PubMed Health⌕ Search

Biomedical subjects

A Amantea

Publications and source records attributed to A Amantea.

At least 19 recordsLinked to original sources
PubMed1992

Penile lentiginosis. An ultrastructural study.

This study on five patients has revealed more extensive alterations to melanocytes than previously reported, and emphasizes the fact that depigmentation is an essential element of the condition. In hyperpigmented areas, melanocytes were increased in number along the basal layer of the epithelium, were hyperactive, and in some cases contained bizarre melanosomes. In two cases there was suggestion of a defect in melanosome transfer to keratinocytes. Lymphocytes were closely apposed to melanocytes, and, in hypopigmented areas, were clearly involved in their disintegration. In depigmented areas, there was complete absence of melanocytes and of melanosomes in keratinocytes, and lymphocytes were present in the basal layer. In general, the appearances did not resemble melanoma in situ with spontaneous regression, although a second biopsy of one patient after one year did reveal features of melanocytes suggestive of an early stage of this condition. The study has provided no clear information as to the initial cause of the condition, but the manner of destruction of melanocytes suggests an immune reaction. Neither has it been of assistance in suggesting a more precise name for it.

Adult↗
PubMed1991

Distribution of anti-keratins and anti-thymostimulin antibodies in normal and in Down's syndrome human thymuses.

The localization of three monoclonal (A,B,C) anti-cytokeratin antibodies and of an anti-thymostimulin antibody were studied in normal children's thymuses, aged from 2 months to 10 1/2 years and in Down's children thymuses, aged from 5 months to 6 1/2 years. Two anti-cytokeratins were positive in the thymus: the anti-B was found in the epithelial cells of all thymic zones, the anti-C only in the external cells of Hassall's corpuscles. The distribution and the intensity of immuno-reactions were the same in normal and in Down's thymuses. The distribution of anti-thymostimulin was superimposed to the distribution of anti-cytokeratin B and was similar in normal and in the youngest Down's thymuses, whereas in the 6 1/2 years-old Down's thymuses there was a loss of anti-TS reaction in the subcapsular zone. A relationship between the reduction of anti-thymostimulin immuno-reaction and the beginning of an eventual loss of T-lymphocyte differentiation was supposed.

Antibodies↗
PubMed1991

Squalene peroxides may contribute to ultraviolet light-induced immunological effects.

Ultraviolet (UV) irradiation is capable of producing a dose-dependent decomposition of skin surface lipids and particularly of squalene, with the concomitant generation of active lipoperoxides. The biological effects of UV-peroxidated squalene were tested, compared with those produced by synthetic lipoperoxides (cumene hydroperoxide), on some immunological parameters in vivo modified by UVB irradiation. Application of UV-peroxidated squalene as well as cumene hydroperoxide significantly inhibited the induction of contact hypersensitivity to dinitrofluorobenzene in mice, which was associated with a decrease in the number of ATPase positive cells. The effect was dose-dependent (over 40 micrograms for peroxidated squalene and over 20 micrograms for cumene) and relevant after 2 d of treatment. Down-regulation towards the applied hapten was demonstrated. The results indicate that UV-induced lipoperoxides of squalene are capable of inhibiting the induction of contact hypersensitivity in mice and suggest that, among the other photoproducts generated in humans, squalene peroxides may play a role as biochemical messengers of the biological effects of UV irradiation of the skin.

Animals↗
PubMed1990

[Congenital smooth muscle hamartoma. Clinical-histological considerations (3 cases)].

The Authors report 3 cases of "Congenital Smooth Muscle Hamartoma" (CSMH). CSMH presents as congenital patches or slightly indurated plaques with prominent overlying hair, often hyperpigmented. Histopathologic examination showed increased numbers of well-defined smooth muscle bundles in the superficial and deep dermis. CSMH and Becker's nevus should be considered in the differential diagnosis of any congenital hairy hamartoma.

Adolescent↗
PubMed1990

[Perforating pilomatrixoma in adults].

Two rare cases of perforating pilomatrixoma similar to those reported in the literature are described. Clinical examination showed in two old-women a reddish inflammatory exophytic tumor, 1 cm in diameter, with central erosive surface, with a rapid growth (3-5 months). Histologic examination showed: multiple masses of basophilic cells situated in the upper dermis making contact with the epidermis in a "follicle-like" opening; occurrence of transepithelial elimination phenomena.

Aged↗
PubMed1989

Eccrine angiomatous hamartoma: a lipomatous variant.

The eccrine angiomatous hamartoma is a rare cutaneous lesion histologically characterized by the presence in the intradermal lobules of mature eccrine sweat glands and angiomatous capillary channels. We report a case of eccrine angiomatous hamartoma with unusual lipomatous involvement.

Adipose Tissue↗
PubMed1988

Multiple minute digitate hyperkeratosis.

We report a case of multiple minute digitate hyperkeratosis. The patient had hundreds of keratotic lesions--some tiny and spiked, others larger, flat papules--localized on the trunk and arms. Histologic sections showed focal areas of compact hyperorthokeratosis with few dermal changes. Ultrastructurally, keratohyalin granules were smaller than normal. The keratin pattern was one of a normal variant. Odland bodies present. Various family members of the patient, in different generations, were affected.

Female↗
PubMed1986

Porphyrins in Rotor's syndrome: a study on an Italian family.

Porphyrins in urine, plasma, erythrocytes and feces have been tested in two brothers affected by Rotor's syndrome and in three of their phenotypically normal relatives. In all five subjects normal values of delta-aminolevulinic acid and porphobilinogen in urine, and of prophyrins in plasma, erythrocytes and feces, were found. The two patients showed a marked increase in total urinary coproporphyrin excretion with a high percentage of isomer I. These observations confirm the hypothesis of a different route of the porphyrin excretion in Rotor's syndrome with a shift from the fecal route to the urinary one, and do not agree with the suggestion of an increased hepatic porphyrin production in this type of hyperbilirubinemia.

Adult↗
PubMed1984

Identification of thymostimulin secreting cells in calf thymus by immunoperoxidase method.

An anti- thymostimulin (TS) serum was tested on calf thymus to study the localization of the hormonal factor. The immunoperoxidase method was applied to tissue fixed in Bouin's fluid and embedded in paraffin, or to tissue fixed in paraformaldehyde and embedded in Epon for semi-thin sections. Immuno-reactivity was shown, with DAB- Fluka , in reticulo-epithelial cells in the medulla, and between the cortex and the medulla, while with DAB-Sigma reactivity was found in the cortex as well. The external cells of Hassall's corpuscles were also reactive. Myoid cells were not reactive. In semi-thin sections a weak reactivity was noted at the periphery of a few lymphocytes. Comparison with the localization of other thymic factors, and the possibility of a functional cycle of the epithelial cells synthesizing one or more factors are discussed.

Animals↗