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Biomedical subjects

L Andreassi

Publications and source records attributed to L Andreassi.

At least 73 records · Page 4Linked to original sources
PubMed1989

Ultrastructural study of pseudo-Kaposi's sarcoma (Bluefarb-Stewart type).

An ultrastructural study of the skin lesion of a young patient affected by pseudo-Kaposi's sarcoma of the Bluefarb-Stewart type (BSS) is reported. The neoplasm consisted of a proliferation of vascular structures mostly consisting of a solid bud of endothelial cells surrounded by a thinned and polystratified basement membrane and several pericytes. Both endothelial cells and pericytes were of normal ultrastructural appearance. Intervascular "stromal" cells were few and morphologically identified as macrophages and/or phagocytic fibroblasts. Masses of hemosiderin were detected outside the cells and in the macrophages, endothelial cells, and pericytes. Intracytoplasmatic crystalloid inclusions similar to those found in fetal endothelium and hemangiomas were observed in a few endothelial cells. These findings are different from those of previously reported cases of pseudo-Kaposi's sarcoma and may be helpful in distinguishing Kaposi's sarcoma from BSS. The role of immunodeficiency in the onset of BSS is discussed.

Adult↗
PubMed1988

[Not Available].

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History, Early Modern 1451-1600↗
PubMed1988

Inhibitory effects of psoralens on rat liver cyclic AMP phosphodiesterase.

TMP (4,5',8-trimethylpsoralen) usually employed in PUVA therapy and TMA (4,6,4'-trimethylangelicin), phototherapeutic agent under clinical and biological investigation, show an inhibitory effect of competitive type on the low Km cyclic AMP phosphodiesterase present in rat liver. The two drugs exhibit Ki values of 135 and 320 microM, respectively.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1988

Khellin, a naturally occurring furochromone, used for the photochemotherapy of skin diseases: mechanism of action.

Khellin, a naturally occurring furochromone, used in the past as a coronary vasodilator, has recently been used in the photochemotherapeutic treatment of vitiligo and psoriasis. With the aim of elucidating its mechanism of action, the interactions both in ground and excited states between the drug and DNA were studied in vitro. Khellin forms in the dark a molecular complex with DNA. By subsequent irradiation (365 nm) the drug photoconjugates covalently with the macromolecule, although the rate of photobinding is rather low. The in vivo photobinding of khellin to the DNA of Ehrlich ascites tumor cells is also low. In photoaddition with the macromolecule the drug forms inter-strand cross-links, although again in small amounts. The furan side monoadduct between khellin and thymine, formed in the photoreaction between the drug and DNA, was isolated and characterized, and shows a cis-syn configuration.

Animals↗
PubMed1987

Phenotypic characters related to skin type and minimal erythemal dose.

Minimal erythemal dose (MED) was determined in 155 healthy Caucasoid subjects. Hair color, eye color, number of freckles, and history of sun reactivity and tanning ability, according to the system proposed by Fitzpatrick, were also recorded. In the subjects with skin type I, the values of MED were relatively homogeneous, whereas in subjects with skin types II, III and IV there was a wide variation of MED values. In spite of this variation, a good correlation was found between MED and skin types. MED was found to correlate with hair color, eye color and number of freckles only for some variants of these characters. Low values of MED correlated significantly with red hair, blue eyes and highly freckled skin. Between other variants of the same characters, MED values did not differ significantly. This means that phenotypic characters suggest low MED values only in individuals with red hair, blue eyes and many freckles. In these subjects the phenotypic characters studied may be considered indicative of cancer risk. For all other Caucasoid people the phenotypic characters studied are not predictive of MED nor, probably, of cancer risk.

Adolescent↗
PubMed1986

Ultrastructural observations in lichen nitidus.

Lichen nitidus (LN) and lichen planus (LP) are considered by some investigators to be two variants of the same disease, and by others to be two distinct dermatoses. In order to obtain further information about the relationship between LN and LP we examined the ultrastructure of lesions from two LN patients. In the central part of the lesion, the basement membrane was absent, or was interrupted by migrating phagocytes or lymphocytes. The basal cells and the lower cells of the stratum spinosum exhibited karyolysis and appeared to be compressed and often necrotic. In the upper dermis irregular cell debris full of clumps of tonofilaments and colloid-body-like structures was observed. A dense dermal infiltrate of macrophages, lymphocytes, fibrocytes, and Sezary-like cells was present. Signs of cooperation between lymphocytes and macrophages were also evident. The periphery of the lesion showed no pathological features except for enlargement of the intercellular spaces and the presence of mononuclear cells scattered through the epidermis. Several normal Langerhans cells were noticed. These ultrastructural findings were quite similar to those reported for LP.

Adult↗
PubMed1984

[Therapy with bromocriptine and behavior of various hormones in psoriasis patients].

The activity of bromocriptin has been clinically tested on 18 patients suffering from psoriasis. The plasma levels of Human Growth Hormone (HGH), Human Adrenocorticotropic Hormone (ACTH), Thyroid Stimulating Hormone (TSH), Prolactin (PL), Aldosterone and Cortisol were investigated in these 18 patients along with 35 untreated psoriatic patients and 19 normal subjects. Bromocriptin was shown to be effective in 13 of our 18 psoriatic patients. Plasma levels of HGH, ACTH, and Aldosterone, measured in all 53 psoriatic patients, were found to be higher than normal in 11, 26 and 40 patients respectively (HGH and Aldosterone: p less than 0,005; ACTH: p less than 0,001).

Adrenocorticotropic Hormone↗
PubMed1984

[Use of monoclonal antibody 225.28S in the study of nevus cells in culture].

The aim of this work is to identify and purify cultured nevus cells. We used for our study monoclonal antibody 225.28S. This antibody reacts with a surface antigen which is expressed by nevus cells and melanoma cells, but it does not react with normal melanocytes. We studied 10 dermic nevi and we observed that antigenic determinant survives in cultured nevus cells. These results allowed us to employ the method of panning for purify cultured nevus cells.

Antibodies, Monoclonal↗
PubMed1984

Immune response in thermally injured guinea-pigs treated with methisoprinol.

A series of experiments has been performed in order to evaluate the effects of methisoprinol on immune response following thermal injury. Methisoprinol treatment induced a sharp stimulation of the cell-mediated immune response in burned animals. This finding demonstrates that methisoprinol may be useful in burns to prevent infections related to immune depression.

Animals↗
PubMed1982

Pemphigus antibodies fixation and keratinocyte differentiation in organ cultures. Effects of some agents influencing the intracellular content of cyclic AMP.

The effect of some agents, influencing the cyclic adenosine 3', 5'-monophosphate (cAMP) content of human cells, on the ability of the keratinocytes of binding pemphigus antibodies was studied by using tissue cultures of rabbit esophagus. As demonstrated by immunofluorescence (IF) for IgG, the bound antibodies appeared markedly decreased on esophagus explants grown under standard conditions, that is without test agents, when compared to ones fixed on fresh esophagus. But the IF reaction was remarkably more intense when methylxanthines or epinephrine were added to the growth medium of the cultures. Following the addition of these agents to the cultures some histologic modifications appeared in the explants, indicating that the keratinization process had probably been stimulated. This temporal relationship of immunofluorescence and histologic findings seems to suggest the hypothesis that keratinocyte differentiation, regulation of cAMP intracellular content, and pemphigus antibodies fixation are related processes.

1-Methyl-3-isobutylxanthine↗
PubMed1978

DNA-repair after UV-irradiation in skin fibroblasts from patients with actinic keratosis.

Autoradiographic counting technique was utilized to measure the ultraviolet-induced unscheduled DNA synthesis of skin fibroblasts from 12 patients with chronic actinic keratosis and from 12 healthy donors of about the same age. In order to reveal a possible regional difference of DNA repair between the parts of the body ordinarily exposed and those parts unexposed to sunlight, two cell strains were used for each examined subject; one developed from the forehead skin and the other from the abdominal or axillary skin. Unscheduled DNA synthesis appeared depressed in actinic keratosis patients, as compared with controls. In all examined subjects however cell strains from exposed skin showed a DNA repair more active than cell strains from unexposed skin. These findings show that skin cancer may be promoted in actinic keratosis patients by a defect of DNA repair. The exalted DNA repair of chronically sun exposed skin is probably the consequence of a defensive process caused by enzymatic induction.

Aged↗