bluuebunny/crossref_metadata_2025 huggingface dataset:
The complex life of WT1
Authors: Wagner Kay-Dietrich , Wagner Nicole , Schedl Andreas
Published: March 2003

The Wilms' tumour gene, WT1, encodes a zinc-finger transcription factor that is inactivated in a subset of Wilms' tumours. Mutation analysis in human patients and genetic experiments in mice have revealed that WT1 has a role much wider than just tumour suppression. Alternative splicing, RNA editing, and the use of alternative translation initiation sites generate a multitude of isoforms, which seem to have overlapping but also distinct functions during embryonic development and the maintenance of organ function. Recently, mouse strains lacking the WT1(-KTS) or WT1(+KTS) splice variants of exon 9 were generated. More severe defects of kidneys and gonads are found in mice lacking the WT1(-KTS) variant. Animals lacking the WT1(+KTS) variant show disturbed podocyte function and male-to-female sex reversal. Alternative splicing of exon 5, however, might not modify WT1 function dramatically. Recently, it was also described that reduction of WT1 levels in the kidney results in glomerulosclerosis and upregulation of WT1 in the heart might contribute to neovascularization after infarction.
Aberdeen Colles’ fracture brace as a treatment for Colles’ fracture
Authors: Tumia N. , Wardlaw D. , Hallett J. , Deutman R. , Mattsson S. A. , Sandén B.
Published: March 2003

We carried out a randomised, prospective, multicentre clinical trial of the treatment of Colles’ fractures. A total of 339 patients was placed into two groups, those with minimally displaced fractures not requiring manipulation (151 patients) and those with displaced fractures which needed manipulation (188 patients). Treatment was by either a conventional Colles’ plaster cast (a control group) or with a prefabricated functional brace (the Aberdeen Colles’ fracture brace).

Similar results were obtained in both groups with regard to the reduction and to pain scores but the brace provided better grip strength in the early stages of treatment. This was statistically significant after five weeks for both manipulated and non-manipulated fractures. At the tenth day the results were statistically significant only in manipulated fractures. There was no significant difference in the functional outcome between the two treatment groups. However, younger patients and those with less initial displacement had better functional results.
Ultrasound in the management of the position of the femoral head during treatment in a spica cast after reduction of hip dislocation in developmental dysplasia of the hip
Authors: van Douveren F. Q. M. P. , Pruijs H. E. H. , Sakkers R. J. B. , Nievelstein R. A. J. , Beek F. J. A.
Published: March 2003

In this prospective study of 18 hips we compared the efficacy of ultrasound with CT in determining the position of the femoral head in a spica cast after closed or open reduction in children with developmental dysplasia of the hip. Ultrasound was performed through the perineal opening of the cast. With a transinguinal approach, the superior ramus of the pubis, the acetabulum, the femoral head and the femoral neck can be depicted in one plane. The CT and ultrasound images were blinded and reviewed by two of the authors. Ultrasound was inconclusive in the first two reductions since the perineal opening was too small to see all the landmarks in one plane. In the following 16 reductions the landmarks were well defined and interpretation of the CT and ultrasound was similar. The perineal opening in the spica cast should be made in such a way that the ultrasound probe can be positioned in the groin so that the landmarks can be shown in one plane.
Use of the Coventry infant hip screw in the treatment of nonunion of fractures of the distal humerus
Authors: Simonis R. B. , Nuñez V. A. , Khaleel A.
Published: March 2003

Between 1993 and 2000 we treated 14 patients with nonunion of fractures of the distal humerus; 11 had already had previous fixation which had failed. The mean time to surgery was 21 months after injury. All the fractures were very low which made it difficult to obtain a firm hold of the small distal fragment. The problem of fixation was addressed by inserting a Coventry infant hip screw into the humeral condyles. The screw has a thread of wide diameter which gives excellent purchase on the small distal fragment. The condyles can then be compressed on to the humeral shaft using a 4.5 mm narrow tibial dynamic plate. Of these 14 difficult cases of nonunion, 12 progressed to union.
Patient demographics as a predictor of the ten-year survival rate in primary total knee replacement
Authors: Johnson G. Vazquez-Vela , Worland R. L. , Keenan J. , Norambuena N.
Published: March 2003

As the surgical indications for total knee replacement (TKR) expand to include younger, heavier and more active patients, knowledge of the effect of these demographic variables on the outcome and survival of the implant is increasingly important.

Between November 1986 and September 1990, 402 patients underwent 562 primary cemented cruciate-retaining TKRs carried out by a single surgical team. The overall results showed a survival of 96.8% at 14 years with 1.44% lost to follow-up. Evaluating the demographics of these patients showed that certain groups fared significantly less well. The best results were seen in non-obese women with osteoarthritis who were over 60 years of age in whom there was ten-year survival of 99.4%. The worst results were in obese men with osteoarthritis who were less than 60 years of age in whom there was a ten-year survival of 35.7%. Caution should be exercised when considering TKR on a patient with this combination of poor risk factors.

By identifying demographic factors at the time of consultation the surgeon is better able to predict the survival of the TKR. This information is important when considering the best options for treatment of a patient and in providing accurate information during preoperative counselling.
Should the cement mantle around the femoral component be thick or thin?
Authors: Skinner J. A. , Todo S. , Taylor M. , Wang J. S. , Pinskerova V. , Scott G.
Published: March 2003

We have compared the survival and radiological outcome at ten years after total hip replacement using two techniques for preparing the femoral canal. The same prosthesis was used throughout and all operations were performed by the same surgical team. In technique 1 the canal was over-reamed by 2 mm and in technique 2 it was reamed to the same size as the prosthesis. Technique 1 was performed on 92 patients and technique 2 on 97 patients.

The survival at ten years was 97.2% (90.6 to 99.2) for technique 1 and 98.8% (92.9 to 99.8) for technique 2. Vertical migration was greater in technique 1 (1.8 mm versus 1.0 mm at five years; p = 0.36). There were significantly more lytic lesions and radiolucent lines at five years (p = 0.0061) with technique 1. We conclude that technique 2 is not worse and may produce better long- term results than current teaching suggests.
Ultrasonographic imaging of fractures of the clavicle in newborn infants
Authors: Kayser R. , Mahlfeld K. , Heyde C. , Grasshoff H.
Published: March 2003

Fractures of the clavicle in the neonate are usually diagnosed by clinical examination and confirmed by plain radiography. Exposure of newborn infants to irradiation should be avoided if possible. Following the clinical examination of 2978 neonates, 15 had suspected fractures of the clavicle. All were confirmed by ultrasound.

In combination with clinical examination, ultrasound is a satisfactory alternative to radiological assessment for the diagnosis of fractures of the clavicle in newborn children.
Role of posterior stabilisation in the management of tuberculosis of the dorsal and lumbar spine
Authors: Sundararaj G. D. , Behera S. , Ravi V. , Venkatesh K. , Cherian V. M. , Lee V.
Published: March 2003

We present a prospective study of patients with tuberculosis of the dorsal, dorsolumbar and lumbar spine after combined anterior (radical debridement and anterior fusion) and posterior (instrumentation and fusion) surgery. The object was to study the progress of interbody union, the extent of correction of the kyphosis and its maintenance with early mobilisation, and the incidence of graft and implant-related problems. The American Spinal Injury Association (ASIA) score was used to assess the neurological status.

The mean preoperative vertebral loss was highest (0.96) in the dorsal spine. The maximum correction of the kyphosis in the dorsolumbar spine was 17.8°. Loss of correction was maximal in the lumbosacral spine at 13.7°. All patients had firm anterior fusion at a mean of five months. The incidence of infection was 3.9% and of graft-related problems 6.5%.

We conclude that adjuvant posterior stabilisation allows early mobilisation and rehabilitation. Graft-related problems were fewer and the progression and maintenance of correction of the kyphosis were better than with anterior surgery alone. There is no additional risk relating to the use of an implant either posteriorly or anteriorly even when large quantities of pus are present.
The knee-spine syndrome
Authors: Murata Y. , Takahashi K. , Yamagata M. , Hanaoka E. , Moriya H.
Published: March 2003

Degenerative changes of the knee often cause loss of extension. This may affect aspects of posture such as lumbar lordosis. A total of 366 patients underwent radiological examination of the lumbar spine in a standing position. The knee and body angles were measured by physical examination using a goniometer. Limitation of extension of the knee was significantly greater in patients whose lumbar lordosis was 30° or less. Lumbar lordosis was significantly reduced in patients whose limitation of extension of the knee was more than 5°. It decreased over the age of 70 years, and the limitation of extension of the knee increased over the age of 60 years. Our study indicates that symptoms from the lumbar spine may be caused by degenerative changes in the knee. This may be called the ‘knee-spine syndrome’.
Acute correction of lower limb deformity and simultaneous lengthening with a monolateral fixator
Authors: Donnan L. T. , Saleh M. , Rigby A. S.
Published: March 2003

We have reviewed, retrospectively, all children with a lower limb deformity who underwent an acute correction and lengthening with a monolateral fixator between 1987 and 1996. The patients were all under the age of 19 years and had a minimum follow-up of eight months after removal of the fixator. A total of 41 children had 57 corrections and lengthening. Their mean age was 11.3 years (3.2 to 18.7) and there were 23 girls and 18 boys.

The mean maximum correction in any one plane was 23° (7 to 45). In 41 bony segments (either femur or tibia) a uniplanar correction was made while various combinations were carried out in 16. The site of the osteotomy was predominantly diaphyseal, at a mean of 47% (17% to 73%) of the total bone length and the mean length gained was 6.4 cm (1.0 to 17.0).

Univariate analysis identified a moderately strong relationship between the bone healing index (BHI), length gained, maximum correction and grade-II to grade-III complications. For logistic regression analysis the patients were binary coded into two groups; those with a good outcome (BHI ≤ 45 days/cm) and those with a poor outcome (BHI > 45 days/cm). Various factors which may influence the outcome were then analysed by calculating odds ratios with 95% confidence intervals.

This analysis suggested a dose response between increasing angular correction and poor BHI which only reached statistical significance for corrections of larger magnitude. Longer lengthenings were associated with a better BHI while age and the actual bone lengthened had little effect.

Those patients with a maximum angulatory correction of less than 30° in any one plane had an acceptable consolidation time with few major complications. The technique is suitable for femoral deformity and shortening, but should be used with care in the tibia since the risk of a compartment syndrome or neurapraxia is much greater.
Pedicle bone grafting versus transtrochanteric rotational osteotomy for avascular necrosis of the femoral head
Authors: Hasegawa Y. , Sakano S. , Iwase T. , Iwasada S. , Torii S. , Iwata H.
Published: March 2003

Segmental collapse occurs in the early stage of a vascular necrosis (AVN) of the femoral head, and is associated with a poor prognosis. Since it develops at a relatively young age, the long-term outcome after total hip replacement is a major concern. We have compared the long-term results of pedicle bone grafting (PBG) with those of transtrochanteric rotational osteotomy (TRO). In the PBG group there were 23 men (27 hips) and three women (4 hips) with a mean age at the time of surgery of 38 years and a mean follow-up of 13 years. In the TRO group there were 44 men (55 hips) and 19 women (22 hips) with a mean age at the time of surgery of 39 years and a mean follow-up of seven years. Failure was defined as a need for total hip replacement or a Harris hip score below 70.

The long-term results were similar for the two groups. The survival rates at five and ten years were 85% and 67%, respectively, in the PBG group, and 71% and 61%, respectively, in the TRO group, according to Kaplan-Meier survivorship analysis. In the TRO group patients in stage II had significantly better results that those in stage III.
Role of cyclical pressure and particles in the release of M-CSF, chemokines, and PGE2 and their role in loosening of implants
Authors: Sampathkumar K. , Jeyam M. , Evans C. E. , Andrew J. G.
Published: March 2003

Aseptic loosening of orthopaedic implants is usually attributed to the action of wear debris from the prosthesis. Recent studies, however, have also implicated physical pressures in the joint as a further cause of loosening. We have examined the role of both wear debris and pressure on the secretion of two chemokines, MIP-1α and MCP-1, together with M-CSF and PGE2, by human macrophages in vitro.

The results show that pressure alone stimulated the secretion of more M-CSF and PGE2 when compared with control cultures. Particles alone stimulated the secretion of M-CSF and PGE2, when compared with unstimulated control cultures, but did not stimulate the secretion of the two chemokines. Exposure of macrophages to both stimuli simultaneously had no synergistic effect on the secretion of the chemokines, but both M-CSF and PGE2 were increased in a synergistic manner. Our findings suggest that pressure may be an initiating factor for the recruitment of cells into the periprosthetic tissue.
Failure of an uncemented non-porous metal-backed prosthesis with augmentation using impacted allograft for acetabular revision
Authors: Jeffery M. , Scott G. , Freeman M.
Published: March 2003

We have reviewed 29 patients (30 hips) who had undergone revision total hip arthroplasty using a Freeman metal-backed acetabular component and acetabular impaction allografting. The mean follow-up was for 15.3 years (12 to 17).

Five patients (5 hips) died with the prosthesis in situ and four (4 hips) were lost to follow-up. Twelve hips had failed and in the remaining nine there were minor symptoms. The mean time to failure requiring further surgery was nine years. Excluding patients who were lost to follow-up or had died, 72% of the hips were radiologically loose at the last review. The commonest pattern in those requiring revision was failure of the reinforcement ring in adduction with remodelling of the medial wall.

Of the nine patients who had not undergone revision, one with bilateral replacements had no current radiographs and only three of the remaining seven replacements had no radiological signs of loosening.

The short-term results for this technique have been reported to be satisfactory, but in the long term they are not. The factors associated with failure include the design of the prosthesis, which has been implicated in disappointing long-term results when used in primary arthroplasty, but not with the frequency of failure found in this series. It seems that the reliance on peripheral screw fixation over a bed of allograft without bridging the graft does not provide sufficient stability to allow incorporation of the graft.
Painful soft-tissue reaction to injectable Norian SRS calcium phosphate cement after curettage of enchondromas
Authors: Welkerling H. , Raith J. , Kastner N. , Marschall C. , Windhager R.
Published: March 2003

A prospective single-cohort study was designed to include 20 patients with enchondromas but was stopped because of poor early results. Four patients with an enchondroma, three in the proximal humerus and one in the distal femur, were treated by curettage and filling of the defect with Norian SRS cement. Clinical and radiological follow-up including CT and MRI was carried out for 18 months. All three patients with lesions in the proximal humerus had severe pain and limited movement of the shoulder. The radiological and CT appearances of the cement were unchanged at follow-up. There were characteristic appearances of synovitis and periosteitis on MRI in two patients. Since the cement induces a soft-tissue reaction the bony cavity should be sealed with the curetted and burred bone after curettage and introduction of Norian cement, especially in sites where a tourniquet cannot be applied.
Comparison of the surgical approaches for a Chiari pelvic osteotomy
Authors: Ito H. , Matsuno T. , Minami A.
Published: March 2003

We present the mid- to long-term results of the Chiari pelvic osteotomy for dysplastic hips. We followed 135 hips in 129 patients, with a mean age at the time of surgery of 24 years, for a mean of 16.2 years. We used the anterior iliofemoral approach without trochanteric osteotomy in the initial 31 hips. Thereafter, we used transtrochanteric approaches in an attempt to ensure that the osteotomy was at the most appropriate level, and to advance the high-riding greater trochanter distally. The next 79 hips therefore underwent a posterolateral approach and the most recent 25 hips an Ollier lateral U approach. The clinical result was excellent or good in 103 hips (77%). The outcome in 104 hips in which we used a transtrochanteric approach was superior, the osteotomy level was more appropriate and a Trendelenburg gait less common than in 31 hips in which we used an anterior approach. We therefore recommend the use of a transtrochanteric approach in order to ensure that the osteotomy is at an appropriate level and in order to achieve effective distal advancement of the high-riding greater trochanter.
Femoral derotation osteotomy in spastic diplegia
Authors: Pirpiris M. , Trivett A. , Baker R. , Rodda J. , Nattrass G. R. , Graham H. K.
Published: March 2003

We describe the results of a prospective study of 28 children with spastic diplegia and in-toed gait, who had bilateral femoral derotation osteotomies undertaken at either the proximal intertrochanteric or the distal supracondylar level of the femur. Preoperative clinical evaluation and three-dimensional movement analysis determined any additional soft-tissue surgery.

Distal osteotomy was faster with significantly lower blood loss than proximal osteotomy. The children in the distal group achieved independent walking earlier than those in the proximal group (6.9 ± 1.3 v 10.7 ± 1.7 weeks; p < 0.001). Transverse plane kinematics demonstrated clinically significant improvements in rotation of the hip and the foot progression angle in both groups. Correction of rotation of the hip was from 17 ± 11° internal to 3 ± 9.5° external in the proximal group and from 9 ± 14° internal to 4 ± 12.4° external in the distal group. Correction of the foot progression angle was from a mean of 10.0 ± 17.3° internal to 13.0 ± 11.8° external in the proximal group (p < 0.001) compared with a mean of 7.0 ± 19.4° internal to 10.0 ± 12.2° external in the distal group (p < 0.001). Femoral derotation osteotomy at both levels gives comparable excellent correction of rotation of the hip and foot progression angles in children with spastic diplegia.
The use of a closed-suction drain in total knee arthroplasty
Authors: Esler C. N. A. , Blakeway C. , Fiddian N. J.
Published: March 2003

We prospectively randomised 100 patients undergoing cemented total knee replacement to receive either a single deep closed-suction drain or no drain.

The total blood loss was significantly greater in those with a drain (568 ml versus 119 ml, p < 0.01; 95% CI 360 to 520) although those without lost more blood into the dressings (55 ml versus 119 ml, p < 0.01; 95% CI −70 to 10). There was no statistical difference in the postoperative swelling or pain score, or in the incidence of pyrexia, ecchymosis, time at which flexion was regained or the need for manipulation, or in the incidence of infection at a minimum of five years after surgery in the two groups.

We have been unable to provide evidence to support the use of a closed-suction drain in cemented knee arthroplasty. It merely interferes with mobilisation and complicates nursing. Reinfusion drains may, however, prove to be beneficial.
The results of endoprosthetic replacement for tumours of the distal humerus
Authors: Kulkarni A. , Fiorenza F. , Grimer R. J. , Carter S. R. , Tillman R. M.
Published: March 2003

Ten patients underwent endoprosthetic replacement of the distal humerus for bone tumours over a period of 30 years. There were eight primary and two secondary tumours in four men and six women with a mean age of 47.5 years (15 to 76). The mean follow-up was eight years (9 months to 31 years). Four patients required further surgery, three having revision for aseptic loosening; two of these and one other later needing a rebushing. There were no cases of postoperative nerve palsy, infection, local recurrence or mechanical failure of the implant. Four patients died from their disease, all with the prosthesis functioning satisfactorily. At follow-up the mean flexion deformity of the elbow was 15° (0 to 35) and the mean range of flexion was 115° (110 to 135). The functional results showed a mean Toronto extremity salvage score of 73% of normal. Endoprosthetic replacement of the distal humerus and elbow is a satisfactory method of treating these rare tumours.
The effect of knee flexion on the popliteal artery and its surgical significance
Authors: Shetty A. A. , Tindall A. J. , Qureshi F. , Divekar M. , Fernando K. W. K.
Published: March 2003

Total knee replacement and high tibial osteotomy are common orthopaedic operations with low complication rates. Such surgery is in close proximity to the popliteal artery (PA), the behaviour of which during flexion of the knee is poorly understood.

We used Duplex ultrasonography to determine the distance of the PA from the posterior tibial surface at 0° and 90° of flexion in 100 knees. When the knee was flexed the PA was closer to the posterior tibial surface at 1 to 1.5 cm below the joint line in 24% and at 1.5 to 2 cm below the joint line in 15%. There was a high branching anterior tibal artery in 6% of knees. We provide an anatomical account to help to explain our findings by using cadaver dissections, arteriography and static MRI studies.
Effect of smoking on early complications after elective orthopaedic surgery
Authors: Møller A. M. , Pedersen T. , Villebro N. , Munksgaard A.
Published: March 2003

Smoking is an important risk factor for the development of postoperative pulmonary complications after major surgical procedures. We studied 811 consecutive patients who had undergone hip or knee arthroplasty, recording current smoking and drinking habits, any history of chronic disease and such intraoperative factors as the type of anaesthesia and the type and duration of surgery. We recorded any postoperative complications occurring before discharge from hospital. There were 232 smokers (28.6%) and 579 non-smokers.

We found that smoking was the single most important risk factor for the development of postoperative complications, particularly those relating to wound healing, cardiopulmonary complications, and the requirement of postoperative intensive care. A delay in discharge from hospital was usual for those suffering a complication. In those patients requiring prolonged hospitalisation (> 15 days) the proportion of smokers with wound complications was twice that of non-smokers.
Noncovalent Binding of a Reaction Intermediate by a Designed Helix‐Loop‐Helix Motif—Implications for Catalyst Design
Authors: Allert Malin , Baltzer Lars
Published: March 2003

In our search for a catalyst for the transamination reaction of aspartic acid to form oxaloacetate, twenty‐five forty‐two‐residue sequences were designed to fold into helix‐loop‐helix dimers and form binding sites for the key intermediate along the reaction pathway, the aldimine. This intermediate is formed from aspartic acid and the cofactor pyridoxal phosphate. The design of the binding sites followed a strategy in which exclusively noncovalent forces were used for binding the aldimine. Histidine residues were incorporated to catalyse the rate‐limiting 1,3 proton transfer reaction that converts the aldimine into the ketimine, an intermediate that is subsequently hydrolysed to form oxaloacetate and pyridoxamine phosphate. The two most efficient catalysts, T‐4 and T‐16, selected from the pool of sequences by a simple screening procedure, were shown by CD and NMR spectroscopies to bind the aldimine intermediate with dissociation constants in the millimolar range. The mean residue ellipticity of T‐4 in aqueous solution at pH 7.4 and a concentration of 0.75 mM was −18 500 deg cm2 dmol−1. Upon addition of 6 mm l‐aspartic acid and 1.5 mM pyridoxal phosphate to form the aldimine, the mean residue ellipticity changed to −19 900 deg cm2 dmol−1. The corresponding mean residue ellipticities of T‐16 were −21 200 deg cm2 dmol−1 and −24 000 deg cm2 dmol−1. These results show that the helical content increased in the presence of the aldimine, and that the folded polypeptides bound the aldimine. The 1H NMR relaxation time of the imine CH proton of the aldimine was affected by the presence of T‐4 as was the 31P NMR resonance linewidth. The catalytic efficiencies of T‐4 and T‐16 were compared to that of imidazole and found to be more than three orders of magnitude larger. The designed binding sites were thus shown to be capable of binding the aldimine in close proximity to His residues, by noncovalent forces, into conformations that proved to be catalytically active. The results show for the first time the design of well‐defined catalytic sites that bind a reaction intermediate with enzyme‐like affinities under equilibrium conditions and represent an important advance in de novo catalyst design.
Are financial markets efficient? Phase transition in the aggregation of information
Authors: Berg Johannes , Marsili Matteo , Rustichini Aldo , Zecchina Riccardo
Published: March 2003

Financial markets can be considered as collective information processing devices, which aggregate the information on relevant events into market prices. We show that, in a simple model, markets are efficient aggregators of information only if the number of traders is sufficiently large compared to the number of relevant events. The transition to an efficient market occurs through a phase transition, well known from critical phenomena in physics. © 2003 Wiley Periodicals, Inc.
Dynamics of social networks
Authors: Ebel Holger , Davidsen Jörn , Bornholdt Stefan
Published: March 2003

Complex networks such as the World Wide Web, the web of human sexual contacts, or criminal networks often do not have an engineered architecture but instead are self‐organized by the actions of a large number of individuals. From these local interactions nontrivial global phenomena can emerge as small‐world properties or scale‐free degree distributions. A simple model for the evolution of acquaintance networks highlights the essential dynamical ingredients necessary to obtain such complex network structures. The model generates highly clustered networks with small average path lengths and scale‐free as well as exponential degree distributions. It compares well with experimental data of social networks, as for example, coauthorship networks in high energy physics. © 2003 Wiley Periodicals, Inc.
Viral evolution under the pressure of an adaptive immune system: Optimal mutation rates for viral escape
Authors: Kamp Christel , Wilke Claus O. , Adami Christoph , Bornholdt Stefan
Published: March 2003

Based on a recent model of evolving viruses competing with an adapting immune system (Kamp and Bornholdt, Co‐evolution of quasispecies: B‐cell mutation rates maximize viral error catastrophes. Phys Rev Lett 88, 2002), we study the conditions under which a viral quasispecies can maximize its growth rate. We find that a virus is most viable if it generates on average precisely one mutation within the time it takes for the immune system to adapt to a new viral epitope. Experimental viral mutation rates, in particular for HIV (human immunodeficiency virus), seem to suggest that many viruses have achieved their optimal mutation rate. © 2003 Wiley Periodicals, Inc.
Stochastic modeling of fat‐tailed probabilities of foreign exchange rates
Authors: Karth Mathias , Peinke Joachim
Published: March 2003

In a recent work (Renner, C; Peinke, J.; Friedrich, R. Physica A 2001, 298, 211–217) it has been shown that the statistics of price changes on foreign‐exchange rates measured by increments can be characterized completely by a Fokker‐Planck equation. The explicit form of this Fokker‐Planck equation was deduced directly from empirical data. Here we show that this result does not hold only for one specific construction of price changes by increments but also for returns and logarithmic returns, which are commonly used to quantify fluctuations in financial time‐series over different time horizons. For all these quantities (increment and both kinds of returns) an explicit Fokker‐Planck equation is presented and a verification of the quality of this description is shown by the reproduction of fat‐tailed probability density functions for different time scales. We propose this method as a generalization of multifractal analysis. © 2003 Wiley Periodicals, Inc.
Adaptation and metalevels in a competitive game
Authors: Schuster Heinz Georg
Published: March 2003

We investigate a competitive game between two players where the player who correctly guesses the output of the other will win. By modeling the players with adaptive Booleans we show that a growing number of inputs to the Booleans provides the players with a metalevel view of the game which enables them to model their and their opponent's behavior by adaptation. Thereby the players will take turns in winning game, according to their degree of complexity. © 2003 Wiley Periodicals, Inc.
Sequence complexity in Darwinian evolution
Authors: Adami Christoph
Published: March 2003

Whether or not Darwinian evolution leads to an increase in complexity depends crucially on what we mean by the term. Physical complexity is a measure based on automata theory and information theory that turns out to be a simple and intuitive measure of the amount of information that an organism stores, in its genome, about the environment in which it evolves. It can be shown that the physical complexity of the genomes of clonal organisms must increase in evolution, if they occupy a single niche and if the environment does not change. This law of increasing complexity is a consequence of natural selection only and can be violated in co‐evolving systems as well as at high mutation rates, in sexual populations, and in time‐dependent landscapes. Yet, co‐evolution, because it can be viewed as creating an increase in physical complexity across niches, is likely the agent of a global increase in complexity. © 2003 Wiley Periodicals, Inc.
Optimization with extremal dynamics
Authors: Boettcher Stefan , Percus Allon G.
Published: March 2003

A local‐search heuristic for finding high‐quality solutions for many hard optimization problems is explored. The method is inspired by recent progress in understanding far‐from‐equilibrium phenomena in terms of self‐organized criticality, a concept introduced to describe emergent complexity in physical systems. This method, called extremal optimization, successively replaces the value of extremely undesirable variables in a sub‐optimal solution with new, random ones. Large, avalanche‐like fluctuations in the cost function emerge dynamically. These enable the search to effectively scaling barriers to explore local optima in distant neighborhoods of the configuration space while eliminating the need to tune parameters. Drawing upon models used to simulate the dynamics of granular media, evolution, or geology, extremal optimization complements approximation methods inspired by equilibrium statistical physics, such as simulated annealing. This method is very general and so far has proved competitive with—and even superior to—more elaborate general‐purpose heuristics on testbeds of constrained optimization problems with up to 105 variables, such as bipartitioning, coloring, and spin glasses. Analysis of a model problem predicts the only free parameter of the method in accordance with all experimental results. © 2003 Wiley Periodicals, Inc.
Diagnostic value of needle aspiration cytology (NAC) in the assessment of palpable inguinal lymph nodes: A study of 210 cases
Authors: Gupta Raj K. , Naran Sarla , Lallu Sharda , Fauck Robert
Published: March 2003

The aim of this study was to evaluate the diagnostic value of needle aspiration cytology (NAC) in the assessment of palpable inguinal lymph nodes, which were analyzed in 210 cases. NAC in all the cases were performed by the conventional aspiration method and cytologic examination was done on site after staining smears with the Papanicolaou method. In addition, Diff‐Quik‐stained air‐dried smears, Papanicolaou‐stained fixed smears, and filter preparations from needle washings and hematoxylin‐eosin‐stained sections of cell blocks were studied. The NAC diagnosis was supported by examining cell blocks in 92/210 cases which showed a reliable histologic architecture; further support was also obtained with a tissue biopsy in 9/12 cases of inflammatory lesions, 7/7 cases with a suspicious diagnosis, 20/26 cases of melanomas, 15/15 cases of lymphomas, and/or a comparison with the primary tumor in other cases of metastatic tumors. Additionally, immunoperoxidase and/or histochemical stains were done. Twelve cases were diagnosed as inflammatory lesions and 88 cases were regarded as negative (normal cellular elements n = 40; reactive elements n = 48). In 58 cases a variety of metastatic tumors were diagnosed (melanoma n = 26; others n = 32) and in 15 cases a diagnosis of lymphoma was made. Seven cases were diagnosed as suspicious of malignancy and 30 cases were unsatisfactory due to scanty/acellular samples (despite 2–3 repeat samplings). However, in five of these malignant tumors were later found on a biopsy which was done due to a persistent and continued enlargement of lymph node(s). The sensitivity was 91.7%, specificity 98.2%, positive predictive value (PPV) 97.7.%, and negative predictive value (NPV) was 95.45%. Based on our study we feel that NAC as a first line of investigation is not only useful in the diagnosis of lesions in inguinal lymph nodes, but can also help in deciding on an appropriate management. Also, histologic architecture from cell blocks can be correlated with cytology and such material can be used for histochemical and immunomarker studies. Diagn. Cytopathol. 2003;28:175–180. © 2003 Wiley‐Liss, Inc.
Cytologic diagnosis of low‐grade papillary urothelial neoplasms (low malignant potential and low‐grade carcinoma) in the context of the 1998 WHO/ISUP classification
Authors: Whisnant Richard E. , Bastacky Sheldon I. , Ohori N. Paul
Published: March 2003

The 1998 World Health Organization/International Society of Urological Pathology (WHO/ISUP) classification of urothelial neoplasms introduced a category called papillary neoplasm of low malignant potential (LMP) and separated it from low‐grade papillary urothelial carcinoma (LGPUC), which was thought to yield abnormal cells in cytology specimens. The objective of our study was to evaluate the effectiveness of urine cytology in diagnosing these lesions. Eighty‐six paired transurethral surgical biopsy and corresponding urine cytology specimens representing the spectrum of urothelial papillary lesions were examined. Consensus diagnosis on each biopsy was made, and the distribution was as follows: 16 benign urothelium, 27 LMP, 28 LGPUC, and 15 high‐grade papillary urothelial carcinoma (HGPUC). This was followed by a blinded independent review of the urine cytology specimens by three observers. Each cytology case was marked as negative, atypical, suspicious, or positive for malignant cells by using previously published cytologic criteria. When the negative and atypical diagnoses were grouped together as “benign” and the suspicious and malignant diagnoses as “malignant,” the detection rate of “malignancy” of the lesions was as follows: LMP, 37%; LGPUC, 25%; and HGPUC, 53%. The false positive rate was 6%, and the positive predictive value (PPV) was 94%. Detection rates of cells that were at least “atypical” were as follows: LMP, 74%; LGPUC, 79%; and HGPUC, 100%. While most of the LMP and LGPUC cases yielded cells that were at least “atypical,” there was no significant difference in the distribution of cytologic diagnoses for LMP and LGPUC cases (P > 0.05). Urine cytology in the context of the 1998 WHO/ISUP classification appears to be useful as a screening tool but does not appear to discriminate LMP effectively from LGPUC. Diagn. Cytopathol. 2003;28:186–190. © 2003 Wiley‐Liss, Inc.
Cytodiagnosis of primary lymphoma of bone on fine‐needle aspiration cytology specimens: Review of 25 cases
Authors: Lin Fan , Staerkel Gregg , Fanning Tina V.
Published: March 2003

Diagnosis of nodal lymphomas on fine‐needle aspiration (FNA) cytologic specimens has been well established. However, cytodiagnosis of primary lymphoma of bone has not been well documented because of its rarity. We undertook a retrospective study of 25 cases of FNA cytologic specimens of primary lymphoma of bone. The slides were available for review in 20 cases; each case was evaluated with 15 cytologic features in conjunction with immunophenotyping and available surgical materials. Three diagnostic categories were assigned, including nondiagnostic (4/16%), suspicious (3/12%), and malignant (18/72%). Among the 18 malignant lymphoma, all were diagnosed on the basis of cytologic materials together with immunocytochemistry, except that two cases also relied on the cell blocks. The nondiagnostic and suspicious cases were subsequently confirmed to be malignant lymphoma on the surgical core biopsies. Of the 25 cases, 23 cases were large B‐cell lymphoma, one follicular lymphoma large cell type, and one small lymphocytic lymphoma. False‐positive or false‐negative cases were not present in this study series. In conclusion, the vast majority of primary lymphoma of bone can be accurately diagnosed and classified on FNA cytologic specimens in conjunction with immunocytochemistry. The nondiagnostic and suspicious categories can be further reduced or eliminated by improving FNA techniques or by recommendation of surgical core biopsies together with other techniques such as flow cytometry and molecular analysis. Diagn. Cytopathol. 2003;28:205–211. © 2003 Wiley‐Liss, Inc.
Nested reciprocities: The organism–environment system in perception–action and development
Authors: Wagman Jeffrey B. , Miller David B.
Published: March 2003

The ecological approach to studying perception and action is one in which researchers view the structure in ambient energy arrays surrounding a given organism as being sufficient to specify meaningful environmental properties to that organism. Thus, from this perspective, perception is viewed not as a cognitive achievement but as a lawful state of affairs that exists in an organism–environment system. The approach to studying development known as transactionalism is one in which researchers view the developmental process as the expression of a complex web of endogenous and exogenous factors. Thus, from this perspective, development is not an unfolding of a genetic program, but rather an ongoing exchange among levels of the organism–environment system that continues throughout the life span of the organism. Despite their independent development, these two meta‐theoretical approaches have much in common. In each approach, the organism–environment system is the fundamental unit of analysis, and the development of perception and behavior is spread across the multiple levels of this system. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 42: 317–334, 2003.
Stable operation region and dynamic behavior of Ar pulse‐modulated induction thermal plasma with different molecular gases
Authors: Tanaka Yasunori , Sakuta Tadahiro
Published: March 2003

The pulse‐modulated induction thermal plasma (PMITP) was established in Ar gas with additional gases such as H2, O2, N2, and CO2 to investigate the effects of various gas inclusions on the transient characteristics of thermal plasma. The dynamic response times of the thermal plasmas were estimated from the measured time‐varying radiation intensity of Ar spectral line. Furthermore, time evolution of the Ar excitation temperature was determined by the two‐line method. The results indicated that especially in Ar‐CO2 PMITP, decreasing the current level in a modulation cycle raised the on‐delay time which means a recovery time from a low‐temperature state to a high‐temperature one. In addition, the inclusion of CO2 in Ar PMITP caused lower temperatures just before the on‐operation compared with other gases used in the experiment. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 143(4): 1–11, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10144
Structure‐function studies of the C3a‐receptor: C‐terminal serine and threonine residues which influence receptor internalization and signaling
Authors: Settmacher Britta , Rheinheimer Claudia , Hamacher Henning , Ames Robert S. , Wise Alan , Jenkinson Lesley , Bock Daniel , Schaefer Myriam , Köhl Jörg , Klos Andreas
Published: March 2003

The anaphylatoxic peptide C3a is a pro‐inflammatory mediator generated during complement activation, whose specific G protein coupled receptor is expressed on granulocytes, monocytes, mast cells, activated lymphocytes, and in the nervous tissue. We have generated RBL‐2H3 cell clones stably expressing mutants of the human C3a‐receptor (C3aR) with combined alanine (Ala) substitutions of ten C‐terminal serine (Ser) or threonine (Thr) residues, which may represent putative phosphorylation sites to characterize their role in ligand‐induced C3aR internalization and signaling. Ser475/479 and Thr480/481 as well as Ser449 seemed not to be involved in ligand‐induced receptor internalization. Either directly or by a conformational change they even "inhibit" C3aR internalization. In contrast, mutants with Ala substitutions at Ser465/470 and Thr463/466 were poorly internalized, and Thr463 seemed to be the most important C‐terminal Thr or Ser residue directly effecting receptor internalization. However, it is likely that other C3aR regions additionally participate in this negative feed‐back mechanism since even mutants with multiple Ala substitutions still internalized to a limited degree. Interestingly, in a mutant with a single exchange of Ser449 to Ala, the signal transduction assessed by a Ca2+ assay and [35S]GTPγS‐binding on HEK cells transiently co‐transfected with G‐alpha 16 or G‐alpha O, respectively, was severely impaired, indicating that this residue of C3aR is involved in G protein coupling.
Differences in outcome of the interaction between Cryptococcus neoformans glucuronoxylomannan and human monocytes and neutrophils
Authors: Monari Claudia , Retini Cinzia , Casadevall Arturo , Netski Dale , Bistoni Francesco , Kozel Thomas R. , Vecchiarelli Anna
Published: March 2003

Disseminated infections by the opportunistic yeast Cryptococcus neoformans are characterized by accumulation in tissues of glucuronoxylomannan (GXM), the major component of the capsular polysaccharide. We investigated binding, uptake, and disposal of GXM by peripheral blood neutrophils and monocytes, and the effect of GXM uptake on phagocytic cell function. GXM was efficiently bound and internalized by both types of phagocytic cells, with maximal loading at 50 μg/ml, a GXM concentration found in serum and cerebrospinal fluid of some cryptococcosis patients. However, substantial differences were noted in the kinetics for uptake by macrophages and neutrophils. Whereas neutrophils rapidly ingested limited amounts of GXM and then expelled or degraded it after 1 h of incubation, macrophages demonstrated continuous intracellular accumulation for up to 1 week of incubation. Accumulation of GXM by neutrophils was accompanied by reduced anticryptococcal activity, suggesting one more mechanism for virulence enhancement by the major capsular component of C. neoformans.
Sequential conversion of the redox status of macrophages dictates the pathological progression of autoimmune diabetes
Authors: Murata Yukie , Amao Michiko , Hamuro Junji
Published: March 2003

The redox status of macrophages (Mϕ), indexed by intracellular content of glutathione (icGSH), varies sequentially along with disease progression in nonobese diabetic mice. At the stage ofearly insulitis, Mϕ skew to oxidative Mϕ (OMϕ) with decreased icGSH, then to reductive Mϕ (RMϕ) with elevated icGSH and to OMϕ after the occurrence of diabetes. RMϕ or OMϕ inducing agents either delayed or accelerated the onset of diabetes in a mutually inverse manner. RMϕ or OMϕ adoptively transferred exacerbated or ameliorated the disease progression depending on the redox status of Mϕ of recipient mice. The new paradigm that the sequential conversion of redox status of Mϕ dictates the pathological progression may provide a new insight on the mechanism underlying autoimmune diabetes.
The neutrophil‐activating protein of Helicobacter pylori (HP‐NAP) activates the MAPK pathway in human neutrophils
Authors: Nishioka Hiroaki , Baesso Ilenia , Semenzato Gianpietro , Trentin Livio , Rappuoli Rino , Giudice Giuseppe Del , Montecucco Cesare
Published: March 2003

Infection by Helicobacter pylori causes an acute inflammatory response followed by a chronic infection of the human gastric mucosa characterized by the infiltration of neutrophils andmononuclear inflammatory cells. The neutrophil‐activating protein of Helicobacter pylori (HP‐NAP) is a virulence factor that activates neutrophils, monocytes, and mast cells. However, the mechanism by which HP‐NAP activates these cells is not fully understood. Here, we show that HP‐NAP induces extracellular regulated kinase (ERK) and p38‐mitogen‐activated protein kinase (MAPK) activation in human neutrophils; c‐Jun N‐terminal kinase is not activated by HP‐NAP. A MAPK/ERK kinase inhibitor and a p38‐MAPK inhibitor suppress HP‐NAP‐mediated neutrophil oxidative burst, adhesion, andchemotaxis, but not actin polymerization. Pertussis toxin (PTX) inhibits all these neutrophil functions and the MAPK activation caused by HP‐NAP. These results demonstrate that HP‐NAP activates neutrophils through a PTX‐sensitive pathway and that ERK and p38‐MAPK are involved in many neutrophil functions stimulated by HP‐NAP.
Interleukin‐2 primes eosinophil degranulation in hypereosinophilia and Wells' syndrome
Authors: Simon Hans‐Uwe , Plötz Sabine , Simon Dagmar , Seitzer Ulrike , Braathen Lasse R. , Menz Günter , Straumann Alex , Dummer Reinhard , Levi‐Schaffer Francesca
Published: March 2003

Patients with hypereosinophilia frequently suffer from eosinophil‐mediated damages of the heart, lungs, skin, and other organs, while some do not. The reason(s) for this difference is not known. We observed that eosinophils from most patients with hypereosinophilia express the α‐chain of the IL‐2 receptor (CD25), and that IL‐2 enhances platelet‐activating factor‐stimulated release ofeosinophil cationic protein from CD25‐expressing but not from CD25‐negative eosinophils. Such a "priming" effect has previously been described for eosinophil hematopoietins. These data suggest thatpatients with increased eosinophil surface CD25 expression are at higher risk of eosinophil degranulation and subsequent tissue damage when IL‐2 is present at inflammatory sites.