Intubación nasotraqueal con fibrobroncoscopio como única posibilidad en un paciente con anquilosis de la articulación temporomandibular / Nasotracheal intubation with fibrobronchoscopy as the only possibility in a patient with ankylosis of the temporomandibular joint

No disponible

Evaluación clínica de los ácidos grasos omega-3 en la gestación, la lactancia y el desarrollo infantil / Clinical evaluation of omega-3 fatty acids on pregnancy, breast feeding and infant development

El propósito del estudio fue la revisión sistemática de la literatura médica con el fin de evaluar e identificar la influencia que los ácidos grasos (AG) omega-3 (o-3) ejercen sobre la salud infantil y materna. Se planteó como objetivo dar respuesta a una serie de preguntas acerca de la relevancia de la ingesta de AG o-3 en la duración de la gestación, incidencia de preeclampsia, eclampsia o hipertensión gestacional e incidencia de recién nacidos con bajo peso para su edad gestacional. También se revisó la influencia de los AG o-3 (suplementos o leche materna) en el crecimiento de los recién nacidos pretérmino y a término así como en el desarrollo neurocognitivo y visual. Como conclusiones señalar que los suplementos de AG o-3 podrían disminuir el riesgo de partos pretérmino e incrementar la duración del embarazo y el peso al nacer justificado por una alteración en la regulación de los eicosanoides, que se encuentran involucrados en la fisiología del trabajo de parto y en el crecimiento fetal, y que actúan favoreciendo el flujo sanguíneo placentario. La ingesta de AG o-3 durante el embarazo y la lactancia favorece el desarrollo cerebral en la infancia. También hay evidencia que podría justificar la prevención de la preeclampsia tras la administración de AG o-3 (AU)

The aim of this study was to conduct a systematic review of the scientific-medical literature to identify and appraise the evidence on the influence of omega-3 fatty acids on maternal and infant health. Evidence was sought to answer a series of questions about the effect of omega-3 fatty acid intake (supplemented during pregnancy) on pregnancy duration and the incidence of preeclampsia, eclampsia, gestational hypertension, and small for gestational age infants. The influence of omega-3 fatty acid intake (supplements or breast milk) on developmental outcomes in preterm and term infants, such as growth, neurocognitive development and visual function, were also investigated. Conclusions: Supplementation with omega-3 fatty acids during pregnancy lowers the risk of premature birth and can increase pregnancy duration and birth weight by altering the balance of eicosanoids. These molecules are involved in labor and also promote fetal growth by improving placental blood flow. Intake of omega-3 fatty acids during pregnancy and breast feed-ing may facilitate the infant's brain development. There is also some evidence that supplementation with omega-3 fatty acids may help to prevent preeclampsia (AU)

Modelling permeation through porous polymeric films for modified atmosphere packaging.

The use of perforated packaging films is increasing with the application of modified atmosphere packaging for fresh produce. These films provide high to very high mass exchange rates. However, irrespective of the chemistry of the material, mass transport through such films cannot be described using conventional permeability equations (Henry's plus Fick's laws). Other expressions such as Knudsen's law, gas diffusivities or Poiseuille's hydrodynamic flow can be applicable. The application of these laws is discussed and their corresponding range of validity is provided. These laws were also applied to model experimental permeation rates of oxygen and water and were further used to describe the headspace evolution of two fruit products in modified atmosphere packaging. In the light of these results, the contribution of different factors to the headspace evolution is discussed.

Phylogeography of crossbills, bullfinches, grosbeaks, and rosefinches.

Mitochondrial cytochrome b (cyt b) from 24 Carduelini species including crossbills, bullfinches, grosbeaks, rosefinches, and other related, but not conclusively classified species, was sequenced. These sequences were also compared with all the available sequences from the genera Carduelis, Serinus, and Passer. Phylogenetic analyses consistently gave the same groups of finches and the calculated divergence times suggest that speciation of the studied species occurred between 14 and 3 million years ago (Miocene-Pliocene), appearing before the Passer, Carduelis, and Serinus genera. Pleistocene glaciations may have been important in sub-speciation. Crossbills are integrated within the genus Carduelis, and within redpolls; the common crossbill shows subspeciation with Loxia japonica in the Pleistocene epoch. Pinicola enucleator groups together with bullfinches and is probably the ancestor of the group. Hawfinch is only distantly related to the studied groups, and might either represent an isolated genus or be related to the New World genus Hesperiphona. The grosbeak genera Eophona and Mycerobas are clearly sister groups, and species belonging to the former might have given rise to Mycerobas species. The isolated (in classification) Uragus sibiricus and Haematospiza sipahi are included within the genus Carpodacus (rosefinches); Carpodacus nipalensis is outside the genus Carpodacus in the molecular analyses and might be an isolated species or related to the genus Montifringilla.

The Old World sparrows (genus Passer) phylogeography and their relative abundance of nuclear mtDNA pseudogenes.

The phylogenetic relationships of genus Passer (Old World sparrows) have been studied with species covering their complete world living range. Mitochondrial (mt) cyt b genes and pseudogenes have been analyzed, the latter being strikingly abundant in genus Passer compared with other studied songbirds. The significance of these Passer pseudogenes is presently unclear. The mechanisms by which mt cyt b genes become pseudogenes after nuclear translocation are discussed together with their mode of evolution, i.e., transition/transversion mitochondrial ratio is decreased in the nucleus, as is the constraint for variability at the three codon positions. However, the skewed base composition according to codon position (in 1st position the percentage is very similar for the four bases, in 2nd position there are fewer percentage of A and G and more percentage of T, and in 3rd codon position fewer percentage of G and T and is very rich in A and C) is maintained in the translocated nuclear pseudogenes. Different nuclear internal mechanisms and/or selective pressures must exist for explaining this nuclear/mitochondrial differential DNA base evolutive variability. Also, the phylogenetic usefulness of pseudogenes for defining relationships between closely related lineages is stressed. The analyses suggest that the primitive genus Passer species comes from Africa, the Cape sparrow being the oldest: P. hispaniolensis italiae is more likely conspecific to P. domesticus than to P. hispaniolensis. Also, Passer species are not included within weavers or Estrildinae or Emberizinae, as previously suggested. European and American Emberizinae sparrows are closely related to each other and seem to be the earliest species that radiated among the studied songbirds (all in the Miocene Epoch).

Both morphological and molecular characters support speciation of South American siskins by sexual selection.

South American siskin radiation was studied by both mitochondrial cytochrome b (mt cyt b) DNA sequencing and homologous phenotypic characters; the latter were coded separately according to sex. Mixed phenetic and molecular (total evidence) dendrograms were constructed and the corresponding analyses suggest that speciation started in the South American siskin group with a north to south separation (Carduelis notata/C. barbata) along the Andean spine. A second split may have taken place around the Peruvian Andean mountains, corresponding to the present distribution pattern of C. olivacea. The most recent speciation events seem to have occurred in three sister species pairs: (i) C. xanthogastra/C. atrata, (ii) C. magellanica/C. yarrellii, (iii) C. cucullata/C. crassirostris. Accumulation of consistent characters in both morphological and molecular data at the basal nodes of the dendrograms indicate that speciation events occurred within a short period of time. Our data also suggest that speciation probably occurred by sexual selection through female mating choice in this radiation. Additionally, studies of variable amino acid residues in the mt cyt b molecule show that the three variable amino acids found are placed in the mitochondrial transmembrane region, which is also part of the hypervariable region in mammals. Each of the three amino acid changes occur in each of the three postulated evolutionary groups.

Phylogeny and rapid northern and southern hemisphere speciation of goldfinches during the Miocene and Pliocene epochs.

Mitochondrial cytochrome b (cyt b) from 25 out of 31 extant goldfinches, siskins, greenfinches and redpolls (genus Carduelis) has been sequenced from living samples taken around the world, specimens have also been photographed. Phylogenetic analysis consistently gave the same groups of birds, and this grouping was generally related to geographical proximity. It has been supposed that Pleistocene glaciations played a crucial role in the origin of extant diversity and distribution of Northern Hemisphere vertebrates. Molecular comparison of most extant songbird species belonging to the genus Carduelis does not support this assertion. The fossil record of chicken and pheasant divergence time has been used to calibrate the molecular clock; cyt b DNA dendrograms suggest that speciation in Carduelinae birds occurred during the Miocene and Pliocene Epochs (9-2 million years ago) in both the Northern and Southern Hemispheres. Only about 4% average amount of nucleotide substitution per lineage is found between the most distant Carduelis species; this suggests a remarkably rapid radiation when compared with the radiation of other passerine songbird genera. In addition, a continuum of small songbird speciation may be found during the Miocene Epoch in parallel with speciation of other orders (i.e. Galliformes, chicken/pheasant). Pleistocene glaciations may have been important in subspeciation (i.e. Eastern European grey-headed goldfinches/Western European black-headed goldfinches) and also in ice-induced vicariance (isolation) (i.e. siskin in Western Europe vs. siskin in Far East Asia) around the world. European isolated Serinus citrinella (citril finch) is not a canary, but a true goldfinch. South American siskins have quickly radiated in the last 4 million years coinciding with the emergence of the Isthmus of Panama; probably, a North American siskin related to C. notata invaded a suitable and varied biotope (the South American island) for Carduelis birds. North American goldfinches may be renamed as siskins, because they have a distant genetic relationship with European goldfinches. Genus Acanthis could be dropped, and thus redpolls should be separated from twite and linnet, the latter (Europeans) probably being related to American goldfinches. Also, reproductive barriers are observed between closely related species and not between other more distant ones. Finally, a tentative classification for genus Carduelis species is suggested.

Console abutment loading in craniofacial osseointegration.

Retention of implant-supported facial prostheses presents challenges in design that may lead to use of freestanding abutments. This is particularly so in the midface and orbit. Individual implant success rates are lower in these regions, and bone remodeling capacity may be compromised by combined modality cancer therapy. The present study was undertaken to determine the variations in load delivery so as to compare the use of long cantilevers and offset abutments with freestanding axially loaded abutments. The study revealed not only that the loads delivered are not trivial, but also that the highest loads generated are frequently delivered at the cervix of the implant. The long cantilevers produced the highest laterally acting cervical loads, whereas the 30-degree and 60-degree Console abutments delivered the highest laterally acting cervical loads of all the Console abutments. The potential of long cantilevers and offset abutments to deliver significant loads should be considered when designing retention for a facial prosthesis.

Craniofacial osseointegrated implant-induced strain distribution: a numerical study.

Strain distributions that occur in the hard tissue in the region surrounding craniofacial osseointegrated implants are compared. Three commercially available implant designs were evaluated under both axial loading and axial loading with a moment in three bone configurations typical of the craniofacial region. The evaluations that used the finite element method indicated that for axial loading, the implant designs produced similar strain levels in each bone configuration. When moments as well as vertical loads were applied, the strains were three to seven times higher and variations among the designs were greater. The variations found were related to the amount of bone present in each situation, as well as the neck diameter of the implant involved.

Mechanical evaluation of craniofacial osseointegration retention systems.

This study evaluates mechanical behavior of retention systems that have been used in craniofacial osseointegration. A loading/measuring apparatus was custom designed and constructed. Test bases that represented a typical auricular situation were constructed. These bases allowed for three points of retention. Jigs that could be reproducibly positioned carried the reciprocal portion of the retentive components. The test apparatus provided vertical and horizontal loads in five locations. The system was used to test two ball-and-socket attachments (Dalla Bona; Nobelpharma), cast and preformed bar and clips (Nobelpharma), and three magnet systems (Dynamag; Neomag; Technovent). The loading/measuring apparatus was also used to evaluate the performance of two facial prosthetic adhesives. Retention systems employed in craniofacial osseointegration offer more predictable retention than the facial prosthetic adhesives. The mechanical retention systems are best suited to situations where tensile and shear forces will operate. Magnet systems are best used where only tensile forces are anticipated or where horizontal forces on the implants are to be avoided.