RESUMO

ntroducción: La enseñanza de la Farmacología tradicionalmente se ha caracterizado por la transmisión de información donde las estrategias pedagógicas se han centrado en el profesor, privilegiando el conocimiento teórico, las clases magistrales y los exámenes memorísticos. Es imprescindible la introducción de elementos nuevos para aumentar la participación activa del estudiante en la construcción del conocimiento y en la evaluación del logro de sus competencias; el desarrollo de la creatividad y el trabajo en equipo. Esta metodología busca romper la noción de enseñanza tradicional, cambiar la idea de una evaluación por la nota a una evaluación con una motivación propia (del estudiante), para internalizar el conocimiento y hacerlo parte desu estructura de pensamiento. Objetivo: Desarrollar una estrategia de enseñanza y evaluación que permita a los estudiantes participar activamente. Materiales y métodos: Participaron 172 estudiantes que cursaron la asignatura de Farmacología y Terapéutica "B", entre marzo y septiembre de 2017. Se desarrollaron cuatro actividades individuales y complementarias relacionadas con la prescripción de medicamentos, para la evaluación del proceso y desempeño de los estudiantes se emplearon rúbricas normalizadas de evaluación, se aplicó una encuestade percepción a los estudiantes sobre la utilidad de la estrategia en su formación. Resultados: Los resultados muestran un buen desempeño de los estudiantes en las actividades de prescripción de medicamentos, un mejoramiento significativo en el desempeño al comparar los resultados. Los estudiantes consideran que la estrategia es útil para el desarrollo de sus competencias profesionales, les permite tener un papel activo en el proceso de aprendizaje y la metodología de evaluación les permite reconocer los elementos que deben reforzar para llegar a un óptimo desarrollo de su competencia

Assuntos

Humanos , Masculino , Feminino , Adolescente , Adulto , Farmacologia , Avaliação Educacional , Práticas Interdisciplinares , Aprendizagem , Tecnologia da Informação

RESUMO

Previously, we found out that in ovariectomized female rats, estrogen and progesterone produce a memory deficit which is reverted by the intrahippocampal administration of allopregnanolone. Here, we study the possible interplay between allopregnanolone and hippocampal serotonergic activity. Ovariectomized rats injected subcutaneously with estrogen and progesterone were subsequently injected in the dorsal hippocampus with vehicle, allopregnanolone alone or allopregnanolone shortly after 8OH-DPAT, a predominantly 5HT1A-7 receptor agonist. Then, the subjects were sequentially tested in: (1) an inhibitory avoidance task and (2) K+-evoked [3H]-serotonin ex vivo release through superfusion experiments. Allopregnanolone increased the K+-evoked [3H]-serotonin release compared to control. 8OH-DPAT infusions reversed the effects of allopregnanolone on memory and K+-evoked [3H]-serotonin release. These results suggest that allopregnanolone memory improvement could be mediated, at least in part, through modulation of the hippocampal serotonergic system reactivity.

Assuntos

Estrogênios/farmacologia , Transtornos da Memória/metabolismo , Transtornos da Memória/prevenção & controle , Pregnanolona/uso terapêutico , Progesterona/farmacologia , Serotonina/metabolismo , Animais , Feminino , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Transtornos da Memória/induzido quimicamente , Ovariectomia/efeitos adversos , Pregnanolona/farmacologia , Ratos , Ratos Sprague-Dawley , Agonistas do Receptor de Serotonina/farmacologia

RESUMO

During the development of the sympathetic nervous system, signals from tropomyosin-related kinase receptors (Trks) and p75 neurotrophin receptors (p75) compete to regulate survival and connectivity. During this process, nerve growth factor (NGF)- TrkA signaling in axons communicates NGF-mediated trophic responses in signaling endosomes. Whether axonal p75 signaling contributes to neuronal death and how signaling endosomes contribute to p75 signaling has not been established. Using compartmentalized sympathetic neuronal cultures (CSCGs) as a model, we observed that the addition of BDNF to axons increased the transport of p75 and induced death of sympathetic neurons in a dynein-dependent manner. In cell bodies, internalization of p75 required the activity of JNK, a downstream kinase mediating p75 death signaling in neurons. Additionally, the activity of Rab5, the key GTPase regulating early endosomes, was required for p75 death signaling. In axons, JNK and Rab5 were required for retrograde transport and death signaling mediated by axonal BDNF-p75 in CSCGs. JNK was also required for the proper axonal transport of p75-positive endosomes. Thus, our findings provide evidence that the activation of JNK by p75 in cell bodies and axons is required for internalization to a Rab5-positive signaling endosome and the further propagation of p75-dependent neuronal death signals.

Assuntos

Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/patologia , Receptores de Fatores de Crescimento/metabolismo , Proteínas rab5 de Ligação ao GTP/metabolismo , Animais , Apoptose/efeitos dos fármacos , Axônios/metabolismo , Células Cultivadas , Endossomos/metabolismo , Feminino , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Masculino , Neurônios/citologia , Neurônios/metabolismo , Cultura Primária de Células , Ratos , Receptor trkA/metabolismo , Gânglio Cervical Superior/citologia

RESUMO

Estudios han demostrado que el aceite de oliva (O) con sus compuestos fenólicos tienen efectos positivos en diversos biomarcadores fisiológicos. Análisis previos han demostrado que los bisfosfonatos, son potentes inhibidores de la resorción ósea. Estudiar el efecto del tratamiento combinado de alendronato (AL) y pamidronato (PA) y de O sobre la regeneración ósea. Las fórmulas se dosificaron 0,5 mg/kg de peso para AL, y de 0,6 mg/kg de peso para PA. El O se administró en la dieta, 50 g/Kg. Cincuenta y cuatro ratas macho de la línea Wistar se dividieron en 6 grupos. El grupo control (C), recibió semanalmente 0,3 ml/100 g de solución salina vía subcutánea. El grupo (AL) recibió semanalmente por vía subcutánea en el miembro posterior izquierdo. El grupo (PA) se colocó igual que el grupo anterior. El grupo (O) fue tratado en la alimentación y en las áreas de la cirugía recibieron inyección subcutánea con solución fisiológica. El grupo (ALO) recibió tratamiento combinado con AL y O. El grupo (PAO) se trató igual al anterior. Se obtuvieron muestras de fémur en tiempos 15, 30, 60 y 90 días, que se incluyeron en solución fisiológica y mantenidos a -20 C. Los estudios estadísticos se realizaron a través del análisis de la variancia a dos y tres criterios de clasificación. Sólo el factor días influye significativamente sobre los valores. Las diferencias entre drogas no resultaron estadísticamente significativas. Tampoco se verificó interacción significativa entre los factores Droga y etapa. Los valores más elevados de fuerza de ruptura aplicada, se registraron a los 90 días. No se encontraron diferencias significativas en los ensayos biomecánicos, poniendo de manifiesto la acción sistémica de los fármacos. Estas acciones fueron benéficas al aumentar la rigidez.

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Studies have shown that olive oil (O) with its phenolic compounds have positive effects on various physiological biomarkers. Previous analyzes have shown that bisphosphonates are potent inhibitors of bone resorption. The objective of this work was to study the effect of combined treatment with alendronate (AL) and pamidronate (PA) and O on bone regeneration. Formulas 0.5 mg/kg for AL dosed, and 0.6 mg/kg for PA. O was administered in the diet, 50 g/kg. Fifty-four male Wistar rats were divided into 6 groups. The control group (C) received weekly 0.3 mL/100 g of saline subcutaneously. Group (AL) received weekly subcutaneously in the left posterior limb. Group (PA) was placed as the previous group. Group (O) was treated in food and in the areas of surgery received subcutaneous injection with saline. The (ALO) group received combined treatment with Al and O. The group (PAO) was treated the same as before. Femur samples at times 15, 30, 60 and 90 days, were included in physiological solution and maintained at -20 °C were obtained. Statistical studies were conducted through analysis of variance to two and three classification criteria. The ANOVA showed that only days factor significantly influences the values of the variables (p <0.05). The differences between drugs were not statistically significant (p> 0.05). Nor was there significant drug interaction between factors and stage (p> 0.05) was verified. The highest values of force rupture applied occurred at 90 days. No significant differences were found in the biomechanical testing, demonstrating the systemic action of drugs. These actions were beneficial to increase rigidity.

Assuntos

Animais , Masculino , Ratos , Regeneração Óssea/efeitos dos fármacos , Difosfonatos/administração & dosagem , Azeite de Oliva/química , Alendronato/administração & dosagem , Fenômenos Biomecânicos , Ratos Wistar

RESUMO

Estudios previos han demostrado que los bisfosfonatos son potentes inhibidores de la resorción ósea. El aceite de oliva (O) es rico en ácidos grasos monoinsaturados con potentes propiedades anti-oxidantes. El objetivo de este estudio fue estudiar el efecto del tratamiento de alendronato (AL) y pamidronato (PA) y de O sobre la regeneración tisular. Las fórmulas se dosificaron 0,5 mg/kg de peso para AL, y de 0,6 mg/kg de peso para PA. El O se administró en la dieta, 50 g/ Kg. Cincuenta y cuatro ratas macho de la línea Wistar se dividieron en 6 grupos. El grupo control (C), recibió semanalmente 0,3 ml/100g de peso corporal de solución salina vía subcutánea. El grupo (AL) recibió semanalmente por vía subcutánea en el miembro posterior izquierdo. El grupo (PA) se colocó igual que el grupo anterior. El grupo (O) fue tratado en la alimentación y en las áreas de la cirugía recibieron inyección subcutánea con solución fisiológica. El grupo (ALO) recibió tratamiento combinado con AL y O. El grupo (PAO) se trató igual al anterior. La cirugía consistió en una incisión longitudinal en las tibias realizando un defecto circular en la parte plana de cada tibia hasta llegar al hueso medular. Se tomaron radiografías a los 0, 7, 15, 30, 60 y 90 días y fueron analizadas con el Software Image Pro Plus. Los estudios estadísticos se realizaron a través del análisis de la variancia a dos y tres criterios de clasificación. Se evidencio un incremento en la densidad mineral ósea promedio (DMO) conforme avanza el tiempo en todos los grupos, siendo evidentes con PA a los 60 días. El tratamiento O mostró eficacia en la remodelación ósea, observándose un pico a los 60 días. Esto sugiere que O representa una opción terapéutica para el tratamiento de las patologías óseas.

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Previous studies have shown that bisphosphonates are potent inhibitors of bone resorption. Olive oil (O) is rich in monounsaturated fatty acids with potent anti-oxidant properties. The objective of this work was to study the effect of alendronate treatment (AL) and pamidronate (PA) and O on tissue regeneration. Formulas 0.5 mg / kg for AL dosed, and 0.6 mg / kg for PA. O was administered in the diet, 50 g / kg. Fifty-four male rats Wistar were divided into 6 groups. The control group (C) received weekly 0.3 ml / 100g body weight of saline subcutaneously. The group (AL) received a weekly dose subcutaneously in the left posterior limb. The group (PA) was placed as the previous group. The group (O) was treated in food and in the areas of surgery received subcutaneousinjection with saline. The group (ALO) received combined treatment with Al and O. The group (PAO) was treated the same as before. Surgery consisted of a longitudinal incision in the warm using a circular on the flat side of each tibia until the medullary bone defect. X-rays at 0, 7, 15, 30, 60 and 90 days were taken and analyzed with Image Pro Plus Software. Statistical studies were conducted through analysis of variance to two and three classification criteria. Results: an increase in the average bone mineral density (BMD) was evident as time progresses in all groups, with PA still evident at 60 days. Or treatment showed efficacy in bone remodeling observed a peak at 60 days. Conclusions: This suggests that O represents a therapeutic option for the treatment of bone disease.

Assuntos

Animais , Masculino , Ratos , Remodelação Óssea/efeitos dos fármacos , Difosfonatos/farmacologia , Azeite de Oliva/química , Tíbia/diagnóstico por imagem , Alendronato/farmacologia , Análise de Variância , Implantes Dentários , Radiografia , Ratos Wistar , Fatores de Tempo

RESUMO

The hypothalamic release of glutamate and GABA regulates neurosecretory functions that may control the onset of puberty. This release may be influenced by neurosteroids such as allopregnanolone. Using superfusion experiments we examined the role of allopregnanolone on the K(+)-evoked and basal [(3)H]-glutamate and [(3)H]-GABA release from mediobasal hypothalamus and anterior preoptic area in prepubertal, vaginal opening and pubertal (P) rats and evaluated its modulatory effect on GABAA and NMDA (N-methyl-d-aspartic acid) receptors. Also, we examined the hypothalamic activity and mRNA expression of 3α-hydroxysteroid oxidoreductase (3α-HSOR) - enzyme that synthesizes allopregnanolone - using a spectrophotometric method and RT-PCR, respectively. Allopregnanolone increased both the K(+)-evoked [(3)H]-glutamate and [(3)H]-GABA release in P rats, being the former effect mediated by the modulation of NMDA receptors - as was reverted by Mg(2+) and by the NMDA receptor antagonist AP-7 and the latter by the modulation of NMDA and GABAA receptors - as was reverted by Mg(2+) and the GABAA receptor antagonist bicuculline. The neurosteroid also increased the basal release of [(3)H]-glutamate in VO rats in an effect that was dependent on the modulation of NMDA receptors as was reverted by Mg(2+). On the other hand we show that allopregnanolone reduced the basal release of [(3)H]-GABA in P rats although we cannot elucidate the precise mechanism by which the neurosteroid exerted this latter effect. The enzymatic activity and the mRNA expression of 3α-HSOR were both increased in P rats regarding the other two studied stages of sexual development. These results suggest an important physiological function of allopregnanolone in the hypothalamus of the P rat where it might be involved in the 'fine tuning' of neurosecretory functions related to the biology of reproduction of the female rats.

Assuntos

3-alfa-Hidroxiesteroide Desidrogenase (B-Específica)/biossíntese , Ácido Glutâmico/metabolismo , Hipotálamo/metabolismo , Pregnanolona/metabolismo , Maturidade Sexual/fisiologia , Ácido gama-Aminobutírico/metabolismo , Animais , Feminino , Neurotransmissores/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa

RESUMO

INTRODUCTION: Adenosine A2A and A2B receptor intracellular pathway is associated with either increasing endothelial nitric oxide (NO) synthase (eNOS) expression or eNOS activation (i.e., tyrosine 1177 phosphorylation); a mechanism linked to pro or anti-proliferative effects depending of the cell type. However, there are no reports in pre-eclampsia. OBJECTIVES: Investigate whether NO signaling pathway is involved in fetal endothelium proliferation induced by adenosine receptor activation in early and late-onset pre-eclampsia. METHODS: Human umbilical vein endothelial cells (HUVEC) were isolated from normal (n=25), late-onset pre-eclampsia (n=11) and early-onset pre-eclampsia (n=22). Adenosine A2A and A2B expression was evaluated by immunocytochemistry and Western blot. Cell proliferation was analyzed using MTS-assay in absence or presence of non-selective adenosine receptor agonist (NECA 10µM), adenosine A2A receptor selective agonist (CGS-21680, 100nM), and/or the antagonists ZM-241385 (0-100µM) or MRS-1754 (0-1µM) for A2A and A2B receptors during 24h. In parallel experiments NOS inhibitor (L-NAME, 100µM) was used in co-incubation by either adenosine receptor agonist or antagonists. Nitrite concentration in the culture medium and protein nitration assessed by Western blot were measured in cells exposed to CGS-21680 (30min). RESULTS: Early-onset pre-eclampsia was associated to low A2A (∼70%), but high (∼2-fold) A2B adenosine receptor protein abundance compared with normal or late-onset pre-eclampsia. Basally, HUVEC from early-onset showed a low (∼42%), whereas late-onset exhibited high proliferation (∼1.5-fold) compared with normal pregnancy. Cell proliferation was increased by CGS-21680 (∼2-fold) in late-onset or normal pregnancy and ∼5-fold in early-onset pre-eclampsia compared with respective control. NECA increased cell proliferation only in normal cells. Stimulatory effect of CGS-21680, was inhibited by ZM-241385 in normal pregnancies (Ki, 25nM) and late-onset (Ki 50nM) but not in early-onset (Ki ambiguous). Interestingly, MRS-1754 showed an increase in cell proliferation in a dose-response manner only in early-onset group. L-NAME partially blocked (∼25%) the stimulatory effect of CGS-21680 in late-onset and normal pregnancy. Interestingly, L-NAME revert the maximal stimulatory effect of MRS-1754 observed in early-onset. Total and phosphorylated eNOS protein was reduced (∼50%) in early-onset pre-eclampsia compared to late-onset or normal pregnancy. In turn, cells from late-onset pre-eclampsia exhibited high (∼2-fold) eNOS phosphorylation compared with normal pregnancy. In normal pregnancy, CGS-21680 (30min) increased (∼2-fold) the eNOS phosphorylation and nitrotyrosine formation, without changes in nitrite levels, but non-significant changes were observed in early or late-onset pre-eclamptic cells. CONCLUSION: Fetal endothelium from early-onset exhibits a predominant anti-proliferative effect mediated by adenosine A2B receptors activation, whereas the stimulatory effect of adenosine A2A receptors prevails in cells from late-onset pre-eclampsia. Both pro and anti-proliferative effects seem mediated by a nitric oxide-depended intracellular pathway. Supported by FONDECYT 1100684, Conicyt Anillo ACT73.

RESUMO

INTRODUCTION: Elevated uric acid levels during the first or third trimester of gestation have been associated with poor perinatal outcomes in women with hypertensive pregnancies. OBJECTIVES: Investigate whether uric acid levels are related to adverse perinatal outcomes in Chilean hypertensive women. METHODS: It is a post-hoc analysis from a retrospective study including clinical records (n=416) of women with diagnosis of hypertension in pregnancy treated in the Hospital Clínico Herminda Martin, Chillán, Chile. From these records, 86 showed quantification of uric acid plasma levels at the moment of hypertension diagnosis ((3) 140/90mmHg; at 34±5weeks). Women were divided into three groups, considering uric acid levels below 25th percentile (Low group, n=27, <3.7mg/dl), from 25th to 75th percentile (Middle group, n=38, 3.8 to 5.7mg/dl) and above 75th percentile (High group, n=21, >5.8mg/dl) for the studied population. RESULTS: In the entire group of hypertensive women, the uric acid/creatinine ratio was positively related to hospitalization days (p=0.04), and negatively associated with newborn weight (p=0.02) and size (p=0.01). ANOVA analysis did not show statistical differences in age, parity, systolic, diastolic or media blood pressure, body mass index, proteinuria, hepatic enzymes or hypoxia perinatal in women with low, middle or high uric acid levels. However, women with high uric acid levels showed a longer-hospitalization period (∼1.2days more), less platelet count (∼40×10(3)/ml) and high creatinine plasma levels (∼0.2mg/dl) and their babies showed less birth weight (∼800g) and were smaller (∼3cm) compared with women with low uric acid levels. Relative risk of intrauterine growth restriction in women with high levels of uric acid was 1.3 (CI, 0.96 to 1.73) compared with women with low levels. CONCLUSION: These data reinforce the general agreement about the utility of hyperuricemia in the prognosis of adverse perinatal outcomes in hypertensive pregnancies.

RESUMO

Workshops are an important part of the IFPA annual meeting. At IFPA Meeting 2010 there were twelve themed workshops, six of which are summarized in this report. 1. The immunology workshop focused on normal and pathological functions of the maternal immune system in pregnancy. 2. The transport workshop dealt with regulation of ion and water transport across the syncytiotrophoblast of human placenta. 3. The epigenetics workshop covered DNA methylation and its potential role in regulating gene expression in placental development and disease. 4. The vascular reactivity workshop concentrated on methodological approaches used to study placental vascular function. 5. The workshop on epitheliochorial placentation covered current advances from in vivo and in vitro studies of different domestic species. 6. The proteomics workshop focused on a variety of techniques and procedures necessary for proteomic analysis and how they may be implemented for placental research.

Assuntos

Feto/fisiologia , Placenta/fisiologia , Trofoblastos/fisiologia , Animais , Educação , Epigênese Genética/fisiologia , Feminino , Feto/irrigação sanguínea , Feto/citologia , Feto/imunologia , Humanos , Transporte de Íons/fisiologia , Troca Materno-Fetal/fisiologia , Placenta/irrigação sanguínea , Placenta/citologia , Placenta/imunologia , Placentação/fisiologia , Gravidez , Proteômica/métodos , Trofoblastos/citologia , Trofoblastos/imunologia

RESUMO

La biopsia hepática sigue siendo importante en el diagnóstico de enfermedades del hígado, apareciendo las complicaciones del procedimiento dentro de las primeras horas, siendo necesario 4-6 horas de observación para su realización. Objetivos: Presentar nuestra casuística y protocolo de 23 casos de biopsia hepática percutánea en régimen ambulatorio. Materiales y Métodos: Revisión de fichas clínicas de pacientes a los que se les realizó el procedimiento. Se analizaron variables demográficas, exámenes de laboratorio, razón de indicación de biopsia y complicaciones mayores y menores durante fase hospitalaria y ambulatoria. Resultados: La edad promedio fue de 53,2 años. 69,56 por ciento eran mujeres y 30,4 por ciento hombres. El menor recuento plaquetario fue de 105.000 x mm3. No se observaron complicaciones mayores, y las menores ocurrieron en 91 por ciento en el período de observación y el 61 por ciento de ellas en las primeras dos horas. Conclusiones: Para la realización de biopsia hepática en pacientes ambulatorios, un período de observación hospitalaria de 5 horas parece ser suficiente, dado que en éste se pesquisan la mayoría de las complicaciones de una población bien seleccionada, permitiendo plantear la realización de este procedimiento en forma ambulatoria en nuestro país.

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Hepatic biopsy is important in the diagnosis of hepatic diseases. The potential complications may appear in the first hours after the procedure, therefore it is necessary to consider a period of 4-6 hours of observation. Objectives: To present our protocol and 23 cases of percutaneous liver biopsies in ambulatory regime. Materials and Methods: Review of case histories (case report forms) of the patients that were subjected to the procedure. Demographic variables, laboratory tests, reasons for biopsy, and major and minor complications during hospitalization and ambulatory phase. Results: Average age was 53.2 years; of these, 69.56 percent were women and 30.4 percent men. The lowest plaquetary count was 105.000 x mm3. No major complications were observed, and some of them occurred in a 91 percent during the observation period, and 61 percent during the first two hours. Conclusions: A period of clinical observation of 5 hours seems enough for a biopsy in ambulatory patients. It is during this period when the majority of complications are observed in a well-selected population. This supports the idea of performing this procedure in an ambulatory or outpatient basis on our country.

Assuntos

Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Biópsia/efeitos adversos , Hepatopatias/patologia , Procedimentos Cirúrgicos Ambulatórios , Biópsia/métodos , Chile , Estudos de Viabilidade , Protocolos Clínicos , Seleção de Pacientes

RESUMO

Up regulation of the transforming growth factor-beta 1 (TGF-beta1) axis has been recognized as a pathogenic event for progression of glomerulosclerosis in diabetic nephropathy. We demonstrate that glomeruli isolated from diabetic rats accumulate up to sixfold more extracellular adenosine than normal rats. Both decreased nucleoside uptake activity by the equilibrative nucleoside transporter 1 and increased AMP hydrolysis contribute to raise extracellular adenosine. Ex vivo assays indicate that activation of the low affinity adenosine A2B receptor subtype (A2BAR) mediates TGF-beta1 release from glomeruli of diabetic rats, a pathogenic event that could support progression of glomerulopathy when the bioavailability of adenosine is increased.

Assuntos

Adenosina/metabolismo , Nefropatias Diabéticas/metabolismo , Glomérulos Renais/metabolismo , Receptor A2B de Adenosina/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Monofosfato de Adenosina/metabolismo , Animais , Disponibilidade Biológica , Transportador Equilibrativo 1 de Nucleosídeo/metabolismo , Hidrólise , Masculino , Ratos , Ratos Sprague-Dawley

RESUMO

Intrauterine growth restriction (IUGR) is associated with chronic fetal hypoxia, altered placental vasodilatation and reduced endothelial nitric oxide synthase (eNOS) activity. In human umbilical vein endothelial cells (HUVEC) from pregnancies complicated with IUGR (IUGR cells) and in HUVEC from normal pregnancies (normal cells) cultured under hypoxia l-arginine transport is reduced; however, the mechanisms leading to this dysfunction are unknown. We studied hypoxia effect on l-arginine transport and human cationic amino acid transporters 1 (hCAT-1) expression, and the potential NO and protein kinase C alpha (PKCalpha) involvement. Normal or IUGR HUVEC monolayers were exposed (0-24h) to 5% O(2) (normoxia), and 1 or 2% O(2) (hypoxia). l-Arginine transport and hCAT-1 expression, phosphorylated and total PKCalpha or eNOS protein and mRNA expression were quantified. eNOS involvement was tested using a siRNA against eNOS (eNOS-siRNA) adenovirus. IUGR cells in normoxia or hypoxia, and normal cells in hypoxia exhibited reduced l-arginine transport, hCAT-1 expression, NO synthesis and eNOS phosphorylation at Serine(1177), effects reversed by calphostin C (PKC inhibitor) and S-nitroso-N-acetyl-l,d-penicillamine (SNAP, NO donor). However, N(G)-nitro-l-arginine methyl ester (l-NAME, NOS inhibitor) reduced hCAT-1 expression only in normal cells in normoxia. Increased Thr(638)-phosphorylated PKCalpha was exhibited by IUGR cells in normoxia or hypoxia and normal cells in hypoxia. The effects of hypoxia in normal cells were mimicked in eNOS-siRNA transduced cells; however, IUGR phenotype was unaltered by eNOS knockdown. Thus, IUGR- and hypoxia-reduced l-arginine transport could result from increased PKCalpha, but reduced eNOS activity leading to a lower hCAT-1 expression in HUVEC. In addition, IUGR endothelial cells are either not responsive or maximally affected by hypoxia. These mechanisms could be responsible for placental dysfunction in diseases where fetal endothelium is chronically exposed to hypoxia, such as IUGR.

Assuntos

Arginina/metabolismo , Células Endoteliais/enzimologia , Retardo do Crescimento Fetal/metabolismo , Hipóxia/metabolismo , Óxido Nítrico/biossíntese , Veias Umbilicais/citologia , Adulto , Transportador 1 de Aminoácidos Catiônicos/genética , Transportador 1 de Aminoácidos Catiônicos/metabolismo , Células Cultivadas , Células Endoteliais/citologia , Feminino , Humanos , Modelos Biológicos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Fosforilação/fisiologia , Gravidez , Proteína Quinase C-alfa/genética , Proteína Quinase C-alfa/metabolismo , RNA Mensageiro/metabolismo , Vasodilatação/fisiologia , Adulto Jovem

RESUMO

Pre-eclampsia is associated with elevated maternal blood pressure and proteinuria, altered fetal growth, and increased plasma adenosine concentration in the mother and the fetus. Human equilibrative nucleoside transporters 1 (hENT1) and hENT2 are crucial to maintain physiological plasma levels of adenosine, thus modulating its several biological effects through adenosine receptor activation. However, it is unknown whether hENTs and adenosine receptors are expressed in human placental microvascular endothelium (hPMEC). To assay whether the increased fetal plasma adenosine concentration in pre-eclampsia results from altered hENT-mediated transport, and the potential involvement of adenosine receptors in this phenomenon, we investigated hENTs and A2A and A2B adenosine receptors expression and function in hPMEC. Cells were isolated and cultured from normal pregnancies (n=17) or pre-eclampsia with adequate-for-gestational age fetuses (n=7). hENT1, hENT2, A2A and A2B adenosine receptors were expressed and functional in hPMEC. Extracellular adenosine concentration was higher (4-fold) in pre-eclampsia versus normal pregnancies. hPMEC from pre-eclampsia exhibit increased total transport (hENT1+hENT2), and maximal velocity (Vmax) for hENT2- (2-fold), but reduced Vmax for hENT1-mediated adenosine transport (75%), with no changes in apparent Km. hENT2 expression was increased (4.5-fold), but hENT1 protein abundance was reduced (80%) in pre-eclampsia. Equally, A2A expression was reduced (50-80%) in pre-eclampsia. CGS-21680 (A2A agonist) did not alter hENTs expression or activity, but ZM-241385 (A2A antagonist) blocked pre-eclampsia effects and increased hENT1-mediated transport in normal pregnancies. Thus, A2B adenosine receptors may differentially modulate hENTs in hPMEC, which could be a mechanism attempting to re-establish physiological extracellular adenosine levels in pre-eclampsia.

Assuntos

Células Endoteliais/fisiologia , Transportador Equilibrativo 1 de Nucleosídeo/biossíntese , Transportador Equilibrativo 2 de Nucleosídeo/biossíntese , Placenta/citologia , Pré-Eclâmpsia/fisiopatologia , Receptor A2B de Adenosina/fisiologia , Adenosina/análogos & derivados , Adenosina/metabolismo , Adenosina/farmacologia , Agonistas do Receptor A2 de Adenosina , Antagonistas do Receptor A2 de Adenosina , Adulto , Transportador Equilibrativo 1 de Nucleosídeo/fisiologia , Transportador Equilibrativo 2 de Nucleosídeo/fisiologia , Feminino , Regulação da Expressão Gênica , Humanos , Fenetilaminas/farmacologia , Gravidez , Receptor A2A de Adenosina/biossíntese , Triazinas/farmacologia , Triazóis/farmacologia

RESUMO

Preeclampsia is a human syndrome characterized by elevated maternal blood pressure and proteinuria. It is the main cause of maternal morbidity and mortality, and fetal metabolic disturbances in developed and developing countries. Fetal complications in preeclampsia have been related with lower placental blood flow. The placenta lacks of innervation, thus vascular tone regulation depends on endothelial release of vasoactive molecules such as adenosine and nitric oxide (NO). Information about NO synthesis and its action in the feto-placental vasculature in preeclamptic pregnancies is controversial mainly due to the use of different methodological approaches, severity of the disease and cell type that had been analyzed. A high plasma level of adenosine has been reported in umbilical vein from preeclampsia compared with normal pregnancies. Since this nucleoside is mainly involved in the regulation of vascular tone and angiogenesis, perhaps through the modulation of potassium channels, it is suggested that it would be involved in the maintenance of normal feto-placental function. In this review we hypothesize a potential adenosine-mediated, NO-dependent mechanism accounting for the feto-placental reduced blood flow exhibited in preeclampsia. We summarize the potential mechanisms involved in the modulation of inducible NO synthase expression and activity in preeclampsia, emphasizing metabolic alterations in the placenta microvascular endothelial function. The involvement of adenosine, nucleoside membrane transporters and adenosine receptors, nuclear factor kappa B (NF-kappaB), potassium channels and angiogenesis, are also discussed regarding abnormal endothelial function in preeclampsia.

Assuntos

Adenosina/metabolismo , Endotélio Vascular/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Placenta/irrigação sanguínea , Pré-Eclâmpsia/metabolismo , Arginina/metabolismo , Feminino , Humanos , Modelos Biológicos , NF-kappa B/fisiologia , Neovascularização Fisiológica/fisiologia , Placenta/metabolismo , Gravidez , Transdução de Sinais/fisiologia

Assuntos

Óxido Nítrico Sintase/metabolismo , Óxido Nítrico/metabolismo , Pré-Eclâmpsia/enzimologia , Resultado da Gravidez , Adolescente , Adulto , Biomarcadores/análise , Estudos de Casos e Controles , Feminino , Idade Gestacional , Humanos , Idade Materna , Óxido Nítrico/análise , Óxido Nítrico Sintase/análise , Paridade , Pré-Eclâmpsia/diagnóstico , Valor Preditivo dos Testes , Gravidez , Valores de Referência , Sensibilidade e Especificidade

Assuntos

Proteína C-Reativa/análise , Pré-Eclâmpsia/sangue , Gravidez/sangue , Adulto , Feminino , Seguimentos , Humanos , Estudos Prospectivos

RESUMO

Euthycarcinoids are one of the most enigmatic arthropod groups, having been assigned to nearly all major clades of Arthropoda. Recent work has endorsed closest relationships with crustaceans or a myriapod-hexapod assemblage, a basal position in the Euarthropoda, or a placement in the Hexapoda or hexapod stem group. Euthycarcinoids are known from 13 species ranging in age from Late Ordovician or Early Silurian to Middle Triassic, all in freshwater or brackish water environments. Here we describe a euthycarcinoid from marine strata in Argentina dating from the latest Cambrian period, extending the group's record back as much as 50 million years. Despite its antiquity and marine occurrence, the Cambrian species demonstrates that morphological details were conserved in the transition to fresh water. Trackways in the same unit as the euthycarcinoid strengthen arguments that similar traces of subaerial origin from Cambro-Ordovician rocks were made by euthycarcinoids. Large mandibles in euthycarcinoids are confirmed by the Cambrian species. A morphology-based phylogeny resolves euthycarcinoids as stem-group Mandibulata, sister to the Myriapoda and Crustacea plus Hexapoda.

Assuntos

Artrópodes/anatomia & histologia , Artrópodes/classificação , Fósseis , Filogenia , Abdome/anatomia & histologia , Animais , Argentina , Artrópodes/fisiologia , Água Doce , Mandíbula/anatomia & histologia , Fatores de Tempo

RESUMO

The chemical composition of green seaweed, Monostroma undulatum, Wittrock, growing in the Southern Argentina coast, was studied. Samples were collected in Puerto Deseado, province of Santa Cruz (47 degrees 45'L.S., 65 degrees 55'L.W.), from October to December 1999 and 2000. It has been analyzed six sample during this period. Algae were washed with sea water and dried at room temperature for 24 hs. Moisture, nitrogen, lipids and ashes were determined according to AOAC; fiber (total, soluble and insoluble), according to Lahaye. After mineralization with nitric acid, sodium and potassium were determined by flame photometry, calcium by complexometric method, and phosphorus by Gomori's method. The ranges expressed per 100 g dry algae were: protein (Nx6.25): 12.89-21.85; ashes (g): 33.92-40.05; lipid (g): 0.32-1.47; total fiber (g): 14.36-19.6; digestible carbohydrates (calculated by difference) (g): 20.86-32.48; sodium (g): 7.39-13.11; potassium (g): 1.38-3.18; calcium (mg): 149-226; phosphorus (mg): 190-447; Vitamin C (mg): 159-455. These results show that this green seaweed is an important source for protein, fiber, macronutrients minerals and vitamin C, during the macroscopic period. There was an important fluctuation that must be taken into account to consider the commercial collection to use it in human nutrition.

Assuntos

Humanos , Ácido Ascórbico/análise , Alga Marinha/química , Clorófitas/química , Minerais/análise , Argentina , Fibras na Dieta/análise , Necessidades Nutricionais , Valor Nutritivo , Estações do Ano

RESUMO

OBJECTIVE: To investigate the concentration of markers of inflammation in non-pregnant women, women with normal pregnancy and women with pre-eclampsia. METHODS: Pregnant women (n=26), women with pre-eclampsia (n=25) and non-pregnant normotensive women (n=21) were included in the study. C-reactive protein was measured by latex-enhanced immunoturbidimetric assay, serum tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) by high sensitivity ELISA. Kruskal-Wallis non-parametric analysis of variance followed by the Mann-Whitney U-test were used for statistical analyses. RESULTS: Higher values (mean+/-S.E.M.) of C-reactive protein were found in pre-eclampsia (4.11+/-0.37 mg/dl) compared with normal pregnant women (2.49+/-0.26 mg/dl) and non-pregnant controls (1.33+/-0.15 mg/dl). TNF-alpha was significantly higher in women with pre-eclampsia (15.74+/-5.09 pg/ml), in relation to the control group (2.76+/-0.41 pg/ml) and women with normal pregnancy (8.31+/-1.55 pg/ml). IL-6 levels were significantly higher in pre-eclamptic women (12.91+/-1.29 pg/ml) compared with normal pregnant (5.07+/-0.423 pg/ml) and control women (1.25+/-0.13 pg/ml). CONCLUSIONS: The results of this cross-sectional study in a high-risk Andean population show that both C-reactive protein and pro-inflammatory cytokines are present in higher concentrations in women with pre-eclampsia. The study was undertaken in women with established pre-eclampsia and it is not possible to determine whether the increased concentrations of C-reactive protein and pro-inflammatory cytokines were a cause or consequence of the disease.

Assuntos

Proteína C-Reativa/análise , Interleucina-6/sangue , Pré-Eclâmpsia/sangue , Fator de Necrose Tumoral alfa/análise , Adulto , Análise de Variância , Pressão Sanguínea , Estudos Transversais , Equador , Ensaio de Imunoadsorção Enzimática , Feminino , Idade Gestacional , Humanos , Contagem de Leucócitos , Paridade , Gravidez