Natural killer T cells in allergic asthma: implications for the development of novel immunotherapeutical strategies.

Allergic asthma has emerged as a prevalent allergic disease worldwide, affecting most prominently both young individuals and lower-income populations in developing and developed countries. To devise effective and curative immunotherapy, it is crucial to comprehend the intricate nature of this condition, characterized by an immune response imbalance that favors a proinflammatory profile orchestrated by diverse subsets of immune cells. Although the involvement of Natural Killer T (NKT) cells in asthma pathology is frequently implied, their specific contributions to disease onset and progression remain incompletely understood. Given their remarkable ability to modulate the immune response through the rapid secretion of various cytokines, NKT cells represent a promising target for the development of effective immunotherapy against allergic asthma. This review provides a comprehensive summary of the current understanding of NKT cells in the context of allergic asthma, along with novel therapeutic approaches that leverage the functional response of these cells.

Multiple introductions, polyploidy and mixed reproductive strategies are linked to genetic diversity and structure in the most widespread invasive plant across Southern Ocean archipelagos.

Biological invasions in remote areas that experience low human activity provide unique opportunities to elucidate processes responsible for invasion success. Here we study the most widespread invasive plant species across the isolated islands of the Southern Ocean, the annual bluegrass, Poa annua. To analyse geographical variation in genome size, genetic diversity and reproductive strategies, we sampled all major sub-Antarctic archipelagos in this region and generated microsatellite data for 470 individual plants representing 31 populations. We also estimated genome sizes for a subset of individuals using flow cytometry. Occasional events of island colonization are expected to result in high genetic structure among islands, overall low genetic diversity and increased self-fertilization, but we show that this is not the case for P. annua. Microsatellite data indicated low population genetic structure and lack of isolation by distance among the sub-Antarctic archipelagos we sampled, but high population structure within each archipelago. We identified high levels of genetic diversity, low clonality and low selfing rates in sub-Antarctic P. annua populations (contrary to rates typical of continental populations). In turn, estimates of selfing declined in populations as genetic diversity increased. Additionally, we found that most P. annua individuals are probably tetraploid and that only slight variation exists in genome size across the Southern Ocean. Our findings suggest multiple independent introductions of P. annua into the sub-Antarctic, which promoted the establishment of genetically diverse populations. Despite multiple introductions, the adoption of convergent reproductive strategies (outcrossing) happened independently in each major archipelago. The combination of polyploidy and a mixed reproductive strategy probably benefited P. annua in the Southern Ocean by increasing genetic diversity and its ability to cope with the novel environmental conditions.

Characterization of microsatellite markers for the endangered Daphne rodriguezii (Thymelaeaceae) and related species.

PREMISE: The endangered shrub Daphne rodriguezii (Thymelaeaceae) is endemic to the Balearic island of Menorca, where fragmentation and severe population decline are ongoing threats to this taxon. We developed a set of microsatellite markers to analyze the fine-scale genetics of its few extant populations. METHODS AND RESULTS: Fifteen microsatellite markers were obtained through Illumina high-throughput sequencing and tested in two populations. Twelve of these loci showed no evidence of null alleles and were highly polymorphic, with a mean number of 8.3 alleles per locus. Levels of observed and expected heterozygosity ranged from 0.100 to 0.952 and from 0.095 to 0.854, respectively. Seven to nine of these loci were successfully amplified in five other Daphne species. CONCLUSIONS: This set of markers provides a useful tool for investigating the factors driving fine-scale population structure in this threatened species, and it represents a novel genetic resource for other European Daphne species.

Testing the hypothesis of loss of defenses on islands across a wide latitudinal gradient of Periploca laevigata populations.

PREMISE OF THE STUDY: We tested a hypothesis that predicts loss of chemical defenses on island plant populations (LCDIH) as an evolutionary response to limited herbivore pressures. METHODS: Using a common garden approach, we grew 16 populations (N = 286 seedlings) of Periploca laevigata, a Mediterranean shrub for which previous studies suggested that animal browsing elicits defensive responses mediated by tannins. Our experimental setting represented a wide latitudinal gradient (37-15°N) encompassing three island systems, virtually free of large herbivores, and three mainland areas. Putative chemical defenses were estimated from tannin-protein precipitation assays, and inducible responses in growth and chemical traits were assessed between seasons and by subjecting plants to a pruning treatment. KEY RESULTS: We failed to find support for the LCDIH, since island populations (Canary Islands, Cape Verde) had increasingly higher constitutive levels of tannins at lower latitudes. Seasonality, but not experimental pruning, induced variation in levels of tannins in a consistent pattern across populations. Thus, net differences in leaf tannin concentration remained similar among geographical areas regardless of the factor considered, with latitude being the best explanatory factor for this trait over seasonal growth patterns. CONCLUSIONS: Geographical variation in total tannin pools appears to be mediated by factors other than herbivore pressure in P. laevigata. We hypothesize that abiotic correlates of latitude not considered in our study have promoted high constitutive levels of leaf tannins across Macaronesian populations, which ultimately may explain the pattern of seasonal variation and latitudinal increase from Mediterranean to subtropical Cape Verde populations.

How repeatable is microevolution on islands? Patterns of dispersal and colonization-related plant traits in a phylogeographical context.

BACKGROUND AND AIMS: Archipelagos provide a valuable framework for investigating phenotypic evolution under different levels of geographical isolation. Here, we analysed two co-distributed, widespread plant lineages to examine if incipient island differentiation follows parallel patterns of variation in traits related to dispersal and colonization. METHODS: Twenty-one populations of two anemochorous Canarian endemics, Kleinia neriifolia and Periploca laevigata, were sampled to represent mainland congeners and two contrasting exposures across all the main islands. Leaf size, seed size and dispersability (estimated as diaspore terminal velocity) were characterized in each population. For comparison, dispersability was also measured in four additional anemochorous island species. Plastid DNA data were used to infer genetic structure and to reconstruct the phylogeographical pattern of our focal species. KEY RESULTS: In both lineages, mainland-island phenotypic divergence probably started within a similar time frame (i.e. Plio-Pleistocene). Island colonization implied parallel increases in leaf size and dispersability, but seed size showed opposite patterns of variation between Kleinia and Periploca species pairs. Furthermore, dispersability in our focal species was low when compared with other island plants, mostly due to large diaspore sizes. At the archipelago scale, island exposure explained a significant variation in leaf size across islands, but not in dispersability or seed size. Combined analyses of genetic and phenotypic data revealed two consistent patterns: (1) extensive within-island but very limited among-island dispersal, and (2) recurrent phenotypic differentiation between older (central) and younger (peripheral) island populations. CONCLUSIONS: Leaf size follows a more predictable pattern than dispersability, which is affected by stochastic shifts in seed size. Increased dispersability is associated with high population connectivity at the island scale, but does not preclude allopatric divergence among islands. In sum, phenotypic convergent patterns between species suggest a major role of selection, but deviating traits also indicate the potential contribution of random processes, particularly on peripheral islands.

Microleakage of the prosthetic abutment/implant interface with internal and external connection: in vitro study.

OBJECTIVE: This study determined the degree of marginal microleakage of the abutment-implant interface on platforms with Morse taper connection and external connection. MATERIALS AND METHODS: For this in vitro study, 42 implants, 21 with external connection and 21 with Morse taper connection, were used, immersed in acrylic resin cylinders. Each implant was joined by a prosthetic abutment screw tightened at different degrees, forming the six study groups: (1) External connection, manual tightening (2) External connection, 20 Newton (N) tightening (3) External connection, 30 N tightening (4) Morse taper connection, manual tightening (5) Morse taper connection, 20 N tightening (6) orse taper connection, 30 N tightening. All samples were subjected to load cycling and thermocycling. Then, they were submerged in a solution of 0.2% methylene blue for 24 h. Finally, the microleakage was measured via 20× optical microscopy in each study group, average was obtained, and Mann-Whitney test was applied. RESULTS: Statistically significant differences (P < 0.001) were found between the levels of microleakage presented in the Morse taper connection implants (1.48) and external connection implants (2.8) in all three types of tightening. Microleakage levels decreases when increasing torque is applied to the screws. CONCLUSION: Morse taper connection implants showed lower levels of microleakage than external connection implants; also, it was observed that microleakage decreases in the way torque increases.

The relevance of gene flow in metapopulation dynamics of an oceanic island endemic, Olea europaea subsp. guanchica.

Theoretical and empirical studies suggest that geographical isolation and extinction-recolonization dynamics are two factors causing strong genetic structure in metapopulations, but their consequences in species with high dispersal abilities have not been tested at large scales. Here, we investigated the effect of population age structure and isolation by distance in the patterns of genetic diversity in a wind-pollinated, zoochorous tree (Olea europaea subsp. guanchica) sporadically affected by volcanic events across the Canarian archipelago. Genetic variation was assessed at six nuclear microsatellites (nDNA) and six chloroplast fragments (cpDNA) in nine subpopulations sampled on four oceanic islands. Subpopulations occurring on more recent substrates were more differentiated than those on older substrates, but within-subpopulation genetic diversity was not significantly different between age groups for any type of marker. Isolation-by-distance differentiation was observed for nDNA but not for cpDNA, in agreement with other metapopulation studies. Contrary to the general trend for island systems, between-island differentiation was extremely low, and lower than differentiation between subpopulations on the same island. The pollen-to-seed ratio was close to one, two orders of magnitude lower than the average estimated for other wind-pollinated, animal-dispersed plants. Our results showed that population turnover and geographical isolation increased genetic differentiation relative to an island model at equilibrium, but overall genetic structure was unexpectedly weak for a species distributed among islands. This empirical study shows that extensive gene flow, particularly mediated by seeds, can ameliorate population subdivision resulting from extinction-recolonization dynamics and isolation by distance.

Recidiva del grado de clareamiento dental por té: in vitro / Relapse of dental bleaching after the consumption of tea: in vitro study

INTRODUCCION: El referente estético en nuestra sociedad viene determinado por varios factores, el que más insatisfacción produce es un color anómalo del diente, por eso que al mejorar su color dental, los pacientes esperan buenos resultados y duraderos. OBJETIVO: Determinar la recidiva de color experimentado por piezas dentarias clareadas y posteriormente sumergidas en solución de té. METODOLOGIA: Utilizamos 42 incisivos centrales sanos de bovinos de 3 y 4 años, preparados en probetas cilíndricas acrílicas, mantenidos en saliva artificial a 37ºC, a 100% de humedad, divididas en: grupo experimental (GC), tratado con peróxido de carbamida al 35% gel por 30 minutos y Grupo Control (GNC) no tratado. A ambos medimos color inicial con espectrofómetro Vita Easyshade® y sumergieron en solución de Té por 10 minutos. Medimos el nuevo color, realizando este procedimiento 50 veces. RESULTADOS: Analizados con, Pruebas T y Análisis de Regresión Lineal, tanto el GC como el GNC presentan el primer cambio de color con la primera inmersión en té. El segundo cambio para el GE (p < 0,029) es en la segunda inmersión y para el GC entre la tercera y cuarta. El cambio de color máximo fue alcanzado por el GNC entre las 20 a 30 inmersiones, sin embargo, el GC lo hace entre la 10 y 20 inmersión. CONCLUSIONES: Las piezas clareadas presentan mayor regresión del color que las piezas no tratadas. Además un color inicial claro determina cambios de más intensidad en menor tiempo y sin un patrón definido de progresión.

INTRODUCTION: Esthetic model in our society comes determined by several factors, one of the more important dissatisfaction is an anomalous color of the tooth for that reason patients are wating for good and long lasting results when improving the color of their teeth. OBJETIVE: To determine the color regression experienced by bleached teeth that were later plunged in a solution of tea. METHODOLOGY: 42 central permanent healthy incisor teeth from 3-4 year old bovine, supported in cylindrical acrylic and maintain in artificial saliva at 37ºC for 100% of humidity, were divided in: experimental group (CG), treated with Carbamide Peroxide 35% gel for 30 minutes and Control Group (NCG) not treated. In both, the initial color was measured with Vita Easyshade® Instruments and then plunged into Tea solution for 10 minutes. The new color was measured, and the procedure was repeated 50 times. RESULTS: Analyzed with, T tests and Analysis of Lineal Regression, both the GG and the NCG present the first change of color with the first dip in Tea. The second change for the CG (p < 0.029) is in the second dip and for the CG between the third and fourth dip. The change of maximum color was reached by the NCG between 20 to 30 dips, nevertheless, the CG dip does it between the 10 to 20 immersions. CONCLUSIONS: Bleached teeth present the highest return regression of the color that the not treated. In addition an initial clear color determines changes of more intensity in less time and without a definite form of progression.

Phenotypic plasticity and integration across the canopy of Olea europaea subsp. guanchica (Oleaceae) in populations with different wind exposures.

Woody plants, as sessile and long-lived organisms, are expected to have effective mechanisms for dealing with recurrent environmental stresses. In the present study, we hypothesized that phenotypic plasticity (the ability to express alternative phenotypes) and integration (covariation among functionally related traits) are elicited in plants under stressful wind speed conditions. We investigated the within-crown variation of nine vegetative traits of a tree species (Olea europaea subsp. guanchica) in six populations that represented a gradient of wind speed exposures. Wind-exposed twigs in outer-canopy layers had smaller leaves; thinner, lighter, and shorter internodes; and a larger internode cross-sectional area to leaf area ratio. Comparison between field and greenhouse trials revealed that field differences among populations were mediated by phenotypic plasticity. Outer-canopy twigs expressed plastic responses in populations exposed to high wind speeds, whereas inner-canopy twigs displayed high phenotypic convergence among populations. In addition, phenotypic integration increased with wind exposure (outer canopy > inner canopy > greenhouse) and was consequently affected by canopy openness. We conclude that exposure to wind above a certain speed threshold in this woody species elicits a plastic response that is associated with increased integration among traits and involves mechanical and hydraulic rearrangements in more exposed parts of the trees.

Field patterns of leaf plasticity in adults of the long-lived evergreen Quercus coccifera.

BACKGROUND AND AIMS: Quercus coccifera, as a long-lived sprouter, responds plastically to environmental variation. In this study, the role of foliar plasticity as a mechanism of habitat selection and modification within the canopy and across contrasted habitats was characterized. An examination was made of the differential contribution of inner and outer canopy layers to the crown plasticity expressed in the field by adult individuals and its dependence on environmental and genetic factors. METHODS: Within-crown variation in eight foliar traits was examined in nine populations dominated by Q. coccifera. The difference between mean trait values at the inner and outer canopy layers was used as a proxy for crown plasticity to light. Correlations between geographic distances, environmental differences (climatic and edaphic) and phenotypic divergence (means and plasticities) were assessed by partial Mantel tests. A subset of field measurements was compared with data from a previous common garden experiment. KEY RESULTS: Phenotypic adjustment of sun leaves contributed significantly to the field variation in crown plasticity. Plasticity in leaf angle, lobation, xanthophyll cycle pigments and beta-carotene content was expressed in sun and shade leaves concurrently and in opposite directions. Phenotypic plasticity was more strongly correlated with environmental variation than mean trait values. Populations of taller plants with larger, thinner (higher specific leaf area) and less spiny leaves exhibited greater plasticity. In these populations, the midday light environment was more uniform at the inner than at the outer canopy layers. Field and common garden data ranked populations in the same order of plasticity. CONCLUSIONS: The expression of leaf plasticity resulted in a phenotypic differentiation that suggests a mechanism of habitat selection through division of labour across canopy layers. Signs of plasticity-mediated habitat modification were found only in the most plastic populations. Intracanopy plasticity was sensitive to environmental variation but also exhibited a strong genetic component.

[Evaluation of the bone mass in the different types of menopause ]. / Evaluación de la masa ósea en los diferentes tipos de menopausia.

OBJECTIVE: To evaluate the bone mass condition in the different types of menopause and know if there is difference between the groups. DESIGN: Case reports. MATERIAL AND METHODS: From September through November 2001 at the Specialties Hospital No. 1, we studied 184 patients with menopause. They were divided in 5 groups: 74 regular menopause, 31 surgical menopause and oophorectomy unilateral, 43 surgical menopause and bilateral oophorectomy, 32 premature menopause, and 4 post-radiotherapy menopause, analyzing the bone mass with a densitometry. The statistical analysis was by descriptive statistics and t student to find the difference between the groups. RESULTS: We observed 45% with osteopenia y 8% with osteoporosis in regular menopause. In surgical menopause and oophorectomy unilateral group, we found 26% with osteopenia and 6% with osteoporosis. There were 42% with ostepenia and 14% with osteopososis in surgical menopause and bilateral oophorectomy group. In premature menopause, we found 47% with osteopenia and 12% with osteoporosis. In post-radiotherapy menopause, we found 75% with osteopenia and 25% with osteoporosis. All of them with predominance in femur. We did not observe any significant difference between the surgical and the premature menopause groups. CONCLUSIONS: In a half of patients with menopause we found bone mass decrease with predominance in femur, like osteopenia. There was no significant difference between the surgical and the premature menopause groups.

La osteoporosis primaria: un problema de salud / Primary osteoporosis: a health problem

La osteoporosis es una enfermedad a la cual los médicos comenzaron a darle magnitud de problema de salud en los últimos años. Hoy se considera la causa de casi la totalidad de las fracturas de cadera y de vértebras en personas mayores de 45 años de edad. Desde el punto de vista de los costos, agrava el presupuesto económico de la salud de la mayoría de los países en una suma de orden de los millones de pesos. En el presente artículo se hace una revisión de las teorías más recientes que tratan de explicar la patogenia de los dos tipos de osteoporosis primaria: la senil y la posmenopáusica, así como el diagnóstico y los modelos terapéuticos recomendados en la actualidad

Interconsultas de pediatría a psiquiatría infantil / Pediatric referral to child psychiatry

Este trabalho informa sobre la demanda por interconsulta al Servicio de Psiquiatria Infantil del Hospital Luis Calvo Mackenna. Este estudio forma parte de una evaluación más amplia de salud mental infantil en el SSMO, con el objeto de detectar necesidades de capacitación. Se muestra que los problemas psiquiátricos infantiles constituyen una demanda importante y difícil de atender en el nivel secundario. Los diagnósticos principales son los trastornos emocionales, síndrome hiperquinético/déficit atencional y trastornos de la conducta. La demanda satisfecha es cercana e un 40%, y la concordancia diagnóstica entre el médico de atención primaria y el especialista es alta (73,4%). Se efectúan algunas consideraciones acerca de las líneas de trabajo a futuro: perfeccionamiento y ampliación de normas, organización del servicio especializado y programa de capacitación primario