bluuebunny/crossref_metadata_2025 huggingface dataset:
The calcium‐sensing receptor and its interacting proteins
Authors: Huang Chunfa , Miller R. Tyler
Published: October 2007

Introduction

Signalling by the Ca receptor

Distinct effects of angiotensin II and Ca receptors

Receptor activity modifying proteins (RAMPS)

Filamin

Potassium channels

Other CaR‐interacting proteins

Conclusions

Seven membrane‐spanning, or G protein‐coupled receptors were originally thought to act through het‐erotrimeric G proteins that in turn activate intracellular enzymes or ion channels, creating relatively simple, linear signalling pathways. Although this basic model remains true in that this family does act via a relatively small number of G proteins, these signalling systems are considerably more complex because the receptors interact with or are located near additional proteins that are often unique to a receptor or subset of receptors. These additional proteins give receptors their unique signalling ‘personalities’. The extracellular Ca‐sensing receptor (CaR) signals via Gαi, Gαqand Gα12/13, but its effects in vivo demonstrate that the signalling pathways controlled by these subunits are not sufficient to explain all its biologic effects. Additional structural or signalling proteins that interact with the CaR may explain its behaviour more fully. Although the CaR is less well studied in this respect than other receptors, several CaR‐interacting proteins such as filamin, a potential scaffolding protein, receptor activity modifying proteins (RAMPs) and potassium channels may contribute to the unique characteristics of the CaR. The CaR also appears to interact with additional proteins common to other G protein‐coupled receptors such as arrestins, G protein receptor kinases, protein kinase C, caveolin and proteins in the ubiquitination pathway. These proteins probably represent a few initial members of CaR‐based signalling complex. These and other proteins may not all be associated with the CaR in all tissues, but they form the basis for understanding the complete nature of CaR signalling.
Re‐modelling ‘hostile’ milieu of diseased myocardium via paracrine function of transplanted cells or relaxin
Authors: Du Xiao‐Jun
Published: October 2007

While the approaches of regenerating cardiac muscle remain undetermined, recent evidence indicates that paracrine function of transplanted cells contributes significantly to the beneficial effects of cell therapy. Combination of such paracrine function of grafted cells with extracellular matrix remodelling by relaxin represents a promising complement to cell‐based therapy for cardiac repair and muscle regeneration.
Circumscribed palmar hypokeratosis: two cases and a review of the literature
Authors: Barry Catherine I. , Glusac Earl J. , Kashgarian Michael , Gwin Katja , McNiff Jennifer M.
Published: October 2007

A 60‐year‐old female and a 59‐year‐old male each presented with a solitary circumscribed patch of depressed skin of the right thenar palm and right sole, respectively. Both lesions were present for approximately 30 years without a history of trauma or other inciting incident. Histologically, the lesions showed a well‐demarcated abrupt decrease in the thickness of the stratum corneum with a central area of thinned stratum corneum and hypogranulosis. Inflammation was absent. Ultrastructurally, keratin filaments were evident in the stratum corneum, and a diminished granular cell layer was apparent. There was a decrease in maturation of the keratinocytes, however, no defects in corneodesmosomes or other ultrastructural components were identified. No evidence of human papilloma virus was detected by in situ hybridization studies. Based on these 2 cases and the 25 cases reported in the literature to date, this entity seems to represent a chronic localized non‐inflammatory defect in keratinization on acral sites.
Innate Vα14+ natural killer T cells mature dendritic cells, leading to strong adaptive immunity
Authors: Fujii Shin‐Ichiro , Shimizu Kanako , Hemmi Hiroaki , Steinman Ralph M.
Published: October 2007

Summary: The observation that the glycolipid α‐galactosylceramide (α‐GalCer) is a potent stimulator of natural killer T (NKT) cells has provided an important means for investigating NKT cell biology. α‐GalCer is presented on CD1d to the invariant NKT receptor, leading to interleukin‐12 (IL‐12) production by dendritic cells (DCs) and to NK cell activation. We review our research on the tumor‐protective properties of α‐GalCer, particularly the major role played by DCs. We compared administration of α‐GalCer on mature DCs with soluble glycolipid and found that DCs induced more prolonged interferon‐γ (IFN‐γ) production by NKT cells and better protection against B16 melanoma. Human α‐GalCer‐loaded DCs also expanded NKT cell numbers in cancer patients. α‐GalCer‐activated NKT cells were then found to induce DC maturation in vivo. The maturing DCs produced IL‐12, upregulated co‐stimulatory molecules, and induced adaptive immunity to captured cellular antigens, including prolonged, combined CD4+/CD8+ T‐cell immunity to dying tumor cells. Surprisingly, co‐stimulator‐poor tumor cells, if directly loaded with α‐GalCer (‘tumor/Gal’) and injected intravenously, also induced strong NKT‐ and NK‐cell responses. The latter killed the tumor/Gal, which were subsequently cross presented by CD1d on DCs to elicit DC maturation and prolonged adaptive T‐cell immunity, which lasted 6–12 months. These findings help explain tumor protection via α‐GalCer and urge development of the DC‐NKT axis to provide innate and adaptive immunity to human cancers.
Recognition of viruses by innate immunity
Authors: Takeuchi Osamu , Akira Shizuo
Published: October 2007

Summary: The innate immune system plays critical roles in recognizing viral infections and evoking initial anti‐viral responses. Nucleotides from RNA viruses are recognized by retinoic acid‐inducible gene I (RIG‐I)‐like helicases (RLHs) and Toll‐like receptors (TLRs), and the recognition triggers signaling cascades that induce anti‐viral mediators such as type I interferons (IFNs) and pro‐inflammatory cytokines. The RLH signaling pathways play essential roles in the recognition of RNA viruses in various cells, with the exception of plasmacytoid dendritic cells (pDCs). However, TLRs are important for the production of type I IFNs in pDCs but not in other cell types. The contributions of RLHs and TLRs to the production of type I IFNs in response to RNA viruses vary depending on the route of infection. Specifically, local infections induce IFNs through RLHs but not TLRs, whereas systemic infections strongly stimulate TLRs in pDCs. In this review, we discuss recent advances toward clarifying the signaling pathways activated by RLHs and TLRs.
The trafficking of natural killer cells
Authors: Grégoire Claude , Chasson Lionel , Luci Carmelo , Tomasello Elena , Geissmann Frédéric , Vivier Eric , Walzer Thierry
Published: October 2007

Summary: Natural killer (NK) cells are large granular lymphocytes of the innate immune system that participate in the early control of microbial infections and cancer. NK cells can induce the death of autologous cells undergoing various forms of stress, recognizing and providing non‐microbial ‘danger’ signals to the immune system. NK cells are widely distributed in lymphoid and non‐lymphoid organs. NK cell precursors originate from the bone marrow and go through a complex maturation process that leads to the acquisition of their effector functions, to changes in their expression of integrins and chemotactic receptors, and to their redistribution from the bone marrow and lymph nodes to blood, spleen, liver, and lung. Here, we describe the tissue localization of NK cells, using NKp46 as an NK cell marker, and review the current knowledge on the mechanisms that govern their trafficking in humans and in mice.
Human Toll‐like receptor‐dependent induction of interferons in protective immunity to viruses
Authors: Zhang Shen‐Ying , Jouanguy Emmanuelle , Sancho‐Shimizu Vanessa , Von Bernuth Horst , Yang Kun , Abel Laurent , Picard Capucine , Puel Anne , Casanova Jean‐Laurent
Published: October 2007

Summary: Five of the 10 human Toll‐like receptors (TLRs) (TLR3, TLR4, TLR7, TLR8, and TLR9), and four of the 12 mouse TLRs (TLR3, TLR4, TLR7, TLR9) can trigger interferon (IFN)‐α, IFN‐β, and IFN‐λ, which are critical for antiviral immunity. Moreover, TLR3, TLR7, TLR8, and TLR9 differ from TLR4 in two particularly important ways for antiviral immunity: they can be activated by nucleic acid agonists mimicking compounds produced during the viral cycle, and they are typically present within the cell, along the endocytic pathway, where they sense viral products in the intraluminal space. Investigations in mice have demonstrated that the TLR7/9–IFN and TLR3–IFN pathways are different and critical for protective immunity to various experimental viral infections. Investigations in humans with interleukin‐1 receptor‐associated kinase‐4 (IRAK‐4) deficiency (unresponsive to TLR7, TLR8, and TLR9), UNC‐93B deficiency (unresponsive to TLR3, TLR7, TLR8, and TLR9), and TLR3 deficiency have recently shed light on the role of these two pathways in antiviral immunity in natural conditions. UNC‐93B‐ and TLR3‐deficient patients appear to be specifically prone to herpes simplex virus 1 (HSV‐1) encephalitis, although clinical penetrance is incomplete, whereas IRAK‐4‐deficient patients appear to be normally resistant to most viruses, including HSV‐1. These experiments of nature suggest that the TLR7‐, TLR8‐, and TLR9‐dependent induction of IFN‐α, IFN‐β, and IFN‐λ is largely redundant in human antiviral immunity, whereas the TLR3‐dependent induction of IFN‐α, IFN‐β, and IFN‐λ is critical for primary immunity to HSV‐1 in the central nervous system in children but redundant for immunity to most other viral infections.
‘Yin–Yang’ functions of transforming growth factor‐β and T regulatory cells in immune regulation
Authors: Wan Yisong Y. , Flavell Richard A.
Published: October 2007

Summary: Transforming growth factor‐β (TGF‐β) and forkhead box p3‐expressing T‐regulatory (Treg) cells are critical in maintaining self‐tolerance and immune homeostasis. The immune suppressive functions of TGF‐β and Treg cells are widely acknowledged and extensively studied. Nonetheless, recent studies revealed the positive roles of TGF‐β and Treg cells in shaping the immune system and the inflammatory responses. This review discusses our and other's efforts in understanding the negative (Yin) as well as the positive (Yang) roles for TGF‐β and Treg cells in immune regulation.
Ecto‐calreticulin in immunogenic chemotherapy
Authors: Obeid Michel , Tesniere Antoine , Panaretakis Theocharis , Tufi Roberta , Joza Nick , Van Endert Peter , Ghiringhelli François , Apetoh Lionel , Chaput Nathalie , Flament Caroline , Ullrich Evelyn , De Botton Stéphane , Zitvogel Laurence , Kroemer Guido
Published: October 2007

Summary:The conventional treatment of cancer relies upon radiotherapy and chemotherapy. Such treatments supposedly mediate their effects via the direct elimination of tumor cells. Nonetheless, there are circumstances in which conventional anti‐cancer therapy can induce a modality of cellular demise that elicits innate and cognate immune responses, which in turn mediate part of the anti‐tumor effect. Although different chemotherapeutic agents may kill tumor cells through an apparently homogeneous apoptotic pathway, they differ in their capacity to stimulate immunogenic cell death. We discovered that the pre‐apoptotic translocation of intracellular calreticulin (endo‐CRT) to the plasma membrane surface (ecto‐CRT) is critical for the recognition and engulfment of dying tumor cells by dendritic cells. Thus, anthracyclines and γ‐irradiation that induce ecto‐CRT cause immunogenic cell death, while other pro‐apoptotic agents (such as mitomycin C and etoposide) induce neither ecto‐CRT nor immunogenic cell death. Depletion of CRT abolishes the immunogenicity of cell death elicited by anthracyclines, while exogenous supply of CRT or enforcement of CRT exposure by pharmacological agents that favor CRT translocation can enhance the immunogenicity of cell death. For optimal anti‐tumor vaccination and immunogenic chemotherapy, the same cells have to expose ecto‐CRT and to succumb to apoptosis; if these events affect different cells, no anti‐tumor immune response is elicited. These results may have far reaching implications for tumor immunology because (i) ecto‐CRT exposure by tumor cells allows for the prediction of therapeutic outcome and because (ii) the re‐establishment of ecto‐CRT may ameliorate the efficacy of chemotherapy.
From T‐cell activation signals to signaling control of anti‐cancer immunity
Authors: Cronin Shane J. F. , Penninger Josef M.
Published: October 2007

Summary: The activation of resting T cells is crucial to most immune processes. Recognition of foreign antigen by T‐cell receptors has to be correctly translated into signal transduction events necessary for the induction of an effective immune response. In this review, we discuss the essential signals, molecules, and processes necessary to achieve full T‐cell activation. In addition to describing these key biological events, we also discuss how T‐cell receptor signaling may be harnessed to yield new therapeutic targets for a next generation of anti‐cancer drugs.
Autoimmune diseases caused by defects in clearing dead cells and nuclei expelled from erythroid precursors
Authors: Nagata Shigekazu
Published: October 2007

Summary: Apoptotic cells are recognized and subsequently engulfed by macrophages and immature dendritic cells. The engulfed dead cells are transported to the lysosomes of macrophages, and their components are degraded into amino acids and nucleotides for reuse. In mammals, macrophages also engulf nuclei expelled from erythroid precursors in the final stage of definitive erythropoiesis. Failure to swiftly engulf dead cells at the germinal centers of lymphoid organs causes systemic lupus erythematosus‐type autoimmune diseases. In contrast, failure to efficiently degrade the DNA of dead cells or erythroid cell nuclei activates innate immunity, causing lethal anemia in the fetus and chronic arthritis in adults.
The interaction between HMGB1 and TLR4 dictates the outcome of anticancer chemotherapy and radiotherapy
Authors: Apetoh Lionel , Ghiringhelli François , Tesniere Antoine , Criollo Alfredo , Ortiz Carla , Lidereau Rosette , Mariette Christophe , Chaput Nathalie , Mira Jean‐Paul , Delaloge Suzette , André Fabrice , Tursz Thomas , Kroemer Guido , Zitvogel Laurence
Published: October 2007

Summary: For the last four decades, the treatment of cancer has relied on four treatment modalities, namely surgery, radiotherapy, cytotoxic chemotherapy, and hormonotherapy. Most of these therapies are believed to directly attack and eradicate tumor cells. The emerging concept that cancer is not just a disease of a tissue or an organ but also a host disease relies on evidence of tumor‐induced immunosuppression and polymorphisms in genes involved in host protection against tumors. This theory is now gaining new impetus, based on our recent data showing that optimal therapeutic effects require the immunoadjuvant effect of tumor cell death induced by cytotoxic anticancer agents. Here, we show that the release of the high mobility group box 1 protein (HMGB1) by dying tumor cells is mandatory to license host dendritic cells (DCs) to process and present tumor antigens. HMGB1 interacts with Toll‐like receptor 4 (TLR4) on DCs, which are selectively involved in the cross‐priming of anti‐tumor T lymphocytes in vivo. A TLR4 polymorphism that affects the binding of HMGB1 to TLR4 predicts early relapse after anthracycline‐based chemotherapy in breast cancer patients. This knowledge may be clinically exploited to predict the immunogenicity and hence the efficacy of chemotherapeutic regimens.
High‐mobility group box 1 (HMGB1) protein at the crossroads between innate and adaptive immunity
Authors: Bianchi Marco E. , Manfredi Angelo A.
Published: October 2007

Summary: Tissue damage occurs often in the life of mammals and is usually repaired. Dying cells are swiftly phagocytosed, but before disappearing, they alert surrounding cells to activate homeostatic programs. They release signals that recruit inflammatory cells to the site of injury, promote cell migration and cell division to replace dead cells, and activate the immune system in anticipation of microbial invasion. Many of these events involve high‐mobility group box 1 protein (HMGB1), a nuclear protein that is released passively when necrotic cells lose the integrity of their membranes. HMGB1 behaves as a trigger of inflammation, attracting inflammatory cells, and of tissue repair, recruiting stem cells and promoting their proliferation. Moreover, HMGB1 activates dendritic cells (DCs) and promotes their functional maturation and their response to lymph node chemokines. Activated leukocytes actively secrete HMGB1 in the microenvironment. Thus, HMGB1 acts in an autocrine/paracrine fashion and sustains long‐term repair and defense programs. DCs secrete HMGB1 several hours after contact with the first maturation stimulus; HMGB1 secretion is critical for their ability to reach the lymph nodes, to sustain the proliferation of antigen‐specific T cells, to prevent their activation‐dependent apoptosis, and to promote their polarization towards a T‐helper 1 phenotype. These immune responses will also be directed against self‐antigens that DCs process at the time of injury and can lead to autoimmunity.
Taming cancer by inducing immunity via dendritic cells
Authors: Palucka A. Karolina , Ueno Hideki , Fay Joseph W. , Banchereau Jacques
Published: October 2007

Summary: Immunotherapy seeks to mobilize a patient's immune system for therapeutic benefit. It can be passive, i.e. transfer of immune effector cells (T cells) or proteins (antibodies), or active, i.e. vaccination. In cancer, passive immunotherapy can lead to some objective clinical responses, thus demonstrating that the immune system can reject tumors. However, passive immunotherapy is not expected to yield long‐lived memory T cells that might control tumor outgrowth. Active immunotherapy with dendritic cell (DC)‐based vaccines has the potential to induce both tumor‐specific effector and memory T cells. Early clinical trials testing vaccination with ex vivo‐generated DCs pulsed with tumor antigens provide a proof‐of‐principle that therapeutic immunity can be elicited. Yet, there is a need to improve their efficacy. The next generation of DC vaccines is expected to generate large numbers of high‐avidity effector CD8+ T cells and to overcome regulatory T cells. Therapeutic vaccination protocols will combine improved ex vivo DC vaccines with therapies that offset the suppressive environment established by tumors.
Neo‐ligands for innate immune receptors and the etiology of sterile inflammatory disease
Authors: Beutler Bruce
Published: October 2007

Summary: Microbe recognition based on a small collection of germline‐encoded receptors carries a hidden liability: the possibility that mutational changes in the proteome will lead to self‐recognition. The risk of self‐recognition is enhanced, because innate immune receptors display low specificity, as they are driven to accommodate heterogeneous signature molecules found in the microbial world. The proteome structure is globally constrained by the innate immune sensing apparatus to satisfy a proscription against self‐reactivity. But accidents happen, and here it is proposed that mutations creating neo‐ligands for innate immune receptors are the proximal cause of sterile inflammatory diseases, which in turn embody the selective pressure that constrains the proteome. Such mutations are predictably dominant and may occur in the germline and also in somatic cells (e.g. in lymphocytes), causing inflammatory effects upon clonal expansion. They may also account for the inflammatory character of selected neoplastic diseases. The neo‐ligand hypothesis accounts for the heritability, ambiguous linkage characteristics, phenotypic heterogeneity, and natural history of diverse forms of sterile inflammation. It explains sterile inflammatory diseases as conditions in which aberrant immune signaling is caused by proteome encroachment upon the ligand‐recognition space over which the innate immune system stands guard.
The adaptive immune response to sporadic cancer
Authors: Willimsky Gerald , Blankenstein Thomas
Published: October 2007

Summary: Most of the current experimental cancer models do not reflect the pathophysiology of real‐life cancer. Cancer usually occurs sporadically and is clonal in origin. Between tumor initiation and progression, clinically unapparent pre‐malignant cells may persist for years or decades in humans. Recently, mouse models of sporadic cancer have been developed. The mouse germ‐line can be engineered with high precision so that defined genes can be switched on and off in the adult organism in a targeted manner. Analysis of the immune response against sporadic tumors requires the knowledge of a tumor antigen. Ideally, a silent oncogene, for which the mice are not tolerant, is stochastically activated in individual cells. This approach offers the opportunity to analyze the adaptive immune response throughout the long process of malignant transformation and most closely resembles cancer in humans. In such a model with the highly immunogenic SV40 large T antigen as a dormant oncogene, we discovered that sporadic cancer is recognized by the adaptive immune system at the pre‐malignant stage, concomitant with the induction of tumor antigen‐specific tolerance. These results demonstrated that even highly immunogenic sporadic tumors are unable to induce functional cytotoxic T lymphocytes. Based on this model, we conclude that immunosurveillance plays little or no role against sporadic cancer and that tumors must not escape immune recognition or destruction.
The grateful dead: damage‐associated molecular pattern molecules and reduction/oxidation regulate immunity
Authors: Lotze Michael T. , Zeh Herbert J. , Rubartelli Anna , Sparvero Louis J. , Amoscato Andrew A. , Washburn Newell R. , DeVera Michael E. , Liang Xiaoyan , Tör Mahmut , Billiar Timothy
Published: October 2007

Summary: The response to pathogens and damage in plants and animals involves a series of carefully orchestrated, highly evolved, molecular mechanisms resulting in pathogen resistance and wound healing. In metazoans, damage‐ or pathogen‐associated molecular pattern molecules (DAMPs, PAMPs) execute precise intracellular tasks and are also able to exert disparate functions when released into the extracellular space. The emergent consequence for both inflammation and wound healing of the abnormal extracellular persistence of these factors may underlie many clinical disorders. DAMPs/PAMPs are recognized by hereditable receptors including the Toll‐like receptors, the NOD1‐like receptors and retinoic‐acid‐inducible gene I‐like receptors, as well as the receptor for advanced glycation end products. These host molecules ‘sense’ not only pathogens but also misfolded/glycated proteins or exposed hydrophobic portions of molecules, activating intracellular cascades that lead to an inflammatory response. Equally important are means to not only respond to these molecules but also to eradicate them. We have speculated that their destruction through oxidative mechanisms normally exerted by myeloid cells, such as neutrophils and eosinophils, or their persistence in the setting of pathologic extracellular reducing environments, maintained by exuberant necrotic cell death and/or oxidoreductases, represent important molecular means enabling chronic inflammatory states.
Prognosis of conventional root canal treatment reconsidered
Authors: Weiger R. , Axmann‐Krcmar D. , LM C.
Published: October 2007

Abstract— In endodontic literature, the so‐called success rate of conventional root canal treatment is reported to range between 70% and 95%. This has been calculated as the percentage of successfully treated teeth of all teeth followed up or included in the clinical trial. This approach, however, does not allow for valid assertions on the prognosis of root canal treatment as the individual observation times are not considered. This article discusses some methodological and statistical aspects of how to design a prognostic study which focuses on the outcome of endodontic therapy and of how to analyse the data appropriately. Methodologically, the response variable should preferably be the individual time required for the occurrence of an event, e.g., success or failure of endodontic therapy, which should clearly be defined on the basis of widely accepted criteria in endodontology. Event times can appropriately be analysed by the Kaplan‐Meier method, which estimates the probability that the event will not occur within a fixed time. This probability, together with the approximate 95% confidence interval (CI), permits an evaluation of the prognosis of a particular treatment. Two data sets were re‐analysed to clarifj, the rationale behind the analysis of event times. Accordingly, the probability that an endodontically induced lesion will completely heal, e.g., within the first 3 years after root canal therapy ranges between 0,87 (CI: 0.74–1.00) and 0.89 (CI: 0.80–0.98). In this situation, the simple calculation of success rates would overestimate the chance of complete periapical healing within the first years after therapy but underestimate it over longer observation periods. Another example was used to analyse the time to occurrence of periapical pathosis associated with root canal treated teeth not diseased periapically. In this case the chance of recording a successful endodontic treatment is initially underestimated by the percentage of successful cases of all teeth integrated in the study but is markedly overestimated for longer observation periods. Potential risk factors affecting the outcome of the endodontic therapy and thereby the event times can adequately be determined by applying the Cox's or Aalen's regression model.
Cutting pattern of nickel‐titanium files using two preparation techniques
Authors: Elliott L. M. , Curtis R. V. , Ford T. R. Pitt
Published: October 2007

Abstract— The aim of this study was to examine the cutting patterns of recently introduced nickel‐titanium endodontic files and compare them with similarly shaped stainless steel files using both balanced‐force and stepback techniques. Simulated canals were constructed in resin blocks with 40° curvature. Fifty blocks were prepared by a balanced‐force technique: 25 with Nitiflex (Maillefer) and 25 with Flexofiles (Maillefer) to a master apical file size 40. Fifty blocks were prepared by a stepback technique: 25 with Nitiflex and 25 with Flexofiles to a master apical file size 30. Composite prints were made of pre‐ and post‐instrumentation canals using a computerized imaging system. The amount of material removed from the inner and outer canal curvatures was measured at eight levels in the apical 11 mm of the canal. The results were analysed by Krus‐kal‐Wallis ANOVA. Using the balanced‐force technique, Nitiflex files removed less material on the outer curve apically and less on the inner curve mid‐canal (P<0.05), while Flexofiles caused more apical transportation. In the stepback technique, the Nitiflex files removed more material from the outer curve apically (P<0.05); the Flexofiles removed more material along the entire inner curve (P<0.05), and maintained canal curvature better than Nitiflex files. It appeared preferable to use Nitiflex files in a balanced‐force technique, and Flexofiles in a filing technique as stainless steel files can be precurved.
An in vitro evaluation of canal preparation using Profile .04 and .06 taper instruments
Authors: Kavanagh D. , Lumley P. J.
Published: October 2007

Abstract— A model system involving a double radiographic exposure technique was developed in order to evaluate maintenance of the original canal path of curved root canals. The mesiobuccal roots of 30 maxillary molars were prepared using one of three techniques (n=10 in each group). One group was instrumented using rotary Profile .04 tapers and a second group was prepared using orifice openers, rotary Profile .04 and .06 tapers. The final group was prepared using Profile hand files .02 taper and Gates‐Glidden drills. Canal transportation was evaluated in the apical, middle and coronal regions from the double‐exposed radiographs. Canal shape was determined by the ease with which a D1 1T spreader passed to within 1 mm of the working length. Time of instrumentation was also recorded. The results showed no significant difference between the techniques in canal transportation in the apical, middle or coronal regions (−0.05). It was sigdicantly easier to place the D1 1T spreader in the .06 taper group (K0.05). Canal preparation was sigdicantly quicker in the .04 taper group (P<.05). In conclusion, the use of .06 taper files improved canal shape and did not increase transportation. The additional file changes, however, increased the instrumentation time.
Sequelae of trauma to primary maxillary incisors. I. Complications in the primary dentition
Authors: Boorum M. K. , Andreasen J. O.
Published: October 2007

Abstract— Two hundred and eighty‐seven children with a total of 545 traumatized primary upper incisors were followed using standardized procedures until the age of 10. Extraction was the only treatment offered when intervention was necessary. The immediate as well as the long‐term consequences of trauma were studied on the basis of this material. Consequences in the primary dentition comprised: color changes (53%), pulp necrosis (25%), pulp canal obliteration (36%), gingival retraction (6%), permanent displacement after luxation (5–22%), pathological root resorption (1–10%) as well as disturbances in physiological root resorption (4%) and, lastly, premature tooth loss (46%). In a multivariate analysis of the development of pulp necrosis in primary teeth after trauma, the following decisive factors were found: age of the patient at the time of injury, degree of displacement of the tooth as well as the degree of loosening and presence of crown fracture. The factors found to influence development of pulp canal obliteration were: displacement of the tooth at time of injury as well as detectable physiologic root resorption at time of trauma. The presence of crown fracture seemed to decrease the risk of obliteration. The need for scientifically based treatment strategies for managing and reducing complications after trauma in the primary dentition is stressed.
Complicated crown fracture of an unerupted permanent tooth ‐ a case report
Authors: Abbott P. V. , Gregory P. J.
Published: October 2007

Abstract— Trauma to primary teeth may result in direct damage to underlying developing permanent teeth because of the close relationship that exists between the apices of the primary teeth and their permanent successors. Injuries to developing teeth have been classified into ten different categories, using a classification that is largely based on developmental alterations to the permanent teeth. However, this classification does not include other types of trauma that may occur to developing teeth, such as crown fractures. Although apparently rare, such injuries can occur by direct contact of the impacting object with a developing tooth, as illustrated by the following case report.
A quantitative comparison of traditional and non‐peroxide bleaching agents
Authors: Marin P. D. , Heithersay G. S. , Bridges T. E.
Published: October 2007

Abstract— Single‐rooted premolar teeth, stained with blood utilizing the technique devised by Freccia & Peters (1981), were subjected to traditional and non‐peroxide bleaching agents. Colour changes were recorded over a period of 7 days using a Speedmaster R75‐CP Reflection Densitometer. The most efficient removal of staining occurred after the application of 30% hydrogen peroxide, with sodium perborate being 75% as effective. AU bleaching agents realized their optimum efficacy within the first 3 days. A combination of three enzymes (amylase, lipase and trypsin) with disodium edetate was not as effective as the routine bleaching agents; however, the combination did have a modifying effect on the blood stains. It is suggested that other non‐peroxide agents should be investigated to determine their efficacy in removing staining from experimentally induced blood‐stained teeth.
Periodontal ligament vitality and histologic healing of teeth stored for extended periods before transplantation
Authors: Hupp J. G. , Mesaros S. V. , Aukhil I. , Trope M.
Published: October 2007

Abstract— A previous study evaluated the viability of dog periodontal ligament cells as indicated by tritiated thymidine uptake after extended storage in Hank's balanced salt solution and Conditioned Medium. The purpose of this study was to evaluate histologic healing following the identical storage parameters established in the earlier study. Additionally, for Conditioned Medium, matched pairs (teeth evaluated for tritiated thymidine uptake and transplanted teeth) were examined in an attempt to correlate periodontal ligament vitality and healing. Forty‐six extracted endodontically treated dogs' teeth were randomly grouped and stored in Hank's balanced salt solution or Conditoned Medium for 6, 48, and 96 h and then transplanted into 6–, 48–, and 96‐h sockets. The control group teeth were transplanted without storage into 6–, 48–, or 96‐h sockets. After 6 months the dogs were killed and the teeth were prepared for histologic evaluation according to Andreasen. Complete healing, inflammatory root resorption, and replacement re‐sorption were evaluated and compared. Overall, significantly better healing was observed for teeth stored in Conditioned Medium than for teeth stored in Hank's balanced salt soulution. Conditioned Medium was not significantly different from controls. Additionally, there was a positive correlation between periodontal ligament viability and healing for Conditioned Medium. These results confirmed the importance of periodontal ligament viability in successful replantation and the potential of Conditioned Medium as a storage medium for avulsed teeth.
Oral injury and mouthguard usage by athletes in Japan
Authors: Yamada T. , Sawaki Y. , Tomida S. , Tohnai I. , Ueda M.
Published: October 2007

Abstract— The use of mouthguards in contact sports effectively prevents oral injury and preserves oral structures. We investigated oral injuries and awareness concerning mouthguards ainong Japanese high school soccer and rugby players. Athletes were asked a series of questions concerning their history of oral injury while participating in sports, and their pattern of mouthguard use was determined. The data were evaluated statistically using chi‐square analysis. The incidence of oral injuries was 32.3% for soccer athletes and 56.5% for rugby athletes, with 0.8% and 24.1% of the respective groups having mouthguards. There were sigmficant differences between the soccer and rugby groups (p<0.001). Although 81.8% of soccer athletes thought mouthguards were unnecessary, only 26.2% of rugby athletes shared this opinion and there was a sigmficant difference between the soccer and rugby groups. Many soccer ath‐letes had insufficient knowledge about mouthguards and were not concerned about preventing oral injury, although it was in fact a common problem in their sport. Athletes as well as coaches must be made aware of the high risk of oral injury when playing soccer, rugby, and other contact sports.
The external and internal anatomy of human mandibular canine teeth with two roots
Authors: Shanna R. , Pécora J. D. , Lumley P. J. , Walmsley A. D.
Published: October 2007

Abstract— This study investigated the internal anatomy of 65 human mandibular canines with two well‐defined roots. The teeth were decalcified and injected with gelatin coloured with india ink. Diaphanization was carried out using clear resin to allow permanent preservation. It was found that all mandibular canines with two roots had two root canals. Lateral canals were found in 68.9% of teeth and 19.7% had lateral canals at the bifurcation. The results of the external measurements (cusp tip to root apex) showed that the average buccal root length was 23.0 mm and the average lingual root length was 22.7 mm. The maximum and minimum buccal lengths were 26.7 mm and 17.9 mm respectively and the maximum and minimum lingual lengths were 27.2 mm and 17.1 mm respectively. The buccal root was the larger of the two in 47.7% of teeth and 43.1% had roots of equal size. The lingual root was larger than the buccal root in 9.2% of cases. Clinicians should be aware of the anatomical variation that exists for mandibular canines.
Transplantation of displaced and dilacerated anterior teeth
Authors: Fllippi A. , Pohl Y. , Tekin U.
Published: October 2007

Abstract— The therapy of dilacerated permanent anterior teeth usually involves surgically removing the tooth. Subsequently, or‐thodontic methods for closing the space or keeping it open are preferred until the patient reaches an age when definitive im‐plantological or prosthetic treatments may be used. Anterior tooth transplantation should be considered as an alternative to surgically extracting the tooth. This study describes a period of investigation covering 3 years during which neither replacement resorption nor inflammatory resorption was diagnosed in the five transplanted teeth. The clinical tooth mobility was similar to that of the adjacent teeth. In spite of the vertical loss of bone shown radiographi‐cally no pathologically enlarged pockets or recessions have been found. It is not yet possible to make any comments on the prognosis for the long term.
A slow release calcium delivery system for the study of reparative dentine formation
Authors: Hunter A. R. , Kirk E. E. J. , Robinson D. H. , Kardos T. B.
Published: October 2007

Abstract— Several liquid, semi‐solid and solid delivery systems were formulated and tested to devise a method of reproducibly administering accurate micro‐doses of calcium into a 700 μm diameter cakity in a rat maxillary incisor tooth, in the absence of hydroxyl ions. Development of this delivery system was necessary to facilitate studies of the mechanisms of pulpal repair and odontoblast differentiation. The principal requirements for the delivery system were that it should be easily administered into a small pulp exposure in the rat incisor and that a greater than 1000‐fold range in calcium ion concentrations could be incorporated and delivered for a period of 2–3 days, preferably in an acidic environment to minimize the effect of non‐specific nucleation under alkaline conditions. Poly ethylene) glycol microspheres were found to be an ideal vehicle. Under the in vivo dissolution conditions used, complete release of all calcium salts occurred within 12–15 hours, except for the very water‐insoluble calcium stearate. It was anticipated that the re lease of calcium ions would be significantly more prolonged in vivo because of the physical constraints of the prepared cavity as well as the restricted access to fluid flow.
Effectiveness of four chemical solutions in eliminating Bacillus subtilis spores on gutta‐percha cones
Authors: Siqueira J. F. , da Silva C. H. F. Pereira , Cerqueira M. das D. O. , Lopes H. P. , de Uzeda M.
Published: October 2007

Abstract— Gutta‐percha cones should be free of pathogenic microorganisms before being used for root canal filling. This study was canied out to evaluate the effectiveness of four chemical agents in eliminating Bacillus subtilis spores from gutta‐percha cones. The solutions tested were 5.25% sodium hypochlorite, 2% glutaraldehyde, 2% chlorhexidine digluconate, and 70% ethyl alcohol. The gutta‐percha cones coated with spores were placed into contact with the chemical agents for 1, 3, 5 and 10 min. The results showed that 5.25% sodium hypochlorite was effective in destroying the spores after 1 min of contact. Glutaraldehyde, chlorhexidine and ethyl alcohol did not decontaminate the gutta‐percha cones even after 10 min of contact.
The effect of systemic tetracycline on resorption of dried replanted dogs' teeth
Authors: Sae‐Lim V. , Wang C. Y. , Choi G. W. , Trope M.
Published: October 2007

Abstract— The use of systemic penicillin after an avulsion injury has been recommended to decrease the occurrence of resorption complications. Tetracycline antibiotics have been reported to possess anti‐resorptive propemes in addition to their anti‐microbial actions. The purpose of this study was to evaluate histologically the effect of systemically administered tetracycline and amoxicillin on the inhibition of resorption due to attachment damage after replantation of dogs' teeth. Thuty‐one roots from the teeth of four beagle dogs were endodontically treated to inhibit subsequent inflammatory root resorption of pulpal origin. They were then extracted and left to bench dry for 1 h to ensure severe periodontal ligament damage before replantation. For the teeth in the experimental groups, two dogs were given tetracycline hydrochloride and the other two dogs were given amoxicillin, administered orally, on the day of extraction/replantation and for the following 6 days.

The control group were teeth in these animals treated in the same manner but where no antibiotics had been given. After 12–16 weeks, the dogs were sacrificed and histological sections were prepared and evaluated for complete healing, inflammatory and replacement root resorption, and the groups were compared. It was shown that healing in the amoxicillin and the control groups was poor (10.90% and 11.28%, respectively), while for the tetracycline group, 35.45% showed complete healing. Individual teeth with over 50% complete healing sites were considered as having good healing, and sigdicantly more of these teeth were found in the tetracycline group (5 of 11 teeth) compared to the amoxicillin (1 of 11 teeth) or control group (1 of 8 teeth).
Root resorption of replanted teeth: an SEM study
Authors: Pettini F. , Pettini P.
Published: October 2007

Abstract— Two replanted and subsequently expelled upper central incisors were observed under a scanning electron microscope to study the changes brought about by root resorption The severity of resorption and the distribution of the affected areas were different in the two specimens. In the first case, large, deep excavations were found along a continuous bone defect which exposed the opposite root canal wall. Bacteria‐like elements were found on the bottom of the eroded areas both on the outer and on the inner root surfaces. In the second case, resorption denuded the apical portion of the metal post. Erosive lacunae were visible in some areas while tubiform excavations were present close to the apical margin exposing the collagen network. The roots in the first case likely underwent inflammatory resorption while replacement resorption was thought to have occurred in the second case.
Initial treatment of traumatic dental injuries by dental practitioners
Authors: Kahabuka F. K. , Willemsen W. , Hof M. vant' , Ntabaye M. K. , Burgersdljk R. , Frankenmolen F. , Plasschaert A.
Published: October 2007

Abstract— The aim of this study was to investigate the nature of initial treatment provided by dental practitioners to children aged 1–17 years with various types of traumatic dental injuries at public dental clinics in Tanzania. Questionnaires on initial treatment were mailed to 188 practitioners and returned by 138 (73%). The reported treatments were analyzed in relation to the dental practitioners' qualifications and area of practice. Extraction of injured teeth was frequently reported for 64% of the injuries and prescription of antibiotics was reported by 67%, 48% and 46% of the practitioners for soft tissue injuries, concussion, and alveolar fracture respectively. Practitioners working at the Faculty of Dentistry were less involved in treating dental trauma than those at urban and rural clinics (P= 0.001), while no simcant association was found with the level of education of the practitioners. Equal proportions of practitioners, about one‐third each, reported correct, unnecessary and wrong treatment options. The quality of the treatments provided could not be explained by background variables. It can be concluded that dental practitioners in Tanzania provide a lot of over‐treatment for traumatic dental injuries. Therefore, it is suggested that efforts should be made to improve and standardize treatment methods in Tanzania.
Development of a computer‐assisted learning software package on dental traumatology
Authors: Tolidis K. , Crawford P. , Stephens C. , Papadogiannis Y. , Plakias C.
Published: October 2007

Abstract— The development of computer‐assisted learning software packages is a relatively new field of computer application. The progress made in personal computer technology toward more user‐friendly operating systems has stimulated the academic community to develop computer‐assisted learning for pre‐ and postgraduate students. The ability of computers to combine audio and visual data in an interactive form provides a powerful educational tool. The purpose of this study was to develop and evaluate a computer‐assisted learning package on dental traumatology. This program contains background information on the diagnosis, classification, and management of dental injuries in both the permanent and the deciduous dentitions. It is structured into chapters according to the nature of the injury and whether injury has occurred in the primary or permanent dentition. At the end of each chapter there is a self‐assessment questionnaire as well as references to relevant literature. Extensive use of pictures and video provides a comprehensive overview of the subject.
Effect of systemic tetracycline and amoxicillin on inflammatory root resorption of replanted dogs' teeth
Authors: Sae‐Lim V. , Wang C. Y. , Trope M.
Published: October 2007

Abstract— The use of systemic penicillin after an avulsion injury has been recommended as a way to decrease the occurrence of resorption complications. Our previous study has shown systemic tetracycline to possess anti‐resorptive properties independent of potential anti‐bacterial actions. The purpose of this study was to compare histologically the effectiveness of tetracycline and amoxicillin in limiting inflammatory root resorption (IR) secondary to pulpal infection, in replanted dogs' teeth. Thirty root canals in five dogs were infected with plaque. The roots were extracted, the lingual mid‐roots were shaved with a fissure bur ensuring cemental damage and immediately replanted. Dogs were given either tetracycline hydro‐chloride or amoxicillin, administered orally, on the day of extraction and replantation and for the following 6 days. The control group was teeth in these animals treated in the same manner but where no antibiotics were given. After approximately 6 months, the dogs were sacrificed and the teeth prepared for histologic evaluation. The shaved root surface was identified in cross‐sections and eight equidistant points along the cut root surface were evaluated for healing (H) or IR in eight sections per tooth. For the tetracycline group, H averaged 67.22% and IR 32.!8%, which was not statistically different from the amoxicillin group with H averaging 56.88% and IR 43.12%. The tetracycline group was superior to the control group with H= 27.86% and IR=72.14%. Since tetracycline has been shown to have anti‐resorptive properties in addition to the antibacterial properties demonstrated here, it could be considered as an alternative to amoxicillin after avulsion injuries.