Association between clinical expression and molecular heterogeneity in ß-thalassemia Tunisian patients.

Beta-thalassemia is the most frequent hereditary blood disorder in Tunisia because of its geographic localization and history. This pathology is characterized by a complex multisystem process with genetic and biochemical interactions. The aim of this work was to establish phenotype/genotype association through studying the distribution and the relationship between ß-thalassemia and α-thalassemia mutations and three polymorphic markers: the C → T polymorphism at -158 of the Gγ gene, the RFLP haplotype and the repeated sequence (AT)xTy in the ß globin silencer, in two groups of ß-thalassemia major and ß-thalassemia intermedia (TI) patients. Statistical analysis has shown that moderate expression seen in TI patients was significantly associated to ß(+) -87 (C → G), -30 (T → A) and IVSI-6 (T → C) mutations, haplotypes VIII, IX and Nb and to XmnI polymorphism. The regression analysis of combined genotypes (mutation/XmnI/RFLP haplotype) revealed that they contribute to justify 17.1 % of clinical expression diversity (p < 0.05). Among the studied genotypes the XmnI polymorphism seems to be the most determinant modulating factor, followed by the ß-thalassemia mutation and RFLP haplotype. Our findings highlight the heterogeneity of molecular background of ß-thalassemia that would be responsible of clinical variability.

Glucose-6-phosphate dehydrogenase deficiency in Tunisia: molecular data and phenotype-genotype association.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect. In this study, we aimed to perform a molecular investigation of G6PD deficiency in Tunisia and to associate clinical manifestations and the degree of deficiency with the genotype. A total of 161 Tunisian subjects of both sexes were screened by spectrophotometric assay for enzyme activity. Out of these, 54 unrelated subjects were selected for screening of the most frequent mutations in Tunisia by PCR/RFLP, followed by size-based separation of double-stranded fragments under non-denaturing conditions on a denaturing high performance liquid chromatography system. Of the 56 altered chromosomes examined, 75 % had the GdA(-) mutation, 14.28 % showed the GdB(-) mutation and no mutations were identified in 10.72 % of cases. Hemizygous males with GdA(-) mutation were mostly of class III, while those with GdB(-) mutation were mainly of class II. The principal clinical manifestation encountered was favism. Acute hemolytic crises induced by drugs or infections and neonatal jaundice were also noted. Less severe clinical features such as low back pain were present in heterozygous females and in one homozygous female. Asymptomatic individuals were in majority heterozygote females and strangely one hemizygous male. The spectrum of mutations seems to be homogeneous and similar to that of Mediterranean countries; nevertheless 10.72 % of cases remain with undetermined mutation thus suggesting a potential heterogeneity of the deficiency at the molecular level. On the other hand, we note a better association of the molecular defects with the severity of the deficiency than with clinical manifestations.

Actualización en endodoncia 2010 / 2010 Update in Endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2010, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published in the most relevant journals concerning endodontics during the last year 2010, making a comparison between them, as well as with other older one and with classic concepts in endodontics (AU)

Minor histocompatibility antigens in Tunisians: could platelet endothelial cell adhesion molecule 1 marker be one of them?

Platelet endothelial cell adhesion molecule 1 (PECAM-1/CD31) is one of the human minor histocompatibility antigens that are the main targets of alloreactive T-cells after hematopoietic stem cells or solid organs transplantation. In order to investigate its polymorphism in Tunisians, three single nucleotide polymorphisms (SNPs) (rs668, rs12953 and rs1131012) were selected to perform an allele and haplotype analysis. Hundred-and-forty-two healthy and unrelated subjects were enrolled in this survey. Genomic DNAs were extracted using salting out method. SNP genotyping assays were performed with home-designed sequence-specific primers polymerase chain reaction (SSP-PCR). As a result, molecular analysis showed that PECAM-1 is one of the most polymorphic markers in the Tunisian population because minor allele frequency was 0.3, and minimum haplotype frequency was 0.03. A low linkage disequilibrium (D' = 0.45) between rs12953 and rs1131012 was noticed, although all other loci were in the Hardy-Weinberg equilibrium (minimum P value = 0.07). The frequencies were close to those reported in African-American and Caucasian groups.

Acutalización en Endodoncia 2009 / 2009 Update in Endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2009, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published int he most relevant journals concerning endodontics during the last year 2009, making a comparison between them, as well as with other older ones and with classic concepts in endodontics (AU)

[Integration processes and clinical governance in the psychiatric network]. / Processus intégratifs et gouvernance clinique dans la psychiatrie institutionnelle.

The Swiss Medical Insurance Act (LAMaL) requires the planning of psychiatric care. This necessitates a coordination between the Department of Public Health and the institutional governance. Given the difficulties to draw comparisons between a wide range of systems in a federal country, the Swiss Conference of the State Directors of Health (CDS) proposed as a first step that each canton present some of the key programs they had developed. In the canton Vaud, the implementation of mobile community treatment teams and of an early intervention program for psychosis was chosen. The main challenges faced were to go past traditional divides within the organisation of the Swiss Health system and to conciliate the requirements of public health with the needs of treating teams, in order to promote early intervention in mental health disorders.

Actualización en endododoncia 2008 / 2008 Update in endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2008, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the article published in the most relevant journals concerning endodontics during the last year 2008, making a comparison between them, as well as with other older ones and with classic conepts in endodontics (AU)

Actualización en Endodoncia 2007 / 2007 Update in Endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2007 comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published in the most relevant journals concerning endodontic during the last year 2007, making a comparison between them as well as with other older ones and with classic concepts in endodontics (AU)

Evaluación del porcentaje de material núcleo en conductos radiculares obturados con puntas de gutapercha y de Real Seal de distintas conicidades / No disponible

Objetivo. El objetivo del presente estudio fue evaluar el porcentaje de material núcleo en conductos radiculares de dientes monorradiculares obturados mediante compactación lateral y puntas de gutapercha o de Real Seal de conicidades del 2% y 4% junto con un sellador. Materal y métodos. Se emplearon 40 conductos de dientes compactación lateral en frío. Se formaron al azar cuatro grupos de diez especímenes cada uno: Grupo A (punta de gutapercha conicidad 2% y Topseal); Grupo B(punta de gutapercha conicidad 4% y Topseal); Grupo C (puntas de Real Seal conicidad 2% y su cemento); Grupo D (puntas de Real Seal conicidad 4% y su cemento). Transcurridas 48 horas se efectuaron cortes transversales de las raíces a 2,4 y 5 mm del ápice. Se observaron mediante un estereomicroscopio, efectuando fotografías de cada corte, se digitalizaron y mediante un programa informático se evaluó el porcentaje que ocupaba el material núcleo respecto al área total de la sección del conducto. Resultados. No se observaron diferencias significativas entre todos los grupos, solo en las comparaciones de dos a dos en tres subgrupos. Conclusiones. Bajo las condiciones de nuestro estudio, no hallarnos diferencias significativas en cuanto al porcentaje de material núcleo respecto al total del área de la sección de conductos obturados mediante de gutapercha o Real Seal de conicidades 2% y 4% (AU)

Aim. The aim of this study was to assess the percentage of core material in foot canals of single-rooted tech filling by lateral compaction, gutta percha or Real Seal points .02 and .04 tuper and sealer. Material an d methods. Forty extrated anterior maxilary teeth were used. The root canals were prepared in a crown-down rotary technique to a size 30/04. The filling technique was cold lateral compaction. The roots were randonly divided in four groups of ten roots each. Group A(gutta-percha paints .02 taper and Topseal); Group B(gutta-percha points .04taper and Topseal); Group C (Real Seal points .02 taper and their sealer); Group D (Reni Seal points .04 taper and their sealer). After 48 hours horizontal sections were cut 2,4 and 6 mm form the apex. The area of the canal, core material and sealer and voids were measured using an image analysis program. Results. No significant differences between any of the groups were found. Significant differences were found when comparisons were made between two suit groups in three cases. Conclusions. Within the limitations of this study no significant differences were found in the percentage of the core material from the total area of the section of canal filling with gutta-percha or Real Seal pints taper .02 and .04 (AU)

Actualización en endodoncia 2006 / No disponible

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2006, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published in the most relevant journals concerning endodontics during the last year 2006, making a comparison between them, as well other older ones and with classic concepts in endodontics (AU)

Procesos endoperiodontales. I. Bases biológicas e interrelaciones / Endoperiodontal pathology. I. Biologic basis

Las relaciones endoperiodontales siguen siendo un tema de actualidad sujeto a controversia. Se analizan sus características macro y microscópicas así como la interrelación entre la patología pulpar y periodontal

Nowadays, the endoperiodontal relationships are still a present time theme that is subject to controversy. Their macro and microscopic features are analysed as well as the relationship between the pulp pathology and the periodontal disease

Actualización en endodoncia 2005 / 2005 update in endodontics2

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2005, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia

The authors review the articles published inthe most relevant journals concerning endodontics during the last years 2005, making a comparison between them, as well as with other ones and with classic concepts in endodontics

Estudio comparativo de la cavidad de acceso radicular en conductos curvos con limas de níquel-titanio y taladros de acero inoxidable / Comparative study between gates glidden and niquel-titanium rotary files preflaring

El propósito de este estudio fue comparar la cantidad de dentina radicular removida y evaluar el mantenimiento de la forma del conducto tras la instrumentación de los dos tercios coronarios radiculares, utilizando instrumentos de acero inoxidable (taladros de Gates Glidden) y de níquel-titanio (limas GT Flare y limas Orifice Shaper). Un total de 42 dientes humanos extraídos con conductos radiculares curvos fueron divididos en tres grupos. Los conductos se instrumentaron mecánicamente usando taladros de Gates Glidden, limas Orifice Shaper o GT Flare con la técnica corono-apical. Este estudio se realizó siguiendo la técnica de Bramante modificada. Las secciones transversales de cada conducto fueron efectuadas a tres niveles horizontales diferentes (a 2, 4 y 6mm de su inicio en la cámara). Antes y después de la instrumentación fueron observados y fotografiados para luego ser medidos. A cada nivel se valoraron dos parámetros, el mantenimiento de la forma original del conducto y la cantidad de dentina removida. El análisis estadístico reveló que existían diferencias estadísticamente significativas (p<0,05) a, nivel de los cortes a 4 y 6 mm en la cara interna del conducto; mientras que la preparación del mismo más prevalente fue excéntrica sin ensanchar todas las paredes del conducto

The purpose of this study was to compare the amount of the dentine removed and to evaluate the maintenance of the original shape of root canals after the filing of two thirds coronary root canals using instruments of stainless-steel (Gates Glidden drills) and nickel-titanium (GT Flare and Orifice Shaper files). A total of forty-two extracted human teeth with curved root canals were divided in three groups. They were instrumented mechanically using Gates Glidden drills, Orifice Shaper files or GT Flare files with the crown-down technique. This study was done following the modified Bramante technique. The crossed sections of every root canal were done at three different levels (at 2, 4 and 6mm from pulp chamber). Before and after the filing process, these sections were photographed to be mesured. Two parameters were evaluated in every section, the maintenance of the original of the root canal shape and the amount of dentine removed. Statistical analysis revealed significant differences (p<0,05) between the crossed sections at 4 and 6mm in the inner face; while the excentric shapes, without widen all canal walls, was the most frequent

Study of dentinal tubule architecture of permanent upper premolars: evaluation by SEM.

Dentinal tubules are the means by which the pulp and mineralised tissues surrounding the dentine (enamel and cementum) communicate. Through these tubules external agents can damage the pulp and subsequently the periodontal ligament. Given the importance of dentinal tubules, the authors evaluated the numerical density, shape, and individual surface area of tubule openings and the percentage of dentine occupied by these. Eight permanent upper premolars were studied using scanning electron microscopy (SEM). In the crown, the external surface of the dentine was evaluated at the dentino-enamel junction and the internal surface at the pulp chamber wall. At the cervical, middle and apical thirds of the root, the external surface was evaluated at the cemento-dentinal junction and the internal surface at the root canal wall. The results showed that numerical density of tubule openings is significantly greater (p < 0.05) at the cervical third of the dentine, at its junction with the cementum and at the pulpal chamber wall, with respect to other areas evaluated. The individual surface area of each opening varied from 5.72 microns 2 in the dentine of the pulpal chamber wall to 0.97 micron 2 in the dentine of the apical third of the root canal wall. The percentage of area occupied by the dentinal tubules per mm2 of dentine was significantly higher (p < 0.01) at the internal dentinal surface as compared to the external. The shape of the tubule openings was found to be circular in the crown and became more irregular as the apical third of the root was approached.

The effect of sterilization on bending and torsional properties of K-files manufactured with different metallic alloys.

The purpose of this study was to assess the effect of dry-heat or autoclave sterilization on the resistance to fracture in torque and angular deflection and the resistance to bending of K-type files made of nickel-titanium (Nitiflex, Naviflex), titanium (Microtitane) or stainless steel (Flexofile, Flex-R). Ten K-type files of each sort, from size 25 to 40, were tested, according to ANSI/ADA specification 28 (1988) and ISO specification 3630 (1992). Sterilization with dry heat and autoclave slightly decreased the flexibility of files made of stainless steel and nickel-titanium for most of the sizes, although the values obtained satisfied ISO specifications. The files made of titanium showed an increased flexibility after sterilization with autoclave (sizes 30 and 35) and dry heat (sizes 30, 35 and 40). Resistance to fracture varied amongst the five groups of files tested as follows: it decreased in some sizes of stainless-steel instruments, decreased in all sizes of titanium files assessed by the torsional moment, and either increased or decreased in some sizes of nickel-titanium files. All files tested, however, satisfied relevant standards for angular deflection after being subjected to sterilization with an autoclave or dry heat.

Absorbency properties of different brands of standardized endodontic paper points.

A comparative study of the absorbency properties of different endodontic paper points has been conducted. Twenty standardized absorbent paper points, size 30, from 13 bands (Dentaline, Zipperer, Kerr, Diadent, Roeko novo, Roeko color, Maillefer, P.D., Schein, Spectrapoint, Proclinic, Euronda, and Alpro) of 12 manufacturers were tested. Each dry paper point was weighted using an electronic laboratory balance. A length of 16 mm from the tip was then lowered in distilled water for 5 s, the paper point was weighted again, and the difference between both measurements was taken as the value of the fluid absorbed. Diadent, Kerr, and Dentalite showed significantly higher absorbencies (p < 0.05) than standardized paper points of the remaining brands. The study demonstrates a wide variation in the absorbency properties of this dental accessory.

A comparison of molar root canal preparations using six instruments and instrumentation techniques.

Six different instruments (Flexofile, Canal Master U, Heliapical, Flexogate, Ultraflex, and Lightspeed) were evaluated in 240 mesial canals of extracted mandibular molars (40 canals per instrument type). After instrumentation, the roots were cross-sectioned 2, 5, and 9 mm from the apex. The cross sections were evaluated to determine the quality of canal preparation (round, oval, irregular). The best results were obtained with nickel-titanium, a short cutting blade and a rotary rather than a filing motion. The Canal Master U, Flexogate, and Lightspeed instruments had significantly more round canals than the Flexofile, Heliapical and Ultraflex instruments at all levels. The Lightspeed had the largest number of round canals at all levels. Instrumentation time was also recorded. The Canal Master U and Flexogate were significantly slower than the Flexofile, heliapical, Ultraflex, and Lightspeed instruments. There were no statistically significant differences within the faster group.

Apical sealing using two thermoplasticized gutta-percha techniques compared with lateral condensation.

This study was conducted to compare the apical sealing capacity of three filling techniques, a multiphase gutta-percha obturation technique, JS Quickfill, and lateral gutta-percha condensation. A four-stage stepback preparation was executed with circumferential filing in a total of 70 recently extracted permanent maxillary incisors and canines. Three experimental groups (20 teeth in each group) and two control groups (5 teeth in each group) were formed at random. Each experimental group was obturated with a different technique. The positive control group was not obturated. In the negative control group, the whole root was covered with two full nail varnish layers. Teeth were immersed in India ink for 48 h, demineralized, cleared with methyl salicylate, and examined with a stereomicroscope. None of the specimens obturated with the multiphase gutta-percha obturation system showed any penetration of India ink beyond the end of the preparation. In the groups of teeth obturated by JS Quickfill or lateral gutta-percha condensation, leakage was detected in one specimen from each group. No statistically significant differences were seen among groups. We conclude that the newer thermoplasticized filling techniques can be used successfully to obturate root canals in large, straight roots.

Cutting efficiency of K-files manufactured with different metallic alloys.

The aim of this study was to compare, in vitro, the machining efficiency of different triangular cross-section K-files made of nickel titanium (Nitiflex, Naviflex), titanium (Microtitane), and stainless steel (Flexofile, Flex-R). Ten instruments of each K-file from size 25 to 40 were tested. The cutting efficiency was assessed in a linear motion using an indentation caliper to measure the depth of grooves. The load applied (in grams) was equal to the ISO file size. Each file was allowed to do 100 back-and-forward movements. Files made of stainless steel were the most effective, in particular Flexofile. There were statistically significant differences between Flexofile and Flex-R in all sizes. In the group of nickel titanium instruments, Nitiflex was significantly more efficient than Naviflex in all sizes. The machining ability of titanium files was higher than that of Naviflex but lower than that of Nitiflex and stainless steel files.