An effective technique to posterior resin composite restorations

AIM: The aim of this study is to present a clinical case in which an occlusal matrix device was used in a patient who needed to restore a posterior tooth. MATERIAL AND METHODS: A direct duplicate occlusal appliance was used (biteperf) in a patient who needed an occlusal restoration in two posterior teeth. RESULTS: Using the matrix helps having fast and accurate reproduction of the original anatomical details of the occlusal surface. The final result surprised with the presented restoration in terms of esthetic quality, despite the simplicity of the technique. CONCLUSION: Posterior teeth with initial lesions were confined to the occlusal surface of anatomically complex or fissured anatomy with or without signs of proximal caries wich are ideal candidates for this technique. The overlying enamel surface must be relatively intact; lesions of hidden or occult caries. CLINICAL SIGNIFICANCE: The aesthetic and time-saving benefits of the occlusal device (biteperf) are immediately clear. The matrix allows the fast and accurate reproduction of the anatomic details of the original occlusal surface of the tooth. The professionals who lack an artistic penchant and marked manual ability will be able to carry out excellent posterior resin composite restorations.

Influência das variações pluviais nos teores de flúor em águas de poços

Introduction: The fluoridation surveillance in the public water supply came up with the need to develop mechanisms that would help society in the control of water quality. To perform reliable analysis, variables such as depth of the wells and pluvial variations should be subject of research and study. Objectives: To analyze the fluoride levels of deep wells in periods of rain and drought, corresponding to four brazilian cities and compare the results. Methodology: It was made the mapping of the water supply network and the identification of the sampling points according to the number of deep wells in each locality, selecting those who had the natural fluoride level. Three points were defined for each source of water supply, and the addresses were randomly selected. The samples were analyzed in duplicate at the laboratory of the Center for Research in Public Health of the Dentistry School of Araçatuba – UNESP, during 8 months, in periods of rain and drought (total absence of rain). Results: 174 analysis were conducted, the mean fluoride levels for rain and drought times were, respectively: 0,71 and 0,73. It was used the Student’s t test (p <0.05). Conclusion: There wasn’t statistically significant differences for the periods of rain and drought in any of the cities, at the year of 2010. This study highlights the importance of health surveillance, because beyond of ensuring social control, there is also the search for investigating variables that may have directly and / or indirectly influence on the results of the analysis.

Fluoretação das águas de abastecimento público em um município com diferentes fontes de captação

Maintaining the levels of fluoride ion in public water supply within the parameters of adequacy it becomes essential so the measure carries a greater impact on caries prevention and control, without increasing the prevalence of dental fluorosis. Thus, it is necessary a rigorous control of the process, avoiding the undesired effects at levels above recommended levels, as well as avoiding levels below the recommended that do not offer the highest benefit. The aim of this study was to analyze the content of fluoride in public water supply in the city of Birigui, SP, with different sources of supply, checking if the fluoride levels are within the recommended. The samples were collected monthly from points previously established, with the knowledge of the distribution network of water and identifying the amount and location of supply sources and water treatment plant. Analyses were performed in duplicate in the period from January to December of 2009, in the laboratory - NEPESCO - of the Dental School of Araçatuba, Univ Estadual Paulista – UNESP, using an ion analyzer coupled to a specific electrode for fluoride. Of the total samples (n = 512), 44% (n = 224) had adequate levels and 56% (n = 288) inadequate levels, 10% (n = 49) lower levels and 46% (n = 239) showed levels above the recommended. There were differences in results when comparing the analysis of different sources. The fluoride concentration in the majority of the samples from deep wells was classified as inadequate not offering the desired benefit, or exposing the population to the risk of dental fluorosis.

Fluoretação das águas de abastecimento público no município de Araçatuba/SP

Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP)

Concentração de flúor em águas envasadas: análise laboratorial e da legislação relacionada

Fluoridation of water for human consumption is a method of caries prevention that brings great social benefit, if kept at optimal levels. The increase in the production of bottled water emphasizes the need to verify whether fluoride presence in these waters occurs in sufficient quantity to prevent decay, or if it represents a significant risk of fluorosis. Objective: to compare the concentrations of fluoride present in bottled water to those declared on the labels, and to make a critical analysis of legal norms on the subject. Materials and method: this was a cross-sectional study, through which 22 samples of bottled water sold in state of Ceará, Brazil, were analyzed. Analyses were performed in duplicate by the electrometric method, and results were compared to those printed on the labels. Detailed searches by laws, resolutions, ordinances, and other official documents in force, related to the topic were performed. Results: the fluoride concentrations found ranged from 0.01 to 0.36 mgF/l. Although 72.7% of the samples were classified as fluoridated, the fluoride concentrations observed were shown to be insufficient for caries prevention. As for the rules, situations where they are not clear or even divergent were found. Conclusion: the current legislation on the subject requires updates to become more objective and to create new criteria on the use of the term “fluoridated water”.

Monitoramento da composição isotópica e físico-química da água de chuva no município de Rio Claro (SP)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo da reação de dissolução de serpentinitos brasileiros para uso em processo de captura de carbono

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Improving IRT parameter estimates with small sample sizes: Evaluating the efficacy of a new data augmentation technique

The 3PL model is a flexible and widely used tool in assessment. However, it suffers from limitations due to its need for large sample sizes. This study introduces and evaluates the efficacy of a new sample size augmentation technique called Duplicate, Erase, and Replace (DupER) Augmentation through a simulation study. Data are augmented using several variations of DupER Augmentation (based on different imputation methodologies, deletion rates, and duplication rates), analyzed in BILOG-MG 3, and results are compared to those obtained from analyzing the raw data. Additional manipulated variables include test length and sample size. Estimates are compared using seven different evaluative criteria. Results are mixed and inconclusive. DupER augmented data tend to result in larger root mean squared errors (RMSEs) and lower correlations between estimates and parameters for both item and ability parameters. However, some DupER variations produce estimates that are much less biased than those obtained from the raw data alone. For one DupER variation, it was found that DupER produced better results for low-ability simulees and worse results for those with high abilities. Findings, limitations, and recommendations for future studies are discussed. Specific recommendations for future studies include the application of Duper Augmentation (1) to empirical data, (2) with additional IRT models, and (3) the analysis of the efficacy of the procedure for different item and ability parameter distributions.

Birth prevalence and characteristics of congenital toxoplasmosis in Sergipe, North-east Brazil

Objectives To estimate, by neonatal screening, the birth prevalence of congenital toxoplasmosis among live-born infants in Sergipe state, Brazil, and to investigate the clinical features of affected infants. Methods Dried blood spot specimens obtained from 15 204 neonates were assayed for the presence of anti-T. gondii IgM antibodies. Duplicate retesting was done in infants with positive and borderline results. Confirmatory testing in peripheral blood samples consisted of testing for anti-T. gondii IgG and IgM in infants and mothers. Those with possible congenital toxoplasmosis were evaluated and followed up to a median age of 20 months. Congenital infection was confirmed in the presence of persisting anti-T. gondii IgG antibodies beyond 12 months of age. All infants with confirmed infection were treated with pyrimethamine, sulfadiazine and folinic acid for 1 year. Results Fifty-three infants had detectable IgM in dried blood spot specimens. Confirmatory testing was reactive in 39/50, of which, 38 completed follow-up. Six of 15 204 newborns were diagnosed with congenital toxoplasmosis, resulting in an estimated birth prevalence of four per 10 000 [CI 95% 1.48.0]. Four infants (67%) showed signs of congenital toxoplasmosis in their first year of life; three (75%) had retinochoroidal scars, and one had cerebral calcifications. Two infants remained asymptomatic until 20 months of age. Conclusions The birth prevalence of congenital toxoplasmosis is high in the Brazilian state of Sergipe, with most of the infants showing ocular lesions. Preventive measures are strongly warranted.

Efficient RNAi-induced Protein Knockdown in Somatic Cells Using Diced or Chemically Produced Small Interfering RNAs (siRNA)

Background: RNA interference (RNAi) is a post-transcriptional gene silencing process in which double-stranded RNA (dsRNA) directs the degradation of a specific corresponding target mRNA. The mediators of this process are small dsRNAs of approximately 21 to 23 bp in length, called small interfering RNAs (siRNAs), which can be prepared in vitro and used to direct the degradation of specific mRNAs inside cells. Hence, siRNAs represent a powerful tool to study and control gene and cell function. Rapid progress has been made in the use of siRNA as a means to attenuate the expression of any protein for which the cDNA sequence is known. Individual siRNAs can be chemically synthesized, in vitro-transcribed, or expressed in cells from siRNA expression vectors. However, screening for the most efficient siRNAs for post-transcriptional gene silencing in cells in culture is a laborious and expensive process. In this study, the effectiveness of two siRNA production strategies for the attenuation of abundant proteins for DNA repair were compared in human cells: (a) the in vitro production of siRNA mixtures by the Dicer enzyme (Diced siRNAs); and (b) the chemical synthesis of very specific and unique siRNA sequences (Stealth RNai (TM)). Materials, Methods & Results: For in vitro-produced siRNAs, two segments of the human Ku70 (167 bp in exon 5; and 249 bp in exon 13; NM001469) and Xrcc4 (172 bp in exon 2; and 108 bp in exon 6; NM003401) genes were chosen to generate dsRNA for subsequent "Dicing" to create mixtures of siRNAs. The Diced fragments of siRNA for each gene sequence were pooled and stored at -80 degrees C. Alternatively, chemically synthesized Stealth siRNAs were designed and generated to match two very specific gene sequence regions for each target gene of interest (Ku70 and Xrcc4). HCT116 cells were plated at 30% confluence in 24- or 6-well culture plates. The next day, cells were transfected by lipofection with either Diced or Stealth siRNAs for Ku70 or Xrcc4, in duplicate, at various doses, with blank and sham transfections used as controls. Cells were harvested at 0, 24, 48, 72 and 96 h post-transfection for protein determination. The knockdown of specific targeted gene products was quantified by Western blot using GAPDH as control. Transfection of gene-specific siRNA to either Ku70 or Xrcc4 with both Diced and Stealth siRNAs resulted in a down regulation of the targeted proteins to approximately 10 to 20% of control levels 48 h after transfection, with recovery to pre-treatment levels by 96 h. Discussion: By transfecting cells with Diced or chemically synthesized Stealth siRNAs, Ku70 and Xrcc4, two highly expressed proteins in cells, were effectively attenuated, demonstrating the great potential for the use of both siRNA production strategies as tools to perform loss of function experiments in mammalian cells. In fact, down-regulation of Ku70 and Xrcc4 has been shown to reduce the activity of the non-homologous end joining DNA pathway, a very desirable approach for the use of homologous recombination technology for gene targeting or knockout studies. Stealth RNAi (TM) was developed to achieve high specificity and greater stability when compared with mixtures of enzymatically-produced (Diced) siRNA fragments. In this study, both siRNA approaches inhibited the expression of Ku70 and Xrcc4 gene products, with no detectable toxic effects to the cells in culture. However, similar knockdown effects using Diced siRNAs were only attained at concentrations 10-fold higher than with Stealth siRNAs. The application of RNAi technology will expand and continue to provide new insights into gene regulation and as potential applications for new therapies, transgenic animal production and basic research.

Remarks on the classification of a pair of commuting semilinear operators

Gelfand and Ponomarev [I.M. Gelfand, V.A. Ponomarev, Remarks on the classification of a pair of commuting linear transformations in a finite dimensional vector space, Funct. Anal. Appl. 3 (1969) 325-326] proved that the problem of classifying pairs of commuting linear operators contains the problem of classifying k-tuples of linear operators for any k. We prove an analogous statement for semilinear operators. (C) 2011 Elsevier Inc. All rights reserved.

Real-time PCR quantitation of glucocorticoid receptor alpha isoform

Abstract Background The expression of glucocorticoid-receptor (GR) seems to be a key mechanism in the regulation of glucocorticoid (GC) sensitivity and is potentially involved in cases of GC resistance or hypersensitivity. The aim of this study is to describe a method for quantitation of GR alpha isoform (GRα) expression using real-time PCR (qrt-PCR) with analytical capabilities to monitor patients, offering standard-curve reproducibility as well as intra- and inter-assay precision. Results Standard-curves were constructed by employing standardized Jurkat cell culture procedures, both for GRα and BCR (breakpoint cluster region), as a normalizing gene. We evaluated standard-curves using five different sets of cell culture passages, RNA extraction, reverse transcription, and qrt-PCR quantification. Intra-assay precision was evaluated using 12 replicates of each gene, for 2 patients, in a single experiment. Inter-assay precision was evaluated on 8 experiments, using duplicate tests of each gene for two patients. Standard-curves were reproducible, with CV (coefficient of variation) of less than 11%, and Pearson correlation coefficients above 0,990 for most comparisons. Intra-assay and inter-assay were 2% and 7%, respectively. Conclusion This is the first method for quantitation of GRα expression with technical characteristics that permit patient monitoring, in a fast, simple and robust way.

Development and validation of a Xanthomonas axonopodis pv. citri DNA microarray platform (XACarray) generated from the shotgun libraries previously used in the sequencing of this bacterial genome

Abstract Background From shotgun libraries used for the genomic sequencing of the phytopathogenic bacterium Xanthomonas axonopodis pv. citri (XAC), clones that were representative of the largest possible number of coding sequences (CDSs) were selected to create a DNA microarray platform on glass slides (XACarray). The creation of the XACarray allowed for the establishment of a tool that is capable of providing data for the analysis of global genome expression in this organism. Findings The inserts from the selected clones were amplified by PCR with the universal oligonucleotide primers M13R and M13F. The obtained products were purified and fixed in duplicate on glass slides specific for use in DNA microarrays. The number of spots on the microarray totaled 6,144 and included 768 positive controls and 624 negative controls per slide. Validation of the platform was performed through hybridization of total DNA probes from XAC labeled with different fluorophores, Cy3 and Cy5. In this validation assay, 86% of all PCR products fixed on the glass slides were confirmed to present a hybridization signal greater than twice the standard deviation of the deviation of the global median signal-to-noise ration. Conclusions Our validation of the XACArray platform using DNA-DNA hybridization revealed that it can be used to evaluate the expression of 2,365 individual CDSs from all major functional categories, which corresponds to 52.7% of the annotated CDSs of the XAC genome. As a proof of concept, we used this platform in a previously work to verify the absence of genomic regions that could not be detected by sequencing in related strains of Xanthomonas.

Seven years of external control of fluoride levels in the public water supply in Bauru, São Paulo, Brazil

Fluoridation of the public water supplies is recognized as among the top ten public health achievements of the twentieth century. However, the positive aspects of this measure depend on the maintenance of fluoride concentrations within adequate levels. To report the results of seven years of external control of the fluoride (F) concentrations in the public water supply in Bauru, SP, Brazil in an attempt to verify, on the basis of risk/benefit balance, whether the levels are appropriate. From March 2004 to February 2011, 60 samples were collected every month from the 19 supply sectors of the city, totaling 4,641 samples. F concentrations in water samples were determined in duplicate, using an ion-specific electrode (Orion 9609) coupled to a potentiometer after buffering with TISAB II. After the analysis, the samples were classified according to the best risk-benefit adjustment. Means (±standard deviation) of F concentrations ranged between 0.73±0.06 and 0.81±0.10 mg/L for the different sectors during the seven years. The individual values ranged between 0.03 and 2.63 mg/L. The percentages of the samples considered “low risk” for dental fluorosis development and of “maximum benefit” for dental caries prevention (0.55-0.84 mg F/L) in the first, second, third, fourth, fifth, sixth, and seventh years of the study were 82.0, 58.5, 37.4, 61.0, 89.9, 77.3, and 72.4%, respectively, and 69.0% for the entire period. Fluctuations of F levels were found in the public water supply in Bauru during the seven years of evaluation. These results suggest that external monitoring of water fluoridation by an independent assessor should be implemented in cities where there is adjusted fluoridation. This measure should be continued in order to verify that fluoride levels are suitable and, if not, to provide support for the appropriate adjustments

Gastroesophageal reflux, dental erosion, and halitosis in epidemiological surveys: a systematic review

In published studies, it has been suggested that dental wear is associated with gastroesophageal reflux disease (GERD). This systematic review was carried out to evaluate the association of GERD, dental erosion, and halitosis and to compare the indices adopted in epidemiological surveys. The Medline database (until October, 2011) was searched systematically to identify studies evaluating the prevalence of oral alterations, such as dental erosion and halitosis, in patients with GERD symptoms. Two reviewers analyzed all reports and the selected studies were evaluated according to the quality of evidence, using the validated Newcastle–Ottawa Quality Assessment Scale. Full-text copies of a total of 32 publications were obtained in duplicate. Sixteen publications were identified among the citations in the Bibliographic lists of studies that fulfilled the exclusion/inclusion criteria and quality of evidence. The relationship between dental erosion and GERD patients was significant in only seven studies. According to three studies, halitosis could be one of several extraesophageal symptoms or manifestations in GERD patients. In one study, it was found that the mucosa of GERD patients was significantly more acidic in comparison with that of the control group. This systematic review showed that there is a relationship between GERD and oral diseases (dental erosion and halitosis). The epidemiological surveys used different indices to analyze GERD and dental erosion. Further research could investigate the best method for assessing the two diseases.