Safety profile and SARS-CoV-2 breakthrough infections among HCWs receiving anti-SARS-CoV-2 and influenza vaccines simultaneously: an Italian observational study.

In October/December 2021, World Health Organization and other international agencies recommended the offer of the third dose of anti-SARS-CoV-2 vaccine. In this period, the routine offer of seasonal influenza vaccination was also guaranteed and simultaneous administration of the two vaccines was encouraged. This study aims to evaluate the safety profile and to estimate the incidence of SARS-CoV-2 breakthrough infections in subjects receiving the anti-SARS-CoV-2 and influenza vaccines simultaneously. The study population was represented by healthcare workers (HCWs) of Bari Policlinico General Hospital who received the influenza (Flucelvax Tetra®) and/or anti-SARS-CoV-2 vaccination (BNT162b2 mRNA COVID-19 vaccine, Comirnaty®) either in coadministration or separately in October 2021. Reports of adverse events following immunization (AEFIs) were investigated to study the safety of both vaccines in coadministration and in separate-instance administration. Post-vaccination SARS-CoV-2 breakthrough infection was also studied. 942 HCWs accepted to join our study. 610/942 received both vaccines simultaneously. 25.26 % subjects (238/942) were only vaccinated against SARS-CoV-2, while the remaining 94 HCWs received the influenza vaccination first and subsequently received the anti-SARS-CoV2 booster dose. 717 HCWs reported AEFIs (Reporting Rate 76.1 per 100 subjects). Simultaneous administration of the two vaccines was not related with an increase of the rate of AEFIs compared to the single administration of SARS-CoV-2 vaccine, but the AEFIs' rate was lower among subjects who received only influenza vaccine. Post-vaccination SARS-CoV-2 infections were notified for 41.5 % of enrolled subjects (391/942). Incidence of breakthrough infection and symptomatic disease was not significantly different between the simultaneous administration group and other subjects. Our data suggests that simultaneous administration of a quadrivalent influenza vaccine and an mRNA anti-SARS-CoV-2 vaccine neither affected the safety of said products nor was associated with a higher risk of SARS-CoV-2 breakthrough infection.

Frailty in Chile: Development of a Frailty Index Score Using the Chilean National Health Survey 2016-2017.

BACKGROUND: The Frailty Index (FI) is used to quantify and summarize vulnerability status in people. In Chile, no development and assessment of a FI have been explored. OBJECTIVE: To develop and evaluate a FI using representative data from Chilean adults aged 40 years and older stratified by sex. DESIGN: Cross-sectional study. SETTING: National representative data from the Chilean National Health Survey 2016-2017 (CNHS 2016-2017). PARTICIPANTS: 3,036 participants older than 40 years with complete data for all variables. MEASUREMENTS: A 49-item FI was developed and evaluated. This FI included deficits from comorbidities, functional limitations, mental health status, physical activity, anthropometry, medications, and falls. A score between 0 and 1 was calculated for each person. Descriptive statistics and linear regression models were employed to evaluate the FI's performance in the population. Comparative analyses were carried out to evaluate the FI score by age (1<60 and ≥ 60 years). RESULTS: The mean FI score was 0.15 (SD:0.09), with a 99% upper limit of 0.46. Scores were greater in women than men (0.17 [SD:0.09]) vs. 0.12 [0.08]); in people older than 80 years (0.22 [0.11]), and in people with ≤8 years of education (0.18 [0.10]) compared with those with >12 years (0.12 [0.08]). The average age-related increase in the FI was 2.3%. When a cut-off point ≥ 0.25 was applied, the prevalence of frail individuals was 11.8% (95% CI: 10.0 to 13.8) in the general population. The prevalence was higher in women 15.9% [95% CI: 13.3 to 18.9] than men 7.4% [95% CI: 5.3 to 10.1]. In a comparative analysis by age, higher FI mean scores and prevalence of frail were observed in people ≥ 60 than younger than 60. CONCLUSIONS: The mean FI score and frailty prevalence were higher in women than men, in people with fewer years of formal education, and incremented markedly with age. This FI can be used for early detection of frailty status focusing on women and middle-aged people as a strategy to delay or prevent frailty-related consequences.

Association between Poor Oral Health and Frailty in Middle-Aged and Older Individuals: A Cross-Sectional National Study.

OBJECTIVES: Older adults with poor oral health may be at higher risk of being pre-frail or frail. However, very few studies have examined this association in Latin American countries and middle-aged individuals. Therefore, we aimed to investigate the association between oral health and frailty status among Chilean adults ≥40 years. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: We included 3,036 participants ≥40 years from the Chilean National Health Survey 2016-2017. METHODS: Frailty status was assessed with a 49-item frailty index, while the number of teeth, self-reported oral health, tooth decay, use of prostheses, and oral pain were the oral health conditions included. To assess the association between oral health conditions and frailty, we used multinomial logistic regression models status adjusted for sociodemographic and lifestyle variables. RESULTS: Overall, 40.6% and 11.8% of individuals were classified as pre-frail and frail, respectively. After adjusting for confounders, individuals with ≤20 teeth had a higher likelihood of being frail (odds ratio (OR): 1.94 [95% CI: 1.18-3.20]) than people with >20 teeth. Moreover, people with bad or very bad oral health, as well as oral pain, had a higher likelihood of being pre-frail (OR: 2.04 [95% CI: 1.40-2.97] and OR: 2.92 [95% CI: 1.58-5.39], respectively). Middle-aged individuals with fewer teeth and poor self-reported oral health had a higher likelihood of being pre-frail and frail than people ≥60. CONCLUSIONS AND IMPLICATIONS: Individuals with poor global oral health were more likely to be pre-frail or frail. This association seems to be stronger in people <60 years old. Our results are consistent with previously published reports.

[Comparative analysis of three models of reverse shoulder prosthesis based on the new angles of distalization and lateralization]. / Análisis comparativo de tres modelos de prótesis reversa de hombro basados en los nuevos ángulos de distalización y lateralización.

PURPOSE: Compare functional and radiological outcomes of three different designs of reverse shoulder arthroplasty according to distalization and lateralization shoulder angle, in heterogenic diagnostics (fracture, cuff arthropathy, fracture sequela and osteoarthritis). MATERIAL AND METHODS: Prospective cohort of 33 patients of reverse shoulder arthroplasty (RSA) between December 2014 and July 2017 with a minimum one year of follow-up. We defined three groups, G: 10 patients with Grammont (155o, Medialized Glena), B: 9 patients with Bio-RSA (155º, lateralized bone glena) and A: 14 patients with Arrow (135o, lateralized metallic glena). We analyze demographic, clinical, functional and radiological outcomes (lateralization shoulder angle (LSA) and distalization shoulder angle (DSA)). For the statistical analysis, ANOVA, T-tests and linear regression tests were used, with a statistical significance of 5%. RESULTS: The LSA was significantly higher in group A (98o A, 79o G, 80o B) (p < 0.05). In DSA, group B was significantly higher than A (52o B, 39o A) (p < 0.05) and not significant to G (48o G) (p = 0.06). There was no correlation of LSA and DSA with external rotation (p = 0.51) and active elevation (p = 0.41), respectively. There was no significant clinical (anterior elevation, external rotation, internal rotation) and functional outcomes (adjusted Constant score and subjective shoulder evaluation) differences between the different RSA models (p > 0.05). CONCLUSIONS: The LSA was higher in the Arrow and the DSA was higher in Bio-RSA. We did not find Clinical - Radiological correlation in this heterogeneous series of patients.

OBJETIVO: Comparar resultados funcionales e imagenológicos de tres modelos protésicos según el índice de lateralización y distalización. En un grupo heterogéneo de diagnósticos (fractura, artropatía de manguito, secuela de fractura y artrosis glenohumeral). MATERIAL Y MÉTODOS: Cohorte prospectiva de 33 pacientes sometidos a prótesis reversa de hombro entre Diciembre 2014 y Julio 2017 con un seguimiento mínimo de un año. Se definieron tres grupos, G: 10 pacientes con Grammont clásico (155o, Glena medializada); B: nueve pacientes con Bio-RSA (155o, glena lateralizada ósea); y A: 14 con Arrow (135o, glena lateralizada metálica). Las variables fueron: datos demográficos, clínicos, funcionales y radiológicos (ángulo de lateralización y distalización). Para el análisis estadístico se utilizaron pruebas de ANOVA, T-test y regresión lineal, con una significancia estadística de 5%. RESULTADOS: El ángulo de lateralización del hombro (LSA) fue significativamente mayor en el grupo A (98o A, 79o G, 80o B) (p < 0.05). El ángulo de distalización del hombro (DSA) del grupo B fue significativamente superior al A (52o B, 39o A) (p < 0.05) y no significativamente superior al G (48o G) (p = 0.06). No se demostró una correlación entre el LSA y DSA con la rotación externa (p = 0.51) y elevación activa (p = 0.41), respectivamente. En índices clínicos (elevación anterior, rotación externa, rotación interna) y funcionales (índice Constant ajustado y evaluación subjetiva de hombro) no encontramos diferencias significativas entre los distintos modelos protésicos (p > 0.05). CONCLUSIONES: El ángulo de lateralización fue mayor en el modelo Arrow y distalización en el modelo Bio-RSA. No encontramos correlación clínica-radiológica en esta serie heterogénea de pacientes.

Análisis comparativo de tres modelos de prótesis reversa de hombro basados en los nuevos ángulos de distalización y lateralización / Comparative analysis of three models of reverse shoulder prosthesis based on the new angles of distalization and lateralization

Resumen: Objetivo: Comparar resultados funcionales e imagenológicos de tres modelos protésicos según el índice de lateralización y distalización. En un grupo heterogéneo de diagnósticos (fractura, artropatía de manguito, secuela de fractura y artrosis glenohumeral). Material y métodos: Cohorte prospectiva de 33 pacientes sometidos a prótesis reversa de hombro entre Diciembre 2014 y Julio 2017 con un seguimiento mínimo de un año. Se definieron tres grupos, G: 10 pacientes con Grammont clásico (155o, Glena medializada); B: nueve pacientes con Bio-RSA (155o, glena lateralizada ósea); y A: 14 con Arrow (135o, glena lateralizada metálica). Las variables fueron: datos demográficos, clínicos, funcionales y radiológicos (ángulo de lateralización y distalización). Para el análisis estadístico se utilizaron pruebas de ANOVA, T-test y regresión lineal, con una significancia estadística de 5%. Resultados: El ángulo de lateralización del hombro (LSA) fue significativamente mayor en el grupo A (98o A, 79o G, 80o B) (p < 0.05). El ángulo de distalización del hombro (DSA) del grupo B fue significativamente superior al A (52o B, 39o A) (p < 0.05) y no significativamente superior al G (48o G) (p = 0.06). No se demostró una correlación entre el LSA y DSA con la rotación externa (p = 0.51) y elevación activa (p = 0.41), respectivamente. En índices clínicos (elevación anterior, rotación externa, rotación interna) y funcionales (índice Constant ajustado y evaluación subjetiva de hombro) no encontramos diferencias significativas entre los distintos modelos protésicos (p > 0.05). Conclusiones: El ángulo de lateralización fue mayor en el modelo Arrow y distalización en el modelo Bio-RSA. No encontramos correlación clínica-radiológica en esta serie heterogénea de pacientes.

Abstract: Purpose: Compare functional and radiological outcomes of three different designs of reverse shoulder arthroplasty according to distalization and lateralization shoulder angle, in heterogenic diagnostics (fracture, cuff arthropathy, fracture sequela and osteoarthritis). Material and methods: Prospective cohort of 33 patients of reverse shoulder arthroplasty (RSA) between December 2014 and July 2017 with a minimum one year of follow-up. We defined three groups, G: 10 patients with Grammont (155o, Medialized Glena), B: 9 patients with Bio-RSA (155º, lateralized bone glena) and A: 14 patients with Arrow (135o, lateralized metallic glena). We analyze demographic, clinical, functional and radiological outcomes (lateralization shoulder angle (LSA) and distalization shoulder angle (DSA)). For the statistical analysis, ANOVA, T-tests and linear regression tests were used, with a statistical significance of 5%. Results: The LSA was significantly higher in group A (98o A, 79o G, 80o B) (p < 0.05). In DSA, group B was significantly higher than A (52o B, 39o A) (p < 0.05) and not significant to G (48o G) (p = 0.06). There was no correlation of LSA and DSA with external rotation (p = 0.51) and active elevation (p = 0.41), respectively. There was no significant clinical (anterior elevation, external rotation, internal rotation) and functional outcomes (adjusted Constant score and subjective shoulder evaluation) differences between the different RSA models (p > 0.05). Conclusions: The LSA was higher in the Arrow and the DSA was higher in Bio-RSA. We did not find Clinical - Radiological correlation in this heterogeneous series of patients.

Increasing resolution of airborne pollen forecasting at a discrete sampled area in the southwest Mediterranean Basin.

Daily fluctuations of the airborne pollen concentrations produce variations on symptomatology in allergic population. Such fluctuations are influenced by local vegetal coverage, flowering phenology, geography and climatology. Since 1991, airborne pollen of Malaga province (southern Spain) has been monitored in 7 different locations. Malaga station has been kept operational uninterruptedly throughout the studied period, while the rest of the stations only worked in periods of 2-4 years. Weekly, its pollen information is updated online to inform the population in order to prevent allergic diseases. Increasing the spatial resolution of pollen information would be very useful for allergic population living at unsampled locations. Due to the impossibility of keeping operational a high number of pollen stations covering the whole province of Malaga, the aim of this study is to create spatial models to extrapolate and forecast the pollen concentrations to Malaga province by using the concentrations registered at the capital as unique input. To do so, the relationships obtained between the airborne pollen concentrations detected at Malaga city and those detected at the other stations have been used to elaborate models for the main pollen types registered at the province. These models were spatially interpolated all over the province by using co-kriging techniques and the Compensated Thermicity Index as covariable. As result of this work, pollen distribution of the 8 most prevalent taxa has been depicted all over the whole Malaga province and an allergy alert system has been set up to extrapolate pollen information from Malaga to the whole province.

Ambient conditions of elevated temperature and CO2 levels are detrimental to the probabilities of transmission by insects of a Potato virus Y isolate and to its simulated prevalence in the environment.

Conditions of elevated temperature and CO2 levels [30 °C and 970 parts-per-million (ppm), respectively] reduced the systemic titers of a potato virus Y (PVY) isolate in Nicotiana benthamiana plants, relative to standard conditions (25 °C, ~405 ppm CO2). Under controlled conditions we studied how these growing environments affected the transmission of infection by aphids. Probabilities of transmission of infection by insects that fed on infected donor plants kept at either standard conditions, or at 30 °C and 970 ppm CO2 were both determined and found to positively correlate with titers in donor leaves, independently of the ambient conditions in which recipient plantlets would grow. With these data, viral prevalence was simulated under conditions of elevated temperature and CO2 levels and found that for it to remain comparable to that simulated under standard conditions, insect arrivals to recipient plants in the former scenario would have to increase several-fold in their frequency.

Manejo de la vía aérea de pacientes con obstrucción severa de la luz glótica. Experiencia con el estilete óptico de Bonfils / Airway management of patients with severe obstruction of the glottic opening. Experience with the Bonfils optical stylet

No disponible

Desmielinización osmótica. Descripción de un caso de mielinolisis central extrapontina / Osmotic demyelination. A description of a case of central pontine myelinolysis

No disponible

Chondrogenic potential of subpopulations of cells expressing mesenchymal stem cell markers derived from human synovial membranes.

In this study we analyzed the chondrogenic potential of subpopulations of mesenchymal stem cells (MSCs) derived from human synovial membranes enriched for CD73, CD106, and CD271 markers. Subpopulations of human synovial membrane MSCs enriched for CD73, CD106, and CD271 markers were isolated using a cytometry sorter and characterized by flow cytometry for MSC markers. The expression of Sox9, Nanog, and Runx2 genes by these cells was measured by reverse transcriptase-polymerase chain reaction. The chondrogenesis of each subpopulation was assessed by culturing the cells in a defined medium to produce spontaneous spheroid formation and differentiation towards chondrocyte-like cells. The examination of the spheroids by histological and immunohistochemical analyses for collagen type II (COL2), aggrecan, collagen type I (COL1), metalloprotease 13 (MMP13), and collagen type X (COLX) levels were performed to assess their chondrogenesis capacity. The adipogenesis and osteogenesis potential of each subpopulation was determined using commercial media; the resulting cells were stained with oil red O or red alizarin to test the degree of differentiation. The subpopulations had different profiles of cells positive for the MSC markers CD44, CD69, CD73, CD90, and CD105 and showed different expression levels of the genes Sox9, Nanog, and Runx2 involved in chondrogenesis, undifferentiation, and osteoblastogenesis, respectively. Immunohistochemical analysis demonstrated that COL1, COL2, COLX, MMP13, and aggrecan were expressed in the spheroids as soon as 14 days of culture. The CD271(+) subpopulation expressed the highest levels of COL2 staining compared to the other subpopulations. CD105 and Runx2 were shown by immunohistochemistry and genetic analysis to have significantly higher expression CD271(+) subpopulation than the other subpopulations. Spheroids formed from CD271-enriched and CD73-enriched MSCs from normal human synovial membranes mimic the native cartilage extracellular matrix more closely than CD106(+) MSCs and are possible candidates for use in cartilage tissue engineering. Both cell types have potential for promoting the differentiation of MSCs into chondrocytes, presenting new possibilities for achieving intrinsic cartilage repair.

Distribution of killer cell immunoglobulin-like receptor genes in the mestizo population from Venezuela.

This study represents the first report on the distribution of KIR genes in 205 unrelated healthy mestizo Venezuelan individuals. Genotyping analysis showed that all KIR genes are present in this population. Frequency of inhibitory killer cell immunoglobulin-like receptors (KIRs) exceeded 0.69, except for KIR2DL2 (0.29) and 2DL5 (0.37). Activating KIRs showed low frequencies (0.11-0.29), except for KIR2DS4 (0.68). Forty-five different KIR genotypes were identified, with a predominance of three genotypes found in 50.7% of the population of which 25.9% were individuals homozygous for haplotype A. The frequencies of KIR genes reflect the ethnic admixture existing in the mestizo Venezuelan population.

Adaptation of green microalgae to the herbicides simazine and diquat as result of pre-selective mutations.

Aquatic ecosystems located close to agricultural areas are increasingly polluted by herbicides. We evaluated the capacity for adaptation of green microalgae to lethal concentrations of the herbicide simazine in one strain of Dictyosphaerium chlorelloides and two strains of Scenedesmus intermedius, as well as adaptation to the herbicide diquat in one of the strains of S. intermedius. A Luria-Delbrück fluctuation analysis was carried out in order to distinguish between resistant cells arising from physiological adaptation (acclimatization) or post-adaptive mutation (both events occurring after the exposure to the herbicides), and adaptation due to mutations before the exposure to the herbicides. Simazine-resistant cells arose by rare spontaneous mutations before the exposure to simazine, with a rate of 3.0 x 10(-6) mutants per cell per generation in both strains of S. intermedius, and of 9.2 x 10(-6) mutants per cell per generation in D. chlorelloides. Diquat-resistant cells in S. intermedius arose by pre-selective mutations with a rate of 17.9 x 10(-6) per cell per generation. Rare, pre-selective mutations may allow the survival of green microalgae in simazine- or diquat-polluted waters, via herbicide-resistant selection. Therefore, human-synthesized pollutants, such as the herbicides simazine and diquat, could cause the emergence of evolutionary novelties in aquatic environments.

La automedida de la presión arterial / Self-measurement of blood pressure

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ECG characterization of paroxysmal atrial fibrillation: parameter extraction and automatic diagnosis algorithm.

Paroxysmal atrial fibrillation (PAF) is one of the most common heart arrhythmias. It is very difficult to detect unless an explicit Atrial Fibrillation episode occurs during the exploration. The present paper describes a number of low level parameters extracted from ECG traces where no Atrial Fibrillation process is present. The ability of this parameter set to characterize PAF patients is studied and discussed. Based on these parameters a modular automatic classification algorithm for PAF diagnosis is developed and evaluated.

Automatic Paroxysmal Atrial Fibrillation Based on not Fibrillating ECGs.

OBJECTIVES: The objective of the paper is to describe an automatic algorithm for Paroxysmal Atrial Fibrillation (PAF) Detection, based on parameters extracted from ECG traces with no atrial fibrillation episode. The modular automatic classification algorithm for PAF diagnosis is developed and evaluated with different parameter configurations. METHODS: The database used in this study was provided by Physiobank for The Computers in Cardiology Challenge 2001. Each ECG file in this database was translated into a 48 parameter vector. The modular classification algorithm used for PAF diagnosis was based on the nearest K-neighbours. Several configuration options were evaluated to optimize the classification performance. RESULTS: Different configurations of the proposed modular classification algorithm were tested. The uni-parametric approach achieved a top classification rate value of 76%. A multi-parametric approach was configured using the 5 parameters with highest discrimination power, and a top classification rate of 80% was achieved; different functions to typify the parameters were tested. Finally, two automatic parametric scanning strategies, Forward and Backward methods, were adopted. The results obtained with these approaches achieved a top classification rate of 92%. CONCLUSIONS: A modular classification algorithm based on the nearest K-neighbours was designed. The classification performance of the algorithm was evaluated using different parameter configurations, typification functions and number of K-neighbors. The automatic parametric scanning techniques achieved much better results than previously tested configurations.

Menopausia e hipertensión arterial / Menopause and arterial hypertension

Los cambios de la tensión arterial (TA) relacionados con la menopausia son difíciles de evaluar porque coinciden con el envejecimiento, aumento de peso, cambios en el estilo de vida y presencia de otros factores de riesgo cardiovascular. Pero, aunque aún en discusión, existen evidencias de que la deficiencia estrogénica puede inducir disfunción endotelial e hiperactividad simpática y potenciar el aumento de la presión sistólica relacionado con la edad. El tratamiento hormonal sustitutivo (THS) no aumenta la incidencia de hipertensión arterial (HTA) ni agrava la preexistente, en cambio, sí se evidencia aumento significativo de colesterol ligado a lipoproteínas de baja densidad (LDL), disminución de colesterol ligado a lipoproteínas de alta densidad (HDL), aumento de triglicéridos y disminución del fibrinógeno. En cualquier caso, no existe contraindicación para la utilización del THS en la mujer postmenopáusica con HTA. Ahora bien, es aconsejable, como afirma el Joint National Committee (JNC-VI), que a estas mujeres se les controle periódicamente la TA.Hoy por hoy, y mientras no se disponga de los resultados definitivos de estudios en marcha, el THS no está indicado para la prevención de cardiopatía isquémica en la mujer sana. Cuando se valore la decisión de instaurar o no THS a una mujer postmenopáusica, la prevención de la patología cardiovascular no ha de estar entre sus indicaciones. Las guías internacionales no diferencian en lo que respecta al tratamiento de la HTA entre sexos o estado hormonal, luego las recomendaciones son las mismas que en cualquier hipertenso. Se debe hacer especial hincapié en las medidas higiénico-dietéticas y en la restricción de sodio por la alta prevalencia de sal-sensibilidad, en la pérdida de peso en caso de coexistir obesidad, recomendar la utilización de los suplementos orales de calcio, ya que pueden tener un efecto aditivo con el tratamiento farmacológico antihipertensivo y ayudan a prevenir la osteoporosis. El ejercicio físico aeróbico colaborará a reducir el riesgo cardiovascular y a evitar la pérdida de calcio del hueso. Cualquier antihipertensivo podría ser utilizado en la mujer con THS, ya que no existen datos de que el tratamiento hormonal afecte a la eficacia o seguridad de estos medicamentos (AU)

Differential regulation of growth plate chondrocytes by 1alpha,25-(OH)2D3 and 24R,25-(OH)2D3 involves cell-maturation-specific membrane-receptor-activated phospholipid metabolism.

This review discusses the regulation of growth plate chondrocytes by vitamin D(3). Over the past ten years, our understanding of how two vitamin D metabolites, 1alpha,25-(OH)(2)D(3) and 24R,25-(OH)(2)D(3), exert their effects on endochondral ossification has undergone considerable advances through the use of cell biology and signal transduction methodologies. These studies have shown that each metabolite affects a primary target cell within the endochondral developmental lineage. 1alpha,25-(OH)(2)D(3) affects primarily growth zone cells, and 24R,25-(OH)(2)D(3) affects primarily resting zone cells. In addition, 24R,25-(OH)(2)D(3) initiates a differentiation cascade that results in down-regulation of responsiveness to 24R,25-(OH)(2)D(3) and up-regulation of responsiveness to 1alpha,25-(OH)(2)D(3). 1alpha,25-(OH)(2)D(3) regulates growth zone chondrocytes both through the nuclear vitamin D receptor, and through a membrane-associated receptor that mediates its effects via a protein kinase C (PKC) signal transduction pathway. PKCalpha is increased via a phosphatidylinositol-specific phospholipase C (PLC)-dependent mechanism, as well as through the stimulation of phospholipase A(2) (PLA(2)) activity. Arachidonic acid and its downstream metabolite prostaglandin E(2) (PGE(2)) also modulate cell response to 1alpha,25-(OH)(2)D(3). In contrast, 24R,25-(OH)(2)D(3) exerts its effects on resting zone cells through a separate, membrane-associated receptor that also involves PKC pathways. PKCalpha is increased via a phospholipase D (PLD)-mediated mechanism, as well as through inhibition of the PLA(2) pathway. The target-cell-specific effects of each metabolite are also seen in the regulation of matrix vesicles by vitamin D(3). However, the PKC isoform involved is PKCzeta, and its activity is inhibited, providing a mechanism for differential autocrine regulation of the cell and events in the matrix by these two vitamin D(3) metabolites.

¿Participa la histamia mastocitaria en el reflejo periférico que modula la actividad simpática en la rata? / It participates the histamine mast cell in the outlying reflection that it modulates the nice activity in the rat?

Estudios previos realizados por Campos y colaboradores han demostrado la presencia de un reflejo periférico que modula inhibitoriamente la actividad simpática en el conducto deferente de la rata. Una modulación inhibitoria similar fue encontrada en el corazón del perro. En este reflejo periférico de asa corta parece estar involucrada una interacción entre neuronas noradrenérgicas y neuronas que contienen histamina, en el cual la histamina neural parece estar modulando la actividad simpática y la presión arterial de una manera inhibitoria. En este sentido, intervenciones quirúrgicas de la vía neuronal que contiene histamina, la cual es adyacente a los niveles simpáticos del conducto deferente de la rata, causan una facilitación local de la actividad simpática. Además, Campos y colaboradores demostraron también un incremento de la actividad de la L-histidina descarboxilasa, marcador de la neurona que contiene histamina, por estimulación de la vía simpática, e inhibición de la enzima causó una facilitación de la actividad simpática e hipertensión arterial en la rata, sugiriendo la existencia de un mecanismo generalizado modulador de la actividad simpática. Condiciones estresantes que aumentan la actividad simpática incrementan los niveles sanguíneos de histamina en la rata y en humanos, por lo que se piensa que concomitantemente con la descarga simpática hay una liberación de histamina neuronal periférica como fenómeno reflejo compensador. Teniendo en cuenta estos hallazgos, en este trabajo se procedió explorar si hay participación de la histamina mastocitaria en el reflejo periférico de autorregulación de la actividad simpática. Para ello, ratas machos Srague-dawley recibieron 0.75 mg/kg, i.p. del compuesto 48/80, diariamente por 12 días; tratamiento que produce una marcada desgranulación mastocitaria. Se determinó la presión arterial media y la frecuencia cardíaca usando un plestimógrafo de cola, encontrándose que los parámetros cardiovasculares no cambiaron ni en el curso ni al final de la desgranulación con el compuesto 48/80. De estos estudios se desprende que la histamina mastocitaria tiene un papel secundario en la regulación funcional de la actividad simpática