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G Tadini

Publications and source records attributed to G Tadini.

16 recordsLinked to original sources
PubMed1992

A mathematical model for the computation of the forces exerted by the facial orthopedic mask.

This study presents a model for the computation of the forces exerted on the chin and on the forehead by the facial orthopedic mask in skeletal Class III malocclusions. Cephalometric data as well as geometry of the mask are taken into account to simulate in quantitative terms the entire approach. A computer program has been implemented to validate the model on a group of patients. Despite the approximations about the mechanical characteristics of the appliance and of the constraints (rigid body, ideal constraints) and despite the unavoidable errors in the estimation of the geometric parameters (dimensions and angles), it is shown that the computation of the forces (in orientation and in magnitude) at the forehead and at the chin is possible. Some practical applications of the model are presented.

Adolescent↗
PubMed1989

Circadian rhythm of natural killer cell activity in vitiligo.

Ten patients with vitiligo, either in the active (six cases) or static (four cases) phase, and twelve healthy control subjects were studied with a standard cytotoxicity assay to evaluate the circadian rhythm of natural killer cell activity from peripheral blood mononuclear cells. The natural killer cell activity was measured at the zero, sixth, twelfth, and eighteenth hours of the day. The results demonstrated that patients with vitiligo had significantly higher natural killer cell activity compared with normal controls. When patients with static and active vitiligo were compared, those with the static form had increased natural killer cell activity at all times except noon, whereas those with active form had increased natural killer cell activity only at 0600 and 1800. These changes shifted the acrophase of the circadian rhythm of each group. Indeed, by cosinor analysis, both patients with vitiligo and normal controls had similar circadian rhythms, but the acrophase was shifted from 0602 in control subjects to 0435 in the ten patients with vitiligo. The acrophase in the six patients with active vitiligo was found to be closest to that of normal controls (0508). These findings indicate that natural killer cell activity abnormalities are more marked in the static rather than in the active form of vitiligo.

Adult↗
PubMed1989

P53 and oncogenes expression in psoriasis.

Activity of p53, H-ras, c-myc and c-fos in psoriatic lesions was studied using monoclonal antibodies (MoAbs) performing a sensitive immunohistochemical method on frozen sections. Normal skin from surgery was used as control. Reactivity of p53, H-ras and c-myc is remarkable in psoriatic plaques but, in contrast, c-fos expression does not show differences compared to control skin. These findings led us to speculate about the importance of cellular oncogenes in the pathogenesis of psoriasis.

Antibodies, Monoclonal↗
PubMed1988

Plasma melatonin levels in psoriasis.

Melatonin is synthesized and secreted by the pineal gland. A daily rhythm of melatonin secretion, with high plasma values during the dark period, has been found in all vertebrates studied so far. In psoriatics, several hormones, including GH and prolactin, have altered chronobiology, and some studies in humans suggest that melatonin affects the levels of GH and prolactin. We investigated circadian melatonin rhythm in 13 male psoriatics and 13 healthy males with an RIA specific for measuring the hormone in plasma. Samples were taken at 6 a.m., 8 a.m., 12.00, 4 p.m., 8 p.m. and 2 a.m. Differences in (mean +/- SD) plasma melatonin levels were analysed by Student's t-test. Our results show that psoriatic patients had lost the nocturnal peak and usual circadian rhythm of melatonin secretion. Levels of melatonin were significantly lower than in controls at 2 a.m., and higher at 6 and 8 a.m. and at 12 noon. Further investigations of this disorder of melatonin secretion in psoriasis are needed to understand its significance.

Adult↗
PubMed1985

Circadian rhythm of the in vivo migration of neutrophils in psoriatic patients.

Neutrophil chemotaxis in ten subjects with psoriasis was evaluated in vivo by the quantitative skin-window technique using autologous serum and in vitro using a modified Boyden technique. The in vitro chemotaxis values of the psoriatics were significantly lower (P less than 0.01) than those of healthy controls. When measured in vivo, however, we found that, after 9, 12, and 24 h, the values of the migrating polymorphonuclear leukocytes (PMNL) of psoriasis patients were only slightly and non-significantly lower than normal values. Analysing the in vivo chemotaxis data by a chronobiological method, we demonstrated statistically significant circadian rhythms in nine of the ten psoriasis patients. In seven of the patients, we found that the population had a significant rhythm, with the acrophase at -328 degrees. Our in vitro and in vivo values are in agreement with previously published values. However, there was a definite circadian rhythm of migration that we could not demonstrate in normal controls. We consider that our data reveal a significant and important difference between neutrophil chemotaxis in vivo in normal subjects and that in patients with psoriasis.

Adult↗
PubMedDate not supplied

[Infantile gluteal granuloma. Case report].

A 5 months old infant having "granuloma gluteale infantum" (G.G.I.) is reported. One or more tumorous red-purple nodules on gluteal or on genitocrural area are the usual cutaneus injuries of G.G.I. The histologic aspect resembles pyogenic granulomas. The exact pathogenesis of G.G.I. is still to be defined; nevertheless the use of plastic diaper covers and topical fluorinated steroid preparations seems to have great influence.

Biopsy↗