Medical therapies for pulmonary arterial hypertension.

Pulmonary Arterial hypertension (PAH) is a chronic and progressive disease characterized by an increase in pulmonary vascular resistance due to severe remodeling of the small pulmonary arteries. In PAH, the endothelial cells fail to maintain their homeostatic balance, with the consequent impaired production of vasodilators and over-expression of vasoconstrictors and proliferators. Current treatment of PAH is based on the discovery of three main pathways of endothelial dysfunction (prostacyclin, nitric oxide and endothelin-1), and includes drugs such as prostacyclin analogs, phosphodiesterase-5 inhibitors and endothelin receptor antagonists (ERAs). Recently approved drugs that act through these classic pathways include riociguat (cyclic GMP stimulator) and macitentan (a tissue specific dual ERA). However, several new drugs and new pathways are under study. New targeted therapies include tyrosine kinase inhibitors, Rho kinase inhibitors and serotonin receptor blockers. There are now ten drugs approved for the treatment of PAH that, alone or in combination, have changed the natural history of this disease. The new drugs will allow us to further modified the patients' life expectancy and move towards a cure.

Inhibition of glutamate/glutamine cycle in vivo results in decreased benzodiazepine binding and differentially regulated GABAergic subunit expression in the rat brain.

PURPOSE: The astrocytic enzyme glutamine synthetase (GS) is a key regulator of glutamate and γ-aminobutyric acid (GABA) metabolism in the glutamate/glutamine cycle (GGC). Inhibition of GS results in changes of neurotransmitter release and recycling. However, little is known about the influence of GGC on neurotransmitter receptor expression. In the pentylenetetrazole model of epilepsy, GS becomes nitrated and partially inhibited, and we demonstrated alterations of neurotransmitter receptor expression in the same model. Therefore, we hypothesized similar changes of neurotransmitter receptor expression when GS is inhibited in vivo. METHODS: Rats were treated with a single dose (100 mg/kg bodyweight) of l-methionine sulfoximine (MSO), an irreversible inhibitor of GS. We used ³H-receptor autoradiography to measure glutamatergic [α-amino-3-hydroxy-5-methyl-4-isoxazol-propionic acid (AMPA), kainate, N-methyl-D-aspartate (NMDA)], GABAergic (GABA(A) , GABA(B) and GABA(A) -associated benzodiazepine (BZ) binding sites], dopamine D1, and adenosine A1 receptor subtypes. In addition, we performed saturation analysis of BZ binding sites on cerebral membrane homogenates and investigated the expression of GABA(A) α1 and γ2 subunits (which primarily mediate BZ binding) by western blot analysis. RESULTS: We demonstrated a significant reduction of BZ binding in the somatosensory, piriform, and entorhinal cortices and in the amygdala, 24 and 72 h after MSO treatment. Saturation analysis revealed decreased BZ binding (B(max)) on cerebral membrane homogenates 72 h after MSO treatment, without changes in binding site affinity (K(D)). Furthermore, we found differential changes of α1 , γ2 , and phosphorylated γ2 subunits following MSO treatment. CONCLUSION: On the basis of our findings, we conclude that the glutamate/glutamine cycle directly influences GABAergic neurotransmission by regulating GABA(A) subunit composition, thereby affecting its modulation by endogenous benzodiazepines.

Fast, quantitative in situ hybridization of rare mRNAs using 14C-standards and phosphorus imaging.

The use of radiolabelled probes for in situ hybridization (ISH) bears the advantage of high sensitivity and quantifiability. The crucial disadvantages are laborious hybridization protocols, exposition of hybridized sections to film for up to several weeks and the time consuming need to prepare tissue standards with relatively short-lived isotopes like (33)P or (35)S for each experiment. The quantification of rare mRNAs like those encoding for subunits of neurotransmitter receptors is therefore a challenge in ISH. Here, we describe a method for fast, quantitative in situ hybridization (qISH) of mRNAs using (33)P-labelled oligonucleotides together with (14)C-polymer standards (Microscales, Amersham Biosciences) and a phosphorus imaging system (BAS 5000 BioImage Analyzer, Raytest-Fuji). It enables a complete analysis of rare mRNAs by ISH. The preparation of short-lived (33)P-standards for each experiment was replaced by co-exposition and calibration of long-lived (14)C-standards together with (33)P-labelled brain paste standards. The use of a phosphorus imaging system allowed a reduction of exposition time following hybridization from several weeks to a few hours or days. We used this approach as an example for applications to quantify the expression of GluR1 and GluR2 subunit mRNAs of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor in the hippocampus of untreated rats, and after intraperitoneal application of the organo-arsenic compound dimethyl arsenic acid.

Incidencia de nefropatias posterior a preeclampsia grave y eclampsia en el Hospital Primero de Mayo de enero ­ diciembre 2013 / Incidence of nephropathies after severe preeclampsia and eclampsia at the "Primero de Mayo" Hospital from January - December 2013

La preeclampsia-eclampsia representa una de las patologías más frecuentes durante el embarazo y una de las principales causas de morbi-mortalidad materna. Se realizó un estudio descriptivo transversal, el universo estuvo formado por el 100% de las pacientes que consultaron en el Hospital Primero de Mayo con diagnóstico de preeclampsia grave ­ eclampsia sin comorbilidad previa en el año 201l3, esto nos proporcionó un periodo de 3 años para ver la evolución clínica de dichas pacientes. Se revisaron 326 expedientes clínicos de pacientes que presentaron preeclampsia - eclampsia en el año 2013, obteniéndose los datos necesarios para iniciar el estudio, 105 pacientes aceptaron participar y cumplieron criterios de inclusión. Posteriormente se procedió a realizar el análisis de los resultados, en base a pruebas de laboratorio se realizó el cálculo de la CKD EPI (Chronic Kidney Disease Epidemiology), que es una ecuación para estimar el filtrado glomerular que incluye variables como creatinina sérica, edad, sexo y raza, se calculó la tasa de filtración glomerular y se utilizó el programa EXCEL para realizar los gráficos para la interpretación final. La mayoría de pacientes al momento de presentar preeclampsia grave se encontraban entre los 25 a 34 años, no hubo diferencia entre pacientes primigestas y multigestas. Se observó que tres años posteriores a presentar preeclampsia los niveles de creatinina obtenidos fueron desde 0.4mg/dl hasta 0.8mg/dl, tasa de filtración glomerular de hasta 92ml/min. No se evidencio niveles de creatininas mayor o igual a 1mg/dl ni tasa de filtración glomerular menores de 90ml/min (según CKD EPI). Se evidencio microalbuminuria en el 24% de pacientes que es un factor de riesgo para la disminución del filtrado glomerular, posteriormente presentar enfermedad renal crónica y la necesidad de iniciar tratamiento renal sustitutivo en un plazo de 8 a 10 años