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Biomedical subjects

R Valsecchi

Publications and source records attributed to R Valsecchi.

At least 55 records · Page 3Linked to original sources
PubMed1991

The loss of contact sensitization in man.

Little is yet known about the duration of contact sensitivity, but frequent exposure of a target to allergen seems to reduce skin reactivity. The aim of this study was to study the persistence of a specific contact sensitivity in 66 patients with alopecia areata, previously sensitized to DNCB (31 patients) and SADBE (35 patients) between 1978-1985. Patch tests were performed with 0.020 ml of different concentrations of DNCB or SADBE in acetone (0.05%, 0.10%, 0.20%, 1%). The results were read in a standardized manner. Of 66 patients, 47 (71%) had positive reactions and 19 (29%) negative. 8 of the 19 negative patients had been treated with DNCB, 11 with SADBE. Approximately 1/3 of the patients previously sensitized had lost their original sensitivity, and this did not seem to be time-dependent. This phenomenon seemed to be clinically correlated because the majority of the patients were from the "low responders" group. We think that acquired unresponsiveness to topical antigen in man is a possible phenomenon, but that it occurs more rarely than in mice and guinea pigs.

Administration, Topical↗
PubMed1990

Thiopental efficacy in phenobarbital-resistant neonatal seizures.

The successful treatment with thiopental (10 mg/kg, i.v.) of 9 severely asphyxiated newborns, under artificial ventilation, with neonatal seizures resistant to phenobarbital, is reported in this pilot study. The clinical and electroencephalogram control of seizures was prompt and resolute. No adverse effect on cardiovascular function (heart rate, blood pressure) was observed. The terminal half-life of thiopental averaged 9 h, the total plasma clearance 0.20 l/h/kg, and the steady-state volume of distribution 3.6 l/h/kg. The kinetic profile of the drug compared to phenobarbital and phenytoin in newborns suggests that its action is quicker and shorter lasting. Thus, from these findings, thiopental may offer a useful and handy approach for the safe and effective treatment of phenobarbital-resistant neonatal seizures.

Drug Evaluation↗
PubMed1989

Supranormal von Willebrand factor multimers in scleroderma.

Platelet adhesion-aggregation reactions play an early and pivotal role in the pathogenesis of systemic sclerosis in scleroderma, but the mechanisms are incompletely understood. We determined whether or not plasma from 11 consecutive patients with scleroderma contained a subset of larger than normal ("supranormal") multimers of von Willebrand factor (vWF) that are potent inducers of platelet aggregation and adhesion. Supranormal multimers were found in all patients on at least one of two different occasions 9 to 12 months apart, whatever the duration and severity of the disease, but in none of the normal controls. Administration of low-dose aspirin (40 mg) to five of the 11 patients for ten days to inhibit the platelet release reaction slightly reduced the amounts of supranormal multimers suggesting that they might originate in part from platelets. Supranormal multimers may contribute to the pathogenesis of systemic sclerosis by inducing platelet aggregation and enhancing adhesion to subendothelium under the conditions of elevated shear stress occurring in the partially occluded vessels of the arterial microcirculation of scleroderma.

Adult↗
PubMed1989

[Allergic contact dermatitis and oculorhinitis due to tulips].

A case of occupational allergic contact dermatitis with conjunctivitis and rhinitis due to tulips bulbs is described. The patient, aged 23, was employed in a florist storehouse. The dermatitis, affecting his hands, face, armpits, knees, elbows and ears, was accompanied by a rhinoconjunctivitis. Patch tests made with a tulip thin slice outcome positive results. The appearance, the way of arising and the results of the patch tests suggest the existence of an immediate type immunologic reaction (type I or IgE-dependent hypersensibility).

Adult↗
PubMed1989

[Von Willebrand factor multimers in systemic scleroderma].

In scleroderma endothelial cell damage plays an early and pivotal role in the pathogenesis of sclerotic lesions. In our study we determined whether or not plasma from 11 consecutive patients with scleroderma contained a subset of larger than normal (supranormal) multimers of von Willebrand factor which are potent inducers of platelet aggregation and adhesion. Supranormal multimers were found in all patients, but in none of the normal controls. Supranormal multimers may contribute to the pathogenesis of systemic sclerosis by inducing platelet aggregation and enhancing adhesion to subendothelium.

Adult↗