Cadmium accumulation and antioxidant responses in Sparus aurata exposed to waterborne cadmium.

Cadmium (Cd), a nonessential trace element, is rapidly accumulated by most living organisms and subsequently exerts its toxicity at different molecular levels. This study exposed gilthead sea bream (Sparus aurata) to waterborne 0.1 mg/l Cd for 11 days and investigated the Cd accumulation pattern, lipid oxidation, and response of antioxidant defences. At the end of the experiment, mean Cd concentrations in gills and liver, the organs most prone to metal accumulation, were 209.4 and 371.7 ng/g ww, respectively. Muscle did not show any Cd retention during the 11 days of exposure. In liver, the cytosolic fraction of the metal was chelated into the nontoxic form by metallothionein (MT), a specific Cd-inducible protein. Zn and Cu concentrations were not influenced by Cd exposure. Glutathione (GSH) concentrations and the antioxidant enzyme activities of GSH reductase and GSH peroxidase showed an overall decreasing trend. In addition, lipid and aqueous hydroperoxide levels did not show any significant variation. Oxidative stress indirectly generated by Cd seems to be compensated for by the different biochemical systems tailored to decrease cellular damage. In particular, the negative effects of Cd accumulation in tissues were probably counteracted by the induction of MT.

Association of angiotensin-converting enzyme inhibitor-associated angioedema with transplant and immunosuppressant use.

BACKGROUND: Immunosuppressants decrease circulating dipeptidyl peptidase IV (DPPIV) activity in transplant patients, and decreased DPPIV activity has been associated with angiotensin-converting enzyme (ACE) inhibitor-associated angioedema. One study has reported an increased incidence of ACE inhibitor-associated angioedema among transplant patients compared to published rates, while several case series report angioedema in patients taking specific immunosuppressant agents. OBJECTIVE: To test the hypothesis that transplant patients are at increased risk of ACE inhibitor-associated angioedema. METHODS: We assessed the proportion of transplant patients in 145 cases with ACE inhibitor-associated angioedema and 280 ACE inhibitor-exposed controls. We measured the relationship between case-control status, transplant status, and immunosuppressant use and circulating DPPIV activity. We also assessed the incidence of angioedema among consecutive patients who underwent renal or cardiac transplant and were treated with an ACE inhibitor. RESULTS: Transplant patients were significantly overrepresented among ACE inhibitor-associated angioedema cases compared to controls (odds ratio 18.5, 95% CI 2.3-147.2, P = 0.0004). Immunosuppressant use, chronic renal failure, seasonal allergies and smoking were also associated with ACE inhibitor-associated angioedema in univariate analysis. The association of transplant status with ACE inhibitor-associated angioedema was no longer significant after inclusion of immunosuppressant therapy in a multivariate analysis. Dipeptidyl peptidase IV activity was significantly decreased in sera from cases compared to ACE inhibitor-exposed controls, as well as in individuals taking immunosuppressants. Two of 47 ACE inhibitor-treated renal transplant patients and one of 36 ACE inhibitor-treated cardiac transplant patients developed angioedema. CONCLUSION: Transplant patients are at increased risk of ACE inhibitor-associated angioedema possibly because of the effects of immunosuppressants on the activity of DPPIV.

Interactive effects of fumonisin B1 and alpha-zearalenol on proliferation and cytokine expression in Jurkat T cells.

Mycotoxins are secondary metabolites of fungi that grow on various food and feed. These compounds elicit a wide spectrum of toxicological effects, including the capacity to alter normal immune function. Feed commodities are usually contaminated with more than one mycotoxin; however, extensive information on the interaction between concomitantly occurring mycotoxins and the consequence for their toxicity is lacking. In the present study, we examined the effects in vitro of fumonisin B1 (FB1) and alpha-zearalenol (alpha-ZEA), alone or in combination, on the immune function in the human lymphoblastoid Jurkat T cell line. Treatment of cells with increasing concentrations of FB1 resulted in a dose-dependent induction of proliferation. In contrast, alpha-ZEA showed a marked inhibitory effect on cell proliferation, even at very low doses, essentially mediated by apoptosis. In stimulated cells pre-incubated with FB1, the levels of IL-2 and IFN gamma mRNAs were similar to control whereas a reduction of cytokine transcripts was reported following alpha-ZEA treatment. Interestingly, co-administration of mycotoxins resulted in further inhibition of both proliferation and IFN gamma mRNA expression when compared with alpha-ZEA alone. In conclusion, FB1 and alpha-ZEA showed different immunomodulation abilities when individually administered. Combination of mycotoxins resulted instead in interactive effects.

Persistent organochlorine pollutants in liver of birds of different trophic levels from coastal areas of Campania, Italy.

Liver samples of 12 species of birds of different trophic levels, collected during the period 1998-2000 from coastal areas of the Campania region, Southern Italy, were analyzed for organochlorine pesticides (OCs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), gamma-hexachlorocycloexane (gamma-HCH), aldrin, dieldrin, endrin, and the seven PCB "target" congeners, IUPAC Nos. 28, 52, 101, 118, 138, 153 and 180. p,p'-DDE was present in all the samples analyzed, at concentrations ranging from 4 to 4504 ng/g wet wt, which were much higher than those found for HCB, dieldrin, and p,p'-DDD. The concentrations of the others OCs were below the detection limit in all the samples. PCBs were found in all the bird species at levels ranging between 6 and 8431 ng/g wet wt. The hepta-, hexa-, and penta-chlorinated congeners 180, 153, 138, and 118 were predominant since, in almost all the species, they contributed to more than 98% of the total seven determined PCBs. No significant differences in mean concentrations of organochlorine pesticides are detected between single species or between species grouped according to their feeding habits (p > 0.05). However, p,p'-DDE levels were higher in carnivorous species than in omnivorous and insectivorous ones (carnivorous > omnivorous > insectivorous). Concentrations of total PCBs were significantly higher in omnivorous birds than in carnivorous (p < 0.01) and insectivorous ones (p < 0.001), whereas carnivorous birds exhibited significantly higher total PCB levels than insectivorous ones (p < 0.01). Marked differences in total PCB concentrations were found also between single species (from p < 0.05 to p < 0.001). Levels of OCs and PCBs were generally below the thresholds known to affect reproduction, however, mean hepatic concentrations of total PCBs in the yellow-legged herring gull (Larus cachinnans), black-headed gull (Larus ridibundus), and kestrel (Falcus tinnunculus) were far higher than those estimated to elicit immunosuppressive effects and possibly increase susceptibility to parasitoses.

Cadmium, chromium and lead contamination of Athene noctua, the little owl, of Bologna and Parma, Italy.

A study was conducted to determine cadmium, chromium and lead concentrations in liver and brain of 52 little owls (Athene noctua) from two provinces of Emilia Romagna region, with the aim of furnishing indirect information concerning contamination of their habitat, also considering possible environmental dispersion of the metals. Metal analysis was performed by atomic absorption spectrophotometry with graphite furnace. Variance analysis with sampling area, gender and age shows that no statistical difference was found for gender, while a significant difference (P<0.05) was found for cadmium and lead, but not for chromium, when sampling areas and age were of concern. For all metals highest mean concentrations were found in liver (170 ppb for cadmium, 297 ppb for chromium and 312 ppb for lead). These levels can be considered as indicative of chronic exposure to low and "background" amounts of pollutants and they are of no toxicological concern, as they are always well below the toxic thresholds defined for each metal. The present study can be considered as a starting point for further analyses, aimed to the definition of any possible subtle effect (e.g. effects on enzymes activity) and of any possible correlation between levels of pollutants and appearance of possible adverse effects. It also furnished useful data for diagnostic cases and potentially for monitoring local contamination.

Innervation of equine airways.

Equine obstructive pulmonary disease (COPD), or heaves or recurrent airway obstruction, is a common equine pulmonary disease similar to human asthma and/or CODP. Since bronchospasm and inflammation are the key features in heaves, the purpose of this paper is to review the contribution of neural mechanism that may be relevant to this disease. Equine airway receive cholinergic and adrenergic innervation, as well as observed in many species. It was suggested that the autonomic neural control in asthma might be defective with an imbalance between excitatory and inhibitory pathways, resulting in excessively twitchy airways. Moreover, the recognition that, in addition to classical adrenergic and cholinergic pathway there are non-adrenergic-non-cholinergic inhibitory (iNANC) and excitatory (eNANC) innervation and many mediators, which have potent effects on airway function, has revived interest in neural control of airway.

Obesity does not induce abnormal CSF pressure in subjects with normal cerebral MR venography.

Obesity has been shown to increase lumbar CSF pressure in healthy subjects. The authors studied lumbar CSF opening pressure in 18 obese, 33 overweight, and 49 nonoverweight subjects with normal MRI and MR venography (MRV) of the brain. No subject had a CSF pressure above 200 mm H2O. Obesity does not cause abnormal CSF pressure in subjects with normal MRV. Individuals with a CSF pressure higher than 200 mm H2O should undergo MRV to exclude cerebral venous thrombosis.

Cerebral venous thrombosis and isolated intracranial hypertension without papilledema in CDH.

BACKGROUND: There is evidence that patients with chronic daily headache (CDH) may have isolated intracranial hypertension without papilledema (IHWOP). Recent studies have emphasized that isolated IH may be due to cerebral venous thrombosis (CVT). OBJECTIVE: To detect the occurrence of CVT in patients with CDH. METHODS: The authors investigated the occurrence of CVT in 114 consecutive patients with CDH by using MR venography (MRV). A portion of these patients underwent a lumbar puncture (LP) to measure CSF pressure. MRV and LP were also performed in 28 age-matched control subjects. RESULTS: In all the control subjects, both MRV and CSF pressure were normal. One hundred three of the 114 patients with CDH had normal MRV. Twenty-seven (Group 1) of these 103 patients underwent LP, and all of them had normal CSF pressure. Eleven (9.6%) of the 114 patients with CDH had CVT of one or both transverse sinuses. Six of these 11 patients had flowing abnormalities of one transverse sinus (Group 2), whereas the remaining five patients showed involvement of both transverse sinuses (Group 3). The CSF pressure of Group 2 was higher than that of either Group 1 or the control subjects, and one of the six patients showed isolated IHWOP. Patients of Group 3 displayed the highest CSF pressure, and four of five had isolated IHWOP. The headache profiles of patients with CDH and CVT did not differ from those of patients with CDH but normal MRV. CONCLUSIONS: CVT, as detected by MRV, occurred in 9.6% of patients who presented with CDH. Almost half of the patients with CVT had isolated IHWOP. These results suggest that MRV may be a useful tool for selecting patients with CDH who should have LP to exclude isolated IHWOP.

Effect of fumonisin B1 on inducible nitric oxide synthase and cyclooxygenase-2 in LPS-stimulated J774A.1 cells.

Fumonisin B1 (FB1) is a water-soluble fungal metabolite that elicits a wide spectrum of toxicological effects. Cellular targets of FB1 include immune cells and in particular macrophages. In the present study the cytotoxic effect of FB1 (1-100 microM) was evaluated using a murine macrophage cell line (J774A.1) as model system. The effect of FB1 on nitric oxide (NO) and prostaglandin E2 (PGE2) production induced by lipopolysaccharide (LPS, 10 and 100 ng/ml) was also investigated. Macrophages were pretreated with FB1 for 72 h and then stimulated with LPS for 24 h. The increase of LPS-induced production of these inflammatory mediators was observed at increasing concentrations of FB1 (0.1-10 microM) and was found to be concentration dependent. By western blot analysis we demonstrated that the observed increase of NO and PGE2 production by FB1 was related to an enhancement of iNOS and COX-2 expression.

Alkyltins in farmed fish and shellfish.

A study to update dibutyltin (DBT) and tributyltin (TBT) residues in farmed fish and shellfish (Mytilus edulis) was carried out 4 years after the adopting of the restricting regulation of the antifouling uses of organotins in Italy. DBT and TBT were simultaneously extracted from farmed fish and shellfish (M. edulis) and from free living specimens, used as control, purchased from retail stores or fishermen in the province of Naples (Italy), and detected using a capillary gas chromatograph equipped with a flame photometric detector (GC-FPD). Dosable amounts of DBT were found in the 10% of the farmed fish analyzed, ranging from 1 to 26 micrograms kg-1 wet wt (mean 10 micrograms kg-1) and in the 23% of the free living fish at an average level of 2 micrograms kg-1 wet wt (range 1-4 micrograms kg-1 wet wt). TBT was detected in 85% of the farmed fish, in concentrations varying from 2 to 260 micrograms kg-1 wet wt (mean 28 micrograms kg-1 wet wt) and in 46% of the free living specimens (mean 39 micrograms kg-1 wet wt; range 1-93 micrograms kg-1). All the mussel samples analyzed were polluted by both DBT and TBT. In the farmed mussels the average amounts of DBT and TBT were, respectively, 4 and 2 micrograms kg-1 wet wt; in the free living they were 4 and 5 micrograms kg-1 wet wt, respectively. The results indicate that the DBT and TBT contamination is as highly diffuse in farmed as in free living fish and mussels on sale in retail markets in Naples province even if the levels of the contamination are meanly quite low.

Immobilised echistatin promotes platelet adhesion and protein tyrosine phosphorylation.

Echistatin, a 5000-Da disintegrin, is a strong competitive inhibitor of platelet alpha(IIb)beta(3) binding to fibrinogen. In addition to its antiplatelet activity, echistatin also exhibits activating properties by inducing a switch of alpha(IIb)beta(3) conformation towards an active state. However, soluble echistatin, which is a monomeric ligand, provides only receptor affinity modulation, but it is unable to activate integrin-dependent intracellular signals. Since proteins may exhibit a multivalent functionality as a result of their absorption to a substrate, in this study we evaluated whether immobilised echistatin is able to stimulate platelet adhesion and signalling. The immobilisation process led to an increase of echistatin affinity for integrin(s) expressed on resting platelets. Unlike the soluble form, immobilised echistatin bound at comparable extent either unstimulated or ADP-activated platelets. Furthermore, echistatin presented in this manner was effective in stimulating integrin-dependent protein tyrosine phosphorylation. Platelets adhering to immobilised echistatin showed a pattern of total tyrosine phosphorylated proteins resembling that of fibrinogen-attached platelets. In particular, solid-phase echistatin induced a strong phosphorylation of tyrosine kinases pp72(syk) and pp125(FAK). Inhibitors of platelet signalling, such as apyrase, prostaglandin E(1), cytochalasin D and bisindolylmaleimide, while not affecting platelet adhesion to immobilised echistatin, abolished pp125(FAK) phosphorylation. This suggests that signals activating protein kinase C function, dense granule secretion and cytoskeleton assembly might be involved in echistatin-induced pp125(FAK) phosphorylation.

Decreased lipid fluidity of the erythrocyte membrane in dogs with leishmaniasis-associated anaemia.

In both man and the dog, anaemia resulting from natural leishmaniasis is often severe and mainly associated with a shortened life span of erythrocytes. Lipid fluidity of erythrocyte membranes from 17 dogs with anaemia caused by visceral leishmaniasis was investigated by means of fluorescence polarization. Results were compared with those from three groups of control animals (10 healthy dogs, seven dogs with visceral leishmaniasis but no anaemia, and 10 dogs with anaemia unrelated to leishmaniasis). Fluorescence polarization values recorded for animals with leishmaniasis-associated anaemia were elevated-indicating reduced erythrocyte membrane fluidity-and significantly higher than in the control groups. Mechanical sequestration by the spleen due to increased cell rigidity, or alterations in receptor/ligand erythrocyte cytoadherence mechanisms, or both, may result from decreased membrane fluidity and hence contribute to the anaemia of Leishmania -infected dogs.

H(2)O(2) activity on platelet adhesion to fibrinogen and protein tyrosine phosphorylation.

Platelets represent a target of reactive oxygen species produced under oxidative stress conditions. Controversial data on the effect of these species on platelet functions have been reported so far. In this study we evaluated the effect of a wide range of H(2)O(2) concentrations on platelet adhesion to immobilized fibrinogen and on pp72(syk) and pp125(FAK) tyrosine phosphorylation. Our results demonstrate that: (1) H(2)O(2) does not affect the adhesion of unstimulated or apyrase-treated platelets to immobilized fibrinogen; (2) H(2)O(2) does not affect pp72(syk) phosphorylation induced by platelet adhesion to fibrinogen-coated dishes; (3) H(2)O(2) reduces, in a dose-dependent fashion, pp125(FAK) phosphorylation of fibrinogen-adherent platelets; (4) concentrations of H(2)O(2) near to physiological values (10-12 microM) are able to strengthen the subthreshold activation of pp125(FAK) induced by epinephrine in apyrase-treated platelets; (5) H(2)O(2) doses higher than 0.1 mM inhibit ADP-induced platelet aggregation and dense granule secretion. The ability of H(2)O(2) to modulate pp125(FAK) phosphorylation suggests a role of this molecule in physiological hemostasis as well as in thrombus generation.

Possible anxiogenic effects of fenvalerate, a type II pyrethroid pesticide, in rats.

Pyrethroids are insecticides extensively used to control pests around houses as well as in agriculture. It has been suggested that type II pyrethroids may act on GABA receptors as benzodiazepine antagonists. Because benzodiazepines are used in anxiety, the present study was undertaken to investigate the possible anxiogenic effects of fenvalerate, a type II pyrethroid, in rats. Behavior in the open-field, social interaction, plus-maze behavior, and one-way passive avoidance were studied in rats orally treated with 1, 10, or 30 mg/kg fenvalerate. This pyrethroid reduced locomotion and rearing frequencies and increased immobility duration. Ten and 30 mg/kg of fenvalerate reduced social interaction, whereas the 1 mg/kg dose had no effect on this behavior. Fenvalerate administration did not change the plus-maze behavior of rats. Pretraining administration (1, 10, and 30 mg/kg) did not modify the behavior of rats during the training session of a passive avoidance task, while in the test session 10 mg/kg fenvalerate caused an increase in the crossing latency, and the 30 mg/kg dose reduced this parameter and increased the percent of animals crossing to the shock compartment. The behavioral alterations observed in this study suggest that fenvalerate has an anxiolytic effect on rats.

The mycotoxin fumonisin B1 inhibits integrin-mediated cell-matrix adhesion.

Fumonisin B1 (FB1), a mycotoxin produced by the corn fungus Fusarium moniliforme, causes a variety of animal diseases and is a suspected human carcinogen. The FB1 molecule bears remarkable structural resemblance to the long-chain sphingoid base backbones of sphingolipids. The toxicity and carcinogenicity of FB1 has been ascribed to its ability to inhibit ceramide synthase, a key enzyme in the metabolism of complex sphingolipids. In this study we have investigated whether the exposure of B16-BL6 mouse melanoma cells to FB1 affects cell growth and integrin-mediated cell matrix adhesion. Cell treatment with the highest tested dose (75 microM) of FB1 for 72 h induced an about 20% inhibition of cell growth. FB1 strongly affected B16-BL6 cell adhesion to immobilized fibronectin, by causing a dose-dependent inhibition of cell attachment to this substrate. FB1 also inhibited in a dose-dependent manner the adhesion of B16-BL6 cells to the immobilized anti-fibronectin receptor antibody, whereas it affected only to a low extent cell attachment to concanavalin A. Our results demonstrate that FB1 treatment alters integrin adhesive activity, thus affecting all cellular integrin-dependent functions.

Perinatal fenvalerate exposure: behavioral and endocrinology changes in male rats.

The effects of maternal exposure to fenvalerate during the prenatal and postnatal periods of sexual brain differentiation were studied in adult male offspring. Behavioral (open field, stereotyped, and sexual behaviors), physical (sexual maturation, body and organ weights), endocrine (testosterone levels), and neurochemical (striatal and hypothalamic monoamine and respective metabolite levels) data were assessed. The results showed that there was no change in the age of testis descent or testis weight, nor were there changes in monoamine levels or stereotyped behavior. However, there were significant reductions in ductus deferens and seminal vesicle weights and plasma testosterone concentrations. In addition, treated offspring showed decreased male sexual behavior and increased immobility in the open field. These results indicate that perinatal exposure to fenvalerate during the critical periods of male brain sexual differentiation has long-term effects on the reproductive physiology and behavior of male rats.

Nitric oxide regulatory role in sensitized guinea pig trachea.

Nitric oxide (NO) has been cited to play an important regulatory role in airway function. Moreover, the NO synthase expression in models of inflammation is documented. The aim of this study was to investigate, in vitro, the NO modulation of cholinergic responses in sham-sensitized and ovalbumin-sensitized guinea pig trachea by using L-arginine (L-ARG), a precursor of NO synthesis, and L-Ng-nitro-arginine-methyl-ester (L-NAME), an inhibitor of NO synthase. Our results showed that NO's ability to modulate cholinergic responses in ovalbumin-sensitized guinea pig trachea is lost. Indeed L-ARG and L-NAME modify acetylcholine sensitivity in sham-sensitized guinea pig but not in ovalbumin-sensitized guinea pig.

Evidence for non-adrenergic non-cholinergic contractile responses in bovine and swine trachea.

Non-adrenergic non-cholinergic (NANC) contraction of airway smooth muscle has been observed in some but not all animal species. The aim of this study was to investigate the NANC-contractile responses in bovine and swine trachea. Proximal and distal bovine and swine trachea were cut in strips and placed in 10 ml organ baths equilibrated in Krebs Henseleit (KH) solution and electrically stimulated (10 sec, 60 V, 2 ms, 4, 10 and 30 Hz). Contractile frequency response curves performed in the presence of the muscarinic antagonist, atropine (100 mM), the angiotensin converting enzyme inhibitor, captopril (1 microM) and the neutral endopeptidase inhibitor, thiorphan (1 microM), added 30 min prior to electrical field stimulation (EFS). In some tissues, incubated with atropine thiorphan and captopril, were also evaluated the effects of a pretreatment with capsaicin (10 microM) or a selective NK1 receptor antagonist, SR 14033 (100 nM) added to the baths 30 min prior to EFS. Bovine and swine proximal and distal tracheal preparations contracted in a frequency-dependent manner to EFS (4, 10 and 30 Hz). Some experiments were also performed with substance P (0.1 nM to 1 microM) in absence or in presence of SR 14033 (10 nM or 100 nM). At the maximum frequency tested (30 Hz), the contractile response elicited in bovine proximal and distal preparations was 194.5 +/- 17.1% and 229.7 +/- 24.1%, of ACh (100 microM), respectively. Similarly, the contractile response elicited by EFS (30 Hz) in swine proximal and distal preparations was 187.2 +/- 12.1% and 181.6 +/- 9.2% of ACh (100 microM), respectively. In tissues incubated with atropine, a significant decrease in smooth muscle sensitivity to EFS was observed (P < 0.05). When tissues were pretreated with captopril and thiorphan, a significant increase in the contractile response to EFS (30 Hz) was observed in all tested tissue preparations (bovine, proximal 210.1 +/- 14.4%, distal 264.3 +/- 16.2%; swine, proximal 199.3 +/- 14.9%, distal 206.3 +/- 16.2%, P < 0.05). In the presence of atropine, captopril and thiorphan a significant increase in the contractile response was observed in bovine and swine distal preparations compared with tissues incubated with atropine only (P < 0.05). These effects were antagonized by a pretreatment with a selective NK1 receptor antagonist, SR 14033. A pretreatment with capsaicin statistically (P < 0.05) enhanced EFS-induced contraction in all tested preparations respect to tissues incubated with atropine, thiorphan and captopril. Substance P induced a concentration dependent contraction of bovine and swine isolated tracheal preparations which was antagonized by a pretreatment with a selective NK1 receptor antagonist, SR 14033. No significant difference in the contractile potency (EC50) nor in maximum response (Emax) was observed to exogenously administered substance P between proximal and distal tracheal preparations. These data suggest that NANC contractile responses are present in bovine and swine trachea and are more evident in distal airways.