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L Andreassi

Publications and source records attributed to L Andreassi.

At least 55 records · Page 3Linked to original sources
PubMed1995

Mid-dermal elastolysis: an ultrastructural and biochemical study.

Mid-dermal elastolysis (MDE) is a particular elastic tissue disorder in which selective loss of elastic fibres occurs in the mid-dermis. It is clinically characterized by the appearance of fine wrinkling of the epidermis and perifollicular protrusion which gives the skin an aged appearance. It is sometimes associated with an inflammatory event such as urticaria while other cases are regarded as idiopathic. The pathogenesis of MDE is still obscure. Some authors have underlined the role of macrophage activation and others have imputed UV radiation. We report here a typical case of MDE arising after several attacks of solar urticaria. Electron microscopic and biochemical studies were carried out. Ultrastructural examination showed active elastophagocytosis by macrophages and mast cells, often degranulated, near phagocytosing cells. Biochemical studies demonstrated that fibroblasts derived from lesional skin of the MDE patient produced high levels of elastase and cathepsin G compared with fibroblasts from a healthy sex- and age-matched control. Phagocytosis of morphologically normal elastic tissue is a noticeable characteristic feature of MDE. In our case mast-cell activation and the abnormal synthesis and/or release of fibroblast elastolytic enzymes seemed to play a role in the pathogenesis of the MDE.

Adult↗
PubMed1993

Vulvar squamous papillomatosis and human papillomavirus infection. A polymerase chain reaction study.

Squamous papillae of the vulvar vestibule and introitus are quite a common clinical finding, however their origin is uncertain. They were formerly described as a normal variant of the mucosal epithelium, but recently they have been attributed to human papillomavirus (HPV) infection. Eight women with clinical findings compatible with a diagnosis of vulvar squamous papillomatosis were studied. All were free of other clinically evident HPV-related diseases. Vulvar scrapes and biopsy specimens were collected and used for DNA extraction and microscopic examination. DNA extracted from vulvar scrapings and from paraffin-embedded tissue was subjected to polymerase chain reaction (PCR). The reactions were performed with two sets of primers designed for the amplification of numerous HPV genotypes including those most commonly encountered in the genital area. Histological examination failed to reveal clear-cut signs of HPV infection in any subject. The PCR on the DNA extracted from vulvar scrapings revealed HPV infection in two cases. PCR performed on the DNA extracted from the paraffin-embedded tissue failed to detect HPV-DNA in any case. A 6-month follow-up showed no changes in the lesions. These results along with literature data, which is clearly inconsistent, indicated that the presence of HPV is coincident to, rather than causal of, vulvar squamous papillomatosis lesions. Patients with symmetrically distributed, long-standing vulvar papillae should, therefore, be carefully evaluated before starting therapy.

Adult↗
PubMed1993

Detection and typing of genital papillomaviruses in men with a single polymerase chain reaction and type-specific DNA probes.

BACKGROUND: Human papillomavirus (HPV) infection of the genitalia can produce both visible and subclinical lesions. Because different genotypes are preferentially associated with benign or malignant lesions, HPV detection and typing is clinically important. OBJECTIVE: Our purpose was to assess a polymerase chain reaction (PCR)-based, noninvasive procedure for HPV diagnosis and evaluate the reliability of the acetic acid test for revealing subclinical HPV lesions. METHODS: Mucosal samples were collected by gentle scraping, and PCR-positive samples were typed by hybridization with specific DNA probes. RESULTS: Seventy-eight men were assessed. The PCR procedure was reliable and easy to perform. No significant difference was found in the prevalence of HPV infection between patients whose results were acetowhite-positive and those whose results were acetowhite-negative. CONCLUSION: Detection of acetowhite epithelium, although useful for clinical examination, is not sufficiently specific and should not be used as a sole criterion for the diagnosis of HPV infection.

Acetates↗
PubMed1990

Measurement of cutaneous colour and assessment of skin type.

Skin colour was evaluated in summer in 91 Caucasian volunteers by means of a Minolta Chroma Meter CR-200, a colour analyser for measuring the reflective colour of surfaces by the tristimulus system. All the subjects were classified for skin type according to Fitzpatrick and minimal erythema dose determined. The skin colour of the buttock was taken to be the constitutive skin colour, and that of the cheek the facultative skin colour. It was found that the chromaticity of exposed skin was noticeably different from that of unexposed skin, being situated to the right of the latter in the chromaticity diagram. This means that skin that is usually exposed to the sun has a more intense red component, presumably because of increased vascularization. Exposed skin also showed lower reflectance (Y) or lightness (L*) than unexposed skin, probably because of pigmentation. Hence delta Y and delta L* give an approximate idea of the tanning capacity of each subject. delta Y and delta L* of skin types II and III were greater than delta Y and delta L* of skin type IV. This means that, with chronic exposure to sunlight, even fair skin can achieve a reasonable pigmentation. It is concluded that constitutive skin colour is a more meaningful parameter than facultative skin colour in assessing skin type.

Adolescent↗
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↗