Efecto de la dibucaína sobre la SERCA del músculo pterigoideo interno / Drug action of dibucaine on the SERCA from medial pterygoid muscle

Objetivo: Determinar el efecto del anestésico local di-bucaína sobre las principales isoformas de la SERCA (calcio ATPasa de retículo sarco-endoplásmico) pre-sentes en músculo pterigoideo interno. Métodos: Se aislaron por centrifugación diferencial membranas de retículo sarcoplásmico de pterigoideo interno de conejo neozelandés macho (n=5). Se separaron las isoformas SERCA1a, 2a y 2b por cromatografía de afinidad. Se determinó in vitro la actividad enzimá-tica en presencia de diferentes concentraciones de dibucaína (0-90 mM) por el método de Fiske y Subba-row, realizando 5 experimentos por duplicado y en paralelo para cada isoforma. Se calculó la media y ES de la CI50 (mM) del anestésico para cada isofor-ma y éstas se compararon por ANOVA de una vía (p<0,05), y prueba Student-Newman-Keuls de com-paraciones múltiples. Resultados: Dibucaína inhibió la actividad enzimática en función de su concentra-ción en las tres isoformas en estudio. Las CI50 fueron: SERCA1a 20,02 ± 0,64 mM, SERCA2a 15,03 ± 0,52 mM y SERCA2b 16,00 ± 0,51 mM y resultaron signi-ficativamente diferentes (F2,27 = 11,08, p<0,001). La prueba post hoc identificó diferencias significativas entre SERCA1a y 2a, 1a y 2b. El efecto inhibitorio re-sultó significativamente mayor sobre las isoformas 2a y 2b, cuya presencia es sustancialmente mayor en músculos masticadores. Conclusión: La dibucaína inhibe a la SERCA de pterigoideo interno a concen-traciones menores que las usadas en clínica médica (29 mM). Es un anestésico local con potencial efecto miotóxico derivado de la inhibición de la SERCA (AU)

Aim: To test the effect of the local anesthetic dibu-caine on the main isoforms of the SERCA (sarco-endosplasmic reticulum calcium-ATPase) in medial pterygoid muscle. Methods: Sarcoplasmic reticulum membranes from male New Zealand rabbits (n=5) were isolated from medial pterygoid muscle by ul-tracentrifugation. The isoforms SERCA1a, 2a and 2b were separated using high affinity chromatography. In vitro enzymatic activity determinations were per-formed in the presence of different dibucaine con-centrations (0-90 mM) using the colorimetric method described by Fiske & Subbarow. Five assays in dupli-cate and run in parallel were performed for each of the isoforms. Mean and SEM of the IC50 (mM) for the effect of the anesthetic on each isoform were calcu-lated and compared by one-way ANOVA (p<0.05), and Student-Newman-Keuls multiple comparisons test. Results: Dibucaine inhibited the enzymatic activity in a concentration-dependent manner for the three studied isoforms. The IC50 values were: SERCA1a 20.02 ± 0.64 mM, SERCA2a 15.03 ± 0.52 mM and SER-CA2b 16.00 ± 0.51 mM. The values were significantly different (F2.27 = 11.08, p<0.001). The post hoc test revealed significant differences between SERCA1a and 2a, 1a and 2b. The inhibitory effect was signifi-cantly higher on 2a and 2b isoforms, whose presence is substantially higher in masticatory muscles. Con-clusion: Dibucaine inhibits SERCA in medial pterygoid muscle at concentrations lower than those used in clinical medicine (29 mM). It is a potentially myotoxic local anesthetic whose toxic effect may derive from SERCA inhibition (AU)

Modelo lineal vs. vectorial: estimación del movimiento mandibular y trabajo mecánico / Linear vs. vector model: estimation of mandible motion and mechanical work

Objetivo: Determinar los momentos de fuerza del haz superficial del masetero (SMH) obtenidos por modelos lineal y vectorial. Métodos: Investigación comparati-va in silico. Se obtuvo la fuerza del SMH con dinamó-metro en 12 pacientes varones adultos jóvenes para calcular el momento de la fuerza y trabajo mecánico a través de simulaciones en JAVA+ con NetBeans8.2. La descomposición de la fuerza fue F.cos α(x,y) y F.cos α(x,y,z) en el modelo lineal y vectorial respectivamen-te. Los momentos de fuerza fueron comparados por ANOVA (p<0,05). Resultados: La fuerza del SMH unila-teral obtenida con dinamómetro (2,5±0,1N) no difirió significativamente del modelo lineal (2,6±0,05N), pero difirió (p<0,001) del vectorial: 1,7, 2,2, 4,2N en x,y,z (general 2,7±0,02N). El momento medio de la fuerza en el modelo vectorial fue -17,9, -15,5, +14,3N.m-2, apuntando a la inclinación mandibular en el eje lateral en dirección caudal anterior, movimiento de inclina-ción en el eje lateral en la dirección cráneo-medial, e inclinación en el eje craneal en la dirección lateral-an-terior. El modelo lineal mostró momento de fuerza de 13,5N.m-2 apuntando un movimiento traslacional en dirección caudal-craneal en el eje anterior-posterior y menor trabajo mecánico del SMH (p=0,012). Con-clusión: Los modelos vectoriales son más eficientes proporcionando datos detallados para estimar los momentos de fuerza y el trabajo mecánico del SMH, y deben incluirse en los algoritmos de cálculo utilizados por dinamómetros (AU)

Objective: to determine the moments of force exerted by the superficial masseter head (SMH) obtained through linear models and vector ones. Methods: comparative in silico research. Data of SMH force obtained with dynamometer in 12 young adult male patients was used to calculate the moment of the force and mechanical work through simulations in JAVA+ performed with NetBeans8.2. Force decomposition was F.cos α(x,y) and F.cos α(x,y,z) in the linear and vector model respectively. The moments of force were compared by ANOVA (p<0.05). Results: Dynamometrical unilateral SMH force (2.5±0.1N) did not differ significantly from the linear model (2.6±0.05N), but differed (p<0.001) from the vector model: 1.7, 2.2, 4.2N on x,y,z (overall 2.7±0.02N). The mean moment of the force in the vector model was -17.9, -15.5, +14.3N.m-2, pointing to mandible's inclination on the lateral axis in anterior-caudal direction, inclination movement on the lateral axis in the cranio-medial direction and inclination on the cranial axis in the lateral-anterior direction. The linear model showed a moment of force of 13.5N.m-2 pointing to translational motion on caudal-cranial direction on the anterior-posterior axis and lower SMH mechanical work (p=0,012). Conclusion: Vector models are more efficient to provide detailed data to estimate the moments of force and mechanical work of SMH and should be included in the calculation algorithms used by dynamometers (AU)

Differential Effect of Articaine on Sarcoendoplasmic Reticulum Calcium Adenosine Triphosphatase of Medial Pterygoid Muscle.

AIMS: To determine the effect of articaine on sarcoendoplasmic reticulum calcium adenosine triphosphatase (SERCA) isoforms of the medial pterygoid muscle. METHODS: Native SERCA from the medial pterygoid muscles of 24 rabbits was isolated by ultracentrifugation, and its isoforms were purified by chromatography and assessed by enzyme-linked immunosorbent assay (ELISA). SERCA activity and calcium transport capability were determined by using colorimetric and radioisotopic methods. The mean ± standard deviation (SD) half maximal inhibitory concentration (IC50) of articaine was determined for each isoform, and these values were compared by using analysis of variance (ANOVA) (P < .05). RESULTS: The native SERCA preparation consisted of 34% SERCA1a, 53% SERCA2a, 10% SERCA2b, and 3% combined SERCA3 and SERCA1b. Articaine caused inhibition of activity and calcium uptake in the native SERCA preparation and in each of the purified isoforms. The IC50 (mM) values for enzymatic activity were: SERCA1a 22.0 ± 2.3 > SERCA2a 16.4 ± 2.4 > SERCA2b 11.3 ± 1.9, and 15.1 ± 2.1 for native SERCA. For calcium transport, IC50 values were: SERCA1a 31.1 ± 3.3 > SERCA2a 24.8 ± 1.8 > SERCA2b 21.5 ± 1.5, and 25.2 ± 3.2 for native SERCA. IC50 values for inhibition of enzymatic activity were significantly different among the purified isoforms, but only the value obtained for SERCA1a was significantly different compared to native SERCA. For inhibition of calcium transport, IC50 values for both SERCA2a and SERCA2b differed significantly compared to SERCA1a, and the value for SERCA1a was significantly different compared to native SERCA. The most articaine-sensitive isoform was SERCA2b, and the native preparation showed sensitivity similar to SERCA2a. CONCLUSION: The differential inhibition of articaine on medial pterygoid SERCA isoforms is evident at concentrations lower than used in current dental practice (125 mM) and accounts for anesthetic myotoxicity. Muscle relaxation likely becomes impaired as a result of increased calcium levels in the myoplasm due to the decreased activity and calcium transport caused by the inhibition of SERCA.

Characterization of third molar morphometric variables

The third molar is a tooth of anatomical, surgical, prosthetic and forensic dental interest. However, there is currently a lack of updated data regarding its morphology. The aim of this study was to determine the morphometric features of third molars and their predictive capability as regards dental arch and side. Two calibrated operators (ƙ = 0.83) determined the cervicalocclusalvestibular (COV), cervicalocclusalpalatal (COP) and occlusalapical (OA) distances, mesiodistal (MD), and vestibularpalatal (VP) diameters, number of roots (R) and number of cusps (C) of 961 cadaveric third molars, both upper (n = 462) and lower (n = 499), using a CONCOR 050 thin mandible caliper (resolution 0.01 mm)...

El tercer molar es una pieza dentaria de interés odontológico anatómico, quirúrgico, endodóntico, protético y forense. Sin embargo, no hay disponibles hoy en día datos morfométricos actualizados del molar. El objetivo del trabajo fue determinar las características morfométricas de terceros molares y establecer el carácter predictivo de las mismas en cuanto a arco dental y lado. Dos operadores calibrados (ƙ = 0.83) determinaron la longitud oclusocervical vestibular (OCV) y palatina (OCP), oclusoapical (OA), diámetro mesiodistal (MD), diámetro vestíbulopalatino (VP), número de raíces (R) y número de cúspides (C), de 961 terceros molares cadavéricos, superiores (n = 462) e inferiores (n = 499), mediante el uso de un calibre de mandíbula fina CONCOR 050 (resolución 0.01 mm)...

Estomatitis herpética y coinfección HIV-1 y P. Jiroveci en una adolescente: informe de un caso / Herpetic stomatitis and HIV-1 and P. Jiroveci co-infection in a female adolescent: report of a case

La infección por el HIV-1 cursa con enfermedades oportunistas asociadas. En referencia a los virus herpes, la asociación más conocida es con el HVS-2. La coinfección HIV-1, HVS-1 y P. jiroveci constituye un cuadro clínico de alta morbilidad y baja frecuencia. Caso clínico: una paciente de 17 años de edad fue derivada a la consulta con sintomatología compatible con gingivoestomatitis herpética recurrente resistente a la terapia con aciclovir p.o. 200 mg cada 5 hs y tratada con amoxicilina-clavulánico p.o. (875 mg-125 mg) cada 12 hs por 20 días. Al ingreso presentaba adenitis cervical, odinofagia, disnea, fiebre (38.2ºC), pulso: 120/min, presión arterial: 120/75 mm Hg, frecuencia respiratoria: 24/min y deterioro generalizado. Se solicitó hacer la serología para el HIV y estudio RX de tórax. La serología para HIV-1 resultó positiva y los valores de CD4+ y carga viral fueron 320/mm3 y 25.000 copias/ml, respetivamente. El estudio RX de tórax reveló neumonía por P. jiroveci que se confirmó posteriormente por fibrobroncoscopía. Se realizó el tratamiento farmacológico de la infección herpética con foscarnet (i.v) 60mg /kg cada 12 hs. durante 3 días, mientras que la neumonía se trató con trimetropima 160 mg y sulfametoxazol p.o. 800 mg cada 6 horas durante 14 días. La remisión de la sintomatología bucal se oservó a los 15 días postratamiento. Conclusión: la población femenina adolescente evidencia una mayor vulnerabilidad biológica y social en relación a la transmisión del HIV. El odontólogo responsable deberá calibrarse en el reconocimiento y diagnóstico precoz de las manifestaciones bucales de dicha infección viral. Ante la presencia de cepas de HVS-1 aresistentes deberá contemplarse la posibilidad de otras infecciones oportunistas simultáneas

Comparison of salivary levels of mucin and amylase and their relation with clinical parameters obtained from patients with aggressive and chronic periodontal disease.

OBJECTIVE: Salivary mucin and amylase levels are increased in patients with chronic periodontitis (CP). Due to the fact that aggressive periodontitis (AgP) not only differs from chronic periodontitis in terms of its clinical manifestation, the aim of this study was to compare salivary mucin and amylase levels and their relation to the clinical parameters of patients with aggressive periodontitis with that of patients with chronic periodontitis. MATERIAL AND METHODS: Eighty subjects were divided into two groups: 20 patients with AgP and their 20 matched controls and 20 patients with CP and their 20 matched controls, based on clinical attachment loss (CAL), probing pocket depth (PPD) and bleeding on probing (BOP). Whole unstimulated saliva was obtained and mucin, amylase and protein were determined by colorimetric methods. Pearson's correlation analysis was used to determine the relationship between salivary mucin, amylase and protein levels and the clinical parameters. RESULTS: Salivary mucin, amylase and protein levels were increased in patients with AgP and CP but there were no differences between them or between control groups. Pearson's correlation analysis, determined in the entire subjects studied, showed a positive and significant correlation of mucin, amylase and proteins with CAL and PPD and a negative correlation with the flow rate. When Pearson's correlation analysis was carried out in each group separately, Fisher's z transformation showed no significant difference between both groups. CONCLUSION: Comparison of the salivary levels of mucin, amylase and protein and their relationship with clinical parameters of AgP patients with that of CP patients revealed no differences between both groups.

Comparison of salivary levels of mucin and amylase and their relation with clinical parameters obtained from patients with aggressive and chronic periodontal disease

Objective Salivary mucin and amylase levels are increased in patients with chronic periodontitis (CP). Due to the fact that aggressive periodontitis (AgP) not only differs from chronic periodontitis in terms of its clinical manifestation, the aim of this study was to compare salivary mucin and amylase levels and their relation to the clinical parameters of patients with aggressive periodontitis with that of patients with chronic periodontitis. Material and Methods Eighty subjects were divided into two groups: 20 patients with AgP and their 20 matched controls and 20 patients with CP and their 20 matched controls, based on clinical attachment loss (CAL), probing pocket depth (PPD) and bleeding on probing (BOP). Whole unstimulated saliva was obtained and mucin, amylase and protein were determined by colorimetric methods. Pearson's correlation analysis was used to determine the relationship between salivary mucin, amylase and protein levels and the clinical parameters. Results Salivary mucin, amylase and protein levels were increased in patients with AgP and CP but there were no differences between them or between control groups. Pearson's correlation analysis, determined in the entire subjects studied, showed a positive and significant correlation of mucin, amylase and proteins with CAL and PPD and a negative correlation with the flow rate. When Pearson's correlation analysis was carried out in each group separately, Fisher's z transformation showed no significant difference between both groups. Conclusion Comparison of the salivary levels of mucin, amylase and protein and their relationship with clinical parameters of AgP patients with that of CP patients revealed no differences between both groups. .

Assessment of physicians´perception of HIV+ patients´oral health

El objetivo de este trabajo fue construir y validar un instrumento capaz de caracterizar las percepciones de los médicos tratantes de los pacientes que viven con VIH/SIDA respecto de la salud bucal. El diseño del instrumento consistió en la identificación de los cuatro dominios que podrían medir elobjeto en estudio y en la elaboración de un cuestionario de 22 items. Los dominios establecidos fueron: conocimientos sobre la salud bucal; experiencia personal con la atención odontológica; conocimientos sobre la salud bucal respecto del VIH/SIDA; prácticas médicas profesionales. Para la validación del instrumento, participaron 50 médicos especialistas en infectología de hospitales públicos de la CABA, quienes completaron anónima y voluntariamente el cuestionario diseñado empleando una escala de frecuencia tipo Likert de 5 categorías. Se evaluó la confiabilidad mediante la aplicación de test y retest a los 30 días; consistencia interna, mediante el coeficiente α de Cronbach; la validez del contenido, se determinó por opinión de expertos; la validez de construcción fue evaluada mediante el método de grupos extremos (prueba deMann Whitney, p < 0.001). El 100 por ciento de los participantes realizó el test y re-test del cuestionario. La edad promedio fue 37.7 ± 0.9 años; 36 por ciento de género femenino y 64 por ciento masculino, con una media de 8.7 ± 0.6 años de ejercicio profesional. El instrumento resultó confiable ya que en el test-retest se obtuvo una correlación de rs = 0.94. El coeficiente α de Cronbach fue de 0.91, demostrando una satisfactoria coherencia intraitems.Las diferencias correspondientes a los resultados de los grupos de médicos ubicados en los extremos resultaron estadísticamente significativas (p < 0.001). Concluimos que el instrumento elaborado para medir la percepción de los médicos tratantes de los pacientes que viven con VIH/SIDA respecto de la salud bucal resultó válido...

Characterization of the sarcoplasmic reticulum Ca-ATPase from rabbit temporalis muscle.

OBJECTIVE: The aim of this work was to isolate the sarcoplasmic reticulum (SR) Ca-ATPase from rabbit temporalis muscle and to determine the optimal conditions for calcium transport and enzymatic activity. DESIGN: SR vesicles were isolated from rabbit temporalis muscle by differential centrifugation, the protein composition analyzed by electrophoresis and compared to fast-twitch muscle membrane suspensions. ELISA was used to determine the sarcoendoplasmic reticulum Ca-ATPase (SERCA) isoform. Ca-ATPase activity was determined by a colorimetric method. Calcium-binding to the Ca-ATPase, calcium uptake, calcium efflux and phosphorylation by P(i) were determined with radioisotopic techniques. RESULTS: Sixty five percent of the total protein concentration of SR membranes suspensions from rabbit temporalis corresponded to SERCA. Of the total SERCA protein, 64% was SERCA 2, 35% was SERCA 1 and less than 1% was SERCA 3. The optimal conditions of the SERCA isolated from rabbit temporalis muscle were: pH 7.2, 5 µM Ca(2+), 100 µM EGTA, 90 µM Mg(2+), 3mM ATP and 100mM KCl and did not differ from fast-twitch skeletal muscle. The temporalis maximal calcium uptake and Ca-ATPase activity were lower but the sensitivity to the specific Ca-ATPase inhibitor thapsigargin was higher. Calcium-binding to the enzyme and calcium efflux were similar while the phosphorylation of the enzyme by P(i) was lower. CONCLUSION: The lower enzymatic activity and calcium transport capability of the Ca-ATPase isolated from rabbit temporalis, and the higher sensitivity to inhibitory drugs are consistent with the presence of a substantial proportion of SERCA 2, which can be expected in other rabbit masticatory muscles.