Evaluación del porcentaje de material núcleo en conductos radiculares obturados con puntas de gutapercha y de Real Seal de distintas conicidades

Objetivo. El objetivo del presente estudio fue evaluar el porcentaje de aterial núcleo en conductos radiculares de dientes monorradiculares obturados mediante compactación lateral y puntas de gutapercha o de Real Seal de conicidades 2% y 4% junto con un sellador. Material y métodos. Se emplearon 40 conductos de dientes maxilares anteriores. Se prepararon los conductos mediante rotación horaria continua hasta un calibre 30/.04. Se obturaron mediante compactación lateral en frío. Se formaron al azar cuatro grupos de diez especimenes 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 6 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 hallamos diferencias significativas en cuanto al porcentaje de material núcleo respecto al total del área de la sección de conductos radiculares obturados mediante puntas de gutapercha o Real Seal de conicidades 2% y 4%

Fracturas proximales de fémur. Osteosíntesis con tornillo-placa deslizante versus clavo gamma

Presentamos un estudio retrospectivo de noventa fracturas del fémur proximal tratados con clavo GAMMA o tornillo-placa dinámico de cadera (DHS). No encontramos diferencias en la duración de la intervención, pérdida hemática, ni estancia hospitalaria. Sin embargo, la serie con clavo GAMMA inició el apoyo más temprano, aunque en la revisión al final del seguimiento no había diferencias significativas en cuanto a la función de la cadera. El fracaso de la síntesis ocurrió en cuatro casos con el DHS, pero las complicaciones intraoperatorias fueron más frecuentes con el clavo GAMMA, principalmente elevada incidencia de fracturas de la diáfisis femoral, asociado en parte al diseño del implante. Recomendamos el empleo del clavo GAMMA sólo para las fracturas inestables del fémur proximal.We report a prospective study of ninety fractures of proximal femur treated by either the GAMMA nail or the dynamic hip screw (DHS). We found no difference in operating time, blood loss or stay in the hospital. However, the GAMMA nail group had a earlier full weight-bearing, but there was no significant difference in hip function at final review. There was failure of proximal fixation in four cases with the DHS. More intra-operative complications were recorded in the GAMMA nail group, mainly a high incidence of femoral shaft fracture which we relate in part to the design of the implant. We only recommend the use of the GAMMA nail for unstable intertrochanteric fractures of the proximal femur

Effect of acylation on the interaction of the N-Terminal segment of pulmonary surfactant protein SP-C with phospholipid membranes.

AbstractSP-C, the smallest pulmonary surfactant protein, is required for the formation and stability of surface-active films at the air–liquid interface in the lung. The protein consists of a hydrophobic transmembrane α-helix and a cationic N-terminal segment containing palmitoylated cysteines. Recent evidence suggests that the N-terminal segment is of critical importance for SP-C function. In the present work, the role of palmitoylation in modulating the lipid–protein interactions of the N-terminal segment of SP-C has been studied by analyzing the effect of palmitoylated and non-palmitoylated synthetic peptides designed to mimic the N-terminal segment on the dynamic properties of phospholipid bilayers, recorded by spin-label electron spin resonance (ESR) spectroscopy. Both palmitoylated and non-palmitoylated peptides decrease the mobility of phosphatidylcholine (5-PCSL) and phosphatidylglycerol (5-PGSL) spin probes in dipalmitoylphosphatidylcholine (DPPC) or dipalmitoylphosphatidylglycerol (DPPG) bilayers. In zwitterionic DPPC membranes, both peptides have a greater effect at temperatures below than above the main gel-to-liquid-crystalline phase transition, the palmitoylated peptide inducing greater immobilisation of the lipid than does the non-palmitoylated form. In anionic DPPG membranes, both palmitoylated and non-palmitoylated peptides have similar immobilizing effects, probably dominated by electrostatic interactions. Both palmitoylated and non-palmitoylated peptides have effects comparable to whole native SP-C, as regards improving the gel phase solubility of phospholipid spin probes and increasing the polarity of the bilayer surface monitored by pK shifts of fatty acid spin probes. This indicates that a significant part of the perturbing properties of SP-C in phospholipid bilayers is mediated by interactions of the N-terminal segment. The effect of SP-C N-terminal peptides on the chain flexibility gradient of DPPC and DPPG bilayers is consistent with the existence of a peptide-promoted interdigitated phase at temperatures below the main gel-to-liquid-crystalline phase transition. The palmitoylated peptide, but not the non-palmitoylated version, is able to stably segregate interdigitated and non-interdigitated populations of phospholipids in DPPC bilayers. This feature suggests that the palmitoylated N-terminal segment stabilizes ordered domains such as those containing interdigitated lipids. We propose that palmitoylation may be important to promote and facilitate association of SP-C and SP-C-containing membranes with ordered lipid structures such as those potentially existing in highly compressed states of the interfacial surfactant film

Mapping the Human Plasma Proteome by SCX-LC-IMS-MS

The advent of on-line multidimensional liquid chromatography-mass spectrometry has significantly impacted proteomic analyses of complex biological fluids such as plasma. However, there is general agreement that additional advances to enhance the peak capacity of such platforms are required to enhance the accuracy and coverage of proteome maps of such fluids. Here, we describe the combination of strong-cation-exchange and reversed-phase liquid chromatographies with ion mobility and mass spectrometry as a means of characterizing the complex mixture of proteins associated with the human plasma proteome. The increase in separation capacity associated with inclusion of the ion mobility separation leads to generation of one of the most extensive proteome maps to date. The map is generated by analyzing plasma samples of five healthy humans; we report a preliminary identification of 9087 proteins from 37,842 unique peptide assignments. An analysis of expected false-positive rates leads to a high-confidence identification of 2928 proteins. The results are catalogued in a fashion that includes positions and intensities of assigned features observed in the datasets as well as pertinent identification information such as protein accession number, mass, and homology score/confidence indicators. Comparisons of the assigned features reported here with other datasets shows substantial agreement with respect to the first several hundred entries; there is far less agreement associated with detection of lower abundance components

Synthesis and photochromic behaviour of new methyl induced linear and angular thieno-2H-chromenes

New methyl induced linear and angular thieno-2H-chromenes 4, 5 and 6 were prepared by reaction of new methylated 6-hydroxybenzo[b]thiophenes 2 (a, b and c) and propargylic alcohols 3a and 3b, using acidic Alumina Brockmann I as catalyst and drying agent. Compounds 2 were prepared in good to excellent yields in a “one pot” three step reaction from the corresponding bromo compounds 1. The photochromic behaviour of compounds 4, 5 and 6b was evaluated with the aid of a classical set of spectrokinetic parameters, and compared to reference compounds that are benzoannellated in the 5,6 and 6,7 positions of the chromene (naphthopyrans) and also to thieno-2H-chromenes 7 and 8, previously prepared, which are analogues of 5a. The resistance to fatigue (photodegradation) under continuous irradiation was also evaluated.Fundação para a Ciência e Tecnologia. Escola Superior de Tecnologia e Gestão do Instituto Politécnico de Bragança

Production and characterisation of recombinant forms of human pulmonary surfactant protein C (SP-C): Structure and surface activity

Surfactant protein C (SP-C) is an essential component for the surface tension-lowering activity of the pulmonary surfactant system. It contains a valine-rich α helix that spans the lipid bilayer, and is one of the most hydrophobic proteins known so far. SP-C is also an essential component of various surfactant preparations of animal origin currently used to treat neonatal respiratory distress syndrome (NRDS) in preterm infants. The limited supply of this material and the risk of transmission of infectious agents and immunological reactions have prompted the development of synthetic SP-C-derived peptides or recombinant humanized SP-C for inclusion in new preparations for therapeutic use. We describe herein the recombinant production in bacterial cultures of SP-C variants containing phenylalanines instead of the palmitoylated cysteines of the native protein, as fusions to the hydrophilic nuclease A (SN) from Staphylococcus aureus. The resulting chimerae were partially purified by affinity chromatography and subsequently subjected to protease digestion. The SP-C forms were recovered from the digestion mixtures by organic extraction and further purified by size exclusion chromatography. The two recombinant SP-C variants so obtained retained more than 50% α-helical content and showed surface activity comparable to the native protein, as measured by surface spreading of lipid/protein suspensions and from compression π-A isotherms of lipid/protein films. Compared to the protein purified from porcine lungs, the recombinant SP-C forms improved movement of phospholipid molecules into the interface (during adsorption), or out from the interfacial film (during compression), suggesting new possibilities to develop improved therapeutic preparations

Checklist for the Multidisciplinary Approach to United Airway in Patients with Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) and asthma

Dear Editor, The united airways concept calls for a multidisciplinary approach to asthma and/or chronic rhinitis/rhinosinusitis (CRS), aimed at integral airway treatment1, 2 and better coordination among specialists.3 Failure to treat rhinitis/rhinosinusitis is associated with poor asthma control, especially of severe asthma.4, 5 Biological treatments targeting type 2 (T2) inflammatory mediators in severe respiratory diseases offer a new therapeutic option directed against the pathophysiological mechanism of these difficult-to-control united airways diseases (UAD)..