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Biomedical subjects

P Falagiani

Publications and source records attributed to P Falagiani.

At least 19 recordsLinked to original sources
PubMed1998

Lymphoproliferative disease in human peripheral blood mononuclear cell-injected SCID mice. IV. Differential activation of human Th1 and Th2 lymphocytes and influence of the atopic status on lymphoma development.

Intraperitoneal transfer of PBMC from EBV+ donors into SCID mice leads to high human Ig levels in mouse serum and B cell lymphoproliferative disease. As these events depend on the activation of coinjected human T cells, we addressed the behavior of the Th1 and Th2 subsets in this model. Production of IFN-gamma, but not of Th2 cytokines such as IL-4, was detected in culture supernatants of PBMC stimulated in vitro with mouse splenocytes. Moreover, anti-CD3 stimulation of the human cells recovered from mice brought about IFN-gamma, but not IL-4, synthesis; on the other hand, PCR and in situ hybridization analysis of ex vivo-recovered cells disclosed the presence of mRNA for both cytokines following in vitro restimulation, thus suggesting posttranscriptional regulation of IL-4 gene expression. When SCID mice were inoculated with PBMC from atopic donors, whose Th1/Th2 profile displays an imbalance toward Th2 cells, tumor development rates were lower, and tumor latency was higher, compared with those in mice injected with PBMC from normal donors. Isotypic analysis of human Ig in mouse serum showed the exclusive presence of IFN-gamma-driven IgG subclasses; in addition, human IgE were low or undetectable in most cases. These findings indicate that following transfer into SCID mice, human Th1 lymphocytes undergo preferential activation, whereas Th2 function is down-regulated. Th1 lymphocytes probably are a major component in promoting EBV+ B cell expansion and tumor development; the individual Th1/Th2 profile could in part account for the as yet unexplained donor variability in tumor generation in this experimental model.

Adult↗
PubMed1998

Dot immunobinding assay for detection of mite antigens in house-dust samples.

A new test was developed specifically to detect mite antigens in house-dust. It uses a nitrocellulose dipstick spotted with specific antimite antibodies that act as a capture matrix; the same antibodies act as a detecting reagent when conjugated with colloidal dye particles. Aclotest is a 1-step assay, where a spotted dipstick is placed in a tube containing the detecting reagent and the house-dust sample. No instrumentation or previous extraction procedure of the sample is required, and the test response is visible as a colored spot, after 1 h incubation. The sensitivity and specificity of the new test were compared with those of Acarex and Der p1/Der f1 ELISA tests.

Animals↗
PubMed1997

Absorption and distribution kinetics of the major Parietaria judaica allergen (Par j 1) administered by noninjectable routes in healthy human beings.

BACKGROUND AND OBJECTIVE: The clinical effectiveness of noninjectable routes for specific immunotherapy has been demonstrated in many studies, but no data are available on the kinetics of allergens administered by these routes. Therefore we studied the kinetics of the radiolabeled purified major Parietaria judaica allergen (Par j 1) after sublingual, oral, and intranasal administration to healthy human beings. METHODS: After tracer administration (10 to 12.5 microg of Par j 1 labeled with iodine 123) to nonallergic volunteers, scintigraphic images were recorded at various times. Blood samples were also obtained at serial intervals to evaluate the absorption and distribution of radioactivity in plasma and to identify circulating radioactive species by molecular exclusion gel chromatography. RESULTS: When the sublingual route was used, no circulating radioactivity was detected until the tracer was kept under the tongue. The labeled allergen was rapidly degraded and absorbed in the gastrointestinal tract after swallowing. Plasma radioactivity peaked at about 1.5 to 3 hours and was mostly represented by free radioiodine and small radiolabeled peptides. Some activity not caused by free 123I remained associated with the oral mucosa up to 18 to 20 hours after administration. When the oral route was used, the results were similar to those observed after swallowing the sublingually administered allergen but without any persistence of the tracer in the mouth. When the intranasal route was used, the pattern of plasma radioactivity mimicked that of the sublingual and oral routes, with absorption of activity from the radiolabeled allergen occurring in the gastrointestinal tract after transport to the pharynx by mucociliary clearance. A relevant fraction of the tracer was retained on the nasal mucosa up to 48 hours after administration. CONCLUSION: The data in this study provide the first experimental basis for exploring the in vivo kinetics of allergen administered through noninjectable routes for specific immunotherapy in human beings.

Abdomen↗
PubMed1997

Pharmacokinetics of allergens after local administration.

The authors review the status of knowledge on absorption and kinetic of allergens administered on nasal mucosa. Intranasal administration is well known in pharmacology, and has been used for a long time for peptide drugs, mainly hormones. The immunological response to intranasally administered antigens have been studied in some experimental models: bovine Rnase, dextran, KLH, tetanus toxoid. These studies showed in atopic people a greater absorption of antigens by nasal mucosa compared to normal individuals, a difference that might be of importance in the pathogenesis of atopic diseases. The absorption rate of peptides through nasal mucosa has been studied biologically by PK-test with Rnase and peanut allergen, and a consistent passage of intact molecules has been observed. Using as tracer 125I-labelled human albumin, transport across the nasal mucosa has been demonstrated in 3/9 normal subjects, 1/9 patients with extrinsic asthma and 9/10 patients with atopic rhinitis. In experimental animals (rabbits) the passage of allergens through the nasal mucosa has been confirmed using 125I-labelled Parietaria allergens that showed a peak in the bloodstream 60 min after administration. It is concluded that peptide molecules such as allergens can be absorbed through the nasal mucosa and reach the bloodstream, and that in atopic patients nasal permeability is enhanced.

Administration, Intranasal↗
PubMed1997

Long-term follow-up of nasal immunotherapy to Parietaria: clinical and local immunological effects.

BACKGROUND: Local nasal immunotherapy (LNIT) with extracts in powder has been demonstrated clinically effective and devoid of side-effects in several controlled trials; nevertheless, no data concerning the long-term effects of LNIT are presently available. METHODS: In a recent double-blind, placebo-controlled study of LNIT to Parietaria pollen we observed, by means of specific nasal provocation test (SNPT) that LNIT is able to modify the local allergic inflammatory response. In the present study we followed up the same patients in open fashion for 2 further years. RESULTS: The results confirmed the clinical efficacy of LNIT and showed that it is strictly dependent on pre-seasonal administration: in fact, after LNIT discontinuation a clinical relapse was observed. A certain long-lasting protective effect on SNPT parameters (nasal symptoms and neutrophils infiltration) was also observed, whereas an increase of eosinophils count and ICAM-1 expression on nasal epithelial cells appeared as possible markers of clinical relapse. CONCLUSION: The present study suggests that pre-seasonal LNIT can be taken in consideration in selected subjects as prophylactic treatment for pollen-induced rhinitis. In addition, the results obtained provide informations about the duration of clinical efficacy and add data about the local allergic inflammation and its modulation.

Administration, Intranasal↗
PubMed1997

[Subcutaneous human dirofilariasis].

After a short review of the literature, starting from the last decades of the past century, the current classification of the Dirofilaria genus is shown with its two subgenera: D. immitis and D. nochtiella (repens, tenuis and ursi). The first case of subcutaneous and pulmonary dirofilariasis caused in Italy by D. repens is then shown as well as a research on dog populations in which D. immitis is prevalent. The fact that D. immitis has not yet been isolated in humans, in Italy, is probably due to D. repens vectors being more anthropophile. Finally, the latest cases of dirofilariasis from D. repens reported in Italy are taken into consideration along with the one isolated by the Authors, complete with illustrations. The case presented has been diagnosed on the basis of the histological examination carried out on a soft nodule detected in the right pectoral region; furthermore, eosinophilia and an elevated value PRIST were present.

Adult↗
PubMed1996

Local nasal immunotherapy with extract in powder form is effective and safe in grass pollen rhinitis: a double-blind study.

BACKGROUND: Local nasal immunotherapy has been studied, by means of an extract in powder form, in patients with allergic rhinitis caused by grass pollen. METHODS: Thirty-two patients allergic to grass were studied for 37 weeks in a double-blind controlled trial. Subjects were selected on the basis of a positive history, skin test result, RAST finding, and result of intranasal challenge to grass pollen. Two 16-patient groups were randomly assigned to active or placebo treatment. The treatment lasted 26 weeks (14 for the build-up phase, 12 for the maintenance period). RESULTS: No significant differences were observed in nasal symptoms during the treatment. During the pollen season the mean weekly symptom and medication scores were significantly lower in the treated group, compared with the control group, even considering each allergic symptom separately. Moreover, only in the treated group was a significant increase of specific nasal threshold to grass pollen observed after treatment. CONCLUSIONS: This study indicates that local nasal immunotherapy with allergen in powder form can be a suitable alternative to the traditional subcutaneous immunotherapy in terms of clinical efficacy and safety in grass-allergic rhinitis.

Administration, Intranasal↗
PubMed1996

Comparison between outdoor and indoor airborne allergenic activity.

BACKGROUND: Allergenic pollens are usually detected in outdoor air by using volumetric spore traps, which allow measurement of atmospheric concentration as pollen grains per m3 of air. The results of the pollen count are useful primarily for outdoor environments while most people spend most of the day indoors. OBJECTIVE: The purpose of our study was to compare outdoor pollen levels with allergenic activity measured both outdoors and indoors. METHODS: We used a Lanzoni spore trap to measure airborne Urticaceae pollen and filters collecting particles simultaneously indoors and outdoors and assayed each filter for Parietaria judaica allergenic activity. Samples were collected at the Allergological Service of the "A. Cardarelli" Hospital in Naples with the balcony open on some days and closed on others. Allergenic activity (ng/m3) was measured using the immunocapture RAST. RESULTS: With the balcony open there was no great difference between outdoor and indoor allergenic activity, but with the balcony closed there was a reduction of indoor allergenic activity of about one-third in comparison with outdoor allergenic activity. Statistical analysis (Pearson correlation test) indicated a significant correlation between outdoor allergen levels and indoor allergen levels with the balcony open (r = .4415, P < .05), but not with the balcony closed (r = .3160, P > .05); a significant correlation between outdoor pollen count and indoor allergen levels with the balcony open (r = .4809, P < .05), but not with the balcony closed (r = .3858, P > .05); and a highly significant correlation (r = .5225, P < .001) between outdoor pollen count and outdoor allergen levels. CONCLUSIONS: These data provide scientific evidence for the recommendation to hay fever patients to remain indoors during seasons with high levels of outdoor pollens.

Air Pollutants↗