bluuebunny/crossref_metadata_2025_split huggingface dataset:
An audit of the technical quality of primary orthograde root canal treatment performed by undergraduate dental students
Authors: Adams N. S. , Tanday A. X. , Lumley P. J. 
Published: August 2008

Aim  To investigate the technical quality of primary orthograde root canal treatment performed by undergraduate dental students.Methodology  A retrospective radiographic analysis of the technical standard of root canal treatment performed over 1 year of the undergraduate course was undertaken. All primary root canal treatments performed by late 4th and final year students between 1 April 2006 and 31 March 2007 were evaluated. All students had completed an introductory laboratory course using stainless steel hand instruments and Gates Glidden drills and a subsequent course using Nickel titanium instruments. Additionally, some students completed a voluntary one‐term special study module (Endodontics) for 12 sessions. All radiographs of completed root canal treatments were assessed as to the technical quality of the root filling. Two calibrated observers assessed the radiographs under standard conditions using a lightbox and SDI radiograph viewer. The root fillings in each canal were assessed by length, satisfactory being within 0–2 mm of the radiographic apex, quality of obturation (absence of voids) classified as satisfactory, and taper, with the radiographic appearance of a uniform taper classed as satisfactory. The type of clinic, either a general restorative or endodontic was also recorded.Results  A total of 266 root canals were evaluated in 149 teeth. The final radiograph was unsuitable in four teeth and one tooth was extracted shortly after canal preparation. The remaining sample size was 253 canals in 144 teeth (61 anterior, 37 premolar, 46 molar). No endodontic instruments were fractured during the study. Overall, 163 individual root canals (64.4%) and 87 teeth (60.4%) were classed as satisfactory. Fifty‐five canals and 21 teeth (one lower anterior, five premolars, 15 molars) were treated on the endodontic clinic, 46 canals (83.6%) and 15 teeth (71.4%) of these were satisfactory. A total of 198 canals in 123 teeth (60 anterior, 32 premolar, 31 molar) were treated on the restorative clinic with 117 canals (59.1.6%) and 72 teeth (58.5%) being satisfactory.Conclusions  Overall, 60.4% of teeth met the criteria of root filling within 2 mm of the radiographic apex, no voids and uniform taper. A higher percentage of compliance was noted on the endodontic special study module.
The effect of conditioning films on colonization of root canal dentine by endodontic bacterial isolates
Authors: Flynn D. , Ready D. R. , Mordan N. , Pratten J. , Gulabivala K. 
Published: August 2008

Aim  To determine if conditioning films have an effect on the initial attachment of primary colonisers to root canal pre‐dentine.Methodology  Noncarious, unrestored, extracted human teeth with single root canals were prepared to expose the pre‐dentine. Half of the samples (n = 50) were untreated (native), whilst the other half (n = 50) were treated with 2.5% NaOCl for 10 min and 17% EDTA for 2 min. The samples were then soaked in a designated conditioning solution; artificial saliva, human saliva, serum or blood for 90 min at 37 °C. The samples were then placed into a Constant Depth Film Fermentor and inoculated with either single [Streptococcus oralis (E01‐07‐008)] or dual species clinical isolates [S. oralis and Actinomyces naeslundii (E01‐07‐007)]. After 4 h, the samples were removed and prepared for SEM and viable counts to assess the bacterial attachment on their surfaces.Results  Bacteria were observed on all samples when incubated with S. oralis. NaOCl/EDTA‐treated surfaces had less S. oralis colonization for all conditioning films. The number of bacteria ranged up to 4.4 × 104 CFU per sample; specimens not chemically treated but soaked in artificial saliva exhibited the most colonization. This was 17.4‐fold higher than the serum/chemically treated group. Colonization of specimens was over 90% lower with dual species than with a single isolate. Blood or serum‐treated surfaces had greater colonization (24‐fold difference in CFUs) for dual isolates than those treated with artificial saliva. Streptococcus oralis and A. naeslundii were capable of invading dentinal tubules within 4 h. Streptococcus oralis colonization was more common than that by A. naeslundii at the selected time interval. There was a random distribution of bacteria over the entire pre‐dentine surface but more bacterial attachment was observed in ‘secluded areas’ such as ‘giant tubules’, in voids in the conditioning film or around debris.Conclusions  Bacterial colonization of pre‐dentine surfaces appeared to be influenced by species, surface pre‐treatment and conditioning agent.
Cutting ability of a KiS 2D tip with varying powers and loads
Authors: Tabiat‐Pour S. , Tomson P. L. M. , Lumley P. J. , Walmsley A. D. , Lea S. C. 
Published: August 2008

Aim  To correlate the vibrations of a retro tip under a range of loads and generator powers with its cutting ability.Methodology  A scanning laser vibrometer was used to measure the maximum vibration displacement amplitude of a KiS 2D tip (Obtura Spartan, USA) under loads of 10–50 g (10 g increments). Loads were applied by contacting the tip against a polished root dentine surface (1200 grit) and were measured using a load cell (RDP Electronics, UK). A calibrated scale was placed over the power dial of the generator (Piezon Master 400; EMS, Switzerland) which enabled incremental power settings (1–5) to be selected between minimum and quarter power of the total generator output. Ten repeat scans were made for each load and generator power combination. The retro tip was then used to create cavities in polished dentine surfaces. The tip was operated using the same experimental conditions as described above (five power settings, 10–50 g loads). For each condition, the tip was contacted against surfaces for 5 s and used to make 10 repeat cavities. Cavities were scanned with a 3D laser profilometer (TaiCaan, UK), enabling the maximum width and length of the cavity to be measured. The same generator and handpiece were used throughout the experiment.Results  Load significantly reduced tip vibration displacement amplitude at 30–50 g (P < 0.0001) when compared with 10 and 20 g. Conversely, it was found that loads of 30–50 g led to either no significant difference (P = 0.242) or even significant increases (P < 0.02) in the length and width of the cavities produced when compared with those obtained at 10 and 20 g. Profile views of the cavities, obtained through laser profilometry, suggest that greater loads may cause chipping of the dentine near the surface.Conclusions  It is clinically recommended that low loads are exerted on tips to reduce the incidence of fracture. This recommendation is supported by this work which showed that, at loads greater than 20 g, tip vibration displacement amplitude was significantly reduced. Although the length and width of the cavities produced increased at greater loads, it is suggested that the instrument breaks up dentine distant to the periphery of the instrument with a chipping action, potentially causing the instrument to be less precise.
The influence of bisphosphonates on bone generation using a chick femur model
Authors: Wei W. L. L. , Gellynck K. , Ng Y.‐L. , Gulabivala K. , Buxton P. 
Published: August 2008

Aim  To determine the effect of a bisphosphonate (pamidronate) delivered using one of two carriers on bone generation, using a chick femur model supported by the chorio‐allantoic membrane of a chick egg.Methodology  Twenty chick femurs freshly harvested from fertilized eggs were randomly allocated into two groups: (i) Affi‐Gel blue bead carrier (n = 10); and (ii) hydroxyapatite bead carrier (n = 10). The femurs in each group were further randomly divided into control (n = 4) and experimental (n = 6) subgroups. Carriers charged with PBS solution and 0.1 mol L‐1 pamidronate were delivered into the bone marrow of each femur at its mid portion via a needle puncture. Each femur was then implanted onto the chorio‐allantoic membrane of a chick egg and incubated for 7 days. From each control subgroup femur, four consecutive histological sections were obtained after processing at the mid‐portion of the puncture site to act as the inter‐bone control. From each experimental subgroup femur, two consecutive histological sections were obtained after processing at a distance of 400–450 μm from both ends of the puncture site to act as the intra‐bone control; and four consecutive histological sections were obtained from the mid portion of the puncture site to act as the tests. Bone generation was quantified and the ratio of cross‐sectional area of bone marrow to circumference of bone (outcome ratio) was determined amongst different groups using a software package, Image‐Pro®Plus. The data were analysed using Mann–Whitney tests and Wilcoxon signed rank tests.Results  The outcome ratio in the test group was significantly (P < 0.001) smaller than the inter‐bone and intra‐bone control groups. There was evidence of bone formation directly over the carriers charged with pamidronate.Conclusions  The successfully developed test model was able to establish that local deposition of pamidronate had a positive effect on bone generation within a period of 7 days, regardless of the carrier used.
Safety evaluation of individual non‐fried and fried sunflower oil, paraffin oil, jojoba oil and their binary mixtures on rat health
Authors: Farag Radwan S. , Farag Mostafa M. , Basuny Amany M. , Mohammed Rehab F. 
Published: August 2008

SummarySunflower, jojoba, paraffin oils and binary oil mixtures of sunflower, jojoba and sunflower–paraffin oils were continuously heated at 180 °C for 12 h. Aliquots of potato chips were fried in the aforementioned oil samples. Organoleptic tests were performed on fried chips and safety limits of the oil samples were measured by certain biochemical tests. Histopathological examinations of rat liver and kidney tissues were microscopically done. Organoleptic results for fried potato chips indicate that all types of chips obtained from heated oils were categorised good. Histopathological examinations indicate changes in rat tissues of liver and kidney paralleled the biochemical data. In general, the results suggest that paraffin oil alone and in mixtures with sunflower oil have to ban its use in frying processes.
A mechanistic simulation model of seed dispersal by animals
Authors: Will Heidrun , Tackenberg Oliver 
Published: August 2008

Summary

In order to investigate seed dispersal by animals on a landscape scale, we developed the spatially explicit, individual‐based mechanistic model SEED (Simulation of Epi‐ and Endozoochorous Seed Dispersal). The purpose of the model is to predict patterns and densities of seeds dispersed by animals (especially mammals) within a simulated landscape.
The model was parameterized for sheep, cattle and deer as vectors but may be applied to other animals if data for parameterization is available. The model data base currently includes parameter values for about 100 plant species.
Seed attachment to and seed detachment from the fur, as well as seed excretion after passage through the gut, are explicitly simulated by drawing randomly from distributions that were determined by standardized experiments. Animal movement is simulated as a correlated random walk, but to increase reality of the model, radio‐tracking data of animals can also be used.
A sensitivity analysis of SEED was conducted to identify the relative importance of plant and animal traits. The analysis highlighted where the main gaps in our knowledge of seed dispersal processes lie. Even though in our study endozoochorous dispersal had the higher potential for long‐distance dispersal compared to epizoochory, there is only scarce knowledge about seed production and especially about the proportion of seeds eaten by an animal, parameters which were shown to be of major importance for dispersal.
A comparison of variation in plant and animal traits, respectively, showed that dispersal kernels depend more on changes in the animal vector than on the comparably little variation a particular plant species can exhibit. For this reason, animal movement is, from all the dispersal‐relevant parameters, the one for which more exact data is most urgently needed.
Synthesis. The newly developed simulation model will help to understand, quantify and predict long‐distance seed dispersal by animals. The possibility to incorporate real landscapes and movement data from very different animals makes the model generalizable and possibly applicable to a wide range of scientific and applied questions.
Tumor escape mechanisms: potential role of soluble HLA antigens and NK cells activating ligands
Authors: Campoli M. , Ferrone S. 
Published: August 2008

AbstractThe crucial role played by human leukocyte antigen (HLA) antigens and natural killer (NK)‐cell‐activating ligands in the interactions of malignant cells with components of the host’s immune system has stimulated interest in the characterization of their expression by malignant cells. Convincing evidence generated by the immunohistochemical staining of surgically removed malignant lesions with monoclonal antibodies recognizing HLA antigens and NK‐cell‐activating ligands indicates that the surface expression of these molecules is frequently altered on malignant cells. These changes appear to have clinical significance because in some types of malignant disease they are associated with the histopathological characteristics of the lesions as well as with disease‐free interval and survival. These associations have been suggested to reflect the effect of HLA antigen and NK‐cell‐activating ligand abnormalities on the interactions of tumor cells with antigen‐specific cytotoxic T lymphocytes (CTL) and with NK cells. Nevertheless, there are examples in which disease progresses in the face of appropriate HLA antigen and/or NK‐cell‐activating ligand as well as tumor antigen expression by malignant cells and of functional antigen‐specific CTL in the investigated patient. In such scenarios, it is likely that the tumor microenvironment is unfavorable for CTL and NK cell activity and contributes to tumor immune escape. Many distinct escape mechanisms have been shown to protect malignant cells from immune recognition and destruction in the tumor microenvironment. In this article, following the description of the structural and functional characteristics of soluble HLA antigens and NK‐cell‐activating ligands, we will review changes in their serum level in malignant disease and discuss their potential role in the escape mechanisms used by tumor cells to avoid recognition and destruction.
Inhibitory NKG2A and activating NKG2D and NKG2C natural killer cell receptor genes: susceptibility for rheumatoid arthritis
Authors: Park K. S. , Park J. H. , Song Y. W. 
Published: August 2008

AbstractThe inhibitory (NKG2A) and activating (NKG2D and NKG2C) natural killer (NK) cell receptors are expressed on a subset of NK and T cells. They regulate the innate and adaptive immune systems related to cytotoxicity and cytokine production that are involved in the pathogenesis of rheumatoid arthritis (RA). The role of inhibitory and activating NK cell receptor genes might contribute to chronic inflammation and destruction of bone and cartilage in RA. Therefore, we investigated the association of the NKG2A, NKG2C, and NKG2D genotypes with RA. NKG2A (KLRC1) NKG2C (KLRC2), and NKG2D (KLRK1, D12S249E) genes were genotyped in 210 unrelated patients with RA and 298 controls using a polymerase chain reaction–restriction fragment length polymorphism. We further investigated the relationships between the genotypes of each single nucleotide polymorphism and the presence of rheumatoid factor (RF), antinuclear antibody (ANA), and bony erosions in RA patients. The major NKG2A c.338‐90*A/*A, NKG2C102*Ser/*Ser, and NKG2D72*Ala/*Ala genotypes in RA were significantly associated compared with controls [P = 0.013, odds ratio (OR) = 0.6, 95% confidence interval (CI) = 0.44–0.91; P < 0.0001, OR = 2.1, 95% CI = 1.44–2.96; and P = 0.019, OR = 0.6, 95% CI = 0.45–0.93, respectively]. The minor NKG2A c.338‐90*G/*G, NKG2C102*Phe/*Phe, and NKG2D72*Thr/*Thr genotypes showed a risk of RA (P = 0.010, OR = 2.0, 95% CI = 1.17–3.54; P < 0.0001, OR = 0.2, 95% CI = 0.12–0.48; and P = 0.032, OR = 2.3, 95% CI = 1.05–5.01, respectively) compared with controls. No significance was observed between the inhibitory (NKG2A) or activating (NKG2C and NKG2D) receptor genotypes and the presence of RF, ANA, or bony erosions in RA.
Epitope mapping of mAbs to denatured human testicular ACE (CD143)
Authors: Balyasnikova I. V. , Metzger R. , Franke F. E. , Conrad N. , Towbin H. , Schwartz D. E. , Sturrock E. D. , Danilov S. M. 
Published: August 2008

AbstractAngiotensin I‐converting enzyme (ACE; CD143) has two homologous enzymatically active domains (N and C) and plays a crucial role in blood pressure regulation and vascular remodeling. A wide spectrum of monoclonal antibodies (mAbs) to different epitopes on the N and C domains of human ACE have been used to study different aspects of ACE biology. In this study, we characterized a set of nine mAbs, developed against the C domain of human ACE, which recognize the denatured forms of ACE and thus are suitable for the detection and quantification of somatic ACE (sACE) and testicular ACE (tACE) using Western blotting and immunohistochemistry on paraffin‐embedded human tissues. The epitopes for these mAbs were defined using species cross‐reactivity, phage display library screening, Western blotting and ACE mutagenesis. Most of the mAbs recognized common/overlapping region(s) on both somatic and testicular forms of human ACE, whereas mAb 4E10 was relatively specific for the testicular isoform and mAb 5B9 mainly recognized the glycan attached to Asn 731. This set of mAbs is useful for identifying even subtle changes in human ACE conformation because of denaturation. These mAbs are also sensitive tools for the detection of human sACE and tACE in biological fluids and tissues using proteomic approaches. Their high reactivity in paraffin‐embedded tissues provides opportunities to study changes in the pattern of ACE expression and glycosylation (particularly with mAb 5B9) in different tissues and cells.
Self‐Discrimination in Meadow Voles, Microtus pennsylvanicus
Authors: Ferkin Michael H. , Pierce Andrew A. , Franklin Stan 
Published: August 2008

AbstractParticular features of the signaling characteristics of the scent marks of temperate zone, seasonally breeding mammals may reflect differences in their reproductive state and, hence, be variable. Consequently, an individual’s perception of self may depend more on the condition independent than on the condition‐dependent signaling characteristics of the scent marks. Yet, we do not know whether an individual responds to changes in the signaling characteristics of its own scent marks, such as those associated with changes in an individual’s reproductive state. Such changes may affect how and where an animal scent marks. Here we report on a series of experiments designed to test the hypothesis that individual meadow voles, Microtus pennsylvanicus, distinguish between scent marks they deposited when they were in different reproductive states. Results showed that voles discriminated their own scent marks from those of unfamiliar, same‐sex conspecifics, and the scent marks of siblings. Voles did not behave as if they could distinguish between their own scent marks if the marks were deposited when the voles were in the same reproductive state, although the two scent marks used as stimuli differed in age by 30 d. However, they did so distinguish if they were exposed to scent marks taken when they were in different reproductive states. Overall, these findings suggest that voles behave as if their novel and familiar scent marks shared the similar signaling features. If, however, the reproductive condition of the voles differed when it provided the two scent marks, they behaved as if their own scent marks had different signal characteristics, which may have induced voles to treat the two scent marks as not being the same or having been deposited by two different donors. We speculate that the scent marks of individuals may have unique signaling characteristics that may be associated with that individual’s ‘current template for self’.
Skin surface lipids and skin and hair coat condition in dogs fed increased total fat diets containing polyunsaturated fatty acids
Authors: Kirby N. A. , Hester S. L. , Rees C. A. , Kennis R. A. , Zoran D. L. , Bauer J. E. 
Published: August 2008

SummaryIt is generally believed that diets containing increased amounts of polyunsaturated fatty acids (PUFA) result in improved canine skin and hair coat (SHC). However, the extent to which dietary fat amount and type play a role remains to be systematically investigated. The objective of this study was to investigate the role of both increased dietary fat amount and type on SHC assessments of dogs. Improvements of SHC conditions were investigated after feeding three diets containing increased total dietary fat (i.e. 13% total fat) for 12 weeks in relation to a lower fat acclimation diet (i.e. 9% total fat). The higher fat diets varied in polyunsaturated and saturated fat types and amounts but total fat was kept constant. Skin and hair coat assessments were performed at selected intervals by a trained group of veterinarians and graduate students. In addition, hair lipids were fractionated by thin layer chromatography after extraction of plucked hair samples. Significant improvements were found in hair coat glossiness and softness in all dogs fed the higher fat diets in relation to the acclimation diet. Improvements as a result of fat type were also seen but only at 12 weeks. A parallel finding was a marked increase in hair cholesteryl ester content determined at the end of the study at which time SHC scores were significantly improved. Skin and hair coat condition improvements may thus be related to increased cholesteryl ester deposited on the hair shaft surface when high fat diets are fed. Whereas this finding is preliminary, hair lipid analysis may be a useful, non‐invasive technique with which to help assess dietary effects on canine SHC.