The initiation knot is a signaling center required for molar tooth development.

Signaling centers, or organizers, regulate many aspects of embryonic morphogenesis. In the mammalian molar tooth, reiterative signaling in specialized centers called enamel knots (EKs) determines tooth patterning. Preceding the primary EK, transient epithelial thickening appears, the significance of which remains debated. Using tissue confocal fluorescence imaging with laser ablation experiments, we show that this transient thickening is an earlier signaling center, the molar initiation knot (IK), that is required for the progression of tooth development. IK cell dynamics demonstrate the hallmarks of a signaling center: cell cycle exit, condensation and eventual silencing through apoptosis. IK initiation and maturation are defined by the juxtaposition of cells with high Wnt activity to Shh-expressing non-proliferating cells, the combination of which drives the growth of the tooth bud, leading to the formation of the primary EK as an independent cell cluster. Overall, the whole development of the tooth, from initiation to patterning, is driven by the iterative use of signaling centers.

p75 Neurotrophin Receptor Signaling Activates Sterol Regulatory Element-binding Protein-2 in Hepatocyte Cells via p38 Mitogen-activated Protein Kinase and Caspase-3.

Nerve growth factor (NGF) influences the survival and differentiation of a specific population of neurons during development, but its role in non-neuronal cells has been less studied. We observed here that NGF and its pro-form, pro-NGF, are elevated in fatty livers from leptin-deficient mice compared with controls, concomitant with an increase in low density lipoprotein receptors (LDLRs). Stimulation of mouse primary hepatocytes with NGF or pro-NGF increased LDLR expression through the p75 neurotrophin receptor (p75NTR). Studies using Huh7 human hepatocyte cells showed that the neurotrophins activate the sterol regulatory element-binding protein-2 (SREBP2) that regulates genes involved in lipid metabolism. The mechanisms for this were related to stimulation of p38 mitogen-activated protein kinase (p38 MAPK) and activation of caspase-3 and SREBP2 cleavage following NGF and pro-NGF stimulations. Cell fractionation experiments showed that caspase-3 activity was increased particularly in the membrane fraction that harbors SREBP2 and caspase-2. Experiments showed further that caspase-2 interacts with pro-caspase-3 and that p38 MAPK reduced this interaction and caused caspase-3 activation. Because of the increased caspase-3 activity, the cells did not undergo cell death following p75NTR stimulation, possibly due to concomitant activation of nuclear factor-κB (NF-κB) pathway by the neurotrophins. These results identify a novel signaling pathway triggered by ligand-activated p75NTR that via p38 MAPK and caspase-3 mediate the activation of SREBP2. This pathway may regulate LDLRs and lipid uptake particularly after injury or during tissue inflammation accompanied by an increased production of growth factors, including NGF and pro-NGF.

XEN 63 gel stent device in glaucoma surgery: A 5-years follow-up prospective study.

PURPOSE: To evaluate the efficacy and safety of the XEN63 Gel Stent in patients with open-angle glaucoma (OAG). METHODS: Prospective, nonrandomized, open-label, not-controlled, and single center study conducted on OAG patients who underwent glaucoma surgery with the XEN63 gel stent. The main outcome measure was intraocular pressure (IOP). Secondary end-points were number of topical ocular hypotensive drugs, percentage of patients achieving an IOP reduction ⩾20%, and treatment-related adverse events. RESULTS: Eleven eyes from 11 patients were treated with XEN 63. Mean (95% confidence interval, CI) age was 78.8 (73.7-85.9). Two eyes (18.2%) underwent XEN alone, while nine eyes (81.8%) underwent combined XEN + cataract extraction (phacoemulsification). The median (95% CI) IOP reduction was 17.7% (-13.3% to 34.9%). At the end of the study 9 (81.8%) eyes had an IOP ⩽ 18 mm Hg, six of them without treatment. Six (54.6%) eyes obtained an IOP reduction ⩾20%. Compared to baseline, there was a significant reduction in the number of ocular hypotensive drugs (p = 0.0039). There were no treatment-related serious adverse events. Early postoperative complications included diplopia (1), blood in endothelium (2), ocular hypertension (1), corneal edema (1), folds in Descemet's membrane (1), and contact between the implant and the iris (1). All the adverse events were successfully solved without sequalae. One eye required bleb needling. CONCLUSION: The XEN63 implant significantly reduced both IOP and the amount of ocular hypotensive medications while maintaining a good safety profile.

Live Tissue Imaging Sheds Light on Cell Level Events During Ectodermal Organ Development.

Embryonic development of ectodermal organs involves a very dynamic range of cellular events and, therefore, requires advanced techniques to visualize them. Ectodermal organogenesis proceeds in well-defined sequential stages mediated by tissue interactions. Different ectodermal organs feature shared morphological characteristics, which are regulated by conserved and reiterative signaling pathways. A wealth of genetic information on the expression patterns and interactions of specific signaling pathways has accumulated over the years. However, the conventional developmental biology methods have mainly relied on two-dimensional tissue histological analyses at fixed time points limiting the possibilities to follow the processes in real time on a single cell resolution. This has complicated the interpretation of cause and effect relationships and mechanisms of the successive events. Whole-mount tissue live imaging approaches are now revealing how reshaping of the epithelial sheet for the initial placodal thickening, budding morphogenesis and beyond, involve coordinated four dimensional changes in cell shapes, well-orchestrated cell movements and specific cell proliferation and apoptosis patterns. It is becoming evident that the interpretation of the reiterative morphogenic signals takes place dynamically at the cellular level. Depending on the context, location, and timing they drive different cell fate choices and cellular interactions regulating a pattern of behaviors that ultimately defines organ shapes and sizes. Here we review how new tissue models, advances in 3D and live tissue imaging techniques have brought new understanding on the cell level behaviors that contribute to the highly dynamic stages of morphogenesis in teeth, hair and related ectodermal organs during development, and in dysplasia contexts.

Atención de Enfermería frente al Manejo Postoperatorio de Fracturas Oseas / Nursing Care in the Face of Postoperative Management of Fractures Bone

Objetivo: Describir la atención de enfermería en pacientes postoperados por fracturas hospitalización dentro del Hospital de Especialidades San Bartolo.Metodología:La investigación se enmarca en un enfoque cuantitativo, con un nivel de recolección de datos empleada fue la encuesta, a través de un cuestionario de 15 preguntas cerradas, que fue aplicado a una población de 24 enfermeros (as).Resultados: Entre los resultados más resaltantes, se evidencia desfavorablemente que el 100% de los encuestados omite cuidados, como lo es el control de líquidos a los pacientes, población considero que la administración de medicamentos es el cuidado principal en el postoperatorio medConclusiones: Las fracturas óseas representan un problema de discapacidad funcional en los pacientes y es necesario que el cuidado de enfermería se dirija a satisfacer los requerimientos del paciente sin afectar la inmovilidad intencional que se establece como medida terapéutica operatoria

Objective: To describe the nursing care in patients postoperated by bone fractures in the in the San Bartolo Specialties Hospital.Methodology: The research is framed in a quantitative approach, with a descriptive technique used was the survey, through a questionnaire of 15 closed questions, which was applied to a population of 24 nurses.Results: Among the most outstanding results, it is unfavorably shown that 100% of do not identify the warning signs, however, 75% of the population considered that the administration of medications is the main care in the postoperative period.Conclusions: Bone fractures represent a problem of functional disability in patients and it is necessary that nursing care is aimed at satisfying the patient's requirements without