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Biomedical subjects

L Andreassi

Publications and source records attributed to L Andreassi.

At least 55 records · Page 3Linked to original sources
PubMed1997

Extracorporeal photochemotherapy restores Th1/Th2 imbalance in patients with early stage cutaneous T-cell lymphoma.

Extracorporeal photochemotherapy (ECP) has been shown to be a potent activator of peripheral blood macrophages because it causes a marked release of macrophage-dependent proinflammatory cytokines, and it is therefore currently considered to be a safe and non-toxic immunomodulatory treatment. On this basis we studied the function of peripheral blood mononuclear cells (PBMC) in eight patients with early stage (Ib) cutaneous T-cell lymphoma (CTCL), before and 1 year after ECP, together with their clinical and histological responses. In particular we evaluated in vitro phytohaemagglutinin (PHA)-stimulated proliferation and production of interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) as well as lipopolysaccharide (LPS)-induced production of IL-12. Before treatment we observed that PBMC of patients produced significantly higher levels of IL-4 and lower levels of IFN-gamma and IL-12 than those of healthy control subjects. After 1 year of ECP, IL-4, IFN-gamma and IL-12 production no longer differed from that of control subjects. Moreover, we observed a good clinical result matched by histological response. Our data confirm that early-stage CTCL patients show a predominantly type-2 immune response that might be responsible for several immunological abnormalities found in this disease. We have demonstrated that ECP reverses the T-helper type 1/T-helper type 2 (Th1/Th2) imbalance and may therefore be considered an efficient biological response modifier.

Aged↗
PubMed1997

Relationship between skin color and sun exposure history: a statistical classification approach.

In this study our aim was to determine the biophysical values of constitutive skin color in Caucasians and to define the correlation between skin color and phototype assessed according to the Fitzpatrick method. Constitutive skin color was measured on the buttock, with a Minolta CR-200 colorimeter, in a population-of 557 consecutive subjects belonging to phototype categories I, II, III and IV. The colorimeter expresses the results in five different color systems. We used the "Yxy" and L*a*b* systems, which are the most widespread in dermatology. Statistical analysis of the data showed that the "Yxy" system is even more discriminant than the L*a*b* system when the Fitzpatrick classification scheme is adopted as the reference and shows a poor ability to correctly classify the intermediate phototypes (II and III). On the contrary the "Yxy" system performs well in distinguishing phototypes I and IV. To establish whether this low discriminating capacity for phototypes II and III is related to a low discriminating capacity of the method suggested by Fitzpatrick or by our procedure, an objective technique (minimal erythemal dose) should be used to evaluate the percentage errors of classification of both the Fitzpatrick method and instrumental measurement of skin color. The results of such a study are extremely important because the evaluation of skin color is objective, simple and has potential applications in dermatology and cosmetology.

Adult↗
PubMed1997

Extracorporeal photochemotherapy induces a significant increase in CD36+ circulating monocytes in patients with mycosis fungoides.

BACKGROUND: In patients with Sezary syndrome undergoing extracorporeal photochemotherapy it is currently thought that photodamage of a congruent number of pathogenic circulating T cells is a necessary condition for a specific anticlonal response to be induced against these cells by the immune system. However other mechanisms of action, such as the induction of release by photoirradiated monocytes of some cytokines, are thought to cooperate in the induction of a therapeutic response. OBJECTIVE: We investigated the effects of extracorporeal photochemotherapy on peripheral blood mononuclear cells in seven stage Ib cutaneous T cell lymphoma patients. METHOD: Samples of peripheral blood were taken before starting extracorporeal photochemotherapy (baseline), and before the 3rd and 6th cycle of treatment, and then incubated with specific monoclonal antibodies. RESULTS: The results showed a significant increase of CD8+ and CD36+ and a significant decrease of CD25+ in all the treated patients. CONCLUSION: Our results show that extracorporeal photochemotherapy is able to induce an increase of CD36+ cell in peripheral blood of patients with mycosis fungoides in its early stages. This subset of monocytes could be involved in the complex mechanism of action of extracorporeal photochemotherapy.

Aged↗
PubMed1997

The behaviour of Sarcoptes scabiei var. hominis in human skin: an ultrastructural study.

The biology of Sarcoptes scabiei var. hominis is poorly understood because of the lack of an in vivo or in vitro propagation system. To obtain more information on the mite behaviour in its natural habitat we conducted an ultrastructural study of burrows in a number of patients with common scabies. Scanning electron microscopy furnished attractive images of the tunnel, parasite body and eggs architecture and demonstrated the presence of holes in the tunnel roof probably representing aeration structures. Transmission electron microscopy showed a marked keratinocyte damage around burrowing mites, well evident ahead of the mite capitulum also. Faecal pellets containing keratinocyte micro-organelles (melanosomes and mitochondria) were documented in posterior midgut. For the first time we disclosed the adhesion mechanism of eggs to the burrow floor. We showed that the typical finger-like projections of the outer layer of the egg shell gradually disappear where the eggs are in contact with the tunnel floor. This allows the inner layer of the egg shell to fuse and stick with the damaged keratinocytes lining the tunnel floor. Our observation substantiates that Sarcoptes scabiei produces a proteolytic substance (salivary secretions?) that has a key role in its life cycle allowing burrowing, feeding and eggs-burrow adhesion.

Adolescent↗
PubMed1996

A case of cryofibrinogenaemia responsive to stanozolol.

Cryofibrinogen is a plasma protein complex whose presence in the peripheral blood is generally asymptomatic, but may sometimes cause multiple thromboembolism in the skin, lung and myocardium. The pathological manifestations associated with cryofibrinogenaemia have been treated with plasmapheresis and fibrinolytic drugs such as streptokinase, streptodornase and/or urokinase. Good results have recently been reported with stanozolol. This prompted us to treat a patient suffering from cryofibrinogenaemia with this androgenic hormone. The patient was a 66-year-old woman with rapidly evolving leg ulcers. Stanozolol was orally administered at 4 mg b.i.d. for 5 months and then gradually reduced. Plasma cryofibrinogen disappeared after 45 d from the start of therapy and cutaneous ulcers healed in 5 months.

Aged↗
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↗