Rapid induction of arachidonic acid release by monocyte chemotactic protein-1 and related chemokines. Role of Ca2+ influx, synergism with platelet-activating factor and significance for chemotaxis.

Monocyte Chemotactic Protein-1 (MCP-1), a member of the Cys-Cys branch of the chemokine superfamily, induced a mepacrine- and manoalide-sensitive increase in the release of [3H]arachidonic acid from prelabeled human monocytes and monocytic THP-1 leukemic cells. The effect was rapid (<30 s), reached maximum at optimal chemotactic concentrations, and was completely blocked by pretreatment of monocytes with Bordetella pertussis toxin. A specific antiserum and heat inactivation blocked the induction of arachidonic release by MCP-1. No [3H]arachidonic acid release was observed in the absence of Ca2+ influx (5 mM EGTA or 5 mM Ni2+) or in monocytes loaded with a Ca(2+)-buffering agent. However, using ionophore-permeabilized monocytes and controlled intracellular Ca2+ concentration it was possible to dissociate MCP-1-induced Ca2+ influx from [3H]arachidonic acid release. Thus, the MCP-1-induced increase in [Ca2+]i is necessary but not sufficient for arachidonic acid accumulation. Phospholipase A2 inhibitors (mepacrine, p-bromophenacyl bromide, and manoalide) blocked monocyte polarization and chemotaxis induced by MCP-1. The related Cys-Cys chemokines RANTES and LD78/MIP1 alpha also induced a rapid release of [3H]arachidonic acid, and their chemotactic activity was blocked by phospholipase A2 inhibitors. Brief (5 min) pretreatment of monocytes with platelet-activating factor amplified MCP-1-induced arachidonic acid release and, at MCP-1 suboptimal concentrations, synergized in inducing monocyte migration. Since MCP-1 and platelet-activating factor are induced concomitantly by inflammatory cytokines in monocytes and endothelial cells, we speculate that the observed synergism may have in vivo relevance. The results presented here show that the Cys-Cys chemokines MCP-1, LD78/MIP1 alpha, and RANTES cause rapid release of arachidonic acid in monocytes and that this may be important in inducing monocyte chemotaxis

ANALYSIS OF THE DIGITAL COMPETITION IN THE STUDENTS OF THE DEGREE IN ADMINISTRATIVE INFORMATICS OF THE CU. UAEM. ATLACOMULCO

Determinar la Competencia Digital en los alumnos de la Licenciatura en Informática Administrativa del Centro Universitario Atlacomulco (CUA), perteneciente a la UAEM, debería ser una tarea obligatoria de cada docente en beneficio de la comunidad académica, al aplicar el instrumento se identificaron factores que proporcionan un punto de vista objetivo y ofrece un panorama sobre qué acciones se deberán retomar en beneficio de los discentes. Entre estas destaca el mejoramiento de planes de estudio, una plataforma con la capacidad para cursos online masivos y abiertos (Massive Online Open Courses “MOOC” por sus siglas en inglés), apoyo de docentes con actualizaciones sobre Tecnologías de la Información y la Comunicación (TIC), por mencionar algunos

Mechanisms of endothelial cell dysfunction in cystic fibrosis

Although cystic fibrosis (CF) patients exhibit signs of endothelial perturbation, the functions of the cystic fibrosis conductance regulator (CFTR) in vascular endothelial cells (EC) are poorly defined. We sought to uncover biological activities of endothelial CFTR, relevant for vascular homeostasis and inflammation. We examined cells from human umbilical cords (HUVEC) and pulmonary artery isolated from non-cystic fibrosis (PAEC) and CF human lungs (CF-PAEC), under static conditions or physiological shear. CFTR activity, clearly detected in HUVEC and PAEC, was markedly reduced in CF-PAEC. CFTR blockade increased endothelial permeability to macromolecules and reduced trans‑endothelial electrical resistance (TEER). Consistent with this, CF-PAEC displayed lower TEER compared to PAEC. Under shear, CFTR blockade reduced VE-cadherin and p120 catenin membrane expression and triggered the formation of paxillin- and vinculin-enriched membrane blebs that evolved in shrinking of the cell body and disruption of cell-cell contacts. These changes were accompanied by enhanced release of microvesicles, which displayed reduced capability to stimulate proliferation in recipient EC. CFTR blockade also suppressed insulin-induced NO generation by EC, likely by inhibiting eNOS and AKT phosphorylation, whereas it enhanced IL-8 release. Remarkably, phosphodiesterase inhibitors in combination with a β2 adrenergic receptor agonist corrected functional and morphological changes triggered by CFTR dysfunction in EC. Our results uncover regulatory functions of CFTR in EC, suggesting a physiological role of CFTR in the maintenance EC homeostasis and its involvement in pathogenetic aspects of CF. Moreover, our findings open avenues for novel pharmacology to control endothelial dysfunction and its consequences in CF

De Novo Synthesis of Cyclooxygenase-1 Counteracts the Suppression of Platelet Thromboxane Biosynthesis by Aspirin

Aspirin affords cardioprotection through the acetylation of serine 529 in human cyclooxygenase-1 (COX-1) of anucleated platelets, inducing a permanent defect in thromboxane A 2 (TXA 2 )–dependent platelet function. However, heterogeneity of COX-1 suppression by aspirin has been detected in cardiovascular disease and may contribute to failure to prevent clinical events. The recent recognized capacity of platelets to make proteins de novo paves the way to identify new mechanisms involved in the variable response to aspirin. We found that in washed human platelets, the complete suppression of TXA 2 biosynthesis by aspirin, in vitro, recovered in response to thrombin and fibrinogen in a time-dependent fashion (at 0.5 and 24 hours, TXB 2 averaged 0.1±0.03 and 3±0.8 ng/mL; in the presence of arachidonic acid [10 μmol/L], it was 2±0.7 and 25±7 ng/mL, respectively), and it was blocked by translational inhibitors, by rapamycin, and by inhibitors of phosphatidylinositol 3-kinase. The results that COX-1 mRNA was readily detected in resting platelets and that [ 35 S]-methionine was incorporated into COX-1 protein after stimulation strongly support the occurrence of de novo COX-1 synthesis in platelets. This process may interfere with the complete and persistent suppression of TXA 2 biosynthesis by aspirin necessary for cardioprotection

Src-family kinases mediate an outside-in signal necessary for β2 integrins to achieve full activation and sustain firm adhesion of polymorphonuclear leucocytes tethered on E-selectin

In cell suspensions subjected to high-shear rotatory motion, human PMN (polymorphonuclear cells) adhered to E-selectin-expressing CHO (Chinese-hamster ovary) cells (CHO-E), and formed homotypic aggregates when challenged by E-selectin–IgG fusion protein, by a mechanism that involved β2 integrins. Both heterotypic and homotypic PMN adhesion was accompanied by tyrosine phosphorylation of a 110 kDa protein (P110). This event was prevented by blocking anti-(β2 integrin) antibodies and by inhibitors of Src-family kinases, suggesting that it was part of an ‘outside-in’ signalling that was initiated by integrin engagement. Interestingly, Src-family kinase inhibitors prevented β2-integrin-mediated (i) homotypic PMN adhesion triggered by E-selectin–IgG, (ii) heterotypic CHO-E/PMN adhesion in mixed-cell suspensions, and (iii) firm adhesion of PMN to CHO-E monolayers under physiological flow. Similarly to PMN treated with Src-family kinase inhibitors, PMN from hck−/−fgr−/− and hck−/−fgr−/−lyn−/− mice showed significant impairment of β2-integrin-mediated adhesion to CHO-E. Moreover, the expression of β2 integrin activation epitopes at the sites of cell–cell contact in CHO-E/PMN conjugates was abolished by Src-family kinase inhibitors. One component of P110 was identified as the FAK (focal adhesion kinase) Pyk2 (proline-rich tyrosine kinase 2), which was phosphorylated in a β2 integrin- and Src-family-kinase-dependent manner. Thus, Src-family kinases, and perhaps Pyk2, mediate a signal necessary for β2 integrin function in PMN tethered by E-selectin

Comportamento ingestivo de equinos em pastagens com Panicum maximum Jacq. na região do semiárido de Minas Gerais

Foi conduzido um experimento objetivando-se avaliar o comportamento ingestivo de equinos sob pastejo em pastagens estabelecidas com dois cultivares de Panicum maximum Jacq., cv. BRS Zuri e cv. Mombaça, em condições do semiárido mineiro. O delineamento utilizado foi o inteiramente casualizado com dois pastos representando os tratamentos, cada um com quatro repetições. O período experimental teve duração de 45 dias, sendo 17 dias de adaptação e quatro dias para avaliações do comportamento em pastejo de 10 éguas solteiras, realizadas durante 24 horas a cada 10 minutos, com intervalos de sete dias entre elas. Foram aferidos além dos tempos em pastejo diurno, noturno e diário, tempos total em ócio diurno, noturno e diário, a taxa e número de bocados diários, a estrutura morfológica e a composição químico-bromatológica dos pastos. No cv. BRS Zuri constatou-se maiores proteína bruta (11,76%), densidade volumétrica de folhas (208,91 kg/ha.cm MS) e taxa de bocado diário (35,10 bocado/minuto), enquanto que no cv. Mombaça observou-se maiores teores de matéria seca (39,16%), FDN (71,85%) e altura do pasto (61,75 cm). Porém, isso não provocou diferença entre os tempos em pastejo e ócio diurno, noturno e diário, das éguas. Éguas solteiras dispendem o mesmo tempo em pastejo sob temperaturas do ar elevadas independente dos cultivares de Panicum maximum Jacq. embora estas apresentem estruturas morfológicas diferentes

Role of the Yeast Gin4p Protein Kinase in Septin Assembly and the Relationship between Septin Assembly and Septin Function

To identify septin-interacting proteins in Saccharomyces cerevisiae, we screened for mutations that are synthetically lethal with a cdc12 septin mutation. One of the genes identified was GIN4, which encodes a protein kinase related to Hsl1p/Nik1p and Ycl024Wp in S. cerevisiae and to Nim1p/Cdr1p and Cdr2p in Schizosaccharomyces pombe. The Gin4p kinase domain displayed a two-hybrid interaction with the COOH-terminal portion of the Cdc3p septin, and Gin4p colocalized with the septins at the mother–bud neck. This localization depended on the septins and on the COOH-terminal (nonkinase) region of Gin4p, and overproduction of this COOH-terminal region led to a loss of septin organization and associated morphogenetic defects. We detected no effect of deleting YCL024W, either alone or in combination with deletion of GIN4. Deletion of GIN4 was not lethal but led to a striking reorganization of the septins accompanied by morphogenetic abnormalities and a defect in cell separation; however, remarkably, cytokinesis appeared to occur efficiently. Two other proteins that localize to the neck in a septin-dependent manner showed similar reorganizations and also appeared to remain largely functional. The septin organization observed in gin4Δ vegetative cells resembles that seen normally in cells responding to mating pheromone, and no Gin4p was detected in association with the septins in such cells. The organization of the septins observed in gin4Δ cells and in cells responding to pheromone appears to support some aspects of the model for septin organization suggested previously by Field et al. (Field, C.M., O. Al-Awar, J. Rosenblatt, M.L. Wong, B. Alberts, and T.J. Mitchison. 1996. J. Cell Biol. 133:605–616)

Aspirin and Simvastatin Combination for Cardiovascular Events Prevention Trial in Diabetes (ACCEPT-D): design of a randomized study of the efficacy of low-dose aspirin in the prevention of cardiovascular events in subjects with diabetes mellitus treated with statins

<p>Abstract</p> <p>Background</p> <p>Despite the high cardiovascular risk, evidence of efficacy of preventive strategies in individuals with diabetes is scant. In particular, recommendations on the use of aspirin in patients with diabetes mostly reflect an extrapolation from data deriving from other high risk populations. Furthermore, the putative additive effects of aspirin and statins in diabetes remain to be investigated. This aspect is of particular interest in the light of the existing debate regarding the need of multiple interventions to reduce total cardiovascular risk, which has also led to the proposal of a polypill. Aim of the study is to evaluate the efficacy of aspirin in the primary prevention of major cardiovascular events in diabetic patients candidate for treatment with statins. These preventive strategies will be evaluated on the top of the other strategies aimed at optimizing the care of diabetic patients in terms of metabolic control and control of the other cardiovascular risk factors.</p> <p>Methods/Design</p> <p>The ACCEPT-D is an open-label trial assessing whether 100 mg/daily of aspirin prevent cardiovascular events in patients without clinically manifest vascular disease and treated with simvastatin (starting dose 20 mg/die). Eligible patients will be randomly assigned to receive aspirin + simvastatin or simvastatin alone. Eligibility criteria: male and female individuals aged >=50 years with diagnosis of type 1 or type 2 diabetes, already on treatment with statins or candidate to start the treatment (LDL-cholesterol >=100 mg/dL persisting after 3 months of dietary advise). The primary combined end-point will include cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and hospital admission for cardiovascular causes (acute coronary syndrome, transient ischemic attack, not planned revascularization procedures, peripheral vascular disease). A total of 515 first events are needed to detect a reduction in the risk of major cardiovascular events of 25% (alpha = 0.05; 1-beta = 0.90). Overall, 5170 patients will be enrolled. The study will be conducted by diabetes specialists and general practitioners.</p> <p>Discussion</p> <p>The study will provide important information regarding the preventive role of aspirin in diabetes when used on the top of the other strategies aimed to control cardiovascular risk factors.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN48110081.</p

An Intense and Short-Lasting Burst of Neutrophil Activation Differentiates Early Acute Myocardial Infarction from Systemic Inflammatory Syndromes

BACKGROUND: Neutrophils are involved in thrombus formation. We investigated whether specific features of neutrophil activation characterize patients with acute coronary syndromes (ACS) compared to stable angina and to systemic inflammatory diseases. METHODS AND FINDINGS: The myeloperoxidase (MPO) content of circulating neutrophils was determined by flow cytometry in 330 subjects: 69 consecutive patients with acute coronary syndromes (ACS), 69 with chronic stable angina (CSA), 50 with inflammation due to either non-infectious (acute bone fracture), infectious (sepsis) or autoimmune diseases (small and large vessel systemic vasculitis, rheumatoid arthritis). Four patients have also been studied before and after sterile acute injury of the myocardium (septal alcoholization). One hundred thirty-eight healthy donors were studied in parallel. Neutrophils with normal MPO content were 96% in controls, >92% in patients undergoing septal alcoholization, 91% in CSA patients, but only 35 and 30% in unstable angina and AMI (STEMI and NSTEMI) patients, compared to 80%, 75% and 2% of patients with giant cell arteritis, acute bone fracture and severe sepsis. In addition, in 32/33 STEMI and 9/21 NSTEMI patients respectively, 20% and 12% of neutrophils had complete MPO depletion during the first 4 hours after the onset of symptoms, a feature not observed in any other group of patients. MPO depletion was associated with platelet activation, indicated by P-selectin expression, activation and transactivation of leukocyte β2-integrins and formation of platelet neutrophil and -monocyte aggregates. The injection of activated platelets in mice produced transient, P-selectin dependent, complete MPO depletion in about 50% of neutrophils. CONCLUSIONS: ACS are characterized by intense neutrophil activation, like other systemic inflammatory syndromes. In the very early phase of acute myocardial infarction only a subpopulation of neutrophils is massively activated, possibly via platelet-P selectin interactions. This paroxysmal activation could contribute to occlusive thrombosis

The Virgo data acquisition system

International audienc