Caracterización de pacientes pediatricos con hemocultivos positivos del servicio de cuidado intensivo pediatrico del Hospital San José Bogotá, abril 2012 a 2017 / Description of Pediatric Patients with Positive Blood Cultures from the Pediatric Intensive Care Unit at Hospital de San José in Bogotá, April 2012 to 2017

Introducción: El cultivo de la sangre es el método más utilizado en la búsqueda de infecciones del paciente pediátrico porque orienta la terapia antimicrobiana. Objetivo: Determinar la incidencia de hemocultivos positivos y su caracterización microbiológica en pacientes de cuidado intensivo pediátrico del Hospital de San José, Bogotá-Colombia. Materiales y métodos: Descripción de hemocultivos positivos en pacientes pediátricos de la unidad desde abril de 2012 a 2017. Se determinó la incidencia de hemocultivos positivos y se describió la población estudiada y los gérmenes aislados incluido su perfl de antibiograma. Resultados: Ingresaron 1773 pacientes a la UCIP, 241 pacientes (13,6%) fueron hemocultivados, de los cuales 80 (33,2%) fueron positivos, pero 50% de estos fueron catalogados como contaminaciones. La mediana de edad fue de 21 meses, con 64% de sexo masculino. El 57% fue ventilado y 45% tuvieron un catéter central. La mortalidad fue de 15,4%. La patología más frecuentemente fue respiratoria (75%). De los gérmenes no contaminantes el más frecuente aislado fue Staphylococcus aureus (30%), seguido de Klebsiella pneumoniae (17,5%) y Streptococcus pneumoniae (17,5%). El germen contaminante más frecuente fue Staphylococcus epidermidis (47,5%). Conclusión: La frecuencia de hemocultivos positivos es baja y es frecuente que se aíslen gérmenes contaminantes. El patrón fue similar a lo reportado por la red GREBO.

Introduction. Blood culture is the method most used in the search for pediatric infections because it guides the antimicrobial therapy. Objective. To determine the incidence of positive blood cultures and their microbiological characterization in patients of the pediatric intensive care service of San José Hospital, Bogotá-Colombia. Materials and methods: Description of positive blood cultures in pediatric patients of the unit from April 2012 to 2017. The incidence of positive blood cultures was determined and the population studied and the isolated germs were described, including their antibiogram profle. Results: 1773 patients were admitted to the PICU, 241 patients (13.6%) were blood cultures, of which 80 (33.2%) were positive, but 50% of these were classifed as contaminations. The median age was 21 months, with 64% male. 57% were ventilated and 45% had a central catheter. Mortality was 15.4%. The most frequent pathology was respiratory (75%). Of the non-polluting organisms, the most frequent isolate was Staphylococcus aureus (30%), followed by Klebsiella pneumoniae (17.5%) and Streptococcus pneumoniae (17.5%). The most frequent contaminant was Staphylococcus epidermidis (47.5%). Conclusion: The frequency of positive blood cultures is low and polluting organisms are often isolated. The pattern was similar to that reported by the GREBO network.

Riesgo y nivel de actividad física en adultos, en un programa de estilos de vida saludables en Popayán / Risk and physical activity level in adults in a healthy lifestyle program in Popayán

RESUMEN Objetivo Caracterizar el riesgo y el nivel de actividad física de los participantes de un programa de hábitos y estilos de vida saludables en el municipio de Popayán, durante el primer semestre de 2015. Métodos Estudio descriptivo de corte transversal, en la población adulta que participa en un programa de promoción de la Salud de la Gobernación del Cauca que acoge una población de 500 usuarios de las comunas 1 y 3. La información se colectó a través del cuestionario IPAQ, además de estratificar el riesgo para la práctica de ejercicio físico con el cuestionario PAR-Q. Resultados Los resultados arrojan una prevalencia de 18,3 % para actividad física vigorosa y moderada, el grupo poblacional que mayor porcentaje de actividad física realizo fue el adulto joven (18-35 años), el 64 % de la población se encuentran en riesgo alto para la práctica de ejercicio físico. Conclusiones Los resultados obtenidos estratifican a la mayoría de la población en alto riesgo para la práctica de ejercicio físico y confirman bajos niveles de actividad física entre moderada y vigorosa, pero dejan entrever la importancia de la realización de evaluaciones previas a la vinculación a programas de ejercicio físico, como medidas de seguridad, control y seguimiento del estado de salud en los usuarios.(AU)

ABSTRACT Objective To characterize risk and physical activity level of the participants in a program of healthy habits and lifestyles in the city of Popayán during the first semester of 2015. Methods Cross-sectional study on the adult population participating in a health promotion program developed by the Cauca Governor's Office with 500 users. Information was collected through the IPAQ questionnaire and risk for physical exercise was classified using the PAR-Q questionnaire. Results The results show a prevalence of 18.3 % for moderate and vigorous physical activity. The population group with the highest percentage of physical activity was found in young adults (aged 18-35 years), while 64 % of the population are at high risk regarding practicing physical exercise. Conclusions The results obtained show that most of the population is at high risk regarding physical activity and also confirm low levels of moderate and vigorous physical activity. However, they also show signs of the importance of making evaluations prior to developing physical activity programs, such as security measures and control and monitoring of health status of the users.(AU)

[Risk and physical activity level in adults in a healthy lifestyle program in Popayán]. / Riesgo y nivel de actividad física en adultos, en un programa de estilos de vida saludables en Popayán.

OBJECTIVE: To characterize risk and physical activity level of the participants in a program of healthy habits and lifestyles in the city of Popayán during the first semester of 2015. METHODS: Cross-sectional study on the adult population participating in a health promotion program developed by the Cauca Governor's Office with 500 users. Information was collected through the IPAQ questionnaire and risk for physical exercise was classified using the PAR-Q questionnaire. RESULTS: The results show a prevalence of 18.3 % for moderate and vigorous physical activity. The population group with the highest percentage of physical activity was found in young adults (aged 18-35 years), while 64 % of the population are at high risk regarding practicing physical exercise. CONCLUSIONS: The results obtained show that most of the population is at high risk regarding physical activity and also confirm low levels of moderate and vigorous physical activity. However, they also show signs of the importance of making evaluations prior to developing physical activity programs, such as security measures and control and monitoring of health status of the users.

OBJETIVO: Caracterizar el riesgo y el nivel de actividad física de los participantes de un programa de hábitos y estilos de vida saludables en el municipio de Popayán, durante el primer semestre de 2015. MÉTODOS: Estudio descriptivo de corte transversal, en la población adulta que participa en un programa de promoción de la Salud de la Gobernación del Cauca que acoge una población de 500 usuarios de las comunas 1 y 3. La información se colectó a través del cuestionario IPAQ, además de estratificar el riesgo para la práctica de ejercicio físico con el cuestionario PAR-Q. RESULTADOS: Los resultados arrojan una prevalencia de 18,3 % para actividad física vigorosa y moderada, el grupo poblacional que mayor porcentaje de actividad física realizo fue el adulto joven (18-35 años), el 64 % de la población se encuentran en riesgo alto para la práctica de ejercicio físico. CONCLUSIONES: Los resultados obtenidos estratifican a la mayoría de la población en alto riesgo para la práctica de ejercicio físico y confirman bajos niveles de actividad física entre moderada y vigorosa, pero dejan entrever la importancia de la realización de evaluaciones previas a la vinculación a programas de ejercicio físico, como medidas de seguridad, control y seguimiento del estado de salud en los usuarios.

Trasplante alogénico haploidéntico de progenitores hematopoyéticos en pediatría en Uruguay / Haploidentical allogeneic hematopoietic transplant of hematopoietic parents in pediatrics in Uruguay

Introducción: el trasplante alogénico de progenitores hematopoyéticos (TPH) es actualmente la única opción de tratamiento curativo disponible para un número de neoplasias hematológicas de alto riesgo, así como para algunas enfermedades no malignas hereditarias o adquiridas. El TPH haploidéntico (HI) es una opción válida para pacientes que no tienen un hermano HLA-idéntico. Objetivo: describir los resultados obtenidos con TPH HI en pediatría. Material y método: en el año 2005 se inició en el Centro Hemato-Oncológico Pediátrico del Centro Hospitalario Pereira Rossell un programa de TPH HI para aquellos pacientes sin donante relacionado HLA-idéntico. Resultados: se trasplantaron 32 pacientes, 24 con neoplasias hematológicas y 8 con enfermedades no malignas. Se utilizaron dos estrategias de prevención de la enfermedad injerto contra huésped (EICH), depleción de linfocitos T (DLT) in vitro (28 pacientes) y DLT alorreactivos in vivo con altas dosis de ciclofosfamida postrasplante (4 pacientes). Veintisiete pacientes (84%) tuvieron un implante con quimerismo total del donante. La incidencia de EICH agudo y crónico fue de 26,9% y 11,8%, respectivamente. La muerte no relacionada a recaída al año del trasplante fue de 21,9%. Con una mediana de seguimiento de 32 meses, la sobrevida global a dos años fue de 52,4%. Conclusiones: el TPH HI ha demostrado ser una opción factible en nuestro medio para aquellos pacientes sin donante HLA-idéntico. Los resultados son comparables a los obtenidos con otros donantes alternativos y con costos más accesibles. Uruguay está hoy día mejor posicionado para ofrecer un TPH a los pacientes que así lo requieran...

Synthesis and properties of novel star-shaped oligofluorene conjugated systems with BODIPY cores.

Star-shaped conjugated systems with varying oligofluorene arm length and substitution patterns of the central BODIPY core have been synthesised, leading to two families of compounds, T-B1-T-B4 and Y-B1-Y-B4, with T- and Y-shaped motifs, respectively. Thermal stability, cyclic voltammetry, absorption and photoluminescence spectroscopy of each member of these two families were studied in order to determine their suitability as emissive materials in photonic applications.

Compuestos fenólicos y carotenoides en la papa: revisión / Phenolic compounds and carotenoids in potatoes: revision / Compostos fenólicos e carotenóides na batata: revisão

Las papas nativas presentan una gran diversidad de formas, colores y tamaños. En cuanto al color,existen papas con piel amarilla, roja, rosada o morada. Los colores cremas, anaranjados y amarillos son indicativos de la presencia de carotenoides. Los colores rosa, rojo, azul, malva y violeta de ciertos vegetales se deben ala presencia de compuestos fenólicos, entre ellos las antocianinas. Los compuestos fenólicos y los carotenoides son antioxidantes naturales que muestran la capacidad de capturar radicales libres causantes del estrés oxidativo en las células. Por este motivo, la ingesta de papa puede generar un efecto beneficioso en la prevención de enfermedades cardiovasculares, circulatorias, oncológicas y neurológicas. Asimismo, en esta revisión se encontró que existe una variación en la concentración de los compuestos fenólicos y carotenoides en la papa, debido a factores como el color del tubérculo, las condiciones ambientales del cultivo, los procesos de cocción y las condiciones de almacenamiento.

Native potatoes present a wide variety of shapes, colors and sizes. Regarding their color, we can find potatoes with yellow, red, pink or purple skin; however, orange and yellow skins are indicative of the presence of carotenoids. The pink, red, blue, mauve and purple skins in certain vegetables indicate the presence of phenolic compounds, including anthocyanins. Phenolic compounds and carotenoids are natural antioxidants which show a capacity to catch free radicals which cause oxidative stress in cells. Therefore, potato intake may generate a beneficial effectin the prevention of cardiovascular, circulatory, onchological and neurological diseases. Also, it was found in this review that there is a variation in the concentration of phenolic compounds and carotenoids in the potato, affected by factors such as the tuber color, environmental conditions, the cooking process and storage conditions.

As batatas nativas apresentam uma grande diversidade de formas, cores e tamanhos. Quanto à cor, existem batatas com casca amarela, vermelha, rosada ou roxa. As cores creme, laranja e amarelo são indicativos da presença de carotenóides. As cores rosa, vermelho, azul, roxo e violeta de certos vegetais devem-se à presença de compostos fenólicos, entre eles as antocianinas. Os compostos fenólicose os carotenóides são antioxidantes naturais que mostram a capacidade de capturar radicais livreis que são os causadores do estresse oxidativo nas células. Por este motivo, a ingestão de batata pode gerar um efeito benéfico na prevenção de doenças cardiovasculares, circulatórios, oncológicas e neurológicas. Nesta revisão também foi encontrada a existência de uma variação na concentração dos compostos fenólicose carotenóides na batata, devido a fatores como a cor do tubérculo, as condições ambientais do cultivo, os processos de cocção e as condições de armazenamento.

Properties of antibodies to a synthetic peptide representing an epitope shared by receptors of the type I cytokine family.

Previous works from our laboratory demonstrated that the monoclonal antibody (MAb) called R7B4 is directed to an epitope shared by various receptors corresponding to the type I cytokine receptor family, containing the common motif WSXWS or the homologous F(Y)GEFS. Later a consensus peptide significantly recognized by the MAb was identified and synthesized (sequence HGYWSEWSPE). In the present work, an homologous of the consensus sequence (HHGYWSEWSPE) was conjugated to PADRE adjuvant to produce Ab that could simulate theMAb activity, that is, acting as hormone and/or cytokine antagonists. The covalently conjugated peptide-PADRE was a better immunogen than the consensus peptide alone according to the reactivity of sera from C57BL/6 immunized mice and, besides, no Ab to PADRE were detected. Furthermore, Ab to consensus peptide elicited after peptide-PADRE inoculation into mice behaved as immunomodulatory agents, since they improved the humoral response to a foreign antigen (in this case ovalbumin). In addition, the Ab inhibited the in vitro proliferation of various cell lines, mainly cells derived from human and mouse breast cancer. Thus, immunization with the conjugate peptide-PADRE prepared under the experimental conditions described herein originated immunomodulatory Ab that, in the future, could be tested in some pathological conditions.

Angiotensin-(1-7) upregulates central nitric oxide synthase in spontaneously hypertensive rats.

Increased blood pressure in hypertension is hypothesized to be caused by high sympathetic nervous system (SNS) activity. Since Ang (1-7) exerts an inhibitory neuromodulatory effect on the SNS through a NO-mediated mechanism, we tested the hypothesis that Ang (1-7) alters centrally nitric oxide synthase (NOS) activity and expression in spontaneously hypertensive rats (SHR). Since NOS activity is altered in relation to the development of hypertension in rats, we evaluated the effect of Ang-(1-7) on hypothalamic NOS activity in two different ages in SHR, corresponding to a prehypertensive phase (3-4 weeks) and a established hypertension (13-14 weeks) and compared with age-matched Wistar-Kyoto (WKY) rats. NOS activity was measured by the conversion of [³H]L-arginine to citrulline. Ang-(1-7) caused an impairment in NOS activity in prehypertensive SHR (26 ± 4% reduction), while it induced an increase in NOS activity at established hypertension (48 ± 9% increase). In contrast, Ang-(1-7) did not modify NOS activity in age-matched WKY rats. In another set of experiments, Ang-(1-7) was injected into the anterior hypothalamic area, mean arterial blood pressure (MAP) was registered and after 30, 60 and 180 min nNOS expression was evaluated by Western-blot. Ang-(1-7) decreased MAP after 10 min of injection and this effect was blocked by a NOS inhibitor. nNOS expression increased after 180 min of Ang-(1-7) intrahypothalamic injection in both WKY and SHR (WKY: 3.6-fold increase above basal; SHR: 1.85-fold increase above basal). Our results suggest that Ang-(1-7) upregulates hypothalamic NOS in a hypertensive state as a compensatory and protective mechanism to combat hypertension.

Autoimmune hepatitis-like disease in C57BL/6 mice infected with mouse hepatitis virus A59.

Mouse hepatitis virus A59 (MHV A59) induces autoantibodies (autoAb) to fumarylacetoacetate hydrolase (FAH), a soluble cytosolic enzyme present in the liver and kidneys, in various mouse strains. The aim of this work was to amplify and diversify the autoimmune response restricted to FAH through the use of the exogenous adjuvant called PADRE. Accordingly, C57BL/6 mice were chosen, because these animals respond to PADRE better than other mouse strains. Results presented herein indicate that, surprisingly, C57BL/6 mice developed signs of autoimmune hepatitis-like disease (AIH), including transient hypergammaglobulinemia, elevated transaminases, autoAb directed against different liver proteins and hepatic cellular infiltrates, indicating that a new model of experimental AIH could be generated by a viral inoculation. Furthermore, PADRE administration amplified the MHV effect, extending the duration of hypergammaglobulinemia and increasing the binding of autoAb as well as the degree of hepatic infiltrates. However, the adjuvant did not expand the time of the symptoms. Additionally, since plasmatic uric acid and high-mobility group box protein 1 (HGMB1) concentrations augmented in MHV- and/or PADRE-treated mice, it is suggested that both alarmins were probably involved in the spreading of the immune response induced by the viral infection and the adjuvant administration.

Changes in Na+, K+-ATPase activity and alpha 3 subunit expression in CNS after administration of Na+, K+-ATPase inhibitors.

The expression of Na(+), K(+)-ATPase α3 subunit and synaptosomal membrane Na(+), K(+)-ATPase activity were analyzed after administration of ouabain and endobain E, respectively commercial and endogenous Na(+), K(+)-ATPase inhibitors. Wistar rats received intracerebroventricularly ouabain or endobain E dissolved in saline solution or Tris-HCl, respectively or the vehicles (controls). Two days later, animals were decapitated, cerebral cortex and hippocampus removed and crude and synaptosomal membrane fractions were isolated. Western blot analysis showed that Na(+), K(+)-ATPase α3 subunit expression increased roughly 40% after administration of 10 or 100 nmoles ouabain in cerebral cortex but remained unaltered in hippocampus. After administration of 10 µl endobain E (1 µl = 28 mg tissue) Na(+), K(+)-ATPase α3 subunit enhanced 130% in cerebral cortex and 103% in hippocampus. The activity of Na(+), K(+)-ATPase in cortical synaptosomal membranes diminished or increased after administration of ouabain or endobain E, respectively. It is concluded that Na(+), K(+)-ATPase inhibitors modify differentially the expression of Na(+), K(+)-ATPase α3 subunit and enzyme activity, most likely involving compensatory mechanisms.

Angiotensin-(1-7) upregulates cardiac nitric oxide synthase in spontaneously hypertensive rats.

It has been shown that angiotensin (ANG)-(1-7) activates nitric oxide synthase (NOS) in isolated ventricular myocytes from normotensive rats. Since many ANG-(1-7) actions are enhanced in situations of increased ANG II activity, as in hypertension, in this study we investigated the in vivo effect of ANG-(1-7) on NOS activity and expression of endothelial (eNOS), neuronal (nNOS), and inducible NOS (iNOS) in ventricles from spontaneously hypertensive rats (SHR). Rats were subjected to a 60-min ANG-(1-7) infusion (0.35 nmol/min); controls received saline. NOS activity was measured using the NADPH diaphorase histochemical method and by the conversion of L-[(14)C]arginine to citrulline, and NOS phosphorylation and expression were determined using Western blotting. In SHR, ANG-(1-7) infusion diminished mean arterial pressure from 180 ± 9 to 146 ± 9 mmHg (P < 0.05), and this effect was prevented by nitro-l-arginine methyl ester (l-NAME), a NOS inhibitor. In addition, NOS activity and eNOS phosphorylation were increased by ANG-(1-7) infusion. Ventricular eNOS and nNOS expression were increased 67.4 ± 6.4 and 51 ± 10%, respectively, by ANG-(1-7), whereas iNOS was not changed. In another set of experiments, we evaluated the mechanism by which ANG-(1-7) modifies NOS activity. Isolated ventricle slices preincubated with ANG-(1-7) showed an increase in NOS activity and eNOS phosphorylation, which was blocked by an AT(2) and a bradykinin B(2) receptor antagonist, but not by the Mas receptor antagonist. Our results show that in rats in a hypertensive state, ANG-(1-7) infusion upregulates cardiac NOS expression and activity through an AT(2)- and bradykinin-dependent mechanism. In this way ANG-(1-7) may elicit its cardioprotective action and contribute to some of the counterregulatory AT(2) receptor effects that oppose the AT(1) receptor-mediated effects.

STAT1, STAT3 and p38MAPK are involved in the apoptotic effect induced by a chimeric cyclic interferon-alpha2b peptide.

In the search of mimetic peptides of the interferon-alpha2b molecule (IFN-alpha2b), we have previously designed and synthesized a chimeric cyclic peptide of the IFN-alpha2b that inhibits WISH cell proliferation by inducing an apoptotic response. Here, we first studied the ability of this peptide to activate intracellular signaling pathways and then evaluated the participation of some signals in the induction of apoptosis. Stimulation of WISH cells with the cyclic peptide showed tyrosine phosphorylation of Jak1 and Tyk2 kinases, tyrosine and serine phosphorylation of STAT1 and STAT3 transcription factors and activation of p38 MAPK pathway, although phosphorylation levels or kinetics were in some conditions different to those obtained under IFN-alpha2b stimulus. JNK and p44/42 pathways were not activated by the peptide in WISH cells. We also showed that STAT1 and STAT3 downregulation by RNA interference decreased the antiproliferative activity and the amount of apoptotic cells induced by the peptide. Pharmacological inhibition of p38 MAPK also reduced the peptide growth inhibitory activity and the apoptotic effect. Thus, we demonstrated that the cyclic peptide regulates WISH cell proliferation through the activation of Jak/STAT signaling pathway. In addition, our results indicate that p38 MAPK may also be involved in cell growth regulation. This study suggests that STAT1, STAT3 and p38 MAPK would be mediating the antitumor and apoptotic response triggered by the cyclic peptide in WISH cells.

Losartan exerts renoprotection through NAD(P)H oxidase downregulation in a renovascular model of hypertension.

This study was performed to provide insight into the regulatory role of angiotensin II and arterial pressure on the activity of antioxidant enzymes and oxidative stress generation in the hypertensive kidney from an experimental animal model of renovascular hypertension. Aortic coarcted and sham-operated rats received vehicle, losartan or minoxidil in their drinking water. After 7 d of treatment rats were sacrificed; hypertensive kidneys were excised, and the NAD(P)H oxidase subunits expression, TBARS production, glutathione level and the activity of heme oxygenase-1 and classical antioxidant enzymes, were evaluated. Losartan administration significantly reduced oxidative stress generation decreasing NAD(P)H oxidase expression, independently of the drop in arterial pressure. On the other hand, antioxidant enzymes were regulated by arterial pressure and they were not implicated in kidney protection against oxidative damage. Findings here reported strongly suggest that clinical therapeutics with the Ang II type 1 receptor blocker prevents oxidative stress generation and may attenuate the kidney oxidative damage in the renovascular hypertension. We hypothesize that the pathway followed by the Ang II blocker to achieve this renoprotection, though independent of the primary antioxidant enzymatic system, depends on NAD(P)H oxidase downregulation.

High-affinity neurotensin receptor is involved in phosphoinositide turnover increase by inhibition of sodium pump in neonatal rat brain.

Phosphoinositide (PI) metabolism is enhanced in neonatal brain by activation of neurotransmitter receptors and by inhibition of the sodium pump with ouabain or endogenous inhibitor termed endobain E. Peptide neurotensin inhibits synaptosomal membrane Na(+), K(+)-ATPase activity, an effect blocked by SR 48692, a selective antagonist for high-affinity neurotensin receptor (NTS1). The purpose of this study was to evaluate potential participation of NTS1 receptor on PI hydrolysis enhancement by sodium pump inhibition. Cerebral cortex miniprisms from neonatal Wistar rats were preloaded with [(3)H]myoinositol in buffer during 60 min and further preincubated for 0 min or 30 min in the absence or presence of SR 48692. Then, ouabain or endobain E were added and incubation proceeded during 20 or 60 min. Reaction was stopped with chloroform/methanol and [(3)H]inositol-phosphates (IPs) accumulation was quantified in the water phase. After 60-min incubation with ouabain, IPs accumulation values reached roughly 500% or 860% in comparison with basal values (100%), if the preincubation was omitted or lasted 30 min, respectively. Values were reduced 50% in the presence of SR 48692. In 20-min incubation experiments, IPs accumulation by ouabain versus basal was 300% or 410% if preincubation was 0 min or 30 min, respectively, an effect blocked 23% or 32% with SR 48692. PI hydrolysis enhancement by endobain E was similarly blocked by SR 48692, being this effect higher when sample incubation with the endogenous inhibitor lasted 60 min versus 20 min. Present results indicate that PI hydrolysis increase by sodium pump inhibition with ouabain or endobain E is partially diminished by SR 48692. It is therefore suggested that NTS1 receptor may be involved in cell signaling system mediated by PI turnover.

The expression of NMDA receptor subunits in cerebral cortex and hippocampus is differentially increased by administration of endobain E, a Na+, K+-ATPase inhibitor.

Previous studies showed that endobain E, an endogenous Na+, K+-ATPase inhibitor, decreases dizocilpine binding to NMDA receptor in isolated membranes. The effect of endobain E on expression of NMDA receptor subunits in membranes of rat cerebral cortex and hippocampus was analyzed by Western blot. Two days after administration of 10 mul endobain E (1 microl = 29 mg fresh tissue) NR1 subunit expression enhanced 5-fold and 2.5-fold in cerebral cortex and hippocampus, respectively. NR2A subunit expression increased 2-fold in cerebral cortex and 1.5-fold in hippocampus. The level of NR2B subunit raised 3-fold in cerebral cortex but remained unaltered in hippocampus. NR2C subunit expression was unaffected in either area. NR2D subunit enhanced 1.6 and 2.1-fold for cerebral cortex and hippocampus, respectively. Results indicate that endogenous Na+, K+-ATPase inhibitor endobain E differentially modifies the expression of NMDA receptor subunits.

Identification, synthesis and properties of a consensus peptide recognized by a monoclonal antibody directed to various type I cytokine receptors.

Previous works demonstrated that the monoclonal antibody (MAb) called R7B4 is directed to an epitope shared by receptors for lactogenic and somatogenic hormones as well as interleukins 2 and 6 (IL-2 and IL-6). The MAb inhibited the biological effects of those hormones and cytokines by impairing their binding to receptors. It is known that the receptors for growth hormones (GH), prolactins (PRL), IL-2, and IL-6 pertain to the type I cytokine receptor family, sharing the common motif WSXWS or the homologous F(Y)GEFS. Thus, a set of 34 decapeptides corresponding to diverse receptors containing those sequences were synthesized by the PEPSCAN method and their reactions with MAb R7B4 were measured by ELISA. The MAb significantly recognized 21 peptides, allowing us to establish the consensus sequence HGYWSEWSPE as a portion of the R7B4 epitope. The consensus peptide was synthesized and purified by conventional methods, and its capacity to bind to MAb R7B4 paratope confirmed. Moreover, polyclonal Ab to the peptide elicited in mice were able to inhibit the hGH binding to lactogenic, somatogenic and human specific liver receptors. This fact suggests that the consensus peptide could be used as an immunogen to produce anti-hGH receptor Ab behaving as hormone or cytokine antagonists in certain pathological conditions.

Increased hypothalamic angiotensin-(1-7) levels in rats with aortic coarctation-induced hypertension.

Since angiotensin (Ang) (1-7) injected into the brain blocked Ang II pressor actions in rats made hypertensive by aortic coarctation (CH), we examined systemic and tissue angiotensin peptide levels, specifically concentrating on the hypothalamic Ang-(1-7) levels. Plasma, heart and kidney isolated from CH rats showed increased levels of Ang I, Ang II and Ang-(1-7) compared with the normotensive group, with Ang II being the predominant peptide in heart and kidney. In the hypothalamus, equimolar amounts of Ang II and Ang-(1-7) were found in the sham group, whereas only Ang-(1-7) levels increased in CH rats. We conclude that aortic coarctation activates systemic and tissue renin-angiotensin system. The increased central levels of Ang-(1-7) in the CH rats suggest a potential mitigating role of this peptide in central control of the hypertensive process.

Angiotensin-(1-7) blocks the angiotensin II-stimulated superoxide production.

Angiotensin (Ang)-(1-7), a bioactive compound of the renin-angiotensin system, exerts effects leading to blood pressure reduction which counterbalance Ang II pressor actions. The present study was conducted to examine Ang-(1-7) and Ang II effects on superoxide anion production in rat aorta using the lucigenin chemiluminescence method. Ang II dose-dependently increased superoxide anion formation when compared to control levels; a maximal increase (2.5-fold) was observed with 1 x 10(-10)M peptide concentration. The Ang II-stimulated superoxide formation was blocked by 1 x 10(-10)M losartan, the specific AT(1) receptor antagonist, but not by 1 x 10(-10)M PD 123319, the AT(2) receptor antagonist, suggesting that the increased superoxide levels caused by Ang II are mediated through AT(1) receptors activation. The Ang II-stimulated superoxide production was not modified by 2 x 10(-8)M allopurinol or 1 x 10(-7)M indomethacin, but was completely abolished by NAD(P)H oxidase inhibitors: 1 x 10(-8)M diphenylene iodonium, or 2 x 10(-8)M apocynin, demonstrating that NAD(P)H oxidase participates in such response. In contrast to Ang II, Ang-(1-7) concentrations ranging 1 x 10(-12) to 1 x 10(-6)M did not modify superoxide anion levels, but prevented the Ang II-enhanced superoxide production. In conclusion, we demonstrated that Ang-(1-7) blocks the pro-oxidant effects of Ang II, thus reducing the superoxide anion production and delaying the hypertension development.

Angiotensin-(1 7) stimulates the phosphorylation of JAK2, IRS-1 and Akt in rat heart in vivo: role of the AT1 and Mas receptors.

Angiotensin (ANG) II exerts a negative modulation on insulin signal transduction that might be involved in the pathogenesis of hypertension and insulin resistance. ANG-(1-7), an endogenous heptapeptide hormone formed by cleavage of ANG I and ANG II, counteracts many actions of ANG II. In the current study, we have explored the role of ANG-(1-7) in the signaling crosstalk that exists between ANG II and insulin. We demonstrated that ANG-(1-7) stimulates the phosphorylation of Janus kinase 2 (JAK2) and insulin receptor substrate (IRS)-1 in rat heart in vivo. This stimulating effect was blocked by administration of the selective ANG type 1 (AT(1)) receptor blocker losartan. In contrast to ANG II, ANG-(1-7) stimulated cardiac Akt phosphorylation, and this stimulation was blunted in presence of the receptor Mas antagonist A-779 or the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin. The specific JAK2 inhibitor AG-490 blocked ANG-(1-7)-induced JAK2 and IRS-1 phosphorylation but had no effect on ANG-(1-7)-induced phosphorylation of Akt, indicating that activation of cardiac Akt by ANG-(1-7) appears not to involve the recruitment of JAK2 but proceeds through the receptor Mas and involves PI3K. Acute in vivo insulin-induced cardiac Akt phosphorylation was inhibited by ANG II. Interestingly, coadministration of insulin with an equimolar mixture of ANG II and ANG-(1-7) reverted this inhibitory effect. On the basis of our present results, we postulate that ANG-(1-7) could be a positive physiological contributor to the actions of insulin in heart and that the balance between ANG II and ANG-(1-7) could be relevant for the association among insulin resistance, hypertension, and cardiovascular disease.

Phosphoinositide hydrolysis increase by angiotensin-(1--7) in neonatal rat brain.

Angiotensin (Ang)-(1-7) is an endogenous peptide hormone of the renin-angiotensin system which exerts diverse biological actions, some of them counterregulate Ang II effects. In the present study potential effect of Ang-(1-7) on phosphoinositide (PI) turnover was evaluated in neonatal rat brain. Cerebral cortex prisms of seven-day-old rats were preloaded with [(3)H]myoinositol, incubated with additions during 30 min and later [(3)H]inositol-phosphates (IPs) accumulation quantified. It was observed that PI hydrolysis enhanced 30% to 60% in the presence of 0.01 nM to 100 nM Ang-(1-7). Neither 10 nM [D-Ala(7)]Ang-(1-7), an Ang-(1-7) specific antagonist, nor 10 nM losartan, an angiotensin II type 1 (AT(1)) receptor antagonist, blocked the effect of 0.1 nM Ang-(1-7) on PI metabolism. The effect of 0.1 nM Ang-(1-7) on PI hydrolysis was not reduced but it was even significantly increased in the simultaneous presence of [D-Ala(7)]Ang-(1-7) or losartan. PI turnover enhancement achieved with 0.1 nM Ang-(1-7) decreased roughly 30% in the presence of 10 nM PD 123319, an angiotensin II type 2 (AT(2)) receptor antagonist. The antagonists alone also enhanced PI turnover. Present findings showing an increase in PI turnover by Ang-(1-7) represent a novel action for this peptide and suggest that it exerts a function in this signaling system in neonatal rat brain, an effect involving, at least partially, angiotensin AT(2) receptors.