bluuebunny/crossref_metadata_2025_split huggingface dataset:
What is the natural history of nonoperated nonfunctioning pituitary adenomas?
Authors: Karavitaki N. , Collison K. , Halliday J. , Byrne J. V. , Price P. , Cudlip S. , Wass J. A. H. 
Published: August 2007

SummaryBackground  Series of patients systematically investigating the outcome of clinically nonfunctioning pituitary adenomas (NFAs) not treated by surgery or radiotherapy during long follow‐up periods are limited. Most reports involve the follow‐up of selected cases of incidentally found lesions, rendering their results unreliable on the assessment of the pros and cons of a ‘watch and wait’ policy.Objective  To investigate the outcome of a series of consecutive patients with presumed NFA (microadenoma or macroadenoma), who were not offered treatment at presentation (for a number of reasons) and were regularly followed up, and to identify possible factors predicting subsequent increase in tumour size.Patients and methods  All patients presenting to the Department of Endocrinology in Oxford between 1989 and 2005 with presumed NFA were studied retrospectively. Inclusion criteria were: (i) imaging features suggestive of a pituitary adenoma, (ii) no clinical and/or biochemical evidence of hormonal hypersecretion by the tumour, (iii) monitoring being the initial choice of management, and (iv) at least one repeat scan during the follow‐up period. Subjects presenting with acute apoplexy were excluded. Follow‐up management included clinical evaluation, assessment of the visual acuity and fields and imaging at regular intervals. The duration of observation was estimated from the dates of first and last scan.Results  Forty subjects were included in the study [18 males/22 females, median age 52 years (range 18–89), 16 with microadenoma/24 with macroadenoma]. The mean follow‐up period was 42 months (range 8–128). During the observation interval, 12·5% of the microadenomas and 50% of the macroadenomas increased in size. The 48‐month probability for enlargement was 19% for the microadenomas and 44% for the macroadenomas. Among the subjects with tumour enlargement, 57% showed new or worse visual field defects (all had macroadenomas) and 21% showed chiasmatic involvement on imaging without visual deterioration (all had macroadenomas). New or worse visual field defects were found in 67% of the macroadenomas showing increase in size. No microadenoma enlarged to cause visual deterioration. In microadenomas, sex and age at presentation were not predictors of enlargement. In macroadenomas, sex, age, visual field defects or cavernous sinus invasion at presentation were not predictors of enlargement.Conclusions  The ‘watch and wait’ policy seems reasonable for microadenomas but is probably not a safe approach for macroadenomas, which appear to have a significant growth potential; in these cases, given the lack of established medical treatment, the decision for surgical intervention should balance the presence of significant comorbidities and the anaesthetic/peri‐operative risks at presentation against the probability of tumour enlargement and its consequences, as well as the possible loss of advantages associated with early operation.
Thyroid function and anti‐thyroid autoantibodies in untreated children with vertically acquired chronic hepatitis C virus infection
Authors: Indolfi Giuseppe , Stagi Stefano , Bartolini Elisa , Salti Roberto , De Martino Maurizio , Azzari Chiara , Resti Massimo 
Published: August 2007

SummaryObjective  The reported data on thyroid function and anti‐thyroid autoantibodies in adults with untreated hepatitis C virus (HCV) infection are controversial. Data are scarce for HCV‐infected children, and only in those treated with interferon‐α (IFN‐α). We investigated thyroid function and anti‐thyroid autoantibodies in a cohort of untreated children with vertically acquired, chronic, HCV infection.Design and patients  FT4 and TSH serum levels (measured by immunometric assays) and anti‐thyroglobulin (TgA) and anti‐thyroperoxidase (TPOA) antibodies (evaluated by fluorescence enzymatic immunoassays) were studied in 36 consecutive HCV‐infected children and 150 age‐ and sex‐matched controls. The prevalence of thyroid involvement was also related to family history of autoimmune disease, distribution of HCV genotypes, and duration and activity of HCV infection.Results  Four out of 36 (11·1%) HCV‐infected children and 4/150 controls (2·7%) showed subclinical hypothyroidism [P = 0·04; relative risk (RR) 4·56, 95% confidence interval (CI) 1·08–19·21]. None of these had anti‐thyroid autoantibodies. Two out of 36 (5·6%) HCV‐infected children and 1/150 (0·7%) controls had increased TgA values with normal levels of TSH (P > 0·05). Subclinical hypothyroidism and anti‐thyroid autoantibodies were not related to family history of autoimmune disease, duration of infection, HCV viral load, liver function or different HCV genotype distribution, but seemed to be related to the presence of active HCV infection.Conclusions  Our data suggest a role for HCV infection in the development of nonautoimmune thyroid disease in untreated HCV‐infected children, confirming previous studies in adults. Clinicians should be aware of thyroid dysfunction even in untreated children.
Multi-interferogram method for measuring interseismic deformation: Denali Fault, Alaska
Authors: Biggs Juliet , Wright Tim , Lu Zhong , Parsons Barry 
Published: August 2007

SummaryStudies of interseismic strain accumulation are crucial to our understanding of continental deformation, the earthquake cycle and seismic hazard. By mapping small amounts of ground deformation over large spatial areas, InSAR has the potential to produce continental-scale maps of strain accumulation on active faults. However, most InSAR studies to date have focused on areas where the coherence is relatively good (e.g. California, Tibet and Turkey) and most analysis techniques (stacking, small baseline subset algorithm, permanent scatterers, etc.) only include information from pixels which are coherent throughout the time-span of the study. In some areas, such as Alaska, where the deformation rate is small and coherence very variable, it is necessary to include information from pixels which are coherent in some but not all interferograms. We use a three-stage iterative algorithm based on distributed scatterer interferometry. We validate our method using synthetic data created using realistic parameters from a test site on the Denali Fault, Alaska, and present a preliminary result of 10.5 ± 5.0 mm yr−1 for the slip rate on the Denali Fault based on a single track of radar data from ERS1/2.
A preliminary study investigating the survival of tetracycline resistant Enterococcus faecalis after root canal irrigation with high concentrations of tetracycline
Authors: Rossi‐Fedele G. , Roberts A. P. 
Published: August 2007

AbstractAim  To compare the ability of two Enterococcus faecalis strains to survive exposure to an irrigation solution containing a high concentration of tetracycline in the root canals of bovine teeth.Methodology  The root canals of twelve bovine incisor root sections were chemo‐mechanically prepared using commercially available drills, sodium hypochlorite and ethylenediamine tetra‐acetic acid. The root sections were divided into two groups and inoculated with either a tetracycline sensitive or resistant strain of E. faecalis. The strains are isogenic, however one contains a conjugative transposon related to Tn916 which confers resistance to tetracycline, and the other strain is sensitive to the antibiotic. After 26 days of incubation the root canals were irrigated using one of three solutions (sterile distilled water, 50% ethanol or tetracycline at a concentration of 30 mg mL−1). The roots were sampled by grinding dentine and canal contents and the debris collected were incubated in broth to assess growth.Results  Irrigation with sterile distilled water or 50% ethanol did not remove all of the cells present. The tetracycline containing solution was efficient in preventing any growth of sensitive E. faecalis, however the resistant strain was able to survive a 5 min exposure at 30 mg mL−1.Conclusions  The presence of the Tn916‐like conjugative transposon containing the tetracycline resistance gene tet(M) allowed an E. faecalis strain to survive irrigation using a solution containing an extremely high concentration of tetracycline in a root canal model.
Effect of sodium hypochlorite on human root dentine – mechanical, chemical and structural evaluation
Authors: Marending M. , Luder H. U. , Brunner T. J. , Knecht S. , Stark W. J. , Zehnder M. 
Published: August 2007

AbstractAim  To investigate the mechanical, chemical and structural alterations of human root dentine following exposure to ascending sodium hypochlorite concentrations.Methodology  Three‐point bending tests were carried out on standardized root dentine bars (n = 8 per group, sectioned from sound extracted human third molar teeth) to evaluate their flexural strength and modulus of elasticity after immersion in 5 mL of water (control), 1% NaOCl, 5% NaOCl or 9% NaOCl at 37 °C for 1 h. Additional dentine specimens were studied using microelemental analysis, light microscopy following bulk staining with basic fuchsin, and scanning electron microscopy (SEM). Numerical data were compared using one‐way anova. Bonferroni's correction was applied for multiple testing.Results  Immersion in 1% NaOCl did not cause a significant drop in elastic modulus or flexural strength values in comparison to water, whilst immersion in 5% and 9% hypochlorite reduced these values by half (P < 0.05). Both, carbon and nitrogen contents of the specimens were significantly (P < 0.05) reduced by 5% and 9% NaOCl, whilst 1% NaOCl had no such effect. Exposure to 5% NaOCl rendered the superficial 80–100 μm of the intertubular dentine permeable to basic fuchsin. Three‐dimensional SEM reconstructions of partly demineralized specimens showed NaOCl concentration‐dependent matrix deterioration. Backscattered electron micrographs revealed that hypochlorite at any of the tested concentrations left the inorganic dentine components intact.Conclusions  The current data link the concentration‐dependent hypochlorite effect on the mechanical dentine properties with the dissolution of organic dentine components.
The potential applications of cone beam computed tomography in the management of endodontic problems
Authors: Patel S. , Dawood A. , Ford T. Pitt , Whaites E. 
Published: August 2007

AbstractAim  To provide core information on cone beam computed tomography (CBCT) technology and its potential applications in endodontic practice.Summary  CBCT has been specifically designed to produce undistorted three‐dimensional information of the maxillofacial skeleton as well as three‐dimensional images of the teeth and their surrounding tissues. This is usually achieved with a substantially lower effective dose compared with conventional medical computed tomography (CT). Periapical disease may be detected sooner using CBCT compared with periapical views, and the true size, extent, nature and position of periapical and resorptive lesions can be assessed. Root fractures, root canal anatomy and the true nature of the alveolar bone topography around teeth may be assessed. CBCT scans are desirable to assess posterior teeth prior to periapical surgery, as the thickness of the cortical and cancellous bone can be accurately determined as can the inclination of roots in relation to the surrounding jaw. The relationship of anatomical structures such as the maxillary sinus and inferior dental nerve to the root apices may also be clearly visualized.Key learning points

CBCT has a low effective dose in the same order of magnitude as conventional dental radiographs.
CBCT has numerous potential applications in the management of endodontic problems.
The oral health of people with intellectual disability participating in the UK Special Olympics
Authors: Turner S. , Sweeney M. , Kennedy C. , Macpherson L. 
Published: August 2007

AbstractBackground  Research on the dental health of people with intellectual disability has consistently reported more untreated dental disease, more extractions and fewer fillings than in the general population. This paper describes the oral health of participants at the 2005 Glasgow Special Olympics (SO), relating this to the general population studied in the 1998 UK Adult Dental Health Survey (ADHS) and to participants' age and region of residence.Methods  Consenting SO participants were offered oral examinations which followed the standardized SO protocol plus an innovative soft tissue examination. Urgency of any treatment required was noted and reported to participants and carers. Three measures of good dental health – having 21 or more natural teeth, absence of fillings and having no obvious untreated decay – were compared across age groups, regions and with the general population. Logistic regression was used to control for age differences between regions.Results  In total, 1021 oral examinations were completed. Older SO participants were more likely to have fewer than 21 teeth and to have fillings, untreated decay, gum inflammation and heavy plaque levels. In all, 28% of SO participants had 21 or more teeth, no fillings and no obvious decay. Those from the north, midlands and south regions of England had significantly more chance of good dental health so defined compared with participants from Scotland [ORs 1.67 (1.09, 2.67), 1.69 (1.12, 2.54), 1.99 (1.26, 3.16), respectively]. Compared with the general population surveyed in the 1998 ADHS study, SO participants were more likely to be free from fillings and obvious untreated decay, but fewer had 21 or more natural teeth among older age groups. Nine per cent were found to have soft tissue problems, and one in four of these required follow‐up. Gum inflammation was common. Overall, 5% of participants were judged to require urgent treatment for dental or soft tissue problems and 40% to require non‐urgent treatment. This rose to 9% and 66% respectively among those aged 35 years and over.Discussion  The low prevalence of untreated decay and fillings among SO participants compared with the general population may be due to their being well supported by family and carers. The study identifies the vulnerability of the older participants to dental problems, and this may indicate greater difficulty maintaining surveillance as individuals age or informal carers become less able or available. Regional variations are similar to those found in the general population. The implications for the organization of care for this group are discussed.
A processive lipid glycosyltransferase in the small human pathogen Mycoplasma pneumoniae: involvement in host immune response
Authors: Klement Maria L. Rosén , Öjemyr Linda , Tagscherer Katrin E. , Widmalm Göran , Wieslander Åke 
Published: August 2007

SummaryThe human pathogen Mycoplasma pneumoniae has a very small genome but with many yet not identified gene functions, e.g. for membrane lipid biosynthesis. Extensive radioactive labelling in vivo and enzyme assays in vitro revealed a substantial capacity for membrane glycolipid biosynthesis, yielding three glycolipids, five phosphoglycolipids, in addition to six phospholipids. Most glycolipids were synthesized in a cell protein/lipid‐detergent extract in vitro; galactose was incorporated into all species, whereas glucose only into a few. One (MPN483) of the three predicted glycosyltransferases (GTs; all essential) was both processive and promiscuous, synthesizing most of the identified glycolipids. These enzymes are of a GT‐A fold, similar to an established structure, and belong to CAZy GT‐family 2. The cloned MPN483 could use both diacylglycerol (DAG) and human ceramide acceptor substrates, and in particular UDP‐galactose but also UDP‐glucose as donors, making mono‐, di‐ and trihexose variants. MPN483 output and processitivity was strongly influenced by the local lipid environment of anionic lipids. The structure of a major β1,6GlcβGalDAG species was determined by NMR spectroscopy. This, as well as other purified M. pneumoniae glycolipid species, is important antigens in early infections, as revealed from ELISA screens with patient IgM sera, highlighting new aspects of glycolipid function.
WaaL of Pseudomonas aeruginosa utilizes ATP in in vitro ligation of O antigen onto lipid A‐core
Authors: Abeyrathne Priyanka D. , Lam Joseph S. 
Published: August 2007

Summary waaL has been implicated as the gene that encodes the O‐antigen ligase. To date, in vitro biochemical evidence to prove that WaaL possesses ligase activity has been lacking due to the difficulty of purifying WaaL and unavailability of substrates. Here we describe the purification of WaaL, a membrane protein with 11 potential transmembrane segments from Pseudomonas aeruginosa, and the development of an in vitro O‐antigen ligase assay. WaaL was expressed in a P. aeruginosa wbpL knockout strain, which is defective in its initial glycosyltransferase for O‐antigen biosynthesis. This approach allowed the purification of WaaL without contaminating O‐antigen‐undecaprenol‐phosphate (Und‐P) molecules. Purified WaaL resolved to a monomer (35 kDa) and a dimer (70 kDa) band in SDS‐PAGE. The substrates for the O‐antigen ligase assay, O‐antigen‐Und‐P and lipid A‐core were prepared from a waaL mutant. ATP at 2–4 mM is optimum for the O‐ligase activity, and ATP hydrolysis by WaaL follows Michaelis–Menten kinetics. Site‐directed mutagenesis analysis indicated that the periplasmic loop region of WaaL is important for ligase activity. A waaL mutant of P. aeruginosa could not be cross‐complemented by waaL of Escherichia coli, which suggested that each of these proteins has specificity for its cognate core oligosaccharide.
Contribution to the search for binaries among Am stars – VIII. New spectroscopic orbits of eight systems and statistical study of a sample of 91 Am stars
Authors: Carquillat J.-M. , Prieur J.-L. 
Published: August 2007

Abstract
This paper is the last of a series devoted to the study of Am stars, with the monitoring of radial velocities of a sample of 91 objects during more than 20 yr. The purpose was to determine which stars were members of spectroscopic binaries (SBs) and study in detail those systems in order to obtain observational constraints on the origin of the Am phenomenon.
In the first part, we present the results of a detailed study of eight Am stars (HD 32893, 60489, 109762, 111057, 113697, 204918, 219675 and BD+44° 4512) observed at the Haute-Provence and Cambridge observatories with CORAVEL instruments. We find that these objects are single-lined SBs whose orbital elements are determined for the first time. HD 32893 is found to be a triple spectroscopic system whose third body might be detected by speckle interferometry. Physical parameters are inferred for the primaries of those SBs. We then investigate the influence of tidal interaction and find that it has already led to the synchronism of the primaries and to the circularization of the orbits of four of those systems.
In the second part of this paper, we present the main results of our whole programme and derive some statistical properties of Am stars. We give the recapitulating table of the orbital parameters found for the SBs of our whole sample and the list of those for which no evidence for radial velocity variations could be found during our monitoring. Our study shows that at least 64 per cent of Am stars are members of SBs. This rate is significantly greater than that of normal stars. Although some SBs may have been not detected, this study shows that a substantial fraction of Am stars do not belong to SBs: they are either isolated stars or members of wide binary systems.
We then present some statistical properties of the orbital parameters of the SBs whose primary is an Am star, on an extended sample obtained by adding 29 Am SB orbits published by other authors. The corresponding e versus log P diagram shows a cut-off between the circular and the eccentric systems at P≈ 5.6 ± 0.5 d, which indicates a typical age of 0.5 − 1 × 109 yr for the Am stars, which is in agreement with the values found in our previous detailed studies. A Monte Carlo analysis shows that the distribution of the mass function values f(m) is compatible with a power-law distribution N(m) ∝m−α of the masses m of the companions with α= 0.3 ± 0.2 or with a Gaussian distribution centred on 0.8 ± 0.5 M⊙, which indicates that the companions of Am SBs are mostly dwarf stars of type G-K-M.
Maternal dental history, child's birth outcome and early cognitive development
Authors: Daniels Julie L. , Rowland Andrew S. , Longnecker Matthew P. , Crawford Peter , Golding Jean ,   The ALSPAC Study Team
Published: August 2007

SummaryPrenatal exposure to high levels of mercury, radiation and inflammation have been associated with adverse reproductive outcomes such as increases in preterm delivery, low birthweight and delayed neurodevelopment. Few data are available to evaluate the potential effects of prenatal low‐level exposure to these factors as may occur during dental care. We evaluated maternal dental history prior to and during pregnancy in relation to birth outcomes and early communicative development among offspring in a large cohort (n = 7375) of British children born in 1991–92. Dental history was assessed by questionnaire. The child's communicative development was assessed using the MacArthur Communicative Development Inventory at 15 months of age. Total mercury was measured in umbilical cord tissue for a subset of the children.Overall, dental care, including amalgam fillings, was not associated with birth outcomes or language development. Having X‐rays taken during pregnancy was not associated with birthweight measured continuously (b = 14.7, P = 0.4), but was associated with slightly increased odds of having a term, low‐birthweight baby (OR 1.9, [95% confidence interval 1.0, 3.4]). More detailed evaluation of the potential adverse effects of elective dental treatment during pregnancy, particularly dental X‐rays, may be warranted.