Oligodendrocyte differentiation and signaling after transferrin internalization: a mechanism of action

Oligodendrocytes are the cells producing the myelin membrane around the axons in the central nervous system and, although apotransferrin (aTf) is required for oligodendrocyte differentiation, the underlying mechanisms are not fully understood. Fyn tyrosine kinase, a member of the Src family of proteins, has been shown to play an important role in myelination by up-regulating the expression of myelin basic protein; however, a molecular link between aTf and Fyn kinase signaling pathway during oligodendrocytes differentiation has not been established yet. Our aim was to investigate whether Fyn kinase, MEK/ERK and PI3K/Akt signaling pathways are required for aTf-stimulation of oligodendrocyte differentiation and also to determine if the transferrin receptor is involved in these mechanisms. Treatment of primary cultures of oligodendroglial precursor cells with aTf leads to Fyn kinase activation by a mechanism that involves transferrin receptor. In turn, Fyn kinase activation promotes MEK-mediated transient phosphorylation of ERK1/2. On the other hand, transferrin receptor internalization also produces rapid and sustained activation of Akt, which involves phosphatidylinositol 3-kinase (PI3K) activation. Finally, aTf incorporated through clathrin-mediated endocytosis increases myelin basic protein, F3-contactin and β-tubulin through Fyn/MEK/ERK pathways, as well as an activation of the PI3K/Akt pathway. Our results also demonstrate that the activation of the pathways necessary for oligodendroglial precursor cell maturation is dependent on AP2 recruitment onto the plasma membrane for clathrin-mediated endocytosis of transferrin receptor.Fil: Perez, Maria Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Fisicoquímica Biológicas; Argentina; Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Departamento de Quimica Biologica. Cátedra de Química Biológica Patológica; Argentina;Fil: Fernandez, Natalia Cristina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Química Medicinal; Argentina;Fil: Pasquini, Juana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Fisicoquímica Biológicas; Argentina

Lactic acid bacteria isolated from poultry protect the intestinal epithelial cells of chickens from in vitro wheat germ agglutinin-induced cytotoxicity

Poultry fed on wheat-based diets regularly ingest wheat germ agglutinin (WGA) that has toxic effects in vitro on intestinal epithelial cells (IEC) obtained from 14-d-old broilers. Cytotoxicity and the potential role of 14 intestinal bacterial strains in the removal of bound lectins in epithelial cell cultures were investigated. Cytotoxicity was dependent on time and lectin concentration; the lethal dose (LD50) was 8.36 µg/ml for IEC exposed for 2 h to WGA. Complementary sugars to WGA were detected on the surface of one Enterococcus and 9 Lactobacillus strains isolated from poultry. These strains were evaluated as a lectin removal tool for cytotoxicity prevention. Incubation of lactic acid bacteria with WGA before IEC–lectin interaction caused a substantial reduction in the percentage of cell deaths. The protection was attributed to the amount of lectin bound to the bacterial surfaces and was strain-dependent. L. salivarius LET 201 and L. reuteri LET 210 were more efficient than the other lactic acid bacteria assayed. These results provide a basis for the development of probiotic supplements or cell-wall preparations of selected lactic acid bacteria intended to avoid harmful effects of a natural constituent of the grain in wheat-based diets.Fil: Babot, Jaime Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Argañaraz Martínez, Fernando Eloy. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Lorenzo Pisarello, Maria Jose. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Apella, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Perez Chaia, Adriana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentina. Universidad Nacional de Tucumán; Argentin

In vivo resorption of biomimetic hydroxyapatite/collagen composites: injectable cements versus pre-set microspheres

Postprint (published version

Lesson study as a tool for rebuilding teachers' practical thinking: a bridge between espoused theories and theories-in-use

This Lesson Study forms part of the research work carried out by the Spanish team, in order to analyse the potential of this professional teacher development methodology for the reconstruction of teachers' practical thinking. It is a qualitative research process which involves the monitoring of seven infant school teachers during two school cycles. The teachers developed a Lesson Study over this period, with a practical thinking case study being carried out both before and after. This paper focuses on the Lesson Study case study. The Lesson Study was developed independently by the group of teachers, who were advised throughout by the undersigned researchers. At the same time, the researchers carried out a case study focusing on the Lesson Study being developed by the teachers. Findings/Conclusions: - From the start of the Lesson Study, we can find evidence of changes in the practical thinking of the teachers involved, which led to immediate changes in their classroom practice. - The development of the Lesson Study brought about significant reflection with regards to the Infant Education curriculum, in some cases resulting in substantial modification to the way it is implemented in their different classrooms. - The teachers pointed out the value of cooperative work on several different occasions. - They also emphasised the high level of learning they achieved by observing how their colleagues developed the lesson designed by the group using different strategies and data collection instruments, such as documentation inspired by the Reggio Emilia approach, when reflecting on their own practice. On the whole, we can state that the cooperative design work of this lesson showed the contrast between the espoused theories of the participants and their theories-in-use, conditioned fundamentally by their work contexts and previous experience. Lesson Study is a way to bring these two poles closer together, enriching teachers with strategies to help detect contradictions in their practice and to resolve them and feel more comfortable with what they do.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Coup-TFII expression defines two different septum transversum cell compartments crucial to cardiac septation and compact ventricular wall growth

COUP-TFII encodes for an orphan nuclear receptor expressed by multiple embryonic tissues. COUP-TFII functions include the regulation of mesodermal progenitor differentiation and cell fate specification, and is required for completion of cardiovascular development as shown by the early death (E9.5) of COUP-TFII-null mice. In this study, we show that COUP-TFII, which is strongly expressed in the atrial myocardium, is also expressed in two different compartments of the septum transversum (ST, E9.5), a mesodermal folding adjacent to cardiac inflow myocardium. The first ST compartment is COUP-TFII+/Isl1+; cells in this compartment concentrate in the posterior part of the ST, overlap with SHF, and are continuous with the dorsal mesenchymal protrusion (DMP, also known as spina vestibuli). The second compartment is characteristically COUP-TFII+/Isl1-, and comprises the majority of proepicardial cells. To dissect the role of COUP-TFII+ ST cells in cardiac development, we conditionally deleted COUP-TFII in the ST using two different Cre constructs (Wt1Cre; G2-Gata4Cre). We show that COUP-TFII deletion in the ST is most severe in G2-Gata4Cre;COUP-TFII-/- mice, containing various cardiovascular progenitor lineages. Mutant mice display atrial septation and atrioventricular septal defects as well as a severe disruption of compact ventricular myocardial growth and coronary vascularization. We conclude that COUP-TFII plays critical, pleiotropic, tissue-dependent roles during cardiac septation, growth and vascularization.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Centro Nacional de Investigaciones Cardiovasculares (CNIC-ISCIII

Non-linear analyses to assess the seismic performance of RC buildings retrofitted with FRP

Post-seismic reinforcement is extensively used to repair structural elements of buildings hit by strong earthquakes, while pre-seismic reinforcement can be very convenient to improve the seismic performance of buildings designed according to less stringent standards than current. One of the most commonly used techniques for both pre and post-seismic retrofit of structures is that of wrapping elements previously identified as weak or damaged with sheets of fiber-reinforced polymers (FRP). This technique may be in fact more advantageous than other strengthening approaches, due to speed of placement, low environmental impact and small load increase. Non-linear methods of analysis can be very helpful for planning the retrofit strategy and assessing in advance its effectiveness. Based on non-linear static and dynamic numerical analyses, the effectiveness of the FRP pre-seismic reinforcement on the global performance of buildings was investigated in this paper with reference to a residential Italian building designed according to obsolete standards. The seismic capacity of the building, before and after the FRP retrofit, was assessed and the efficacy of the seismic rehabilitation was evaluated. The results show that, by improving the local resistance of the most vulnerable elements and the global ductility of the building, the FRP wrapping of the ground-floor columns of the considered building has an important impact on the overall seismic response of the structure, although it cannot entirely avoid undesirable global collapse mechanisms

Prácticas curativas y plantas medicinales: un acercamiento a la etnomedicina de San Nicolás, México.

Existe interés por las prácticas curativas de la medicina tradicional como forma de curación/ sanación alterna y complementaria. El objetivo del artículo es documentar las prácticas curativas y las plantas medicinales que actualmente se utilizan en una comunidad rural del Estado de México. Desde la etnomedicina, se abordan las explicaciones cognitivas de los sujetos que participan del binomio salud-enfermedad. Se utilizó el método etnográico para obtener y sistematizar información sobre las percepciones acerca de las prácticas curativas y plantas medicinales. Las prácticas son el resultado del conocimiento acumulado sobre el ambiente y se llevan a cabo por el interés de ayudar, más que por beneicio económico. Se concluye que la herbolaria es un indicativo de: 1) la pervivencia de la cosmovisión mesoamericana para tratar enfermedades de cuerpo y espíritu; 2) se privilegia una atención integral del paciente y 3) el ambiente físico que rodea a las personas es un botiquín bio-cultural

Treatment of impacted or retained second molars with the miniscrew-supported pole technique: a prospective follow-up study

Background: Eruption disturbances of permanent molars are uncommon; however, it is important to treat them as soon as they are diagnosed. The main objective was to analyze the effectiveness of the “miniscrew-supported pole technique,” a surgically assisted orthodontic procedure to force the eruption of impacted/retained second molars (M2s) when there are indicators of complex molar inclusion. An observational prospective study was carried out during a 2-year period. Sociodemographic, clinical and low-dose scanner variables were taken at baseline (T0). Follow-up variables (T1) were the time between surgery and tooth eruption, radiographic measurements, debonding of buttons, failure rate of miniscrews and success rate of eruption. Results: A total of 21 patients (mean age of 13.9 years) with 24 retained/impacted M2s were recruited; 13 molars were maxillary (54.2%) and 11 (45.8%) were mandibular. Six (25%) were impacted molars and 18 (75%) primarily retained. At T0, molar angulation was mesial in six molars (25%), distal in five molars (20.8%) and 13 molars were vertically positioned (54.2%). Infraocclusion degree was moderate in four (16.7%) molars and severe in 20 (83.3%). Only three (12.5%) third molars were removed due to lack of space. All M2s managed to erupt, achieving a success rate of 100%; however, two molars of the same patient did not achieve occlusion. The period of eruption after surgery was 126.8 (117.3) days. Anatomical radicular alteration was the only variable independently related to a longer time of treatment (p = 0.027). Conclusions: The pole technique, using one mesial miniscrew and simple orthodontic mechanics, applies forces that succeed in erupting complicated retained/impacted M2s in a short period of time and with a low failure rate

Treatment of impacted or retained second molars with the miniscrew-supported pole technique: a prospective follow-up study

Ectopic eruption; Molar angulation; Surgical procedureErupción ectópica; Angulación molar; Procedimiento quirúrgicoErupció ectòpica; Angulació molar; Procediment quirúrgicBackground Eruption disturbances of permanent molars are uncommon; however, it is important to treat them as soon as they are diagnosed. The main objective was to analyze the effectiveness of the “miniscrew-supported pole technique,” a surgically assisted orthodontic procedure to force the eruption of impacted/retained second molars (M2s) when there are indicators of complex molar inclusion. An observational prospective study was carried out during a 2-year period. Sociodemographic, clinical and low-dose scanner variables were taken at baseline (T0). Follow-up variables (T1) were the time between surgery and tooth eruption, radiographic measurements, debonding of buttons, failure rate of miniscrews and success rate of eruption. Results A total of 21 patients (mean age of 13.9 years) with 24 retained/impacted M2s were recruited; 13 molars were maxillary (54.2%) and 11 (45.8%) were mandibular. Six (25%) were impacted molars and 18 (75%) primarily retained. At T0, molar angulation was mesial in six molars (25%), distal in five molars (20.8%) and 13 molars were vertically positioned (54.2%). Infraocclusion degree was moderate in four (16.7%) molars and severe in 20 (83.3%). Only three (12.5%) third molars were removed due to lack of space. All M2s managed to erupt, achieving a success rate of 100%; however, two molars of the same patient did not achieve occlusion. The period of eruption after surgery was 126.8 (117.3) days. Anatomical radicular alteration was the only variable independently related to a longer time of treatment (p = 0.027). Conclusions The pole technique, using one mesial miniscrew and simple orthodontic mechanics, applies forces that succeed in erupting complicated retained/impacted M2s in a short period of time and with a low failure rate

ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES OF HYDROALCOHOLIC EXTRACTS FROM ALOYSIA POLYSTACHYA GRISEB MOLDENKE AND LIPPIA TURBINATA GRISEB (VERBENACEAE)

Objective: The aims of this study were to determine polyphenols and flavonoids composition, to evaluate the antioxidant and antibacterial activities and possible antibacterial synergistic effects of hydroalcoholic extracts of Aloysia polystachya and Lippia turbinata.Methods: The flavonoids analysis was carried out in ethyl acetate fractions by means of high-performance liquid chromatography coupled to electrospray ionization quadrupole time of flight mass spectrometry (HPLC-ESI-Q-TOF-MS). The phenolic content was measured using Folin Ciocalteu reagent. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical method was used to estimate the antioxidant capacity. The antibacterial activity was determined by the agar microdilution and broth microdilution methods. The checkerboard assay was carried out to determine possible antibacterial synergism.Results: Several flavonoid compounds were detected for the first time in these species, being Lippia turbinata extract the one that presented the highest total phenolic content and antioxidant activity. Extracts from both species would have bactericidal activity against Staphylococcus strains employed in this work. The extract combinations had a synergistic effect against three bacteria, one of them Gram-negative.Conclusion: These extracts have demonstrated antioxidant and antibacterial activity, and its combination showed a synergistic effect against methicillin-resistant Staphylococcus aureus. Biological activities would be attributed to the whole of phytochemical constituents present in the respective crude extracts. However, it could be considered that the found flavonoids play an important role in the development of these activities.Keywords: Aloysia polystachya, Antibacterial activity, Antioxidant activity, Flavonoids, Lippia turbinataÂ