bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production of interleukin‐8 in vitro by mononuclear cells isolated from human periapical lesions
Authors: Lukić A. , Vojvodic D. , Majstorović I. , Čolić M. 
Published: August 2006

Introduction:  Interleukin‐8 (IL‐8) is an important mediator of inflammation. However, little is known about its production in chronic dental periapical lesions and this was the main aim of this work.Methods:  Inflammatory cells were isolated from clinically different periapical lesions and analyzed by morphological criteria. The mononuclear cells were isolated, phenotypically analyzed by immunocytochemistry and cultivated in vitro. IL‐8 was measured in culture supernatants of these periapical lesion mononuclear cells (PL‐MNC) using a microbeads fluorescence assay.Results:  We found a relatively high production of IL‐8 in 19 out of 21 periapical lesions included in the study. The level of IL‐8 and the proportion of neutrophil granulocytes were significantly higher in the group of symptomatic lesions, compared to the asymptomatic lesions, but there was no statistically significant correlation between these parameters. According to the predominance of CD3+ T cells and Ig+/CD19+ B cells and plasma cells, lesions were divided into T‐type and B‐type lesions, respectively. The levels of IL‐8 were significantly higher in the culture supernatants of PL‐MNC in the T‐type lesions and were positively correlated with the proportion of macrophages/dendritic cells (CD11c+ cells) and CD4+ T cells. Such a correlation was not shown in B‐type lesions.Conclusion:  These results suggest that PL‐MNC are a significant source of IL‐8, which is probably an important chemokine for the migration and function of different cell types at the site of chronic inflammation.
Genotypic relatedness of yeasts in thrush and denture stomatitis
Authors: Song X. , Sun J. , Støre G. , Eribe E. R. K. , Hansen B. F. , Olsen I. 
Published: August 2006

Background/aim:  Candida is an opportunistic pathogen. Understanding its genetic characters might increase our understanding of the pathogenesis of candidosis. We examined the genetic relationships of yeasts from the most common forms of oral candidosis: thrush and denture stomatitis.Methods:  Yeasts were sampled from palate, buccal mucosa, gingival sulci/periodontal pockets and/or denture fitting surface of 19 thrush patients and 22 denture stomatitis patients. Random amplified polymorphic DNA and the Dendron computer‐assisted program were used to determine the genotypic relatedness of the yeasts.Results:  A dendrogram generated from 105 thrush isolates had similarity coefficients (SAB) ranging from 0.58 to 1 with four clusters derived at SAB 68%. Another dendrogram was generated from 91 isolates from denture stomatitis, with SAB ranging from 0.59 to 1. Three clusters were established at SAB 71%. In a composite dendrogram incorporating the thrush and denture stomatitis data and orally healthy data compiled from a previous study, five genotypic clusters were generated at SAB 68%. Cluster II, the most dominant, comprised isolates from thrush, denture stomatitis and healthy conditions, while clusters III and IV contained yeasts mainly from thrush.Conclusions:  Palatal yeast carriage was significantly increased in thrush and denture stomatitis, also after radiation, chemotherapy and denture wearing. The buccal mucosa was favorable for yeast colonization regardless of oral condition. Yeasts in thrush were more diverse than in conditions of oral health. The common clone (II) of infecting yeasts and commensals suggested that commensals could induce thrush and denture stomatitis, whereas the unique clones in thrush (III, IV) might have been established through strain replacement or maintenance with minor genetic variation.
Immunoglobulin G subclass antibody profiles in Porphyromonas gingivalis‐associated aggressive and chronic periodontitis patients
Authors: Takeuchi Y. , Aramaki M. , Nagasawa T. , Umeda M. , Oda S. , Ishikawa I. 
Published: August 2006

Background/aims:  The immunoglobulin G (IgG) antibody response is considered to be protective and beneficial for the control of periodontal lesions. This study analysed IgG subclass antibody levels of Porphyromonas gingivalis in patients with both aggressive periodontitis (AgP) and chronic periodontitis (CP).Methods:  Subgingival plaque and peripheral blood samples were collected from patients with localized AgP (n = 13), generalized AgP (n = 28) and generalized CP (n = 27) and from 14 periodontally healthy controls. P. gingivalis was identified in subgingival pockets using a polymerase chain reaction. Simultaneously, serum IgG subclass antibody against P. gingivalis whole cells/P. gingivalis fimbriae were measured using enzyme‐linked immunosorbent assay.Results:  P. gingivalis was frequently detected in periodontitis patients. Anti‐P. gingivalis whole cell IgG1 was elevated in all P. gingivalis‐positive patients in the three periodontitis groups. Although increased anti‐P. gingivalis IgG1 was also observed in the bacterium‐positive healthy controls, the level was lower than that found in the three periodontitis groups. Levels of IgG1, IgG2, IgG3 and IgG4 to P. gingivalis did not differ among bacterium‐positive patients in the three periodontitis groups; a significant increase of IgG2 level was not observed in localized AgP. Anti‐fimbriae IgG subclass levels of IgG1, IgG2 and IgG4 did not differ among bacterium‐positive subjects in all groups, while the anti‐fimbriae IgG3 level in generalized CP was significantly higher than that in localized and generalized AgP.Conclusions:  P. gingivalis infection elicited an IgG subclass antibody response in both periodontitis patients and healthy subjects, while higher anti‐P. gingivalis IgG1 levels were found in the three periodontitis groups compared with the healthy control group.
Contribution of proteases and plasmin‐acquired activity in migration of Peptostreptococcus micros through a reconstituted basement membrane
Authors: Grenier D. , Bouclin R. 
Published: August 2006

Background/aims:  Peptostreptococcus micros is a gram‐positive bacterium that has been associated with chronic periodontitis and endodontic infections. The aims of this study were to investigate the production of proteases and the acquisition of plasmin activity by rough and smooth morphotypes of P. micros. The contribution of these properties in the migration of bacteria through a reconstituted basement membrane was also evaluated.Methods:  Protease activities were determined using chromogenic and fluorogenic substrates as well as by zymography. Plasminogen binding activity was studied using an enzyme‐linked immunosorbent assay. The role of proteases and plasmin‐acquired activity in tissue penetration was investigated using Matrigel.Results:  The rough morphotype strains of P. micros, but not the smooth morphotype strains, were found to possess chymotrypsin‐like and gelatinase activities, both of which were inhibited by a serine protease inhibitor. By zymography, three gelatinase bands (165, 129, and 115 kDa) were identified. Both morphotypes of P. micros can bind human plasminogen on their cell surface. Once bound to P. micros, plasminogen activators of bacterial (streptokinase) and human (urokinase) origins were found to activate plasminogen into plasmin. Our results also showed that plasmin activity can be acquired by P. micros following co‐incubation with human brain microvascular endothelial cells in culture. When non‐coated cells were used, the rough morphotype strain (HG1262), which possesses chymotrypsin‐like and gelatinase activities, showed a better capacity to penetrate a reconstituted basement membrane (Matrigel) than the smooth morphotype strain (HG1251). Penetration of the Matrigel by P. micros HG1262 was inhibited by the presence of a serine protease inhibitor. In addition, cells of P. micros with plasmin activity showed a significantly greater tissue penetration capacity.Conclusion:  Our study suggests that endogenous proteolytic activities of P. micros as well as plasmin‐acquired activity, may facilitate dissemination of bacterial cells to surrounding periodontal tissues and blood vessels.
Polymerase chain reaction‐based denaturing gradient gel electrophoresis in the evaluation of oral microbiota
Authors: Li Y. , Saxena D. , Barnes V. M. , Trivedi H. M. , Ge Y. , Xu T. 
Published: August 2006

Background/aims:  Clinical evaluation of oral microbial reduction after a standard prophylactic treatment has traditionally been based on bacterial cultivation methods. However, not all microbes in saliva or dental plaque can be cultivated. Polymerase chain reaction‐based denaturing gradient gel electrophoresis (PCR‐DGGE) is a cultivation‐independent molecular fingerprinting technique that allows the assessment of the predominant bacterial species present in the oral cavity. This study sought to evaluate the oral microbial changes that occurred after a standard prophylactic treatment with a conventional oral care product using PCR‐DGGE.Methods:  Twelve healthy adults participated in the study. Pooled plaque samples were collected at baseline, 24 h after prophylaxis (T1), and 4 days after toothbrushing with fluoride toothpaste (T4). The total microbial genomic DNA of the plaque was isolated. PCR was performed with a set of universal bacterial 16S rDNA primers. The PCR‐amplified 16S rDNA fragments were separated by DGGE. The effects of the treatment and of dental brushing were assessed by comparing the PCR‐DGGE fingerprinting profiles.Results:  The mean numbers of detected PCR amplicons were 22.3 ± 6.1 for the baseline group, 13.0 ± 3.1 for the T1 group, and 13.5 ± 4.3 for the T4 group; the differences among the three groups were statistically significant (P < 0.01). The study also found a significant difference in the mean similarities of microbial profiles between the baseline and the treatment groups (P < 0.001).Conclusion:  PCR‐based DGGE has been shown to be an excellent means of rapidly and accurately assessing oral microbial changes in this clinical study.
Does disturbance and restoration of alpine grassland soils affect the genetic structure and diversity of bacterial and N2‐fixing populations?
Authors: Gros Raphaël , Jocteur Monrozier Lucile , Faivre Pierre 
Published: August 2006

SummaryResponses of bacterial communities to disturbance and restoration processes were investigated on alpine grassland soil. Bulk soil, rhizosphere soil and two soil separates, i.e. sand‐size (2000‐200 μm) and silt‐size (50‐2 μm) were sampled from undisturbed grassland soil to soil under restoration for 1 month, 1 year, 4 years and 13 years after disturbance. Automated ribosomal intergenic spacer analysis (ARISA) and restriction fragment length polymorphism (RFLP) of nifH gene pools were used to assay genetic structure of the bacterial communities and N2‐fixing guild. According to the distribution of ARISA band length in bacterial phyla, the dominance of ARISA bands below 400 bp showed that Gram‐positive bacteria would be predominant in the studied grassland soil when not disturbed. Disturbance affected the genetic structure of bacterial community and of N2‐fixing guild in relation to their location within the selected habitats. Shifts in IGS and nifH profiles of bulk soil metagenome were larger than those observed from sand‐size‐ and silt‐size‐fractions, accounting for 40–50% of the variance in the profiles. Restoration of the genetic structure of telluric bacteria community and N2‐fixing populations was found to be influenced by the spatial heterogeneity of the soil and niche diversification. Particular bacterial genetic structure within distinct habitats were evidenced and must be defined as subdivisions of the meta‐community of bulk soil. Scale of soil microbial diversity/stability relationships is discussed with special attention to disconnected bacterial habitat compared with whole soil with multiple niches.
WHAT ARE DESIRES GOOD FOR? TOWARDS A COHERENT ENDORSEMENT THEORY
Authors: Bykvist Krister 
Published: August 2006

AbstractDesire‐based theories of well‐being are often said to accept (G), x is good for a person just in case he wants it, and (B), x is better for a person than y just in case he prefers x to y. I shall argue that (G) and (B) are inconsistent, and this inconsistency resists any plausible refinement of these principles. The inconsistency is brought out by cases in which our wants and preferences for certain life‐options are contingent on which life‐option we realize. My argument can be generalized to endorsement theories that define a person’s good as the right combination of some kind of objective desirability and subjective endorsement, and allow preferences to be tie‐breakers when the compared objects are equally desirable (or incommensurable). My conclusions will not just be negative. I shall argue that if the choice is between (G) and (B), the most attractive option is to keep (G), slightly refined, and drop (B).1
Regression‐based Multivariate Linkage Analysis with an Application to Blood Pressure and Body Mass Index
Authors: Wang T. , Elston R.C. 
Published: August 2006

SummaryMultivariate linkage analysis has been suggested for the analysis of correlated traits, such as blood pressure (BP) and body mass index (BMI), because it may offer greater power and provide clearer results than univariate analyses. Currently, the most commonly used multivariate linkage methods are extensions of the univariate variance component model. One concern about those methods is their inherent sensitivity to the assumption of multivariate normality which cannot be easily guaranteed in practice. Another problem possibly related to all multivariate linkage analysis methods is the difficulty in interpreting nominal p‐values, because the asymptotic distribution of the test statistic has not been well characterized. Here we propose a regression‐based multivariate linkage method in which a robust score statistic is used to detect linkage. The p‐value of the statistic is evaluated by a simple and rapid simulation procedure. Theoretically, this method can be used for any number and type of traits and for general pedigree data. We apply this approach to a genome linkage analysis of blood pressure and body mass index data from the Beaver Dam Eye Study.
Variation of Estimates of SNP and Haplotype Diversity and Linkage Disequilibrium in Samples from the Same Population Due to Experimental and Evolutionary Sample Size
Authors: Visscher P. M. 
Published: August 2006

SummaryStudies of genetic polymorphisms and diversity between and within human populations are increasingly characterised by a very large number of genetic markers but using a relatively small number of individuals from which DNA samples were taken. In this report we examine the limitations of a small experimental sample size relative to a large genomic sample size, and quantify the sampling variance of a number of measures of diversity and linkage disequilibrium. The relationship between sample size and observed levels of polymorphism and haplotype diversity at the level of a gene is investigated under a neutral model of sequence evolution, using coalescent simulations. It is shown that the effect of evolutionary sampling, as manifested by differences between samples (genes) in measures of diversity estimated using very large sample sizes, is substantial, with a coefficient of variation of the number of detected polymorphic SNPs or haplotypes in the order of 15%. The effect of experimental design (sample size) is also very large, and a number of ‘significant’ results reported in the literature can be explained by sampling alone. The expected correlation coefficient of measures of linkage disequilibrium across samples from the same population has been quantified and found to be consistent with empirical estimates from the literature.
A Two‐Stage Approach to the Correction of Ascertainment Bias in Complex Genetic Studies Involving Variance Components
Authors: Bowden J. , Thompson J. R. , Burton P. R. 
Published: August 2006

SummaryCorrection for ascertainment bias is a vital part of the analysis of genetic epidemiology studies that needs to be undertaken whenever subjects are not recruited at random. Adjustment often requires extensive numerical integration, which can be very slow or even computationally infeasible, especially if the model includes many fixed and random effects. In this paper we propose a two‐stage method for ascertainment bias correction. In the first stage we estimate parameters that pertain to the ascertained population, that is the population that would be selected into the sample if the ascertainment criterion were applied to everyone. In the second stage we convert the estimates for the ascertained population into general population parameter estimates. We illustrate the method with simulations based on a simple model and then describe how the method can be used with complex models. The two‐stage approach avoids some of the integration required in direct adjustment, hence speeding up the process of model fitting.
The Fate of 12 Recessive Mutations in A Single Village
Authors: Zlotogora J. , Hujerat Y. , Barges S. , Shalev S. A. , Chakravarti A. 
Published: August 2006

SummaryIn a Muslim Arab village, relatively isolated because of the preference of consanguineous marriages, we studied the fate of 12 mutations in 5 different genes. The study was based on carriers detected among relatives of affected patients and of carriers discovered in a random sample of 424 adults.Most of the mutations have been introduced by a carrier(s) originating from another village, but a few have been de novo events. Mutations that are very frequent in the entire village were introduced soon after the foundation of the village. Examples of such mutations are [GBJ2, 35Gdel] and [MEFV, M680I], with a carrier frequency of 7.8% and 6.2%, respectively. Many of the other mutations that are rare were introduced recently into the village and are frequent only among the descendants of the first couple carrying the mutation. For instance all the carriers of [ARSA, Q190H], responsible for metachromatic leukodystrophy, were found among the 218 descendants of a couple who were living in the village 4 generations ago.Since the village is typical for the region this study allows for some general conclusions to be drawn. In a population with a high degree of inbreeding the diagnosis of a single family with a patient(s) affected with a recessive disorder points to a recent event, while the finding of a rare disease in several families from an inbred population points to an older mutation. Mutations are often “exported” from one population to another by marriage. In the new inbred population this novel mutation will either be lost or will become frequent as the result of a founder effect. These observations are important for genetic counselling in the case of a recent mutation, since only the descendants of the founder couple are at risk, while in the case of older mutations the risk may be for the entire village. In the case of those frequent ancient mutations, the risk for a relative of an affected individual will be similar whether he marries a close relative or any random individual in the village.
Dissecting the Genetic History of São Tomé e Príncipe: A New Window from Y‐Chromosome Biallelic Markers
Authors: Trovoada M.J. , Tavares L. , Gusmão L. , Alves C. , Abade A. , Amorim A. , Prata M.J. 
Published: August 2006

SummaryTwenty biallelic Y chromosome markers were analyzed in Angolares, Forros and Tongas, three population groups from the African archipelago of São Tomé e Príncipe. While most male lineages belonged to sub‐Saharan haplogroups, the component of European origin added up 23.9% in the archipelago. This contrasts with the reported absence of European mtDNA lineages, and the combined findings testify to a strong sex‐biased admixture process during the long‐lasting colonial period in São Tomé e Príncipe. Furthermore, the male mediated European component was clearly found to be out of proportion to the small demographic impact of the Portuguese on the islands, reflecting high variance in the reproductive success of the individuals that contributed to its peopling.The male portion of European ancestry was 33.3% in Forros, 27.3% in Tongas and approximately two‐fold less, 14.5%, in Angolares. The Angolares also showed the lowest haplogroup diversity and the most reduced number of different haplogroups. The current results reinforce our previous evidence pointing to remarkable restrictions in gene flow between Angolares and other São Tomean inhabitants, in agreement with their considerable isolation and confinement to the south‐eastern tip of São Tomé until recently.
Effects of perceptual load on startle reflex modification at a long lead interval
Authors: Thorne Gary L. , Dawson Michael E. , Schell Anne M. 
Published: August 2006

AbstractInhibition of the startle eyeblink response at long lead intervals has been hypothesized to occur when attention is directed away from the modality of the startle stimulus, particularly if attention is directed to a stimulus of high perceptual load. In a test of this hypothesis, participants performed a delayed‐matching‐to‐sample task. On each trial a pattern of dots (the sample) was followed by a second pattern of dots (the target). The task was to say whether the sample and target patterns matched. Perceptual load was manipulated by varying the number of dots in the sample. Auditory startle stimuli were presented 1200 ms after onset of the samples. A linear increase in startle magnitude was found as the number of dots increased. The results are not consistent with the hypothesis that startle inhibition occurs when the lead and startle stimuli are in different modalities under conditions of high perceptual load.
Association between P3 event‐related brain potential amplitude and adolescent problem behavior
Authors: Iacono William G. , McGue Matt 
Published: August 2006

AbstractThis study examined P3 event‐related brain potential amplitude and the age of onset of adolescent problem behaviors associated with the development of externalizing psychopathology. Five hundred and one male and 627 female 17‐year‐old twins reported whether and when they had initiated tobacco, alcohol, or illicit drug use, had police contact, or had sexual intercourse. P3 amplitude was recorded using a visual oddball task. Each of these behaviors was associated with reduced P3 amplitude. When these five behaviors were used to create a composite early problem behavior scale reflecting onset prior to age 15, higher scores were associated with smaller P3 amplitudes. P3 amplitude reduction has been associated with genetic risk for alcoholism and other externalizing disorders associated with disinhibited behavior. Our results suggest that reduced P3 may also be associated with early expression of behaviors that predict the development of these disorders.
Preattentively grouped tones do not elicit MMN with respect to each other
Authors: Ritter Walter , De Sanctis Pierfilippo , Molholm Sophie , Javitt Daniel C. , Foxe John J. 
Published: August 2006

AbstractTo promote preattenive grouping of two sets of tones, one set of tones with a combination of frequency and ear of delivery was intermixed with another set of tones with a different combination of frequency and ear of delivery. The ERPs elicited by tones delivered to one ear that were preceded by three or four tones delivered in a row to the other ear were associated with an enhanced N1, due to the changes in frequency and ear of delivery with respect to the immediately preceding tones. However, no mismatch negativity (MMN) was obtained, even though these tones differed from the previious tones on the two dimensions of frequency and ear of delivery. The data were interpreted to signify that preattentively grouped sets of tones do not elicit MMN with respect to one another. This implies that once acoustic input has been preattentively grouped, the MMN system is dedicated to detecting changes that occur within but not between preattentively grouped stimuli.