39 research outputs found
Understanding Households – a few thoughts
Buccellati, F. 2014. “Understanding Households – a Few Thoughts.” In House and Household Economies in 3rd Millennium B.C.E. Syro-Mesopotamia, edited by F. Buccellati, T. Helms, and A. Tamm, 35–42. BAR International 2682. Oxford: Archaeopress
Size Matters – Understanding Monumentality Across Ancient Civilizations
Buccellati, F., S. Hageneuer, S. van der Heyden, and F. Levenson, eds. 2019. Size Matters – Understanding Monumentality Across Ancient Civilizations. Bielefeld: transcript. https://doi.org/10.14361/9783839445389
CHF6001 Inhibits NF-κB activation and neutrophilic recruitment in LPS-induced lung inflammation in mice
Inhibitors of phosphodiesterase 4 (PDE4) are potent anti-inflammatory agents, inhibiting the production of inflammatory mediators through the elevation of intracellular cAMP concentrations. We studied the activity of a novel PDE4 inhibitor, CHF6001, both in vitro in human cells and in vivo, using bioluminescence imaging (BLI) in mice lung inflammation. Mice transiently transfected with the luciferase gene under the control of an NF-\u3baB responsive element (NF-\u3baB-luc) have been used to assess the in vivo anti-inflammatory activity of CHF6001 in lipopolysaccharide (LPS)-induced lung inflammation. BLI as well as inflammatory cells and the concentrations of pro-inflammatory cytokines were monitored in bronchoalveolar lavage fluids (BALF) while testing in vitro its ability to affect the production of leukotriene B4 (LTB4), measured by LC/MS/MS, by LPS/LPS/N-formyl-methionyl-leucyl-phenylalanine (fMLP)-activated human blood. CHF6001 inhibited the production of LTB4 in LPS/fMLP-activated human blood at sub-nanomolar concentrations. LPS-induced an increase of BLI signal in NF-\u3baB-luc mice, and CHF6001 administered by dry powder inhalation decreased in parallel luciferase signal, cell airway infiltration, and pro-inflammatory cytokine concentrations in BALF. The results obtained provide in vitro and in vivo evidence of the anti-inflammatory activity of the potent PDE4 inhibitor CHF6001, showing that with a topical administration that closely mimics inhalation in humans, it efficiently disrupts the NF-\u3baB activation associated with LPS challenge, an effect that may be relevant for the prevention of exacerbation episodes in chronic obstructive pulmonary disease subjects
Monoclonal anti-CD18 antibody prevents transcellular biosynthesis of cysteinyl leukotrienes in vitro and in vivo and protects against leukotriene-dependent increase in coronary vascular resistance and myocardial stiffness
Background - 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 \u3b22-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. Challenge of PMNL-perfused rabbit hearts with formyl-met-leu- phe (0.3 \u3bcmol/L) caused synthesis of cys-LT and increase in coronary perfusion pressure that were prevented by the anti-CD18 antibody. Similar results were obtained with the use of A-23187 (0.5 \u3bcmol/L) as a challenge. Persistence of PMNL-associated myeloperoxidase activity in the perfusion buffer was observed in the presence of the anti-CD18 antibody, indicating decreased PMNL infiltration. Coronary artery ligature in vivo increased urinary excretion of leukotriene E4, supporting the activation of the 5- lipoxygenase pathway during experimental acute myocardial infarction. Pretreatment with the anti-CD18 antibody (1 mg/kg) prevented the increase in leukotriene E4 excretion. Conclusions - These data support the importance of adhesion in promoting cys-LT formation, originating from PMNL-endothelial cell cooperation, and contributing to myocardial stiffness and increased coronary resistance
Leukotriene modifiers: novel therapeutic opportunities in asthma
Cysteinyl leukotrienes (Cys-LT) are powerful proinflammatory autacoids that cause long-lasting bronchoconstriction, plasma leakage, increased mucus production; their biological activity suggests a prominent role in the etiopathology of asthma and several Cys-LT receptor antagonists and synthetase inhibitors have been developed as new antiasthmatic drugs. Zafirlukast was discovered by a mechanism-based approach to drug discovery; early structure-activity relationship analyses of the prototype SRS-A antagonist FPL-55712, lead to the identification of an indole-containing lead compound that was more specific than FPL-55712. Modifications were made on the lipid-like tail, indole backbone and acidic head region of this lead compound, resulting in potent and selective leukotriene receptor antagonists such as ICI-198615 and 204219 (zafirlukast). On the basis of successful results in preclinical asthma models, zafirlukast was recommended for clinical development and became the first leukotriene-modifier to be approved for the treatment of asthma. Leukotriene biosynthesis inhibitors (LSI) also represent a promising approach to the treatment of asthma and may theoretically provide a broader protection than Cys-LT receptor antagonists by inhibition of the synthesis of the two major leukotrienes, the Cys-LT and the chemotactic LTB4. The LSI BAY X-1005 is the result of a broad chemistry program that identified 15-HETE as an endogenous inhibitor of leukotriene synthesis and REV 5901 as a lead prototypic quinoline-based 5-lipoxygenase (5-LO) inhibitor. Clinical studies demonstrated the effectiveness of BAY X-1005 in experimental conditions such as allergen provocation and cold-air induced asthma. However, no consistent treatment effect in the overall asthma population (mild to moderately severe asthmatics) lead to discontinuation of its development
Modulation of leukocyte-endothelial cell interaction and leukotriene dependent vasoconstriction by prostacyclin mimetics in the isolated rabbit heart
Bronchodilators Modulate Inflammation In Chronic Obstructive Pulmonary Disease Subjects
Chronic obstructive pulmonary disease (COPD) is characterized by neutrophilic airway inflammation and oxidative stress. Leukotriene B4 (LTB4), a potent proinflammatory mediator, is synthesized by 5-lipoxygenase (5-LO), which is activated by the presence of lipid hydroperoxides resulting from oxidative stress on biological membranes. We proposed to evaluate the effect of a four week treatment with two different bronchodilators of common practice in COPD treatment, on the production of reactive oxygen species (ROS), in particular superoxide anions, and of LTB 4 by peripheral blood neutrophils obtained from COPD subjects. 24 subjects among the COPD outpatients were enrolled, and randomized to receive either formoterol (12 \u3bcg bid) or tiotropium (18 \u3bcg od). Peripheral blood neutrophils were obtained at the start and at the end of the treatment, and production of superoxide anions and of LTB4 were evaluated as previously published. The results obtained showed a decrease in the unstimulated production of superoxide by isolated neutrophils in both groups, but tiotropium only was effective in modulating the production of LTB4, while formoterol caused an increased production of superoxide in response to fMLP, when compared to values obtained before treatment. In conclusion, tiotropium showed a better antiinflammatory activity profile when compared to formoterol in a clinical setting, reducing superoxide and LTB4 production by peripheral neutrophils obtained from COPD subjects
Vasoconstriction to polymorphonuclear leukocytes in the isolated, perfused rabbit heart: inhibition by prostacyclin mimetics
Perfusion of the isolated rabbit heart with 5 x 10 6 human polymorphonuclear leukocytes (PMNL), under recirculating conditions (50 ml) and challenge with A-23187 (0.5 \u3bcM) increased coronary perfusion pressure (CPP) sixfold, accompanied by increased levels of sulfidopeptide leukotrienes (CYS-LT), which had previously shown to correlate linearly with the increase in CPP. Pretreatment (20 min) of isolated rabbit hearts with the prostacyclin (PGI 2) analogue iloprost (3 nM) resulted in significant protection against the increase in CPP and in almost complete inhibition of 5-lipoxygenase (5- LO) product synthesis. Similarly, pretreatment of isolated rabbit heart with defibrotide (200 \u3bcg/ml), a polydeoxyribonucleotide derivative known to inhibit PMNL activation and enhance PGI 2 production by heart endothelial cells, produced significant protection against the increase in CPP and almost complete inhibition of 5-LO product synthesis. Neither iloprost nor defibrotide affected the A-23187-induced arachidonic acid (AA) metabolism in isolated PMNL alone. Inhibition of rabbit cyclooxygenase by intravenous (i.v.) administration of lysine-acetylsalicylate (60 mg/kg) 2 h before the animals were killed significantly reduced the protection provided by defibrotide, with a parallel fivefold increase in sulfidopeptide LT levels, returning to values in the range observed in control hearts. Control of endogenous modulators of leukocyte-vascular wall interactions such as PGI 2 results in significant changes in sulfidopeptide LT production in an organ model of transcellular metabolism of LT A 4, suggesting a novel mechanism of action for cardioprotective drugs in myocardial ischemia
Formation of sulphidopeptide-leukotrienes by cell-cell interaction causes coronary vasoconstriction in isolated, cell-perfused heart of rabbit.
1. We have studied the transcellular biosynthesis of bioactive leukotrienes (LTs), generated upon blood cell-vascular wall interactions and their functional consequences, in the spontaneously beating, cell-perfused, heart of the rabbit. Rabbit isolated hearts were perfused under recirculating conditions (50 ml) with 5 x 10(6) cells of unpurified (buffy coat) or purified human neutrophils (PMNL), and challenged with 0.5 microM A23187 for 30 min. Coronary perfusion pressure (CPP), heart rate (HR), left ventricular end-diastolic pressure (LVEDP) and left ventricular pressure (LVP) were monitored continuously. Leukotriene formation was measured by specific enzyme-immunoassay and confirmed by reversed phase h.p.l.c. and u.v. spectral analysis. 2. Basal CPP values averaged 44 +/- 1.4 mmHg; A23187 triggered a marked increase in CPP both in the presence of buffy coat cells (+100% above basal) and PMNL (+270% above basal); the latter change in CPP was accompanied by a rise in LVEDP (+138% above basal). 3. The increase in CPP was preceded by a statistically significant rise in iLTC4-D4 concentration in the circulating buffer. Pretreatment with two structurally unrelated LTD4 receptor antagonists, LY171883 and SKF104353 (10 microM), fully prevented the increase in CPP and LVEDP. A similar protection was also observed when the rabbit heart was perfused with PMNL that had been pretreated with MK886 (1 microM), a potent inhibitor of leukotriene biosynthesis. 4. The increased coronary tone was accompanied by a marked release of lactate dehydrogenase (LDH), a marker of ischaemic damage; pretreatment of the heart with the LTD4 receptor antagonists as well as of the PMNL with MK886 resulted in a complete suppression of LDH activity release.(ABSTRACT TRUNCATED AT 250 WORDS