RESUMEN
BACKGROUND: Focused cardiac ultrasound (FCU) is a helpful tool to rapidly identify right ventricular (RV) causes of hemodynamic instability and facilitate the initiation of therapy. The clinical value of existing course models often remains unclear. This study investigated the effects of a one-day FCU training on the visual estimation skills of RV characteristics. METHODS: Four residents were included as the study group after completing a standardized one-day FCU training. Four gender-matched controls did not take part in the training. All residents graded image quality, RV systolic function, and RV dimensions in a test comprising 35 ultrasound clips. RESULTS: The study and control group did not differ in ICU or ultrasound experience. Overall, training participants were able to distinguish between good and insufficient image quality significantly better than the control group (agreement 80.0% vs 61.4%, p = 0.04). The agreement for the estimation of RV function and RV dimensions was not different between the groups (63.2% vs 60.5%, p = 0.66 and 64.3% vs 67.1%, p = 0.18, respectively). Descriptively, only small differences were found between the groups for the estimation of RV function and RV dimensions in subgroups of patients with normal versus reduced systolic RV function or normal versus enlarged RV dimensions, respectively. Both groups struggled in identifying RV enlargement (34.6% vs 46.2%). DISCUSSION: In this study, a single one-day FCU training had no impact on residents' skills to visually assess systolic RV function or RV dimensions. Improvements of current training modalities or continuous teaching models are needed to optimize residency programs and patient care.
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Internado y Residencia , HumanosRESUMEN
Foragers of several species of stingless bees (Hymenoptera, Apidae and Meliponini) deposit pheromone marks in the vegetation to guide nestmates to new food sources. These pheromones are produced in the labial glands and are nest and species specific. Thus, an important question is how recruited foragers recognize their nestmates' pheromone in the field. We tested whether naïve workers learn a specific trail pheromone composition while being recruited by nestmates inside the hive in the species Scaptotrigona pectoralis. We installed artificial scent trails branching off from trails deposited by recruiting foragers and registered whether newly recruited bees follow these trails. The artificial trails were baited with trail pheromones of workers collected from foreign S. pectoralis colonies. When the same foreign trail pheromone was presented inside the experimental hives while recruitment took place a significant higher number of bees followed the artificial trails than in experiments without intranidal presentation. Our results demonstrate that recruits of S. pectoralis can learn the composition of specific trail pheromone bouquets inside the nest and subsequently follow this pheromone in the field. We, therefore, suggest that trail pheromone recognition in S. pectoralis is based on a flexible learning process rather than being a genetically fixed behaviour.
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Abejas/fisiología , Conducta Exploratoria/fisiología , Conducta Alimentaria/fisiología , Aprendizaje/fisiología , Atractivos Sexuales/fisiología , Olfato/fisiología , Animales , Conducta Animal/fisiología , Conducta Alimentaria/psicología , Conducta SocialRESUMEN
Reproductive division of labor in advanced eusocial honey bees and stingless bees is based on the ability of totipotent female larvae to develop into either workers or queens. In nearly all species, caste is determined by larval nutrition. However, the mechanism that triggers queen development in Melipona bees is still unresolved. Several hypotheses have been proposed, ranging from the proximate (a genetic determination of caste development) to the ultimate (a model in which larvae have complete control over their own caste fate). Here, we showed that the addition of geraniol, the main compound in labial gland secretions of nurse workers, to the larval food significantly increases the number of larvae that develop into queens. Interestingly, the proportion of queens in treated brood exactly matched the value (25%) predicted by the two-locus, two-allele model of genetic queen determination, in which only females that are heterozygous at both loci are capable of developing into queens. We conclude that labial gland secretions, added to the food of some cells by nurse bees, trigger queen development, provided that the larvae are genetically predisposed towards this developmental pathway. In Melipona beecheii, geraniol acts as a primer pheromone representing the first caste determination substance identified to date.
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Abejas/crecimiento & desarrollo , Terpenos/química , Monoterpenos Acíclicos , Animales , Cromatografía de Gases , Femenino , Larva/crecimiento & desarrollo , Glándulas Salivales/química , Predominio Social , Terpenos/farmacologíaRESUMEN
The ability to learn food odors inside the nest and to associate them with food sources in the field is of essential importance for the recruitment of nestmates in social bees. We investigated odor learning by workers within the hive and the influence of these odors on their food choice in the field in the stingless bee Scaptotrigona pectoralis. During the experiments, recruited bees had to choose between two feeders, one with an odor that was present inside the nest during the recruitment process, and one with an unknown odor. In all experiments with different odor combinations (linalool/phenylacetaldehyde, geraniol/eugenol) a significant majority of bees visited the feeder with the odor they had experienced in their nest (chi (2)-tests; p < 0.05). By contrast, the bees showed no preference for one of two feeders when they were either baited with the same odor (linalool) or contained no odor. Our results clearly show that naïve workers of S. pectoralis can learn the odor of a food source during the recruitment process from the nest atmosphere and that their subsequent food search in the field is influenced by the learned odor.
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Alimentación Animal , Abejas/fisiología , Conducta Alimentaria/fisiología , Aprendizaje/fisiología , Comportamiento de Nidificación , Odorantes , Conducta Social , Animales , Abejas/anatomía & histología , Femenino , Vivienda para Animales , SacarosaRESUMEN
MAGE derived HLA ligands have repeatedly been shown to elicit T-cell responses against tumor cells. In renal cell carcinoma (RCC), however, only few T-cell epitopes from cancer testis antigens have been described. To identify potential candidates, we applied a combined approach of microarray/qPCR expression analysis and sequencing of HLA ligands from RCC by mass spectrometry. We analyzed the expression of 21 MAGE genes in ten RCC samples and two glioblastoma samples and could identify the first MHC class I ligand NIGDEALIGRW from MAGED4 presented by HLA-A*25 on RCC solid tumor tissue. MAGED4 was expressed in 30% of RCC and both glioblastoma samples. Among the other MAGE family members only MAGEB2 and -C1 and the broadly expressed MAGED1, -D2, -F1 and -H1 were expressed in RCC. Ligands from MAGED4 could thus be interesting tumor-associated antigens in a subset of RCC, even though the identified ligand is presented by a rather rare allele.
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Antígenos de Neoplasias/metabolismo , Carcinoma de Células Renales/inmunología , Genes MHC Clase I , Antígenos HLA , Neoplasias Renales/inmunología , Péptidos/análisis , Antígenos de Neoplasias/química , Antígenos de Neoplasias/genética , Estudios de Casos y Controles , Humanos , Ligandos , Proteínas de Neoplasias/química , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismoRESUMEN
The lack of sufficient well-defined tumor-associated antigens is still a drawback on the way to a cytotoxic T-lymphocyte-based immunotherapy of renal cell carcinoma (RCC). We are trying to define a larger number of such targets by a combined approach involving HLA ligand characterization by mass spectrometry and gene expression profiling by oligonucleotide microarrays. Here, we present the results of a large-scale analysis of 13 RCC specimens. We were able to identify more than 700 peptides, mostly from self-proteins without any evident tumor association. However, some HLA ligands derived from previously known tumor antigens in RCC. In addition, gene expression profiling of tumors and a set of healthy tissues revealed novel candidate RCC-associated antigens. For several of them, we were able to characterize HLA ligands after extraction from the tumor tissue. Apart from universal RCC antigens, some proteins seem to be appropriate candidates in individual patients only. This underlines the advantage of a personalized therapeutic approach. Further analyses will contribute additional HLA ligands to this repertoire of universal as well as patient-individual tumor antigens.