Synaptotagmin-7 facilitates acetylcholine release in splanchnic nerve-chromaffin cell synapses during nerve activity.

Disturbances that threaten homeostasis elicit activation of the sympathetic nervous system (SNS) and the adrenal medulla. The effectors discharge as a unit to drive global and immediate changes in whole-body physiology. Descending sympathetic information is conveyed to the adrenal medulla via preganglionic splanchnic fibers. These fibers pass into the gland and synapse onto chromaffin cells, which synthesize, store, and secrete catecholamines and vasoactive peptides. While the importance of the sympatho-adrenal branch of the autonomic nervous system has been appreciated for many decades, the mechanisms underlying transmission between presynaptic splanchnic neurons and postsynaptic chromaffin cells have remained obscure. In contrast to chromaffin cells, which have enjoyed sustained attention as a model system for exocytosis, even the Ca2+ sensors that are expressed within splanchnic terminals have not yet been identified. This study shows that a ubiquitous Ca2+-binding protein, synaptotagmin-7 (Syt7), is expressed within the fibers that innervate the adrenal medulla, and that its absence can alter synaptic transmission in the preganglionic terminals of chromaffin cells. The prevailing impact in synapses that lack Syt7 is a decrease in synaptic strength and neuronal short-term plasticity. Evoked excitatory postsynaptic currents (EPSCs) in Syt7 KO preganglionic terminals are smaller in amplitude than in wild-type synapses stimulated in an identical manner. Splanchnic inputs also display robust short-term presynaptic facilitation, which is compromised in the absence of Syt7. These data reveal, for the first time, a role for any synaptotagmin at the splanchnic-chromaffin cell synapse. They also suggest that Syt7 has actions at synaptic terminals that are conserved across central and peripheral branches of the nervous system.

PACAP and acetylcholine cause distinct Ca2+ signals and secretory responses in chromaffin cells.

The adrenomedullary chromaffin cell transduces chemical messages into outputs that regulate end organ function throughout the periphery. At least two important neurotransmitters are released by innervating preganglionic neurons to stimulate exocytosis in the chromaffin cell-acetylcholine (ACh) and pituitary adenylate cyclase activating polypeptide (PACAP). Although PACAP is widely acknowledged as an important secretagogue in this system, the pathway coupling PACAP stimulation to chromaffin cell secretion is poorly understood. The goal of this study is to address this knowledge gap. Here, it is shown that PACAP activates a Gαs-coupled pathway that must signal through phospholipase C ε (PLCε) to drive Ca2+ entry and exocytosis. PACAP stimulation causes a complex pattern of Ca2+ signals in chromaffin cells, leading to a sustained secretory response that is kinetically distinct from the form stimulated by ACh. Exocytosis caused by PACAP is associated with slower release of peptide cargo than exocytosis stimulated by ACh. Importantly, only the secretory response to PACAP, not ACh, is eliminated in cells lacking PLCε expression. The data show that ACh and PACAP, acting through distinct signaling pathways, enable nuanced and variable secretory outputs from chromaffin cells.

Validación de la Escala Breve de Optimismo Interactivo-G en México antes de la COVID-19 / Validation of the Brief Interactive Optimism Scale-G in Mexico before COVID-19 / Validação da Escala Breve de Otimismo Interativo-G no méxico antes do COVID-19

Resumen Los objetivos primarios del presente estudio fueron determinar la validez de constructo, convergente y discriminante de la Escala Breve de Optimismo Interactivo-G (EBOI-G), en participantes de seis estados de México y calcular su consistencia interna. Participaron 3 289 mexicanos, 2 028 hombres y 1 243 mujeres (18 casos no contestaron cuál era su género). Su edad promedio = 30.43 años, DE = 10.52. Se usó el análisis factorial confirmatorio y análisis de regresión múltiple, y se encontraron buenos indicadores promedio de bondad de ajuste (e. g., CFI = .99; RMSEA = .07.). Se evaluó la validez convergente, r (3 289) = .52 (p = < .01; d = mediano), con la Escala de Satisfacción con la Vida. Se estimó la validez discriminante, r (3 289) r = -.19, con la Escala Breve de Disposición a la Ira (p = < .01; d = casi pequeño). El alfa = .70 (3 289); p = < .01; el omega = .76. Se concluye que hay evidencia parcial nacional que apoya el uso de la EBOI-G, debido a la carencia de una medida de este tipo en México, útil cuando menos para propósitos de investigación.

Abstract The primary objectives of this study were determining the construct, convergent, and discriminant validity of the Brief Interactive Optimism Scale-G (BIOS-G) in participants from six states of Mexico and estimating its internal consistency. In this study 3289 Mexicans participated (2028 men and 1243 women). The average age was = 30.43 years and SD = 10.52. Confirmatory factor analysis (CFA) and multiple regression analysis (MRA) were applied. There were appropriate fit indexes (e. g., CFI = .99; RMSEA = .07.). Convergent validity showed an r (3289) = .52 (p = < .01; d = medium), with the Satisfaction with Life Scale (SWLS) and the estimation of discriminant validity was r (3 289) r = -.19 with the Brief Scale for Assessing Anger Proneness (APS-G) (p = < .01; d = almost small), Alpha = .70 (3 289); p = < .01; omega = .76. The conclusion is that there is partial national evidence supporting the use of BIOS-G, because Mexico lacks a measure of this kind, being useful, at least, for research purposes.

Resumo Os objetivos primários do estudo foram determinar a validade convergente e discriminante do construto da Escala Breve de Otimismo Interativo-G (EBOI-G), em participantes de seis estados do México e calcular sua consistência interna. Participaram 3 289 mexicanos, sendo 2 028 homens e 1 243 mulheres. A média de idade foi = 30.43 anos, DP = 10.52. Foram utilizadas análises fatoriais confirmatórias e análises de regressão múltipla. Bons indicadores médios de qualidade de ajuste foram encontrados (por exemplo, CFI = .99; RMSEA = .07.) A validade convergente foi avaliada, r (3 289) = .52 (p = <.01; d = mediana), com a Escala de satisfação com a vida. A validade discriminante, r (3 289) = -.19 foi estimada com a Escala Breve de Disposição à Raiva (p = <.01; d = quase pequeno). O alfa = 0,70 (3 289); p = <0,01; o ômega = 0,76. Conclui-se que há evidências nacionais parciais que apoiam o uso da EBOI-G, devido à falta de uma medida desse tipo no México, sendo útil pelo menos para fins de pesquisa.

Synaptotagmin-7 enhances calcium-sensing of chromaffin cell granules and slows discharge of granule cargos.

Synaptotagmin-7 (Syt-7) is one of two major calcium sensors for exocytosis in adrenal chromaffin cells, the other being synaptotagmin-1 (Syt-1). Despite a broad appreciation for the importance of Syt-7, questions remain as to its localization, function in mediating discharge of dense core granule cargos, and role in triggering release in response to physiological stimulation. These questions were addressed using two distinct experimental preparations-mouse chromaffin cells lacking endogenous Syt-7 (KO cells) and a reconstituted system employing cell-derived granules expressing either Syt-7 or Syt-1. First, using immunofluorescence imaging and subcellular fractionation, it is shown that Syt-7 is widely distributed in organelles, including dense core granules. Total internal reflection fluorescence (TIRF) imaging demonstrates that the kinetics and probability of granule fusion in Syt-7 KO cells stimulated by a native secretagogue, acetylcholine, are markedly lower than in WT cells. When fusion is observed, fluorescent cargo proteins are discharged more rapidly when only Syt-1 is available to facilitate release. To determine the extent to which the aforementioned results are attributable purely to Syt-7, granules expressing only Syt-7 or Syt-1 were triggered to fuse on planar supported bilayers bearing plasma membrane SNARE proteins. Here, as in cells, Syt-7 confers substantially greater calcium sensitivity to granule fusion than Syt-1 and slows the rate at which cargos are released. Overall, this study demonstrates that by virtue of its high affinity for calcium and effects on fusion pore expansion, Syt-7 plays a central role in regulating secretory output from adrenal chromaffin cells.

Tratamiento medicamentoso con clorhexidina como coadyuvante para el manejo de las periocoronaritis: Sancti Spíritus 2007 / Drug treatment with chlorhexidin as adyuvant for the management of pericoronaritis: Sancti Spíritus 2007

Las infecciones odontológicas por pericoronaritis; ocupan el 4to lugar de aparición; como urgencia estomatológica. Las pericoronaritis son; infecciones; agudas que se localizan en los tejidos que recubren la corona del diente parcialmente erupcionado. Suelen aparecer asociadas a la erupción de los terceros molares inferiores y generalmente en la década de los 20 y los 30 años. Objetivo: Describir el tratamiento con clorhexidina al 0,2 por ciento como coadyuvante en el manejo de las pericoronaritis. Material y Método: Se realizó un estudio observacional descriptivo de corte transversal en pacientes con diagnóstico de pericoronaritis atendidos; en la Clínica Estomatológica Docente Provincial Sancti Spíritus, en el período de julio 2006 a enero 2007. La muestra la constituyeron 50 pacientes tributarios de dicho tratamiento que fueron elegidos a través de un muestreo aleatorio. Se tuvieron en cuenta variables como edad, sexo, tipo de origen, estadío clínico de la entidad en estudio y efecto del tratamiento. Resultados: El sexo no marcó diferencia estadística significativa., los pacientes inicialmente acudieron con dolor, infección y toma sistémica, luego de aplicar el tratamiento el estadio clínico predominante se correspondió con buena y muy buena. Donde el tratamiento estuvo evaluado en el mayor porciento de satisfactorio demostrado en el hecho de que la mayoría de los integrantes de la muestra eliminaron los síntomas y signos fundamentales, sin la aparición de ninguna complicación grave. Conclusiones: Se diseñó la forma organizada y secuencial en el tratamiento de las pericoronaritis, utilizando la clorhexidina al 0,2 por ciento como coadyuvante en el tratamiento medicamentoso

Odontological infections from pericoronaritis occupy the fourth place among the leading stomatological emergencies. Pericoronarites are acute infections located in the tissues that recover the crown of the partially erupted tooth. They usually appear associated to the eruption of the third lower molars and generally in the decade of 20 to 30 years.; Objective: To describe the treatment with chlorhexidin 0,2 porcent as; an adyuvant in the management of pericoronarites; Material and Method: A cross-sectional descriptive observational study was made in patients with a diagnosis of pericoronaritis assisted in the Provincial Teaching Stomatological Clinic of Sancti Spíritus, in the period from July of 2006 to January of 2007. The sample was made up of 50 patients who needed this treatment and were chosen through a random sampling. Variables such as age, sex, origin, type, clinical stage of the entity in study and effect of the treatment were taken into account. Results: Sex didn't make a significant statistical difference. Patients initially came with pain, infection and systemic compromise. After applying the treatment, the predominant clinical stage corresponded to good and very good. Therefore, the treatment was evaluated by the highest percent as satisfactory, as demonstrated in the fact that most members of the sample eliminated the fundamental symptoms and signs, without developing any serious complication. Conclusions: The organized and sequential form was designed in the treatment of pericoronarites, using chlorhexidin 0,2 porcent as an adyuvant in the drug treatment

Influence of the availability of commercial infant foods on feeding practices in Jamaica

The decision to cease breast feeding did not have a clearly defined physiological basis in over half of a sample of 150 Jamaican mothers questioned on the feeding regimes of their infants. Neither income nor place of residence, appeared to be related to the decision to cease breast feeding although the source of information on infant feeding did show some association. A variety of commercial infant food products was available; about 40 percent of the mothers used more than one product. Health workers, including midwives, have a potentially important role in bringing about satisfactory weaning (AU)