Aluminum impairs rat neural cell mitochondria in vitro

Exposure to aluminum has been reported to lead to neurotoxicity. Mitochondria are important organelles involved in maintaining cell function. This study investigates the effect of aluminum on mitochondria in rat neural cells. The ultrastructure of mitochondria was observed, and the cell death rate (CDR), reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and 3-[4,5demethyl-2-thiazalyl]-2,-5diphenyl-2H-tetrazolium bromide (MTT) were measured to investigate the effect of aluminum on the mitochondrial structure and its function in neural cells. Results observed from the mitochondrial ultrastructure show that aluminum may impair the mitochondrial membrane and cristae. Increased CDR, enhanced ROS, decreased MMP, and decreased enzyme activity in mitochondria were observed in the Al-exposed neurons (100 500 microM). The present study demonstrates that alteration in the mitochondrial structure and function plays an important role in neurotoxic mechanisms induced by aluminum.

The Role of Alteration of Glutamic Acid and Gaba in Learning and Memory Impairment of Rats Induced by Aluminum

Aluminum exposure has been reported to be related to learning and memory impairment. This study examines the role of aluminum in alterating amino acids of the cerebral cortex of rats. The Step-down type tests were performed to investigate the alteration of learning and memory of rats induced by aluminum. The amino acids in the cerebral cortex were detected by high performance liquid chromatography (HLPC). Results show that the amounts of aluminum in the cerebral cortex increased by 5.0mgAl3+/(Kg·BW) group and 10.0mg Al3+/(Kg·BW) group. In the Step-down type test, the EN1 increased significantly in the Al3+ 10.0mg/(Kg·BW) group. The latency shortened obviously and the EN2 increased significantly in the 10.0mg Al3+/(Kg·BW) group. The content of Glu (Glutamic acid) increased but the content of GABA (gamma-aminobutyric acid) decreased significantly in the 10.0mg Al3+/(Kg·BW) group. This present study shows evidence that the disorder of amino acid neurotransmitters system plays an important role in the impairment of learning and memory of rats induced by aluminum.

Inhibitory effects of cadmium on peripheral blood mononuclear cell proliferation and cytokine release are reversed by zinc and selenium salts

Zinc (Zn) and selenium (Se) exert regulatory activities on immune functions, while cadmium (Cd) is an immunotoxic agent. The object of this study was to detect effects of 10(-4), 10(-5), and 10(-6) M Cd sulphate, Zn sulphate, and sodium selenite, and their combinations on human peripheral blood mononuclear cell (PBMC) proliferation and IFN-gamma and TNF-alpha production. Only 10(-5) M Zn sulphate significantly enhanced spontaneous PBMC proliferation, which was unaffected by the other salts. At 10(-4) and 10(-5) M, Cd sulphate exerted a dose-response inhibitory action on phytohemagglutinin- (PHA-) stimulated PBMC proliferation and cytokine release, while 10(-4) M and 10(-5) M Zn sulphate and 10(-5) M sodium selenite induced a stimulatory effect on both proliferation and cytokine release; 10(-4) M sodium selenite enhanced only the PBMC proliferation; at 10(-6) M, none of the salts changed the PHA-stimulated immune activity. Moreover, 10(-4) and 10(-5) M Zn and 10(-5) M Se strongly upregulated IFN-gamma (a Th1 cytokine) release, even in presence of 10(-5) M Cd, and reduced the inhibitory effects of Cd on PBMC proliferation and TNF-alpha release. This study confirms that Zn and Se both strongly enhance cytokine release induced by mitogenic stimulation, showing also that Zn acts with a broader range of concentrations than Se. This suggests that dietary excess of Se may not have beneficial effects.

"In vitro" effects of different arsenic compounds on PBMC (preliminary study)

Aim of this investigation was to compare the effects of 10(-4) M and 10(-7) M As compounds on spontaneous and PHA stimulated PBMC proliferation and IFN-gamma and TNF-alpha release. The inhibitory effect of the 10(-4) M As salts was in the following order: momo-methyl-arsinous acic (MMAs(III)) > sodium arsenite (As(III)) > tetraphenyl arsonium chloride (As(V)) > sodium arsenate (As(V)) > potassium- and sodium-esa-fluorum arsenate (As(V)) > dimethyl arsinic acid (DMAs(V)), while monomethyl-arsonic-acid (MMAs(V)) and arsenobetaine did not exert immune effects. 10(-7) M MMAs(III) stimulated the spontaneous PBMC proliferation, while As(III) and DMAs(V) enhanced the PHA stimulated PBMC proliferation. This study shows that the immune effects of As salts depends on speciation; moreover, the immunotoxicity of inorganic arsenic in part depends on the intracellular bio-synthesis of MMAs(III) from MMAs(V).

Prevalence and risk factors for latex-related diseases among healthcare workers in an Italian general hospital

Latex allergy has become an occupational hazard among healthcare workers. Atopy and degree of exposure have been recognized as predisposing factors for latex sensitization. We investigated the prevalence of latex allergy and the potential risk factors for latex sensitization, by distributing a questionnaire to 284 employees of a general hospital in central Italy. We collected information about occupational history, including specific tasks performed; time of first exposure to latex gloves; number of pairs of gloves; and duration of daily exposure. We also investigated the interval between first exposure and onset of symptoms, as well as the exact circumstances of their appearance. We evaluated pre-existing rhinoconjunctivitis, asthma, atopic and contact dermatitis, and allergies to drugs and foods using prick and patch tests. Latex allergy was established by means of skin-prick test, specific IgE, patch-test, and latex-glove-wearing test. This survey documented a high prevalence of symptoms related to the use of latex (47%) among the hospital staff, demonstrable sensitization to latex was considerably lower (12%), though strongly associated to atopy and duration of occupational exposure. Despite non-specificity, validated questionnaires constitute the most useful means to implement health surveillance and prevention of latex-related diseases among healthcare workers.

Effects of resveratrol on lymphocyte proliferation and cytokine release

Resveratrol, synthesized in dietary plants and contained in wine, has been reported to play a beneficial role in certain cardiovascular regulatory mechanisms and to inhibit carcinogenesis by activating immune and inflammatory responses and apoptosis. The object of this study was to elucidate the "in vitro" effects of different concentrations of resveratrol (10(-4), 10(-5), and 10(-7) M) on human peripheral blood mononuclear cell (PBMC) proliferation and cytokine release. Spontaneous PBMC proliferation was unaffected by resveratrol, while the compound at 10(-4) M inhibited (69%) the PHA-stimulated PBMC proliferation. The proliferation stimulation index (ie, the ratio of PHA-stimulated PBMC proliferation/spontaneous PBMC proliferation) of cultures containing 10(-4) M resveratrol was very low in relation to the control, while the proliferation stimulation index values at 10(-5) and 10(-7) M were similar and slightly higher (without statistical significance), respectively. At 10(-4) M, resveratrol strongly inhibited PHA-stimulated IFN-gamma and TNF-alpha release from PBMC, but it did not cause inhibition at 10(-5) or 10(-7) M. The concomitant immune effects of resveratrol on PBMC proliferation and release of IFN-gamma and TNF-alpha may be explained by an inhibitory effect on transcription factor NF-kappaB. This study suggests that resveratrol, which is typically present in red wine at about 10(-5) M, is unlikely to cause inhibitory immune effects. However, a stimulatory effect of low concentrations of resveratrol on the immune system cannot be excluded.

Different effects of platinum, palladium, and rhodium salts on lymphocyte proliferation and cytokine release

The effects of graded concentrations of Pt, Pd, and Rh salts on spontaneous and PHA-stimulated peripheral blood mononuclear cell (PBMC) proliferation and IFN-gamma, TNF-alpha, and IL-5 release were the focus of this study. Spontaneous PBMC proliferation was inhibited by all 10(-4) M salts (with the exception of PtCl2), while it was enhanced by 10(-5) M PtCl2 as well as by 10(-5) and 10(-6) M (NH4)2[RhCl6] and RhCl3 (but not by 10(-7) M salts). Pt, Pd, and Rh compounds showed similar effects on PHA-stimulated PBMC proliferation and cytokine release; however, the effects on IFN-gamma release were stronger. Thus, 10(-4) and 10(-5) M (NH4)2[PtCl6] and 10(-4) M (NH4)2[PtCl4] inhibited the PHA-stimulated immune activity; 10(-4) M PtCl2 did not exert activity, while 10(-6) M (NH4)2[PtCl6] and 10(-5) and 10(-6) M (NH4)2[PtCl4] and PtCl2 enhanced PBMC proliferation and/or cytokine release. (NH4)2[PdCl6] showed stronger dose-related inhibitory effects (present also at 10(-7) M concentration) on PHA-stimulated proliferation and cytokine release than (NH4)2[PdCl4], PdCl2, or Rh salts; the inhibitory activity of (NH4)2[RhCl6] was slightly higher than that of RhCl3. In conclusion, this study shows that: (a) the immune capacity of Pt, Pd, and Rh depends on speciation; (b) low concentrations of Pt salts stimulate spontaneous and PHA-stimulated immune responses; (c) the in vitro activity of Pd compounds (which are only inhibitory) is higher than that of Pt and Rh salts. These findings are consistent with the observations that sensitization and allergic contact dermatitis in response to Pd are increased in the general population, although the roles of cross-sensitization to Pd and Ni are difficult to determine.

In vitro effects of platinum compounds on lymphocyte proliferation and cytokine release

In vitro immune effects of Pt compounds of occupational and/or environmental importance, or those used in cancer treatment were studied. Spontaneous and PHA-stimulated proliferation of peripheral blood mononuclear cells (PBMC) and in vitro release of TNF-alpha, IFN-gamma, and IL-5 were assessed in presence of high and very low concentrations of Pt salts: 10(-4) and 10(-7) M (NH4)2[PtCl6], (NH4)2[PtCl4], PtCl4, PtCl2, Na2PtI6, and cis-diaminedichloroPt (CisPt). Spontaneous and PHA-stimulated PBMC proliferation were both inhibited by 10(-4) M (NH4)2[PtCl6] and (NH4)2[PtCl4], while only PHA-stimulated proliferation was inhibited by 10(-4) M CisPt, without significant effects of the other Pt salts. TNF-alpha release from PBMC was reduced by 10(-4) M (NH4)2[PtCl6] and INF-gamma release was reduced by 10(-4) and 10(-7) M hexa- and tetrachloroplatinate and 10(-4) M Na2PtI6, but not by other Pt salts. IL-5 release (related to the Th2 immune response) was inhibited by 10(-4) M (NH4)2[PtCl6], (NH4)2[PtCl4] and Na2PtI6, but it was enhanced by both 10(-4) and 10(-7) M PtCl4. PtCl2 did not influence the immune effects. The study shows Pt salts have immune effects and their potency is ranked in the following order: (NH4)2[PtCl6] > (NH4)2[PtCl4] > Na2PtI6 and CisPt > PtCl4 > PtCl2. These results indicate that certain Pt salts affect lymphocyte proliferation and cytokine release. The intracellular mechanisms responsible for such effects have not been identified.

[Inflammation, bronchial hyperreactivity, and progression of asthma: a 5-year follow-up in grass sensitized farmers]

We studied in a group of 53 asthmatic farmers the influence of various treatment regimens on progression of disease, during five years follow-up. Specific immuno-therapy (SIT) and steroid treated patients showed significantly lower ECP levels and higher methacholine PD20 FEV1 than untreated patients, during all years of the study. During the first two years, spring ECP increase was higher in SIT treated patients than in steroid ones, however no significant differences were found during the following years. Bronchial hyperreactivity showed same course, except for a significant higher PD20 FEV1 in steroid and SIT treated asthmatics, in respect to the steroid or SIT alone. We may conclude that ECP and bronchial reactivity are useful for asthma monitoring and SIT and inhalant steroids have additional effects on asthma.

[Comparative in vitro study of various titanium compounds on the immune system]

The "in vitro" immune effects of different Ti compounds on peripheral blood mononuclear cells (PBMC) were determined. The results show that Ti dioxide is not immunotoxic; Ti oxalate is strongly immunotoxic; titanocene inhibits cytokine release but not PBMC proliferation, while Ti ascorbate inhibits TNF-alpha release from PBMC but not that of IFN-gamma. The results show that Ti toxicity depends on speciation.

[In vitro effects of hexavalent and tetravalent tellurium on immune functions]

The "in vitro" immune effects of K2TeO3xH2O (Te IV) and K2TeO4x2H2O (Te VI) on peripheral blood mononuclear cells (PBMC) was determined. Te(IV) inhibited PBMC proliferation and IFN-gamma, IL-5 and TNF-alpha release from PBMC more than Te (VI).

[Serum tryptase: marker of occupational anaphylaxis]

Tryptase is a protein released by mast cells, which is involved in the enhancement of inflammatory sequences in immune-mediated reactions. According with our experience, some patients having a reaction clinically classified as anaphylaxis, showed high levels of tryptase (> 20 ng/l) but also of serum specific IgE, showing the immune-mediated nature of the reactions. On the other hand workers without specific IgE and with low levels of tryptase probably had developed pseudoallergic (anaphylactoid) reactions. So, tryptase can be used as biomarker of occupational anaphylaxis and appear to be able to make out immune and nonimmune mediated reactions.

In vitro effects of nickel-sulphate on immune functions of normal and nickel-allergic subjects: a regulatory role for zinc

Nickel hypersensitivity represents a very common human disease state, mainly occurring in females, defined as allergic contact dermatitis. Ni is a transition metal whose activity may be modulated by congeners. Zinc, an essential component for living organisms, has been shown to counteract Ni effects in patients with Ni hypersensitivity. We analysed immune responses to both Ni and Zn in healthy subjects and patients with allergic contact dermatitis to Ni. Our in vitro results show that Ni modulates surface receptors expression, reduces phytohemagglutinin (PHA)-driven lymphoproliferation, and upregulates some proinflammatory cytokines production, including interferon (IFN)-gamma. Zn also induced CD4+ lymphocyte proliferation, but it abolished or reduced most Ni-mediated effects. Our data are consistent with the hypothesis that Zn and Ni, as part of the heavy transition metals, may exchange roles in immune-mediated phenomena leading to expression of allergic contact dermatitis.

In vitro effects of vanadate on human immune functions

Vanadium (V) is an element with wide industrial applications and environmental release. The object of this study was to determine the in vitro effects of high (10(-4) M) and low (10(-7) M) concentrations of sodium metavanadate (NaVO3) on cultured peripheral blood mononuclear cell (PBMC) proliferation, cytokine release, CD expression, and granulocyte O2- production. At 10(-4) and 10(-7) M, NaVO3 did not modify PBMC proliferation in the absence of phytohemagglutinin (PHA). On the other hand, 10(-4) M NaVO3 reduced by -25% the PBMC proliferation in PHA-stimulated cultures, with a significant reduction of the stimulation index (SI) of blastogenesis. Moreover, 10(-4 M NaVO3 significantly reduced the release of IFN-gamma by PHA-stimulated PBMCs, and 10(-7) M NaVO3 significantly enhanced the release of TNF-alpha. In addition, IL-5 release was significantly inhibited by high concentration of sodium metavanadate and significantly enhanced by low concentration of NaVO3. Neither 10(-4) nor 10(-7) M NaVO3 modified the expression of CD3+, CD4+, CD8+, or CD56+ in PHA-stimulated and unstimulated lymphocytes. Finally, 10(-4) M NaVO3 reduced the granulocyte production of O2- by about 70%, while 10(-7) vanadate reduced its production to a lesser extent. These results show that 10(-4) M NaVO3 exerts inhibitory effects on PBMCs, while at 10(-7) M it exerts a stimulatory action with a slight shift of the immune response towards a Th2-type response. This investigation suggests that environmental V can have important effects on the human immune system.

[Anxiety, life style and obstetric history of women working in a high-fashion clothing industry]

Women with a mean age of 38 years (range 20-62) were employed in an industry producing clothes of high fashion. A part of them (n = 210) performed their activities with hands and others (n = 90) utilising machines with more repetitive procedures. All the recruited women answered to a questionnaire including the state-trait anxiety inventory (STAI) test, working activities, lifestyle and obstetric history. There was no relation between obstetric history and working activities. The group of women with age ranging from 35 to 42 years showed the score of the STAI higher than that of the younger women and slightly lower than that of the subjects with older age. This may depend on the "healthy worker effect" in the old subjects able to continue their job. The scores of the STAI were also slightly influenced by the repetitive tasks utilising machines. On the whole, the working activity of women had beneficial effect on their role inside the family and in the social life.

Effect of natural allergen exposure on non-specific bronchial reactivity in asthmatic farmers

The aim of the study was to assess the seasonal variability of non-specific bronchial reactivity (NSBR) evaluated with methacholine in asthmatic farmers allergic to pollens. Twenty farmers (16 male and four female) with allergy to pollens, e.g. 'Graminae' and 'Parietaria', entered the study. None of the patients had been previously treated with specific immunotherapy. Patients underwent a methacholine challenge at the first visit and then in the subsequent seasons. Four groups of tests were obtained according to the period when the challenge was performed. Group 1: challenges performed in December, January and February; group 2 in March, April and May; group 3 in June, July and August; group 4 in September, October and November. PD20 values were expressed as the natural logarithm of the cumulative dose of methacholine causing at least a 20% fall in FEV1. Bronchial hyperreactivity was highest in summer, followed by spring and autumn; in winter it was much lower. Multiple group analysis (ANOVA) showed statistically significant differences between the groups (P < 0.01). When the groups were compared individually, statistically significant differences existed only between group 1 (winter) and each of the other groups, respectively 2 (spring) (P = 0.02), 3 (summer) (P = 0.004) and 4 (autumn) (P = 0.02). The results underlined the importance of allergic inflammation in determining changes in NSBR. In the region where the study was carried out (central Italy), the grass and Paretaria pollination lasts from March to November. Therefore, farmers had a progressive increase in NSBR from spring to summer and a decrease in fall as a consequence of the varying pollen concentration in different seasons. The level of allergen exposure is, in fact, the main factor that determines the severity of bronchial inflammation, thus affecting NSBR.

Effects of low frequency electromagnetic fields on expression of lymphocyte subsets and production of cytokines of men and women employed in a museum

The objective of this study was to analyse the immune response to electromagnetic fields (ELMFs) in seven men and eight women employed in a museum. The workers were exposed in a room to an ELMFs (range 0.2-3.6 microT and 40-120 V/m) induced by 50 Hz electricity for 20 h a week. Control groups consisted of 47 women and 39 men with a similar percentage of atopic subjects, age (range 30-51 years) and smoking habits of the workers included in the study. Levels of blood lead (Pb) and urinary trans-trans muconic acid, a metabolite of benzene (markers of exposure to traffic and smoking) of the control and exposed groups were similar. Lymphocyte subsets were determined in men and women using conjugated antibodies. Serum interleukin (IL) 4 and interferon gamma and their 'in vitro' production by peripheral mononuclear blood cells (PMBCs) stimulated by phytohemoglutinin (PHA), as well as blastogenesis of PMBCs induced by PHA, were determined in women only. ELMF-exposed women showed a significant reduction in the percentage of B and NK CD3(-)-CD25+ lymphocytes and a slight reduction of CD16(+)-56+ NK lymphocytes. They also showed significantly lower levels of interferon gamma in serum, or produced in the supernatants by PMBCs both spontaneously and stimulated by PHA, while they did not show significant changes in serum and 'in vitro' produced IL-4, or in blastogenesis of PMBCs. Men working in the museum showed, in relation to the controls, a statistically significant reduction in both number and percentage of CD16(+)- CD56+ and CD3(-)-CD25+ lymphocyte subsets. On the whole, this investigation demonstrates a reduction of blood NK lymphocytes and of the production of interferon gamma in workers exposed to low frequency ELMFs. Recent studies have shown that stress and poor lifestyle induce the reduction of blood cytotoxic activities possibly acting on nervous functions. This may suggest that ELMFs reduces blood NK lymphocytes by combined effects on the immune and nervous systems.

Seasonal variability of non-specific bronchial responsiveness in asthmatic patients with allergy to house dust mites

The aim of the study was to assess the seasonal variability of non-specific bronchial responsiveness to methacholine in allergic asthma. One hundred sixty-five patients (83 male and 82 female) entered the study: 86 subjects (group A) with allergy exclusively to mites and 79 (group B) with concomitant allergy to pollens, e.g., "Graminae" and "Parietaria." Inclusion criteria were the absence of sensitization to other allergens, no smoking habit, withdrawal from steroids, bronchodilators, sodium cromoglycate, and antihistamines for at least four weeks before enrollment, FEV1 > 70% of the predicted value, and absence of other respiratory diseases and of upper and lower respiratory tract infections for at least one month before the methacholine challenge. None of the patients had been previously treated with specific immunotherapy. Subjects of each group (A and B) underwent methacholine challenge at first visit and were divided into four subgroups according to the period when the challenge was performed. Subgroups A1 and B1 performed the challenge in December, January, and February; subgroups A2 and B2 in March, April, and May; subgroups A3 and B3 in June, July, and August; subgroups A4 and B4 in September, October, and November. PD20 values were expressed as the natural logs of the cumulative dose of methacholine causing at least a 20% fall in FEV1. Statistical analysis was carried out using multiple group analysis and Student's t-test. Results showed that the highest non-specific bronchial responsiveness was observed in autumn (ln PC20 = 4.54 +/- 1.51) in patients allergic to mites only (group A), and in summer (ln PC20 = 4.72 +/- 2.11) in those of group B. Multiple group analysis showed statistical significant differences between subgroups within each group (group A, p = 0.039; group B, p < 0.001). In patients allergic exclusively to house dust mites (group A), multiple comparisons and Student's t-test showed statistically significant differences between non-specific bronchial responsiveness (NSBR) assessed in autumn and those of other seasons (winter, p = 0.002; spring, p < 0.001; summer, p = 0.082). These results confirm that the level of allergen exposure may influence NSBR. Mite-allergic patients showed an increase of NSBR in autumn, possibly as a consequence of higher indoor mite concentration. However, mite- and grass-allergic patients had wider variations of NSBR, possibly reflecting changes in seasonal pollen concentration.

Catcholamine and nitric oxide systems as targets of chronic lead exposure in inducing selective functional impairment

Rats were exposed for ten months to 60 ppm of lead (Pb, as acetate) in drinking water to further assess cardiovascular effects of chronic Pb exposure. At the end of the treatment, mean blood Pb was 3.1+/-0.3 microg/dL in the control rats and 22.8+/-1.2 microg/dL in the Pb-exposed rats (means+/-SE, n=12 in each group); these values were not comparable to those of humans. Pb greatly increased plasma levels of noradrenaline (NA) and adrenaline (A), but not those of L-DOPA and dopamine; monoaminoxidase activity was augmented by Pb, mostly in the aorta and in the liver; the aorta, liver, heart and kidney showed discrete histopathological alterations in the Pb-exposed rats, in which plasma levels of nitric oxide (NO, determined as L-citrulline) were reduced. Pb was able to induce blood hypertension, resulting from increase of cardiac inotropism and, mostly, total peripheral resistance. These data were discussed also in relation to those obtained in our previous studies carried out in rats exposed to Pb in drinking water (15-60 ppm) for periods ranging from five to eighteen months. Pb appeared to increase both sympathetic nerve activity by central mechanisms (thus increasing plasma NA and A) and cyclic adenosine monophosphate (cAMP)-dependent availability of calcium ions (Ca++) for contractile mechanisms in the vascular and cardiac myocells (also through an increased vascular alpha2- and myocardial beta1-adrenoreceptor reactivity). The reduction of plasma NO, contributing to increase vascular resistance and cardiac inotropism, was explained as a result of actions of Pb on enzyme activities concerned with the kallikrein-kinin (KK) and renin-angiotensin-aldosterone (RAA) systems. It was concluded that chronic Pb exposure is able to affect selective neuroendocrine (i.e., catecholamine), au- tacoidal (i.e., KK and RAA) and transductional pathways (i.e., cAMP, NO, Ca++) involved in the cardiovascular function.

Influence of total IgE and seasonal increase of eosinophil cationic protein on bronchial hyperreactivity in asthmatic grass-sensitized farmers

BACKGROUND

This study correlates biomarkers of atopy (serum total and specific IgE) and inflammation (serum eosinophil cationic protein) with bronchial hyperreactivity assessed after the complete end of pollination, in a group of farmers suffering from grass-allergic asthma.

METHODS

A total of 28 asthmatic farmers, with allergy to grass pollen, reporting persistent asthma symptoms after grass pollination, were enrolled. An accurate allergologic screening excluded other sensitizations. Analysis of total and grass-specific IgE and eosinophil cationic protein was carried out before (March) and during (May) the following spring. After the complete end of pollination, bronchial hyperreactivity was assessed.

RESULTS

Symptoms (cough, wheezing) persisted during the autumn for a mean period of 41 days (range 13-69). Total IgE was moderately high and grass-specific IgE ranged from 9.25 to 41.12 kU/l without significant differences before and during spring. On the contrary, serum ECP levels significantly increased during the pollination period. PD20 methacholine evaluated after the end of grass pollination was negatively significantly correlated with levels of total IgE (r=-0.73; P<0.01) and the increase (from March to May) of serum ECP (r=-0.75; P<0.01). However, PD20 methacholine did not correlate with grass-specific IgE and serum ECP absolute values of both March and May. A positive correlation was found between number of postseasonal days with symptoms and both spring increase of serum ECP (r=0.75; P=0.04) and levels of total IgE (r=0.76; P<0.01). The number of postseasonal days with symptoms inversely correlated with postseason PD20 methacholine (r=-0.76; P<0.01).

CONCLUSIONS

The study demonstrates that in grass-sensitized farmers with asthmatic symptoms persisting for several weeks after grass pollination has ceased, the degree of airways hyperreactivity and the duration of postseasonal symptoms are directly related to the spring increase of ECP levels, as well as to the level of total IgE in serum. This allows us to identify two candidate biomarkers for the risk of developing prolonged asthma symptoms, and for the effective monitoring of anti-inflammatory treatment and allergen-specific immunotherapy.

Lymphocyte subset changes in blood and gastrointestinal mucosa after oral nickel challenge in nickel-sensitized women

This study investigates lymphocyte subsets in both the gastrointestinal mucosa and blood, in patients with nickel allergic contact dermatitis, after 10 mg oral nickel challenge (double-blind, placebo-controlled). 6 such patients with cutaneous symptoms induced only by skin contact with nickel (group A), 6 with a flare-up of cutaneous symptoms after food nickel ingestion (group B) and 6 healthy controls (group C) were enrolled. Blood lymphocyte subsets (CD4, CD45RO, CD8) were analyzed before and after 4 and 24 h from the challenge (test 1, 2, and 3), and intestinal biopsies were performed 2 days later. Challenges were positive in group B and negative in group A and controls. Serum and urine nickel levels significantly increased after nickel ingestion, with no differences between the 3 groups. At test 3, a significant decrease of the all CDs studied was found in group B. Biopsies of this group showed higher levels of CD45RO+ cells in the lamina propria and in the epithelium and lower levels of epithelial CD8+ lymphocytes. This study confirms that ingested nickel may induce flare-up of cutaneous reactions in some nickel-allergic patients, independently of the degree of sensitization and the intake of metal. In these patients, oral nickel stimulates the immune system, inducing maturation of T lymphocytes from virgin into memory cells; these latter cells seem to accumulate in the intestinal mucosa. The immunoreaction also involves CD8+ cells, whose role is not yet clear.

Lymphocyte subpopulations, cytokines and trace elements in asymptomatic atopic women exposed to an urban environment

This study evaluates the immune response to exposure to an urban environment from 30 non-atopic and 30 non-symptomatic women with history of respiratory and/or cutaneous allergies. Blood lymphocyte subsets and serum interleukin (IL) 4 and interferon gamma (INF-gamma) of the two groups were similar, while serum IgE and "in vitro" production of IL-4 and INF-gamma by mononuclear blood cells of the atopic women were higher spontaneously or in the presence of PHA, respectively. Blood lead of the nonatopic women (mean 55 microg/l) was positively correlated with CD4+-CD45RO-, CD3+-CD8+ and CD3--HLA-DR+ lymphocyte subsets, while urinary trans-trans muconic acid (a metabolite of benzene) of both groups of women (mean about 50 microg/l) was significantly correlated with NK CD16+CD56+ lymphocytes. Urine chromium of the non-atopic subjects was significantly correlated with activated T, B and NK HLA-DR+ cells. Urine nickel of both groups of women was correlated with CD4+-CD45RO+ "memory" lymphocytes and their ratio with CD4+-CD45RO- "virgin" lymphocytes suggesting that the metal enhances maturation of "virgin" into "memory" lymphocytes. On the whole, this study demonstrates that exposure to low levels of toxic agents, produced by vehicular traffic in an urban environment, exerts effects on immune functions of women.

A seroepidemiological study of toxoplasma gondii infection in children of northern Greece

The aims of this study were to determine the incidence of toxoplasmosis in children ofthe northern Greece region through the evaluation of serologic examination. Sera of 486 children, aged between 6 months and 15 years, suffering from different clinical entities, were tested for anti-Toxoplasma gondii specific IgG antibodies, using an ELISA (enzyme linked immunosorbent assay) technique. In this survey, a high percentage (11.1 percent) of the hospitalized children reacted positively to this method. Males and females had equal prevalence, 11 percent and 11.2 percent, respectively. Seropositivity rate was higher in children aged between 6 and 10 years old. In conclusion, our results indicate toxoplasma infection is an important public health problem affecting children and adolescents in northern Greece. We believe that the study described here could be considered for inclusion in existing national screening programs for hospitalized children.