La suplementación estratégica de bucerros manejados en pasturas con predominio de Hymenachne amplexicaulis estimula las conductas de ingestión y mejora la ganancia de peso / Strategic supplementation of buffalo calves managed in pastures with a predominance of Hymenachne amplexicaulis stimulates ingestion behavior and improves weight gain

Introducción: En Colombia, la producción bufalina viene creciendo de forma importante. Los búfalos se adaptan bien a zonas aluviales, que se caracterizan por la presencia de especies de gramíneas nativas, como Hymenachne amplexicaulis. Objetivo: Evaluar el efecto de diferentes tipos de suplementación sobre el desempeño productivo y comportamiento ingestivo de bucerros manejados en pasturas con predominio de Hymenachne amplexicaulis. Materiales y métodos: Treinta bucerros Murrah, con 67.5 (DE=2) kg de peso y 4 meses de edad, se asignaron, aleatoriamente, sí son tres tratamientos: SS: sin suplementación; SM: suplemento mineral y SM+C: suplemento mineral + balanceado (0.5% peso corporal). Los animales pastorearon en praderas con predominio de Hymenachne amplexicaulis, y en la noche recibieron el suplemento en corrales. Las variables estudiadas fueron la ganancia de peso y el tiempo destinado a realizar diferentes conductas de ingestión, además de las tasas de bocados y estaciones de alimentación. Resultados: El consumo diario de mezcla mineral fue de 33.8 g en los dos grupos suplementados, y el de balanceado de 149.3 g. La oferta de SM y de SM+C produjo un incremento extra en la ganancia de peso de 68 y de 227 g, respectivamente (p <0.001). Los animales suplementados presentaron mayor tiempo de pastoreo (p<0.001) y menor tiempo de rumia (p =0.001). La relación beneficio/costo, para los tratamientos SM y SM+C, fue de 4.2 y 4.3, respectivamente. Conclusión: Bajo las condiciones de estudio, las dos estrategias de suplementación evaluadas mejoraron el desempeño de los animales y presentaron viabilidad económica, en especial la oferta simultanea de mezcla mineral y de alimento balanceado.

Introduction: In Colombia, buffalo production has been growing significantly. Buffaloes adapt well to alluvial areas, which are characterized by the presence of native grass species, such as Hymenachne amplexicaulis. Objective: To evaluate the effect of different strategies of supplementation on the productive performance and ingestive behavior of calves managed in pastures with a predominance of Hymenachne amplexicaulis. Materials and methods: Thirty Murrah calves, weighing 67.5 (SD=2) kg and 4 months old, were randomly assigned to three treatments: SS: no supplementation; SM: mineral supplement and SM+C: mineral supplement + concentrate (0.5% body weight). The animals grazed in meadows with a predominance of Hymenachne amplexicaulis, and at night they received the supplement in pens. The variables studied were weight gain and time spent on different eating behaviors, in addition to biting rate and feeding stations. Results: The mineral mixture consumption was 33.8 g in the SM and SM+C groups, and the balanced consumption was 149.3 g. The supply of SM and SM+C produced an extra increase in weight gain of 68 and 227 g, respectively (p < 0.001). Supplemented animals grazed longer (p<0.001) and ruminated less time (p =0.001). The benefit/cost ratio for the SM and SM+C treatments was 4.2 and 4.3, respectively. Conclusion: Under the study conditions, the supplementation strategies evaluated improved the performance of the animals and presented economic viability, especially the simultaneous offer of mineral mix and balanced feed.

Primer premolar maxilar con tres conductos. A propósito de un caso / Maxillary first premolar with three canals. A case report

El éxito en el tratamiento de conductos radiculares va a depender entre otras cosas, del conocimiento de la morfología interna y externa de los dientes. Los primeros premolares maxilares presentan una amplia variación en la configuración de las raíces y los conductos radiculares, que debemos estudiar para el correcto diagnóstico y plan de tratamiento. Presentamos un caso clínico de un primer premolar superior con dos raíces y tres conductos

The success of root canal treatment depends on the knowledge of the internal and external tooth morphology among other things. Maxillary first premolars are said to exhibit large variation in root canal morphology we must know to make a proper diagnosis and treatment plan. This article reports a case of an upper left first premolar with two roots and three Canals

Tamizaje para sífilis en donantes de sangre y reactividad simultánea con otros marcadores en la Fundación Hematológica Colombia / Screening for syphilis in blood donors and simultaneous reactivity with other markers in the Fundación Hematológica Colombia / O rastreamento da sífilis em doadores de sangue e reativida- de simultânea com outros marcadores na Fundação Hemato - logia da Colombia

El presente artículo se propone caracterizar los donantes voluntarios de sangre que presentaron reactividad contra \r\nTreponema pallidum\r\n durante el periodo 2006-2011 y conocer la reactividad simultánea con otros marcadores en un \r\nbanco de sangre colombiano. Para ello, se realizó un estudio retrospectivo de corte transversal en el banco de sangre \r\nFundación Hematológica Colombia, Bogotá (Colombia). La población de estudio estuvo conformada por registros de \r\ndonantes voluntarios de sangre que presentaron reactividad en el tamizaje para \r\nTreponema pallidum\r\n y otros marca\r\n-\r\ndores entre 2006 y 2011.\r\nLa población de estudio estuvo conformada por 11.203 registros de donantes voluntarios de sangre, el promedio de \r\nedad fue de 43,27 ± 12,04 años, de los cuales el 56,2% (n=6.296) pertenecía al género masculino, el 11,1% (n=1.246) \r\nde los sujetos con tamizaje para sífilis presentaron coinfección para los marcadores de reactividad simultánea con \r\nsífilis; el de mayor presentación fue Anti-Core con un 67,7% (n=900), seguido de VIH con 10,3%. La prevalencia de \r\nsífilis del periodo de estudio fue de 1,9%.\r\nEn conclusión, se logró describir claramente las características generales de la población con tamizaje para sífilis, \r\nademás se encontraron datos estadísticamente significativos por género. Es importante conocer este tipo de compor\r\n-\r\ntamiento con el fin de fortalecer los procesos de selección de donantes de sangre y demostrar que la reactividad \r\nsimultánea no es un proceso aislado en un banco de sangre.

Objective: describe voluntary blood donors who showed \r\nreactivity to Treponema pallidum during 2006-2011 and \r\nto identify simultaneous reactivity with other markers \r\nin a Colombian blood bank. Materials and methods: a \r\nretrospective cross-sectional study was performed at the \r\nFundación Hematológica Colombia, Bogotá-Colombia. \r\nThe records of volunteer blood donors that showed reac\r\n-\r\ntivity for screening for Treponema pallidum and other \r\nmarkers of simultaneous screening during 2006-2011 \r\nwere included. Results: A total of 11.203 records of \r\nvoluntary blood donors were included; the mean age was \r\n43.27 ± 12.04 years, 56.2% males (n = 6.296), 11.1% \r\n(n = 1.246) of subjects with syphilis had co-infection \r\nand syphilis screening for markers simultaneous reacti\r\n-\r\nvity with syphilis. The greatest incidence was Anti Core \r\nwith 67.7% (n = 900), followed by HIV with 10.3%, \r\nthe prevalence of syphilis of the study period was 1.9%. \r\nConclusions: the general characteristics of the popula\r\n-\r\ntion with syphilis screening were clearly determined. \r\nThere is a statistically significant difference among the \r\ngenders. It is important to note this kind of behavior in \r\norder to reinforce the processes of blood donor selection, \r\nand to demonstrate that simultaneous reactivity is not an \r\nisolated process in the blood bank.

Objetivo: caracterizar os doadores voluntários de sangue \r\nque apresentaram reatividade contra \r\nTreponema pallidum\r\ndurante 2006-2011 e para conhecer a reatividade simul\r\n-\r\ntânea com outros marcadores em um banco de sangue \r\nna Colombia. Materiais e métodos: foi realizado um \r\nestudo transversal retrospectivo no banco de sangue da \r\nFundação de Hematologia Colombia, Bogotá, Colombia. \r\nA população do estudo consistiu de registros de doadores \r\nde sangue voluntários que apresentaram reatividade para \r\na triagem de Treponema pallidum e outros marcadores \r\ndurante 2006-2011. Resultados: a população do estudo \r\nconsistiu de 11.203 registros de doadores voluntários de \r\nsangue, a idade média foi de 43,27 ± 12,04 anos, sendo \r\nque 56,2% (n = 6.296) pertenciam ao sexo masculino, \r\n11,1% (n = 1.246) dos indivíduos tiveram co-infecção \r\npara os marcadores reatividade simultânea com a sífilis, \r\na maior incidência foi de Anti-Core com 67,7% (n = \r\n900), seguido por HIV com 10,3%, a prevalência de \r\nsífilis do período de estudo foi de 1,9%. Conclusão: foi \r\npossível descrever claramente as características gerais \r\nda população com sífilis também encontramos dados \r\nestatisticamente significativas por sexo. É importante \r\nconhecer esse tipo de comportamento, a fim de fortalecer \r\nos processos de seleção de doadores de sangue e também \r\nmostrar que a reatividade simultânea não é um processo \r\nisolado no banco de sangue.

Utilidad de HistoScanning™ previo a biopsia prostática para el diagnóstico de adenocarcinoma de próstata / Utility of HistoscanningTM prior to prostate biopsy for the diagnosis of prostate adenocarcinoma

Objetivos: HistoScanning™ (HS) es un método de diagnóstico ecográfico del cáncer de próstata. Analizamos la eficacia de la realización de HS previo a las biopsias para el diagnóstico de adenocarcinoma de próstata. Material y métodos: Entre agosto y octubre de 2012 hemos realizado estudio con HS previo a las biopsias en 32 pacientes. En todos los casos se realizaron biopsias transrectales por sextantes (2 tomas en cada sextante) de la zona periférica. En aquellos sextantes en los que hubo áreas sospechosas con HS las biopsias se dirigieron a dichas áreas. Se añadieron biopsias transperineales en aquellas áreas situadas en la zona media-anterior o apical prostática. La edad media fue de 63,7 años (rango: 40-82), con un PSA medio de 8,0 ng/ml (rango: 3,5-36,2) y un volumen prostático medio de 46,6 cc (rango: 18,2-103,2). En 8 casos se trataba de primera biopsia, en 14 de biopsias de repetición y 10 pacientes tenían diagnóstico previo de adenocarcinoma de próstata (8 en programa de vigilancia activa y 2 T1a en RTU de próstata previa). Resultados: En los 32 pacientes se biopsiaron una media de 7,5 zonas (rango: 6-9) con un total de 239 zonas estudiadas. Se identificaron una media de 3,2 zonas con áreas sospechosas (ZS) con HS (rango: 2-5), con un total de 103 ZS. Se encontró adenocarcinoma o PIN en 72 zonas de 25 pacientes (2 PIN, 11 score Gleason 6, 7 score Gleason 7, 3 score Gleason 8 y 2 score Gleason 9). Hubo 35 zonas falsos positivos en 20 pacientes (11 parénquima normal y 9 inflamación crónica). Se produjeron falsos negativos en 5 zonas en 5 pacientes (2 PIN, 2 score Gleason 6 y un score Gleason 7), aunque en los 5 casos se descubrió adenocarcinoma en otras zonas. El HS presentó una sensibilidad del 93,5% con una especificidad del 79,5%. El valor predictivo positivo fue del 67,35% con un valor predictivo negativo del 96,5%. Conclusiones: A pesar de tratarse de una serie seleccionada, con alta tasa de pacientes con adenocarcinoma, la exploración con HS ha presentado una gran sensibilidad y un elevado valor predictivo negativo. Estos datos, aunque deben ser confirmados en series menos seleccionadas, indican que la exploración previa con HS puede ayudar tanto al diagnóstico en las biopsias como en el seguimiento en programas de vigilancia activa (AU)

Objectives: HistoScanning™ (HS) is a method of ecographic diagnosis of prostate cancer. We analyze the effectiveness of the HS realization prior to the biopsys for the prostate adenocarcinoma diagnosis. Material and methods: From August to October 2012 we have carried out a study with HS prior to the biopsys in 32 patients. In all cases sextants transrectalbiopsys have been realized (two cores in each sextant) in the periphery zone. In those sextants in which there were suspicious areas with HS, the biopsys were addressed to those areas. Transperinealbiopsys were added to those zones placed in the half-front or apical prostatic zone. The medium age was 63.7 years (range 40-82) with a medium PSA of 8.0ng/ml (range 3.5-36.2) and a medium prostatic volume of 46.6 cc (range 18.2-103.2). In eight cases it was the first biopsy, in 14 cases they were repetition biopsys and 10 patients had a previous diagnosis of prostate adenocarcinoma (8 in a program of active surveillance and 2 T1a in RTU of previous prostate). Results: In the 32 patients a medium of 7,5 zones were biopsed (range 6-9) with a total of 239 zones studied. There were identified a medium of 3.2 zones with suspictious areas (ZS) with HS (range 2-5) with a total of 103 ZS. In 72 zones of 25 patients it was found adenocarcinoma or PIN (2 PIN, 11 score Gleason 6, 7 score Gleason 7, 3 score Gleason 8 and 2 score Gleason 9). There were 35 positive falses zones in 20 patients (11 normal parenquima and 9 cronic inflammation). Negative falses were produced in 5 zones in 5 patients (2 PIN, 2 score Gleason 6 and 1 score Gleason 7) although in all 5 cases adenocarcinoma was encountered (o discovered) in other zones. The HS presented a sensibility of a 93.5% with a specificity of 79.5%. The positive predictive value was of the 67.35% with a negative predictive value of 96.5%. Conclusions: In spite of being a selected serie, with a high rate of patients with adenocarcinoma, the exploration with HS has presented a great sensibility and a high negative predictive value. These data, although they must be confirmed in less selected series, state that the prior exploration with HS can help as in the diagnostic in the biopsies as in the follow-up of programs of active surveillance (AU)

Absorción de nutrientes en corderos alimentados con dietas con diferentes cantidades de fósforo / Nutrient absorption in lambs fed diets containing different amounts of phosphorus

Objective. Evaluate the effect of increasing P intake on nutrient digestibility, and compare the true and apparent absorption coefficients of P and Ca in lambs. Materials and methods. Twenty-four Santa Ines sheep, with an average weight of 33.6 ± 1.6 kg, were distributed into four treatments (0, 2, 4 and 6 g/day of supplementary P) with forage: concentrate ratio of 70:30. The study of apparent nutrient digestibility was conducted during the first week, using the total feces collection method. During the second week, after injection of 7.4 MBq of 32P and 7.7 MBq of 45Ca, apparent (AAC) and true (TAC) absorption coefficients of P and Ca were determined. The lambs were kept in metabolic cages. Results. The increase in P intake did not affect (p>0.05) dry matter, crude protein, NDF or ADF digestibility, but the TAC of P and Ca and mineral matter digestibility decreased. The AAC was not affected (p=0.10). A cubic relationship was observed between P intake and TAC (TAC=2.16–1.95X+0.55X2-0.04X3; R2=0.38) and linear relationship with the TAC of Ca (TAC=0.559–0.03X; R2=0.26). TAC and AAC values were different (p<0.001). Conclusions. The increase in P intake doesn’t impact organic matter digestibility, but does affect P and Ca absorption. Apparent digestibility is not a reliable parameter to determine the efficiency of P and Ca absorption.

Objetivo. Evaluar el efecto del incremento en la ingestión de P sobre la digestibilidad de los nutrientes, y comparar los coeficientes de digestibilidad real y aparente de Ca y P en ovinos. Materiales y métodos. Veinticuatro ovinos de la raza Santa Inés, con 33.6±1.6 kg de peso, fueron asignados a cuatro tratamientos (0, 2, 4 y 6 g/día de P suplementario) con relación forraje:concentrado de 70:30. El estudio de digestibilidad aparente de los nutrientes se realizó la primera semana usando el método de colecta total de heces. La segunda semana, luego de inyectar 7.4 MBq de 32P y 7.7 MBq de 45Ca, se realizó el estudio de absorción real (CAV) y aparente (AAC), en jaulas de estudio de metabolismo. Resultados. El incremento en la ingestión de P no afectó (p>0.05) la digestibilidad aparente de la materia seca, proteína bruta, FDN o FDA. El CAV de Ca y de P y la digestibilidad de la materia mineral presentaron una reducción. EL AAC no fue afectado (p=0.10). La ecuación CAV=2.16–1.95X+0.55X2-0.04X3 (R2 = 0.38) explicó la relación entre el CAV de P y el incremento en su ingestión, y la ecuación TAC=0.559 – 0.03X (R2=0.26), la relación entre el CAV de Ca y la ingestión de P. Los valores de AAC y CAV difirieron entre sí (p<0.001). Conclusiones. La ingestión de P no afectó la digestibilidad de la fracción orgánica del alimento, pero sí la absorción de P y Ca. El coeficiente de absorción aparente no fue un parámetro confiable para determinar la eficiencia de absorción de P y Ca.

Utility of Histoscanning™ prior to prostate biopsy for the diagnosis of prostate adenocarcinoma.

OBJECTIVES: HistoScanning™ (HS) is a method of ecographic diagnosis of prostate cancer. We analyze the effectiveness of the HS realization prior to the biopsies for the prostate adenocarcinoma diagnosis. MATERIAL AND METHODS: From August to October 2012 we have carried out a study with HS prior to the biopsies in 32 patients. In all cases sextants transrectal biopsies have been realized (two cores in each sextant) in the periphery zone. In those sextants in which there were suspicious areas with HS, the biopsies were addressed to those areas. Transperineal biopsies were added to those zones placed in the half-front or apical prostatic zone. The medium age was 63.7 years (range 40-82) with a medium PSA of 8.0 ng/ml (range 3.5-36.2) and a medium prostatic volume of 46.6cc (range 18.2-103.2). In eight cases it was the first biopsy, in 14 cases they were repetition biopsies and 10 patients had a previous diagnosis of prostate adenocarcinoma (8 in a program of active surveillance and 2 T1a in RTU of previous prostate). RESULTS: In the 32 patients a medium of 7,5 zones were biopsied (range 6-9) with a total of 239 zones studied. There were identified a medium of 3.2 zones with suspicious areas (ZS) with HS (range 2-5) with a total of 103 ZS. In 72 zones of 25 patients it was found adenocarcinoma or PIN (2 PIN, 11 score Gleason 6, 7 score Gleason 7, 3 score Gleason 8 and 2 score Gleason 9). There were 35 positive false zones in 20 patients (11 normal parenquima and 9 chronic inflammation). Negative falses were produced in 5 zones in 5 patients (2PIN, 2 score Gleason 6 and 1 score Gleason 7) although in all 5 cases adenocarcinoma was encountered (o discovered) in other zones. The HS presented a sensibility of a 93.5% with a specificity of 79.5%. The positive predictive value was of the 67.35% with a negative predictive value of 96.5%. CONCLUSIONS: In spite of being a selected serie, with a high rate of patients with adenocarcinoma, the exploration with HS has presented a great sensibility and a high negative predictive value. These data, although they must be confirmed in less selected series, state that the prior exploration with HS can help as in the diagnostic in the biopsies as in the follow-up of programs of active surveillance.

Quantitative and functional evaluation of innate immune responses in patients with common variable immunodeficiency.

OBJECTIVES: We evaluate the frequency and functional response of innate immune cells in peripheral blood (PB) from patients with common variable immunodeficiency (CVID) and healthy controls upon activation with agonists of the Toll-like receptors (TLR) TLR2, TLR4, and TLR9. In addition, several nonsynonymous single nucleotide polymorphisms (SNPs) within these TLR genes were examined. METHODS: Flow cytometry was used to perform immunophenotyping and evaluate the expression of cell surface markers. Levels of cytokines in the culture supernatants were evaluated using cytometric bead array technology. SNPs in the TLR genes were evaluated from genomic DNA using different sequencing techniques. RESULTS: Our results demonstrate that the frequency of CD1d-restricted TCR invariant natural killer T cells in PB was significantly reduced in the patients with CVID. A marked, though not significant, reduction in absolute numbers of plasmacytoid dendritic cells and natural killer cells was also observed in these patients. Interestingly, CD80 and CD86 expression on innate cells upon stimulation with TLR ligands was not altered in the patients although 3 of them exhibited low baseline levels of these surface molecules on monocytes compared to healthy controls. We also observed a significant increase in TNF-alpha levels in supernatants of PB mononuclear cells from CVID patients after stimulation with lipopolysaccharide. Finally, no association was found between the presence of nonsynonymous SNPs within the TLR genes and the clinical presentation of CVID. CONCLUSIONS: Taken together, our study demonstrates than innate immune responses are disturbed in some CVID patients and prompts the evaluation of innate immunity genes as candidates to explain the CVID clinical phenotype.

Amoxicillin-Loaded Sponges Made of Collagen and Poly[(methyl vinyl ether)-co-(maleic anhydride)] for Root Canal Treatment: Preparation, Characterization and In Vitro Cell Compatibility.

The difficulty of eliminating Enterococcus faecalis and other bacteria infecting dental root canals makes it desirable to develop formulations capable of sustained release of antibiotics within the canal. With this function in view, in this work we compared the mechanical, drug release and biocompatibility properties of amoxicillin-loaded collagen (CL) and CL complexed with poly[(methyl vinyl ether)-co-(maleic anhydride)] (PVMMA), with or without glutaraldehyde (GTA) or the natural product genipin (GN) as cross-linker. Collagen was not denatured by complexation with PVMMA. Only CL-PVMMA-GN sponges did not disintegrate during 7 days exposure to cell culture medium (un-cross-linked CL disintegrated within 24 h and un-cross-linked CL-PVMMA within 4 days), and CL-PVMMA-GN sponges also exhibited the most appropriate combination of mechanical properties (hardness, modulus of deformability and plasticity). CL-PVMMA-GN sponges absorbed aqueous medium faster than other cross-linked formulations, but their maximum uptake was less; and drug release from CL-PVMMA-GN sponges tended to be faster than from any other, except un-cross-linked CL-PVMMA, maximum release taking about 4 days. No formulation significantly altered the viability of L929 fibroblast-like mouse connective tissue cells, but cells growing on sponges showed signs of non-adherence. It is concluded that genipin-cross-linked CL-PVMMA sponges merit further investigation as antibiotics vehicles and aids to tissue regeneration in the dental root canal.

The corrosion of nickel-titanium rotary endodontic instruments in sodium hypochlorite.

AIM: To evaluate the corrosion resistance of nickel-titanium (NiTi) endodontic rotary instruments immersed in 5.25% sodium hypochlorite (NaOCl) solution. METHODOLOGY: The corrosion performance of NiTi instruments (S1 25 mm, ProTaper Dentsplay Maillefer, Ballaigues, Switzerland) was evaluated using commercial 5.25% NaOCl solution (pH = 12.3), and the same solution partially neutralized adding H2SO4 to reach pH = 10.1. Electrochemical measurements were carried out using a potentiostat equipped with a five-channel zero resistance ammeter (ZRA) for galvanic current measurements. The instruments were sectioned into three parts (cutting part, noncutting part and shank) and degreased with acetone and rinsing with demineralized water prior to being immersed in NaOCl solution for testing. Each set of the three parts constituted one 'virtual' instrument through the ZRA, giving access to the galvanic currents that circulate between the three parts. Nine instruments were employed to check the reproducibility of the electrochemical measurements. RESULTS: The corrosion potential (E(corr)) of the NiTi alloy reached the passive domain in approximately 20 s of immersion in the solution having a pH 10.1. After this initial period the potential remained steady, indicating that stable passivation was achieved. However, at pH 12.3 no stationary state was achieved even after 6000 s of immersion time. Thus, the alloy was not stable in this medium from a corrosion point of view. CONCLUSIONS: The corrosion resistance of NiTi alloy was enhanced by lowering the pH of NaOCl solution to 10.1, which allows the system to reach the stability domain of the passivating species TiO2 and NiO2.

Hamartoma mesenquimatoso hepático gigante en una niña de 2 años / Giant hepatic mesenchymal hamartoma in a 2-year-old girl

No disponible

La influencia de la permeabilidad manual en el porcentaje de separación de los instrumentos rotatorios de NiTi / The influence of a manual glide path on the separation rate of Niti rotary instruments

El propósito doble de este estudio fue evaluar el porcentaje de fracturas de los instrumentos rotatorios de Ni-ti al seguir una permeabilidad preparada manualmente con limas manuales de acero inoxidable antes de la instrumentación con limas rotatorias y comparar los resultados en este estudio con los obtenidos en dos análisis previos en que no se empleó la técnica de permeabilidad manual. Se dividieron un total de 208 conductos radiculares obtenidos de una muestra de molares humanos superiores e inferiores recientemente extraídos en tres grupos que correspondieron a K3, ProFile y ProTaper. Se emplearon los 2/3 coronales de cada diente. En los tres grupos la porción apical de las muestras se preparó con limas manuales K de acero inoxidable de calibres 10-20. Los topes apicales se prepararon con instrumentos rotatorios K3, ProFile y ProTaper. El análisis del modelo de regresión logística indicó que la rotura estaba significativamente asociada con el ángulo de curvatura del conducto (OR= 1.078; 95% CI= 1.032-1.12; p= 0,001) y con el número de usos clínicos (las limas empleadas más de ocho veces se rompieron más frecuentemente que las empleadas de 1 a 2 veces; OR= 22.686; CI 95%: 2,6-191.3; p= 0,004). El porcentaje de rotura obtenido en este estudio es significativamente menor que en nuestros estudios previos, en que el ángulo de curvatura era también mayor de 30° y la velocidad constante de rotación de 350 rpm, pero en que los conductos no se prepararon inicialmente con limas manuales (25/205= 12% frente a l6/6l = 26%, p= 0,007). Basándose en los resultados de este estudio, recomendamos el uso de limas manuales de acero inoxidable para preparar el tercio apical de los conductos curvados antes de emplear las limas rotatorias

The dual purpose of this study was, to evaluate the fracture rate of Ni-Ti rotary instruments when following a manual glide path and using stainless steel band files before carrying out instrumentation by means of rotary files and, to compare the results in this study with those obtained in two previous analyses, in which the glide path technique was not used. A total of 208 canals obtained from a pool of freshly extracted human mandibular and maxillary molars was divided into three groups corresponding to; K3, ProFile and ProTaper. The coronal 2/3 of each tooth were used. In all three groups the apical portion of the samples was prepared with size 10-20 stainless steel K-type hand files. The apical stops were prepared using K3, ProFile and ProTaper rotary instruments. Logistic regression model analysis indicated that breakage was significantly associated with the angle of curvature of the canal (OR = 1.078; 95% Cl= 1.032-1.12;p = 0.001), and with the number of clinical uses (files used more than eight times broke more frequently that those used 1 o 2 times; OR: 22.686; 95% Cl: 2.6-191.3; p= 0.004). The breakage rate obtained in the present study is significantly lower than in our previous studies, in which the angle of curvature was also greated than 30° and rotational speed a constant 350 rpm, but in which the canals were not first prepared with hand files (25/205 = 12% versus 16/61 = 26%, p = 0.007). Based on the results of this study, were recommend the use of stainless steel band files to prepare the apical 1/3 of curved canals before introducing rotary files

Apoptosis as a mechanism of natural resistance to HIV-1 infection in an exposed but uninfected population.

BACKGROUND: Apoptosis, also known as programmed cell death, has been reported not only as a pathogenic mechanism, but also as a mechanism of resistance and control of a variety of infections. Particularly during HIV-1 infection, apoptosis is the main mechanism by which infected and uninfected CD4+ lymphocytes are eliminated. However, apoptosis as a mechanism of natural resistance to HIV infection has this far not been explored. OBJECTIVE: To determine whether apoptosis could explain, at least in part, the natural resistance to HIV infection observed in some exposed but uninfected individuals (ESN). RESULTS: Our data shows that peripheral blood monocytes in the ESN group has a predisposition to undergo spontaneous apoptosis, as well as apoptosis induced by HIV infection in vitro, compared with monocyte population from the control group at low risk of HIV infection. CONCLUSIONS: These findings suggest that, in some ESN individuals, monocytes could play an important role in the control of HIV infection by undergoing apoptosis. However, since the variability among individuals is large, studies with larger cohorts focusing in monocyte apoptosis as pathogenic mechanisms are required.

Normal expression of IFN-gammaR in four patients with uncommon mycobacterial infection phenotypes

Several primary immunodeficiency diseases affecting the interleukin 12/interferon gamma (IFN-gamma) pathway have been identified, most of them characterized by recurrent and protracted infections produced by intracellular microorganisms, particularly by several species of mycobacteria. In the present study we analyzed the expression of IFN-gamma receptor (IFN-gammaR) and signal transducer and activator of transcription 1 (STAT-1) in 4 children with Mycobacterium tuberculosis infection of uncommon clinical presentation. These molecules were evaluated by flow cytometry and Western blotting in B cells transformed with Epstein-Barr virus and mutations were scanned by single-strand conformational polymorphisms and DNA sequencing. The expression of IFN-gammaR1 was normal in all 4 patients. The genetic analysis of IFN-gammaR1 and IFN-gammaR2 coding sequences did not reveal any mutation. The expression of the STAT-1 molecule was similar in patients and healthy controls; however, when the phosphorylation of this transcription factor in response to IFN-gamma activation was evaluated by Western blot, a significant lower signal was evident in one patient. These data indicate that there are no alterations in the expression or function of the IFN-gammaR chains in these patients. However, the low level of STAT-1 phosphorylation found in one of these patients might be explained by a defect in one of the molecules involved in the signal transduction pathway after IFN-gamma interacts with its receptor. In the other three patients the inability to eliminate the mycobacteria may be due to a defect in another effector mechanism of the mononuclear phagocytes.

Normal expression of IFN-gammaR in four patients with uncommon mycobacterial infection phenotypes.

Several primary immunodeficiency diseases affecting the interleukin 12/interferon gamma (IFN-gamma) pathway have been identified, most of them characterized by recurrent and protracted infections produced by intracellular microorganisms, particularly by several species of mycobacteria. In the present study we analyzed the expression of IFN-gamma receptor (IFN-gammaR) and signal transducer and activator of transcription 1 (STAT-1) in 4 children with Mycobacterium tuberculosis infection of uncommon clinical presentation. These molecules were evaluated by flow cytometry and Western blotting in B cells transformed with Epstein-Barr virus and mutations were scanned by single-strand conformational polymorphisms and DNA sequencing. The expression of IFN-gammaR1 was normal in all 4 patients. The genetic analysis of IFN-gammaR1 and IFN-gammaR2 coding sequences did not reveal any mutation. The expression of the STAT-1 molecule was similar in patients and healthy controls; however, when the phosphorylation of this transcription factor in response to IFN-gamma activation was evaluated by Western blot, a significant lower signal was evident in one patient. These data indicate that there are no alterations in the expression or function of the IFN-gammaR chains in these patients. However, the low level of STAT-1 phosphorylation found in one of these patients might be explained by a defect in one of the molecules involved in the signal transduction pathway after IFN-gamma interacts with its receptor. In the other three patients the inability to eliminate the mycobacteria may be due to a defect in another effector mechanism of the mononuclear phagocytes.

Analysis of the area and length of masticatory cycles in male and female subjects.

It is difficult to determine the existence of a normal or physiological masticatory cycle, because there exists great individual diversity. This study presents some data about two parameters of masticatory cycles according to the frontal plane, i.e. the area and length of right-sided and left-sided cycles in a group of 30 young people, 18 women and 12 men. For our study the Myotronics K6-1 kinesiograph was used. It registers the magnetic field and allows us to obtain graphic recordings of the jaw movement in the three space planes. Other authors have analysed these parameters, but none of those reviewed provides information about the distribution to each side or according to the gender of sampling subjects selected for the analysis. We have tried to describe the normal morphology of the masticatory cycles and, also, establish a reference so as to provide help in the diagnosis of the functional pathology of the masticatory system.

Estudio de la filtración en materiales de obturación a retro / Study of leakage in retrofilling materials

Introducción: La elección de un material biocompatble adecuado en la obturación a retro es uno de los objetivos para el éxito en una apicetomía. Objetivos: Valorar la filtración en los materiales más utilizados en las obturaciones a retro. Material y métodos: Estudiamos la filtración de MTA® (Maillefer), gutapercha (Dentsply Detrey), amalgama (Tytin©), IRM© (Dentsply Detrey) como materiales en obturaciones a retro, con azul de metileno y posterior diafanización para ser estudiados en lupa estereoscópica. Previamente se estandarizaron los niveles de filtración por medio de un programa de medición digital por ordenador (Micro Image© 3.0). El análisis estadístico de filtración se realizó por medio de la comparación global o Kruskal-wallis y la comparación dos a dos o de Bonferroni. Resultados: El cemento MTA® (Maillefer) junto con la amalgama Tytin® Kerr poseen los índices más bajos de filtración- en las obturaciones-. a. retro (AU)

Estudio comparativo de microfiltración con tres sistemas de foto olimerización / Comparative study of microfiltration with three fotopolymerizer systems

La aparición de nuevas energías ionizantes como el láser de argón, el gas xenón (luz plasma), luz halógena de intensidad progresiva junto con la mejora de las resinas compuestas nos permitirá acortar el tiempo de curado, la colocación de mayores espesores de material y una menor contracción de polimerización. El objetivo de este estudio es observar el grado de filtración in vitro de cavidades de clase 11 obturadas con composite y polimerizadas con luz halógena continua, luz halógena de intensidad progresiva y luz plasma: Se realizaron 60 cavidades de clase 11 estandarizadas y se dividieron aleatoriamente en tres grupos polimerizando cada grupo con una de las siguientes lámparas: Wavelight®, Astralis® 7 y Heliolux© GTE siguiendo las indicaciones de las casas comerciales. Se sometieron a un proceso de termociclado y posteriormente se sumergieron en azul de metileno durante 24h. Tras la observación con lupa estereoscópica encontramos una menor filtración con la Astralis 7 aunque las diferencias no son estadísticamente significativas (AU)