bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microtensile adhesion of sealants to intact enamel
Authors: PERDIGÃO J. , FUNDINGSLAND J. W. , DUARTE S. , LOPES M. 
Published: August 2005

Summary. Contamination of etched enamel with saliva has been shown to result in sealant failure. Hydrophilic adhesives improve retention of sealants when enamel is contaminated.Objective. The objective of the present study was to characterize the adhesion of two sealants to unprepared enamel etched with phosphoric acid or conditioned with the all‐in‐one, self‐etch adhesive Adper Prompt L‐Pop.Methods. The two proximal enamel surfaces of 16 sound molars were assigned to four conditioning regimens: (1) 35% phosphoric acid for 15 s; (2) Adper Prompt L‐Pop, one layer light‐cured prior to sealant placement; (3) Adper Prompt L‐Pop, two layers light‐cured prior to sealant placement; and (4) Adper Prompt L‐Pop, one layer co‐cured with sealant. One of two sealants, i.e. Clinpro or Delton DDS, was applied, light‐cured, followed by a composite build‐up to provide support for microtensile bond testing.Results. The highest mean bond strengths were obtained when Adper Prompt L‐Pop was applied in two layers and light‐cured prior to the insertion of Clinpro Sealant. Co‐cure of Adper Prompt L‐Pop with either sealant resulted in bond strengths which were not significantly different from those of the phosphoric acid control. The use of Adper Prompt L‐Pop in one layer cured prior to sealant placement resulted in statistically lower bond strengths than any other application technique regardless of the sealant used. Clinpro Sealant resulted in statistically higher bond strengths than Delton DDS Sealant.Conclusions. Application of one layer of Adper Prompt L‐Pop co‐cured with the sealant resulted in bond strengths similar to those obtained with phosphoric acid etching.
Factors associated with active white enamel lesions
Authors: FERREIRA M. Â. F. , MENDES N. S. 
Published: August 2005

Summary. Objective. The aim of this study was to assess the factors associated with the presence of active white enamel lesions among public school students in the city of Natal, Brazil.Methods. A convenience sample of 300 boys and girls aged between 7 and 12 years was selected among the pupils attending public schools in the city of Natal. Only those children presenting with opaque and rough‐surface white lesions in a region of biofilm accumulation on the vestibular surface of permanent upper incisors were included. The investigation took the form of a cross‐sectional study. A chart containing individual data was used, and a clinical examination was performed to determine the oral health status of the children, including caries (DMF‐s1, DMF‐s2, DMFdmf, dmf and total number of teeth with caries) and oral hygiene status (Gingival Bleeding Index and Visible Plaque Index). Data underwent descriptive analysis and analysis of variance, and chi‐square tests were used for the comparison of continuous and dichotomous variables between groups with one, two, or three or more white lesions.Results. On average, each child presented with 2·3 teeth affected by white lesions, relatively high indices of dental caries and poor oral hygiene, with an 85% rate of localized plaque on the surfaces of teeth with lesions. The presence of visible plaque was statistically significant between the three groups, based on the number of lesions (P = 0·006), indicating a positive association between the number of lesions and the presence of biofilm.Conclusion. There is a strong association between the presence of dental biofilm, high indices of caries and active white enamel lesions. Full professional effort is needed in order to motivate children to carry out oral hygiene sufficient for the adequate control of dental biofilm.
An investigation of language used by children to describe discomfort expected and experienced during dental treatment
Authors: HARMAN K. , LINDSAY S. , ADEWAMI A. , SMITH P. 
Published: August 2005

Summary.  Objectives. A study of dental pulp testing has shown that children's linguistic comprehension and chronological age independently influence their descriptions of pain. The present study sought first to demonstrate this for expectations and experience of routine dental treatment, and secondly, to determine whether the effect of age was the result of previous dental and medical experience.Sample. Forty‐six children between 6 and 17 years of age attending two paediatric dental clinics for routine invasive procedures comprised the study sample.Methods. To describe their expectations of forthcoming treatment, each child selected words from a published list, and gave ratings on scales describing the degree of severity as ‘sore’ or ‘tingly’. They also completed the Child Dental Anxiety Scale and the Spielberger State‐Trait Anxiety Scale for Children. After treatment, they described the treatment with the same list and scales, then completed the British Picture Vocabulary Scale and a dental–medical history questionnaire.Results. The children, especially the most anxious ones, chose more words from the list for their expectations than for their experience of treatment, suggesting, as in previous studies, that they expected more discomfort than they experienced. Ratings of ‘sore’ and ‘tingly’ did not show this discrepancy. For both expectations and experience of treatment, the children with the largest vocabularies chose the fewest words, thus being more discriminating in their choices. However, vocabulary had no effect on ratings of ‘sore’ and ‘tingly’. There were no significant relationships among age, estimates of discomfort and medical–dental histories.Conclusions. The results suggest that a list of adjectives provides the most discriminating measure of discomfort. They also show that it is necessary to take into account children's linguistic development to evaluate their estimates of pain so as not to entertain the belief of many clinicians that children exaggerate such reports.
The effect of an intermediate layer of flowable composite resin on microleakage in packable composite restorations
Authors: ZISKIND D. , ADELL I. , TEPEROVICH E. , PERETZ B. 
Published: August 2005

Summary.  Objectives. The aim of the present study was to evaluate the effect of a thin layer of flowable composite on microleakage in Class II direct packable composite resin restorations on young permanent teeth in vitro.Methods. Twenty sound human premolars and molars extracted for orthodontic reasons were selected for this study. The teeth were randomly assigned into two groups of 10 teeth each (groups A and B). Class II cavities were prepared as uniformly as possible in the mesial and distal aspects of each tooth. The gingival margin extended apically approximately 0·5 mm beyond the cemento‐enamel junction, in the dentin. Cavities in group A were restored with packable composite and Alert®/Flow‐it® flowable composite, while groups B cavities were restored with Pyramid®/Aeliteflo®. The control cavities in groups A1 and B1 were restored with only packable composite. The teeth were immersed in 2% methylene blue solution for 24 h to allow dye penetration into possible existing gaps between the tooth substance and the restorative material. All teeth were subjected to thermocycling.Results. The dye penetration ranged between 6·6 and 7·2 mm. No significant difference was found between the control and the experimental groups.Conclusion. The use of flowable composite resin as intermediate material does not reduce microleakage.
The biological sciences in nursing: a developing country perspective
Authors: Kyriacos Una , Jordan Sue , Van Den Heever Jean 
Published: August 2005

Aim.  This paper reports a study to inform curriculum development by exploring the contribution of bioscience education programmes to nurses’ clinical practice, their understanding of the rationale for practice, and their perceptions of their continuing professional development needs.Background.  The future of the health services worldwide depends on nurse education programmes equipping practitioners to deliver safe and effective patient care. In the developed world, the structure and indicative content of nursing curricula have been debated extensively. However, despite the rapid expansion in nursing roles brought about by social change, there is little information on the educational needs of nurses in developing countries.Methods.  This study was undertaken in government teaching hospitals in Cape Town, South Africa in 2003. A purposive sample of 54 nurses from a range of clinical settings completed questionnaires and described critical incidents where bioscience knowledge had directed practice. Questionnaires were analysed descriptively, in the main. Analysis of critical incident reports was based on Akinsanya's bionursing model.Findings.  Most nurses felt that their understanding of the biological, but not the physical sciences, was adequate or better: all felt confident with their knowledge of anatomy, compared with 57·4% (31/54) for microbiology. Respondents attributed the successes and failures of their education programmes to their teachers’ delivery of content, ability to relate to practice and management of the process of learning. The biological, but not the physical, sciences were universally (96–100%) regarded as relevant to nursing. However, the critical incidents and nurses’ own reports indicated a need for further education in pharmacology (40/54, 74·1%) and microbiology (29/54, 53·7%).Conclusion.  To meet the needs of nurses in developing countries, and empower them to meet the increasingly complex demands of their expanding roles, nurse educators need to consider increasing the curriculum content in certain key areas, including pharmacology and microbiology.
Parenting experiences during cancer
Authors: Helseth Sølvi , Ulfsæt Nina 
Published: August 2005

Aim.  This paper reports a study to increase our understanding of how cancer affects childcare through assessing the parenting experiences of cancer patients and their spouses with young children.Background.  A parent's cancer brings insecurity into the life of a child. It affects their well‐being and increases their needs for comfort and care. However, little research has been conducted to understand how a parent's illness affects parenting and the care of the child. The study was carried out in 2001–2002.Methods.  An explorative design was chosen and data were collected through in‐depth interviews with a convenience sample of 18 parents of 23 children (aged 0–18 years) in 10 families.Findings.  Parents described living in a state of emergency. Cancer was consuming their energy, physically and emotionally. In spite of their difficulties, they were striving to be good parents. Positive aspects of illness reported were a shift of priorities and change of values that often brought family members closer together. The parents would face the challenges of illness by making the best of it, putting the needs of the children in focus and trying to maintain normal family life. The overall aim of parenting would be to protect the children and make the illness situation as secure and normal as possible for them.Conclusion.  Cancer is a challenge and often necessitates changes in parenting roles, responsibilities and goals. In the future, nurses need to approach parents with young children more directly about these extra challenges, and offer them further assistance in dealing with them.
Regulation of Expression of Mammalian Gonadotrophin‐Releasing Hormone Receptor Genes
Authors: Hapgood J. P. , Sadie H. , Van Biljon W. , Ronacher K. 
Published: August 2005

AbstractGonadotrophin‐releasing hormone (GnRH), acting via its cognate GnRH receptor (GnRHR), is the primary regulator of mammalian reproductive function, and hence GnRH analogues are extensively used in the treatment of hormone‐dependent diseases, as well as for assisted reproductive techniques. In addition to its established endocrine role in gonadotrophin regulation in the pituitary, evidence is rapidly accumulating to support the expression and functional roles for two forms of GnRHR (GnRHR I and GnRHR II) in multiple and diverse extra‐pituitary mammalian tissues and cells. These findings, together with findings indicating that mutations of the GnRHR are linked to the disease hypogonadotrophic hypogonadism and that GnRHRs play a direct role in neuronal migration and reproductive cancers, have presented new therapeutic targets and intensified research into the structure, function and mechanisms of regulation of expression of GnRHR genes. The present review focuses on the current knowledge on tissue‐specific and hormonal regulation of transcription of mammalian GnRH receptor genes. Emerging insights, such as the discovery of diverse regulatory mechanisms in pituitary and extra‐pituitary cell types, nonclassical mechanisms of steroid regulation, the use of composite elements for cell‐specific expression, the increasing profile of hormones involved in regulation, the complexity of kinase pathways that target the GnRHR I gene, as well as species‐differences, are highlighted. Although further research is necessary to understand the mechanisms of regulation of expression of GnRHR I and GnRHR II genes, the GnRHR is emerging as a potential target gene for facilitating cross‐talk between neuroendocrine, immune and stress‐response systems in multiple tissues via autocrine, paracrine and endocrine signalling.
Effects of Calmodulin on Aromatase Activity in the Preoptic Area
Authors: Balthazart J. , Baillien M. , Charlier T. D. , Ball G. F. 
Published: August 2005

AbstractOestrogens derived from the neural aromatisation of testosterone play a key role in the activation of male sexual behaviour in many vertebrates. Besides their slow action on gene transcription mediated by the binding to nuclear receptors, oestrogens have now been recognised to have more rapid membrane‐based effects on brain function. Rapid changes in aromatase activity, and hence in local oestrogen concentrations, could thus rapidly modulate behavioural responses. We previously demonstrated that calcium‐dependent kinases are able to down‐regulate aromatase activity after incubations of 10–15 min in phosphorylating conditions. In the present study, in quail hypothalamic homogenates, we show that Ca2+ or calmodulin alone can very rapidly change aromatase activity. Preincubation with 1 mM EGTA or with a monoclonal antibody raised against calmodulin immediately increased aromatase activity. The presence of calmodulin on aromatase purified by immunoprecipitation and electrophoresis was previously identified by western blot and two consensus binding sites for Ca2+‐calmodulin are identified here on the deduced amino acid sequence of the quail brain aromatase. The rapid control of brain aromatase activity thus appears to include two mechanisms: (i) an immediate regulatory process that involves the Ca2+‐calmodulin binding site and (ii) a somewhat slower phosphorylation by several protein kinases (PKC, PKA but also possibly Ca2+‐calmodulin kinases) of the aromatase molecule.
Species delimitation in native South American fire ants
Authors: ROSS KENNETH G. , SHOEMAKER D. DEWAYNE 
Published: August 2005

AbstractThe taxonomy of fire ants has been plagued by difficulties in recognizing species on the basis of morphological characters. We surveyed allozyme markers and sequences of the mtDNACOIgene in several closely related nominal species from two areas of sympatry in the native ranges to learn whether the morphology‐based delimitation of these species is supported by genetic data. We found thatSolenopsis invictaandSolenopsis richteri, pest species whose distinctiveness has been debated, appear to be fully reproductively isolated at both study sites. This isolation contrasts with the extensive hybridization occurring between them in the USA, where both have been introduced. We also found strong genetic differentiation consistent with barriers to gene flow betweenSolenopsis quinquecuspisand the other two species. However, several lines of evidence suggest that nuclear and mitochondrial genes ofS. invictaandS. richteriare introgressing intoS. quinquecuspis. The latter apparently is a recently derived member of the clade that includes all three species, suggesting that there has been insufficient time for its full development of intrinsic isolating mechanisms. Finally, our discovery of genetically distinct populations within bothS. invictaandS. richterisuggests the presence of previously unrecognized (cryptic) species. Their existence, together with the difficulties in developing diagnostic morphological characters for described species, imply that the group is actively radiating species and that morphological divergence generally does not keep pace with the development of reproductive isolation and neutral genetic divergence in this process.
Chloroplast and microsatellite DNA diversities reveal the introduction history of Brazilian peppertree (Schinus terebinthifolius) in Florida
Authors: WILLIAMS DEAN A. , OVERHOLT WILLIAM A. , CUDA JAMES P. , HUGHES COLIN R. 
Published: August 2005

AbstractBrazilian peppertree (Schinus terebinthifolius) is a woody perennial that has invaded much of Florida. This native of northeastern Argentina, Paraguay, and Brazil was brought as an ornamental to both the west and east coasts of Florida at the end of the 19th century. It was recorded as an invader of natural areas in the 1950s, and has since extended its range to cover over 280 000 ha. Our goals were to understand the history of this invasion, as one step toward understanding why this exotic was so successful, and ultimately to improve development of biological control agents. We sampled plants from the native and exotic ranges, particularly Florida, and genotyped these individuals at nuclear and chloroplast loci. Nuclear microsatellite and cpDNA loci reveal strong genetic population structure consistent with limited dispersal in the introduced and native ranges. Bayesian clustering of microsatellite data separates the east and west coast plants in Florida into distinct populations. The two chloroplast haplotypes found in Florida are also concordant with this separation: one predominates on the east coast, the other on the west coast. Analysis of samples collected in South America shows that haplotypes as distinct as the two in Florida are unlikely to have come from a single source population. We conclude that the genetic evidence supports two introductions of Brazilian peppertree into Florida and extensive hybridization between them. The west coast genotype likely came from coastal Brazil at about 27° south, whereas the east coast genotype probably originated from another, as yet unidentified site. As a result of hybridization, the Florida population does not exhibit low genetic variation compared to populations in the native range, possibly increasing its ability to adapt to novel environments. Hybridization also has important consequences for the selection of biocontrol agents since it will not be possible to identify closely co‐adapted natural enemies in the native range, necessitating more extensive host testing.
Challenges for identifying functionally important genetic variation: the promise of combining complementary research strategies
Authors: VASEMÄGI A. , PRIMMER C. R. 
Published: August 2005

AbstractStrategies for the identification of functional genetic variation underlying phenotypic traits of ecological and evolutionary importance have received considerable attention in the literature recently. This paper aims to bring together and compare the relative strengths and limitations of various potentially useful research strategies for dissecting functionally important genetic variation in a wide range of organisms. We briefly explore the relative strengths and limitations of traditional and emerging approaches and evaluate their potential use in free‐living populations. While it is likely that much of the progress in functional genetic analyses will rely on progress in traditional model species, it is clear that with prudent choices of methods and appropriate sampling designs, much headway can be also made in a diverse range of species. We suggest that combining research approaches targeting different functional and biological levels can potentially increase understanding the genetic basis of ecological and evolutionary processes both in model and non‐model organisms.
Carbohydrate engineering of the recognition motifs in streptococcal co‐aggregation receptor polysaccharides
Authors: Yoshida Yasuo , Ganguly Soumya , Bush C. Allen , Cisar John O. 
Published: August 2005

SummaryThe cell wall polysaccharides of certain oral streptococci function as receptors for the lectin‐like surface adhesins on other members of the oral biofilm community. Recognition of these receptor polysaccharides (RPS) depends on the presence of a host‐like motif, either GalNAcβ1‐3Gal (Gn) or Galβ1‐3GalNAc (G), within the oligosaccharide repeating units of different RPS structural types. Type 2Gn RPS of Streptococcus gordonii 38 and type 2G RPS of Streptococcus oralis J22 are composed of heptasaccharide repeats that are identical except for their host‐like motifs. In the current investigation, the genes for the glycosyltransferases that synthesize these motifs were identified by high‐resolution nuclear magnetic resonance (NMR) analysis of genetically altered polysaccharides. RPS production was switched from type 2Gn to 2G by replacing wefC and wefD in the type 2Gn gene cluster of S. gordonii 38 with wefF and wefG from the type 2G cluster of S. oralis J22. Disruption of either wefC or wefF abolished cell surface RPS production. In contrast, disruption of wefD in the type 2Gn cluster or wefG in the type 2G cluster eliminated β‐GalNAc from the Gn motif or β‐Gal from the G motif, resulting in mutant polysaccharides with hexa‐ rather than heptasaccharide subunits. The mutant polysaccharides reacted like wild‐type RPS with rabbit antibodies against type 2Gn or 2G RPS but were inactive as co‐aggregation receptors. Additional mutant polysaccharides with GalNAcβ1‐3GalNAc or Galβ1‐3Gal recognition motifs were engineered by replacing wefC in the type 2Gn cluster with wefF or wefF in the type 2G cluster with wefC respectively. The reactions of these genetically modified polysaccharides as antigens and receptors provide further insight into the structural basis of RPS function.
Protein phosphatases in MAPK signalling: we keep learning from yeast
Authors: Martín Humberto , Flández Marta , Nombela César , Molina María 
Published: August 2005

SummaryBecause of their key role in cell signalling, a rigorous regulation of mitogen‐activated protein kinases (MAPKs) is essential in eukaryotic physiology. Whereas the use of binding motifs and scaffold proteins guarantees the selective activation of a specific MAPK pathway, activating kinases and downregulating phosphatases control the appropriate intensity and timing of MAPK activation. Tyrosine, serine/threonine and dual‐specificity phosphatases co‐ordinately dephosphorylate and thereby inactivate MAPKs. In budding yeast, enzymes that belong to these three types of phosphatases have been shown to counteract the MAPKs that govern the cellular response to varied extracellular stimuli. Studies carried out with these yeast phosphatases have expanded our knowledge of essential key aspects of the biology of these negative regulators, such as their function, the mechanisms that operate in their modulation by MAPK pathways and their binding to MAPK substrates. Furthermore, yeast MAPK phosphatases have been shown to play additional and essential roles in MAPK‐mediated signalling, controlling MAPK localization or cross‐talk among pathways. This review stresses the importance of these negative regulators in eukaryotic signalling by discussing the recent developments and perspectives in the study of yeast MAPK phosphatases.