Inhibition of platelet-activating factor- and zymosan-activated serum-induced chemotaxis of human neutrophils by nedocromil sodium, BN 52021 and sodium cromoglycate.

1. Inflammatory cells such as eosinophils and neutrophils are thought to contribute actively to the pathogenesis of asthma since they infiltrate into the lung tissue. These cells are mobilized by lipid-like and protein-like chemotactic factors.

Nedocromil sodium inhibits the A23187- and opsonized zymosan-induced leukotriene formation by human eosinophils but not by human neutrophils.

1. Inflammatory cells such as eosinophils and neutrophils are thought to contribute actively to the pathogenesis of asthma by the release of bronchoconstrictor mediators including leukotrienes. Previous studies have revealed the almost exclusive synthesis of leukotriene C4 (LTC4) by human eosinophils and of leukotriene B4 (LTB4), 20-OH-LTB4 and the non-enzymatically formed LTB4-isomers by neutrophils when stimulated in vitro with the calcium ionophore A23187 or opsonized zymosan (OZ).

Inhibitory effects of nedocromil sodium on the in vitro induced migration and leukotriene formation of human granulocytes.

Inflammatory cells, such as neutrophils and eosinophils, are thought to actively contribute to the pathogenesis of asthma since they infiltrate into the lung tissue and may be activated locally to release bronchoconstrictor mediators. In this study we provide evidence that nedocromil sodium is capable of effectively inhibiting the platelet-activating factor (PAF) and zymosan-activated serum (ZAS)-induced chemotaxis of polymorphonuclear granulocytes (PMN) [IC50 approximately 1 nmol/L and 0.1 mumol/L respectively].

Leukotriene C4 formation by purified human eosinophils can be induced by arachidonic acid in the absence of calcium-ionophore A23187.

Addition of arachidonic acid (50 microM) to purified human eosinophils leads to the formation of considerable amounts of LTC4 [11.3 +/- 1.3) x 10(6) molecules/cell, mean +/- SEM, n = 10), 15-HETE [412 +/- 142) x 10(6) molecules/cell, mean +/- SEM, n = 3) and 15-series leukotrienes [35 +/- 15) x 10(6) molecules/cell, mean +/- SEM, n = 3).

Molecular mechanics calculation of geometries of NAD+ derivatives, modified in the nicotinamide group, in a ternary complex with horse liver alcohol dehydrogenase.

The geometry of seven NAD+ analogues bound to horse liver alcohol dehydrogenase (LADH) modified only in their nicotinamide group, have been studied using AMBER molecular mechanics energy-minimization procedures. Starting geometries were taken from X-ray crystallographic data for NAD+/Me2SO/LADH reported by Eklund and co-workers. In this study the NAD+ analogues were encaged by the constituent amino acids of the enzyme within a range of 0.

An improved method for the isolation of eosinophilic granulocytes from peripheral blood of normal individuals.

A simple and improved procedure is described for the isolation of human eosinophils from normal individuals with about 2% eosinophils in their peripheral blood. This method comprises a preincubation of a mixed granulocyte preparation with 10 nM fMLP for 10 min at 37 degrees C followed by a one-step density centrifugation on isotonic Percoll. The recovery of eosinophils is 49 +/- 4% at 89 +/- 4% purity.

Arachidonic acid can induce leukotriene C4 formation by purified human eosinophils in the absence of other stimuli.

Stimulation of purified human eosinophils with 50 microM arachidonic acid leads to the production of leukotriene C4, 15-hydroxy-eicosatetraenoic acid and 15-series leukotrienes. The ratio of the amounts of leukotriene C4 and 15-lipoxygenase products was found to be strongly dependent on the arachidonic acid concentration, being relatively large at low arachidonic acid concentrations and very small at high arachidonic acid concentrations. In the presence of 1 microM platelet-activating factor a significant elevation of leukotriene C4 formation is observed, whereas the formation of 15-lipoxygenase products remains unaltered.

Platelet-activating factor induces leukotriene C4 synthesis by purified human eosinophils.

Platelet-activating factor, at a concentration of 10 microM, was capable of inducing leukotriene C4 synthesis by eosinophils of healthy donors, i.e. (3.

Porcine tissue plasminogen activator. Immunoaffinity purification, structural properties and glycosylation pattern.

Tissue plasminogen activator was purified in high yield from pig heart by immunoaffinity chromatography and characterized by analysis of the glycosylation pattern and the N-terminal amino acid sequence. Comparisons with the human enzyme reveals residue exchanges in the A-chain at positions 3 (porcine Arg/human Gln) and 5 (Thr/Ile), and in the B-chain at positions 6 (Tyr/Phe), 10 (Thr/Ala) and 20 (Val/Ala). The glycosylation pattern for the porcine activator was determined by endoglycosidase treatment followed by gel electrophoresis.

Platelet-activating factor (PAF-acether) induced leukotriene C4 formation and luminol dependent chemiluminescence by human eosinophils.

Human eosinophils are capable of synthesizing almost exclusively the strongly spasmogenic compound LTC4 when stimulated with either the calcium ionophore A 23187 or opsonized zymosan (OZ). Although PAF-acether in concentrations ranging from 10 nM to 1 microM is hardly capable of inducing significant LTC4 synthesis itself, it significantly enhances the OZ-induced LTC4 formation at a concentration of 1 microM. However, at a concentration of 10 microM, PAF-acether itself is capable of inducing LTC4 formation comparable with that induced by OZ.

Assay characteristics and fibrin affinity of plasminogen activators of the intrinsic fibrinolytic system.

Plasminogen activators (PA) in the euglobulin fraction of dextran sulfate activated plasma (DS-EF) were assayed on fibrin plates. Activity related to tissue plasminogen activator (t-PA) or urokinase (u-PA) was quantified by antiserum inhibition. The DS-EF contained 30% t-PA, 30% u-PA and 40-50% activity unrelated to t-PA or u-PA.

Cluster sampling for immunization coverage.

The WHO/EPI cluster sampling method for immunization coverage surveys is part of the course for management training in EPI programmes. The application of this method, based on a framework of villages, is impractical in dispersed populations common in many countries in Africa. To make the method work under those circumstances leads to unacceptable bias, which tends to overestimate the real coverage rate.

On the optimal conditions of LTC4 formation by human eosinophils in vitro.

The optimal conditions for the -in vitro- LTC4 formation by the human eosinophil, isolated from peripheral blood, have been investigated in detail. LTC4 formation was found strongly Ca2+ and ionophore dependent and was complete after 20 min. Maximal LTC4 production was observed in the presence of 2 mM Ca2+, 10 microM ionophore A23187 and 5 mM glutathione.

Exclusive leukotriene C4 synthesis by purified human eosinophils induced by opsonized zymosan.

Purified human eosinophils were challenged with N-formyl-methionyl-leucyl-phenylalanine, leukotriene B4, platelet-activating-factor, valyl-glycyl-seryl-glutamic acid, phorbol myristate acetate, zymosan, opsonized zymosan and the calcium ionophore A23187 to induce leukotriene synthesis. Reversed-phase high performance liquid chromatography analysis demonstrated the almost exclusive synthesis of leukotriene C4 by eosinophils of 11 healthy donors after challenge with opsonized zymosan [(22 +/- 4) X 10(6) molecules LTC4/cell, mean +/- SE] or the calcium ionophore A23187 [(54 +/- 7) X 10(6) molecules LTC4/cell, mean +/- SE]. The other agents were not capable of inducing leukotriene formation.

Simplification of a commercially available serum angiotensin-converting enzyme determination.

The spectrophotometric method for the determination of angiotensin-converting enzyme in serum using p-hydroxyhippuryl-L-histidyl-L-leucine as substrate is commercially available as a test kit. It shows excellent linearity over the whole range of catalytic concentration found in serum. We describe several modifications of this method to simplify and economize the procedure.

Measurement of total IgE antibody levels in lacrimal fluid of patients suffering from atopic and non-atopic eye disorders. Evidence for local IgE production in atopic eye disorders?

Total IgE levels in lacrimal fluid of patients suffering from different eye disorders were quantitatively measured by a modification of the paper radio immuno sorbent test (PRIST). The geometric mean values for patients with atopic conjunctivitis, patients with keratoconjunctivitis vernalis, and patients with asthma without conjunctivitis differed significantly from those for control persons and those for patients without atopic conjunctivitis. Besides lacrimal fluid IgE levels, serum IgE levels as well as lacrimal fluid and serum albumin levels were measured.

Sequence of formation of molecular forms of plasminogen and plasmin-inhibitor complexes in plasma activated by urokinase or tissue-type plasminogen activator.

The pathway of plasminogen transformation was studied in plasma, particularly in relation to fibrin formation and the subsequent stimulation of plasminogen activation. Plasminogen was activated by urokinase (low fibrin-affinity) or tissue-type plasminogen activator (high fibrin-affinity). Formation of 125I-labelled free and inhibitor-bound plasminogen derivatives was quantified after their separation by acetic acid/urea/polyacrylamide-gel electrophoresis.

Measles immunization with further attenuated heat-stable measles vaccine using five different methods of administration.

Further attenuated heat-stable measles vaccine Attenuvax was administered randomly to 109 children using five different methods and a control group (24). Vaccine administration by syringe and needle (0.5 ml) and by jet-injector (0.

The epidemiology of trachoma blindness in southern Africa.

Twenty five years ago medical scientists working in Southern Africa clarified the natural history of trachoma and how it affected vision impairment and eventual blindness in rural communities. After this, doctors attempted to take appropriate actions against the disease. Initial surveys indicated a blindness prevalence rate of 760/100,000 among rural Africans compared to 100/100,000 among the white population.

Fibrinolytic activity of cerebral tissue after experimental subarachnoid haemorrhage: inhibitory effect of tranexamic acid (AMCA).

The influence of tranexamic acid (AMCA) on the fibrinolytic activity induced by plasminogen activators (PA) of the cerebral leptomeninges, arteries and choroid plexus after artificial subarachnoid haemorrhage (SAH) was studied in 90 rabbits. SAH was induced by injection of 1-2 ml autologous blood into the suboccipital cistern. Half of the rabbits were given AMCA, 200 mg per kg body weight, in daily single i.