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Biomedical subjects

P Santoianni

Publications and source records attributed to P Santoianni.

At least 19 recordsLinked to original sources
PubMed2003

In vitro effects of ultraviolet A on histamine release from human basophils.

BACKGROUND: As long-wave ultraviolet (UV) radiation penetrates the dermis, connective tissue cellular components and circulating blood cells can be possible targets for solar UVA. Basophils, involved in the effector phase of the inflammatory response, play a part in skin diseases such as chronic urticaria, psoriasis, atopic dermatitis, fixed drug eruption, allergic contact dermatitis, urticaria pigmentosa, systemic sclerosis and bullous pemphigoid. OBJECTIVE: The evaluation of the in vitro effect of UVA on histamine release from human basophils. METHODS: Basophils from healthy human volunteers were irradiated, respectively, with UVA at doses of 2.5, 5, 7.5, 10, 20 and 50 J/cm2 and then incubated with an anti-IgE serum. A fluorimetric technique was employed to determine histamine release from samples: (i) incubated with 2% HClO4 (complete lysis of basophils); (ii) irradiated with increasing doses of UVA; and (iii) unirradiated (controls). RESULTS: Histamine release was: 100% for HClO4 incubated basophils, 30% for unirradiated and anti-IgE incubated cells (controls) and 27%, 24%, 34%, 41%, 60% and 70% for basophils irradiated with UVA doses, respectively, of 2.5, 5, 7.5, 10, 20 and 50 J/cm2 and incubated with anti-IgE. Histamine releasability from irradiated samples was statistically significant (P < 0.05), in comparison with controls, at UVA doses equal to 5, 10, 20 and 50 J/cm2. CONCLUSIONS: UVA exerts, at least in vitro, a biphasic dose-dependent action on histamine release from human basophils incubated with an anti-IgE serum: at the lowest irradiation doses (< 5 J/cm2) it exerts an inhibitory effect and at the highest doses (> or = 10 J/cm2) histamine release increases significantly.

Basophils↗
PubMed1998

Phaeomelanin versus eumelanin as a chemical indicator of ultraviolet sensitivity in fair-skinned subjects at high risk for melanoma: a pilot study.

It is now generally agreed that solar exposure is a major external factor in the causation of cutaneous melanoma in light skinned populations with red hair and a marked susceptibility to the acute effects of ultraviolet (UV) radiation. In the present study, we investigated the existence of a possible relationship between hair melanin composition and minimal erythema dose (MED), as an indicator of UV sensitivity, in a group of 15 healthy red-haired subjects aged 20-46 years. In spite of comparable skin and hair colour, marked variations were observed in the MED values as well as in the hair melanin composition. Phaeomelanin levels varied in the range 0.026-0.53% w/w and were generally comparable to or higher than eumelanin levels (0.042-0.17% w/w). No significant relationship was found between MED values and phaeomelanin, eumelanin or total melanin (eumelanin plus phaeomelanin) content. Notably, however, a gross positive correlation was found between the eumelanin/phaeomelanin ratio and the MED values. These results would suggest that a high UV sensitivity is associated with high phaeomelanin and low eumelanin levels, and point to the eumelanin/phaeomelanin ratio as a novel chemical parameter that could be used for predicting individuals at high risk for skin cancer and melanoma.

Adult↗
PubMed1994

Dose-dependent visible effect on mice Langerhans cell membrane markers.

Ultraviolet B and psoralen plus UVA treatment induce antigenic and enzymatic changes in Langerhans cells (LC). The aim of this study was to investigate the visible (VIS) effect on mice LC surface markers. As visible source, a slide projector equipped with a 150-W tungsten lamp, emitting between 400 and 740 nm (maximum at 580 nm) was used. Mice (BALB/c and C3H) were divided into groups, each irradiated with visible single fixed doses (ranging from 10 to 1000 J/cm2). The mice backs were shaved before irradiation. Skin biopsies obtained immediately after irradiation were processed for immunofluorescence and electron microscopy. Immunofluorescent studies showed: 1) a complete depletion of LC membrane markers at a dose of 700 J/cm2; 2) no effect at visible doses ranging between 0 and 75 J/cm2; 3) a dose-dependent effect with doses between 100 and 700 J/cm2. Electron microscopy revealed no cellular damage of LC at the visible doses administered.

Animals↗
PubMed1992

Peptide T in the treatment of severe psoriasis.

We investigated the effect of treatment with peptide T on severe psoriasis in 5 patients. Within 2 months, peptide T led to complete remission of all lesions in 1 patient and to good improvement in 3 others. In 1 patient, no effect was observed.

Adult↗
PubMed1988

Effect of nicotinic acid administration on serum levels of bilirubin and iron in patients with porphyria cutanea tarda.

Nicotinic acid (NA) administration in Gilbert's syndrome (GS) patients promotes an increment of bilirubin and of total iron serum levels, dependent on a defective hepatic bilitranslocase function and on a haemolytic effect of NA. In porphyria cutanea tarda (PCT): (1) the effect of nicotinic acid on bilirubinaemia is superimposable to that in controls; (2) a well documented disturbance of iron metabolism occurs; (3) but relationship between bilirubin and iron under NA load has never been investigated. The administration of 5.9 mumol/kg body weight of NA to 12 PCT patients, 10 GS subjects and nine healthy volunteers of comparable age resulted in: (1) normal behaviour of bilirubin parameters in PCT but higher bilirubinaemic values in GS subjects; (2) normal values of serum iron in GS subjects, but higher baseline values and lower sideraemic effect of nicotinic acid in PCT patients; (3) a normal NA half-life in PCT and enhanced in GS subjects. These findings confirm a defective bilirubin uptake and excretion by the liver of GS subjects with a normal iron metabolism. On the contrary, in our PCT patients a normal clearance of bilirubin occurs, but a complex disturbance of iron metabolism is well evident in baseline conditions as well as after NA administration. The latter being probably the consequence of an enhanced excretion of iron extraproduced by the haemolytic effect of NA.

Adult↗
PubMed1986

Tyrosinemia type II in two cases previously reported as Richner-Hanhart syndrome.

Two sibs with palmo-plantar keratosis and dendritic corneal opacities, previously described as suffering from Richner-Hanhart syndrome by other authors, about 25 years ago, showed increased plasma and urine tyrosine levels. Their neurological and mental features were within normal limits. A comprehensive review of the literature showed a total of 47 cases of fully documented tyrosinemia type II; 8 more patients also had the clinical features of the disease, but aminoacidemia had never been observed. The importance of early diagnosis is stressed, since a low tyrosine-phenylalanine diet dramatically improves the symptoms and may prevent mental retardation.

Adult↗
PubMed1984

Inadequate effect of helium-neon laser on venous leg ulcers.

A study to determine whether laser radiation of low-power photon density would really affect the healing of venous leg ulcers in man was performed. The ulcers were irradiated 6 d per wk with a helium-neon laser (wavelength 632.8 nm). Energy densities of 1 J/cm2 (16 patients) and 4 J/cm2 (17 patients) were administered daily. The control group (28 patients) received only antiseptic local compresses as treatment. No statistically significant difference between the laser-treated group and the control group was found. It was concluded that helium-neon laser radiation has no advantages over standard local treatments, at least with the dosage schedules and protocols employed.

Adult↗