Molecular Pharmacology of Gelsemium Alkaloids on Inhibitory Receptors.

Indole alkaloids are the main bioactive molecules of the Gelsemium genus plants. Diverse reports have shown the beneficial actions of Gelsemium alkaloids on the pathological states of the central nervous system (CNS). Nevertheless, Gelsemium alkaloids are toxic for mammals. To date, the molecular targets underlying the biological actions of Gelsemium alkaloids at the CNS remain poorly defined. Functional studies have determined that gelsemine is a modulator of glycine receptors (GlyRs) and GABAA receptors (GABAARs), which are ligand-gated ion channels of the CNS. The molecular and physicochemical determinants involved in the interactions between Gelsemium alkaloids and these channels are still undefined. We used electrophysiological recordings and bioinformatic approaches to determine the pharmacological profile and the molecular interactions between koumine, gelsemine, gelsevirine, and humantenmine and these ion channels. GlyRs composed of α1 subunits were inhibited by koumine and gelsevirine (IC50 of 31.5 ± 1.7 and 40.6 ± 8.2 µM, respectively), while humantenmine did not display any detectable activity. The examination of GlyRs composed of α2 and α3 subunits showed similar results. Likewise, GABAARs were inhibited by koumine and were insensitive to humantenmine. Further assays with chimeric and mutated GlyRs showed that the extracellular domain and residues within the orthosteric site were critical for the alkaloid effects, while the pharmacophore modeling revealed the physicochemical features of the alkaloids for the functional modulation. Our study provides novel information about the molecular determinants and functional actions of four major Gelsemium indole alkaloids on inhibitory receptors, expanding our knowledge regarding the interaction of these types of compounds with protein targets of the CNS.

Leukocyte- and Platelet-Rich Fibrin (L-PRF) Obtained from Smokers and Nonsmokers Shows a Similar Uniaxial Tensile Response In Vitro.

We evaluated and compared the biomechanical properties of Leukocyte-and Platelet Rich Fibrin L-PRF clots and membranes derived from smoker and nonsmoker donors. Twenty venous-blood donors (aged 18 to 50 years) were included after signing informed consent forms. L-PRF clots were analyzed and then compressed to obtain L-PRF membranes. L-PRF clot and membrane samples were tested in quasi-static uniaxial tension and the stress-stretch response was registered and characterized. Furthermore, scanning electron microscope representative images were taken to see the fibrin structure from both groups. The analysis of stress-stretch curves allowed us to evaluate the statistical significance in differences between smoker and nonsmoker groups. L-PRF membranes showed a stiffer response and higher tensile strength when compared to L-PRF clots. However, no statistically significant differences were found between samples from smokers and nonsmokers. With the limitations of our in vitro study, we can suggest that the tensile properties of L-PRF clots and membranes from the blood of smokers and nonsmokers are similar. More studies are necessary to fully characterize the effect of smoking on the biomechanical behavior of this platelet concentrate, to further encourage its use as an alternative to promote wound healing in smokers.

Amniotic fluid pulmonary embolism and COVID-19: Case report.

Amniotic fluid embolism is a rare complication of peripartum. It is caused by the entry of fetal components into the maternal systemic circulation. There are 2 main types: typical; it presents with the triad of hemodynamic collapse, respiratory distress and disseminated intravascular coagulation type coagulopathy, while atypical; disseminated intravascular coagulation does not occur. SARS CoV-2 infection causes coagulopathy due to the alteration of Virchow's triad and coagulation factors. We present the case of a 21-year-old pregnant woman who consulted for premature rupture of membranes, with an indication for cesarean section, and during surgery presented bradycardia, hypotension, and desaturation until cardiorespiratory arrest. An angiotomography showed amniotic fluid embolism associated with pulmonary edema, ruling out differential diagnoses associated with the disease, leaving as the only cause of the infection confirmed by COVID-19, which, it was inferred, was closely related to the immunological disorder suffered by the patient.

An updated examination of the perception of barriers for pharmacogenomics implementation and the usefulness of drug/gene pairs in Latin America and the Caribbean.

Pharmacogenomics (PGx) is considered an emergent field in developing countries. Research on PGx in the Latin American and the Caribbean (LAC) region remains scarce, with limited information in some populations. Thus, extrapolations are complicated, especially in mixed populations. In this paper, we reviewed and analyzed pharmacogenomic knowledge among the LAC scientific and clinical community and examined barriers to clinical application. We performed a search for publications and clinical trials in the field worldwide and evaluated the contribution of LAC. Next, we conducted a regional structured survey that evaluated a list of 14 potential barriers to the clinical implementation of biomarkers based on their importance. In addition, a paired list of 54 genes/drugs was analyzed to determine an association between biomarkers and response to genomic medicine. This survey was compared to a previous survey performed in 2014 to assess progress in the region. The search results indicated that Latin American and Caribbean countries have contributed 3.44% of the total publications and 2.45% of the PGx-related clinical trials worldwide thus far. A total of 106 professionals from 17 countries answered the survey. Six major groups of barriers were identified. Despite the region's continuous efforts in the last decade, the primary barrier to PGx implementation in LAC remains the same, the "need for guidelines, processes, and protocols for the clinical application of pharmacogenetics/pharmacogenomics". Cost-effectiveness issues are considered critical factors in the region. Items related to the reluctance of clinicians are currently less relevant. Based on the survey results, the highest ranked (96%-99%) gene/drug pairs perceived as important were CYP2D6/tamoxifen, CYP3A5/tacrolimus, CYP2D6/opioids, DPYD/fluoropyrimidines, TMPT/thiopurines, CYP2D6/tricyclic antidepressants, CYP2C19/tricyclic antidepressants, NUDT15/thiopurines, CYP2B6/efavirenz, and CYP2C19/clopidogrel. In conclusion, although the global contribution of LAC countries remains low in the PGx field, a relevant improvement has been observed in the region. The perception of the usefulness of PGx tests in biomedical community has drastically changed, raising awareness among physicians, which suggests a promising future in the clinical applications of PGx in LAC.

Modulation of GABAA receptors and of GABAergic synapses by the natural alkaloid gelsemine.

The Gelsemium elegans plant preparations have shown beneficial activity against common diseases, including chronic pain and anxiety. Nevertheless, their clinical uses are limited by their toxicity. Gelsemine, one of the most abundant alkaloids in the Gelsemium plants, have replicated these therapeutic and toxic actions in experimental behavioral models. However, the molecular targets underlying these biological effects remain unclear. The behavioral activity profile of gelsemine suggests the involvement of GABAA receptors (GABAARs), which are the main biological targets of benzodiazepines (BDZs), a group of drugs with anxiolytic, hypnotic, and analgesic properties. Here, we aim to define the modulation of GABAARs by gelsemine, with a special focus on the subtypes involved in the BDZ actions. The gelsemine actions were determined by electrophysiological recordings of recombinant GABAARs expressed in HEK293 cells, and of native receptors in cortical neurons. Gelsemine inhibited the agonist-evoked currents of recombinant and native receptors. The functional inhibition was not associated with the BDZ binding site. We determined in addition that gelsemine diminished the frequency of GABAergic synaptic events, likely through a presynaptic modulation. Our findings establish gelsemine as a negative modulator of GABAARs and of GABAergic synaptic function. These pharmacological features discard direct anxiolytic or analgesic actions of gelsemine through GABAARs but support a role of GABAARs on the alkaloid induced toxicity. On the other hand, the presynaptic effects of the alkaloid provide an additional mechanism to explain their beneficial effects. Collectively, our results contribute novel information to improve understanding of gelsemine actions in the mammalian nervous system.

Inhibition of the Glycine Receptor alpha 3 Function by Colchicine.

Colchicine is a plant alkaloid that is widely used as a therapeutic agent. It is widely accepted that colchicine reduces the production of inflammatory mediators mainly by altering cytoskeleton dynamics due to its microtubule polymerization inhibitory activity. However, other lines of evidence have shown that colchicine exerts direct actions on the function of ion channels, which are independent of cytoskeleton alterations. Colchicine is able to modify the function of several pentameric ligand-gated ion channels, including glycine receptors (GlyRs). Previous electrophysiological studies have shown that colchicine act as an antagonist of GlyRs composed by the α 1 subunit. In addition, it was recently demonstrated that colchicine directly bind to the α 3 subunit of GlyRs. Interestingly, other studies have shown a main role of α 3GlyRs on chronic inflammatory pain. Nevertheless, the functional effects of colchicine on the α 3GlyR function are still unknown. Here, by using electrophysiological techniques and bioinformatics, we show that colchicine inhibited the function of the α 3GlyRs. Colchicine elicited concentration-dependent inhibitory effects on α 3GlyRs at micromolar range and decreased the apparent affinity for glycine. Single-channel recordings show that the colchicine inhibition is associated with a decrease in the open probability of the ion channel. Molecular docking assays suggest that colchicine preferentially bind to the orthosteric site in the closed state of the ion channel. Altogether, our results suggest that colchicine is a competitive antagonist of the α 3GlyRs.

Clinical Effectiveness of Bulk-Fill and Conventional Resin Composite Restorations: Systematic Review and Meta-Analysis.

The objective of this systematic review and meta-analysis was to determine the clinical effectiveness of bulk-fill and conventional resin in composite restorations. A bibliographic search was carried out until May 2020, in the biomedical databases Pubmed/MEDLINE, EMBASE, Scopus, CENTRAL and Web of Science. The study selection criteria were: randomized clinical trials, in English, with no time limit, with a follow-up greater than or equal to 6 months and that reported the clinical effects (absence of fractures, absence of discoloration or marginal staining, adequate adaptation marginal, absence of post-operative sensitivity, absence of secondary caries, adequate color stability and translucency, proper surface texture, proper anatomical form, adequate tooth integrity without wear, adequate restoration integrity, proper occlusion, absence of inflammation and adequate point of contact) of restorations made with conventional and bulk resins. The risk of bias of the study was analyzed using the Cochrane Manual of Systematic Reviews of Interventions. Sixteen articles were eligible and included in the study. The results indicated that there is no difference between restorations with conventional and bulk resins for the type of restoration, type of tooth restored and restoration technique used. However, further properly designed clinical studies are required in order to reach a better conclusion.

Modulation of glycine receptor single-channel conductance by intracellular phosphorylation.

Glycine receptors (GlyRs) are anion-permeable pentameric ligand-gated ion channels (pLGICs). The GlyR activation is critical for the control of key neurophysiological functions, such as motor coordination, respiratory control, muscle tone and pain processing. The relevance of the GlyR function is further highlighted by the presence of abnormal glycinergic inhibition in many pathophysiological states, such as hyperekplexia, epilepsy, autism and chronic pain. In this context, previous studies have shown that the functional inhibition of  GlyRs containing the α3 subunit is a pivotal mechanism of pain hypersensitivity. This pathway involves the activation of EP2 receptors and the subsequent PKA-dependent phosphorylation of α3GlyRs within the intracellular domain (ICD), which decrease the GlyR-associated currents and enhance neuronal excitability. Despite the importance of this mechanism of glycinergic dis-inhibition associated with dysfunctional α3GlyRs, our current understanding of the molecular events involved is limited. Here, we report that the activation of PKA signaling pathway decreases the unitary conductance of α3GlyRs. We show in addition that the substitution of the PKA-targeted serine with a negatively charged residue within the ICD of α3GlyRs and of chimeric receptors combining bacterial GLIC and α3GlyR was sufficient to generate receptors with reduced conductance. Thus, our findings reveal a potential biophysical mechanism of glycinergic dis-inhibition and suggest that post-translational modifications of the ICD, such as phosphorylation, may shape the conductance of other pLGICs.

Pentameric Ligand-Gated Ion Channels as Pharmacological Targets Against Chronic Pain.

Chronic pain is a common detrimental condition that affects around 20% of the world population. The current drugs to treat chronic pain states, especially neuropathic pain, have a limited clinical efficiency and present significant adverse effects that complicates their regular use. Recent studies have proposed new therapeutic strategies focused on the pharmacological modulation of G-protein-coupled receptors, transporters, enzymes, and ion channels expressed on the nociceptive pathways. The present work intends to summarize recent advances on the pharmacological modulation of pentameric ligand-gated ion channels, which plays a key role in pain processing. Experimental data have shown that novel allosteric modulators targeting the excitatory nicotinic acetylcholine receptor, as well as the inhibitory GABAA and glycine receptors, reverse chronic pain-related behaviors in preclinical assays. Collectively, these evidences strongly suggest the pharmacological modulation of pentameric ligand-gated ion channels is a promising strategy towards the development of novel therapeutics to treat chronic pain states in humans.

2-Phenylethanol and 2-phenylethylacetate production by nonconventional yeasts using tequila vinasses as a substrate.

Vinasses from the tequila industry are wastewaters with highly elevated organic loads. Therefore, to obtain value-added products by yeast fermentations, such as 2-phenylethanol (2-PE) and 2-phenylethylacetate (2-PEA), could be interesting for industrial applications from tequila vinasses. In this study, four yeasts species (Wickerhamomyces anomalus, Candida glabrata, Candida utilis, and Candida parapsilosis) were evaluated with two different chemically defined media and tequila vinasses. Differences in the aroma compounds production were observed depending on the medium and yeast species used. In tequila vinasses, the highest concentration (65 mg/L) of 2-PEA was reached by C. glabrata, the inhibitory compounds decreased biomass production and synthesis of 2-PEA, and biochemical and chemical oxygen demands were reduced by more than 50 %. Tequila vinasses were suitable for the production of 2-phenylethylacetate by the shikimate pathway. A metabolic network was developed to obtain a guideline to improve 2-PE and 2-PEA production using flux balance analysis (FBA).

Inhibitory Actions of Tropeines on the α3 Glycine Receptor Function.

Glycine receptors (GlyRs) are chloride-permeable pentameric ligand-gated ion channels. The inhibitory activity of GlyRs is essential for many physiological processes, such as motor control and respiration. In addition, several pathological states, such as hyperekplexia, epilepsy, and chronic pain, are associated with abnormal glycinergic inhibition. Recent studies have pointed out that positive allosteric modulators targeting the GlyR α3 subunit (α3GlyR) displayed beneficial effects in chronic pain models. Interestingly, previous electrophysiological studies have shown that tropeines, which are a family of synthetic antagonists of the serotonin type 3 receptors (5-HT3Rs), potentiate the activity of GlyRs conformed by α1 subunits. However, despite its importance as a pharmacological target in chronic pain, it is currently unknown whether the α3GlyR function is modulated by tropeines. Using electrophysiological techniques and molecular docking simulations, here we show that tropeines are inhibitors of the α3GlyR function. Tropisetron, a prototypical tropeine, exerted concentration-dependent inhibitory effects on α3GlyRs at the low micromolar range. In addition, three other tropeines showed similar effects. Single-channel recordings show that tropisetron inhibition is associated with a decrease in the open probability of the ion channel. Molecular docking assays suggest that tropeines preferentially bind to an agonist-free, closed state of the ion channel. The tropeine binding occurs in a discrete pocket around the vicinity of the orthosteric site within the extracellular domain of α3GlyR. Thus, our results describe the pharmacological modulation of tropeines on α3GlyRs. These findings may contribute to the development of GlyR-selective tropeine derivatives for basic and/or clinical applications.

Large Intracellular Domain-Dependent Effects of Positive Allosteric Modulators on Glycine Receptors.

Glycine receptors (GlyRs) are members of the pentameric ligand-gated ionic channel family (pLGICs) and mediate fast inhibitory neurotransmission in the brain stem and spinal cord. The function of GlyRs can be modulated by positive allosteric modulators (PAMs). So far, it is largely accepted that both the extracellular (ECD) and transmembrane (TMD) domains constitute the primary target for many of these PAMs. On the other hand, the contribution of the intracellular domain (ICD) to the PAM effects on GlyRs remains poorly understood. To gain insight about the role of the ICD in the pharmacology of GlyRs, we examined the contribution of each domain using a chimeric receptor. Two chimeras were generated, one consisting of the ECD of the prokaryotic homologue Gloeobacter violaceus ligand-gated ion channel (GLIC) fused to the TMD of the human α1GlyR lacking the ICD (Lily) and a second with the ICD (Lily-ICD). The sensitivity to PAMs of both chimeric receptors was studied using electrophysiological techniques. The Lily receptor showed a significant decrease in the sensitivity to four recognized PAMs. Remarkably, the incorporation of the ICD into the Lily background was sufficient to restore the wild-type α1GlyR sensitivity to these PAMs. Based on these data, we can suggest that the ICD is necessary to form a pLGIC having full sensitivity to positive allosteric modulators.

Comparison of the clinical effect of the adhesive strategies of universal adhesives in the treatment of non-carious cervical lesions: systematic review and meta-analysis

Objective: to compare, through a systematic review and a meta-analysis, the clinical effect of the adhesive strategies of universal adhesives (UA) in the treatment of non-carious cervical lesions (NCCLs). material and method: a search of the literature was carried out up to january 2018, in the biomedical databases: Pubmed, Embase, Scielo, Science Direct, SIGLE, LILACS, BBO, Google Scholar and the Central Register of Cochrane Clinical Trials. the selection criteria of the studies were as: randomized clinical trials, with a maximum age of 5 years and which report the clinical effects (marginal adaptation, discoloration or marginal staining, presence of secondary caries, postoperative sensitivity, retention and fractures) of the UA in the treatment of NCCLs. the risk of study bias was analyzed through the Cochrane Handbook of systematic reviews of interventions. results: the search strategy resulted in eight articles that reported no difference in marginal adaptation, discoloration or marginal staining, presence of secondary caries and postoperative sensitivity among the adhesive strategies of the UA; however they reported a difference between the retention and the presence of fractures, with the conventional adhesive strategy resulting in a better clinical effect. conclusion: the reviewed literature suggests that the conventional adhesive strategy of UAs results in greater retention and absence of fractures in the treatment of NCCLs.

Functional modulation of glycine receptors by the alkaloid gelsemine.

BACKGROUND AND PURPOSE: Gelsemine is one of the principal alkaloids produced by the Gelsemium genus of plants belonging to the Loganiaceae family. The extracts of these plants have been used for many years, for a variety of medicinal purposes. Coincidentally, recent studies have shown that gelsemine exerts anxiolytic and analgesic effects on behavioural models. Several lines of evidence have suggested that these beneficial actions were dependent on glycine receptors, which are inhibitory neurotransmitter-gated ion channels of the CNS. However, it is currently unknown whether gelsemine can directly modulate the function of glycine receptors. EXPERIMENTAL APPROACH: We examined the functional effects of gelsemine on glycine receptors expressed in transfected HEK293 cells and in cultured spinal neurons by electrophysiological techniques. KEY RESULTS: Gelsemine directly modulated recombinant and native glycine receptors and exerted conformation-specific and subunit-selective effects. Gelsemine modulation was voltage-independent and was associated with differential changes in the apparent affinity for glycine and in the open probability of the ion channel. In addition, the alkaloid preferentially targeted glycine receptors in spinal neurons and showed only minor effects on GABAA and AMPA receptors. Furthermore, gelsemine significantly diminished the frequency of glycinergic and glutamatergic synaptic events without altering the amplitude. CONCLUSIONS AND IMPLICATIONS: Our results provide a pharmacological basis to explain, at least in part, the glycine receptor-dependent, beneficial and toxic effects of gelsemine in animals and humans. In addition, the pharmacological profile of gelsemine may open new approaches to the development of subunit-selective modulators of glycine receptors.

Subcontratación en el sector forestal maderero chileno e impacto del manejo forestal sustentable implementado en empresa mandante sobre el clima organizacional: Un estudio de caso / Subcontracting in the forestry and timber industry of Chile and the impact of thr sustainable forestry management implemented in the principal company over the organizational climate: A case study

Las exigencias en la industria forestal están enfocadas a alcanzar estándares de productividad y un desempeño socialmente responsable con las comunidades, trabajadores y empresas contratistas. Al igual que en otros sectores, ha habido una importante especialización funcional que ha llevado a las grandes empresas a externalizar parte de sus procesos de la cadena productiva, generando importantes vínculos con empresas contratistas, quienes deben cumplir nuevos estándares internacionales. Es por ello que estas últimas deben preocuparse de generar las condiciones adecuadas para sus trabajadores y su productividad, donde la implementación de un estándar de manejo forestal sustentable podría incidir en cambios organizacionales en una empresa. Esta investigación recoge el caso de una empresa contratista de servicios forestales que concentra sus operaciones en la Región del Bío-Bío en Chile, aplicando una herramienta de diagnóstico de clima organizacional mediante encuestas al personal de faena, la que mide las percepciones que tienen los individuos de su lugar de trabajo bajo el enfoque de Koys y Decottis (1991) adaptado en la investigación realizada por Chiang et al. (2010). Con un Alpha de Cronbach de 0,80, destaca que la percepción de los encuestados en promedio como bueno (De acuerdo) y se ubica en 3,86 puntos. A su vez, se evidencia un número importante de respuestas, lo cual abre un debate sobre los factores consultados. Por tanto, el clima organizacional constituye una más de las dimensiones que está afectando los procesos de certificación, especialmente la incidencia de las empresas contratistas sobre las mandantes.

The requirements in the forestry industry are focused on reaching productivity standards and a socially responsible performance towards communities, workers and subcontracting companies. Just as in other sectors, an important functional specialization has occurred, and this has forced the big companies to outsource parts of their production chain processes, generating important links with subcontracting companies, which must meet new international standards. That is the reason why the latter must be concerned about generating the suitable conditions for their workers and their productivity, where the implementation of a sustainable forestry management standard could have an impact on the organizational changes in a company. This investigation takes the case of a forestry services subcontracting company that concentrates its operations in the Bio-Bio region in Chile, using an organizational environment evaluation tool through surveys answered by workers that measures the perceptions that individuals have about their working place under the Koys and Decottis (1991) approach, adapted in the investigation made by Chiang et al. (2010). With Cronbach's alpha of 0,80, highlights that the average perception of the survey respondents was good (Agrees) and it is placed at 3,86 points. At the same time, an important number of "I am not sure" answers are shown which opens the debate around the asked factors. Therefore, the organizational environment constitutes one of the dimensions that are affecting the certification processes, specially the impact of the contracting companies on the principal companies.

Importancia del acabado y pulido en restauraciones directas de resina compuesta en piezas dentarias anteriores. Reporte de Caso / Importance of finishing and polishing direct restorations of resin composite in anterior teeth. Case Report

Las restauraciones directas con resina compuesta realizadas en nuestros pacientes requieren mucha pericia por parte del operador, y a pesar que, a pesar que en muchos de los casos cumplimos con los protocolos adhesivos requeridos y la inserción correcta del material en la preparación; sin embargo, luego de realizar todo el proceso restaurador, dedicamos muy poco tiempo al acabado y pulido siendo este paso fundamental para lograr el éxito. Muchos no logramos obtener resultados satisfactorios al utilizar un sistema de acabado y pulido porque no sabemos utilizarlo adecuadamente, no sabemos cuánto tiempo dura el proceso, cual es la secuencia correcta o que aislante térmico utilizar. En el presente artículo se detalla la resolución de un caso clínico a través de un método de acabado y pulido de restauraciones directas sobre resina compuesta en el sector anterior. Los resultados obtenidos fueron satisfactorios ya que se pudo mejorar las restauraciones devolviendo la naturalidad, estética y función perdida preservando la vitalidad pulpar a través de protocolos conservadores. Concluimos, que el proceso de acabado y pulido de las restauraciones con resina compuesta es fundamental para garantizar el éxito del tratamiento, debemos de conocer a cabalidad el sistema de pulido para no injuriar la pulpa dental y así no perjudicar su vitalidad...

Direct composite resin restorations performed in our patients require much expertise by the operator and in many cases we comply with the required adhesive protocols and the correct inclusion of the material in the preparation, but after the restorative process we dedicate very little time to the finishing touch and polish this being a fundamental step for success. Many fail to obtain satisfactory results by using a system of finishing and polishing because we donÆt use it properly, do not know how long the process takes, or which is the correct sequence or insulation to use. This article details the resolution of a clinical case through a method of finishing and polishing of restorations on direct composite resin in the anterior teeth. The results obtained were satisfactory since they failed to improve restorations returning natural, aesthetic and lost function preserving the vitality pulp through conservative protocols. We conclude that the process of finishing and polishing our composite resin restorations was crucial to ensure the success of our treatments, but we must know perfectly and adequately the system used so as not to injure the dental pulp and thus not jeopardize its vitality...

Poste anatómico û reporte de caso / Anatomic post û case report

Con la técnica del poste anatómico se logra copiar la morfología interna del conducto radicular utilizando resina compuesta sobre un poste de fibra de vidrio, de esta manera se logra reducir el espesor del cemento mejorando su adaptación y, por consiguiente, mejor retención En el artículo se registra la confección de un poste anatómico en la resolución de un caso clínico en una pieza dentaria anteroinferior. Los resultados fueron satisfactorios para el paciente ya que se logró restaurar la pieza dentaria para la futura confección de una prótesis parcial fija. Conclusiones: Los postes de fibra de vidrio carecen de un factor fundamental que es el no seguir la morfología interna del conducto radicular y esto trae como consecuencia una mayor cantidad del agente cementante a ese nivel, por consiguiente, mayor riesgo en formación de burbujas o vacíos que pueden afectar la retención y estabilidad del poste...

With the technology of the anatomical post it is achieved to copy the internal morphology of the root canal using composite resin on a post of glass fiber, hereby it is achieved to reduce the thickness of the cement improving the adjustment of the same one and consequently better retention. In this article the confection of an anatomical post in the resolution of a clinical case in a front inferior dental piece is registered. The results were satisfactory for the patient since it was achieved to restore the dental piece for the future confection of a partial fixed prothesis. The posts of glass fiber lack a fundamental factor that is not to follow the internal morphology of the root canal and this brings as consequence a major quantity of the cementing agent to this level, consequently major risk in formation of bubbles or emptinesses that can affect the retention and stability of the post...

Ventilación nasofaríngea versus presión positiva continua de la vía aérea nasal como método ventilatorio de rescate: Reporte preliminar / Nasopharyngeal ventilation versus nasal continuous positive airway pressure as rescue ventilatory method: Preliminary report

Objetivo: Comparar la presión continua positiva de la vía aérea nasal y la ventilación nasofaríngea. Material y métodos: Ensayo clínico aleatorizado que incluyó a todos los recién nacidos admitidos a la Unidad de Cuidados Intensivos Neonatales del INPer que presentaron dificultad respiratoria y requerían soporte ventilatorio. Se incluyeron 28 individuos, divididos en dos grupos: el primero de 12 pacientes, manejado con ventilación nasofaríngea, y el segundo de 16 pacientes, tratados con presión positiva continua de la vía aérea nasal. Criterios de inclusión: Neonatos con dificultad respiratoria y automatismo respiratorio que requerían apoyo ventilatorio. Criterios de exclusión: Patología nasal, malformaciones congénitas mayores, trastorno neuromuscular, síndrome de fuga aérea y antecedente de cirugía o patología de abdomen. Variables: edad gestacional, peso, días de vida, enfermedad de fondo, método ventilatorio previo, días de aplicación de la ventilación, indicación del método de ventilación, complicaciones, tasa de éxito. Se usó estadística descriptiva y para la comparación de los grupos χ² o U de Mann-Whitney. Resultados: En el grupo de ventilación nasofaríngea hubo nueve neonatos pretérmino hipotróficos, mientras que en el grupo de presión positiva continua de la vía aérea nasal hubo seis neonatos pretérmino hipotróficos. Todos los neonatos ingresaron al estudio en fase I de ventilación. La indicación predominante para la aplicación del método de rescate en el grupo de ventilación nasofaríngea fue apnea, y en el grupo de presión positiva continua de la vía aérea nasal, dificultad respiratoria. La ventilación nasofaríngea falló en cinco pacientes (41.6%) y la presión positiva continua de la vía aérea nasal en tres (18.7%), sin haber diferencia estadística.

Objective: To compare the nasal continuous positive airway pressure and nasopharyngeal ventilation. Methods: Randomized clinical trial that included all infants admitted at the Neonatal Intensive Care Unit of the INPer, who had respiratory distress and required ventilatory support. In total were included 28 neonates, divided into two groups, the first with 12 patients with nasopharyngeal ventilation, and the second with 16 neonates in nasal continuous positive airway pressure. Inclusion criteria: Infants with respiratory distress and respiratory automatism that required ventilatory support. Exclusion criteria: Nasal pathology, major congenital malformations, neuromuscular disorder, air leak syndrome, previous abdominal surgery or intestinal disease. Study variables: gestational age, weight, days of life, underlying disease, prior ventilatory support method of ventilation, days of application, indications, complications, rate of success. We used descriptive statistics and for comparison of the groups χ2 or Mann-Whitney U. Results: The group with nasopharyngeal ventilation had nine preterm hypotrophic neonates; the group in nasal continuous positive airway pressure had six preterm hypotrophic neonates. At the moment of admission to the study all the neonates were in phase I of ventilation. The predominant indication of ventilation at the nasopharyngeal ventilation group was apnea, and respiratory distress for nasal continuous positive airway pressure group. Nasopharyngeal ventilation failed in five patients (41.6%) and three (18.7%) in nasal continuous positive airway pressure group, without statistical difference.

Reporte de caso: clareamiento dental en el consultorio / In office tooth whithening - case report

En la actualidad existen diversas técnicas para realizar procedimientos de clareamiento dental y es importante poder dominar estas técnicas dado que los pacientes cada vez más exigen estos procedimientos. El uso de materiales y procedimientos adecuados en la atención clínica cobra vital importancia para garantizar el éxito de nuestros procedimientos. En el presente artículo se detalla el procedimiento de clareamiento en el consultorio con peróxido de hidrógeno al 35% en la resolución de un caso clínico. El objetivo fue mejorar la estética de las piezas dentarias realizando un procedimiento de clareamiento dental. Los resultados fueron satisfactorios para el paciente, ya que se puede clarear los dientes de la paciente logrando una totalidad más acorde con su edad. Se puede concluir que el manejo adecuado del clareamiento de consultorio ofrece una alternativa segura y eficaz en estas situaciones clínicas.

At present there are diverse techniques to do bleaching procedures and it is important to be able to control these techniques because of patients demand these procedures more often than before. Using adecuate materials and procedures in the clinical attention it is very important to guarantee the success of our procedures. This article referes the procedures. This article referes the procedure of in-office bleaching with peroxide to 35% in the resolution of one clinical case. It aimed to improve the aesthetics of the dental pieces by bleaching procedure. The results were satisfactory for the patient because of his teeth could be whitened achieving a tonality more according to her age. It is possible to conclude that the suitable managing of in-office bleaching offers a safe and effective alternative in these clinical situations.

Odontología social: desigualdad social y salud / Social dentistry: social inequality and health

En la mayoría de los países los programas de atención odontológica se centran en aspectos tecnológicos y curativos de la odontología, en lugar de fomentar la prevención y los programas comunitarios de salud oral, que se muestran como estartegias más eficaces para mejorar la salud oral comunitaria y tendrían un mayor efecto sobre el estado de salud bucodental de una comunidad. Precisamente, a partir de esta constatación, se propone la alternativa de la odontología social y se discute sus alcances.

In most countries the programs of dental attention centre on technological and curative aspects of dentistry, instead of promoting the prevention and the community programs of dental health, wich appear as more effective strategies to improve the oral community health. It would have a bigger effect on the oral health of a community. Based in this reality, the alternative of social dentistry and his scopes are discussed.