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Biomedical subjects

S Leoni

Publications and source records attributed to S Leoni.

At least 109 records · Page 6Linked to original sources
PubMed1975

Hormone responsiveness of plasma membrane-bound enzymes in normal and regenerating rat liver.

The hormonal responsiveness of plasma membrane-bound enzymes (Na-+-K-+)-ATPase and adenylate cyclase has been investigated in normal and regenerating rat liver. (Na-+-K-+)-ATPase basal activity is not affected by surgery and only slightly affected by partial hepatectomy; its response to epinephrine and cyclic AMP is decreased only 15 h after hepatectomy. Adenylate cyclase activity of plasma membranes from untreated animals is stimulated by parathyroid hormone and thyroxine; partial hepatectomy increased basal activity as well as the stimulation exerted by the aforementioned hormones, when glucagon and epinephrine sensitivity is essentially unaltered.

Adenosine Triphosphatases↗
PubMedDate not supplied

Epinephrine regulation of amino acid transport in rat hepatocytes isolated during development.

The effect of epinephrine on the amino acid transport mediated by system A was investigated by determining the uptake of 2-amino [1-14C]isobutyric acid (AIB) in rat hepatocytes, freshly isolated at different stages of pre- and postnatal development. The data obtained show that the hormone increased AIB uptake, enhancing the Vmax, while Km was unchanged. This effect was evident in cells from adult, 18- to 20-day-old fetus, and neonate rat. Actinomycin D or cycloheximide abolished the hormone dependent increase. Experiments carried out with alpha- and beta-antagonists showed that the effect of epinephrine was beta-mediated in fetal life and alpha-mediated in adult life. Membrane binding experiments showed a higher value for epinephrine and beta-agonist dihydroalprenolol in the fetus versus the adult. The calcium depletion obtained after cell incubation with EGTA or calcium ionophore A23187 reduced the hormonal stimulation in the adult, and was ineffective in the prenatal period. An involvement of cAMP was present in the epinephrine modulation of AIB transport, both in adult and in fetal life.

Amino Acids↗
PubMedDate not supplied

[Autoimmune polyendocrinopathy and chronic mucocutaneous candidiasis].

A chronic mucocutaneous infection due to yeasts to the Candida genus can be part of the autoimmune polyglandular syndrome, described as APECS, APECED, SPA type I, CES. The authors describe the case of a young patient affected by mucocutaneous candidiasis, hypoparathyroidism and adrenal insufficiency. Chronic mucocutaneous candidiasis was diagnosed first in early childhood and was followed by the development of hypoparathyroidism (4 yrs) and adrenal insufficiency (5 yrs). The initial lesion of this syndrome is still unknown as the reason of the marked susceptibility to mucocutaneous candidiasis without systemic candidiasis. The treatment of mucocutaneous candidiasis has been improved by the introduction of orally active antifungal drugs as Ketoconazole, first, and fluconazole now.

Addison Disease↗
PubMedDate not supplied

Management of small hepatocellular carcinoma.

In the last years the incidence of hepatocellular carcinoma (HCC) is rising in cirrhotic patients worldwide. Due the importance of early and definite diagnosis of HCC, any nodular lesion detected in patients with chronic liver disease should be considered as suspicious for HCC. The screening and surveillance programs in patients with liver diseases have increased the number of small HCC detected at an early stage, when the therapeutic options available are able to provide benefit. The introduction of new imaging techniques has improved the accuracy of characterizing these nodules. According to the EASL recommendations, contrast-enhanced computed tomography (CT), contrast enhanced ultrasound (US) and magnetic resonance (MR) with different MR-contrast agents are currently used to characterize liver lesions. Imaging guided biopsy is recommended for small nodules or in lesions without typical features (arterial hypervascularization) in at least two imaging techniques. Frequently the differential diagnosis of small nodules is complicated by discordant vascularity and recent studies have also demonstrated the presence of small hypovascular HCC at perfusional US and helical CT. At present, different treatment options can be offered to patients with diagnosis of small HCC at an early stage; percutaneous techniques, surgical resection and liver transplantation can provide benefit in properly selected patients. This review describes some critical points regarding the detection, diagnosis and therapeutic management of small nodules of HCC in cirrhotic patients.

Biomarkers, Tumor↗
PubMedDate not supplied

[Skin disease in Basedow's disease].

Two cases of Graves' (Basedow) dermopathy are reported. In one case pretibial myxoedema was localized on the external surface of the legs down to insteps. In the second case a diffuse form involved both legs and was characterized by wrinkles and peau d'orange appearance at the ankles. In both cases a biopsy confirmed the diagnosis of Graves' dermopathy, showing diffuse areas of amorphus substance infiltrating the derma and fragmentation of collagen fibers. According to the literature, the skin lesions were associated with ophtalmopathy. Thyrostatic therapy affected ophtalmopathy in one of the patients, while pretibial myxoedema regressed in both. The pathogenesis of pretibial myxoedema is not completely clear yet, although dermopathy, along with ophtalmopathy and acropachy, is considered to be an extrathyroidal manifestation of Graves' disease related to bioassayble antibodies anti-TSH receptor. A class of dermopathy-associated antibodies (DAAb) has been identified. It seems to be a reliable biological marker for pretibial myxoedema since it is nearly absent in patients with ophtalmopathy and without dermopathy. Since DAAb does not stimulate human fibroblasts in culture, the role of DAAb in the development of Graves' dermopathy is still to be found.

Adult↗