We studied the effect of endogenous and exogenous prostaglandin E(2) (PGE(2)), a metabolite of arachidonic acid through the cyclooxygenase (COX) pathway, on interleukin (IL)-1 beta-induced COX-2 expression, using primary cultures of human bronchial smooth-muscle cells (HBSMC). Treatment with exogenous PGE(2) resulted in enhanced expression of IL-1 beta-induced COX-2 protein and messenger RNA (mRNA) as compared with the effect of the cytokine per se. Inhibition of PGE(2) production with a nonselective COX inhibitor (flurbiprofen, 10 microM) resulted in a significant reduction in IL-1 beta- induced COX-2 expression, supporting a role of endogenous COX metabolites in the modulation of COX-2 expression.
View Article and Find Full Text PDFWe investigated the expression of purinoceptors in human dendritic cells, providing functional, pharmacological, and biochemical evidence that immature and mature cells express P2Y and P2X subtypes, coupled to increase in the intracellular Ca(2+), membrane depolarization, and secretion of inflammatory cytokines. The ATP-activated Ca(2+) change was biphasic, with a fast release from intracellular stores and a delayed influx across the plasma membrane. A prolonged exposure to ATP was toxic to dendritic cells that swelled, lost typical dendrites, became phase lucent, detached from the substrate, and eventually died.
View Article and Find Full Text PDFBiochem Biophys Res Commun
November 2000
This study was undertaken to evaluate, in humans, the antioxidant activity of olive oil phenolics, namely hydroxytyrosol and oleuropein aglycone that share an orthodiphenolic (catecholic) structure. Human volunteers were administered olive oil samples containing increasing amounts of an olive oil phenolic extract that was characterized by gas-chromatography/mass spectrometry. The administration of phenol-rich oils was dose-dependently associated with a decreased urinary excretion of 8-iso-PGF(2alpha), a biomarker of oxidative stress.
View Article and Find Full Text PDFBackground: Oxidative stress is involved in the onset of several degenerative disorders, and epidemiological studies indicate that a high intake of dietary antioxidants, as in the case of the Mediterranean basin, is protective. Olive mill waste waters (OMWWs) are a byproduct of olive oil production rich in phenolic antioxidants, such as hydroxytyrosol. We tested the effects of a low dose of an OMWW extract in a model of sidestream smoke-induced oxidative stress in rats by evaluating the urinary excretion of 8-iso-prostaglandin (PG) F(2alpha) (iPF(2alpha)-III).
View Article and Find Full Text PDFJ Heart Valve Dis
September 2000
We report a case of edge-to-edge (Alfieri's technique) repair of congenital familiar tricuspid regurgitation in a 49-year-old woman, who had severe tricuspid regurgitation, atrial septal defect with left-to-right shunt, and two stenoses in peripheral branches of the left pulmonary artery, of no clinical relevance. The repair was performed through a longitudinal inferior partial sternotomy. The atrial septal defect was closed by direct suture; the anterior and posterior leaflets of the tricuspid valve were sutured together.
View Article and Find Full Text PDFAm J Physiol Cell Physiol
October 2000
We evaluated the levels of 15(S)-hydroxyeicosatetraenoic acid [15(S)-HETE] and the expression of 15-lipoxygenase (15-LO) mRNA in induced sputum obtained from 10 control and 15 chronic bronchitis subjects. 15(S)-HETE was evaluated by reverse phase high-performance liquid chromatography separation followed by specific RIA. 15-LO mRNA expression was determined by primed in situ labeling.
View Article and Find Full Text PDFBackground: Excessive bleeding may complicate congenital cardiac defects. To explain the pathogenesis of this abnormality, we evaluated selected parameters of primary hemostasis in patients with aortic valve stenosis before and after corrective surgery.
Methods And Results: We examined shear-induced platelet aggregation with the filter aggregometer test and von Willebrand factor (vWF) structure by evaluating the multimeric distribution and extent of subunit proteolysis.
Nerve growth factor (NGF) receptors are expressed in different cell types outside the nervous system, and increasing evidence indicates that NGF can act as a regulatory molecule during inflammatory and immune responses. In this study, we show that triggering of the high-affinity NGF receptor TrkA with agonists protects monocytes from apoptosis induced by gliotoxin or UVB radiation. TrkA stimulation up-regulates the expression of the anti-apoptotic Bcl-2 family members, Bcl-2, Bcl-XL, and Bfl-1.
View Article and Find Full Text PDFB-MYB is a ubiquitously expressed transcription factor involved in the regulation of cell survival, proliferation, and differentiation. In an attempt to isolate B-MYB-regulated genes that may explain the role of B-MYB in cellular processes, representational difference analysis was performed in neuroblastoma cell lines with different levels of B-MYB expression. One of the genes, the mRNA levels of which were enhanced in B-MYB expressing cells, was ApoJ/Clusterin(SGP-2/TRMP-2) (ApoJ/Clusterin), previously implicated in regulation of apoptosis and tumor progression.
View Article and Find Full Text PDFNew photoaffinity probes based on C-19 position of leukotriene A4 has been synthesized from 19-hydroxy-LTA4 methyl ester. Enzymatic conversion into the LTC4 analogue yielded a potential tool for the study of cys-LT2 receptors.
View Article and Find Full Text PDFBackground: Recent evidence shows that 15(S)-hydroxy-eicoisatetraenoic acid (15[S]-HETE) can be released and rapidly reincorporated into cellular lipids. These mechanisms exert several immunoregulatory functions that may be relevant in airway inflammation.
Objective: Our purpose was to evaluate the levels of both soluble and cell-associated 15(S)-HETE and to examine 15-lipoxygenase (15-LO) messenger RNA (mRNA) expression in sputum samples obtained from 10 control and 18 asthmatic subjects.
B-MYB is implicated in cell growth control, differentiation, and cancer and belongs to the MYB family of nuclear transcription factors. Evidence exists that cellular proteins bind directly to B-MYB, and it has been hypothesized that B-MYB transcriptional activity may be modulated by specific cofactors. In an attempt to isolate proteins that interact with the B-MYB DNA-binding domain, a modular domain that has the potential to mediate protein-protein interaction, we performed pull-down experiments with a glutathione S-transferase-B-MYB protein and mammalian protein extracts.
View Article and Find Full Text PDFBackground: Cysteinyl leukotrienes (cys-LT) can constrict small and large vessels and increase vascular permeability. Formation of cys-LT arising from polymorphonuclear leukocytes (PMNL) and endothelial cell cooperation (transcellular synthesis) led to the hypothesis that PMNL-endothelial cell adhesion may represent a key step toward the formation of vasoactive cys-LT.
Methods And Results: We studied the effect of pretreatment with a monoclonal antibody directed against the CD18 subunit of PMNL beta(2)-integrin on the synthesis of cys-LT in a PMNL-perfused isolated rabbit heart in vitro and in a model of permanent ligature of the left descending coronary artery in the rabbit in vivo.
The activity of the Santolina chamaecyparissus methanol extract was tested against the phospholipase A2 (PLA2)-induced mouse paw edema and in vitro inhibition of PLA2 activity. After fractionation, only the dichloromethane extract was active against the PLA2 in vitro test. In addition, it reduced the edema induced by arachidonic acid, and by 12-O-tetradecanoylphorbol-13-acetate in a multidose test.
View Article and Find Full Text PDFB-Myb is a transcription factor belonging to the myb family, whose activity has been associated with augmented DNA synthesis and cell cycle progression. We showed recently that B-Myb autoregulates its own expression through promoter transactivation. We report in this study that CDK9, the cyclin T associated kinase, which phosphorylates and activates RNA-Polymerase II, suppresses B-Myb autoregulation through direct interaction with the carboxyl-terminus of the B-Myb protein.
View Article and Find Full Text PDFAggregates of beta-amyloid peptide (betaAP), the main constituent of amyloid plaques in Alzheimer's brain, kill neurons by a not yet defined mechanism, leading to apoptotic death. Here, we report that both full-length betaAP((1-40)) or ((1-42)) and its active fragment betaAP((25-35)) act as proliferative signals for differentiated cortical neurons, driving them into the cell cycle. The cycle followed some of the steps observed in proliferating cells, including induction of cyclin D1, phosphorylation of retinoblastoma, and induction of cyclin E and A, but did not progress beyond S phase.
View Article and Find Full Text PDFObjective: The generation of 8-epiprostaglandin F2alpha (8-epi-PGF2alpha) by arachidonic acid (AA)- and lipopolysaccharide (LPS)- stimulated J774 macrophages has been investigated.
Material: Murine monocyte/macrophage J774 cell line.
Methods: Cells were incubated with AA or LPS and the amount of 8-epi-PGF2alpha, 6-ketoprostaglandin F1alpha (6-keto-PGF1alpha) and prostaglandin E2 (PGE2) released in the incubation media measured by radioimmunoassay (RIA) or, in some experiments, by enzyme immunoassay (EIA).
Leukotrienes can be produced by cooperative interactions between cells in which, for example, arachidonate derived from one cell is oxidized to leukotriene A(4) (LTA(4)) by another and this can then be exported for conversion to LTB(4) or cysteinyl leukotrienes (cys-LTs) by yet another. Neutrophils do not contain LTC(4) synthase but are known to cooperate with endothelial cells or platelets (which do have this enzyme) to generate cys-LTs. Stimulation of human neutrophils perfusing isolated rabbit hearts resulted in production of cys-LTs, whereas these were not seen with perfused hearts alone or isolated neutrophils.
View Article and Find Full Text PDFA 7-y-old boy with acute lymphoblastic leukaemia (ALL) received 600 mg of i.v. methotrexate (MTX) over 2 h, followed by triple intrathecal therapy (TIT) with cytosine arabinoside 30 mg, methylprednisolone 10 mg and MTX 300 mg (instead of the prescribed 12 mg).
View Article and Find Full Text PDFThe population of Argentina is mostly composed of people of European ancestry. Aboriginal communities are at present very reduced in number and restricted to small geographically isolated patches. Three aboriginal communities, the Mapuche, Tehuelche and Wichi, were selected for short tandem repeat (STR) investigation.
View Article and Find Full Text PDFCell-mediated immune (CMI) responses to Bordetella pertussis antigens (pertussis toxin [PT], pertactin [PRN], and filamentous hemagglutinin [FHA]) were assessed in 48-month-old recipients of acellular pertussis [aP] vaccines (either from Chiron-Biocine [aP-CB] or from SmithKline Beecham [aP-SB]) and compared to CMI responses to the same antigens at 7 months of age, i.e., 1 month after completion of the primary immunization cycle.
View Article and Find Full Text PDFHigh-dose chemotherapy with autologous stem cell transplantation is an increasingly used procedure in oncohematologic diseases and represents a promising strategy in selected patients with solid tumors. In autologous stem cell transplantation, the risk of reinfusion of clonogenic tumor cells is a remarkable biologic obstacle that can be at least partly overcome by ex vivo graft purging to reduce residual tumor. Mafosfamide and 4-hydroxyperoxycyclophosphamide, active metabolites of cyclophosphamide, are the most widely used pharmacologic agents for ex vivo bone marrow purging.
View Article and Find Full Text PDFSince its isolation exactly a decade ago, B-Myb has intrigued a growing number of scientists interested in understanding the mechanisms of cell proliferation. In many aspects the B-Myb story resembles that of a fashionable transcription factor involved in cell cycle control: E2F-1. Similar to E2F-1, B-Myb is a transcription factor whose expression is regulated at the G1/S border of the cell cycle.
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