Risk factors of postoperative vomiting in children receiving continuous intravenous morphine

BACKGROUND

Risk factors of postoperative vomiting (POV) have been less extensively explored in children compared to adults. We analyzed the risk factors of POV in children receiving continuous intravenous (i.v.) morphine in a standardized manner without POV prophylaxis after major surgery.

METHODS

This observational retrospective study included 235 children aged from 2 to 216 months (91 F:144 M, 11.5% <6 months, 31.5% 6-11 months). The primary end point was the occurrence of at least one episode of POV recorded on the nursing chart. The independent predictors of POV were determined by univariate analysis followed by a multivariate analysis by logistic regression. The data are presented as either medians (25th-75th percentile) or as values with a 95% confidence interval.

RESULTS

Continuous i.v. morphine was administered over 42 (22-60) h with an initial infusion rate of 20 µg x kg(-1) x h(-1) in 63% of cases, which was increased in 31.5% of cases and was accompanied by an additional bolus in 39.2% of children. At least one episode of POV occurred in 22.6% of children. The following three independent factors were associated with POV: female gender (OR 3.324 [1.695-6.519], P=0.0005), urological surgery (OR 5.605 [1.291-24.340], P=0.0214) and age (OR 1.012 [1.006-1.018], P<0.0001). The discriminating characteristics of the model were good with an ROC curve AUC of 0.778, sensitivity of 71.7% and specificity of 71.4% for a 0.22 cut-off value of POV incidence. The positive predictive value was 42.2%, and the negative predictive value was 89.6%.

CONCLUSION

Female gender, which is usually considered a risk factor after puberty, should be taken into account independent of age to guide the POV prophylaxis in children receiving a postoperative continuous i.v. morphine infusion.

Qualitative and quantitative differences in cuticular hydrocarbons between laboratory and field colonies of Pogonomyrmex barbatus

Ants held in the laboratory and field ants of the species Pogonomyrmex barbatus have quantitative differences in their cuticular hydrocarbons and a qualitative difference in their methyl-branched hydrocarbons. Laboratory-held workers showed twice the hydrocarbon content as field ants. This difference was mainly due to higher amounts of straight-chain alkanes and methyl-branched alkanes in laboratory ants, whereas the proportion of the alkenes remained the same for both groups. In addition to the absence of some hydrocarbons in the field colonies, one of the methyl-branched hydrocarbons differed in amount and branching pattern between the two groups of ants. Whereas, notable peaks of 2-methylalkanes were identified in ants kept in the laboratory, these compounds could not be identified in ants living in their natural habitat. However, a trace amount of 4-methyltriacontane was found in lieu of the 2-methyltriacontane counterpart in field ants. Possible explanations for both qualitative and quantitative differences are discussed.

Task-related environment alters the cuticular hydrocarbon composition of harvester ants

Within a colony of harvester ants (Pogonomyrmex barbatus), workers in different task groups differ in the hydrocarbon composition of the cuticle. Foragers and patrollers, which spend extended periods of time outside the nest, have a higher proportion of saturated, unbranched hydrocarbons (n-alkanes) on the cuticle than nest maintenance workers, which spend only short periods of time outside the nest. We tested whether these task-related differences in ant cuticular chemistry arise from exposure to conditions outside the nest. Nest maintenance workers experiencing daily, short-term outside exposure developed a higher proportion of n-alkanes on the cuticle than workers kept inside the lab. Independent manipulations of ultraviolet radiation, relative humidity, and temperature revealed that only the combination of high temperature (ca. 38 degrees C) and low relative humidity (ca. 8%) increased the proportion of cuticular n-alkanes. The results indicate that warm dry conditions, such as those encountered when an ant leaves the nest, trigger changes in cuticular chemistry.

Pharmacological Properties of Peptides Derived from Stromal Cell-Derived Factor 1: Study on Human Polymorphonuclear Cells

Small compounds capable of blocking the stromal cell-derived factor 1 (SDF-1) receptor CXCR4 may be potentially useful as anti-inflammatory, antiallergic, immunomodulatory, and anti-human immunodeficiency virus (HIV) agents. SDF-1-derived peptides have proven to target CXCR4 efficiently despite a 100-fold lower affinity (or more) than SDF-1. Here we studied the binding and antiviral properties of a series of substituted SDF-1-derived N-terminal peptides and tested their functional effects on human polymorphonuclear cells, because these cells are very reactive to chemokines and chemoattractants. All peptides bound to CXCR4 and inhibited HIV entry in a functional assay on CD4(+) HeLa cells. A 10-residue substituted dimer, derived from the 5-14 sequence of SDF-1, displayed the highest affinity for CXCR4 (K(i) value of 290 nM, a reduction of only 15-fold compared with SDF-1) and was also the best competitor for HIV entry (IC(50) value of 130 nM). Whereas most peptides displayed CXCR4-independent functional effects on human polymorphonuclear cells, including the modulation of calcium fluxes and the activation of superoxide anion production at high concentration (10 microM), the peptide dimer was devoid of these nonspecific effects at antiviral concentrations. Overall, this study shows that appropriate modifications of SDF-1-derived N-terminal peptides may ameliorate their binding and viral blocking properties without generating significant unspecific side effects.

Novel wax esters and hydrocarbons in the cuticular surface lipids of the red harvester ant, Pogonomyrmex barbatus

The cuticular surface lipids of the red harvester ant, Pogonomyrmex barbatus, were found to contain minor amounts of novel wax esters, in addition to the major components, hydrocarbons. The wax esters ranged in carbon number from C19 to C31 and consisted of esters of both odd- and even-numbered alcohols and acids. Each wax ester with a given carbon number eluted at several different retention times indicating possible methyl branching in either the fatty acid or alcohol moiety, or in both moieties. Each eluting peak of wax esters consisted of a mixture of wax esters of the same carbon number in which the fatty acid moiety ranged from C8 to C18, and the alcohol moiety ranged from C8 to C17. Some wax esters were largely found on the head indicating they may be of a glandular origin. The hydrocarbons consisted of: n-alkanes, C23 to C33; odd-numbered n-alkenes, C27 to C35; and the major components, methyl-branched alkanes, C26 to over C49. Notable components of the methyl-branched alkanes were 2-methyltriacontane, and the novel trimethylalkanes with a single methylene between the first and second branch points, 13,15,19-trimethylhentriacontane and 13,15,21-trimethyltritriacontane.

Metamorphosis in drosophila and other insects: the fate of neurons throughout the stages

The nervous system of insects is profoundly reorganised during metamorphosis, affecting the fate of different types of neuron in different ways. Almost all adult motor neurons derive from larval motor neurons that are respecified for adult functions. A subset of larval motor neurons, those which mediate larval- or ecdysis-specific behaviours, die before and immediately after eclosion, respectively. Many adult interneurons develop from larval interneurons, whereas those related to complex adult sense organs originate during larval life from persisting embryonic neuroblasts. Sensory neurons of larvae and adults derive from essentially two distinct sources. Larval sensory neurons are formed in the embryonic integument and - with few exceptions - die during metamorphosis. Their adult counterparts, on the other hand, arise from imaginal discs. Special emphasis is given in this review to the metamorphic remodelling of persisting neurons, both at the input and output levels, and to the associated behavioural changes. Other sections deal with the programmed death of motor neurons and its causes, as well as with the metamorphic interactions between motor neurons and their target muscles. Remodelling and apoptosis of these two elements appear to be under independent ecdysteroid control. This review focusses on the two most thoroughly studied holometabolous species, the fruitfly Drosophila melanogaster and the tobacco hornworm moth Manduca sexta. While Manduca has a long tradition in neurodevelopmental studies due to the identification of many of its neurons, Drosophila has been increasingly used to investigate neural reorganisation thanks to neurogenetic tools and molecular approaches. The wealth of information available emphasises the strength of the insect model system used in developmental studies, rendering it clearly the most important system for studies at the cellular level.

Dual signaling of human Mel1a melatonin receptors via G(i2), G(i3), and G(q/11) proteins

Mel 1a melatonin receptors belong to the super-family of guanine nucleotide-binding regulatory protein (G protein)-coupled receptors. So far, interest in Mel 1a receptor signaling has focused mainly on the modulation of the adenylyl cyclase pathway via pertussis toxin (PTX)-sensitive G proteins. To further investigate signaling of the human Mel 1a receptor, we have developed an antibody directed against the C terminus of this receptor. This antibody detected the Mel 1a receptor as a protein with an apparent molecular mass of approximately 60 kDa in immunoblots after separation by SDS-PAGE. It also specifically precipitated the 2-[125I]iodomelatonin (125I-Mel)-labeled receptor from Mel 1a-transfected HEK 293 cells. Coprecipitation experiments showed that G(i2), G(i3), and G(q/11) proteins couple to the Mel 1a receptor in an agonist-dependent and guanine nucleotide-sensitive manner. Coupling was selective since other G proteins present in HEK 293 cells, (G(i1), G(o), G(s), G(z), and G12) were not detected in receptor complexes. Coupling of the Mel 1a receptor to G(i) and G(q) was confirmed by inhibition of high-affinity 125I-Mel binding to receptors with subtype-selective G protein alpha-subunit antibodies. G(i2) and/or G(i3) mediated adenylyl cyclase inhibition while G(q/11) induced a transient elevation in cytosolic calcium concentrations in HEK 293 cells stably expressing Mel 1a receptors. Melatonin-induced cytosolic calcium mobilization via PTX-insensitive G proteins was confirmed in primary cultures of ovine pars tuberalis cells endogenously expressing Mel 1a receptors. In conclusion, we report the development of the first antibody recognizing the cloned human Mel 1a melatonin receptor protein. We show that Mel 1a receptors functionally couple to both PTX-sensitive and PTX-insensitive G proteins. The previously unknown signaling of Mel 1a receptors through G(q/11) widens the spectrum of potential targets for melatonin.

Dual signaling of human Mel1a melatonin receptors via G(i2), G(i3), and G(q/11) proteins

Mel 1a melatonin receptors belong to the super-family of guanine nucleotide-binding regulatory protein (G protein)-coupled receptors. So far, interest in Mel 1a receptor signaling has focused mainly on the modulation of the adenylyl cyclase pathway via pertussis toxin (PTX)-sensitive G proteins. To further investigate signaling of the human Mel 1a receptor, we have developed an antibody directed against the C terminus of this receptor. This antibody detected the Mel 1a receptor as a protein with an apparent molecular mass of approximately 60 kDa in immunoblots after separation by SDS-PAGE. It also specifically precipitated the 2-[125I]iodomelatonin (125I-Mel)-labeled receptor from Mel 1a-transfected HEK 293 cells. Coprecipitation experiments showed that G(i2), G(i3), and G(q/11) proteins couple to the Mel 1a receptor in an agonist-dependent and guanine nucleotide-sensitive manner. Coupling was selective since other G proteins present in HEK 293 cells, (G(i1), G(o), G(s), G(z), and G12) were not detected in receptor complexes. Coupling of the Mel 1a receptor to G(i) and G(q) was confirmed by inhibition of high-affinity 125I-Mel binding to receptors with subtype-selective G protein alpha-subunit antibodies. G(i2) and/or G(i3) mediated adenylyl cyclase inhibition while G(q/11) induced a transient elevation in cytosolic calcium concentrations in HEK 293 cells stably expressing Mel 1a receptors. Melatonin-induced cytosolic calcium mobilization via PTX-insensitive G proteins was confirmed in primary cultures of ovine pars tuberalis cells endogenously expressing Mel 1a receptors. In conclusion, we report the development of the first antibody recognizing the cloned human Mel 1a melatonin receptor protein. We show that Mel 1a receptors functionally couple to both PTX-sensitive and PTX-insensitive G proteins. The previously unknown signaling of Mel 1a receptors through G(q/11) widens the spectrum of potential targets for melatonin.

Effect of piracetam on polyphosphoinositide metabolism, cytosolic calcium release, and oxidative burst in human polymorphonuclear cells: interaction with fMLP-induced stimulation

We investigated the action of piracetam on human polymorphonuclear leukocyte (PMN) responsiveness in vitro. We first studied phosphoinositide metabolism and calcium release with and without fMLP (formyl-methionyl-leucyl-phenylalanine) stimulation. Piracetam at concentrations from 10(-4) to 10(-2) M induced a slight increase in inositol 1,4,5-trisphosphate (IP3) release and phosphatidylinositol 4,5-bisphosphate (PIP2) breakdown. At concentrations above 10(-3) M, piracetam sensitized PMNs to subsequent stimulation by fMLP used at subliminal concentrations (10(-9) and 10(-8) M), inducing a significant increase in IP3 release and PIP2 breakdown similar to that obtained with cells stimulated by the highest effective concentrations of fMLP (10(-7) and 10(-6) M). In the same way, piracetam greatly enhanced calcium release induced by weak concentrations of fMLP. However, piracetam had no effect on oxidative metabolism. We then studied the binding of (3H)fMLP to the PMN membrane in the presence of various concentrations of piracetam. We were not able to demonstrate an obvious action of piracetam either on receptor recruitment or on receptor affinity to fMLP. The difference between the actions of piracetam on phosphoinositide metabolism and calcium release on the one hand and oxidative burst on the other could be explained by an uncoupling of the triggering and activating effects of piracetam on PMNs. The enhancement by piracetam of intracellular cyclic AMP levels rapidly induced termination of the PMN response and accounted for the lack of effect on superoxide production. Thus, piracetam was able to modulate human PMN reactivity and in particular to exert a "priming effect" (rather due to structural modifications of the membrane), which might be of importance in infectious episodes given the absence of deleterious actions such as oxygen free radical production leading to tissue injury.

Drosophila P[Gal4] lines reveal that motor neurons involved in feeding persist through metamorphosis

Two P[Gal4] insertion lines in Drosophila melanogaster, MT11 and MT26, express GAL4 specifically in two to three pairs of pharyngeal motor neurons (PMN) in the suboesophageal ganglion. By using various secondary reporters, the architecture of the PMN, including their efferent axons in the pharyngeal nerve, was visualized. This allowed us to identify a pharyngeal dilator muscle as their target. To study the function of these neurons, we crossed line MT11 with a UAS-tetanus toxin gene construct (TNT-C) that inhibits all synaptic transmission. The offspring shows a reduction in food ingestion of 75% compared to the MT11 and TNT-C controls, demonstrating that PMN control food uptake. More important, lines MT11 and MT26 enabled us to follow PMN and their processes through metamorphosis, since labeling appears in the late third larval instar and persists up to adulthood. The motor axons innervate a pharyngeal muscle in the larva as well and extend through the maxillary nerve, proving that this nerve is homologous to the adult pharyngeal nerve. Efferent arborizations persist throughout metamorphosis, even though the larval muscle histolyzes by 20% of pupal life. Yet, some dedifferentiated structures remain, which may serve as a template for the formation of the adult muscle. Labeling of line MT26 with bromodeoxyuridine at embryonic or larval stages suggests that these neurons undergo their terminal mitosis in the mid to late embryo.

Dermaseptin, a peptide antibiotic, stimulates microbicidal activities of polymorphonuclear leukocytes

Dermaseptin (DRs S1), a 34-amino acid residue cationic antimicrobial peptide was studied for its effects on the production of reactive oxygen species (respiratory burst) and exocytosis of polymorphonuclear leukocytes (PMN). Treatment of PMN with DRs S1 (10-100 nM) stimulated significant production of reactive oxygen species (approximately a 2-fold increase relative to control) and release of myeloperoxidase. In addition, low DRs S1 concentrations (1-10 nM) primed the stimulation of respiratory burst induced by zymosan particles. In contrast to the native peptide, a dermaseptin fragment without either the COOH-terminal (DRs 1-10) or NH2 terminal (DRs 16-34) portion was inactive. The DRs S1-induced respiratory burst was inhibited by a selective protein kinase C inhibitor, GF 109203X, and was associated with early signalling events such as a rapid and transient elevation of cytosolic-free calcium concentration and phospholipase D activity. These data provide the first evidence of stimulating and priming properties of a peptide antibiotic on microbicidal activities of neutrophils, suggesting a potential role of dermaseptin in modulating host-defense mechanisms.

Mapping of the X-breakpoint involved in a balanced X;12 translocation in a female with mild mental retardation

Balanced chromosomal abnormalities such as translocations and inversions have been identified in many genetic diseases. Cloning of the breakpoints involved in these abnormalities has led to the identification of the disease-related genes. Recent reports suggest the presence of a mental retardation locus at Xq11-12. We have identified a female patient with a balanced translocation t (X;12) (q11;q15) associated with mild mental retardation. We identified a yeast artificial chromosome spanning the X-chromosome breakpoint by using fluorescent in situ hybridization techniques. A cosmid library of this YAC has been constructed and the search for candidate genes is in progress.

Larval chemosensory projections and invasion of adult afferents in the antennal lobe of Drosophila

We have studied the fate of olfactory afferents during metamorphic transformation of Drosophila melanogaster. Intracellular labeling of afferents from larval head chemosensilla suggests that the larval antennal lobe may be an olfactory target, whereas tritocerebral and suboesophageal centers are likely targets of gustatory sensilla. Application of monoclonal antibody 22C10 shows that the larval antennal nerve is the precursor of the adult antennal nerve and is used as a centripetal pathway for the adult afferents. Likely guidance cues are larval olfactory afferents that persist during early metamorphosis. P[GAL4] enhancer trap lines are introduced as efficient markers to follow the establishment of adult sensory projection. beta-Galactosidase and the bovine TAU protein were used as reporter proteins, and their expression patterns are compared. P[GAL4] lines MT14 and KL116 demonstrate that adult antennal afferents have arrived in the antennal lobe 24 h after pupariation and extend to the contralateral lobe 6 h later. Line MT14 expresses GAL4 mostly in basiconic sensilla and in certain trichoid sensilla, whereas KL116 is specific for trichoid and a small subset of basiconic sensilla. In the antennal lobe, largely complementary subsets of glomeruli are labeled by the two lines, in agreement with the observation that particular types of sensilla project to particular target glomeruli.

Effects of human low-density lipoproteins on superoxide production by formyl-methionyl-leucyl-phenylalanine activated polymorphonuclear leukocytes

Neutrophils play a major role in the host defence by producing reactive oxygen species. These products are liberated by activated cells and are known to cause endothelial cell injury and damage. The present study shows that low-density lipoproteins increase superoxide anion production by twofold in polymorphonuclear leukocytes stimulated by formyl-Met-Leu-Phe in vitro. Moreover, LDL induced a large increase in phosphoinositides and cytosolic-free calcium. Data from experiments performed on neutrophils treated with pertussis toxin, staurosporine, propranolol or niflumic acid suggest that modulation of phospholipase D and A2 activities could be involved in the modification by LDL of leukocyte response to formyl-Met-Leu-Phe. LDL lipid moiety could play a key role in their action on polymorphonuclear functions because cholesterol was exchanged between lipoproteins and cells that can modify membrane fluidity and interact with the formyl-Met-Leu-Phe receptor.

Effects of plasma lipoproteins on the production of superoxide anion by human polymorphonuclear leukocytes in vitro

Polymorphonuclear leukocytes (PMN) generate highly reactive oxygen derived free radicals that may cause lipoprotein lipid oxidation and so contribute to the pathogenesis of atherosclerosis. On the other hand it has been shown that lipoproteins can alter cell functions in vitro. We therefore studied the effects of atherogenic lipoproteins, VLDL and LDL, on the production of superoxide anion by human PMN in the presence or absence of formyl-methionyl-leucyl-phenylalanine (fMLP). VLDL and LDL stimulate PMN superoxide production and potentialize PMN stimulation by fMLP. The lipid moiety of the lipoproteins might be mainly involved in these effects. The binding of radio-labelled fMLP to its specific membrane receptor was significantly enhanced in the presence of VLDL and only slightly in the presence of LDL. The study of the signal transduction suggests that modulation of phospholipase D and A2 activities could be involved in the modification by LDL of PMN response to fMLP.

Expression of m1 and m4 muscarinic receptor mRNA in the striatum following a selective lesion of striatonigral neurons

Cholinergic stimulation has opposing effects on striatopallidal and striatonigral neurons. Most striatal projection neurons express m1 muscarinic receptor mRNA with m4 mRNA found in 40-50%. Expression of m4 mRNA is found in most preprotachykinin neurons but only a subset of preproenkephalin neurons, suggesting preferential localization of m4 receptors to striatonigral neurons. A volkensin lesion of striatonigral neurons reduced striatal m4 mRNA by 63% and m1 mRNA by only 18%, suggesting that preferential expression of m4 receptors by striatonigral neurons may contribute to their differential response.

Immunomodulatory effects of ornithine alpha-ketoglutarate in rats with burn injuries

OBJECTIVE

To investigate the influence of enterally administered ornithine alpha-ketoglutarate (OKG) on muscular amino acid content, eicosanoid release, and polymorphonuclear leukocyte responsiveness after induction of burn injury in rats.

DESIGN

Experimental trial.

MATERIALS AND METHODS

Four groups of rats were considered: (1) healthy rats that received a standard diet supplemented with 5 g/kg per day of OKG; (2) rats with burn injuries that received the same nutrition as group 1; (3) healthy rats that received standard diet supplemented with glycine in an isonitrogenous amount relative to OKG; and (4) rats with burn injuries that received the same nutrition as group 3. The thymus and 1 skeletal muscle were weighed. The oxidative metabolism of pleural polymorphonuclear leukocytes was measured by means of superoxide generation (O2-) and the chemiluminescent response to opsonized zymosan. Prostaglandin E2 and 6-keto-prostaglandin F1 alpha were measured in the supernatants of pleural and peritoneal cells.

RESULTS

The weights of the thymus and the muscle from healthy rats were similar. Those of rats from group 4 were significantly lower (P < .05), whereas those of rats from group 2 were not. Metabolism of OKG led to enhanced amounts of arginine and glutamine in skeletal muscle. The metabolic bursts of polymorphonuclear leukocytes from healthy rats were similar. Those of glycine-treated rats with burn injuries were significantly depressed (P < .05), whereas those of the OKG-treated group were not. Pleural and peritoneal cells from the rats with burn injuries that received OKG generated significantly more prostaglandins (P < .01) than did cells from the other groups of rats.

CONCLUSION

Ornithine alpha-ketoglutarate administered to rats with burn injuries displays immunomodulatory properties that can enhance host-defense mechanisms in animals that are affected by a severe injury.

Effect of encapsulation on the anti-inflammatory properties of superoxide dismutase after oral administration

Anti-inflammatory properties of free superoxide dismutase and superoxide dismutase encapsulated into liposomes, with or without ceramides, have been investigated. Two models were investigated: carrageenan paw oedema and pleurisy. Animals were fed by repeated doses, twice daily from day 1 until day 4. Evaluation consisted of measurement of paw oedema volume with determination of prostaglandin E2, thromboxane B2 and 6-keto-prostaglandin F1 alpha levels. Polymorphonuclear oxidative metabolism was evaluated by measurement of superoxide anion production. Levels of superoxide dismutase were determined in cells and pleural exudates. Higher anti-inflammatory effects were obtained after eight administrations of encapsulated forms (0.5 mg/kg) whereas free superoxide dismutase have shown no effects. Ceramides enhanced the results obtained.

In vitro effect of cetirizine on PGE2 release by rat peritoneal macrophages and human monocytes

Cetirizine was first described as a specific anti-H1 molecule displaying potent antiallergic activity. It was later found that its pharmacological properties extended to cellular actions as on eosinophil recruitment at inflammatory sites in allergic patients. Monocytes and macrophages participate in allergic mechanisms, particularly through high affinity H1 and H2 membrane receptors and generation of pro- and anti-inflammatory agents; among them histamine-induced factors, IL-1 and prostanoids are of importance. The aim of this work was to investigate the effect exerted by various concentrations of cetirizine (0.1-10 micrograms/ml) applied in vitro to human monocytes and peritoneal rat macrophages cultured for 24 h. Peritoneal macrophages were collected either from normal or experimentally inflamed rats. Human monocytes, isolated from peripheral blood, were studied either in a resting state or after stimulation by LPS from Escherichia coli (1 and 10 micrograms/ml). Cetirizine (10 micrograms/ml) significantly enhanced IL-1 release by human monocytes stimulated by a weak LPS concentration (1 microgram/ml) but could not modify the maximal increase of IL-1 release induced by 10 micrograms/ml of LPS. It did not exert any effect on resting cells. Cetirizine (0.1-10 micrograms/ml) enhanced PGE2 release by resting human monocytes. Concentrations of 1 and 10 micrograms/ml enhanced PGE2 release by LPS-stimulated monocytes, and by healthy and inflamed rat macrophages. This effect was concentration-dependent. Our findings point to an anti-inflammatory action of cetirizine via PGE2 release and histamine H2 interactions. Cetirizine did not directly modify IL-1 generation by resting monocytes but the IL-1 production observed after LPS stimulation could promote the mechanisms by which PGE2 is released.

Superiority of transesophageal echocardiography in detecting aortic arch atheromatous disease: identification of patients at increased risk of stroke during cardiac surgery

It has been shown that transesophageal echocardiography (TEE) is useful in evaluating atheromatous disease of the aortic arch and that such disease is a risk factor for stroke in medical patients. Data obtained by traditional methods of evaluating the aortic arch prior to cardiac surgery, namely, chest x-ray (CXR) and cardiac catheterization (CATH), were compared with that detected by TEE. Images of the descending thoracic aorta and aortic arch seen on intraoperative TEE in 258 cardiac surgical patients were graded as I = normal, II = intimal thickening or plaques < 5 mm thick or with a mobile component (severe disease). The aortic knob seen on CXR in 209 of these patients was graded as normal, < 1/2 or > or = > 1/2 ring of calcification. Calcification in the aortic root (graded as 0, 1+, 2+) and irregularities in the aortic lumen seen at CATH in 33 patients were also examined. Data were analyzed with respect to age, gender, type of surgery, and stroke. Increasing age correlated strongly with increasing severity of aortic arch and descending thoracic aortic disease seen by TEE. Severe disease was not present in patients under age 50 but was present in about 20% of those over age 70. Atheromatous disease was found by TEE in 55% of patients with a normal CXR and 91% of those with heavily calcified aortic knobs. Ischemic strokes occurred in seven patients. Severe arch disease correlated significantly with stroke (P < .01). Other variables did not correlate with stroke.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of niflumic acid on polyphosphoinositide and oxidative metabolism in polymorphonuclear leukocytes from healthy and thermally injured rats

Thermal injury in rats leads to an impairment of polymorphonuclear leukocyte (PMN) functions, particularly oxidative metabolism and phosphoinositide turnover. As prostaglandin E2, which has immunosuppressive properties, is released in high levels after burn trauma, we investigated the in vitro and in vivo effects of a nonsteroidal antiinflammatory drug, niflumic acid, on oxidative and phosphoinositide metabolism in PMNs from healthy and burned rats. Given the role of fluoride ions on PMN, the influence of niflumic acid was compared with that of sodium fluoride (NaF) at equivalent doses of F-. In vitro, niflumic acid and sodium fluoride had no effect on oxidative metabolism in stimulated by formyl methionyl-leucyl-phenylalanine (FMLP) or opsonized zymosan (OZ) or nonstimulated PMNs from healthy and burned rats. Niflumic acid slightly increased the production of inositol phosphate by nonstimulated PMNs from healthy and burned rats. Niflumic acid and NaF partly restored the stimulating effect of FMLP on inositol phosphate production by PMNs from burned rats. In vivo treatment with niflumic acid and NaF increased the oxidative metabolism of PMNs from burned rats but not healthy rats. Niflumic acid, more than NaF, restored the activity of both stimulants on phosphoinositide metabolism in PMNs from burned rats. In conclusion, at non-antiinflammatory doses, while inhibiting cyclooxygenase activity, niflumic acid exerts a complex effect on the burn-induced depression of PMN functions. The fluoride anion induces similar but generally weaker effects and seems to be involved in the restoring effects of niflumic acid on PMN functions in burned rats.

Effects of tripeptides derived from milk proteins on polymorphonuclear oxidative and phosphoinositide metabolisms

The tripeptide GLF (glycyl-leucyl-phenylalanine) was isolated from human milk proteins. This peptide increased phagocytosis by human and murine macrophages and protected mice against Klebsiella pneumoniae infection. Specific binding sites on human polymorphonuclear leukocytes (PMNs) have been demonstrated recently. The aim of the present research was to study the action of this peptide on rat and human PMN oxidative burst and to investigate the consequences of cell stimulation on polyphosphoinositide hydrolysis. A biphasic stimulating concentration-dependent effect of GLF on PMN chemiluminescence and superoxide anion generation was demonstrated. One of the peaks of the oxidative response occurred around 10(-9) M, which correlates with the Kd of high affinity receptors of GLF. The other maximum, around 10(-4) M, might be due to the hydrophobic nature of the tripeptide. O2- generation mimicked the phorbol myristate acetate response: after a lag period of 2-5 min, O2- release gradually increased for 10-15 min until a plateau was reached. Furthermore, GLF enhanced phosphoinositide breakdown with maximal IP3 production at 10(-7) M. Various analogs of GLF were synthesized in order to define the relative importance of the different amino acids and their position in the tripeptide molecule: glycyl-phenylalanine-leucine was devoid of biological properties but enhanced the activity of GLF on the metabolic burst at high concentrations; peptides leucyl-leucyl-phenylalanine and leucyl-leucyl-tyrosine, which displaced GLF from its specific membrane receptors, exerted stimulating effects on PMN oxidative and phosphoinositide metabolisms. It is quite conceivable that these short peptides, which may be generated in the newborn during digestion and which are able to stimulate phagocytic cells, are implicated in the defense of the neonate immature organism against infection.

Polyphosphoinositide metabolism in polymorphonuclear cells from healthy and thermally injured rats: effect of the immunomodulator RU 41740

Burn trauma is associated with alterations of various components of host defenses, including impaired neutrophil functions. In an animal model of experimental thermal injury, we studied if the modifications of cellular reactivity result from alterations in signalling systems by comparing polyphosphoinositide breakdown, particularly the production of inositol phosphates (IP, IP2 IP3), in healthy and burned rat polymorphonuclear neutrophil leukocytes (PMNs). Neutrophil activators such as N-formyl-methionyl-leucyl-phenylalanine (fMLP) and serum-opsonized zymosan increased in vitro production of inositol phosphates in PMNs from healthy rats. The immunomodulator RU 41740 had no effect by itself, but decreased the stimulating effect of fMLP and zymosan. In PMNs from burned rats, the stimulating effects of fMLP and zymosan were decreased, while RU 41740 stimulated inositol phosphate generation. In vivo treatment with RU 41740 inhibited the activation of phosphoinositide metabolism by fMLP or zymosan in healthy rat PMNs. Similar treatment of burned rats after injury restored the stimulating effect of fMLP and zymosan on inositol phosphate accumulation in PMNs. Thus, RU 41740 can modulate fMLP and zymosan receptor-mediated signal transduction, inducing an attenuation of the phosphatidylinositol hydrolysis response. After burn injury, when the activating effects of fMLP and zymosan are inhibited, RU 41740 can, on the contrary, stimulate phospholipase C-mediated polyphosphoinositide turnover and the formation of intracellular messengers such as IP3. These data show that RU 41740 has different effects on polyphosphoinositide metabolism in rat PMNs, according to the physiological and pathological state of the animals. Interestingly, it has a beneficial action on the post-burn decrease in PMN reactivity.

Eicosanoid release and early changes in two acute non specific inflammatory reactions. Major role of prostacyclin and leukotrienes

We have compared the early development (0-4h) of two acute non-specific inflammatory reactions induced by the intrapleural injection of isologous serum or a suspension of CaPP crystals. The intensity of the reactions was assessed in terms of the exudate volume, the number and ratio of pleural cells and different cell functions and secretions. The number of exudative cells elicited by isologous serum was higher than with CaPP but the PMN/Monocytes ratio was the same. The amount of protein in the serum-induced exudate was constant from 1 h to 4 h and was similar in the CaPP-induced pleural exudate at the latter time. The amount of complement increased similarly in the two models. The chemotactic potency of the exudates and cell supernatants following incubation showed similar values in the two models. Eicosanoid levels were higher in CaPP--than in isologous serum-induced exudates. Prostacyclin and peptidoleukotrienes were released in specially large amounts at the very outset of the inflammatory reactions.

Anti-inflammatory properties of a novel wound healing and immunomodulating agent, tetrachlorodecaoxygen complex (TCDO)

The first phase of the healing process is characterized by the development of an inflammatory reaction involving migration of inflammatory cells and release of inflammatory mediators. In a previous study, we have demonstrated that the water soluble tetrachlorodecaoxygen complex (TCDO), first synthetized to promote wound healing, inhibits polymorphonuclear (PMN) migration. The aim of the present study was to investigate the activity of TCDO on the progression of an acute non-specific inflammatory reaction, on the release of 6-keto-PGF1 alpha and PGE2 and on PMN oxidative metabolism in the rat. Injected in the pleural cavity, TCDO (15 mumoles/rat) significantly decreased the number of exudative cells while 1.5 mumoles/rat inhibited PMN oxidative metabolism ex vivo (assessed by chemiluminescent assay and measurement of O2- generation) after stimulation of the cells by opsonized zymosan. Similar observations were made in vitro after incubation of PMNs with various concentrations of TCDO (300 to 3 microM). The effect was dose-related and highly significant up to the concentration of 3 microM. In parallel, TCDO decreased the amounts of 6-keto-PGF1 alpha and PGE2 in exudates harvested 1 hour after the intrapleural injection of isologous serum. Effects were significantly different from control levels, from 1.5 to 0.03 mumoles/rat for 6-keto-PGF1 alpha and from 1.5 to 0.01 mumoles/rat for PGE2. This effect was observed when TCDO was injected at the same time or 1 hour before the isologous serum but not later. TCDO also inhibited LTB4 generation in vitro after PMN stimulation by calcium ionophore A23187, at concentrations up to 150 microM. The effects of TCDO in vivo and in vitro on rat PMN functions and inflammatory mediator release mimic certain activities of anti-inflammatory drugs. These properties may be beneficial in the very early stages of the wound healing process.

Local and systemic effects of an acute inflammation on eicosanoid generation capacity of polymorphonuclear cells and macrophages

Acute non-specific inflammation was induced in rats by injection of isologous serum into the pleural cavity. Pleural and peritoneal cells were collected at various times after pleurisy induction and tested for production of leukotriene B4 (LTB4), prostaglandin E2 (PGE2) and prostacyclin (PGI2) after in-vitro stimulation with calcium ionophore A23187. Cells obtained by lavage of pleural and peritoneal cavities of normal rats were used as controls. Increased production of LTB4, PGE2 and PGI2 by pleural cells was observed 3 days after pleurisy induction, but with a significant depression of PGI2 release at 3 h. As the relative proportions of polymorphonuclear cells (PMN) and macrophages in the inflammatory exudate varied during the development of inflammation, these cells were examined separately for LTB4 production. PMN and macrophages contributed equally to the liberation of this mediator in normal and inflamed rats. Similar qualitative and quantitative changes in LTB4 production by pleural cells were observed, irrespective of the type of irritant used (isologous serum, dextran, carrageenan, microcrystals). In contrast, intrapleural injection of saline had no significant effect. In order to determine whether local inflammation may influence mediator release by phagocytic cells at remote sites, peritoneal cells were collected 3 or 72 after pleurisy induction. The production of LTB4, PGE2 and PGI2 was increased at 72 h. Mediator production by peritoneal macrophages was observed in both normal and inflamed rats. In conclusion, acute non-specific inflammation provoked increased arachidonic acid metabolite generation by phagocytes both locally and at a distance: this occurred more than 24 h after pleurisy resolution.

Comparison of hetastarch to albumin for perioperative bleeding in patients undergoing abdominal aortic aneurysm surgery. A prospective, randomized study

The effects of hetastarch and human albumin solutions on perioperative bleeding and coagulation parameters during abdominal aortic aneurysm repair were compared. In two randomized groups of 20 patients, albumin 5% (group 1) or hetastarch 6% (group 2) 1 g/kg was given during surgery. The remaining perioperative fluids consisted of lactated ringers and packed red blood cells. Perioperative coagulation measurements included partial thromboplastin time, prothrombin time, activated clotting time, platelet count, and bleeding time. Estimated blood loss and the total amount of crystalloid and blood infused were also measured. The surgeon, blind to the colloid used, subjectively rated bleeding on a scale of 1 to 10. There was no significant difference between groups for any measured parameter at any time. Measurements of coagulation function were within normal limits for both groups. Hetastarch does not cause clotting disorders in patients undergoing abdominal aortic aneurysm repair, at least if the quantities used in this study are not exceeded.

2-(2-hydroxy-4-methylphenyl)aminothiazole hydrochloride as a dual inhibitor of cyclooxygenase/lipoxygenase and a free radical scavenger. 2nd communication: anti-inflammatory activity

The paper describes the topical anti-inflammatory activity of 2-(2-hydroxy-4-methylphenyl)aminothiazole hydrochloride (CBS-113 A), a dual inhibitor of cyclooxygenase/lipoxygenase and a potent free radical scavenger. When applied in eye drops (0.01 to 0.1% according to the model used), the drug inhibited inflammation in experimental conjunctivitis and uveitis induced by various procedures (e.g. paracentesis, endotoxin, S-antigen, albumin, Fe2+). The compound also inhibited leukocyte infiltration and histamine release when administered locally in pleural cavity with carrageenan. CBS-113 A could decrease plasma leakage induced by arachidonic acid or platelet activating factor in skin and airway, respectively. However, it was devoid of any activity when administered by systemic route. The compound appears as a potentially useful anti-inflammatory drug, in particular in ophthalmology and as an alternative to glucocorticoids, since it does not present the side effects of these steroids (e.g. worsening of herpetic keratitis).

Prostanoid release by macrophages at a distance from an inflammatory site

During the development of an acute inflammatory reaction induced in the rat pleural cavity by dextran, calcium pyrophosphate, saline or phosphate buffered saline, macrophages present at a distant site (peritoneal cavity) display an increased capacity to release prostanoids: prostaglandins, prostacyclin and thromboxane. Enhanced levels of 6-keto-PGF1 alpha were observed both in peritoneal lavages (experiments in vivo) and in macrophage supernatants after 24-h culture (experiments in vitro). TXB2 levels were mainly increased in peritoneal lavages and PGE2 in culture supernatants. In vivo, levels of prostanoids in the peritoneal cavity reached a maximum 24 h after the induction of pleurisy whatever the injected substance. In vitro, amounts of arachidonic acid metabolites were highest in supernatants of cultured peritoneal macrophages harvested 72 h after the pleural injection of dextran or CaPP. These results show that the regulation of macrophage functions is closely related to prostanoid production, especially the release of PGE2 and PGI2.

Substance-P-like levels in inflammatory exudates

Levels of SP-like immunoreactivity were assessed by enzyme immunoassay in exudates induced in the rat by intrapleural injection of either calcium pyrophosphate (CaPP) or carrageenan. SP-like levels increased during the first hour, up to approximately 2 ng/ml, and remained significantly higher than control values from 1 to 6 h after the induction of pleurisy by CaPP. With carrageenan as the irritant, SP-like levels rose during the first 4 h, up to 3 ng/ml, and remained significantly higher than control values from 4 to 24 h. In terms of the total volume of exudate induced by carrageenan, total amounts increased up to 8 ng/rat at 16 h after the beginning of the reaction. Our data demonstrate a detectable release of SP-like material in these pleural exudates and suggest its involvement in the inflammatory response, either directly, or through other mediators, or simply by acting on nociceptive fibers and inducing vascular changes.

The modulation of peritoneal macrophage chemiluminescence by acute pleural inflammation, prostanoids and cyclo/lipoxygenase inhibitors

The chemiluminescent (CL) response of peritoneal macrophages was suppressed by induction 4 h earlier of an inflammatory reaction in the pleural cavity which was negated by prior administration of indomethacin, ketoprofen and BW 755C. These changes were accompanied by a concomitant rise in peritoneal PGI2 levels which was abolished by drug pretreatment. In vitro treatment of normal peritoneal macrophages with PGI2 inhibited their subsequent CL response. Indomethacin and ketoprofen produced elevated CL of macrophages obtained from untreated controls in vitro which was blocked by the lipoxygenase inhibitor NDGA. BW 755C and NDGA in vitro strongly inhibited macrophage CL and partially inhibited CL in a cell-free system. Use of these drugs in vivo demonstrated that indomethacin and ketoprofen augmented the CL response of peritoneal macrophages while BW 755C had no effect. These results suggest the inflammatory process per se can modulate the functions of macrophages in parts of the body remote from the inflammatory site. Moreover this modulation may be under the control of the prostanoid system.

Bradykinin levels in inflammatory exudates

An enzyme immunoassay was used to measure the levels of bradykinin (BK)-like immunoreactivity in inflammatory exudates provoked by calcium pyrophosphate (CaPP) or carrageenin. BK-like immunoreactivity increased from 4 to 18 ng/ml in exudates provoked by CaPP and collected from 30 min to 3 h after induction of pleurisy. BK levels decreased progressively (from 16 to 3 ng/ml) in the samples collected at 4 and 6 h. BK levels did not increase in exudates provoked by carrageenin. Control samples of exudates provoked by CaPP but not treated with peptidase inhibitors [orthophenanthroline (OPH) or a mixture of EDTA-captopril-thioglycolic acid (ECT)] as well as samples containing one or the other peptidase inhibitors dissolved in saline, were also negative. The present results indicate that an increased production of kinins is detectable only in exudates induced by CaPP and not in those provoked by carrageenin. Our data also suggest that the kinins are rapidly metabolized, both in vitro (in the exudate sample) and in vivo (in the rat pleural cavity).

The modification of the oxidative metabolism of cells derived both locally and at distance from the site of an acute inflammatory reaction

During an acute nonspecific inflammatory reaction initiated in the pleural cavity by a nondiffusible stimulus (calcium pyrophosphate crystals), the oxidative metabolism, as measured by chemiluminescence and superoxide release, of cells harvested from both the inflammatory site and at points distant from it was studied. The oxidative metabolism of peritoneal macrophages, obtained from rats undergoing an inflammatory reaction (pleurisy), demonstrated a transient decrease in activity compared with the resident population when using both zymosan and phorbol myristate acetate as stimulants. This metabolic unresponsiveness induced by inflammation may be related to the concomitant changes in the levels of prostacyclin in the peritoneal cavity. It should be emphasized that the peritoneal cellular composition or number did not change during these events. On the other hand alveolar macrophages from inflamed animals showed no significant changes in their superoxide production or chemiluminescence compared to controls. The precise reason for these inflammation-induced changes is unknown; however the acute nonspecific inflammatory reaction was able to modulate the oxidative metabolism of cells not only at the site of inflammation, but at points distant from it.

Prostacyclin and thromboxanes in carrageenan-induced pleurisy in the rat

The cellular origin and kinetics of TXB2 and 6-keto PGF1 alpha in carrageenan-induced pleurisy has been studied. Maximum levels of these prostanoids occurred 1 hour after induction of pleurisy. Mononuclear cells initially present in the pleural cavity synthesized TXB2 and 6-keto PGF1 alpha from (14C) arachidonic acid. By contrast, PMN cells harvested 6 hours after the induction of inflammation did not produce 6-keto-PGF1 alpha. Selective inhibition of thromboxane synthetase with drugs in vitro and in vivo increased the formation of 6-keto-PGF1 alpha, the stable breakdown product of PGI2. This metabolic effect was parallel to an increase in the volume of exudate and in PMN migration. These results suggest that TXA2 seems to be implicated not only as a chemotactic agent but also as an antagonist of PGI2 vasodilator effects.