/6 paragangliomas and 4/6 malignant phaeochromocytomas. No significant correlations were found between the degree of tracer uptake, tumour size and urinary metanephrine levels. No patients undergoing surgery for sporadic phaeochromocytoma had a second tumour located. Nine of 54 sporadic phaeochromocytomas had normal or mildly elevated urinary metanephrine levels (< 1·5 greater than normal). In eight of these patients, 131MIBG was positive and confirmed the diagnosis of phaeochromocytoma. In malignant phaeochromocytomas (n = 6), MIBG demonstrated additional lesions not detected with computed tomography (CT) and/or magnetic resonance imaging (MRI) in three cases. The MIBG findings in the group with apparently sporadic paragangliomas (n = 6) were negative in four cases and failed to detect a cervical lesion in one multifocal paraganglioma.

conclusion  131MIBG was useful in confirming the diagnosis in phaeochromocytomas with low levels of catecholamine secretion. It contributed little to the management of patients when used as a means of screening for multifocality in sporadic phaeochromocytoma, or the management of patients with familial phaeochromocytoma. However, MIBG can be an informative method of investigation when dealing with malignant/ectopic forms, although the sensitivity of MIBG is lower in this group of patients.
A model of Internet standards adoption: the case of IPv6
Authors: Hovav Anat , Patnayakuni Ravi , Schuff David
Published: June 2004

Abstract.  The Internet presents a unique environment in which to study adoption. This is because of its composition of autonomous entities that are otherwise strongly interrelated. Our model of Internet standards adoption (ISA) combines diffusion of innovation and economics of adoption literature to present an integrative model. This model proposes that the adoption of Internet‐based standards is dependent upon two dimensions: the usefulness of the features to the potential adopter, and the conduciveness of the environment to adoption of the standard. This model accounts for not only the traditional dichotomous view of adoption, but also includes the notion of ‘partial adoption’, where both old and new standards can coexist for extended periods of time. As a demonstration, we apply the ISA model to the next generation Internet protocol Internet Protocol version 6 (IPv6). Despite its ostensible superiority, IPv6 has not been widely adopted. In this paper we discuss the reasons why this might be the case. Our analysis also draws wider conclusions about the adoption of Internet standards: in particular, the importance of transitional technologies between the old and new standards and the need for co‐ordinated government polices which encourage adoption. Our analysis also indicates that geopolitical boundaries may have a considerable impact on the adoption of Internet standards.
Short cycle time systems development
Authors: Baskerville Richard , Pries‐Heje Jan
Published: June 2004

Abstract. An analysis of two studies in the US and Denmark reveals that short cycle time systems development is a new form that can be clearly distinguished among other forms. The distinction consists of a package of five systems development practices. These practices include a focus on completion speed, release‐oriented parallel prototyping, adherence to a fixed architecture, negotiable quality, and an ideal workforce. The package is consistent with amethodical development concepts. Systems are not built in a single project that completes with a delivery, but rather are continually ‘growing’ to adapt to an organizational emergence.
Changes in properties of short‐term‐use soft liners after thermocycling
Authors: Park S.‐K. , Lee Y.‐K. , Lim B.‐S. , Kim C.‐W.
Published: June 2004

summary  The objectives of this study were to determine the influence of thermocycling on the changes of elastic modulus (EM) and colour, and to evaluate cytotoxicity after repeated elution of short‐term‐use soft liners. Three short‐term‐use soft liners [soft acrylic‐based Coe Comfort (CCM), Coe Soft (CST) and Soft Liner (SFL)], and long‐term‐use silicone‐based Tokuso Soft Liner (TSL) acting as a control were studied. EM was measured at baseline and after thermocycling at 5–55 °C for 500, 1000, 1500 and 2000 cycles. For the colour measurement, specimens in discs 20 mm in diameter and 1 mm in thickness were prepared, attached to a denture base resin plate, and then thermocycled as above. Colour change (ΔE*) was measured according to the Commission Internationale de l'Eclairage (CIE) L*, a*, and b* scale on a spectrophotometer. For the cytotoxicity evaluation, specimens were eluted for 24 h in culture media repeatedly up to four times, and MTT assay (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) was performed. EM of CCM and CST increased up to 1500 and 1000 cycles of thermocycling respectively. EM of SFL gradually increased up to 2000 cycles, and that of TSL increased after 500 cycles and did not change after then. ΔE* of soft liners after 2000 cycles except CCM were 3·68–8·65. EM increased up to 1000–1500 cycles, and perceivable colour change was observed after 2000 cycles in most materials. Therefore, short‐term‐use soft liners should be used within a limited time, although the cytotoxicity decreased after repeated elution.
Inhibition of human pulpal gelatinases (MMP‐2 and MMP‐9) by zinc oxide cements
Authors: Santos M. C. L. G. , De Souza A. P. , Gerlach R. F. , Trevilatto P. C. , Scarel‐Caminaga R. M. , Line S. R. P.
Published: June 2004

summary The interaction between metal ions and the oral environment is a major subject matter in dental research. Matrix metalloproteinases (MMPs) have been implicated in several pathological and physiological processes such as, periodontal tissue destruction, root caries, dentin calcification and pulpal inflammation. The aim of this work was to test the effect of zinc released from zinc oxide–eugenol (ZOE) cements, on the activity of the major pulpal gelatinolytic MMPs. Pulpal explants were cultured overnight in Dulbecco's Modified Eagle Medium and the activity of secreted enzymes was analysed by gelatin zymography in buffer conditionated with diverse ZOE cements. Phenanthroline, a zinc chelator, was used to revert the inhibition of MMPs caused by zinc. The major gelatinolytic proteinases present in the conditioned media were characterized as MMP‐2 and MMP‐9 by immunoprecipitation. All ZOE cements inhibited MMPs activity, whereas phenanthroline could partially revert the inhibition caused by plain ZOE and Intermediate Restorative Material (IRM).