Reactivity and selectivity of the reaction of O,O-diethyl 2,4-dinitrophenyl phosphate and thionophosphate with thiols of low molecular weight.

A reactivity and selectivity study of O,O-diethyl 2,4-dinitrophenyl phosphate () and O,O-diethyl 2,4-dinitrophenyl thionophosphate () with a series of thiols of low molecular weight: N-acetyl cysteine (NAC), l-cysteine (Cys), homocysteine (Hcys), glutathione (GSH), and d-penicillamine (Pen) was conducted. Results show that (i) these nucleophiles only attack at the aromatic moiety of both triester derivatives, (ii) a kinetic control product by sulfhydryl attack of thiols was observed in the reactions of both triesters with Cys and Hcys, followed by an intramolecular amine attack leading to a thermodynamic control product. The kinetic study leads to the proposal of Meisenheimer complex formation and then proton transfer to the reaction media as the mechanism of these reactions.

The Male Warrior Hypothesis: Testosterone-related Cooperation and Aggression in the Context of Intergroup Conflict.

The Male Warrior Hypothesis (MWH) establishes that men's psychology has been shaped by inter-group competition to acquire and protect reproductive resources. In this context, sex-specific selective pressures would have favored cooperation with the members of one's group in combination with hostility towards outsiders. We investigate the role of developmental testosterone, as measured indirectly through static markers of prenatal testosterone (2D:4D digit ratio) and pubertal testosterone (body musculature and facial masculinity), on both cooperation and aggressive behavior in the context of intergroup conflict among men. Supporting the MWH, our results show that the intergroup conflict scenario promotes cooperation within group members and aggression toward outgroup members. Regarding the hormonal underpinnings of this phenomenon, we find that body musculature is positively associated with aggression and cooperation, but only for cooperation when context (inter-group competition) is taken into account. Finally, we did not find evidence that the formidability of the group affected individual rates of aggression or cooperation, controlling for individual characteristics.

Poly-beta-hydroxyalkanoate exert a protective effect against carbon starvation and frozen conditions in Sphingopyxis chilensis.

Several bacterial species have developed physiological response to avoid the cellular damage when are exposed to carbon starvation or frozen stress. For example survival to inanition has been related to endogenous substrates consumptions. The aim of this study was to evaluate if poly-beta-hydroxylkanoates (PHA) consumption enable Sphingopyxis chilensis S37 to survive under carbon starvation or frozen condition. Bacterial cells were grown in R(2)A broth for 48 h, and suspended in mineral saline solutions, without carbon source. The cellular suspension was incubated for 48 or 120 h at 30 degrees C, followed by a frozen period of 48 h at -20 degrees C, and viable bacterial cells were evaluated by the microdrop method. The proportions of cells with PHA were also determined by flow cytometry using Nile Red dye. The results indicate that S. chilensis were able to survive under carbon starvation and frozen conditions. Simultaneously, a decrease in the number of cells containing PHA, and a decrease in the biovolume of the cells (c.a 2.5 times) were also observed under these conditions. The results suggest that consumptions of PHA contributed to the surviving of S. chilensis under frozen stress.

Intravitreal bevacizumab as single drug therapy for retinopathy of prematurity in 12 patients.

Ophthalmological outcomes in a series of children with retinopathy of prematurity (ROP) in the threshold stage treated with intravitreal bevacizumab are reported. Twelve very low birth weight (VLBW) preterm infants who were administered intravitreal bevacizumab as monotherapy for retinopathy of prematurity in the threshold stage and in whom standard laser photocoagulation therapy was contraindicated were evaluated. Ophthalmological examinations were carried out and response to treatment, second interventions, and complications were evaluated. The gestational age of these patients was 26.3 ± 1.8 weeks and their birth weight was 845 ± 153 g. A good response was observed in eight cases, while four patients required to be reintervened with laser photocoagulation. No immediate complications were detected and there were no deaths.

Kinesiología respiratoria en pacientes asmáticos en edad escolar / Respiratory physiotherapy in asthmatic school-age patients

The role of respiratory physiotherapy in the asthmatic school-age patient is based on three pillars: evaluative, therapeutic and educational, which have gradually been incorporated and developed. Respiratory physiotherapy has advanced significantly, incorporating cardiorespiratory function tests into its diagnostic and follow-up services, allowing the execution of these tests at the primary level of healthcare. Manual and instrumental respiratory physiotherapy techniques increase the level of control of asthmatic patients. The evidence found in literature invites us to innovate the methodology we use at educational interventions in children and adolescents, with the inclusion of new technologies to motivate and generate meaningful learning in patients as well as in their parents/caregivers, thus improving adherence to treatment and achieving the desired control of the disease

El rol de la kinesiología respiratoria en el paciente asmático en etapa escolar, se basa en tres pilares: evaluativo, terapéutico y educativo, los cuales se han ido paulatinamente incorporando y desarrollando con el paso del tiempo. La kinesiología respiratoria ha avanzado significativamente, incorporando pruebas de función cardiorrespiratoria a su arsenal de prestaciones diagnósticas y de seguimiento, permitiendo la ejecución de éstas en el nivel primario de atención. Mediante la utilización de técnicas manuales e instrumentales, permite potenciar el nivel de control de los pacientes asmáticos. La literatura nos invita a innovar en la metodología a utilizar para realizar una intervención educativa efectiva en niños y adolescentes, incluyendo las nuevas tecnologías disponibles para motivar y generar un aprendizaje significativo en el paciente como en los padres/cuidadores, mejorando así la adherencia al tratamiento y por ende logrando el anhelado control de la enfermedad

Bevacizumab intravítreo como monoterapia de la retinopatía del prematuro en 12 pacientes / Intravitreal bevacizumab as single drug therapy for retinopathy of prematurity in 12 patients

Comunicamos los resultados oftalmológicos en una serie de niños tratados con bevacizumab intravítreo con retinopatía del prematuro (RDP) en etapa umbral. Se evaluaron doce recién nacidos pretérmino de muy bajo peso (RNMBP) que recibieron bevacizumab intravítreo como monoterapia en el tratamiento de la retinopatía del prematuro en etapa umbral y que presentaban contraindicación para la terapia estándar con fotocoagulación con láser. Se realizaron controles oftalmológicos y se evaluó la respuesta al tratamiento, reintervenciones y complicaciones. La edad gestacional de estos pacientes fue 26,3 ± 1,8 semanas y el peso de nacimiento de 845 ± 153 g. Hubo buena respuesta en ocho casos, mientras que cuatro pacientes requirieron reintervención con fotocoagulación con láser. No se detectaron complicaciones inmediatas y no hubo pacientes fallecidos.

Ophthalmological outcomes in a series of children with retinopathy of prematurity (ROP) in the threshold stage treated with intravitreal bevacizumab are reported. Twelve very low birth weight (VLBW) preterm infants who were administered intravitreal bevacizumab as monotherapy for retinopathy of prematurity in the threshold stage and in whom standard laser photocoagulation therapy was contraindicated were evaluated. Ophthalmological examinations were carried out and response to treatment, second interventions, and complications were evaluated. The gestational age of these patients was 26.3 ± 1.8 weeks and their birth weight was 845 ± 153 g. A good response was observed in eight cases, while four patients required to be reintervened with laser photocoagulation. No immediate complications were detected and there were no deaths.

Tratamiento de la retinopatía del prematuro con bevacizumab intravítreo / Intravitreal bevacizumab as treatment for retinopathy of prematurity

Introducción: El tratamiento estándar de la Retinopatía del Prematuro (RDP) en etapa umbral es la fotocoagulación con láser (FCL). Recientemente se ha utilizado el bevacizumab, un inhibidor del factor de crecimiento del endotelio vascular (VEGF) con resultados alentadores. Objetivo: Comunicar el resultado del tratamiento con bevacizumab en Recién Nacidos (RN) prematuros con retinopatía en etapa umbral. Pacientes y Método: Se analizaron los RN pretérmino de muy bajo peso (RNMBP) que recibieron bevacizumab, en monoterapia o asociado a FCL, como tratamiento de la RDP en etapa umbral. Se evaluó respuesta al tratamiento, reintervenciones y complicaciones. Resultados: Se analizaron 17 RNMBP con promedio de edad gestacional 26,4 +/- 1,7 sem y peso de nacimiento de 850 +/- 141 g. Los 6 pacientes tratados con bevacizumab en asociación a FCL no requirieron reintervención. De los 11 neonatos que sólo recibieron bevacizumab, el 36,3 por ciento necesitó posteriormente tratamiento con FCL. Conclusiones: El bevacizumab sería una terapia efectiva en el tratamiento de la RDP umbral. En nuestra experiencia presentó ventajas respecto a la FCL, al ser realizado sin necesidad de traslado del RN ni de uso de anestesia general. No observamos complicaciones a corto plazo con el uso de bevacizumab en los pacientes tratados.

Introduction: Standard treatment of threshold Retinopathy of Prematurity (ROP) is laser photocoagulation (LPC). Recently, bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor has been used with positive results. Objective: To communicate the response to treatment with bevacizumab in premature newborns with threshold retinopathy. Patients and Method: Very low birth weight (VLBW) infants that received bevacizumab, in monotherapy or associated with LPC, as treatment for threshold ROP, were analyzed. Response to treatment, reinterventions and complications were evaluated. Results: 17 VLBW infants were analyzed with mean gestational age 26.4 +/- 1.7 weeks and mean birth weight 850 +/- 141 g. All 6 patients treated with bevacizumab in association with LPC did not require reintervention. Of the 11 neonates that only received bevacizumab, 36.3 percent needed further treatment. Conclusions: Bevacizumab could be an effective therapy for treatment of threshold ROP. In our experience it presented advantages compared with LPC, since therapy can be carried out without transferring the patient and with no use of general anesthetics. No short term complications were observed with the use of bevacizumab in treated patients.

Concerted mechanisms of the reactions of methyl aryl carbonates with substituted phenoxide ions.

The reactions of 4-nitrophenyl, 2,4-dinitrophenyl, and 2,4,6-trinitrophenyl methyl carbonates (NPC, DNPC, and TNPC, respectively) with substituted phenoxide ions are subjected to a kinetic study in water at 25.0 degrees C, ionic strength 0.2 M (KCl). Production of the leaving groups (the nitro derivatives) is followed spectrophotometrically. Under excess of the phenoxide ions pseudo-first-order rate coefficients (k(obsd)) are found throughout. Plots of k(obsd) vs substituted phenoxide concentration at constant pH are linear, with the slope (k(N)) independent of pH. The Brönsted-type plots (log k(N) vs pK(a) of the phenols) are linear with slopes beta = 0.67, 0.48, and 0.52 for the phenolysis of NPC, DNPC, and TNPC, respectively. The magnitudes of these Brönsted slopes are consistent with a concerted mechanism. In the particular case of the phenolysis of NPC the expected hypothetical curvature center of the Brönsted plot for a stepwise mechanism should be pK(a)(0) = 7.1 (the pK(a) of 4-nitrophenol). This curvature does not appear within the pK(a) range of the substituted phenols studied (5.3--10.3), indicating that these reactions are concerted. The phenolysis of DNPC and TNPC should also be concerted in view of the even more unstable tetrahedral intermediates that would be formed if the reactions were stepwise. The reactions of the same substrates with pyridines are stepwise, which means that substitution of a pyridine moiety in a tetrahedral intermediate by a phenoxy group destabilizes the intermediate perhaps to the point of nonexistence. The k(N) values for the title reactions are larger than those for the concerted phenolysis of the corresponding ethyl S-aryl thiolcarbonates. The k(N) values found in the present reactions are subjected to a dual regression analysis as a function of the pK(a), of both the nucleophile and leaving group, the coefficients being beta(N) = 0.5 and beta(lg) = -0.3, respectively. These coefficients are consistent with a concerted mechanism.

Patología de la vesícula biliar en la provincia de Llanquihue, Chiloé y Palena, X Región de Chile / Gallbladder pathology at Llanquihue, Chiloé and Palena provinces, X region, Chile

Se estudió en forma prospectiva 973 biopsias de vesícula biliar obtenidas entre período abril 1998 a marzo 1999 (81 por ciento sexo femenino, con relación femenino: masculino 4,5). La edad promedio del grupo fue de 46 años. El 67,1 por ciento del material provenía de Puerto Montt y el resto del área insular (Castro y Ancud). La patología inflamatoria presentó la mayor frecuencia con un 96,5 por ciento y la patología neoplásica un 3,4 por ciento. Se encontraron 23 cánceres de la vesícula biliar, de los que sólo uno era incipiente; en un 91,3 por ciento correspondió a sexo femenino, con un promedio de edad de 63 años. De acuerdo a nuestros resultados, la patología vesicular y en particular el cáncer de la vesícula biliar, presentan una alta frecuencia, al igual que en el resto del país, con mortalidades por sobre el promedio nacional y en donde el estudio anatomopatológico protocolizado de la vesícula biliar contribuye de manera significativa al conocimiento de este tipo de patología

Evaluación clínica de la analgesia dental electrónica / Clinical evaluation of the electronic dental anesthesia

Durante mucho tiempo se ha usado en odontología anestesia química local. Pero ahora, hay una nueva alternativa llamada anestesia dental electrónica. El respaldo fisiológico está basado en la teoría de control de puerta de Melzack y Wall. En el presente estudio, una unidad llamada H-Wave se ha usado para comparar la eficiencia de la anestesia electrónica en lugar de anestesia química. El estudio mostró que no hay diferencias significativas en el efecto anestésico y el 64 por ciento de los pacientes prefirieron la electrónica

Intravitreal bevacizumab as single drug therapy for retinopathy of prematurity in 12 patients. / Intravitreal bevacizumab as single drug therapy for retinopathy of prematurity in 12 patients.

Ophthalmological outcomes in a series of children with retinopathy of prematurity (ROP) in the threshold stage treated with intravitreal bevacizumab are reported. Twelve very low birth weight (VLBW) preterm infants who were administered intravitreal bevacizumab as monotherapy for retinopathy of prematurity in the threshold stage and in whom standard laser photocoagulation therapy was contraindicated were evaluated. Ophthalmological examinations were carried out and response to treatment, second interventions, and complications were evaluated. The gestational age of these patients was 26.3 ± 1.8 weeks and their birth weight was 845 ± 153 g. A good response was observed in eight cases, while four patients required to be reintervened with laser photocoagulation. No immediate complications were detected and there were no deaths.