bluuebunny/crossref_metadata_2025 huggingface dataset:
Localization and Pattern Formation in BBGKY Hierarchy
Authors: Fedorova Antonina N. , Zeitlin Michael G.
Published: December 2004

A fast and efficient numerical‐analytical approach is proposed for modeling complex behaviour in the BBGKY hierarchy of kinetic equations. Numerical modeling shows the creation of various internal structures from localized modes, which are related to the localized or chaotic type of behaviour and the corresponding patterns (waveletons) formation. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Steady Groundwater Flow with Steep Gradients: An Analytic Approach to the 2D–Problem with a Vertical Pressure Boundary Condition and Steady Recharge/Drainage
Authors: Fröhner Anja , Edenhofer Johann , Schmitz Gerd H.
Published: December 2004

Steady groundwater flow with steep gradients in a vertical plane due to superficial recharge/drainage, inner sources/sinks and a one‐sided pressure boundary condition can be described by a 2D Poisson equation with a nonlinear free surface boundary condition. By means of conformal mapping techniques Schmitz and Edenhofer [1] derived the exact explicit solution of this problem in a horizontally infinite aquifer. Their results are extended to problems with a one‐sided vertical pressure boundary condition, modelling f. ex. the boundary between an aquifer and an adjacent free water body. According to ist simple parametrization, this approach can be applied on one hand to model various real world phenomena like river–aquifer–systems. It may on the other hand serve as a tool for investigating the exactness of numerical solutions and the range of validity of simplifying assumptions. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Local existence of the solution to the initial‐boundary value problem in nonlinear thermomicroelasticity theory
Authors: Gawinecki Jerzy , Łazuka Jarosław
Published: December 2004

We prove a theorem about local existence (in time) of the solution to the first initial‐boundary value problem for a nonlinear system of equation of the thermomicroelasticity theory. At first, we prove existence, uniqueness and regularity of the solution to this problem for the associated linearized system by using the method of semi‐group theory. Next, basing on this theorem, we prove an energy estimate for the solution to the linearized system by applying the method of Sobolev space. At the end, using the Banach fixed point theorem, we prove that the solution of our nonlinear problem exists and is unique. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On a Model for Fires in Tunnel Network Structures
Authors: Kraft Marcus , Gasser Ingenuin
Published: December 2004

A one dimensional model to describe the dynamics of tunnelfires is used to model tunnel network structures. The corresponding conditions at the nodes are formulated. A numerical methods is presented. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Drobot's algebraic theory of dimensional analysis in construction of system of mechanoelectric analogies. Application to the problems of acoustoelectric waves propagation in porous long bones
Authors: Uklejewski R. , Czapski T.
Published: December 2004

Basing on the algebraic theory of dimensional analysis given by S. Drobot [3] and extended by A. Muciek [4], the definition of a system of mechano–electric analogies has been proposed as an isomorphism of dimensional subspaces: of all the mechanic quantities Πm and of all the electric quantities Πe. The method of construction of systems electromechanical analogies has been given and applied to the problems of acousto–electric waves propagation in porous long bones in order to derive an unified method of analysis of these problems by means of the methods used in the electric transmission line theory. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Binary Mixtures in Bayesian Treatment
Authors: Boese F. G.
Published: December 2004

In the Bayesian treatment of binary statistical mixture distributions, also an integration with respect to the mixture parameter is to be carried out. An exact integral evaluation is devised to effectuate this integration fast and numerically stable. On an astronomical application to Bayesian source detection in x‐ray photon data from the ROSAT all–sky survey is reported. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reliability of Elastic‐Plastic Frame Structures
Authors: Sieniawska Roza , Wysocka Alina , Zukowski Stanislaw
Published: December 2004

An effective algorithm for estimating the reliability of frame structures made of an elastic perfectly plastic material is presented. It is assumed that the structure is working in uniaxial state of stress, the material parameters and the limit values of the loads are described by random variables, all loads are acting in a static manner, the probability density functions of all random variables, which describe the structure and loads are known. As the structure reliability measure the probability of failure and corresponding reliability index are regarded. The dead (constant) load and the climatic loads are taken into account. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling and Optimization of Interference Limited Wireless Communications
Authors: Irmer Ralf , Fischer Andreas
Published: December 2004

Multiple access interference (MAI) limits the system capacity of wireless communications systems applying code division multiple access (CDMA). Provided that channel knowledge is available in the transmitter, the transmitted signal can be preprocessed by multiuser transmission (MUT) methods. As optimization criterion, the bit error probability/rate (BER) is chosen. On the transmit signal, a limited power constraint is imposed, which is a quadratic function of the transmit signal. The nonlinear optimization problem is modeled in this paper. Unfortunately, the problem is non‐convex. However, with iterative nonlinear optimization methods like SQP, local minima can be found with a performance outperforming other MUT methods.

The main remaining challenge are low‐complexity optimization algorithms to allow for a real‐time implementation in highdata rate wireless communications. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Second‐order sufficient optimality conditions for the optimal control of instationary Navier‐Stokes equations
Authors: Tröltzsch Fredi , Wachsmuth Daniel
Published: December 2004

In this article sufficient optimality conditions are established for optimal control of evolutionary Navier‐Stokes equations. The second‐order condition requires coercivity of the Lagrange function on a suitable subspace together with first‐order necessary conditions. It ensures local optimality of a reference function in a Ls‐neighborhood, whereby the underlying analysis allows to use weaker norms than L∞. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prenatal sonographic delineation of the complex cardiac anatomy of thoraco‐omphalopagus twins
Authors: Tongsong T. , Khunamornpong S. , Piyamongkol W. , Chanprapaph P.
Published: December 2004

We describe a case of thoraco‐omphalopagus twins diagnosed at 18 weeks' gestation. Each twin had a separate set of anatomical structures except for a shared heart, upper liver and anterior chest wall. The heart was located at the center of the juncture, and consisted of three atria and two ventricles, each twin having a single ventricle and right atrium but a fused left atrium. A set of great arteries originated from each single ventricle and there was juxtaposition of the aortic and pulmonary valves. One twin had transposition of the great arteries, whereas in the other these were normal in configuration. There was only one umbilical cord which contained four vessels (two arteries and two veins). This case report demonstrates the possibility of using fetal echocardiography to delineate the cardiovascular complex of the conjoined heart. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Cardiac Rehabilitation Reduces the Rate of Major Adverse Cardiac Events after Percutaneous Coronary Intervention
Authors: Dendale Paul , Berger Jan , Hansen Dominique , Vaes Johan , Benit Edouard , Weymans Maria
Published: December 2004

Background: Despite multiple publications on effects of rehabilitation in cardiac patients, rehabilitation is not fully known to be of value in post-percutaneous coronary intervention (PCI) patients.

Aims: To investigate the influence of cardiac rehabilitation on the incidence of major adverse cardiac events (MACEs) in post-PCI patients.

Methods: Retrospectively and nonrandomized 140 post-PCI patients (107 males, mean age 62 (7) years) participated in a 3-month rehabilitation program, starting 2 weeks post-PCI, while 83 post-PCI patients (54 males, mean age 68 (8) years) did not and were all followed up for 15 months. Data on cardiac medication prescription and incidence of MACE (including angina pectoris with or without reintervention, restenosis, myocardial infarction, revascularisation with re-PCI or CABG, and death) were collected. The relationship with cardiovascular risk factors including sex, smoking behaviour, obesity, diabetes mellitus, hypertension, familiar predisposition, and hypercholesterolemia was analysed.

Results: The incidence of total MACE in the rehabilitation group is significantly lower than in the control group (24% vs. 42%, respectively; P<0.005). The incidence of documented restenosis, angina pectoris with resulting reintervention, all revascularisations, and death is significantly lower in the rehabilitation group, compared with the control group.

Conclusion: The incidence of MACE and restenosis is significantly lower when PCI patients are included in a cardiac rehabilitation program.
Origin recognition and the chromosome cycle
Authors: Stillman Bruce
Published: December 2004

Prior to the initiation of DNA replication, chromosomes must establish a biochemical mark that permits the recruitment in S phase of the DNA replication machinery that copies DNA. The process of chromosome replication in eukaryotes also must be coordinated with segregation of the duplicated chromosomes to daughter cells during mitosis. Protein complexes that utilize ATP coordinate events at origins of DNA replication and later they participate in the initiation of DNA replication. In eukaryotes, some of these proteins also play a part in later processes that ensure accurate inheritance of chromosomes in mitosis, including spindle attachment of chromosomes, accurate duplication of centrosomes and cytokinesis. A perspective of how ATP‐dependent proteins accomplish this task in eukaryotes is discussed.
Three autism candidate genes: a synthesis of human genetic analysis with other disciplines
Authors: Bartlett Christopher W. , Gharani Neda , Millonig James H. , Brzustowicz Linda M.
Published: December 2004

Autism is a particularly complex disorder when considered from virtually any methodological framework, including the perspective of human genetics. We first present a review of the genetic analysis principles relevant for discussing autism genetics research. From this body of work we highlight results from three candidate genes, REELIN (RELN), SEROTONIN TRANSPORTER (5HTT), and ENGRAILED 2 (EN2) and discuss the relevant neuroscience, molecular genetics, and statistical results that suggest involvement of these genes in autism susceptibility. As will be shown, the statistical results from genetic analysis, when considered alone, are in apparent conflict across research groups. We use these three candidate genes to illustrate different problems in synthesizing results from non‐overlapping research groups examining the same problem.

However, when basic genetic principles and results from other scientific disciplines are incorporated into a unified theoretical framework, at least some of the difficulties with interpreting results can be understood and potentially overcome as more data becomes available to the field of autism research. Integrating results from several scientific frameworks provides new hypotheses and alternative data collection strategies for future work.
Increase of pullout strength of spinal pedicle screws with conical core: Biomechanical tests and finite element analyses
Authors: Hsu Ching‐Chi , Chao Ching‐Kong , Wang Jaw‐Lin , Hou Sheng‐Mou , Tsai Ying‐Tsung , Lin Jinn
Published: December 2004

Screw loosening can threaten pedicle screw fixation of the spine. Conical screws can improve the bending strength, but studies of their pullout strength as compared with that of cylindrical screws have shown wide variation. In the present study, polyurethane foam with two different densities (0.32 and 0.16 gm/cm3) was used to compare the pullout strength and stripping torque among three kinds of pedicle screws with different degrees of core tapering. Three‐dimensional finite element models were also developed to compare the structural performance of these screws and to predict their pullout strength. In the mechanical tests, pullout strength was consistently higher in the higher density foam and was closely related to screw insertion torque (r = 0.87 and 0.81 for the high and low density foam, respectively) and stripping torque (r = 0.92 and 0.78, respectively). Conical core screws with effective foam compaction had significantly higher pullout strength and insertion torque than cylindrical core screws (p < 0.05). The results of finite element analyses were closely related to those of the mechanical tests in both situations with or without foam compaction. This study led to three conclusions: polyurethane foam bone yielded consistent experimental results; screws with a conical core could significantly increase pullout strength and insertion torque over cylindrical; and finite element models could reliably reflect the results of mechanical tests. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Coffeehouses, Guilds and Oriental Despotism. Government and Civil Society in Late 17th to Early 18th Century Istanbul and Isfahan, and as seen from Paris and London
Authors: ARJOMAND SAÏD AMIR
Published: December 2004

Montesquieu popularized the notion of Oriental Despotism as the type of government pertaining to a lawless society based on the equality of subjects in fear and powerlessness. It typified Europe's Other in the age of absolutism. This essay does not examine the idea of total despotic power directly but rather the assumption of the absence of law and its guarantee of a sphere of civil autonomy and agency which will anachronistically be called “civil society”. While substantiating the emergence of a public sphere around coffeehouses, the growth of guilds on the basis of customary law and the development of educational and philanthropic endowments on the basis of the law of waqf, we also take the opportunity to compare the civic and educational institutions of the Ottoman and Safavid empires in the 17th and early 18th centuries.
Madwomen in the Drawing-Room: Female Invalidism in Ellen Glasgow's Gothic Stories
Authors: DOMÍNGUEZ-RUÉ EMMA
Published: December 2004

“Definitions belong to the definers, not the defined.” Toni Morrison, Beloved.

Freud's psychoanalytic theories of fear of castration and penis-envy transformed woman into not-man, thus defining her as “other” and “lacking.” His studies also gave a sexual component to relationships among women, marking them as potentially lesbian and hence deviant. Medical men of Victorian England and America consciously or unconsciously helped to justify gender roles and women's seclusion in the domestic on the grounds that their specific physiology made them slaves of their reproductive system. As women's ovaries presumably controlled their lives and their behavior, genitals determined social roles, and doctors urged mothers to remind their daughters that any deviation from their “natural” and legitimate functions as wives and mothers could ruin their health forever. The cult of True Womanhood conveniently idealized maternity and defined the virtues of obedience, piety, and passivity as essentially feminine, while it condemned the desire for an education or the practice of birth control as unnatural and dangerous to women and to the whole of society. In the last decades of the nineteenth century, hysteria became the most fashionable of the so-called “female maladies” among middle- and upper-class women, a fact that illustrates how physicians failed to dissociate scientific evidence from social views of the period. Victorian psychologists and gynecologists mimicked contemporary male attitudes, which sanctioned the doctrine of separate spheres, while affectionate bonds between women were regarded with suspicion, as they could lead to homosexuality.
The Geography of Law Enforcement Malpractice: National Patterns of Official Misconduct in the United States, 1989–1999
Authors: LOPEZ JOSE JAVIER , THOMAS PEDRO M.
Published: December 2004

One of the darkest aspects of U.S. history and culture is encapsulated in crime perpetrated by law enforcement officials. In fact, police abuse of power has long been a footnote in analyses of governments' monopoly on legitimated violence. The history of modern policing itself indicates long-standing concern with excessive, sometimes brutal, control over citizens by law enforcement agents. Such concerns have been articulated variously over time by the public, academics, the press, and within law enforcement ranks. Much of this concern turns on perception, for police malfeasance is notoriously shrouded behind a “blue wall,” well-meaning law enforcement officials are genuinely interested in public perceptions of their services, and news of police malpractice flares selectively and variously across time.
Wilful ignorance: the struggle to convince the free trade skeptics
Authors: KRUEGER ANNE O.
Published: December 2004

Good evening. I am delighted to be back here this evening among so many oldfriends.
The trade environment and small countries
Authors: DOWNES ANDREW S.
Published: December 2004

With rapid changes taking place in the global trading environment, there has been concern within several international arenas and academia about the future of small developing countries (SDCs). Although the discussion relating to the effects of country size on economic growth and development began in the early 1960s with the publication of Kuznets' (1960) article and Demas' (1965) monograph, there has been a recent flurry of writings on small developing countries in the context of the new global order. For example, the World Bank in collaboration with the Commonwealth Secretariat (2000) undertook a major study of small states and their ability to meet the challenges of a changing global economic environment. Kennes (2000) and Salvatore et al. (2001) have also analyzed the challenges and opportunities facing small countries in the global marketplace. The Commonwealth Secretariat had previously arranged two expert panels to examine the vulnerability of small states in a global society and also the future of small states in overcoming their vulnerability (see Commonwealth Secretariat, 1985, 1997).
Is small really so ugly?
Authors: SPOLAORE ENRICO
Published: December 2004

The number of sovereign states has steadily increased over the past few decades and is rapidly approaching two hundred. Many of these countries are small. The median country size in terms of population is around five million people. Tuvalu, the smallest state with a seat at the United Nations, has 11,000 people. The smallest country in the sample studied by Winters and Martins (W&M) is Niue, a self-governing country in free association with New Zealand, with only 2,000 inhabitants.
Chile – price band system and safeguard measures relating to certain agricultural products
Authors: BAGWELL KYLE , SYKES ALAN O.
Published: December 2004

This paper addresses the dispute brought to the World Trade Organization (WTO) by Argentina concerning certain Chilean measures affecting the importation of wheat, wheat flour, oil seeds, edible vegetable oils and sugar. The complaint by Argentina challenged two types of policies – a ‘price band system’ that was applicable to four of those product categories, and safeguard measures that were applicable to three of them. The WTO panel ruled in favor of Argentina on both sets of measures. It found that the price band system violated Article IV of the Agriculture Agreement and Article II of GATT 1994. The safeguard measures, according to the panel, violated various provisions of the Safeguards Agreement, as well as Article XIX of GATT 1994. Chile elected not to appeal the panel ruling regarding the safeguard measures, but did appeal the adverse finding as to the price band system. The Appellate Body subsequently affirmed in substantial part the finding that the price band system violated Article 4 of the Agriculture Agreement, but reversed the finding of a violation under Article II of GATT 1994. Chile has since indicated an intention to comply with the ruling, and an arbitration pursuant to Article 21.3 of the DSU determined that the reasonable period of time for compliance would expire on December 23, 2003.
Reply to the commentators
Authors: MATTOO AADITYA , SUBRAMANIAN ARVIND
Published: December 2004

We are grateful to the commentators for their valuable observations. We cannot do justice to the full range of comments we have received. Below we respond briefly to some of the issues raised.
Effekte von L-Dopa auf die Speicherung und den Abruf verbaler Informationen bei Schlaganfallpatienten
Authors: Golz D. , Erdfelder E.
Published: December 2004

Zusammenfassung: In einer Doppel-Blind-Studie wurde geprüft, ob das katecholaminerg stimulierende Medikament L-Dopa die Gedächtnisleistungen von Schlaganfallpatienten steigern kann. 37 Patienten wurden zur On-Time und Off-Time des Medikaments einer neuropsychologischen Untersuchung unterzogen. Mittels Varianzanalysen konnte gezeigt werden, dass L-Dopa die verbalen episodischen Gedächtnisleistungen verbessern kann, und zwar offenbar speziell die Reproduktion und weniger die Rekognition von Informationen. Analysen auf der Grundlage des Speicherungs-Abruf-Modells von Batchelder und Riefer (1980 , 1986 ) demonstrierten darüber hinaus, dass eher die itemspezifische als die semantisch-relationale Verarbeitung von Itemgruppen profitiert. Eine Steigerung der Aufmerksamkeitsleistung im Sinne der “Alertness” konnte nicht ausgemacht werden, ebenso wenig ein bedeutsamer Zusammenhang von Aufmerksamkeits- und Gedächtnisleistungen. Die Ergebnisse können zusammenfassend dahingehend interpretiert werden, dass insbesondere der Abruf itemspezifischer Informationen durch L-Dopa selektiv gefördert werden kann. Die mögliche vermittelnde Rolle des Neurotransmitters Noradrenalin wird diskutiert.
Eine Kurzform des Hooper Visual Organization Test
Authors: Merten Thomas
Published: December 2004

Zusammenfassung: Testprotokolle einer auf der Basis empirischer Analysen entwickelten Kurzform des Hooper Visual Organization Test (VOT) lagen für 292 neurologische Patienten einer Akutklinik vor. Es wurden die neuropsychologischen Untersuchungsergebnisse von jenen 200 Patienten ausgewählt, die vollständige Datensätze in einer Minimalbatterie aufwiesen, sodass eine Hauptachsenanalyse mit schiefwinkliger Rotation durchgeführt werden konnte. Der VOT lädt ebenso wie der Mosaik-Test des HAWIE-R, der Trail Making Test (TMT), die Alertness-Reaktion sowie unspezifische Screening-Instrumente auf einem varianzstarken Faktor, der als “globale” oder “nicht-sprachliche kognitive Fähigkeiten” interpretiert wurde. Zwei weitere Faktoren lassen sich als “verbales Gedächtnis” und “Arbeitsgedächtnis/Gedächtnisspanne” benennen. Die höchsten Rangkorrelationen weist die Kurzform mit dem TMT-B sowie mit dem Mosaik-Test des HAWIE-R auf (jeweils 0.68). Die 7-Tage-Retest-Reliabilität wurde anhand einer Teilstichprobe von 36 Patienten auf 0.93 geschätzt, bei einem Anstieg der Testwerte von der Erst- zur Zweitmessung um 1.1 Punkte. Bei einem Vergleich von Patienten mit lateralisierten zerebralen Läsionen wurde ein signifikant niedrigerer Wert für die Patienten mit rechts- gegenüber denen mit linkshemisphärischer Beeinträchtigung gefunden. Insgesamt korrespondieren diese Ergebnisse gut mit denen, die in der Literatur für die Originalform des VOT dokumentiert sind.
A self‐consistent model of plasma and neutrals at Saturn: The ion tori
Authors: Richardson J. D. , Jurac S.
Published: December 2004

We self‐consistently solve models for the plasma transport and chemistry and the neutral density. These models yield a plasma composition in Saturn's magnetosphere which is consistent with the high neutral densities known to be present. We find that the molecular ions OH+ and H2O+ make up over 80% of the ion density, with more H2O+ than OH+ inside 6 RS and equal amounts of OH+ and H2O+ outside 6 RS. These predictions will be directly tested by Cassini in the near future.
Turbulent structure of high‐density suspensions formed under waves
Authors: Lamb Michael P. , D'Asaro Eric , Parsons Jeffrey D.
Published: December 2004

We performed a series of laboratory experiments on the interactions between turbulent wave boundary layers and a predominantly silt‐sized sediment bed. Under a wide range of wave conditions similar to those observed on storm‐dominated midshelf environments we produced quasi‐steady high‐density benthic suspensions. These suspensions were turbulent, while containing large near‐bed concentrations of suspended sediment (17–80 g/L), and were separated from the upper water column by a lutocline. Detailed measurements of the vertical structure of velocity, turbulence, and sediment concentration revealed that the wave boundary layer, while typically >1 cm thick in sediment‐free conditions, was reduced substantially in size, often to <3 mm, with the addition of suspendible sediment. This likely resulted from sediment‐induced stratification that limited vertical mixing of momentum. Despite boundary layer reduction the flows were able to support high‐density suspensions as thick as 8 cm because turbulent energy was transported upward from this thin but highly energetic near‐bed region. Standard formulations of the Richardson number for shear flows are not applicable to our experiments since the suspensions were supported from transported rather than locally produced turbulence.
The allelic loss of chromosome 3p25 with c‐myc gain is related to the development of clear‐cell renal cell carcinoma
Authors: Yamaguchi S , Yoshihiro S , Matsuyama H , Nagao K , Fukunaga K , Matsumoto H , Matsuda K , Oba K , Naito K
Published: December 2004

To explore the role of allelic losses at 3p25 and genetic alterations of chromosome 8, we investigated the relationships between genetic alterations in these chromosomal regions and clinicopathologic findings (such as tumor size and grade), by employing fluorescence in situ hybridization (FISH). Fifty Japanese clear‐cell renal cell carcinomas (RCCs) were examined by dual‐color FISH using cosmid DNA probes for 3p25.1–25.3 combined with probes for chromosome 3 centromere, 8p12, 8p21.1, 8p21.3, 8p22 and 8q24.12–24.13 (c‐myc), and chromosome 8 centromere. Deletion at 3p25.1–25.3 was detected in 38 patients (76%), while 8p12 deletion, 8p21.1 deletion, 8p21.3 deletion, 8p22 deletion and c‐myc gain were detected in 23 (46%), 25 (50%), 25 (50%), 25 (50%), and 20 patients (40%), respectively. There was a significant correlation between 8p21.1 deletion, 8p21.3 deletion and 8p21.1 deletion with c‐myc gain and tumor grade (p = 0.04, 0.04 and 0.02, respectively). Deletions at 8p21.1 and 8p21.3 with 3p deletion were significantly related to tumor grade; the statistical significance was identical to that of sole 8p deletion with tumor grade. The deletion at 3p25.1–25.3 with c‐myc gain showed a significant correlation with tumor size, indicating an association with tumor progression. Our results suggest that the allelic loss of chromosome 3p25 with c‐myc gain is related to the development of clear‐cell RCC.
Updated investigations of the role of methylenetetrahydrofolate reductase in human neural tube defects
Authors: Rampersaud E , Melvin EC , Siegel D , Mehltretter L , Dickerson ME , George TM , Enterline D , Nye JS , Speer MC ,   the NTD Collaborative Group
Published: December 2004

Folate supplementation appears to reduce the risk for neural tube defects (NTDs). Methylenetetrahydrofolate reductase (MTHFR) is a candidate gene in the folate metabolism pathway that has been extensively studied in different human populations. We examined the risk associated with having the thermolabile variant (TT) of MTHFR in a study of 175 American Caucasians with NTDs and their families. We found a significant association in patients compared with 195 unrelated controls [odds ratio (OR) = 2.13, 95% confidence interval (95% CI) = 1.11–4.09)], but not in mothers (OR = 1.29, 95% CI = 0.622–2.67) or in fathers (OR = 1.45, 95% CI = 0.681–3.09). We found no evidence for unequal transmission from parents to an affected child (p > 0.10). We failed to find a previously reported association for a combined haplotype for MTHFR and cystathionine β‐synthase, except in subjects with NTDs compared with 559 pooled controls (OR = 2.87, 95% CI = 1.03–8.03). We found no evidence for an association for a novel CA‐repeat polymorphism identified in a gene closely linked to MTHFR (p > 0.10). Our studies continue to suggest that additional candidate genes other than MTHFR may be responsible for an increased risk to NTD in some American Caucasian families.
Segregation of the V804L mutation and S836S polymorphism of exon 14 of the RET gene in an extended kindred with familial medullary thyroid cancer
Authors: Patócs A , Valkusz Z , Igaz P , Balogh K , Tóth M , Varga I , Rácz K
Published: December 2004

In multiple endocrine neoplasia type 2A (MEN 2A) and familial medullary thyroid cancer (FMTC), the majority of germline mutations are restricted to specific positions in exons 10 and 11 of the RET gene. However, germline mutations may very occasionally occur in other exons, including exon 14 of the RET gene. Interestingly, an increased frequency of a rare germline sequence variant of the RET exon 14, S836S, has been detected in patients with sporadic medullary thyroid cancer (MTC), and this variant has been proposed to play a role in the genesis of MTC and, perhaps, FMTC. In this study we report the segregation of a germline V804L mutation and a germline sequence variant S836S in exon 14 of the RET gene in an extended Hungarian FMTC kindred comprising 80 individuals of four generations. Molecular analysis of the RET gene was performed by direct DNA sequencing in 23 family members, of whom 12 had the V804L mutation, three had the V804L mutation and S836S polymorphism in separate alleles, and six had the S836S polymorphism, all in heterozygous forms. Two of the family members had neither mutation nor polymorphism of the RET gene. Three of the family members who had the V804L mutation and one member who could not be tested for mutation were operated for non‐metastatic MTC, while one member with MTC who had the V804L mutation refused surgery. In all patients affected with MTC, the disease developed relatively late in life and never caused death. None of the other family members carrying the V804L mutation and/or the S836S polymorphism had clinical or biochemical evidence of MTC. These observations suggest that the co‐existence of the V804L mutation and S836S polymorphism in separate alleles does not seem to aggravate the relatively low‐risk disease phenotype characteristic in most patients with codon 804 mutations of the RET exon 14.
The contribution of USH1C mutations to syndromic and non‐syndromic deafness in the UK
Authors: Blaydon DC , Mueller RF , Hutchin TP , Leroy BP , Bhattacharya SS , Bird AC , Malcolm S , Bitner‐Glindzicz M
Published: December 2004

Denaturing high‐performance liquid chromatography (DHPLC) was used to screen 14 UK patients with Usher syndrome type 1, in order to assess the contribution of mutations in USH1C to type 1 Usher. In addition, 16 Caucasian sib pairs and two small consanguineous families with non‐syndromic deafness, who were concordant for haplotypes around DFNB18, were also screened for mutations in the USH1C gene. Two Usher type 1 patients were found to have the 238–239insC mutation reported previously; one of Greek Cypriot origin was homozygous for the mutation and another Caucasian was heterozygous. This indicates that mutations in the USH1C gene make a greater contribution to Usher syndrome type 1 than originally thought, which has implications for the genetic testing of families with Usher syndrome in the UK. Analysis using intragenic single nucleotide polymorphisms (SNPs) revealed that the haplotypic background bearing this common mutation was not consistent across the gene in two families, and that there are either two haplotypes on which the mutation has arisen or that there has been a recombination on a single haplotype. We found no evidence of mutations in USH1C in the patients with non‐syndromic deafness, suggesting that the gene is not a major contributor to autosomal‐recessive non‐syndromic deafness in the UK.
Failure to induce supracrestal bone growth between and around partially inserted titanium implants using bone morphogenetic protein (BMP): an experimental study in dogs
Authors: Stenport Victoria Franke , Roos‐Jansåker Ann‐Marie , Renvert Stefan , Kuboki Yoshinori , Irwin Chris , Albrektsson Tomas , Claffey Noel
Published: December 2004

Abstract: The effect of bone morphogenetic protein on supracrestal bone growth around partially inserted implants in a dog model is described. The lower premolar teeth (P1, P2, P3 and P4) were extracted on both sides of the mandible in six dogs. At a surgical exposure 12 weeks later, two 10‐mm turned titanium implants were partially inserted, approximately 15 mm apart, in the areas of the P1 and P3 in each side of the mandible, allowing five threads to protrude from the bone crest. A titanium mesh was fastened to the coronal aspect of the two fixtures and the space beneath the mesh was filled with bone morphogenetic protein (S300 BMP) in combination with an insoluble bone matrix carrier, or with the carrier alone. The mesh was covered with an ePTFE membrane. Thus, a space for potential bone formation was created between the two implants. The surgical flaps were coronally positioned and secured with vertical mattress sutures. After 16 weeks of healing, biopsy specimens were retrieved and examined histologically. Bone was not formed around the protruding implants or in the created space between the implants in any case. The carrier was incompletely resorbed. We conclude that supracrestal bone growth beyond the crestal limit with or without BMP in such a large space as in this experimental design may not be possible.
Satisfaction and psychosocial aspects of patients with an extremely resorbed mandible treated with implant‐retained overdentures
Authors: Stellingsma Kees , Bouma Jelte , Stegenga Boudewijn , Meijer Henny J. A. , Raghoebar Gerry M.
Published: December 2004

Abstract: The objective of the present report was to study the effect of implant treatment on subjective parameters in edentulous patients with an extremely resorbed mandible. Three different treatment modalities to support an overdenture were compared: transmandibular implant according to Bosker, augmentation of the mandible followed by four endosseous implants, and the insertion of four short endosseous implants. Sixty patients [50 women and 10 men, mean (± SD) age 59 (± 11) years] met the inclusion criteria and were assigned in one of the three treatment groups. Before treatment and 12 months after placement of the new overdentures, denture satisfaction, psychosocial aspects and experiences during the surgical phase were assessed with a battery of questionnaires. After 1 year, 58 patients were available for evaluation: one patient had died, and one patient had moved out of the region. There was a significant improvement of patient satisfaction and psychosocial functioning in all three treatment groups. At the 1‐year evaluation, differences amongst the three groups were not significant. However, in terms of discomfort and pain during the surgical phase as well as the length of this phase (at least 6 months), the augmentation using an autologous bone graft from the iliac crest followed by inserting four endosseous implants 3 months later appeared the least favorite option of the three modalities studied.
A longitudinal study of quality of life outcomes in older adults requesting implant prostheses and complete removable dentures
Authors: Allen P. F. , McMillan A. S.
Published: December 2004

Abstract: A longitudinal clinical trial involving 103 subjects was undertaken to assess the impact of oral implant therapy on the psychosocial well‐being of subjects with complete denture wearing problems. There were four experimental groups: (1) an implant group, where subjects were edentulous/edentate in one jaw and requested and received implants to retain an oral prosthesis (IG); (2) subjects edentulous/edentate in one jaw requesting implants but who received conventional dentures (CDG1); (3) edentulous subjects requesting replacement of their dentures by conventional means (CDG2); (4) dentate subjects requiring routine treatment, who were included for comparison. Data were collected in each group pre‐ and post‐treatment using validated oral specific [the Oral Health Impact Profile (OHIP)], and generic (the SF36) health status measures. Subjects in IG, CDG1 and CDG2 also completed a denture satisfaction scale.

IG and CDG1 subjects reported that tooth loss and denture wearing problems had a much greater impact on their quality of life than subjects seeking conventional dentures. Dentate subjects had a much better oral health status compared with denture‐wearing subjects. Following treatment, subjects who received implant‐retained prostheses (IG) reported a significant improvement in satisfaction and health‐related quality of life, as did subjects who requested and received conventional dentures (CDG2). Subjects who requested implants, but received conventional dentures (CDG1), reported little improvement in denture satisfaction and only modest improvement in their quality of life. None of the denture‐wearing subjects reported health‐related quality of life that was as good as that of dentate subjects. The findings have significant implications in the assessment of outcomes in future clinical trials.
Surgical placement of two implants in the anterior edentulous mandible – how much time does it take?
Authors: Takanashi Yoshiaki , Penrod John R. , Chehade Antoine , Klemetti Esa , Lund James P. , Feine Jocelyne S.
Published: December 2004

Abstract: In order for clinicians to effectively manage their practices, they need to know how much time they spent in carrying out procedures. The provision of two‐implant overdentures for edentulous patients is becoming more prevalent as increasing evidence demonstrates their great benefit to patients. The aim of this study was to measure the number of visits and the time required during the surgical phase (from pre‐op examination to preliminary impressions) of mandibular two‐implant overdenture treatment. Thirty edentulous patients were assigned to receive two root‐form implants in the mandible between the mental foramen, as part of a randomized controlled clinical trial. All visits and time spent by the oral surgeon, the surgical assistant and the prosthodontist were measured individually. The mean number of scheduled visits with the oral surgeon was four, and the mean time taken was 104 min. The mean time taken by the surgical assistant was 122 min. On average, the prosthodontist was required for two visits, with a total mean time of 36 min. In addition to the scheduled visits, 14 patients solicited additional appointments (unscheduled visits) for various problems (e.g. loose healing cap). The average time taken for unscheduled visits was 32 min. Combining scheduled and unscheduled visits, the mean total time taken by the oral surgeon was 109 min. The surgical assistant was needed for a mean total of 125 min, and the prosthodontist spent, on average, 46 min in this phase of treatment. Results from this study will assist clinicians in establishing the total time and number of visits needed for the surgical phase of two‐implant mandibular overdenture treatment.
Maxillary sinus floor augmention with autogenous bone grafts to enable placement of SLA‐surfaced implants: preliminary results after 15–40 months
Authors: Stricker Andres , Voss Pit J. , Gutwald Ralf , Schramm Alexander , Schmelzeisen Rainer
Published: December 2004

Abstract: This study presents preliminary results of placing SLA® surfaced ITI® implants in conjunction with maxillary sinus floor augmentations using autogenous bone. One hundred and eighty three ITI implants (SLA® surface) were inserted after 66 sinus floor elevation procedures in 41 consecutive patients. Forty‐eight implants were placed simultaneously and 135 implants in a staged procedure with an average healing time of 4.9 months (148 days) after sinus grafting. Loading of the implants was allowed following an average time of 4.1 months (122 days). The follow‐up time was 15–40 months after implant placement. Clinical follow‐up consisted of single tooth and panoramic X‐rays, and determination of Bleeding On Probing (BOP) and Plaque Index. One implant failed. One hundred and eleven of the inserted implants were used for fixed dentures, 20 for bar constructions, 41 for single crowns, and 11 were loaded provisionally until today. The total 2‐year implant survival rate was 99.5%. Keeping the short follow‐up period in mind, the encouraging results compared with previous studies, further support the findings of a positive influence of rough surfaces in grafted bone.
Regeneration of nerve fibres in the peri‐implant epithelium incident to implantation in the rat maxilla as demonstrated by immunocytochemistry for protein gene product 9.5 (PGP9.5) and calcitonin gene‐related peptide (CGRP)
Authors: Fujii Noritaka , Ohnishi Hideo , Shirakura Masaki , Nomura Shuichi , Ohshima Hayato , Maeda Takeyasu
Published: December 2004

Abstract: The response of nerve fibres in the peri‐implant epithelium to titanium implantation was investigated with an experimental model using rat maxilla and immunohistochemical techniques. The latter employed antibodies to protein gene product 9.5 (PGP9.5), and to calcitonin gene‐related peptide (CGRP). In control rats without an implantation, a dense innervation of PGP9.5‐ and CGRP‐positive nerve fibres was recognized throughout the junctional epithelium, as has been previously reported. A titanium‐implantation induced a remarkable inflammatory reaction, as well as the destruction of covering epithelial cells. By 3–5 days post‐implantation, inflammatory reaction showed a tendency to disappear, and the peri‐implant epithelium showed proliferation and down‐growth along the implant. At this stage, no nerve fibres were found around the peri‐implant epithelium. At 10 days, a few nerve fibres reached the basal cell layers of the peri‐implant epithelium, and entered it 15 days after implantation when the peri‐implant epithelial cells showed morphological features roughly resembling those of normal junctional epithelial cells. At the complete osseointegration stage (days 20–30), the PGP9.5‐ and CGRP‐positive nerve fibres, thin and beaded in appearance, were found distributed in the peri‐implant epithelium. After 20 days, the numerical density of the intraepithelial nerves in the peri‐implant epithelium appeared the same as, or less than, that in the normal junctional epithelium. These findings indicate that the peri‐implant epithelium shows the same innervation as that in normal junctional epithelium, and that the intraepithelial nerve fibres in the peri‐implant epithelium might have diverse functions, which have been suggested in the literature.
Influence of smoking on marginal bone loss and tooth loss – a prospective study over 20 years
Authors: Jansson Leif , Lavstedt Stig
Published: December 2004

Aims:  The aim was to investigate the influence of smoking on longitudinal marginal bone loss and tooth loss in a prospective study over 20 years. In addition, the effect of cessation of smoking on bone loss and the interaction between smoking, plaque and marginal bone loss were evaluated.

Material and Methods:  A total of 507 dentate individuals from an epidemiological study were examined in 1970 and 1990. The clinical investigation included registration of number of remaining teeth and presence of plaque. The marginal bone level was determined by assessments on the proximal surfaces on the radiographs from 1970 and 1990. The marginal bone loss was defined as the difference in marginal bone level over 20 years. The subjects were interviewed about smoking habits. Stepwise multiple regression analyses were adopted to calculate the influence of the independent variables on longitudinal marginal bone loss and tooth loss.

Results:  In 1970, 50.7% of the subjects were smokers, while the corresponding relative frequency in 1990 had decreased to 31.0%. Smoking was significantly correlated to an increased marginal bone loss over 20 years. Individuals who stopped smoking between 1970 and 1990 lost significantly less marginal bone during this period than those who declared that they smoked during the 20‐year period. Smoking was not found to be significantly correlated to tooth loss over 20 years.

Conclusions:  The results support the hypothesis that smoking is a significant risk factor of periodontal disease.
Assessment of periodontal conditions and systemic disease in older subjects
Authors: Persson R. E. , Hollender L. G. , MacEntee M. I. , Wyatt C. C. L. , Kiyak H. A. , Persson G. R.
Published: December 2004

Background:  An increased risk for periodontitis has been associated both with type‐1 or insulin dependent diabetes (IDDM) and with type‐2 or non‐insulin dependent diabetes (NIDDM).

Aims:  1) To describe and analyze periodontal conditions in older low‐income ethnic diverse subjects with or without a diagnosis of diabetes. 2) To assess to what extent diabetes mellitus is associated with periodontal status, and 3) how periodontitis ranks as a coexisting disease among other diseases in subjects with diabetes mellitus.

Material and methods:  Radiographic signs of alveolar bone loss were studied in 1101 older subjects 60–75 years old (mean age 67.6, SD±4.7). The number of periodontal sites and the proportions of teeth with probing depth (PD) 5 mm, clinical attachment levels (CAL) 4 mm were studied in a subset of 701 of the subjects.

Results:  IDDM was reported by 2.9% and NIDDM by 9.2% of the subjects. The number of remaining teeth did not differ by diabetic status. The number of sites with PD 5 mm and the proportion of PD with 5 mm was significantly smaller in the non‐diabetic group (χ2=46.8, p<0.01, and χ2=171.1, p<0.001, respectively). Statistical analysis failed to demonstrate group differences for the number and proportions of sites with CAL 4 mm and for radiographic findings of alveolar bone loss. Combining all periodontal parameters revealed that the Mantel‐Haenszel common odds of having IDDM/NIDDM and periodontitis was 1.8 : 1 (95% CI: 1.1–3.1, p<0.03). The common odds ratio estimate of an association between heart disease and diabetes was 3.6 : 1 (95% CI: 2.1–2.6, p<0.001).

Conclusions:  Probing depth differences between IDDM/NIDDM vs. non‐diabetic subjects may reflect the presences of pseudo‐pockets and not progressive periodontitis in many subjects with diabetes mellitus. Periodontitis is not a predominant coexisting disease in older subjects with diabetes mellitus.