Comparison of Human and Experimental Pulmonary Veno-Occlusive Disease.

Pulmonary veno-occlusive disease (PVOD) occurs in humans either as a heritable form (hPVOD) due to biallelic inactivating mutations of EIF2AK4 (encoding GCN2) or as a sporadic form in older age (sPVOD). The chemotherapeutic agent mitomycin C (MMC) is a potent inducer of PVOD in humans and in rats (MMC-PVOD). Here, we compared human hPVOD and sPVOD, and MMC-PVOD pathophysiology at the histological, cellular, and molecular levels to unravel common altered pathomechanisms. MMC exposure in rats was associated primarily with arterial and microvessel remodeling, and secondarily by venous remodeling, when PVOD became symptomatic. In all forms of PVOD tested, there was convergent GCN2-dependent but eIF2α-independent pulmonary protein overexpression of HO-1 (heme oxygenase 1) and CHOP (CCAAT-enhancer-binding protein [C/EBP] homologous protein), two downstream effectors of GCN2 signaling and endoplasmic reticulum stress. In human PVOD samples, CHOP immunohistochemical staining mainly labeled endothelial cells in remodeled veins and arteries. Strong HO-1 staining was observed only within capillary hemangiomatosis foci, where intense microvascular proliferation occurs. HO-1 and CHOP stainings were not observed in control and pulmonary arterial hypertension lung tissues, supporting the specificity for CHOP and HO-1 involvement in PVOD pathobiology. In vivo loss of GCN2 (EIF2AK4 mutations carriers and Eif2ak4-/- rats) or in vitro GCN2 inhibition in cultured pulmonary artery endothelial cells using pharmacological and siRNA approaches demonstrated that GCN2 loss of function negatively regulates BMP (bone morphogenetic protein)-dependent SMAD1/5/9 signaling. Exogenous BMP9 was still able to reverse GCN2 inhibition-induced proliferation of pulmonary artery endothelial cells. In conclusion, we identified CHOP and HO-1 inhibition, and BMP9, as potential therapeutic options for PVOD.

NMDA-Type Glutamate Receptor Activation Promotes Vascular Remodeling and Pulmonary Arterial Hypertension.

BACKGROUND: Excessive proliferation and apoptosis resistance in pulmonary vascular cells underlie vascular remodeling in pulmonary arterial hypertension (PAH). Specific treatments for PAH exist, mostly targeting endothelial dysfunction, but high pulmonary arterial pressure still causes heart failure and death. Pulmonary vascular remodeling may be driven by metabolic reprogramming of vascular cells to increase glutaminolysis and glutamate production. The N-methyl-d-aspartate receptor (NMDAR), a major neuronal glutamate receptor, is also expressed on vascular cells, but its role in PAH is unknown. METHODS: We assessed the status of the glutamate-NMDAR axis in the pulmonary arteries of patients with PAH and controls through mass spectrometry imaging, Western blotting, and immunohistochemistry. We measured the glutamate release from cultured pulmonary vascular cells using enzymatic assays and analyzed NMDAR regulation/phosphorylation through Western blot experiments. The effect of NMDAR blockade on human pulmonary arterial smooth muscle cell proliferation was determined using a BrdU incorporation assay. We assessed the role of NMDARs in vascular remodeling associated to pulmonary hypertension, in both smooth muscle-specific NMDAR knockout mice exposed to chronic hypoxia and the monocrotaline rat model of pulmonary hypertension using NMDAR blockers. RESULTS: We report glutamate accumulation, upregulation of the NMDAR, and NMDAR engagement reflected by increases in GluN1-subunit phosphorylation in the pulmonary arteries of human patients with PAH. Kv channel inhibition and type A-selective endothelin receptor activation amplified calcium-dependent glutamate release from human pulmonary arterial smooth muscle cell, and type A-selective endothelin receptor and platelet-derived growth factor receptor activation led to NMDAR engagement, highlighting crosstalk between the glutamate-NMDAR axis and major PAH-associated pathways. The platelet-derived growth factor-BB-induced proliferation of human pulmonary arterial smooth muscle cells involved NMDAR activation and phosphorylated GluN1 subunit localization to cell-cell contacts, consistent with glutamatergic communication between proliferating human pulmonary arterial smooth muscle cells via NMDARs. Smooth-muscle NMDAR deficiency in mice attenuated the vascular remodeling triggered by chronic hypoxia, highlighting the role of vascular NMDARs in pulmonary hypertension. Pharmacological NMDAR blockade in the monocrotaline rat model of pulmonary hypertension had beneficial effects on cardiac and vascular remodeling, decreasing endothelial dysfunction, cell proliferation, and apoptosis resistance while disrupting the glutamate-NMDAR pathway in pulmonary arteries. CONCLUSIONS: These results reveal a dysregulation of the glutamate-NMDAR axis in the pulmonary arteries of patients with PAH and identify vascular NMDARs as targets for antiremodeling treatments in PAH.

Functional interaction between PDGFß and GluN2B-containing NMDA receptors in smooth muscle cell proliferation and migration in pulmonary arterial hypertension.

In this study, we explored the complex interactions between platelet-derived growth factor (PDGF) and N-methyl-d-aspartate receptor (NMDAR) and their effect on the excessive proliferation and migration of smooth muscle cells leading to obstructed arteries in pulmonary arterial hypertension (PAH). We report lower expression of glutamate receptor NMDA-type subunit 2B (GluN2B), a subunit composing NMDARs expected to affect cell survival/proliferation of pulmonary artery smooth muscle cells (PASMCs), in PAH patient lungs. PASMC exposure to PDGF-BB stimulated immediate increased levels of phosphorylated Src family kinases (SFKs) together with increased phosphorylated GluN2B (its active form) and cell surface relocalization, suggesting a cross talk between PDGFR-recruited SFKs and NMDAR. Selective inhibition of PDGFR-ß or SFKs with imatinib or A-419259, respectively, on one hand, or with specific small-interfering RNAs (siRNAs) on the other hand, aborted PDGF-induced phosphorylation of GluN2B, thus validating the pathway. Selective inhibition of GluN2B using Rö25-6981 and silencing with specific siRNA, in the presence of PDGF-BB, significantly increased both migration and proliferation of PASMCs, thus strengthening the functional importance of the pathway. Together, these results indicate that GluN2B-type NMDAR activation may confer to PASMCs antiproliferative and antimigratory properties. The decreased levels of GluN2B observed in PAH pulmonary arteries could mediate the excessive proliferation of PASMCs, thus contributing to medial hyperplasia and PAH development.

Handgrip Dynamometry and Patient-Generated Subjective Global Assessment in Patients with Nonresectable Lung Cancer.

INTRODUCTION: Undernutrition is frequently associated with advanced lung cancer. Accurate nutritional assessment tools are important to provide the proper nutritional therapy. Handgrip dynamometry has already been used in these patients, and the findings suggest that it is a good indicator of nutritional status. AIMS: The aim of this study was to evaluate the association between nutritional status and handgrip strength (HGS) in patients with nonresectable lung cancer. METHODS: Cross-sectional study involving thirty-seven subjects with nonresectable lung cancer. Nutritional status was obtained using Patient Generated Subjective Global Assessment (PG-SGA), and muscle function was evaluated by HGS using a Jamar® handgrip dynamometer on the nondominant hand. The results of both methods were compared and correlated. RESULTS: According to PG-SGA, 73% (n = 27) of the patients were moderately undernourished, and 8% (n = 3) were severely undernourished. In total, 81% (n = 30) were undernourished. HGS was below the 50th percentile in 57% of the patients (n = 21). We found a significant association between nutritional status according to PG-SGA and HGS (P = 0.026, CI = 95%). CONCLUSIONS: Handgrip dynamometry can be a useful tool to evaluate the functional and nutritional status. It can be included in lung cancer patients evaluation, along with other nutritional assessment tools.

Catheter Reprocessing for Coronary Angiography: It is Not Safe.

BACKGROUND: Coronary angiography and percutaneous coronary intervention are frequently and increasingly performed worldwide. Although catheters for coronary angiography are considered as single-use devices, some people still question this decision. This study evaluated the structural characteristics and thermal stability of new and reprocessed catheters. METHODS: Five catheters (Judkins left) of the same brand and manufacturer were selected for each analysis. We evaluated: new catheters, catheters reprocessed once (first), twice (second), thrice (third), and seven times (seventh). The optical analyses of the proximal, middle and distal parts of the catheters were performed by magnifying glass. Besides, thermogravimetric analyses were done. RESULTS: After reprocessing, the crushing, color changes, folds, dents, deformations, and lumen narrowing were observed; the stainless-steel framework, the external tortuosity, the interlaced mesh of stainless-steel wires and loss of polymeric material were visualized. Thermogravimetric analysis showed lost of mass of the catheters. CONCLUSIONS: This study demonstrated that the structural integrity and mass of catheters are lost with reprocessing. These findings may be caused by several steps of reprocessing; however, regardless of which step or steps were responsible, the presence of structural integrity loss leads to the recommendation of not reusing this type of device.

Trichloroethylene increases pulmonary endothelial permeability: implication for pulmonary veno-occlusive disease.

Trichloroethylene exposure is a major risk factor for pulmonary veno-occlusive disease. We demonstrated that trichloroethylene alters the endothelial barrier integrity, at least in part, through vascular endothelial (VE)-Cadherin internalisation, and suggested that this mechanism may play a role in the development of pulmonary veno-occlusive disease.

Pharmacological assessment of the freezing, antinociception, and exploratory behavior organized in the ventrolateral periaqueductal gray.

Opioid and serotonergic mechanisms of the ventrolateral periaqueductal gray (vlPAG) are recruited by conditioned freezing and antinociception. However, it is unclear whether freezing and antinociception induced by stimulation of the vlPAG are interrelated. To address this issue we looked at the effects of the opioid antagonist naltrexone, the 5-HT2 antagonist ketanserin, and the benzodiazepine agonist midazolam injected into the vlPAG on the freezing and antinociception induced by electrical stimulation of this region. This antinociception was evaluated by the tail-flick and formalin tests. To further characterize the involvement of the vlPAG in unconditioned fear, the effects of intra-vlPAG injections of midazolam on the exploratory behavior were also assessed in independent groups of rats submitted to the elevated plus-maze test (EPM). The data obtained showed that: (i) electrical stimulation of the vlPAG causes freezing blocked by midazolam but not by naltrexone and ketanserin; (ii) antinociception generated at the level of the vlPAG is inhibited by naltrexone, ketanserin, and midazolam; (iii) activation of benzodiazepine-mediated mechanisms in the vlPAG increased the exploratory behavior of rats in the closed arms but not the avoidance behavior of open arms of the EPM. Thus, freezing and antinociception generated in the vlPAG are dissociated pharmacologically. Whereas antinociception is a multimediated process sensitive to naltrexone, ketanserin, and midazolam, the freezing induced by vlPAG stimulation was reversed only by the benzodiazepine compound. As injections of midazolam into the vlPAG do not cause anxiolytic effects in the EPM, the aversive stimuli inherent of this test seem to bypass the vlPAG.

Influência do déficit de atenção e hiperatividade na aprendizagem em escolares / The attention-deficit hyperactivity disorder influence in schooler’s learning

O Transtorno de Déficit de Atenção/Hiperatividade é um distúrbio neurocomportamental com prevalência em crianças e adolescentes, trazendo consequências no aprendizado na fase de aquisição e desenvolvimento, causando dificuldades emocionais e sociais. Fatores ambientais e genéticos estão relacionados ao transtorno e o diagnóstico precoce é uma das formas de tratamento. A questão fundamental que nos leva a estudar este tema está vinculada na prática pedagógica, onde percebemos que existem fatores que podem influenciar e prejudicar o desempenho dos educandos, incluindo diversos problemas tanto de ordem familiar, social e principalmente os que afetam a atenção. Assim, nossos objetivos visam a compreender esse transtorno, identificar os sintomas, causas, e propor estratégias de intervenções, para manejar melhor os conhecimentos e favorecer uma melhor atenção e amparo educacional a essas crianças. Realizamos pesquisas bibliográficas em diversas fontes como: Scientific Electronic Library Online (SciELO), PubMed, entre outras, buscando informações para compreender os diferentes aspectos associados (comportamento e relacionamento da criança hiperativa), possibilitando alternativas para um melhor atendimento na área educacional.

Attention-Deficit Hyperactivity Disorder is a developmental disorder, largely neurological in nature, with prevalence in children and adolescents, which brings consequences in learning, in the cognitive acquisition and development phase, causes emotional and social difficulties. The environmental and genetic factors are directly related to the disorder and so the precocious diagnosis is one way of ADHD treatment. The fundamental subject that leads us to study this theme is linked to the pedagogic practice, where we notice the existence of factors which can influence and harm the students acting, as much as the problems of family, social order and, mainly, the ones that affect the attention. Thereby, our purposes seek to understand this disorder, to identify the symptoms, the causes and consequences, to propose interventions to articulate the knowledge better and to dedicate larger attention and education help to those children. We accomplished bibliographical researches in several sources, such as: Scientific Electronic Library Online (SciELO), PubMed, among others, looking for information to understand the different aspects of the hyperactivity (the behavior and the relationship of the hyperactive child), making possible alternatives for a better service in the education area.