bluuebunny/crossref_metadata_2025 huggingface dataset:
Intermolecular and intramolecular interactions calculated with ab initio perturbative configuration interaction method using strongly localized orbitals
Authors: Otto P. , Ladik J.
Published: December 2004

We have applied the ab initio formulation of the perturbative configuration interaction using localized orbitals (PCILO) method up to third order to calculate intermolecular and intramolecular interaction energies going beyond the ab initio Hartree–Fock calculation. For the rotational barrier in ethane our results agree well with the experimental value and the cis‐ and even the trans‐barriers in HOOH are at least qualitatively reproduced with the aid of the STO‐3G basis set. In the case of the water dimer we obtain an equilibrium intermolecular distance and interaction energy which are confirmed by other calculations. We can further conclude from our studies that one has to include higher orders in the perturbation expansion as the system becomes more complicated. It is especially the last aspect which hinders the application of the ab initio PCILO to estimate the major part of the electron correlation energy for large molecules.
CrCr Multiple bonding in binuclear complexes
Authors: De Mello Paulo Corrêa , Edwards W. Daniel , Zerner Michael C.
Published: December 2004

A simple analysis of the bonding between the d orbitals in binuclear complexes of chromium indicate that the usual multiple bond picture used to describe these systems is incomplete. This analysis is fairly general and depends only on the symmetry of these complexes and the rather weak coupling between the 3d orbitals on the two metal centers. A series of INDO calculations on Cr2Cl8−4 and Cr2(CH3)8−4 are reported, and suggest that the dominant description of the bonding is one of two Cr atoms antiferromagnetically coupled. Although this description properly accounts for the eclipsed versus staggered conformations found for these systems, the calculated bond length is too long. An analysis of the components of the wave function suggests that the role of multiple bonded structures (configurations) may be small but is important in its influence in shifting the very flat potential energy surfaces to shorter CrCr distances.
Electronic structure and vertical excitation spectrum of methylene amidogen CH2N
Authors: Adams George F. , Yarkony David R. , Bartlett Rodney J. , Purvis George D.
Published: December 2004

Ab initio electronic structure calculations are reported for five electronic states of the methylene amidogen radical. Structure parameters for the ground electronic state are predicted by RHF and D‐MBPT (4) calculations. Vertical excitation energies were determined using four different theoretical chemical models: complete active space (CAS) MCSCF, CAS/MCSCF plus singles and doubles Cl, fourth‐order many‐body perturbation theory SDQ‐MBPT(4), and coupled‐cluster theory.
Semiclassical time‐correlation function approach to collisional energy transfer into many‐atom systems
Authors: Micha David A.
Published: December 2004

Cross sections for energy transfer into many‐body systems can be expressed in terms of time‐correlation functions (TCFS) of transition operators. A semiclassical version is presented by treating internal motions as quantized and relative motions as classical. The time evolution of internal motions can be calculated in the Heisenberg picture and avoids expansions in target states. The decoupling of fast and slow internal motions is treated and applied to vibrational–rotational decoupling in polyatomic molecules. Results are presented for Li+‐CO2 collisions.
Core hole induced charge‐transfer reactions in disubstituted benzenes
Authors: Ågren Hans
Published: December 2004

The application of the charge‐transfer concept on core electron ionization in donor–acceptor molecules is analyzed. A single excitation picture, involving the highest occupied and lowest unoccupied molecular orbitals is compared with a full π‐valence orbital active space model. The connections between the notion of charge transfer in donor–acceptor species with the shake‐up picture used for core photoelectron spectra of small molecules and with the dynamical screening concept applied on surface–adsorbate spectra are discussed.
Interacting stereo‐irregular chains: A model for conducting polymers
Authors: Stafström S. , Riklund R. , Chao K. A.
Published: December 2004

Interacting stereo‐irregular chains of hydrogen atoms, which simulate the topological structure of many conducting polymers, are generated by a computer and solved numerically with the unrestricted Hartree–Fock method with a modified spin polarized potential. The electron localization is investigated, and a mechanism for the interchain tunneling is discovered. Local antiferromagnetic ordering is derived which may explain the AF behavior observed in some conducting polymers.
Random‐walk theory for localization
Authors: Chaturvedi Meena , Srivastava Vipin
Published: December 2004

A continuous‐time random‐walk theory has been developed for Anderson localization. On a continuous time scale random walks are performed along extended (i.e., propagating) and localized (i.e., trap) states. Complete information of disorder is contained in a distribution function called “hopping time distribution function” ψnm(t), which gives the probability per unit time for transition from state m to state n in time t. The “stay‐put” probability 𝒫(t = ∞), which is the probability to rediscover an excitation at a site “0” at time t = ∞ if it was there at t = 0, is obtained in terms of ψnm(t). Appropriate forms for ψnm(t) are constructed which are in conformity with the photoconductivity experiments on dispersive transport, and 𝒫(∞) are calculated. The results indicate that the entire spectrum consists of three regimes, namely, those of (i) “diffusion,” (ii) “weak diffusion,” and (iii) “no diffusion,” which, respectively, designate the extension, the power‐law localization, and the exponential localization of states. The results also shed light on the question of “continuous or discontinuous (?)” transition across the mobility edge.
Application of photoelectron spectroscopy to biologically active molecules and their constituent parts. IX. 1,4‐Benzodiazepin‐2‐ones
Authors: Klasinc L. , Ruščić B. , Sabljić A. , Trinajstić N.
Published: December 2004

The Hel photoelectron (PE) spectra of desmethyldiazepam, diazepam, oxazepam, temazepam, 3‐(S)‐methyldesmethyldiazepam, 3‐(S)‐methyldiazepam, 5‐methyl‐2H‐1,4‐benzodiazepin‐2‐one, and benzophenonmethylimine have been measured and analyzed. Their low‐energy regions (up to 12.0 eV) have been completely assigned by the composite molecule method using the PE spectra of diphenylmethane, benzophenonmethylimine, acetamide, chlorobenzene, and acetophenonmethylimine to compare the electronic structure of equivalent parts.
Oligomerization of the diaphanous‐related formin FHOD1 requires a coiled‐coil motif critical for its cytoskeletal and transcriptional activities
Authors: Madrid Ricardo , Gasteier Judith E. , Bouchet Jérôme , Schröder Sebastian , Geyer Matthias , Benichou Serge , Fackler Oliver T.
Published: December 2004

The diaphanous‐related formin homology 2 domain containing protein 1 (FHOD1) interacts with the Rac GTPase and activates the Rho‐ROCK cascade leading to the formation of actin stress fibers. Here, we report the detection of homotypic interactions of FHOD1 in the yeast two‐hybrid system, by co‐immunoprecipitation and co‐localization in mammalian cells. A predicted coiled‐coil motif C‐terminal to the core FH2 domain, but not the core FH2 domain itself, was critical for self‐association of FHOD1. Deletion of both the coiled‐coil motif and the core FH2 domain abrogated formation of actin stress fibers and activation of transcription of the serum response element by FHOD1. In contrast, these motifs were dispensable for the physical and functional interaction of FHOD1 with Rac1. Together, these results indicate that oligomerization of FHOD1 via the coiled‐coil motif is a critical parameter for its biological activities.
Resistin mRNA levels are downregulated by estrogen in vivo and in vitro
Authors: Huang Seng-Wong , Seow Kok-Min , Ho Low-Tone , Chien Yueh , Chung Dong-Yue , Chang Chih-Ling , Lai Ying-Hsiu , Hwang Jiann-Loung , Juan Chi-Chang
Published: December 2004

Resistin, a hormone secreted by adipocytes, is suggested to be an important link between obesity and diabetes. The aim of this study was to evaluate the regulatory effect of estrogen on adipocyte resistin gene expression in ovariectomized (OVX) rats and in isolated rat adipocytes in vitro. Subcutaneous injection of estradiol benzoate reduced resistin mRNA levels in adipocytes isolated from the inguinal, parametrial, perirenal, retroperitoneal, or periovarian fat deposits of OVX rats, while an in vitro study showed that estradiol treatment decreased resistin mRNA levels in cultured rat periovarian fat adipocytes. Results of Western blotting analysis also showed that estrogen decreased adipose resistin contents in vivo and in vitro. These data suggest that estrogen is a pivotal negative regulator of resistin gene expression.
Inhibition of GSK3β by indirubins restores HIF‐1α accumulation under prolonged periods of hypoxia/anoxia
Authors: Schnitzer Steffen E. , Schmid Tobias , Zhou Jie , Eisenbrand Gerhard , Brüne Bernhard
Published: December 2004

Hypoxia inducible factor 1 is regulated by the appearance of the HIF‐1α subunit. HIF‐1α is subjected to proteasomal destruction or enhanced protein translation, which requires the phosphatidylinositol 3‐kinase (PI3K)/Akt pathway. We investigated how PI3K/Akt and glycogen synthase kinase 3β (GSK3β) affect HIF‐1α in human RKO cells under prolonged periods of severe hypoxia/anoxia. 16‐ to 32‐h lasting incubations attenuated Akt activity and decreased HIF‐1α protein. This was reproduced by blocking PI3K with LY294002. GSK3β inhibition by indirubins circumvented the effect of hypoxia/anoxia or LY294002 on HIF‐1α. Ruling stability regulation of HIF‐1α protein and/or enhanced transcription of HIF‐1α mRNA via GSK3β inhibition out is suggestive for translational modulation of HIF‐1α under the influence of GSK3β.
Managing build‐to‐order short life‐cycle products: benefits of pre‐season price incentives with standardization
Authors: Weng Z.Kevin , Parlar Mahmut
Published: December 2004

In this paper we consider a firm that can produce standardized products (SP) or customized build‐to‐order products (BOP) with short life‐cycles. We develop a stochastic dynamic programming model to study the effect of offering price incentives to those customers who are willing to commit themselves to purchasing the cheaper‐to‐produce standardized product. The market’s reaction to price incentives is captured by modeling the probabilistic behavior of two exclusive groups of customers who may be “price‐sensitive” or “price‐insensitive” and who are willing to commit themselves. We develop an analytic expression for the distribution of the demand for the BOP conditional on the actual number of committed demands for SP following the price‐incentive announcement. We show that price incentives expand the total expected demand while reducing demand uncertainty and we present conditions under which it is optimal to offer a price incentive. Sequentially made price incentive and capacity decisions for the BOP that maximize expected profit are obtained by solving the dynamic programming problem. We provide a comparative statics analysis and examine the effect of varying parameter values on the optimal price‐incentive discount rate. We also describe a numerical study and present a sensitivity analysis of the profit improvement obtained after offering price incentives. We show that for low purchase probability, large number of customers in the price‐sensitive group and high profit margin price incentives can substantially improve the expected profit.
Money and macroeconomic performance: revisiting divisia money
Authors: Darrat Ali F. , Chopin Marc C. , Lobo Bento J.
Published: December 2004

Recent research suggests that the relation between money and the macroeconomy has sharply weakened in the U.S. after 1980. We reexamine this alleged breakdown by testing for cointegration between the macroeconomy and simple‐sum and Divisia monetary aggregates. We check the robustness of our results by modeling multiple key breakpoints around the early 1980s. Unlike the case of simple‐sum monetary aggregates, the evidence is overwhelming in its support for cointegration between Divisia money and macroeconomic variables, which persists despite several policy shifts and dramatic financial innovations in the post‐1980 period. These results support Divisia money over simple‐sum monetary aggregates as a guide in the implementation of monetary policy.
Childcare Policy and Local Partnerships under Labour
Authors: PENN HELEN , RANDALL VICKY
Published: December 2004

This article is concerned with explaining the relatively disappointing results of the Labour government's National Childcare Strategy to date, with particular emphasis on the role of the EYDCPs (Early Years Development and Childcare Partnerships). After briefly describing and assessing childcare policy under Labour, it suggests that limited outcomes partly reflect the constraining legacy of previous policy and provision, but must also be related to the way childcare has fitted into the wider government agenda, and ‘third way’ discourse. This has affected not only policy content but the chosen means of implementation. In this context the article focuses in particular on the local EYDCPs: both their rationale and the part they have played in practice.
New music in the Codex Faenza 117
Authors: MEMELSDORFF PEDRO
Published: December 2004

New photographic images and digital restoration have finally permitted the integral restoration and transcription of several diminutions from the manuscript Faenza, Biblioteca Comunale Manfrediana 117, hitherto impossible because of illegible passages. Above all, it has been possible to restore two completely new pieces: a Kyrie Orbis factor (virtually complete) and part of its corresponding Gloria dominicalis (Vatican Edition XI). The two new pieces are here transcribed and published for the first time, along with the completion of the diminution of Jacopo da Bologna's madrigal Sotto l'impero with the aid of photographic material and virtual restoration.
Size matters
Authors: SMITH RANSFORD
Published: December 2004

The two papers address questions related to the role and place of small, developing countries in the global trading system and in multilateral trade negotiations, reflecting the resurgence of interest in recent years in size-related constraints to development and to participation of small economies in international trade.
Small, remote and poor?
Authors: VENABLES ANTHONY J.
Published: December 2004

The two papers in this special issue both look at the problems that small economies face in participating in the world trading system. For Winters and Martins (W&M) small means small in population; they motivate their analysis with reference to the 82 countries with the smallest population, accounting collectively for less than 0.5% of world population. Many of these countries are also remote, making trade costly. For Mattoo and Subramanian (M&S) the focus is on countries that are small and poor; their list covers the 73 countries which each account for less than 0.05% of world imports and which also have low income. They investigate the engagement of these countries in the WTO. My comments will address both papers, although focus on W&M.
Promoting work at older ages: the role of hybrid pension plans in an aging population
Authors: JOHNSON RICHARD W. , STEUERLE EUGENE
Published: December 2004

Employers are beginning to search for ways to elicit more labor supply from older adults as the population ages, the ability to work in later life increases, and younger workers become relatively scarce. Many employers are turning to hybrid pension plans, such as cash balance plans and pension equity plans. Whereas traditional defined benefit plans often subsidize workers who retire early and penalize those who remain at work beyond the plan's retirement age, most hybrid plans reward work at older ages. This paper documents the impact of population aging on the labor market and changes over time in work capacity at older ages. It then shows how movement toward hybrid pension plans, among other types of private and public retirement plan reforms and redesigns, can be used to increase work incentives for older adults.
Geochemical characterization using geophysical data and Markov Chain Monte Carlo methods: A case study at the South Oyster bacterial transport site in Virginia
Authors: Chen Jinsong , Hubbard Susan , Rubin Yoram , Murray Chris , Roden Eric , Majer Ernest
Published: December 2004

The study demonstrates the use of ground‐penetrating radar (GPR) tomographic data for estimating sediment geochemical parameters using data collected at the Department of Energy South Oyster bacterial transport site in Virginia. By exploiting the site‐specific mutual dependence of GPR attenuation and extractable Fe(II) and Fe(III) concentrations on lithofacies, we develop a statistical model in which lithofacies and Fe(II) and Fe(III) concentrations at each pixel between the boreholes are considered as random variables. The unknown variables are estimated by conditioning to the colocated GPR data and the lithofacies measurements along boreholes using a Markov Chain Monte Carlo method. Cross‐validation results show that the geophysical data, constrained by lithofacies, have the potential for providing high‐resolution, multidimensional information on extractable Fe(II) and Fe(III) concentrations at the South Oyster site.
Sporadic and familial blepharophimosis –ptosis–epicanthus inversus syndrome: FOXL2 mutation screen and MRI study of the superior levator eyelid muscle
Authors: Dollfus H , Stoetzel C , Riehm S , Lahlou Boukoffa W , Bediard Boulaneb F , Quillet R , Abu‐Eid M , Speeg‐Schatz C , Francfort JJ , Flament J , Veillon F , Perrin‐Schmitt F
Published: December 2004

The analysis of the FOXL2 gene (3q23) in a series of two families and two sporadic cases affected with Blepharophimosis‐Ptosis‐Epicanthus Inversus Syndrome (BPES) is presented. This study detected two novel FOXL2 mutations (missence and nonsens mutations) and confirmed the recurrence of a previously described duplication. Magnetic Resonance Imaging (MRI) of the orbit, in one family, showed absence or hypotrophy of the eyelid superior levator muscle suggesting a possible role of FOXL2 in the development of this extra‐ocular muscle.
Skeletal dysplasias caused by a disruption of skeletal patterning and endochondral ossification
Authors: Newman B , Wallis GA
Published: December 2004

Identification of a number of the genes that cause skeletal dysplasias has helped clinicians to provide accurate diagnoses, genetic counseling, and pre‐natal diagnosis for this complex group of disorders. This review considers how some of the recent advances in human and murine genetics have led to an increased understanding of normal bone development and, in particular, the processes of skeletal patterning and endochondral ossification.
KCNQ1 mutations in patients with a family history of lethal cardiac arrhythmias and sudden death
Authors: Chen S , Zhang L , Bryant RM , Vincent GM , Flippin M , Lee JC , Brown E , Zimmerman F , Rozich R , Szafranski P , Oberti C , Sterba R , Marangi D , Tchou PJ , Chung MK , Wang Q
Published: December 2004

Long QT syndrome (LQTS) is the prototype of the cardiac ion channelopathies which cause syncope and sudden death. LQT1, due to mutations of KCNQ1 (KVLQT1), is the most common form. This study describes the genotype–phenotype characteristics in 10 families with mutations of KCNQ1, including 5 novel mutations. One hundred and two families with a history of lethal cardiac events, 55 LQTS, 9 Brugada syndrome, 18 idiopathic ventricular fibrillation (IVF), and 20 acquired LQTS, were studied by single‐strand conformational polymorphism (SSCP) and DNA sequence analyzes. Families found to have KCNQ1 mutations were phenotyped using ECG parameters and cardiac event history, and genotype–phenotype correlation was performed. No mutations were found in Brugada syndrome, IVF, or acquired LQTS families. Ten out of 55 LQTS families had KCNQ1 mutations and 62 carriers were identified. Mutations included G269S in domain S5; W305X, G314C, Y315C, and D317N in the pore region; A341E and Q357R in domain S6; and 1338insC, G568A and T587M mutations in the C‐terminus. W305X, G314C, Q357R, 1338insC, and G568A, appeared to be novel mutations. Gene carriers were 26 ± 19 years (32 females). Baseline QTc was 0.47 ± 0.03 s (range 0.40–0.57 s) and 40% had normal to borderline QTc (≤ 0.46 s). Typical LQT1 T wave patterns were present in at least one affected member of each family, and in 73% of all affected members. A history of cardiac events was present in 19/62 (31%), 18 with syncope, 2 with aborted cardiac arrest (ACA) and six with sudden death (SD). Two out of 6 SDs (33%) occurred as the first symptom. No difference in phenotype was evident in pore vs. non‐pore mutations. KCNQ1 mutations were limited to LQTS families. All five novel mutations produced a typical LQT1 phenotype. Findings emphasize (1) reduced penetrance of QTc and symptoms, resulting in diagnostic challenges, (2) the problem of sudden death as the first symptom (33% of those who died), and (3) genetic testing is important for identification of gene carriers with reduced penetrance, in order to provide treatment and to prevent lethal cardiac arrhythmias and sudden death.
Spectrum of clinical variability in familial deletion 22q11.2: from full manifestation to extremely mild clinical anomalies
Authors: Digilio MC , Angioni A , De Santis M , Lombardo A , Giannotti A , Dallapiccola B , Marino B
Published: December 2004

The 22q11.2 deletion (del22q11.2) syndrome is a genetic condition with wide interfamilial and intrafamilial variability in clinical expression. The aim of the present study was to review the prevalence of parental transmission in our series of patients with del22q11.2, and to analyse clinical findings of the affected parents. Parental transmission of del22q11.2 in our series was 17.2% (15/87), with a preferential maternal transmission (10/15). One or more major features of del22q11.2 were found in all deleted parents, but one of the mothers showed extremely mild clinical anomalies. The present data demonstrate that it should be current policy to test both parents of patients with del22q11.2, irrespective of the parental phenotype, in view of the fact that extremely mild clinical features can be detected in parents of deleted patients. This would provide accurate genetic counselling to del22q11.2 families, as relatively asymptomatic parents must be advised of the 50% risk of transmitting the deletion in a subsequent pregnancy. Various genetic and non‐genetic factors, including modifier genes at separate loci, mosaicism, unstable mutations, allelic variations at the haploid locus, chance and environmental interaction, can be hypothesized to be involved in variable clinical expression, even in the same family.
Immediate loading of single‐tooth implants in the anterior maxilla. Preliminary results after one year
Authors: Lorenzoni Martin , Pertl Christof , Zhang Kehao , Wimmer Gernot , Wegscheider Walther A.
Published: December 2004

Abstract: According to the standard protocol, a load‐free healing period is one of the most emphasized requirements for implant integration. Recent studies have encouraged a progressive shortening of the healing period for single‐tooth implants and immediate loading has been proposed for the aesthetic zone in the maxilla. The present study evaluated clinical outcomes of immediately loaded FRIALIT‐2 Synchro implants 12 months after placement in the maxillary incisal region. In the course of our investigation, nine patients have been treated following an immediate loading protocol. The stepped‐screw type implants were inserted with an increasing torque up to 45 Ncm, thus measuring the primary stability of the implants. All implants were immediately restored with unsplinted acrylic resin provisional crowns and the patients provided with occlusal splints. Regular controls were performed at monthly intervals, intraoral radiographs were taken directly after implant placement, 6 and 12 months post insertion. The survival rate, clinical stability (Periotest) and radiographic coronal bone defects (CBD) were evaluated at delivery of the definitive superstructures (CBD 6) and 6 months later (CBD 12). Twelve FRIALIT‐2 Synchro stepped screws of 3.8, 4.5 and 5.5 mm diameter and 13 and 15 mm length were placed in the incisal maxillary region. The median Periotest value 6 months post insertion was −2 with a minimum of −5 and a maximum of +2. The mean coronal bone level changes (CBD) at 6 and 12 months were 0.45 and 0.75 mm. No implant failed up to 12 months after insertion, resulting in a 100% survival rate. The presented results showed promising data for immediately loaded single‐tooth implants in the anterior maxilla. Periotest values were within the range published for submerged implants. The radiographic coronal bone resorption after 6 and 12 months was even less than evaluated for implants placed in a standard two‐stage procedure. It is evident that successful immediate loading protocols require a careful and strict patient selection aimed at achieving the best primary stability and avoiding any excessive functional or non‐functional loading. Additional research needs to be done to provide data in situations where problems of poor bone quality, multiple implants or augmentation procedures must be overcome.
Some cytokine profiles of  T‐helper cells in lesions of advanced periodontitis
Authors: Berglundh Tord , Liljenberg Birgitta , Lindhe Jan
Published: December 2004

Objective: The aim of the present study was to analyze some cytokine profiles of T‐helper cells in periodontitis lesions.

Material and methods: 22 adult patients (7 females and 15 males, aged 24–66 years) with advanced and generalized chronic periodontitis were recruited. Clinical and radiographical characteristics of periodontal disease was assessed. From each patient a gingival biopsy was obtained from one randomly selected diseased interproximal site. The soft tissue sample was prepared for immunohistochemical analysis. Double staining was performed to detect cells positive for both the CD4 marker and different cytokines, i.e. interleukin (IL)‐2, IL‐4, IL‐6 and interferon‐gamma (IFN‐γ).

Results:  The lesions in advanced periodontitis contained similar proportions of cells positive for the different cytokine markers examined. In addition, the number of cells expressing cytokine profiles for either T helper‐1 (IFN‐γ + IL‐2) or T helper‐2 (IL‐4 + IL‐6) was similar.

Conclusion:  It is suggested that the lesions of periodontitis are regulated by a combined Th‐1 and Th‐2 function.
Effect of treatment of chronic periodontitis on levels of serum markers of acute‐phase inflammatory and vascular responses
Authors: Ide M. , McPartlin D. , Coward P.Y. , Crook M. , Lumb P. , Wilson R.F.
Published: December 2004

Aims:  Recent epidemiological work suggests an association between periodontal disease severity and cardiovascular disease risk. This study aimed to ascertain if circulating levels of cardiovascular and systemic inflammatory markers could be modified following treatment of periodontal disease.

Method:  Adult subjects were recruited from those awaiting periodontal treatment and randomised to either immediate (test, n=24) or delayed treatment (control, n=15). Demographic and clinical data were collected and venous blood was taken before and either 6 weeks after completion of treatment or after an equivalent 3‐month control period. Periodontal examination included probing depth, loss of attachment, plaque scores and bleeding scores. Blood was analysed to determine serum and plasma fibrinogen, C‐reactive protein, sialic acid, tumour necrosis factor‐α and interleukin ‐6 and ‐1β. Effects of treatment were assessed by paired tests and analysis of variance by treatment group with baseline covariates.

Results:  Treatment improved plaque and bleeding scores and reduced probing depths (p<0.002). However, there were no statistically significant changes in levels of any of the systemic markers.

Conclusion:  Improvement in periodontal health did not influence the levels of vascular markers.
Enamel matrix proteins in the treatment of periodontal sites with horizontal type of bone loss
Authors: Yilmaz Selçuk , Kuru Bahar , Altuna‐Kiraç Eren
Published: December 2004

Objectives: The present study aims to assess the clinical and radiographic outcome of horizontal type of bone loss over a period of 8 months following periodontal surgery with adjunctive use of enamel matrix proteins (EMP).

Materials and Methods: Twenty patients, who received nonsurgical periodontal therapy and had radiographic horizontal bone loss with an associated probing depth (PD) of 4 mm at the maxillary incisor/canine segment, were included. One side of the selected segment divided by the mid‐sagittal plane was treated with EMP as part of a crevicular flap. The other side was treated either with a similar intracrevicular (ICI) or a reverse bevel incision (RBI) as part of a conventional flap debridement. Therefore, patients were divided into two groups of 10 patients according to the type of incision performed on the control side. The analysis was based on a classification of two severity groups according to preoperative PD, with the patient's means of measurements for each treatment being the experimental units for the statistical analysis.

Results: For pockets of 4–6 mm, EMP treatment was significantly better than the ICI/flap debridement in terms of PD reduction (p<0.001), relative attachment level (RAL) gain (p<0.001) and recession (REC) (p<0.05). Although sites exposed to EMP treatment exhibited significantly greater RAL gain than RBI/flap debridement sites (p<0.01), both treatments resulted in equally effective PD reduction. Less REC occurred with EMP application than with ICI–RBI/flap debridement (p<0.05). Treatment of shallow sites by the conventional flap with both incisions resulted in a tendency for loss of attachment whereas EMP treatment maintained the attachment levels. No significant difference in the degree of probing and radiographic bone levels was found between the treatments.

Conclusion: EMP treatment showed better clinical improvements as compared to the conventional flap debridement performed with two different incisions. Clinical improvements were more pronounced at periodontal sites with deep, rather than shallow, periodontal pockets. The results of this study provided an important preliminary base for further clinical and histologic studies.
The effect of a triclosan‐containing dentifrice on the progression of periodontal disease in an adult population
Authors: Cullinan M. P. , Westerman B. , Hamlet S. M. , Palmer J. E. , Faddy M. J. , Seymour G. J.
Published: December 2004

Objectives: The aim of the present study was to determine the effect of unsupervised, long‐term use of a 0.3% triclosan/2% copolymer dentifrice on the progression of periodontal disease in a general adult population.

Methods: Five hundred and four volunteers were enrolled in a double‐blind, controlled clinical trial. Participants were matched for disease status, plaque index, age and gender. At the baseline examination, probing pocket depths and relative attachment levels were recorded and participants were assigned to either the test or control group. Re‐examinations took place after 6, 12, 24, 36, 48 and 60 months. Subgingival plaque samples were collected at each examination and assayed for Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Prevotella intermedia. A generalised linear model was used to analyse the data, with a number of covariates thought to influence the responses included as the possible confounding effects.

Results: The triclosan/copolymer dentifrice had a significant effect in subjects with interproximal probing depths ≥3.5 mm, where it significantly reduced the number of sites with probing depths ≥3.5 mm at the following examination, when compared with the control group (p<0.001). Furthermore, this effect increased with increasing numbers of affected sites. There was no effect of the triclosan/copolymer dentifrice in individuals without probing depths ≥3.5 mm at the previous examination. Other factors significantly affecting probing pocket depths (PPD) included increasing age, smoking and presence of P. gingivalis. PPD ≥3.5 mm were positively associated with loss of attachment some 2 years later.

Conclusion: This study showed that in a normal adult population, unsupervised use of a triclosan/copolymer dentifrice is effective in slowing the progression of periodontal disease.
Dental clinic attendance in Soweto, South Africa, before and after the introduction of free primary dental health services
Authors: Bhayat Ahmed , Cleaton‐Jones Peter
Published: December 2004

Abstract –

Objective: To compare patient attendance rates 1 year before and after the introduction of free primary dental health services in Soweto, South Africa.

Methods: Monthly clinic records for clinic attendance, both casual and booked, and number of dental operators were recorded 1 year either side of April 1996.

Results: Patient attendance fluctuated by day and season. There was a mean 46% increase in attendance after free primary dental health services were introduced, with more than a sixfold increase in casual attendees (pain, sepsis) than in booked patients (restorative treatment, dentures, orthodontics).

Conclusions: There was a statistically significant increase in casual patient attendance in the year after free primary dental health care was introduced with an increased dental operator load.
Early childhood caries in northern Philippines
Authors: Cariño Khristine Marie G. , Shinada Kayoko , Kawaguchi Yoko
Published: December 2004

Abstract –

Objectives: To determine prevalence and severity of early childhood caries (ECC) among children in northern Philippines. Further, to describe and determine the impact of child‐rearing practices and dental visits on caries status.

Methods: Cross‐sectional survey of 993 children aged 2–6 years . Caries was diagnosed based on WHO recommendations. Additional behavioral information was obtained from 452 children aged 3–6 years.

Results:  Caries prevalence and mean dmft (±SD) by age were as follows: 2 years = 59% (4.2 ± 5.3); 3 years = 85% (7.4 ± 5.5); 4 years = 90% (8.8 ± 5.6); 5 years = 94% (9.8 ± 5.5); and 6 years = 92% (10.1 ± 5.5). Caries rates mirrored those of developing countries with untreated lesions dominating all ages. Mixed breast and bottle feeding was the norm. Almost half were weaned at more than 2 years old. Majority had toothbrushing practices, but mostly without parental assistance. Toothbrushing was initiated at an average age of 2 years. Only a small proportion had a dental visit, mostly for emergency reasons. Among 3–4‐year‐old children, a significant increase in caries levels were noted for those who started brushing at a later age, had frequent snacks, and had a dental visit for emergency reasons. For children aged 5–6 years, those who went for emergency visits also had significantly more caries. Results indicated an urgent need to (i) increase awareness that ECC is a public health problem in these areas, (ii) advocate use of fluoride as a public health measure, and (iii) increase access to preventive dental services for preschool children.
Psychosocial consequences of dental fear and anxiety
Authors: Locker David
Published: December 2004

Abstract –

Objectives: The aim of this study was to examine the negative psychosocial impacts of dental anxiety in a sample of dentally fearful and anxious individuals recruited from the general population. The associations between psychosocial impacts, dental anxiety scale (DAS) scores and other severe fears were explored.

Methods: One hundred and thirty‐five subjects who were anxious or fearful about dental treatment were divided into low and high general fear groups based on the number of other severe fears they reported. Negative psychosocial impacts were assessed using a modified form of the scale developed by Kent et al. (1996). This consisted of three dimensions: psychological reactions, social relationships and avoidance/inhibition. Other measures included self‐ratings of oral, general and emotional health and scales to assess self‐esteem and morale.

Results: Overall, 93.1% of subjects reported one or more impacts. Those in the high‐fear group had higher psychosocial impact scores than those in the low‐fear group (means of 4.19 vs. 2.85; P < 0.05). Differences were most marked with respect to psychological consequences and avoidance/inhibition. The high‐fear group had scores indicative of lower self‐esteem and lower morale. Forward stepwise linear and logistic regression analyses indicated that both dental anxiety and general fearfulness contributed to these negative outcomes. However, the latter was a more consistent predictor in that it entered six of seven models generated while the former entered only four.

Conclusion: The study indicated that dental fear and anxiety have pervasive psychosocial consequences, and that these are more marked among subjects with high levels of general fearfulness. It also provided evidence of the validity of a modified form of the psychosocial impact scale developed by Kent et al. (1996).
Primary oxidation products affect the quantification of formaldehyde in autoxidized fatty alcohol ethoxylates when using DNPH derivatization
Authors: Sollenberg Jan , Linnerborg Malin , Bodin Anna , Karlberg Ann‐Therese
Published: December 2004

Non‐ionic surfactants, e.g. fatty alcohol ethoxylates, are considered to cause less skin irritation than other types of surfactants. However, the autoxidation of alcohol ethoxylates generates products that are both skin irritating and sensitizing, such as formaldehyde. It has been suggested that formaldehyde be used as an indicator of the degree of autoxidation of fatty alcohol ethoxylates, and thus also as an indicator of the sensitizing capacity of the product. Attempts to analyse formaldehyde in autoxidized ethoxylates using 2,4‐dinitrophenylhydrazine derivatization resulted in formation of the corresponding hydrazone not only from free formaldehyde but also from autoxidation products during the derivatization reaction. Consequently, this derivatizing agent is inappropriate for the determination of formaldehyde in autoxidized fatty alcohol ethoxylates. Focus on the content of primary oxidation products, i.e. hydroperoxides/peroxides, is suggested, particularly as they also are potent sensitizers.
Fragrance allergy and hand eczema – a review
Authors: Heydorn S. , Menné T. , Johansen J. D.
Published: December 2004

Because hand eczema and fragrance allergy are common both among patients and in the general population, simultaneous occurrence by chance must be expected. Fragrances are ubiquitous and a part of many domestic and occupational products intended for hand exposure. The present review is based on a systematic literature research using both a manual and a Medline based search. The search identified 39 studies, including epidemiological patch test studies, general population patch test studies, case studies, and studies of occupational groups. The published data indicate a possible association between fragrance allergy and hand eczema. In future studies, a more detailed exposure assessment is needed, combined with patch test studies among patients with hand eczema tested with relevant fragrance allergens, as well as experimental control exposure studies to specific fragrance allergens on the hands. As exposures to fragrances on the hands are often simultaneous exposures to irritants, this combined exposure approach needs to be considered.
Allergic contact dermatitis from occupational exposure to ranitidine hydrochloride
Authors: Ryan P. J. J. , Rycroft R. J. G. , Aston I. R.
Published: December 2004

Contact sensitivity to ranitidine hydrochloride has been demonstrated in 6 of 8 symptomatic exposed pharmaceutical manufacturing employees; a 7th has been found to be sensitized to ranitidine base. Although closed manufacturing processes diminish the risk of such sensitization, operatives with potential exposure should be made aware of the importance of avoiding skin contact.
Contact dermatitis from electrocardiograph‐monitoring electrodes: role of p‐tert‐butylphenol‐formaldehyde resin
Authors: Avenel‐audran M. , Goossens A. , Zimerson E. , Bruze M.
Published: December 2004

Three cases of allergic contact dermatitis localized to the sites of electrocardiograph‐monitoring electrodes are reported. All patients had positive patch tests to both the gel and the adhesive part of the Red Dot® 2239 3M™ monitoring electrode used and to the p‐tert‐butylphenol‐formaldehyde resin (PTBP‐F‐R) of the standard series. Two patients had a history of possible exposition to the resin previously but there was no explanation for the third. No information about the presence of PTBP‐F‐R in the electrodes could be obtained from the manufacturers. Chemical analysis of samples of the electrode, using a gas chromatography‐mass spectrometry (GC‐MS) and high pressure liquid chromatography (HPLC) analytical system, demonstrated the presence of several PTBP‐F‐R derivatives in both the gel and the adhesive part.
Carcinoma and eccrine syringofibroadenoma: a report of five cases
Authors: Bjarke Torsten , Ternesten‐Bratel Annika , Hedblad Marianne , Rausing Alf
Published: December 2004

Background:  In the literature, there are some reports of cases interpreted as carcinomatous transformation in eccrine syringofibroadenoma (ESFA).

Results:  We have studied five cases with a histological mixture of ESFA and carcinoma. The carcinoma had a partial squamous cell cytology in all cases. In two of them, there was partial poroma and porocarcinoma picture. However, the squamous cell parts had some features of porocarcinoma such as retiform configuration and funnel‐like cavities with luminal carcinoembryonic antigen (CEA) positivity. Also, there was strong epithelial membrane antigen (EMA) positivity. Therefore, we interpret the cases as porocarcinomas with extensive squamous metaplasia.

One case had a life‐long precursor lesion with a histologic picture interpreted as ESFA, with progressing cytologic atypia. Another case had ectodermal dysplasia, a condition known to predispose to ESFA and a precursor lesion of long‐standing, probably benign ESFA. In these two cases, we interpret the carcinoma as a secondary development in a benign ESFA. Three cases were otherwise healthy people with precursor lesions of 10‐, 5‐, and 2‐year duration. We do not know for certain if the ESFA preceded the carcinoma in these cases but we think that it probably did.

Conclusions:  We recommend that diagnosed ESFA shall be completely excised or followed, in view of the risk of developing carcinoma.
Designing cases in problem‐based learning to foster problem‐solving skill
Authors: Lohman Margaret C. , Finkelstein Michael
Published: December 2004

The purpose of this study was to examine the effect of case segmentation schemes in problem‐based learning (PBL) on the development of problem‐solving skill, self‐directedness and technical knowledge. Seventy‐four dental education students were randomly assigned to 12 PBL groups. Six groups experienced PBL cases that were formatted in short segments and six groups experienced PBL cases that were formatted in long segments. Pretest measures of problem‐solving skill, self‐directedness and technical knowledge were administered at the beginning of the Fall 1998 semester. Students studied three PBL cases in their assigned groups in the ensuing semester. Posttest measures were administered at the conclusion of the semester. Analysis of the data found that students who experienced PBL with a short case segmentation scheme were better able to solve problems highly similar to the problems in the teaching cases than students who experienced PBL with a long case segmentation scheme. No significant differences were found for self‐directedness, technical knowledge, or ability to solve problems distinctly different from the teaching cases. Explanations of these findings and their implications for research and practice in PBL are discussed.
Occupational exposures occurring in students in a UK dental school1
Authors: Stewardson D. A. , Palenik C. J. , McHugh E. S. , Burke F. J. T.
Published: December 2004

Background:  Students whilst training may encounter a number of incidents where infection from patient body fluids may occur, especially as their manual skills are underdeveloped and their clinical experience is limited.

Purpose of study:  (a) To assess the nature of the occupational exposures occurring to students in a UK dental school, (b) to assess the rate of reporting of incidents, and (c) to evaluate the association of various factors with these exposures. Students in the third, fourth and final years of the 5‐year undergraduate dental course at the University of Birmingham were asked to complete a questionnaire that enquired into personal details, number and nature of incidents, their reporting and follow‐up. A 100% response rate was achieved.

Results:  Across the years, there was no significant correlation (p > 0.01) between sex, dominant hand, use of protective glasses or time of day. Slightly more exposures occurred in males, right‐handed students, and in the afternoon. A significant decrease in exposures (p < 0.01) occurred within final year, and when an assistant was employed. Significantly more incidents occurred while a patient was being treated than during operational clean‐up procedures. A substantial number of dental students had experienced one or more occupational exposures during training. Of these, percutaneous injuries predominated. Junior students appear to be more likely to experience exposures, and in these students, needlestick injuries are the most common source.

Conclusions:  To reduce the incidence of these exposures, more instruction and training may be required in the earlier clinical years and more chairside assistance. Improvements are required in the monitoring of post‐screening for seroconversion after HBV immunization, and in the reporting of test results in the event of an exposure incident. Under‐reporting of incidents is common and ways to encourage and facilitate reporting should be sought.
Forest fire history in Norway: from fire‐disturbed pine forests to fire‐free spruce forests
Authors: Tryterud Elling
Published: December 2004

I have used occurrence of macroscopic charcoal particles, pollen analyses and radiocarbon datings to examine local forest fire abundance in southern and central Norway. Peat cores, covering the last 1000 to 6000 yr, were sampled from 20 bog margin and swamp forest sites, and the charcoal records documented local fire occurrence in 10 of the sites. Forest fires have not occurred in the sites located in central Norway, whereas the fire occurrence in southern Norway showed large variation among the sites. However, forest fires ceased prior to the establishment of Norway spruce Picea abies in seven of the sites, whereas the establishment of spruce preceded the fire decline in three of the sites. Odds ratio calculations indicated that it is several hundred times more likely that fires occurred prior to, than after, the spruce establishment. Although time spans between fire decline and spruce establishment showed some variation, they did not increase along a gradient from east to west in Norway, suggesting that the establishment of spruce might have initiated a change from fire‐prone to fire‐free ecosystems.