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Biomedical subjects

L Mantovani

Publications and source records attributed to L Mantovani.

At least 19 recordsLinked to original sources
PubMed2001

Velocity magnitude estimation with linear arrays using Doppler bandwidth.

The dependence of pulsed wave Doppler bandwidth on parameters typical of linear transducer arrays used in commercial Duplex and color flow mapping systems is investigated experimentally. For a single flow line it is observed that this bandwidth generally depends not only on the scatterer velocity and the beam-to-flow angle, but also on the flow line range and orientation. This is due to the fact that in Duplex and color flow systems the transducer is differently focused in the scan and elevation planes and its aperture and focal lengths are often made to vary, depending on the distance of the flow line from the transducer. It is however experimentally demonstrated that, at points where the ultrasound beamwidths in the scan and elevation planes are both comparable to the sample volume length, the Doppler bandwidth is independent of the beam-to-flow angle. It is also shown that this invariance can be extended to other ranges by appropriately modifying the array aperture. Finally, as an application of this independence, the flow-line velocity magnitude in these beam regions is estimated with better than 5% uncertainty through a simple bandwidth measurement.

Ultrasonics↗
PubMed2000

Treatment of anaemia in myelodysplastic syndromes with prolonged administration of recombinant human granulocyte colony-stimulating factor and erythropoietin.

Treatment with recombinant human erythropoietin (rhEPO) improves anaemia in approximately 20% of the patients with myelodysplastic syndromes (MDS). Recent reports suggest that a combination treatment with rhEPO plus recombinant human granulocyte colony-stimulating factor (rhG-CSF) given for up to 18 weeks may result in a higher erythroid response rate than with rhEPO alone. We investigated the potential advantage of an even more prolonged schedule of combined rhG-CSF and rhEPO treatment to obtain and maintain stable responses. In a phase II study, 33 patients with MDS [17 with refractory anaemia (RA), eight with RA with ringed sideroblasts (RARS), eight with RA with excess blasts (RAEB) with bone marrow blast counts less than 20%] were scheduled to receive at least 36 weeks of combined therapy with rhG-CSF and rhEPO. Seventeen of 28 evaluable patients demonstrated an erythroid response [61%; 95% confidence interval (CI) 41-78] after 12 weeks of treatment. The erythroid response rate was 80% (20 of 25 evaluable patients; 95% CI 59-93) after 36 weeks. Seven of these responses developed between week 12 and week 36, whereas two initially responding patients became refractory. The cytokine therapy was generally well tolerated. Nineteen of the 20 patients responding after 36 weeks continued to be treated with both cytokines. After 1 year and 2 years of continuous combined treatment, 50% of the initially included patients showed a continuing response. Our results suggest that a prolonged combination treatment with rhG-CSF and rhEPO is highly effective in achieving a stable and long-lasting erythroid response in many patients with MDS and low blast count.

Adult↗
PubMed1998

Baseline biophysical parameters in subjects with sensitive skin.

Sensitive skin has been described as a skin type showing higher reactivity than normal skin and developing exaggerated reactions when exposed to external factors. The stinging test, performed by applying lactic acid to the nasolabial fold and evaluating the intensity of subjective symptoms, is widely accepted as a marker of sensitivity and employed for the selection of subjects experiencing invisible cutaneous irritation. However, this test is based on self-perceived assessment and lacks objectivity. In order to contribute to the finding of objective descriptors, we assessed baseline biophysical parameters in subjects with sensitive skin by means of transepidermal water loss (TEWL), capacitance, pH, sebum and skin colour measurements, and compared the data with those obtained in normal subjects, also correlating the results with those of clinical assessments and functional tests. Subjects with sensitive skin showed a trend towards higher scores at all assessment times both for the stinging and the washing test. The skin of sensitive subjects was described as less supple, less hydrated and more erythematous and telangiectatic with respect to the skin of normal subjects. A trend towards an increase in TEWL, pH and colorimetric a* values, and a decrease in capacitance, sebum and colorimetric L* values on the face of subjects with sensitive skin was observable. However, significances were only present for capacitance and a* values. Thus, alterations of baseline capacitance values indicate the tendency to barrier impairment and support the view that skin hyperreactivity to water-soluble irritants is induced by a greater amount of irritants absorbed, whereas the increase in the erythema parameter shows that cutaneous vascular hyperreactivity in subjects with sensitive skin also corresponds to baseline vasodilation.

Adult↗
PubMed1997

Cross-sensitizations between azo dyes and para-amino compound. A study of 236 azo-dye-sensitive subjects.

Combined sensitizations to different azo dyes, probably based both on true cross-sensitization and on simultaneous positive reactions, have frequently been described. However, since azo dyes are included in the standard series in a minority of countries, the case studies considered comprise, with few exceptions, a small number of subjects. The aim of our study was to investigate cross-reactions between different azo dyes and para-amino compounds in azo-dye-sensitive subjects, to study the clinical aspects of azo dye dermatitis, to assess the relevance of sensitization to azo dyes, and to relate the pattern of cross-sensitizations to the chemical structure of the different dyes. Out of 6203 consecutively tested patients, 236 were sensitized to at least 1 of 6 azo compounds employed as textile dyes, included in our standard series. 107 subjects reacted to Disperse Orange 3 (DO3), 104 to Disperse Blue 124 (DB124), 76 to p-aminoazobenzene (PAB), 67 to Disperse Red 1 (DR1), 42 to Disperse Yellow 3 (DY3), and 31 to p-dimethylaminoazobenzene (PDAAB). Co-sensitizations to para-phenylenediamine were present in most subjects sensitized to DO3 (66%) and PAAB (75%), in 27% and 36% of DR1 and DY3-sensitive subjects, and only in 16% of subjects sensitized to DB124. Apart from the hands and the face, the neck and the axillae were the most frequently involved skin sites. Whereas the involvement of flexural areas was mainly connected with sensitization to DB124, in patients with hand dermatitis and in those working as hairdressers, sensitization to DO3 and PAAB was more frequent. Moreover, in the former patient group, a history of textile dye allergy was most frequently obtained. Out of 33 patients tested with an additional textile dye series, only 5 subjects reacted to anthraquinone dyes. Cross-sensitizations between azo dyes and para-amino compounds can partially be explained on the basis of structural affinities.

Azo Compounds↗
PubMed1997

Parallel intraindividual evaluation of the vasoconstrictory action and the anti-allergic activity of topical corticosteroids.

The human skin blanching assay is a well established method for ranking the efficacy of corticosteroids after epicutaneous application. Vasoconstriction is a pharmacological activity, which correlates well with the clinical efficacy, the intensity of skin blanching after a single application under occlusion corresponding, generally, to the clinical efficacy after repeated application without occlusion. However, in studies dealing with the comparison between the vasoconstriction assay and the evaluation of the clinical effects on inflammatory skin diseases, some exceptions to this correlation have been reported. Therefore, in a pre-clinical phase, it would be useful to combine the blanching assay with at least one anti-inflammatory assay. In the present study the blanching assay and the allergic contact dermatitis inhibition test were performed in parallel, in order to compare the two testing procedures in the same group of subjects, utilizing standardized study designs supported by objective means of evaluation. Three commercial preparations of corticosteroids containing clobetasol propionate (CP), clobetasone butyrate (CB) and hydrocortisone acetate (HA), respectively, were employed both to treat nickel-induced positive patch test responses on the volar forearms, and to perform a vasoconstrictor assay on normal forearm skin in 16 nickel-sensitized healthy volunteers. For evaluating skin blanching, we employed colorimetric measurements, whereas for the quantitative determination of the inhibition of the intensity of allergic patch test reactions, 20 MHz B-scanning supported by image analysis was used. Both colorimetric and echogenicity values enabled us to distinguish between the three corticosteroids (at the 17 h evaluation and the 64 h assessment, respectively). A fair correlation was noted between colorimetric and echogenicity values. Both testing procedures ranked the three corticosteroids in the expected order. Corticosteroid preparations should be compared using methods which allow different effects to be simultaneously monitored, without involving a high number of patients. We are proposing this double procedure for the parallel intraindividual evaluation of the vasoconstrictory action and the anti-allergic activity of topical steroids.

Administration, Topical↗
PubMed1997

Inhibition of elicitation of contact dermatitis in humans by mometasone furoate: evaluation by means of 20-MHz B scanning associated with image analysis.

BACKGROUND: Mometasone furoate (MF) is a new strongly lipophilic steroid which has an anti-inflammatory effect as evaluated by in vivo and in vitro studies. OBJECTIVE: The objective of the present study was to investigate the degree of inhibition of experimental allergic contact dermatitis induced by the treatment with MF. METHODS: The therapeutic effect was evaluated by an echographic method associated with image analysis. MF activity was compared to that of hydrocortisone acetate 0.5% (Cortaid Cream, Lachifarma), clobetasone butyrate 0.05% (Eumovate Cream, Glaxo) and clobetasol propionate 0.05% (Clobesol Cream, Glaxo), classified respectively as weak, moderately potent and very potent steroids. RESULTS: The different corticosteroid formulations employed for inhibiting experimentally induced contact dermatitis reflect the expected rank order of efficacy. CONCLUSION: MF behaves like clobetasol butyrate ranking as a moderately potent corticosteroid.

Administration, Topical↗