Immunofluorescence evaluation of Myf5 and MyoD in masseter muscle of unilateral posterior crossbite patients

A unilateral posterior crossbite is a malocclusion where the low activity of the affected masseter muscle is compensated by the contralateral muscle hypertrophy. It is still unknown if, in the same condition, myogenesis with new fibre formation takes place. Aim: the aim of the present study was to evaluate the expression of myogenesis markers, such as Myf5 and MyoD, in masseter muscles of unilateral posterior crossbite patients. Materials and methods: biopsies from fifteen surgical patients with unilateral posterior crossbites have been analysed by immunofluorescence reactions. The results show the expression of Myf5 and MyoD in the contralateral muscle but not in the ipsilateral one. Moreover, statistical analysis shows the higher number of satellite cells in the contralateral side if compared to the ipsilateral one. Conclusions: these results suggest that in contralateral muscle, hyperplastic events take place, as well as hypertrophy

Sella turcica and craniofacial morphology in patients with palatally displaced canines: a retrospective study

Background: The aim of the study was to evaluate the sella and craniofacial morphological features in growing patients with palatally displaced canines compared to controls. Materials and methods: Twenty-two subjects with palatally displaced canines were retrospectively selected and compared to 22 controls matched for age and gender. Lateral cephalograms were collected and sagittal and vertical cephalometric variables were measured, together with sella interclinoid distance, sella depth, and sella diameter. The independent samples T-test or Mann-Whitney U-test were used to compare all the variables between the two groups. A Pearson correlation was computed for the craniofacial and sella variables that differed significantly (p < 0.05) between the groups. Results: Patients with palatally displaced canines showed a smaller interclinoid distance and a greater SNA angle than control subjects. The interclinoid distance and the SNA angle were negatively correlated (–0.52, p = 0.017) in the experimental group. Conclusions: Growing patients with palatally displaced canines had smaller sella interclinoid distances and a greater SNA angle than control subjects

Effectiveness of Two Different Fluoride-Based Agents in the Treatment of Dentin Hypersensitivity: A Prospective Clinical Trial

Hyperesthesia is related to increased sensitivity of dental tissues to mechanical, chemical and thermal stimuli. The aim of this prospective clinical trial was to compare the effectiveness of a calcium-fluoride-forming agent (Tiefenfluorid®, Humanchemie GmbH, Alfeld, Germany) with that of a fluoride varnish (Enamelast™, Ultradent Inc., Cologne, Germany) in the treatment of dental hyperesthesia in adult patients. In total, 176 individuals (106 females and 70 males, aged 18–59 years old) diagnosed with dental hyperesthesia (DH) were enrolled. The main clinical symptoms were hyperesthesia from coldness and sweetness during chewing; the types of clinical lesions were also determined and recorded. The patients were selected randomly and divided into two groups: (i) the first group of 96 patients was treated with Tiefenfluorid® applied in three appointments at 7-day intervals; (ii) the second group of 80 patients was treated with Enamelast™, applied seven times at 7-day intervals. All the patients were recalled 7 days, 14 days, 1 month, 3 months, and 6 months from the last application. At the baseline and during every follow-up visit, the DH was measured with a pulp tester. A random intercept/random slope model was used to evaluate the effect of the treatment, at various times with respect to the initial diagnosis. Within the limits of the present study, Tiefenfluorid® was more effective than Enamelast™ against DH in that it provided long-lasting results, with a significant improvement still detected at the latest 6-month follow-up

Temporal variation in pollination services to Cucurbita moschata is determined by bee gender and diversity

It has been proposed that species-rich insect communities and species turnover across landscapes enhance the pollination efficiency of crops through complementarity, where both the dominant and less abundant species contribute to reaching a yield threshold from pollination. Alternatively, fluctuations in the most abundant pollinator species, rather than changes in species richness, may drive temporal variation in pollination services. In this study, we used Cucurbita moschata as a model to investigate temporal variation in pollinator communities in a Mexican tropical dry forest region. We sampled floral visitors in the coastal region of Jalisco during the wet and dry seasons and determined the pollination efficiency of all floral visitors. Our results showed that there was temporal variation in the pollinator community and in the pollination efficiency of the main pollinators of Cucurbita moschata crops. In the wet season, native bees of the genus Peponapis were the most frequent and effective pollinators of C. moschata, whereas in the dry season, Peponapis bees were scarce and Apis mellifera became the most frequent floral visitor. Apis mellifera transfers smaller pollen loads than Peponapis, but it provides an effective pollination service in conjunction with other native bees during the dry season. There was also an interaction between flower gender and pollinator species, where A. mellifera had higher visitation rate to female C. moschata flowers, and Peponapis bees to staminate flowers. Mean visitation rate by Peponapis female bees was 17 times higher than visitation rate by male bees. This is the first report of a vis-à-vis relationship of pollinator gender with respect to plant gender in which plants of the genus Cucurbita that produce unisexual staminate and pistillate flowers are differentially visited by Peponapis male and female bees, where females are the main pollinators. Understanding the temporal variation in pollinator communities and the contribution of the different species of pollinators to the reproductive success of different crop species and varieties can be crucial to maintaining pollination services under the current global pollination crisis.Fil: Delgado-Carrillo, Oliverio. Laboratorio Nacional de Análisis y Síntesis Ecológica; México. Universidad Nacional Autónoma de México; MéxicoFil: Martén-Rodríguez, Silvana. Laboratorio Nacional de Análisis y Síntesis Ecológica; MéxicoFil: Ashworth, Lorena. Laboratorio Nacional de Análisis y Síntesis Ecológica; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Aguilar, Ramiro. Laboratorio Nacional de Análisis y Síntesis Ecológica; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Lopezaraiza-Mikel, Martha. Universidad Autonoma de Guerrero; MéxicoFil: Quesada, Mauricio. Laboratorio Nacional de Análisis y Síntesis Ecológica; Méxic

Support for maternal manipulation of developmental nutrition in a facultatively eusocial bee, Megalopta genalis (Halictidae)

Developmental maternal effects are a potentially important source of phenotypic variation, but they can be difficult to distinguish from other environmental factors. This is an important distinction within the context of social evolution, because if variation in offspring helping behavior is due to maternal manipulation, social selection may act on maternal phenotypes, as well as those of offspring. Factors correlated with social castes have been linked to variation in developmental nutrition, which might provide opportunity for females to manipulate the social behavior of their offspring. Megalopta genalis is a mass-provisioning facultatively eusocial sweat bee for which production of males and females in social and solitary nests is concurrent and asynchronous. Female offspring may become either gynes (reproductive dispersers) or workers (non-reproductive helpers). We predicted that if maternal manipulation plays a role in M. genalis caste determination, investment in daughters should vary more than for sons. The mass and protein content of pollen stores provided to female offspring varied significantly more than those of males, but volume and sugar content did not. Sugar content varied more among female eggs in social nests than in solitary nests. Provisions were larger, with higher nutrient content, for female eggs and in social nests. Adult females and males show different patterns of allometry, and their investment ratio ranged from 1.23 to 1.69. Adult body weight varied more for females than males, possibly reflecting increased variation in maternal investment in female offspring. These differences are consistent with a role for maternal manipulation in the social plasticity observed in M. genalis

Reproductive Ecology and Severe Pollen Limitation in the Polychromic Tundra Plant, Parrya nudicaulis (Brassicaceae)

Pollen limitation is predicted to be particularly severe in tundra habitats. Numerous reproductive patterns associated with alpine and arctic species, particularly mechanisms associated with reproductive assurance, are suggested to be driven by high levels of pollen limitation. We studied the reproductive ecology of Parrya nudicaulis, a species with relatively large sexual reproductive investment and a wide range of floral pigmentation, in tundra habitats in interior montane Alaska to estimate the degree of pollen limitation. The plants are self-compatible and strongly protandrous, setting almost no seed in the absence of pollinators. Supplemental hand pollinations within pollinator exclusion cages indicated no cage effect on seed production. Floral visitation rates were low in both years of study and particularly infrequent in 2010. A diversity of insects visited P. nudicaulis, though syrphid and muscid flies composed the majority of all visits. Pollen-ovule ratios and levels of heterozygosity are consistent with a mixed mating system. Pollen limitation was severe; hand pollinations increased seed production per plant five-fold. Seed-to-ovule ratios remained low following hand pollinations, indicating resource limitation is likely to also be responsible for curtailing seed set. We suggest that pollen limitation in P. nudicaulis may be the result of selection favoring an overproduction of ovules as a bet-hedging strategy in this environmental context of highly variable pollen receipt